1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Elists; use Elists;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Eval_Fat; use Eval_Fat;
33 with Exp_Ch3; use Exp_Ch3;
34 with Exp_Dist; use Exp_Dist;
35 with Exp_Tss; use Exp_Tss;
36 with Exp_Util; use Exp_Util;
37 with Freeze; use Freeze;
38 with Itypes; use Itypes;
39 with Layout; use Layout;
41 with Lib.Xref; use Lib.Xref;
42 with Namet; use Namet;
43 with Nmake; use Nmake;
45 with Restrict; use Restrict;
46 with Rtsfind; use Rtsfind;
48 with Sem_Case; use Sem_Case;
49 with Sem_Cat; use Sem_Cat;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch7; use Sem_Ch7;
52 with Sem_Ch8; use Sem_Ch8;
53 with Sem_Ch13; use Sem_Ch13;
54 with Sem_Disp; use Sem_Disp;
55 with Sem_Dist; use Sem_Dist;
56 with Sem_Elim; use Sem_Elim;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Mech; use Sem_Mech;
59 with Sem_Res; use Sem_Res;
60 with Sem_Smem; use Sem_Smem;
61 with Sem_Type; use Sem_Type;
62 with Sem_Util; use Sem_Util;
63 with Sem_Warn; use Sem_Warn;
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 -- Subsidiary 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;
172 Discs : Elist_Id) return Elist_Id;
173 -- Called from Build_Derived_Record_Type to inherit the components of
174 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
175 -- For more information on derived types and component inheritance please
176 -- consult the comment above the body of Build_Derived_Record_Type.
178 -- N is the original derived type declaration.
180 -- Is_Tagged is set if we are dealing with tagged types.
182 -- If Inherit_Discr is set, Derived_Base inherits its discriminants
183 -- from Parent_Base, otherwise no discriminants are inherited.
185 -- Discs gives the list of constraints that apply to Parent_Base in the
186 -- derived type declaration. If Discs is set to No_Elist, then we have
187 -- the following situation:
189 -- type Parent (D1..Dn : ..) is [tagged] record ...;
190 -- type Derived is new Parent [with ...];
192 -- which gets treated as
194 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
196 -- For untagged types the returned value is an association list. The list
197 -- starts from the association (Parent_Base => Derived_Base), and then it
198 -- contains a sequence of the associations of the form
200 -- (Old_Component => New_Component),
202 -- where Old_Component is the Entity_Id of a component in Parent_Base
203 -- and New_Component is the Entity_Id of the corresponding component
204 -- in Derived_Base. For untagged records, this association list is
205 -- needed when copying the record declaration for the derived base.
206 -- In the tagged case the value returned is irrelevant.
208 procedure Build_Discriminal (Discrim : Entity_Id);
209 -- Create the discriminal corresponding to discriminant Discrim, that is
210 -- the parameter corresponding to Discrim to be used in initialization
211 -- procedures for the type where Discrim is a discriminant. Discriminals
212 -- are not used during semantic analysis, and are not fully defined
213 -- entities until expansion. Thus they are not given a scope until
214 -- initialization procedures are built.
216 function Build_Discriminant_Constraints
219 Derived_Def : Boolean := False) return Elist_Id;
220 -- Validate discriminant constraints, and return the list of the
221 -- constraints in order of discriminant declarations. T is the
222 -- discriminated unconstrained type. Def is the N_Subtype_Indication
223 -- node where the discriminants constraints for T are specified.
224 -- Derived_Def is True if we are building the discriminant constraints
225 -- in a derived type definition of the form "type D (...) is new T (xxx)".
226 -- In this case T is the parent type and Def is the constraint "(xxx)" on
227 -- T and this routine sets the Corresponding_Discriminant field of the
228 -- discriminants in the derived type D to point to the corresponding
229 -- discriminants in the parent type T.
231 procedure Build_Discriminated_Subtype
235 Related_Nod : Node_Id;
236 For_Access : Boolean := False);
237 -- Subsidiary procedure to Constrain_Discriminated_Type and to
238 -- Process_Incomplete_Dependents. Given
240 -- T (a possibly discriminated base type)
241 -- Def_Id (a very partially built subtype for T),
243 -- the call completes Def_Id to be the appropriate E_*_Subtype.
245 -- The Elist is the list of discriminant constraints if any (it is set to
246 -- No_Elist if T is not a discriminated type, and to an empty list if
247 -- T has discriminants but there are no discriminant constraints). The
248 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
249 -- The For_Access says whether or not this subtype is really constraining
250 -- an access type. That is its sole purpose is the designated type of an
251 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
252 -- is built to avoid freezing T when the access subtype is frozen.
254 function Build_Scalar_Bound
257 Der_T : Entity_Id) return Node_Id;
258 -- The bounds of a derived scalar type are conversions of the bounds of
259 -- the parent type. Optimize the representation if the bounds are literals.
260 -- Needs a more complete spec--what are the parameters exactly, and what
261 -- exactly is the returned value, and how is Bound affected???
263 procedure Build_Underlying_Full_View
267 -- If the completion of a private type is itself derived from a private
268 -- type, or if the full view of a private subtype is itself private, the
269 -- back-end has no way to compute the actual size of this type. We build
270 -- an internal subtype declaration of the proper parent type to convey
271 -- this information. This extra mechanism is needed because a full
272 -- view cannot itself have a full view (it would get clobbered during
275 procedure Check_Access_Discriminant_Requires_Limited
278 -- Check the restriction that the type to which an access discriminant
279 -- belongs must be a concurrent type or a descendant of a type with
280 -- the reserved word 'limited' in its declaration.
282 procedure Check_Delta_Expression (E : Node_Id);
283 -- Check that the expression represented by E is suitable for use
284 -- as a delta expression, i.e. it is of real type and is static.
286 procedure Check_Digits_Expression (E : Node_Id);
287 -- Check that the expression represented by E is suitable for use as
288 -- a digits expression, i.e. it is of integer type, positive and static.
290 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
291 -- Validate the initialization of an object declaration. T is the
292 -- required type, and Exp is the initialization expression.
294 procedure Check_Or_Process_Discriminants
297 Prev : Entity_Id := Empty);
298 -- If T is the full declaration of an incomplete or private type, check
299 -- the conformance of the discriminants, otherwise process them. Prev
300 -- is the entity of the partial declaration, if any.
302 procedure Check_Real_Bound (Bound : Node_Id);
303 -- Check given bound for being of real type and static. If not, post an
304 -- appropriate message, and rewrite the bound with the real literal zero.
306 procedure Constant_Redeclaration
310 -- Various checks on legality of full declaration of deferred constant.
311 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
312 -- node. The caller has not yet set any attributes of this entity.
314 procedure Convert_Scalar_Bounds
316 Parent_Type : Entity_Id;
317 Derived_Type : Entity_Id;
319 -- For derived scalar types, convert the bounds in the type definition
320 -- to the derived type, and complete their analysis. Given a constraint
322 -- .. new T range Lo .. Hi;
323 -- Lo and Hi are analyzed and resolved with T'Base, the parent_type.
324 -- The bounds of the derived type (the anonymous base) are copies of
325 -- Lo and Hi. Finally, the bounds of the derived subtype are conversions
326 -- of those bounds to the derived_type, so that their typing is
329 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
330 -- Copies attributes from array base type T2 to array base type T1.
331 -- Copies only attributes that apply to base types, but not subtypes.
333 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
334 -- Copies attributes from array subtype T2 to array subtype T1. Copies
335 -- attributes that apply to both subtypes and base types.
337 procedure Create_Constrained_Components
341 Constraints : Elist_Id);
342 -- Build the list of entities for a constrained discriminated record
343 -- subtype. If a component depends on a discriminant, replace its subtype
344 -- using the discriminant values in the discriminant constraint.
345 -- Subt is the defining identifier for the subtype whose list of
346 -- constrained entities we will create. Decl_Node is the type declaration
347 -- node where we will attach all the itypes created. Typ is the base
348 -- discriminated type for the subtype Subt. Constraints is the list of
349 -- discriminant constraints for Typ.
351 function Constrain_Component_Type
352 (Compon_Type : Entity_Id;
353 Constrained_Typ : Entity_Id;
354 Related_Node : Node_Id;
356 Constraints : Elist_Id) return Entity_Id;
357 -- Given a discriminated base type Typ, a list of discriminant constraint
358 -- Constraints for Typ and the type of a component of Typ, Compon_Type,
359 -- create and return the type corresponding to Compon_type where all
360 -- discriminant references are replaced with the corresponding
361 -- constraint. If no discriminant references occur in Compon_Typ then
362 -- return it as is. Constrained_Typ is the final constrained subtype to
363 -- which the constrained Compon_Type belongs. Related_Node is the node
364 -- where we will attach all the itypes created.
366 procedure Constrain_Access
367 (Def_Id : in out Entity_Id;
369 Related_Nod : Node_Id);
370 -- Apply a list of constraints to an access type. If Def_Id is empty,
371 -- it is an anonymous type created for a subtype indication. In that
372 -- case it is created in the procedure and attached to Related_Nod.
374 procedure Constrain_Array
375 (Def_Id : in out Entity_Id;
377 Related_Nod : Node_Id;
378 Related_Id : Entity_Id;
380 -- Apply a list of index constraints to an unconstrained array type. The
381 -- first parameter is the entity for the resulting subtype. A value of
382 -- Empty for Def_Id indicates that an implicit type must be created, but
383 -- creation is delayed (and must be done by this procedure) because other
384 -- subsidiary implicit types must be created first (which is why Def_Id
385 -- is an in/out parameter). The second parameter is a subtype indication
386 -- node for the constrained array to be created (e.g. something of the
387 -- form string (1 .. 10)). Related_Nod gives the place where this type
388 -- has to be inserted in the tree. The Related_Id and Suffix parameters
389 -- are used to build the associated Implicit type name.
391 procedure Constrain_Concurrent
392 (Def_Id : in out Entity_Id;
394 Related_Nod : Node_Id;
395 Related_Id : Entity_Id;
397 -- Apply list of discriminant constraints to an unconstrained concurrent
400 -- SI is the N_Subtype_Indication node containing the constraint and
401 -- the unconstrained type to constrain.
403 -- Def_Id is the entity for the resulting constrained subtype. A
404 -- value of Empty for Def_Id indicates that an implicit type must be
405 -- created, but creation is delayed (and must be done by this procedure)
406 -- because other subsidiary implicit types must be created first (which
407 -- is why Def_Id is an in/out parameter).
409 -- Related_Nod gives the place where this type has to be inserted
412 -- The last two arguments are used to create its external name if needed.
414 function Constrain_Corresponding_Record
415 (Prot_Subt : Entity_Id;
416 Corr_Rec : Entity_Id;
417 Related_Nod : Node_Id;
418 Related_Id : Entity_Id) return Entity_Id;
419 -- When constraining a protected type or task type with discriminants,
420 -- constrain the corresponding record with the same discriminant values.
422 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
423 -- Constrain a decimal fixed point type with a digits constraint and/or a
424 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
426 procedure Constrain_Discriminated_Type
429 Related_Nod : Node_Id;
430 For_Access : Boolean := False);
431 -- Process discriminant constraints of composite type. Verify that values
432 -- have been provided for all discriminants, that the original type is
433 -- unconstrained, and that the types of the supplied expressions match
434 -- the discriminant types. The first three parameters are like in routine
435 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
438 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
439 -- Constrain an enumeration type with a range constraint. This is
440 -- identical to Constrain_Integer, but for the Ekind of the
441 -- resulting subtype.
443 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
444 -- Constrain a floating point type with either a digits constraint
445 -- and/or a range constraint, building a E_Floating_Point_Subtype.
447 procedure Constrain_Index
450 Related_Nod : Node_Id;
451 Related_Id : Entity_Id;
454 -- Process an index constraint in a constrained array declaration.
455 -- The constraint can be a subtype name, or a range with or without
456 -- an explicit subtype mark. The index is the corresponding index of the
457 -- unconstrained array. The Related_Id and Suffix parameters are used to
458 -- build the associated Implicit type name.
460 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
461 -- Build subtype of a signed or modular integer type.
463 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
464 -- Constrain an ordinary fixed point type with a range constraint, and
465 -- build an E_Ordinary_Fixed_Point_Subtype entity.
467 procedure Copy_And_Swap (Priv, Full : Entity_Id);
468 -- Copy the Priv entity into the entity of its full declaration
469 -- then swap the two entities in such a manner that the former private
470 -- type is now seen as a full type.
472 procedure Decimal_Fixed_Point_Type_Declaration
475 -- Create a new decimal fixed point type, and apply the constraint to
476 -- obtain a subtype of this new type.
478 procedure Complete_Private_Subtype
481 Full_Base : Entity_Id;
482 Related_Nod : Node_Id);
483 -- Complete the implicit full view of a private subtype by setting
484 -- the appropriate semantic fields. If the full view of the parent is
485 -- a record type, build constrained components of subtype.
487 procedure Derived_Standard_Character
489 Parent_Type : Entity_Id;
490 Derived_Type : Entity_Id);
491 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
492 -- derivations from types Standard.Character and Standard.Wide_Character.
494 procedure Derived_Type_Declaration
497 Is_Completion : Boolean);
498 -- Process a derived type declaration. This routine will invoke
499 -- Build_Derived_Type to process the actual derived type definition.
500 -- Parameters N and Is_Completion have the same meaning as in
501 -- Build_Derived_Type. T is the N_Defining_Identifier for the entity
502 -- defined in the N_Full_Type_Declaration node N, that is T is the
505 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
506 -- Given a subtype indication S (which is really an N_Subtype_Indication
507 -- node or a plain N_Identifier), find the type of the subtype mark.
509 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
510 -- Insert each literal in symbol table, as an overloadable identifier
511 -- Each enumeration type is mapped into a sequence of integers, and
512 -- each literal is defined as a constant with integer value. If any
513 -- of the literals are character literals, the type is a character
514 -- type, which means that strings are legal aggregates for arrays of
515 -- components of the type.
517 function Expand_To_Stored_Constraint
519 Constraint : Elist_Id) return Elist_Id;
520 -- Given a Constraint (ie a list of expressions) on the discriminants of
521 -- Typ, expand it into a constraint on the stored discriminants and
522 -- return the new list of expressions constraining the stored
525 function Find_Type_Of_Object
527 Related_Nod : Node_Id) return Entity_Id;
528 -- Get type entity for object referenced by Obj_Def, attaching the
529 -- implicit types generated to Related_Nod
531 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
532 -- Create a new float, and apply the constraint to obtain subtype of it
534 function Has_Range_Constraint (N : Node_Id) return Boolean;
535 -- Given an N_Subtype_Indication node N, return True if a range constraint
536 -- is present, either directly, or as part of a digits or delta constraint.
537 -- In addition, a digits constraint in the decimal case returns True, since
538 -- it establishes a default range if no explicit range is present.
540 function Is_Valid_Constraint_Kind
542 Constraint_Kind : Node_Kind) return Boolean;
543 -- Returns True if it is legal to apply the given kind of constraint
544 -- to the given kind of type (index constraint to an array type,
547 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
548 -- Create new modular type. Verify that modulus is in bounds and is
549 -- a power of two (implementation restriction).
551 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id);
552 -- Create an abbreviated declaration for an operator in order to
553 -- materialize minimally operators on derived types.
555 procedure Ordinary_Fixed_Point_Type_Declaration
558 -- Create a new ordinary fixed point type, and apply the constraint
559 -- to obtain subtype of it.
561 procedure Prepare_Private_Subtype_Completion
563 Related_Nod : Node_Id);
564 -- Id is a subtype of some private type. Creates the full declaration
565 -- associated with Id whenever possible, i.e. when the full declaration
566 -- of the base type is already known. Records each subtype into
567 -- Private_Dependents of the base type.
569 procedure Process_Incomplete_Dependents
573 -- Process all entities that depend on an incomplete type. There include
574 -- subtypes, subprogram types that mention the incomplete type in their
575 -- profiles, and subprogram with access parameters that designate the
578 -- Inc_T is the defining identifier of an incomplete type declaration, its
579 -- Ekind is E_Incomplete_Type.
581 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
583 -- Full_T is N's defining identifier.
585 -- Subtypes of incomplete types with discriminants are completed when the
586 -- parent type is. This is simpler than private subtypes, because they can
587 -- only appear in the same scope, and there is no need to exchange views.
588 -- Similarly, access_to_subprogram types may have a parameter or a return
589 -- type that is an incomplete type, and that must be replaced with the
592 -- If the full type is tagged, subprogram with access parameters that
593 -- designated the incomplete may be primitive operations of the full type,
594 -- and have to be processed accordingly.
596 procedure Process_Real_Range_Specification (Def : Node_Id);
597 -- Given the type definition for a real type, this procedure processes
598 -- and checks the real range specification of this type definition if
599 -- one is present. If errors are found, error messages are posted, and
600 -- the Real_Range_Specification of Def is reset to Empty.
602 procedure Record_Type_Declaration
606 -- Process a record type declaration (for both untagged and tagged
607 -- records). Parameters T and N are exactly like in procedure
608 -- Derived_Type_Declaration, except that no flag Is_Completion is
609 -- needed for this routine. If this is the completion of an incomplete
610 -- type declaration, Prev is the entity of the incomplete declaration,
611 -- used for cross-referencing. Otherwise Prev = T.
613 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
614 -- This routine is used to process the actual record type definition
615 -- (both for untagged and tagged records). Def is a record type
616 -- definition node. This procedure analyzes the components in this
617 -- record type definition. Prev_T is the entity for the enclosing record
618 -- type. It is provided so that its Has_Task flag can be set if any of
619 -- the component have Has_Task set. If the declaration is the completion
620 -- of an incomplete type declaration, Prev_T is the original incomplete
621 -- type, whose full view is the record type.
623 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
624 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we
625 -- build a copy of the declaration tree of the parent, and we create
626 -- independently the list of components for the derived type. Semantic
627 -- information uses the component entities, but record representation
628 -- clauses are validated on the declaration tree. This procedure replaces
629 -- discriminants and components in the declaration with those that have
630 -- been created by Inherit_Components.
632 procedure Set_Fixed_Range
637 -- Build a range node with the given bounds and set it as the Scalar_Range
638 -- of the given fixed-point type entity. Loc is the source location used
639 -- for the constructed range. See body for further details.
641 procedure Set_Scalar_Range_For_Subtype
645 -- This routine is used to set the scalar range field for a subtype
646 -- given Def_Id, the entity for the subtype, and R, the range expression
647 -- for the scalar range. Subt provides the parent subtype to be used
648 -- to analyze, resolve, and check the given range.
650 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
651 -- Create a new signed integer entity, and apply the constraint to obtain
652 -- the required first named subtype of this type.
654 procedure Set_Stored_Constraint_From_Discriminant_Constraint
656 -- E is some record type. This routine computes E's Stored_Constraint
657 -- from its Discriminant_Constraint.
659 -----------------------
660 -- Access_Definition --
661 -----------------------
663 function Access_Definition
664 (Related_Nod : Node_Id;
665 N : Node_Id) return Entity_Id
667 Anon_Type : constant Entity_Id :=
668 Create_Itype (E_Anonymous_Access_Type, Related_Nod,
669 Scope_Id => Scope (Current_Scope));
670 Desig_Type : Entity_Id;
673 if Is_Entry (Current_Scope)
674 and then Is_Task_Type (Etype (Scope (Current_Scope)))
676 Error_Msg_N ("task entries cannot have access parameters", N);
679 Find_Type (Subtype_Mark (N));
680 Desig_Type := Entity (Subtype_Mark (N));
682 Set_Directly_Designated_Type
683 (Anon_Type, Desig_Type);
684 Set_Etype (Anon_Type, Anon_Type);
685 Init_Size_Align (Anon_Type);
686 Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type));
688 -- The anonymous access type is as public as the discriminated type or
689 -- subprogram that defines it. It is imported (for back-end purposes)
690 -- if the designated type is.
692 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
693 Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type));
695 -- The context is either a subprogram declaration or an access
696 -- discriminant, in a private or a full type declaration. In
697 -- the case of a subprogram, If the designated type is incomplete,
698 -- the operation will be a primitive operation of the full type, to
699 -- be updated subsequently.
701 if Ekind (Desig_Type) = E_Incomplete_Type
702 and then Is_Overloadable (Current_Scope)
704 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
705 Set_Has_Delayed_Freeze (Current_Scope);
709 end Access_Definition;
711 -----------------------------------
712 -- Access_Subprogram_Declaration --
713 -----------------------------------
715 procedure Access_Subprogram_Declaration
719 Formals : constant List_Id := Parameter_Specifications (T_Def);
722 Desig_Type : constant Entity_Id :=
723 Create_Itype (E_Subprogram_Type, Parent (T_Def));
726 if Nkind (T_Def) = N_Access_Function_Definition then
727 Analyze (Subtype_Mark (T_Def));
728 Set_Etype (Desig_Type, Entity (Subtype_Mark (T_Def)));
730 if not (Is_Type (Etype (Desig_Type))) then
732 ("expect type in function specification", Subtype_Mark (T_Def));
736 Set_Etype (Desig_Type, Standard_Void_Type);
739 if Present (Formals) then
740 New_Scope (Desig_Type);
741 Process_Formals (Formals, Parent (T_Def));
743 -- A bit of a kludge here, End_Scope requires that the parent
744 -- pointer be set to something reasonable, but Itypes don't
745 -- have parent pointers. So we set it and then unset it ???
746 -- If and when Itypes have proper parent pointers to their
747 -- declarations, this kludge can be removed.
749 Set_Parent (Desig_Type, T_Name);
751 Set_Parent (Desig_Type, Empty);
754 -- The return type and/or any parameter type may be incomplete. Mark
755 -- the subprogram_type as depending on the incomplete type, so that
756 -- it can be updated when the full type declaration is seen.
758 if Present (Formals) then
759 Formal := First_Formal (Desig_Type);
761 while Present (Formal) loop
763 if Ekind (Formal) /= E_In_Parameter
764 and then Nkind (T_Def) = N_Access_Function_Definition
766 Error_Msg_N ("functions can only have IN parameters", Formal);
769 if Ekind (Etype (Formal)) = E_Incomplete_Type then
770 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
771 Set_Has_Delayed_Freeze (Desig_Type);
774 Next_Formal (Formal);
778 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
779 and then not Has_Delayed_Freeze (Desig_Type)
781 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
782 Set_Has_Delayed_Freeze (Desig_Type);
785 Check_Delayed_Subprogram (Desig_Type);
787 if Protected_Present (T_Def) then
788 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
789 Set_Convention (Desig_Type, Convention_Protected);
791 Set_Ekind (T_Name, E_Access_Subprogram_Type);
794 Set_Etype (T_Name, T_Name);
795 Init_Size_Align (T_Name);
796 Set_Directly_Designated_Type (T_Name, Desig_Type);
798 Check_Restriction (No_Access_Subprograms, T_Def);
799 end Access_Subprogram_Declaration;
801 ----------------------------
802 -- Access_Type_Declaration --
803 ----------------------------
805 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
806 S : constant Node_Id := Subtype_Indication (Def);
807 P : constant Node_Id := Parent (Def);
813 -- Non-limited view, when needed
816 -- Check for permissible use of incomplete type
818 if Nkind (S) /= N_Subtype_Indication then
821 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
822 Set_Directly_Designated_Type (T, Entity (S));
824 Set_Directly_Designated_Type (T,
825 Process_Subtype (S, P, T, 'P'));
829 Set_Directly_Designated_Type (T,
830 Process_Subtype (S, P, T, 'P'));
833 if All_Present (Def) or Constant_Present (Def) then
834 Set_Ekind (T, E_General_Access_Type);
836 Set_Ekind (T, E_Access_Type);
839 if Base_Type (Designated_Type (T)) = T then
840 Error_Msg_N ("access type cannot designate itself", S);
845 -- If the type has appeared already in a with_type clause, it is
846 -- frozen and the pointer size is already set. Else, initialize.
848 if not From_With_Type (T) then
852 Set_Is_Access_Constant (T, Constant_Present (Def));
854 Desig := Designated_Type (T);
856 -- If designated type is an imported tagged type, indicate that the
857 -- access type is also imported, and therefore restricted in its use.
858 -- The access type may already be imported, so keep setting otherwise.
860 -- If the non-limited view of the designated type is available, use
861 -- it as the designated type of the access type, so that the back-end
862 -- gets a usable entity.
864 if From_With_Type (Desig) then
865 Set_From_With_Type (T);
867 if Ekind (Desig) = E_Incomplete_Type then
868 N_Desig := Non_Limited_View (Desig);
870 elsif Ekind (Desig) = E_Class_Wide_Type then
871 if From_With_Type (Etype (Desig)) then
872 N_Desig := Non_Limited_View (Etype (Desig));
874 N_Desig := Etype (Desig);
878 pragma Assert (False);
881 pragma Assert (Present (N_Desig));
882 Set_Directly_Designated_Type (T, N_Desig);
885 -- Note that Has_Task is always false, since the access type itself
886 -- is not a task type. See Einfo for more description on this point.
887 -- Exactly the same consideration applies to Has_Controlled_Component.
889 Set_Has_Task (T, False);
890 Set_Has_Controlled_Component (T, False);
891 end Access_Type_Declaration;
893 -----------------------------------
894 -- Analyze_Component_Declaration --
895 -----------------------------------
897 procedure Analyze_Component_Declaration (N : Node_Id) is
898 Id : constant Entity_Id := Defining_Identifier (N);
903 Generate_Definition (Id);
905 T := Find_Type_Of_Object (Subtype_Indication (N), N);
907 -- If the subtype is a constrained subtype of the enclosing record,
908 -- (which must have a partial view) the back-end does not handle
909 -- properly the recursion. Rewrite the component declaration with
910 -- an explicit subtype indication, which is acceptable to Gigi. We
911 -- can copy the tree directly because side effects have already been
912 -- removed from discriminant constraints.
914 if Ekind (T) = E_Access_Subtype
915 and then Is_Entity_Name (Subtype_Indication (N))
916 and then Comes_From_Source (T)
917 and then Nkind (Parent (T)) = N_Subtype_Declaration
918 and then Etype (Directly_Designated_Type (T)) = Current_Scope
921 (Subtype_Indication (N),
922 New_Copy_Tree (Subtype_Indication (Parent (T))));
923 T := Find_Type_Of_Object (Subtype_Indication (N), N);
926 -- If the component declaration includes a default expression, then we
927 -- check that the component is not of a limited type (RM 3.7(5)),
928 -- and do the special preanalysis of the expression (see section on
929 -- "Handling of Default and Per-Object Expressions" in the spec of
932 if Present (Expression (N)) then
933 Analyze_Per_Use_Expression (Expression (N), T);
934 Check_Initialization (T, Expression (N));
937 -- The parent type may be a private view with unknown discriminants,
938 -- and thus unconstrained. Regular components must be constrained.
940 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
942 ("unconstrained subtype in component declaration",
943 Subtype_Indication (N));
945 -- Components cannot be abstract, except for the special case of
946 -- the _Parent field (case of extending an abstract tagged type)
948 elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then
949 Error_Msg_N ("type of a component cannot be abstract", N);
953 Set_Is_Aliased (Id, Aliased_Present (N));
955 -- If the this component is private (or depends on a private type),
956 -- flag the record type to indicate that some operations are not
959 P := Private_Component (T);
962 -- Check for circular definitions.
965 Set_Etype (Id, Any_Type);
967 -- There is a gap in the visibility of operations only if the
968 -- component type is not defined in the scope of the record type.
970 elsif Scope (P) = Scope (Current_Scope) then
973 elsif Is_Limited_Type (P) then
974 Set_Is_Limited_Composite (Current_Scope);
977 Set_Is_Private_Composite (Current_Scope);
982 and then Is_Limited_Type (T)
983 and then Chars (Id) /= Name_uParent
984 and then Is_Tagged_Type (Current_Scope)
986 if Is_Derived_Type (Current_Scope)
987 and then not Is_Limited_Record (Root_Type (Current_Scope))
990 ("extension of nonlimited type cannot have limited components",
992 Explain_Limited_Type (T, N);
993 Set_Etype (Id, Any_Type);
994 Set_Is_Limited_Composite (Current_Scope, False);
996 elsif not Is_Derived_Type (Current_Scope)
997 and then not Is_Limited_Record (Current_Scope)
1000 ("nonlimited tagged type cannot have limited components", N);
1001 Explain_Limited_Type (T, N);
1002 Set_Etype (Id, Any_Type);
1003 Set_Is_Limited_Composite (Current_Scope, False);
1007 Set_Original_Record_Component (Id, Id);
1008 end Analyze_Component_Declaration;
1010 --------------------------
1011 -- Analyze_Declarations --
1012 --------------------------
1014 procedure Analyze_Declarations (L : List_Id) is
1016 Next_Node : Node_Id;
1017 Freeze_From : Entity_Id := Empty;
1020 -- Adjust D not to include implicit label declarations, since these
1021 -- have strange Sloc values that result in elaboration check problems.
1022 -- (They have the sloc of the label as found in the source, and that
1023 -- is ahead of the current declarative part).
1029 procedure Adjust_D is
1031 while Present (Prev (D))
1032 and then Nkind (D) = N_Implicit_Label_Declaration
1038 -- Start of processing for Analyze_Declarations
1042 while Present (D) loop
1044 -- Complete analysis of declaration
1047 Next_Node := Next (D);
1049 if No (Freeze_From) then
1050 Freeze_From := First_Entity (Current_Scope);
1053 -- At the end of a declarative part, freeze remaining entities
1054 -- declared in it. The end of the visible declarations of a
1055 -- package specification is not the end of a declarative part
1056 -- if private declarations are present. The end of a package
1057 -- declaration is a freezing point only if it a library package.
1058 -- A task definition or protected type definition is not a freeze
1059 -- point either. Finally, we do not freeze entities in generic
1060 -- scopes, because there is no code generated for them and freeze
1061 -- nodes will be generated for the instance.
1063 -- The end of a package instantiation is not a freeze point, but
1064 -- for now we make it one, because the generic body is inserted
1065 -- (currently) immediately after. Generic instantiations will not
1066 -- be a freeze point once delayed freezing of bodies is implemented.
1067 -- (This is needed in any case for early instantiations ???).
1069 if No (Next_Node) then
1070 if Nkind (Parent (L)) = N_Component_List
1071 or else Nkind (Parent (L)) = N_Task_Definition
1072 or else Nkind (Parent (L)) = N_Protected_Definition
1076 elsif Nkind (Parent (L)) /= N_Package_Specification then
1077 if Nkind (Parent (L)) = N_Package_Body then
1078 Freeze_From := First_Entity (Current_Scope);
1082 Freeze_All (Freeze_From, D);
1083 Freeze_From := Last_Entity (Current_Scope);
1085 elsif Scope (Current_Scope) /= Standard_Standard
1086 and then not Is_Child_Unit (Current_Scope)
1087 and then No (Generic_Parent (Parent (L)))
1091 elsif L /= Visible_Declarations (Parent (L))
1092 or else No (Private_Declarations (Parent (L)))
1093 or else Is_Empty_List (Private_Declarations (Parent (L)))
1096 Freeze_All (Freeze_From, D);
1097 Freeze_From := Last_Entity (Current_Scope);
1100 -- If next node is a body then freeze all types before the body.
1101 -- An exception occurs for expander generated bodies, which can
1102 -- be recognized by their already being analyzed. The expander
1103 -- ensures that all types needed by these bodies have been frozen
1104 -- but it is not necessary to freeze all types (and would be wrong
1105 -- since it would not correspond to an RM defined freeze point).
1107 elsif not Analyzed (Next_Node)
1108 and then (Nkind (Next_Node) = N_Subprogram_Body
1109 or else Nkind (Next_Node) = N_Entry_Body
1110 or else Nkind (Next_Node) = N_Package_Body
1111 or else Nkind (Next_Node) = N_Protected_Body
1112 or else Nkind (Next_Node) = N_Task_Body
1113 or else Nkind (Next_Node) in N_Body_Stub)
1116 Freeze_All (Freeze_From, D);
1117 Freeze_From := Last_Entity (Current_Scope);
1122 end Analyze_Declarations;
1124 ----------------------------------
1125 -- Analyze_Incomplete_Type_Decl --
1126 ----------------------------------
1128 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
1129 F : constant Boolean := Is_Pure (Current_Scope);
1133 Generate_Definition (Defining_Identifier (N));
1135 -- Process an incomplete declaration. The identifier must not have been
1136 -- declared already in the scope. However, an incomplete declaration may
1137 -- appear in the private part of a package, for a private type that has
1138 -- already been declared.
1140 -- In this case, the discriminants (if any) must match.
1142 T := Find_Type_Name (N);
1144 Set_Ekind (T, E_Incomplete_Type);
1145 Init_Size_Align (T);
1146 Set_Is_First_Subtype (T, True);
1150 Set_Stored_Constraint (T, No_Elist);
1152 if Present (Discriminant_Specifications (N)) then
1153 Process_Discriminants (N);
1158 -- If the type has discriminants, non-trivial subtypes may be
1159 -- be declared before the full view of the type. The full views
1160 -- of those subtypes will be built after the full view of the type.
1162 Set_Private_Dependents (T, New_Elmt_List);
1164 end Analyze_Incomplete_Type_Decl;
1166 -----------------------------
1167 -- Analyze_Itype_Reference --
1168 -----------------------------
1170 -- Nothing to do. This node is placed in the tree only for the benefit
1171 -- of Gigi processing, and has no effect on the semantic processing.
1173 procedure Analyze_Itype_Reference (N : Node_Id) is
1175 pragma Assert (Is_Itype (Itype (N)));
1177 end Analyze_Itype_Reference;
1179 --------------------------------
1180 -- Analyze_Number_Declaration --
1181 --------------------------------
1183 procedure Analyze_Number_Declaration (N : Node_Id) is
1184 Id : constant Entity_Id := Defining_Identifier (N);
1185 E : constant Node_Id := Expression (N);
1187 Index : Interp_Index;
1191 Generate_Definition (Id);
1194 -- This is an optimization of a common case of an integer literal
1196 if Nkind (E) = N_Integer_Literal then
1197 Set_Is_Static_Expression (E, True);
1198 Set_Etype (E, Universal_Integer);
1200 Set_Etype (Id, Universal_Integer);
1201 Set_Ekind (Id, E_Named_Integer);
1202 Set_Is_Frozen (Id, True);
1206 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1208 -- Process expression, replacing error by integer zero, to avoid
1209 -- cascaded errors or aborts further along in the processing
1211 -- Replace Error by integer zero, which seems least likely to
1212 -- cause cascaded errors.
1215 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
1216 Set_Error_Posted (E);
1221 -- Verify that the expression is static and numeric. If
1222 -- the expression is overloaded, we apply the preference
1223 -- rule that favors root numeric types.
1225 if not Is_Overloaded (E) then
1230 Get_First_Interp (E, Index, It);
1232 while Present (It.Typ) loop
1233 if (Is_Integer_Type (It.Typ)
1234 or else Is_Real_Type (It.Typ))
1235 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
1237 if T = Any_Type then
1240 elsif It.Typ = Universal_Real
1241 or else It.Typ = Universal_Integer
1243 -- Choose universal interpretation over any other.
1250 Get_Next_Interp (Index, It);
1254 if Is_Integer_Type (T) then
1256 Set_Etype (Id, Universal_Integer);
1257 Set_Ekind (Id, E_Named_Integer);
1259 elsif Is_Real_Type (T) then
1261 -- Because the real value is converted to universal_real, this
1262 -- is a legal context for a universal fixed expression.
1264 if T = Universal_Fixed then
1266 Loc : constant Source_Ptr := Sloc (N);
1267 Conv : constant Node_Id := Make_Type_Conversion (Loc,
1269 New_Occurrence_Of (Universal_Real, Loc),
1270 Expression => Relocate_Node (E));
1277 elsif T = Any_Fixed then
1278 Error_Msg_N ("illegal context for mixed mode operation", E);
1280 -- Expression is of the form : universal_fixed * integer.
1281 -- Try to resolve as universal_real.
1283 T := Universal_Real;
1288 Set_Etype (Id, Universal_Real);
1289 Set_Ekind (Id, E_Named_Real);
1292 Wrong_Type (E, Any_Numeric);
1296 Set_Ekind (Id, E_Constant);
1297 Set_Never_Set_In_Source (Id, True);
1298 Set_Is_True_Constant (Id, True);
1302 if Nkind (E) = N_Integer_Literal
1303 or else Nkind (E) = N_Real_Literal
1305 Set_Etype (E, Etype (Id));
1308 if not Is_OK_Static_Expression (E) then
1309 Flag_Non_Static_Expr
1310 ("non-static expression used in number declaration!", E);
1311 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
1312 Set_Etype (E, Any_Type);
1314 end Analyze_Number_Declaration;
1316 --------------------------------
1317 -- Analyze_Object_Declaration --
1318 --------------------------------
1320 procedure Analyze_Object_Declaration (N : Node_Id) is
1321 Loc : constant Source_Ptr := Sloc (N);
1322 Id : constant Entity_Id := Defining_Identifier (N);
1326 E : Node_Id := Expression (N);
1327 -- E is set to Expression (N) throughout this routine. When
1328 -- Expression (N) is modified, E is changed accordingly.
1330 Prev_Entity : Entity_Id := Empty;
1332 function Build_Default_Subtype return Entity_Id;
1333 -- If the object is limited or aliased, and if the type is unconstrained
1334 -- and there is no expression, the discriminants cannot be modified and
1335 -- the subtype of the object is constrained by the defaults, so it is
1336 -- worthile building the corresponding subtype.
1338 ---------------------------
1339 -- Build_Default_Subtype --
1340 ---------------------------
1342 function Build_Default_Subtype return Entity_Id is
1343 Constraints : constant List_Id := New_List;
1349 Disc := First_Discriminant (T);
1351 if No (Discriminant_Default_Value (Disc)) then
1352 return T; -- previous error.
1355 Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
1356 while Present (Disc) loop
1359 Discriminant_Default_Value (Disc)), Constraints);
1360 Next_Discriminant (Disc);
1364 Make_Subtype_Declaration (Loc,
1365 Defining_Identifier => Act,
1366 Subtype_Indication =>
1367 Make_Subtype_Indication (Loc,
1368 Subtype_Mark => New_Occurrence_Of (T, Loc),
1370 Make_Index_Or_Discriminant_Constraint
1371 (Loc, Constraints)));
1373 Insert_Before (N, Decl);
1376 end Build_Default_Subtype;
1378 -- Start of processing for Analyze_Object_Declaration
1381 -- There are three kinds of implicit types generated by an
1382 -- object declaration:
1384 -- 1. Those for generated by the original Object Definition
1386 -- 2. Those generated by the Expression
1388 -- 3. Those used to constrained the Object Definition with the
1389 -- expression constraints when it is unconstrained
1391 -- They must be generated in this order to avoid order of elaboration
1392 -- issues. Thus the first step (after entering the name) is to analyze
1393 -- the object definition.
1395 if Constant_Present (N) then
1396 Prev_Entity := Current_Entity_In_Scope (Id);
1398 -- If homograph is an implicit subprogram, it is overridden by the
1399 -- current declaration.
1401 if Present (Prev_Entity)
1402 and then Is_Overloadable (Prev_Entity)
1403 and then Is_Inherited_Operation (Prev_Entity)
1405 Prev_Entity := Empty;
1409 if Present (Prev_Entity) then
1410 Constant_Redeclaration (Id, N, T);
1412 Generate_Reference (Prev_Entity, Id, 'c');
1413 Set_Completion_Referenced (Id);
1415 if Error_Posted (N) then
1416 -- Type mismatch or illegal redeclaration, Do not analyze
1417 -- expression to avoid cascaded errors.
1419 T := Find_Type_Of_Object (Object_Definition (N), N);
1421 Set_Ekind (Id, E_Variable);
1425 -- In the normal case, enter identifier at the start to catch
1426 -- premature usage in the initialization expression.
1429 Generate_Definition (Id);
1432 T := Find_Type_Of_Object (Object_Definition (N), N);
1434 if Error_Posted (Id) then
1436 Set_Ekind (Id, E_Variable);
1441 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1443 -- If deferred constant, make sure context is appropriate. We detect
1444 -- a deferred constant as a constant declaration with no expression.
1445 -- A deferred constant can appear in a package body if its completion
1446 -- is by means of an interface pragma.
1448 if Constant_Present (N)
1451 if not Is_Package (Current_Scope) then
1453 ("invalid context for deferred constant declaration ('R'M 7.4)",
1456 ("\declaration requires an initialization expression",
1458 Set_Constant_Present (N, False);
1460 -- In Ada 83, deferred constant must be of private type
1462 elsif not Is_Private_Type (T) then
1463 if Ada_83 and then Comes_From_Source (N) then
1465 ("(Ada 83) deferred constant must be private type", N);
1469 -- If not a deferred constant, then object declaration freezes its type
1472 Check_Fully_Declared (T, N);
1473 Freeze_Before (N, T);
1476 -- If the object was created by a constrained array definition, then
1477 -- set the link in both the anonymous base type and anonymous subtype
1478 -- that are built to represent the array type to point to the object.
1480 if Nkind (Object_Definition (Declaration_Node (Id))) =
1481 N_Constrained_Array_Definition
1483 Set_Related_Array_Object (T, Id);
1484 Set_Related_Array_Object (Base_Type (T), Id);
1487 -- Special checks for protected objects not at library level
1489 if Is_Protected_Type (T)
1490 and then not Is_Library_Level_Entity (Id)
1492 Check_Restriction (No_Local_Protected_Objects, Id);
1494 -- Protected objects with interrupt handlers must be at library level
1496 if Has_Interrupt_Handler (T) then
1498 ("interrupt object can only be declared at library level", Id);
1502 -- The actual subtype of the object is the nominal subtype, unless
1503 -- the nominal one is unconstrained and obtained from the expression.
1507 -- Process initialization expression if present and not in error
1509 if Present (E) and then E /= Error then
1512 -- If an initialization expression is present, then we set the
1513 -- Is_True_Constant flag. It will be reset if this is a variable
1514 -- and it is indeed modified.
1516 Set_Is_True_Constant (Id, True);
1518 if not Assignment_OK (N) then
1519 Check_Initialization (T, E);
1522 Set_Etype (Id, T); -- may be overridden later on.
1524 Check_Unset_Reference (E);
1526 if Compile_Time_Known_Value (E) then
1527 Set_Current_Value (Id, E);
1530 -- Check incorrect use of dynamically tagged expressions. Note
1531 -- the use of Is_Tagged_Type (T) which seems redundant but is in
1532 -- fact important to avoid spurious errors due to expanded code
1533 -- for dispatching functions over an anonymous access type
1535 if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
1536 and then Is_Tagged_Type (T)
1537 and then not Is_Class_Wide_Type (T)
1539 Error_Msg_N ("dynamically tagged expression not allowed!", E);
1542 Apply_Scalar_Range_Check (E, T);
1543 Apply_Static_Length_Check (E, T);
1546 -- Abstract type is never permitted for a variable or constant.
1547 -- Note: we inhibit this check for objects that do not come from
1548 -- source because there is at least one case (the expansion of
1549 -- x'class'input where x is abstract) where we legitimately
1550 -- generate an abstract object.
