1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Checks; use Checks;
31 with Elists; use Elists;
32 with Einfo; use Einfo;
33 with Errout; use Errout;
34 with Eval_Fat; use Eval_Fat;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Dist; use Exp_Dist;
37 with Exp_Util; use Exp_Util;
38 with Freeze; use Freeze;
39 with Itypes; use Itypes;
40 with Layout; use Layout;
42 with Lib.Xref; use Lib.Xref;
43 with Namet; use Namet;
44 with Nmake; use Nmake;
46 with Restrict; use Restrict;
47 with Rtsfind; use Rtsfind;
49 with Sem_Case; use Sem_Case;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch7; use Sem_Ch7;
53 with Sem_Ch8; use Sem_Ch8;
54 with Sem_Ch13; use Sem_Ch13;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Elim; use Sem_Elim;
58 with Sem_Eval; use Sem_Eval;
59 with Sem_Mech; use Sem_Mech;
60 with Sem_Res; use Sem_Res;
61 with Sem_Smem; use Sem_Smem;
62 with Sem_Type; use Sem_Type;
63 with Sem_Util; use Sem_Util;
64 with Stand; use Stand;
65 with Sinfo; use Sinfo;
66 with Snames; use Snames;
67 with Tbuild; use Tbuild;
68 with Ttypes; use Ttypes;
69 with Uintp; use Uintp;
70 with Urealp; use Urealp;
72 package body Sem_Ch3 is
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
78 procedure Build_Derived_Type
80 Parent_Type : Entity_Id;
81 Derived_Type : Entity_Id;
82 Is_Completion : Boolean;
83 Derive_Subps : Boolean := True);
84 -- Create and decorate a Derived_Type given the Parent_Type entity.
85 -- N is the N_Full_Type_Declaration node containing the derived type
86 -- definition. Parent_Type is the entity for the parent type in the derived
87 -- type definition and Derived_Type the actual derived type. Is_Completion
88 -- must be set to False if Derived_Type is the N_Defining_Identifier node
89 -- in N (ie Derived_Type = Defining_Identifier (N)). In this case N is not
90 -- the completion of a private type declaration. If Is_Completion is
91 -- set to True, N is the completion of a private type declaration and
92 -- Derived_Type is different from the defining identifier inside N (i.e.
93 -- Derived_Type /= Defining_Identifier (N)). Derive_Subps indicates whether
94 -- the parent subprograms should be derived. The only case where this
95 -- parameter is False is when Build_Derived_Type is recursively called to
96 -- process an implicit derived full type for a type derived from a private
97 -- type (in that case the subprograms must only be derived for the private
99 -- ??? These flags need a bit of re-examination and re-documentaion:
100 -- ??? are they both necessary (both seem related to the recursion)?
102 procedure Build_Derived_Access_Type
104 Parent_Type : Entity_Id;
105 Derived_Type : Entity_Id);
106 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
107 -- create an implicit base if the parent type is constrained or if the
108 -- subtype indication has a constraint.
110 procedure Build_Derived_Array_Type
112 Parent_Type : Entity_Id;
113 Derived_Type : Entity_Id);
114 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
115 -- create an implicit base if the parent type is constrained or if the
116 -- subtype indication has a constraint.
118 procedure Build_Derived_Concurrent_Type
120 Parent_Type : Entity_Id;
121 Derived_Type : Entity_Id);
122 -- Subsidiary procedure to Build_Derived_Type. For a derived task or pro-
123 -- tected type, inherit entries and protected subprograms, check legality
124 -- of discriminant constraints if any.
126 procedure Build_Derived_Enumeration_Type
128 Parent_Type : Entity_Id;
129 Derived_Type : Entity_Id);
130 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
131 -- type, we must create a new list of literals. Types derived from
132 -- Character and Wide_Character are special-cased.
134 procedure Build_Derived_Numeric_Type
136 Parent_Type : Entity_Id;
137 Derived_Type : Entity_Id);
138 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
139 -- an anonymous base type, and propagate constraint to subtype if needed.
141 procedure Build_Derived_Private_Type
143 Parent_Type : Entity_Id;
144 Derived_Type : Entity_Id;
145 Is_Completion : Boolean;
146 Derive_Subps : Boolean := True);
147 -- Substidiary procedure to Build_Derived_Type. This procedure is complex
148 -- because the parent may or may not have a completion, and the derivation
149 -- may itself be a completion.
151 procedure Build_Derived_Record_Type
153 Parent_Type : Entity_Id;
154 Derived_Type : Entity_Id;
155 Derive_Subps : Boolean := True);
156 -- Subsidiary procedure to Build_Derived_Type and
157 -- Analyze_Private_Extension_Declaration used for tagged and untagged
158 -- record types. All parameters are as in Build_Derived_Type except that
159 -- N, in addition to being an N_Full_Type_Declaration node, can also be an
160 -- N_Private_Extension_Declaration node. See the definition of this routine
161 -- for much more info. Derive_Subps indicates whether subprograms should
162 -- be derived from the parent type. The only case where Derive_Subps is
163 -- False is for an implicit derived full type for a type derived from a
164 -- private type (see Build_Derived_Type).
166 function Inherit_Components
168 Parent_Base : Entity_Id;
169 Derived_Base : Entity_Id;
171 Inherit_Discr : Boolean;
174 -- Called from Build_Derived_Record_Type to inherit the components of
175 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
176 -- For more information on derived types and component inheritance please
177 -- consult the comment above the body of Build_Derived_Record_Type.
179 -- N is the original derived type declaration.
180 -- Is_Tagged is set if we are dealing with tagged types.
181 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from
182 -- Parent_Base, otherwise no discriminants are inherited.
183 -- Discs gives the list of constraints that apply to Parent_Base in the
184 -- derived type declaration. If Discs is set to No_Elist, then we have the
185 -- following situation:
187 -- type Parent (D1..Dn : ..) is [tagged] record ...;
188 -- type Derived is new Parent [with ...];
190 -- which gets treated as
192 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
194 -- For untagged types the returned value is an association list:
195 -- (Old_Component => New_Component), where Old_Component is the Entity_Id
196 -- of a component in Parent_Base and New_Component is the Entity_Id of the
197 -- corresponding component in Derived_Base. For untagged records, this
198 -- association list is needed when copying the record declaration for the
199 -- derived base. In the tagged case the value returned is irrelevant.
201 procedure Build_Discriminal (Discrim : Entity_Id);
202 -- Create the discriminal corresponding to discriminant Discrim, that is
203 -- the parameter corresponding to Discrim to be used in initialization
204 -- procedures for the type where Discrim is a discriminant. Discriminals
205 -- are not used during semantic analysis, and are not fully defined
206 -- entities until expansion. Thus they are not given a scope until
207 -- intialization procedures are built.
209 function Build_Discriminant_Constraints
212 Derived_Def : Boolean := False)
214 -- Validate discriminant constraints, and return the list of the
215 -- constraints in order of discriminant declarations. T is the
216 -- discriminated unconstrained type. Def is the N_Subtype_Indication
217 -- node where the discriminants constraints for T are specified.
218 -- Derived_Def is True if we are building the discriminant constraints
219 -- in a derived type definition of the form "type D (...) is new T (xxx)".
220 -- In this case T is the parent type and Def is the constraint "(xxx)" on
221 -- T and this routine sets the Corresponding_Discriminant field of the
222 -- discriminants in the derived type D to point to the corresponding
223 -- discriminants in the parent type T.
225 procedure Build_Discriminated_Subtype
229 Related_Nod : Node_Id;
230 For_Access : Boolean := False);
231 -- Subsidiary procedure to Constrain_Discriminated_Type and to
232 -- Process_Incomplete_Dependents. Given
234 -- T (a possibly discriminated base type)
235 -- Def_Id (a very partially built subtype for T),
237 -- the call completes Def_Id to be the appropriate E_*_Subtype.
239 -- The Elist is the list of discriminant constraints if any (it is set to
240 -- No_Elist if T is not a discriminated type, and to an empty list if
241 -- T has discriminants but there are no discriminant constraints). The
242 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
243 -- The For_Access says whether or not this subtype is really constraining
244 -- an access type. That is its sole purpose is the designated type of an
245 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
246 -- is built to avoid freezing T when the access subtype is frozen.
248 function Build_Scalar_Bound
254 -- The bounds of a derived scalar type are conversions of the bounds of
255 -- the parent type. Optimize the representation if the bounds are literals.
256 -- Needs a more complete spec--what are the parameters exactly, and what
257 -- exactly is the returned value, and how is Bound affected???
259 procedure Build_Underlying_Full_View
263 -- If the completion of a private type is itself derived from a private
264 -- type, or if the full view of a private subtype is itself private, the
265 -- back-end has no way to compute the actual size of this type. We build
266 -- an internal subtype declaration of the proper parent type to convey
267 -- this information. This extra mechanism is needed because a full
268 -- view cannot itself have a full view (it would get clobbered during
271 procedure Check_Access_Discriminant_Requires_Limited
274 -- Check the restriction that the type to which an access discriminant
275 -- belongs must be a concurrent type or a descendant of a type with
276 -- the reserved word 'limited' in its declaration.
278 procedure Check_Delta_Expression (E : Node_Id);
279 -- Check that the expression represented by E is suitable for use as
280 -- a delta expression, i.e. it is of real type and is static.
282 procedure Check_Digits_Expression (E : Node_Id);
283 -- Check that the expression represented by E is suitable for use as
284 -- a digits expression, i.e. it is of integer type, positive and static.
286 procedure Check_Incomplete (T : Entity_Id);
287 -- Called to verify that an incomplete type is not used prematurely
289 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
290 -- Validate the initialization of an object declaration. T is the
291 -- required type, and Exp is the initialization expression.
293 procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id);
294 -- If T is the full declaration of an incomplete or private type, check
295 -- the conformance of the discriminants, otherwise process them.
297 procedure Check_Real_Bound (Bound : Node_Id);
298 -- Check given bound for being of real type and static. If not, post an
299 -- appropriate message, and rewrite the bound with the real literal zero.
301 procedure Constant_Redeclaration
305 -- Various checks on legality of full declaration of deferred constant.
306 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
307 -- node. The caller has not yet set any attributes of this entity.
309 procedure Convert_Scalar_Bounds
311 Parent_Type : Entity_Id;
312 Derived_Type : Entity_Id;
314 -- For derived scalar types, convert the bounds in the type definition
315 -- to the derived type, and complete their analysis.
317 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
318 -- Copies attributes from array base type T2 to array base type T1.
319 -- Copies only attributes that apply to base types, but not subtypes.
321 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
322 -- Copies attributes from array subtype T2 to array subtype T1. Copies
323 -- attributes that apply to both subtypes and base types.
325 procedure Create_Constrained_Components
329 Constraints : Elist_Id);
330 -- Build the list of entities for a constrained discriminated record
331 -- subtype. If a component depends on a discriminant, replace its subtype
332 -- using the discriminant values in the discriminant constraint.
333 -- Subt is the defining identifier for the subtype whose list of
334 -- constrained entities we will create. Decl_Node is the type declaration
335 -- node where we will attach all the itypes created. Typ is the base
336 -- discriminated type for the subtype Subt. Constraints is the list of
337 -- discriminant constraints for Typ.
339 function Constrain_Component_Type
340 (Compon_Type : Entity_Id;
341 Constrained_Typ : Entity_Id;
342 Related_Node : Node_Id;
344 Constraints : Elist_Id)
346 -- Given a discriminated base type Typ, a list of discriminant constraint
347 -- Constraints for Typ and the type of a component of Typ, Compon_Type,
348 -- create and return the type corresponding to Compon_type where all
349 -- discriminant references are replaced with the corresponding
350 -- constraint. If no discriminant references occurr in Compon_Typ then
351 -- return it as is. Constrained_Typ is the final constrained subtype to
352 -- which the constrained Compon_Type belongs. Related_Node is the node
353 -- where we will attach all the itypes created.
355 procedure Constrain_Access
356 (Def_Id : in out Entity_Id;
358 Related_Nod : Node_Id);
359 -- Apply a list of constraints to an access type. If Def_Id is empty,
360 -- it is an anonymous type created for a subtype indication. In that
361 -- case it is created in the procedure and attached to Related_Nod.
363 procedure Constrain_Array
364 (Def_Id : in out Entity_Id;
366 Related_Nod : Node_Id;
367 Related_Id : Entity_Id;
369 -- Apply a list of index constraints to an unconstrained array type. The
370 -- first parameter is the entity for the resulting subtype. A value of
371 -- Empty for Def_Id indicates that an implicit type must be created, but
372 -- creation is delayed (and must be done by this procedure) because other
373 -- subsidiary implicit types must be created first (which is why Def_Id
374 -- is an in/out parameter). Related_Nod gives the place where this type has
375 -- to be inserted in the tree. The Related_Id and Suffix parameters are
376 -- used to build the associated Implicit type name.
378 procedure Constrain_Concurrent
379 (Def_Id : in out Entity_Id;
381 Related_Nod : Node_Id;
382 Related_Id : Entity_Id;
384 -- Apply list of discriminant constraints to an unconstrained concurrent
387 -- SI is the N_Subtype_Indication node containing the constraint and
388 -- the unconstrained type to constrain.
390 -- Def_Id is the entity for the resulting constrained subtype. A
391 -- value of Empty for Def_Id indicates that an implicit type must be
392 -- created, but creation is delayed (and must be done by this procedure)
393 -- because other subsidiary implicit types must be created first (which
394 -- is why Def_Id is an in/out parameter).
396 -- Related_Nod gives the place where this type has to be inserted
399 -- The last two arguments are used to create its external name if needed.
401 function Constrain_Corresponding_Record
402 (Prot_Subt : Entity_Id;
403 Corr_Rec : Entity_Id;
404 Related_Nod : Node_Id;
405 Related_Id : Entity_Id)
407 -- When constraining a protected type or task type with discriminants,
408 -- constrain the corresponding record with the same discriminant values.
410 procedure Constrain_Decimal
413 Related_Nod : Node_Id);
414 -- Constrain a decimal fixed point type with a digits constraint and/or a
415 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
417 procedure Constrain_Discriminated_Type
420 Related_Nod : Node_Id;
421 For_Access : Boolean := False);
422 -- Process discriminant constraints of composite type. Verify that values
423 -- have been provided for all discriminants, that the original type is
424 -- unconstrained, and that the types of the supplied expressions match
425 -- the discriminant types. The first three parameters are like in routine
426 -- Constrain_Concurrent. See Build_Discrimated_Subtype for an explanation
429 procedure Constrain_Enumeration
432 Related_Nod : Node_Id);
433 -- Constrain an enumeration type with a range constraint. This is
434 -- identical to Constrain_Integer, but for the Ekind of the
435 -- resulting subtype.
437 procedure Constrain_Float
440 Related_Nod : Node_Id);
441 -- Constrain a floating point type with either a digits constraint
442 -- and/or a range constraint, building a E_Floating_Point_Subtype.
444 procedure Constrain_Index
447 Related_Nod : Node_Id;
448 Related_Id : Entity_Id;
451 -- Process an index constraint in a constrained array declaration.
452 -- The constraint can be a subtype name, or a range with or without
453 -- an explicit subtype mark. The index is the corresponding index of the
454 -- unconstrained array. The Related_Id and Suffix parameters are used to
455 -- build the associated Implicit type name.
457 procedure Constrain_Integer
460 Related_Nod : Node_Id);
461 -- Build subtype of a signed or modular integer type.
463 procedure Constrain_Ordinary_Fixed
466 Related_Nod : Node_Id);
467 -- Constrain an ordinary fixed point type with a range constraint, and
468 -- build an E_Ordinary_Fixed_Point_Subtype entity.
470 procedure Copy_And_Swap (Privat, Full : Entity_Id);
471 -- Copy the Privat entity into the entity of its full declaration
472 -- then swap the two entities in such a manner that the former private
473 -- type is now seen as a full type.
475 procedure Copy_Private_To_Full (Priv, Full : Entity_Id);
476 -- Initialize the full view declaration with the relevant fields
477 -- from the private view.
479 procedure Decimal_Fixed_Point_Type_Declaration
482 -- Create a new decimal fixed point type, and apply the constraint to
483 -- obtain a subtype of this new type.
485 procedure Complete_Private_Subtype
488 Full_Base : Entity_Id;
489 Related_Nod : Node_Id);
490 -- Complete the implicit full view of a private subtype by setting
491 -- the appropriate semantic fields. If the full view of the parent is
492 -- a record type, build constrained components of subtype.
494 procedure Derived_Standard_Character
496 Parent_Type : Entity_Id;
497 Derived_Type : Entity_Id);
498 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
499 -- derivations from types Standard.Character and Standard.Wide_Character.
501 procedure Derived_Type_Declaration
504 Is_Completion : Boolean);
505 -- Process a derived type declaration. This routine will invoke
506 -- Build_Derived_Type to process the actual derived type definition.
507 -- Parameters N and Is_Completion have the same meaning as in
508 -- Build_Derived_Type. T is the N_Defining_Identifier for the entity
509 -- defined in the N_Full_Type_Declaration node N, that is T is the
512 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
513 -- Given a subtype indication S (which is really an N_Subtype_Indication
514 -- node or a plain N_Identifier), find the type of the subtype mark.
516 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
517 -- Insert each literal in symbol table, as an overloadable identifier
518 -- Each enumeration type is mapped into a sequence of integers, and
519 -- each literal is defined as a constant with integer value. If any
520 -- of the literals are character literals, the type is a character
521 -- type, which means that strings are legal aggregates for arrays of
522 -- components of the type.
524 procedure Expand_Others_Choice
525 (Case_Table : Choice_Table_Type;
526 Others_Choice : Node_Id;
527 Choice_Type : Entity_Id);
528 -- In the case of a variant part of a record type that has an OTHERS
529 -- choice, this procedure expands the OTHERS into the actual choices
530 -- that it represents. This new list of choice nodes is attached to
531 -- the OTHERS node via the Others_Discrete_Choices field. The Case_Table
532 -- contains all choices that have been given explicitly in the variant.
534 function Find_Type_Of_Object
536 Related_Nod : Node_Id)
538 -- Get type entity for object referenced by Obj_Def, attaching the
539 -- implicit types generated to Related_Nod
541 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
542 -- Create a new float, and apply the constraint to obtain subtype of it
544 function Has_Range_Constraint (N : Node_Id) return Boolean;
545 -- Given an N_Subtype_Indication node N, return True if a range constraint
546 -- is present, either directly, or as part of a digits or delta constraint.
547 -- In addition, a digits constraint in the decimal case returns True, since
548 -- it establishes a default range if no explicit range is present.
550 function Is_Valid_Constraint_Kind
552 Constraint_Kind : Node_Kind)
554 -- Returns True if it is legal to apply the given kind of constraint
555 -- to the given kind of type (index constraint to an array type,
558 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
559 -- Create new modular type. Verify that modulus is in bounds and is
560 -- a power of two (implementation restriction).
562 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id);
563 -- Create an abbreviated declaration for an operator in order to
564 -- materialize minimally operators on derived types.
566 procedure Ordinary_Fixed_Point_Type_Declaration
569 -- Create a new ordinary fixed point type, and apply the constraint
570 -- to obtain subtype of it.
572 procedure Prepare_Private_Subtype_Completion
574 Related_Nod : Node_Id);
575 -- Id is a subtype of some private type. Creates the full declaration
576 -- associated with Id whenever possible, i.e. when the full declaration
577 -- of the base type is already known. Records each subtype into
578 -- Private_Dependents of the base type.
580 procedure Process_Incomplete_Dependents
584 -- Process all entities that depend on an incomplete type. There include
585 -- subtypes, subprogram types that mention the incomplete type in their
586 -- profiles, and subprogram with access parameters that designate the
589 -- Inc_T is the defining identifier of an incomplete type declaration, its
590 -- Ekind is E_Incomplete_Type.
592 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
594 -- Full_T is N's defining identifier.
596 -- Subtypes of incomplete types with discriminants are completed when the
597 -- parent type is. This is simpler than private subtypes, because they can
598 -- only appear in the same scope, and there is no need to exchange views.
599 -- Similarly, access_to_subprogram types may have a parameter or a return
600 -- type that is an incomplete type, and that must be replaced with the
603 -- If the full type is tagged, subprogram with access parameters that
604 -- designated the incomplete may be primitive operations of the full type,
605 -- and have to be processed accordingly.
607 procedure Process_Real_Range_Specification (Def : Node_Id);
608 -- Given the type definition for a real type, this procedure processes
609 -- and checks the real range specification of this type definition if
610 -- one is present. If errors are found, error messages are posted, and
611 -- the Real_Range_Specification of Def is reset to Empty.
613 procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id);
614 -- Process a record type declaration (for both untagged and tagged
615 -- records). Parameters T and N are exactly like in procedure
616 -- Derived_Type_Declaration, except that no flag Is_Completion is
617 -- needed for this routine.
619 procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id);
620 -- This routine is used to process the actual record type definition
621 -- (both for untagged and tagged records). Def is a record type
622 -- definition node. This procedure analyzes the components in this
623 -- record type definition. T is the entity for the enclosing record
624 -- type. It is provided so that its Has_Task flag can be set if any of
625 -- the component have Has_Task set.
627 procedure Set_Fixed_Range
632 -- Build a range node with the given bounds and set it as the Scalar_Range
633 -- of the given fixed-point type entity. Loc is the source location used
634 -- for the constructed range. See body for further details.
636 procedure Set_Scalar_Range_For_Subtype
640 Related_Nod : Node_Id);
641 -- This routine is used to set the scalar range field for a subtype
642 -- given Def_Id, the entity for the subtype, and R, the range expression
643 -- for the scalar range. Subt provides the parent subtype to be used
644 -- to analyze, resolve, and check the given range.
646 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
647 -- Create a new signed integer entity, and apply the constraint to obtain
648 -- the required first named subtype of this type.
650 -----------------------
651 -- Access_Definition --
652 -----------------------
654 function Access_Definition
655 (Related_Nod : Node_Id;
659 Anon_Type : constant Entity_Id :=
660 Create_Itype (E_Anonymous_Access_Type, Related_Nod,
661 Scope_Id => Scope (Current_Scope));
662 Desig_Type : Entity_Id;
665 if Is_Entry (Current_Scope)
666 and then Is_Task_Type (Etype (Scope (Current_Scope)))
668 Error_Msg_N ("task entries cannot have access parameters", N);
671 Find_Type (Subtype_Mark (N));
672 Desig_Type := Entity (Subtype_Mark (N));
674 Set_Directly_Designated_Type
675 (Anon_Type, Desig_Type);
676 Set_Etype (Anon_Type, Anon_Type);
677 Init_Size_Align (Anon_Type);
678 Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type));
680 -- The anonymous access type is as public as the discriminated type or
681 -- subprogram that defines it. It is imported (for back-end purposes)
682 -- if the designated type is.
684 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
685 Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type));
687 -- The context is either a subprogram declaration or an access
688 -- discriminant, in a private or a full type declaration. In
689 -- the case of a subprogram, If the designated type is incomplete,
690 -- the operation will be a primitive operation of the full type, to
691 -- be updated subsequently.
693 if Ekind (Desig_Type) = E_Incomplete_Type
694 and then Is_Overloadable (Current_Scope)
696 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
697 Set_Has_Delayed_Freeze (Current_Scope);
701 end Access_Definition;
703 -----------------------------------
704 -- Access_Subprogram_Declaration --
705 -----------------------------------
707 procedure Access_Subprogram_Declaration
711 Formals : constant List_Id := Parameter_Specifications (T_Def);
713 Desig_Type : constant Entity_Id :=
714 Create_Itype (E_Subprogram_Type, Parent (T_Def));
717 if Nkind (T_Def) = N_Access_Function_Definition then
718 Analyze (Subtype_Mark (T_Def));
719 Set_Etype (Desig_Type, Entity (Subtype_Mark (T_Def)));
721 Set_Etype (Desig_Type, Standard_Void_Type);
724 if Present (Formals) then
725 New_Scope (Desig_Type);
726 Process_Formals (Desig_Type, Formals, Parent (T_Def));
728 -- A bit of a kludge here, End_Scope requires that the parent
729 -- pointer be set to something reasonable, but Itypes don't
730 -- have parent pointers. So we set it and then unset it ???
731 -- If and when Itypes have proper parent pointers to their
732 -- declarations, this kludge can be removed.
734 Set_Parent (Desig_Type, T_Name);
736 Set_Parent (Desig_Type, Empty);
739 -- The return type and/or any parameter type may be incomplete. Mark
740 -- the subprogram_type as depending on the incomplete type, so that
741 -- it can be updated when the full type declaration is seen.
743 if Present (Formals) then
744 Formal := First_Formal (Desig_Type);
746 while Present (Formal) loop
748 if Ekind (Formal) /= E_In_Parameter
749 and then Nkind (T_Def) = N_Access_Function_Definition
751 Error_Msg_N ("functions can only have IN parameters", Formal);
754 if Ekind (Etype (Formal)) = E_Incomplete_Type then
755 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
756 Set_Has_Delayed_Freeze (Desig_Type);
759 Next_Formal (Formal);
763 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
764 and then not Has_Delayed_Freeze (Desig_Type)
766 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
767 Set_Has_Delayed_Freeze (Desig_Type);
770 Check_Delayed_Subprogram (Desig_Type);
772 if Protected_Present (T_Def) then
773 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
774 Set_Convention (Desig_Type, Convention_Protected);
776 Set_Ekind (T_Name, E_Access_Subprogram_Type);
779 Set_Etype (T_Name, T_Name);
780 Init_Size_Align (T_Name);
781 Set_Directly_Designated_Type (T_Name, Desig_Type);
783 Check_Restriction (No_Access_Subprograms, T_Def);
784 end Access_Subprogram_Declaration;
786 ----------------------------
787 -- Access_Type_Declaration --
788 ----------------------------
790 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
791 S : constant Node_Id := Subtype_Indication (Def);
792 P : constant Node_Id := Parent (Def);
795 -- Check for permissible use of incomplete type
797 if Nkind (S) /= N_Subtype_Indication then
800 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
801 Set_Directly_Designated_Type (T, Entity (S));
803 Set_Directly_Designated_Type (T,
804 Process_Subtype (S, P, T, 'P'));
808 Set_Directly_Designated_Type (T,
809 Process_Subtype (S, P, T, 'P'));
812 if All_Present (Def) or Constant_Present (Def) then
813 Set_Ekind (T, E_General_Access_Type);
815 Set_Ekind (T, E_Access_Type);
818 if Base_Type (Designated_Type (T)) = T then
819 Error_Msg_N ("access type cannot designate itself", S);
824 -- If the type has appeared already in a with_type clause, it is
825 -- frozen and the pointer size is already set. Else, initialize.
827 if not From_With_Type (T) then
831 Set_Is_Access_Constant (T, Constant_Present (Def));
833 -- If designated type is an imported tagged type, indicate that the
834 -- access type is also imported, and therefore restricted in its use.
835 -- The access type may already be imported, so keep setting otherwise.
837 if From_With_Type (Designated_Type (T)) then
838 Set_From_With_Type (T);
841 -- Note that Has_Task is always false, since the access type itself
842 -- is not a task type. See Einfo for more description on this point.
843 -- Exactly the same consideration applies to Has_Controlled_Component.
845 Set_Has_Task (T, False);
846 Set_Has_Controlled_Component (T, False);
847 end Access_Type_Declaration;
849 -----------------------------------
850 -- Analyze_Component_Declaration --
851 -----------------------------------
853 procedure Analyze_Component_Declaration (N : Node_Id) is
854 Id : constant Entity_Id := Defining_Identifier (N);
859 Generate_Definition (Id);
861 T := Find_Type_Of_Object (Subtype_Indication (N), N);
863 -- If the component declaration includes a default expression, then we
864 -- check that the component is not of a limited type (RM 3.7(5)),
865 -- and do the special preanalysis of the expression (see section on
866 -- "Handling of Default Expressions" in the spec of package Sem).
868 if Present (Expression (N)) then
869 Analyze_Default_Expression (Expression (N), T);
870 Check_Initialization (T, Expression (N));
873 -- The parent type may be a private view with unknown discriminants,
874 -- and thus unconstrained. Regular components must be constrained.
876 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
878 ("unconstrained subtype in component declaration",
879 Subtype_Indication (N));
881 -- Components cannot be abstract, except for the special case of
882 -- the _Parent field (case of extending an abstract tagged type)
884 elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then
885 Error_Msg_N ("type of a component cannot be abstract", N);
889 Set_Is_Aliased (Id, Aliased_Present (N));
891 -- If the this component is private (or depends on a private type),
892 -- flag the record type to indicate that some operations are not
895 P := Private_Component (T);
898 -- Check for circular definitions.
901 Set_Etype (Id, Any_Type);
903 -- There is a gap in the visibility of operations only if the
904 -- component type is not defined in the scope of the record type.
906 elsif Scope (P) = Scope (Current_Scope) then
909 elsif Is_Limited_Type (P) then
910 Set_Is_Limited_Composite (Current_Scope);
913 Set_Is_Private_Composite (Current_Scope);
918 and then Is_Limited_Type (T)
919 and then Chars (Id) /= Name_uParent
920 and then Is_Tagged_Type (Current_Scope)
922 if Is_Derived_Type (Current_Scope)
923 and then not Is_Limited_Record (Root_Type (Current_Scope))
926 ("extension of nonlimited type cannot have limited components",
928 Set_Etype (Id, Any_Type);
929 Set_Is_Limited_Composite (Current_Scope, False);
931 elsif not Is_Derived_Type (Current_Scope)
932 and then not Is_Limited_Record (Current_Scope)
934 Error_Msg_N ("nonlimited type cannot have limited components", N);
935 Set_Etype (Id, Any_Type);
936 Set_Is_Limited_Composite (Current_Scope, False);
940 Set_Original_Record_Component (Id, Id);
941 end Analyze_Component_Declaration;
943 --------------------------
944 -- Analyze_Declarations --
945 --------------------------
947 procedure Analyze_Declarations (L : List_Id) is
950 Freeze_From : Entity_Id := Empty;
953 -- Adjust D not to include implicit label declarations, since these
954 -- have strange Sloc values that result in elaboration check problems.
956 procedure Adjust_D is
958 while Present (Prev (D))
959 and then Nkind (D) = N_Implicit_Label_Declaration
965 -- Start of processing for Analyze_Declarations
969 while Present (D) loop
971 -- Complete analysis of declaration
974 Next_Node := Next (D);
976 if No (Freeze_From) then
977 Freeze_From := First_Entity (Current_Scope);
980 -- At the end of a declarative part, freeze remaining entities
981 -- declared in it. The end of the visible declarations of a
982 -- package specification is not the end of a declarative part
983 -- if private declarations are present. The end of a package
984 -- declaration is a freezing point only if it a library package.
985 -- A task definition or protected type definition is not a freeze
986 -- point either. Finally, we do not freeze entities in generic
987 -- scopes, because there is no code generated for them and freeze
988 -- nodes will be generated for the instance.
990 -- The end of a package instantiation is not a freeze point, but
991 -- for now we make it one, because the generic body is inserted
992 -- (currently) immediately after. Generic instantiations will not
993 -- be a freeze point once delayed freezing of bodies is implemented.
994 -- (This is needed in any case for early instantiations ???).
996 if No (Next_Node) then
997 if Nkind (Parent (L)) = N_Component_List
998 or else Nkind (Parent (L)) = N_Task_Definition
999 or else Nkind (Parent (L)) = N_Protected_Definition
1003 elsif Nkind (Parent (L)) /= N_Package_Specification then
1005 if Nkind (Parent (L)) = N_Package_Body then
1006 Freeze_From := First_Entity (Current_Scope);
1010 Freeze_All (Freeze_From, D);
1011 Freeze_From := Last_Entity (Current_Scope);
1013 elsif Scope (Current_Scope) /= Standard_Standard
1014 and then not Is_Child_Unit (Current_Scope)
1015 and then No (Generic_Parent (Parent (L)))
1019 elsif L /= Visible_Declarations (Parent (L))
1020 or else No (Private_Declarations (Parent (L)))
1021 or else Is_Empty_List (Private_Declarations (Parent (L)))
1024 Freeze_All (Freeze_From, D);
1025 Freeze_From := Last_Entity (Current_Scope);
1028 -- If next node is a body then freeze all types before the body.
1029 -- An exception occurs for expander generated bodies, which can
1030 -- be recognized by their already being analyzed. The expander
1031 -- ensures that all types needed by these bodies have been frozen
1032 -- but it is not necessary to freeze all types (and would be wrong
1033 -- since it would not correspond to an RM defined freeze point).
1035 elsif not Analyzed (Next_Node)
1036 and then (Nkind (Next_Node) = N_Subprogram_Body
1037 or else Nkind (Next_Node) = N_Entry_Body
1038 or else Nkind (Next_Node) = N_Package_Body
1039 or else Nkind (Next_Node) = N_Protected_Body
1040 or else Nkind (Next_Node) = N_Task_Body
1041 or else Nkind (Next_Node) in N_Body_Stub)
1044 Freeze_All (Freeze_From, D);
1045 Freeze_From := Last_Entity (Current_Scope);
1051 end Analyze_Declarations;
1053 --------------------------------
1054 -- Analyze_Default_Expression --
1055 --------------------------------
1057 procedure Analyze_Default_Expression (N : Node_Id; T : Entity_Id) is
1058 Save_In_Default_Expression : constant Boolean := In_Default_Expression;
1061 In_Default_Expression := True;
1062 Pre_Analyze_And_Resolve (N, T);
1063 In_Default_Expression := Save_In_Default_Expression;
1064 end Analyze_Default_Expression;
1066 ----------------------------------
1067 -- Analyze_Incomplete_Type_Decl --
1068 ----------------------------------
1070 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
1071 F : constant Boolean := Is_Pure (Current_Scope);
1075 Generate_Definition (Defining_Identifier (N));
1077 -- Process an incomplete declaration. The identifier must not have been
1078 -- declared already in the scope. However, an incomplete declaration may
1079 -- appear in the private part of a package, for a private type that has
1080 -- already been declared.
1082 -- In this case, the discriminants (if any) must match.
1084 T := Find_Type_Name (N);
1086 Set_Ekind (T, E_Incomplete_Type);
1087 Init_Size_Align (T);
1088 Set_Is_First_Subtype (T, True);
1092 Set_Girder_Constraint (T, No_Elist);
1094 if Present (Discriminant_Specifications (N)) then
1095 Process_Discriminants (N);
1100 -- If the type has discriminants, non-trivial subtypes may be
1101 -- be declared before the full view of the type. The full views
1102 -- of those subtypes will be built after the full view of the type.
1104 Set_Private_Dependents (T, New_Elmt_List);
1106 end Analyze_Incomplete_Type_Decl;
1108 -----------------------------
1109 -- Analyze_Itype_Reference --
1110 -----------------------------
1112 -- Nothing to do. This node is placed in the tree only for the benefit
1113 -- of Gigi processing, and has no effect on the semantic processing.
1115 procedure Analyze_Itype_Reference (N : Node_Id) is
1117 pragma Assert (Is_Itype (Itype (N)));
1119 end Analyze_Itype_Reference;
1121 --------------------------------
1122 -- Analyze_Number_Declaration --
1123 --------------------------------
1125 procedure Analyze_Number_Declaration (N : Node_Id) is
1126 Id : constant Entity_Id := Defining_Identifier (N);
1127 E : constant Node_Id := Expression (N);
1129 Index : Interp_Index;
1133 Generate_Definition (Id);
1136 -- This is an optimization of a common case of an integer literal
1138 if Nkind (E) = N_Integer_Literal then
1139 Set_Is_Static_Expression (E, True);
1140 Set_Etype (E, Universal_Integer);
1142 Set_Etype (Id, Universal_Integer);
1143 Set_Ekind (Id, E_Named_Integer);
1144 Set_Is_Frozen (Id, True);
1148 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1150 -- Process expression, replacing error by integer zero, to avoid
1151 -- cascaded errors or aborts further along in the processing
1153 -- Replace Error by integer zero, which seems least likely to
1154 -- cause cascaded errors.
1157 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
1158 Set_Error_Posted (E);
1163 -- Verify that the expression is static and numeric. If
1164 -- the expression is overloaded, we apply the preference
1165 -- rule that favors root numeric types.
1167 if not Is_Overloaded (E) then
1172 Get_First_Interp (E, Index, It);
1174 while Present (It.Typ) loop
1175 if (Is_Integer_Type (It.Typ)
1176 or else Is_Real_Type (It.Typ))
1177 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
1179 if T = Any_Type then
1182 elsif It.Typ = Universal_Real
1183 or else It.Typ = Universal_Integer
1185 -- Choose universal interpretation over any other.
1192 Get_Next_Interp (Index, It);
1196 if Is_Integer_Type (T) then
1198 Set_Etype (Id, Universal_Integer);
1199 Set_Ekind (Id, E_Named_Integer);
1201 elsif Is_Real_Type (T) then
1203 -- Because the real value is converted to universal_real, this
1204 -- is a legal context for a universal fixed expression.
1206 if T = Universal_Fixed then
1208 Loc : constant Source_Ptr := Sloc (N);
1209 Conv : constant Node_Id := Make_Type_Conversion (Loc,
1211 New_Occurrence_Of (Universal_Real, Loc),
1212 Expression => Relocate_Node (E));
1219 elsif T = Any_Fixed then
1220 Error_Msg_N ("illegal context for mixed mode operation", E);
1222 -- Expression is of the form : universal_fixed * integer.
1223 -- Try to resolve as universal_real.
1225 T := Universal_Real;
1230 Set_Etype (Id, Universal_Real);
1231 Set_Ekind (Id, E_Named_Real);
1234 Wrong_Type (E, Any_Numeric);
1237 Set_Ekind (Id, E_Constant);
1238 Set_Not_Source_Assigned (Id, True);
1239 Set_Is_True_Constant (Id, True);
1243 if Nkind (E) = N_Integer_Literal
1244 or else Nkind (E) = N_Real_Literal
1246 Set_Etype (E, Etype (Id));
1249 if not Is_OK_Static_Expression (E) then
1250 Error_Msg_N ("non-static expression used in number declaration", E);
1251 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
1252 Set_Etype (E, Any_Type);
1255 end Analyze_Number_Declaration;
1257 --------------------------------
1258 -- Analyze_Object_Declaration --
1259 --------------------------------
1261 procedure Analyze_Object_Declaration (N : Node_Id) is
1262 Loc : constant Source_Ptr := Sloc (N);
1263 Id : constant Entity_Id := Defining_Identifier (N);
1267 E : Node_Id := Expression (N);
1268 -- E is set to Expression (N) throughout this routine. When
1269 -- Expression (N) is modified, E is changed accordingly.
1271 Prev_Entity : Entity_Id := Empty;
1273 function Build_Default_Subtype return Entity_Id;
1274 -- If the object is limited or aliased, and if the type is unconstrained
1275 -- and there is no expression, the discriminants cannot be modified and
1276 -- the subtype of the object is constrained by the defaults, so it is
1277 -- worthile building the corresponding subtype.
1279 ---------------------------
1280 -- Build_Default_Subtype --
1281 ---------------------------
1283 function Build_Default_Subtype return Entity_Id is
1285 Constraints : List_Id := New_List;
1290 Disc := First_Discriminant (T);
1292 if No (Discriminant_Default_Value (Disc)) then
1293 return T; -- previous error.
1296 Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
1297 while Present (Disc) loop
1300 Discriminant_Default_Value (Disc)), Constraints);
1301 Next_Discriminant (Disc);
1305 Make_Subtype_Declaration (Loc,
1306 Defining_Identifier => Act,
1307 Subtype_Indication =>
1308 Make_Subtype_Indication (Loc,
1309 Subtype_Mark => New_Occurrence_Of (T, Loc),
1311 Make_Index_Or_Discriminant_Constraint
1312 (Loc, Constraints)));
1314 Insert_Before (N, Decl);
1317 end Build_Default_Subtype;
1319 -- Start of processing for Analyze_Object_Declaration
1322 -- There are three kinds of implicit types generated by an
1323 -- object declaration:
1325 -- 1. Those for generated by the original Object Definition
1327 -- 2. Those generated by the Expression
1329 -- 3. Those used to constrained the Object Definition with the
1330 -- expression constraints when it is unconstrained
1332 -- They must be generated in this order to avoid order of elaboration
1333 -- issues. Thus the first step (after entering the name) is to analyze
1334 -- the object definition.
1336 if Constant_Present (N) then
1337 Prev_Entity := Current_Entity_In_Scope (Id);
1339 -- If homograph is an implicit subprogram, it is overridden by the
1340 -- current declaration.
1342 if Present (Prev_Entity)
1343 and then Is_Overloadable (Prev_Entity)
1344 and then Is_Inherited_Operation (Prev_Entity)
1346 Prev_Entity := Empty;
1350 if Present (Prev_Entity) then
1351 Constant_Redeclaration (Id, N, T);
1353 Generate_Reference (Prev_Entity, Id, 'c');
1355 -- If in main unit, set as referenced, so we do not complain about
1356 -- the full declaration being an unreferenced entity.
1358 if In_Extended_Main_Source_Unit (Id) then
1359 Set_Referenced (Id);
1362 if Error_Posted (N) then
1363 -- Type mismatch or illegal redeclaration, Do not analyze
1364 -- expression to avoid cascaded errors.
1366 T := Find_Type_Of_Object (Object_Definition (N), N);
1368 Set_Ekind (Id, E_Variable);
1372 -- In the normal case, enter identifier at the start to catch
1373 -- premature usage in the initialization expression.
1376 Generate_Definition (Id);
1379 T := Find_Type_Of_Object (Object_Definition (N), N);
1381 if Error_Posted (Id) then
1383 Set_Ekind (Id, E_Variable);
1388 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1390 -- If deferred constant, make sure context is appropriate. We detect
1391 -- a deferred constant as a constant declaration with no expression.
1393 if Constant_Present (N)
1396 if not Is_Package (Current_Scope)
1397 or else In_Private_Part (Current_Scope)
1400 ("invalid context for deferred constant declaration", N);
1401 Set_Constant_Present (N, False);
1403 -- In Ada 83, deferred constant must be of private type
1405 elsif not Is_Private_Type (T) then
1406 if Ada_83 and then Comes_From_Source (N) then
1408 ("(Ada 83) deferred constant must be private type", N);
1412 -- If not a deferred constant, then object declaration freezes its type
1415 Check_Fully_Declared (T, N);
1416 Freeze_Before (N, T);
1419 -- If the object was created by a constrained array definition, then
1420 -- set the link in both the anonymous base type and anonymous subtype
1421 -- that are built to represent the array type to point to the object.
