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-documentation:
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 -- initialization 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
1609 -- Aggregate is statically illegal. Place back in declaration
1611 Set_Expression (N, E);
1612 Set_No_Initialization (N, False);
1614 elsif T = Etype (E) then
1617 elsif Nkind (E) = N_Aggregate
1618 and then Present (Component_Associations (E))
1619 and then Present (Choices (First (Component_Associations (E))))
1620 and then Nkind (First
1621 (Choices (First (Component_Associations (E))))) = N_Others_Choice
1626 Apply_Length_Check (E, T);
1629 elsif (Is_Limited_Record (T)
1630 or else Is_Concurrent_Type (T))
1631 and then not Is_Constrained (T)
1632 and then Has_Discriminants (T)
1634 Act_T := Build_Default_Subtype;
1635 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
1637 elsif not Is_Constrained (T)
1638 and then Has_Discriminants (T)
1639 and then Constant_Present (N)
1640 and then Nkind (E) = N_Function_Call
1642 -- The back-end has problems with constants of a discriminated type
1643 -- with defaults, if the initial value is a function call. We
1644 -- generate an intermediate temporary for the result of the call.
1645 -- It is unclear why this should make it acceptable to gcc. ???
1647 Remove_Side_Effects (E);
1650 if T = Standard_Wide_Character
1651 or else Root_Type (T) = Standard_Wide_String
1653 Check_Restriction (No_Wide_Characters, Object_Definition (N));
1656 -- Now establish the proper kind and type of the object
1658 if Constant_Present (N) then
1659 Set_Ekind (Id, E_Constant);
1660 Set_Not_Source_Assigned (Id, True);
1661 Set_Is_True_Constant (Id, True);
1664 Set_Ekind (Id, E_Variable);
1666 -- A variable is set as shared passive if it appears in a shared
1667 -- passive package, and is at the outer level. This is not done
1668 -- for entities generated during expansion, because those are
1669 -- always manipulated locally.
1671 if Is_Shared_Passive (Current_Scope)
1672 and then Is_Library_Level_Entity (Id)
1673 and then Comes_From_Source (Id)
1675 Set_Is_Shared_Passive (Id);
1676 Check_Shared_Var (Id, T, N);
1679 -- If an initializing expression is present, then the variable
1680 -- is potentially a true constant if no further assignments are
1681 -- present. The code generator can use this for optimization.
1682 -- The flag will be reset if there are any assignments. We only
1683 -- set this flag for non library level entities, since for any
1684 -- library level entities, assignments could exist in other units.
1687 if not Is_Library_Level_Entity (Id) then
1689 -- For now we omit this, because it seems to cause some
1690 -- problems. In particular, if you uncomment this out, then
1691 -- test case 4427-002 will fail for unclear reasons ???
1694 Set_Is_True_Constant (Id);
1698 -- Case of no initializing expression present. If the type is not
1699 -- fully initialized, then we set Not_Source_Assigned, since this
1700 -- is a case of a potentially uninitialized object. Note that we
1701 -- do not consider access variables to be fully initialized for
1702 -- this purpose, since it still seems dubious if someone declares
1703 -- an access variable and never assigns to it.
1706 if Is_Access_Type (T)
1707 or else not Is_Fully_Initialized_Type (T)
1709 Set_Not_Source_Assigned (Id);
1714 Init_Alignment (Id);
1717 if Aliased_Present (N) then
1718 Set_Is_Aliased (Id);
1721 and then Is_Record_Type (T)
1722 and then not Is_Constrained (T)
1723 and then Has_Discriminants (T)
1725 Set_Actual_Subtype (Id, Build_Default_Subtype);
1729 Set_Etype (Id, Act_T);
1731 if Has_Controlled_Component (Etype (Id))
1732 or else Is_Controlled (Etype (Id))
1734 if not Is_Library_Level_Entity (Id) then
1735 Check_Restriction (No_Nested_Finalization, N);
1738 Validate_Controlled_Object (Id);
1741 -- Generate a warning when an initialization causes an obvious
1742 -- ABE violation. If the init expression is a simple aggregate
1743 -- there shouldn't be any initialize/adjust call generated. This
1744 -- will be true as soon as aggregates are built in place when
1745 -- possible. ??? at the moment we do not generate warnings for
1746 -- temporaries created for those aggregates although a
1747 -- Program_Error might be generated if compiled with -gnato
1749 if Is_Controlled (Etype (Id))
1750 and then Comes_From_Source (Id)
1753 BT : constant Entity_Id := Base_Type (Etype (Id));
1754 Implicit_Call : Entity_Id;
1756 function Is_Aggr (N : Node_Id) return Boolean;
1757 -- Check that N is an aggregate
1759 function Is_Aggr (N : Node_Id) return Boolean is
1761 case Nkind (Original_Node (N)) is
1762 when N_Aggregate | N_Extension_Aggregate =>
1765 when N_Qualified_Expression |
1767 N_Unchecked_Type_Conversion =>
1768 return Is_Aggr (Expression (Original_Node (N)));
1776 -- If no underlying type, we already are in an error situation
1777 -- don't try to add a warning since we do not have access
1780 if No (Underlying_Type (BT)) then
1781 Implicit_Call := Empty;
1783 -- A generic type does not have usable primitive operators.
1784 -- Initialization calls are built for instances.
1786 elsif Is_Generic_Type (BT) then
1787 Implicit_Call := Empty;
1789 -- if the init expression is not an aggregate, an adjust
1790 -- call will be generated
1792 elsif Present (E) and then not Is_Aggr (E) then
1793 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
1795 -- if no init expression and we are not in the deferred
1796 -- constant case, an Initialize call will be generated
1798 elsif No (E) and then not Constant_Present (N) then
1799 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
1802 Implicit_Call := Empty;
1808 if Has_Task (Etype (Id)) then
1809 if not Is_Library_Level_Entity (Id) then
1810 Check_Restriction (No_Task_Hierarchy, N);
1811 Check_Potentially_Blocking_Operation (N);
1815 -- Some simple constant-propagation: if the expression is a constant
1816 -- string initialized with a literal, share the literal. This avoids
1820 and then Is_Entity_Name (E)
1821 and then Ekind (Entity (E)) = E_Constant
1822 and then Base_Type (Etype (E)) = Standard_String
1825 Val : constant Node_Id := Constant_Value (Entity (E));
1829 and then Nkind (Val) = N_String_Literal
1831 Rewrite (E, New_Copy (Val));
1836 -- Another optimization: if the nominal subtype is unconstrained and
1837 -- the expression is a function call that returns and unconstrained
1838 -- type, rewrite the declararation as a renaming of the result of the
1839 -- call. The exceptions below are cases where the copy is expected,
1840 -- either by the back end (Aliased case) or by the semantics, as for
1841 -- initializing controlled types or copying tags for classwide types.
1844 and then Nkind (E) = N_Explicit_Dereference
1845 and then Nkind (Original_Node (E)) = N_Function_Call
1846 and then not Is_Library_Level_Entity (Id)
1847 and then not Is_Constrained (T)
1848 and then not Is_Aliased (Id)
1849 and then not Is_Class_Wide_Type (T)
1850 and then not Is_Controlled (T)
1851 and then not Has_Controlled_Component (Base_Type (T))
1852 and then Expander_Active
1855 Make_Object_Renaming_Declaration (Loc,
1856 Defining_Identifier => Id,
1857 Subtype_Mark => New_Occurrence_Of
1858 (Base_Type (Etype (Id)), Loc),
1861 Set_Renamed_Object (Id, E);
1864 if Present (Prev_Entity)
1865 and then Is_Frozen (Prev_Entity)
1866 and then not Error_Posted (Id)
1868 Error_Msg_N ("full constant declaration appears too late", N);
1871 Check_Eliminated (Id);
1872 end Analyze_Object_Declaration;
1874 ---------------------------
1875 -- Analyze_Others_Choice --
1876 ---------------------------
1878 -- Nothing to do for the others choice node itself, the semantic analysis
1879 -- of the others choice will occur as part of the processing of the parent
1881 procedure Analyze_Others_Choice (N : Node_Id) is
1884 end Analyze_Others_Choice;
1886 -------------------------------------------
1887 -- Analyze_Private_Extension_Declaration --
1888 -------------------------------------------
1890 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
1891 T : Entity_Id := Defining_Identifier (N);
1892 Indic : constant Node_Id := Subtype_Indication (N);
1893 Parent_Type : Entity_Id;
1894 Parent_Base : Entity_Id;
1897 Generate_Definition (T);
1900 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
1901 Parent_Base := Base_Type (Parent_Type);
1903 if Parent_Type = Any_Type
1904 or else Etype (Parent_Type) = Any_Type
1906 Set_Ekind (T, Ekind (Parent_Type));
1907 Set_Etype (T, Any_Type);
1910 elsif not Is_Tagged_Type (Parent_Type) then
1912 ("parent of type extension must be a tagged type ", Indic);
1915 elsif Ekind (Parent_Type) = E_Void
1916 or else Ekind (Parent_Type) = E_Incomplete_Type
1918 Error_Msg_N ("premature derivation of incomplete type", Indic);
1922 -- Perhaps the parent type should be changed to the class-wide type's
1923 -- specific type in this case to prevent cascading errors ???
1925 if Is_Class_Wide_Type (Parent_Type) then
1927 ("parent of type extension must not be a class-wide type", Indic);
1931 if (not Is_Package (Current_Scope)
1932 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
1933 or else In_Private_Part (Current_Scope)
1936 Error_Msg_N ("invalid context for private extension", N);
1939 -- Set common attributes
1941 Set_Is_Pure (T, Is_Pure (Current_Scope));
1942 Set_Scope (T, Current_Scope);
1943 Set_Ekind (T, E_Record_Type_With_Private);
1944 Init_Size_Align (T);
1946 Set_Etype (T, Parent_Base);
1947 Set_Has_Task (T, Has_Task (Parent_Base));
1949 Set_Convention (T, Convention (Parent_Type));
1950 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
1951 Set_Is_First_Subtype (T);
1952 Make_Class_Wide_Type (T);
1954 Build_Derived_Record_Type (N, Parent_Type, T);
1955 end Analyze_Private_Extension_Declaration;
1957 ---------------------------------
1958 -- Analyze_Subtype_Declaration --
1959 ---------------------------------
1961 procedure Analyze_Subtype_Declaration (N : Node_Id) is
1962 Id : constant Entity_Id := Defining_Identifier (N);
1964 R_Checks : Check_Result;
1967 Generate_Definition (Id);
1968 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1969 Init_Size_Align (Id);
1971 -- The following guard condition on Enter_Name is to handle cases
1972 -- where the defining identifier has already been entered into the
1973 -- scope but the declaration as a whole needs to be analyzed.
1975 -- This case in particular happens for derived enumeration types.
1976 -- The derived enumeration type is processed as an inserted enumeration
1977 -- type declaration followed by a rewritten subtype declaration. The
1978 -- defining identifier, however, is entered into the name scope very
1979 -- early in the processing of the original type declaration and
1980 -- therefore needs to be avoided here, when the created subtype
1981 -- declaration is analyzed. (See Build_Derived_Types)
1983 -- This also happens when the full view of a private type is a
1984 -- derived type with constraints. In this case the entity has been
1985 -- introduced in the private declaration.
1987 if Present (Etype (Id))
1988 and then (Is_Private_Type (Etype (Id))
1989 or else Is_Task_Type (Etype (Id))
1990 or else Is_Rewrite_Substitution (N))
1998 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
2000 -- Inherit common attributes
2002 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
2003 Set_Is_Volatile (Id, Is_Volatile (T));
2004 Set_Is_Atomic (Id, Is_Atomic (T));
2006 -- In the case where there is no constraint given in the subtype
2007 -- indication, Process_Subtype just returns the Subtype_Mark,
2008 -- so its semantic attributes must be established here.
2010 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
2011 Set_Etype (Id, Base_Type (T));
2015 Set_Ekind (Id, E_Array_Subtype);
2017 -- Shouldn't we call Copy_Array_Subtype_Attributes here???
2019 Set_First_Index (Id, First_Index (T));
2020 Set_Is_Aliased (Id, Is_Aliased (T));
2021 Set_Is_Constrained (Id, Is_Constrained (T));
2023 when Decimal_Fixed_Point_Kind =>
2024 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
2025 Set_Digits_Value (Id, Digits_Value (T));
2026 Set_Delta_Value (Id, Delta_Value (T));
2027 Set_Scale_Value (Id, Scale_Value (T));
2028 Set_Small_Value (Id, Small_Value (T));
2029 Set_Scalar_Range (Id, Scalar_Range (T));
2030 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
2031 Set_Is_Constrained (Id, Is_Constrained (T));
2032 Set_RM_Size (Id, RM_Size (T));
2034 when Enumeration_Kind =>
2035 Set_Ekind (Id, E_Enumeration_Subtype);
2036 Set_First_Literal (Id, First_Literal (Base_Type (T)));
2037 Set_Scalar_Range (Id, Scalar_Range (T));
2038 Set_Is_Character_Type (Id, Is_Character_Type (T));
2039 Set_Is_Constrained (Id, Is_Constrained (T));
2040 Set_RM_Size (Id, RM_Size (T));
2042 when Ordinary_Fixed_Point_Kind =>
2043 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
2044 Set_Scalar_Range (Id, Scalar_Range (T));
2045 Set_Small_Value (Id, Small_Value (T));
2046 Set_Delta_Value (Id, Delta_Value (T));
2047 Set_Is_Constrained (Id, Is_Constrained (T));
2048 Set_RM_Size (Id, RM_Size (T));
2051 Set_Ekind (Id, E_Floating_Point_Subtype);
2052 Set_Scalar_Range (Id, Scalar_Range (T));
2053 Set_Digits_Value (Id, Digits_Value (T));
2054 Set_Is_Constrained (Id, Is_Constrained (T));
2056 when Signed_Integer_Kind =>
2057 Set_Ekind (Id, E_Signed_Integer_Subtype);
2058 Set_Scalar_Range (Id, Scalar_Range (T));
2059 Set_Is_Constrained (Id, Is_Constrained (T));
2060 Set_RM_Size (Id, RM_Size (T));
2062 when Modular_Integer_Kind =>
2063 Set_Ekind (Id, E_Modular_Integer_Subtype);
2064 Set_Scalar_Range (Id, Scalar_Range (T));
2065 Set_Is_Constrained (Id, Is_Constrained (T));
2066 Set_RM_Size (Id, RM_Size (T));
2068 when Class_Wide_Kind =>
2069 Set_Ekind (Id, E_Class_Wide_Subtype);
2070 Set_First_Entity (Id, First_Entity (T));
2071 Set_Last_Entity (Id, Last_Entity (T));
2072 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2073 Set_Cloned_Subtype (Id, T);
2074 Set_Is_Tagged_Type (Id, True);
2075 Set_Has_Unknown_Discriminants
2078 if Ekind (T) = E_Class_Wide_Subtype then
2079 Set_Equivalent_Type (Id, Equivalent_Type (T));
2082 when E_Record_Type | E_Record_Subtype =>
2083 Set_Ekind (Id, E_Record_Subtype);
2085 if Ekind (T) = E_Record_Subtype
2086 and then Present (Cloned_Subtype (T))
2088 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
2090 Set_Cloned_Subtype (Id, T);
2093 Set_First_Entity (Id, First_Entity (T));
2094 Set_Last_Entity (Id, Last_Entity (T));
2095 Set_Has_Discriminants (Id, Has_Discriminants (T));
2096 Set_Is_Constrained (Id, Is_Constrained (T));
2097 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2098 Set_Has_Unknown_Discriminants
2099 (Id, Has_Unknown_Discriminants (T));
2101 if Has_Discriminants (T) then
2102 Set_Discriminant_Constraint
2103 (Id, Discriminant_Constraint (T));
2104 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2106 elsif Has_Unknown_Discriminants (Id) then
2107 Set_Discriminant_Constraint (Id, No_Elist);
2110 if Is_Tagged_Type (T) then
2111 Set_Is_Tagged_Type (Id);
2112 Set_Is_Abstract (Id, Is_Abstract (T));
2113 Set_Primitive_Operations
2114 (Id, Primitive_Operations (T));
2115 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2118 when Private_Kind =>
2119 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2120 Set_Has_Discriminants (Id, Has_Discriminants (T));
2121 Set_Is_Constrained (Id, Is_Constrained (T));
2122 Set_First_Entity (Id, First_Entity (T));
2123 Set_Last_Entity (Id, Last_Entity (T));
2124 Set_Private_Dependents (Id, New_Elmt_List);
2125 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2126 Set_Has_Unknown_Discriminants
2127 (Id, Has_Unknown_Discriminants (T));
2129 if Is_Tagged_Type (T) then
2130 Set_Is_Tagged_Type (Id);
2131 Set_Is_Abstract (Id, Is_Abstract (T));
2132 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2135 -- In general the attributes of the subtype of a private
2136 -- type are the attributes of the partial view of parent.
2137 -- However, the full view may be a discriminated type,
2138 -- and the subtype must share the discriminant constraint
2139 -- to generate correct calls to initialization procedures.
2141 if Has_Discriminants (T) then
2142 Set_Discriminant_Constraint
2143 (Id, Discriminant_Constraint (T));
2144 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2146 elsif Present (Full_View (T))
2147 and then Has_Discriminants (Full_View (T))
2149 Set_Discriminant_Constraint
2150 (Id, Discriminant_Constraint (Full_View (T)));
2151 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2153 -- This would seem semantically correct, but apparently
2154 -- confuses the back-end (4412-009). To be explained ???
2156 -- Set_Has_Discriminants (Id);
2159 Prepare_Private_Subtype_Completion (Id, N);
2162 Set_Ekind (Id, E_Access_Subtype);
2163 Set_Is_Constrained (Id, Is_Constrained (T));
2164 Set_Is_Access_Constant
2165 (Id, Is_Access_Constant (T));
2166 Set_Directly_Designated_Type
2167 (Id, Designated_Type (T));
2169 -- A Pure library_item must not contain the declaration of a
2170 -- named access type, except within a subprogram, generic
2171 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
2173 if Comes_From_Source (Id)
2174 and then In_Pure_Unit
2175 and then not In_Subprogram_Task_Protected_Unit
2178 ("named access types not allowed in pure unit", N);
2181 when Concurrent_Kind =>
2183 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2184 Set_Corresponding_Record_Type (Id,
2185 Corresponding_Record_Type (T));
2186 Set_First_Entity (Id, First_Entity (T));
2187 Set_First_Private_Entity (Id, First_Private_Entity (T));
2188 Set_Has_Discriminants (Id, Has_Discriminants (T));
2189 Set_Is_Constrained (Id, Is_Constrained (T));
2190 Set_Last_Entity (Id, Last_Entity (T));
2192 if Has_Discriminants (T) then
2193 Set_Discriminant_Constraint (Id,
2194 Discriminant_Constraint (T));
2195 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2198 -- If the subtype name denotes an incomplete type
2199 -- an error was already reported by Process_Subtype.
2201 when E_Incomplete_Type =>
2202 Set_Etype (Id, Any_Type);
2205 raise Program_Error;
2209 if Etype (Id) = Any_Type then
2213 -- Some common processing on all types
2215 Set_Size_Info (Id, T);
2216 Set_First_Rep_Item (Id, First_Rep_Item (T));
2220 Set_Is_Immediately_Visible (Id, True);
2221 Set_Depends_On_Private (Id, Has_Private_Component (T));
2223 if Present (Generic_Parent_Type (N))
2226 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
2228 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
2229 /= N_Formal_Private_Type_Definition)
2231 if Is_Tagged_Type (Id) then
2232 if Is_Class_Wide_Type (Id) then
2233 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
2235 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
2238 elsif Scope (Etype (Id)) /= Standard_Standard then
2239 Derive_Subprograms (Generic_Parent_Type (N), Id);
2243 if Is_Private_Type (T)
2244 and then Present (Full_View (T))
2246 Conditional_Delay (Id, Full_View (T));
2248 -- The subtypes of components or subcomponents of protected types
2249 -- do not need freeze nodes, which would otherwise appear in the
2250 -- wrong scope (before the freeze node for the protected type). The
2251 -- proper subtypes are those of the subcomponents of the corresponding
2254 elsif Ekind (Scope (Id)) /= E_Protected_Type
2255 and then Present (Scope (Scope (Id))) -- error defense!
2256 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
2258 Conditional_Delay (Id, T);
2261 -- Check that constraint_error is raised for a scalar subtype
2262 -- indication when the lower or upper bound of a non-null range
2263 -- lies outside the range of the type mark.
2265 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
2266 if Is_Scalar_Type (Etype (Id))
2267 and then Scalar_Range (Id) /=
2268 Scalar_Range (Etype (Subtype_Mark
2269 (Subtype_Indication (N))))
2273 Etype (Subtype_Mark (Subtype_Indication (N))));
2275 elsif Is_Array_Type (Etype (Id))
2276 and then Present (First_Index (Id))
2278 -- This really should be a subprogram that finds the indications
2281 if ((Nkind (First_Index (Id)) = N_Identifier
2282 and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
2283 or else Nkind (First_Index (Id)) = N_Subtype_Indication)
2285 Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
2288 Target_Typ : Entity_Id :=
2291 (Etype (Subtype_Mark (Subtype_Indication (N)))));
2295 (Scalar_Range (Etype (First_Index (Id))),
2297 Etype (First_Index (Id)),
2298 Defining_Identifier (N));
2304 Sloc (Defining_Identifier (N)));
2310 Check_Eliminated (Id);
2311 end Analyze_Subtype_Declaration;
2313 --------------------------------
2314 -- Analyze_Subtype_Indication --
2315 --------------------------------
2317 procedure Analyze_Subtype_Indication (N : Node_Id) is
2318 T : constant Entity_Id := Subtype_Mark (N);
2319 R : constant Node_Id := Range_Expression (Constraint (N));
2326 Set_Etype (N, Etype (R));
2328 Set_Error_Posted (R);
2329 Set_Error_Posted (T);
2331 end Analyze_Subtype_Indication;
2333 ------------------------------
2334 -- Analyze_Type_Declaration --
2335 ------------------------------
2337 procedure Analyze_Type_Declaration (N : Node_Id) is
2338 Def : constant Node_Id := Type_Definition (N);
2339 Def_Id : constant Entity_Id := Defining_Identifier (N);
2344 Prev := Find_Type_Name (N);
2346 if Ekind (Prev) = E_Incomplete_Type then
2347 T := Full_View (Prev);
2352 Set_Is_Pure (T, Is_Pure (Current_Scope));
2354 -- We set the flag Is_First_Subtype here. It is needed to set the
2355 -- corresponding flag for the Implicit class-wide-type created
2356 -- during tagged types processing.
2358 Set_Is_First_Subtype (T, True);
2360 -- Only composite types other than array types are allowed to have
2365 -- For derived types, the rule will be checked once we've figured
2366 -- out the parent type.
2368 when N_Derived_Type_Definition =>
2371 -- For record types, discriminants are allowed.
2373 when N_Record_Definition =>
2377 if Present (Discriminant_Specifications (N)) then
2379 ("elementary or array type cannot have discriminants",
2381 (First (Discriminant_Specifications (N))));
2385 -- Elaborate the type definition according to kind, and generate
2386 -- susbsidiary (implicit) subtypes where needed. We skip this if
2387 -- it was already done (this happens during the reanalysis that
2388 -- follows a call to the high level optimizer).
2390 if not Analyzed (T) then
2395 when N_Access_To_Subprogram_Definition =>
2396 Access_Subprogram_Declaration (T, Def);
2398 -- If this is a remote access to subprogram, we must create
2399 -- the equivalent fat pointer type, and related subprograms.
2401 if Is_Remote_Types (Current_Scope)
2402 or else Is_Remote_Call_Interface (Current_Scope)
2404 Validate_Remote_Access_To_Subprogram_Type (N);
2405 Process_Remote_AST_Declaration (N);
2408 -- Validate categorization rule against access type declaration
2409 -- usually a violation in Pure unit, Shared_Passive unit.
2411 Validate_Access_Type_Declaration (T, N);
2413 when N_Access_To_Object_Definition =>
2414 Access_Type_Declaration (T, Def);
2416 -- Validate categorization rule against access type declaration
2417 -- usually a violation in Pure unit, Shared_Passive unit.
2419 Validate_Access_Type_Declaration (T, N);
2421 -- If we are in a Remote_Call_Interface package and define
2422 -- a RACW, Read and Write attribute must be added.
2424 if (Is_Remote_Call_Interface (Current_Scope)
2425 or else Is_Remote_Types (Current_Scope))
2426 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2428 Add_RACW_Features (Def_Id);
2431 when N_Array_Type_Definition =>
2432 Array_Type_Declaration (T, Def);
2434 when N_Derived_Type_Definition =>
2435 Derived_Type_Declaration (T, N, T /= Def_Id);
2437 when N_Enumeration_Type_Definition =>
2438 Enumeration_Type_Declaration (T, Def);
2440 when N_Floating_Point_Definition =>
2441 Floating_Point_Type_Declaration (T, Def);
2443 when N_Decimal_Fixed_Point_Definition =>
2444 Decimal_Fixed_Point_Type_Declaration (T, Def);
2446 when N_Ordinary_Fixed_Point_Definition =>
2447 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2449 when N_Signed_Integer_Type_Definition =>
2450 Signed_Integer_Type_Declaration (T, Def);
2452 when N_Modular_Type_Definition =>
2453 Modular_Type_Declaration (T, Def);
2455 when N_Record_Definition =>
2456 Record_Type_Declaration (T, N);
2459 raise Program_Error;
2464 if Etype (T) = Any_Type then
2468 -- Some common processing for all types
2470 Set_Depends_On_Private (T, Has_Private_Component (T));
2472 -- Both the declared entity, and its anonymous base type if one
2473 -- was created, need freeze nodes allocated.
2476 B : constant Entity_Id := Base_Type (T);
2479 -- In the case where the base type is different from the first
2480 -- subtype, we pre-allocate a freeze node, and set the proper
2481 -- link to the first subtype. Freeze_Entity will use this
2482 -- preallocated freeze node when it freezes the entity.
2485 Ensure_Freeze_Node (B);
2486 Set_First_Subtype_Link (Freeze_Node (B), T);
2489 if not From_With_Type (T) then
2490 Set_Has_Delayed_Freeze (T);
2494 -- Case of T is the full declaration of some private type which has
2495 -- been swapped in Defining_Identifier (N).
2497 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2498 Process_Full_View (N, T, Def_Id);
2500 -- Record the reference. The form of this is a little strange,
2501 -- since the full declaration has been swapped in. So the first
2502 -- parameter here represents the entity to which a reference is
2503 -- made which is the "real" entity, i.e. the one swapped in,
2504 -- and the second parameter provides the reference location.
2506 Generate_Reference (T, T, 'c');
2508 -- If in main unit, set as referenced, so we do not complain about
2509 -- the full declaration being an unreferenced entity.
2511 if In_Extended_Main_Source_Unit (Def_Id) then
2512 Set_Referenced (Def_Id);
2515 -- For completion of incomplete type, process incomplete dependents
2516 -- and always mark the full type as referenced (it is the incomplete
2517 -- type that we get for any real reference).
2519 elsif Ekind (Prev) = E_Incomplete_Type then
2520 Process_Incomplete_Dependents (N, T, Prev);
2521 Generate_Reference (Prev, Def_Id, 'c');
2523 -- If in main unit, set as referenced, so we do not complain about
2524 -- the full declaration being an unreferenced entity.
2526 if In_Extended_Main_Source_Unit (Def_Id) then
2527 Set_Referenced (Def_Id);
2530 -- If not private type or incomplete type completion, this is a real
2531 -- definition of a new entity, so record it.
2534 Generate_Definition (Def_Id);
2537 Check_Eliminated (Def_Id);
2538 end Analyze_Type_Declaration;
2540 --------------------------
2541 -- Analyze_Variant_Part --
2542 --------------------------
2544 procedure Analyze_Variant_Part (N : Node_Id) is
2546 procedure Non_Static_Choice_Error (Choice : Node_Id);
2547 -- Error routine invoked by the generic instantiation below when
2548 -- the variant part has a non static choice.
2550 procedure Process_Declarations (Variant : Node_Id);
2551 -- Analyzes all the declarations associated with a Variant.
2552 -- Needed by the generic instantiation below.
2554 package Variant_Choices_Processing is new
2555 Generic_Choices_Processing
2556 (Get_Alternatives => Variants,
2557 Get_Choices => Discrete_Choices,
2558 Process_Empty_Choice => No_OP,
2559 Process_Non_Static_Choice => Non_Static_Choice_Error,
2560 Process_Associated_Node => Process_Declarations);
2561 use Variant_Choices_Processing;
2562 -- Instantiation of the generic choice processing package.
2564 -----------------------------
2565 -- Non_Static_Choice_Error --
2566 -----------------------------
2568 procedure Non_Static_Choice_Error (Choice : Node_Id) is
2570 Error_Msg_N ("choice given in variant part is not static", Choice);
2571 end Non_Static_Choice_Error;
2573 --------------------------
2574 -- Process_Declarations --
2575 --------------------------
2577 procedure Process_Declarations (Variant : Node_Id) is
2579 if not Null_Present (Component_List (Variant)) then
2580 Analyze_Declarations (Component_Items (Component_List (Variant)));
2582 if Present (Variant_Part (Component_List (Variant))) then
2583 Analyze (Variant_Part (Component_List (Variant)));
2586 end Process_Declarations;
2588 -- Variables local to Analyze_Case_Statement.
2590 Others_Choice : Node_Id;
2592 Discr_Name : Node_Id;
2593 Discr_Type : Entity_Id;
2595 Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
2597 Dont_Care : Boolean;
2598 Others_Present : Boolean := False;
2600 -- Start of processing for Analyze_Variant_Part
2603 Discr_Name := Name (N);
2604 Analyze (Discr_Name);
2606 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
2607 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
2610 Discr_Type := Etype (Entity (Discr_Name));
2612 if not Is_Discrete_Type (Discr_Type) then
2614 ("discriminant in a variant part must be of a discrete type",
2619 -- Call the instantiated Analyze_Choices which does the rest of the work
2622 (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
2624 if Others_Present then
2625 -- Fill in Others_Discrete_Choices field of the OTHERS choice
2627 Others_Choice := First (Discrete_Choices (Last (Variants (N))));
2628 Expand_Others_Choice
2629 (Case_Table (1 .. Last_Choice), Others_Choice, Discr_Type);
2632 end Analyze_Variant_Part;
2634 ----------------------------
2635 -- Array_Type_Declaration --
2636 ----------------------------
2638 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
2639 Component_Def : constant Node_Id := Subtype_Indication (Def);
2640 Element_Type : Entity_Id;
2641 Implicit_Base : Entity_Id;
2643 Related_Id : Entity_Id := Empty;
2645 P : constant Node_Id := Parent (Def);
2649 if Nkind (Def) = N_Constrained_Array_Definition then
2651 Index := First (Discrete_Subtype_Definitions (Def));
2653 -- Find proper names for the implicit types which may be public.
2654 -- in case of anonymous arrays we use the name of the first object
2655 -- of that type as prefix.
2658 Related_Id := Defining_Identifier (P);
2664 Index := First (Subtype_Marks (Def));
2669 while Present (Index) loop
2671 Make_Index (Index, P, Related_Id, Nb_Index);
2673 Nb_Index := Nb_Index + 1;
2676 Element_Type := Process_Subtype (Component_Def, P, Related_Id, 'C');
2678 -- Constrained array case
2681 T := Create_Itype (E_Void, P, Related_Id, 'T');
2684 if Nkind (Def) = N_Constrained_Array_Definition then
2686 -- Establish Implicit_Base as unconstrained base type
2688 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
2690 Init_Size_Align (Implicit_Base);
2691 Set_Etype (Implicit_Base, Implicit_Base);
2692 Set_Scope (Implicit_Base, Current_Scope);
2693 Set_Has_Delayed_Freeze (Implicit_Base);
2695 -- The constrained array type is a subtype of the unconstrained one
2697 Set_Ekind (T, E_Array_Subtype);
2698 Init_Size_Align (T);
2699 Set_Etype (T, Implicit_Base);
2700 Set_Scope (T, Current_Scope);
2701 Set_Is_Constrained (T, True);
2702 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
2703 Set_Has_Delayed_Freeze (T);
2705 -- Complete setup of implicit base type
2707 Set_First_Index (Implicit_Base, First_Index (T));
2708 Set_Component_Type (Implicit_Base, Element_Type);
2709 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
2710 Set_Component_Size (Implicit_Base, Uint_0);
2711 Set_Has_Controlled_Component (Implicit_Base,
2712 Has_Controlled_Component (Element_Type)
2713 or else Is_Controlled (Element_Type));
2714 Set_Finalize_Storage_Only (Implicit_Base,
2715 Finalize_Storage_Only (Element_Type));
2717 -- Unconstrained array case
2720 Set_Ekind (T, E_Array_Type);
2721 Init_Size_Align (T);
2723 Set_Scope (T, Current_Scope);
2724 Set_Component_Size (T, Uint_0);
2725 Set_Is_Constrained (T, False);
2726 Set_First_Index (T, First (Subtype_Marks (Def)));
2727 Set_Has_Delayed_Freeze (T, True);
2728 Set_Has_Task (T, Has_Task (Element_Type));
2729 Set_Has_Controlled_Component (T,
2730 Has_Controlled_Component (Element_Type)
2731 or else Is_Controlled (Element_Type));
2732 Set_Finalize_Storage_Only (T,
2733 Finalize_Storage_Only (Element_Type));
2736 Set_Component_Type (T, Element_Type);
2738 if Aliased_Present (Def) then
2739 Set_Has_Aliased_Components (Etype (T));
2742 Priv := Private_Component (Element_Type);
2744 if Present (Priv) then
2745 -- Check for circular definitions.
2747 if Priv = Any_Type then
2748 Set_Component_Type (T, Any_Type);
2749 Set_Component_Type (Etype (T), Any_Type);
2751 -- There is a gap in the visiblity of operations on the composite
2752 -- type only if the component type is defined in a different scope.
2754 elsif Scope (Priv) = Current_Scope then
2757 elsif Is_Limited_Type (Priv) then
2758 Set_Is_Limited_Composite (Etype (T));
2759 Set_Is_Limited_Composite (T);
2761 Set_Is_Private_Composite (Etype (T));
2762 Set_Is_Private_Composite (T);
2766 -- Create a concatenation operator for the new type. Internal
2767 -- array types created for packed entities do not need such, they
2768 -- are compatible with the user-defined type.
2770 if Number_Dimensions (T) = 1
2771 and then not Is_Packed_Array_Type (T)
2773 New_Binary_Operator (Name_Op_Concat, T);
2776 -- In the case of an unconstrained array the parser has already
2777 -- verified that all the indices are unconstrained but we still
2778 -- need to make sure that the element type is constrained.
2780 if Is_Indefinite_Subtype (Element_Type) then
2782 ("unconstrained element type in array declaration ",
2785 elsif Is_Abstract (Element_Type) then
2786 Error_Msg_N ("The type of a component cannot be abstract ",
2790 end Array_Type_Declaration;
2792 -------------------------------
2793 -- Build_Derived_Access_Type --
2794 -------------------------------
2796 procedure Build_Derived_Access_Type
2798 Parent_Type : Entity_Id;
2799 Derived_Type : Entity_Id)
2801 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
2803 Desig_Type : Entity_Id;
2805 Discr_Con_Elist : Elist_Id;
2806 Discr_Con_El : Elmt_Id;
2811 -- Set the designated type so it is available in case this is
2812 -- an access to a self-referential type, e.g. a standard list
2813 -- type with a next pointer. Will be reset after subtype is built.
2815 Set_Directly_Designated_Type (Derived_Type,
2816 Designated_Type (Parent_Type));
2818 Subt := Process_Subtype (S, N);
2820 if Nkind (S) /= N_Subtype_Indication
2821 and then Subt /= Base_Type (Subt)
2823 Set_Ekind (Derived_Type, E_Access_Subtype);
2826 if Ekind (Derived_Type) = E_Access_Subtype then
2828 Pbase : constant Entity_Id := Base_Type (Parent_Type);
2829 Ibase : constant Entity_Id :=
2830 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
2831 Svg_Chars : constant Name_Id := Chars (Ibase);
2832 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
2835 Copy_Node (Pbase, Ibase);
2837 Set_Chars (Ibase, Svg_Chars);
2838 Set_Next_Entity (Ibase, Svg_Next_E);
2839 Set_Sloc (Ibase, Sloc (Derived_Type));
2840 Set_Scope (Ibase, Scope (Derived_Type));
2841 Set_Freeze_Node (Ibase, Empty);
2842 Set_Is_Frozen (Ibase, False);
2844 Set_Etype (Ibase, Pbase);
2845 Set_Etype (Derived_Type, Ibase);
2849 Set_Directly_Designated_Type
2850 (Derived_Type, Designated_Type (Subt));
2852 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
2853 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
2854 Set_Size_Info (Derived_Type, Parent_Type);
2855 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
2856 Set_Depends_On_Private (Derived_Type,
2857 Has_Private_Component (Derived_Type));
2858 Conditional_Delay (Derived_Type, Subt);
2860 -- Note: we do not copy the Storage_Size_Variable, since
2861 -- we always go to the root type for this information.
