1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2014, 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 Debug; use Debug;
32 with Einfo; use Einfo;
33 with Elists; use Elists;
34 with Errout; use Errout;
36 with Exp_Dist; use Exp_Dist;
37 with Exp_Util; use Exp_Util;
38 with Expander; use Expander;
39 with Freeze; use Freeze;
40 with Gnatvsn; use Gnatvsn;
41 with Itypes; use Itypes;
43 with Lib.Xref; use Lib.Xref;
44 with Nlists; use Nlists;
45 with Nmake; use Nmake;
47 with Restrict; use Restrict;
48 with Rident; use Rident;
49 with Rtsfind; use Rtsfind;
50 with Sdefault; use Sdefault;
52 with Sem_Aux; use Sem_Aux;
53 with Sem_Cat; use Sem_Cat;
54 with Sem_Ch6; use Sem_Ch6;
55 with Sem_Ch8; use Sem_Ch8;
56 with Sem_Ch10; use Sem_Ch10;
57 with Sem_Dim; use Sem_Dim;
58 with Sem_Dist; use Sem_Dist;
59 with Sem_Elab; use Sem_Elab;
60 with Sem_Elim; use Sem_Elim;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Res; use Sem_Res;
63 with Sem_Type; use Sem_Type;
64 with Sem_Util; use Sem_Util;
65 with Stand; use Stand;
66 with Sinfo; use Sinfo;
67 with Sinput; use Sinput;
68 with Stringt; use Stringt;
70 with Stylesw; use Stylesw;
71 with Targparm; use Targparm;
72 with Ttypes; use Ttypes;
73 with Tbuild; use Tbuild;
74 with Uintp; use Uintp;
75 with Uname; use Uname;
76 with Urealp; use Urealp;
78 package body Sem_Attr is
80 True_Value : constant Uint := Uint_1;
81 False_Value : constant Uint := Uint_0;
82 -- Synonyms to be used when these constants are used as Boolean values
84 Bad_Attribute : exception;
85 -- Exception raised if an error is detected during attribute processing,
86 -- used so that we can abandon the processing so we don't run into
87 -- trouble with cascaded errors.
89 -- The following array is the list of attributes defined in the Ada 83 RM
90 -- that are not included in Ada 95, but still get recognized in GNAT.
92 Attribute_83 : constant Attribute_Class_Array := Attribute_Class_Array'(
98 Attribute_Constrained |
105 Attribute_First_Bit |
111 Attribute_Leading_Part |
113 Attribute_Machine_Emax |
114 Attribute_Machine_Emin |
115 Attribute_Machine_Mantissa |
116 Attribute_Machine_Overflows |
117 Attribute_Machine_Radix |
118 Attribute_Machine_Rounds |
124 Attribute_Safe_Emax |
125 Attribute_Safe_Large |
126 Attribute_Safe_Small |
129 Attribute_Storage_Size |
131 Attribute_Terminated |
134 Attribute_Width => True,
137 -- The following array is the list of attributes defined in the Ada 2005
138 -- RM which are not defined in Ada 95. These are recognized in Ada 95 mode,
139 -- but in Ada 95 they are considered to be implementation defined.
141 Attribute_05 : constant Attribute_Class_Array := Attribute_Class_Array'(
142 Attribute_Machine_Rounding |
145 Attribute_Stream_Size |
146 Attribute_Wide_Wide_Width => True,
149 -- The following array contains all attributes that imply a modification
150 -- of their prefixes or result in an access value. Such prefixes can be
151 -- considered as lvalues.
153 Attribute_Name_Implies_Lvalue_Prefix : constant Attribute_Class_Array :=
154 Attribute_Class_Array'(
159 Attribute_Unchecked_Access |
160 Attribute_Unrestricted_Access => True,
163 -----------------------
164 -- Local_Subprograms --
165 -----------------------
167 procedure Eval_Attribute (N : Node_Id);
168 -- Performs compile time evaluation of attributes where possible, leaving
169 -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately
170 -- set, and replacing the node with a literal node if the value can be
171 -- computed at compile time. All static attribute references are folded,
172 -- as well as a number of cases of non-static attributes that can always
173 -- be computed at compile time (e.g. floating-point model attributes that
174 -- are applied to non-static subtypes). Of course in such cases, the
175 -- Is_Static_Expression flag will not be set on the resulting literal.
176 -- Note that the only required action of this procedure is to catch the
177 -- static expression cases as described in the RM. Folding of other cases
178 -- is done where convenient, but some additional non-static folding is in
179 -- Expand_N_Attribute_Reference in cases where this is more convenient.
181 function Is_Anonymous_Tagged_Base
185 -- For derived tagged types that constrain parent discriminants we build
186 -- an anonymous unconstrained base type. We need to recognize the relation
187 -- between the two when analyzing an access attribute for a constrained
188 -- component, before the full declaration for Typ has been analyzed, and
189 -- where therefore the prefix of the attribute does not match the enclosing
192 procedure Set_Boolean_Result (N : Node_Id; B : Boolean);
193 -- Rewrites node N with an occurrence of either Standard_False or
194 -- Standard_True, depending on the value of the parameter B. The
195 -- result is marked as a static expression.
197 -----------------------
198 -- Analyze_Attribute --
199 -----------------------
201 procedure Analyze_Attribute (N : Node_Id) is
202 Loc : constant Source_Ptr := Sloc (N);
203 Aname : constant Name_Id := Attribute_Name (N);
204 P : constant Node_Id := Prefix (N);
205 Exprs : constant List_Id := Expressions (N);
206 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
211 -- Type of prefix after analysis
213 P_Base_Type : Entity_Id;
214 -- Base type of prefix after analysis
216 -----------------------
217 -- Local Subprograms --
218 -----------------------
220 procedure Address_Checks;
221 -- Semantic checks for valid use of Address attribute. This was made
222 -- a separate routine with the idea of using it for unrestricted access
223 -- which seems like it should follow the same rules, but that turned
224 -- out to be impractical. So now this is only used for Address.
226 procedure Analyze_Access_Attribute;
227 -- Used for Access, Unchecked_Access, Unrestricted_Access attributes.
228 -- Internally, Id distinguishes which of the three cases is involved.
230 procedure Bad_Attribute_For_Predicate;
231 -- Output error message for use of a predicate (First, Last, Range) not
232 -- allowed with a type that has predicates. If the type is a generic
233 -- actual, then the message is a warning, and we generate code to raise
234 -- program error with an appropriate reason. No error message is given
235 -- for internally generated uses of the attributes. This legality rule
236 -- only applies to scalar types.
238 procedure Check_Ada_2012_Attribute;
239 -- Check that we are in Ada 2012 mode for an Ada 2012 attribute, and
240 -- issue appropriate messages if not (and return to caller even in
243 procedure Check_Array_Or_Scalar_Type;
244 -- Common procedure used by First, Last, Range attribute to check
245 -- that the prefix is a constrained array or scalar type, or a name
246 -- of an array object, and that an argument appears only if appropriate
247 -- (i.e. only in the array case).
249 procedure Check_Array_Type;
250 -- Common semantic checks for all array attributes. Checks that the
251 -- prefix is a constrained array type or the name of an array object.
252 -- The error message for non-arrays is specialized appropriately.
254 procedure Check_Asm_Attribute;
255 -- Common semantic checks for Asm_Input and Asm_Output attributes
257 procedure Check_Component;
258 -- Common processing for Bit_Position, First_Bit, Last_Bit, and
259 -- Position. Checks prefix is an appropriate selected component.
261 procedure Check_Decimal_Fixed_Point_Type;
262 -- Check that prefix of attribute N is a decimal fixed-point type
264 procedure Check_Dereference;
265 -- If the prefix of attribute is an object of an access type, then
266 -- introduce an explicit dereference, and adjust P_Type accordingly.
268 procedure Check_Discrete_Type;
269 -- Verify that prefix of attribute N is a discrete type
272 -- Check that no attribute arguments are present
274 procedure Check_Either_E0_Or_E1;
275 -- Check that there are zero or one attribute arguments present
278 -- Check that exactly one attribute argument is present
281 -- Check that two attribute arguments are present
283 procedure Check_Enum_Image;
284 -- If the prefix type is an enumeration type, set all its literals
285 -- as referenced, since the image function could possibly end up
286 -- referencing any of the literals indirectly. Same for Enum_Val.
287 -- Set the flag only if the reference is in the main code unit. Same
288 -- restriction when resolving 'Value; otherwise an improperly set
289 -- reference when analyzing an inlined body will lose a proper warning
290 -- on a useless with_clause.
292 procedure Check_First_Last_Valid;
293 -- Perform all checks for First_Valid and Last_Valid attributes
295 procedure Check_Fixed_Point_Type;
296 -- Verify that prefix of attribute N is a fixed type
298 procedure Check_Fixed_Point_Type_0;
299 -- Verify that prefix of attribute N is a fixed type and that
300 -- no attribute expressions are present
302 procedure Check_Floating_Point_Type;
303 -- Verify that prefix of attribute N is a float type
305 procedure Check_Floating_Point_Type_0;
306 -- Verify that prefix of attribute N is a float type and that
307 -- no attribute expressions are present
309 procedure Check_Floating_Point_Type_1;
310 -- Verify that prefix of attribute N is a float type and that
311 -- exactly one attribute expression is present
313 procedure Check_Floating_Point_Type_2;
314 -- Verify that prefix of attribute N is a float type and that
315 -- two attribute expressions are present
317 procedure Check_SPARK_Restriction_On_Attribute;
318 -- Issue an error in formal mode because attribute N is allowed
320 procedure Check_Integer_Type;
321 -- Verify that prefix of attribute N is an integer type
323 procedure Check_Modular_Integer_Type;
324 -- Verify that prefix of attribute N is a modular integer type
326 procedure Check_Not_CPP_Type;
327 -- Check that P (the prefix of the attribute) is not an CPP type
328 -- for which no Ada predefined primitive is available.
330 procedure Check_Not_Incomplete_Type;
331 -- Check that P (the prefix of the attribute) is not an incomplete
332 -- type or a private type for which no full view has been given.
334 procedure Check_Object_Reference (P : Node_Id);
335 -- Check that P is an object reference
337 procedure Check_Program_Unit;
338 -- Verify that prefix of attribute N is a program unit
340 procedure Check_Real_Type;
341 -- Verify that prefix of attribute N is fixed or float type
343 procedure Check_Scalar_Type;
344 -- Verify that prefix of attribute N is a scalar type
346 procedure Check_Standard_Prefix;
347 -- Verify that prefix of attribute N is package Standard. Also checks
348 -- that there are no arguments.
350 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
351 -- Validity checking for stream attribute. Nam is the TSS name of the
352 -- corresponding possible defined attribute function (e.g. for the
353 -- Read attribute, Nam will be TSS_Stream_Read).
355 procedure Check_System_Prefix;
356 -- Verify that prefix of attribute N is package System
358 procedure Check_PolyORB_Attribute;
359 -- Validity checking for PolyORB/DSA attribute
361 procedure Check_Task_Prefix;
362 -- Verify that prefix of attribute N is a task or task type
364 procedure Check_Type;
365 -- Verify that the prefix of attribute N is a type
367 procedure Check_Unit_Name (Nod : Node_Id);
368 -- Check that Nod is of the form of a library unit name, i.e that
369 -- it is an identifier, or a selected component whose prefix is
370 -- itself of the form of a library unit name. Note that this is
371 -- quite different from Check_Program_Unit, since it only checks
372 -- the syntactic form of the name, not the semantic identity. This
373 -- is because it is used with attributes (Elab_Body, Elab_Spec,
374 -- UET_Address and Elaborated) which can refer to non-visible unit.
376 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
377 pragma No_Return (Error_Attr);
378 procedure Error_Attr;
379 pragma No_Return (Error_Attr);
380 -- Posts error using Error_Msg_N at given node, sets type of attribute
381 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
382 -- semantic processing. The message typically contains a % insertion
383 -- character which is replaced by the attribute name. The call with
384 -- no arguments is used when the caller has already generated the
385 -- required error messages.
387 procedure Error_Attr_P (Msg : String);
388 pragma No_Return (Error_Attr);
389 -- Like Error_Attr, but error is posted at the start of the prefix
391 function In_Refined_Post return Boolean;
392 -- Determine whether the current attribute appears in pragma
395 procedure Legal_Formal_Attribute;
396 -- Common processing for attributes Definite and Has_Discriminants.
397 -- Checks that prefix is generic indefinite formal type.
399 procedure Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements;
400 -- Common processing for attributes Max_Alignment_For_Allocation and
401 -- Max_Size_In_Storage_Elements.
404 -- Common processing for attributes Max and Min
406 procedure Standard_Attribute (Val : Int);
407 -- Used to process attributes whose prefix is package Standard which
408 -- yield values of type Universal_Integer. The attribute reference
409 -- node is rewritten with an integer literal of the given value.
411 procedure Unexpected_Argument (En : Node_Id);
412 -- Signal unexpected attribute argument (En is the argument)
414 procedure Validate_Non_Static_Attribute_Function_Call;
415 -- Called when processing an attribute that is a function call to a
416 -- non-static function, i.e. an attribute function that either takes
417 -- non-scalar arguments or returns a non-scalar result. Verifies that
418 -- such a call does not appear in a preelaborable context.
424 procedure Address_Checks is
426 -- An Address attribute created by expansion is legal even when it
427 -- applies to other entity-denoting expressions.
429 if not Comes_From_Source (N) then
432 -- Address attribute on a protected object self reference is legal
434 elsif Is_Protected_Self_Reference (P) then
437 -- Address applied to an entity
439 elsif Is_Entity_Name (P) then
441 Ent : constant Entity_Id := Entity (P);
444 if Is_Subprogram (Ent) then
445 Set_Address_Taken (Ent);
446 Kill_Current_Values (Ent);
448 -- An Address attribute is accepted when generated by the
449 -- compiler for dispatching operation, and an error is
450 -- issued once the subprogram is frozen (to avoid confusing
451 -- errors about implicit uses of Address in the dispatch
452 -- table initialization).
454 if Has_Pragma_Inline_Always (Entity (P))
455 and then Comes_From_Source (P)
458 ("prefix of % attribute cannot be Inline_Always "
461 -- It is illegal to apply 'Address to an intrinsic
462 -- subprogram. This is now formalized in AI05-0095.
463 -- In an instance, an attempt to obtain 'Address of an
464 -- intrinsic subprogram (e.g the renaming of a predefined
465 -- operator that is an actual) raises Program_Error.
467 elsif Convention (Ent) = Convention_Intrinsic then
470 Make_Raise_Program_Error (Loc,
471 Reason => PE_Address_Of_Intrinsic));
474 Error_Msg_Name_1 := Aname;
476 ("cannot take % of intrinsic subprogram", N);
479 -- Issue an error if prefix denotes an eliminated subprogram
482 Check_For_Eliminated_Subprogram (P, Ent);
485 -- Object or label reference
487 elsif Is_Object (Ent) or else Ekind (Ent) = E_Label then
488 Set_Address_Taken (Ent);
490 -- Deal with No_Implicit_Aliasing restriction
492 if Restriction_Check_Required (No_Implicit_Aliasing) then
493 if not Is_Aliased_View (P) then
494 Check_Restriction (No_Implicit_Aliasing, P);
496 Check_No_Implicit_Aliasing (P);
500 -- If we have an address of an object, and the attribute
501 -- comes from source, then set the object as potentially
502 -- source modified. We do this because the resulting address
503 -- can potentially be used to modify the variable and we
504 -- might not detect this, leading to some junk warnings.
506 Set_Never_Set_In_Source (Ent, False);
508 -- Allow Address to be applied to task or protected type,
509 -- returning null address (what is that about???)
511 elsif (Is_Concurrent_Type (Etype (Ent))
512 and then Etype (Ent) = Base_Type (Ent))
513 or else Ekind (Ent) = E_Package
514 or else Is_Generic_Unit (Ent)
517 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
519 -- Anything else is illegal
522 Error_Attr ("invalid prefix for % attribute", P);
526 -- Allow Address if the prefix is a reference to the AST_Entry
527 -- attribute. If expansion is active, the attribute will be
528 -- replaced by a function call, and address will work fine and
529 -- get the proper value, but if expansion is not active, then
530 -- the check here allows proper semantic analysis of the reference.
532 elsif Nkind (P) = N_Attribute_Reference
533 and then Attribute_Name (P) = Name_AST_Entry
536 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
540 elsif Is_Object_Reference (P) then
543 -- Subprogram called using dot notation
545 elsif Nkind (P) = N_Selected_Component
546 and then Is_Subprogram (Entity (Selector_Name (P)))
550 -- What exactly are we allowing here ??? and is this properly
551 -- documented in the sinfo documentation for this node ???
553 elsif Relaxed_RM_Semantics
554 and then Nkind (P) = N_Attribute_Reference
558 -- All other non-entity name cases are illegal
561 Error_Attr ("invalid prefix for % attribute", P);
565 ------------------------------
566 -- Analyze_Access_Attribute --
567 ------------------------------
569 procedure Analyze_Access_Attribute is
570 Acc_Type : Entity_Id;
575 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
576 -- Build an access-to-object type whose designated type is DT,
577 -- and whose Ekind is appropriate to the attribute type. The
578 -- type that is constructed is returned as the result.
580 procedure Build_Access_Subprogram_Type (P : Node_Id);
581 -- Build an access to subprogram whose designated type is the type of
582 -- the prefix. If prefix is overloaded, so is the node itself. The
583 -- result is stored in Acc_Type.
585 function OK_Self_Reference return Boolean;
586 -- An access reference whose prefix is a type can legally appear
587 -- within an aggregate, where it is obtained by expansion of
588 -- a defaulted aggregate. The enclosing aggregate that contains
589 -- the self-referenced is flagged so that the self-reference can
590 -- be expanded into a reference to the target object (see exp_aggr).
592 ------------------------------
593 -- Build_Access_Object_Type --
594 ------------------------------
596 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
597 Typ : constant Entity_Id :=
599 (E_Access_Attribute_Type, Current_Scope, Loc, 'A');
601 Set_Etype (Typ, Typ);
603 Set_Associated_Node_For_Itype (Typ, N);
604 Set_Directly_Designated_Type (Typ, DT);
606 end Build_Access_Object_Type;
608 ----------------------------------
609 -- Build_Access_Subprogram_Type --
610 ----------------------------------
612 procedure Build_Access_Subprogram_Type (P : Node_Id) is
613 Index : Interp_Index;
616 procedure Check_Local_Access (E : Entity_Id);
617 -- Deal with possible access to local subprogram. If we have such
618 -- an access, we set a flag to kill all tracked values on any call
619 -- because this access value may be passed around, and any called
620 -- code might use it to access a local procedure which clobbers a
621 -- tracked value. If the scope is a loop or block, indicate that
622 -- value tracking is disabled for the enclosing subprogram.
624 function Get_Kind (E : Entity_Id) return Entity_Kind;
625 -- Distinguish between access to regular/protected subprograms
627 ------------------------
628 -- Check_Local_Access --
629 ------------------------
631 procedure Check_Local_Access (E : Entity_Id) is
633 if not Is_Library_Level_Entity (E) then
634 Set_Suppress_Value_Tracking_On_Call (Current_Scope);
635 Set_Suppress_Value_Tracking_On_Call
636 (Nearest_Dynamic_Scope (Current_Scope));
638 end Check_Local_Access;
644 function Get_Kind (E : Entity_Id) return Entity_Kind is
646 if Convention (E) = Convention_Protected then
647 return E_Access_Protected_Subprogram_Type;
649 return E_Access_Subprogram_Type;
653 -- Start of processing for Build_Access_Subprogram_Type
656 -- In the case of an access to subprogram, use the name of the
657 -- subprogram itself as the designated type. Type-checking in
658 -- this case compares the signatures of the designated types.
660 -- Note: This fragment of the tree is temporarily malformed
661 -- because the correct tree requires an E_Subprogram_Type entity
662 -- as the designated type. In most cases this designated type is
663 -- later overridden by the semantics with the type imposed by the
664 -- context during the resolution phase. In the specific case of
665 -- the expression Address!(Prim'Unrestricted_Access), used to
666 -- initialize slots of dispatch tables, this work will be done by
667 -- the expander (see Exp_Aggr).
669 -- The reason to temporarily add this kind of node to the tree
670 -- instead of a proper E_Subprogram_Type itype, is the following:
671 -- in case of errors found in the source file we report better
672 -- error messages. For example, instead of generating the
675 -- "expected access to subprogram with profile
676 -- defined at line X"
678 -- we currently generate:
680 -- "expected access to function Z defined at line X"
682 Set_Etype (N, Any_Type);
684 if not Is_Overloaded (P) then
685 Check_Local_Access (Entity (P));
687 if not Is_Intrinsic_Subprogram (Entity (P)) then
688 Acc_Type := Create_Itype (Get_Kind (Entity (P)), N);
689 Set_Is_Public (Acc_Type, False);
690 Set_Etype (Acc_Type, Acc_Type);
691 Set_Convention (Acc_Type, Convention (Entity (P)));
692 Set_Directly_Designated_Type (Acc_Type, Entity (P));
693 Set_Etype (N, Acc_Type);
694 Freeze_Before (N, Acc_Type);
698 Get_First_Interp (P, Index, It);
699 while Present (It.Nam) loop
700 Check_Local_Access (It.Nam);
702 if not Is_Intrinsic_Subprogram (It.Nam) then
703 Acc_Type := Create_Itype (Get_Kind (It.Nam), N);
704 Set_Is_Public (Acc_Type, False);
705 Set_Etype (Acc_Type, Acc_Type);
706 Set_Convention (Acc_Type, Convention (It.Nam));
707 Set_Directly_Designated_Type (Acc_Type, It.Nam);
708 Add_One_Interp (N, Acc_Type, Acc_Type);
709 Freeze_Before (N, Acc_Type);
712 Get_Next_Interp (Index, It);
716 -- Cannot be applied to intrinsic. Looking at the tests above,
717 -- the only way Etype (N) can still be set to Any_Type is if
718 -- Is_Intrinsic_Subprogram was True for some referenced entity.
720 if Etype (N) = Any_Type then
721 Error_Attr_P ("prefix of % attribute cannot be intrinsic");
723 end Build_Access_Subprogram_Type;
725 ----------------------
726 -- OK_Self_Reference --
727 ----------------------
729 function OK_Self_Reference return Boolean is
736 (Nkind (Par) = N_Component_Association
737 or else Nkind (Par) in N_Subexpr)
739 if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
740 if Etype (Par) = Typ then
741 Set_Has_Self_Reference (Par);
749 -- No enclosing aggregate, or not a self-reference
752 end OK_Self_Reference;
754 -- Start of processing for Analyze_Access_Attribute
757 Check_SPARK_Restriction_On_Attribute;
760 if Nkind (P) = N_Character_Literal then
762 ("prefix of % attribute cannot be enumeration literal");
765 -- Case of access to subprogram
767 if Is_Entity_Name (P) and then Is_Overloadable (Entity (P)) then
768 if Has_Pragma_Inline_Always (Entity (P)) then
770 ("prefix of % attribute cannot be Inline_Always subprogram");
772 elsif Aname = Name_Unchecked_Access then
773 Error_Attr ("attribute% cannot be applied to a subprogram", P);
775 elsif Is_Ghost_Subprogram (Entity (P)) then
777 ("prefix of % attribute cannot be a ghost subprogram");
780 -- Issue an error if the prefix denotes an eliminated subprogram
782 Check_For_Eliminated_Subprogram (P, Entity (P));
784 -- Check for obsolescent subprogram reference
786 Check_Obsolescent_2005_Entity (Entity (P), P);
788 -- Build the appropriate subprogram type
790 Build_Access_Subprogram_Type (P);
792 -- For P'Access or P'Unrestricted_Access, where P is a nested
793 -- subprogram, we might be passing P to another subprogram (but we
794 -- don't check that here), which might call P. P could modify
795 -- local variables, so we need to kill current values. It is
796 -- important not to do this for library-level subprograms, because
797 -- Kill_Current_Values is very inefficient in the case of library
798 -- level packages with lots of tagged types.
800 if Is_Library_Level_Entity (Entity (Prefix (N))) then
803 -- Do not kill values on nodes initializing dispatch tables
804 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
805 -- is currently generated by the expander only for this
806 -- purpose. Done to keep the quality of warnings currently
807 -- generated by the compiler (otherwise any declaration of
808 -- a tagged type cleans constant indications from its scope).
810 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
811 and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr)
813 Etype (Parent (N)) = RTE (RE_Size_Ptr))
814 and then Is_Dispatching_Operation
815 (Directly_Designated_Type (Etype (N)))
823 -- In the static elaboration model, treat the attribute reference
824 -- as a call for elaboration purposes. Suppress this treatment
825 -- under debug flag. In any case, we are all done.
827 if not Dynamic_Elaboration_Checks and not Debug_Flag_Dot_UU then
833 -- Component is an operation of a protected type
835 elsif Nkind (P) = N_Selected_Component
836 and then Is_Overloadable (Entity (Selector_Name (P)))
838 if Ekind (Entity (Selector_Name (P))) = E_Entry then
839 Error_Attr_P ("prefix of % attribute must be subprogram");
842 Build_Access_Subprogram_Type (Selector_Name (P));
846 -- Deal with incorrect reference to a type, but note that some
847 -- accesses are allowed: references to the current type instance,
848 -- or in Ada 2005 self-referential pointer in a default-initialized
851 if Is_Entity_Name (P) then
854 -- The reference may appear in an aggregate that has been expanded
855 -- into a loop. Locate scope of type definition, if any.
857 Scop := Current_Scope;
858 while Ekind (Scop) = E_Loop loop
859 Scop := Scope (Scop);
862 if Is_Type (Typ) then
864 -- OK if we are within the scope of a limited type
865 -- let's mark the component as having per object constraint
867 if Is_Anonymous_Tagged_Base (Scop, Typ) then
875 Q : Node_Id := Parent (N);
879 and then Nkind (Q) /= N_Component_Declaration
885 Set_Has_Per_Object_Constraint
886 (Defining_Identifier (Q), True);
890 if Nkind (P) = N_Expanded_Name then
892 ("current instance prefix must be a direct name", P);
895 -- If a current instance attribute appears in a component
896 -- constraint it must appear alone; other contexts (spec-
897 -- expressions, within a task body) are not subject to this
900 if not In_Spec_Expression
901 and then not Has_Completion (Scop)
903 Nkind_In (Parent (N), N_Discriminant_Association,
904 N_Index_Or_Discriminant_Constraint)
907 ("current instance attribute must appear alone", N);
910 if Is_CPP_Class (Root_Type (Typ)) then
912 ("??current instance unsupported for derivations of "
913 & "'C'P'P types", N);
916 -- OK if we are in initialization procedure for the type
917 -- in question, in which case the reference to the type
918 -- is rewritten as a reference to the current object.
920 elsif Ekind (Scop) = E_Procedure
921 and then Is_Init_Proc (Scop)
922 and then Etype (First_Formal (Scop)) = Typ
925 Make_Attribute_Reference (Loc,
926 Prefix => Make_Identifier (Loc, Name_uInit),
927 Attribute_Name => Name_Unrestricted_Access));
931 -- OK if a task type, this test needs sharpening up ???
933 elsif Is_Task_Type (Typ) then
936 -- OK if self-reference in an aggregate in Ada 2005, and
937 -- the reference comes from a copied default expression.
939 -- Note that we check legality of self-reference even if the
940 -- expression comes from source, e.g. when a single component
941 -- association in an aggregate has a box association.
943 elsif Ada_Version >= Ada_2005
944 and then OK_Self_Reference
948 -- OK if reference to current instance of a protected object
950 elsif Is_Protected_Self_Reference (P) then
953 -- Otherwise we have an error case
956 Error_Attr ("% attribute cannot be applied to type", P);
962 -- If we fall through, we have a normal access to object case
964 -- Unrestricted_Access is (for now) legal wherever an allocator would
965 -- be legal, so its Etype is set to E_Allocator. The expected type
966 -- of the other attributes is a general access type, and therefore
967 -- we label them with E_Access_Attribute_Type.
969 if not Is_Overloaded (P) then
970 Acc_Type := Build_Access_Object_Type (P_Type);
971 Set_Etype (N, Acc_Type);
975 Index : Interp_Index;
978 Set_Etype (N, Any_Type);
979 Get_First_Interp (P, Index, It);
980 while Present (It.Typ) loop
981 Acc_Type := Build_Access_Object_Type (It.Typ);
982 Add_One_Interp (N, Acc_Type, Acc_Type);
983 Get_Next_Interp (Index, It);
988 -- Special cases when we can find a prefix that is an entity name
997 if Is_Entity_Name (PP) then
1000 -- If we have an access to an object, and the attribute
1001 -- comes from source, then set the object as potentially
1002 -- source modified. We do this because the resulting access
1003 -- pointer can be used to modify the variable, and we might
1004 -- not detect this, leading to some junk warnings.
1006 Set_Never_Set_In_Source (Ent, False);
1008 -- Mark entity as address taken, and kill current values
1010 Set_Address_Taken (Ent);
1011 Kill_Current_Values (Ent);
1014 elsif Nkind_In (PP, N_Selected_Component,
1015 N_Indexed_Component)
1025 -- Check for aliased view.. We allow a nonaliased prefix when within
1026 -- an instance because the prefix may have been a tagged formal
1027 -- object, which is defined to be aliased even when the actual
1028 -- might not be (other instance cases will have been caught in the
1029 -- generic). Similarly, within an inlined body we know that the
1030 -- attribute is legal in the original subprogram, and therefore
1031 -- legal in the expansion.
1033 if not Is_Aliased_View (P)
1034 and then not In_Instance
1035 and then not In_Inlined_Body
1037 -- Here we have a non-aliased view. This is illegal unless we
1038 -- have the case of Unrestricted_Access, where for now we allow
1039 -- this (we will reject later if expected type is access to an
1040 -- unconstrained array with a thin pointer).
1042 if Aname /= Name_Unrestricted_Access then
1043 Error_Attr_P ("prefix of % attribute must be aliased");
1044 Check_No_Implicit_Aliasing (P);
1046 -- For Unrestricted_Access, record that prefix is not aliased
1047 -- to simplify legality check later on.
1050 Set_Non_Aliased_Prefix (N);
1053 -- If we have an aliased view, and we have Unrestricted_Access, then
1054 -- output a warning that Unchecked_Access would have been fine, and
1055 -- change the node to be Unchecked_Access.
1058 -- For now, hold off on this change ???
1062 end Analyze_Access_Attribute;
1064 ---------------------------------
1065 -- Bad_Attribute_For_Predicate --
1066 ---------------------------------
1068 procedure Bad_Attribute_For_Predicate is
1070 if Is_Scalar_Type (P_Type)
1071 and then Comes_From_Source (N)
1073 Error_Msg_Name_1 := Aname;
1074 Bad_Predicated_Subtype_Use
1075 ("type& has predicates, attribute % not allowed", N, P_Type);
1077 end Bad_Attribute_For_Predicate;
1079 ------------------------------
1080 -- Check_Ada_2012_Attribute --
1081 ------------------------------
1083 procedure Check_Ada_2012_Attribute is
1085 Error_Msg_Name_1 := Aname;
1086 Error_Msg_Ada_2012_Feature ("attribute %", Sloc (N));
1087 end Check_Ada_2012_Attribute;
1089 --------------------------------
1090 -- Check_Array_Or_Scalar_Type --
1091 --------------------------------
1093 procedure Check_Array_Or_Scalar_Type is
1097 -- Dimension number for array attributes
1100 -- Case of string literal or string literal subtype. These cases
1101 -- cannot arise from legal Ada code, but the expander is allowed
1102 -- to generate them. They require special handling because string
1103 -- literal subtypes do not have standard bounds (the whole idea
1104 -- of these subtypes is to avoid having to generate the bounds)
1106 if Ekind (P_Type) = E_String_Literal_Subtype then
1107 Set_Etype (N, Etype (First_Index (P_Base_Type)));
1112 elsif Is_Scalar_Type (P_Type) then
1115 if Present (E1) then
1116 Error_Attr ("invalid argument in % attribute", E1);
1118 Set_Etype (N, P_Base_Type);
1122 -- The following is a special test to allow 'First to apply to
1123 -- private scalar types if the attribute comes from generated
1124 -- code. This occurs in the case of Normalize_Scalars code.
1126 elsif Is_Private_Type (P_Type)
1127 and then Present (Full_View (P_Type))
1128 and then Is_Scalar_Type (Full_View (P_Type))
1129 and then not Comes_From_Source (N)
1131 Set_Etype (N, Implementation_Base_Type (P_Type));
1133 -- Array types other than string literal subtypes handled above
1138 -- We know prefix is an array type, or the name of an array
1139 -- object, and that the expression, if present, is static
1140 -- and within the range of the dimensions of the type.
1142 pragma Assert (Is_Array_Type (P_Type));
1143 Index := First_Index (P_Base_Type);
1147 -- First dimension assumed
1149 Set_Etype (N, Base_Type (Etype (Index)));
1152 D := UI_To_Int (Intval (E1));
1154 for J in 1 .. D - 1 loop
1158 Set_Etype (N, Base_Type (Etype (Index)));
1159 Set_Etype (E1, Standard_Integer);
1162 end Check_Array_Or_Scalar_Type;
1164 ----------------------
1165 -- Check_Array_Type --
1166 ----------------------
1168 procedure Check_Array_Type is
1170 -- Dimension number for array attributes
1173 -- If the type is a string literal type, then this must be generated
1174 -- internally, and no further check is required on its legality.