1423 if Nkind (Object_Definition (Declaration_Node (Id))) =
1424 N_Constrained_Array_Definition
1426 Set_Related_Array_Object (T, Id);
1427 Set_Related_Array_Object (Base_Type (T), Id);
1430 -- Special checks for protected objects not at library level
1432 if Is_Protected_Type (T)
1433 and then not Is_Library_Level_Entity (Id)
1435 Check_Restriction (No_Local_Protected_Objects, Id);
1437 -- Protected objects with interrupt handlers must be at library level
1439 if Has_Interrupt_Handler (T) then
1441 ("interrupt object can only be declared at library level", Id);
1445 -- The actual subtype of the object is the nominal subtype, unless
1446 -- the nominal one is unconstrained and obtained from the expression.
1450 -- Process initialization expression if present and not in error
1452 if Present (E) and then E /= Error then
1455 if not Assignment_OK (N) then
1456 Check_Initialization (T, E);
1461 -- Check for library level object that will require implicit
1464 if Is_Array_Type (T)
1465 and then not Size_Known_At_Compile_Time (T)
1466 and then Is_Library_Level_Entity (Id)
1468 -- String literals are always allowed
1470 if T = Standard_String
1471 and then Nkind (E) = N_String_Literal
1475 -- Otherwise we do not allow this since it may cause an
1476 -- implicit heap allocation.
1480 (No_Implicit_Heap_Allocations, Object_Definition (N));
1484 -- Check incorrect use of dynamically tagged expressions. Note
1485 -- the use of Is_Tagged_Type (T) which seems redundant but is in
1486 -- fact important to avoid spurious errors due to expanded code
1487 -- for dispatching functions over an anonymous access type
1489 if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
1490 and then Is_Tagged_Type (T)
1491 and then not Is_Class_Wide_Type (T)
1493 Error_Msg_N ("dynamically tagged expression not allowed!", E);
1496 Apply_Scalar_Range_Check (E, T);
1497 Apply_Static_Length_Check (E, T);
1500 -- Abstract type is never permitted for a variable or constant.
1501 -- Note: we inhibit this check for objects that do not come from
1502 -- source because there is at least one case (the expansion of
1503 -- x'class'input where x is abstract) where we legitimately
1504 -- generate an abstract object.
1506 if Is_Abstract (T) and then Comes_From_Source (N) then
1507 Error_Msg_N ("type of object cannot be abstract",
1508 Object_Definition (N));
1509 if Is_CPP_Class (T) then
1510 Error_Msg_NE ("\} may need a cpp_constructor",
1511 Object_Definition (N), T);
1514 -- Case of unconstrained type
1516 elsif Is_Indefinite_Subtype (T) then
1518 -- Nothing to do in deferred constant case
1520 if Constant_Present (N) and then No (E) then
1523 -- Case of no initialization present
1526 if No_Initialization (N) then
1529 elsif Is_Class_Wide_Type (T) then
1531 ("initialization required in class-wide declaration ", N);
1535 ("unconstrained subtype not allowed (need initialization)",
1536 Object_Definition (N));
1539 -- Case of initialization present but in error. Set initial
1540 -- expression as absent (but do not make above complaints)
1542 elsif E = Error then
1543 Set_Expression (N, Empty);
1546 -- Case of initialization present
1549 -- Not allowed in Ada 83
1551 if not Constant_Present (N) then
1553 and then Comes_From_Source (Object_Definition (N))
1556 ("(Ada 83) unconstrained variable not allowed",
1557 Object_Definition (N));
1561 -- Now we constrain the variable from the initializing expression
1563 -- If the expression is an aggregate, it has been expanded into
1564 -- individual assignments. Retrieve the actual type from the
1565 -- expanded construct.
1567 if Is_Array_Type (T)
1568 and then No_Initialization (N)
1569 and then Nkind (Original_Node (E)) = N_Aggregate
1574 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
1575 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
1578 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
1580 if Aliased_Present (N) then
1581 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1584 Freeze_Before (N, Act_T);
1585 Freeze_Before (N, T);
1588 elsif Is_Array_Type (T)
1589 and then No_Initialization (N)
1590 and then Nkind (Original_Node (E)) = N_Aggregate
1592 if not Is_Entity_Name (Object_Definition (N)) then
1595 if Aliased_Present (N) then
1596 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1600 -- When the given object definition and the aggregate are specified
1601 -- independently, and their lengths might differ do a length check.
1602 -- This cannot happen if the aggregate is of the form (others =>...)
1604 if not Is_Constrained (T) then
1607 elsif Nkind (E) = N_Raise_Constraint_Error then
1608 -- Aggregate is statically illegal. Place back in declaration.
1609 Set_Expression (N, E);
1610 Set_No_Initialization (N, False);
1612 elsif T = Etype (E) then
1615 elsif Nkind (E) = N_Aggregate
1616 and then Present (Component_Associations (E))
1617 and then Present (Choices (First (Component_Associations (E))))
1618 and then Nkind (First
1619 (Choices (First (Component_Associations (E))))) = N_Others_Choice
1624 Apply_Length_Check (E, T);
1627 elsif (Is_Limited_Record (T)
1628 or else Is_Concurrent_Type (T))
1629 and then not Is_Constrained (T)
1630 and then Has_Discriminants (T)
1632 Act_T := Build_Default_Subtype;
1633 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
1635 elsif not Is_Constrained (T)
1636 and then Has_Discriminants (T)
1637 and then Constant_Present (N)
1638 and then Nkind (E) = N_Function_Call
1640 -- The back-end has problems with constants of a discriminated type
1641 -- with defaults, if the initial value is a function call. We
1642 -- generate an intermediate temporary for the result of the call.
1643 -- It is unclear why this should make it acceptable to gcc. ???
1645 Remove_Side_Effects (E);
1648 if T = Standard_Wide_Character
1649 or else Root_Type (T) = Standard_Wide_String
1651 Check_Restriction (No_Wide_Characters, Object_Definition (N));
1654 -- Now establish the proper kind and type of the object
1656 if Constant_Present (N) then
1657 Set_Ekind (Id, E_Constant);
1658 Set_Not_Source_Assigned (Id, True);
1659 Set_Is_True_Constant (Id, True);
1662 Set_Ekind (Id, E_Variable);
1664 -- A variable is set as shared passive if it appears in a shared
1665 -- passive package, and is at the outer level. This is not done
1666 -- for entities generated during expansion, because those are
1667 -- always manipulated locally.
1669 if Is_Shared_Passive (Current_Scope)
1670 and then Is_Library_Level_Entity (Id)
1671 and then Comes_From_Source (Id)
1673 Set_Is_Shared_Passive (Id);
1674 Check_Shared_Var (Id, T, N);
1677 -- If an initializing expression is present, then the variable
1678 -- is potentially a true constant if no further assignments are
1679 -- present. The code generator can use this for optimization.
1680 -- The flag will be reset if there are any assignments. We only
1681 -- set this flag for non library level entities, since for any
1682 -- library level entities, assignments could exist in other units.
1685 if not Is_Library_Level_Entity (Id) then
1687 -- For now we omit this, because it seems to cause some
1688 -- problems. In particular, if you uncomment this out, then
1689 -- test case 4427-002 will fail for unclear reasons ???
1692 Set_Is_True_Constant (Id);
1696 -- Case of no initializing expression present. If the type is not
1697 -- fully initialized, then we set Not_Source_Assigned, since this
1698 -- is a case of a potentially uninitialized object. Note that we
1699 -- do not consider access variables to be fully initialized for
1700 -- this purpose, since it still seems dubious if someone declares
1701 -- an access variable and never assigns to it.
1704 if Is_Access_Type (T)
1705 or else not Is_Fully_Initialized_Type (T)
1707 Set_Not_Source_Assigned (Id);
1712 Init_Alignment (Id);
1715 if Aliased_Present (N) then
1716 Set_Is_Aliased (Id);
1719 and then Is_Record_Type (T)
1720 and then not Is_Constrained (T)
1721 and then Has_Discriminants (T)
1723 Set_Actual_Subtype (Id, Build_Default_Subtype);
1727 Set_Etype (Id, Act_T);
1729 if Has_Controlled_Component (Etype (Id))
1730 or else Is_Controlled (Etype (Id))
1732 if not Is_Library_Level_Entity (Id) then
1733 Check_Restriction (No_Nested_Finalization, N);
1736 Validate_Controlled_Object (Id);
1739 -- Generate a warning when an initialization causes an obvious
1740 -- ABE violation. If the init expression is a simple aggregate
1741 -- there shouldn't be any initialize/adjust call generated. This
1742 -- will be true as soon as aggregates are built in place when
1743 -- possible. ??? at the moment we do not generate warnings for
1744 -- temporaries created for those aggregates although a
1745 -- Program_Error might be generated if compiled with -gnato
1747 if Is_Controlled (Etype (Id))
1748 and then Comes_From_Source (Id)
1751 BT : constant Entity_Id := Base_Type (Etype (Id));
1752 Implicit_Call : Entity_Id;
1754 function Is_Aggr (N : Node_Id) return Boolean;
1755 -- Check that N is an aggregate
1757 function Is_Aggr (N : Node_Id) return Boolean is
1759 case Nkind (Original_Node (N)) is
1760 when N_Aggregate | N_Extension_Aggregate =>
1763 when N_Qualified_Expression |
1765 N_Unchecked_Type_Conversion =>
1766 return Is_Aggr (Expression (Original_Node (N)));
1774 -- If no underlying type, we already are in an error situation
1775 -- don't try to add a warning since we do not have access
1778 if No (Underlying_Type (BT)) then
1779 Implicit_Call := Empty;
1781 -- A generic type does not have usable primitive operators.
1782 -- Initialization calls are built for instances.
1784 elsif Is_Generic_Type (BT) then
1785 Implicit_Call := Empty;
1787 -- if the init expression is not an aggregate, an adjust
1788 -- call will be generated
1790 elsif Present (E) and then not Is_Aggr (E) then
1791 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
1793 -- if no init expression and we are not in the deferred
1794 -- constant case, an Initialize call will be generated
1796 elsif No (E) and then not Constant_Present (N) then
1797 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
1800 Implicit_Call := Empty;
1806 if Has_Task (Etype (Id)) then
1807 if not Is_Library_Level_Entity (Id) then
1808 Check_Restriction (No_Task_Hierarchy, N);
1809 Check_Potentially_Blocking_Operation (N);
1813 -- Some simple constant-propagation: if the expression is a constant
1814 -- string initialized with a literal, share the literal. This avoids
1818 and then Is_Entity_Name (E)
1819 and then Ekind (Entity (E)) = E_Constant
1820 and then Base_Type (Etype (E)) = Standard_String
1823 Val : constant Node_Id := Constant_Value (Entity (E));
1827 and then Nkind (Val) = N_String_Literal
1829 Rewrite (E, New_Copy (Val));
1834 -- Another optimization: if the nominal subtype is unconstrained and
1835 -- the expression is a function call that returns and unconstrained
1836 -- type, rewrite the declararation as a renaming of the result of the
1837 -- call. The exceptions below are cases where the copy is expected,
1838 -- either by the back end (Aliased case) or by the semantics, as for
1839 -- initializing controlled types or copying tags for classwide types.
1842 and then Nkind (E) = N_Explicit_Dereference
1843 and then Nkind (Original_Node (E)) = N_Function_Call
1844 and then not Is_Library_Level_Entity (Id)
1845 and then not Is_Constrained (T)
1846 and then not Is_Aliased (Id)
1847 and then not Is_Class_Wide_Type (T)
1848 and then not Is_Controlled (T)
1849 and then not Has_Controlled_Component (Base_Type (T))
1850 and then Expander_Active
1853 Make_Object_Renaming_Declaration (Loc,
1854 Defining_Identifier => Id,
1855 Subtype_Mark => New_Occurrence_Of
1856 (Base_Type (Etype (Id)), Loc),
1859 Set_Renamed_Object (Id, E);
1862 if Present (Prev_Entity)
1863 and then Is_Frozen (Prev_Entity)
1864 and then not Error_Posted (Id)
1866 Error_Msg_N ("full constant declaration appears too late", N);
1869 Check_Eliminated (Id);
1870 end Analyze_Object_Declaration;
1872 ---------------------------
1873 -- Analyze_Others_Choice --
1874 ---------------------------
1876 -- Nothing to do for the others choice node itself, the semantic analysis
1877 -- of the others choice will occur as part of the processing of the parent
1879 procedure Analyze_Others_Choice (N : Node_Id) is
1882 end Analyze_Others_Choice;
1884 -------------------------------------------
1885 -- Analyze_Private_Extension_Declaration --
1886 -------------------------------------------
1888 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
1889 T : Entity_Id := Defining_Identifier (N);
1890 Indic : constant Node_Id := Subtype_Indication (N);
1891 Parent_Type : Entity_Id;
1892 Parent_Base : Entity_Id;
1895 Generate_Definition (T);
1898 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
1899 Parent_Base := Base_Type (Parent_Type);
1901 if Parent_Type = Any_Type
1902 or else Etype (Parent_Type) = Any_Type
1904 Set_Ekind (T, Ekind (Parent_Type));
1905 Set_Etype (T, Any_Type);
1908 elsif not Is_Tagged_Type (Parent_Type) then
1910 ("parent of type extension must be a tagged type ", Indic);
1913 elsif Ekind (Parent_Type) = E_Void
1914 or else Ekind (Parent_Type) = E_Incomplete_Type
1916 Error_Msg_N ("premature derivation of incomplete type", Indic);
1920 -- Perhaps the parent type should be changed to the class-wide type's
1921 -- specific type in this case to prevent cascading errors ???
1923 if Is_Class_Wide_Type (Parent_Type) then
1925 ("parent of type extension must not be a class-wide type", Indic);
1929 if (not Is_Package (Current_Scope)
1930 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
1931 or else In_Private_Part (Current_Scope)
1934 Error_Msg_N ("invalid context for private extension", N);
1937 -- Set common attributes
1939 Set_Is_Pure (T, Is_Pure (Current_Scope));
1940 Set_Scope (T, Current_Scope);
1941 Set_Ekind (T, E_Record_Type_With_Private);
1942 Init_Size_Align (T);
1944 Set_Etype (T, Parent_Base);
1945 Set_Has_Task (T, Has_Task (Parent_Base));
1947 Set_Convention (T, Convention (Parent_Type));
1948 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
1949 Set_Is_First_Subtype (T);
1950 Make_Class_Wide_Type (T);
1952 Build_Derived_Record_Type (N, Parent_Type, T);
1953 end Analyze_Private_Extension_Declaration;
1955 ---------------------------------
1956 -- Analyze_Subtype_Declaration --
1957 ---------------------------------
1959 procedure Analyze_Subtype_Declaration (N : Node_Id) is
1960 Id : constant Entity_Id := Defining_Identifier (N);
1962 R_Checks : Check_Result;
1965 Generate_Definition (Id);
1966 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1967 Init_Size_Align (Id);
1969 -- The following guard condition on Enter_Name is to handle cases
1970 -- where the defining identifier has already been entered into the
1971 -- scope but the declaration as a whole needs to be analyzed.
1973 -- This case in particular happens for derived enumeration types.
1974 -- The derived enumeration type is processed as an inserted enumeration
1975 -- type declaration followed by a rewritten subtype declaration. The
1976 -- defining identifier, however, is entered into the name scope very
1977 -- early in the processing of the original type declaration and
1978 -- therefore needs to be avoided here, when the created subtype
1979 -- declaration is analyzed. (See Build_Derived_Types)
1981 -- This also happens when the full view of a private type is a
1982 -- derived type with constraints. In this case the entity has been
1983 -- introduced in the private declaration.
1985 if Present (Etype (Id))
1986 and then (Is_Private_Type (Etype (Id))
1987 or else Is_Task_Type (Etype (Id))
1988 or else Is_Rewrite_Substitution (N))
1996 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
1998 -- Inherit common attributes
2000 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
2001 Set_Is_Volatile (Id, Is_Volatile (T));
2002 Set_Is_Atomic (Id, Is_Atomic (T));
2004 -- In the case where there is no constraint given in the subtype
2005 -- indication, Process_Subtype just returns the Subtype_Mark,
2006 -- so its semantic attributes must be established here.
2008 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
2009 Set_Etype (Id, Base_Type (T));
2013 Set_Ekind (Id, E_Array_Subtype);
2015 -- Shouldn't we call Copy_Array_Subtype_Attributes here???
2017 Set_First_Index (Id, First_Index (T));
2018 Set_Is_Aliased (Id, Is_Aliased (T));
2019 Set_Is_Constrained (Id, Is_Constrained (T));
2021 when Decimal_Fixed_Point_Kind =>
2022 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
2023 Set_Digits_Value (Id, Digits_Value (T));
2024 Set_Delta_Value (Id, Delta_Value (T));
2025 Set_Scale_Value (Id, Scale_Value (T));
2026 Set_Small_Value (Id, Small_Value (T));
2027 Set_Scalar_Range (Id, Scalar_Range (T));
2028 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
2029 Set_Is_Constrained (Id, Is_Constrained (T));
2030 Set_RM_Size (Id, RM_Size (T));
2032 when Enumeration_Kind =>
2033 Set_Ekind (Id, E_Enumeration_Subtype);
2034 Set_First_Literal (Id, First_Literal (Base_Type (T)));
2035 Set_Scalar_Range (Id, Scalar_Range (T));
2036 Set_Is_Character_Type (Id, Is_Character_Type (T));
2037 Set_Is_Constrained (Id, Is_Constrained (T));
2038 Set_RM_Size (Id, RM_Size (T));
2040 when Ordinary_Fixed_Point_Kind =>
2041 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
2042 Set_Scalar_Range (Id, Scalar_Range (T));
2043 Set_Small_Value (Id, Small_Value (T));
2044 Set_Delta_Value (Id, Delta_Value (T));
2045 Set_Is_Constrained (Id, Is_Constrained (T));
2046 Set_RM_Size (Id, RM_Size (T));
2049 Set_Ekind (Id, E_Floating_Point_Subtype);
2050 Set_Scalar_Range (Id, Scalar_Range (T));
2051 Set_Digits_Value (Id, Digits_Value (T));
2052 Set_Is_Constrained (Id, Is_Constrained (T));
2054 when Signed_Integer_Kind =>
2055 Set_Ekind (Id, E_Signed_Integer_Subtype);
2056 Set_Scalar_Range (Id, Scalar_Range (T));
2057 Set_Is_Constrained (Id, Is_Constrained (T));
2058 Set_RM_Size (Id, RM_Size (T));
2060 when Modular_Integer_Kind =>
2061 Set_Ekind (Id, E_Modular_Integer_Subtype);
2062 Set_Scalar_Range (Id, Scalar_Range (T));
2063 Set_Is_Constrained (Id, Is_Constrained (T));
2064 Set_RM_Size (Id, RM_Size (T));
2066 when Class_Wide_Kind =>
2067 Set_Ekind (Id, E_Class_Wide_Subtype);
2068 Set_First_Entity (Id, First_Entity (T));
2069 Set_Last_Entity (Id, Last_Entity (T));
2070 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2071 Set_Cloned_Subtype (Id, T);
2072 Set_Is_Tagged_Type (Id, True);
2073 Set_Has_Unknown_Discriminants
2076 if Ekind (T) = E_Class_Wide_Subtype then
2077 Set_Equivalent_Type (Id, Equivalent_Type (T));
2080 when E_Record_Type | E_Record_Subtype =>
2081 Set_Ekind (Id, E_Record_Subtype);
2083 if Ekind (T) = E_Record_Subtype
2084 and then Present (Cloned_Subtype (T))
2086 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
2088 Set_Cloned_Subtype (Id, T);
2091 Set_First_Entity (Id, First_Entity (T));
2092 Set_Last_Entity (Id, Last_Entity (T));
2093 Set_Has_Discriminants (Id, Has_Discriminants (T));
2094 Set_Is_Constrained (Id, Is_Constrained (T));
2095 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2096 Set_Has_Unknown_Discriminants
2097 (Id, Has_Unknown_Discriminants (T));
2099 if Has_Discriminants (T) then
2100 Set_Discriminant_Constraint
2101 (Id, Discriminant_Constraint (T));
2102 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2104 elsif Has_Unknown_Discriminants (Id) then
2105 Set_Discriminant_Constraint (Id, No_Elist);
2108 if Is_Tagged_Type (T) then
2109 Set_Is_Tagged_Type (Id);
2110 Set_Is_Abstract (Id, Is_Abstract (T));
2111 Set_Primitive_Operations
2112 (Id, Primitive_Operations (T));
2113 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2116 when Private_Kind =>
2117 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2118 Set_Has_Discriminants (Id, Has_Discriminants (T));
2119 Set_Is_Constrained (Id, Is_Constrained (T));
2120 Set_First_Entity (Id, First_Entity (T));
2121 Set_Last_Entity (Id, Last_Entity (T));
2122 Set_Private_Dependents (Id, New_Elmt_List);
2123 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2124 Set_Has_Unknown_Discriminants
2125 (Id, Has_Unknown_Discriminants (T));
2127 if Is_Tagged_Type (T) then
2128 Set_Is_Tagged_Type (Id);
2129 Set_Is_Abstract (Id, Is_Abstract (T));
2130 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2133 -- In general the attributes of the subtype of a private
2134 -- type are the attributes of the partial view of parent.
2135 -- However, the full view may be a discriminated type,
2136 -- and the subtype must share the discriminant constraint
2137 -- to generate correct calls to initialization procedures.
2139 if Has_Discriminants (T) then
2140 Set_Discriminant_Constraint
2141 (Id, Discriminant_Constraint (T));
2142 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2144 elsif Present (Full_View (T))
2145 and then Has_Discriminants (Full_View (T))
2147 Set_Discriminant_Constraint
2148 (Id, Discriminant_Constraint (Full_View (T)));
2149 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2151 -- This would seem semantically correct, but apparently
2152 -- confuses the back-end (4412-009). To be explained ???
2154 -- Set_Has_Discriminants (Id);
2157 Prepare_Private_Subtype_Completion (Id, N);
2160 Set_Ekind (Id, E_Access_Subtype);
2161 Set_Is_Constrained (Id, Is_Constrained (T));
2162 Set_Is_Access_Constant
2163 (Id, Is_Access_Constant (T));
2164 Set_Directly_Designated_Type
2165 (Id, Designated_Type (T));
2167 -- A Pure library_item must not contain the declaration of a
2168 -- named access type, except within a subprogram, generic
2169 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
2171 if Comes_From_Source (Id)
2172 and then In_Pure_Unit
2173 and then not In_Subprogram_Task_Protected_Unit
2176 ("named access types not allowed in pure unit", N);
2179 when Concurrent_Kind =>
2181 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2182 Set_Corresponding_Record_Type (Id,
2183 Corresponding_Record_Type (T));
2184 Set_First_Entity (Id, First_Entity (T));
2185 Set_First_Private_Entity (Id, First_Private_Entity (T));
2186 Set_Has_Discriminants (Id, Has_Discriminants (T));
2187 Set_Is_Constrained (Id, Is_Constrained (T));
2188 Set_Last_Entity (Id, Last_Entity (T));
2190 if Has_Discriminants (T) then
2191 Set_Discriminant_Constraint (Id,
2192 Discriminant_Constraint (T));
2193 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2196 -- If the subtype name denotes an incomplete type
2197 -- an error was already reported by Process_Subtype.
2199 when E_Incomplete_Type =>
2200 Set_Etype (Id, Any_Type);
2203 raise Program_Error;
2207 if Etype (Id) = Any_Type then
2211 -- Some common processing on all types
2213 Set_Size_Info (Id, T);
2214 Set_First_Rep_Item (Id, First_Rep_Item (T));
2218 Set_Is_Immediately_Visible (Id, True);
2219 Set_Depends_On_Private (Id, Has_Private_Component (T));
2221 if Present (Generic_Parent_Type (N))
2224 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
2226 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
2227 /= N_Formal_Private_Type_Definition)
2229 if Is_Tagged_Type (Id) then
2230 if Is_Class_Wide_Type (Id) then
2231 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
2233 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
2236 elsif Scope (Etype (Id)) /= Standard_Standard then
2237 Derive_Subprograms (Generic_Parent_Type (N), Id);
2241 if Is_Private_Type (T)
2242 and then Present (Full_View (T))
2244 Conditional_Delay (Id, Full_View (T));
2246 -- The subtypes of components or subcomponents of protected types
2247 -- do not need freeze nodes, which would otherwise appear in the
2248 -- wrong scope (before the freeze node for the protected type). The
2249 -- proper subtypes are those of the subcomponents of the corresponding
2252 elsif Ekind (Scope (Id)) /= E_Protected_Type
2253 and then Present (Scope (Scope (Id))) -- error defense!
2254 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
2256 Conditional_Delay (Id, T);
2259 -- Check that constraint_error is raised for a scalar subtype
2260 -- indication when the lower or upper bound of a non-null range
2261 -- lies outside the range of the type mark.
2263 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
2264 if Is_Scalar_Type (Etype (Id))
2265 and then Scalar_Range (Id) /=
2266 Scalar_Range (Etype (Subtype_Mark
2267 (Subtype_Indication (N))))
2271 Etype (Subtype_Mark (Subtype_Indication (N))));
2273 elsif Is_Array_Type (Etype (Id))
2274 and then Present (First_Index (Id))
2276 -- This really should be a subprogram that finds the indications
2279 if ((Nkind (First_Index (Id)) = N_Identifier
2280 and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
2281 or else Nkind (First_Index (Id)) = N_Subtype_Indication)
2283 Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
2286 Target_Typ : Entity_Id :=
2289 (Etype (Subtype_Mark (Subtype_Indication (N)))));
2293 (Scalar_Range (Etype (First_Index (Id))),
2295 Etype (First_Index (Id)),
2296 Defining_Identifier (N));
2302 Sloc (Defining_Identifier (N)));
2308 Check_Eliminated (Id);
2309 end Analyze_Subtype_Declaration;
2311 --------------------------------
2312 -- Analyze_Subtype_Indication --
2313 --------------------------------
2315 procedure Analyze_Subtype_Indication (N : Node_Id) is
2316 T : constant Entity_Id := Subtype_Mark (N);
2317 R : constant Node_Id := Range_Expression (Constraint (N));
2324 Set_Etype (N, Etype (R));
2326 Set_Error_Posted (R);
2327 Set_Error_Posted (T);
2329 end Analyze_Subtype_Indication;
2331 ------------------------------
2332 -- Analyze_Type_Declaration --
2333 ------------------------------
2335 procedure Analyze_Type_Declaration (N : Node_Id) is
2336 Def : constant Node_Id := Type_Definition (N);
2337 Def_Id : constant Entity_Id := Defining_Identifier (N);
2342 Prev := Find_Type_Name (N);
2344 if Ekind (Prev) = E_Incomplete_Type then
2345 T := Full_View (Prev);
2350 Set_Is_Pure (T, Is_Pure (Current_Scope));
2352 -- We set the flag Is_First_Subtype here. It is needed to set the
2353 -- corresponding flag for the Implicit class-wide-type created
2354 -- during tagged types processing.
2356 Set_Is_First_Subtype (T, True);
2358 -- Only composite types other than array types are allowed to have
2363 -- For derived types, the rule will be checked once we've figured
2364 -- out the parent type.
2366 when N_Derived_Type_Definition =>
2369 -- For record types, discriminants are allowed.
2371 when N_Record_Definition =>
2375 if Present (Discriminant_Specifications (N)) then
2377 ("elementary or array type cannot have discriminants",
2379 (First (Discriminant_Specifications (N))));
2383 -- Elaborate the type definition according to kind, and generate
2384 -- susbsidiary (implicit) subtypes where needed. We skip this if
2385 -- it was already done (this happens during the reanalysis that
2386 -- follows a call to the high level optimizer).
2388 if not Analyzed (T) then
2393 when N_Access_To_Subprogram_Definition =>
2394 Access_Subprogram_Declaration (T, Def);
2396 -- If this is a remote access to subprogram, we must create
2397 -- the equivalent fat pointer type, and related subprograms.
2399 if Is_Remote_Types (Current_Scope)
2400 or else Is_Remote_Call_Interface (Current_Scope)
2402 Validate_Remote_Access_To_Subprogram_Type (N);
2403 Process_Remote_AST_Declaration (N);
2406 -- Validate categorization rule against access type declaration
2407 -- usually a violation in Pure unit, Shared_Passive unit.
2409 Validate_Access_Type_Declaration (T, N);
2411 when N_Access_To_Object_Definition =>
2412 Access_Type_Declaration (T, Def);
2414 -- Validate categorization rule against access type declaration
2415 -- usually a violation in Pure unit, Shared_Passive unit.
2417 Validate_Access_Type_Declaration (T, N);
2419 -- If we are in a Remote_Call_Interface package and define
2420 -- a RACW, Read and Write attribute must be added.
2422 if (Is_Remote_Call_Interface (Current_Scope)
2423 or else Is_Remote_Types (Current_Scope))
2424 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2426 Add_RACW_Features (Def_Id);
2429 when N_Array_Type_Definition =>
2430 Array_Type_Declaration (T, Def);
2432 when N_Derived_Type_Definition =>
2433 Derived_Type_Declaration (T, N, T /= Def_Id);
2435 when N_Enumeration_Type_Definition =>
2436 Enumeration_Type_Declaration (T, Def);
2438 when N_Floating_Point_Definition =>
2439 Floating_Point_Type_Declaration (T, Def);
2441 when N_Decimal_Fixed_Point_Definition =>
2442 Decimal_Fixed_Point_Type_Declaration (T, Def);
2444 when N_Ordinary_Fixed_Point_Definition =>
2445 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2447 when N_Signed_Integer_Type_Definition =>
2448 Signed_Integer_Type_Declaration (T, Def);
2450 when N_Modular_Type_Definition =>
2451 Modular_Type_Declaration (T, Def);
2453 when N_Record_Definition =>
2454 Record_Type_Declaration (T, N);
2457 raise Program_Error;
2462 if Etype (T) = Any_Type then
2466 -- Some common processing for all types
2468 Set_Depends_On_Private (T, Has_Private_Component (T));
2470 -- Both the declared entity, and its anonymous base type if one
2471 -- was created, need freeze nodes allocated.
2474 B : constant Entity_Id := Base_Type (T);
2477 -- In the case where the base type is different from the first
2478 -- subtype, we pre-allocate a freeze node, and set the proper
2479 -- link to the first subtype. Freeze_Entity will use this
2480 -- preallocated freeze node when it freezes the entity.
2483 Ensure_Freeze_Node (B);
2484 Set_First_Subtype_Link (Freeze_Node (B), T);
2487 if not From_With_Type (T) then
2488 Set_Has_Delayed_Freeze (T);
2492 -- Case of T is the full declaration of some private type which has
2493 -- been swapped in Defining_Identifier (N).
2495 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2496 Process_Full_View (N, T, Def_Id);
2498 -- Record the reference. The form of this is a little strange,
2499 -- since the full declaration has been swapped in. So the first
2500 -- parameter here represents the entity to which a reference is
2501 -- made which is the "real" entity, i.e. the one swapped in,
2502 -- and the second parameter provides the reference location.
2504 Generate_Reference (T, T, 'c');
2506 -- If in main unit, set as referenced, so we do not complain about
2507 -- the full declaration being an unreferenced entity.
2509 if In_Extended_Main_Source_Unit (Def_Id) then
2510 Set_Referenced (Def_Id);
2513 -- For completion of incomplete type, process incomplete dependents
2514 -- and always mark the full type as referenced (it is the incomplete
2515 -- type that we get for any real reference).
2517 elsif Ekind (Prev) = E_Incomplete_Type then
2518 Process_Incomplete_Dependents (N, T, Prev);
2519 Generate_Reference (Prev, Def_Id, 'c');
2521 -- If in main unit, set as referenced, so we do not complain about
2522 -- the full declaration being an unreferenced entity.
2524 if In_Extended_Main_Source_Unit (Def_Id) then
2525 Set_Referenced (Def_Id);
2528 -- If not private type or incomplete type completion, this is a real
2529 -- definition of a new entity, so record it.
2532 Generate_Definition (Def_Id);
2535 Check_Eliminated (Def_Id);
2536 end Analyze_Type_Declaration;
2538 --------------------------
2539 -- Analyze_Variant_Part --
2540 --------------------------
2542 procedure Analyze_Variant_Part (N : Node_Id) is
2544 procedure Non_Static_Choice_Error (Choice : Node_Id);
2545 -- Error routine invoked by the generic instantiation below when
2546 -- the variant part has a non static choice.
2548 procedure Process_Declarations (Variant : Node_Id);
2549 -- Analyzes all the declarations associated with a Variant.
2550 -- Needed by the generic instantiation below.
2552 package Variant_Choices_Processing is new
2553 Generic_Choices_Processing
2554 (Get_Alternatives => Variants,
2555 Get_Choices => Discrete_Choices,
2556 Process_Empty_Choice => No_OP,
2557 Process_Non_Static_Choice => Non_Static_Choice_Error,
2558 Process_Associated_Node => Process_Declarations);
2559 use Variant_Choices_Processing;
2560 -- Instantiation of the generic choice processing package.
2562 -----------------------------
2563 -- Non_Static_Choice_Error --
2564 -----------------------------
2566 procedure Non_Static_Choice_Error (Choice : Node_Id) is
2568 Error_Msg_N ("choice given in variant part is not static", Choice);
2569 end Non_Static_Choice_Error;
2571 --------------------------
2572 -- Process_Declarations --
2573 --------------------------
2575 procedure Process_Declarations (Variant : Node_Id) is
2577 if not Null_Present (Component_List (Variant)) then
2578 Analyze_Declarations (Component_Items (Component_List (Variant)));
2580 if Present (Variant_Part (Component_List (Variant))) then
2581 Analyze (Variant_Part (Component_List (Variant)));
2584 end Process_Declarations;
2586 -- Variables local to Analyze_Case_Statement.
2588 Others_Choice : Node_Id;
2590 Discr_Name : Node_Id;
2591 Discr_Type : Entity_Id;
2593 Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
2595 Dont_Care : Boolean;
2596 Others_Present : Boolean := False;
2598 -- Start of processing for Analyze_Variant_Part
2601 Discr_Name := Name (N);
2602 Analyze (Discr_Name);
2604 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
2605 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
2608 Discr_Type := Etype (Entity (Discr_Name));
2610 -- Call the instantiated Analyze_Choices which does the rest of the work
2613 (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
2615 if Others_Present then
2616 -- Fill in Others_Discrete_Choices field of the OTHERS choice
2618 Others_Choice := First (Discrete_Choices (Last (Variants (N))));
2619 Expand_Others_Choice
2620 (Case_Table (1 .. Last_Choice), Others_Choice, Discr_Type);
2623 end Analyze_Variant_Part;
2625 ----------------------------
2626 -- Array_Type_Declaration --
2627 ----------------------------
2629 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
2630 Component_Def : constant Node_Id := Subtype_Indication (Def);
2631 Element_Type : Entity_Id;
2632 Implicit_Base : Entity_Id;
2634 Related_Id : Entity_Id := Empty;
2636 P : constant Node_Id := Parent (Def);
2640 if Nkind (Def) = N_Constrained_Array_Definition then
2642 Index := First (Discrete_Subtype_Definitions (Def));
2644 -- Find proper names for the implicit types which may be public.
2645 -- in case of anonymous arrays we use the name of the first object
2646 -- of that type as prefix.
2649 Related_Id := Defining_Identifier (P);
2655 Index := First (Subtype_Marks (Def));
2660 while Present (Index) loop
2662 Make_Index (Index, P, Related_Id, Nb_Index);
2664 Nb_Index := Nb_Index + 1;
2667 Element_Type := Process_Subtype (Component_Def, P, Related_Id, 'C');
2669 -- Constrained array case
2672 T := Create_Itype (E_Void, P, Related_Id, 'T');
2675 if Nkind (Def) = N_Constrained_Array_Definition then
2677 -- Establish Implicit_Base as unconstrained base type
2679 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
2681 Init_Size_Align (Implicit_Base);
2682 Set_Etype (Implicit_Base, Implicit_Base);
2683 Set_Scope (Implicit_Base, Current_Scope);
2684 Set_Has_Delayed_Freeze (Implicit_Base);
2686 -- The constrained array type is a subtype of the unconstrained one
2688 Set_Ekind (T, E_Array_Subtype);
2689 Init_Size_Align (T);
2690 Set_Etype (T, Implicit_Base);
2691 Set_Scope (T, Current_Scope);
2692 Set_Is_Constrained (T, True);
2693 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
2694 Set_Has_Delayed_Freeze (T);
2696 -- Complete setup of implicit base type
2698 Set_First_Index (Implicit_Base, First_Index (T));
2699 Set_Component_Type (Implicit_Base, Element_Type);
2700 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
2701 Set_Component_Size (Implicit_Base, Uint_0);
2702 Set_Has_Controlled_Component (Implicit_Base,
2703 Has_Controlled_Component (Element_Type)
2704 or else Is_Controlled (Element_Type));
2705 Set_Finalize_Storage_Only (Implicit_Base,
2706 Finalize_Storage_Only (Element_Type));
2708 -- Unconstrained array case
2711 Set_Ekind (T, E_Array_Type);
2712 Init_Size_Align (T);
2714 Set_Scope (T, Current_Scope);
2715 Set_Component_Size (T, Uint_0);
2716 Set_Is_Constrained (T, False);
2717 Set_First_Index (T, First (Subtype_Marks (Def)));
2718 Set_Has_Delayed_Freeze (T, True);
2719 Set_Has_Task (T, Has_Task (Element_Type));
2720 Set_Has_Controlled_Component (T,
2721 Has_Controlled_Component (Element_Type)
2722 or else Is_Controlled (Element_Type));
2723 Set_Finalize_Storage_Only (T,
2724 Finalize_Storage_Only (Element_Type));
2727 Set_Component_Type (T, Element_Type);
2729 if Aliased_Present (Def) then
2730 Set_Has_Aliased_Components (Etype (T));
2733 Priv := Private_Component (Element_Type);
2735 if Present (Priv) then
2736 -- Check for circular definitions.
2738 if Priv = Any_Type then
2739 Set_Component_Type (T, Any_Type);
2740 Set_Component_Type (Etype (T), Any_Type);
2742 -- There is a gap in the visiblity of operations on the composite
2743 -- type only if the component type is defined in a different scope.
2745 elsif Scope (Priv) = Current_Scope then
2748 elsif Is_Limited_Type (Priv) then
2749 Set_Is_Limited_Composite (Etype (T));
2750 Set_Is_Limited_Composite (T);
2752 Set_Is_Private_Composite (Etype (T));
2753 Set_Is_Private_Composite (T);
2757 -- Create a concatenation operator for the new type. Internal
2758 -- array types created for packed entities do not need such, they
2759 -- are compatible with the user-defined type.
2761 if Number_Dimensions (T) = 1
2762 and then not Is_Packed_Array_Type (T)
2764 New_Binary_Operator (Name_Op_Concat, T);
2767 -- In the case of an unconstrained array the parser has already
2768 -- verified that all the indices are unconstrained but we still
2769 -- need to make sure that the element type is constrained.
2771 if Is_Indefinite_Subtype (Element_Type) then
2773 ("unconstrained element type in array declaration ",
2776 elsif Is_Abstract (Element_Type) then
2777 Error_Msg_N ("The type of a component cannot be abstract ",
2781 end Array_Type_Declaration;
2783 -------------------------------
2784 -- Build_Derived_Access_Type --
2785 -------------------------------
2787 procedure Build_Derived_Access_Type
2789 Parent_Type : Entity_Id;
2790 Derived_Type : Entity_Id)
2792 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
2794 Desig_Type : Entity_Id;
2796 Discr_Con_Elist : Elist_Id;
2797 Discr_Con_El : Elmt_Id;
2802 -- Set the designated type so it is available in case this is
2803 -- an access to a self-referential type, e.g. a standard list
2804 -- type with a next pointer. Will be reset after subtype is built.
2806 Set_Directly_Designated_Type (Derived_Type,
2807 Designated_Type (Parent_Type));
2809 Subt := Process_Subtype (S, N);
2811 if Nkind (S) /= N_Subtype_Indication
2812 and then Subt /= Base_Type (Subt)
2814 Set_Ekind (Derived_Type, E_Access_Subtype);
2817 if Ekind (Derived_Type) = E_Access_Subtype then
2819 Pbase : constant Entity_Id := Base_Type (Parent_Type);
2820 Ibase : constant Entity_Id :=
2821 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
2822 Svg_Chars : constant Name_Id := Chars (Ibase);
2823 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
2826 Copy_Node (Pbase, Ibase);
2828 Set_Chars (Ibase, Svg_Chars);
2829 Set_Next_Entity (Ibase, Svg_Next_E);
2830 Set_Sloc (Ibase, Sloc (Derived_Type));
2831 Set_Scope (Ibase, Scope (Derived_Type));
2832 Set_Freeze_Node (Ibase, Empty);
2833 Set_Is_Frozen (Ibase, False);
2835 Set_Etype (Ibase, Pbase);
2836 Set_Etype (Derived_Type, Ibase);
2840 Set_Directly_Designated_Type
2841 (Derived_Type, Designated_Type (Subt));
2843 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
2844 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
2845 Set_Size_Info (Derived_Type, Parent_Type);
2846 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
2847 Set_Depends_On_Private (Derived_Type,
2848 Has_Private_Component (Derived_Type));
2849 Conditional_Delay (Derived_Type, Subt);
2851 -- Note: we do not copy the Storage_Size_Variable, since
2852 -- we always go to the root type for this information.
2854 -- Apply range checks to discriminants for derived record case
2855 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
2857 Desig_Type := Designated_Type (Derived_Type);
2858 if Is_Composite_Type (Desig_Type)
2859 and then (not Is_Array_Type (Desig_Type))
2860 and then Has_Discriminants (Desig_Type)
2861 and then Base_Type (Desig_Type) /= Desig_Type
2863 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
2864 Discr_Con_El := First_Elmt (Discr_Con_Elist);
2866 Discr := First_Discriminant (Base_Type (Desig_Type));
2867 while Present (Discr_Con_El) loop
2868 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
2869 Next_Elmt (Discr_Con_El);
2870 Next_Discriminant (Discr);
2873 end Build_Derived_Access_Type;
2875 ------------------------------
2876 -- Build_Derived_Array_Type --
2877 ------------------------------
2879 procedure Build_Derived_Array_Type
2881 Parent_Type : Entity_Id;
2882 Derived_Type : Entity_Id)
2884 Loc : constant Source_Ptr := Sloc (N);
2885 Tdef : constant Node_Id := Type_Definition (N);
2886 Indic : constant Node_Id := Subtype_Indication (Tdef);
2887 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
2888 Implicit_Base : Entity_Id;
2889 New_Indic : Node_Id;
2891 procedure Make_Implicit_Base;
2892 -- If the parent subtype is constrained, the derived type is a
2893 -- subtype of an implicit base type derived from the parent base.