1552 if Is_Abstract (T) and then Comes_From_Source (N) then
1553 Error_Msg_N ("type of object cannot be abstract",
1554 Object_Definition (N));
1555 if Is_CPP_Class (T) then
1556 Error_Msg_NE ("\} may need a cpp_constructor",
1557 Object_Definition (N), T);
1560 -- Case of unconstrained type
1562 elsif Is_Indefinite_Subtype (T) then
1564 -- Nothing to do in deferred constant case
1566 if Constant_Present (N) and then No (E) then
1569 -- Case of no initialization present
1572 if No_Initialization (N) then
1575 elsif Is_Class_Wide_Type (T) then
1577 ("initialization required in class-wide declaration ", N);
1581 ("unconstrained subtype not allowed (need initialization)",
1582 Object_Definition (N));
1585 -- Case of initialization present but in error. Set initial
1586 -- expression as absent (but do not make above complaints)
1588 elsif E = Error then
1589 Set_Expression (N, Empty);
1592 -- Case of initialization present
1595 -- Not allowed in Ada 83
1597 if not Constant_Present (N) then
1599 and then Comes_From_Source (Object_Definition (N))
1602 ("(Ada 83) unconstrained variable not allowed",
1603 Object_Definition (N));
1607 -- Now we constrain the variable from the initializing expression
1609 -- If the expression is an aggregate, it has been expanded into
1610 -- individual assignments. Retrieve the actual type from the
1611 -- expanded construct.
1613 if Is_Array_Type (T)
1614 and then No_Initialization (N)
1615 and then Nkind (Original_Node (E)) = N_Aggregate
1620 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
1621 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
1624 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
1626 if Aliased_Present (N) then
1627 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1630 Freeze_Before (N, Act_T);
1631 Freeze_Before (N, T);
1634 elsif Is_Array_Type (T)
1635 and then No_Initialization (N)
1636 and then Nkind (Original_Node (E)) = N_Aggregate
1638 if not Is_Entity_Name (Object_Definition (N)) then
1640 Check_Compile_Time_Size (Act_T);
1642 if Aliased_Present (N) then
1643 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1647 -- When the given object definition and the aggregate are specified
1648 -- independently, and their lengths might differ do a length check.
1649 -- This cannot happen if the aggregate is of the form (others =>...)
1651 if not Is_Constrained (T) then
1654 elsif Nkind (E) = N_Raise_Constraint_Error then
1656 -- Aggregate is statically illegal. Place back in declaration
1658 Set_Expression (N, E);
1659 Set_No_Initialization (N, False);
1661 elsif T = Etype (E) then
1664 elsif Nkind (E) = N_Aggregate
1665 and then Present (Component_Associations (E))
1666 and then Present (Choices (First (Component_Associations (E))))
1667 and then Nkind (First
1668 (Choices (First (Component_Associations (E))))) = N_Others_Choice
1673 Apply_Length_Check (E, T);
1676 elsif (Is_Limited_Record (T)
1677 or else Is_Concurrent_Type (T))
1678 and then not Is_Constrained (T)
1679 and then Has_Discriminants (T)
1681 Act_T := Build_Default_Subtype;
1682 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
1684 elsif not Is_Constrained (T)
1685 and then Has_Discriminants (T)
1686 and then Constant_Present (N)
1687 and then Nkind (E) = N_Function_Call
1689 -- The back-end has problems with constants of a discriminated type
1690 -- with defaults, if the initial value is a function call. We
1691 -- generate an intermediate temporary for the result of the call.
1692 -- It is unclear why this should make it acceptable to gcc. ???
1694 Remove_Side_Effects (E);
1697 if T = Standard_Wide_Character
1698 or else Root_Type (T) = Standard_Wide_String
1700 Check_Restriction (No_Wide_Characters, Object_Definition (N));
1703 -- Now establish the proper kind and type of the object
1705 if Constant_Present (N) then
1706 Set_Ekind (Id, E_Constant);
1707 Set_Never_Set_In_Source (Id, True);
1708 Set_Is_True_Constant (Id, True);
1711 Set_Ekind (Id, E_Variable);
1713 -- A variable is set as shared passive if it appears in a shared
1714 -- passive package, and is at the outer level. This is not done
1715 -- for entities generated during expansion, because those are
1716 -- always manipulated locally.
1718 if Is_Shared_Passive (Current_Scope)
1719 and then Is_Library_Level_Entity (Id)
1720 and then Comes_From_Source (Id)
1722 Set_Is_Shared_Passive (Id);
1723 Check_Shared_Var (Id, T, N);
1726 -- Case of no initializing expression present. If the type is not
1727 -- fully initialized, then we set Never_Set_In_Source, since this
1728 -- is a case of a potentially uninitialized object. Note that we
1729 -- do not consider access variables to be fully initialized for
1730 -- this purpose, since it still seems dubious if someone declares
1732 -- Note that we only do this for source declarations. If the object
1733 -- is declared by a generated declaration, we assume that it is not
1734 -- appropriate to generate warnings in that case.
1737 if (Is_Access_Type (T)
1738 or else not Is_Fully_Initialized_Type (T))
1739 and then Comes_From_Source (N)
1741 Set_Never_Set_In_Source (Id);
1746 Init_Alignment (Id);
1749 if Aliased_Present (N) then
1750 Set_Is_Aliased (Id);
1753 and then Is_Record_Type (T)
1754 and then not Is_Constrained (T)
1755 and then Has_Discriminants (T)
1757 Set_Actual_Subtype (Id, Build_Default_Subtype);
1761 Set_Etype (Id, Act_T);
1763 if Has_Controlled_Component (Etype (Id))
1764 or else Is_Controlled (Etype (Id))
1766 if not Is_Library_Level_Entity (Id) then
1767 Check_Restriction (No_Nested_Finalization, N);
1770 Validate_Controlled_Object (Id);
1773 -- Generate a warning when an initialization causes an obvious
1774 -- ABE violation. If the init expression is a simple aggregate
1775 -- there shouldn't be any initialize/adjust call generated. This
1776 -- will be true as soon as aggregates are built in place when
1777 -- possible. ??? at the moment we do not generate warnings for
1778 -- temporaries created for those aggregates although a
1779 -- Program_Error might be generated if compiled with -gnato
1781 if Is_Controlled (Etype (Id))
1782 and then Comes_From_Source (Id)
1785 BT : constant Entity_Id := Base_Type (Etype (Id));
1787 Implicit_Call : Entity_Id;
1788 pragma Warnings (Off, Implicit_Call);
1789 -- What is this about, it is never referenced ???
1791 function Is_Aggr (N : Node_Id) return Boolean;
1792 -- Check that N is an aggregate
1798 function Is_Aggr (N : Node_Id) return Boolean is
1800 case Nkind (Original_Node (N)) is
1801 when N_Aggregate | N_Extension_Aggregate =>
1804 when N_Qualified_Expression |
1806 N_Unchecked_Type_Conversion =>
1807 return Is_Aggr (Expression (Original_Node (N)));
1815 -- If no underlying type, we already are in an error situation
1816 -- don't try to add a warning since we do not have access
1819 if No (Underlying_Type (BT)) then
1820 Implicit_Call := Empty;
1822 -- A generic type does not have usable primitive operators.
1823 -- Initialization calls are built for instances.
1825 elsif Is_Generic_Type (BT) then
1826 Implicit_Call := Empty;
1828 -- if the init expression is not an aggregate, an adjust
1829 -- call will be generated
1831 elsif Present (E) and then not Is_Aggr (E) then
1832 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
1834 -- if no init expression and we are not in the deferred
1835 -- constant case, an Initialize call will be generated
1837 elsif No (E) and then not Constant_Present (N) then
1838 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
1841 Implicit_Call := Empty;
1847 if Has_Task (Etype (Id)) then
1848 Check_Restriction (Max_Tasks, N);
1850 if not Is_Library_Level_Entity (Id) then
1851 Check_Restriction (No_Task_Hierarchy, N);
1852 Check_Potentially_Blocking_Operation (N);
1855 -- A rather specialized test. If we see two tasks being declared
1856 -- of the same type in the same object declaration, and the task
1857 -- has an entry with an address clause, we know that program error
1858 -- will be raised at run-time since we can't have two tasks with
1859 -- entries at the same address.
1861 if Is_Task_Type (Etype (Id))
1862 and then More_Ids (N)
1868 E := First_Entity (Etype (Id));
1869 while Present (E) loop
1870 if Ekind (E) = E_Entry
1871 and then Present (Get_Attribute_Definition_Clause
1872 (E, Attribute_Address))
1875 ("?more than one task with same entry address", N);
1877 ("\?Program_Error will be raised at run time", N);
1879 Make_Raise_Program_Error (Loc,
1880 Reason => PE_Duplicated_Entry_Address));
1890 -- Some simple constant-propagation: if the expression is a constant
1891 -- string initialized with a literal, share the literal. This avoids
1895 and then Is_Entity_Name (E)
1896 and then Ekind (Entity (E)) = E_Constant
1897 and then Base_Type (Etype (E)) = Standard_String
1900 Val : constant Node_Id := Constant_Value (Entity (E));
1904 and then Nkind (Val) = N_String_Literal
1906 Rewrite (E, New_Copy (Val));
1911 -- Another optimization: if the nominal subtype is unconstrained and
1912 -- the expression is a function call that returns an unconstrained
1913 -- type, rewrite the declaration as a renaming of the result of the
1914 -- call. The exceptions below are cases where the copy is expected,
1915 -- either by the back end (Aliased case) or by the semantics, as for
1916 -- initializing controlled types or copying tags for classwide types.
1919 and then Nkind (E) = N_Explicit_Dereference
1920 and then Nkind (Original_Node (E)) = N_Function_Call
1921 and then not Is_Library_Level_Entity (Id)
1922 and then not Is_Constrained (T)
1923 and then not Is_Aliased (Id)
1924 and then not Is_Class_Wide_Type (T)
1925 and then not Is_Controlled (T)
1926 and then not Has_Controlled_Component (Base_Type (T))
1927 and then Expander_Active
1930 Make_Object_Renaming_Declaration (Loc,
1931 Defining_Identifier => Id,
1932 Subtype_Mark => New_Occurrence_Of
1933 (Base_Type (Etype (Id)), Loc),
1936 Set_Renamed_Object (Id, E);
1938 -- Force generation of debugging information for the constant
1939 -- and for the renamed function call.
1941 Set_Needs_Debug_Info (Id);
1942 Set_Needs_Debug_Info (Entity (Prefix (E)));
1945 if Present (Prev_Entity)
1946 and then Is_Frozen (Prev_Entity)
1947 and then not Error_Posted (Id)
1949 Error_Msg_N ("full constant declaration appears too late", N);
1952 Check_Eliminated (Id);
1953 end Analyze_Object_Declaration;
1955 ---------------------------
1956 -- Analyze_Others_Choice --
1957 ---------------------------
1959 -- Nothing to do for the others choice node itself, the semantic analysis
1960 -- of the others choice will occur as part of the processing of the parent
1962 procedure Analyze_Others_Choice (N : Node_Id) is
1963 pragma Warnings (Off, N);
1967 end Analyze_Others_Choice;
1969 --------------------------------
1970 -- Analyze_Per_Use_Expression --
1971 --------------------------------
1973 procedure Analyze_Per_Use_Expression (N : Node_Id; T : Entity_Id) is
1974 Save_In_Default_Expression : constant Boolean := In_Default_Expression;
1977 In_Default_Expression := True;
1978 Pre_Analyze_And_Resolve (N, T);
1979 In_Default_Expression := Save_In_Default_Expression;
1980 end Analyze_Per_Use_Expression;
1982 -------------------------------------------
1983 -- Analyze_Private_Extension_Declaration --
1984 -------------------------------------------
1986 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
1987 T : constant Entity_Id := Defining_Identifier (N);
1988 Indic : constant Node_Id := Subtype_Indication (N);
1989 Parent_Type : Entity_Id;
1990 Parent_Base : Entity_Id;
1993 Generate_Definition (T);
1996 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
1997 Parent_Base := Base_Type (Parent_Type);
1999 if Parent_Type = Any_Type
2000 or else Etype (Parent_Type) = Any_Type
2002 Set_Ekind (T, Ekind (Parent_Type));
2003 Set_Etype (T, Any_Type);
2006 elsif not Is_Tagged_Type (Parent_Type) then
2008 ("parent of type extension must be a tagged type ", Indic);
2011 elsif Ekind (Parent_Type) = E_Void
2012 or else Ekind (Parent_Type) = E_Incomplete_Type
2014 Error_Msg_N ("premature derivation of incomplete type", Indic);
2018 -- Perhaps the parent type should be changed to the class-wide type's
2019 -- specific type in this case to prevent cascading errors ???
2021 if Is_Class_Wide_Type (Parent_Type) then
2023 ("parent of type extension must not be a class-wide type", Indic);
2027 if (not Is_Package (Current_Scope)
2028 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
2029 or else In_Private_Part (Current_Scope)
2032 Error_Msg_N ("invalid context for private extension", N);
2035 -- Set common attributes
2037 Set_Is_Pure (T, Is_Pure (Current_Scope));
2038 Set_Scope (T, Current_Scope);
2039 Set_Ekind (T, E_Record_Type_With_Private);
2040 Init_Size_Align (T);
2042 Set_Etype (T, Parent_Base);
2043 Set_Has_Task (T, Has_Task (Parent_Base));
2045 Set_Convention (T, Convention (Parent_Type));
2046 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
2047 Set_Is_First_Subtype (T);
2048 Make_Class_Wide_Type (T);
2050 Build_Derived_Record_Type (N, Parent_Type, T);
2051 end Analyze_Private_Extension_Declaration;
2053 ---------------------------------
2054 -- Analyze_Subtype_Declaration --
2055 ---------------------------------
2057 procedure Analyze_Subtype_Declaration (N : Node_Id) is
2058 Id : constant Entity_Id := Defining_Identifier (N);
2060 R_Checks : Check_Result;
2063 Generate_Definition (Id);
2064 Set_Is_Pure (Id, Is_Pure (Current_Scope));
2065 Init_Size_Align (Id);
2067 -- The following guard condition on Enter_Name is to handle cases
2068 -- where the defining identifier has already been entered into the
2069 -- scope but the declaration as a whole needs to be analyzed.
2071 -- This case in particular happens for derived enumeration types.
2072 -- The derived enumeration type is processed as an inserted enumeration
2073 -- type declaration followed by a rewritten subtype declaration. The
2074 -- defining identifier, however, is entered into the name scope very
2075 -- early in the processing of the original type declaration and
2076 -- therefore needs to be avoided here, when the created subtype
2077 -- declaration is analyzed. (See Build_Derived_Types)
2079 -- This also happens when the full view of a private type is a
2080 -- derived type with constraints. In this case the entity has been
2081 -- introduced in the private declaration.
2083 if Present (Etype (Id))
2084 and then (Is_Private_Type (Etype (Id))
2085 or else Is_Task_Type (Etype (Id))
2086 or else Is_Rewrite_Substitution (N))
2094 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
2096 -- Inherit common attributes
2098 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
2099 Set_Is_Volatile (Id, Is_Volatile (T));
2100 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
2101 Set_Is_Atomic (Id, Is_Atomic (T));
2103 -- In the case where there is no constraint given in the subtype
2104 -- indication, Process_Subtype just returns the Subtype_Mark,
2105 -- so its semantic attributes must be established here.
2107 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
2108 Set_Etype (Id, Base_Type (T));
2112 Set_Ekind (Id, E_Array_Subtype);
2114 -- Shouldn't we call Copy_Array_Subtype_Attributes here???
2116 Set_First_Index (Id, First_Index (T));
2117 Set_Is_Aliased (Id, Is_Aliased (T));
2118 Set_Is_Constrained (Id, Is_Constrained (T));
2120 when Decimal_Fixed_Point_Kind =>
2121 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
2122 Set_Digits_Value (Id, Digits_Value (T));
2123 Set_Delta_Value (Id, Delta_Value (T));
2124 Set_Scale_Value (Id, Scale_Value (T));
2125 Set_Small_Value (Id, Small_Value (T));
2126 Set_Scalar_Range (Id, Scalar_Range (T));
2127 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
2128 Set_Is_Constrained (Id, Is_Constrained (T));
2129 Set_RM_Size (Id, RM_Size (T));
2131 when Enumeration_Kind =>
2132 Set_Ekind (Id, E_Enumeration_Subtype);
2133 Set_First_Literal (Id, First_Literal (Base_Type (T)));
2134 Set_Scalar_Range (Id, Scalar_Range (T));
2135 Set_Is_Character_Type (Id, Is_Character_Type (T));
2136 Set_Is_Constrained (Id, Is_Constrained (T));
2137 Set_RM_Size (Id, RM_Size (T));
2139 when Ordinary_Fixed_Point_Kind =>
2140 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
2141 Set_Scalar_Range (Id, Scalar_Range (T));
2142 Set_Small_Value (Id, Small_Value (T));
2143 Set_Delta_Value (Id, Delta_Value (T));
2144 Set_Is_Constrained (Id, Is_Constrained (T));
2145 Set_RM_Size (Id, RM_Size (T));
2148 Set_Ekind (Id, E_Floating_Point_Subtype);
2149 Set_Scalar_Range (Id, Scalar_Range (T));
2150 Set_Digits_Value (Id, Digits_Value (T));
2151 Set_Is_Constrained (Id, Is_Constrained (T));
2153 when Signed_Integer_Kind =>
2154 Set_Ekind (Id, E_Signed_Integer_Subtype);
2155 Set_Scalar_Range (Id, Scalar_Range (T));
2156 Set_Is_Constrained (Id, Is_Constrained (T));
2157 Set_RM_Size (Id, RM_Size (T));
2159 when Modular_Integer_Kind =>
2160 Set_Ekind (Id, E_Modular_Integer_Subtype);
2161 Set_Scalar_Range (Id, Scalar_Range (T));
2162 Set_Is_Constrained (Id, Is_Constrained (T));
2163 Set_RM_Size (Id, RM_Size (T));
2165 when Class_Wide_Kind =>
2166 Set_Ekind (Id, E_Class_Wide_Subtype);
2167 Set_First_Entity (Id, First_Entity (T));
2168 Set_Last_Entity (Id, Last_Entity (T));
2169 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2170 Set_Cloned_Subtype (Id, T);
2171 Set_Is_Tagged_Type (Id, True);
2172 Set_Has_Unknown_Discriminants
2175 if Ekind (T) = E_Class_Wide_Subtype then
2176 Set_Equivalent_Type (Id, Equivalent_Type (T));
2179 when E_Record_Type | E_Record_Subtype =>
2180 Set_Ekind (Id, E_Record_Subtype);
2182 if Ekind (T) = E_Record_Subtype
2183 and then Present (Cloned_Subtype (T))
2185 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
2187 Set_Cloned_Subtype (Id, T);
2190 Set_First_Entity (Id, First_Entity (T));
2191 Set_Last_Entity (Id, Last_Entity (T));
2192 Set_Has_Discriminants (Id, Has_Discriminants (T));
2193 Set_Is_Constrained (Id, Is_Constrained (T));
2194 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2195 Set_Has_Unknown_Discriminants
2196 (Id, Has_Unknown_Discriminants (T));
2198 if Has_Discriminants (T) then
2199 Set_Discriminant_Constraint
2200 (Id, Discriminant_Constraint (T));
2201 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2203 elsif Has_Unknown_Discriminants (Id) then
2204 Set_Discriminant_Constraint (Id, No_Elist);
2207 if Is_Tagged_Type (T) then
2208 Set_Is_Tagged_Type (Id);
2209 Set_Is_Abstract (Id, Is_Abstract (T));
2210 Set_Primitive_Operations
2211 (Id, Primitive_Operations (T));
2212 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2215 when Private_Kind =>
2216 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2217 Set_Has_Discriminants (Id, Has_Discriminants (T));
2218 Set_Is_Constrained (Id, Is_Constrained (T));
2219 Set_First_Entity (Id, First_Entity (T));
2220 Set_Last_Entity (Id, Last_Entity (T));
2221 Set_Private_Dependents (Id, New_Elmt_List);
2222 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2223 Set_Has_Unknown_Discriminants
2224 (Id, Has_Unknown_Discriminants (T));
2226 if Is_Tagged_Type (T) then
2227 Set_Is_Tagged_Type (Id);
2228 Set_Is_Abstract (Id, Is_Abstract (T));
2229 Set_Primitive_Operations
2230 (Id, Primitive_Operations (T));
2231 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2234 -- In general the attributes of the subtype of a private
2235 -- type are the attributes of the partial view of parent.
2236 -- However, the full view may be a discriminated type,
2237 -- and the subtype must share the discriminant constraint
2238 -- to generate correct calls to initialization procedures.
2240 if Has_Discriminants (T) then
2241 Set_Discriminant_Constraint
2242 (Id, Discriminant_Constraint (T));
2243 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2245 elsif Present (Full_View (T))
2246 and then Has_Discriminants (Full_View (T))
2248 Set_Discriminant_Constraint
2249 (Id, Discriminant_Constraint (Full_View (T)));
2250 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2252 -- This would seem semantically correct, but apparently
2253 -- confuses the back-end (4412-009). To be explained ???
2255 -- Set_Has_Discriminants (Id);
2258 Prepare_Private_Subtype_Completion (Id, N);
2261 Set_Ekind (Id, E_Access_Subtype);
2262 Set_Is_Constrained (Id, Is_Constrained (T));
2263 Set_Is_Access_Constant
2264 (Id, Is_Access_Constant (T));
2265 Set_Directly_Designated_Type
2266 (Id, Designated_Type (T));
2268 -- A Pure library_item must not contain the declaration of a
2269 -- named access type, except within a subprogram, generic
2270 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
2272 if Comes_From_Source (Id)
2273 and then In_Pure_Unit
2274 and then not In_Subprogram_Task_Protected_Unit
2277 ("named access types not allowed in pure unit", N);
2280 when Concurrent_Kind =>
2281 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2282 Set_Corresponding_Record_Type (Id,
2283 Corresponding_Record_Type (T));
2284 Set_First_Entity (Id, First_Entity (T));
2285 Set_First_Private_Entity (Id, First_Private_Entity (T));
2286 Set_Has_Discriminants (Id, Has_Discriminants (T));
2287 Set_Is_Constrained (Id, Is_Constrained (T));
2288 Set_Last_Entity (Id, Last_Entity (T));
2290 if Has_Discriminants (T) then
2291 Set_Discriminant_Constraint (Id,
2292 Discriminant_Constraint (T));
2293 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2296 -- If the subtype name denotes an incomplete type
2297 -- an error was already reported by Process_Subtype.
2299 when E_Incomplete_Type =>
2300 Set_Etype (Id, Any_Type);
2303 raise Program_Error;
2307 if Etype (Id) = Any_Type then
2311 -- Some common processing on all types
2313 Set_Size_Info (Id, T);
2314 Set_First_Rep_Item (Id, First_Rep_Item (T));
2318 Set_Is_Immediately_Visible (Id, True);
2319 Set_Depends_On_Private (Id, Has_Private_Component (T));
2321 if Present (Generic_Parent_Type (N))
2324 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
2326 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
2327 /= N_Formal_Private_Type_Definition)
2329 if Is_Tagged_Type (Id) then
2330 if Is_Class_Wide_Type (Id) then
2331 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
2333 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
2336 elsif Scope (Etype (Id)) /= Standard_Standard then
2337 Derive_Subprograms (Generic_Parent_Type (N), Id);
2341 if Is_Private_Type (T)
2342 and then Present (Full_View (T))
2344 Conditional_Delay (Id, Full_View (T));
2346 -- The subtypes of components or subcomponents of protected types
2347 -- do not need freeze nodes, which would otherwise appear in the
2348 -- wrong scope (before the freeze node for the protected type). The
2349 -- proper subtypes are those of the subcomponents of the corresponding
2352 elsif Ekind (Scope (Id)) /= E_Protected_Type
2353 and then Present (Scope (Scope (Id))) -- error defense!
2354 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
2356 Conditional_Delay (Id, T);
2359 -- Check that constraint_error is raised for a scalar subtype
2360 -- indication when the lower or upper bound of a non-null range
2361 -- lies outside the range of the type mark.
2363 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
2364 if Is_Scalar_Type (Etype (Id))
2365 and then Scalar_Range (Id) /=
2366 Scalar_Range (Etype (Subtype_Mark
2367 (Subtype_Indication (N))))
2371 Etype (Subtype_Mark (Subtype_Indication (N))));
2373 elsif Is_Array_Type (Etype (Id))
2374 and then Present (First_Index (Id))
2376 -- This really should be a subprogram that finds the indications
2379 if ((Nkind (First_Index (Id)) = N_Identifier
2380 and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
2381 or else Nkind (First_Index (Id)) = N_Subtype_Indication)
2383 Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
2386 Target_Typ : constant Entity_Id :=
2389 (Subtype_Mark (Subtype_Indication (N)))));
2393 (Scalar_Range (Etype (First_Index (Id))),
2395 Etype (First_Index (Id)),
2396 Defining_Identifier (N));
2402 Sloc (Defining_Identifier (N)));
2408 Check_Eliminated (Id);
2409 end Analyze_Subtype_Declaration;
2411 --------------------------------
2412 -- Analyze_Subtype_Indication --
2413 --------------------------------
2415 procedure Analyze_Subtype_Indication (N : Node_Id) is
2416 T : constant Entity_Id := Subtype_Mark (N);
2417 R : constant Node_Id := Range_Expression (Constraint (N));
2424 Set_Etype (N, Etype (R));
2426 Set_Error_Posted (R);
2427 Set_Error_Posted (T);
2429 end Analyze_Subtype_Indication;
2431 ------------------------------
2432 -- Analyze_Type_Declaration --
2433 ------------------------------
2435 procedure Analyze_Type_Declaration (N : Node_Id) is
2436 Def : constant Node_Id := Type_Definition (N);
2437 Def_Id : constant Entity_Id := Defining_Identifier (N);
2441 Is_Remote : constant Boolean :=
2442 (Is_Remote_Types (Current_Scope)
2443 or else Is_Remote_Call_Interface (Current_Scope))
2444 and then not (In_Private_Part (Current_Scope)
2446 In_Package_Body (Current_Scope));
2449 Prev := Find_Type_Name (N);
2451 -- The full view, if present, now points to the current type. If the
2452 -- type was previously decorated when imported through a LIMITED WITH
2453 -- clause, it appears as incomplete but has no full view.
2455 if Ekind (Prev) = E_Incomplete_Type
2456 and then Present (Full_View (Prev))
2458 T := Full_View (Prev);
2463 Set_Is_Pure (T, Is_Pure (Current_Scope));
2465 -- We set the flag Is_First_Subtype here. It is needed to set the
2466 -- corresponding flag for the Implicit class-wide-type created
2467 -- during tagged types processing.
2469 Set_Is_First_Subtype (T, True);
2471 -- Only composite types other than array types are allowed to have
2476 -- For derived types, the rule will be checked once we've figured
2477 -- out the parent type.
2479 when N_Derived_Type_Definition =>
2482 -- For record types, discriminants are allowed.
2484 when N_Record_Definition =>
2488 if Present (Discriminant_Specifications (N)) then
2490 ("elementary or array type cannot have discriminants",
2492 (First (Discriminant_Specifications (N))));
2496 -- Elaborate the type definition according to kind, and generate
2497 -- subsidiary (implicit) subtypes where needed. We skip this if
2498 -- it was already done (this happens during the reanalysis that
2499 -- follows a call to the high level optimizer).
2501 if not Analyzed (T) then
2506 when N_Access_To_Subprogram_Definition =>
2507 Access_Subprogram_Declaration (T, Def);
2509 -- If this is a remote access to subprogram, we must create
2510 -- the equivalent fat pointer type, and related subprograms.
2513 Process_Remote_AST_Declaration (N);
2516 -- Validate categorization rule against access type declaration
2517 -- usually a violation in Pure unit, Shared_Passive unit.
2519 Validate_Access_Type_Declaration (T, N);
2521 when N_Access_To_Object_Definition =>
2522 Access_Type_Declaration (T, Def);
2524 -- Validate categorization rule against access type declaration
2525 -- usually a violation in Pure unit, Shared_Passive unit.
2527 Validate_Access_Type_Declaration (T, N);
2529 -- If we are in a Remote_Call_Interface package and define
2530 -- a RACW, Read and Write attribute must be added.
2533 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2535 Add_RACW_Features (Def_Id);
2538 when N_Array_Type_Definition =>
2539 Array_Type_Declaration (T, Def);
2541 when N_Derived_Type_Definition =>
2542 Derived_Type_Declaration (T, N, T /= Def_Id);
2544 when N_Enumeration_Type_Definition =>
2545 Enumeration_Type_Declaration (T, Def);
2547 when N_Floating_Point_Definition =>
2548 Floating_Point_Type_Declaration (T, Def);
2550 when N_Decimal_Fixed_Point_Definition =>
2551 Decimal_Fixed_Point_Type_Declaration (T, Def);
2553 when N_Ordinary_Fixed_Point_Definition =>
2554 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2556 when N_Signed_Integer_Type_Definition =>
2557 Signed_Integer_Type_Declaration (T, Def);
2559 when N_Modular_Type_Definition =>
2560 Modular_Type_Declaration (T, Def);
2562 when N_Record_Definition =>
2563 Record_Type_Declaration (T, N, Prev);
2566 raise Program_Error;
2571 if Etype (T) = Any_Type then
2575 -- Some common processing for all types
2577 Set_Depends_On_Private (T, Has_Private_Component (T));
2579 -- Both the declared entity, and its anonymous base type if one
2580 -- was created, need freeze nodes allocated.
2583 B : constant Entity_Id := Base_Type (T);
2586 -- In the case where the base type is different from the first
2587 -- subtype, we pre-allocate a freeze node, and set the proper
2588 -- link to the first subtype. Freeze_Entity will use this
2589 -- preallocated freeze node when it freezes the entity.
2592 Ensure_Freeze_Node (B);
2593 Set_First_Subtype_Link (Freeze_Node (B), T);
2596 if not From_With_Type (T) then
2597 Set_Has_Delayed_Freeze (T);
2601 -- Case of T is the full declaration of some private type which has
2602 -- been swapped in Defining_Identifier (N).
2604 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2605 Process_Full_View (N, T, Def_Id);
2607 -- Record the reference. The form of this is a little strange,
2608 -- since the full declaration has been swapped in. So the first
2609 -- parameter here represents the entity to which a reference is
2610 -- made which is the "real" entity, i.e. the one swapped in,
2611 -- and the second parameter provides the reference location.
2613 Generate_Reference (T, T, 'c');
2614 Set_Completion_Referenced (Def_Id);
2616 -- For completion of incomplete type, process incomplete dependents
2617 -- and always mark the full type as referenced (it is the incomplete
2618 -- type that we get for any real reference).
2620 elsif Ekind (Prev) = E_Incomplete_Type then
2621 Process_Incomplete_Dependents (N, T, Prev);
2622 Generate_Reference (Prev, Def_Id, 'c');
2623 Set_Completion_Referenced (Def_Id);
2625 -- If not private type or incomplete type completion, this is a real
2626 -- definition of a new entity, so record it.
2629 Generate_Definition (Def_Id);
2632 Check_Eliminated (Def_Id);
2633 end Analyze_Type_Declaration;
2635 --------------------------
2636 -- Analyze_Variant_Part --
2637 --------------------------
2639 procedure Analyze_Variant_Part (N : Node_Id) is
2641 procedure Non_Static_Choice_Error (Choice : Node_Id);
2642 -- Error routine invoked by the generic instantiation below when
2643 -- the variant part has a non static choice.
2645 procedure Process_Declarations (Variant : Node_Id);
2646 -- Analyzes all the declarations associated with a Variant.
2647 -- Needed by the generic instantiation below.
2649 package Variant_Choices_Processing is new
2650 Generic_Choices_Processing
2651 (Get_Alternatives => Variants,
2652 Get_Choices => Discrete_Choices,
2653 Process_Empty_Choice => No_OP,
2654 Process_Non_Static_Choice => Non_Static_Choice_Error,
2655 Process_Associated_Node => Process_Declarations);
2656 use Variant_Choices_Processing;
2657 -- Instantiation of the generic choice processing package.
2659 -----------------------------
2660 -- Non_Static_Choice_Error --
2661 -----------------------------
2663 procedure Non_Static_Choice_Error (Choice : Node_Id) is
2665 Flag_Non_Static_Expr
2666 ("choice given in variant part is not static!", Choice);
2667 end Non_Static_Choice_Error;
2669 --------------------------
2670 -- Process_Declarations --
2671 --------------------------
2673 procedure Process_Declarations (Variant : Node_Id) is
2675 if not Null_Present (Component_List (Variant)) then
2676 Analyze_Declarations (Component_Items (Component_List (Variant)));
2678 if Present (Variant_Part (Component_List (Variant))) then
2679 Analyze (Variant_Part (Component_List (Variant)));
2682 end Process_Declarations;
2684 -- Variables local to Analyze_Case_Statement.
2686 Discr_Name : Node_Id;
2687 Discr_Type : Entity_Id;
2689 Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
2691 Dont_Care : Boolean;
2692 Others_Present : Boolean := False;
2694 -- Start of processing for Analyze_Variant_Part
2697 Discr_Name := Name (N);
2698 Analyze (Discr_Name);
2700 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
2701 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
2704 Discr_Type := Etype (Entity (Discr_Name));
2706 if not Is_Discrete_Type (Discr_Type) then
2708 ("discriminant in a variant part must be of a discrete type",
2713 -- Call the instantiated Analyze_Choices which does the rest of the work
2716 (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
2717 end Analyze_Variant_Part;
2719 ----------------------------
2720 -- Array_Type_Declaration --
2721 ----------------------------
2723 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
2724 Component_Def : constant Node_Id := Subtype_Indication (Def);
2725 Element_Type : Entity_Id;
2726 Implicit_Base : Entity_Id;
2728 Related_Id : Entity_Id := Empty;
2730 P : constant Node_Id := Parent (Def);
2734 if Nkind (Def) = N_Constrained_Array_Definition then
2736 Index := First (Discrete_Subtype_Definitions (Def));
2738 -- Find proper names for the implicit types which may be public.
2739 -- in case of anonymous arrays we use the name of the first object
2740 -- of that type as prefix.
2743 Related_Id := Defining_Identifier (P);
2749 Index := First (Subtype_Marks (Def));
2754 while Present (Index) loop
2756 Make_Index (Index, P, Related_Id, Nb_Index);
2758 Nb_Index := Nb_Index + 1;
2761 Element_Type := Process_Subtype (Component_Def, P, Related_Id, 'C');
2763 -- Constrained array case
2766 T := Create_Itype (E_Void, P, Related_Id, 'T');
2769 if Nkind (Def) = N_Constrained_Array_Definition then
2771 -- Establish Implicit_Base as unconstrained base type
2773 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
2775 Init_Size_Align (Implicit_Base);
2776 Set_Etype (Implicit_Base, Implicit_Base);
2777 Set_Scope (Implicit_Base, Current_Scope);
2778 Set_Has_Delayed_Freeze (Implicit_Base);
2780 -- The constrained array type is a subtype of the unconstrained one
2782 Set_Ekind (T, E_Array_Subtype);
2783 Init_Size_Align (T);
2784 Set_Etype (T, Implicit_Base);
2785 Set_Scope (T, Current_Scope);
2786 Set_Is_Constrained (T, True);
2787 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
2788 Set_Has_Delayed_Freeze (T);
2790 -- Complete setup of implicit base type
2792 Set_First_Index (Implicit_Base, First_Index (T));
2793 Set_Component_Type (Implicit_Base, Element_Type);
2794 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
2795 Set_Component_Size (Implicit_Base, Uint_0);
2796 Set_Has_Controlled_Component
2797 (Implicit_Base, Has_Controlled_Component
2800 Is_Controlled (Element_Type));
2801 Set_Finalize_Storage_Only
2802 (Implicit_Base, Finalize_Storage_Only
2805 -- Unconstrained array case
2808 Set_Ekind (T, E_Array_Type);
2809 Init_Size_Align (T);
2811 Set_Scope (T, Current_Scope);
2812 Set_Component_Size (T, Uint_0);
2813 Set_Is_Constrained (T, False);
2814 Set_First_Index (T, First (Subtype_Marks (Def)));
2815 Set_Has_Delayed_Freeze (T, True);
2816 Set_Has_Task (T, Has_Task (Element_Type));
2817 Set_Has_Controlled_Component (T, Has_Controlled_Component
2820 Is_Controlled (Element_Type));
2821 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
2825 Set_Component_Type (Base_Type (T), Element_Type);
2827 if Aliased_Present (Def) then
2828 Set_Has_Aliased_Components (Etype (T));
2831 Priv := Private_Component (Element_Type);
2833 if Present (Priv) then
2835 -- Check for circular definitions
2837 if Priv = Any_Type then
2838 Set_Component_Type (Etype (T), Any_Type);
2840 -- There is a gap in the visibility of operations on the composite
2841 -- type only if the component type is defined in a different scope.
2843 elsif Scope (Priv) = Current_Scope then
2846 elsif Is_Limited_Type (Priv) then
2847 Set_Is_Limited_Composite (Etype (T));
2848 Set_Is_Limited_Composite (T);
2850 Set_Is_Private_Composite (Etype (T));
2851 Set_Is_Private_Composite (T);
2855 -- Create a concatenation operator for the new type. Internal
2856 -- array types created for packed entities do not need such, they
2857 -- are compatible with the user-defined type.
2859 if Number_Dimensions (T) = 1
2860 and then not Is_Packed_Array_Type (T)
2862 New_Binary_Operator (Name_Op_Concat, T);
2865 -- In the case of an unconstrained array the parser has already
2866 -- verified that all the indices are unconstrained but we still
2867 -- need to make sure that the element type is constrained.
2869 if Is_Indefinite_Subtype (Element_Type) then
2871 ("unconstrained element type in array declaration ",
2874 elsif Is_Abstract (Element_Type) then
2875 Error_Msg_N ("The type of a component cannot be abstract ",
2879 end Array_Type_Declaration;
2881 -------------------------------
2882 -- Build_Derived_Access_Type --
2883 -------------------------------
2885 procedure Build_Derived_Access_Type
2887 Parent_Type : Entity_Id;
2888 Derived_Type : Entity_Id)
2890 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
2892 Desig_Type : Entity_Id;
2894 Discr_Con_Elist : Elist_Id;
2895 Discr_Con_El : Elmt_Id;
2900 -- Set the designated type so it is available in case this is
2901 -- an access to a self-referential type, e.g. a standard list
2902 -- type with a next pointer. Will be reset after subtype is built.
2904 Set_Directly_Designated_Type (Derived_Type,
2905 Designated_Type (Parent_Type));
2907 Subt := Process_Subtype (S, N);
2909 if Nkind (S) /= N_Subtype_Indication
2910 and then Subt /= Base_Type (Subt)
2912 Set_Ekind (Derived_Type, E_Access_Subtype);
2915 if Ekind (Derived_Type) = E_Access_Subtype then
2917 Pbase : constant Entity_Id := Base_Type (Parent_Type);
2918 Ibase : constant Entity_Id :=
2919 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
2920 Svg_Chars : constant Name_Id := Chars (Ibase);
2921 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
2924 Copy_Node (Pbase, Ibase);
2926 Set_Chars (Ibase, Svg_Chars);
2927 Set_Next_Entity (Ibase, Svg_Next_E);
2928 Set_Sloc (Ibase, Sloc (Derived_Type));
2929 Set_Scope (Ibase, Scope (Derived_Type));
2930 Set_Freeze_Node (Ibase, Empty);
2931 Set_Is_Frozen (Ibase, False);
2932 Set_Comes_From_Source (Ibase, False);
2933 Set_Is_First_Subtype (Ibase, False);
2935 Set_Etype (Ibase, Pbase);
2936 Set_Etype (Derived_Type, Ibase);
2940 Set_Directly_Designated_Type
2941 (Derived_Type, Designated_Type (Subt));
2943 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
2944 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
2945 Set_Size_Info (Derived_Type, Parent_Type);
2946 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
2947 Set_Depends_On_Private (Derived_Type,
2948 Has_Private_Component (Derived_Type));
2949 Conditional_Delay (Derived_Type, Subt);
2951 -- Note: we do not copy the Storage_Size_Variable, since
2952 -- we always go to the root type for this information.
2954 -- Apply range checks to discriminants for derived record case
2955 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
2957 Desig_Type := Designated_Type (Derived_Type);
2958 if Is_Composite_Type (Desig_Type)
2959 and then (not Is_Array_Type (Desig_Type))
2960 and then Has_Discriminants (Desig_Type)
2961 and then Base_Type (Desig_Type) /= Desig_Type
2963 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
2964 Discr_Con_El := First_Elmt (Discr_Con_Elist);
2966 Discr := First_Discriminant (Base_Type (Desig_Type));
2967 while Present (Discr_Con_El) loop
2968 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
2969 Next_Elmt (Discr_Con_El);
2970 Next_Discriminant (Discr);
2973 end Build_Derived_Access_Type;
2975 ------------------------------
2976 -- Build_Derived_Array_Type --
2977 ------------------------------
2979 procedure Build_Derived_Array_Type
2981 Parent_Type : Entity_Id;
2982 Derived_Type : Entity_Id)
2984 Loc : constant Source_Ptr := Sloc (N);
2985 Tdef : constant Node_Id := Type_Definition (N);
2986 Indic : constant Node_Id := Subtype_Indication (Tdef);
2987 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
2988 Implicit_Base : Entity_Id;
2989 New_Indic : Node_Id;
2991 procedure Make_Implicit_Base;
2992 -- If the parent subtype is constrained, the derived type is a
2993 -- subtype of an implicit base type derived from the parent base.
2995 ------------------------
2996 -- Make_Implicit_Base --
2997 ------------------------
2999 procedure Make_Implicit_Base is
3002 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3004 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3005 Set_Etype (Implicit_Base, Parent_Base);
3007 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
3008 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
3010 Set_Has_Delayed_Freeze (Implicit_Base, True);
3011 end Make_Implicit_Base;
3013 -- Start of processing for Build_Derived_Array_Type
3016 if not Is_Constrained (Parent_Type) then
3017 if Nkind (Indic) /= N_Subtype_Indication then
3018 Set_Ekind (Derived_Type, E_Array_Type);
3020 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
3021 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
3023 Set_Has_Delayed_Freeze (Derived_Type, True);
3027 Set_Etype (Derived_Type, Implicit_Base);
3030 Make_Subtype_Declaration (Loc,
3031 Defining_Identifier => Derived_Type,
3032 Subtype_Indication =>
3033 Make_Subtype_Indication (Loc,
3034 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
3035 Constraint => Constraint (Indic)));
3037 Rewrite (N, New_Indic);
3042 if Nkind (Indic) /= N_Subtype_Indication then
3045 Set_Ekind (Derived_Type, Ekind (Parent_Type));
3046 Set_Etype (Derived_Type, Implicit_Base);
3047 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
3050 Error_Msg_N ("illegal constraint on constrained type", Indic);
3054 -- If the parent type is not a derived type itself, and is
3055 -- declared in a closed scope (e.g., a subprogram), then we
3056 -- need to explicitly introduce the new type's concatenation
3057 -- operator since Derive_Subprograms will not inherit the
3058 -- parent's operator.