1176 if Ekind (P_Type) = E_String_Literal_Subtype then
1179 -- If the type is a composite, it is an illegal aggregate, no point
1182 elsif P_Type = Any_Composite then
1183 raise Bad_Attribute;
1186 -- Normal case of array type or subtype
1188 Check_Either_E0_Or_E1;
1191 if Is_Array_Type (P_Type) then
1192 if not Is_Constrained (P_Type)
1193 and then Is_Entity_Name (P)
1194 and then Is_Type (Entity (P))
1196 -- Note: we do not call Error_Attr here, since we prefer to
1197 -- continue, using the relevant index type of the array,
1198 -- even though it is unconstrained. This gives better error
1199 -- recovery behavior.
1201 Error_Msg_Name_1 := Aname;
1203 ("prefix for % attribute must be constrained array", P);
1206 -- The attribute reference freezes the type, and thus the
1207 -- component type, even if the attribute may not depend on the
1208 -- component. Diagnose arrays with incomplete components now.
1209 -- If the prefix is an access to array, this does not freeze
1210 -- the designated type.
1212 if Nkind (P) /= N_Explicit_Dereference then
1213 Check_Fully_Declared (Component_Type (P_Type), P);
1216 D := Number_Dimensions (P_Type);
1219 if Is_Private_Type (P_Type) then
1220 Error_Attr_P ("prefix for % attribute may not be private type");
1222 elsif Is_Access_Type (P_Type)
1223 and then Is_Array_Type (Designated_Type (P_Type))
1224 and then Is_Entity_Name (P)
1225 and then Is_Type (Entity (P))
1227 Error_Attr_P ("prefix of % attribute cannot be access type");
1229 elsif Attr_Id = Attribute_First
1231 Attr_Id = Attribute_Last
1233 Error_Attr ("invalid prefix for % attribute", P);
1236 Error_Attr_P ("prefix for % attribute must be array");
1240 if Present (E1) then
1241 Resolve (E1, Any_Integer);
1242 Set_Etype (E1, Standard_Integer);
1244 if not Is_Static_Expression (E1)
1245 or else Raises_Constraint_Error (E1)
1247 Flag_Non_Static_Expr
1248 ("expression for dimension must be static!", E1);
1251 elsif UI_To_Int (Expr_Value (E1)) > D
1252 or else UI_To_Int (Expr_Value (E1)) < 1
1254 Error_Attr ("invalid dimension number for array type", E1);
1258 if (Style_Check and Style_Check_Array_Attribute_Index)
1259 and then Comes_From_Source (N)
1261 Style.Check_Array_Attribute_Index (N, E1, D);
1263 end Check_Array_Type;
1265 -------------------------
1266 -- Check_Asm_Attribute --
1267 -------------------------
1269 procedure Check_Asm_Attribute is
1274 -- Check first argument is static string expression
1276 Analyze_And_Resolve (E1, Standard_String);
1278 if Etype (E1) = Any_Type then
1281 elsif not Is_OK_Static_Expression (E1) then
1282 Flag_Non_Static_Expr
1283 ("constraint argument must be static string expression!", E1);
1287 -- Check second argument is right type
1289 Analyze_And_Resolve (E2, Entity (P));
1291 -- Note: that is all we need to do, we don't need to check
1292 -- that it appears in a correct context. The Ada type system
1293 -- will do that for us.
1295 end Check_Asm_Attribute;
1297 ---------------------
1298 -- Check_Component --
1299 ---------------------
1301 procedure Check_Component is
1305 if Nkind (P) /= N_Selected_Component
1307 (Ekind (Entity (Selector_Name (P))) /= E_Component
1309 Ekind (Entity (Selector_Name (P))) /= E_Discriminant)
1311 Error_Attr_P ("prefix for % attribute must be selected component");
1313 end Check_Component;
1315 ------------------------------------
1316 -- Check_Decimal_Fixed_Point_Type --
1317 ------------------------------------
1319 procedure Check_Decimal_Fixed_Point_Type is
1323 if not Is_Decimal_Fixed_Point_Type (P_Type) then
1324 Error_Attr_P ("prefix of % attribute must be decimal type");
1326 end Check_Decimal_Fixed_Point_Type;
1328 -----------------------
1329 -- Check_Dereference --
1330 -----------------------
1332 procedure Check_Dereference is
1335 -- Case of a subtype mark
1337 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
1341 -- Case of an expression
1345 if Is_Access_Type (P_Type) then
1347 -- If there is an implicit dereference, then we must freeze the
1348 -- designated type of the access type, since the type of the
1349 -- referenced array is this type (see AI95-00106).
1351 -- As done elsewhere, freezing must not happen when pre-analyzing
1352 -- a pre- or postcondition or a default value for an object or for
1353 -- a formal parameter.
1355 if not In_Spec_Expression then
1356 Freeze_Before (N, Designated_Type (P_Type));
1360 Make_Explicit_Dereference (Sloc (P),
1361 Prefix => Relocate_Node (P)));
1363 Analyze_And_Resolve (P);
1364 P_Type := Etype (P);
1366 if P_Type = Any_Type then
1367 raise Bad_Attribute;
1370 P_Base_Type := Base_Type (P_Type);
1372 end Check_Dereference;
1374 -------------------------
1375 -- Check_Discrete_Type --
1376 -------------------------
1378 procedure Check_Discrete_Type is
1382 if not Is_Discrete_Type (P_Type) then
1383 Error_Attr_P ("prefix of % attribute must be discrete type");
1385 end Check_Discrete_Type;
1391 procedure Check_E0 is
1393 if Present (E1) then
1394 Unexpected_Argument (E1);
1402 procedure Check_E1 is
1404 Check_Either_E0_Or_E1;
1408 -- Special-case attributes that are functions and that appear as
1409 -- the prefix of another attribute. Error is posted on parent.
1411 if Nkind (Parent (N)) = N_Attribute_Reference
1412 and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
1416 Error_Msg_Name_1 := Attribute_Name (Parent (N));
1417 Error_Msg_N ("illegal prefix for % attribute", Parent (N));
1418 Set_Etype (Parent (N), Any_Type);
1419 Set_Entity (Parent (N), Any_Type);
1420 raise Bad_Attribute;
1423 Error_Attr ("missing argument for % attribute", N);
1432 procedure Check_E2 is
1435 Error_Attr ("missing arguments for % attribute (2 required)", N);
1437 Error_Attr ("missing argument for % attribute (2 required)", N);
1441 ---------------------------
1442 -- Check_Either_E0_Or_E1 --
1443 ---------------------------
1445 procedure Check_Either_E0_Or_E1 is
1447 if Present (E2) then
1448 Unexpected_Argument (E2);
1450 end Check_Either_E0_Or_E1;
1452 ----------------------
1453 -- Check_Enum_Image --
1454 ----------------------
1456 procedure Check_Enum_Image is
1460 -- When an enumeration type appears in an attribute reference, all
1461 -- literals of the type are marked as referenced. This must only be
1462 -- done if the attribute reference appears in the current source.
1463 -- Otherwise the information on references may differ between a
1464 -- normal compilation and one that performs inlining.
1466 if Is_Enumeration_Type (P_Base_Type)
1467 and then In_Extended_Main_Code_Unit (N)
1469 Lit := First_Literal (P_Base_Type);
1470 while Present (Lit) loop
1471 Set_Referenced (Lit);
1475 end Check_Enum_Image;
1477 ----------------------------
1478 -- Check_First_Last_Valid --
1479 ----------------------------
1481 procedure Check_First_Last_Valid is
1483 Check_Ada_2012_Attribute;
1484 Check_Discrete_Type;
1486 -- Freeze the subtype now, so that the following test for predicates
1487 -- works (we set the predicates stuff up at freeze time)
1489 Insert_Actions (N, Freeze_Entity (P_Type, P));
1491 -- Now test for dynamic predicate
1493 if Has_Predicates (P_Type)
1494 and then No (Static_Predicate (P_Type))
1497 ("prefix of % attribute may not have dynamic predicate");
1500 -- Check non-static subtype
1502 if not Is_Static_Subtype (P_Type) then
1503 Error_Attr_P ("prefix of % attribute must be a static subtype");
1506 -- Test case for no values
1508 if Expr_Value (Type_Low_Bound (P_Type)) >
1509 Expr_Value (Type_High_Bound (P_Type))
1510 or else (Has_Predicates (P_Type)
1511 and then Is_Empty_List (Static_Predicate (P_Type)))
1514 ("prefix of % attribute must be subtype with "
1515 & "at least one value");
1517 end Check_First_Last_Valid;
1519 ----------------------------
1520 -- Check_Fixed_Point_Type --
1521 ----------------------------
1523 procedure Check_Fixed_Point_Type is
1527 if not Is_Fixed_Point_Type (P_Type) then
1528 Error_Attr_P ("prefix of % attribute must be fixed point type");
1530 end Check_Fixed_Point_Type;
1532 ------------------------------
1533 -- Check_Fixed_Point_Type_0 --
1534 ------------------------------
1536 procedure Check_Fixed_Point_Type_0 is
1538 Check_Fixed_Point_Type;
1540 end Check_Fixed_Point_Type_0;
1542 -------------------------------
1543 -- Check_Floating_Point_Type --
1544 -------------------------------
1546 procedure Check_Floating_Point_Type is
1550 if not Is_Floating_Point_Type (P_Type) then
1551 Error_Attr_P ("prefix of % attribute must be float type");
1553 end Check_Floating_Point_Type;
1555 ---------------------------------
1556 -- Check_Floating_Point_Type_0 --
1557 ---------------------------------
1559 procedure Check_Floating_Point_Type_0 is
1561 Check_Floating_Point_Type;
1563 end Check_Floating_Point_Type_0;
1565 ---------------------------------
1566 -- Check_Floating_Point_Type_1 --
1567 ---------------------------------
1569 procedure Check_Floating_Point_Type_1 is
1571 Check_Floating_Point_Type;
1573 end Check_Floating_Point_Type_1;
1575 ---------------------------------
1576 -- Check_Floating_Point_Type_2 --
1577 ---------------------------------
1579 procedure Check_Floating_Point_Type_2 is
1581 Check_Floating_Point_Type;
1583 end Check_Floating_Point_Type_2;
1585 ------------------------
1586 -- Check_Integer_Type --
1587 ------------------------
1589 procedure Check_Integer_Type is
1593 if not Is_Integer_Type (P_Type) then
1594 Error_Attr_P ("prefix of % attribute must be integer type");
1596 end Check_Integer_Type;
1598 --------------------------------
1599 -- Check_Modular_Integer_Type --
1600 --------------------------------
1602 procedure Check_Modular_Integer_Type is
1606 if not Is_Modular_Integer_Type (P_Type) then
1608 ("prefix of % attribute must be modular integer type");
1610 end Check_Modular_Integer_Type;
1612 ------------------------
1613 -- Check_Not_CPP_Type --
1614 ------------------------
1616 procedure Check_Not_CPP_Type is
1618 if Is_Tagged_Type (Etype (P))
1619 and then Convention (Etype (P)) = Convention_CPP
1620 and then Is_CPP_Class (Root_Type (Etype (P)))
1623 ("invalid use of % attribute with 'C'P'P tagged type");
1625 end Check_Not_CPP_Type;
1627 -------------------------------
1628 -- Check_Not_Incomplete_Type --
1629 -------------------------------
1631 procedure Check_Not_Incomplete_Type is
1636 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1637 -- dereference we have to check wrong uses of incomplete types
1638 -- (other wrong uses are checked at their freezing point).
1640 -- Example 1: Limited-with
1642 -- limited with Pkg;
1644 -- type Acc is access Pkg.T;
1646 -- S : Integer := X.all'Size; -- ERROR
1649 -- Example 2: Tagged incomplete
1651 -- type T is tagged;
1652 -- type Acc is access all T;
1654 -- S : constant Integer := X.all'Size; -- ERROR
1655 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1657 if Ada_Version >= Ada_2005
1658 and then Nkind (P) = N_Explicit_Dereference
1661 while Nkind (E) = N_Explicit_Dereference loop
1667 if From_Limited_With (Typ) then
1669 ("prefix of % attribute cannot be an incomplete type");
1672 if Is_Access_Type (Typ) then
1673 Typ := Directly_Designated_Type (Typ);
1676 if Is_Class_Wide_Type (Typ) then
1677 Typ := Root_Type (Typ);
1680 -- A legal use of a shadow entity occurs only when the unit
1681 -- where the non-limited view resides is imported via a regular
1682 -- with clause in the current body. Such references to shadow
1683 -- entities may occur in subprogram formals.
1685 if Is_Incomplete_Type (Typ)
1686 and then From_Limited_With (Typ)
1687 and then Present (Non_Limited_View (Typ))
1688 and then Is_Legal_Shadow_Entity_In_Body (Typ)
1690 Typ := Non_Limited_View (Typ);
1693 if Ekind (Typ) = E_Incomplete_Type
1694 and then No (Full_View (Typ))
1697 ("prefix of % attribute cannot be an incomplete type");
1702 if not Is_Entity_Name (P)
1703 or else not Is_Type (Entity (P))
1704 or else In_Spec_Expression
1708 Check_Fully_Declared (P_Type, P);
1710 end Check_Not_Incomplete_Type;
1712 ----------------------------
1713 -- Check_Object_Reference --
1714 ----------------------------
1716 procedure Check_Object_Reference (P : Node_Id) is
1720 -- If we need an object, and we have a prefix that is the name of
1721 -- a function entity, convert it into a function call.
1723 if Is_Entity_Name (P)
1724 and then Ekind (Entity (P)) = E_Function
1726 Rtyp := Etype (Entity (P));
1729 Make_Function_Call (Sloc (P),
1730 Name => Relocate_Node (P)));
1732 Analyze_And_Resolve (P, Rtyp);
1734 -- Otherwise we must have an object reference
1736 elsif not Is_Object_Reference (P) then
1737 Error_Attr_P ("prefix of % attribute must be object");
1739 end Check_Object_Reference;
1741 ----------------------------
1742 -- Check_PolyORB_Attribute --
1743 ----------------------------
1745 procedure Check_PolyORB_Attribute is
1747 Validate_Non_Static_Attribute_Function_Call;
1752 if Get_PCS_Name /= Name_PolyORB_DSA then
1754 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N);
1756 end Check_PolyORB_Attribute;
1758 ------------------------
1759 -- Check_Program_Unit --
1760 ------------------------
1762 procedure Check_Program_Unit is
1764 if Is_Entity_Name (P) then
1766 K : constant Entity_Kind := Ekind (Entity (P));
1767 T : constant Entity_Id := Etype (Entity (P));
1770 if K in Subprogram_Kind
1771 or else K in Task_Kind
1772 or else K in Protected_Kind
1773 or else K = E_Package
1774 or else K in Generic_Unit_Kind
1775 or else (K = E_Variable
1779 Is_Protected_Type (T)))
1786 Error_Attr_P ("prefix of % attribute must be program unit");
1787 end Check_Program_Unit;
1789 ---------------------
1790 -- Check_Real_Type --
1791 ---------------------
1793 procedure Check_Real_Type is
1797 if not Is_Real_Type (P_Type) then
1798 Error_Attr_P ("prefix of % attribute must be real type");
1800 end Check_Real_Type;
1802 -----------------------
1803 -- Check_Scalar_Type --
1804 -----------------------
1806 procedure Check_Scalar_Type is
1810 if not Is_Scalar_Type (P_Type) then
1811 Error_Attr_P ("prefix of % attribute must be scalar type");
1813 end Check_Scalar_Type;
1815 ------------------------------------------
1816 -- Check_SPARK_Restriction_On_Attribute --
1817 ------------------------------------------
1819 procedure Check_SPARK_Restriction_On_Attribute is
1821 Error_Msg_Name_1 := Aname;
1822 Check_SPARK_Restriction ("attribute % is not allowed", P);
1823 end Check_SPARK_Restriction_On_Attribute;
1825 ---------------------------
1826 -- Check_Standard_Prefix --
1827 ---------------------------
1829 procedure Check_Standard_Prefix is
1833 if Nkind (P) /= N_Identifier or else Chars (P) /= Name_Standard then
1834 Error_Attr ("only allowed prefix for % attribute is Standard", P);
1836 end Check_Standard_Prefix;
1838 ----------------------------
1839 -- Check_Stream_Attribute --
1840 ----------------------------
1842 procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is
1846 In_Shared_Var_Procs : Boolean;
1847 -- True when compiling System.Shared_Storage.Shared_Var_Procs body.
1848 -- For this runtime package (always compiled in GNAT mode), we allow
1849 -- stream attributes references for limited types for the case where
1850 -- shared passive objects are implemented using stream attributes,
1851 -- which is the default in GNAT's persistent storage implementation.
1854 Validate_Non_Static_Attribute_Function_Call;
1856 -- With the exception of 'Input, Stream attributes are procedures,
1857 -- and can only appear at the position of procedure calls. We check
1858 -- for this here, before they are rewritten, to give a more precise
1861 if Nam = TSS_Stream_Input then
1864 elsif Is_List_Member (N)
1865 and then not Nkind_In (Parent (N), N_Procedure_Call_Statement,
1872 ("invalid context for attribute%, which is a procedure", N);
1876 Btyp := Implementation_Base_Type (P_Type);
1878 -- Stream attributes not allowed on limited types unless the
1879 -- attribute reference was generated by the expander (in which
1880 -- case the underlying type will be used, as described in Sinfo),
1881 -- or the attribute was specified explicitly for the type itself
1882 -- or one of its ancestors (taking visibility rules into account if
1883 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
1884 -- (with no visibility restriction).
1887 Gen_Body : constant Node_Id := Enclosing_Generic_Body (N);
1889 if Present (Gen_Body) then
1890 In_Shared_Var_Procs :=
1891 Is_RTE (Corresponding_Spec (Gen_Body), RE_Shared_Var_Procs);
1893 In_Shared_Var_Procs := False;
1897 if (Comes_From_Source (N)
1898 and then not (In_Shared_Var_Procs or In_Instance))
1899 and then not Stream_Attribute_Available (P_Type, Nam)
1900 and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert)
1902 Error_Msg_Name_1 := Aname;
1904 if Is_Limited_Type (P_Type) then
1906 ("limited type& has no% attribute", P, P_Type);
1907 Explain_Limited_Type (P_Type, P);
1910 ("attribute% for type& is not available", P, P_Type);
1914 -- Check restriction violations
1916 -- First check the No_Streams restriction, which prohibits the use
1917 -- of explicit stream attributes in the source program. We do not
1918 -- prevent the occurrence of stream attributes in generated code,
1919 -- for instance those generated implicitly for dispatching purposes.
1921 if Comes_From_Source (N) then
1922 Check_Restriction (No_Streams, P);
1925 -- AI05-0057: if restriction No_Default_Stream_Attributes is active,
1926 -- it is illegal to use a predefined elementary type stream attribute
1927 -- either by itself, or more importantly as part of the attribute
1928 -- subprogram for a composite type. However, if the broader
1929 -- restriction No_Streams is active, stream operations are not
1930 -- generated, and there is no error.
1932 if Restriction_Active (No_Default_Stream_Attributes)
1933 and then not Restriction_Active (No_Streams)
1939 if Nam = TSS_Stream_Input
1941 Nam = TSS_Stream_Read
1944 Type_Without_Stream_Operation (P_Type, TSS_Stream_Read);
1947 Type_Without_Stream_Operation (P_Type, TSS_Stream_Write);
1951 Check_Restriction (No_Default_Stream_Attributes, N);
1954 ("missing user-defined Stream Read or Write for type&",
1956 if not Is_Elementary_Type (P_Type) then
1958 ("\which is a component of type&", N, P_Type);
1964 -- Check special case of Exception_Id and Exception_Occurrence which
1965 -- are not allowed for restriction No_Exception_Registration.
1967 if Restriction_Check_Required (No_Exception_Registration)
1968 and then (Is_RTE (P_Type, RE_Exception_Id)
1970 Is_RTE (P_Type, RE_Exception_Occurrence))
1972 Check_Restriction (No_Exception_Registration, P);
1975 -- Here we must check that the first argument is an access type
1976 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1978 Analyze_And_Resolve (E1);
1981 -- Note: the double call to Root_Type here is needed because the
1982 -- root type of a class-wide type is the corresponding type (e.g.
1983 -- X for X'Class, and we really want to go to the root.)
1985 if not Is_Access_Type (Etyp)
1986 or else Root_Type (Root_Type (Designated_Type (Etyp))) /=
1987 RTE (RE_Root_Stream_Type)
1990 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1);
1993 -- Check that the second argument is of the right type if there is
1994 -- one (the Input attribute has only one argument so this is skipped)
1996 if Present (E2) then
1999 if Nam = TSS_Stream_Read
2000 and then not Is_OK_Variable_For_Out_Formal (E2)
2003 ("second argument of % attribute must be a variable", E2);
2006 Resolve (E2, P_Type);
2010 end Check_Stream_Attribute;
2012 -------------------------
2013 -- Check_System_Prefix --
2014 -------------------------
2016 procedure Check_System_Prefix is
2018 if Nkind (P) /= N_Identifier or else Chars (P) /= Name_System then
2019 Error_Attr ("only allowed prefix for % attribute is System", P);
2021 end Check_System_Prefix;
2023 -----------------------
2024 -- Check_Task_Prefix --
2025 -----------------------
2027 procedure Check_Task_Prefix is
2031 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
2032 -- task interface class-wide types.
2034 if Is_Task_Type (Etype (P))
2035 or else (Is_Access_Type (Etype (P))
2036 and then Is_Task_Type (Designated_Type (Etype (P))))
2037 or else (Ada_Version >= Ada_2005
2038 and then Ekind (Etype (P)) = E_Class_Wide_Type
2039 and then Is_Interface (Etype (P))
2040 and then Is_Task_Interface (Etype (P)))
2045 if Ada_Version >= Ada_2005 then
2047 ("prefix of % attribute must be a task or a task " &
2048 "interface class-wide object");
2051 Error_Attr_P ("prefix of % attribute must be a task");
2054 end Check_Task_Prefix;
2060 -- The possibilities are an entity name denoting a type, or an
2061 -- attribute reference that denotes a type (Base or Class). If
2062 -- the type is incomplete, replace it with its full view.
2064 procedure Check_Type is
2066 if not Is_Entity_Name (P)
2067 or else not Is_Type (Entity (P))
2069 Error_Attr_P ("prefix of % attribute must be a type");
2071 elsif Is_Protected_Self_Reference (P) then
2073 ("prefix of % attribute denotes current instance "
2074 & "(RM 9.4(21/2))");
2076 elsif Ekind (Entity (P)) = E_Incomplete_Type
2077 and then Present (Full_View (Entity (P)))
2079 P_Type := Full_View (Entity (P));
2080 Set_Entity (P, P_Type);
2084 ---------------------
2085 -- Check_Unit_Name --
2086 ---------------------
2088 procedure Check_Unit_Name (Nod : Node_Id) is
2090 if Nkind (Nod) = N_Identifier then
2093 elsif Nkind_In (Nod, N_Selected_Component, N_Expanded_Name) then
2094 Check_Unit_Name (Prefix (Nod));
2096 if Nkind (Selector_Name (Nod)) = N_Identifier then
2101 Error_Attr ("argument for % attribute must be unit name", P);
2102 end Check_Unit_Name;
2108 procedure Error_Attr is
2110 Set_Etype (N, Any_Type);
2111 Set_Entity (N, Any_Type);
2112 raise Bad_Attribute;
2115 procedure Error_Attr (Msg : String; Error_Node : Node_Id) is
2117 Error_Msg_Name_1 := Aname;
2118 Error_Msg_N (Msg, Error_Node);
2126 procedure Error_Attr_P (Msg : String) is
2128 Error_Msg_Name_1 := Aname;
2129 Error_Msg_F (Msg, P);
2133 ---------------------
2134 -- In_Refined_Post --
2135 ---------------------
2137 function In_Refined_Post return Boolean is
2138 function Is_Refined_Post (Prag : Node_Id) return Boolean;
2139 -- Determine whether Prag denotes one of the incarnations of pragma
2140 -- Refined_Post (either as is or pragma Check (Refined_Post, ...).
2142 ---------------------
2143 -- Is_Refined_Post --
2144 ---------------------
2146 function Is_Refined_Post (Prag : Node_Id) return Boolean is
2147 Args : constant List_Id := Pragma_Argument_Associations (Prag);
2148 Nam : constant Name_Id := Pragma_Name (Prag);
2151 if Nam = Name_Refined_Post then
2154 elsif Nam = Name_Check then
2155 pragma Assert (Present (Args));
2157 return Chars (Expression (First (Args))) = Name_Refined_Post;
2161 end Is_Refined_Post;
2167 -- Start of processing for In_Refined_Post
2171 while Present (Stmt) loop
2172 if Nkind (Stmt) = N_Pragma and then Is_Refined_Post (Stmt) then
2175 -- Prevent the search from going too far
2177 elsif Is_Body_Or_Package_Declaration (Stmt) then
2181 Stmt := Parent (Stmt);
2185 end In_Refined_Post;
2187 ----------------------------
2188 -- Legal_Formal_Attribute --
2189 ----------------------------
2191 procedure Legal_Formal_Attribute is
2195 if not Is_Entity_Name (P)
2196 or else not Is_Type (Entity (P))
2198 Error_Attr_P ("prefix of % attribute must be generic type");
2200 elsif Is_Generic_Actual_Type (Entity (P))
2202 or else In_Inlined_Body
2206 elsif Is_Generic_Type (Entity (P)) then
2207 if not Is_Indefinite_Subtype (Entity (P)) then
2209 ("prefix of % attribute must be indefinite generic type");
2214 ("prefix of % attribute must be indefinite generic type");
2217 Set_Etype (N, Standard_Boolean);
2218 end Legal_Formal_Attribute;
2220 ---------------------------------------------------------------
2221 -- Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements --
2222 ---------------------------------------------------------------
2224 procedure Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements is
2228 Check_Not_Incomplete_Type;
2229 Set_Etype (N, Universal_Integer);
2230 end Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements;
2236 procedure Min_Max is
2240 Resolve (E1, P_Base_Type);
2241 Resolve (E2, P_Base_Type);
2242 Set_Etype (N, P_Base_Type);
2244 -- Check for comparison on unordered enumeration type
2246 if Bad_Unordered_Enumeration_Reference (N, P_Base_Type) then
2247 Error_Msg_Sloc := Sloc (P_Base_Type);
2249 ("comparison on unordered enumeration type& declared#?U?",
2254 ------------------------
2255 -- Standard_Attribute --
2256 ------------------------
2258 procedure Standard_Attribute (Val : Int) is
2260 Check_Standard_Prefix;
2261 Rewrite (N, Make_Integer_Literal (Loc, Val));
2263 end Standard_Attribute;
2265 -------------------------
2266 -- Unexpected Argument --
2267 -------------------------
2269 procedure Unexpected_Argument (En : Node_Id) is
2271 Error_Attr ("unexpected argument for % attribute", En);
2272 end Unexpected_Argument;
2274 -------------------------------------------------
2275 -- Validate_Non_Static_Attribute_Function_Call --
2276 -------------------------------------------------
2278 -- This function should be moved to Sem_Dist ???
2280 procedure Validate_Non_Static_Attribute_Function_Call is
2282 if In_Preelaborated_Unit
2283 and then not In_Subprogram_Or_Concurrent_Unit
2285 Flag_Non_Static_Expr
2286 ("non-static function call in preelaborated unit!", N);
2288 end Validate_Non_Static_Attribute_Function_Call;
2290 -- Start of processing for Analyze_Attribute
2293 -- Immediate return if unrecognized attribute (already diagnosed
2294 -- by parser, so there is nothing more that we need to do)
2296 if not Is_Attribute_Name (Aname) then
2297 raise Bad_Attribute;
2300 -- Deal with Ada 83 issues
2302 if Comes_From_Source (N) then
2303 if not Attribute_83 (Attr_Id) then
2304 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2305 Error_Msg_Name_1 := Aname;
2306 Error_Msg_N ("(Ada 83) attribute% is not standard??", N);
2309 if Attribute_Impl_Def (Attr_Id) then
2310 Check_Restriction (No_Implementation_Attributes, N);
2315 -- Deal with Ada 2005 attributes that are
2317 if Attribute_05 (Attr_Id) and then Ada_Version < Ada_2005 then
2318 Check_Restriction (No_Implementation_Attributes, N);
2321 -- Remote access to subprogram type access attribute reference needs
2322 -- unanalyzed copy for tree transformation. The analyzed copy is used
2323 -- for its semantic information (whether prefix is a remote subprogram
2324 -- name), the unanalyzed copy is used to construct new subtree rooted
2325 -- with N_Aggregate which represents a fat pointer aggregate.
2327 if Aname = Name_Access then
2328 Discard_Node (Copy_Separate_Tree (N));
2331 -- Analyze prefix and exit if error in analysis. If the prefix is an
2332 -- incomplete type, use full view if available. Note that there are
2333 -- some attributes for which we do not analyze the prefix, since the
2334 -- prefix is not a normal name, or else needs special handling.
2336 if Aname /= Name_Elab_Body and then
2337 Aname /= Name_Elab_Spec and then
2338 Aname /= Name_Elab_Subp_Body and then
2339 Aname /= Name_UET_Address and then
2340 Aname /= Name_Enabled and then
2344 P_Type := Etype (P);
2346 if Is_Entity_Name (P)
2347 and then Present (Entity (P))
2348 and then Is_Type (Entity (P))
2350 if Ekind (Entity (P)) = E_Incomplete_Type then
2351 P_Type := Get_Full_View (P_Type);
2352 Set_Entity (P, P_Type);
2353 Set_Etype (P, P_Type);
2355 elsif Entity (P) = Current_Scope
2356 and then Is_Record_Type (Entity (P))
2358 -- Use of current instance within the type. Verify that if the
2359 -- attribute appears within a constraint, it yields an access
2360 -- type, other uses are illegal.
2368 and then Nkind (Parent (Par)) /= N_Component_Definition
2370 Par := Parent (Par);
2374 and then Nkind (Par) = N_Subtype_Indication
2376 if Attr_Id /= Attribute_Access
2377 and then Attr_Id /= Attribute_Unchecked_Access
2378 and then Attr_Id /= Attribute_Unrestricted_Access
2381 ("in a constraint the current instance can only"
2382 & " be used with an access attribute", N);
2389 if P_Type = Any_Type then
2390 raise Bad_Attribute;
2393 P_Base_Type := Base_Type (P_Type);
2396 -- Analyze expressions that may be present, exiting if an error occurs
2403 E1 := First (Exprs);
2405 -- Skip analysis for case of Restriction_Set, we do not expect
2406 -- the argument to be analyzed in this case.
2408 if Aname /= Name_Restriction_Set then
2411 -- Check for missing/bad expression (result of previous error)
2413 if No (E1) or else Etype (E1) = Any_Type then
2414 raise Bad_Attribute;
2420 if Present (E2) then
2423 if Etype (E2) = Any_Type then
2424 raise Bad_Attribute;
2427 if Present (Next (E2)) then
2428 Unexpected_Argument (Next (E2));
2433 -- Cases where prefix must be resolvable by itself
2435 if Is_Overloaded (P)
2436 and then Aname /= Name_Access
2437 and then Aname /= Name_Address
2438 and then Aname /= Name_Code_Address
2439 and then Aname /= Name_Result
2440 and then Aname /= Name_Unchecked_Access
2442 -- The prefix must be resolvable by itself, without reference to the
2443 -- attribute. One case that requires special handling is a prefix
2444 -- that is a function name, where one interpretation may be a
2445 -- parameterless call. Entry attributes are handled specially below.
2447 if Is_Entity_Name (P)
2448 and then not Nam_In (Aname, Name_Count, Name_Caller, Name_AST_Entry)
2450 Check_Parameterless_Call (P);
2453 if Is_Overloaded (P) then
2455 -- Ada 2005 (AI-345): Since protected and task types have
2456 -- primitive entry wrappers, the attributes Count, Caller and
2457 -- AST_Entry require a context check
2459 if Nam_In (Aname, Name_Count, Name_Caller, Name_AST_Entry) then
2461 Count : Natural := 0;
2466 Get_First_Interp (P, I, It);
2467 while Present (It.Nam) loop
2468 if Comes_From_Source (It.Nam) then
2474 Get_Next_Interp (I, It);
2478 Error_Attr ("ambiguous prefix for % attribute", P);
2480 Set_Is_Overloaded (P, False);
2485 Error_Attr ("ambiguous prefix for % attribute", P);
2490 -- In SPARK, attributes of private types are only allowed if the full
2491 -- type declaration is visible.
2493 -- Note: the check for Present (Entity (P)) defends against some error
2494 -- conditions where the Entity field is not set.
2496 if Is_Entity_Name (P) and then Present (Entity (P))
2497 and then Is_Type (Entity (P))
2498 and then Is_Private_Type (P_Type)
2499 and then not In_Open_Scopes (Scope (P_Type))
2500 and then not In_Spec_Expression
2502 Check_SPARK_Restriction ("invisible attribute of type", N);
2505 -- Remaining processing depends on attribute
2509 -- Attributes related to Ada 2012 iterators. Attribute specifications
2510 -- exist for these, but they cannot be queried.
2512 when Attribute_Constant_Indexing |
2513 Attribute_Default_Iterator |
2514 Attribute_Implicit_Dereference |
2515 Attribute_Iterator_Element |
2516 Attribute_Iterable |
2517 Attribute_Variable_Indexing =>
2518 Error_Msg_N ("illegal attribute", N);
2520 -- Internal attributes used to deal with Ada 2012 delayed aspects. These
2521 -- were already rejected by the parser. Thus they shouldn't appear here.
