1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2015, 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_Prag
; use Sem_Prag
;
63 with Sem_Res
; use Sem_Res
;
64 with Sem_Type
; use Sem_Type
;
65 with Sem_Util
; use Sem_Util
;
67 with Stand
; use Stand
;
68 with Sinfo
; use Sinfo
;
69 with Sinput
; use Sinput
;
71 with Stringt
; use Stringt
;
73 with Stylesw
; use Stylesw
;
74 with Targparm
; use Targparm
;
75 with Ttypes
; use Ttypes
;
76 with Tbuild
; use Tbuild
;
77 with Uintp
; use Uintp
;
78 with Uname
; use Uname
;
79 with Urealp
; use Urealp
;
81 package body Sem_Attr
is
83 True_Value
: constant Uint
:= Uint_1
;
84 False_Value
: constant Uint
:= Uint_0
;
85 -- Synonyms to be used when these constants are used as Boolean values
87 Bad_Attribute
: exception;
88 -- Exception raised if an error is detected during attribute processing,
89 -- used so that we can abandon the processing so we don't run into
90 -- trouble with cascaded errors.
92 -- The following array is the list of attributes defined in the Ada 83 RM.
93 -- In Ada 83 mode, these are the only recognized attributes. In other Ada
94 -- modes all these attributes are recognized, even if removed in Ada 95.
96 Attribute_83
: constant Attribute_Class_Array
:= Attribute_Class_Array
'(
102 Attribute_Constrained |
109 Attribute_First_Bit |
115 Attribute_Leading_Part |
117 Attribute_Machine_Emax |
118 Attribute_Machine_Emin |
119 Attribute_Machine_Mantissa |
120 Attribute_Machine_Overflows |
121 Attribute_Machine_Radix |
122 Attribute_Machine_Rounds |
128 Attribute_Safe_Emax |
129 Attribute_Safe_Large |
130 Attribute_Safe_Small |
133 Attribute_Storage_Size |
135 Attribute_Terminated |
138 Attribute_Width => True,
141 -- The following array is the list of attributes defined in the Ada 2005
142 -- RM which are not defined in Ada 95. These are recognized in Ada 95 mode,
143 -- but in Ada 95 they are considered to be implementation defined.
145 Attribute_05 : constant Attribute_Class_Array := Attribute_Class_Array'(
146 Attribute_Machine_Rounding |
149 Attribute_Stream_Size |
150 Attribute_Wide_Wide_Width
=> True,
153 -- The following array is the list of attributes defined in the Ada 2012
154 -- RM which are not defined in Ada 2005. These are recognized in Ada 95
155 -- and Ada 2005 modes, but are considered to be implementation defined.
157 Attribute_12
: constant Attribute_Class_Array
:= Attribute_Class_Array
'(
158 Attribute_First_Valid |
159 Attribute_Has_Same_Storage |
160 Attribute_Last_Valid |
161 Attribute_Max_Alignment_For_Allocation => True,
164 -- The following array contains all attributes that imply a modification
165 -- of their prefixes or result in an access value. Such prefixes can be
166 -- considered as lvalues.
168 Attribute_Name_Implies_Lvalue_Prefix : constant Attribute_Class_Array :=
169 Attribute_Class_Array'(
174 Attribute_Unchecked_Access |
175 Attribute_Unrestricted_Access
=> True,
178 -----------------------
179 -- Local_Subprograms --
180 -----------------------
182 procedure Eval_Attribute
(N
: Node_Id
);
183 -- Performs compile time evaluation of attributes where possible, leaving
184 -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately
185 -- set, and replacing the node with a literal node if the value can be
186 -- computed at compile time. All static attribute references are folded,
187 -- as well as a number of cases of non-static attributes that can always
188 -- be computed at compile time (e.g. floating-point model attributes that
189 -- are applied to non-static subtypes). Of course in such cases, the
190 -- Is_Static_Expression flag will not be set on the resulting literal.
191 -- Note that the only required action of this procedure is to catch the
192 -- static expression cases as described in the RM. Folding of other cases
193 -- is done where convenient, but some additional non-static folding is in
194 -- Expand_N_Attribute_Reference in cases where this is more convenient.
196 function Is_Anonymous_Tagged_Base
198 Typ
: Entity_Id
) return Boolean;
199 -- For derived tagged types that constrain parent discriminants we build
200 -- an anonymous unconstrained base type. We need to recognize the relation
201 -- between the two when analyzing an access attribute for a constrained
202 -- component, before the full declaration for Typ has been analyzed, and
203 -- where therefore the prefix of the attribute does not match the enclosing
206 procedure Set_Boolean_Result
(N
: Node_Id
; B
: Boolean);
207 -- Rewrites node N with an occurrence of either Standard_False or
208 -- Standard_True, depending on the value of the parameter B. The
209 -- result is marked as a static expression.
211 -----------------------
212 -- Analyze_Attribute --
213 -----------------------
215 procedure Analyze_Attribute
(N
: Node_Id
) is
216 Loc
: constant Source_Ptr
:= Sloc
(N
);
217 Aname
: constant Name_Id
:= Attribute_Name
(N
);
218 P
: constant Node_Id
:= Prefix
(N
);
219 Exprs
: constant List_Id
:= Expressions
(N
);
220 Attr_Id
: constant Attribute_Id
:= Get_Attribute_Id
(Aname
);
225 -- Type of prefix after analysis
227 P_Base_Type
: Entity_Id
;
228 -- Base type of prefix after analysis
230 -----------------------
231 -- Local Subprograms --
232 -----------------------
234 procedure Address_Checks
;
235 -- Semantic checks for valid use of Address attribute. This was made
236 -- a separate routine with the idea of using it for unrestricted access
237 -- which seems like it should follow the same rules, but that turned
238 -- out to be impractical. So now this is only used for Address.
240 procedure Analyze_Access_Attribute
;
241 -- Used for Access, Unchecked_Access, Unrestricted_Access attributes.
242 -- Internally, Id distinguishes which of the three cases is involved.
244 procedure Analyze_Attribute_Old_Result
245 (Legal
: out Boolean;
246 Spec_Id
: out Entity_Id
);
247 -- Common processing for attributes 'Old and 'Result. The routine checks
248 -- that the attribute appears in a postcondition-like aspect or pragma
249 -- associated with a suitable subprogram or a body. Flag Legal is set
250 -- when the above criteria are met. Spec_Id denotes the entity of the
251 -- subprogram [body] or Empty if the attribute is illegal.
253 procedure Bad_Attribute_For_Predicate
;
254 -- Output error message for use of a predicate (First, Last, Range) not
255 -- allowed with a type that has predicates. If the type is a generic
256 -- actual, then the message is a warning, and we generate code to raise
257 -- program error with an appropriate reason. No error message is given
258 -- for internally generated uses of the attributes. This legality rule
259 -- only applies to scalar types.
261 procedure Check_Array_Or_Scalar_Type
;
262 -- Common procedure used by First, Last, Range attribute to check
263 -- that the prefix is a constrained array or scalar type, or a name
264 -- of an array object, and that an argument appears only if appropriate
265 -- (i.e. only in the array case).
267 procedure Check_Array_Type
;
268 -- Common semantic checks for all array attributes. Checks that the
269 -- prefix is a constrained array type or the name of an array object.
270 -- The error message for non-arrays is specialized appropriately.
272 procedure Check_Asm_Attribute
;
273 -- Common semantic checks for Asm_Input and Asm_Output attributes
275 procedure Check_Component
;
276 -- Common processing for Bit_Position, First_Bit, Last_Bit, and
277 -- Position. Checks prefix is an appropriate selected component.
279 procedure Check_Decimal_Fixed_Point_Type
;
280 -- Check that prefix of attribute N is a decimal fixed-point type
282 procedure Check_Dereference
;
283 -- If the prefix of attribute is an object of an access type, then
284 -- introduce an explicit dereference, and adjust P_Type accordingly.
286 procedure Check_Discrete_Type
;
287 -- Verify that prefix of attribute N is a discrete type
290 -- Check that no attribute arguments are present
292 procedure Check_Either_E0_Or_E1
;
293 -- Check that there are zero or one attribute arguments present
296 -- Check that exactly one attribute argument is present
299 -- Check that two attribute arguments are present
301 procedure Check_Enum_Image
;
302 -- If the prefix type of 'Image is an enumeration type, set all its
303 -- literals as referenced, since the image function could possibly end
304 -- up referencing any of the literals indirectly. Same for Enum_Val.
305 -- Set the flag only if the reference is in the main code unit. Same
306 -- restriction when resolving 'Value; otherwise an improperly set
307 -- reference when analyzing an inlined body will lose a proper
308 -- warning on a useless with_clause.
310 procedure Check_First_Last_Valid
;
311 -- Perform all checks for First_Valid and Last_Valid attributes
313 procedure Check_Fixed_Point_Type
;
314 -- Verify that prefix of attribute N is a fixed type
316 procedure Check_Fixed_Point_Type_0
;
317 -- Verify that prefix of attribute N is a fixed type and that
318 -- no attribute expressions are present
320 procedure Check_Floating_Point_Type
;
321 -- Verify that prefix of attribute N is a float type
323 procedure Check_Floating_Point_Type_0
;
324 -- Verify that prefix of attribute N is a float type and that
325 -- no attribute expressions are present
327 procedure Check_Floating_Point_Type_1
;
328 -- Verify that prefix of attribute N is a float type and that
329 -- exactly one attribute expression is present
331 procedure Check_Floating_Point_Type_2
;
332 -- Verify that prefix of attribute N is a float type and that
333 -- two attribute expressions are present
335 procedure Check_SPARK_05_Restriction_On_Attribute
;
336 -- Issue an error in formal mode because attribute N is allowed
338 procedure Check_Integer_Type
;
339 -- Verify that prefix of attribute N is an integer type
341 procedure Check_Modular_Integer_Type
;
342 -- Verify that prefix of attribute N is a modular integer type
344 procedure Check_Not_CPP_Type
;
345 -- Check that P (the prefix of the attribute) is not an CPP type
346 -- for which no Ada predefined primitive is available.
348 procedure Check_Not_Incomplete_Type
;
349 -- Check that P (the prefix of the attribute) is not an incomplete
350 -- type or a private type for which no full view has been given.
352 procedure Check_Object_Reference
(P
: Node_Id
);
353 -- Check that P is an object reference
355 procedure Check_PolyORB_Attribute
;
356 -- Validity checking for PolyORB/DSA attribute
358 procedure Check_Program_Unit
;
359 -- Verify that prefix of attribute N is a program unit
361 procedure Check_Real_Type
;
362 -- Verify that prefix of attribute N is fixed or float type
364 procedure Check_Scalar_Type
;
365 -- Verify that prefix of attribute N is a scalar type
367 procedure Check_Standard_Prefix
;
368 -- Verify that prefix of attribute N is package Standard. Also checks
369 -- that there are no arguments.
371 procedure Check_Stream_Attribute
(Nam
: TSS_Name_Type
);
372 -- Validity checking for stream attribute. Nam is the TSS name of the
373 -- corresponding possible defined attribute function (e.g. for the
374 -- Read attribute, Nam will be TSS_Stream_Read).
376 procedure Check_System_Prefix
;
377 -- Verify that prefix of attribute N is package System
379 procedure Check_Task_Prefix
;
380 -- Verify that prefix of attribute N is a task or task type
382 procedure Check_Type
;
383 -- Verify that the prefix of attribute N is a type
385 procedure Check_Unit_Name
(Nod
: Node_Id
);
386 -- Check that Nod is of the form of a library unit name, i.e that
387 -- it is an identifier, or a selected component whose prefix is
388 -- itself of the form of a library unit name. Note that this is
389 -- quite different from Check_Program_Unit, since it only checks
390 -- the syntactic form of the name, not the semantic identity. This
391 -- is because it is used with attributes (Elab_Body, Elab_Spec,
392 -- UET_Address and Elaborated) which can refer to non-visible unit.
394 procedure Error_Attr
(Msg
: String; Error_Node
: Node_Id
);
395 pragma No_Return
(Error_Attr
);
396 procedure Error_Attr
;
397 pragma No_Return
(Error_Attr
);
398 -- Posts error using Error_Msg_N at given node, sets type of attribute
399 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
400 -- semantic processing. The message typically contains a % insertion
401 -- character which is replaced by the attribute name. The call with
402 -- no arguments is used when the caller has already generated the
403 -- required error messages.
405 procedure Error_Attr_P
(Msg
: String);
406 pragma No_Return
(Error_Attr
);
407 -- Like Error_Attr, but error is posted at the start of the prefix
409 procedure Legal_Formal_Attribute
;
410 -- Common processing for attributes Definite and Has_Discriminants.
411 -- Checks that prefix is generic indefinite formal type.
413 procedure Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements
;
414 -- Common processing for attributes Max_Alignment_For_Allocation and
415 -- Max_Size_In_Storage_Elements.
418 -- Common processing for attributes Max and Min
420 procedure Standard_Attribute
(Val
: Int
);
421 -- Used to process attributes whose prefix is package Standard which
422 -- yield values of type Universal_Integer. The attribute reference
423 -- node is rewritten with an integer literal of the given value which
424 -- is marked as static.
426 procedure Uneval_Old_Msg
;
427 -- Called when Loop_Entry or Old is used in a potentially unevaluated
428 -- expression. Generates appropriate message or warning depending on
429 -- the setting of Opt.Uneval_Old (or flags in an N_Aspect_Specification
430 -- node in the aspect case).
432 procedure Unexpected_Argument
(En
: Node_Id
);
433 -- Signal unexpected attribute argument (En is the argument)
435 procedure Validate_Non_Static_Attribute_Function_Call
;
436 -- Called when processing an attribute that is a function call to a
437 -- non-static function, i.e. an attribute function that either takes
438 -- non-scalar arguments or returns a non-scalar result. Verifies that
439 -- such a call does not appear in a preelaborable context.
445 procedure Address_Checks
is
447 -- An Address attribute created by expansion is legal even when it
448 -- applies to other entity-denoting expressions.
450 if not Comes_From_Source
(N
) then
453 -- Address attribute on a protected object self reference is legal
455 elsif Is_Protected_Self_Reference
(P
) then
458 -- Address applied to an entity
460 elsif Is_Entity_Name
(P
) then
462 Ent
: constant Entity_Id
:= Entity
(P
);
465 if Is_Subprogram
(Ent
) then
466 Set_Address_Taken
(Ent
);
467 Kill_Current_Values
(Ent
);
469 -- An Address attribute is accepted when generated by the
470 -- compiler for dispatching operation, and an error is
471 -- issued once the subprogram is frozen (to avoid confusing
472 -- errors about implicit uses of Address in the dispatch
473 -- table initialization).
475 if Has_Pragma_Inline_Always
(Entity
(P
))
476 and then Comes_From_Source
(P
)
479 ("prefix of % attribute cannot be Inline_Always "
482 -- It is illegal to apply 'Address to an intrinsic
483 -- subprogram. This is now formalized in AI05-0095.
484 -- In an instance, an attempt to obtain 'Address of an
485 -- intrinsic subprogram (e.g the renaming of a predefined
486 -- operator that is an actual) raises Program_Error.
488 elsif Convention
(Ent
) = Convention_Intrinsic
then
491 Make_Raise_Program_Error
(Loc
,
492 Reason
=> PE_Address_Of_Intrinsic
));
495 Error_Msg_Name_1
:= Aname
;
497 ("cannot take % of intrinsic subprogram", N
);
500 -- Issue an error if prefix denotes an eliminated subprogram
503 Check_For_Eliminated_Subprogram
(P
, Ent
);
506 -- Object or label reference
508 elsif Is_Object
(Ent
) or else Ekind
(Ent
) = E_Label
then
509 Set_Address_Taken
(Ent
);
511 -- Deal with No_Implicit_Aliasing restriction
513 if Restriction_Check_Required
(No_Implicit_Aliasing
) then
514 if not Is_Aliased_View
(P
) then
515 Check_Restriction
(No_Implicit_Aliasing
, P
);
517 Check_No_Implicit_Aliasing
(P
);
521 -- If we have an address of an object, and the attribute
522 -- comes from source, then set the object as potentially
523 -- source modified. We do this because the resulting address
524 -- can potentially be used to modify the variable and we
525 -- might not detect this, leading to some junk warnings.
527 Set_Never_Set_In_Source
(Ent
, False);
529 -- Allow Address to be applied to task or protected type,
530 -- returning null address (what is that about???)
532 elsif (Is_Concurrent_Type
(Etype
(Ent
))
533 and then Etype
(Ent
) = Base_Type
(Ent
))
534 or else Ekind
(Ent
) = E_Package
535 or else Is_Generic_Unit
(Ent
)
538 New_Occurrence_Of
(RTE
(RE_Null_Address
), Sloc
(N
)));
540 -- Anything else is illegal
543 Error_Attr
("invalid prefix for % attribute", P
);
549 elsif Is_Object_Reference
(P
) then
552 -- Subprogram called using dot notation
554 elsif Nkind
(P
) = N_Selected_Component
555 and then Is_Subprogram
(Entity
(Selector_Name
(P
)))
559 -- What exactly are we allowing here ??? and is this properly
560 -- documented in the sinfo documentation for this node ???
562 elsif Relaxed_RM_Semantics
563 and then Nkind
(P
) = N_Attribute_Reference
567 -- All other non-entity name cases are illegal
570 Error_Attr
("invalid prefix for % attribute", P
);
574 ------------------------------
575 -- Analyze_Access_Attribute --
576 ------------------------------
578 procedure Analyze_Access_Attribute
is
579 Acc_Type
: Entity_Id
;
584 function Build_Access_Object_Type
(DT
: Entity_Id
) return Entity_Id
;
585 -- Build an access-to-object type whose designated type is DT,
586 -- and whose Ekind is appropriate to the attribute type. The
587 -- type that is constructed is returned as the result.
589 procedure Build_Access_Subprogram_Type
(P
: Node_Id
);
590 -- Build an access to subprogram whose designated type is the type of
591 -- the prefix. If prefix is overloaded, so is the node itself. The
592 -- result is stored in Acc_Type.
594 function OK_Self_Reference
return Boolean;
595 -- An access reference whose prefix is a type can legally appear
596 -- within an aggregate, where it is obtained by expansion of
597 -- a defaulted aggregate. The enclosing aggregate that contains
598 -- the self-referenced is flagged so that the self-reference can
599 -- be expanded into a reference to the target object (see exp_aggr).
601 ------------------------------
602 -- Build_Access_Object_Type --
603 ------------------------------
605 function Build_Access_Object_Type
(DT
: Entity_Id
) return Entity_Id
is
606 Typ
: constant Entity_Id
:=
608 (E_Access_Attribute_Type
, Current_Scope
, Loc
, 'A');
610 Set_Etype
(Typ
, Typ
);
612 Set_Associated_Node_For_Itype
(Typ
, N
);
613 Set_Directly_Designated_Type
(Typ
, DT
);
615 end Build_Access_Object_Type
;
617 ----------------------------------
618 -- Build_Access_Subprogram_Type --
619 ----------------------------------
621 procedure Build_Access_Subprogram_Type
(P
: Node_Id
) is
622 Index
: Interp_Index
;
625 procedure Check_Local_Access
(E
: Entity_Id
);
626 -- Deal with possible access to local subprogram. If we have such
627 -- an access, we set a flag to kill all tracked values on any call
628 -- because this access value may be passed around, and any called
629 -- code might use it to access a local procedure which clobbers a
630 -- tracked value. If the scope is a loop or block, indicate that
631 -- value tracking is disabled for the enclosing subprogram.
633 function Get_Kind
(E
: Entity_Id
) return Entity_Kind
;
634 -- Distinguish between access to regular/protected subprograms
636 ------------------------
637 -- Check_Local_Access --
638 ------------------------
640 procedure Check_Local_Access
(E
: Entity_Id
) is
642 if not Is_Library_Level_Entity
(E
) then
643 Set_Suppress_Value_Tracking_On_Call
(Current_Scope
);
644 Set_Suppress_Value_Tracking_On_Call
645 (Nearest_Dynamic_Scope
(Current_Scope
));
647 end Check_Local_Access
;
653 function Get_Kind
(E
: Entity_Id
) return Entity_Kind
is
655 if Convention
(E
) = Convention_Protected
then
656 return E_Access_Protected_Subprogram_Type
;
658 return E_Access_Subprogram_Type
;
662 -- Start of processing for Build_Access_Subprogram_Type
665 -- In the case of an access to subprogram, use the name of the
666 -- subprogram itself as the designated type. Type-checking in
667 -- this case compares the signatures of the designated types.
669 -- Note: This fragment of the tree is temporarily malformed
670 -- because the correct tree requires an E_Subprogram_Type entity
671 -- as the designated type. In most cases this designated type is
672 -- later overridden by the semantics with the type imposed by the
673 -- context during the resolution phase. In the specific case of
674 -- the expression Address!(Prim'Unrestricted_Access), used to
675 -- initialize slots of dispatch tables, this work will be done by
676 -- the expander (see Exp_Aggr).
678 -- The reason to temporarily add this kind of node to the tree
679 -- instead of a proper E_Subprogram_Type itype, is the following:
680 -- in case of errors found in the source file we report better
681 -- error messages. For example, instead of generating the
684 -- "expected access to subprogram with profile
685 -- defined at line X"
687 -- we currently generate:
689 -- "expected access to function Z defined at line X"
691 Set_Etype
(N
, Any_Type
);
693 if not Is_Overloaded
(P
) then
694 Check_Local_Access
(Entity
(P
));
696 if not Is_Intrinsic_Subprogram
(Entity
(P
)) then
697 Acc_Type
:= Create_Itype
(Get_Kind
(Entity
(P
)), N
);
698 Set_Is_Public
(Acc_Type
, False);
699 Set_Etype
(Acc_Type
, Acc_Type
);
700 Set_Convention
(Acc_Type
, Convention
(Entity
(P
)));
701 Set_Directly_Designated_Type
(Acc_Type
, Entity
(P
));
702 Set_Etype
(N
, Acc_Type
);
703 Freeze_Before
(N
, Acc_Type
);
707 Get_First_Interp
(P
, Index
, It
);
708 while Present
(It
.Nam
) loop
709 Check_Local_Access
(It
.Nam
);
711 if not Is_Intrinsic_Subprogram
(It
.Nam
) then
712 Acc_Type
:= Create_Itype
(Get_Kind
(It
.Nam
), N
);
713 Set_Is_Public
(Acc_Type
, False);
714 Set_Etype
(Acc_Type
, Acc_Type
);
715 Set_Convention
(Acc_Type
, Convention
(It
.Nam
));
716 Set_Directly_Designated_Type
(Acc_Type
, It
.Nam
);
717 Add_One_Interp
(N
, Acc_Type
, Acc_Type
);
718 Freeze_Before
(N
, Acc_Type
);
721 Get_Next_Interp
(Index
, It
);
725 -- Cannot be applied to intrinsic. Looking at the tests above,
726 -- the only way Etype (N) can still be set to Any_Type is if
727 -- Is_Intrinsic_Subprogram was True for some referenced entity.
729 if Etype
(N
) = Any_Type
then
730 Error_Attr_P
("prefix of % attribute cannot be intrinsic");
732 end Build_Access_Subprogram_Type
;
734 ----------------------
735 -- OK_Self_Reference --
736 ----------------------
738 function OK_Self_Reference
return Boolean is
745 (Nkind
(Par
) = N_Component_Association
746 or else Nkind
(Par
) in N_Subexpr
)
748 if Nkind_In
(Par
, N_Aggregate
, N_Extension_Aggregate
) then
749 if Etype
(Par
) = Typ
then
750 Set_Has_Self_Reference
(Par
);
758 -- No enclosing aggregate, or not a self-reference
761 end OK_Self_Reference
;
763 -- Start of processing for Analyze_Access_Attribute
766 Check_SPARK_05_Restriction_On_Attribute
;
769 if Nkind
(P
) = N_Character_Literal
then
771 ("prefix of % attribute cannot be enumeration literal");
774 -- Case of access to subprogram
776 if Is_Entity_Name
(P
) and then Is_Overloadable
(Entity
(P
)) then
777 if Has_Pragma_Inline_Always
(Entity
(P
)) then
779 ("prefix of % attribute cannot be Inline_Always subprogram");
781 elsif Aname
= Name_Unchecked_Access
then
782 Error_Attr
("attribute% cannot be applied to a subprogram", P
);
785 -- Issue an error if the prefix denotes an eliminated subprogram
787 Check_For_Eliminated_Subprogram
(P
, Entity
(P
));
789 -- Check for obsolescent subprogram reference
791 Check_Obsolescent_2005_Entity
(Entity
(P
), P
);
793 -- Build the appropriate subprogram type
795 Build_Access_Subprogram_Type
(P
);
797 -- For P'Access or P'Unrestricted_Access, where P is a nested
798 -- subprogram, we might be passing P to another subprogram (but we
799 -- don't check that here), which might call P. P could modify
800 -- local variables, so we need to kill current values. It is
801 -- important not to do this for library-level subprograms, because
802 -- Kill_Current_Values is very inefficient in the case of library
803 -- level packages with lots of tagged types.
805 if Is_Library_Level_Entity
(Entity
(Prefix
(N
))) then
808 -- Do not kill values on nodes initializing dispatch tables
809 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
810 -- is currently generated by the expander only for this
811 -- purpose. Done to keep the quality of warnings currently
812 -- generated by the compiler (otherwise any declaration of
813 -- a tagged type cleans constant indications from its scope).
815 elsif Nkind
(Parent
(N
)) = N_Unchecked_Type_Conversion
816 and then (Etype
(Parent
(N
)) = RTE
(RE_Prim_Ptr
)
818 Etype
(Parent
(N
)) = RTE
(RE_Size_Ptr
))
819 and then Is_Dispatching_Operation
820 (Directly_Designated_Type
(Etype
(N
)))
828 -- In the static elaboration model, treat the attribute reference
829 -- as a call for elaboration purposes. Suppress this treatment
830 -- under debug flag. In any case, we are all done.
832 if not Dynamic_Elaboration_Checks
and not Debug_Flag_Dot_UU
then
838 -- Component is an operation of a protected type
840 elsif Nkind
(P
) = N_Selected_Component
841 and then Is_Overloadable
(Entity
(Selector_Name
(P
)))
843 if Ekind
(Entity
(Selector_Name
(P
))) = E_Entry
then
844 Error_Attr_P
("prefix of % attribute must be subprogram");
847 Build_Access_Subprogram_Type
(Selector_Name
(P
));
851 -- Deal with incorrect reference to a type, but note that some
852 -- accesses are allowed: references to the current type instance,
853 -- or in Ada 2005 self-referential pointer in a default-initialized
856 if Is_Entity_Name
(P
) then
859 -- The reference may appear in an aggregate that has been expanded
860 -- into a loop. Locate scope of type definition, if any.
862 Scop
:= Current_Scope
;
863 while Ekind
(Scop
) = E_Loop
loop
864 Scop
:= Scope
(Scop
);
867 if Is_Type
(Typ
) then
869 -- OK if we are within the scope of a limited type
870 -- let's mark the component as having per object constraint
872 if Is_Anonymous_Tagged_Base
(Scop
, Typ
) then
880 Q
: Node_Id
:= Parent
(N
);
884 and then Nkind
(Q
) /= N_Component_Declaration
890 Set_Has_Per_Object_Constraint
891 (Defining_Identifier
(Q
), True);
895 if Nkind
(P
) = N_Expanded_Name
then
897 ("current instance prefix must be a direct name", P
);
900 -- If a current instance attribute appears in a component
901 -- constraint it must appear alone; other contexts (spec-
902 -- expressions, within a task body) are not subject to this
905 if not In_Spec_Expression
906 and then not Has_Completion
(Scop
)
908 Nkind_In
(Parent
(N
), N_Discriminant_Association
,
909 N_Index_Or_Discriminant_Constraint
)
912 ("current instance attribute must appear alone", N
);
915 if Is_CPP_Class
(Root_Type
(Typ
)) then
917 ("??current instance unsupported for derivations of "
918 & "'C'P'P types", N
);
921 -- OK if we are in initialization procedure for the type
922 -- in question, in which case the reference to the type
923 -- is rewritten as a reference to the current object.
925 elsif Ekind
(Scop
) = E_Procedure
926 and then Is_Init_Proc
(Scop
)
927 and then Etype
(First_Formal
(Scop
)) = Typ
930 Make_Attribute_Reference
(Loc
,
931 Prefix
=> Make_Identifier
(Loc
, Name_uInit
),
932 Attribute_Name
=> Name_Unrestricted_Access
));
936 -- OK if a task type, this test needs sharpening up ???
938 elsif Is_Task_Type
(Typ
) then
941 -- OK if self-reference in an aggregate in Ada 2005, and
942 -- the reference comes from a copied default expression.
944 -- Note that we check legality of self-reference even if the
945 -- expression comes from source, e.g. when a single component
946 -- association in an aggregate has a box association.
948 elsif Ada_Version
>= Ada_2005
949 and then OK_Self_Reference
953 -- OK if reference to current instance of a protected object
955 elsif Is_Protected_Self_Reference
(P
) then
958 -- Otherwise we have an error case
961 Error_Attr
("% attribute cannot be applied to type", P
);
967 -- If we fall through, we have a normal access to object case
969 -- Unrestricted_Access is (for now) legal wherever an allocator would
970 -- be legal, so its Etype is set to E_Allocator. The expected type
971 -- of the other attributes is a general access type, and therefore
972 -- we label them with E_Access_Attribute_Type.
974 if not Is_Overloaded
(P
) then
975 Acc_Type
:= Build_Access_Object_Type
(P_Type
);
976 Set_Etype
(N
, Acc_Type
);
980 Index
: Interp_Index
;
983 Set_Etype
(N
, Any_Type
);
984 Get_First_Interp
(P
, Index
, It
);
985 while Present
(It
.Typ
) loop
986 Acc_Type
:= Build_Access_Object_Type
(It
.Typ
);
987 Add_One_Interp
(N
, Acc_Type
, Acc_Type
);
988 Get_Next_Interp
(Index
, It
);
993 -- Special cases when we can find a prefix that is an entity name
1002 if Is_Entity_Name
(PP
) then
1005 -- If we have an access to an object, and the attribute
1006 -- comes from source, then set the object as potentially
1007 -- source modified. We do this because the resulting access
1008 -- pointer can be used to modify the variable, and we might
1009 -- not detect this, leading to some junk warnings.
1011 -- We only do this for source references, since otherwise
1012 -- we can suppress warnings, e.g. from the unrestricted
1013 -- access generated for validity checks in -gnatVa mode.
1015 if Comes_From_Source
(N
) then
1016 Set_Never_Set_In_Source
(Ent
, False);
1019 -- Mark entity as address taken, and kill current values
1021 Set_Address_Taken
(Ent
);
1022 Kill_Current_Values
(Ent
);
1025 elsif Nkind_In
(PP
, N_Selected_Component
,
1026 N_Indexed_Component
)
1036 -- Check for aliased view.. We allow a nonaliased prefix when within
1037 -- an instance because the prefix may have been a tagged formal
1038 -- object, which is defined to be aliased even when the actual
1039 -- might not be (other instance cases will have been caught in the
1040 -- generic). Similarly, within an inlined body we know that the
1041 -- attribute is legal in the original subprogram, and therefore
1042 -- legal in the expansion.
1044 if not Is_Aliased_View
(P
)
1045 and then not In_Instance
1046 and then not In_Inlined_Body
1047 and then Comes_From_Source
(N
)
1049 -- Here we have a non-aliased view. This is illegal unless we
1050 -- have the case of Unrestricted_Access, where for now we allow
1051 -- this (we will reject later if expected type is access to an
1052 -- unconstrained array with a thin pointer).
1054 -- No need for an error message on a generated access reference
1055 -- for the controlling argument in a dispatching call: error will
1056 -- be reported when resolving the call.
1058 if Aname
/= Name_Unrestricted_Access
then
1059 Error_Attr_P
("prefix of % attribute must be aliased");
1060 Check_No_Implicit_Aliasing
(P
);
1062 -- For Unrestricted_Access, record that prefix is not aliased
1063 -- to simplify legality check later on.
1066 Set_Non_Aliased_Prefix
(N
);
1069 -- If we have an aliased view, and we have Unrestricted_Access, then
1070 -- output a warning that Unchecked_Access would have been fine, and
1071 -- change the node to be Unchecked_Access.
1074 -- For now, hold off on this change ???
1078 end Analyze_Access_Attribute
;
1080 ----------------------------------
1081 -- Analyze_Attribute_Old_Result --
1082 ----------------------------------
1084 procedure Analyze_Attribute_Old_Result
1085 (Legal
: out Boolean;
1086 Spec_Id
: out Entity_Id
)
1088 procedure Check_Placement_In_Check
(Prag
: Node_Id
);
1089 -- Verify that the attribute appears within pragma Check that mimics
1092 procedure Check_Placement_In_Contract_Cases
(Prag
: Node_Id
);
1093 -- Verify that the attribute appears within a consequence of aspect
1094 -- or pragma Contract_Cases denoted by Prag.
1096 procedure Check_Placement_In_Test_Case
(Prag
: Node_Id
);
1097 -- Verify that the attribute appears within the "Ensures" argument of
1098 -- aspect or pragma Test_Case denoted by Prag.
1102 Encl_Nod
: Node_Id
) return Boolean;
1103 -- Subsidiary to Check_Placemenet_In_XXX. Determine whether arbitrary
1104 -- node Nod is within enclosing node Encl_Nod.
1106 procedure Placement_Error
;
1107 -- Emit a general error when the attributes does not appear in a
1108 -- postcondition-like aspect or pragma.
1110 ------------------------------
1111 -- Check_Placement_In_Check --
1112 ------------------------------
1114 procedure Check_Placement_In_Check
(Prag
: Node_Id
) is
1115 Args
: constant List_Id
:= Pragma_Argument_Associations
(Prag
);
1116 Nam
: constant Name_Id
:= Chars
(Get_Pragma_Arg
(First
(Args
)));
1119 -- The "Name" argument of pragma Check denotes a postcondition
1121 if Nam_In
(Nam
, Name_Post
,
1128 -- Otherwise the placement of the attribute is illegal
1133 end Check_Placement_In_Check
;
1135 ---------------------------------------
1136 -- Check_Placement_In_Contract_Cases --
1137 ---------------------------------------
1139 procedure Check_Placement_In_Contract_Cases
(Prag
: Node_Id
) is
1145 -- Obtain the argument of the aspect or pragma
1147 if Nkind
(Prag
) = N_Aspect_Specification
then
1150 Arg
:= First
(Pragma_Argument_Associations
(Prag
));
1153 Cases
:= Expression
(Arg
);
1155 if Present
(Component_Associations
(Cases
)) then
1156 CCase
:= First
(Component_Associations
(Cases
));
1157 while Present
(CCase
) loop
1159 -- Detect whether the attribute appears within the
1160 -- consequence of the current contract case.
1162 if Nkind
(CCase
) = N_Component_Association
1163 and then Is_Within
(N
, Expression
(CCase
))
1172 -- Otherwise aspect or pragma Contract_Cases is either malformed
1173 -- or the attribute does not appear within a consequence.
1176 ("attribute % must appear in the consequence of a contract case",
1178 end Check_Placement_In_Contract_Cases
;
1180 ----------------------------------
1181 -- Check_Placement_In_Test_Case --
1182 ----------------------------------
1184 procedure Check_Placement_In_Test_Case
(Prag
: Node_Id
) is
1185 Arg
: constant Node_Id
:=
1188 Arg_Nam
=> Name_Ensures
,
1189 From_Aspect
=> Nkind
(Prag
) = N_Aspect_Specification
);
1192 -- Detect whether the attribute appears within the "Ensures"
1193 -- expression of aspect or pragma Test_Case.
1195 if Present
(Arg
) and then Is_Within
(N
, Arg
) then
1200 ("attribute % must appear in the ensures expression of a "
1203 end Check_Placement_In_Test_Case
;
1211 Encl_Nod
: Node_Id
) return Boolean
1217 while Present
(Par
) loop
1218 if Par
= Encl_Nod
then
1221 -- Prevent the search from going too far
1223 elsif Is_Body_Or_Package_Declaration
(Par
) then
1227 Par
:= Parent
(Par
);
1233 ---------------------
1234 -- Placement_Error --
1235 ---------------------
1237 procedure Placement_Error
is
1239 if Aname
= Name_Old
then
1240 Error_Attr
("attribute % can only appear in postcondition", P
);
1242 -- Specialize the error message for attribute 'Result
1246 ("attribute % can only appear in postcondition of function",
1249 end Placement_Error
;
1255 Subp_Decl
: Node_Id
;
1257 -- Start of processing for Analyze_Attribute_Old_Result
1260 -- Assume that the attribute is illegal
1265 -- Traverse the parent chain to find the aspect or pragma where the
1266 -- attribute resides.
1269 while Present
(Prag
) loop
1270 if Nkind_In
(Prag
, N_Aspect_Specification
, N_Pragma
) then
1273 -- Prevent the search from going too far
1275 elsif Is_Body_Or_Package_Declaration
(Prag
) then
1279 Prag
:= Parent
(Prag
);
1282 -- The attribute is allowed to appear only in postcondition-like
1283 -- aspects or pragmas.
1285 if Nkind_In
(Prag
, N_Aspect_Specification
, N_Pragma
) then
1286 if Nkind
(Prag
) = N_Aspect_Specification
then
1287 Prag_Nam
:= Chars
(Identifier
(Prag
));
1289 Prag_Nam
:= Pragma_Name
(Prag
);
1292 if Prag_Nam
= Name_Check
then
1293 Check_Placement_In_Check
(Prag
);
1295 elsif Prag_Nam
= Name_Contract_Cases
then
1296 Check_Placement_In_Contract_Cases
(Prag
);
1298 elsif Nam_In
(Prag_Nam
, Name_Post
,
1305 elsif Prag_Nam
= Name_Test_Case
then
1306 Check_Placement_In_Test_Case
(Prag
);
1313 -- Otherwise the placement of the attribute is illegal
1320 -- Find the related subprogram subject to the aspect or pragma
1322 if Nkind
(Prag
) = N_Aspect_Specification
then
1323 Subp_Decl
:= Parent
(Prag
);
1325 Subp_Decl
:= Find_Related_Subprogram_Or_Body
(Prag
);
1328 -- The aspect or pragma where the attribute resides should be
1329 -- associated with a subprogram declaration or a body. If this is not
1330 -- the case, then the aspect or pragma is illegal. Return as analysis
1331 -- cannot be carried out.
