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));
3833 Set_Has_Unknown_Discriminants (Derived_Type,
3834 Has_Unknown_Discriminants (Parent_Type));
3836 if Is_Private_Type (Derived_Type) then
3837 Set_Private_Dependents (Derived_Type, New_Elmt_List);
3840 if Is_Private_Type (Parent_Type)
3841 and then Base_Type (Parent_Type) = Parent_Type
3842 and then In_Open_Scopes (Scope (Parent_Type))
3844 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
3846 if Is_Child_Unit (Scope (Current_Scope))
3847 and then Is_Completion
3848 and then In_Private_Part (Current_Scope)
3850 -- This is the unusual case where a type completed by a private
3851 -- derivation occurs within a package nested in a child unit,
3852 -- and the parent is declared in an ancestor. In this case, the
3853 -- full view of the parent type will become visible in the body
3854 -- of the enclosing child, and only then will the current type
3855 -- be possibly non-private. We build a underlying full view that
3856 -- will be installed when the enclosing child body is compiled.
3859 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
3863 Make_Defining_Identifier (Sloc (Derived_Type),
3864 Chars (Derived_Type));
3865 Set_Is_Itype (Full_Der);
3866 Set_Itype (IR, Full_Der);
3867 Insert_After (N, IR);
3869 -- The full view will be used to swap entities on entry/exit
3870 -- to the body, and must appear in the entity list for the
3873 Append_Entity (Full_Der, Scope (Derived_Type));
3874 Set_Has_Private_Declaration (Full_Der);
3875 Set_Has_Private_Declaration (Derived_Type);
3876 Set_Associated_Node_For_Itype (Full_Der, N);
3877 Set_Parent (Full_Der, Parent (Derived_Type));
3878 Full_P := Full_View (Parent_Type);
3879 Exchange_Declarations (Parent_Type);
3881 Exchange_Declarations (Full_P);
3882 Set_Underlying_Full_View (Derived_Type, Full_Der);
3886 end Build_Derived_Private_Type;
3888 -------------------------------
3889 -- Build_Derived_Record_Type --
3890 -------------------------------
3894 -- Ideally we would like to use the same model of type derivation for
3895 -- tagged and untagged record types. Unfortunately this is not quite
3896 -- possible because the semantics of representation clauses is different
3897 -- for tagged and untagged records under inheritance. Consider the
3900 -- type R (...) is [tagged] record ... end record;
3901 -- type T (...) is new R (...) [with ...];
3903 -- The representation clauses of T can specify a completely different
3904 -- record layout from R's. Hence a same component can be placed in two very
3905 -- different positions in objects of type T and R. If R and T are tagged
3906 -- types, representation clauses for T can only specify the layout of non
3907 -- inherited components, thus components that are common in R and T have
3908 -- the same position in objects of type R or T.
3910 -- This has two implications. The first is that the entire tree for R's
3911 -- declaration needs to be copied for T in the untagged case, so that
3912 -- T can be viewd as a record type of its own with its own derivation
3913 -- clauses. The second implication is the way we handle discriminants.
3914 -- Specifically, in the untagged case we need a way to communicate to Gigi
3915 -- what are the real discriminants in the record, while for the semantics
3916 -- we need to consider those introduced by the user to rename the
3917 -- discriminants in the parent type. This is handled by introducing the
3918 -- notion of girder discriminants. See below for more.
3920 -- Fortunately the way regular components are inherited can be handled in
3921 -- the same way in tagged and untagged types.
3923 -- To complicate things a bit more the private view of a private extension
3924 -- cannot be handled in the same way as the full view (for one thing the
3925 -- semantic rules are somewhat different). We will explain what differs
3928 -- 2. DISCRIMINANTS UNDER INHERITANCE.
3930 -- The semantic rules governing the discriminants of derived types are
3933 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
3934 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
3936 -- If parent type has discriminants, then the discriminants that are
3937 -- declared in the derived type are [3.4 (11)]:
3939 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
3942 -- o Otherwise, each discriminant of the parent type (implicitely
3943 -- declared in the same order with the same specifications). In this
3944 -- case, the discriminants are said to be "inherited", or if unknown in
3945 -- the parent are also unknown in the derived type.
3947 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
3949 -- o The parent subtype shall be constrained;
3951 -- o If the parent type is not a tagged type, then each discriminant of
3952 -- the derived type shall be used in the constraint defining a parent
3953 -- subtype [Implementation note: this ensures that the new discriminant
3954 -- can share storage with an existing discriminant.].
3956 -- For the derived type each discriminant of the parent type is either
3957 -- inherited, constrained to equal some new discriminant of the derived
3958 -- type, or constrained to the value of an expression.
3960 -- When inherited or constrained to equal some new discriminant, the
3961 -- parent discriminant and the discriminant of the derived type are said
3964 -- If a discriminant of the parent type is constrained to a specific value
3965 -- in the derived type definition, then the discriminant is said to be
3966 -- "specified" by that derived type definition.
3968 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
3970 -- We have spoken about girder discriminants in the point 1 (introduction)
3971 -- above. There are two sort of girder discriminants: implicit and
3972 -- explicit. As long as the derived type inherits the same discriminants as
3973 -- the root record type, girder discriminants are the same as regular
3974 -- discriminants, and are said to be implicit. However, if any discriminant
3975 -- in the root type was renamed in the derived type, then the derived
3976 -- type will contain explicit girder discriminants. Explicit girder
3977 -- discriminants are discriminants in addition to the semantically visible
3978 -- discriminants defined for the derived type. Girder discriminants are
3979 -- used by Gigi to figure out what are the physical discriminants in
3980 -- objects of the derived type (see precise definition in einfo.ads).
3981 -- As an example, consider the following:
3983 -- type R (D1, D2, D3 : Int) is record ... end record;
3984 -- type T1 is new R;
3985 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
3986 -- type T3 is new T2;
3987 -- type T4 (Y : Int) is new T3 (Y, 99);
3989 -- The following table summarizes the discriminants and girder
3990 -- discriminants in R and T1 through T4.
3992 -- Type Discrim Girder Discrim Comment
3993 -- R (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in R
3994 -- T1 (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in T1
3995 -- T2 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T2
3996 -- T3 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T3
3997 -- T4 (Y) (D1, D2, D3) Gider discrims are EXPLICIT in T4
3999 -- Field Corresponding_Discriminant (abbreviated CD below) allows to find
4000 -- the corresponding discriminant in the parent type, while
4001 -- Original_Record_Component (abbreviated ORC below), the actual physical
4002 -- component that is renamed. Finally the field Is_Completely_Hidden
4003 -- (abbreaviated ICH below) is set for all explicit girder discriminants
4004 -- (see einfo.ads for more info). For the above example this gives:
4006 -- Discrim CD ORC ICH
4007 -- ^^^^^^^ ^^ ^^^ ^^^
4008 -- D1 in R empty itself no
4009 -- D2 in R empty itself no
4010 -- D3 in R empty itself no
4012 -- D1 in T1 D1 in R itself no
4013 -- D2 in T1 D2 in R itself no
4014 -- D3 in T1 D3 in R itself no
4016 -- X1 in T2 D3 in T1 D3 in T2 no
4017 -- X2 in T2 D1 in T1 D1 in T2 no
4018 -- D1 in T2 empty itself yes
4019 -- D2 in T2 empty itself yes
4020 -- D3 in T2 empty itself yes
4022 -- X1 in T3 X1 in T2 D3 in T3 no
4023 -- X2 in T3 X2 in T2 D1 in T3 no
4024 -- D1 in T3 empty itself yes
4025 -- D2 in T3 empty itself yes
4026 -- D3 in T3 empty itself yes
4028 -- Y in T4 X1 in T3 D3 in T3 no
4029 -- D1 in T3 empty itself yes
4030 -- D2 in T3 empty itself yes
4031 -- D3 in T3 empty itself yes
4033 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
4035 -- Type derivation for tagged types is fairly straightforward. if no
4036 -- discriminants are specified by the derived type, these are inherited
4037 -- from the parent. No explicit girder discriminants are ever necessary.
4038 -- The only manipulation that is done to the tree is that of adding a
4039 -- _parent field with parent type and constrained to the same constraint
4040 -- specified for the parent in the derived type definition. For instance:
4042 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
4043 -- type T1 is new R with null record;
4044 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
4046 -- are changed into :
4048 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
4049 -- _parent : R (D1, D2, D3);
4052 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
4053 -- _parent : T1 (X2, 88, X1);
4056 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4057 -- ORC and ICH fields are:
4059 -- Discrim CD ORC ICH
4060 -- ^^^^^^^ ^^ ^^^ ^^^
4061 -- D1 in R empty itself no
4062 -- D2 in R empty itself no
4063 -- D3 in R empty itself no
4065 -- D1 in T1 D1 in R D1 in R no
4066 -- D2 in T1 D2 in R D2 in R no
4067 -- D3 in T1 D3 in R D3 in R no
4069 -- X1 in T2 D3 in T1 D3 in R no
4070 -- X2 in T2 D1 in T1 D1 in R no
4072 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
4074 -- Regardless of whether we dealing with a tagged or untagged type
4075 -- we will transform all derived type declarations of the form
4077 -- type T is new R (...) [with ...];
4079 -- subtype S is R (...);
4080 -- type T is new S [with ...];
4082 -- type BT is new R [with ...];
4083 -- subtype T is BT (...);
4085 -- That is, the base derived type is constrained only if it has no
4086 -- discriminants. The reason for doing this is that GNAT's semantic model
4087 -- assumes that a base type with discriminants is unconstrained.
4089 -- Note that, strictly speaking, the above transformation is not always
4090 -- correct. Consider for instance the following exercpt from ACVC b34011a:
4092 -- procedure B34011A is
4093 -- type REC (D : integer := 0) is record
4098 -- type T6 is new Rec;
4099 -- function F return T6;
4104 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4107 -- The definition of Q6.U is illegal. However transforming Q6.U into
4109 -- type BaseU is new T6;
4110 -- subtype U is BaseU (Q6.F.I)
4112 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4113 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4114 -- the transformation described above.
4116 -- There is another instance where the above transformation is incorrect.
4120 -- type Base (D : Integer) is tagged null record;
4121 -- procedure P (X : Base);
4123 -- type Der is new Base (2) with null record;
4124 -- procedure P (X : Der);
4127 -- Then the above transformation turns this into
4129 -- type Der_Base is new Base with null record;
4130 -- -- procedure P (X : Base) is implicitely inherited here
4131 -- -- as procedure P (X : Der_Base).
4133 -- subtype Der is Der_Base (2);
4134 -- procedure P (X : Der);
4135 -- -- The overriding of P (X : Der_Base) is illegal since we
4136 -- -- have a parameter conformance problem.
4138 -- To get around this problem, after having semantically processed Der_Base
4139 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4140 -- Discriminant_Constraint from Der so that when parameter conformance is
4141 -- checked when P is overridden, no sematic errors are flagged.
4143 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
4145 -- Regardless of the fact that we dealing with a tagged or untagged type
4146 -- we will transform all derived type declarations of the form
4148 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4149 -- type T is new R [with ...];
4151 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4153 -- The reason for such transformation is that it allows us to implement a
4154 -- very clean form of component inheritance as explained below.
4156 -- Note that this transformation is not achieved by direct tree rewriting
4157 -- and manipulation, but rather by redoing the semantic actions that the
4158 -- above transformation will entail. This is done directly in routine
4159 -- Inherit_Components.
4161 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
4163 -- In both tagged and untagged derived types, regular non discriminant
4164 -- components are inherited in the derived type from the parent type. In
4165 -- the absence of discriminants component, inheritance is straightforward
4166 -- as components can simply be copied from the parent.
4167 -- If the parent has discriminants, inheriting components constrained with
4168 -- these discriminants requires caution. Consider the following example:
4170 -- type R (D1, D2 : Positive) is [tagged] record
4171 -- S : String (D1 .. D2);
4174 -- type T1 is new R [with null record];
4175 -- type T2 (X : positive) is new R (1, X) [with null record];
4177 -- As explained in 6. above, T1 is rewritten as
4179 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4181 -- which makes the treatment for T1 and T2 identical.
4183 -- What we want when inheriting S, is that references to D1 and D2 in R are
4184 -- replaced with references to their correct constraints, ie D1 and D2 in
4185 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4186 -- with either discriminant references in the derived type or expressions.
4187 -- This replacement is acheived as follows: before inheriting R's
4188 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4189 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4190 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4191 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4192 -- by String (1 .. X).
4194 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
4196 -- We explain here the rules governing private type extensions relevant to
4197 -- type derivation. These rules are explained on the following example:
4199 -- type D [(...)] is new A [(...)] with private; <-- partial view
4200 -- type D [(...)] is new P [(...)] with null record; <-- full view
4202 -- Type A is called the ancestor subtype of the private extension.
4203 -- Type P is the parent type of the full view of the private extension. It
4204 -- must be A or a type derived from A.
4206 -- The rules concerning the discriminants of private type extensions are
4209 -- o If a private extension inherits known discriminants from the ancestor
4210 -- subtype, then the full view shall also inherit its discriminants from
4211 -- the ancestor subtype and the parent subtype of the full view shall be
4212 -- constrained if and only if the ancestor subtype is constrained.
4214 -- o If a partial view has unknown discriminants, then the full view may
4215 -- define a definite or an indefinite subtype, with or without
4218 -- o If a partial view has neither known nor unknown discriminants, then
4219 -- the full view shall define a definite subtype.
4221 -- o If the ancestor subtype of a private extension has constrained
4222 -- discrimiants, then the parent subtype of the full view shall impose a
4223 -- statically matching constraint on those discriminants.
4225 -- This means that only the following forms of private extensions are
4228 -- type D is new A with private; <-- partial view
4229 -- type D is new P with null record; <-- full view
4231 -- If A has no discriminants than P has no discriminants, otherwise P must
4232 -- inherit A's discriminants.
4234 -- type D is new A (...) with private; <-- partial view
4235 -- type D is new P (:::) with null record; <-- full view
4237 -- P must inherit A's discriminants and (...) and (:::) must statically
4240 -- subtype A is R (...);
4241 -- type D is new A with private; <-- partial view
4242 -- type D is new P with null record; <-- full view
4244 -- P must have inherited R's discriminants and must be derived from A or
4245 -- any of its subtypes.
4247 -- type D (..) is new A with private; <-- partial view
4248 -- type D (..) is new P [(:::)] with null record; <-- full view
4250 -- No specific constraints on P's discriminants or constraint (:::).
4251 -- Note that A can be unconstrained, but the parent subtype P must either
4252 -- be constrained or (:::) must be present.
4254 -- type D (..) is new A [(...)] with private; <-- partial view
4255 -- type D (..) is new P [(:::)] with null record; <-- full view
4257 -- P's constraints on A's discriminants must statically match those
4258 -- imposed by (...).
4260 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
4262 -- The full view of a private extension is handled exactly as described
4263 -- above. The model chose for the private view of a private extension
4264 -- is the same for what concerns discriminants (ie they receive the same
4265 -- treatment as in the tagged case). However, the private view of the
4266 -- private extension always inherits the components of the parent base,
4267 -- without replacing any discriminant reference. Strictly speacking this
4268 -- is incorrect. However, Gigi never uses this view to generate code so
4269 -- this is a purely semantic issue. In theory, a set of transformations
4270 -- similar to those given in 5. and 6. above could be applied to private
4271 -- views of private extensions to have the same model of component
4272 -- inheritance as for non private extensions. However, this is not done
4273 -- because it would further complicate private type processing.
4274 -- Semantically speaking, this leaves us in an uncomfortable
4275 -- situation. As an example consider:
4278 -- type R (D : integer) is tagged record
4279 -- S : String (1 .. D);
4281 -- procedure P (X : R);
4282 -- type T is new R (1) with private;
4284 -- type T is new R (1) with null record;
4287 -- This is transformed into:
4290 -- type R (D : integer) is tagged record
4291 -- S : String (1 .. D);
4293 -- procedure P (X : R);
4294 -- type T is new R (1) with private;
4296 -- type BaseT is new R with null record;
4297 -- subtype T is BaseT (1);
4300 -- (strictly speaking the above is incorrect Ada).
4302 -- From the semantic standpoint the private view of private extension T
4303 -- should be flagged as constrained since one can clearly have
4307 -- in a unit withing Pack. However, when deriving subprograms for the
4308 -- private view of private extension T, T must be seen as unconstrained
4309 -- since T has discriminants (this is a constraint of the current
4310 -- subprogram derivation model). Thus, when processing the private view of
4311 -- a private extension such as T, we first mark T as unconstrained, we
4312 -- process it, we perform program derivation and just before returning from
4313 -- Build_Derived_Record_Type we mark T as constrained.
4314 -- ??? Are there are other unconfortable cases that we will have to
4317 -- 10. RECORD_TYPE_WITH_PRIVATE complications.
4319 -- Types that are derived from a visible record type and have a private
4320 -- extension present other peculiarities. They behave mostly like private
4321 -- types, but if they have primitive operations defined, these will not
4322 -- have the proper signatures for further inheritance, because other
4323 -- primitive operations will use the implicit base that we define for
4324 -- private derivations below. This affect subprogram inheritance (see
4325 -- Derive_Subprograms for details). We also derive the implicit base from
4326 -- the base type of the full view, so that the implicit base is a record
4327 -- type and not another private type, This avoids infinite loops.
4329 procedure Build_Derived_Record_Type
4331 Parent_Type : Entity_Id;
4332 Derived_Type : Entity_Id;
4333 Derive_Subps : Boolean := True)
4335 Loc : constant Source_Ptr := Sloc (N);
4336 Parent_Base : Entity_Id;
4341 Discrim : Entity_Id;
4342 Last_Discrim : Entity_Id;
4344 Discs : Elist_Id := New_Elmt_List;
4345 -- An empty Discs list means that there were no constraints in the
4346 -- subtype indication or that there was an error processing it.
4348 Assoc_List : Elist_Id;
4349 New_Discrs : Elist_Id;
4351 New_Base : Entity_Id;
4353 New_Indic : Node_Id;
4355 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4356 Discriminant_Specs : constant Boolean
4357 := Present (Discriminant_Specifications (N));
4358 Private_Extension : constant Boolean
4359 := (Nkind (N) = N_Private_Extension_Declaration);
4361 Constraint_Present : Boolean;
4362 Inherit_Discrims : Boolean := False;
4364 Save_Etype : Entity_Id;
4365 Save_Discr_Constr : Elist_Id;
4366 Save_Next_Entity : Entity_Id;
4369 if Ekind (Parent_Type) = E_Record_Type_With_Private
4370 and then Present (Full_View (Parent_Type))
4371 and then Has_Discriminants (Parent_Type)
4373 Parent_Base := Base_Type (Full_View (Parent_Type));
4375 Parent_Base := Base_Type (Parent_Type);
4378 -- Before we start the previously documented transformations, here is
4379 -- a little fix for size and alignment of tagged types. Normally when
4380 -- we derive type D from type P, we copy the size and alignment of P
4381 -- as the default for D, and in the absence of explicit representation
4382 -- clauses for D, the size and alignment are indeed the same as the
4385 -- But this is wrong for tagged types, since fields may be added,
4386 -- and the default size may need to be larger, and the default
4387 -- alignment may need to be larger.
4389 -- We therefore reset the size and alignment fields in the tagged
4390 -- case. Note that the size and alignment will in any case be at
4391 -- least as large as the parent type (since the derived type has
4392 -- a copy of the parent type in the _parent field)
4395 Init_Size_Align (Derived_Type);
4398 -- STEP 0a: figure out what kind of derived type declaration we have.
4400 if Private_Extension then
4402 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4405 Type_Def := Type_Definition (N);
4407 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4408 -- Parent_Base can be a private type or private extension. However,
4409 -- for tagged types with an extension the newly added fields are
4410 -- visible and hence the Derived_Type is always an E_Record_Type.
4411 -- (except that the parent may have its own private fields).
4412 -- For untagged types we preserve the Ekind of the Parent_Base.
4414 if Present (Record_Extension_Part (Type_Def)) then
4415 Set_Ekind (Derived_Type, E_Record_Type);
4417 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4421 -- Indic can either be an N_Identifier if the subtype indication
4422 -- contains no constraint or an N_Subtype_Indication if the subtype
4423 -- indication has a constraint.
4425 Indic := Subtype_Indication (Type_Def);
4426 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
4428 if Constraint_Present then
4429 if not Has_Discriminants (Parent_Base) then
4431 ("invalid constraint: type has no discriminant",
4432 Constraint (Indic));
4434 Constraint_Present := False;
4435 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4437 elsif Is_Constrained (Parent_Type) then
4439 ("invalid constraint: parent type is already constrained",
4440 Constraint (Indic));
4442 Constraint_Present := False;
4443 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4447 -- STEP 0b: If needed, apply transformation given in point 5. above.
4449 if not Private_Extension
4450 and then Has_Discriminants (Parent_Type)
4451 and then not Discriminant_Specs
4452 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
4454 -- First, we must analyze the constraint (see comment in point 5.).
4456 if Constraint_Present then
4457 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
4459 if Has_Discriminants (Derived_Type)
4460 and then Has_Private_Declaration (Derived_Type)
4461 and then Present (Discriminant_Constraint (Derived_Type))
4463 -- Verify that constraints of the full view conform to those
4464 -- given in partial view.
4470 C1 := First_Elmt (New_Discrs);
4471 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
4473 while Present (C1) and then Present (C2) loop
4475 Fully_Conformant_Expressions (Node (C1), Node (C2))
4478 "constraint not conformant to previous declaration",
4488 -- Insert and analyze the declaration for the unconstrained base type
4490 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
4493 Make_Full_Type_Declaration (Loc,
4494 Defining_Identifier => New_Base,
4496 Make_Derived_Type_Definition (Loc,
4497 Abstract_Present => Abstract_Present (Type_Def),
4498 Subtype_Indication =>
4499 New_Occurrence_Of (Parent_Base, Loc),
4500 Record_Extension_Part =>
4501 Relocate_Node (Record_Extension_Part (Type_Def))));
4503 Set_Parent (New_Decl, Parent (N));
4504 Mark_Rewrite_Insertion (New_Decl);
4505 Insert_Before (N, New_Decl);
4507 -- Note that this call passes False for the Derive_Subps
4508 -- parameter because subprogram derivation is deferred until
4509 -- after creating the subtype (see below).
4512 (New_Decl, Parent_Base, New_Base,
4513 Is_Completion => True, Derive_Subps => False);
4515 -- ??? This needs re-examination to determine whether the
4516 -- above call can simply be replaced by a call to Analyze.
4518 Set_Analyzed (New_Decl);
4520 -- Insert and analyze the declaration for the constrained subtype
4522 if Constraint_Present then
4524 Make_Subtype_Indication (Loc,
4525 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4526 Constraint => Relocate_Node (Constraint (Indic)));
4531 Constr_List : List_Id := New_List;
4535 C := First_Elmt (Discriminant_Constraint (Parent_Type));
4536 while Present (C) loop
4539 -- It is safe here to call New_Copy_Tree since
4540 -- Force_Evaluation was called on each constraint in
4541 -- Build_Discriminant_Constraints.
4543 Append (New_Copy_Tree (Expr), To => Constr_List);
4549 Make_Subtype_Indication (Loc,
4550 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4552 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
4557 Make_Subtype_Declaration (Loc,
4558 Defining_Identifier => Derived_Type,
4559 Subtype_Indication => New_Indic));
4563 -- Derivation of subprograms must be delayed until the
4564 -- full subtype has been established to ensure proper
4565 -- overriding of subprograms inherited by full types.
4566 -- If the derivations occurred as part of the call to
4567 -- Build_Derived_Type above, then the check for type
4568 -- conformance would fail because earlier primitive
4569 -- subprograms could still refer to the full type prior
4570 -- the change to the new subtype and hence wouldn't
4571 -- match the new base type created here.
4573 Derive_Subprograms (Parent_Type, Derived_Type);
4575 -- For tagged types the Discriminant_Constraint of the new base itype
4576 -- is inherited from the first subtype so that no subtype conformance
4577 -- problem arise when the first subtype overrides primitive
4578 -- operations inherited by the implicit base type.
4581 Set_Discriminant_Constraint
4582 (New_Base, Discriminant_Constraint (Derived_Type));
4588 -- If we get here Derived_Type will have no discriminants or it will be
4589 -- a discriminated unconstrained base type.
4591 -- STEP 1a: perform preliminary actions/checks for derived tagged types
4594 -- The parent type is frozen for non-private extensions (RM 13.14(7))
4596 if not Private_Extension then
4597 Freeze_Before (N, Parent_Type);
4600 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
4601 and then not Is_Generic_Type (Derived_Type)
4603 if Is_Controlled (Parent_Type) then
4605 ("controlled type must be declared at the library level",
4609 ("type extension at deeper accessibility level than parent",
4615 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
4619 and then GB /= Enclosing_Generic_Body (Parent_Base)
4622 ("parent type must not be outside generic body",
4629 -- STEP 1b : preliminary cleanup of the full view of private types
4631 -- If the type is already marked as having discriminants, then it's the
4632 -- completion of a private type or private extension and we need to
4633 -- retain the discriminants from the partial view if the current
4634 -- declaration has Discriminant_Specifications so that we can verify
4635 -- conformance. However, we must remove any existing components that
4636 -- were inherited from the parent (and attached in Copy_Private_To_Full)
4637 -- because the full type inherits all appropriate components anyway, and
4638 -- we don't want the partial view's components interfering.
4640 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
4641 Discrim := First_Discriminant (Derived_Type);
4643 Last_Discrim := Discrim;
4644 Next_Discriminant (Discrim);
4645 exit when No (Discrim);
4648 Set_Last_Entity (Derived_Type, Last_Discrim);
4650 -- In all other cases wipe out the list of inherited components (even
4651 -- inherited discriminants), it will be properly rebuilt here.
4654 Set_First_Entity (Derived_Type, Empty);
4655 Set_Last_Entity (Derived_Type, Empty);
4658 -- STEP 1c: Initialize some flags for the Derived_Type
4660 -- The following flags must be initialized here so that
4661 -- Process_Discriminants can check that discriminants of tagged types
4662 -- do not have a default initial value and that access discriminants
4663 -- are only specified for limited records. For completeness, these
4664 -- flags are also initialized along with all the other flags below.
4666 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4667 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
4669 -- STEP 2a: process discriminants of derived type if any.
4671 New_Scope (Derived_Type);
4673 if Discriminant_Specs then
4674 Set_Has_Unknown_Discriminants (Derived_Type, False);
4676 -- The following call initializes fields Has_Discriminants and
4677 -- Discriminant_Constraint, unless we are processing the completion
4678 -- of a private type declaration.
4680 Check_Or_Process_Discriminants (N, Derived_Type);
4682 -- For non-tagged types the constraint on the Parent_Type must be
4683 -- present and is used to rename the discriminants.
4685 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
4686 Error_Msg_N ("untagged parent must have discriminants", Indic);
4688 elsif not Is_Tagged and then not Constraint_Present then
4690 ("discriminant constraint needed for derived untagged records",
4693 -- Otherwise the parent subtype must be constrained unless we have a
4694 -- private extension.
4696 elsif not Constraint_Present
4697 and then not Private_Extension
4698 and then not Is_Constrained (Parent_Type)
4701 ("unconstrained type not allowed in this context", Indic);
4703 elsif Constraint_Present then
4704 -- The following call sets the field Corresponding_Discriminant
4705 -- for the discriminants in the Derived_Type.
4707 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
4709 -- For untagged types all new discriminants must rename
4710 -- discriminants in the parent. For private extensions new
4711 -- discriminants cannot rename old ones (implied by [7.3(13)]).
4713 Discrim := First_Discriminant (Derived_Type);
4715 while Present (Discrim) loop
4717 and then not Present (Corresponding_Discriminant (Discrim))
4720 ("new discriminants must constrain old ones", Discrim);
4722 elsif Private_Extension
4723 and then Present (Corresponding_Discriminant (Discrim))
4726 ("Only static constraints allowed for parent"
4727 & " discriminants in the partial view", Indic);
4732 -- If a new discriminant is used in the constraint,
4733 -- then its subtype must be statically compatible
4734 -- with the parent discriminant's subtype (3.7(15)).