2523 when Internal_Attribute_Id =>
2524 raise Program_Error;
2530 when Attribute_Abort_Signal =>
2531 Check_Standard_Prefix;
2532 Rewrite (N, New_Occurrence_Of (Stand.Abort_Signal, Loc));
2539 when Attribute_Access =>
2540 Analyze_Access_Attribute;
2546 when Attribute_Address =>
2549 Set_Etype (N, RTE (RE_Address));
2555 when Attribute_Address_Size =>
2556 Standard_Attribute (System_Address_Size);
2562 when Attribute_Adjacent =>
2563 Check_Floating_Point_Type_2;
2564 Set_Etype (N, P_Base_Type);
2565 Resolve (E1, P_Base_Type);
2566 Resolve (E2, P_Base_Type);
2572 when Attribute_Aft =>
2573 Check_Fixed_Point_Type_0;
2574 Set_Etype (N, Universal_Integer);
2580 when Attribute_Alignment =>
2582 -- Don't we need more checking here, cf Size ???
2585 Check_Not_Incomplete_Type;
2587 Set_Etype (N, Universal_Integer);
2593 when Attribute_Asm_Input =>
2594 Check_Asm_Attribute;
2596 -- The back-end may need to take the address of E2
2598 if Is_Entity_Name (E2) then
2599 Set_Address_Taken (Entity (E2));
2602 Set_Etype (N, RTE (RE_Asm_Input_Operand));
2608 when Attribute_Asm_Output =>
2609 Check_Asm_Attribute;
2611 if Etype (E2) = Any_Type then
2614 elsif Aname = Name_Asm_Output then
2615 if not Is_Variable (E2) then
2617 ("second argument for Asm_Output is not variable", E2);
2621 Note_Possible_Modification (E2, Sure => True);
2623 -- The back-end may need to take the address of E2
2625 if Is_Entity_Name (E2) then
2626 Set_Address_Taken (Entity (E2));
2629 Set_Etype (N, RTE (RE_Asm_Output_Operand));
2635 when Attribute_AST_Entry => AST_Entry : declare
2641 -- Indicates if entry family index is present. Note the coding
2642 -- here handles the entry family case, but in fact it cannot be
2643 -- executed currently, because pragma AST_Entry does not permit
2644 -- the specification of an entry family.
2646 procedure Bad_AST_Entry;
2647 -- Signal a bad AST_Entry pragma
2649 function OK_Entry (E : Entity_Id) return Boolean;
2650 -- Checks that E is of an appropriate entity kind for an entry
2651 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
2652 -- is set True for the entry family case). In the True case,
2653 -- makes sure that Is_AST_Entry is set on the entry.
2659 procedure Bad_AST_Entry is
2661 Error_Attr_P ("prefix for % attribute must be task entry");
2668 function OK_Entry (E : Entity_Id) return Boolean is
2673 Result := (Ekind (E) = E_Entry_Family);
2675 Result := (Ekind (E) = E_Entry);
2679 if not Is_AST_Entry (E) then
2680 Error_Msg_Name_2 := Aname;
2681 Error_Attr ("% attribute requires previous % pragma", P);
2688 -- Start of processing for AST_Entry
2694 -- Deal with entry family case
2696 if Nkind (P) = N_Indexed_Component then
2704 Ptyp := Etype (Pref);
2706 if Ptyp = Any_Type or else Error_Posted (Pref) then
2710 -- If the prefix is a selected component whose prefix is of an
2711 -- access type, then introduce an explicit dereference.
2712 -- ??? Could we reuse Check_Dereference here?
2714 if Nkind (Pref) = N_Selected_Component
2715 and then Is_Access_Type (Ptyp)
2718 Make_Explicit_Dereference (Sloc (Pref),
2719 Relocate_Node (Pref)));
2720 Analyze_And_Resolve (Pref, Designated_Type (Ptyp));
2723 -- Prefix can be of the form a.b, where a is a task object
2724 -- and b is one of the entries of the corresponding task type.
2726 if Nkind (Pref) = N_Selected_Component
2727 and then OK_Entry (Entity (Selector_Name (Pref)))
2728 and then Is_Object_Reference (Prefix (Pref))
2729 and then Is_Task_Type (Etype (Prefix (Pref)))
2733 -- Otherwise the prefix must be an entry of a containing task,
2734 -- or of a variable of the enclosing task type.
2737 if Nkind_In (Pref, N_Identifier, N_Expanded_Name) then
2738 Ent := Entity (Pref);
2740 if not OK_Entry (Ent)
2741 or else not In_Open_Scopes (Scope (Ent))
2751 Set_Etype (N, RTE (RE_AST_Handler));
2754 -----------------------------
2755 -- Atomic_Always_Lock_Free --
2756 -----------------------------
2758 when Attribute_Atomic_Always_Lock_Free =>
2761 Set_Etype (N, Standard_Boolean);
2767 -- Note: when the base attribute appears in the context of a subtype
2768 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2769 -- the following circuit.
2771 when Attribute_Base => Base : declare
2779 if Ada_Version >= Ada_95
2780 and then not Is_Scalar_Type (Typ)
2781 and then not Is_Generic_Type (Typ)
2783 Error_Attr_P ("prefix of Base attribute must be scalar type");
2785 elsif Sloc (Typ) = Standard_Location
2786 and then Base_Type (Typ) = Typ
2787 and then Warn_On_Redundant_Constructs
2789 Error_Msg_NE -- CODEFIX
2790 ("?r?redundant attribute, & is its own base type", N, Typ);
2793 if Nkind (Parent (N)) /= N_Attribute_Reference then
2794 Error_Msg_Name_1 := Aname;
2795 Check_SPARK_Restriction
2796 ("attribute% is only allowed as prefix of another attribute", P);
2799 Set_Etype (N, Base_Type (Entity (P)));
2800 Set_Entity (N, Base_Type (Entity (P)));
2801 Rewrite (N, New_Occurrence_Of (Entity (N), Loc));
2809 when Attribute_Bit => Bit :
2813 if not Is_Object_Reference (P) then
2814 Error_Attr_P ("prefix for % attribute must be object");
2816 -- What about the access object cases ???
2822 Set_Etype (N, Universal_Integer);
2829 when Attribute_Bit_Order => Bit_Order :
2834 if not Is_Record_Type (P_Type) then
2835 Error_Attr_P ("prefix of % attribute must be record type");
2838 if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then
2840 New_Occurrence_Of (RTE (RE_High_Order_First), Loc));
2843 New_Occurrence_Of (RTE (RE_Low_Order_First), Loc));
2846 Set_Etype (N, RTE (RE_Bit_Order));
2849 -- Reset incorrect indication of staticness
2851 Set_Is_Static_Expression (N, False);
2858 -- Note: in generated code, we can have a Bit_Position attribute
2859 -- applied to a (naked) record component (i.e. the prefix is an
2860 -- identifier that references an E_Component or E_Discriminant
2861 -- entity directly, and this is interpreted as expected by Gigi.
2862 -- The following code will not tolerate such usage, but when the
2863 -- expander creates this special case, it marks it as analyzed
2864 -- immediately and sets an appropriate type.
2866 when Attribute_Bit_Position =>
2867 if Comes_From_Source (N) then
2871 Set_Etype (N, Universal_Integer);
2877 when Attribute_Body_Version =>
2880 Set_Etype (N, RTE (RE_Version_String));
2886 when Attribute_Callable =>
2888 Set_Etype (N, Standard_Boolean);
2895 when Attribute_Caller => Caller : declare
2902 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2905 if not Is_Entry (Ent) then
2906 Error_Attr ("invalid entry name", N);
2910 Error_Attr ("invalid entry name", N);
2914 for J in reverse 0 .. Scope_Stack.Last loop
2915 S := Scope_Stack.Table (J).Entity;
2917 if S = Scope (Ent) then
2918 Error_Attr ("Caller must appear in matching accept or body", N);
2924 Set_Etype (N, RTE (RO_AT_Task_Id));
2931 when Attribute_Ceiling =>
2932 Check_Floating_Point_Type_1;
2933 Set_Etype (N, P_Base_Type);
2934 Resolve (E1, P_Base_Type);
2940 when Attribute_Class =>
2941 Check_Restriction (No_Dispatch, N);
2945 -- Applying Class to untagged incomplete type is obsolescent in Ada
2946 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
2947 -- this flag gets set by Find_Type in this situation.
2949 if Restriction_Check_Required (No_Obsolescent_Features)
2950 and then Ada_Version >= Ada_2005
2951 and then Ekind (P_Type) = E_Incomplete_Type
2954 DN : constant Node_Id := Declaration_Node (P_Type);
2956 if Nkind (DN) = N_Incomplete_Type_Declaration
2957 and then not Tagged_Present (DN)
2959 Check_Restriction (No_Obsolescent_Features, P);
2968 when Attribute_Code_Address =>
2971 if Nkind (P) = N_Attribute_Reference
2972 and then Nam_In (Attribute_Name (P), Name_Elab_Body, Name_Elab_Spec)
2976 elsif not Is_Entity_Name (P)
2977 or else (Ekind (Entity (P)) /= E_Function
2979 Ekind (Entity (P)) /= E_Procedure)
2981 Error_Attr ("invalid prefix for % attribute", P);
2982 Set_Address_Taken (Entity (P));
2984 -- Issue an error if the prefix denotes an eliminated subprogram
2987 Check_For_Eliminated_Subprogram (P, Entity (P));
2990 Set_Etype (N, RTE (RE_Address));
2992 ----------------------
2993 -- Compiler_Version --
2994 ----------------------
2996 when Attribute_Compiler_Version =>
2998 Check_Standard_Prefix;
2999 Rewrite (N, Make_String_Literal (Loc, "GNAT " & Gnat_Version_String));
3000 Analyze_And_Resolve (N, Standard_String);
3002 --------------------
3003 -- Component_Size --
3004 --------------------
3006 when Attribute_Component_Size =>
3008 Set_Etype (N, Universal_Integer);
3010 -- Note: unlike other array attributes, unconstrained arrays are OK
3012 if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then
3022 when Attribute_Compose =>
3023 Check_Floating_Point_Type_2;
3024 Set_Etype (N, P_Base_Type);
3025 Resolve (E1, P_Base_Type);
3026 Resolve (E2, Any_Integer);
3032 when Attribute_Constrained =>
3034 Set_Etype (N, Standard_Boolean);
3036 -- Case from RM J.4(2) of constrained applied to private type
3038 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
3039 Check_Restriction (No_Obsolescent_Features, P);
3041 if Warn_On_Obsolescent_Feature then
3043 ("constrained for private type is an " &
3044 "obsolescent feature (RM J.4)?j?", N);
3047 -- If we are within an instance, the attribute must be legal
3048 -- because it was valid in the generic unit. Ditto if this is
3049 -- an inlining of a function declared in an instance.
3052 or else In_Inlined_Body
3056 -- For sure OK if we have a real private type itself, but must
3057 -- be completed, cannot apply Constrained to incomplete type.
3059 elsif Is_Private_Type (Entity (P)) then
3061 -- Note: this is one of the Annex J features that does not
3062 -- generate a warning from -gnatwj, since in fact it seems
3063 -- very useful, and is used in the GNAT runtime.
3065 Check_Not_Incomplete_Type;
3069 -- Normal (non-obsolescent case) of application to object of
3070 -- a discriminated type.
3073 Check_Object_Reference (P);
3075 -- If N does not come from source, then we allow the
3076 -- the attribute prefix to be of a private type whose
3077 -- full type has discriminants. This occurs in cases
3078 -- involving expanded calls to stream attributes.
3080 if not Comes_From_Source (N) then
3081 P_Type := Underlying_Type (P_Type);
3084 -- Must have discriminants or be an access type designating
3085 -- a type with discriminants. If it is a classwide type it
3086 -- has unknown discriminants.
3088 if Has_Discriminants (P_Type)
3089 or else Has_Unknown_Discriminants (P_Type)
3091 (Is_Access_Type (P_Type)
3092 and then Has_Discriminants (Designated_Type (P_Type)))
3096 -- The rule given in 3.7.2 is part of static semantics, but the
3097 -- intent is clearly that it be treated as a legality rule, and
3098 -- rechecked in the visible part of an instance. Nevertheless
3099 -- the intent also seems to be it should legally apply to the
3100 -- actual of a formal with unknown discriminants, regardless of
3101 -- whether the actual has discriminants, in which case the value
3102 -- of the attribute is determined using the J.4 rules. This choice
3103 -- seems the most useful, and is compatible with existing tests.
3105 elsif In_Instance then
3108 -- Also allow an object of a generic type if extensions allowed
3109 -- and allow this for any type at all. (this may be obsolete ???)
3111 elsif (Is_Generic_Type (P_Type)
3112 or else Is_Generic_Actual_Type (P_Type))
3113 and then Extensions_Allowed
3119 -- Fall through if bad prefix
3122 ("prefix of % attribute must be object of discriminated type");
3128 when Attribute_Copy_Sign =>
3129 Check_Floating_Point_Type_2;
3130 Set_Etype (N, P_Base_Type);
3131 Resolve (E1, P_Base_Type);
3132 Resolve (E2, P_Base_Type);
3138 when Attribute_Count => Count :
3147 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
3150 if Ekind (Ent) /= E_Entry then
3151 Error_Attr ("invalid entry name", N);
3154 elsif Nkind (P) = N_Indexed_Component then
3155 if not Is_Entity_Name (Prefix (P))
3156 or else No (Entity (Prefix (P)))
3157 or else Ekind (Entity (Prefix (P))) /= E_Entry_Family
3159 if Nkind (Prefix (P)) = N_Selected_Component
3160 and then Present (Entity (Selector_Name (Prefix (P))))
3161 and then Ekind (Entity (Selector_Name (Prefix (P)))) =
3165 ("attribute % must apply to entry of current task", P);
3168 Error_Attr ("invalid entry family name", P);
3173 Ent := Entity (Prefix (P));
3176 elsif Nkind (P) = N_Selected_Component
3177 and then Present (Entity (Selector_Name (P)))
3178 and then Ekind (Entity (Selector_Name (P))) = E_Entry
3181 ("attribute % must apply to entry of current task", P);
3184 Error_Attr ("invalid entry name", N);
3188 for J in reverse 0 .. Scope_Stack.Last loop
3189 S := Scope_Stack.Table (J).Entity;
3191 if S = Scope (Ent) then
3192 if Nkind (P) = N_Expanded_Name then
3193 Tsk := Entity (Prefix (P));
3195 -- The prefix denotes either the task type, or else a
3196 -- single task whose task type is being analyzed.
3201 or else (not Is_Type (Tsk)
3202 and then Etype (Tsk) = S
3203 and then not (Comes_From_Source (S)))
3208 ("Attribute % must apply to entry of current task", N);
3214 elsif Ekind (Scope (Ent)) in Task_Kind
3216 not Ekind_In (S, E_Loop, E_Block, E_Entry, E_Entry_Family)
3218 Error_Attr ("Attribute % cannot appear in inner unit", N);
3220 elsif Ekind (Scope (Ent)) = E_Protected_Type
3221 and then not Has_Completion (Scope (Ent))
3223 Error_Attr ("attribute % can only be used inside body", N);
3227 if Is_Overloaded (P) then
3229 Index : Interp_Index;
3233 Get_First_Interp (P, Index, It);
3235 while Present (It.Nam) loop
3236 if It.Nam = Ent then
3239 -- Ada 2005 (AI-345): Do not consider primitive entry
3240 -- wrappers generated for task or protected types.
3242 elsif Ada_Version >= Ada_2005
3243 and then not Comes_From_Source (It.Nam)
3248 Error_Attr ("ambiguous entry name", N);
3251 Get_Next_Interp (Index, It);
3256 Set_Etype (N, Universal_Integer);
3259 -----------------------
3260 -- Default_Bit_Order --
3261 -----------------------
3263 when Attribute_Default_Bit_Order => Default_Bit_Order :
3265 Check_Standard_Prefix;
3267 if Bytes_Big_Endian then
3269 Make_Integer_Literal (Loc, False_Value));
3272 Make_Integer_Literal (Loc, True_Value));
3275 Set_Etype (N, Universal_Integer);
3276 Set_Is_Static_Expression (N);
3277 end Default_Bit_Order;
3283 when Attribute_Definite =>
3284 Legal_Formal_Attribute;
3290 when Attribute_Delta =>
3291 Check_Fixed_Point_Type_0;
3292 Set_Etype (N, Universal_Real);
3298 when Attribute_Denorm =>
3299 Check_Floating_Point_Type_0;
3300 Set_Etype (N, Standard_Boolean);
3302 ---------------------
3303 -- Descriptor_Size --
3304 ---------------------
3306 when Attribute_Descriptor_Size =>
3309 if not Is_Entity_Name (P)
3310 or else not Is_Type (Entity (P))
3312 Error_Attr_P ("prefix of attribute % must denote a type");
3315 Set_Etype (N, Universal_Integer);
3321 when Attribute_Digits =>
3325 if not Is_Floating_Point_Type (P_Type)
3326 and then not Is_Decimal_Fixed_Point_Type (P_Type)
3329 ("prefix of % attribute must be float or decimal type");
3332 Set_Etype (N, Universal_Integer);
3338 -- Also handles processing for Elab_Spec and Elab_Subp_Body
3340 when Attribute_Elab_Body |
3341 Attribute_Elab_Spec |
3342 Attribute_Elab_Subp_Body =>
3345 Check_Unit_Name (P);
3346 Set_Etype (N, Standard_Void_Type);
3348 -- We have to manually call the expander in this case to get
3349 -- the necessary expansion (normally attributes that return
3350 -- entities are not expanded).
3358 -- Shares processing with Elab_Body
3364 when Attribute_Elaborated =>
3366 Check_Unit_Name (P);
3367 Set_Etype (N, Standard_Boolean);
3373 when Attribute_Emax =>
3374 Check_Floating_Point_Type_0;
3375 Set_Etype (N, Universal_Integer);
3381 when Attribute_Enabled =>
3382 Check_Either_E0_Or_E1;
3384 if Present (E1) then
3385 if not Is_Entity_Name (E1) or else No (Entity (E1)) then
3386 Error_Msg_N ("entity name expected for Enabled attribute", E1);
3391 if Nkind (P) /= N_Identifier then
3392 Error_Msg_N ("identifier expected (check name)", P);
3393 elsif Get_Check_Id (Chars (P)) = No_Check_Id then
3394 Error_Msg_N ("& is not a recognized check name", P);
3397 Set_Etype (N, Standard_Boolean);
3403 when Attribute_Enum_Rep => Enum_Rep : declare
3405 if Present (E1) then
3407 Check_Discrete_Type;
3408 Resolve (E1, P_Base_Type);
3411 if not Is_Entity_Name (P)
3412 or else (not Is_Object (Entity (P))
3414 Ekind (Entity (P)) /= E_Enumeration_Literal)
3417 ("prefix of % attribute must be " &
3418 "discrete type/object or enum literal");
3422 Set_Etype (N, Universal_Integer);
3429 when Attribute_Enum_Val => Enum_Val : begin
3433 if not Is_Enumeration_Type (P_Type) then
3434 Error_Attr_P ("prefix of % attribute must be enumeration type");
3437 -- If the enumeration type has a standard representation, the effect
3438 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3440 if not Has_Non_Standard_Rep (P_Base_Type) then
3442 Make_Attribute_Reference (Loc,
3443 Prefix => Relocate_Node (Prefix (N)),
3444 Attribute_Name => Name_Val,
3445 Expressions => New_List (Relocate_Node (E1))));
3446 Analyze_And_Resolve (N, P_Base_Type);
3448 -- Non-standard representation case (enumeration with holes)
3452 Resolve (E1, Any_Integer);
3453 Set_Etype (N, P_Base_Type);
3461 when Attribute_Epsilon =>
3462 Check_Floating_Point_Type_0;
3463 Set_Etype (N, Universal_Real);
3469 when Attribute_Exponent =>
3470 Check_Floating_Point_Type_1;
3471 Set_Etype (N, Universal_Integer);
3472 Resolve (E1, P_Base_Type);
3478 when Attribute_External_Tag =>
3482 Set_Etype (N, Standard_String);
3484 if not Is_Tagged_Type (P_Type) then
3485 Error_Attr_P ("prefix of % attribute must be tagged");
3492 when Attribute_Fast_Math =>
3493 Check_Standard_Prefix;
3494 Rewrite (N, New_Occurrence_Of (Boolean_Literals (Fast_Math), Loc));
3500 when Attribute_First =>
3501 Check_Array_Or_Scalar_Type;
3502 Bad_Attribute_For_Predicate;
3508 when Attribute_First_Bit =>
3510 Set_Etype (N, Universal_Integer);
3516 when Attribute_First_Valid =>
3517 Check_First_Last_Valid;
3518 Set_Etype (N, P_Type);
3524 when Attribute_Fixed_Value =>
3526 Check_Fixed_Point_Type;
3527 Resolve (E1, Any_Integer);
3528 Set_Etype (N, P_Base_Type);
3534 when Attribute_Floor =>
3535 Check_Floating_Point_Type_1;
3536 Set_Etype (N, P_Base_Type);
3537 Resolve (E1, P_Base_Type);
3543 when Attribute_Fore =>
3544 Check_Fixed_Point_Type_0;
3545 Set_Etype (N, Universal_Integer);
3551 when Attribute_Fraction =>
3552 Check_Floating_Point_Type_1;
3553 Set_Etype (N, P_Base_Type);
3554 Resolve (E1, P_Base_Type);
3560 when Attribute_From_Any =>
3562 Check_PolyORB_Attribute;
3563 Set_Etype (N, P_Base_Type);
3565 -----------------------
3566 -- Has_Access_Values --
3567 -----------------------
3569 when Attribute_Has_Access_Values =>
3572 Set_Etype (N, Standard_Boolean);
3574 ----------------------
3575 -- Has_Same_Storage --
3576 ----------------------
3578 when Attribute_Has_Same_Storage =>
3579 Check_Ada_2012_Attribute;
3582 -- The arguments must be objects of any type
3584 Analyze_And_Resolve (P);
3585 Analyze_And_Resolve (E1);
3586 Check_Object_Reference (P);
3587 Check_Object_Reference (E1);
3588 Set_Etype (N, Standard_Boolean);
3590 -----------------------
3591 -- Has_Tagged_Values --
3592 -----------------------
3594 when Attribute_Has_Tagged_Values =>
3597 Set_Etype (N, Standard_Boolean);
3599 -----------------------
3600 -- Has_Discriminants --
3601 -----------------------
3603 when Attribute_Has_Discriminants =>
3604 Legal_Formal_Attribute;
3610 when Attribute_Identity =>
3614 if Etype (P) = Standard_Exception_Type then
3615 Set_Etype (N, RTE (RE_Exception_Id));
3617 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to
3618 -- task interface class-wide types.
3620 elsif Is_Task_Type (Etype (P))
3621 or else (Is_Access_Type (Etype (P))
3622 and then Is_Task_Type (Designated_Type (Etype (P))))
3623 or else (Ada_Version >= Ada_2005
3624 and then Ekind (Etype (P)) = E_Class_Wide_Type
3625 and then Is_Interface (Etype (P))
3626 and then Is_Task_Interface (Etype (P)))
3629 Set_Etype (N, RTE (RO_AT_Task_Id));
3632 if Ada_Version >= Ada_2005 then
3634 ("prefix of % attribute must be an exception, a " &
3635 "task or a task interface class-wide object");
3638 ("prefix of % attribute must be a task or an exception");
3646 when Attribute_Image => Image :
3648 Check_SPARK_Restriction_On_Attribute;
3650 Set_Etype (N, Standard_String);
3652 if Is_Real_Type (P_Type) then
3653 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3654 Error_Msg_Name_1 := Aname;
3656 ("(Ada 83) % attribute not allowed for real types", N);
3660 if Is_Enumeration_Type (P_Type) then
3661 Check_Restriction (No_Enumeration_Maps, N);
3665 Resolve (E1, P_Base_Type);
3667 Validate_Non_Static_Attribute_Function_Call;
3669 -- Check restriction No_Fixed_IO. Note the check of Comes_From_Source
3670 -- to avoid giving a duplicate message for Img expanded into Image.
3672 if Restriction_Check_Required (No_Fixed_IO)
3673 and then Comes_From_Source (N)
3674 and then Is_Fixed_Point_Type (P_Type)
3676 Check_Restriction (No_Fixed_IO, P);
3684 when Attribute_Img => Img :
3687 Set_Etype (N, Standard_String);
3689 if not Is_Scalar_Type (P_Type)
3690 or else (Is_Entity_Name (P) and then Is_Type (Entity (P)))
3693 ("prefix of % attribute must be scalar object name");
3698 -- Check restriction No_Fixed_IO
3700 if Restriction_Check_Required (No_Fixed_IO)
3701 and then Is_Fixed_Point_Type (P_Type)
3703 Check_Restriction (No_Fixed_IO, P);
3711 when Attribute_Input =>
3713 Check_Stream_Attribute (TSS_Stream_Input);
3714 Set_Etype (N, P_Base_Type);
3720 when Attribute_Integer_Value =>
3723 Resolve (E1, Any_Fixed);
3725 -- Signal an error if argument type is not a specific fixed-point
3726 -- subtype. An error has been signalled already if the argument
3727 -- was not of a fixed-point type.
3729 if Etype (E1) = Any_Fixed and then not Error_Posted (E1) then
3730 Error_Attr ("argument of % must be of a fixed-point type", E1);
3733 Set_Etype (N, P_Base_Type);
3739 when Attribute_Invalid_Value =>
3742 Set_Etype (N, P_Base_Type);
3743 Invalid_Value_Used := True;
3749 when Attribute_Large =>
3752 Set_Etype (N, Universal_Real);
3758 when Attribute_Last =>
3759 Check_Array_Or_Scalar_Type;
3760 Bad_Attribute_For_Predicate;
3766 when Attribute_Last_Bit =>
3768 Set_Etype (N, Universal_Integer);
3774 when Attribute_Last_Valid =>
3775 Check_First_Last_Valid;
3776 Set_Etype (N, P_Type);
3782 when Attribute_Leading_Part =>
3783 Check_Floating_Point_Type_2;
3784 Set_Etype (N, P_Base_Type);
3785 Resolve (E1, P_Base_Type);
3786 Resolve (E2, Any_Integer);
3792 when Attribute_Length =>
3794 Set_Etype (N, Universal_Integer);
3800 when Attribute_Library_Level =>
3803 if not Is_Entity_Name (P) then
3804 Error_Attr_P ("prefix of % attribute must be an entity name");
3807 if not Inside_A_Generic then
3808 Set_Boolean_Result (N,
3809 Is_Library_Level_Entity (Entity (P)));
3812 Set_Etype (N, Standard_Boolean);
3818 when Attribute_Lock_Free =>
3820 Set_Etype (N, Standard_Boolean);
3822 if not Is_Protected_Type (P_Type) then
3824 ("prefix of % attribute must be a protected object");
3831 when Attribute_Loop_Entry => Loop_Entry : declare
3832 procedure Check_References_In_Prefix (Loop_Id : Entity_Id);
3833 -- Inspect the prefix for any uses of entities declared within the
3834 -- related loop. Loop_Id denotes the loop identifier.
3836 --------------------------------
3837 -- Check_References_In_Prefix --
3838 --------------------------------
3840 procedure Check_References_In_Prefix (Loop_Id : Entity_Id) is
3841 Loop_Decl : constant Node_Id := Label_Construct (Parent (Loop_Id));
3843 function Check_Reference (Nod : Node_Id) return Traverse_Result;
3844 -- Determine whether a reference mentions an entity declared
3845 -- within the related loop.
3847 function Declared_Within (Nod : Node_Id) return Boolean;
3848 -- Determine whether Nod appears in the subtree of Loop_Decl
3850 ---------------------
3851 -- Check_Reference --
3852 ---------------------
3854 function Check_Reference (Nod : Node_Id) return Traverse_Result is
3856 if Nkind (Nod) = N_Identifier
3857 and then Present (Entity (Nod))
3858 and then Declared_Within (Declaration_Node (Entity (Nod)))
3861 ("prefix of attribute % cannot reference local entities",
3867 end Check_Reference;
3869 procedure Check_References is new Traverse_Proc (Check_Reference);
3871 ---------------------
3872 -- Declared_Within --
3873 ---------------------
3875 function Declared_Within (Nod : Node_Id) return Boolean is
3880 while Present (Stmt) loop
3881 if Stmt = Loop_Decl then
3884 -- Prevent the search from going too far
3886 elsif Is_Body_Or_Package_Declaration (Stmt) then
3890 Stmt := Parent (Stmt);
3894 end Declared_Within;
3896 -- Start of processing for Check_Prefix_For_Local_References
3899 Check_References (P);
3900 end Check_References_In_Prefix;
3904 Context : constant Node_Id := Parent (N);
3906 Enclosing_Loop : Node_Id;
3907 Loop_Id : Entity_Id := Empty;
3910 Enclosing_Pragma : Node_Id := Empty;
3912 -- Start of processing for Loop_Entry
3917 -- Set the type of the attribute now to ensure the successfull
3918 -- continuation of analysis even if the attribute is misplaced.
3920 Set_Etype (Attr, P_Type);
3922 -- Attribute 'Loop_Entry may appear in several flavors:
3924 -- * Prefix'Loop_Entry - in this form, the attribute applies to the
3925 -- nearest enclosing loop.
3927 -- * Prefix'Loop_Entry (Expr) - depending on what Expr denotes, the
3928 -- attribute may be related to a loop denoted by label Expr or
3929 -- the prefix may denote an array object and Expr may act as an
3930 -- indexed component.
3932 -- * Prefix'Loop_Entry (Expr1, ..., ExprN) - the attribute applies
3933 -- to the nearest enclosing loop, all expressions are part of
3934 -- an indexed component.
3936 -- * Prefix'Loop_Entry (Expr) (...) (...) - depending on what Expr
3937 -- denotes, the attribute may be related to a loop denoted by
3938 -- label Expr or the prefix may denote a multidimensional array
3939 -- array object and Expr along with the rest of the expressions
3940 -- may act as indexed components.
3942 -- Regardless of variations, the attribute reference does not have an
3943 -- expression list. Instead, all available expressions are stored as
3944 -- indexed components.
3946 -- When the attribute is part of an indexed component, find the first
3947 -- expression as it will determine the semantics of 'Loop_Entry.
3949 if Nkind (Context) = N_Indexed_Component then
3950 E1 := First (Expressions (Context));
3953 -- The attribute reference appears in the following form:
3955 -- Prefix'Loop_Entry (Exp1, Expr2, ..., ExprN) [(...)]
3957 -- In this case, the loop name is omitted and no rewriting is
3960 if Present (E2) then
3963 -- The form of the attribute is:
3965 -- Prefix'Loop_Entry (Expr) [(...)]
3967 -- If Expr denotes a loop entry, the whole attribute and indexed
3968 -- component will have to be rewritten to reflect this relation.
3971 pragma Assert (Present (E1));
3973 -- Do not expand the expression as it may have side effects.
3974 -- Simply preanalyze to determine whether it is a loop name or
3977 Preanalyze_And_Resolve (E1);
3979 if Is_Entity_Name (E1)
3980 and then Present (Entity (E1))
3981 and then Ekind (Entity (E1)) = E_Loop
3983 Loop_Id := Entity (E1);
3985 -- Transform the attribute and enclosing indexed component
3987 Set_Expressions (N, Expressions (Context));
3988 Rewrite (Context, N);
3989 Set_Etype (Context, P_Type);
3996 -- The prefix must denote an object
3998 if not Is_Object_Reference (P) then
3999 Error_Attr_P ("prefix of attribute % must denote an object");
4002 -- The prefix cannot be of a limited type because the expansion of
4003 -- Loop_Entry must create a constant initialized by the evaluated
4006 if Is_Limited_View (Etype (P)) then
4007 Error_Attr_P ("prefix of attribute % cannot be limited");
4010 -- Climb the parent chain to verify the location of the attribute and
4011 -- find the enclosing loop.
4014 while Present (Stmt) loop
4016 -- Locate the corresponding enclosing pragma. Note that in the
4017 -- case of Assert[And_Cut] and Assume, we have already checked
4018 -- that the pragma appears in an appropriate loop location.
4020 if Nkind (Original_Node (Stmt)) = N_Pragma
4021 and then Nam_In (Pragma_Name (Original_Node (Stmt)),
4022 Name_Loop_Invariant,
4025 Name_Assert_And_Cut,
4028 Enclosing_Pragma := Original_Node (Stmt);
4030 -- Locate the enclosing loop (if any). Note that Ada 2012 array
4031 -- iteration may be expanded into several nested loops, we are
4032 -- interested in the outermost one which has the loop identifier.
4034 elsif Nkind (Stmt) = N_Loop_Statement
4035 and then Present (Identifier (Stmt))
4037 Enclosing_Loop := Stmt;
4039 -- The original attribute reference may lack a loop name. Use
4040 -- the name of the enclosing loop because it is the related
4043 if No (Loop_Id) then
4044 Loop_Id := Entity (Identifier (Enclosing_Loop));
4049 -- Prevent the search from going too far
4051 elsif Is_Body_Or_Package_Declaration (Stmt) then
4055 Stmt := Parent (Stmt);
4058 -- Loop_Entry must appear within a Loop_Assertion pragma (Assert,
4059 -- Assert_And_Cut, Assume count as loop assertion pragmas for this
4060 -- purpose if they appear in an appropriate location in a loop,
4061 -- which was already checked by the top level pragma circuit).
4063 if No (Enclosing_Pragma) then
4064 Error_Attr ("attribute% must appear within appropriate pragma", N);
4067 -- A Loop_Entry that applies to a given loop statement must not
4068 -- appear within a body of accept statement, if this construct is
4069 -- itself enclosed by the given loop statement.
4071 for Index in reverse 0 .. Scope_Stack.Last loop
4072 Scop := Scope_Stack.Table (Index).Entity;
4074 if Ekind (Scop) = E_Loop and then Scop = Loop_Id then
4076 elsif Ekind_In (Scop, E_Block, E_Loop, E_Return_Statement) then
4080 ("attribute % cannot appear in body or accept statement", N);
4085 -- The prefix cannot mention entities declared within the related
4086 -- loop because they will not be visible once the prefix is moved
4087 -- outside the loop.