1333 if not Nkind_In
(Subp_Decl
, N_Abstract_Subprogram_Declaration
,
1334 N_Entry_Declaration
,
1335 N_Generic_Subprogram_Declaration
,
1337 N_Subprogram_Body_Stub
,
1338 N_Subprogram_Declaration
)
1343 -- If we get here, then the attribute is legal
1346 Spec_Id
:= Corresponding_Spec_Of
(Subp_Decl
);
1347 end Analyze_Attribute_Old_Result
;
1349 ---------------------------------
1350 -- Bad_Attribute_For_Predicate --
1351 ---------------------------------
1353 procedure Bad_Attribute_For_Predicate
is
1355 if Is_Scalar_Type
(P_Type
)
1356 and then Comes_From_Source
(N
)
1358 Error_Msg_Name_1
:= Aname
;
1359 Bad_Predicated_Subtype_Use
1360 ("type& has predicates, attribute % not allowed", N
, P_Type
);
1362 end Bad_Attribute_For_Predicate
;
1364 --------------------------------
1365 -- Check_Array_Or_Scalar_Type --
1366 --------------------------------
1368 procedure Check_Array_Or_Scalar_Type
is
1372 -- Dimension number for array attributes
1375 -- Case of string literal or string literal subtype. These cases
1376 -- cannot arise from legal Ada code, but the expander is allowed
1377 -- to generate them. They require special handling because string
1378 -- literal subtypes do not have standard bounds (the whole idea
1379 -- of these subtypes is to avoid having to generate the bounds)
1381 if Ekind
(P_Type
) = E_String_Literal_Subtype
then
1382 Set_Etype
(N
, Etype
(First_Index
(P_Base_Type
)));
1387 elsif Is_Scalar_Type
(P_Type
) then
1390 if Present
(E1
) then
1391 Error_Attr
("invalid argument in % attribute", E1
);
1393 Set_Etype
(N
, P_Base_Type
);
1397 -- The following is a special test to allow 'First to apply to
1398 -- private scalar types if the attribute comes from generated
1399 -- code. This occurs in the case of Normalize_Scalars code.
1401 elsif Is_Private_Type
(P_Type
)
1402 and then Present
(Full_View
(P_Type
))
1403 and then Is_Scalar_Type
(Full_View
(P_Type
))
1404 and then not Comes_From_Source
(N
)
1406 Set_Etype
(N
, Implementation_Base_Type
(P_Type
));
1408 -- Array types other than string literal subtypes handled above
1413 -- We know prefix is an array type, or the name of an array
1414 -- object, and that the expression, if present, is static
1415 -- and within the range of the dimensions of the type.
1417 pragma Assert
(Is_Array_Type
(P_Type
));
1418 Index
:= First_Index
(P_Base_Type
);
1422 -- First dimension assumed
1424 Set_Etype
(N
, Base_Type
(Etype
(Index
)));
1427 D
:= UI_To_Int
(Intval
(E1
));
1429 for J
in 1 .. D
- 1 loop
1433 Set_Etype
(N
, Base_Type
(Etype
(Index
)));
1434 Set_Etype
(E1
, Standard_Integer
);
1437 end Check_Array_Or_Scalar_Type
;
1439 ----------------------
1440 -- Check_Array_Type --
1441 ----------------------
1443 procedure Check_Array_Type
is
1445 -- Dimension number for array attributes
1448 -- If the type is a string literal type, then this must be generated
1449 -- internally, and no further check is required on its legality.
1451 if Ekind
(P_Type
) = E_String_Literal_Subtype
then
1454 -- If the type is a composite, it is an illegal aggregate, no point
1457 elsif P_Type
= Any_Composite
then
1458 raise Bad_Attribute
;
1461 -- Normal case of array type or subtype
1463 Check_Either_E0_Or_E1
;
1466 if Is_Array_Type
(P_Type
) then
1467 if not Is_Constrained
(P_Type
)
1468 and then Is_Entity_Name
(P
)
1469 and then Is_Type
(Entity
(P
))
1471 -- Note: we do not call Error_Attr here, since we prefer to
1472 -- continue, using the relevant index type of the array,
1473 -- even though it is unconstrained. This gives better error
1474 -- recovery behavior.
1476 Error_Msg_Name_1
:= Aname
;
1478 ("prefix for % attribute must be constrained array", P
);
1481 -- The attribute reference freezes the type, and thus the
1482 -- component type, even if the attribute may not depend on the
1483 -- component. Diagnose arrays with incomplete components now.
1484 -- If the prefix is an access to array, this does not freeze
1485 -- the designated type.
1487 if Nkind
(P
) /= N_Explicit_Dereference
then
1488 Check_Fully_Declared
(Component_Type
(P_Type
), P
);
1491 D
:= Number_Dimensions
(P_Type
);
1494 if Is_Private_Type
(P_Type
) then
1495 Error_Attr_P
("prefix for % attribute may not be private type");
1497 elsif Is_Access_Type
(P_Type
)
1498 and then Is_Array_Type
(Designated_Type
(P_Type
))
1499 and then Is_Entity_Name
(P
)
1500 and then Is_Type
(Entity
(P
))
1502 Error_Attr_P
("prefix of % attribute cannot be access type");
1504 elsif Attr_Id
= Attribute_First
1506 Attr_Id
= Attribute_Last
1508 Error_Attr
("invalid prefix for % attribute", P
);
1511 Error_Attr_P
("prefix for % attribute must be array");
1515 if Present
(E1
) then
1516 Resolve
(E1
, Any_Integer
);
1517 Set_Etype
(E1
, Standard_Integer
);
1519 if not Is_OK_Static_Expression
(E1
)
1520 or else Raises_Constraint_Error
(E1
)
1522 Flag_Non_Static_Expr
1523 ("expression for dimension must be static!", E1
);
1526 elsif UI_To_Int
(Expr_Value
(E1
)) > D
1527 or else UI_To_Int
(Expr_Value
(E1
)) < 1
1529 Error_Attr
("invalid dimension number for array type", E1
);
1533 if (Style_Check
and Style_Check_Array_Attribute_Index
)
1534 and then Comes_From_Source
(N
)
1536 Style
.Check_Array_Attribute_Index
(N
, E1
, D
);
1538 end Check_Array_Type
;
1540 -------------------------
1541 -- Check_Asm_Attribute --
1542 -------------------------
1544 procedure Check_Asm_Attribute
is
1549 -- Check first argument is static string expression
1551 Analyze_And_Resolve
(E1
, Standard_String
);
1553 if Etype
(E1
) = Any_Type
then
1556 elsif not Is_OK_Static_Expression
(E1
) then
1557 Flag_Non_Static_Expr
1558 ("constraint argument must be static string expression!", E1
);
1562 -- Check second argument is right type
1564 Analyze_And_Resolve
(E2
, Entity
(P
));
1566 -- Note: that is all we need to do, we don't need to check
1567 -- that it appears in a correct context. The Ada type system
1568 -- will do that for us.
1570 end Check_Asm_Attribute
;
1572 ---------------------
1573 -- Check_Component --
1574 ---------------------
1576 procedure Check_Component
is
1580 if Nkind
(P
) /= N_Selected_Component
1582 (Ekind
(Entity
(Selector_Name
(P
))) /= E_Component
1584 Ekind
(Entity
(Selector_Name
(P
))) /= E_Discriminant
)
1586 Error_Attr_P
("prefix for % attribute must be selected component");
1588 end Check_Component
;
1590 ------------------------------------
1591 -- Check_Decimal_Fixed_Point_Type --
1592 ------------------------------------
1594 procedure Check_Decimal_Fixed_Point_Type
is
1598 if not Is_Decimal_Fixed_Point_Type
(P_Type
) then
1599 Error_Attr_P
("prefix of % attribute must be decimal type");
1601 end Check_Decimal_Fixed_Point_Type
;
1603 -----------------------
1604 -- Check_Dereference --
1605 -----------------------
1607 procedure Check_Dereference
is
1610 -- Case of a subtype mark
1612 if Is_Entity_Name
(P
) and then Is_Type
(Entity
(P
)) then
1616 -- Case of an expression
1620 if Is_Access_Type
(P_Type
) then
1622 -- If there is an implicit dereference, then we must freeze the
1623 -- designated type of the access type, since the type of the
1624 -- referenced array is this type (see AI95-00106).
1626 -- As done elsewhere, freezing must not happen when pre-analyzing
1627 -- a pre- or postcondition or a default value for an object or for
1628 -- a formal parameter.
1630 if not In_Spec_Expression
then
1631 Freeze_Before
(N
, Designated_Type
(P_Type
));
1635 Make_Explicit_Dereference
(Sloc
(P
),
1636 Prefix
=> Relocate_Node
(P
)));
1638 Analyze_And_Resolve
(P
);
1639 P_Type
:= Etype
(P
);
1641 if P_Type
= Any_Type
then
1642 raise Bad_Attribute
;
1645 P_Base_Type
:= Base_Type
(P_Type
);
1647 end Check_Dereference
;
1649 -------------------------
1650 -- Check_Discrete_Type --
1651 -------------------------
1653 procedure Check_Discrete_Type
is
1657 if not Is_Discrete_Type
(P_Type
) then
1658 Error_Attr_P
("prefix of % attribute must be discrete type");
1660 end Check_Discrete_Type
;
1666 procedure Check_E0
is
1668 if Present
(E1
) then
1669 Unexpected_Argument
(E1
);
1677 procedure Check_E1
is
1679 Check_Either_E0_Or_E1
;
1683 -- Special-case attributes that are functions and that appear as
1684 -- the prefix of another attribute. Error is posted on parent.
1686 if Nkind
(Parent
(N
)) = N_Attribute_Reference
1687 and then Nam_In
(Attribute_Name
(Parent
(N
)), Name_Address
,
1691 Error_Msg_Name_1
:= Attribute_Name
(Parent
(N
));
1692 Error_Msg_N
("illegal prefix for % attribute", Parent
(N
));
1693 Set_Etype
(Parent
(N
), Any_Type
);
1694 Set_Entity
(Parent
(N
), Any_Type
);
1695 raise Bad_Attribute
;
1698 Error_Attr
("missing argument for % attribute", N
);
1707 procedure Check_E2
is
1710 Error_Attr
("missing arguments for % attribute (2 required)", N
);
1712 Error_Attr
("missing argument for % attribute (2 required)", N
);
1716 ---------------------------
1717 -- Check_Either_E0_Or_E1 --
1718 ---------------------------
1720 procedure Check_Either_E0_Or_E1
is
1722 if Present
(E2
) then
1723 Unexpected_Argument
(E2
);
1725 end Check_Either_E0_Or_E1
;
1727 ----------------------
1728 -- Check_Enum_Image --
1729 ----------------------
1731 procedure Check_Enum_Image
is
1735 -- When an enumeration type appears in an attribute reference, all
1736 -- literals of the type are marked as referenced. This must only be
1737 -- done if the attribute reference appears in the current source.
1738 -- Otherwise the information on references may differ between a
1739 -- normal compilation and one that performs inlining.
1741 if Is_Enumeration_Type
(P_Base_Type
)
1742 and then In_Extended_Main_Code_Unit
(N
)
1744 Lit
:= First_Literal
(P_Base_Type
);
1745 while Present
(Lit
) loop
1746 Set_Referenced
(Lit
);
1750 end Check_Enum_Image
;
1752 ----------------------------
1753 -- Check_First_Last_Valid --
1754 ----------------------------
1756 procedure Check_First_Last_Valid
is
1758 Check_Discrete_Type
;
1760 -- Freeze the subtype now, so that the following test for predicates
1761 -- works (we set the predicates stuff up at freeze time)
1763 Insert_Actions
(N
, Freeze_Entity
(P_Type
, P
));
1765 -- Now test for dynamic predicate
1767 if Has_Predicates
(P_Type
)
1768 and then not (Has_Static_Predicate
(P_Type
))
1771 ("prefix of % attribute may not have dynamic predicate");
1774 -- Check non-static subtype
1776 if not Is_OK_Static_Subtype
(P_Type
) then
1777 Error_Attr_P
("prefix of % attribute must be a static subtype");
1780 -- Test case for no values
1782 if Expr_Value
(Type_Low_Bound
(P_Type
)) >
1783 Expr_Value
(Type_High_Bound
(P_Type
))
1784 or else (Has_Predicates
(P_Type
)
1786 Is_Empty_List
(Static_Discrete_Predicate
(P_Type
)))
1789 ("prefix of % attribute must be subtype with at least one "
1792 end Check_First_Last_Valid
;
1794 ----------------------------
1795 -- Check_Fixed_Point_Type --
1796 ----------------------------
1798 procedure Check_Fixed_Point_Type
is
1802 if not Is_Fixed_Point_Type
(P_Type
) then
1803 Error_Attr_P
("prefix of % attribute must be fixed point type");
1805 end Check_Fixed_Point_Type
;
1807 ------------------------------
1808 -- Check_Fixed_Point_Type_0 --
1809 ------------------------------
1811 procedure Check_Fixed_Point_Type_0
is
1813 Check_Fixed_Point_Type
;
1815 end Check_Fixed_Point_Type_0
;
1817 -------------------------------
1818 -- Check_Floating_Point_Type --
1819 -------------------------------
1821 procedure Check_Floating_Point_Type
is
1825 if not Is_Floating_Point_Type
(P_Type
) then
1826 Error_Attr_P
("prefix of % attribute must be float type");
1828 end Check_Floating_Point_Type
;
1830 ---------------------------------
1831 -- Check_Floating_Point_Type_0 --
1832 ---------------------------------
1834 procedure Check_Floating_Point_Type_0
is
1836 Check_Floating_Point_Type
;
1838 end Check_Floating_Point_Type_0
;
1840 ---------------------------------
1841 -- Check_Floating_Point_Type_1 --
1842 ---------------------------------
1844 procedure Check_Floating_Point_Type_1
is
1846 Check_Floating_Point_Type
;
1848 end Check_Floating_Point_Type_1
;
1850 ---------------------------------
1851 -- Check_Floating_Point_Type_2 --
1852 ---------------------------------
1854 procedure Check_Floating_Point_Type_2
is
1856 Check_Floating_Point_Type
;
1858 end Check_Floating_Point_Type_2
;
1860 ------------------------
1861 -- Check_Integer_Type --
1862 ------------------------
1864 procedure Check_Integer_Type
is
1868 if not Is_Integer_Type
(P_Type
) then
1869 Error_Attr_P
("prefix of % attribute must be integer type");
1871 end Check_Integer_Type
;
1873 --------------------------------
1874 -- Check_Modular_Integer_Type --
1875 --------------------------------
1877 procedure Check_Modular_Integer_Type
is
1881 if not Is_Modular_Integer_Type
(P_Type
) then
1883 ("prefix of % attribute must be modular integer type");
1885 end Check_Modular_Integer_Type
;
1887 ------------------------
1888 -- Check_Not_CPP_Type --
1889 ------------------------
1891 procedure Check_Not_CPP_Type
is
1893 if Is_Tagged_Type
(Etype
(P
))
1894 and then Convention
(Etype
(P
)) = Convention_CPP
1895 and then Is_CPP_Class
(Root_Type
(Etype
(P
)))
1898 ("invalid use of % attribute with 'C'P'P tagged type");
1900 end Check_Not_CPP_Type
;
1902 -------------------------------
1903 -- Check_Not_Incomplete_Type --
1904 -------------------------------
1906 procedure Check_Not_Incomplete_Type
is
1911 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1912 -- dereference we have to check wrong uses of incomplete types
1913 -- (other wrong uses are checked at their freezing point).
1915 -- In Ada 2012, incomplete types can appear in subprogram
1916 -- profiles, but formals with incomplete types cannot be the
1917 -- prefix of attributes.
1919 -- Example 1: Limited-with
1921 -- limited with Pkg;
1923 -- type Acc is access Pkg.T;
1925 -- S : Integer := X.all'Size; -- ERROR
1928 -- Example 2: Tagged incomplete
1930 -- type T is tagged;
1931 -- type Acc is access all T;
1933 -- S : constant Integer := X.all'Size; -- ERROR
1934 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1936 if Ada_Version
>= Ada_2005
1937 and then Nkind
(P
) = N_Explicit_Dereference
1940 while Nkind
(E
) = N_Explicit_Dereference
loop
1946 if From_Limited_With
(Typ
) then
1948 ("prefix of % attribute cannot be an incomplete type");
1950 -- If the prefix is an access type check the designated type
1952 elsif Is_Access_Type
(Typ
)
1953 and then Nkind
(P
) = N_Explicit_Dereference
1955 Typ
:= Directly_Designated_Type
(Typ
);
1958 if Is_Class_Wide_Type
(Typ
) then
1959 Typ
:= Root_Type
(Typ
);
1962 -- A legal use of a shadow entity occurs only when the unit where
1963 -- the non-limited view resides is imported via a regular with
1964 -- clause in the current body. Such references to shadow entities
1965 -- may occur in subprogram formals.
1967 if Is_Incomplete_Type
(Typ
)
1968 and then From_Limited_With
(Typ
)
1969 and then Present
(Non_Limited_View
(Typ
))
1970 and then Is_Legal_Shadow_Entity_In_Body
(Typ
)
1972 Typ
:= Non_Limited_View
(Typ
);
1975 -- If still incomplete, it can be a local incomplete type, or a
1976 -- limited view whose scope is also a limited view.
1978 if Ekind
(Typ
) = E_Incomplete_Type
then
1979 if not From_Limited_With
(Typ
)
1980 and then No
(Full_View
(Typ
))
1983 ("prefix of % attribute cannot be an incomplete type");
1985 -- The limited view may be available indirectly through
1986 -- an intermediate unit. If the non-limited view is available
1987 -- the attribute reference is legal.
1989 elsif From_Limited_With
(Typ
)
1991 (No
(Non_Limited_View
(Typ
))
1992 or else Is_Incomplete_Type
(Non_Limited_View
(Typ
)))
1995 ("prefix of % attribute cannot be an incomplete type");
1999 -- Ada 2012 : formals in bodies may be incomplete, but no attribute
2002 elsif Is_Entity_Name
(P
)
2003 and then Is_Formal
(Entity
(P
))
2004 and then Is_Incomplete_Type
(Etype
(Etype
(P
)))
2007 ("prefix of % attribute cannot be an incomplete type");
2010 if not Is_Entity_Name
(P
)
2011 or else not Is_Type
(Entity
(P
))
2012 or else In_Spec_Expression
2016 Check_Fully_Declared
(P_Type
, P
);
2018 end Check_Not_Incomplete_Type
;
2020 ----------------------------
2021 -- Check_Object_Reference --
2022 ----------------------------
2024 procedure Check_Object_Reference
(P
: Node_Id
) is
2028 -- If we need an object, and we have a prefix that is the name of
2029 -- a function entity, convert it into a function call.
2031 if Is_Entity_Name
(P
)
2032 and then Ekind
(Entity
(P
)) = E_Function
2034 Rtyp
:= Etype
(Entity
(P
));
2037 Make_Function_Call
(Sloc
(P
),
2038 Name
=> Relocate_Node
(P
)));
2040 Analyze_And_Resolve
(P
, Rtyp
);
2042 -- Otherwise we must have an object reference
2044 elsif not Is_Object_Reference
(P
) then
2045 Error_Attr_P
("prefix of % attribute must be object");
2047 end Check_Object_Reference
;
2049 ----------------------------
2050 -- Check_PolyORB_Attribute --
2051 ----------------------------
2053 procedure Check_PolyORB_Attribute
is
2055 Validate_Non_Static_Attribute_Function_Call
;
2060 if Get_PCS_Name
/= Name_PolyORB_DSA
then
2062 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N
);
2064 end Check_PolyORB_Attribute
;
2066 ------------------------
2067 -- Check_Program_Unit --
2068 ------------------------
2070 procedure Check_Program_Unit
is
2072 if Is_Entity_Name
(P
) then
2074 K
: constant Entity_Kind
:= Ekind
(Entity
(P
));
2075 T
: constant Entity_Id
:= Etype
(Entity
(P
));
2078 if K
in Subprogram_Kind
2079 or else K
in Task_Kind
2080 or else K
in Protected_Kind
2081 or else K
= E_Package
2082 or else K
in Generic_Unit_Kind
2083 or else (K
= E_Variable
2087 Is_Protected_Type
(T
)))
2094 Error_Attr_P
("prefix of % attribute must be program unit");
2095 end Check_Program_Unit
;
2097 ---------------------
2098 -- Check_Real_Type --
2099 ---------------------
2101 procedure Check_Real_Type
is
2105 if not Is_Real_Type
(P_Type
) then
2106 Error_Attr_P
("prefix of % attribute must be real type");
2108 end Check_Real_Type
;
2110 -----------------------
2111 -- Check_Scalar_Type --
2112 -----------------------
2114 procedure Check_Scalar_Type
is
2118 if not Is_Scalar_Type
(P_Type
) then
2119 Error_Attr_P
("prefix of % attribute must be scalar type");
2121 end Check_Scalar_Type
;
2123 ------------------------------------------
2124 -- Check_SPARK_05_Restriction_On_Attribute --
2125 ------------------------------------------
2127 procedure Check_SPARK_05_Restriction_On_Attribute
is
2129 Error_Msg_Name_1
:= Aname
;
2130 Check_SPARK_05_Restriction
("attribute % is not allowed", P
);
2131 end Check_SPARK_05_Restriction_On_Attribute
;
2133 ---------------------------
2134 -- Check_Standard_Prefix --
2135 ---------------------------
2137 procedure Check_Standard_Prefix
is
2141 if Nkind
(P
) /= N_Identifier
or else Chars
(P
) /= Name_Standard
then
2142 Error_Attr
("only allowed prefix for % attribute is Standard", P
);
2144 end Check_Standard_Prefix
;
2146 ----------------------------
2147 -- Check_Stream_Attribute --
2148 ----------------------------
2150 procedure Check_Stream_Attribute
(Nam
: TSS_Name_Type
) is
2154 In_Shared_Var_Procs
: Boolean;
2155 -- True when compiling System.Shared_Storage.Shared_Var_Procs body.
2156 -- For this runtime package (always compiled in GNAT mode), we allow
2157 -- stream attributes references for limited types for the case where
2158 -- shared passive objects are implemented using stream attributes,
2159 -- which is the default in GNAT's persistent storage implementation.
2162 Validate_Non_Static_Attribute_Function_Call
;
2164 -- With the exception of 'Input, Stream attributes are procedures,
2165 -- and can only appear at the position of procedure calls. We check
2166 -- for this here, before they are rewritten, to give a more precise
2169 if Nam
= TSS_Stream_Input
then
2172 elsif Is_List_Member
(N
)
2173 and then not Nkind_In
(Parent
(N
), N_Procedure_Call_Statement
,
2180 ("invalid context for attribute%, which is a procedure", N
);
2184 Btyp
:= Implementation_Base_Type
(P_Type
);
2186 -- Stream attributes not allowed on limited types unless the
2187 -- attribute reference was generated by the expander (in which
2188 -- case the underlying type will be used, as described in Sinfo),
2189 -- or the attribute was specified explicitly for the type itself
2190 -- or one of its ancestors (taking visibility rules into account if
2191 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
2192 -- (with no visibility restriction).
2195 Gen_Body
: constant Node_Id
:= Enclosing_Generic_Body
(N
);
2197 if Present
(Gen_Body
) then
2198 In_Shared_Var_Procs
:=
2199 Is_RTE
(Corresponding_Spec
(Gen_Body
), RE_Shared_Var_Procs
);
2201 In_Shared_Var_Procs
:= False;
2205 if (Comes_From_Source
(N
)
2206 and then not (In_Shared_Var_Procs
or In_Instance
))
2207 and then not Stream_Attribute_Available
(P_Type
, Nam
)
2208 and then not Has_Rep_Pragma
(Btyp
, Name_Stream_Convert
)
2210 Error_Msg_Name_1
:= Aname
;
2212 if Is_Limited_Type
(P_Type
) then
2214 ("limited type& has no% attribute", P
, P_Type
);
2215 Explain_Limited_Type
(P_Type
, P
);
2218 ("attribute% for type& is not available", P
, P_Type
);
2222 -- Check for no stream operations allowed from No_Tagged_Streams
2224 if Is_Tagged_Type
(P_Type
)
2225 and then Present
(No_Tagged_Streams_Pragma
(P_Type
))
2227 Error_Msg_Sloc
:= Sloc
(No_Tagged_Streams_Pragma
(P_Type
));
2229 ("no stream operations for & (No_Tagged_Streams #)", N
, P_Type
);
2233 -- Check restriction violations
2235 -- First check the No_Streams restriction, which prohibits the use
2236 -- of explicit stream attributes in the source program. We do not
2237 -- prevent the occurrence of stream attributes in generated code,
2238 -- for instance those generated implicitly for dispatching purposes.
2240 if Comes_From_Source
(N
) then
2241 Check_Restriction
(No_Streams
, P
);
2244 -- AI05-0057: if restriction No_Default_Stream_Attributes is active,
2245 -- it is illegal to use a predefined elementary type stream attribute
2246 -- either by itself, or more importantly as part of the attribute
2247 -- subprogram for a composite type. However, if the broader
2248 -- restriction No_Streams is active, stream operations are not
2249 -- generated, and there is no error.
2251 if Restriction_Active
(No_Default_Stream_Attributes
)
2252 and then not Restriction_Active
(No_Streams
)
2258 if Nam
= TSS_Stream_Input
2260 Nam
= TSS_Stream_Read
2263 Type_Without_Stream_Operation
(P_Type
, TSS_Stream_Read
);
2266 Type_Without_Stream_Operation
(P_Type
, TSS_Stream_Write
);
2270 Check_Restriction
(No_Default_Stream_Attributes
, N
);
2273 ("missing user-defined Stream Read or Write for type&",
2275 if not Is_Elementary_Type
(P_Type
) then
2277 ("\which is a component of type&", N
, P_Type
);
2283 -- Check special case of Exception_Id and Exception_Occurrence which
2284 -- are not allowed for restriction No_Exception_Registration.
2286 if Restriction_Check_Required
(No_Exception_Registration
)
2287 and then (Is_RTE
(P_Type
, RE_Exception_Id
)
2289 Is_RTE
(P_Type
, RE_Exception_Occurrence
))
2291 Check_Restriction
(No_Exception_Registration
, P
);
2294 -- Here we must check that the first argument is an access type
2295 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
2297 Analyze_And_Resolve
(E1
);
2300 -- Note: the double call to Root_Type here is needed because the
2301 -- root type of a class-wide type is the corresponding type (e.g.
2302 -- X for X'Class, and we really want to go to the root.)
2304 if not Is_Access_Type
(Etyp
)
2305 or else Root_Type
(Root_Type
(Designated_Type
(Etyp
))) /=
2306 RTE
(RE_Root_Stream_Type
)
2309 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1
);
2312 -- Check that the second argument is of the right type if there is
2313 -- one (the Input attribute has only one argument so this is skipped)
2315 if Present
(E2
) then
2318 if Nam
= TSS_Stream_Read
2319 and then not Is_OK_Variable_For_Out_Formal
(E2
)
2322 ("second argument of % attribute must be a variable", E2
);
2325 Resolve
(E2
, P_Type
);
2329 end Check_Stream_Attribute
;
2331 -------------------------
2332 -- Check_System_Prefix --
2333 -------------------------
2335 procedure Check_System_Prefix
is
2337 if Nkind
(P
) /= N_Identifier
or else Chars
(P
) /= Name_System
then
2338 Error_Attr
("only allowed prefix for % attribute is System", P
);
2340 end Check_System_Prefix
;
2342 -----------------------
2343 -- Check_Task_Prefix --
2344 -----------------------
2346 procedure Check_Task_Prefix
is
2350 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
2351 -- task interface class-wide types.
2353 if Is_Task_Type
(Etype
(P
))
2354 or else (Is_Access_Type
(Etype
(P
))
2355 and then Is_Task_Type
(Designated_Type
(Etype
(P
))))
2356 or else (Ada_Version
>= Ada_2005
2357 and then Ekind
(Etype
(P
)) = E_Class_Wide_Type
2358 and then Is_Interface
(Etype
(P
))
2359 and then Is_Task_Interface
(Etype
(P
)))
2364 if Ada_Version
>= Ada_2005
then
2366 ("prefix of % attribute must be a task or a task " &
2367 "interface class-wide object");
2370 Error_Attr_P
("prefix of % attribute must be a task");
2373 end Check_Task_Prefix
;
2379 -- The possibilities are an entity name denoting a type, or an
2380 -- attribute reference that denotes a type (Base or Class). If
2381 -- the type is incomplete, replace it with its full view.
2383 procedure Check_Type
is
2385 if not Is_Entity_Name
(P
)
2386 or else not Is_Type
(Entity
(P
))
2388 Error_Attr_P
("prefix of % attribute must be a type");
2390 elsif Is_Protected_Self_Reference
(P
) then
2392 ("prefix of % attribute denotes current instance "
2393 & "(RM 9.4(21/2))");
2395 elsif Ekind
(Entity
(P
)) = E_Incomplete_Type
2396 and then Present
(Full_View
(Entity
(P
)))
2398 P_Type
:= Full_View
(Entity
(P
));
2399 Set_Entity
(P
, P_Type
);
2403 ---------------------
2404 -- Check_Unit_Name --
2405 ---------------------
2407 procedure Check_Unit_Name
(Nod
: Node_Id
) is
2409 if Nkind
(Nod
) = N_Identifier
then
2412 elsif Nkind_In
(Nod
, N_Selected_Component
, N_Expanded_Name
) then
2413 Check_Unit_Name
(Prefix
(Nod
));
2415 if Nkind
(Selector_Name
(Nod
)) = N_Identifier
then
2420 Error_Attr
("argument for % attribute must be unit name", P
);
2421 end Check_Unit_Name
;
2427 procedure Error_Attr
is
2429 Set_Etype
(N
, Any_Type
);
2430 Set_Entity
(N
, Any_Type
);
2431 raise Bad_Attribute
;
2434 procedure Error_Attr
(Msg
: String; Error_Node
: Node_Id
) is
2436 Error_Msg_Name_1
:= Aname
;
2437 Error_Msg_N
(Msg
, Error_Node
);
2445 procedure Error_Attr_P
(Msg
: String) is
2447 Error_Msg_Name_1
:= Aname
;
2448 Error_Msg_F
(Msg
, P
);
2452 ----------------------------
2453 -- Legal_Formal_Attribute --
2454 ----------------------------
2456 procedure Legal_Formal_Attribute
is
2460 if not Is_Entity_Name
(P
)
2461 or else not Is_Type
(Entity
(P
))
2463 Error_Attr_P
("prefix of % attribute must be generic type");
2465 elsif Is_Generic_Actual_Type
(Entity
(P
))
2467 or else In_Inlined_Body
2471 elsif Is_Generic_Type
(Entity
(P
)) then
2472 if not Is_Indefinite_Subtype
(Entity
(P
)) then
2474 ("prefix of % attribute must be indefinite generic type");
2479 ("prefix of % attribute must be indefinite generic type");
2482 Set_Etype
(N
, Standard_Boolean
);
2483 end Legal_Formal_Attribute
;
2485 ---------------------------------------------------------------
2486 -- Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements --
2487 ---------------------------------------------------------------
2489 procedure Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements
is
2493 Check_Not_Incomplete_Type
;
2494 Set_Etype
(N
, Universal_Integer
);
2495 end Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements
;
2501 procedure Min_Max
is
2505 Resolve
(E1
, P_Base_Type
);
2506 Resolve
(E2
, P_Base_Type
);
2507 Set_Etype
(N
, P_Base_Type
);
2509 -- Check for comparison on unordered enumeration type
2511 if Bad_Unordered_Enumeration_Reference
(N
, P_Base_Type
) then
2512 Error_Msg_Sloc
:= Sloc
(P_Base_Type
);
2514 ("comparison on unordered enumeration type& declared#?U?",
2519 ------------------------
2520 -- Standard_Attribute --
2521 ------------------------
2523 procedure Standard_Attribute
(Val
: Int
) is
2525 Check_Standard_Prefix
;
2526 Rewrite
(N
, Make_Integer_Literal
(Loc
, Val
));
2528 Set_Is_Static_Expression
(N
, True);
2529 end Standard_Attribute
;
2531 --------------------
2532 -- Uneval_Old_Msg --
2533 --------------------
2535 procedure Uneval_Old_Msg
is
2536 Uneval_Old_Setting
: Character;
2540 -- If from aspect, then Uneval_Old_Setting comes from flags in the
2541 -- N_Aspect_Specification node that corresponds to the attribute.
2543 -- First find the pragma in which we appear (note that at this stage,
2544 -- even if we appeared originally within an aspect specification, we
2545 -- are now within the corresponding pragma).
2549 Prag
:= Parent
(Prag
);
2550 exit when No
(Prag
) or else Nkind
(Prag
) = N_Pragma
;
2553 if Present
(Prag
) then
2554 if Uneval_Old_Accept
(Prag
) then
2555 Uneval_Old_Setting
:= 'A';
2556 elsif Uneval_Old_Warn
(Prag
) then
2557 Uneval_Old_Setting
:= 'W';
2559 Uneval_Old_Setting
:= 'E';
2562 -- If we did not find the pragma, that's odd, just use the setting
2563 -- from Opt.Uneval_Old. Perhaps this is due to a previous error?
2566 Uneval_Old_Setting
:= Opt
.Uneval_Old
;
2569 -- Processing depends on the setting of Uneval_Old
2571 case Uneval_Old_Setting
is
2574 ("prefix of attribute % that is potentially "
2575 & "unevaluated must denote an entity");
2578 Error_Msg_Name_1
:= Aname
;
2580 ("??prefix of attribute % appears in potentially "
2581 & "unevaluated context, exception may be raised", P
);
2587 raise Program_Error
;
2591 -------------------------
2592 -- Unexpected Argument --
2593 -------------------------
2595 procedure Unexpected_Argument
(En
: Node_Id
) is
2597 Error_Attr
("unexpected argument for % attribute", En
);
2598 end Unexpected_Argument
;
2600 -------------------------------------------------
2601 -- Validate_Non_Static_Attribute_Function_Call --
2602 -------------------------------------------------
2604 -- This function should be moved to Sem_Dist ???
2606 procedure Validate_Non_Static_Attribute_Function_Call
is
2608 if In_Preelaborated_Unit
2609 and then not In_Subprogram_Or_Concurrent_Unit
2611 Flag_Non_Static_Expr
2612 ("non-static function call in preelaborated unit!", N
);
2614 end Validate_Non_Static_Attribute_Function_Call
;
2616 -- Start of processing for Analyze_Attribute
2619 -- Immediate return if unrecognized attribute (already diagnosed
2620 -- by parser, so there is nothing more that we need to do)
2622 if not Is_Attribute_Name
(Aname
) then
2623 raise Bad_Attribute
;
2626 -- Deal with Ada 83 issues
2628 if Comes_From_Source
(N
) then
2629 if not Attribute_83
(Attr_Id
) then
2630 if Ada_Version
= Ada_83
and then Comes_From_Source
(N
) then
2631 Error_Msg_Name_1
:= Aname
;
2632 Error_Msg_N
("(Ada 83) attribute% is not standard??", N
);
2635 if Attribute_Impl_Def
(Attr_Id
) then
2636 Check_Restriction
(No_Implementation_Attributes
, N
);
2641 -- Deal with Ada 2005 attributes that are implementation attributes
2642 -- because they appear in a version of Ada before Ada 2005, and
2643 -- similarly for Ada 2012 attributes appearing in an earlier version.
2645 if (Attribute_05
(Attr_Id
) and then Ada_Version
< Ada_2005
)
2647 (Attribute_12
(Attr_Id
) and then Ada_Version
< Ada_2012
)
2649 Check_Restriction
(No_Implementation_Attributes
, N
);
2652 -- Remote access to subprogram type access attribute reference needs
2653 -- unanalyzed copy for tree transformation. The analyzed copy is used
2654 -- for its semantic information (whether prefix is a remote subprogram
2655 -- name), the unanalyzed copy is used to construct new subtree rooted
2656 -- with N_Aggregate which represents a fat pointer aggregate.
2658 if Aname
= Name_Access
then
2659 Discard_Node
(Copy_Separate_Tree
(N
));
2662 -- Analyze prefix and exit if error in analysis. If the prefix is an
2663 -- incomplete type, use full view if available. Note that there are
2664 -- some attributes for which we do not analyze the prefix, since the
2665 -- prefix is not a normal name, or else needs special handling.
2667 if Aname
/= Name_Elab_Body
and then
2668 Aname
/= Name_Elab_Spec
and then
2669 Aname
/= Name_Elab_Subp_Body
and then
2670 Aname
/= Name_UET_Address
and then
2671 Aname
/= Name_Enabled
and then
2675 P_Type
:= Etype
(P
);
2677 if Is_Entity_Name
(P
)
2678 and then Present
(Entity
(P
))
2679 and then Is_Type
(Entity
(P
))
2681 if Ekind
(Entity
(P
)) = E_Incomplete_Type
then
2682 P_Type
:= Get_Full_View
(P_Type
);
2683 Set_Entity
(P
, P_Type
);
2684 Set_Etype
(P
, P_Type
);
2686 elsif Entity
(P
) = Current_Scope
2687 and then Is_Record_Type
(Entity
(P
))
2689 -- Use of current instance within the type. Verify that if the
2690 -- attribute appears within a constraint, it yields an access
2691 -- type, other uses are illegal.
2699 and then Nkind
(Parent
(Par
)) /= N_Component_Definition
2701 Par
:= Parent
(Par
);
2705 and then Nkind
(Par
) = N_Subtype_Indication
2707 if Attr_Id
/= Attribute_Access
2708 and then Attr_Id
/= Attribute_Unchecked_Access
2709 and then Attr_Id
/= Attribute_Unrestricted_Access
2712 ("in a constraint the current instance can only "
2713 & "be used with an access attribute", N
);
2720 if P_Type
= Any_Type
then
2721 raise Bad_Attribute
;
2724 P_Base_Type
:= Base_Type
(P_Type
);
2727 -- Analyze expressions that may be present, exiting if an error occurs
2734 E1
:= First
(Exprs
);
2736 -- Skip analysis for case of Restriction_Set, we do not expect
2737 -- the argument to be analyzed in this case.
