1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004, 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 Rident; use Rident;
47 with Rtsfind; use Rtsfind;
49 with Sem_Case; use Sem_Case;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch7; use Sem_Ch7;
53 with Sem_Ch8; use Sem_Ch8;
54 with Sem_Ch13; use Sem_Ch13;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Elim; use Sem_Elim;
58 with Sem_Eval; use Sem_Eval;
59 with Sem_Mech; use Sem_Mech;
60 with Sem_Res; use Sem_Res;
61 with Sem_Smem; use Sem_Smem;
62 with Sem_Type; use Sem_Type;
63 with Sem_Util; use Sem_Util;
64 with Sem_Warn; use Sem_Warn;
65 with Stand; use Stand;
66 with Sinfo; use Sinfo;
67 with Snames; use Snames;
68 with Tbuild; use Tbuild;
69 with Ttypes; use Ttypes;
70 with Uintp; use Uintp;
71 with Urealp; use Urealp;
73 package body Sem_Ch3 is
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 procedure Build_Derived_Type
81 Parent_Type : Entity_Id;
82 Derived_Type : Entity_Id;
83 Is_Completion : Boolean;
84 Derive_Subps : Boolean := True);
85 -- Create and decorate a Derived_Type given the Parent_Type entity.
86 -- N is the N_Full_Type_Declaration node containing the derived type
87 -- definition. Parent_Type is the entity for the parent type in the derived
88 -- type definition and Derived_Type the actual derived type. Is_Completion
89 -- must be set to False if Derived_Type is the N_Defining_Identifier node
90 -- in N (ie Derived_Type = Defining_Identifier (N)). In this case N is not
91 -- the completion of a private type declaration. If Is_Completion is
92 -- set to True, N is the completion of a private type declaration and
93 -- Derived_Type is different from the defining identifier inside N (i.e.
94 -- Derived_Type /= Defining_Identifier (N)). Derive_Subps indicates whether
95 -- the parent subprograms should be derived. The only case where this
96 -- parameter is False is when Build_Derived_Type is recursively called to
97 -- process an implicit derived full type for a type derived from a private
98 -- type (in that case the subprograms must only be derived for the private
100 -- ??? These flags need a bit of re-examination and re-documentation:
101 -- ??? are they both necessary (both seem related to the recursion)?
103 procedure Build_Derived_Access_Type
105 Parent_Type : Entity_Id;
106 Derived_Type : Entity_Id);
107 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
108 -- create an implicit base if the parent type is constrained or if the
109 -- subtype indication has a constraint.
111 procedure Build_Derived_Array_Type
113 Parent_Type : Entity_Id;
114 Derived_Type : Entity_Id);
115 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
116 -- create an implicit base if the parent type is constrained or if the
117 -- subtype indication has a constraint.
119 procedure Build_Derived_Concurrent_Type
121 Parent_Type : Entity_Id;
122 Derived_Type : Entity_Id);
123 -- Subsidiary procedure to Build_Derived_Type. For a derived task or pro-
124 -- tected type, inherit entries and protected subprograms, check legality
125 -- of discriminant constraints if any.
127 procedure Build_Derived_Enumeration_Type
129 Parent_Type : Entity_Id;
130 Derived_Type : Entity_Id);
131 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
132 -- type, we must create a new list of literals. Types derived from
133 -- Character and Wide_Character are special-cased.
135 procedure Build_Derived_Numeric_Type
137 Parent_Type : Entity_Id;
138 Derived_Type : Entity_Id);
139 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
140 -- an anonymous base type, and propagate constraint to subtype if needed.
142 procedure Build_Derived_Private_Type
144 Parent_Type : Entity_Id;
145 Derived_Type : Entity_Id;
146 Is_Completion : Boolean;
147 Derive_Subps : Boolean := True);
148 -- Subsidiary procedure to Build_Derived_Type. This procedure is complex
149 -- because the parent may or may not have a completion, and the derivation
150 -- may itself be a completion.
152 procedure Build_Derived_Record_Type
154 Parent_Type : Entity_Id;
155 Derived_Type : Entity_Id;
156 Derive_Subps : Boolean := True);
157 -- Subsidiary procedure to Build_Derived_Type and
158 -- Analyze_Private_Extension_Declaration used for tagged and untagged
159 -- record types. All parameters are as in Build_Derived_Type except that
160 -- N, in addition to being an N_Full_Type_Declaration node, can also be an
161 -- N_Private_Extension_Declaration node. See the definition of this routine
162 -- for much more info. Derive_Subps indicates whether subprograms should
163 -- be derived from the parent type. The only case where Derive_Subps is
164 -- False is for an implicit derived full type for a type derived from a
165 -- private type (see Build_Derived_Type).
167 function Inherit_Components
169 Parent_Base : Entity_Id;
170 Derived_Base : Entity_Id;
172 Inherit_Discr : Boolean;
173 Discs : Elist_Id) return Elist_Id;
174 -- Called from Build_Derived_Record_Type to inherit the components of
175 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
176 -- For more information on derived types and component inheritance please
177 -- consult the comment above the body of Build_Derived_Record_Type.
179 -- N is the original derived type declaration.
181 -- Is_Tagged is set if we are dealing with tagged types.
183 -- If Inherit_Discr is set, Derived_Base inherits its discriminants
184 -- from Parent_Base, otherwise no discriminants are inherited.
186 -- Discs gives the list of constraints that apply to Parent_Base in the
187 -- derived type declaration. If Discs is set to No_Elist, then we have
188 -- the following situation:
190 -- type Parent (D1..Dn : ..) is [tagged] record ...;
191 -- type Derived is new Parent [with ...];
193 -- which gets treated as
195 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
197 -- For untagged types the returned value is an association list. The list
198 -- starts from the association (Parent_Base => Derived_Base), and then it
199 -- contains a sequence of the associations of the form
201 -- (Old_Component => New_Component),
203 -- where Old_Component is the Entity_Id of a component in Parent_Base
204 -- and New_Component is the Entity_Id of the corresponding component
205 -- in Derived_Base. For untagged records, this association list is
206 -- needed when copying the record declaration for the derived base.
207 -- In the tagged case the value returned is irrelevant.
209 procedure Build_Discriminal (Discrim : Entity_Id);
210 -- Create the discriminal corresponding to discriminant Discrim, that is
211 -- the parameter corresponding to Discrim to be used in initialization
212 -- procedures for the type where Discrim is a discriminant. Discriminals
213 -- are not used during semantic analysis, and are not fully defined
214 -- entities until expansion. Thus they are not given a scope until
215 -- initialization procedures are built.
217 function Build_Discriminant_Constraints
220 Derived_Def : Boolean := False) return Elist_Id;
221 -- Validate discriminant constraints, and return the list of the
222 -- constraints in order of discriminant declarations. T is the
223 -- discriminated unconstrained type. Def is the N_Subtype_Indication
224 -- node where the discriminants constraints for T are specified.
225 -- Derived_Def is True if we are building the discriminant constraints
226 -- in a derived type definition of the form "type D (...) is new T (xxx)".
227 -- In this case T is the parent type and Def is the constraint "(xxx)" on
228 -- T and this routine sets the Corresponding_Discriminant field of the
229 -- discriminants in the derived type D to point to the corresponding
230 -- discriminants in the parent type T.
232 procedure Build_Discriminated_Subtype
236 Related_Nod : Node_Id;
237 For_Access : Boolean := False);
238 -- Subsidiary procedure to Constrain_Discriminated_Type and to
239 -- Process_Incomplete_Dependents. Given
241 -- T (a possibly discriminated base type)
242 -- Def_Id (a very partially built subtype for T),
244 -- the call completes Def_Id to be the appropriate E_*_Subtype.
246 -- The Elist is the list of discriminant constraints if any (it is set to
247 -- No_Elist if T is not a discriminated type, and to an empty list if
248 -- T has discriminants but there are no discriminant constraints). The
249 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
250 -- The For_Access says whether or not this subtype is really constraining
251 -- an access type. That is its sole purpose is the designated type of an
252 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
253 -- is built to avoid freezing T when the access subtype is frozen.
255 function Build_Scalar_Bound
258 Der_T : Entity_Id) return Node_Id;
259 -- The bounds of a derived scalar type are conversions of the bounds of
260 -- the parent type. Optimize the representation if the bounds are literals.
261 -- Needs a more complete spec--what are the parameters exactly, and what
262 -- exactly is the returned value, and how is Bound affected???
264 procedure Build_Underlying_Full_View
268 -- If the completion of a private type is itself derived from a private
269 -- type, or if the full view of a private subtype is itself private, the
270 -- back-end has no way to compute the actual size of this type. We build
271 -- an internal subtype declaration of the proper parent type to convey
272 -- this information. This extra mechanism is needed because a full
273 -- view cannot itself have a full view (it would get clobbered during
276 procedure Check_Access_Discriminant_Requires_Limited
279 -- Check the restriction that the type to which an access discriminant
280 -- belongs must be a concurrent type or a descendant of a type with
281 -- the reserved word 'limited' in its declaration.
283 procedure Check_Delta_Expression (E : Node_Id);
284 -- Check that the expression represented by E is suitable for use
285 -- as a delta expression, i.e. it is of real type and is static.
287 procedure Check_Digits_Expression (E : Node_Id);
288 -- Check that the expression represented by E is suitable for use as
289 -- a digits expression, i.e. it is of integer type, positive and static.
291 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
292 -- Validate the initialization of an object declaration. T is the
293 -- required type, and Exp is the initialization expression.
295 procedure Check_Or_Process_Discriminants
298 Prev : Entity_Id := Empty);
299 -- If T is the full declaration of an incomplete or private type, check
300 -- the conformance of the discriminants, otherwise process them. Prev
301 -- is the entity of the partial declaration, if any.
303 procedure Check_Real_Bound (Bound : Node_Id);
304 -- Check given bound for being of real type and static. If not, post an
305 -- appropriate message, and rewrite the bound with the real literal zero.
307 procedure Constant_Redeclaration
311 -- Various checks on legality of full declaration of deferred constant.
312 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
313 -- node. The caller has not yet set any attributes of this entity.
315 procedure Convert_Scalar_Bounds
317 Parent_Type : Entity_Id;
318 Derived_Type : Entity_Id;
320 -- For derived scalar types, convert the bounds in the type definition
321 -- to the derived type, and complete their analysis. Given a constraint
323 -- .. new T range Lo .. Hi;
324 -- Lo and Hi are analyzed and resolved with T'Base, the parent_type.
325 -- The bounds of the derived type (the anonymous base) are copies of
326 -- Lo and Hi. Finally, the bounds of the derived subtype are conversions
327 -- of those bounds to the derived_type, so that their typing is
330 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
331 -- Copies attributes from array base type T2 to array base type T1.
332 -- Copies only attributes that apply to base types, but not subtypes.
334 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
335 -- Copies attributes from array subtype T2 to array subtype T1. Copies
336 -- attributes that apply to both subtypes and base types.
338 procedure Create_Constrained_Components
342 Constraints : Elist_Id);
343 -- Build the list of entities for a constrained discriminated record
344 -- subtype. If a component depends on a discriminant, replace its subtype
345 -- using the discriminant values in the discriminant constraint.
346 -- Subt is the defining identifier for the subtype whose list of
347 -- constrained entities we will create. Decl_Node is the type declaration
348 -- node where we will attach all the itypes created. Typ is the base
349 -- discriminated type for the subtype Subt. Constraints is the list of
350 -- discriminant constraints for Typ.
352 function Constrain_Component_Type
353 (Compon_Type : Entity_Id;
354 Constrained_Typ : Entity_Id;
355 Related_Node : Node_Id;
357 Constraints : Elist_Id) return Entity_Id;
358 -- Given a discriminated base type Typ, a list of discriminant constraint
359 -- Constraints for Typ and the type of a component of Typ, Compon_Type,
360 -- create and return the type corresponding to Compon_type where all
361 -- discriminant references are replaced with the corresponding
362 -- constraint. If no discriminant references occur in Compon_Typ then
363 -- return it as is. Constrained_Typ is the final constrained subtype to
364 -- which the constrained Compon_Type belongs. Related_Node is the node
365 -- where we will attach all the itypes created.
367 procedure Constrain_Access
368 (Def_Id : in out Entity_Id;
370 Related_Nod : Node_Id);
371 -- Apply a list of constraints to an access type. If Def_Id is empty,
372 -- it is an anonymous type created for a subtype indication. In that
373 -- case it is created in the procedure and attached to Related_Nod.
375 procedure Constrain_Array
376 (Def_Id : in out Entity_Id;
378 Related_Nod : Node_Id;
379 Related_Id : Entity_Id;
381 -- Apply a list of index constraints to an unconstrained array type. The
382 -- first parameter is the entity for the resulting subtype. A value of
383 -- Empty for Def_Id indicates that an implicit type must be created, but
384 -- creation is delayed (and must be done by this procedure) because other
385 -- subsidiary implicit types must be created first (which is why Def_Id
386 -- is an in/out parameter). The second parameter is a subtype indication
387 -- node for the constrained array to be created (e.g. something of the
388 -- form string (1 .. 10)). Related_Nod gives the place where this type
389 -- has to be inserted in the tree. The Related_Id and Suffix parameters
390 -- are used to build the associated Implicit type name.
392 procedure Constrain_Concurrent
393 (Def_Id : in out Entity_Id;
395 Related_Nod : Node_Id;
396 Related_Id : Entity_Id;
398 -- Apply list of discriminant constraints to an unconstrained concurrent
401 -- SI is the N_Subtype_Indication node containing the constraint and
402 -- the unconstrained type to constrain.
404 -- Def_Id is the entity for the resulting constrained subtype. A value
405 -- of Empty for Def_Id indicates that an implicit type must be created,
406 -- but creation is delayed (and must be done by this procedure) because
407 -- other subsidiary implicit types must be created first (which is why
408 -- Def_Id is an in/out parameter).
410 -- Related_Nod gives the place where this type has to be inserted
413 -- The last two arguments are used to create its external name if needed.
415 function Constrain_Corresponding_Record
416 (Prot_Subt : Entity_Id;
417 Corr_Rec : Entity_Id;
418 Related_Nod : Node_Id;
419 Related_Id : Entity_Id) return Entity_Id;
420 -- When constraining a protected type or task type with discriminants,
421 -- constrain the corresponding record with the same discriminant values.
423 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
424 -- Constrain a decimal fixed point type with a digits constraint and/or a
425 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
427 procedure Constrain_Discriminated_Type
430 Related_Nod : Node_Id;
431 For_Access : Boolean := False);
432 -- Process discriminant constraints of composite type. Verify that values
433 -- have been provided for all discriminants, that the original type is
434 -- unconstrained, and that the types of the supplied expressions match
435 -- the discriminant types. The first three parameters are like in routine
436 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
439 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
440 -- Constrain an enumeration type with a range constraint. This is
441 -- identical to Constrain_Integer, but for the Ekind of the
442 -- resulting subtype.
444 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
445 -- Constrain a floating point type with either a digits constraint
446 -- and/or a range constraint, building a E_Floating_Point_Subtype.
448 procedure Constrain_Index
451 Related_Nod : Node_Id;
452 Related_Id : Entity_Id;
455 -- Process an index constraint in a constrained array declaration. The
456 -- constraint can be a subtype name, or a range with or without an
457 -- explicit subtype mark. The index is the corresponding index of the
458 -- unconstrained array. The Related_Id and Suffix parameters are used to
459 -- build the associated Implicit type name.
461 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
462 -- Build subtype of a signed or modular integer type
464 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
465 -- Constrain an ordinary fixed point type with a range constraint, and
466 -- build an E_Ordinary_Fixed_Point_Subtype entity.
468 procedure Copy_And_Swap (Priv, Full : Entity_Id);
469 -- Copy the Priv entity into the entity of its full declaration
470 -- then swap the two entities in such a manner that the former private
471 -- type is now seen as a full type.
473 procedure Decimal_Fixed_Point_Type_Declaration
476 -- Create a new decimal fixed point type, and apply the constraint to
477 -- obtain a subtype of this new type.
479 procedure Complete_Private_Subtype
482 Full_Base : Entity_Id;
483 Related_Nod : Node_Id);
484 -- Complete the implicit full view of a private subtype by setting
485 -- the appropriate semantic fields. If the full view of the parent is
486 -- a record type, build constrained components of subtype.
488 procedure Derived_Standard_Character
490 Parent_Type : Entity_Id;
491 Derived_Type : Entity_Id);
492 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
493 -- derivations from types Standard.Character and Standard.Wide_Character.
495 procedure Derived_Type_Declaration
498 Is_Completion : Boolean);
499 -- Process a derived type declaration. This routine will invoke
500 -- Build_Derived_Type to process the actual derived type definition.
501 -- Parameters N and Is_Completion have the same meaning as in
502 -- Build_Derived_Type. T is the N_Defining_Identifier for the entity
503 -- defined in the N_Full_Type_Declaration node N, that is T is the
506 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
507 -- Given a subtype indication S (which is really an N_Subtype_Indication
508 -- node or a plain N_Identifier), find the type of the subtype mark.
510 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
511 -- Insert each literal in symbol table, as an overloadable identifier
512 -- Each enumeration type is mapped into a sequence of integers, and
513 -- each literal is defined as a constant with integer value. If any
514 -- of the literals are character literals, the type is a character
515 -- type, which means that strings are legal aggregates for arrays of
516 -- components of the type.
518 function Expand_To_Stored_Constraint
520 Constraint : Elist_Id) return Elist_Id;
521 -- Given a Constraint (ie a list of expressions) on the discriminants of
522 -- Typ, expand it into a constraint on the stored discriminants and
523 -- return the new list of expressions constraining the stored
526 function Find_Type_Of_Object
528 Related_Nod : Node_Id) return Entity_Id;
529 -- Get type entity for object referenced by Obj_Def, attaching the
530 -- implicit types generated to Related_Nod
532 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
533 -- Create a new float, and apply the constraint to obtain subtype of it
535 function Has_Range_Constraint (N : Node_Id) return Boolean;
536 -- Given an N_Subtype_Indication node N, return True if a range constraint
537 -- is present, either directly, or as part of a digits or delta constraint.
538 -- In addition, a digits constraint in the decimal case returns True, since
539 -- it establishes a default range if no explicit range is present.
541 function Is_Valid_Constraint_Kind
543 Constraint_Kind : Node_Kind) return Boolean;
544 -- Returns True if it is legal to apply the given kind of constraint
545 -- to the given kind of type (index constraint to an array type,
548 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
549 -- Create new modular type. Verify that modulus is in bounds and is
550 -- a power of two (implementation restriction).
552 procedure New_Concatenation_Op (Typ : Entity_Id);
553 -- Create an abbreviated declaration for an operator in order to
554 -- materialize concatenation on array types.
556 procedure Ordinary_Fixed_Point_Type_Declaration
559 -- Create a new ordinary fixed point type, and apply the constraint
560 -- to obtain subtype of it.
562 procedure Prepare_Private_Subtype_Completion
564 Related_Nod : Node_Id);
565 -- Id is a subtype of some private type. Creates the full declaration
566 -- associated with Id whenever possible, i.e. when the full declaration
567 -- of the base type is already known. Records each subtype into
568 -- Private_Dependents of the base type.
570 procedure Process_Incomplete_Dependents
574 -- Process all entities that depend on an incomplete type. There include
575 -- subtypes, subprogram types that mention the incomplete type in their
576 -- profiles, and subprogram with access parameters that designate the
579 -- Inc_T is the defining identifier of an incomplete type declaration, its
580 -- Ekind is E_Incomplete_Type.
582 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
584 -- Full_T is N's defining identifier.
586 -- Subtypes of incomplete types with discriminants are completed when the
587 -- parent type is. This is simpler than private subtypes, because they can
588 -- only appear in the same scope, and there is no need to exchange views.
589 -- Similarly, access_to_subprogram types may have a parameter or a return
590 -- type that is an incomplete type, and that must be replaced with the
593 -- If the full type is tagged, subprogram with access parameters that
594 -- designated the incomplete may be primitive operations of the full type,
595 -- and have to be processed accordingly.
597 procedure Process_Real_Range_Specification (Def : Node_Id);
598 -- Given the type definition for a real type, this procedure processes
599 -- and checks the real range specification of this type definition if
600 -- one is present. If errors are found, error messages are posted, and
601 -- the Real_Range_Specification of Def is reset to Empty.
603 procedure Record_Type_Declaration
607 -- Process a record type declaration (for both untagged and tagged
608 -- records). Parameters T and N are exactly like in procedure
609 -- Derived_Type_Declaration, except that no flag Is_Completion is
610 -- needed for this routine. If this is the completion of an incomplete
611 -- type declaration, Prev is the entity of the incomplete declaration,
612 -- used for cross-referencing. Otherwise Prev = T.
614 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
615 -- This routine is used to process the actual record type definition
616 -- (both for untagged and tagged records). Def is a record type
617 -- definition node. This procedure analyzes the components in this
618 -- record type definition. Prev_T is the entity for the enclosing record
619 -- type. It is provided so that its Has_Task flag can be set if any of
620 -- the component have Has_Task set. If the declaration is the completion
621 -- of an incomplete type declaration, Prev_T is the original incomplete
622 -- type, whose full view is the record type.
624 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
625 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we
626 -- build a copy of the declaration tree of the parent, and we create
627 -- independently the list of components for the derived type. Semantic
628 -- information uses the component entities, but record representation
629 -- clauses are validated on the declaration tree. This procedure replaces
630 -- discriminants and components in the declaration with those that have
631 -- been created by Inherit_Components.
633 procedure Set_Fixed_Range
638 -- Build a range node with the given bounds and set it as the Scalar_Range
639 -- of the given fixed-point type entity. Loc is the source location used
640 -- for the constructed range. See body for further details.
642 procedure Set_Scalar_Range_For_Subtype
646 -- This routine is used to set the scalar range field for a subtype
647 -- given Def_Id, the entity for the subtype, and R, the range expression
648 -- for the scalar range. Subt provides the parent subtype to be used
649 -- to analyze, resolve, and check the given range.
651 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
652 -- Create a new signed integer entity, and apply the constraint to obtain
653 -- the required first named subtype of this type.
655 procedure Set_Stored_Constraint_From_Discriminant_Constraint
657 -- E is some record type. This routine computes E's Stored_Constraint
658 -- from its Discriminant_Constraint.
660 -----------------------
661 -- Access_Definition --
662 -----------------------
664 function Access_Definition
665 (Related_Nod : Node_Id;
666 N : Node_Id) return Entity_Id
668 Anon_Type : constant Entity_Id :=
669 Create_Itype (E_Anonymous_Access_Type, Related_Nod,
670 Scope_Id => Scope (Current_Scope));
671 Desig_Type : Entity_Id;
674 if Is_Entry (Current_Scope)
675 and then Is_Task_Type (Etype (Scope (Current_Scope)))
677 Error_Msg_N ("task entries cannot have access parameters", N);
680 -- Ada 2005 (AI-254): In case of anonymous access to subprograms
681 -- call the corresponding semantic routine
683 if Present (Access_To_Subprogram_Definition (N)) then
684 Access_Subprogram_Declaration
685 (T_Name => Anon_Type,
686 T_Def => Access_To_Subprogram_Definition (N));
688 if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
690 (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
693 (Anon_Type, E_Anonymous_Access_Subprogram_Type);
699 Find_Type (Subtype_Mark (N));
700 Desig_Type := Entity (Subtype_Mark (N));
702 Set_Directly_Designated_Type
703 (Anon_Type, Desig_Type);
704 Set_Etype (Anon_Type, Anon_Type);
705 Init_Size_Align (Anon_Type);
706 Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type));
708 -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
709 -- from Ada 95 semantics. In Ada 2005, anonymous access must specify
710 -- if the null value is allowed. In Ada 95 the null value is never
713 if Ada_Version >= Ada_05 then
714 Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
716 Set_Can_Never_Be_Null (Anon_Type, True);
719 -- The anonymous access type is as public as the discriminated type or
720 -- subprogram that defines it. It is imported (for back-end purposes)
721 -- if the designated type is.
723 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
725 -- Ada 2005 (AI-50217): Propagate the attribute that indicates that the
726 -- designated type comes from the limited view (for back-end purposes).
728 Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type));
730 -- Ada 2005 (AI-231): Propagate the access-constant attribute
732 Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
734 -- The context is either a subprogram declaration or an access
735 -- discriminant, in a private or a full type declaration. In the case
736 -- of a subprogram, If the designated type is incomplete, the operation
737 -- will be a primitive operation of the full type, to be updated
738 -- subsequently. If the type is imported through a limited with clause,
739 -- it is not a primitive operation of the type (which is declared
740 -- elsewhere in some other scope).
742 if Ekind (Desig_Type) = E_Incomplete_Type
743 and then not From_With_Type (Desig_Type)
744 and then Is_Overloadable (Current_Scope)
746 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
747 Set_Has_Delayed_Freeze (Current_Scope);
751 end Access_Definition;
753 -----------------------------------
754 -- Access_Subprogram_Declaration --
755 -----------------------------------
757 procedure Access_Subprogram_Declaration
761 Formals : constant List_Id := Parameter_Specifications (T_Def);
764 Desig_Type : constant Entity_Id :=
765 Create_Itype (E_Subprogram_Type, Parent (T_Def));
768 if Nkind (T_Def) = N_Access_Function_Definition then
769 Analyze (Subtype_Mark (T_Def));
770 Set_Etype (Desig_Type, Entity (Subtype_Mark (T_Def)));
772 if not (Is_Type (Etype (Desig_Type))) then
774 ("expect type in function specification", Subtype_Mark (T_Def));
778 Set_Etype (Desig_Type, Standard_Void_Type);
781 if Present (Formals) then
782 New_Scope (Desig_Type);
783 Process_Formals (Formals, Parent (T_Def));
785 -- A bit of a kludge here, End_Scope requires that the parent
786 -- pointer be set to something reasonable, but Itypes don't have
787 -- parent pointers. So we set it and then unset it ??? If and when
788 -- Itypes have proper parent pointers to their declarations, this
789 -- kludge can be removed.
791 Set_Parent (Desig_Type, T_Name);
793 Set_Parent (Desig_Type, Empty);
796 -- The return type and/or any parameter type may be incomplete. Mark
797 -- the subprogram_type as depending on the incomplete type, so that
798 -- it can be updated when the full type declaration is seen.
800 if Present (Formals) then
801 Formal := First_Formal (Desig_Type);
803 while Present (Formal) loop
804 if Ekind (Formal) /= E_In_Parameter
805 and then Nkind (T_Def) = N_Access_Function_Definition
807 Error_Msg_N ("functions can only have IN parameters", Formal);
810 if Ekind (Etype (Formal)) = E_Incomplete_Type then
811 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
812 Set_Has_Delayed_Freeze (Desig_Type);
815 Next_Formal (Formal);
819 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
820 and then not Has_Delayed_Freeze (Desig_Type)
822 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
823 Set_Has_Delayed_Freeze (Desig_Type);
826 Check_Delayed_Subprogram (Desig_Type);
828 if Protected_Present (T_Def) then
829 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
830 Set_Convention (Desig_Type, Convention_Protected);
832 Set_Ekind (T_Name, E_Access_Subprogram_Type);
835 Set_Etype (T_Name, T_Name);
836 Init_Size_Align (T_Name);
837 Set_Directly_Designated_Type (T_Name, Desig_Type);
839 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
841 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
843 Check_Restriction (No_Access_Subprograms, T_Def);
844 end Access_Subprogram_Declaration;
846 ----------------------------
847 -- Access_Type_Declaration --
848 ----------------------------
850 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
851 S : constant Node_Id := Subtype_Indication (Def);
852 P : constant Node_Id := Parent (Def);
858 -- Check for permissible use of incomplete type
860 if Nkind (S) /= N_Subtype_Indication then
863 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
864 Set_Directly_Designated_Type (T, Entity (S));
866 Set_Directly_Designated_Type (T,
867 Process_Subtype (S, P, T, 'P'));
871 Set_Directly_Designated_Type (T,
872 Process_Subtype (S, P, T, 'P'));
875 if All_Present (Def) or Constant_Present (Def) then
876 Set_Ekind (T, E_General_Access_Type);
878 Set_Ekind (T, E_Access_Type);
881 if Base_Type (Designated_Type (T)) = T then
882 Error_Msg_N ("access type cannot designate itself", S);
887 -- If the type has appeared already in a with_type clause, it is
888 -- frozen and the pointer size is already set. Else, initialize.
890 if not From_With_Type (T) then
894 Set_Is_Access_Constant (T, Constant_Present (Def));
896 Desig := Designated_Type (T);
898 -- If designated type is an imported tagged type, indicate that the
899 -- access type is also imported, and therefore restricted in its use.
900 -- The access type may already be imported, so keep setting otherwise.
902 -- Ada 2005 (AI-50217): If the non-limited view of the designated type
903 -- is available, use it as the designated type of the access type, so
904 -- that the back-end gets a usable entity.
910 if From_With_Type (Desig) then
911 Set_From_With_Type (T);
913 if Ekind (Desig) = E_Incomplete_Type then
914 N_Desig := Non_Limited_View (Desig);
916 else pragma Assert (Ekind (Desig) = E_Class_Wide_Type);
917 if From_With_Type (Etype (Desig)) then
918 N_Desig := Non_Limited_View (Etype (Desig));
920 N_Desig := Etype (Desig);
924 pragma Assert (Present (N_Desig));
925 Set_Directly_Designated_Type (T, N_Desig);
929 -- Note that Has_Task is always false, since the access type itself
930 -- is not a task type. See Einfo for more description on this point.
931 -- Exactly the same consideration applies to Has_Controlled_Component.