4736 if Present (Corresponding_Discriminant (Discrim))
4738 not Subtypes_Statically_Compatible
4740 Etype (Corresponding_Discriminant (Discrim)))
4743 ("subtype must be compatible with parent discriminant",
4747 Next_Discriminant (Discrim);
4751 -- STEP 2b: No new discriminants, inherit discriminants if any
4754 if Private_Extension then
4755 Set_Has_Unknown_Discriminants
4756 (Derived_Type, Has_Unknown_Discriminants (Parent_Type)
4757 or else Unknown_Discriminants_Present (N));
4759 Set_Has_Unknown_Discriminants
4760 (Derived_Type, Has_Unknown_Discriminants (Parent_Type));
4763 if not Has_Unknown_Discriminants (Derived_Type)
4764 and then Has_Discriminants (Parent_Type)
4766 Inherit_Discrims := True;
4767 Set_Has_Discriminants
4768 (Derived_Type, True);
4769 Set_Discriminant_Constraint
4770 (Derived_Type, Discriminant_Constraint (Parent_Base));
4773 -- The following test is true for private types (remember
4774 -- transformation 5. is not applied to those) and in an error
4777 if Constraint_Present then
4778 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
4781 -- For now mark a new derived type as cosntrained only if it has no
4782 -- discriminants. At the end of Build_Derived_Record_Type we properly
4783 -- set this flag in the case of private extensions. See comments in
4784 -- point 9. just before body of Build_Derived_Record_Type.
4788 not (Inherit_Discrims
4789 or else Has_Unknown_Discriminants (Derived_Type)));
4792 -- STEP 3: initialize fields of derived type.
4794 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4795 Set_Girder_Constraint (Derived_Type, No_Elist);
4797 -- Fields inherited from the Parent_Type
4800 (Derived_Type, Einfo.Discard_Names (Parent_Type));
4801 Set_Has_Specified_Layout
4802 (Derived_Type, Has_Specified_Layout (Parent_Type));
4803 Set_Is_Limited_Composite
4804 (Derived_Type, Is_Limited_Composite (Parent_Type));
4805 Set_Is_Limited_Record
4806 (Derived_Type, Is_Limited_Record (Parent_Type));
4807 Set_Is_Private_Composite
4808 (Derived_Type, Is_Private_Composite (Parent_Type));
4810 -- Fields inherited from the Parent_Base
4812 Set_Has_Controlled_Component
4813 (Derived_Type, Has_Controlled_Component (Parent_Base));
4814 Set_Has_Non_Standard_Rep
4815 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4816 Set_Has_Primitive_Operations
4817 (Derived_Type, Has_Primitive_Operations (Parent_Base));
4819 -- Direct controlled types do not inherit the Finalize_Storage_Only
4822 if not Is_Controlled (Parent_Type) then
4823 Set_Finalize_Storage_Only (Derived_Type,
4824 Finalize_Storage_Only (Parent_Type));
4827 -- Set fields for private derived types.
4829 if Is_Private_Type (Derived_Type) then
4830 Set_Depends_On_Private (Derived_Type, True);
4831 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4833 -- Inherit fields from non private record types. If this is the
4834 -- completion of a derivation from a private type, the parent itself
4835 -- is private, and the attributes come from its full view, which must
4839 if Is_Private_Type (Parent_Base)
4840 and then not Is_Record_Type (Parent_Base)
4842 Set_Component_Alignment
4843 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
4845 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
4847 Set_Component_Alignment
4848 (Derived_Type, Component_Alignment (Parent_Base));
4851 (Derived_Type, C_Pass_By_Copy (Parent_Base));
4855 -- Set fields for tagged types.
4858 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
4860 -- All tagged types defined in Ada.Finalization are controlled
4862 if Chars (Scope (Derived_Type)) = Name_Finalization
4863 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
4864 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
4866 Set_Is_Controlled (Derived_Type);
4868 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
4871 Make_Class_Wide_Type (Derived_Type);
4872 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
4874 if Has_Discriminants (Derived_Type)
4875 and then Constraint_Present
4877 Set_Girder_Constraint
4878 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4882 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
4883 Set_Has_Non_Standard_Rep
4884 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4887 -- STEP 4: Inherit components from the parent base and constrain them.
4888 -- Apply the second transformation described in point 6. above.
4890 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
4891 or else not Has_Discriminants (Parent_Type)
4892 or else not Is_Constrained (Parent_Type)
4896 Constrs := Discriminant_Constraint (Parent_Type);
4899 Assoc_List := Inherit_Components (N,
4900 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
4902 -- STEP 5a: Copy the parent record declaration for untagged types
4904 if not Is_Tagged then
4906 -- Discriminant_Constraint (Derived_Type) has been properly
4907 -- constructed. Save it and temporarily set it to Empty because we do
4908 -- not want the call to New_Copy_Tree below to mess this list.
4910 if Has_Discriminants (Derived_Type) then
4911 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
4912 Set_Discriminant_Constraint (Derived_Type, No_Elist);
4914 Save_Discr_Constr := No_Elist;
4917 -- Save the Etype field of Derived_Type. It is correctly set now, but
4918 -- the call to New_Copy tree may remap it to point to itself, which
4919 -- is not what we want. Ditto for the Next_Entity field.
4921 Save_Etype := Etype (Derived_Type);
4922 Save_Next_Entity := Next_Entity (Derived_Type);
4924 -- Assoc_List maps all girder discriminants in the Parent_Base to
4925 -- girder discriminants in the Derived_Type. It is fundamental that
4926 -- no types or itypes with discriminants other than the girder
4927 -- discriminants appear in the entities declared inside
4928 -- Derived_Type. Gigi won't like it.
4932 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
4934 -- Restore the fields saved prior to the New_Copy_Tree call
4935 -- and compute the girder constraint.
4937 Set_Etype (Derived_Type, Save_Etype);
4938 Set_Next_Entity (Derived_Type, Save_Next_Entity);
4940 if Has_Discriminants (Derived_Type) then
4941 Set_Discriminant_Constraint
4942 (Derived_Type, Save_Discr_Constr);
4943 Set_Girder_Constraint
4944 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4947 -- Insert the new derived type declaration
4949 Rewrite (N, New_Decl);
4951 -- STEP 5b: Complete the processing for record extensions in generics
4953 -- There is no completion for record extensions declared in the
4954 -- parameter part of a generic, so we need to complete processing for
4955 -- these generic record extensions here. The call to
4956 -- Record_Type_Definition will change the Ekind of the components
4957 -- from E_Void to E_Component.
4959 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
4960 Record_Type_Definition (Empty, Derived_Type);
4962 -- STEP 5c: Process the record extension for non private tagged types.
4964 elsif not Private_Extension then
4965 -- Add the _parent field in the derived type.
4967 Expand_Derived_Record (Derived_Type, Type_Def);
4969 -- Analyze the record extension
4971 Record_Type_Definition
4972 (Record_Extension_Part (Type_Def), Derived_Type);
4977 if Etype (Derived_Type) = Any_Type then
4981 -- Set delayed freeze and then derive subprograms, we need to do
4982 -- this in this order so that derived subprograms inherit the
4983 -- derived freeze if necessary.
4985 Set_Has_Delayed_Freeze (Derived_Type);
4986 if Derive_Subps then
4987 Derive_Subprograms (Parent_Type, Derived_Type);
4990 -- If we have a private extension which defines a constrained derived
4991 -- type mark as constrained here after we have derived subprograms. See
4992 -- comment on point 9. just above the body of Build_Derived_Record_Type.
4994 if Private_Extension and then Inherit_Discrims then
4995 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
4996 Set_Is_Constrained (Derived_Type, True);
4997 Set_Discriminant_Constraint (Derived_Type, Discs);
4999 elsif Is_Constrained (Parent_Type) then
5001 (Derived_Type, True);
5002 Set_Discriminant_Constraint
5003 (Derived_Type, Discriminant_Constraint (Parent_Type));
5007 end Build_Derived_Record_Type;
5009 ------------------------
5010 -- Build_Derived_Type --
5011 ------------------------
5013 procedure Build_Derived_Type
5015 Parent_Type : Entity_Id;
5016 Derived_Type : Entity_Id;
5017 Is_Completion : Boolean;
5018 Derive_Subps : Boolean := True)
5020 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5023 -- Set common attributes
5025 Set_Scope (Derived_Type, Current_Scope);
5027 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5028 Set_Etype (Derived_Type, Parent_Base);
5029 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
5031 Set_Size_Info (Derived_Type, Parent_Type);
5032 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5033 Set_Convention (Derived_Type, Convention (Parent_Type));
5034 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
5036 case Ekind (Parent_Type) is
5037 when Numeric_Kind =>
5038 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
5041 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
5045 | Class_Wide_Kind =>
5046 Build_Derived_Record_Type
5047 (N, Parent_Type, Derived_Type, Derive_Subps);
5050 when Enumeration_Kind =>
5051 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5054 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5056 when Incomplete_Or_Private_Kind =>
5057 Build_Derived_Private_Type
5058 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5060 -- For discriminated types, the derivation includes deriving
5061 -- primitive operations. For others it is done below.
5063 if Is_Tagged_Type (Parent_Type)
5064 or else Has_Discriminants (Parent_Type)
5065 or else (Present (Full_View (Parent_Type))
5066 and then Has_Discriminants (Full_View (Parent_Type)))
5071 when Concurrent_Kind =>
5072 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5075 raise Program_Error;
5078 if Etype (Derived_Type) = Any_Type then
5082 -- Set delayed freeze and then derive subprograms, we need to do
5083 -- this in this order so that derived subprograms inherit the
5084 -- derived freeze if necessary.
5086 Set_Has_Delayed_Freeze (Derived_Type);
5087 if Derive_Subps then
5088 Derive_Subprograms (Parent_Type, Derived_Type);
5091 Set_Has_Primitive_Operations
5092 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5093 end Build_Derived_Type;
5095 -----------------------
5096 -- Build_Discriminal --
5097 -----------------------
5099 procedure Build_Discriminal (Discrim : Entity_Id) is
5100 D_Minal : Entity_Id;
5101 CR_Disc : Entity_Id;
5104 -- A discriminal has the same names as the discriminant.
5106 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5108 Set_Ekind (D_Minal, E_In_Parameter);
5109 Set_Mechanism (D_Minal, Default_Mechanism);
5110 Set_Etype (D_Minal, Etype (Discrim));
5112 Set_Discriminal (Discrim, D_Minal);
5113 Set_Discriminal_Link (D_Minal, Discrim);
5115 -- For task types, build at once the discriminants of the corresponding
5116 -- record, which are needed if discriminants are used in entry defaults
5117 -- and in family bounds.
5119 if Is_Concurrent_Type (Current_Scope)
5120 or else Is_Limited_Type (Current_Scope)
5122 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5124 Set_Ekind (CR_Disc, E_In_Parameter);
5125 Set_Mechanism (CR_Disc, Default_Mechanism);
5126 Set_Etype (CR_Disc, Etype (Discrim));
5127 Set_CR_Discriminant (Discrim, CR_Disc);
5129 end Build_Discriminal;
5131 ------------------------------------
5132 -- Build_Discriminant_Constraints --
5133 ------------------------------------
5135 function Build_Discriminant_Constraints
5138 Derived_Def : Boolean := False)
5141 C : constant Node_Id := Constraint (Def);
5142 Nb_Discr : constant Nat := Number_Discriminants (T);
5143 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5144 -- Saves the expression corresponding to a given discriminant in T.
5146 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5147 -- Return the Position number within array Discr_Expr of a discriminant
5148 -- D within the discriminant list of the discriminated type T.
5154 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5158 Disc := First_Discriminant (T);
5159 for J in Discr_Expr'Range loop
5164 Next_Discriminant (Disc);
5167 -- Note: Since this function is called on discriminants that are
5168 -- known to belong to the discriminated type, falling through the
5169 -- loop with no match signals an internal compiler error.
5171 raise Program_Error;
5174 -- Variables local to Build_Discriminant_Constraints
5178 Elist : Elist_Id := New_Elmt_List;
5186 Discrim_Present : Boolean := False;
5188 -- Start of processing for Build_Discriminant_Constraints
5191 -- The following loop will process positional associations only.
5192 -- For a positional association, the (single) discriminant is
5193 -- implicitly specified by position, in textual order (RM 3.7.2).
5195 Discr := First_Discriminant (T);
5196 Constr := First (Constraints (C));
5198 for D in Discr_Expr'Range loop
5199 exit when Nkind (Constr) = N_Discriminant_Association;
5202 Error_Msg_N ("too few discriminants given in constraint", C);
5203 return New_Elmt_List;
5205 elsif Nkind (Constr) = N_Range
5206 or else (Nkind (Constr) = N_Attribute_Reference
5208 Attribute_Name (Constr) = Name_Range)
5211 ("a range is not a valid discriminant constraint", Constr);
5212 Discr_Expr (D) := Error;
5215 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5216 Discr_Expr (D) := Constr;
5219 Next_Discriminant (Discr);
5223 if No (Discr) and then Present (Constr) then
5224 Error_Msg_N ("too many discriminants given in constraint", Constr);
5225 return New_Elmt_List;
5228 -- Named associations can be given in any order, but if both positional
5229 -- and named associations are used in the same discriminant constraint,
5230 -- then positional associations must occur first, at their normal
5231 -- position. Hence once a named association is used, the rest of the
5232 -- discriminant constraint must use only named associations.
5234 while Present (Constr) loop
5236 -- Positional association forbidden after a named association.
5238 if Nkind (Constr) /= N_Discriminant_Association then
5239 Error_Msg_N ("positional association follows named one", Constr);
5240 return New_Elmt_List;
5242 -- Otherwise it is a named association
5245 -- E records the type of the discriminants in the named
5246 -- association. All the discriminants specified in the same name
5247 -- association must have the same type.
5251 -- Search the list of discriminants in T to see if the simple name
5252 -- given in the constraint matches any of them.
5254 Id := First (Selector_Names (Constr));
5255 while Present (Id) loop
5258 -- If Original_Discriminant is present, we are processing a
5259 -- generic instantiation and this is an instance node. We need
5260 -- to find the name of the corresponding discriminant in the
5261 -- actual record type T and not the name of the discriminant in
5262 -- the generic formal. Example:
5265 -- type G (D : int) is private;
5267 -- subtype W is G (D => 1);
5269 -- type Rec (X : int) is record ... end record;
5270 -- package Q is new P (G => Rec);
5272 -- At the point of the instantiation, formal type G is Rec
5273 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5274 -- which really looks like "subtype W is Rec (D => 1);" at
5275 -- the point of instantiation, we want to find the discriminant
5276 -- that corresponds to D in Rec, ie X.
5278 if Present (Original_Discriminant (Id)) then
5279 Discr := Find_Corresponding_Discriminant (Id, T);
5283 Discr := First_Discriminant (T);
5284 while Present (Discr) loop
5285 if Chars (Discr) = Chars (Id) then
5290 Next_Discriminant (Discr);
5294 Error_Msg_N ("& does not match any discriminant", Id);
5295 return New_Elmt_List;
5297 -- The following is only useful for the benefit of generic
5298 -- instances but it does not interfere with other
5299 -- processing for the non-generic case so we do it in all
5300 -- cases (for generics this statement is executed when
5301 -- processing the generic definition, see comment at the
5302 -- begining of this if statement).
5305 Set_Original_Discriminant (Id, Discr);
5309 Position := Pos_Of_Discr (T, Discr);
5311 if Present (Discr_Expr (Position)) then
5312 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5315 -- Each discriminant specified in the same named association
5316 -- must be associated with a separate copy of the
5317 -- corresponding expression.
5319 if Present (Next (Id)) then
5320 Expr := New_Copy_Tree (Expression (Constr));
5321 Set_Parent (Expr, Parent (Expression (Constr)));
5323 Expr := Expression (Constr);
5326 Discr_Expr (Position) := Expr;
5327 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
5330 -- A discriminant association with more than one discriminant
5331 -- name is only allowed if the named discriminants are all of
5332 -- the same type (RM 3.7.1(8)).
5335 E := Base_Type (Etype (Discr));
5337 elsif Base_Type (Etype (Discr)) /= E then
5339 ("all discriminants in an association " &
5340 "must have the same type", Id);
5350 -- A discriminant constraint must provide exactly one value for each
5351 -- discriminant of the type (RM 3.7.1(8)).
5353 for J in Discr_Expr'Range loop
5354 if No (Discr_Expr (J)) then
5355 Error_Msg_N ("too few discriminants given in constraint", C);
5356 return New_Elmt_List;
5360 -- Determine if there are discriminant expressions in the constraint.
5362 for J in Discr_Expr'Range loop
5363 if Denotes_Discriminant (Discr_Expr (J)) then
5364 Discrim_Present := True;
5368 -- Build an element list consisting of the expressions given in the
5369 -- discriminant constraint and apply the appropriate range
5370 -- checks. The list is constructed after resolving any named
5371 -- discriminant associations and therefore the expressions appear in
5372 -- the textual order of the discriminants.
5374 Discr := First_Discriminant (T);
5375 for J in Discr_Expr'Range loop
5376 if Discr_Expr (J) /= Error then
5378 Append_Elmt (Discr_Expr (J), Elist);
5380 -- If any of the discriminant constraints is given by a
5381 -- discriminant and we are in a derived type declaration we
5382 -- have a discriminant renaming. Establish link between new
5383 -- and old discriminant.
5385 if Denotes_Discriminant (Discr_Expr (J)) then
5387 Set_Corresponding_Discriminant
5388 (Entity (Discr_Expr (J)), Discr);
5391 -- Force the evaluation of non-discriminant expressions.
5392 -- If we have found a discriminant in the constraint 3.4(26)
5393 -- and 3.8(18) demand that no range checks are performed are
5394 -- after evaluation. In all other cases perform a range check.
5397 if not Discrim_Present then
5398 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
5401 Force_Evaluation (Discr_Expr (J));
5404 -- Check that the designated type of an access discriminant's
5405 -- expression is not a class-wide type unless the discriminant's
5406 -- designated type is also class-wide.
5408 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
5409 and then not Is_Class_Wide_Type
5410 (Designated_Type (Etype (Discr)))
5411 and then Etype (Discr_Expr (J)) /= Any_Type
5412 and then Is_Class_Wide_Type
5413 (Designated_Type (Etype (Discr_Expr (J))))
5415 Wrong_Type (Discr_Expr (J), Etype (Discr));
5419 Next_Discriminant (Discr);
5423 end Build_Discriminant_Constraints;
5425 ---------------------------------
5426 -- Build_Discriminated_Subtype --
5427 ---------------------------------
5429 procedure Build_Discriminated_Subtype
5433 Related_Nod : Node_Id;
5434 For_Access : Boolean := False)
5436 Has_Discrs : constant Boolean := Has_Discriminants (T);
5437 Constrained : constant Boolean
5438 := (Has_Discrs and then not Is_Empty_Elmt_List (Elist))
5439 or else Is_Constrained (T);
5442 if Ekind (T) = E_Record_Type then
5444 Set_Ekind (Def_Id, E_Private_Subtype);
5445 Set_Is_For_Access_Subtype (Def_Id, True);
5447 Set_Ekind (Def_Id, E_Record_Subtype);
5450 elsif Ekind (T) = E_Task_Type then
5451 Set_Ekind (Def_Id, E_Task_Subtype);
5453 elsif Ekind (T) = E_Protected_Type then
5454 Set_Ekind (Def_Id, E_Protected_Subtype);
5456 elsif Is_Private_Type (T) then
5457 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
5459 elsif Is_Class_Wide_Type (T) then
5460 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
5463 -- Incomplete type. Attach subtype to list of dependents, to be
5464 -- completed with full view of parent type.
5466 Set_Ekind (Def_Id, Ekind (T));
5467 Append_Elmt (Def_Id, Private_Dependents (T));
5470 Set_Etype (Def_Id, T);
5471 Init_Size_Align (Def_Id);
5472 Set_Has_Discriminants (Def_Id, Has_Discrs);
5473 Set_Is_Constrained (Def_Id, Constrained);
5475 Set_First_Entity (Def_Id, First_Entity (T));
5476 Set_Last_Entity (Def_Id, Last_Entity (T));
5477 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
5479 if Is_Tagged_Type (T) then
5480 Set_Is_Tagged_Type (Def_Id);
5481 Make_Class_Wide_Type (Def_Id);
5484 Set_Girder_Constraint (Def_Id, No_Elist);
5487 Set_Discriminant_Constraint (Def_Id, Elist);
5488 Set_Girder_Constraint_From_Discriminant_Constraint (Def_Id);
5491 if Is_Tagged_Type (T) then
5492 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
5493 Set_Is_Abstract (Def_Id, Is_Abstract (T));
5496 -- Subtypes introduced by component declarations do not need to be
5497 -- marked as delayed, and do not get freeze nodes, because the semantics
5498 -- verifies that the parents of the subtypes are frozen before the
5499 -- enclosing record is frozen.
5501 if not Is_Type (Scope (Def_Id)) then
5502 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
5504 if Is_Private_Type (T)
5505 and then Present (Full_View (T))
5507 Conditional_Delay (Def_Id, Full_View (T));
5509 Conditional_Delay (Def_Id, T);
5513 if Is_Record_Type (T) then
5514 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
5517 and then not Is_Empty_Elmt_List (Elist)
5518 and then not For_Access
5520 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
5521 elsif not For_Access then
5522 Set_Cloned_Subtype (Def_Id, T);
5526 end Build_Discriminated_Subtype;
5528 ------------------------
5529 -- Build_Scalar_Bound --
5530 ------------------------
5532 function Build_Scalar_Bound
5539 New_Bound : Entity_Id;
5542 -- Note: not clear why this is needed, how can the original bound
5543 -- be unanalyzed at this point? and if it is, what business do we
5544 -- have messing around with it? and why is the base type of the
5545 -- parent type the right type for the resolution. It probably is
5546 -- not! It is OK for the new bound we are creating, but not for
5547 -- the old one??? Still if it never happens, no problem!
5549 Analyze_And_Resolve (Bound, Base_Type (Par_T));
5551 if Nkind (Bound) = N_Integer_Literal
5552 or else Nkind (Bound) = N_Real_Literal
5554 New_Bound := New_Copy (Bound);
5555 Set_Etype (New_Bound, Der_T);
5556 Set_Analyzed (New_Bound);
5558 elsif Is_Entity_Name (Bound) then
5559 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
5561 -- The following is almost certainly wrong. What business do we have
5562 -- relocating a node (Bound) that is presumably still attached to
5563 -- the tree elsewhere???
5566 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
5569 Set_Etype (New_Bound, Der_T);
5571 end Build_Scalar_Bound;
5573 --------------------------------
5574 -- Build_Underlying_Full_View --
5575 --------------------------------
5577 procedure Build_Underlying_Full_View
5582 Loc : constant Source_Ptr := Sloc (N);
5583 Subt : constant Entity_Id :=
5584 Make_Defining_Identifier
5585 (Loc, New_External_Name (Chars (Typ), 'S'));
5593 if Nkind (N) = N_Full_Type_Declaration then
5594 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
5596 -- ??? ??? is this assert right, I assume so otherwise Constr
5597 -- would not be defined below (this used to be an elsif)
5599 else pragma Assert (Nkind (N) = N_Subtype_Declaration);
5600 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
5603 -- If the constraint has discriminant associations, the discriminant
5604 -- entity is already set, but it denotes a discriminant of the new
5605 -- type, not the original parent, so it must be found anew.
5607 C := First (Constraints (Constr));
5609 while Present (C) loop
5611 if Nkind (C) = N_Discriminant_Association then
5612 Id := First (Selector_Names (C));
5614 while Present (Id) loop
5615 Set_Original_Discriminant (Id, Empty);
5623 Indic := Make_Subtype_Declaration (Loc,
5624 Defining_Identifier => Subt,
5625 Subtype_Indication =>
5626 Make_Subtype_Indication (Loc,
5627 Subtype_Mark => New_Reference_To (Par, Loc),
5628 Constraint => New_Copy_Tree (Constr)));
5630 Insert_Before (N, Indic);
5632 Set_Underlying_Full_View (Typ, Full_View (Subt));
5633 end Build_Underlying_Full_View;
5635 -------------------------------
5636 -- Check_Abstract_Overriding --
5637 -------------------------------
5639 procedure Check_Abstract_Overriding (T : Entity_Id) is
5646 Op_List := Primitive_Operations (T);
5648 -- Loop to check primitive operations
5650 Elmt := First_Elmt (Op_List);
5651 while Present (Elmt) loop
5652 Subp := Node (Elmt);
5654 -- Special exception, do not complain about failure to
5655 -- override _Input and _Output, since we always provide
5656 -- automatic overridings for these subprograms.
5658 if Is_Abstract (Subp)
5659 and then Chars (Subp) /= Name_uInput
5660 and then Chars (Subp) /= Name_uOutput
5661 and then not Is_Abstract (T)
5663 if Present (Alias (Subp)) then
5664 -- Only perform the check for a derived subprogram when
5665 -- the type has an explicit record extension. This avoids
5666 -- incorrectly flagging abstract subprograms for the case
5667 -- of a type without an extension derived from a formal type
5668 -- with a tagged actual (can occur within a private part).
5670 Type_Def := Type_Definition (Parent (T));
5671 if Nkind (Type_Def) = N_Derived_Type_Definition
5672 and then Present (Record_Extension_Part (Type_Def))
5675 ("type must be declared abstract or & overridden",
5680 ("abstract subprogram not allowed for type&",
5683 ("nonabstract type has abstract subprogram&",
5690 end Check_Abstract_Overriding;
5692 ------------------------------------------------
5693 -- Check_Access_Discriminant_Requires_Limited --
5694 ------------------------------------------------
5696 procedure Check_Access_Discriminant_Requires_Limited
5701 -- A discriminant_specification for an access discriminant
5702 -- shall appear only in the declaration for a task or protected
5703 -- type, or for a type with the reserved word 'limited' in
5704 -- its definition or in one of its ancestors. (RM 3.7(10))
5706 if Nkind (Discriminant_Type (D)) = N_Access_Definition
5707 and then not Is_Concurrent_Type (Current_Scope)
5708 and then not Is_Concurrent_Record_Type (Current_Scope)
5709 and then not Is_Limited_Record (Current_Scope)
5710 and then Ekind (Current_Scope) /= E_Limited_Private_Type
5713 ("access discriminants allowed only for limited types", Loc);
5715 end Check_Access_Discriminant_Requires_Limited;
5717 -----------------------------------
5718 -- Check_Aliased_Component_Types --
5719 -----------------------------------
5721 procedure Check_Aliased_Component_Types (T : Entity_Id) is
5725 -- ??? Also need to check components of record extensions,
5726 -- but not components of protected types (which are always
5729 if not Is_Limited_Type (T) then
5730 if Ekind (T) = E_Record_Type then
5731 C := First_Component (T);
5732 while Present (C) loop
5734 and then Has_Discriminants (Etype (C))
5735 and then not Is_Constrained (Etype (C))
5736 and then not In_Instance
5739 ("aliased component must be constrained ('R'M 3.6(11))",
5746 elsif Ekind (T) = E_Array_Type then
5747 if Has_Aliased_Components (T)
5748 and then Has_Discriminants (Component_Type (T))
5749 and then not Is_Constrained (Component_Type (T))
5750 and then not In_Instance
5753 ("aliased component type must be constrained ('R'M 3.6(11))",
5758 end Check_Aliased_Component_Types;
5760 ----------------------
5761 -- Check_Completion --
5762 ----------------------
5764 procedure Check_Completion (Body_Id : Node_Id := Empty) is
5767 procedure Post_Error;
5768 -- Post error message for lack of completion for entity E
5770 procedure Post_Error is
5772 if not Comes_From_Source (E) then
5774 if (Ekind (E) = E_Task_Type
5775 or else Ekind (E) = E_Protected_Type)
5777 -- It may be an anonymous protected type created for a
5778 -- single variable. Post error on variable, if present.
5784 Var := First_Entity (Current_Scope);
5786 while Present (Var) loop
5787 exit when Etype (Var) = E
5788 and then Comes_From_Source (Var);
5793 if Present (Var) then
5800 -- If a generated entity has no completion, then either previous
5801 -- semantic errors have disabled the expansion phase, or else
5802 -- we had missing subunits, or else we are compiling without expan-
5803 -- sion, or else something is very wrong.
5805 if not Comes_From_Source (E) then
5807 (Errors_Detected > 0
5808 or else Subunits_Missing
5809 or else not Expander_Active);
5812 -- Here for source entity
5815 -- Here if no body to post the error message, so we post the error
5816 -- on the declaration that has no completion. This is not really
5817 -- the right place to post it, think about this later ???
5819 if No (Body_Id) then
5822 ("missing full declaration for }", Parent (E), E);
5825 ("missing body for &", Parent (E), E);
5828 -- Package body has no completion for a declaration that appears
5829 -- in the corresponding spec. Post error on the body, with a
5830 -- reference to the non-completed declaration.
5833 Error_Msg_Sloc := Sloc (E);
5837 ("missing full declaration for }!", Body_Id, E);
5839 elsif Is_Overloadable (E)
5840 and then Current_Entity_In_Scope (E) /= E
5842 -- It may be that the completion is mistyped and appears
5843 -- as a distinct overloading of the entity.