2863 -- Apply range checks to discriminants for derived record case
2864 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
2866 Desig_Type := Designated_Type (Derived_Type);
2867 if Is_Composite_Type (Desig_Type)
2868 and then (not Is_Array_Type (Desig_Type))
2869 and then Has_Discriminants (Desig_Type)
2870 and then Base_Type (Desig_Type) /= Desig_Type
2872 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
2873 Discr_Con_El := First_Elmt (Discr_Con_Elist);
2875 Discr := First_Discriminant (Base_Type (Desig_Type));
2876 while Present (Discr_Con_El) loop
2877 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
2878 Next_Elmt (Discr_Con_El);
2879 Next_Discriminant (Discr);
2882 end Build_Derived_Access_Type;
2884 ------------------------------
2885 -- Build_Derived_Array_Type --
2886 ------------------------------
2888 procedure Build_Derived_Array_Type
2890 Parent_Type : Entity_Id;
2891 Derived_Type : Entity_Id)
2893 Loc : constant Source_Ptr := Sloc (N);
2894 Tdef : constant Node_Id := Type_Definition (N);
2895 Indic : constant Node_Id := Subtype_Indication (Tdef);
2896 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
2897 Implicit_Base : Entity_Id;
2898 New_Indic : Node_Id;
2900 procedure Make_Implicit_Base;
2901 -- If the parent subtype is constrained, the derived type is a
2902 -- subtype of an implicit base type derived from the parent base.
2904 ------------------------
2905 -- Make_Implicit_Base --
2906 ------------------------
2908 procedure Make_Implicit_Base is
2911 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
2913 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
2914 Set_Etype (Implicit_Base, Parent_Base);
2916 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
2917 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
2919 Set_Has_Delayed_Freeze (Implicit_Base, True);
2920 end Make_Implicit_Base;
2922 -- Start of processing for Build_Derived_Array_Type
2925 if not Is_Constrained (Parent_Type) then
2926 if Nkind (Indic) /= N_Subtype_Indication then
2927 Set_Ekind (Derived_Type, E_Array_Type);
2929 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
2930 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
2932 Set_Has_Delayed_Freeze (Derived_Type, True);
2936 Set_Etype (Derived_Type, Implicit_Base);
2939 Make_Subtype_Declaration (Loc,
2940 Defining_Identifier => Derived_Type,
2941 Subtype_Indication =>
2942 Make_Subtype_Indication (Loc,
2943 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
2944 Constraint => Constraint (Indic)));
2946 Rewrite (N, New_Indic);
2951 if Nkind (Indic) /= N_Subtype_Indication then
2954 Set_Ekind (Derived_Type, Ekind (Parent_Type));
2955 Set_Etype (Derived_Type, Implicit_Base);
2956 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
2959 Error_Msg_N ("illegal constraint on constrained type", Indic);
2963 -- If the parent type is not a derived type itself, and is
2964 -- declared in a closed scope (e.g., a subprogram), then we
2965 -- need to explicitly introduce the new type's concatenation
2966 -- operator since Derive_Subprograms will not inherit the
2967 -- parent's operator.
2969 if Number_Dimensions (Parent_Type) = 1
2970 and then not Is_Limited_Type (Parent_Type)
2971 and then not Is_Derived_Type (Parent_Type)
2972 and then not Is_Package (Scope (Base_Type (Parent_Type)))
2974 New_Binary_Operator (Name_Op_Concat, Derived_Type);
2976 end Build_Derived_Array_Type;
2978 -----------------------------------
2979 -- Build_Derived_Concurrent_Type --
2980 -----------------------------------
2982 procedure Build_Derived_Concurrent_Type
2984 Parent_Type : Entity_Id;
2985 Derived_Type : Entity_Id)
2987 D_Constraint : Node_Id;
2988 Disc_Spec : Node_Id;
2989 Old_Disc : Entity_Id;
2990 New_Disc : Entity_Id;
2992 Constraint_Present : constant Boolean :=
2993 Nkind (Subtype_Indication (Type_Definition (N)))
2994 = N_Subtype_Indication;
2997 Set_Girder_Constraint (Derived_Type, No_Elist);
2999 if Is_Task_Type (Parent_Type) then
3000 Set_Storage_Size_Variable (Derived_Type,
3001 Storage_Size_Variable (Parent_Type));
3004 if Present (Discriminant_Specifications (N)) then
3005 New_Scope (Derived_Type);
3006 Check_Or_Process_Discriminants (N, Derived_Type);
3009 elsif Constraint_Present then
3011 -- Build constrained subtype and derive from it
3014 Loc : constant Source_Ptr := Sloc (N);
3016 Make_Defining_Identifier (Loc,
3017 New_External_Name (Chars (Derived_Type), 'T'));
3022 Make_Subtype_Declaration (Loc,
3023 Defining_Identifier => Anon,
3024 Subtype_Indication =>
3025 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
3026 Insert_Before (N, Decl);
3027 Rewrite (Subtype_Indication (Type_Definition (N)),
3028 New_Occurrence_Of (Anon, Loc));
3030 Set_Analyzed (Derived_Type, False);
3036 -- All attributes are inherited from parent. In particular,
3037 -- entries and the corresponding record type are the same.
3038 -- Discriminants may be renamed, and must be treated separately.
3040 Set_Has_Discriminants
3041 (Derived_Type, Has_Discriminants (Parent_Type));
3042 Set_Corresponding_Record_Type
3043 (Derived_Type, Corresponding_Record_Type (Parent_Type));
3045 if Constraint_Present then
3047 if not Has_Discriminants (Parent_Type) then
3048 Error_Msg_N ("untagged parent must have discriminants", N);
3050 elsif Present (Discriminant_Specifications (N)) then
3052 -- Verify that new discriminants are used to constrain
3055 Old_Disc := First_Discriminant (Parent_Type);
3056 New_Disc := First_Discriminant (Derived_Type);
3057 Disc_Spec := First (Discriminant_Specifications (N));
3061 (Constraint (Subtype_Indication (Type_Definition (N)))));
3063 while Present (Old_Disc) and then Present (Disc_Spec) loop
3065 if Nkind (Discriminant_Type (Disc_Spec)) /=
3068 Analyze (Discriminant_Type (Disc_Spec));
3070 if not Subtypes_Statically_Compatible (
3071 Etype (Discriminant_Type (Disc_Spec)),
3075 ("not statically compatible with parent discriminant",
3076 Discriminant_Type (Disc_Spec));
3080 if Nkind (D_Constraint) = N_Identifier
3081 and then Chars (D_Constraint) /=
3082 Chars (Defining_Identifier (Disc_Spec))
3084 Error_Msg_N ("new discriminants must constrain old ones",
3087 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
3090 Next_Discriminant (Old_Disc);
3091 Next_Discriminant (New_Disc);
3095 if Present (Old_Disc) or else Present (Disc_Spec) then
3096 Error_Msg_N ("discriminant mismatch in derivation", N);
3101 elsif Present (Discriminant_Specifications (N)) then
3103 ("missing discriminant constraint in untagged derivation",
3107 if Present (Discriminant_Specifications (N)) then
3109 Old_Disc := First_Discriminant (Parent_Type);
3111 while Present (Old_Disc) loop
3113 if No (Next_Entity (Old_Disc))
3114 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
3116 Set_Next_Entity (Last_Entity (Derived_Type),
3117 Next_Entity (Old_Disc));
3121 Next_Discriminant (Old_Disc);
3125 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
3126 if Has_Discriminants (Parent_Type) then
3127 Set_Discriminant_Constraint (
3128 Derived_Type, Discriminant_Constraint (Parent_Type));
3132 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
3134 Set_Has_Completion (Derived_Type);
3135 end Build_Derived_Concurrent_Type;
3137 ------------------------------------
3138 -- Build_Derived_Enumeration_Type --
3139 ------------------------------------
3141 procedure Build_Derived_Enumeration_Type
3143 Parent_Type : Entity_Id;
3144 Derived_Type : Entity_Id)
3146 Loc : constant Source_Ptr := Sloc (N);
3147 Def : constant Node_Id := Type_Definition (N);
3148 Indic : constant Node_Id := Subtype_Indication (Def);
3149 Implicit_Base : Entity_Id;
3150 Literal : Entity_Id;
3151 New_Lit : Entity_Id;
3152 Literals_List : List_Id;
3153 Type_Decl : Node_Id;
3155 Rang_Expr : Node_Id;
3158 -- Since types Standard.Character and Standard.Wide_Character do
3159 -- not have explicit literals lists we need to process types derived
3160 -- from them specially. This is handled by Derived_Standard_Character.
3161 -- If the parent type is a generic type, there are no literals either,
3162 -- and we construct the same skeletal representation as for the generic
3165 if Root_Type (Parent_Type) = Standard_Character
3166 or else Root_Type (Parent_Type) = Standard_Wide_Character
3168 Derived_Standard_Character (N, Parent_Type, Derived_Type);
3170 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
3177 Make_Attribute_Reference (Loc,
3178 Attribute_Name => Name_First,
3179 Prefix => New_Reference_To (Derived_Type, Loc));
3180 Set_Etype (Lo, Derived_Type);
3183 Make_Attribute_Reference (Loc,
3184 Attribute_Name => Name_Last,
3185 Prefix => New_Reference_To (Derived_Type, Loc));
3186 Set_Etype (Hi, Derived_Type);
3188 Set_Scalar_Range (Derived_Type,
3195 -- If a constraint is present, analyze the bounds to catch
3196 -- premature usage of the derived literals.
3198 if Nkind (Indic) = N_Subtype_Indication
3199 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
3201 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
3202 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
3205 -- Introduce an implicit base type for the derived type even
3206 -- if there is no constraint attached to it, since this seems
3207 -- closer to the Ada semantics. Build a full type declaration
3208 -- tree for the derived type using the implicit base type as
3209 -- the defining identifier. The build a subtype declaration
3210 -- tree which applies the constraint (if any) have it replace
3211 -- the derived type declaration.
3213 Literal := First_Literal (Parent_Type);
3214 Literals_List := New_List;
3216 while Present (Literal)
3217 and then Ekind (Literal) = E_Enumeration_Literal
3219 -- Literals of the derived type have the same representation as
3220 -- those of the parent type, but this representation can be
3221 -- overridden by an explicit representation clause. Indicate
3222 -- that there is no explicit representation given yet. These
3223 -- derived literals are implicit operations of the new type,
3224 -- and can be overriden by explicit ones.
3226 if Nkind (Literal) = N_Defining_Character_Literal then
3228 Make_Defining_Character_Literal (Loc, Chars (Literal));
3230 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
3233 Set_Ekind (New_Lit, E_Enumeration_Literal);
3234 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
3235 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
3236 Set_Enumeration_Rep_Expr (New_Lit, Empty);
3237 Set_Alias (New_Lit, Literal);
3238 Set_Is_Known_Valid (New_Lit, True);
3240 Append (New_Lit, Literals_List);
3241 Next_Literal (Literal);
3245 Make_Defining_Identifier (Sloc (Derived_Type),
3246 New_External_Name (Chars (Derived_Type), 'B'));
3248 -- Indicate the proper nature of the derived type. This must
3249 -- be done before analysis of the literals, to recognize cases
3250 -- when a literal may be hidden by a previous explicit function
3251 -- definition (cf. c83031a).
3253 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
3254 Set_Etype (Derived_Type, Implicit_Base);
3257 Make_Full_Type_Declaration (Loc,
3258 Defining_Identifier => Implicit_Base,
3259 Discriminant_Specifications => No_List,
3261 Make_Enumeration_Type_Definition (Loc, Literals_List));
3263 Mark_Rewrite_Insertion (Type_Decl);
3264 Insert_Before (N, Type_Decl);
3265 Analyze (Type_Decl);
3267 -- After the implicit base is analyzed its Etype needs to be
3268 -- changed to reflect the fact that it is derived from the
3269 -- parent type which was ignored during analysis. We also set
3270 -- the size at this point.
3272 Set_Etype (Implicit_Base, Parent_Type);
3274 Set_Size_Info (Implicit_Base, Parent_Type);
3275 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
3276 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
3278 Set_Has_Non_Standard_Rep
3279 (Implicit_Base, Has_Non_Standard_Rep
3281 Set_Has_Delayed_Freeze (Implicit_Base);
3283 -- Process the subtype indication including a validation check
3284 -- on the constraint, if any. If a constraint is given, its bounds
3285 -- must be implicitly converted to the new type.
3287 if Nkind (Indic) = N_Subtype_Indication then
3290 R : constant Node_Id :=
3291 Range_Expression (Constraint (Indic));
3294 if Nkind (R) = N_Range then
3295 Hi := Build_Scalar_Bound
3296 (High_Bound (R), Parent_Type, Implicit_Base, Loc);
3297 Lo := Build_Scalar_Bound
3298 (Low_Bound (R), Parent_Type, Implicit_Base, Loc);
3301 -- Constraint is a Range attribute. Replace with the
3302 -- explicit mention of the bounds of the prefix, which
3303 -- must be a subtype.
3305 Analyze (Prefix (R));
3307 Convert_To (Implicit_Base,
3308 Make_Attribute_Reference (Loc,
3309 Attribute_Name => Name_Last,
3311 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3314 Convert_To (Implicit_Base,
3315 Make_Attribute_Reference (Loc,
3316 Attribute_Name => Name_First,
3318 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3326 (Type_High_Bound (Parent_Type),
3327 Parent_Type, Implicit_Base, Loc);
3330 (Type_Low_Bound (Parent_Type),
3331 Parent_Type, Implicit_Base, Loc);
3339 -- If we constructed a default range for the case where no range
3340 -- was given, then the expressions in the range must not freeze
3341 -- since they do not correspond to expressions in the source.
3343 if Nkind (Indic) /= N_Subtype_Indication then
3344 Set_Must_Not_Freeze (Lo);
3345 Set_Must_Not_Freeze (Hi);
3346 Set_Must_Not_Freeze (Rang_Expr);
3350 Make_Subtype_Declaration (Loc,
3351 Defining_Identifier => Derived_Type,
3352 Subtype_Indication =>
3353 Make_Subtype_Indication (Loc,
3354 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
3356 Make_Range_Constraint (Loc,
3357 Range_Expression => Rang_Expr))));
3361 -- If pragma Discard_Names applies on the first subtype
3362 -- of the parent type, then it must be applied on this
3365 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
3366 Set_Discard_Names (Derived_Type);
3369 -- Apply a range check. Since this range expression doesn't
3370 -- have an Etype, we have to specifically pass the Source_Typ
3371 -- parameter. Is this right???
3373 if Nkind (Indic) = N_Subtype_Indication then
3374 Apply_Range_Check (Range_Expression (Constraint (Indic)),
3376 Source_Typ => Entity (Subtype_Mark (Indic)));
3380 end Build_Derived_Enumeration_Type;
3382 --------------------------------
3383 -- Build_Derived_Numeric_Type --
3384 --------------------------------
3386 procedure Build_Derived_Numeric_Type
3388 Parent_Type : Entity_Id;
3389 Derived_Type : Entity_Id)
3391 Loc : constant Source_Ptr := Sloc (N);
3392 Tdef : constant Node_Id := Type_Definition (N);
3393 Indic : constant Node_Id := Subtype_Indication (Tdef);
3394 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3395 No_Constraint : constant Boolean := Nkind (Indic) /=
3396 N_Subtype_Indication;
3397 Implicit_Base : Entity_Id;
3404 -- Process the subtype indication including a validation check on
3405 -- the constraint if any.
3407 T := Process_Subtype (Indic, N);
3409 -- Introduce an implicit base type for the derived type even if
3410 -- there is no constraint attached to it, since this seems closer
3411 -- to the Ada semantics.
3414 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3416 Set_Etype (Implicit_Base, Parent_Base);
3417 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3418 Set_Size_Info (Implicit_Base, Parent_Base);
3419 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3420 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
3421 Set_Parent (Implicit_Base, Parent (Derived_Type));
3423 if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
3424 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3427 Set_Has_Delayed_Freeze (Implicit_Base);
3429 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
3430 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
3432 Set_Scalar_Range (Implicit_Base,
3437 if Has_Infinities (Parent_Base) then
3438 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
3441 -- The Derived_Type, which is the entity of the declaration, is
3442 -- a subtype of the implicit base. Its Ekind is a subtype, even
3443 -- in the absence of an explicit constraint.
3445 Set_Etype (Derived_Type, Implicit_Base);
3447 -- If we did not have a constraint, then the Ekind is set from the
3448 -- parent type (otherwise Process_Subtype has set the bounds)
3450 if No_Constraint then
3451 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
3454 -- If we did not have a range constraint, then set the range
3455 -- from the parent type. Otherwise, the call to Process_Subtype
3456 -- has set the bounds.
3459 or else not Has_Range_Constraint (Indic)
3461 Set_Scalar_Range (Derived_Type,
3463 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
3464 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
3465 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3467 if Has_Infinities (Parent_Type) then
3468 Set_Includes_Infinities (Scalar_Range (Derived_Type));
3472 -- Set remaining type-specific fields, depending on numeric type
3474 if Is_Modular_Integer_Type (Parent_Type) then
3475 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
3477 Set_Non_Binary_Modulus
3478 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
3480 elsif Is_Floating_Point_Type (Parent_Type) then
3482 -- Digits of base type is always copied from the digits value of
3483 -- the parent base type, but the digits of the derived type will
3484 -- already have been set if there was a constraint present.
3486 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3487 Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
3489 if No_Constraint then
3490 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
3493 elsif Is_Fixed_Point_Type (Parent_Type) then
3495 -- Small of base type and derived type are always copied from
3496 -- the parent base type, since smalls never change. The delta
3497 -- of the base type is also copied from the parent base type.
3498 -- However the delta of the derived type will have been set
3499 -- already if a constraint was present.
3501 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
3502 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
3503 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
3505 if No_Constraint then
3506 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
3509 -- The scale and machine radix in the decimal case are always
3510 -- copied from the parent base type.
3512 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
3513 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
3514 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
3516 Set_Machine_Radix_10
3517 (Derived_Type, Machine_Radix_10 (Parent_Base));
3518 Set_Machine_Radix_10
3519 (Implicit_Base, Machine_Radix_10 (Parent_Base));
3521 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3523 if No_Constraint then
3524 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
3527 -- the analysis of the subtype_indication sets the
3528 -- digits value of the derived type.
3535 -- The type of the bounds is that of the parent type, and they
3536 -- must be converted to the derived type.
3538 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
3540 -- The implicit_base should be frozen when the derived type is frozen,
3541 -- but note that it is used in the conversions of the bounds. For
3542 -- fixed types we delay the determination of the bounds until the proper
3543 -- freezing point. For other numeric types this is rejected by GCC, for
3544 -- reasons that are currently unclear (???), so we choose to freeze the
3545 -- implicit base now. In the case of integers and floating point types
3546 -- this is harmless because subsequent representation clauses cannot
3547 -- affect anything, but it is still baffling that we cannot use the
3548 -- same mechanism for all derived numeric types.
3550 if Is_Fixed_Point_Type (Parent_Type) then
3551 Conditional_Delay (Implicit_Base, Parent_Type);
3553 Freeze_Before (N, Implicit_Base);
3556 end Build_Derived_Numeric_Type;
3558 --------------------------------
3559 -- Build_Derived_Private_Type --
3560 --------------------------------
3562 procedure Build_Derived_Private_Type
3564 Parent_Type : Entity_Id;
3565 Derived_Type : Entity_Id;
3566 Is_Completion : Boolean;
3567 Derive_Subps : Boolean := True)
3569 Der_Base : Entity_Id;
3571 Full_Decl : Node_Id := Empty;
3572 Full_Der : Entity_Id;
3574 Last_Discr : Entity_Id;
3575 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
3576 Swapped : Boolean := False;
3578 procedure Copy_And_Build;
3579 -- Copy derived type declaration, replace parent with its full view,
3580 -- and analyze new declaration.
3582 procedure Copy_And_Build is
3586 if Ekind (Parent_Type) in Record_Kind
3587 or else (Ekind (Parent_Type) in Enumeration_Kind
3588 and then Root_Type (Parent_Type) /= Standard_Character
3589 and then Root_Type (Parent_Type) /= Standard_Wide_Character
3590 and then not Is_Generic_Type (Root_Type (Parent_Type)))
3592 Full_N := New_Copy_Tree (N);
3593 Insert_After (N, Full_N);
3594 Build_Derived_Type (
3595 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
3598 Build_Derived_Type (
3599 N, Parent_Type, Full_Der, True, Derive_Subps => False);
3603 -- Start of processing for Build_Derived_Private_Type
3606 if Is_Tagged_Type (Parent_Type) then
3607 Build_Derived_Record_Type
3608 (N, Parent_Type, Derived_Type, Derive_Subps);
3611 elsif Has_Discriminants (Parent_Type) then
3613 if Present (Full_View (Parent_Type)) then
3614 if not Is_Completion then
3616 -- Copy declaration for subsequent analysis.
3618 Full_Decl := New_Copy_Tree (N);
3619 Full_Der := New_Copy (Derived_Type);
3620 Insert_After (N, Full_Decl);
3623 -- If this is a completion, the full view being built is
3624 -- itself private. We build a subtype of the parent with
3625 -- the same constraints as this full view, to convey to the
3626 -- back end the constrained components and the size of this
3627 -- subtype. If the parent is constrained, its full view can
3628 -- serve as the underlying full view of the derived type.
3630 if No (Discriminant_Specifications (N)) then
3632 if Nkind (Subtype_Indication (Type_Definition (N)))
3633 = N_Subtype_Indication
3635 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
3637 elsif Is_Constrained (Full_View (Parent_Type)) then
3638 Set_Underlying_Full_View (Derived_Type,
3639 Full_View (Parent_Type));
3643 -- If there are new discriminants, the parent subtype is
3644 -- constrained by them, but it is not clear how to build
3645 -- the underlying_full_view in this case ???
3652 Build_Derived_Record_Type
3653 (N, Parent_Type, Derived_Type, Derive_Subps);
3655 if Present (Full_View (Parent_Type))
3656 and then not Is_Completion
3658 if not In_Open_Scopes (Par_Scope)
3659 or else not In_Same_Source_Unit (N, Parent_Type)
3661 -- Swap partial and full views temporarily
3663 Install_Private_Declarations (Par_Scope);
3664 Install_Visible_Declarations (Par_Scope);
3668 -- Subprograms have been derived on the private view,
3669 -- the completion does not derive them anew.
3671 Build_Derived_Record_Type
3672 (Full_Decl, Parent_Type, Full_Der, False);
3675 Uninstall_Declarations (Par_Scope);
3677 if In_Open_Scopes (Par_Scope) then
3678 Install_Visible_Declarations (Par_Scope);
3682 Der_Base := Base_Type (Derived_Type);
3683 Set_Full_View (Derived_Type, Full_Der);
3684 Set_Full_View (Der_Base, Base_Type (Full_Der));
3686 -- Copy the discriminant list from full view to
3687 -- the partial views (base type and its subtype).
3688 -- Gigi requires that the partial and full views
3689 -- have the same discriminants.
3690 -- ??? Note that since the partial view is pointing
3691 -- to discriminants in the full view, their scope
3692 -- will be that of the full view. This might
3693 -- cause some front end problems and need
3696 Discr := First_Discriminant (Base_Type (Full_Der));
3697 Set_First_Entity (Der_Base, Discr);
3700 Last_Discr := Discr;
3701 Next_Discriminant (Discr);
3702 exit when No (Discr);
3705 Set_Last_Entity (Der_Base, Last_Discr);
3707 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
3708 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
3711 -- If this is a completion, the derived type stays private
3712 -- and there is no need to create a further full view, except
3713 -- in the unusual case when the derivation is nested within a
3714 -- child unit, see below.
3719 elsif Present (Full_View (Parent_Type))
3720 and then Has_Discriminants (Full_View (Parent_Type))
3722 if Has_Unknown_Discriminants (Parent_Type)
3723 and then Nkind (Subtype_Indication (Type_Definition (N)))
3724 = N_Subtype_Indication
3727 ("cannot constrain type with unknown discriminants",
3728 Subtype_Indication (Type_Definition (N)));
3732 -- Inherit the discriminants of the full view, but
3733 -- keep the proper parent type.
3735 -- ??? this looks wrong, we are replacing (and thus,
3736 -- erasing) the partial view!
3738 -- In any case, the primitive operations are inherited from
3739 -- the parent type, not from the internal full view.
3741 Build_Derived_Record_Type
3742 (N, Full_View (Parent_Type), Derived_Type,
3743 Derive_Subps => False);
3744 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
3746 if Derive_Subps then
3747 Derive_Subprograms (Parent_Type, Derived_Type);
3752 -- Untagged type, No discriminants on either view.
3754 if Nkind (Subtype_Indication (Type_Definition (N)))
3755 = N_Subtype_Indication
3758 ("illegal constraint on type without discriminants", N);
3761 if Present (Discriminant_Specifications (N))
3762 and then Present (Full_View (Parent_Type))
3763 and then not Is_Tagged_Type (Full_View (Parent_Type))
3766 ("cannot add discriminants to untagged type", N);
3769 Set_Girder_Constraint (Derived_Type, No_Elist);
3770 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3771 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
3772 Set_Has_Controlled_Component (Derived_Type,
3773 Has_Controlled_Component (Parent_Type));
3775 -- Direct controlled types do not inherit the Finalize_Storage_Only
3778 if not Is_Controlled (Parent_Type) then
3779 Set_Finalize_Storage_Only (Derived_Type,
3780 Finalize_Storage_Only (Parent_Type));
3783 -- Construct the implicit full view by deriving from full
3784 -- view of the parent type. In order to get proper visiblity,
3785 -- we install the parent scope and its declarations.
3787 -- ??? if the parent is untagged private and its
3788 -- completion is tagged, this mechanism will not
3789 -- work because we cannot derive from the tagged
3790 -- full view unless we have an extension
3792 if Present (Full_View (Parent_Type))
3793 and then not Is_Tagged_Type (Full_View (Parent_Type))
3794 and then not Is_Completion
3796 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
3797 Chars (Derived_Type));
3798 Set_Is_Itype (Full_Der);
3799 Set_Has_Private_Declaration (Full_Der);
3800 Set_Has_Private_Declaration (Derived_Type);
3801 Set_Associated_Node_For_Itype (Full_Der, N);
3802 Set_Parent (Full_Der, Parent (Derived_Type));
3803 Set_Full_View (Derived_Type, Full_Der);
3805 if not In_Open_Scopes (Par_Scope) then
3806 Install_Private_Declarations (Par_Scope);
3807 Install_Visible_Declarations (Par_Scope);
3809 Uninstall_Declarations (Par_Scope);
3811 -- If parent scope is open and in another unit, and
3812 -- parent has a completion, then the derivation is taking
3813 -- place in the visible part of a child unit. In that
3814 -- case retrieve the full view of the parent momentarily.
3816 elsif not In_Same_Source_Unit (N, Parent_Type) then
3817 Full_P := Full_View (Parent_Type);
3818 Exchange_Declarations (Parent_Type);
3820 Exchange_Declarations (Full_P);
3822 -- Otherwise it is a local derivation.
3828 Set_Scope (Full_Der, Current_Scope);
3829 Set_Is_First_Subtype (Full_Der,
3830 Is_First_Subtype (Derived_Type));
3831 Set_Has_Size_Clause (Full_Der, False);
3832 Set_Has_Alignment_Clause (Full_Der, False);
3833 Set_Next_Entity (Full_Der, Empty);
3834 Set_Has_Delayed_Freeze (Full_Der);
3835 Set_Is_Frozen (Full_Der, False);
3836 Set_Freeze_Node (Full_Der, Empty);
3837 Set_Depends_On_Private (Full_Der,
3838 Has_Private_Component (Full_Der));
3839 Set_Public_Status (Full_Der);
3843 Set_Has_Unknown_Discriminants (Derived_Type,
3844 Has_Unknown_Discriminants (Parent_Type));
3846 if Is_Private_Type (Derived_Type) then
3847 Set_Private_Dependents (Derived_Type, New_Elmt_List);
3850 if Is_Private_Type (Parent_Type)
3851 and then Base_Type (Parent_Type) = Parent_Type
3852 and then In_Open_Scopes (Scope (Parent_Type))
3854 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
3856 if Is_Child_Unit (Scope (Current_Scope))
3857 and then Is_Completion
3858 and then In_Private_Part (Current_Scope)
3860 -- This is the unusual case where a type completed by a private
3861 -- derivation occurs within a package nested in a child unit,
3862 -- and the parent is declared in an ancestor. In this case, the
3863 -- full view of the parent type will become visible in the body
3864 -- of the enclosing child, and only then will the current type
3865 -- be possibly non-private. We build a underlying full view that
3866 -- will be installed when the enclosing child body is compiled.
3869 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
3873 Make_Defining_Identifier (Sloc (Derived_Type),
3874 Chars (Derived_Type));
3875 Set_Is_Itype (Full_Der);
3876 Set_Itype (IR, Full_Der);
3877 Insert_After (N, IR);
3879 -- The full view will be used to swap entities on entry/exit
3880 -- to the body, and must appear in the entity list for the
3883 Append_Entity (Full_Der, Scope (Derived_Type));
3884 Set_Has_Private_Declaration (Full_Der);
3885 Set_Has_Private_Declaration (Derived_Type);
3886 Set_Associated_Node_For_Itype (Full_Der, N);
3887 Set_Parent (Full_Der, Parent (Derived_Type));
3888 Full_P := Full_View (Parent_Type);
3889 Exchange_Declarations (Parent_Type);
3891 Exchange_Declarations (Full_P);
3892 Set_Underlying_Full_View (Derived_Type, Full_Der);
3896 end Build_Derived_Private_Type;
3898 -------------------------------
3899 -- Build_Derived_Record_Type --
3900 -------------------------------
3904 -- Ideally we would like to use the same model of type derivation for
3905 -- tagged and untagged record types. Unfortunately this is not quite
3906 -- possible because the semantics of representation clauses is different
3907 -- for tagged and untagged records under inheritance. Consider the
3910 -- type R (...) is [tagged] record ... end record;
3911 -- type T (...) is new R (...) [with ...];
3913 -- The representation clauses of T can specify a completely different
3914 -- record layout from R's. Hence a same component can be placed in two very
3915 -- different positions in objects of type T and R. If R and T are tagged
3916 -- types, representation clauses for T can only specify the layout of non
3917 -- inherited components, thus components that are common in R and T have
3918 -- the same position in objects of type R or T.
3920 -- This has two implications. The first is that the entire tree for R's
3921 -- declaration needs to be copied for T in the untagged case, so that
3922 -- T can be viewd as a record type of its own with its own derivation
3923 -- clauses. The second implication is the way we handle discriminants.
3924 -- Specifically, in the untagged case we need a way to communicate to Gigi
3925 -- what are the real discriminants in the record, while for the semantics
3926 -- we need to consider those introduced by the user to rename the
3927 -- discriminants in the parent type. This is handled by introducing the
3928 -- notion of girder discriminants. See below for more.
3930 -- Fortunately the way regular components are inherited can be handled in
3931 -- the same way in tagged and untagged types.
3933 -- To complicate things a bit more the private view of a private extension
3934 -- cannot be handled in the same way as the full view (for one thing the
3935 -- semantic rules are somewhat different). We will explain what differs
3938 -- 2. DISCRIMINANTS UNDER INHERITANCE.
3940 -- The semantic rules governing the discriminants of derived types are
3943 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
3944 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
3946 -- If parent type has discriminants, then the discriminants that are
3947 -- declared in the derived type are [3.4 (11)]:
3949 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
3952 -- o Otherwise, each discriminant of the parent type (implicitly
3953 -- declared in the same order with the same specifications). In this
3954 -- case, the discriminants are said to be "inherited", or if unknown in
3955 -- the parent are also unknown in the derived type.
3957 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
3959 -- o The parent subtype shall be constrained;
3961 -- o If the parent type is not a tagged type, then each discriminant of
3962 -- the derived type shall be used in the constraint defining a parent
3963 -- subtype [Implementation note: this ensures that the new discriminant
3964 -- can share storage with an existing discriminant.].
3966 -- For the derived type each discriminant of the parent type is either
3967 -- inherited, constrained to equal some new discriminant of the derived
3968 -- type, or constrained to the value of an expression.
3970 -- When inherited or constrained to equal some new discriminant, the
3971 -- parent discriminant and the discriminant of the derived type are said
3974 -- If a discriminant of the parent type is constrained to a specific value
3975 -- in the derived type definition, then the discriminant is said to be
3976 -- "specified" by that derived type definition.
3978 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
3980 -- We have spoken about girder discriminants in the point 1 (introduction)
3981 -- above. There are two sort of girder discriminants: implicit and
3982 -- explicit. As long as the derived type inherits the same discriminants as
3983 -- the root record type, girder discriminants are the same as regular
3984 -- discriminants, and are said to be implicit. However, if any discriminant
3985 -- in the root type was renamed in the derived type, then the derived
3986 -- type will contain explicit girder discriminants. Explicit girder
3987 -- discriminants are discriminants in addition to the semantically visible
3988 -- discriminants defined for the derived type. Girder discriminants are
3989 -- used by Gigi to figure out what are the physical discriminants in
3990 -- objects of the derived type (see precise definition in einfo.ads).
3991 -- As an example, consider the following:
3993 -- type R (D1, D2, D3 : Int) is record ... end record;
3994 -- type T1 is new R;
3995 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
3996 -- type T3 is new T2;
3997 -- type T4 (Y : Int) is new T3 (Y, 99);
3999 -- The following table summarizes the discriminants and girder
4000 -- discriminants in R and T1 through T4.
4002 -- Type Discrim Girder Discrim Comment
4003 -- R (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in R
4004 -- T1 (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in T1
4005 -- T2 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T2
4006 -- T3 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T3
4007 -- T4 (Y) (D1, D2, D3) Gider discrims are EXPLICIT in T4
4009 -- Field Corresponding_Discriminant (abbreviated CD below) allows to find
4010 -- the corresponding discriminant in the parent type, while
4011 -- Original_Record_Component (abbreviated ORC below), the actual physical
4012 -- component that is renamed. Finally the field Is_Completely_Hidden
4013 -- (abbreaviated ICH below) is set for all explicit girder discriminants
4014 -- (see einfo.ads for more info). For the above example this gives:
4016 -- Discrim CD ORC ICH
4017 -- ^^^^^^^ ^^ ^^^ ^^^
4018 -- D1 in R empty itself no
4019 -- D2 in R empty itself no
4020 -- D3 in R empty itself no
4022 -- D1 in T1 D1 in R itself no
4023 -- D2 in T1 D2 in R itself no
4024 -- D3 in T1 D3 in R itself no
4026 -- X1 in T2 D3 in T1 D3 in T2 no
4027 -- X2 in T2 D1 in T1 D1 in T2 no
4028 -- D1 in T2 empty itself yes
4029 -- D2 in T2 empty itself yes
4030 -- D3 in T2 empty itself yes
4032 -- X1 in T3 X1 in T2 D3 in T3 no
4033 -- X2 in T3 X2 in T2 D1 in T3 no
4034 -- D1 in T3 empty itself yes
4035 -- D2 in T3 empty itself yes
4036 -- D3 in T3 empty itself yes
4038 -- Y in T4 X1 in T3 D3 in T3 no
4039 -- D1 in T3 empty itself yes
4040 -- D2 in T3 empty itself yes
4041 -- D3 in T3 empty itself yes
4043 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
4045 -- Type derivation for tagged types is fairly straightforward. if no
4046 -- discriminants are specified by the derived type, these are inherited
4047 -- from the parent. No explicit girder discriminants are ever necessary.