2895 ------------------------
2896 -- Make_Implicit_Base --
2897 ------------------------
2899 procedure Make_Implicit_Base is
2902 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
2904 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
2905 Set_Etype (Implicit_Base, Parent_Base);
2907 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
2908 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
2910 Set_Has_Delayed_Freeze (Implicit_Base, True);
2911 end Make_Implicit_Base;
2913 -- Start of processing for Build_Derived_Array_Type
2916 if not Is_Constrained (Parent_Type) then
2917 if Nkind (Indic) /= N_Subtype_Indication then
2918 Set_Ekind (Derived_Type, E_Array_Type);
2920 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
2921 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
2923 Set_Has_Delayed_Freeze (Derived_Type, True);
2927 Set_Etype (Derived_Type, Implicit_Base);
2930 Make_Subtype_Declaration (Loc,
2931 Defining_Identifier => Derived_Type,
2932 Subtype_Indication =>
2933 Make_Subtype_Indication (Loc,
2934 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
2935 Constraint => Constraint (Indic)));
2937 Rewrite (N, New_Indic);
2942 if Nkind (Indic) /= N_Subtype_Indication then
2945 Set_Ekind (Derived_Type, Ekind (Parent_Type));
2946 Set_Etype (Derived_Type, Implicit_Base);
2947 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
2950 Error_Msg_N ("illegal constraint on constrained type", Indic);
2954 -- If the parent type is not a derived type itself, and is
2955 -- declared in a closed scope (e.g., a subprogram), then we
2956 -- need to explicitly introduce the new type's concatenation
2957 -- operator since Derive_Subprograms will not inherit the
2958 -- parent's operator.
2960 if Number_Dimensions (Parent_Type) = 1
2961 and then not Is_Limited_Type (Parent_Type)
2962 and then not Is_Derived_Type (Parent_Type)
2963 and then not Is_Package (Scope (Base_Type (Parent_Type)))
2965 New_Binary_Operator (Name_Op_Concat, Derived_Type);
2967 end Build_Derived_Array_Type;
2969 -----------------------------------
2970 -- Build_Derived_Concurrent_Type --
2971 -----------------------------------
2973 procedure Build_Derived_Concurrent_Type
2975 Parent_Type : Entity_Id;
2976 Derived_Type : Entity_Id)
2978 D_Constraint : Node_Id;
2979 Disc_Spec : Node_Id;
2980 Old_Disc : Entity_Id;
2981 New_Disc : Entity_Id;
2983 Constraint_Present : constant Boolean :=
2984 Nkind (Subtype_Indication (Type_Definition (N)))
2985 = N_Subtype_Indication;
2988 Set_Girder_Constraint (Derived_Type, No_Elist);
2990 if Is_Task_Type (Parent_Type) then
2991 Set_Storage_Size_Variable (Derived_Type,
2992 Storage_Size_Variable (Parent_Type));
2995 if Present (Discriminant_Specifications (N)) then
2996 New_Scope (Derived_Type);
2997 Check_Or_Process_Discriminants (N, Derived_Type);
3000 elsif Constraint_Present then
3002 -- Build constrained subtype and derive from it
3005 Loc : constant Source_Ptr := Sloc (N);
3007 Make_Defining_Identifier (Loc,
3008 New_External_Name (Chars (Derived_Type), 'T'));
3013 Make_Subtype_Declaration (Loc,
3014 Defining_Identifier => Anon,
3015 Subtype_Indication =>
3016 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
3017 Insert_Before (N, Decl);
3018 Rewrite (Subtype_Indication (Type_Definition (N)),
3019 New_Occurrence_Of (Anon, Loc));
3021 Set_Analyzed (Derived_Type, False);
3027 -- All attributes are inherited from parent. In particular,
3028 -- entries and the corresponding record type are the same.
3029 -- Discriminants may be renamed, and must be treated separately.
3031 Set_Has_Discriminants
3032 (Derived_Type, Has_Discriminants (Parent_Type));
3033 Set_Corresponding_Record_Type
3034 (Derived_Type, Corresponding_Record_Type (Parent_Type));
3036 if Constraint_Present then
3038 if not Has_Discriminants (Parent_Type) then
3039 Error_Msg_N ("untagged parent must have discriminants", N);
3041 elsif Present (Discriminant_Specifications (N)) then
3043 -- Verify that new discriminants are used to constrain
3046 Old_Disc := First_Discriminant (Parent_Type);
3047 New_Disc := First_Discriminant (Derived_Type);
3048 Disc_Spec := First (Discriminant_Specifications (N));
3052 (Constraint (Subtype_Indication (Type_Definition (N)))));
3054 while Present (Old_Disc) and then Present (Disc_Spec) loop
3056 if Nkind (Discriminant_Type (Disc_Spec)) /=
3059 Analyze (Discriminant_Type (Disc_Spec));
3061 if not Subtypes_Statically_Compatible (
3062 Etype (Discriminant_Type (Disc_Spec)),
3066 ("not statically compatible with parent discriminant",
3067 Discriminant_Type (Disc_Spec));
3071 if Nkind (D_Constraint) = N_Identifier
3072 and then Chars (D_Constraint) /=
3073 Chars (Defining_Identifier (Disc_Spec))
3075 Error_Msg_N ("new discriminants must constrain old ones",
3078 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
3081 Next_Discriminant (Old_Disc);
3082 Next_Discriminant (New_Disc);
3086 if Present (Old_Disc) or else Present (Disc_Spec) then
3087 Error_Msg_N ("discriminant mismatch in derivation", N);
3092 elsif Present (Discriminant_Specifications (N)) then
3094 ("missing discriminant constraint in untagged derivation",
3098 if Present (Discriminant_Specifications (N)) then
3100 Old_Disc := First_Discriminant (Parent_Type);
3102 while Present (Old_Disc) loop
3104 if No (Next_Entity (Old_Disc))
3105 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
3107 Set_Next_Entity (Last_Entity (Derived_Type),
3108 Next_Entity (Old_Disc));
3112 Next_Discriminant (Old_Disc);
3116 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
3117 if Has_Discriminants (Parent_Type) then
3118 Set_Discriminant_Constraint (
3119 Derived_Type, Discriminant_Constraint (Parent_Type));
3123 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
3125 Set_Has_Completion (Derived_Type);
3126 end Build_Derived_Concurrent_Type;
3128 ------------------------------------
3129 -- Build_Derived_Enumeration_Type --
3130 ------------------------------------
3132 procedure Build_Derived_Enumeration_Type
3134 Parent_Type : Entity_Id;
3135 Derived_Type : Entity_Id)
3137 Loc : constant Source_Ptr := Sloc (N);
3138 Def : constant Node_Id := Type_Definition (N);
3139 Indic : constant Node_Id := Subtype_Indication (Def);
3140 Implicit_Base : Entity_Id;
3141 Literal : Entity_Id;
3142 New_Lit : Entity_Id;
3143 Literals_List : List_Id;
3144 Type_Decl : Node_Id;
3146 Rang_Expr : Node_Id;
3149 -- Since types Standard.Character and Standard.Wide_Character do
3150 -- not have explicit literals lists we need to process types derived
3151 -- from them specially. This is handled by Derived_Standard_Character.
3152 -- If the parent type is a generic type, there are no literals either,
3153 -- and we construct the same skeletal representation as for the generic
3156 if Root_Type (Parent_Type) = Standard_Character
3157 or else Root_Type (Parent_Type) = Standard_Wide_Character
3159 Derived_Standard_Character (N, Parent_Type, Derived_Type);
3161 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
3168 Make_Attribute_Reference (Loc,
3169 Attribute_Name => Name_First,
3170 Prefix => New_Reference_To (Derived_Type, Loc));
3171 Set_Etype (Lo, Derived_Type);
3174 Make_Attribute_Reference (Loc,
3175 Attribute_Name => Name_Last,
3176 Prefix => New_Reference_To (Derived_Type, Loc));
3177 Set_Etype (Hi, Derived_Type);
3179 Set_Scalar_Range (Derived_Type,
3186 -- If a constraint is present, analyze the bounds to catch
3187 -- premature usage of the derived literals.
3189 if Nkind (Indic) = N_Subtype_Indication
3190 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
3192 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
3193 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
3196 -- Introduce an implicit base type for the derived type even
3197 -- if there is no constraint attached to it, since this seems
3198 -- closer to the Ada semantics. Build a full type declaration
3199 -- tree for the derived type using the implicit base type as
3200 -- the defining identifier. The build a subtype declaration
3201 -- tree which applies the constraint (if any) have it replace
3202 -- the derived type declaration.
3204 Literal := First_Literal (Parent_Type);
3205 Literals_List := New_List;
3207 while Present (Literal)
3208 and then Ekind (Literal) = E_Enumeration_Literal
3210 -- Literals of the derived type have the same representation as
3211 -- those of the parent type, but this representation can be
3212 -- overridden by an explicit representation clause. Indicate
3213 -- that there is no explicit representation given yet. These
3214 -- derived literals are implicit operations of the new type,
3215 -- and can be overriden by explicit ones.
3217 if Nkind (Literal) = N_Defining_Character_Literal then
3219 Make_Defining_Character_Literal (Loc, Chars (Literal));
3221 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
3224 Set_Ekind (New_Lit, E_Enumeration_Literal);
3225 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
3226 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
3227 Set_Enumeration_Rep_Expr (New_Lit, Empty);
3228 Set_Alias (New_Lit, Literal);
3229 Set_Is_Known_Valid (New_Lit, True);
3231 Append (New_Lit, Literals_List);
3232 Next_Literal (Literal);
3236 Make_Defining_Identifier (Sloc (Derived_Type),
3237 New_External_Name (Chars (Derived_Type), 'B'));
3239 -- Indicate the proper nature of the derived type. This must
3240 -- be done before analysis of the literals, to recognize cases
3241 -- when a literal may be hidden by a previous explicit function
3242 -- definition (cf. c83031a).
3244 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
3245 Set_Etype (Derived_Type, Implicit_Base);
3248 Make_Full_Type_Declaration (Loc,
3249 Defining_Identifier => Implicit_Base,
3250 Discriminant_Specifications => No_List,
3252 Make_Enumeration_Type_Definition (Loc, Literals_List));
3254 Mark_Rewrite_Insertion (Type_Decl);
3255 Insert_Before (N, Type_Decl);
3256 Analyze (Type_Decl);
3258 -- After the implicit base is analyzed its Etype needs to be
3259 -- changed to reflect the fact that it is derived from the
3260 -- parent type which was ignored during analysis. We also set
3261 -- the size at this point.
3263 Set_Etype (Implicit_Base, Parent_Type);
3265 Set_Size_Info (Implicit_Base, Parent_Type);
3266 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
3267 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
3269 Set_Has_Non_Standard_Rep
3270 (Implicit_Base, Has_Non_Standard_Rep
3272 Set_Has_Delayed_Freeze (Implicit_Base);
3274 -- Process the subtype indication including a validation check
3275 -- on the constraint, if any. If a constraint is given, its bounds
3276 -- must be implicitly converted to the new type.
3278 if Nkind (Indic) = N_Subtype_Indication then
3281 R : constant Node_Id :=
3282 Range_Expression (Constraint (Indic));
3285 if Nkind (R) = N_Range then
3286 Hi := Build_Scalar_Bound
3287 (High_Bound (R), Parent_Type, Implicit_Base, Loc);
3288 Lo := Build_Scalar_Bound
3289 (Low_Bound (R), Parent_Type, Implicit_Base, Loc);
3292 -- Constraint is a Range attribute. Replace with the
3293 -- explicit mention of the bounds of the prefix, which
3294 -- must be a subtype.
3296 Analyze (Prefix (R));
3298 Convert_To (Implicit_Base,
3299 Make_Attribute_Reference (Loc,
3300 Attribute_Name => Name_Last,
3302 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3305 Convert_To (Implicit_Base,
3306 Make_Attribute_Reference (Loc,
3307 Attribute_Name => Name_First,
3309 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3317 (Type_High_Bound (Parent_Type),
3318 Parent_Type, Implicit_Base, Loc);
3321 (Type_Low_Bound (Parent_Type),
3322 Parent_Type, Implicit_Base, Loc);
3330 -- If we constructed a default range for the case where no range
3331 -- was given, then the expressions in the range must not freeze
3332 -- since they do not correspond to expressions in the source.
3334 if Nkind (Indic) /= N_Subtype_Indication then
3335 Set_Must_Not_Freeze (Lo);
3336 Set_Must_Not_Freeze (Hi);
3337 Set_Must_Not_Freeze (Rang_Expr);
3341 Make_Subtype_Declaration (Loc,
3342 Defining_Identifier => Derived_Type,
3343 Subtype_Indication =>
3344 Make_Subtype_Indication (Loc,
3345 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
3347 Make_Range_Constraint (Loc,
3348 Range_Expression => Rang_Expr))));
3352 -- If pragma Discard_Names applies on the first subtype
3353 -- of the parent type, then it must be applied on this
3356 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
3357 Set_Discard_Names (Derived_Type);
3360 -- Apply a range check. Since this range expression doesn't
3361 -- have an Etype, we have to specifically pass the Source_Typ
3362 -- parameter. Is this right???
3364 if Nkind (Indic) = N_Subtype_Indication then
3365 Apply_Range_Check (Range_Expression (Constraint (Indic)),
3367 Source_Typ => Entity (Subtype_Mark (Indic)));
3371 end Build_Derived_Enumeration_Type;
3373 --------------------------------
3374 -- Build_Derived_Numeric_Type --
3375 --------------------------------
3377 procedure Build_Derived_Numeric_Type
3379 Parent_Type : Entity_Id;
3380 Derived_Type : Entity_Id)
3382 Loc : constant Source_Ptr := Sloc (N);
3383 Tdef : constant Node_Id := Type_Definition (N);
3384 Indic : constant Node_Id := Subtype_Indication (Tdef);
3385 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3386 No_Constraint : constant Boolean := Nkind (Indic) /=
3387 N_Subtype_Indication;
3388 Implicit_Base : Entity_Id;
3395 -- Process the subtype indication including a validation check on
3396 -- the constraint if any.
3398 T := Process_Subtype (Indic, N);
3400 -- Introduce an implicit base type for the derived type even if
3401 -- there is no constraint attached to it, since this seems closer
3402 -- to the Ada semantics.
3405 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3407 Set_Etype (Implicit_Base, Parent_Base);
3408 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3409 Set_Size_Info (Implicit_Base, Parent_Base);
3410 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3411 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
3412 Set_Parent (Implicit_Base, Parent (Derived_Type));
3414 if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
3415 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3418 Set_Has_Delayed_Freeze (Implicit_Base);
3420 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
3421 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
3423 Set_Scalar_Range (Implicit_Base,
3428 if Has_Infinities (Parent_Base) then
3429 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
3432 -- The Derived_Type, which is the entity of the declaration, is
3433 -- a subtype of the implicit base. Its Ekind is a subtype, even
3434 -- in the absence of an explicit constraint.
3436 Set_Etype (Derived_Type, Implicit_Base);
3438 -- If we did not have a constraint, then the Ekind is set from the
3439 -- parent type (otherwise Process_Subtype has set the bounds)
3441 if No_Constraint then
3442 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
3445 -- If we did not have a range constraint, then set the range
3446 -- from the parent type. Otherwise, the call to Process_Subtype
3447 -- has set the bounds.
3450 or else not Has_Range_Constraint (Indic)
3452 Set_Scalar_Range (Derived_Type,
3454 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
3455 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
3456 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3458 if Has_Infinities (Parent_Type) then
3459 Set_Includes_Infinities (Scalar_Range (Derived_Type));
3463 -- Set remaining type-specific fields, depending on numeric type
3465 if Is_Modular_Integer_Type (Parent_Type) then
3466 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
3468 Set_Non_Binary_Modulus
3469 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
3471 elsif Is_Floating_Point_Type (Parent_Type) then
3473 -- Digits of base type is always copied from the digits value of
3474 -- the parent base type, but the digits of the derived type will
3475 -- already have been set if there was a constraint present.
3477 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3478 Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
3480 if No_Constraint then
3481 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
3484 elsif Is_Fixed_Point_Type (Parent_Type) then
3486 -- Small of base type and derived type are always copied from
3487 -- the parent base type, since smalls never change. The delta
3488 -- of the base type is also copied from the parent base type.
3489 -- However the delta of the derived type will have been set
3490 -- already if a constraint was present.
3492 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
3493 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
3494 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
3496 if No_Constraint then
3497 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
3500 -- The scale and machine radix in the decimal case are always
3501 -- copied from the parent base type.
3503 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
3504 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
3505 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
3507 Set_Machine_Radix_10
3508 (Derived_Type, Machine_Radix_10 (Parent_Base));
3509 Set_Machine_Radix_10
3510 (Implicit_Base, Machine_Radix_10 (Parent_Base));
3512 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3514 if No_Constraint then
3515 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
3518 -- the analysis of the subtype_indication sets the
3519 -- digits value of the derived type.
3526 -- The type of the bounds is that of the parent type, and they
3527 -- must be converted to the derived type.
3529 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
3531 -- The implicit_base should be frozen when the derived type is frozen,
3532 -- but note that it is used in the conversions of the bounds. For
3533 -- fixed types we delay the determination of the bounds until the proper
3534 -- freezing point. For other numeric types this is rejected by GCC, for
3535 -- reasons that are currently unclear (???), so we choose to freeze the
3536 -- implicit base now. In the case of integers and floating point types
3537 -- this is harmless because subsequent representation clauses cannot
3538 -- affect anything, but it is still baffling that we cannot use the
3539 -- same mechanism for all derived numeric types.
3541 if Is_Fixed_Point_Type (Parent_Type) then
3542 Conditional_Delay (Implicit_Base, Parent_Type);
3544 Freeze_Before (N, Implicit_Base);
3547 end Build_Derived_Numeric_Type;
3549 --------------------------------
3550 -- Build_Derived_Private_Type --
3551 --------------------------------
3553 procedure Build_Derived_Private_Type
3555 Parent_Type : Entity_Id;
3556 Derived_Type : Entity_Id;
3557 Is_Completion : Boolean;
3558 Derive_Subps : Boolean := True)
3560 Der_Base : Entity_Id;
3562 Full_Decl : Node_Id := Empty;
3563 Full_Der : Entity_Id;
3565 Last_Discr : Entity_Id;
3566 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
3567 Swapped : Boolean := False;
3569 procedure Copy_And_Build;
3570 -- Copy derived type declaration, replace parent with its full view,
3571 -- and analyze new declaration.
3573 procedure Copy_And_Build is
3577 if Ekind (Parent_Type) in Record_Kind
3578 or else (Ekind (Parent_Type) in Enumeration_Kind
3579 and then Root_Type (Parent_Type) /= Standard_Character
3580 and then Root_Type (Parent_Type) /= Standard_Wide_Character
3581 and then not Is_Generic_Type (Root_Type (Parent_Type)))
3583 Full_N := New_Copy_Tree (N);
3584 Insert_After (N, Full_N);
3585 Build_Derived_Type (
3586 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
3589 Build_Derived_Type (
3590 N, Parent_Type, Full_Der, True, Derive_Subps => False);
3594 -- Start of processing for Build_Derived_Private_Type
3597 if Is_Tagged_Type (Parent_Type) then
3598 Build_Derived_Record_Type
3599 (N, Parent_Type, Derived_Type, Derive_Subps);
3602 elsif Has_Discriminants (Parent_Type) then
3604 if Present (Full_View (Parent_Type)) then
3605 if not Is_Completion then
3607 -- Copy declaration for subsequent analysis.
3609 Full_Decl := New_Copy_Tree (N);
3610 Full_Der := New_Copy (Derived_Type);
3611 Insert_After (N, Full_Decl);
3614 -- If this is a completion, the full view being built is
3615 -- itself private. We build a subtype of the parent with
3616 -- the same constraints as this full view, to convey to the
3617 -- back end the constrained components and the size of this
3618 -- subtype. If the parent is constrained, its full view can
3619 -- serve as the underlying full view of the derived type.
3621 if No (Discriminant_Specifications (N)) then
3623 if Nkind (Subtype_Indication (Type_Definition (N)))
3624 = N_Subtype_Indication
3626 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
3628 elsif Is_Constrained (Full_View (Parent_Type)) then
3629 Set_Underlying_Full_View (Derived_Type,
3630 Full_View (Parent_Type));
3634 -- If there are new discriminants, the parent subtype is
3635 -- constrained by them, but it is not clear how to build
3636 -- the underlying_full_view in this case ???
3643 Build_Derived_Record_Type
3644 (N, Parent_Type, Derived_Type, Derive_Subps);
3646 if Present (Full_View (Parent_Type))
3647 and then not Is_Completion
3649 if not In_Open_Scopes (Par_Scope)
3650 or else not In_Same_Source_Unit (N, Parent_Type)
3652 -- Swap partial and full views temporarily
3654 Install_Private_Declarations (Par_Scope);
3655 Install_Visible_Declarations (Par_Scope);
3659 -- Subprograms have been derived on the private view,
3660 -- the completion does not derive them anew.
3662 Build_Derived_Record_Type
3663 (Full_Decl, Parent_Type, Full_Der, False);
3666 Uninstall_Declarations (Par_Scope);
3668 if In_Open_Scopes (Par_Scope) then
3669 Install_Visible_Declarations (Par_Scope);
3673 Der_Base := Base_Type (Derived_Type);
3674 Set_Full_View (Derived_Type, Full_Der);
3675 Set_Full_View (Der_Base, Base_Type (Full_Der));
3677 -- Copy the discriminant list from full view to
3678 -- the partial views (base type and its subtype).
3679 -- Gigi requires that the partial and full views
3680 -- have the same discriminants.
3681 -- ??? Note that since the partial view is pointing
3682 -- to discriminants in the full view, their scope
3683 -- will be that of the full view. This might
3684 -- cause some front end problems and need
3687 Discr := First_Discriminant (Base_Type (Full_Der));
3688 Set_First_Entity (Der_Base, Discr);
3691 Last_Discr := Discr;
3692 Next_Discriminant (Discr);
3693 exit when No (Discr);
3696 Set_Last_Entity (Der_Base, Last_Discr);
3698 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
3699 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
3702 -- If this is a completion, the derived type stays private
3703 -- and there is no need to create a further full view, except
3704 -- in the unusual case when the derivation is nested within a
3705 -- child unit, see below.
3710 elsif Present (Full_View (Parent_Type))
3711 and then Has_Discriminants (Full_View (Parent_Type))
3713 if Has_Unknown_Discriminants (Parent_Type)
3714 and then Nkind (Subtype_Indication (Type_Definition (N)))
3715 = N_Subtype_Indication
3718 ("cannot constrain type with unknown discriminants",
3719 Subtype_Indication (Type_Definition (N)));
3723 -- Inherit the discriminants of the full view, but
3724 -- keep the proper parent type.
3726 -- ??? this looks wrong, we are replacing (and thus,
3727 -- erasing) the partial view!
3729 -- In any case, the primitive operations are inherited from
3730 -- the parent type, not from the internal full view.
3732 Build_Derived_Record_Type
3733 (N, Full_View (Parent_Type), Derived_Type,
3734 Derive_Subps => False);
3735 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
3737 if Derive_Subps then
3738 Derive_Subprograms (Parent_Type, Derived_Type);
3743 -- Untagged type, No discriminants on either view.
3745 if Nkind (Subtype_Indication (Type_Definition (N)))
3746 = N_Subtype_Indication
3749 ("illegal constraint on type without discriminants", N);
3752 if Present (Discriminant_Specifications (N))
3753 and then Present (Full_View (Parent_Type))
3754 and then not Is_Tagged_Type (Full_View (Parent_Type))
3757 ("cannot add discriminants to untagged type", N);
3760 Set_Girder_Constraint (Derived_Type, No_Elist);
3761 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3762 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
3763 Set_Has_Controlled_Component (Derived_Type,
3764 Has_Controlled_Component (Parent_Type));
3766 -- Direct controlled types do not inherit the Finalize_Storage_Only
3769 if not Is_Controlled (Parent_Type) then
3770 Set_Finalize_Storage_Only (Derived_Type,
3771 Finalize_Storage_Only (Parent_Type));
3774 -- Construct the implicit full view by deriving from full
3775 -- view of the parent type. In order to get proper visiblity,
3776 -- we install the parent scope and its declarations.
3778 -- ??? if the parent is untagged private and its
3779 -- completion is tagged, this mechanism will not
3780 -- work because we cannot derive from the tagged
3781 -- full view unless we have an extension
3783 if Present (Full_View (Parent_Type))
3784 and then not Is_Tagged_Type (Full_View (Parent_Type))
3785 and then not Is_Completion
3787 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
3788 Chars (Derived_Type));
3789 Set_Is_Itype (Full_Der);
3790 Set_Has_Private_Declaration (Full_Der);
3791 Set_Has_Private_Declaration (Derived_Type);
3792 Set_Associated_Node_For_Itype (Full_Der, N);
3793 Set_Parent (Full_Der, Parent (Derived_Type));
3794 Set_Full_View (Derived_Type, Full_Der);
3796 if not In_Open_Scopes (Par_Scope) then
3797 Install_Private_Declarations (Par_Scope);
3798 Install_Visible_Declarations (Par_Scope);
3800 Uninstall_Declarations (Par_Scope);
3802 -- If parent scope is open and in another unit, and
3803 -- parent has a completion, then the derivation is taking
3804 -- place in the visible part of a child unit. In that
3805 -- case retrieve the full view of the parent momentarily.
3807 elsif not In_Same_Source_Unit (N, Parent_Type) then
3808 Full_P := Full_View (Parent_Type);
3809 Exchange_Declarations (Parent_Type);
3811 Exchange_Declarations (Full_P);
3813 -- Otherwise it is a local derivation.
3819 Set_Scope (Full_Der, Current_Scope);
3820 Set_Is_First_Subtype (Full_Der,
3821 Is_First_Subtype (Derived_Type));
3822 Set_Has_Size_Clause (Full_Der, False);
3823 Set_Has_Alignment_Clause (Full_Der, False);
3824 Set_Next_Entity (Full_Der, Empty);
3825 Set_Has_Delayed_Freeze (Full_Der);
3826 Set_Is_Frozen (Full_Der, False);
3827 Set_Freeze_Node (Full_Der, Empty);
3828 Set_Depends_On_Private (Full_Der,
3829 Has_Private_Component (Full_Der));
3830 Set_Public_Status (Full_Der);
3834 Set_Has_Unknown_Discriminants (Derived_Type,
3835 Has_Unknown_Discriminants (Parent_Type));
3837 if Is_Private_Type (Derived_Type) then
3838 Set_Private_Dependents (Derived_Type, New_Elmt_List);
3841 if Is_Private_Type (Parent_Type)
3842 and then Base_Type (Parent_Type) = Parent_Type
3843 and then In_Open_Scopes (Scope (Parent_Type))
3845 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
3847 if Is_Child_Unit (Scope (Current_Scope))
3848 and then Is_Completion
3849 and then In_Private_Part (Current_Scope)
3851 -- This is the unusual case where a type completed by a private
3852 -- derivation occurs within a package nested in a child unit,
3853 -- and the parent is declared in an ancestor. In this case, the
3854 -- full view of the parent type will become visible in the body
3855 -- of the enclosing child, and only then will the current type
3856 -- be possibly non-private. We build a underlying full view that
3857 -- will be installed when the enclosing child body is compiled.
3860 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
3864 Make_Defining_Identifier (Sloc (Derived_Type),
3865 Chars (Derived_Type));
3866 Set_Is_Itype (Full_Der);
3867 Set_Itype (IR, Full_Der);
3868 Insert_After (N, IR);
3870 -- The full view will be used to swap entities on entry/exit
3871 -- to the body, and must appear in the entity list for the
3874 Append_Entity (Full_Der, Scope (Derived_Type));
3875 Set_Has_Private_Declaration (Full_Der);
3876 Set_Has_Private_Declaration (Derived_Type);
3877 Set_Associated_Node_For_Itype (Full_Der, N);
3878 Set_Parent (Full_Der, Parent (Derived_Type));
3879 Full_P := Full_View (Parent_Type);
3880 Exchange_Declarations (Parent_Type);
3882 Exchange_Declarations (Full_P);
3883 Set_Underlying_Full_View (Derived_Type, Full_Der);
3887 end Build_Derived_Private_Type;
3889 -------------------------------
3890 -- Build_Derived_Record_Type --
3891 -------------------------------
3895 -- Ideally we would like to use the same model of type derivation for
3896 -- tagged and untagged record types. Unfortunately this is not quite
3897 -- possible because the semantics of representation clauses is different
3898 -- for tagged and untagged records under inheritance. Consider the
3901 -- type R (...) is [tagged] record ... end record;
3902 -- type T (...) is new R (...) [with ...];
3904 -- The representation clauses of T can specify a completely different
3905 -- record layout from R's. Hence a same component can be placed in two very
3906 -- different positions in objects of type T and R. If R and T are tagged
3907 -- types, representation clauses for T can only specify the layout of non
3908 -- inherited components, thus components that are common in R and T have
3909 -- the same position in objects of type R or T.
3911 -- This has two implications. The first is that the entire tree for R's
3912 -- declaration needs to be copied for T in the untagged case, so that
3913 -- T can be viewd as a record type of its own with its own derivation
3914 -- clauses. The second implication is the way we handle discriminants.
3915 -- Specifically, in the untagged case we need a way to communicate to Gigi
3916 -- what are the real discriminants in the record, while for the semantics
3917 -- we need to consider those introduced by the user to rename the
3918 -- discriminants in the parent type. This is handled by introducing the
3919 -- notion of girder discriminants. See below for more.
3921 -- Fortunately the way regular components are inherited can be handled in
3922 -- the same way in tagged and untagged types.
3924 -- To complicate things a bit more the private view of a private extension
3925 -- cannot be handled in the same way as the full view (for one thing the
3926 -- semantic rules are somewhat different). We will explain what differs
3929 -- 2. DISCRIMINANTS UNDER INHERITANCE.
3931 -- The semantic rules governing the discriminants of derived types are
3934 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
3935 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
3937 -- If parent type has discriminants, then the discriminants that are
3938 -- declared in the derived type are [3.4 (11)]:
3940 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
3943 -- o Otherwise, each discriminant of the parent type (implicitely
3944 -- declared in the same order with the same specifications). In this
3945 -- case, the discriminants are said to be "inherited", or if unknown in
3946 -- the parent are also unknown in the derived type.
3948 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
3950 -- o The parent subtype shall be constrained;
3952 -- o If the parent type is not a tagged type, then each discriminant of
3953 -- the derived type shall be used in the constraint defining a parent
3954 -- subtype [Implementation note: this ensures that the new discriminant
3955 -- can share storage with an existing discriminant.].
3957 -- For the derived type each discriminant of the parent type is either
3958 -- inherited, constrained to equal some new discriminant of the derived
3959 -- type, or constrained to the value of an expression.
3961 -- When inherited or constrained to equal some new discriminant, the
3962 -- parent discriminant and the discriminant of the derived type are said
3965 -- If a discriminant of the parent type is constrained to a specific value
3966 -- in the derived type definition, then the discriminant is said to be
3967 -- "specified" by that derived type definition.
3969 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
3971 -- We have spoken about girder discriminants in the point 1 (introduction)
3972 -- above. There are two sort of girder discriminants: implicit and
3973 -- explicit. As long as the derived type inherits the same discriminants as
3974 -- the root record type, girder discriminants are the same as regular
3975 -- discriminants, and are said to be implicit. However, if any discriminant
3976 -- in the root type was renamed in the derived type, then the derived
3977 -- type will contain explicit girder discriminants. Explicit girder
3978 -- discriminants are discriminants in addition to the semantically visible
3979 -- discriminants defined for the derived type. Girder discriminants are
3980 -- used by Gigi to figure out what are the physical discriminants in
3981 -- objects of the derived type (see precise definition in einfo.ads).
3982 -- As an example, consider the following:
3984 -- type R (D1, D2, D3 : Int) is record ... end record;
3985 -- type T1 is new R;
3986 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
3987 -- type T3 is new T2;
3988 -- type T4 (Y : Int) is new T3 (Y, 99);
3990 -- The following table summarizes the discriminants and girder
3991 -- discriminants in R and T1 through T4.
3993 -- Type Discrim Girder Discrim Comment
3994 -- R (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in R
3995 -- T1 (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in T1
3996 -- T2 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T2
3997 -- T3 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T3
3998 -- T4 (Y) (D1, D2, D3) Gider discrims are EXPLICIT in T4
4000 -- Field Corresponding_Discriminant (abbreviated CD below) allows to find
4001 -- the corresponding discriminant in the parent type, while
4002 -- Original_Record_Component (abbreviated ORC below), the actual physical
4003 -- component that is renamed. Finally the field Is_Completely_Hidden
4004 -- (abbreaviated ICH below) is set for all explicit girder discriminants
4005 -- (see einfo.ads for more info). For the above example this gives:
4007 -- Discrim CD ORC ICH
4008 -- ^^^^^^^ ^^ ^^^ ^^^
4009 -- D1 in R empty itself no
4010 -- D2 in R empty itself no
4011 -- D3 in R empty itself no
4013 -- D1 in T1 D1 in R itself no
4014 -- D2 in T1 D2 in R itself no
4015 -- D3 in T1 D3 in R itself no
4017 -- X1 in T2 D3 in T1 D3 in T2 no
4018 -- X2 in T2 D1 in T1 D1 in T2 no
4019 -- D1 in T2 empty itself yes
4020 -- D2 in T2 empty itself yes
4021 -- D3 in T2 empty itself yes
4023 -- X1 in T3 X1 in T2 D3 in T3 no
4024 -- X2 in T3 X2 in T2 D1 in T3 no
4025 -- D1 in T3 empty itself yes
4026 -- D2 in T3 empty itself yes
4027 -- D3 in T3 empty itself yes
4029 -- Y in T4 X1 in T3 D3 in T3 no
4030 -- D1 in T3 empty itself yes
4031 -- D2 in T3 empty itself yes
4032 -- D3 in T3 empty itself yes
4034 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
4036 -- Type derivation for tagged types is fairly straightforward. if no
4037 -- discriminants are specified by the derived type, these are inherited
4038 -- from the parent. No explicit girder discriminants are ever necessary.
4039 -- The only manipulation that is done to the tree is that of adding a
4040 -- _parent field with parent type and constrained to the same constraint
4041 -- specified for the parent in the derived type definition. For instance:
4043 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
4044 -- type T1 is new R with null record;
4045 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
4047 -- are changed into :
4049 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
4050 -- _parent : R (D1, D2, D3);
4053 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
4054 -- _parent : T1 (X2, 88, X1);
4057 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4058 -- ORC and ICH fields are:
4060 -- Discrim CD ORC ICH
4061 -- ^^^^^^^ ^^ ^^^ ^^^
4062 -- D1 in R empty itself no
4063 -- D2 in R empty itself no
4064 -- D3 in R empty itself no
4066 -- D1 in T1 D1 in R D1 in R no
4067 -- D2 in T1 D2 in R D2 in R no
4068 -- D3 in T1 D3 in R D3 in R no
4070 -- X1 in T2 D3 in T1 D3 in R no
4071 -- X2 in T2 D1 in T1 D1 in R no
4073 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
4075 -- Regardless of whether we dealing with a tagged or untagged type
4076 -- we will transform all derived type declarations of the form
4078 -- type T is new R (...) [with ...];
4080 -- subtype S is R (...);
4081 -- type T is new S [with ...];
4083 -- type BT is new R [with ...];
4084 -- subtype T is BT (...);
4086 -- That is, the base derived type is constrained only if it has no
4087 -- discriminants. The reason for doing this is that GNAT's semantic model
4088 -- assumes that a base type with discriminants is unconstrained.
4090 -- Note that, strictly speaking, the above transformation is not always
4091 -- correct. Consider for instance the following exercpt from ACVC b34011a:
4093 -- procedure B34011A is
4094 -- type REC (D : integer := 0) is record
4099 -- type T6 is new Rec;
4100 -- function F return T6;
4105 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4108 -- The definition of Q6.U is illegal. However transforming Q6.U into
4110 -- type BaseU is new T6;
4111 -- subtype U is BaseU (Q6.F.I)
4113 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4114 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4115 -- the transformation described above.
4117 -- There is another instance where the above transformation is incorrect.
4121 -- type Base (D : Integer) is tagged null record;
4122 -- procedure P (X : Base);
4124 -- type Der is new Base (2) with null record;
4125 -- procedure P (X : Der);
4128 -- Then the above transformation turns this into
4130 -- type Der_Base is new Base with null record;
4131 -- -- procedure P (X : Base) is implicitely inherited here
4132 -- -- as procedure P (X : Der_Base).
4134 -- subtype Der is Der_Base (2);
4135 -- procedure P (X : Der);
4136 -- -- The overriding of P (X : Der_Base) is illegal since we
4137 -- -- have a parameter conformance problem.
4139 -- To get around this problem, after having semantically processed Der_Base
4140 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4141 -- Discriminant_Constraint from Der so that when parameter conformance is
4142 -- checked when P is overridden, no sematic errors are flagged.
4144 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
4146 -- Regardless of the fact that we dealing with a tagged or untagged type
4147 -- we will transform all derived type declarations of the form
4149 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4150 -- type T is new R [with ...];
4152 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4154 -- The reason for such transformation is that it allows us to implement a
4155 -- very clean form of component inheritance as explained below.
4157 -- Note that this transformation is not achieved by direct tree rewriting
4158 -- and manipulation, but rather by redoing the semantic actions that the
4159 -- above transformation will entail. This is done directly in routine
4160 -- Inherit_Components.
4162 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
4164 -- In both tagged and untagged derived types, regular non discriminant
4165 -- components are inherited in the derived type from the parent type. In
4166 -- the absence of discriminants component, inheritance is straightforward
4167 -- as components can simply be copied from the parent.
4168 -- If the parent has discriminants, inheriting components constrained with
4169 -- these discriminants requires caution. Consider the following example:
4171 -- type R (D1, D2 : Positive) is [tagged] record
4172 -- S : String (D1 .. D2);
4175 -- type T1 is new R [with null record];
4176 -- type T2 (X : positive) is new R (1, X) [with null record];
4178 -- As explained in 6. above, T1 is rewritten as
4180 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4182 -- which makes the treatment for T1 and T2 identical.
4184 -- What we want when inheriting S, is that references to D1 and D2 in R are
4185 -- replaced with references to their correct constraints, ie D1 and D2 in
4186 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4187 -- with either discriminant references in the derived type or expressions.
4188 -- This replacement is acheived as follows: before inheriting R's
4189 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4190 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4191 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4192 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4193 -- by String (1 .. X).
4195 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
4197 -- We explain here the rules governing private type extensions relevant to
4198 -- type derivation. These rules are explained on the following example:
4200 -- type D [(...)] is new A [(...)] with private; <-- partial view
4201 -- type D [(...)] is new P [(...)] with null record; <-- full view
4203 -- Type A is called the ancestor subtype of the private extension.
4204 -- Type P is the parent type of the full view of the private extension. It
4205 -- must be A or a type derived from A.
4207 -- The rules concerning the discriminants of private type extensions are
4210 -- o If a private extension inherits known discriminants from the ancestor
4211 -- subtype, then the full view shall also inherit its discriminants from
4212 -- the ancestor subtype and the parent subtype of the full view shall be
4213 -- constrained if and only if the ancestor subtype is constrained.
4215 -- o If a partial view has unknown discriminants, then the full view may
4216 -- define a definite or an indefinite subtype, with or without
4219 -- o If a partial view has neither known nor unknown discriminants, then
4220 -- the full view shall define a definite subtype.
4222 -- o If the ancestor subtype of a private extension has constrained
4223 -- discrimiants, then the parent subtype of the full view shall impose a
4224 -- statically matching constraint on those discriminants.
4226 -- This means that only the following forms of private extensions are
4229 -- type D is new A with private; <-- partial view
4230 -- type D is new P with null record; <-- full view
4232 -- If A has no discriminants than P has no discriminants, otherwise P must
4233 -- inherit A's discriminants.
4235 -- type D is new A (...) with private; <-- partial view
4236 -- type D is new P (:::) with null record; <-- full view
4238 -- P must inherit A's discriminants and (...) and (:::) must statically
4241 -- subtype A is R (...);
4242 -- type D is new A with private; <-- partial view
4243 -- type D is new P with null record; <-- full view
4245 -- P must have inherited R's discriminants and must be derived from A or
4246 -- any of its subtypes.
4248 -- type D (..) is new A with private; <-- partial view
4249 -- type D (..) is new P [(:::)] with null record; <-- full view
4251 -- No specific constraints on P's discriminants or constraint (:::).
4252 -- Note that A can be unconstrained, but the parent subtype P must either
4253 -- be constrained or (:::) must be present.
4255 -- type D (..) is new A [(...)] with private; <-- partial view
4256 -- type D (..) is new P [(:::)] with null record; <-- full view
4258 -- P's constraints on A's discriminants must statically match those
4259 -- imposed by (...).
4261 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
4263 -- The full view of a private extension is handled exactly as described
4264 -- above. The model chose for the private view of a private extension
4265 -- is the same for what concerns discriminants (ie they receive the same
4266 -- treatment as in the tagged case). However, the private view of the
4267 -- private extension always inherits the components of the parent base,
4268 -- without replacing any discriminant reference. Strictly speacking this
4269 -- is incorrect. However, Gigi never uses this view to generate code so
4270 -- this is a purely semantic issue. In theory, a set of transformations
4271 -- similar to those given in 5. and 6. above could be applied to private
4272 -- views of private extensions to have the same model of component
4273 -- inheritance as for non private extensions. However, this is not done
4274 -- because it would further complicate private type processing.
4275 -- Semantically speaking, this leaves us in an uncomfortable
4276 -- situation. As an example consider:
4279 -- type R (D : integer) is tagged record
4280 -- S : String (1 .. D);
4282 -- procedure P (X : R);
4283 -- type T is new R (1) with private;
4285 -- type T is new R (1) with null record;
4288 -- This is transformed into:
4291 -- type R (D : integer) is tagged record
4292 -- S : String (1 .. D);
4294 -- procedure P (X : R);
4295 -- type T is new R (1) with private;
4297 -- type BaseT is new R with null record;
4298 -- subtype T is BaseT (1);
4301 -- (strictly speaking the above is incorrect Ada).