3060 if Number_Dimensions (Parent_Type) = 1
3061 and then not Is_Limited_Type (Parent_Type)
3062 and then not Is_Derived_Type (Parent_Type)
3063 and then not Is_Package (Scope (Base_Type (Parent_Type)))
3065 New_Binary_Operator (Name_Op_Concat, Derived_Type);
3067 end Build_Derived_Array_Type;
3069 -----------------------------------
3070 -- Build_Derived_Concurrent_Type --
3071 -----------------------------------
3073 procedure Build_Derived_Concurrent_Type
3075 Parent_Type : Entity_Id;
3076 Derived_Type : Entity_Id)
3078 D_Constraint : Node_Id;
3079 Disc_Spec : Node_Id;
3080 Old_Disc : Entity_Id;
3081 New_Disc : Entity_Id;
3083 Constraint_Present : constant Boolean :=
3084 Nkind (Subtype_Indication (Type_Definition (N)))
3085 = N_Subtype_Indication;
3088 Set_Stored_Constraint (Derived_Type, No_Elist);
3090 if Is_Task_Type (Parent_Type) then
3091 Set_Storage_Size_Variable (Derived_Type,
3092 Storage_Size_Variable (Parent_Type));
3095 if Present (Discriminant_Specifications (N)) then
3096 New_Scope (Derived_Type);
3097 Check_Or_Process_Discriminants (N, Derived_Type);
3100 elsif Constraint_Present then
3102 -- Build constrained subtype and derive from it
3105 Loc : constant Source_Ptr := Sloc (N);
3106 Anon : constant Entity_Id :=
3107 Make_Defining_Identifier (Loc,
3108 New_External_Name (Chars (Derived_Type), 'T'));
3113 Make_Subtype_Declaration (Loc,
3114 Defining_Identifier => Anon,
3115 Subtype_Indication =>
3116 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
3117 Insert_Before (N, Decl);
3118 Rewrite (Subtype_Indication (Type_Definition (N)),
3119 New_Occurrence_Of (Anon, Loc));
3121 Set_Analyzed (Derived_Type, False);
3127 -- All attributes are inherited from parent. In particular,
3128 -- entries and the corresponding record type are the same.
3129 -- Discriminants may be renamed, and must be treated separately.
3131 Set_Has_Discriminants
3132 (Derived_Type, Has_Discriminants (Parent_Type));
3133 Set_Corresponding_Record_Type
3134 (Derived_Type, Corresponding_Record_Type (Parent_Type));
3136 if Constraint_Present then
3138 if not Has_Discriminants (Parent_Type) then
3139 Error_Msg_N ("untagged parent must have discriminants", N);
3141 elsif Present (Discriminant_Specifications (N)) then
3143 -- Verify that new discriminants are used to constrain
3146 Old_Disc := First_Discriminant (Parent_Type);
3147 New_Disc := First_Discriminant (Derived_Type);
3148 Disc_Spec := First (Discriminant_Specifications (N));
3152 (Constraint (Subtype_Indication (Type_Definition (N)))));
3154 while Present (Old_Disc) and then Present (Disc_Spec) loop
3156 if Nkind (Discriminant_Type (Disc_Spec)) /=
3159 Analyze (Discriminant_Type (Disc_Spec));
3161 if not Subtypes_Statically_Compatible (
3162 Etype (Discriminant_Type (Disc_Spec)),
3166 ("not statically compatible with parent discriminant",
3167 Discriminant_Type (Disc_Spec));
3171 if Nkind (D_Constraint) = N_Identifier
3172 and then Chars (D_Constraint) /=
3173 Chars (Defining_Identifier (Disc_Spec))
3175 Error_Msg_N ("new discriminants must constrain old ones",
3178 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
3181 Next_Discriminant (Old_Disc);
3182 Next_Discriminant (New_Disc);
3186 if Present (Old_Disc) or else Present (Disc_Spec) then
3187 Error_Msg_N ("discriminant mismatch in derivation", N);
3192 elsif Present (Discriminant_Specifications (N)) then
3194 ("missing discriminant constraint in untagged derivation",
3198 if Present (Discriminant_Specifications (N)) then
3200 Old_Disc := First_Discriminant (Parent_Type);
3202 while Present (Old_Disc) loop
3204 if No (Next_Entity (Old_Disc))
3205 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
3207 Set_Next_Entity (Last_Entity (Derived_Type),
3208 Next_Entity (Old_Disc));
3212 Next_Discriminant (Old_Disc);
3216 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
3217 if Has_Discriminants (Parent_Type) then
3218 Set_Discriminant_Constraint (
3219 Derived_Type, Discriminant_Constraint (Parent_Type));
3223 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
3225 Set_Has_Completion (Derived_Type);
3226 end Build_Derived_Concurrent_Type;
3228 ------------------------------------
3229 -- Build_Derived_Enumeration_Type --
3230 ------------------------------------
3232 procedure Build_Derived_Enumeration_Type
3234 Parent_Type : Entity_Id;
3235 Derived_Type : Entity_Id)
3237 Loc : constant Source_Ptr := Sloc (N);
3238 Def : constant Node_Id := Type_Definition (N);
3239 Indic : constant Node_Id := Subtype_Indication (Def);
3240 Implicit_Base : Entity_Id;
3241 Literal : Entity_Id;
3242 New_Lit : Entity_Id;
3243 Literals_List : List_Id;
3244 Type_Decl : Node_Id;
3246 Rang_Expr : Node_Id;
3249 -- Since types Standard.Character and Standard.Wide_Character do
3250 -- not have explicit literals lists we need to process types derived
3251 -- from them specially. This is handled by Derived_Standard_Character.
3252 -- If the parent type is a generic type, there are no literals either,
3253 -- and we construct the same skeletal representation as for the generic
3256 if Root_Type (Parent_Type) = Standard_Character
3257 or else Root_Type (Parent_Type) = Standard_Wide_Character
3259 Derived_Standard_Character (N, Parent_Type, Derived_Type);
3261 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
3268 Make_Attribute_Reference (Loc,
3269 Attribute_Name => Name_First,
3270 Prefix => New_Reference_To (Derived_Type, Loc));
3271 Set_Etype (Lo, Derived_Type);
3274 Make_Attribute_Reference (Loc,
3275 Attribute_Name => Name_Last,
3276 Prefix => New_Reference_To (Derived_Type, Loc));
3277 Set_Etype (Hi, Derived_Type);
3279 Set_Scalar_Range (Derived_Type,
3286 -- If a constraint is present, analyze the bounds to catch
3287 -- premature usage of the derived literals.
3289 if Nkind (Indic) = N_Subtype_Indication
3290 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
3292 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
3293 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
3296 -- Introduce an implicit base type for the derived type even
3297 -- if there is no constraint attached to it, since this seems
3298 -- closer to the Ada semantics. Build a full type declaration
3299 -- tree for the derived type using the implicit base type as
3300 -- the defining identifier. The build a subtype declaration
3301 -- tree which applies the constraint (if any) have it replace
3302 -- the derived type declaration.
3304 Literal := First_Literal (Parent_Type);
3305 Literals_List := New_List;
3307 while Present (Literal)
3308 and then Ekind (Literal) = E_Enumeration_Literal
3310 -- Literals of the derived type have the same representation as
3311 -- those of the parent type, but this representation can be
3312 -- overridden by an explicit representation clause. Indicate
3313 -- that there is no explicit representation given yet. These
3314 -- derived literals are implicit operations of the new type,
3315 -- and can be overriden by explicit ones.
3317 if Nkind (Literal) = N_Defining_Character_Literal then
3319 Make_Defining_Character_Literal (Loc, Chars (Literal));
3321 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
3324 Set_Ekind (New_Lit, E_Enumeration_Literal);
3325 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
3326 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
3327 Set_Enumeration_Rep_Expr (New_Lit, Empty);
3328 Set_Alias (New_Lit, Literal);
3329 Set_Is_Known_Valid (New_Lit, True);
3331 Append (New_Lit, Literals_List);
3332 Next_Literal (Literal);
3336 Make_Defining_Identifier (Sloc (Derived_Type),
3337 New_External_Name (Chars (Derived_Type), 'B'));
3339 -- Indicate the proper nature of the derived type. This must
3340 -- be done before analysis of the literals, to recognize cases
3341 -- when a literal may be hidden by a previous explicit function
3342 -- definition (cf. c83031a).
3344 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
3345 Set_Etype (Derived_Type, Implicit_Base);
3348 Make_Full_Type_Declaration (Loc,
3349 Defining_Identifier => Implicit_Base,
3350 Discriminant_Specifications => No_List,
3352 Make_Enumeration_Type_Definition (Loc, Literals_List));
3354 Mark_Rewrite_Insertion (Type_Decl);
3355 Insert_Before (N, Type_Decl);
3356 Analyze (Type_Decl);
3358 -- After the implicit base is analyzed its Etype needs to be
3359 -- changed to reflect the fact that it is derived from the
3360 -- parent type which was ignored during analysis. We also set
3361 -- the size at this point.
3363 Set_Etype (Implicit_Base, Parent_Type);
3365 Set_Size_Info (Implicit_Base, Parent_Type);
3366 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
3367 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
3369 Set_Has_Non_Standard_Rep
3370 (Implicit_Base, Has_Non_Standard_Rep
3372 Set_Has_Delayed_Freeze (Implicit_Base);
3374 -- Process the subtype indication including a validation check
3375 -- on the constraint, if any. If a constraint is given, its bounds
3376 -- must be implicitly converted to the new type.
3378 if Nkind (Indic) = N_Subtype_Indication then
3381 R : constant Node_Id :=
3382 Range_Expression (Constraint (Indic));
3385 if Nkind (R) = N_Range then
3386 Hi := Build_Scalar_Bound
3387 (High_Bound (R), Parent_Type, Implicit_Base);
3388 Lo := Build_Scalar_Bound
3389 (Low_Bound (R), Parent_Type, Implicit_Base);
3392 -- Constraint is a Range attribute. Replace with the
3393 -- explicit mention of the bounds of the prefix, which
3394 -- must be a subtype.
3396 Analyze (Prefix (R));
3398 Convert_To (Implicit_Base,
3399 Make_Attribute_Reference (Loc,
3400 Attribute_Name => Name_Last,
3402 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3405 Convert_To (Implicit_Base,
3406 Make_Attribute_Reference (Loc,
3407 Attribute_Name => Name_First,
3409 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3417 (Type_High_Bound (Parent_Type),
3418 Parent_Type, Implicit_Base);
3421 (Type_Low_Bound (Parent_Type),
3422 Parent_Type, Implicit_Base);
3430 -- If we constructed a default range for the case where no range
3431 -- was given, then the expressions in the range must not freeze
3432 -- since they do not correspond to expressions in the source.
3434 if Nkind (Indic) /= N_Subtype_Indication then
3435 Set_Must_Not_Freeze (Lo);
3436 Set_Must_Not_Freeze (Hi);
3437 Set_Must_Not_Freeze (Rang_Expr);
3441 Make_Subtype_Declaration (Loc,
3442 Defining_Identifier => Derived_Type,
3443 Subtype_Indication =>
3444 Make_Subtype_Indication (Loc,
3445 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
3447 Make_Range_Constraint (Loc,
3448 Range_Expression => Rang_Expr))));
3452 -- If pragma Discard_Names applies on the first subtype
3453 -- of the parent type, then it must be applied on this
3456 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
3457 Set_Discard_Names (Derived_Type);
3460 -- Apply a range check. Since this range expression doesn't
3461 -- have an Etype, we have to specifically pass the Source_Typ
3462 -- parameter. Is this right???
3464 if Nkind (Indic) = N_Subtype_Indication then
3465 Apply_Range_Check (Range_Expression (Constraint (Indic)),
3467 Source_Typ => Entity (Subtype_Mark (Indic)));
3470 end Build_Derived_Enumeration_Type;
3472 --------------------------------
3473 -- Build_Derived_Numeric_Type --
3474 --------------------------------
3476 procedure Build_Derived_Numeric_Type
3478 Parent_Type : Entity_Id;
3479 Derived_Type : Entity_Id)
3481 Loc : constant Source_Ptr := Sloc (N);
3482 Tdef : constant Node_Id := Type_Definition (N);
3483 Indic : constant Node_Id := Subtype_Indication (Tdef);
3484 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3485 No_Constraint : constant Boolean := Nkind (Indic) /=
3486 N_Subtype_Indication;
3487 Implicit_Base : Entity_Id;
3493 -- Process the subtype indication including a validation check on
3494 -- the constraint if any.
3496 Discard_Node (Process_Subtype (Indic, N));
3498 -- Introduce an implicit base type for the derived type even if
3499 -- there is no constraint attached to it, since this seems closer
3500 -- to the Ada semantics.
3503 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3505 Set_Etype (Implicit_Base, Parent_Base);
3506 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3507 Set_Size_Info (Implicit_Base, Parent_Base);
3508 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3509 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
3510 Set_Parent (Implicit_Base, Parent (Derived_Type));
3512 if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
3513 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3516 Set_Has_Delayed_Freeze (Implicit_Base);
3518 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
3519 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
3521 Set_Scalar_Range (Implicit_Base,
3526 if Has_Infinities (Parent_Base) then
3527 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
3530 -- The Derived_Type, which is the entity of the declaration, is
3531 -- a subtype of the implicit base. Its Ekind is a subtype, even
3532 -- in the absence of an explicit constraint.
3534 Set_Etype (Derived_Type, Implicit_Base);
3536 -- If we did not have a constraint, then the Ekind is set from the
3537 -- parent type (otherwise Process_Subtype has set the bounds)
3539 if No_Constraint then
3540 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
3543 -- If we did not have a range constraint, then set the range
3544 -- from the parent type. Otherwise, the call to Process_Subtype
3545 -- has set the bounds.
3548 or else not Has_Range_Constraint (Indic)
3550 Set_Scalar_Range (Derived_Type,
3552 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
3553 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
3554 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3556 if Has_Infinities (Parent_Type) then
3557 Set_Includes_Infinities (Scalar_Range (Derived_Type));
3561 -- Set remaining type-specific fields, depending on numeric type
3563 if Is_Modular_Integer_Type (Parent_Type) then
3564 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
3566 Set_Non_Binary_Modulus
3567 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
3569 elsif Is_Floating_Point_Type (Parent_Type) then
3571 -- Digits of base type is always copied from the digits value of
3572 -- the parent base type, but the digits of the derived type will
3573 -- already have been set if there was a constraint present.
3575 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3576 Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
3578 if No_Constraint then
3579 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
3582 elsif Is_Fixed_Point_Type (Parent_Type) then
3584 -- Small of base type and derived type are always copied from
3585 -- the parent base type, since smalls never change. The delta
3586 -- of the base type is also copied from the parent base type.
3587 -- However the delta of the derived type will have been set
3588 -- already if a constraint was present.
3590 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
3591 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
3592 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
3594 if No_Constraint then
3595 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
3598 -- The scale and machine radix in the decimal case are always
3599 -- copied from the parent base type.
3601 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
3602 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
3603 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
3605 Set_Machine_Radix_10
3606 (Derived_Type, Machine_Radix_10 (Parent_Base));
3607 Set_Machine_Radix_10
3608 (Implicit_Base, Machine_Radix_10 (Parent_Base));
3610 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3612 if No_Constraint then
3613 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
3616 -- the analysis of the subtype_indication sets the
3617 -- digits value of the derived type.
3624 -- The type of the bounds is that of the parent type, and they
3625 -- must be converted to the derived type.
3627 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
3629 -- The implicit_base should be frozen when the derived type is frozen,
3630 -- but note that it is used in the conversions of the bounds. For
3631 -- fixed types we delay the determination of the bounds until the proper
3632 -- freezing point. For other numeric types this is rejected by GCC, for
3633 -- reasons that are currently unclear (???), so we choose to freeze the
3634 -- implicit base now. In the case of integers and floating point types
3635 -- this is harmless because subsequent representation clauses cannot
3636 -- affect anything, but it is still baffling that we cannot use the
3637 -- same mechanism for all derived numeric types.
3639 if Is_Fixed_Point_Type (Parent_Type) then
3640 Conditional_Delay (Implicit_Base, Parent_Type);
3642 Freeze_Before (N, Implicit_Base);
3644 end Build_Derived_Numeric_Type;
3646 --------------------------------
3647 -- Build_Derived_Private_Type --
3648 --------------------------------
3650 procedure Build_Derived_Private_Type
3652 Parent_Type : Entity_Id;
3653 Derived_Type : Entity_Id;
3654 Is_Completion : Boolean;
3655 Derive_Subps : Boolean := True)
3657 Der_Base : Entity_Id;
3659 Full_Decl : Node_Id := Empty;
3660 Full_Der : Entity_Id;
3662 Last_Discr : Entity_Id;
3663 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
3664 Swapped : Boolean := False;
3666 procedure Copy_And_Build;
3667 -- Copy derived type declaration, replace parent with its full view,
3668 -- and analyze new declaration.
3670 --------------------
3671 -- Copy_And_Build --
3672 --------------------
3674 procedure Copy_And_Build is
3678 if Ekind (Parent_Type) in Record_Kind
3679 or else (Ekind (Parent_Type) in Enumeration_Kind
3680 and then Root_Type (Parent_Type) /= Standard_Character
3681 and then Root_Type (Parent_Type) /= Standard_Wide_Character
3682 and then not Is_Generic_Type (Root_Type (Parent_Type)))
3684 Full_N := New_Copy_Tree (N);
3685 Insert_After (N, Full_N);
3686 Build_Derived_Type (
3687 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
3690 Build_Derived_Type (
3691 N, Parent_Type, Full_Der, True, Derive_Subps => False);
3695 -- Start of processing for Build_Derived_Private_Type
3698 if Is_Tagged_Type (Parent_Type) then
3699 Build_Derived_Record_Type
3700 (N, Parent_Type, Derived_Type, Derive_Subps);
3703 elsif Has_Discriminants (Parent_Type) then
3705 if Present (Full_View (Parent_Type)) then
3706 if not Is_Completion then
3708 -- Copy declaration for subsequent analysis, to
3709 -- provide a completion for what is a private
3712 Full_Decl := New_Copy_Tree (N);
3713 Full_Der := New_Copy (Derived_Type);
3715 Insert_After (N, Full_Decl);
3718 -- If this is a completion, the full view being built is
3719 -- itself private. We build a subtype of the parent with
3720 -- the same constraints as this full view, to convey to the
3721 -- back end the constrained components and the size of this
3722 -- subtype. If the parent is constrained, its full view can
3723 -- serve as the underlying full view of the derived type.
3725 if No (Discriminant_Specifications (N)) then
3727 if Nkind (Subtype_Indication (Type_Definition (N)))
3728 = N_Subtype_Indication
3730 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
3732 elsif Is_Constrained (Full_View (Parent_Type)) then
3733 Set_Underlying_Full_View (Derived_Type,
3734 Full_View (Parent_Type));
3738 -- If there are new discriminants, the parent subtype is
3739 -- constrained by them, but it is not clear how to build
3740 -- the underlying_full_view in this case ???
3747 -- Build partial view of derived type from partial view of parent.
3749 Build_Derived_Record_Type
3750 (N, Parent_Type, Derived_Type, Derive_Subps);
3752 if Present (Full_View (Parent_Type))
3753 and then not Is_Completion
3755 if not In_Open_Scopes (Par_Scope)
3756 or else not In_Same_Source_Unit (N, Parent_Type)
3758 -- Swap partial and full views temporarily
3760 Install_Private_Declarations (Par_Scope);
3761 Install_Visible_Declarations (Par_Scope);
3765 -- Build full view of derived type from full view of
3766 -- parent which is now installed.
3767 -- Subprograms have been derived on the partial view,
3768 -- the completion does not derive them anew.
3770 if not Is_Tagged_Type (Parent_Type) then
3771 Build_Derived_Record_Type
3772 (Full_Decl, Parent_Type, Full_Der, False);
3775 -- If full view of parent is tagged, the completion
3776 -- inherits the proper primitive operations.
3778 Set_Defining_Identifier (Full_Decl, Full_Der);
3779 Build_Derived_Record_Type
3780 (Full_Decl, Parent_Type, Full_Der, Derive_Subps);
3781 Set_Analyzed (Full_Decl);
3785 Uninstall_Declarations (Par_Scope);
3787 if In_Open_Scopes (Par_Scope) then
3788 Install_Visible_Declarations (Par_Scope);
3792 Der_Base := Base_Type (Derived_Type);
3793 Set_Full_View (Derived_Type, Full_Der);
3794 Set_Full_View (Der_Base, Base_Type (Full_Der));
3796 -- Copy the discriminant list from full view to
3797 -- the partial views (base type and its subtype).
3798 -- Gigi requires that the partial and full views
3799 -- have the same discriminants.
3800 -- ??? Note that since the partial view is pointing
3801 -- to discriminants in the full view, their scope
3802 -- will be that of the full view. This might
3803 -- cause some front end problems and need
3806 Discr := First_Discriminant (Base_Type (Full_Der));
3807 Set_First_Entity (Der_Base, Discr);
3810 Last_Discr := Discr;
3811 Next_Discriminant (Discr);
3812 exit when No (Discr);
3815 Set_Last_Entity (Der_Base, Last_Discr);
3817 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
3818 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
3821 -- If this is a completion, the derived type stays private
3822 -- and there is no need to create a further full view, except
3823 -- in the unusual case when the derivation is nested within a
3824 -- child unit, see below.
3829 elsif Present (Full_View (Parent_Type))
3830 and then Has_Discriminants (Full_View (Parent_Type))
3832 if Has_Unknown_Discriminants (Parent_Type)
3833 and then Nkind (Subtype_Indication (Type_Definition (N)))
3834 = N_Subtype_Indication
3837 ("cannot constrain type with unknown discriminants",
3838 Subtype_Indication (Type_Definition (N)));
3842 -- If full view of parent is a record type, Build full view as
3843 -- a derivation from the parent's full view. Partial view remains
3844 -- private. For code generation and linking, the full view must
3845 -- have the same public status as the partial one. This full view
3846 -- is only needed if the parent type is in an enclosing scope, so
3847 -- that the full view may actually become visible, e.g. in a child
3848 -- unit. This is both more efficient, and avoids order of freezing
3849 -- problems with the added entities.
3851 if not Is_Private_Type (Full_View (Parent_Type))
3852 and then (In_Open_Scopes (Scope (Parent_Type)))
3854 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
3855 Chars (Derived_Type));
3856 Set_Is_Itype (Full_Der);
3857 Set_Has_Private_Declaration (Full_Der);
3858 Set_Has_Private_Declaration (Derived_Type);
3859 Set_Associated_Node_For_Itype (Full_Der, N);
3860 Set_Parent (Full_Der, Parent (Derived_Type));
3861 Set_Full_View (Derived_Type, Full_Der);
3862 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
3863 Full_P := Full_View (Parent_Type);
3864 Exchange_Declarations (Parent_Type);
3866 Exchange_Declarations (Full_P);
3869 Build_Derived_Record_Type
3870 (N, Full_View (Parent_Type), Derived_Type,
3871 Derive_Subps => False);
3874 -- In any case, the primitive operations are inherited from
3875 -- the parent type, not from the internal full view.
3877 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
3879 if Derive_Subps then
3880 Derive_Subprograms (Parent_Type, Derived_Type);
3884 -- Untagged type, No discriminants on either view
3886 if Nkind (Subtype_Indication (Type_Definition (N)))
3887 = N_Subtype_Indication
3890 ("illegal constraint on type without discriminants", N);
3893 if Present (Discriminant_Specifications (N))
3894 and then Present (Full_View (Parent_Type))
3895 and then not Is_Tagged_Type (Full_View (Parent_Type))
3898 ("cannot add discriminants to untagged type", N);
3901 Set_Stored_Constraint (Derived_Type, No_Elist);
3902 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3903 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
3904 Set_Has_Controlled_Component
3905 (Derived_Type, Has_Controlled_Component
3908 -- Direct controlled types do not inherit Finalize_Storage_Only flag
3910 if not Is_Controlled (Parent_Type) then
3911 Set_Finalize_Storage_Only
3912 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
3915 -- Construct the implicit full view by deriving from full
3916 -- view of the parent type. In order to get proper visibility,
3917 -- we install the parent scope and its declarations.
3919 -- ??? if the parent is untagged private and its
3920 -- completion is tagged, this mechanism will not
3921 -- work because we cannot derive from the tagged
3922 -- full view unless we have an extension
3924 if Present (Full_View (Parent_Type))
3925 and then not Is_Tagged_Type (Full_View (Parent_Type))
3926 and then not Is_Completion
3928 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
3929 Chars (Derived_Type));
3930 Set_Is_Itype (Full_Der);
3931 Set_Has_Private_Declaration (Full_Der);
3932 Set_Has_Private_Declaration (Derived_Type);
3933 Set_Associated_Node_For_Itype (Full_Der, N);
3934 Set_Parent (Full_Der, Parent (Derived_Type));
3935 Set_Full_View (Derived_Type, Full_Der);
3937 if not In_Open_Scopes (Par_Scope) then
3938 Install_Private_Declarations (Par_Scope);
3939 Install_Visible_Declarations (Par_Scope);
3941 Uninstall_Declarations (Par_Scope);
3943 -- If parent scope is open and in another unit, and
3944 -- parent has a completion, then the derivation is taking
3945 -- place in the visible part of a child unit. In that
3946 -- case retrieve the full view of the parent momentarily.
3948 elsif not In_Same_Source_Unit (N, Parent_Type) then
3949 Full_P := Full_View (Parent_Type);
3950 Exchange_Declarations (Parent_Type);
3952 Exchange_Declarations (Full_P);
3954 -- Otherwise it is a local derivation.
3960 Set_Scope (Full_Der, Current_Scope);
3961 Set_Is_First_Subtype (Full_Der,
3962 Is_First_Subtype (Derived_Type));
3963 Set_Has_Size_Clause (Full_Der, False);
3964 Set_Has_Alignment_Clause (Full_Der, False);
3965 Set_Next_Entity (Full_Der, Empty);
3966 Set_Has_Delayed_Freeze (Full_Der);
3967 Set_Is_Frozen (Full_Der, False);
3968 Set_Freeze_Node (Full_Der, Empty);
3969 Set_Depends_On_Private (Full_Der,
3970 Has_Private_Component (Full_Der));
3971 Set_Public_Status (Full_Der);
3975 Set_Has_Unknown_Discriminants (Derived_Type,
3976 Has_Unknown_Discriminants (Parent_Type));
3978 if Is_Private_Type (Derived_Type) then
3979 Set_Private_Dependents (Derived_Type, New_Elmt_List);
3982 if Is_Private_Type (Parent_Type)
3983 and then Base_Type (Parent_Type) = Parent_Type
3984 and then In_Open_Scopes (Scope (Parent_Type))
3986 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
3988 if Is_Child_Unit (Scope (Current_Scope))
3989 and then Is_Completion
3990 and then In_Private_Part (Current_Scope)
3991 and then Scope (Parent_Type) /= Current_Scope
3993 -- This is the unusual case where a type completed by a private
3994 -- derivation occurs within a package nested in a child unit,
3995 -- and the parent is declared in an ancestor. In this case, the
3996 -- full view of the parent type will become visible in the body
3997 -- of the enclosing child, and only then will the current type
3998 -- be possibly non-private. We build a underlying full view that
3999 -- will be installed when the enclosing child body is compiled.
4002 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
4006 Make_Defining_Identifier (Sloc (Derived_Type),
4007 Chars (Derived_Type));
4008 Set_Is_Itype (Full_Der);
4009 Set_Itype (IR, Full_Der);
4010 Insert_After (N, IR);
4012 -- The full view will be used to swap entities on entry/exit
4013 -- to the body, and must appear in the entity list for the
4016 Append_Entity (Full_Der, Scope (Derived_Type));
4017 Set_Has_Private_Declaration (Full_Der);
4018 Set_Has_Private_Declaration (Derived_Type);
4019 Set_Associated_Node_For_Itype (Full_Der, N);
4020 Set_Parent (Full_Der, Parent (Derived_Type));
4021 Full_P := Full_View (Parent_Type);
4022 Exchange_Declarations (Parent_Type);
4024 Exchange_Declarations (Full_P);
4025 Set_Underlying_Full_View (Derived_Type, Full_Der);
4029 end Build_Derived_Private_Type;
4031 -------------------------------
4032 -- Build_Derived_Record_Type --
4033 -------------------------------
4037 -- Ideally we would like to use the same model of type derivation for
4038 -- tagged and untagged record types. Unfortunately this is not quite
4039 -- possible because the semantics of representation clauses is different
4040 -- for tagged and untagged records under inheritance. Consider the
4043 -- type R (...) is [tagged] record ... end record;
4044 -- type T (...) is new R (...) [with ...];
4046 -- The representation clauses of T can specify a completely different
4047 -- record layout from R's. Hence the same component can be placed in
4048 -- two very different positions in objects of type T and R. If R and T
4049 -- are tagged types, representation clauses for T can only specify the
4050 -- layout of non inherited components, thus components that are common
4051 -- in R and T have the same position in objects of type R and T.
4053 -- This has two implications. The first is that the entire tree for R's
4054 -- declaration needs to be copied for T in the untagged case, so that
4055 -- T can be viewed as a record type of its own with its own representation
4056 -- clauses. The second implication is the way we handle discriminants.
4057 -- Specifically, in the untagged case we need a way to communicate to Gigi
4058 -- what are the real discriminants in the record, while for the semantics
4059 -- we need to consider those introduced by the user to rename the
4060 -- discriminants in the parent type. This is handled by introducing the
4061 -- notion of stored discriminants. See below for more.
4063 -- Fortunately the way regular components are inherited can be handled in
4064 -- the same way in tagged and untagged types.
4066 -- To complicate things a bit more the private view of a private extension
4067 -- cannot be handled in the same way as the full view (for one thing the
4068 -- semantic rules are somewhat different). We will explain what differs
4071 -- 2. DISCRIMINANTS UNDER INHERITANCE.
4073 -- The semantic rules governing the discriminants of derived types are
4076 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
4077 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
4079 -- If parent type has discriminants, then the discriminants that are
4080 -- declared in the derived type are [3.4 (11)]:
4082 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
4085 -- o Otherwise, each discriminant of the parent type (implicitly
4086 -- declared in the same order with the same specifications). In this
4087 -- case, the discriminants are said to be "inherited", or if unknown in
4088 -- the parent are also unknown in the derived type.
4090 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
4092 -- o The parent subtype shall be constrained;
4094 -- o If the parent type is not a tagged type, then each discriminant of
4095 -- the derived type shall be used in the constraint defining a parent
4096 -- subtype [Implementation note: this ensures that the new discriminant
4097 -- can share storage with an existing discriminant.].
4099 -- For the derived type each discriminant of the parent type is either
4100 -- inherited, constrained to equal some new discriminant of the derived
4101 -- type, or constrained to the value of an expression.
4103 -- When inherited or constrained to equal some new discriminant, the
4104 -- parent discriminant and the discriminant of the derived type are said
4107 -- If a discriminant of the parent type is constrained to a specific value
4108 -- in the derived type definition, then the discriminant is said to be
4109 -- "specified" by that derived type definition.
4111 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
4113 -- We have spoken about stored discriminants in point 1 (introduction)
4114 -- above. There are two sort of stored discriminants: implicit and
4115 -- explicit. As long as the derived type inherits the same discriminants as
4116 -- the root record type, stored discriminants are the same as regular
4117 -- discriminants, and are said to be implicit. However, if any discriminant
4118 -- in the root type was renamed in the derived type, then the derived
4119 -- type will contain explicit stored discriminants. Explicit stored
4120 -- discriminants are discriminants in addition to the semantically visible
4121 -- discriminants defined for the derived type. Stored discriminants are
4122 -- used by Gigi to figure out what are the physical discriminants in
4123 -- objects of the derived type (see precise definition in einfo.ads).
4124 -- As an example, consider the following:
4126 -- type R (D1, D2, D3 : Int) is record ... end record;
4127 -- type T1 is new R;
4128 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
4129 -- type T3 is new T2;
4130 -- type T4 (Y : Int) is new T3 (Y, 99);
4132 -- The following table summarizes the discriminants and stored
4133 -- discriminants in R and T1 through T4.
4135 -- Type Discrim Stored Discrim Comment
4136 -- R (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in R
4137 -- T1 (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in T1
4138 -- T2 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T2
4139 -- T3 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T3
4140 -- T4 (Y) (D1, D2, D3) Gider discrims are EXPLICIT in T4
4142 -- Field Corresponding_Discriminant (abbreviated CD below) allows to find
4143 -- the corresponding discriminant in the parent type, while
4144 -- Original_Record_Component (abbreviated ORC below), the actual physical
4145 -- component that is renamed. Finally the field Is_Completely_Hidden
4146 -- (abbreviated ICH below) is set for all explicit stored discriminants
4147 -- (see einfo.ads for more info). For the above example this gives:
4149 -- Discrim CD ORC ICH
4150 -- ^^^^^^^ ^^ ^^^ ^^^
4151 -- D1 in R empty itself no
4152 -- D2 in R empty itself no
4153 -- D3 in R empty itself no
4155 -- D1 in T1 D1 in R itself no
4156 -- D2 in T1 D2 in R itself no
4157 -- D3 in T1 D3 in R itself no
4159 -- X1 in T2 D3 in T1 D3 in T2 no
4160 -- X2 in T2 D1 in T1 D1 in T2 no
4161 -- D1 in T2 empty itself yes
4162 -- D2 in T2 empty itself yes
4163 -- D3 in T2 empty itself yes
4165 -- X1 in T3 X1 in T2 D3 in T3 no
4166 -- X2 in T3 X2 in T2 D1 in T3 no
4167 -- D1 in T3 empty itself yes
4168 -- D2 in T3 empty itself yes
4169 -- D3 in T3 empty itself yes
4171 -- Y in T4 X1 in T3 D3 in T3 no
4172 -- D1 in T3 empty itself yes
4173 -- D2 in T3 empty itself yes
4174 -- D3 in T3 empty itself yes
4176 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
4178 -- Type derivation for tagged types is fairly straightforward. if no
4179 -- discriminants are specified by the derived type, these are inherited
4180 -- from the parent. No explicit stored discriminants are ever necessary.
4181 -- The only manipulation that is done to the tree is that of adding a
4182 -- _parent field with parent type and constrained to the same constraint
4183 -- specified for the parent in the derived type definition. For instance:
4185 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
4186 -- type T1 is new R with null record;
4187 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
4189 -- are changed into :
4191 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
4192 -- _parent : R (D1, D2, D3);
4195 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
4196 -- _parent : T1 (X2, 88, X1);
4199 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4200 -- ORC and ICH fields are:
4202 -- Discrim CD ORC ICH
4203 -- ^^^^^^^ ^^ ^^^ ^^^
4204 -- D1 in R empty itself no
4205 -- D2 in R empty itself no
4206 -- D3 in R empty itself no
4208 -- D1 in T1 D1 in R D1 in R no
4209 -- D2 in T1 D2 in R D2 in R no
4210 -- D3 in T1 D3 in R D3 in R no
4212 -- X1 in T2 D3 in T1 D3 in R no
4213 -- X2 in T2 D1 in T1 D1 in R no
4215 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
4217 -- Regardless of whether we dealing with a tagged or untagged type
4218 -- we will transform all derived type declarations of the form
4220 -- type T is new R (...) [with ...];
4222 -- subtype S is R (...);
4223 -- type T is new S [with ...];
4225 -- type BT is new R [with ...];
4226 -- subtype T is BT (...);
4228 -- That is, the base derived type is constrained only if it has no
4229 -- discriminants. The reason for doing this is that GNAT's semantic model
4230 -- assumes that a base type with discriminants is unconstrained.
4232 -- Note that, strictly speaking, the above transformation is not always
4233 -- correct. Consider for instance the following excerpt from ACVC b34011a:
4235 -- procedure B34011A is
4236 -- type REC (D : integer := 0) is record
4241 -- type T6 is new Rec;
4242 -- function F return T6;
4247 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4250 -- The definition of Q6.U is illegal. However transforming Q6.U into
4252 -- type BaseU is new T6;
4253 -- subtype U is BaseU (Q6.F.I)
4255 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4256 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4257 -- the transformation described above.
4259 -- There is another instance where the above transformation is incorrect.
4263 -- type Base (D : Integer) is tagged null record;
4264 -- procedure P (X : Base);
4266 -- type Der is new Base (2) with null record;
4267 -- procedure P (X : Der);
4270 -- Then the above transformation turns this into
4272 -- type Der_Base is new Base with null record;
4273 -- -- procedure P (X : Base) is implicitly inherited here
4274 -- -- as procedure P (X : Der_Base).
4276 -- subtype Der is Der_Base (2);
4277 -- procedure P (X : Der);
4278 -- -- The overriding of P (X : Der_Base) is illegal since we
4279 -- -- have a parameter conformance problem.
4281 -- To get around this problem, after having semantically processed Der_Base
4282 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4283 -- Discriminant_Constraint from Der so that when parameter conformance is
4284 -- checked when P is overridden, no semantic errors are flagged.
4286 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
4288 -- Regardless of whether we are dealing with a tagged or untagged type
4289 -- we will transform all derived type declarations of the form
4291 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4292 -- type T is new R [with ...];
4294 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4296 -- The reason for such transformation is that it allows us to implement a
4297 -- very clean form of component inheritance as explained below.
4299 -- Note that this transformation is not achieved by direct tree rewriting
4300 -- and manipulation, but rather by redoing the semantic actions that the
4301 -- above transformation will entail. This is done directly in routine
4302 -- Inherit_Components.
4304 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
4306 -- In both tagged and untagged derived types, regular non discriminant
4307 -- components are inherited in the derived type from the parent type. In
4308 -- the absence of discriminants component, inheritance is straightforward
4309 -- as components can simply be copied from the parent.
4310 -- If the parent has discriminants, inheriting components constrained with
4311 -- these discriminants requires caution. Consider the following example:
4313 -- type R (D1, D2 : Positive) is [tagged] record
4314 -- S : String (D1 .. D2);
4317 -- type T1 is new R [with null record];
4318 -- type T2 (X : positive) is new R (1, X) [with null record];
4320 -- As explained in 6. above, T1 is rewritten as
4322 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4324 -- which makes the treatment for T1 and T2 identical.
4326 -- What we want when inheriting S, is that references to D1 and D2 in R are
4327 -- replaced with references to their correct constraints, ie D1 and D2 in
4328 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4329 -- with either discriminant references in the derived type or expressions.
4330 -- This replacement is achieved as follows: before inheriting R's
4331 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4332 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4333 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4334 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4335 -- by String (1 .. X).
4337 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
4339 -- We explain here the rules governing private type extensions relevant to
4340 -- type derivation. These rules are explained on the following example:
4342 -- type D [(...)] is new A [(...)] with private; <-- partial view
4343 -- type D [(...)] is new P [(...)] with null record; <-- full view
4345 -- Type A is called the ancestor subtype of the private extension.
4346 -- Type P is the parent type of the full view of the private extension. It
4347 -- must be A or a type derived from A.
4349 -- The rules concerning the discriminants of private type extensions are
4352 -- o If a private extension inherits known discriminants from the ancestor
4353 -- subtype, then the full view shall also inherit its discriminants from
4354 -- the ancestor subtype and the parent subtype of the full view shall be
4355 -- constrained if and only if the ancestor subtype is constrained.
4357 -- o If a partial view has unknown discriminants, then the full view may
4358 -- define a definite or an indefinite subtype, with or without
4361 -- o If a partial view has neither known nor unknown discriminants, then
4362 -- the full view shall define a definite subtype.
4364 -- o If the ancestor subtype of a private extension has constrained
4365 -- discriminants, then the parent subtype of the full view shall impose a
4366 -- statically matching constraint on those discriminants.
4368 -- This means that only the following forms of private extensions are
4371 -- type D is new A with private; <-- partial view
4372 -- type D is new P with null record; <-- full view
4374 -- If A has no discriminants than P has no discriminants, otherwise P must
4375 -- inherit A's discriminants.
4377 -- type D is new A (...) with private; <-- partial view
4378 -- type D is new P (:::) with null record; <-- full view
4380 -- P must inherit A's discriminants and (...) and (:::) must statically
4383 -- subtype A is R (...);
4384 -- type D is new A with private; <-- partial view
4385 -- type D is new P with null record; <-- full view
4387 -- P must have inherited R's discriminants and must be derived from A or
4388 -- any of its subtypes.
4390 -- type D (..) is new A with private; <-- partial view
4391 -- type D (..) is new P [(:::)] with null record; <-- full view
4393 -- No specific constraints on P's discriminants or constraint (:::).
4394 -- Note that A can be unconstrained, but the parent subtype P must either
4395 -- be constrained or (:::) must be present.
4397 -- type D (..) is new A [(...)] with private; <-- partial view
4398 -- type D (..) is new P [(:::)] with null record; <-- full view
4400 -- P's constraints on A's discriminants must statically match those
4401 -- imposed by (...).
4403 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
4405 -- The full view of a private extension is handled exactly as described
4406 -- above. The model chose for the private view of a private extension
4407 -- is the same for what concerns discriminants (ie they receive the same
4408 -- treatment as in the tagged case). However, the private view of the
4409 -- private extension always inherits the components of the parent base,
4410 -- without replacing any discriminant reference. Strictly speaking this
4411 -- is incorrect. However, Gigi never uses this view to generate code so
4412 -- this is a purely semantic issue. In theory, a set of transformations
4413 -- similar to those given in 5. and 6. above could be applied to private
4414 -- views of private extensions to have the same model of component
4415 -- inheritance as for non private extensions. However, this is not done
4416 -- because it would further complicate private type processing.
4417 -- Semantically speaking, this leaves us in an uncomfortable
4418 -- situation. As an example consider:
4421 -- type R (D : integer) is tagged record
4422 -- S : String (1 .. D);
4424 -- procedure P (X : R);
4425 -- type T is new R (1) with private;
4427 -- type T is new R (1) with null record;
4430 -- This is transformed into:
4433 -- type R (D : integer) is tagged record
4434 -- S : String (1 .. D);
4436 -- procedure P (X : R);
4437 -- type T is new R (1) with private;
4439 -- type BaseT is new R with null record;
4440 -- subtype T is BaseT (1);
4443 -- (strictly speaking the above is incorrect Ada).
4445 -- From the semantic standpoint the private view of private extension T
4446 -- should be flagged as constrained since one can clearly have
4450 -- in a unit withing Pack. However, when deriving subprograms for the
4451 -- private view of private extension T, T must be seen as unconstrained
4452 -- since T has discriminants (this is a constraint of the current
4453 -- subprogram derivation model). Thus, when processing the private view of
4454 -- a private extension such as T, we first mark T as unconstrained, we
4455 -- process it, we perform program derivation and just before returning from
4456 -- Build_Derived_Record_Type we mark T as constrained.
4457 -- ??? Are there are other uncomfortable cases that we will have to
4460 -- 10. RECORD_TYPE_WITH_PRIVATE complications.
4462 -- Types that are derived from a visible record type and have a private
4463 -- extension present other peculiarities. They behave mostly like private
4464 -- types, but if they have primitive operations defined, these will not
4465 -- have the proper signatures for further inheritance, because other
4466 -- primitive operations will use the implicit base that we define for
4467 -- private derivations below. This affect subprogram inheritance (see
4468 -- Derive_Subprograms for details). We also derive the implicit base from
4469 -- the base type of the full view, so that the implicit base is a record
4470 -- type and not another private type, This avoids infinite loops.
4472 procedure Build_Derived_Record_Type
4474 Parent_Type : Entity_Id;
4475 Derived_Type : Entity_Id;
4476 Derive_Subps : Boolean := True)
4478 Loc : constant Source_Ptr := Sloc (N);
4479 Parent_Base : Entity_Id;
4484 Discrim : Entity_Id;
4485 Last_Discrim : Entity_Id;
4487 Discs : Elist_Id := New_Elmt_List;
4488 -- An empty Discs list means that there were no constraints in the
4489 -- subtype indication or that there was an error processing it.
4491 Assoc_List : Elist_Id;
4492 New_Discrs : Elist_Id;
4494 New_Base : Entity_Id;
4496 New_Indic : Node_Id;
4498 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4499 Discriminant_Specs : constant Boolean :=
4500 Present (Discriminant_Specifications (N));
4501 Private_Extension : constant Boolean :=
4502 (Nkind (N) = N_Private_Extension_Declaration);
4504 Constraint_Present : Boolean;
4505 Inherit_Discrims : Boolean := False;
4507 Save_Etype : Entity_Id;
4508 Save_Discr_Constr : Elist_Id;
4509 Save_Next_Entity : Entity_Id;
4512 if Ekind (Parent_Type) = E_Record_Type_With_Private
4513 and then Present (Full_View (Parent_Type))
4514 and then Has_Discriminants (Parent_Type)
4516 Parent_Base := Base_Type (Full_View (Parent_Type));
4518 Parent_Base := Base_Type (Parent_Type);
4521 -- Before we start the previously documented transformations, here is
4522 -- a little fix for size and alignment of tagged types. Normally when
4523 -- we derive type D from type P, we copy the size and alignment of P
4524 -- as the default for D, and in the absence of explicit representation
4525 -- clauses for D, the size and alignment are indeed the same as the
4528 -- But this is wrong for tagged types, since fields may be added,
4529 -- and the default size may need to be larger, and the default
4530 -- alignment may need to be larger.