4089 Check_References_In_Prefix (Loop_Id);
4091 -- The prefix must denote a static entity if the pragma does not
4092 -- apply to the innermost enclosing loop statement, or if it appears
4093 -- within a potentially unevaluated epxression.
4095 if Is_Entity_Name (P)
4096 or else Nkind (Parent (P)) = N_Object_Renaming_Declaration
4100 elsif Present (Enclosing_Loop)
4101 and then Entity (Identifier (Enclosing_Loop)) /= Loop_Id
4104 ("prefix of attribute % that applies to "
4105 & "outer loop must denote an entity");
4107 elsif Is_Potentially_Unevaluated (P) then
4109 ("prefix of attribute % that is potentially "
4110 & "unevaluated must denote an entity");
4113 -- Finally, if the Loop_Entry attribute appears within a pragma
4114 -- that is ignored, we replace P'Loop_Entity by P to avoid useless
4115 -- generation of the loop entity variable. Note that in this case
4116 -- the expression won't be executed anyway, and this substitution
4117 -- keeps types happy!
4119 -- We should really do this in the expander, but it's easier here
4121 if Is_Ignored (Enclosing_Pragma) then
4122 Rewrite (N, Relocate_Node (P));
4130 when Attribute_Machine =>
4131 Check_Floating_Point_Type_1;
4132 Set_Etype (N, P_Base_Type);
4133 Resolve (E1, P_Base_Type);
4139 when Attribute_Machine_Emax =>
4140 Check_Floating_Point_Type_0;
4141 Set_Etype (N, Universal_Integer);
4147 when Attribute_Machine_Emin =>
4148 Check_Floating_Point_Type_0;
4149 Set_Etype (N, Universal_Integer);
4151 ----------------------
4152 -- Machine_Mantissa --
4153 ----------------------
4155 when Attribute_Machine_Mantissa =>
4156 Check_Floating_Point_Type_0;
4157 Set_Etype (N, Universal_Integer);
4159 -----------------------
4160 -- Machine_Overflows --
4161 -----------------------
4163 when Attribute_Machine_Overflows =>
4166 Set_Etype (N, Standard_Boolean);
4172 when Attribute_Machine_Radix =>
4175 Set_Etype (N, Universal_Integer);
4177 ----------------------
4178 -- Machine_Rounding --
4179 ----------------------
4181 when Attribute_Machine_Rounding =>
4182 Check_Floating_Point_Type_1;
4183 Set_Etype (N, P_Base_Type);
4184 Resolve (E1, P_Base_Type);
4186 --------------------
4187 -- Machine_Rounds --
4188 --------------------
4190 when Attribute_Machine_Rounds =>
4193 Set_Etype (N, Standard_Boolean);
4199 when Attribute_Machine_Size =>
4202 Check_Not_Incomplete_Type;
4203 Set_Etype (N, Universal_Integer);
4209 when Attribute_Mantissa =>
4212 Set_Etype (N, Universal_Integer);
4218 when Attribute_Max =>
4221 ----------------------------------
4222 -- Max_Alignment_For_Allocation --
4223 ----------------------------------
4225 when Attribute_Max_Size_In_Storage_Elements =>
4226 Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements;
4228 ----------------------------------
4229 -- Max_Size_In_Storage_Elements --
4230 ----------------------------------
4232 when Attribute_Max_Alignment_For_Allocation =>
4233 Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements;
4235 -----------------------
4236 -- Maximum_Alignment --
4237 -----------------------
4239 when Attribute_Maximum_Alignment =>
4240 Standard_Attribute (Ttypes.Maximum_Alignment);
4242 --------------------
4243 -- Mechanism_Code --
4244 --------------------
4246 when Attribute_Mechanism_Code =>
4247 if not Is_Entity_Name (P)
4248 or else not Is_Subprogram (Entity (P))
4250 Error_Attr_P ("prefix of % attribute must be subprogram");
4253 Check_Either_E0_Or_E1;
4255 if Present (E1) then
4256 Resolve (E1, Any_Integer);
4257 Set_Etype (E1, Standard_Integer);
4259 if not Is_Static_Expression (E1) then
4260 Flag_Non_Static_Expr
4261 ("expression for parameter number must be static!", E1);
4264 elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P))
4265 or else UI_To_Int (Intval (E1)) < 0
4267 Error_Attr ("invalid parameter number for % attribute", E1);
4271 Set_Etype (N, Universal_Integer);
4277 when Attribute_Min =>
4284 when Attribute_Mod =>
4286 -- Note: this attribute is only allowed in Ada 2005 mode, but
4287 -- we do not need to test that here, since Mod is only recognized
4288 -- as an attribute name in Ada 2005 mode during the parse.
4291 Check_Modular_Integer_Type;
4292 Resolve (E1, Any_Integer);
4293 Set_Etype (N, P_Base_Type);
4299 when Attribute_Model =>
4300 Check_Floating_Point_Type_1;
4301 Set_Etype (N, P_Base_Type);
4302 Resolve (E1, P_Base_Type);
4308 when Attribute_Model_Emin =>
4309 Check_Floating_Point_Type_0;
4310 Set_Etype (N, Universal_Integer);
4316 when Attribute_Model_Epsilon =>
4317 Check_Floating_Point_Type_0;
4318 Set_Etype (N, Universal_Real);
4320 --------------------
4321 -- Model_Mantissa --
4322 --------------------
4324 when Attribute_Model_Mantissa =>
4325 Check_Floating_Point_Type_0;
4326 Set_Etype (N, Universal_Integer);
4332 when Attribute_Model_Small =>
4333 Check_Floating_Point_Type_0;
4334 Set_Etype (N, Universal_Real);
4340 when Attribute_Modulus =>
4342 Check_Modular_Integer_Type;
4343 Set_Etype (N, Universal_Integer);
4345 --------------------
4346 -- Null_Parameter --
4347 --------------------
4349 when Attribute_Null_Parameter => Null_Parameter : declare
4350 Parnt : constant Node_Id := Parent (N);
4351 GParnt : constant Node_Id := Parent (Parnt);
4353 procedure Bad_Null_Parameter (Msg : String);
4354 -- Used if bad Null parameter attribute node is found. Issues
4355 -- given error message, and also sets the type to Any_Type to
4356 -- avoid blowups later on from dealing with a junk node.
4358 procedure Must_Be_Imported (Proc_Ent : Entity_Id);
4359 -- Called to check that Proc_Ent is imported subprogram
4361 ------------------------
4362 -- Bad_Null_Parameter --
4363 ------------------------
4365 procedure Bad_Null_Parameter (Msg : String) is
4367 Error_Msg_N (Msg, N);
4368 Set_Etype (N, Any_Type);
4369 end Bad_Null_Parameter;
4371 ----------------------
4372 -- Must_Be_Imported --
4373 ----------------------
4375 procedure Must_Be_Imported (Proc_Ent : Entity_Id) is
4376 Pent : constant Entity_Id := Ultimate_Alias (Proc_Ent);
4379 -- Ignore check if procedure not frozen yet (we will get
4380 -- another chance when the default parameter is reanalyzed)
4382 if not Is_Frozen (Pent) then
4385 elsif not Is_Imported (Pent) then
4387 ("Null_Parameter can only be used with imported subprogram");
4392 end Must_Be_Imported;
4394 -- Start of processing for Null_Parameter
4399 Set_Etype (N, P_Type);
4401 -- Case of attribute used as default expression
4403 if Nkind (Parnt) = N_Parameter_Specification then
4404 Must_Be_Imported (Defining_Entity (GParnt));
4406 -- Case of attribute used as actual for subprogram (positional)
4408 elsif Nkind (Parnt) in N_Subprogram_Call
4409 and then Is_Entity_Name (Name (Parnt))
4411 Must_Be_Imported (Entity (Name (Parnt)));
4413 -- Case of attribute used as actual for subprogram (named)
4415 elsif Nkind (Parnt) = N_Parameter_Association
4416 and then Nkind (GParnt) in N_Subprogram_Call
4417 and then Is_Entity_Name (Name (GParnt))
4419 Must_Be_Imported (Entity (Name (GParnt)));
4421 -- Not an allowed case
4425 ("Null_Parameter must be actual or default parameter");
4433 when Attribute_Object_Size =>
4436 Check_Not_Incomplete_Type;
4437 Set_Etype (N, Universal_Integer);
4443 when Attribute_Old => Old : declare
4444 procedure Check_References_In_Prefix (Subp_Id : Entity_Id);
4445 -- Inspect the contents of the prefix and detect illegal uses of a
4446 -- nested 'Old, attribute 'Result or a use of an entity declared in
4447 -- the related postcondition expression. Subp_Id is the subprogram to
4448 -- which the related postcondition applies.
4450 procedure Check_Use_In_Contract_Cases (Prag : Node_Id);
4451 -- Perform various semantic checks related to the placement of the
4452 -- attribute in pragma Contract_Cases.
4454 procedure Check_Use_In_Test_Case (Prag : Node_Id);
4455 -- Perform various semantic checks related to the placement of the
4456 -- attribute in pragma Contract_Cases.
4458 --------------------------------
4459 -- Check_References_In_Prefix --
4460 --------------------------------
4462 procedure Check_References_In_Prefix (Subp_Id : Entity_Id) is
4463 function Check_Reference (Nod : Node_Id) return Traverse_Result;
4464 -- Detect attribute 'Old, attribute 'Result of a use of an entity
4465 -- and perform the appropriate semantic check.
4467 ---------------------
4468 -- Check_Reference --
4469 ---------------------
4471 function Check_Reference (Nod : Node_Id) return Traverse_Result is
4473 -- Attributes 'Old and 'Result cannot appear in the prefix of
4474 -- another attribute 'Old.
4476 if Nkind (Nod) = N_Attribute_Reference
4477 and then Nam_In (Attribute_Name (Nod), Name_Old,
4480 Error_Msg_Name_1 := Attribute_Name (Nod);
4481 Error_Msg_Name_2 := Name_Old;
4483 ("attribute % cannot appear in the prefix of attribute %",
4487 -- Entities mentioned within the prefix of attribute 'Old must
4488 -- be global to the related postcondition. If this is not the
4489 -- case, then the scope of the local entity is nested within
4490 -- that of the subprogram.
4492 elsif Nkind (Nod) = N_Identifier
4493 and then Present (Entity (Nod))
4494 and then Scope_Within (Scope (Entity (Nod)), Subp_Id)
4497 ("prefix of attribute % cannot reference local entities",
4503 end Check_Reference;
4505 procedure Check_References is new Traverse_Proc (Check_Reference);
4507 -- Start of processing for Check_References_In_Prefix
4510 Check_References (P);
4511 end Check_References_In_Prefix;
4513 ---------------------------------
4514 -- Check_Use_In_Contract_Cases --
4515 ---------------------------------
4517 procedure Check_Use_In_Contract_Cases (Prag : Node_Id) is
4518 Cases : constant Node_Id :=
4520 (First (Pragma_Argument_Associations (Prag)));
4524 -- Climb the parent chain to reach the top of the expression where
4525 -- attribute 'Old resides.
4528 while Parent (Parent (Expr)) /= Cases loop
4529 Expr := Parent (Expr);
4532 -- Ensure that the obtained expression is the consequence of a
4533 -- contract case as this is the only postcondition-like part of
4536 if Expr = Expression (Parent (Expr)) then
4538 -- Warn that a potentially unevaluated prefix is always
4539 -- evaluated when the corresponding consequence is selected.
4541 if Is_Potentially_Unevaluated (P) then
4542 Error_Msg_Name_1 := Aname;
4544 ("??prefix of attribute % is always evaluated when "
4545 & "related consequence is selected", P);
4548 -- Attribute 'Old appears in the condition of a contract case.
4549 -- Emit an error since this is not a postcondition-like context.
4550 -- (SPARK RM 6.1.3(2))
4554 ("attribute % cannot appear in the condition "
4555 & "of a contract case", P);
4557 end Check_Use_In_Contract_Cases;
4559 ----------------------------
4560 -- Check_Use_In_Test_Case --
4561 ----------------------------
4563 procedure Check_Use_In_Test_Case (Prag : Node_Id) is
4564 Ensures : constant Node_Id := Get_Ensures_From_CTC_Pragma (Prag);
4568 -- Climb the parent chain to reach the top of the Ensures part of
4569 -- pragma Test_Case.
4572 while Expr /= Prag loop
4573 if Expr = Ensures then
4577 Expr := Parent (Expr);
4580 -- If we get there, then attribute 'Old appears in the requires
4581 -- expression of pragma Test_Case which is not a postcondition-
4585 ("attribute % cannot appear in the requires expression of a "
4587 end Check_Use_In_Test_Case;
4592 -- The enclosing scope, excluding loops for quantified expressions.
4593 -- During analysis, it is the postcondition subprogram. During
4594 -- pre-analysis, it is the scope of the subprogram declaration.
4597 -- During pre-analysis, Prag is the enclosing pragma node if any
4599 -- Start of processing for Old
4604 -- Find enclosing scopes, excluding loops
4606 CS := Current_Scope;
4607 while Ekind (CS) = E_Loop loop
4611 -- A Contract_Cases, Postcondition or Test_Case pragma is in the
4612 -- process of being preanalyzed. Perform the semantic checks now
4613 -- before the pragma is relocated and/or expanded.
4615 if In_Spec_Expression then
4617 while Present (Prag)
4618 and then not Nkind_In (Prag, N_Aspect_Specification,
4619 N_Function_Specification,
4621 N_Procedure_Specification,
4624 Prag := Parent (Prag);
4627 -- In ASIS mode, the aspect itself is analyzed, in addition to the
4628 -- corresponding pragma. Do not issue errors when analyzing the
4631 if Nkind (Prag) = N_Aspect_Specification then
4634 -- In all other cases the related context must be a pragma
4636 elsif Nkind (Prag) /= N_Pragma then
4637 Error_Attr ("% attribute can only appear in postcondition", P);
4639 -- Verify the placement of the attribute with respect to the
4643 case Get_Pragma_Id (Prag) is
4644 when Pragma_Contract_Cases =>
4645 Check_Use_In_Contract_Cases (Prag);
4647 when Pragma_Postcondition | Pragma_Refined_Post =>
4650 when Pragma_Test_Case =>
4651 Check_Use_In_Test_Case (Prag);
4655 ("% attribute can only appear in postcondition", P);
4659 -- Check the legality of attribute 'Old when it appears inside pragma
4660 -- Refined_Post. These specialized checks are required only when code
4661 -- generation is disabled. In the general case pragma Refined_Post is
4662 -- transformed into pragma Check by Process_PPCs which in turn is
4663 -- relocated to procedure _Postconditions. From then on the legality
4664 -- of 'Old is determined as usual.
4666 elsif not Expander_Active and then In_Refined_Post then
4667 Preanalyze_And_Resolve (P);
4668 Check_References_In_Prefix (CS);
4669 P_Type := Etype (P);
4670 Set_Etype (N, P_Type);
4672 if Is_Limited_Type (P_Type) then
4673 Error_Attr ("attribute % cannot apply to limited objects", P);
4676 if Is_Entity_Name (P)
4677 and then Is_Constant_Object (Entity (P))
4680 ("??attribute Old applied to constant has no effect", P);
4685 -- Body case, where we must be inside a generated _Postconditions
4686 -- procedure, or else the attribute use is definitely misplaced. The
4687 -- postcondition itself may have generated transient scopes, and is
4688 -- not necessarily the current one.
4691 while Present (CS) and then CS /= Standard_Standard loop
4692 if Chars (CS) = Name_uPostconditions then
4699 if Chars (CS) /= Name_uPostconditions then
4700 Error_Attr ("% attribute can only appear in postcondition", P);
4704 -- If the attribute reference is generated for a Requires clause,
4705 -- then no expressions follow. Otherwise it is a primary, in which
4706 -- case, if expressions follow, the attribute reference must be an
4707 -- indexable object, so rewrite the node accordingly.
4709 if Present (E1) then
4711 Make_Indexed_Component (Loc,
4713 Make_Attribute_Reference (Loc,
4714 Prefix => Relocate_Node (Prefix (N)),
4715 Attribute_Name => Name_Old),
4716 Expressions => Expressions (N)));
4724 -- Prefix has not been analyzed yet, and its full analysis will take
4725 -- place during expansion (see below).
4727 Preanalyze_And_Resolve (P);
4728 Check_References_In_Prefix (CS);
4729 P_Type := Etype (P);
4730 Set_Etype (N, P_Type);
4732 if Is_Limited_Type (P_Type) then
4733 Error_Attr ("attribute % cannot apply to limited objects", P);
4736 if Is_Entity_Name (P)
4737 and then Is_Constant_Object (Entity (P))
4740 ("??attribute Old applied to constant has no effect", P);
4743 -- Check that the prefix of 'Old is an entity, when it appears in
4744 -- a postcondition and may be potentially unevaluated (6.1.1 (27/3)).
4747 and then Get_Pragma_Id (Prag) = Pragma_Postcondition
4748 and then Is_Potentially_Unevaluated (N)
4749 and then not Is_Entity_Name (P)
4752 ("prefix of attribute % that is potentially unevaluated must "
4753 & "denote an entity");
4756 -- The attribute appears within a pre/postcondition, but refers to
4757 -- an entity in the enclosing subprogram. If it is a component of
4758 -- a formal its expansion might generate actual subtypes that may
4759 -- be referenced in an inner context, and which must be elaborated
4760 -- within the subprogram itself. If the prefix includes a function
4761 -- call it may involve finalization actions that should only be
4762 -- inserted when the attribute has been rewritten as a declarations.
4763 -- As a result, if the prefix is not a simple name we create
4764 -- a declaration for it now, and insert it at the start of the
4765 -- enclosing subprogram. This is properly an expansion activity
4766 -- but it has to be performed now to prevent out-of-order issues.
4768 -- This expansion is both harmful and not needed in SPARK mode, since
4769 -- the formal verification backend relies on the types of nodes
4770 -- (hence is not robust w.r.t. a change to base type here), and does
4771 -- not suffer from the out-of-order issue described above. Thus, this
4772 -- expansion is skipped in SPARK mode.
4774 if not Is_Entity_Name (P) and then not GNATprove_Mode then
4775 P_Type := Base_Type (P_Type);
4776 Set_Etype (N, P_Type);
4777 Set_Etype (P, P_Type);
4778 Analyze_Dimension (N);
4783 ----------------------
4784 -- Overlaps_Storage --
4785 ----------------------
4787 when Attribute_Overlaps_Storage =>
4790 -- Both arguments must be objects of any type
4792 Analyze_And_Resolve (P);
4793 Analyze_And_Resolve (E1);
4794 Check_Object_Reference (P);
4795 Check_Object_Reference (E1);
4796 Set_Etype (N, Standard_Boolean);
4802 when Attribute_Output =>
4804 Check_Stream_Attribute (TSS_Stream_Output);
4805 Set_Etype (N, Standard_Void_Type);
4806 Resolve (N, Standard_Void_Type);
4812 when Attribute_Partition_ID => Partition_Id :
4816 if P_Type /= Any_Type then
4817 if not Is_Library_Level_Entity (Entity (P)) then
4819 ("prefix of % attribute must be library-level entity");
4821 -- The defining entity of prefix should not be declared inside a
4822 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
4824 elsif Is_Entity_Name (P)
4825 and then Is_Pure (Entity (P))
4827 Error_Attr_P ("prefix of% attribute must not be declared pure");
4831 Set_Etype (N, Universal_Integer);
4834 -------------------------
4835 -- Passed_By_Reference --
4836 -------------------------
4838 when Attribute_Passed_By_Reference =>
4841 Set_Etype (N, Standard_Boolean);
4847 when Attribute_Pool_Address =>
4849 Set_Etype (N, RTE (RE_Address));
4855 when Attribute_Pos =>
4856 Check_Discrete_Type;
4859 if Is_Boolean_Type (P_Type) then
4860 Error_Msg_Name_1 := Aname;
4861 Error_Msg_Name_2 := Chars (P_Type);
4862 Check_SPARK_Restriction
4863 ("attribute% is not allowed for type%", P);
4866 Resolve (E1, P_Base_Type);
4867 Set_Etype (N, Universal_Integer);
4873 when Attribute_Position =>
4875 Set_Etype (N, Universal_Integer);
4881 when Attribute_Pred =>
4885 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
4886 Error_Msg_Name_1 := Aname;
4887 Error_Msg_Name_2 := Chars (P_Type);
4888 Check_SPARK_Restriction ("attribute% is not allowed for type%", P);
4891 Resolve (E1, P_Base_Type);
4892 Set_Etype (N, P_Base_Type);
4894 -- Since Pred works on the base type, we normally do no check for the
4895 -- floating-point case, since the base type is unconstrained. But we
4896 -- make an exception in Check_Float_Overflow mode.
4898 if Is_Floating_Point_Type (P_Type) then
4899 if Check_Float_Overflow
4900 and then not Range_Checks_Suppressed (P_Base_Type)
4902 Enable_Range_Check (E1);
4905 -- If not modular type, test for overflow check required
4908 if not Is_Modular_Integer_Type (P_Type)
4909 and then not Range_Checks_Suppressed (P_Base_Type)
4911 Enable_Range_Check (E1);
4919 -- Ada 2005 (AI-327): Dynamic ceiling priorities
4921 when Attribute_Priority =>
4922 if Ada_Version < Ada_2005 then
4923 Error_Attr ("% attribute is allowed only in Ada 2005 mode", P);
4928 -- The prefix must be a protected object (AARM D.5.2 (2/2))
4932 if Is_Protected_Type (Etype (P))
4933 or else (Is_Access_Type (Etype (P))
4934 and then Is_Protected_Type (Designated_Type (Etype (P))))
4936 Resolve (P, Etype (P));
4938 Error_Attr_P ("prefix of % attribute must be a protected object");
4941 Set_Etype (N, Standard_Integer);
4943 -- Must be called from within a protected procedure or entry of the
4944 -- protected object.
4951 while S /= Etype (P)
4952 and then S /= Standard_Standard
4957 if S = Standard_Standard then
4958 Error_Attr ("the attribute % is only allowed inside protected "
4963 Validate_Non_Static_Attribute_Function_Call;
4969 when Attribute_Range =>
4970 Check_Array_Or_Scalar_Type;
4971 Bad_Attribute_For_Predicate;
4973 if Ada_Version = Ada_83
4974 and then Is_Scalar_Type (P_Type)
4975 and then Comes_From_Source (N)
4978 ("(Ada 83) % attribute not allowed for scalar type", P);
4985 when Attribute_Result => Result : declare
4987 -- The enclosing scope, excluding loops for quantified expressions
4990 -- During analysis, CS is the postcondition subprogram and PS the
4991 -- source subprogram to which the postcondition applies. During
4992 -- pre-analysis, CS is the scope of the subprogram declaration.
4995 -- During pre-analysis, Prag is the enclosing pragma node if any
4998 -- Find the proper enclosing scope
5000 CS := Current_Scope;
5001 while Present (CS) loop
5003 -- Skip generated loops
5005 if Ekind (CS) = E_Loop then
5008 -- Skip the special _Parent scope generated to capture references
5009 -- to formals during the process of subprogram inlining.
5011 elsif Ekind (CS) = E_Function
5012 and then Chars (CS) = Name_uParent
5022 -- If the enclosing subprogram is always inlined, the enclosing
5023 -- postcondition will not be propagated to the expanded call.
5025 if not In_Spec_Expression
5026 and then Has_Pragma_Inline_Always (PS)
5027 and then Warn_On_Redundant_Constructs
5030 ("postconditions on inlined functions not enforced?r?", N);
5033 -- If we are in the scope of a function and in Spec_Expression mode,
5034 -- this is likely the prescan of the postcondition (or contract case,
5035 -- or test case) pragma, and we just set the proper type. If there is
5036 -- an error it will be caught when the real Analyze call is done.
5038 if Ekind (CS) = E_Function
5039 and then In_Spec_Expression
5043 if Chars (CS) /= Chars (P) then
5044 Error_Msg_Name_1 := Name_Result;
5047 ("incorrect prefix for % attribute, expected &", P, CS);
5051 -- Check in postcondition, Test_Case or Contract_Cases of function
5054 while Present (Prag)
5055 and then not Nkind_In (Prag, N_Pragma,
5056 N_Function_Specification,
5057 N_Aspect_Specification,
5060 Prag := Parent (Prag);
5063 -- In ASIS mode, the aspect itself is analyzed, in addition to the
5064 -- corresponding pragma. Do not issue errors when analyzing the
5067 if Nkind (Prag) = N_Aspect_Specification then
5070 -- Must have a pragma
5072 elsif Nkind (Prag) /= N_Pragma then
5074 ("% attribute can only appear in postcondition of function",
5077 -- Processing depends on which pragma we have
5080 case Get_Pragma_Id (Prag) is
5082 when Pragma_Test_Case =>
5084 Arg_Ens : constant Node_Id :=
5085 Get_Ensures_From_CTC_Pragma (Prag);
5090 while Arg /= Prag and then Arg /= Arg_Ens loop
5091 Arg := Parent (Arg);
5094 if Arg /= Arg_Ens then
5096 ("% attribute misplaced inside test case", P);
5100 when Pragma_Contract_Cases =>
5102 Aggr : constant Node_Id :=
5104 (Pragma_Argument_Associations (Prag)));
5110 and then Parent (Parent (Arg)) /= Aggr
5112 Arg := Parent (Arg);
5115 -- At this point, Parent (Arg) should be a component
5116 -- association. Attribute Result is only allowed in
5117 -- the expression part of this association.
5119 if Nkind (Parent (Arg)) /= N_Component_Association
5120 or else Arg /= Expression (Parent (Arg))
5123 ("% attribute misplaced inside contract cases",
5128 when Pragma_Postcondition | Pragma_Refined_Post =>
5133 ("% attribute can only appear in postcondition "
5134 & "of function", P);
5138 -- The attribute reference is a primary. If expressions follow,
5139 -- the attribute reference is really an indexable object, so
5140 -- rewrite and analyze as an indexed component.
5142 if Present (E1) then
5144 Make_Indexed_Component (Loc,
5146 Make_Attribute_Reference (Loc,
5147 Prefix => Relocate_Node (Prefix (N)),
5148 Attribute_Name => Name_Result),
5149 Expressions => Expressions (N)));
5154 Set_Etype (N, Etype (CS));
5156 -- If several functions with that name are visible, the intended
5157 -- one is the current scope.
5159 if Is_Overloaded (P) then
5161 Set_Is_Overloaded (P, False);
5164 -- Check the legality of attribute 'Result when it appears inside
5165 -- pragma Refined_Post. These specialized checks are required only
5166 -- when code generation is disabled. In the general case pragma
5167 -- Refined_Post is transformed into pragma Check by Process_PPCs
5168 -- which in turn is relocated to procedure _Postconditions. From
5169 -- then on the legality of 'Result is determined as usual.
5171 elsif not Expander_Active and then In_Refined_Post then
5172 PS := Current_Scope;
5174 -- The prefix denotes the proper related function
5176 if Is_Entity_Name (P)
5177 and then Ekind (Entity (P)) = E_Function
5178 and then Entity (P) = PS
5183 Error_Msg_Name_2 := Chars (PS);
5184 Error_Attr ("incorrect prefix for % attribute, expected %", P);
5187 Set_Etype (N, Etype (PS));
5189 -- Body case, where we must be inside a generated _Postconditions
5190 -- procedure, and the prefix must be on the scope stack, or else the
5191 -- attribute use is definitely misplaced. The postcondition itself
5192 -- may have generated transient scopes, and is not necessarily the
5196 while Present (CS) and then CS /= Standard_Standard loop
5197 if Chars (CS) = Name_uPostconditions then
5206 if Chars (CS) = Name_uPostconditions
5207 and then Ekind (PS) = E_Function
5211 if Nkind_In (P, N_Identifier, N_Operator_Symbol)
5212 and then Chars (P) = Chars (PS)
5216 -- Within an instance, the prefix designates the local renaming
5217 -- of the original generic.
5219 elsif Is_Entity_Name (P)
5220 and then Ekind (Entity (P)) = E_Function
5221 and then Present (Alias (Entity (P)))
5222 and then Chars (Alias (Entity (P))) = Chars (PS)
5227 Error_Msg_Name_2 := Chars (PS);
5229 ("incorrect prefix for % attribute, expected %", P);
5232 Rewrite (N, Make_Identifier (Sloc (N), Name_uResult));
5233 Analyze_And_Resolve (N, Etype (PS));
5237 ("% attribute can only appear in postcondition of function",
5247 when Attribute_Range_Length =>
5249 Check_Discrete_Type;
5250 Set_Etype (N, Universal_Integer);
5256 when Attribute_Read =>
5258 Check_Stream_Attribute (TSS_Stream_Read);
5259 Set_Etype (N, Standard_Void_Type);
5260 Resolve (N, Standard_Void_Type);
5261 Note_Possible_Modification (E2, Sure => True);
5267 when Attribute_Ref =>
5271 if Nkind (P) /= N_Expanded_Name
5272 or else not Is_RTE (P_Type, RE_Address)
5274 Error_Attr_P ("prefix of % attribute must be System.Address");
5277 Analyze_And_Resolve (E1, Any_Integer);
5278 Set_Etype (N, RTE (RE_Address));
5284 when Attribute_Remainder =>
5285 Check_Floating_Point_Type_2;
5286 Set_Etype (N, P_Base_Type);
5287 Resolve (E1, P_Base_Type);
5288 Resolve (E2, P_Base_Type);
5290 ---------------------
5291 -- Restriction_Set --
5292 ---------------------
5294 when Attribute_Restriction_Set => Restriction_Set : declare
5297 Unam : Unit_Name_Type;
5302 Check_System_Prefix;
5304 -- No_Dependence case
5306 if Nkind (E1) = N_Parameter_Association then
5307 pragma Assert (Chars (Selector_Name (E1)) = Name_No_Dependence);
5308 U := Explicit_Actual_Parameter (E1);
5310 if not OK_No_Dependence_Unit_Name (U) then
5311 Set_Boolean_Result (N, False);
5315 -- See if there is an entry already in the table. That's the
5316 -- case in which we can return True.
5318 for J in No_Dependences.First .. No_Dependences.Last loop
5319 if Designate_Same_Unit (U, No_Dependences.Table (J).Unit)
5320 and then No_Dependences.Table (J).Warn = False
5322 Set_Boolean_Result (N, True);
5327 -- If not in the No_Dependence table, result is False
5329 Set_Boolean_Result (N, False);
5331 -- In this case, we must ensure that the binder will reject any
5332 -- other unit in the partition that sets No_Dependence for this
5333 -- unit. We do that by making an entry in the special table kept
5334 -- for this purpose (if the entry is not there already).
5336 Unam := Get_Spec_Name (Get_Unit_Name (U));
5338 for J in Restriction_Set_Dependences.First ..
5339 Restriction_Set_Dependences.Last
5341 if Restriction_Set_Dependences.Table (J) = Unam then
5346 Restriction_Set_Dependences.Append (Unam);
5348 -- Normal restriction case
5351 if Nkind (E1) /= N_Identifier then
5352 Set_Boolean_Result (N, False);
5353 Error_Attr ("attribute % requires restriction identifier", E1);
5356 R := Get_Restriction_Id (Process_Restriction_Synonyms (E1));
5358 if R = Not_A_Restriction_Id then
5359 Set_Boolean_Result (N, False);
5360 Error_Msg_Node_1 := E1;
5361 Error_Attr ("invalid restriction identifier &", E1);
5363 elsif R not in Partition_Boolean_Restrictions then
5364 Set_Boolean_Result (N, False);
5365 Error_Msg_Node_1 := E1;
5367 ("& is not a boolean partition-wide restriction", E1);
5370 if Restriction_Active (R) then
5371 Set_Boolean_Result (N, True);
5373 Check_Restriction (R, N);
5374 Set_Boolean_Result (N, False);
5378 end Restriction_Set;
5384 when Attribute_Round =>
5386 Check_Decimal_Fixed_Point_Type;
5387 Set_Etype (N, P_Base_Type);
5389 -- Because the context is universal_real (3.5.10(12)) it is a
5390 -- legal context for a universal fixed expression. This is the
5391 -- only attribute whose functional description involves U_R.
5393 if Etype (E1) = Universal_Fixed then
5395 Conv : constant Node_Id := Make_Type_Conversion (Loc,
5396 Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc),
5397 Expression => Relocate_Node (E1));
5405 Resolve (E1, Any_Real);
5411 when Attribute_Rounding =>
5412 Check_Floating_Point_Type_1;
5413 Set_Etype (N, P_Base_Type);
5414 Resolve (E1, P_Base_Type);
5420 when Attribute_Safe_Emax =>
5421 Check_Floating_Point_Type_0;
5422 Set_Etype (N, Universal_Integer);
5428 when Attribute_Safe_First =>
5429 Check_Floating_Point_Type_0;
5430 Set_Etype (N, Universal_Real);
5436 when Attribute_Safe_Large =>
5439 Set_Etype (N, Universal_Real);
5445 when Attribute_Safe_Last =>
5446 Check_Floating_Point_Type_0;
5447 Set_Etype (N, Universal_Real);
5453 when Attribute_Safe_Small =>
5456 Set_Etype (N, Universal_Real);
5458 --------------------------
5459 -- Scalar_Storage_Order --
5460 --------------------------
5462 when Attribute_Scalar_Storage_Order => Scalar_Storage_Order :
5464 Ent : Entity_Id := Empty;
5470 if not (Is_Record_Type (P_Type) or else Is_Array_Type (P_Type)) then
5472 -- In GNAT mode, the attribute applies to generic types as well
5473 -- as composite types, and for non-composite types always returns
5474 -- the default bit order for the target.