933 Set_Has_Task (T, False);
934 Set_Has_Controlled_Component (T, False);
936 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
939 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
940 Set_Is_Access_Constant (T, Constant_Present (Def));
941 end Access_Type_Declaration;
943 -----------------------------------
944 -- Analyze_Component_Declaration --
945 -----------------------------------
947 procedure Analyze_Component_Declaration (N : Node_Id) is
948 Id : constant Entity_Id := Defining_Identifier (N);
952 function Contains_POC (Constr : Node_Id) return Boolean;
953 -- Determines whether a constraint uses the discriminant of a record
954 -- type thus becoming a per-object constraint (POC).
960 function Contains_POC (Constr : Node_Id) return Boolean is
962 case Nkind (Constr) is
963 when N_Attribute_Reference =>
964 return Attribute_Name (Constr) = Name_Access
966 Prefix (Constr) = Scope (Entity (Prefix (Constr)));
968 when N_Discriminant_Association =>
969 return Denotes_Discriminant (Expression (Constr));
972 return Denotes_Discriminant (Constr);
974 when N_Index_Or_Discriminant_Constraint =>
976 IDC : Node_Id := First (Constraints (Constr));
979 while Present (IDC) loop
981 -- One per-object constraint is sufficent
983 if Contains_POC (IDC) then
994 return Denotes_Discriminant (Low_Bound (Constr))
996 Denotes_Discriminant (High_Bound (Constr));
998 when N_Range_Constraint =>
999 return Denotes_Discriminant (Range_Expression (Constr));
1007 -- Start of processing for Analyze_Component_Declaration
1010 Generate_Definition (Id);
1013 if Present (Subtype_Indication (Component_Definition (N))) then
1014 T := Find_Type_Of_Object
1015 (Subtype_Indication (Component_Definition (N)), N);
1017 -- Ada 2005 (AI-230): Access Definition case
1020 pragma Assert (Present
1021 (Access_Definition (Component_Definition (N))));
1023 T := Access_Definition
1025 N => Access_Definition (Component_Definition (N)));
1027 -- Ada 2005 (AI-230): In case of components that are anonymous
1028 -- access types the level of accessibility depends on the enclosing
1031 Set_Scope (T, Current_Scope); -- Ada 2005 (AI-230)
1033 -- Ada 2005 (AI-254)
1035 if Present (Access_To_Subprogram_Definition
1036 (Access_Definition (Component_Definition (N))))
1037 and then Protected_Present (Access_To_Subprogram_Definition
1039 (Component_Definition (N))))
1041 T := Replace_Anonymous_Access_To_Protected_Subprogram (N, T);
1045 -- If the subtype is a constrained subtype of the enclosing record,
1046 -- (which must have a partial view) the back-end does not handle
1047 -- properly the recursion. Rewrite the component declaration with
1048 -- an explicit subtype indication, which is acceptable to Gigi. We
1049 -- can copy the tree directly because side effects have already been
1050 -- removed from discriminant constraints.
1052 if Ekind (T) = E_Access_Subtype
1053 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
1054 and then Comes_From_Source (T)
1055 and then Nkind (Parent (T)) = N_Subtype_Declaration
1056 and then Etype (Directly_Designated_Type (T)) = Current_Scope
1059 (Subtype_Indication (Component_Definition (N)),
1060 New_Copy_Tree (Subtype_Indication (Parent (T))));
1061 T := Find_Type_Of_Object
1062 (Subtype_Indication (Component_Definition (N)), N);
1065 -- If the component declaration includes a default expression, then we
1066 -- check that the component is not of a limited type (RM 3.7(5)),
1067 -- and do the special preanalysis of the expression (see section on
1068 -- "Handling of Default and Per-Object Expressions" in the spec of
1071 if Present (Expression (N)) then
1072 Analyze_Per_Use_Expression (Expression (N), T);
1073 Check_Initialization (T, Expression (N));
1076 -- The parent type may be a private view with unknown discriminants,
1077 -- and thus unconstrained. Regular components must be constrained.
1079 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
1080 if Is_Class_Wide_Type (T) then
1082 ("class-wide subtype with unknown discriminants" &
1083 " in component declaration",
1084 Subtype_Indication (Component_Definition (N)));
1087 ("unconstrained subtype in component declaration",
1088 Subtype_Indication (Component_Definition (N)));
1091 -- Components cannot be abstract, except for the special case of
1092 -- the _Parent field (case of extending an abstract tagged type)
1094 elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then
1095 Error_Msg_N ("type of a component cannot be abstract", N);
1099 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
1101 -- The component declaration may have a per-object constraint, set
1102 -- the appropriate flag in the defining identifier of the subtype.
1104 if Present (Subtype_Indication (Component_Definition (N))) then
1106 Sindic : constant Node_Id :=
1107 Subtype_Indication (Component_Definition (N));
1110 if Nkind (Sindic) = N_Subtype_Indication
1111 and then Present (Constraint (Sindic))
1112 and then Contains_POC (Constraint (Sindic))
1114 Set_Has_Per_Object_Constraint (Id);
1119 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
1120 -- out some static checks.
1122 if Ada_Version >= Ada_05
1123 and then (Null_Exclusion_Present (Component_Definition (N))
1124 or else Can_Never_Be_Null (T))
1126 Set_Can_Never_Be_Null (Id);
1127 Null_Exclusion_Static_Checks (N);
1130 -- If this component is private (or depends on a private type),
1131 -- flag the record type to indicate that some operations are not
1134 P := Private_Component (T);
1137 -- Check for circular definitions
1139 if P = Any_Type then
1140 Set_Etype (Id, Any_Type);
1142 -- There is a gap in the visibility of operations only if the
1143 -- component type is not defined in the scope of the record type.
1145 elsif Scope (P) = Scope (Current_Scope) then
1148 elsif Is_Limited_Type (P) then
1149 Set_Is_Limited_Composite (Current_Scope);
1152 Set_Is_Private_Composite (Current_Scope);
1157 and then Is_Limited_Type (T)
1158 and then Chars (Id) /= Name_uParent
1159 and then Is_Tagged_Type (Current_Scope)
1161 if Is_Derived_Type (Current_Scope)
1162 and then not Is_Limited_Record (Root_Type (Current_Scope))
1165 ("extension of nonlimited type cannot have limited components",
1167 Explain_Limited_Type (T, N);
1168 Set_Etype (Id, Any_Type);
1169 Set_Is_Limited_Composite (Current_Scope, False);
1171 elsif not Is_Derived_Type (Current_Scope)
1172 and then not Is_Limited_Record (Current_Scope)
1175 ("nonlimited tagged type cannot have limited components", N);
1176 Explain_Limited_Type (T, N);
1177 Set_Etype (Id, Any_Type);
1178 Set_Is_Limited_Composite (Current_Scope, False);
1182 Set_Original_Record_Component (Id, Id);
1183 end Analyze_Component_Declaration;
1185 --------------------------
1186 -- Analyze_Declarations --
1187 --------------------------
1189 procedure Analyze_Declarations (L : List_Id) is
1191 Next_Node : Node_Id;
1192 Freeze_From : Entity_Id := Empty;
1195 -- Adjust D not to include implicit label declarations, since these
1196 -- have strange Sloc values that result in elaboration check problems.
1197 -- (They have the sloc of the label as found in the source, and that
1198 -- is ahead of the current declarative part).
1204 procedure Adjust_D is
1206 while Present (Prev (D))
1207 and then Nkind (D) = N_Implicit_Label_Declaration
1213 -- Start of processing for Analyze_Declarations
1217 while Present (D) loop
1219 -- Complete analysis of declaration
1222 Next_Node := Next (D);
1224 if No (Freeze_From) then
1225 Freeze_From := First_Entity (Current_Scope);
1228 -- At the end of a declarative part, freeze remaining entities
1229 -- declared in it. The end of the visible declarations of package
1230 -- specification is not the end of a declarative part if private
1231 -- declarations are present. The end of a package declaration is a
1232 -- freezing point only if it a library package. A task definition or
1233 -- protected type definition is not a freeze point either. Finally,
1234 -- we do not freeze entities in generic scopes, because there is no
1235 -- code generated for them and freeze nodes will be generated for
1238 -- The end of a package instantiation is not a freeze point, but
1239 -- for now we make it one, because the generic body is inserted
1240 -- (currently) immediately after. Generic instantiations will not
1241 -- be a freeze point once delayed freezing of bodies is implemented.
1242 -- (This is needed in any case for early instantiations ???).
1244 if No (Next_Node) then
1245 if Nkind (Parent (L)) = N_Component_List
1246 or else Nkind (Parent (L)) = N_Task_Definition
1247 or else Nkind (Parent (L)) = N_Protected_Definition
1251 elsif Nkind (Parent (L)) /= N_Package_Specification then
1252 if Nkind (Parent (L)) = N_Package_Body then
1253 Freeze_From := First_Entity (Current_Scope);
1257 Freeze_All (Freeze_From, D);
1258 Freeze_From := Last_Entity (Current_Scope);
1260 elsif Scope (Current_Scope) /= Standard_Standard
1261 and then not Is_Child_Unit (Current_Scope)
1262 and then No (Generic_Parent (Parent (L)))
1266 elsif L /= Visible_Declarations (Parent (L))
1267 or else No (Private_Declarations (Parent (L)))
1268 or else Is_Empty_List (Private_Declarations (Parent (L)))
1271 Freeze_All (Freeze_From, D);
1272 Freeze_From := Last_Entity (Current_Scope);
1275 -- If next node is a body then freeze all types before the body.
1276 -- An exception occurs for expander generated bodies, which can
1277 -- be recognized by their already being analyzed. The expander
1278 -- ensures that all types needed by these bodies have been frozen
1279 -- but it is not necessary to freeze all types (and would be wrong
1280 -- since it would not correspond to an RM defined freeze point).
1282 elsif not Analyzed (Next_Node)
1283 and then (Nkind (Next_Node) = N_Subprogram_Body
1284 or else Nkind (Next_Node) = N_Entry_Body
1285 or else Nkind (Next_Node) = N_Package_Body
1286 or else Nkind (Next_Node) = N_Protected_Body
1287 or else Nkind (Next_Node) = N_Task_Body
1288 or else Nkind (Next_Node) in N_Body_Stub)
1291 Freeze_All (Freeze_From, D);
1292 Freeze_From := Last_Entity (Current_Scope);
1297 end Analyze_Declarations;
1299 ----------------------------------
1300 -- Analyze_Incomplete_Type_Decl --
1301 ----------------------------------
1303 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
1304 F : constant Boolean := Is_Pure (Current_Scope);
1308 Generate_Definition (Defining_Identifier (N));
1310 -- Process an incomplete declaration. The identifier must not have been
1311 -- declared already in the scope. However, an incomplete declaration may
1312 -- appear in the private part of a package, for a private type that has
1313 -- already been declared.
1315 -- In this case, the discriminants (if any) must match
1317 T := Find_Type_Name (N);
1319 Set_Ekind (T, E_Incomplete_Type);
1320 Init_Size_Align (T);
1321 Set_Is_First_Subtype (T, True);
1325 Set_Stored_Constraint (T, No_Elist);
1327 if Present (Discriminant_Specifications (N)) then
1328 Process_Discriminants (N);
1333 -- If the type has discriminants, non-trivial subtypes may be be
1334 -- declared before the full view of the type. The full views of those
1335 -- subtypes will be built after the full view of the type.
1337 Set_Private_Dependents (T, New_Elmt_List);
1339 end Analyze_Incomplete_Type_Decl;
1341 -----------------------------
1342 -- Analyze_Itype_Reference --
1343 -----------------------------
1345 -- Nothing to do. This node is placed in the tree only for the benefit
1346 -- of Gigi processing, and has no effect on the semantic processing.
1348 procedure Analyze_Itype_Reference (N : Node_Id) is
1350 pragma Assert (Is_Itype (Itype (N)));
1352 end Analyze_Itype_Reference;
1354 --------------------------------
1355 -- Analyze_Number_Declaration --
1356 --------------------------------
1358 procedure Analyze_Number_Declaration (N : Node_Id) is
1359 Id : constant Entity_Id := Defining_Identifier (N);
1360 E : constant Node_Id := Expression (N);
1362 Index : Interp_Index;
1366 Generate_Definition (Id);
1369 -- This is an optimization of a common case of an integer literal
1371 if Nkind (E) = N_Integer_Literal then
1372 Set_Is_Static_Expression (E, True);
1373 Set_Etype (E, Universal_Integer);
1375 Set_Etype (Id, Universal_Integer);
1376 Set_Ekind (Id, E_Named_Integer);
1377 Set_Is_Frozen (Id, True);
1381 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1383 -- Process expression, replacing error by integer zero, to avoid
1384 -- cascaded errors or aborts further along in the processing
1386 -- Replace Error by integer zero, which seems least likely to
1387 -- cause cascaded errors.
1390 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
1391 Set_Error_Posted (E);
1396 -- Verify that the expression is static and numeric. If
1397 -- the expression is overloaded, we apply the preference
1398 -- rule that favors root numeric types.
1400 if not Is_Overloaded (E) then
1405 Get_First_Interp (E, Index, It);
1407 while Present (It.Typ) loop
1408 if (Is_Integer_Type (It.Typ)
1409 or else Is_Real_Type (It.Typ))
1410 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
1412 if T = Any_Type then
1415 elsif It.Typ = Universal_Real
1416 or else It.Typ = Universal_Integer
1418 -- Choose universal interpretation over any other
1425 Get_Next_Interp (Index, It);
1429 if Is_Integer_Type (T) then
1431 Set_Etype (Id, Universal_Integer);
1432 Set_Ekind (Id, E_Named_Integer);
1434 elsif Is_Real_Type (T) then
1436 -- Because the real value is converted to universal_real, this
1437 -- is a legal context for a universal fixed expression.
1439 if T = Universal_Fixed then
1441 Loc : constant Source_Ptr := Sloc (N);
1442 Conv : constant Node_Id := Make_Type_Conversion (Loc,
1444 New_Occurrence_Of (Universal_Real, Loc),
1445 Expression => Relocate_Node (E));
1452 elsif T = Any_Fixed then
1453 Error_Msg_N ("illegal context for mixed mode operation", E);
1455 -- Expression is of the form : universal_fixed * integer.
1456 -- Try to resolve as universal_real.
1458 T := Universal_Real;
1463 Set_Etype (Id, Universal_Real);
1464 Set_Ekind (Id, E_Named_Real);
1467 Wrong_Type (E, Any_Numeric);
1471 Set_Ekind (Id, E_Constant);
1472 Set_Never_Set_In_Source (Id, True);
1473 Set_Is_True_Constant (Id, True);
1477 if Nkind (E) = N_Integer_Literal
1478 or else Nkind (E) = N_Real_Literal
1480 Set_Etype (E, Etype (Id));
1483 if not Is_OK_Static_Expression (E) then
1484 Flag_Non_Static_Expr
1485 ("non-static expression used in number declaration!", E);
1486 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
1487 Set_Etype (E, Any_Type);
1489 end Analyze_Number_Declaration;
1491 --------------------------------
1492 -- Analyze_Object_Declaration --
1493 --------------------------------
1495 procedure Analyze_Object_Declaration (N : Node_Id) is
1496 Loc : constant Source_Ptr := Sloc (N);
1497 Id : constant Entity_Id := Defining_Identifier (N);
1501 E : Node_Id := Expression (N);
1502 -- E is set to Expression (N) throughout this routine. When
1503 -- Expression (N) is modified, E is changed accordingly.
1505 Prev_Entity : Entity_Id := Empty;
1507 function Build_Default_Subtype return Entity_Id;
1508 -- If the object is limited or aliased, and if the type is unconstrained
1509 -- and there is no expression, the discriminants cannot be modified and
1510 -- the subtype of the object is constrained by the defaults, so it is
1511 -- worthile building the corresponding subtype.
1513 function Count_Tasks (T : Entity_Id) return Uint;
1514 -- This function is called when a library level object of type is
1515 -- declared. It's function is to count the static number of tasks
1516 -- declared within the type (it is only called if Has_Tasks is set for
1517 -- T). As a side effect, if an array of tasks with non-static bounds or
1518 -- a variant record type is encountered, Check_Restrictions is called
1519 -- indicating the count is unknown.
1521 ---------------------------
1522 -- Build_Default_Subtype --
1523 ---------------------------
1525 function Build_Default_Subtype return Entity_Id is
1526 Constraints : constant List_Id := New_List;
1532 Disc := First_Discriminant (T);
1534 if No (Discriminant_Default_Value (Disc)) then
1535 return T; -- previous error.
1538 Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
1539 while Present (Disc) loop
1542 Discriminant_Default_Value (Disc)), Constraints);
1543 Next_Discriminant (Disc);
1547 Make_Subtype_Declaration (Loc,
1548 Defining_Identifier => Act,
1549 Subtype_Indication =>
1550 Make_Subtype_Indication (Loc,
1551 Subtype_Mark => New_Occurrence_Of (T, Loc),
1553 Make_Index_Or_Discriminant_Constraint
1554 (Loc, Constraints)));
1556 Insert_Before (N, Decl);
1559 end Build_Default_Subtype;
1565 function Count_Tasks (T : Entity_Id) return Uint is
1571 if Is_Task_Type (T) then
1574 elsif Is_Record_Type (T) then
1575 if Has_Discriminants (T) then
1576 Check_Restriction (Max_Tasks, N);
1581 C := First_Component (T);
1582 while Present (C) loop
1583 V := V + Count_Tasks (Etype (C));
1590 elsif Is_Array_Type (T) then
1591 X := First_Index (T);
1592 V := Count_Tasks (Component_Type (T));
1593 while Present (X) loop
1596 if not Is_Static_Subtype (C) then
1597 Check_Restriction (Max_Tasks, N);
1600 V := V * (UI_Max (Uint_0,
1601 Expr_Value (Type_High_Bound (C)) -
1602 Expr_Value (Type_Low_Bound (C)) + Uint_1));
1615 -- Start of processing for Analyze_Object_Declaration
1618 -- There are three kinds of implicit types generated by an
1619 -- object declaration:
1621 -- 1. Those for generated by the original Object Definition
1623 -- 2. Those generated by the Expression
1625 -- 3. Those used to constrained the Object Definition with the
1626 -- expression constraints when it is unconstrained
1628 -- They must be generated in this order to avoid order of elaboration
1629 -- issues. Thus the first step (after entering the name) is to analyze
1630 -- the object definition.
1632 if Constant_Present (N) then
1633 Prev_Entity := Current_Entity_In_Scope (Id);
1635 -- If homograph is an implicit subprogram, it is overridden by the
1636 -- current declaration.
1638 if Present (Prev_Entity)
1639 and then Is_Overloadable (Prev_Entity)
1640 and then Is_Inherited_Operation (Prev_Entity)
1642 Prev_Entity := Empty;
1646 if Present (Prev_Entity) then
1647 Constant_Redeclaration (Id, N, T);
1649 Generate_Reference (Prev_Entity, Id, 'c');
1650 Set_Completion_Referenced (Id);
1652 if Error_Posted (N) then
1654 -- Type mismatch or illegal redeclaration, Do not analyze
1655 -- expression to avoid cascaded errors.
1657 T := Find_Type_Of_Object (Object_Definition (N), N);
1659 Set_Ekind (Id, E_Variable);
1663 -- In the normal case, enter identifier at the start to catch
1664 -- premature usage in the initialization expression.
1667 Generate_Definition (Id);
1670 T := Find_Type_Of_Object (Object_Definition (N), N);
1672 if Error_Posted (Id) then
1674 Set_Ekind (Id, E_Variable);
1679 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
1680 -- out some static checks
1682 if Ada_Version >= Ada_05
1683 and then (Null_Exclusion_Present (N)
1684 or else Can_Never_Be_Null (T))
1686 Set_Can_Never_Be_Null (Id);
1687 Null_Exclusion_Static_Checks (N);
1690 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1692 -- If deferred constant, make sure context is appropriate. We detect
1693 -- a deferred constant as a constant declaration with no expression.
1694 -- A deferred constant can appear in a package body if its completion
1695 -- is by means of an interface pragma.
1697 if Constant_Present (N)
1700 if not Is_Package (Current_Scope) then
1702 ("invalid context for deferred constant declaration ('R'M 7.4)",
1705 ("\declaration requires an initialization expression",
1707 Set_Constant_Present (N, False);
1709 -- In Ada 83, deferred constant must be of private type
1711 elsif not Is_Private_Type (T) then
1712 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1714 ("(Ada 83) deferred constant must be private type", N);
1718 -- If not a deferred constant, then object declaration freezes its type
1721 Check_Fully_Declared (T, N);
1722 Freeze_Before (N, T);
1725 -- If the object was created by a constrained array definition, then
1726 -- set the link in both the anonymous base type and anonymous subtype
1727 -- that are built to represent the array type to point to the object.
1729 if Nkind (Object_Definition (Declaration_Node (Id))) =
1730 N_Constrained_Array_Definition
1732 Set_Related_Array_Object (T, Id);
1733 Set_Related_Array_Object (Base_Type (T), Id);
1736 -- Special checks for protected objects not at library level
1738 if Is_Protected_Type (T)
1739 and then not Is_Library_Level_Entity (Id)
1741 Check_Restriction (No_Local_Protected_Objects, Id);
1743 -- Protected objects with interrupt handlers must be at library level
1745 if Has_Interrupt_Handler (T) then
1747 ("interrupt object can only be declared at library level", Id);
1751 -- The actual subtype of the object is the nominal subtype, unless
1752 -- the nominal one is unconstrained and obtained from the expression.
1756 -- Process initialization expression if present and not in error
1758 if Present (E) and then E /= Error then
1761 -- In case of errors detected in the analysis of the expression,
1762 -- decorate it with the expected type to avoid cascade errors
1764 if not Present (Etype (E)) then
1768 -- If an initialization expression is present, then we set the
1769 -- Is_True_Constant flag. It will be reset if this is a variable
1770 -- and it is indeed modified.
1772 Set_Is_True_Constant (Id, True);
1774 -- If we are analyzing a constant declaration, set its completion
1775 -- flag after analyzing the expression.
1777 if Constant_Present (N) then
1778 Set_Has_Completion (Id);
1781 if not Assignment_OK (N) then
1782 Check_Initialization (T, E);
1785 Set_Etype (Id, T); -- may be overridden later on
1787 Check_Unset_Reference (E);
1789 if Compile_Time_Known_Value (E) then
1790 Set_Current_Value (Id, E);
1793 -- Check incorrect use of dynamically tagged expressions. Note
1794 -- the use of Is_Tagged_Type (T) which seems redundant but is in
1795 -- fact important to avoid spurious errors due to expanded code
1796 -- for dispatching functions over an anonymous access type
1798 if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
1799 and then Is_Tagged_Type (T)
1800 and then not Is_Class_Wide_Type (T)
1802 Error_Msg_N ("dynamically tagged expression not allowed!", E);
1805 Apply_Scalar_Range_Check (E, T);
1806 Apply_Static_Length_Check (E, T);
1809 -- If the No_Streams restriction is set, check that the type of the
1810 -- object is not, and does not contain, any subtype derived from
1811 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
1812 -- Has_Stream just for efficiency reasons. There is no point in
1813 -- spending time on a Has_Stream check if the restriction is not set.
1815 if Restrictions.Set (No_Streams) then
1816 if Has_Stream (T) then
1817 Check_Restriction (No_Streams, N);
1821 -- Abstract type is never permitted for a variable or constant.
1822 -- Note: we inhibit this check for objects that do not come from
1823 -- source because there is at least one case (the expansion of
1824 -- x'class'input where x is abstract) where we legitimately
1825 -- generate an abstract object.
1827 if Is_Abstract (T) and then Comes_From_Source (N) then
1828 Error_Msg_N ("type of object cannot be abstract",
1829 Object_Definition (N));
1831 if Is_CPP_Class (T) then
1832 Error_Msg_NE ("\} may need a cpp_constructor",
1833 Object_Definition (N), T);
1836 -- Case of unconstrained type
1838 elsif Is_Indefinite_Subtype (T) then
1840 -- Nothing to do in deferred constant case
1842 if Constant_Present (N) and then No (E) then
1845 -- Case of no initialization present
1848 if No_Initialization (N) then
1851 elsif Is_Class_Wide_Type (T) then
1853 ("initialization required in class-wide declaration ", N);
1857 ("unconstrained subtype not allowed (need initialization)",
1858 Object_Definition (N));
1861 -- Case of initialization present but in error. Set initial
1862 -- expression as absent (but do not make above complaints)
1864 elsif E = Error then
1865 Set_Expression (N, Empty);
1868 -- Case of initialization present
1871 -- Not allowed in Ada 83
1873 if not Constant_Present (N) then
1874 if Ada_Version = Ada_83
1875 and then Comes_From_Source (Object_Definition (N))
1878 ("(Ada 83) unconstrained variable not allowed",
1879 Object_Definition (N));
1883 -- Now we constrain the variable from the initializing expression
1885 -- If the expression is an aggregate, it has been expanded into
1886 -- individual assignments. Retrieve the actual type from the
1887 -- expanded construct.
1889 if Is_Array_Type (T)
1890 and then No_Initialization (N)
1891 and then Nkind (Original_Node (E)) = N_Aggregate
1896 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
1897 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
1900 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
1902 if Aliased_Present (N) then
1903 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1906 Freeze_Before (N, Act_T);
1907 Freeze_Before (N, T);
1910 elsif Is_Array_Type (T)
1911 and then No_Initialization (N)
1912 and then Nkind (Original_Node (E)) = N_Aggregate
1914 if not Is_Entity_Name (Object_Definition (N)) then
1916 Check_Compile_Time_Size (Act_T);
1918 if Aliased_Present (N) then
1919 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1923 -- When the given object definition and the aggregate are specified
1924 -- independently, and their lengths might differ do a length check.
1925 -- This cannot happen if the aggregate is of the form (others =>...)
1927 if not Is_Constrained (T) then
1930 elsif Nkind (E) = N_Raise_Constraint_Error then
1932 -- Aggregate is statically illegal. Place back in declaration
1934 Set_Expression (N, E);
1935 Set_No_Initialization (N, False);
1937 elsif T = Etype (E) then
1940 elsif Nkind (E) = N_Aggregate
1941 and then Present (Component_Associations (E))
1942 and then Present (Choices (First (Component_Associations (E))))
1943 and then Nkind (First
1944 (Choices (First (Component_Associations (E))))) = N_Others_Choice
1949 Apply_Length_Check (E, T);
1952 elsif (Is_Limited_Record (T)
1953 or else Is_Concurrent_Type (T))
1954 and then not Is_Constrained (T)
1955 and then Has_Discriminants (T)
1957 Act_T := Build_Default_Subtype;
1958 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
1960 elsif not Is_Constrained (T)
1961 and then Has_Discriminants (T)
1962 and then Constant_Present (N)
1963 and then Nkind (E) = N_Function_Call
1965 -- The back-end has problems with constants of a discriminated type
1966 -- with defaults, if the initial value is a function call. We
1967 -- generate an intermediate temporary for the result of the call.
1968 -- It is unclear why this should make it acceptable to gcc. ???
1970 Remove_Side_Effects (E);
1973 if T = Standard_Wide_Character
1974 or else Root_Type (T) = Standard_Wide_String
1976 Check_Restriction (No_Wide_Characters, Object_Definition (N));
1979 -- Now establish the proper kind and type of the object
1981 if Constant_Present (N) then
1982 Set_Ekind (Id, E_Constant);
1983 Set_Never_Set_In_Source (Id, True);
1984 Set_Is_True_Constant (Id, True);
1987 Set_Ekind (Id, E_Variable);
1989 -- A variable is set as shared passive if it appears in a shared
1990 -- passive package, and is at the outer level. This is not done
1991 -- for entities generated during expansion, because those are
1992 -- always manipulated locally.
1994 if Is_Shared_Passive (Current_Scope)
1995 and then Is_Library_Level_Entity (Id)
1996 and then Comes_From_Source (Id)
1998 Set_Is_Shared_Passive (Id);
1999 Check_Shared_Var (Id, T, N);
2002 -- Case of no initializing expression present. If the type is not
2003 -- fully initialized, then we set Never_Set_In_Source, since this
2004 -- is a case of a potentially uninitialized object. Note that we
2005 -- do not consider access variables to be fully initialized for
2006 -- this purpose, since it still seems dubious if someone declares
2008 -- Note that we only do this for source declarations. If the object
2009 -- is declared by a generated declaration, we assume that it is not
2010 -- appropriate to generate warnings in that case.
2013 if (Is_Access_Type (T)
2014 or else not Is_Fully_Initialized_Type (T))
2015 and then Comes_From_Source (N)
2017 Set_Never_Set_In_Source (Id);
2022 Init_Alignment (Id);
2025 if Aliased_Present (N) then
2026 Set_Is_Aliased (Id);
2029 and then Is_Record_Type (T)
2030 and then not Is_Constrained (T)
2031 and then Has_Discriminants (T)
2033 Set_Actual_Subtype (Id, Build_Default_Subtype);
2037 Set_Etype (Id, Act_T);
2039 if Has_Controlled_Component (Etype (Id))
2040 or else Is_Controlled (Etype (Id))
2042 if not Is_Library_Level_Entity (Id) then
2043 Check_Restriction (No_Nested_Finalization, N);
2045 Validate_Controlled_Object (Id);
2048 -- Generate a warning when an initialization causes an obvious
2049 -- ABE violation. If the init expression is a simple aggregate
2050 -- there shouldn't be any initialize/adjust call generated. This
2051 -- will be true as soon as aggregates are built in place when
2052 -- possible. ??? at the moment we do not generate warnings for
2053 -- temporaries created for those aggregates although a
2054 -- Program_Error might be generated if compiled with -gnato
2056 if Is_Controlled (Etype (Id))
2057 and then Comes_From_Source (Id)
2060 BT : constant Entity_Id := Base_Type (Etype (Id));
2062 Implicit_Call : Entity_Id;
2063 pragma Warnings (Off, Implicit_Call);
2064 -- What is this about, it is never referenced ???