4048 -- The only manipulation that is done to the tree is that of adding a
4049 -- _parent field with parent type and constrained to the same constraint
4050 -- specified for the parent in the derived type definition. For instance:
4052 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
4053 -- type T1 is new R with null record;
4054 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
4056 -- are changed into :
4058 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
4059 -- _parent : R (D1, D2, D3);
4062 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
4063 -- _parent : T1 (X2, 88, X1);
4066 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4067 -- ORC and ICH fields are:
4069 -- Discrim CD ORC ICH
4070 -- ^^^^^^^ ^^ ^^^ ^^^
4071 -- D1 in R empty itself no
4072 -- D2 in R empty itself no
4073 -- D3 in R empty itself no
4075 -- D1 in T1 D1 in R D1 in R no
4076 -- D2 in T1 D2 in R D2 in R no
4077 -- D3 in T1 D3 in R D3 in R no
4079 -- X1 in T2 D3 in T1 D3 in R no
4080 -- X2 in T2 D1 in T1 D1 in R no
4082 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
4084 -- Regardless of whether we dealing with a tagged or untagged type
4085 -- we will transform all derived type declarations of the form
4087 -- type T is new R (...) [with ...];
4089 -- subtype S is R (...);
4090 -- type T is new S [with ...];
4092 -- type BT is new R [with ...];
4093 -- subtype T is BT (...);
4095 -- That is, the base derived type is constrained only if it has no
4096 -- discriminants. The reason for doing this is that GNAT's semantic model
4097 -- assumes that a base type with discriminants is unconstrained.
4099 -- Note that, strictly speaking, the above transformation is not always
4100 -- correct. Consider for instance the following exercpt from ACVC b34011a:
4102 -- procedure B34011A is
4103 -- type REC (D : integer := 0) is record
4108 -- type T6 is new Rec;
4109 -- function F return T6;
4114 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4117 -- The definition of Q6.U is illegal. However transforming Q6.U into
4119 -- type BaseU is new T6;
4120 -- subtype U is BaseU (Q6.F.I)
4122 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4123 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4124 -- the transformation described above.
4126 -- There is another instance where the above transformation is incorrect.
4130 -- type Base (D : Integer) is tagged null record;
4131 -- procedure P (X : Base);
4133 -- type Der is new Base (2) with null record;
4134 -- procedure P (X : Der);
4137 -- Then the above transformation turns this into
4139 -- type Der_Base is new Base with null record;
4140 -- -- procedure P (X : Base) is implicitly inherited here
4141 -- -- as procedure P (X : Der_Base).
4143 -- subtype Der is Der_Base (2);
4144 -- procedure P (X : Der);
4145 -- -- The overriding of P (X : Der_Base) is illegal since we
4146 -- -- have a parameter conformance problem.
4148 -- To get around this problem, after having semantically processed Der_Base
4149 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4150 -- Discriminant_Constraint from Der so that when parameter conformance is
4151 -- checked when P is overridden, no sematic errors are flagged.
4153 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
4155 -- Regardless of the fact that we dealing with a tagged or untagged type
4156 -- we will transform all derived type declarations of the form
4158 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4159 -- type T is new R [with ...];
4161 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4163 -- The reason for such transformation is that it allows us to implement a
4164 -- very clean form of component inheritance as explained below.
4166 -- Note that this transformation is not achieved by direct tree rewriting
4167 -- and manipulation, but rather by redoing the semantic actions that the
4168 -- above transformation will entail. This is done directly in routine
4169 -- Inherit_Components.
4171 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
4173 -- In both tagged and untagged derived types, regular non discriminant
4174 -- components are inherited in the derived type from the parent type. In
4175 -- the absence of discriminants component, inheritance is straightforward
4176 -- as components can simply be copied from the parent.
4177 -- If the parent has discriminants, inheriting components constrained with
4178 -- these discriminants requires caution. Consider the following example:
4180 -- type R (D1, D2 : Positive) is [tagged] record
4181 -- S : String (D1 .. D2);
4184 -- type T1 is new R [with null record];
4185 -- type T2 (X : positive) is new R (1, X) [with null record];
4187 -- As explained in 6. above, T1 is rewritten as
4189 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4191 -- which makes the treatment for T1 and T2 identical.
4193 -- What we want when inheriting S, is that references to D1 and D2 in R are
4194 -- replaced with references to their correct constraints, ie D1 and D2 in
4195 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4196 -- with either discriminant references in the derived type or expressions.
4197 -- This replacement is acheived as follows: before inheriting R's
4198 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4199 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4200 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4201 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4202 -- by String (1 .. X).
4204 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
4206 -- We explain here the rules governing private type extensions relevant to
4207 -- type derivation. These rules are explained on the following example:
4209 -- type D [(...)] is new A [(...)] with private; <-- partial view
4210 -- type D [(...)] is new P [(...)] with null record; <-- full view
4212 -- Type A is called the ancestor subtype of the private extension.
4213 -- Type P is the parent type of the full view of the private extension. It
4214 -- must be A or a type derived from A.
4216 -- The rules concerning the discriminants of private type extensions are
4219 -- o If a private extension inherits known discriminants from the ancestor
4220 -- subtype, then the full view shall also inherit its discriminants from
4221 -- the ancestor subtype and the parent subtype of the full view shall be
4222 -- constrained if and only if the ancestor subtype is constrained.
4224 -- o If a partial view has unknown discriminants, then the full view may
4225 -- define a definite or an indefinite subtype, with or without
4228 -- o If a partial view has neither known nor unknown discriminants, then
4229 -- the full view shall define a definite subtype.
4231 -- o If the ancestor subtype of a private extension has constrained
4232 -- discrimiants, then the parent subtype of the full view shall impose a
4233 -- statically matching constraint on those discriminants.
4235 -- This means that only the following forms of private extensions are
4238 -- type D is new A with private; <-- partial view
4239 -- type D is new P with null record; <-- full view
4241 -- If A has no discriminants than P has no discriminants, otherwise P must
4242 -- inherit A's discriminants.
4244 -- type D is new A (...) with private; <-- partial view
4245 -- type D is new P (:::) with null record; <-- full view
4247 -- P must inherit A's discriminants and (...) and (:::) must statically
4250 -- subtype A is R (...);
4251 -- type D is new A with private; <-- partial view
4252 -- type D is new P with null record; <-- full view
4254 -- P must have inherited R's discriminants and must be derived from A or
4255 -- any of its subtypes.
4257 -- type D (..) is new A with private; <-- partial view
4258 -- type D (..) is new P [(:::)] with null record; <-- full view
4260 -- No specific constraints on P's discriminants or constraint (:::).
4261 -- Note that A can be unconstrained, but the parent subtype P must either
4262 -- be constrained or (:::) must be present.
4264 -- type D (..) is new A [(...)] with private; <-- partial view
4265 -- type D (..) is new P [(:::)] with null record; <-- full view
4267 -- P's constraints on A's discriminants must statically match those
4268 -- imposed by (...).
4270 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
4272 -- The full view of a private extension is handled exactly as described
4273 -- above. The model chose for the private view of a private extension
4274 -- is the same for what concerns discriminants (ie they receive the same
4275 -- treatment as in the tagged case). However, the private view of the
4276 -- private extension always inherits the components of the parent base,
4277 -- without replacing any discriminant reference. Strictly speacking this
4278 -- is incorrect. However, Gigi never uses this view to generate code so
4279 -- this is a purely semantic issue. In theory, a set of transformations
4280 -- similar to those given in 5. and 6. above could be applied to private
4281 -- views of private extensions to have the same model of component
4282 -- inheritance as for non private extensions. However, this is not done
4283 -- because it would further complicate private type processing.
4284 -- Semantically speaking, this leaves us in an uncomfortable
4285 -- situation. As an example consider:
4288 -- type R (D : integer) is tagged record
4289 -- S : String (1 .. D);
4291 -- procedure P (X : R);
4292 -- type T is new R (1) with private;
4294 -- type T is new R (1) with null record;
4297 -- This is transformed into:
4300 -- type R (D : integer) is tagged record
4301 -- S : String (1 .. D);
4303 -- procedure P (X : R);
4304 -- type T is new R (1) with private;
4306 -- type BaseT is new R with null record;
4307 -- subtype T is BaseT (1);
4310 -- (strictly speaking the above is incorrect Ada).
4312 -- From the semantic standpoint the private view of private extension T
4313 -- should be flagged as constrained since one can clearly have
4317 -- in a unit withing Pack. However, when deriving subprograms for the
4318 -- private view of private extension T, T must be seen as unconstrained
4319 -- since T has discriminants (this is a constraint of the current
4320 -- subprogram derivation model). Thus, when processing the private view of
4321 -- a private extension such as T, we first mark T as unconstrained, we
4322 -- process it, we perform program derivation and just before returning from
4323 -- Build_Derived_Record_Type we mark T as constrained.
4324 -- ??? Are there are other unconfortable cases that we will have to
4327 -- 10. RECORD_TYPE_WITH_PRIVATE complications.
4329 -- Types that are derived from a visible record type and have a private
4330 -- extension present other peculiarities. They behave mostly like private
4331 -- types, but if they have primitive operations defined, these will not
4332 -- have the proper signatures for further inheritance, because other
4333 -- primitive operations will use the implicit base that we define for
4334 -- private derivations below. This affect subprogram inheritance (see
4335 -- Derive_Subprograms for details). We also derive the implicit base from
4336 -- the base type of the full view, so that the implicit base is a record
4337 -- type and not another private type, This avoids infinite loops.
4339 procedure Build_Derived_Record_Type
4341 Parent_Type : Entity_Id;
4342 Derived_Type : Entity_Id;
4343 Derive_Subps : Boolean := True)
4345 Loc : constant Source_Ptr := Sloc (N);
4346 Parent_Base : Entity_Id;
4351 Discrim : Entity_Id;
4352 Last_Discrim : Entity_Id;
4354 Discs : Elist_Id := New_Elmt_List;
4355 -- An empty Discs list means that there were no constraints in the
4356 -- subtype indication or that there was an error processing it.
4358 Assoc_List : Elist_Id;
4359 New_Discrs : Elist_Id;
4361 New_Base : Entity_Id;
4363 New_Indic : Node_Id;
4365 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4366 Discriminant_Specs : constant Boolean
4367 := Present (Discriminant_Specifications (N));
4368 Private_Extension : constant Boolean
4369 := (Nkind (N) = N_Private_Extension_Declaration);
4371 Constraint_Present : Boolean;
4372 Inherit_Discrims : Boolean := False;
4374 Save_Etype : Entity_Id;
4375 Save_Discr_Constr : Elist_Id;
4376 Save_Next_Entity : Entity_Id;
4379 if Ekind (Parent_Type) = E_Record_Type_With_Private
4380 and then Present (Full_View (Parent_Type))
4381 and then Has_Discriminants (Parent_Type)
4383 Parent_Base := Base_Type (Full_View (Parent_Type));
4385 Parent_Base := Base_Type (Parent_Type);
4388 -- Before we start the previously documented transformations, here is
4389 -- a little fix for size and alignment of tagged types. Normally when
4390 -- we derive type D from type P, we copy the size and alignment of P
4391 -- as the default for D, and in the absence of explicit representation
4392 -- clauses for D, the size and alignment are indeed the same as the
4395 -- But this is wrong for tagged types, since fields may be added,
4396 -- and the default size may need to be larger, and the default
4397 -- alignment may need to be larger.
4399 -- We therefore reset the size and alignment fields in the tagged
4400 -- case. Note that the size and alignment will in any case be at
4401 -- least as large as the parent type (since the derived type has
4402 -- a copy of the parent type in the _parent field)
4405 Init_Size_Align (Derived_Type);
4408 -- STEP 0a: figure out what kind of derived type declaration we have.
4410 if Private_Extension then
4412 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4415 Type_Def := Type_Definition (N);
4417 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4418 -- Parent_Base can be a private type or private extension. However,
4419 -- for tagged types with an extension the newly added fields are
4420 -- visible and hence the Derived_Type is always an E_Record_Type.
4421 -- (except that the parent may have its own private fields).
4422 -- For untagged types we preserve the Ekind of the Parent_Base.
4424 if Present (Record_Extension_Part (Type_Def)) then
4425 Set_Ekind (Derived_Type, E_Record_Type);
4427 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4431 -- Indic can either be an N_Identifier if the subtype indication
4432 -- contains no constraint or an N_Subtype_Indication if the subtype
4433 -- indication has a constraint.
4435 Indic := Subtype_Indication (Type_Def);
4436 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
4438 if Constraint_Present then
4439 if not Has_Discriminants (Parent_Base) then
4441 ("invalid constraint: type has no discriminant",
4442 Constraint (Indic));
4444 Constraint_Present := False;
4445 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4447 elsif Is_Constrained (Parent_Type) then
4449 ("invalid constraint: parent type is already constrained",
4450 Constraint (Indic));
4452 Constraint_Present := False;
4453 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4457 -- STEP 0b: If needed, apply transformation given in point 5. above.
4459 if not Private_Extension
4460 and then Has_Discriminants (Parent_Type)
4461 and then not Discriminant_Specs
4462 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
4464 -- First, we must analyze the constraint (see comment in point 5.).
4466 if Constraint_Present then
4467 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
4469 if Has_Discriminants (Derived_Type)
4470 and then Has_Private_Declaration (Derived_Type)
4471 and then Present (Discriminant_Constraint (Derived_Type))
4473 -- Verify that constraints of the full view conform to those
4474 -- given in partial view.
4480 C1 := First_Elmt (New_Discrs);
4481 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
4483 while Present (C1) and then Present (C2) loop
4485 Fully_Conformant_Expressions (Node (C1), Node (C2))
4488 "constraint not conformant to previous declaration",
4498 -- Insert and analyze the declaration for the unconstrained base type
4500 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
4503 Make_Full_Type_Declaration (Loc,
4504 Defining_Identifier => New_Base,
4506 Make_Derived_Type_Definition (Loc,
4507 Abstract_Present => Abstract_Present (Type_Def),
4508 Subtype_Indication =>
4509 New_Occurrence_Of (Parent_Base, Loc),
4510 Record_Extension_Part =>
4511 Relocate_Node (Record_Extension_Part (Type_Def))));
4513 Set_Parent (New_Decl, Parent (N));
4514 Mark_Rewrite_Insertion (New_Decl);
4515 Insert_Before (N, New_Decl);
4517 -- Note that this call passes False for the Derive_Subps
4518 -- parameter because subprogram derivation is deferred until
4519 -- after creating the subtype (see below).
4522 (New_Decl, Parent_Base, New_Base,
4523 Is_Completion => True, Derive_Subps => False);
4525 -- ??? This needs re-examination to determine whether the
4526 -- above call can simply be replaced by a call to Analyze.
4528 Set_Analyzed (New_Decl);
4530 -- Insert and analyze the declaration for the constrained subtype
4532 if Constraint_Present then
4534 Make_Subtype_Indication (Loc,
4535 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4536 Constraint => Relocate_Node (Constraint (Indic)));
4541 Constr_List : List_Id := New_List;
4545 C := First_Elmt (Discriminant_Constraint (Parent_Type));
4546 while Present (C) loop
4549 -- It is safe here to call New_Copy_Tree since
4550 -- Force_Evaluation was called on each constraint in
4551 -- Build_Discriminant_Constraints.
4553 Append (New_Copy_Tree (Expr), To => Constr_List);
4559 Make_Subtype_Indication (Loc,
4560 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4562 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
4567 Make_Subtype_Declaration (Loc,
4568 Defining_Identifier => Derived_Type,
4569 Subtype_Indication => New_Indic));
4573 -- Derivation of subprograms must be delayed until the
4574 -- full subtype has been established to ensure proper
4575 -- overriding of subprograms inherited by full types.
4576 -- If the derivations occurred as part of the call to
4577 -- Build_Derived_Type above, then the check for type
4578 -- conformance would fail because earlier primitive
4579 -- subprograms could still refer to the full type prior
4580 -- the change to the new subtype and hence wouldn't
4581 -- match the new base type created here.
4583 Derive_Subprograms (Parent_Type, Derived_Type);
4585 -- For tagged types the Discriminant_Constraint of the new base itype
4586 -- is inherited from the first subtype so that no subtype conformance
4587 -- problem arise when the first subtype overrides primitive
4588 -- operations inherited by the implicit base type.
4591 Set_Discriminant_Constraint
4592 (New_Base, Discriminant_Constraint (Derived_Type));
4598 -- If we get here Derived_Type will have no discriminants or it will be
4599 -- a discriminated unconstrained base type.
4601 -- STEP 1a: perform preliminary actions/checks for derived tagged types
4604 -- The parent type is frozen for non-private extensions (RM 13.14(7))
4606 if not Private_Extension then
4607 Freeze_Before (N, Parent_Type);
4610 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
4611 and then not Is_Generic_Type (Derived_Type)
4613 if Is_Controlled (Parent_Type) then
4615 ("controlled type must be declared at the library level",
4619 ("type extension at deeper accessibility level than parent",
4625 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
4629 and then GB /= Enclosing_Generic_Body (Parent_Base)
4632 ("parent type must not be outside generic body",
4639 -- STEP 1b : preliminary cleanup of the full view of private types
4641 -- If the type is already marked as having discriminants, then it's the
4642 -- completion of a private type or private extension and we need to
4643 -- retain the discriminants from the partial view if the current
4644 -- declaration has Discriminant_Specifications so that we can verify
4645 -- conformance. However, we must remove any existing components that
4646 -- were inherited from the parent (and attached in Copy_Private_To_Full)
4647 -- because the full type inherits all appropriate components anyway, and
4648 -- we don't want the partial view's components interfering.
4650 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
4651 Discrim := First_Discriminant (Derived_Type);
4653 Last_Discrim := Discrim;
4654 Next_Discriminant (Discrim);
4655 exit when No (Discrim);
4658 Set_Last_Entity (Derived_Type, Last_Discrim);
4660 -- In all other cases wipe out the list of inherited components (even
4661 -- inherited discriminants), it will be properly rebuilt here.
4664 Set_First_Entity (Derived_Type, Empty);
4665 Set_Last_Entity (Derived_Type, Empty);
4668 -- STEP 1c: Initialize some flags for the Derived_Type
4670 -- The following flags must be initialized here so that
4671 -- Process_Discriminants can check that discriminants of tagged types
4672 -- do not have a default initial value and that access discriminants
4673 -- are only specified for limited records. For completeness, these
4674 -- flags are also initialized along with all the other flags below.
4676 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4677 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
4679 -- STEP 2a: process discriminants of derived type if any.
4681 New_Scope (Derived_Type);
4683 if Discriminant_Specs then
4684 Set_Has_Unknown_Discriminants (Derived_Type, False);
4686 -- The following call initializes fields Has_Discriminants and
4687 -- Discriminant_Constraint, unless we are processing the completion
4688 -- of a private type declaration.
4690 Check_Or_Process_Discriminants (N, Derived_Type);
4692 -- For non-tagged types the constraint on the Parent_Type must be
4693 -- present and is used to rename the discriminants.
4695 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
4696 Error_Msg_N ("untagged parent must have discriminants", Indic);
4698 elsif not Is_Tagged and then not Constraint_Present then
4700 ("discriminant constraint needed for derived untagged records",
4703 -- Otherwise the parent subtype must be constrained unless we have a
4704 -- private extension.
4706 elsif not Constraint_Present
4707 and then not Private_Extension
4708 and then not Is_Constrained (Parent_Type)
4711 ("unconstrained type not allowed in this context", Indic);
4713 elsif Constraint_Present then
4714 -- The following call sets the field Corresponding_Discriminant
4715 -- for the discriminants in the Derived_Type.
4717 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
4719 -- For untagged types all new discriminants must rename
4720 -- discriminants in the parent. For private extensions new
4721 -- discriminants cannot rename old ones (implied by [7.3(13)]).
4723 Discrim := First_Discriminant (Derived_Type);
4725 while Present (Discrim) loop
4727 and then not Present (Corresponding_Discriminant (Discrim))
4730 ("new discriminants must constrain old ones", Discrim);
4732 elsif Private_Extension
4733 and then Present (Corresponding_Discriminant (Discrim))
4736 ("Only static constraints allowed for parent"
4737 & " discriminants in the partial view", Indic);
4742 -- If a new discriminant is used in the constraint,
4743 -- then its subtype must be statically compatible
4744 -- with the parent discriminant's subtype (3.7(15)).
4746 if Present (Corresponding_Discriminant (Discrim))
4748 not Subtypes_Statically_Compatible
4750 Etype (Corresponding_Discriminant (Discrim)))
4753 ("subtype must be compatible with parent discriminant",
4757 Next_Discriminant (Discrim);
4761 -- STEP 2b: No new discriminants, inherit discriminants if any
4764 if Private_Extension then
4765 Set_Has_Unknown_Discriminants
4766 (Derived_Type, Has_Unknown_Discriminants (Parent_Type)
4767 or else Unknown_Discriminants_Present (N));
4769 Set_Has_Unknown_Discriminants
4770 (Derived_Type, Has_Unknown_Discriminants (Parent_Type));
4773 if not Has_Unknown_Discriminants (Derived_Type)
4774 and then Has_Discriminants (Parent_Type)
4776 Inherit_Discrims := True;
4777 Set_Has_Discriminants
4778 (Derived_Type, True);
4779 Set_Discriminant_Constraint
4780 (Derived_Type, Discriminant_Constraint (Parent_Base));
4783 -- The following test is true for private types (remember
4784 -- transformation 5. is not applied to those) and in an error
4787 if Constraint_Present then
4788 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
4791 -- For now mark a new derived type as cosntrained only if it has no
4792 -- discriminants. At the end of Build_Derived_Record_Type we properly
4793 -- set this flag in the case of private extensions. See comments in
4794 -- point 9. just before body of Build_Derived_Record_Type.
4798 not (Inherit_Discrims
4799 or else Has_Unknown_Discriminants (Derived_Type)));
4802 -- STEP 3: initialize fields of derived type.
4804 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4805 Set_Girder_Constraint (Derived_Type, No_Elist);
4807 -- Fields inherited from the Parent_Type
4810 (Derived_Type, Einfo.Discard_Names (Parent_Type));
4811 Set_Has_Specified_Layout
4812 (Derived_Type, Has_Specified_Layout (Parent_Type));
4813 Set_Is_Limited_Composite
4814 (Derived_Type, Is_Limited_Composite (Parent_Type));
4815 Set_Is_Limited_Record
4816 (Derived_Type, Is_Limited_Record (Parent_Type));
4817 Set_Is_Private_Composite
4818 (Derived_Type, Is_Private_Composite (Parent_Type));
4820 -- Fields inherited from the Parent_Base
4822 Set_Has_Controlled_Component
4823 (Derived_Type, Has_Controlled_Component (Parent_Base));
4824 Set_Has_Non_Standard_Rep
4825 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4826 Set_Has_Primitive_Operations
4827 (Derived_Type, Has_Primitive_Operations (Parent_Base));
4829 -- Direct controlled types do not inherit the Finalize_Storage_Only
4832 if not Is_Controlled (Parent_Type) then
4833 Set_Finalize_Storage_Only (Derived_Type,
4834 Finalize_Storage_Only (Parent_Type));
4837 -- Set fields for private derived types.
4839 if Is_Private_Type (Derived_Type) then
4840 Set_Depends_On_Private (Derived_Type, True);
4841 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4843 -- Inherit fields from non private record types. If this is the
4844 -- completion of a derivation from a private type, the parent itself
4845 -- is private, and the attributes come from its full view, which must
4849 if Is_Private_Type (Parent_Base)
4850 and then not Is_Record_Type (Parent_Base)
4852 Set_Component_Alignment
4853 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
4855 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
4857 Set_Component_Alignment
4858 (Derived_Type, Component_Alignment (Parent_Base));
4861 (Derived_Type, C_Pass_By_Copy (Parent_Base));
4865 -- Set fields for tagged types.
4868 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
4870 -- All tagged types defined in Ada.Finalization are controlled
4872 if Chars (Scope (Derived_Type)) = Name_Finalization
4873 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
4874 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
4876 Set_Is_Controlled (Derived_Type);
4878 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
4881 Make_Class_Wide_Type (Derived_Type);
4882 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
4884 if Has_Discriminants (Derived_Type)
4885 and then Constraint_Present
4887 Set_Girder_Constraint
4888 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4892 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
4893 Set_Has_Non_Standard_Rep
4894 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4897 -- STEP 4: Inherit components from the parent base and constrain them.
4898 -- Apply the second transformation described in point 6. above.
4900 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
4901 or else not Has_Discriminants (Parent_Type)
4902 or else not Is_Constrained (Parent_Type)
4906 Constrs := Discriminant_Constraint (Parent_Type);
4909 Assoc_List := Inherit_Components (N,
4910 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
4912 -- STEP 5a: Copy the parent record declaration for untagged types
4914 if not Is_Tagged then
4916 -- Discriminant_Constraint (Derived_Type) has been properly
4917 -- constructed. Save it and temporarily set it to Empty because we do
4918 -- not want the call to New_Copy_Tree below to mess this list.
4920 if Has_Discriminants (Derived_Type) then
4921 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
4922 Set_Discriminant_Constraint (Derived_Type, No_Elist);
4924 Save_Discr_Constr := No_Elist;
4927 -- Save the Etype field of Derived_Type. It is correctly set now, but
4928 -- the call to New_Copy tree may remap it to point to itself, which
4929 -- is not what we want. Ditto for the Next_Entity field.
4931 Save_Etype := Etype (Derived_Type);
4932 Save_Next_Entity := Next_Entity (Derived_Type);
4934 -- Assoc_List maps all girder discriminants in the Parent_Base to
4935 -- girder discriminants in the Derived_Type. It is fundamental that
4936 -- no types or itypes with discriminants other than the girder
4937 -- discriminants appear in the entities declared inside
4938 -- Derived_Type. Gigi won't like it.
4942 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
4944 -- Restore the fields saved prior to the New_Copy_Tree call
4945 -- and compute the girder constraint.
4947 Set_Etype (Derived_Type, Save_Etype);
4948 Set_Next_Entity (Derived_Type, Save_Next_Entity);
4950 if Has_Discriminants (Derived_Type) then
4951 Set_Discriminant_Constraint
4952 (Derived_Type, Save_Discr_Constr);
4953 Set_Girder_Constraint
4954 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4957 -- Insert the new derived type declaration
4959 Rewrite (N, New_Decl);
4961 -- STEP 5b: Complete the processing for record extensions in generics
4963 -- There is no completion for record extensions declared in the
4964 -- parameter part of a generic, so we need to complete processing for
4965 -- these generic record extensions here. The call to
4966 -- Record_Type_Definition will change the Ekind of the components
4967 -- from E_Void to E_Component.
4969 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
4970 Record_Type_Definition (Empty, Derived_Type);
4972 -- STEP 5c: Process the record extension for non private tagged types.
4974 elsif not Private_Extension then
4975 -- Add the _parent field in the derived type.
4977 Expand_Derived_Record (Derived_Type, Type_Def);
4979 -- Analyze the record extension
4981 Record_Type_Definition
4982 (Record_Extension_Part (Type_Def), Derived_Type);
4987 if Etype (Derived_Type) = Any_Type then
4991 -- Set delayed freeze and then derive subprograms, we need to do
4992 -- this in this order so that derived subprograms inherit the
4993 -- derived freeze if necessary.
4995 Set_Has_Delayed_Freeze (Derived_Type);
4996 if Derive_Subps then
4997 Derive_Subprograms (Parent_Type, Derived_Type);
5000 -- If we have a private extension which defines a constrained derived
5001 -- type mark as constrained here after we have derived subprograms. See
5002 -- comment on point 9. just above the body of Build_Derived_Record_Type.
5004 if Private_Extension and then Inherit_Discrims then
5005 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
5006 Set_Is_Constrained (Derived_Type, True);
5007 Set_Discriminant_Constraint (Derived_Type, Discs);
5009 elsif Is_Constrained (Parent_Type) then
5011 (Derived_Type, True);
5012 Set_Discriminant_Constraint
5013 (Derived_Type, Discriminant_Constraint (Parent_Type));
5017 end Build_Derived_Record_Type;
5019 ------------------------
5020 -- Build_Derived_Type --
5021 ------------------------
5023 procedure Build_Derived_Type
5025 Parent_Type : Entity_Id;
5026 Derived_Type : Entity_Id;
5027 Is_Completion : Boolean;
5028 Derive_Subps : Boolean := True)
5030 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5033 -- Set common attributes
5035 Set_Scope (Derived_Type, Current_Scope);
5037 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5038 Set_Etype (Derived_Type, Parent_Base);
5039 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
5041 Set_Size_Info (Derived_Type, Parent_Type);
5042 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5043 Set_Convention (Derived_Type, Convention (Parent_Type));
5044 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
5045 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
5047 case Ekind (Parent_Type) is
5048 when Numeric_Kind =>
5049 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
5052 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
5056 | Class_Wide_Kind =>
5057 Build_Derived_Record_Type
5058 (N, Parent_Type, Derived_Type, Derive_Subps);
5061 when Enumeration_Kind =>
5062 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5065 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5067 when Incomplete_Or_Private_Kind =>
5068 Build_Derived_Private_Type
5069 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5071 -- For discriminated types, the derivation includes deriving
5072 -- primitive operations. For others it is done below.
5074 if Is_Tagged_Type (Parent_Type)
5075 or else Has_Discriminants (Parent_Type)
5076 or else (Present (Full_View (Parent_Type))
5077 and then Has_Discriminants (Full_View (Parent_Type)))
5082 when Concurrent_Kind =>
5083 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5086 raise Program_Error;
5089 if Etype (Derived_Type) = Any_Type then
5093 -- Set delayed freeze and then derive subprograms, we need to do
5094 -- this in this order so that derived subprograms inherit the
5095 -- derived freeze if necessary.
5097 Set_Has_Delayed_Freeze (Derived_Type);
5098 if Derive_Subps then
5099 Derive_Subprograms (Parent_Type, Derived_Type);
5102 Set_Has_Primitive_Operations
5103 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5104 end Build_Derived_Type;
5106 -----------------------
5107 -- Build_Discriminal --
5108 -----------------------
5110 procedure Build_Discriminal (Discrim : Entity_Id) is
5111 D_Minal : Entity_Id;
5112 CR_Disc : Entity_Id;
5115 -- A discriminal has the same names as the discriminant.
5117 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5119 Set_Ekind (D_Minal, E_In_Parameter);
5120 Set_Mechanism (D_Minal, Default_Mechanism);
5121 Set_Etype (D_Minal, Etype (Discrim));
5123 Set_Discriminal (Discrim, D_Minal);
5124 Set_Discriminal_Link (D_Minal, Discrim);
5126 -- For task types, build at once the discriminants of the corresponding
5127 -- record, which are needed if discriminants are used in entry defaults
5128 -- and in family bounds.
5130 if Is_Concurrent_Type (Current_Scope)
5131 or else Is_Limited_Type (Current_Scope)
5133 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5135 Set_Ekind (CR_Disc, E_In_Parameter);
5136 Set_Mechanism (CR_Disc, Default_Mechanism);
5137 Set_Etype (CR_Disc, Etype (Discrim));
5138 Set_CR_Discriminant (Discrim, CR_Disc);
5140 end Build_Discriminal;
5142 ------------------------------------
5143 -- Build_Discriminant_Constraints --
5144 ------------------------------------
5146 function Build_Discriminant_Constraints
5149 Derived_Def : Boolean := False)
5152 C : constant Node_Id := Constraint (Def);
5153 Nb_Discr : constant Nat := Number_Discriminants (T);
5154 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5155 -- Saves the expression corresponding to a given discriminant in T.
5157 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5158 -- Return the Position number within array Discr_Expr of a discriminant
5159 -- D within the discriminant list of the discriminated type T.
5165 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5169 Disc := First_Discriminant (T);
5170 for J in Discr_Expr'Range loop
5175 Next_Discriminant (Disc);
5178 -- Note: Since this function is called on discriminants that are
5179 -- known to belong to the discriminated type, falling through the
5180 -- loop with no match signals an internal compiler error.
5182 raise Program_Error;
5185 -- Variables local to Build_Discriminant_Constraints
5189 Elist : Elist_Id := New_Elmt_List;
5197 Discrim_Present : Boolean := False;
5199 -- Start of processing for Build_Discriminant_Constraints
5202 -- The following loop will process positional associations only.
5203 -- For a positional association, the (single) discriminant is
5204 -- implicitly specified by position, in textual order (RM 3.7.2).
5206 Discr := First_Discriminant (T);
5207 Constr := First (Constraints (C));
5209 for D in Discr_Expr'Range loop
5210 exit when Nkind (Constr) = N_Discriminant_Association;
5213 Error_Msg_N ("too few discriminants given in constraint", C);
5214 return New_Elmt_List;
5216 elsif Nkind (Constr) = N_Range
5217 or else (Nkind (Constr) = N_Attribute_Reference
5219 Attribute_Name (Constr) = Name_Range)
5222 ("a range is not a valid discriminant constraint", Constr);
5223 Discr_Expr (D) := Error;
5226 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5227 Discr_Expr (D) := Constr;
5230 Next_Discriminant (Discr);
5234 if No (Discr) and then Present (Constr) then
5235 Error_Msg_N ("too many discriminants given in constraint", Constr);
5236 return New_Elmt_List;
5239 -- Named associations can be given in any order, but if both positional
5240 -- and named associations are used in the same discriminant constraint,
5241 -- then positional associations must occur first, at their normal
5242 -- position. Hence once a named association is used, the rest of the
5243 -- discriminant constraint must use only named associations.
5245 while Present (Constr) loop
5247 -- Positional association forbidden after a named association.
5249 if Nkind (Constr) /= N_Discriminant_Association then
5250 Error_Msg_N ("positional association follows named one", Constr);
5251 return New_Elmt_List;
5253 -- Otherwise it is a named association
5256 -- E records the type of the discriminants in the named
5257 -- association. All the discriminants specified in the same name
5258 -- association must have the same type.
5262 -- Search the list of discriminants in T to see if the simple name
5263 -- given in the constraint matches any of them.
5265 Id := First (Selector_Names (Constr));
5266 while Present (Id) loop
5269 -- If Original_Discriminant is present, we are processing a
5270 -- generic instantiation and this is an instance node. We need
5271 -- to find the name of the corresponding discriminant in the
5272 -- actual record type T and not the name of the discriminant in
5273 -- the generic formal. Example:
5276 -- type G (D : int) is private;
5278 -- subtype W is G (D => 1);
5280 -- type Rec (X : int) is record ... end record;
5281 -- package Q is new P (G => Rec);
5283 -- At the point of the instantiation, formal type G is Rec
5284 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5285 -- which really looks like "subtype W is Rec (D => 1);" at
5286 -- the point of instantiation, we want to find the discriminant
5287 -- that corresponds to D in Rec, ie X.
5289 if Present (Original_Discriminant (Id)) then
5290 Discr := Find_Corresponding_Discriminant (Id, T);
5294 Discr := First_Discriminant (T);
5295 while Present (Discr) loop
5296 if Chars (Discr) = Chars (Id) then
5301 Next_Discriminant (Discr);
5305 Error_Msg_N ("& does not match any discriminant", Id);
5306 return New_Elmt_List;
5308 -- The following is only useful for the benefit of generic
5309 -- instances but it does not interfere with other
5310 -- processing for the non-generic case so we do it in all
5311 -- cases (for generics this statement is executed when
5312 -- processing the generic definition, see comment at the
5313 -- begining of this if statement).
5316 Set_Original_Discriminant (Id, Discr);
5320 Position := Pos_Of_Discr (T, Discr);
5322 if Present (Discr_Expr (Position)) then
5323 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5326 -- Each discriminant specified in the same named association
5327 -- must be associated with a separate copy of the
5328 -- corresponding expression.
5330 if Present (Next (Id)) then
5331 Expr := New_Copy_Tree (Expression (Constr));
5332 Set_Parent (Expr, Parent (Expression (Constr)));
5334 Expr := Expression (Constr);
5337 Discr_Expr (Position) := Expr;
5338 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
5341 -- A discriminant association with more than one discriminant
5342 -- name is only allowed if the named discriminants are all of
5343 -- the same type (RM 3.7.1(8)).
5346 E := Base_Type (Etype (Discr));
5348 elsif Base_Type (Etype (Discr)) /= E then
5350 ("all discriminants in an association " &
5351 "must have the same type", Id);
5361 -- A discriminant constraint must provide exactly one value for each
5362 -- discriminant of the type (RM 3.7.1(8)).
5364 for J in Discr_Expr'Range loop
5365 if No (Discr_Expr (J)) then
5366 Error_Msg_N ("too few discriminants given in constraint", C);
5367 return New_Elmt_List;
5371 -- Determine if there are discriminant expressions in the constraint.
5373 for J in Discr_Expr'Range loop
5374 if Denotes_Discriminant (Discr_Expr (J)) then
5375 Discrim_Present := True;
5379 -- Build an element list consisting of the expressions given in the
5380 -- discriminant constraint and apply the appropriate range
5381 -- checks. The list is constructed after resolving any named
5382 -- discriminant associations and therefore the expressions appear in
5383 -- the textual order of the discriminants.
5385 Discr := First_Discriminant (T);
5386 for J in Discr_Expr'Range loop
5387 if Discr_Expr (J) /= Error then
5389 Append_Elmt (Discr_Expr (J), Elist);
5391 -- If any of the discriminant constraints is given by a
5392 -- discriminant and we are in a derived type declaration we
5393 -- have a discriminant renaming. Establish link between new
5394 -- and old discriminant.