5476 if not (GNAT_Mode and then Is_Generic_Type (P_Type))
5477 and then not In_Instance
5480 ("prefix of % attribute must be record or array type");
5482 elsif not Is_Generic_Type (P_Type) then
5483 if Bytes_Big_Endian then
5484 Ent := RTE (RE_High_Order_First);
5486 Ent := RTE (RE_Low_Order_First);
5490 elsif Bytes_Big_Endian xor Reverse_Storage_Order (P_Type) then
5491 Ent := RTE (RE_High_Order_First);
5494 Ent := RTE (RE_Low_Order_First);
5497 if Present (Ent) then
5498 Rewrite (N, New_Occurrence_Of (Ent, Loc));
5501 Set_Etype (N, RTE (RE_Bit_Order));
5504 -- Reset incorrect indication of staticness
5506 Set_Is_Static_Expression (N, False);
5507 end Scalar_Storage_Order;
5513 when Attribute_Scale =>
5515 Check_Decimal_Fixed_Point_Type;
5516 Set_Etype (N, Universal_Integer);
5522 when Attribute_Scaling =>
5523 Check_Floating_Point_Type_2;
5524 Set_Etype (N, P_Base_Type);
5525 Resolve (E1, P_Base_Type);
5531 when Attribute_Signed_Zeros =>
5532 Check_Floating_Point_Type_0;
5533 Set_Etype (N, Standard_Boolean);
5539 when Attribute_Size | Attribute_VADS_Size => Size :
5543 -- If prefix is parameterless function call, rewrite and resolve
5546 if Is_Entity_Name (P)
5547 and then Ekind (Entity (P)) = E_Function
5551 -- Similar processing for a protected function call
5553 elsif Nkind (P) = N_Selected_Component
5554 and then Ekind (Entity (Selector_Name (P))) = E_Function
5559 if Is_Object_Reference (P) then
5560 Check_Object_Reference (P);
5562 elsif Is_Entity_Name (P)
5563 and then (Is_Type (Entity (P))
5564 or else Ekind (Entity (P)) = E_Enumeration_Literal)
5568 elsif Nkind (P) = N_Type_Conversion
5569 and then not Comes_From_Source (P)
5573 -- Some other compilers allow dubious use of X'???'Size
5575 elsif Relaxed_RM_Semantics
5576 and then Nkind (P) = N_Attribute_Reference
5581 Error_Attr_P ("invalid prefix for % attribute");
5584 Check_Not_Incomplete_Type;
5586 Set_Etype (N, Universal_Integer);
5593 when Attribute_Small =>
5596 Set_Etype (N, Universal_Real);
5602 when Attribute_Storage_Pool |
5603 Attribute_Simple_Storage_Pool => Storage_Pool :
5607 if Is_Access_Type (P_Type) then
5608 if Ekind (P_Type) = E_Access_Subprogram_Type then
5610 ("cannot use % attribute for access-to-subprogram type");
5613 -- Set appropriate entity
5615 if Present (Associated_Storage_Pool (Root_Type (P_Type))) then
5616 Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type)));
5618 Set_Entity (N, RTE (RE_Global_Pool_Object));
5621 if Attr_Id = Attribute_Storage_Pool then
5622 if Present (Get_Rep_Pragma (Etype (Entity (N)),
5623 Name_Simple_Storage_Pool_Type))
5625 Error_Msg_Name_1 := Aname;
5626 Error_Msg_Warn := SPARK_Mode /= On;
5627 Error_Msg_N ("cannot use % attribute for type with simple "
5628 & "storage pool<<", N);
5629 Error_Msg_N ("\Program_Error [<<", N);
5632 (N, Make_Raise_Program_Error
5633 (Sloc (N), Reason => PE_Explicit_Raise));
5636 Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
5638 -- In the Simple_Storage_Pool case, verify that the pool entity is
5639 -- actually of a simple storage pool type, and set the attribute's
5640 -- type to the pool object's type.
5643 if not Present (Get_Rep_Pragma (Etype (Entity (N)),
5644 Name_Simple_Storage_Pool_Type))
5647 ("cannot use % attribute for type without simple " &
5651 Set_Etype (N, Etype (Entity (N)));
5654 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
5655 -- Storage_Pool since this attribute is not defined for such
5656 -- types (RM E.2.3(22)).
5658 Validate_Remote_Access_To_Class_Wide_Type (N);
5661 Error_Attr_P ("prefix of % attribute must be access type");
5669 when Attribute_Storage_Size => Storage_Size :
5673 if Is_Task_Type (P_Type) then
5674 Set_Etype (N, Universal_Integer);
5676 -- Use with tasks is an obsolescent feature
5678 Check_Restriction (No_Obsolescent_Features, P);
5680 elsif Is_Access_Type (P_Type) then
5681 if Ekind (P_Type) = E_Access_Subprogram_Type then
5683 ("cannot use % attribute for access-to-subprogram type");
5686 if Is_Entity_Name (P)
5687 and then Is_Type (Entity (P))
5690 Set_Etype (N, Universal_Integer);
5692 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
5693 -- Storage_Size since this attribute is not defined for
5694 -- such types (RM E.2.3(22)).
5696 Validate_Remote_Access_To_Class_Wide_Type (N);
5698 -- The prefix is allowed to be an implicit dereference of an
5699 -- access value designating a task.
5703 Set_Etype (N, Universal_Integer);
5707 Error_Attr_P ("prefix of % attribute must be access or task type");
5715 when Attribute_Storage_Unit =>
5716 Standard_Attribute (Ttypes.System_Storage_Unit);
5722 when Attribute_Stream_Size =>
5726 if Is_Entity_Name (P)
5727 and then Is_Elementary_Type (Entity (P))
5729 Set_Etype (N, Universal_Integer);
5731 Error_Attr_P ("invalid prefix for % attribute");
5738 when Attribute_Stub_Type =>
5742 if Is_Remote_Access_To_Class_Wide_Type (Base_Type (P_Type)) then
5744 -- For a real RACW [sub]type, use corresponding stub type
5746 if not Is_Generic_Type (P_Type) then
5749 (Corresponding_Stub_Type (Base_Type (P_Type)), Loc));
5751 -- For a generic type (that has been marked as an RACW using the
5752 -- Remote_Access_Type aspect or pragma), use a generic RACW stub
5753 -- type. Note that if the actual is not a remote access type, the
5754 -- instantiation will fail.
5757 -- Note: we go to the underlying type here because the view
5758 -- returned by RTE (RE_RACW_Stub_Type) might be incomplete.
5762 (Underlying_Type (RTE (RE_RACW_Stub_Type)), Loc));
5767 ("prefix of% attribute must be remote access to classwide");
5774 when Attribute_Succ =>
5778 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
5779 Error_Msg_Name_1 := Aname;
5780 Error_Msg_Name_2 := Chars (P_Type);
5781 Check_SPARK_Restriction ("attribute% is not allowed for type%", P);
5784 Resolve (E1, P_Base_Type);
5785 Set_Etype (N, P_Base_Type);
5787 -- Since Pred works on the base type, we normally do no check for the
5788 -- floating-point case, since the base type is unconstrained. But we
5789 -- make an exception in Check_Float_Overflow mode.
5791 if Is_Floating_Point_Type (P_Type) then
5792 if Check_Float_Overflow
5793 and then not Range_Checks_Suppressed (P_Base_Type)
5795 Enable_Range_Check (E1);
5798 -- If not modular type, test for overflow check required
5801 if not Is_Modular_Integer_Type (P_Type)
5802 and then not Range_Checks_Suppressed (P_Base_Type)
5804 Enable_Range_Check (E1);
5808 --------------------------------
5809 -- System_Allocator_Alignment --
5810 --------------------------------
5812 when Attribute_System_Allocator_Alignment =>
5813 Standard_Attribute (Ttypes.System_Allocator_Alignment);
5819 when Attribute_Tag => Tag :
5824 if not Is_Tagged_Type (P_Type) then
5825 Error_Attr_P ("prefix of % attribute must be tagged");
5827 -- Next test does not apply to generated code why not, and what does
5828 -- the illegal reference mean???
5830 elsif Is_Object_Reference (P)
5831 and then not Is_Class_Wide_Type (P_Type)
5832 and then Comes_From_Source (N)
5835 ("% attribute can only be applied to objects " &
5836 "of class - wide type");
5839 -- The prefix cannot be an incomplete type. However, references to
5840 -- 'Tag can be generated when expanding interface conversions, and
5843 if Comes_From_Source (N) then
5844 Check_Not_Incomplete_Type;
5847 -- Set appropriate type
5849 Set_Etype (N, RTE (RE_Tag));
5856 when Attribute_Target_Name => Target_Name : declare
5857 TN : constant String := Sdefault.Target_Name.all;
5861 Check_Standard_Prefix;
5865 if TN (TL) = '/' or else TN (TL) = '\' then
5870 Make_String_Literal (Loc,
5871 Strval => TN (TN'First .. TL)));
5872 Analyze_And_Resolve (N, Standard_String);
5879 when Attribute_Terminated =>
5881 Set_Etype (N, Standard_Boolean);
5888 when Attribute_To_Address => To_Address : declare
5894 Check_System_Prefix;
5896 Generate_Reference (RTE (RE_Address), P);
5897 Analyze_And_Resolve (E1, Any_Integer);
5898 Set_Etype (N, RTE (RE_Address));
5900 -- Static expression case, check range and set appropriate type
5902 if Is_OK_Static_Expression (E1) then
5903 Val := Expr_Value (E1);
5905 if Val < -(2 ** UI_From_Int (Standard'Address_Size - 1))
5907 Val > 2 ** UI_From_Int (Standard'Address_Size) - 1
5909 Error_Attr ("address value out of range for % attribute", E1);
5912 -- In most cases the expression is a numeric literal or some other
5913 -- address expression, but if it is a declared constant it may be
5914 -- of a compatible type that must be left on the node.
5916 if Is_Entity_Name (E1) then
5919 -- Set type to universal integer if negative
5922 Set_Etype (E1, Universal_Integer);
5924 -- Otherwise set type to Unsigned_64 to accomodate max values
5927 Set_Etype (E1, Standard_Unsigned_64);
5936 when Attribute_To_Any =>
5938 Check_PolyORB_Attribute;
5939 Set_Etype (N, RTE (RE_Any));
5945 when Attribute_Truncation =>
5946 Check_Floating_Point_Type_1;
5947 Resolve (E1, P_Base_Type);
5948 Set_Etype (N, P_Base_Type);
5954 when Attribute_Type_Class =>
5957 Check_Not_Incomplete_Type;
5958 Set_Etype (N, RTE (RE_Type_Class));
5964 when Attribute_TypeCode =>
5966 Check_PolyORB_Attribute;
5967 Set_Etype (N, RTE (RE_TypeCode));
5973 when Attribute_Type_Key =>
5977 -- This processing belongs in Eval_Attribute ???
5980 function Type_Key return String_Id;
5981 -- A very preliminary implementation. For now, a signature
5982 -- consists of only the type name. This is clearly incomplete
5983 -- (e.g., adding a new field to a record type should change the
5984 -- type's Type_Key attribute).
5990 function Type_Key return String_Id is
5991 Full_Name : constant String_Id :=
5992 Fully_Qualified_Name_String (Entity (P));
5995 -- Copy all characters in Full_Name but the trailing NUL
5998 for J in 1 .. String_Length (Full_Name) - 1 loop
5999 Store_String_Char (Get_String_Char (Full_Name, Int (J)));
6002 Store_String_Chars ("'Type_Key");
6007 Rewrite (N, Make_String_Literal (Loc, Type_Key));
6010 Analyze_And_Resolve (N, Standard_String);
6016 when Attribute_UET_Address =>
6018 Check_Unit_Name (P);
6019 Set_Etype (N, RTE (RE_Address));
6021 -----------------------
6022 -- Unbiased_Rounding --
6023 -----------------------
6025 when Attribute_Unbiased_Rounding =>
6026 Check_Floating_Point_Type_1;
6027 Set_Etype (N, P_Base_Type);
6028 Resolve (E1, P_Base_Type);
6030 ----------------------
6031 -- Unchecked_Access --
6032 ----------------------
6034 when Attribute_Unchecked_Access =>
6035 if Comes_From_Source (N) then
6036 Check_Restriction (No_Unchecked_Access, N);
6039 Analyze_Access_Attribute;
6041 -------------------------
6042 -- Unconstrained_Array --
6043 -------------------------
6045 when Attribute_Unconstrained_Array =>
6048 Check_Not_Incomplete_Type;
6049 Set_Etype (N, Standard_Boolean);
6051 ------------------------------
6052 -- Universal_Literal_String --
6053 ------------------------------
6055 -- This is a GNAT specific attribute whose prefix must be a named
6056 -- number where the expression is either a single numeric literal,
6057 -- or a numeric literal immediately preceded by a minus sign. The
6058 -- result is equivalent to a string literal containing the text of
6059 -- the literal as it appeared in the source program with a possible
6060 -- leading minus sign.
6062 when Attribute_Universal_Literal_String => Universal_Literal_String :
6066 if not Is_Entity_Name (P)
6067 or else Ekind (Entity (P)) not in Named_Kind
6069 Error_Attr_P ("prefix for % attribute must be named number");
6076 Src : Source_Buffer_Ptr;
6079 Expr := Original_Node (Expression (Parent (Entity (P))));
6081 if Nkind (Expr) = N_Op_Minus then
6083 Expr := Original_Node (Right_Opnd (Expr));
6088 if not Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then
6090 ("named number for % attribute must be simple literal", N);
6093 -- Build string literal corresponding to source literal text
6098 Store_String_Char (Get_Char_Code ('-'));
6102 Src := Source_Text (Get_Source_File_Index (S));
6104 while Src (S) /= ';' and then Src (S) /= ' ' loop
6105 Store_String_Char (Get_Char_Code (Src (S)));
6109 -- Now we rewrite the attribute with the string literal
6112 Make_String_Literal (Loc, End_String));
6116 end Universal_Literal_String;
6118 -------------------------
6119 -- Unrestricted_Access --
6120 -------------------------
6122 -- This is a GNAT specific attribute which is like Access except that
6123 -- all scope checks and checks for aliased views are omitted. It is
6124 -- documented as being equivalent to the use of the Address attribute
6125 -- followed by an unchecked conversion to the target access type.
6127 when Attribute_Unrestricted_Access =>
6129 -- If from source, deal with relevant restrictions
6131 if Comes_From_Source (N) then
6132 Check_Restriction (No_Unchecked_Access, N);
6134 if Nkind (P) in N_Has_Entity
6135 and then Present (Entity (P))
6136 and then Is_Object (Entity (P))
6138 Check_Restriction (No_Implicit_Aliasing, N);
6142 if Is_Entity_Name (P) then
6143 Set_Address_Taken (Entity (P));
6146 -- It might seem reasonable to call Address_Checks here to apply the
6147 -- same set of semantic checks that we enforce for 'Address (after
6148 -- all we document Unrestricted_Access as being equivalent to the
6149 -- use of Address followed by an Unchecked_Conversion). However, if
6150 -- we do enable these checks, we get multiple failures in both the
6151 -- compiler run-time and in our regression test suite, so we leave
6152 -- out these checks for now. To be investigated further some time???
6156 -- Now complete analysis using common access processing
6158 Analyze_Access_Attribute;
6164 when Attribute_Update => Update : declare
6165 Comps : Elist_Id := No_Elist;
6168 procedure Check_Component_Reference
6171 -- Comp is a record component (possibly a discriminant) and Typ is a
6172 -- record type. Determine whether Comp is a legal component of Typ.
6173 -- Emit an error if Comp mentions a discriminant or is not a unique
6174 -- component reference in the update aggregate.
6176 -------------------------------
6177 -- Check_Component_Reference --
6178 -------------------------------
6180 procedure Check_Component_Reference
6184 Comp_Name : constant Name_Id := Chars (Comp);
6186 function Is_Duplicate_Component return Boolean;
6187 -- Determine whether component Comp already appears in list Comps
6189 ----------------------------
6190 -- Is_Duplicate_Component --
6191 ----------------------------
6193 function Is_Duplicate_Component return Boolean is
6194 Comp_Elmt : Elmt_Id;
6197 if Present (Comps) then
6198 Comp_Elmt := First_Elmt (Comps);
6199 while Present (Comp_Elmt) loop
6200 if Chars (Node (Comp_Elmt)) = Comp_Name then
6204 Next_Elmt (Comp_Elmt);
6209 end Is_Duplicate_Component;
6213 Comp_Or_Discr : Entity_Id;
6215 -- Start of processing for Check_Component_Reference
6218 -- Find the discriminant or component whose name corresponds to
6219 -- Comp. A simple character comparison is sufficient because all
6220 -- visible names within a record type are unique.
6222 Comp_Or_Discr := First_Entity (Typ);
6223 while Present (Comp_Or_Discr) loop
6224 if Chars (Comp_Or_Discr) = Comp_Name then
6226 -- Record component entity and type in the given aggregate
6227 -- choice, for subsequent resolution.
6229 Set_Entity (Comp, Comp_Or_Discr);
6230 Set_Etype (Comp, Etype (Comp_Or_Discr));
6234 Comp_Or_Discr := Next_Entity (Comp_Or_Discr);
6237 -- Diagnose possible illegal references
6239 if Present (Comp_Or_Discr) then
6240 if Ekind (Comp_Or_Discr) = E_Discriminant then
6242 ("attribute % may not modify record discriminants", Comp);
6244 else pragma Assert (Ekind (Comp_Or_Discr) = E_Component);
6245 if Is_Duplicate_Component then
6246 Error_Msg_NE ("component & already updated", Comp, Comp);
6248 -- Mark this component as processed
6252 Comps := New_Elmt_List;
6255 Append_Elmt (Comp, Comps);
6259 -- The update aggregate mentions an entity that does not belong to
6264 ("& is not a component of aggregate subtype", Comp, Comp);
6266 end Check_Component_Reference;
6272 Comp_Type : Entity_Id;
6274 -- Start of processing for Update
6278 Check_Ada_2012_Attribute;
6280 if not Is_Object_Reference (P) then
6281 Error_Attr_P ("prefix of attribute % must denote an object");
6283 elsif not Is_Array_Type (P_Type)
6284 and then not Is_Record_Type (P_Type)
6286 Error_Attr_P ("prefix of attribute % must be a record or array");
6288 elsif Is_Limited_View (P_Type) then
6289 Error_Attr ("prefix of attribute % cannot be limited", N);
6291 elsif Nkind (E1) /= N_Aggregate then
6292 Error_Attr ("attribute % requires component association list", N);
6295 -- Inspect the update aggregate, looking at all the associations and
6296 -- choices. Perform the following checks:
6298 -- 1) Legality of "others" in all cases
6299 -- 2) Component legality for records
6301 -- The remaining checks are performed on the expanded attribute
6303 Assoc := First (Component_Associations (E1));
6304 while Present (Assoc) loop
6305 Comp := First (Choices (Assoc));
6306 Analyze (Expression (Assoc));
6308 while Present (Comp) loop
6309 if Nkind (Comp) = N_Others_Choice then
6311 ("others choice not allowed in attribute %", Comp);
6313 elsif Is_Array_Type (P_Type) then
6316 Index_Type : Entity_Id;
6319 if Nkind (First (Choices (Assoc))) /= N_Aggregate then
6321 -- Choices denote separate components of one-
6322 -- dimensional array.
6324 Index_Type := First_Index (P_Type);
6326 if Present (Next_Index (Index_Type)) then
6328 ("too few subscripts in array reference", Comp);
6331 Index := First (Choices (Assoc));
6332 while Present (Index) loop
6333 if Nkind (Index) = N_Range then
6335 (Low_Bound (Index), Etype (Index_Type));
6337 (High_Bound (Index), Etype (Index_Type));
6338 Set_Etype (Index, Etype (Index_Type));
6341 Analyze_And_Resolve (Index, Etype (Index_Type));
6347 -- Choice is a sequence of indexes for each dimension
6350 Expr := First (Choices (Assoc));
6351 while Present (Expr) loop
6352 Index_Type := First_Index (P_Type);
6353 Index := First (Expressions (Expr));
6354 while Present (Index_Type)
6355 and then Present (Index)
6357 Analyze_And_Resolve (Index, Etype (Index_Type));
6358 Next_Index (Index_Type);
6362 if Present (Index) or else Present (Index_Type) then
6364 ("dimension mismatch in index list", Assoc);
6372 elsif Is_Record_Type (P_Type) then
6374 -- Make sure we have an identifier. Old SPARK allowed
6375 -- a component selection e.g. A.B in the corresponding
6376 -- context, but we do not yet permit this for 'Update.
6378 if Nkind (Comp) /= N_Identifier then
6379 Error_Msg_N ("name should be identifier or OTHERS", Comp);
6381 Check_Component_Reference (Comp, P_Type);
6383 -- Verify that all choices in an association denote
6384 -- components of the same type.
6386 if No (Etype (Comp)) then
6389 elsif No (Comp_Type) then
6390 Comp_Type := Base_Type (Etype (Comp));
6392 elsif Comp_Type /= Base_Type (Etype (Comp)) then
6394 ("components in choice list must have same type",
6406 -- The type of attribute Update is that of the prefix
6408 Set_Etype (N, P_Type);
6415 when Attribute_Val => Val : declare
6418 Check_Discrete_Type;
6420 if Is_Boolean_Type (P_Type) then
6421 Error_Msg_Name_1 := Aname;
6422 Error_Msg_Name_2 := Chars (P_Type);
6423 Check_SPARK_Restriction
6424 ("attribute% is not allowed for type%", P);
6427 Resolve (E1, Any_Integer);
6428 Set_Etype (N, P_Base_Type);
6430 -- Note, we need a range check in general, but we wait for the
6431 -- Resolve call to do this, since we want to let Eval_Attribute
6432 -- have a chance to find an static illegality first.
6439 when Attribute_Valid =>
6442 -- Ignore check for object if we have a 'Valid reference generated
6443 -- by the expanded code, since in some cases valid checks can occur
6444 -- on items that are names, but are not objects (e.g. attributes).
6446 if Comes_From_Source (N) then
6447 Check_Object_Reference (P);
6450 if not Is_Scalar_Type (P_Type) then
6451 Error_Attr_P ("object for % attribute must be of scalar type");
6454 -- If the attribute appears within the subtype's own predicate
6455 -- function, then issue a warning that this will cause infinite
6459 Pred_Func : constant Entity_Id := Predicate_Function (P_Type);
6462 if Present (Pred_Func) and then Current_Scope = Pred_Func then
6464 ("attribute Valid requires a predicate check??", N);
6465 Error_Msg_N ("\and will result in infinite recursion??", N);
6469 Set_Etype (N, Standard_Boolean);
6475 when Attribute_Valid_Scalars =>
6477 Check_Object_Reference (P);
6479 if No_Scalar_Parts (P_Type) then
6480 Error_Attr_P ("??attribute % always True, no scalars to check");
6483 Set_Etype (N, Standard_Boolean);
6489 when Attribute_Value => Value :
6491 Check_SPARK_Restriction_On_Attribute;
6495 -- Case of enumeration type
6497 -- When an enumeration type appears in an attribute reference, all
6498 -- literals of the type are marked as referenced. This must only be
6499 -- done if the attribute reference appears in the current source.
6500 -- Otherwise the information on references may differ between a
6501 -- normal compilation and one that performs inlining.
6503 if Is_Enumeration_Type (P_Type)
6504 and then In_Extended_Main_Code_Unit (N)
6506 Check_Restriction (No_Enumeration_Maps, N);
6508 -- Mark all enumeration literals as referenced, since the use of
6509 -- the Value attribute can implicitly reference any of the
6510 -- literals of the enumeration base type.
6513 Ent : Entity_Id := First_Literal (P_Base_Type);
6515 while Present (Ent) loop
6516 Set_Referenced (Ent);
6522 -- Set Etype before resolving expression because expansion of
6523 -- expression may require enclosing type. Note that the type
6524 -- returned by 'Value is the base type of the prefix type.
6526 Set_Etype (N, P_Base_Type);
6527 Validate_Non_Static_Attribute_Function_Call;
6529 -- Check restriction No_Fixed_IO
6531 if Restriction_Check_Required (No_Fixed_IO)
6532 and then Is_Fixed_Point_Type (P_Type)
6534 Check_Restriction (No_Fixed_IO, P);
6542 when Attribute_Value_Size =>
6545 Check_Not_Incomplete_Type;
6546 Set_Etype (N, Universal_Integer);
6552 when Attribute_Version =>
6555 Set_Etype (N, RTE (RE_Version_String));
6561 when Attribute_Wchar_T_Size =>
6562 Standard_Attribute (Interfaces_Wchar_T_Size);
6568 when Attribute_Wide_Image => Wide_Image :
6570 Check_SPARK_Restriction_On_Attribute;
6572 Set_Etype (N, Standard_Wide_String);
6574 Resolve (E1, P_Base_Type);
6575 Validate_Non_Static_Attribute_Function_Call;
6577 -- Check restriction No_Fixed_IO
6579 if Restriction_Check_Required (No_Fixed_IO)
6580 and then Is_Fixed_Point_Type (P_Type)
6582 Check_Restriction (No_Fixed_IO, P);
6586 ---------------------
6587 -- Wide_Wide_Image --
6588 ---------------------
6590 when Attribute_Wide_Wide_Image => Wide_Wide_Image :
6593 Set_Etype (N, Standard_Wide_Wide_String);
6595 Resolve (E1, P_Base_Type);
6596 Validate_Non_Static_Attribute_Function_Call;
6598 -- Check restriction No_Fixed_IO
6600 if Restriction_Check_Required (No_Fixed_IO)
6601 and then Is_Fixed_Point_Type (P_Type)
6603 Check_Restriction (No_Fixed_IO, P);
6605 end Wide_Wide_Image;
6611 when Attribute_Wide_Value => Wide_Value :
6613 Check_SPARK_Restriction_On_Attribute;
6617 -- Set Etype before resolving expression because expansion
6618 -- of expression may require enclosing type.
6620 Set_Etype (N, P_Type);
6621 Validate_Non_Static_Attribute_Function_Call;
6623 -- Check restriction No_Fixed_IO
6625 if Restriction_Check_Required (No_Fixed_IO)
6626 and then Is_Fixed_Point_Type (P_Type)
6628 Check_Restriction (No_Fixed_IO, P);
6632 ---------------------
6633 -- Wide_Wide_Value --
6634 ---------------------
6636 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
6641 -- Set Etype before resolving expression because expansion
6642 -- of expression may require enclosing type.
6644 Set_Etype (N, P_Type);
6645 Validate_Non_Static_Attribute_Function_Call;
6647 -- Check restriction No_Fixed_IO
6649 if Restriction_Check_Required (No_Fixed_IO)
6650 and then Is_Fixed_Point_Type (P_Type)
6652 Check_Restriction (No_Fixed_IO, P);
6654 end Wide_Wide_Value;
6656 ---------------------
6657 -- Wide_Wide_Width --
6658 ---------------------
6660 when Attribute_Wide_Wide_Width =>
6663 Set_Etype (N, Universal_Integer);
6669 when Attribute_Wide_Width =>
6670 Check_SPARK_Restriction_On_Attribute;
6673 Set_Etype (N, Universal_Integer);
6679 when Attribute_Width =>
6680 Check_SPARK_Restriction_On_Attribute;
6683 Set_Etype (N, Universal_Integer);
6689 when Attribute_Word_Size =>
6690 Standard_Attribute (System_Word_Size);
6696 when Attribute_Write =>
6698 Check_Stream_Attribute (TSS_Stream_Write);
6699 Set_Etype (N, Standard_Void_Type);
6700 Resolve (N, Standard_Void_Type);
6704 -- All errors raise Bad_Attribute, so that we get out before any further
6705 -- damage occurs when an error is detected (for example, if we check for
6706 -- one attribute expression, and the check succeeds, we want to be able
6707 -- to proceed securely assuming that an expression is in fact present.
6709 -- Note: we set the attribute analyzed in this case to prevent any
6710 -- attempt at reanalysis which could generate spurious error msgs.
6713 when Bad_Attribute =>
6715 Set_Etype (N, Any_Type);
6717 end Analyze_Attribute;
6719 --------------------
6720 -- Eval_Attribute --
6721 --------------------
6723 procedure Eval_Attribute (N : Node_Id) is
6724 Loc : constant Source_Ptr := Sloc (N);
6725 Aname : constant Name_Id := Attribute_Name (N);
6726 Id : constant Attribute_Id := Get_Attribute_Id (Aname);
6727 P : constant Node_Id := Prefix (N);
6729 C_Type : constant Entity_Id := Etype (N);
6730 -- The type imposed by the context
6733 -- First expression, or Empty if none
6736 -- Second expression, or Empty if none
6738 P_Entity : Entity_Id;
6739 -- Entity denoted by prefix
6742 -- The type of the prefix
6744 P_Base_Type : Entity_Id;
6745 -- The base type of the prefix type
6747 P_Root_Type : Entity_Id;
6748 -- The root type of the prefix type
6751 -- True if the result is Static. This is set by the general processing
6752 -- to true if the prefix is static, and all expressions are static. It
6753 -- can be reset as processing continues for particular attributes
6755 Lo_Bound, Hi_Bound : Node_Id;
6756 -- Expressions for low and high bounds of type or array index referenced
6757 -- by First, Last, or Length attribute for array, set by Set_Bounds.
6760 -- Constraint error node used if we have an attribute reference has
6761 -- an argument that raises a constraint error. In this case we replace
6762 -- the attribute with a raise constraint_error node. This is important
6763 -- processing, since otherwise gigi might see an attribute which it is
6764 -- unprepared to deal with.
6766 procedure Check_Concurrent_Discriminant (Bound : Node_Id);
6767 -- If Bound is a reference to a discriminant of a task or protected type
6768 -- occurring within the object's body, rewrite attribute reference into
6769 -- a reference to the corresponding discriminal. Use for the expansion
6770 -- of checks against bounds of entry family index subtypes.
6772 procedure Check_Expressions;
6773 -- In case where the attribute is not foldable, the expressions, if
6774 -- any, of the attribute, are in a non-static context. This procedure
6775 -- performs the required additional checks.
6777 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean;
6778 -- Determines if the given type has compile time known bounds. Note
6779 -- that we enter the case statement even in cases where the prefix
6780 -- type does NOT have known bounds, so it is important to guard any
6781 -- attempt to evaluate both bounds with a call to this function.
6783 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint);
6784 -- This procedure is called when the attribute N has a non-static
6785 -- but compile time known value given by Val. It includes the
6786 -- necessary checks for out of range values.
6788 function Fore_Value return Nat;
6789 -- Computes the Fore value for the current attribute prefix, which is
6790 -- known to be a static fixed-point type. Used by Fore and Width.
6792 function Is_VAX_Float (Typ : Entity_Id) return Boolean;
6793 -- Determine whether Typ denotes a VAX floating point type
6795 function Mantissa return Uint;
6796 -- Returns the Mantissa value for the prefix type
6798 procedure Set_Bounds;
6799 -- Used for First, Last and Length attributes applied to an array or
6800 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
6801 -- and high bound expressions for the index referenced by the attribute
6802 -- designator (i.e. the first index if no expression is present, and the
6803 -- N'th index if the value N is present as an expression). Also used for
6804 -- First and Last of scalar types and for First_Valid and Last_Valid.
6805 -- Static is reset to False if the type or index type is not statically
6808 function Statically_Denotes_Entity (N : Node_Id) return Boolean;
6809 -- Verify that the prefix of a potentially static array attribute
6810 -- satisfies the conditions of 4.9 (14).
6812 -----------------------------------
6813 -- Check_Concurrent_Discriminant --
6814 -----------------------------------
6816 procedure Check_Concurrent_Discriminant (Bound : Node_Id) is
6818 -- The concurrent (task or protected) type
6821 if Nkind (Bound) = N_Identifier
6822 and then Ekind (Entity (Bound)) = E_Discriminant
6823 and then Is_Concurrent_Record_Type (Scope (Entity (Bound)))
6825 Tsk := Corresponding_Concurrent_Type (Scope (Entity (Bound)));
6827 if In_Open_Scopes (Tsk) and then Has_Completion (Tsk) then
6829 -- Find discriminant of original concurrent type, and use
6830 -- its current discriminal, which is the renaming within
6831 -- the task/protected body.
6835 (Find_Body_Discriminal (Entity (Bound)), Loc));
6838 end Check_Concurrent_Discriminant;
6840 -----------------------
6841 -- Check_Expressions --
6842 -----------------------
6844 procedure Check_Expressions is
6848 while Present (E) loop
6849 Check_Non_Static_Context (E);
6852 end Check_Expressions;
6854 ----------------------------------
6855 -- Compile_Time_Known_Attribute --
6856 ----------------------------------
6858 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is
6859 T : constant Entity_Id := Etype (N);
6862 Fold_Uint (N, Val, False);
6864 -- Check that result is in bounds of the type if it is static
6866 if Is_In_Range (N, T, Assume_Valid => False) then
6869 elsif Is_Out_Of_Range (N, T) then
6870 Apply_Compile_Time_Constraint_Error
6871 (N, "value not in range of}??", CE_Range_Check_Failed);
6873 elsif not Range_Checks_Suppressed (T) then
6874 Enable_Range_Check (N);
6877 Set_Do_Range_Check (N, False);
6879 end Compile_Time_Known_Attribute;
6881 -------------------------------
6882 -- Compile_Time_Known_Bounds --
6883 -------------------------------
6885 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is
6888 Compile_Time_Known_Value (Type_Low_Bound (Typ))
6890 Compile_Time_Known_Value (Type_High_Bound (Typ));
6891 end Compile_Time_Known_Bounds;
6897 -- Note that the Fore calculation is based on the actual values
6898 -- of the bounds, and does not take into account possible rounding.