2066 function Is_Aggr (N : Node_Id) return Boolean;
2067 -- Check that N is an aggregate
2073 function Is_Aggr (N : Node_Id) return Boolean is
2075 case Nkind (Original_Node (N)) is
2076 when N_Aggregate | N_Extension_Aggregate =>
2079 when N_Qualified_Expression |
2081 N_Unchecked_Type_Conversion =>
2082 return Is_Aggr (Expression (Original_Node (N)));
2090 -- If no underlying type, we already are in an error situation
2091 -- don't try to add a warning since we do not have access
2094 if No (Underlying_Type (BT)) then
2095 Implicit_Call := Empty;
2097 -- A generic type does not have usable primitive operators.
2098 -- Initialization calls are built for instances.
2100 elsif Is_Generic_Type (BT) then
2101 Implicit_Call := Empty;
2103 -- if the init expression is not an aggregate, an adjust
2104 -- call will be generated
2106 elsif Present (E) and then not Is_Aggr (E) then
2107 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
2109 -- if no init expression and we are not in the deferred
2110 -- constant case, an Initialize call will be generated
2112 elsif No (E) and then not Constant_Present (N) then
2113 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
2116 Implicit_Call := Empty;
2122 if Has_Task (Etype (Id)) then
2123 Check_Restriction (No_Tasking, N);
2125 if Is_Library_Level_Entity (Id) then
2126 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
2128 Check_Restriction (Max_Tasks, N);
2129 Check_Restriction (No_Task_Hierarchy, N);
2130 Check_Potentially_Blocking_Operation (N);
2133 -- A rather specialized test. If we see two tasks being declared
2134 -- of the same type in the same object declaration, and the task
2135 -- has an entry with an address clause, we know that program error
2136 -- will be raised at run-time since we can't have two tasks with
2137 -- entries at the same address.
2139 if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
2144 E := First_Entity (Etype (Id));
2145 while Present (E) loop
2146 if Ekind (E) = E_Entry
2147 and then Present (Get_Attribute_Definition_Clause
2148 (E, Attribute_Address))
2151 ("?more than one task with same entry address", N);
2153 ("\?Program_Error will be raised at run time", N);
2155 Make_Raise_Program_Error (Loc,
2156 Reason => PE_Duplicated_Entry_Address));
2166 -- Some simple constant-propagation: if the expression is a constant
2167 -- string initialized with a literal, share the literal. This avoids
2171 and then Is_Entity_Name (E)
2172 and then Ekind (Entity (E)) = E_Constant
2173 and then Base_Type (Etype (E)) = Standard_String
2176 Val : constant Node_Id := Constant_Value (Entity (E));
2179 and then Nkind (Val) = N_String_Literal
2181 Rewrite (E, New_Copy (Val));
2186 -- Another optimization: if the nominal subtype is unconstrained and
2187 -- the expression is a function call that returns an unconstrained
2188 -- type, rewrite the declaration as a renaming of the result of the
2189 -- call. The exceptions below are cases where the copy is expected,
2190 -- either by the back end (Aliased case) or by the semantics, as for
2191 -- initializing controlled types or copying tags for classwide types.
2194 and then Nkind (E) = N_Explicit_Dereference
2195 and then Nkind (Original_Node (E)) = N_Function_Call
2196 and then not Is_Library_Level_Entity (Id)
2197 and then not Is_Constrained (T)
2198 and then not Is_Aliased (Id)
2199 and then not Is_Class_Wide_Type (T)
2200 and then not Is_Controlled (T)
2201 and then not Has_Controlled_Component (Base_Type (T))
2202 and then Expander_Active
2205 Make_Object_Renaming_Declaration (Loc,
2206 Defining_Identifier => Id,
2207 Access_Definition => Empty,
2208 Subtype_Mark => New_Occurrence_Of
2209 (Base_Type (Etype (Id)), Loc),
2212 Set_Renamed_Object (Id, E);
2214 -- Force generation of debugging information for the constant
2215 -- and for the renamed function call.
2217 Set_Needs_Debug_Info (Id);
2218 Set_Needs_Debug_Info (Entity (Prefix (E)));
2221 if Present (Prev_Entity)
2222 and then Is_Frozen (Prev_Entity)
2223 and then not Error_Posted (Id)
2225 Error_Msg_N ("full constant declaration appears too late", N);
2228 Check_Eliminated (Id);
2229 end Analyze_Object_Declaration;
2231 ---------------------------
2232 -- Analyze_Others_Choice --
2233 ---------------------------
2235 -- Nothing to do for the others choice node itself, the semantic analysis
2236 -- of the others choice will occur as part of the processing of the parent
2238 procedure Analyze_Others_Choice (N : Node_Id) is
2239 pragma Warnings (Off, N);
2242 end Analyze_Others_Choice;
2244 --------------------------------
2245 -- Analyze_Per_Use_Expression --
2246 --------------------------------
2248 procedure Analyze_Per_Use_Expression (N : Node_Id; T : Entity_Id) is
2249 Save_In_Default_Expression : constant Boolean := In_Default_Expression;
2251 In_Default_Expression := True;
2252 Pre_Analyze_And_Resolve (N, T);
2253 In_Default_Expression := Save_In_Default_Expression;
2254 end Analyze_Per_Use_Expression;
2256 -------------------------------------------
2257 -- Analyze_Private_Extension_Declaration --
2258 -------------------------------------------
2260 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
2261 T : constant Entity_Id := Defining_Identifier (N);
2262 Indic : constant Node_Id := Subtype_Indication (N);
2263 Parent_Type : Entity_Id;
2264 Parent_Base : Entity_Id;
2267 Generate_Definition (T);
2270 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
2271 Parent_Base := Base_Type (Parent_Type);
2273 if Parent_Type = Any_Type
2274 or else Etype (Parent_Type) = Any_Type
2276 Set_Ekind (T, Ekind (Parent_Type));
2277 Set_Etype (T, Any_Type);
2280 elsif not Is_Tagged_Type (Parent_Type) then
2282 ("parent of type extension must be a tagged type ", Indic);
2285 elsif Ekind (Parent_Type) = E_Void
2286 or else Ekind (Parent_Type) = E_Incomplete_Type
2288 Error_Msg_N ("premature derivation of incomplete type", Indic);
2292 -- Perhaps the parent type should be changed to the class-wide type's
2293 -- specific type in this case to prevent cascading errors ???
2295 if Is_Class_Wide_Type (Parent_Type) then
2297 ("parent of type extension must not be a class-wide type", Indic);
2301 if (not Is_Package (Current_Scope)
2302 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
2303 or else In_Private_Part (Current_Scope)
2306 Error_Msg_N ("invalid context for private extension", N);
2309 -- Set common attributes
2311 Set_Is_Pure (T, Is_Pure (Current_Scope));
2312 Set_Scope (T, Current_Scope);
2313 Set_Ekind (T, E_Record_Type_With_Private);
2314 Init_Size_Align (T);
2316 Set_Etype (T, Parent_Base);
2317 Set_Has_Task (T, Has_Task (Parent_Base));
2319 Set_Convention (T, Convention (Parent_Type));
2320 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
2321 Set_Is_First_Subtype (T);
2322 Make_Class_Wide_Type (T);
2324 if Unknown_Discriminants_Present (N) then
2325 Set_Discriminant_Constraint (T, No_Elist);
2328 Build_Derived_Record_Type (N, Parent_Type, T);
2329 end Analyze_Private_Extension_Declaration;
2331 ---------------------------------
2332 -- Analyze_Subtype_Declaration --
2333 ---------------------------------
2335 procedure Analyze_Subtype_Declaration (N : Node_Id) is
2336 Id : constant Entity_Id := Defining_Identifier (N);
2338 R_Checks : Check_Result;
2341 Generate_Definition (Id);
2342 Set_Is_Pure (Id, Is_Pure (Current_Scope));
2343 Init_Size_Align (Id);
2345 -- The following guard condition on Enter_Name is to handle cases
2346 -- where the defining identifier has already been entered into the
2347 -- scope but the declaration as a whole needs to be analyzed.
2349 -- This case in particular happens for derived enumeration types. The
2350 -- derived enumeration type is processed as an inserted enumeration
2351 -- type declaration followed by a rewritten subtype declaration. The
2352 -- defining identifier, however, is entered into the name scope very
2353 -- early in the processing of the original type declaration and
2354 -- therefore needs to be avoided here, when the created subtype
2355 -- declaration is analyzed. (See Build_Derived_Types)
2357 -- This also happens when the full view of a private type is derived
2358 -- type with constraints. In this case the entity has been introduced
2359 -- in the private declaration.
2361 if Present (Etype (Id))
2362 and then (Is_Private_Type (Etype (Id))
2363 or else Is_Task_Type (Etype (Id))
2364 or else Is_Rewrite_Substitution (N))
2372 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
2374 -- Inherit common attributes
2376 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
2377 Set_Is_Volatile (Id, Is_Volatile (T));
2378 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
2379 Set_Is_Atomic (Id, Is_Atomic (T));
2381 -- In the case where there is no constraint given in the subtype
2382 -- indication, Process_Subtype just returns the Subtype_Mark,
2383 -- so its semantic attributes must be established here.
2385 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
2386 Set_Etype (Id, Base_Type (T));
2390 Set_Ekind (Id, E_Array_Subtype);
2391 Copy_Array_Subtype_Attributes (Id, T);
2393 when Decimal_Fixed_Point_Kind =>
2394 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
2395 Set_Digits_Value (Id, Digits_Value (T));
2396 Set_Delta_Value (Id, Delta_Value (T));
2397 Set_Scale_Value (Id, Scale_Value (T));
2398 Set_Small_Value (Id, Small_Value (T));
2399 Set_Scalar_Range (Id, Scalar_Range (T));
2400 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
2401 Set_Is_Constrained (Id, Is_Constrained (T));
2402 Set_RM_Size (Id, RM_Size (T));
2404 when Enumeration_Kind =>
2405 Set_Ekind (Id, E_Enumeration_Subtype);
2406 Set_First_Literal (Id, First_Literal (Base_Type (T)));
2407 Set_Scalar_Range (Id, Scalar_Range (T));
2408 Set_Is_Character_Type (Id, Is_Character_Type (T));
2409 Set_Is_Constrained (Id, Is_Constrained (T));
2410 Set_RM_Size (Id, RM_Size (T));
2412 when Ordinary_Fixed_Point_Kind =>
2413 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
2414 Set_Scalar_Range (Id, Scalar_Range (T));
2415 Set_Small_Value (Id, Small_Value (T));
2416 Set_Delta_Value (Id, Delta_Value (T));
2417 Set_Is_Constrained (Id, Is_Constrained (T));
2418 Set_RM_Size (Id, RM_Size (T));
2421 Set_Ekind (Id, E_Floating_Point_Subtype);
2422 Set_Scalar_Range (Id, Scalar_Range (T));
2423 Set_Digits_Value (Id, Digits_Value (T));
2424 Set_Is_Constrained (Id, Is_Constrained (T));
2426 when Signed_Integer_Kind =>
2427 Set_Ekind (Id, E_Signed_Integer_Subtype);
2428 Set_Scalar_Range (Id, Scalar_Range (T));
2429 Set_Is_Constrained (Id, Is_Constrained (T));
2430 Set_RM_Size (Id, RM_Size (T));
2432 when Modular_Integer_Kind =>
2433 Set_Ekind (Id, E_Modular_Integer_Subtype);
2434 Set_Scalar_Range (Id, Scalar_Range (T));
2435 Set_Is_Constrained (Id, Is_Constrained (T));
2436 Set_RM_Size (Id, RM_Size (T));
2438 when Class_Wide_Kind =>
2439 Set_Ekind (Id, E_Class_Wide_Subtype);
2440 Set_First_Entity (Id, First_Entity (T));
2441 Set_Last_Entity (Id, Last_Entity (T));
2442 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2443 Set_Cloned_Subtype (Id, T);
2444 Set_Is_Tagged_Type (Id, True);
2445 Set_Has_Unknown_Discriminants
2448 if Ekind (T) = E_Class_Wide_Subtype then
2449 Set_Equivalent_Type (Id, Equivalent_Type (T));
2452 when E_Record_Type | E_Record_Subtype =>
2453 Set_Ekind (Id, E_Record_Subtype);
2455 if Ekind (T) = E_Record_Subtype
2456 and then Present (Cloned_Subtype (T))
2458 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
2460 Set_Cloned_Subtype (Id, T);
2463 Set_First_Entity (Id, First_Entity (T));
2464 Set_Last_Entity (Id, Last_Entity (T));
2465 Set_Has_Discriminants (Id, Has_Discriminants (T));
2466 Set_Is_Constrained (Id, Is_Constrained (T));
2467 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2468 Set_Has_Unknown_Discriminants
2469 (Id, Has_Unknown_Discriminants (T));
2471 if Has_Discriminants (T) then
2472 Set_Discriminant_Constraint
2473 (Id, Discriminant_Constraint (T));
2474 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2476 elsif Has_Unknown_Discriminants (Id) then
2477 Set_Discriminant_Constraint (Id, No_Elist);
2480 if Is_Tagged_Type (T) then
2481 Set_Is_Tagged_Type (Id);
2482 Set_Is_Abstract (Id, Is_Abstract (T));
2483 Set_Primitive_Operations
2484 (Id, Primitive_Operations (T));
2485 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2488 when Private_Kind =>
2489 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2490 Set_Has_Discriminants (Id, Has_Discriminants (T));
2491 Set_Is_Constrained (Id, Is_Constrained (T));
2492 Set_First_Entity (Id, First_Entity (T));
2493 Set_Last_Entity (Id, Last_Entity (T));
2494 Set_Private_Dependents (Id, New_Elmt_List);
2495 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2496 Set_Has_Unknown_Discriminants
2497 (Id, Has_Unknown_Discriminants (T));
2499 if Is_Tagged_Type (T) then
2500 Set_Is_Tagged_Type (Id);
2501 Set_Is_Abstract (Id, Is_Abstract (T));
2502 Set_Primitive_Operations
2503 (Id, Primitive_Operations (T));
2504 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2507 -- In general the attributes of the subtype of a private
2508 -- type are the attributes of the partial view of parent.
2509 -- However, the full view may be a discriminated type,
2510 -- and the subtype must share the discriminant constraint
2511 -- to generate correct calls to initialization procedures.
2513 if Has_Discriminants (T) then
2514 Set_Discriminant_Constraint
2515 (Id, Discriminant_Constraint (T));
2516 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2518 elsif Present (Full_View (T))
2519 and then Has_Discriminants (Full_View (T))
2521 Set_Discriminant_Constraint
2522 (Id, Discriminant_Constraint (Full_View (T)));
2523 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2525 -- This would seem semantically correct, but apparently
2526 -- confuses the back-end (4412-009). To be explained ???
2528 -- Set_Has_Discriminants (Id);
2531 Prepare_Private_Subtype_Completion (Id, N);
2534 Set_Ekind (Id, E_Access_Subtype);
2535 Set_Is_Constrained (Id, Is_Constrained (T));
2536 Set_Is_Access_Constant
2537 (Id, Is_Access_Constant (T));
2538 Set_Directly_Designated_Type
2539 (Id, Designated_Type (T));
2541 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
2542 -- and carry out some static checks
2544 if Null_Exclusion_Present (N)
2545 or else Can_Never_Be_Null (T)
2547 Set_Can_Never_Be_Null (Id);
2549 if Null_Exclusion_Present (N)
2550 and then Can_Never_Be_Null (T)
2553 ("(Ada 2005) null exclusion not allowed if parent "
2554 & "is already non-null", Subtype_Indication (N));
2558 -- A Pure library_item must not contain the declaration of a
2559 -- named access type, except within a subprogram, generic
2560 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
2562 if Comes_From_Source (Id)
2563 and then In_Pure_Unit
2564 and then not In_Subprogram_Task_Protected_Unit
2567 ("named access types not allowed in pure unit", N);
2570 when Concurrent_Kind =>
2571 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2572 Set_Corresponding_Record_Type (Id,
2573 Corresponding_Record_Type (T));
2574 Set_First_Entity (Id, First_Entity (T));
2575 Set_First_Private_Entity (Id, First_Private_Entity (T));
2576 Set_Has_Discriminants (Id, Has_Discriminants (T));
2577 Set_Is_Constrained (Id, Is_Constrained (T));
2578 Set_Last_Entity (Id, Last_Entity (T));
2580 if Has_Discriminants (T) then
2581 Set_Discriminant_Constraint (Id,
2582 Discriminant_Constraint (T));
2583 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2586 -- If the subtype name denotes an incomplete type
2587 -- an error was already reported by Process_Subtype.
2589 when E_Incomplete_Type =>
2590 Set_Etype (Id, Any_Type);
2593 raise Program_Error;
2597 if Etype (Id) = Any_Type then
2601 -- Some common processing on all types
2603 Set_Size_Info (Id, T);
2604 Set_First_Rep_Item (Id, First_Rep_Item (T));
2608 Set_Is_Immediately_Visible (Id, True);
2609 Set_Depends_On_Private (Id, Has_Private_Component (T));
2611 if Present (Generic_Parent_Type (N))
2614 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
2616 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
2617 /= N_Formal_Private_Type_Definition)
2619 if Is_Tagged_Type (Id) then
2620 if Is_Class_Wide_Type (Id) then
2621 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
2623 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
2626 elsif Scope (Etype (Id)) /= Standard_Standard then
2627 Derive_Subprograms (Generic_Parent_Type (N), Id);
2631 if Is_Private_Type (T)
2632 and then Present (Full_View (T))
2634 Conditional_Delay (Id, Full_View (T));
2636 -- The subtypes of components or subcomponents of protected types
2637 -- do not need freeze nodes, which would otherwise appear in the
2638 -- wrong scope (before the freeze node for the protected type). The
2639 -- proper subtypes are those of the subcomponents of the corresponding
2642 elsif Ekind (Scope (Id)) /= E_Protected_Type
2643 and then Present (Scope (Scope (Id))) -- error defense!
2644 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
2646 Conditional_Delay (Id, T);
2649 -- Check that constraint_error is raised for a scalar subtype
2650 -- indication when the lower or upper bound of a non-null range
2651 -- lies outside the range of the type mark.
2653 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
2654 if Is_Scalar_Type (Etype (Id))
2655 and then Scalar_Range (Id) /=
2656 Scalar_Range (Etype (Subtype_Mark
2657 (Subtype_Indication (N))))
2661 Etype (Subtype_Mark (Subtype_Indication (N))));
2663 elsif Is_Array_Type (Etype (Id))
2664 and then Present (First_Index (Id))
2666 -- This really should be a subprogram that finds the indications
2669 if ((Nkind (First_Index (Id)) = N_Identifier
2670 and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
2671 or else Nkind (First_Index (Id)) = N_Subtype_Indication)
2673 Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
2676 Target_Typ : constant Entity_Id :=
2679 (Subtype_Mark (Subtype_Indication (N)))));
2683 (Scalar_Range (Etype (First_Index (Id))),
2685 Etype (First_Index (Id)),
2686 Defining_Identifier (N));
2692 Sloc (Defining_Identifier (N)));
2698 Check_Eliminated (Id);
2699 end Analyze_Subtype_Declaration;
2701 --------------------------------
2702 -- Analyze_Subtype_Indication --
2703 --------------------------------
2705 procedure Analyze_Subtype_Indication (N : Node_Id) is
2706 T : constant Entity_Id := Subtype_Mark (N);
2707 R : constant Node_Id := Range_Expression (Constraint (N));
2714 Set_Etype (N, Etype (R));
2716 Set_Error_Posted (R);
2717 Set_Error_Posted (T);
2719 end Analyze_Subtype_Indication;
2721 ------------------------------
2722 -- Analyze_Type_Declaration --
2723 ------------------------------
2725 procedure Analyze_Type_Declaration (N : Node_Id) is
2726 Def : constant Node_Id := Type_Definition (N);
2727 Def_Id : constant Entity_Id := Defining_Identifier (N);
2731 Is_Remote : constant Boolean :=
2732 (Is_Remote_Types (Current_Scope)
2733 or else Is_Remote_Call_Interface (Current_Scope))
2734 and then not (In_Private_Part (Current_Scope)
2736 In_Package_Body (Current_Scope));
2739 Prev := Find_Type_Name (N);
2741 -- The full view, if present, now points to the current type
2743 -- Ada 2005 (AI-50217): If the type was previously decorated when
2744 -- imported through a LIMITED WITH clause, it appears as incomplete
2745 -- but has no full view.
2747 if Ekind (Prev) = E_Incomplete_Type
2748 and then Present (Full_View (Prev))
2750 T := Full_View (Prev);
2755 Set_Is_Pure (T, Is_Pure (Current_Scope));
2757 -- We set the flag Is_First_Subtype here. It is needed to set the
2758 -- corresponding flag for the Implicit class-wide-type created
2759 -- during tagged types processing.
2761 Set_Is_First_Subtype (T, True);
2763 -- Only composite types other than array types are allowed to have
2768 -- For derived types, the rule will be checked once we've figured
2769 -- out the parent type.
2771 when N_Derived_Type_Definition =>
2774 -- For record types, discriminants are allowed
2776 when N_Record_Definition =>
2780 if Present (Discriminant_Specifications (N)) then
2782 ("elementary or array type cannot have discriminants",
2784 (First (Discriminant_Specifications (N))));
2788 -- Elaborate the type definition according to kind, and generate
2789 -- subsidiary (implicit) subtypes where needed. We skip this if
2790 -- it was already done (this happens during the reanalysis that
2791 -- follows a call to the high level optimizer).
2793 if not Analyzed (T) then
2798 when N_Access_To_Subprogram_Definition =>
2799 Access_Subprogram_Declaration (T, Def);
2801 -- If this is a remote access to subprogram, we must create
2802 -- the equivalent fat pointer type, and related subprograms.
2805 Process_Remote_AST_Declaration (N);
2808 -- Validate categorization rule against access type declaration
2809 -- usually a violation in Pure unit, Shared_Passive unit.
2811 Validate_Access_Type_Declaration (T, N);
2813 when N_Access_To_Object_Definition =>
2814 Access_Type_Declaration (T, Def);
2816 -- Validate categorization rule against access type declaration
2817 -- usually a violation in Pure unit, Shared_Passive unit.
2819 Validate_Access_Type_Declaration (T, N);
2821 -- If we are in a Remote_Call_Interface package and define
2822 -- a RACW, Read and Write attribute must be added.
2825 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2827 Add_RACW_Features (Def_Id);
2830 -- Set no strict aliasing flag if config pragma seen
2832 if Opt.No_Strict_Aliasing then
2833 Set_No_Strict_Aliasing (Base_Type (Def_Id));
2836 when N_Array_Type_Definition =>
2837 Array_Type_Declaration (T, Def);
2839 when N_Derived_Type_Definition =>
2840 Derived_Type_Declaration (T, N, T /= Def_Id);
2842 when N_Enumeration_Type_Definition =>
2843 Enumeration_Type_Declaration (T, Def);
2845 when N_Floating_Point_Definition =>
2846 Floating_Point_Type_Declaration (T, Def);
2848 when N_Decimal_Fixed_Point_Definition =>
2849 Decimal_Fixed_Point_Type_Declaration (T, Def);
2851 when N_Ordinary_Fixed_Point_Definition =>
2852 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2854 when N_Signed_Integer_Type_Definition =>
2855 Signed_Integer_Type_Declaration (T, Def);
2857 when N_Modular_Type_Definition =>
2858 Modular_Type_Declaration (T, Def);
2860 when N_Record_Definition =>
2861 Record_Type_Declaration (T, N, Prev);
2864 raise Program_Error;
2869 if Etype (T) = Any_Type then
2873 -- Some common processing for all types
2875 Set_Depends_On_Private (T, Has_Private_Component (T));
2877 -- Both the declared entity, and its anonymous base type if one
2878 -- was created, need freeze nodes allocated.
2881 B : constant Entity_Id := Base_Type (T);
2884 -- In the case where the base type is different from the first
2885 -- subtype, we pre-allocate a freeze node, and set the proper link
2886 -- to the first subtype. Freeze_Entity will use this preallocated
2887 -- freeze node when it freezes the entity.
2890 Ensure_Freeze_Node (B);
2891 Set_First_Subtype_Link (Freeze_Node (B), T);
2894 if not From_With_Type (T) then
2895 Set_Has_Delayed_Freeze (T);
2899 -- Case of T is the full declaration of some private type which has
2900 -- been swapped in Defining_Identifier (N).
2902 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2903 Process_Full_View (N, T, Def_Id);
2905 -- Record the reference. The form of this is a little strange,
2906 -- since the full declaration has been swapped in. So the first
2907 -- parameter here represents the entity to which a reference is
2908 -- made which is the "real" entity, i.e. the one swapped in,
2909 -- and the second parameter provides the reference location.
2911 Generate_Reference (T, T, 'c');
2912 Set_Completion_Referenced (Def_Id);
2914 -- For completion of incomplete type, process incomplete dependents
2915 -- and always mark the full type as referenced (it is the incomplete
2916 -- type that we get for any real reference).
2918 elsif Ekind (Prev) = E_Incomplete_Type then
2919 Process_Incomplete_Dependents (N, T, Prev);
2920 Generate_Reference (Prev, Def_Id, 'c');
2921 Set_Completion_Referenced (Def_Id);
2923 -- If not private type or incomplete type completion, this is a real
2924 -- definition of a new entity, so record it.
2927 Generate_Definition (Def_Id);
2930 Check_Eliminated (Def_Id);
2931 end Analyze_Type_Declaration;
2933 --------------------------
2934 -- Analyze_Variant_Part --
2935 --------------------------
2937 procedure Analyze_Variant_Part (N : Node_Id) is
2939 procedure Non_Static_Choice_Error (Choice : Node_Id);
2940 -- Error routine invoked by the generic instantiation below when
2941 -- the variant part has a non static choice.
2943 procedure Process_Declarations (Variant : Node_Id);
2944 -- Analyzes all the declarations associated with a Variant.
2945 -- Needed by the generic instantiation below.
2947 package Variant_Choices_Processing is new
2948 Generic_Choices_Processing
2949 (Get_Alternatives => Variants,
2950 Get_Choices => Discrete_Choices,
2951 Process_Empty_Choice => No_OP,
2952 Process_Non_Static_Choice => Non_Static_Choice_Error,
2953 Process_Associated_Node => Process_Declarations);
2954 use Variant_Choices_Processing;
2955 -- Instantiation of the generic choice processing package
2957 -----------------------------
2958 -- Non_Static_Choice_Error --
2959 -----------------------------
2961 procedure Non_Static_Choice_Error (Choice : Node_Id) is
2963 Flag_Non_Static_Expr
2964 ("choice given in variant part is not static!", Choice);
2965 end Non_Static_Choice_Error;
2967 --------------------------
2968 -- Process_Declarations --
2969 --------------------------
2971 procedure Process_Declarations (Variant : Node_Id) is
2973 if not Null_Present (Component_List (Variant)) then
2974 Analyze_Declarations (Component_Items (Component_List (Variant)));
2976 if Present (Variant_Part (Component_List (Variant))) then
2977 Analyze (Variant_Part (Component_List (Variant)));
2980 end Process_Declarations;
2982 -- Variables local to Analyze_Case_Statement
2984 Discr_Name : Node_Id;
2985 Discr_Type : Entity_Id;
2987 Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
2989 Dont_Care : Boolean;
2990 Others_Present : Boolean := False;
2992 -- Start of processing for Analyze_Variant_Part
2995 Discr_Name := Name (N);
2996 Analyze (Discr_Name);
2998 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
2999 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
3002 Discr_Type := Etype (Entity (Discr_Name));
3004 if not Is_Discrete_Type (Discr_Type) then
3006 ("discriminant in a variant part must be of a discrete type",
3011 -- Call the instantiated Analyze_Choices which does the rest of the work
3014 (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
3015 end Analyze_Variant_Part;
3017 ----------------------------
3018 -- Array_Type_Declaration --
3019 ----------------------------
3021 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
3022 Component_Def : constant Node_Id := Component_Definition (Def);
3023 Element_Type : Entity_Id;
3024 Implicit_Base : Entity_Id;
3026 Related_Id : Entity_Id := Empty;
3028 P : constant Node_Id := Parent (Def);
3032 if Nkind (Def) = N_Constrained_Array_Definition then
3033 Index := First (Discrete_Subtype_Definitions (Def));
3035 Index := First (Subtype_Marks (Def));
3038 -- Find proper names for the implicit types which may be public.
3039 -- in case of anonymous arrays we use the name of the first object
3040 -- of that type as prefix.