2739 if Aname
/= Name_Restriction_Set
then
2742 -- Check for missing/bad expression (result of previous error)
2744 if No
(E1
) or else Etype
(E1
) = Any_Type
then
2745 raise Bad_Attribute
;
2751 if Present
(E2
) then
2754 if Etype
(E2
) = Any_Type
then
2755 raise Bad_Attribute
;
2758 if Present
(Next
(E2
)) then
2759 Unexpected_Argument
(Next
(E2
));
2764 -- Cases where prefix must be resolvable by itself
2766 if Is_Overloaded
(P
)
2767 and then Aname
/= Name_Access
2768 and then Aname
/= Name_Address
2769 and then Aname
/= Name_Code_Address
2770 and then Aname
/= Name_Result
2771 and then Aname
/= Name_Unchecked_Access
2773 -- The prefix must be resolvable by itself, without reference to the
2774 -- attribute. One case that requires special handling is a prefix
2775 -- that is a function name, where one interpretation may be a
2776 -- parameterless call. Entry attributes are handled specially below.
2778 if Is_Entity_Name
(P
)
2779 and then not Nam_In
(Aname
, Name_Count
, Name_Caller
)
2781 Check_Parameterless_Call
(P
);
2784 if Is_Overloaded
(P
) then
2786 -- Ada 2005 (AI-345): Since protected and task types have
2787 -- primitive entry wrappers, the attributes Count, and Caller
2788 -- require a context check
2790 if Nam_In
(Aname
, Name_Count
, Name_Caller
) then
2792 Count
: Natural := 0;
2797 Get_First_Interp
(P
, I
, It
);
2798 while Present
(It
.Nam
) loop
2799 if Comes_From_Source
(It
.Nam
) then
2805 Get_Next_Interp
(I
, It
);
2809 Error_Attr
("ambiguous prefix for % attribute", P
);
2811 Set_Is_Overloaded
(P
, False);
2816 Error_Attr
("ambiguous prefix for % attribute", P
);
2821 -- In SPARK, attributes of private types are only allowed if the full
2822 -- type declaration is visible.
2824 -- Note: the check for Present (Entity (P)) defends against some error
2825 -- conditions where the Entity field is not set.
2827 if Is_Entity_Name
(P
) and then Present
(Entity
(P
))
2828 and then Is_Type
(Entity
(P
))
2829 and then Is_Private_Type
(P_Type
)
2830 and then not In_Open_Scopes
(Scope
(P_Type
))
2831 and then not In_Spec_Expression
2833 Check_SPARK_05_Restriction
("invisible attribute of type", N
);
2836 -- Remaining processing depends on attribute
2840 -- Attributes related to Ada 2012 iterators. Attribute specifications
2841 -- exist for these, but they cannot be queried.
2843 when Attribute_Constant_Indexing |
2844 Attribute_Default_Iterator |
2845 Attribute_Implicit_Dereference |
2846 Attribute_Iterator_Element |
2847 Attribute_Iterable |
2848 Attribute_Variable_Indexing
=>
2849 Error_Msg_N
("illegal attribute", N
);
2851 -- Internal attributes used to deal with Ada 2012 delayed aspects. These
2852 -- were already rejected by the parser. Thus they shouldn't appear here.
2854 when Internal_Attribute_Id
=>
2855 raise Program_Error
;
2861 when Attribute_Abort_Signal
=>
2862 Check_Standard_Prefix
;
2863 Rewrite
(N
, New_Occurrence_Of
(Stand
.Abort_Signal
, Loc
));
2870 when Attribute_Access
=>
2871 Analyze_Access_Attribute
;
2872 Check_Not_Incomplete_Type
;
2878 when Attribute_Address
=>
2881 Check_Not_Incomplete_Type
;
2882 Set_Etype
(N
, RTE
(RE_Address
));
2888 when Attribute_Address_Size
=>
2889 Standard_Attribute
(System_Address_Size
);
2895 when Attribute_Adjacent
=>
2896 Check_Floating_Point_Type_2
;
2897 Set_Etype
(N
, P_Base_Type
);
2898 Resolve
(E1
, P_Base_Type
);
2899 Resolve
(E2
, P_Base_Type
);
2905 when Attribute_Aft
=>
2906 Check_Fixed_Point_Type_0
;
2907 Set_Etype
(N
, Universal_Integer
);
2913 when Attribute_Alignment
=>
2915 -- Don't we need more checking here, cf Size ???
2918 Check_Not_Incomplete_Type
;
2920 Set_Etype
(N
, Universal_Integer
);
2926 when Attribute_Asm_Input
=>
2927 Check_Asm_Attribute
;
2929 -- The back-end may need to take the address of E2
2931 if Is_Entity_Name
(E2
) then
2932 Set_Address_Taken
(Entity
(E2
));
2935 Set_Etype
(N
, RTE
(RE_Asm_Input_Operand
));
2941 when Attribute_Asm_Output
=>
2942 Check_Asm_Attribute
;
2944 if Etype
(E2
) = Any_Type
then
2947 elsif Aname
= Name_Asm_Output
then
2948 if not Is_Variable
(E2
) then
2950 ("second argument for Asm_Output is not variable", E2
);
2954 Note_Possible_Modification
(E2
, Sure
=> True);
2956 -- The back-end may need to take the address of E2
2958 if Is_Entity_Name
(E2
) then
2959 Set_Address_Taken
(Entity
(E2
));
2962 Set_Etype
(N
, RTE
(RE_Asm_Output_Operand
));
2964 -----------------------------
2965 -- Atomic_Always_Lock_Free --
2966 -----------------------------
2968 when Attribute_Atomic_Always_Lock_Free
=>
2971 Set_Etype
(N
, Standard_Boolean
);
2977 -- Note: when the base attribute appears in the context of a subtype
2978 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2979 -- the following circuit.
2981 when Attribute_Base
=> Base
: declare
2989 if Ada_Version
>= Ada_95
2990 and then not Is_Scalar_Type
(Typ
)
2991 and then not Is_Generic_Type
(Typ
)
2993 Error_Attr_P
("prefix of Base attribute must be scalar type");
2995 elsif Sloc
(Typ
) = Standard_Location
2996 and then Base_Type
(Typ
) = Typ
2997 and then Warn_On_Redundant_Constructs
2999 Error_Msg_NE
-- CODEFIX
3000 ("?r?redundant attribute, & is its own base type", N
, Typ
);
3003 if Nkind
(Parent
(N
)) /= N_Attribute_Reference
then
3004 Error_Msg_Name_1
:= Aname
;
3005 Check_SPARK_05_Restriction
3006 ("attribute% is only allowed as prefix of another attribute", P
);
3009 Set_Etype
(N
, Base_Type
(Entity
(P
)));
3010 Set_Entity
(N
, Base_Type
(Entity
(P
)));
3011 Rewrite
(N
, New_Occurrence_Of
(Entity
(N
), Loc
));
3019 when Attribute_Bit
=> Bit
:
3023 if not Is_Object_Reference
(P
) then
3024 Error_Attr_P
("prefix for % attribute must be object");
3026 -- What about the access object cases ???
3032 Set_Etype
(N
, Universal_Integer
);
3039 when Attribute_Bit_Order
=> Bit_Order
:
3044 if not Is_Record_Type
(P_Type
) then
3045 Error_Attr_P
("prefix of % attribute must be record type");
3048 if Bytes_Big_Endian
xor Reverse_Bit_Order
(P_Type
) then
3050 New_Occurrence_Of
(RTE
(RE_High_Order_First
), Loc
));
3053 New_Occurrence_Of
(RTE
(RE_Low_Order_First
), Loc
));
3056 Set_Etype
(N
, RTE
(RE_Bit_Order
));
3059 -- Reset incorrect indication of staticness
3061 Set_Is_Static_Expression
(N
, False);
3068 -- Note: in generated code, we can have a Bit_Position attribute
3069 -- applied to a (naked) record component (i.e. the prefix is an
3070 -- identifier that references an E_Component or E_Discriminant
3071 -- entity directly, and this is interpreted as expected by Gigi.
3072 -- The following code will not tolerate such usage, but when the
3073 -- expander creates this special case, it marks it as analyzed
3074 -- immediately and sets an appropriate type.
3076 when Attribute_Bit_Position
=>
3077 if Comes_From_Source
(N
) then
3081 Set_Etype
(N
, Universal_Integer
);
3087 when Attribute_Body_Version
=>
3090 Set_Etype
(N
, RTE
(RE_Version_String
));
3096 when Attribute_Callable
=>
3098 Set_Etype
(N
, Standard_Boolean
);
3105 when Attribute_Caller
=> Caller
: declare
3112 if Nkind_In
(P
, N_Identifier
, N_Expanded_Name
) then
3115 if not Is_Entry
(Ent
) then
3116 Error_Attr
("invalid entry name", N
);
3120 Error_Attr
("invalid entry name", N
);
3124 for J
in reverse 0 .. Scope_Stack
.Last
loop
3125 S
:= Scope_Stack
.Table
(J
).Entity
;
3127 if S
= Scope
(Ent
) then
3128 Error_Attr
("Caller must appear in matching accept or body", N
);
3134 Set_Etype
(N
, RTE
(RO_AT_Task_Id
));
3141 when Attribute_Ceiling
=>
3142 Check_Floating_Point_Type_1
;
3143 Set_Etype
(N
, P_Base_Type
);
3144 Resolve
(E1
, P_Base_Type
);
3150 when Attribute_Class
=>
3151 Check_Restriction
(No_Dispatch
, N
);
3155 -- Applying Class to untagged incomplete type is obsolescent in Ada
3156 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
3157 -- this flag gets set by Find_Type in this situation.
3159 if Restriction_Check_Required
(No_Obsolescent_Features
)
3160 and then Ada_Version
>= Ada_2005
3161 and then Ekind
(P_Type
) = E_Incomplete_Type
3164 DN
: constant Node_Id
:= Declaration_Node
(P_Type
);
3166 if Nkind
(DN
) = N_Incomplete_Type_Declaration
3167 and then not Tagged_Present
(DN
)
3169 Check_Restriction
(No_Obsolescent_Features
, P
);
3178 when Attribute_Code_Address
=>
3181 if Nkind
(P
) = N_Attribute_Reference
3182 and then Nam_In
(Attribute_Name
(P
), Name_Elab_Body
, Name_Elab_Spec
)
3186 elsif not Is_Entity_Name
(P
)
3187 or else (Ekind
(Entity
(P
)) /= E_Function
3189 Ekind
(Entity
(P
)) /= E_Procedure
)
3191 Error_Attr
("invalid prefix for % attribute", P
);
3192 Set_Address_Taken
(Entity
(P
));
3194 -- Issue an error if the prefix denotes an eliminated subprogram
3197 Check_For_Eliminated_Subprogram
(P
, Entity
(P
));
3200 Set_Etype
(N
, RTE
(RE_Address
));
3202 ----------------------
3203 -- Compiler_Version --
3204 ----------------------
3206 when Attribute_Compiler_Version
=>
3208 Check_Standard_Prefix
;
3209 Rewrite
(N
, Make_String_Literal
(Loc
, "GNAT " & Gnat_Version_String
));
3210 Analyze_And_Resolve
(N
, Standard_String
);
3211 Set_Is_Static_Expression
(N
, True);
3213 --------------------
3214 -- Component_Size --
3215 --------------------
3217 when Attribute_Component_Size
=>
3219 Set_Etype
(N
, Universal_Integer
);
3221 -- Note: unlike other array attributes, unconstrained arrays are OK
3223 if Is_Array_Type
(P_Type
) and then not Is_Constrained
(P_Type
) then
3233 when Attribute_Compose
=>
3234 Check_Floating_Point_Type_2
;
3235 Set_Etype
(N
, P_Base_Type
);
3236 Resolve
(E1
, P_Base_Type
);
3237 Resolve
(E2
, Any_Integer
);
3243 when Attribute_Constrained
=>
3245 Set_Etype
(N
, Standard_Boolean
);
3247 -- Case from RM J.4(2) of constrained applied to private type
3249 if Is_Entity_Name
(P
) and then Is_Type
(Entity
(P
)) then
3250 Check_Restriction
(No_Obsolescent_Features
, P
);
3252 if Warn_On_Obsolescent_Feature
then
3254 ("constrained for private type is an " &
3255 "obsolescent feature (RM J.4)?j?", N
);
3258 -- If we are within an instance, the attribute must be legal
3259 -- because it was valid in the generic unit. Ditto if this is
3260 -- an inlining of a function declared in an instance.
3262 if In_Instance
or else In_Inlined_Body
then
3265 -- For sure OK if we have a real private type itself, but must
3266 -- be completed, cannot apply Constrained to incomplete type.
3268 elsif Is_Private_Type
(Entity
(P
)) then
3270 -- Note: this is one of the Annex J features that does not
3271 -- generate a warning from -gnatwj, since in fact it seems
3272 -- very useful, and is used in the GNAT runtime.
3274 Check_Not_Incomplete_Type
;
3278 -- Normal (non-obsolescent case) of application to object of
3279 -- a discriminated type.
3282 Check_Object_Reference
(P
);
3284 -- If N does not come from source, then we allow the
3285 -- the attribute prefix to be of a private type whose
3286 -- full type has discriminants. This occurs in cases
3287 -- involving expanded calls to stream attributes.
3289 if not Comes_From_Source
(N
) then
3290 P_Type
:= Underlying_Type
(P_Type
);
3293 -- Must have discriminants or be an access type designating
3294 -- a type with discriminants. If it is a classwide type it
3295 -- has unknown discriminants.
3297 if Has_Discriminants
(P_Type
)
3298 or else Has_Unknown_Discriminants
(P_Type
)
3300 (Is_Access_Type
(P_Type
)
3301 and then Has_Discriminants
(Designated_Type
(P_Type
)))
3305 -- The rule given in 3.7.2 is part of static semantics, but the
3306 -- intent is clearly that it be treated as a legality rule, and
3307 -- rechecked in the visible part of an instance. Nevertheless
3308 -- the intent also seems to be it should legally apply to the
3309 -- actual of a formal with unknown discriminants, regardless of
3310 -- whether the actual has discriminants, in which case the value
3311 -- of the attribute is determined using the J.4 rules. This choice
3312 -- seems the most useful, and is compatible with existing tests.
3314 elsif In_Instance
then
3317 -- Also allow an object of a generic type if extensions allowed
3318 -- and allow this for any type at all. (this may be obsolete ???)
3320 elsif (Is_Generic_Type
(P_Type
)
3321 or else Is_Generic_Actual_Type
(P_Type
))
3322 and then Extensions_Allowed
3328 -- Fall through if bad prefix
3331 ("prefix of % attribute must be object of discriminated type");
3337 when Attribute_Copy_Sign
=>
3338 Check_Floating_Point_Type_2
;
3339 Set_Etype
(N
, P_Base_Type
);
3340 Resolve
(E1
, P_Base_Type
);
3341 Resolve
(E2
, P_Base_Type
);
3347 when Attribute_Count
=> Count
:
3356 if Nkind_In
(P
, N_Identifier
, N_Expanded_Name
) then
3359 if Ekind
(Ent
) /= E_Entry
then
3360 Error_Attr
("invalid entry name", N
);
3363 elsif Nkind
(P
) = N_Indexed_Component
then
3364 if not Is_Entity_Name
(Prefix
(P
))
3365 or else No
(Entity
(Prefix
(P
)))
3366 or else Ekind
(Entity
(Prefix
(P
))) /= E_Entry_Family
3368 if Nkind
(Prefix
(P
)) = N_Selected_Component
3369 and then Present
(Entity
(Selector_Name
(Prefix
(P
))))
3370 and then Ekind
(Entity
(Selector_Name
(Prefix
(P
)))) =
3374 ("attribute % must apply to entry of current task", P
);
3377 Error_Attr
("invalid entry family name", P
);
3382 Ent
:= Entity
(Prefix
(P
));
3385 elsif Nkind
(P
) = N_Selected_Component
3386 and then Present
(Entity
(Selector_Name
(P
)))
3387 and then Ekind
(Entity
(Selector_Name
(P
))) = E_Entry
3390 ("attribute % must apply to entry of current task", P
);
3393 Error_Attr
("invalid entry name", N
);
3397 for J
in reverse 0 .. Scope_Stack
.Last
loop
3398 S
:= Scope_Stack
.Table
(J
).Entity
;
3400 if S
= Scope
(Ent
) then
3401 if Nkind
(P
) = N_Expanded_Name
then
3402 Tsk
:= Entity
(Prefix
(P
));
3404 -- The prefix denotes either the task type, or else a
3405 -- single task whose task type is being analyzed.
3407 if (Is_Type
(Tsk
) and then Tsk
= S
)
3408 or else (not Is_Type
(Tsk
)
3409 and then Etype
(Tsk
) = S
3410 and then not (Comes_From_Source
(S
)))
3415 ("Attribute % must apply to entry of current task", N
);
3421 elsif Ekind
(Scope
(Ent
)) in Task_Kind
3423 not Ekind_In
(S
, E_Loop
, E_Block
, E_Entry
, E_Entry_Family
)
3425 Error_Attr
("Attribute % cannot appear in inner unit", N
);
3427 elsif Ekind
(Scope
(Ent
)) = E_Protected_Type
3428 and then not Has_Completion
(Scope
(Ent
))
3430 Error_Attr
("attribute % can only be used inside body", N
);
3434 if Is_Overloaded
(P
) then
3436 Index
: Interp_Index
;
3440 Get_First_Interp
(P
, Index
, It
);
3441 while Present
(It
.Nam
) loop
3442 if It
.Nam
= Ent
then
3445 -- Ada 2005 (AI-345): Do not consider primitive entry
3446 -- wrappers generated for task or protected types.
3448 elsif Ada_Version
>= Ada_2005
3449 and then not Comes_From_Source
(It
.Nam
)
3454 Error_Attr
("ambiguous entry name", N
);
3457 Get_Next_Interp
(Index
, It
);
3462 Set_Etype
(N
, Universal_Integer
);
3465 -----------------------
3466 -- Default_Bit_Order --
3467 -----------------------
3469 when Attribute_Default_Bit_Order
=> Default_Bit_Order
: declare
3470 Target_Default_Bit_Order
: System
.Bit_Order
;
3473 Check_Standard_Prefix
;
3475 if Bytes_Big_Endian
then
3476 Target_Default_Bit_Order
:= System
.High_Order_First
;
3478 Target_Default_Bit_Order
:= System
.Low_Order_First
;
3482 Make_Integer_Literal
(Loc
,
3483 UI_From_Int
(System
.Bit_Order
'Pos (Target_Default_Bit_Order
))));
3485 Set_Etype
(N
, Universal_Integer
);
3486 Set_Is_Static_Expression
(N
);
3487 end Default_Bit_Order
;
3489 ----------------------------------
3490 -- Default_Scalar_Storage_Order --
3491 ----------------------------------
3493 when Attribute_Default_Scalar_Storage_Order
=> Default_SSO
: declare
3494 RE_Default_SSO
: RE_Id
;
3497 Check_Standard_Prefix
;
3499 case Opt
.Default_SSO
is
3501 if Bytes_Big_Endian
then
3502 RE_Default_SSO
:= RE_High_Order_First
;
3504 RE_Default_SSO
:= RE_Low_Order_First
;
3508 RE_Default_SSO
:= RE_High_Order_First
;
3511 RE_Default_SSO
:= RE_Low_Order_First
;
3514 raise Program_Error
;
3517 Rewrite
(N
, New_Occurrence_Of
(RTE
(RE_Default_SSO
), Loc
));
3524 when Attribute_Definite
=>
3525 Legal_Formal_Attribute
;
3531 when Attribute_Delta
=>
3532 Check_Fixed_Point_Type_0
;
3533 Set_Etype
(N
, Universal_Real
);
3539 when Attribute_Denorm
=>
3540 Check_Floating_Point_Type_0
;
3541 Set_Etype
(N
, Standard_Boolean
);
3547 when Attribute_Deref
=>
3550 Resolve
(E1
, RTE
(RE_Address
));
3551 Set_Etype
(N
, P_Type
);
3553 ---------------------
3554 -- Descriptor_Size --
3555 ---------------------
3557 when Attribute_Descriptor_Size
=>
3560 if not Is_Entity_Name
(P
) or else not Is_Type
(Entity
(P
)) then
3561 Error_Attr_P
("prefix of attribute % must denote a type");
3564 Set_Etype
(N
, Universal_Integer
);
3570 when Attribute_Digits
=>
3574 if not Is_Floating_Point_Type
(P_Type
)
3575 and then not Is_Decimal_Fixed_Point_Type
(P_Type
)
3578 ("prefix of % attribute must be float or decimal type");
3581 Set_Etype
(N
, Universal_Integer
);
3587 -- Also handles processing for Elab_Spec and Elab_Subp_Body
3589 when Attribute_Elab_Body |
3590 Attribute_Elab_Spec |
3591 Attribute_Elab_Subp_Body
=>
3594 Check_Unit_Name
(P
);
3595 Set_Etype
(N
, Standard_Void_Type
);
3597 -- We have to manually call the expander in this case to get
3598 -- the necessary expansion (normally attributes that return
3599 -- entities are not expanded).
3607 -- Shares processing with Elab_Body
3613 when Attribute_Elaborated
=>
3615 Check_Unit_Name
(P
);
3616 Set_Etype
(N
, Standard_Boolean
);
3622 when Attribute_Emax
=>
3623 Check_Floating_Point_Type_0
;
3624 Set_Etype
(N
, Universal_Integer
);
3630 when Attribute_Enabled
=>
3631 Check_Either_E0_Or_E1
;
3633 if Present
(E1
) then
3634 if not Is_Entity_Name
(E1
) or else No
(Entity
(E1
)) then
3635 Error_Msg_N
("entity name expected for Enabled attribute", E1
);
3640 if Nkind
(P
) /= N_Identifier
then
3641 Error_Msg_N
("identifier expected (check name)", P
);
3642 elsif Get_Check_Id
(Chars
(P
)) = No_Check_Id
then
3643 Error_Msg_N
("& is not a recognized check name", P
);
3646 Set_Etype
(N
, Standard_Boolean
);
3652 when Attribute_Enum_Rep
=> Enum_Rep
: declare
3654 if Present
(E1
) then
3656 Check_Discrete_Type
;
3657 Resolve
(E1
, P_Base_Type
);
3660 if not Is_Entity_Name
(P
)
3661 or else (not Is_Object
(Entity
(P
))
3662 and then Ekind
(Entity
(P
)) /= E_Enumeration_Literal
)
3665 ("prefix of % attribute must be " &
3666 "discrete type/object or enum literal");
3670 Set_Etype
(N
, Universal_Integer
);
3677 when Attribute_Enum_Val
=> Enum_Val
: begin
3681 if not Is_Enumeration_Type
(P_Type
) then
3682 Error_Attr_P
("prefix of % attribute must be enumeration type");
3685 -- If the enumeration type has a standard representation, the effect
3686 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3688 if not Has_Non_Standard_Rep
(P_Base_Type
) then
3690 Make_Attribute_Reference
(Loc
,
3691 Prefix
=> Relocate_Node
(Prefix
(N
)),
3692 Attribute_Name
=> Name_Val
,
3693 Expressions
=> New_List
(Relocate_Node
(E1
))));
3694 Analyze_And_Resolve
(N
, P_Base_Type
);
3696 -- Non-standard representation case (enumeration with holes)
3700 Resolve
(E1
, Any_Integer
);
3701 Set_Etype
(N
, P_Base_Type
);
3709 when Attribute_Epsilon
=>
3710 Check_Floating_Point_Type_0
;
3711 Set_Etype
(N
, Universal_Real
);
3717 when Attribute_Exponent
=>
3718 Check_Floating_Point_Type_1
;
3719 Set_Etype
(N
, Universal_Integer
);
3720 Resolve
(E1
, P_Base_Type
);
3726 when Attribute_External_Tag
=>
3730 Set_Etype
(N
, Standard_String
);
3732 if not Is_Tagged_Type
(P_Type
) then
3733 Error_Attr_P
("prefix of % attribute must be tagged");
3740 when Attribute_Fast_Math
=>
3741 Check_Standard_Prefix
;
3742 Rewrite
(N
, New_Occurrence_Of
(Boolean_Literals
(Fast_Math
), Loc
));
3748 when Attribute_First
=>
3749 Check_Array_Or_Scalar_Type
;
3750 Bad_Attribute_For_Predicate
;
3756 when Attribute_First_Bit
=>
3758 Set_Etype
(N
, Universal_Integer
);
3764 when Attribute_First_Valid
=>
3765 Check_First_Last_Valid
;
3766 Set_Etype
(N
, P_Type
);
3772 when Attribute_Fixed_Value
=>
3774 Check_Fixed_Point_Type
;
3775 Resolve
(E1
, Any_Integer
);
3776 Set_Etype
(N
, P_Base_Type
);
3782 when Attribute_Floor
=>
3783 Check_Floating_Point_Type_1
;
3784 Set_Etype
(N
, P_Base_Type
);
3785 Resolve
(E1
, P_Base_Type
);
3791 when Attribute_Fore
=>
3792 Check_Fixed_Point_Type_0
;
3793 Set_Etype
(N
, Universal_Integer
);
3799 when Attribute_Fraction
=>
3800 Check_Floating_Point_Type_1
;
3801 Set_Etype
(N
, P_Base_Type
);
3802 Resolve
(E1
, P_Base_Type
);
3808 when Attribute_From_Any
=>
3810 Check_PolyORB_Attribute
;
3811 Set_Etype
(N
, P_Base_Type
);
3813 -----------------------
3814 -- Has_Access_Values --
3815 -----------------------
3817 when Attribute_Has_Access_Values
=>
3820 Set_Etype
(N
, Standard_Boolean
);
3822 ----------------------
3823 -- Has_Same_Storage --
3824 ----------------------
3826 when Attribute_Has_Same_Storage
=>
3829 -- The arguments must be objects of any type
3831 Analyze_And_Resolve
(P
);
3832 Analyze_And_Resolve
(E1
);
3833 Check_Object_Reference
(P
);
3834 Check_Object_Reference
(E1
);
3835 Set_Etype
(N
, Standard_Boolean
);
3837 -----------------------
3838 -- Has_Tagged_Values --
3839 -----------------------
3841 when Attribute_Has_Tagged_Values
=>
3844 Set_Etype
(N
, Standard_Boolean
);
3846 -----------------------
3847 -- Has_Discriminants --
3848 -----------------------
3850 when Attribute_Has_Discriminants
=>
3851 Legal_Formal_Attribute
;
3857 when Attribute_Identity
=>
3861 if Etype
(P
) = Standard_Exception_Type
then
3862 Set_Etype
(N
, RTE
(RE_Exception_Id
));
3864 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to task
3865 -- interface class-wide types.
3867 elsif Is_Task_Type
(Etype
(P
))
3868 or else (Is_Access_Type
(Etype
(P
))
3869 and then Is_Task_Type
(Designated_Type
(Etype
(P
))))
3870 or else (Ada_Version
>= Ada_2005
3871 and then Ekind
(Etype
(P
)) = E_Class_Wide_Type
3872 and then Is_Interface
(Etype
(P
))
3873 and then Is_Task_Interface
(Etype
(P
)))
3876 Set_Etype
(N
, RTE
(RO_AT_Task_Id
));
3879 if Ada_Version
>= Ada_2005
then
3881 ("prefix of % attribute must be an exception, a " &
3882 "task or a task interface class-wide object");
3885 ("prefix of % attribute must be a task or an exception");
3893 when Attribute_Image
=> Image
:
3895 Check_SPARK_05_Restriction_On_Attribute
;
3897 Set_Etype
(N
, Standard_String
);
3899 if Is_Real_Type
(P_Type
) then
3900 if Ada_Version
= Ada_83
and then Comes_From_Source
(N
) then
3901 Error_Msg_Name_1
:= Aname
;
3903 ("(Ada 83) % attribute not allowed for real types", N
);
3907 if Is_Enumeration_Type
(P_Type
) then
3908 Check_Restriction
(No_Enumeration_Maps
, N
);
3912 Resolve
(E1
, P_Base_Type
);
3914 Validate_Non_Static_Attribute_Function_Call
;
3916 -- Check restriction No_Fixed_IO. Note the check of Comes_From_Source
3917 -- to avoid giving a duplicate message for Img expanded into Image.
3919 if Restriction_Check_Required
(No_Fixed_IO
)
3920 and then Comes_From_Source
(N
)
3921 and then Is_Fixed_Point_Type
(P_Type
)
3923 Check_Restriction
(No_Fixed_IO
, P
);
3931 when Attribute_Img
=> Img
:
3934 Set_Etype
(N
, Standard_String
);
3936 if not Is_Scalar_Type
(P_Type
)
3937 or else (Is_Entity_Name
(P
) and then Is_Type
(Entity
(P
)))
3940 ("prefix of % attribute must be scalar object name");
3945 -- Check restriction No_Fixed_IO
3947 if Restriction_Check_Required
(No_Fixed_IO
)
3948 and then Is_Fixed_Point_Type
(P_Type
)
3950 Check_Restriction
(No_Fixed_IO
, P
);
3958 when Attribute_Input
=>
3960 Check_Stream_Attribute
(TSS_Stream_Input
);
3961 Set_Etype
(N
, P_Base_Type
);
3967 when Attribute_Integer_Value
=>
3970 Resolve
(E1
, Any_Fixed
);
3972 -- Signal an error if argument type is not a specific fixed-point
3973 -- subtype. An error has been signalled already if the argument
3974 -- was not of a fixed-point type.
3976 if Etype
(E1
) = Any_Fixed
and then not Error_Posted
(E1
) then
3977 Error_Attr
("argument of % must be of a fixed-point type", E1
);
3980 Set_Etype
(N
, P_Base_Type
);
3986 when Attribute_Invalid_Value
=>
3989 Set_Etype
(N
, P_Base_Type
);
3990 Invalid_Value_Used
:= True;
3996 when Attribute_Large
=>
3999 Set_Etype
(N
, Universal_Real
);
4005 when Attribute_Last
=>
4006 Check_Array_Or_Scalar_Type
;
4007 Bad_Attribute_For_Predicate
;
4013 when Attribute_Last_Bit
=>
4015 Set_Etype
(N
, Universal_Integer
);
4021 when Attribute_Last_Valid
=>
4022 Check_First_Last_Valid
;
4023 Set_Etype
(N
, P_Type
);
4029 when Attribute_Leading_Part
=>
4030 Check_Floating_Point_Type_2
;
4031 Set_Etype
(N
, P_Base_Type
);
4032 Resolve
(E1
, P_Base_Type
);
4033 Resolve
(E2
, Any_Integer
);
4039 when Attribute_Length
=>
4041 Set_Etype
(N
, Universal_Integer
);
4047 when Attribute_Library_Level
=>
4050 if not Is_Entity_Name
(P
) then
4051 Error_Attr_P
("prefix of % attribute must be an entity name");
4054 if not Inside_A_Generic
then
4055 Set_Boolean_Result
(N
,
4056 Is_Library_Level_Entity
(Entity
(P
)));
4059 Set_Etype
(N
, Standard_Boolean
);
4065 when Attribute_Lock_Free
=>
4067 Set_Etype
(N
, Standard_Boolean
);
4069 if not Is_Protected_Type
(P_Type
) then
4071 ("prefix of % attribute must be a protected object");
4078 when Attribute_Loop_Entry
=> Loop_Entry
: declare
4079 procedure Check_References_In_Prefix
(Loop_Id
: Entity_Id
);
4080 -- Inspect the prefix for any uses of entities declared within the
4081 -- related loop. Loop_Id denotes the loop identifier.
4083 --------------------------------
4084 -- Check_References_In_Prefix --
4085 --------------------------------
4087 procedure Check_References_In_Prefix
(Loop_Id
: Entity_Id
) is
4088 Loop_Decl
: constant Node_Id
:= Label_Construct
(Parent
(Loop_Id
));
4090 function Check_Reference
(Nod
: Node_Id
) return Traverse_Result
;
4091 -- Determine whether a reference mentions an entity declared
4092 -- within the related loop.
4094 function Declared_Within
(Nod
: Node_Id
) return Boolean;
4095 -- Determine whether Nod appears in the subtree of Loop_Decl
4097 ---------------------
4098 -- Check_Reference --
4099 ---------------------
4101 function Check_Reference
(Nod
: Node_Id
) return Traverse_Result
is
4103 if Nkind
(Nod
) = N_Identifier
4104 and then Present
(Entity
(Nod
))
4105 and then Declared_Within
(Declaration_Node
(Entity
(Nod
)))
4108 ("prefix of attribute % cannot reference local entities",
4114 end Check_Reference
;
4116 procedure Check_References
is new Traverse_Proc
(Check_Reference
);
4118 ---------------------
4119 -- Declared_Within --
4120 ---------------------
4122 function Declared_Within
(Nod
: Node_Id
) return Boolean is
4127 while Present
(Stmt
) loop
4128 if Stmt
= Loop_Decl
then
4131 -- Prevent the search from going too far
4133 elsif Is_Body_Or_Package_Declaration
(Stmt
) then
4137 Stmt
:= Parent
(Stmt
);
4141 end Declared_Within
;
4143 -- Start of processing for Check_Prefix_For_Local_References
4146 Check_References
(P
);
4147 end Check_References_In_Prefix
;
4151 Context
: constant Node_Id
:= Parent
(N
);
4153 Enclosing_Loop
: Node_Id
;
4154 Loop_Id
: Entity_Id
:= Empty
;
4157 Enclosing_Pragma
: Node_Id
:= Empty
;
4159 -- Start of processing for Loop_Entry
4164 -- Set the type of the attribute now to ensure the successfull
4165 -- continuation of analysis even if the attribute is misplaced.
4167 Set_Etype
(Attr
, P_Type
);
4169 -- Attribute 'Loop_Entry may appear in several flavors:
4171 -- * Prefix'Loop_Entry - in this form, the attribute applies to the
4172 -- nearest enclosing loop.
4174 -- * Prefix'Loop_Entry (Expr) - depending on what Expr denotes, the
4175 -- attribute may be related to a loop denoted by label Expr or
4176 -- the prefix may denote an array object and Expr may act as an
4177 -- indexed component.
4179 -- * Prefix'Loop_Entry (Expr1, ..., ExprN) - the attribute applies
4180 -- to the nearest enclosing loop, all expressions are part of
4181 -- an indexed component.
4183 -- * Prefix'Loop_Entry (Expr) (...) (...) - depending on what Expr
4184 -- denotes, the attribute may be related to a loop denoted by
4185 -- label Expr or the prefix may denote a multidimensional array
4186 -- array object and Expr along with the rest of the expressions
4187 -- may act as indexed components.
4189 -- Regardless of variations, the attribute reference does not have an
4190 -- expression list. Instead, all available expressions are stored as
4191 -- indexed components.
4193 -- When the attribute is part of an indexed component, find the first
4194 -- expression as it will determine the semantics of 'Loop_Entry.
4196 if Nkind
(Context
) = N_Indexed_Component
then
4197 E1
:= First
(Expressions
(Context
));
4200 -- The attribute reference appears in the following form:
4202 -- Prefix'Loop_Entry (Exp1, Expr2, ..., ExprN) [(...)]
4204 -- In this case, the loop name is omitted and no rewriting is
4207 if Present
(E2
) then
4210 -- The form of the attribute is:
4212 -- Prefix'Loop_Entry (Expr) [(...)]
4214 -- If Expr denotes a loop entry, the whole attribute and indexed
4215 -- component will have to be rewritten to reflect this relation.
4218 pragma Assert
(Present
(E1
));
4220 -- Do not expand the expression as it may have side effects.
4221 -- Simply preanalyze to determine whether it is a loop name or
4224 Preanalyze_And_Resolve
(E1
);
4226 if Is_Entity_Name
(E1
)
4227 and then Present
(Entity
(E1
))
4228 and then Ekind
(Entity
(E1
)) = E_Loop
4230 Loop_Id
:= Entity
(E1
);
4232 -- Transform the attribute and enclosing indexed component
4234 Set_Expressions
(N
, Expressions
(Context
));
4235 Rewrite
(Context
, N
);
4236 Set_Etype
(Context
, P_Type
);
4243 -- The prefix must denote an object
4245 if not Is_Object_Reference
(P
) then
4246 Error_Attr_P
("prefix of attribute % must denote an object");
4249 -- The prefix cannot be of a limited type because the expansion of
4250 -- Loop_Entry must create a constant initialized by the evaluated
4253 if Is_Limited_View
(Etype
(P
)) then
4254 Error_Attr_P
("prefix of attribute % cannot be limited");
4257 -- Climb the parent chain to verify the location of the attribute and
4258 -- find the enclosing loop.
4261 while Present
(Stmt
) loop
4263 -- Locate the corresponding enclosing pragma. Note that in the
4264 -- case of Assert[And_Cut] and Assume, we have already checked
4265 -- that the pragma appears in an appropriate loop location.
4267 if Nkind
(Original_Node
(Stmt
)) = N_Pragma
4268 and then Nam_In
(Pragma_Name
(Original_Node
(Stmt
)),
4269 Name_Loop_Invariant
,
4272 Name_Assert_And_Cut
,
4275 Enclosing_Pragma
:= Original_Node
(Stmt
);
4277 -- Locate the enclosing loop (if any). Note that Ada 2012 array
4278 -- iteration may be expanded into several nested loops, we are
4279 -- interested in the outermost one which has the loop identifier.
4281 elsif Nkind
(Stmt
) = N_Loop_Statement
4282 and then Present
(Identifier
(Stmt
))
4284 Enclosing_Loop
:= Stmt
;
4286 -- The original attribute reference may lack a loop name. Use
4287 -- the name of the enclosing loop because it is the related
4290 if No
(Loop_Id
) then
4291 Loop_Id
:= Entity
(Identifier
(Enclosing_Loop
));
4296 -- Prevent the search from going too far
4298 elsif Is_Body_Or_Package_Declaration
(Stmt
) then
4302 Stmt
:= Parent
(Stmt
);
4305 -- Loop_Entry must appear within a Loop_Assertion pragma (Assert,
4306 -- Assert_And_Cut, Assume count as loop assertion pragmas for this
4307 -- purpose if they appear in an appropriate location in a loop,
4308 -- which was already checked by the top level pragma circuit).