5396 if Denotes_Discriminant (Discr_Expr (J)) then
5398 Set_Corresponding_Discriminant
5399 (Entity (Discr_Expr (J)), Discr);
5402 -- Force the evaluation of non-discriminant expressions.
5403 -- If we have found a discriminant in the constraint 3.4(26)
5404 -- and 3.8(18) demand that no range checks are performed are
5405 -- after evaluation. In all other cases perform a range check.
5408 if not Discrim_Present then
5409 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
5412 Force_Evaluation (Discr_Expr (J));
5415 -- Check that the designated type of an access discriminant's
5416 -- expression is not a class-wide type unless the discriminant's
5417 -- designated type is also class-wide.
5419 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
5420 and then not Is_Class_Wide_Type
5421 (Designated_Type (Etype (Discr)))
5422 and then Etype (Discr_Expr (J)) /= Any_Type
5423 and then Is_Class_Wide_Type
5424 (Designated_Type (Etype (Discr_Expr (J))))
5426 Wrong_Type (Discr_Expr (J), Etype (Discr));
5430 Next_Discriminant (Discr);
5434 end Build_Discriminant_Constraints;
5436 ---------------------------------
5437 -- Build_Discriminated_Subtype --
5438 ---------------------------------
5440 procedure Build_Discriminated_Subtype
5444 Related_Nod : Node_Id;
5445 For_Access : Boolean := False)
5447 Has_Discrs : constant Boolean := Has_Discriminants (T);
5448 Constrained : constant Boolean
5449 := (Has_Discrs and then not Is_Empty_Elmt_List (Elist))
5450 or else Is_Constrained (T);
5453 if Ekind (T) = E_Record_Type then
5455 Set_Ekind (Def_Id, E_Private_Subtype);
5456 Set_Is_For_Access_Subtype (Def_Id, True);
5458 Set_Ekind (Def_Id, E_Record_Subtype);
5461 elsif Ekind (T) = E_Task_Type then
5462 Set_Ekind (Def_Id, E_Task_Subtype);
5464 elsif Ekind (T) = E_Protected_Type then
5465 Set_Ekind (Def_Id, E_Protected_Subtype);
5467 elsif Is_Private_Type (T) then
5468 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
5470 elsif Is_Class_Wide_Type (T) then
5471 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
5474 -- Incomplete type. Attach subtype to list of dependents, to be
5475 -- completed with full view of parent type.
5477 Set_Ekind (Def_Id, Ekind (T));
5478 Append_Elmt (Def_Id, Private_Dependents (T));
5481 Set_Etype (Def_Id, T);
5482 Init_Size_Align (Def_Id);
5483 Set_Has_Discriminants (Def_Id, Has_Discrs);
5484 Set_Is_Constrained (Def_Id, Constrained);
5486 Set_First_Entity (Def_Id, First_Entity (T));
5487 Set_Last_Entity (Def_Id, Last_Entity (T));
5488 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
5490 if Is_Tagged_Type (T) then
5491 Set_Is_Tagged_Type (Def_Id);
5492 Make_Class_Wide_Type (Def_Id);
5495 Set_Girder_Constraint (Def_Id, No_Elist);
5498 Set_Discriminant_Constraint (Def_Id, Elist);
5499 Set_Girder_Constraint_From_Discriminant_Constraint (Def_Id);
5502 if Is_Tagged_Type (T) then
5503 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
5504 Set_Is_Abstract (Def_Id, Is_Abstract (T));
5507 -- Subtypes introduced by component declarations do not need to be
5508 -- marked as delayed, and do not get freeze nodes, because the semantics
5509 -- verifies that the parents of the subtypes are frozen before the
5510 -- enclosing record is frozen.
5512 if not Is_Type (Scope (Def_Id)) then
5513 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
5515 if Is_Private_Type (T)
5516 and then Present (Full_View (T))
5518 Conditional_Delay (Def_Id, Full_View (T));
5520 Conditional_Delay (Def_Id, T);
5524 if Is_Record_Type (T) then
5525 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
5528 and then not Is_Empty_Elmt_List (Elist)
5529 and then not For_Access
5531 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
5532 elsif not For_Access then
5533 Set_Cloned_Subtype (Def_Id, T);
5537 end Build_Discriminated_Subtype;
5539 ------------------------
5540 -- Build_Scalar_Bound --
5541 ------------------------
5543 function Build_Scalar_Bound
5550 New_Bound : Entity_Id;
5553 -- Note: not clear why this is needed, how can the original bound
5554 -- be unanalyzed at this point? and if it is, what business do we
5555 -- have messing around with it? and why is the base type of the
5556 -- parent type the right type for the resolution. It probably is
5557 -- not! It is OK for the new bound we are creating, but not for
5558 -- the old one??? Still if it never happens, no problem!
5560 Analyze_And_Resolve (Bound, Base_Type (Par_T));
5562 if Nkind (Bound) = N_Integer_Literal
5563 or else Nkind (Bound) = N_Real_Literal
5565 New_Bound := New_Copy (Bound);
5566 Set_Etype (New_Bound, Der_T);
5567 Set_Analyzed (New_Bound);
5569 elsif Is_Entity_Name (Bound) then
5570 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
5572 -- The following is almost certainly wrong. What business do we have
5573 -- relocating a node (Bound) that is presumably still attached to
5574 -- the tree elsewhere???
5577 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
5580 Set_Etype (New_Bound, Der_T);
5582 end Build_Scalar_Bound;
5584 --------------------------------
5585 -- Build_Underlying_Full_View --
5586 --------------------------------
5588 procedure Build_Underlying_Full_View
5593 Loc : constant Source_Ptr := Sloc (N);
5594 Subt : constant Entity_Id :=
5595 Make_Defining_Identifier
5596 (Loc, New_External_Name (Chars (Typ), 'S'));
5604 if Nkind (N) = N_Full_Type_Declaration then
5605 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
5607 -- ??? ??? is this assert right, I assume so otherwise Constr
5608 -- would not be defined below (this used to be an elsif)
5610 else pragma Assert (Nkind (N) = N_Subtype_Declaration);
5611 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
5614 -- If the constraint has discriminant associations, the discriminant
5615 -- entity is already set, but it denotes a discriminant of the new
5616 -- type, not the original parent, so it must be found anew.
5618 C := First (Constraints (Constr));
5620 while Present (C) loop
5622 if Nkind (C) = N_Discriminant_Association then
5623 Id := First (Selector_Names (C));
5625 while Present (Id) loop
5626 Set_Original_Discriminant (Id, Empty);
5634 Indic := Make_Subtype_Declaration (Loc,
5635 Defining_Identifier => Subt,
5636 Subtype_Indication =>
5637 Make_Subtype_Indication (Loc,
5638 Subtype_Mark => New_Reference_To (Par, Loc),
5639 Constraint => New_Copy_Tree (Constr)));
5641 Insert_Before (N, Indic);
5643 Set_Underlying_Full_View (Typ, Full_View (Subt));
5644 end Build_Underlying_Full_View;
5646 -------------------------------
5647 -- Check_Abstract_Overriding --
5648 -------------------------------
5650 procedure Check_Abstract_Overriding (T : Entity_Id) is
5657 Op_List := Primitive_Operations (T);
5659 -- Loop to check primitive operations
5661 Elmt := First_Elmt (Op_List);
5662 while Present (Elmt) loop
5663 Subp := Node (Elmt);
5665 -- Special exception, do not complain about failure to
5666 -- override _Input and _Output, since we always provide
5667 -- automatic overridings for these subprograms.
5669 if Is_Abstract (Subp)
5670 and then Chars (Subp) /= Name_uInput
5671 and then Chars (Subp) /= Name_uOutput
5672 and then not Is_Abstract (T)
5674 if Present (Alias (Subp)) then
5675 -- Only perform the check for a derived subprogram when
5676 -- the type has an explicit record extension. This avoids
5677 -- incorrectly flagging abstract subprograms for the case
5678 -- of a type without an extension derived from a formal type
5679 -- with a tagged actual (can occur within a private part).
5681 Type_Def := Type_Definition (Parent (T));
5682 if Nkind (Type_Def) = N_Derived_Type_Definition
5683 and then Present (Record_Extension_Part (Type_Def))
5686 ("type must be declared abstract or & overridden",
5691 ("abstract subprogram not allowed for type&",
5694 ("nonabstract type has abstract subprogram&",
5701 end Check_Abstract_Overriding;
5703 ------------------------------------------------
5704 -- Check_Access_Discriminant_Requires_Limited --
5705 ------------------------------------------------
5707 procedure Check_Access_Discriminant_Requires_Limited
5712 -- A discriminant_specification for an access discriminant
5713 -- shall appear only in the declaration for a task or protected
5714 -- type, or for a type with the reserved word 'limited' in
5715 -- its definition or in one of its ancestors. (RM 3.7(10))
5717 if Nkind (Discriminant_Type (D)) = N_Access_Definition
5718 and then not Is_Concurrent_Type (Current_Scope)
5719 and then not Is_Concurrent_Record_Type (Current_Scope)
5720 and then not Is_Limited_Record (Current_Scope)
5721 and then Ekind (Current_Scope) /= E_Limited_Private_Type
5724 ("access discriminants allowed only for limited types", Loc);
5726 end Check_Access_Discriminant_Requires_Limited;
5728 -----------------------------------
5729 -- Check_Aliased_Component_Types --
5730 -----------------------------------
5732 procedure Check_Aliased_Component_Types (T : Entity_Id) is
5736 -- ??? Also need to check components of record extensions,
5737 -- but not components of protected types (which are always
5740 if not Is_Limited_Type (T) then
5741 if Ekind (T) = E_Record_Type then
5742 C := First_Component (T);
5743 while Present (C) loop
5745 and then Has_Discriminants (Etype (C))
5746 and then not Is_Constrained (Etype (C))
5747 and then not In_Instance
5750 ("aliased component must be constrained ('R'M 3.6(11))",
5757 elsif Ekind (T) = E_Array_Type then
5758 if Has_Aliased_Components (T)
5759 and then Has_Discriminants (Component_Type (T))
5760 and then not Is_Constrained (Component_Type (T))
5761 and then not In_Instance
5764 ("aliased component type must be constrained ('R'M 3.6(11))",
5769 end Check_Aliased_Component_Types;
5771 ----------------------
5772 -- Check_Completion --
5773 ----------------------
5775 procedure Check_Completion (Body_Id : Node_Id := Empty) is
5778 procedure Post_Error;
5779 -- Post error message for lack of completion for entity E
5781 procedure Post_Error is
5783 if not Comes_From_Source (E) then
5785 if (Ekind (E) = E_Task_Type
5786 or else Ekind (E) = E_Protected_Type)
5788 -- It may be an anonymous protected type created for a
5789 -- single variable. Post error on variable, if present.
5795 Var := First_Entity (Current_Scope);
5797 while Present (Var) loop
5798 exit when Etype (Var) = E
5799 and then Comes_From_Source (Var);
5804 if Present (Var) then
5811 -- If a generated entity has no completion, then either previous
5812 -- semantic errors have disabled the expansion phase, or else
5813 -- we had missing subunits, or else we are compiling without expan-
5814 -- sion, or else something is very wrong.
5816 if not Comes_From_Source (E) then
5818 (Errors_Detected > 0
5819 or else Subunits_Missing
5820 or else not Expander_Active);
5823 -- Here for source entity
5826 -- Here if no body to post the error message, so we post the error
5827 -- on the declaration that has no completion. This is not really
5828 -- the right place to post it, think about this later ???
5830 if No (Body_Id) then
5833 ("missing full declaration for }", Parent (E), E);
5836 ("missing body for &", Parent (E), E);
5839 -- Package body has no completion for a declaration that appears
5840 -- in the corresponding spec. Post error on the body, with a
5841 -- reference to the non-completed declaration.
5844 Error_Msg_Sloc := Sloc (E);
5848 ("missing full declaration for }!", Body_Id, E);
5850 elsif Is_Overloadable (E)
5851 and then Current_Entity_In_Scope (E) /= E
5853 -- It may be that the completion is mistyped and appears
5854 -- as a distinct overloading of the entity.
5857 Candidate : Entity_Id := Current_Entity_In_Scope (E);
5858 Decl : Node_Id := Unit_Declaration_Node (Candidate);
5861 if Is_Overloadable (Candidate)
5862 and then Ekind (Candidate) = Ekind (E)
5863 and then Nkind (Decl) = N_Subprogram_Body
5864 and then Acts_As_Spec (Decl)
5866 Check_Type_Conformant (Candidate, E);
5869 Error_Msg_NE ("missing body for & declared#!",
5874 Error_Msg_NE ("missing body for & declared#!",
5881 -- Start processing for Check_Completion
5884 E := First_Entity (Current_Scope);
5885 while Present (E) loop
5886 if Is_Intrinsic_Subprogram (E) then
5889 -- The following situation requires special handling: a child
5890 -- unit that appears in the context clause of the body of its
5893 -- procedure Parent.Child (...);
5895 -- with Parent.Child;
5896 -- package body Parent is
5898 -- Here Parent.Child appears as a local entity, but should not
5899 -- be flagged as requiring completion, because it is a
5900 -- compilation unit.
5902 elsif Ekind (E) = E_Function
5903 or else Ekind (E) = E_Procedure
5904 or else Ekind (E) = E_Generic_Function
5905 or else Ekind (E) = E_Generic_Procedure
5907 if not Has_Completion (E)
5908 and then not Is_Abstract (E)
5909 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5911 and then Chars (E) /= Name_uSize
5916 elsif Is_Entry (E) then
5917 if not Has_Completion (E) and then
5918 (Ekind (Scope (E)) = E_Protected_Object
5919 or else Ekind (Scope (E)) = E_Protected_Type)
5924 elsif Is_Package (E) then
5925 if Unit_Requires_Body (E) then
5926 if not Has_Completion (E)
5927 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5933 elsif not Is_Child_Unit (E) then
5934 May_Need_Implicit_Body (E);
5937 elsif Ekind (E) = E_Incomplete_Type
5938 and then No (Underlying_Type (E))
5942 elsif (Ekind (E) = E_Task_Type or else
5943 Ekind (E) = E_Protected_Type)
5944 and then not Has_Completion (E)
5948 elsif Ekind (E) = E_Constant
5949 and then Ekind (Etype (E)) = E_Task_Type
5950 and then not Has_Completion (Etype (E))
5954 elsif Ekind (E) = E_Protected_Object
5955 and then not Has_Completion (Etype (E))
5959 elsif Ekind (E) = E_Record_Type then
5960 if Is_Tagged_Type (E) then
5961 Check_Abstract_Overriding (E);
5964 Check_Aliased_Component_Types (E);
5966 elsif Ekind (E) = E_Array_Type then
5967 Check_Aliased_Component_Types (E);
5973 end Check_Completion;
5975 ----------------------------
5976 -- Check_Delta_Expression --
5977 ----------------------------
5979 procedure Check_Delta_Expression (E : Node_Id) is
5981 if not (Is_Real_Type (Etype (E))) then
5982 Wrong_Type (E, Any_Real);
5984 elsif not Is_OK_Static_Expression (E) then
5985 Error_Msg_N ("non-static expression used for delta value", E);
5987 elsif not UR_Is_Positive (Expr_Value_R (E)) then
5988 Error_Msg_N ("delta expression must be positive", E);
5994 -- If any of above errors occurred, then replace the incorrect
5995 -- expression by the real 0.1, which should prevent further errors.
5998 Make_Real_Literal (Sloc (E), Ureal_Tenth));
5999 Analyze_And_Resolve (E, Standard_Float);
6001 end Check_Delta_Expression;
6003 -----------------------------
6004 -- Check_Digits_Expression --
6005 -----------------------------
6007 procedure Check_Digits_Expression (E : Node_Id) is
6009 if not (Is_Integer_Type (Etype (E))) then
6010 Wrong_Type (E, Any_Integer);
6012 elsif not Is_OK_Static_Expression (E) then
6013 Error_Msg_N ("non-static expression used for digits value", E);
6015 elsif Expr_Value (E) <= 0 then
6016 Error_Msg_N ("digits value must be greater than zero", E);
6022 -- If any of above errors occurred, then replace the incorrect
6023 -- expression by the integer 1, which should prevent further errors.
6025 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
6026 Analyze_And_Resolve (E, Standard_Integer);
6028 end Check_Digits_Expression;
6030 ----------------------
6031 -- Check_Incomplete --
6032 ----------------------
6034 procedure Check_Incomplete (T : Entity_Id) is
6036 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
6037 Error_Msg_N ("invalid use of type before its full declaration", T);
6039 end Check_Incomplete;
6041 --------------------------
6042 -- Check_Initialization --
6043 --------------------------
6045 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
6047 if (Is_Limited_Type (T)
6048 or else Is_Limited_Composite (T))
6049 and then not In_Instance
6052 ("cannot initialize entities of limited type", Exp);
6054 end Check_Initialization;
6056 ------------------------------------
6057 -- Check_Or_Process_Discriminants --
6058 ------------------------------------
6060 -- If an incomplete or private type declaration was already given for
6061 -- the type, the discriminants may have already been processed if they
6062 -- were present on the incomplete declaration. In this case a full
6063 -- conformance check is performed otherwise just process them.
6065 procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id) is
6067 if Has_Discriminants (T) then
6069 -- Make the discriminants visible to component declarations.
6072 D : Entity_Id := First_Discriminant (T);
6076 while Present (D) loop
6077 Prev := Current_Entity (D);
6078 Set_Current_Entity (D);
6079 Set_Is_Immediately_Visible (D);
6080 Set_Homonym (D, Prev);
6082 -- This restriction gets applied to the full type here; it
6083 -- has already been applied earlier to the partial view
6085 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6087 Next_Discriminant (D);
6091 elsif Present (Discriminant_Specifications (N)) then
6092 Process_Discriminants (N);
6094 end Check_Or_Process_Discriminants;
6096 ----------------------
6097 -- Check_Real_Bound --
6098 ----------------------
6100 procedure Check_Real_Bound (Bound : Node_Id) is
6102 if not Is_Real_Type (Etype (Bound)) then
6104 ("bound in real type definition must be of real type", Bound);
6106 elsif not Is_OK_Static_Expression (Bound) then
6108 ("non-static expression used for real type bound", Bound);
6115 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6117 Resolve (Bound, Standard_Float);
6118 end Check_Real_Bound;
6120 ------------------------------
6121 -- Complete_Private_Subtype --
6122 ------------------------------
6124 procedure Complete_Private_Subtype
6127 Full_Base : Entity_Id;
6128 Related_Nod : Node_Id)
6130 Save_Next_Entity : Entity_Id;
6131 Save_Homonym : Entity_Id;
6134 -- Set semantic attributes for (implicit) private subtype completion.
6135 -- If the full type has no discriminants, then it is a copy of the full
6136 -- view of the base. Otherwise, it is a subtype of the base with a
6137 -- possible discriminant constraint. Save and restore the original
6138 -- Next_Entity field of full to ensure that the calls to Copy_Node
6139 -- do not corrupt the entity chain.
6141 -- Note that the type of the full view is the same entity as the
6142 -- type of the partial view. In this fashion, the subtype has
6143 -- access to the correct view of the parent.
6145 Save_Next_Entity := Next_Entity (Full);
6146 Save_Homonym := Homonym (Priv);
6148 case Ekind (Full_Base) is
6150 when E_Record_Type |
6156 Copy_Node (Priv, Full);
6158 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6159 Set_First_Entity (Full, First_Entity (Full_Base));
6160 Set_Last_Entity (Full, Last_Entity (Full_Base));
6163 Copy_Node (Full_Base, Full);
6164 Set_Chars (Full, Chars (Priv));
6165 Conditional_Delay (Full, Priv);
6166 Set_Sloc (Full, Sloc (Priv));
6170 Set_Next_Entity (Full, Save_Next_Entity);
6171 Set_Homonym (Full, Save_Homonym);
6172 Set_Associated_Node_For_Itype (Full, Related_Nod);
6174 -- Set common attributes for all subtypes.
6176 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6178 -- The Etype of the full view is inconsistent. Gigi needs to see the
6179 -- structural full view, which is what the current scheme gives:
6180 -- the Etype of the full view is the etype of the full base. However,
6181 -- if the full base is a derived type, the full view then looks like
6182 -- a subtype of the parent, not a subtype of the full base. If instead
6185 -- Set_Etype (Full, Full_Base);
6187 -- then we get inconsistencies in the front-end (confusion between
6188 -- views). Several outstanding bugs are related to this.
6190 Set_Is_First_Subtype (Full, False);
6191 Set_Scope (Full, Scope (Priv));
6192 Set_Size_Info (Full, Full_Base);
6193 Set_RM_Size (Full, RM_Size (Full_Base));
6194 Set_Is_Itype (Full);
6196 -- A subtype of a private-type-without-discriminants, whose full-view
6197 -- has discriminants with default expressions, is not constrained!
6199 if not Has_Discriminants (Priv) then
6200 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6203 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6204 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6206 -- Freeze the private subtype entity if its parent is delayed,
6207 -- and not already frozen. We skip this processing if the type
6208 -- is an anonymous subtype of a record component, or is the
6209 -- corresponding record of a protected type, since ???
6211 if not Is_Type (Scope (Full)) then
6212 Set_Has_Delayed_Freeze (Full,
6213 Has_Delayed_Freeze (Full_Base)
6214 and then (not Is_Frozen (Full_Base)));
6217 Set_Freeze_Node (Full, Empty);
6218 Set_Is_Frozen (Full, False);
6219 Set_Full_View (Priv, Full);
6221 if Has_Discriminants (Full) then
6222 Set_Girder_Constraint_From_Discriminant_Constraint (Full);
6223 Set_Girder_Constraint (Priv, Girder_Constraint (Full));
6224 if Has_Unknown_Discriminants (Full) then
6225 Set_Discriminant_Constraint (Full, No_Elist);
6229 if Ekind (Full_Base) = E_Record_Type
6230 and then Has_Discriminants (Full_Base)
6231 and then Has_Discriminants (Priv) -- might not, if errors
6232 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
6234 Create_Constrained_Components
6235 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
6237 -- If the full base is itself derived from private, build a congruent
6238 -- subtype of its underlying type, for use by the back end.
6240 elsif Ekind (Full_Base) in Private_Kind
6241 and then Is_Derived_Type (Full_Base)
6242 and then Has_Discriminants (Full_Base)
6244 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
6246 Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
6248 elsif Is_Record_Type (Full_Base) then
6250 -- Show Full is simply a renaming of Full_Base.
6252 Set_Cloned_Subtype (Full, Full_Base);
6255 -- It is usafe to share to bounds of a scalar type, because the
6256 -- Itype is elaborated on demand, and if a bound is non-static
6257 -- then different orders of elaboration in different units will
6258 -- lead to different external symbols.
6260 if Is_Scalar_Type (Full_Base) then
6261 Set_Scalar_Range (Full,
6262 Make_Range (Sloc (Related_Nod),
6263 Low_Bound => Duplicate_Subexpr (Type_Low_Bound (Full_Base)),
6264 High_Bound => Duplicate_Subexpr (Type_High_Bound (Full_Base))));
6267 -- ??? It seems that a lot of fields are missing that should be
6268 -- copied from Full_Base to Full. Here are some that are introduced
6269 -- in a non-disruptive way but a cleanup is necessary.
6271 if Is_Tagged_Type (Full_Base) then
6272 Set_Is_Tagged_Type (Full);
6273 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
6275 elsif Is_Concurrent_Type (Full_Base) then
6277 if Has_Discriminants (Full)
6278 and then Present (Corresponding_Record_Type (Full_Base))
6280 Set_Corresponding_Record_Type (Full,
6281 Constrain_Corresponding_Record
6282 (Full, Corresponding_Record_Type (Full_Base),
6283 Related_Nod, Full_Base));
6286 Set_Corresponding_Record_Type (Full,
6287 Corresponding_Record_Type (Full_Base));
6291 end Complete_Private_Subtype;
6293 ----------------------------
6294 -- Constant_Redeclaration --
6295 ----------------------------
6297 procedure Constant_Redeclaration
6302 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
6303 Obj_Def : constant Node_Id := Object_Definition (N);
6307 if Nkind (Parent (Prev)) = N_Object_Declaration then
6308 if Nkind (Object_Definition
6309 (Parent (Prev))) = N_Subtype_Indication
6311 -- Find type of new declaration. The constraints of the two
6312 -- views must match statically, but there is no point in
6313 -- creating an itype for the full view.
6315 if Nkind (Obj_Def) = N_Subtype_Indication then
6316 Find_Type (Subtype_Mark (Obj_Def));
6317 New_T := Entity (Subtype_Mark (Obj_Def));
6320 Find_Type (Obj_Def);
6321 New_T := Entity (Obj_Def);
6327 -- The full view may impose a constraint, even if the partial
6328 -- view does not, so construct the subtype.
6330 New_T := Find_Type_Of_Object (Obj_Def, N);
6335 -- Current declaration is illegal, diagnosed below in Enter_Name.
6341 -- If previous full declaration exists, or if a homograph is present,
6342 -- let Enter_Name handle it, either with an error, or with the removal
6343 -- of an overridden implicit subprogram.
6345 if Ekind (Prev) /= E_Constant
6346 or else Present (Expression (Parent (Prev)))
6350 -- Verify that types of both declarations match.
6352 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
6353 Error_Msg_Sloc := Sloc (Prev);
6354 Error_Msg_N ("type does not match declaration#", N);
6355 Set_Full_View (Prev, Id);
6356 Set_Etype (Id, Any_Type);
6358 -- If so, process the full constant declaration
6361 Set_Full_View (Prev, Id);
6362 Set_Is_Public (Id, Is_Public (Prev));
6363 Set_Is_Internal (Id);
6364 Append_Entity (Id, Current_Scope);
6366 -- Check ALIASED present if present before (RM 7.4(7))
6368 if Is_Aliased (Prev)
6369 and then not Aliased_Present (N)
6371 Error_Msg_Sloc := Sloc (Prev);
6372 Error_Msg_N ("ALIASED required (see declaration#)", N);
6375 -- Check that placement is in private part
6377 if Ekind (Current_Scope) = E_Package
6378 and then not In_Private_Part (Current_Scope)
6380 Error_Msg_Sloc := Sloc (Prev);
6381 Error_Msg_N ("full constant for declaration#"
6382 & " must be in private part", N);
6385 end Constant_Redeclaration;
6387 ----------------------
6388 -- Constrain_Access --
6389 ----------------------
6391 procedure Constrain_Access
6392 (Def_Id : in out Entity_Id;
6394 Related_Nod : Node_Id)
6396 T : constant Entity_Id := Entity (Subtype_Mark (S));
6397 Desig_Type : constant Entity_Id := Designated_Type (T);
6398 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
6399 Constraint_OK : Boolean := True;
6402 if Is_Array_Type (Desig_Type) then
6403 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
6405 elsif (Is_Record_Type (Desig_Type)
6406 or else Is_Incomplete_Or_Private_Type (Desig_Type))
6407 and then not Is_Constrained (Desig_Type)
6409 -- ??? The following code is a temporary kludge to ignore
6410 -- discriminant constraint on access type if
6411 -- it is constraining the current record. Avoid creating the
6412 -- implicit subtype of the record we are currently compiling
6413 -- since right now, we cannot handle these.
6414 -- For now, just return the access type itself.
6416 if Desig_Type = Current_Scope
6417 and then No (Def_Id)
6419 Set_Ekind (Desig_Subtype, E_Record_Subtype);
6420 Def_Id := Entity (Subtype_Mark (S));
6422 -- This call added to ensure that the constraint is
6423 -- analyzed (needed for a B test). Note that we
6424 -- still return early from this procedure to avoid
6425 -- recursive processing. ???
6427 Constrain_Discriminated_Type
6428 (Desig_Subtype, S, Related_Nod, For_Access => True);
6433 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
6434 For_Access => True);
6436 elsif (Is_Task_Type (Desig_Type)
6437 or else Is_Protected_Type (Desig_Type))
6438 and then not Is_Constrained (Desig_Type)
6440 Constrain_Concurrent
6441 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
6444 Error_Msg_N ("invalid constraint on access type", S);
6445 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
6446 Constraint_OK := False;
6450 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
6452 Set_Ekind (Def_Id, E_Access_Subtype);
6455 if Constraint_OK then
6456 Set_Etype (Def_Id, Base_Type (T));
6458 if Is_Private_Type (Desig_Type) then
6459 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
6462 Set_Etype (Def_Id, Any_Type);
6465 Set_Size_Info (Def_Id, T);
6466 Set_Is_Constrained (Def_Id, Constraint_OK);
6467 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
6468 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6469 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
6471 -- Itypes created for constrained record components do not receive
6472 -- a freeze node, they are elaborated when first seen.
6474 if not Is_Record_Type (Current_Scope) then
6475 Conditional_Delay (Def_Id, T);
6477 end Constrain_Access;
6479 ---------------------
6480 -- Constrain_Array --
6481 ---------------------
6483 procedure Constrain_Array
6484 (Def_Id : in out Entity_Id;
6486 Related_Nod : Node_Id;
6487 Related_Id : Entity_Id;
6490 C : constant Node_Id := Constraint (SI);
6491 Number_Of_Constraints : Nat := 0;
6494 Constraint_OK : Boolean := True;
6497 T := Entity (Subtype_Mark (SI));
6499 if Ekind (T) in Access_Kind then
6500 T := Designated_Type (T);
6503 -- If an index constraint follows a subtype mark in a subtype indication
6504 -- then the type or subtype denoted by the subtype mark must not already
6505 -- impose an index constraint. The subtype mark must denote either an
6506 -- unconstrained array type or an access type whose designated type
6507 -- is such an array type... (RM 3.6.1)
6509 if Is_Constrained (T) then
6511 ("array type is already constrained", Subtype_Mark (SI));
6512 Constraint_OK := False;
6515 S := First (Constraints (C));
6517 while Present (S) loop
6518 Number_Of_Constraints := Number_Of_Constraints + 1;
6522 -- In either case, the index constraint must provide a discrete
6523 -- range for each index of the array type and the type of each
6524 -- discrete range must be the same as that of the corresponding
6525 -- index. (RM 3.6.1)
6527 if Number_Of_Constraints /= Number_Dimensions (T) then
6528 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
6529 Constraint_OK := False;
6532 S := First (Constraints (C));
6533 Index := First_Index (T);
6536 -- Apply constraints to each index type
6538 for J in 1 .. Number_Of_Constraints loop
6539 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
6549 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
6551 Set_Ekind (Def_Id, E_Array_Subtype);
6554 Set_Size_Info (Def_Id, (T));
6555 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6556 Set_Etype (Def_Id, Base_Type (T));
6558 if Constraint_OK then
6559 Set_First_Index (Def_Id, First (Constraints (C)));
6562 Set_Component_Type (Def_Id, Component_Type (T));
6563 Set_Is_Constrained (Def_Id, True);
6564 Set_Is_Aliased (Def_Id, Is_Aliased (T));
6565 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6567 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
6568 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
6570 -- If the subtype is not that of a record component, build a freeze
6571 -- node if parent still needs one.
6573 -- If the subtype is not that of a record component, make sure
6574 -- that the Depends_On_Private status is set (explanation ???)
6575 -- and also that a conditional delay is set.
6577 if not Is_Type (Scope (Def_Id)) then
6578 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6579 Conditional_Delay (Def_Id, T);
6582 end Constrain_Array;
6584 ------------------------------
6585 -- Constrain_Component_Type --
6586 ------------------------------
6588 function Constrain_Component_Type
6589 (Compon_Type : Entity_Id;
6590 Constrained_Typ : Entity_Id;
6591 Related_Node : Node_Id;
6593 Constraints : Elist_Id)
6596 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
6598 function Build_Constrained_Array_Type
6599 (Old_Type : Entity_Id)
6601 -- If Old_Type is an array type, one of whose indices is
6602 -- constrained by a discriminant, build an Itype whose constraint
6603 -- replaces the discriminant with its value in the constraint.
6605 function Build_Constrained_Discriminated_Type
6606 (Old_Type : Entity_Id)
6608 -- Ditto for record components.
6610 function Build_Constrained_Access_Type
6611 (Old_Type : Entity_Id)
6613 -- Ditto for access types. Makes use of previous two functions, to
6614 -- constrain designated type.
6616 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
6617 -- T is an array or discriminated type, C is a list of constraints
6618 -- that apply to T. This routine builds the constrained subtype.
6620 function Is_Discriminant (Expr : Node_Id) return Boolean;
6621 -- Returns True if Expr is a discriminant.
6623 function Get_Value (Discrim : Entity_Id) return Node_Id;
6624 -- Find the value of discriminant Discrim in Constraint.
6626 -----------------------------------
6627 -- Build_Constrained_Access_Type --
6628 -----------------------------------
6630 function Build_Constrained_Access_Type
6631 (Old_Type : Entity_Id)
6634 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
6636 Desig_Subtype : Entity_Id;
6640 -- if the original access type was not embedded in the enclosing
6641 -- type definition, there is no need to produce a new access
6642 -- subtype. In fact every access type with an explicit constraint
6643 -- generates an itype whose scope is the enclosing record.
6645 if not Is_Type (Scope (Old_Type)) then
6648 elsif Is_Array_Type (Desig_Type) then
6649 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
6651 elsif Has_Discriminants (Desig_Type) then
6653 -- This may be an access type to an enclosing record type for
6654 -- which we are constructing the constrained components. Return
6655 -- the enclosing record subtype. This is not always correct,
6656 -- but avoids infinite recursion. ???
6658 Desig_Subtype := Any_Type;
6660 for J in reverse 0 .. Scope_Stack.Last loop
6661 Scop := Scope_Stack.Table (J).Entity;
6664 and then Base_Type (Scop) = Base_Type (Desig_Type)
6666 Desig_Subtype := Scop;
6669 exit when not Is_Type (Scop);
6672 if Desig_Subtype = Any_Type then
6674 Build_Constrained_Discriminated_Type (Desig_Type);
6681 if Desig_Subtype /= Desig_Type then
6682 -- The Related_Node better be here or else we won't be able
6683 -- to attach new itypes to a node in the tree.
6685 pragma Assert (Present (Related_Node));
6687 Itype := Create_Itype (E_Access_Subtype, Related_Node);
6689 Set_Etype (Itype, Base_Type (Old_Type));
6690 Set_Size_Info (Itype, (Old_Type));
6691 Set_Directly_Designated_Type (Itype, Desig_Subtype);
6692 Set_Depends_On_Private (Itype, Has_Private_Component
6694 Set_Is_Access_Constant (Itype, Is_Access_Constant
6697 -- The new itype needs freezing when it depends on a not frozen
6698 -- type and the enclosing subtype needs freezing.
6700 if Has_Delayed_Freeze (Constrained_Typ)
6701 and then not Is_Frozen (Constrained_Typ)
6703 Conditional_Delay (Itype, Base_Type (Old_Type));
6711 end Build_Constrained_Access_Type;
6713 ----------------------------------
6714 -- Build_Constrained_Array_Type --
6715 ----------------------------------
6717 function Build_Constrained_Array_Type
6718 (Old_Type : Entity_Id)
6723 Old_Index : Node_Id;
6724 Range_Node : Node_Id;
6725 Constr_List : List_Id;
6727 Need_To_Create_Itype : Boolean := False;
6730 Old_Index := First_Index (Old_Type);
6731 while Present (Old_Index) loop
6732 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6734 if Is_Discriminant (Lo_Expr)
6735 or else Is_Discriminant (Hi_Expr)
6737 Need_To_Create_Itype := True;
6740 Next_Index (Old_Index);
6743 if Need_To_Create_Itype then
6744 Constr_List := New_List;
6746 Old_Index := First_Index (Old_Type);
6747 while Present (Old_Index) loop
6748 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6750 if Is_Discriminant (Lo_Expr) then
6751 Lo_Expr := Get_Value (Lo_Expr);
6754 if Is_Discriminant (Hi_Expr) then
6755 Hi_Expr := Get_Value (Hi_Expr);
6760 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
6762 Append (Range_Node, To => Constr_List);
6764 Next_Index (Old_Index);
6767 return Build_Subtype (Old_Type, Constr_List);
6772 end Build_Constrained_Array_Type;
6774 ------------------------------------------
6775 -- Build_Constrained_Discriminated_Type --
6776 ------------------------------------------
6778 function Build_Constrained_Discriminated_Type
6779 (Old_Type : Entity_Id)
6783 Constr_List : List_Id;
6784 Old_Constraint : Elmt_Id;
6786 Need_To_Create_Itype : Boolean := False;
6789 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6790 while Present (Old_Constraint) loop
6791 Expr := Node (Old_Constraint);
6793 if Is_Discriminant (Expr) then
6794 Need_To_Create_Itype := True;
6797 Next_Elmt (Old_Constraint);
6800 if Need_To_Create_Itype then
6801 Constr_List := New_List;
6803 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6804 while Present (Old_Constraint) loop
6805 Expr := Node (Old_Constraint);
6807 if Is_Discriminant (Expr) then
6808 Expr := Get_Value (Expr);
6811 Append (New_Copy_Tree (Expr), To => Constr_List);
6813 Next_Elmt (Old_Constraint);
6816 return Build_Subtype (Old_Type, Constr_List);
6821 end Build_Constrained_Discriminated_Type;
6827 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
6829 Subtyp_Decl : Node_Id;
6831 Btyp : Entity_Id := Base_Type (T);
6834 -- The Related_Node better be here or else we won't be able
6835 -- to attach new itypes to a node in the tree.