3043 Related_Id := Defining_Identifier (P);
3049 while Present (Index) loop
3051 Make_Index (Index, P, Related_Id, Nb_Index);
3053 Nb_Index := Nb_Index + 1;
3056 if Present (Subtype_Indication (Component_Def)) then
3057 Element_Type := Process_Subtype (Subtype_Indication (Component_Def),
3058 P, Related_Id, 'C');
3060 -- Ada 2005 (AI-230): Access Definition case
3062 else pragma Assert (Present (Access_Definition (Component_Def)));
3063 Element_Type := Access_Definition
3064 (Related_Nod => Related_Id,
3065 N => Access_Definition (Component_Def));
3067 -- Ada 2005 (AI-230): In case of components that are anonymous
3068 -- access types the level of accessibility depends on the enclosing
3071 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
3073 -- Ada 2005 (AI-254)
3076 CD : constant Node_Id :=
3077 Access_To_Subprogram_Definition
3078 (Access_Definition (Component_Def));
3080 if Present (CD) and then Protected_Present (CD) then
3082 Replace_Anonymous_Access_To_Protected_Subprogram
3083 (Def, Element_Type);
3088 -- Constrained array case
3091 T := Create_Itype (E_Void, P, Related_Id, 'T');
3094 if Nkind (Def) = N_Constrained_Array_Definition then
3096 -- Establish Implicit_Base as unconstrained base type
3098 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
3100 Init_Size_Align (Implicit_Base);
3101 Set_Etype (Implicit_Base, Implicit_Base);
3102 Set_Scope (Implicit_Base, Current_Scope);
3103 Set_Has_Delayed_Freeze (Implicit_Base);
3105 -- The constrained array type is a subtype of the unconstrained one
3107 Set_Ekind (T, E_Array_Subtype);
3108 Init_Size_Align (T);
3109 Set_Etype (T, Implicit_Base);
3110 Set_Scope (T, Current_Scope);
3111 Set_Is_Constrained (T, True);
3112 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
3113 Set_Has_Delayed_Freeze (T);
3115 -- Complete setup of implicit base type
3117 Set_First_Index (Implicit_Base, First_Index (T));
3118 Set_Component_Type (Implicit_Base, Element_Type);
3119 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
3120 Set_Component_Size (Implicit_Base, Uint_0);
3121 Set_Has_Controlled_Component
3122 (Implicit_Base, Has_Controlled_Component
3125 Is_Controlled (Element_Type));
3126 Set_Finalize_Storage_Only
3127 (Implicit_Base, Finalize_Storage_Only
3130 -- Unconstrained array case
3133 Set_Ekind (T, E_Array_Type);
3134 Init_Size_Align (T);
3136 Set_Scope (T, Current_Scope);
3137 Set_Component_Size (T, Uint_0);
3138 Set_Is_Constrained (T, False);
3139 Set_First_Index (T, First (Subtype_Marks (Def)));
3140 Set_Has_Delayed_Freeze (T, True);
3141 Set_Has_Task (T, Has_Task (Element_Type));
3142 Set_Has_Controlled_Component (T, Has_Controlled_Component
3145 Is_Controlled (Element_Type));
3146 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
3150 Set_Component_Type (Base_Type (T), Element_Type);
3152 if Aliased_Present (Component_Definition (Def)) then
3153 Set_Has_Aliased_Components (Etype (T));
3156 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
3157 -- array to ensure that objects of this type are initialized.
3159 if Ada_Version >= Ada_05
3160 and then (Null_Exclusion_Present (Component_Definition (Def))
3161 or else Can_Never_Be_Null (Element_Type))
3163 Set_Can_Never_Be_Null (T);
3165 if Null_Exclusion_Present (Component_Definition (Def))
3166 and then Can_Never_Be_Null (Element_Type)
3169 ("(Ada 2005) already a null-excluding type",
3170 Subtype_Indication (Component_Definition (Def)));
3174 Priv := Private_Component (Element_Type);
3176 if Present (Priv) then
3178 -- Check for circular definitions
3180 if Priv = Any_Type then
3181 Set_Component_Type (Etype (T), Any_Type);
3183 -- There is a gap in the visibility of operations on the composite
3184 -- type only if the component type is defined in a different scope.
3186 elsif Scope (Priv) = Current_Scope then
3189 elsif Is_Limited_Type (Priv) then
3190 Set_Is_Limited_Composite (Etype (T));
3191 Set_Is_Limited_Composite (T);
3193 Set_Is_Private_Composite (Etype (T));
3194 Set_Is_Private_Composite (T);
3198 -- Create a concatenation operator for the new type. Internal
3199 -- array types created for packed entities do not need such, they
3200 -- are compatible with the user-defined type.
3202 if Number_Dimensions (T) = 1
3203 and then not Is_Packed_Array_Type (T)
3205 New_Concatenation_Op (T);
3208 -- In the case of an unconstrained array the parser has already
3209 -- verified that all the indices are unconstrained but we still
3210 -- need to make sure that the element type is constrained.
3212 if Is_Indefinite_Subtype (Element_Type) then
3214 ("unconstrained element type in array declaration",
3215 Subtype_Indication (Component_Def));
3217 elsif Is_Abstract (Element_Type) then
3219 ("The type of a component cannot be abstract",
3220 Subtype_Indication (Component_Def));
3223 end Array_Type_Declaration;
3225 ------------------------------------------------------
3226 -- Replace_Anonymous_Access_To_Protected_Subprogram --
3227 ------------------------------------------------------
3229 function Replace_Anonymous_Access_To_Protected_Subprogram
3231 Prev_E : Entity_Id) return Entity_Id
3233 Loc : constant Source_Ptr := Sloc (N);
3235 Curr_Scope : constant Scope_Stack_Entry :=
3236 Scope_Stack.Table (Scope_Stack.Last);
3238 Anon : constant Entity_Id :=
3239 Make_Defining_Identifier (Loc,
3240 Chars => New_Internal_Name ('S'));
3245 P : Node_Id := Parent (N);
3248 Set_Is_Internal (Anon);
3251 when N_Component_Declaration |
3252 N_Unconstrained_Array_Definition |
3253 N_Constrained_Array_Definition =>
3254 Comp := Component_Definition (N);
3255 Acc := Access_Definition (Component_Definition (N));
3257 when N_Discriminant_Specification =>
3258 Comp := Discriminant_Type (N);
3259 Acc := Discriminant_Type (N);
3261 when N_Parameter_Specification =>
3262 Comp := Parameter_Type (N);
3263 Acc := Parameter_Type (N);
3266 raise Program_Error;
3269 Decl := Make_Full_Type_Declaration (Loc,
3270 Defining_Identifier => Anon,
3272 Copy_Separate_Tree (Access_To_Subprogram_Definition (Acc)));
3274 Mark_Rewrite_Insertion (Decl);
3276 -- Insert the new declaration in the nearest enclosing scope
3278 while Present (P) and then not Has_Declarations (P) loop
3282 pragma Assert (Present (P));
3284 if Nkind (P) = N_Package_Specification then
3285 Prepend (Decl, Visible_Declarations (P));
3287 Prepend (Decl, Declarations (P));
3290 -- Replace the anonymous type with an occurrence of the new declaration.
3291 -- In all cases the rewriten node does not have the null-exclusion
3292 -- attribute because (if present) it was already inherited by the
3293 -- anonymous entity (Anon). Thus, in case of components we do not
3294 -- inherit this attribute.
3296 if Nkind (N) = N_Parameter_Specification then
3297 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
3298 Set_Etype (Defining_Identifier (N), Anon);
3299 Set_Null_Exclusion_Present (N, False);
3302 Make_Component_Definition (Loc,
3303 Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
3306 Mark_Rewrite_Insertion (Comp);
3308 -- Temporarily remove the current scope from the stack to add the new
3309 -- declarations to the enclosing scope
3311 Scope_Stack.Decrement_Last;
3313 Scope_Stack.Append (Curr_Scope);
3315 Set_Original_Access_Type (Anon, Prev_E);
3317 end Replace_Anonymous_Access_To_Protected_Subprogram;
3319 -------------------------------
3320 -- Build_Derived_Access_Type --
3321 -------------------------------
3323 procedure Build_Derived_Access_Type
3325 Parent_Type : Entity_Id;
3326 Derived_Type : Entity_Id)
3328 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
3330 Desig_Type : Entity_Id;
3332 Discr_Con_Elist : Elist_Id;
3333 Discr_Con_El : Elmt_Id;
3337 -- Set the designated type so it is available in case this is
3338 -- an access to a self-referential type, e.g. a standard list
3339 -- type with a next pointer. Will be reset after subtype is built.
3341 Set_Directly_Designated_Type
3342 (Derived_Type, Designated_Type (Parent_Type));
3344 Subt := Process_Subtype (S, N);
3346 if Nkind (S) /= N_Subtype_Indication
3347 and then Subt /= Base_Type (Subt)
3349 Set_Ekind (Derived_Type, E_Access_Subtype);
3352 if Ekind (Derived_Type) = E_Access_Subtype then
3354 Pbase : constant Entity_Id := Base_Type (Parent_Type);
3355 Ibase : constant Entity_Id :=
3356 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
3357 Svg_Chars : constant Name_Id := Chars (Ibase);
3358 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
3361 Copy_Node (Pbase, Ibase);
3363 Set_Chars (Ibase, Svg_Chars);
3364 Set_Next_Entity (Ibase, Svg_Next_E);
3365 Set_Sloc (Ibase, Sloc (Derived_Type));
3366 Set_Scope (Ibase, Scope (Derived_Type));
3367 Set_Freeze_Node (Ibase, Empty);
3368 Set_Is_Frozen (Ibase, False);
3369 Set_Comes_From_Source (Ibase, False);
3370 Set_Is_First_Subtype (Ibase, False);
3372 Set_Etype (Ibase, Pbase);
3373 Set_Etype (Derived_Type, Ibase);
3377 Set_Directly_Designated_Type
3378 (Derived_Type, Designated_Type (Subt));
3380 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
3381 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
3382 Set_Size_Info (Derived_Type, Parent_Type);
3383 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
3384 Set_Depends_On_Private (Derived_Type,
3385 Has_Private_Component (Derived_Type));
3386 Conditional_Delay (Derived_Type, Subt);
3388 -- Ada 2005 (AI-231). Set the null-exclusion attribute
3390 if Null_Exclusion_Present (Type_Definition (N))
3391 or else Can_Never_Be_Null (Parent_Type)
3393 Set_Can_Never_Be_Null (Derived_Type);
3396 -- Note: we do not copy the Storage_Size_Variable, since
3397 -- we always go to the root type for this information.
3399 -- Apply range checks to discriminants for derived record case
3400 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
3402 Desig_Type := Designated_Type (Derived_Type);
3403 if Is_Composite_Type (Desig_Type)
3404 and then (not Is_Array_Type (Desig_Type))
3405 and then Has_Discriminants (Desig_Type)
3406 and then Base_Type (Desig_Type) /= Desig_Type
3408 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
3409 Discr_Con_El := First_Elmt (Discr_Con_Elist);
3411 Discr := First_Discriminant (Base_Type (Desig_Type));
3412 while Present (Discr_Con_El) loop
3413 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
3414 Next_Elmt (Discr_Con_El);
3415 Next_Discriminant (Discr);
3418 end Build_Derived_Access_Type;
3420 ------------------------------
3421 -- Build_Derived_Array_Type --
3422 ------------------------------
3424 procedure Build_Derived_Array_Type
3426 Parent_Type : Entity_Id;
3427 Derived_Type : Entity_Id)
3429 Loc : constant Source_Ptr := Sloc (N);
3430 Tdef : constant Node_Id := Type_Definition (N);
3431 Indic : constant Node_Id := Subtype_Indication (Tdef);
3432 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3433 Implicit_Base : Entity_Id;
3434 New_Indic : Node_Id;
3436 procedure Make_Implicit_Base;
3437 -- If the parent subtype is constrained, the derived type is a
3438 -- subtype of an implicit base type derived from the parent base.
3440 ------------------------
3441 -- Make_Implicit_Base --
3442 ------------------------
3444 procedure Make_Implicit_Base is
3447 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3449 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3450 Set_Etype (Implicit_Base, Parent_Base);
3452 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
3453 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
3455 Set_Has_Delayed_Freeze (Implicit_Base, True);
3456 end Make_Implicit_Base;
3458 -- Start of processing for Build_Derived_Array_Type
3461 if not Is_Constrained (Parent_Type) then
3462 if Nkind (Indic) /= N_Subtype_Indication then
3463 Set_Ekind (Derived_Type, E_Array_Type);
3465 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
3466 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
3468 Set_Has_Delayed_Freeze (Derived_Type, True);
3472 Set_Etype (Derived_Type, Implicit_Base);
3475 Make_Subtype_Declaration (Loc,
3476 Defining_Identifier => Derived_Type,
3477 Subtype_Indication =>
3478 Make_Subtype_Indication (Loc,
3479 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
3480 Constraint => Constraint (Indic)));
3482 Rewrite (N, New_Indic);
3487 if Nkind (Indic) /= N_Subtype_Indication then
3490 Set_Ekind (Derived_Type, Ekind (Parent_Type));
3491 Set_Etype (Derived_Type, Implicit_Base);
3492 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
3495 Error_Msg_N ("illegal constraint on constrained type", Indic);
3499 -- If the parent type is not a derived type itself, and is
3500 -- declared in a closed scope (e.g., a subprogram), then we
3501 -- need to explicitly introduce the new type's concatenation
3502 -- operator since Derive_Subprograms will not inherit the
3503 -- parent's operator. If the parent type is unconstrained, the
3504 -- operator is of the unconstrained base type.
3506 if Number_Dimensions (Parent_Type) = 1
3507 and then not Is_Limited_Type (Parent_Type)
3508 and then not Is_Derived_Type (Parent_Type)
3509 and then not Is_Package (Scope (Base_Type (Parent_Type)))
3511 if not Is_Constrained (Parent_Type)
3512 and then Is_Constrained (Derived_Type)
3514 New_Concatenation_Op (Implicit_Base);
3516 New_Concatenation_Op (Derived_Type);
3519 end Build_Derived_Array_Type;
3521 -----------------------------------
3522 -- Build_Derived_Concurrent_Type --
3523 -----------------------------------
3525 procedure Build_Derived_Concurrent_Type
3527 Parent_Type : Entity_Id;
3528 Derived_Type : Entity_Id)
3530 D_Constraint : Node_Id;
3531 Disc_Spec : Node_Id;
3532 Old_Disc : Entity_Id;
3533 New_Disc : Entity_Id;
3535 Constraint_Present : constant Boolean :=
3536 Nkind (Subtype_Indication (Type_Definition (N)))
3537 = N_Subtype_Indication;
3540 Set_Stored_Constraint (Derived_Type, No_Elist);
3542 if Is_Task_Type (Parent_Type) then
3543 Set_Storage_Size_Variable (Derived_Type,
3544 Storage_Size_Variable (Parent_Type));
3547 if Present (Discriminant_Specifications (N)) then
3548 New_Scope (Derived_Type);
3549 Check_Or_Process_Discriminants (N, Derived_Type);
3552 elsif Constraint_Present then
3554 -- Build constrained subtype and derive from it
3557 Loc : constant Source_Ptr := Sloc (N);
3558 Anon : constant Entity_Id :=
3559 Make_Defining_Identifier (Loc,
3560 New_External_Name (Chars (Derived_Type), 'T'));
3565 Make_Subtype_Declaration (Loc,
3566 Defining_Identifier => Anon,
3567 Subtype_Indication =>
3568 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
3569 Insert_Before (N, Decl);
3570 Rewrite (Subtype_Indication (Type_Definition (N)),
3571 New_Occurrence_Of (Anon, Loc));
3573 Set_Analyzed (Derived_Type, False);
3579 -- All attributes are inherited from parent. In particular,
3580 -- entries and the corresponding record type are the same.
3581 -- Discriminants may be renamed, and must be treated separately.
3583 Set_Has_Discriminants
3584 (Derived_Type, Has_Discriminants (Parent_Type));
3585 Set_Corresponding_Record_Type
3586 (Derived_Type, Corresponding_Record_Type (Parent_Type));
3588 if Constraint_Present then
3589 if not Has_Discriminants (Parent_Type) then
3590 Error_Msg_N ("untagged parent must have discriminants", N);
3592 elsif Present (Discriminant_Specifications (N)) then
3594 -- Verify that new discriminants are used to constrain
3597 Old_Disc := First_Discriminant (Parent_Type);
3598 New_Disc := First_Discriminant (Derived_Type);
3599 Disc_Spec := First (Discriminant_Specifications (N));
3603 (Constraint (Subtype_Indication (Type_Definition (N)))));
3605 while Present (Old_Disc) and then Present (Disc_Spec) loop
3607 if Nkind (Discriminant_Type (Disc_Spec)) /=
3610 Analyze (Discriminant_Type (Disc_Spec));
3612 if not Subtypes_Statically_Compatible (
3613 Etype (Discriminant_Type (Disc_Spec)),
3617 ("not statically compatible with parent discriminant",
3618 Discriminant_Type (Disc_Spec));
3622 if Nkind (D_Constraint) = N_Identifier
3623 and then Chars (D_Constraint) /=
3624 Chars (Defining_Identifier (Disc_Spec))
3626 Error_Msg_N ("new discriminants must constrain old ones",
3629 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
3632 Next_Discriminant (Old_Disc);
3633 Next_Discriminant (New_Disc);
3637 if Present (Old_Disc) or else Present (Disc_Spec) then
3638 Error_Msg_N ("discriminant mismatch in derivation", N);
3643 elsif Present (Discriminant_Specifications (N)) then
3645 ("missing discriminant constraint in untagged derivation",
3649 if Present (Discriminant_Specifications (N)) then
3650 Old_Disc := First_Discriminant (Parent_Type);
3651 while Present (Old_Disc) loop
3653 if No (Next_Entity (Old_Disc))
3654 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
3656 Set_Next_Entity (Last_Entity (Derived_Type),
3657 Next_Entity (Old_Disc));
3661 Next_Discriminant (Old_Disc);
3665 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
3666 if Has_Discriminants (Parent_Type) then
3667 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3668 Set_Discriminant_Constraint (
3669 Derived_Type, Discriminant_Constraint (Parent_Type));
3673 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
3675 Set_Has_Completion (Derived_Type);
3676 end Build_Derived_Concurrent_Type;
3678 ------------------------------------
3679 -- Build_Derived_Enumeration_Type --
3680 ------------------------------------
3682 procedure Build_Derived_Enumeration_Type
3684 Parent_Type : Entity_Id;
3685 Derived_Type : Entity_Id)
3687 Loc : constant Source_Ptr := Sloc (N);
3688 Def : constant Node_Id := Type_Definition (N);
3689 Indic : constant Node_Id := Subtype_Indication (Def);
3690 Implicit_Base : Entity_Id;
3691 Literal : Entity_Id;
3692 New_Lit : Entity_Id;
3693 Literals_List : List_Id;
3694 Type_Decl : Node_Id;
3696 Rang_Expr : Node_Id;
3699 -- Since types Standard.Character and Standard.Wide_Character do
3700 -- not have explicit literals lists we need to process types derived
3701 -- from them specially. This is handled by Derived_Standard_Character.
3702 -- If the parent type is a generic type, there are no literals either,
3703 -- and we construct the same skeletal representation as for the generic
3706 if Root_Type (Parent_Type) = Standard_Character
3707 or else Root_Type (Parent_Type) = Standard_Wide_Character
3709 Derived_Standard_Character (N, Parent_Type, Derived_Type);
3711 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
3718 Make_Attribute_Reference (Loc,
3719 Attribute_Name => Name_First,
3720 Prefix => New_Reference_To (Derived_Type, Loc));
3721 Set_Etype (Lo, Derived_Type);
3724 Make_Attribute_Reference (Loc,
3725 Attribute_Name => Name_Last,
3726 Prefix => New_Reference_To (Derived_Type, Loc));
3727 Set_Etype (Hi, Derived_Type);
3729 Set_Scalar_Range (Derived_Type,
3736 -- If a constraint is present, analyze the bounds to catch
3737 -- premature usage of the derived literals.
3739 if Nkind (Indic) = N_Subtype_Indication
3740 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
3742 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
3743 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
3746 -- Introduce an implicit base type for the derived type even
3747 -- if there is no constraint attached to it, since this seems
3748 -- closer to the Ada semantics. Build a full type declaration
3749 -- tree for the derived type using the implicit base type as
3750 -- the defining identifier. The build a subtype declaration
3751 -- tree which applies the constraint (if any) have it replace
3752 -- the derived type declaration.
3754 Literal := First_Literal (Parent_Type);
3755 Literals_List := New_List;
3757 while Present (Literal)
3758 and then Ekind (Literal) = E_Enumeration_Literal
3760 -- Literals of the derived type have the same representation as
3761 -- those of the parent type, but this representation can be
3762 -- overridden by an explicit representation clause. Indicate
3763 -- that there is no explicit representation given yet. These
3764 -- derived literals are implicit operations of the new type,
3765 -- and can be overriden by explicit ones.
3767 if Nkind (Literal) = N_Defining_Character_Literal then
3769 Make_Defining_Character_Literal (Loc, Chars (Literal));
3771 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
3774 Set_Ekind (New_Lit, E_Enumeration_Literal);
3775 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
3776 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
3777 Set_Enumeration_Rep_Expr (New_Lit, Empty);
3778 Set_Alias (New_Lit, Literal);
3779 Set_Is_Known_Valid (New_Lit, True);
3781 Append (New_Lit, Literals_List);
3782 Next_Literal (Literal);
3786 Make_Defining_Identifier (Sloc (Derived_Type),
3787 New_External_Name (Chars (Derived_Type), 'B'));
3789 -- Indicate the proper nature of the derived type. This must
3790 -- be done before analysis of the literals, to recognize cases
3791 -- when a literal may be hidden by a previous explicit function
3792 -- definition (cf. c83031a).
3794 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
3795 Set_Etype (Derived_Type, Implicit_Base);
3798 Make_Full_Type_Declaration (Loc,
3799 Defining_Identifier => Implicit_Base,
3800 Discriminant_Specifications => No_List,
3802 Make_Enumeration_Type_Definition (Loc, Literals_List));
3804 Mark_Rewrite_Insertion (Type_Decl);
3805 Insert_Before (N, Type_Decl);
3806 Analyze (Type_Decl);
3808 -- After the implicit base is analyzed its Etype needs to be changed
3809 -- to reflect the fact that it is derived from the parent type which
3810 -- was ignored during analysis. We also set the size at this point.
3812 Set_Etype (Implicit_Base, Parent_Type);
3814 Set_Size_Info (Implicit_Base, Parent_Type);
3815 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
3816 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
3818 Set_Has_Non_Standard_Rep
3819 (Implicit_Base, Has_Non_Standard_Rep
3821 Set_Has_Delayed_Freeze (Implicit_Base);
3823 -- Process the subtype indication including a validation check
3824 -- on the constraint, if any. If a constraint is given, its bounds
3825 -- must be implicitly converted to the new type.
3827 if Nkind (Indic) = N_Subtype_Indication then
3829 R : constant Node_Id :=
3830 Range_Expression (Constraint (Indic));
3833 if Nkind (R) = N_Range then
3834 Hi := Build_Scalar_Bound
3835 (High_Bound (R), Parent_Type, Implicit_Base);
3836 Lo := Build_Scalar_Bound
3837 (Low_Bound (R), Parent_Type, Implicit_Base);
3840 -- Constraint is a Range attribute. Replace with the
3841 -- explicit mention of the bounds of the prefix, which must
3844 Analyze (Prefix (R));
3846 Convert_To (Implicit_Base,
3847 Make_Attribute_Reference (Loc,
3848 Attribute_Name => Name_Last,
3850 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3853 Convert_To (Implicit_Base,
3854 Make_Attribute_Reference (Loc,
3855 Attribute_Name => Name_First,
3857 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3864 (Type_High_Bound (Parent_Type),
3865 Parent_Type, Implicit_Base);
3868 (Type_Low_Bound (Parent_Type),
3869 Parent_Type, Implicit_Base);
3877 -- If we constructed a default range for the case where no range
3878 -- was given, then the expressions in the range must not freeze
3879 -- since they do not correspond to expressions in the source.
3881 if Nkind (Indic) /= N_Subtype_Indication then
3882 Set_Must_Not_Freeze (Lo);
3883 Set_Must_Not_Freeze (Hi);
3884 Set_Must_Not_Freeze (Rang_Expr);
3888 Make_Subtype_Declaration (Loc,
3889 Defining_Identifier => Derived_Type,
3890 Subtype_Indication =>
3891 Make_Subtype_Indication (Loc,
3892 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
3894 Make_Range_Constraint (Loc,
3895 Range_Expression => Rang_Expr))));
3899 -- If pragma Discard_Names applies on the first subtype of the
3900 -- parent type, then it must be applied on this subtype as well.
3902 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
3903 Set_Discard_Names (Derived_Type);
3906 -- Apply a range check. Since this range expression doesn't have an
3907 -- Etype, we have to specifically pass the Source_Typ parameter. Is
3910 if Nkind (Indic) = N_Subtype_Indication then
3911 Apply_Range_Check (Range_Expression (Constraint (Indic)),
3913 Source_Typ => Entity (Subtype_Mark (Indic)));
3916 end Build_Derived_Enumeration_Type;
3918 --------------------------------
3919 -- Build_Derived_Numeric_Type --
3920 --------------------------------
3922 procedure Build_Derived_Numeric_Type
3924 Parent_Type : Entity_Id;
3925 Derived_Type : Entity_Id)
3927 Loc : constant Source_Ptr := Sloc (N);
3928 Tdef : constant Node_Id := Type_Definition (N);
3929 Indic : constant Node_Id := Subtype_Indication (Tdef);
3930 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3931 No_Constraint : constant Boolean := Nkind (Indic) /=
3932 N_Subtype_Indication;
3933 Implicit_Base : Entity_Id;
3939 -- Process the subtype indication including a validation check on
3940 -- the constraint if any.
3942 Discard_Node (Process_Subtype (Indic, N));
3944 -- Introduce an implicit base type for the derived type even if there
3945 -- is no constraint attached to it, since this seems closer to the Ada
3949 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3951 Set_Etype (Implicit_Base, Parent_Base);
3952 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3953 Set_Size_Info (Implicit_Base, Parent_Base);
3954 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3955 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
3956 Set_Parent (Implicit_Base, Parent (Derived_Type));
3958 if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
3959 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3962 Set_Has_Delayed_Freeze (Implicit_Base);
3964 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
3965 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
3967 Set_Scalar_Range (Implicit_Base,
3972 if Has_Infinities (Parent_Base) then
3973 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
3976 -- The Derived_Type, which is the entity of the declaration, is a
3977 -- subtype of the implicit base. Its Ekind is a subtype, even in the
3978 -- absence of an explicit constraint.
3980 Set_Etype (Derived_Type, Implicit_Base);
3982 -- If we did not have a constraint, then the Ekind is set from the
3983 -- parent type (otherwise Process_Subtype has set the bounds)
3985 if No_Constraint then
3986 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
3989 -- If we did not have a range constraint, then set the range from the
3990 -- parent type. Otherwise, the call to Process_Subtype has set the
3994 or else not Has_Range_Constraint (Indic)
3996 Set_Scalar_Range (Derived_Type,
3998 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
3999 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
4000 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
4002 if Has_Infinities (Parent_Type) then
4003 Set_Includes_Infinities (Scalar_Range (Derived_Type));
4007 -- Set remaining type-specific fields, depending on numeric type
4009 if Is_Modular_Integer_Type (Parent_Type) then
4010 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
4012 Set_Non_Binary_Modulus
4013 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
4015 elsif Is_Floating_Point_Type (Parent_Type) then
4017 -- Digits of base type is always copied from the digits value of
4018 -- the parent base type, but the digits of the derived type will
4019 -- already have been set if there was a constraint present.
4021 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
4022 Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
4024 if No_Constraint then
4025 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
4028 elsif Is_Fixed_Point_Type (Parent_Type) then
4030 -- Small of base type and derived type are always copied from the
4031 -- parent base type, since smalls never change. The delta of the
4032 -- base type is also copied from the parent base type. However the
4033 -- delta of the derived type will have been set already if a
4034 -- constraint was present.
4036 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
4037 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
4038 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
4040 if No_Constraint then
4041 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
4044 -- The scale and machine radix in the decimal case are always
4045 -- copied from the parent base type.
4047 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
4048 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
4049 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
4051 Set_Machine_Radix_10
4052 (Derived_Type, Machine_Radix_10 (Parent_Base));
4053 Set_Machine_Radix_10
4054 (Implicit_Base, Machine_Radix_10 (Parent_Base));
4056 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
4058 if No_Constraint then
4059 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
4062 -- the analysis of the subtype_indication sets the
4063 -- digits value of the derived type.
4070 -- The type of the bounds is that of the parent type, and they
4071 -- must be converted to the derived type.
4073 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
4075 -- The implicit_base should be frozen when the derived type is frozen,
4076 -- but note that it is used in the conversions of the bounds. For fixed
4077 -- types we delay the determination of the bounds until the proper
4078 -- freezing point. For other numeric types this is rejected by GCC, for
4079 -- reasons that are currently unclear (???), so we choose to freeze the
4080 -- implicit base now. In the case of integers and floating point types
4081 -- this is harmless because subsequent representation clauses cannot
4082 -- affect anything, but it is still baffling that we cannot use the
4083 -- same mechanism for all derived numeric types.
4085 if Is_Fixed_Point_Type (Parent_Type) then
4086 Conditional_Delay (Implicit_Base, Parent_Type);
4088 Freeze_Before (N, Implicit_Base);
4090 end Build_Derived_Numeric_Type;
4092 --------------------------------
4093 -- Build_Derived_Private_Type --
4094 --------------------------------
4096 procedure Build_Derived_Private_Type
4098 Parent_Type : Entity_Id;
4099 Derived_Type : Entity_Id;
4100 Is_Completion : Boolean;
4101 Derive_Subps : Boolean := True)
4103 Der_Base : Entity_Id;
4105 Full_Decl : Node_Id := Empty;
4106 Full_Der : Entity_Id;
4108 Last_Discr : Entity_Id;
4109 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
4110 Swapped : Boolean := False;
4112 procedure Copy_And_Build;
4113 -- Copy derived type declaration, replace parent with its full view,
4114 -- and analyze new declaration.