4310 if No
(Enclosing_Pragma
) then
4311 Error_Attr
("attribute% must appear within appropriate pragma", N
);
4314 -- A Loop_Entry that applies to a given loop statement must not
4315 -- appear within a body of accept statement, if this construct is
4316 -- itself enclosed by the given loop statement.
4318 for Index
in reverse 0 .. Scope_Stack
.Last
loop
4319 Scop
:= Scope_Stack
.Table
(Index
).Entity
;
4321 if Ekind
(Scop
) = E_Loop
and then Scop
= Loop_Id
then
4323 elsif Ekind_In
(Scop
, E_Block
, E_Loop
, E_Return_Statement
) then
4327 ("attribute % cannot appear in body or accept statement", N
);
4332 -- The prefix cannot mention entities declared within the related
4333 -- loop because they will not be visible once the prefix is moved
4334 -- outside the loop.
4336 Check_References_In_Prefix
(Loop_Id
);
4338 -- The prefix must denote a static entity if the pragma does not
4339 -- apply to the innermost enclosing loop statement, or if it appears
4340 -- within a potentially unevaluated epxression.
4342 if Is_Entity_Name
(P
)
4343 or else Nkind
(Parent
(P
)) = N_Object_Renaming_Declaration
4347 elsif Present
(Enclosing_Loop
)
4348 and then Entity
(Identifier
(Enclosing_Loop
)) /= Loop_Id
4351 ("prefix of attribute % that applies to outer loop must denote "
4354 elsif Is_Potentially_Unevaluated
(P
) then
4358 -- Replace the Loop_Entry attribute reference by its prefix if the
4359 -- related pragma is ignored. This transformation is OK with respect
4360 -- to typing because Loop_Entry's type is that of its prefix. This
4361 -- early transformation also avoids the generation of a useless loop
4364 if Is_Ignored
(Enclosing_Pragma
) then
4365 Rewrite
(N
, Relocate_Node
(P
));
4368 Preanalyze_And_Resolve
(P
);
4375 when Attribute_Machine
=>
4376 Check_Floating_Point_Type_1
;
4377 Set_Etype
(N
, P_Base_Type
);
4378 Resolve
(E1
, P_Base_Type
);
4384 when Attribute_Machine_Emax
=>
4385 Check_Floating_Point_Type_0
;
4386 Set_Etype
(N
, Universal_Integer
);
4392 when Attribute_Machine_Emin
=>
4393 Check_Floating_Point_Type_0
;
4394 Set_Etype
(N
, Universal_Integer
);
4396 ----------------------
4397 -- Machine_Mantissa --
4398 ----------------------
4400 when Attribute_Machine_Mantissa
=>
4401 Check_Floating_Point_Type_0
;
4402 Set_Etype
(N
, Universal_Integer
);
4404 -----------------------
4405 -- Machine_Overflows --
4406 -----------------------
4408 when Attribute_Machine_Overflows
=>
4411 Set_Etype
(N
, Standard_Boolean
);
4417 when Attribute_Machine_Radix
=>
4420 Set_Etype
(N
, Universal_Integer
);
4422 ----------------------
4423 -- Machine_Rounding --
4424 ----------------------
4426 when Attribute_Machine_Rounding
=>
4427 Check_Floating_Point_Type_1
;
4428 Set_Etype
(N
, P_Base_Type
);
4429 Resolve
(E1
, P_Base_Type
);
4431 --------------------
4432 -- Machine_Rounds --
4433 --------------------
4435 when Attribute_Machine_Rounds
=>
4438 Set_Etype
(N
, Standard_Boolean
);
4444 when Attribute_Machine_Size
=>
4447 Check_Not_Incomplete_Type
;
4448 Set_Etype
(N
, Universal_Integer
);
4454 when Attribute_Mantissa
=>
4457 Set_Etype
(N
, Universal_Integer
);
4463 when Attribute_Max
=>
4466 ----------------------------------
4467 -- Max_Alignment_For_Allocation --
4468 ----------------------------------
4470 when Attribute_Max_Size_In_Storage_Elements
=>
4471 Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements
;
4473 ----------------------------------
4474 -- Max_Size_In_Storage_Elements --
4475 ----------------------------------
4477 when Attribute_Max_Alignment_For_Allocation
=>
4478 Max_Alignment_For_Allocation_Max_Size_In_Storage_Elements
;
4480 -----------------------
4481 -- Maximum_Alignment --
4482 -----------------------
4484 when Attribute_Maximum_Alignment
=>
4485 Standard_Attribute
(Ttypes
.Maximum_Alignment
);
4487 --------------------
4488 -- Mechanism_Code --
4489 --------------------
4491 when Attribute_Mechanism_Code
=>
4492 if not Is_Entity_Name
(P
)
4493 or else not Is_Subprogram
(Entity
(P
))
4495 Error_Attr_P
("prefix of % attribute must be subprogram");
4498 Check_Either_E0_Or_E1
;
4500 if Present
(E1
) then
4501 Resolve
(E1
, Any_Integer
);
4502 Set_Etype
(E1
, Standard_Integer
);
4504 if not Is_OK_Static_Expression
(E1
) then
4505 Flag_Non_Static_Expr
4506 ("expression for parameter number must be static!", E1
);
4509 elsif UI_To_Int
(Intval
(E1
)) > Number_Formals
(Entity
(P
))
4510 or else UI_To_Int
(Intval
(E1
)) < 0
4512 Error_Attr
("invalid parameter number for % attribute", E1
);
4516 Set_Etype
(N
, Universal_Integer
);
4522 when Attribute_Min
=>
4529 when Attribute_Mod
=>
4531 -- Note: this attribute is only allowed in Ada 2005 mode, but
4532 -- we do not need to test that here, since Mod is only recognized
4533 -- as an attribute name in Ada 2005 mode during the parse.
4536 Check_Modular_Integer_Type
;
4537 Resolve
(E1
, Any_Integer
);
4538 Set_Etype
(N
, P_Base_Type
);
4544 when Attribute_Model
=>
4545 Check_Floating_Point_Type_1
;
4546 Set_Etype
(N
, P_Base_Type
);
4547 Resolve
(E1
, P_Base_Type
);
4553 when Attribute_Model_Emin
=>
4554 Check_Floating_Point_Type_0
;
4555 Set_Etype
(N
, Universal_Integer
);
4561 when Attribute_Model_Epsilon
=>
4562 Check_Floating_Point_Type_0
;
4563 Set_Etype
(N
, Universal_Real
);
4565 --------------------
4566 -- Model_Mantissa --
4567 --------------------
4569 when Attribute_Model_Mantissa
=>
4570 Check_Floating_Point_Type_0
;
4571 Set_Etype
(N
, Universal_Integer
);
4577 when Attribute_Model_Small
=>
4578 Check_Floating_Point_Type_0
;
4579 Set_Etype
(N
, Universal_Real
);
4585 when Attribute_Modulus
=>
4587 Check_Modular_Integer_Type
;
4588 Set_Etype
(N
, Universal_Integer
);
4590 --------------------
4591 -- Null_Parameter --
4592 --------------------
4594 when Attribute_Null_Parameter
=> Null_Parameter
: declare
4595 Parnt
: constant Node_Id
:= Parent
(N
);
4596 GParnt
: constant Node_Id
:= Parent
(Parnt
);
4598 procedure Bad_Null_Parameter
(Msg
: String);
4599 -- Used if bad Null parameter attribute node is found. Issues
4600 -- given error message, and also sets the type to Any_Type to
4601 -- avoid blowups later on from dealing with a junk node.
4603 procedure Must_Be_Imported
(Proc_Ent
: Entity_Id
);
4604 -- Called to check that Proc_Ent is imported subprogram
4606 ------------------------
4607 -- Bad_Null_Parameter --
4608 ------------------------
4610 procedure Bad_Null_Parameter
(Msg
: String) is
4612 Error_Msg_N
(Msg
, N
);
4613 Set_Etype
(N
, Any_Type
);
4614 end Bad_Null_Parameter
;
4616 ----------------------
4617 -- Must_Be_Imported --
4618 ----------------------
4620 procedure Must_Be_Imported
(Proc_Ent
: Entity_Id
) is
4621 Pent
: constant Entity_Id
:= Ultimate_Alias
(Proc_Ent
);
4624 -- Ignore check if procedure not frozen yet (we will get
4625 -- another chance when the default parameter is reanalyzed)
4627 if not Is_Frozen
(Pent
) then
4630 elsif not Is_Imported
(Pent
) then
4632 ("Null_Parameter can only be used with imported subprogram");
4637 end Must_Be_Imported
;
4639 -- Start of processing for Null_Parameter
4644 Set_Etype
(N
, P_Type
);
4646 -- Case of attribute used as default expression
4648 if Nkind
(Parnt
) = N_Parameter_Specification
then
4649 Must_Be_Imported
(Defining_Entity
(GParnt
));
4651 -- Case of attribute used as actual for subprogram (positional)
4653 elsif Nkind
(Parnt
) in N_Subprogram_Call
4654 and then Is_Entity_Name
(Name
(Parnt
))
4656 Must_Be_Imported
(Entity
(Name
(Parnt
)));
4658 -- Case of attribute used as actual for subprogram (named)
4660 elsif Nkind
(Parnt
) = N_Parameter_Association
4661 and then Nkind
(GParnt
) in N_Subprogram_Call
4662 and then Is_Entity_Name
(Name
(GParnt
))
4664 Must_Be_Imported
(Entity
(Name
(GParnt
)));
4666 -- Not an allowed case
4670 ("Null_Parameter must be actual or default parameter");
4678 when Attribute_Object_Size
=>
4681 Check_Not_Incomplete_Type
;
4682 Set_Etype
(N
, Universal_Integer
);
4688 when Attribute_Old
=> Old
: declare
4689 procedure Check_References_In_Prefix
(Subp_Id
: Entity_Id
);
4690 -- Inspect the contents of the prefix and detect illegal uses of a
4691 -- nested 'Old, attribute 'Result or a use of an entity declared in
4692 -- the related postcondition expression. Subp_Id is the subprogram to
4693 -- which the related postcondition applies.
4695 --------------------------------
4696 -- Check_References_In_Prefix --
4697 --------------------------------
4699 procedure Check_References_In_Prefix
(Subp_Id
: Entity_Id
) is
4700 function Check_Reference
(Nod
: Node_Id
) return Traverse_Result
;
4701 -- Detect attribute 'Old, attribute 'Result of a use of an entity
4702 -- and perform the appropriate semantic check.
4704 ---------------------
4705 -- Check_Reference --
4706 ---------------------
4708 function Check_Reference
(Nod
: Node_Id
) return Traverse_Result
is
4710 -- Attributes 'Old and 'Result cannot appear in the prefix of
4711 -- another attribute 'Old.
4713 if Nkind
(Nod
) = N_Attribute_Reference
4714 and then Nam_In
(Attribute_Name
(Nod
), Name_Old
,
4717 Error_Msg_Name_1
:= Attribute_Name
(Nod
);
4718 Error_Msg_Name_2
:= Name_Old
;
4720 ("attribute % cannot appear in the prefix of attribute %",
4724 -- Entities mentioned within the prefix of attribute 'Old must
4725 -- be global to the related postcondition. If this is not the
4726 -- case, then the scope of the local entity is nested within
4727 -- that of the subprogram.
4729 elsif Is_Entity_Name
(Nod
)
4730 and then Present
(Entity
(Nod
))
4731 and then Scope_Within
(Scope
(Entity
(Nod
)), Subp_Id
)
4734 ("prefix of attribute % cannot reference local entities",
4738 -- Otherwise keep inspecting the prefix
4743 end Check_Reference
;
4745 procedure Check_References
is new Traverse_Proc
(Check_Reference
);
4747 -- Start of processing for Check_References_In_Prefix
4750 Check_References
(P
);
4751 end Check_References_In_Prefix
;
4756 Pref_Id
: Entity_Id
;
4757 Pref_Typ
: Entity_Id
;
4758 Spec_Id
: Entity_Id
;
4760 -- Start of processing for Old
4763 -- The attribute reference is a primary. If any expressions follow,
4764 -- then the attribute reference is an indexable object. Transform the
4765 -- attribute into an indexed component and analyze it.
4767 if Present
(E1
) then
4769 Make_Indexed_Component
(Loc
,
4771 Make_Attribute_Reference
(Loc
,
4772 Prefix
=> Relocate_Node
(P
),
4773 Attribute_Name
=> Name_Old
),
4774 Expressions
=> Expressions
(N
)));
4779 Analyze_Attribute_Old_Result
(Legal
, Spec_Id
);
4781 -- The aspect or pragma where attribute 'Old resides should be
4782 -- associated with a subprogram declaration or a body. If this is not
4783 -- the case, then the aspect or pragma is illegal. Return as analysis
4784 -- cannot be carried out.
4790 -- The prefix must be preanalyzed as the full analysis will take
4791 -- place during expansion.
4793 Preanalyze_And_Resolve
(P
);
4795 -- Ensure that the prefix does not contain attributes 'Old or 'Result
4797 Check_References_In_Prefix
(Spec_Id
);
4799 -- Set the type of the attribute now to prevent cascaded errors
4801 Pref_Typ
:= Etype
(P
);
4802 Set_Etype
(N
, Pref_Typ
);
4806 if Is_Limited_Type
(Pref_Typ
) then
4807 Error_Attr
("attribute % cannot apply to limited objects", P
);
4810 -- The prefix is a simple name
4812 if Is_Entity_Name
(P
) and then Present
(Entity
(P
)) then
4813 Pref_Id
:= Entity
(P
);
4815 -- Emit a warning when the prefix is a constant. Note that the use
4816 -- of Error_Attr would reset the type of N to Any_Type even though
4817 -- this is a warning. Use Error_Msg_XXX instead.
4819 if Is_Constant_Object
(Pref_Id
) then
4820 Error_Msg_Name_1
:= Name_Old
;
4822 ("??attribute % applied to constant has no effect", P
);
4825 -- Otherwise the prefix is not a simple name
4828 -- Ensure that the prefix of attribute 'Old is an entity when it
4829 -- is potentially unevaluated (6.1.1 (27/3)).
4831 if Is_Potentially_Unevaluated
(N
) then
4834 -- Detect a possible infinite recursion when the prefix denotes
4835 -- the related function.
4837 -- function Func (...) return ...
4838 -- with Post => Func'Old ...;
4840 elsif Nkind
(P
) = N_Function_Call
then
4841 Pref_Id
:= Entity
(Name
(P
));
4843 if Ekind_In
(Spec_Id
, E_Function
, E_Generic_Function
)
4844 and then Pref_Id
= Spec_Id
4846 Error_Msg_Warn
:= SPARK_Mode
/= On
;
4847 Error_Msg_N
("!possible infinite recursion<<", P
);
4848 Error_Msg_N
("\!??Storage_Error ]<<", P
);
4852 -- The prefix of attribute 'Old may refer to a component of a
4853 -- formal parameter. In this case its expansion may generate
4854 -- actual subtypes that are referenced in an inner context and
4855 -- that must be elaborated within the subprogram itself. If the
4856 -- prefix includes a function call, it may involve finalization
4857 -- actions that should be inserted when the attribute has been
4858 -- rewritten as a declaration. Create a declaration for the prefix
4859 -- and insert it at the start of the enclosing subprogram. This is
4860 -- an expansion activity that has to be performed now to prevent
4861 -- out-of-order issues.
4863 -- This expansion is both harmful and not needed in SPARK mode,
4864 -- since the formal verification backend relies on the types of
4865 -- nodes (hence is not robust w.r.t. a change to base type here),
4866 -- and does not suffer from the out-of-order issue described
4867 -- above. Thus, this expansion is skipped in SPARK mode.
4869 if not GNATprove_Mode
then
4870 Pref_Typ
:= Base_Type
(Pref_Typ
);
4871 Set_Etype
(N
, Pref_Typ
);
4872 Set_Etype
(P
, Pref_Typ
);
4874 Analyze_Dimension
(N
);
4880 ----------------------
4881 -- Overlaps_Storage --
4882 ----------------------
4884 when Attribute_Overlaps_Storage
=>
4887 -- Both arguments must be objects of any type
4889 Analyze_And_Resolve
(P
);
4890 Analyze_And_Resolve
(E1
);
4891 Check_Object_Reference
(P
);
4892 Check_Object_Reference
(E1
);
4893 Set_Etype
(N
, Standard_Boolean
);
4899 when Attribute_Output
=>
4901 Check_Stream_Attribute
(TSS_Stream_Output
);
4902 Set_Etype
(N
, Standard_Void_Type
);
4903 Resolve
(N
, Standard_Void_Type
);
4909 when Attribute_Partition_ID
=> Partition_Id
:
4913 if P_Type
/= Any_Type
then
4914 if not Is_Library_Level_Entity
(Entity
(P
)) then
4916 ("prefix of % attribute must be library-level entity");
4918 -- The defining entity of prefix should not be declared inside a
4919 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
4921 elsif Is_Entity_Name
(P
)
4922 and then Is_Pure
(Entity
(P
))
4924 Error_Attr_P
("prefix of% attribute must not be declared pure");
4928 Set_Etype
(N
, Universal_Integer
);
4931 -------------------------
4932 -- Passed_By_Reference --
4933 -------------------------
4935 when Attribute_Passed_By_Reference
=>
4938 Set_Etype
(N
, Standard_Boolean
);
4944 when Attribute_Pool_Address
=>
4946 Set_Etype
(N
, RTE
(RE_Address
));
4952 when Attribute_Pos
=>
4953 Check_Discrete_Type
;
4956 if Is_Boolean_Type
(P_Type
) then
4957 Error_Msg_Name_1
:= Aname
;
4958 Error_Msg_Name_2
:= Chars
(P_Type
);
4959 Check_SPARK_05_Restriction
4960 ("attribute% is not allowed for type%", P
);
4963 Resolve
(E1
, P_Base_Type
);
4964 Set_Etype
(N
, Universal_Integer
);
4970 when Attribute_Position
=>
4972 Set_Etype
(N
, Universal_Integer
);
4978 when Attribute_Pred
=>
4982 if Is_Real_Type
(P_Type
) or else Is_Boolean_Type
(P_Type
) then
4983 Error_Msg_Name_1
:= Aname
;
4984 Error_Msg_Name_2
:= Chars
(P_Type
);
4985 Check_SPARK_05_Restriction
4986 ("attribute% is not allowed for type%", P
);
4989 Resolve
(E1
, P_Base_Type
);
4990 Set_Etype
(N
, P_Base_Type
);
4992 -- Since Pred works on the base type, we normally do no check for the
4993 -- floating-point case, since the base type is unconstrained. But we
4994 -- make an exception in Check_Float_Overflow mode.
4996 if Is_Floating_Point_Type
(P_Type
) then
4997 if not Range_Checks_Suppressed
(P_Base_Type
) then
4998 Set_Do_Range_Check
(E1
);
5001 -- If not modular type, test for overflow check required
5004 if not Is_Modular_Integer_Type
(P_Type
)
5005 and then not Range_Checks_Suppressed
(P_Base_Type
)
5007 Enable_Range_Check
(E1
);
5015 -- Ada 2005 (AI-327): Dynamic ceiling priorities
5017 when Attribute_Priority
=>
5018 if Ada_Version
< Ada_2005
then
5019 Error_Attr
("% attribute is allowed only in Ada 2005 mode", P
);
5024 -- The prefix must be a protected object (AARM D.5.2 (2/2))
5028 if Is_Protected_Type
(Etype
(P
))
5029 or else (Is_Access_Type
(Etype
(P
))
5030 and then Is_Protected_Type
(Designated_Type
(Etype
(P
))))
5032 Resolve
(P
, Etype
(P
));
5034 Error_Attr_P
("prefix of % attribute must be a protected object");
5037 Set_Etype
(N
, Standard_Integer
);
5039 -- Must be called from within a protected procedure or entry of the
5040 -- protected object.
5047 while S
/= Etype
(P
)
5048 and then S
/= Standard_Standard
5053 if S
= Standard_Standard
then
5054 Error_Attr
("the attribute % is only allowed inside protected "
5059 Validate_Non_Static_Attribute_Function_Call
;
5065 when Attribute_Range
=>
5066 Check_Array_Or_Scalar_Type
;
5067 Bad_Attribute_For_Predicate
;
5069 if Ada_Version
= Ada_83
5070 and then Is_Scalar_Type
(P_Type
)
5071 and then Comes_From_Source
(N
)
5074 ("(Ada 83) % attribute not allowed for scalar type", P
);
5081 when Attribute_Result
=> Result
: declare
5082 function Denote_Same_Function
5083 (Pref_Id
: Entity_Id
;
5084 Spec_Id
: Entity_Id
) return Boolean;
5085 -- Determine whether the entity of the prefix Pref_Id denotes the
5086 -- same entity as that of the related subprogram Spec_Id.
5088 --------------------------
5089 -- Denote_Same_Function --
5090 --------------------------
5092 function Denote_Same_Function
5093 (Pref_Id
: Entity_Id
;
5094 Spec_Id
: Entity_Id
) return Boolean
5096 Subp_Spec
: constant Node_Id
:= Parent
(Spec_Id
);
5099 -- The prefix denotes the related subprogram
5101 if Pref_Id
= Spec_Id
then
5104 -- Account for a special case when attribute 'Result appears in
5105 -- the postcondition of a generic function.
5108 -- function Gen_Func return ...
5109 -- with Post => Gen_Func'Result ...;
5111 -- When the generic function is instantiated, the Chars field of
5112 -- the instantiated prefix still denotes the name of the generic
5113 -- function. Note that any preemptive transformation is impossible
5114 -- without a proper analysis. The structure of the wrapper package
5117 -- package Anon_Gen_Pack is
5118 -- <subtypes and renamings>
5119 -- function Subp_Decl return ...; -- (!)
5120 -- pragma Postcondition (Gen_Func'Result ...); -- (!)
5121 -- function Gen_Func ... renames Subp_Decl;
5122 -- end Anon_Gen_Pack;
5124 elsif Nkind
(Subp_Spec
) = N_Function_Specification
5125 and then Present
(Generic_Parent
(Subp_Spec
))
5126 and then Ekind
(Pref_Id
) = E_Function
5127 and then Present
(Alias
(Pref_Id
))
5128 and then Alias
(Pref_Id
) = Spec_Id
5132 -- Otherwise the prefix does not denote the related subprogram
5137 end Denote_Same_Function
;
5142 Pref_Id
: Entity_Id
;
5143 Spec_Id
: Entity_Id
;
5145 -- Start of processing for Result
5148 -- The attribute reference is a primary. If any expressions follow,
5149 -- then the attribute reference is an indexable object. Transform the
5150 -- attribute into an indexed component and analyze it.
5152 if Present
(E1
) then
5154 Make_Indexed_Component
(Loc
,
5156 Make_Attribute_Reference
(Loc
,
5157 Prefix
=> Relocate_Node
(P
),
5158 Attribute_Name
=> Name_Result
),
5159 Expressions
=> Expressions
(N
)));
5164 Analyze_Attribute_Old_Result
(Legal
, Spec_Id
);
5166 -- The aspect or pragma where attribute 'Result resides should be
5167 -- associated with a subprogram declaration or a body. If this is not
5168 -- the case, then the aspect or pragma is illegal. Return as analysis
5169 -- cannot be carried out.
5175 -- Attribute 'Result is part of a _Postconditions procedure. There is
5176 -- no need to perform the semantic checks below as they were already
5177 -- verified when the attribute was analyzed in its original context.
5178 -- Instead, rewrite the attribute as a reference to formal parameter
5179 -- _Result of the _Postconditions procedure.
5181 if Chars
(Spec_Id
) = Name_uPostconditions
then
5182 Rewrite
(N
, Make_Identifier
(Loc
, Name_uResult
));
5184 -- The type of formal parameter _Result is that of the function
5185 -- encapsulating the _Postconditions procedure. Resolution must
5186 -- be carried out against the function return type.
5188 Analyze_And_Resolve
(N
, Etype
(Scope
(Spec_Id
)));
5190 -- Otherwise attribute 'Result appears in its original context and
5191 -- all semantic checks should be carried out.
5194 -- Verify the legality of the prefix. It must denotes the entity
5195 -- of the related [generic] function.
5197 if Is_Entity_Name
(P
) then
5198 Pref_Id
:= Entity
(P
);
5200 if Ekind_In
(Pref_Id
, E_Function
, E_Generic_Function
) then
5201 if Denote_Same_Function
(Pref_Id
, Spec_Id
) then
5202 Set_Etype
(N
, Etype
(Spec_Id
));
5204 -- Otherwise the prefix denotes some unrelated function
5207 Error_Msg_Name_2
:= Chars
(Spec_Id
);
5209 ("incorrect prefix for attribute %, expected %", P
);
5212 -- Otherwise the prefix denotes some other form of subprogram
5217 ("attribute % can only appear in postcondition of "
5221 -- Otherwise the prefix is illegal
5224 Error_Msg_Name_2
:= Chars
(Spec_Id
);
5225 Error_Attr
("incorrect prefix for attribute %, expected %", P
);
5234 when Attribute_Range_Length
=>
5236 Check_Discrete_Type
;
5237 Set_Etype
(N
, Universal_Integer
);
5243 when Attribute_Read
=>
5245 Check_Stream_Attribute
(TSS_Stream_Read
);
5246 Set_Etype
(N
, Standard_Void_Type
);
5247 Resolve
(N
, Standard_Void_Type
);
5248 Note_Possible_Modification
(E2
, Sure
=> True);
5254 when Attribute_Ref
=>
5258 if Nkind
(P
) /= N_Expanded_Name
5259 or else not Is_RTE
(P_Type
, RE_Address
)
5261 Error_Attr_P
("prefix of % attribute must be System.Address");
5264 Analyze_And_Resolve
(E1
, Any_Integer
);
5265 Set_Etype
(N
, RTE
(RE_Address
));
5271 when Attribute_Remainder
=>
5272 Check_Floating_Point_Type_2
;
5273 Set_Etype
(N
, P_Base_Type
);
5274 Resolve
(E1
, P_Base_Type
);
5275 Resolve
(E2
, P_Base_Type
);
5277 ---------------------
5278 -- Restriction_Set --
5279 ---------------------
5281 when Attribute_Restriction_Set
=> Restriction_Set
: declare
5284 Unam
: Unit_Name_Type
;
5289 Check_System_Prefix
;
5291 -- No_Dependence case
5293 if Nkind
(E1
) = N_Parameter_Association
then
5294 pragma Assert
(Chars
(Selector_Name
(E1
)) = Name_No_Dependence
);
5295 U
:= Explicit_Actual_Parameter
(E1
);
5297 if not OK_No_Dependence_Unit_Name
(U
) then
5298 Set_Boolean_Result
(N
, False);
5302 -- See if there is an entry already in the table. That's the
5303 -- case in which we can return True.
5305 for J
in No_Dependences
.First
.. No_Dependences
.Last
loop
5306 if Designate_Same_Unit
(U
, No_Dependences
.Table
(J
).Unit
)
5307 and then No_Dependences
.Table
(J
).Warn
= False
5309 Set_Boolean_Result
(N
, True);
5314 -- If not in the No_Dependence table, result is False
5316 Set_Boolean_Result
(N
, False);
5318 -- In this case, we must ensure that the binder will reject any
5319 -- other unit in the partition that sets No_Dependence for this
5320 -- unit. We do that by making an entry in the special table kept
5321 -- for this purpose (if the entry is not there already).
5323 Unam
:= Get_Spec_Name
(Get_Unit_Name
(U
));
5325 for J
in Restriction_Set_Dependences
.First
..
5326 Restriction_Set_Dependences
.Last
5328 if Restriction_Set_Dependences
.Table
(J
) = Unam
then
5333 Restriction_Set_Dependences
.Append
(Unam
);
5335 -- Normal restriction case
5338 if Nkind
(E1
) /= N_Identifier
then
5339 Set_Boolean_Result
(N
, False);
5340 Error_Attr
("attribute % requires restriction identifier", E1
);
5343 R
:= Get_Restriction_Id
(Process_Restriction_Synonyms
(E1
));
5345 if R
= Not_A_Restriction_Id
then
5346 Set_Boolean_Result
(N
, False);
5347 Error_Msg_Node_1
:= E1
;
5348 Error_Attr
("invalid restriction identifier &", E1
);
5350 elsif R
not in Partition_Boolean_Restrictions
then
5351 Set_Boolean_Result
(N
, False);
5352 Error_Msg_Node_1
:= E1
;
5354 ("& is not a boolean partition-wide restriction", E1
);
5357 if Restriction_Active
(R
) then
5358 Set_Boolean_Result
(N
, True);
5360 Check_Restriction
(R
, N
);
5361 Set_Boolean_Result
(N
, False);
5365 end Restriction_Set
;
5371 when Attribute_Round
=>
5373 Check_Decimal_Fixed_Point_Type
;
5374 Set_Etype
(N
, P_Base_Type
);
5376 -- Because the context is universal_real (3.5.10(12)) it is a
5377 -- legal context for a universal fixed expression. This is the
5378 -- only attribute whose functional description involves U_R.
5380 if Etype
(E1
) = Universal_Fixed
then
5382 Conv
: constant Node_Id
:= Make_Type_Conversion
(Loc
,
5383 Subtype_Mark
=> New_Occurrence_Of
(Universal_Real
, Loc
),
5384 Expression
=> Relocate_Node
(E1
));
5392 Resolve
(E1
, Any_Real
);
5398 when Attribute_Rounding
=>
5399 Check_Floating_Point_Type_1
;
5400 Set_Etype
(N
, P_Base_Type
);
5401 Resolve
(E1
, P_Base_Type
);
5407 when Attribute_Safe_Emax
=>
5408 Check_Floating_Point_Type_0
;
5409 Set_Etype
(N
, Universal_Integer
);
5415 when Attribute_Safe_First
=>
5416 Check_Floating_Point_Type_0
;
5417 Set_Etype
(N
, Universal_Real
);
5423 when Attribute_Safe_Large
=>
5426 Set_Etype
(N
, Universal_Real
);
5432 when Attribute_Safe_Last
=>
5433 Check_Floating_Point_Type_0
;
5434 Set_Etype
(N
, Universal_Real
);
5440 when Attribute_Safe_Small
=>
5443 Set_Etype
(N
, Universal_Real
);
5445 --------------------------
5446 -- Scalar_Storage_Order --
5447 --------------------------
5449 when Attribute_Scalar_Storage_Order
=> Scalar_Storage_Order
:
5451 Ent
: Entity_Id
:= Empty
;
5457 if not (Is_Record_Type
(P_Type
) or else Is_Array_Type
(P_Type
)) then
5459 -- In GNAT mode, the attribute applies to generic types as well
5460 -- as composite types, and for non-composite types always returns
5461 -- the default bit order for the target.
5463 if not (GNAT_Mode
and then Is_Generic_Type
(P_Type
))
5464 and then not In_Instance
5467 ("prefix of % attribute must be record or array type");
5469 elsif not Is_Generic_Type
(P_Type
) then
5470 if Bytes_Big_Endian
then
5471 Ent
:= RTE
(RE_High_Order_First
);
5473 Ent
:= RTE
(RE_Low_Order_First
);
5477 elsif Bytes_Big_Endian
xor Reverse_Storage_Order
(P_Type
) then
5478 Ent
:= RTE
(RE_High_Order_First
);
5481 Ent
:= RTE
(RE_Low_Order_First
);
5484 if Present
(Ent
) then
5485 Rewrite
(N
, New_Occurrence_Of
(Ent
, Loc
));
5488 Set_Etype
(N
, RTE
(RE_Bit_Order
));
5491 -- Reset incorrect indication of staticness
5493 Set_Is_Static_Expression
(N
, False);
5494 end Scalar_Storage_Order
;
5500 when Attribute_Scale
=>
5502 Check_Decimal_Fixed_Point_Type
;
5503 Set_Etype
(N
, Universal_Integer
);
5509 when Attribute_Scaling
=>
5510 Check_Floating_Point_Type_2
;
5511 Set_Etype
(N
, P_Base_Type
);
5512 Resolve
(E1
, P_Base_Type
);
5518 when Attribute_Signed_Zeros
=>
5519 Check_Floating_Point_Type_0
;
5520 Set_Etype
(N
, Standard_Boolean
);
5526 when Attribute_Size | Attribute_VADS_Size
=> Size
:
5530 -- If prefix is parameterless function call, rewrite and resolve
5533 if Is_Entity_Name
(P
)
5534 and then Ekind
(Entity
(P
)) = E_Function
5538 -- Similar processing for a protected function call
5540 elsif Nkind
(P
) = N_Selected_Component
5541 and then Ekind
(Entity
(Selector_Name
(P
))) = E_Function
5546 if Is_Object_Reference
(P
) then
5547 Check_Object_Reference
(P
);
5549 elsif Is_Entity_Name
(P
)
5550 and then (Is_Type
(Entity
(P
))
5551 or else Ekind
(Entity
(P
)) = E_Enumeration_Literal
)
5555 elsif Nkind
(P
) = N_Type_Conversion
5556 and then not Comes_From_Source
(P
)
5560 -- Some other compilers allow dubious use of X'???'Size
5562 elsif Relaxed_RM_Semantics
5563 and then Nkind
(P
) = N_Attribute_Reference
5568 Error_Attr_P
("invalid prefix for % attribute");
5571 Check_Not_Incomplete_Type
;
5573 Set_Etype
(N
, Universal_Integer
);
5580 when Attribute_Small
=>
5583 Set_Etype
(N
, Universal_Real
);
5589 when Attribute_Storage_Pool |
5590 Attribute_Simple_Storage_Pool
=> Storage_Pool
:
5594 if Is_Access_Type
(P_Type
) then
5595 if Ekind
(P_Type
) = E_Access_Subprogram_Type
then
5597 ("cannot use % attribute for access-to-subprogram type");
5600 -- Set appropriate entity
5602 if Present
(Associated_Storage_Pool
(Root_Type
(P_Type
))) then
5603 Set_Entity
(N
, Associated_Storage_Pool
(Root_Type
(P_Type
)));
5605 Set_Entity
(N
, RTE
(RE_Global_Pool_Object
));
5608 if Attr_Id
= Attribute_Storage_Pool
then
5609 if Present
(Get_Rep_Pragma
(Etype
(Entity
(N
)),
5610 Name_Simple_Storage_Pool_Type
))
5612 Error_Msg_Name_1
:= Aname
;
5613 Error_Msg_Warn
:= SPARK_Mode
/= On
;
5614 Error_Msg_N
("cannot use % attribute for type with simple "
5615 & "storage pool<<", N
);
5616 Error_Msg_N
("\Program_Error [<<", N
);
5619 (N
, Make_Raise_Program_Error
5620 (Sloc
(N
), Reason
=> PE_Explicit_Raise
));
5623 Set_Etype
(N
, Class_Wide_Type
(RTE
(RE_Root_Storage_Pool
)));
5625 -- In the Simple_Storage_Pool case, verify that the pool entity is
5626 -- actually of a simple storage pool type, and set the attribute's
5627 -- type to the pool object's type.
5630 if not Present
(Get_Rep_Pragma
(Etype
(Entity
(N
)),
5631 Name_Simple_Storage_Pool_Type
))
5634 ("cannot use % attribute for type without simple " &
5638 Set_Etype
(N
, Etype
(Entity
(N
)));
5641 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
5642 -- Storage_Pool since this attribute is not defined for such
5643 -- types (RM E.2.3(22)).
5645 Validate_Remote_Access_To_Class_Wide_Type
(N
);
5648 Error_Attr_P
("prefix of % attribute must be access type");
5656 when Attribute_Storage_Size
=> Storage_Size
:
5660 if Is_Task_Type
(P_Type
) then
5661 Set_Etype
(N
, Universal_Integer
);
5663 -- Use with tasks is an obsolescent feature
5665 Check_Restriction
(No_Obsolescent_Features
, P
);
5667 elsif Is_Access_Type
(P_Type
) then
5668 if Ekind
(P_Type
) = E_Access_Subprogram_Type
then
5670 ("cannot use % attribute for access-to-subprogram type");
5673 if Is_Entity_Name
(P
)
5674 and then Is_Type
(Entity
(P
))
5677 Set_Etype
(N
, Universal_Integer
);
5679 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
5680 -- Storage_Size since this attribute is not defined for
5681 -- such types (RM E.2.3(22)).
5683 Validate_Remote_Access_To_Class_Wide_Type
(N
);
5685 -- The prefix is allowed to be an implicit dereference of an
5686 -- access value designating a task.
5690 Set_Etype
(N
, Universal_Integer
);
5694 Error_Attr_P
("prefix of % attribute must be access or task type");
5702 when Attribute_Storage_Unit
=>
5703 Standard_Attribute
(Ttypes
.System_Storage_Unit
);
5709 when Attribute_Stream_Size
=>
5713 if Is_Entity_Name
(P
)
5714 and then Is_Elementary_Type
(Entity
(P
))
5716 Set_Etype
(N
, Universal_Integer
);
5718 Error_Attr_P
("invalid prefix for % attribute");
5725 when Attribute_Stub_Type
=>
5729 if Is_Remote_Access_To_Class_Wide_Type
(Base_Type
(P_Type
)) then
5731 -- For a real RACW [sub]type, use corresponding stub type
5733 if not Is_Generic_Type
(P_Type
) then
5736 (Corresponding_Stub_Type
(Base_Type
(P_Type
)), Loc
));
5738 -- For a generic type (that has been marked as an RACW using the
5739 -- Remote_Access_Type aspect or pragma), use a generic RACW stub
5740 -- type. Note that if the actual is not a remote access type, the
5741 -- instantiation will fail.
5744 -- Note: we go to the underlying type here because the view
5745 -- returned by RTE (RE_RACW_Stub_Type) might be incomplete.
5749 (Underlying_Type
(RTE
(RE_RACW_Stub_Type
)), Loc
));
5754 ("prefix of% attribute must be remote access to classwide");
5761 when Attribute_Succ
=>
5765 if Is_Real_Type
(P_Type
) or else Is_Boolean_Type
(P_Type
) then
5766 Error_Msg_Name_1
:= Aname
;
5767 Error_Msg_Name_2
:= Chars
(P_Type
);
5768 Check_SPARK_05_Restriction
5769 ("attribute% is not allowed for type%", P
);
5772 Resolve
(E1
, P_Base_Type
);
5773 Set_Etype
(N
, P_Base_Type
);
5775 -- Since Pred works on the base type, we normally do no check for the
5776 -- floating-point case, since the base type is unconstrained. But we
5777 -- make an exception in Check_Float_Overflow mode.