4532 -- We therefore reset the size and alignment fields in the tagged
4533 -- case. Note that the size and alignment will in any case be at
4534 -- least as large as the parent type (since the derived type has
4535 -- a copy of the parent type in the _parent field)
4538 Init_Size_Align (Derived_Type);
4541 -- STEP 0a: figure out what kind of derived type declaration we have.
4543 if Private_Extension then
4545 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4548 Type_Def := Type_Definition (N);
4550 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4551 -- Parent_Base can be a private type or private extension. However,
4552 -- for tagged types with an extension the newly added fields are
4553 -- visible and hence the Derived_Type is always an E_Record_Type.
4554 -- (except that the parent may have its own private fields).
4555 -- For untagged types we preserve the Ekind of the Parent_Base.
4557 if Present (Record_Extension_Part (Type_Def)) then
4558 Set_Ekind (Derived_Type, E_Record_Type);
4560 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4564 -- Indic can either be an N_Identifier if the subtype indication
4565 -- contains no constraint or an N_Subtype_Indication if the subtype
4566 -- indication has a constraint.
4568 Indic := Subtype_Indication (Type_Def);
4569 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
4571 if Constraint_Present then
4572 if not Has_Discriminants (Parent_Base) then
4574 ("invalid constraint: type has no discriminant",
4575 Constraint (Indic));
4577 Constraint_Present := False;
4578 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4580 elsif Is_Constrained (Parent_Type) then
4582 ("invalid constraint: parent type is already constrained",
4583 Constraint (Indic));
4585 Constraint_Present := False;
4586 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4590 -- STEP 0b: If needed, apply transformation given in point 5. above.
4592 if not Private_Extension
4593 and then Has_Discriminants (Parent_Type)
4594 and then not Discriminant_Specs
4595 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
4597 -- First, we must analyze the constraint (see comment in point 5.).
4599 if Constraint_Present then
4600 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
4602 if Has_Discriminants (Derived_Type)
4603 and then Has_Private_Declaration (Derived_Type)
4604 and then Present (Discriminant_Constraint (Derived_Type))
4606 -- Verify that constraints of the full view conform to those
4607 -- given in partial view.
4613 C1 := First_Elmt (New_Discrs);
4614 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
4616 while Present (C1) and then Present (C2) loop
4618 Fully_Conformant_Expressions (Node (C1), Node (C2))
4621 "constraint not conformant to previous declaration",
4631 -- Insert and analyze the declaration for the unconstrained base type
4633 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
4636 Make_Full_Type_Declaration (Loc,
4637 Defining_Identifier => New_Base,
4639 Make_Derived_Type_Definition (Loc,
4640 Abstract_Present => Abstract_Present (Type_Def),
4641 Subtype_Indication =>
4642 New_Occurrence_Of (Parent_Base, Loc),
4643 Record_Extension_Part =>
4644 Relocate_Node (Record_Extension_Part (Type_Def))));
4646 Set_Parent (New_Decl, Parent (N));
4647 Mark_Rewrite_Insertion (New_Decl);
4648 Insert_Before (N, New_Decl);
4650 -- Note that this call passes False for the Derive_Subps
4651 -- parameter because subprogram derivation is deferred until
4652 -- after creating the subtype (see below).
4655 (New_Decl, Parent_Base, New_Base,
4656 Is_Completion => True, Derive_Subps => False);
4658 -- ??? This needs re-examination to determine whether the
4659 -- above call can simply be replaced by a call to Analyze.
4661 Set_Analyzed (New_Decl);
4663 -- Insert and analyze the declaration for the constrained subtype
4665 if Constraint_Present then
4667 Make_Subtype_Indication (Loc,
4668 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4669 Constraint => Relocate_Node (Constraint (Indic)));
4673 Constr_List : constant List_Id := New_List;
4678 C := First_Elmt (Discriminant_Constraint (Parent_Type));
4679 while Present (C) loop
4682 -- It is safe here to call New_Copy_Tree since
4683 -- Force_Evaluation was called on each constraint in
4684 -- Build_Discriminant_Constraints.
4686 Append (New_Copy_Tree (Expr), To => Constr_List);
4692 Make_Subtype_Indication (Loc,
4693 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4695 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
4700 Make_Subtype_Declaration (Loc,
4701 Defining_Identifier => Derived_Type,
4702 Subtype_Indication => New_Indic));
4706 -- Derivation of subprograms must be delayed until the
4707 -- full subtype has been established to ensure proper
4708 -- overriding of subprograms inherited by full types.
4709 -- If the derivations occurred as part of the call to
4710 -- Build_Derived_Type above, then the check for type
4711 -- conformance would fail because earlier primitive
4712 -- subprograms could still refer to the full type prior
4713 -- the change to the new subtype and hence wouldn't
4714 -- match the new base type created here.
4716 Derive_Subprograms (Parent_Type, Derived_Type);
4718 -- For tagged types the Discriminant_Constraint of the new base itype
4719 -- is inherited from the first subtype so that no subtype conformance
4720 -- problem arise when the first subtype overrides primitive
4721 -- operations inherited by the implicit base type.
4724 Set_Discriminant_Constraint
4725 (New_Base, Discriminant_Constraint (Derived_Type));
4731 -- If we get here Derived_Type will have no discriminants or it will be
4732 -- a discriminated unconstrained base type.
4734 -- STEP 1a: perform preliminary actions/checks for derived tagged types
4737 -- The parent type is frozen for non-private extensions (RM 13.14(7))
4739 if not Private_Extension then
4740 Freeze_Before (N, Parent_Type);
4743 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
4744 and then not Is_Generic_Type (Derived_Type)
4746 if Is_Controlled (Parent_Type) then
4748 ("controlled type must be declared at the library level",
4752 ("type extension at deeper accessibility level than parent",
4758 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
4762 and then GB /= Enclosing_Generic_Body (Parent_Base)
4765 ("parent type of& must not be outside generic body"
4766 & " ('R'M 3.9.1(4))",
4767 Indic, Derived_Type);
4773 -- STEP 1b : preliminary cleanup of the full view of private types
4775 -- If the type is already marked as having discriminants, then it's the
4776 -- completion of a private type or private extension and we need to
4777 -- retain the discriminants from the partial view if the current
4778 -- declaration has Discriminant_Specifications so that we can verify
4779 -- conformance. However, we must remove any existing components that
4780 -- were inherited from the parent (and attached in Copy_And_Swap)
4781 -- because the full type inherits all appropriate components anyway, and
4782 -- we don't want the partial view's components interfering.
4784 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
4785 Discrim := First_Discriminant (Derived_Type);
4787 Last_Discrim := Discrim;
4788 Next_Discriminant (Discrim);
4789 exit when No (Discrim);
4792 Set_Last_Entity (Derived_Type, Last_Discrim);
4794 -- In all other cases wipe out the list of inherited components (even
4795 -- inherited discriminants), it will be properly rebuilt here.
4798 Set_First_Entity (Derived_Type, Empty);
4799 Set_Last_Entity (Derived_Type, Empty);
4802 -- STEP 1c: Initialize some flags for the Derived_Type
4804 -- The following flags must be initialized here so that
4805 -- Process_Discriminants can check that discriminants of tagged types
4806 -- do not have a default initial value and that access discriminants
4807 -- are only specified for limited records. For completeness, these
4808 -- flags are also initialized along with all the other flags below.
4810 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4811 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
4813 -- STEP 2a: process discriminants of derived type if any.
4815 New_Scope (Derived_Type);
4817 if Discriminant_Specs then
4818 Set_Has_Unknown_Discriminants (Derived_Type, False);
4820 -- The following call initializes fields Has_Discriminants and
4821 -- Discriminant_Constraint, unless we are processing the completion
4822 -- of a private type declaration.
4824 Check_Or_Process_Discriminants (N, Derived_Type);
4826 -- For non-tagged types the constraint on the Parent_Type must be
4827 -- present and is used to rename the discriminants.
4829 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
4830 Error_Msg_N ("untagged parent must have discriminants", Indic);
4832 elsif not Is_Tagged and then not Constraint_Present then
4834 ("discriminant constraint needed for derived untagged records",
4837 -- Otherwise the parent subtype must be constrained unless we have a
4838 -- private extension.
4840 elsif not Constraint_Present
4841 and then not Private_Extension
4842 and then not Is_Constrained (Parent_Type)
4845 ("unconstrained type not allowed in this context", Indic);
4847 elsif Constraint_Present then
4848 -- The following call sets the field Corresponding_Discriminant
4849 -- for the discriminants in the Derived_Type.
4851 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
4853 -- For untagged types all new discriminants must rename
4854 -- discriminants in the parent. For private extensions new
4855 -- discriminants cannot rename old ones (implied by [7.3(13)]).
4857 Discrim := First_Discriminant (Derived_Type);
4859 while Present (Discrim) loop
4861 and then not Present (Corresponding_Discriminant (Discrim))
4864 ("new discriminants must constrain old ones", Discrim);
4866 elsif Private_Extension
4867 and then Present (Corresponding_Discriminant (Discrim))
4870 ("only static constraints allowed for parent"
4871 & " discriminants in the partial view", Indic);
4875 -- If a new discriminant is used in the constraint,
4876 -- then its subtype must be statically compatible
4877 -- with the parent discriminant's subtype (3.7(15)).
4879 if Present (Corresponding_Discriminant (Discrim))
4881 not Subtypes_Statically_Compatible
4883 Etype (Corresponding_Discriminant (Discrim)))
4886 ("subtype must be compatible with parent discriminant",
4890 Next_Discriminant (Discrim);
4894 -- STEP 2b: No new discriminants, inherit discriminants if any
4897 if Private_Extension then
4898 Set_Has_Unknown_Discriminants
4899 (Derived_Type, Has_Unknown_Discriminants (Parent_Type)
4900 or else Unknown_Discriminants_Present (N));
4902 Set_Has_Unknown_Discriminants
4903 (Derived_Type, Has_Unknown_Discriminants (Parent_Type));
4906 if not Has_Unknown_Discriminants (Derived_Type)
4907 and then Has_Discriminants (Parent_Type)
4909 Inherit_Discrims := True;
4910 Set_Has_Discriminants
4911 (Derived_Type, True);
4912 Set_Discriminant_Constraint
4913 (Derived_Type, Discriminant_Constraint (Parent_Base));
4916 -- The following test is true for private types (remember
4917 -- transformation 5. is not applied to those) and in an error
4920 if Constraint_Present then
4921 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
4924 -- For now mark a new derived type as constrained only if it has no
4925 -- discriminants. At the end of Build_Derived_Record_Type we properly
4926 -- set this flag in the case of private extensions. See comments in
4927 -- point 9. just before body of Build_Derived_Record_Type.
4931 not (Inherit_Discrims
4932 or else Has_Unknown_Discriminants (Derived_Type)));
4935 -- STEP 3: initialize fields of derived type.
4937 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4938 Set_Stored_Constraint (Derived_Type, No_Elist);
4940 -- Fields inherited from the Parent_Type
4943 (Derived_Type, Einfo.Discard_Names (Parent_Type));
4944 Set_Has_Specified_Layout
4945 (Derived_Type, Has_Specified_Layout (Parent_Type));
4946 Set_Is_Limited_Composite
4947 (Derived_Type, Is_Limited_Composite (Parent_Type));
4948 Set_Is_Limited_Record
4949 (Derived_Type, Is_Limited_Record (Parent_Type));
4950 Set_Is_Private_Composite
4951 (Derived_Type, Is_Private_Composite (Parent_Type));
4953 -- Fields inherited from the Parent_Base
4955 Set_Has_Controlled_Component
4956 (Derived_Type, Has_Controlled_Component (Parent_Base));
4957 Set_Has_Non_Standard_Rep
4958 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4959 Set_Has_Primitive_Operations
4960 (Derived_Type, Has_Primitive_Operations (Parent_Base));
4962 -- Direct controlled types do not inherit Finalize_Storage_Only flag
4964 if not Is_Controlled (Parent_Type) then
4965 Set_Finalize_Storage_Only
4966 (Derived_Type, Finalize_Storage_Only (Parent_Type));
4969 -- Set fields for private derived types.
4971 if Is_Private_Type (Derived_Type) then
4972 Set_Depends_On_Private (Derived_Type, True);
4973 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4975 -- Inherit fields from non private record types. If this is the
4976 -- completion of a derivation from a private type, the parent itself
4977 -- is private, and the attributes come from its full view, which must
4981 if Is_Private_Type (Parent_Base)
4982 and then not Is_Record_Type (Parent_Base)
4984 Set_Component_Alignment
4985 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
4987 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
4989 Set_Component_Alignment
4990 (Derived_Type, Component_Alignment (Parent_Base));
4993 (Derived_Type, C_Pass_By_Copy (Parent_Base));
4997 -- Set fields for tagged types
5000 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
5002 -- All tagged types defined in Ada.Finalization are controlled
5004 if Chars (Scope (Derived_Type)) = Name_Finalization
5005 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
5006 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
5008 Set_Is_Controlled (Derived_Type);
5010 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
5013 Make_Class_Wide_Type (Derived_Type);
5014 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
5016 if Has_Discriminants (Derived_Type)
5017 and then Constraint_Present
5019 Set_Stored_Constraint
5020 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
5024 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
5025 Set_Has_Non_Standard_Rep
5026 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
5029 -- STEP 4: Inherit components from the parent base and constrain them.
5030 -- Apply the second transformation described in point 6. above.
5032 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
5033 or else not Has_Discriminants (Parent_Type)
5034 or else not Is_Constrained (Parent_Type)
5038 Constrs := Discriminant_Constraint (Parent_Type);
5041 Assoc_List := Inherit_Components (N,
5042 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
5044 -- STEP 5a: Copy the parent record declaration for untagged types
5046 if not Is_Tagged then
5048 -- Discriminant_Constraint (Derived_Type) has been properly
5049 -- constructed. Save it and temporarily set it to Empty because we do
5050 -- not want the call to New_Copy_Tree below to mess this list.
5052 if Has_Discriminants (Derived_Type) then
5053 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
5054 Set_Discriminant_Constraint (Derived_Type, No_Elist);
5056 Save_Discr_Constr := No_Elist;
5059 -- Save the Etype field of Derived_Type. It is correctly set now, but
5060 -- the call to New_Copy tree may remap it to point to itself, which
5061 -- is not what we want. Ditto for the Next_Entity field.
5063 Save_Etype := Etype (Derived_Type);
5064 Save_Next_Entity := Next_Entity (Derived_Type);
5066 -- Assoc_List maps all stored discriminants in the Parent_Base to
5067 -- stored discriminants in the Derived_Type. It is fundamental that
5068 -- no types or itypes with discriminants other than the stored
5069 -- discriminants appear in the entities declared inside
5070 -- Derived_Type. Gigi won't like it.
5074 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
5076 -- Restore the fields saved prior to the New_Copy_Tree call
5077 -- and compute the stored constraint.
5079 Set_Etype (Derived_Type, Save_Etype);
5080 Set_Next_Entity (Derived_Type, Save_Next_Entity);
5082 if Has_Discriminants (Derived_Type) then
5083 Set_Discriminant_Constraint
5084 (Derived_Type, Save_Discr_Constr);
5085 Set_Stored_Constraint
5086 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
5087 Replace_Components (Derived_Type, New_Decl);
5090 -- Insert the new derived type declaration
5092 Rewrite (N, New_Decl);
5094 -- STEP 5b: Complete the processing for record extensions in generics
5096 -- There is no completion for record extensions declared in the
5097 -- parameter part of a generic, so we need to complete processing for
5098 -- these generic record extensions here. The Record_Type_Definition call
5099 -- will change the Ekind of the components from E_Void to E_Component.
5101 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
5102 Record_Type_Definition (Empty, Derived_Type);
5104 -- STEP 5c: Process the record extension for non private tagged types.
5106 elsif not Private_Extension then
5107 -- Add the _parent field in the derived type.
5109 Expand_Derived_Record (Derived_Type, Type_Def);
5111 -- Analyze the record extension
5113 Record_Type_Definition
5114 (Record_Extension_Part (Type_Def), Derived_Type);
5119 if Etype (Derived_Type) = Any_Type then
5123 -- Set delayed freeze and then derive subprograms, we need to do
5124 -- this in this order so that derived subprograms inherit the
5125 -- derived freeze if necessary.
5127 Set_Has_Delayed_Freeze (Derived_Type);
5128 if Derive_Subps then
5129 Derive_Subprograms (Parent_Type, Derived_Type);
5132 -- If we have a private extension which defines a constrained derived
5133 -- type mark as constrained here after we have derived subprograms. See
5134 -- comment on point 9. just above the body of Build_Derived_Record_Type.
5136 if Private_Extension and then Inherit_Discrims then
5137 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
5138 Set_Is_Constrained (Derived_Type, True);
5139 Set_Discriminant_Constraint (Derived_Type, Discs);
5141 elsif Is_Constrained (Parent_Type) then
5143 (Derived_Type, True);
5144 Set_Discriminant_Constraint
5145 (Derived_Type, Discriminant_Constraint (Parent_Type));
5149 end Build_Derived_Record_Type;
5151 ------------------------
5152 -- Build_Derived_Type --
5153 ------------------------
5155 procedure Build_Derived_Type
5157 Parent_Type : Entity_Id;
5158 Derived_Type : Entity_Id;
5159 Is_Completion : Boolean;
5160 Derive_Subps : Boolean := True)
5162 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5165 -- Set common attributes
5167 Set_Scope (Derived_Type, Current_Scope);
5169 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5170 Set_Etype (Derived_Type, Parent_Base);
5171 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
5173 Set_Size_Info (Derived_Type, Parent_Type);
5174 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5175 Set_Convention (Derived_Type, Convention (Parent_Type));
5176 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
5178 -- The derived type inherits the representation clauses of the parent.
5179 -- However, for a private type that is completed by a derivation, there
5180 -- may be operation attributes that have been specified already (stream
5181 -- attributes and External_Tag) and those must be provided. Finally,
5182 -- if the partial view is a private extension, the representation items
5183 -- of the parent have been inherited already, and should not be chained
5184 -- twice to the derived type.
5186 if Is_Tagged_Type (Parent_Type)
5187 and then Present (First_Rep_Item (Derived_Type))
5189 -- The existing items are either operational items or items inherited
5190 -- from a private extension declaration.
5193 Rep : Node_Id := First_Rep_Item (Derived_Type);
5194 Found : Boolean := False;
5197 while Present (Rep) loop
5198 if Rep = First_Rep_Item (Parent_Type) then
5202 Rep := Next_Rep_Item (Rep);
5208 (First_Rep_Item (Derived_Type), First_Rep_Item (Parent_Type));
5213 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
5216 case Ekind (Parent_Type) is
5217 when Numeric_Kind =>
5218 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
5221 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
5225 | Class_Wide_Kind =>
5226 Build_Derived_Record_Type
5227 (N, Parent_Type, Derived_Type, Derive_Subps);
5230 when Enumeration_Kind =>
5231 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5234 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5236 when Incomplete_Or_Private_Kind =>
5237 Build_Derived_Private_Type
5238 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5240 -- For discriminated types, the derivation includes deriving
5241 -- primitive operations. For others it is done below.
5243 if Is_Tagged_Type (Parent_Type)
5244 or else Has_Discriminants (Parent_Type)
5245 or else (Present (Full_View (Parent_Type))
5246 and then Has_Discriminants (Full_View (Parent_Type)))
5251 when Concurrent_Kind =>
5252 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5255 raise Program_Error;
5258 if Etype (Derived_Type) = Any_Type then
5262 -- Set delayed freeze and then derive subprograms, we need to do
5263 -- this in this order so that derived subprograms inherit the
5264 -- derived freeze if necessary.
5266 Set_Has_Delayed_Freeze (Derived_Type);
5267 if Derive_Subps then
5268 Derive_Subprograms (Parent_Type, Derived_Type);
5271 Set_Has_Primitive_Operations
5272 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5273 end Build_Derived_Type;
5275 -----------------------
5276 -- Build_Discriminal --
5277 -----------------------
5279 procedure Build_Discriminal (Discrim : Entity_Id) is
5280 D_Minal : Entity_Id;
5281 CR_Disc : Entity_Id;
5284 -- A discriminal has the same names as the discriminant.
5286 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5288 Set_Ekind (D_Minal, E_In_Parameter);
5289 Set_Mechanism (D_Minal, Default_Mechanism);
5290 Set_Etype (D_Minal, Etype (Discrim));
5292 Set_Discriminal (Discrim, D_Minal);
5293 Set_Discriminal_Link (D_Minal, Discrim);
5295 -- For task types, build at once the discriminants of the corresponding
5296 -- record, which are needed if discriminants are used in entry defaults
5297 -- and in family bounds.
5299 if Is_Concurrent_Type (Current_Scope)
5300 or else Is_Limited_Type (Current_Scope)
5302 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5304 Set_Ekind (CR_Disc, E_In_Parameter);
5305 Set_Mechanism (CR_Disc, Default_Mechanism);
5306 Set_Etype (CR_Disc, Etype (Discrim));
5307 Set_CR_Discriminant (Discrim, CR_Disc);
5309 end Build_Discriminal;
5311 ------------------------------------
5312 -- Build_Discriminant_Constraints --
5313 ------------------------------------
5315 function Build_Discriminant_Constraints
5318 Derived_Def : Boolean := False) return Elist_Id
5320 C : constant Node_Id := Constraint (Def);
5321 Nb_Discr : constant Nat := Number_Discriminants (T);
5322 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5323 -- Saves the expression corresponding to a given discriminant in T.
5325 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5326 -- Return the Position number within array Discr_Expr of a discriminant
5327 -- D within the discriminant list of the discriminated type T.
5333 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5337 Disc := First_Discriminant (T);
5338 for J in Discr_Expr'Range loop
5343 Next_Discriminant (Disc);
5346 -- Note: Since this function is called on discriminants that are
5347 -- known to belong to the discriminated type, falling through the
5348 -- loop with no match signals an internal compiler error.
5350 raise Program_Error;
5353 -- Declarations local to Build_Discriminant_Constraints
5357 Elist : constant Elist_Id := New_Elmt_List;
5365 Discrim_Present : Boolean := False;
5367 -- Start of processing for Build_Discriminant_Constraints
5370 -- The following loop will process positional associations only.
5371 -- For a positional association, the (single) discriminant is
5372 -- implicitly specified by position, in textual order (RM 3.7.2).
5374 Discr := First_Discriminant (T);
5375 Constr := First (Constraints (C));
5377 for D in Discr_Expr'Range loop
5378 exit when Nkind (Constr) = N_Discriminant_Association;
5381 Error_Msg_N ("too few discriminants given in constraint", C);
5382 return New_Elmt_List;
5384 elsif Nkind (Constr) = N_Range
5385 or else (Nkind (Constr) = N_Attribute_Reference
5387 Attribute_Name (Constr) = Name_Range)
5390 ("a range is not a valid discriminant constraint", Constr);
5391 Discr_Expr (D) := Error;
5394 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5395 Discr_Expr (D) := Constr;
5398 Next_Discriminant (Discr);
5402 if No (Discr) and then Present (Constr) then
5403 Error_Msg_N ("too many discriminants given in constraint", Constr);
5404 return New_Elmt_List;
5407 -- Named associations can be given in any order, but if both positional
5408 -- and named associations are used in the same discriminant constraint,
5409 -- then positional associations must occur first, at their normal
5410 -- position. Hence once a named association is used, the rest of the
5411 -- discriminant constraint must use only named associations.
5413 while Present (Constr) loop
5415 -- Positional association forbidden after a named association.
5417 if Nkind (Constr) /= N_Discriminant_Association then
5418 Error_Msg_N ("positional association follows named one", Constr);
5419 return New_Elmt_List;
5421 -- Otherwise it is a named association
5424 -- E records the type of the discriminants in the named
5425 -- association. All the discriminants specified in the same name
5426 -- association must have the same type.
5430 -- Search the list of discriminants in T to see if the simple name
5431 -- given in the constraint matches any of them.
5433 Id := First (Selector_Names (Constr));
5434 while Present (Id) loop
5437 -- If Original_Discriminant is present, we are processing a
5438 -- generic instantiation and this is an instance node. We need
5439 -- to find the name of the corresponding discriminant in the
5440 -- actual record type T and not the name of the discriminant in
5441 -- the generic formal. Example:
5444 -- type G (D : int) is private;
5446 -- subtype W is G (D => 1);
5448 -- type Rec (X : int) is record ... end record;
5449 -- package Q is new P (G => Rec);
5451 -- At the point of the instantiation, formal type G is Rec
5452 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5453 -- which really looks like "subtype W is Rec (D => 1);" at
5454 -- the point of instantiation, we want to find the discriminant
5455 -- that corresponds to D in Rec, ie X.
5457 if Present (Original_Discriminant (Id)) then
5458 Discr := Find_Corresponding_Discriminant (Id, T);
5462 Discr := First_Discriminant (T);
5463 while Present (Discr) loop
5464 if Chars (Discr) = Chars (Id) then
5469 Next_Discriminant (Discr);
5473 Error_Msg_N ("& does not match any discriminant", Id);
5474 return New_Elmt_List;
5476 -- The following is only useful for the benefit of generic
5477 -- instances but it does not interfere with other
5478 -- processing for the non-generic case so we do it in all
5479 -- cases (for generics this statement is executed when
5480 -- processing the generic definition, see comment at the
5481 -- beginning of this if statement).
5484 Set_Original_Discriminant (Id, Discr);
5488 Position := Pos_Of_Discr (T, Discr);
5490 if Present (Discr_Expr (Position)) then
5491 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5494 -- Each discriminant specified in the same named association
5495 -- must be associated with a separate copy of the
5496 -- corresponding expression.
5498 if Present (Next (Id)) then
5499 Expr := New_Copy_Tree (Expression (Constr));
5500 Set_Parent (Expr, Parent (Expression (Constr)));
5502 Expr := Expression (Constr);
5505 Discr_Expr (Position) := Expr;
5506 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
5509 -- A discriminant association with more than one discriminant
5510 -- name is only allowed if the named discriminants are all of
5511 -- the same type (RM 3.7.1(8)).
5514 E := Base_Type (Etype (Discr));
5516 elsif Base_Type (Etype (Discr)) /= E then
5518 ("all discriminants in an association " &
5519 "must have the same type", Id);
5529 -- A discriminant constraint must provide exactly one value for each
5530 -- discriminant of the type (RM 3.7.1(8)).
5532 for J in Discr_Expr'Range loop
5533 if No (Discr_Expr (J)) then
5534 Error_Msg_N ("too few discriminants given in constraint", C);
5535 return New_Elmt_List;
5539 -- Determine if there are discriminant expressions in the constraint.
5541 for J in Discr_Expr'Range loop
5542 if Denotes_Discriminant (Discr_Expr (J), Check_Protected => True) then
5543 Discrim_Present := True;
5547 -- Build an element list consisting of the expressions given in the
5548 -- discriminant constraint and apply the appropriate range
5549 -- checks. The list is constructed after resolving any named
5550 -- discriminant associations and therefore the expressions appear in
5551 -- the textual order of the discriminants.
5553 Discr := First_Discriminant (T);
5554 for J in Discr_Expr'Range loop
5555 if Discr_Expr (J) /= Error then
5557 Append_Elmt (Discr_Expr (J), Elist);
5559 -- If any of the discriminant constraints is given by a
5560 -- discriminant and we are in a derived type declaration we
5561 -- have a discriminant renaming. Establish link between new
5562 -- and old discriminant.
5564 if Denotes_Discriminant (Discr_Expr (J)) then
5566 Set_Corresponding_Discriminant
5567 (Entity (Discr_Expr (J)), Discr);
5570 -- Force the evaluation of non-discriminant expressions.
5571 -- If we have found a discriminant in the constraint 3.4(26)
5572 -- and 3.8(18) demand that no range checks are performed are
5573 -- after evaluation. If the constraint is for a component
5574 -- definition that has a per-object constraint, expressions are
5575 -- evaluated but not checked either. In all other cases perform
5579 if Discrim_Present then
5582 elsif Nkind (Parent (Def)) = N_Component_Declaration
5584 Has_Per_Object_Constraint
5585 (Defining_Identifier (Parent (Def)))
5590 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
5593 Force_Evaluation (Discr_Expr (J));
5596 -- Check that the designated type of an access discriminant's
5597 -- expression is not a class-wide type unless the discriminant's
5598 -- designated type is also class-wide.
5600 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
5601 and then not Is_Class_Wide_Type
5602 (Designated_Type (Etype (Discr)))
5603 and then Etype (Discr_Expr (J)) /= Any_Type
5604 and then Is_Class_Wide_Type
5605 (Designated_Type (Etype (Discr_Expr (J))))
5607 Wrong_Type (Discr_Expr (J), Etype (Discr));
5611 Next_Discriminant (Discr);
5615 end Build_Discriminant_Constraints;
5617 ---------------------------------
5618 -- Build_Discriminated_Subtype --
5619 ---------------------------------
5621 procedure Build_Discriminated_Subtype
5625 Related_Nod : Node_Id;
5626 For_Access : Boolean := False)
5628 Has_Discrs : constant Boolean := Has_Discriminants (T);
5629 Constrained : constant Boolean
5631 and then not Is_Empty_Elmt_List (Elist)
5632 and then not Is_Class_Wide_Type (T))
5633 or else Is_Constrained (T);
5636 if Ekind (T) = E_Record_Type then
5638 Set_Ekind (Def_Id, E_Private_Subtype);
5639 Set_Is_For_Access_Subtype (Def_Id, True);
5641 Set_Ekind (Def_Id, E_Record_Subtype);
5644 elsif Ekind (T) = E_Task_Type then
5645 Set_Ekind (Def_Id, E_Task_Subtype);
5647 elsif Ekind (T) = E_Protected_Type then
5648 Set_Ekind (Def_Id, E_Protected_Subtype);
5650 elsif Is_Private_Type (T) then
5651 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
5653 elsif Is_Class_Wide_Type (T) then
5654 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
5657 -- Incomplete type. Attach subtype to list of dependents, to be
5658 -- completed with full view of parent type.
5660 Set_Ekind (Def_Id, Ekind (T));
5661 Append_Elmt (Def_Id, Private_Dependents (T));
5664 Set_Etype (Def_Id, T);
5665 Init_Size_Align (Def_Id);
5666 Set_Has_Discriminants (Def_Id, Has_Discrs);
5667 Set_Is_Constrained (Def_Id, Constrained);
5669 Set_First_Entity (Def_Id, First_Entity (T));
5670 Set_Last_Entity (Def_Id, Last_Entity (T));
5671 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
5673 if Is_Tagged_Type (T) then
5674 Set_Is_Tagged_Type (Def_Id);
5675 Make_Class_Wide_Type (Def_Id);
5678 Set_Stored_Constraint (Def_Id, No_Elist);
5681 Set_Discriminant_Constraint (Def_Id, Elist);
5682 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
5685 if Is_Tagged_Type (T) then
5686 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
5687 Set_Is_Abstract (Def_Id, Is_Abstract (T));
5690 -- Subtypes introduced by component declarations do not need to be
5691 -- marked as delayed, and do not get freeze nodes, because the semantics
5692 -- verifies that the parents of the subtypes are frozen before the
5693 -- enclosing record is frozen.
5695 if not Is_Type (Scope (Def_Id)) then
5696 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
5698 if Is_Private_Type (T)
5699 and then Present (Full_View (T))
5701 Conditional_Delay (Def_Id, Full_View (T));
5703 Conditional_Delay (Def_Id, T);
5707 if Is_Record_Type (T) then
5708 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
5711 and then not Is_Empty_Elmt_List (Elist)
5712 and then not For_Access
5714 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
5715 elsif not For_Access then
5716 Set_Cloned_Subtype (Def_Id, T);
5720 end Build_Discriminated_Subtype;
5722 ------------------------
5723 -- Build_Scalar_Bound --
5724 ------------------------
5726 function Build_Scalar_Bound
5729 Der_T : Entity_Id) return Node_Id
5731 New_Bound : Entity_Id;
5734 -- Note: not clear why this is needed, how can the original bound
5735 -- be unanalyzed at this point? and if it is, what business do we
5736 -- have messing around with it? and why is the base type of the
5737 -- parent type the right type for the resolution. It probably is
5738 -- not! It is OK for the new bound we are creating, but not for
5739 -- the old one??? Still if it never happens, no problem!
5741 Analyze_And_Resolve (Bound, Base_Type (Par_T));
5743 if Nkind (Bound) = N_Integer_Literal
5744 or else Nkind (Bound) = N_Real_Literal
5746 New_Bound := New_Copy (Bound);
5747 Set_Etype (New_Bound, Der_T);
5748 Set_Analyzed (New_Bound);
5750 elsif Is_Entity_Name (Bound) then
5751 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
5753 -- The following is almost certainly wrong. What business do we have
5754 -- relocating a node (Bound) that is presumably still attached to
5755 -- the tree elsewhere???
5758 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
5761 Set_Etype (New_Bound, Der_T);
5763 end Build_Scalar_Bound;
5765 --------------------------------
5766 -- Build_Underlying_Full_View --
5767 --------------------------------
5769 procedure Build_Underlying_Full_View
5774 Loc : constant Source_Ptr := Sloc (N);
5775 Subt : constant Entity_Id :=
5776 Make_Defining_Identifier
5777 (Loc, New_External_Name (Chars (Typ), 'S'));
5785 if Nkind (N) = N_Full_Type_Declaration then
5786 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
5788 -- ??? ??? is this assert right, I assume so otherwise Constr
5789 -- would not be defined below (this used to be an elsif)
5791 else pragma Assert (Nkind (N) = N_Subtype_Declaration);
5792 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
5795 -- If the constraint has discriminant associations, the discriminant
5796 -- entity is already set, but it denotes a discriminant of the new
5797 -- type, not the original parent, so it must be found anew.
5799 C := First (Constraints (Constr));
5801 while Present (C) loop
5803 if Nkind (C) = N_Discriminant_Association then
5804 Id := First (Selector_Names (C));
5806 while Present (Id) loop
5807 Set_Original_Discriminant (Id, Empty);
5815 Indic := Make_Subtype_Declaration (Loc,
5816 Defining_Identifier => Subt,
5817 Subtype_Indication =>
5818 Make_Subtype_Indication (Loc,
5819 Subtype_Mark => New_Reference_To (Par, Loc),
5820 Constraint => New_Copy_Tree (Constr)));
5822 Insert_Before (N, Indic);
5824 Set_Underlying_Full_View (Typ, Full_View (Subt));
5825 end Build_Underlying_Full_View;
5827 -------------------------------
5828 -- Check_Abstract_Overriding --
5829 -------------------------------
5831 procedure Check_Abstract_Overriding (T : Entity_Id) is
5838 Op_List := Primitive_Operations (T);
5840 -- Loop to check primitive operations
5842 Elmt := First_Elmt (Op_List);
5843 while Present (Elmt) loop
5844 Subp := Node (Elmt);
5846 -- Special exception, do not complain about failure to
5847 -- override _Input and _Output, since we always provide
5848 -- automatic overridings for these subprograms.
5850 if Is_Abstract (Subp)
5851 and then not Is_TSS (Subp, TSS_Stream_Input)
5852 and then not Is_TSS (Subp, TSS_Stream_Output)
5853 and then not Is_Abstract (T)
5855 if Present (Alias (Subp)) then
5856 -- Only perform the check for a derived subprogram when
5857 -- the type has an explicit record extension. This avoids
5858 -- incorrectly flagging abstract subprograms for the case
5859 -- of a type without an extension derived from a formal type
5860 -- with a tagged actual (can occur within a private part).
5862 Type_Def := Type_Definition (Parent (T));
5863 if Nkind (Type_Def) = N_Derived_Type_Definition
5864 and then Present (Record_Extension_Part (Type_Def))
5867 ("type must be declared abstract or & overridden",
5872 ("abstract subprogram not allowed for type&",
5875 ("nonabstract type has abstract subprogram&",
5882 end Check_Abstract_Overriding;
5884 ------------------------------------------------
5885 -- Check_Access_Discriminant_Requires_Limited --
5886 ------------------------------------------------
5888 procedure Check_Access_Discriminant_Requires_Limited
5893 -- A discriminant_specification for an access discriminant
5894 -- shall appear only in the declaration for a task or protected
5895 -- type, or for a type with the reserved word 'limited' in
5896 -- its definition or in one of its ancestors. (RM 3.7(10))
5898 if Nkind (Discriminant_Type (D)) = N_Access_Definition
5899 and then not Is_Concurrent_Type (Current_Scope)
5900 and then not Is_Concurrent_Record_Type (Current_Scope)
5901 and then not Is_Limited_Record (Current_Scope)
5902 and then Ekind (Current_Scope) /= E_Limited_Private_Type
5905 ("access discriminants allowed only for limited types", Loc);
5907 end Check_Access_Discriminant_Requires_Limited;
5909 -----------------------------------
5910 -- Check_Aliased_Component_Types --
5911 -----------------------------------
5913 procedure Check_Aliased_Component_Types (T : Entity_Id) is
5917 -- ??? Also need to check components of record extensions,
5918 -- but not components of protected types (which are always
5921 if not Is_Limited_Type (T) then
5922 if Ekind (T) = E_Record_Type then
5923 C := First_Component (T);
5924 while Present (C) loop
5926 and then Has_Discriminants (Etype (C))
5927 and then not Is_Constrained (Etype (C))
5928 and then not In_Instance
5931 ("aliased component must be constrained ('R'M 3.6(11))",
5938 elsif Ekind (T) = E_Array_Type then
5939 if Has_Aliased_Components (T)
5940 and then Has_Discriminants (Component_Type (T))
5941 and then not Is_Constrained (Component_Type (T))
5942 and then not In_Instance
5945 ("aliased component type must be constrained ('R'M 3.6(11))",
5950 end Check_Aliased_Component_Types;
5952 ----------------------
5953 -- Check_Completion --
5954 ----------------------
5956 procedure Check_Completion (Body_Id : Node_Id := Empty) is
5959 procedure Post_Error;
5960 -- Post error message for lack of completion for entity E
5966 procedure Post_Error is
5968 if not Comes_From_Source (E) then
5970 if Ekind (E) = E_Task_Type
5971 or else Ekind (E) = E_Protected_Type
5973 -- It may be an anonymous protected type created for a
5974 -- single variable. Post error on variable, if present.
5980 Var := First_Entity (Current_Scope);
5982 while Present (Var) loop
5983 exit when Etype (Var) = E
5984 and then Comes_From_Source (Var);
5989 if Present (Var) then
5996 -- If a generated entity has no completion, then either previous
5997 -- semantic errors have disabled the expansion phase, or else
5998 -- we had missing subunits, or else we are compiling without expan-
5999 -- sion, or else something is very wrong.
6001 if not Comes_From_Source (E) then
6003 (Serious_Errors_Detected > 0
6004 or else Configurable_Run_Time_Violations > 0
6005 or else Subunits_Missing
6006 or else not Expander_Active);
6009 -- Here for source entity
6012 -- Here if no body to post the error message, so we post the error
6013 -- on the declaration that has no completion. This is not really
6014 -- the right place to post it, think about this later ???
6016 if No (Body_Id) then
6019 ("missing full declaration for }", Parent (E), E);
6022 ("missing body for &", Parent (E), E);
6025 -- Package body has no completion for a declaration that appears
6026 -- in the corresponding spec. Post error on the body, with a
6027 -- reference to the non-completed declaration.
6030 Error_Msg_Sloc := Sloc (E);
6034 ("missing full declaration for }!", Body_Id, E);
6036 elsif Is_Overloadable (E)
6037 and then Current_Entity_In_Scope (E) /= E
6039 -- It may be that the completion is mistyped and appears
6040 -- as a distinct overloading of the entity.
6043 Candidate : constant Entity_Id :=
6044 Current_Entity_In_Scope (E);
6045 Decl : constant Node_Id :=
6046 Unit_Declaration_Node (Candidate);
6049 if Is_Overloadable (Candidate)
6050 and then Ekind (Candidate) = Ekind (E)
6051 and then Nkind (Decl) = N_Subprogram_Body
6052 and then Acts_As_Spec (Decl)
6054 Check_Type_Conformant (Candidate, E);
6057 Error_Msg_NE ("missing body for & declared#!",
6062 Error_Msg_NE ("missing body for & declared#!",
6069 -- Start processing for Check_Completion
6072 E := First_Entity (Current_Scope);
6073 while Present (E) loop
6074 if Is_Intrinsic_Subprogram (E) then
6077 -- The following situation requires special handling: a child
6078 -- unit that appears in the context clause of the body of its
6081 -- procedure Parent.Child (...);
6083 -- with Parent.Child;
6084 -- package body Parent is
6086 -- Here Parent.Child appears as a local entity, but should not
6087 -- be flagged as requiring completion, because it is a
6088 -- compilation unit.
6090 elsif Ekind (E) = E_Function
6091 or else Ekind (E) = E_Procedure
6092 or else Ekind (E) = E_Generic_Function
6093 or else Ekind (E) = E_Generic_Procedure
6095 if not Has_Completion (E)
6096 and then not Is_Abstract (E)
6097 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
6099 and then Chars (E) /= Name_uSize
6104 elsif Is_Entry (E) then
6105 if not Has_Completion (E) and then
6106 (Ekind (Scope (E)) = E_Protected_Object
6107 or else Ekind (Scope (E)) = E_Protected_Type)
6112 elsif Is_Package (E) then
6113 if Unit_Requires_Body (E) then
6114 if not Has_Completion (E)
6115 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
6121 elsif not Is_Child_Unit (E) then
6122 May_Need_Implicit_Body (E);
6125 elsif Ekind (E) = E_Incomplete_Type
6126 and then No (Underlying_Type (E))
6130 elsif (Ekind (E) = E_Task_Type or else
6131 Ekind (E) = E_Protected_Type)
6132 and then not Has_Completion (E)
6136 -- A single task declared in the current scope is
6137 -- a constant, verify that the body of its anonymous
6138 -- type is in the same scope. If the task is defined
6139 -- elsewhere, this may be a renaming declaration for
6140 -- which no completion is needed.
6142 elsif Ekind (E) = E_Constant
6143 and then Ekind (Etype (E)) = E_Task_Type
6144 and then not Has_Completion (Etype (E))
6145 and then Scope (Etype (E)) = Current_Scope
6149 elsif Ekind (E) = E_Protected_Object
6150 and then not Has_Completion (Etype (E))
6154 elsif Ekind (E) = E_Record_Type then
6155 if Is_Tagged_Type (E) then
6156 Check_Abstract_Overriding (E);
6159 Check_Aliased_Component_Types (E);
6161 elsif Ekind (E) = E_Array_Type then
6162 Check_Aliased_Component_Types (E);
6168 end Check_Completion;
6170 ----------------------------
6171 -- Check_Delta_Expression --
6172 ----------------------------
6174 procedure Check_Delta_Expression (E : Node_Id) is
6176 if not (Is_Real_Type (Etype (E))) then
6177 Wrong_Type (E, Any_Real);
6179 elsif not Is_OK_Static_Expression (E) then
6180 Flag_Non_Static_Expr
6181 ("non-static expression used for delta value!", E);
6183 elsif not UR_Is_Positive (Expr_Value_R (E)) then
6184 Error_Msg_N ("delta expression must be positive", E);
6190 -- If any of above errors occurred, then replace the incorrect
6191 -- expression by the real 0.1, which should prevent further errors.