6900 function Fore_Value return Nat is
6901 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
6902 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
6903 Small : constant Ureal := Small_Value (P_Type);
6904 Lo_Real : constant Ureal := Lo * Small;
6905 Hi_Real : constant Ureal := Hi * Small;
6910 -- Bounds are given in terms of small units, so first compute
6911 -- proper values as reals.
6913 T := UR_Max (abs Lo_Real, abs Hi_Real);
6916 -- Loop to compute proper value if more than one digit required
6918 while T >= Ureal_10 loop
6930 function Is_VAX_Float (Typ : Entity_Id) return Boolean is
6933 Is_Floating_Point_Type (Typ)
6935 (Float_Format = 'V' or else Float_Rep (Typ) = VAX_Native);
6942 -- Table of mantissa values accessed by function Computed using
6945 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
6947 -- where D is T'Digits (RM83 3.5.7)
6949 Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := (
6991 function Mantissa return Uint is
6994 UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type))));
7001 procedure Set_Bounds is
7007 -- For a string literal subtype, we have to construct the bounds.
7008 -- Valid Ada code never applies attributes to string literals, but
7009 -- it is convenient to allow the expander to generate attribute
7010 -- references of this type (e.g. First and Last applied to a string
7013 -- Note that the whole point of the E_String_Literal_Subtype is to
7014 -- avoid this construction of bounds, but the cases in which we
7015 -- have to materialize them are rare enough that we don't worry.
7017 -- The low bound is simply the low bound of the base type. The
7018 -- high bound is computed from the length of the string and this
7021 if Ekind (P_Type) = E_String_Literal_Subtype then
7022 Ityp := Etype (First_Index (Base_Type (P_Type)));
7023 Lo_Bound := Type_Low_Bound (Ityp);
7026 Make_Integer_Literal (Sloc (P),
7028 Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1);
7030 Set_Parent (Hi_Bound, P);
7031 Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound));
7034 -- For non-array case, just get bounds of scalar type
7036 elsif Is_Scalar_Type (P_Type) then
7039 -- For a fixed-point type, we must freeze to get the attributes
7040 -- of the fixed-point type set now so we can reference them.
7042 if Is_Fixed_Point_Type (P_Type)
7043 and then not Is_Frozen (Base_Type (P_Type))
7044 and then Compile_Time_Known_Value (Type_Low_Bound (P_Type))
7045 and then Compile_Time_Known_Value (Type_High_Bound (P_Type))
7047 Freeze_Fixed_Point_Type (Base_Type (P_Type));
7050 -- For array case, get type of proper index
7056 Ndim := UI_To_Int (Expr_Value (E1));
7059 Indx := First_Index (P_Type);
7060 for J in 1 .. Ndim - 1 loop
7064 -- If no index type, get out (some other error occurred, and
7065 -- we don't have enough information to complete the job).
7073 Ityp := Etype (Indx);
7076 -- A discrete range in an index constraint is allowed to be a
7077 -- subtype indication. This is syntactically a pain, but should
7078 -- not propagate to the entity for the corresponding index subtype.
7079 -- After checking that the subtype indication is legal, the range
7080 -- of the subtype indication should be transfered to the entity.
7081 -- The attributes for the bounds should remain the simple retrievals
7082 -- that they are now.
7084 Lo_Bound := Type_Low_Bound (Ityp);
7085 Hi_Bound := Type_High_Bound (Ityp);
7087 if not Is_Static_Subtype (Ityp) then
7092 -------------------------------
7093 -- Statically_Denotes_Entity --
7094 -------------------------------
7096 function Statically_Denotes_Entity (N : Node_Id) return Boolean is
7100 if not Is_Entity_Name (N) then
7107 Nkind (Parent (E)) /= N_Object_Renaming_Declaration
7108 or else Statically_Denotes_Entity (Renamed_Object (E));
7109 end Statically_Denotes_Entity;
7111 -- Start of processing for Eval_Attribute
7114 -- Acquire first two expressions (at the moment, no attributes take more
7115 -- than two expressions in any case).
7117 if Present (Expressions (N)) then
7118 E1 := First (Expressions (N));
7125 -- Special processing for Enabled attribute. This attribute has a very
7126 -- special prefix, and the easiest way to avoid lots of special checks
7127 -- to protect this special prefix from causing trouble is to deal with
7128 -- this attribute immediately and be done with it.
7130 if Id = Attribute_Enabled then
7132 -- We skip evaluation if the expander is not active. This is not just
7133 -- an optimization. It is of key importance that we not rewrite the
7134 -- attribute in a generic template, since we want to pick up the
7135 -- setting of the check in the instance, and testing expander active
7136 -- is as easy way of doing this as any.
7138 if Expander_Active then
7140 C : constant Check_Id := Get_Check_Id (Chars (P));
7145 if C in Predefined_Check_Id then
7146 R := Scope_Suppress.Suppress (C);
7148 R := Is_Check_Suppressed (Empty, C);
7152 R := Is_Check_Suppressed (Entity (E1), C);
7155 Rewrite (N, New_Occurrence_Of (Boolean_Literals (not R), Loc));
7162 -- Special processing for cases where the prefix is an object. For
7163 -- this purpose, a string literal counts as an object (attributes
7164 -- of string literals can only appear in generated code).
7166 if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then
7168 -- For Component_Size, the prefix is an array object, and we apply
7169 -- the attribute to the type of the object. This is allowed for
7170 -- both unconstrained and constrained arrays, since the bounds
7171 -- have no influence on the value of this attribute.
7173 if Id = Attribute_Component_Size then
7174 P_Entity := Etype (P);
7176 -- For First and Last, the prefix is an array object, and we apply
7177 -- the attribute to the type of the array, but we need a constrained
7178 -- type for this, so we use the actual subtype if available.
7180 elsif Id = Attribute_First
7184 Id = Attribute_Length
7187 AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P);
7190 if Present (AS) and then Is_Constrained (AS) then
7193 -- If we have an unconstrained type we cannot fold
7201 -- For Size, give size of object if available, otherwise we
7202 -- cannot fold Size.
7204 elsif Id = Attribute_Size then
7205 if Is_Entity_Name (P)
7206 and then Known_Esize (Entity (P))
7208 Compile_Time_Known_Attribute (N, Esize (Entity (P)));
7216 -- For Alignment, give size of object if available, otherwise we
7217 -- cannot fold Alignment.
7219 elsif Id = Attribute_Alignment then
7220 if Is_Entity_Name (P)
7221 and then Known_Alignment (Entity (P))
7223 Fold_Uint (N, Alignment (Entity (P)), False);
7231 -- For Lock_Free, we apply the attribute to the type of the object.
7232 -- This is allowed since we have already verified that the type is a
7235 elsif Id = Attribute_Lock_Free then
7236 P_Entity := Etype (P);
7238 -- No other attributes for objects are folded
7245 -- Cases where P is not an object. Cannot do anything if P is not the
7246 -- name of an entity.
7248 elsif not Is_Entity_Name (P) then
7252 -- Otherwise get prefix entity
7255 P_Entity := Entity (P);
7258 -- At this stage P_Entity is the entity to which the attribute
7259 -- is to be applied. This is usually simply the entity of the
7260 -- prefix, except in some cases of attributes for objects, where
7261 -- as described above, we apply the attribute to the object type.
7263 -- First foldable possibility is a scalar or array type (RM 4.9(7))
7264 -- that is not generic (generic types are eliminated by RM 4.9(25)).
7265 -- Note we allow non-static non-generic types at this stage as further
7268 if Is_Type (P_Entity)
7269 and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity))
7270 and then (not Is_Generic_Type (P_Entity))
7274 -- Second foldable possibility is an array object (RM 4.9(8))
7276 elsif (Ekind (P_Entity) = E_Variable
7278 Ekind (P_Entity) = E_Constant)
7279 and then Is_Array_Type (Etype (P_Entity))
7280 and then (not Is_Generic_Type (Etype (P_Entity)))
7282 P_Type := Etype (P_Entity);
7284 -- If the entity is an array constant with an unconstrained nominal
7285 -- subtype then get the type from the initial value. If the value has
7286 -- been expanded into assignments, there is no expression and the
7287 -- attribute reference remains dynamic.
7289 -- We could do better here and retrieve the type ???
7291 if Ekind (P_Entity) = E_Constant
7292 and then not Is_Constrained (P_Type)
7294 if No (Constant_Value (P_Entity)) then
7297 P_Type := Etype (Constant_Value (P_Entity));
7301 -- Definite must be folded if the prefix is not a generic type,
7302 -- that is to say if we are within an instantiation. Same processing
7303 -- applies to the GNAT attributes Atomic_Always_Lock_Free,
7304 -- Has_Discriminants, Lock_Free, Type_Class, Has_Tagged_Value, and
7305 -- Unconstrained_Array.
7307 elsif (Id = Attribute_Atomic_Always_Lock_Free
7309 Id = Attribute_Definite
7311 Id = Attribute_Has_Access_Values
7313 Id = Attribute_Has_Discriminants
7315 Id = Attribute_Has_Tagged_Values
7317 Id = Attribute_Lock_Free
7319 Id = Attribute_Type_Class
7321 Id = Attribute_Unconstrained_Array
7323 Id = Attribute_Max_Alignment_For_Allocation)
7324 and then not Is_Generic_Type (P_Entity)
7328 -- We can fold 'Size applied to a type if the size is known (as happens
7329 -- for a size from an attribute definition clause). At this stage, this
7330 -- can happen only for types (e.g. record types) for which the size is
7331 -- always non-static. We exclude generic types from consideration (since
7332 -- they have bogus sizes set within templates).
7334 elsif Id = Attribute_Size
7335 and then Is_Type (P_Entity)
7336 and then (not Is_Generic_Type (P_Entity))
7337 and then Known_Static_RM_Size (P_Entity)
7339 Compile_Time_Known_Attribute (N, RM_Size (P_Entity));
7342 -- We can fold 'Alignment applied to a type if the alignment is known
7343 -- (as happens for an alignment from an attribute definition clause).
7344 -- At this stage, this can happen only for types (e.g. record types) for
7345 -- which the size is always non-static. We exclude generic types from
7346 -- consideration (since they have bogus sizes set within templates).
7348 elsif Id = Attribute_Alignment
7349 and then Is_Type (P_Entity)
7350 and then (not Is_Generic_Type (P_Entity))
7351 and then Known_Alignment (P_Entity)
7353 Compile_Time_Known_Attribute (N, Alignment (P_Entity));
7356 -- If this is an access attribute that is known to fail accessibility
7357 -- check, rewrite accordingly.
7359 elsif Attribute_Name (N) = Name_Access
7360 and then Raises_Constraint_Error (N)
7363 Make_Raise_Program_Error (Loc,
7364 Reason => PE_Accessibility_Check_Failed));
7365 Set_Etype (N, C_Type);
7368 -- No other cases are foldable (they certainly aren't static, and at
7369 -- the moment we don't try to fold any cases other than the ones above).
7376 -- If either attribute or the prefix is Any_Type, then propagate
7377 -- Any_Type to the result and don't do anything else at all.
7379 if P_Type = Any_Type
7380 or else (Present (E1) and then Etype (E1) = Any_Type)
7381 or else (Present (E2) and then Etype (E2) = Any_Type)
7383 Set_Etype (N, Any_Type);
7387 -- Scalar subtype case. We have not yet enforced the static requirement
7388 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
7389 -- of non-static attribute references (e.g. S'Digits for a non-static
7390 -- floating-point type, which we can compute at compile time).
7392 -- Note: this folding of non-static attributes is not simply a case of
7393 -- optimization. For many of the attributes affected, Gigi cannot handle
7394 -- the attribute and depends on the front end having folded them away.
7396 -- Note: although we don't require staticness at this stage, we do set
7397 -- the Static variable to record the staticness, for easy reference by
7398 -- those attributes where it matters (e.g. Succ and Pred), and also to
7399 -- be used to ensure that non-static folded things are not marked as
7400 -- being static (a check that is done right at the end).
7402 P_Root_Type := Root_Type (P_Type);
7403 P_Base_Type := Base_Type (P_Type);
7405 -- If the root type or base type is generic, then we cannot fold. This
7406 -- test is needed because subtypes of generic types are not always
7407 -- marked as being generic themselves (which seems odd???)
7409 if Is_Generic_Type (P_Root_Type)
7410 or else Is_Generic_Type (P_Base_Type)
7415 if Is_Scalar_Type (P_Type) then
7416 Static := Is_OK_Static_Subtype (P_Type);
7418 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
7419 -- since we can't do anything with unconstrained arrays. In addition,
7420 -- only the First, Last and Length attributes are possibly static.
7422 -- Atomic_Always_Lock_Free, Definite, Has_Access_Values,
7423 -- Has_Discriminants, Has_Tagged_Values, Lock_Free, Type_Class, and
7424 -- Unconstrained_Array are again exceptions, because they apply as well
7425 -- to unconstrained types.
7427 -- In addition Component_Size is an exception since it is possibly
7428 -- foldable, even though it is never static, and it does apply to
7429 -- unconstrained arrays. Furthermore, it is essential to fold this
7430 -- in the packed case, since otherwise the value will be incorrect.
7432 elsif Id = Attribute_Atomic_Always_Lock_Free
7434 Id = Attribute_Definite
7436 Id = Attribute_Has_Access_Values
7438 Id = Attribute_Has_Discriminants
7440 Id = Attribute_Has_Tagged_Values
7442 Id = Attribute_Lock_Free
7444 Id = Attribute_Type_Class
7446 Id = Attribute_Unconstrained_Array
7448 Id = Attribute_Component_Size
7452 elsif Id /= Attribute_Max_Alignment_For_Allocation then
7453 if not Is_Constrained (P_Type)
7454 or else (Id /= Attribute_First and then
7455 Id /= Attribute_Last and then
7456 Id /= Attribute_Length)
7462 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
7463 -- scalar case, we hold off on enforcing staticness, since there are
7464 -- cases which we can fold at compile time even though they are not
7465 -- static (e.g. 'Length applied to a static index, even though other
7466 -- non-static indexes make the array type non-static). This is only
7467 -- an optimization, but it falls out essentially free, so why not.
7468 -- Again we compute the variable Static for easy reference later
7469 -- (note that no array attributes are static in Ada 83).
7471 -- We also need to set Static properly for subsequent legality checks
7472 -- which might otherwise accept non-static constants in contexts
7473 -- where they are not legal.
7475 Static := Ada_Version >= Ada_95
7476 and then Statically_Denotes_Entity (P);
7482 N := First_Index (P_Type);
7484 -- The expression is static if the array type is constrained
7485 -- by given bounds, and not by an initial expression. Constant
7486 -- strings are static in any case.
7488 if Root_Type (P_Type) /= Standard_String then
7490 Static and then not Is_Constr_Subt_For_U_Nominal (P_Type);
7493 while Present (N) loop
7494 Static := Static and then Is_Static_Subtype (Etype (N));
7496 -- If however the index type is generic, or derived from
7497 -- one, attributes cannot be folded.
7499 if Is_Generic_Type (Root_Type (Etype (N)))
7500 and then Id /= Attribute_Component_Size
7510 -- Check any expressions that are present. Note that these expressions,
7511 -- depending on the particular attribute type, are either part of the
7512 -- attribute designator, or they are arguments in a case where the
7513 -- attribute reference returns a function. In the latter case, the
7514 -- rule in (RM 4.9(22)) applies and in particular requires the type
7515 -- of the expressions to be scalar in order for the attribute to be
7516 -- considered to be static.
7523 while Present (E) loop
7525 -- If expression is not static, then the attribute reference
7526 -- result certainly cannot be static.
7528 if not Is_Static_Expression (E) then
7532 -- If the result is not known at compile time, or is not of
7533 -- a scalar type, then the result is definitely not static,
7534 -- so we can quit now.
7536 if not Compile_Time_Known_Value (E)
7537 or else not Is_Scalar_Type (Etype (E))
7539 -- An odd special case, if this is a Pos attribute, this
7540 -- is where we need to apply a range check since it does
7541 -- not get done anywhere else.
7543 if Id = Attribute_Pos then
7544 if Is_Integer_Type (Etype (E)) then
7545 Apply_Range_Check (E, Etype (N));
7552 -- If the expression raises a constraint error, then so does
7553 -- the attribute reference. We keep going in this case because
7554 -- we are still interested in whether the attribute reference
7555 -- is static even if it is not static.
7557 elsif Raises_Constraint_Error (E) then
7558 Set_Raises_Constraint_Error (N);
7564 if Raises_Constraint_Error (Prefix (N)) then
7569 -- Deal with the case of a static attribute reference that raises
7570 -- constraint error. The Raises_Constraint_Error flag will already
7571 -- have been set, and the Static flag shows whether the attribute
7572 -- reference is static. In any case we certainly can't fold such an
7573 -- attribute reference.
7575 -- Note that the rewriting of the attribute node with the constraint
7576 -- error node is essential in this case, because otherwise Gigi might
7577 -- blow up on one of the attributes it never expects to see.
7579 -- The constraint_error node must have the type imposed by the context,
7580 -- to avoid spurious errors in the enclosing expression.
7582 if Raises_Constraint_Error (N) then
7584 Make_Raise_Constraint_Error (Sloc (N),
7585 Reason => CE_Range_Check_Failed);
7586 Set_Etype (CE_Node, Etype (N));
7587 Set_Raises_Constraint_Error (CE_Node);
7589 Rewrite (N, Relocate_Node (CE_Node));
7590 Set_Is_Static_Expression (N, Static);
7594 -- At this point we have a potentially foldable attribute reference.
7595 -- If Static is set, then the attribute reference definitely obeys
7596 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
7597 -- folded. If Static is not set, then the attribute may or may not
7598 -- be foldable, and the individual attribute processing routines
7599 -- test Static as required in cases where it makes a difference.
7601 -- In the case where Static is not set, we do know that all the
7602 -- expressions present are at least known at compile time (we assumed
7603 -- above that if this was not the case, then there was no hope of static
7604 -- evaluation). However, we did not require that the bounds of the
7605 -- prefix type be compile time known, let alone static). That's because
7606 -- there are many attributes that can be computed at compile time on
7607 -- non-static subtypes, even though such references are not static
7610 -- For VAX float, the root type is an IEEE type. So make sure to use the
7611 -- base type instead of the root-type for floating point attributes.
7615 -- Attributes related to Ada 2012 iterators (placeholder ???)
7617 when Attribute_Constant_Indexing |
7618 Attribute_Default_Iterator |
7619 Attribute_Implicit_Dereference |
7620 Attribute_Iterator_Element |
7621 Attribute_Iterable |
7622 Attribute_Variable_Indexing => null;
7624 -- Internal attributes used to deal with Ada 2012 delayed aspects.
7625 -- These were already rejected by the parser. Thus they shouldn't
7628 when Internal_Attribute_Id =>
7629 raise Program_Error;
7635 when Attribute_Adjacent =>
7639 (P_Base_Type, Expr_Value_R (E1), Expr_Value_R (E2)),
7646 when Attribute_Aft =>
7647 Fold_Uint (N, Aft_Value (P_Type), True);
7653 when Attribute_Alignment => Alignment_Block : declare
7654 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7657 -- Fold if alignment is set and not otherwise
7659 if Known_Alignment (P_TypeA) then
7660 Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA));
7662 end Alignment_Block;
7668 -- Can only be folded in No_Ast_Handler case
7670 when Attribute_AST_Entry =>
7671 if not Is_AST_Entry (P_Entity) then
7673 New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc));
7678 -----------------------------
7679 -- Atomic_Always_Lock_Free --
7680 -----------------------------
7682 -- Atomic_Always_Lock_Free attribute is a Boolean, thus no need to fold
7685 when Attribute_Atomic_Always_Lock_Free => Atomic_Always_Lock_Free :
7687 V : constant Entity_Id :=
7689 (Support_Atomic_Primitives_On_Target
7690 and then Support_Atomic_Primitives (P_Type));
7693 Rewrite (N, New_Occurrence_Of (V, Loc));
7695 -- Analyze and resolve as boolean. Note that this attribute is a
7696 -- static attribute in GNAT.
7698 Analyze_And_Resolve (N, Standard_Boolean);
7700 end Atomic_Always_Lock_Free;
7706 -- Bit can never be folded
7708 when Attribute_Bit =>
7715 -- Body_version can never be static
7717 when Attribute_Body_Version =>
7724 when Attribute_Ceiling =>
7726 (N, Eval_Fat.Ceiling (P_Base_Type, Expr_Value_R (E1)), Static);
7728 --------------------
7729 -- Component_Size --
7730 --------------------
7732 when Attribute_Component_Size =>
7733 if Known_Static_Component_Size (P_Type) then
7734 Fold_Uint (N, Component_Size (P_Type), False);
7741 when Attribute_Compose =>
7744 Eval_Fat.Compose (P_Base_Type, Expr_Value_R (E1), Expr_Value (E2)),
7751 -- Constrained is never folded for now, there may be cases that
7752 -- could be handled at compile time. To be looked at later.
7754 when Attribute_Constrained =>
7761 when Attribute_Copy_Sign =>
7765 (P_Base_Type, Expr_Value_R (E1), Expr_Value_R (E2)),
7772 when Attribute_Definite =>
7773 Rewrite (N, New_Occurrence_Of (
7774 Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc));
7775 Analyze_And_Resolve (N, Standard_Boolean);
7781 when Attribute_Delta =>
7782 Fold_Ureal (N, Delta_Value (P_Type), True);
7788 when Attribute_Denorm =>
7790 (N, UI_From_Int (Boolean'Pos (Has_Denormals (P_Type))), True);
7792 ---------------------
7793 -- Descriptor_Size --
7794 ---------------------
7796 when Attribute_Descriptor_Size =>
7803 when Attribute_Digits =>
7804 Fold_Uint (N, Digits_Value (P_Type), True);
7810 when Attribute_Emax =>
7812 -- Ada 83 attribute is defined as (RM83 3.5.8)
7814 -- T'Emax = 4 * T'Mantissa
7816 Fold_Uint (N, 4 * Mantissa, True);
7822 when Attribute_Enum_Rep =>
7824 -- For an enumeration type with a non-standard representation use
7825 -- the Enumeration_Rep field of the proper constant. Note that this
7826 -- will not work for types Character/Wide_[Wide-]Character, since no
7827 -- real entities are created for the enumeration literals, but that
7828 -- does not matter since these two types do not have non-standard
7829 -- representations anyway.
7831 if Is_Enumeration_Type (P_Type)
7832 and then Has_Non_Standard_Rep (P_Type)
7834 Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static);
7836 -- For enumeration types with standard representations and all
7837 -- other cases (i.e. all integer and modular types), Enum_Rep
7838 -- is equivalent to Pos.
7841 Fold_Uint (N, Expr_Value (E1), Static);
7848 when Attribute_Enum_Val => Enum_Val : declare
7852 -- We have something like Enum_Type'Enum_Val (23), so search for a
7853 -- corresponding value in the list of Enum_Rep values for the type.
7855 Lit := First_Literal (P_Base_Type);
7857 if Enumeration_Rep (Lit) = Expr_Value (E1) then
7858 Fold_Uint (N, Enumeration_Pos (Lit), Static);
7865 Apply_Compile_Time_Constraint_Error
7866 (N, "no representation value matches",
7867 CE_Range_Check_Failed,
7868 Warn => not Static);
7878 when Attribute_Epsilon =>
7880 -- Ada 83 attribute is defined as (RM83 3.5.8)
7882 -- T'Epsilon = 2.0**(1 - T'Mantissa)
7884 Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True);
7890 when Attribute_Exponent =>
7892 Eval_Fat.Exponent (P_Base_Type, Expr_Value_R (E1)), Static);
7898 when Attribute_First => First_Attr :
7902 if Compile_Time_Known_Value (Lo_Bound) then
7903 if Is_Real_Type (P_Type) then
7904 Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static);
7906 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
7909 -- Replace VAX Float_Type'First with a reference to the temporary
7910 -- which represents the low bound of the type. This transformation
7911 -- is needed since the back end cannot evaluate 'First on VAX.
7913 elsif Is_VAX_Float (P_Type)
7914 and then Nkind (Lo_Bound) = N_Identifier
7916 Rewrite (N, New_Occurrence_Of (Entity (Lo_Bound), Sloc (N)));
7920 Check_Concurrent_Discriminant (Lo_Bound);
7928 when Attribute_First_Valid => First_Valid :
7930 if Has_Predicates (P_Type)
7931 and then Present (Static_Predicate (P_Type))
7934 FirstN : constant Node_Id := First (Static_Predicate (P_Type));
7936 if Nkind (FirstN) = N_Range then
7937 Fold_Uint (N, Expr_Value (Low_Bound (FirstN)), Static);
7939 Fold_Uint (N, Expr_Value (FirstN), Static);
7945 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
7953 when Attribute_Fixed_Value =>
7960 when Attribute_Floor =>
7962 (N, Eval_Fat.Floor (P_Base_Type, Expr_Value_R (E1)), Static);
7968 when Attribute_Fore =>
7969 if Compile_Time_Known_Bounds (P_Type) then
7970 Fold_Uint (N, UI_From_Int (Fore_Value), Static);
7977 when Attribute_Fraction =>
7979 (N, Eval_Fat.Fraction (P_Base_Type, Expr_Value_R (E1)), Static);
7981 -----------------------
7982 -- Has_Access_Values --
7983 -----------------------
7985 when Attribute_Has_Access_Values =>
7986 Rewrite (N, New_Occurrence_Of
7987 (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc));
7988 Analyze_And_Resolve (N, Standard_Boolean);
7990 -----------------------
7991 -- Has_Discriminants --
7992 -----------------------
7994 when Attribute_Has_Discriminants =>
7995 Rewrite (N, New_Occurrence_Of (
7996 Boolean_Literals (Has_Discriminants (P_Entity)), Loc));
7997 Analyze_And_Resolve (N, Standard_Boolean);
7999 ----------------------
8000 -- Has_Same_Storage --
8001 ----------------------
8003 when Attribute_Has_Same_Storage =>
8006 -----------------------
8007 -- Has_Tagged_Values --
8008 -----------------------
8010 when Attribute_Has_Tagged_Values =>
8011 Rewrite (N, New_Occurrence_Of
8012 (Boolean_Literals (Has_Tagged_Component (P_Root_Type)), Loc));
8013 Analyze_And_Resolve (N, Standard_Boolean);
8019 when Attribute_Identity =>
8026 -- Image is a scalar attribute, but is never static, because it is
8027 -- not a static function (having a non-scalar argument (RM 4.9(22))
8028 -- However, we can constant-fold the image of an enumeration literal
8029 -- if names are available.
8031 when Attribute_Image =>
8032 if Is_Entity_Name (E1)
8033 and then Ekind (Entity (E1)) = E_Enumeration_Literal
8034 and then not Discard_Names (First_Subtype (Etype (E1)))
8035 and then not Global_Discard_Names
8038 Lit : constant Entity_Id := Entity (E1);
8042 Get_Unqualified_Decoded_Name_String (Chars (Lit));
8043 Set_Casing (All_Upper_Case);
8044 Store_String_Chars (Name_Buffer (1 .. Name_Len));
8046 Rewrite (N, Make_String_Literal (Loc, Strval => Str));
8047 Analyze_And_Resolve (N, Standard_String);
8048 Set_Is_Static_Expression (N, False);
8056 -- Img is a scalar attribute, but is never static, because it is
8057 -- not a static function (having a non-scalar argument (RM 4.9(22))
8059 when Attribute_Img =>
8066 -- We never try to fold Integer_Value (though perhaps we could???)
8068 when Attribute_Integer_Value =>
8075 -- Invalid_Value is a scalar attribute that is never static, because
8076 -- the value is by design out of range.
8078 when Attribute_Invalid_Value =>
8085 when Attribute_Large =>
8087 -- For fixed-point, we use the identity:
8089 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
8091 if Is_Fixed_Point_Type (P_Type) then
8093 Make_Op_Multiply (Loc,
8095 Make_Op_Subtract (Loc,
8099 Make_Real_Literal (Loc, Ureal_2),
8101 Make_Attribute_Reference (Loc,
8103 Attribute_Name => Name_Mantissa)),
8104 Right_Opnd => Make_Real_Literal (Loc, Ureal_1)),
8107 Make_Real_Literal (Loc, Small_Value (Entity (P)))));
8109 Analyze_And_Resolve (N, C_Type);
8111 -- Floating-point (Ada 83 compatibility)
8114 -- Ada 83 attribute is defined as (RM83 3.5.8)
8116 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
8120 -- T'Emax = 4 * T'Mantissa
8124 Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)),
8132 when Attribute_Lock_Free => Lock_Free : declare
8133 V : constant Entity_Id := Boolean_Literals (Uses_Lock_Free (P_Type));
8136 Rewrite (N, New_Occurrence_Of (V, Loc));
8138 -- Analyze and resolve as boolean. Note that this attribute is a
8139 -- static attribute in GNAT.
8141 Analyze_And_Resolve (N, Standard_Boolean);
8149 when Attribute_Last => Last_Attr :
8153 if Compile_Time_Known_Value (Hi_Bound) then
8154 if Is_Real_Type (P_Type) then
8155 Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static);
8157 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
8160 -- Replace VAX Float_Type'Last with a reference to the temporary
8161 -- which represents the high bound of the type. This transformation
8162 -- is needed since the back end cannot evaluate 'Last on VAX.
8164 elsif Is_VAX_Float (P_Type)
8165 and then Nkind (Hi_Bound) = N_Identifier
8167 Rewrite (N, New_Occurrence_Of (Entity (Hi_Bound), Sloc (N)));
8171 Check_Concurrent_Discriminant (Hi_Bound);
8179 when Attribute_Last_Valid => Last_Valid :
8181 if Has_Predicates (P_Type)
8182 and then Present (Static_Predicate (P_Type))
8185 LastN : constant Node_Id := Last (Static_Predicate (P_Type));
8187 if Nkind (LastN) = N_Range then
8188 Fold_Uint (N, Expr_Value (High_Bound (LastN)), Static);
8190 Fold_Uint (N, Expr_Value (LastN), Static);
8196 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
8204 when Attribute_Leading_Part =>
8207 Eval_Fat.Leading_Part
8208 (P_Base_Type, Expr_Value_R (E1), Expr_Value (E2)),
8215 when Attribute_Length => Length : declare
8219 -- If any index type is a formal type, or derived from one, the
8220 -- bounds are not static. Treating them as static can produce
8221 -- spurious warnings or improper constant folding.
8223 Ind := First_Index (P_Type);
8224 while Present (Ind) loop
8225 if Is_Generic_Type (Root_Type (Etype (Ind))) then
8234 -- For two compile time values, we can compute length
8236 if Compile_Time_Known_Value (Lo_Bound)
8237 and then Compile_Time_Known_Value (Hi_Bound)
8240 UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))),
8244 -- One more case is where Hi_Bound and Lo_Bound are compile-time
8245 -- comparable, and we can figure out the difference between them.
8248 Diff : aliased Uint;
8252 Compile_Time_Compare
8253 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
8256 Fold_Uint (N, Uint_1, False);
8259 Fold_Uint (N, Uint_0, False);
8262 if Diff /= No_Uint then
8263 Fold_Uint (N, Diff + 1, False);
8276 -- Loop_Entry acts as an alias of a constant initialized to the prefix
8277 -- of the said attribute at the point of entry into the related loop. As
8278 -- such, the attribute reference does not need to be evaluated because
8279 -- the prefix is the one that is evaluted.
8281 when Attribute_Loop_Entry =>
8288 when Attribute_Machine =>
8292 (P_Base_Type, Expr_Value_R (E1), Eval_Fat.Round, N),
8299 when Attribute_Machine_Emax =>
8300 Fold_Uint (N, Machine_Emax_Value (P_Type), Static);
8306 when Attribute_Machine_Emin =>
8307 Fold_Uint (N, Machine_Emin_Value (P_Type), Static);
8309 ----------------------
8310 -- Machine_Mantissa --
8311 ----------------------
8313 when Attribute_Machine_Mantissa =>
8314 Fold_Uint (N, Machine_Mantissa_Value (P_Type), Static);
8316 -----------------------
8317 -- Machine_Overflows --
8318 -----------------------
8320 when Attribute_Machine_Overflows =>
8322 -- Always true for fixed-point
8324 if Is_Fixed_Point_Type (P_Type) then
8325 Fold_Uint (N, True_Value, True);
8327 -- Floating point case
8331 UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)),
8339 when Attribute_Machine_Radix =>
8340 if Is_Fixed_Point_Type (P_Type) then
8341 if Is_Decimal_Fixed_Point_Type (P_Type)
8342 and then Machine_Radix_10 (P_Type)
8344 Fold_Uint (N, Uint_10, True);
8346 Fold_Uint (N, Uint_2, True);
8349 -- All floating-point type always have radix 2
8352 Fold_Uint (N, Uint_2, True);
8355 ----------------------
8356 -- Machine_Rounding --
8357 ----------------------
8359 -- Note: for the folding case, it is fine to treat Machine_Rounding
8360 -- exactly the same way as Rounding, since this is one of the allowed
8361 -- behaviors, and performance is not an issue here. It might be a bit
8362 -- better to give the same result as it would give at run time, even
8363 -- though the non-determinism is certainly permitted.