5846 Candidate : Entity_Id := Current_Entity_In_Scope (E);
5847 Decl : Node_Id := Unit_Declaration_Node (Candidate);
5850 if Is_Overloadable (Candidate)
5851 and then Ekind (Candidate) = Ekind (E)
5852 and then Nkind (Decl) = N_Subprogram_Body
5853 and then Acts_As_Spec (Decl)
5855 Check_Type_Conformant (Candidate, E);
5858 Error_Msg_NE ("missing body for & declared#!",
5863 Error_Msg_NE ("missing body for & declared#!",
5870 -- Start processing for Check_Completion
5873 E := First_Entity (Current_Scope);
5874 while Present (E) loop
5875 if Is_Intrinsic_Subprogram (E) then
5878 -- The following situation requires special handling: a child
5879 -- unit that appears in the context clause of the body of its
5882 -- procedure Parent.Child (...);
5884 -- with Parent.Child;
5885 -- package body Parent is
5887 -- Here Parent.Child appears as a local entity, but should not
5888 -- be flagged as requiring completion, because it is a
5889 -- compilation unit.
5891 elsif Ekind (E) = E_Function
5892 or else Ekind (E) = E_Procedure
5893 or else Ekind (E) = E_Generic_Function
5894 or else Ekind (E) = E_Generic_Procedure
5896 if not Has_Completion (E)
5897 and then not Is_Abstract (E)
5898 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5900 and then Chars (E) /= Name_uSize
5905 elsif Is_Entry (E) then
5906 if not Has_Completion (E) and then
5907 (Ekind (Scope (E)) = E_Protected_Object
5908 or else Ekind (Scope (E)) = E_Protected_Type)
5913 elsif Is_Package (E) then
5914 if Unit_Requires_Body (E) then
5915 if not Has_Completion (E)
5916 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5922 elsif not Is_Child_Unit (E) then
5923 May_Need_Implicit_Body (E);
5926 elsif Ekind (E) = E_Incomplete_Type
5927 and then No (Underlying_Type (E))
5931 elsif (Ekind (E) = E_Task_Type or else
5932 Ekind (E) = E_Protected_Type)
5933 and then not Has_Completion (E)
5937 elsif Ekind (E) = E_Constant
5938 and then Ekind (Etype (E)) = E_Task_Type
5939 and then not Has_Completion (Etype (E))
5943 elsif Ekind (E) = E_Protected_Object
5944 and then not Has_Completion (Etype (E))
5948 elsif Ekind (E) = E_Record_Type then
5949 if Is_Tagged_Type (E) then
5950 Check_Abstract_Overriding (E);
5953 Check_Aliased_Component_Types (E);
5955 elsif Ekind (E) = E_Array_Type then
5956 Check_Aliased_Component_Types (E);
5962 end Check_Completion;
5964 ----------------------------
5965 -- Check_Delta_Expression --
5966 ----------------------------
5968 procedure Check_Delta_Expression (E : Node_Id) is
5970 if not (Is_Real_Type (Etype (E))) then
5971 Wrong_Type (E, Any_Real);
5973 elsif not Is_OK_Static_Expression (E) then
5974 Error_Msg_N ("non-static expression used for delta value", E);
5976 elsif not UR_Is_Positive (Expr_Value_R (E)) then
5977 Error_Msg_N ("delta expression must be positive", E);
5983 -- If any of above errors occurred, then replace the incorrect
5984 -- expression by the real 0.1, which should prevent further errors.
5987 Make_Real_Literal (Sloc (E), Ureal_Tenth));
5988 Analyze_And_Resolve (E, Standard_Float);
5990 end Check_Delta_Expression;
5992 -----------------------------
5993 -- Check_Digits_Expression --
5994 -----------------------------
5996 procedure Check_Digits_Expression (E : Node_Id) is
5998 if not (Is_Integer_Type (Etype (E))) then
5999 Wrong_Type (E, Any_Integer);
6001 elsif not Is_OK_Static_Expression (E) then
6002 Error_Msg_N ("non-static expression used for digits value", E);
6004 elsif Expr_Value (E) <= 0 then
6005 Error_Msg_N ("digits value must be greater than zero", E);
6011 -- If any of above errors occurred, then replace the incorrect
6012 -- expression by the integer 1, which should prevent further errors.
6014 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
6015 Analyze_And_Resolve (E, Standard_Integer);
6017 end Check_Digits_Expression;
6019 ----------------------
6020 -- Check_Incomplete --
6021 ----------------------
6023 procedure Check_Incomplete (T : Entity_Id) is
6025 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
6026 Error_Msg_N ("invalid use of type before its full declaration", T);
6028 end Check_Incomplete;
6030 --------------------------
6031 -- Check_Initialization --
6032 --------------------------
6034 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
6036 if (Is_Limited_Type (T)
6037 or else Is_Limited_Composite (T))
6038 and then not In_Instance
6041 ("cannot initialize entities of limited type", Exp);
6043 end Check_Initialization;
6045 ------------------------------------
6046 -- Check_Or_Process_Discriminants --
6047 ------------------------------------
6049 -- If an incomplete or private type declaration was already given for
6050 -- the type, the discriminants may have already been processed if they
6051 -- were present on the incomplete declaration. In this case a full
6052 -- conformance check is performed otherwise just process them.
6054 procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id) is
6056 if Has_Discriminants (T) then
6058 -- Make the discriminants visible to component declarations.
6061 D : Entity_Id := First_Discriminant (T);
6065 while Present (D) loop
6066 Prev := Current_Entity (D);
6067 Set_Current_Entity (D);
6068 Set_Is_Immediately_Visible (D);
6069 Set_Homonym (D, Prev);
6071 -- This restriction gets applied to the full type here; it
6072 -- has already been applied earlier to the partial view
6074 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6076 Next_Discriminant (D);
6080 elsif Present (Discriminant_Specifications (N)) then
6081 Process_Discriminants (N);
6083 end Check_Or_Process_Discriminants;
6085 ----------------------
6086 -- Check_Real_Bound --
6087 ----------------------
6089 procedure Check_Real_Bound (Bound : Node_Id) is
6091 if not Is_Real_Type (Etype (Bound)) then
6093 ("bound in real type definition must be of real type", Bound);
6095 elsif not Is_OK_Static_Expression (Bound) then
6097 ("non-static expression used for real type bound", Bound);
6104 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6106 Resolve (Bound, Standard_Float);
6107 end Check_Real_Bound;
6109 ------------------------------
6110 -- Complete_Private_Subtype --
6111 ------------------------------
6113 procedure Complete_Private_Subtype
6116 Full_Base : Entity_Id;
6117 Related_Nod : Node_Id)
6119 Save_Next_Entity : Entity_Id;
6120 Save_Homonym : Entity_Id;
6123 -- Set semantic attributes for (implicit) private subtype completion.
6124 -- If the full type has no discriminants, then it is a copy of the full
6125 -- view of the base. Otherwise, it is a subtype of the base with a
6126 -- possible discriminant constraint. Save and restore the original
6127 -- Next_Entity field of full to ensure that the calls to Copy_Node
6128 -- do not corrupt the entity chain.
6130 -- Note that the type of the full view is the same entity as the
6131 -- type of the partial view. In this fashion, the subtype has
6132 -- access to the correct view of the parent.
6134 Save_Next_Entity := Next_Entity (Full);
6135 Save_Homonym := Homonym (Priv);
6137 case Ekind (Full_Base) is
6139 when E_Record_Type |
6145 Copy_Node (Priv, Full);
6147 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6148 Set_First_Entity (Full, First_Entity (Full_Base));
6149 Set_Last_Entity (Full, Last_Entity (Full_Base));
6152 Copy_Node (Full_Base, Full);
6153 Set_Chars (Full, Chars (Priv));
6154 Conditional_Delay (Full, Priv);
6155 Set_Sloc (Full, Sloc (Priv));
6159 Set_Next_Entity (Full, Save_Next_Entity);
6160 Set_Homonym (Full, Save_Homonym);
6161 Set_Associated_Node_For_Itype (Full, Related_Nod);
6163 -- Set common attributes for all subtypes.
6165 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6167 -- The Etype of the full view is inconsistent. Gigi needs to see the
6168 -- structural full view, which is what the current scheme gives:
6169 -- the Etype of the full view is the etype of the full base. However,
6170 -- if the full base is a derived type, the full view then looks like
6171 -- a subtype of the parent, not a subtype of the full base. If instead
6174 -- Set_Etype (Full, Full_Base);
6176 -- then we get inconsistencies in the front-end (confusion between
6177 -- views). Several outstanding bugs are related to this.
6179 Set_Is_First_Subtype (Full, False);
6180 Set_Scope (Full, Scope (Priv));
6181 Set_Size_Info (Full, Full_Base);
6182 Set_RM_Size (Full, RM_Size (Full_Base));
6183 Set_Is_Itype (Full);
6185 -- A subtype of a private-type-without-discriminants, whose full-view
6186 -- has discriminants with default expressions, is not constrained!
6188 if not Has_Discriminants (Priv) then
6189 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6192 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6193 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6195 -- Freeze the private subtype entity if its parent is delayed,
6196 -- and not already frozen. We skip this processing if the type
6197 -- is an anonymous subtype of a record component, or is the
6198 -- corresponding record of a protected type, since ???
6200 if not Is_Type (Scope (Full)) then
6201 Set_Has_Delayed_Freeze (Full,
6202 Has_Delayed_Freeze (Full_Base)
6203 and then (not Is_Frozen (Full_Base)));
6206 Set_Freeze_Node (Full, Empty);
6207 Set_Is_Frozen (Full, False);
6208 Set_Full_View (Priv, Full);
6210 if Has_Discriminants (Full) then
6211 Set_Girder_Constraint_From_Discriminant_Constraint (Full);
6212 Set_Girder_Constraint (Priv, Girder_Constraint (Full));
6213 if Has_Unknown_Discriminants (Full) then
6214 Set_Discriminant_Constraint (Full, No_Elist);
6218 if Ekind (Full_Base) = E_Record_Type
6219 and then Has_Discriminants (Full_Base)
6220 and then Has_Discriminants (Priv) -- might not, if errors
6221 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
6223 Create_Constrained_Components
6224 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
6226 -- If the full base is itself derived from private, build a congruent
6227 -- subtype of its underlying type, for use by the back end.
6229 elsif Ekind (Full_Base) in Private_Kind
6230 and then Is_Derived_Type (Full_Base)
6231 and then Has_Discriminants (Full_Base)
6233 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
6235 Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
6237 elsif Is_Record_Type (Full_Base) then
6239 -- Show Full is simply a renaming of Full_Base.
6241 Set_Cloned_Subtype (Full, Full_Base);
6244 -- It is usafe to share to bounds of a scalar type, because the
6245 -- Itype is elaborated on demand, and if a bound is non-static
6246 -- then different orders of elaboration in different units will
6247 -- lead to different external symbols.
6249 if Is_Scalar_Type (Full_Base) then
6250 Set_Scalar_Range (Full,
6251 Make_Range (Sloc (Related_Nod),
6252 Low_Bound => Duplicate_Subexpr (Type_Low_Bound (Full_Base)),
6253 High_Bound => Duplicate_Subexpr (Type_High_Bound (Full_Base))));
6256 -- ??? It seems that a lot of fields are missing that should be
6257 -- copied from Full_Base to Full. Here are some that are introduced
6258 -- in a non-disruptive way but a cleanup is necessary.
6260 if Is_Tagged_Type (Full_Base) then
6261 Set_Is_Tagged_Type (Full);
6262 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
6264 elsif Is_Concurrent_Type (Full_Base) then
6266 if Has_Discriminants (Full)
6267 and then Present (Corresponding_Record_Type (Full_Base))
6269 Set_Corresponding_Record_Type (Full,
6270 Constrain_Corresponding_Record
6271 (Full, Corresponding_Record_Type (Full_Base),
6272 Related_Nod, Full_Base));
6275 Set_Corresponding_Record_Type (Full,
6276 Corresponding_Record_Type (Full_Base));
6280 end Complete_Private_Subtype;
6282 ----------------------------
6283 -- Constant_Redeclaration --
6284 ----------------------------
6286 procedure Constant_Redeclaration
6291 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
6292 Obj_Def : constant Node_Id := Object_Definition (N);
6296 if Nkind (Parent (Prev)) = N_Object_Declaration then
6297 if Nkind (Object_Definition
6298 (Parent (Prev))) = N_Subtype_Indication
6300 -- Find type of new declaration. The constraints of the two
6301 -- views must match statically, but there is no point in
6302 -- creating an itype for the full view.
6304 if Nkind (Obj_Def) = N_Subtype_Indication then
6305 Find_Type (Subtype_Mark (Obj_Def));
6306 New_T := Entity (Subtype_Mark (Obj_Def));
6309 Find_Type (Obj_Def);
6310 New_T := Entity (Obj_Def);
6316 -- The full view may impose a constraint, even if the partial
6317 -- view does not, so construct the subtype.
6319 New_T := Find_Type_Of_Object (Obj_Def, N);
6324 -- Current declaration is illegal, diagnosed below in Enter_Name.
6330 -- If previous full declaration exists, or if a homograph is present,
6331 -- let Enter_Name handle it, either with an error, or with the removal
6332 -- of an overridden implicit subprogram.
6334 if Ekind (Prev) /= E_Constant
6335 or else Present (Expression (Parent (Prev)))
6339 -- Verify that types of both declarations match.
6341 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
6342 Error_Msg_Sloc := Sloc (Prev);
6343 Error_Msg_N ("type does not match declaration#", N);
6344 Set_Full_View (Prev, Id);
6345 Set_Etype (Id, Any_Type);
6347 -- If so, process the full constant declaration
6350 Set_Full_View (Prev, Id);
6351 Set_Is_Public (Id, Is_Public (Prev));
6352 Set_Is_Internal (Id);
6353 Append_Entity (Id, Current_Scope);
6355 -- Check ALIASED present if present before (RM 7.4(7))
6357 if Is_Aliased (Prev)
6358 and then not Aliased_Present (N)
6360 Error_Msg_Sloc := Sloc (Prev);
6361 Error_Msg_N ("ALIASED required (see declaration#)", N);
6364 -- Check that placement is in private part
6366 if Ekind (Current_Scope) = E_Package
6367 and then not In_Private_Part (Current_Scope)
6369 Error_Msg_Sloc := Sloc (Prev);
6370 Error_Msg_N ("full constant for declaration#"
6371 & " must be in private part", N);
6374 end Constant_Redeclaration;
6376 ----------------------
6377 -- Constrain_Access --
6378 ----------------------
6380 procedure Constrain_Access
6381 (Def_Id : in out Entity_Id;
6383 Related_Nod : Node_Id)
6385 T : constant Entity_Id := Entity (Subtype_Mark (S));
6386 Desig_Type : constant Entity_Id := Designated_Type (T);
6387 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
6388 Constraint_OK : Boolean := True;
6391 if Is_Array_Type (Desig_Type) then
6392 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
6394 elsif (Is_Record_Type (Desig_Type)
6395 or else Is_Incomplete_Or_Private_Type (Desig_Type))
6396 and then not Is_Constrained (Desig_Type)
6398 -- ??? The following code is a temporary kludge to ignore
6399 -- discriminant constraint on access type if
6400 -- it is constraining the current record. Avoid creating the
6401 -- implicit subtype of the record we are currently compiling
6402 -- since right now, we cannot handle these.
6403 -- For now, just return the access type itself.
6405 if Desig_Type = Current_Scope
6406 and then No (Def_Id)
6408 Set_Ekind (Desig_Subtype, E_Record_Subtype);
6409 Def_Id := Entity (Subtype_Mark (S));
6411 -- This call added to ensure that the constraint is
6412 -- analyzed (needed for a B test). Note that we
6413 -- still return early from this procedure to avoid
6414 -- recursive processing. ???
6416 Constrain_Discriminated_Type
6417 (Desig_Subtype, S, Related_Nod, For_Access => True);
6422 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
6423 For_Access => True);
6425 elsif (Is_Task_Type (Desig_Type)
6426 or else Is_Protected_Type (Desig_Type))
6427 and then not Is_Constrained (Desig_Type)
6429 Constrain_Concurrent
6430 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
6433 Error_Msg_N ("invalid constraint on access type", S);
6434 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
6435 Constraint_OK := False;
6439 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
6441 Set_Ekind (Def_Id, E_Access_Subtype);
6444 if Constraint_OK then
6445 Set_Etype (Def_Id, Base_Type (T));
6447 if Is_Private_Type (Desig_Type) then
6448 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
6451 Set_Etype (Def_Id, Any_Type);
6454 Set_Size_Info (Def_Id, T);
6455 Set_Is_Constrained (Def_Id, Constraint_OK);
6456 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
6457 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6458 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
6460 -- Itypes created for constrained record components do not receive
6461 -- a freeze node, they are elaborated when first seen.
6463 if not Is_Record_Type (Current_Scope) then
6464 Conditional_Delay (Def_Id, T);
6466 end Constrain_Access;
6468 ---------------------
6469 -- Constrain_Array --
6470 ---------------------
6472 procedure Constrain_Array
6473 (Def_Id : in out Entity_Id;
6475 Related_Nod : Node_Id;
6476 Related_Id : Entity_Id;
6479 C : constant Node_Id := Constraint (SI);
6480 Number_Of_Constraints : Nat := 0;
6483 Constraint_OK : Boolean := True;
6486 T := Entity (Subtype_Mark (SI));
6488 if Ekind (T) in Access_Kind then
6489 T := Designated_Type (T);
6492 -- If an index constraint follows a subtype mark in a subtype indication
6493 -- then the type or subtype denoted by the subtype mark must not already
6494 -- impose an index constraint. The subtype mark must denote either an
6495 -- unconstrained array type or an access type whose designated type
6496 -- is such an array type... (RM 3.6.1)
6498 if Is_Constrained (T) then
6500 ("array type is already constrained", Subtype_Mark (SI));
6501 Constraint_OK := False;
6504 S := First (Constraints (C));
6506 while Present (S) loop
6507 Number_Of_Constraints := Number_Of_Constraints + 1;
6511 -- In either case, the index constraint must provide a discrete
6512 -- range for each index of the array type and the type of each
6513 -- discrete range must be the same as that of the corresponding
6514 -- index. (RM 3.6.1)
6516 if Number_Of_Constraints /= Number_Dimensions (T) then
6517 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
6518 Constraint_OK := False;
6521 S := First (Constraints (C));
6522 Index := First_Index (T);
6525 -- Apply constraints to each index type
6527 for J in 1 .. Number_Of_Constraints loop
6528 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
6538 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
6540 Set_Ekind (Def_Id, E_Array_Subtype);
6543 Set_Size_Info (Def_Id, (T));
6544 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6545 Set_Etype (Def_Id, Base_Type (T));
6547 if Constraint_OK then
6548 Set_First_Index (Def_Id, First (Constraints (C)));
6551 Set_Component_Type (Def_Id, Component_Type (T));
6552 Set_Is_Constrained (Def_Id, True);
6553 Set_Is_Aliased (Def_Id, Is_Aliased (T));
6554 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6556 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
6557 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
6559 -- If the subtype is not that of a record component, build a freeze
6560 -- node if parent still needs one.
6562 -- If the subtype is not that of a record component, make sure
6563 -- that the Depends_On_Private status is set (explanation ???)
6564 -- and also that a conditional delay is set.
6566 if not Is_Type (Scope (Def_Id)) then
6567 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6568 Conditional_Delay (Def_Id, T);
6571 end Constrain_Array;
6573 ------------------------------
6574 -- Constrain_Component_Type --
6575 ------------------------------
6577 function Constrain_Component_Type
6578 (Compon_Type : Entity_Id;
6579 Constrained_Typ : Entity_Id;
6580 Related_Node : Node_Id;
6582 Constraints : Elist_Id)
6585 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
6587 function Build_Constrained_Array_Type
6588 (Old_Type : Entity_Id)
6590 -- If Old_Type is an array type, one of whose indices is
6591 -- constrained by a discriminant, build an Itype whose constraint
6592 -- replaces the discriminant with its value in the constraint.
6594 function Build_Constrained_Discriminated_Type
6595 (Old_Type : Entity_Id)
6597 -- Ditto for record components.
6599 function Build_Constrained_Access_Type
6600 (Old_Type : Entity_Id)
6602 -- Ditto for access types. Makes use of previous two functions, to
6603 -- constrain designated type.
6605 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
6606 -- T is an array or discriminated type, C is a list of constraints
6607 -- that apply to T. This routine builds the constrained subtype.
6609 function Is_Discriminant (Expr : Node_Id) return Boolean;
6610 -- Returns True if Expr is a discriminant.
6612 function Get_Value (Discrim : Entity_Id) return Node_Id;
6613 -- Find the value of discriminant Discrim in Constraint.
6615 -----------------------------------
6616 -- Build_Constrained_Access_Type --
6617 -----------------------------------
6619 function Build_Constrained_Access_Type
6620 (Old_Type : Entity_Id)
6623 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
6625 Desig_Subtype : Entity_Id;
6629 -- if the original access type was not embedded in the enclosing
6630 -- type definition, there is no need to produce a new access
6631 -- subtype. In fact every access type with an explicit constraint
6632 -- generates an itype whose scope is the enclosing record.
6634 if not Is_Type (Scope (Old_Type)) then
6637 elsif Is_Array_Type (Desig_Type) then
6638 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
6640 elsif Has_Discriminants (Desig_Type) then
6642 -- This may be an access type to an enclosing record type for
6643 -- which we are constructing the constrained components. Return
6644 -- the enclosing record subtype. This is not always correct,
6645 -- but avoids infinite recursion. ???
6647 Desig_Subtype := Any_Type;
6649 for J in reverse 0 .. Scope_Stack.Last loop
6650 Scop := Scope_Stack.Table (J).Entity;
6653 and then Base_Type (Scop) = Base_Type (Desig_Type)
6655 Desig_Subtype := Scop;
6658 exit when not Is_Type (Scop);
6661 if Desig_Subtype = Any_Type then
6663 Build_Constrained_Discriminated_Type (Desig_Type);
6670 if Desig_Subtype /= Desig_Type then
6671 -- The Related_Node better be here or else we won't be able
6672 -- to attach new itypes to a node in the tree.
6674 pragma Assert (Present (Related_Node));
6676 Itype := Create_Itype (E_Access_Subtype, Related_Node);
6678 Set_Etype (Itype, Base_Type (Old_Type));
6679 Set_Size_Info (Itype, (Old_Type));
6680 Set_Directly_Designated_Type (Itype, Desig_Subtype);
6681 Set_Depends_On_Private (Itype, Has_Private_Component
6683 Set_Is_Access_Constant (Itype, Is_Access_Constant
6686 -- The new itype needs freezing when it depends on a not frozen
6687 -- type and the enclosing subtype needs freezing.
6689 if Has_Delayed_Freeze (Constrained_Typ)
6690 and then not Is_Frozen (Constrained_Typ)
6692 Conditional_Delay (Itype, Base_Type (Old_Type));
6700 end Build_Constrained_Access_Type;
6702 ----------------------------------
6703 -- Build_Constrained_Array_Type --
6704 ----------------------------------
6706 function Build_Constrained_Array_Type
6707 (Old_Type : Entity_Id)
6712 Old_Index : Node_Id;
6713 Range_Node : Node_Id;
6714 Constr_List : List_Id;
6716 Need_To_Create_Itype : Boolean := False;
6719 Old_Index := First_Index (Old_Type);
6720 while Present (Old_Index) loop
6721 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6723 if Is_Discriminant (Lo_Expr)
6724 or else Is_Discriminant (Hi_Expr)
6726 Need_To_Create_Itype := True;
6729 Next_Index (Old_Index);
6732 if Need_To_Create_Itype then
6733 Constr_List := New_List;
6735 Old_Index := First_Index (Old_Type);
6736 while Present (Old_Index) loop
6737 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6739 if Is_Discriminant (Lo_Expr) then
6740 Lo_Expr := Get_Value (Lo_Expr);
6743 if Is_Discriminant (Hi_Expr) then
6744 Hi_Expr := Get_Value (Hi_Expr);
6749 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
6751 Append (Range_Node, To => Constr_List);
6753 Next_Index (Old_Index);
6756 return Build_Subtype (Old_Type, Constr_List);
6761 end Build_Constrained_Array_Type;
6763 ------------------------------------------
6764 -- Build_Constrained_Discriminated_Type --
6765 ------------------------------------------
6767 function Build_Constrained_Discriminated_Type
6768 (Old_Type : Entity_Id)
6772 Constr_List : List_Id;
6773 Old_Constraint : Elmt_Id;
6775 Need_To_Create_Itype : Boolean := False;
6778 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6779 while Present (Old_Constraint) loop
6780 Expr := Node (Old_Constraint);
6782 if Is_Discriminant (Expr) then
6783 Need_To_Create_Itype := True;
6786 Next_Elmt (Old_Constraint);
6789 if Need_To_Create_Itype then
6790 Constr_List := New_List;
6792 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6793 while Present (Old_Constraint) loop
6794 Expr := Node (Old_Constraint);
6796 if Is_Discriminant (Expr) then
6797 Expr := Get_Value (Expr);
6800 Append (New_Copy_Tree (Expr), To => Constr_List);
6802 Next_Elmt (Old_Constraint);
6805 return Build_Subtype (Old_Type, Constr_List);
6810 end Build_Constrained_Discriminated_Type;
6816 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
6818 Subtyp_Decl : Node_Id;
6820 Btyp : Entity_Id := Base_Type (T);
6823 -- The Related_Node better be here or else we won't be able
6824 -- to attach new itypes to a node in the tree.
6826 pragma Assert (Present (Related_Node));
6828 -- If the view of the component's type is incomplete or private
6829 -- with unknown discriminants, then the constraint must be applied
6830 -- to the full type.
6832 if Has_Unknown_Discriminants (Btyp)
6833 and then Present (Underlying_Type (Btyp))
6835 Btyp := Underlying_Type (Btyp);
6839 Make_Subtype_Indication (Loc,
6840 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
6841 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
6843 Def_Id := Create_Itype (Ekind (T), Related_Node);
6846 Make_Subtype_Declaration (Loc,
6847 Defining_Identifier => Def_Id,
6848 Subtype_Indication => Indic);
6849 Set_Parent (Subtyp_Decl, Parent (Related_Node));
6851 -- Itypes must be analyzed with checks off (see itypes.ads).
6853 Analyze (Subtyp_Decl, Suppress => All_Checks);
6862 function Get_Value (Discrim : Entity_Id) return Node_Id is
6863 D : Entity_Id := First_Discriminant (Typ);
6864 E : Elmt_Id := First_Elmt (Constraints);
6867 while Present (D) loop
6869 -- If we are constraining the subtype of a derived tagged type,
6870 -- recover the discriminant of the parent, which appears in
6871 -- the constraint of an inherited component.
6873 if D = Entity (Discrim)
6874 or else Corresponding_Discriminant (D) = Entity (Discrim)
6879 Next_Discriminant (D);
6883 -- Something is wrong if we did not find the value
6885 raise Program_Error;
6888 ---------------------
6889 -- Is_Discriminant --
6890 ---------------------
6892 function Is_Discriminant (Expr : Node_Id) return Boolean is
6893 Discrim_Scope : Entity_Id;
6896 if Denotes_Discriminant (Expr) then
6897 Discrim_Scope := Scope (Entity (Expr));
6899 -- Either we have a reference to one of Typ's discriminants,
6901 pragma Assert (Discrim_Scope = Typ
6903 -- or to the discriminants of the parent type, in the case
6904 -- of a derivation of a tagged type with variants.
6906 or else Discrim_Scope = Etype (Typ)
6907 or else Full_View (Discrim_Scope) = Etype (Typ)
6909 -- or same as above for the case where the discriminants
6910 -- were declared in Typ's private view.
6912 or else (Is_Private_Type (Discrim_Scope)
6913 and then Chars (Discrim_Scope) = Chars (Typ))
6915 -- or else we are deriving from the full view and the
6916 -- discriminant is declared in the private entity.
6918 or else (Is_Private_Type (Typ)
6919 and then Chars (Discrim_Scope) = Chars (Typ))
6921 -- or we have a class-wide type, in which case make sure the
6922 -- discriminant found belongs to the root type.
6924 or else (Is_Class_Wide_Type (Typ)
6925 and then Etype (Typ) = Discrim_Scope));
6930 -- In all other cases we have something wrong.