6194 Make_Real_Literal (Sloc (E), Ureal_Tenth));
6195 Analyze_And_Resolve (E, Standard_Float);
6197 end Check_Delta_Expression;
6199 -----------------------------
6200 -- Check_Digits_Expression --
6201 -----------------------------
6203 procedure Check_Digits_Expression (E : Node_Id) is
6205 if not (Is_Integer_Type (Etype (E))) then
6206 Wrong_Type (E, Any_Integer);
6208 elsif not Is_OK_Static_Expression (E) then
6209 Flag_Non_Static_Expr
6210 ("non-static expression used for digits value!", E);
6212 elsif Expr_Value (E) <= 0 then
6213 Error_Msg_N ("digits value must be greater than zero", E);
6219 -- If any of above errors occurred, then replace the incorrect
6220 -- expression by the integer 1, which should prevent further errors.
6222 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
6223 Analyze_And_Resolve (E, Standard_Integer);
6225 end Check_Digits_Expression;
6227 --------------------------
6228 -- Check_Initialization --
6229 --------------------------
6231 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
6233 if (Is_Limited_Type (T)
6234 or else Is_Limited_Composite (T))
6235 and then not In_Instance
6237 -- Relax the strictness of the front-end in case of limited
6238 -- aggregates and extension aggregates.
6240 if Extensions_Allowed
6241 and then (Nkind (Exp) = N_Aggregate
6242 or else Nkind (Exp) = N_Extension_Aggregate)
6247 ("cannot initialize entities of limited type", Exp);
6248 Explain_Limited_Type (T, Exp);
6251 end Check_Initialization;
6253 ------------------------------------
6254 -- Check_Or_Process_Discriminants --
6255 ------------------------------------
6257 -- If an incomplete or private type declaration was already given for
6258 -- the type, the discriminants may have already been processed if they
6259 -- were present on the incomplete declaration. In this case a full
6260 -- conformance check is performed otherwise just process them.
6262 procedure Check_Or_Process_Discriminants
6265 Prev : Entity_Id := Empty)
6268 if Has_Discriminants (T) then
6270 -- Make the discriminants visible to component declarations.
6273 D : Entity_Id := First_Discriminant (T);
6277 while Present (D) loop
6278 Prev := Current_Entity (D);
6279 Set_Current_Entity (D);
6280 Set_Is_Immediately_Visible (D);
6281 Set_Homonym (D, Prev);
6283 -- This restriction gets applied to the full type here; it
6284 -- has already been applied earlier to the partial view
6286 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6288 Next_Discriminant (D);
6292 elsif Present (Discriminant_Specifications (N)) then
6293 Process_Discriminants (N, Prev);
6295 end Check_Or_Process_Discriminants;
6297 ----------------------
6298 -- Check_Real_Bound --
6299 ----------------------
6301 procedure Check_Real_Bound (Bound : Node_Id) is
6303 if not Is_Real_Type (Etype (Bound)) then
6305 ("bound in real type definition must be of real type", Bound);
6307 elsif not Is_OK_Static_Expression (Bound) then
6308 Flag_Non_Static_Expr
6309 ("non-static expression used for real type bound!", Bound);
6316 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6318 Resolve (Bound, Standard_Float);
6319 end Check_Real_Bound;
6321 ------------------------------
6322 -- Complete_Private_Subtype --
6323 ------------------------------
6325 procedure Complete_Private_Subtype
6328 Full_Base : Entity_Id;
6329 Related_Nod : Node_Id)
6331 Save_Next_Entity : Entity_Id;
6332 Save_Homonym : Entity_Id;
6335 -- Set semantic attributes for (implicit) private subtype completion.
6336 -- If the full type has no discriminants, then it is a copy of the full
6337 -- view of the base. Otherwise, it is a subtype of the base with a
6338 -- possible discriminant constraint. Save and restore the original
6339 -- Next_Entity field of full to ensure that the calls to Copy_Node
6340 -- do not corrupt the entity chain.
6342 -- Note that the type of the full view is the same entity as the
6343 -- type of the partial view. In this fashion, the subtype has
6344 -- access to the correct view of the parent.
6346 Save_Next_Entity := Next_Entity (Full);
6347 Save_Homonym := Homonym (Priv);
6349 case Ekind (Full_Base) is
6351 when E_Record_Type |
6357 Copy_Node (Priv, Full);
6359 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6360 Set_First_Entity (Full, First_Entity (Full_Base));
6361 Set_Last_Entity (Full, Last_Entity (Full_Base));
6364 Copy_Node (Full_Base, Full);
6365 Set_Chars (Full, Chars (Priv));
6366 Conditional_Delay (Full, Priv);
6367 Set_Sloc (Full, Sloc (Priv));
6371 Set_Next_Entity (Full, Save_Next_Entity);
6372 Set_Homonym (Full, Save_Homonym);
6373 Set_Associated_Node_For_Itype (Full, Related_Nod);
6375 -- Set common attributes for all subtypes.
6377 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6379 -- The Etype of the full view is inconsistent. Gigi needs to see the
6380 -- structural full view, which is what the current scheme gives:
6381 -- the Etype of the full view is the etype of the full base. However,
6382 -- if the full base is a derived type, the full view then looks like
6383 -- a subtype of the parent, not a subtype of the full base. If instead
6386 -- Set_Etype (Full, Full_Base);
6388 -- then we get inconsistencies in the front-end (confusion between
6389 -- views). Several outstanding bugs are related to this.
6391 Set_Is_First_Subtype (Full, False);
6392 Set_Scope (Full, Scope (Priv));
6393 Set_Size_Info (Full, Full_Base);
6394 Set_RM_Size (Full, RM_Size (Full_Base));
6395 Set_Is_Itype (Full);
6397 -- A subtype of a private-type-without-discriminants, whose full-view
6398 -- has discriminants with default expressions, is not constrained!
6400 if not Has_Discriminants (Priv) then
6401 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6403 if Has_Discriminants (Full_Base) then
6404 Set_Discriminant_Constraint
6405 (Full, Discriminant_Constraint (Full_Base));
6409 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6410 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6412 -- Freeze the private subtype entity if its parent is delayed,
6413 -- and not already frozen. We skip this processing if the type
6414 -- is an anonymous subtype of a record component, or is the
6415 -- corresponding record of a protected type, since ???
6417 if not Is_Type (Scope (Full)) then
6418 Set_Has_Delayed_Freeze (Full,
6419 Has_Delayed_Freeze (Full_Base)
6420 and then (not Is_Frozen (Full_Base)));
6423 Set_Freeze_Node (Full, Empty);
6424 Set_Is_Frozen (Full, False);
6425 Set_Full_View (Priv, Full);
6427 if Has_Discriminants (Full) then
6428 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
6429 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
6430 if Has_Unknown_Discriminants (Full) then
6431 Set_Discriminant_Constraint (Full, No_Elist);
6435 if Ekind (Full_Base) = E_Record_Type
6436 and then Has_Discriminants (Full_Base)
6437 and then Has_Discriminants (Priv) -- might not, if errors
6438 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
6440 Create_Constrained_Components
6441 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
6443 -- If the full base is itself derived from private, build a congruent
6444 -- subtype of its underlying type, for use by the back end.
6446 elsif Ekind (Full_Base) in Private_Kind
6447 and then Is_Derived_Type (Full_Base)
6448 and then Has_Discriminants (Full_Base)
6450 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
6452 Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
6454 elsif Is_Record_Type (Full_Base) then
6456 -- Show Full is simply a renaming of Full_Base.
6458 Set_Cloned_Subtype (Full, Full_Base);
6461 -- It is unsafe to share to bounds of a scalar type, because the
6462 -- Itype is elaborated on demand, and if a bound is non-static
6463 -- then different orders of elaboration in different units will
6464 -- lead to different external symbols.
6466 if Is_Scalar_Type (Full_Base) then
6467 Set_Scalar_Range (Full,
6468 Make_Range (Sloc (Related_Nod),
6470 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
6472 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
6474 -- This completion inherits the bounds of the full parent, but if
6475 -- the parent is an unconstrained floating point type, so is the
6478 if Is_Floating_Point_Type (Full_Base) then
6479 Set_Includes_Infinities
6480 (Scalar_Range (Full), Has_Infinities (Full_Base));
6484 -- ??? It seems that a lot of fields are missing that should be
6485 -- copied from Full_Base to Full. Here are some that are introduced
6486 -- in a non-disruptive way but a cleanup is necessary.
6488 if Is_Tagged_Type (Full_Base) then
6489 Set_Is_Tagged_Type (Full);
6490 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
6491 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
6493 elsif Is_Concurrent_Type (Full_Base) then
6494 if Has_Discriminants (Full)
6495 and then Present (Corresponding_Record_Type (Full_Base))
6497 Set_Corresponding_Record_Type (Full,
6498 Constrain_Corresponding_Record
6499 (Full, Corresponding_Record_Type (Full_Base),
6500 Related_Nod, Full_Base));
6503 Set_Corresponding_Record_Type (Full,
6504 Corresponding_Record_Type (Full_Base));
6508 end Complete_Private_Subtype;
6510 ----------------------------
6511 -- Constant_Redeclaration --
6512 ----------------------------
6514 procedure Constant_Redeclaration
6519 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
6520 Obj_Def : constant Node_Id := Object_Definition (N);
6523 procedure Check_Recursive_Declaration (Typ : Entity_Id);
6524 -- If deferred constant is an access type initialized with an
6525 -- allocator, check whether there is an illegal recursion in the
6526 -- definition, through a default value of some record subcomponent.
6527 -- This is normally detected when generating init procs, but requires
6528 -- this additional mechanism when expansion is disabled.
6530 ---------------------------------
6531 -- Check_Recursive_Declaration --
6532 ---------------------------------
6534 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
6538 if Is_Record_Type (Typ) then
6539 Comp := First_Component (Typ);
6541 while Present (Comp) loop
6542 if Comes_From_Source (Comp) then
6543 if Present (Expression (Parent (Comp)))
6544 and then Is_Entity_Name (Expression (Parent (Comp)))
6545 and then Entity (Expression (Parent (Comp))) = Prev
6547 Error_Msg_Sloc := Sloc (Parent (Comp));
6549 ("illegal circularity with declaration for&#",
6553 elsif Is_Record_Type (Etype (Comp)) then
6554 Check_Recursive_Declaration (Etype (Comp));
6558 Next_Component (Comp);
6561 end Check_Recursive_Declaration;
6563 -- Start of processing for Constant_Redeclaration
6566 if Nkind (Parent (Prev)) = N_Object_Declaration then
6567 if Nkind (Object_Definition
6568 (Parent (Prev))) = N_Subtype_Indication
6570 -- Find type of new declaration. The constraints of the two
6571 -- views must match statically, but there is no point in
6572 -- creating an itype for the full view.
6574 if Nkind (Obj_Def) = N_Subtype_Indication then
6575 Find_Type (Subtype_Mark (Obj_Def));
6576 New_T := Entity (Subtype_Mark (Obj_Def));
6579 Find_Type (Obj_Def);
6580 New_T := Entity (Obj_Def);
6586 -- The full view may impose a constraint, even if the partial
6587 -- view does not, so construct the subtype.
6589 New_T := Find_Type_Of_Object (Obj_Def, N);
6594 -- Current declaration is illegal, diagnosed below in Enter_Name.
6600 -- If previous full declaration exists, or if a homograph is present,
6601 -- let Enter_Name handle it, either with an error, or with the removal
6602 -- of an overridden implicit subprogram.
6604 if Ekind (Prev) /= E_Constant
6605 or else Present (Expression (Parent (Prev)))
6606 or else Present (Full_View (Prev))
6610 -- Verify that types of both declarations match.
6612 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
6613 Error_Msg_Sloc := Sloc (Prev);
6614 Error_Msg_N ("type does not match declaration#", N);
6615 Set_Full_View (Prev, Id);
6616 Set_Etype (Id, Any_Type);
6618 -- If so, process the full constant declaration
6621 Set_Full_View (Prev, Id);
6622 Set_Is_Public (Id, Is_Public (Prev));
6623 Set_Is_Internal (Id);
6624 Append_Entity (Id, Current_Scope);
6626 -- Check ALIASED present if present before (RM 7.4(7))
6628 if Is_Aliased (Prev)
6629 and then not Aliased_Present (N)
6631 Error_Msg_Sloc := Sloc (Prev);
6632 Error_Msg_N ("ALIASED required (see declaration#)", N);
6635 -- Check that placement is in private part and that the incomplete
6636 -- declaration appeared in the visible part.
6638 if Ekind (Current_Scope) = E_Package
6639 and then not In_Private_Part (Current_Scope)
6641 Error_Msg_Sloc := Sloc (Prev);
6642 Error_Msg_N ("full constant for declaration#"
6643 & " must be in private part", N);
6645 elsif Ekind (Current_Scope) = E_Package
6646 and then List_Containing (Parent (Prev))
6647 /= Visible_Declarations
6648 (Specification (Unit_Declaration_Node (Current_Scope)))
6651 ("deferred constant must be declared in visible part",
6655 if Is_Access_Type (T)
6656 and then Nkind (Expression (N)) = N_Allocator
6658 Check_Recursive_Declaration (Designated_Type (T));
6661 end Constant_Redeclaration;
6663 ----------------------
6664 -- Constrain_Access --
6665 ----------------------
6667 procedure Constrain_Access
6668 (Def_Id : in out Entity_Id;
6670 Related_Nod : Node_Id)
6672 T : constant Entity_Id := Entity (Subtype_Mark (S));
6673 Desig_Type : constant Entity_Id := Designated_Type (T);
6674 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
6675 Constraint_OK : Boolean := True;
6678 if Is_Array_Type (Desig_Type) then
6679 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
6681 elsif (Is_Record_Type (Desig_Type)
6682 or else Is_Incomplete_Or_Private_Type (Desig_Type))
6683 and then not Is_Constrained (Desig_Type)
6685 -- ??? The following code is a temporary kludge to ignore
6686 -- discriminant constraint on access type if
6687 -- it is constraining the current record. Avoid creating the
6688 -- implicit subtype of the record we are currently compiling
6689 -- since right now, we cannot handle these.
6690 -- For now, just return the access type itself.
6692 if Desig_Type = Current_Scope
6693 and then No (Def_Id)
6695 Set_Ekind (Desig_Subtype, E_Record_Subtype);
6696 Def_Id := Entity (Subtype_Mark (S));
6698 -- This call added to ensure that the constraint is
6699 -- analyzed (needed for a B test). Note that we
6700 -- still return early from this procedure to avoid
6701 -- recursive processing. ???
6703 Constrain_Discriminated_Type
6704 (Desig_Subtype, S, Related_Nod, For_Access => True);
6709 if Ekind (T) = E_General_Access_Type
6710 and then Has_Private_Declaration (Desig_Type)
6711 and then In_Open_Scopes (Scope (Desig_Type))
6713 -- Enforce rule that the constraint is illegal if there is
6714 -- an unconstrained view of the designated type. This means
6715 -- that the partial view (either a private type declaration or
6716 -- a derivation from a private type) has no discriminants.
6717 -- (Defect Report 8652/0008, Technical Corrigendum 1, checked
6718 -- by ACATS B371001).
6721 Pack : constant Node_Id :=
6722 Unit_Declaration_Node (Scope (Desig_Type));
6727 if Nkind (Pack) = N_Package_Declaration then
6728 Decls := Visible_Declarations (Specification (Pack));
6729 Decl := First (Decls);
6731 while Present (Decl) loop
6732 if (Nkind (Decl) = N_Private_Type_Declaration
6734 Chars (Defining_Identifier (Decl)) =
6738 (Nkind (Decl) = N_Full_Type_Declaration
6740 Chars (Defining_Identifier (Decl)) =
6742 and then Is_Derived_Type (Desig_Type)
6744 Has_Private_Declaration (Etype (Desig_Type)))
6746 if No (Discriminant_Specifications (Decl)) then
6748 ("cannot constrain general access type " &
6749 "if designated type has unconstrained view", S);
6761 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
6762 For_Access => True);
6764 elsif (Is_Task_Type (Desig_Type)
6765 or else Is_Protected_Type (Desig_Type))
6766 and then not Is_Constrained (Desig_Type)
6768 Constrain_Concurrent
6769 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
6772 Error_Msg_N ("invalid constraint on access type", S);
6773 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
6774 Constraint_OK := False;
6778 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
6780 Set_Ekind (Def_Id, E_Access_Subtype);
6783 if Constraint_OK then
6784 Set_Etype (Def_Id, Base_Type (T));
6786 if Is_Private_Type (Desig_Type) then
6787 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
6790 Set_Etype (Def_Id, Any_Type);
6793 Set_Size_Info (Def_Id, T);
6794 Set_Is_Constrained (Def_Id, Constraint_OK);
6795 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
6796 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6797 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
6799 -- Itypes created for constrained record components do not receive
6800 -- a freeze node, they are elaborated when first seen.
6802 if not Is_Record_Type (Current_Scope) then
6803 Conditional_Delay (Def_Id, T);
6805 end Constrain_Access;
6807 ---------------------
6808 -- Constrain_Array --
6809 ---------------------
6811 procedure Constrain_Array
6812 (Def_Id : in out Entity_Id;
6814 Related_Nod : Node_Id;
6815 Related_Id : Entity_Id;
6818 C : constant Node_Id := Constraint (SI);
6819 Number_Of_Constraints : Nat := 0;
6822 Constraint_OK : Boolean := True;
6825 T := Entity (Subtype_Mark (SI));
6827 if Ekind (T) in Access_Kind then
6828 T := Designated_Type (T);
6831 -- If an index constraint follows a subtype mark in a subtype indication
6832 -- then the type or subtype denoted by the subtype mark must not already
6833 -- impose an index constraint. The subtype mark must denote either an
6834 -- unconstrained array type or an access type whose designated type
6835 -- is such an array type... (RM 3.6.1)
6837 if Is_Constrained (T) then
6839 ("array type is already constrained", Subtype_Mark (SI));
6840 Constraint_OK := False;
6843 S := First (Constraints (C));
6845 while Present (S) loop
6846 Number_Of_Constraints := Number_Of_Constraints + 1;
6850 -- In either case, the index constraint must provide a discrete
6851 -- range for each index of the array type and the type of each
6852 -- discrete range must be the same as that of the corresponding
6853 -- index. (RM 3.6.1)
6855 if Number_Of_Constraints /= Number_Dimensions (T) then
6856 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
6857 Constraint_OK := False;
6860 S := First (Constraints (C));
6861 Index := First_Index (T);
6864 -- Apply constraints to each index type
6866 for J in 1 .. Number_Of_Constraints loop
6867 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
6877 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
6878 Set_Parent (Def_Id, Related_Nod);
6881 Set_Ekind (Def_Id, E_Array_Subtype);
6884 Set_Size_Info (Def_Id, (T));
6885 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6886 Set_Etype (Def_Id, Base_Type (T));
6888 if Constraint_OK then
6889 Set_First_Index (Def_Id, First (Constraints (C)));
6892 Set_Is_Constrained (Def_Id, True);
6893 Set_Is_Aliased (Def_Id, Is_Aliased (T));
6894 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6896 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
6897 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
6899 -- If the subtype is not that of a record component, build a freeze
6900 -- node if parent still needs one.
6902 -- If the subtype is not that of a record component, make sure
6903 -- that the Depends_On_Private status is set (explanation ???)
6904 -- and also that a conditional delay is set.
6906 if not Is_Type (Scope (Def_Id)) then
6907 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6908 Conditional_Delay (Def_Id, T);
6911 end Constrain_Array;
6913 ------------------------------
6914 -- Constrain_Component_Type --
6915 ------------------------------
6917 function Constrain_Component_Type
6918 (Compon_Type : Entity_Id;
6919 Constrained_Typ : Entity_Id;
6920 Related_Node : Node_Id;
6922 Constraints : Elist_Id) return Entity_Id
6924 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
6926 function Build_Constrained_Array_Type
6927 (Old_Type : Entity_Id) return Entity_Id;
6928 -- If Old_Type is an array type, one of whose indices is
6929 -- constrained by a discriminant, build an Itype whose constraint
6930 -- replaces the discriminant with its value in the constraint.
6932 function Build_Constrained_Discriminated_Type
6933 (Old_Type : Entity_Id) return Entity_Id;
6934 -- Ditto for record components.
6936 function Build_Constrained_Access_Type
6937 (Old_Type : Entity_Id) return Entity_Id;
6938 -- Ditto for access types. Makes use of previous two functions, to
6939 -- constrain designated type.
6941 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
6942 -- T is an array or discriminated type, C is a list of constraints
6943 -- that apply to T. This routine builds the constrained subtype.
6945 function Is_Discriminant (Expr : Node_Id) return Boolean;
6946 -- Returns True if Expr is a discriminant.
6948 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
6949 -- Find the value of discriminant Discrim in Constraint.
6951 -----------------------------------
6952 -- Build_Constrained_Access_Type --
6953 -----------------------------------
6955 function Build_Constrained_Access_Type
6956 (Old_Type : Entity_Id) return Entity_Id
6958 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
6960 Desig_Subtype : Entity_Id;
6964 -- if the original access type was not embedded in the enclosing
6965 -- type definition, there is no need to produce a new access
6966 -- subtype. In fact every access type with an explicit constraint
6967 -- generates an itype whose scope is the enclosing record.
6969 if not Is_Type (Scope (Old_Type)) then
6972 elsif Is_Array_Type (Desig_Type) then
6973 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
6975 elsif Has_Discriminants (Desig_Type) then
6977 -- This may be an access type to an enclosing record type for
6978 -- which we are constructing the constrained components. Return
6979 -- the enclosing record subtype. This is not always correct,
6980 -- but avoids infinite recursion. ???
6982 Desig_Subtype := Any_Type;
6984 for J in reverse 0 .. Scope_Stack.Last loop
6985 Scop := Scope_Stack.Table (J).Entity;
6988 and then Base_Type (Scop) = Base_Type (Desig_Type)
6990 Desig_Subtype := Scop;
6993 exit when not Is_Type (Scop);
6996 if Desig_Subtype = Any_Type then
6998 Build_Constrained_Discriminated_Type (Desig_Type);
7005 if Desig_Subtype /= Desig_Type then
7006 -- The Related_Node better be here or else we won't be able
7007 -- to attach new itypes to a node in the tree.
7009 pragma Assert (Present (Related_Node));
7011 Itype := Create_Itype (E_Access_Subtype, Related_Node);
7013 Set_Etype (Itype, Base_Type (Old_Type));
7014 Set_Size_Info (Itype, (Old_Type));
7015 Set_Directly_Designated_Type (Itype, Desig_Subtype);
7016 Set_Depends_On_Private (Itype, Has_Private_Component
7018 Set_Is_Access_Constant (Itype, Is_Access_Constant
7021 -- The new itype needs freezing when it depends on a not frozen
7022 -- type and the enclosing subtype needs freezing.
7024 if Has_Delayed_Freeze (Constrained_Typ)
7025 and then not Is_Frozen (Constrained_Typ)
7027 Conditional_Delay (Itype, Base_Type (Old_Type));
7035 end Build_Constrained_Access_Type;
7037 ----------------------------------
7038 -- Build_Constrained_Array_Type --
7039 ----------------------------------
7041 function Build_Constrained_Array_Type
7042 (Old_Type : Entity_Id) return Entity_Id
7046 Old_Index : Node_Id;
7047 Range_Node : Node_Id;
7048 Constr_List : List_Id;
7050 Need_To_Create_Itype : Boolean := False;
7053 Old_Index := First_Index (Old_Type);
7054 while Present (Old_Index) loop
7055 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
7057 if Is_Discriminant (Lo_Expr)
7058 or else Is_Discriminant (Hi_Expr)
7060 Need_To_Create_Itype := True;
7063 Next_Index (Old_Index);
7066 if Need_To_Create_Itype then
7067 Constr_List := New_List;
7069 Old_Index := First_Index (Old_Type);
7070 while Present (Old_Index) loop
7071 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
7073 if Is_Discriminant (Lo_Expr) then
7074 Lo_Expr := Get_Discr_Value (Lo_Expr);
7077 if Is_Discriminant (Hi_Expr) then
7078 Hi_Expr := Get_Discr_Value (Hi_Expr);
7083 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
7085 Append (Range_Node, To => Constr_List);
7087 Next_Index (Old_Index);
7090 return Build_Subtype (Old_Type, Constr_List);
7095 end Build_Constrained_Array_Type;
7097 ------------------------------------------
7098 -- Build_Constrained_Discriminated_Type --
7099 ------------------------------------------
7101 function Build_Constrained_Discriminated_Type
7102 (Old_Type : Entity_Id) return Entity_Id
7105 Constr_List : List_Id;
7106 Old_Constraint : Elmt_Id;
7108 Need_To_Create_Itype : Boolean := False;
7111 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
7112 while Present (Old_Constraint) loop
7113 Expr := Node (Old_Constraint);
7115 if Is_Discriminant (Expr) then
7116 Need_To_Create_Itype := True;
7119 Next_Elmt (Old_Constraint);
7122 if Need_To_Create_Itype then
7123 Constr_List := New_List;
7125 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
7126 while Present (Old_Constraint) loop
7127 Expr := Node (Old_Constraint);
7129 if Is_Discriminant (Expr) then
7130 Expr := Get_Discr_Value (Expr);
7133 Append (New_Copy_Tree (Expr), To => Constr_List);
7135 Next_Elmt (Old_Constraint);
7138 return Build_Subtype (Old_Type, Constr_List);
7143 end Build_Constrained_Discriminated_Type;
7149 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
7151 Subtyp_Decl : Node_Id;
7153 Btyp : Entity_Id := Base_Type (T);
7156 -- The Related_Node better be here or else we won't be able
7157 -- to attach new itypes to a node in the tree.
7159 pragma Assert (Present (Related_Node));
7161 -- If the view of the component's type is incomplete or private
7162 -- with unknown discriminants, then the constraint must be applied
7163 -- to the full type.
7165 if Has_Unknown_Discriminants (Btyp)
7166 and then Present (Underlying_Type (Btyp))
7168 Btyp := Underlying_Type (Btyp);
7172 Make_Subtype_Indication (Loc,
7173 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7174 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
7176 Def_Id := Create_Itype (Ekind (T), Related_Node);
7179 Make_Subtype_Declaration (Loc,
7180 Defining_Identifier => Def_Id,
7181 Subtype_Indication => Indic);
7182 Set_Parent (Subtyp_Decl, Parent (Related_Node));
7184 -- Itypes must be analyzed with checks off (see itypes.ads).
7186 Analyze (Subtyp_Decl, Suppress => All_Checks);
7191 ---------------------
7192 -- Get_Discr_Value --
7193 ---------------------
7195 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
7196 D : Entity_Id := First_Discriminant (Typ);
7197 E : Elmt_Id := First_Elmt (Constraints);
7201 -- The discriminant may be declared for the type, in which case we
7202 -- find it by iterating over the list of discriminants. If the
7203 -- discriminant is inherited from a parent type, it appears as the
7204 -- corresponding discriminant of the current type. This will be the
7205 -- case when constraining an inherited component whose constraint is
7206 -- given by a discriminant of the parent.
7208 while Present (D) loop
7209 if D = Entity (Discrim)
7210 or else Corresponding_Discriminant (D) = Entity (Discrim)
7215 Next_Discriminant (D);
7219 -- The corresponding_Discriminant mechanism is incomplete, because
7220 -- the correspondence between new and old discriminants is not one
7221 -- to one: one new discriminant can constrain several old ones.
7222 -- In that case, scan sequentially the stored_constraint, the list
7223 -- of discriminants of the parents, and the constraints.
7225 if Is_Derived_Type (Typ)
7226 and then Present (Stored_Constraint (Typ))
7227 and then Scope (Entity (Discrim)) = Etype (Typ)
7229 D := First_Discriminant (Etype (Typ));
7230 E := First_Elmt (Constraints);
7231 G := First_Elmt (Stored_Constraint (Typ));
7233 while Present (D) loop
7234 if D = Entity (Discrim) then
7238 Next_Discriminant (D);
7244 -- Something is wrong if we did not find the value
7246 raise Program_Error;
7247 end Get_Discr_Value;
7249 ---------------------
7250 -- Is_Discriminant --
7251 ---------------------
7253 function Is_Discriminant (Expr : Node_Id) return Boolean is
7254 Discrim_Scope : Entity_Id;
7257 if Denotes_Discriminant (Expr) then
7258 Discrim_Scope := Scope (Entity (Expr));
7260 -- Either we have a reference to one of Typ's discriminants,
7262 pragma Assert (Discrim_Scope = Typ
7264 -- or to the discriminants of the parent type, in the case
7265 -- of a derivation of a tagged type with variants.
7267 or else Discrim_Scope = Etype (Typ)
7268 or else Full_View (Discrim_Scope) = Etype (Typ)
7270 -- or same as above for the case where the discriminants
7271 -- were declared in Typ's private view.
7273 or else (Is_Private_Type (Discrim_Scope)
7274 and then Chars (Discrim_Scope) = Chars (Typ))
7276 -- or else we are deriving from the full view and the
7277 -- discriminant is declared in the private entity.
7279 or else (Is_Private_Type (Typ)
7280 and then Chars (Discrim_Scope) = Chars (Typ))
7282 -- or we have a class-wide type, in which case make sure the
7283 -- discriminant found belongs to the root type.
7285 or else (Is_Class_Wide_Type (Typ)
7286 and then Etype (Typ) = Discrim_Scope));
7291 -- In all other cases we have something wrong.
7294 end Is_Discriminant;
7296 -- Start of processing for Constrain_Component_Type
7299 if Is_Array_Type (Compon_Type) then
7300 return Build_Constrained_Array_Type (Compon_Type);
7302 elsif Has_Discriminants (Compon_Type) then
7303 return Build_Constrained_Discriminated_Type (Compon_Type);
7305 elsif Is_Access_Type (Compon_Type) then
7306 return Build_Constrained_Access_Type (Compon_Type);
7310 end Constrain_Component_Type;
7312 --------------------------
7313 -- Constrain_Concurrent --
7314 --------------------------
7316 -- For concurrent types, the associated record value type carries the same
7317 -- discriminants, so when we constrain a concurrent type, we must constrain
7318 -- the value type as well.
7320 procedure Constrain_Concurrent
7321 (Def_Id : in out Entity_Id;
7323 Related_Nod : Node_Id;
7324 Related_Id : Entity_Id;
7327 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
7331 if Ekind (T_Ent) in Access_Kind then
7332 T_Ent := Designated_Type (T_Ent);
7335 T_Val := Corresponding_Record_Type (T_Ent);
7337 if Present (T_Val) then
7340 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7343 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7345 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7346 Set_Corresponding_Record_Type (Def_Id,
7347 Constrain_Corresponding_Record
7348 (Def_Id, T_Val, Related_Nod, Related_Id));
7351 -- If there is no associated record, expansion is disabled and this
7352 -- is a generic context. Create a subtype in any case, so that
7353 -- semantic analysis can proceed.
7356 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7359 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7361 end Constrain_Concurrent;
7363 ------------------------------------
7364 -- Constrain_Corresponding_Record --
7365 ------------------------------------
7367 function Constrain_Corresponding_Record
7368 (Prot_Subt : Entity_Id;
7369 Corr_Rec : Entity_Id;
7370 Related_Nod : Node_Id;
7371 Related_Id : Entity_Id) return Entity_Id
7373 T_Sub : constant Entity_Id
7374 := Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
7377 Set_Etype (T_Sub, Corr_Rec);
7378 Init_Size_Align (T_Sub);
7379 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
7380 Set_Is_Constrained (T_Sub, True);
7381 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
7382 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
7384 Conditional_Delay (T_Sub, Corr_Rec);
7386 if Has_Discriminants (Prot_Subt) then -- False only if errors.
7387 Set_Discriminant_Constraint (T_Sub,
7388 Discriminant_Constraint (Prot_Subt));
7389 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
7390 Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
7391 Discriminant_Constraint (T_Sub));
7394 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
7397 end Constrain_Corresponding_Record;
7399 -----------------------
7400 -- Constrain_Decimal --
7401 -----------------------
7403 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
7404 T : constant Entity_Id := Entity (Subtype_Mark (S));
7405 C : constant Node_Id := Constraint (S);
7406 Loc : constant Source_Ptr := Sloc (C);
7407 Range_Expr : Node_Id;
7408 Digits_Expr : Node_Id;
7413 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7415 if Nkind (C) = N_Range_Constraint then
7416 Range_Expr := Range_Expression (C);
7417 Digits_Val := Digits_Value (T);
7420 pragma Assert (Nkind (C) = N_Digits_Constraint);
7421 Digits_Expr := Digits_Expression (C);
7422 Analyze_And_Resolve (Digits_Expr, Any_Integer);
7424 Check_Digits_Expression (Digits_Expr);
7425 Digits_Val := Expr_Value (Digits_Expr);
7427 if Digits_Val > Digits_Value (T) then
7429 ("digits expression is incompatible with subtype", C);
7430 Digits_Val := Digits_Value (T);
7433 if Present (Range_Constraint (C)) then
7434 Range_Expr := Range_Expression (Range_Constraint (C));
7436 Range_Expr := Empty;
7440 Set_Etype (Def_Id, Base_Type (T));
7441 Set_Size_Info (Def_Id, (T));
7442 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7443 Set_Delta_Value (Def_Id, Delta_Value (T));
7444 Set_Scale_Value (Def_Id, Scale_Value (T));
7445 Set_Small_Value (Def_Id, Small_Value (T));
7446 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
7447 Set_Digits_Value (Def_Id, Digits_Val);
7449 -- Manufacture range from given digits value if no range present
7451 if No (Range_Expr) then
7452 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
7456 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
7458 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
7462 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
7463 Set_Discrete_RM_Size (Def_Id);
7465 -- Unconditionally delay the freeze, since we cannot set size
7466 -- information in all cases correctly until the freeze point.
7468 Set_Has_Delayed_Freeze (Def_Id);
7469 end Constrain_Decimal;
7471 ----------------------------------
7472 -- Constrain_Discriminated_Type --
7473 ----------------------------------
7475 procedure Constrain_Discriminated_Type
7476 (Def_Id : Entity_Id;
7478 Related_Nod : Node_Id;
7479 For_Access : Boolean := False)
7481 E : constant Entity_Id := Entity (Subtype_Mark (S));
7484 Elist : Elist_Id := New_Elmt_List;
7486 procedure Fixup_Bad_Constraint;
7487 -- This is called after finding a bad constraint, and after having
7488 -- posted an appropriate error message. The mission is to leave the
7489 -- entity T in as reasonable state as possible!
7491 --------------------------
7492 -- Fixup_Bad_Constraint --
7493 --------------------------
7495 procedure Fixup_Bad_Constraint is
7497 -- Set a reasonable Ekind for the entity. For an incomplete type,
7498 -- we can't do much, but for other types, we can set the proper
7499 -- corresponding subtype kind.
7501 if Ekind (T) = E_Incomplete_Type then
7502 Set_Ekind (Def_Id, Ekind (T));
7504 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
7507 Set_Etype (Def_Id, Any_Type);
7508 Set_Error_Posted (Def_Id);
7509 end Fixup_Bad_Constraint;
7511 -- Start of processing for Constrain_Discriminated_Type
7514 C := Constraint (S);
7516 -- A discriminant constraint is only allowed in a subtype indication,
7517 -- after a subtype mark. This subtype mark must denote either a type
7518 -- with discriminants, or an access type whose designated type is a
7519 -- type with discriminants. A discriminant constraint specifies the
7520 -- values of these discriminants (RM 3.7.2(5)).
7522 T := Base_Type (Entity (Subtype_Mark (S)));
7524 if Ekind (T) in Access_Kind then
7525 T := Designated_Type (T);
7528 if not Has_Discriminants (T) then
7529 Error_Msg_N ("invalid constraint: type has no discriminant", C);
7530 Fixup_Bad_Constraint;
7533 elsif Is_Constrained (E)
7534 or else (Ekind (E) = E_Class_Wide_Subtype
7535 and then Present (Discriminant_Constraint (E)))
7537 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
7538 Fixup_Bad_Constraint;
7542 -- T may be an unconstrained subtype (e.g. a generic actual).
7543 -- Constraint applies to the base type.
7547 Elist := Build_Discriminant_Constraints (T, S);
7549 -- If the list returned was empty we had an error in building the
7550 -- discriminant constraint. We have also already signalled an error
7551 -- in the incomplete type case
7553 if Is_Empty_Elmt_List (Elist) then
7554 Fixup_Bad_Constraint;
7558 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
7559 end Constrain_Discriminated_Type;
7561 ---------------------------
7562 -- Constrain_Enumeration --
7563 ---------------------------
7565 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
7566 T : constant Entity_Id := Entity (Subtype_Mark (S));
7567 C : constant Node_Id := Constraint (S);
7570 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7572 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
7574 Set_Etype (Def_Id, Base_Type (T));
7575 Set_Size_Info (Def_Id, (T));
7576 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7577 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7579 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
7581 Set_Discrete_RM_Size (Def_Id);
7583 end Constrain_Enumeration;
7585 ----------------------
7586 -- Constrain_Float --
7587 ----------------------
7589 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
7590 T : constant Entity_Id := Entity (Subtype_Mark (S));
7596 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
7598 Set_Etype (Def_Id, Base_Type (T));
7599 Set_Size_Info (Def_Id, (T));
7600 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7602 -- Process the constraint
7604 C := Constraint (S);
7606 -- Digits constraint present
7608 if Nkind (C) = N_Digits_Constraint then
7609 if Warn_On_Obsolescent_Feature then
7611 ("subtype digits constraint is an " &
7612 "obsolescent feature ('R'M 'J.3(8))?", C);
7615 D := Digits_Expression (C);
7616 Analyze_And_Resolve (D, Any_Integer);
7617 Check_Digits_Expression (D);
7618 Set_Digits_Value (Def_Id, Expr_Value (D));
7620 -- Check that digits value is in range. Obviously we can do this
7621 -- at compile time, but it is strictly a runtime check, and of
7622 -- course there is an ACVC test that checks this!
7624 if Digits_Value (Def_Id) > Digits_Value (T) then
7625 Error_Msg_Uint_1 := Digits_Value (T);
7626 Error_Msg_N ("?digits value is too large, maximum is ^", D);
7628 Make_Raise_Constraint_Error (Sloc (D),
7629 Reason => CE_Range_Check_Failed);
7630 Insert_Action (Declaration_Node (Def_Id), Rais);
7633 C := Range_Constraint (C);
7635 -- No digits constraint present
7638 Set_Digits_Value (Def_Id, Digits_Value (T));
7641 -- Range constraint present
7643 if Nkind (C) = N_Range_Constraint then
7644 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
7646 -- No range constraint present
7649 pragma Assert (No (C));
7650 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7653 Set_Is_Constrained (Def_Id);
7654 end Constrain_Float;
7656 ---------------------
7657 -- Constrain_Index --
7658 ---------------------
7660 procedure Constrain_Index
7663 Related_Nod : Node_Id;
7664 Related_Id : Entity_Id;
7669 R : Node_Id := Empty;
7670 Checks_Off : Boolean := False;
7671 T : constant Entity_Id := Etype (Index);
7674 if Nkind (S) = N_Range
7676 (Nkind (S) = N_Attribute_Reference
7677 and then Attribute_Name (S) = Name_Range)
7679 -- A Range attribute will transformed into N_Range by Resolve.
7685 -- ??? Why on earth do we turn checks of in this very specific case ?
7687 -- From the revision history: (Constrain_Index): Call
7688 -- Process_Range_Expr_In_Decl with range checking off for range
7689 -- bounds that are attributes. This avoids some horrible
7690 -- constraint error checks.
7692 if Nkind (R) = N_Range
7693 and then Nkind (Low_Bound (R)) = N_Attribute_Reference
7694 and then Nkind (High_Bound (R)) = N_Attribute_Reference
7699 Process_Range_Expr_In_Decl (R, T, Empty_List, Checks_Off);
7701 if not Error_Posted (S)
7703 (Nkind (S) /= N_Range
7704 or else Base_Type (T) /= Base_Type (Etype (Low_Bound (S)))
7705 or else Base_Type (T) /= Base_Type (Etype (High_Bound (S))))
7707 if Base_Type (T) /= Any_Type
7708 and then Etype (Low_Bound (S)) /= Any_Type
7709 and then Etype (High_Bound (S)) /= Any_Type
7711 Error_Msg_N ("range expected", S);
7715 elsif Nkind (S) = N_Subtype_Indication then
7716 -- the parser has verified that this is a discrete indication.
7718 Resolve_Discrete_Subtype_Indication (S, T);
7719 R := Range_Expression (Constraint (S));
7721 elsif Nkind (S) = N_Discriminant_Association then
7723 -- syntactically valid in subtype indication.
7725 Error_Msg_N ("invalid index constraint", S);
7726 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7729 -- Subtype_Mark case, no anonymous subtypes to construct
7734 if Is_Entity_Name (S) then
7736 if not Is_Type (Entity (S)) then
7737 Error_Msg_N ("expect subtype mark for index constraint", S);
7739 elsif Base_Type (Entity (S)) /= Base_Type (T) then
7740 Wrong_Type (S, Base_Type (T));
7746 Error_Msg_N ("invalid index constraint", S);
7747 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7753 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
7755 Set_Etype (Def_Id, Base_Type (T));
7757 if Is_Modular_Integer_Type (T) then
7758 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7760 elsif Is_Integer_Type (T) then
7761 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7764 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7765 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7768 Set_Size_Info (Def_Id, (T));
7769 Set_RM_Size (Def_Id, RM_Size (T));
7770 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7772 Set_Scalar_Range (Def_Id, R);
7774 Set_Etype (S, Def_Id);
7775 Set_Discrete_RM_Size (Def_Id);
7776 end Constrain_Index;
7778 -----------------------
7779 -- Constrain_Integer --
7780 -----------------------
7782 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
7783 T : constant Entity_Id := Entity (Subtype_Mark (S));
7784 C : constant Node_Id := Constraint (S);
7787 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
7789 if Is_Modular_Integer_Type (T) then
7790 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7792 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7795 Set_Etype (Def_Id, Base_Type (T));
7796 Set_Size_Info (Def_Id, (T));
7797 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7798 Set_Discrete_RM_Size (Def_Id);
7800 end Constrain_Integer;
7802 ------------------------------
7803 -- Constrain_Ordinary_Fixed --
7804 ------------------------------
7806 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
7807 T : constant Entity_Id := Entity (Subtype_Mark (S));
7813 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
7814 Set_Etype (Def_Id, Base_Type (T));
7815 Set_Size_Info (Def_Id, (T));
7816 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7817 Set_Small_Value (Def_Id, Small_Value (T));
7819 -- Process the constraint
7821 C := Constraint (S);
7823 -- Delta constraint present
7825 if Nkind (C) = N_Delta_Constraint then
7826 if Warn_On_Obsolescent_Feature then
7828 ("subtype delta constraint is an " &
7829 "obsolescent feature ('R'M 'J.3(7))?");
7832 D := Delta_Expression (C);
7833 Analyze_And_Resolve (D, Any_Real);
7834 Check_Delta_Expression (D);
7835 Set_Delta_Value (Def_Id, Expr_Value_R (D));
7837 -- Check that delta value is in range. Obviously we can do this
7838 -- at compile time, but it is strictly a runtime check, and of
7839 -- course there is an ACVC test that checks this!