5779 if Is_Floating_Point_Type
(P_Type
) then
5780 if not Range_Checks_Suppressed
(P_Base_Type
) then
5781 Set_Do_Range_Check
(E1
);
5784 -- If not modular type, test for overflow check required
5787 if not Is_Modular_Integer_Type
(P_Type
)
5788 and then not Range_Checks_Suppressed
(P_Base_Type
)
5790 Enable_Range_Check
(E1
);
5794 --------------------------------
5795 -- System_Allocator_Alignment --
5796 --------------------------------
5798 when Attribute_System_Allocator_Alignment
=>
5799 Standard_Attribute
(Ttypes
.System_Allocator_Alignment
);
5805 when Attribute_Tag
=> Tag
:
5810 if not Is_Tagged_Type
(P_Type
) then
5811 Error_Attr_P
("prefix of % attribute must be tagged");
5813 -- Next test does not apply to generated code why not, and what does
5814 -- the illegal reference mean???
5816 elsif Is_Object_Reference
(P
)
5817 and then not Is_Class_Wide_Type
(P_Type
)
5818 and then Comes_From_Source
(N
)
5821 ("% attribute can only be applied to objects " &
5822 "of class - wide type");
5825 -- The prefix cannot be an incomplete type. However, references to
5826 -- 'Tag can be generated when expanding interface conversions, and
5829 if Comes_From_Source
(N
) then
5830 Check_Not_Incomplete_Type
;
5833 -- Set appropriate type
5835 Set_Etype
(N
, RTE
(RE_Tag
));
5842 when Attribute_Target_Name
=> Target_Name
: declare
5843 TN
: constant String := Sdefault
.Target_Name
.all;
5847 Check_Standard_Prefix
;
5851 if TN
(TL
) = '/' or else TN
(TL
) = '\' then
5856 Make_String_Literal
(Loc
,
5857 Strval
=> TN
(TN
'First .. TL
)));
5858 Analyze_And_Resolve
(N
, Standard_String
);
5859 Set_Is_Static_Expression
(N
, True);
5866 when Attribute_Terminated
=>
5868 Set_Etype
(N
, Standard_Boolean
);
5875 when Attribute_To_Address
=> To_Address
: declare
5881 Check_System_Prefix
;
5883 Generate_Reference
(RTE
(RE_Address
), P
);
5884 Analyze_And_Resolve
(E1
, Any_Integer
);
5885 Set_Etype
(N
, RTE
(RE_Address
));
5887 if Is_Static_Expression
(E1
) then
5888 Set_Is_Static_Expression
(N
, True);
5891 -- OK static expression case, check range and set appropriate type
5893 if Is_OK_Static_Expression
(E1
) then
5894 Val
:= Expr_Value
(E1
);
5896 if Val
< -(2 ** UI_From_Int
(Standard
'Address_Size - 1))
5898 Val
> 2 ** UI_From_Int
(Standard
'Address_Size) - 1
5900 Error_Attr
("address value out of range for % attribute", E1
);
5903 -- In most cases the expression is a numeric literal or some other
5904 -- address expression, but if it is a declared constant it may be
5905 -- of a compatible type that must be left on the node.
5907 if Is_Entity_Name
(E1
) then
5910 -- Set type to universal integer if negative
5913 Set_Etype
(E1
, Universal_Integer
);
5915 -- Otherwise set type to Unsigned_64 to accomodate max values
5918 Set_Etype
(E1
, Standard_Unsigned_64
);
5922 Set_Is_Static_Expression
(N
, True);
5929 when Attribute_To_Any
=>
5931 Check_PolyORB_Attribute
;
5932 Set_Etype
(N
, RTE
(RE_Any
));
5938 when Attribute_Truncation
=>
5939 Check_Floating_Point_Type_1
;
5940 Resolve
(E1
, P_Base_Type
);
5941 Set_Etype
(N
, P_Base_Type
);
5947 when Attribute_Type_Class
=>
5950 Check_Not_Incomplete_Type
;
5951 Set_Etype
(N
, RTE
(RE_Type_Class
));
5957 when Attribute_TypeCode
=>
5959 Check_PolyORB_Attribute
;
5960 Set_Etype
(N
, RTE
(RE_TypeCode
));
5966 when Attribute_Type_Key
=>
5970 -- This processing belongs in Eval_Attribute ???
5973 function Type_Key
return String_Id
;
5974 -- A very preliminary implementation. For now, a signature
5975 -- consists of only the type name. This is clearly incomplete
5976 -- (e.g., adding a new field to a record type should change the
5977 -- type's Type_Key attribute).
5983 function Type_Key
return String_Id
is
5984 Full_Name
: constant String_Id
:=
5985 Fully_Qualified_Name_String
(Entity
(P
));
5988 -- Copy all characters in Full_Name but the trailing NUL
5991 for J
in 1 .. String_Length
(Full_Name
) - 1 loop
5992 Store_String_Char
(Get_String_Char
(Full_Name
, Int
(J
)));
5995 Store_String_Chars
("'Type_Key");
6000 Rewrite
(N
, Make_String_Literal
(Loc
, Type_Key
));
6003 Analyze_And_Resolve
(N
, Standard_String
);
6009 when Attribute_UET_Address
=>
6011 Check_Unit_Name
(P
);
6012 Set_Etype
(N
, RTE
(RE_Address
));
6014 -----------------------
6015 -- Unbiased_Rounding --
6016 -----------------------
6018 when Attribute_Unbiased_Rounding
=>
6019 Check_Floating_Point_Type_1
;
6020 Set_Etype
(N
, P_Base_Type
);
6021 Resolve
(E1
, P_Base_Type
);
6023 ----------------------
6024 -- Unchecked_Access --
6025 ----------------------
6027 when Attribute_Unchecked_Access
=>
6028 if Comes_From_Source
(N
) then
6029 Check_Restriction
(No_Unchecked_Access
, N
);
6032 Analyze_Access_Attribute
;
6033 Check_Not_Incomplete_Type
;
6035 -------------------------
6036 -- Unconstrained_Array --
6037 -------------------------
6039 when Attribute_Unconstrained_Array
=>
6042 Check_Not_Incomplete_Type
;
6043 Set_Etype
(N
, Standard_Boolean
);
6044 Set_Is_Static_Expression
(N
, True);
6046 ------------------------------
6047 -- Universal_Literal_String --
6048 ------------------------------
6050 -- This is a GNAT specific attribute whose prefix must be a named
6051 -- number where the expression is either a single numeric literal,
6052 -- or a numeric literal immediately preceded by a minus sign. The
6053 -- result is equivalent to a string literal containing the text of
6054 -- the literal as it appeared in the source program with a possible
6055 -- leading minus sign.
6057 when Attribute_Universal_Literal_String
=> Universal_Literal_String
:
6061 if not Is_Entity_Name
(P
)
6062 or else Ekind
(Entity
(P
)) not in Named_Kind
6064 Error_Attr_P
("prefix for % attribute must be named number");
6071 Src
: Source_Buffer_Ptr
;
6074 Expr
:= Original_Node
(Expression
(Parent
(Entity
(P
))));
6076 if Nkind
(Expr
) = N_Op_Minus
then
6078 Expr
:= Original_Node
(Right_Opnd
(Expr
));
6083 if not Nkind_In
(Expr
, N_Integer_Literal
, N_Real_Literal
) then
6085 ("named number for % attribute must be simple literal", N
);
6088 -- Build string literal corresponding to source literal text
6093 Store_String_Char
(Get_Char_Code
('-'));
6097 Src
:= Source_Text
(Get_Source_File_Index
(S
));
6099 while Src
(S
) /= ';' and then Src
(S
) /= ' ' loop
6100 Store_String_Char
(Get_Char_Code
(Src
(S
)));
6104 -- Now we rewrite the attribute with the string literal
6107 Make_String_Literal
(Loc
, End_String
));
6109 Set_Is_Static_Expression
(N
, True);
6112 end Universal_Literal_String
;
6114 -------------------------
6115 -- Unrestricted_Access --
6116 -------------------------
6118 -- This is a GNAT specific attribute which is like Access except that
6119 -- all scope checks and checks for aliased views are omitted. It is
6120 -- documented as being equivalent to the use of the Address attribute
6121 -- followed by an unchecked conversion to the target access type.
6123 when Attribute_Unrestricted_Access
=>
6125 -- If from source, deal with relevant restrictions
6127 if Comes_From_Source
(N
) then
6128 Check_Restriction
(No_Unchecked_Access
, N
);
6130 if Nkind
(P
) in N_Has_Entity
6131 and then Present
(Entity
(P
))
6132 and then Is_Object
(Entity
(P
))
6134 Check_Restriction
(No_Implicit_Aliasing
, N
);
6138 if Is_Entity_Name
(P
) then
6139 Set_Address_Taken
(Entity
(P
));
6142 -- It might seem reasonable to call Address_Checks here to apply the
6143 -- same set of semantic checks that we enforce for 'Address (after
6144 -- all we document Unrestricted_Access as being equivalent to the
6145 -- use of Address followed by an Unchecked_Conversion). However, if
6146 -- we do enable these checks, we get multiple failures in both the
6147 -- compiler run-time and in our regression test suite, so we leave
6148 -- out these checks for now. To be investigated further some time???
6152 -- Now complete analysis using common access processing
6154 Analyze_Access_Attribute
;
6160 when Attribute_Update
=> Update
: declare
6161 Common_Typ
: Entity_Id
;
6162 -- The common type of a multiple component update for a record
6164 Comps
: Elist_Id
:= No_Elist
;
6165 -- A list used in the resolution of a record update. It contains the
6166 -- entities of all record components processed so far.
6168 procedure Analyze_Array_Component_Update
(Assoc
: Node_Id
);
6169 -- Analyze and resolve array_component_association Assoc against the
6170 -- index of array type P_Type.
6172 procedure Analyze_Record_Component_Update
(Comp
: Node_Id
);
6173 -- Analyze and resolve record_component_association Comp against
6174 -- record type P_Type.
6176 ------------------------------------
6177 -- Analyze_Array_Component_Update --
6178 ------------------------------------
6180 procedure Analyze_Array_Component_Update
(Assoc
: Node_Id
) is
6184 Index_Typ
: Entity_Id
;
6188 -- The current association contains a sequence of indexes denoting
6189 -- an element of a multidimensional array:
6191 -- (Index_1, ..., Index_N)
6193 -- Examine each individual index and resolve it against the proper
6194 -- index type of the array.
6196 if Nkind
(First
(Choices
(Assoc
))) = N_Aggregate
then
6197 Expr
:= First
(Choices
(Assoc
));
6198 while Present
(Expr
) loop
6200 -- The use of others is illegal (SPARK RM 4.4.1(12))
6202 if Nkind
(Expr
) = N_Others_Choice
then
6204 ("others choice not allowed in attribute %", Expr
);
6206 -- Otherwise analyze and resolve all indexes
6209 Index
:= First
(Expressions
(Expr
));
6210 Index_Typ
:= First_Index
(P_Type
);
6211 while Present
(Index
) and then Present
(Index_Typ
) loop
6212 Analyze_And_Resolve
(Index
, Etype
(Index_Typ
));
6214 Next_Index
(Index_Typ
);
6217 -- Detect a case where the association either lacks an
6218 -- index or contains an extra index.
6220 if Present
(Index
) or else Present
(Index_Typ
) then
6222 ("dimension mismatch in index list", Assoc
);
6229 -- The current association denotes either a single component or a
6230 -- range of components of a one dimensional array:
6234 -- Resolve the index or its high and low bounds (if range) against
6235 -- the proper index type of the array.
6238 Index
:= First
(Choices
(Assoc
));
6239 Index_Typ
:= First_Index
(P_Type
);
6241 if Present
(Next_Index
(Index_Typ
)) then
6242 Error_Msg_N
("too few subscripts in array reference", Assoc
);
6245 while Present
(Index
) loop
6247 -- The use of others is illegal (SPARK RM 4.4.1(12))
6249 if Nkind
(Index
) = N_Others_Choice
then
6251 ("others choice not allowed in attribute %", Index
);
6253 -- The index denotes a range of elements
6255 elsif Nkind
(Index
) = N_Range
then
6256 Low
:= Low_Bound
(Index
);
6257 High
:= High_Bound
(Index
);
6259 Analyze_And_Resolve
(Low
, Etype
(Index_Typ
));
6260 Analyze_And_Resolve
(High
, Etype
(Index_Typ
));
6262 -- Add a range check to ensure that the bounds of the
6263 -- range are within the index type when this cannot be
6264 -- determined statically.
6266 if not Is_OK_Static_Expression
(Low
) then
6267 Set_Do_Range_Check
(Low
);
6270 if not Is_OK_Static_Expression
(High
) then
6271 Set_Do_Range_Check
(High
);
6274 -- Otherwise the index denotes a single element
6277 Analyze_And_Resolve
(Index
, Etype
(Index_Typ
));
6279 -- Add a range check to ensure that the index is within
6280 -- the index type when it is not possible to determine
6283 if not Is_OK_Static_Expression
(Index
) then
6284 Set_Do_Range_Check
(Index
);
6291 end Analyze_Array_Component_Update
;
6293 -------------------------------------
6294 -- Analyze_Record_Component_Update --
6295 -------------------------------------
6297 procedure Analyze_Record_Component_Update
(Comp
: Node_Id
) is
6298 Comp_Name
: constant Name_Id
:= Chars
(Comp
);
6299 Base_Typ
: Entity_Id
;
6300 Comp_Or_Discr
: Entity_Id
;
6303 -- Find the discriminant or component whose name corresponds to
6304 -- Comp. A simple character comparison is sufficient because all
6305 -- visible names within a record type are unique.
6307 Comp_Or_Discr
:= First_Entity
(P_Type
);
6308 while Present
(Comp_Or_Discr
) loop
6309 if Chars
(Comp_Or_Discr
) = Comp_Name
then
6311 -- Decorate the component reference by setting its entity
6312 -- and type for resolution purposes.
6314 Set_Entity
(Comp
, Comp_Or_Discr
);
6315 Set_Etype
(Comp
, Etype
(Comp_Or_Discr
));
6319 Comp_Or_Discr
:= Next_Entity
(Comp_Or_Discr
);
6322 -- Diagnose an illegal reference
6324 if Present
(Comp_Or_Discr
) then
6325 if Ekind
(Comp_Or_Discr
) = E_Discriminant
then
6327 ("attribute % may not modify record discriminants", Comp
);
6329 else pragma Assert
(Ekind
(Comp_Or_Discr
) = E_Component
);
6330 if Contains
(Comps
, Comp_Or_Discr
) then
6331 Error_Msg_N
("component & already updated", Comp
);
6333 -- Mark this component as processed
6336 Append_New_Elmt
(Comp_Or_Discr
, Comps
);
6340 -- The update aggregate mentions an entity that does not belong to
6344 Error_Msg_N
("& is not a component of aggregate subtype", Comp
);
6347 -- Verify the consistency of types when the current component is
6348 -- part of a miltiple component update.
6350 -- Comp_1, ..., Comp_N => <value>
6352 if Present
(Etype
(Comp
)) then
6353 Base_Typ
:= Base_Type
(Etype
(Comp
));
6355 -- Save the type of the first component reference as the
6356 -- remaning references (if any) must resolve to this type.
6358 if No
(Common_Typ
) then
6359 Common_Typ
:= Base_Typ
;
6361 elsif Base_Typ
/= Common_Typ
then
6363 ("components in choice list must have same type", Comp
);
6366 end Analyze_Record_Component_Update
;
6373 -- Start of processing for Update
6378 if not Is_Object_Reference
(P
) then
6379 Error_Attr_P
("prefix of attribute % must denote an object");
6381 elsif not Is_Array_Type
(P_Type
)
6382 and then not Is_Record_Type
(P_Type
)
6384 Error_Attr_P
("prefix of attribute % must be a record or array");
6386 elsif Is_Limited_View
(P_Type
) then
6387 Error_Attr
("prefix of attribute % cannot be limited", N
);
6389 elsif Nkind
(E1
) /= N_Aggregate
then
6390 Error_Attr
("attribute % requires component association list", N
);
6393 -- Inspect the update aggregate, looking at all the associations and
6394 -- choices. Perform the following checks:
6396 -- 1) Legality of "others" in all cases
6397 -- 2) Legality of <>
6398 -- 3) Component legality for arrays
6399 -- 4) Component legality for records
6401 -- The remaining checks are performed on the expanded attribute
6403 Assoc
:= First
(Component_Associations
(E1
));
6404 while Present
(Assoc
) loop
6406 -- The use of <> is illegal (SPARK RM 4.4.1(1))
6408 if Box_Present
(Assoc
) then
6410 ("default initialization not allowed in attribute %", Assoc
);
6412 -- Otherwise process the association
6415 Analyze
(Expression
(Assoc
));
6417 if Is_Array_Type
(P_Type
) then
6418 Analyze_Array_Component_Update
(Assoc
);
6420 elsif Is_Record_Type
(P_Type
) then
6422 -- Reset the common type used in a multiple component update
6423 -- as we are processing the contents of a new association.
6425 Common_Typ
:= Empty
;
6427 Comp
:= First
(Choices
(Assoc
));
6428 while Present
(Comp
) loop
6429 if Nkind
(Comp
) = N_Identifier
then
6430 Analyze_Record_Component_Update
(Comp
);
6432 -- The use of others is illegal (SPARK RM 4.4.1(5))
6434 elsif Nkind
(Comp
) = N_Others_Choice
then
6436 ("others choice not allowed in attribute %", Comp
);
6438 -- The name of a record component cannot appear in any
6443 ("name should be identifier or OTHERS", Comp
);
6454 -- The type of attribute 'Update is that of the prefix
6456 Set_Etype
(N
, P_Type
);
6458 Sem_Warn
.Warn_On_Suspicious_Update
(N
);
6465 when Attribute_Val
=> Val
: declare
6468 Check_Discrete_Type
;
6470 if Is_Boolean_Type
(P_Type
) then
6471 Error_Msg_Name_1
:= Aname
;
6472 Error_Msg_Name_2
:= Chars
(P_Type
);
6473 Check_SPARK_05_Restriction
6474 ("attribute% is not allowed for type%", P
);
6477 Resolve
(E1
, Any_Integer
);
6478 Set_Etype
(N
, P_Base_Type
);
6480 -- Note, we need a range check in general, but we wait for the
6481 -- Resolve call to do this, since we want to let Eval_Attribute
6482 -- have a chance to find an static illegality first.
6489 when Attribute_Valid
=>
6492 -- Ignore check for object if we have a 'Valid reference generated
6493 -- by the expanded code, since in some cases valid checks can occur
6494 -- on items that are names, but are not objects (e.g. attributes).
6496 if Comes_From_Source
(N
) then
6497 Check_Object_Reference
(P
);
6500 if not Is_Scalar_Type
(P_Type
) then
6501 Error_Attr_P
("object for % attribute must be of scalar type");
6504 -- If the attribute appears within the subtype's own predicate
6505 -- function, then issue a warning that this will cause infinite
6509 Pred_Func
: constant Entity_Id
:= Predicate_Function
(P_Type
);
6512 if Present
(Pred_Func
) and then Current_Scope
= Pred_Func
then
6514 ("attribute Valid requires a predicate check??", N
);
6515 Error_Msg_N
("\and will result in infinite recursion??", N
);
6519 Set_Etype
(N
, Standard_Boolean
);
6525 when Attribute_Valid_Scalars
=>
6527 Check_Object_Reference
(P
);
6528 Set_Etype
(N
, Standard_Boolean
);
6530 -- Following checks are only for source types
6532 if Comes_From_Source
(N
) then
6533 if not Scalar_Part_Present
(P_Type
) then
6535 ("??attribute % always True, no scalars to check");
6538 -- Not allowed for unchecked union type
6540 if Has_Unchecked_Union
(P_Type
) then
6542 ("attribute % not allowed for Unchecked_Union type");
6550 when Attribute_Value
=> Value
:
6552 Check_SPARK_05_Restriction_On_Attribute
;
6556 -- Case of enumeration type
6558 -- When an enumeration type appears in an attribute reference, all
6559 -- literals of the type are marked as referenced. This must only be
6560 -- done if the attribute reference appears in the current source.
6561 -- Otherwise the information on references may differ between a
6562 -- normal compilation and one that performs inlining.
6564 if Is_Enumeration_Type
(P_Type
)
6565 and then In_Extended_Main_Code_Unit
(N
)
6567 Check_Restriction
(No_Enumeration_Maps
, N
);
6569 -- Mark all enumeration literals as referenced, since the use of
6570 -- the Value attribute can implicitly reference any of the
6571 -- literals of the enumeration base type.
6574 Ent
: Entity_Id
:= First_Literal
(P_Base_Type
);
6576 while Present
(Ent
) loop
6577 Set_Referenced
(Ent
);
6583 -- Set Etype before resolving expression because expansion of
6584 -- expression may require enclosing type. Note that the type
6585 -- returned by 'Value is the base type of the prefix type.
6587 Set_Etype
(N
, P_Base_Type
);
6588 Validate_Non_Static_Attribute_Function_Call
;
6590 -- Check restriction No_Fixed_IO
6592 if Restriction_Check_Required
(No_Fixed_IO
)
6593 and then Is_Fixed_Point_Type
(P_Type
)
6595 Check_Restriction
(No_Fixed_IO
, P
);
6603 when Attribute_Value_Size
=>
6606 Check_Not_Incomplete_Type
;
6607 Set_Etype
(N
, Universal_Integer
);
6613 when Attribute_Version
=>
6616 Set_Etype
(N
, RTE
(RE_Version_String
));
6622 when Attribute_Wchar_T_Size
=>
6623 Standard_Attribute
(Interfaces_Wchar_T_Size
);
6629 when Attribute_Wide_Image
=> Wide_Image
:
6631 Check_SPARK_05_Restriction_On_Attribute
;
6633 Set_Etype
(N
, Standard_Wide_String
);
6635 Resolve
(E1
, P_Base_Type
);
6636 Validate_Non_Static_Attribute_Function_Call
;
6638 -- Check restriction No_Fixed_IO
6640 if Restriction_Check_Required
(No_Fixed_IO
)
6641 and then Is_Fixed_Point_Type
(P_Type
)
6643 Check_Restriction
(No_Fixed_IO
, P
);
6647 ---------------------
6648 -- Wide_Wide_Image --
6649 ---------------------
6651 when Attribute_Wide_Wide_Image
=> Wide_Wide_Image
:
6654 Set_Etype
(N
, Standard_Wide_Wide_String
);
6656 Resolve
(E1
, P_Base_Type
);
6657 Validate_Non_Static_Attribute_Function_Call
;
6659 -- Check restriction No_Fixed_IO
6661 if Restriction_Check_Required
(No_Fixed_IO
)
6662 and then Is_Fixed_Point_Type
(P_Type
)
6664 Check_Restriction
(No_Fixed_IO
, P
);
6666 end Wide_Wide_Image
;
6672 when Attribute_Wide_Value
=> Wide_Value
:
6674 Check_SPARK_05_Restriction_On_Attribute
;
6678 -- Set Etype before resolving expression because expansion
6679 -- of expression may require enclosing type.
6681 Set_Etype
(N
, P_Type
);
6682 Validate_Non_Static_Attribute_Function_Call
;
6684 -- Check restriction No_Fixed_IO
6686 if Restriction_Check_Required
(No_Fixed_IO
)
6687 and then Is_Fixed_Point_Type
(P_Type
)
6689 Check_Restriction
(No_Fixed_IO
, P
);
6693 ---------------------
6694 -- Wide_Wide_Value --
6695 ---------------------
6697 when Attribute_Wide_Wide_Value
=> Wide_Wide_Value
:
6702 -- Set Etype before resolving expression because expansion
6703 -- of expression may require enclosing type.
6705 Set_Etype
(N
, P_Type
);
6706 Validate_Non_Static_Attribute_Function_Call
;
6708 -- Check restriction No_Fixed_IO
6710 if Restriction_Check_Required
(No_Fixed_IO
)
6711 and then Is_Fixed_Point_Type
(P_Type
)
6713 Check_Restriction
(No_Fixed_IO
, P
);
6715 end Wide_Wide_Value
;
6717 ---------------------
6718 -- Wide_Wide_Width --
6719 ---------------------
6721 when Attribute_Wide_Wide_Width
=>
6724 Set_Etype
(N
, Universal_Integer
);
6730 when Attribute_Wide_Width
=>
6731 Check_SPARK_05_Restriction_On_Attribute
;
6734 Set_Etype
(N
, Universal_Integer
);
6740 when Attribute_Width
=>
6741 Check_SPARK_05_Restriction_On_Attribute
;
6744 Set_Etype
(N
, Universal_Integer
);
6750 when Attribute_Word_Size
=>
6751 Standard_Attribute
(System_Word_Size
);
6757 when Attribute_Write
=>
6759 Check_Stream_Attribute
(TSS_Stream_Write
);
6760 Set_Etype
(N
, Standard_Void_Type
);
6761 Resolve
(N
, Standard_Void_Type
);
6765 -- All errors raise Bad_Attribute, so that we get out before any further
6766 -- damage occurs when an error is detected (for example, if we check for
6767 -- one attribute expression, and the check succeeds, we want to be able
6768 -- to proceed securely assuming that an expression is in fact present.
6770 -- Note: we set the attribute analyzed in this case to prevent any
6771 -- attempt at reanalysis which could generate spurious error msgs.
6774 when Bad_Attribute
=>
6776 Set_Etype
(N
, Any_Type
);
6778 end Analyze_Attribute
;
6780 --------------------
6781 -- Eval_Attribute --
6782 --------------------
6784 procedure Eval_Attribute
(N
: Node_Id
) is
6785 Loc
: constant Source_Ptr
:= Sloc
(N
);
6786 Aname
: constant Name_Id
:= Attribute_Name
(N
);
6787 Id
: constant Attribute_Id
:= Get_Attribute_Id
(Aname
);
6788 P
: constant Node_Id
:= Prefix
(N
);
6790 C_Type
: constant Entity_Id
:= Etype
(N
);
6791 -- The type imposed by the context
6794 -- First expression, or Empty if none
6797 -- Second expression, or Empty if none
6799 P_Entity
: Entity_Id
;
6800 -- Entity denoted by prefix
6803 -- The type of the prefix
6805 P_Base_Type
: Entity_Id
;
6806 -- The base type of the prefix type
6808 P_Root_Type
: Entity_Id
;
6809 -- The root type of the prefix type
6812 -- True if the result is Static. This is set by the general processing
6813 -- to true if the prefix is static, and all expressions are static. It
6814 -- can be reset as processing continues for particular attributes. This
6815 -- flag can still be True if the reference raises a constraint error.
6816 -- Is_Static_Expression (N) is set to follow this value as it is set
6817 -- and we could always reference this, but it is convenient to have a
6818 -- simple short name to use, since it is frequently referenced.
6820 Lo_Bound
, Hi_Bound
: Node_Id
;
6821 -- Expressions for low and high bounds of type or array index referenced
6822 -- by First, Last, or Length attribute for array, set by Set_Bounds.
6825 -- Constraint error node used if we have an attribute reference has
6826 -- an argument that raises a constraint error. In this case we replace
6827 -- the attribute with a raise constraint_error node. This is important
6828 -- processing, since otherwise gigi might see an attribute which it is
6829 -- unprepared to deal with.
6831 procedure Check_Concurrent_Discriminant
(Bound
: Node_Id
);
6832 -- If Bound is a reference to a discriminant of a task or protected type
6833 -- occurring within the object's body, rewrite attribute reference into
6834 -- a reference to the corresponding discriminal. Use for the expansion
6835 -- of checks against bounds of entry family index subtypes.
6837 procedure Check_Expressions
;
6838 -- In case where the attribute is not foldable, the expressions, if
6839 -- any, of the attribute, are in a non-static context. This procedure
6840 -- performs the required additional checks.
6842 function Compile_Time_Known_Bounds
(Typ
: Entity_Id
) return Boolean;
6843 -- Determines if the given type has compile time known bounds. Note
6844 -- that we enter the case statement even in cases where the prefix
6845 -- type does NOT have known bounds, so it is important to guard any
6846 -- attempt to evaluate both bounds with a call to this function.
6848 procedure Compile_Time_Known_Attribute
(N
: Node_Id
; Val
: Uint
);
6849 -- This procedure is called when the attribute N has a non-static
6850 -- but compile time known value given by Val. It includes the
6851 -- necessary checks for out of range values.
6853 function Fore_Value
return Nat
;
6854 -- Computes the Fore value for the current attribute prefix, which is
6855 -- known to be a static fixed-point type. Used by Fore and Width.
6857 function Mantissa
return Uint
;
6858 -- Returns the Mantissa value for the prefix type
6860 procedure Set_Bounds
;
6861 -- Used for First, Last and Length attributes applied to an array or
6862 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
6863 -- and high bound expressions for the index referenced by the attribute
6864 -- designator (i.e. the first index if no expression is present, and the
6865 -- N'th index if the value N is present as an expression). Also used for
6866 -- First and Last of scalar types and for First_Valid and Last_Valid.
6867 -- Static is reset to False if the type or index type is not statically
6870 function Statically_Denotes_Entity
(N
: Node_Id
) return Boolean;
6871 -- Verify that the prefix of a potentially static array attribute
6872 -- satisfies the conditions of 4.9 (14).
6874 -----------------------------------
6875 -- Check_Concurrent_Discriminant --
6876 -----------------------------------
6878 procedure Check_Concurrent_Discriminant
(Bound
: Node_Id
) is
6880 -- The concurrent (task or protected) type
6883 if Nkind
(Bound
) = N_Identifier
6884 and then Ekind
(Entity
(Bound
)) = E_Discriminant
6885 and then Is_Concurrent_Record_Type
(Scope
(Entity
(Bound
)))
6887 Tsk
:= Corresponding_Concurrent_Type
(Scope
(Entity
(Bound
)));
6889 if In_Open_Scopes
(Tsk
) and then Has_Completion
(Tsk
) then
6891 -- Find discriminant of original concurrent type, and use
6892 -- its current discriminal, which is the renaming within
6893 -- the task/protected body.
6897 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
));
6900 end Check_Concurrent_Discriminant
;
6902 -----------------------
6903 -- Check_Expressions --
6904 -----------------------
6906 procedure Check_Expressions
is
6910 while Present
(E
) loop
6911 Check_Non_Static_Context
(E
);
6914 end Check_Expressions
;
6916 ----------------------------------
6917 -- Compile_Time_Known_Attribute --
6918 ----------------------------------
6920 procedure Compile_Time_Known_Attribute
(N
: Node_Id
; Val
: Uint
) is
6921 T
: constant Entity_Id
:= Etype
(N
);
6924 Fold_Uint
(N
, Val
, False);
6926 -- Check that result is in bounds of the type if it is static
6928 if Is_In_Range
(N
, T
, Assume_Valid
=> False) then
6931 elsif Is_Out_Of_Range
(N
, T
) then
6932 Apply_Compile_Time_Constraint_Error
6933 (N
, "value not in range of}??", CE_Range_Check_Failed
);
6935 elsif not Range_Checks_Suppressed
(T
) then
6936 Enable_Range_Check
(N
);
6939 Set_Do_Range_Check
(N
, False);
6941 end Compile_Time_Known_Attribute
;
6943 -------------------------------
6944 -- Compile_Time_Known_Bounds --
6945 -------------------------------
6947 function Compile_Time_Known_Bounds
(Typ
: Entity_Id
) return Boolean is
6950 Compile_Time_Known_Value
(Type_Low_Bound
(Typ
))
6952 Compile_Time_Known_Value
(Type_High_Bound
(Typ
));
6953 end Compile_Time_Known_Bounds
;
6959 -- Note that the Fore calculation is based on the actual values
6960 -- of the bounds, and does not take into account possible rounding.
6962 function Fore_Value
return Nat
is
6963 Lo
: constant Uint
:= Expr_Value
(Type_Low_Bound
(P_Type
));
6964 Hi
: constant Uint
:= Expr_Value
(Type_High_Bound
(P_Type
));
6965 Small
: constant Ureal
:= Small_Value
(P_Type
);
6966 Lo_Real
: constant Ureal
:= Lo
* Small
;
6967 Hi_Real
: constant Ureal
:= Hi
* Small
;
6972 -- Bounds are given in terms of small units, so first compute
6973 -- proper values as reals.
6975 T
:= UR_Max
(abs Lo_Real
, abs Hi_Real
);
6978 -- Loop to compute proper value if more than one digit required
6980 while T
>= Ureal_10
loop
6992 -- Table of mantissa values accessed by function Computed using
6995 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
6997 -- where D is T'Digits (RM83 3.5.7)
6999 Mantissa_Value
: constant array (Nat
range 1 .. 40) of Nat
:= (
7041 function Mantissa
return Uint
is
7044 UI_From_Int
(Mantissa_Value
(UI_To_Int
(Digits_Value
(P_Type
))));
7051 procedure Set_Bounds
is
7057 -- For a string literal subtype, we have to construct the bounds.
7058 -- Valid Ada code never applies attributes to string literals, but
7059 -- it is convenient to allow the expander to generate attribute
7060 -- references of this type (e.g. First and Last applied to a string
7063 -- Note that the whole point of the E_String_Literal_Subtype is to
7064 -- avoid this construction of bounds, but the cases in which we
7065 -- have to materialize them are rare enough that we don't worry.
7067 -- The low bound is simply the low bound of the base type. The
7068 -- high bound is computed from the length of the string and this
7071 if Ekind
(P_Type
) = E_String_Literal_Subtype
then
7072 Ityp
:= Etype
(First_Index
(Base_Type
(P_Type
)));
7073 Lo_Bound
:= Type_Low_Bound
(Ityp
);
7076 Make_Integer_Literal
(Sloc
(P
),
7078 Expr_Value
(Lo_Bound
) + String_Literal_Length
(P_Type
) - 1);
7080 Set_Parent
(Hi_Bound
, P
);
7081 Analyze_And_Resolve
(Hi_Bound
, Etype
(Lo_Bound
));
7084 -- For non-array case, just get bounds of scalar type
7086 elsif Is_Scalar_Type
(P_Type
) then
7089 -- For a fixed-point type, we must freeze to get the attributes
7090 -- of the fixed-point type set now so we can reference them.
7092 if Is_Fixed_Point_Type
(P_Type
)
7093 and then not Is_Frozen
(Base_Type
(P_Type
))
7094 and then Compile_Time_Known_Value
(Type_Low_Bound
(P_Type
))
7095 and then Compile_Time_Known_Value
(Type_High_Bound
(P_Type
))
7097 Freeze_Fixed_Point_Type
(Base_Type
(P_Type
));
7100 -- For array case, get type of proper index
7106 Ndim
:= UI_To_Int
(Expr_Value
(E1
));
7109 Indx
:= First_Index
(P_Type
);
7110 for J
in 1 .. Ndim
- 1 loop
7114 -- If no index type, get out (some other error occurred, and
7115 -- we don't have enough information to complete the job).
7123 Ityp
:= Etype
(Indx
);
7126 -- A discrete range in an index constraint is allowed to be a
7127 -- subtype indication. This is syntactically a pain, but should
7128 -- not propagate to the entity for the corresponding index subtype.
7129 -- After checking that the subtype indication is legal, the range
7130 -- of the subtype indication should be transfered to the entity.
7131 -- The attributes for the bounds should remain the simple retrievals
7132 -- that they are now.
7134 Lo_Bound
:= Type_Low_Bound
(Ityp
);
7135 Hi_Bound
:= Type_High_Bound
(Ityp
);
7137 -- If subtype is non-static, result is definitely non-static
7139 if not Is_Static_Subtype
(Ityp
) then
7141 Set_Is_Static_Expression
(N
, False);
7143 -- Subtype is static, does it raise CE?
7145 elsif not Is_OK_Static_Subtype
(Ityp
) then
7146 Set_Raises_Constraint_Error
(N
);
7150 -------------------------------
7151 -- Statically_Denotes_Entity --
7152 -------------------------------
7154 function Statically_Denotes_Entity
(N
: Node_Id
) return Boolean is
7158 if not Is_Entity_Name
(N
) then
7165 Nkind
(Parent
(E
)) /= N_Object_Renaming_Declaration
7166 or else Statically_Denotes_Entity
(Renamed_Object
(E
));
7167 end Statically_Denotes_Entity
;
7169 -- Start of processing for Eval_Attribute
7172 -- Initialize result as non-static, will be reset if appropriate
7174 Set_Is_Static_Expression
(N
, False);
7177 -- Acquire first two expressions (at the moment, no attributes take more
7178 -- than two expressions in any case).
7180 if Present
(Expressions
(N
)) then
7181 E1
:= First
(Expressions
(N
));
7188 -- Special processing for Enabled attribute. This attribute has a very
7189 -- special prefix, and the easiest way to avoid lots of special checks
7190 -- to protect this special prefix from causing trouble is to deal with
7191 -- this attribute immediately and be done with it.
7193 if Id
= Attribute_Enabled
then
7195 -- We skip evaluation if the expander is not active. This is not just
7196 -- an optimization. It is of key importance that we not rewrite the
7197 -- attribute in a generic template, since we want to pick up the
7198 -- setting of the check in the instance, and testing expander active
7199 -- is as easy way of doing this as any.
7201 if Expander_Active
then
7203 C
: constant Check_Id
:= Get_Check_Id
(Chars
(P
));
7208 if C
in Predefined_Check_Id
then
7209 R
:= Scope_Suppress
.Suppress
(C
);
7211 R
:= Is_Check_Suppressed
(Empty
, C
);
7215 R
:= Is_Check_Suppressed
(Entity
(E1
), C
);
7218 Rewrite
(N
, New_Occurrence_Of
(Boolean_Literals
(not R
), Loc
));
7225 -- Attribute 'Img applied to a static enumeration value is static, and
7226 -- we will do the folding right here (things get confused if we let this
7227 -- case go through the normal circuitry).