6933 end Is_Discriminant;
6935 -- Start of processing for Constrain_Component_Type
6938 if Is_Array_Type (Compon_Type) then
6939 return Build_Constrained_Array_Type (Compon_Type);
6941 elsif Has_Discriminants (Compon_Type) then
6942 return Build_Constrained_Discriminated_Type (Compon_Type);
6944 elsif Is_Access_Type (Compon_Type) then
6945 return Build_Constrained_Access_Type (Compon_Type);
6949 end Constrain_Component_Type;
6951 --------------------------
6952 -- Constrain_Concurrent --
6953 --------------------------
6955 -- For concurrent types, the associated record value type carries the same
6956 -- discriminants, so when we constrain a concurrent type, we must constrain
6957 -- the value type as well.
6959 procedure Constrain_Concurrent
6960 (Def_Id : in out Entity_Id;
6962 Related_Nod : Node_Id;
6963 Related_Id : Entity_Id;
6966 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
6970 if Ekind (T_Ent) in Access_Kind then
6971 T_Ent := Designated_Type (T_Ent);
6974 T_Val := Corresponding_Record_Type (T_Ent);
6976 if Present (T_Val) then
6979 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6982 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
6984 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6985 Set_Corresponding_Record_Type (Def_Id,
6986 Constrain_Corresponding_Record
6987 (Def_Id, T_Val, Related_Nod, Related_Id));
6990 -- If there is no associated record, expansion is disabled and this
6991 -- is a generic context. Create a subtype in any case, so that
6992 -- semantic analysis can proceed.
6995 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6998 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7000 end Constrain_Concurrent;
7002 ------------------------------------
7003 -- Constrain_Corresponding_Record --
7004 ------------------------------------
7006 function Constrain_Corresponding_Record
7007 (Prot_Subt : Entity_Id;
7008 Corr_Rec : Entity_Id;
7009 Related_Nod : Node_Id;
7010 Related_Id : Entity_Id)
7013 T_Sub : constant Entity_Id
7014 := Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
7017 Set_Etype (T_Sub, Corr_Rec);
7018 Init_Size_Align (T_Sub);
7019 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
7020 Set_Is_Constrained (T_Sub, True);
7021 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
7022 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
7024 Conditional_Delay (T_Sub, Corr_Rec);
7026 if Has_Discriminants (Prot_Subt) then -- False only if errors.
7027 Set_Discriminant_Constraint (T_Sub,
7028 Discriminant_Constraint (Prot_Subt));
7029 Set_Girder_Constraint_From_Discriminant_Constraint (T_Sub);
7030 Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
7031 Discriminant_Constraint (T_Sub));
7034 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
7037 end Constrain_Corresponding_Record;
7039 -----------------------
7040 -- Constrain_Decimal --
7041 -----------------------
7043 procedure Constrain_Decimal
7046 Related_Nod : Node_Id)
7048 T : constant Entity_Id := Entity (Subtype_Mark (S));
7049 C : constant Node_Id := Constraint (S);
7050 Loc : constant Source_Ptr := Sloc (C);
7051 Range_Expr : Node_Id;
7052 Digits_Expr : Node_Id;
7057 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7059 if Nkind (C) = N_Range_Constraint then
7060 Range_Expr := Range_Expression (C);
7061 Digits_Val := Digits_Value (T);
7064 pragma Assert (Nkind (C) = N_Digits_Constraint);
7065 Digits_Expr := Digits_Expression (C);
7066 Analyze_And_Resolve (Digits_Expr, Any_Integer);
7068 Check_Digits_Expression (Digits_Expr);
7069 Digits_Val := Expr_Value (Digits_Expr);
7071 if Digits_Val > Digits_Value (T) then
7073 ("digits expression is incompatible with subtype", C);
7074 Digits_Val := Digits_Value (T);
7077 if Present (Range_Constraint (C)) then
7078 Range_Expr := Range_Expression (Range_Constraint (C));
7080 Range_Expr := Empty;
7084 Set_Etype (Def_Id, Base_Type (T));
7085 Set_Size_Info (Def_Id, (T));
7086 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7087 Set_Delta_Value (Def_Id, Delta_Value (T));
7088 Set_Scale_Value (Def_Id, Scale_Value (T));
7089 Set_Small_Value (Def_Id, Small_Value (T));
7090 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
7091 Set_Digits_Value (Def_Id, Digits_Val);
7093 -- Manufacture range from given digits value if no range present
7095 if No (Range_Expr) then
7096 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
7100 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
7102 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
7106 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T, Related_Nod);
7107 Set_Discrete_RM_Size (Def_Id);
7109 -- Unconditionally delay the freeze, since we cannot set size
7110 -- information in all cases correctly until the freeze point.
7112 Set_Has_Delayed_Freeze (Def_Id);
7113 end Constrain_Decimal;
7115 ----------------------------------
7116 -- Constrain_Discriminated_Type --
7117 ----------------------------------
7119 procedure Constrain_Discriminated_Type
7120 (Def_Id : Entity_Id;
7122 Related_Nod : Node_Id;
7123 For_Access : Boolean := False)
7127 Elist : Elist_Id := New_Elmt_List;
7129 procedure Fixup_Bad_Constraint;
7130 -- This is called after finding a bad constraint, and after having
7131 -- posted an appropriate error message. The mission is to leave the
7132 -- entity T in as reasonable state as possible!
7134 procedure Fixup_Bad_Constraint is
7136 -- Set a reasonable Ekind for the entity. For an incomplete type,
7137 -- we can't do much, but for other types, we can set the proper
7138 -- corresponding subtype kind.
7140 if Ekind (T) = E_Incomplete_Type then
7141 Set_Ekind (Def_Id, Ekind (T));
7143 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
7146 Set_Etype (Def_Id, Any_Type);
7147 Set_Error_Posted (Def_Id);
7148 end Fixup_Bad_Constraint;
7150 -- Start of processing for Constrain_Discriminated_Type
7153 C := Constraint (S);
7155 -- A discriminant constraint is only allowed in a subtype indication,
7156 -- after a subtype mark. This subtype mark must denote either a type
7157 -- with discriminants, or an access type whose designated type is a
7158 -- type with discriminants. A discriminant constraint specifies the
7159 -- values of these discriminants (RM 3.7.2(5)).
7161 T := Base_Type (Entity (Subtype_Mark (S)));
7163 if Ekind (T) in Access_Kind then
7164 T := Designated_Type (T);
7167 if not Has_Discriminants (T) then
7168 Error_Msg_N ("invalid constraint: type has no discriminant", C);
7169 Fixup_Bad_Constraint;
7172 elsif Is_Constrained (Entity (Subtype_Mark (S))) then
7173 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
7174 Fixup_Bad_Constraint;
7178 -- T may be an unconstrained subtype (e.g. a generic actual).
7179 -- Constraint applies to the base type.
7183 Elist := Build_Discriminant_Constraints (T, S);
7185 -- If the list returned was empty we had an error in building the
7186 -- discriminant constraint. We have also already signalled an error
7187 -- in the incomplete type case
7189 if Is_Empty_Elmt_List (Elist) then
7190 Fixup_Bad_Constraint;
7194 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
7195 end Constrain_Discriminated_Type;
7197 ---------------------------
7198 -- Constrain_Enumeration --
7199 ---------------------------
7201 procedure Constrain_Enumeration
7204 Related_Nod : Node_Id)
7206 T : constant Entity_Id := Entity (Subtype_Mark (S));
7207 C : constant Node_Id := Constraint (S);
7210 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7212 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
7214 Set_Etype (Def_Id, Base_Type (T));
7215 Set_Size_Info (Def_Id, (T));
7216 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7217 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7219 Set_Scalar_Range_For_Subtype
7220 (Def_Id, Range_Expression (C), T, Related_Nod);
7222 Set_Discrete_RM_Size (Def_Id);
7224 end Constrain_Enumeration;
7226 ----------------------
7227 -- Constrain_Float --
7228 ----------------------
7230 procedure Constrain_Float
7233 Related_Nod : Node_Id)
7235 T : constant Entity_Id := Entity (Subtype_Mark (S));
7241 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
7243 Set_Etype (Def_Id, Base_Type (T));
7244 Set_Size_Info (Def_Id, (T));
7245 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7247 -- Process the constraint
7249 C := Constraint (S);
7251 -- Digits constraint present
7253 if Nkind (C) = N_Digits_Constraint then
7254 D := Digits_Expression (C);
7255 Analyze_And_Resolve (D, Any_Integer);
7256 Check_Digits_Expression (D);
7257 Set_Digits_Value (Def_Id, Expr_Value (D));
7259 -- Check that digits value is in range. Obviously we can do this
7260 -- at compile time, but it is strictly a runtime check, and of
7261 -- course there is an ACVC test that checks this!
7263 if Digits_Value (Def_Id) > Digits_Value (T) then
7264 Error_Msg_Uint_1 := Digits_Value (T);
7265 Error_Msg_N ("?digits value is too large, maximum is ^", D);
7266 Rais := Make_Raise_Constraint_Error (Sloc (D));
7267 Insert_Action (Declaration_Node (Def_Id), Rais);
7270 C := Range_Constraint (C);
7272 -- No digits constraint present
7275 Set_Digits_Value (Def_Id, Digits_Value (T));
7278 -- Range constraint present
7280 if Nkind (C) = N_Range_Constraint then
7281 Set_Scalar_Range_For_Subtype
7282 (Def_Id, Range_Expression (C), T, Related_Nod);
7284 -- No range constraint present
7287 pragma Assert (No (C));
7288 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7291 Set_Is_Constrained (Def_Id);
7292 end Constrain_Float;
7294 ---------------------
7295 -- Constrain_Index --
7296 ---------------------
7298 procedure Constrain_Index
7301 Related_Nod : Node_Id;
7302 Related_Id : Entity_Id;
7308 Checks_Off : Boolean := False;
7309 T : constant Entity_Id := Etype (Index);
7312 if Nkind (S) = N_Range
7313 or else Nkind (S) = N_Attribute_Reference
7315 -- A Range attribute will transformed into N_Range by Resolve.
7321 -- ??? Why on earth do we turn checks of in this very specific case ?
7323 -- From the revision history: (Constrain_Index): Call
7324 -- Process_Range_Expr_In_Decl with range checking off for range
7325 -- bounds that are attributes. This avoids some horrible
7326 -- constraint error checks.
7328 if Nkind (R) = N_Range
7329 and then Nkind (Low_Bound (R)) = N_Attribute_Reference
7330 and then Nkind (High_Bound (R)) = N_Attribute_Reference
7335 Process_Range_Expr_In_Decl
7336 (R, T, Related_Nod, Empty_List, Checks_Off);
7338 if not Error_Posted (S)
7340 (Nkind (S) /= N_Range
7341 or else Base_Type (T) /= Base_Type (Etype (Low_Bound (S)))
7342 or else Base_Type (T) /= Base_Type (Etype (High_Bound (S))))
7344 if Base_Type (T) /= Any_Type
7345 and then Etype (Low_Bound (S)) /= Any_Type
7346 and then Etype (High_Bound (S)) /= Any_Type
7348 Error_Msg_N ("range expected", S);
7352 elsif Nkind (S) = N_Subtype_Indication then
7353 -- the parser has verified that this is a discrete indication.
7355 Resolve_Discrete_Subtype_Indication (S, T);
7356 R := Range_Expression (Constraint (S));
7358 elsif Nkind (S) = N_Discriminant_Association then
7360 -- syntactically valid in subtype indication.
7362 Error_Msg_N ("invalid index constraint", S);
7363 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7366 -- Subtype_Mark case, no anonymous subtypes to construct
7371 if Is_Entity_Name (S) then
7373 if not Is_Type (Entity (S)) then
7374 Error_Msg_N ("expect subtype mark for index constraint", S);
7376 elsif Base_Type (Entity (S)) /= Base_Type (T) then
7377 Wrong_Type (S, Base_Type (T));
7383 Error_Msg_N ("invalid index constraint", S);
7384 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7390 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
7392 Set_Etype (Def_Id, Base_Type (T));
7394 if Is_Modular_Integer_Type (T) then
7395 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7397 elsif Is_Integer_Type (T) then
7398 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7401 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7402 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7405 Set_Size_Info (Def_Id, (T));
7406 Set_RM_Size (Def_Id, RM_Size (T));
7407 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7409 -- ??? ??? is R always initialized, not at all obvious why?
7411 Set_Scalar_Range (Def_Id, R);
7413 Set_Etype (S, Def_Id);
7414 Set_Discrete_RM_Size (Def_Id);
7415 end Constrain_Index;
7417 -----------------------
7418 -- Constrain_Integer --
7419 -----------------------
7421 procedure Constrain_Integer
7424 Related_Nod : Node_Id)
7426 T : constant Entity_Id := Entity (Subtype_Mark (S));
7427 C : constant Node_Id := Constraint (S);
7430 Set_Scalar_Range_For_Subtype
7431 (Def_Id, Range_Expression (C), T, Related_Nod);
7433 if Is_Modular_Integer_Type (T) then
7434 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7436 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7439 Set_Etype (Def_Id, Base_Type (T));
7440 Set_Size_Info (Def_Id, (T));
7441 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7442 Set_Discrete_RM_Size (Def_Id);
7444 end Constrain_Integer;
7446 ------------------------------
7447 -- Constrain_Ordinary_Fixed --
7448 ------------------------------
7450 procedure Constrain_Ordinary_Fixed
7453 Related_Nod : Node_Id)
7455 T : constant Entity_Id := Entity (Subtype_Mark (S));
7461 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
7462 Set_Etype (Def_Id, Base_Type (T));
7463 Set_Size_Info (Def_Id, (T));
7464 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7465 Set_Small_Value (Def_Id, Small_Value (T));
7467 -- Process the constraint
7469 C := Constraint (S);
7471 -- Delta constraint present
7473 if Nkind (C) = N_Delta_Constraint then
7474 D := Delta_Expression (C);
7475 Analyze_And_Resolve (D, Any_Real);
7476 Check_Delta_Expression (D);
7477 Set_Delta_Value (Def_Id, Expr_Value_R (D));
7479 -- Check that delta value is in range. Obviously we can do this
7480 -- at compile time, but it is strictly a runtime check, and of
7481 -- course there is an ACVC test that checks this!
7483 if Delta_Value (Def_Id) < Delta_Value (T) then
7484 Error_Msg_N ("?delta value is too small", D);
7485 Rais := Make_Raise_Constraint_Error (Sloc (D));
7486 Insert_Action (Declaration_Node (Def_Id), Rais);
7489 C := Range_Constraint (C);
7491 -- No delta constraint present
7494 Set_Delta_Value (Def_Id, Delta_Value (T));
7497 -- Range constraint present
7499 if Nkind (C) = N_Range_Constraint then
7500 Set_Scalar_Range_For_Subtype
7501 (Def_Id, Range_Expression (C), T, Related_Nod);
7503 -- No range constraint present
7506 pragma Assert (No (C));
7507 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7511 Set_Discrete_RM_Size (Def_Id);
7513 -- Unconditionally delay the freeze, since we cannot set size
7514 -- information in all cases correctly until the freeze point.
7516 Set_Has_Delayed_Freeze (Def_Id);
7517 end Constrain_Ordinary_Fixed;
7519 ---------------------------
7520 -- Convert_Scalar_Bounds --
7521 ---------------------------
7523 procedure Convert_Scalar_Bounds
7525 Parent_Type : Entity_Id;
7526 Derived_Type : Entity_Id;
7529 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
7536 Lo := Build_Scalar_Bound
7537 (Type_Low_Bound (Derived_Type),
7538 Parent_Type, Implicit_Base, Loc);
7540 Hi := Build_Scalar_Bound
7541 (Type_High_Bound (Derived_Type),
7542 Parent_Type, Implicit_Base, Loc);
7549 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
7551 Set_Parent (Rng, N);
7552 Set_Scalar_Range (Derived_Type, Rng);
7554 -- Analyze the bounds
7556 Analyze_And_Resolve (Lo, Implicit_Base);
7557 Analyze_And_Resolve (Hi, Implicit_Base);
7559 -- Analyze the range itself, except that we do not analyze it if
7560 -- the bounds are real literals, and we have a fixed-point type.
7561 -- The reason for this is that we delay setting the bounds in this
7562 -- case till we know the final Small and Size values (see circuit
7563 -- in Freeze.Freeze_Fixed_Point_Type for further details).
7565 if Is_Fixed_Point_Type (Parent_Type)
7566 and then Nkind (Lo) = N_Real_Literal
7567 and then Nkind (Hi) = N_Real_Literal
7571 -- Here we do the analysis of the range.
7573 -- Note: we do this manually, since if we do a normal Analyze and
7574 -- Resolve call, there are problems with the conversions used for
7575 -- the derived type range.
7578 Set_Etype (Rng, Implicit_Base);
7579 Set_Analyzed (Rng, True);
7581 end Convert_Scalar_Bounds;
7587 procedure Copy_And_Swap (Privat, Full : Entity_Id) is
7589 -- Initialize new full declaration entity by copying the pertinent
7590 -- fields of the corresponding private declaration entity.
7592 Copy_Private_To_Full (Privat, Full);
7594 -- Swap the two entities. Now Privat is the full type entity and
7595 -- Full is the private one. They will be swapped back at the end
7596 -- of the private part. This swapping ensures that the entity that
7597 -- is visible in the private part is the full declaration.
7599 Exchange_Entities (Privat, Full);
7600 Append_Entity (Full, Scope (Full));
7603 -------------------------------------
7604 -- Copy_Array_Base_Type_Attributes --
7605 -------------------------------------
7607 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
7609 Set_Component_Alignment (T1, Component_Alignment (T2));
7610 Set_Component_Type (T1, Component_Type (T2));
7611 Set_Component_Size (T1, Component_Size (T2));
7612 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
7613 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
7614 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
7615 Set_Has_Task (T1, Has_Task (T2));
7616 Set_Is_Packed (T1, Is_Packed (T2));
7617 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
7618 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
7619 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
7620 end Copy_Array_Base_Type_Attributes;
7622 -----------------------------------
7623 -- Copy_Array_Subtype_Attributes --
7624 -----------------------------------
7626 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
7628 Set_Size_Info (T1, T2);
7630 Set_First_Index (T1, First_Index (T2));
7631 Set_Is_Aliased (T1, Is_Aliased (T2));
7632 Set_Is_Atomic (T1, Is_Atomic (T2));
7633 Set_Is_Volatile (T1, Is_Volatile (T2));
7634 Set_Is_Constrained (T1, Is_Constrained (T2));
7635 Set_Depends_On_Private (T1, Has_Private_Component (T2));
7636 Set_First_Rep_Item (T1, First_Rep_Item (T2));
7637 Set_Convention (T1, Convention (T2));
7638 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
7639 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
7640 end Copy_Array_Subtype_Attributes;
7642 --------------------------
7643 -- Copy_Private_To_Full --
7644 --------------------------
7646 procedure Copy_Private_To_Full (Priv, Full : Entity_Id) is
7648 -- We temporarily set Ekind to a value appropriate for a type to
7649 -- avoid assert failures in Einfo from checking for setting type
7650 -- attributes on something that is not a type. Ekind (Priv) is an
7651 -- appropriate choice, since it allowed the attributes to be set
7652 -- in the first place. This Ekind value will be modified later.
7654 Set_Ekind (Full, Ekind (Priv));
7656 -- Also set Etype temporarily to Any_Type, again, in the absence
7657 -- of errors, it will be properly reset, and if there are errors,
7658 -- then we want a value of Any_Type to remain.
7660 Set_Etype (Full, Any_Type);
7662 -- Now start copying attributes
7664 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
7666 if Has_Discriminants (Full) then
7667 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
7668 Set_Girder_Constraint (Full, Girder_Constraint (Priv));
7671 Set_Homonym (Full, Homonym (Priv));
7672 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
7673 Set_Is_Public (Full, Is_Public (Priv));
7674 Set_Is_Pure (Full, Is_Pure (Priv));
7675 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
7677 Conditional_Delay (Full, Priv);
7679 if Is_Tagged_Type (Full) then
7680 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
7682 if Priv = Base_Type (Priv) then
7683 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
7687 Set_Is_Volatile (Full, Is_Volatile (Priv));
7688 Set_Scope (Full, Scope (Priv));
7689 Set_Next_Entity (Full, Next_Entity (Priv));
7690 Set_First_Entity (Full, First_Entity (Priv));
7691 Set_Last_Entity (Full, Last_Entity (Priv));
7693 -- If access types have been recorded for later handling, keep them
7694 -- in the full view so that they get handled when the full view freeze
7695 -- node is expanded.
7697 if Present (Freeze_Node (Priv))
7698 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
7700 Ensure_Freeze_Node (Full);
7701 Set_Access_Types_To_Process (Freeze_Node (Full),
7702 Access_Types_To_Process (Freeze_Node (Priv)));
7704 end Copy_Private_To_Full;
7706 -----------------------------------
7707 -- Create_Constrained_Components --
7708 -----------------------------------
7710 procedure Create_Constrained_Components
7712 Decl_Node : Node_Id;
7714 Constraints : Elist_Id)
7716 Loc : constant Source_Ptr := Sloc (Subt);
7717 Assoc_List : List_Id := New_List;
7718 Comp_List : Elist_Id := New_Elmt_List;
7719 Discr_Val : Elmt_Id;
7723 Is_Static : Boolean := True;
7724 Parent_Type : constant Entity_Id := Etype (Typ);
7726 procedure Collect_Fixed_Components (Typ : Entity_Id);
7727 -- Collect components of parent type that do not appear in a variant
7730 procedure Create_All_Components;
7731 -- Iterate over Comp_List to create the components of the subtype.
7733 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
7734 -- Creates a new component from Old_Compon, coppying all the fields from
7735 -- it, including its Etype, inserts the new component in the Subt entity
7736 -- chain and returns the new component.
7738 function Is_Variant_Record (T : Entity_Id) return Boolean;
7739 -- If true, and discriminants are static, collect only components from
7740 -- variants selected by discriminant values.
7742 ------------------------------
7743 -- Collect_Fixed_Components --
7744 ------------------------------
7746 procedure Collect_Fixed_Components (Typ : Entity_Id) is
7748 -- Build association list for discriminants, and find components of
7749 -- the variant part selected by the values of the discriminants.
7751 Old_C := First_Discriminant (Typ);
7752 Discr_Val := First_Elmt (Constraints);
7754 while Present (Old_C) loop
7755 Append_To (Assoc_List,
7756 Make_Component_Association (Loc,
7757 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
7758 Expression => New_Copy (Node (Discr_Val))));
7760 Next_Elmt (Discr_Val);
7761 Next_Discriminant (Old_C);
7764 -- The tag, and the possible parent and controller components
7765 -- are unconditionally in the subtype.
7767 if Is_Tagged_Type (Typ)
7768 or else Has_Controlled_Component (Typ)
7770 Old_C := First_Component (Typ);
7772 while Present (Old_C) loop
7773 if Chars ((Old_C)) = Name_uTag
7774 or else Chars ((Old_C)) = Name_uParent
7775 or else Chars ((Old_C)) = Name_uController
7777 Append_Elmt (Old_C, Comp_List);
7780 Next_Component (Old_C);
7783 end Collect_Fixed_Components;
7785 ---------------------------
7786 -- Create_All_Components --
7787 ---------------------------
7789 procedure Create_All_Components is
7793 Comp := First_Elmt (Comp_List);
7795 while Present (Comp) loop
7796 Old_C := Node (Comp);
7797 New_C := Create_Component (Old_C);
7801 Constrain_Component_Type
7802 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7803 Set_Is_Public (New_C, Is_Public (Subt));
7807 end Create_All_Components;
7809 ----------------------
7810 -- Create_Component --
7811 ----------------------
7813 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
7814 New_Compon : Entity_Id := New_Copy (Old_Compon);
7817 -- Set the parent so we have a proper link for freezing etc. This
7818 -- is not a real parent pointer, since of course our parent does
7819 -- not own up to us and reference us, we are an illegitimate
7820 -- child of the original parent!
7822 Set_Parent (New_Compon, Parent (Old_Compon));
7824 -- We do not want this node marked as Comes_From_Source, since
7825 -- otherwise it would get first class status and a separate
7826 -- cross-reference line would be generated. Illegitimate
7827 -- children do not rate such recognition.
7829 Set_Comes_From_Source (New_Compon, False);
7831 -- But it is a real entity, and a birth certificate must be
7832 -- properly registered by entering it into the entity list.
7834 Enter_Name (New_Compon);
7836 end Create_Component;
7838 -----------------------
7839 -- Is_Variant_Record --
7840 -----------------------
7842 function Is_Variant_Record (T : Entity_Id) return Boolean is
7844 return Nkind (Parent (T)) = N_Full_Type_Declaration
7845 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
7846 and then Present (Component_List (Type_Definition (Parent (T))))
7848 Variant_Part (Component_List (Type_Definition (Parent (T)))));
7849 end Is_Variant_Record;
7851 -- Start of processing for Create_Constrained_Components
7854 pragma Assert (Subt /= Base_Type (Subt));
7855 pragma Assert (Typ = Base_Type (Typ));
7857 Set_First_Entity (Subt, Empty);
7858 Set_Last_Entity (Subt, Empty);
7860 -- Check whether constraint is fully static, in which case we can
7861 -- optimize the list of components.
7863 Discr_Val := First_Elmt (Constraints);
7865 while Present (Discr_Val) loop
7867 if not Is_OK_Static_Expression (Node (Discr_Val)) then
7872 Next_Elmt (Discr_Val);
7877 -- Inherit the discriminants of the parent type.
7879 Old_C := First_Discriminant (Typ);
7881 while Present (Old_C) loop
7882 New_C := Create_Component (Old_C);
7883 Set_Is_Public (New_C, Is_Public (Subt));
7884 Next_Discriminant (Old_C);
7888 and then Is_Variant_Record (Typ)
7890 Collect_Fixed_Components (Typ);
7894 Component_List (Type_Definition (Parent (Typ))),
7895 Governed_By => Assoc_List,
7897 Report_Errors => Errors);
7898 pragma Assert (not Errors);
7900 Create_All_Components;
7902 -- If the subtype declaration is created for a tagged type derivation
7903 -- with constraints, we retrieve the record definition of the parent
7904 -- type to select the components of the proper variant.
7907 and then Is_Tagged_Type (Typ)
7908 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
7910 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
7911 and then Is_Variant_Record (Parent_Type)
7913 Collect_Fixed_Components (Typ);
7917 Component_List (Type_Definition (Parent (Parent_Type))),
7918 Governed_By => Assoc_List,
7920 Report_Errors => Errors);
7921 pragma Assert (not Errors);
7923 -- If the tagged derivation has a type extension, collect all the
7924 -- new components therein.
7927 Record_Extension_Part (Type_Definition (Parent (Typ))))
7929 Old_C := First_Component (Typ);
7931 while Present (Old_C) loop
7932 if Original_Record_Component (Old_C) = Old_C
7933 and then Chars (Old_C) /= Name_uTag
7934 and then Chars (Old_C) /= Name_uParent
7935 and then Chars (Old_C) /= Name_uController
7937 Append_Elmt (Old_C, Comp_List);
7940 Next_Component (Old_C);
7944 Create_All_Components;
7947 -- If the discriminants are not static, or if this is a multi-level
7948 -- type extension, we have to include all the components of the
7951 Old_C := First_Component (Typ);
7953 while Present (Old_C) loop
7954 New_C := Create_Component (Old_C);
7958 Constrain_Component_Type
7959 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7960 Set_Is_Public (New_C, Is_Public (Subt));
7962 Next_Component (Old_C);
7967 end Create_Constrained_Components;
7969 ------------------------------------------
7970 -- Decimal_Fixed_Point_Type_Declaration --
7971 ------------------------------------------
7973 procedure Decimal_Fixed_Point_Type_Declaration
7977 Loc : constant Source_Ptr := Sloc (Def);
7978 Digs_Expr : constant Node_Id := Digits_Expression (Def);
7979 Delta_Expr : constant Node_Id := Delta_Expression (Def);
7980 Implicit_Base : Entity_Id;
7986 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
7989 Check_Restriction (No_Fixed_Point, Def);
7991 -- Create implicit base type
7994 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
7995 Set_Etype (Implicit_Base, Implicit_Base);
7997 -- Analyze and process delta expression
7999 Analyze_And_Resolve (Delta_Expr, Universal_Real);
8001 Check_Delta_Expression (Delta_Expr);
8002 Delta_Val := Expr_Value_R (Delta_Expr);
8004 -- Check delta is power of 10, and determine scale value from it
8007 Val : Ureal := Delta_Val;
8010 Scale_Val := Uint_0;
8012 if Val < Ureal_1 then
8013 while Val < Ureal_1 loop
8014 Val := Val * Ureal_10;
8015 Scale_Val := Scale_Val + 1;
8018 if Scale_Val > 18 then
8019 Error_Msg_N ("scale exceeds maximum value of 18", Def);
8020 Scale_Val := UI_From_Int (+18);
8024 while Val > Ureal_1 loop
8025 Val := Val / Ureal_10;
8026 Scale_Val := Scale_Val - 1;
8029 if Scale_Val < -18 then
8030 Error_Msg_N ("scale is less than minimum value of -18", Def);
8031 Scale_Val := UI_From_Int (-18);
8035 if Val /= Ureal_1 then
8036 Error_Msg_N ("delta expression must be a power of 10", Def);
8037 Delta_Val := Ureal_10 ** (-Scale_Val);
8041 -- Set delta, scale and small (small = delta for decimal type)
8043 Set_Delta_Value (Implicit_Base, Delta_Val);
8044 Set_Scale_Value (Implicit_Base, Scale_Val);
8045 Set_Small_Value (Implicit_Base, Delta_Val);
8047 -- Analyze and process digits expression
8049 Analyze_And_Resolve (Digs_Expr, Any_Integer);
8050 Check_Digits_Expression (Digs_Expr);
8051 Digs_Val := Expr_Value (Digs_Expr);
8053 if Digs_Val > 18 then
8054 Digs_Val := UI_From_Int (+18);
8055 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8058 Set_Digits_Value (Implicit_Base, Digs_Val);
8059 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8061 -- Set range of base type from digits value for now. This will be
8062 -- expanded to represent the true underlying base range by Freeze.