7841 if Delta_Value (Def_Id) < Delta_Value (T) then
7842 Error_Msg_N ("?delta value is too small", D);
7844 Make_Raise_Constraint_Error (Sloc (D),
7845 Reason => CE_Range_Check_Failed);
7846 Insert_Action (Declaration_Node (Def_Id), Rais);
7849 C := Range_Constraint (C);
7851 -- No delta constraint present
7854 Set_Delta_Value (Def_Id, Delta_Value (T));
7857 -- Range constraint present
7859 if Nkind (C) = N_Range_Constraint then
7860 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
7862 -- No range constraint present
7865 pragma Assert (No (C));
7866 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7870 Set_Discrete_RM_Size (Def_Id);
7872 -- Unconditionally delay the freeze, since we cannot set size
7873 -- information in all cases correctly until the freeze point.
7875 Set_Has_Delayed_Freeze (Def_Id);
7876 end Constrain_Ordinary_Fixed;
7878 ---------------------------
7879 -- Convert_Scalar_Bounds --
7880 ---------------------------
7882 procedure Convert_Scalar_Bounds
7884 Parent_Type : Entity_Id;
7885 Derived_Type : Entity_Id;
7888 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
7895 Lo := Build_Scalar_Bound
7896 (Type_Low_Bound (Derived_Type),
7897 Parent_Type, Implicit_Base);
7899 Hi := Build_Scalar_Bound
7900 (Type_High_Bound (Derived_Type),
7901 Parent_Type, Implicit_Base);
7908 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
7910 Set_Parent (Rng, N);
7911 Set_Scalar_Range (Derived_Type, Rng);
7913 -- Analyze the bounds
7915 Analyze_And_Resolve (Lo, Implicit_Base);
7916 Analyze_And_Resolve (Hi, Implicit_Base);
7918 -- Analyze the range itself, except that we do not analyze it if
7919 -- the bounds are real literals, and we have a fixed-point type.
7920 -- The reason for this is that we delay setting the bounds in this
7921 -- case till we know the final Small and Size values (see circuit
7922 -- in Freeze.Freeze_Fixed_Point_Type for further details).
7924 if Is_Fixed_Point_Type (Parent_Type)
7925 and then Nkind (Lo) = N_Real_Literal
7926 and then Nkind (Hi) = N_Real_Literal
7930 -- Here we do the analysis of the range.
7932 -- Note: we do this manually, since if we do a normal Analyze and
7933 -- Resolve call, there are problems with the conversions used for
7934 -- the derived type range.
7937 Set_Etype (Rng, Implicit_Base);
7938 Set_Analyzed (Rng, True);
7940 end Convert_Scalar_Bounds;
7946 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
7949 -- Initialize new full declaration entity by copying the pertinent
7950 -- fields of the corresponding private declaration entity.
7952 -- We temporarily set Ekind to a value appropriate for a type to
7953 -- avoid assert failures in Einfo from checking for setting type
7954 -- attributes on something that is not a type. Ekind (Priv) is an
7955 -- appropriate choice, since it allowed the attributes to be set
7956 -- in the first place. This Ekind value will be modified later.
7958 Set_Ekind (Full, Ekind (Priv));
7960 -- Also set Etype temporarily to Any_Type, again, in the absence
7961 -- of errors, it will be properly reset, and if there are errors,
7962 -- then we want a value of Any_Type to remain.
7964 Set_Etype (Full, Any_Type);
7966 -- Now start copying attributes
7968 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
7970 if Has_Discriminants (Full) then
7971 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
7972 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
7975 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
7976 Set_Homonym (Full, Homonym (Priv));
7977 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
7978 Set_Is_Public (Full, Is_Public (Priv));
7979 Set_Is_Pure (Full, Is_Pure (Priv));
7980 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
7982 Conditional_Delay (Full, Priv);
7984 if Is_Tagged_Type (Full) then
7985 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
7987 if Priv = Base_Type (Priv) then
7988 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
7992 Set_Is_Volatile (Full, Is_Volatile (Priv));
7993 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
7994 Set_Scope (Full, Scope (Priv));
7995 Set_Next_Entity (Full, Next_Entity (Priv));
7996 Set_First_Entity (Full, First_Entity (Priv));
7997 Set_Last_Entity (Full, Last_Entity (Priv));
7999 -- If access types have been recorded for later handling, keep them
8000 -- in the full view so that they get handled when the full view
8001 -- freeze node is expanded.
8003 if Present (Freeze_Node (Priv))
8004 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
8006 Ensure_Freeze_Node (Full);
8007 Set_Access_Types_To_Process
8008 (Freeze_Node (Full),
8009 Access_Types_To_Process (Freeze_Node (Priv)));
8012 -- Swap the two entities. Now Privat is the full type entity and
8013 -- Full is the private one. They will be swapped back at the end
8014 -- of the private part. This swapping ensures that the entity that
8015 -- is visible in the private part is the full declaration.
8017 Exchange_Entities (Priv, Full);
8018 Append_Entity (Full, Scope (Full));
8021 -------------------------------------
8022 -- Copy_Array_Base_Type_Attributes --
8023 -------------------------------------
8025 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
8027 Set_Component_Alignment (T1, Component_Alignment (T2));
8028 Set_Component_Type (T1, Component_Type (T2));
8029 Set_Component_Size (T1, Component_Size (T2));
8030 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
8031 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
8032 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
8033 Set_Has_Task (T1, Has_Task (T2));
8034 Set_Is_Packed (T1, Is_Packed (T2));
8035 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
8036 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
8037 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
8038 end Copy_Array_Base_Type_Attributes;
8040 -----------------------------------
8041 -- Copy_Array_Subtype_Attributes --
8042 -----------------------------------
8044 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
8046 Set_Size_Info (T1, T2);
8048 Set_First_Index (T1, First_Index (T2));
8049 Set_Is_Aliased (T1, Is_Aliased (T2));
8050 Set_Is_Atomic (T1, Is_Atomic (T2));
8051 Set_Is_Volatile (T1, Is_Volatile (T2));
8052 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
8053 Set_Is_Constrained (T1, Is_Constrained (T2));
8054 Set_Depends_On_Private (T1, Has_Private_Component (T2));
8055 Set_First_Rep_Item (T1, First_Rep_Item (T2));
8056 Set_Convention (T1, Convention (T2));
8057 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
8058 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
8059 end Copy_Array_Subtype_Attributes;
8061 -----------------------------------
8062 -- Create_Constrained_Components --
8063 -----------------------------------
8065 procedure Create_Constrained_Components
8067 Decl_Node : Node_Id;
8069 Constraints : Elist_Id)
8071 Loc : constant Source_Ptr := Sloc (Subt);
8072 Comp_List : constant Elist_Id := New_Elmt_List;
8073 Parent_Type : constant Entity_Id := Etype (Typ);
8074 Assoc_List : constant List_Id := New_List;
8075 Discr_Val : Elmt_Id;
8079 Is_Static : Boolean := True;
8081 procedure Collect_Fixed_Components (Typ : Entity_Id);
8082 -- Collect components of parent type that do not appear in a variant
8085 procedure Create_All_Components;
8086 -- Iterate over Comp_List to create the components of the subtype.
8088 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
8089 -- Creates a new component from Old_Compon, copying all the fields from
8090 -- it, including its Etype, inserts the new component in the Subt entity
8091 -- chain and returns the new component.
8093 function Is_Variant_Record (T : Entity_Id) return Boolean;
8094 -- If true, and discriminants are static, collect only components from
8095 -- variants selected by discriminant values.
8097 ------------------------------
8098 -- Collect_Fixed_Components --
8099 ------------------------------
8101 procedure Collect_Fixed_Components (Typ : Entity_Id) is
8103 -- Build association list for discriminants, and find components of
8104 -- the variant part selected by the values of the discriminants.
8106 Old_C := First_Discriminant (Typ);
8107 Discr_Val := First_Elmt (Constraints);
8109 while Present (Old_C) loop
8110 Append_To (Assoc_List,
8111 Make_Component_Association (Loc,
8112 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
8113 Expression => New_Copy (Node (Discr_Val))));
8115 Next_Elmt (Discr_Val);
8116 Next_Discriminant (Old_C);
8119 -- The tag, and the possible parent and controller components
8120 -- are unconditionally in the subtype.
8122 if Is_Tagged_Type (Typ)
8123 or else Has_Controlled_Component (Typ)
8125 Old_C := First_Component (Typ);
8127 while Present (Old_C) loop
8128 if Chars ((Old_C)) = Name_uTag
8129 or else Chars ((Old_C)) = Name_uParent
8130 or else Chars ((Old_C)) = Name_uController
8132 Append_Elmt (Old_C, Comp_List);
8135 Next_Component (Old_C);
8138 end Collect_Fixed_Components;
8140 ---------------------------
8141 -- Create_All_Components --
8142 ---------------------------
8144 procedure Create_All_Components is
8148 Comp := First_Elmt (Comp_List);
8150 while Present (Comp) loop
8151 Old_C := Node (Comp);
8152 New_C := Create_Component (Old_C);
8156 Constrain_Component_Type
8157 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
8158 Set_Is_Public (New_C, Is_Public (Subt));
8162 end Create_All_Components;
8164 ----------------------
8165 -- Create_Component --
8166 ----------------------
8168 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
8169 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
8172 -- Set the parent so we have a proper link for freezing etc. This
8173 -- is not a real parent pointer, since of course our parent does
8174 -- not own up to us and reference us, we are an illegitimate
8175 -- child of the original parent!
8177 Set_Parent (New_Compon, Parent (Old_Compon));
8179 -- We do not want this node marked as Comes_From_Source, since
8180 -- otherwise it would get first class status and a separate
8181 -- cross-reference line would be generated. Illegitimate
8182 -- children do not rate such recognition.
8184 Set_Comes_From_Source (New_Compon, False);
8186 -- But it is a real entity, and a birth certificate must be
8187 -- properly registered by entering it into the entity list.
8189 Enter_Name (New_Compon);
8191 end Create_Component;
8193 -----------------------
8194 -- Is_Variant_Record --
8195 -----------------------
8197 function Is_Variant_Record (T : Entity_Id) return Boolean is
8199 return Nkind (Parent (T)) = N_Full_Type_Declaration
8200 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
8201 and then Present (Component_List (Type_Definition (Parent (T))))
8203 Variant_Part (Component_List (Type_Definition (Parent (T)))));
8204 end Is_Variant_Record;
8206 -- Start of processing for Create_Constrained_Components
8209 pragma Assert (Subt /= Base_Type (Subt));
8210 pragma Assert (Typ = Base_Type (Typ));
8212 Set_First_Entity (Subt, Empty);
8213 Set_Last_Entity (Subt, Empty);
8215 -- Check whether constraint is fully static, in which case we can
8216 -- optimize the list of components.
8218 Discr_Val := First_Elmt (Constraints);
8220 while Present (Discr_Val) loop
8222 if not Is_OK_Static_Expression (Node (Discr_Val)) then
8227 Next_Elmt (Discr_Val);
8232 -- Inherit the discriminants of the parent type.
8234 Old_C := First_Discriminant (Typ);
8236 while Present (Old_C) loop
8237 New_C := Create_Component (Old_C);
8238 Set_Is_Public (New_C, Is_Public (Subt));
8239 Next_Discriminant (Old_C);
8243 and then Is_Variant_Record (Typ)
8245 Collect_Fixed_Components (Typ);
8249 Component_List (Type_Definition (Parent (Typ))),
8250 Governed_By => Assoc_List,
8252 Report_Errors => Errors);
8253 pragma Assert (not Errors);
8255 Create_All_Components;
8257 -- If the subtype declaration is created for a tagged type derivation
8258 -- with constraints, we retrieve the record definition of the parent
8259 -- type to select the components of the proper variant.
8262 and then Is_Tagged_Type (Typ)
8263 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
8265 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
8266 and then Is_Variant_Record (Parent_Type)
8268 Collect_Fixed_Components (Typ);
8272 Component_List (Type_Definition (Parent (Parent_Type))),
8273 Governed_By => Assoc_List,
8275 Report_Errors => Errors);
8276 pragma Assert (not Errors);
8278 -- If the tagged derivation has a type extension, collect all the
8279 -- new components therein.
8282 Record_Extension_Part (Type_Definition (Parent (Typ))))
8284 Old_C := First_Component (Typ);
8286 while Present (Old_C) loop
8287 if Original_Record_Component (Old_C) = Old_C
8288 and then Chars (Old_C) /= Name_uTag
8289 and then Chars (Old_C) /= Name_uParent
8290 and then Chars (Old_C) /= Name_uController
8292 Append_Elmt (Old_C, Comp_List);
8295 Next_Component (Old_C);
8299 Create_All_Components;
8302 -- If the discriminants are not static, or if this is a multi-level
8303 -- type extension, we have to include all the components of the
8306 Old_C := First_Component (Typ);
8308 while Present (Old_C) loop
8309 New_C := Create_Component (Old_C);
8313 Constrain_Component_Type
8314 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
8315 Set_Is_Public (New_C, Is_Public (Subt));
8317 Next_Component (Old_C);
8322 end Create_Constrained_Components;
8324 ------------------------------------------
8325 -- Decimal_Fixed_Point_Type_Declaration --
8326 ------------------------------------------
8328 procedure Decimal_Fixed_Point_Type_Declaration
8332 Loc : constant Source_Ptr := Sloc (Def);
8333 Digs_Expr : constant Node_Id := Digits_Expression (Def);
8334 Delta_Expr : constant Node_Id := Delta_Expression (Def);
8335 Implicit_Base : Entity_Id;
8341 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
8344 Check_Restriction (No_Fixed_Point, Def);
8346 -- Create implicit base type
8349 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
8350 Set_Etype (Implicit_Base, Implicit_Base);
8352 -- Analyze and process delta expression
8354 Analyze_And_Resolve (Delta_Expr, Universal_Real);
8356 Check_Delta_Expression (Delta_Expr);
8357 Delta_Val := Expr_Value_R (Delta_Expr);
8359 -- Check delta is power of 10, and determine scale value from it
8362 Val : Ureal := Delta_Val;
8365 Scale_Val := Uint_0;
8367 if Val < Ureal_1 then
8368 while Val < Ureal_1 loop
8369 Val := Val * Ureal_10;
8370 Scale_Val := Scale_Val + 1;
8373 if Scale_Val > 18 then
8374 Error_Msg_N ("scale exceeds maximum value of 18", Def);
8375 Scale_Val := UI_From_Int (+18);
8379 while Val > Ureal_1 loop
8380 Val := Val / Ureal_10;
8381 Scale_Val := Scale_Val - 1;
8384 if Scale_Val < -18 then
8385 Error_Msg_N ("scale is less than minimum value of -18", Def);
8386 Scale_Val := UI_From_Int (-18);
8390 if Val /= Ureal_1 then
8391 Error_Msg_N ("delta expression must be a power of 10", Def);
8392 Delta_Val := Ureal_10 ** (-Scale_Val);
8396 -- Set delta, scale and small (small = delta for decimal type)
8398 Set_Delta_Value (Implicit_Base, Delta_Val);
8399 Set_Scale_Value (Implicit_Base, Scale_Val);
8400 Set_Small_Value (Implicit_Base, Delta_Val);
8402 -- Analyze and process digits expression
8404 Analyze_And_Resolve (Digs_Expr, Any_Integer);
8405 Check_Digits_Expression (Digs_Expr);
8406 Digs_Val := Expr_Value (Digs_Expr);
8408 if Digs_Val > 18 then
8409 Digs_Val := UI_From_Int (+18);
8410 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8413 Set_Digits_Value (Implicit_Base, Digs_Val);
8414 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8416 -- Set range of base type from digits value for now. This will be
8417 -- expanded to represent the true underlying base range by Freeze.
8419 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8421 -- Set size to zero for now, size will be set at freeze time. We have
8422 -- to do this for ordinary fixed-point, because the size depends on
8423 -- the specified small, and we might as well do the same for decimal
8426 Init_Size_Align (Implicit_Base);
8428 -- Complete entity for first subtype
8430 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
8431 Set_Etype (T, Implicit_Base);
8432 Set_Size_Info (T, Implicit_Base);
8433 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
8434 Set_Digits_Value (T, Digs_Val);
8435 Set_Delta_Value (T, Delta_Val);
8436 Set_Small_Value (T, Delta_Val);
8437 Set_Scale_Value (T, Scale_Val);
8438 Set_Is_Constrained (T);
8440 -- If there are bounds given in the declaration use them as the
8441 -- bounds of the first named subtype.
8443 if Present (Real_Range_Specification (Def)) then
8445 RRS : constant Node_Id := Real_Range_Specification (Def);
8446 Low : constant Node_Id := Low_Bound (RRS);
8447 High : constant Node_Id := High_Bound (RRS);
8452 Analyze_And_Resolve (Low, Any_Real);
8453 Analyze_And_Resolve (High, Any_Real);
8454 Check_Real_Bound (Low);
8455 Check_Real_Bound (High);
8456 Low_Val := Expr_Value_R (Low);
8457 High_Val := Expr_Value_R (High);
8459 if Low_Val < (-Bound_Val) then
8461 ("range low bound too small for digits value", Low);
8462 Low_Val := -Bound_Val;
8465 if High_Val > Bound_Val then
8467 ("range high bound too large for digits value", High);
8468 High_Val := Bound_Val;
8471 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
8474 -- If no explicit range, use range that corresponds to given
8475 -- digits value. This will end up as the final range for the
8479 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
8482 end Decimal_Fixed_Point_Type_Declaration;
8484 -----------------------
8485 -- Derive_Subprogram --
8486 -----------------------
8488 procedure Derive_Subprogram
8489 (New_Subp : in out Entity_Id;
8490 Parent_Subp : Entity_Id;
8491 Derived_Type : Entity_Id;
8492 Parent_Type : Entity_Id;
8493 Actual_Subp : Entity_Id := Empty)
8496 New_Formal : Entity_Id;
8497 Same_Subt : constant Boolean :=
8498 Is_Scalar_Type (Parent_Type)
8499 and then Subtypes_Statically_Compatible (Parent_Type, Derived_Type);
8500 Visible_Subp : Entity_Id := Parent_Subp;
8502 function Is_Private_Overriding return Boolean;
8503 -- If Subp is a private overriding of a visible operation, the in-
8504 -- herited operation derives from the overridden op (even though
8505 -- its body is the overriding one) and the inherited operation is
8506 -- visible now. See sem_disp to see the details of the handling of
8507 -- the overridden subprogram, which is removed from the list of
8508 -- primitive operations of the type. The overridden subprogram is
8509 -- saved locally in Visible_Subp, and used to diagnose abstract
8510 -- operations that need overriding in the derived type.
8512 procedure Replace_Type (Id, New_Id : Entity_Id);
8513 -- When the type is an anonymous access type, create a new access type
8514 -- designating the derived type.
8516 procedure Set_Derived_Name;
8517 -- This procedure sets the appropriate Chars name for New_Subp. This
8518 -- is normally just a copy of the parent name. An exception arises for
8519 -- type support subprograms, where the name is changed to reflect the
8520 -- name of the derived type, e.g. if type foo is derived from type bar,
8521 -- then a procedure barDA is derived with a name fooDA.
8523 ---------------------------
8524 -- Is_Private_Overriding --
8525 ---------------------------
8527 function Is_Private_Overriding return Boolean is
8531 Prev := Homonym (Parent_Subp);
8533 -- The visible operation that is overriden is a homonym of
8534 -- the parent subprogram. We scan the homonym chain to find
8535 -- the one whose alias is the subprogram we are deriving.
8537 while Present (Prev) loop
8538 if Is_Dispatching_Operation (Parent_Subp)
8539 and then Present (Prev)
8540 and then Ekind (Prev) = Ekind (Parent_Subp)
8541 and then Alias (Prev) = Parent_Subp
8542 and then Scope (Parent_Subp) = Scope (Prev)
8543 and then not Is_Hidden (Prev)
8545 Visible_Subp := Prev;
8549 Prev := Homonym (Prev);
8553 end Is_Private_Overriding;
8559 procedure Replace_Type (Id, New_Id : Entity_Id) is
8560 Acc_Type : Entity_Id;
8564 -- When the type is an anonymous access type, create a new access
8565 -- type designating the derived type. This itype must be elaborated
8566 -- at the point of the derivation, not on subsequent calls that may
8567 -- be out of the proper scope for Gigi, so we insert a reference to
8568 -- it after the derivation.
8570 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
8572 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
8575 if Ekind (Desig_Typ) = E_Record_Type_With_Private
8576 and then Present (Full_View (Desig_Typ))
8577 and then not Is_Private_Type (Parent_Type)
8579 Desig_Typ := Full_View (Desig_Typ);
8582 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
8583 Acc_Type := New_Copy (Etype (Id));
8584 Set_Etype (Acc_Type, Acc_Type);
8585 Set_Scope (Acc_Type, New_Subp);
8587 -- Compute size of anonymous access type.
8589 if Is_Array_Type (Desig_Typ)
8590 and then not Is_Constrained (Desig_Typ)
8592 Init_Size (Acc_Type, 2 * System_Address_Size);
8594 Init_Size (Acc_Type, System_Address_Size);
8597 Init_Alignment (Acc_Type);
8599 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
8601 Set_Etype (New_Id, Acc_Type);
8602 Set_Scope (New_Id, New_Subp);
8604 -- Create a reference to it.
8606 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
8607 Set_Itype (IR, Acc_Type);
8608 Insert_After (Parent (Derived_Type), IR);
8611 Set_Etype (New_Id, Etype (Id));
8614 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
8616 (Ekind (Etype (Id)) = E_Record_Type_With_Private
8617 and then Present (Full_View (Etype (Id)))
8618 and then Base_Type (Full_View (Etype (Id))) =
8619 Base_Type (Parent_Type))
8622 -- Constraint checks on formals are generated during expansion,
8623 -- based on the signature of the original subprogram. The bounds
8624 -- of the derived type are not relevant, and thus we can use
8625 -- the base type for the formals. However, the return type may be
8626 -- used in a context that requires that the proper static bounds
8627 -- be used (a case statement, for example) and for those cases
8628 -- we must use the derived type (first subtype), not its base.
8630 if Etype (Id) = Parent_Type
8633 Set_Etype (New_Id, Derived_Type);
8635 Set_Etype (New_Id, Base_Type (Derived_Type));
8639 Set_Etype (New_Id, Etype (Id));
8643 ----------------------
8644 -- Set_Derived_Name --
8645 ----------------------
8647 procedure Set_Derived_Name is
8648 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
8650 if Nm = TSS_Null then
8651 Set_Chars (New_Subp, Chars (Parent_Subp));
8653 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
8655 end Set_Derived_Name;
8657 -- Start of processing for Derive_Subprogram
8661 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
8662 Set_Ekind (New_Subp, Ekind (Parent_Subp));
8664 -- Check whether the inherited subprogram is a private operation that
8665 -- should be inherited but not yet made visible. Such subprograms can
8666 -- become visible at a later point (e.g., the private part of a public
8667 -- child unit) via Declare_Inherited_Private_Subprograms. If the
8668 -- following predicate is true, then this is not such a private
8669 -- operation and the subprogram simply inherits the name of the parent
8670 -- subprogram. Note the special check for the names of controlled
8671 -- operations, which are currently exempted from being inherited with
8672 -- a hidden name because they must be findable for generation of
8673 -- implicit run-time calls.
8675 if not Is_Hidden (Parent_Subp)
8676 or else Is_Internal (Parent_Subp)
8677 or else Is_Private_Overriding
8678 or else Is_Internal_Name (Chars (Parent_Subp))
8679 or else Chars (Parent_Subp) = Name_Initialize
8680 or else Chars (Parent_Subp) = Name_Adjust
8681 or else Chars (Parent_Subp) = Name_Finalize
8685 -- If parent is hidden, this can be a regular derivation if the
8686 -- parent is immediately visible in a non-instantiating context,
8687 -- or if we are in the private part of an instance. This test
8688 -- should still be refined ???
8690 -- The test for In_Instance_Not_Visible avoids inheriting the
8691 -- derived operation as a non-visible operation in cases where
8692 -- the parent subprogram might not be visible now, but was
8693 -- visible within the original generic, so it would be wrong
8694 -- to make the inherited subprogram non-visible now. (Not
8695 -- clear if this test is fully correct; are there any cases
8696 -- where we should declare the inherited operation as not
8697 -- visible to avoid it being overridden, e.g., when the
8698 -- parent type is a generic actual with private primitives ???)
8700 -- (they should be treated the same as other private inherited
8701 -- subprograms, but it's not clear how to do this cleanly). ???
8703 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
8704 and then Is_Immediately_Visible (Parent_Subp)
8705 and then not In_Instance)
8706 or else In_Instance_Not_Visible
8710 -- The type is inheriting a private operation, so enter
8711 -- it with a special name so it can't be overridden.
8714 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
8717 Set_Parent (New_Subp, Parent (Derived_Type));
8718 Replace_Type (Parent_Subp, New_Subp);
8719 Conditional_Delay (New_Subp, Parent_Subp);
8721 Formal := First_Formal (Parent_Subp);
8722 while Present (Formal) loop
8723 New_Formal := New_Copy (Formal);
8725 -- Normally we do not go copying parents, but in the case of
8726 -- formals, we need to link up to the declaration (which is
8727 -- the parameter specification), and it is fine to link up to
8728 -- the original formal's parameter specification in this case.
8730 Set_Parent (New_Formal, Parent (Formal));
8732 Append_Entity (New_Formal, New_Subp);
8734 Replace_Type (Formal, New_Formal);
8735 Next_Formal (Formal);
8738 -- If this derivation corresponds to a tagged generic actual, then
8739 -- primitive operations rename those of the actual. Otherwise the
8740 -- primitive operations rename those of the parent type, If the
8741 -- parent renames an intrinsic operator, so does the new subprogram.
8742 -- We except concatenation, which is always properly typed, and does
8743 -- not get expanded as other intrinsic operations.
8745 if No (Actual_Subp) then
8746 if Is_Intrinsic_Subprogram (Parent_Subp) then
8747 Set_Is_Intrinsic_Subprogram (New_Subp);
8749 if Present (Alias (Parent_Subp))
8750 and then Chars (Parent_Subp) /= Name_Op_Concat
8752 Set_Alias (New_Subp, Alias (Parent_Subp));
8754 Set_Alias (New_Subp, Parent_Subp);
8758 Set_Alias (New_Subp, Parent_Subp);
8762 Set_Alias (New_Subp, Actual_Subp);
8765 -- Derived subprograms of a tagged type must inherit the convention
8766 -- of the parent subprogram (a requirement of AI-117). Derived
8767 -- subprograms of untagged types simply get convention Ada by default.
8769 if Is_Tagged_Type (Derived_Type) then
8770 Set_Convention (New_Subp, Convention (Parent_Subp));
8773 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
8774 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
8776 if Ekind (Parent_Subp) = E_Procedure then
8777 Set_Is_Valued_Procedure
8778 (New_Subp, Is_Valued_Procedure (Parent_Subp));
8781 -- A derived function with a controlling result is abstract.
8782 -- If the Derived_Type is a nonabstract formal generic derived
8783 -- type, then inherited operations are not abstract: check is
8784 -- done at instantiation time. If the derivation is for a generic
8785 -- actual, the function is not abstract unless the actual is.
8787 if Is_Generic_Type (Derived_Type)
8788 and then not Is_Abstract (Derived_Type)
8792 elsif Is_Abstract (Alias (New_Subp))
8793 or else (Is_Tagged_Type (Derived_Type)
8794 and then Etype (New_Subp) = Derived_Type
8795 and then No (Actual_Subp))
8797 Set_Is_Abstract (New_Subp);
8799 -- Finally, if the parent type is abstract we must verify that all
8800 -- inherited operations are either non-abstract or overridden, or
8801 -- that the derived type itself is abstract (this check is performed
8802 -- at the end of a package declaration, in Check_Abstract_Overriding).
8803 -- A private overriding in the parent type will not be visible in the
8804 -- derivation if we are not in an inner package or in a child unit of
8805 -- the parent type, in which case the abstractness of the inherited
8806 -- operation is carried to the new subprogram.
8808 elsif Is_Abstract (Parent_Type)
8809 and then not In_Open_Scopes (Scope (Parent_Type))
8810 and then Is_Private_Overriding
8811 and then Is_Abstract (Visible_Subp)
8813 Set_Alias (New_Subp, Visible_Subp);
8814 Set_Is_Abstract (New_Subp);
8817 New_Overloaded_Entity (New_Subp, Derived_Type);
8819 -- Check for case of a derived subprogram for the instantiation
8820 -- of a formal derived tagged type, if so mark the subprogram as
8821 -- dispatching and inherit the dispatching attributes of the
8822 -- parent subprogram. The derived subprogram is effectively a
8823 -- renaming of the actual subprogram, so it needs to have the
8824 -- same attributes as the actual.
8826 if Present (Actual_Subp)
8827 and then Is_Dispatching_Operation (Parent_Subp)
8829 Set_Is_Dispatching_Operation (New_Subp);
8830 if Present (DTC_Entity (Parent_Subp)) then
8831 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
8832 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
8836 -- Indicate that a derived subprogram does not require a body
8837 -- and that it does not require processing of default expressions.
8839 Set_Has_Completion (New_Subp);
8840 Set_Default_Expressions_Processed (New_Subp);
8842 if Ekind (New_Subp) = E_Function then
8843 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
8845 end Derive_Subprogram;
8847 ------------------------
8848 -- Derive_Subprograms --
8849 ------------------------
8851 procedure Derive_Subprograms
8852 (Parent_Type : Entity_Id;
8853 Derived_Type : Entity_Id;
8854 Generic_Actual : Entity_Id := Empty)
8856 Op_List : constant Elist_Id :=
8857 Collect_Primitive_Operations (Parent_Type);
8858 Act_List : Elist_Id;
8862 New_Subp : Entity_Id := Empty;
8863 Parent_Base : Entity_Id;
8866 if Ekind (Parent_Type) = E_Record_Type_With_Private
8867 and then Has_Discriminants (Parent_Type)
8868 and then Present (Full_View (Parent_Type))
8870 Parent_Base := Full_View (Parent_Type);
8872 Parent_Base := Parent_Type;
8875 Elmt := First_Elmt (Op_List);
8877 if Present (Generic_Actual) then
8878 Act_List := Collect_Primitive_Operations (Generic_Actual);
8879 Act_Elmt := First_Elmt (Act_List);
8881 Act_Elmt := No_Elmt;
8884 -- Literals are derived earlier in the process of building the
8885 -- derived type, and are skipped here.
8887 while Present (Elmt) loop
8888 Subp := Node (Elmt);
8890 if Ekind (Subp) /= E_Enumeration_Literal then
8891 if No (Generic_Actual) then
8893 (New_Subp, Subp, Derived_Type, Parent_Base);
8896 Derive_Subprogram (New_Subp, Subp,
8897 Derived_Type, Parent_Base, Node (Act_Elmt));
8898 Next_Elmt (Act_Elmt);
8904 end Derive_Subprograms;
8906 --------------------------------
8907 -- Derived_Standard_Character --
8908 --------------------------------
8910 procedure Derived_Standard_Character
8912 Parent_Type : Entity_Id;
8913 Derived_Type : Entity_Id)
8915 Loc : constant Source_Ptr := Sloc (N);
8916 Def : constant Node_Id := Type_Definition (N);
8917 Indic : constant Node_Id := Subtype_Indication (Def);
8918 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8919 Implicit_Base : constant Entity_Id :=
8921 (E_Enumeration_Type, N, Derived_Type, 'B');
8927 Discard_Node (Process_Subtype (Indic, N));
8929 Set_Etype (Implicit_Base, Parent_Base);
8930 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
8931 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
8933 Set_Is_Character_Type (Implicit_Base, True);
8934 Set_Has_Delayed_Freeze (Implicit_Base);
8936 -- The bounds of the implicit base are the bounds of the parent base.
8937 -- Note that their type is the parent base.
8939 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
8940 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
8942 Set_Scalar_Range (Implicit_Base,
8947 Conditional_Delay (Derived_Type, Parent_Type);
8949 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
8950 Set_Etype (Derived_Type, Implicit_Base);
8951 Set_Size_Info (Derived_Type, Parent_Type);
8953 if Unknown_RM_Size (Derived_Type) then
8954 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8957 Set_Is_Character_Type (Derived_Type, True);
8959 if Nkind (Indic) /= N_Subtype_Indication then
8961 -- If no explicit constraint, the bounds are those
8962 -- of the parent type.
8964 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
8965 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
8966 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
8969 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
8971 -- Because the implicit base is used in the conversion of the bounds,
8972 -- we have to freeze it now. This is similar to what is done for
8973 -- numeric types, and it equally suspicious, but otherwise a non-
8974 -- static bound will have a reference to an unfrozen type, which is
8975 -- rejected by Gigi (???).
8977 Freeze_Before (N, Implicit_Base);
8978 end Derived_Standard_Character;
8980 ------------------------------
8981 -- Derived_Type_Declaration --
8982 ------------------------------
8984 procedure Derived_Type_Declaration
8987 Is_Completion : Boolean)
8989 Def : constant Node_Id := Type_Definition (N);
8990 Indic : constant Node_Id := Subtype_Indication (Def);
8991 Extension : constant Node_Id := Record_Extension_Part (Def);
8992 Parent_Type : Entity_Id;
8993 Parent_Scope : Entity_Id;
8997 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
8999 if Parent_Type = Any_Type
9000 or else Etype (Parent_Type) = Any_Type
9001 or else (Is_Class_Wide_Type (Parent_Type)
9002 and then Etype (Parent_Type) = T)
9004 -- If Parent_Type is undefined or illegal, make new type into
9005 -- a subtype of Any_Type, and set a few attributes to prevent
9006 -- cascaded errors. If this is a self-definition, emit error now.
9009 or else T = Etype (Parent_Type)
9011 Error_Msg_N ("type cannot be used in its own definition", Indic);
9014 Set_Ekind (T, Ekind (Parent_Type));
9015 Set_Etype (T, Any_Type);
9016 Set_Scalar_Range (T, Scalar_Range (Any_Type));
9018 if Is_Tagged_Type (T) then
9019 Set_Primitive_Operations (T, New_Elmt_List);
9024 elsif Is_Unchecked_Union (Parent_Type) then
9025 Error_Msg_N ("cannot derive from Unchecked_Union type", N);
9028 -- Only composite types other than array types are allowed to have
9031 if Present (Discriminant_Specifications (N))
9032 and then (Is_Elementary_Type (Parent_Type)
9033 or else Is_Array_Type (Parent_Type))
9034 and then not Error_Posted (N)
9037 ("elementary or array type cannot have discriminants",
9038 Defining_Identifier (First (Discriminant_Specifications (N))));
9039 Set_Has_Discriminants (T, False);
9042 -- In Ada 83, a derived type defined in a package specification cannot
9043 -- be used for further derivation until the end of its visible part.
9044 -- Note that derivation in the private part of the package is allowed.
9047 and then Is_Derived_Type (Parent_Type)
9048 and then In_Visible_Part (Scope (Parent_Type))
9050 if Ada_83 and then Comes_From_Source (Indic) then
9052 ("(Ada 83): premature use of type for derivation", Indic);
9056 -- Check for early use of incomplete or private type
9058 if Ekind (Parent_Type) = E_Void
9059 or else Ekind (Parent_Type) = E_Incomplete_Type
9061 Error_Msg_N ("premature derivation of incomplete type", Indic);
9064 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
9065 and then not Is_Generic_Type (Parent_Type)
9066 and then not Is_Generic_Type (Root_Type (Parent_Type))
9067 and then not Is_Generic_Actual_Type (Parent_Type))
9068 or else Has_Private_Component (Parent_Type)
9070 -- The ancestor type of a formal type can be incomplete, in which
9071 -- case only the operations of the partial view are available in
9072 -- the generic. Subsequent checks may be required when the full
9073 -- view is analyzed, to verify that derivation from a tagged type
9074 -- has an extension.
9076 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
9079 elsif No (Underlying_Type (Parent_Type))
9080 or else Has_Private_Component (Parent_Type)
9083 ("premature derivation of derived or private type", Indic);
9085 -- Flag the type itself as being in error, this prevents some
9086 -- nasty problems with people looking at the malformed type.
9088 Set_Error_Posted (T);
9090 -- Check that within the immediate scope of an untagged partial
9091 -- view it's illegal to derive from the partial view if the
9092 -- full view is tagged. (7.3(7))
9094 -- We verify that the Parent_Type is a partial view by checking
9095 -- that it is not a Full_Type_Declaration (i.e. a private type or
9096 -- private extension declaration), to distinguish a partial view
9097 -- from a derivation from a private type which also appears as
9100 elsif Present (Full_View (Parent_Type))
9101 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
9102 and then not Is_Tagged_Type (Parent_Type)
9103 and then Is_Tagged_Type (Full_View (Parent_Type))
9105 Parent_Scope := Scope (T);
9106 while Present (Parent_Scope)
9107 and then Parent_Scope /= Standard_Standard
9109 if Parent_Scope = Scope (Parent_Type) then
9111 ("premature derivation from type with tagged full view",
9115 Parent_Scope := Scope (Parent_Scope);
9120 -- Check that form of derivation is appropriate
9122 Taggd := Is_Tagged_Type (Parent_Type);
9124 -- Perhaps the parent type should be changed to the class-wide type's
9125 -- specific type in this case to prevent cascading errors ???
9127 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
9128 Error_Msg_N ("parent type must not be a class-wide type", Indic);
9132 if Present (Extension) and then not Taggd then
9134 ("type derived from untagged type cannot have extension", Indic);
9136 elsif No (Extension) and then Taggd then
9137 -- If this is within a private part (or body) of a generic
9138 -- instantiation then the derivation is allowed (the parent
9139 -- type can only appear tagged in this case if it's a generic
9140 -- actual type, since it would otherwise have been rejected
9141 -- in the analysis of the generic template).
9143 if not Is_Generic_Actual_Type (Parent_Type)
9144 or else In_Visible_Part (Scope (Parent_Type))
9147 ("type derived from tagged type must have extension", Indic);
9151 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
9152 end Derived_Type_Declaration;
9154 ----------------------------------
9155 -- Enumeration_Type_Declaration --
9156 ----------------------------------
9158 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9165 -- Create identifier node representing lower bound
9167 B_Node := New_Node (N_Identifier, Sloc (Def));
9168 L := First (Literals (Def));
9169 Set_Chars (B_Node, Chars (L));
9170 Set_Entity (B_Node, L);
9171 Set_Etype (B_Node, T);
9172 Set_Is_Static_Expression (B_Node, True);
9174 R_Node := New_Node (N_Range, Sloc (Def));
9175 Set_Low_Bound (R_Node, B_Node);
9177 Set_Ekind (T, E_Enumeration_Type);
9178 Set_First_Literal (T, L);
9180 Set_Is_Constrained (T);
9184 -- Loop through literals of enumeration type setting pos and rep values
9185 -- except that if the Ekind is already set, then it means that the
9186 -- literal was already constructed (case of a derived type declaration
9187 -- and we should not disturb the Pos and Rep values.
9189 while Present (L) loop
9190 if Ekind (L) /= E_Enumeration_Literal then
9191 Set_Ekind (L, E_Enumeration_Literal);
9192 Set_Enumeration_Pos (L, Ev);
9193 Set_Enumeration_Rep (L, Ev);
9194 Set_Is_Known_Valid (L, True);
9198 New_Overloaded_Entity (L);
9199 Generate_Definition (L);
9200 Set_Convention (L, Convention_Intrinsic);
9202 if Nkind (L) = N_Defining_Character_Literal then
9203 Set_Is_Character_Type (T, True);
9210 -- Now create a node representing upper bound
9212 B_Node := New_Node (N_Identifier, Sloc (Def));
9213 Set_Chars (B_Node, Chars (Last (Literals (Def))));
9214 Set_Entity (B_Node, Last (Literals (Def)));
9215 Set_Etype (B_Node, T);
9216 Set_Is_Static_Expression (B_Node, True);
9218 Set_High_Bound (R_Node, B_Node);
9219 Set_Scalar_Range (T, R_Node);
9220 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
9223 -- Set Discard_Names if configuration pragma set, or if there is
9224 -- a parameterless pragma in the current declarative region
9226 if Global_Discard_Names
9227 or else Discard_Names (Scope (T))
9229 Set_Discard_Names (T);
9232 -- Process end label if there is one
9234 if Present (Def) then
9235 Process_End_Label (Def, 'e', T);
9237 end Enumeration_Type_Declaration;
9239 ---------------------------------
9240 -- Expand_To_Stored_Constraint --
9241 ---------------------------------
9243 function Expand_To_Stored_Constraint
9245 Constraint : Elist_Id) return Elist_Id
9247 Explicitly_Discriminated_Type : Entity_Id;
9248 Expansion : Elist_Id;
9249 Discriminant : Entity_Id;
9251 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
9252 -- Find the nearest type that actually specifies discriminants.
9254 ---------------------------------
9255 -- Type_With_Explicit_Discrims --
9256 ---------------------------------
9258 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
9259 Typ : constant E := Base_Type (Id);
9262 if Ekind (Typ) in Incomplete_Or_Private_Kind then
9263 if Present (Full_View (Typ)) then
9264 return Type_With_Explicit_Discrims (Full_View (Typ));
9268 if Has_Discriminants (Typ) then
9273 if Etype (Typ) = Typ then
9275 elsif Has_Discriminants (Typ) then
9278 return Type_With_Explicit_Discrims (Etype (Typ));
9281 end Type_With_Explicit_Discrims;
9283 -- Start of processing for Expand_To_Stored_Constraint
9287 or else Is_Empty_Elmt_List (Constraint)
9292 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
9294 if No (Explicitly_Discriminated_Type) then
9298 Expansion := New_Elmt_List;
9301 First_Stored_Discriminant (Explicitly_Discriminated_Type);
9303 while Present (Discriminant) loop
9306 Get_Discriminant_Value (
9307 Discriminant, Explicitly_Discriminated_Type, Constraint),
9310 Next_Stored_Discriminant (Discriminant);
9314 end Expand_To_Stored_Constraint;
9316 --------------------
9317 -- Find_Type_Name --
9318 --------------------
9320 function Find_Type_Name (N : Node_Id) return Entity_Id is
9321 Id : constant Entity_Id := Defining_Identifier (N);
9327 -- Find incomplete declaration, if some was given.
9329 Prev := Current_Entity_In_Scope (Id);
9331 if Present (Prev) then
9333 -- Previous declaration exists. Error if not incomplete/private case
9334 -- except if previous declaration is implicit, etc. Enter_Name will
9335 -- emit error if appropriate.
9337 Prev_Par := Parent (Prev);
9339 if not Is_Incomplete_Or_Private_Type (Prev) then
9343 elsif Nkind (N) /= N_Full_Type_Declaration
9344 and then Nkind (N) /= N_Task_Type_Declaration
9345 and then Nkind (N) /= N_Protected_Type_Declaration
9347 -- Completion must be a full type declarations (RM 7.3(4))
9349 Error_Msg_Sloc := Sloc (Prev);
9350 Error_Msg_NE ("invalid completion of }", Id, Prev);
9352 -- Set scope of Id to avoid cascaded errors. Entity is never
9353 -- examined again, except when saving globals in generics.
9355 Set_Scope (Id, Current_Scope);
9358 -- Case of full declaration of incomplete type
9360 elsif Ekind (Prev) = E_Incomplete_Type then
9362 -- Indicate that the incomplete declaration has a matching
9363 -- full declaration. The defining occurrence of the incomplete
9364 -- declaration remains the visible one, and the procedure
9365 -- Get_Full_View dereferences it whenever the type is used.