6837 pragma Assert (Present (Related_Node));
6839 -- If the view of the component's type is incomplete or private
6840 -- with unknown discriminants, then the constraint must be applied
6841 -- to the full type.
6843 if Has_Unknown_Discriminants (Btyp)
6844 and then Present (Underlying_Type (Btyp))
6846 Btyp := Underlying_Type (Btyp);
6850 Make_Subtype_Indication (Loc,
6851 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
6852 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
6854 Def_Id := Create_Itype (Ekind (T), Related_Node);
6857 Make_Subtype_Declaration (Loc,
6858 Defining_Identifier => Def_Id,
6859 Subtype_Indication => Indic);
6860 Set_Parent (Subtyp_Decl, Parent (Related_Node));
6862 -- Itypes must be analyzed with checks off (see itypes.ads).
6864 Analyze (Subtyp_Decl, Suppress => All_Checks);
6873 function Get_Value (Discrim : Entity_Id) return Node_Id is
6874 D : Entity_Id := First_Discriminant (Typ);
6875 E : Elmt_Id := First_Elmt (Constraints);
6878 while Present (D) loop
6880 -- If we are constraining the subtype of a derived tagged type,
6881 -- recover the discriminant of the parent, which appears in
6882 -- the constraint of an inherited component.
6884 if D = Entity (Discrim)
6885 or else Corresponding_Discriminant (D) = Entity (Discrim)
6890 Next_Discriminant (D);
6894 -- Something is wrong if we did not find the value
6896 raise Program_Error;
6899 ---------------------
6900 -- Is_Discriminant --
6901 ---------------------
6903 function Is_Discriminant (Expr : Node_Id) return Boolean is
6904 Discrim_Scope : Entity_Id;
6907 if Denotes_Discriminant (Expr) then
6908 Discrim_Scope := Scope (Entity (Expr));
6910 -- Either we have a reference to one of Typ's discriminants,
6912 pragma Assert (Discrim_Scope = Typ
6914 -- or to the discriminants of the parent type, in the case
6915 -- of a derivation of a tagged type with variants.
6917 or else Discrim_Scope = Etype (Typ)
6918 or else Full_View (Discrim_Scope) = Etype (Typ)
6920 -- or same as above for the case where the discriminants
6921 -- were declared in Typ's private view.
6923 or else (Is_Private_Type (Discrim_Scope)
6924 and then Chars (Discrim_Scope) = Chars (Typ))
6926 -- or else we are deriving from the full view and the
6927 -- discriminant is declared in the private entity.
6929 or else (Is_Private_Type (Typ)
6930 and then Chars (Discrim_Scope) = Chars (Typ))
6932 -- or we have a class-wide type, in which case make sure the
6933 -- discriminant found belongs to the root type.
6935 or else (Is_Class_Wide_Type (Typ)
6936 and then Etype (Typ) = Discrim_Scope));
6941 -- In all other cases we have something wrong.
6944 end Is_Discriminant;
6946 -- Start of processing for Constrain_Component_Type
6949 if Is_Array_Type (Compon_Type) then
6950 return Build_Constrained_Array_Type (Compon_Type);
6952 elsif Has_Discriminants (Compon_Type) then
6953 return Build_Constrained_Discriminated_Type (Compon_Type);
6955 elsif Is_Access_Type (Compon_Type) then
6956 return Build_Constrained_Access_Type (Compon_Type);
6960 end Constrain_Component_Type;
6962 --------------------------
6963 -- Constrain_Concurrent --
6964 --------------------------
6966 -- For concurrent types, the associated record value type carries the same
6967 -- discriminants, so when we constrain a concurrent type, we must constrain
6968 -- the value type as well.
6970 procedure Constrain_Concurrent
6971 (Def_Id : in out Entity_Id;
6973 Related_Nod : Node_Id;
6974 Related_Id : Entity_Id;
6977 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
6981 if Ekind (T_Ent) in Access_Kind then
6982 T_Ent := Designated_Type (T_Ent);
6985 T_Val := Corresponding_Record_Type (T_Ent);
6987 if Present (T_Val) then
6990 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6993 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
6995 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6996 Set_Corresponding_Record_Type (Def_Id,
6997 Constrain_Corresponding_Record
6998 (Def_Id, T_Val, Related_Nod, Related_Id));
7001 -- If there is no associated record, expansion is disabled and this
7002 -- is a generic context. Create a subtype in any case, so that
7003 -- semantic analysis can proceed.
7006 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7009 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7011 end Constrain_Concurrent;
7013 ------------------------------------
7014 -- Constrain_Corresponding_Record --
7015 ------------------------------------
7017 function Constrain_Corresponding_Record
7018 (Prot_Subt : Entity_Id;
7019 Corr_Rec : Entity_Id;
7020 Related_Nod : Node_Id;
7021 Related_Id : Entity_Id)
7024 T_Sub : constant Entity_Id
7025 := Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
7028 Set_Etype (T_Sub, Corr_Rec);
7029 Init_Size_Align (T_Sub);
7030 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
7031 Set_Is_Constrained (T_Sub, True);
7032 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
7033 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
7035 Conditional_Delay (T_Sub, Corr_Rec);
7037 if Has_Discriminants (Prot_Subt) then -- False only if errors.
7038 Set_Discriminant_Constraint (T_Sub,
7039 Discriminant_Constraint (Prot_Subt));
7040 Set_Girder_Constraint_From_Discriminant_Constraint (T_Sub);
7041 Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
7042 Discriminant_Constraint (T_Sub));
7045 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
7048 end Constrain_Corresponding_Record;
7050 -----------------------
7051 -- Constrain_Decimal --
7052 -----------------------
7054 procedure Constrain_Decimal
7057 Related_Nod : Node_Id)
7059 T : constant Entity_Id := Entity (Subtype_Mark (S));
7060 C : constant Node_Id := Constraint (S);
7061 Loc : constant Source_Ptr := Sloc (C);
7062 Range_Expr : Node_Id;
7063 Digits_Expr : Node_Id;
7068 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7070 if Nkind (C) = N_Range_Constraint then
7071 Range_Expr := Range_Expression (C);
7072 Digits_Val := Digits_Value (T);
7075 pragma Assert (Nkind (C) = N_Digits_Constraint);
7076 Digits_Expr := Digits_Expression (C);
7077 Analyze_And_Resolve (Digits_Expr, Any_Integer);
7079 Check_Digits_Expression (Digits_Expr);
7080 Digits_Val := Expr_Value (Digits_Expr);
7082 if Digits_Val > Digits_Value (T) then
7084 ("digits expression is incompatible with subtype", C);
7085 Digits_Val := Digits_Value (T);
7088 if Present (Range_Constraint (C)) then
7089 Range_Expr := Range_Expression (Range_Constraint (C));
7091 Range_Expr := Empty;
7095 Set_Etype (Def_Id, Base_Type (T));
7096 Set_Size_Info (Def_Id, (T));
7097 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7098 Set_Delta_Value (Def_Id, Delta_Value (T));
7099 Set_Scale_Value (Def_Id, Scale_Value (T));
7100 Set_Small_Value (Def_Id, Small_Value (T));
7101 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
7102 Set_Digits_Value (Def_Id, Digits_Val);
7104 -- Manufacture range from given digits value if no range present
7106 if No (Range_Expr) then
7107 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
7111 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
7113 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
7117 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T, Related_Nod);
7118 Set_Discrete_RM_Size (Def_Id);
7120 -- Unconditionally delay the freeze, since we cannot set size
7121 -- information in all cases correctly until the freeze point.
7123 Set_Has_Delayed_Freeze (Def_Id);
7124 end Constrain_Decimal;
7126 ----------------------------------
7127 -- Constrain_Discriminated_Type --
7128 ----------------------------------
7130 procedure Constrain_Discriminated_Type
7131 (Def_Id : Entity_Id;
7133 Related_Nod : Node_Id;
7134 For_Access : Boolean := False)
7138 Elist : Elist_Id := New_Elmt_List;
7140 procedure Fixup_Bad_Constraint;
7141 -- This is called after finding a bad constraint, and after having
7142 -- posted an appropriate error message. The mission is to leave the
7143 -- entity T in as reasonable state as possible!
7145 procedure Fixup_Bad_Constraint is
7147 -- Set a reasonable Ekind for the entity. For an incomplete type,
7148 -- we can't do much, but for other types, we can set the proper
7149 -- corresponding subtype kind.
7151 if Ekind (T) = E_Incomplete_Type then
7152 Set_Ekind (Def_Id, Ekind (T));
7154 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
7157 Set_Etype (Def_Id, Any_Type);
7158 Set_Error_Posted (Def_Id);
7159 end Fixup_Bad_Constraint;
7161 -- Start of processing for Constrain_Discriminated_Type
7164 C := Constraint (S);
7166 -- A discriminant constraint is only allowed in a subtype indication,
7167 -- after a subtype mark. This subtype mark must denote either a type
7168 -- with discriminants, or an access type whose designated type is a
7169 -- type with discriminants. A discriminant constraint specifies the
7170 -- values of these discriminants (RM 3.7.2(5)).
7172 T := Base_Type (Entity (Subtype_Mark (S)));
7174 if Ekind (T) in Access_Kind then
7175 T := Designated_Type (T);
7178 if not Has_Discriminants (T) then
7179 Error_Msg_N ("invalid constraint: type has no discriminant", C);
7180 Fixup_Bad_Constraint;
7183 elsif Is_Constrained (Entity (Subtype_Mark (S))) then
7184 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
7185 Fixup_Bad_Constraint;
7189 -- T may be an unconstrained subtype (e.g. a generic actual).
7190 -- Constraint applies to the base type.
7194 Elist := Build_Discriminant_Constraints (T, S);
7196 -- If the list returned was empty we had an error in building the
7197 -- discriminant constraint. We have also already signalled an error
7198 -- in the incomplete type case
7200 if Is_Empty_Elmt_List (Elist) then
7201 Fixup_Bad_Constraint;
7205 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
7206 end Constrain_Discriminated_Type;
7208 ---------------------------
7209 -- Constrain_Enumeration --
7210 ---------------------------
7212 procedure Constrain_Enumeration
7215 Related_Nod : Node_Id)
7217 T : constant Entity_Id := Entity (Subtype_Mark (S));
7218 C : constant Node_Id := Constraint (S);
7221 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7223 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
7225 Set_Etype (Def_Id, Base_Type (T));
7226 Set_Size_Info (Def_Id, (T));
7227 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7228 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7230 Set_Scalar_Range_For_Subtype
7231 (Def_Id, Range_Expression (C), T, Related_Nod);
7233 Set_Discrete_RM_Size (Def_Id);
7235 end Constrain_Enumeration;
7237 ----------------------
7238 -- Constrain_Float --
7239 ----------------------
7241 procedure Constrain_Float
7244 Related_Nod : Node_Id)
7246 T : constant Entity_Id := Entity (Subtype_Mark (S));
7252 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
7254 Set_Etype (Def_Id, Base_Type (T));
7255 Set_Size_Info (Def_Id, (T));
7256 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7258 -- Process the constraint
7260 C := Constraint (S);
7262 -- Digits constraint present
7264 if Nkind (C) = N_Digits_Constraint then
7265 D := Digits_Expression (C);
7266 Analyze_And_Resolve (D, Any_Integer);
7267 Check_Digits_Expression (D);
7268 Set_Digits_Value (Def_Id, Expr_Value (D));
7270 -- Check that digits value is in range. Obviously we can do this
7271 -- at compile time, but it is strictly a runtime check, and of
7272 -- course there is an ACVC test that checks this!
7274 if Digits_Value (Def_Id) > Digits_Value (T) then
7275 Error_Msg_Uint_1 := Digits_Value (T);
7276 Error_Msg_N ("?digits value is too large, maximum is ^", D);
7277 Rais := Make_Raise_Constraint_Error (Sloc (D));
7278 Insert_Action (Declaration_Node (Def_Id), Rais);
7281 C := Range_Constraint (C);
7283 -- No digits constraint present
7286 Set_Digits_Value (Def_Id, Digits_Value (T));
7289 -- Range constraint present
7291 if Nkind (C) = N_Range_Constraint then
7292 Set_Scalar_Range_For_Subtype
7293 (Def_Id, Range_Expression (C), T, Related_Nod);
7295 -- No range constraint present
7298 pragma Assert (No (C));
7299 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7302 Set_Is_Constrained (Def_Id);
7303 end Constrain_Float;
7305 ---------------------
7306 -- Constrain_Index --
7307 ---------------------
7309 procedure Constrain_Index
7312 Related_Nod : Node_Id;
7313 Related_Id : Entity_Id;
7318 R : Node_Id := Empty;
7319 Checks_Off : Boolean := False;
7320 T : constant Entity_Id := Etype (Index);
7323 if Nkind (S) = N_Range
7324 or else Nkind (S) = N_Attribute_Reference
7326 -- A Range attribute will transformed into N_Range by Resolve.
7332 -- ??? Why on earth do we turn checks of in this very specific case ?
7334 -- From the revision history: (Constrain_Index): Call
7335 -- Process_Range_Expr_In_Decl with range checking off for range
7336 -- bounds that are attributes. This avoids some horrible
7337 -- constraint error checks.
7339 if Nkind (R) = N_Range
7340 and then Nkind (Low_Bound (R)) = N_Attribute_Reference
7341 and then Nkind (High_Bound (R)) = N_Attribute_Reference
7346 Process_Range_Expr_In_Decl
7347 (R, T, Related_Nod, Empty_List, Checks_Off);
7349 if not Error_Posted (S)
7351 (Nkind (S) /= N_Range
7352 or else Base_Type (T) /= Base_Type (Etype (Low_Bound (S)))
7353 or else Base_Type (T) /= Base_Type (Etype (High_Bound (S))))
7355 if Base_Type (T) /= Any_Type
7356 and then Etype (Low_Bound (S)) /= Any_Type
7357 and then Etype (High_Bound (S)) /= Any_Type
7359 Error_Msg_N ("range expected", S);
7363 elsif Nkind (S) = N_Subtype_Indication then
7364 -- the parser has verified that this is a discrete indication.
7366 Resolve_Discrete_Subtype_Indication (S, T);
7367 R := Range_Expression (Constraint (S));
7369 elsif Nkind (S) = N_Discriminant_Association then
7371 -- syntactically valid in subtype indication.
7373 Error_Msg_N ("invalid index constraint", S);
7374 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7377 -- Subtype_Mark case, no anonymous subtypes to construct
7382 if Is_Entity_Name (S) then
7384 if not Is_Type (Entity (S)) then
7385 Error_Msg_N ("expect subtype mark for index constraint", S);
7387 elsif Base_Type (Entity (S)) /= Base_Type (T) then
7388 Wrong_Type (S, Base_Type (T));
7394 Error_Msg_N ("invalid index constraint", S);
7395 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7401 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
7403 Set_Etype (Def_Id, Base_Type (T));
7405 if Is_Modular_Integer_Type (T) then
7406 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7408 elsif Is_Integer_Type (T) then
7409 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7412 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7413 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7416 Set_Size_Info (Def_Id, (T));
7417 Set_RM_Size (Def_Id, RM_Size (T));
7418 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7420 Set_Scalar_Range (Def_Id, R);
7422 Set_Etype (S, Def_Id);
7423 Set_Discrete_RM_Size (Def_Id);
7424 end Constrain_Index;
7426 -----------------------
7427 -- Constrain_Integer --
7428 -----------------------
7430 procedure Constrain_Integer
7433 Related_Nod : Node_Id)
7435 T : constant Entity_Id := Entity (Subtype_Mark (S));
7436 C : constant Node_Id := Constraint (S);
7439 Set_Scalar_Range_For_Subtype
7440 (Def_Id, Range_Expression (C), T, Related_Nod);
7442 if Is_Modular_Integer_Type (T) then
7443 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7445 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7448 Set_Etype (Def_Id, Base_Type (T));
7449 Set_Size_Info (Def_Id, (T));
7450 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7451 Set_Discrete_RM_Size (Def_Id);
7453 end Constrain_Integer;
7455 ------------------------------
7456 -- Constrain_Ordinary_Fixed --
7457 ------------------------------
7459 procedure Constrain_Ordinary_Fixed
7462 Related_Nod : Node_Id)
7464 T : constant Entity_Id := Entity (Subtype_Mark (S));
7470 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
7471 Set_Etype (Def_Id, Base_Type (T));
7472 Set_Size_Info (Def_Id, (T));
7473 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7474 Set_Small_Value (Def_Id, Small_Value (T));
7476 -- Process the constraint
7478 C := Constraint (S);
7480 -- Delta constraint present
7482 if Nkind (C) = N_Delta_Constraint then
7483 D := Delta_Expression (C);
7484 Analyze_And_Resolve (D, Any_Real);
7485 Check_Delta_Expression (D);
7486 Set_Delta_Value (Def_Id, Expr_Value_R (D));
7488 -- Check that delta value is in range. Obviously we can do this
7489 -- at compile time, but it is strictly a runtime check, and of
7490 -- course there is an ACVC test that checks this!
7492 if Delta_Value (Def_Id) < Delta_Value (T) then
7493 Error_Msg_N ("?delta value is too small", D);
7494 Rais := Make_Raise_Constraint_Error (Sloc (D));
7495 Insert_Action (Declaration_Node (Def_Id), Rais);
7498 C := Range_Constraint (C);
7500 -- No delta constraint present
7503 Set_Delta_Value (Def_Id, Delta_Value (T));
7506 -- Range constraint present
7508 if Nkind (C) = N_Range_Constraint then
7509 Set_Scalar_Range_For_Subtype
7510 (Def_Id, Range_Expression (C), T, Related_Nod);
7512 -- No range constraint present
7515 pragma Assert (No (C));
7516 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7520 Set_Discrete_RM_Size (Def_Id);
7522 -- Unconditionally delay the freeze, since we cannot set size
7523 -- information in all cases correctly until the freeze point.
7525 Set_Has_Delayed_Freeze (Def_Id);
7526 end Constrain_Ordinary_Fixed;
7528 ---------------------------
7529 -- Convert_Scalar_Bounds --
7530 ---------------------------
7532 procedure Convert_Scalar_Bounds
7534 Parent_Type : Entity_Id;
7535 Derived_Type : Entity_Id;
7538 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
7545 Lo := Build_Scalar_Bound
7546 (Type_Low_Bound (Derived_Type),
7547 Parent_Type, Implicit_Base, Loc);
7549 Hi := Build_Scalar_Bound
7550 (Type_High_Bound (Derived_Type),
7551 Parent_Type, Implicit_Base, Loc);
7558 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
7560 Set_Parent (Rng, N);
7561 Set_Scalar_Range (Derived_Type, Rng);
7563 -- Analyze the bounds
7565 Analyze_And_Resolve (Lo, Implicit_Base);
7566 Analyze_And_Resolve (Hi, Implicit_Base);
7568 -- Analyze the range itself, except that we do not analyze it if
7569 -- the bounds are real literals, and we have a fixed-point type.
7570 -- The reason for this is that we delay setting the bounds in this
7571 -- case till we know the final Small and Size values (see circuit
7572 -- in Freeze.Freeze_Fixed_Point_Type for further details).
7574 if Is_Fixed_Point_Type (Parent_Type)
7575 and then Nkind (Lo) = N_Real_Literal
7576 and then Nkind (Hi) = N_Real_Literal
7580 -- Here we do the analysis of the range.
7582 -- Note: we do this manually, since if we do a normal Analyze and
7583 -- Resolve call, there are problems with the conversions used for
7584 -- the derived type range.
7587 Set_Etype (Rng, Implicit_Base);
7588 Set_Analyzed (Rng, True);
7590 end Convert_Scalar_Bounds;
7596 procedure Copy_And_Swap (Privat, Full : Entity_Id) is
7598 -- Initialize new full declaration entity by copying the pertinent
7599 -- fields of the corresponding private declaration entity.
7601 Copy_Private_To_Full (Privat, Full);
7603 -- Swap the two entities. Now Privat is the full type entity and
7604 -- Full is the private one. They will be swapped back at the end
7605 -- of the private part. This swapping ensures that the entity that
7606 -- is visible in the private part is the full declaration.
7608 Exchange_Entities (Privat, Full);
7609 Append_Entity (Full, Scope (Full));
7612 -------------------------------------
7613 -- Copy_Array_Base_Type_Attributes --
7614 -------------------------------------
7616 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
7618 Set_Component_Alignment (T1, Component_Alignment (T2));
7619 Set_Component_Type (T1, Component_Type (T2));
7620 Set_Component_Size (T1, Component_Size (T2));
7621 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
7622 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
7623 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
7624 Set_Has_Task (T1, Has_Task (T2));
7625 Set_Is_Packed (T1, Is_Packed (T2));
7626 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
7627 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
7628 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
7629 end Copy_Array_Base_Type_Attributes;
7631 -----------------------------------
7632 -- Copy_Array_Subtype_Attributes --
7633 -----------------------------------
7635 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
7637 Set_Size_Info (T1, T2);
7639 Set_First_Index (T1, First_Index (T2));
7640 Set_Is_Aliased (T1, Is_Aliased (T2));
7641 Set_Is_Atomic (T1, Is_Atomic (T2));
7642 Set_Is_Volatile (T1, Is_Volatile (T2));
7643 Set_Is_Constrained (T1, Is_Constrained (T2));
7644 Set_Depends_On_Private (T1, Has_Private_Component (T2));
7645 Set_First_Rep_Item (T1, First_Rep_Item (T2));
7646 Set_Convention (T1, Convention (T2));
7647 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
7648 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
7649 end Copy_Array_Subtype_Attributes;
7651 --------------------------
7652 -- Copy_Private_To_Full --
7653 --------------------------
7655 procedure Copy_Private_To_Full (Priv, Full : Entity_Id) is
7657 -- We temporarily set Ekind to a value appropriate for a type to
7658 -- avoid assert failures in Einfo from checking for setting type
7659 -- attributes on something that is not a type. Ekind (Priv) is an
7660 -- appropriate choice, since it allowed the attributes to be set
7661 -- in the first place. This Ekind value will be modified later.
7663 Set_Ekind (Full, Ekind (Priv));
7665 -- Also set Etype temporarily to Any_Type, again, in the absence
7666 -- of errors, it will be properly reset, and if there are errors,
7667 -- then we want a value of Any_Type to remain.
7669 Set_Etype (Full, Any_Type);
7671 -- Now start copying attributes
7673 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
7675 if Has_Discriminants (Full) then
7676 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
7677 Set_Girder_Constraint (Full, Girder_Constraint (Priv));
7680 Set_Homonym (Full, Homonym (Priv));
7681 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
7682 Set_Is_Public (Full, Is_Public (Priv));
7683 Set_Is_Pure (Full, Is_Pure (Priv));
7684 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
7686 Conditional_Delay (Full, Priv);
7688 if Is_Tagged_Type (Full) then
7689 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
7691 if Priv = Base_Type (Priv) then
7692 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
7696 Set_Is_Volatile (Full, Is_Volatile (Priv));
7697 Set_Scope (Full, Scope (Priv));
7698 Set_Next_Entity (Full, Next_Entity (Priv));
7699 Set_First_Entity (Full, First_Entity (Priv));
7700 Set_Last_Entity (Full, Last_Entity (Priv));
7702 -- If access types have been recorded for later handling, keep them
7703 -- in the full view so that they get handled when the full view freeze
7704 -- node is expanded.
7706 if Present (Freeze_Node (Priv))
7707 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
7709 Ensure_Freeze_Node (Full);
7710 Set_Access_Types_To_Process (Freeze_Node (Full),
7711 Access_Types_To_Process (Freeze_Node (Priv)));
7713 end Copy_Private_To_Full;
7715 -----------------------------------
7716 -- Create_Constrained_Components --
7717 -----------------------------------
7719 procedure Create_Constrained_Components
7721 Decl_Node : Node_Id;
7723 Constraints : Elist_Id)
7725 Loc : constant Source_Ptr := Sloc (Subt);
7726 Assoc_List : List_Id := New_List;
7727 Comp_List : Elist_Id := New_Elmt_List;
7728 Discr_Val : Elmt_Id;
7732 Is_Static : Boolean := True;
7733 Parent_Type : constant Entity_Id := Etype (Typ);
7735 procedure Collect_Fixed_Components (Typ : Entity_Id);
7736 -- Collect components of parent type that do not appear in a variant
7739 procedure Create_All_Components;
7740 -- Iterate over Comp_List to create the components of the subtype.
7742 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
7743 -- Creates a new component from Old_Compon, coppying all the fields from
7744 -- it, including its Etype, inserts the new component in the Subt entity
7745 -- chain and returns the new component.
7747 function Is_Variant_Record (T : Entity_Id) return Boolean;
7748 -- If true, and discriminants are static, collect only components from
7749 -- variants selected by discriminant values.
7751 ------------------------------
7752 -- Collect_Fixed_Components --
7753 ------------------------------
7755 procedure Collect_Fixed_Components (Typ : Entity_Id) is
7757 -- Build association list for discriminants, and find components of
7758 -- the variant part selected by the values of the discriminants.
7760 Old_C := First_Discriminant (Typ);
7761 Discr_Val := First_Elmt (Constraints);
7763 while Present (Old_C) loop
7764 Append_To (Assoc_List,
7765 Make_Component_Association (Loc,
7766 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
7767 Expression => New_Copy (Node (Discr_Val))));
7769 Next_Elmt (Discr_Val);
7770 Next_Discriminant (Old_C);
7773 -- The tag, and the possible parent and controller components
7774 -- are unconditionally in the subtype.
7776 if Is_Tagged_Type (Typ)
7777 or else Has_Controlled_Component (Typ)
7779 Old_C := First_Component (Typ);
7781 while Present (Old_C) loop
7782 if Chars ((Old_C)) = Name_uTag
7783 or else Chars ((Old_C)) = Name_uParent
7784 or else Chars ((Old_C)) = Name_uController
7786 Append_Elmt (Old_C, Comp_List);
7789 Next_Component (Old_C);
7792 end Collect_Fixed_Components;
7794 ---------------------------
7795 -- Create_All_Components --
7796 ---------------------------
7798 procedure Create_All_Components is
7802 Comp := First_Elmt (Comp_List);
7804 while Present (Comp) loop
7805 Old_C := Node (Comp);
7806 New_C := Create_Component (Old_C);
7810 Constrain_Component_Type
7811 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7812 Set_Is_Public (New_C, Is_Public (Subt));
7816 end Create_All_Components;
7818 ----------------------
7819 -- Create_Component --
7820 ----------------------
7822 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
7823 New_Compon : Entity_Id := New_Copy (Old_Compon);
7826 -- Set the parent so we have a proper link for freezing etc. This
7827 -- is not a real parent pointer, since of course our parent does
7828 -- not own up to us and reference us, we are an illegitimate
7829 -- child of the original parent!
7831 Set_Parent (New_Compon, Parent (Old_Compon));
7833 -- We do not want this node marked as Comes_From_Source, since
7834 -- otherwise it would get first class status and a separate
7835 -- cross-reference line would be generated. Illegitimate
7836 -- children do not rate such recognition.
7838 Set_Comes_From_Source (New_Compon, False);
7840 -- But it is a real entity, and a birth certificate must be
7841 -- properly registered by entering it into the entity list.
7843 Enter_Name (New_Compon);
7845 end Create_Component;
7847 -----------------------
7848 -- Is_Variant_Record --
7849 -----------------------
7851 function Is_Variant_Record (T : Entity_Id) return Boolean is
7853 return Nkind (Parent (T)) = N_Full_Type_Declaration
7854 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
7855 and then Present (Component_List (Type_Definition (Parent (T))))
7857 Variant_Part (Component_List (Type_Definition (Parent (T)))));
7858 end Is_Variant_Record;
7860 -- Start of processing for Create_Constrained_Components
7863 pragma Assert (Subt /= Base_Type (Subt));
7864 pragma Assert (Typ = Base_Type (Typ));
7866 Set_First_Entity (Subt, Empty);
7867 Set_Last_Entity (Subt, Empty);
7869 -- Check whether constraint is fully static, in which case we can
7870 -- optimize the list of components.
7872 Discr_Val := First_Elmt (Constraints);
7874 while Present (Discr_Val) loop
7876 if not Is_OK_Static_Expression (Node (Discr_Val)) then
7881 Next_Elmt (Discr_Val);
7886 -- Inherit the discriminants of the parent type.
7888 Old_C := First_Discriminant (Typ);
7890 while Present (Old_C) loop
7891 New_C := Create_Component (Old_C);
7892 Set_Is_Public (New_C, Is_Public (Subt));
7893 Next_Discriminant (Old_C);
7897 and then Is_Variant_Record (Typ)
7899 Collect_Fixed_Components (Typ);
7903 Component_List (Type_Definition (Parent (Typ))),
7904 Governed_By => Assoc_List,
7906 Report_Errors => Errors);
7907 pragma Assert (not Errors);
7909 Create_All_Components;
7911 -- If the subtype declaration is created for a tagged type derivation
7912 -- with constraints, we retrieve the record definition of the parent
7913 -- type to select the components of the proper variant.
7916 and then Is_Tagged_Type (Typ)
7917 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
7919 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
7920 and then Is_Variant_Record (Parent_Type)
7922 Collect_Fixed_Components (Typ);
7926 Component_List (Type_Definition (Parent (Parent_Type))),
7927 Governed_By => Assoc_List,
7929 Report_Errors => Errors);
7930 pragma Assert (not Errors);
7932 -- If the tagged derivation has a type extension, collect all the
7933 -- new components therein.
7936 Record_Extension_Part (Type_Definition (Parent (Typ))))
7938 Old_C := First_Component (Typ);
7940 while Present (Old_C) loop
7941 if Original_Record_Component (Old_C) = Old_C
7942 and then Chars (Old_C) /= Name_uTag
7943 and then Chars (Old_C) /= Name_uParent
7944 and then Chars (Old_C) /= Name_uController
7946 Append_Elmt (Old_C, Comp_List);
7949 Next_Component (Old_C);
7953 Create_All_Components;
7956 -- If the discriminants are not static, or if this is a multi-level
7957 -- type extension, we have to include all the components of the
7960 Old_C := First_Component (Typ);
7962 while Present (Old_C) loop
7963 New_C := Create_Component (Old_C);
7967 Constrain_Component_Type
7968 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7969 Set_Is_Public (New_C, Is_Public (Subt));
7971 Next_Component (Old_C);
7976 end Create_Constrained_Components;
7978 ------------------------------------------
7979 -- Decimal_Fixed_Point_Type_Declaration --
7980 ------------------------------------------
7982 procedure Decimal_Fixed_Point_Type_Declaration
7986 Loc : constant Source_Ptr := Sloc (Def);
7987 Digs_Expr : constant Node_Id := Digits_Expression (Def);
7988 Delta_Expr : constant Node_Id := Delta_Expression (Def);
7989 Implicit_Base : Entity_Id;
7995 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
7998 Check_Restriction (No_Fixed_Point, Def);
8000 -- Create implicit base type
8003 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
8004 Set_Etype (Implicit_Base, Implicit_Base);
8006 -- Analyze and process delta expression
8008 Analyze_And_Resolve (Delta_Expr, Universal_Real);
8010 Check_Delta_Expression (Delta_Expr);
8011 Delta_Val := Expr_Value_R (Delta_Expr);
8013 -- Check delta is power of 10, and determine scale value from it
8016 Val : Ureal := Delta_Val;
8019 Scale_Val := Uint_0;
8021 if Val < Ureal_1 then
8022 while Val < Ureal_1 loop
8023 Val := Val * Ureal_10;
8024 Scale_Val := Scale_Val + 1;
8027 if Scale_Val > 18 then
8028 Error_Msg_N ("scale exceeds maximum value of 18", Def);
8029 Scale_Val := UI_From_Int (+18);
8033 while Val > Ureal_1 loop
8034 Val := Val / Ureal_10;
8035 Scale_Val := Scale_Val - 1;
8038 if Scale_Val < -18 then
8039 Error_Msg_N ("scale is less than minimum value of -18", Def);
8040 Scale_Val := UI_From_Int (-18);
8044 if Val /= Ureal_1 then
8045 Error_Msg_N ("delta expression must be a power of 10", Def);
8046 Delta_Val := Ureal_10 ** (-Scale_Val);
8050 -- Set delta, scale and small (small = delta for decimal type)
8052 Set_Delta_Value (Implicit_Base, Delta_Val);
8053 Set_Scale_Value (Implicit_Base, Scale_Val);
8054 Set_Small_Value (Implicit_Base, Delta_Val);
8056 -- Analyze and process digits expression
8058 Analyze_And_Resolve (Digs_Expr, Any_Integer);
8059 Check_Digits_Expression (Digs_Expr);
8060 Digs_Val := Expr_Value (Digs_Expr);
8062 if Digs_Val > 18 then
8063 Digs_Val := UI_From_Int (+18);
8064 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8067 Set_Digits_Value (Implicit_Base, Digs_Val);
8068 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8070 -- Set range of base type from digits value for now. This will be
8071 -- expanded to represent the true underlying base range by Freeze.
8073 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8075 -- Set size to zero for now, size will be set at freeze time. We have
8076 -- to do this for ordinary fixed-point, because the size depends on
8077 -- the specified small, and we might as well do the same for decimal
8080 Init_Size_Align (Implicit_Base);
8082 -- Complete entity for first subtype
8084 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
8085 Set_Etype (T, Implicit_Base);
8086 Set_Size_Info (T, Implicit_Base);
8087 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
8088 Set_Digits_Value (T, Digs_Val);
8089 Set_Delta_Value (T, Delta_Val);
8090 Set_Small_Value (T, Delta_Val);
8091 Set_Scale_Value (T, Scale_Val);
8092 Set_Is_Constrained (T);
8094 -- If there are bounds given in the declaration use them as the
8095 -- bounds of the first named subtype.
8097 if Present (Real_Range_Specification (Def)) then
8099 RRS : constant Node_Id := Real_Range_Specification (Def);
8100 Low : constant Node_Id := Low_Bound (RRS);
8101 High : constant Node_Id := High_Bound (RRS);
8106 Analyze_And_Resolve (Low, Any_Real);
8107 Analyze_And_Resolve (High, Any_Real);
8108 Check_Real_Bound (Low);
8109 Check_Real_Bound (High);
8110 Low_Val := Expr_Value_R (Low);
8111 High_Val := Expr_Value_R (High);
8113 if Low_Val < (-Bound_Val) then
8115 ("range low bound too small for digits value", Low);
8116 Low_Val := -Bound_Val;
8119 if High_Val > Bound_Val then
8121 ("range high bound too large for digits value", High);
8122 High_Val := Bound_Val;
8125 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
8128 -- If no explicit range, use range that corresponds to given
8129 -- digits value. This will end up as the final range for the
8133 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
8136 end Decimal_Fixed_Point_Type_Declaration;
8138 -----------------------
8139 -- Derive_Subprogram --
8140 -----------------------
8142 procedure Derive_Subprogram
8143 (New_Subp : in out Entity_Id;
8144 Parent_Subp : Entity_Id;
8145 Derived_Type : Entity_Id;
8146 Parent_Type : Entity_Id;
8147 Actual_Subp : Entity_Id := Empty)
8150 New_Formal : Entity_Id;
8151 Same_Subt : constant Boolean :=
8152 Is_Scalar_Type (Parent_Type)
8153 and then Subtypes_Statically_Compatible (Parent_Type, Derived_Type);
8155 function Is_Private_Overriding return Boolean;
8156 -- If Subp is a private overriding of a visible operation, the in-
8157 -- herited operation derives from the overridden op (even though
8158 -- its body is the overriding one) and the inherited operation is
8159 -- visible now. See sem_disp to see the details of the handling of
8160 -- the overridden subprogram, which is removed from the list of
8161 -- primitive operations of the type.
8163 procedure Replace_Type (Id, New_Id : Entity_Id);
8164 -- When the type is an anonymous access type, create a new access type
8165 -- designating the derived type.