8064 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8066 -- Set size to zero for now, size will be set at freeze time. We have
8067 -- to do this for ordinary fixed-point, because the size depends on
8068 -- the specified small, and we might as well do the same for decimal
8071 Init_Size_Align (Implicit_Base);
8073 -- Complete entity for first subtype
8075 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
8076 Set_Etype (T, Implicit_Base);
8077 Set_Size_Info (T, Implicit_Base);
8078 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
8079 Set_Digits_Value (T, Digs_Val);
8080 Set_Delta_Value (T, Delta_Val);
8081 Set_Small_Value (T, Delta_Val);
8082 Set_Scale_Value (T, Scale_Val);
8083 Set_Is_Constrained (T);
8085 -- If there are bounds given in the declaration use them as the
8086 -- bounds of the first named subtype.
8088 if Present (Real_Range_Specification (Def)) then
8090 RRS : constant Node_Id := Real_Range_Specification (Def);
8091 Low : constant Node_Id := Low_Bound (RRS);
8092 High : constant Node_Id := High_Bound (RRS);
8097 Analyze_And_Resolve (Low, Any_Real);
8098 Analyze_And_Resolve (High, Any_Real);
8099 Check_Real_Bound (Low);
8100 Check_Real_Bound (High);
8101 Low_Val := Expr_Value_R (Low);
8102 High_Val := Expr_Value_R (High);
8104 if Low_Val < (-Bound_Val) then
8106 ("range low bound too small for digits value", Low);
8107 Low_Val := -Bound_Val;
8110 if High_Val > Bound_Val then
8112 ("range high bound too large for digits value", High);
8113 High_Val := Bound_Val;
8116 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
8119 -- If no explicit range, use range that corresponds to given
8120 -- digits value. This will end up as the final range for the
8124 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
8127 end Decimal_Fixed_Point_Type_Declaration;
8129 -----------------------
8130 -- Derive_Subprogram --
8131 -----------------------
8133 procedure Derive_Subprogram
8134 (New_Subp : in out Entity_Id;
8135 Parent_Subp : Entity_Id;
8136 Derived_Type : Entity_Id;
8137 Parent_Type : Entity_Id;
8138 Actual_Subp : Entity_Id := Empty)
8141 New_Formal : Entity_Id;
8142 Same_Subt : constant Boolean :=
8143 Is_Scalar_Type (Parent_Type)
8144 and then Subtypes_Statically_Compatible (Parent_Type, Derived_Type);
8146 function Is_Private_Overriding return Boolean;
8147 -- If Subp is a private overriding of a visible operation, the in-
8148 -- herited operation derives from the overridden op (even though
8149 -- its body is the overriding one) and the inherited operation is
8150 -- visible now. See sem_disp to see the details of the handling of
8151 -- the overridden subprogram, which is removed from the list of
8152 -- primitive operations of the type.
8154 procedure Replace_Type (Id, New_Id : Entity_Id);
8155 -- When the type is an anonymous access type, create a new access type
8156 -- designating the derived type.
8158 ---------------------------
8159 -- Is_Private_Overriding --
8160 ---------------------------
8162 function Is_Private_Overriding return Boolean is
8166 Prev := Homonym (Parent_Subp);
8168 -- The visible operation that is overriden is a homonym of
8169 -- the parent subprogram. We scan the homonym chain to find
8170 -- the one whose alias is the subprogram we are deriving.
8172 while Present (Prev) loop
8173 if Is_Dispatching_Operation (Parent_Subp)
8174 and then Present (Prev)
8175 and then Ekind (Prev) = Ekind (Parent_Subp)
8176 and then Alias (Prev) = Parent_Subp
8177 and then Scope (Parent_Subp) = Scope (Prev)
8178 and then not Is_Hidden (Prev)
8183 Prev := Homonym (Prev);
8187 end Is_Private_Overriding;
8193 procedure Replace_Type (Id, New_Id : Entity_Id) is
8194 Acc_Type : Entity_Id;
8198 -- When the type is an anonymous access type, create a new access
8199 -- type designating the derived type. This itype must be elaborated
8200 -- at the point of the derivation, not on subsequent calls that may
8201 -- be out of the proper scope for Gigi, so we insert a reference to
8202 -- it after the derivation.
8204 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
8206 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
8209 if Ekind (Desig_Typ) = E_Record_Type_With_Private
8210 and then Present (Full_View (Desig_Typ))
8211 and then not Is_Private_Type (Parent_Type)
8213 Desig_Typ := Full_View (Desig_Typ);
8216 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
8217 Acc_Type := New_Copy (Etype (Id));
8218 Set_Etype (Acc_Type, Acc_Type);
8219 Set_Scope (Acc_Type, New_Subp);
8221 -- Compute size of anonymous access type.
8223 if Is_Array_Type (Desig_Typ)
8224 and then not Is_Constrained (Desig_Typ)
8226 Init_Size (Acc_Type, 2 * System_Address_Size);
8228 Init_Size (Acc_Type, System_Address_Size);
8231 Init_Alignment (Acc_Type);
8233 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
8235 Set_Etype (New_Id, Acc_Type);
8236 Set_Scope (New_Id, New_Subp);
8238 -- Create a reference to it.
8240 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
8241 Set_Itype (IR, Acc_Type);
8242 Insert_After (Parent (Derived_Type), IR);
8245 Set_Etype (New_Id, Etype (Id));
8248 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
8250 (Ekind (Etype (Id)) = E_Record_Type_With_Private
8251 and then Present (Full_View (Etype (Id)))
8252 and then Base_Type (Full_View (Etype (Id))) =
8253 Base_Type (Parent_Type))
8256 -- Constraint checks on formals are generated during expansion,
8257 -- based on the signature of the original subprogram. The bounds
8258 -- of the derived type are not relevant, and thus we can use
8259 -- the base type for the formals. However, the return type may be
8260 -- used in a context that requires that the proper static bounds
8261 -- be used (a case statement, for example) and for those cases
8262 -- we must use the derived type (first subtype), not its base.
8264 if Etype (Id) = Parent_Type
8267 Set_Etype (New_Id, Derived_Type);
8269 Set_Etype (New_Id, Base_Type (Derived_Type));
8273 Set_Etype (New_Id, Etype (Id));
8277 -- Start of processing for Derive_Subprogram
8281 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
8282 Set_Ekind (New_Subp, Ekind (Parent_Subp));
8284 -- Check whether the inherited subprogram is a private operation that
8285 -- should be inherited but not yet made visible. Such subprograms can
8286 -- become visible at a later point (e.g., the private part of a public
8287 -- child unit) via Declare_Inherited_Private_Subprograms. If the
8288 -- following predicate is true, then this is not such a private
8289 -- operation and the subprogram simply inherits the name of the parent
8290 -- subprogram. Note the special check for the names of controlled
8291 -- operations, which are currently exempted from being inherited with
8292 -- a hidden name because they must be findable for generation of
8293 -- implicit run-time calls.
8295 if not Is_Hidden (Parent_Subp)
8296 or else Is_Internal (Parent_Subp)
8297 or else Is_Private_Overriding
8298 or else Is_Internal_Name (Chars (Parent_Subp))
8299 or else Chars (Parent_Subp) = Name_Initialize
8300 or else Chars (Parent_Subp) = Name_Adjust
8301 or else Chars (Parent_Subp) = Name_Finalize
8303 Set_Chars (New_Subp, Chars (Parent_Subp));
8305 -- If parent is hidden, this can be a regular derivation if the
8306 -- parent is immediately visible in a non-instantiating context,
8307 -- or if we are in the private part of an instance. This test
8308 -- should still be refined ???
8310 -- The test for In_Instance_Not_Visible avoids inheriting the
8311 -- derived operation as a non-visible operation in cases where
8312 -- the parent subprogram might not be visible now, but was
8313 -- visible within the original generic, so it would be wrong
8314 -- to make the inherited subprogram non-visible now. (Not
8315 -- clear if this test is fully correct; are there any cases
8316 -- where we should declare the inherited operation as not
8317 -- visible to avoid it being overridden, e.g., when the
8318 -- parent type is a generic actual with private primitives ???)
8320 -- (they should be treated the same as other private inherited
8321 -- subprograms, but it's not clear how to do this cleanly). ???
8323 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
8324 and then Is_Immediately_Visible (Parent_Subp)
8325 and then not In_Instance)
8326 or else In_Instance_Not_Visible
8328 Set_Chars (New_Subp, Chars (Parent_Subp));
8330 -- The type is inheriting a private operation, so enter
8331 -- it with a special name so it can't be overridden.
8334 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
8337 Set_Parent (New_Subp, Parent (Derived_Type));
8338 Replace_Type (Parent_Subp, New_Subp);
8339 Conditional_Delay (New_Subp, Parent_Subp);
8341 Formal := First_Formal (Parent_Subp);
8342 while Present (Formal) loop
8343 New_Formal := New_Copy (Formal);
8345 -- Normally we do not go copying parents, but in the case of
8346 -- formals, we need to link up to the declaration (which is
8347 -- the parameter specification), and it is fine to link up to
8348 -- the original formal's parameter specification in this case.
8350 Set_Parent (New_Formal, Parent (Formal));
8352 Append_Entity (New_Formal, New_Subp);
8354 Replace_Type (Formal, New_Formal);
8355 Next_Formal (Formal);
8358 -- If this derivation corresponds to a tagged generic actual, then
8359 -- primitive operations rename those of the actual. Otherwise the
8360 -- primitive operations rename those of the parent type.
8362 if No (Actual_Subp) then
8363 Set_Alias (New_Subp, Parent_Subp);
8364 Set_Is_Intrinsic_Subprogram (New_Subp,
8365 Is_Intrinsic_Subprogram (Parent_Subp));
8368 Set_Alias (New_Subp, Actual_Subp);
8371 -- Derived subprograms of a tagged type must inherit the convention
8372 -- of the parent subprogram (a requirement of AI-117). Derived
8373 -- subprograms of untagged types simply get convention Ada by default.
8375 if Is_Tagged_Type (Derived_Type) then
8376 Set_Convention (New_Subp, Convention (Parent_Subp));
8379 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
8380 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
8382 if Ekind (Parent_Subp) = E_Procedure then
8383 Set_Is_Valued_Procedure
8384 (New_Subp, Is_Valued_Procedure (Parent_Subp));
8387 New_Overloaded_Entity (New_Subp, Derived_Type);
8389 -- Check for case of a derived subprogram for the instantiation
8390 -- of a formal derived tagged type, so mark the subprogram as
8391 -- dispatching and inherit the dispatching attributes of the
8392 -- parent subprogram. The derived subprogram is effectively a
8393 -- renaming of the actual subprogram, so it needs to have the
8394 -- same attributes as the actual.
8396 if Present (Actual_Subp)
8397 and then Is_Dispatching_Operation (Parent_Subp)
8399 Set_Is_Dispatching_Operation (New_Subp);
8400 if Present (DTC_Entity (Parent_Subp)) then
8401 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
8402 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
8406 -- Indicate that a derived subprogram does not require a body
8407 -- and that it does not require processing of default expressions.
8409 Set_Has_Completion (New_Subp);
8410 Set_Default_Expressions_Processed (New_Subp);
8412 -- A derived function with a controlling result is abstract.
8413 -- If the Derived_Type is a nonabstract formal generic derived
8414 -- type, then inherited operations are not abstract: check is
8415 -- done at instantiation time. If the derivation is for a generic
8416 -- actual, the function is not abstract unless the actual is.
8418 if Is_Generic_Type (Derived_Type)
8419 and then not Is_Abstract (Derived_Type)
8423 elsif Is_Abstract (Alias (New_Subp))
8424 or else (Is_Tagged_Type (Derived_Type)
8425 and then Etype (New_Subp) = Derived_Type
8426 and then No (Actual_Subp))
8428 Set_Is_Abstract (New_Subp);
8431 if Ekind (New_Subp) = E_Function then
8432 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
8434 end Derive_Subprogram;
8436 ------------------------
8437 -- Derive_Subprograms --
8438 ------------------------
8440 procedure Derive_Subprograms
8441 (Parent_Type : Entity_Id;
8442 Derived_Type : Entity_Id;
8443 Generic_Actual : Entity_Id := Empty)
8445 Op_List : Elist_Id := Collect_Primitive_Operations (Parent_Type);
8446 Act_List : Elist_Id;
8450 New_Subp : Entity_Id := Empty;
8451 Parent_Base : Entity_Id;
8454 if Ekind (Parent_Type) = E_Record_Type_With_Private
8455 and then Has_Discriminants (Parent_Type)
8456 and then Present (Full_View (Parent_Type))
8458 Parent_Base := Full_View (Parent_Type);
8460 Parent_Base := Parent_Type;
8463 Elmt := First_Elmt (Op_List);
8465 if Present (Generic_Actual) then
8466 Act_List := Collect_Primitive_Operations (Generic_Actual);
8467 Act_Elmt := First_Elmt (Act_List);
8469 Act_Elmt := No_Elmt;
8472 -- Literals are derived earlier in the process of building the
8473 -- derived type, and are skipped here.
8475 while Present (Elmt) loop
8476 Subp := Node (Elmt);
8478 if Ekind (Subp) /= E_Enumeration_Literal then
8479 if No (Generic_Actual) then
8481 (New_Subp, Subp, Derived_Type, Parent_Base);
8484 Derive_Subprogram (New_Subp, Subp,
8485 Derived_Type, Parent_Base, Node (Act_Elmt));
8486 Next_Elmt (Act_Elmt);
8492 end Derive_Subprograms;
8494 --------------------------------
8495 -- Derived_Standard_Character --
8496 --------------------------------
8498 procedure Derived_Standard_Character
8500 Parent_Type : Entity_Id;
8501 Derived_Type : Entity_Id)
8503 Loc : constant Source_Ptr := Sloc (N);
8504 Def : constant Node_Id := Type_Definition (N);
8505 Indic : constant Node_Id := Subtype_Indication (Def);
8506 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8507 Implicit_Base : constant Entity_Id :=
8509 (E_Enumeration_Type, N, Derived_Type, 'B');
8516 T := Process_Subtype (Indic, N);
8518 Set_Etype (Implicit_Base, Parent_Base);
8519 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
8520 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
8522 Set_Is_Character_Type (Implicit_Base, True);
8523 Set_Has_Delayed_Freeze (Implicit_Base);
8525 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
8526 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
8528 Set_Scalar_Range (Implicit_Base,
8533 Conditional_Delay (Derived_Type, Parent_Type);
8535 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
8536 Set_Etype (Derived_Type, Implicit_Base);
8537 Set_Size_Info (Derived_Type, Parent_Type);
8539 if Unknown_RM_Size (Derived_Type) then
8540 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8543 Set_Is_Character_Type (Derived_Type, True);
8545 if Nkind (Indic) /= N_Subtype_Indication then
8546 Set_Scalar_Range (Derived_Type, Scalar_Range (Implicit_Base));
8549 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
8551 -- Because the implicit base is used in the conversion of the bounds,
8552 -- we have to freeze it now. This is similar to what is done for
8553 -- numeric types, and it equally suspicious, but otherwise a non-
8554 -- static bound will have a reference to an unfrozen type, which is
8555 -- rejected by Gigi (???).
8557 Freeze_Before (N, Implicit_Base);
8559 end Derived_Standard_Character;
8561 ------------------------------
8562 -- Derived_Type_Declaration --
8563 ------------------------------
8565 procedure Derived_Type_Declaration
8568 Is_Completion : Boolean)
8570 Def : constant Node_Id := Type_Definition (N);
8571 Indic : constant Node_Id := Subtype_Indication (Def);
8572 Extension : constant Node_Id := Record_Extension_Part (Def);
8573 Parent_Type : Entity_Id;
8574 Parent_Scope : Entity_Id;
8578 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
8580 if Parent_Type = Any_Type
8581 or else Etype (Parent_Type) = Any_Type
8582 or else (Is_Class_Wide_Type (Parent_Type)
8583 and then Etype (Parent_Type) = T)
8585 -- If Parent_Type is undefined or illegal, make new type into
8586 -- a subtype of Any_Type, and set a few attributes to prevent
8587 -- cascaded errors. If this is a self-definition, emit error now.
8590 or else T = Etype (Parent_Type)
8592 Error_Msg_N ("type cannot be used in its own definition", Indic);
8595 Set_Ekind (T, Ekind (Parent_Type));
8596 Set_Etype (T, Any_Type);
8597 Set_Scalar_Range (T, Scalar_Range (Any_Type));
8599 if Is_Tagged_Type (T) then
8600 Set_Primitive_Operations (T, New_Elmt_List);
8604 elsif Is_Unchecked_Union (Parent_Type) then
8605 Error_Msg_N ("cannot derive from Unchecked_Union type", N);
8608 -- Only composite types other than array types are allowed to have
8611 if Present (Discriminant_Specifications (N))
8612 and then (Is_Elementary_Type (Parent_Type)
8613 or else Is_Array_Type (Parent_Type))
8614 and then not Error_Posted (N)
8617 ("elementary or array type cannot have discriminants",
8618 Defining_Identifier (First (Discriminant_Specifications (N))));
8619 Set_Has_Discriminants (T, False);
8622 -- In Ada 83, a derived type defined in a package specification cannot
8623 -- be used for further derivation until the end of its visible part.
8624 -- Note that derivation in the private part of the package is allowed.
8627 and then Is_Derived_Type (Parent_Type)
8628 and then In_Visible_Part (Scope (Parent_Type))
8630 if Ada_83 and then Comes_From_Source (Indic) then
8632 ("(Ada 83): premature use of type for derivation", Indic);
8636 -- Check for early use of incomplete or private type
8638 if Ekind (Parent_Type) = E_Void
8639 or else Ekind (Parent_Type) = E_Incomplete_Type
8641 Error_Msg_N ("premature derivation of incomplete type", Indic);
8644 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
8645 and then not Is_Generic_Type (Parent_Type)
8646 and then not Is_Generic_Type (Root_Type (Parent_Type))
8647 and then not Is_Generic_Actual_Type (Parent_Type))
8648 or else Has_Private_Component (Parent_Type)
8650 -- The ancestor type of a formal type can be incomplete, in which
8651 -- case only the operations of the partial view are available in
8652 -- the generic. Subsequent checks may be required when the full
8653 -- view is analyzed, to verify that derivation from a tagged type
8654 -- has an extension.
8656 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
8659 elsif No (Underlying_Type (Parent_Type))
8660 or else Has_Private_Component (Parent_Type)
8663 ("premature derivation of derived or private type", Indic);
8665 -- Flag the type itself as being in error, this prevents some
8666 -- nasty problems with people looking at the malformed type.
8668 Set_Error_Posted (T);
8670 -- Check that within the immediate scope of an untagged partial
8671 -- view it's illegal to derive from the partial view if the
8672 -- full view is tagged. (7.3(7))
8674 -- We verify that the Parent_Type is a partial view by checking
8675 -- that it is not a Full_Type_Declaration (i.e. a private type or
8676 -- private extension declaration), to distinguish a partial view
8677 -- from a derivation from a private type which also appears as
8680 elsif Present (Full_View (Parent_Type))
8681 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
8682 and then not Is_Tagged_Type (Parent_Type)
8683 and then Is_Tagged_Type (Full_View (Parent_Type))
8685 Parent_Scope := Scope (T);
8686 while Present (Parent_Scope)
8687 and then Parent_Scope /= Standard_Standard
8689 if Parent_Scope = Scope (Parent_Type) then
8691 ("premature derivation from type with tagged full view",
8695 Parent_Scope := Scope (Parent_Scope);
8700 -- Check that form of derivation is appropriate
8702 Taggd := Is_Tagged_Type (Parent_Type);
8704 -- Perhaps the parent type should be changed to the class-wide type's
8705 -- specific type in this case to prevent cascading errors ???
8707 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
8708 Error_Msg_N ("parent type must not be a class-wide type", Indic);
8712 if Present (Extension) and then not Taggd then
8714 ("type derived from untagged type cannot have extension", Indic);
8716 elsif No (Extension) and then Taggd then
8717 -- If this is within a private part (or body) of a generic
8718 -- instantiation then the derivation is allowed (the parent
8719 -- type can only appear tagged in this case if it's a generic
8720 -- actual type, since it would otherwise have been rejected
8721 -- in the analysis of the generic template).
8723 if not Is_Generic_Actual_Type (Parent_Type)
8724 or else In_Visible_Part (Scope (Parent_Type))
8727 ("type derived from tagged type must have extension", Indic);
8731 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
8732 end Derived_Type_Declaration;
8734 ----------------------------------
8735 -- Enumeration_Type_Declaration --
8736 ----------------------------------
8738 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
8745 -- Create identifier node representing lower bound
8747 B_Node := New_Node (N_Identifier, Sloc (Def));
8748 L := First (Literals (Def));
8749 Set_Chars (B_Node, Chars (L));
8750 Set_Entity (B_Node, L);
8751 Set_Etype (B_Node, T);
8752 Set_Is_Static_Expression (B_Node, True);
8754 R_Node := New_Node (N_Range, Sloc (Def));
8755 Set_Low_Bound (R_Node, B_Node);
8757 Set_Ekind (T, E_Enumeration_Type);
8758 Set_First_Literal (T, L);
8760 Set_Is_Constrained (T);
8764 -- Loop through literals of enumeration type setting pos and rep values
8765 -- except that if the Ekind is already set, then it means that the
8766 -- literal was already constructed (case of a derived type declaration
8767 -- and we should not disturb the Pos and Rep values.
8769 while Present (L) loop
8770 if Ekind (L) /= E_Enumeration_Literal then
8771 Set_Ekind (L, E_Enumeration_Literal);
8772 Set_Enumeration_Pos (L, Ev);
8773 Set_Enumeration_Rep (L, Ev);
8774 Set_Is_Known_Valid (L, True);
8778 New_Overloaded_Entity (L);
8779 Generate_Definition (L);
8780 Set_Convention (L, Convention_Intrinsic);
8782 if Nkind (L) = N_Defining_Character_Literal then
8783 Set_Is_Character_Type (T, True);
8790 -- Now create a node representing upper bound
8792 B_Node := New_Node (N_Identifier, Sloc (Def));
8793 Set_Chars (B_Node, Chars (Last (Literals (Def))));
8794 Set_Entity (B_Node, Last (Literals (Def)));
8795 Set_Etype (B_Node, T);
8796 Set_Is_Static_Expression (B_Node, True);
8798 Set_High_Bound (R_Node, B_Node);
8799 Set_Scalar_Range (T, R_Node);
8800 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
8803 -- Set Discard_Names if configuration pragma setg, or if there is
8804 -- a parameterless pragma in the current declarative region
8806 if Global_Discard_Names
8807 or else Discard_Names (Scope (T))
8809 Set_Discard_Names (T);
8811 end Enumeration_Type_Declaration;
8813 --------------------------
8814 -- Expand_Others_Choice --
8815 --------------------------
8817 procedure Expand_Others_Choice
8818 (Case_Table : Choice_Table_Type;
8819 Others_Choice : Node_Id;
8820 Choice_Type : Entity_Id)
8823 Choice_List : List_Id := New_List;
8828 Loc : Source_Ptr := Sloc (Others_Choice);
8831 function Build_Choice (Value1, Value2 : Uint) return Node_Id;
8832 -- Builds a node representing the missing choices given by the
8833 -- Value1 and Value2. A N_Range node is built if there is more than
8834 -- one literal value missing. Otherwise a single N_Integer_Literal,
8835 -- N_Identifier or N_Character_Literal is built depending on what
8838 function Lit_Of (Value : Uint) return Node_Id;
8839 -- Returns the Node_Id for the enumeration literal corresponding to the
8840 -- position given by Value within the enumeration type Choice_Type.
8846 function Build_Choice (Value1, Value2 : Uint) return Node_Id is
8851 -- If there is only one choice value missing between Value1 and
8852 -- Value2, build an integer or enumeration literal to represent it.
8854 if (Value2 - Value1) = 0 then
8855 if Is_Integer_Type (Choice_Type) then
8856 Lit_Node := Make_Integer_Literal (Loc, Value1);
8857 Set_Etype (Lit_Node, Choice_Type);
8859 Lit_Node := Lit_Of (Value1);
8862 -- Otherwise is more that one choice value that is missing between
8863 -- Value1 and Value2, therefore build a N_Range node of either
8864 -- integer or enumeration literals.
8867 if Is_Integer_Type (Choice_Type) then
8868 Lo := Make_Integer_Literal (Loc, Value1);
8869 Set_Etype (Lo, Choice_Type);
8870 Hi := Make_Integer_Literal (Loc, Value2);
8871 Set_Etype (Hi, Choice_Type);
8880 Low_Bound => Lit_Of (Value1),
8881 High_Bound => Lit_Of (Value2));
8892 function Lit_Of (Value : Uint) return Node_Id is
8896 -- In the case where the literal is of type Character, there needs
8897 -- to be some special handling since there is no explicit chain
8898 -- of literals to search. Instead, a N_Character_Literal node
8899 -- is created with the appropriate Char_Code and Chars fields.
8901 if Root_Type (Choice_Type) = Standard_Character then
8902 Set_Character_Literal_Name (Char_Code (UI_To_Int (Value)));
8903 Lit := New_Node (N_Character_Literal, Loc);
8904 Set_Chars (Lit, Name_Find);
8905 Set_Char_Literal_Value (Lit, Char_Code (UI_To_Int (Value)));
8906 Set_Etype (Lit, Choice_Type);
8907 Set_Is_Static_Expression (Lit, True);
8910 -- Otherwise, iterate through the literals list of Choice_Type
8911 -- "Value" number of times until the desired literal is reached
8912 -- and then return an occurrence of it.
8915 Lit := First_Literal (Choice_Type);
8916 for J in 1 .. UI_To_Int (Value) loop
8920 return New_Occurrence_Of (Lit, Loc);
8924 -- Start of processing for Expand_Others_Choice
8927 if Case_Table'Length = 0 then
8929 -- Pathological case: only an others case is present.
8930 -- The others case covers the full range of the type.
8932 if Is_Static_Subtype (Choice_Type) then
8933 Choice := New_Occurrence_Of (Choice_Type, Loc);
8935 Choice := New_Occurrence_Of (Base_Type (Choice_Type), Loc);
8938 Set_Others_Discrete_Choices (Others_Choice, New_List (Choice));
8942 -- Establish the bound values for the variant depending upon whether
8943 -- the type of the discriminant name is static or not.
8945 if Is_OK_Static_Subtype (Choice_Type) then
8946 Exp_Lo := Type_Low_Bound (Choice_Type);
8947 Exp_Hi := Type_High_Bound (Choice_Type);
8949 Exp_Lo := Type_Low_Bound (Base_Type (Choice_Type));
8950 Exp_Hi := Type_High_Bound (Base_Type (Choice_Type));
8953 Lo := Expr_Value (Case_Table (Case_Table'First).Lo);
8954 Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8955 Previous_Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8957 -- Build the node for any missing choices that are smaller than any
8958 -- explicit choices given in the variant.
8960 if Expr_Value (Exp_Lo) < Lo then
8961 Append (Build_Choice (Expr_Value (Exp_Lo), Lo - 1), Choice_List);
8964 -- Build the nodes representing any missing choices that lie between
8965 -- the explicit ones given in the variant.