8365 when Attribute_Machine_Rounding =>
8367 (N, Eval_Fat.Rounding (P_Base_Type, Expr_Value_R (E1)), Static);
8369 --------------------
8370 -- Machine_Rounds --
8371 --------------------
8373 when Attribute_Machine_Rounds =>
8375 -- Always False for fixed-point
8377 if Is_Fixed_Point_Type (P_Type) then
8378 Fold_Uint (N, False_Value, True);
8380 -- Else yield proper floating-point result
8384 (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True);
8391 -- Note: Machine_Size is identical to Object_Size
8393 when Attribute_Machine_Size => Machine_Size : declare
8394 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
8397 if Known_Esize (P_TypeA) then
8398 Fold_Uint (N, Esize (P_TypeA), True);
8406 when Attribute_Mantissa =>
8408 -- Fixed-point mantissa
8410 if Is_Fixed_Point_Type (P_Type) then
8412 -- Compile time foldable case
8414 if Compile_Time_Known_Value (Type_Low_Bound (P_Type))
8416 Compile_Time_Known_Value (Type_High_Bound (P_Type))
8418 -- The calculation of the obsolete Ada 83 attribute Mantissa
8419 -- is annoying, because of AI00143, quoted here:
8421 -- !question 84-01-10
8423 -- Consider the model numbers for F:
8425 -- type F is delta 1.0 range -7.0 .. 8.0;
8427 -- The wording requires that F'MANTISSA be the SMALLEST
8428 -- integer number for which each bound of the specified
8429 -- range is either a model number or lies at most small
8430 -- distant from a model number. This means F'MANTISSA
8431 -- is required to be 3 since the range -7.0 .. 7.0 fits
8432 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
8433 -- number, namely, 7. Is this analysis correct? Note that
8434 -- this implies the upper bound of the range is not
8435 -- represented as a model number.
8437 -- !response 84-03-17
8439 -- The analysis is correct. The upper and lower bounds for
8440 -- a fixed point type can lie outside the range of model
8451 LBound := Expr_Value_R (Type_Low_Bound (P_Type));
8452 UBound := Expr_Value_R (Type_High_Bound (P_Type));
8453 Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound));
8454 Max_Man := UR_Trunc (Bound / Small_Value (P_Type));
8456 -- If the Bound is exactly a model number, i.e. a multiple
8457 -- of Small, then we back it off by one to get the integer
8458 -- value that must be representable.
8460 if Small_Value (P_Type) * Max_Man = Bound then
8461 Max_Man := Max_Man - 1;
8464 -- Now find corresponding size = Mantissa value
8467 while 2 ** Siz < Max_Man loop
8471 Fold_Uint (N, Siz, True);
8475 -- The case of dynamic bounds cannot be evaluated at compile
8476 -- time. Instead we use a runtime routine (see Exp_Attr).
8481 -- Floating-point Mantissa
8484 Fold_Uint (N, Mantissa, True);
8491 when Attribute_Max => Max :
8493 if Is_Real_Type (P_Type) then
8495 (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
8497 Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static);
8501 ----------------------------------
8502 -- Max_Alignment_For_Allocation --
8503 ----------------------------------
8505 -- Max_Alignment_For_Allocation is usually the Alignment. However,
8506 -- arrays are allocated with dope, so we need to take into account both
8507 -- the alignment of the array, which comes from the component alignment,
8508 -- and the alignment of the dope. Also, if the alignment is unknown, we
8509 -- use the max (it's OK to be pessimistic).
8511 when Attribute_Max_Alignment_For_Allocation =>
8513 A : Uint := UI_From_Int (Ttypes.Maximum_Alignment);
8515 if Known_Alignment (P_Type) and then
8516 (not Is_Array_Type (P_Type) or else Alignment (P_Type) > A)
8518 A := Alignment (P_Type);
8521 Fold_Uint (N, A, Static);
8524 ----------------------------------
8525 -- Max_Size_In_Storage_Elements --
8526 ----------------------------------
8528 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
8529 -- Storage_Unit boundary. We can fold any cases for which the size
8530 -- is known by the front end.
8532 when Attribute_Max_Size_In_Storage_Elements =>
8533 if Known_Esize (P_Type) then
8535 (Esize (P_Type) + System_Storage_Unit - 1) /
8536 System_Storage_Unit,
8540 --------------------
8541 -- Mechanism_Code --
8542 --------------------
8544 when Attribute_Mechanism_Code =>
8548 Mech : Mechanism_Type;
8552 Mech := Mechanism (P_Entity);
8555 Val := UI_To_Int (Expr_Value (E1));
8557 Formal := First_Formal (P_Entity);
8558 for J in 1 .. Val - 1 loop
8559 Next_Formal (Formal);
8561 Mech := Mechanism (Formal);
8565 Fold_Uint (N, UI_From_Int (Int (-Mech)), True);
8573 when Attribute_Min => Min :
8575 if Is_Real_Type (P_Type) then
8577 (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
8580 (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static);
8588 when Attribute_Mod =>
8590 (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static);
8596 when Attribute_Model =>
8598 (N, Eval_Fat.Model (P_Base_Type, Expr_Value_R (E1)), Static);
8604 when Attribute_Model_Emin =>
8605 Fold_Uint (N, Model_Emin_Value (P_Base_Type), Static);
8611 when Attribute_Model_Epsilon =>
8612 Fold_Ureal (N, Model_Epsilon_Value (P_Base_Type), Static);
8614 --------------------
8615 -- Model_Mantissa --
8616 --------------------
8618 when Attribute_Model_Mantissa =>
8619 Fold_Uint (N, Model_Mantissa_Value (P_Base_Type), Static);
8625 when Attribute_Model_Small =>
8626 Fold_Ureal (N, Model_Small_Value (P_Base_Type), Static);
8632 when Attribute_Modulus =>
8633 Fold_Uint (N, Modulus (P_Type), True);
8635 --------------------
8636 -- Null_Parameter --
8637 --------------------
8639 -- Cannot fold, we know the value sort of, but the whole point is
8640 -- that there is no way to talk about this imaginary value except
8641 -- by using the attribute, so we leave it the way it is.
8643 when Attribute_Null_Parameter =>
8650 -- The Object_Size attribute for a type returns the Esize of the
8651 -- type and can be folded if this value is known.
8653 when Attribute_Object_Size => Object_Size : declare
8654 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
8657 if Known_Esize (P_TypeA) then
8658 Fold_Uint (N, Esize (P_TypeA), True);
8662 ----------------------
8663 -- Overlaps_Storage --
8664 ----------------------
8666 when Attribute_Overlaps_Storage =>
8669 -------------------------
8670 -- Passed_By_Reference --
8671 -------------------------
8673 -- Scalar types are never passed by reference
8675 when Attribute_Passed_By_Reference =>
8676 Fold_Uint (N, False_Value, True);
8682 when Attribute_Pos =>
8683 Fold_Uint (N, Expr_Value (E1), True);
8689 when Attribute_Pred => Pred :
8691 -- Floating-point case
8693 if Is_Floating_Point_Type (P_Type) then
8695 (N, Eval_Fat.Pred (P_Base_Type, Expr_Value_R (E1)), Static);
8699 elsif Is_Fixed_Point_Type (P_Type) then
8701 (N, Expr_Value_R (E1) - Small_Value (P_Type), True);
8703 -- Modular integer case (wraps)
8705 elsif Is_Modular_Integer_Type (P_Type) then
8706 Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static);
8708 -- Other scalar cases
8711 pragma Assert (Is_Scalar_Type (P_Type));
8713 if Is_Enumeration_Type (P_Type)
8714 and then Expr_Value (E1) =
8715 Expr_Value (Type_Low_Bound (P_Base_Type))
8717 Apply_Compile_Time_Constraint_Error
8718 (N, "Pred of `&''First`",
8719 CE_Overflow_Check_Failed,
8721 Warn => not Static);
8727 Fold_Uint (N, Expr_Value (E1) - 1, Static);
8735 -- No processing required, because by this stage, Range has been
8736 -- replaced by First .. Last, so this branch can never be taken.
8738 when Attribute_Range =>
8739 raise Program_Error;
8745 when Attribute_Range_Length =>
8748 -- Can fold if both bounds are compile time known
8750 if Compile_Time_Known_Value (Hi_Bound)
8751 and then Compile_Time_Known_Value (Lo_Bound)
8755 (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1),
8759 -- One more case is where Hi_Bound and Lo_Bound are compile-time
8760 -- comparable, and we can figure out the difference between them.
8763 Diff : aliased Uint;
8767 Compile_Time_Compare
8768 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
8771 Fold_Uint (N, Uint_1, False);
8774 Fold_Uint (N, Uint_0, False);
8777 if Diff /= No_Uint then
8778 Fold_Uint (N, Diff + 1, False);
8790 when Attribute_Ref =>
8791 Fold_Uint (N, Expr_Value (E1), True);
8797 when Attribute_Remainder => Remainder : declare
8798 X : constant Ureal := Expr_Value_R (E1);
8799 Y : constant Ureal := Expr_Value_R (E2);
8802 if UR_Is_Zero (Y) then
8803 Apply_Compile_Time_Constraint_Error
8804 (N, "division by zero in Remainder",
8805 CE_Overflow_Check_Failed,
8806 Warn => not Static);
8812 Fold_Ureal (N, Eval_Fat.Remainder (P_Base_Type, X, Y), Static);
8819 when Attribute_Restriction_Set => Restriction_Set : declare
8821 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
8822 Set_Is_Static_Expression (N);
8823 end Restriction_Set;
8829 when Attribute_Round => Round :
8835 -- First we get the (exact result) in units of small
8837 Sr := Expr_Value_R (E1) / Small_Value (C_Type);
8839 -- Now round that exactly to an integer
8841 Si := UR_To_Uint (Sr);
8843 -- Finally the result is obtained by converting back to real
8845 Fold_Ureal (N, Si * Small_Value (C_Type), Static);
8852 when Attribute_Rounding =>
8854 (N, Eval_Fat.Rounding (P_Base_Type, Expr_Value_R (E1)), Static);
8860 when Attribute_Safe_Emax =>
8861 Fold_Uint (N, Safe_Emax_Value (P_Type), Static);
8867 when Attribute_Safe_First =>
8868 Fold_Ureal (N, Safe_First_Value (P_Type), Static);
8874 when Attribute_Safe_Large =>
8875 if Is_Fixed_Point_Type (P_Type) then
8877 (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static);
8879 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
8886 when Attribute_Safe_Last =>
8887 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
8893 when Attribute_Safe_Small =>
8895 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
8896 -- for fixed-point, since is the same as Small, but we implement
8897 -- it for backwards compatibility.
8899 if Is_Fixed_Point_Type (P_Type) then
8900 Fold_Ureal (N, Small_Value (P_Type), Static);
8902 -- Ada 83 Safe_Small for floating-point cases
8905 Fold_Ureal (N, Model_Small_Value (P_Type), Static);
8912 when Attribute_Scale =>
8913 Fold_Uint (N, Scale_Value (P_Type), True);
8919 when Attribute_Scaling =>
8923 (P_Base_Type, Expr_Value_R (E1), Expr_Value (E2)),
8930 when Attribute_Signed_Zeros =>
8932 (N, UI_From_Int (Boolean'Pos (Has_Signed_Zeros (P_Type))), Static);
8938 -- Size attribute returns the RM size. All scalar types can be folded,
8939 -- as well as any types for which the size is known by the front end,
8940 -- including any type for which a size attribute is specified.
8942 when Attribute_Size | Attribute_VADS_Size => Size : declare
8943 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
8946 if RM_Size (P_TypeA) /= Uint_0 then
8950 if Id = Attribute_VADS_Size or else Use_VADS_Size then
8952 S : constant Node_Id := Size_Clause (P_TypeA);
8955 -- If a size clause applies, then use the size from it.
8956 -- This is one of the rare cases where we can use the
8957 -- Size_Clause field for a subtype when Has_Size_Clause
8958 -- is False. Consider:
8960 -- type x is range 1 .. 64;
8961 -- for x'size use 12;
8962 -- subtype y is x range 0 .. 3;
8964 -- Here y has a size clause inherited from x, but normally
8965 -- it does not apply, and y'size is 2. However, y'VADS_Size
8966 -- is indeed 12 and not 2.
8969 and then Is_OK_Static_Expression (Expression (S))
8971 Fold_Uint (N, Expr_Value (Expression (S)), True);
8973 -- If no size is specified, then we simply use the object
8974 -- size in the VADS_Size case (e.g. Natural'Size is equal
8975 -- to Integer'Size, not one less).
8978 Fold_Uint (N, Esize (P_TypeA), True);
8982 -- Normal case (Size) in which case we want the RM_Size
8987 Static and then Is_Discrete_Type (P_TypeA));
8996 when Attribute_Small =>
8998 -- The floating-point case is present only for Ada 83 compatibility.
8999 -- Note that strictly this is an illegal addition, since we are
9000 -- extending an Ada 95 defined attribute, but we anticipate an
9001 -- ARG ruling that will permit this.
9003 if Is_Floating_Point_Type (P_Type) then
9005 -- Ada 83 attribute is defined as (RM83 3.5.8)
9007 -- T'Small = 2.0**(-T'Emax - 1)
9011 -- T'Emax = 4 * T'Mantissa
9013 Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static);
9015 -- Normal Ada 95 fixed-point case
9018 Fold_Ureal (N, Small_Value (P_Type), True);
9025 when Attribute_Stream_Size =>
9032 when Attribute_Succ => Succ :
9034 -- Floating-point case
9036 if Is_Floating_Point_Type (P_Type) then
9038 (N, Eval_Fat.Succ (P_Base_Type, Expr_Value_R (E1)), Static);
9042 elsif Is_Fixed_Point_Type (P_Type) then
9043 Fold_Ureal (N, Expr_Value_R (E1) + Small_Value (P_Type), Static);
9045 -- Modular integer case (wraps)
9047 elsif Is_Modular_Integer_Type (P_Type) then
9048 Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static);
9050 -- Other scalar cases
9053 pragma Assert (Is_Scalar_Type (P_Type));
9055 if Is_Enumeration_Type (P_Type)
9056 and then Expr_Value (E1) =
9057 Expr_Value (Type_High_Bound (P_Base_Type))
9059 Apply_Compile_Time_Constraint_Error
9060 (N, "Succ of `&''Last`",
9061 CE_Overflow_Check_Failed,
9063 Warn => not Static);
9068 Fold_Uint (N, Expr_Value (E1) + 1, Static);
9077 when Attribute_Truncation =>
9080 Eval_Fat.Truncation (P_Base_Type, Expr_Value_R (E1)),
9087 when Attribute_Type_Class => Type_Class : declare
9088 Typ : constant Entity_Id := Underlying_Type (P_Base_Type);
9092 if Is_Descendent_Of_Address (Typ) then
9093 Id := RE_Type_Class_Address;
9095 elsif Is_Enumeration_Type (Typ) then
9096 Id := RE_Type_Class_Enumeration;
9098 elsif Is_Integer_Type (Typ) then
9099 Id := RE_Type_Class_Integer;
9101 elsif Is_Fixed_Point_Type (Typ) then
9102 Id := RE_Type_Class_Fixed_Point;
9104 elsif Is_Floating_Point_Type (Typ) then
9105 Id := RE_Type_Class_Floating_Point;
9107 elsif Is_Array_Type (Typ) then
9108 Id := RE_Type_Class_Array;
9110 elsif Is_Record_Type (Typ) then
9111 Id := RE_Type_Class_Record;
9113 elsif Is_Access_Type (Typ) then
9114 Id := RE_Type_Class_Access;
9116 elsif Is_Enumeration_Type (Typ) then
9117 Id := RE_Type_Class_Enumeration;
9119 elsif Is_Task_Type (Typ) then
9120 Id := RE_Type_Class_Task;
9122 -- We treat protected types like task types. It would make more
9123 -- sense to have another enumeration value, but after all the
9124 -- whole point of this feature is to be exactly DEC compatible,
9125 -- and changing the type Type_Class would not meet this requirement.
9127 elsif Is_Protected_Type (Typ) then
9128 Id := RE_Type_Class_Task;
9130 -- Not clear if there are any other possibilities, but if there
9131 -- are, then we will treat them as the address case.
9134 Id := RE_Type_Class_Address;
9137 Rewrite (N, New_Occurrence_Of (RTE (Id), Loc));
9140 -----------------------
9141 -- Unbiased_Rounding --
9142 -----------------------
9144 when Attribute_Unbiased_Rounding =>
9147 Eval_Fat.Unbiased_Rounding (P_Base_Type, Expr_Value_R (E1)),
9150 -------------------------
9151 -- Unconstrained_Array --
9152 -------------------------
9154 when Attribute_Unconstrained_Array => Unconstrained_Array : declare
9155 Typ : constant Entity_Id := Underlying_Type (P_Type);
9158 Rewrite (N, New_Occurrence_Of (
9160 Is_Array_Type (P_Type)
9161 and then not Is_Constrained (Typ)), Loc));
9163 -- Analyze and resolve as boolean, note that this attribute is
9164 -- a static attribute in GNAT.
9166 Analyze_And_Resolve (N, Standard_Boolean);
9168 end Unconstrained_Array;
9170 -- Attribute Update is never static
9172 when Attribute_Update =>
9179 -- Processing is shared with Size
9185 when Attribute_Val => Val :
9187 if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type))
9189 Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type))
9191 Apply_Compile_Time_Constraint_Error
9192 (N, "Val expression out of range",
9193 CE_Range_Check_Failed,
9194 Warn => not Static);
9200 Fold_Uint (N, Expr_Value (E1), Static);
9208 -- The Value_Size attribute for a type returns the RM size of the
9209 -- type. This an always be folded for scalar types, and can also
9210 -- be folded for non-scalar types if the size is set.
9212 when Attribute_Value_Size => Value_Size : declare
9213 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
9215 if RM_Size (P_TypeA) /= Uint_0 then
9216 Fold_Uint (N, RM_Size (P_TypeA), True);
9224 -- Version can never be static
9226 when Attribute_Version =>
9233 -- Wide_Image is a scalar attribute, but is never static, because it
9234 -- is not a static function (having a non-scalar argument (RM 4.9(22))
9236 when Attribute_Wide_Image =>
9239 ---------------------
9240 -- Wide_Wide_Image --
9241 ---------------------
9243 -- Wide_Wide_Image is a scalar attribute but is never static, because it
9244 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
9246 when Attribute_Wide_Wide_Image =>
9249 ---------------------
9250 -- Wide_Wide_Width --
9251 ---------------------
9253 -- Processing for Wide_Wide_Width is combined with Width
9259 -- Processing for Wide_Width is combined with Width
9265 -- This processing also handles the case of Wide_[Wide_]Width
9267 when Attribute_Width |
9268 Attribute_Wide_Width |
9269 Attribute_Wide_Wide_Width => Width :
9271 if Compile_Time_Known_Bounds (P_Type) then
9273 -- Floating-point types
9275 if Is_Floating_Point_Type (P_Type) then
9277 -- Width is zero for a null range (RM 3.5 (38))
9279 if Expr_Value_R (Type_High_Bound (P_Type)) <
9280 Expr_Value_R (Type_Low_Bound (P_Type))
9282 Fold_Uint (N, Uint_0, True);
9285 -- For floating-point, we have +N.dddE+nnn where length
9286 -- of ddd is determined by type'Digits - 1, but is one
9287 -- if Digits is one (RM 3.5 (33)).
9289 -- nnn is set to 2 for Short_Float and Float (32 bit
9290 -- floats), and 3 for Long_Float and Long_Long_Float.
9291 -- For machines where Long_Long_Float is the IEEE
9292 -- extended precision type, the exponent takes 4 digits.
9296 Int'Max (2, UI_To_Int (Digits_Value (P_Type)));
9299 if Esize (P_Type) <= 32 then
9301 elsif Esize (P_Type) = 64 then
9307 Fold_Uint (N, UI_From_Int (Len), True);
9311 -- Fixed-point types
9313 elsif Is_Fixed_Point_Type (P_Type) then
9315 -- Width is zero for a null range (RM 3.5 (38))
9317 if Expr_Value (Type_High_Bound (P_Type)) <
9318 Expr_Value (Type_Low_Bound (P_Type))
9320 Fold_Uint (N, Uint_0, True);
9322 -- The non-null case depends on the specific real type
9325 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
9328 (N, UI_From_Int (Fore_Value + 1) + Aft_Value (P_Type),
9336 R : constant Entity_Id := Root_Type (P_Type);
9337 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
9338 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
9351 -- Width for types derived from Standard.Character
9352 -- and Standard.Wide_[Wide_]Character.
9354 elsif Is_Standard_Character_Type (P_Type) then
9357 -- Set W larger if needed
9359 for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop
9361 -- All wide characters look like Hex_hhhhhhhh
9365 -- No need to compute this more than once
9370 C := Character'Val (J);
9372 -- Test for all cases where Character'Image
9373 -- yields an image that is longer than three
9374 -- characters. First the cases of Reserved_xxx
9375 -- names (length = 12).
9378 when Reserved_128 | Reserved_129 |
9379 Reserved_132 | Reserved_153
9382 when BS | HT | LF | VT | FF | CR |
9383 SO | SI | EM | FS | GS | RS |
9384 US | RI | MW | ST | PM
9387 when NUL | SOH | STX | ETX | EOT |
9388 ENQ | ACK | BEL | DLE | DC1 |
9389 DC2 | DC3 | DC4 | NAK | SYN |
9390 ETB | CAN | SUB | ESC | DEL |
9391 BPH | NBH | NEL | SSA | ESA |
9392 HTS | HTJ | VTS | PLD | PLU |
9393 SS2 | SS3 | DCS | PU1 | PU2 |
9394 STS | CCH | SPA | EPA | SOS |
9395 SCI | CSI | OSC | APC
9398 when Space .. Tilde |
9399 No_Break_Space .. LC_Y_Diaeresis
9401 -- Special case of soft hyphen in Ada 2005
9403 if C = Character'Val (16#AD#)
9404 and then Ada_Version >= Ada_2005
9412 W := Int'Max (W, Wt);
9416 -- Width for types derived from Standard.Boolean
9418 elsif R = Standard_Boolean then
9425 -- Width for integer types
9427 elsif Is_Integer_Type (P_Type) then
9428 T := UI_Max (abs Lo, abs Hi);
9436 -- User declared enum type with discard names
9438 elsif Discard_Names (R) then
9440 -- If range is null, result is zero, that has already
9441 -- been dealt with, so what we need is the power of ten
9442 -- that accomodates the Pos of the largest value, which
9443 -- is the high bound of the range + one for the space.
9452 -- Only remaining possibility is user declared enum type
9453 -- with normal case of Discard_Names not active.
9456 pragma Assert (Is_Enumeration_Type (P_Type));
9459 L := First_Literal (P_Type);
9460 while Present (L) loop
9462 -- Only pay attention to in range characters
9464 if Lo <= Enumeration_Pos (L)
9465 and then Enumeration_Pos (L) <= Hi
9467 -- For Width case, use decoded name
9469 if Id = Attribute_Width then
9470 Get_Decoded_Name_String (Chars (L));
9471 Wt := Nat (Name_Len);
9473 -- For Wide_[Wide_]Width, use encoded name, and
9474 -- then adjust for the encoding.
9477 Get_Name_String (Chars (L));
9479 -- Character literals are always of length 3
9481 if Name_Buffer (1) = 'Q' then
9484 -- Otherwise loop to adjust for upper/wide chars
9487 Wt := Nat (Name_Len);
9489 for J in 1 .. Name_Len loop
9490 if Name_Buffer (J) = 'U' then
9492 elsif Name_Buffer (J) = 'W' then
9499 W := Int'Max (W, Wt);
9506 Fold_Uint (N, UI_From_Int (W), True);
9512 -- The following attributes denote functions that cannot be folded
9514 when Attribute_From_Any |
9516 Attribute_TypeCode =>
9519 -- The following attributes can never be folded, and furthermore we
9520 -- should not even have entered the case statement for any of these.
9521 -- Note that in some cases, the values have already been folded as
9522 -- a result of the processing in Analyze_Attribute.
9524 when Attribute_Abort_Signal |
9527 Attribute_Address_Size |
9528 Attribute_Asm_Input |
9529 Attribute_Asm_Output |
9531 Attribute_Bit_Order |
9532 Attribute_Bit_Position |
9533 Attribute_Callable |
9536 Attribute_Code_Address |
9537 Attribute_Compiler_Version |
9539 Attribute_Default_Bit_Order |
9540 Attribute_Elaborated |
9541 Attribute_Elab_Body |
9542 Attribute_Elab_Spec |
9543 Attribute_Elab_Subp_Body |
9545 Attribute_External_Tag |
9546 Attribute_Fast_Math |
9547 Attribute_First_Bit |
9549 Attribute_Last_Bit |
9550 Attribute_Library_Level |
9551 Attribute_Maximum_Alignment |
9554 Attribute_Partition_ID |
9555 Attribute_Pool_Address |
9556 Attribute_Position |
9557 Attribute_Priority |
9560 Attribute_Scalar_Storage_Order |
9561 Attribute_Simple_Storage_Pool |
9562 Attribute_Storage_Pool |
9563 Attribute_Storage_Size |
9564 Attribute_Storage_Unit |
9565 Attribute_Stub_Type |
9566 Attribute_System_Allocator_Alignment |
9568 Attribute_Target_Name |
9569 Attribute_Terminated |
9570 Attribute_To_Address |
9571 Attribute_Type_Key |
9572 Attribute_UET_Address |
9573 Attribute_Unchecked_Access |
9574 Attribute_Universal_Literal_String |
9575 Attribute_Unrestricted_Access |
9577 Attribute_Valid_Scalars |
9579 Attribute_Wchar_T_Size |
9580 Attribute_Wide_Value |
9581 Attribute_Wide_Wide_Value |
9582 Attribute_Word_Size |
9585 raise Program_Error;
9588 -- At the end of the case, one more check. If we did a static evaluation
9589 -- so that the result is now a literal, then set Is_Static_Expression
9590 -- in the constant only if the prefix type is a static subtype. For
9591 -- non-static subtypes, the folding is still OK, but not static.
9593 -- An exception is the GNAT attribute Constrained_Array which is
9594 -- defined to be a static attribute in all cases.
9596 if Nkind_In (N, N_Integer_Literal,
9598 N_Character_Literal,
9600 or else (Is_Entity_Name (N)
9601 and then Ekind (Entity (N)) = E_Enumeration_Literal)
9603 Set_Is_Static_Expression (N, Static);
9605 -- If this is still an attribute reference, then it has not been folded
9606 -- and that means that its expressions are in a non-static context.
9608 elsif Nkind (N) = N_Attribute_Reference then
9611 -- Note: the else case not covered here are odd cases where the
9612 -- processing has transformed the attribute into something other
9613 -- than a constant. Nothing more to do in such cases.
9620 ------------------------------
9621 -- Is_Anonymous_Tagged_Base --
9622 ------------------------------
9624 function Is_Anonymous_Tagged_Base
9631 Anon = Current_Scope
9632 and then Is_Itype (Anon)
9633 and then Associated_Node_For_Itype (Anon) = Parent (Typ);
9634 end Is_Anonymous_Tagged_Base;
9636 --------------------------------
9637 -- Name_Implies_Lvalue_Prefix --
9638 --------------------------------
9640 function Name_Implies_Lvalue_Prefix (Nam : Name_Id) return Boolean is
9641 pragma Assert (Is_Attribute_Name (Nam));
9643 return Attribute_Name_Implies_Lvalue_Prefix (Get_Attribute_Id (Nam));
9644 end Name_Implies_Lvalue_Prefix;
9646 -----------------------
9647 -- Resolve_Attribute --
9648 -----------------------
9650 procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is
9651 Loc : constant Source_Ptr := Sloc (N);
9652 P : constant Node_Id := Prefix (N);
9653 Aname : constant Name_Id := Attribute_Name (N);
9654 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
9655 Btyp : constant Entity_Id := Base_Type (Typ);
9656 Des_Btyp : Entity_Id;
9657 Index : Interp_Index;
9659 Nom_Subt : Entity_Id;
9661 procedure Accessibility_Message;
9662 -- Error, or warning within an instance, if the static accessibility
9663 -- rules of 3.10.2 are violated.
9665 ---------------------------
9666 -- Accessibility_Message --
9667 ---------------------------
9669 procedure Accessibility_Message is
9670 Indic : Node_Id := Parent (Parent (N));
9673 -- In an instance, this is a runtime check, but one we
9674 -- know will fail, so generate an appropriate warning.
9676 if In_Instance_Body then
9677 Error_Msg_Warn := SPARK_Mode /= On;
9679 ("non-local pointer cannot point to local object<<", P);
9680 Error_Msg_F ("\Program_Error [<<", P);
9682 Make_Raise_Program_Error (Loc,
9683 Reason => PE_Accessibility_Check_Failed));
9688 Error_Msg_F ("non-local pointer cannot point to local object", P);
9690 -- Check for case where we have a missing access definition
9692 if Is_Record_Type (Current_Scope)
9694 Nkind_In (Parent (N), N_Discriminant_Association,
9695 N_Index_Or_Discriminant_Constraint)
9697 Indic := Parent (Parent (N));
9698 while Present (Indic)
9699 and then Nkind (Indic) /= N_Subtype_Indication
9701 Indic := Parent (Indic);
9704 if Present (Indic) then
9706 ("\use an access definition for" &
9707 " the access discriminant of&",
9708 N, Entity (Subtype_Mark (Indic)));
9712 end Accessibility_Message;
9714 -- Start of processing for Resolve_Attribute
9717 -- If error during analysis, no point in continuing, except for array
9718 -- types, where we get better recovery by using unconstrained indexes
9719 -- than nothing at all (see Check_Array_Type).
9722 and then Attr_Id /= Attribute_First
9723 and then Attr_Id /= Attribute_Last
9724 and then Attr_Id /= Attribute_Length
9725 and then Attr_Id /= Attribute_Range
9730 -- If attribute was universal type, reset to actual type
9732 if Etype (N) = Universal_Integer
9733 or else Etype (N) = Universal_Real
9738 -- Remaining processing depends on attribute
9746 -- For access attributes, if the prefix denotes an entity, it is
9747 -- interpreted as a name, never as a call. It may be overloaded,
9748 -- in which case resolution uses the profile of the context type.
9749 -- Otherwise prefix must be resolved.
9751 when Attribute_Access
9752 | Attribute_Unchecked_Access
9753 | Attribute_Unrestricted_Access =>
9757 if Is_Variable (P) then
9758 Note_Possible_Modification (P, Sure => False);
9761 -- The following comes from a query concerning improper use of
9762 -- universal_access in equality tests involving anonymous access
9763 -- types. Another good reason for 'Ref, but for now disable the
9764 -- test, which breaks several filed tests???
9766 if Ekind (Typ) = E_Anonymous_Access_Type
9767 and then Nkind_In (Parent (N), N_Op_Eq, N_Op_Ne)
9770 Error_Msg_N ("need unique type to resolve 'Access", N);
9771 Error_Msg_N ("\qualify attribute with some access type", N);
9774 -- Case where prefix is an entity name
9776 if Is_Entity_Name (P) then
9778 -- Deal with case where prefix itself is overloaded
9780 if Is_Overloaded (P) then
9781 Get_First_Interp (P, Index, It);
9782 while Present (It.Nam) loop
9783 if Type_Conformant (Designated_Type (Typ), It.Nam) then
9784 Set_Entity (P, It.Nam);
9786 -- The prefix is definitely NOT overloaded anymore at
9787 -- this point, so we reset the Is_Overloaded flag to
9788 -- avoid any confusion when reanalyzing the node.
9790 Set_Is_Overloaded (P, False);
9791 Set_Is_Overloaded (N, False);
9792 Generate_Reference (Entity (P), P);
9796 Get_Next_Interp (Index, It);
9799 -- If Prefix is a subprogram name, this reference freezes:
9801 -- If it is a type, there is nothing to resolve.
9802 -- If it is an object, complete its resolution.
9804 elsif Is_Overloadable (Entity (P)) then
9806 -- Avoid insertion of freeze actions in spec expression mode
9808 if not In_Spec_Expression then
9809 Freeze_Before (N, Entity (P));
9812 -- Nothing to do if prefix is a type name
9814 elsif Is_Type (Entity (P)) then
9817 -- Otherwise non-overloaded other case, resolve the prefix
9823 -- Some further error checks
9825 Error_Msg_Name_1 := Aname;
9827 if not Is_Entity_Name (P) then
9830 elsif Is_Overloadable (Entity (P))
9831 and then Is_Abstract_Subprogram (Entity (P))
9833 Error_Msg_F ("prefix of % attribute cannot be abstract", P);
9834 Set_Etype (N, Any_Type);
9836 elsif Ekind (Entity (P)) = E_Enumeration_Literal then
9838 ("prefix of % attribute cannot be enumeration literal", P);
9839 Set_Etype (N, Any_Type);
9841 -- An attempt to take 'Access of a function that renames an
9842 -- enumeration literal. Issue a specialized error message.
9844 elsif Ekind (Entity (P)) = E_Function
9845 and then Present (Alias (Entity (P)))
9846 and then Ekind (Alias (Entity (P))) = E_Enumeration_Literal
9849 ("prefix of % attribute cannot be function renaming "
9850 & "an enumeration literal", P);
9851 Set_Etype (N, Any_Type);
9853 elsif Convention (Entity (P)) = Convention_Intrinsic then
9854 Error_Msg_F ("prefix of % attribute cannot be intrinsic", P);
9855 Set_Etype (N, Any_Type);
9858 -- Assignments, return statements, components of aggregates,
9859 -- generic instantiations will require convention checks if
9860 -- the type is an access to subprogram. Given that there will
9861 -- also be accessibility checks on those, this is where the
9862 -- checks can eventually be centralized ???
9864 if Ekind_In (Btyp, E_Access_Subprogram_Type,
9865 E_Anonymous_Access_Subprogram_Type,
9866 E_Access_Protected_Subprogram_Type,
9867 E_Anonymous_Access_Protected_Subprogram_Type)
9869 -- Deal with convention mismatch
9871 if Convention (Designated_Type (Btyp)) /=
9872 Convention (Entity (P))
9875 ("subprogram & has wrong convention", P, Entity (P));
9876 Error_Msg_Sloc := Sloc (Btyp);
9877 Error_Msg_FE ("\does not match & declared#", P, Btyp);
9879 if not Is_Itype (Btyp)
9880 and then not Has_Convention_Pragma (Btyp)
9883 ("\probable missing pragma Convention for &",
9888 Check_Subtype_Conformant
9889 (New_Id => Entity (P),
9890 Old_Id => Designated_Type (Btyp),
9894 if Attr_Id = Attribute_Unchecked_Access then
9895 Error_Msg_Name_1 := Aname;
9897 ("attribute% cannot be applied to a subprogram", P);
9899 elsif Aname = Name_Unrestricted_Access then
9900 null; -- Nothing to check
9902 -- Check the static accessibility rule of 3.10.2(32).