8167 ---------------------------
8168 -- Is_Private_Overriding --
8169 ---------------------------
8171 function Is_Private_Overriding return Boolean is
8175 Prev := Homonym (Parent_Subp);
8177 -- The visible operation that is overriden is a homonym of
8178 -- the parent subprogram. We scan the homonym chain to find
8179 -- the one whose alias is the subprogram we are deriving.
8181 while Present (Prev) loop
8182 if Is_Dispatching_Operation (Parent_Subp)
8183 and then Present (Prev)
8184 and then Ekind (Prev) = Ekind (Parent_Subp)
8185 and then Alias (Prev) = Parent_Subp
8186 and then Scope (Parent_Subp) = Scope (Prev)
8187 and then not Is_Hidden (Prev)
8192 Prev := Homonym (Prev);
8196 end Is_Private_Overriding;
8202 procedure Replace_Type (Id, New_Id : Entity_Id) is
8203 Acc_Type : Entity_Id;
8207 -- When the type is an anonymous access type, create a new access
8208 -- type designating the derived type. This itype must be elaborated
8209 -- at the point of the derivation, not on subsequent calls that may
8210 -- be out of the proper scope for Gigi, so we insert a reference to
8211 -- it after the derivation.
8213 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
8215 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
8218 if Ekind (Desig_Typ) = E_Record_Type_With_Private
8219 and then Present (Full_View (Desig_Typ))
8220 and then not Is_Private_Type (Parent_Type)
8222 Desig_Typ := Full_View (Desig_Typ);
8225 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
8226 Acc_Type := New_Copy (Etype (Id));
8227 Set_Etype (Acc_Type, Acc_Type);
8228 Set_Scope (Acc_Type, New_Subp);
8230 -- Compute size of anonymous access type.
8232 if Is_Array_Type (Desig_Typ)
8233 and then not Is_Constrained (Desig_Typ)
8235 Init_Size (Acc_Type, 2 * System_Address_Size);
8237 Init_Size (Acc_Type, System_Address_Size);
8240 Init_Alignment (Acc_Type);
8242 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
8244 Set_Etype (New_Id, Acc_Type);
8245 Set_Scope (New_Id, New_Subp);
8247 -- Create a reference to it.
8249 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
8250 Set_Itype (IR, Acc_Type);
8251 Insert_After (Parent (Derived_Type), IR);
8254 Set_Etype (New_Id, Etype (Id));
8257 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
8259 (Ekind (Etype (Id)) = E_Record_Type_With_Private
8260 and then Present (Full_View (Etype (Id)))
8261 and then Base_Type (Full_View (Etype (Id))) =
8262 Base_Type (Parent_Type))
8265 -- Constraint checks on formals are generated during expansion,
8266 -- based on the signature of the original subprogram. The bounds
8267 -- of the derived type are not relevant, and thus we can use
8268 -- the base type for the formals. However, the return type may be
8269 -- used in a context that requires that the proper static bounds
8270 -- be used (a case statement, for example) and for those cases
8271 -- we must use the derived type (first subtype), not its base.
8273 if Etype (Id) = Parent_Type
8276 Set_Etype (New_Id, Derived_Type);
8278 Set_Etype (New_Id, Base_Type (Derived_Type));
8282 Set_Etype (New_Id, Etype (Id));
8286 -- Start of processing for Derive_Subprogram
8290 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
8291 Set_Ekind (New_Subp, Ekind (Parent_Subp));
8293 -- Check whether the inherited subprogram is a private operation that
8294 -- should be inherited but not yet made visible. Such subprograms can
8295 -- become visible at a later point (e.g., the private part of a public
8296 -- child unit) via Declare_Inherited_Private_Subprograms. If the
8297 -- following predicate is true, then this is not such a private
8298 -- operation and the subprogram simply inherits the name of the parent
8299 -- subprogram. Note the special check for the names of controlled
8300 -- operations, which are currently exempted from being inherited with
8301 -- a hidden name because they must be findable for generation of
8302 -- implicit run-time calls.
8304 if not Is_Hidden (Parent_Subp)
8305 or else Is_Internal (Parent_Subp)
8306 or else Is_Private_Overriding
8307 or else Is_Internal_Name (Chars (Parent_Subp))
8308 or else Chars (Parent_Subp) = Name_Initialize
8309 or else Chars (Parent_Subp) = Name_Adjust
8310 or else Chars (Parent_Subp) = Name_Finalize
8312 Set_Chars (New_Subp, Chars (Parent_Subp));
8314 -- If parent is hidden, this can be a regular derivation if the
8315 -- parent is immediately visible in a non-instantiating context,
8316 -- or if we are in the private part of an instance. This test
8317 -- should still be refined ???
8319 -- The test for In_Instance_Not_Visible avoids inheriting the
8320 -- derived operation as a non-visible operation in cases where
8321 -- the parent subprogram might not be visible now, but was
8322 -- visible within the original generic, so it would be wrong
8323 -- to make the inherited subprogram non-visible now. (Not
8324 -- clear if this test is fully correct; are there any cases
8325 -- where we should declare the inherited operation as not
8326 -- visible to avoid it being overridden, e.g., when the
8327 -- parent type is a generic actual with private primitives ???)
8329 -- (they should be treated the same as other private inherited
8330 -- subprograms, but it's not clear how to do this cleanly). ???
8332 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
8333 and then Is_Immediately_Visible (Parent_Subp)
8334 and then not In_Instance)
8335 or else In_Instance_Not_Visible
8337 Set_Chars (New_Subp, Chars (Parent_Subp));
8339 -- The type is inheriting a private operation, so enter
8340 -- it with a special name so it can't be overridden.
8343 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
8346 Set_Parent (New_Subp, Parent (Derived_Type));
8347 Replace_Type (Parent_Subp, New_Subp);
8348 Conditional_Delay (New_Subp, Parent_Subp);
8350 Formal := First_Formal (Parent_Subp);
8351 while Present (Formal) loop
8352 New_Formal := New_Copy (Formal);
8354 -- Normally we do not go copying parents, but in the case of
8355 -- formals, we need to link up to the declaration (which is
8356 -- the parameter specification), and it is fine to link up to
8357 -- the original formal's parameter specification in this case.
8359 Set_Parent (New_Formal, Parent (Formal));
8361 Append_Entity (New_Formal, New_Subp);
8363 Replace_Type (Formal, New_Formal);
8364 Next_Formal (Formal);
8367 -- If this derivation corresponds to a tagged generic actual, then
8368 -- primitive operations rename those of the actual. Otherwise the
8369 -- primitive operations rename those of the parent type.
8371 if No (Actual_Subp) then
8372 Set_Alias (New_Subp, Parent_Subp);
8373 Set_Is_Intrinsic_Subprogram (New_Subp,
8374 Is_Intrinsic_Subprogram (Parent_Subp));
8377 Set_Alias (New_Subp, Actual_Subp);
8380 -- Derived subprograms of a tagged type must inherit the convention
8381 -- of the parent subprogram (a requirement of AI-117). Derived
8382 -- subprograms of untagged types simply get convention Ada by default.
8384 if Is_Tagged_Type (Derived_Type) then
8385 Set_Convention (New_Subp, Convention (Parent_Subp));
8388 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
8389 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
8391 if Ekind (Parent_Subp) = E_Procedure then
8392 Set_Is_Valued_Procedure
8393 (New_Subp, Is_Valued_Procedure (Parent_Subp));
8396 New_Overloaded_Entity (New_Subp, Derived_Type);
8398 -- Check for case of a derived subprogram for the instantiation
8399 -- of a formal derived tagged type, so mark the subprogram as
8400 -- dispatching and inherit the dispatching attributes of the
8401 -- parent subprogram. The derived subprogram is effectively a
8402 -- renaming of the actual subprogram, so it needs to have the
8403 -- same attributes as the actual.
8405 if Present (Actual_Subp)
8406 and then Is_Dispatching_Operation (Parent_Subp)
8408 Set_Is_Dispatching_Operation (New_Subp);
8409 if Present (DTC_Entity (Parent_Subp)) then
8410 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
8411 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
8415 -- Indicate that a derived subprogram does not require a body
8416 -- and that it does not require processing of default expressions.
8418 Set_Has_Completion (New_Subp);
8419 Set_Default_Expressions_Processed (New_Subp);
8421 -- A derived function with a controlling result is abstract.
8422 -- If the Derived_Type is a nonabstract formal generic derived
8423 -- type, then inherited operations are not abstract: check is
8424 -- done at instantiation time. If the derivation is for a generic
8425 -- actual, the function is not abstract unless the actual is.
8427 if Is_Generic_Type (Derived_Type)
8428 and then not Is_Abstract (Derived_Type)
8432 elsif Is_Abstract (Alias (New_Subp))
8433 or else (Is_Tagged_Type (Derived_Type)
8434 and then Etype (New_Subp) = Derived_Type
8435 and then No (Actual_Subp))
8437 Set_Is_Abstract (New_Subp);
8440 if Ekind (New_Subp) = E_Function then
8441 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
8443 end Derive_Subprogram;
8445 ------------------------
8446 -- Derive_Subprograms --
8447 ------------------------
8449 procedure Derive_Subprograms
8450 (Parent_Type : Entity_Id;
8451 Derived_Type : Entity_Id;
8452 Generic_Actual : Entity_Id := Empty)
8454 Op_List : Elist_Id := Collect_Primitive_Operations (Parent_Type);
8455 Act_List : Elist_Id;
8459 New_Subp : Entity_Id := Empty;
8460 Parent_Base : Entity_Id;
8463 if Ekind (Parent_Type) = E_Record_Type_With_Private
8464 and then Has_Discriminants (Parent_Type)
8465 and then Present (Full_View (Parent_Type))
8467 Parent_Base := Full_View (Parent_Type);
8469 Parent_Base := Parent_Type;
8472 Elmt := First_Elmt (Op_List);
8474 if Present (Generic_Actual) then
8475 Act_List := Collect_Primitive_Operations (Generic_Actual);
8476 Act_Elmt := First_Elmt (Act_List);
8478 Act_Elmt := No_Elmt;
8481 -- Literals are derived earlier in the process of building the
8482 -- derived type, and are skipped here.
8484 while Present (Elmt) loop
8485 Subp := Node (Elmt);
8487 if Ekind (Subp) /= E_Enumeration_Literal then
8488 if No (Generic_Actual) then
8490 (New_Subp, Subp, Derived_Type, Parent_Base);
8493 Derive_Subprogram (New_Subp, Subp,
8494 Derived_Type, Parent_Base, Node (Act_Elmt));
8495 Next_Elmt (Act_Elmt);
8501 end Derive_Subprograms;
8503 --------------------------------
8504 -- Derived_Standard_Character --
8505 --------------------------------
8507 procedure Derived_Standard_Character
8509 Parent_Type : Entity_Id;
8510 Derived_Type : Entity_Id)
8512 Loc : constant Source_Ptr := Sloc (N);
8513 Def : constant Node_Id := Type_Definition (N);
8514 Indic : constant Node_Id := Subtype_Indication (Def);
8515 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8516 Implicit_Base : constant Entity_Id :=
8518 (E_Enumeration_Type, N, Derived_Type, 'B');
8525 T := Process_Subtype (Indic, N);
8527 Set_Etype (Implicit_Base, Parent_Base);
8528 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
8529 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
8531 Set_Is_Character_Type (Implicit_Base, True);
8532 Set_Has_Delayed_Freeze (Implicit_Base);
8534 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
8535 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
8537 Set_Scalar_Range (Implicit_Base,
8542 Conditional_Delay (Derived_Type, Parent_Type);
8544 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
8545 Set_Etype (Derived_Type, Implicit_Base);
8546 Set_Size_Info (Derived_Type, Parent_Type);
8548 if Unknown_RM_Size (Derived_Type) then
8549 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8552 Set_Is_Character_Type (Derived_Type, True);
8554 if Nkind (Indic) /= N_Subtype_Indication then
8555 Set_Scalar_Range (Derived_Type, Scalar_Range (Implicit_Base));
8558 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
8560 -- Because the implicit base is used in the conversion of the bounds,
8561 -- we have to freeze it now. This is similar to what is done for
8562 -- numeric types, and it equally suspicious, but otherwise a non-
8563 -- static bound will have a reference to an unfrozen type, which is
8564 -- rejected by Gigi (???).
8566 Freeze_Before (N, Implicit_Base);
8568 end Derived_Standard_Character;
8570 ------------------------------
8571 -- Derived_Type_Declaration --
8572 ------------------------------
8574 procedure Derived_Type_Declaration
8577 Is_Completion : Boolean)
8579 Def : constant Node_Id := Type_Definition (N);
8580 Indic : constant Node_Id := Subtype_Indication (Def);
8581 Extension : constant Node_Id := Record_Extension_Part (Def);
8582 Parent_Type : Entity_Id;
8583 Parent_Scope : Entity_Id;
8587 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
8589 if Parent_Type = Any_Type
8590 or else Etype (Parent_Type) = Any_Type
8591 or else (Is_Class_Wide_Type (Parent_Type)
8592 and then Etype (Parent_Type) = T)
8594 -- If Parent_Type is undefined or illegal, make new type into
8595 -- a subtype of Any_Type, and set a few attributes to prevent
8596 -- cascaded errors. If this is a self-definition, emit error now.
8599 or else T = Etype (Parent_Type)
8601 Error_Msg_N ("type cannot be used in its own definition", Indic);
8604 Set_Ekind (T, Ekind (Parent_Type));
8605 Set_Etype (T, Any_Type);
8606 Set_Scalar_Range (T, Scalar_Range (Any_Type));
8608 if Is_Tagged_Type (T) then
8609 Set_Primitive_Operations (T, New_Elmt_List);
8613 elsif Is_Unchecked_Union (Parent_Type) then
8614 Error_Msg_N ("cannot derive from Unchecked_Union type", N);
8617 -- Only composite types other than array types are allowed to have
8620 if Present (Discriminant_Specifications (N))
8621 and then (Is_Elementary_Type (Parent_Type)
8622 or else Is_Array_Type (Parent_Type))
8623 and then not Error_Posted (N)
8626 ("elementary or array type cannot have discriminants",
8627 Defining_Identifier (First (Discriminant_Specifications (N))));
8628 Set_Has_Discriminants (T, False);
8631 -- In Ada 83, a derived type defined in a package specification cannot
8632 -- be used for further derivation until the end of its visible part.
8633 -- Note that derivation in the private part of the package is allowed.
8636 and then Is_Derived_Type (Parent_Type)
8637 and then In_Visible_Part (Scope (Parent_Type))
8639 if Ada_83 and then Comes_From_Source (Indic) then
8641 ("(Ada 83): premature use of type for derivation", Indic);
8645 -- Check for early use of incomplete or private type
8647 if Ekind (Parent_Type) = E_Void
8648 or else Ekind (Parent_Type) = E_Incomplete_Type
8650 Error_Msg_N ("premature derivation of incomplete type", Indic);
8653 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
8654 and then not Is_Generic_Type (Parent_Type)
8655 and then not Is_Generic_Type (Root_Type (Parent_Type))
8656 and then not Is_Generic_Actual_Type (Parent_Type))
8657 or else Has_Private_Component (Parent_Type)
8659 -- The ancestor type of a formal type can be incomplete, in which
8660 -- case only the operations of the partial view are available in
8661 -- the generic. Subsequent checks may be required when the full
8662 -- view is analyzed, to verify that derivation from a tagged type
8663 -- has an extension.
8665 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
8668 elsif No (Underlying_Type (Parent_Type))
8669 or else Has_Private_Component (Parent_Type)
8672 ("premature derivation of derived or private type", Indic);
8674 -- Flag the type itself as being in error, this prevents some
8675 -- nasty problems with people looking at the malformed type.
8677 Set_Error_Posted (T);
8679 -- Check that within the immediate scope of an untagged partial
8680 -- view it's illegal to derive from the partial view if the
8681 -- full view is tagged. (7.3(7))
8683 -- We verify that the Parent_Type is a partial view by checking
8684 -- that it is not a Full_Type_Declaration (i.e. a private type or
8685 -- private extension declaration), to distinguish a partial view
8686 -- from a derivation from a private type which also appears as
8689 elsif Present (Full_View (Parent_Type))
8690 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
8691 and then not Is_Tagged_Type (Parent_Type)
8692 and then Is_Tagged_Type (Full_View (Parent_Type))
8694 Parent_Scope := Scope (T);
8695 while Present (Parent_Scope)
8696 and then Parent_Scope /= Standard_Standard
8698 if Parent_Scope = Scope (Parent_Type) then
8700 ("premature derivation from type with tagged full view",
8704 Parent_Scope := Scope (Parent_Scope);
8709 -- Check that form of derivation is appropriate
8711 Taggd := Is_Tagged_Type (Parent_Type);
8713 -- Perhaps the parent type should be changed to the class-wide type's
8714 -- specific type in this case to prevent cascading errors ???
8716 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
8717 Error_Msg_N ("parent type must not be a class-wide type", Indic);
8721 if Present (Extension) and then not Taggd then
8723 ("type derived from untagged type cannot have extension", Indic);
8725 elsif No (Extension) and then Taggd then
8726 -- If this is within a private part (or body) of a generic
8727 -- instantiation then the derivation is allowed (the parent
8728 -- type can only appear tagged in this case if it's a generic
8729 -- actual type, since it would otherwise have been rejected
8730 -- in the analysis of the generic template).
8732 if not Is_Generic_Actual_Type (Parent_Type)
8733 or else In_Visible_Part (Scope (Parent_Type))
8736 ("type derived from tagged type must have extension", Indic);
8740 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
8741 end Derived_Type_Declaration;
8743 ----------------------------------
8744 -- Enumeration_Type_Declaration --
8745 ----------------------------------
8747 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
8754 -- Create identifier node representing lower bound
8756 B_Node := New_Node (N_Identifier, Sloc (Def));
8757 L := First (Literals (Def));
8758 Set_Chars (B_Node, Chars (L));
8759 Set_Entity (B_Node, L);
8760 Set_Etype (B_Node, T);
8761 Set_Is_Static_Expression (B_Node, True);
8763 R_Node := New_Node (N_Range, Sloc (Def));
8764 Set_Low_Bound (R_Node, B_Node);
8766 Set_Ekind (T, E_Enumeration_Type);
8767 Set_First_Literal (T, L);
8769 Set_Is_Constrained (T);
8773 -- Loop through literals of enumeration type setting pos and rep values
8774 -- except that if the Ekind is already set, then it means that the
8775 -- literal was already constructed (case of a derived type declaration
8776 -- and we should not disturb the Pos and Rep values.
8778 while Present (L) loop
8779 if Ekind (L) /= E_Enumeration_Literal then
8780 Set_Ekind (L, E_Enumeration_Literal);
8781 Set_Enumeration_Pos (L, Ev);
8782 Set_Enumeration_Rep (L, Ev);
8783 Set_Is_Known_Valid (L, True);
8787 New_Overloaded_Entity (L);
8788 Generate_Definition (L);
8789 Set_Convention (L, Convention_Intrinsic);
8791 if Nkind (L) = N_Defining_Character_Literal then
8792 Set_Is_Character_Type (T, True);
8799 -- Now create a node representing upper bound
8801 B_Node := New_Node (N_Identifier, Sloc (Def));
8802 Set_Chars (B_Node, Chars (Last (Literals (Def))));
8803 Set_Entity (B_Node, Last (Literals (Def)));
8804 Set_Etype (B_Node, T);
8805 Set_Is_Static_Expression (B_Node, True);
8807 Set_High_Bound (R_Node, B_Node);
8808 Set_Scalar_Range (T, R_Node);
8809 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
8812 -- Set Discard_Names if configuration pragma setg, or if there is
8813 -- a parameterless pragma in the current declarative region
8815 if Global_Discard_Names
8816 or else Discard_Names (Scope (T))
8818 Set_Discard_Names (T);
8820 end Enumeration_Type_Declaration;
8822 --------------------------
8823 -- Expand_Others_Choice --
8824 --------------------------
8826 procedure Expand_Others_Choice
8827 (Case_Table : Choice_Table_Type;
8828 Others_Choice : Node_Id;
8829 Choice_Type : Entity_Id)
8832 Choice_List : List_Id := New_List;
8837 Loc : Source_Ptr := Sloc (Others_Choice);
8840 function Build_Choice (Value1, Value2 : Uint) return Node_Id;
8841 -- Builds a node representing the missing choices given by the
8842 -- Value1 and Value2. A N_Range node is built if there is more than
8843 -- one literal value missing. Otherwise a single N_Integer_Literal,
8844 -- N_Identifier or N_Character_Literal is built depending on what
8847 function Lit_Of (Value : Uint) return Node_Id;
8848 -- Returns the Node_Id for the enumeration literal corresponding to the
8849 -- position given by Value within the enumeration type Choice_Type.
8855 function Build_Choice (Value1, Value2 : Uint) return Node_Id is
8860 -- If there is only one choice value missing between Value1 and
8861 -- Value2, build an integer or enumeration literal to represent it.
8863 if (Value2 - Value1) = 0 then
8864 if Is_Integer_Type (Choice_Type) then
8865 Lit_Node := Make_Integer_Literal (Loc, Value1);
8866 Set_Etype (Lit_Node, Choice_Type);
8868 Lit_Node := Lit_Of (Value1);
8871 -- Otherwise is more that one choice value that is missing between
8872 -- Value1 and Value2, therefore build a N_Range node of either
8873 -- integer or enumeration literals.
8876 if Is_Integer_Type (Choice_Type) then
8877 Lo := Make_Integer_Literal (Loc, Value1);
8878 Set_Etype (Lo, Choice_Type);
8879 Hi := Make_Integer_Literal (Loc, Value2);
8880 Set_Etype (Hi, Choice_Type);
8889 Low_Bound => Lit_Of (Value1),
8890 High_Bound => Lit_Of (Value2));
8901 function Lit_Of (Value : Uint) return Node_Id is
8905 -- In the case where the literal is of type Character, there needs
8906 -- to be some special handling since there is no explicit chain
8907 -- of literals to search. Instead, a N_Character_Literal node
8908 -- is created with the appropriate Char_Code and Chars fields.
8910 if Root_Type (Choice_Type) = Standard_Character then
8911 Set_Character_Literal_Name (Char_Code (UI_To_Int (Value)));
8912 Lit := New_Node (N_Character_Literal, Loc);
8913 Set_Chars (Lit, Name_Find);
8914 Set_Char_Literal_Value (Lit, Char_Code (UI_To_Int (Value)));
8915 Set_Etype (Lit, Choice_Type);
8916 Set_Is_Static_Expression (Lit, True);
8919 -- Otherwise, iterate through the literals list of Choice_Type
8920 -- "Value" number of times until the desired literal is reached
8921 -- and then return an occurrence of it.
8924 Lit := First_Literal (Choice_Type);
8925 for J in 1 .. UI_To_Int (Value) loop
8929 return New_Occurrence_Of (Lit, Loc);
8933 -- Start of processing for Expand_Others_Choice
8936 if Case_Table'Length = 0 then
8938 -- Pathological case: only an others case is present.
8939 -- The others case covers the full range of the type.
8941 if Is_Static_Subtype (Choice_Type) then
8942 Choice := New_Occurrence_Of (Choice_Type, Loc);
8944 Choice := New_Occurrence_Of (Base_Type (Choice_Type), Loc);
8947 Set_Others_Discrete_Choices (Others_Choice, New_List (Choice));
8951 -- Establish the bound values for the variant depending upon whether
8952 -- the type of the discriminant name is static or not.
8954 if Is_OK_Static_Subtype (Choice_Type) then
8955 Exp_Lo := Type_Low_Bound (Choice_Type);
8956 Exp_Hi := Type_High_Bound (Choice_Type);
8958 Exp_Lo := Type_Low_Bound (Base_Type (Choice_Type));
8959 Exp_Hi := Type_High_Bound (Base_Type (Choice_Type));
8962 Lo := Expr_Value (Case_Table (Case_Table'First).Lo);
8963 Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8964 Previous_Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8966 -- Build the node for any missing choices that are smaller than any
8967 -- explicit choices given in the variant.
8969 if Expr_Value (Exp_Lo) < Lo then
8970 Append (Build_Choice (Expr_Value (Exp_Lo), Lo - 1), Choice_List);
8973 -- Build the nodes representing any missing choices that lie between
8974 -- the explicit ones given in the variant.
8976 for J in Case_Table'First + 1 .. Case_Table'Last loop
8977 Lo := Expr_Value (Case_Table (J).Lo);
8978 Hi := Expr_Value (Case_Table (J).Hi);
8980 if Lo /= (Previous_Hi + 1) then
8981 Append_To (Choice_List, Build_Choice (Previous_Hi + 1, Lo - 1));
8987 -- Build the node for any missing choices that are greater than any
8988 -- explicit choices given in the variant.
8990 if Expr_Value (Exp_Hi) > Hi then
8991 Append (Build_Choice (Hi + 1, Expr_Value (Exp_Hi)), Choice_List);
8994 Set_Others_Discrete_Choices (Others_Choice, Choice_List);
8995 end Expand_Others_Choice;
8997 ---------------------------------
8998 -- Expand_To_Girder_Constraint --
8999 ---------------------------------
9001 function Expand_To_Girder_Constraint
9003 Constraint : Elist_Id)
9006 Explicitly_Discriminated_Type : Entity_Id;
9007 Expansion : Elist_Id;
9008 Discriminant : Entity_Id;
9010 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
9011 -- Find the nearest type that actually specifies discriminants.
9013 ---------------------------------
9014 -- Type_With_Explicit_Discrims --
9015 ---------------------------------
9017 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
9018 Typ : constant E := Base_Type (Id);
9021 if Ekind (Typ) in Incomplete_Or_Private_Kind then
9022 if Present (Full_View (Typ)) then
9023 return Type_With_Explicit_Discrims (Full_View (Typ));
9027 if Has_Discriminants (Typ) then
9032 if Etype (Typ) = Typ then
9034 elsif Has_Discriminants (Typ) then
9037 return Type_With_Explicit_Discrims (Etype (Typ));
9040 end Type_With_Explicit_Discrims;
9042 -- Start of processing for Expand_To_Girder_Constraint
9046 or else Is_Empty_Elmt_List (Constraint)
9051 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
9053 if No (Explicitly_Discriminated_Type) then
9057 Expansion := New_Elmt_List;
9060 First_Girder_Discriminant (Explicitly_Discriminated_Type);
9062 while Present (Discriminant) loop
9065 Get_Discriminant_Value (
9066 Discriminant, Explicitly_Discriminated_Type, Constraint),
9069 Next_Girder_Discriminant (Discriminant);
9073 end Expand_To_Girder_Constraint;
9075 --------------------
9076 -- Find_Type_Name --
9077 --------------------
9079 function Find_Type_Name (N : Node_Id) return Entity_Id is
9080 Id : constant Entity_Id := Defining_Identifier (N);
9086 -- Find incomplete declaration, if some was given.
9088 Prev := Current_Entity_In_Scope (Id);
9090 if Present (Prev) then
9092 -- Previous declaration exists. Error if not incomplete/private case
9093 -- except if previous declaration is implicit, etc. Enter_Name will
9094 -- emit error if appropriate.
9096 Prev_Par := Parent (Prev);
9098 if not Is_Incomplete_Or_Private_Type (Prev) then
9102 elsif Nkind (N) /= N_Full_Type_Declaration
9103 and then Nkind (N) /= N_Task_Type_Declaration
9104 and then Nkind (N) /= N_Protected_Type_Declaration
9106 -- Completion must be a full type declarations (RM 7.3(4))
9108 Error_Msg_Sloc := Sloc (Prev);
9109 Error_Msg_NE ("invalid completion of }", Id, Prev);
9111 -- Set scope of Id to avoid cascaded errors. Entity is never
9112 -- examined again, except when saving globals in generics.
9114 Set_Scope (Id, Current_Scope);
9117 -- Case of full declaration of incomplete type
9119 elsif Ekind (Prev) = E_Incomplete_Type then
9121 -- Indicate that the incomplete declaration has a matching
9122 -- full declaration. The defining occurrence of the incomplete
9123 -- declaration remains the visible one, and the procedure
9124 -- Get_Full_View dereferences it whenever the type is used.
9126 if Present (Full_View (Prev)) then
9127 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9130 Set_Full_View (Prev, Id);
9131 Append_Entity (Id, Current_Scope);
9132 Set_Is_Public (Id, Is_Public (Prev));
9133 Set_Is_Internal (Id);
9136 -- Case of full declaration of private type
9139 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9140 if Etype (Prev) /= Prev then
9142 -- Prev is a private subtype or a derived type, and needs
9145 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9148 elsif Ekind (Prev) = E_Private_Type
9150 (Nkind (N) = N_Task_Type_Declaration
9151 or else Nkind (N) = N_Protected_Type_Declaration)
9154 ("completion of nonlimited type cannot be limited", N);
9157 elsif Nkind (N) /= N_Full_Type_Declaration
9158 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9160 Error_Msg_N ("full view of private extension must be"
9161 & " an extension", N);
9163 elsif not (Abstract_Present (Parent (Prev)))
9164 and then Abstract_Present (Type_Definition (N))
9166 Error_Msg_N ("full view of non-abstract extension cannot"
9167 & " be abstract", N);
9170 if not In_Private_Part (Current_Scope) then
9172 ("declaration of full view must appear in private part", N);
9175 Copy_And_Swap (Prev, Id);
9176 Set_Full_View (Id, Prev);
9177 Set_Has_Private_Declaration (Prev);
9178 Set_Has_Private_Declaration (Id);
9182 -- Verify that full declaration conforms to incomplete one
9184 if Is_Incomplete_Or_Private_Type (Prev)
9185 and then Present (Discriminant_Specifications (Prev_Par))
9187 if Present (Discriminant_Specifications (N)) then
9188 if Ekind (Prev) = E_Incomplete_Type then
9189 Check_Discriminant_Conformance (N, Prev, Prev);
9191 Check_Discriminant_Conformance (N, Prev, Id);
9196 ("missing discriminants in full type declaration", N);
9198 -- To avoid cascaded errors on subsequent use, share the
9199 -- discriminants of the partial view.
9201 Set_Discriminant_Specifications (N,
9202 Discriminant_Specifications (Prev_Par));
9206 -- A prior untagged private type can have an associated
9207 -- class-wide type due to use of the class attribute,
9208 -- and in this case also the full type is required to
9212 and then (Is_Tagged_Type (Prev)
9213 or else Present (Class_Wide_Type (Prev)))
9215 -- The full declaration is either a tagged record or an
9216 -- extension otherwise this is an error
9218 if Nkind (Type_Definition (N)) = N_Record_Definition then
9219 if not Tagged_Present (Type_Definition (N)) then
9221 ("full declaration of } must be tagged", Prev, Id);
9222 Set_Is_Tagged_Type (Id);
9223 Set_Primitive_Operations (Id, New_Elmt_List);
9226 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
9227 if No (Record_Extension_Part (Type_Definition (N))) then
9229 "full declaration of } must be a record extension",
9231 Set_Is_Tagged_Type (Id);
9232 Set_Primitive_Operations (Id, New_Elmt_List);
9237 ("full declaration of } must be a tagged type", Prev, Id);
9245 -- New type declaration
9252 -------------------------
9253 -- Find_Type_Of_Object --
9254 -------------------------
9256 function Find_Type_Of_Object
9258 Related_Nod : Node_Id)
9261 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
9262 P : constant Node_Id := Parent (Obj_Def);
9267 -- Case of an anonymous array subtype
9269 if Def_Kind = N_Constrained_Array_Definition
9270 or else Def_Kind = N_Unconstrained_Array_Definition
9273 Array_Type_Declaration (T, Obj_Def);
9275 -- Create an explicit subtype whenever possible.
9277 elsif Nkind (P) /= N_Component_Declaration
9278 and then Def_Kind = N_Subtype_Indication
9280 -- Base name of subtype on object name, which will be unique in
9281 -- the current scope.
9283 -- If this is a duplicate declaration, return base type, to avoid
9284 -- generating duplicate anonymous types.
9286 if Error_Posted (P) then
9287 Analyze (Subtype_Mark (Obj_Def));
9288 return Entity (Subtype_Mark (Obj_Def));
9293 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
9295 T := Make_Defining_Identifier (Sloc (P), Nam);
9297 Insert_Action (Obj_Def,
9298 Make_Subtype_Declaration (Sloc (P),
9299 Defining_Identifier => T,
9300 Subtype_Indication => Relocate_Node (Obj_Def)));
9302 -- This subtype may need freezing and it will not be done
9303 -- automatically if the object declaration is not in a
9304 -- declarative part. Since this is an object declaration, the
9305 -- type cannot always be frozen here. Deferred constants do not
9306 -- freeze their type (which often enough will be private).
9308 if Nkind (P) = N_Object_Declaration
9309 and then Constant_Present (P)
9310 and then No (Expression (P))
9315 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
9319 T := Process_Subtype (Obj_Def, Related_Nod);
9323 end Find_Type_Of_Object;
9325 --------------------------------
9326 -- Find_Type_Of_Subtype_Indic --
9327 --------------------------------
9329 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
9333 -- Case of subtype mark with a constraint
9335 if Nkind (S) = N_Subtype_Indication then
9336 Find_Type (Subtype_Mark (S));
9337 Typ := Entity (Subtype_Mark (S));
9340 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
9343 ("incorrect constraint for this kind of type", Constraint (S));
9344 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
9347 -- Otherwise we have a subtype mark without a constraint
9349 elsif Error_Posted (S) then
9350 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
9358 if Typ = Standard_Wide_Character
9359 or else Typ = Standard_Wide_String
9361 Check_Restriction (No_Wide_Characters, S);
9365 end Find_Type_Of_Subtype_Indic;
9367 -------------------------------------
9368 -- Floating_Point_Type_Declaration --
9369 -------------------------------------
9371 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9372 Digs : constant Node_Id := Digits_Expression (Def);
9374 Base_Typ : Entity_Id;
9375 Implicit_Base : Entity_Id;
9378 function Can_Derive_From (E : Entity_Id) return Boolean;
9379 -- Find if given digits value allows derivation from specified type
9381 function Can_Derive_From (E : Entity_Id) return Boolean is
9382 Spec : constant Entity_Id := Real_Range_Specification (Def);
9385 if Digs_Val > Digits_Value (E) then
9389 if Present (Spec) then
9390 if Expr_Value_R (Type_Low_Bound (E)) >
9391 Expr_Value_R (Low_Bound (Spec))
9396 if Expr_Value_R (Type_High_Bound (E)) <
9397 Expr_Value_R (High_Bound (Spec))
9404 end Can_Derive_From;
9406 -- Start of processing for Floating_Point_Type_Declaration
9409 Check_Restriction (No_Floating_Point, Def);
9411 -- Create an implicit base type
9414 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
9416 -- Analyze and verify digits value
9418 Analyze_And_Resolve (Digs, Any_Integer);
9419 Check_Digits_Expression (Digs);
9420 Digs_Val := Expr_Value (Digs);
9422 -- Process possible range spec and find correct type to derive from
9424 Process_Real_Range_Specification (Def);
9426 if Can_Derive_From (Standard_Short_Float) then
9427 Base_Typ := Standard_Short_Float;
9428 elsif Can_Derive_From (Standard_Float) then
9429 Base_Typ := Standard_Float;
9430 elsif Can_Derive_From (Standard_Long_Float) then
9431 Base_Typ := Standard_Long_Float;
9432 elsif Can_Derive_From (Standard_Long_Long_Float) then
9433 Base_Typ := Standard_Long_Long_Float;
9435 -- If we can't derive from any existing type, use long long float
9436 -- and give appropriate message explaining the problem.
9439 Base_Typ := Standard_Long_Long_Float;
9441 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
9442 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
9443 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
9447 ("range too large for any predefined type",
9448 Real_Range_Specification (Def));
9452 -- If there are bounds given in the declaration use them as the bounds
9453 -- of the type, otherwise use the bounds of the predefined base type
9454 -- that was chosen based on the Digits value.
9456 if Present (Real_Range_Specification (Def)) then
9457 Set_Scalar_Range (T, Real_Range_Specification (Def));
9458 Set_Is_Constrained (T);
9460 -- The bounds of this range must be converted to machine numbers
9461 -- in accordance with RM 4.9(38).