4303 -- From the semantic standpoint the private view of private extension T
4304 -- should be flagged as constrained since one can clearly have
4308 -- in a unit withing Pack. However, when deriving subprograms for the
4309 -- private view of private extension T, T must be seen as unconstrained
4310 -- since T has discriminants (this is a constraint of the current
4311 -- subprogram derivation model). Thus, when processing the private view of
4312 -- a private extension such as T, we first mark T as unconstrained, we
4313 -- process it, we perform program derivation and just before returning from
4314 -- Build_Derived_Record_Type we mark T as constrained.
4315 -- ??? Are there are other unconfortable cases that we will have to
4318 -- 10. RECORD_TYPE_WITH_PRIVATE complications.
4320 -- Types that are derived from a visible record type and have a private
4321 -- extension present other peculiarities. They behave mostly like private
4322 -- types, but if they have primitive operations defined, these will not
4323 -- have the proper signatures for further inheritance, because other
4324 -- primitive operations will use the implicit base that we define for
4325 -- private derivations below. This affect subprogram inheritance (see
4326 -- Derive_Subprograms for details). We also derive the implicit base from
4327 -- the base type of the full view, so that the implicit base is a record
4328 -- type and not another private type, This avoids infinite loops.
4330 procedure Build_Derived_Record_Type
4332 Parent_Type : Entity_Id;
4333 Derived_Type : Entity_Id;
4334 Derive_Subps : Boolean := True)
4336 Loc : constant Source_Ptr := Sloc (N);
4337 Parent_Base : Entity_Id;
4342 Discrim : Entity_Id;
4343 Last_Discrim : Entity_Id;
4345 Discs : Elist_Id := New_Elmt_List;
4346 -- An empty Discs list means that there were no constraints in the
4347 -- subtype indication or that there was an error processing it.
4349 Assoc_List : Elist_Id;
4350 New_Discrs : Elist_Id;
4352 New_Base : Entity_Id;
4354 New_Indic : Node_Id;
4356 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4357 Discriminant_Specs : constant Boolean
4358 := Present (Discriminant_Specifications (N));
4359 Private_Extension : constant Boolean
4360 := (Nkind (N) = N_Private_Extension_Declaration);
4362 Constraint_Present : Boolean;
4363 Inherit_Discrims : Boolean := False;
4365 Save_Etype : Entity_Id;
4366 Save_Discr_Constr : Elist_Id;
4367 Save_Next_Entity : Entity_Id;
4370 if Ekind (Parent_Type) = E_Record_Type_With_Private
4371 and then Present (Full_View (Parent_Type))
4372 and then Has_Discriminants (Parent_Type)
4374 Parent_Base := Base_Type (Full_View (Parent_Type));
4376 Parent_Base := Base_Type (Parent_Type);
4379 -- Before we start the previously documented transformations, here is
4380 -- a little fix for size and alignment of tagged types. Normally when
4381 -- we derive type D from type P, we copy the size and alignment of P
4382 -- as the default for D, and in the absence of explicit representation
4383 -- clauses for D, the size and alignment are indeed the same as the
4386 -- But this is wrong for tagged types, since fields may be added,
4387 -- and the default size may need to be larger, and the default
4388 -- alignment may need to be larger.
4390 -- We therefore reset the size and alignment fields in the tagged
4391 -- case. Note that the size and alignment will in any case be at
4392 -- least as large as the parent type (since the derived type has
4393 -- a copy of the parent type in the _parent field)
4396 Init_Size_Align (Derived_Type);
4399 -- STEP 0a: figure out what kind of derived type declaration we have.
4401 if Private_Extension then
4403 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4406 Type_Def := Type_Definition (N);
4408 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4409 -- Parent_Base can be a private type or private extension. However,
4410 -- for tagged types with an extension the newly added fields are
4411 -- visible and hence the Derived_Type is always an E_Record_Type.
4412 -- (except that the parent may have its own private fields).
4413 -- For untagged types we preserve the Ekind of the Parent_Base.
4415 if Present (Record_Extension_Part (Type_Def)) then
4416 Set_Ekind (Derived_Type, E_Record_Type);
4418 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4422 -- Indic can either be an N_Identifier if the subtype indication
4423 -- contains no constraint or an N_Subtype_Indication if the subtype
4424 -- indication has a constraint.
4426 Indic := Subtype_Indication (Type_Def);
4427 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
4429 if Constraint_Present then
4430 if not Has_Discriminants (Parent_Base) then
4432 ("invalid constraint: type has no discriminant",
4433 Constraint (Indic));
4435 Constraint_Present := False;
4436 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4438 elsif Is_Constrained (Parent_Type) then
4440 ("invalid constraint: parent type is already constrained",
4441 Constraint (Indic));
4443 Constraint_Present := False;
4444 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4448 -- STEP 0b: If needed, apply transformation given in point 5. above.
4450 if not Private_Extension
4451 and then Has_Discriminants (Parent_Type)
4452 and then not Discriminant_Specs
4453 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
4455 -- First, we must analyze the constraint (see comment in point 5.).
4457 if Constraint_Present then
4458 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
4460 if Has_Discriminants (Derived_Type)
4461 and then Has_Private_Declaration (Derived_Type)
4462 and then Present (Discriminant_Constraint (Derived_Type))
4464 -- Verify that constraints of the full view conform to those
4465 -- given in partial view.
4471 C1 := First_Elmt (New_Discrs);
4472 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
4474 while Present (C1) and then Present (C2) loop
4476 Fully_Conformant_Expressions (Node (C1), Node (C2))
4479 "constraint not conformant to previous declaration",
4489 -- Insert and analyze the declaration for the unconstrained base type
4491 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
4494 Make_Full_Type_Declaration (Loc,
4495 Defining_Identifier => New_Base,
4497 Make_Derived_Type_Definition (Loc,
4498 Abstract_Present => Abstract_Present (Type_Def),
4499 Subtype_Indication =>
4500 New_Occurrence_Of (Parent_Base, Loc),
4501 Record_Extension_Part =>
4502 Relocate_Node (Record_Extension_Part (Type_Def))));
4504 Set_Parent (New_Decl, Parent (N));
4505 Mark_Rewrite_Insertion (New_Decl);
4506 Insert_Before (N, New_Decl);
4508 -- Note that this call passes False for the Derive_Subps
4509 -- parameter because subprogram derivation is deferred until
4510 -- after creating the subtype (see below).
4513 (New_Decl, Parent_Base, New_Base,
4514 Is_Completion => True, Derive_Subps => False);
4516 -- ??? This needs re-examination to determine whether the
4517 -- above call can simply be replaced by a call to Analyze.
4519 Set_Analyzed (New_Decl);
4521 -- Insert and analyze the declaration for the constrained subtype
4523 if Constraint_Present then
4525 Make_Subtype_Indication (Loc,
4526 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4527 Constraint => Relocate_Node (Constraint (Indic)));
4532 Constr_List : List_Id := New_List;
4536 C := First_Elmt (Discriminant_Constraint (Parent_Type));
4537 while Present (C) loop
4540 -- It is safe here to call New_Copy_Tree since
4541 -- Force_Evaluation was called on each constraint in
4542 -- Build_Discriminant_Constraints.
4544 Append (New_Copy_Tree (Expr), To => Constr_List);
4550 Make_Subtype_Indication (Loc,
4551 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4553 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
4558 Make_Subtype_Declaration (Loc,
4559 Defining_Identifier => Derived_Type,
4560 Subtype_Indication => New_Indic));
4564 -- Derivation of subprograms must be delayed until the
4565 -- full subtype has been established to ensure proper
4566 -- overriding of subprograms inherited by full types.
4567 -- If the derivations occurred as part of the call to
4568 -- Build_Derived_Type above, then the check for type
4569 -- conformance would fail because earlier primitive
4570 -- subprograms could still refer to the full type prior
4571 -- the change to the new subtype and hence wouldn't
4572 -- match the new base type created here.
4574 Derive_Subprograms (Parent_Type, Derived_Type);
4576 -- For tagged types the Discriminant_Constraint of the new base itype
4577 -- is inherited from the first subtype so that no subtype conformance
4578 -- problem arise when the first subtype overrides primitive
4579 -- operations inherited by the implicit base type.
4582 Set_Discriminant_Constraint
4583 (New_Base, Discriminant_Constraint (Derived_Type));
4589 -- If we get here Derived_Type will have no discriminants or it will be
4590 -- a discriminated unconstrained base type.
4592 -- STEP 1a: perform preliminary actions/checks for derived tagged types
4595 -- The parent type is frozen for non-private extensions (RM 13.14(7))
4597 if not Private_Extension then
4598 Freeze_Before (N, Parent_Type);
4601 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
4602 and then not Is_Generic_Type (Derived_Type)
4604 if Is_Controlled (Parent_Type) then
4606 ("controlled type must be declared at the library level",
4610 ("type extension at deeper accessibility level than parent",
4616 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
4620 and then GB /= Enclosing_Generic_Body (Parent_Base)
4623 ("parent type must not be outside generic body",
4630 -- STEP 1b : preliminary cleanup of the full view of private types
4632 -- If the type is already marked as having discriminants, then it's the
4633 -- completion of a private type or private extension and we need to
4634 -- retain the discriminants from the partial view if the current
4635 -- declaration has Discriminant_Specifications so that we can verify
4636 -- conformance. However, we must remove any existing components that
4637 -- were inherited from the parent (and attached in Copy_Private_To_Full)
4638 -- because the full type inherits all appropriate components anyway, and
4639 -- we don't want the partial view's components interfering.
4641 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
4642 Discrim := First_Discriminant (Derived_Type);
4644 Last_Discrim := Discrim;
4645 Next_Discriminant (Discrim);
4646 exit when No (Discrim);
4649 Set_Last_Entity (Derived_Type, Last_Discrim);
4651 -- In all other cases wipe out the list of inherited components (even
4652 -- inherited discriminants), it will be properly rebuilt here.
4655 Set_First_Entity (Derived_Type, Empty);
4656 Set_Last_Entity (Derived_Type, Empty);
4659 -- STEP 1c: Initialize some flags for the Derived_Type
4661 -- The following flags must be initialized here so that
4662 -- Process_Discriminants can check that discriminants of tagged types
4663 -- do not have a default initial value and that access discriminants
4664 -- are only specified for limited records. For completeness, these
4665 -- flags are also initialized along with all the other flags below.
4667 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4668 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
4670 -- STEP 2a: process discriminants of derived type if any.
4672 New_Scope (Derived_Type);
4674 if Discriminant_Specs then
4675 Set_Has_Unknown_Discriminants (Derived_Type, False);
4677 -- The following call initializes fields Has_Discriminants and
4678 -- Discriminant_Constraint, unless we are processing the completion
4679 -- of a private type declaration.
4681 Check_Or_Process_Discriminants (N, Derived_Type);
4683 -- For non-tagged types the constraint on the Parent_Type must be
4684 -- present and is used to rename the discriminants.
4686 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
4687 Error_Msg_N ("untagged parent must have discriminants", Indic);
4689 elsif not Is_Tagged and then not Constraint_Present then
4691 ("discriminant constraint needed for derived untagged records",
4694 -- Otherwise the parent subtype must be constrained unless we have a
4695 -- private extension.
4697 elsif not Constraint_Present
4698 and then not Private_Extension
4699 and then not Is_Constrained (Parent_Type)
4702 ("unconstrained type not allowed in this context", Indic);
4704 elsif Constraint_Present then
4705 -- The following call sets the field Corresponding_Discriminant
4706 -- for the discriminants in the Derived_Type.
4708 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
4710 -- For untagged types all new discriminants must rename
4711 -- discriminants in the parent. For private extensions new
4712 -- discriminants cannot rename old ones (implied by [7.3(13)]).
4714 Discrim := First_Discriminant (Derived_Type);
4716 while Present (Discrim) loop
4718 and then not Present (Corresponding_Discriminant (Discrim))
4721 ("new discriminants must constrain old ones", Discrim);
4723 elsif Private_Extension
4724 and then Present (Corresponding_Discriminant (Discrim))
4727 ("Only static constraints allowed for parent"
4728 & " discriminants in the partial view", Indic);
4733 -- If a new discriminant is used in the constraint,
4734 -- then its subtype must be statically compatible
4735 -- with the parent discriminant's subtype (3.7(15)).
4737 if Present (Corresponding_Discriminant (Discrim))
4739 not Subtypes_Statically_Compatible
4741 Etype (Corresponding_Discriminant (Discrim)))
4744 ("subtype must be compatible with parent discriminant",
4748 Next_Discriminant (Discrim);
4752 -- STEP 2b: No new discriminants, inherit discriminants if any
4755 if Private_Extension then
4756 Set_Has_Unknown_Discriminants
4757 (Derived_Type, Has_Unknown_Discriminants (Parent_Type)
4758 or else Unknown_Discriminants_Present (N));
4760 Set_Has_Unknown_Discriminants
4761 (Derived_Type, Has_Unknown_Discriminants (Parent_Type));
4764 if not Has_Unknown_Discriminants (Derived_Type)
4765 and then Has_Discriminants (Parent_Type)
4767 Inherit_Discrims := True;
4768 Set_Has_Discriminants
4769 (Derived_Type, True);
4770 Set_Discriminant_Constraint
4771 (Derived_Type, Discriminant_Constraint (Parent_Base));
4774 -- The following test is true for private types (remember
4775 -- transformation 5. is not applied to those) and in an error
4778 if Constraint_Present then
4779 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
4782 -- For now mark a new derived type as cosntrained only if it has no
4783 -- discriminants. At the end of Build_Derived_Record_Type we properly
4784 -- set this flag in the case of private extensions. See comments in
4785 -- point 9. just before body of Build_Derived_Record_Type.
4789 not (Inherit_Discrims
4790 or else Has_Unknown_Discriminants (Derived_Type)));
4793 -- STEP 3: initialize fields of derived type.
4795 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4796 Set_Girder_Constraint (Derived_Type, No_Elist);
4798 -- Fields inherited from the Parent_Type
4801 (Derived_Type, Einfo.Discard_Names (Parent_Type));
4802 Set_Has_Specified_Layout
4803 (Derived_Type, Has_Specified_Layout (Parent_Type));
4804 Set_Is_Limited_Composite
4805 (Derived_Type, Is_Limited_Composite (Parent_Type));
4806 Set_Is_Limited_Record
4807 (Derived_Type, Is_Limited_Record (Parent_Type));
4808 Set_Is_Private_Composite
4809 (Derived_Type, Is_Private_Composite (Parent_Type));
4811 -- Fields inherited from the Parent_Base
4813 Set_Has_Controlled_Component
4814 (Derived_Type, Has_Controlled_Component (Parent_Base));
4815 Set_Has_Non_Standard_Rep
4816 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4817 Set_Has_Primitive_Operations
4818 (Derived_Type, Has_Primitive_Operations (Parent_Base));
4820 -- Direct controlled types do not inherit the Finalize_Storage_Only
4823 if not Is_Controlled (Parent_Type) then
4824 Set_Finalize_Storage_Only (Derived_Type,
4825 Finalize_Storage_Only (Parent_Type));
4828 -- Set fields for private derived types.
4830 if Is_Private_Type (Derived_Type) then
4831 Set_Depends_On_Private (Derived_Type, True);
4832 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4834 -- Inherit fields from non private record types. If this is the
4835 -- completion of a derivation from a private type, the parent itself
4836 -- is private, and the attributes come from its full view, which must
4840 if Is_Private_Type (Parent_Base)
4841 and then not Is_Record_Type (Parent_Base)
4843 Set_Component_Alignment
4844 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
4846 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
4848 Set_Component_Alignment
4849 (Derived_Type, Component_Alignment (Parent_Base));
4852 (Derived_Type, C_Pass_By_Copy (Parent_Base));
4856 -- Set fields for tagged types.
4859 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
4861 -- All tagged types defined in Ada.Finalization are controlled
4863 if Chars (Scope (Derived_Type)) = Name_Finalization
4864 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
4865 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
4867 Set_Is_Controlled (Derived_Type);
4869 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
4872 Make_Class_Wide_Type (Derived_Type);
4873 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
4875 if Has_Discriminants (Derived_Type)
4876 and then Constraint_Present
4878 Set_Girder_Constraint
4879 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4883 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
4884 Set_Has_Non_Standard_Rep
4885 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4888 -- STEP 4: Inherit components from the parent base and constrain them.
4889 -- Apply the second transformation described in point 6. above.
4891 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
4892 or else not Has_Discriminants (Parent_Type)
4893 or else not Is_Constrained (Parent_Type)
4897 Constrs := Discriminant_Constraint (Parent_Type);
4900 Assoc_List := Inherit_Components (N,
4901 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
4903 -- STEP 5a: Copy the parent record declaration for untagged types
4905 if not Is_Tagged then
4907 -- Discriminant_Constraint (Derived_Type) has been properly
4908 -- constructed. Save it and temporarily set it to Empty because we do
4909 -- not want the call to New_Copy_Tree below to mess this list.
4911 if Has_Discriminants (Derived_Type) then
4912 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
4913 Set_Discriminant_Constraint (Derived_Type, No_Elist);
4915 Save_Discr_Constr := No_Elist;
4918 -- Save the Etype field of Derived_Type. It is correctly set now, but
4919 -- the call to New_Copy tree may remap it to point to itself, which
4920 -- is not what we want. Ditto for the Next_Entity field.
4922 Save_Etype := Etype (Derived_Type);
4923 Save_Next_Entity := Next_Entity (Derived_Type);
4925 -- Assoc_List maps all girder discriminants in the Parent_Base to
4926 -- girder discriminants in the Derived_Type. It is fundamental that
4927 -- no types or itypes with discriminants other than the girder
4928 -- discriminants appear in the entities declared inside
4929 -- Derived_Type. Gigi won't like it.
4933 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
4935 -- Restore the fields saved prior to the New_Copy_Tree call
4936 -- and compute the girder constraint.
4938 Set_Etype (Derived_Type, Save_Etype);
4939 Set_Next_Entity (Derived_Type, Save_Next_Entity);
4941 if Has_Discriminants (Derived_Type) then
4942 Set_Discriminant_Constraint
4943 (Derived_Type, Save_Discr_Constr);
4944 Set_Girder_Constraint
4945 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4948 -- Insert the new derived type declaration
4950 Rewrite (N, New_Decl);
4952 -- STEP 5b: Complete the processing for record extensions in generics
4954 -- There is no completion for record extensions declared in the
4955 -- parameter part of a generic, so we need to complete processing for
4956 -- these generic record extensions here. The call to
4957 -- Record_Type_Definition will change the Ekind of the components
4958 -- from E_Void to E_Component.
4960 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
4961 Record_Type_Definition (Empty, Derived_Type);
4963 -- STEP 5c: Process the record extension for non private tagged types.
4965 elsif not Private_Extension then
4966 -- Add the _parent field in the derived type.
4968 Expand_Derived_Record (Derived_Type, Type_Def);
4970 -- Analyze the record extension
4972 Record_Type_Definition
4973 (Record_Extension_Part (Type_Def), Derived_Type);
4978 if Etype (Derived_Type) = Any_Type then
4982 -- Set delayed freeze and then derive subprograms, we need to do
4983 -- this in this order so that derived subprograms inherit the
4984 -- derived freeze if necessary.
4986 Set_Has_Delayed_Freeze (Derived_Type);
4987 if Derive_Subps then
4988 Derive_Subprograms (Parent_Type, Derived_Type);
4991 -- If we have a private extension which defines a constrained derived
4992 -- type mark as constrained here after we have derived subprograms. See
4993 -- comment on point 9. just above the body of Build_Derived_Record_Type.
4995 if Private_Extension and then Inherit_Discrims then
4996 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
4997 Set_Is_Constrained (Derived_Type, True);
4998 Set_Discriminant_Constraint (Derived_Type, Discs);
5000 elsif Is_Constrained (Parent_Type) then
5002 (Derived_Type, True);
5003 Set_Discriminant_Constraint
5004 (Derived_Type, Discriminant_Constraint (Parent_Type));
5008 end Build_Derived_Record_Type;
5010 ------------------------
5011 -- Build_Derived_Type --
5012 ------------------------
5014 procedure Build_Derived_Type
5016 Parent_Type : Entity_Id;
5017 Derived_Type : Entity_Id;
5018 Is_Completion : Boolean;
5019 Derive_Subps : Boolean := True)
5021 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5024 -- Set common attributes
5026 Set_Scope (Derived_Type, Current_Scope);
5028 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5029 Set_Etype (Derived_Type, Parent_Base);
5030 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
5032 Set_Size_Info (Derived_Type, Parent_Type);
5033 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5034 Set_Convention (Derived_Type, Convention (Parent_Type));
5035 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
5037 case Ekind (Parent_Type) is
5038 when Numeric_Kind =>
5039 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
5042 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
5046 | Class_Wide_Kind =>
5047 Build_Derived_Record_Type
5048 (N, Parent_Type, Derived_Type, Derive_Subps);
5051 when Enumeration_Kind =>
5052 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5055 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5057 when Incomplete_Or_Private_Kind =>
5058 Build_Derived_Private_Type
5059 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5061 -- For discriminated types, the derivation includes deriving
5062 -- primitive operations. For others it is done below.
5064 if Is_Tagged_Type (Parent_Type)
5065 or else Has_Discriminants (Parent_Type)
5066 or else (Present (Full_View (Parent_Type))
5067 and then Has_Discriminants (Full_View (Parent_Type)))
5072 when Concurrent_Kind =>
5073 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5076 raise Program_Error;
5079 if Etype (Derived_Type) = Any_Type then
5083 -- Set delayed freeze and then derive subprograms, we need to do
5084 -- this in this order so that derived subprograms inherit the
5085 -- derived freeze if necessary.
5087 Set_Has_Delayed_Freeze (Derived_Type);
5088 if Derive_Subps then
5089 Derive_Subprograms (Parent_Type, Derived_Type);
5092 Set_Has_Primitive_Operations
5093 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5094 end Build_Derived_Type;
5096 -----------------------
5097 -- Build_Discriminal --
5098 -----------------------
5100 procedure Build_Discriminal (Discrim : Entity_Id) is
5101 D_Minal : Entity_Id;
5102 CR_Disc : Entity_Id;
5105 -- A discriminal has the same names as the discriminant.
5107 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5109 Set_Ekind (D_Minal, E_In_Parameter);
5110 Set_Mechanism (D_Minal, Default_Mechanism);
5111 Set_Etype (D_Minal, Etype (Discrim));
5113 Set_Discriminal (Discrim, D_Minal);
5114 Set_Discriminal_Link (D_Minal, Discrim);
5116 -- For task types, build at once the discriminants of the corresponding
5117 -- record, which are needed if discriminants are used in entry defaults
5118 -- and in family bounds.
5120 if Is_Concurrent_Type (Current_Scope)
5121 or else Is_Limited_Type (Current_Scope)
5123 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5125 Set_Ekind (CR_Disc, E_In_Parameter);
5126 Set_Mechanism (CR_Disc, Default_Mechanism);
5127 Set_Etype (CR_Disc, Etype (Discrim));
5128 Set_CR_Discriminant (Discrim, CR_Disc);
5130 end Build_Discriminal;
5132 ------------------------------------
5133 -- Build_Discriminant_Constraints --
5134 ------------------------------------
5136 function Build_Discriminant_Constraints
5139 Derived_Def : Boolean := False)
5142 C : constant Node_Id := Constraint (Def);
5143 Nb_Discr : constant Nat := Number_Discriminants (T);
5144 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5145 -- Saves the expression corresponding to a given discriminant in T.
5147 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5148 -- Return the Position number within array Discr_Expr of a discriminant
5149 -- D within the discriminant list of the discriminated type T.
5155 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5159 Disc := First_Discriminant (T);
5160 for J in Discr_Expr'Range loop
5165 Next_Discriminant (Disc);
5168 -- Note: Since this function is called on discriminants that are
5169 -- known to belong to the discriminated type, falling through the
5170 -- loop with no match signals an internal compiler error.
5172 raise Program_Error;
5175 -- Variables local to Build_Discriminant_Constraints
5179 Elist : Elist_Id := New_Elmt_List;
5187 Discrim_Present : Boolean := False;
5189 -- Start of processing for Build_Discriminant_Constraints
5192 -- The following loop will process positional associations only.
5193 -- For a positional association, the (single) discriminant is
5194 -- implicitly specified by position, in textual order (RM 3.7.2).
5196 Discr := First_Discriminant (T);
5197 Constr := First (Constraints (C));
5199 for D in Discr_Expr'Range loop
5200 exit when Nkind (Constr) = N_Discriminant_Association;
5203 Error_Msg_N ("too few discriminants given in constraint", C);
5204 return New_Elmt_List;
5206 elsif Nkind (Constr) = N_Range
5207 or else (Nkind (Constr) = N_Attribute_Reference
5209 Attribute_Name (Constr) = Name_Range)
5212 ("a range is not a valid discriminant constraint", Constr);
5213 Discr_Expr (D) := Error;
5216 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5217 Discr_Expr (D) := Constr;
5220 Next_Discriminant (Discr);
5224 if No (Discr) and then Present (Constr) then
5225 Error_Msg_N ("too many discriminants given in constraint", Constr);
5226 return New_Elmt_List;
5229 -- Named associations can be given in any order, but if both positional
5230 -- and named associations are used in the same discriminant constraint,
5231 -- then positional associations must occur first, at their normal
5232 -- position. Hence once a named association is used, the rest of the
5233 -- discriminant constraint must use only named associations.
5235 while Present (Constr) loop
5237 -- Positional association forbidden after a named association.
5239 if Nkind (Constr) /= N_Discriminant_Association then
5240 Error_Msg_N ("positional association follows named one", Constr);
5241 return New_Elmt_List;
5243 -- Otherwise it is a named association
5246 -- E records the type of the discriminants in the named
5247 -- association. All the discriminants specified in the same name
5248 -- association must have the same type.
5252 -- Search the list of discriminants in T to see if the simple name
5253 -- given in the constraint matches any of them.
5255 Id := First (Selector_Names (Constr));
5256 while Present (Id) loop
5259 -- If Original_Discriminant is present, we are processing a
5260 -- generic instantiation and this is an instance node. We need
5261 -- to find the name of the corresponding discriminant in the
5262 -- actual record type T and not the name of the discriminant in
5263 -- the generic formal. Example:
5266 -- type G (D : int) is private;
5268 -- subtype W is G (D => 1);
5270 -- type Rec (X : int) is record ... end record;
5271 -- package Q is new P (G => Rec);
5273 -- At the point of the instantiation, formal type G is Rec
5274 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5275 -- which really looks like "subtype W is Rec (D => 1);" at
5276 -- the point of instantiation, we want to find the discriminant
5277 -- that corresponds to D in Rec, ie X.
5279 if Present (Original_Discriminant (Id)) then
5280 Discr := Find_Corresponding_Discriminant (Id, T);
5284 Discr := First_Discriminant (T);
5285 while Present (Discr) loop
5286 if Chars (Discr) = Chars (Id) then
5291 Next_Discriminant (Discr);
5295 Error_Msg_N ("& does not match any discriminant", Id);
5296 return New_Elmt_List;
5298 -- The following is only useful for the benefit of generic
5299 -- instances but it does not interfere with other
5300 -- processing for the non-generic case so we do it in all
5301 -- cases (for generics this statement is executed when
5302 -- processing the generic definition, see comment at the
5303 -- begining of this if statement).
5306 Set_Original_Discriminant (Id, Discr);
5310 Position := Pos_Of_Discr (T, Discr);
5312 if Present (Discr_Expr (Position)) then
5313 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5316 -- Each discriminant specified in the same named association
5317 -- must be associated with a separate copy of the
5318 -- corresponding expression.
5320 if Present (Next (Id)) then
5321 Expr := New_Copy_Tree (Expression (Constr));
5322 Set_Parent (Expr, Parent (Expression (Constr)));
5324 Expr := Expression (Constr);
5327 Discr_Expr (Position) := Expr;
5328 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
5331 -- A discriminant association with more than one discriminant
5332 -- name is only allowed if the named discriminants are all of
5333 -- the same type (RM 3.7.1(8)).
5336 E := Base_Type (Etype (Discr));
5338 elsif Base_Type (Etype (Discr)) /= E then
5340 ("all discriminants in an association " &
5341 "must have the same type", Id);
5351 -- A discriminant constraint must provide exactly one value for each
5352 -- discriminant of the type (RM 3.7.1(8)).
5354 for J in Discr_Expr'Range loop
5355 if No (Discr_Expr (J)) then
5356 Error_Msg_N ("too few discriminants given in constraint", C);
5357 return New_Elmt_List;
5361 -- Determine if there are discriminant expressions in the constraint.
5363 for J in Discr_Expr'Range loop
5364 if Denotes_Discriminant (Discr_Expr (J)) then
5365 Discrim_Present := True;
5369 -- Build an element list consisting of the expressions given in the
5370 -- discriminant constraint and apply the appropriate range
5371 -- checks. The list is constructed after resolving any named
5372 -- discriminant associations and therefore the expressions appear in
5373 -- the textual order of the discriminants.
5375 Discr := First_Discriminant (T);
5376 for J in Discr_Expr'Range loop
5377 if Discr_Expr (J) /= Error then
5379 Append_Elmt (Discr_Expr (J), Elist);
5381 -- If any of the discriminant constraints is given by a
5382 -- discriminant and we are in a derived type declaration we
5383 -- have a discriminant renaming. Establish link between new
5384 -- and old discriminant.
5386 if Denotes_Discriminant (Discr_Expr (J)) then
5388 Set_Corresponding_Discriminant
5389 (Entity (Discr_Expr (J)), Discr);
5392 -- Force the evaluation of non-discriminant expressions.
5393 -- If we have found a discriminant in the constraint 3.4(26)
5394 -- and 3.8(18) demand that no range checks are performed are
5395 -- after evaluation. In all other cases perform a range check.
5398 if not Discrim_Present then
5399 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
5402 Force_Evaluation (Discr_Expr (J));
5405 -- Check that the designated type of an access discriminant's
5406 -- expression is not a class-wide type unless the discriminant's
5407 -- designated type is also class-wide.
5409 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
5410 and then not Is_Class_Wide_Type
5411 (Designated_Type (Etype (Discr)))
5412 and then Etype (Discr_Expr (J)) /= Any_Type
5413 and then Is_Class_Wide_Type
5414 (Designated_Type (Etype (Discr_Expr (J))))
5416 Wrong_Type (Discr_Expr (J), Etype (Discr));
5420 Next_Discriminant (Discr);
5424 end Build_Discriminant_Constraints;
5426 ---------------------------------
5427 -- Build_Discriminated_Subtype --
5428 ---------------------------------
5430 procedure Build_Discriminated_Subtype
5434 Related_Nod : Node_Id;
5435 For_Access : Boolean := False)
5437 Has_Discrs : constant Boolean := Has_Discriminants (T);
5438 Constrained : constant Boolean
5439 := (Has_Discrs and then not Is_Empty_Elmt_List (Elist))
5440 or else Is_Constrained (T);
5443 if Ekind (T) = E_Record_Type then
5445 Set_Ekind (Def_Id, E_Private_Subtype);
5446 Set_Is_For_Access_Subtype (Def_Id, True);
5448 Set_Ekind (Def_Id, E_Record_Subtype);
5451 elsif Ekind (T) = E_Task_Type then
5452 Set_Ekind (Def_Id, E_Task_Subtype);
5454 elsif Ekind (T) = E_Protected_Type then
5455 Set_Ekind (Def_Id, E_Protected_Subtype);
5457 elsif Is_Private_Type (T) then
5458 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
5460 elsif Is_Class_Wide_Type (T) then
5461 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
5464 -- Incomplete type. Attach subtype to list of dependents, to be
5465 -- completed with full view of parent type.
5467 Set_Ekind (Def_Id, Ekind (T));
5468 Append_Elmt (Def_Id, Private_Dependents (T));
5471 Set_Etype (Def_Id, T);
5472 Init_Size_Align (Def_Id);
5473 Set_Has_Discriminants (Def_Id, Has_Discrs);
5474 Set_Is_Constrained (Def_Id, Constrained);
5476 Set_First_Entity (Def_Id, First_Entity (T));
5477 Set_Last_Entity (Def_Id, Last_Entity (T));
5478 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
5480 if Is_Tagged_Type (T) then
5481 Set_Is_Tagged_Type (Def_Id);
5482 Make_Class_Wide_Type (Def_Id);
5485 Set_Girder_Constraint (Def_Id, No_Elist);
5488 Set_Discriminant_Constraint (Def_Id, Elist);
5489 Set_Girder_Constraint_From_Discriminant_Constraint (Def_Id);
5492 if Is_Tagged_Type (T) then
5493 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
5494 Set_Is_Abstract (Def_Id, Is_Abstract (T));
5497 -- Subtypes introduced by component declarations do not need to be
5498 -- marked as delayed, and do not get freeze nodes, because the semantics
5499 -- verifies that the parents of the subtypes are frozen before the
5500 -- enclosing record is frozen.
5502 if not Is_Type (Scope (Def_Id)) then
5503 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
5505 if Is_Private_Type (T)
5506 and then Present (Full_View (T))
5508 Conditional_Delay (Def_Id, Full_View (T));
5510 Conditional_Delay (Def_Id, T);
5514 if Is_Record_Type (T) then
5515 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
5518 and then not Is_Empty_Elmt_List (Elist)
5519 and then not For_Access
5521 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
5522 elsif not For_Access then
5523 Set_Cloned_Subtype (Def_Id, T);
5527 end Build_Discriminated_Subtype;
5529 ------------------------
5530 -- Build_Scalar_Bound --
5531 ------------------------
5533 function Build_Scalar_Bound
5540 New_Bound : Entity_Id;
5543 -- Note: not clear why this is needed, how can the original bound
5544 -- be unanalyzed at this point? and if it is, what business do we
5545 -- have messing around with it? and why is the base type of the
5546 -- parent type the right type for the resolution. It probably is
5547 -- not! It is OK for the new bound we are creating, but not for
5548 -- the old one??? Still if it never happens, no problem!
5550 Analyze_And_Resolve (Bound, Base_Type (Par_T));
5552 if Nkind (Bound) = N_Integer_Literal
5553 or else Nkind (Bound) = N_Real_Literal
5555 New_Bound := New_Copy (Bound);
5556 Set_Etype (New_Bound, Der_T);
5557 Set_Analyzed (New_Bound);
5559 elsif Is_Entity_Name (Bound) then
5560 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
5562 -- The following is almost certainly wrong. What business do we have
5563 -- relocating a node (Bound) that is presumably still attached to
5564 -- the tree elsewhere???
5567 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
5570 Set_Etype (New_Bound, Der_T);
5572 end Build_Scalar_Bound;
5574 --------------------------------
5575 -- Build_Underlying_Full_View --
5576 --------------------------------
5578 procedure Build_Underlying_Full_View
5583 Loc : constant Source_Ptr := Sloc (N);
5584 Subt : constant Entity_Id :=
5585 Make_Defining_Identifier
5586 (Loc, New_External_Name (Chars (Typ), 'S'));
5594 if Nkind (N) = N_Full_Type_Declaration then
5595 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
5597 -- ??? ??? is this assert right, I assume so otherwise Constr
5598 -- would not be defined below (this used to be an elsif)
5600 else pragma Assert (Nkind (N) = N_Subtype_Declaration);
5601 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
5604 -- If the constraint has discriminant associations, the discriminant
5605 -- entity is already set, but it denotes a discriminant of the new
5606 -- type, not the original parent, so it must be found anew.
5608 C := First (Constraints (Constr));
5610 while Present (C) loop
5612 if Nkind (C) = N_Discriminant_Association then
5613 Id := First (Selector_Names (C));
5615 while Present (Id) loop
5616 Set_Original_Discriminant (Id, Empty);
5624 Indic := Make_Subtype_Declaration (Loc,
5625 Defining_Identifier => Subt,
5626 Subtype_Indication =>
5627 Make_Subtype_Indication (Loc,
5628 Subtype_Mark => New_Reference_To (Par, Loc),
5629 Constraint => New_Copy_Tree (Constr)));
5631 Insert_Before (N, Indic);
5633 Set_Underlying_Full_View (Typ, Full_View (Subt));
5634 end Build_Underlying_Full_View;
5636 -------------------------------
5637 -- Check_Abstract_Overriding --
5638 -------------------------------
5640 procedure Check_Abstract_Overriding (T : Entity_Id) is
5647 Op_List := Primitive_Operations (T);
5649 -- Loop to check primitive operations
5651 Elmt := First_Elmt (Op_List);
5652 while Present (Elmt) loop
5653 Subp := Node (Elmt);
5655 -- Special exception, do not complain about failure to
5656 -- override _Input and _Output, since we always provide
5657 -- automatic overridings for these subprograms.
5659 if Is_Abstract (Subp)
5660 and then Chars (Subp) /= Name_uInput
5661 and then Chars (Subp) /= Name_uOutput
5662 and then not Is_Abstract (T)
5664 if Present (Alias (Subp)) then
5665 -- Only perform the check for a derived subprogram when
5666 -- the type has an explicit record extension. This avoids
5667 -- incorrectly flagging abstract subprograms for the case
5668 -- of a type without an extension derived from a formal type
5669 -- with a tagged actual (can occur within a private part).
5671 Type_Def := Type_Definition (Parent (T));
5672 if Nkind (Type_Def) = N_Derived_Type_Definition
5673 and then Present (Record_Extension_Part (Type_Def))
5676 ("type must be declared abstract or & overridden",
5681 ("abstract subprogram not allowed for type&",
5684 ("nonabstract type has abstract subprogram&",
5691 end Check_Abstract_Overriding;
5693 ------------------------------------------------
5694 -- Check_Access_Discriminant_Requires_Limited --
5695 ------------------------------------------------
5697 procedure Check_Access_Discriminant_Requires_Limited
5702 -- A discriminant_specification for an access discriminant
5703 -- shall appear only in the declaration for a task or protected
5704 -- type, or for a type with the reserved word 'limited' in
5705 -- its definition or in one of its ancestors. (RM 3.7(10))
5707 if Nkind (Discriminant_Type (D)) = N_Access_Definition
5708 and then not Is_Concurrent_Type (Current_Scope)
5709 and then not Is_Concurrent_Record_Type (Current_Scope)
5710 and then not Is_Limited_Record (Current_Scope)
5711 and then Ekind (Current_Scope) /= E_Limited_Private_Type
5714 ("access discriminants allowed only for limited types", Loc);
5716 end Check_Access_Discriminant_Requires_Limited;
5718 -----------------------------------
5719 -- Check_Aliased_Component_Types --
5720 -----------------------------------
5722 procedure Check_Aliased_Component_Types (T : Entity_Id) is
5726 -- ??? Also need to check components of record extensions,
5727 -- but not components of protected types (which are always
5730 if not Is_Limited_Type (T) then
5731 if Ekind (T) = E_Record_Type then
5732 C := First_Component (T);
5733 while Present (C) loop
5735 and then Has_Discriminants (Etype (C))
5736 and then not Is_Constrained (Etype (C))
5737 and then not In_Instance
5740 ("aliased component must be constrained ('R'M 3.6(11))",
5747 elsif Ekind (T) = E_Array_Type then
5748 if Has_Aliased_Components (T)
5749 and then Has_Discriminants (Component_Type (T))
5750 and then not Is_Constrained (Component_Type (T))
5751 and then not In_Instance
5754 ("aliased component type must be constrained ('R'M 3.6(11))",
5759 end Check_Aliased_Component_Types;
5761 ----------------------
5762 -- Check_Completion --
5763 ----------------------
5765 procedure Check_Completion (Body_Id : Node_Id := Empty) is
5768 procedure Post_Error;
5769 -- Post error message for lack of completion for entity E
5771 procedure Post_Error is
5773 if not Comes_From_Source (E) then
5775 if (Ekind (E) = E_Task_Type
5776 or else Ekind (E) = E_Protected_Type)
5778 -- It may be an anonymous protected type created for a
5779 -- single variable. Post error on variable, if present.
5785 Var := First_Entity (Current_Scope);
5787 while Present (Var) loop
5788 exit when Etype (Var) = E
5789 and then Comes_From_Source (Var);
5794 if Present (Var) then
5801 -- If a generated entity has no completion, then either previous
5802 -- semantic errors have disabled the expansion phase, or else
5803 -- we had missing subunits, or else we are compiling without expan-
5804 -- sion, or else something is very wrong.
5806 if not Comes_From_Source (E) then
5808 (Errors_Detected > 0
5809 or else Subunits_Missing
5810 or else not Expander_Active);
5813 -- Here for source entity
5816 -- Here if no body to post the error message, so we post the error
5817 -- on the declaration that has no completion. This is not really
5818 -- the right place to post it, think about this later ???
5820 if No (Body_Id) then
5823 ("missing full declaration for }", Parent (E), E);
5826 ("missing body for &", Parent (E), E);
5829 -- Package body has no completion for a declaration that appears
5830 -- in the corresponding spec. Post error on the body, with a
5831 -- reference to the non-completed declaration.
5834 Error_Msg_Sloc := Sloc (E);
5838 ("missing full declaration for }!", Body_Id, E);
5840 elsif Is_Overloadable (E)
5841 and then Current_Entity_In_Scope (E) /= E
5843 -- It may be that the completion is mistyped and appears
5844 -- as a distinct overloading of the entity.
5847 Candidate : Entity_Id := Current_Entity_In_Scope (E);
5848 Decl : Node_Id := Unit_Declaration_Node (Candidate);
5851 if Is_Overloadable (Candidate)
5852 and then Ekind (Candidate) = Ekind (E)
5853 and then Nkind (Decl) = N_Subprogram_Body
5854 and then Acts_As_Spec (Decl)
5856 Check_Type_Conformant (Candidate, E);
5859 Error_Msg_NE ("missing body for & declared#!",
5864 Error_Msg_NE ("missing body for & declared#!",
5871 -- Start processing for Check_Completion
5874 E := First_Entity (Current_Scope);
5875 while Present (E) loop
5876 if Is_Intrinsic_Subprogram (E) then
5879 -- The following situation requires special handling: a child
5880 -- unit that appears in the context clause of the body of its
5883 -- procedure Parent.Child (...);
5885 -- with Parent.Child;
5886 -- package body Parent is
5888 -- Here Parent.Child appears as a local entity, but should not
5889 -- be flagged as requiring completion, because it is a
5890 -- compilation unit.