4116 --------------------
4117 -- Copy_And_Build --
4118 --------------------
4120 procedure Copy_And_Build is
4124 if Ekind (Parent_Type) in Record_Kind
4125 or else (Ekind (Parent_Type) in Enumeration_Kind
4126 and then Root_Type (Parent_Type) /= Standard_Character
4127 and then Root_Type (Parent_Type) /= Standard_Wide_Character
4128 and then not Is_Generic_Type (Root_Type (Parent_Type)))
4130 Full_N := New_Copy_Tree (N);
4131 Insert_After (N, Full_N);
4132 Build_Derived_Type (
4133 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
4136 Build_Derived_Type (
4137 N, Parent_Type, Full_Der, True, Derive_Subps => False);
4141 -- Start of processing for Build_Derived_Private_Type
4144 if Is_Tagged_Type (Parent_Type) then
4145 Build_Derived_Record_Type
4146 (N, Parent_Type, Derived_Type, Derive_Subps);
4149 elsif Has_Discriminants (Parent_Type) then
4150 if Present (Full_View (Parent_Type)) then
4151 if not Is_Completion then
4153 -- Copy declaration for subsequent analysis, to provide a
4154 -- completion for what is a private declaration. Indicate that
4155 -- the full type is internally generated.
4157 Full_Decl := New_Copy_Tree (N);
4158 Full_Der := New_Copy (Derived_Type);
4159 Set_Comes_From_Source (Full_Decl, False);
4161 Insert_After (N, Full_Decl);
4164 -- If this is a completion, the full view being built is
4165 -- itself private. We build a subtype of the parent with
4166 -- the same constraints as this full view, to convey to the
4167 -- back end the constrained components and the size of this
4168 -- subtype. If the parent is constrained, its full view can
4169 -- serve as the underlying full view of the derived type.
4171 if No (Discriminant_Specifications (N)) then
4172 if Nkind (Subtype_Indication (Type_Definition (N))) =
4173 N_Subtype_Indication
4175 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
4177 elsif Is_Constrained (Full_View (Parent_Type)) then
4178 Set_Underlying_Full_View (Derived_Type,
4179 Full_View (Parent_Type));
4183 -- If there are new discriminants, the parent subtype is
4184 -- constrained by them, but it is not clear how to build
4185 -- the underlying_full_view in this case ???
4192 -- Build partial view of derived type from partial view of parent
4194 Build_Derived_Record_Type
4195 (N, Parent_Type, Derived_Type, Derive_Subps);
4197 if Present (Full_View (Parent_Type))
4198 and then not Is_Completion
4200 if not In_Open_Scopes (Par_Scope)
4201 or else not In_Same_Source_Unit (N, Parent_Type)
4203 -- Swap partial and full views temporarily
4205 Install_Private_Declarations (Par_Scope);
4206 Install_Visible_Declarations (Par_Scope);
4210 -- Build full view of derived type from full view of parent which
4211 -- is now installed. Subprograms have been derived on the partial
4212 -- view, the completion does not derive them anew.
4214 if not Is_Tagged_Type (Parent_Type) then
4215 Build_Derived_Record_Type
4216 (Full_Decl, Parent_Type, Full_Der, False);
4219 -- If full view of parent is tagged, the completion
4220 -- inherits the proper primitive operations.
4222 Set_Defining_Identifier (Full_Decl, Full_Der);
4223 Build_Derived_Record_Type
4224 (Full_Decl, Parent_Type, Full_Der, Derive_Subps);
4225 Set_Analyzed (Full_Decl);
4229 Uninstall_Declarations (Par_Scope);
4231 if In_Open_Scopes (Par_Scope) then
4232 Install_Visible_Declarations (Par_Scope);
4236 Der_Base := Base_Type (Derived_Type);
4237 Set_Full_View (Derived_Type, Full_Der);
4238 Set_Full_View (Der_Base, Base_Type (Full_Der));
4240 -- Copy the discriminant list from full view to the partial views
4241 -- (base type and its subtype). Gigi requires that the partial
4242 -- and full views have the same discriminants.
4244 -- Note that since the partial view is pointing to discriminants
4245 -- in the full view, their scope will be that of the full view.
4246 -- This might cause some front end problems and need
4249 Discr := First_Discriminant (Base_Type (Full_Der));
4250 Set_First_Entity (Der_Base, Discr);
4253 Last_Discr := Discr;
4254 Next_Discriminant (Discr);
4255 exit when No (Discr);
4258 Set_Last_Entity (Der_Base, Last_Discr);
4260 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
4261 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
4262 Set_Stored_Constraint (Full_Der, Stored_Constraint (Derived_Type));
4265 -- If this is a completion, the derived type stays private
4266 -- and there is no need to create a further full view, except
4267 -- in the unusual case when the derivation is nested within a
4268 -- child unit, see below.
4273 elsif Present (Full_View (Parent_Type))
4274 and then Has_Discriminants (Full_View (Parent_Type))
4276 if Has_Unknown_Discriminants (Parent_Type)
4277 and then Nkind (Subtype_Indication (Type_Definition (N)))
4278 = N_Subtype_Indication
4281 ("cannot constrain type with unknown discriminants",
4282 Subtype_Indication (Type_Definition (N)));
4286 -- If full view of parent is a record type, Build full view as
4287 -- a derivation from the parent's full view. Partial view remains
4288 -- private. For code generation and linking, the full view must
4289 -- have the same public status as the partial one. This full view
4290 -- is only needed if the parent type is in an enclosing scope, so
4291 -- that the full view may actually become visible, e.g. in a child
4292 -- unit. This is both more efficient, and avoids order of freezing
4293 -- problems with the added entities.
4295 if not Is_Private_Type (Full_View (Parent_Type))
4296 and then (In_Open_Scopes (Scope (Parent_Type)))
4298 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
4299 Chars (Derived_Type));
4300 Set_Is_Itype (Full_Der);
4301 Set_Has_Private_Declaration (Full_Der);
4302 Set_Has_Private_Declaration (Derived_Type);
4303 Set_Associated_Node_For_Itype (Full_Der, N);
4304 Set_Parent (Full_Der, Parent (Derived_Type));
4305 Set_Full_View (Derived_Type, Full_Der);
4306 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
4307 Full_P := Full_View (Parent_Type);
4308 Exchange_Declarations (Parent_Type);
4310 Exchange_Declarations (Full_P);
4313 Build_Derived_Record_Type
4314 (N, Full_View (Parent_Type), Derived_Type,
4315 Derive_Subps => False);
4318 -- In any case, the primitive operations are inherited from
4319 -- the parent type, not from the internal full view.
4321 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
4323 if Derive_Subps then
4324 Derive_Subprograms (Parent_Type, Derived_Type);
4328 -- Untagged type, No discriminants on either view
4330 if Nkind (Subtype_Indication (Type_Definition (N))) =
4331 N_Subtype_Indication
4334 ("illegal constraint on type without discriminants", N);
4337 if Present (Discriminant_Specifications (N))
4338 and then Present (Full_View (Parent_Type))
4339 and then not Is_Tagged_Type (Full_View (Parent_Type))
4342 ("cannot add discriminants to untagged type", N);
4345 Set_Stored_Constraint (Derived_Type, No_Elist);
4346 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
4347 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
4348 Set_Has_Controlled_Component
4349 (Derived_Type, Has_Controlled_Component
4352 -- Direct controlled types do not inherit Finalize_Storage_Only flag
4354 if not Is_Controlled (Parent_Type) then
4355 Set_Finalize_Storage_Only
4356 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
4359 -- Construct the implicit full view by deriving from full view of
4360 -- the parent type. In order to get proper visibility, we install
4361 -- the parent scope and its declarations.
4363 -- ??? if the parent is untagged private and its completion is
4364 -- tagged, this mechanism will not work because we cannot derive
4365 -- from the tagged full view unless we have an extension
4367 if Present (Full_View (Parent_Type))
4368 and then not Is_Tagged_Type (Full_View (Parent_Type))
4369 and then not Is_Completion
4372 Make_Defining_Identifier (Sloc (Derived_Type),
4373 Chars => Chars (Derived_Type));
4374 Set_Is_Itype (Full_Der);
4375 Set_Has_Private_Declaration (Full_Der);
4376 Set_Has_Private_Declaration (Derived_Type);
4377 Set_Associated_Node_For_Itype (Full_Der, N);
4378 Set_Parent (Full_Der, Parent (Derived_Type));
4379 Set_Full_View (Derived_Type, Full_Der);
4381 if not In_Open_Scopes (Par_Scope) then
4382 Install_Private_Declarations (Par_Scope);
4383 Install_Visible_Declarations (Par_Scope);
4385 Uninstall_Declarations (Par_Scope);
4387 -- If parent scope is open and in another unit, and parent has a
4388 -- completion, then the derivation is taking place in the visible
4389 -- part of a child unit. In that case retrieve the full view of
4390 -- the parent momentarily.
4392 elsif not In_Same_Source_Unit (N, Parent_Type) then
4393 Full_P := Full_View (Parent_Type);
4394 Exchange_Declarations (Parent_Type);
4396 Exchange_Declarations (Full_P);
4398 -- Otherwise it is a local derivation
4404 Set_Scope (Full_Der, Current_Scope);
4405 Set_Is_First_Subtype (Full_Der,
4406 Is_First_Subtype (Derived_Type));
4407 Set_Has_Size_Clause (Full_Der, False);
4408 Set_Has_Alignment_Clause (Full_Der, False);
4409 Set_Next_Entity (Full_Der, Empty);
4410 Set_Has_Delayed_Freeze (Full_Der);
4411 Set_Is_Frozen (Full_Der, False);
4412 Set_Freeze_Node (Full_Der, Empty);
4413 Set_Depends_On_Private (Full_Der,
4414 Has_Private_Component (Full_Der));
4415 Set_Public_Status (Full_Der);
4419 Set_Has_Unknown_Discriminants (Derived_Type,
4420 Has_Unknown_Discriminants (Parent_Type));
4422 if Is_Private_Type (Derived_Type) then
4423 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4426 if Is_Private_Type (Parent_Type)
4427 and then Base_Type (Parent_Type) = Parent_Type
4428 and then In_Open_Scopes (Scope (Parent_Type))
4430 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
4432 if Is_Child_Unit (Scope (Current_Scope))
4433 and then Is_Completion
4434 and then In_Private_Part (Current_Scope)
4435 and then Scope (Parent_Type) /= Current_Scope
4437 -- This is the unusual case where a type completed by a private
4438 -- derivation occurs within a package nested in a child unit,
4439 -- and the parent is declared in an ancestor. In this case, the
4440 -- full view of the parent type will become visible in the body
4441 -- of the enclosing child, and only then will the current type
4442 -- be possibly non-private. We build a underlying full view that
4443 -- will be installed when the enclosing child body is compiled.
4446 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
4450 Make_Defining_Identifier (Sloc (Derived_Type),
4451 Chars (Derived_Type));
4452 Set_Is_Itype (Full_Der);
4453 Set_Itype (IR, Full_Der);
4454 Insert_After (N, IR);
4456 -- The full view will be used to swap entities on entry/exit
4457 -- to the body, and must appear in the entity list for the
4460 Append_Entity (Full_Der, Scope (Derived_Type));
4461 Set_Has_Private_Declaration (Full_Der);
4462 Set_Has_Private_Declaration (Derived_Type);
4463 Set_Associated_Node_For_Itype (Full_Der, N);
4464 Set_Parent (Full_Der, Parent (Derived_Type));
4465 Full_P := Full_View (Parent_Type);
4466 Exchange_Declarations (Parent_Type);
4468 Exchange_Declarations (Full_P);
4469 Set_Underlying_Full_View (Derived_Type, Full_Der);
4473 end Build_Derived_Private_Type;
4475 -------------------------------
4476 -- Build_Derived_Record_Type --
4477 -------------------------------
4481 -- Ideally we would like to use the same model of type derivation for
4482 -- tagged and untagged record types. Unfortunately this is not quite
4483 -- possible because the semantics of representation clauses is different
4484 -- for tagged and untagged records under inheritance. Consider the
4487 -- type R (...) is [tagged] record ... end record;
4488 -- type T (...) is new R (...) [with ...];
4490 -- The representation clauses of T can specify a completely different
4491 -- record layout from R's. Hence the same component can be placed in
4492 -- two very different positions in objects of type T and R. If R and T
4493 -- are tagged types, representation clauses for T can only specify the
4494 -- layout of non inherited components, thus components that are common
4495 -- in R and T have the same position in objects of type R and T.
4497 -- This has two implications. The first is that the entire tree for R's
4498 -- declaration needs to be copied for T in the untagged case, so that T
4499 -- can be viewed as a record type of its own with its own representation
4500 -- clauses. The second implication is the way we handle discriminants.
4501 -- Specifically, in the untagged case we need a way to communicate to Gigi
4502 -- what are the real discriminants in the record, while for the semantics
4503 -- we need to consider those introduced by the user to rename the
4504 -- discriminants in the parent type. This is handled by introducing the
4505 -- notion of stored discriminants. See below for more.
4507 -- Fortunately the way regular components are inherited can be handled in
4508 -- the same way in tagged and untagged types.
4510 -- To complicate things a bit more the private view of a private extension
4511 -- cannot be handled in the same way as the full view (for one thing the
4512 -- semantic rules are somewhat different). We will explain what differs
4515 -- 2. DISCRIMINANTS UNDER INHERITANCE
4517 -- The semantic rules governing the discriminants of derived types are
4520 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
4521 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
4523 -- If parent type has discriminants, then the discriminants that are
4524 -- declared in the derived type are [3.4 (11)]:
4526 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
4529 -- o Otherwise, each discriminant of the parent type (implicitly declared
4530 -- in the same order with the same specifications). In this case, the
4531 -- discriminants are said to be "inherited", or if unknown in the parent
4532 -- are also unknown in the derived type.
4534 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
4536 -- o The parent subtype shall be constrained;
4538 -- o If the parent type is not a tagged type, then each discriminant of
4539 -- the derived type shall be used in the constraint defining a parent
4540 -- subtype [Implementation note: this ensures that the new discriminant
4541 -- can share storage with an existing discriminant.].
4543 -- For the derived type each discriminant of the parent type is either
4544 -- inherited, constrained to equal some new discriminant of the derived
4545 -- type, or constrained to the value of an expression.
4547 -- When inherited or constrained to equal some new discriminant, the
4548 -- parent discriminant and the discriminant of the derived type are said
4551 -- If a discriminant of the parent type is constrained to a specific value
4552 -- in the derived type definition, then the discriminant is said to be
4553 -- "specified" by that derived type definition.
4555 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
4557 -- We have spoken about stored discriminants in point 1 (introduction)
4558 -- above. There are two sort of stored discriminants: implicit and
4559 -- explicit. As long as the derived type inherits the same discriminants as
4560 -- the root record type, stored discriminants are the same as regular
4561 -- discriminants, and are said to be implicit. However, if any discriminant
4562 -- in the root type was renamed in the derived type, then the derived
4563 -- type will contain explicit stored discriminants. Explicit stored
4564 -- discriminants are discriminants in addition to the semantically visible
4565 -- discriminants defined for the derived type. Stored discriminants are
4566 -- used by Gigi to figure out what are the physical discriminants in
4567 -- objects of the derived type (see precise definition in einfo.ads).
4568 -- As an example, consider the following:
4570 -- type R (D1, D2, D3 : Int) is record ... end record;
4571 -- type T1 is new R;
4572 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
4573 -- type T3 is new T2;
4574 -- type T4 (Y : Int) is new T3 (Y, 99);
4576 -- The following table summarizes the discriminants and stored
4577 -- discriminants in R and T1 through T4.
4579 -- Type Discrim Stored Discrim Comment
4580 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
4581 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
4582 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
4583 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
4584 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
4586 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to
4587 -- find the corresponding discriminant in the parent type, while
4588 -- Original_Record_Component (abbreviated ORC below), the actual physical
4589 -- component that is renamed. Finally the field Is_Completely_Hidden
4590 -- (abbreviated ICH below) is set for all explicit stored discriminants
4591 -- (see einfo.ads for more info). For the above example this gives:
4593 -- Discrim CD ORC ICH
4594 -- ^^^^^^^ ^^ ^^^ ^^^
4595 -- D1 in R empty itself no
4596 -- D2 in R empty itself no
4597 -- D3 in R empty itself no
4599 -- D1 in T1 D1 in R itself no
4600 -- D2 in T1 D2 in R itself no
4601 -- D3 in T1 D3 in R itself no
4603 -- X1 in T2 D3 in T1 D3 in T2 no
4604 -- X2 in T2 D1 in T1 D1 in T2 no
4605 -- D1 in T2 empty itself yes
4606 -- D2 in T2 empty itself yes
4607 -- D3 in T2 empty itself yes
4609 -- X1 in T3 X1 in T2 D3 in T3 no
4610 -- X2 in T3 X2 in T2 D1 in T3 no
4611 -- D1 in T3 empty itself yes
4612 -- D2 in T3 empty itself yes
4613 -- D3 in T3 empty itself yes
4615 -- Y in T4 X1 in T3 D3 in T3 no
4616 -- D1 in T3 empty itself yes
4617 -- D2 in T3 empty itself yes
4618 -- D3 in T3 empty itself yes
4620 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
4622 -- Type derivation for tagged types is fairly straightforward. if no
4623 -- discriminants are specified by the derived type, these are inherited
4624 -- from the parent. No explicit stored discriminants are ever necessary.
4625 -- The only manipulation that is done to the tree is that of adding a
4626 -- _parent field with parent type and constrained to the same constraint
4627 -- specified for the parent in the derived type definition. For instance:
4629 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
4630 -- type T1 is new R with null record;
4631 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
4633 -- are changed into:
4635 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
4636 -- _parent : R (D1, D2, D3);
4639 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
4640 -- _parent : T1 (X2, 88, X1);
4643 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4644 -- ORC and ICH fields are:
4646 -- Discrim CD ORC ICH
4647 -- ^^^^^^^ ^^ ^^^ ^^^
4648 -- D1 in R empty itself no
4649 -- D2 in R empty itself no
4650 -- D3 in R empty itself no
4652 -- D1 in T1 D1 in R D1 in R no
4653 -- D2 in T1 D2 in R D2 in R no
4654 -- D3 in T1 D3 in R D3 in R no
4656 -- X1 in T2 D3 in T1 D3 in R no
4657 -- X2 in T2 D1 in T1 D1 in R no
4659 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
4661 -- Regardless of whether we dealing with a tagged or untagged type
4662 -- we will transform all derived type declarations of the form
4664 -- type T is new R (...) [with ...];
4666 -- subtype S is R (...);
4667 -- type T is new S [with ...];
4669 -- type BT is new R [with ...];
4670 -- subtype T is BT (...);
4672 -- That is, the base derived type is constrained only if it has no
4673 -- discriminants. The reason for doing this is that GNAT's semantic model
4674 -- assumes that a base type with discriminants is unconstrained.
4676 -- Note that, strictly speaking, the above transformation is not always
4677 -- correct. Consider for instance the following excerpt from ACVC b34011a:
4679 -- procedure B34011A is
4680 -- type REC (D : integer := 0) is record
4685 -- type T6 is new Rec;
4686 -- function F return T6;
4691 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4694 -- The definition of Q6.U is illegal. However transforming Q6.U into
4696 -- type BaseU is new T6;
4697 -- subtype U is BaseU (Q6.F.I)
4699 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4700 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4701 -- the transformation described above.
4703 -- There is another instance where the above transformation is incorrect.
4707 -- type Base (D : Integer) is tagged null record;
4708 -- procedure P (X : Base);
4710 -- type Der is new Base (2) with null record;
4711 -- procedure P (X : Der);
4714 -- Then the above transformation turns this into
4716 -- type Der_Base is new Base with null record;
4717 -- -- procedure P (X : Base) is implicitly inherited here
4718 -- -- as procedure P (X : Der_Base).
4720 -- subtype Der is Der_Base (2);
4721 -- procedure P (X : Der);
4722 -- -- The overriding of P (X : Der_Base) is illegal since we
4723 -- -- have a parameter conformance problem.
4725 -- To get around this problem, after having semantically processed Der_Base
4726 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4727 -- Discriminant_Constraint from Der so that when parameter conformance is
4728 -- checked when P is overridden, no semantic errors are flagged.
4730 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
4732 -- Regardless of whether we are dealing with a tagged or untagged type
4733 -- we will transform all derived type declarations of the form
4735 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4736 -- type T is new R [with ...];
4738 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4740 -- The reason for such transformation is that it allows us to implement a
4741 -- very clean form of component inheritance as explained below.
4743 -- Note that this transformation is not achieved by direct tree rewriting
4744 -- and manipulation, but rather by redoing the semantic actions that the
4745 -- above transformation will entail. This is done directly in routine
4746 -- Inherit_Components.
4748 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
4750 -- In both tagged and untagged derived types, regular non discriminant
4751 -- components are inherited in the derived type from the parent type. In
4752 -- the absence of discriminants component, inheritance is straightforward
4753 -- as components can simply be copied from the parent.
4755 -- If the parent has discriminants, inheriting components constrained with
4756 -- these discriminants requires caution. Consider the following example:
4758 -- type R (D1, D2 : Positive) is [tagged] record
4759 -- S : String (D1 .. D2);
4762 -- type T1 is new R [with null record];
4763 -- type T2 (X : positive) is new R (1, X) [with null record];
4765 -- As explained in 6. above, T1 is rewritten as
4766 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4767 -- which makes the treatment for T1 and T2 identical.
4769 -- What we want when inheriting S, is that references to D1 and D2 in R are
4770 -- replaced with references to their correct constraints, ie D1 and D2 in
4771 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4772 -- with either discriminant references in the derived type or expressions.
4773 -- This replacement is achieved as follows: before inheriting R's
4774 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4775 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4776 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4777 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4778 -- by String (1 .. X).
4780 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
4782 -- We explain here the rules governing private type extensions relevant to
4783 -- type derivation. These rules are explained on the following example:
4785 -- type D [(...)] is new A [(...)] with private; <-- partial view
4786 -- type D [(...)] is new P [(...)] with null record; <-- full view
4788 -- Type A is called the ancestor subtype of the private extension.
4789 -- Type P is the parent type of the full view of the private extension. It
4790 -- must be A or a type derived from A.
4792 -- The rules concerning the discriminants of private type extensions are
4795 -- o If a private extension inherits known discriminants from the ancestor
4796 -- subtype, then the full view shall also inherit its discriminants from
4797 -- the ancestor subtype and the parent subtype of the full view shall be
4798 -- constrained if and only if the ancestor subtype is constrained.
4800 -- o If a partial view has unknown discriminants, then the full view may
4801 -- define a definite or an indefinite subtype, with or without
4804 -- o If a partial view has neither known nor unknown discriminants, then
4805 -- the full view shall define a definite subtype.
4807 -- o If the ancestor subtype of a private extension has constrained
4808 -- discriminants, then the parent subtype of the full view shall impose a
4809 -- statically matching constraint on those discriminants.
4811 -- This means that only the following forms of private extensions are
4814 -- type D is new A with private; <-- partial view
4815 -- type D is new P with null record; <-- full view
4817 -- If A has no discriminants than P has no discriminants, otherwise P must
4818 -- inherit A's discriminants.
4820 -- type D is new A (...) with private; <-- partial view
4821 -- type D is new P (:::) with null record; <-- full view
4823 -- P must inherit A's discriminants and (...) and (:::) must statically
4826 -- subtype A is R (...);
4827 -- type D is new A with private; <-- partial view
4828 -- type D is new P with null record; <-- full view
4830 -- P must have inherited R's discriminants and must be derived from A or
4831 -- any of its subtypes.
4833 -- type D (..) is new A with private; <-- partial view
4834 -- type D (..) is new P [(:::)] with null record; <-- full view
4836 -- No specific constraints on P's discriminants or constraint (:::).
4837 -- Note that A can be unconstrained, but the parent subtype P must either
4838 -- be constrained or (:::) must be present.
4840 -- type D (..) is new A [(...)] with private; <-- partial view
4841 -- type D (..) is new P [(:::)] with null record; <-- full view
4843 -- P's constraints on A's discriminants must statically match those
4844 -- imposed by (...).
4846 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
4848 -- The full view of a private extension is handled exactly as described
4849 -- above. The model chose for the private view of a private extension is
4850 -- the same for what concerns discriminants (ie they receive the same
4851 -- treatment as in the tagged case). However, the private view of the
4852 -- private extension always inherits the components of the parent base,
4853 -- without replacing any discriminant reference. Strictly speaking this is
4854 -- incorrect. However, Gigi never uses this view to generate code so this
4855 -- is a purely semantic issue. In theory, a set of transformations similar
4856 -- to those given in 5. and 6. above could be applied to private views of
4857 -- private extensions to have the same model of component inheritance as
4858 -- for non private extensions. However, this is not done because it would
4859 -- further complicate private type processing. Semantically speaking, this
4860 -- leaves us in an uncomfortable situation. As an example consider:
4863 -- type R (D : integer) is tagged record
4864 -- S : String (1 .. D);
4866 -- procedure P (X : R);
4867 -- type T is new R (1) with private;
4869 -- type T is new R (1) with null record;
4872 -- This is transformed into:
4875 -- type R (D : integer) is tagged record
4876 -- S : String (1 .. D);
4878 -- procedure P (X : R);
4879 -- type T is new R (1) with private;
4881 -- type BaseT is new R with null record;
4882 -- subtype T is BaseT (1);
4885 -- (strictly speaking the above is incorrect Ada)
4887 -- From the semantic standpoint the private view of private extension T
4888 -- should be flagged as constrained since one can clearly have
4892 -- in a unit withing Pack. However, when deriving subprograms for the
4893 -- private view of private extension T, T must be seen as unconstrained
4894 -- since T has discriminants (this is a constraint of the current
4895 -- subprogram derivation model). Thus, when processing the private view of
4896 -- a private extension such as T, we first mark T as unconstrained, we
4897 -- process it, we perform program derivation and just before returning from
4898 -- Build_Derived_Record_Type we mark T as constrained.
4900 -- ??? Are there are other uncomfortable cases that we will have to
4903 -- 10. RECORD_TYPE_WITH_PRIVATE complications
4905 -- Types that are derived from a visible record type and have a private
4906 -- extension present other peculiarities. They behave mostly like private
4907 -- types, but if they have primitive operations defined, these will not
4908 -- have the proper signatures for further inheritance, because other
4909 -- primitive operations will use the implicit base that we define for
4910 -- private derivations below. This affect subprogram inheritance (see
4911 -- Derive_Subprograms for details). We also derive the implicit base from
4912 -- the base type of the full view, so that the implicit base is a record
4913 -- type and not another private type, This avoids infinite loops.
4915 procedure Build_Derived_Record_Type
4917 Parent_Type : Entity_Id;
4918 Derived_Type : Entity_Id;
4919 Derive_Subps : Boolean := True)
4921 Loc : constant Source_Ptr := Sloc (N);
4922 Parent_Base : Entity_Id;
4925 Discrim : Entity_Id;
4926 Last_Discrim : Entity_Id;
4929 Discs : Elist_Id := New_Elmt_List;
4930 -- An empty Discs list means that there were no constraints in the
4931 -- subtype indication or that there was an error processing it.
4933 Assoc_List : Elist_Id;
4934 New_Discrs : Elist_Id;
4935 New_Base : Entity_Id;
4937 New_Indic : Node_Id;
4939 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4940 Discriminant_Specs : constant Boolean :=
4941 Present (Discriminant_Specifications (N));
4942 Private_Extension : constant Boolean :=
4943 (Nkind (N) = N_Private_Extension_Declaration);
4945 Constraint_Present : Boolean;
4946 Inherit_Discrims : Boolean := False;
4948 Save_Etype : Entity_Id;
4949 Save_Discr_Constr : Elist_Id;
4950 Save_Next_Entity : Entity_Id;
4953 if Ekind (Parent_Type) = E_Record_Type_With_Private
4954 and then Present (Full_View (Parent_Type))
4955 and then Has_Discriminants (Parent_Type)
4957 Parent_Base := Base_Type (Full_View (Parent_Type));
4959 Parent_Base := Base_Type (Parent_Type);
4962 -- Before we start the previously documented transformations, here is
4963 -- a little fix for size and alignment of tagged types. Normally when
4964 -- we derive type D from type P, we copy the size and alignment of P
4965 -- as the default for D, and in the absence of explicit representation
4966 -- clauses for D, the size and alignment are indeed the same as the
4969 -- But this is wrong for tagged types, since fields may be added,
4970 -- and the default size may need to be larger, and the default
4971 -- alignment may need to be larger.
4973 -- We therefore reset the size and alignment fields in the tagged
4974 -- case. Note that the size and alignment will in any case be at
4975 -- least as large as the parent type (since the derived type has
4976 -- a copy of the parent type in the _parent field)
4979 Init_Size_Align (Derived_Type);
4982 -- STEP 0a: figure out what kind of derived type declaration we have
4984 if Private_Extension then
4986 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4989 Type_Def := Type_Definition (N);
4991 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4992 -- Parent_Base can be a private type or private extension. However,
4993 -- for tagged types with an extension the newly added fields are
4994 -- visible and hence the Derived_Type is always an E_Record_Type.
4995 -- (except that the parent may have its own private fields).
4996 -- For untagged types we preserve the Ekind of the Parent_Base.
4998 if Present (Record_Extension_Part (Type_Def)) then
4999 Set_Ekind (Derived_Type, E_Record_Type);
5001 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5005 -- Indic can either be an N_Identifier if the subtype indication
5006 -- contains no constraint or an N_Subtype_Indication if the subtype
5007 -- indication has a constraint.