7229 if Attribute_Name
(N
) = Name_Img
7230 and then Is_Entity_Name
(P
)
7231 and then Is_Enumeration_Type
(Etype
(Entity
(P
)))
7232 and then Is_OK_Static_Expression
(P
)
7235 Lit
: constant Entity_Id
:= Expr_Value_E
(P
);
7240 Get_Unqualified_Decoded_Name_String
(Chars
(Lit
));
7241 Set_Casing
(All_Upper_Case
);
7242 Store_String_Chars
(Name_Buffer
(1 .. Name_Len
));
7245 Rewrite
(N
, Make_String_Literal
(Loc
, Strval
=> Str
));
7246 Analyze_And_Resolve
(N
, Standard_String
);
7247 Set_Is_Static_Expression
(N
, True);
7253 -- Special processing for cases where the prefix is an object. For
7254 -- this purpose, a string literal counts as an object (attributes
7255 -- of string literals can only appear in generated code).
7257 if Is_Object_Reference
(P
) or else Nkind
(P
) = N_String_Literal
then
7259 -- For Component_Size, the prefix is an array object, and we apply
7260 -- the attribute to the type of the object. This is allowed for
7261 -- both unconstrained and constrained arrays, since the bounds
7262 -- have no influence on the value of this attribute.
7264 if Id
= Attribute_Component_Size
then
7265 P_Entity
:= Etype
(P
);
7267 -- For First and Last, the prefix is an array object, and we apply
7268 -- the attribute to the type of the array, but we need a constrained
7269 -- type for this, so we use the actual subtype if available.
7271 elsif Id
= Attribute_First
or else
7272 Id
= Attribute_Last
or else
7273 Id
= Attribute_Length
7276 AS
: constant Entity_Id
:= Get_Actual_Subtype_If_Available
(P
);
7279 if Present
(AS
) and then Is_Constrained
(AS
) then
7282 -- If we have an unconstrained type we cannot fold
7290 -- For Size, give size of object if available, otherwise we
7291 -- cannot fold Size.
7293 elsif Id
= Attribute_Size
then
7294 if Is_Entity_Name
(P
)
7295 and then Known_Esize
(Entity
(P
))
7297 Compile_Time_Known_Attribute
(N
, Esize
(Entity
(P
)));
7305 -- For Alignment, give size of object if available, otherwise we
7306 -- cannot fold Alignment.
7308 elsif Id
= Attribute_Alignment
then
7309 if Is_Entity_Name
(P
)
7310 and then Known_Alignment
(Entity
(P
))
7312 Fold_Uint
(N
, Alignment
(Entity
(P
)), Static
);
7320 -- For Lock_Free, we apply the attribute to the type of the object.
7321 -- This is allowed since we have already verified that the type is a
7324 elsif Id
= Attribute_Lock_Free
then
7325 P_Entity
:= Etype
(P
);
7327 -- No other attributes for objects are folded
7334 -- Cases where P is not an object. Cannot do anything if P is not the
7335 -- name of an entity.
7337 elsif not Is_Entity_Name
(P
) then
7341 -- Otherwise get prefix entity
7344 P_Entity
:= Entity
(P
);
7347 -- If we are asked to evaluate an attribute where the prefix is a
7348 -- non-frozen generic actual type whose RM_Size is still set to zero,
7349 -- then abandon the effort.
7351 if Is_Type
(P_Entity
)
7352 and then (not Is_Frozen
(P_Entity
)
7353 and then Is_Generic_Actual_Type
(P_Entity
)
7354 and then RM_Size
(P_Entity
) = 0)
7356 -- However, the attribute Unconstrained_Array must be evaluated,
7357 -- since it is documented to be a static attribute (and can for
7358 -- example appear in a Compile_Time_Warning pragma). The frozen
7359 -- status of the type does not affect its evaluation.
7361 and then Id
/= Attribute_Unconstrained_Array
7366 -- At this stage P_Entity is the entity to which the attribute
7367 -- is to be applied. This is usually simply the entity of the
7368 -- prefix, except in some cases of attributes for objects, where
7369 -- as described above, we apply the attribute to the object type.
7371 -- Here is where we make sure that static attributes are properly
7372 -- marked as such. These are attributes whose prefix is a static
7373 -- scalar subtype, whose result is scalar, and whose arguments, if
7374 -- present, are static scalar expressions. Note that such references
7375 -- are static expressions even if they raise Constraint_Error.
7377 -- For example, Boolean'Pos (1/0 = 0) is a static expression, even
7378 -- though evaluating it raises constraint error. This means that a
7379 -- declaration like:
7381 -- X : constant := (if True then 1 else Boolean'Pos (1/0 = 0));
7383 -- is legal, since here this expression appears in a statically
7384 -- unevaluated position, so it does not actually raise an exception.
7386 if Is_Scalar_Type
(P_Entity
)
7387 and then (not Is_Generic_Type
(P_Entity
))
7388 and then Is_Static_Subtype
(P_Entity
)
7389 and then Is_Scalar_Type
(Etype
(N
))
7392 or else (Is_Static_Expression
(E1
)
7393 and then Is_Scalar_Type
(Etype
(E1
))))
7396 or else (Is_Static_Expression
(E2
)
7397 and then Is_Scalar_Type
(Etype
(E1
))))
7400 Set_Is_Static_Expression
(N
, True);
7403 -- First foldable possibility is a scalar or array type (RM 4.9(7))
7404 -- that is not generic (generic types are eliminated by RM 4.9(25)).
7405 -- Note we allow non-static non-generic types at this stage as further
7408 if Is_Type
(P_Entity
)
7409 and then (Is_Scalar_Type
(P_Entity
) or Is_Array_Type
(P_Entity
))
7410 and then (not Is_Generic_Type
(P_Entity
))
7414 -- Second foldable possibility is an array object (RM 4.9(8))
7416 elsif Ekind_In
(P_Entity
, E_Variable
, E_Constant
)
7417 and then Is_Array_Type
(Etype
(P_Entity
))
7418 and then (not Is_Generic_Type
(Etype
(P_Entity
)))
7420 P_Type
:= Etype
(P_Entity
);
7422 -- If the entity is an array constant with an unconstrained nominal
7423 -- subtype then get the type from the initial value. If the value has
7424 -- been expanded into assignments, there is no expression and the
7425 -- attribute reference remains dynamic.
7427 -- We could do better here and retrieve the type ???
7429 if Ekind
(P_Entity
) = E_Constant
7430 and then not Is_Constrained
(P_Type
)
7432 if No
(Constant_Value
(P_Entity
)) then
7435 P_Type
:= Etype
(Constant_Value
(P_Entity
));
7439 -- Definite must be folded if the prefix is not a generic type, that
7440 -- is to say if we are within an instantiation. Same processing applies
7441 -- to the GNAT attributes Atomic_Always_Lock_Free, Has_Discriminants,
7442 -- Lock_Free, Type_Class, Has_Tagged_Value, and Unconstrained_Array.
7444 elsif (Id
= Attribute_Atomic_Always_Lock_Free
or else
7445 Id
= Attribute_Definite
or else
7446 Id
= Attribute_Has_Access_Values
or else
7447 Id
= Attribute_Has_Discriminants
or else
7448 Id
= Attribute_Has_Tagged_Values
or else
7449 Id
= Attribute_Lock_Free
or else
7450 Id
= Attribute_Type_Class
or else
7451 Id
= Attribute_Unconstrained_Array
or else
7452 Id
= Attribute_Max_Alignment_For_Allocation
)
7453 and then not Is_Generic_Type
(P_Entity
)
7457 -- We can fold 'Size applied to a type if the size is known (as happens
7458 -- for a size from an attribute definition clause). At this stage, this
7459 -- can happen only for types (e.g. record types) for which the size is
7460 -- always non-static. We exclude generic types from consideration (since
7461 -- they have bogus sizes set within templates).
7463 elsif Id
= Attribute_Size
7464 and then Is_Type
(P_Entity
)
7465 and then (not Is_Generic_Type
(P_Entity
))
7466 and then Known_Static_RM_Size
(P_Entity
)
7468 Compile_Time_Known_Attribute
(N
, RM_Size
(P_Entity
));
7471 -- We can fold 'Alignment applied to a type if the alignment is known
7472 -- (as happens for an alignment from an attribute definition clause).
7473 -- At this stage, this can happen only for types (e.g. record types) for
7474 -- which the size is always non-static. We exclude generic types from
7475 -- consideration (since they have bogus sizes set within templates).
7477 elsif Id
= Attribute_Alignment
7478 and then Is_Type
(P_Entity
)
7479 and then (not Is_Generic_Type
(P_Entity
))
7480 and then Known_Alignment
(P_Entity
)
7482 Compile_Time_Known_Attribute
(N
, Alignment
(P_Entity
));
7485 -- If this is an access attribute that is known to fail accessibility
7486 -- check, rewrite accordingly.
7488 elsif Attribute_Name
(N
) = Name_Access
7489 and then Raises_Constraint_Error
(N
)
7492 Make_Raise_Program_Error
(Loc
,
7493 Reason
=> PE_Accessibility_Check_Failed
));
7494 Set_Etype
(N
, C_Type
);
7497 -- No other cases are foldable (they certainly aren't static, and at
7498 -- the moment we don't try to fold any cases other than the ones above).
7505 -- If either attribute or the prefix is Any_Type, then propagate
7506 -- Any_Type to the result and don't do anything else at all.
7508 if P_Type
= Any_Type
7509 or else (Present
(E1
) and then Etype
(E1
) = Any_Type
)
7510 or else (Present
(E2
) and then Etype
(E2
) = Any_Type
)
7512 Set_Etype
(N
, Any_Type
);
7516 -- Scalar subtype case. We have not yet enforced the static requirement
7517 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
7518 -- of non-static attribute references (e.g. S'Digits for a non-static
7519 -- floating-point type, which we can compute at compile time).
7521 -- Note: this folding of non-static attributes is not simply a case of
7522 -- optimization. For many of the attributes affected, Gigi cannot handle
7523 -- the attribute and depends on the front end having folded them away.
7525 -- Note: although we don't require staticness at this stage, we do set
7526 -- the Static variable to record the staticness, for easy reference by
7527 -- those attributes where it matters (e.g. Succ and Pred), and also to
7528 -- be used to ensure that non-static folded things are not marked as
7529 -- being static (a check that is done right at the end).
7531 P_Root_Type
:= Root_Type
(P_Type
);
7532 P_Base_Type
:= Base_Type
(P_Type
);
7534 -- If the root type or base type is generic, then we cannot fold. This
7535 -- test is needed because subtypes of generic types are not always
7536 -- marked as being generic themselves (which seems odd???)
7538 if Is_Generic_Type
(P_Root_Type
)
7539 or else Is_Generic_Type
(P_Base_Type
)
7544 if Is_Scalar_Type
(P_Type
) then
7545 if not Is_Static_Subtype
(P_Type
) then
7547 Set_Is_Static_Expression
(N
, False);
7548 elsif not Is_OK_Static_Subtype
(P_Type
) then
7549 Set_Raises_Constraint_Error
(N
);
7552 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
7553 -- since we can't do anything with unconstrained arrays. In addition,
7554 -- only the First, Last and Length attributes are possibly static.
7556 -- Atomic_Always_Lock_Free, Definite, Has_Access_Values,
7557 -- Has_Discriminants, Has_Tagged_Values, Lock_Free, Type_Class, and
7558 -- Unconstrained_Array are again exceptions, because they apply as well
7559 -- to unconstrained types.
7561 -- In addition Component_Size is an exception since it is possibly
7562 -- foldable, even though it is never static, and it does apply to
7563 -- unconstrained arrays. Furthermore, it is essential to fold this
7564 -- in the packed case, since otherwise the value will be incorrect.
7566 elsif Id
= Attribute_Atomic_Always_Lock_Free
or else
7567 Id
= Attribute_Definite
or else
7568 Id
= Attribute_Has_Access_Values
or else
7569 Id
= Attribute_Has_Discriminants
or else
7570 Id
= Attribute_Has_Tagged_Values
or else
7571 Id
= Attribute_Lock_Free
or else
7572 Id
= Attribute_Type_Class
or else
7573 Id
= Attribute_Unconstrained_Array
or else
7574 Id
= Attribute_Component_Size
7577 Set_Is_Static_Expression
(N
, False);
7579 elsif Id
/= Attribute_Max_Alignment_For_Allocation
then
7580 if not Is_Constrained
(P_Type
)
7581 or else (Id
/= Attribute_First
and then
7582 Id
/= Attribute_Last
and then
7583 Id
/= Attribute_Length
)
7589 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
7590 -- scalar case, we hold off on enforcing staticness, since there are
7591 -- cases which we can fold at compile time even though they are not
7592 -- static (e.g. 'Length applied to a static index, even though other
7593 -- non-static indexes make the array type non-static). This is only
7594 -- an optimization, but it falls out essentially free, so why not.
7595 -- Again we compute the variable Static for easy reference later
7596 -- (note that no array attributes are static in Ada 83).
7598 -- We also need to set Static properly for subsequent legality checks
7599 -- which might otherwise accept non-static constants in contexts
7600 -- where they are not legal.
7603 Ada_Version
>= Ada_95
and then Statically_Denotes_Entity
(P
);
7604 Set_Is_Static_Expression
(N
, Static
);
7610 Nod
:= First_Index
(P_Type
);
7612 -- The expression is static if the array type is constrained
7613 -- by given bounds, and not by an initial expression. Constant
7614 -- strings are static in any case.
7616 if Root_Type
(P_Type
) /= Standard_String
then
7618 Static
and then not Is_Constr_Subt_For_U_Nominal
(P_Type
);
7619 Set_Is_Static_Expression
(N
, Static
);
7622 while Present
(Nod
) loop
7623 if not Is_Static_Subtype
(Etype
(Nod
)) then
7625 Set_Is_Static_Expression
(N
, False);
7627 elsif not Is_OK_Static_Subtype
(Etype
(Nod
)) then
7628 Set_Raises_Constraint_Error
(N
);
7630 Set_Is_Static_Expression
(N
, False);
7633 -- If however the index type is generic, or derived from
7634 -- one, attributes cannot be folded.
7636 if Is_Generic_Type
(Root_Type
(Etype
(Nod
)))
7637 and then Id
/= Attribute_Component_Size
7647 -- Check any expressions that are present. Note that these expressions,
7648 -- depending on the particular attribute type, are either part of the
7649 -- attribute designator, or they are arguments in a case where the
7650 -- attribute reference returns a function. In the latter case, the
7651 -- rule in (RM 4.9(22)) applies and in particular requires the type
7652 -- of the expressions to be scalar in order for the attribute to be
7653 -- considered to be static.
7661 while Present
(E
) loop
7663 -- If expression is not static, then the attribute reference
7664 -- result certainly cannot be static.
7666 if not Is_Static_Expression
(E
) then
7668 Set_Is_Static_Expression
(N
, False);
7671 if Raises_Constraint_Error
(E
) then
7672 Set_Raises_Constraint_Error
(N
);
7675 -- If the result is not known at compile time, or is not of
7676 -- a scalar type, then the result is definitely not static,
7677 -- so we can quit now.
7679 if not Compile_Time_Known_Value
(E
)
7680 or else not Is_Scalar_Type
(Etype
(E
))
7682 -- An odd special case, if this is a Pos attribute, this
7683 -- is where we need to apply a range check since it does
7684 -- not get done anywhere else.
7686 if Id
= Attribute_Pos
then
7687 if Is_Integer_Type
(Etype
(E
)) then
7688 Apply_Range_Check
(E
, Etype
(N
));
7695 -- If the expression raises a constraint error, then so does
7696 -- the attribute reference. We keep going in this case because
7697 -- we are still interested in whether the attribute reference
7698 -- is static even if it is not static.
7700 elsif Raises_Constraint_Error
(E
) then
7701 Set_Raises_Constraint_Error
(N
);
7707 if Raises_Constraint_Error
(Prefix
(N
)) then
7708 Set_Is_Static_Expression
(N
, False);
7713 -- Deal with the case of a static attribute reference that raises
7714 -- constraint error. The Raises_Constraint_Error flag will already
7715 -- have been set, and the Static flag shows whether the attribute
7716 -- reference is static. In any case we certainly can't fold such an
7717 -- attribute reference.
7719 -- Note that the rewriting of the attribute node with the constraint
7720 -- error node is essential in this case, because otherwise Gigi might
7721 -- blow up on one of the attributes it never expects to see.
7723 -- The constraint_error node must have the type imposed by the context,
7724 -- to avoid spurious errors in the enclosing expression.
7726 if Raises_Constraint_Error
(N
) then
7728 Make_Raise_Constraint_Error
(Sloc
(N
),
7729 Reason
=> CE_Range_Check_Failed
);
7730 Set_Etype
(CE_Node
, Etype
(N
));
7731 Set_Raises_Constraint_Error
(CE_Node
);
7733 Rewrite
(N
, Relocate_Node
(CE_Node
));
7734 Set_Raises_Constraint_Error
(N
, True);
7738 -- At this point we have a potentially foldable attribute reference.
7739 -- If Static is set, then the attribute reference definitely obeys
7740 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
7741 -- folded. If Static is not set, then the attribute may or may not
7742 -- be foldable, and the individual attribute processing routines
7743 -- test Static as required in cases where it makes a difference.
7745 -- In the case where Static is not set, we do know that all the
7746 -- expressions present are at least known at compile time (we assumed
7747 -- above that if this was not the case, then there was no hope of static
7748 -- evaluation). However, we did not require that the bounds of the
7749 -- prefix type be compile time known, let alone static). That's because
7750 -- there are many attributes that can be computed at compile time on
7751 -- non-static subtypes, even though such references are not static
7754 -- For VAX float, the root type is an IEEE type. So make sure to use the
7755 -- base type instead of the root-type for floating point attributes.
7759 -- Attributes related to Ada 2012 iterators (placeholder ???)
7761 when Attribute_Constant_Indexing |
7762 Attribute_Default_Iterator |
7763 Attribute_Implicit_Dereference |
7764 Attribute_Iterator_Element |
7765 Attribute_Iterable |
7766 Attribute_Variable_Indexing
=> null;
7768 -- Internal attributes used to deal with Ada 2012 delayed aspects.
7769 -- These were already rejected by the parser. Thus they shouldn't
7772 when Internal_Attribute_Id
=>
7773 raise Program_Error
;
7779 when Attribute_Adjacent
=>
7783 (P_Base_Type
, Expr_Value_R
(E1
), Expr_Value_R
(E2
)),
7790 when Attribute_Aft
=>
7791 Fold_Uint
(N
, Aft_Value
(P_Type
), Static
);
7797 when Attribute_Alignment
=> Alignment_Block
: declare
7798 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
7801 -- Fold if alignment is set and not otherwise
7803 if Known_Alignment
(P_TypeA
) then
7804 Fold_Uint
(N
, Alignment
(P_TypeA
), Static
);
7806 end Alignment_Block
;
7808 -----------------------------
7809 -- Atomic_Always_Lock_Free --
7810 -----------------------------
7812 -- Atomic_Always_Lock_Free attribute is a Boolean, thus no need to fold
7815 when Attribute_Atomic_Always_Lock_Free
=> Atomic_Always_Lock_Free
:
7817 V
: constant Entity_Id
:=
7819 (Support_Atomic_Primitives_On_Target
7820 and then Support_Atomic_Primitives
(P_Type
));
7823 Rewrite
(N
, New_Occurrence_Of
(V
, Loc
));
7825 -- Analyze and resolve as boolean. Note that this attribute is a
7826 -- static attribute in GNAT.
7828 Analyze_And_Resolve
(N
, Standard_Boolean
);
7830 Set_Is_Static_Expression
(N
, True);
7831 end Atomic_Always_Lock_Free
;
7837 -- Bit can never be folded
7839 when Attribute_Bit
=>
7846 -- Body_version can never be static
7848 when Attribute_Body_Version
=>
7855 when Attribute_Ceiling
=>
7857 (N
, Eval_Fat
.Ceiling
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
7859 --------------------
7860 -- Component_Size --
7861 --------------------
7863 when Attribute_Component_Size
=>
7864 if Known_Static_Component_Size
(P_Type
) then
7865 Fold_Uint
(N
, Component_Size
(P_Type
), Static
);
7872 when Attribute_Compose
=>
7875 Eval_Fat
.Compose
(P_Base_Type
, Expr_Value_R
(E1
), Expr_Value
(E2
)),
7882 -- Constrained is never folded for now, there may be cases that
7883 -- could be handled at compile time. To be looked at later.
7885 when Attribute_Constrained
=>
7887 -- The expander might fold it and set the static flag accordingly,
7888 -- but with expansion disabled (as in ASIS), it remains as an
7889 -- attribute reference, and this reference is not static.
7891 Set_Is_Static_Expression
(N
, False);
7898 when Attribute_Copy_Sign
=>
7902 (P_Base_Type
, Expr_Value_R
(E1
), Expr_Value_R
(E2
)),
7909 when Attribute_Definite
=>
7910 Rewrite
(N
, New_Occurrence_Of
(
7911 Boolean_Literals
(not Is_Indefinite_Subtype
(P_Entity
)), Loc
));
7912 Analyze_And_Resolve
(N
, Standard_Boolean
);
7918 when Attribute_Delta
=>
7919 Fold_Ureal
(N
, Delta_Value
(P_Type
), True);
7925 when Attribute_Denorm
=>
7927 (N
, UI_From_Int
(Boolean'Pos (Has_Denormals
(P_Type
))), Static
);
7929 ---------------------
7930 -- Descriptor_Size --
7931 ---------------------
7933 when Attribute_Descriptor_Size
=>
7940 when Attribute_Digits
=>
7941 Fold_Uint
(N
, Digits_Value
(P_Type
), Static
);
7947 when Attribute_Emax
=>
7949 -- Ada 83 attribute is defined as (RM83 3.5.8)
7951 -- T'Emax = 4 * T'Mantissa
7953 Fold_Uint
(N
, 4 * Mantissa
, Static
);
7959 when Attribute_Enum_Rep
=>
7961 -- For an enumeration type with a non-standard representation use
7962 -- the Enumeration_Rep field of the proper constant. Note that this
7963 -- will not work for types Character/Wide_[Wide-]Character, since no
7964 -- real entities are created for the enumeration literals, but that
7965 -- does not matter since these two types do not have non-standard
7966 -- representations anyway.
7968 if Is_Enumeration_Type
(P_Type
)
7969 and then Has_Non_Standard_Rep
(P_Type
)
7971 Fold_Uint
(N
, Enumeration_Rep
(Expr_Value_E
(E1
)), Static
);
7973 -- For enumeration types with standard representations and all
7974 -- other cases (i.e. all integer and modular types), Enum_Rep
7975 -- is equivalent to Pos.
7978 Fold_Uint
(N
, Expr_Value
(E1
), Static
);
7985 when Attribute_Enum_Val
=> Enum_Val
: declare
7989 -- We have something like Enum_Type'Enum_Val (23), so search for a
7990 -- corresponding value in the list of Enum_Rep values for the type.
7992 Lit
:= First_Literal
(P_Base_Type
);
7994 if Enumeration_Rep
(Lit
) = Expr_Value
(E1
) then
7995 Fold_Uint
(N
, Enumeration_Pos
(Lit
), Static
);
8002 Apply_Compile_Time_Constraint_Error
8003 (N
, "no representation value matches",
8004 CE_Range_Check_Failed
,
8005 Warn
=> not Static
);
8015 when Attribute_Epsilon
=>
8017 -- Ada 83 attribute is defined as (RM83 3.5.8)
8019 -- T'Epsilon = 2.0**(1 - T'Mantissa)
8021 Fold_Ureal
(N
, Ureal_2
** (1 - Mantissa
), True);
8027 when Attribute_Exponent
=>
8029 Eval_Fat
.Exponent
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8035 when Attribute_First
=> First_Attr
:
8039 if Compile_Time_Known_Value
(Lo_Bound
) then
8040 if Is_Real_Type
(P_Type
) then
8041 Fold_Ureal
(N
, Expr_Value_R
(Lo_Bound
), Static
);
8043 Fold_Uint
(N
, Expr_Value
(Lo_Bound
), Static
);
8047 Check_Concurrent_Discriminant
(Lo_Bound
);
8055 when Attribute_First_Valid
=> First_Valid
:
8057 if Has_Predicates
(P_Type
)
8058 and then Has_Static_Predicate
(P_Type
)
8061 FirstN
: constant Node_Id
:=
8062 First
(Static_Discrete_Predicate
(P_Type
));
8064 if Nkind
(FirstN
) = N_Range
then
8065 Fold_Uint
(N
, Expr_Value
(Low_Bound
(FirstN
)), Static
);
8067 Fold_Uint
(N
, Expr_Value
(FirstN
), Static
);
8073 Fold_Uint
(N
, Expr_Value
(Lo_Bound
), Static
);
8081 when Attribute_Fixed_Value
=>
8088 when Attribute_Floor
=>
8090 (N
, Eval_Fat
.Floor
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8096 when Attribute_Fore
=>
8097 if Compile_Time_Known_Bounds
(P_Type
) then
8098 Fold_Uint
(N
, UI_From_Int
(Fore_Value
), Static
);
8105 when Attribute_Fraction
=>
8107 (N
, Eval_Fat
.Fraction
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8109 -----------------------
8110 -- Has_Access_Values --
8111 -----------------------
8113 when Attribute_Has_Access_Values
=>
8114 Rewrite
(N
, New_Occurrence_Of
8115 (Boolean_Literals
(Has_Access_Values
(P_Root_Type
)), Loc
));
8116 Analyze_And_Resolve
(N
, Standard_Boolean
);
8118 -----------------------
8119 -- Has_Discriminants --
8120 -----------------------
8122 when Attribute_Has_Discriminants
=>
8123 Rewrite
(N
, New_Occurrence_Of
(
8124 Boolean_Literals
(Has_Discriminants
(P_Entity
)), Loc
));
8125 Analyze_And_Resolve
(N
, Standard_Boolean
);
8127 ----------------------
8128 -- Has_Same_Storage --
8129 ----------------------
8131 when Attribute_Has_Same_Storage
=>
8134 -----------------------
8135 -- Has_Tagged_Values --
8136 -----------------------
8138 when Attribute_Has_Tagged_Values
=>
8139 Rewrite
(N
, New_Occurrence_Of
8140 (Boolean_Literals
(Has_Tagged_Component
(P_Root_Type
)), Loc
));
8141 Analyze_And_Resolve
(N
, Standard_Boolean
);
8147 when Attribute_Identity
=>
8154 -- Image is a scalar attribute, but is never static, because it is
8155 -- not a static function (having a non-scalar argument (RM 4.9(22))
8156 -- However, we can constant-fold the image of an enumeration literal
8157 -- if names are available.
8159 when Attribute_Image
=>
8160 if Is_Entity_Name
(E1
)
8161 and then Ekind
(Entity
(E1
)) = E_Enumeration_Literal
8162 and then not Discard_Names
(First_Subtype
(Etype
(E1
)))
8163 and then not Global_Discard_Names
8166 Lit
: constant Entity_Id
:= Entity
(E1
);
8170 Get_Unqualified_Decoded_Name_String
(Chars
(Lit
));
8171 Set_Casing
(All_Upper_Case
);
8172 Store_String_Chars
(Name_Buffer
(1 .. Name_Len
));
8174 Rewrite
(N
, Make_String_Literal
(Loc
, Strval
=> Str
));
8175 Analyze_And_Resolve
(N
, Standard_String
);
8176 Set_Is_Static_Expression
(N
, False);
8184 -- We never try to fold Integer_Value (though perhaps we could???)
8186 when Attribute_Integer_Value
=>
8193 -- Invalid_Value is a scalar attribute that is never static, because
8194 -- the value is by design out of range.
8196 when Attribute_Invalid_Value
=>
8203 when Attribute_Large
=>
8205 -- For fixed-point, we use the identity:
8207 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
8209 if Is_Fixed_Point_Type
(P_Type
) then
8211 Make_Op_Multiply
(Loc
,
8213 Make_Op_Subtract
(Loc
,
8217 Make_Real_Literal
(Loc
, Ureal_2
),
8219 Make_Attribute_Reference
(Loc
,
8221 Attribute_Name
=> Name_Mantissa
)),
8222 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_1
)),
8225 Make_Real_Literal
(Loc
, Small_Value
(Entity
(P
)))));
8227 Analyze_And_Resolve
(N
, C_Type
);
8229 -- Floating-point (Ada 83 compatibility)
8232 -- Ada 83 attribute is defined as (RM83 3.5.8)
8234 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
8238 -- T'Emax = 4 * T'Mantissa
8242 Ureal_2
** (4 * Mantissa
) * (Ureal_1
- Ureal_2
** (-Mantissa
)),
8250 when Attribute_Lock_Free
=> Lock_Free
: declare
8251 V
: constant Entity_Id
:= Boolean_Literals
(Uses_Lock_Free
(P_Type
));
8254 Rewrite
(N
, New_Occurrence_Of
(V
, Loc
));
8256 -- Analyze and resolve as boolean. Note that this attribute is a
8257 -- static attribute in GNAT.
8259 Analyze_And_Resolve
(N
, Standard_Boolean
);
8261 Set_Is_Static_Expression
(N
, True);
8268 when Attribute_Last
=> Last_Attr
:
8272 if Compile_Time_Known_Value
(Hi_Bound
) then
8273 if Is_Real_Type
(P_Type
) then
8274 Fold_Ureal
(N
, Expr_Value_R
(Hi_Bound
), Static
);
8276 Fold_Uint
(N
, Expr_Value
(Hi_Bound
), Static
);
8280 Check_Concurrent_Discriminant
(Hi_Bound
);
8288 when Attribute_Last_Valid
=> Last_Valid
:
8290 if Has_Predicates
(P_Type
)
8291 and then Has_Static_Predicate
(P_Type
)
8294 LastN
: constant Node_Id
:=
8295 Last
(Static_Discrete_Predicate
(P_Type
));
8297 if Nkind
(LastN
) = N_Range
then
8298 Fold_Uint
(N
, Expr_Value
(High_Bound
(LastN
)), Static
);
8300 Fold_Uint
(N
, Expr_Value
(LastN
), Static
);
8306 Fold_Uint
(N
, Expr_Value
(Hi_Bound
), Static
);
8314 when Attribute_Leading_Part
=>
8317 Eval_Fat
.Leading_Part
8318 (P_Base_Type
, Expr_Value_R
(E1
), Expr_Value
(E2
)),
8325 when Attribute_Length
=> Length
: declare
8329 -- If any index type is a formal type, or derived from one, the
8330 -- bounds are not static. Treating them as static can produce
8331 -- spurious warnings or improper constant folding.
8333 Ind
:= First_Index
(P_Type
);
8334 while Present
(Ind
) loop
8335 if Is_Generic_Type
(Root_Type
(Etype
(Ind
))) then
8344 -- For two compile time values, we can compute length
8346 if Compile_Time_Known_Value
(Lo_Bound
)
8347 and then Compile_Time_Known_Value
(Hi_Bound
)
8350 UI_Max
(0, 1 + (Expr_Value
(Hi_Bound
) - Expr_Value
(Lo_Bound
))),
8354 -- One more case is where Hi_Bound and Lo_Bound are compile-time
8355 -- comparable, and we can figure out the difference between them.
8358 Diff
: aliased Uint
;
8362 Compile_Time_Compare
8363 (Lo_Bound
, Hi_Bound
, Diff
'Access, Assume_Valid
=> False)
8366 Fold_Uint
(N
, Uint_1
, Static
);
8369 Fold_Uint
(N
, Uint_0
, Static
);
8372 if Diff
/= No_Uint
then
8373 Fold_Uint
(N
, Diff
+ 1, Static
);
8386 -- Loop_Entry acts as an alias of a constant initialized to the prefix
8387 -- of the said attribute at the point of entry into the related loop. As
8388 -- such, the attribute reference does not need to be evaluated because
8389 -- the prefix is the one that is evaluted.
8391 when Attribute_Loop_Entry
=>
8398 when Attribute_Machine
=>
8402 (P_Base_Type
, Expr_Value_R
(E1
), Eval_Fat
.Round
, N
),
8409 when Attribute_Machine_Emax
=>
8410 Fold_Uint
(N
, Machine_Emax_Value
(P_Type
), Static
);
8416 when Attribute_Machine_Emin
=>
8417 Fold_Uint
(N
, Machine_Emin_Value
(P_Type
), Static
);
8419 ----------------------
8420 -- Machine_Mantissa --
8421 ----------------------
8423 when Attribute_Machine_Mantissa
=>
8424 Fold_Uint
(N
, Machine_Mantissa_Value
(P_Type
), Static
);
8426 -----------------------
8427 -- Machine_Overflows --
8428 -----------------------
8430 when Attribute_Machine_Overflows
=>
8432 -- Always true for fixed-point
8434 if Is_Fixed_Point_Type
(P_Type
) then
8435 Fold_Uint
(N
, True_Value
, Static
);
8437 -- Floating point case
8441 UI_From_Int
(Boolean'Pos (Machine_Overflows_On_Target
)),
8449 when Attribute_Machine_Radix
=>
8450 if Is_Fixed_Point_Type
(P_Type
) then
8451 if Is_Decimal_Fixed_Point_Type
(P_Type
)
8452 and then Machine_Radix_10
(P_Type
)
8454 Fold_Uint
(N
, Uint_10
, Static
);
8456 Fold_Uint
(N
, Uint_2
, Static
);
8459 -- All floating-point type always have radix 2
8462 Fold_Uint
(N
, Uint_2
, Static
);
8465 ----------------------
8466 -- Machine_Rounding --
8467 ----------------------
8469 -- Note: for the folding case, it is fine to treat Machine_Rounding
8470 -- exactly the same way as Rounding, since this is one of the allowed
8471 -- behaviors, and performance is not an issue here. It might be a bit
8472 -- better to give the same result as it would give at run time, even
8473 -- though the non-determinism is certainly permitted.
8475 when Attribute_Machine_Rounding
=>
8477 (N
, Eval_Fat
.Rounding
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8479 --------------------
8480 -- Machine_Rounds --
8481 --------------------
8483 when Attribute_Machine_Rounds
=>
8485 -- Always False for fixed-point
8487 if Is_Fixed_Point_Type
(P_Type
) then
8488 Fold_Uint
(N
, False_Value
, Static
);
8490 -- Else yield proper floating-point result
8494 (N
, UI_From_Int
(Boolean'Pos (Machine_Rounds_On_Target
)),
8502 -- Note: Machine_Size is identical to Object_Size
8504 when Attribute_Machine_Size
=> Machine_Size
: declare
8505 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
8508 if Known_Esize
(P_TypeA
) then
8509 Fold_Uint
(N
, Esize
(P_TypeA
), Static
);
8517 when Attribute_Mantissa
=>
8519 -- Fixed-point mantissa
8521 if Is_Fixed_Point_Type
(P_Type
) then
8523 -- Compile time foldable case
8525 if Compile_Time_Known_Value
(Type_Low_Bound
(P_Type
))
8527 Compile_Time_Known_Value
(Type_High_Bound
(P_Type
))
8529 -- The calculation of the obsolete Ada 83 attribute Mantissa
8530 -- is annoying, because of AI00143, quoted here:
8532 -- !question 84-01-10
8534 -- Consider the model numbers for F:
8536 -- type F is delta 1.0 range -7.0 .. 8.0;
8538 -- The wording requires that F'MANTISSA be the SMALLEST
8539 -- integer number for which each bound of the specified
8540 -- range is either a model number or lies at most small
8541 -- distant from a model number. This means F'MANTISSA
8542 -- is required to be 3 since the range -7.0 .. 7.0 fits
8543 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
8544 -- number, namely, 7. Is this analysis correct? Note that
8545 -- this implies the upper bound of the range is not
8546 -- represented as a model number.
8548 -- !response 84-03-17
8550 -- The analysis is correct. The upper and lower bounds for
8551 -- a fixed point type can lie outside the range of model
8562 LBound
:= Expr_Value_R
(Type_Low_Bound
(P_Type
));
8563 UBound
:= Expr_Value_R
(Type_High_Bound
(P_Type
));
8564 Bound
:= UR_Max
(UR_Abs
(LBound
), UR_Abs
(UBound
));
8565 Max_Man
:= UR_Trunc
(Bound
/ Small_Value
(P_Type
));
8567 -- If the Bound is exactly a model number, i.e. a multiple
8568 -- of Small, then we back it off by one to get the integer
8569 -- value that must be representable.
8571 if Small_Value
(P_Type
) * Max_Man
= Bound
then
8572 Max_Man
:= Max_Man
- 1;
8575 -- Now find corresponding size = Mantissa value
8578 while 2 ** Siz
< Max_Man
loop
8582 Fold_Uint
(N
, Siz
, Static
);
8586 -- The case of dynamic bounds cannot be evaluated at compile
8587 -- time. Instead we use a runtime routine (see Exp_Attr).
8592 -- Floating-point Mantissa
8595 Fold_Uint
(N
, Mantissa
, Static
);
8602 when Attribute_Max
=> Max
:
8604 if Is_Real_Type
(P_Type
) then
8606 (N
, UR_Max
(Expr_Value_R
(E1
), Expr_Value_R
(E2
)), Static
);
8608 Fold_Uint
(N
, UI_Max
(Expr_Value
(E1
), Expr_Value
(E2
)), Static
);
8612 ----------------------------------
8613 -- Max_Alignment_For_Allocation --
8614 ----------------------------------
8616 -- Max_Alignment_For_Allocation is usually the Alignment. However,
8617 -- arrays are allocated with dope, so we need to take into account both
8618 -- the alignment of the array, which comes from the component alignment,
8619 -- and the alignment of the dope. Also, if the alignment is unknown, we
8620 -- use the max (it's OK to be pessimistic).
8622 when Attribute_Max_Alignment_For_Allocation
=>
8624 A
: Uint
:= UI_From_Int
(Ttypes
.Maximum_Alignment
);
8626 if Known_Alignment
(P_Type
) and then
8627 (not Is_Array_Type
(P_Type
) or else Alignment
(P_Type
) > A
)
8629 A
:= Alignment
(P_Type
);
8632 Fold_Uint
(N
, A
, Static
);
8635 ----------------------------------
8636 -- Max_Size_In_Storage_Elements --
8637 ----------------------------------
8639 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
8640 -- Storage_Unit boundary. We can fold any cases for which the size
8641 -- is known by the front end.