8967 for J in Case_Table'First + 1 .. Case_Table'Last loop
8968 Lo := Expr_Value (Case_Table (J).Lo);
8969 Hi := Expr_Value (Case_Table (J).Hi);
8971 if Lo /= (Previous_Hi + 1) then
8972 Append_To (Choice_List, Build_Choice (Previous_Hi + 1, Lo - 1));
8978 -- Build the node for any missing choices that are greater than any
8979 -- explicit choices given in the variant.
8981 if Expr_Value (Exp_Hi) > Hi then
8982 Append (Build_Choice (Hi + 1, Expr_Value (Exp_Hi)), Choice_List);
8985 Set_Others_Discrete_Choices (Others_Choice, Choice_List);
8986 end Expand_Others_Choice;
8988 ---------------------------------
8989 -- Expand_To_Girder_Constraint --
8990 ---------------------------------
8992 function Expand_To_Girder_Constraint
8994 Constraint : Elist_Id)
8997 Explicitly_Discriminated_Type : Entity_Id;
8998 Expansion : Elist_Id;
8999 Discriminant : Entity_Id;
9001 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
9002 -- Find the nearest type that actually specifies discriminants.
9004 ---------------------------------
9005 -- Type_With_Explicit_Discrims --
9006 ---------------------------------
9008 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
9009 Typ : constant E := Base_Type (Id);
9012 if Ekind (Typ) in Incomplete_Or_Private_Kind then
9013 if Present (Full_View (Typ)) then
9014 return Type_With_Explicit_Discrims (Full_View (Typ));
9018 if Has_Discriminants (Typ) then
9023 if Etype (Typ) = Typ then
9025 elsif Has_Discriminants (Typ) then
9028 return Type_With_Explicit_Discrims (Etype (Typ));
9031 end Type_With_Explicit_Discrims;
9033 -- Start of processing for Expand_To_Girder_Constraint
9037 or else Is_Empty_Elmt_List (Constraint)
9042 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
9044 if No (Explicitly_Discriminated_Type) then
9048 Expansion := New_Elmt_List;
9051 First_Girder_Discriminant (Explicitly_Discriminated_Type);
9053 while Present (Discriminant) loop
9056 Get_Discriminant_Value (
9057 Discriminant, Explicitly_Discriminated_Type, Constraint),
9060 Next_Girder_Discriminant (Discriminant);
9064 end Expand_To_Girder_Constraint;
9066 --------------------
9067 -- Find_Type_Name --
9068 --------------------
9070 function Find_Type_Name (N : Node_Id) return Entity_Id is
9071 Id : constant Entity_Id := Defining_Identifier (N);
9077 -- Find incomplete declaration, if some was given.
9079 Prev := Current_Entity_In_Scope (Id);
9081 if Present (Prev) then
9083 -- Previous declaration exists. Error if not incomplete/private case
9084 -- except if previous declaration is implicit, etc. Enter_Name will
9085 -- emit error if appropriate.
9087 Prev_Par := Parent (Prev);
9089 if not Is_Incomplete_Or_Private_Type (Prev) then
9093 elsif Nkind (N) /= N_Full_Type_Declaration
9094 and then Nkind (N) /= N_Task_Type_Declaration
9095 and then Nkind (N) /= N_Protected_Type_Declaration
9097 -- Completion must be a full type declarations (RM 7.3(4))
9099 Error_Msg_Sloc := Sloc (Prev);
9100 Error_Msg_NE ("invalid completion of }", Id, Prev);
9102 -- Set scope of Id to avoid cascaded errors. Entity is never
9103 -- examined again, except when saving globals in generics.
9105 Set_Scope (Id, Current_Scope);
9108 -- Case of full declaration of incomplete type
9110 elsif Ekind (Prev) = E_Incomplete_Type then
9112 -- Indicate that the incomplete declaration has a matching
9113 -- full declaration. The defining occurrence of the incomplete
9114 -- declaration remains the visible one, and the procedure
9115 -- Get_Full_View dereferences it whenever the type is used.
9117 if Present (Full_View (Prev)) then
9118 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9121 Set_Full_View (Prev, Id);
9122 Append_Entity (Id, Current_Scope);
9123 Set_Is_Public (Id, Is_Public (Prev));
9124 Set_Is_Internal (Id);
9127 -- Case of full declaration of private type
9130 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9131 if Etype (Prev) /= Prev then
9133 -- Prev is a private subtype or a derived type, and needs
9136 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9139 elsif Ekind (Prev) = E_Private_Type
9141 (Nkind (N) = N_Task_Type_Declaration
9142 or else Nkind (N) = N_Protected_Type_Declaration)
9145 ("completion of nonlimited type cannot be limited", N);
9148 elsif Nkind (N) /= N_Full_Type_Declaration
9149 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9151 Error_Msg_N ("full view of private extension must be"
9152 & " an extension", N);
9154 elsif not (Abstract_Present (Parent (Prev)))
9155 and then Abstract_Present (Type_Definition (N))
9157 Error_Msg_N ("full view of non-abstract extension cannot"
9158 & " be abstract", N);
9161 if not In_Private_Part (Current_Scope) then
9163 ("declaration of full view must appear in private part", N);
9166 Copy_And_Swap (Prev, Id);
9167 Set_Full_View (Id, Prev);
9168 Set_Has_Private_Declaration (Prev);
9169 Set_Has_Private_Declaration (Id);
9173 -- Verify that full declaration conforms to incomplete one
9175 if Is_Incomplete_Or_Private_Type (Prev)
9176 and then Present (Discriminant_Specifications (Prev_Par))
9178 if Present (Discriminant_Specifications (N)) then
9179 if Ekind (Prev) = E_Incomplete_Type then
9180 Check_Discriminant_Conformance (N, Prev, Prev);
9182 Check_Discriminant_Conformance (N, Prev, Id);
9187 ("missing discriminants in full type declaration", N);
9189 -- To avoid cascaded errors on subsequent use, share the
9190 -- discriminants of the partial view.
9192 Set_Discriminant_Specifications (N,
9193 Discriminant_Specifications (Prev_Par));
9197 -- A prior untagged private type can have an associated
9198 -- class-wide type due to use of the class attribute,
9199 -- and in this case also the full type is required to
9203 and then (Is_Tagged_Type (Prev)
9204 or else Present (Class_Wide_Type (Prev)))
9206 -- The full declaration is either a tagged record or an
9207 -- extension otherwise this is an error
9209 if Nkind (Type_Definition (N)) = N_Record_Definition then
9210 if not Tagged_Present (Type_Definition (N)) then
9212 ("full declaration of } must be tagged", Prev, Id);
9213 Set_Is_Tagged_Type (Id);
9214 Set_Primitive_Operations (Id, New_Elmt_List);
9217 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
9218 if No (Record_Extension_Part (Type_Definition (N))) then
9220 "full declaration of } must be a record extension",
9222 Set_Is_Tagged_Type (Id);
9223 Set_Primitive_Operations (Id, New_Elmt_List);
9228 ("full declaration of } must be a tagged type", Prev, Id);
9236 -- New type declaration
9243 -------------------------
9244 -- Find_Type_Of_Object --
9245 -------------------------
9247 function Find_Type_Of_Object
9249 Related_Nod : Node_Id)
9252 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
9253 P : constant Node_Id := Parent (Obj_Def);
9258 -- Case of an anonymous array subtype
9260 if Def_Kind = N_Constrained_Array_Definition
9261 or else Def_Kind = N_Unconstrained_Array_Definition
9264 Array_Type_Declaration (T, Obj_Def);
9266 -- Create an explicit subtype whenever possible.
9268 elsif Nkind (P) /= N_Component_Declaration
9269 and then Def_Kind = N_Subtype_Indication
9271 -- Base name of subtype on object name, which will be unique in
9272 -- the current scope.
9274 -- If this is a duplicate declaration, return base type, to avoid
9275 -- generating duplicate anonymous types.
9277 if Error_Posted (P) then
9278 Analyze (Subtype_Mark (Obj_Def));
9279 return Entity (Subtype_Mark (Obj_Def));
9284 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
9286 T := Make_Defining_Identifier (Sloc (P), Nam);
9288 Insert_Action (Obj_Def,
9289 Make_Subtype_Declaration (Sloc (P),
9290 Defining_Identifier => T,
9291 Subtype_Indication => Relocate_Node (Obj_Def)));
9293 -- This subtype may need freezing and it will not be done
9294 -- automatically if the object declaration is not in a
9295 -- declarative part. Since this is an object declaration, the
9296 -- type cannot always be frozen here. Deferred constants do not
9297 -- freeze their type (which often enough will be private).
9299 if Nkind (P) = N_Object_Declaration
9300 and then Constant_Present (P)
9301 and then No (Expression (P))
9306 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
9310 T := Process_Subtype (Obj_Def, Related_Nod);
9314 end Find_Type_Of_Object;
9316 --------------------------------
9317 -- Find_Type_Of_Subtype_Indic --
9318 --------------------------------
9320 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
9324 -- Case of subtype mark with a constraint
9326 if Nkind (S) = N_Subtype_Indication then
9327 Find_Type (Subtype_Mark (S));
9328 Typ := Entity (Subtype_Mark (S));
9331 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
9334 ("incorrect constraint for this kind of type", Constraint (S));
9335 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
9338 -- Otherwise we have a subtype mark without a constraint
9340 elsif Error_Posted (S) then
9341 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
9349 if Typ = Standard_Wide_Character
9350 or else Typ = Standard_Wide_String
9352 Check_Restriction (No_Wide_Characters, S);
9356 end Find_Type_Of_Subtype_Indic;
9358 -------------------------------------
9359 -- Floating_Point_Type_Declaration --
9360 -------------------------------------
9362 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9363 Digs : constant Node_Id := Digits_Expression (Def);
9365 Base_Typ : Entity_Id;
9366 Implicit_Base : Entity_Id;
9369 function Can_Derive_From (E : Entity_Id) return Boolean;
9370 -- Find if given digits value allows derivation from specified type
9372 function Can_Derive_From (E : Entity_Id) return Boolean is
9373 Spec : constant Entity_Id := Real_Range_Specification (Def);
9376 if Digs_Val > Digits_Value (E) then
9380 if Present (Spec) then
9381 if Expr_Value_R (Type_Low_Bound (E)) >
9382 Expr_Value_R (Low_Bound (Spec))
9387 if Expr_Value_R (Type_High_Bound (E)) <
9388 Expr_Value_R (High_Bound (Spec))
9395 end Can_Derive_From;
9397 -- Start of processing for Floating_Point_Type_Declaration
9400 Check_Restriction (No_Floating_Point, Def);
9402 -- Create an implicit base type
9405 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
9407 -- Analyze and verify digits value
9409 Analyze_And_Resolve (Digs, Any_Integer);
9410 Check_Digits_Expression (Digs);
9411 Digs_Val := Expr_Value (Digs);
9413 -- Process possible range spec and find correct type to derive from
9415 Process_Real_Range_Specification (Def);
9417 if Can_Derive_From (Standard_Short_Float) then
9418 Base_Typ := Standard_Short_Float;
9419 elsif Can_Derive_From (Standard_Float) then
9420 Base_Typ := Standard_Float;
9421 elsif Can_Derive_From (Standard_Long_Float) then
9422 Base_Typ := Standard_Long_Float;
9423 elsif Can_Derive_From (Standard_Long_Long_Float) then
9424 Base_Typ := Standard_Long_Long_Float;
9426 -- If we can't derive from any existing type, use long long float
9427 -- and give appropriate message explaining the problem.
9430 Base_Typ := Standard_Long_Long_Float;
9432 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
9433 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
9434 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
9438 ("range too large for any predefined type",
9439 Real_Range_Specification (Def));
9443 -- If there are bounds given in the declaration use them as the bounds
9444 -- of the type, otherwise use the bounds of the predefined base type
9445 -- that was chosen based on the Digits value.
9447 if Present (Real_Range_Specification (Def)) then
9448 Set_Scalar_Range (T, Real_Range_Specification (Def));
9449 Set_Is_Constrained (T);
9451 -- The bounds of this range must be converted to machine numbers
9452 -- in accordance with RM 4.9(38).
9454 Bound := Type_Low_Bound (T);
9456 if Nkind (Bound) = N_Real_Literal then
9457 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9458 Set_Is_Machine_Number (Bound);
9461 Bound := Type_High_Bound (T);
9463 if Nkind (Bound) = N_Real_Literal then
9464 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9465 Set_Is_Machine_Number (Bound);
9469 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
9472 -- Complete definition of implicit base and declared first subtype
9474 Set_Etype (Implicit_Base, Base_Typ);
9476 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
9477 Set_Size_Info (Implicit_Base, (Base_Typ));
9478 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
9479 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
9480 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
9481 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
9483 Set_Ekind (T, E_Floating_Point_Subtype);
9484 Set_Etype (T, Implicit_Base);
9486 Set_Size_Info (T, (Implicit_Base));
9487 Set_RM_Size (T, RM_Size (Implicit_Base));
9488 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
9489 Set_Digits_Value (T, Digs_Val);
9491 end Floating_Point_Type_Declaration;
9493 ----------------------------
9494 -- Get_Discriminant_Value --
9495 ----------------------------
9497 -- This is the situation...
9499 -- There is a non-derived type
9501 -- type T0 (Dx, Dy, Dz...)
9503 -- There are zero or more levels of derivation, with each
9504 -- derivation either purely inheriting the discriminants, or
9505 -- defining its own.
9507 -- type Ti is new Ti-1
9509 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
9511 -- subtype Ti is ...
9513 -- The subtype issue is avoided by the use of
9514 -- Original_Record_Component, and the fact that derived subtypes
9515 -- also derive the constraits.
9517 -- This chain leads back from
9519 -- Typ_For_Constraint
9521 -- Typ_For_Constraint has discriminants, and the value for each
9522 -- discriminant is given by its corresponding Elmt of Constraints.
9524 -- Discriminant is some discriminant in this hierarchy.
9526 -- We need to return its value.
9528 -- We do this by recursively searching each level, and looking for
9529 -- Discriminant. Once we get to the bottom, we start backing up
9530 -- returning the value for it which may in turn be a discriminant
9531 -- further up, so on the backup we continue the substitution.
9533 function Get_Discriminant_Value
9534 (Discriminant : Entity_Id;
9535 Typ_For_Constraint : Entity_Id;
9536 Constraint : Elist_Id)
9541 Discrim_Values : Elist_Id;
9542 Girder_Discrim_Values : Boolean)
9543 return Node_Or_Entity_Id;
9544 -- This is the routine that performs the recursive search of levels
9545 -- as described above.
9549 Discrim_Values : Elist_Id;
9550 Girder_Discrim_Values : Boolean)
9551 return Node_Or_Entity_Id
9555 Result : Node_Or_Entity_Id;
9556 Result_Entity : Node_Id;
9559 -- If inappropriate type, return Error, this happens only in
9560 -- cascaded error situations, and we want to avoid a blow up.
9562 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
9566 -- Look deeper if possible. Use Girder_Constraints only for
9567 -- untagged types. For tagged types use the given constraint.
9568 -- This asymmetry needs explanation???
9570 if not Girder_Discrim_Values
9571 and then Present (Girder_Constraint (Ti))
9572 and then not Is_Tagged_Type (Ti)
9574 Result := Recurse (Ti, Girder_Constraint (Ti), True);
9577 Td : Entity_Id := Etype (Ti);
9581 Result := Discriminant;
9584 if Present (Girder_Constraint (Ti)) then
9586 Recurse (Td, Girder_Constraint (Ti), True);
9589 Recurse (Td, Discrim_Values, Girder_Discrim_Values);
9595 -- Extra underlying places to search, if not found above. For
9596 -- concurrent types, the relevant discriminant appears in the
9597 -- corresponding record. For a type derived from a private type
9598 -- without discriminant, the full view inherits the discriminants
9599 -- of the full view of the parent.
9601 if Result = Discriminant then
9602 if Is_Concurrent_Type (Ti)
9603 and then Present (Corresponding_Record_Type (Ti))
9607 Corresponding_Record_Type (Ti),
9609 Girder_Discrim_Values);
9611 elsif Is_Private_Type (Ti)
9612 and then not Has_Discriminants (Ti)
9613 and then Present (Full_View (Ti))
9614 and then Etype (Full_View (Ti)) /= Ti
9620 Girder_Discrim_Values);
9624 -- If Result is not a (reference to a) discriminant,
9625 -- return it, otherwise set Result_Entity to the discriminant.
9627 if Nkind (Result) = N_Defining_Identifier then
9629 pragma Assert (Result = Discriminant);
9631 Result_Entity := Result;
9634 if not Denotes_Discriminant (Result) then
9638 Result_Entity := Entity (Result);
9641 -- See if this level of derivation actually has discriminants
9642 -- because tagged derivations can add them, hence the lower
9643 -- levels need not have any.
9645 if not Has_Discriminants (Ti) then
9649 -- Scan Ti's discriminants for Result_Entity,
9650 -- and return its corresponding value, if any.
9652 Result_Entity := Original_Record_Component (Result_Entity);
9654 Assoc := First_Elmt (Discrim_Values);
9656 if Girder_Discrim_Values then
9657 Disc := First_Girder_Discriminant (Ti);
9659 Disc := First_Discriminant (Ti);
9662 while Present (Disc) loop
9664 pragma Assert (Present (Assoc));
9666 if Original_Record_Component (Disc) = Result_Entity then
9667 return Node (Assoc);
9672 if Girder_Discrim_Values then
9673 Next_Girder_Discriminant (Disc);
9675 Next_Discriminant (Disc);
9679 -- Could not find it
9684 Result : Node_Or_Entity_Id;
9686 -- Start of processing for Get_Discriminant_Value
9689 -- ??? this routine is a gigantic mess and will be deleted.
9690 -- for the time being just test for the trivial case before calling
9693 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
9695 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9696 E : Elmt_Id := First_Elmt (Constraint);
9698 while Present (D) loop
9699 if Chars (D) = Chars (Discriminant) then
9703 Next_Discriminant (D);
9709 Result := Recurse (Typ_For_Constraint, Constraint, False);
9711 -- ??? hack to disappear when this routine is gone
9713 if Nkind (Result) = N_Defining_Identifier then
9715 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9716 E : Elmt_Id := First_Elmt (Constraint);
9718 while Present (D) loop
9719 if Corresponding_Discriminant (D) = Discriminant then
9723 Next_Discriminant (D);
9729 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
9731 end Get_Discriminant_Value;
9733 --------------------------
9734 -- Has_Range_Constraint --
9735 --------------------------
9737 function Has_Range_Constraint (N : Node_Id) return Boolean is
9738 C : constant Node_Id := Constraint (N);
9741 if Nkind (C) = N_Range_Constraint then
9744 elsif Nkind (C) = N_Digits_Constraint then
9746 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
9748 Present (Range_Constraint (C));
9750 elsif Nkind (C) = N_Delta_Constraint then
9751 return Present (Range_Constraint (C));
9756 end Has_Range_Constraint;
9758 ------------------------
9759 -- Inherit_Components --
9760 ------------------------
9762 function Inherit_Components
9764 Parent_Base : Entity_Id;
9765 Derived_Base : Entity_Id;
9766 Is_Tagged : Boolean;
9767 Inherit_Discr : Boolean;
9771 Assoc_List : Elist_Id := New_Elmt_List;
9773 procedure Inherit_Component
9775 Plain_Discrim : Boolean := False;
9776 Girder_Discrim : Boolean := False);
9777 -- Inherits component Old_C from Parent_Base to the Derived_Base.
9778 -- If Plain_Discrim is True, Old_C is a discriminant.
9779 -- If Girder_Discrim is True, Old_C is a girder discriminant.
9780 -- If they are both false then Old_C is a regular component.
9782 -----------------------
9783 -- Inherit_Component --
9784 -----------------------
9786 procedure Inherit_Component
9788 Plain_Discrim : Boolean := False;
9789 Girder_Discrim : Boolean := False)
9791 New_C : Entity_Id := New_Copy (Old_C);
9793 Discrim : Entity_Id;
9794 Corr_Discrim : Entity_Id;
9797 pragma Assert (not Is_Tagged or else not Girder_Discrim);
9799 Set_Parent (New_C, Parent (Old_C));
9801 -- Regular discriminants and components must be inserted
9802 -- in the scope of the Derived_Base. Do it here.
9804 if not Girder_Discrim then
9808 -- For tagged types the Original_Record_Component must point to
9809 -- whatever this field was pointing to in the parent type. This has
9810 -- already been achieved by the call to New_Copy above.
9812 if not Is_Tagged then
9813 Set_Original_Record_Component (New_C, New_C);
9816 -- If we have inherited a component then see if its Etype contains
9817 -- references to Parent_Base discriminants. In this case, replace
9818 -- these references with the constraints given in Discs. We do not
9819 -- do this for the partial view of private types because this is
9820 -- not needed (only the components of the full view will be used
9821 -- for code generation) and cause problem. We also avoid this
9822 -- transformation in some error situations.
9824 if Ekind (New_C) = E_Component then
9825 if (Is_Private_Type (Derived_Base)
9826 and then not Is_Generic_Type (Derived_Base))
9827 or else (Is_Empty_Elmt_List (Discs)
9828 and then not Expander_Active)
9830 Set_Etype (New_C, Etype (Old_C));
9832 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
9833 Derived_Base, N, Parent_Base, Discs));
9837 -- In derived tagged types it is illegal to reference a non
9838 -- discriminant component in the parent type. To catch this, mark
9839 -- these components with an Ekind of E_Void. This will be reset in
9840 -- Record_Type_Definition after processing the record extension of
9841 -- the derived type.
9843 if Is_Tagged and then Ekind (New_C) = E_Component then
9844 Set_Ekind (New_C, E_Void);
9847 if Plain_Discrim then
9848 Set_Corresponding_Discriminant (New_C, Old_C);
9849 Build_Discriminal (New_C);
9851 -- If we are explicitely inheriting a girder discriminant it will be
9852 -- completely hidden.
9854 elsif Girder_Discrim then
9855 Set_Corresponding_Discriminant (New_C, Empty);
9856 Set_Discriminal (New_C, Empty);
9857 Set_Is_Completely_Hidden (New_C);
9859 -- Set the Original_Record_Component of each discriminant in the
9860 -- derived base to point to the corresponding girder that we just
9863 Discrim := First_Discriminant (Derived_Base);
9864 while Present (Discrim) loop
9865 Corr_Discrim := Corresponding_Discriminant (Discrim);
9867 -- Corr_Discrimm could be missing in an error situation.
9869 if Present (Corr_Discrim)
9870 and then Original_Record_Component (Corr_Discrim) = Old_C
9872 Set_Original_Record_Component (Discrim, New_C);
9875 Next_Discriminant (Discrim);
9878 Append_Entity (New_C, Derived_Base);
9881 if not Is_Tagged then
9882 Append_Elmt (Old_C, Assoc_List);
9883 Append_Elmt (New_C, Assoc_List);
9885 end Inherit_Component;
9887 -- Variables local to Inherit_Components.
9889 Loc : constant Source_Ptr := Sloc (N);
9891 Parent_Discrim : Entity_Id;
9892 Girder_Discrim : Entity_Id;
9895 Component : Entity_Id;
9897 -- Start of processing for Inherit_Components
9900 if not Is_Tagged then
9901 Append_Elmt (Parent_Base, Assoc_List);
9902 Append_Elmt (Derived_Base, Assoc_List);
9905 -- Inherit parent discriminants if needed.
9907 if Inherit_Discr then
9908 Parent_Discrim := First_Discriminant (Parent_Base);
9909 while Present (Parent_Discrim) loop
9910 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
9911 Next_Discriminant (Parent_Discrim);
9915 -- Create explicit girder discrims for untagged types when necessary.
9917 if not Has_Unknown_Discriminants (Derived_Base)
9918 and then Has_Discriminants (Parent_Base)
9919 and then not Is_Tagged
9922 or else First_Discriminant (Parent_Base) /=
9923 First_Girder_Discriminant (Parent_Base))
9925 Girder_Discrim := First_Girder_Discriminant (Parent_Base);
9926 while Present (Girder_Discrim) loop
9927 Inherit_Component (Girder_Discrim, Girder_Discrim => True);
9928 Next_Girder_Discriminant (Girder_Discrim);
9932 -- See if we can apply the second transformation for derived types, as
9933 -- explained in point 6. in the comments above Build_Derived_Record_Type
9934 -- This is achieved by appending Derived_Base discriminants into
9935 -- Discs, which has the side effect of returning a non empty Discs
9936 -- list to the caller of Inherit_Components, which is what we want.
9939 and then Is_Empty_Elmt_List (Discs)
9940 and then (not Is_Private_Type (Derived_Base)
9941 or Is_Generic_Type (Derived_Base))
9943 D := First_Discriminant (Derived_Base);
9944 while Present (D) loop
9945 Append_Elmt (New_Reference_To (D, Loc), Discs);
9946 Next_Discriminant (D);
9950 -- Finally, inherit non-discriminant components unless they are not
9951 -- visible because defined or inherited from the full view of the
9952 -- parent. Don't inherit the _parent field of the parent type.
9954 Component := First_Entity (Parent_Base);
9955 while Present (Component) loop
9956 if Ekind (Component) /= E_Component
9957 or else Chars (Component) = Name_uParent
9961 -- If the derived type is within the parent type's declarative
9962 -- region, then the components can still be inherited even though
9963 -- they aren't visible at this point. This can occur for cases
9964 -- such as within public child units where the components must
9965 -- become visible upon entering the child unit's private part.
9967 elsif not Is_Visible_Component (Component)
9968 and then not In_Open_Scopes (Scope (Parent_Base))
9972 elsif Ekind (Derived_Base) = E_Private_Type
9973 or else Ekind (Derived_Base) = E_Limited_Private_Type
9978 Inherit_Component (Component);
9981 Next_Entity (Component);
9984 -- For tagged derived types, inherited discriminants cannot be used in
9985 -- component declarations of the record extension part. To achieve this
9986 -- we mark the inherited discriminants as not visible.
9988 if Is_Tagged and then Inherit_Discr then
9989 D := First_Discriminant (Derived_Base);
9990 while Present (D) loop
9991 Set_Is_Immediately_Visible (D, False);
9992 Next_Discriminant (D);
9997 end Inherit_Components;
9999 ------------------------------
10000 -- Is_Valid_Constraint_Kind --
10001 ------------------------------
10003 function Is_Valid_Constraint_Kind
10004 (T_Kind : Type_Kind;
10005 Constraint_Kind : Node_Kind)
10011 when Enumeration_Kind |
10013 return Constraint_Kind = N_Range_Constraint;
10015 when Decimal_Fixed_Point_Kind =>
10017 Constraint_Kind = N_Digits_Constraint
10019 Constraint_Kind = N_Range_Constraint;
10021 when Ordinary_Fixed_Point_Kind =>
10023 Constraint_Kind = N_Delta_Constraint
10025 Constraint_Kind = N_Range_Constraint;
10029 Constraint_Kind = N_Digits_Constraint
10031 Constraint_Kind = N_Range_Constraint;
10038 E_Incomplete_Type |
10041 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
10044 return True; -- Error will be detected later.
10047 end Is_Valid_Constraint_Kind;
10049 --------------------------
10050 -- Is_Visible_Component --
10051 --------------------------
10053 function Is_Visible_Component (C : Entity_Id) return Boolean is
10054 Original_Comp : constant Entity_Id := Original_Record_Component (C);
10055 Original_Scope : Entity_Id;
10058 if No (Original_Comp) then
10060 -- Premature usage, or previous error
10065 Original_Scope := Scope (Original_Comp);
10068 -- This test only concern tagged types
10070 if not Is_Tagged_Type (Original_Scope) then
10073 -- If it is _Parent or _Tag, there is no visiblity issue
10075 elsif not Comes_From_Source (Original_Comp) then
10078 -- If we are in the body of an instantiation, the component is
10079 -- visible even when the parent type (possibly defined in an
10080 -- enclosing unit or in a parent unit) might not.
10082 elsif In_Instance_Body then
10085 -- Discriminants are always visible.
10087 elsif Ekind (Original_Comp) = E_Discriminant
10088 and then not Has_Unknown_Discriminants (Original_Scope)
10092 -- If the component has been declared in an ancestor which is
10093 -- currently a private type, then it is not visible. The same
10094 -- applies if the component's containing type is not in an
10095 -- open scope and the original component's enclosing type
10096 -- is a visible full type of a private type (which can occur
10097 -- in cases where an attempt is being made to reference a
10098 -- component in a sibling package that is inherited from
10099 -- a visible component of a type in an ancestor package;
10100 -- the component in the sibling package should not be
10101 -- visible even though the component it inherited from
10102 -- is visible). This does not apply however in the case
10103 -- where the scope of the type is a private child unit.
10104 -- The latter suppression of visibility is needed for cases
10105 -- that are tested in B730006.