5892 elsif Ekind (E) = E_Function
5893 or else Ekind (E) = E_Procedure
5894 or else Ekind (E) = E_Generic_Function
5895 or else Ekind (E) = E_Generic_Procedure
5897 if not Has_Completion (E)
5898 and then not Is_Abstract (E)
5899 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5901 and then Chars (E) /= Name_uSize
5906 elsif Is_Entry (E) then
5907 if not Has_Completion (E) and then
5908 (Ekind (Scope (E)) = E_Protected_Object
5909 or else Ekind (Scope (E)) = E_Protected_Type)
5914 elsif Is_Package (E) then
5915 if Unit_Requires_Body (E) then
5916 if not Has_Completion (E)
5917 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5923 elsif not Is_Child_Unit (E) then
5924 May_Need_Implicit_Body (E);
5927 elsif Ekind (E) = E_Incomplete_Type
5928 and then No (Underlying_Type (E))
5932 elsif (Ekind (E) = E_Task_Type or else
5933 Ekind (E) = E_Protected_Type)
5934 and then not Has_Completion (E)
5938 elsif Ekind (E) = E_Constant
5939 and then Ekind (Etype (E)) = E_Task_Type
5940 and then not Has_Completion (Etype (E))
5944 elsif Ekind (E) = E_Protected_Object
5945 and then not Has_Completion (Etype (E))
5949 elsif Ekind (E) = E_Record_Type then
5950 if Is_Tagged_Type (E) then
5951 Check_Abstract_Overriding (E);
5954 Check_Aliased_Component_Types (E);
5956 elsif Ekind (E) = E_Array_Type then
5957 Check_Aliased_Component_Types (E);
5963 end Check_Completion;
5965 ----------------------------
5966 -- Check_Delta_Expression --
5967 ----------------------------
5969 procedure Check_Delta_Expression (E : Node_Id) is
5971 if not (Is_Real_Type (Etype (E))) then
5972 Wrong_Type (E, Any_Real);
5974 elsif not Is_OK_Static_Expression (E) then
5975 Error_Msg_N ("non-static expression used for delta value", E);
5977 elsif not UR_Is_Positive (Expr_Value_R (E)) then
5978 Error_Msg_N ("delta expression must be positive", E);
5984 -- If any of above errors occurred, then replace the incorrect
5985 -- expression by the real 0.1, which should prevent further errors.
5988 Make_Real_Literal (Sloc (E), Ureal_Tenth));
5989 Analyze_And_Resolve (E, Standard_Float);
5991 end Check_Delta_Expression;
5993 -----------------------------
5994 -- Check_Digits_Expression --
5995 -----------------------------
5997 procedure Check_Digits_Expression (E : Node_Id) is
5999 if not (Is_Integer_Type (Etype (E))) then
6000 Wrong_Type (E, Any_Integer);
6002 elsif not Is_OK_Static_Expression (E) then
6003 Error_Msg_N ("non-static expression used for digits value", E);
6005 elsif Expr_Value (E) <= 0 then
6006 Error_Msg_N ("digits value must be greater than zero", E);
6012 -- If any of above errors occurred, then replace the incorrect
6013 -- expression by the integer 1, which should prevent further errors.
6015 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
6016 Analyze_And_Resolve (E, Standard_Integer);
6018 end Check_Digits_Expression;
6020 ----------------------
6021 -- Check_Incomplete --
6022 ----------------------
6024 procedure Check_Incomplete (T : Entity_Id) is
6026 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
6027 Error_Msg_N ("invalid use of type before its full declaration", T);
6029 end Check_Incomplete;
6031 --------------------------
6032 -- Check_Initialization --
6033 --------------------------
6035 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
6037 if (Is_Limited_Type (T)
6038 or else Is_Limited_Composite (T))
6039 and then not In_Instance
6042 ("cannot initialize entities of limited type", Exp);
6044 end Check_Initialization;
6046 ------------------------------------
6047 -- Check_Or_Process_Discriminants --
6048 ------------------------------------
6050 -- If an incomplete or private type declaration was already given for
6051 -- the type, the discriminants may have already been processed if they
6052 -- were present on the incomplete declaration. In this case a full
6053 -- conformance check is performed otherwise just process them.
6055 procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id) is
6057 if Has_Discriminants (T) then
6059 -- Make the discriminants visible to component declarations.
6062 D : Entity_Id := First_Discriminant (T);
6066 while Present (D) loop
6067 Prev := Current_Entity (D);
6068 Set_Current_Entity (D);
6069 Set_Is_Immediately_Visible (D);
6070 Set_Homonym (D, Prev);
6072 -- This restriction gets applied to the full type here; it
6073 -- has already been applied earlier to the partial view
6075 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6077 Next_Discriminant (D);
6081 elsif Present (Discriminant_Specifications (N)) then
6082 Process_Discriminants (N);
6084 end Check_Or_Process_Discriminants;
6086 ----------------------
6087 -- Check_Real_Bound --
6088 ----------------------
6090 procedure Check_Real_Bound (Bound : Node_Id) is
6092 if not Is_Real_Type (Etype (Bound)) then
6094 ("bound in real type definition must be of real type", Bound);
6096 elsif not Is_OK_Static_Expression (Bound) then
6098 ("non-static expression used for real type bound", Bound);
6105 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6107 Resolve (Bound, Standard_Float);
6108 end Check_Real_Bound;
6110 ------------------------------
6111 -- Complete_Private_Subtype --
6112 ------------------------------
6114 procedure Complete_Private_Subtype
6117 Full_Base : Entity_Id;
6118 Related_Nod : Node_Id)
6120 Save_Next_Entity : Entity_Id;
6121 Save_Homonym : Entity_Id;
6124 -- Set semantic attributes for (implicit) private subtype completion.
6125 -- If the full type has no discriminants, then it is a copy of the full
6126 -- view of the base. Otherwise, it is a subtype of the base with a
6127 -- possible discriminant constraint. Save and restore the original
6128 -- Next_Entity field of full to ensure that the calls to Copy_Node
6129 -- do not corrupt the entity chain.
6131 -- Note that the type of the full view is the same entity as the
6132 -- type of the partial view. In this fashion, the subtype has
6133 -- access to the correct view of the parent.
6135 Save_Next_Entity := Next_Entity (Full);
6136 Save_Homonym := Homonym (Priv);
6138 case Ekind (Full_Base) is
6140 when E_Record_Type |
6146 Copy_Node (Priv, Full);
6148 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6149 Set_First_Entity (Full, First_Entity (Full_Base));
6150 Set_Last_Entity (Full, Last_Entity (Full_Base));
6153 Copy_Node (Full_Base, Full);
6154 Set_Chars (Full, Chars (Priv));
6155 Conditional_Delay (Full, Priv);
6156 Set_Sloc (Full, Sloc (Priv));
6160 Set_Next_Entity (Full, Save_Next_Entity);
6161 Set_Homonym (Full, Save_Homonym);
6162 Set_Associated_Node_For_Itype (Full, Related_Nod);
6164 -- Set common attributes for all subtypes.
6166 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6168 -- The Etype of the full view is inconsistent. Gigi needs to see the
6169 -- structural full view, which is what the current scheme gives:
6170 -- the Etype of the full view is the etype of the full base. However,
6171 -- if the full base is a derived type, the full view then looks like
6172 -- a subtype of the parent, not a subtype of the full base. If instead
6175 -- Set_Etype (Full, Full_Base);
6177 -- then we get inconsistencies in the front-end (confusion between
6178 -- views). Several outstanding bugs are related to this.
6180 Set_Is_First_Subtype (Full, False);
6181 Set_Scope (Full, Scope (Priv));
6182 Set_Size_Info (Full, Full_Base);
6183 Set_RM_Size (Full, RM_Size (Full_Base));
6184 Set_Is_Itype (Full);
6186 -- A subtype of a private-type-without-discriminants, whose full-view
6187 -- has discriminants with default expressions, is not constrained!
6189 if not Has_Discriminants (Priv) then
6190 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6193 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6194 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6196 -- Freeze the private subtype entity if its parent is delayed,
6197 -- and not already frozen. We skip this processing if the type
6198 -- is an anonymous subtype of a record component, or is the
6199 -- corresponding record of a protected type, since ???
6201 if not Is_Type (Scope (Full)) then
6202 Set_Has_Delayed_Freeze (Full,
6203 Has_Delayed_Freeze (Full_Base)
6204 and then (not Is_Frozen (Full_Base)));
6207 Set_Freeze_Node (Full, Empty);
6208 Set_Is_Frozen (Full, False);
6209 Set_Full_View (Priv, Full);
6211 if Has_Discriminants (Full) then
6212 Set_Girder_Constraint_From_Discriminant_Constraint (Full);
6213 Set_Girder_Constraint (Priv, Girder_Constraint (Full));
6214 if Has_Unknown_Discriminants (Full) then
6215 Set_Discriminant_Constraint (Full, No_Elist);
6219 if Ekind (Full_Base) = E_Record_Type
6220 and then Has_Discriminants (Full_Base)
6221 and then Has_Discriminants (Priv) -- might not, if errors
6222 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
6224 Create_Constrained_Components
6225 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
6227 -- If the full base is itself derived from private, build a congruent
6228 -- subtype of its underlying type, for use by the back end.
6230 elsif Ekind (Full_Base) in Private_Kind
6231 and then Is_Derived_Type (Full_Base)
6232 and then Has_Discriminants (Full_Base)
6234 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
6236 Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
6238 elsif Is_Record_Type (Full_Base) then
6240 -- Show Full is simply a renaming of Full_Base.
6242 Set_Cloned_Subtype (Full, Full_Base);
6245 -- It is usafe to share to bounds of a scalar type, because the
6246 -- Itype is elaborated on demand, and if a bound is non-static
6247 -- then different orders of elaboration in different units will
6248 -- lead to different external symbols.
6250 if Is_Scalar_Type (Full_Base) then
6251 Set_Scalar_Range (Full,
6252 Make_Range (Sloc (Related_Nod),
6253 Low_Bound => Duplicate_Subexpr (Type_Low_Bound (Full_Base)),
6254 High_Bound => Duplicate_Subexpr (Type_High_Bound (Full_Base))));
6257 -- ??? It seems that a lot of fields are missing that should be
6258 -- copied from Full_Base to Full. Here are some that are introduced
6259 -- in a non-disruptive way but a cleanup is necessary.
6261 if Is_Tagged_Type (Full_Base) then
6262 Set_Is_Tagged_Type (Full);
6263 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
6265 elsif Is_Concurrent_Type (Full_Base) then
6267 if Has_Discriminants (Full)
6268 and then Present (Corresponding_Record_Type (Full_Base))
6270 Set_Corresponding_Record_Type (Full,
6271 Constrain_Corresponding_Record
6272 (Full, Corresponding_Record_Type (Full_Base),
6273 Related_Nod, Full_Base));
6276 Set_Corresponding_Record_Type (Full,
6277 Corresponding_Record_Type (Full_Base));
6281 end Complete_Private_Subtype;
6283 ----------------------------
6284 -- Constant_Redeclaration --
6285 ----------------------------
6287 procedure Constant_Redeclaration
6292 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
6293 Obj_Def : constant Node_Id := Object_Definition (N);
6297 if Nkind (Parent (Prev)) = N_Object_Declaration then
6298 if Nkind (Object_Definition
6299 (Parent (Prev))) = N_Subtype_Indication
6301 -- Find type of new declaration. The constraints of the two
6302 -- views must match statically, but there is no point in
6303 -- creating an itype for the full view.
6305 if Nkind (Obj_Def) = N_Subtype_Indication then
6306 Find_Type (Subtype_Mark (Obj_Def));
6307 New_T := Entity (Subtype_Mark (Obj_Def));
6310 Find_Type (Obj_Def);
6311 New_T := Entity (Obj_Def);
6317 -- The full view may impose a constraint, even if the partial
6318 -- view does not, so construct the subtype.
6320 New_T := Find_Type_Of_Object (Obj_Def, N);
6325 -- Current declaration is illegal, diagnosed below in Enter_Name.
6331 -- If previous full declaration exists, or if a homograph is present,
6332 -- let Enter_Name handle it, either with an error, or with the removal
6333 -- of an overridden implicit subprogram.
6335 if Ekind (Prev) /= E_Constant
6336 or else Present (Expression (Parent (Prev)))
6340 -- Verify that types of both declarations match.
6342 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
6343 Error_Msg_Sloc := Sloc (Prev);
6344 Error_Msg_N ("type does not match declaration#", N);
6345 Set_Full_View (Prev, Id);
6346 Set_Etype (Id, Any_Type);
6348 -- If so, process the full constant declaration
6351 Set_Full_View (Prev, Id);
6352 Set_Is_Public (Id, Is_Public (Prev));
6353 Set_Is_Internal (Id);
6354 Append_Entity (Id, Current_Scope);
6356 -- Check ALIASED present if present before (RM 7.4(7))
6358 if Is_Aliased (Prev)
6359 and then not Aliased_Present (N)
6361 Error_Msg_Sloc := Sloc (Prev);
6362 Error_Msg_N ("ALIASED required (see declaration#)", N);
6365 -- Check that placement is in private part
6367 if Ekind (Current_Scope) = E_Package
6368 and then not In_Private_Part (Current_Scope)
6370 Error_Msg_Sloc := Sloc (Prev);
6371 Error_Msg_N ("full constant for declaration#"
6372 & " must be in private part", N);
6375 end Constant_Redeclaration;
6377 ----------------------
6378 -- Constrain_Access --
6379 ----------------------
6381 procedure Constrain_Access
6382 (Def_Id : in out Entity_Id;
6384 Related_Nod : Node_Id)
6386 T : constant Entity_Id := Entity (Subtype_Mark (S));
6387 Desig_Type : constant Entity_Id := Designated_Type (T);
6388 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
6389 Constraint_OK : Boolean := True;
6392 if Is_Array_Type (Desig_Type) then
6393 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
6395 elsif (Is_Record_Type (Desig_Type)
6396 or else Is_Incomplete_Or_Private_Type (Desig_Type))
6397 and then not Is_Constrained (Desig_Type)
6399 -- ??? The following code is a temporary kludge to ignore
6400 -- discriminant constraint on access type if
6401 -- it is constraining the current record. Avoid creating the
6402 -- implicit subtype of the record we are currently compiling
6403 -- since right now, we cannot handle these.
6404 -- For now, just return the access type itself.
6406 if Desig_Type = Current_Scope
6407 and then No (Def_Id)
6409 Set_Ekind (Desig_Subtype, E_Record_Subtype);
6410 Def_Id := Entity (Subtype_Mark (S));
6412 -- This call added to ensure that the constraint is
6413 -- analyzed (needed for a B test). Note that we
6414 -- still return early from this procedure to avoid
6415 -- recursive processing. ???
6417 Constrain_Discriminated_Type
6418 (Desig_Subtype, S, Related_Nod, For_Access => True);
6423 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
6424 For_Access => True);
6426 elsif (Is_Task_Type (Desig_Type)
6427 or else Is_Protected_Type (Desig_Type))
6428 and then not Is_Constrained (Desig_Type)
6430 Constrain_Concurrent
6431 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
6434 Error_Msg_N ("invalid constraint on access type", S);
6435 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
6436 Constraint_OK := False;
6440 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
6442 Set_Ekind (Def_Id, E_Access_Subtype);
6445 if Constraint_OK then
6446 Set_Etype (Def_Id, Base_Type (T));
6448 if Is_Private_Type (Desig_Type) then
6449 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
6452 Set_Etype (Def_Id, Any_Type);
6455 Set_Size_Info (Def_Id, T);
6456 Set_Is_Constrained (Def_Id, Constraint_OK);
6457 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
6458 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6459 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
6461 -- Itypes created for constrained record components do not receive
6462 -- a freeze node, they are elaborated when first seen.
6464 if not Is_Record_Type (Current_Scope) then
6465 Conditional_Delay (Def_Id, T);
6467 end Constrain_Access;
6469 ---------------------
6470 -- Constrain_Array --
6471 ---------------------
6473 procedure Constrain_Array
6474 (Def_Id : in out Entity_Id;
6476 Related_Nod : Node_Id;
6477 Related_Id : Entity_Id;
6480 C : constant Node_Id := Constraint (SI);
6481 Number_Of_Constraints : Nat := 0;
6484 Constraint_OK : Boolean := True;
6487 T := Entity (Subtype_Mark (SI));
6489 if Ekind (T) in Access_Kind then
6490 T := Designated_Type (T);
6493 -- If an index constraint follows a subtype mark in a subtype indication
6494 -- then the type or subtype denoted by the subtype mark must not already
6495 -- impose an index constraint. The subtype mark must denote either an
6496 -- unconstrained array type or an access type whose designated type
6497 -- is such an array type... (RM 3.6.1)
6499 if Is_Constrained (T) then
6501 ("array type is already constrained", Subtype_Mark (SI));
6502 Constraint_OK := False;
6505 S := First (Constraints (C));
6507 while Present (S) loop
6508 Number_Of_Constraints := Number_Of_Constraints + 1;
6512 -- In either case, the index constraint must provide a discrete
6513 -- range for each index of the array type and the type of each
6514 -- discrete range must be the same as that of the corresponding
6515 -- index. (RM 3.6.1)
6517 if Number_Of_Constraints /= Number_Dimensions (T) then
6518 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
6519 Constraint_OK := False;
6522 S := First (Constraints (C));
6523 Index := First_Index (T);
6526 -- Apply constraints to each index type
6528 for J in 1 .. Number_Of_Constraints loop
6529 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
6539 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
6541 Set_Ekind (Def_Id, E_Array_Subtype);
6544 Set_Size_Info (Def_Id, (T));
6545 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6546 Set_Etype (Def_Id, Base_Type (T));
6548 if Constraint_OK then
6549 Set_First_Index (Def_Id, First (Constraints (C)));
6552 Set_Component_Type (Def_Id, Component_Type (T));
6553 Set_Is_Constrained (Def_Id, True);
6554 Set_Is_Aliased (Def_Id, Is_Aliased (T));
6555 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6557 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
6558 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
6560 -- If the subtype is not that of a record component, build a freeze
6561 -- node if parent still needs one.
6563 -- If the subtype is not that of a record component, make sure
6564 -- that the Depends_On_Private status is set (explanation ???)
6565 -- and also that a conditional delay is set.
6567 if not Is_Type (Scope (Def_Id)) then
6568 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6569 Conditional_Delay (Def_Id, T);
6572 end Constrain_Array;
6574 ------------------------------
6575 -- Constrain_Component_Type --
6576 ------------------------------
6578 function Constrain_Component_Type
6579 (Compon_Type : Entity_Id;
6580 Constrained_Typ : Entity_Id;
6581 Related_Node : Node_Id;
6583 Constraints : Elist_Id)
6586 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
6588 function Build_Constrained_Array_Type
6589 (Old_Type : Entity_Id)
6591 -- If Old_Type is an array type, one of whose indices is
6592 -- constrained by a discriminant, build an Itype whose constraint
6593 -- replaces the discriminant with its value in the constraint.
6595 function Build_Constrained_Discriminated_Type
6596 (Old_Type : Entity_Id)
6598 -- Ditto for record components.
6600 function Build_Constrained_Access_Type
6601 (Old_Type : Entity_Id)
6603 -- Ditto for access types. Makes use of previous two functions, to
6604 -- constrain designated type.
6606 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
6607 -- T is an array or discriminated type, C is a list of constraints
6608 -- that apply to T. This routine builds the constrained subtype.
6610 function Is_Discriminant (Expr : Node_Id) return Boolean;
6611 -- Returns True if Expr is a discriminant.
6613 function Get_Value (Discrim : Entity_Id) return Node_Id;
6614 -- Find the value of discriminant Discrim in Constraint.
6616 -----------------------------------
6617 -- Build_Constrained_Access_Type --
6618 -----------------------------------
6620 function Build_Constrained_Access_Type
6621 (Old_Type : Entity_Id)
6624 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
6626 Desig_Subtype : Entity_Id;
6630 -- if the original access type was not embedded in the enclosing
6631 -- type definition, there is no need to produce a new access
6632 -- subtype. In fact every access type with an explicit constraint
6633 -- generates an itype whose scope is the enclosing record.
6635 if not Is_Type (Scope (Old_Type)) then
6638 elsif Is_Array_Type (Desig_Type) then
6639 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
6641 elsif Has_Discriminants (Desig_Type) then
6643 -- This may be an access type to an enclosing record type for
6644 -- which we are constructing the constrained components. Return
6645 -- the enclosing record subtype. This is not always correct,
6646 -- but avoids infinite recursion. ???
6648 Desig_Subtype := Any_Type;
6650 for J in reverse 0 .. Scope_Stack.Last loop
6651 Scop := Scope_Stack.Table (J).Entity;
6654 and then Base_Type (Scop) = Base_Type (Desig_Type)
6656 Desig_Subtype := Scop;
6659 exit when not Is_Type (Scop);
6662 if Desig_Subtype = Any_Type then
6664 Build_Constrained_Discriminated_Type (Desig_Type);
6671 if Desig_Subtype /= Desig_Type then
6672 -- The Related_Node better be here or else we won't be able
6673 -- to attach new itypes to a node in the tree.
6675 pragma Assert (Present (Related_Node));
6677 Itype := Create_Itype (E_Access_Subtype, Related_Node);
6679 Set_Etype (Itype, Base_Type (Old_Type));
6680 Set_Size_Info (Itype, (Old_Type));
6681 Set_Directly_Designated_Type (Itype, Desig_Subtype);
6682 Set_Depends_On_Private (Itype, Has_Private_Component
6684 Set_Is_Access_Constant (Itype, Is_Access_Constant
6687 -- The new itype needs freezing when it depends on a not frozen
6688 -- type and the enclosing subtype needs freezing.
6690 if Has_Delayed_Freeze (Constrained_Typ)
6691 and then not Is_Frozen (Constrained_Typ)
6693 Conditional_Delay (Itype, Base_Type (Old_Type));
6701 end Build_Constrained_Access_Type;
6703 ----------------------------------
6704 -- Build_Constrained_Array_Type --
6705 ----------------------------------
6707 function Build_Constrained_Array_Type
6708 (Old_Type : Entity_Id)
6713 Old_Index : Node_Id;
6714 Range_Node : Node_Id;
6715 Constr_List : List_Id;
6717 Need_To_Create_Itype : Boolean := False;
6720 Old_Index := First_Index (Old_Type);
6721 while Present (Old_Index) loop
6722 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6724 if Is_Discriminant (Lo_Expr)
6725 or else Is_Discriminant (Hi_Expr)
6727 Need_To_Create_Itype := True;
6730 Next_Index (Old_Index);
6733 if Need_To_Create_Itype then
6734 Constr_List := New_List;
6736 Old_Index := First_Index (Old_Type);
6737 while Present (Old_Index) loop
6738 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6740 if Is_Discriminant (Lo_Expr) then
6741 Lo_Expr := Get_Value (Lo_Expr);
6744 if Is_Discriminant (Hi_Expr) then
6745 Hi_Expr := Get_Value (Hi_Expr);
6750 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
6752 Append (Range_Node, To => Constr_List);
6754 Next_Index (Old_Index);
6757 return Build_Subtype (Old_Type, Constr_List);
6762 end Build_Constrained_Array_Type;
6764 ------------------------------------------
6765 -- Build_Constrained_Discriminated_Type --
6766 ------------------------------------------
6768 function Build_Constrained_Discriminated_Type
6769 (Old_Type : Entity_Id)
6773 Constr_List : List_Id;
6774 Old_Constraint : Elmt_Id;
6776 Need_To_Create_Itype : Boolean := False;
6779 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6780 while Present (Old_Constraint) loop
6781 Expr := Node (Old_Constraint);
6783 if Is_Discriminant (Expr) then
6784 Need_To_Create_Itype := True;
6787 Next_Elmt (Old_Constraint);
6790 if Need_To_Create_Itype then
6791 Constr_List := New_List;
6793 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6794 while Present (Old_Constraint) loop
6795 Expr := Node (Old_Constraint);
6797 if Is_Discriminant (Expr) then
6798 Expr := Get_Value (Expr);
6801 Append (New_Copy_Tree (Expr), To => Constr_List);
6803 Next_Elmt (Old_Constraint);
6806 return Build_Subtype (Old_Type, Constr_List);
6811 end Build_Constrained_Discriminated_Type;
6817 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
6819 Subtyp_Decl : Node_Id;
6821 Btyp : Entity_Id := Base_Type (T);
6824 -- The Related_Node better be here or else we won't be able
6825 -- to attach new itypes to a node in the tree.
6827 pragma Assert (Present (Related_Node));
6829 -- If the view of the component's type is incomplete or private
6830 -- with unknown discriminants, then the constraint must be applied
6831 -- to the full type.
6833 if Has_Unknown_Discriminants (Btyp)
6834 and then Present (Underlying_Type (Btyp))
6836 Btyp := Underlying_Type (Btyp);
6840 Make_Subtype_Indication (Loc,
6841 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
6842 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
6844 Def_Id := Create_Itype (Ekind (T), Related_Node);
6847 Make_Subtype_Declaration (Loc,
6848 Defining_Identifier => Def_Id,
6849 Subtype_Indication => Indic);
6850 Set_Parent (Subtyp_Decl, Parent (Related_Node));
6852 -- Itypes must be analyzed with checks off (see itypes.ads).
6854 Analyze (Subtyp_Decl, Suppress => All_Checks);
6863 function Get_Value (Discrim : Entity_Id) return Node_Id is
6864 D : Entity_Id := First_Discriminant (Typ);
6865 E : Elmt_Id := First_Elmt (Constraints);
6868 while Present (D) loop
6870 -- If we are constraining the subtype of a derived tagged type,
6871 -- recover the discriminant of the parent, which appears in
6872 -- the constraint of an inherited component.
6874 if D = Entity (Discrim)
6875 or else Corresponding_Discriminant (D) = Entity (Discrim)
6880 Next_Discriminant (D);
6884 -- Something is wrong if we did not find the value
6886 raise Program_Error;
6889 ---------------------
6890 -- Is_Discriminant --
6891 ---------------------
6893 function Is_Discriminant (Expr : Node_Id) return Boolean is
6894 Discrim_Scope : Entity_Id;
6897 if Denotes_Discriminant (Expr) then
6898 Discrim_Scope := Scope (Entity (Expr));
6900 -- Either we have a reference to one of Typ's discriminants,
6902 pragma Assert (Discrim_Scope = Typ
6904 -- or to the discriminants of the parent type, in the case
6905 -- of a derivation of a tagged type with variants.
6907 or else Discrim_Scope = Etype (Typ)
6908 or else Full_View (Discrim_Scope) = Etype (Typ)
6910 -- or same as above for the case where the discriminants
6911 -- were declared in Typ's private view.
6913 or else (Is_Private_Type (Discrim_Scope)
6914 and then Chars (Discrim_Scope) = Chars (Typ))
6916 -- or else we are deriving from the full view and the
6917 -- discriminant is declared in the private entity.
6919 or else (Is_Private_Type (Typ)
6920 and then Chars (Discrim_Scope) = Chars (Typ))
6922 -- or we have a class-wide type, in which case make sure the
6923 -- discriminant found belongs to the root type.
6925 or else (Is_Class_Wide_Type (Typ)
6926 and then Etype (Typ) = Discrim_Scope));
6931 -- In all other cases we have something wrong.
6934 end Is_Discriminant;
6936 -- Start of processing for Constrain_Component_Type
6939 if Is_Array_Type (Compon_Type) then
6940 return Build_Constrained_Array_Type (Compon_Type);
6942 elsif Has_Discriminants (Compon_Type) then
6943 return Build_Constrained_Discriminated_Type (Compon_Type);
6945 elsif Is_Access_Type (Compon_Type) then
6946 return Build_Constrained_Access_Type (Compon_Type);
6950 end Constrain_Component_Type;
6952 --------------------------
6953 -- Constrain_Concurrent --
6954 --------------------------
6956 -- For concurrent types, the associated record value type carries the same
6957 -- discriminants, so when we constrain a concurrent type, we must constrain
6958 -- the value type as well.
6960 procedure Constrain_Concurrent
6961 (Def_Id : in out Entity_Id;
6963 Related_Nod : Node_Id;
6964 Related_Id : Entity_Id;
6967 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
6971 if Ekind (T_Ent) in Access_Kind then
6972 T_Ent := Designated_Type (T_Ent);
6975 T_Val := Corresponding_Record_Type (T_Ent);
6977 if Present (T_Val) then
6980 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6983 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
6985 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6986 Set_Corresponding_Record_Type (Def_Id,
6987 Constrain_Corresponding_Record
6988 (Def_Id, T_Val, Related_Nod, Related_Id));
6991 -- If there is no associated record, expansion is disabled and this
6992 -- is a generic context. Create a subtype in any case, so that
6993 -- semantic analysis can proceed.
6996 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6999 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7001 end Constrain_Concurrent;
7003 ------------------------------------
7004 -- Constrain_Corresponding_Record --
7005 ------------------------------------
7007 function Constrain_Corresponding_Record
7008 (Prot_Subt : Entity_Id;
7009 Corr_Rec : Entity_Id;
7010 Related_Nod : Node_Id;
7011 Related_Id : Entity_Id)
7014 T_Sub : constant Entity_Id
7015 := Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
7018 Set_Etype (T_Sub, Corr_Rec);
7019 Init_Size_Align (T_Sub);
7020 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
7021 Set_Is_Constrained (T_Sub, True);
7022 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
7023 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
7025 Conditional_Delay (T_Sub, Corr_Rec);
7027 if Has_Discriminants (Prot_Subt) then -- False only if errors.
7028 Set_Discriminant_Constraint (T_Sub,
7029 Discriminant_Constraint (Prot_Subt));
7030 Set_Girder_Constraint_From_Discriminant_Constraint (T_Sub);
7031 Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
7032 Discriminant_Constraint (T_Sub));
7035 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
7038 end Constrain_Corresponding_Record;
7040 -----------------------
7041 -- Constrain_Decimal --
7042 -----------------------
7044 procedure Constrain_Decimal
7047 Related_Nod : Node_Id)
7049 T : constant Entity_Id := Entity (Subtype_Mark (S));
7050 C : constant Node_Id := Constraint (S);
7051 Loc : constant Source_Ptr := Sloc (C);
7052 Range_Expr : Node_Id;
7053 Digits_Expr : Node_Id;
7058 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7060 if Nkind (C) = N_Range_Constraint then
7061 Range_Expr := Range_Expression (C);
7062 Digits_Val := Digits_Value (T);
7065 pragma Assert (Nkind (C) = N_Digits_Constraint);
7066 Digits_Expr := Digits_Expression (C);
7067 Analyze_And_Resolve (Digits_Expr, Any_Integer);
7069 Check_Digits_Expression (Digits_Expr);
7070 Digits_Val := Expr_Value (Digits_Expr);
7072 if Digits_Val > Digits_Value (T) then
7074 ("digits expression is incompatible with subtype", C);
7075 Digits_Val := Digits_Value (T);
7078 if Present (Range_Constraint (C)) then
7079 Range_Expr := Range_Expression (Range_Constraint (C));
7081 Range_Expr := Empty;
7085 Set_Etype (Def_Id, Base_Type (T));
7086 Set_Size_Info (Def_Id, (T));
7087 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7088 Set_Delta_Value (Def_Id, Delta_Value (T));
7089 Set_Scale_Value (Def_Id, Scale_Value (T));
7090 Set_Small_Value (Def_Id, Small_Value (T));
7091 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
7092 Set_Digits_Value (Def_Id, Digits_Val);
7094 -- Manufacture range from given digits value if no range present
7096 if No (Range_Expr) then
7097 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
7101 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
7103 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
7107 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T, Related_Nod);
7108 Set_Discrete_RM_Size (Def_Id);
7110 -- Unconditionally delay the freeze, since we cannot set size
7111 -- information in all cases correctly until the freeze point.
7113 Set_Has_Delayed_Freeze (Def_Id);
7114 end Constrain_Decimal;
7116 ----------------------------------
7117 -- Constrain_Discriminated_Type --
7118 ----------------------------------
7120 procedure Constrain_Discriminated_Type
7121 (Def_Id : Entity_Id;
7123 Related_Nod : Node_Id;
7124 For_Access : Boolean := False)
7128 Elist : Elist_Id := New_Elmt_List;
7130 procedure Fixup_Bad_Constraint;
7131 -- This is called after finding a bad constraint, and after having
7132 -- posted an appropriate error message. The mission is to leave the
7133 -- entity T in as reasonable state as possible!
7135 procedure Fixup_Bad_Constraint is
7137 -- Set a reasonable Ekind for the entity. For an incomplete type,
7138 -- we can't do much, but for other types, we can set the proper
7139 -- corresponding subtype kind.
7141 if Ekind (T) = E_Incomplete_Type then
7142 Set_Ekind (Def_Id, Ekind (T));
7144 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
7147 Set_Etype (Def_Id, Any_Type);
7148 Set_Error_Posted (Def_Id);
7149 end Fixup_Bad_Constraint;
7151 -- Start of processing for Constrain_Discriminated_Type
7154 C := Constraint (S);
7156 -- A discriminant constraint is only allowed in a subtype indication,
7157 -- after a subtype mark. This subtype mark must denote either a type
7158 -- with discriminants, or an access type whose designated type is a
7159 -- type with discriminants. A discriminant constraint specifies the
7160 -- values of these discriminants (RM 3.7.2(5)).
7162 T := Base_Type (Entity (Subtype_Mark (S)));
7164 if Ekind (T) in Access_Kind then
7165 T := Designated_Type (T);
7168 if not Has_Discriminants (T) then
7169 Error_Msg_N ("invalid constraint: type has no discriminant", C);
7170 Fixup_Bad_Constraint;
7173 elsif Is_Constrained (Entity (Subtype_Mark (S))) then
7174 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
7175 Fixup_Bad_Constraint;
7179 -- T may be an unconstrained subtype (e.g. a generic actual).
7180 -- Constraint applies to the base type.
7184 Elist := Build_Discriminant_Constraints (T, S);
7186 -- If the list returned was empty we had an error in building the
7187 -- discriminant constraint. We have also already signalled an error
7188 -- in the incomplete type case
7190 if Is_Empty_Elmt_List (Elist) then
7191 Fixup_Bad_Constraint;
7195 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
7196 end Constrain_Discriminated_Type;
7198 ---------------------------
7199 -- Constrain_Enumeration --
7200 ---------------------------
7202 procedure Constrain_Enumeration
7205 Related_Nod : Node_Id)
7207 T : constant Entity_Id := Entity (Subtype_Mark (S));
7208 C : constant Node_Id := Constraint (S);
7211 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7213 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
7215 Set_Etype (Def_Id, Base_Type (T));
7216 Set_Size_Info (Def_Id, (T));
7217 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7218 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7220 Set_Scalar_Range_For_Subtype
7221 (Def_Id, Range_Expression (C), T, Related_Nod);
7223 Set_Discrete_RM_Size (Def_Id);
7225 end Constrain_Enumeration;
7227 ----------------------
7228 -- Constrain_Float --
7229 ----------------------
7231 procedure Constrain_Float
7234 Related_Nod : Node_Id)
7236 T : constant Entity_Id := Entity (Subtype_Mark (S));
7242 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
7244 Set_Etype (Def_Id, Base_Type (T));
7245 Set_Size_Info (Def_Id, (T));
7246 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7248 -- Process the constraint
7250 C := Constraint (S);
7252 -- Digits constraint present
7254 if Nkind (C) = N_Digits_Constraint then
7255 D := Digits_Expression (C);
7256 Analyze_And_Resolve (D, Any_Integer);
7257 Check_Digits_Expression (D);
7258 Set_Digits_Value (Def_Id, Expr_Value (D));
7260 -- Check that digits value is in range. Obviously we can do this
7261 -- at compile time, but it is strictly a runtime check, and of
7262 -- course there is an ACVC test that checks this!
7264 if Digits_Value (Def_Id) > Digits_Value (T) then
7265 Error_Msg_Uint_1 := Digits_Value (T);
7266 Error_Msg_N ("?digits value is too large, maximum is ^", D);
7267 Rais := Make_Raise_Constraint_Error (Sloc (D));
7268 Insert_Action (Declaration_Node (Def_Id), Rais);
7271 C := Range_Constraint (C);
7273 -- No digits constraint present
7276 Set_Digits_Value (Def_Id, Digits_Value (T));
7279 -- Range constraint present
7281 if Nkind (C) = N_Range_Constraint then
7282 Set_Scalar_Range_For_Subtype
7283 (Def_Id, Range_Expression (C), T, Related_Nod);
7285 -- No range constraint present
7288 pragma Assert (No (C));
7289 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7292 Set_Is_Constrained (Def_Id);
7293 end Constrain_Float;
7295 ---------------------
7296 -- Constrain_Index --
7297 ---------------------
7299 procedure Constrain_Index
7302 Related_Nod : Node_Id;
7303 Related_Id : Entity_Id;
7309 Checks_Off : Boolean := False;
7310 T : constant Entity_Id := Etype (Index);
7313 if Nkind (S) = N_Range
7314 or else Nkind (S) = N_Attribute_Reference
7316 -- A Range attribute will transformed into N_Range by Resolve.
7322 -- ??? Why on earth do we turn checks of in this very specific case ?
7324 -- From the revision history: (Constrain_Index): Call
7325 -- Process_Range_Expr_In_Decl with range checking off for range
7326 -- bounds that are attributes. This avoids some horrible
7327 -- constraint error checks.
7329 if Nkind (R) = N_Range
7330 and then Nkind (Low_Bound (R)) = N_Attribute_Reference
7331 and then Nkind (High_Bound (R)) = N_Attribute_Reference
7336 Process_Range_Expr_In_Decl
7337 (R, T, Related_Nod, Empty_List, Checks_Off);
7339 if not Error_Posted (S)
7341 (Nkind (S) /= N_Range
7342 or else Base_Type (T) /= Base_Type (Etype (Low_Bound (S)))
7343 or else Base_Type (T) /= Base_Type (Etype (High_Bound (S))))
7345 if Base_Type (T) /= Any_Type
7346 and then Etype (Low_Bound (S)) /= Any_Type
7347 and then Etype (High_Bound (S)) /= Any_Type
7349 Error_Msg_N ("range expected", S);
7353 elsif Nkind (S) = N_Subtype_Indication then
7354 -- the parser has verified that this is a discrete indication.
7356 Resolve_Discrete_Subtype_Indication (S, T);
7357 R := Range_Expression (Constraint (S));
7359 elsif Nkind (S) = N_Discriminant_Association then
7361 -- syntactically valid in subtype indication.
7363 Error_Msg_N ("invalid index constraint", S);
7364 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7367 -- Subtype_Mark case, no anonymous subtypes to construct
7372 if Is_Entity_Name (S) then
7374 if not Is_Type (Entity (S)) then
7375 Error_Msg_N ("expect subtype mark for index constraint", S);
7377 elsif Base_Type (Entity (S)) /= Base_Type (T) then
7378 Wrong_Type (S, Base_Type (T));
7384 Error_Msg_N ("invalid index constraint", S);
7385 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7391 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
7393 Set_Etype (Def_Id, Base_Type (T));
7395 if Is_Modular_Integer_Type (T) then
7396 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7398 elsif Is_Integer_Type (T) then
7399 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7402 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7403 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7406 Set_Size_Info (Def_Id, (T));
7407 Set_RM_Size (Def_Id, RM_Size (T));
7408 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7410 -- ??? ??? is R always initialized, not at all obvious why?
7412 Set_Scalar_Range (Def_Id, R);
7414 Set_Etype (S, Def_Id);
7415 Set_Discrete_RM_Size (Def_Id);
7416 end Constrain_Index;
7418 -----------------------
7419 -- Constrain_Integer --
7420 -----------------------
7422 procedure Constrain_Integer
7425 Related_Nod : Node_Id)
7427 T : constant Entity_Id := Entity (Subtype_Mark (S));
7428 C : constant Node_Id := Constraint (S);
7431 Set_Scalar_Range_For_Subtype
7432 (Def_Id, Range_Expression (C), T, Related_Nod);
7434 if Is_Modular_Integer_Type (T) then
7435 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7437 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7440 Set_Etype (Def_Id, Base_Type (T));
7441 Set_Size_Info (Def_Id, (T));
7442 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7443 Set_Discrete_RM_Size (Def_Id);
7445 end Constrain_Integer;
7447 ------------------------------
7448 -- Constrain_Ordinary_Fixed --
7449 ------------------------------
7451 procedure Constrain_Ordinary_Fixed
7454 Related_Nod : Node_Id)
7456 T : constant Entity_Id := Entity (Subtype_Mark (S));
7462 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
7463 Set_Etype (Def_Id, Base_Type (T));
7464 Set_Size_Info (Def_Id, (T));
7465 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7466 Set_Small_Value (Def_Id, Small_Value (T));
7468 -- Process the constraint
7470 C := Constraint (S);
7472 -- Delta constraint present
7474 if Nkind (C) = N_Delta_Constraint then
7475 D := Delta_Expression (C);
7476 Analyze_And_Resolve (D, Any_Real);
7477 Check_Delta_Expression (D);
7478 Set_Delta_Value (Def_Id, Expr_Value_R (D));
7480 -- Check that delta value is in range. Obviously we can do this
7481 -- at compile time, but it is strictly a runtime check, and of
7482 -- course there is an ACVC test that checks this!
7484 if Delta_Value (Def_Id) < Delta_Value (T) then
7485 Error_Msg_N ("?delta value is too small", D);
7486 Rais := Make_Raise_Constraint_Error (Sloc (D));
7487 Insert_Action (Declaration_Node (Def_Id), Rais);
7490 C := Range_Constraint (C);
7492 -- No delta constraint present
7495 Set_Delta_Value (Def_Id, Delta_Value (T));
7498 -- Range constraint present
7500 if Nkind (C) = N_Range_Constraint then
7501 Set_Scalar_Range_For_Subtype
7502 (Def_Id, Range_Expression (C), T, Related_Nod);
7504 -- No range constraint present
7507 pragma Assert (No (C));
7508 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7512 Set_Discrete_RM_Size (Def_Id);
7514 -- Unconditionally delay the freeze, since we cannot set size
7515 -- information in all cases correctly until the freeze point.