8643 when Attribute_Max_Size_In_Storage_Elements
=>
8644 if Known_Esize
(P_Type
) then
8646 (Esize
(P_Type
) + System_Storage_Unit
- 1) /
8647 System_Storage_Unit
,
8651 --------------------
8652 -- Mechanism_Code --
8653 --------------------
8655 when Attribute_Mechanism_Code
=>
8659 Mech
: Mechanism_Type
;
8663 Mech
:= Mechanism
(P_Entity
);
8666 Val
:= UI_To_Int
(Expr_Value
(E1
));
8668 Formal
:= First_Formal
(P_Entity
);
8669 for J
in 1 .. Val
- 1 loop
8670 Next_Formal
(Formal
);
8672 Mech
:= Mechanism
(Formal
);
8676 Fold_Uint
(N
, UI_From_Int
(Int
(-Mech
)), Static
);
8684 when Attribute_Min
=> Min
:
8686 if Is_Real_Type
(P_Type
) then
8688 (N
, UR_Min
(Expr_Value_R
(E1
), Expr_Value_R
(E2
)), Static
);
8691 (N
, UI_Min
(Expr_Value
(E1
), Expr_Value
(E2
)), Static
);
8699 when Attribute_Mod
=>
8701 (N
, UI_Mod
(Expr_Value
(E1
), Modulus
(P_Base_Type
)), Static
);
8707 when Attribute_Model
=>
8709 (N
, Eval_Fat
.Model
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8715 when Attribute_Model_Emin
=>
8716 Fold_Uint
(N
, Model_Emin_Value
(P_Base_Type
), Static
);
8722 when Attribute_Model_Epsilon
=>
8723 Fold_Ureal
(N
, Model_Epsilon_Value
(P_Base_Type
), Static
);
8725 --------------------
8726 -- Model_Mantissa --
8727 --------------------
8729 when Attribute_Model_Mantissa
=>
8730 Fold_Uint
(N
, Model_Mantissa_Value
(P_Base_Type
), Static
);
8736 when Attribute_Model_Small
=>
8737 Fold_Ureal
(N
, Model_Small_Value
(P_Base_Type
), Static
);
8743 when Attribute_Modulus
=>
8744 Fold_Uint
(N
, Modulus
(P_Type
), Static
);
8746 --------------------
8747 -- Null_Parameter --
8748 --------------------
8750 -- Cannot fold, we know the value sort of, but the whole point is
8751 -- that there is no way to talk about this imaginary value except
8752 -- by using the attribute, so we leave it the way it is.
8754 when Attribute_Null_Parameter
=>
8761 -- The Object_Size attribute for a type returns the Esize of the
8762 -- type and can be folded if this value is known.
8764 when Attribute_Object_Size
=> Object_Size
: declare
8765 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
8768 if Known_Esize
(P_TypeA
) then
8769 Fold_Uint
(N
, Esize
(P_TypeA
), Static
);
8773 ----------------------
8774 -- Overlaps_Storage --
8775 ----------------------
8777 when Attribute_Overlaps_Storage
=>
8780 -------------------------
8781 -- Passed_By_Reference --
8782 -------------------------
8784 -- Scalar types are never passed by reference
8786 when Attribute_Passed_By_Reference
=>
8787 Fold_Uint
(N
, False_Value
, Static
);
8793 when Attribute_Pos
=>
8794 Fold_Uint
(N
, Expr_Value
(E1
), Static
);
8800 when Attribute_Pred
=> Pred
:
8802 -- Floating-point case
8804 if Is_Floating_Point_Type
(P_Type
) then
8806 (N
, Eval_Fat
.Pred
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8810 elsif Is_Fixed_Point_Type
(P_Type
) then
8812 (N
, Expr_Value_R
(E1
) - Small_Value
(P_Type
), True);
8814 -- Modular integer case (wraps)
8816 elsif Is_Modular_Integer_Type
(P_Type
) then
8817 Fold_Uint
(N
, (Expr_Value
(E1
) - 1) mod Modulus
(P_Type
), Static
);
8819 -- Other scalar cases
8822 pragma Assert
(Is_Scalar_Type
(P_Type
));
8824 if Is_Enumeration_Type
(P_Type
)
8825 and then Expr_Value
(E1
) =
8826 Expr_Value
(Type_Low_Bound
(P_Base_Type
))
8828 Apply_Compile_Time_Constraint_Error
8829 (N
, "Pred of `&''First`",
8830 CE_Overflow_Check_Failed
,
8832 Warn
=> not Static
);
8838 Fold_Uint
(N
, Expr_Value
(E1
) - 1, Static
);
8846 -- No processing required, because by this stage, Range has been
8847 -- replaced by First .. Last, so this branch can never be taken.
8849 when Attribute_Range
=>
8850 raise Program_Error
;
8856 when Attribute_Range_Length
=>
8859 -- Can fold if both bounds are compile time known
8861 if Compile_Time_Known_Value
(Hi_Bound
)
8862 and then Compile_Time_Known_Value
(Lo_Bound
)
8866 (0, Expr_Value
(Hi_Bound
) - Expr_Value
(Lo_Bound
) + 1),
8870 -- One more case is where Hi_Bound and Lo_Bound are compile-time
8871 -- comparable, and we can figure out the difference between them.
8874 Diff
: aliased Uint
;
8878 Compile_Time_Compare
8879 (Lo_Bound
, Hi_Bound
, Diff
'Access, Assume_Valid
=> False)
8882 Fold_Uint
(N
, Uint_1
, Static
);
8885 Fold_Uint
(N
, Uint_0
, Static
);
8888 if Diff
/= No_Uint
then
8889 Fold_Uint
(N
, Diff
+ 1, Static
);
8901 when Attribute_Ref
=>
8902 Fold_Uint
(N
, Expr_Value
(E1
), Static
);
8908 when Attribute_Remainder
=> Remainder
: declare
8909 X
: constant Ureal
:= Expr_Value_R
(E1
);
8910 Y
: constant Ureal
:= Expr_Value_R
(E2
);
8913 if UR_Is_Zero
(Y
) then
8914 Apply_Compile_Time_Constraint_Error
8915 (N
, "division by zero in Remainder",
8916 CE_Overflow_Check_Failed
,
8917 Warn
=> not Static
);
8923 Fold_Ureal
(N
, Eval_Fat
.Remainder
(P_Base_Type
, X
, Y
), Static
);
8930 when Attribute_Restriction_Set
=> Restriction_Set
: declare
8932 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
8933 Set_Is_Static_Expression
(N
);
8934 end Restriction_Set
;
8940 when Attribute_Round
=> Round
:
8946 -- First we get the (exact result) in units of small
8948 Sr
:= Expr_Value_R
(E1
) / Small_Value
(C_Type
);
8950 -- Now round that exactly to an integer
8952 Si
:= UR_To_Uint
(Sr
);
8954 -- Finally the result is obtained by converting back to real
8956 Fold_Ureal
(N
, Si
* Small_Value
(C_Type
), Static
);
8963 when Attribute_Rounding
=>
8965 (N
, Eval_Fat
.Rounding
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
8971 when Attribute_Safe_Emax
=>
8972 Fold_Uint
(N
, Safe_Emax_Value
(P_Type
), Static
);
8978 when Attribute_Safe_First
=>
8979 Fold_Ureal
(N
, Safe_First_Value
(P_Type
), Static
);
8985 when Attribute_Safe_Large
=>
8986 if Is_Fixed_Point_Type
(P_Type
) then
8988 (N
, Expr_Value_R
(Type_High_Bound
(P_Base_Type
)), Static
);
8990 Fold_Ureal
(N
, Safe_Last_Value
(P_Type
), Static
);
8997 when Attribute_Safe_Last
=>
8998 Fold_Ureal
(N
, Safe_Last_Value
(P_Type
), Static
);
9004 when Attribute_Safe_Small
=>
9006 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
9007 -- for fixed-point, since is the same as Small, but we implement
9008 -- it for backwards compatibility.
9010 if Is_Fixed_Point_Type
(P_Type
) then
9011 Fold_Ureal
(N
, Small_Value
(P_Type
), Static
);
9013 -- Ada 83 Safe_Small for floating-point cases
9016 Fold_Ureal
(N
, Model_Small_Value
(P_Type
), Static
);
9023 when Attribute_Scale
=>
9024 Fold_Uint
(N
, Scale_Value
(P_Type
), Static
);
9030 when Attribute_Scaling
=>
9034 (P_Base_Type
, Expr_Value_R
(E1
), Expr_Value
(E2
)),
9041 when Attribute_Signed_Zeros
=>
9043 (N
, UI_From_Int
(Boolean'Pos (Has_Signed_Zeros
(P_Type
))), Static
);
9049 -- Size attribute returns the RM size. All scalar types can be folded,
9050 -- as well as any types for which the size is known by the front end,
9051 -- including any type for which a size attribute is specified. This is
9052 -- one of the places where it is annoying that a size of zero means two
9053 -- things (zero size for scalars, unspecified size for non-scalars).
9055 when Attribute_Size | Attribute_VADS_Size
=> Size
: declare
9056 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
9059 if Is_Scalar_Type
(P_TypeA
) or else RM_Size
(P_TypeA
) /= Uint_0
then
9063 if Id
= Attribute_VADS_Size
or else Use_VADS_Size
then
9065 S
: constant Node_Id
:= Size_Clause
(P_TypeA
);
9068 -- If a size clause applies, then use the size from it.
9069 -- This is one of the rare cases where we can use the
9070 -- Size_Clause field for a subtype when Has_Size_Clause
9071 -- is False. Consider:
9073 -- type x is range 1 .. 64;
9074 -- for x'size use 12;
9075 -- subtype y is x range 0 .. 3;
9077 -- Here y has a size clause inherited from x, but normally
9078 -- it does not apply, and y'size is 2. However, y'VADS_Size
9079 -- is indeed 12 and not 2.
9082 and then Is_OK_Static_Expression
(Expression
(S
))
9084 Fold_Uint
(N
, Expr_Value
(Expression
(S
)), Static
);
9086 -- If no size is specified, then we simply use the object
9087 -- size in the VADS_Size case (e.g. Natural'Size is equal
9088 -- to Integer'Size, not one less).
9091 Fold_Uint
(N
, Esize
(P_TypeA
), Static
);
9095 -- Normal case (Size) in which case we want the RM_Size
9098 Fold_Uint
(N
, RM_Size
(P_TypeA
), Static
);
9107 when Attribute_Small
=>
9109 -- The floating-point case is present only for Ada 83 compatibility.
9110 -- Note that strictly this is an illegal addition, since we are
9111 -- extending an Ada 95 defined attribute, but we anticipate an
9112 -- ARG ruling that will permit this.
9114 if Is_Floating_Point_Type
(P_Type
) then
9116 -- Ada 83 attribute is defined as (RM83 3.5.8)
9118 -- T'Small = 2.0**(-T'Emax - 1)
9122 -- T'Emax = 4 * T'Mantissa
9124 Fold_Ureal
(N
, Ureal_2
** ((-(4 * Mantissa
)) - 1), Static
);
9126 -- Normal Ada 95 fixed-point case
9129 Fold_Ureal
(N
, Small_Value
(P_Type
), True);
9136 when Attribute_Stream_Size
=>
9143 when Attribute_Succ
=> Succ
:
9145 -- Floating-point case
9147 if Is_Floating_Point_Type
(P_Type
) then
9149 (N
, Eval_Fat
.Succ
(P_Base_Type
, Expr_Value_R
(E1
)), Static
);
9153 elsif Is_Fixed_Point_Type
(P_Type
) then
9154 Fold_Ureal
(N
, Expr_Value_R
(E1
) + Small_Value
(P_Type
), Static
);
9156 -- Modular integer case (wraps)
9158 elsif Is_Modular_Integer_Type
(P_Type
) then
9159 Fold_Uint
(N
, (Expr_Value
(E1
) + 1) mod Modulus
(P_Type
), Static
);
9161 -- Other scalar cases
9164 pragma Assert
(Is_Scalar_Type
(P_Type
));
9166 if Is_Enumeration_Type
(P_Type
)
9167 and then Expr_Value
(E1
) =
9168 Expr_Value
(Type_High_Bound
(P_Base_Type
))
9170 Apply_Compile_Time_Constraint_Error
9171 (N
, "Succ of `&''Last`",
9172 CE_Overflow_Check_Failed
,
9174 Warn
=> not Static
);
9179 Fold_Uint
(N
, Expr_Value
(E1
) + 1, Static
);
9188 when Attribute_Truncation
=>
9191 Eval_Fat
.Truncation
(P_Base_Type
, Expr_Value_R
(E1
)),
9198 when Attribute_Type_Class
=> Type_Class
: declare
9199 Typ
: constant Entity_Id
:= Underlying_Type
(P_Base_Type
);
9203 if Is_Descendent_Of_Address
(Typ
) then
9204 Id
:= RE_Type_Class_Address
;
9206 elsif Is_Enumeration_Type
(Typ
) then
9207 Id
:= RE_Type_Class_Enumeration
;
9209 elsif Is_Integer_Type
(Typ
) then
9210 Id
:= RE_Type_Class_Integer
;
9212 elsif Is_Fixed_Point_Type
(Typ
) then
9213 Id
:= RE_Type_Class_Fixed_Point
;
9215 elsif Is_Floating_Point_Type
(Typ
) then
9216 Id
:= RE_Type_Class_Floating_Point
;
9218 elsif Is_Array_Type
(Typ
) then
9219 Id
:= RE_Type_Class_Array
;
9221 elsif Is_Record_Type
(Typ
) then
9222 Id
:= RE_Type_Class_Record
;
9224 elsif Is_Access_Type
(Typ
) then
9225 Id
:= RE_Type_Class_Access
;
9227 elsif Is_Enumeration_Type
(Typ
) then
9228 Id
:= RE_Type_Class_Enumeration
;
9230 elsif Is_Task_Type
(Typ
) then
9231 Id
:= RE_Type_Class_Task
;
9233 -- We treat protected types like task types. It would make more
9234 -- sense to have another enumeration value, but after all the
9235 -- whole point of this feature is to be exactly DEC compatible,
9236 -- and changing the type Type_Class would not meet this requirement.
9238 elsif Is_Protected_Type
(Typ
) then
9239 Id
:= RE_Type_Class_Task
;
9241 -- Not clear if there are any other possibilities, but if there
9242 -- are, then we will treat them as the address case.
9245 Id
:= RE_Type_Class_Address
;
9248 Rewrite
(N
, New_Occurrence_Of
(RTE
(Id
), Loc
));
9251 -----------------------
9252 -- Unbiased_Rounding --
9253 -----------------------
9255 when Attribute_Unbiased_Rounding
=>
9258 Eval_Fat
.Unbiased_Rounding
(P_Base_Type
, Expr_Value_R
(E1
)),
9261 -------------------------
9262 -- Unconstrained_Array --
9263 -------------------------
9265 when Attribute_Unconstrained_Array
=> Unconstrained_Array
: declare
9266 Typ
: constant Entity_Id
:= Underlying_Type
(P_Type
);
9269 Rewrite
(N
, New_Occurrence_Of
(
9271 Is_Array_Type
(P_Type
)
9272 and then not Is_Constrained
(Typ
)), Loc
));
9274 -- Analyze and resolve as boolean, note that this attribute is
9275 -- a static attribute in GNAT.
9277 Analyze_And_Resolve
(N
, Standard_Boolean
);
9279 Set_Is_Static_Expression
(N
, True);
9280 end Unconstrained_Array
;
9282 -- Attribute Update is never static
9284 when Attribute_Update
=>
9291 -- Processing is shared with Size
9297 when Attribute_Val
=> Val
:
9299 if Expr_Value
(E1
) < Expr_Value
(Type_Low_Bound
(P_Base_Type
))
9301 Expr_Value
(E1
) > Expr_Value
(Type_High_Bound
(P_Base_Type
))
9303 Apply_Compile_Time_Constraint_Error
9304 (N
, "Val expression out of range",
9305 CE_Range_Check_Failed
,
9306 Warn
=> not Static
);
9312 Fold_Uint
(N
, Expr_Value
(E1
), Static
);
9320 -- The Value_Size attribute for a type returns the RM size of the type.
9321 -- This an always be folded for scalar types, and can also be folded for
9322 -- non-scalar types if the size is set. This is one of the places where
9323 -- it is annoying that a size of zero means two things!
9325 when Attribute_Value_Size
=> Value_Size
: declare
9326 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
9328 if Is_Scalar_Type
(P_TypeA
) or else RM_Size
(P_TypeA
) /= Uint_0
then
9329 Fold_Uint
(N
, RM_Size
(P_TypeA
), Static
);
9337 -- Version can never be static
9339 when Attribute_Version
=>
9346 -- Wide_Image is a scalar attribute, but is never static, because it
9347 -- is not a static function (having a non-scalar argument (RM 4.9(22))
9349 when Attribute_Wide_Image
=>
9352 ---------------------
9353 -- Wide_Wide_Image --
9354 ---------------------
9356 -- Wide_Wide_Image is a scalar attribute but is never static, because it
9357 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
9359 when Attribute_Wide_Wide_Image
=>
9362 ---------------------
9363 -- Wide_Wide_Width --
9364 ---------------------
9366 -- Processing for Wide_Wide_Width is combined with Width
9372 -- Processing for Wide_Width is combined with Width
9378 -- This processing also handles the case of Wide_[Wide_]Width
9380 when Attribute_Width |
9381 Attribute_Wide_Width |
9382 Attribute_Wide_Wide_Width
=> Width
:
9384 if Compile_Time_Known_Bounds
(P_Type
) then
9386 -- Floating-point types
9388 if Is_Floating_Point_Type
(P_Type
) then
9390 -- Width is zero for a null range (RM 3.5 (38))
9392 if Expr_Value_R
(Type_High_Bound
(P_Type
)) <
9393 Expr_Value_R
(Type_Low_Bound
(P_Type
))
9395 Fold_Uint
(N
, Uint_0
, Static
);
9398 -- For floating-point, we have +N.dddE+nnn where length
9399 -- of ddd is determined by type'Digits - 1, but is one
9400 -- if Digits is one (RM 3.5 (33)).
9402 -- nnn is set to 2 for Short_Float and Float (32 bit
9403 -- floats), and 3 for Long_Float and Long_Long_Float.
9404 -- For machines where Long_Long_Float is the IEEE
9405 -- extended precision type, the exponent takes 4 digits.
9409 Int
'Max (2, UI_To_Int
(Digits_Value
(P_Type
)));
9412 if Esize
(P_Type
) <= 32 then
9414 elsif Esize
(P_Type
) = 64 then
9420 Fold_Uint
(N
, UI_From_Int
(Len
), Static
);
9424 -- Fixed-point types
9426 elsif Is_Fixed_Point_Type
(P_Type
) then
9428 -- Width is zero for a null range (RM 3.5 (38))
9430 if Expr_Value
(Type_High_Bound
(P_Type
)) <
9431 Expr_Value
(Type_Low_Bound
(P_Type
))
9433 Fold_Uint
(N
, Uint_0
, Static
);
9435 -- The non-null case depends on the specific real type
9438 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
9441 (N
, UI_From_Int
(Fore_Value
+ 1) + Aft_Value
(P_Type
),
9449 R
: constant Entity_Id
:= Root_Type
(P_Type
);
9450 Lo
: constant Uint
:= Expr_Value
(Type_Low_Bound
(P_Type
));
9451 Hi
: constant Uint
:= Expr_Value
(Type_High_Bound
(P_Type
));
9464 -- Width for types derived from Standard.Character
9465 -- and Standard.Wide_[Wide_]Character.
9467 elsif Is_Standard_Character_Type
(P_Type
) then
9470 -- Set W larger if needed
9472 for J
in UI_To_Int
(Lo
) .. UI_To_Int
(Hi
) loop
9474 -- All wide characters look like Hex_hhhhhhhh
9478 -- No need to compute this more than once
9483 C
:= Character'Val (J
);
9485 -- Test for all cases where Character'Image
9486 -- yields an image that is longer than three
9487 -- characters. First the cases of Reserved_xxx
9488 -- names (length = 12).
9491 when Reserved_128 | Reserved_129 |
9492 Reserved_132 | Reserved_153
9495 when BS | HT | LF | VT | FF | CR |
9496 SO | SI | EM | FS | GS | RS |
9497 US | RI | MW | ST | PM
9500 when NUL | SOH | STX | ETX | EOT |
9501 ENQ | ACK | BEL | DLE | DC1 |
9502 DC2 | DC3 | DC4 | NAK | SYN |
9503 ETB | CAN | SUB | ESC | DEL |
9504 BPH | NBH | NEL | SSA | ESA |
9505 HTS | HTJ | VTS | PLD | PLU |
9506 SS2 | SS3 | DCS | PU1 | PU2 |
9507 STS | CCH | SPA | EPA | SOS |
9508 SCI | CSI | OSC | APC
9511 when Space
.. Tilde |
9512 No_Break_Space
.. LC_Y_Diaeresis
9514 -- Special case of soft hyphen in Ada 2005
9516 if C
= Character'Val (16#AD#
)
9517 and then Ada_Version
>= Ada_2005
9525 W
:= Int
'Max (W
, Wt
);
9529 -- Width for types derived from Standard.Boolean
9531 elsif R
= Standard_Boolean
then
9538 -- Width for integer types
9540 elsif Is_Integer_Type
(P_Type
) then
9541 T
:= UI_Max
(abs Lo
, abs Hi
);
9549 -- User declared enum type with discard names
9551 elsif Discard_Names
(R
) then
9553 -- If range is null, result is zero, that has already
9554 -- been dealt with, so what we need is the power of ten
9555 -- that accomodates the Pos of the largest value, which
9556 -- is the high bound of the range + one for the space.
9565 -- Only remaining possibility is user declared enum type
9566 -- with normal case of Discard_Names not active.
9569 pragma Assert
(Is_Enumeration_Type
(P_Type
));
9572 L
:= First_Literal
(P_Type
);
9573 while Present
(L
) loop
9575 -- Only pay attention to in range characters
9577 if Lo
<= Enumeration_Pos
(L
)
9578 and then Enumeration_Pos
(L
) <= Hi
9580 -- For Width case, use decoded name
9582 if Id
= Attribute_Width
then
9583 Get_Decoded_Name_String
(Chars
(L
));
9584 Wt
:= Nat
(Name_Len
);
9586 -- For Wide_[Wide_]Width, use encoded name, and
9587 -- then adjust for the encoding.
9590 Get_Name_String
(Chars
(L
));
9592 -- Character literals are always of length 3
9594 if Name_Buffer
(1) = 'Q' then
9597 -- Otherwise loop to adjust for upper/wide chars
9600 Wt
:= Nat
(Name_Len
);
9602 for J
in 1 .. Name_Len
loop
9603 if Name_Buffer
(J
) = 'U' then
9605 elsif Name_Buffer
(J
) = 'W' then
9612 W
:= Int
'Max (W
, Wt
);
9619 Fold_Uint
(N
, UI_From_Int
(W
), Static
);
9625 -- The following attributes denote functions that cannot be folded
9627 when Attribute_From_Any |
9629 Attribute_TypeCode
=>
9632 -- The following attributes can never be folded, and furthermore we
9633 -- should not even have entered the case statement for any of these.
9634 -- Note that in some cases, the values have already been folded as
9635 -- a result of the processing in Analyze_Attribute or earlier in
9638 when Attribute_Abort_Signal |
9641 Attribute_Address_Size |
9642 Attribute_Asm_Input |
9643 Attribute_Asm_Output |
9645 Attribute_Bit_Order |
9646 Attribute_Bit_Position |
9647 Attribute_Callable |
9650 Attribute_Code_Address |
9651 Attribute_Compiler_Version |
9653 Attribute_Default_Bit_Order |
9654 Attribute_Default_Scalar_Storage_Order |
9656 Attribute_Elaborated |
9657 Attribute_Elab_Body |
9658 Attribute_Elab_Spec |
9659 Attribute_Elab_Subp_Body |
9661 Attribute_External_Tag |
9662 Attribute_Fast_Math |
9663 Attribute_First_Bit |
9666 Attribute_Last_Bit |
9667 Attribute_Library_Level |
9668 Attribute_Maximum_Alignment |
9671 Attribute_Partition_ID |
9672 Attribute_Pool_Address |
9673 Attribute_Position |
9674 Attribute_Priority |
9677 Attribute_Scalar_Storage_Order |
9678 Attribute_Simple_Storage_Pool |
9679 Attribute_Storage_Pool |
9680 Attribute_Storage_Size |
9681 Attribute_Storage_Unit |
9682 Attribute_Stub_Type |
9683 Attribute_System_Allocator_Alignment |
9685 Attribute_Target_Name |
9686 Attribute_Terminated |
9687 Attribute_To_Address |
9688 Attribute_Type_Key |
9689 Attribute_UET_Address |
9690 Attribute_Unchecked_Access |
9691 Attribute_Universal_Literal_String |
9692 Attribute_Unrestricted_Access |
9694 Attribute_Valid_Scalars |
9696 Attribute_Wchar_T_Size |
9697 Attribute_Wide_Value |
9698 Attribute_Wide_Wide_Value |
9699 Attribute_Word_Size |
9702 raise Program_Error
;
9705 -- At the end of the case, one more check. If we did a static evaluation
9706 -- so that the result is now a literal, then set Is_Static_Expression
9707 -- in the constant only if the prefix type is a static subtype. For
9708 -- non-static subtypes, the folding is still OK, but not static.
9710 -- An exception is the GNAT attribute Constrained_Array which is
9711 -- defined to be a static attribute in all cases.
9713 if Nkind_In
(N
, N_Integer_Literal
,
9715 N_Character_Literal
,
9717 or else (Is_Entity_Name
(N
)
9718 and then Ekind
(Entity
(N
)) = E_Enumeration_Literal
)
9720 Set_Is_Static_Expression
(N
, Static
);
9722 -- If this is still an attribute reference, then it has not been folded
9723 -- and that means that its expressions are in a non-static context.
9725 elsif Nkind
(N
) = N_Attribute_Reference
then
9728 -- Note: the else case not covered here are odd cases where the
9729 -- processing has transformed the attribute into something other
9730 -- than a constant. Nothing more to do in such cases.
9737 ------------------------------
9738 -- Is_Anonymous_Tagged_Base --
9739 ------------------------------
9741 function Is_Anonymous_Tagged_Base
9743 Typ
: Entity_Id
) return Boolean
9747 Anon
= Current_Scope
9748 and then Is_Itype
(Anon
)
9749 and then Associated_Node_For_Itype
(Anon
) = Parent
(Typ
);
9750 end Is_Anonymous_Tagged_Base
;
9752 --------------------------------
9753 -- Name_Implies_Lvalue_Prefix --
9754 --------------------------------
9756 function Name_Implies_Lvalue_Prefix
(Nam
: Name_Id
) return Boolean is
9757 pragma Assert
(Is_Attribute_Name
(Nam
));
9759 return Attribute_Name_Implies_Lvalue_Prefix
(Get_Attribute_Id
(Nam
));
9760 end Name_Implies_Lvalue_Prefix
;
9762 -----------------------
9763 -- Resolve_Attribute --
9764 -----------------------
9766 procedure Resolve_Attribute
(N
: Node_Id
; Typ
: Entity_Id
) is
9767 Loc
: constant Source_Ptr
:= Sloc
(N
);
9768 P
: constant Node_Id
:= Prefix
(N
);
9769 Aname
: constant Name_Id
:= Attribute_Name
(N
);
9770 Attr_Id
: constant Attribute_Id
:= Get_Attribute_Id
(Aname
);
9771 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
9772 Des_Btyp
: Entity_Id
;
9773 Index
: Interp_Index
;
9775 Nom_Subt
: Entity_Id
;
9777 procedure Accessibility_Message
;
9778 -- Error, or warning within an instance, if the static accessibility
9779 -- rules of 3.10.2 are violated.
9781 function Declared_Within_Generic_Unit
9782 (Entity
: Entity_Id
;
9783 Generic_Unit
: Node_Id
) return Boolean;
9784 -- Returns True if Declared_Entity is declared within the declarative
9785 -- region of Generic_Unit; otherwise returns False.
9787 ---------------------------
9788 -- Accessibility_Message --
9789 ---------------------------
9791 procedure Accessibility_Message
is
9792 Indic
: Node_Id
:= Parent
(Parent
(N
));
9795 -- In an instance, this is a runtime check, but one we
9796 -- know will fail, so generate an appropriate warning.
9798 if In_Instance_Body
then
9799 Error_Msg_Warn
:= SPARK_Mode
/= On
;
9801 ("non-local pointer cannot point to local object<<", P
);
9802 Error_Msg_F
("\Program_Error [<<", P
);
9804 Make_Raise_Program_Error
(Loc
,
9805 Reason
=> PE_Accessibility_Check_Failed
));
9810 Error_Msg_F
("non-local pointer cannot point to local object", P
);
9812 -- Check for case where we have a missing access definition
9814 if Is_Record_Type
(Current_Scope
)
9816 Nkind_In
(Parent
(N
), N_Discriminant_Association
,
9817 N_Index_Or_Discriminant_Constraint
)
9819 Indic
:= Parent
(Parent
(N
));
9820 while Present
(Indic
)
9821 and then Nkind
(Indic
) /= N_Subtype_Indication
9823 Indic
:= Parent
(Indic
);
9826 if Present
(Indic
) then
9828 ("\use an access definition for" &
9829 " the access discriminant of&",
9830 N
, Entity
(Subtype_Mark
(Indic
)));
9834 end Accessibility_Message
;
9836 ----------------------------------
9837 -- Declared_Within_Generic_Unit --
9838 ----------------------------------
9840 function Declared_Within_Generic_Unit
9841 (Entity
: Entity_Id
;
9842 Generic_Unit
: Node_Id
) return Boolean
9844 Generic_Encloser
: Node_Id
:= Enclosing_Generic_Unit
(Entity
);
9847 while Present
(Generic_Encloser
) loop
9848 if Generic_Encloser
= Generic_Unit
then
9852 -- We have to step to the scope of the generic's entity, because
9853 -- otherwise we'll just get back the same generic.
9856 Enclosing_Generic_Unit
9857 (Scope
(Defining_Entity
(Generic_Encloser
)));
9861 end Declared_Within_Generic_Unit
;
9863 -- Start of processing for Resolve_Attribute
9866 -- If error during analysis, no point in continuing, except for array
9867 -- types, where we get better recovery by using unconstrained indexes
9868 -- than nothing at all (see Check_Array_Type).
9871 and then Attr_Id
/= Attribute_First
9872 and then Attr_Id
/= Attribute_Last
9873 and then Attr_Id
/= Attribute_Length
9874 and then Attr_Id
/= Attribute_Range
9879 -- If attribute was universal type, reset to actual type
9881 if Etype
(N
) = Universal_Integer
9882 or else Etype
(N
) = Universal_Real
9887 -- Remaining processing depends on attribute
9895 -- For access attributes, if the prefix denotes an entity, it is
9896 -- interpreted as a name, never as a call. It may be overloaded,
9897 -- in which case resolution uses the profile of the context type.
9898 -- Otherwise prefix must be resolved.
9900 when Attribute_Access
9901 | Attribute_Unchecked_Access
9902 | Attribute_Unrestricted_Access
=>
9906 -- Note possible modification if we have a variable
9908 if Is_Variable
(P
) then
9910 PN
: constant Node_Id
:= Parent
(N
);
9913 Note
: Boolean := True;
9914 -- Skip this for the case of Unrestricted_Access occuring in
9915 -- the context of a Valid check, since this otherwise leads
9916 -- to a missed warning (the Valid check does not really
9917 -- modify!) If this case, Note will be reset to False.
9920 if Attr_Id
= Attribute_Unrestricted_Access
9921 and then Nkind
(PN
) = N_Function_Call
9925 if Nkind
(Nm
) = N_Expanded_Name
9926 and then Chars
(Nm
) = Name_Valid
9927 and then Nkind
(Prefix
(Nm
)) = N_Identifier
9928 and then Chars
(Prefix
(Nm
)) = Name_Attr_Long_Float
9935 Note_Possible_Modification
(P
, Sure
=> False);
9940 -- The following comes from a query concerning improper use of
9941 -- universal_access in equality tests involving anonymous access
9942 -- types. Another good reason for 'Ref, but for now disable the
9943 -- test, which breaks several filed tests???
9945 if Ekind
(Typ
) = E_Anonymous_Access_Type
9946 and then Nkind_In
(Parent
(N
), N_Op_Eq
, N_Op_Ne
)
9949 Error_Msg_N
("need unique type to resolve 'Access", N
);
9950 Error_Msg_N
("\qualify attribute with some access type", N
);
9953 -- Case where prefix is an entity name
9955 if Is_Entity_Name
(P
) then
9957 -- Deal with case where prefix itself is overloaded
9959 if Is_Overloaded
(P
) then
9960 Get_First_Interp
(P
, Index
, It
);
9961 while Present
(It
.Nam
) loop
9962 if Type_Conformant
(Designated_Type
(Typ
), It
.Nam
) then
9963 Set_Entity
(P
, It
.Nam
);
9965 -- The prefix is definitely NOT overloaded anymore at
9966 -- this point, so we reset the Is_Overloaded flag to
9967 -- avoid any confusion when reanalyzing the node.
9969 Set_Is_Overloaded
(P
, False);
9970 Set_Is_Overloaded
(N
, False);
9971 Generate_Reference
(Entity
(P
), P
);
9975 Get_Next_Interp
(Index
, It
);
9978 -- If Prefix is a subprogram name, this reference freezes:
9980 -- If it is a type, there is nothing to resolve.
9981 -- If it is an object, complete its resolution.
9983 elsif Is_Overloadable
(Entity
(P
)) then
9985 -- Avoid insertion of freeze actions in spec expression mode
9987 if not In_Spec_Expression
then
9988 Freeze_Before
(N
, Entity
(P
));
9991 -- Nothing to do if prefix is a type name
9993 elsif Is_Type
(Entity
(P
)) then
9996 -- Otherwise non-overloaded other case, resolve the prefix
10002 -- Some further error checks
10004 Error_Msg_Name_1
:= Aname
;
10006 if not Is_Entity_Name
(P
) then
10009 elsif Is_Overloadable
(Entity
(P
))
10010 and then Is_Abstract_Subprogram
(Entity
(P
))
10012 Error_Msg_F
("prefix of % attribute cannot be abstract", P
);
10013 Set_Etype
(N
, Any_Type
);
10015 elsif Ekind
(Entity
(P
)) = E_Enumeration_Literal
then
10017 ("prefix of % attribute cannot be enumeration literal", P
);
10018 Set_Etype
(N
, Any_Type
);
10020 -- An attempt to take 'Access of a function that renames an
10021 -- enumeration literal. Issue a specialized error message.
10023 elsif Ekind
(Entity
(P
)) = E_Function
10024 and then Present
(Alias
(Entity
(P
)))
10025 and then Ekind
(Alias
(Entity
(P
))) = E_Enumeration_Literal
10028 ("prefix of % attribute cannot be function renaming "
10029 & "an enumeration literal", P
);
10030 Set_Etype
(N
, Any_Type
);
10032 elsif Convention
(Entity
(P
)) = Convention_Intrinsic
then
10033 Error_Msg_F
("prefix of % attribute cannot be intrinsic", P
);
10034 Set_Etype
(N
, Any_Type
);
10037 -- Assignments, return statements, components of aggregates,
10038 -- generic instantiations will require convention checks if
10039 -- the type is an access to subprogram. Given that there will
10040 -- also be accessibility checks on those, this is where the
10041 -- checks can eventually be centralized ???
10043 if Ekind_In
(Btyp
, E_Access_Subprogram_Type
,
10044 E_Anonymous_Access_Subprogram_Type
,
10045 E_Access_Protected_Subprogram_Type
,
10046 E_Anonymous_Access_Protected_Subprogram_Type
)
10048 -- Deal with convention mismatch
10050 if Convention
(Designated_Type
(Btyp
)) /=
10051 Convention
(Entity
(P
))
10054 ("subprogram & has wrong convention", P
, Entity
(P
));
10055 Error_Msg_Sloc
:= Sloc
(Btyp
);
10056 Error_Msg_FE
("\does not match & declared#", P
, Btyp
);
10058 if not Is_Itype
(Btyp
)
10059 and then not Has_Convention_Pragma
(Btyp
)
10062 ("\probable missing pragma Convention for &",
10067 Check_Subtype_Conformant
10068 (New_Id
=> Entity
(P
),
10069 Old_Id
=> Designated_Type
(Btyp
),
10073 if Attr_Id
= Attribute_Unchecked_Access
then
10074 Error_Msg_Name_1
:= Aname
;
10076 ("attribute% cannot be applied to a subprogram", P
);
10078 elsif Aname
= Name_Unrestricted_Access
then
10079 null; -- Nothing to check
10081 -- Check the static accessibility rule of 3.10.2(32).
10082 -- This rule also applies within the private part of an
10083 -- instantiation. This rule does not apply to anonymous
10084 -- access-to-subprogram types in access parameters.
10086 elsif Attr_Id
= Attribute_Access
10087 and then not In_Instance_Body
10089 (Ekind
(Btyp
) = E_Access_Subprogram_Type
10090 or else Is_Local_Anonymous_Access
(Btyp
))
10091 and then Subprogram_Access_Level
(Entity
(P
)) >
10092 Type_Access_Level
(Btyp
)
10095 ("subprogram must not be deeper than access type", P
);
10097 -- Check the restriction of 3.10.2(32) that disallows the
10098 -- access attribute within a generic body when the ultimate
10099 -- ancestor of the type of the attribute is declared outside
10100 -- of the generic unit and the subprogram is declared within
10101 -- that generic unit. This includes any such attribute that
10102 -- occurs within the body of a generic unit that is a child
10103 -- of the generic unit where the subprogram is declared.
10105 -- The rule also prohibits applying the attribute when the
10106 -- access type is a generic formal access type (since the
10107 -- level of the actual type is not known). This restriction
10108 -- does not apply when the attribute type is an anonymous
10109 -- access-to-subprogram type. Note that this check was
10110 -- revised by AI-229, because the original Ada 95 rule
10111 -- was too lax. The original rule only applied when the
10112 -- subprogram was declared within the body of the generic,
10113 -- which allowed the possibility of dangling references).