9367 if Present (Full_View (Prev)) then
9368 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9371 Set_Full_View (Prev, Id);
9372 Append_Entity (Id, Current_Scope);
9373 Set_Is_Public (Id, Is_Public (Prev));
9374 Set_Is_Internal (Id);
9377 -- Case of full declaration of private type
9380 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9381 if Etype (Prev) /= Prev then
9383 -- Prev is a private subtype or a derived type, and needs
9386 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9389 elsif Ekind (Prev) = E_Private_Type
9391 (Nkind (N) = N_Task_Type_Declaration
9392 or else Nkind (N) = N_Protected_Type_Declaration)
9395 ("completion of nonlimited type cannot be limited", N);
9398 elsif Nkind (N) /= N_Full_Type_Declaration
9399 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9401 Error_Msg_N ("full view of private extension must be"
9402 & " an extension", N);
9404 elsif not (Abstract_Present (Parent (Prev)))
9405 and then Abstract_Present (Type_Definition (N))
9407 Error_Msg_N ("full view of non-abstract extension cannot"
9408 & " be abstract", N);
9411 if not In_Private_Part (Current_Scope) then
9413 ("declaration of full view must appear in private part", N);
9416 Copy_And_Swap (Prev, Id);
9417 Set_Has_Private_Declaration (Prev);
9418 Set_Has_Private_Declaration (Id);
9420 -- If no error, propagate freeze_node from private to full view.
9421 -- It may have been generated for an early operational item.
9423 if Present (Freeze_Node (Id))
9424 and then Serious_Errors_Detected = 0
9425 and then No (Full_View (Id))
9427 Set_Freeze_Node (Prev, Freeze_Node (Id));
9428 Set_Freeze_Node (Id, Empty);
9429 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
9432 Set_Full_View (Id, Prev);
9436 -- Verify that full declaration conforms to incomplete one
9438 if Is_Incomplete_Or_Private_Type (Prev)
9439 and then Present (Discriminant_Specifications (Prev_Par))
9441 if Present (Discriminant_Specifications (N)) then
9442 if Ekind (Prev) = E_Incomplete_Type then
9443 Check_Discriminant_Conformance (N, Prev, Prev);
9445 Check_Discriminant_Conformance (N, Prev, Id);
9450 ("missing discriminants in full type declaration", N);
9452 -- To avoid cascaded errors on subsequent use, share the
9453 -- discriminants of the partial view.
9455 Set_Discriminant_Specifications (N,
9456 Discriminant_Specifications (Prev_Par));
9460 -- A prior untagged private type can have an associated
9461 -- class-wide type due to use of the class attribute,
9462 -- and in this case also the full type is required to
9466 and then (Is_Tagged_Type (Prev)
9467 or else Present (Class_Wide_Type (Prev)))
9469 -- The full declaration is either a tagged record or an
9470 -- extension otherwise this is an error
9472 if Nkind (Type_Definition (N)) = N_Record_Definition then
9473 if not Tagged_Present (Type_Definition (N)) then
9475 ("full declaration of } must be tagged", Prev, Id);
9476 Set_Is_Tagged_Type (Id);
9477 Set_Primitive_Operations (Id, New_Elmt_List);
9480 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
9481 if No (Record_Extension_Part (Type_Definition (N))) then
9483 "full declaration of } must be a record extension",
9485 Set_Is_Tagged_Type (Id);
9486 Set_Primitive_Operations (Id, New_Elmt_List);
9491 ("full declaration of } must be a tagged type", Prev, Id);
9499 -- New type declaration
9506 -------------------------
9507 -- Find_Type_Of_Object --
9508 -------------------------
9510 function Find_Type_Of_Object
9512 Related_Nod : Node_Id) return Entity_Id
9514 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
9515 P : constant Node_Id := Parent (Obj_Def);
9520 -- Case of an anonymous array subtype
9522 if Def_Kind = N_Constrained_Array_Definition
9523 or else Def_Kind = N_Unconstrained_Array_Definition
9526 Array_Type_Declaration (T, Obj_Def);
9528 -- Create an explicit subtype whenever possible.
9530 elsif Nkind (P) /= N_Component_Declaration
9531 and then Def_Kind = N_Subtype_Indication
9533 -- Base name of subtype on object name, which will be unique in
9534 -- the current scope.
9536 -- If this is a duplicate declaration, return base type, to avoid
9537 -- generating duplicate anonymous types.
9539 if Error_Posted (P) then
9540 Analyze (Subtype_Mark (Obj_Def));
9541 return Entity (Subtype_Mark (Obj_Def));
9546 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
9548 T := Make_Defining_Identifier (Sloc (P), Nam);
9550 Insert_Action (Obj_Def,
9551 Make_Subtype_Declaration (Sloc (P),
9552 Defining_Identifier => T,
9553 Subtype_Indication => Relocate_Node (Obj_Def)));
9555 -- This subtype may need freezing and it will not be done
9556 -- automatically if the object declaration is not in a
9557 -- declarative part. Since this is an object declaration, the
9558 -- type cannot always be frozen here. Deferred constants do not
9559 -- freeze their type (which often enough will be private).
9561 if Nkind (P) = N_Object_Declaration
9562 and then Constant_Present (P)
9563 and then No (Expression (P))
9568 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
9572 T := Process_Subtype (Obj_Def, Related_Nod);
9576 end Find_Type_Of_Object;
9578 --------------------------------
9579 -- Find_Type_Of_Subtype_Indic --
9580 --------------------------------
9582 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
9586 -- Case of subtype mark with a constraint
9588 if Nkind (S) = N_Subtype_Indication then
9589 Find_Type (Subtype_Mark (S));
9590 Typ := Entity (Subtype_Mark (S));
9593 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
9596 ("incorrect constraint for this kind of type", Constraint (S));
9597 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
9600 -- Otherwise we have a subtype mark without a constraint
9602 elsif Error_Posted (S) then
9603 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
9611 if Typ = Standard_Wide_Character
9612 or else Typ = Standard_Wide_String
9614 Check_Restriction (No_Wide_Characters, S);
9618 end Find_Type_Of_Subtype_Indic;
9620 -------------------------------------
9621 -- Floating_Point_Type_Declaration --
9622 -------------------------------------
9624 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9625 Digs : constant Node_Id := Digits_Expression (Def);
9627 Base_Typ : Entity_Id;
9628 Implicit_Base : Entity_Id;
9631 function Can_Derive_From (E : Entity_Id) return Boolean;
9632 -- Find if given digits value allows derivation from specified type
9634 ---------------------
9635 -- Can_Derive_From --
9636 ---------------------
9638 function Can_Derive_From (E : Entity_Id) return Boolean is
9639 Spec : constant Entity_Id := Real_Range_Specification (Def);
9642 if Digs_Val > Digits_Value (E) then
9646 if Present (Spec) then
9647 if Expr_Value_R (Type_Low_Bound (E)) >
9648 Expr_Value_R (Low_Bound (Spec))
9653 if Expr_Value_R (Type_High_Bound (E)) <
9654 Expr_Value_R (High_Bound (Spec))
9661 end Can_Derive_From;
9663 -- Start of processing for Floating_Point_Type_Declaration
9666 Check_Restriction (No_Floating_Point, Def);
9668 -- Create an implicit base type
9671 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
9673 -- Analyze and verify digits value
9675 Analyze_And_Resolve (Digs, Any_Integer);
9676 Check_Digits_Expression (Digs);
9677 Digs_Val := Expr_Value (Digs);
9679 -- Process possible range spec and find correct type to derive from
9681 Process_Real_Range_Specification (Def);
9683 if Can_Derive_From (Standard_Short_Float) then
9684 Base_Typ := Standard_Short_Float;
9685 elsif Can_Derive_From (Standard_Float) then
9686 Base_Typ := Standard_Float;
9687 elsif Can_Derive_From (Standard_Long_Float) then
9688 Base_Typ := Standard_Long_Float;
9689 elsif Can_Derive_From (Standard_Long_Long_Float) then
9690 Base_Typ := Standard_Long_Long_Float;
9692 -- If we can't derive from any existing type, use long long float
9693 -- and give appropriate message explaining the problem.
9696 Base_Typ := Standard_Long_Long_Float;
9698 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
9699 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
9700 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
9704 ("range too large for any predefined type",
9705 Real_Range_Specification (Def));
9709 -- If there are bounds given in the declaration use them as the bounds
9710 -- of the type, otherwise use the bounds of the predefined base type
9711 -- that was chosen based on the Digits value.
9713 if Present (Real_Range_Specification (Def)) then
9714 Set_Scalar_Range (T, Real_Range_Specification (Def));
9715 Set_Is_Constrained (T);
9717 -- The bounds of this range must be converted to machine numbers
9718 -- in accordance with RM 4.9(38).
9720 Bound := Type_Low_Bound (T);
9722 if Nkind (Bound) = N_Real_Literal then
9724 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
9725 Set_Is_Machine_Number (Bound);
9728 Bound := Type_High_Bound (T);
9730 if Nkind (Bound) = N_Real_Literal then
9732 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
9733 Set_Is_Machine_Number (Bound);
9737 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
9740 -- Complete definition of implicit base and declared first subtype
9742 Set_Etype (Implicit_Base, Base_Typ);
9744 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
9745 Set_Size_Info (Implicit_Base, (Base_Typ));
9746 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
9747 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
9748 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
9749 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
9751 Set_Ekind (T, E_Floating_Point_Subtype);
9752 Set_Etype (T, Implicit_Base);
9754 Set_Size_Info (T, (Implicit_Base));
9755 Set_RM_Size (T, RM_Size (Implicit_Base));
9756 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
9757 Set_Digits_Value (T, Digs_Val);
9759 end Floating_Point_Type_Declaration;
9761 ----------------------------
9762 -- Get_Discriminant_Value --
9763 ----------------------------
9765 -- This is the situation...
9767 -- There is a non-derived type
9769 -- type T0 (Dx, Dy, Dz...)
9771 -- There are zero or more levels of derivation, with each
9772 -- derivation either purely inheriting the discriminants, or
9773 -- defining its own.
9775 -- type Ti is new Ti-1
9777 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
9779 -- subtype Ti is ...
9781 -- The subtype issue is avoided by the use of
9782 -- Original_Record_Component, and the fact that derived subtypes
9783 -- also derive the constraints.
9785 -- This chain leads back from
9787 -- Typ_For_Constraint
9789 -- Typ_For_Constraint has discriminants, and the value for each
9790 -- discriminant is given by its corresponding Elmt of Constraints.
9792 -- Discriminant is some discriminant in this hierarchy.
9794 -- We need to return its value.
9796 -- We do this by recursively searching each level, and looking for
9797 -- Discriminant. Once we get to the bottom, we start backing up
9798 -- returning the value for it which may in turn be a discriminant
9799 -- further up, so on the backup we continue the substitution.
9801 function Get_Discriminant_Value
9802 (Discriminant : Entity_Id;
9803 Typ_For_Constraint : Entity_Id;
9804 Constraint : Elist_Id) return Node_Id
9806 function Search_Derivation_Levels
9808 Discrim_Values : Elist_Id;
9809 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
9810 -- This is the routine that performs the recursive search of levels
9811 -- as described above.
9813 ------------------------------
9814 -- Search_Derivation_Levels --
9815 ------------------------------
9817 function Search_Derivation_Levels
9819 Discrim_Values : Elist_Id;
9820 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
9824 Result : Node_Or_Entity_Id;
9825 Result_Entity : Node_Id;
9828 -- If inappropriate type, return Error, this happens only in
9829 -- cascaded error situations, and we want to avoid a blow up.
9831 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
9835 -- Look deeper if possible. Use Stored_Constraints only for
9836 -- untagged types. For tagged types use the given constraint.
9837 -- This asymmetry needs explanation???
9839 if not Stored_Discrim_Values
9840 and then Present (Stored_Constraint (Ti))
9841 and then not Is_Tagged_Type (Ti)
9844 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
9847 Td : constant Entity_Id := Etype (Ti);
9851 Result := Discriminant;
9854 if Present (Stored_Constraint (Ti)) then
9856 Search_Derivation_Levels
9857 (Td, Stored_Constraint (Ti), True);
9860 Search_Derivation_Levels
9861 (Td, Discrim_Values, Stored_Discrim_Values);
9867 -- Extra underlying places to search, if not found above. For
9868 -- concurrent types, the relevant discriminant appears in the
9869 -- corresponding record. For a type derived from a private type
9870 -- without discriminant, the full view inherits the discriminants
9871 -- of the full view of the parent.
9873 if Result = Discriminant then
9874 if Is_Concurrent_Type (Ti)
9875 and then Present (Corresponding_Record_Type (Ti))
9878 Search_Derivation_Levels (
9879 Corresponding_Record_Type (Ti),
9881 Stored_Discrim_Values);
9883 elsif Is_Private_Type (Ti)
9884 and then not Has_Discriminants (Ti)
9885 and then Present (Full_View (Ti))
9886 and then Etype (Full_View (Ti)) /= Ti
9889 Search_Derivation_Levels (
9892 Stored_Discrim_Values);
9896 -- If Result is not a (reference to a) discriminant,
9897 -- return it, otherwise set Result_Entity to the discriminant.
9899 if Nkind (Result) = N_Defining_Identifier then
9901 pragma Assert (Result = Discriminant);
9903 Result_Entity := Result;
9906 if not Denotes_Discriminant (Result) then
9910 Result_Entity := Entity (Result);
9913 -- See if this level of derivation actually has discriminants
9914 -- because tagged derivations can add them, hence the lower
9915 -- levels need not have any.
9917 if not Has_Discriminants (Ti) then
9921 -- Scan Ti's discriminants for Result_Entity,
9922 -- and return its corresponding value, if any.
9924 Result_Entity := Original_Record_Component (Result_Entity);
9926 Assoc := First_Elmt (Discrim_Values);
9928 if Stored_Discrim_Values then
9929 Disc := First_Stored_Discriminant (Ti);
9931 Disc := First_Discriminant (Ti);
9934 while Present (Disc) loop
9936 pragma Assert (Present (Assoc));
9938 if Original_Record_Component (Disc) = Result_Entity then
9939 return Node (Assoc);
9944 if Stored_Discrim_Values then
9945 Next_Stored_Discriminant (Disc);
9947 Next_Discriminant (Disc);
9951 -- Could not find it
9954 end Search_Derivation_Levels;
9956 Result : Node_Or_Entity_Id;
9958 -- Start of processing for Get_Discriminant_Value
9961 -- ??? this routine is a gigantic mess and will be deleted.
9962 -- for the time being just test for the trivial case before calling
9965 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
9967 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9968 E : Elmt_Id := First_Elmt (Constraint);
9970 while Present (D) loop
9971 if Chars (D) = Chars (Discriminant) then
9975 Next_Discriminant (D);
9981 Result := Search_Derivation_Levels
9982 (Typ_For_Constraint, Constraint, False);
9984 -- ??? hack to disappear when this routine is gone
9986 if Nkind (Result) = N_Defining_Identifier then
9988 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9989 E : Elmt_Id := First_Elmt (Constraint);
9992 while Present (D) loop
9993 if Corresponding_Discriminant (D) = Discriminant then
9997 Next_Discriminant (D);
10003 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
10005 end Get_Discriminant_Value;
10007 --------------------------
10008 -- Has_Range_Constraint --
10009 --------------------------
10011 function Has_Range_Constraint (N : Node_Id) return Boolean is
10012 C : constant Node_Id := Constraint (N);
10015 if Nkind (C) = N_Range_Constraint then
10018 elsif Nkind (C) = N_Digits_Constraint then
10020 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
10022 Present (Range_Constraint (C));
10024 elsif Nkind (C) = N_Delta_Constraint then
10025 return Present (Range_Constraint (C));
10030 end Has_Range_Constraint;
10032 ------------------------
10033 -- Inherit_Components --
10034 ------------------------
10036 function Inherit_Components
10038 Parent_Base : Entity_Id;
10039 Derived_Base : Entity_Id;
10040 Is_Tagged : Boolean;
10041 Inherit_Discr : Boolean;
10042 Discs : Elist_Id) return Elist_Id
10044 Assoc_List : constant Elist_Id := New_Elmt_List;
10046 procedure Inherit_Component
10047 (Old_C : Entity_Id;
10048 Plain_Discrim : Boolean := False;
10049 Stored_Discrim : Boolean := False);
10050 -- Inherits component Old_C from Parent_Base to the Derived_Base.
10051 -- If Plain_Discrim is True, Old_C is a discriminant.
10052 -- If Stored_Discrim is True, Old_C is a stored discriminant.
10053 -- If they are both false then Old_C is a regular component.
10055 -----------------------
10056 -- Inherit_Component --
10057 -----------------------
10059 procedure Inherit_Component
10060 (Old_C : Entity_Id;
10061 Plain_Discrim : Boolean := False;
10062 Stored_Discrim : Boolean := False)
10064 New_C : constant Entity_Id := New_Copy (Old_C);
10066 Discrim : Entity_Id;
10067 Corr_Discrim : Entity_Id;
10070 pragma Assert (not Is_Tagged or else not Stored_Discrim);
10072 Set_Parent (New_C, Parent (Old_C));
10074 -- Regular discriminants and components must be inserted
10075 -- in the scope of the Derived_Base. Do it here.
10077 if not Stored_Discrim then
10078 Enter_Name (New_C);
10081 -- For tagged types the Original_Record_Component must point to
10082 -- whatever this field was pointing to in the parent type. This has
10083 -- already been achieved by the call to New_Copy above.
10085 if not Is_Tagged then
10086 Set_Original_Record_Component (New_C, New_C);
10089 -- If we have inherited a component then see if its Etype contains
10090 -- references to Parent_Base discriminants. In this case, replace
10091 -- these references with the constraints given in Discs. We do not
10092 -- do this for the partial view of private types because this is
10093 -- not needed (only the components of the full view will be used
10094 -- for code generation) and cause problem. We also avoid this
10095 -- transformation in some error situations.
10097 if Ekind (New_C) = E_Component then
10098 if (Is_Private_Type (Derived_Base)
10099 and then not Is_Generic_Type (Derived_Base))
10100 or else (Is_Empty_Elmt_List (Discs)
10101 and then not Expander_Active)
10103 Set_Etype (New_C, Etype (Old_C));
10105 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
10106 Derived_Base, N, Parent_Base, Discs));
10110 -- In derived tagged types it is illegal to reference a non
10111 -- discriminant component in the parent type. To catch this, mark
10112 -- these components with an Ekind of E_Void. This will be reset in
10113 -- Record_Type_Definition after processing the record extension of
10114 -- the derived type.
10116 if Is_Tagged and then Ekind (New_C) = E_Component then
10117 Set_Ekind (New_C, E_Void);
10120 if Plain_Discrim then
10121 Set_Corresponding_Discriminant (New_C, Old_C);
10122 Build_Discriminal (New_C);
10124 -- If we are explicitly inheriting a stored discriminant it will be
10125 -- completely hidden.
10127 elsif Stored_Discrim then
10128 Set_Corresponding_Discriminant (New_C, Empty);
10129 Set_Discriminal (New_C, Empty);
10130 Set_Is_Completely_Hidden (New_C);
10132 -- Set the Original_Record_Component of each discriminant in the
10133 -- derived base to point to the corresponding stored that we just
10136 Discrim := First_Discriminant (Derived_Base);
10137 while Present (Discrim) loop
10138 Corr_Discrim := Corresponding_Discriminant (Discrim);
10140 -- Corr_Discrimm could be missing in an error situation.
10142 if Present (Corr_Discrim)
10143 and then Original_Record_Component (Corr_Discrim) = Old_C
10145 Set_Original_Record_Component (Discrim, New_C);
10148 Next_Discriminant (Discrim);
10151 Append_Entity (New_C, Derived_Base);
10154 if not Is_Tagged then
10155 Append_Elmt (Old_C, Assoc_List);
10156 Append_Elmt (New_C, Assoc_List);
10158 end Inherit_Component;
10160 -- Variables local to Inherit_Components.
10162 Loc : constant Source_Ptr := Sloc (N);
10164 Parent_Discrim : Entity_Id;
10165 Stored_Discrim : Entity_Id;
10168 Component : Entity_Id;
10170 -- Start of processing for Inherit_Components
10173 if not Is_Tagged then
10174 Append_Elmt (Parent_Base, Assoc_List);
10175 Append_Elmt (Derived_Base, Assoc_List);
10178 -- Inherit parent discriminants if needed.
10180 if Inherit_Discr then
10181 Parent_Discrim := First_Discriminant (Parent_Base);
10182 while Present (Parent_Discrim) loop
10183 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
10184 Next_Discriminant (Parent_Discrim);
10188 -- Create explicit stored discrims for untagged types when necessary.
10190 if not Has_Unknown_Discriminants (Derived_Base)
10191 and then Has_Discriminants (Parent_Base)
10192 and then not Is_Tagged
10195 or else First_Discriminant (Parent_Base) /=
10196 First_Stored_Discriminant (Parent_Base))
10198 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
10199 while Present (Stored_Discrim) loop
10200 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
10201 Next_Stored_Discriminant (Stored_Discrim);
10205 -- See if we can apply the second transformation for derived types, as
10206 -- explained in point 6. in the comments above Build_Derived_Record_Type
10207 -- This is achieved by appending Derived_Base discriminants into
10208 -- Discs, which has the side effect of returning a non empty Discs
10209 -- list to the caller of Inherit_Components, which is what we want.
10212 and then Is_Empty_Elmt_List (Discs)
10213 and then (not Is_Private_Type (Derived_Base)
10214 or Is_Generic_Type (Derived_Base))
10216 D := First_Discriminant (Derived_Base);
10217 while Present (D) loop
10218 Append_Elmt (New_Reference_To (D, Loc), Discs);
10219 Next_Discriminant (D);
10223 -- Finally, inherit non-discriminant components unless they are not
10224 -- visible because defined or inherited from the full view of the
10225 -- parent. Don't inherit the _parent field of the parent type.
10227 Component := First_Entity (Parent_Base);
10228 while Present (Component) loop
10229 if Ekind (Component) /= E_Component
10230 or else Chars (Component) = Name_uParent
10234 -- If the derived type is within the parent type's declarative
10235 -- region, then the components can still be inherited even though
10236 -- they aren't visible at this point. This can occur for cases
10237 -- such as within public child units where the components must
10238 -- become visible upon entering the child unit's private part.
10240 elsif not Is_Visible_Component (Component)
10241 and then not In_Open_Scopes (Scope (Parent_Base))
10245 elsif Ekind (Derived_Base) = E_Private_Type
10246 or else Ekind (Derived_Base) = E_Limited_Private_Type
10251 Inherit_Component (Component);
10254 Next_Entity (Component);
10257 -- For tagged derived types, inherited discriminants cannot be used in
10258 -- component declarations of the record extension part. To achieve this
10259 -- we mark the inherited discriminants as not visible.
10261 if Is_Tagged and then Inherit_Discr then
10262 D := First_Discriminant (Derived_Base);
10263 while Present (D) loop
10264 Set_Is_Immediately_Visible (D, False);
10265 Next_Discriminant (D);
10270 end Inherit_Components;
10272 ------------------------------
10273 -- Is_Valid_Constraint_Kind --
10274 ------------------------------
10276 function Is_Valid_Constraint_Kind
10277 (T_Kind : Type_Kind;
10278 Constraint_Kind : Node_Kind) return Boolean
10283 when Enumeration_Kind |
10285 return Constraint_Kind = N_Range_Constraint;
10287 when Decimal_Fixed_Point_Kind =>
10289 Constraint_Kind = N_Digits_Constraint
10291 Constraint_Kind = N_Range_Constraint;
10293 when Ordinary_Fixed_Point_Kind =>
10295 Constraint_Kind = N_Delta_Constraint
10297 Constraint_Kind = N_Range_Constraint;
10301 Constraint_Kind = N_Digits_Constraint
10303 Constraint_Kind = N_Range_Constraint;
10310 E_Incomplete_Type |
10313 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
10316 return True; -- Error will be detected later.
10319 end Is_Valid_Constraint_Kind;
10321 --------------------------
10322 -- Is_Visible_Component --
10323 --------------------------
10325 function Is_Visible_Component (C : Entity_Id) return Boolean is
10326 Original_Comp : Entity_Id := Empty;
10327 Original_Scope : Entity_Id;
10328 Type_Scope : Entity_Id;
10330 function Is_Local_Type (Typ : Entity_Id) return Boolean;
10331 -- Check whether parent type of inherited component is declared
10332 -- locally, possibly within a nested package or instance. The
10333 -- current scope is the derived record itself.
10335 -------------------
10336 -- Is_Local_Type --
10337 -------------------
10339 function Is_Local_Type (Typ : Entity_Id) return Boolean is
10340 Scop : Entity_Id := Scope (Typ);
10343 while Present (Scop)
10344 and then Scop /= Standard_Standard
10346 if Scop = Scope (Current_Scope) then
10350 Scop := Scope (Scop);
10355 -- Start of processing for Is_Visible_Component
10358 if Ekind (C) = E_Component
10359 or else Ekind (C) = E_Discriminant
10361 Original_Comp := Original_Record_Component (C);
10364 if No (Original_Comp) then
10366 -- Premature usage, or previous error
10371 Original_Scope := Scope (Original_Comp);
10372 Type_Scope := Scope (Base_Type (Scope (C)));
10375 -- This test only concerns tagged types
10377 if not Is_Tagged_Type (Original_Scope) then
10380 -- If it is _Parent or _Tag, there is no visibility issue
10382 elsif not Comes_From_Source (Original_Comp) then
10385 -- If we are in the body of an instantiation, the component is
10386 -- visible even when the parent type (possibly defined in an
10387 -- enclosing unit or in a parent unit) might not.
10389 elsif In_Instance_Body then
10392 -- Discriminants are always visible.
10394 elsif Ekind (Original_Comp) = E_Discriminant
10395 and then not Has_Unknown_Discriminants (Original_Scope)
10399 -- If the component has been declared in an ancestor which is
10400 -- currently a private type, then it is not visible. The same
10401 -- applies if the component's containing type is not in an
10402 -- open scope and the original component's enclosing type
10403 -- is a visible full type of a private type (which can occur
10404 -- in cases where an attempt is being made to reference a
10405 -- component in a sibling package that is inherited from a
10406 -- visible component of a type in an ancestor package; the
10407 -- component in the sibling package should not be visible
10408 -- even though the component it inherited from is visible).
10409 -- This does not apply however in the case where the scope
10410 -- of the type is a private child unit, or when the parent
10411 -- comes from a local package in which the ancestor is
10412 -- currently visible. The latter suppression of visibility
10413 -- is needed for cases that are tested in B730006.
10415 elsif Is_Private_Type (Original_Scope)
10417 (not Is_Private_Descendant (Type_Scope)
10418 and then not In_Open_Scopes (Type_Scope)
10419 and then Has_Private_Declaration (Original_Scope))
10421 -- If the type derives from an entity in a formal package, there
10422 -- are no additional visible components.
10424 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
10425 N_Formal_Package_Declaration
10429 -- if we are not in the private part of the current package, there
10430 -- are no additional visible components.
10432 elsif Ekind (Scope (Current_Scope)) = E_Package
10433 and then not In_Private_Part (Scope (Current_Scope))
10438 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
10439 and then Is_Local_Type (Type_Scope);
10442 -- There is another weird way in which a component may be invisible
10443 -- when the private and the full view are not derived from the same
10444 -- ancestor. Here is an example :
10446 -- type A1 is tagged record F1 : integer; end record;
10447 -- type A2 is new A1 with record F2 : integer; end record;
10448 -- type T is new A1 with private;
10450 -- type T is new A2 with null record;
10452 -- In this case, the full view of T inherits F1 and F2 but the
10453 -- private view inherits only F1
10457 Ancestor : Entity_Id := Scope (C);
10461 if Ancestor = Original_Scope then
10463 elsif Ancestor = Etype (Ancestor) then
10467 Ancestor := Etype (Ancestor);
10473 end Is_Visible_Component;
10475 --------------------------
10476 -- Make_Class_Wide_Type --
10477 --------------------------
10479 procedure Make_Class_Wide_Type (T : Entity_Id) is
10480 CW_Type : Entity_Id;
10482 Next_E : Entity_Id;
10485 -- The class wide type can have been defined by the partial view in
10486 -- which case everything is already done
10488 if Present (Class_Wide_Type (T)) then
10493 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
10495 -- Inherit root type characteristics
10497 CW_Name := Chars (CW_Type);
10498 Next_E := Next_Entity (CW_Type);
10499 Copy_Node (T, CW_Type);
10500 Set_Comes_From_Source (CW_Type, False);
10501 Set_Chars (CW_Type, CW_Name);
10502 Set_Parent (CW_Type, Parent (T));
10503 Set_Next_Entity (CW_Type, Next_E);
10504 Set_Has_Delayed_Freeze (CW_Type);
10506 -- Customize the class-wide type: It has no prim. op., it cannot be
10507 -- abstract and its Etype points back to the specific root type.
10509 Set_Ekind (CW_Type, E_Class_Wide_Type);
10510 Set_Is_Tagged_Type (CW_Type, True);
10511 Set_Primitive_Operations (CW_Type, New_Elmt_List);
10512 Set_Is_Abstract (CW_Type, False);
10513 Set_Is_Constrained (CW_Type, False);
10514 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
10515 Init_Size_Align (CW_Type);
10517 if Ekind (T) = E_Class_Wide_Subtype then
10518 Set_Etype (CW_Type, Etype (Base_Type (T)));
10520 Set_Etype (CW_Type, T);
10523 -- If this is the class_wide type of a constrained subtype, it does
10524 -- not have discriminants.
10526 Set_Has_Discriminants (CW_Type,
10527 Has_Discriminants (T) and then not Is_Constrained (T));
10529 Set_Has_Unknown_Discriminants (CW_Type, True);
10530 Set_Class_Wide_Type (T, CW_Type);
10531 Set_Equivalent_Type (CW_Type, Empty);
10533 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
10535 Set_Class_Wide_Type (CW_Type, CW_Type);
10537 end Make_Class_Wide_Type;
10543 procedure Make_Index
10545 Related_Nod : Node_Id;
10546 Related_Id : Entity_Id := Empty;
10547 Suffix_Index : Nat := 1)
10551 Def_Id : Entity_Id := Empty;
10552 Found : Boolean := False;
10555 -- For a discrete range used in a constrained array definition and
10556 -- defined by a range, an implicit conversion to the predefined type
10557 -- INTEGER is assumed if each bound is either a numeric literal, a named
10558 -- number, or an attribute, and the type of both bounds (prior to the
10559 -- implicit conversion) is the type universal_integer. Otherwise, both
10560 -- bounds must be of the same discrete type, other than universal
10561 -- integer; this type must be determinable independently of the
10562 -- context, but using the fact that the type must be discrete and that
10563 -- both bounds must have the same type.
10565 -- Character literals also have a universal type in the absence of
10566 -- of additional context, and are resolved to Standard_Character.
10568 if Nkind (I) = N_Range then
10570 -- The index is given by a range constraint. The bounds are known
10571 -- to be of a consistent type.
10573 if not Is_Overloaded (I) then
10576 -- If the bounds are universal, choose the specific predefined
10579 if T = Universal_Integer then
10580 T := Standard_Integer;
10582 elsif T = Any_Character then
10586 ("ambiguous character literals (could be Wide_Character)",
10590 T := Standard_Character;
10597 Ind : Interp_Index;
10601 Get_First_Interp (I, Ind, It);
10603 while Present (It.Typ) loop
10604 if Is_Discrete_Type (It.Typ) then
10607 and then not Covers (It.Typ, T)
10608 and then not Covers (T, It.Typ)
10610 Error_Msg_N ("ambiguous bounds in discrete range", I);
10618 Get_Next_Interp (Ind, It);
10621 if T = Any_Type then
10622 Error_Msg_N ("discrete type required for range", I);
10623 Set_Etype (I, Any_Type);
10626 elsif T = Universal_Integer then
10627 T := Standard_Integer;
10632 if not Is_Discrete_Type (T) then
10633 Error_Msg_N ("discrete type required for range", I);
10634 Set_Etype (I, Any_Type);
10638 if Nkind (Low_Bound (I)) = N_Attribute_Reference
10639 and then Attribute_Name (Low_Bound (I)) = Name_First
10640 and then Is_Entity_Name (Prefix (Low_Bound (I)))
10641 and then Is_Type (Entity (Prefix (Low_Bound (I))))
10642 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I))))
10644 -- The type of the index will be the type of the prefix,
10645 -- as long as the upper bound is 'Last of the same type.
10647 Def_Id := Entity (Prefix (Low_Bound (I)));
10649 if Nkind (High_Bound (I)) /= N_Attribute_Reference
10650 or else Attribute_Name (High_Bound (I)) /= Name_Last
10651 or else not Is_Entity_Name (Prefix (High_Bound (I)))
10652 or else Entity (Prefix (High_Bound (I))) /= Def_Id
10659 Process_Range_Expr_In_Decl (R, T);
10661 elsif Nkind (I) = N_Subtype_Indication then
10663 -- The index is given by a subtype with a range constraint.
10665 T := Base_Type (Entity (Subtype_Mark (I)));
10667 if not Is_Discrete_Type (T) then
10668 Error_Msg_N ("discrete type required for range", I);
10669 Set_Etype (I, Any_Type);
10673 R := Range_Expression (Constraint (I));
10676 Process_Range_Expr_In_Decl (R, Entity (Subtype_Mark (I)));
10678 elsif Nkind (I) = N_Attribute_Reference then
10680 -- The parser guarantees that the attribute is a RANGE attribute
10682 -- If the node denotes the range of a type mark, that is also the
10683 -- resulting type, and we do no need to create an Itype for it.
10685 if Is_Entity_Name (Prefix (I))
10686 and then Comes_From_Source (I)
10687 and then Is_Type (Entity (Prefix (I)))
10688 and then Is_Discrete_Type (Entity (Prefix (I)))
10690 Def_Id := Entity (Prefix (I));
10693 Analyze_And_Resolve (I);
10697 -- If none of the above, must be a subtype. We convert this to a
10698 -- range attribute reference because in the case of declared first
10699 -- named subtypes, the types in the range reference can be different
10700 -- from the type of the entity. A range attribute normalizes the
10701 -- reference and obtains the correct types for the bounds.
10703 -- This transformation is in the nature of an expansion, is only
10704 -- done if expansion is active. In particular, it is not done on
10705 -- formal generic types, because we need to retain the name of the
10706 -- original index for instantiation purposes.
10709 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
10710 Error_Msg_N ("invalid subtype mark in discrete range ", I);
10711 Set_Etype (I, Any_Integer);
10714 -- The type mark may be that of an incomplete type. It is only
10715 -- now that we can get the full view, previous analysis does
10716 -- not look specifically for a type mark.
10718 Set_Entity (I, Get_Full_View (Entity (I)));
10719 Set_Etype (I, Entity (I));
10720 Def_Id := Entity (I);
10722 if not Is_Discrete_Type (Def_Id) then
10723 Error_Msg_N ("discrete type required for index", I);
10724 Set_Etype (I, Any_Type);
10729 if Expander_Active then
10731 Make_Attribute_Reference (Sloc (I),
10732 Attribute_Name => Name_Range,
10733 Prefix => Relocate_Node (I)));
10735 -- The original was a subtype mark that does not freeze. This
10736 -- means that the rewritten version must not freeze either.
10738 Set_Must_Not_Freeze (I);
10739 Set_Must_Not_Freeze (Prefix (I));
10741 -- Is order critical??? if so, document why, if not
10742 -- use Analyze_And_Resolve
10749 -- If expander is inactive, type is legal, nothing else to construct
10756 if not Is_Discrete_Type (T) then
10757 Error_Msg_N ("discrete type required for range", I);
10758 Set_Etype (I, Any_Type);
10761 elsif T = Any_Type then
10762 Set_Etype (I, Any_Type);
10766 -- We will now create the appropriate Itype to describe the
10767 -- range, but first a check. If we originally had a subtype,
10768 -- then we just label the range with this subtype. Not only
10769 -- is there no need to construct a new subtype, but it is wrong
10770 -- to do so for two reasons:
10772 -- 1. A legality concern, if we have a subtype, it must not
10773 -- freeze, and the Itype would cause freezing incorrectly
10775 -- 2. An efficiency concern, if we created an Itype, it would
10776 -- not be recognized as the same type for the purposes of
10777 -- eliminating checks in some circumstances.
10779 -- We signal this case by setting the subtype entity in Def_Id.
10781 if No (Def_Id) then
10784 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
10785 Set_Etype (Def_Id, Base_Type (T));
10787 if Is_Signed_Integer_Type (T) then
10788 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
10790 elsif Is_Modular_Integer_Type (T) then
10791 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
10794 Set_Ekind (Def_Id, E_Enumeration_Subtype);
10795 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
10796 Set_First_Literal (Def_Id, First_Literal (T));
10799 Set_Size_Info (Def_Id, (T));
10800 Set_RM_Size (Def_Id, RM_Size (T));
10801 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10803 Set_Scalar_Range (Def_Id, R);
10804 Conditional_Delay (Def_Id, T);
10806 -- In the subtype indication case, if the immediate parent of the
10807 -- new subtype is non-static, then the subtype we create is non-
10808 -- static, even if its bounds are static.
10810 if Nkind (I) = N_Subtype_Indication
10811 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
10813 Set_Is_Non_Static_Subtype (Def_Id);
10817 -- Final step is to label the index with this constructed type
10819 Set_Etype (I, Def_Id);
10822 ------------------------------
10823 -- Modular_Type_Declaration --
10824 ------------------------------
10826 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10827 Mod_Expr : constant Node_Id := Expression (Def);
10830 procedure Set_Modular_Size (Bits : Int);
10831 -- Sets RM_Size to Bits, and Esize to normal word size above this
10833 ----------------------
10834 -- Set_Modular_Size --
10835 ----------------------
10837 procedure Set_Modular_Size (Bits : Int) is
10839 Set_RM_Size (T, UI_From_Int (Bits));
10844 elsif Bits <= 16 then
10845 Init_Esize (T, 16);
10847 elsif Bits <= 32 then
10848 Init_Esize (T, 32);
10851 Init_Esize (T, System_Max_Binary_Modulus_Power);
10853 end Set_Modular_Size;
10855 -- Start of processing for Modular_Type_Declaration
10858 Analyze_And_Resolve (Mod_Expr, Any_Integer);
10860 Set_Ekind (T, E_Modular_Integer_Type);
10861 Init_Alignment (T);
10862 Set_Is_Constrained (T);
10864 if not Is_OK_Static_Expression (Mod_Expr) then
10865 Flag_Non_Static_Expr
10866 ("non-static expression used for modular type bound!", Mod_Expr);
10867 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10869 M_Val := Expr_Value (Mod_Expr);
10873 Error_Msg_N ("modulus value must be positive", Mod_Expr);
10874 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10877 Set_Modulus (T, M_Val);
10879 -- Create bounds for the modular type based on the modulus given in
10880 -- the type declaration and then analyze and resolve those bounds.
10882 Set_Scalar_Range (T,
10883 Make_Range (Sloc (Mod_Expr),
10885 Make_Integer_Literal (Sloc (Mod_Expr), 0),
10887 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
10889 -- Properly analyze the literals for the range. We do this manually
10890 -- because we can't go calling Resolve, since we are resolving these
10891 -- bounds with the type, and this type is certainly not complete yet!
10893 Set_Etype (Low_Bound (Scalar_Range (T)), T);
10894 Set_Etype (High_Bound (Scalar_Range (T)), T);
10895 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
10896 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
10898 -- Loop through powers of two to find number of bits required
10900 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
10904 if M_Val = 2 ** Bits then
10905 Set_Modular_Size (Bits);
10910 elsif M_Val < 2 ** Bits then
10911 Set_Non_Binary_Modulus (T);
10913 if Bits > System_Max_Nonbinary_Modulus_Power then
10914 Error_Msg_Uint_1 :=
10915 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
10917 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
10918 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10922 -- In the non-binary case, set size as per RM 13.3(55).
10924 Set_Modular_Size (Bits);
10931 -- If we fall through, then the size exceed System.Max_Binary_Modulus
10932 -- so we just signal an error and set the maximum size.
10934 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
10935 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
10937 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10938 Init_Alignment (T);
10940 end Modular_Type_Declaration;
10942 -------------------------
10943 -- New_Binary_Operator --
10944 -------------------------
10946 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id) is
10947 Loc : constant Source_Ptr := Sloc (Typ);
10950 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
10951 -- Create abbreviated declaration for the formal of a predefined
10952 -- Operator 'Op' of type 'Typ'
10954 --------------------
10955 -- Make_Op_Formal --
10956 --------------------
10958 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
10959 Formal : Entity_Id;
10962 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
10963 Set_Etype (Formal, Typ);
10964 Set_Mechanism (Formal, Default_Mechanism);
10966 end Make_Op_Formal;
10968 -- Start of processing for New_Binary_Operator
10971 Op := Make_Defining_Operator_Symbol (Loc, Op_Name);
10973 Set_Ekind (Op, E_Operator);
10974 Set_Scope (Op, Current_Scope);
10975 Set_Etype (Op, Typ);
10976 Set_Homonym (Op, Get_Name_Entity_Id (Op_Name));
10977 Set_Is_Immediately_Visible (Op);
10978 Set_Is_Intrinsic_Subprogram (Op);
10979 Set_Has_Completion (Op);
10980 Append_Entity (Op, Current_Scope);
10982 Set_Name_Entity_Id (Op_Name, Op);
10984 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10985 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10987 end New_Binary_Operator;
10989 -------------------------------------------
10990 -- Ordinary_Fixed_Point_Type_Declaration --
10991 -------------------------------------------
10993 procedure Ordinary_Fixed_Point_Type_Declaration
10997 Loc : constant Source_Ptr := Sloc (Def);
10998 Delta_Expr : constant Node_Id := Delta_Expression (Def);
10999 RRS : constant Node_Id := Real_Range_Specification (Def);
11000 Implicit_Base : Entity_Id;
11007 Check_Restriction (No_Fixed_Point, Def);
11009 -- Create implicit base type
11012 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
11013 Set_Etype (Implicit_Base, Implicit_Base);
11015 -- Analyze and process delta expression
11017 Analyze_And_Resolve (Delta_Expr, Any_Real);
11019 Check_Delta_Expression (Delta_Expr);
11020 Delta_Val := Expr_Value_R (Delta_Expr);
11022 Set_Delta_Value (Implicit_Base, Delta_Val);
11024 -- Compute default small from given delta, which is the largest
11025 -- power of two that does not exceed the given delta value.
11028 Tmp : Ureal := Ureal_1;
11032 if Delta_Val < Ureal_1 then
11033 while Delta_Val < Tmp loop
11034 Tmp := Tmp / Ureal_2;
11035 Scale := Scale + 1;
11040 Tmp := Tmp * Ureal_2;
11041 exit when Tmp > Delta_Val;
11042 Scale := Scale - 1;
11046 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
11049 Set_Small_Value (Implicit_Base, Small_Val);
11051 -- If no range was given, set a dummy range
11053 if RRS <= Empty_Or_Error then
11054 Low_Val := -Small_Val;
11055 High_Val := Small_Val;
11057 -- Otherwise analyze and process given range
11061 Low : constant Node_Id := Low_Bound (RRS);
11062 High : constant Node_Id := High_Bound (RRS);
11065 Analyze_And_Resolve (Low, Any_Real);
11066 Analyze_And_Resolve (High, Any_Real);
11067 Check_Real_Bound (Low);
11068 Check_Real_Bound (High);
11070 -- Obtain and set the range
11072 Low_Val := Expr_Value_R (Low);
11073 High_Val := Expr_Value_R (High);
11075 if Low_Val > High_Val then
11076 Error_Msg_NE ("?fixed point type& has null range", Def, T);
11081 -- The range for both the implicit base and the declared first
11082 -- subtype cannot be set yet, so we use the special routine
11083 -- Set_Fixed_Range to set a temporary range in place. Note that
11084 -- the bounds of the base type will be widened to be symmetrical
11085 -- and to fill the available bits when the type is frozen.