5009 Indic := Subtype_Indication (Type_Def);
5010 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
5012 -- Check that the type has visible discriminants. The type may be
5013 -- a private type with unknown discriminants whose full view has
5014 -- discriminants which are invisible.
5016 if Constraint_Present then
5017 if not Has_Discriminants (Parent_Base)
5019 (Has_Unknown_Discriminants (Parent_Base)
5020 and then Is_Private_Type (Parent_Base))
5023 ("invalid constraint: type has no discriminant",
5024 Constraint (Indic));
5026 Constraint_Present := False;
5027 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
5029 elsif Is_Constrained (Parent_Type) then
5031 ("invalid constraint: parent type is already constrained",
5032 Constraint (Indic));
5034 Constraint_Present := False;
5035 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
5039 -- STEP 0b: If needed, apply transformation given in point 5. above
5041 if not Private_Extension
5042 and then Has_Discriminants (Parent_Type)
5043 and then not Discriminant_Specs
5044 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
5046 -- First, we must analyze the constraint (see comment in point 5.)
5048 if Constraint_Present then
5049 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
5051 if Has_Discriminants (Derived_Type)
5052 and then Has_Private_Declaration (Derived_Type)
5053 and then Present (Discriminant_Constraint (Derived_Type))
5055 -- Verify that constraints of the full view conform to those
5056 -- given in partial view.
5062 C1 := First_Elmt (New_Discrs);
5063 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
5065 while Present (C1) and then Present (C2) loop
5067 Fully_Conformant_Expressions (Node (C1), Node (C2))
5070 "constraint not conformant to previous declaration",
5080 -- Insert and analyze the declaration for the unconstrained base type
5082 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
5085 Make_Full_Type_Declaration (Loc,
5086 Defining_Identifier => New_Base,
5088 Make_Derived_Type_Definition (Loc,
5089 Abstract_Present => Abstract_Present (Type_Def),
5090 Subtype_Indication =>
5091 New_Occurrence_Of (Parent_Base, Loc),
5092 Record_Extension_Part =>
5093 Relocate_Node (Record_Extension_Part (Type_Def))));
5095 Set_Parent (New_Decl, Parent (N));
5096 Mark_Rewrite_Insertion (New_Decl);
5097 Insert_Before (N, New_Decl);
5099 -- Note that this call passes False for the Derive_Subps parameter
5100 -- because subprogram derivation is deferred until after creating
5101 -- the subtype (see below).
5104 (New_Decl, Parent_Base, New_Base,
5105 Is_Completion => True, Derive_Subps => False);
5107 -- ??? This needs re-examination to determine whether the
5108 -- above call can simply be replaced by a call to Analyze.
5110 Set_Analyzed (New_Decl);
5112 -- Insert and analyze the declaration for the constrained subtype
5114 if Constraint_Present then
5116 Make_Subtype_Indication (Loc,
5117 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
5118 Constraint => Relocate_Node (Constraint (Indic)));
5122 Constr_List : constant List_Id := New_List;
5127 C := First_Elmt (Discriminant_Constraint (Parent_Type));
5128 while Present (C) loop
5131 -- It is safe here to call New_Copy_Tree since
5132 -- Force_Evaluation was called on each constraint in
5133 -- Build_Discriminant_Constraints.
5135 Append (New_Copy_Tree (Expr), To => Constr_List);
5141 Make_Subtype_Indication (Loc,
5142 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
5144 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
5149 Make_Subtype_Declaration (Loc,
5150 Defining_Identifier => Derived_Type,
5151 Subtype_Indication => New_Indic));
5155 -- Derivation of subprograms must be delayed until the full subtype
5156 -- has been established to ensure proper overriding of subprograms
5157 -- inherited by full types. If the derivations occurred as part of
5158 -- the call to Build_Derived_Type above, then the check for type
5159 -- conformance would fail because earlier primitive subprograms
5160 -- could still refer to the full type prior the change to the new
5161 -- subtype and hence would not match the new base type created here.
5163 Derive_Subprograms (Parent_Type, Derived_Type);
5165 -- For tagged types the Discriminant_Constraint of the new base itype
5166 -- is inherited from the first subtype so that no subtype conformance
5167 -- problem arise when the first subtype overrides primitive
5168 -- operations inherited by the implicit base type.
5171 Set_Discriminant_Constraint
5172 (New_Base, Discriminant_Constraint (Derived_Type));
5178 -- If we get here Derived_Type will have no discriminants or it will be
5179 -- a discriminated unconstrained base type.
5181 -- STEP 1a: perform preliminary actions/checks for derived tagged types
5185 -- The parent type is frozen for non-private extensions (RM 13.14(7))
5187 if not Private_Extension then
5188 Freeze_Before (N, Parent_Type);
5191 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
5192 and then not Is_Generic_Type (Derived_Type)
5194 if Is_Controlled (Parent_Type) then
5196 ("controlled type must be declared at the library level",
5200 ("type extension at deeper accessibility level than parent",
5206 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
5210 and then GB /= Enclosing_Generic_Body (Parent_Base)
5213 ("parent type of& must not be outside generic body"
5214 & " ('R'M 3.9.1(4))",
5215 Indic, Derived_Type);
5221 -- STEP 1b : preliminary cleanup of the full view of private types
5223 -- If the type is already marked as having discriminants, then it's the
5224 -- completion of a private type or private extension and we need to
5225 -- retain the discriminants from the partial view if the current
5226 -- declaration has Discriminant_Specifications so that we can verify
5227 -- conformance. However, we must remove any existing components that
5228 -- were inherited from the parent (and attached in Copy_And_Swap)
5229 -- because the full type inherits all appropriate components anyway, and
5230 -- we do not want the partial view's components interfering.
5232 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
5233 Discrim := First_Discriminant (Derived_Type);
5235 Last_Discrim := Discrim;
5236 Next_Discriminant (Discrim);
5237 exit when No (Discrim);
5240 Set_Last_Entity (Derived_Type, Last_Discrim);
5242 -- In all other cases wipe out the list of inherited components (even
5243 -- inherited discriminants), it will be properly rebuilt here.
5246 Set_First_Entity (Derived_Type, Empty);
5247 Set_Last_Entity (Derived_Type, Empty);
5250 -- STEP 1c: Initialize some flags for the Derived_Type
5252 -- The following flags must be initialized here so that
5253 -- Process_Discriminants can check that discriminants of tagged types
5254 -- do not have a default initial value and that access discriminants
5255 -- are only specified for limited records. For completeness, these
5256 -- flags are also initialized along with all the other flags below.
5258 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
5259 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
5261 -- STEP 2a: process discriminants of derived type if any
5263 New_Scope (Derived_Type);
5265 if Discriminant_Specs then
5266 Set_Has_Unknown_Discriminants (Derived_Type, False);
5268 -- The following call initializes fields Has_Discriminants and
5269 -- Discriminant_Constraint, unless we are processing the completion
5270 -- of a private type declaration.
5272 Check_Or_Process_Discriminants (N, Derived_Type);
5274 -- For non-tagged types the constraint on the Parent_Type must be
5275 -- present and is used to rename the discriminants.
5277 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
5278 Error_Msg_N ("untagged parent must have discriminants", Indic);
5280 elsif not Is_Tagged and then not Constraint_Present then
5282 ("discriminant constraint needed for derived untagged records",
5285 -- Otherwise the parent subtype must be constrained unless we have a
5286 -- private extension.
5288 elsif not Constraint_Present
5289 and then not Private_Extension
5290 and then not Is_Constrained (Parent_Type)
5293 ("unconstrained type not allowed in this context", Indic);
5295 elsif Constraint_Present then
5296 -- The following call sets the field Corresponding_Discriminant
5297 -- for the discriminants in the Derived_Type.
5299 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
5301 -- For untagged types all new discriminants must rename
5302 -- discriminants in the parent. For private extensions new
5303 -- discriminants cannot rename old ones (implied by [7.3(13)]).
5305 Discrim := First_Discriminant (Derived_Type);
5306 while Present (Discrim) loop
5308 and then not Present (Corresponding_Discriminant (Discrim))
5311 ("new discriminants must constrain old ones", Discrim);
5313 elsif Private_Extension
5314 and then Present (Corresponding_Discriminant (Discrim))
5317 ("only static constraints allowed for parent"
5318 & " discriminants in the partial view", Indic);
5322 -- If a new discriminant is used in the constraint, then its
5323 -- subtype must be statically compatible with the parent
5324 -- discriminant's subtype (3.7(15)).
5326 if Present (Corresponding_Discriminant (Discrim))
5328 not Subtypes_Statically_Compatible
5330 Etype (Corresponding_Discriminant (Discrim)))
5333 ("subtype must be compatible with parent discriminant",
5337 Next_Discriminant (Discrim);
5340 -- Check whether the constraints of the full view statically
5341 -- match those imposed by the parent subtype [7.3(13)].
5343 if Present (Stored_Constraint (Derived_Type)) then
5348 C1 := First_Elmt (Discs);
5349 C2 := First_Elmt (Stored_Constraint (Derived_Type));
5350 while Present (C1) and then Present (C2) loop
5352 Fully_Conformant_Expressions (Node (C1), Node (C2))
5355 "not conformant with previous declaration",
5366 -- STEP 2b: No new discriminants, inherit discriminants if any
5369 if Private_Extension then
5370 Set_Has_Unknown_Discriminants
5372 Has_Unknown_Discriminants (Parent_Type)
5373 or else Unknown_Discriminants_Present (N));
5375 -- The partial view of the parent may have unknown discriminants,
5376 -- but if the full view has discriminants and the parent type is
5377 -- in scope they must be inherited.
5379 elsif Has_Unknown_Discriminants (Parent_Type)
5381 (not Has_Discriminants (Parent_Type)
5382 or else not In_Open_Scopes (Scope (Parent_Type)))
5384 Set_Has_Unknown_Discriminants (Derived_Type);
5387 if not Has_Unknown_Discriminants (Derived_Type)
5388 and then not Has_Unknown_Discriminants (Parent_Base)
5389 and then Has_Discriminants (Parent_Type)
5391 Inherit_Discrims := True;
5392 Set_Has_Discriminants
5393 (Derived_Type, True);
5394 Set_Discriminant_Constraint
5395 (Derived_Type, Discriminant_Constraint (Parent_Base));
5398 -- The following test is true for private types (remember
5399 -- transformation 5. is not applied to those) and in an error
5402 if Constraint_Present then
5403 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
5406 -- For now mark a new derived type as constrained only if it has no
5407 -- discriminants. At the end of Build_Derived_Record_Type we properly
5408 -- set this flag in the case of private extensions. See comments in
5409 -- point 9. just before body of Build_Derived_Record_Type.
5413 not (Inherit_Discrims
5414 or else Has_Unknown_Discriminants (Derived_Type)));
5417 -- STEP 3: initialize fields of derived type
5419 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
5420 Set_Stored_Constraint (Derived_Type, No_Elist);
5422 -- Fields inherited from the Parent_Type
5425 (Derived_Type, Einfo.Discard_Names (Parent_Type));
5426 Set_Has_Specified_Layout
5427 (Derived_Type, Has_Specified_Layout (Parent_Type));
5428 Set_Is_Limited_Composite
5429 (Derived_Type, Is_Limited_Composite (Parent_Type));
5430 Set_Is_Limited_Record
5431 (Derived_Type, Is_Limited_Record (Parent_Type));
5432 Set_Is_Private_Composite
5433 (Derived_Type, Is_Private_Composite (Parent_Type));
5435 -- Fields inherited from the Parent_Base
5437 Set_Has_Controlled_Component
5438 (Derived_Type, Has_Controlled_Component (Parent_Base));
5439 Set_Has_Non_Standard_Rep
5440 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
5441 Set_Has_Primitive_Operations
5442 (Derived_Type, Has_Primitive_Operations (Parent_Base));
5444 -- Direct controlled types do not inherit Finalize_Storage_Only flag
5446 if not Is_Controlled (Parent_Type) then
5447 Set_Finalize_Storage_Only
5448 (Derived_Type, Finalize_Storage_Only (Parent_Type));
5451 -- Set fields for private derived types
5453 if Is_Private_Type (Derived_Type) then
5454 Set_Depends_On_Private (Derived_Type, True);
5455 Set_Private_Dependents (Derived_Type, New_Elmt_List);
5457 -- Inherit fields from non private record types. If this is the
5458 -- completion of a derivation from a private type, the parent itself
5459 -- is private, and the attributes come from its full view, which must
5463 if Is_Private_Type (Parent_Base)
5464 and then not Is_Record_Type (Parent_Base)
5466 Set_Component_Alignment
5467 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
5469 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
5471 Set_Component_Alignment
5472 (Derived_Type, Component_Alignment (Parent_Base));
5475 (Derived_Type, C_Pass_By_Copy (Parent_Base));
5479 -- Set fields for tagged types
5482 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
5484 -- All tagged types defined in Ada.Finalization are controlled
5486 if Chars (Scope (Derived_Type)) = Name_Finalization
5487 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
5488 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
5490 Set_Is_Controlled (Derived_Type);
5492 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
5495 Make_Class_Wide_Type (Derived_Type);
5496 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
5498 if Has_Discriminants (Derived_Type)
5499 and then Constraint_Present
5501 Set_Stored_Constraint
5502 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
5506 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
5507 Set_Has_Non_Standard_Rep
5508 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
5511 -- STEP 4: Inherit components from the parent base and constrain them.
5512 -- Apply the second transformation described in point 6. above.
5514 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
5515 or else not Has_Discriminants (Parent_Type)
5516 or else not Is_Constrained (Parent_Type)
5520 Constrs := Discriminant_Constraint (Parent_Type);
5523 Assoc_List := Inherit_Components (N,
5524 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
5526 -- STEP 5a: Copy the parent record declaration for untagged types
5528 if not Is_Tagged then
5530 -- Discriminant_Constraint (Derived_Type) has been properly
5531 -- constructed. Save it and temporarily set it to Empty because we
5532 -- do not want the call to New_Copy_Tree below to mess this list.
5534 if Has_Discriminants (Derived_Type) then
5535 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
5536 Set_Discriminant_Constraint (Derived_Type, No_Elist);
5538 Save_Discr_Constr := No_Elist;
5541 -- Save the Etype field of Derived_Type. It is correctly set now,
5542 -- but the call to New_Copy tree may remap it to point to itself,
5543 -- which is not what we want. Ditto for the Next_Entity field.
5545 Save_Etype := Etype (Derived_Type);
5546 Save_Next_Entity := Next_Entity (Derived_Type);
5548 -- Assoc_List maps all stored discriminants in the Parent_Base to
5549 -- stored discriminants in the Derived_Type. It is fundamental that
5550 -- no types or itypes with discriminants other than the stored
5551 -- discriminants appear in the entities declared inside
5552 -- Derived_Type, since the back end cannot deal with it.
5556 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
5558 -- Restore the fields saved prior to the New_Copy_Tree call
5559 -- and compute the stored constraint.
5561 Set_Etype (Derived_Type, Save_Etype);
5562 Set_Next_Entity (Derived_Type, Save_Next_Entity);
5564 if Has_Discriminants (Derived_Type) then
5565 Set_Discriminant_Constraint
5566 (Derived_Type, Save_Discr_Constr);
5567 Set_Stored_Constraint
5568 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
5569 Replace_Components (Derived_Type, New_Decl);
5572 -- Insert the new derived type declaration
5574 Rewrite (N, New_Decl);
5576 -- STEP 5b: Complete the processing for record extensions in generics
5578 -- There is no completion for record extensions declared in the
5579 -- parameter part of a generic, so we need to complete processing for
5580 -- these generic record extensions here. The Record_Type_Definition call
5581 -- will change the Ekind of the components from E_Void to E_Component.
5583 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
5584 Record_Type_Definition (Empty, Derived_Type);
5586 -- STEP 5c: Process the record extension for non private tagged types
5588 elsif not Private_Extension then
5590 -- Add the _parent field in the derived type
5592 Expand_Record_Extension (Derived_Type, Type_Def);
5594 -- Analyze the record extension
5596 Record_Type_Definition
5597 (Record_Extension_Part (Type_Def), Derived_Type);
5602 if Etype (Derived_Type) = Any_Type then
5606 -- Set delayed freeze and then derive subprograms, we need to do
5607 -- this in this order so that derived subprograms inherit the
5608 -- derived freeze if necessary.
5610 Set_Has_Delayed_Freeze (Derived_Type);
5611 if Derive_Subps then
5612 Derive_Subprograms (Parent_Type, Derived_Type);
5615 -- If we have a private extension which defines a constrained derived
5616 -- type mark as constrained here after we have derived subprograms. See
5617 -- comment on point 9. just above the body of Build_Derived_Record_Type.
5619 if Private_Extension and then Inherit_Discrims then
5620 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
5621 Set_Is_Constrained (Derived_Type, True);
5622 Set_Discriminant_Constraint (Derived_Type, Discs);
5624 elsif Is_Constrained (Parent_Type) then
5626 (Derived_Type, True);
5627 Set_Discriminant_Constraint
5628 (Derived_Type, Discriminant_Constraint (Parent_Type));
5632 -- Update the class_wide type, which shares the now-completed
5633 -- entity list with its specific type.
5637 (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
5639 (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
5642 end Build_Derived_Record_Type;
5644 ------------------------
5645 -- Build_Derived_Type --
5646 ------------------------
5648 procedure Build_Derived_Type
5650 Parent_Type : Entity_Id;
5651 Derived_Type : Entity_Id;
5652 Is_Completion : Boolean;
5653 Derive_Subps : Boolean := True)
5655 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5658 -- Set common attributes
5660 Set_Scope (Derived_Type, Current_Scope);
5662 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5663 Set_Etype (Derived_Type, Parent_Base);
5664 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
5666 Set_Size_Info (Derived_Type, Parent_Type);
5667 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5668 Set_Convention (Derived_Type, Convention (Parent_Type));
5669 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
5671 -- The derived type inherits the representation clauses of the parent.
5672 -- However, for a private type that is completed by a derivation, there
5673 -- may be operation attributes that have been specified already (stream
5674 -- attributes and External_Tag) and those must be provided. Finally,
5675 -- if the partial view is a private extension, the representation items
5676 -- of the parent have been inherited already, and should not be chained
5677 -- twice to the derived type.
5679 if Is_Tagged_Type (Parent_Type)
5680 and then Present (First_Rep_Item (Derived_Type))
5682 -- The existing items are either operational items or items inherited
5683 -- from a private extension declaration.
5686 Rep : Node_Id := First_Rep_Item (Derived_Type);
5687 Found : Boolean := False;
5690 while Present (Rep) loop
5691 if Rep = First_Rep_Item (Parent_Type) then
5695 Rep := Next_Rep_Item (Rep);
5701 (First_Rep_Item (Derived_Type), First_Rep_Item (Parent_Type));
5706 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
5709 case Ekind (Parent_Type) is
5710 when Numeric_Kind =>
5711 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
5714 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
5718 | Class_Wide_Kind =>
5719 Build_Derived_Record_Type
5720 (N, Parent_Type, Derived_Type, Derive_Subps);
5723 when Enumeration_Kind =>
5724 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5727 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5729 when Incomplete_Or_Private_Kind =>
5730 Build_Derived_Private_Type
5731 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5733 -- For discriminated types, the derivation includes deriving
5734 -- primitive operations. For others it is done below.
5736 if Is_Tagged_Type (Parent_Type)
5737 or else Has_Discriminants (Parent_Type)
5738 or else (Present (Full_View (Parent_Type))
5739 and then Has_Discriminants (Full_View (Parent_Type)))
5744 when Concurrent_Kind =>
5745 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5748 raise Program_Error;
5751 if Etype (Derived_Type) = Any_Type then
5755 -- Set delayed freeze and then derive subprograms, we need to do this
5756 -- in this order so that derived subprograms inherit the derived freeze
5759 Set_Has_Delayed_Freeze (Derived_Type);
5760 if Derive_Subps then
5761 Derive_Subprograms (Parent_Type, Derived_Type);
5764 Set_Has_Primitive_Operations
5765 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5766 end Build_Derived_Type;
5768 -----------------------
5769 -- Build_Discriminal --
5770 -----------------------
5772 procedure Build_Discriminal (Discrim : Entity_Id) is
5773 D_Minal : Entity_Id;
5774 CR_Disc : Entity_Id;
5777 -- A discriminal has the same name as the discriminant
5780 Make_Defining_Identifier (Sloc (Discrim),
5781 Chars => Chars (Discrim));
5783 Set_Ekind (D_Minal, E_In_Parameter);
5784 Set_Mechanism (D_Minal, Default_Mechanism);
5785 Set_Etype (D_Minal, Etype (Discrim));
5787 Set_Discriminal (Discrim, D_Minal);
5788 Set_Discriminal_Link (D_Minal, Discrim);
5790 -- For task types, build at once the discriminants of the corresponding
5791 -- record, which are needed if discriminants are used in entry defaults
5792 -- and in family bounds.
5794 if Is_Concurrent_Type (Current_Scope)
5795 or else Is_Limited_Type (Current_Scope)
5797 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5799 Set_Ekind (CR_Disc, E_In_Parameter);
5800 Set_Mechanism (CR_Disc, Default_Mechanism);
5801 Set_Etype (CR_Disc, Etype (Discrim));
5802 Set_CR_Discriminant (Discrim, CR_Disc);
5804 end Build_Discriminal;
5806 ------------------------------------
5807 -- Build_Discriminant_Constraints --
5808 ------------------------------------
5810 function Build_Discriminant_Constraints
5813 Derived_Def : Boolean := False) return Elist_Id
5815 C : constant Node_Id := Constraint (Def);
5816 Nb_Discr : constant Nat := Number_Discriminants (T);
5818 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5819 -- Saves the expression corresponding to a given discriminant in T
5821 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5822 -- Return the Position number within array Discr_Expr of a discriminant
5823 -- D within the discriminant list of the discriminated type T.
5829 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5833 Disc := First_Discriminant (T);
5834 for J in Discr_Expr'Range loop
5839 Next_Discriminant (Disc);
5842 -- Note: Since this function is called on discriminants that are
5843 -- known to belong to the discriminated type, falling through the
5844 -- loop with no match signals an internal compiler error.
5846 raise Program_Error;
5849 -- Declarations local to Build_Discriminant_Constraints
5853 Elist : constant Elist_Id := New_Elmt_List;
5861 Discrim_Present : Boolean := False;
5863 -- Start of processing for Build_Discriminant_Constraints
5866 -- The following loop will process positional associations only.
5867 -- For a positional association, the (single) discriminant is
5868 -- implicitly specified by position, in textual order (RM 3.7.2).
5870 Discr := First_Discriminant (T);
5871 Constr := First (Constraints (C));
5873 for D in Discr_Expr'Range loop
5874 exit when Nkind (Constr) = N_Discriminant_Association;
5877 Error_Msg_N ("too few discriminants given in constraint", C);
5878 return New_Elmt_List;
5880 elsif Nkind (Constr) = N_Range
5881 or else (Nkind (Constr) = N_Attribute_Reference
5883 Attribute_Name (Constr) = Name_Range)
5886 ("a range is not a valid discriminant constraint", Constr);
5887 Discr_Expr (D) := Error;
5890 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5891 Discr_Expr (D) := Constr;
5894 Next_Discriminant (Discr);
5898 if No (Discr) and then Present (Constr) then
5899 Error_Msg_N ("too many discriminants given in constraint", Constr);
5900 return New_Elmt_List;
5903 -- Named associations can be given in any order, but if both positional
5904 -- and named associations are used in the same discriminant constraint,
5905 -- then positional associations must occur first, at their normal
5906 -- position. Hence once a named association is used, the rest of the
5907 -- discriminant constraint must use only named associations.
5909 while Present (Constr) loop
5911 -- Positional association forbidden after a named association
5913 if Nkind (Constr) /= N_Discriminant_Association then
5914 Error_Msg_N ("positional association follows named one", Constr);
5915 return New_Elmt_List;
5917 -- Otherwise it is a named association
5920 -- E records the type of the discriminants in the named
5921 -- association. All the discriminants specified in the same name
5922 -- association must have the same type.
5926 -- Search the list of discriminants in T to see if the simple name
5927 -- given in the constraint matches any of them.
5929 Id := First (Selector_Names (Constr));
5930 while Present (Id) loop
5933 -- If Original_Discriminant is present, we are processing a
5934 -- generic instantiation and this is an instance node. We need
5935 -- to find the name of the corresponding discriminant in the
5936 -- actual record type T and not the name of the discriminant in
5937 -- the generic formal. Example:
5940 -- type G (D : int) is private;
5942 -- subtype W is G (D => 1);
5944 -- type Rec (X : int) is record ... end record;
5945 -- package Q is new P (G => Rec);
5947 -- At the point of the instantiation, formal type G is Rec
5948 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5949 -- which really looks like "subtype W is Rec (D => 1);" at
5950 -- the point of instantiation, we want to find the discriminant
5951 -- that corresponds to D in Rec, ie X.
5953 if Present (Original_Discriminant (Id)) then
5954 Discr := Find_Corresponding_Discriminant (Id, T);
5958 Discr := First_Discriminant (T);
5959 while Present (Discr) loop
5960 if Chars (Discr) = Chars (Id) then
5965 Next_Discriminant (Discr);
5969 Error_Msg_N ("& does not match any discriminant", Id);
5970 return New_Elmt_List;
5972 -- The following is only useful for the benefit of generic
5973 -- instances but it does not interfere with other
5974 -- processing for the non-generic case so we do it in all
5975 -- cases (for generics this statement is executed when
5976 -- processing the generic definition, see comment at the
5977 -- beginning of this if statement).
5980 Set_Original_Discriminant (Id, Discr);
5984 Position := Pos_Of_Discr (T, Discr);
5986 if Present (Discr_Expr (Position)) then
5987 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5990 -- Each discriminant specified in the same named association
5991 -- must be associated with a separate copy of the
5992 -- corresponding expression.
5994 if Present (Next (Id)) then
5995 Expr := New_Copy_Tree (Expression (Constr));
5996 Set_Parent (Expr, Parent (Expression (Constr)));
5998 Expr := Expression (Constr);
6001 Discr_Expr (Position) := Expr;
6002 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
6005 -- A discriminant association with more than one discriminant
6006 -- name is only allowed if the named discriminants are all of
6007 -- the same type (RM 3.7.1(8)).
6010 E := Base_Type (Etype (Discr));
6012 elsif Base_Type (Etype (Discr)) /= E then
6014 ("all discriminants in an association " &
6015 "must have the same type", Id);
6025 -- A discriminant constraint must provide exactly one value for each
6026 -- discriminant of the type (RM 3.7.1(8)).
6028 for J in Discr_Expr'Range loop
6029 if No (Discr_Expr (J)) then
6030 Error_Msg_N ("too few discriminants given in constraint", C);
6031 return New_Elmt_List;
6035 -- Determine if there are discriminant expressions in the constraint
6037 for J in Discr_Expr'Range loop
6038 if Denotes_Discriminant (Discr_Expr (J), Check_Protected => True) then
6039 Discrim_Present := True;
6043 -- Build an element list consisting of the expressions given in the
6044 -- discriminant constraint and apply the appropriate checks. The list
6045 -- is constructed after resolving any named discriminant associations
6046 -- and therefore the expressions appear in the textual order of the
6049 Discr := First_Discriminant (T);
6050 for J in Discr_Expr'Range loop
6051 if Discr_Expr (J) /= Error then
6053 Append_Elmt (Discr_Expr (J), Elist);
6055 -- If any of the discriminant constraints is given by a
6056 -- discriminant and we are in a derived type declaration we
6057 -- have a discriminant renaming. Establish link between new
6058 -- and old discriminant.
6060 if Denotes_Discriminant (Discr_Expr (J)) then
6062 Set_Corresponding_Discriminant
6063 (Entity (Discr_Expr (J)), Discr);
6066 -- Force the evaluation of non-discriminant expressions.
6067 -- If we have found a discriminant in the constraint 3.4(26)
6068 -- and 3.8(18) demand that no range checks are performed are
6069 -- after evaluation. If the constraint is for a component
6070 -- definition that has a per-object constraint, expressions are
6071 -- evaluated but not checked either. In all other cases perform
6075 if Discrim_Present then
6078 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
6080 Has_Per_Object_Constraint
6081 (Defining_Identifier (Parent (Parent (Def))))
6085 elsif Is_Access_Type (Etype (Discr)) then
6086 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
6089 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
6092 Force_Evaluation (Discr_Expr (J));
6095 -- Check that the designated type of an access discriminant's
6096 -- expression is not a class-wide type unless the discriminant's
6097 -- designated type is also class-wide.
6099 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
6100 and then not Is_Class_Wide_Type
6101 (Designated_Type (Etype (Discr)))
6102 and then Etype (Discr_Expr (J)) /= Any_Type
6103 and then Is_Class_Wide_Type
6104 (Designated_Type (Etype (Discr_Expr (J))))
6106 Wrong_Type (Discr_Expr (J), Etype (Discr));
6110 Next_Discriminant (Discr);
6114 end Build_Discriminant_Constraints;
6116 ---------------------------------
6117 -- Build_Discriminated_Subtype --
6118 ---------------------------------
6120 procedure Build_Discriminated_Subtype
6124 Related_Nod : Node_Id;
6125 For_Access : Boolean := False)
6127 Has_Discrs : constant Boolean := Has_Discriminants (T);
6128 Constrained : constant Boolean
6130 and then not Is_Empty_Elmt_List (Elist)
6131 and then not Is_Class_Wide_Type (T))
6132 or else Is_Constrained (T);
6135 if Ekind (T) = E_Record_Type then
6137 Set_Ekind (Def_Id, E_Private_Subtype);
6138 Set_Is_For_Access_Subtype (Def_Id, True);
6140 Set_Ekind (Def_Id, E_Record_Subtype);
6143 elsif Ekind (T) = E_Task_Type then
6144 Set_Ekind (Def_Id, E_Task_Subtype);
6146 elsif Ekind (T) = E_Protected_Type then
6147 Set_Ekind (Def_Id, E_Protected_Subtype);
6149 elsif Is_Private_Type (T) then
6150 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
6152 elsif Is_Class_Wide_Type (T) then
6153 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
6156 -- Incomplete type. attach subtype to list of dependents, to be
6157 -- completed with full view of parent type, unless is it the
6158 -- designated subtype of a record component within an init_proc.