9903 -- This rule also applies within the private part of an
9904 -- instantiation. This rule does not apply to anonymous
9905 -- access-to-subprogram types in access parameters.
9907 elsif Attr_Id = Attribute_Access
9908 and then not In_Instance_Body
9910 (Ekind (Btyp) = E_Access_Subprogram_Type
9911 or else Is_Local_Anonymous_Access (Btyp))
9912 and then Subprogram_Access_Level (Entity (P)) >
9913 Type_Access_Level (Btyp)
9916 ("subprogram must not be deeper than access type", P);
9918 -- Check the restriction of 3.10.2(32) that disallows the
9919 -- access attribute within a generic body when the ultimate
9920 -- ancestor of the type of the attribute is declared outside
9921 -- of the generic unit and the subprogram is declared within
9922 -- that generic unit. This includes any such attribute that
9923 -- occurs within the body of a generic unit that is a child
9924 -- of the generic unit where the subprogram is declared.
9926 -- The rule also prohibits applying the attribute when the
9927 -- access type is a generic formal access type (since the
9928 -- level of the actual type is not known). This restriction
9929 -- does not apply when the attribute type is an anonymous
9930 -- access-to-subprogram type. Note that this check was
9931 -- revised by AI-229, because the originally Ada 95 rule
9932 -- was too lax. The original rule only applied when the
9933 -- subprogram was declared within the body of the generic,
9934 -- which allowed the possibility of dangling references).
9935 -- The rule was also too strict in some case, in that it
9936 -- didn't permit the access to be declared in the generic
9937 -- spec, whereas the revised rule does (as long as it's not
9940 -- There are a couple of subtleties of the test for applying
9941 -- the check that are worth noting. First, we only apply it
9942 -- when the levels of the subprogram and access type are the
9943 -- same (the case where the subprogram is statically deeper
9944 -- was applied above, and the case where the type is deeper
9945 -- is always safe). Second, we want the check to apply
9946 -- within nested generic bodies and generic child unit
9947 -- bodies, but not to apply to an attribute that appears in
9948 -- the generic unit's specification. This is done by testing
9949 -- that the attribute's innermost enclosing generic body is
9950 -- not the same as the innermost generic body enclosing the
9951 -- generic unit where the subprogram is declared (we don't
9952 -- want the check to apply when the access attribute is in
9953 -- the spec and there's some other generic body enclosing
9954 -- generic). Finally, there's no point applying the check
9955 -- when within an instance, because any violations will have
9956 -- been caught by the compilation of the generic unit.
9958 -- We relax this check in Relaxed_RM_Semantics mode for
9959 -- compatibility with legacy code for use by Ada source
9960 -- code analyzers (e.g. CodePeer).
9962 elsif Attr_Id = Attribute_Access
9963 and then not Relaxed_RM_Semantics
9964 and then not In_Instance
9965 and then Present (Enclosing_Generic_Unit (Entity (P)))
9966 and then Present (Enclosing_Generic_Body (N))
9967 and then Enclosing_Generic_Body (N) /=
9968 Enclosing_Generic_Body
9969 (Enclosing_Generic_Unit (Entity (P)))
9970 and then Subprogram_Access_Level (Entity (P)) =
9971 Type_Access_Level (Btyp)
9972 and then Ekind (Btyp) /=
9973 E_Anonymous_Access_Subprogram_Type
9974 and then Ekind (Btyp) /=
9975 E_Anonymous_Access_Protected_Subprogram_Type
9977 -- The attribute type's ultimate ancestor must be
9978 -- declared within the same generic unit as the
9979 -- subprogram is declared. The error message is
9980 -- specialized to say "ancestor" for the case where the
9981 -- access type is not its own ancestor, since saying
9982 -- simply "access type" would be very confusing.
9984 if Enclosing_Generic_Unit (Entity (P)) /=
9985 Enclosing_Generic_Unit (Root_Type (Btyp))
9988 ("''Access attribute not allowed in generic body",
9991 if Root_Type (Btyp) = Btyp then
9994 "access type & is declared outside " &
9995 "generic unit (RM 3.10.2(32))", N, Btyp);
9998 ("\because ancestor of " &
9999 "access type & is declared outside " &
10000 "generic unit (RM 3.10.2(32))", N, Btyp);
10004 ("\move ''Access to private part, or " &
10005 "(Ada 2005) use anonymous access type instead of &",
10008 -- If the ultimate ancestor of the attribute's type is
10009 -- a formal type, then the attribute is illegal because
10010 -- the actual type might be declared at a higher level.
10011 -- The error message is specialized to say "ancestor"
10012 -- for the case where the access type is not its own
10013 -- ancestor, since saying simply "access type" would be
10016 elsif Is_Generic_Type (Root_Type (Btyp)) then
10017 if Root_Type (Btyp) = Btyp then
10019 ("access type must not be a generic formal type",
10023 ("ancestor access type must not be a generic " &
10030 -- If this is a renaming, an inherited operation, or a
10031 -- subprogram instance, use the original entity. This may make
10032 -- the node type-inconsistent, so this transformation can only
10033 -- be done if the node will not be reanalyzed. In particular,
10034 -- if it is within a default expression, the transformation
10035 -- must be delayed until the default subprogram is created for
10036 -- it, when the enclosing subprogram is frozen.
10038 if Is_Entity_Name (P)
10039 and then Is_Overloadable (Entity (P))
10040 and then Present (Alias (Entity (P)))
10041 and then Expander_Active
10044 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
10047 elsif Nkind (P) = N_Selected_Component
10048 and then Is_Overloadable (Entity (Selector_Name (P)))
10050 -- Protected operation. If operation is overloaded, must
10051 -- disambiguate. Prefix that denotes protected object itself
10052 -- is resolved with its own type.
10054 if Attr_Id = Attribute_Unchecked_Access then
10055 Error_Msg_Name_1 := Aname;
10057 ("attribute% cannot be applied to protected operation", P);
10060 Resolve (Prefix (P));
10061 Generate_Reference (Entity (Selector_Name (P)), P);
10063 -- Implement check implied by 3.10.2 (18.1/2) : F.all'access is
10064 -- statically illegal if F is an anonymous access to subprogram.
10066 elsif Nkind (P) = N_Explicit_Dereference
10067 and then Is_Entity_Name (Prefix (P))
10068 and then Ekind (Etype (Entity (Prefix (P)))) =
10069 E_Anonymous_Access_Subprogram_Type
10071 Error_Msg_N ("anonymous access to subprogram "
10072 & "has deeper accessibility than any master", P);
10074 elsif Is_Overloaded (P) then
10076 -- Use the designated type of the context to disambiguate
10077 -- Note that this was not strictly conformant to Ada 95,
10078 -- but was the implementation adopted by most Ada 95 compilers.
10079 -- The use of the context type to resolve an Access attribute
10080 -- reference is now mandated in AI-235 for Ada 2005.
10083 Index : Interp_Index;
10087 Get_First_Interp (P, Index, It);
10088 while Present (It.Typ) loop
10089 if Covers (Designated_Type (Typ), It.Typ) then
10090 Resolve (P, It.Typ);
10094 Get_Next_Interp (Index, It);
10101 -- X'Access is illegal if X denotes a constant and the access type
10102 -- is access-to-variable. Same for 'Unchecked_Access. The rule
10103 -- does not apply to 'Unrestricted_Access. If the reference is a
10104 -- default-initialized aggregate component for a self-referential
10105 -- type the reference is legal.
10107 if not (Ekind (Btyp) = E_Access_Subprogram_Type
10108 or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
10109 or else (Is_Record_Type (Btyp)
10111 Present (Corresponding_Remote_Type (Btyp)))
10112 or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type
10113 or else Ekind (Btyp)
10114 = E_Anonymous_Access_Protected_Subprogram_Type
10115 or else Is_Access_Constant (Btyp)
10116 or else Is_Variable (P)
10117 or else Attr_Id = Attribute_Unrestricted_Access)
10119 if Is_Entity_Name (P)
10120 and then Is_Type (Entity (P))
10122 -- Legality of a self-reference through an access
10123 -- attribute has been verified in Analyze_Access_Attribute.
10127 elsif Comes_From_Source (N) then
10128 Error_Msg_F ("access-to-variable designates constant", P);
10132 Des_Btyp := Designated_Type (Btyp);
10134 if Ada_Version >= Ada_2005
10135 and then Is_Incomplete_Type (Des_Btyp)
10137 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
10138 -- imported entity, and the non-limited view is visible, make
10139 -- use of it. If it is an incomplete subtype, use the base type
10142 if From_Limited_With (Des_Btyp)
10143 and then Present (Non_Limited_View (Des_Btyp))
10145 Des_Btyp := Non_Limited_View (Des_Btyp);
10147 elsif Ekind (Des_Btyp) = E_Incomplete_Subtype then
10148 Des_Btyp := Etype (Des_Btyp);
10152 if (Attr_Id = Attribute_Access
10154 Attr_Id = Attribute_Unchecked_Access)
10155 and then (Ekind (Btyp) = E_General_Access_Type
10156 or else Ekind (Btyp) = E_Anonymous_Access_Type)
10158 -- Ada 2005 (AI-230): Check the accessibility of anonymous
10159 -- access types for stand-alone objects, record and array
10160 -- components, and return objects. For a component definition
10161 -- the level is the same of the enclosing composite type.
10163 if Ada_Version >= Ada_2005
10164 and then (Is_Local_Anonymous_Access (Btyp)
10166 -- Handle cases where Btyp is the anonymous access
10167 -- type of an Ada 2012 stand-alone object.
10169 or else Nkind (Associated_Node_For_Itype (Btyp)) =
10170 N_Object_Declaration)
10172 Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp)
10173 and then Attr_Id = Attribute_Access
10175 -- In an instance, this is a runtime check, but one we know
10176 -- will fail, so generate an appropriate warning. As usual,
10177 -- this kind of warning is an error in SPARK mode.
10179 if In_Instance_Body then
10180 Error_Msg_Warn := SPARK_Mode /= On;
10182 ("non-local pointer cannot point to local object<<", P);
10183 Error_Msg_F ("\Program_Error [<<", P);
10186 Make_Raise_Program_Error (Loc,
10187 Reason => PE_Accessibility_Check_Failed));
10188 Set_Etype (N, Typ);
10192 ("non-local pointer cannot point to local object", P);
10196 if Is_Dependent_Component_Of_Mutable_Object (P) then
10198 ("illegal attribute for discriminant-dependent component",
10202 -- Check static matching rule of 3.10.2(27). Nominal subtype
10203 -- of the prefix must statically match the designated type.
10205 Nom_Subt := Etype (P);
10207 if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then
10208 Nom_Subt := Base_Type (Nom_Subt);
10211 if Is_Tagged_Type (Designated_Type (Typ)) then
10213 -- If the attribute is in the context of an access
10214 -- parameter, then the prefix is allowed to be of
10215 -- the class-wide type (by AI-127).
10217 if Ekind (Typ) = E_Anonymous_Access_Type then
10218 if not Covers (Designated_Type (Typ), Nom_Subt)
10219 and then not Covers (Nom_Subt, Designated_Type (Typ))
10225 Desig := Designated_Type (Typ);
10227 if Is_Class_Wide_Type (Desig) then
10228 Desig := Etype (Desig);
10231 if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then
10236 ("type of prefix: & not compatible",
10239 ("\with &, the expected designated type",
10240 P, Designated_Type (Typ));
10245 elsif not Covers (Designated_Type (Typ), Nom_Subt)
10247 (not Is_Class_Wide_Type (Designated_Type (Typ))
10248 and then Is_Class_Wide_Type (Nom_Subt))
10251 ("type of prefix: & is not covered", P, Nom_Subt);
10253 ("\by &, the expected designated type" &
10254 " (RM 3.10.2 (27))", P, Designated_Type (Typ));
10257 if Is_Class_Wide_Type (Designated_Type (Typ))
10258 and then Has_Discriminants (Etype (Designated_Type (Typ)))
10259 and then Is_Constrained (Etype (Designated_Type (Typ)))
10260 and then Designated_Type (Typ) /= Nom_Subt
10262 Apply_Discriminant_Check
10263 (N, Etype (Designated_Type (Typ)));
10266 -- Ada 2005 (AI-363): Require static matching when designated
10267 -- type has discriminants and a constrained partial view, since
10268 -- in general objects of such types are mutable, so we can't
10269 -- allow the access value to designate a constrained object
10270 -- (because access values must be assumed to designate mutable
10271 -- objects when designated type does not impose a constraint).
10273 elsif Subtypes_Statically_Match (Des_Btyp, Nom_Subt) then
10276 elsif Has_Discriminants (Designated_Type (Typ))
10277 and then not Is_Constrained (Des_Btyp)
10279 (Ada_Version < Ada_2005
10281 not Object_Type_Has_Constrained_Partial_View
10282 (Typ => Designated_Type (Base_Type (Typ)),
10283 Scop => Current_Scope))
10289 ("object subtype must statically match "
10290 & "designated subtype", P);
10292 if Is_Entity_Name (P)
10293 and then Is_Array_Type (Designated_Type (Typ))
10296 D : constant Node_Id := Declaration_Node (Entity (P));
10299 ("aliased object has explicit bounds??", D);
10301 ("\declare without bounds (and with explicit "
10302 & "initialization)??", D);
10304 ("\for use with unconstrained access??", D);
10309 -- Check the static accessibility rule of 3.10.2(28). Note that
10310 -- this check is not performed for the case of an anonymous
10311 -- access type, since the access attribute is always legal
10312 -- in such a context.
10314 if Attr_Id /= Attribute_Unchecked_Access
10315 and then Ekind (Btyp) = E_General_Access_Type
10317 Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp)
10319 Accessibility_Message;
10324 if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type,
10325 E_Anonymous_Access_Protected_Subprogram_Type)
10327 if Is_Entity_Name (P)
10328 and then not Is_Protected_Type (Scope (Entity (P)))
10330 Error_Msg_F ("context requires a protected subprogram", P);
10332 -- Check accessibility of protected object against that of the
10333 -- access type, but only on user code, because the expander
10334 -- creates access references for handlers. If the context is an
10335 -- anonymous_access_to_protected, there are no accessibility
10336 -- checks either. Omit check entirely for Unrestricted_Access.
10338 elsif Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp)
10339 and then Comes_From_Source (N)
10340 and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type
10341 and then Attr_Id /= Attribute_Unrestricted_Access
10343 Accessibility_Message;
10346 -- AI05-0225: If the context is not an access to protected
10347 -- function, the prefix must be a variable, given that it may
10348 -- be used subsequently in a protected call.
10350 elsif Nkind (P) = N_Selected_Component
10351 and then not Is_Variable (Prefix (P))
10352 and then Ekind (Entity (Selector_Name (P))) /= E_Function
10355 ("target object of access to protected procedure "
10356 & "must be variable", N);
10358 elsif Is_Entity_Name (P) then
10359 Check_Internal_Protected_Use (N, Entity (P));
10362 elsif Ekind_In (Btyp, E_Access_Subprogram_Type,
10363 E_Anonymous_Access_Subprogram_Type)
10364 and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type
10366 Error_Msg_F ("context requires a non-protected subprogram", P);
10369 -- The context cannot be a pool-specific type, but this is a
10370 -- legality rule, not a resolution rule, so it must be checked
10371 -- separately, after possibly disambiguation (see AI-245).
10373 if Ekind (Btyp) = E_Access_Type
10374 and then Attr_Id /= Attribute_Unrestricted_Access
10376 Wrong_Type (N, Typ);
10379 -- The context may be a constrained access type (however ill-
10380 -- advised such subtypes might be) so in order to generate a
10381 -- constraint check when needed set the type of the attribute
10382 -- reference to the base type of the context.
10384 Set_Etype (N, Btyp);
10386 -- Check for incorrect atomic/volatile reference (RM C.6(12))
10388 if Attr_Id /= Attribute_Unrestricted_Access then
10389 if Is_Atomic_Object (P)
10390 and then not Is_Atomic (Designated_Type (Typ))
10393 ("access to atomic object cannot yield access-to-" &
10394 "non-atomic type", P);
10396 elsif Is_Volatile_Object (P)
10397 and then not Is_Volatile (Designated_Type (Typ))
10400 ("access to volatile object cannot yield access-to-" &
10401 "non-volatile type", P);
10405 -- Check for unrestricted access where expected type is a thin
10406 -- pointer to an unconstrained array.
10408 if Non_Aliased_Prefix (N)
10409 and then Has_Size_Clause (Typ)
10410 and then RM_Size (Typ) = System_Address_Size
10413 DT : constant Entity_Id := Designated_Type (Typ);
10415 if Is_Array_Type (DT) and then not Is_Constrained (DT) then
10417 ("illegal use of Unrestricted_Access attribute", P);
10419 ("\attempt to generate thin pointer to unaliased "
10425 -- Mark that address of entity is taken
10427 if Is_Entity_Name (P) then
10428 Set_Address_Taken (Entity (P));
10430 end Access_Attribute;
10436 -- Deal with resolving the type for Address attribute, overloading
10437 -- is not permitted here, since there is no context to resolve it.
10439 when Attribute_Address | Attribute_Code_Address =>
10440 Address_Attribute : begin
10442 -- To be safe, assume that if the address of a variable is taken,
10443 -- it may be modified via this address, so note modification.
10445 if Is_Variable (P) then
10446 Note_Possible_Modification (P, Sure => False);
10449 if Nkind (P) in N_Subexpr
10450 and then Is_Overloaded (P)
10452 Get_First_Interp (P, Index, It);
10453 Get_Next_Interp (Index, It);
10455 if Present (It.Nam) then
10456 Error_Msg_Name_1 := Aname;
10458 ("prefix of % attribute cannot be overloaded", P);
10462 if not Is_Entity_Name (P)
10463 or else not Is_Overloadable (Entity (P))
10465 if not Is_Task_Type (Etype (P))
10466 or else Nkind (P) = N_Explicit_Dereference
10472 -- If this is the name of a derived subprogram, or that of a
10473 -- generic actual, the address is that of the original entity.
10475 if Is_Entity_Name (P)
10476 and then Is_Overloadable (Entity (P))
10477 and then Present (Alias (Entity (P)))
10480 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
10483 if Is_Entity_Name (P) then
10484 Set_Address_Taken (Entity (P));
10487 if Nkind (P) = N_Slice then
10489 -- Arr (X .. Y)'address is identical to Arr (X)'address,
10490 -- even if the array is packed and the slice itself is not
10491 -- addressable. Transform the prefix into an indexed component.
10493 -- Note that the transformation is safe only if we know that
10494 -- the slice is non-null. That is because a null slice can have
10495 -- an out of bounds index value.
10497 -- Right now, gigi blows up if given 'Address on a slice as a
10498 -- result of some incorrect freeze nodes generated by the front
10499 -- end, and this covers up that bug in one case, but the bug is
10500 -- likely still there in the cases not handled by this code ???
10502 -- It's not clear what 'Address *should* return for a null
10503 -- slice with out of bounds indexes, this might be worth an ARG
10506 -- One approach would be to do a length check unconditionally,
10507 -- and then do the transformation below unconditionally, but
10508 -- analyze with checks off, avoiding the problem of the out of
10509 -- bounds index. This approach would interpret the address of
10510 -- an out of bounds null slice as being the address where the
10511 -- array element would be if there was one, which is probably
10512 -- as reasonable an interpretation as any ???
10515 Loc : constant Source_Ptr := Sloc (P);
10516 D : constant Node_Id := Discrete_Range (P);
10520 if Is_Entity_Name (D)
10523 (Type_Low_Bound (Entity (D)),
10524 Type_High_Bound (Entity (D)))
10527 Make_Attribute_Reference (Loc,
10528 Prefix => (New_Occurrence_Of (Entity (D), Loc)),
10529 Attribute_Name => Name_First);
10531 elsif Nkind (D) = N_Range
10532 and then Not_Null_Range (Low_Bound (D), High_Bound (D))
10534 Lo := Low_Bound (D);
10540 if Present (Lo) then
10542 Make_Indexed_Component (Loc,
10543 Prefix => Relocate_Node (Prefix (P)),
10544 Expressions => New_List (Lo)));
10546 Analyze_And_Resolve (P);
10550 end Address_Attribute;
10556 -- Prefix of the AST_Entry attribute is an entry name which must
10557 -- not be resolved, since this is definitely not an entry call.
10559 when Attribute_AST_Entry =>
10566 -- Prefix of Body_Version attribute can be a subprogram name which
10567 -- must not be resolved, since this is not a call.
10569 when Attribute_Body_Version =>
10576 -- Prefix of Caller attribute is an entry name which must not
10577 -- be resolved, since this is definitely not an entry call.
10579 when Attribute_Caller =>
10586 -- Shares processing with Address attribute
10592 -- If the prefix of the Count attribute is an entry name it must not
10593 -- be resolved, since this is definitely not an entry call. However,
10594 -- if it is an element of an entry family, the index itself may
10595 -- have to be resolved because it can be a general expression.
10597 when Attribute_Count =>
10598 if Nkind (P) = N_Indexed_Component
10599 and then Is_Entity_Name (Prefix (P))
10602 Indx : constant Node_Id := First (Expressions (P));
10603 Fam : constant Entity_Id := Entity (Prefix (P));
10605 Resolve (Indx, Entry_Index_Type (Fam));
10606 Apply_Range_Check (Indx, Entry_Index_Type (Fam));
10614 -- Prefix of the Elaborated attribute is a subprogram name which
10615 -- must not be resolved, since this is definitely not a call. Note
10616 -- that it is a library unit, so it cannot be overloaded here.
10618 when Attribute_Elaborated =>
10625 -- Prefix of Enabled attribute is a check name, which must be treated
10626 -- specially and not touched by Resolve.
10628 when Attribute_Enabled =>
10635 -- Do not resolve the prefix of Loop_Entry, instead wait until the
10636 -- attribute has been expanded (see Expand_Loop_Entry_Attributes).
10637 -- The delay ensures that any generated checks or temporaries are
10638 -- inserted before the relocated prefix.
10640 when Attribute_Loop_Entry =>
10643 --------------------
10644 -- Mechanism_Code --
10645 --------------------
10647 -- Prefix of the Mechanism_Code attribute is a function name
10648 -- which must not be resolved. Should we check for overloaded ???
10650 when Attribute_Mechanism_Code =>
10657 -- Most processing is done in sem_dist, after determining the
10658 -- context type. Node is rewritten as a conversion to a runtime call.
10660 when Attribute_Partition_ID =>
10661 Process_Partition_Id (N);
10668 when Attribute_Pool_Address =>
10675 -- We replace the Range attribute node with a range expression whose
10676 -- bounds are the 'First and 'Last attributes applied to the same
10677 -- prefix. The reason that we do this transformation here instead of
10678 -- in the expander is that it simplifies other parts of the semantic
10679 -- analysis which assume that the Range has been replaced; thus it
10680 -- must be done even when in semantic-only mode (note that the RM
10681 -- specifically mentions this equivalence, we take care that the
10682 -- prefix is only evaluated once).
10684 when Attribute_Range => Range_Attribute :
10691 if not Is_Entity_Name (P)
10692 or else not Is_Type (Entity (P))
10697 Dims := Expressions (N);
10700 Make_Attribute_Reference (Loc,
10701 Prefix => Duplicate_Subexpr (P, Name_Req => True),
10702 Attribute_Name => Name_Last,
10703 Expressions => Dims);
10706 Make_Attribute_Reference (Loc,
10708 Attribute_Name => Name_First,
10709 Expressions => (Dims));
10711 -- Do not share the dimension indicator, if present. Even
10712 -- though it is a static constant, its source location
10713 -- may be modified when printing expanded code and node
10714 -- sharing will lead to chaos in Sprint.
10716 if Present (Dims) then
10717 Set_Expressions (LB,
10718 New_List (New_Copy_Tree (First (Dims))));
10721 -- If the original was marked as Must_Not_Freeze (see code
10722 -- in Sem_Ch3.Make_Index), then make sure the rewriting
10723 -- does not freeze either.
10725 if Must_Not_Freeze (N) then
10726 Set_Must_Not_Freeze (HB);
10727 Set_Must_Not_Freeze (LB);
10728 Set_Must_Not_Freeze (Prefix (HB));
10729 Set_Must_Not_Freeze (Prefix (LB));
10732 if Raises_Constraint_Error (Prefix (N)) then
10734 -- Preserve Sloc of prefix in the new bounds, so that
10735 -- the posted warning can be removed if we are within
10736 -- unreachable code.
10738 Set_Sloc (LB, Sloc (Prefix (N)));
10739 Set_Sloc (HB, Sloc (Prefix (N)));
10742 Rewrite (N, Make_Range (Loc, LB, HB));
10743 Analyze_And_Resolve (N, Typ);
10745 -- Ensure that the expanded range does not have side effects
10747 Force_Evaluation (LB);
10748 Force_Evaluation (HB);
10750 -- Normally after resolving attribute nodes, Eval_Attribute
10751 -- is called to do any possible static evaluation of the node.
10752 -- However, here since the Range attribute has just been
10753 -- transformed into a range expression it is no longer an
10754 -- attribute node and therefore the call needs to be avoided
10755 -- and is accomplished by simply returning from the procedure.
10758 end Range_Attribute;
10764 -- We will only come here during the prescan of a spec expression
10765 -- containing a Result attribute. In that case the proper Etype has
10766 -- already been set, and nothing more needs to be done here.
10768 when Attribute_Result =>
10775 -- Prefix must not be resolved in this case, since it is not a
10776 -- real entity reference. No action of any kind is require.
10778 when Attribute_UET_Address =>
10781 ----------------------
10782 -- Unchecked_Access --
10783 ----------------------
10785 -- Processing is shared with Access
10787 -------------------------
10788 -- Unrestricted_Access --
10789 -------------------------
10791 -- Processing is shared with Access
10797 -- Resolve aggregate components in component associations
10799 when Attribute_Update =>
10801 Aggr : constant Node_Id := First (Expressions (N));
10802 Typ : constant Entity_Id := Etype (Prefix (N));
10808 -- Set the Etype of the aggregate to that of the prefix, even
10809 -- though the aggregate may not be a proper representation of a
10810 -- value of the type (missing or duplicated associations, etc.)
10811 -- Complete resolution of the prefix. Note that in Ada 2012 it
10812 -- can be a qualified expression that is e.g. an aggregate.
10814 Set_Etype (Aggr, Typ);
10815 Resolve (Prefix (N), Typ);
10817 -- For an array type, resolve expressions with the component
10818 -- type of the array, and apply constraint checks when needed.
10820 if Is_Array_Type (Typ) then
10821 Assoc := First (Component_Associations (Aggr));
10822 while Present (Assoc) loop
10823 Expr := Expression (Assoc);
10824 Resolve (Expr, Component_Type (Typ));
10825 Aggregate_Constraint_Checks (Expr, Component_Type (Typ));
10827 -- The choices in the association are static constants,
10828 -- or static aggregates each of whose components belongs
10829 -- to the proper index type. However, they must also
10830 -- belong to the index subtype (s) of the prefix, which
10831 -- may be a subtype (e.g. given by a slice).
10833 -- Choices may also be identifiers with no staticness
10834 -- requirements, in which case they must resolve to the
10843 C := First (Choices (Assoc));
10844 while Present (C) loop
10845 Indx := First_Index (Etype (Prefix (N)));
10847 if Nkind (C) /= N_Aggregate then
10848 Analyze_And_Resolve (C, Etype (Indx));
10849 Apply_Constraint_Check (C, Etype (Indx));
10850 Check_Non_Static_Context (C);
10853 C_E := First (Expressions (C));
10854 while Present (C_E) loop
10855 Analyze_And_Resolve (C_E, Etype (Indx));
10856 Apply_Constraint_Check (C_E, Etype (Indx));
10857 Check_Non_Static_Context (C_E);
10871 -- For a record type, use type of each component, which is
10872 -- recorded during analysis.
10875 Assoc := First (Component_Associations (Aggr));
10876 while Present (Assoc) loop
10877 Comp := First (Choices (Assoc));
10879 if Nkind (Comp) /= N_Others_Choice
10880 and then not Error_Posted (Comp)
10882 Resolve (Expression (Assoc), Etype (Entity (Comp)));
10890 -- Premature return requires comment ???
10898 -- Apply range check. Note that we did not do this during the
10899 -- analysis phase, since we wanted Eval_Attribute to have a
10900 -- chance at finding an illegal out of range value.
10902 when Attribute_Val =>
10904 -- Note that we do our own Eval_Attribute call here rather than
10905 -- use the common one, because we need to do processing after
10906 -- the call, as per above comment.
10908 Eval_Attribute (N);
10910 -- Eval_Attribute may replace the node with a raise CE, or
10911 -- fold it to a constant. Obviously we only apply a scalar
10912 -- range check if this did not happen.
10914 if Nkind (N) = N_Attribute_Reference
10915 and then Attribute_Name (N) = Name_Val
10917 Apply_Scalar_Range_Check (First (Expressions (N)), Btyp);
10926 -- Prefix of Version attribute can be a subprogram name which
10927 -- must not be resolved, since this is not a call.
10929 when Attribute_Version =>
10932 ----------------------
10933 -- Other Attributes --
10934 ----------------------
10936 -- For other attributes, resolve prefix unless it is a type. If
10937 -- the attribute reference itself is a type name ('Base and 'Class)
10938 -- then this is only legal within a task or protected record.
10941 if not Is_Entity_Name (P) or else not Is_Type (Entity (P)) then
10945 -- If the attribute reference itself is a type name ('Base,
10946 -- 'Class) then this is only legal within a task or protected
10947 -- record. What is this all about ???
10949 if Is_Entity_Name (N) and then Is_Type (Entity (N)) then
10950 if Is_Concurrent_Type (Entity (N))
10951 and then In_Open_Scopes (Entity (P))
10956 ("invalid use of subtype name in expression or call", N);
10960 -- For attributes whose argument may be a string, complete
10961 -- resolution of argument now. This avoids premature expansion
10962 -- (and the creation of transient scopes) before the attribute
10963 -- reference is resolved.
10966 when Attribute_Value =>
10967 Resolve (First (Expressions (N)), Standard_String);
10969 when Attribute_Wide_Value =>
10970 Resolve (First (Expressions (N)), Standard_Wide_String);
10972 when Attribute_Wide_Wide_Value =>
10973 Resolve (First (Expressions (N)), Standard_Wide_Wide_String);
10975 when others => null;
10978 -- If the prefix of the attribute is a class-wide type then it
10979 -- will be expanded into a dispatching call to a predefined
10980 -- primitive. Therefore we must check for potential violation
10981 -- of such restriction.
10983 if Is_Class_Wide_Type (Etype (P)) then
10984 Check_Restriction (No_Dispatching_Calls, N);
10988 -- Normally the Freezing is done by Resolve but sometimes the Prefix
10989 -- is not resolved, in which case the freezing must be done now.
10991 Freeze_Expression (P);
10993 -- Finally perform static evaluation on the attribute reference
10995 Analyze_Dimension (N);
10996 Eval_Attribute (N);
10997 end Resolve_Attribute;
10999 ------------------------
11000 -- Set_Boolean_Result --
11001 ------------------------
11003 procedure Set_Boolean_Result (N : Node_Id; B : Boolean) is
11004 Loc : constant Source_Ptr := Sloc (N);
11008 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
11010 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
11013 Set_Is_Static_Expression (N);
11014 end Set_Boolean_Result;
11016 --------------------------------
11017 -- Stream_Attribute_Available --
11018 --------------------------------
11020 function Stream_Attribute_Available
11022 Nam : TSS_Name_Type;
11023 Partial_View : Node_Id := Empty) return Boolean
11025 Etyp : Entity_Id := Typ;
11027 -- Start of processing for Stream_Attribute_Available
11030 -- We need some comments in this body ???
11032 if Has_Stream_Attribute_Definition (Typ, Nam) then
11036 if Is_Class_Wide_Type (Typ) then
11037 return not Is_Limited_Type (Typ)
11038 or else Stream_Attribute_Available (Etype (Typ), Nam);
11041 if Nam = TSS_Stream_Input
11042 and then Is_Abstract_Type (Typ)
11043 and then not Is_Class_Wide_Type (Typ)
11048 if not (Is_Limited_Type (Typ)
11049 or else (Present (Partial_View)
11050 and then Is_Limited_Type (Partial_View)))
11055 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
11057 if Nam = TSS_Stream_Input
11058 and then Ada_Version >= Ada_2005
11059 and then Stream_Attribute_Available (Etyp, TSS_Stream_Read)
11063 elsif Nam = TSS_Stream_Output
11064 and then Ada_Version >= Ada_2005
11065 and then Stream_Attribute_Available (Etyp, TSS_Stream_Write)
11070 -- Case of Read and Write: check for attribute definition clause that
11071 -- applies to an ancestor type.
11073 while Etype (Etyp) /= Etyp loop
11074 Etyp := Etype (Etyp);
11076 if Has_Stream_Attribute_Definition (Etyp, Nam) then
11081 if Ada_Version < Ada_2005 then
11083 -- In Ada 95 mode, also consider a non-visible definition
11086 Btyp : constant Entity_Id := Implementation_Base_Type (Typ);
11089 and then Stream_Attribute_Available
11090 (Btyp, Nam, Partial_View => Typ);
11095 end Stream_Attribute_Available;