11087 -- We could do this with all discrete types, and probably should, but
11088 -- we absolutely have to do it for fixed-point, since the end-points
11089 -- of the range and the size are determined by the small value, which
11090 -- could be reset before the freeze point.
11092 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
11093 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
11095 Init_Size_Align (Implicit_Base);
11097 -- Complete definition of first subtype
11099 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
11100 Set_Etype (T, Implicit_Base);
11101 Init_Size_Align (T);
11102 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
11103 Set_Small_Value (T, Small_Val);
11104 Set_Delta_Value (T, Delta_Val);
11105 Set_Is_Constrained (T);
11107 end Ordinary_Fixed_Point_Type_Declaration;
11109 ----------------------------------------
11110 -- Prepare_Private_Subtype_Completion --
11111 ----------------------------------------
11113 procedure Prepare_Private_Subtype_Completion
11115 Related_Nod : Node_Id)
11117 Id_B : constant Entity_Id := Base_Type (Id);
11118 Full_B : constant Entity_Id := Full_View (Id_B);
11122 if Present (Full_B) then
11124 -- The Base_Type is already completed, we can complete the
11125 -- subtype now. We have to create a new entity with the same name,
11126 -- Thus we can't use Create_Itype.
11127 -- This is messy, should be fixed ???
11129 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
11130 Set_Is_Itype (Full);
11131 Set_Associated_Node_For_Itype (Full, Related_Nod);
11132 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
11135 -- The parent subtype may be private, but the base might not, in some
11136 -- nested instances. In that case, the subtype does not need to be
11137 -- exchanged. It would still be nice to make private subtypes and their
11138 -- bases consistent at all times ???
11140 if Is_Private_Type (Id_B) then
11141 Append_Elmt (Id, Private_Dependents (Id_B));
11144 end Prepare_Private_Subtype_Completion;
11146 ---------------------------
11147 -- Process_Discriminants --
11148 ---------------------------
11150 procedure Process_Discriminants
11152 Prev : Entity_Id := Empty)
11154 Elist : constant Elist_Id := New_Elmt_List;
11157 Discr_Number : Uint;
11158 Discr_Type : Entity_Id;
11159 Default_Present : Boolean := False;
11160 Default_Not_Present : Boolean := False;
11163 -- A composite type other than an array type can have discriminants.
11164 -- Discriminants of non-limited types must have a discrete type.
11165 -- On entry, the current scope is the composite type.
11167 -- The discriminants are initially entered into the scope of the type
11168 -- via Enter_Name with the default Ekind of E_Void to prevent premature
11169 -- use, as explained at the end of this procedure.
11171 Discr := First (Discriminant_Specifications (N));
11172 while Present (Discr) loop
11173 Enter_Name (Defining_Identifier (Discr));
11175 -- For navigation purposes we add a reference to the discriminant
11176 -- in the entity for the type. If the current declaration is a
11177 -- completion, place references on the partial view. Otherwise the
11178 -- type is the current scope.
11180 if Present (Prev) then
11182 -- The references go on the partial view, if present. If the
11183 -- partial view has discriminants, the references have been
11184 -- generated already.
11186 if not Has_Discriminants (Prev) then
11187 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
11191 (Current_Scope, Defining_Identifier (Discr), 'd');
11194 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
11195 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
11198 Find_Type (Discriminant_Type (Discr));
11199 Discr_Type := Etype (Discriminant_Type (Discr));
11201 if Error_Posted (Discriminant_Type (Discr)) then
11202 Discr_Type := Any_Type;
11206 if Is_Access_Type (Discr_Type) then
11207 Check_Access_Discriminant_Requires_Limited
11208 (Discr, Discriminant_Type (Discr));
11210 if Ada_83 and then Comes_From_Source (Discr) then
11212 ("(Ada 83) access discriminant not allowed", Discr);
11215 elsif not Is_Discrete_Type (Discr_Type) then
11216 Error_Msg_N ("discriminants must have a discrete or access type",
11217 Discriminant_Type (Discr));
11220 Set_Etype (Defining_Identifier (Discr), Discr_Type);
11222 -- If a discriminant specification includes the assignment compound
11223 -- delimiter followed by an expression, the expression is the default
11224 -- expression of the discriminant; the default expression must be of
11225 -- the type of the discriminant. (RM 3.7.1) Since this expression is
11226 -- a default expression, we do the special preanalysis, since this
11227 -- expression does not freeze (see "Handling of Default and Per-
11228 -- Object Expressions" in spec of package Sem).
11230 if Present (Expression (Discr)) then
11231 Analyze_Per_Use_Expression (Expression (Discr), Discr_Type);
11233 if Nkind (N) = N_Formal_Type_Declaration then
11235 ("discriminant defaults not allowed for formal type",
11236 Expression (Discr));
11238 elsif Is_Tagged_Type (Current_Scope) then
11240 ("discriminants of tagged type cannot have defaults",
11241 Expression (Discr));
11244 Default_Present := True;
11245 Append_Elmt (Expression (Discr), Elist);
11247 -- Tag the defining identifiers for the discriminants with
11248 -- their corresponding default expressions from the tree.
11250 Set_Discriminant_Default_Value
11251 (Defining_Identifier (Discr), Expression (Discr));
11255 Default_Not_Present := True;
11261 -- An element list consisting of the default expressions of the
11262 -- discriminants is constructed in the above loop and used to set
11263 -- the Discriminant_Constraint attribute for the type. If an object
11264 -- is declared of this (record or task) type without any explicit
11265 -- discriminant constraint given, this element list will form the
11266 -- actual parameters for the corresponding initialization procedure
11269 Set_Discriminant_Constraint (Current_Scope, Elist);
11270 Set_Stored_Constraint (Current_Scope, No_Elist);
11272 -- Default expressions must be provided either for all or for none
11273 -- of the discriminants of a discriminant part. (RM 3.7.1)
11275 if Default_Present and then Default_Not_Present then
11277 ("incomplete specification of defaults for discriminants", N);
11280 -- The use of the name of a discriminant is not allowed in default
11281 -- expressions of a discriminant part if the specification of the
11282 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
11284 -- To detect this, the discriminant names are entered initially with an
11285 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
11286 -- attempt to use a void entity (for example in an expression that is
11287 -- type-checked) produces the error message: premature usage. Now after
11288 -- completing the semantic analysis of the discriminant part, we can set
11289 -- the Ekind of all the discriminants appropriately.
11291 Discr := First (Discriminant_Specifications (N));
11292 Discr_Number := Uint_1;
11294 while Present (Discr) loop
11295 Id := Defining_Identifier (Discr);
11296 Set_Ekind (Id, E_Discriminant);
11297 Init_Component_Location (Id);
11299 Set_Discriminant_Number (Id, Discr_Number);
11301 -- Make sure this is always set, even in illegal programs
11303 Set_Corresponding_Discriminant (Id, Empty);
11305 -- Initialize the Original_Record_Component to the entity itself.
11306 -- Inherit_Components will propagate the right value to
11307 -- discriminants in derived record types.
11309 Set_Original_Record_Component (Id, Id);
11311 -- Create the discriminal for the discriminant.
11313 Build_Discriminal (Id);
11316 Discr_Number := Discr_Number + 1;
11319 Set_Has_Discriminants (Current_Scope);
11320 end Process_Discriminants;
11322 -----------------------
11323 -- Process_Full_View --
11324 -----------------------
11326 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
11327 Priv_Parent : Entity_Id;
11328 Full_Parent : Entity_Id;
11329 Full_Indic : Node_Id;
11332 -- First some sanity checks that must be done after semantic
11333 -- decoration of the full view and thus cannot be placed with other
11334 -- similar checks in Find_Type_Name
11336 if not Is_Limited_Type (Priv_T)
11337 and then (Is_Limited_Type (Full_T)
11338 or else Is_Limited_Composite (Full_T))
11341 ("completion of nonlimited type cannot be limited", Full_T);
11342 Explain_Limited_Type (Full_T, Full_T);
11344 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
11346 ("completion of nonabstract type cannot be abstract", Full_T);
11348 elsif Is_Tagged_Type (Priv_T)
11349 and then Is_Limited_Type (Priv_T)
11350 and then not Is_Limited_Type (Full_T)
11352 -- GNAT allow its own definition of Limited_Controlled to disobey
11353 -- this rule in order in ease the implementation. The next test is
11354 -- safe because Root_Controlled is defined in a private system child
11356 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
11357 Set_Is_Limited_Composite (Full_T);
11360 ("completion of limited tagged type must be limited", Full_T);
11363 elsif Is_Generic_Type (Priv_T) then
11364 Error_Msg_N ("generic type cannot have a completion", Full_T);
11367 if Is_Tagged_Type (Priv_T)
11368 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
11369 and then Is_Derived_Type (Full_T)
11371 Priv_Parent := Etype (Priv_T);
11373 -- The full view of a private extension may have been transformed
11374 -- into an unconstrained derived type declaration and a subtype
11375 -- declaration (see build_derived_record_type for details).
11377 if Nkind (N) = N_Subtype_Declaration then
11378 Full_Indic := Subtype_Indication (N);
11379 Full_Parent := Etype (Base_Type (Full_T));
11381 Full_Indic := Subtype_Indication (Type_Definition (N));
11382 Full_Parent := Etype (Full_T);
11385 -- Check that the parent type of the full type is a descendant of
11386 -- the ancestor subtype given in the private extension. If either
11387 -- entity has an Etype equal to Any_Type then we had some previous
11388 -- error situation [7.3(8)].
11390 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
11393 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
11395 ("parent of full type must descend from parent"
11396 & " of private extension", Full_Indic);
11398 -- Check the rules of 7.3(10): if the private extension inherits
11399 -- known discriminants, then the full type must also inherit those
11400 -- discriminants from the same (ancestor) type, and the parent
11401 -- subtype of the full type must be constrained if and only if
11402 -- the ancestor subtype of the private extension is constrained.
11404 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
11405 and then not Has_Unknown_Discriminants (Priv_T)
11406 and then Has_Discriminants (Base_Type (Priv_Parent))
11409 Priv_Indic : constant Node_Id :=
11410 Subtype_Indication (Parent (Priv_T));
11412 Priv_Constr : constant Boolean :=
11413 Is_Constrained (Priv_Parent)
11415 Nkind (Priv_Indic) = N_Subtype_Indication
11416 or else Is_Constrained (Entity (Priv_Indic));
11418 Full_Constr : constant Boolean :=
11419 Is_Constrained (Full_Parent)
11421 Nkind (Full_Indic) = N_Subtype_Indication
11422 or else Is_Constrained (Entity (Full_Indic));
11424 Priv_Discr : Entity_Id;
11425 Full_Discr : Entity_Id;
11428 Priv_Discr := First_Discriminant (Priv_Parent);
11429 Full_Discr := First_Discriminant (Full_Parent);
11431 while Present (Priv_Discr) and then Present (Full_Discr) loop
11432 if Original_Record_Component (Priv_Discr) =
11433 Original_Record_Component (Full_Discr)
11435 Corresponding_Discriminant (Priv_Discr) =
11436 Corresponding_Discriminant (Full_Discr)
11443 Next_Discriminant (Priv_Discr);
11444 Next_Discriminant (Full_Discr);
11447 if Present (Priv_Discr) or else Present (Full_Discr) then
11449 ("full view must inherit discriminants of the parent type"
11450 & " used in the private extension", Full_Indic);
11452 elsif Priv_Constr and then not Full_Constr then
11454 ("parent subtype of full type must be constrained",
11457 elsif Full_Constr and then not Priv_Constr then
11459 ("parent subtype of full type must be unconstrained",
11464 -- Check the rules of 7.3(12): if a partial view has neither known
11465 -- or unknown discriminants, then the full type declaration shall
11466 -- define a definite subtype.
11468 elsif not Has_Unknown_Discriminants (Priv_T)
11469 and then not Has_Discriminants (Priv_T)
11470 and then not Is_Constrained (Full_T)
11473 ("full view must define a constrained type if partial view"
11474 & " has no discriminants", Full_T);
11477 -- ??????? Do we implement the following properly ?????
11478 -- If the ancestor subtype of a private extension has constrained
11479 -- discriminants, then the parent subtype of the full view shall
11480 -- impose a statically matching constraint on those discriminants
11484 -- For untagged types, verify that a type without discriminants
11485 -- is not completed with an unconstrained type.
11487 if not Is_Indefinite_Subtype (Priv_T)
11488 and then Is_Indefinite_Subtype (Full_T)
11490 Error_Msg_N ("full view of type must be definite subtype", Full_T);
11494 -- Create a full declaration for all its subtypes recorded in
11495 -- Private_Dependents and swap them similarly to the base type.
11496 -- These are subtypes that have been define before the full
11497 -- declaration of the private type. We also swap the entry in
11498 -- Private_Dependents list so we can properly restore the
11499 -- private view on exit from the scope.
11502 Priv_Elmt : Elmt_Id;
11507 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
11508 while Present (Priv_Elmt) loop
11509 Priv := Node (Priv_Elmt);
11511 if Ekind (Priv) = E_Private_Subtype
11512 or else Ekind (Priv) = E_Limited_Private_Subtype
11513 or else Ekind (Priv) = E_Record_Subtype_With_Private
11515 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
11516 Set_Is_Itype (Full);
11517 Set_Parent (Full, Parent (Priv));
11518 Set_Associated_Node_For_Itype (Full, N);
11520 -- Now we need to complete the private subtype, but since the
11521 -- base type has already been swapped, we must also swap the
11522 -- subtypes (and thus, reverse the arguments in the call to
11523 -- Complete_Private_Subtype).
11525 Copy_And_Swap (Priv, Full);
11526 Complete_Private_Subtype (Full, Priv, Full_T, N);
11527 Replace_Elmt (Priv_Elmt, Full);
11530 Next_Elmt (Priv_Elmt);
11534 -- If the private view was tagged, copy the new Primitive
11535 -- operations from the private view to the full view.
11537 if Is_Tagged_Type (Full_T) then
11539 Priv_List : Elist_Id;
11540 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
11543 D_Type : Entity_Id;
11546 if Is_Tagged_Type (Priv_T) then
11547 Priv_List := Primitive_Operations (Priv_T);
11549 P1 := First_Elmt (Priv_List);
11550 while Present (P1) loop
11553 -- Transfer explicit primitives, not those inherited from
11554 -- parent of partial view, which will be re-inherited on
11557 if Comes_From_Source (Prim) then
11558 P2 := First_Elmt (Full_List);
11559 while Present (P2) and then Node (P2) /= Prim loop
11563 -- If not found, that is a new one
11566 Append_Elmt (Prim, Full_List);
11574 -- In this case the partial view is untagged, so here we
11575 -- locate all of the earlier primitives that need to be
11576 -- treated as dispatching (those that appear between the
11577 -- two views). Note that these additional operations must
11578 -- all be new operations (any earlier operations that
11579 -- override inherited operations of the full view will
11580 -- already have been inserted in the primitives list and
11581 -- marked as dispatching by Check_Operation_From_Private_View.
11582 -- Note that implicit "/=" operators are excluded from being
11583 -- added to the primitives list since they shouldn't be
11584 -- treated as dispatching (tagged "/=" is handled specially).
11586 Prim := Next_Entity (Full_T);
11587 while Present (Prim) and then Prim /= Priv_T loop
11588 if Ekind (Prim) = E_Procedure
11590 Ekind (Prim) = E_Function
11593 D_Type := Find_Dispatching_Type (Prim);
11596 and then (Chars (Prim) /= Name_Op_Ne
11597 or else Comes_From_Source (Prim))
11599 Check_Controlling_Formals (Full_T, Prim);
11601 if not Is_Dispatching_Operation (Prim) then
11602 Append_Elmt (Prim, Full_List);
11603 Set_Is_Dispatching_Operation (Prim, True);
11604 Set_DT_Position (Prim, No_Uint);
11607 elsif Is_Dispatching_Operation (Prim)
11608 and then D_Type /= Full_T
11611 -- Verify that it is not otherwise controlled by
11612 -- a formal or a return value ot type T.
11614 Check_Controlling_Formals (D_Type, Prim);
11618 Next_Entity (Prim);
11622 -- For the tagged case, the two views can share the same
11623 -- Primitive Operation list and the same class wide type.
11624 -- Update attributes of the class-wide type which depend on
11625 -- the full declaration.
11627 if Is_Tagged_Type (Priv_T) then
11628 Set_Primitive_Operations (Priv_T, Full_List);
11629 Set_Class_Wide_Type
11630 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
11632 -- Any other attributes should be propagated to C_W ???
11634 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
11639 end Process_Full_View;
11641 -----------------------------------
11642 -- Process_Incomplete_Dependents --
11643 -----------------------------------
11645 procedure Process_Incomplete_Dependents
11647 Full_T : Entity_Id;
11650 Inc_Elmt : Elmt_Id;
11651 Priv_Dep : Entity_Id;
11652 New_Subt : Entity_Id;
11654 Disc_Constraint : Elist_Id;
11657 if No (Private_Dependents (Inc_T)) then
11661 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
11663 -- Itypes that may be generated by the completion of an incomplete
11664 -- subtype are not used by the back-end and not attached to the tree.
11665 -- They are created only for constraint-checking purposes.
11668 while Present (Inc_Elmt) loop
11669 Priv_Dep := Node (Inc_Elmt);
11671 if Ekind (Priv_Dep) = E_Subprogram_Type then
11673 -- An Access_To_Subprogram type may have a return type or a
11674 -- parameter type that is incomplete. Replace with the full view.
11676 if Etype (Priv_Dep) = Inc_T then
11677 Set_Etype (Priv_Dep, Full_T);
11681 Formal : Entity_Id;
11684 Formal := First_Formal (Priv_Dep);
11686 while Present (Formal) loop
11688 if Etype (Formal) = Inc_T then
11689 Set_Etype (Formal, Full_T);
11692 Next_Formal (Formal);
11696 elsif Is_Overloadable (Priv_Dep) then
11698 if Is_Tagged_Type (Full_T) then
11700 -- Subprogram has an access parameter whose designated type
11701 -- was incomplete. Reexamine declaration now, because it may
11702 -- be a primitive operation of the full type.
11704 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
11705 Set_Is_Dispatching_Operation (Priv_Dep);
11706 Check_Controlling_Formals (Full_T, Priv_Dep);
11709 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
11711 -- Can happen during processing of a body before the completion
11712 -- of a TA type. Ignore, because spec is also on dependent list.
11716 -- Dependent is a subtype
11719 -- We build a new subtype indication using the full view of the
11720 -- incomplete parent. The discriminant constraints have been
11721 -- elaborated already at the point of the subtype declaration.
11723 New_Subt := Create_Itype (E_Void, N);
11725 if Has_Discriminants (Full_T) then
11726 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
11728 Disc_Constraint := No_Elist;
11731 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
11732 Set_Full_View (Priv_Dep, New_Subt);
11735 Next_Elmt (Inc_Elmt);
11738 end Process_Incomplete_Dependents;
11740 --------------------------------
11741 -- Process_Range_Expr_In_Decl --
11742 --------------------------------
11744 procedure Process_Range_Expr_In_Decl
11747 Check_List : List_Id := Empty_List;
11748 R_Check_Off : Boolean := False)
11751 R_Checks : Check_Result;
11752 Type_Decl : Node_Id;
11753 Def_Id : Entity_Id;
11756 Analyze_And_Resolve (R, Base_Type (T));
11758 if Nkind (R) = N_Range then
11759 Lo := Low_Bound (R);
11760 Hi := High_Bound (R);
11762 -- If there were errors in the declaration, try and patch up some
11763 -- common mistakes in the bounds. The cases handled are literals
11764 -- which are Integer where the expected type is Real and vice versa.
11765 -- These corrections allow the compilation process to proceed further
11766 -- along since some basic assumptions of the format of the bounds
11769 if Etype (R) = Any_Type then
11771 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
11773 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
11775 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
11777 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
11779 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
11781 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
11783 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
11785 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
11792 -- If the bounds of the range have been mistakenly given as
11793 -- string literals (perhaps in place of character literals),
11794 -- then an error has already been reported, but we rewrite
11795 -- the string literal as a bound of the range's type to
11796 -- avoid blowups in later processing that looks at static
11799 if Nkind (Lo) = N_String_Literal then
11801 Make_Attribute_Reference (Sloc (Lo),
11802 Attribute_Name => Name_First,
11803 Prefix => New_Reference_To (T, Sloc (Lo))));
11804 Analyze_And_Resolve (Lo);
11807 if Nkind (Hi) = N_String_Literal then
11809 Make_Attribute_Reference (Sloc (Hi),
11810 Attribute_Name => Name_First,
11811 Prefix => New_Reference_To (T, Sloc (Hi))));
11812 Analyze_And_Resolve (Hi);
11815 -- If bounds aren't scalar at this point then exit, avoiding
11816 -- problems with further processing of the range in this procedure.
11818 if not Is_Scalar_Type (Etype (Lo)) then
11822 -- Resolve (actually Sem_Eval) has checked that the bounds are in
11823 -- then range of the base type. Here we check whether the bounds
11824 -- are in the range of the subtype itself. Note that if the bounds
11825 -- represent the null range the Constraint_Error exception should
11828 -- ??? The following code should be cleaned up as follows
11829 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
11830 -- is done in the call to Range_Check (R, T); below
11831 -- 2. The use of R_Check_Off should be investigated and possibly
11832 -- removed, this would clean up things a bit.
11834 if Is_Null_Range (Lo, Hi) then
11838 -- Capture values of bounds and generate temporaries for them
11839 -- if needed, before applying checks, since checks may cause
11840 -- duplication of the expression without forcing evaluation.
11842 if Expander_Active then
11843 Force_Evaluation (Lo);
11844 Force_Evaluation (Hi);
11847 -- We use a flag here instead of suppressing checks on the
11848 -- type because the type we check against isn't necessarily
11849 -- the place where we put the check.
11851 if not R_Check_Off then
11852 R_Checks := Range_Check (R, T);
11853 Type_Decl := Parent (R);
11855 -- Look up tree to find an appropriate insertion point.
11856 -- This seems really junk code, and very brittle, couldn't
11857 -- we just use an insert actions call of some kind ???
11859 while Present (Type_Decl) and then not
11860 (Nkind (Type_Decl) = N_Full_Type_Declaration
11862 Nkind (Type_Decl) = N_Subtype_Declaration
11864 Nkind (Type_Decl) = N_Loop_Statement
11866 Nkind (Type_Decl) = N_Task_Type_Declaration
11868 Nkind (Type_Decl) = N_Single_Task_Declaration
11870 Nkind (Type_Decl) = N_Protected_Type_Declaration
11872 Nkind (Type_Decl) = N_Single_Protected_Declaration)
11874 Type_Decl := Parent (Type_Decl);
11877 -- Why would Type_Decl not be present??? Without this test,
11878 -- short regression tests fail.
11880 if Present (Type_Decl) then
11882 -- Case of loop statement (more comments ???)
11884 if Nkind (Type_Decl) = N_Loop_Statement then
11886 Indic : Node_Id := Parent (R);
11889 while Present (Indic) and then not
11890 (Nkind (Indic) = N_Subtype_Indication)
11892 Indic := Parent (Indic);
11895 if Present (Indic) then
11896 Def_Id := Etype (Subtype_Mark (Indic));
11898 Insert_Range_Checks
11904 Do_Before => True);
11908 -- All other cases (more comments ???)
11911 Def_Id := Defining_Identifier (Type_Decl);
11913 if (Ekind (Def_Id) = E_Record_Type
11914 and then Depends_On_Discriminant (R))
11916 (Ekind (Def_Id) = E_Protected_Type
11917 and then Has_Discriminants (Def_Id))
11919 Append_Range_Checks
11920 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
11923 Insert_Range_Checks
11924 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
11932 elsif Expander_Active then
11933 Get_Index_Bounds (R, Lo, Hi);
11934 Force_Evaluation (Lo);
11935 Force_Evaluation (Hi);
11937 end Process_Range_Expr_In_Decl;
11939 --------------------------------------
11940 -- Process_Real_Range_Specification --
11941 --------------------------------------
11943 procedure Process_Real_Range_Specification (Def : Node_Id) is
11944 Spec : constant Node_Id := Real_Range_Specification (Def);
11947 Err : Boolean := False;
11949 procedure Analyze_Bound (N : Node_Id);
11950 -- Analyze and check one bound
11952 -------------------
11953 -- Analyze_Bound --
11954 -------------------
11956 procedure Analyze_Bound (N : Node_Id) is
11958 Analyze_And_Resolve (N, Any_Real);
11960 if not Is_OK_Static_Expression (N) then
11961 Flag_Non_Static_Expr
11962 ("bound in real type definition is not static!", N);
11967 -- Start of processing for Process_Real_Range_Specification
11970 if Present (Spec) then
11971 Lo := Low_Bound (Spec);
11972 Hi := High_Bound (Spec);
11973 Analyze_Bound (Lo);
11974 Analyze_Bound (Hi);
11976 -- If error, clear away junk range specification
11979 Set_Real_Range_Specification (Def, Empty);
11982 end Process_Real_Range_Specification;
11984 ---------------------
11985 -- Process_Subtype --
11986 ---------------------
11988 function Process_Subtype
11990 Related_Nod : Node_Id;
11991 Related_Id : Entity_Id := Empty;
11992 Suffix : Character := ' ') return Entity_Id
11995 Def_Id : Entity_Id;
11996 Full_View_Id : Entity_Id;
11997 Subtype_Mark_Id : Entity_Id;
11999 procedure Check_Incomplete (T : Entity_Id);
12000 -- Called to verify that an incomplete type is not used prematurely
12002 ----------------------
12003 -- Check_Incomplete --
12004 ----------------------
12006 procedure Check_Incomplete (T : Entity_Id) is
12008 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
12009 Error_Msg_N ("invalid use of type before its full declaration", T);
12011 end Check_Incomplete;
12013 -- Start of processing for Process_Subtype
12016 -- Case of no constraints present
12018 if Nkind (S) /= N_Subtype_Indication then
12021 Check_Incomplete (S);
12024 -- Case of constraint present, so that we have an N_Subtype_Indication
12025 -- node (this node is created only if constraints are present).
12029 Find_Type (Subtype_Mark (S));
12031 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
12033 (Nkind (Parent (S)) = N_Subtype_Declaration
12035 Is_Itype (Defining_Identifier (Parent (S))))
12037 Check_Incomplete (Subtype_Mark (S));
12041 Subtype_Mark_Id := Entity (Subtype_Mark (S));
12043 if Is_Unchecked_Union (Subtype_Mark_Id)
12044 and then Comes_From_Source (Related_Nod)
12047 ("cannot create subtype of Unchecked_Union", Related_Nod);
12050 -- Explicit subtype declaration case
12052 if Nkind (P) = N_Subtype_Declaration then
12053 Def_Id := Defining_Identifier (P);
12055 -- Explicit derived type definition case
12057 elsif Nkind (P) = N_Derived_Type_Definition then
12058 Def_Id := Defining_Identifier (Parent (P));
12060 -- Implicit case, the Def_Id must be created as an implicit type.
12061 -- The one exception arises in the case of concurrent types,
12062 -- array and access types, where other subsidiary implicit types
12063 -- may be created and must appear before the main implicit type.
12064 -- In these cases we leave Def_Id set to Empty as a signal that
12065 -- Create_Itype has not yet been called to create Def_Id.
12068 if Is_Array_Type (Subtype_Mark_Id)
12069 or else Is_Concurrent_Type (Subtype_Mark_Id)
12070 or else Is_Access_Type (Subtype_Mark_Id)
12074 -- For the other cases, we create a new unattached Itype,
12075 -- and set the indication to ensure it gets attached later.
12079 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12083 -- If the kind of constraint is invalid for this kind of type,
12084 -- then give an error, and then pretend no constraint was given.
12086 if not Is_Valid_Constraint_Kind
12087 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
12090 ("incorrect constraint for this kind of type", Constraint (S));
12092 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
12094 -- Make recursive call, having got rid of the bogus constraint
12096 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
12099 -- Remaining processing depends on type
12101 case Ekind (Subtype_Mark_Id) is
12103 when Access_Kind =>
12104 Constrain_Access (Def_Id, S, Related_Nod);
12107 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
12109 when Decimal_Fixed_Point_Kind =>
12110 Constrain_Decimal (Def_Id, S);
12112 when Enumeration_Kind =>
12113 Constrain_Enumeration (Def_Id, S);
12115 when Ordinary_Fixed_Point_Kind =>
12116 Constrain_Ordinary_Fixed (Def_Id, S);
12119 Constrain_Float (Def_Id, S);
12121 when Integer_Kind =>
12122 Constrain_Integer (Def_Id, S);
12124 when E_Record_Type |
12127 E_Incomplete_Type =>
12128 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
12130 when Private_Kind =>
12131 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
12132 Set_Private_Dependents (Def_Id, New_Elmt_List);
12134 -- In case of an invalid constraint prevent further processing
12135 -- since the type constructed is missing expected fields.
12137 if Etype (Def_Id) = Any_Type then
12141 -- If the full view is that of a task with discriminants,
12142 -- we must constrain both the concurrent type and its
12143 -- corresponding record type. Otherwise we will just propagate
12144 -- the constraint to the full view, if available.
12146 if Present (Full_View (Subtype_Mark_Id))
12147 and then Has_Discriminants (Subtype_Mark_Id)
12148 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
12151 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12153 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
12154 Constrain_Concurrent (Full_View_Id, S,
12155 Related_Nod, Related_Id, Suffix);
12156 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
12157 Set_Full_View (Def_Id, Full_View_Id);
12160 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
12163 when Concurrent_Kind =>
12164 Constrain_Concurrent (Def_Id, S,
12165 Related_Nod, Related_Id, Suffix);
12168 Error_Msg_N ("invalid subtype mark in subtype indication", S);
12171 -- Size and Convention are always inherited from the base type
12173 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
12174 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
12179 end Process_Subtype;
12181 -----------------------------
12182 -- Record_Type_Declaration --
12183 -----------------------------
12185 procedure Record_Type_Declaration
12190 Def : constant Node_Id := Type_Definition (N);
12192 Is_Tagged : Boolean;
12193 Tag_Comp : Entity_Id;
12196 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
12197 -- if it detected an error for declaration T. This arises in the case of
12198 -- private tagged types where the full view omits the word tagged.
12200 Is_Tagged := Tagged_Present (Def)
12201 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
12203 -- Records constitute a scope for the component declarations within.
12204 -- The scope is created prior to the processing of these declarations.
12205 -- Discriminants are processed first, so that they are visible when
12206 -- processing the other components. The Ekind of the record type itself
12207 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
12209 -- Enter record scope
12213 -- These flags must be initialized before calling Process_Discriminants
12214 -- because this routine makes use of them.
12216 Set_Is_Tagged_Type (T, Is_Tagged);
12217 Set_Is_Limited_Record (T, Limited_Present (Def));
12219 -- Type is abstract if full declaration carries keyword, or if
12220 -- previous partial view did.
12222 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
12224 Set_Ekind (T, E_Record_Type);
12226 Init_Size_Align (T);
12228 Set_Stored_Constraint (T, No_Elist);
12230 -- If an incomplete or private type declaration was already given for
12231 -- the type, then this scope already exists, and the discriminants have
12232 -- been declared within. We must verify that the full declaration
12233 -- matches the incomplete one.
12235 Check_Or_Process_Discriminants (N, T, Prev);
12237 Set_Is_Constrained (T, not Has_Discriminants (T));
12238 Set_Has_Delayed_Freeze (T, True);
12240 -- For tagged types add a manually analyzed component corresponding
12241 -- to the component _tag, the corresponding piece of tree will be
12242 -- expanded as part of the freezing actions if it is not a CPP_Class.
12245 -- Do not add the tag unless we are in expansion mode.
12247 if Expander_Active then
12248 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
12249 Enter_Name (Tag_Comp);
12251 Set_Is_Tag (Tag_Comp);
12252 Set_Ekind (Tag_Comp, E_Component);
12253 Set_Etype (Tag_Comp, RTE (RE_Tag));
12254 Set_DT_Entry_Count (Tag_Comp, No_Uint);
12255 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
12256 Init_Component_Location (Tag_Comp);
12259 Make_Class_Wide_Type (T);
12260 Set_Primitive_Operations (T, New_Elmt_List);
12263 -- We must suppress range checks when processing the components
12264 -- of a record in the presence of discriminants, since we don't
12265 -- want spurious checks to be generated during their analysis, but
12266 -- must reset the Suppress_Range_Checks flags after having processed
12267 -- the record definition.
12269 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
12270 Set_Kill_Range_Checks (T, True);
12271 Record_Type_Definition (Def, Prev);
12272 Set_Kill_Range_Checks (T, False);
12274 Record_Type_Definition (Def, Prev);
12277 -- Exit from record scope
12280 end Record_Type_Declaration;
12282 ----------------------------
12283 -- Record_Type_Definition --
12284 ----------------------------
12286 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
12287 Component : Entity_Id;
12288 Ctrl_Components : Boolean := False;
12289 Final_Storage_Only : Boolean;
12293 if Ekind (Prev_T) = E_Incomplete_Type then
12294 T := Full_View (Prev_T);
12299 Final_Storage_Only := not Is_Controlled (T);
12301 -- If the component list of a record type is defined by the reserved
12302 -- word null and there is no discriminant part, then the record type has
12303 -- no components and all records of the type are null records (RM 3.7)
12304 -- This procedure is also called to process the extension part of a
12305 -- record extension, in which case the current scope may have inherited
12309 or else No (Component_List (Def))
12310 or else Null_Present (Component_List (Def))
12315 Analyze_Declarations (Component_Items (Component_List (Def)));
12317 if Present (Variant_Part (Component_List (Def))) then
12318 Analyze (Variant_Part (Component_List (Def)));
12322 -- After completing the semantic analysis of the record definition,
12323 -- record components, both new and inherited, are accessible. Set
12324 -- their kind accordingly.
12326 Component := First_Entity (Current_Scope);
12327 while Present (Component) loop
12329 if Ekind (Component) = E_Void then
12330 Set_Ekind (Component, E_Component);
12331 Init_Component_Location (Component);
12334 if Has_Task (Etype (Component)) then
12338 if Ekind (Component) /= E_Component then
12341 elsif Has_Controlled_Component (Etype (Component))
12342 or else (Chars (Component) /= Name_uParent
12343 and then Is_Controlled (Etype (Component)))
12345 Set_Has_Controlled_Component (T, True);
12346 Final_Storage_Only := Final_Storage_Only
12347 and then Finalize_Storage_Only (Etype (Component));
12348 Ctrl_Components := True;
12351 Next_Entity (Component);
12354 -- A type is Finalize_Storage_Only only if all its controlled
12355 -- components are so.
12357 if Ctrl_Components then
12358 Set_Finalize_Storage_Only (T, Final_Storage_Only);
12361 -- Place reference to end record on the proper entity, which may
12362 -- be a partial view.
12364 if Present (Def) then
12365 Process_End_Label (Def, 'e', Prev_T);
12367 end Record_Type_Definition;
12369 ------------------------
12370 -- Replace_Components --
12371 ------------------------
12373 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
12374 function Process (N : Node_Id) return Traverse_Result;
12380 function Process (N : Node_Id) return Traverse_Result is
12384 if Nkind (N) = N_Discriminant_Specification then
12385 Comp := First_Discriminant (Typ);
12387 while Present (Comp) loop
12388 if Chars (Comp) = Chars (Defining_Identifier (N)) then
12389 Set_Defining_Identifier (N, Comp);
12393 Next_Discriminant (Comp);
12396 elsif Nkind (N) = N_Component_Declaration then
12397 Comp := First_Component (Typ);
12399 while Present (Comp) loop
12400 if Chars (Comp) = Chars (Defining_Identifier (N)) then
12401 Set_Defining_Identifier (N, Comp);
12405 Next_Component (Comp);
12412 procedure Replace is new Traverse_Proc (Process);
12414 -- Start of processing for Replace_Components
12418 end Replace_Components;
12420 -------------------------------
12421 -- Set_Completion_Referenced --
12422 -------------------------------
12424 procedure Set_Completion_Referenced (E : Entity_Id) is
12426 -- If in main unit, mark entity that is a completion as referenced,
12427 -- warnings go on the partial view when needed.
12429 if In_Extended_Main_Source_Unit (E) then
12430 Set_Referenced (E);
12432 end Set_Completion_Referenced;
12434 ---------------------
12435 -- Set_Fixed_Range --
12436 ---------------------
12438 -- The range for fixed-point types is complicated by the fact that we
12439 -- do not know the exact end points at the time of the declaration. This
12440 -- is true for three reasons:
12442 -- A size clause may affect the fudging of the end-points
12443 -- A small clause may affect the values of the end-points
12444 -- We try to include the end-points if it does not affect the size
12446 -- This means that the actual end-points must be established at the
12447 -- point when the type is frozen. Meanwhile, we first narrow the range
12448 -- as permitted (so that it will fit if necessary in a small specified
12449 -- size), and then build a range subtree with these narrowed bounds.
12451 -- Set_Fixed_Range constructs the range from real literal values, and
12452 -- sets the range as the Scalar_Range of the given fixed-point type
12455 -- The parent of this range is set to point to the entity so that it
12456 -- is properly hooked into the tree (unlike normal Scalar_Range entries
12457 -- for other scalar types, which are just pointers to the range in the
12458 -- original tree, this would otherwise be an orphan).
12460 -- The tree is left unanalyzed. When the type is frozen, the processing
12461 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
12462 -- analyzed, and uses this as an indication that it should complete
12463 -- work on the range (it will know the final small and size values).
12465 procedure Set_Fixed_Range
12471 S : constant Node_Id :=
12473 Low_Bound => Make_Real_Literal (Loc, Lo),
12474 High_Bound => Make_Real_Literal (Loc, Hi));
12477 Set_Scalar_Range (E, S);
12479 end Set_Fixed_Range;
12481 ----------------------------------
12482 -- Set_Scalar_Range_For_Subtype --
12483 ----------------------------------
12485 procedure Set_Scalar_Range_For_Subtype
12486 (Def_Id : Entity_Id;
12490 Kind : constant Entity_Kind := Ekind (Def_Id);
12492 Set_Scalar_Range (Def_Id, R);
12494 -- We need to link the range into the tree before resolving it so
12495 -- that types that are referenced, including importantly the subtype
12496 -- itself, are properly frozen (Freeze_Expression requires that the
12497 -- expression be properly linked into the tree). Of course if it is
12498 -- already linked in, then we do not disturb the current link.
12500 if No (Parent (R)) then
12501 Set_Parent (R, Def_Id);
12504 -- Reset the kind of the subtype during analysis of the range, to
12505 -- catch possible premature use in the bounds themselves.
12507 Set_Ekind (Def_Id, E_Void);
12508 Process_Range_Expr_In_Decl (R, Subt);
12509 Set_Ekind (Def_Id, Kind);
12511 end Set_Scalar_Range_For_Subtype;
12513 --------------------------------------------------------
12514 -- Set_Stored_Constraint_From_Discriminant_Constraint --
12515 --------------------------------------------------------
12517 procedure Set_Stored_Constraint_From_Discriminant_Constraint
12521 -- Make sure set if encountered during
12522 -- Expand_To_Stored_Constraint
12524 Set_Stored_Constraint (E, No_Elist);
12526 -- Give it the right value
12528 if Is_Constrained (E) and then Has_Discriminants (E) then
12529 Set_Stored_Constraint (E,
12530 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
12533 end Set_Stored_Constraint_From_Discriminant_Constraint;
12535 -------------------------------------
12536 -- Signed_Integer_Type_Declaration --
12537 -------------------------------------
12539 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
12540 Implicit_Base : Entity_Id;
12541 Base_Typ : Entity_Id;
12544 Errs : Boolean := False;
12548 function Can_Derive_From (E : Entity_Id) return Boolean;
12549 -- Determine whether given bounds allow derivation from specified type
12551 procedure Check_Bound (Expr : Node_Id);
12552 -- Check bound to make sure it is integral and static. If not, post
12553 -- appropriate error message and set Errs flag
12555 ---------------------
12556 -- Can_Derive_From --
12557 ---------------------
12559 function Can_Derive_From (E : Entity_Id) return Boolean is
12560 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
12561 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
12564 -- Note we check both bounds against both end values, to deal with
12565 -- strange types like ones with a range of 0 .. -12341234.
12567 return Lo <= Lo_Val and then Lo_Val <= Hi
12569 Lo <= Hi_Val and then Hi_Val <= Hi;
12570 end Can_Derive_From;
12576 procedure Check_Bound (Expr : Node_Id) is
12578 -- If a range constraint is used as an integer type definition, each
12579 -- bound of the range must be defined by a static expression of some
12580 -- integer type, but the two bounds need not have the same integer
12581 -- type (Negative bounds are allowed.) (RM 3.5.4)
12583 if not Is_Integer_Type (Etype (Expr)) then
12585 ("integer type definition bounds must be of integer type", Expr);
12588 elsif not Is_OK_Static_Expression (Expr) then
12589 Flag_Non_Static_Expr
12590 ("non-static expression used for integer type bound!", Expr);
12593 -- The bounds are folded into literals, and we set their type to be
12594 -- universal, to avoid typing difficulties: we cannot set the type
12595 -- of the literal to the new type, because this would be a forward
12596 -- reference for the back end, and if the original type is user-
12597 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
12600 if Is_Entity_Name (Expr) then
12601 Fold_Uint (Expr, Expr_Value (Expr), True);
12604 Set_Etype (Expr, Universal_Integer);
12608 -- Start of processing for Signed_Integer_Type_Declaration
12611 -- Create an anonymous base type
12614 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
12616 -- Analyze and check the bounds, they can be of any integer type
12618 Lo := Low_Bound (Def);
12619 Hi := High_Bound (Def);
12621 -- Arbitrarily use Integer as the type if either bound had an error
12623 if Hi = Error or else Lo = Error then
12624 Base_Typ := Any_Integer;
12625 Set_Error_Posted (T, True);
12627 -- Here both bounds are OK expressions
12630 Analyze_And_Resolve (Lo, Any_Integer);
12631 Analyze_And_Resolve (Hi, Any_Integer);
12637 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12638 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12641 -- Find type to derive from
12643 Lo_Val := Expr_Value (Lo);
12644 Hi_Val := Expr_Value (Hi);
12646 if Can_Derive_From (Standard_Short_Short_Integer) then
12647 Base_Typ := Base_Type (Standard_Short_Short_Integer);
12649 elsif Can_Derive_From (Standard_Short_Integer) then
12650 Base_Typ := Base_Type (Standard_Short_Integer);
12652 elsif Can_Derive_From (Standard_Integer) then
12653 Base_Typ := Base_Type (Standard_Integer);
12655 elsif Can_Derive_From (Standard_Long_Integer) then
12656 Base_Typ := Base_Type (Standard_Long_Integer);
12658 elsif Can_Derive_From (Standard_Long_Long_Integer) then
12659 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12662 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12663 Error_Msg_N ("integer type definition bounds out of range", Def);
12664 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12665 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12669 -- Complete both implicit base and declared first subtype entities
12671 Set_Etype (Implicit_Base, Base_Typ);
12672 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
12673 Set_Size_Info (Implicit_Base, (Base_Typ));
12674 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
12675 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
12677 Set_Ekind (T, E_Signed_Integer_Subtype);
12678 Set_Etype (T, Implicit_Base);
12680 Set_Size_Info (T, (Implicit_Base));
12681 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
12682 Set_Scalar_Range (T, Def);
12683 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
12684 Set_Is_Constrained (T);
12685 end Signed_Integer_Type_Declaration;