6159 -- This last case arises for a component of an access type whose
6160 -- designated type is incomplete (e.g. a Taft Amendment type).
6161 -- The designated subtype is within an inner scope, and needs no
6162 -- elaboration, because only the access type is needed in the
6163 -- initialization procedure.
6165 Set_Ekind (Def_Id, Ekind (T));
6167 if For_Access and then Within_Init_Proc then
6170 Append_Elmt (Def_Id, Private_Dependents (T));
6174 Set_Etype (Def_Id, T);
6175 Init_Size_Align (Def_Id);
6176 Set_Has_Discriminants (Def_Id, Has_Discrs);
6177 Set_Is_Constrained (Def_Id, Constrained);
6179 Set_First_Entity (Def_Id, First_Entity (T));
6180 Set_Last_Entity (Def_Id, Last_Entity (T));
6181 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6183 if Is_Tagged_Type (T) then
6184 Set_Is_Tagged_Type (Def_Id);
6185 Make_Class_Wide_Type (Def_Id);
6188 Set_Stored_Constraint (Def_Id, No_Elist);
6191 Set_Discriminant_Constraint (Def_Id, Elist);
6192 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
6195 if Is_Tagged_Type (T) then
6196 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
6197 Set_Is_Abstract (Def_Id, Is_Abstract (T));
6200 -- Subtypes introduced by component declarations do not need to be
6201 -- marked as delayed, and do not get freeze nodes, because the semantics
6202 -- verifies that the parents of the subtypes are frozen before the
6203 -- enclosing record is frozen.
6205 if not Is_Type (Scope (Def_Id)) then
6206 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6208 if Is_Private_Type (T)
6209 and then Present (Full_View (T))
6211 Conditional_Delay (Def_Id, Full_View (T));
6213 Conditional_Delay (Def_Id, T);
6217 if Is_Record_Type (T) then
6218 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
6221 and then not Is_Empty_Elmt_List (Elist)
6222 and then not For_Access
6224 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
6225 elsif not For_Access then
6226 Set_Cloned_Subtype (Def_Id, T);
6230 end Build_Discriminated_Subtype;
6232 ------------------------
6233 -- Build_Scalar_Bound --
6234 ------------------------
6236 function Build_Scalar_Bound
6239 Der_T : Entity_Id) return Node_Id
6241 New_Bound : Entity_Id;
6244 -- Note: not clear why this is needed, how can the original bound
6245 -- be unanalyzed at this point? and if it is, what business do we
6246 -- have messing around with it? and why is the base type of the
6247 -- parent type the right type for the resolution. It probably is
6248 -- not! It is OK for the new bound we are creating, but not for
6249 -- the old one??? Still if it never happens, no problem!
6251 Analyze_And_Resolve (Bound, Base_Type (Par_T));
6253 if Nkind (Bound) = N_Integer_Literal
6254 or else Nkind (Bound) = N_Real_Literal
6256 New_Bound := New_Copy (Bound);
6257 Set_Etype (New_Bound, Der_T);
6258 Set_Analyzed (New_Bound);
6260 elsif Is_Entity_Name (Bound) then
6261 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
6263 -- The following is almost certainly wrong. What business do we have
6264 -- relocating a node (Bound) that is presumably still attached to
6265 -- the tree elsewhere???
6268 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
6271 Set_Etype (New_Bound, Der_T);
6273 end Build_Scalar_Bound;
6275 --------------------------------
6276 -- Build_Underlying_Full_View --
6277 --------------------------------
6279 procedure Build_Underlying_Full_View
6284 Loc : constant Source_Ptr := Sloc (N);
6285 Subt : constant Entity_Id :=
6286 Make_Defining_Identifier
6287 (Loc, New_External_Name (Chars (Typ), 'S'));
6294 procedure Set_Discriminant_Name (Id : Node_Id);
6295 -- If the derived type has discriminants, they may rename discriminants
6296 -- of the parent. When building the full view of the parent, we need to
6297 -- recover the names of the original discriminants if the constraint is
6298 -- given by named associations.
6300 ---------------------------
6301 -- Set_Discriminant_Name --
6302 ---------------------------
6304 procedure Set_Discriminant_Name (Id : Node_Id) is
6308 Set_Original_Discriminant (Id, Empty);
6310 if Has_Discriminants (Typ) then
6311 Disc := First_Discriminant (Typ);
6313 while Present (Disc) loop
6314 if Chars (Disc) = Chars (Id)
6315 and then Present (Corresponding_Discriminant (Disc))
6317 Set_Chars (Id, Chars (Corresponding_Discriminant (Disc)));
6319 Next_Discriminant (Disc);
6322 end Set_Discriminant_Name;
6324 -- Start of processing for Build_Underlying_Full_View
6327 if Nkind (N) = N_Full_Type_Declaration then
6328 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
6330 elsif Nkind (N) = N_Subtype_Declaration then
6331 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
6333 elsif Nkind (N) = N_Component_Declaration then
6336 (Constraint (Subtype_Indication (Component_Definition (N))));
6339 raise Program_Error;
6342 C := First (Constraints (Constr));
6343 while Present (C) loop
6344 if Nkind (C) = N_Discriminant_Association then
6345 Id := First (Selector_Names (C));
6346 while Present (Id) loop
6347 Set_Discriminant_Name (Id);
6356 Make_Subtype_Declaration (Loc,
6357 Defining_Identifier => Subt,
6358 Subtype_Indication =>
6359 Make_Subtype_Indication (Loc,
6360 Subtype_Mark => New_Reference_To (Par, Loc),
6361 Constraint => New_Copy_Tree (Constr)));
6363 -- If this is a component subtype for an outer itype, it is not
6364 -- a list member, so simply set the parent link for analysis: if
6365 -- the enclosing type does not need to be in a declarative list,
6366 -- neither do the components.
6368 if Is_List_Member (N)
6369 and then Nkind (N) /= N_Component_Declaration
6371 Insert_Before (N, Indic);
6373 Set_Parent (Indic, Parent (N));
6377 Set_Underlying_Full_View (Typ, Full_View (Subt));
6378 end Build_Underlying_Full_View;
6380 -------------------------------
6381 -- Check_Abstract_Overriding --
6382 -------------------------------
6384 procedure Check_Abstract_Overriding (T : Entity_Id) is
6391 Op_List := Primitive_Operations (T);
6393 -- Loop to check primitive operations
6395 Elmt := First_Elmt (Op_List);
6396 while Present (Elmt) loop
6397 Subp := Node (Elmt);
6399 -- Special exception, do not complain about failure to override the
6400 -- stream routines _Input and _Output, since we always provide
6401 -- automatic overridings for these subprograms.
6403 if Is_Abstract (Subp)
6404 and then not Is_TSS (Subp, TSS_Stream_Input)
6405 and then not Is_TSS (Subp, TSS_Stream_Output)
6406 and then not Is_Abstract (T)
6408 if Present (Alias (Subp)) then
6409 -- Only perform the check for a derived subprogram when
6410 -- the type has an explicit record extension. This avoids
6411 -- incorrectly flagging abstract subprograms for the case
6412 -- of a type without an extension derived from a formal type
6413 -- with a tagged actual (can occur within a private part).
6415 Type_Def := Type_Definition (Parent (T));
6416 if Nkind (Type_Def) = N_Derived_Type_Definition
6417 and then Present (Record_Extension_Part (Type_Def))
6420 ("type must be declared abstract or & overridden",
6425 ("abstract subprogram not allowed for type&",
6428 ("nonabstract type has abstract subprogram&",
6435 end Check_Abstract_Overriding;
6437 ------------------------------------------------
6438 -- Check_Access_Discriminant_Requires_Limited --
6439 ------------------------------------------------
6441 procedure Check_Access_Discriminant_Requires_Limited
6446 -- A discriminant_specification for an access discriminant
6447 -- shall appear only in the declaration for a task or protected
6448 -- type, or for a type with the reserved word 'limited' in
6449 -- its definition or in one of its ancestors. (RM 3.7(10))
6451 if Nkind (Discriminant_Type (D)) = N_Access_Definition
6452 and then not Is_Concurrent_Type (Current_Scope)
6453 and then not Is_Concurrent_Record_Type (Current_Scope)
6454 and then not Is_Limited_Record (Current_Scope)
6455 and then Ekind (Current_Scope) /= E_Limited_Private_Type
6458 ("access discriminants allowed only for limited types", Loc);
6460 end Check_Access_Discriminant_Requires_Limited;
6462 -----------------------------------
6463 -- Check_Aliased_Component_Types --
6464 -----------------------------------
6466 procedure Check_Aliased_Component_Types (T : Entity_Id) is
6470 -- ??? Also need to check components of record extensions, but not
6471 -- components of protected types (which are always limited).
6473 if not Is_Limited_Type (T) then
6474 if Ekind (T) = E_Record_Type then
6475 C := First_Component (T);
6476 while Present (C) loop
6478 and then Has_Discriminants (Etype (C))
6479 and then not Is_Constrained (Etype (C))
6480 and then not In_Instance
6483 ("aliased component must be constrained ('R'M 3.6(11))",
6490 elsif Ekind (T) = E_Array_Type then
6491 if Has_Aliased_Components (T)
6492 and then Has_Discriminants (Component_Type (T))
6493 and then not Is_Constrained (Component_Type (T))
6494 and then not In_Instance
6497 ("aliased component type must be constrained ('R'M 3.6(11))",
6502 end Check_Aliased_Component_Types;
6504 ----------------------
6505 -- Check_Completion --
6506 ----------------------
6508 procedure Check_Completion (Body_Id : Node_Id := Empty) is
6511 procedure Post_Error;
6512 -- Post error message for lack of completion for entity E
6518 procedure Post_Error is
6520 if not Comes_From_Source (E) then
6522 if Ekind (E) = E_Task_Type
6523 or else Ekind (E) = E_Protected_Type
6525 -- It may be an anonymous protected type created for a
6526 -- single variable. Post error on variable, if present.
6532 Var := First_Entity (Current_Scope);
6534 while Present (Var) loop
6535 exit when Etype (Var) = E
6536 and then Comes_From_Source (Var);
6541 if Present (Var) then
6548 -- If a generated entity has no completion, then either previous
6549 -- semantic errors have disabled the expansion phase, or else we had
6550 -- missing subunits, or else we are compiling without expan- sion,
6551 -- or else something is very wrong.
6553 if not Comes_From_Source (E) then
6555 (Serious_Errors_Detected > 0
6556 or else Configurable_Run_Time_Violations > 0
6557 or else Subunits_Missing
6558 or else not Expander_Active);
6561 -- Here for source entity
6564 -- Here if no body to post the error message, so we post the error
6565 -- on the declaration that has no completion. This is not really
6566 -- the right place to post it, think about this later ???
6568 if No (Body_Id) then
6571 ("missing full declaration for }", Parent (E), E);
6574 ("missing body for &", Parent (E), E);
6577 -- Package body has no completion for a declaration that appears
6578 -- in the corresponding spec. Post error on the body, with a
6579 -- reference to the non-completed declaration.
6582 Error_Msg_Sloc := Sloc (E);
6586 ("missing full declaration for }!", Body_Id, E);
6588 elsif Is_Overloadable (E)
6589 and then Current_Entity_In_Scope (E) /= E
6591 -- It may be that the completion is mistyped and appears
6592 -- as a distinct overloading of the entity.
6595 Candidate : constant Entity_Id :=
6596 Current_Entity_In_Scope (E);
6597 Decl : constant Node_Id :=
6598 Unit_Declaration_Node (Candidate);
6601 if Is_Overloadable (Candidate)
6602 and then Ekind (Candidate) = Ekind (E)
6603 and then Nkind (Decl) = N_Subprogram_Body
6604 and then Acts_As_Spec (Decl)
6606 Check_Type_Conformant (Candidate, E);
6609 Error_Msg_NE ("missing body for & declared#!",
6614 Error_Msg_NE ("missing body for & declared#!",
6621 -- Start processing for Check_Completion
6624 E := First_Entity (Current_Scope);
6625 while Present (E) loop
6626 if Is_Intrinsic_Subprogram (E) then
6629 -- The following situation requires special handling: a child
6630 -- unit that appears in the context clause of the body of its
6633 -- procedure Parent.Child (...);
6635 -- with Parent.Child;
6636 -- package body Parent is
6638 -- Here Parent.Child appears as a local entity, but should not
6639 -- be flagged as requiring completion, because it is a
6640 -- compilation unit.
6642 elsif Ekind (E) = E_Function
6643 or else Ekind (E) = E_Procedure
6644 or else Ekind (E) = E_Generic_Function
6645 or else Ekind (E) = E_Generic_Procedure
6647 if not Has_Completion (E)
6648 and then not Is_Abstract (E)
6649 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
6651 and then Chars (E) /= Name_uSize
6656 elsif Is_Entry (E) then
6657 if not Has_Completion (E) and then
6658 (Ekind (Scope (E)) = E_Protected_Object
6659 or else Ekind (Scope (E)) = E_Protected_Type)
6664 elsif Is_Package (E) then
6665 if Unit_Requires_Body (E) then
6666 if not Has_Completion (E)
6667 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
6673 elsif not Is_Child_Unit (E) then
6674 May_Need_Implicit_Body (E);
6677 elsif Ekind (E) = E_Incomplete_Type
6678 and then No (Underlying_Type (E))
6682 elsif (Ekind (E) = E_Task_Type or else
6683 Ekind (E) = E_Protected_Type)
6684 and then not Has_Completion (E)
6688 -- A single task declared in the current scope is a constant, verify
6689 -- that the body of its anonymous type is in the same scope. If the
6690 -- task is defined elsewhere, this may be a renaming declaration for
6691 -- which no completion is needed.
6693 elsif Ekind (E) = E_Constant
6694 and then Ekind (Etype (E)) = E_Task_Type
6695 and then not Has_Completion (Etype (E))
6696 and then Scope (Etype (E)) = Current_Scope
6700 elsif Ekind (E) = E_Protected_Object
6701 and then not Has_Completion (Etype (E))
6705 elsif Ekind (E) = E_Record_Type then
6706 if Is_Tagged_Type (E) then
6707 Check_Abstract_Overriding (E);
6710 Check_Aliased_Component_Types (E);
6712 elsif Ekind (E) = E_Array_Type then
6713 Check_Aliased_Component_Types (E);
6719 end Check_Completion;
6721 ----------------------------
6722 -- Check_Delta_Expression --
6723 ----------------------------
6725 procedure Check_Delta_Expression (E : Node_Id) is
6727 if not (Is_Real_Type (Etype (E))) then
6728 Wrong_Type (E, Any_Real);
6730 elsif not Is_OK_Static_Expression (E) then
6731 Flag_Non_Static_Expr
6732 ("non-static expression used for delta value!", E);
6734 elsif not UR_Is_Positive (Expr_Value_R (E)) then
6735 Error_Msg_N ("delta expression must be positive", E);
6741 -- If any of above errors occurred, then replace the incorrect
6742 -- expression by the real 0.1, which should prevent further errors.
6745 Make_Real_Literal (Sloc (E), Ureal_Tenth));
6746 Analyze_And_Resolve (E, Standard_Float);
6747 end Check_Delta_Expression;
6749 -----------------------------
6750 -- Check_Digits_Expression --
6751 -----------------------------
6753 procedure Check_Digits_Expression (E : Node_Id) is
6755 if not (Is_Integer_Type (Etype (E))) then
6756 Wrong_Type (E, Any_Integer);
6758 elsif not Is_OK_Static_Expression (E) then
6759 Flag_Non_Static_Expr
6760 ("non-static expression used for digits value!", E);
6762 elsif Expr_Value (E) <= 0 then
6763 Error_Msg_N ("digits value must be greater than zero", E);
6769 -- If any of above errors occurred, then replace the incorrect
6770 -- expression by the integer 1, which should prevent further errors.
6772 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
6773 Analyze_And_Resolve (E, Standard_Integer);
6775 end Check_Digits_Expression;
6777 --------------------------
6778 -- Check_Initialization --
6779 --------------------------
6781 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
6783 if (Is_Limited_Type (T)
6784 or else Is_Limited_Composite (T))
6785 and then not In_Instance
6786 and then not In_Inlined_Body
6788 -- Ada 2005 (AI-287): Relax the strictness of the front-end in
6789 -- case of limited aggregates and extension aggregates.
6791 if Ada_Version >= Ada_05
6792 and then (Nkind (Exp) = N_Aggregate
6793 or else Nkind (Exp) = N_Extension_Aggregate)
6798 ("cannot initialize entities of limited type", Exp);
6799 Explain_Limited_Type (T, Exp);
6802 end Check_Initialization;
6804 ------------------------------------
6805 -- Check_Or_Process_Discriminants --
6806 ------------------------------------
6808 -- If an incomplete or private type declaration was already given for
6809 -- the type, the discriminants may have already been processed if they
6810 -- were present on the incomplete declaration. In this case a full
6811 -- conformance check is performed otherwise just process them.
6813 procedure Check_Or_Process_Discriminants
6816 Prev : Entity_Id := Empty)
6819 if Has_Discriminants (T) then
6821 -- Make the discriminants visible to component declarations
6824 D : Entity_Id := First_Discriminant (T);
6828 while Present (D) loop
6829 Prev := Current_Entity (D);
6830 Set_Current_Entity (D);
6831 Set_Is_Immediately_Visible (D);
6832 Set_Homonym (D, Prev);
6834 -- Ada 2005 (AI-230): Access discriminant allowed in
6835 -- non-limited record types.
6837 if Ada_Version < Ada_05 then
6839 -- This restriction gets applied to the full type here; it
6840 -- has already been applied earlier to the partial view
6842 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6845 Next_Discriminant (D);
6849 elsif Present (Discriminant_Specifications (N)) then
6850 Process_Discriminants (N, Prev);
6852 end Check_Or_Process_Discriminants;
6854 ----------------------
6855 -- Check_Real_Bound --
6856 ----------------------
6858 procedure Check_Real_Bound (Bound : Node_Id) is
6860 if not Is_Real_Type (Etype (Bound)) then
6862 ("bound in real type definition must be of real type", Bound);
6864 elsif not Is_OK_Static_Expression (Bound) then
6865 Flag_Non_Static_Expr
6866 ("non-static expression used for real type bound!", Bound);
6873 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6875 Resolve (Bound, Standard_Float);
6876 end Check_Real_Bound;
6878 ------------------------------
6879 -- Complete_Private_Subtype --
6880 ------------------------------
6882 procedure Complete_Private_Subtype
6885 Full_Base : Entity_Id;
6886 Related_Nod : Node_Id)
6888 Save_Next_Entity : Entity_Id;
6889 Save_Homonym : Entity_Id;
6892 -- Set semantic attributes for (implicit) private subtype completion.
6893 -- If the full type has no discriminants, then it is a copy of the full
6894 -- view of the base. Otherwise, it is a subtype of the base with a
6895 -- possible discriminant constraint. Save and restore the original
6896 -- Next_Entity field of full to ensure that the calls to Copy_Node
6897 -- do not corrupt the entity chain.
6899 -- Note that the type of the full view is the same entity as the
6900 -- type of the partial view. In this fashion, the subtype has
6901 -- access to the correct view of the parent.
6903 Save_Next_Entity := Next_Entity (Full);
6904 Save_Homonym := Homonym (Priv);
6906 case Ekind (Full_Base) is
6907 when E_Record_Type |
6913 Copy_Node (Priv, Full);
6915 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6916 Set_First_Entity (Full, First_Entity (Full_Base));
6917 Set_Last_Entity (Full, Last_Entity (Full_Base));
6920 Copy_Node (Full_Base, Full);
6921 Set_Chars (Full, Chars (Priv));
6922 Conditional_Delay (Full, Priv);
6923 Set_Sloc (Full, Sloc (Priv));
6926 Set_Next_Entity (Full, Save_Next_Entity);
6927 Set_Homonym (Full, Save_Homonym);
6928 Set_Associated_Node_For_Itype (Full, Related_Nod);
6930 -- Set common attributes for all subtypes
6932 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6934 -- The Etype of the full view is inconsistent. Gigi needs to see the
6935 -- structural full view, which is what the current scheme gives:
6936 -- the Etype of the full view is the etype of the full base. However,
6937 -- if the full base is a derived type, the full view then looks like
6938 -- a subtype of the parent, not a subtype of the full base. If instead
6941 -- Set_Etype (Full, Full_Base);
6943 -- then we get inconsistencies in the front-end (confusion between
6944 -- views). Several outstanding bugs are related to this ???
6946 Set_Is_First_Subtype (Full, False);
6947 Set_Scope (Full, Scope (Priv));
6948 Set_Size_Info (Full, Full_Base);
6949 Set_RM_Size (Full, RM_Size (Full_Base));
6950 Set_Is_Itype (Full);
6952 -- A subtype of a private-type-without-discriminants, whose full-view
6953 -- has discriminants with default expressions, is not constrained!
6955 if not Has_Discriminants (Priv) then
6956 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6958 if Has_Discriminants (Full_Base) then
6959 Set_Discriminant_Constraint
6960 (Full, Discriminant_Constraint (Full_Base));
6962 -- The partial view may have been indefinite, the full view
6965 Set_Has_Unknown_Discriminants
6966 (Full, Has_Unknown_Discriminants (Full_Base));
6970 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6971 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6973 -- Freeze the private subtype entity if its parent is delayed, and not
6974 -- already frozen. We skip this processing if the type is an anonymous
6975 -- subtype of a record component, or is the corresponding record of a
6976 -- protected type, since ???
6978 if not Is_Type (Scope (Full)) then
6979 Set_Has_Delayed_Freeze (Full,
6980 Has_Delayed_Freeze (Full_Base)
6981 and then (not Is_Frozen (Full_Base)));
6984 Set_Freeze_Node (Full, Empty);
6985 Set_Is_Frozen (Full, False);
6986 Set_Full_View (Priv, Full);
6988 if Has_Discriminants (Full) then
6989 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
6990 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
6992 if Has_Unknown_Discriminants (Full) then
6993 Set_Discriminant_Constraint (Full, No_Elist);
6997 if Ekind (Full_Base) = E_Record_Type
6998 and then Has_Discriminants (Full_Base)
6999 and then Has_Discriminants (Priv) -- might not, if errors
7000 and then not Has_Unknown_Discriminants (Priv)
7001 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
7003 Create_Constrained_Components
7004 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
7006 -- If the full base is itself derived from private, build a congruent
7007 -- subtype of its underlying type, for use by the back end. For a
7008 -- constrained record component, the declaration cannot be placed on
7009 -- the component list, but it must neverthess be built an analyzed, to
7010 -- supply enough information for gigi to compute the size of component.
7012 elsif Ekind (Full_Base) in Private_Kind
7013 and then Is_Derived_Type (Full_Base)
7014 and then Has_Discriminants (Full_Base)
7015 and then (Ekind (Current_Scope) /= E_Record_Subtype)
7017 if not Is_Itype (Priv)
7019 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
7021 Build_Underlying_Full_View
7022 (Parent (Priv), Full, Etype (Full_Base));
7024 elsif Nkind (Related_Nod) = N_Component_Declaration then
7025 Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
7028 elsif Is_Record_Type (Full_Base) then
7030 -- Show Full is simply a renaming of Full_Base
7032 Set_Cloned_Subtype (Full, Full_Base);
7035 -- It is unsafe to share to bounds of a scalar type, because the Itype
7036 -- is elaborated on demand, and if a bound is non-static then different
7037 -- orders of elaboration in different units will lead to different
7038 -- external symbols.
7040 if Is_Scalar_Type (Full_Base) then
7041 Set_Scalar_Range (Full,
7042 Make_Range (Sloc (Related_Nod),
7044 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
7046 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
7048 -- This completion inherits the bounds of the full parent, but if
7049 -- the parent is an unconstrained floating point type, so is the
7052 if Is_Floating_Point_Type (Full_Base) then
7053 Set_Includes_Infinities
7054 (Scalar_Range (Full), Has_Infinities (Full_Base));
7058 -- ??? It seems that a lot of fields are missing that should be copied
7059 -- from Full_Base to Full. Here are some that are introduced in a
7060 -- non-disruptive way but a cleanup is necessary.
7062 if Is_Tagged_Type (Full_Base) then
7063 Set_Is_Tagged_Type (Full);
7064 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
7065 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
7067 -- If this is a subtype of a protected or task type, constrain its
7068 -- corresponding record, unless this is a subtype without constraints,
7069 -- i.e. a simple renaming as with an actual subtype in an instance.
7071 elsif Is_Concurrent_Type (Full_Base) then
7072 if Has_Discriminants (Full)
7073 and then Present (Corresponding_Record_Type (Full_Base))
7075 not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
7077 Set_Corresponding_Record_Type (Full,
7078 Constrain_Corresponding_Record
7079 (Full, Corresponding_Record_Type (Full_Base),
7080 Related_Nod, Full_Base));
7083 Set_Corresponding_Record_Type (Full,
7084 Corresponding_Record_Type (Full_Base));
7087 end Complete_Private_Subtype;
7089 ----------------------------
7090 -- Constant_Redeclaration --
7091 ----------------------------
7093 procedure Constant_Redeclaration
7098 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
7099 Obj_Def : constant Node_Id := Object_Definition (N);
7102 procedure Check_Recursive_Declaration (Typ : Entity_Id);
7103 -- If deferred constant is an access type initialized with an
7104 -- allocator, check whether there is an illegal recursion in the
7105 -- definition, through a default value of some record subcomponent.
7106 -- This is normally detected when generating init procs, but requires
7107 -- this additional mechanism when expansion is disabled.
7109 ---------------------------------
7110 -- Check_Recursive_Declaration --
7111 ---------------------------------
7113 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
7117 if Is_Record_Type (Typ) then
7118 Comp := First_Component (Typ);
7119 while Present (Comp) loop
7120 if Comes_From_Source (Comp) then
7121 if Present (Expression (Parent (Comp)))
7122 and then Is_Entity_Name (Expression (Parent (Comp)))
7123 and then Entity (Expression (Parent (Comp))) = Prev
7125 Error_Msg_Sloc := Sloc (Parent (Comp));
7127 ("illegal circularity with declaration for&#",
7131 elsif Is_Record_Type (Etype (Comp)) then
7132 Check_Recursive_Declaration (Etype (Comp));
7136 Next_Component (Comp);
7139 end Check_Recursive_Declaration;
7141 -- Start of processing for Constant_Redeclaration
7144 if Nkind (Parent (Prev)) = N_Object_Declaration then
7145 if Nkind (Object_Definition
7146 (Parent (Prev))) = N_Subtype_Indication
7148 -- Find type of new declaration. The constraints of the two
7149 -- views must match statically, but there is no point in
7150 -- creating an itype for the full view.
7152 if Nkind (Obj_Def) = N_Subtype_Indication then
7153 Find_Type (Subtype_Mark (Obj_Def));
7154 New_T := Entity (Subtype_Mark (Obj_Def));
7157 Find_Type (Obj_Def);
7158 New_T := Entity (Obj_Def);
7164 -- The full view may impose a constraint, even if the partial
7165 -- view does not, so construct the subtype.
7167 New_T := Find_Type_Of_Object (Obj_Def, N);
7172 -- Current declaration is illegal, diagnosed below in Enter_Name
7178 -- If previous full declaration exists, or if a homograph is present,
7179 -- let Enter_Name handle it, either with an error, or with the removal
7180 -- of an overridden implicit subprogram.
7182 if Ekind (Prev) /= E_Constant
7183 or else Present (Expression (Parent (Prev)))
7184 or else Present (Full_View (Prev))
7188 -- Verify that types of both declarations match
7190 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
7191 Error_Msg_Sloc := Sloc (Prev);
7192 Error_Msg_N ("type does not match declaration#", N);
7193 Set_Full_View (Prev, Id);
7194 Set_Etype (Id, Any_Type);
7196 -- If so, process the full constant declaration
7199 Set_Full_View (Prev, Id);
7200 Set_Is_Public (Id, Is_Public (Prev));
7201 Set_Is_Internal (Id);
7202 Append_Entity (Id, Current_Scope);
7204 -- Check ALIASED present if present before (RM 7.4(7))
7206 if Is_Aliased (Prev)
7207 and then not Aliased_Present (N)
7209 Error_Msg_Sloc := Sloc (Prev);
7210 Error_Msg_N ("ALIASED required (see declaration#)", N);
7213 -- Check that placement is in private part and that the incomplete
7214 -- declaration appeared in the visible part.