10114 -- The rule was also too strict in some cases, in that it
10115 -- didn't permit the access to be declared in the generic
10116 -- spec, whereas the revised rule does (as long as it's not
10119 -- There are a couple of subtleties of the test for applying
10120 -- the check that are worth noting. First, we only apply it
10121 -- when the levels of the subprogram and access type are the
10122 -- same (the case where the subprogram is statically deeper
10123 -- was applied above, and the case where the type is deeper
10124 -- is always safe). Second, we want the check to apply
10125 -- within nested generic bodies and generic child unit
10126 -- bodies, but not to apply to an attribute that appears in
10127 -- the generic unit's specification. This is done by testing
10128 -- that the attribute's innermost enclosing generic body is
10129 -- not the same as the innermost generic body enclosing the
10130 -- generic unit where the subprogram is declared (we don't
10131 -- want the check to apply when the access attribute is in
10132 -- the spec and there's some other generic body enclosing
10133 -- generic). Finally, there's no point applying the check
10134 -- when within an instance, because any violations will have
10135 -- been caught by the compilation of the generic unit.
10137 -- We relax this check in Relaxed_RM_Semantics mode for
10138 -- compatibility with legacy code for use by Ada source
10139 -- code analyzers (e.g. CodePeer).
10141 elsif Attr_Id
= Attribute_Access
10142 and then not Relaxed_RM_Semantics
10143 and then not In_Instance
10144 and then Present
(Enclosing_Generic_Unit
(Entity
(P
)))
10145 and then Present
(Enclosing_Generic_Body
(N
))
10146 and then Enclosing_Generic_Body
(N
) /=
10147 Enclosing_Generic_Body
10148 (Enclosing_Generic_Unit
(Entity
(P
)))
10149 and then Subprogram_Access_Level
(Entity
(P
)) =
10150 Type_Access_Level
(Btyp
)
10151 and then Ekind
(Btyp
) /=
10152 E_Anonymous_Access_Subprogram_Type
10153 and then Ekind
(Btyp
) /=
10154 E_Anonymous_Access_Protected_Subprogram_Type
10156 -- The attribute type's ultimate ancestor must be
10157 -- declared within the same generic unit as the
10158 -- subprogram is declared (including within another
10159 -- nested generic unit). The error message is
10160 -- specialized to say "ancestor" for the case where the
10161 -- access type is not its own ancestor, since saying
10162 -- simply "access type" would be very confusing.
10164 if not Declared_Within_Generic_Unit
10166 Enclosing_Generic_Unit
(Entity
(P
)))
10169 ("''Access attribute not allowed in generic body",
10172 if Root_Type
(Btyp
) = Btyp
then
10175 "access type & is declared outside " &
10176 "generic unit (RM 3.10.2(32))", N
, Btyp
);
10179 ("\because ancestor of " &
10180 "access type & is declared outside " &
10181 "generic unit (RM 3.10.2(32))", N
, Btyp
);
10185 ("\move ''Access to private part, or " &
10186 "(Ada 2005) use anonymous access type instead of &",
10189 -- If the ultimate ancestor of the attribute's type is
10190 -- a formal type, then the attribute is illegal because
10191 -- the actual type might be declared at a higher level.
10192 -- The error message is specialized to say "ancestor"
10193 -- for the case where the access type is not its own
10194 -- ancestor, since saying simply "access type" would be
10197 elsif Is_Generic_Type
(Root_Type
(Btyp
)) then
10198 if Root_Type
(Btyp
) = Btyp
then
10200 ("access type must not be a generic formal type",
10204 ("ancestor access type must not be a generic " &
10211 -- If this is a renaming, an inherited operation, or a
10212 -- subprogram instance, use the original entity. This may make
10213 -- the node type-inconsistent, so this transformation can only
10214 -- be done if the node will not be reanalyzed. In particular,
10215 -- if it is within a default expression, the transformation
10216 -- must be delayed until the default subprogram is created for
10217 -- it, when the enclosing subprogram is frozen.
10219 if Is_Entity_Name
(P
)
10220 and then Is_Overloadable
(Entity
(P
))
10221 and then Present
(Alias
(Entity
(P
)))
10222 and then Expander_Active
10225 New_Occurrence_Of
(Alias
(Entity
(P
)), Sloc
(P
)));
10228 elsif Nkind
(P
) = N_Selected_Component
10229 and then Is_Overloadable
(Entity
(Selector_Name
(P
)))
10231 -- Protected operation. If operation is overloaded, must
10232 -- disambiguate. Prefix that denotes protected object itself
10233 -- is resolved with its own type.
10235 if Attr_Id
= Attribute_Unchecked_Access
then
10236 Error_Msg_Name_1
:= Aname
;
10238 ("attribute% cannot be applied to protected operation", P
);
10241 Resolve
(Prefix
(P
));
10242 Generate_Reference
(Entity
(Selector_Name
(P
)), P
);
10244 -- Implement check implied by 3.10.2 (18.1/2) : F.all'access is
10245 -- statically illegal if F is an anonymous access to subprogram.
10247 elsif Nkind
(P
) = N_Explicit_Dereference
10248 and then Is_Entity_Name
(Prefix
(P
))
10249 and then Ekind
(Etype
(Entity
(Prefix
(P
)))) =
10250 E_Anonymous_Access_Subprogram_Type
10252 Error_Msg_N
("anonymous access to subprogram "
10253 & "has deeper accessibility than any master", P
);
10255 elsif Is_Overloaded
(P
) then
10257 -- Use the designated type of the context to disambiguate
10258 -- Note that this was not strictly conformant to Ada 95,
10259 -- but was the implementation adopted by most Ada 95 compilers.
10260 -- The use of the context type to resolve an Access attribute
10261 -- reference is now mandated in AI-235 for Ada 2005.
10264 Index
: Interp_Index
;
10268 Get_First_Interp
(P
, Index
, It
);
10269 while Present
(It
.Typ
) loop
10270 if Covers
(Designated_Type
(Typ
), It
.Typ
) then
10271 Resolve
(P
, It
.Typ
);
10275 Get_Next_Interp
(Index
, It
);
10282 -- X'Access is illegal if X denotes a constant and the access type
10283 -- is access-to-variable. Same for 'Unchecked_Access. The rule
10284 -- does not apply to 'Unrestricted_Access. If the reference is a
10285 -- default-initialized aggregate component for a self-referential
10286 -- type the reference is legal.
10288 if not (Ekind
(Btyp
) = E_Access_Subprogram_Type
10289 or else Ekind
(Btyp
) = E_Anonymous_Access_Subprogram_Type
10290 or else (Is_Record_Type
(Btyp
)
10292 Present
(Corresponding_Remote_Type
(Btyp
)))
10293 or else Ekind
(Btyp
) = E_Access_Protected_Subprogram_Type
10294 or else Ekind
(Btyp
)
10295 = E_Anonymous_Access_Protected_Subprogram_Type
10296 or else Is_Access_Constant
(Btyp
)
10297 or else Is_Variable
(P
)
10298 or else Attr_Id
= Attribute_Unrestricted_Access
)
10300 if Is_Entity_Name
(P
)
10301 and then Is_Type
(Entity
(P
))
10303 -- Legality of a self-reference through an access
10304 -- attribute has been verified in Analyze_Access_Attribute.
10308 elsif Comes_From_Source
(N
) then
10309 Error_Msg_F
("access-to-variable designates constant", P
);
10313 Des_Btyp
:= Designated_Type
(Btyp
);
10315 if Ada_Version
>= Ada_2005
10316 and then Is_Incomplete_Type
(Des_Btyp
)
10318 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
10319 -- imported entity, and the non-limited view is visible, make
10320 -- use of it. If it is an incomplete subtype, use the base type
10323 if From_Limited_With
(Des_Btyp
)
10324 and then Present
(Non_Limited_View
(Des_Btyp
))
10326 Des_Btyp
:= Non_Limited_View
(Des_Btyp
);
10328 elsif Ekind
(Des_Btyp
) = E_Incomplete_Subtype
then
10329 Des_Btyp
:= Etype
(Des_Btyp
);
10333 if (Attr_Id
= Attribute_Access
10335 Attr_Id
= Attribute_Unchecked_Access
)
10336 and then (Ekind
(Btyp
) = E_General_Access_Type
10337 or else Ekind
(Btyp
) = E_Anonymous_Access_Type
)
10339 -- Ada 2005 (AI-230): Check the accessibility of anonymous
10340 -- access types for stand-alone objects, record and array
10341 -- components, and return objects. For a component definition
10342 -- the level is the same of the enclosing composite type.
10344 if Ada_Version
>= Ada_2005
10345 and then (Is_Local_Anonymous_Access
(Btyp
)
10347 -- Handle cases where Btyp is the anonymous access
10348 -- type of an Ada 2012 stand-alone object.
10350 or else Nkind
(Associated_Node_For_Itype
(Btyp
)) =
10351 N_Object_Declaration
)
10353 Object_Access_Level
(P
) > Deepest_Type_Access_Level
(Btyp
)
10354 and then Attr_Id
= Attribute_Access
10356 -- In an instance, this is a runtime check, but one we know
10357 -- will fail, so generate an appropriate warning. As usual,
10358 -- this kind of warning is an error in SPARK mode.
10360 if In_Instance_Body
then
10361 Error_Msg_Warn
:= SPARK_Mode
/= On
;
10363 ("non-local pointer cannot point to local object<<", P
);
10364 Error_Msg_F
("\Program_Error [<<", P
);
10367 Make_Raise_Program_Error
(Loc
,
10368 Reason
=> PE_Accessibility_Check_Failed
));
10369 Set_Etype
(N
, Typ
);
10373 ("non-local pointer cannot point to local object", P
);
10377 if Is_Dependent_Component_Of_Mutable_Object
(P
) then
10379 ("illegal attribute for discriminant-dependent component",
10383 -- Check static matching rule of 3.10.2(27). Nominal subtype
10384 -- of the prefix must statically match the designated type.
10386 Nom_Subt
:= Etype
(P
);
10388 if Is_Constr_Subt_For_U_Nominal
(Nom_Subt
) then
10389 Nom_Subt
:= Base_Type
(Nom_Subt
);
10392 if Is_Tagged_Type
(Designated_Type
(Typ
)) then
10394 -- If the attribute is in the context of an access
10395 -- parameter, then the prefix is allowed to be of
10396 -- the class-wide type (by AI-127).
10398 if Ekind
(Typ
) = E_Anonymous_Access_Type
then
10399 if not Covers
(Designated_Type
(Typ
), Nom_Subt
)
10400 and then not Covers
(Nom_Subt
, Designated_Type
(Typ
))
10406 Desig
:= Designated_Type
(Typ
);
10408 if Is_Class_Wide_Type
(Desig
) then
10409 Desig
:= Etype
(Desig
);
10412 if Is_Anonymous_Tagged_Base
(Nom_Subt
, Desig
) then
10417 ("type of prefix: & not compatible",
10420 ("\with &, the expected designated type",
10421 P
, Designated_Type
(Typ
));
10426 elsif not Covers
(Designated_Type
(Typ
), Nom_Subt
)
10428 (not Is_Class_Wide_Type
(Designated_Type
(Typ
))
10429 and then Is_Class_Wide_Type
(Nom_Subt
))
10432 ("type of prefix: & is not covered", P
, Nom_Subt
);
10434 ("\by &, the expected designated type" &
10435 " (RM 3.10.2 (27))", P
, Designated_Type
(Typ
));
10438 if Is_Class_Wide_Type
(Designated_Type
(Typ
))
10439 and then Has_Discriminants
(Etype
(Designated_Type
(Typ
)))
10440 and then Is_Constrained
(Etype
(Designated_Type
(Typ
)))
10441 and then Designated_Type
(Typ
) /= Nom_Subt
10443 Apply_Discriminant_Check
10444 (N
, Etype
(Designated_Type
(Typ
)));
10447 -- Ada 2005 (AI-363): Require static matching when designated
10448 -- type has discriminants and a constrained partial view, since
10449 -- in general objects of such types are mutable, so we can't
10450 -- allow the access value to designate a constrained object
10451 -- (because access values must be assumed to designate mutable
10452 -- objects when designated type does not impose a constraint).
10454 elsif Subtypes_Statically_Match
(Des_Btyp
, Nom_Subt
) then
10457 elsif Has_Discriminants
(Designated_Type
(Typ
))
10458 and then not Is_Constrained
(Des_Btyp
)
10460 (Ada_Version
< Ada_2005
10462 not Object_Type_Has_Constrained_Partial_View
10463 (Typ
=> Designated_Type
(Base_Type
(Typ
)),
10464 Scop
=> Current_Scope
))
10470 ("object subtype must statically match "
10471 & "designated subtype", P
);
10473 if Is_Entity_Name
(P
)
10474 and then Is_Array_Type
(Designated_Type
(Typ
))
10477 D
: constant Node_Id
:= Declaration_Node
(Entity
(P
));
10480 ("aliased object has explicit bounds??", D
);
10482 ("\declare without bounds (and with explicit "
10483 & "initialization)??", D
);
10485 ("\for use with unconstrained access??", D
);
10490 -- Check the static accessibility rule of 3.10.2(28). Note that
10491 -- this check is not performed for the case of an anonymous
10492 -- access type, since the access attribute is always legal
10493 -- in such a context.
10495 if Attr_Id
/= Attribute_Unchecked_Access
10496 and then Ekind
(Btyp
) = E_General_Access_Type
10498 Object_Access_Level
(P
) > Deepest_Type_Access_Level
(Btyp
)
10500 Accessibility_Message
;
10505 if Ekind_In
(Btyp
, E_Access_Protected_Subprogram_Type
,
10506 E_Anonymous_Access_Protected_Subprogram_Type
)
10508 if Is_Entity_Name
(P
)
10509 and then not Is_Protected_Type
(Scope
(Entity
(P
)))
10511 Error_Msg_F
("context requires a protected subprogram", P
);
10513 -- Check accessibility of protected object against that of the
10514 -- access type, but only on user code, because the expander
10515 -- creates access references for handlers. If the context is an
10516 -- anonymous_access_to_protected, there are no accessibility
10517 -- checks either. Omit check entirely for Unrestricted_Access.
10519 elsif Object_Access_Level
(P
) > Deepest_Type_Access_Level
(Btyp
)
10520 and then Comes_From_Source
(N
)
10521 and then Ekind
(Btyp
) = E_Access_Protected_Subprogram_Type
10522 and then Attr_Id
/= Attribute_Unrestricted_Access
10524 Accessibility_Message
;
10527 -- AI05-0225: If the context is not an access to protected
10528 -- function, the prefix must be a variable, given that it may
10529 -- be used subsequently in a protected call.
10531 elsif Nkind
(P
) = N_Selected_Component
10532 and then not Is_Variable
(Prefix
(P
))
10533 and then Ekind
(Entity
(Selector_Name
(P
))) /= E_Function
10536 ("target object of access to protected procedure "
10537 & "must be variable", N
);
10539 elsif Is_Entity_Name
(P
) then
10540 Check_Internal_Protected_Use
(N
, Entity
(P
));
10543 elsif Ekind_In
(Btyp
, E_Access_Subprogram_Type
,
10544 E_Anonymous_Access_Subprogram_Type
)
10545 and then Ekind
(Etype
(N
)) = E_Access_Protected_Subprogram_Type
10547 Error_Msg_F
("context requires a non-protected subprogram", P
);
10550 -- The context cannot be a pool-specific type, but this is a
10551 -- legality rule, not a resolution rule, so it must be checked
10552 -- separately, after possibly disambiguation (see AI-245).
10554 if Ekind
(Btyp
) = E_Access_Type
10555 and then Attr_Id
/= Attribute_Unrestricted_Access
10557 Wrong_Type
(N
, Typ
);
10560 -- The context may be a constrained access type (however ill-
10561 -- advised such subtypes might be) so in order to generate a
10562 -- constraint check when needed set the type of the attribute
10563 -- reference to the base type of the context.
10565 Set_Etype
(N
, Btyp
);
10567 -- Check for incorrect atomic/volatile reference (RM C.6(12))
10569 if Attr_Id
/= Attribute_Unrestricted_Access
then
10570 if Is_Atomic_Object
(P
)
10571 and then not Is_Atomic
(Designated_Type
(Typ
))
10574 ("access to atomic object cannot yield access-to-" &
10575 "non-atomic type", P
);
10577 elsif Is_Volatile_Object
(P
)
10578 and then not Is_Volatile
(Designated_Type
(Typ
))
10581 ("access to volatile object cannot yield access-to-" &
10582 "non-volatile type", P
);
10586 -- Check for unrestricted access where expected type is a thin
10587 -- pointer to an unconstrained array.
10589 if Non_Aliased_Prefix
(N
)
10590 and then Has_Size_Clause
(Typ
)
10591 and then RM_Size
(Typ
) = System_Address_Size
10594 DT
: constant Entity_Id
:= Designated_Type
(Typ
);
10596 if Is_Array_Type
(DT
) and then not Is_Constrained
(DT
) then
10598 ("illegal use of Unrestricted_Access attribute", P
);
10600 ("\attempt to generate thin pointer to unaliased "
10606 -- Mark that address of entity is taken
10608 if Is_Entity_Name
(P
) then
10609 Set_Address_Taken
(Entity
(P
));
10612 -- Deal with possible elaboration check
10614 if Is_Entity_Name
(P
) and then Is_Subprogram
(Entity
(P
)) then
10616 Subp_Id
: constant Entity_Id
:= Entity
(P
);
10617 Scop
: constant Entity_Id
:= Scope
(Subp_Id
);
10618 Subp_Decl
: constant Node_Id
:=
10619 Unit_Declaration_Node
(Subp_Id
);
10620 Flag_Id
: Entity_Id
;
10621 Subp_Body
: Node_Id
;
10623 -- If the access has been taken and the body of the subprogram
10624 -- has not been see yet, indirect calls must be protected with
10625 -- elaboration checks. We have the proper elaboration machinery
10626 -- for subprograms declared in packages, but within a block or
10627 -- a subprogram the body will appear in the same declarative
10628 -- part, and we must insert a check in the eventual body itself
10629 -- using the elaboration flag that we generate now. The check
10630 -- is then inserted when the body is expanded. This processing
10631 -- is not needed for a stand alone expression function because
10632 -- the internally generated spec and body are always inserted
10633 -- as a pair in the same declarative list.
10637 and then Comes_From_Source
(Subp_Id
)
10638 and then Comes_From_Source
(N
)
10639 and then In_Open_Scopes
(Scop
)
10640 and then Ekind_In
(Scop
, E_Block
, E_Procedure
, E_Function
)
10641 and then not Has_Completion
(Subp_Id
)
10642 and then No
(Elaboration_Entity
(Subp_Id
))
10643 and then Nkind
(Subp_Decl
) = N_Subprogram_Declaration
10644 and then Nkind
(Original_Node
(Subp_Decl
)) /=
10645 N_Expression_Function
10647 -- Create elaboration variable for it
10649 Flag_Id
:= Make_Temporary
(Loc
, 'E');
10650 Set_Elaboration_Entity
(Subp_Id
, Flag_Id
);
10651 Set_Is_Frozen
(Flag_Id
);
10653 -- Insert declaration for flag after subprogram
10654 -- declaration. Note that attribute reference may
10655 -- appear within a nested scope.
10657 Insert_After_And_Analyze
(Subp_Decl
,
10658 Make_Object_Declaration
(Loc
,
10659 Defining_Identifier
=> Flag_Id
,
10660 Object_Definition
=>
10661 New_Occurrence_Of
(Standard_Short_Integer
, Loc
),
10663 Make_Integer_Literal
(Loc
, Uint_0
)));
10666 -- Taking the 'Access of an expression function freezes its
10667 -- expression (RM 13.14 10.3/3). This does not apply to an
10668 -- expression function that acts as a completion because the
10669 -- generated body is immediately analyzed and the expression
10670 -- is automatically frozen.
10672 if Is_Expression_Function
(Subp_Id
)
10673 and then Present
(Corresponding_Body
(Subp_Decl
))
10676 Unit_Declaration_Node
(Corresponding_Body
(Subp_Decl
));
10678 -- Analyze the body of the expression function to freeze
10679 -- the expression. This takes care of the case where the
10680 -- 'Access is part of dispatch table initialization and
10681 -- the generated body of the expression function has not
10682 -- been analyzed yet.
10684 if not Analyzed
(Subp_Body
) then
10685 Analyze
(Subp_Body
);
10690 end Access_Attribute
;
10696 -- Deal with resolving the type for Address attribute, overloading
10697 -- is not permitted here, since there is no context to resolve it.
10699 when Attribute_Address | Attribute_Code_Address
=>
10700 Address_Attribute
: begin
10702 -- To be safe, assume that if the address of a variable is taken,
10703 -- it may be modified via this address, so note modification.
10705 if Is_Variable
(P
) then
10706 Note_Possible_Modification
(P
, Sure
=> False);
10709 if Nkind
(P
) in N_Subexpr
10710 and then Is_Overloaded
(P
)
10712 Get_First_Interp
(P
, Index
, It
);
10713 Get_Next_Interp
(Index
, It
);
10715 if Present
(It
.Nam
) then
10716 Error_Msg_Name_1
:= Aname
;
10718 ("prefix of % attribute cannot be overloaded", P
);
10722 if not Is_Entity_Name
(P
)
10723 or else not Is_Overloadable
(Entity
(P
))
10725 if not Is_Task_Type
(Etype
(P
))
10726 or else Nkind
(P
) = N_Explicit_Dereference
10732 -- If this is the name of a derived subprogram, or that of a
10733 -- generic actual, the address is that of the original entity.
10735 if Is_Entity_Name
(P
)
10736 and then Is_Overloadable
(Entity
(P
))
10737 and then Present
(Alias
(Entity
(P
)))
10740 New_Occurrence_Of
(Alias
(Entity
(P
)), Sloc
(P
)));
10743 if Is_Entity_Name
(P
) then
10744 Set_Address_Taken
(Entity
(P
));
10747 if Nkind
(P
) = N_Slice
then
10749 -- Arr (X .. Y)'address is identical to Arr (X)'address,
10750 -- even if the array is packed and the slice itself is not
10751 -- addressable. Transform the prefix into an indexed component.
10753 -- Note that the transformation is safe only if we know that
10754 -- the slice is non-null. That is because a null slice can have
10755 -- an out of bounds index value.
10757 -- Right now, gigi blows up if given 'Address on a slice as a
10758 -- result of some incorrect freeze nodes generated by the front
10759 -- end, and this covers up that bug in one case, but the bug is
10760 -- likely still there in the cases not handled by this code ???
10762 -- It's not clear what 'Address *should* return for a null
10763 -- slice with out of bounds indexes, this might be worth an ARG
10766 -- One approach would be to do a length check unconditionally,
10767 -- and then do the transformation below unconditionally, but
10768 -- analyze with checks off, avoiding the problem of the out of
10769 -- bounds index. This approach would interpret the address of
10770 -- an out of bounds null slice as being the address where the
10771 -- array element would be if there was one, which is probably
10772 -- as reasonable an interpretation as any ???
10775 Loc
: constant Source_Ptr
:= Sloc
(P
);
10776 D
: constant Node_Id
:= Discrete_Range
(P
);
10780 if Is_Entity_Name
(D
)
10783 (Type_Low_Bound
(Entity
(D
)),
10784 Type_High_Bound
(Entity
(D
)))
10787 Make_Attribute_Reference
(Loc
,
10788 Prefix
=> (New_Occurrence_Of
(Entity
(D
), Loc
)),
10789 Attribute_Name
=> Name_First
);
10791 elsif Nkind
(D
) = N_Range
10792 and then Not_Null_Range
(Low_Bound
(D
), High_Bound
(D
))
10794 Lo
:= Low_Bound
(D
);
10800 if Present
(Lo
) then
10802 Make_Indexed_Component
(Loc
,
10803 Prefix
=> Relocate_Node
(Prefix
(P
)),
10804 Expressions
=> New_List
(Lo
)));
10806 Analyze_And_Resolve
(P
);
10810 end Address_Attribute
;
10816 -- Prefix of Body_Version attribute can be a subprogram name which
10817 -- must not be resolved, since this is not a call.
10819 when Attribute_Body_Version
=>
10826 -- Prefix of Caller attribute is an entry name which must not
10827 -- be resolved, since this is definitely not an entry call.
10829 when Attribute_Caller
=>
10836 -- Shares processing with Address attribute
10842 -- If the prefix of the Count attribute is an entry name it must not
10843 -- be resolved, since this is definitely not an entry call. However,
10844 -- if it is an element of an entry family, the index itself may
10845 -- have to be resolved because it can be a general expression.
10847 when Attribute_Count
=>
10848 if Nkind
(P
) = N_Indexed_Component
10849 and then Is_Entity_Name
(Prefix
(P
))
10852 Indx
: constant Node_Id
:= First
(Expressions
(P
));
10853 Fam
: constant Entity_Id
:= Entity
(Prefix
(P
));
10855 Resolve
(Indx
, Entry_Index_Type
(Fam
));
10856 Apply_Range_Check
(Indx
, Entry_Index_Type
(Fam
));
10864 -- Prefix of the Elaborated attribute is a subprogram name which
10865 -- must not be resolved, since this is definitely not a call. Note
10866 -- that it is a library unit, so it cannot be overloaded here.
10868 when Attribute_Elaborated
=>
10875 -- Prefix of Enabled attribute is a check name, which must be treated
10876 -- specially and not touched by Resolve.
10878 when Attribute_Enabled
=>
10885 -- Do not resolve the prefix of Loop_Entry, instead wait until the
10886 -- attribute has been expanded (see Expand_Loop_Entry_Attributes).
10887 -- The delay ensures that any generated checks or temporaries are
10888 -- inserted before the relocated prefix.
10890 when Attribute_Loop_Entry
=>
10893 --------------------
10894 -- Mechanism_Code --
10895 --------------------
10897 -- Prefix of the Mechanism_Code attribute is a function name
10898 -- which must not be resolved. Should we check for overloaded ???
10900 when Attribute_Mechanism_Code
=>
10907 -- Most processing is done in sem_dist, after determining the
10908 -- context type. Node is rewritten as a conversion to a runtime call.
10910 when Attribute_Partition_ID
=>
10911 Process_Partition_Id
(N
);
10918 when Attribute_Pool_Address
=>
10925 -- We replace the Range attribute node with a range expression whose
10926 -- bounds are the 'First and 'Last attributes applied to the same
10927 -- prefix. The reason that we do this transformation here instead of
10928 -- in the expander is that it simplifies other parts of the semantic
10929 -- analysis which assume that the Range has been replaced; thus it
10930 -- must be done even when in semantic-only mode (note that the RM
10931 -- specifically mentions this equivalence, we take care that the
10932 -- prefix is only evaluated once).
10934 when Attribute_Range
=> Range_Attribute
:
10941 if not Is_Entity_Name
(P
)
10942 or else not Is_Type
(Entity
(P
))
10947 Dims
:= Expressions
(N
);
10950 Make_Attribute_Reference
(Loc
,
10951 Prefix
=> Duplicate_Subexpr
(P
, Name_Req
=> True),
10952 Attribute_Name
=> Name_Last
,
10953 Expressions
=> Dims
);
10956 Make_Attribute_Reference
(Loc
,
10958 Attribute_Name
=> Name_First
,
10959 Expressions
=> (Dims
));
10961 -- Do not share the dimension indicator, if present. Even
10962 -- though it is a static constant, its source location
10963 -- may be modified when printing expanded code and node
10964 -- sharing will lead to chaos in Sprint.
10966 if Present
(Dims
) then
10967 Set_Expressions
(LB
,
10968 New_List
(New_Copy_Tree
(First
(Dims
))));
10971 -- If the original was marked as Must_Not_Freeze (see code
10972 -- in Sem_Ch3.Make_Index), then make sure the rewriting
10973 -- does not freeze either.
10975 if Must_Not_Freeze
(N
) then
10976 Set_Must_Not_Freeze
(HB
);
10977 Set_Must_Not_Freeze
(LB
);
10978 Set_Must_Not_Freeze
(Prefix
(HB
));
10979 Set_Must_Not_Freeze
(Prefix
(LB
));
10982 if Raises_Constraint_Error
(Prefix
(N
)) then
10984 -- Preserve Sloc of prefix in the new bounds, so that
10985 -- the posted warning can be removed if we are within
10986 -- unreachable code.
10988 Set_Sloc
(LB
, Sloc
(Prefix
(N
)));
10989 Set_Sloc
(HB
, Sloc
(Prefix
(N
)));
10992 Rewrite
(N
, Make_Range
(Loc
, LB
, HB
));
10993 Analyze_And_Resolve
(N
, Typ
);
10995 -- Ensure that the expanded range does not have side effects
10997 Force_Evaluation
(LB
);
10998 Force_Evaluation
(HB
);
11000 -- Normally after resolving attribute nodes, Eval_Attribute
11001 -- is called to do any possible static evaluation of the node.
11002 -- However, here since the Range attribute has just been
11003 -- transformed into a range expression it is no longer an
11004 -- attribute node and therefore the call needs to be avoided
11005 -- and is accomplished by simply returning from the procedure.
11008 end Range_Attribute
;
11014 -- We will only come here during the prescan of a spec expression
11015 -- containing a Result attribute. In that case the proper Etype has
11016 -- already been set, and nothing more needs to be done here.
11018 when Attribute_Result
=>
11025 -- Prefix must not be resolved in this case, since it is not a
11026 -- real entity reference. No action of any kind is require.
11028 when Attribute_UET_Address
=>
11031 ----------------------
11032 -- Unchecked_Access --
11033 ----------------------
11035 -- Processing is shared with Access
11037 -------------------------
11038 -- Unrestricted_Access --
11039 -------------------------
11041 -- Processing is shared with Access
11047 -- Resolve aggregate components in component associations
11049 when Attribute_Update
=>
11051 Aggr
: constant Node_Id
:= First
(Expressions
(N
));
11052 Typ
: constant Entity_Id
:= Etype
(Prefix
(N
));
11058 -- Set the Etype of the aggregate to that of the prefix, even
11059 -- though the aggregate may not be a proper representation of a
11060 -- value of the type (missing or duplicated associations, etc.)
11061 -- Complete resolution of the prefix. Note that in Ada 2012 it
11062 -- can be a qualified expression that is e.g. an aggregate.
11064 Set_Etype
(Aggr
, Typ
);
11065 Resolve
(Prefix
(N
), Typ
);
11067 -- For an array type, resolve expressions with the component
11068 -- type of the array, and apply constraint checks when needed.
11070 if Is_Array_Type
(Typ
) then
11071 Assoc
:= First
(Component_Associations
(Aggr
));
11072 while Present
(Assoc
) loop
11073 Expr
:= Expression
(Assoc
);
11074 Resolve
(Expr
, Component_Type
(Typ
));
11076 -- For scalar array components set Do_Range_Check when
11077 -- needed. Constraint checking on non-scalar components
11078 -- is done in Aggregate_Constraint_Checks, but only if
11079 -- full analysis is enabled. These flags are not set in
11080 -- the front-end in GnatProve mode.
11082 if Is_Scalar_Type
(Component_Type
(Typ
))
11083 and then not Is_OK_Static_Expression
(Expr
)
11085 if Is_Entity_Name
(Expr
)
11086 and then Etype
(Expr
) = Component_Type
(Typ
)
11091 Set_Do_Range_Check
(Expr
);
11095 -- The choices in the association are static constants,
11096 -- or static aggregates each of whose components belongs
11097 -- to the proper index type. However, they must also
11098 -- belong to the index subtype (s) of the prefix, which
11099 -- may be a subtype (e.g. given by a slice).
11101 -- Choices may also be identifiers with no staticness
11102 -- requirements, in which case they must resolve to the
11111 C
:= First
(Choices
(Assoc
));
11112 while Present
(C
) loop
11113 Indx
:= First_Index
(Etype
(Prefix
(N
)));
11115 if Nkind
(C
) /= N_Aggregate
then
11116 Analyze_And_Resolve
(C
, Etype
(Indx
));
11117 Apply_Constraint_Check
(C
, Etype
(Indx
));
11118 Check_Non_Static_Context
(C
);
11121 C_E
:= First
(Expressions
(C
));
11122 while Present
(C_E
) loop
11123 Analyze_And_Resolve
(C_E
, Etype
(Indx
));
11124 Apply_Constraint_Check
(C_E
, Etype
(Indx
));
11125 Check_Non_Static_Context
(C_E
);
11139 -- For a record type, use type of each component, which is
11140 -- recorded during analysis.
11143 Assoc
:= First
(Component_Associations
(Aggr
));
11144 while Present
(Assoc
) loop
11145 Comp
:= First
(Choices
(Assoc
));
11146 Expr
:= Expression
(Assoc
);
11148 if Nkind
(Comp
) /= N_Others_Choice
11149 and then not Error_Posted
(Comp
)
11151 Resolve
(Expr
, Etype
(Entity
(Comp
)));
11153 if Is_Scalar_Type
(Etype
(Entity
(Comp
)))
11154 and then not Is_OK_Static_Expression
(Expr
)
11156 Set_Do_Range_Check
(Expr
);
11169 -- Apply range check. Note that we did not do this during the
11170 -- analysis phase, since we wanted Eval_Attribute to have a
11171 -- chance at finding an illegal out of range value.
11173 when Attribute_Val
=>
11175 -- Note that we do our own Eval_Attribute call here rather than
11176 -- use the common one, because we need to do processing after
11177 -- the call, as per above comment.
11179 Eval_Attribute
(N
);
11181 -- Eval_Attribute may replace the node with a raise CE, or
11182 -- fold it to a constant. Obviously we only apply a scalar
11183 -- range check if this did not happen.
11185 if Nkind
(N
) = N_Attribute_Reference
11186 and then Attribute_Name
(N
) = Name_Val
11188 Apply_Scalar_Range_Check
(First
(Expressions
(N
)), Btyp
);
11197 -- Prefix of Version attribute can be a subprogram name which
11198 -- must not be resolved, since this is not a call.
11200 when Attribute_Version
=>
11203 ----------------------
11204 -- Other Attributes --
11205 ----------------------
11207 -- For other attributes, resolve prefix unless it is a type. If
11208 -- the attribute reference itself is a type name ('Base and 'Class)
11209 -- then this is only legal within a task or protected record.
11212 if not Is_Entity_Name
(P
) or else not Is_Type
(Entity
(P
)) then
11216 -- If the attribute reference itself is a type name ('Base,
11217 -- 'Class) then this is only legal within a task or protected
11218 -- record. What is this all about ???
11220 if Is_Entity_Name
(N
) and then Is_Type
(Entity
(N
)) then
11221 if Is_Concurrent_Type
(Entity
(N
))
11222 and then In_Open_Scopes
(Entity
(P
))
11227 ("invalid use of subtype name in expression or call", N
);
11231 -- For attributes whose argument may be a string, complete
11232 -- resolution of argument now. This avoids premature expansion
11233 -- (and the creation of transient scopes) before the attribute
11234 -- reference is resolved.
11237 when Attribute_Value
=>
11238 Resolve
(First
(Expressions
(N
)), Standard_String
);
11240 when Attribute_Wide_Value
=>
11241 Resolve
(First
(Expressions
(N
)), Standard_Wide_String
);
11243 when Attribute_Wide_Wide_Value
=>
11244 Resolve
(First
(Expressions
(N
)), Standard_Wide_Wide_String
);
11246 when others => null;
11249 -- If the prefix of the attribute is a class-wide type then it
11250 -- will be expanded into a dispatching call to a predefined
11251 -- primitive. Therefore we must check for potential violation
11252 -- of such restriction.
11254 if Is_Class_Wide_Type
(Etype
(P
)) then
11255 Check_Restriction
(No_Dispatching_Calls
, N
);
11259 -- Normally the Freezing is done by Resolve but sometimes the Prefix
11260 -- is not resolved, in which case the freezing must be done now.
11262 -- For an elaboration check on a subprogram, we do not freeze its type.
11263 -- It may be declared in an unrelated scope, in particular in the case
11264 -- of a generic function whose type may remain unelaborated.
11266 if Attr_Id
= Attribute_Elaborated
then
11270 Freeze_Expression
(P
);
11273 -- Finally perform static evaluation on the attribute reference
11275 Analyze_Dimension
(N
);
11276 Eval_Attribute
(N
);
11277 end Resolve_Attribute
;
11279 ------------------------
11280 -- Set_Boolean_Result --
11281 ------------------------
11283 procedure Set_Boolean_Result
(N
: Node_Id
; B
: Boolean) is
11284 Loc
: constant Source_Ptr
:= Sloc
(N
);
11287 Rewrite
(N
, New_Occurrence_Of
(Standard_True
, Loc
));
11289 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
11291 end Set_Boolean_Result
;
11293 --------------------------------
11294 -- Stream_Attribute_Available --
11295 --------------------------------
11297 function Stream_Attribute_Available
11299 Nam
: TSS_Name_Type
;
11300 Partial_View
: Node_Id
:= Empty
) return Boolean
11302 Etyp
: Entity_Id
:= Typ
;
11304 -- Start of processing for Stream_Attribute_Available
11307 -- We need some comments in this body ???
11309 if Has_Stream_Attribute_Definition
(Typ
, Nam
) then
11313 if Is_Class_Wide_Type
(Typ
) then
11314 return not Is_Limited_Type
(Typ
)
11315 or else Stream_Attribute_Available
(Etype
(Typ
), Nam
);
11318 if Nam
= TSS_Stream_Input
11319 and then Is_Abstract_Type
(Typ
)
11320 and then not Is_Class_Wide_Type
(Typ
)
11325 if not (Is_Limited_Type
(Typ
)
11326 or else (Present
(Partial_View
)
11327 and then Is_Limited_Type
(Partial_View
)))
11332 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
11334 if Nam
= TSS_Stream_Input
11335 and then Ada_Version
>= Ada_2005
11336 and then Stream_Attribute_Available
(Etyp
, TSS_Stream_Read
)
11340 elsif Nam
= TSS_Stream_Output
11341 and then Ada_Version
>= Ada_2005
11342 and then Stream_Attribute_Available
(Etyp
, TSS_Stream_Write
)
11347 -- Case of Read and Write: check for attribute definition clause that
11348 -- applies to an ancestor type.
11350 while Etype
(Etyp
) /= Etyp
loop
11351 Etyp
:= Etype
(Etyp
);
11353 if Has_Stream_Attribute_Definition
(Etyp
, Nam
) then
11358 if Ada_Version
< Ada_2005
then
11360 -- In Ada 95 mode, also consider a non-visible definition
11363 Btyp
: constant Entity_Id
:= Implementation_Base_Type
(Typ
);
11366 and then Stream_Attribute_Available
11367 (Btyp
, Nam
, Partial_View
=> Typ
);
11372 end Stream_Attribute_Available
;