9463 Bound := Type_Low_Bound (T);
9465 if Nkind (Bound) = N_Real_Literal then
9466 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9467 Set_Is_Machine_Number (Bound);
9470 Bound := Type_High_Bound (T);
9472 if Nkind (Bound) = N_Real_Literal then
9473 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9474 Set_Is_Machine_Number (Bound);
9478 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
9481 -- Complete definition of implicit base and declared first subtype
9483 Set_Etype (Implicit_Base, Base_Typ);
9485 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
9486 Set_Size_Info (Implicit_Base, (Base_Typ));
9487 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
9488 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
9489 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
9490 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
9492 Set_Ekind (T, E_Floating_Point_Subtype);
9493 Set_Etype (T, Implicit_Base);
9495 Set_Size_Info (T, (Implicit_Base));
9496 Set_RM_Size (T, RM_Size (Implicit_Base));
9497 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
9498 Set_Digits_Value (T, Digs_Val);
9500 end Floating_Point_Type_Declaration;
9502 ----------------------------
9503 -- Get_Discriminant_Value --
9504 ----------------------------
9506 -- This is the situation...
9508 -- There is a non-derived type
9510 -- type T0 (Dx, Dy, Dz...)
9512 -- There are zero or more levels of derivation, with each
9513 -- derivation either purely inheriting the discriminants, or
9514 -- defining its own.
9516 -- type Ti is new Ti-1
9518 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
9520 -- subtype Ti is ...
9522 -- The subtype issue is avoided by the use of
9523 -- Original_Record_Component, and the fact that derived subtypes
9524 -- also derive the constraits.
9526 -- This chain leads back from
9528 -- Typ_For_Constraint
9530 -- Typ_For_Constraint has discriminants, and the value for each
9531 -- discriminant is given by its corresponding Elmt of Constraints.
9533 -- Discriminant is some discriminant in this hierarchy.
9535 -- We need to return its value.
9537 -- We do this by recursively searching each level, and looking for
9538 -- Discriminant. Once we get to the bottom, we start backing up
9539 -- returning the value for it which may in turn be a discriminant
9540 -- further up, so on the backup we continue the substitution.
9542 function Get_Discriminant_Value
9543 (Discriminant : Entity_Id;
9544 Typ_For_Constraint : Entity_Id;
9545 Constraint : Elist_Id)
9550 Discrim_Values : Elist_Id;
9551 Girder_Discrim_Values : Boolean)
9552 return Node_Or_Entity_Id;
9553 -- This is the routine that performs the recursive search of levels
9554 -- as described above.
9558 Discrim_Values : Elist_Id;
9559 Girder_Discrim_Values : Boolean)
9560 return Node_Or_Entity_Id
9564 Result : Node_Or_Entity_Id;
9565 Result_Entity : Node_Id;
9568 -- If inappropriate type, return Error, this happens only in
9569 -- cascaded error situations, and we want to avoid a blow up.
9571 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
9575 -- Look deeper if possible. Use Girder_Constraints only for
9576 -- untagged types. For tagged types use the given constraint.
9577 -- This asymmetry needs explanation???
9579 if not Girder_Discrim_Values
9580 and then Present (Girder_Constraint (Ti))
9581 and then not Is_Tagged_Type (Ti)
9583 Result := Recurse (Ti, Girder_Constraint (Ti), True);
9586 Td : Entity_Id := Etype (Ti);
9590 Result := Discriminant;
9593 if Present (Girder_Constraint (Ti)) then
9595 Recurse (Td, Girder_Constraint (Ti), True);
9598 Recurse (Td, Discrim_Values, Girder_Discrim_Values);
9604 -- Extra underlying places to search, if not found above. For
9605 -- concurrent types, the relevant discriminant appears in the
9606 -- corresponding record. For a type derived from a private type
9607 -- without discriminant, the full view inherits the discriminants
9608 -- of the full view of the parent.
9610 if Result = Discriminant then
9611 if Is_Concurrent_Type (Ti)
9612 and then Present (Corresponding_Record_Type (Ti))
9616 Corresponding_Record_Type (Ti),
9618 Girder_Discrim_Values);
9620 elsif Is_Private_Type (Ti)
9621 and then not Has_Discriminants (Ti)
9622 and then Present (Full_View (Ti))
9623 and then Etype (Full_View (Ti)) /= Ti
9629 Girder_Discrim_Values);
9633 -- If Result is not a (reference to a) discriminant,
9634 -- return it, otherwise set Result_Entity to the discriminant.
9636 if Nkind (Result) = N_Defining_Identifier then
9638 pragma Assert (Result = Discriminant);
9640 Result_Entity := Result;
9643 if not Denotes_Discriminant (Result) then
9647 Result_Entity := Entity (Result);
9650 -- See if this level of derivation actually has discriminants
9651 -- because tagged derivations can add them, hence the lower
9652 -- levels need not have any.
9654 if not Has_Discriminants (Ti) then
9658 -- Scan Ti's discriminants for Result_Entity,
9659 -- and return its corresponding value, if any.
9661 Result_Entity := Original_Record_Component (Result_Entity);
9663 Assoc := First_Elmt (Discrim_Values);
9665 if Girder_Discrim_Values then
9666 Disc := First_Girder_Discriminant (Ti);
9668 Disc := First_Discriminant (Ti);
9671 while Present (Disc) loop
9673 pragma Assert (Present (Assoc));
9675 if Original_Record_Component (Disc) = Result_Entity then
9676 return Node (Assoc);
9681 if Girder_Discrim_Values then
9682 Next_Girder_Discriminant (Disc);
9684 Next_Discriminant (Disc);
9688 -- Could not find it
9693 Result : Node_Or_Entity_Id;
9695 -- Start of processing for Get_Discriminant_Value
9698 -- ??? this routine is a gigantic mess and will be deleted.
9699 -- for the time being just test for the trivial case before calling
9702 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
9704 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9705 E : Elmt_Id := First_Elmt (Constraint);
9707 while Present (D) loop
9708 if Chars (D) = Chars (Discriminant) then
9712 Next_Discriminant (D);
9718 Result := Recurse (Typ_For_Constraint, Constraint, False);
9720 -- ??? hack to disappear when this routine is gone
9722 if Nkind (Result) = N_Defining_Identifier then
9724 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9725 E : Elmt_Id := First_Elmt (Constraint);
9727 while Present (D) loop
9728 if Corresponding_Discriminant (D) = Discriminant then
9732 Next_Discriminant (D);
9738 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
9740 end Get_Discriminant_Value;
9742 --------------------------
9743 -- Has_Range_Constraint --
9744 --------------------------
9746 function Has_Range_Constraint (N : Node_Id) return Boolean is
9747 C : constant Node_Id := Constraint (N);
9750 if Nkind (C) = N_Range_Constraint then
9753 elsif Nkind (C) = N_Digits_Constraint then
9755 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
9757 Present (Range_Constraint (C));
9759 elsif Nkind (C) = N_Delta_Constraint then
9760 return Present (Range_Constraint (C));
9765 end Has_Range_Constraint;
9767 ------------------------
9768 -- Inherit_Components --
9769 ------------------------
9771 function Inherit_Components
9773 Parent_Base : Entity_Id;
9774 Derived_Base : Entity_Id;
9775 Is_Tagged : Boolean;
9776 Inherit_Discr : Boolean;
9780 Assoc_List : Elist_Id := New_Elmt_List;
9782 procedure Inherit_Component
9784 Plain_Discrim : Boolean := False;
9785 Girder_Discrim : Boolean := False);
9786 -- Inherits component Old_C from Parent_Base to the Derived_Base.
9787 -- If Plain_Discrim is True, Old_C is a discriminant.
9788 -- If Girder_Discrim is True, Old_C is a girder discriminant.
9789 -- If they are both false then Old_C is a regular component.
9791 -----------------------
9792 -- Inherit_Component --
9793 -----------------------
9795 procedure Inherit_Component
9797 Plain_Discrim : Boolean := False;
9798 Girder_Discrim : Boolean := False)
9800 New_C : Entity_Id := New_Copy (Old_C);
9802 Discrim : Entity_Id;
9803 Corr_Discrim : Entity_Id;
9806 pragma Assert (not Is_Tagged or else not Girder_Discrim);
9808 Set_Parent (New_C, Parent (Old_C));
9810 -- Regular discriminants and components must be inserted
9811 -- in the scope of the Derived_Base. Do it here.
9813 if not Girder_Discrim then
9817 -- For tagged types the Original_Record_Component must point to
9818 -- whatever this field was pointing to in the parent type. This has
9819 -- already been achieved by the call to New_Copy above.
9821 if not Is_Tagged then
9822 Set_Original_Record_Component (New_C, New_C);
9825 -- If we have inherited a component then see if its Etype contains
9826 -- references to Parent_Base discriminants. In this case, replace
9827 -- these references with the constraints given in Discs. We do not
9828 -- do this for the partial view of private types because this is
9829 -- not needed (only the components of the full view will be used
9830 -- for code generation) and cause problem. We also avoid this
9831 -- transformation in some error situations.
9833 if Ekind (New_C) = E_Component then
9834 if (Is_Private_Type (Derived_Base)
9835 and then not Is_Generic_Type (Derived_Base))
9836 or else (Is_Empty_Elmt_List (Discs)
9837 and then not Expander_Active)
9839 Set_Etype (New_C, Etype (Old_C));
9841 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
9842 Derived_Base, N, Parent_Base, Discs));
9846 -- In derived tagged types it is illegal to reference a non
9847 -- discriminant component in the parent type. To catch this, mark
9848 -- these components with an Ekind of E_Void. This will be reset in
9849 -- Record_Type_Definition after processing the record extension of
9850 -- the derived type.
9852 if Is_Tagged and then Ekind (New_C) = E_Component then
9853 Set_Ekind (New_C, E_Void);
9856 if Plain_Discrim then
9857 Set_Corresponding_Discriminant (New_C, Old_C);
9858 Build_Discriminal (New_C);
9860 -- If we are explicitly inheriting a girder discriminant it will be
9861 -- completely hidden.
9863 elsif Girder_Discrim then
9864 Set_Corresponding_Discriminant (New_C, Empty);
9865 Set_Discriminal (New_C, Empty);
9866 Set_Is_Completely_Hidden (New_C);
9868 -- Set the Original_Record_Component of each discriminant in the
9869 -- derived base to point to the corresponding girder that we just
9872 Discrim := First_Discriminant (Derived_Base);
9873 while Present (Discrim) loop
9874 Corr_Discrim := Corresponding_Discriminant (Discrim);
9876 -- Corr_Discrimm could be missing in an error situation.
9878 if Present (Corr_Discrim)
9879 and then Original_Record_Component (Corr_Discrim) = Old_C
9881 Set_Original_Record_Component (Discrim, New_C);
9884 Next_Discriminant (Discrim);
9887 Append_Entity (New_C, Derived_Base);
9890 if not Is_Tagged then
9891 Append_Elmt (Old_C, Assoc_List);
9892 Append_Elmt (New_C, Assoc_List);
9894 end Inherit_Component;
9896 -- Variables local to Inherit_Components.
9898 Loc : constant Source_Ptr := Sloc (N);
9900 Parent_Discrim : Entity_Id;
9901 Girder_Discrim : Entity_Id;
9904 Component : Entity_Id;
9906 -- Start of processing for Inherit_Components
9909 if not Is_Tagged then
9910 Append_Elmt (Parent_Base, Assoc_List);
9911 Append_Elmt (Derived_Base, Assoc_List);
9914 -- Inherit parent discriminants if needed.
9916 if Inherit_Discr then
9917 Parent_Discrim := First_Discriminant (Parent_Base);
9918 while Present (Parent_Discrim) loop
9919 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
9920 Next_Discriminant (Parent_Discrim);
9924 -- Create explicit girder discrims for untagged types when necessary.
9926 if not Has_Unknown_Discriminants (Derived_Base)
9927 and then Has_Discriminants (Parent_Base)
9928 and then not Is_Tagged
9931 or else First_Discriminant (Parent_Base) /=
9932 First_Girder_Discriminant (Parent_Base))
9934 Girder_Discrim := First_Girder_Discriminant (Parent_Base);
9935 while Present (Girder_Discrim) loop
9936 Inherit_Component (Girder_Discrim, Girder_Discrim => True);
9937 Next_Girder_Discriminant (Girder_Discrim);
9941 -- See if we can apply the second transformation for derived types, as
9942 -- explained in point 6. in the comments above Build_Derived_Record_Type
9943 -- This is achieved by appending Derived_Base discriminants into
9944 -- Discs, which has the side effect of returning a non empty Discs
9945 -- list to the caller of Inherit_Components, which is what we want.
9948 and then Is_Empty_Elmt_List (Discs)
9949 and then (not Is_Private_Type (Derived_Base)
9950 or Is_Generic_Type (Derived_Base))
9952 D := First_Discriminant (Derived_Base);
9953 while Present (D) loop
9954 Append_Elmt (New_Reference_To (D, Loc), Discs);
9955 Next_Discriminant (D);
9959 -- Finally, inherit non-discriminant components unless they are not
9960 -- visible because defined or inherited from the full view of the
9961 -- parent. Don't inherit the _parent field of the parent type.
9963 Component := First_Entity (Parent_Base);
9964 while Present (Component) loop
9965 if Ekind (Component) /= E_Component
9966 or else Chars (Component) = Name_uParent
9970 -- If the derived type is within the parent type's declarative
9971 -- region, then the components can still be inherited even though
9972 -- they aren't visible at this point. This can occur for cases
9973 -- such as within public child units where the components must
9974 -- become visible upon entering the child unit's private part.
9976 elsif not Is_Visible_Component (Component)
9977 and then not In_Open_Scopes (Scope (Parent_Base))
9981 elsif Ekind (Derived_Base) = E_Private_Type
9982 or else Ekind (Derived_Base) = E_Limited_Private_Type
9987 Inherit_Component (Component);
9990 Next_Entity (Component);
9993 -- For tagged derived types, inherited discriminants cannot be used in
9994 -- component declarations of the record extension part. To achieve this
9995 -- we mark the inherited discriminants as not visible.
9997 if Is_Tagged and then Inherit_Discr then
9998 D := First_Discriminant (Derived_Base);
9999 while Present (D) loop
10000 Set_Is_Immediately_Visible (D, False);
10001 Next_Discriminant (D);
10006 end Inherit_Components;
10008 ------------------------------
10009 -- Is_Valid_Constraint_Kind --
10010 ------------------------------
10012 function Is_Valid_Constraint_Kind
10013 (T_Kind : Type_Kind;
10014 Constraint_Kind : Node_Kind)
10020 when Enumeration_Kind |
10022 return Constraint_Kind = N_Range_Constraint;
10024 when Decimal_Fixed_Point_Kind =>
10026 Constraint_Kind = N_Digits_Constraint
10028 Constraint_Kind = N_Range_Constraint;
10030 when Ordinary_Fixed_Point_Kind =>
10032 Constraint_Kind = N_Delta_Constraint
10034 Constraint_Kind = N_Range_Constraint;
10038 Constraint_Kind = N_Digits_Constraint
10040 Constraint_Kind = N_Range_Constraint;
10047 E_Incomplete_Type |
10050 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
10053 return True; -- Error will be detected later.
10056 end Is_Valid_Constraint_Kind;
10058 --------------------------
10059 -- Is_Visible_Component --
10060 --------------------------
10062 function Is_Visible_Component (C : Entity_Id) return Boolean is
10063 Original_Comp : constant Entity_Id := Original_Record_Component (C);
10064 Original_Scope : Entity_Id;
10067 if No (Original_Comp) then
10069 -- Premature usage, or previous error
10074 Original_Scope := Scope (Original_Comp);
10077 -- This test only concern tagged types
10079 if not Is_Tagged_Type (Original_Scope) then
10082 -- If it is _Parent or _Tag, there is no visiblity issue
10084 elsif not Comes_From_Source (Original_Comp) then
10087 -- If we are in the body of an instantiation, the component is
10088 -- visible even when the parent type (possibly defined in an
10089 -- enclosing unit or in a parent unit) might not.
10091 elsif In_Instance_Body then
10094 -- Discriminants are always visible.
10096 elsif Ekind (Original_Comp) = E_Discriminant
10097 and then not Has_Unknown_Discriminants (Original_Scope)
10101 -- If the component has been declared in an ancestor which is
10102 -- currently a private type, then it is not visible. The same
10103 -- applies if the component's containing type is not in an
10104 -- open scope and the original component's enclosing type
10105 -- is a visible full type of a private type (which can occur
10106 -- in cases where an attempt is being made to reference a
10107 -- component in a sibling package that is inherited from
10108 -- a visible component of a type in an ancestor package;
10109 -- the component in the sibling package should not be
10110 -- visible even though the component it inherited from
10111 -- is visible). This does not apply however in the case
10112 -- where the scope of the type is a private child unit.
10113 -- The latter suppression of visibility is needed for cases
10114 -- that are tested in B730006.
10116 elsif (Ekind (Original_Comp) /= E_Discriminant
10117 or else Has_Unknown_Discriminants (Original_Scope))
10119 (Is_Private_Type (Original_Scope)
10121 (not Is_Private_Descendant (Scope (Base_Type (Scope (C))))
10122 and then not In_Open_Scopes (Scope (Base_Type (Scope (C))))
10123 and then Has_Private_Declaration (Original_Scope)))
10127 -- There is another weird way in which a component may be invisible
10128 -- when the private and the full view are not derived from the same
10129 -- ancestor. Here is an example :
10131 -- type A1 is tagged record F1 : integer; end record;
10132 -- type A2 is new A1 with record F2 : integer; end record;
10133 -- type T is new A1 with private;
10135 -- type T is new A2 with private;
10137 -- In this case, the full view of T inherits F1 and F2 but the
10138 -- private view inherits only F1
10142 Ancestor : Entity_Id := Scope (C);
10146 if Ancestor = Original_Scope then
10148 elsif Ancestor = Etype (Ancestor) then
10152 Ancestor := Etype (Ancestor);
10158 end Is_Visible_Component;
10160 --------------------------
10161 -- Make_Class_Wide_Type --
10162 --------------------------
10164 procedure Make_Class_Wide_Type (T : Entity_Id) is
10165 CW_Type : Entity_Id;
10167 Next_E : Entity_Id;
10170 -- The class wide type can have been defined by the partial view in
10171 -- which case everything is already done
10173 if Present (Class_Wide_Type (T)) then
10178 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
10180 -- Inherit root type characteristics
10182 CW_Name := Chars (CW_Type);
10183 Next_E := Next_Entity (CW_Type);
10184 Copy_Node (T, CW_Type);
10185 Set_Comes_From_Source (CW_Type, False);
10186 Set_Chars (CW_Type, CW_Name);
10187 Set_Parent (CW_Type, Parent (T));
10188 Set_Next_Entity (CW_Type, Next_E);
10189 Set_Has_Delayed_Freeze (CW_Type);
10191 -- Customize the class-wide type: It has no prim. op., it cannot be
10192 -- abstract and its Etype points back to the root type
10194 Set_Ekind (CW_Type, E_Class_Wide_Type);
10195 Set_Is_Tagged_Type (CW_Type, True);
10196 Set_Primitive_Operations (CW_Type, New_Elmt_List);
10197 Set_Is_Abstract (CW_Type, False);
10198 Set_Etype (CW_Type, T);
10199 Set_Is_Constrained (CW_Type, False);
10200 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
10201 Init_Size_Align (CW_Type);
10203 -- If this is the class_wide type of a constrained subtype, it does
10204 -- not have discriminants.
10206 Set_Has_Discriminants (CW_Type,
10207 Has_Discriminants (T) and then not Is_Constrained (T));
10209 Set_Has_Unknown_Discriminants (CW_Type, True);
10210 Set_Class_Wide_Type (T, CW_Type);
10211 Set_Equivalent_Type (CW_Type, Empty);
10213 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
10215 Set_Class_Wide_Type (CW_Type, CW_Type);
10217 end Make_Class_Wide_Type;
10223 procedure Make_Index
10225 Related_Nod : Node_Id;
10226 Related_Id : Entity_Id := Empty;
10227 Suffix_Index : Nat := 1)
10231 Def_Id : Entity_Id := Empty;
10232 Found : Boolean := False;
10235 -- For a discrete range used in a constrained array definition and
10236 -- defined by a range, an implicit conversion to the predefined type
10237 -- INTEGER is assumed if each bound is either a numeric literal, a named
10238 -- number, or an attribute, and the type of both bounds (prior to the
10239 -- implicit conversion) is the type universal_integer. Otherwise, both
10240 -- bounds must be of the same discrete type, other than universal
10241 -- integer; this type must be determinable independently of the
10242 -- context, but using the fact that the type must be discrete and that
10243 -- both bounds must have the same type.
10245 -- Character literals also have a universal type in the absence of
10246 -- of additional context, and are resolved to Standard_Character.
10248 if Nkind (I) = N_Range then
10250 -- The index is given by a range constraint. The bounds are known
10251 -- to be of a consistent type.
10253 if not Is_Overloaded (I) then
10256 -- If the bounds are universal, choose the specific predefined
10259 if T = Universal_Integer then
10260 T := Standard_Integer;
10262 elsif T = Any_Character then
10266 ("ambiguous character literals (could be Wide_Character)",
10270 T := Standard_Character;
10277 Ind : Interp_Index;
10281 Get_First_Interp (I, Ind, It);
10283 while Present (It.Typ) loop
10284 if Is_Discrete_Type (It.Typ) then
10287 and then not Covers (It.Typ, T)
10288 and then not Covers (T, It.Typ)
10290 Error_Msg_N ("ambiguous bounds in discrete range", I);
10298 Get_Next_Interp (Ind, It);
10301 if T = Any_Type then
10302 Error_Msg_N ("discrete type required for range", I);
10303 Set_Etype (I, Any_Type);
10306 elsif T = Universal_Integer then
10307 T := Standard_Integer;
10312 if not Is_Discrete_Type (T) then
10313 Error_Msg_N ("discrete type required for range", I);
10314 Set_Etype (I, Any_Type);
10319 Process_Range_Expr_In_Decl (R, T, Related_Nod);
10321 elsif Nkind (I) = N_Subtype_Indication then
10323 -- The index is given by a subtype with a range constraint.
10325 T := Base_Type (Entity (Subtype_Mark (I)));
10327 if not Is_Discrete_Type (T) then
10328 Error_Msg_N ("discrete type required for range", I);
10329 Set_Etype (I, Any_Type);
10333 R := Range_Expression (Constraint (I));
10336 Process_Range_Expr_In_Decl (R,
10337 Entity (Subtype_Mark (I)), Related_Nod);
10339 elsif Nkind (I) = N_Attribute_Reference then
10341 -- The parser guarantees that the attribute is a RANGE attribute
10343 Analyze_And_Resolve (I);
10347 -- If none of the above, must be a subtype. We convert this to a
10348 -- range attribute reference because in the case of declared first
10349 -- named subtypes, the types in the range reference can be different
10350 -- from the type of the entity. A range attribute normalizes the
10351 -- reference and obtains the correct types for the bounds.
10353 -- This transformation is in the nature of an expansion, is only
10354 -- done if expansion is active. In particular, it is not done on
10355 -- formal generic types, because we need to retain the name of the
10356 -- original index for instantiation purposes.
10359 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
10360 Error_Msg_N ("invalid subtype mark in discrete range ", I);
10361 Set_Etype (I, Any_Integer);
10364 -- The type mark may be that of an incomplete type. It is only
10365 -- now that we can get the full view, previous analysis does
10366 -- not look specifically for a type mark.
10368 Set_Entity (I, Get_Full_View (Entity (I)));
10369 Set_Etype (I, Entity (I));
10370 Def_Id := Entity (I);
10372 if not Is_Discrete_Type (Def_Id) then
10373 Error_Msg_N ("discrete type required for index", I);
10374 Set_Etype (I, Any_Type);
10379 if Expander_Active then
10381 Make_Attribute_Reference (Sloc (I),
10382 Attribute_Name => Name_Range,
10383 Prefix => Relocate_Node (I)));
10385 -- The original was a subtype mark that does not freeze. This
10386 -- means that the rewritten version must not freeze either.
10388 Set_Must_Not_Freeze (I);
10389 Set_Must_Not_Freeze (Prefix (I));
10391 -- Is order critical??? if so, document why, if not
10392 -- use Analyze_And_Resolve
10400 -- Type is legal, nothing else to construct.
10405 if not Is_Discrete_Type (T) then
10406 Error_Msg_N ("discrete type required for range", I);
10407 Set_Etype (I, Any_Type);
10410 elsif T = Any_Type then
10411 Set_Etype (I, Any_Type);
10415 -- We will now create the appropriate Itype to describe the
10416 -- range, but first a check. If we originally had a subtype,
10417 -- then we just label the range with this subtype. Not only
10418 -- is there no need to construct a new subtype, but it is wrong
10419 -- to do so for two reasons:
10421 -- 1. A legality concern, if we have a subtype, it must not
10422 -- freeze, and the Itype would cause freezing incorrectly
10424 -- 2. An efficiency concern, if we created an Itype, it would
10425 -- not be recognized as the same type for the purposes of
10426 -- eliminating checks in some circumstances.
10428 -- We signal this case by setting the subtype entity in Def_Id.
10430 -- It would be nice to also do this optimization for the cases
10431 -- of X'Range and also the explicit range X'First .. X'Last,
10432 -- but that is not done yet (it is just an efficiency concern) ???
10434 if No (Def_Id) then
10437 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
10438 Set_Etype (Def_Id, Base_Type (T));
10440 if Is_Signed_Integer_Type (T) then
10441 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
10443 elsif Is_Modular_Integer_Type (T) then
10444 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
10447 Set_Ekind (Def_Id, E_Enumeration_Subtype);
10448 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
10451 Set_Size_Info (Def_Id, (T));
10452 Set_RM_Size (Def_Id, RM_Size (T));
10453 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10455 Set_Scalar_Range (Def_Id, R);
10456 Conditional_Delay (Def_Id, T);
10458 -- In the subtype indication case, if the immediate parent of the
10459 -- new subtype is non-static, then the subtype we create is non-
10460 -- static, even if its bounds are static.
10462 if Nkind (I) = N_Subtype_Indication
10463 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
10465 Set_Is_Non_Static_Subtype (Def_Id);
10469 -- Final step is to label the index with this constructed type
10471 Set_Etype (I, Def_Id);
10474 ------------------------------
10475 -- Modular_Type_Declaration --
10476 ------------------------------
10478 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10479 Mod_Expr : constant Node_Id := Expression (Def);
10482 procedure Set_Modular_Size (Bits : Int);
10483 -- Sets RM_Size to Bits, and Esize to normal word size above this
10485 procedure Set_Modular_Size (Bits : Int) is
10487 Set_RM_Size (T, UI_From_Int (Bits));
10492 elsif Bits <= 16 then
10493 Init_Esize (T, 16);
10495 elsif Bits <= 32 then
10496 Init_Esize (T, 32);
10499 Init_Esize (T, System_Max_Binary_Modulus_Power);
10501 end Set_Modular_Size;
10503 -- Start of processing for Modular_Type_Declaration
10506 Analyze_And_Resolve (Mod_Expr, Any_Integer);
10508 Set_Ekind (T, E_Modular_Integer_Type);
10509 Init_Alignment (T);
10510 Set_Is_Constrained (T);
10512 if not Is_OK_Static_Expression (Mod_Expr) then
10514 ("non-static expression used for modular type bound", Mod_Expr);
10515 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10517 M_Val := Expr_Value (Mod_Expr);
10521 Error_Msg_N ("modulus value must be positive", Mod_Expr);
10522 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10525 Set_Modulus (T, M_Val);
10527 -- Create bounds for the modular type based on the modulus given in
10528 -- the type declaration and then analyze and resolve those bounds.
10530 Set_Scalar_Range (T,
10531 Make_Range (Sloc (Mod_Expr),
10533 Make_Integer_Literal (Sloc (Mod_Expr), 0),
10535 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
10537 -- Properly analyze the literals for the range. We do this manually
10538 -- because we can't go calling Resolve, since we are resolving these
10539 -- bounds with the type, and this type is certainly not complete yet!
10541 Set_Etype (Low_Bound (Scalar_Range (T)), T);
10542 Set_Etype (High_Bound (Scalar_Range (T)), T);
10543 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
10544 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
10546 -- Loop through powers of two to find number of bits required
10548 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
10552 if M_Val = 2 ** Bits then
10553 Set_Modular_Size (Bits);
10558 elsif M_Val < 2 ** Bits then
10559 Set_Non_Binary_Modulus (T);
10561 if Bits > System_Max_Nonbinary_Modulus_Power then
10562 Error_Msg_Uint_1 :=
10563 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
10565 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
10566 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10570 -- In the non-binary case, set size as per RM 13.3(55).
10572 Set_Modular_Size (Bits);
10579 -- If we fall through, then the size exceed System.Max_Binary_Modulus
10580 -- so we just signal an error and set the maximum size.
10582 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
10583 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
10585 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10586 Init_Alignment (T);
10588 end Modular_Type_Declaration;
10590 -------------------------
10591 -- New_Binary_Operator --
10592 -------------------------
10594 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id) is
10595 Loc : constant Source_Ptr := Sloc (Typ);
10598 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
10599 -- Create abbreviated declaration for the formal of a predefined
10600 -- Operator 'Op' of type 'Typ'
10602 --------------------
10603 -- Make_Op_Formal --
10604 --------------------
10606 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
10607 Formal : Entity_Id;
10610 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
10611 Set_Etype (Formal, Typ);
10612 Set_Mechanism (Formal, Default_Mechanism);
10614 end Make_Op_Formal;
10616 -- Start of processing for New_Binary_Operator
10619 Op := Make_Defining_Operator_Symbol (Loc, Op_Name);
10621 Set_Ekind (Op, E_Operator);
10622 Set_Scope (Op, Current_Scope);
10623 Set_Etype (Op, Typ);
10624 Set_Homonym (Op, Get_Name_Entity_Id (Op_Name));
10625 Set_Is_Immediately_Visible (Op);
10626 Set_Is_Intrinsic_Subprogram (Op);
10627 Set_Has_Completion (Op);
10628 Append_Entity (Op, Current_Scope);
10630 Set_Name_Entity_Id (Op_Name, Op);
10632 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10633 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10635 end New_Binary_Operator;
10637 -------------------------------------------
10638 -- Ordinary_Fixed_Point_Type_Declaration --
10639 -------------------------------------------
10641 procedure Ordinary_Fixed_Point_Type_Declaration
10645 Loc : constant Source_Ptr := Sloc (Def);
10646 Delta_Expr : constant Node_Id := Delta_Expression (Def);
10647 RRS : constant Node_Id := Real_Range_Specification (Def);
10648 Implicit_Base : Entity_Id;
10655 Check_Restriction (No_Fixed_Point, Def);
10657 -- Create implicit base type
10660 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
10661 Set_Etype (Implicit_Base, Implicit_Base);
10663 -- Analyze and process delta expression
10665 Analyze_And_Resolve (Delta_Expr, Any_Real);
10667 Check_Delta_Expression (Delta_Expr);
10668 Delta_Val := Expr_Value_R (Delta_Expr);
10670 Set_Delta_Value (Implicit_Base, Delta_Val);
10672 -- Compute default small from given delta, which is the largest
10673 -- power of two that does not exceed the given delta value.
10676 Tmp : Ureal := Ureal_1;
10680 if Delta_Val < Ureal_1 then
10681 while Delta_Val < Tmp loop
10682 Tmp := Tmp / Ureal_2;
10683 Scale := Scale + 1;
10688 Tmp := Tmp * Ureal_2;
10689 exit when Tmp > Delta_Val;
10690 Scale := Scale - 1;
10694 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
10697 Set_Small_Value (Implicit_Base, Small_Val);
10699 -- If no range was given, set a dummy range
10701 if RRS <= Empty_Or_Error then
10702 Low_Val := -Small_Val;
10703 High_Val := Small_Val;
10705 -- Otherwise analyze and process given range
10709 Low : constant Node_Id := Low_Bound (RRS);
10710 High : constant Node_Id := High_Bound (RRS);
10713 Analyze_And_Resolve (Low, Any_Real);
10714 Analyze_And_Resolve (High, Any_Real);
10715 Check_Real_Bound (Low);
10716 Check_Real_Bound (High);
10718 -- Obtain and set the range
10720 Low_Val := Expr_Value_R (Low);
10721 High_Val := Expr_Value_R (High);
10723 if Low_Val > High_Val then
10724 Error_Msg_NE ("?fixed point type& has null range", Def, T);
10729 -- The range for both the implicit base and the declared first
10730 -- subtype cannot be set yet, so we use the special routine
10731 -- Set_Fixed_Range to set a temporary range in place. Note that
10732 -- the bounds of the base type will be widened to be symmetrical
10733 -- and to fill the available bits when the type is frozen.
10735 -- We could do this with all discrete types, and probably should, but
10736 -- we absolutely have to do it for fixed-point, since the end-points
10737 -- of the range and the size are determined by the small value, which
10738 -- could be reset before the freeze point.
10740 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
10741 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
10743 Init_Size_Align (Implicit_Base);
10745 -- Complete definition of first subtype
10747 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
10748 Set_Etype (T, Implicit_Base);
10749 Init_Size_Align (T);
10750 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
10751 Set_Small_Value (T, Small_Val);
10752 Set_Delta_Value (T, Delta_Val);
10753 Set_Is_Constrained (T);
10755 end Ordinary_Fixed_Point_Type_Declaration;
10757 ----------------------------------------
10758 -- Prepare_Private_Subtype_Completion --
10759 ----------------------------------------
10761 procedure Prepare_Private_Subtype_Completion
10763 Related_Nod : Node_Id)
10765 Id_B : constant Entity_Id := Base_Type (Id);
10766 Full_B : constant Entity_Id := Full_View (Id_B);
10770 if Present (Full_B) then
10772 -- The Base_Type is already completed, we can complete the
10773 -- subtype now. We have to create a new entity with the same name,
10774 -- Thus we can't use Create_Itype.
10775 -- This is messy, should be fixed ???
10777 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
10778 Set_Is_Itype (Full);
10779 Set_Associated_Node_For_Itype (Full, Related_Nod);
10780 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
10783 -- The parent subtype may be private, but the base might not, in some
10784 -- nested instances. In that case, the subtype does not need to be
10785 -- exchanged. It would still be nice to make private subtypes and their
10786 -- bases consistent at all times ???
10788 if Is_Private_Type (Id_B) then
10789 Append_Elmt (Id, Private_Dependents (Id_B));
10792 end Prepare_Private_Subtype_Completion;
10794 ---------------------------
10795 -- Process_Discriminants --
10796 ---------------------------
10798 procedure Process_Discriminants (N : Node_Id) is
10801 Discr_Number : Uint;
10802 Discr_Type : Entity_Id;
10803 Default_Present : Boolean := False;
10804 Default_Not_Present : Boolean := False;
10805 Elist : Elist_Id := New_Elmt_List;
10808 -- A composite type other than an array type can have discriminants.
10809 -- Discriminants of non-limited types must have a discrete type.
10810 -- On entry, the current scope is the composite type.
10812 -- The discriminants are initially entered into the scope of the type
10813 -- via Enter_Name with the default Ekind of E_Void to prevent premature
10814 -- use, as explained at the end of this procedure.
10816 Discr := First (Discriminant_Specifications (N));
10817 while Present (Discr) loop
10818 Enter_Name (Defining_Identifier (Discr));
10820 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
10821 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
10824 Find_Type (Discriminant_Type (Discr));
10825 Discr_Type := Etype (Discriminant_Type (Discr));
10827 if Error_Posted (Discriminant_Type (Discr)) then
10828 Discr_Type := Any_Type;
10832 if Is_Access_Type (Discr_Type) then
10833 Check_Access_Discriminant_Requires_Limited
10834 (Discr, Discriminant_Type (Discr));
10836 if Ada_83 and then Comes_From_Source (Discr) then
10838 ("(Ada 83) access discriminant not allowed", Discr);
10841 elsif not Is_Discrete_Type (Discr_Type) then
10842 Error_Msg_N ("discriminants must have a discrete or access type",
10843 Discriminant_Type (Discr));
10846 Set_Etype (Defining_Identifier (Discr), Discr_Type);
10848 -- If a discriminant specification includes the assignment compound
10849 -- delimiter followed by an expression, the expression is the default
10850 -- expression of the discriminant; the default expression must be of
10851 -- the type of the discriminant. (RM 3.7.1) Since this expression is
10852 -- a default expression, we do the special preanalysis, since this
10853 -- expression does not freeze (see "Handling of Default Expressions"
10854 -- in spec of package Sem).
10856 if Present (Expression (Discr)) then
10857 Analyze_Default_Expression (Expression (Discr), Discr_Type);
10859 if Nkind (N) = N_Formal_Type_Declaration then
10861 ("discriminant defaults not allowed for formal type",
10862 Expression (Discr));
10864 elsif Is_Tagged_Type (Current_Scope) then
10866 ("discriminants of tagged type cannot have defaults",
10867 Expression (Discr));
10870 Default_Present := True;
10871 Append_Elmt (Expression (Discr), Elist);
10873 -- Tag the defining identifiers for the discriminants with
10874 -- their corresponding default expressions from the tree.