10107 elsif (Ekind (Original_Comp) /= E_Discriminant
10108 or else Has_Unknown_Discriminants (Original_Scope))
10110 (Is_Private_Type (Original_Scope)
10112 (not Is_Private_Descendant (Scope (Base_Type (Scope (C))))
10113 and then not In_Open_Scopes (Scope (Base_Type (Scope (C))))
10114 and then Has_Private_Declaration (Original_Scope)))
10118 -- There is another weird way in which a component may be invisible
10119 -- when the private and the full view are not derived from the same
10120 -- ancestor. Here is an example :
10122 -- type A1 is tagged record F1 : integer; end record;
10123 -- type A2 is new A1 with record F2 : integer; end record;
10124 -- type T is new A1 with private;
10126 -- type T is new A2 with private;
10128 -- In this case, the full view of T inherits F1 and F2 but the
10129 -- private view inherits only F1
10133 Ancestor : Entity_Id := Scope (C);
10137 if Ancestor = Original_Scope then
10139 elsif Ancestor = Etype (Ancestor) then
10143 Ancestor := Etype (Ancestor);
10149 end Is_Visible_Component;
10151 --------------------------
10152 -- Make_Class_Wide_Type --
10153 --------------------------
10155 procedure Make_Class_Wide_Type (T : Entity_Id) is
10156 CW_Type : Entity_Id;
10158 Next_E : Entity_Id;
10161 -- The class wide type can have been defined by the partial view in
10162 -- which case everything is already done
10164 if Present (Class_Wide_Type (T)) then
10169 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
10171 -- Inherit root type characteristics
10173 CW_Name := Chars (CW_Type);
10174 Next_E := Next_Entity (CW_Type);
10175 Copy_Node (T, CW_Type);
10176 Set_Comes_From_Source (CW_Type, False);
10177 Set_Chars (CW_Type, CW_Name);
10178 Set_Parent (CW_Type, Parent (T));
10179 Set_Next_Entity (CW_Type, Next_E);
10180 Set_Has_Delayed_Freeze (CW_Type);
10182 -- Customize the class-wide type: It has no prim. op., it cannot be
10183 -- abstract and its Etype points back to the root type
10185 Set_Ekind (CW_Type, E_Class_Wide_Type);
10186 Set_Is_Tagged_Type (CW_Type, True);
10187 Set_Primitive_Operations (CW_Type, New_Elmt_List);
10188 Set_Is_Abstract (CW_Type, False);
10189 Set_Etype (CW_Type, T);
10190 Set_Is_Constrained (CW_Type, False);
10191 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
10192 Init_Size_Align (CW_Type);
10194 -- If this is the class_wide type of a constrained subtype, it does
10195 -- not have discriminants.
10197 Set_Has_Discriminants (CW_Type,
10198 Has_Discriminants (T) and then not Is_Constrained (T));
10200 Set_Has_Unknown_Discriminants (CW_Type, True);
10201 Set_Class_Wide_Type (T, CW_Type);
10202 Set_Equivalent_Type (CW_Type, Empty);
10204 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
10206 Set_Class_Wide_Type (CW_Type, CW_Type);
10208 end Make_Class_Wide_Type;
10214 procedure Make_Index
10216 Related_Nod : Node_Id;
10217 Related_Id : Entity_Id := Empty;
10218 Suffix_Index : Nat := 1)
10222 Def_Id : Entity_Id := Empty;
10223 Found : Boolean := False;
10226 -- For a discrete range used in a constrained array definition and
10227 -- defined by a range, an implicit conversion to the predefined type
10228 -- INTEGER is assumed if each bound is either a numeric literal, a named
10229 -- number, or an attribute, and the type of both bounds (prior to the
10230 -- implicit conversion) is the type universal_integer. Otherwise, both
10231 -- bounds must be of the same discrete type, other than universal
10232 -- integer; this type must be determinable independently of the
10233 -- context, but using the fact that the type must be discrete and that
10234 -- both bounds must have the same type.
10236 -- Character literals also have a universal type in the absence of
10237 -- of additional context, and are resolved to Standard_Character.
10239 if Nkind (I) = N_Range then
10241 -- The index is given by a range constraint. The bounds are known
10242 -- to be of a consistent type.
10244 if not Is_Overloaded (I) then
10247 -- If the bounds are universal, choose the specific predefined
10250 if T = Universal_Integer then
10251 T := Standard_Integer;
10253 elsif T = Any_Character then
10257 ("ambiguous character literals (could be Wide_Character)",
10261 T := Standard_Character;
10268 Ind : Interp_Index;
10272 Get_First_Interp (I, Ind, It);
10274 while Present (It.Typ) loop
10275 if Is_Discrete_Type (It.Typ) then
10278 and then not Covers (It.Typ, T)
10279 and then not Covers (T, It.Typ)
10281 Error_Msg_N ("ambiguous bounds in discrete range", I);
10289 Get_Next_Interp (Ind, It);
10292 if T = Any_Type then
10293 Error_Msg_N ("discrete type required for range", I);
10294 Set_Etype (I, Any_Type);
10297 elsif T = Universal_Integer then
10298 T := Standard_Integer;
10303 if not Is_Discrete_Type (T) then
10304 Error_Msg_N ("discrete type required for range", I);
10305 Set_Etype (I, Any_Type);
10310 Process_Range_Expr_In_Decl (R, T, Related_Nod);
10312 elsif Nkind (I) = N_Subtype_Indication then
10314 -- The index is given by a subtype with a range constraint.
10316 T := Base_Type (Entity (Subtype_Mark (I)));
10318 if not Is_Discrete_Type (T) then
10319 Error_Msg_N ("discrete type required for range", I);
10320 Set_Etype (I, Any_Type);
10324 R := Range_Expression (Constraint (I));
10327 Process_Range_Expr_In_Decl (R,
10328 Entity (Subtype_Mark (I)), Related_Nod);
10330 elsif Nkind (I) = N_Attribute_Reference then
10332 -- The parser guarantees that the attribute is a RANGE attribute
10334 -- Is order critical here (setting T before Resolve). If so,
10335 -- document why, if not use Analyze_And_Resolve and get T after???
10342 -- If none of the above, must be a subtype. We convert this to a
10343 -- range attribute reference because in the case of declared first
10344 -- named subtypes, the types in the range reference can be different
10345 -- from the type of the entity. A range attribute normalizes the
10346 -- reference and obtains the correct types for the bounds.
10348 -- This transformation is in the nature of an expansion, is only
10349 -- done if expansion is active. In particular, it is not done on
10350 -- formal generic types, because we need to retain the name of the
10351 -- original index for instantiation purposes.
10354 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
10355 Error_Msg_N ("invalid subtype mark in discrete range ", I);
10356 Set_Etype (I, Any_Integer);
10359 -- The type mark may be that of an incomplete type. It is only
10360 -- now that we can get the full view, previous analysis does
10361 -- not look specifically for a type mark.
10363 Set_Entity (I, Get_Full_View (Entity (I)));
10364 Set_Etype (I, Entity (I));
10365 Def_Id := Entity (I);
10367 if not Is_Discrete_Type (Def_Id) then
10368 Error_Msg_N ("discrete type required for index", I);
10369 Set_Etype (I, Any_Type);
10374 if Expander_Active then
10376 Make_Attribute_Reference (Sloc (I),
10377 Attribute_Name => Name_Range,
10378 Prefix => Relocate_Node (I)));
10380 -- The original was a subtype mark that does not freeze. This
10381 -- means that the rewritten version must not freeze either.
10383 Set_Must_Not_Freeze (I);
10384 Set_Must_Not_Freeze (Prefix (I));
10386 -- Is order critical??? if so, document why, if not
10387 -- use Analyze_And_Resolve
10395 -- Type is legal, nothing else to construct.
10400 if not Is_Discrete_Type (T) then
10401 Error_Msg_N ("discrete type required for range", I);
10402 Set_Etype (I, Any_Type);
10405 elsif T = Any_Type then
10406 Set_Etype (I, Any_Type);
10410 -- We will now create the appropriate Itype to describe the
10411 -- range, but first a check. If we originally had a subtype,
10412 -- then we just label the range with this subtype. Not only
10413 -- is there no need to construct a new subtype, but it is wrong
10414 -- to do so for two reasons:
10416 -- 1. A legality concern, if we have a subtype, it must not
10417 -- freeze, and the Itype would cause freezing incorrectly
10419 -- 2. An efficiency concern, if we created an Itype, it would
10420 -- not be recognized as the same type for the purposes of
10421 -- eliminating checks in some circumstances.
10423 -- We signal this case by setting the subtype entity in Def_Id.
10425 -- It would be nice to also do this optimization for the cases
10426 -- of X'Range and also the explicit range X'First .. X'Last,
10427 -- but that is not done yet (it is just an efficiency concern) ???
10429 if No (Def_Id) then
10432 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
10433 Set_Etype (Def_Id, Base_Type (T));
10435 if Is_Signed_Integer_Type (T) then
10436 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
10438 elsif Is_Modular_Integer_Type (T) then
10439 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
10442 Set_Ekind (Def_Id, E_Enumeration_Subtype);
10443 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
10446 Set_Size_Info (Def_Id, (T));
10447 Set_RM_Size (Def_Id, RM_Size (T));
10448 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10450 Set_Scalar_Range (Def_Id, R);
10451 Conditional_Delay (Def_Id, T);
10453 -- In the subtype indication case, if the immediate parent of the
10454 -- new subtype is non-static, then the subtype we create is non-
10455 -- static, even if its bounds are static.
10457 if Nkind (I) = N_Subtype_Indication
10458 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
10460 Set_Is_Non_Static_Subtype (Def_Id);
10464 -- Final step is to label the index with this constructed type
10466 Set_Etype (I, Def_Id);
10469 ------------------------------
10470 -- Modular_Type_Declaration --
10471 ------------------------------
10473 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10474 Mod_Expr : constant Node_Id := Expression (Def);
10477 procedure Set_Modular_Size (Bits : Int);
10478 -- Sets RM_Size to Bits, and Esize to normal word size above this
10480 procedure Set_Modular_Size (Bits : Int) is
10482 Set_RM_Size (T, UI_From_Int (Bits));
10487 elsif Bits <= 16 then
10488 Init_Esize (T, 16);
10490 elsif Bits <= 32 then
10491 Init_Esize (T, 32);
10494 Init_Esize (T, System_Max_Binary_Modulus_Power);
10496 end Set_Modular_Size;
10498 -- Start of processing for Modular_Type_Declaration
10501 Analyze_And_Resolve (Mod_Expr, Any_Integer);
10503 Set_Ekind (T, E_Modular_Integer_Type);
10504 Init_Alignment (T);
10505 Set_Is_Constrained (T);
10507 if not Is_OK_Static_Expression (Mod_Expr) then
10509 ("non-static expression used for modular type bound", Mod_Expr);
10510 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10512 M_Val := Expr_Value (Mod_Expr);
10516 Error_Msg_N ("modulus value must be positive", Mod_Expr);
10517 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10520 Set_Modulus (T, M_Val);
10522 -- Create bounds for the modular type based on the modulus given in
10523 -- the type declaration and then analyze and resolve those bounds.
10525 Set_Scalar_Range (T,
10526 Make_Range (Sloc (Mod_Expr),
10528 Make_Integer_Literal (Sloc (Mod_Expr), 0),
10530 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
10532 -- Properly analyze the literals for the range. We do this manually
10533 -- because we can't go calling Resolve, since we are resolving these
10534 -- bounds with the type, and this type is certainly not complete yet!
10536 Set_Etype (Low_Bound (Scalar_Range (T)), T);
10537 Set_Etype (High_Bound (Scalar_Range (T)), T);
10538 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
10539 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
10541 -- Loop through powers of two to find number of bits required
10543 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
10547 if M_Val = 2 ** Bits then
10548 Set_Modular_Size (Bits);
10553 elsif M_Val < 2 ** Bits then
10554 Set_Non_Binary_Modulus (T);
10556 if Bits > System_Max_Nonbinary_Modulus_Power then
10557 Error_Msg_Uint_1 :=
10558 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
10560 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
10561 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10565 -- In the non-binary case, set size as per RM 13.3(55).
10567 Set_Modular_Size (Bits);
10574 -- If we fall through, then the size exceed System.Max_Binary_Modulus
10575 -- so we just signal an error and set the maximum size.
10577 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
10578 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
10580 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10581 Init_Alignment (T);
10583 end Modular_Type_Declaration;
10585 -------------------------
10586 -- New_Binary_Operator --
10587 -------------------------
10589 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id) is
10590 Loc : constant Source_Ptr := Sloc (Typ);
10593 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
10594 -- Create abbreviated declaration for the formal of a predefined
10595 -- Operator 'Op' of type 'Typ'
10597 --------------------
10598 -- Make_Op_Formal --
10599 --------------------
10601 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
10602 Formal : Entity_Id;
10605 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
10606 Set_Etype (Formal, Typ);
10607 Set_Mechanism (Formal, Default_Mechanism);
10609 end Make_Op_Formal;
10611 -- Start of processing for New_Binary_Operator
10614 Op := Make_Defining_Operator_Symbol (Loc, Op_Name);
10616 Set_Ekind (Op, E_Operator);
10617 Set_Scope (Op, Current_Scope);
10618 Set_Etype (Op, Typ);
10619 Set_Homonym (Op, Get_Name_Entity_Id (Op_Name));
10620 Set_Is_Immediately_Visible (Op);
10621 Set_Is_Intrinsic_Subprogram (Op);
10622 Set_Has_Completion (Op);
10623 Append_Entity (Op, Current_Scope);
10625 Set_Name_Entity_Id (Op_Name, Op);
10627 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10628 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10630 end New_Binary_Operator;
10632 -------------------------------------------
10633 -- Ordinary_Fixed_Point_Type_Declaration --
10634 -------------------------------------------
10636 procedure Ordinary_Fixed_Point_Type_Declaration
10640 Loc : constant Source_Ptr := Sloc (Def);
10641 Delta_Expr : constant Node_Id := Delta_Expression (Def);
10642 RRS : constant Node_Id := Real_Range_Specification (Def);
10643 Implicit_Base : Entity_Id;
10650 Check_Restriction (No_Fixed_Point, Def);
10652 -- Create implicit base type
10655 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
10656 Set_Etype (Implicit_Base, Implicit_Base);
10658 -- Analyze and process delta expression
10660 Analyze_And_Resolve (Delta_Expr, Any_Real);
10662 Check_Delta_Expression (Delta_Expr);
10663 Delta_Val := Expr_Value_R (Delta_Expr);
10665 Set_Delta_Value (Implicit_Base, Delta_Val);
10667 -- Compute default small from given delta, which is the largest
10668 -- power of two that does not exceed the given delta value.
10671 Tmp : Ureal := Ureal_1;
10675 if Delta_Val < Ureal_1 then
10676 while Delta_Val < Tmp loop
10677 Tmp := Tmp / Ureal_2;
10678 Scale := Scale + 1;
10683 Tmp := Tmp * Ureal_2;
10684 exit when Tmp > Delta_Val;
10685 Scale := Scale - 1;
10689 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
10692 Set_Small_Value (Implicit_Base, Small_Val);
10694 -- If no range was given, set a dummy range
10696 if RRS <= Empty_Or_Error then
10697 Low_Val := -Small_Val;
10698 High_Val := Small_Val;
10700 -- Otherwise analyze and process given range
10704 Low : constant Node_Id := Low_Bound (RRS);
10705 High : constant Node_Id := High_Bound (RRS);
10708 Analyze_And_Resolve (Low, Any_Real);
10709 Analyze_And_Resolve (High, Any_Real);
10710 Check_Real_Bound (Low);
10711 Check_Real_Bound (High);
10713 -- Obtain and set the range
10715 Low_Val := Expr_Value_R (Low);
10716 High_Val := Expr_Value_R (High);
10718 if Low_Val > High_Val then
10719 Error_Msg_NE ("?fixed point type& has null range", Def, T);
10724 -- The range for both the implicit base and the declared first
10725 -- subtype cannot be set yet, so we use the special routine
10726 -- Set_Fixed_Range to set a temporary range in place. Note that
10727 -- the bounds of the base type will be widened to be symmetrical
10728 -- and to fill the available bits when the type is frozen.
10730 -- We could do this with all discrete types, and probably should, but
10731 -- we absolutely have to do it for fixed-point, since the end-points
10732 -- of the range and the size are determined by the small value, which
10733 -- could be reset before the freeze point.
10735 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
10736 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
10738 Init_Size_Align (Implicit_Base);
10740 -- Complete definition of first subtype
10742 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
10743 Set_Etype (T, Implicit_Base);
10744 Init_Size_Align (T);
10745 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
10746 Set_Small_Value (T, Small_Val);
10747 Set_Delta_Value (T, Delta_Val);
10748 Set_Is_Constrained (T);
10750 end Ordinary_Fixed_Point_Type_Declaration;
10752 ----------------------------------------
10753 -- Prepare_Private_Subtype_Completion --
10754 ----------------------------------------
10756 procedure Prepare_Private_Subtype_Completion
10758 Related_Nod : Node_Id)
10760 Id_B : constant Entity_Id := Base_Type (Id);
10761 Full_B : constant Entity_Id := Full_View (Id_B);
10765 if Present (Full_B) then
10767 -- The Base_Type is already completed, we can complete the
10768 -- subtype now. We have to create a new entity with the same name,
10769 -- Thus we can't use Create_Itype.
10770 -- This is messy, should be fixed ???
10772 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
10773 Set_Is_Itype (Full);
10774 Set_Associated_Node_For_Itype (Full, Related_Nod);
10775 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
10778 -- The parent subtype may be private, but the base might not, in some
10779 -- nested instances. In that case, the subtype does not need to be
10780 -- exchanged. It would still be nice to make private subtypes and their
10781 -- bases consistent at all times ???
10783 if Is_Private_Type (Id_B) then
10784 Append_Elmt (Id, Private_Dependents (Id_B));
10787 end Prepare_Private_Subtype_Completion;
10789 ---------------------------
10790 -- Process_Discriminants --
10791 ---------------------------
10793 procedure Process_Discriminants (N : Node_Id) is
10796 Discr_Number : Uint;
10797 Discr_Type : Entity_Id;
10798 Default_Present : Boolean := False;
10799 Default_Not_Present : Boolean := False;
10800 Elist : Elist_Id := New_Elmt_List;
10803 -- A composite type other than an array type can have discriminants.
10804 -- Discriminants of non-limited types must have a discrete type.
10805 -- On entry, the current scope is the composite type.
10807 -- The discriminants are initially entered into the scope of the type
10808 -- via Enter_Name with the default Ekind of E_Void to prevent premature
10809 -- use, as explained at the end of this procedure.
10811 Discr := First (Discriminant_Specifications (N));
10812 while Present (Discr) loop
10813 Enter_Name (Defining_Identifier (Discr));
10815 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
10816 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
10819 Find_Type (Discriminant_Type (Discr));
10820 Discr_Type := Etype (Discriminant_Type (Discr));
10822 if Error_Posted (Discriminant_Type (Discr)) then
10823 Discr_Type := Any_Type;
10827 if Is_Access_Type (Discr_Type) then
10828 Check_Access_Discriminant_Requires_Limited
10829 (Discr, Discriminant_Type (Discr));
10831 if Ada_83 and then Comes_From_Source (Discr) then
10833 ("(Ada 83) access discriminant not allowed", Discr);
10836 elsif not Is_Discrete_Type (Discr_Type) then
10837 Error_Msg_N ("discriminants must have a discrete or access type",
10838 Discriminant_Type (Discr));
10841 Set_Etype (Defining_Identifier (Discr), Discr_Type);
10843 -- If a discriminant specification includes the assignment compound
10844 -- delimiter followed by an expression, the expression is the default
10845 -- expression of the discriminant; the default expression must be of
10846 -- the type of the discriminant. (RM 3.7.1) Since this expression is
10847 -- a default expression, we do the special preanalysis, since this
10848 -- expression does not freeze (see "Handling of Default Expressions"
10849 -- in spec of package Sem).
10851 if Present (Expression (Discr)) then
10852 Analyze_Default_Expression (Expression (Discr), Discr_Type);
10854 if Nkind (N) = N_Formal_Type_Declaration then
10856 ("discriminant defaults not allowed for formal type",
10857 Expression (Discr));
10859 elsif Is_Tagged_Type (Current_Scope) then
10861 ("discriminants of tagged type cannot have defaults",
10862 Expression (Discr));
10865 Default_Present := True;
10866 Append_Elmt (Expression (Discr), Elist);
10868 -- Tag the defining identifiers for the discriminants with
10869 -- their corresponding default expressions from the tree.
10871 Set_Discriminant_Default_Value
10872 (Defining_Identifier (Discr), Expression (Discr));
10876 Default_Not_Present := True;
10882 -- An element list consisting of the default expressions of the
10883 -- discriminants is constructed in the above loop and used to set
10884 -- the Discriminant_Constraint attribute for the type. If an object
10885 -- is declared of this (record or task) type without any explicit
10886 -- discriminant constraint given, this element list will form the
10887 -- actual parameters for the corresponding initialization procedure
10890 Set_Discriminant_Constraint (Current_Scope, Elist);
10891 Set_Girder_Constraint (Current_Scope, No_Elist);
10893 -- Default expressions must be provided either for all or for none
10894 -- of the discriminants of a discriminant part. (RM 3.7.1)
10896 if Default_Present and then Default_Not_Present then
10898 ("incomplete specification of defaults for discriminants", N);
10901 -- The use of the name of a discriminant is not allowed in default
10902 -- expressions of a discriminant part if the specification of the
10903 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
10905 -- To detect this, the discriminant names are entered initially with an
10906 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
10907 -- attempt to use a void entity (for example in an expression that is
10908 -- type-checked) produces the error message: premature usage. Now after
10909 -- completing the semantic analysis of the discriminant part, we can set
10910 -- the Ekind of all the discriminants appropriately.
10912 Discr := First (Discriminant_Specifications (N));
10913 Discr_Number := Uint_1;
10915 while Present (Discr) loop
10916 Id := Defining_Identifier (Discr);
10917 Set_Ekind (Id, E_Discriminant);
10918 Init_Component_Location (Id);
10920 Set_Discriminant_Number (Id, Discr_Number);
10922 -- Make sure this is always set, even in illegal programs
10924 Set_Corresponding_Discriminant (Id, Empty);
10926 -- Initialize the Original_Record_Component to the entity itself.
10927 -- Inherit_Components will propagate the right value to
10928 -- discriminants in derived record types.
10930 Set_Original_Record_Component (Id, Id);
10932 -- Create the discriminal for the discriminant.
10934 Build_Discriminal (Id);
10937 Discr_Number := Discr_Number + 1;
10940 Set_Has_Discriminants (Current_Scope);
10941 end Process_Discriminants;
10943 -----------------------
10944 -- Process_Full_View --
10945 -----------------------
10947 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
10948 Priv_Parent : Entity_Id;
10949 Full_Parent : Entity_Id;
10950 Full_Indic : Node_Id;
10953 -- First some sanity checks that must be done after semantic
10954 -- decoration of the full view and thus cannot be placed with other
10955 -- similar checks in Find_Type_Name
10957 if not Is_Limited_Type (Priv_T)
10958 and then (Is_Limited_Type (Full_T)
10959 or else Is_Limited_Composite (Full_T))
10962 ("completion of nonlimited type cannot be limited", Full_T);
10964 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
10966 ("completion of nonabstract type cannot be abstract", Full_T);
10968 elsif Is_Tagged_Type (Priv_T)
10969 and then Is_Limited_Type (Priv_T)
10970 and then not Is_Limited_Type (Full_T)
10972 -- GNAT allow its own definition of Limited_Controlled to disobey
10973 -- this rule in order in ease the implementation. The next test is
10974 -- safe because Root_Controlled is defined in a private system child
10976 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
10977 Set_Is_Limited_Composite (Full_T);
10980 ("completion of limited tagged type must be limited", Full_T);
10983 elsif Is_Generic_Type (Priv_T) then
10984 Error_Msg_N ("generic type cannot have a completion", Full_T);
10987 if Is_Tagged_Type (Priv_T)
10988 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
10989 and then Is_Derived_Type (Full_T)
10991 Priv_Parent := Etype (Priv_T);
10993 -- The full view of a private extension may have been transformed
10994 -- into an unconstrained derived type declaration and a subtype
10995 -- declaration (see build_derived_record_type for details).
10997 if Nkind (N) = N_Subtype_Declaration then
10998 Full_Indic := Subtype_Indication (N);
10999 Full_Parent := Etype (Base_Type (Full_T));
11001 Full_Indic := Subtype_Indication (Type_Definition (N));
11002 Full_Parent := Etype (Full_T);
11005 -- Check that the parent type of the full type is a descendant of
11006 -- the ancestor subtype given in the private extension. If either
11007 -- entity has an Etype equal to Any_Type then we had some previous
11008 -- error situation [7.3(8)].
11010 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
11013 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
11015 ("parent of full type must descend from parent"
11016 & " of private extension", Full_Indic);
11018 -- Check the rules of 7.3(10): if the private extension inherits
11019 -- known discriminants, then the full type must also inherit those
11020 -- discriminants from the same (ancestor) type, and the parent
11021 -- subtype of the full type must be constrained if and only if
11022 -- the ancestor subtype of the private extension is constrained.
11024 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
11025 and then not Has_Unknown_Discriminants (Priv_T)
11026 and then Has_Discriminants (Base_Type (Priv_Parent))
11029 Priv_Indic : constant Node_Id :=
11030 Subtype_Indication (Parent (Priv_T));
11032 Priv_Constr : constant Boolean :=
11033 Is_Constrained (Priv_Parent)
11035 Nkind (Priv_Indic) = N_Subtype_Indication
11036 or else Is_Constrained (Entity (Priv_Indic));
11038 Full_Constr : constant Boolean :=
11039 Is_Constrained (Full_Parent)
11041 Nkind (Full_Indic) = N_Subtype_Indication
11042 or else Is_Constrained (Entity (Full_Indic));
11044 Priv_Discr : Entity_Id;
11045 Full_Discr : Entity_Id;
11048 Priv_Discr := First_Discriminant (Priv_Parent);
11049 Full_Discr := First_Discriminant (Full_Parent);
11051 while Present (Priv_Discr) and then Present (Full_Discr) loop
11052 if Original_Record_Component (Priv_Discr) =
11053 Original_Record_Component (Full_Discr)
11055 Corresponding_Discriminant (Priv_Discr) =
11056 Corresponding_Discriminant (Full_Discr)
11063 Next_Discriminant (Priv_Discr);
11064 Next_Discriminant (Full_Discr);
11067 if Present (Priv_Discr) or else Present (Full_Discr) then
11069 ("full view must inherit discriminants of the parent type"
11070 & " used in the private extension", Full_Indic);
11072 elsif Priv_Constr and then not Full_Constr then
11074 ("parent subtype of full type must be constrained",
11077 elsif Full_Constr and then not Priv_Constr then
11079 ("parent subtype of full type must be unconstrained",
11084 -- Check the rules of 7.3(12): if a partial view has neither known
11085 -- or unknown discriminants, then the full type declaration shall
11086 -- define a definite subtype.
11088 elsif not Has_Unknown_Discriminants (Priv_T)
11089 and then not Has_Discriminants (Priv_T)
11090 and then not Is_Constrained (Full_T)
11093 ("full view must define a constrained type if partial view"
11094 & " has no discriminants", Full_T);
11097 -- ??????? Do we implement the following properly ?????
11098 -- If the ancestor subtype of a private extension has constrained
11099 -- discriminants, then the parent subtype of the full view shall
11100 -- impose a statically matching constraint on those discriminants
11104 -- For untagged types, verify that a type without discriminants
11105 -- is not completed with an unconstrained type.
11107 if not Is_Indefinite_Subtype (Priv_T)
11108 and then Is_Indefinite_Subtype (Full_T)
11110 Error_Msg_N ("full view of type must be definite subtype", Full_T);
11114 -- Create a full declaration for all its subtypes recorded in
11115 -- Private_Dependents and swap them similarly to the base type.
11116 -- These are subtypes that have been define before the full
11117 -- declaration of the private type. We also swap the entry in
11118 -- Private_Dependents list so we can properly restore the
11119 -- private view on exit from the scope.
11122 Priv_Elmt : Elmt_Id;
11127 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
11128 while Present (Priv_Elmt) loop
11129 Priv := Node (Priv_Elmt);
11131 if Ekind (Priv) = E_Private_Subtype
11132 or else Ekind (Priv) = E_Limited_Private_Subtype
11133 or else Ekind (Priv) = E_Record_Subtype_With_Private
11135 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
11136 Set_Is_Itype (Full);
11137 Set_Parent (Full, Parent (Priv));
11138 Set_Associated_Node_For_Itype (Full, N);
11140 -- Now we need to complete the private subtype, but since the
11141 -- base type has already been swapped, we must also swap the
11142 -- subtypes (and thus, reverse the arguments in the call to
11143 -- Complete_Private_Subtype).