7517 Set_Has_Delayed_Freeze (Def_Id);
7518 end Constrain_Ordinary_Fixed;
7520 ---------------------------
7521 -- Convert_Scalar_Bounds --
7522 ---------------------------
7524 procedure Convert_Scalar_Bounds
7526 Parent_Type : Entity_Id;
7527 Derived_Type : Entity_Id;
7530 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
7537 Lo := Build_Scalar_Bound
7538 (Type_Low_Bound (Derived_Type),
7539 Parent_Type, Implicit_Base, Loc);
7541 Hi := Build_Scalar_Bound
7542 (Type_High_Bound (Derived_Type),
7543 Parent_Type, Implicit_Base, Loc);
7550 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
7552 Set_Parent (Rng, N);
7553 Set_Scalar_Range (Derived_Type, Rng);
7555 -- Analyze the bounds
7557 Analyze_And_Resolve (Lo, Implicit_Base);
7558 Analyze_And_Resolve (Hi, Implicit_Base);
7560 -- Analyze the range itself, except that we do not analyze it if
7561 -- the bounds are real literals, and we have a fixed-point type.
7562 -- The reason for this is that we delay setting the bounds in this
7563 -- case till we know the final Small and Size values (see circuit
7564 -- in Freeze.Freeze_Fixed_Point_Type for further details).
7566 if Is_Fixed_Point_Type (Parent_Type)
7567 and then Nkind (Lo) = N_Real_Literal
7568 and then Nkind (Hi) = N_Real_Literal
7572 -- Here we do the analysis of the range.
7574 -- Note: we do this manually, since if we do a normal Analyze and
7575 -- Resolve call, there are problems with the conversions used for
7576 -- the derived type range.
7579 Set_Etype (Rng, Implicit_Base);
7580 Set_Analyzed (Rng, True);
7582 end Convert_Scalar_Bounds;
7588 procedure Copy_And_Swap (Privat, Full : Entity_Id) is
7590 -- Initialize new full declaration entity by copying the pertinent
7591 -- fields of the corresponding private declaration entity.
7593 Copy_Private_To_Full (Privat, Full);
7595 -- Swap the two entities. Now Privat is the full type entity and
7596 -- Full is the private one. They will be swapped back at the end
7597 -- of the private part. This swapping ensures that the entity that
7598 -- is visible in the private part is the full declaration.
7600 Exchange_Entities (Privat, Full);
7601 Append_Entity (Full, Scope (Full));
7604 -------------------------------------
7605 -- Copy_Array_Base_Type_Attributes --
7606 -------------------------------------
7608 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
7610 Set_Component_Alignment (T1, Component_Alignment (T2));
7611 Set_Component_Type (T1, Component_Type (T2));
7612 Set_Component_Size (T1, Component_Size (T2));
7613 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
7614 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
7615 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
7616 Set_Has_Task (T1, Has_Task (T2));
7617 Set_Is_Packed (T1, Is_Packed (T2));
7618 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
7619 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
7620 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
7621 end Copy_Array_Base_Type_Attributes;
7623 -----------------------------------
7624 -- Copy_Array_Subtype_Attributes --
7625 -----------------------------------
7627 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
7629 Set_Size_Info (T1, T2);
7631 Set_First_Index (T1, First_Index (T2));
7632 Set_Is_Aliased (T1, Is_Aliased (T2));
7633 Set_Is_Atomic (T1, Is_Atomic (T2));
7634 Set_Is_Volatile (T1, Is_Volatile (T2));
7635 Set_Is_Constrained (T1, Is_Constrained (T2));
7636 Set_Depends_On_Private (T1, Has_Private_Component (T2));
7637 Set_First_Rep_Item (T1, First_Rep_Item (T2));
7638 Set_Convention (T1, Convention (T2));
7639 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
7640 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
7641 end Copy_Array_Subtype_Attributes;
7643 --------------------------
7644 -- Copy_Private_To_Full --
7645 --------------------------
7647 procedure Copy_Private_To_Full (Priv, Full : Entity_Id) is
7649 -- We temporarily set Ekind to a value appropriate for a type to
7650 -- avoid assert failures in Einfo from checking for setting type
7651 -- attributes on something that is not a type. Ekind (Priv) is an
7652 -- appropriate choice, since it allowed the attributes to be set
7653 -- in the first place. This Ekind value will be modified later.
7655 Set_Ekind (Full, Ekind (Priv));
7657 -- Also set Etype temporarily to Any_Type, again, in the absence
7658 -- of errors, it will be properly reset, and if there are errors,
7659 -- then we want a value of Any_Type to remain.
7661 Set_Etype (Full, Any_Type);
7663 -- Now start copying attributes
7665 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
7667 if Has_Discriminants (Full) then
7668 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
7669 Set_Girder_Constraint (Full, Girder_Constraint (Priv));
7672 Set_Homonym (Full, Homonym (Priv));
7673 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
7674 Set_Is_Public (Full, Is_Public (Priv));
7675 Set_Is_Pure (Full, Is_Pure (Priv));
7676 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
7678 Conditional_Delay (Full, Priv);
7680 if Is_Tagged_Type (Full) then
7681 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
7683 if Priv = Base_Type (Priv) then
7684 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
7688 Set_Is_Volatile (Full, Is_Volatile (Priv));
7689 Set_Scope (Full, Scope (Priv));
7690 Set_Next_Entity (Full, Next_Entity (Priv));
7691 Set_First_Entity (Full, First_Entity (Priv));
7692 Set_Last_Entity (Full, Last_Entity (Priv));
7694 -- If access types have been recorded for later handling, keep them
7695 -- in the full view so that they get handled when the full view freeze
7696 -- node is expanded.
7698 if Present (Freeze_Node (Priv))
7699 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
7701 Ensure_Freeze_Node (Full);
7702 Set_Access_Types_To_Process (Freeze_Node (Full),
7703 Access_Types_To_Process (Freeze_Node (Priv)));
7705 end Copy_Private_To_Full;
7707 -----------------------------------
7708 -- Create_Constrained_Components --
7709 -----------------------------------
7711 procedure Create_Constrained_Components
7713 Decl_Node : Node_Id;
7715 Constraints : Elist_Id)
7717 Loc : constant Source_Ptr := Sloc (Subt);
7718 Assoc_List : List_Id := New_List;
7719 Comp_List : Elist_Id := New_Elmt_List;
7720 Discr_Val : Elmt_Id;
7724 Is_Static : Boolean := True;
7725 Parent_Type : constant Entity_Id := Etype (Typ);
7727 procedure Collect_Fixed_Components (Typ : Entity_Id);
7728 -- Collect components of parent type that do not appear in a variant
7731 procedure Create_All_Components;
7732 -- Iterate over Comp_List to create the components of the subtype.
7734 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
7735 -- Creates a new component from Old_Compon, coppying all the fields from
7736 -- it, including its Etype, inserts the new component in the Subt entity
7737 -- chain and returns the new component.
7739 function Is_Variant_Record (T : Entity_Id) return Boolean;
7740 -- If true, and discriminants are static, collect only components from
7741 -- variants selected by discriminant values.
7743 ------------------------------
7744 -- Collect_Fixed_Components --
7745 ------------------------------
7747 procedure Collect_Fixed_Components (Typ : Entity_Id) is
7749 -- Build association list for discriminants, and find components of
7750 -- the variant part selected by the values of the discriminants.
7752 Old_C := First_Discriminant (Typ);
7753 Discr_Val := First_Elmt (Constraints);
7755 while Present (Old_C) loop
7756 Append_To (Assoc_List,
7757 Make_Component_Association (Loc,
7758 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
7759 Expression => New_Copy (Node (Discr_Val))));
7761 Next_Elmt (Discr_Val);
7762 Next_Discriminant (Old_C);
7765 -- The tag, and the possible parent and controller components
7766 -- are unconditionally in the subtype.
7768 if Is_Tagged_Type (Typ)
7769 or else Has_Controlled_Component (Typ)
7771 Old_C := First_Component (Typ);
7773 while Present (Old_C) loop
7774 if Chars ((Old_C)) = Name_uTag
7775 or else Chars ((Old_C)) = Name_uParent
7776 or else Chars ((Old_C)) = Name_uController
7778 Append_Elmt (Old_C, Comp_List);
7781 Next_Component (Old_C);
7784 end Collect_Fixed_Components;
7786 ---------------------------
7787 -- Create_All_Components --
7788 ---------------------------
7790 procedure Create_All_Components is
7794 Comp := First_Elmt (Comp_List);
7796 while Present (Comp) loop
7797 Old_C := Node (Comp);
7798 New_C := Create_Component (Old_C);
7802 Constrain_Component_Type
7803 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7804 Set_Is_Public (New_C, Is_Public (Subt));
7808 end Create_All_Components;
7810 ----------------------
7811 -- Create_Component --
7812 ----------------------
7814 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
7815 New_Compon : Entity_Id := New_Copy (Old_Compon);
7818 -- Set the parent so we have a proper link for freezing etc. This
7819 -- is not a real parent pointer, since of course our parent does
7820 -- not own up to us and reference us, we are an illegitimate
7821 -- child of the original parent!
7823 Set_Parent (New_Compon, Parent (Old_Compon));
7825 -- We do not want this node marked as Comes_From_Source, since
7826 -- otherwise it would get first class status and a separate
7827 -- cross-reference line would be generated. Illegitimate
7828 -- children do not rate such recognition.
7830 Set_Comes_From_Source (New_Compon, False);
7832 -- But it is a real entity, and a birth certificate must be
7833 -- properly registered by entering it into the entity list.
7835 Enter_Name (New_Compon);
7837 end Create_Component;
7839 -----------------------
7840 -- Is_Variant_Record --
7841 -----------------------
7843 function Is_Variant_Record (T : Entity_Id) return Boolean is
7845 return Nkind (Parent (T)) = N_Full_Type_Declaration
7846 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
7847 and then Present (Component_List (Type_Definition (Parent (T))))
7849 Variant_Part (Component_List (Type_Definition (Parent (T)))));
7850 end Is_Variant_Record;
7852 -- Start of processing for Create_Constrained_Components
7855 pragma Assert (Subt /= Base_Type (Subt));
7856 pragma Assert (Typ = Base_Type (Typ));
7858 Set_First_Entity (Subt, Empty);
7859 Set_Last_Entity (Subt, Empty);
7861 -- Check whether constraint is fully static, in which case we can
7862 -- optimize the list of components.
7864 Discr_Val := First_Elmt (Constraints);
7866 while Present (Discr_Val) loop
7868 if not Is_OK_Static_Expression (Node (Discr_Val)) then
7873 Next_Elmt (Discr_Val);
7878 -- Inherit the discriminants of the parent type.
7880 Old_C := First_Discriminant (Typ);
7882 while Present (Old_C) loop
7883 New_C := Create_Component (Old_C);
7884 Set_Is_Public (New_C, Is_Public (Subt));
7885 Next_Discriminant (Old_C);
7889 and then Is_Variant_Record (Typ)
7891 Collect_Fixed_Components (Typ);
7895 Component_List (Type_Definition (Parent (Typ))),
7896 Governed_By => Assoc_List,
7898 Report_Errors => Errors);
7899 pragma Assert (not Errors);
7901 Create_All_Components;
7903 -- If the subtype declaration is created for a tagged type derivation
7904 -- with constraints, we retrieve the record definition of the parent
7905 -- type to select the components of the proper variant.
7908 and then Is_Tagged_Type (Typ)
7909 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
7911 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
7912 and then Is_Variant_Record (Parent_Type)
7914 Collect_Fixed_Components (Typ);
7918 Component_List (Type_Definition (Parent (Parent_Type))),
7919 Governed_By => Assoc_List,
7921 Report_Errors => Errors);
7922 pragma Assert (not Errors);
7924 -- If the tagged derivation has a type extension, collect all the
7925 -- new components therein.
7928 Record_Extension_Part (Type_Definition (Parent (Typ))))
7930 Old_C := First_Component (Typ);
7932 while Present (Old_C) loop
7933 if Original_Record_Component (Old_C) = Old_C
7934 and then Chars (Old_C) /= Name_uTag
7935 and then Chars (Old_C) /= Name_uParent
7936 and then Chars (Old_C) /= Name_uController
7938 Append_Elmt (Old_C, Comp_List);
7941 Next_Component (Old_C);
7945 Create_All_Components;
7948 -- If the discriminants are not static, or if this is a multi-level
7949 -- type extension, we have to include all the components of the
7952 Old_C := First_Component (Typ);
7954 while Present (Old_C) loop
7955 New_C := Create_Component (Old_C);
7959 Constrain_Component_Type
7960 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7961 Set_Is_Public (New_C, Is_Public (Subt));
7963 Next_Component (Old_C);
7968 end Create_Constrained_Components;
7970 ------------------------------------------
7971 -- Decimal_Fixed_Point_Type_Declaration --
7972 ------------------------------------------
7974 procedure Decimal_Fixed_Point_Type_Declaration
7978 Loc : constant Source_Ptr := Sloc (Def);
7979 Digs_Expr : constant Node_Id := Digits_Expression (Def);
7980 Delta_Expr : constant Node_Id := Delta_Expression (Def);
7981 Implicit_Base : Entity_Id;
7987 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
7990 Check_Restriction (No_Fixed_Point, Def);
7992 -- Create implicit base type
7995 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
7996 Set_Etype (Implicit_Base, Implicit_Base);
7998 -- Analyze and process delta expression
8000 Analyze_And_Resolve (Delta_Expr, Universal_Real);
8002 Check_Delta_Expression (Delta_Expr);
8003 Delta_Val := Expr_Value_R (Delta_Expr);
8005 -- Check delta is power of 10, and determine scale value from it
8008 Val : Ureal := Delta_Val;
8011 Scale_Val := Uint_0;
8013 if Val < Ureal_1 then
8014 while Val < Ureal_1 loop
8015 Val := Val * Ureal_10;
8016 Scale_Val := Scale_Val + 1;
8019 if Scale_Val > 18 then
8020 Error_Msg_N ("scale exceeds maximum value of 18", Def);
8021 Scale_Val := UI_From_Int (+18);
8025 while Val > Ureal_1 loop
8026 Val := Val / Ureal_10;
8027 Scale_Val := Scale_Val - 1;
8030 if Scale_Val < -18 then
8031 Error_Msg_N ("scale is less than minimum value of -18", Def);
8032 Scale_Val := UI_From_Int (-18);
8036 if Val /= Ureal_1 then
8037 Error_Msg_N ("delta expression must be a power of 10", Def);
8038 Delta_Val := Ureal_10 ** (-Scale_Val);
8042 -- Set delta, scale and small (small = delta for decimal type)
8044 Set_Delta_Value (Implicit_Base, Delta_Val);
8045 Set_Scale_Value (Implicit_Base, Scale_Val);
8046 Set_Small_Value (Implicit_Base, Delta_Val);
8048 -- Analyze and process digits expression
8050 Analyze_And_Resolve (Digs_Expr, Any_Integer);
8051 Check_Digits_Expression (Digs_Expr);
8052 Digs_Val := Expr_Value (Digs_Expr);
8054 if Digs_Val > 18 then
8055 Digs_Val := UI_From_Int (+18);
8056 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8059 Set_Digits_Value (Implicit_Base, Digs_Val);
8060 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8062 -- Set range of base type from digits value for now. This will be
8063 -- expanded to represent the true underlying base range by Freeze.
8065 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8067 -- Set size to zero for now, size will be set at freeze time. We have
8068 -- to do this for ordinary fixed-point, because the size depends on
8069 -- the specified small, and we might as well do the same for decimal
8072 Init_Size_Align (Implicit_Base);
8074 -- Complete entity for first subtype
8076 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
8077 Set_Etype (T, Implicit_Base);
8078 Set_Size_Info (T, Implicit_Base);
8079 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
8080 Set_Digits_Value (T, Digs_Val);
8081 Set_Delta_Value (T, Delta_Val);
8082 Set_Small_Value (T, Delta_Val);
8083 Set_Scale_Value (T, Scale_Val);
8084 Set_Is_Constrained (T);
8086 -- If there are bounds given in the declaration use them as the
8087 -- bounds of the first named subtype.
8089 if Present (Real_Range_Specification (Def)) then
8091 RRS : constant Node_Id := Real_Range_Specification (Def);
8092 Low : constant Node_Id := Low_Bound (RRS);
8093 High : constant Node_Id := High_Bound (RRS);
8098 Analyze_And_Resolve (Low, Any_Real);
8099 Analyze_And_Resolve (High, Any_Real);
8100 Check_Real_Bound (Low);
8101 Check_Real_Bound (High);
8102 Low_Val := Expr_Value_R (Low);
8103 High_Val := Expr_Value_R (High);
8105 if Low_Val < (-Bound_Val) then
8107 ("range low bound too small for digits value", Low);
8108 Low_Val := -Bound_Val;
8111 if High_Val > Bound_Val then
8113 ("range high bound too large for digits value", High);
8114 High_Val := Bound_Val;
8117 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
8120 -- If no explicit range, use range that corresponds to given
8121 -- digits value. This will end up as the final range for the
8125 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
8128 end Decimal_Fixed_Point_Type_Declaration;
8130 -----------------------
8131 -- Derive_Subprogram --
8132 -----------------------
8134 procedure Derive_Subprogram
8135 (New_Subp : in out Entity_Id;
8136 Parent_Subp : Entity_Id;
8137 Derived_Type : Entity_Id;
8138 Parent_Type : Entity_Id;
8139 Actual_Subp : Entity_Id := Empty)
8142 New_Formal : Entity_Id;
8143 Same_Subt : constant Boolean :=
8144 Is_Scalar_Type (Parent_Type)
8145 and then Subtypes_Statically_Compatible (Parent_Type, Derived_Type);
8147 function Is_Private_Overriding return Boolean;
8148 -- If Subp is a private overriding of a visible operation, the in-
8149 -- herited operation derives from the overridden op (even though
8150 -- its body is the overriding one) and the inherited operation is
8151 -- visible now. See sem_disp to see the details of the handling of
8152 -- the overridden subprogram, which is removed from the list of
8153 -- primitive operations of the type.
8155 procedure Replace_Type (Id, New_Id : Entity_Id);
8156 -- When the type is an anonymous access type, create a new access type
8157 -- designating the derived type.
8159 ---------------------------
8160 -- Is_Private_Overriding --
8161 ---------------------------
8163 function Is_Private_Overriding return Boolean is
8167 Prev := Homonym (Parent_Subp);
8169 -- The visible operation that is overriden is a homonym of
8170 -- the parent subprogram. We scan the homonym chain to find
8171 -- the one whose alias is the subprogram we are deriving.
8173 while Present (Prev) loop
8174 if Is_Dispatching_Operation (Parent_Subp)
8175 and then Present (Prev)
8176 and then Ekind (Prev) = Ekind (Parent_Subp)
8177 and then Alias (Prev) = Parent_Subp
8178 and then Scope (Parent_Subp) = Scope (Prev)
8179 and then not Is_Hidden (Prev)
8184 Prev := Homonym (Prev);
8188 end Is_Private_Overriding;
8194 procedure Replace_Type (Id, New_Id : Entity_Id) is
8195 Acc_Type : Entity_Id;
8199 -- When the type is an anonymous access type, create a new access
8200 -- type designating the derived type. This itype must be elaborated
8201 -- at the point of the derivation, not on subsequent calls that may
8202 -- be out of the proper scope for Gigi, so we insert a reference to
8203 -- it after the derivation.
8205 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
8207 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
8210 if Ekind (Desig_Typ) = E_Record_Type_With_Private
8211 and then Present (Full_View (Desig_Typ))
8212 and then not Is_Private_Type (Parent_Type)
8214 Desig_Typ := Full_View (Desig_Typ);
8217 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
8218 Acc_Type := New_Copy (Etype (Id));
8219 Set_Etype (Acc_Type, Acc_Type);
8220 Set_Scope (Acc_Type, New_Subp);
8222 -- Compute size of anonymous access type.
8224 if Is_Array_Type (Desig_Typ)
8225 and then not Is_Constrained (Desig_Typ)
8227 Init_Size (Acc_Type, 2 * System_Address_Size);
8229 Init_Size (Acc_Type, System_Address_Size);
8232 Init_Alignment (Acc_Type);
8234 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
8236 Set_Etype (New_Id, Acc_Type);
8237 Set_Scope (New_Id, New_Subp);
8239 -- Create a reference to it.
8241 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
8242 Set_Itype (IR, Acc_Type);
8243 Insert_After (Parent (Derived_Type), IR);
8246 Set_Etype (New_Id, Etype (Id));
8249 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
8251 (Ekind (Etype (Id)) = E_Record_Type_With_Private
8252 and then Present (Full_View (Etype (Id)))
8253 and then Base_Type (Full_View (Etype (Id))) =
8254 Base_Type (Parent_Type))
8257 -- Constraint checks on formals are generated during expansion,
8258 -- based on the signature of the original subprogram. The bounds
8259 -- of the derived type are not relevant, and thus we can use
8260 -- the base type for the formals. However, the return type may be
8261 -- used in a context that requires that the proper static bounds
8262 -- be used (a case statement, for example) and for those cases
8263 -- we must use the derived type (first subtype), not its base.
8265 if Etype (Id) = Parent_Type
8268 Set_Etype (New_Id, Derived_Type);
8270 Set_Etype (New_Id, Base_Type (Derived_Type));
8274 Set_Etype (New_Id, Etype (Id));
8278 -- Start of processing for Derive_Subprogram
8282 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
8283 Set_Ekind (New_Subp, Ekind (Parent_Subp));
8285 -- Check whether the inherited subprogram is a private operation that
8286 -- should be inherited but not yet made visible. Such subprograms can
8287 -- become visible at a later point (e.g., the private part of a public
8288 -- child unit) via Declare_Inherited_Private_Subprograms. If the
8289 -- following predicate is true, then this is not such a private
8290 -- operation and the subprogram simply inherits the name of the parent
8291 -- subprogram. Note the special check for the names of controlled
8292 -- operations, which are currently exempted from being inherited with
8293 -- a hidden name because they must be findable for generation of
8294 -- implicit run-time calls.
8296 if not Is_Hidden (Parent_Subp)
8297 or else Is_Internal (Parent_Subp)
8298 or else Is_Private_Overriding
8299 or else Is_Internal_Name (Chars (Parent_Subp))
8300 or else Chars (Parent_Subp) = Name_Initialize
8301 or else Chars (Parent_Subp) = Name_Adjust
8302 or else Chars (Parent_Subp) = Name_Finalize
8304 Set_Chars (New_Subp, Chars (Parent_Subp));
8306 -- If parent is hidden, this can be a regular derivation if the
8307 -- parent is immediately visible in a non-instantiating context,
8308 -- or if we are in the private part of an instance. This test
8309 -- should still be refined ???
8311 -- The test for In_Instance_Not_Visible avoids inheriting the
8312 -- derived operation as a non-visible operation in cases where
8313 -- the parent subprogram might not be visible now, but was
8314 -- visible within the original generic, so it would be wrong
8315 -- to make the inherited subprogram non-visible now. (Not
8316 -- clear if this test is fully correct; are there any cases
8317 -- where we should declare the inherited operation as not
8318 -- visible to avoid it being overridden, e.g., when the
8319 -- parent type is a generic actual with private primitives ???)
8321 -- (they should be treated the same as other private inherited
8322 -- subprograms, but it's not clear how to do this cleanly). ???
8324 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
8325 and then Is_Immediately_Visible (Parent_Subp)
8326 and then not In_Instance)
8327 or else In_Instance_Not_Visible
8329 Set_Chars (New_Subp, Chars (Parent_Subp));
8331 -- The type is inheriting a private operation, so enter
8332 -- it with a special name so it can't be overridden.
8335 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
8338 Set_Parent (New_Subp, Parent (Derived_Type));
8339 Replace_Type (Parent_Subp, New_Subp);
8340 Conditional_Delay (New_Subp, Parent_Subp);
8342 Formal := First_Formal (Parent_Subp);
8343 while Present (Formal) loop
8344 New_Formal := New_Copy (Formal);
8346 -- Normally we do not go copying parents, but in the case of
8347 -- formals, we need to link up to the declaration (which is
8348 -- the parameter specification), and it is fine to link up to
8349 -- the original formal's parameter specification in this case.
8351 Set_Parent (New_Formal, Parent (Formal));
8353 Append_Entity (New_Formal, New_Subp);
8355 Replace_Type (Formal, New_Formal);
8356 Next_Formal (Formal);
8359 -- If this derivation corresponds to a tagged generic actual, then
8360 -- primitive operations rename those of the actual. Otherwise the
8361 -- primitive operations rename those of the parent type.
8363 if No (Actual_Subp) then
8364 Set_Alias (New_Subp, Parent_Subp);
8365 Set_Is_Intrinsic_Subprogram (New_Subp,
8366 Is_Intrinsic_Subprogram (Parent_Subp));
8369 Set_Alias (New_Subp, Actual_Subp);
8372 -- Derived subprograms of a tagged type must inherit the convention
8373 -- of the parent subprogram (a requirement of AI-117). Derived
8374 -- subprograms of untagged types simply get convention Ada by default.
8376 if Is_Tagged_Type (Derived_Type) then
8377 Set_Convention (New_Subp, Convention (Parent_Subp));
8380 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
8381 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
8383 if Ekind (Parent_Subp) = E_Procedure then
8384 Set_Is_Valued_Procedure
8385 (New_Subp, Is_Valued_Procedure (Parent_Subp));
8388 New_Overloaded_Entity (New_Subp, Derived_Type);
8390 -- Check for case of a derived subprogram for the instantiation
8391 -- of a formal derived tagged type, so mark the subprogram as
8392 -- dispatching and inherit the dispatching attributes of the
8393 -- parent subprogram. The derived subprogram is effectively a
8394 -- renaming of the actual subprogram, so it needs to have the
8395 -- same attributes as the actual.
8397 if Present (Actual_Subp)
8398 and then Is_Dispatching_Operation (Parent_Subp)
8400 Set_Is_Dispatching_Operation (New_Subp);
8401 if Present (DTC_Entity (Parent_Subp)) then
8402 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
8403 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
8407 -- Indicate that a derived subprogram does not require a body
8408 -- and that it does not require processing of default expressions.
8410 Set_Has_Completion (New_Subp);
8411 Set_Default_Expressions_Processed (New_Subp);
8413 -- A derived function with a controlling result is abstract.
8414 -- If the Derived_Type is a nonabstract formal generic derived
8415 -- type, then inherited operations are not abstract: check is
8416 -- done at instantiation time. If the derivation is for a generic
8417 -- actual, the function is not abstract unless the actual is.
8419 if Is_Generic_Type (Derived_Type)
8420 and then not Is_Abstract (Derived_Type)
8424 elsif Is_Abstract (Alias (New_Subp))
8425 or else (Is_Tagged_Type (Derived_Type)
8426 and then Etype (New_Subp) = Derived_Type
8427 and then No (Actual_Subp))
8429 Set_Is_Abstract (New_Subp);
8432 if Ekind (New_Subp) = E_Function then
8433 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
8435 end Derive_Subprogram;
8437 ------------------------
8438 -- Derive_Subprograms --
8439 ------------------------
8441 procedure Derive_Subprograms
8442 (Parent_Type : Entity_Id;
8443 Derived_Type : Entity_Id;
8444 Generic_Actual : Entity_Id := Empty)
8446 Op_List : Elist_Id := Collect_Primitive_Operations (Parent_Type);
8447 Act_List : Elist_Id;
8451 New_Subp : Entity_Id := Empty;
8452 Parent_Base : Entity_Id;
8455 if Ekind (Parent_Type) = E_Record_Type_With_Private
8456 and then Has_Discriminants (Parent_Type)
8457 and then Present (Full_View (Parent_Type))
8459 Parent_Base := Full_View (Parent_Type);
8461 Parent_Base := Parent_Type;
8464 Elmt := First_Elmt (Op_List);
8466 if Present (Generic_Actual) then
8467 Act_List := Collect_Primitive_Operations (Generic_Actual);
8468 Act_Elmt := First_Elmt (Act_List);
8470 Act_Elmt := No_Elmt;
8473 -- Literals are derived earlier in the process of building the
8474 -- derived type, and are skipped here.
8476 while Present (Elmt) loop
8477 Subp := Node (Elmt);
8479 if Ekind (Subp) /= E_Enumeration_Literal then
8480 if No (Generic_Actual) then
8482 (New_Subp, Subp, Derived_Type, Parent_Base);
8485 Derive_Subprogram (New_Subp, Subp,
8486 Derived_Type, Parent_Base, Node (Act_Elmt));
8487 Next_Elmt (Act_Elmt);
8493 end Derive_Subprograms;
8495 --------------------------------
8496 -- Derived_Standard_Character --
8497 --------------------------------
8499 procedure Derived_Standard_Character
8501 Parent_Type : Entity_Id;
8502 Derived_Type : Entity_Id)
8504 Loc : constant Source_Ptr := Sloc (N);
8505 Def : constant Node_Id := Type_Definition (N);
8506 Indic : constant Node_Id := Subtype_Indication (Def);
8507 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8508 Implicit_Base : constant Entity_Id :=
8510 (E_Enumeration_Type, N, Derived_Type, 'B');
8517 T := Process_Subtype (Indic, N);
8519 Set_Etype (Implicit_Base, Parent_Base);
8520 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
8521 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
8523 Set_Is_Character_Type (Implicit_Base, True);
8524 Set_Has_Delayed_Freeze (Implicit_Base);
8526 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
8527 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
8529 Set_Scalar_Range (Implicit_Base,
8534 Conditional_Delay (Derived_Type, Parent_Type);
8536 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
8537 Set_Etype (Derived_Type, Implicit_Base);
8538 Set_Size_Info (Derived_Type, Parent_Type);
8540 if Unknown_RM_Size (Derived_Type) then
8541 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8544 Set_Is_Character_Type (Derived_Type, True);
8546 if Nkind (Indic) /= N_Subtype_Indication then
8547 Set_Scalar_Range (Derived_Type, Scalar_Range (Implicit_Base));
8550 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
8552 -- Because the implicit base is used in the conversion of the bounds,
8553 -- we have to freeze it now. This is similar to what is done for
8554 -- numeric types, and it equally suspicious, but otherwise a non-
8555 -- static bound will have a reference to an unfrozen type, which is
8556 -- rejected by Gigi (???).
8558 Freeze_Before (N, Implicit_Base);
8560 end Derived_Standard_Character;
8562 ------------------------------
8563 -- Derived_Type_Declaration --
8564 ------------------------------
8566 procedure Derived_Type_Declaration
8569 Is_Completion : Boolean)
8571 Def : constant Node_Id := Type_Definition (N);
8572 Indic : constant Node_Id := Subtype_Indication (Def);
8573 Extension : constant Node_Id := Record_Extension_Part (Def);
8574 Parent_Type : Entity_Id;
8575 Parent_Scope : Entity_Id;
8579 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
8581 if Parent_Type = Any_Type
8582 or else Etype (Parent_Type) = Any_Type
8583 or else (Is_Class_Wide_Type (Parent_Type)
8584 and then Etype (Parent_Type) = T)
8586 -- If Parent_Type is undefined or illegal, make new type into
8587 -- a subtype of Any_Type, and set a few attributes to prevent
8588 -- cascaded errors. If this is a self-definition, emit error now.
8591 or else T = Etype (Parent_Type)
8593 Error_Msg_N ("type cannot be used in its own definition", Indic);
8596 Set_Ekind (T, Ekind (Parent_Type));
8597 Set_Etype (T, Any_Type);
8598 Set_Scalar_Range (T, Scalar_Range (Any_Type));
8600 if Is_Tagged_Type (T) then
8601 Set_Primitive_Operations (T, New_Elmt_List);
8605 elsif Is_Unchecked_Union (Parent_Type) then
8606 Error_Msg_N ("cannot derive from Unchecked_Union type", N);
8609 -- Only composite types other than array types are allowed to have
8612 if Present (Discriminant_Specifications (N))
8613 and then (Is_Elementary_Type (Parent_Type)
8614 or else Is_Array_Type (Parent_Type))
8615 and then not Error_Posted (N)
8618 ("elementary or array type cannot have discriminants",
8619 Defining_Identifier (First (Discriminant_Specifications (N))));
8620 Set_Has_Discriminants (T, False);
8623 -- In Ada 83, a derived type defined in a package specification cannot
8624 -- be used for further derivation until the end of its visible part.
8625 -- Note that derivation in the private part of the package is allowed.
8628 and then Is_Derived_Type (Parent_Type)
8629 and then In_Visible_Part (Scope (Parent_Type))
8631 if Ada_83 and then Comes_From_Source (Indic) then
8633 ("(Ada 83): premature use of type for derivation", Indic);
8637 -- Check for early use of incomplete or private type
8639 if Ekind (Parent_Type) = E_Void
8640 or else Ekind (Parent_Type) = E_Incomplete_Type
8642 Error_Msg_N ("premature derivation of incomplete type", Indic);
8645 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
8646 and then not Is_Generic_Type (Parent_Type)
8647 and then not Is_Generic_Type (Root_Type (Parent_Type))
8648 and then not Is_Generic_Actual_Type (Parent_Type))
8649 or else Has_Private_Component (Parent_Type)
8651 -- The ancestor type of a formal type can be incomplete, in which
8652 -- case only the operations of the partial view are available in
8653 -- the generic. Subsequent checks may be required when the full
8654 -- view is analyzed, to verify that derivation from a tagged type
8655 -- has an extension.
8657 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
8660 elsif No (Underlying_Type (Parent_Type))
8661 or else Has_Private_Component (Parent_Type)
8664 ("premature derivation of derived or private type", Indic);
8666 -- Flag the type itself as being in error, this prevents some
8667 -- nasty problems with people looking at the malformed type.
8669 Set_Error_Posted (T);
8671 -- Check that within the immediate scope of an untagged partial
8672 -- view it's illegal to derive from the partial view if the
8673 -- full view is tagged. (7.3(7))
8675 -- We verify that the Parent_Type is a partial view by checking
8676 -- that it is not a Full_Type_Declaration (i.e. a private type or
8677 -- private extension declaration), to distinguish a partial view
8678 -- from a derivation from a private type which also appears as
8681 elsif Present (Full_View (Parent_Type))
8682 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
8683 and then not Is_Tagged_Type (Parent_Type)
8684 and then Is_Tagged_Type (Full_View (Parent_Type))
8686 Parent_Scope := Scope (T);
8687 while Present (Parent_Scope)
8688 and then Parent_Scope /= Standard_Standard
8690 if Parent_Scope = Scope (Parent_Type) then
8692 ("premature derivation from type with tagged full view",
8696 Parent_Scope := Scope (Parent_Scope);
8701 -- Check that form of derivation is appropriate
8703 Taggd := Is_Tagged_Type (Parent_Type);
8705 -- Perhaps the parent type should be changed to the class-wide type's
8706 -- specific type in this case to prevent cascading errors ???
8708 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
8709 Error_Msg_N ("parent type must not be a class-wide type", Indic);
8713 if Present (Extension) and then not Taggd then
8715 ("type derived from untagged type cannot have extension", Indic);
8717 elsif No (Extension) and then Taggd then
8718 -- If this is within a private part (or body) of a generic
8719 -- instantiation then the derivation is allowed (the parent
8720 -- type can only appear tagged in this case if it's a generic
8721 -- actual type, since it would otherwise have been rejected
8722 -- in the analysis of the generic template).
8724 if not Is_Generic_Actual_Type (Parent_Type)
8725 or else In_Visible_Part (Scope (Parent_Type))
8728 ("type derived from tagged type must have extension", Indic);
8732 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
8733 end Derived_Type_Declaration;
8735 ----------------------------------
8736 -- Enumeration_Type_Declaration --
8737 ----------------------------------
8739 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
8746 -- Create identifier node representing lower bound
8748 B_Node := New_Node (N_Identifier, Sloc (Def));
8749 L := First (Literals (Def));
8750 Set_Chars (B_Node, Chars (L));
8751 Set_Entity (B_Node, L);
8752 Set_Etype (B_Node, T);
8753 Set_Is_Static_Expression (B_Node, True);
8755 R_Node := New_Node (N_Range, Sloc (Def));
8756 Set_Low_Bound (R_Node, B_Node);
8758 Set_Ekind (T, E_Enumeration_Type);
8759 Set_First_Literal (T, L);
8761 Set_Is_Constrained (T);
8765 -- Loop through literals of enumeration type setting pos and rep values
8766 -- except that if the Ekind is already set, then it means that the
8767 -- literal was already constructed (case of a derived type declaration
8768 -- and we should not disturb the Pos and Rep values.
8770 while Present (L) loop
8771 if Ekind (L) /= E_Enumeration_Literal then
8772 Set_Ekind (L, E_Enumeration_Literal);
8773 Set_Enumeration_Pos (L, Ev);
8774 Set_Enumeration_Rep (L, Ev);
8775 Set_Is_Known_Valid (L, True);
8779 New_Overloaded_Entity (L);
8780 Generate_Definition (L);
8781 Set_Convention (L, Convention_Intrinsic);
8783 if Nkind (L) = N_Defining_Character_Literal then
8784 Set_Is_Character_Type (T, True);
8791 -- Now create a node representing upper bound
8793 B_Node := New_Node (N_Identifier, Sloc (Def));
8794 Set_Chars (B_Node, Chars (Last (Literals (Def))));
8795 Set_Entity (B_Node, Last (Literals (Def)));
8796 Set_Etype (B_Node, T);
8797 Set_Is_Static_Expression (B_Node, True);
8799 Set_High_Bound (R_Node, B_Node);
8800 Set_Scalar_Range (T, R_Node);
8801 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
8804 -- Set Discard_Names if configuration pragma setg, or if there is
8805 -- a parameterless pragma in the current declarative region
8807 if Global_Discard_Names
8808 or else Discard_Names (Scope (T))
8810 Set_Discard_Names (T);
8812 end Enumeration_Type_Declaration;
8814 --------------------------
8815 -- Expand_Others_Choice --
8816 --------------------------
8818 procedure Expand_Others_Choice
8819 (Case_Table : Choice_Table_Type;
8820 Others_Choice : Node_Id;
8821 Choice_Type : Entity_Id)
8824 Choice_List : List_Id := New_List;
8829 Loc : Source_Ptr := Sloc (Others_Choice);
8832 function Build_Choice (Value1, Value2 : Uint) return Node_Id;
8833 -- Builds a node representing the missing choices given by the
8834 -- Value1 and Value2. A N_Range node is built if there is more than
8835 -- one literal value missing. Otherwise a single N_Integer_Literal,
8836 -- N_Identifier or N_Character_Literal is built depending on what
8839 function Lit_Of (Value : Uint) return Node_Id;
8840 -- Returns the Node_Id for the enumeration literal corresponding to the
8841 -- position given by Value within the enumeration type Choice_Type.
8847 function Build_Choice (Value1, Value2 : Uint) return Node_Id is
8852 -- If there is only one choice value missing between Value1 and
8853 -- Value2, build an integer or enumeration literal to represent it.
8855 if (Value2 - Value1) = 0 then
8856 if Is_Integer_Type (Choice_Type) then
8857 Lit_Node := Make_Integer_Literal (Loc, Value1);
8858 Set_Etype (Lit_Node, Choice_Type);
8860 Lit_Node := Lit_Of (Value1);
8863 -- Otherwise is more that one choice value that is missing between
8864 -- Value1 and Value2, therefore build a N_Range node of either
8865 -- integer or enumeration literals.
8868 if Is_Integer_Type (Choice_Type) then
8869 Lo := Make_Integer_Literal (Loc, Value1);
8870 Set_Etype (Lo, Choice_Type);
8871 Hi := Make_Integer_Literal (Loc, Value2);
8872 Set_Etype (Hi, Choice_Type);
8881 Low_Bound => Lit_Of (Value1),
8882 High_Bound => Lit_Of (Value2));
8893 function Lit_Of (Value : Uint) return Node_Id is
8897 -- In the case where the literal is of type Character, there needs
8898 -- to be some special handling since there is no explicit chain
8899 -- of literals to search. Instead, a N_Character_Literal node
8900 -- is created with the appropriate Char_Code and Chars fields.
8902 if Root_Type (Choice_Type) = Standard_Character then
8903 Set_Character_Literal_Name (Char_Code (UI_To_Int (Value)));
8904 Lit := New_Node (N_Character_Literal, Loc);
8905 Set_Chars (Lit, Name_Find);
8906 Set_Char_Literal_Value (Lit, Char_Code (UI_To_Int (Value)));
8907 Set_Etype (Lit, Choice_Type);
8908 Set_Is_Static_Expression (Lit, True);
8911 -- Otherwise, iterate through the literals list of Choice_Type
8912 -- "Value" number of times until the desired literal is reached
8913 -- and then return an occurrence of it.
8916 Lit := First_Literal (Choice_Type);
8917 for J in 1 .. UI_To_Int (Value) loop
8921 return New_Occurrence_Of (Lit, Loc);
8925 -- Start of processing for Expand_Others_Choice
8928 if Case_Table'Length = 0 then
8930 -- Pathological case: only an others case is present.
8931 -- The others case covers the full range of the type.
8933 if Is_Static_Subtype (Choice_Type) then
8934 Choice := New_Occurrence_Of (Choice_Type, Loc);
8936 Choice := New_Occurrence_Of (Base_Type (Choice_Type), Loc);
8939 Set_Others_Discrete_Choices (Others_Choice, New_List (Choice));
8943 -- Establish the bound values for the variant depending upon whether
8944 -- the type of the discriminant name is static or not.
8946 if Is_OK_Static_Subtype (Choice_Type) then
8947 Exp_Lo := Type_Low_Bound (Choice_Type);
8948 Exp_Hi := Type_High_Bound (Choice_Type);
8950 Exp_Lo := Type_Low_Bound (Base_Type (Choice_Type));
8951 Exp_Hi := Type_High_Bound (Base_Type (Choice_Type));
8954 Lo := Expr_Value (Case_Table (Case_Table'First).Lo);
8955 Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8956 Previous_Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8958 -- Build the node for any missing choices that are smaller than any
8959 -- explicit choices given in the variant.
8961 if Expr_Value (Exp_Lo) < Lo then
8962 Append (Build_Choice (Expr_Value (Exp_Lo), Lo - 1), Choice_List);
8965 -- Build the nodes representing any missing choices that lie between
8966 -- the explicit ones given in the variant.
8968 for J in Case_Table'First + 1 .. Case_Table'Last loop
8969 Lo := Expr_Value (Case_Table (J).Lo);
8970 Hi := Expr_Value (Case_Table (J).Hi);
8972 if Lo /= (Previous_Hi + 1) then
8973 Append_To (Choice_List, Build_Choice (Previous_Hi + 1, Lo - 1));
8979 -- Build the node for any missing choices that are greater than any
8980 -- explicit choices given in the variant.