10876 Set_Discriminant_Default_Value
10877 (Defining_Identifier (Discr), Expression (Discr));
10881 Default_Not_Present := True;
10887 -- An element list consisting of the default expressions of the
10888 -- discriminants is constructed in the above loop and used to set
10889 -- the Discriminant_Constraint attribute for the type. If an object
10890 -- is declared of this (record or task) type without any explicit
10891 -- discriminant constraint given, this element list will form the
10892 -- actual parameters for the corresponding initialization procedure
10895 Set_Discriminant_Constraint (Current_Scope, Elist);
10896 Set_Girder_Constraint (Current_Scope, No_Elist);
10898 -- Default expressions must be provided either for all or for none
10899 -- of the discriminants of a discriminant part. (RM 3.7.1)
10901 if Default_Present and then Default_Not_Present then
10903 ("incomplete specification of defaults for discriminants", N);
10906 -- The use of the name of a discriminant is not allowed in default
10907 -- expressions of a discriminant part if the specification of the
10908 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
10910 -- To detect this, the discriminant names are entered initially with an
10911 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
10912 -- attempt to use a void entity (for example in an expression that is
10913 -- type-checked) produces the error message: premature usage. Now after
10914 -- completing the semantic analysis of the discriminant part, we can set
10915 -- the Ekind of all the discriminants appropriately.
10917 Discr := First (Discriminant_Specifications (N));
10918 Discr_Number := Uint_1;
10920 while Present (Discr) loop
10921 Id := Defining_Identifier (Discr);
10922 Set_Ekind (Id, E_Discriminant);
10923 Init_Component_Location (Id);
10925 Set_Discriminant_Number (Id, Discr_Number);
10927 -- Make sure this is always set, even in illegal programs
10929 Set_Corresponding_Discriminant (Id, Empty);
10931 -- Initialize the Original_Record_Component to the entity itself.
10932 -- Inherit_Components will propagate the right value to
10933 -- discriminants in derived record types.
10935 Set_Original_Record_Component (Id, Id);
10937 -- Create the discriminal for the discriminant.
10939 Build_Discriminal (Id);
10942 Discr_Number := Discr_Number + 1;
10945 Set_Has_Discriminants (Current_Scope);
10946 end Process_Discriminants;
10948 -----------------------
10949 -- Process_Full_View --
10950 -----------------------
10952 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
10953 Priv_Parent : Entity_Id;
10954 Full_Parent : Entity_Id;
10955 Full_Indic : Node_Id;
10958 -- First some sanity checks that must be done after semantic
10959 -- decoration of the full view and thus cannot be placed with other
10960 -- similar checks in Find_Type_Name
10962 if not Is_Limited_Type (Priv_T)
10963 and then (Is_Limited_Type (Full_T)
10964 or else Is_Limited_Composite (Full_T))
10967 ("completion of nonlimited type cannot be limited", Full_T);
10969 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
10971 ("completion of nonabstract type cannot be abstract", Full_T);
10973 elsif Is_Tagged_Type (Priv_T)
10974 and then Is_Limited_Type (Priv_T)
10975 and then not Is_Limited_Type (Full_T)
10977 -- GNAT allow its own definition of Limited_Controlled to disobey
10978 -- this rule in order in ease the implementation. The next test is
10979 -- safe because Root_Controlled is defined in a private system child
10981 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
10982 Set_Is_Limited_Composite (Full_T);
10985 ("completion of limited tagged type must be limited", Full_T);
10988 elsif Is_Generic_Type (Priv_T) then
10989 Error_Msg_N ("generic type cannot have a completion", Full_T);
10992 if Is_Tagged_Type (Priv_T)
10993 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
10994 and then Is_Derived_Type (Full_T)
10996 Priv_Parent := Etype (Priv_T);
10998 -- The full view of a private extension may have been transformed
10999 -- into an unconstrained derived type declaration and a subtype
11000 -- declaration (see build_derived_record_type for details).
11002 if Nkind (N) = N_Subtype_Declaration then
11003 Full_Indic := Subtype_Indication (N);
11004 Full_Parent := Etype (Base_Type (Full_T));
11006 Full_Indic := Subtype_Indication (Type_Definition (N));
11007 Full_Parent := Etype (Full_T);
11010 -- Check that the parent type of the full type is a descendant of
11011 -- the ancestor subtype given in the private extension. If either
11012 -- entity has an Etype equal to Any_Type then we had some previous
11013 -- error situation [7.3(8)].
11015 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
11018 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
11020 ("parent of full type must descend from parent"
11021 & " of private extension", Full_Indic);
11023 -- Check the rules of 7.3(10): if the private extension inherits
11024 -- known discriminants, then the full type must also inherit those
11025 -- discriminants from the same (ancestor) type, and the parent
11026 -- subtype of the full type must be constrained if and only if
11027 -- the ancestor subtype of the private extension is constrained.
11029 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
11030 and then not Has_Unknown_Discriminants (Priv_T)
11031 and then Has_Discriminants (Base_Type (Priv_Parent))
11034 Priv_Indic : constant Node_Id :=
11035 Subtype_Indication (Parent (Priv_T));
11037 Priv_Constr : constant Boolean :=
11038 Is_Constrained (Priv_Parent)
11040 Nkind (Priv_Indic) = N_Subtype_Indication
11041 or else Is_Constrained (Entity (Priv_Indic));
11043 Full_Constr : constant Boolean :=
11044 Is_Constrained (Full_Parent)
11046 Nkind (Full_Indic) = N_Subtype_Indication
11047 or else Is_Constrained (Entity (Full_Indic));
11049 Priv_Discr : Entity_Id;
11050 Full_Discr : Entity_Id;
11053 Priv_Discr := First_Discriminant (Priv_Parent);
11054 Full_Discr := First_Discriminant (Full_Parent);
11056 while Present (Priv_Discr) and then Present (Full_Discr) loop
11057 if Original_Record_Component (Priv_Discr) =
11058 Original_Record_Component (Full_Discr)
11060 Corresponding_Discriminant (Priv_Discr) =
11061 Corresponding_Discriminant (Full_Discr)
11068 Next_Discriminant (Priv_Discr);
11069 Next_Discriminant (Full_Discr);
11072 if Present (Priv_Discr) or else Present (Full_Discr) then
11074 ("full view must inherit discriminants of the parent type"
11075 & " used in the private extension", Full_Indic);
11077 elsif Priv_Constr and then not Full_Constr then
11079 ("parent subtype of full type must be constrained",
11082 elsif Full_Constr and then not Priv_Constr then
11084 ("parent subtype of full type must be unconstrained",
11089 -- Check the rules of 7.3(12): if a partial view has neither known
11090 -- or unknown discriminants, then the full type declaration shall
11091 -- define a definite subtype.
11093 elsif not Has_Unknown_Discriminants (Priv_T)
11094 and then not Has_Discriminants (Priv_T)
11095 and then not Is_Constrained (Full_T)
11098 ("full view must define a constrained type if partial view"
11099 & " has no discriminants", Full_T);
11102 -- ??????? Do we implement the following properly ?????
11103 -- If the ancestor subtype of a private extension has constrained
11104 -- discriminants, then the parent subtype of the full view shall
11105 -- impose a statically matching constraint on those discriminants
11109 -- For untagged types, verify that a type without discriminants
11110 -- is not completed with an unconstrained type.
11112 if not Is_Indefinite_Subtype (Priv_T)
11113 and then Is_Indefinite_Subtype (Full_T)
11115 Error_Msg_N ("full view of type must be definite subtype", Full_T);
11119 -- Create a full declaration for all its subtypes recorded in
11120 -- Private_Dependents and swap them similarly to the base type.
11121 -- These are subtypes that have been define before the full
11122 -- declaration of the private type. We also swap the entry in
11123 -- Private_Dependents list so we can properly restore the
11124 -- private view on exit from the scope.
11127 Priv_Elmt : Elmt_Id;
11132 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
11133 while Present (Priv_Elmt) loop
11134 Priv := Node (Priv_Elmt);
11136 if Ekind (Priv) = E_Private_Subtype
11137 or else Ekind (Priv) = E_Limited_Private_Subtype
11138 or else Ekind (Priv) = E_Record_Subtype_With_Private
11140 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
11141 Set_Is_Itype (Full);
11142 Set_Parent (Full, Parent (Priv));
11143 Set_Associated_Node_For_Itype (Full, N);
11145 -- Now we need to complete the private subtype, but since the
11146 -- base type has already been swapped, we must also swap the
11147 -- subtypes (and thus, reverse the arguments in the call to
11148 -- Complete_Private_Subtype).
11150 Copy_And_Swap (Priv, Full);
11151 Complete_Private_Subtype (Full, Priv, Full_T, N);
11152 Replace_Elmt (Priv_Elmt, Full);
11155 Next_Elmt (Priv_Elmt);
11159 -- If the private view was tagged, copy the new Primitive
11160 -- operations from the private view to the full view.
11162 if Is_Tagged_Type (Full_T) then
11164 Priv_List : Elist_Id;
11165 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
11168 D_Type : Entity_Id;
11171 if Is_Tagged_Type (Priv_T) then
11172 Priv_List := Primitive_Operations (Priv_T);
11174 P1 := First_Elmt (Priv_List);
11175 while Present (P1) loop
11178 -- Transfer explicit primitives, not those inherited from
11179 -- parent of partial view, which will be re-inherited on
11182 if Comes_From_Source (Prim) then
11183 P2 := First_Elmt (Full_List);
11184 while Present (P2) and then Node (P2) /= Prim loop
11188 -- If not found, that is a new one
11191 Append_Elmt (Prim, Full_List);
11199 -- In this case the partial view is untagged, so here we
11200 -- locate all of the earlier primitives that need to be
11201 -- treated as dispatching (those that appear between the
11202 -- two views). Note that these additional operations must
11203 -- all be new operations (any earlier operations that
11204 -- override inherited operations of the full view will
11205 -- already have been inserted in the primitives list and
11206 -- marked as dispatching by Check_Operation_From_Private_View.
11207 -- Note that implicit "/=" operators are excluded from being
11208 -- added to the primitives list since they shouldn't be
11209 -- treated as dispatching (tagged "/=" is handled specially).
11211 Prim := Next_Entity (Full_T);
11212 while Present (Prim) and then Prim /= Priv_T loop
11213 if (Ekind (Prim) = E_Procedure
11214 or else Ekind (Prim) = E_Function)
11217 D_Type := Find_Dispatching_Type (Prim);
11220 and then (Chars (Prim) /= Name_Op_Ne
11221 or else Comes_From_Source (Prim))
11223 Check_Controlling_Formals (Full_T, Prim);
11225 if not Is_Dispatching_Operation (Prim) then
11226 Append_Elmt (Prim, Full_List);
11227 Set_Is_Dispatching_Operation (Prim, True);
11228 Set_DT_Position (Prim, No_Uint);
11231 elsif Is_Dispatching_Operation (Prim)
11232 and then D_Type /= Full_T
11235 -- Verify that it is not otherwise controlled by
11236 -- a formal or a return value ot type T.
11238 Check_Controlling_Formals (D_Type, Prim);
11242 Next_Entity (Prim);
11246 -- For the tagged case, the two views can share the same
11247 -- Primitive Operation list and the same class wide type.
11248 -- Update attributes of the class-wide type which depend on
11249 -- the full declaration.
11251 if Is_Tagged_Type (Priv_T) then
11252 Set_Primitive_Operations (Priv_T, Full_List);
11253 Set_Class_Wide_Type
11254 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
11256 -- Any other attributes should be propagated to C_W ???
11258 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
11263 end Process_Full_View;
11265 -----------------------------------
11266 -- Process_Incomplete_Dependents --
11267 -----------------------------------
11269 procedure Process_Incomplete_Dependents
11271 Full_T : Entity_Id;
11274 Inc_Elmt : Elmt_Id;
11275 Priv_Dep : Entity_Id;
11276 New_Subt : Entity_Id;
11278 Disc_Constraint : Elist_Id;
11281 if No (Private_Dependents (Inc_T)) then
11285 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
11287 -- Itypes that may be generated by the completion of an incomplete
11288 -- subtype are not used by the back-end and not attached to the tree.
11289 -- They are created only for constraint-checking purposes.
11292 while Present (Inc_Elmt) loop
11293 Priv_Dep := Node (Inc_Elmt);
11295 if Ekind (Priv_Dep) = E_Subprogram_Type then
11297 -- An Access_To_Subprogram type may have a return type or a
11298 -- parameter type that is incomplete. Replace with the full view.
11300 if Etype (Priv_Dep) = Inc_T then
11301 Set_Etype (Priv_Dep, Full_T);
11305 Formal : Entity_Id;
11308 Formal := First_Formal (Priv_Dep);
11310 while Present (Formal) loop
11312 if Etype (Formal) = Inc_T then
11313 Set_Etype (Formal, Full_T);
11316 Next_Formal (Formal);
11320 elsif Is_Overloadable (Priv_Dep) then
11322 if Is_Tagged_Type (Full_T) then
11324 -- Subprogram has an access parameter whose designated type
11325 -- was incomplete. Reexamine declaration now, because it may
11326 -- be a primitive operation of the full type.
11328 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
11329 Set_Is_Dispatching_Operation (Priv_Dep);
11330 Check_Controlling_Formals (Full_T, Priv_Dep);
11333 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
11335 -- Can happen during processing of a body before the completion
11336 -- of a TA type. Ignore, because spec is also on dependent list.
11340 -- Dependent is a subtype
11343 -- We build a new subtype indication using the full view of the
11344 -- incomplete parent. The discriminant constraints have been
11345 -- elaborated already at the point of the subtype declaration.
11347 New_Subt := Create_Itype (E_Void, N);
11349 if Has_Discriminants (Full_T) then
11350 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
11352 Disc_Constraint := No_Elist;
11355 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
11356 Set_Full_View (Priv_Dep, New_Subt);
11359 Next_Elmt (Inc_Elmt);
11362 end Process_Incomplete_Dependents;
11364 --------------------------------
11365 -- Process_Range_Expr_In_Decl --
11366 --------------------------------
11368 procedure Process_Range_Expr_In_Decl
11371 Related_Nod : Node_Id;
11372 Check_List : List_Id := Empty_List;
11373 R_Check_Off : Boolean := False)
11376 R_Checks : Check_Result;
11377 Type_Decl : Node_Id;
11378 Def_Id : Entity_Id;
11381 Analyze_And_Resolve (R, Base_Type (T));
11383 if Nkind (R) = N_Range then
11384 Lo := Low_Bound (R);
11385 Hi := High_Bound (R);
11387 -- If there were errors in the declaration, try and patch up some
11388 -- common mistakes in the bounds. The cases handled are literals
11389 -- which are Integer where the expected type is Real and vice versa.
11390 -- These corrections allow the compilation process to proceed further
11391 -- along since some basic assumptions of the format of the bounds
11394 if Etype (R) = Any_Type then
11396 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
11398 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
11400 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
11402 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
11404 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
11406 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
11408 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
11410 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
11417 -- If the bounds of the range have been mistakenly given as
11418 -- string literals (perhaps in place of character literals),
11419 -- then an error has already been reported, but we rewrite
11420 -- the string literal as a bound of the range's type to
11421 -- avoid blowups in later processing that looks at static
11424 if Nkind (Lo) = N_String_Literal then
11426 Make_Attribute_Reference (Sloc (Lo),
11427 Attribute_Name => Name_First,
11428 Prefix => New_Reference_To (T, Sloc (Lo))));
11429 Analyze_And_Resolve (Lo);
11432 if Nkind (Hi) = N_String_Literal then
11434 Make_Attribute_Reference (Sloc (Hi),
11435 Attribute_Name => Name_First,
11436 Prefix => New_Reference_To (T, Sloc (Hi))));
11437 Analyze_And_Resolve (Hi);
11440 -- If bounds aren't scalar at this point then exit, avoiding
11441 -- problems with further processing of the range in this procedure.
11443 if not Is_Scalar_Type (Etype (Lo)) then
11447 -- Resolve (actually Sem_Eval) has checked that the bounds are in
11448 -- then range of the base type. Here we check whether the bounds
11449 -- are in the range of the subtype itself. Note that if the bounds
11450 -- represent the null range the Constraint_Error exception should
11453 -- ??? The following code should be cleaned up as follows
11454 -- 1. The Is_Null_Range (Lo, Hi) test should disapper since it
11455 -- is done in the call to Range_Check (R, T); below
11456 -- 2. The use of R_Check_Off should be investigated and possibly
11457 -- removed, this would clean up things a bit.
11459 if Is_Null_Range (Lo, Hi) then
11463 -- We use a flag here instead of suppressing checks on the
11464 -- type because the type we check against isn't necessarily the
11465 -- place where we put the check.
11467 if not R_Check_Off then
11468 R_Checks := Range_Check (R, T);
11469 Type_Decl := Parent (R);
11471 -- Look up tree to find an appropriate insertion point.
11472 -- This seems really junk code, and very brittle, couldn't
11473 -- we just use an insert actions call of some kind ???
11475 while Present (Type_Decl) and then not
11476 (Nkind (Type_Decl) = N_Full_Type_Declaration
11478 Nkind (Type_Decl) = N_Subtype_Declaration
11480 Nkind (Type_Decl) = N_Loop_Statement
11482 Nkind (Type_Decl) = N_Task_Type_Declaration
11484 Nkind (Type_Decl) = N_Single_Task_Declaration
11486 Nkind (Type_Decl) = N_Protected_Type_Declaration
11488 Nkind (Type_Decl) = N_Single_Protected_Declaration)
11490 Type_Decl := Parent (Type_Decl);
11493 -- Why would Type_Decl not be present??? Without this test,
11494 -- short regression tests fail.
11496 if Present (Type_Decl) then
11497 if Nkind (Type_Decl) = N_Loop_Statement then
11499 Indic : Node_Id := Parent (R);
11501 while Present (Indic) and then not
11502 (Nkind (Indic) = N_Subtype_Indication)
11504 Indic := Parent (Indic);
11507 if Present (Indic) then
11508 Def_Id := Etype (Subtype_Mark (Indic));
11510 Insert_Range_Checks
11516 Do_Before => True);
11520 Def_Id := Defining_Identifier (Type_Decl);
11522 if (Ekind (Def_Id) = E_Record_Type
11523 and then Depends_On_Discriminant (R))
11525 (Ekind (Def_Id) = E_Protected_Type
11526 and then Has_Discriminants (Def_Id))
11528 Append_Range_Checks
11529 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
11532 Insert_Range_Checks
11533 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
11542 Get_Index_Bounds (R, Lo, Hi);
11544 if Expander_Active then
11545 Force_Evaluation (Lo);
11546 Force_Evaluation (Hi);
11549 end Process_Range_Expr_In_Decl;
11551 --------------------------------------
11552 -- Process_Real_Range_Specification --
11553 --------------------------------------
11555 procedure Process_Real_Range_Specification (Def : Node_Id) is
11556 Spec : constant Node_Id := Real_Range_Specification (Def);
11559 Err : Boolean := False;
11561 procedure Analyze_Bound (N : Node_Id);
11562 -- Analyze and check one bound
11564 procedure Analyze_Bound (N : Node_Id) is
11566 Analyze_And_Resolve (N, Any_Real);
11568 if not Is_OK_Static_Expression (N) then
11570 ("bound in real type definition is not static", N);
11576 if Present (Spec) then
11577 Lo := Low_Bound (Spec);
11578 Hi := High_Bound (Spec);
11579 Analyze_Bound (Lo);
11580 Analyze_Bound (Hi);
11582 -- If error, clear away junk range specification
11585 Set_Real_Range_Specification (Def, Empty);
11588 end Process_Real_Range_Specification;
11590 ---------------------
11591 -- Process_Subtype --
11592 ---------------------
11594 function Process_Subtype
11596 Related_Nod : Node_Id;
11597 Related_Id : Entity_Id := Empty;
11598 Suffix : Character := ' ')
11602 Def_Id : Entity_Id;
11603 Full_View_Id : Entity_Id;
11604 Subtype_Mark_Id : Entity_Id;
11605 N_Dynamic_Ityp : Node_Id := Empty;
11608 -- Case of constraint present, so that we have an N_Subtype_Indication
11609 -- node (this node is created only if constraints are present).
11611 if Nkind (S) = N_Subtype_Indication then
11612 Find_Type (Subtype_Mark (S));
11614 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
11616 (Nkind (Parent (S)) = N_Subtype_Declaration
11618 Is_Itype (Defining_Identifier (Parent (S))))
11620 Check_Incomplete (Subtype_Mark (S));
11624 Subtype_Mark_Id := Entity (Subtype_Mark (S));
11626 if Is_Unchecked_Union (Subtype_Mark_Id)
11627 and then Comes_From_Source (Related_Nod)
11630 ("cannot create subtype of Unchecked_Union", Related_Nod);
11633 -- Explicit subtype declaration case
11635 if Nkind (P) = N_Subtype_Declaration then
11636 Def_Id := Defining_Identifier (P);
11638 -- Explicit derived type definition case
11640 elsif Nkind (P) = N_Derived_Type_Definition then
11641 Def_Id := Defining_Identifier (Parent (P));
11643 -- Implicit case, the Def_Id must be created as an implicit type.
11644 -- The one exception arises in the case of concurrent types,
11645 -- array and access types, where other subsidiary implicit types
11646 -- may be created and must appear before the main implicit type.
11647 -- In these cases we leave Def_Id set to Empty as a signal that
11648 -- Create_Itype has not yet been called to create Def_Id.
11651 if Is_Array_Type (Subtype_Mark_Id)
11652 or else Is_Concurrent_Type (Subtype_Mark_Id)
11653 or else Is_Access_Type (Subtype_Mark_Id)
11657 -- For the other cases, we create a new unattached Itype,
11658 -- and set the indication to ensure it gets attached later.
11662 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11665 N_Dynamic_Ityp := Related_Nod;
11668 -- If the kind of constraint is invalid for this kind of type,
11669 -- then give an error, and then pretend no constraint was given.
11671 if not Is_Valid_Constraint_Kind
11672 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
11675 ("incorrect constraint for this kind of type", Constraint (S));
11677 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
11679 -- Make recursive call, having got rid of the bogus constraint
11681 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
11684 -- Remaining processing depends on type
11686 case Ekind (Subtype_Mark_Id) is
11688 when Access_Kind =>
11689 Constrain_Access (Def_Id, S, Related_Nod);
11692 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
11694 when Decimal_Fixed_Point_Kind =>
11695 Constrain_Decimal (Def_Id, S, N_Dynamic_Ityp);
11697 when Enumeration_Kind =>
11698 Constrain_Enumeration (Def_Id, S, N_Dynamic_Ityp);
11700 when Ordinary_Fixed_Point_Kind =>
11701 Constrain_Ordinary_Fixed (Def_Id, S, N_Dynamic_Ityp);
11704 Constrain_Float (Def_Id, S, N_Dynamic_Ityp);
11706 when Integer_Kind =>
11707 Constrain_Integer (Def_Id, S, N_Dynamic_Ityp);
11709 when E_Record_Type |
11712 E_Incomplete_Type =>
11713 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11715 when Private_Kind =>
11716 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11717 Set_Private_Dependents (Def_Id, New_Elmt_List);
11719 -- In case of an invalid constraint prevent further processing
11720 -- since the type constructed is missing expected fields.
11722 if Etype (Def_Id) = Any_Type then
11726 -- If the full view is that of a task with discriminants,
11727 -- we must constrain both the concurrent type and its
11728 -- corresponding record type. Otherwise we will just propagate
11729 -- the constraint to the full view, if available.
11731 if Present (Full_View (Subtype_Mark_Id))
11732 and then Has_Discriminants (Subtype_Mark_Id)
11733 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
11736 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11738 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
11739 Constrain_Concurrent (Full_View_Id, S,
11740 Related_Nod, Related_Id, Suffix);
11741 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
11742 Set_Full_View (Def_Id, Full_View_Id);
11745 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
11748 when Concurrent_Kind =>
11749 Constrain_Concurrent (Def_Id, S,
11750 Related_Nod, Related_Id, Suffix);
11753 Error_Msg_N ("invalid subtype mark in subtype indication", S);
11756 -- Size and Convention are always inherited from the base type
11758 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
11759 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
11763 -- Case of no constraints present
11767 Check_Incomplete (S);
11770 end Process_Subtype;
11772 -----------------------------
11773 -- Record_Type_Declaration --
11774 -----------------------------
11776 procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id) is
11777 Def : constant Node_Id := Type_Definition (N);
11778 Range_Checks_Suppressed_Flag : Boolean := False;
11780 Is_Tagged : Boolean;
11781 Tag_Comp : Entity_Id;
11784 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
11785 -- if it detected an error for declaration T. This arises in the case of
11786 -- private tagged types where the full view omits the word tagged.
11788 Is_Tagged := Tagged_Present (Def)
11789 or else (Errors_Detected > 0 and then Is_Tagged_Type (T));
11791 -- Records constitute a scope for the component declarations within.
11792 -- The scope is created prior to the processing of these declarations.
11793 -- Discriminants are processed first, so that they are visible when
11794 -- processing the other components. The Ekind of the record type itself
11795 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
11797 -- Enter record scope
11801 -- These flags must be initialized before calling Process_Discriminants
11802 -- because this routine makes use of them.
11804 Set_Is_Tagged_Type (T, Is_Tagged);
11805 Set_Is_Limited_Record (T, Limited_Present (Def));
11807 -- Type is abstract if full declaration carries keyword, or if
11808 -- previous partial view did.
11810 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
11812 Set_Ekind (T, E_Record_Type);
11814 Init_Size_Align (T);
11816 Set_Girder_Constraint (T, No_Elist);
11818 -- If an incomplete or private type declaration was already given for
11819 -- the type, then this scope already exists, and the discriminants have
11820 -- been declared within. We must verify that the full declaration
11821 -- matches the incomplete one.
11823 Check_Or_Process_Discriminants (N, T);
11825 Set_Is_Constrained (T, not Has_Discriminants (T));
11826 Set_Has_Delayed_Freeze (T, True);
11828 -- For tagged types add a manually analyzed component corresponding
11829 -- to the component _tag, the corresponding piece of tree will be
11830 -- expanded as part of the freezing actions if it is not a CPP_Class.
11833 -- Do not add the tag unless we are in expansion mode.
11835 if Expander_Active then
11836 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
11837 Enter_Name (Tag_Comp);
11839 Set_Is_Tag (Tag_Comp);
11840 Set_Ekind (Tag_Comp, E_Component);
11841 Set_Etype (Tag_Comp, RTE (RE_Tag));
11842 Set_DT_Entry_Count (Tag_Comp, No_Uint);
11843 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
11844 Init_Component_Location (Tag_Comp);
11847 Make_Class_Wide_Type (T);
11848 Set_Primitive_Operations (T, New_Elmt_List);
11851 -- We must suppress range checks when processing the components
11852 -- of a record in the presence of discriminants, since we don't
11853 -- want spurious checks to be generated during their analysis, but
11854 -- must reset the Suppress_Range_Checks flags after having procesed
11855 -- the record definition.
11857 if Has_Discriminants (T) and then not Suppress_Range_Checks (T) then
11858 Set_Suppress_Range_Checks (T, True);
11859 Range_Checks_Suppressed_Flag := True;
11862 Record_Type_Definition (Def, T);
11864 if Range_Checks_Suppressed_Flag then
11865 Set_Suppress_Range_Checks (T, False);
11866 Range_Checks_Suppressed_Flag := False;
11869 -- Exit from record scope
11872 end Record_Type_Declaration;
11874 ----------------------------
11875 -- Record_Type_Definition --
11876 ----------------------------
11878 procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id) is
11879 Component : Entity_Id;
11880 Ctrl_Components : Boolean := False;
11881 Final_Storage_Only : Boolean := not Is_Controlled (T);
11884 -- If the component list of a record type is defined by the reserved
11885 -- word null and there is no discriminant part, then the record type has
11886 -- no components and all records of the type are null records (RM 3.7)
11887 -- This procedure is also called to process the extension part of a
11888 -- record extension, in which case the current scope may have inherited
11892 or else No (Component_List (Def))
11893 or else Null_Present (Component_List (Def))
11898 Analyze_Declarations (Component_Items (Component_List (Def)));
11900 if Present (Variant_Part (Component_List (Def))) then
11901 Analyze (Variant_Part (Component_List (Def)));
11905 -- After completing the semantic analysis of the record definition,
11906 -- record components, both new and inherited, are accessible. Set
11907 -- their kind accordingly.
11909 Component := First_Entity (Current_Scope);
11910 while Present (Component) loop
11912 if Ekind (Component) = E_Void then
11913 Set_Ekind (Component, E_Component);
11914 Init_Component_Location (Component);
11917 if Has_Task (Etype (Component)) then
11921 if Ekind (Component) /= E_Component then
11924 elsif Has_Controlled_Component (Etype (Component))
11925 or else (Chars (Component) /= Name_uParent
11926 and then Is_Controlled (Etype (Component)))
11928 Set_Has_Controlled_Component (T, True);
11929 Final_Storage_Only := Final_Storage_Only
11930 and then Finalize_Storage_Only (Etype (Component));
11931 Ctrl_Components := True;
11934 Next_Entity (Component);
11937 -- A type is Finalize_Storage_Only only if all its controlled
11938 -- components are so.
11940 if Ctrl_Components then
11941 Set_Finalize_Storage_Only (T, Final_Storage_Only);
11944 if Present (Def) then
11945 Process_End_Label (Def, 'e');
11947 end Record_Type_Definition;
11949 ---------------------
11950 -- Set_Fixed_Range --
11951 ---------------------
11953 -- The range for fixed-point types is complicated by the fact that we
11954 -- do not know the exact end points at the time of the declaration. This
11955 -- is true for three reasons:
11957 -- A size clause may affect the fudging of the end-points
11958 -- A small clause may affect the values of the end-points
11959 -- We try to include the end-points if it does not affect the size
11961 -- This means that the actual end-points must be established at the
11962 -- point when the type is frozen. Meanwhile, we first narrow the range
11963 -- as permitted (so that it will fit if necessary in a small specified
11964 -- size), and then build a range subtree with these narrowed bounds.
11966 -- Set_Fixed_Range constructs the range from real literal values, and
11967 -- sets the range as the Scalar_Range of the given fixed-point type
11970 -- The parent of this range is set to point to the entity so that it
11971 -- is properly hooked into the tree (unlike normal Scalar_Range entries
11972 -- for other scalar types, which are just pointers to the range in the
11973 -- original tree, this would otherwise be an orphan).
11975 -- The tree is left unanalyzed. When the type is frozen, the processing
11976 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
11977 -- analyzed, and uses this as an indication that it should complete
11978 -- work on the range (it will know the final small and size values).
11980 procedure Set_Fixed_Range
11986 S : constant Node_Id :=
11988 Low_Bound => Make_Real_Literal (Loc, Lo),
11989 High_Bound => Make_Real_Literal (Loc, Hi));
11992 Set_Scalar_Range (E, S);
11994 end Set_Fixed_Range;
11996 --------------------------------------------------------
11997 -- Set_Girder_Constraint_From_Discriminant_Constraint --
11998 --------------------------------------------------------
12000 procedure Set_Girder_Constraint_From_Discriminant_Constraint
12004 -- Make sure set if encountered during
12005 -- Expand_To_Girder_Constraint
12007 Set_Girder_Constraint (E, No_Elist);
12009 -- Give it the right value
12011 if Is_Constrained (E) and then Has_Discriminants (E) then
12012 Set_Girder_Constraint (E,
12013 Expand_To_Girder_Constraint (E, Discriminant_Constraint (E)));
12016 end Set_Girder_Constraint_From_Discriminant_Constraint;
12018 ----------------------------------
12019 -- Set_Scalar_Range_For_Subtype --
12020 ----------------------------------
12022 procedure Set_Scalar_Range_For_Subtype
12023 (Def_Id : Entity_Id;
12026 Related_Nod : Node_Id)
12028 Kind : constant Entity_Kind := Ekind (Def_Id);
12030 Set_Scalar_Range (Def_Id, R);
12032 -- We need to link the range into the tree before resolving it so
12033 -- that types that are referenced, including importantly the subtype
12034 -- itself, are properly frozen (Freeze_Expression requires that the
12035 -- expression be properly linked into the tree). Of course if it is
12036 -- already linked in, then we do not disturb the current link.
12038 if No (Parent (R)) then
12039 Set_Parent (R, Def_Id);
12042 -- Reset the kind of the subtype during analysis of the range, to
12043 -- catch possible premature use in the bounds themselves.
12045 Set_Ekind (Def_Id, E_Void);
12046 Process_Range_Expr_In_Decl (R, Subt, Related_Nod);
12047 Set_Ekind (Def_Id, Kind);
12049 end Set_Scalar_Range_For_Subtype;
12051 -------------------------------------
12052 -- Signed_Integer_Type_Declaration --
12053 -------------------------------------
12055 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
12056 Implicit_Base : Entity_Id;
12057 Base_Typ : Entity_Id;
12060 Errs : Boolean := False;
12064 function Can_Derive_From (E : Entity_Id) return Boolean;
12065 -- Determine whether given bounds allow derivation from specified type
12067 procedure Check_Bound (Expr : Node_Id);
12068 -- Check bound to make sure it is integral and static. If not, post
12069 -- appropriate error message and set Errs flag
12071 function Can_Derive_From (E : Entity_Id) return Boolean is
12072 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
12073 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
12076 -- Note we check both bounds against both end values, to deal with
12077 -- strange types like ones with a range of 0 .. -12341234.
12079 return Lo <= Lo_Val and then Lo_Val <= Hi
12081 Lo <= Hi_Val and then Hi_Val <= Hi;
12082 end Can_Derive_From;
12084 procedure Check_Bound (Expr : Node_Id) is
12086 -- If a range constraint is used as an integer type definition, each
12087 -- bound of the range must be defined by a static expression of some
12088 -- integer type, but the two bounds need not have the same integer
12089 -- type (Negative bounds are allowed.) (RM 3.5.4)
12091 if not Is_Integer_Type (Etype (Expr)) then
12093 ("integer type definition bounds must be of integer type", Expr);
12096 elsif not Is_OK_Static_Expression (Expr) then
12098 ("non-static expression used for integer type bound", Expr);
12101 -- The bounds are folded into literals, and we set their type to be
12102 -- universal, to avoid typing difficulties: we cannot set the type
12103 -- of the literal to the new type, because this would be a forward
12104 -- reference for the back end, and if the original type is user-
12105 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
12108 if Is_Entity_Name (Expr) then
12109 Fold_Uint (Expr, Expr_Value (Expr));
12112 Set_Etype (Expr, Universal_Integer);
12116 -- Start of processing for Signed_Integer_Type_Declaration
12119 -- Create an anonymous base type
12122 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
12124 -- Analyze and check the bounds, they can be of any integer type
12126 Lo := Low_Bound (Def);
12127 Hi := High_Bound (Def);
12129 -- Arbitrarily use Integer as the type if either bound had an error
12131 if Hi = Error or else Lo = Error then
12132 Base_Typ := Any_Integer;
12133 Set_Error_Posted (T, True);
12135 -- Here both bounds are OK expressions
12138 Analyze_And_Resolve (Lo, Any_Integer);
12139 Analyze_And_Resolve (Hi, Any_Integer);
12145 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12146 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12149 -- Find type to derive from
12151 Lo_Val := Expr_Value (Lo);
12152 Hi_Val := Expr_Value (Hi);
12154 if Can_Derive_From (Standard_Short_Short_Integer) then
12155 Base_Typ := Base_Type (Standard_Short_Short_Integer);
12157 elsif Can_Derive_From (Standard_Short_Integer) then
12158 Base_Typ := Base_Type (Standard_Short_Integer);
12160 elsif Can_Derive_From (Standard_Integer) then
12161 Base_Typ := Base_Type (Standard_Integer);
12163 elsif Can_Derive_From (Standard_Long_Integer) then
12164 Base_Typ := Base_Type (Standard_Long_Integer);
12166 elsif Can_Derive_From (Standard_Long_Long_Integer) then
12167 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12170 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12171 Error_Msg_N ("integer type definition bounds out of range", Def);
12172 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12173 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12177 -- Complete both implicit base and declared first subtype entities
12179 Set_Etype (Implicit_Base, Base_Typ);
12180 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
12181 Set_Size_Info (Implicit_Base, (Base_Typ));
12182 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
12183 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
12185 Set_Ekind (T, E_Signed_Integer_Subtype);
12186 Set_Etype (T, Implicit_Base);
12188 Set_Size_Info (T, (Implicit_Base));
12189 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
12190 Set_Scalar_Range (T, Def);
12191 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
12192 Set_Is_Constrained (T);
12194 end Signed_Integer_Type_Declaration;