11145 Copy_And_Swap (Priv, Full);
11146 Complete_Private_Subtype (Full, Priv, Full_T, N);
11147 Replace_Elmt (Priv_Elmt, Full);
11150 Next_Elmt (Priv_Elmt);
11154 -- If the private view was tagged, copy the new Primitive
11155 -- operations from the private view to the full view.
11157 if Is_Tagged_Type (Full_T) then
11159 Priv_List : Elist_Id;
11160 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
11163 D_Type : Entity_Id;
11166 if Is_Tagged_Type (Priv_T) then
11167 Priv_List := Primitive_Operations (Priv_T);
11169 P1 := First_Elmt (Priv_List);
11170 while Present (P1) loop
11173 -- Transfer explicit primitives, not those inherited from
11174 -- parent of partial view, which will be re-inherited on
11177 if Comes_From_Source (Prim) then
11178 P2 := First_Elmt (Full_List);
11179 while Present (P2) and then Node (P2) /= Prim loop
11183 -- If not found, that is a new one
11186 Append_Elmt (Prim, Full_List);
11194 -- In this case the partial view is untagged, so here we
11195 -- locate all of the earlier primitives that need to be
11196 -- treated as dispatching (those that appear between the
11197 -- two views). Note that these additional operations must
11198 -- all be new operations (any earlier operations that
11199 -- override inherited operations of the full view will
11200 -- already have been inserted in the primitives list and
11201 -- marked as dispatching by Check_Operation_From_Private_View.
11202 -- Note that implicit "/=" operators are excluded from being
11203 -- added to the primitives list since they shouldn't be
11204 -- treated as dispatching (tagged "/=" is handled specially).
11206 Prim := Next_Entity (Full_T);
11207 while Present (Prim) and then Prim /= Priv_T loop
11208 if (Ekind (Prim) = E_Procedure
11209 or else Ekind (Prim) = E_Function)
11212 D_Type := Find_Dispatching_Type (Prim);
11215 and then (Chars (Prim) /= Name_Op_Ne
11216 or else Comes_From_Source (Prim))
11218 Check_Controlling_Formals (Full_T, Prim);
11220 if not Is_Dispatching_Operation (Prim) then
11221 Append_Elmt (Prim, Full_List);
11222 Set_Is_Dispatching_Operation (Prim, True);
11223 Set_DT_Position (Prim, No_Uint);
11226 elsif Is_Dispatching_Operation (Prim)
11227 and then D_Type /= Full_T
11230 -- Verify that it is not otherwise controlled by
11231 -- a formal or a return value ot type T.
11233 Check_Controlling_Formals (D_Type, Prim);
11237 Next_Entity (Prim);
11241 -- For the tagged case, the two views can share the same
11242 -- Primitive Operation list and the same class wide type.
11243 -- Update attributes of the class-wide type which depend on
11244 -- the full declaration.
11246 if Is_Tagged_Type (Priv_T) then
11247 Set_Primitive_Operations (Priv_T, Full_List);
11248 Set_Class_Wide_Type
11249 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
11251 -- Any other attributes should be propagated to C_W ???
11253 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
11258 end Process_Full_View;
11260 -----------------------------------
11261 -- Process_Incomplete_Dependents --
11262 -----------------------------------
11264 procedure Process_Incomplete_Dependents
11266 Full_T : Entity_Id;
11269 Inc_Elmt : Elmt_Id;
11270 Priv_Dep : Entity_Id;
11271 New_Subt : Entity_Id;
11273 Disc_Constraint : Elist_Id;
11276 if No (Private_Dependents (Inc_T)) then
11280 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
11282 -- Itypes that may be generated by the completion of an incomplete
11283 -- subtype are not used by the back-end and not attached to the tree.
11284 -- They are created only for constraint-checking purposes.
11287 while Present (Inc_Elmt) loop
11288 Priv_Dep := Node (Inc_Elmt);
11290 if Ekind (Priv_Dep) = E_Subprogram_Type then
11292 -- An Access_To_Subprogram type may have a return type or a
11293 -- parameter type that is incomplete. Replace with the full view.
11295 if Etype (Priv_Dep) = Inc_T then
11296 Set_Etype (Priv_Dep, Full_T);
11300 Formal : Entity_Id;
11303 Formal := First_Formal (Priv_Dep);
11305 while Present (Formal) loop
11307 if Etype (Formal) = Inc_T then
11308 Set_Etype (Formal, Full_T);
11311 Next_Formal (Formal);
11315 elsif Is_Overloadable (Priv_Dep) then
11317 if Is_Tagged_Type (Full_T) then
11319 -- Subprogram has an access parameter whose designated type
11320 -- was incomplete. Reexamine declaration now, because it may
11321 -- be a primitive operation of the full type.
11323 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
11324 Set_Is_Dispatching_Operation (Priv_Dep);
11325 Check_Controlling_Formals (Full_T, Priv_Dep);
11328 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
11330 -- Can happen during processing of a body before the completion
11331 -- of a TA type. Ignore, because spec is also on dependent list.
11335 -- Dependent is a subtype
11338 -- We build a new subtype indication using the full view of the
11339 -- incomplete parent. The discriminant constraints have been
11340 -- elaborated already at the point of the subtype declaration.
11342 New_Subt := Create_Itype (E_Void, N);
11344 if Has_Discriminants (Full_T) then
11345 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
11347 Disc_Constraint := No_Elist;
11350 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
11351 Set_Full_View (Priv_Dep, New_Subt);
11354 Next_Elmt (Inc_Elmt);
11357 end Process_Incomplete_Dependents;
11359 --------------------------------
11360 -- Process_Range_Expr_In_Decl --
11361 --------------------------------
11363 procedure Process_Range_Expr_In_Decl
11366 Related_Nod : Node_Id;
11367 Check_List : List_Id := Empty_List;
11368 R_Check_Off : Boolean := False)
11371 R_Checks : Check_Result;
11372 Type_Decl : Node_Id;
11373 Def_Id : Entity_Id;
11376 Analyze_And_Resolve (R, Base_Type (T));
11378 if Nkind (R) = N_Range then
11379 Lo := Low_Bound (R);
11380 Hi := High_Bound (R);
11382 -- If there were errors in the declaration, try and patch up some
11383 -- common mistakes in the bounds. The cases handled are literals
11384 -- which are Integer where the expected type is Real and vice versa.
11385 -- These corrections allow the compilation process to proceed further
11386 -- along since some basic assumptions of the format of the bounds
11389 if Etype (R) = Any_Type then
11391 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
11393 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
11395 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
11397 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
11399 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
11401 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
11403 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
11405 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
11412 -- If the bounds of the range have been mistakenly given as
11413 -- string literals (perhaps in place of character literals),
11414 -- then an error has already been reported, but we rewrite
11415 -- the string literal as a bound of the range's type to
11416 -- avoid blowups in later processing that looks at static
11419 if Nkind (Lo) = N_String_Literal then
11421 Make_Attribute_Reference (Sloc (Lo),
11422 Attribute_Name => Name_First,
11423 Prefix => New_Reference_To (T, Sloc (Lo))));
11424 Analyze_And_Resolve (Lo);
11427 if Nkind (Hi) = N_String_Literal then
11429 Make_Attribute_Reference (Sloc (Hi),
11430 Attribute_Name => Name_First,
11431 Prefix => New_Reference_To (T, Sloc (Hi))));
11432 Analyze_And_Resolve (Hi);
11435 -- If bounds aren't scalar at this point then exit, avoiding
11436 -- problems with further processing of the range in this procedure.
11438 if not Is_Scalar_Type (Etype (Lo)) then
11442 -- Resolve (actually Sem_Eval) has checked that the bounds are in
11443 -- then range of the base type. Here we check whether the bounds
11444 -- are in the range of the subtype itself. Note that if the bounds
11445 -- represent the null range the Constraint_Error exception should
11448 -- ??? The following code should be cleaned up as follows
11449 -- 1. The Is_Null_Range (Lo, Hi) test should disapper since it
11450 -- is done in the call to Range_Check (R, T); below
11451 -- 2. The use of R_Check_Off should be investigated and possibly
11452 -- removed, this would clean up things a bit.
11454 if Is_Null_Range (Lo, Hi) then
11458 -- We use a flag here instead of suppressing checks on the
11459 -- type because the type we check against isn't necessarily the
11460 -- place where we put the check.
11462 if not R_Check_Off then
11463 R_Checks := Range_Check (R, T);
11464 Type_Decl := Parent (R);
11466 -- Look up tree to find an appropriate insertion point.
11467 -- This seems really junk code, and very brittle, couldn't
11468 -- we just use an insert actions call of some kind ???
11470 while Present (Type_Decl) and then not
11471 (Nkind (Type_Decl) = N_Full_Type_Declaration
11473 Nkind (Type_Decl) = N_Subtype_Declaration
11475 Nkind (Type_Decl) = N_Loop_Statement
11477 Nkind (Type_Decl) = N_Task_Type_Declaration
11479 Nkind (Type_Decl) = N_Single_Task_Declaration
11481 Nkind (Type_Decl) = N_Protected_Type_Declaration
11483 Nkind (Type_Decl) = N_Single_Protected_Declaration)
11485 Type_Decl := Parent (Type_Decl);
11488 -- Why would Type_Decl not be present??? Without this test,
11489 -- short regression tests fail.
11491 if Present (Type_Decl) then
11492 if Nkind (Type_Decl) = N_Loop_Statement then
11494 Indic : Node_Id := Parent (R);
11496 while Present (Indic) and then not
11497 (Nkind (Indic) = N_Subtype_Indication)
11499 Indic := Parent (Indic);
11502 if Present (Indic) then
11503 Def_Id := Etype (Subtype_Mark (Indic));
11505 Insert_Range_Checks
11511 Do_Before => True);
11515 Def_Id := Defining_Identifier (Type_Decl);
11517 if (Ekind (Def_Id) = E_Record_Type
11518 and then Depends_On_Discriminant (R))
11520 (Ekind (Def_Id) = E_Protected_Type
11521 and then Has_Discriminants (Def_Id))
11523 Append_Range_Checks
11524 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
11527 Insert_Range_Checks
11528 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
11537 Get_Index_Bounds (R, Lo, Hi);
11539 if Expander_Active then
11540 Force_Evaluation (Lo);
11541 Force_Evaluation (Hi);
11544 end Process_Range_Expr_In_Decl;
11546 --------------------------------------
11547 -- Process_Real_Range_Specification --
11548 --------------------------------------
11550 procedure Process_Real_Range_Specification (Def : Node_Id) is
11551 Spec : constant Node_Id := Real_Range_Specification (Def);
11554 Err : Boolean := False;
11556 procedure Analyze_Bound (N : Node_Id);
11557 -- Analyze and check one bound
11559 procedure Analyze_Bound (N : Node_Id) is
11561 Analyze_And_Resolve (N, Any_Real);
11563 if not Is_OK_Static_Expression (N) then
11565 ("bound in real type definition is not static", N);
11571 if Present (Spec) then
11572 Lo := Low_Bound (Spec);
11573 Hi := High_Bound (Spec);
11574 Analyze_Bound (Lo);
11575 Analyze_Bound (Hi);
11577 -- If error, clear away junk range specification
11580 Set_Real_Range_Specification (Def, Empty);
11583 end Process_Real_Range_Specification;
11585 ---------------------
11586 -- Process_Subtype --
11587 ---------------------
11589 function Process_Subtype
11591 Related_Nod : Node_Id;
11592 Related_Id : Entity_Id := Empty;
11593 Suffix : Character := ' ')
11597 Def_Id : Entity_Id;
11598 Full_View_Id : Entity_Id;
11599 Subtype_Mark_Id : Entity_Id;
11600 N_Dynamic_Ityp : Node_Id := Empty;
11603 -- Case of constraint present, so that we have an N_Subtype_Indication
11604 -- node (this node is created only if constraints are present).
11606 if Nkind (S) = N_Subtype_Indication then
11607 Find_Type (Subtype_Mark (S));
11609 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
11611 (Nkind (Parent (S)) = N_Subtype_Declaration
11613 Is_Itype (Defining_Identifier (Parent (S))))
11615 Check_Incomplete (Subtype_Mark (S));
11619 Subtype_Mark_Id := Entity (Subtype_Mark (S));
11621 if Is_Unchecked_Union (Subtype_Mark_Id)
11622 and then Comes_From_Source (Related_Nod)
11625 ("cannot create subtype of Unchecked_Union", Related_Nod);
11628 -- Explicit subtype declaration case
11630 if Nkind (P) = N_Subtype_Declaration then
11631 Def_Id := Defining_Identifier (P);
11633 -- Explicit derived type definition case
11635 elsif Nkind (P) = N_Derived_Type_Definition then
11636 Def_Id := Defining_Identifier (Parent (P));
11638 -- Implicit case, the Def_Id must be created as an implicit type.
11639 -- The one exception arises in the case of concurrent types,
11640 -- array and access types, where other subsidiary implicit types
11641 -- may be created and must appear before the main implicit type.
11642 -- In these cases we leave Def_Id set to Empty as a signal that
11643 -- Create_Itype has not yet been called to create Def_Id.
11646 if Is_Array_Type (Subtype_Mark_Id)
11647 or else Is_Concurrent_Type (Subtype_Mark_Id)
11648 or else Is_Access_Type (Subtype_Mark_Id)
11652 -- For the other cases, we create a new unattached Itype,
11653 -- and set the indication to ensure it gets attached later.
11657 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11660 N_Dynamic_Ityp := Related_Nod;
11663 -- If the kind of constraint is invalid for this kind of type,
11664 -- then give an error, and then pretend no constraint was given.
11666 if not Is_Valid_Constraint_Kind
11667 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
11670 ("incorrect constraint for this kind of type", Constraint (S));
11672 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
11674 -- Make recursive call, having got rid of the bogus constraint
11676 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
11679 -- Remaining processing depends on type
11681 case Ekind (Subtype_Mark_Id) is
11683 when Access_Kind =>
11684 Constrain_Access (Def_Id, S, Related_Nod);
11687 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
11689 when Decimal_Fixed_Point_Kind =>
11690 Constrain_Decimal (Def_Id, S, N_Dynamic_Ityp);
11692 when Enumeration_Kind =>
11693 Constrain_Enumeration (Def_Id, S, N_Dynamic_Ityp);
11695 when Ordinary_Fixed_Point_Kind =>
11696 Constrain_Ordinary_Fixed (Def_Id, S, N_Dynamic_Ityp);
11699 Constrain_Float (Def_Id, S, N_Dynamic_Ityp);
11701 when Integer_Kind =>
11702 Constrain_Integer (Def_Id, S, N_Dynamic_Ityp);
11704 when E_Record_Type |
11707 E_Incomplete_Type =>
11708 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11710 when Private_Kind =>
11711 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11712 Set_Private_Dependents (Def_Id, New_Elmt_List);
11714 -- In case of an invalid constraint prevent further processing
11715 -- since the type constructed is missing expected fields.
11717 if Etype (Def_Id) = Any_Type then
11721 -- If the full view is that of a task with discriminants,
11722 -- we must constrain both the concurrent type and its
11723 -- corresponding record type. Otherwise we will just propagate
11724 -- the constraint to the full view, if available.
11726 if Present (Full_View (Subtype_Mark_Id))
11727 and then Has_Discriminants (Subtype_Mark_Id)
11728 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
11731 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11733 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
11734 Constrain_Concurrent (Full_View_Id, S,
11735 Related_Nod, Related_Id, Suffix);
11736 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
11737 Set_Full_View (Def_Id, Full_View_Id);
11740 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
11743 when Concurrent_Kind =>
11744 Constrain_Concurrent (Def_Id, S,
11745 Related_Nod, Related_Id, Suffix);
11748 Error_Msg_N ("invalid subtype mark in subtype indication", S);
11751 -- Size and Convention are always inherited from the base type
11753 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
11754 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
11758 -- Case of no constraints present
11762 Check_Incomplete (S);
11765 end Process_Subtype;
11767 -----------------------------
11768 -- Record_Type_Declaration --
11769 -----------------------------
11771 procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id) is
11772 Def : constant Node_Id := Type_Definition (N);
11773 Range_Checks_Suppressed_Flag : Boolean := False;
11775 Is_Tagged : Boolean;
11776 Tag_Comp : Entity_Id;
11779 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
11780 -- if it detected an error for declaration T. This arises in the case of
11781 -- private tagged types where the full view omits the word tagged.
11783 Is_Tagged := Tagged_Present (Def)
11784 or else (Errors_Detected > 0 and then Is_Tagged_Type (T));
11786 -- Records constitute a scope for the component declarations within.
11787 -- The scope is created prior to the processing of these declarations.
11788 -- Discriminants are processed first, so that they are visible when
11789 -- processing the other components. The Ekind of the record type itself
11790 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
11792 -- Enter record scope
11796 -- These flags must be initialized before calling Process_Discriminants
11797 -- because this routine makes use of them.
11799 Set_Is_Tagged_Type (T, Is_Tagged);
11800 Set_Is_Limited_Record (T, Limited_Present (Def));
11802 -- Type is abstract if full declaration carries keyword, or if
11803 -- previous partial view did.
11805 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
11807 Set_Ekind (T, E_Record_Type);
11809 Init_Size_Align (T);
11811 Set_Girder_Constraint (T, No_Elist);
11813 -- If an incomplete or private type declaration was already given for
11814 -- the type, then this scope already exists, and the discriminants have
11815 -- been declared within. We must verify that the full declaration
11816 -- matches the incomplete one.
11818 Check_Or_Process_Discriminants (N, T);
11820 Set_Is_Constrained (T, not Has_Discriminants (T));
11821 Set_Has_Delayed_Freeze (T, True);
11823 -- For tagged types add a manually analyzed component corresponding
11824 -- to the component _tag, the corresponding piece of tree will be
11825 -- expanded as part of the freezing actions if it is not a CPP_Class.
11828 -- Do not add the tag unless we are in expansion mode.
11830 if Expander_Active then
11831 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
11832 Enter_Name (Tag_Comp);
11834 Set_Is_Tag (Tag_Comp);
11835 Set_Ekind (Tag_Comp, E_Component);
11836 Set_Etype (Tag_Comp, RTE (RE_Tag));
11837 Set_DT_Entry_Count (Tag_Comp, No_Uint);
11838 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
11839 Init_Component_Location (Tag_Comp);
11842 Make_Class_Wide_Type (T);
11843 Set_Primitive_Operations (T, New_Elmt_List);
11846 -- We must suppress range checks when processing the components
11847 -- of a record in the presence of discriminants, since we don't
11848 -- want spurious checks to be generated during their analysis, but
11849 -- must reset the Suppress_Range_Checks flags after having procesed
11850 -- the record definition.
11852 if Has_Discriminants (T) and then not Suppress_Range_Checks (T) then
11853 Set_Suppress_Range_Checks (T, True);
11854 Range_Checks_Suppressed_Flag := True;
11857 Record_Type_Definition (Def, T);
11859 if Range_Checks_Suppressed_Flag then
11860 Set_Suppress_Range_Checks (T, False);
11861 Range_Checks_Suppressed_Flag := False;
11864 -- Exit from record scope
11867 end Record_Type_Declaration;
11869 ----------------------------
11870 -- Record_Type_Definition --
11871 ----------------------------
11873 procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id) is
11874 Component : Entity_Id;
11875 Ctrl_Components : Boolean := False;
11876 Final_Storage_Only : Boolean := not Is_Controlled (T);
11879 -- If the component list of a record type is defined by the reserved
11880 -- word null and there is no discriminant part, then the record type has
11881 -- no components and all records of the type are null records (RM 3.7)
11882 -- This procedure is also called to process the extension part of a
11883 -- record extension, in which case the current scope may have inherited
11887 or else No (Component_List (Def))
11888 or else Null_Present (Component_List (Def))
11893 Analyze_Declarations (Component_Items (Component_List (Def)));
11895 if Present (Variant_Part (Component_List (Def))) then
11896 Analyze (Variant_Part (Component_List (Def)));
11900 -- After completing the semantic analysis of the record definition,
11901 -- record components, both new and inherited, are accessible. Set
11902 -- their kind accordingly.
11904 Component := First_Entity (Current_Scope);
11905 while Present (Component) loop
11907 if Ekind (Component) = E_Void then
11908 Set_Ekind (Component, E_Component);
11909 Init_Component_Location (Component);
11912 if Has_Task (Etype (Component)) then
11916 if Ekind (Component) /= E_Component then
11919 elsif Has_Controlled_Component (Etype (Component))
11920 or else (Chars (Component) /= Name_uParent
11921 and then Is_Controlled (Etype (Component)))
11923 Set_Has_Controlled_Component (T, True);
11924 Final_Storage_Only := Final_Storage_Only
11925 and then Finalize_Storage_Only (Etype (Component));
11926 Ctrl_Components := True;
11929 Next_Entity (Component);
11932 -- A type is Finalize_Storage_Only only if all its controlled
11933 -- components are so.
11935 if Ctrl_Components then
11936 Set_Finalize_Storage_Only (T, Final_Storage_Only);
11939 if Present (Def) then
11940 Process_End_Label (Def, 'e');
11942 end Record_Type_Definition;
11944 ---------------------
11945 -- Set_Fixed_Range --
11946 ---------------------
11948 -- The range for fixed-point types is complicated by the fact that we
11949 -- do not know the exact end points at the time of the declaration. This
11950 -- is true for three reasons:
11952 -- A size clause may affect the fudging of the end-points
11953 -- A small clause may affect the values of the end-points
11954 -- We try to include the end-points if it does not affect the size
11956 -- This means that the actual end-points must be established at the
11957 -- point when the type is frozen. Meanwhile, we first narrow the range
11958 -- as permitted (so that it will fit if necessary in a small specified
11959 -- size), and then build a range subtree with these narrowed bounds.
11961 -- Set_Fixed_Range constructs the range from real literal values, and
11962 -- sets the range as the Scalar_Range of the given fixed-point type
11965 -- The parent of this range is set to point to the entity so that it
11966 -- is properly hooked into the tree (unlike normal Scalar_Range entries
11967 -- for other scalar types, which are just pointers to the range in the
11968 -- original tree, this would otherwise be an orphan).
11970 -- The tree is left unanalyzed. When the type is frozen, the processing
11971 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
11972 -- analyzed, and uses this as an indication that it should complete
11973 -- work on the range (it will know the final small and size values).
11975 procedure Set_Fixed_Range
11981 S : constant Node_Id :=
11983 Low_Bound => Make_Real_Literal (Loc, Lo),
11984 High_Bound => Make_Real_Literal (Loc, Hi));
11987 Set_Scalar_Range (E, S);
11989 end Set_Fixed_Range;
11991 --------------------------------------------------------
11992 -- Set_Girder_Constraint_From_Discriminant_Constraint --
11993 --------------------------------------------------------
11995 procedure Set_Girder_Constraint_From_Discriminant_Constraint
11999 -- Make sure set if encountered during
12000 -- Expand_To_Girder_Constraint
12002 Set_Girder_Constraint (E, No_Elist);
12004 -- Give it the right value
12006 if Is_Constrained (E) and then Has_Discriminants (E) then
12007 Set_Girder_Constraint (E,
12008 Expand_To_Girder_Constraint (E, Discriminant_Constraint (E)));
12011 end Set_Girder_Constraint_From_Discriminant_Constraint;
12013 ----------------------------------
12014 -- Set_Scalar_Range_For_Subtype --
12015 ----------------------------------
12017 procedure Set_Scalar_Range_For_Subtype
12018 (Def_Id : Entity_Id;
12021 Related_Nod : Node_Id)
12023 Kind : constant Entity_Kind := Ekind (Def_Id);
12025 Set_Scalar_Range (Def_Id, R);
12027 -- We need to link the range into the tree before resolving it so
12028 -- that types that are referenced, including importantly the subtype
12029 -- itself, are properly frozen (Freeze_Expression requires that the
12030 -- expression be properly linked into the tree). Of course if it is
12031 -- already linked in, then we do not disturb the current link.
12033 if No (Parent (R)) then
12034 Set_Parent (R, Def_Id);
12037 -- Reset the kind of the subtype during analysis of the range, to
12038 -- catch possible premature use in the bounds themselves.
12040 Set_Ekind (Def_Id, E_Void);
12041 Process_Range_Expr_In_Decl (R, Subt, Related_Nod);
12042 Set_Ekind (Def_Id, Kind);
12044 end Set_Scalar_Range_For_Subtype;
12046 -------------------------------------
12047 -- Signed_Integer_Type_Declaration --
12048 -------------------------------------
12050 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
12051 Implicit_Base : Entity_Id;
12052 Base_Typ : Entity_Id;
12055 Errs : Boolean := False;
12059 function Can_Derive_From (E : Entity_Id) return Boolean;
12060 -- Determine whether given bounds allow derivation from specified type
12062 procedure Check_Bound (Expr : Node_Id);
12063 -- Check bound to make sure it is integral and static. If not, post
12064 -- appropriate error message and set Errs flag
12066 function Can_Derive_From (E : Entity_Id) return Boolean is
12067 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
12068 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
12071 -- Note we check both bounds against both end values, to deal with
12072 -- strange types like ones with a range of 0 .. -12341234.
12074 return Lo <= Lo_Val and then Lo_Val <= Hi
12076 Lo <= Hi_Val and then Hi_Val <= Hi;
12077 end Can_Derive_From;
12079 procedure Check_Bound (Expr : Node_Id) is
12081 -- If a range constraint is used as an integer type definition, each
12082 -- bound of the range must be defined by a static expression of some
12083 -- integer type, but the two bounds need not have the same integer
12084 -- type (Negative bounds are allowed.) (RM 3.5.4)
12086 if not Is_Integer_Type (Etype (Expr)) then
12088 ("integer type definition bounds must be of integer type", Expr);
12091 elsif not Is_OK_Static_Expression (Expr) then
12093 ("non-static expression used for integer type bound", Expr);
12096 -- The bounds are folded into literals, and we set their type to be
12097 -- universal, to avoid typing difficulties: we cannot set the type
12098 -- of the literal to the new type, because this would be a forward
12099 -- reference for the back end, and if the original type is user-
12100 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
12103 if Is_Entity_Name (Expr) then
12104 Fold_Uint (Expr, Expr_Value (Expr));
12107 Set_Etype (Expr, Universal_Integer);
12111 -- Start of processing for Signed_Integer_Type_Declaration
12114 -- Create an anonymous base type
12117 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
12119 -- Analyze and check the bounds, they can be of any integer type
12121 Lo := Low_Bound (Def);
12122 Hi := High_Bound (Def);
12124 -- Arbitrarily use Integer as the type if either bound had an error
12126 if Hi = Error or else Lo = Error then
12127 Base_Typ := Any_Integer;
12128 Set_Error_Posted (T, True);
12130 -- Here both bounds are OK expressions
12133 Analyze_And_Resolve (Lo, Any_Integer);
12134 Analyze_And_Resolve (Hi, Any_Integer);
12140 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12141 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12144 -- Find type to derive from
12146 Lo_Val := Expr_Value (Lo);
12147 Hi_Val := Expr_Value (Hi);
12149 if Can_Derive_From (Standard_Short_Short_Integer) then
12150 Base_Typ := Base_Type (Standard_Short_Short_Integer);
12152 elsif Can_Derive_From (Standard_Short_Integer) then
12153 Base_Typ := Base_Type (Standard_Short_Integer);
12155 elsif Can_Derive_From (Standard_Integer) then
12156 Base_Typ := Base_Type (Standard_Integer);
12158 elsif Can_Derive_From (Standard_Long_Integer) then
12159 Base_Typ := Base_Type (Standard_Long_Integer);
12161 elsif Can_Derive_From (Standard_Long_Long_Integer) then
12162 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12165 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12166 Error_Msg_N ("integer type definition bounds out of range", Def);
12167 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12168 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12172 -- Complete both implicit base and declared first subtype entities
12174 Set_Etype (Implicit_Base, Base_Typ);
12175 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
12176 Set_Size_Info (Implicit_Base, (Base_Typ));
12177 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
12178 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
12180 Set_Ekind (T, E_Signed_Integer_Subtype);
12181 Set_Etype (T, Implicit_Base);
12183 Set_Size_Info (T, (Implicit_Base));
12184 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
12185 Set_Scalar_Range (T, Def);
12186 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
12187 Set_Is_Constrained (T);
12189 end Signed_Integer_Type_Declaration;