8982 if Expr_Value (Exp_Hi) > Hi then
8983 Append (Build_Choice (Hi + 1, Expr_Value (Exp_Hi)), Choice_List);
8986 Set_Others_Discrete_Choices (Others_Choice, Choice_List);
8987 end Expand_Others_Choice;
8989 ---------------------------------
8990 -- Expand_To_Girder_Constraint --
8991 ---------------------------------
8993 function Expand_To_Girder_Constraint
8995 Constraint : Elist_Id)
8998 Explicitly_Discriminated_Type : Entity_Id;
8999 Expansion : Elist_Id;
9000 Discriminant : Entity_Id;
9002 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
9003 -- Find the nearest type that actually specifies discriminants.
9005 ---------------------------------
9006 -- Type_With_Explicit_Discrims --
9007 ---------------------------------
9009 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
9010 Typ : constant E := Base_Type (Id);
9013 if Ekind (Typ) in Incomplete_Or_Private_Kind then
9014 if Present (Full_View (Typ)) then
9015 return Type_With_Explicit_Discrims (Full_View (Typ));
9019 if Has_Discriminants (Typ) then
9024 if Etype (Typ) = Typ then
9026 elsif Has_Discriminants (Typ) then
9029 return Type_With_Explicit_Discrims (Etype (Typ));
9032 end Type_With_Explicit_Discrims;
9034 -- Start of processing for Expand_To_Girder_Constraint
9038 or else Is_Empty_Elmt_List (Constraint)
9043 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
9045 if No (Explicitly_Discriminated_Type) then
9049 Expansion := New_Elmt_List;
9052 First_Girder_Discriminant (Explicitly_Discriminated_Type);
9054 while Present (Discriminant) loop
9057 Get_Discriminant_Value (
9058 Discriminant, Explicitly_Discriminated_Type, Constraint),
9061 Next_Girder_Discriminant (Discriminant);
9065 end Expand_To_Girder_Constraint;
9067 --------------------
9068 -- Find_Type_Name --
9069 --------------------
9071 function Find_Type_Name (N : Node_Id) return Entity_Id is
9072 Id : constant Entity_Id := Defining_Identifier (N);
9078 -- Find incomplete declaration, if some was given.
9080 Prev := Current_Entity_In_Scope (Id);
9082 if Present (Prev) then
9084 -- Previous declaration exists. Error if not incomplete/private case
9085 -- except if previous declaration is implicit, etc. Enter_Name will
9086 -- emit error if appropriate.
9088 Prev_Par := Parent (Prev);
9090 if not Is_Incomplete_Or_Private_Type (Prev) then
9094 elsif Nkind (N) /= N_Full_Type_Declaration
9095 and then Nkind (N) /= N_Task_Type_Declaration
9096 and then Nkind (N) /= N_Protected_Type_Declaration
9098 -- Completion must be a full type declarations (RM 7.3(4))
9100 Error_Msg_Sloc := Sloc (Prev);
9101 Error_Msg_NE ("invalid completion of }", Id, Prev);
9103 -- Set scope of Id to avoid cascaded errors. Entity is never
9104 -- examined again, except when saving globals in generics.
9106 Set_Scope (Id, Current_Scope);
9109 -- Case of full declaration of incomplete type
9111 elsif Ekind (Prev) = E_Incomplete_Type then
9113 -- Indicate that the incomplete declaration has a matching
9114 -- full declaration. The defining occurrence of the incomplete
9115 -- declaration remains the visible one, and the procedure
9116 -- Get_Full_View dereferences it whenever the type is used.
9118 if Present (Full_View (Prev)) then
9119 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9122 Set_Full_View (Prev, Id);
9123 Append_Entity (Id, Current_Scope);
9124 Set_Is_Public (Id, Is_Public (Prev));
9125 Set_Is_Internal (Id);
9128 -- Case of full declaration of private type
9131 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9132 if Etype (Prev) /= Prev then
9134 -- Prev is a private subtype or a derived type, and needs
9137 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9140 elsif Ekind (Prev) = E_Private_Type
9142 (Nkind (N) = N_Task_Type_Declaration
9143 or else Nkind (N) = N_Protected_Type_Declaration)
9146 ("completion of nonlimited type cannot be limited", N);
9149 elsif Nkind (N) /= N_Full_Type_Declaration
9150 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9152 Error_Msg_N ("full view of private extension must be"
9153 & " an extension", N);
9155 elsif not (Abstract_Present (Parent (Prev)))
9156 and then Abstract_Present (Type_Definition (N))
9158 Error_Msg_N ("full view of non-abstract extension cannot"
9159 & " be abstract", N);
9162 if not In_Private_Part (Current_Scope) then
9164 ("declaration of full view must appear in private part", N);
9167 Copy_And_Swap (Prev, Id);
9168 Set_Full_View (Id, Prev);
9169 Set_Has_Private_Declaration (Prev);
9170 Set_Has_Private_Declaration (Id);
9174 -- Verify that full declaration conforms to incomplete one
9176 if Is_Incomplete_Or_Private_Type (Prev)
9177 and then Present (Discriminant_Specifications (Prev_Par))
9179 if Present (Discriminant_Specifications (N)) then
9180 if Ekind (Prev) = E_Incomplete_Type then
9181 Check_Discriminant_Conformance (N, Prev, Prev);
9183 Check_Discriminant_Conformance (N, Prev, Id);
9188 ("missing discriminants in full type declaration", N);
9190 -- To avoid cascaded errors on subsequent use, share the
9191 -- discriminants of the partial view.
9193 Set_Discriminant_Specifications (N,
9194 Discriminant_Specifications (Prev_Par));
9198 -- A prior untagged private type can have an associated
9199 -- class-wide type due to use of the class attribute,
9200 -- and in this case also the full type is required to
9204 and then (Is_Tagged_Type (Prev)
9205 or else Present (Class_Wide_Type (Prev)))
9207 -- The full declaration is either a tagged record or an
9208 -- extension otherwise this is an error
9210 if Nkind (Type_Definition (N)) = N_Record_Definition then
9211 if not Tagged_Present (Type_Definition (N)) then
9213 ("full declaration of } must be tagged", Prev, Id);
9214 Set_Is_Tagged_Type (Id);
9215 Set_Primitive_Operations (Id, New_Elmt_List);
9218 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
9219 if No (Record_Extension_Part (Type_Definition (N))) then
9221 "full declaration of } must be a record extension",
9223 Set_Is_Tagged_Type (Id);
9224 Set_Primitive_Operations (Id, New_Elmt_List);
9229 ("full declaration of } must be a tagged type", Prev, Id);
9237 -- New type declaration
9244 -------------------------
9245 -- Find_Type_Of_Object --
9246 -------------------------
9248 function Find_Type_Of_Object
9250 Related_Nod : Node_Id)
9253 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
9254 P : constant Node_Id := Parent (Obj_Def);
9259 -- Case of an anonymous array subtype
9261 if Def_Kind = N_Constrained_Array_Definition
9262 or else Def_Kind = N_Unconstrained_Array_Definition
9265 Array_Type_Declaration (T, Obj_Def);
9267 -- Create an explicit subtype whenever possible.
9269 elsif Nkind (P) /= N_Component_Declaration
9270 and then Def_Kind = N_Subtype_Indication
9272 -- Base name of subtype on object name, which will be unique in
9273 -- the current scope.
9275 -- If this is a duplicate declaration, return base type, to avoid
9276 -- generating duplicate anonymous types.
9278 if Error_Posted (P) then
9279 Analyze (Subtype_Mark (Obj_Def));
9280 return Entity (Subtype_Mark (Obj_Def));
9285 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
9287 T := Make_Defining_Identifier (Sloc (P), Nam);
9289 Insert_Action (Obj_Def,
9290 Make_Subtype_Declaration (Sloc (P),
9291 Defining_Identifier => T,
9292 Subtype_Indication => Relocate_Node (Obj_Def)));
9294 -- This subtype may need freezing and it will not be done
9295 -- automatically if the object declaration is not in a
9296 -- declarative part. Since this is an object declaration, the
9297 -- type cannot always be frozen here. Deferred constants do not
9298 -- freeze their type (which often enough will be private).
9300 if Nkind (P) = N_Object_Declaration
9301 and then Constant_Present (P)
9302 and then No (Expression (P))
9307 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
9311 T := Process_Subtype (Obj_Def, Related_Nod);
9315 end Find_Type_Of_Object;
9317 --------------------------------
9318 -- Find_Type_Of_Subtype_Indic --
9319 --------------------------------
9321 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
9325 -- Case of subtype mark with a constraint
9327 if Nkind (S) = N_Subtype_Indication then
9328 Find_Type (Subtype_Mark (S));
9329 Typ := Entity (Subtype_Mark (S));
9332 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
9335 ("incorrect constraint for this kind of type", Constraint (S));
9336 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
9339 -- Otherwise we have a subtype mark without a constraint
9341 elsif Error_Posted (S) then
9342 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
9350 if Typ = Standard_Wide_Character
9351 or else Typ = Standard_Wide_String
9353 Check_Restriction (No_Wide_Characters, S);
9357 end Find_Type_Of_Subtype_Indic;
9359 -------------------------------------
9360 -- Floating_Point_Type_Declaration --
9361 -------------------------------------
9363 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9364 Digs : constant Node_Id := Digits_Expression (Def);
9366 Base_Typ : Entity_Id;
9367 Implicit_Base : Entity_Id;
9370 function Can_Derive_From (E : Entity_Id) return Boolean;
9371 -- Find if given digits value allows derivation from specified type
9373 function Can_Derive_From (E : Entity_Id) return Boolean is
9374 Spec : constant Entity_Id := Real_Range_Specification (Def);
9377 if Digs_Val > Digits_Value (E) then
9381 if Present (Spec) then
9382 if Expr_Value_R (Type_Low_Bound (E)) >
9383 Expr_Value_R (Low_Bound (Spec))
9388 if Expr_Value_R (Type_High_Bound (E)) <
9389 Expr_Value_R (High_Bound (Spec))
9396 end Can_Derive_From;
9398 -- Start of processing for Floating_Point_Type_Declaration
9401 Check_Restriction (No_Floating_Point, Def);
9403 -- Create an implicit base type
9406 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
9408 -- Analyze and verify digits value
9410 Analyze_And_Resolve (Digs, Any_Integer);
9411 Check_Digits_Expression (Digs);
9412 Digs_Val := Expr_Value (Digs);
9414 -- Process possible range spec and find correct type to derive from
9416 Process_Real_Range_Specification (Def);
9418 if Can_Derive_From (Standard_Short_Float) then
9419 Base_Typ := Standard_Short_Float;
9420 elsif Can_Derive_From (Standard_Float) then
9421 Base_Typ := Standard_Float;
9422 elsif Can_Derive_From (Standard_Long_Float) then
9423 Base_Typ := Standard_Long_Float;
9424 elsif Can_Derive_From (Standard_Long_Long_Float) then
9425 Base_Typ := Standard_Long_Long_Float;
9427 -- If we can't derive from any existing type, use long long float
9428 -- and give appropriate message explaining the problem.
9431 Base_Typ := Standard_Long_Long_Float;
9433 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
9434 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
9435 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
9439 ("range too large for any predefined type",
9440 Real_Range_Specification (Def));
9444 -- If there are bounds given in the declaration use them as the bounds
9445 -- of the type, otherwise use the bounds of the predefined base type
9446 -- that was chosen based on the Digits value.
9448 if Present (Real_Range_Specification (Def)) then
9449 Set_Scalar_Range (T, Real_Range_Specification (Def));
9450 Set_Is_Constrained (T);
9452 -- The bounds of this range must be converted to machine numbers
9453 -- in accordance with RM 4.9(38).
9455 Bound := Type_Low_Bound (T);
9457 if Nkind (Bound) = N_Real_Literal then
9458 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9459 Set_Is_Machine_Number (Bound);
9462 Bound := Type_High_Bound (T);
9464 if Nkind (Bound) = N_Real_Literal then
9465 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9466 Set_Is_Machine_Number (Bound);
9470 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
9473 -- Complete definition of implicit base and declared first subtype
9475 Set_Etype (Implicit_Base, Base_Typ);
9477 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
9478 Set_Size_Info (Implicit_Base, (Base_Typ));
9479 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
9480 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
9481 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
9482 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
9484 Set_Ekind (T, E_Floating_Point_Subtype);
9485 Set_Etype (T, Implicit_Base);
9487 Set_Size_Info (T, (Implicit_Base));
9488 Set_RM_Size (T, RM_Size (Implicit_Base));
9489 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
9490 Set_Digits_Value (T, Digs_Val);
9492 end Floating_Point_Type_Declaration;
9494 ----------------------------
9495 -- Get_Discriminant_Value --
9496 ----------------------------
9498 -- This is the situation...
9500 -- There is a non-derived type
9502 -- type T0 (Dx, Dy, Dz...)
9504 -- There are zero or more levels of derivation, with each
9505 -- derivation either purely inheriting the discriminants, or
9506 -- defining its own.
9508 -- type Ti is new Ti-1
9510 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
9512 -- subtype Ti is ...
9514 -- The subtype issue is avoided by the use of
9515 -- Original_Record_Component, and the fact that derived subtypes
9516 -- also derive the constraits.
9518 -- This chain leads back from
9520 -- Typ_For_Constraint
9522 -- Typ_For_Constraint has discriminants, and the value for each
9523 -- discriminant is given by its corresponding Elmt of Constraints.
9525 -- Discriminant is some discriminant in this hierarchy.
9527 -- We need to return its value.
9529 -- We do this by recursively searching each level, and looking for
9530 -- Discriminant. Once we get to the bottom, we start backing up
9531 -- returning the value for it which may in turn be a discriminant
9532 -- further up, so on the backup we continue the substitution.
9534 function Get_Discriminant_Value
9535 (Discriminant : Entity_Id;
9536 Typ_For_Constraint : Entity_Id;
9537 Constraint : Elist_Id)
9542 Discrim_Values : Elist_Id;
9543 Girder_Discrim_Values : Boolean)
9544 return Node_Or_Entity_Id;
9545 -- This is the routine that performs the recursive search of levels
9546 -- as described above.
9550 Discrim_Values : Elist_Id;
9551 Girder_Discrim_Values : Boolean)
9552 return Node_Or_Entity_Id
9556 Result : Node_Or_Entity_Id;
9557 Result_Entity : Node_Id;
9560 -- If inappropriate type, return Error, this happens only in
9561 -- cascaded error situations, and we want to avoid a blow up.
9563 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
9567 -- Look deeper if possible. Use Girder_Constraints only for
9568 -- untagged types. For tagged types use the given constraint.
9569 -- This asymmetry needs explanation???
9571 if not Girder_Discrim_Values
9572 and then Present (Girder_Constraint (Ti))
9573 and then not Is_Tagged_Type (Ti)
9575 Result := Recurse (Ti, Girder_Constraint (Ti), True);
9578 Td : Entity_Id := Etype (Ti);
9582 Result := Discriminant;
9585 if Present (Girder_Constraint (Ti)) then
9587 Recurse (Td, Girder_Constraint (Ti), True);
9590 Recurse (Td, Discrim_Values, Girder_Discrim_Values);
9596 -- Extra underlying places to search, if not found above. For
9597 -- concurrent types, the relevant discriminant appears in the
9598 -- corresponding record. For a type derived from a private type
9599 -- without discriminant, the full view inherits the discriminants
9600 -- of the full view of the parent.
9602 if Result = Discriminant then
9603 if Is_Concurrent_Type (Ti)
9604 and then Present (Corresponding_Record_Type (Ti))
9608 Corresponding_Record_Type (Ti),
9610 Girder_Discrim_Values);
9612 elsif Is_Private_Type (Ti)
9613 and then not Has_Discriminants (Ti)
9614 and then Present (Full_View (Ti))
9615 and then Etype (Full_View (Ti)) /= Ti
9621 Girder_Discrim_Values);
9625 -- If Result is not a (reference to a) discriminant,
9626 -- return it, otherwise set Result_Entity to the discriminant.
9628 if Nkind (Result) = N_Defining_Identifier then
9630 pragma Assert (Result = Discriminant);
9632 Result_Entity := Result;
9635 if not Denotes_Discriminant (Result) then
9639 Result_Entity := Entity (Result);
9642 -- See if this level of derivation actually has discriminants
9643 -- because tagged derivations can add them, hence the lower
9644 -- levels need not have any.
9646 if not Has_Discriminants (Ti) then
9650 -- Scan Ti's discriminants for Result_Entity,
9651 -- and return its corresponding value, if any.
9653 Result_Entity := Original_Record_Component (Result_Entity);
9655 Assoc := First_Elmt (Discrim_Values);
9657 if Girder_Discrim_Values then
9658 Disc := First_Girder_Discriminant (Ti);
9660 Disc := First_Discriminant (Ti);
9663 while Present (Disc) loop
9665 pragma Assert (Present (Assoc));
9667 if Original_Record_Component (Disc) = Result_Entity then
9668 return Node (Assoc);
9673 if Girder_Discrim_Values then
9674 Next_Girder_Discriminant (Disc);
9676 Next_Discriminant (Disc);
9680 -- Could not find it
9685 Result : Node_Or_Entity_Id;
9687 -- Start of processing for Get_Discriminant_Value
9690 -- ??? this routine is a gigantic mess and will be deleted.
9691 -- for the time being just test for the trivial case before calling
9694 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
9696 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9697 E : Elmt_Id := First_Elmt (Constraint);
9699 while Present (D) loop
9700 if Chars (D) = Chars (Discriminant) then
9704 Next_Discriminant (D);
9710 Result := Recurse (Typ_For_Constraint, Constraint, False);
9712 -- ??? hack to disappear when this routine is gone
9714 if Nkind (Result) = N_Defining_Identifier then
9716 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9717 E : Elmt_Id := First_Elmt (Constraint);
9719 while Present (D) loop
9720 if Corresponding_Discriminant (D) = Discriminant then
9724 Next_Discriminant (D);
9730 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
9732 end Get_Discriminant_Value;
9734 --------------------------
9735 -- Has_Range_Constraint --
9736 --------------------------
9738 function Has_Range_Constraint (N : Node_Id) return Boolean is
9739 C : constant Node_Id := Constraint (N);
9742 if Nkind (C) = N_Range_Constraint then
9745 elsif Nkind (C) = N_Digits_Constraint then
9747 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
9749 Present (Range_Constraint (C));
9751 elsif Nkind (C) = N_Delta_Constraint then
9752 return Present (Range_Constraint (C));
9757 end Has_Range_Constraint;
9759 ------------------------
9760 -- Inherit_Components --
9761 ------------------------
9763 function Inherit_Components
9765 Parent_Base : Entity_Id;
9766 Derived_Base : Entity_Id;
9767 Is_Tagged : Boolean;
9768 Inherit_Discr : Boolean;
9772 Assoc_List : Elist_Id := New_Elmt_List;
9774 procedure Inherit_Component
9776 Plain_Discrim : Boolean := False;
9777 Girder_Discrim : Boolean := False);
9778 -- Inherits component Old_C from Parent_Base to the Derived_Base.
9779 -- If Plain_Discrim is True, Old_C is a discriminant.
9780 -- If Girder_Discrim is True, Old_C is a girder discriminant.
9781 -- If they are both false then Old_C is a regular component.
9783 -----------------------
9784 -- Inherit_Component --
9785 -----------------------
9787 procedure Inherit_Component
9789 Plain_Discrim : Boolean := False;
9790 Girder_Discrim : Boolean := False)
9792 New_C : Entity_Id := New_Copy (Old_C);
9794 Discrim : Entity_Id;
9795 Corr_Discrim : Entity_Id;
9798 pragma Assert (not Is_Tagged or else not Girder_Discrim);
9800 Set_Parent (New_C, Parent (Old_C));
9802 -- Regular discriminants and components must be inserted
9803 -- in the scope of the Derived_Base. Do it here.
9805 if not Girder_Discrim then
9809 -- For tagged types the Original_Record_Component must point to
9810 -- whatever this field was pointing to in the parent type. This has
9811 -- already been achieved by the call to New_Copy above.
9813 if not Is_Tagged then
9814 Set_Original_Record_Component (New_C, New_C);
9817 -- If we have inherited a component then see if its Etype contains
9818 -- references to Parent_Base discriminants. In this case, replace
9819 -- these references with the constraints given in Discs. We do not
9820 -- do this for the partial view of private types because this is
9821 -- not needed (only the components of the full view will be used
9822 -- for code generation) and cause problem. We also avoid this
9823 -- transformation in some error situations.
9825 if Ekind (New_C) = E_Component then
9826 if (Is_Private_Type (Derived_Base)
9827 and then not Is_Generic_Type (Derived_Base))
9828 or else (Is_Empty_Elmt_List (Discs)
9829 and then not Expander_Active)
9831 Set_Etype (New_C, Etype (Old_C));
9833 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
9834 Derived_Base, N, Parent_Base, Discs));
9838 -- In derived tagged types it is illegal to reference a non
9839 -- discriminant component in the parent type. To catch this, mark
9840 -- these components with an Ekind of E_Void. This will be reset in
9841 -- Record_Type_Definition after processing the record extension of
9842 -- the derived type.
9844 if Is_Tagged and then Ekind (New_C) = E_Component then
9845 Set_Ekind (New_C, E_Void);
9848 if Plain_Discrim then
9849 Set_Corresponding_Discriminant (New_C, Old_C);
9850 Build_Discriminal (New_C);
9852 -- If we are explicitely inheriting a girder discriminant it will be
9853 -- completely hidden.
9855 elsif Girder_Discrim then
9856 Set_Corresponding_Discriminant (New_C, Empty);
9857 Set_Discriminal (New_C, Empty);
9858 Set_Is_Completely_Hidden (New_C);
9860 -- Set the Original_Record_Component of each discriminant in the
9861 -- derived base to point to the corresponding girder that we just
9864 Discrim := First_Discriminant (Derived_Base);
9865 while Present (Discrim) loop
9866 Corr_Discrim := Corresponding_Discriminant (Discrim);
9868 -- Corr_Discrimm could be missing in an error situation.
9870 if Present (Corr_Discrim)
9871 and then Original_Record_Component (Corr_Discrim) = Old_C
9873 Set_Original_Record_Component (Discrim, New_C);
9876 Next_Discriminant (Discrim);
9879 Append_Entity (New_C, Derived_Base);
9882 if not Is_Tagged then
9883 Append_Elmt (Old_C, Assoc_List);
9884 Append_Elmt (New_C, Assoc_List);
9886 end Inherit_Component;
9888 -- Variables local to Inherit_Components.
9890 Loc : constant Source_Ptr := Sloc (N);
9892 Parent_Discrim : Entity_Id;
9893 Girder_Discrim : Entity_Id;
9896 Component : Entity_Id;
9898 -- Start of processing for Inherit_Components
9901 if not Is_Tagged then
9902 Append_Elmt (Parent_Base, Assoc_List);
9903 Append_Elmt (Derived_Base, Assoc_List);
9906 -- Inherit parent discriminants if needed.
9908 if Inherit_Discr then
9909 Parent_Discrim := First_Discriminant (Parent_Base);
9910 while Present (Parent_Discrim) loop
9911 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
9912 Next_Discriminant (Parent_Discrim);
9916 -- Create explicit girder discrims for untagged types when necessary.
9918 if not Has_Unknown_Discriminants (Derived_Base)
9919 and then Has_Discriminants (Parent_Base)
9920 and then not Is_Tagged
9923 or else First_Discriminant (Parent_Base) /=
9924 First_Girder_Discriminant (Parent_Base))
9926 Girder_Discrim := First_Girder_Discriminant (Parent_Base);
9927 while Present (Girder_Discrim) loop
9928 Inherit_Component (Girder_Discrim, Girder_Discrim => True);
9929 Next_Girder_Discriminant (Girder_Discrim);
9933 -- See if we can apply the second transformation for derived types, as
9934 -- explained in point 6. in the comments above Build_Derived_Record_Type
9935 -- This is achieved by appending Derived_Base discriminants into
9936 -- Discs, which has the side effect of returning a non empty Discs
9937 -- list to the caller of Inherit_Components, which is what we want.
9940 and then Is_Empty_Elmt_List (Discs)
9941 and then (not Is_Private_Type (Derived_Base)
9942 or Is_Generic_Type (Derived_Base))
9944 D := First_Discriminant (Derived_Base);
9945 while Present (D) loop
9946 Append_Elmt (New_Reference_To (D, Loc), Discs);
9947 Next_Discriminant (D);
9951 -- Finally, inherit non-discriminant components unless they are not
9952 -- visible because defined or inherited from the full view of the
9953 -- parent. Don't inherit the _parent field of the parent type.
9955 Component := First_Entity (Parent_Base);
9956 while Present (Component) loop
9957 if Ekind (Component) /= E_Component
9958 or else Chars (Component) = Name_uParent
9962 -- If the derived type is within the parent type's declarative
9963 -- region, then the components can still be inherited even though
9964 -- they aren't visible at this point. This can occur for cases
9965 -- such as within public child units where the components must
9966 -- become visible upon entering the child unit's private part.
9968 elsif not Is_Visible_Component (Component)
9969 and then not In_Open_Scopes (Scope (Parent_Base))
9973 elsif Ekind (Derived_Base) = E_Private_Type
9974 or else Ekind (Derived_Base) = E_Limited_Private_Type
9979 Inherit_Component (Component);
9982 Next_Entity (Component);
9985 -- For tagged derived types, inherited discriminants cannot be used in
9986 -- component declarations of the record extension part. To achieve this
9987 -- we mark the inherited discriminants as not visible.
9989 if Is_Tagged and then Inherit_Discr then
9990 D := First_Discriminant (Derived_Base);
9991 while Present (D) loop
9992 Set_Is_Immediately_Visible (D, False);
9993 Next_Discriminant (D);
9998 end Inherit_Components;
10000 ------------------------------
10001 -- Is_Valid_Constraint_Kind --
10002 ------------------------------
10004 function Is_Valid_Constraint_Kind
10005 (T_Kind : Type_Kind;
10006 Constraint_Kind : Node_Kind)
10012 when Enumeration_Kind |
10014 return Constraint_Kind = N_Range_Constraint;
10016 when Decimal_Fixed_Point_Kind =>
10018 Constraint_Kind = N_Digits_Constraint
10020 Constraint_Kind = N_Range_Constraint;
10022 when Ordinary_Fixed_Point_Kind =>
10024 Constraint_Kind = N_Delta_Constraint
10026 Constraint_Kind = N_Range_Constraint;
10030 Constraint_Kind = N_Digits_Constraint
10032 Constraint_Kind = N_Range_Constraint;
10039 E_Incomplete_Type |
10042 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
10045 return True; -- Error will be detected later.
10048 end Is_Valid_Constraint_Kind;
10050 --------------------------
10051 -- Is_Visible_Component --
10052 --------------------------
10054 function Is_Visible_Component (C : Entity_Id) return Boolean is
10055 Original_Comp : constant Entity_Id := Original_Record_Component (C);
10056 Original_Scope : Entity_Id;
10059 if No (Original_Comp) then
10061 -- Premature usage, or previous error
10066 Original_Scope := Scope (Original_Comp);
10069 -- This test only concern tagged types
10071 if not Is_Tagged_Type (Original_Scope) then
10074 -- If it is _Parent or _Tag, there is no visiblity issue
10076 elsif not Comes_From_Source (Original_Comp) then
10079 -- If we are in the body of an instantiation, the component is
10080 -- visible even when the parent type (possibly defined in an
10081 -- enclosing unit or in a parent unit) might not.
10083 elsif In_Instance_Body then
10086 -- Discriminants are always visible.
10088 elsif Ekind (Original_Comp) = E_Discriminant
10089 and then not Has_Unknown_Discriminants (Original_Scope)
10093 -- If the component has been declared in an ancestor which is
10094 -- currently a private type, then it is not visible. The same
10095 -- applies if the component's containing type is not in an
10096 -- open scope and the original component's enclosing type
10097 -- is a visible full type of a private type (which can occur
10098 -- in cases where an attempt is being made to reference a
10099 -- component in a sibling package that is inherited from
10100 -- a visible component of a type in an ancestor package;
10101 -- the component in the sibling package should not be
10102 -- visible even though the component it inherited from
10103 -- is visible). This does not apply however in the case
10104 -- where the scope of the type is a private child unit.
10105 -- The latter suppression of visibility is needed for cases
10106 -- that are tested in B730006.
10108 elsif (Ekind (Original_Comp) /= E_Discriminant
10109 or else Has_Unknown_Discriminants (Original_Scope))
10111 (Is_Private_Type (Original_Scope)
10113 (not Is_Private_Descendant (Scope (Base_Type (Scope (C))))
10114 and then not In_Open_Scopes (Scope (Base_Type (Scope (C))))
10115 and then Has_Private_Declaration (Original_Scope)))
10119 -- There is another weird way in which a component may be invisible
10120 -- when the private and the full view are not derived from the same
10121 -- ancestor. Here is an example :
10123 -- type A1 is tagged record F1 : integer; end record;
10124 -- type A2 is new A1 with record F2 : integer; end record;
10125 -- type T is new A1 with private;
10127 -- type T is new A2 with private;
10129 -- In this case, the full view of T inherits F1 and F2 but the
10130 -- private view inherits only F1
10134 Ancestor : Entity_Id := Scope (C);
10138 if Ancestor = Original_Scope then
10140 elsif Ancestor = Etype (Ancestor) then
10144 Ancestor := Etype (Ancestor);
10150 end Is_Visible_Component;
10152 --------------------------
10153 -- Make_Class_Wide_Type --
10154 --------------------------
10156 procedure Make_Class_Wide_Type (T : Entity_Id) is
10157 CW_Type : Entity_Id;
10159 Next_E : Entity_Id;
10162 -- The class wide type can have been defined by the partial view in
10163 -- which case everything is already done
10165 if Present (Class_Wide_Type (T)) then
10170 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
10172 -- Inherit root type characteristics
10174 CW_Name := Chars (CW_Type);
10175 Next_E := Next_Entity (CW_Type);
10176 Copy_Node (T, CW_Type);
10177 Set_Comes_From_Source (CW_Type, False);
10178 Set_Chars (CW_Type, CW_Name);
10179 Set_Parent (CW_Type, Parent (T));
10180 Set_Next_Entity (CW_Type, Next_E);
10181 Set_Has_Delayed_Freeze (CW_Type);
10183 -- Customize the class-wide type: It has no prim. op., it cannot be
10184 -- abstract and its Etype points back to the root type
10186 Set_Ekind (CW_Type, E_Class_Wide_Type);
10187 Set_Is_Tagged_Type (CW_Type, True);
10188 Set_Primitive_Operations (CW_Type, New_Elmt_List);
10189 Set_Is_Abstract (CW_Type, False);
10190 Set_Etype (CW_Type, T);
10191 Set_Is_Constrained (CW_Type, False);
10192 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
10193 Init_Size_Align (CW_Type);
10195 -- If this is the class_wide type of a constrained subtype, it does
10196 -- not have discriminants.
10198 Set_Has_Discriminants (CW_Type,
10199 Has_Discriminants (T) and then not Is_Constrained (T));
10201 Set_Has_Unknown_Discriminants (CW_Type, True);
10202 Set_Class_Wide_Type (T, CW_Type);
10203 Set_Equivalent_Type (CW_Type, Empty);
10205 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
10207 Set_Class_Wide_Type (CW_Type, CW_Type);
10209 end Make_Class_Wide_Type;
10215 procedure Make_Index
10217 Related_Nod : Node_Id;
10218 Related_Id : Entity_Id := Empty;
10219 Suffix_Index : Nat := 1)
10223 Def_Id : Entity_Id := Empty;
10224 Found : Boolean := False;
10227 -- For a discrete range used in a constrained array definition and
10228 -- defined by a range, an implicit conversion to the predefined type
10229 -- INTEGER is assumed if each bound is either a numeric literal, a named
10230 -- number, or an attribute, and the type of both bounds (prior to the
10231 -- implicit conversion) is the type universal_integer. Otherwise, both
10232 -- bounds must be of the same discrete type, other than universal
10233 -- integer; this type must be determinable independently of the
10234 -- context, but using the fact that the type must be discrete and that
10235 -- both bounds must have the same type.
10237 -- Character literals also have a universal type in the absence of
10238 -- of additional context, and are resolved to Standard_Character.
10240 if Nkind (I) = N_Range then
10242 -- The index is given by a range constraint. The bounds are known
10243 -- to be of a consistent type.
10245 if not Is_Overloaded (I) then
10248 -- If the bounds are universal, choose the specific predefined
10251 if T = Universal_Integer then
10252 T := Standard_Integer;
10254 elsif T = Any_Character then
10258 ("ambiguous character literals (could be Wide_Character)",
10262 T := Standard_Character;
10269 Ind : Interp_Index;
10273 Get_First_Interp (I, Ind, It);
10275 while Present (It.Typ) loop
10276 if Is_Discrete_Type (It.Typ) then
10279 and then not Covers (It.Typ, T)
10280 and then not Covers (T, It.Typ)
10282 Error_Msg_N ("ambiguous bounds in discrete range", I);
10290 Get_Next_Interp (Ind, It);
10293 if T = Any_Type then
10294 Error_Msg_N ("discrete type required for range", I);
10295 Set_Etype (I, Any_Type);
10298 elsif T = Universal_Integer then
10299 T := Standard_Integer;
10304 if not Is_Discrete_Type (T) then
10305 Error_Msg_N ("discrete type required for range", I);
10306 Set_Etype (I, Any_Type);
10311 Process_Range_Expr_In_Decl (R, T, Related_Nod);
10313 elsif Nkind (I) = N_Subtype_Indication then
10315 -- The index is given by a subtype with a range constraint.
10317 T := Base_Type (Entity (Subtype_Mark (I)));
10319 if not Is_Discrete_Type (T) then
10320 Error_Msg_N ("discrete type required for range", I);
10321 Set_Etype (I, Any_Type);
10325 R := Range_Expression (Constraint (I));
10328 Process_Range_Expr_In_Decl (R,
10329 Entity (Subtype_Mark (I)), Related_Nod);
10331 elsif Nkind (I) = N_Attribute_Reference then
10333 -- The parser guarantees that the attribute is a RANGE attribute
10335 -- Is order critical here (setting T before Resolve). If so,
10336 -- document why, if not use Analyze_And_Resolve and get T after???
10343 -- If none of the above, must be a subtype. We convert this to a
10344 -- range attribute reference because in the case of declared first
10345 -- named subtypes, the types in the range reference can be different
10346 -- from the type of the entity. A range attribute normalizes the
10347 -- reference and obtains the correct types for the bounds.
10349 -- This transformation is in the nature of an expansion, is only
10350 -- done if expansion is active. In particular, it is not done on
10351 -- formal generic types, because we need to retain the name of the
10352 -- original index for instantiation purposes.
10355 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
10356 Error_Msg_N ("invalid subtype mark in discrete range ", I);
10357 Set_Etype (I, Any_Integer);
10360 -- The type mark may be that of an incomplete type. It is only
10361 -- now that we can get the full view, previous analysis does
10362 -- not look specifically for a type mark.
10364 Set_Entity (I, Get_Full_View (Entity (I)));
10365 Set_Etype (I, Entity (I));
10366 Def_Id := Entity (I);
10368 if not Is_Discrete_Type (Def_Id) then
10369 Error_Msg_N ("discrete type required for index", I);
10370 Set_Etype (I, Any_Type);
10375 if Expander_Active then
10377 Make_Attribute_Reference (Sloc (I),
10378 Attribute_Name => Name_Range,
10379 Prefix => Relocate_Node (I)));
10381 -- The original was a subtype mark that does not freeze. This
10382 -- means that the rewritten version must not freeze either.
10384 Set_Must_Not_Freeze (I);
10385 Set_Must_Not_Freeze (Prefix (I));
10387 -- Is order critical??? if so, document why, if not
10388 -- use Analyze_And_Resolve
10396 -- Type is legal, nothing else to construct.
10401 if not Is_Discrete_Type (T) then
10402 Error_Msg_N ("discrete type required for range", I);
10403 Set_Etype (I, Any_Type);
10406 elsif T = Any_Type then
10407 Set_Etype (I, Any_Type);
10411 -- We will now create the appropriate Itype to describe the
10412 -- range, but first a check. If we originally had a subtype,
10413 -- then we just label the range with this subtype. Not only
10414 -- is there no need to construct a new subtype, but it is wrong
10415 -- to do so for two reasons:
10417 -- 1. A legality concern, if we have a subtype, it must not
10418 -- freeze, and the Itype would cause freezing incorrectly
10420 -- 2. An efficiency concern, if we created an Itype, it would
10421 -- not be recognized as the same type for the purposes of
10422 -- eliminating checks in some circumstances.
10424 -- We signal this case by setting the subtype entity in Def_Id.
10426 -- It would be nice to also do this optimization for the cases
10427 -- of X'Range and also the explicit range X'First .. X'Last,
10428 -- but that is not done yet (it is just an efficiency concern) ???
10430 if No (Def_Id) then
10433 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
10434 Set_Etype (Def_Id, Base_Type (T));
10436 if Is_Signed_Integer_Type (T) then
10437 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
10439 elsif Is_Modular_Integer_Type (T) then
10440 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
10443 Set_Ekind (Def_Id, E_Enumeration_Subtype);
10444 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
10447 Set_Size_Info (Def_Id, (T));
10448 Set_RM_Size (Def_Id, RM_Size (T));
10449 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10451 Set_Scalar_Range (Def_Id, R);
10452 Conditional_Delay (Def_Id, T);
10454 -- In the subtype indication case, if the immediate parent of the
10455 -- new subtype is non-static, then the subtype we create is non-
10456 -- static, even if its bounds are static.
10458 if Nkind (I) = N_Subtype_Indication
10459 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
10461 Set_Is_Non_Static_Subtype (Def_Id);
10465 -- Final step is to label the index with this constructed type
10467 Set_Etype (I, Def_Id);
10470 ------------------------------
10471 -- Modular_Type_Declaration --
10472 ------------------------------
10474 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10475 Mod_Expr : constant Node_Id := Expression (Def);
10478 procedure Set_Modular_Size (Bits : Int);
10479 -- Sets RM_Size to Bits, and Esize to normal word size above this
10481 procedure Set_Modular_Size (Bits : Int) is
10483 Set_RM_Size (T, UI_From_Int (Bits));
10488 elsif Bits <= 16 then
10489 Init_Esize (T, 16);
10491 elsif Bits <= 32 then
10492 Init_Esize (T, 32);
10495 Init_Esize (T, System_Max_Binary_Modulus_Power);
10497 end Set_Modular_Size;
10499 -- Start of processing for Modular_Type_Declaration
10502 Analyze_And_Resolve (Mod_Expr, Any_Integer);
10504 Set_Ekind (T, E_Modular_Integer_Type);
10505 Init_Alignment (T);
10506 Set_Is_Constrained (T);
10508 if not Is_OK_Static_Expression (Mod_Expr) then
10510 ("non-static expression used for modular type bound", Mod_Expr);
10511 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10513 M_Val := Expr_Value (Mod_Expr);
10517 Error_Msg_N ("modulus value must be positive", Mod_Expr);
10518 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10521 Set_Modulus (T, M_Val);
10523 -- Create bounds for the modular type based on the modulus given in
10524 -- the type declaration and then analyze and resolve those bounds.
10526 Set_Scalar_Range (T,
10527 Make_Range (Sloc (Mod_Expr),
10529 Make_Integer_Literal (Sloc (Mod_Expr), 0),
10531 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
10533 -- Properly analyze the literals for the range. We do this manually
10534 -- because we can't go calling Resolve, since we are resolving these
10535 -- bounds with the type, and this type is certainly not complete yet!
10537 Set_Etype (Low_Bound (Scalar_Range (T)), T);
10538 Set_Etype (High_Bound (Scalar_Range (T)), T);
10539 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
10540 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
10542 -- Loop through powers of two to find number of bits required
10544 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
10548 if M_Val = 2 ** Bits then
10549 Set_Modular_Size (Bits);
10554 elsif M_Val < 2 ** Bits then
10555 Set_Non_Binary_Modulus (T);
10557 if Bits > System_Max_Nonbinary_Modulus_Power then
10558 Error_Msg_Uint_1 :=
10559 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
10561 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
10562 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10566 -- In the non-binary case, set size as per RM 13.3(55).
10568 Set_Modular_Size (Bits);
10575 -- If we fall through, then the size exceed System.Max_Binary_Modulus
10576 -- so we just signal an error and set the maximum size.
10578 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
10579 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
10581 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10582 Init_Alignment (T);
10584 end Modular_Type_Declaration;
10586 -------------------------
10587 -- New_Binary_Operator --
10588 -------------------------
10590 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id) is
10591 Loc : constant Source_Ptr := Sloc (Typ);
10594 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
10595 -- Create abbreviated declaration for the formal of a predefined
10596 -- Operator 'Op' of type 'Typ'
10598 --------------------
10599 -- Make_Op_Formal --
10600 --------------------
10602 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
10603 Formal : Entity_Id;
10606 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
10607 Set_Etype (Formal, Typ);
10608 Set_Mechanism (Formal, Default_Mechanism);
10610 end Make_Op_Formal;
10612 -- Start of processing for New_Binary_Operator
10615 Op := Make_Defining_Operator_Symbol (Loc, Op_Name);
10617 Set_Ekind (Op, E_Operator);
10618 Set_Scope (Op, Current_Scope);
10619 Set_Etype (Op, Typ);
10620 Set_Homonym (Op, Get_Name_Entity_Id (Op_Name));
10621 Set_Is_Immediately_Visible (Op);
10622 Set_Is_Intrinsic_Subprogram (Op);
10623 Set_Has_Completion (Op);
10624 Append_Entity (Op, Current_Scope);
10626 Set_Name_Entity_Id (Op_Name, Op);
10628 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10629 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10631 end New_Binary_Operator;
10633 -------------------------------------------
10634 -- Ordinary_Fixed_Point_Type_Declaration --
10635 -------------------------------------------
10637 procedure Ordinary_Fixed_Point_Type_Declaration
10641 Loc : constant Source_Ptr := Sloc (Def);
10642 Delta_Expr : constant Node_Id := Delta_Expression (Def);
10643 RRS : constant Node_Id := Real_Range_Specification (Def);
10644 Implicit_Base : Entity_Id;
10651 Check_Restriction (No_Fixed_Point, Def);
10653 -- Create implicit base type
10656 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
10657 Set_Etype (Implicit_Base, Implicit_Base);
10659 -- Analyze and process delta expression
10661 Analyze_And_Resolve (Delta_Expr, Any_Real);
10663 Check_Delta_Expression (Delta_Expr);
10664 Delta_Val := Expr_Value_R (Delta_Expr);
10666 Set_Delta_Value (Implicit_Base, Delta_Val);
10668 -- Compute default small from given delta, which is the largest
10669 -- power of two that does not exceed the given delta value.
10672 Tmp : Ureal := Ureal_1;
10676 if Delta_Val < Ureal_1 then
10677 while Delta_Val < Tmp loop
10678 Tmp := Tmp / Ureal_2;
10679 Scale := Scale + 1;
10684 Tmp := Tmp * Ureal_2;
10685 exit when Tmp > Delta_Val;
10686 Scale := Scale - 1;
10690 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
10693 Set_Small_Value (Implicit_Base, Small_Val);
10695 -- If no range was given, set a dummy range
10697 if RRS <= Empty_Or_Error then
10698 Low_Val := -Small_Val;
10699 High_Val := Small_Val;
10701 -- Otherwise analyze and process given range
10705 Low : constant Node_Id := Low_Bound (RRS);
10706 High : constant Node_Id := High_Bound (RRS);
10709 Analyze_And_Resolve (Low, Any_Real);
10710 Analyze_And_Resolve (High, Any_Real);
10711 Check_Real_Bound (Low);
10712 Check_Real_Bound (High);
10714 -- Obtain and set the range
10716 Low_Val := Expr_Value_R (Low);
10717 High_Val := Expr_Value_R (High);
10719 if Low_Val > High_Val then
10720 Error_Msg_NE ("?fixed point type& has null range", Def, T);
10725 -- The range for both the implicit base and the declared first
10726 -- subtype cannot be set yet, so we use the special routine
10727 -- Set_Fixed_Range to set a temporary range in place. Note that
10728 -- the bounds of the base type will be widened to be symmetrical
10729 -- and to fill the available bits when the type is frozen.
10731 -- We could do this with all discrete types, and probably should, but
10732 -- we absolutely have to do it for fixed-point, since the end-points
10733 -- of the range and the size are determined by the small value, which
10734 -- could be reset before the freeze point.
10736 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
10737 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
10739 Init_Size_Align (Implicit_Base);
10741 -- Complete definition of first subtype
10743 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
10744 Set_Etype (T, Implicit_Base);
10745 Init_Size_Align (T);
10746 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
10747 Set_Small_Value (T, Small_Val);
10748 Set_Delta_Value (T, Delta_Val);
10749 Set_Is_Constrained (T);
10751 end Ordinary_Fixed_Point_Type_Declaration;
10753 ----------------------------------------
10754 -- Prepare_Private_Subtype_Completion --
10755 ----------------------------------------
10757 procedure Prepare_Private_Subtype_Completion
10759 Related_Nod : Node_Id)
10761 Id_B : constant Entity_Id := Base_Type (Id);
10762 Full_B : constant Entity_Id := Full_View (Id_B);
10766 if Present (Full_B) then
10768 -- The Base_Type is already completed, we can complete the
10769 -- subtype now. We have to create a new entity with the same name,
10770 -- Thus we can't use Create_Itype.
10771 -- This is messy, should be fixed ???
10773 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
10774 Set_Is_Itype (Full);
10775 Set_Associated_Node_For_Itype (Full, Related_Nod);
10776 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
10779 -- The parent subtype may be private, but the base might not, in some
10780 -- nested instances. In that case, the subtype does not need to be
10781 -- exchanged. It would still be nice to make private subtypes and their
10782 -- bases consistent at all times ???
10784 if Is_Private_Type (Id_B) then
10785 Append_Elmt (Id, Private_Dependents (Id_B));
10788 end Prepare_Private_Subtype_Completion;
10790 ---------------------------
10791 -- Process_Discriminants --
10792 ---------------------------
10794 procedure Process_Discriminants (N : Node_Id) is
10797 Discr_Number : Uint;
10798 Discr_Type : Entity_Id;
10799 Default_Present : Boolean := False;
10800 Default_Not_Present : Boolean := False;
10801 Elist : Elist_Id := New_Elmt_List;
10804 -- A composite type other than an array type can have discriminants.
10805 -- Discriminants of non-limited types must have a discrete type.
10806 -- On entry, the current scope is the composite type.
10808 -- The discriminants are initially entered into the scope of the type
10809 -- via Enter_Name with the default Ekind of E_Void to prevent premature
10810 -- use, as explained at the end of this procedure.
10812 Discr := First (Discriminant_Specifications (N));
10813 while Present (Discr) loop
10814 Enter_Name (Defining_Identifier (Discr));
10816 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
10817 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
10820 Find_Type (Discriminant_Type (Discr));
10821 Discr_Type := Etype (Discriminant_Type (Discr));
10823 if Error_Posted (Discriminant_Type (Discr)) then
10824 Discr_Type := Any_Type;
10828 if Is_Access_Type (Discr_Type) then
10829 Check_Access_Discriminant_Requires_Limited
10830 (Discr, Discriminant_Type (Discr));
10832 if Ada_83 and then Comes_From_Source (Discr) then
10834 ("(Ada 83) access discriminant not allowed", Discr);
10837 elsif not Is_Discrete_Type (Discr_Type) then
10838 Error_Msg_N ("discriminants must have a discrete or access type",
10839 Discriminant_Type (Discr));
10842 Set_Etype (Defining_Identifier (Discr), Discr_Type);
10844 -- If a discriminant specification includes the assignment compound
10845 -- delimiter followed by an expression, the expression is the default
10846 -- expression of the discriminant; the default expression must be of
10847 -- the type of the discriminant. (RM 3.7.1) Since this expression is
10848 -- a default expression, we do the special preanalysis, since this
10849 -- expression does not freeze (see "Handling of Default Expressions"
10850 -- in spec of package Sem).
10852 if Present (Expression (Discr)) then
10853 Analyze_Default_Expression (Expression (Discr), Discr_Type);
10855 if Nkind (N) = N_Formal_Type_Declaration then
10857 ("discriminant defaults not allowed for formal type",
10858 Expression (Discr));
10860 elsif Is_Tagged_Type (Current_Scope) then
10862 ("discriminants of tagged type cannot have defaults",
10863 Expression (Discr));
10866 Default_Present := True;
10867 Append_Elmt (Expression (Discr), Elist);
10869 -- Tag the defining identifiers for the discriminants with
10870 -- their corresponding default expressions from the tree.
10872 Set_Discriminant_Default_Value
10873 (Defining_Identifier (Discr), Expression (Discr));
10877 Default_Not_Present := True;
10883 -- An element list consisting of the default expressions of the
10884 -- discriminants is constructed in the above loop and used to set
10885 -- the Discriminant_Constraint attribute for the type. If an object
10886 -- is declared of this (record or task) type without any explicit
10887 -- discriminant constraint given, this element list will form the
10888 -- actual parameters for the corresponding initialization procedure
10891 Set_Discriminant_Constraint (Current_Scope, Elist);
10892 Set_Girder_Constraint (Current_Scope, No_Elist);
10894 -- Default expressions must be provided either for all or for none
10895 -- of the discriminants of a discriminant part. (RM 3.7.1)
10897 if Default_Present and then Default_Not_Present then
10899 ("incomplete specification of defaults for discriminants", N);
10902 -- The use of the name of a discriminant is not allowed in default
10903 -- expressions of a discriminant part if the specification of the
10904 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
10906 -- To detect this, the discriminant names are entered initially with an
10907 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
10908 -- attempt to use a void entity (for example in an expression that is
10909 -- type-checked) produces the error message: premature usage. Now after
10910 -- completing the semantic analysis of the discriminant part, we can set
10911 -- the Ekind of all the discriminants appropriately.
10913 Discr := First (Discriminant_Specifications (N));
10914 Discr_Number := Uint_1;
10916 while Present (Discr) loop
10917 Id := Defining_Identifier (Discr);
10918 Set_Ekind (Id, E_Discriminant);
10919 Init_Component_Location (Id);
10921 Set_Discriminant_Number (Id, Discr_Number);
10923 -- Make sure this is always set, even in illegal programs
10925 Set_Corresponding_Discriminant (Id, Empty);
10927 -- Initialize the Original_Record_Component to the entity itself.
10928 -- Inherit_Components will propagate the right value to
10929 -- discriminants in derived record types.
10931 Set_Original_Record_Component (Id, Id);
10933 -- Create the discriminal for the discriminant.
10935 Build_Discriminal (Id);
10938 Discr_Number := Discr_Number + 1;
10941 Set_Has_Discriminants (Current_Scope);
10942 end Process_Discriminants;
10944 -----------------------
10945 -- Process_Full_View --
10946 -----------------------
10948 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
10949 Priv_Parent : Entity_Id;
10950 Full_Parent : Entity_Id;
10951 Full_Indic : Node_Id;
10954 -- First some sanity checks that must be done after semantic
10955 -- decoration of the full view and thus cannot be placed with other
10956 -- similar checks in Find_Type_Name
10958 if not Is_Limited_Type (Priv_T)
10959 and then (Is_Limited_Type (Full_T)
10960 or else Is_Limited_Composite (Full_T))
10963 ("completion of nonlimited type cannot be limited", Full_T);
10965 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
10967 ("completion of nonabstract type cannot be abstract", Full_T);
10969 elsif Is_Tagged_Type (Priv_T)
10970 and then Is_Limited_Type (Priv_T)
10971 and then not Is_Limited_Type (Full_T)
10973 -- GNAT allow its own definition of Limited_Controlled to disobey
10974 -- this rule in order in ease the implementation. The next test is
10975 -- safe because Root_Controlled is defined in a private system child
10977 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
10978 Set_Is_Limited_Composite (Full_T);
10981 ("completion of limited tagged type must be limited", Full_T);
10984 elsif Is_Generic_Type (Priv_T) then
10985 Error_Msg_N ("generic type cannot have a completion", Full_T);
10988 if Is_Tagged_Type (Priv_T)
10989 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
10990 and then Is_Derived_Type (Full_T)
10992 Priv_Parent := Etype (Priv_T);
10994 -- The full view of a private extension may have been transformed
10995 -- into an unconstrained derived type declaration and a subtype
10996 -- declaration (see build_derived_record_type for details).
10998 if Nkind (N) = N_Subtype_Declaration then
10999 Full_Indic := Subtype_Indication (N);
11000 Full_Parent := Etype (Base_Type (Full_T));
11002 Full_Indic := Subtype_Indication (Type_Definition (N));
11003 Full_Parent := Etype (Full_T);
11006 -- Check that the parent type of the full type is a descendant of
11007 -- the ancestor subtype given in the private extension. If either
11008 -- entity has an Etype equal to Any_Type then we had some previous
11009 -- error situation [7.3(8)].
11011 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
11014 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
11016 ("parent of full type must descend from parent"
11017 & " of private extension", Full_Indic);
11019 -- Check the rules of 7.3(10): if the private extension inherits
11020 -- known discriminants, then the full type must also inherit those
11021 -- discriminants from the same (ancestor) type, and the parent
11022 -- subtype of the full type must be constrained if and only if
11023 -- the ancestor subtype of the private extension is constrained.
11025 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
11026 and then not Has_Unknown_Discriminants (Priv_T)
11027 and then Has_Discriminants (Base_Type (Priv_Parent))
11030 Priv_Indic : constant Node_Id :=
11031 Subtype_Indication (Parent (Priv_T));
11033 Priv_Constr : constant Boolean :=
11034 Is_Constrained (Priv_Parent)
11036 Nkind (Priv_Indic) = N_Subtype_Indication
11037 or else Is_Constrained (Entity (Priv_Indic));
11039 Full_Constr : constant Boolean :=
11040 Is_Constrained (Full_Parent)
11042 Nkind (Full_Indic) = N_Subtype_Indication
11043 or else Is_Constrained (Entity (Full_Indic));
11045 Priv_Discr : Entity_Id;
11046 Full_Discr : Entity_Id;
11049 Priv_Discr := First_Discriminant (Priv_Parent);
11050 Full_Discr := First_Discriminant (Full_Parent);
11052 while Present (Priv_Discr) and then Present (Full_Discr) loop
11053 if Original_Record_Component (Priv_Discr) =
11054 Original_Record_Component (Full_Discr)
11056 Corresponding_Discriminant (Priv_Discr) =
11057 Corresponding_Discriminant (Full_Discr)
11064 Next_Discriminant (Priv_Discr);
11065 Next_Discriminant (Full_Discr);
11068 if Present (Priv_Discr) or else Present (Full_Discr) then
11070 ("full view must inherit discriminants of the parent type"
11071 & " used in the private extension", Full_Indic);
11073 elsif Priv_Constr and then not Full_Constr then
11075 ("parent subtype of full type must be constrained",
11078 elsif Full_Constr and then not Priv_Constr then
11080 ("parent subtype of full type must be unconstrained",
11085 -- Check the rules of 7.3(12): if a partial view has neither known
11086 -- or unknown discriminants, then the full type declaration shall
11087 -- define a definite subtype.
11089 elsif not Has_Unknown_Discriminants (Priv_T)
11090 and then not Has_Discriminants (Priv_T)
11091 and then not Is_Constrained (Full_T)
11094 ("full view must define a constrained type if partial view"
11095 & " has no discriminants", Full_T);
11098 -- ??????? Do we implement the following properly ?????
11099 -- If the ancestor subtype of a private extension has constrained
11100 -- discriminants, then the parent subtype of the full view shall
11101 -- impose a statically matching constraint on those discriminants
11105 -- For untagged types, verify that a type without discriminants
11106 -- is not completed with an unconstrained type.
11108 if not Is_Indefinite_Subtype (Priv_T)
11109 and then Is_Indefinite_Subtype (Full_T)
11111 Error_Msg_N ("full view of type must be definite subtype", Full_T);
11115 -- Create a full declaration for all its subtypes recorded in
11116 -- Private_Dependents and swap them similarly to the base type.
11117 -- These are subtypes that have been define before the full
11118 -- declaration of the private type. We also swap the entry in
11119 -- Private_Dependents list so we can properly restore the
11120 -- private view on exit from the scope.
11123 Priv_Elmt : Elmt_Id;
11128 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
11129 while Present (Priv_Elmt) loop
11130 Priv := Node (Priv_Elmt);
11132 if Ekind (Priv) = E_Private_Subtype
11133 or else Ekind (Priv) = E_Limited_Private_Subtype
11134 or else Ekind (Priv) = E_Record_Subtype_With_Private
11136 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
11137 Set_Is_Itype (Full);
11138 Set_Parent (Full, Parent (Priv));
11139 Set_Associated_Node_For_Itype (Full, N);
11141 -- Now we need to complete the private subtype, but since the
11142 -- base type has already been swapped, we must also swap the
11143 -- subtypes (and thus, reverse the arguments in the call to
11144 -- Complete_Private_Subtype).
11146 Copy_And_Swap (Priv, Full);
11147 Complete_Private_Subtype (Full, Priv, Full_T, N);
11148 Replace_Elmt (Priv_Elmt, Full);
11151 Next_Elmt (Priv_Elmt);
11155 -- If the private view was tagged, copy the new Primitive
11156 -- operations from the private view to the full view.
11158 if Is_Tagged_Type (Full_T) then
11160 Priv_List : Elist_Id;
11161 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
11164 D_Type : Entity_Id;
11167 if Is_Tagged_Type (Priv_T) then
11168 Priv_List := Primitive_Operations (Priv_T);
11170 P1 := First_Elmt (Priv_List);
11171 while Present (P1) loop
11174 -- Transfer explicit primitives, not those inherited from
11175 -- parent of partial view, which will be re-inherited on
11178 if Comes_From_Source (Prim) then
11179 P2 := First_Elmt (Full_List);
11180 while Present (P2) and then Node (P2) /= Prim loop
11184 -- If not found, that is a new one
11187 Append_Elmt (Prim, Full_List);
11195 -- In this case the partial view is untagged, so here we
11196 -- locate all of the earlier primitives that need to be
11197 -- treated as dispatching (those that appear between the
11198 -- two views). Note that these additional operations must
11199 -- all be new operations (any earlier operations that
11200 -- override inherited operations of the full view will
11201 -- already have been inserted in the primitives list and
11202 -- marked as dispatching by Check_Operation_From_Private_View.
11203 -- Note that implicit "/=" operators are excluded from being
11204 -- added to the primitives list since they shouldn't be
11205 -- treated as dispatching (tagged "/=" is handled specially).
11207 Prim := Next_Entity (Full_T);
11208 while Present (Prim) and then Prim /= Priv_T loop
11209 if (Ekind (Prim) = E_Procedure
11210 or else Ekind (Prim) = E_Function)
11213 D_Type := Find_Dispatching_Type (Prim);
11216 and then (Chars (Prim) /= Name_Op_Ne
11217 or else Comes_From_Source (Prim))
11219 Check_Controlling_Formals (Full_T, Prim);
11221 if not Is_Dispatching_Operation (Prim) then
11222 Append_Elmt (Prim, Full_List);
11223 Set_Is_Dispatching_Operation (Prim, True);
11224 Set_DT_Position (Prim, No_Uint);
11227 elsif Is_Dispatching_Operation (Prim)
11228 and then D_Type /= Full_T
11231 -- Verify that it is not otherwise controlled by
11232 -- a formal or a return value ot type T.
11234 Check_Controlling_Formals (D_Type, Prim);
11238 Next_Entity (Prim);
11242 -- For the tagged case, the two views can share the same
11243 -- Primitive Operation list and the same class wide type.
11244 -- Update attributes of the class-wide type which depend on
11245 -- the full declaration.
11247 if Is_Tagged_Type (Priv_T) then
11248 Set_Primitive_Operations (Priv_T, Full_List);
11249 Set_Class_Wide_Type
11250 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
11252 -- Any other attributes should be propagated to C_W ???
11254 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
11259 end Process_Full_View;
11261 -----------------------------------
11262 -- Process_Incomplete_Dependents --
11263 -----------------------------------
11265 procedure Process_Incomplete_Dependents
11267 Full_T : Entity_Id;
11270 Inc_Elmt : Elmt_Id;
11271 Priv_Dep : Entity_Id;
11272 New_Subt : Entity_Id;
11274 Disc_Constraint : Elist_Id;
11277 if No (Private_Dependents (Inc_T)) then
11281 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
11283 -- Itypes that may be generated by the completion of an incomplete
11284 -- subtype are not used by the back-end and not attached to the tree.
11285 -- They are created only for constraint-checking purposes.
11288 while Present (Inc_Elmt) loop
11289 Priv_Dep := Node (Inc_Elmt);
11291 if Ekind (Priv_Dep) = E_Subprogram_Type then
11293 -- An Access_To_Subprogram type may have a return type or a
11294 -- parameter type that is incomplete. Replace with the full view.
11296 if Etype (Priv_Dep) = Inc_T then
11297 Set_Etype (Priv_Dep, Full_T);
11301 Formal : Entity_Id;
11304 Formal := First_Formal (Priv_Dep);
11306 while Present (Formal) loop
11308 if Etype (Formal) = Inc_T then
11309 Set_Etype (Formal, Full_T);
11312 Next_Formal (Formal);
11316 elsif Is_Overloadable (Priv_Dep) then
11318 if Is_Tagged_Type (Full_T) then
11320 -- Subprogram has an access parameter whose designated type
11321 -- was incomplete. Reexamine declaration now, because it may
11322 -- be a primitive operation of the full type.
11324 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
11325 Set_Is_Dispatching_Operation (Priv_Dep);
11326 Check_Controlling_Formals (Full_T, Priv_Dep);
11329 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
11331 -- Can happen during processing of a body before the completion
11332 -- of a TA type. Ignore, because spec is also on dependent list.
11336 -- Dependent is a subtype
11339 -- We build a new subtype indication using the full view of the
11340 -- incomplete parent. The discriminant constraints have been
11341 -- elaborated already at the point of the subtype declaration.
11343 New_Subt := Create_Itype (E_Void, N);
11345 if Has_Discriminants (Full_T) then
11346 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
11348 Disc_Constraint := No_Elist;
11351 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
11352 Set_Full_View (Priv_Dep, New_Subt);
11355 Next_Elmt (Inc_Elmt);
11358 end Process_Incomplete_Dependents;
11360 --------------------------------
11361 -- Process_Range_Expr_In_Decl --
11362 --------------------------------
11364 procedure Process_Range_Expr_In_Decl
11367 Related_Nod : Node_Id;
11368 Check_List : List_Id := Empty_List;
11369 R_Check_Off : Boolean := False)
11372 R_Checks : Check_Result;
11373 Type_Decl : Node_Id;
11374 Def_Id : Entity_Id;
11377 Analyze_And_Resolve (R, Base_Type (T));
11379 if Nkind (R) = N_Range then
11380 Lo := Low_Bound (R);
11381 Hi := High_Bound (R);
11383 -- If there were errors in the declaration, try and patch up some
11384 -- common mistakes in the bounds. The cases handled are literals
11385 -- which are Integer where the expected type is Real and vice versa.
11386 -- These corrections allow the compilation process to proceed further
11387 -- along since some basic assumptions of the format of the bounds
11390 if Etype (R) = Any_Type then
11392 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
11394 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
11396 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
11398 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
11400 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
11402 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
11404 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
11406 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
11413 -- If the bounds of the range have been mistakenly given as
11414 -- string literals (perhaps in place of character literals),
11415 -- then an error has already been reported, but we rewrite
11416 -- the string literal as a bound of the range's type to
11417 -- avoid blowups in later processing that looks at static
11420 if Nkind (Lo) = N_String_Literal then
11422 Make_Attribute_Reference (Sloc (Lo),
11423 Attribute_Name => Name_First,
11424 Prefix => New_Reference_To (T, Sloc (Lo))));
11425 Analyze_And_Resolve (Lo);
11428 if Nkind (Hi) = N_String_Literal then
11430 Make_Attribute_Reference (Sloc (Hi),
11431 Attribute_Name => Name_First,
11432 Prefix => New_Reference_To (T, Sloc (Hi))));
11433 Analyze_And_Resolve (Hi);
11436 -- If bounds aren't scalar at this point then exit, avoiding
11437 -- problems with further processing of the range in this procedure.
11439 if not Is_Scalar_Type (Etype (Lo)) then
11443 -- Resolve (actually Sem_Eval) has checked that the bounds are in
11444 -- then range of the base type. Here we check whether the bounds
11445 -- are in the range of the subtype itself. Note that if the bounds
11446 -- represent the null range the Constraint_Error exception should
11449 -- ??? The following code should be cleaned up as follows
11450 -- 1. The Is_Null_Range (Lo, Hi) test should disapper since it
11451 -- is done in the call to Range_Check (R, T); below
11452 -- 2. The use of R_Check_Off should be investigated and possibly
11453 -- removed, this would clean up things a bit.
11455 if Is_Null_Range (Lo, Hi) then
11459 -- We use a flag here instead of suppressing checks on the
11460 -- type because the type we check against isn't necessarily the
11461 -- place where we put the check.
11463 if not R_Check_Off then
11464 R_Checks := Range_Check (R, T);
11465 Type_Decl := Parent (R);
11467 -- Look up tree to find an appropriate insertion point.
11468 -- This seems really junk code, and very brittle, couldn't
11469 -- we just use an insert actions call of some kind ???
11471 while Present (Type_Decl) and then not
11472 (Nkind (Type_Decl) = N_Full_Type_Declaration
11474 Nkind (Type_Decl) = N_Subtype_Declaration
11476 Nkind (Type_Decl) = N_Loop_Statement
11478 Nkind (Type_Decl) = N_Task_Type_Declaration
11480 Nkind (Type_Decl) = N_Single_Task_Declaration
11482 Nkind (Type_Decl) = N_Protected_Type_Declaration
11484 Nkind (Type_Decl) = N_Single_Protected_Declaration)
11486 Type_Decl := Parent (Type_Decl);
11489 -- Why would Type_Decl not be present??? Without this test,
11490 -- short regression tests fail.
11492 if Present (Type_Decl) then
11493 if Nkind (Type_Decl) = N_Loop_Statement then
11495 Indic : Node_Id := Parent (R);
11497 while Present (Indic) and then not
11498 (Nkind (Indic) = N_Subtype_Indication)
11500 Indic := Parent (Indic);
11503 if Present (Indic) then
11504 Def_Id := Etype (Subtype_Mark (Indic));
11506 Insert_Range_Checks
11512 Do_Before => True);
11516 Def_Id := Defining_Identifier (Type_Decl);
11518 if (Ekind (Def_Id) = E_Record_Type
11519 and then Depends_On_Discriminant (R))
11521 (Ekind (Def_Id) = E_Protected_Type
11522 and then Has_Discriminants (Def_Id))
11524 Append_Range_Checks
11525 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
11528 Insert_Range_Checks
11529 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
11538 Get_Index_Bounds (R, Lo, Hi);
11540 if Expander_Active then
11541 Force_Evaluation (Lo);
11542 Force_Evaluation (Hi);
11545 end Process_Range_Expr_In_Decl;
11547 --------------------------------------
11548 -- Process_Real_Range_Specification --
11549 --------------------------------------
11551 procedure Process_Real_Range_Specification (Def : Node_Id) is
11552 Spec : constant Node_Id := Real_Range_Specification (Def);
11555 Err : Boolean := False;
11557 procedure Analyze_Bound (N : Node_Id);
11558 -- Analyze and check one bound
11560 procedure Analyze_Bound (N : Node_Id) is
11562 Analyze_And_Resolve (N, Any_Real);
11564 if not Is_OK_Static_Expression (N) then
11566 ("bound in real type definition is not static", N);
11572 if Present (Spec) then
11573 Lo := Low_Bound (Spec);
11574 Hi := High_Bound (Spec);
11575 Analyze_Bound (Lo);
11576 Analyze_Bound (Hi);
11578 -- If error, clear away junk range specification
11581 Set_Real_Range_Specification (Def, Empty);
11584 end Process_Real_Range_Specification;
11586 ---------------------
11587 -- Process_Subtype --
11588 ---------------------
11590 function Process_Subtype
11592 Related_Nod : Node_Id;
11593 Related_Id : Entity_Id := Empty;
11594 Suffix : Character := ' ')
11598 Def_Id : Entity_Id;
11599 Full_View_Id : Entity_Id;
11600 Subtype_Mark_Id : Entity_Id;
11601 N_Dynamic_Ityp : Node_Id := Empty;
11604 -- Case of constraint present, so that we have an N_Subtype_Indication
11605 -- node (this node is created only if constraints are present).
11607 if Nkind (S) = N_Subtype_Indication then
11608 Find_Type (Subtype_Mark (S));
11610 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
11612 (Nkind (Parent (S)) = N_Subtype_Declaration
11614 Is_Itype (Defining_Identifier (Parent (S))))
11616 Check_Incomplete (Subtype_Mark (S));
11620 Subtype_Mark_Id := Entity (Subtype_Mark (S));
11622 if Is_Unchecked_Union (Subtype_Mark_Id)
11623 and then Comes_From_Source (Related_Nod)
11626 ("cannot create subtype of Unchecked_Union", Related_Nod);
11629 -- Explicit subtype declaration case
11631 if Nkind (P) = N_Subtype_Declaration then
11632 Def_Id := Defining_Identifier (P);
11634 -- Explicit derived type definition case
11636 elsif Nkind (P) = N_Derived_Type_Definition then
11637 Def_Id := Defining_Identifier (Parent (P));
11639 -- Implicit case, the Def_Id must be created as an implicit type.
11640 -- The one exception arises in the case of concurrent types,
11641 -- array and access types, where other subsidiary implicit types
11642 -- may be created and must appear before the main implicit type.
11643 -- In these cases we leave Def_Id set to Empty as a signal that
11644 -- Create_Itype has not yet been called to create Def_Id.
11647 if Is_Array_Type (Subtype_Mark_Id)
11648 or else Is_Concurrent_Type (Subtype_Mark_Id)
11649 or else Is_Access_Type (Subtype_Mark_Id)
11653 -- For the other cases, we create a new unattached Itype,
11654 -- and set the indication to ensure it gets attached later.
11658 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11661 N_Dynamic_Ityp := Related_Nod;
11664 -- If the kind of constraint is invalid for this kind of type,
11665 -- then give an error, and then pretend no constraint was given.
11667 if not Is_Valid_Constraint_Kind
11668 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
11671 ("incorrect constraint for this kind of type", Constraint (S));
11673 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
11675 -- Make recursive call, having got rid of the bogus constraint
11677 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
11680 -- Remaining processing depends on type
11682 case Ekind (Subtype_Mark_Id) is
11684 when Access_Kind =>
11685 Constrain_Access (Def_Id, S, Related_Nod);
11688 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
11690 when Decimal_Fixed_Point_Kind =>
11691 Constrain_Decimal (Def_Id, S, N_Dynamic_Ityp);
11693 when Enumeration_Kind =>
11694 Constrain_Enumeration (Def_Id, S, N_Dynamic_Ityp);
11696 when Ordinary_Fixed_Point_Kind =>
11697 Constrain_Ordinary_Fixed (Def_Id, S, N_Dynamic_Ityp);
11700 Constrain_Float (Def_Id, S, N_Dynamic_Ityp);
11702 when Integer_Kind =>
11703 Constrain_Integer (Def_Id, S, N_Dynamic_Ityp);
11705 when E_Record_Type |
11708 E_Incomplete_Type =>
11709 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11711 when Private_Kind =>
11712 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11713 Set_Private_Dependents (Def_Id, New_Elmt_List);
11715 -- In case of an invalid constraint prevent further processing
11716 -- since the type constructed is missing expected fields.
11718 if Etype (Def_Id) = Any_Type then
11722 -- If the full view is that of a task with discriminants,
11723 -- we must constrain both the concurrent type and its
11724 -- corresponding record type. Otherwise we will just propagate
11725 -- the constraint to the full view, if available.
11727 if Present (Full_View (Subtype_Mark_Id))
11728 and then Has_Discriminants (Subtype_Mark_Id)
11729 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
11732 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11734 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
11735 Constrain_Concurrent (Full_View_Id, S,
11736 Related_Nod, Related_Id, Suffix);
11737 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
11738 Set_Full_View (Def_Id, Full_View_Id);
11741 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
11744 when Concurrent_Kind =>
11745 Constrain_Concurrent (Def_Id, S,
11746 Related_Nod, Related_Id, Suffix);
11749 Error_Msg_N ("invalid subtype mark in subtype indication", S);
11752 -- Size and Convention are always inherited from the base type
11754 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
11755 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
11759 -- Case of no constraints present
11763 Check_Incomplete (S);
11766 end Process_Subtype;
11768 -----------------------------
11769 -- Record_Type_Declaration --
11770 -----------------------------
11772 procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id) is
11773 Def : constant Node_Id := Type_Definition (N);
11774 Range_Checks_Suppressed_Flag : Boolean := False;
11776 Is_Tagged : Boolean;
11777 Tag_Comp : Entity_Id;
11780 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
11781 -- if it detected an error for declaration T. This arises in the case of
11782 -- private tagged types where the full view omits the word tagged.
11784 Is_Tagged := Tagged_Present (Def)
11785 or else (Errors_Detected > 0 and then Is_Tagged_Type (T));
11787 -- Records constitute a scope for the component declarations within.
11788 -- The scope is created prior to the processing of these declarations.
11789 -- Discriminants are processed first, so that they are visible when
11790 -- processing the other components. The Ekind of the record type itself
11791 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
11793 -- Enter record scope
11797 -- These flags must be initialized before calling Process_Discriminants
11798 -- because this routine makes use of them.
11800 Set_Is_Tagged_Type (T, Is_Tagged);
11801 Set_Is_Limited_Record (T, Limited_Present (Def));
11803 -- Type is abstract if full declaration carries keyword, or if
11804 -- previous partial view did.
11806 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
11808 Set_Ekind (T, E_Record_Type);
11810 Init_Size_Align (T);
11812 Set_Girder_Constraint (T, No_Elist);
11814 -- If an incomplete or private type declaration was already given for
11815 -- the type, then this scope already exists, and the discriminants have
11816 -- been declared within. We must verify that the full declaration
11817 -- matches the incomplete one.
11819 Check_Or_Process_Discriminants (N, T);
11821 Set_Is_Constrained (T, not Has_Discriminants (T));
11822 Set_Has_Delayed_Freeze (T, True);
11824 -- For tagged types add a manually analyzed component corresponding
11825 -- to the component _tag, the corresponding piece of tree will be
11826 -- expanded as part of the freezing actions if it is not a CPP_Class.
11829 -- Do not add the tag unless we are in expansion mode.
11831 if Expander_Active then
11832 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
11833 Enter_Name (Tag_Comp);
11835 Set_Is_Tag (Tag_Comp);
11836 Set_Ekind (Tag_Comp, E_Component);
11837 Set_Etype (Tag_Comp, RTE (RE_Tag));
11838 Set_DT_Entry_Count (Tag_Comp, No_Uint);
11839 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
11840 Init_Component_Location (Tag_Comp);
11843 Make_Class_Wide_Type (T);
11844 Set_Primitive_Operations (T, New_Elmt_List);
11847 -- We must suppress range checks when processing the components
11848 -- of a record in the presence of discriminants, since we don't
11849 -- want spurious checks to be generated during their analysis, but
11850 -- must reset the Suppress_Range_Checks flags after having procesed
11851 -- the record definition.
11853 if Has_Discriminants (T) and then not Suppress_Range_Checks (T) then
11854 Set_Suppress_Range_Checks (T, True);
11855 Range_Checks_Suppressed_Flag := True;
11858 Record_Type_Definition (Def, T);
11860 if Range_Checks_Suppressed_Flag then
11861 Set_Suppress_Range_Checks (T, False);
11862 Range_Checks_Suppressed_Flag := False;
11865 -- Exit from record scope
11868 end Record_Type_Declaration;
11870 ----------------------------
11871 -- Record_Type_Definition --
11872 ----------------------------
11874 procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id) is
11875 Component : Entity_Id;
11876 Ctrl_Components : Boolean := False;
11877 Final_Storage_Only : Boolean := not Is_Controlled (T);
11880 -- If the component list of a record type is defined by the reserved
11881 -- word null and there is no discriminant part, then the record type has
11882 -- no components and all records of the type are null records (RM 3.7)
11883 -- This procedure is also called to process the extension part of a
11884 -- record extension, in which case the current scope may have inherited
11888 or else No (Component_List (Def))
11889 or else Null_Present (Component_List (Def))
11894 Analyze_Declarations (Component_Items (Component_List (Def)));
11896 if Present (Variant_Part (Component_List (Def))) then
11897 Analyze (Variant_Part (Component_List (Def)));
11901 -- After completing the semantic analysis of the record definition,
11902 -- record components, both new and inherited, are accessible. Set
11903 -- their kind accordingly.
11905 Component := First_Entity (Current_Scope);
11906 while Present (Component) loop
11908 if Ekind (Component) = E_Void then
11909 Set_Ekind (Component, E_Component);
11910 Init_Component_Location (Component);
11913 if Has_Task (Etype (Component)) then
11917 if Ekind (Component) /= E_Component then
11920 elsif Has_Controlled_Component (Etype (Component))
11921 or else (Chars (Component) /= Name_uParent
11922 and then Is_Controlled (Etype (Component)))
11924 Set_Has_Controlled_Component (T, True);
11925 Final_Storage_Only := Final_Storage_Only
11926 and then Finalize_Storage_Only (Etype (Component));
11927 Ctrl_Components := True;
11930 Next_Entity (Component);
11933 -- A type is Finalize_Storage_Only only if all its controlled
11934 -- components are so.
11936 if Ctrl_Components then
11937 Set_Finalize_Storage_Only (T, Final_Storage_Only);
11940 if Present (Def) then
11941 Process_End_Label (Def, 'e');
11943 end Record_Type_Definition;
11945 ---------------------
11946 -- Set_Fixed_Range --
11947 ---------------------
11949 -- The range for fixed-point types is complicated by the fact that we
11950 -- do not know the exact end points at the time of the declaration. This
11951 -- is true for three reasons:
11953 -- A size clause may affect the fudging of the end-points
11954 -- A small clause may affect the values of the end-points
11955 -- We try to include the end-points if it does not affect the size
11957 -- This means that the actual end-points must be established at the
11958 -- point when the type is frozen. Meanwhile, we first narrow the range
11959 -- as permitted (so that it will fit if necessary in a small specified
11960 -- size), and then build a range subtree with these narrowed bounds.
11962 -- Set_Fixed_Range constructs the range from real literal values, and
11963 -- sets the range as the Scalar_Range of the given fixed-point type
11966 -- The parent of this range is set to point to the entity so that it
11967 -- is properly hooked into the tree (unlike normal Scalar_Range entries
11968 -- for other scalar types, which are just pointers to the range in the
11969 -- original tree, this would otherwise be an orphan).
11971 -- The tree is left unanalyzed. When the type is frozen, the processing
11972 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
11973 -- analyzed, and uses this as an indication that it should complete
11974 -- work on the range (it will know the final small and size values).
11976 procedure Set_Fixed_Range
11982 S : constant Node_Id :=
11984 Low_Bound => Make_Real_Literal (Loc, Lo),
11985 High_Bound => Make_Real_Literal (Loc, Hi));
11988 Set_Scalar_Range (E, S);
11990 end Set_Fixed_Range;
11992 --------------------------------------------------------
11993 -- Set_Girder_Constraint_From_Discriminant_Constraint --
11994 --------------------------------------------------------
11996 procedure Set_Girder_Constraint_From_Discriminant_Constraint
12000 -- Make sure set if encountered during
12001 -- Expand_To_Girder_Constraint
12003 Set_Girder_Constraint (E, No_Elist);
12005 -- Give it the right value
12007 if Is_Constrained (E) and then Has_Discriminants (E) then
12008 Set_Girder_Constraint (E,
12009 Expand_To_Girder_Constraint (E, Discriminant_Constraint (E)));
12012 end Set_Girder_Constraint_From_Discriminant_Constraint;
12014 ----------------------------------
12015 -- Set_Scalar_Range_For_Subtype --
12016 ----------------------------------
12018 procedure Set_Scalar_Range_For_Subtype
12019 (Def_Id : Entity_Id;
12022 Related_Nod : Node_Id)
12024 Kind : constant Entity_Kind := Ekind (Def_Id);
12026 Set_Scalar_Range (Def_Id, R);
12028 -- We need to link the range into the tree before resolving it so
12029 -- that types that are referenced, including importantly the subtype
12030 -- itself, are properly frozen (Freeze_Expression requires that the
12031 -- expression be properly linked into the tree). Of course if it is
12032 -- already linked in, then we do not disturb the current link.
12034 if No (Parent (R)) then
12035 Set_Parent (R, Def_Id);
12038 -- Reset the kind of the subtype during analysis of the range, to
12039 -- catch possible premature use in the bounds themselves.
12041 Set_Ekind (Def_Id, E_Void);
12042 Process_Range_Expr_In_Decl (R, Subt, Related_Nod);
12043 Set_Ekind (Def_Id, Kind);
12045 end Set_Scalar_Range_For_Subtype;
12047 -------------------------------------
12048 -- Signed_Integer_Type_Declaration --
12049 -------------------------------------
12051 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
12052 Implicit_Base : Entity_Id;
12053 Base_Typ : Entity_Id;
12056 Errs : Boolean := False;
12060 function Can_Derive_From (E : Entity_Id) return Boolean;
12061 -- Determine whether given bounds allow derivation from specified type
12063 procedure Check_Bound (Expr : Node_Id);
12064 -- Check bound to make sure it is integral and static. If not, post
12065 -- appropriate error message and set Errs flag
12067 function Can_Derive_From (E : Entity_Id) return Boolean is
12068 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
12069 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
12072 -- Note we check both bounds against both end values, to deal with
12073 -- strange types like ones with a range of 0 .. -12341234.
12075 return Lo <= Lo_Val and then Lo_Val <= Hi
12077 Lo <= Hi_Val and then Hi_Val <= Hi;
12078 end Can_Derive_From;
12080 procedure Check_Bound (Expr : Node_Id) is
12082 -- If a range constraint is used as an integer type definition, each
12083 -- bound of the range must be defined by a static expression of some
12084 -- integer type, but the two bounds need not have the same integer
12085 -- type (Negative bounds are allowed.) (RM 3.5.4)
12087 if not Is_Integer_Type (Etype (Expr)) then
12089 ("integer type definition bounds must be of integer type", Expr);
12092 elsif not Is_OK_Static_Expression (Expr) then
12094 ("non-static expression used for integer type bound", Expr);
12097 -- The bounds are folded into literals, and we set their type to be
12098 -- universal, to avoid typing difficulties: we cannot set the type
12099 -- of the literal to the new type, because this would be a forward
12100 -- reference for the back end, and if the original type is user-
12101 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
12104 if Is_Entity_Name (Expr) then
12105 Fold_Uint (Expr, Expr_Value (Expr));
12108 Set_Etype (Expr, Universal_Integer);
12112 -- Start of processing for Signed_Integer_Type_Declaration
12115 -- Create an anonymous base type
12118 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
12120 -- Analyze and check the bounds, they can be of any integer type
12122 Lo := Low_Bound (Def);
12123 Hi := High_Bound (Def);
12125 -- Arbitrarily use Integer as the type if either bound had an error
12127 if Hi = Error or else Lo = Error then
12128 Base_Typ := Any_Integer;
12129 Set_Error_Posted (T, True);
12131 -- Here both bounds are OK expressions
12134 Analyze_And_Resolve (Lo, Any_Integer);
12135 Analyze_And_Resolve (Hi, Any_Integer);
12141 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12142 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12145 -- Find type to derive from
12147 Lo_Val := Expr_Value (Lo);
12148 Hi_Val := Expr_Value (Hi);
12150 if Can_Derive_From (Standard_Short_Short_Integer) then
12151 Base_Typ := Base_Type (Standard_Short_Short_Integer);
12153 elsif Can_Derive_From (Standard_Short_Integer) then
12154 Base_Typ := Base_Type (Standard_Short_Integer);
12156 elsif Can_Derive_From (Standard_Integer) then
12157 Base_Typ := Base_Type (Standard_Integer);
12159 elsif Can_Derive_From (Standard_Long_Integer) then
12160 Base_Typ := Base_Type (Standard_Long_Integer);
12162 elsif Can_Derive_From (Standard_Long_Long_Integer) then
12163 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12166 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12167 Error_Msg_N ("integer type definition bounds out of range", Def);
12168 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12169 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12173 -- Complete both implicit base and declared first subtype entities
12175 Set_Etype (Implicit_Base, Base_Typ);
12176 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
12177 Set_Size_Info (Implicit_Base, (Base_Typ));
12178 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
12179 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
12181 Set_Ekind (T, E_Signed_Integer_Subtype);
12182 Set_Etype (T, Implicit_Base);
12184 Set_Size_Info (T, (Implicit_Base));
12185 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
12186 Set_Scalar_Range (T, Def);
12187 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
12188 Set_Is_Constrained (T);
12190 end Signed_Integer_Type_Declaration;
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