7216 if Ekind (Current_Scope) = E_Package
7217 and then not In_Private_Part (Current_Scope)
7219 Error_Msg_Sloc := Sloc (Prev);
7220 Error_Msg_N ("full constant for declaration#"
7221 & " must be in private part", N);
7223 elsif Ekind (Current_Scope) = E_Package
7224 and then List_Containing (Parent (Prev))
7225 /= Visible_Declarations
7226 (Specification (Unit_Declaration_Node (Current_Scope)))
7229 ("deferred constant must be declared in visible part",
7233 if Is_Access_Type (T)
7234 and then Nkind (Expression (N)) = N_Allocator
7236 Check_Recursive_Declaration (Designated_Type (T));
7239 end Constant_Redeclaration;
7241 ----------------------
7242 -- Constrain_Access --
7243 ----------------------
7245 procedure Constrain_Access
7246 (Def_Id : in out Entity_Id;
7248 Related_Nod : Node_Id)
7250 T : constant Entity_Id := Entity (Subtype_Mark (S));
7251 Desig_Type : constant Entity_Id := Designated_Type (T);
7252 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
7253 Constraint_OK : Boolean := True;
7256 if Is_Array_Type (Desig_Type) then
7257 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
7259 elsif (Is_Record_Type (Desig_Type)
7260 or else Is_Incomplete_Or_Private_Type (Desig_Type))
7261 and then not Is_Constrained (Desig_Type)
7263 -- ??? The following code is a temporary kludge to ignore a
7264 -- discriminant constraint on access type if it is constraining
7265 -- the current record. Avoid creating the implicit subtype of the
7266 -- record we are currently compiling since right now, we cannot
7267 -- handle these. For now, just return the access type itself.
7269 if Desig_Type = Current_Scope
7270 and then No (Def_Id)
7272 Set_Ekind (Desig_Subtype, E_Record_Subtype);
7273 Def_Id := Entity (Subtype_Mark (S));
7275 -- This call added to ensure that the constraint is analyzed
7276 -- (needed for a B test). Note that we still return early from
7277 -- this procedure to avoid recursive processing. ???
7279 Constrain_Discriminated_Type
7280 (Desig_Subtype, S, Related_Nod, For_Access => True);
7284 if Ekind (T) = E_General_Access_Type
7285 and then Has_Private_Declaration (Desig_Type)
7286 and then In_Open_Scopes (Scope (Desig_Type))
7288 -- Enforce rule that the constraint is illegal if there is
7289 -- an unconstrained view of the designated type. This means
7290 -- that the partial view (either a private type declaration or
7291 -- a derivation from a private type) has no discriminants.
7292 -- (Defect Report 8652/0008, Technical Corrigendum 1, checked
7293 -- by ACATS B371001).
7296 Pack : constant Node_Id :=
7297 Unit_Declaration_Node (Scope (Desig_Type));
7302 if Nkind (Pack) = N_Package_Declaration then
7303 Decls := Visible_Declarations (Specification (Pack));
7304 Decl := First (Decls);
7305 while Present (Decl) loop
7306 if (Nkind (Decl) = N_Private_Type_Declaration
7308 Chars (Defining_Identifier (Decl)) =
7312 (Nkind (Decl) = N_Full_Type_Declaration
7314 Chars (Defining_Identifier (Decl)) =
7316 and then Is_Derived_Type (Desig_Type)
7318 Has_Private_Declaration (Etype (Desig_Type)))
7320 if No (Discriminant_Specifications (Decl)) then
7322 ("cannot constrain general access type " &
7323 "if designated type has unconstrained view", S);
7335 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
7336 For_Access => True);
7338 elsif (Is_Task_Type (Desig_Type)
7339 or else Is_Protected_Type (Desig_Type))
7340 and then not Is_Constrained (Desig_Type)
7342 Constrain_Concurrent
7343 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
7346 Error_Msg_N ("invalid constraint on access type", S);
7347 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
7348 Constraint_OK := False;
7352 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
7354 Set_Ekind (Def_Id, E_Access_Subtype);
7357 if Constraint_OK then
7358 Set_Etype (Def_Id, Base_Type (T));
7360 if Is_Private_Type (Desig_Type) then
7361 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
7364 Set_Etype (Def_Id, Any_Type);
7367 Set_Size_Info (Def_Id, T);
7368 Set_Is_Constrained (Def_Id, Constraint_OK);
7369 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
7370 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7371 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
7373 -- Itypes created for constrained record components do not receive
7374 -- a freeze node, they are elaborated when first seen.
7376 if not Is_Record_Type (Current_Scope) then
7377 Conditional_Delay (Def_Id, T);
7379 end Constrain_Access;
7381 ---------------------
7382 -- Constrain_Array --
7383 ---------------------
7385 procedure Constrain_Array
7386 (Def_Id : in out Entity_Id;
7388 Related_Nod : Node_Id;
7389 Related_Id : Entity_Id;
7392 C : constant Node_Id := Constraint (SI);
7393 Number_Of_Constraints : Nat := 0;
7396 Constraint_OK : Boolean := True;
7399 T := Entity (Subtype_Mark (SI));
7401 if Ekind (T) in Access_Kind then
7402 T := Designated_Type (T);
7405 -- If an index constraint follows a subtype mark in a subtype indication
7406 -- then the type or subtype denoted by the subtype mark must not already
7407 -- impose an index constraint. The subtype mark must denote either an
7408 -- unconstrained array type or an access type whose designated type
7409 -- is such an array type... (RM 3.6.1)
7411 if Is_Constrained (T) then
7413 ("array type is already constrained", Subtype_Mark (SI));
7414 Constraint_OK := False;
7417 S := First (Constraints (C));
7419 while Present (S) loop
7420 Number_Of_Constraints := Number_Of_Constraints + 1;
7424 -- In either case, the index constraint must provide a discrete
7425 -- range for each index of the array type and the type of each
7426 -- discrete range must be the same as that of the corresponding
7427 -- index. (RM 3.6.1)
7429 if Number_Of_Constraints /= Number_Dimensions (T) then
7430 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
7431 Constraint_OK := False;
7434 S := First (Constraints (C));
7435 Index := First_Index (T);
7438 -- Apply constraints to each index type
7440 for J in 1 .. Number_Of_Constraints loop
7441 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
7451 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
7452 Set_Parent (Def_Id, Related_Nod);
7455 Set_Ekind (Def_Id, E_Array_Subtype);
7458 Set_Size_Info (Def_Id, (T));
7459 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7460 Set_Etype (Def_Id, Base_Type (T));
7462 if Constraint_OK then
7463 Set_First_Index (Def_Id, First (Constraints (C)));
7466 Set_Is_Constrained (Def_Id, True);
7467 Set_Is_Aliased (Def_Id, Is_Aliased (T));
7468 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7470 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
7471 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
7473 -- If the subtype is not that of a record component, build a freeze
7474 -- node if parent still needs one.
7476 -- If the subtype is not that of a record component, make sure
7477 -- that the Depends_On_Private status is set (explanation ???)
7478 -- and also that a conditional delay is set.
7480 if not Is_Type (Scope (Def_Id)) then
7481 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
7482 Conditional_Delay (Def_Id, T);
7485 end Constrain_Array;
7487 ------------------------------
7488 -- Constrain_Component_Type --
7489 ------------------------------
7491 function Constrain_Component_Type
7492 (Compon_Type : Entity_Id;
7493 Constrained_Typ : Entity_Id;
7494 Related_Node : Node_Id;
7496 Constraints : Elist_Id) return Entity_Id
7498 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
7500 function Build_Constrained_Array_Type
7501 (Old_Type : Entity_Id) return Entity_Id;
7502 -- If Old_Type is an array type, one of whose indices is constrained
7503 -- by a discriminant, build an Itype whose constraint replaces the
7504 -- discriminant with its value in the constraint.
7506 function Build_Constrained_Discriminated_Type
7507 (Old_Type : Entity_Id) return Entity_Id;
7508 -- Ditto for record components
7510 function Build_Constrained_Access_Type
7511 (Old_Type : Entity_Id) return Entity_Id;
7512 -- Ditto for access types. Makes use of previous two functions, to
7513 -- constrain designated type.
7515 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
7516 -- T is an array or discriminated type, C is a list of constraints
7517 -- that apply to T. This routine builds the constrained subtype.
7519 function Is_Discriminant (Expr : Node_Id) return Boolean;
7520 -- Returns True if Expr is a discriminant
7522 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
7523 -- Find the value of discriminant Discrim in Constraint
7525 -----------------------------------
7526 -- Build_Constrained_Access_Type --
7527 -----------------------------------
7529 function Build_Constrained_Access_Type
7530 (Old_Type : Entity_Id) return Entity_Id
7532 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
7534 Desig_Subtype : Entity_Id;
7538 -- if the original access type was not embedded in the enclosing
7539 -- type definition, there is no need to produce a new access
7540 -- subtype. In fact every access type with an explicit constraint
7541 -- generates an itype whose scope is the enclosing record.
7543 if not Is_Type (Scope (Old_Type)) then
7546 elsif Is_Array_Type (Desig_Type) then
7547 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
7549 elsif Has_Discriminants (Desig_Type) then
7551 -- This may be an access type to an enclosing record type for
7552 -- which we are constructing the constrained components. Return
7553 -- the enclosing record subtype. This is not always correct,
7554 -- but avoids infinite recursion. ???
7556 Desig_Subtype := Any_Type;
7558 for J in reverse 0 .. Scope_Stack.Last loop
7559 Scop := Scope_Stack.Table (J).Entity;
7562 and then Base_Type (Scop) = Base_Type (Desig_Type)
7564 Desig_Subtype := Scop;
7567 exit when not Is_Type (Scop);
7570 if Desig_Subtype = Any_Type then
7572 Build_Constrained_Discriminated_Type (Desig_Type);
7579 if Desig_Subtype /= Desig_Type then
7581 -- The Related_Node better be here or else we won't be able
7582 -- to attach new itypes to a node in the tree.
7584 pragma Assert (Present (Related_Node));
7586 Itype := Create_Itype (E_Access_Subtype, Related_Node);
7588 Set_Etype (Itype, Base_Type (Old_Type));
7589 Set_Size_Info (Itype, (Old_Type));
7590 Set_Directly_Designated_Type (Itype, Desig_Subtype);
7591 Set_Depends_On_Private (Itype, Has_Private_Component
7593 Set_Is_Access_Constant (Itype, Is_Access_Constant
7596 -- The new itype needs freezing when it depends on a not frozen
7597 -- type and the enclosing subtype needs freezing.
7599 if Has_Delayed_Freeze (Constrained_Typ)
7600 and then not Is_Frozen (Constrained_Typ)
7602 Conditional_Delay (Itype, Base_Type (Old_Type));
7610 end Build_Constrained_Access_Type;
7612 ----------------------------------
7613 -- Build_Constrained_Array_Type --
7614 ----------------------------------
7616 function Build_Constrained_Array_Type
7617 (Old_Type : Entity_Id) return Entity_Id
7621 Old_Index : Node_Id;
7622 Range_Node : Node_Id;
7623 Constr_List : List_Id;
7625 Need_To_Create_Itype : Boolean := False;
7628 Old_Index := First_Index (Old_Type);
7629 while Present (Old_Index) loop
7630 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
7632 if Is_Discriminant (Lo_Expr)
7633 or else Is_Discriminant (Hi_Expr)
7635 Need_To_Create_Itype := True;
7638 Next_Index (Old_Index);
7641 if Need_To_Create_Itype then
7642 Constr_List := New_List;
7644 Old_Index := First_Index (Old_Type);
7645 while Present (Old_Index) loop
7646 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
7648 if Is_Discriminant (Lo_Expr) then
7649 Lo_Expr := Get_Discr_Value (Lo_Expr);
7652 if Is_Discriminant (Hi_Expr) then
7653 Hi_Expr := Get_Discr_Value (Hi_Expr);
7658 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
7660 Append (Range_Node, To => Constr_List);
7662 Next_Index (Old_Index);
7665 return Build_Subtype (Old_Type, Constr_List);
7670 end Build_Constrained_Array_Type;
7672 ------------------------------------------
7673 -- Build_Constrained_Discriminated_Type --
7674 ------------------------------------------
7676 function Build_Constrained_Discriminated_Type
7677 (Old_Type : Entity_Id) return Entity_Id
7680 Constr_List : List_Id;
7681 Old_Constraint : Elmt_Id;
7683 Need_To_Create_Itype : Boolean := False;
7686 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
7687 while Present (Old_Constraint) loop
7688 Expr := Node (Old_Constraint);
7690 if Is_Discriminant (Expr) then
7691 Need_To_Create_Itype := True;
7694 Next_Elmt (Old_Constraint);
7697 if Need_To_Create_Itype then
7698 Constr_List := New_List;
7700 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
7701 while Present (Old_Constraint) loop
7702 Expr := Node (Old_Constraint);
7704 if Is_Discriminant (Expr) then
7705 Expr := Get_Discr_Value (Expr);
7708 Append (New_Copy_Tree (Expr), To => Constr_List);
7710 Next_Elmt (Old_Constraint);
7713 return Build_Subtype (Old_Type, Constr_List);
7718 end Build_Constrained_Discriminated_Type;
7724 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
7726 Subtyp_Decl : Node_Id;
7728 Btyp : Entity_Id := Base_Type (T);
7731 -- The Related_Node better be here or else we won't be able to
7732 -- attach new itypes to a node in the tree.
7734 pragma Assert (Present (Related_Node));
7736 -- If the view of the component's type is incomplete or private
7737 -- with unknown discriminants, then the constraint must be applied
7738 -- to the full type.
7740 if Has_Unknown_Discriminants (Btyp)
7741 and then Present (Underlying_Type (Btyp))
7743 Btyp := Underlying_Type (Btyp);
7747 Make_Subtype_Indication (Loc,
7748 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7749 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
7751 Def_Id := Create_Itype (Ekind (T), Related_Node);
7754 Make_Subtype_Declaration (Loc,
7755 Defining_Identifier => Def_Id,
7756 Subtype_Indication => Indic);
7758 Set_Parent (Subtyp_Decl, Parent (Related_Node));
7760 -- Itypes must be analyzed with checks off (see package Itypes)
7762 Analyze (Subtyp_Decl, Suppress => All_Checks);
7767 ---------------------
7768 -- Get_Discr_Value --
7769 ---------------------
7771 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
7772 D : Entity_Id := First_Discriminant (Typ);
7773 E : Elmt_Id := First_Elmt (Constraints);
7777 -- The discriminant may be declared for the type, in which case we
7778 -- find it by iterating over the list of discriminants. If the
7779 -- discriminant is inherited from a parent type, it appears as the
7780 -- corresponding discriminant of the current type. This will be the
7781 -- case when constraining an inherited component whose constraint is
7782 -- given by a discriminant of the parent.
7784 while Present (D) loop
7785 if D = Entity (Discrim)
7786 or else Corresponding_Discriminant (D) = Entity (Discrim)
7791 Next_Discriminant (D);
7795 -- The corresponding_Discriminant mechanism is incomplete, because
7796 -- the correspondence between new and old discriminants is not one
7797 -- to one: one new discriminant can constrain several old ones. In
7798 -- that case, scan sequentially the stored_constraint, the list of
7799 -- discriminants of the parents, and the constraints.
7801 if Is_Derived_Type (Typ)
7802 and then Present (Stored_Constraint (Typ))
7803 and then Scope (Entity (Discrim)) = Etype (Typ)
7805 D := First_Discriminant (Etype (Typ));
7806 E := First_Elmt (Constraints);
7807 G := First_Elmt (Stored_Constraint (Typ));
7809 while Present (D) loop
7810 if D = Entity (Discrim) then
7814 Next_Discriminant (D);
7820 -- Something is wrong if we did not find the value
7822 raise Program_Error;
7823 end Get_Discr_Value;
7825 ---------------------
7826 -- Is_Discriminant --
7827 ---------------------
7829 function Is_Discriminant (Expr : Node_Id) return Boolean is
7830 Discrim_Scope : Entity_Id;
7833 if Denotes_Discriminant (Expr) then
7834 Discrim_Scope := Scope (Entity (Expr));
7836 -- Either we have a reference to one of Typ's discriminants,
7838 pragma Assert (Discrim_Scope = Typ
7840 -- or to the discriminants of the parent type, in the case
7841 -- of a derivation of a tagged type with variants.
7843 or else Discrim_Scope = Etype (Typ)
7844 or else Full_View (Discrim_Scope) = Etype (Typ)
7846 -- or same as above for the case where the discriminants
7847 -- were declared in Typ's private view.
7849 or else (Is_Private_Type (Discrim_Scope)
7850 and then Chars (Discrim_Scope) = Chars (Typ))
7852 -- or else we are deriving from the full view and the
7853 -- discriminant is declared in the private entity.
7855 or else (Is_Private_Type (Typ)
7856 and then Chars (Discrim_Scope) = Chars (Typ))
7858 -- or we have a class-wide type, in which case make sure the
7859 -- discriminant found belongs to the root type.
7861 or else (Is_Class_Wide_Type (Typ)
7862 and then Etype (Typ) = Discrim_Scope));
7867 -- In all other cases we have something wrong
7870 end Is_Discriminant;
7872 -- Start of processing for Constrain_Component_Type
7875 if Is_Array_Type (Compon_Type) then
7876 return Build_Constrained_Array_Type (Compon_Type);
7878 elsif Has_Discriminants (Compon_Type) then
7879 return Build_Constrained_Discriminated_Type (Compon_Type);
7881 elsif Is_Access_Type (Compon_Type) then
7882 return Build_Constrained_Access_Type (Compon_Type);
7886 end Constrain_Component_Type;
7888 --------------------------
7889 -- Constrain_Concurrent --
7890 --------------------------
7892 -- For concurrent types, the associated record value type carries the same
7893 -- discriminants, so when we constrain a concurrent type, we must constrain
7894 -- the value type as well.
7896 procedure Constrain_Concurrent
7897 (Def_Id : in out Entity_Id;
7899 Related_Nod : Node_Id;
7900 Related_Id : Entity_Id;
7903 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
7907 if Ekind (T_Ent) in Access_Kind then
7908 T_Ent := Designated_Type (T_Ent);
7911 T_Val := Corresponding_Record_Type (T_Ent);
7913 if Present (T_Val) then
7916 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7919 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7921 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7922 Set_Corresponding_Record_Type (Def_Id,
7923 Constrain_Corresponding_Record
7924 (Def_Id, T_Val, Related_Nod, Related_Id));
7927 -- If there is no associated record, expansion is disabled and this
7928 -- is a generic context. Create a subtype in any case, so that
7929 -- semantic analysis can proceed.
7932 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7935 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7937 end Constrain_Concurrent;
7939 ------------------------------------
7940 -- Constrain_Corresponding_Record --
7941 ------------------------------------
7943 function Constrain_Corresponding_Record
7944 (Prot_Subt : Entity_Id;
7945 Corr_Rec : Entity_Id;
7946 Related_Nod : Node_Id;
7947 Related_Id : Entity_Id) return Entity_Id
7949 T_Sub : constant Entity_Id :=
7950 Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
7953 Set_Etype (T_Sub, Corr_Rec);
7954 Init_Size_Align (T_Sub);
7955 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
7956 Set_Is_Constrained (T_Sub, True);
7957 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
7958 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
7960 Conditional_Delay (T_Sub, Corr_Rec);
7962 if Has_Discriminants (Prot_Subt) then -- False only if errors.
7963 Set_Discriminant_Constraint
7964 (T_Sub, Discriminant_Constraint (Prot_Subt));
7965 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
7966 Create_Constrained_Components
7967 (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
7970 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
7973 end Constrain_Corresponding_Record;
7975 -----------------------
7976 -- Constrain_Decimal --
7977 -----------------------
7979 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
7980 T : constant Entity_Id := Entity (Subtype_Mark (S));
7981 C : constant Node_Id := Constraint (S);
7982 Loc : constant Source_Ptr := Sloc (C);
7983 Range_Expr : Node_Id;
7984 Digits_Expr : Node_Id;
7989 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7991 if Nkind (C) = N_Range_Constraint then
7992 Range_Expr := Range_Expression (C);
7993 Digits_Val := Digits_Value (T);
7996 pragma Assert (Nkind (C) = N_Digits_Constraint);
7997 Digits_Expr := Digits_Expression (C);
7998 Analyze_And_Resolve (Digits_Expr, Any_Integer);
8000 Check_Digits_Expression (Digits_Expr);
8001 Digits_Val := Expr_Value (Digits_Expr);
8003 if Digits_Val > Digits_Value (T) then
8005 ("digits expression is incompatible with subtype", C);
8006 Digits_Val := Digits_Value (T);
8009 if Present (Range_Constraint (C)) then
8010 Range_Expr := Range_Expression (Range_Constraint (C));
8012 Range_Expr := Empty;
8016 Set_Etype (Def_Id, Base_Type (T));
8017 Set_Size_Info (Def_Id, (T));
8018 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8019 Set_Delta_Value (Def_Id, Delta_Value (T));
8020 Set_Scale_Value (Def_Id, Scale_Value (T));
8021 Set_Small_Value (Def_Id, Small_Value (T));
8022 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
8023 Set_Digits_Value (Def_Id, Digits_Val);
8025 -- Manufacture range from given digits value if no range present
8027 if No (Range_Expr) then
8028 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
8032 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
8034 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
8037 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
8038 Set_Discrete_RM_Size (Def_Id);
8040 -- Unconditionally delay the freeze, since we cannot set size
8041 -- information in all cases correctly until the freeze point.
8043 Set_Has_Delayed_Freeze (Def_Id);
8044 end Constrain_Decimal;
8046 ----------------------------------
8047 -- Constrain_Discriminated_Type --
8048 ----------------------------------
8050 procedure Constrain_Discriminated_Type
8051 (Def_Id : Entity_Id;
8053 Related_Nod : Node_Id;
8054 For_Access : Boolean := False)
8056 E : constant Entity_Id := Entity (Subtype_Mark (S));
8059 Elist : Elist_Id := New_Elmt_List;
8061 procedure Fixup_Bad_Constraint;
8062 -- This is called after finding a bad constraint, and after having
8063 -- posted an appropriate error message. The mission is to leave the
8064 -- entity T in as reasonable state as possible!
8066 --------------------------
8067 -- Fixup_Bad_Constraint --
8068 --------------------------
8070 procedure Fixup_Bad_Constraint is
8072 -- Set a reasonable Ekind for the entity. For an incomplete type,
8073 -- we can't do much, but for other types, we can set the proper
8074 -- corresponding subtype kind.
8076 if Ekind (T) = E_Incomplete_Type then
8077 Set_Ekind (Def_Id, Ekind (T));
8079 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
8082 Set_Etype (Def_Id, Any_Type);
8083 Set_Error_Posted (Def_Id);
8084 end Fixup_Bad_Constraint;
8086 -- Start of processing for Constrain_Discriminated_Type
8089 C := Constraint (S);
8091 -- A discriminant constraint is only allowed in a subtype indication,
8092 -- after a subtype mark. This subtype mark must denote either a type
8093 -- with discriminants, or an access type whose designated type is a
8094 -- type with discriminants. A discriminant constraint specifies the
8095 -- values of these discriminants (RM 3.7.2(5)).
8097 T := Base_Type (Entity (Subtype_Mark (S)));
8099 if Ekind (T) in Access_Kind then
8100 T := Designated_Type (T);
8103 -- Check that the type has visible discriminants. The type may be
8104 -- a private type with unknown discriminants whose full view has
8105 -- discriminants which are invisible.
8107 if not Has_Discriminants (T)
8109 (Has_Unknown_Discriminants (T)
8110 and then Is_Private_Type (T))
8112 Error_Msg_N ("invalid constraint: type has no discriminant", C);
8113 Fixup_Bad_Constraint;
8116 elsif Is_Constrained (E)
8117 or else (Ekind (E) = E_Class_Wide_Subtype
8118 and then Present (Discriminant_Constraint (E)))
8120 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
8121 Fixup_Bad_Constraint;
8125 -- T may be an unconstrained subtype (e.g. a generic actual).
8126 -- Constraint applies to the base type.
8130 Elist := Build_Discriminant_Constraints (T, S);
8132 -- If the list returned was empty we had an error in building the
8133 -- discriminant constraint. We have also already signalled an error
8134 -- in the incomplete type case
8136 if Is_Empty_Elmt_List (Elist) then
8137 Fixup_Bad_Constraint;
8141 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
8142 end Constrain_Discriminated_Type;
8144 ---------------------------
8145 -- Constrain_Enumeration --
8146 ---------------------------
8148 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
8149 T : constant Entity_Id := Entity (Subtype_Mark (S));
8150 C : constant Node_Id := Constraint (S);
8153 Set_Ekind (Def_Id, E_Enumeration_Subtype);
8155 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
8157 Set_Etype (Def_Id, Base_Type (T));
8158 Set_Size_Info (Def_Id, (T));
8159 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8160 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
8162 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8164 Set_Discrete_RM_Size (Def_Id);
8165 end Constrain_Enumeration;
8167 ----------------------
8168 -- Constrain_Float --
8169 ----------------------
8171 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
8172 T : constant Entity_Id := Entity (Subtype_Mark (S));
8178 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
8180 Set_Etype (Def_Id, Base_Type (T));
8181 Set_Size_Info (Def_Id, (T));
8182 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8184 -- Process the constraint
8186 C := Constraint (S);
8188 -- Digits constraint present
8190 if Nkind (C) = N_Digits_Constraint then
8191 Check_Restriction (No_Obsolescent_Features, C);
8193 if Warn_On_Obsolescent_Feature then
8195 ("subtype digits constraint is an " &
8196 "obsolescent feature ('R'M 'J.3(8))?", C);
8199 D := Digits_Expression (C);
8200 Analyze_And_Resolve (D, Any_Integer);
8201 Check_Digits_Expression (D);
8202 Set_Digits_Value (Def_Id, Expr_Value (D));
8204 -- Check that digits value is in range. Obviously we can do this
8205 -- at compile time, but it is strictly a runtime check, and of
8206 -- course there is an ACVC test that checks this!
8208 if Digits_Value (Def_Id) > Digits_Value (T) then
8209 Error_Msg_Uint_1 := Digits_Value (T);
8210 Error_Msg_N ("?digits value is too large, maximum is ^", D);
8212 Make_Raise_Constraint_Error (Sloc (D),
8213 Reason => CE_Range_Check_Failed);
8214 Insert_Action (Declaration_Node (Def_Id), Rais);
8217 C := Range_Constraint (C);
8219 -- No digits constraint present
8222 Set_Digits_Value (Def_Id, Digits_Value (T));
8225 -- Range constraint present
8227 if Nkind (C) = N_Range_Constraint then
8228 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8230 -- No range constraint present
8233 pragma Assert (No (C));
8234 Set_Scalar_Range (Def_Id, Scalar_Range (T));
8237 Set_Is_Constrained (Def_Id);
8238 end Constrain_Float;
8240 ---------------------
8241 -- Constrain_Index --
8242 ---------------------
8244 procedure Constrain_Index
8247 Related_Nod : Node_Id;
8248 Related_Id : Entity_Id;
8253 R : Node_Id := Empty;
8254 T : constant Entity_Id := Etype (Index);
8257 if Nkind (S) = N_Range
8259 (Nkind (S) = N_Attribute_Reference
8260 and then Attribute_Name (S) = Name_Range)
8262 -- A Range attribute will transformed into N_Range by Resolve
8268 Process_Range_Expr_In_Decl (R, T, Empty_List);
8270 if not Error_Posted (S)
8272 (Nkind (S) /= N_Range
8273 or else not Covers (T, (Etype (Low_Bound (S))))
8274 or else not Covers (T, (Etype (High_Bound (S)))))
8276 if Base_Type (T) /= Any_Type
8277 and then Etype (Low_Bound (S)) /= Any_Type
8278 and then Etype (High_Bound (S)) /= Any_Type
8280 Error_Msg_N ("range expected", S);
8284 elsif Nkind (S) = N_Subtype_Indication then
8286 -- The parser has verified that this is a discrete indication
8288 Resolve_Discrete_Subtype_Indication (S, T);
8289 R := Range_Expression (Constraint (S));
8291 elsif Nkind (S) = N_Discriminant_Association then
8293 -- Syntactically valid in subtype indication
8295 Error_Msg_N ("invalid index constraint", S);
8296 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
8299 -- Subtype_Mark case, no anonymous subtypes to construct
8304 if Is_Entity_Name (S) then
8305 if not Is_Type (Entity (S)) then
8306 Error_Msg_N ("expect subtype mark for index constraint", S);
8308 elsif Base_Type (Entity (S)) /= Base_Type (T) then
8309 Wrong_Type (S, Base_Type (T));
8315 Error_Msg_N ("invalid index constraint", S);
8316 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
8322 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
8324 Set_Etype (Def_Id, Base_Type (T));
8326 if Is_Modular_Integer_Type (T) then
8327 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
8329 elsif Is_Integer_Type (T) then
8330 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
8333 Set_Ekind (Def_Id, E_Enumeration_Subtype);
8334 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
8337 Set_Size_Info (Def_Id, (T));
8338 Set_RM_Size (Def_Id, RM_Size (T));
8339 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8341 Set_Scalar_Range (Def_Id, R);
8343 Set_Etype (S, Def_Id);
8344 Set_Discrete_RM_Size (Def_Id);
8345 end Constrain_Index;
8347 -----------------------
8348 -- Constrain_Integer --
8349 -----------------------
8351 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
8352 T : constant Entity_Id := Entity (Subtype_Mark (S));
8353 C : constant Node_Id := Constraint (S);
8356 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8358 if Is_Modular_Integer_Type (T) then
8359 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
8361 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
8364 Set_Etype (Def_Id, Base_Type (T));
8365 Set_Size_Info (Def_Id, (T));
8366 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8367 Set_Discrete_RM_Size (Def_Id);
8368 end Constrain_Integer;
8370 ------------------------------
8371 -- Constrain_Ordinary_Fixed --
8372 ------------------------------
8374 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
8375 T : constant Entity_Id := Entity (Subtype_Mark (S));
8381 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
8382 Set_Etype (Def_Id, Base_Type (T));
8383 Set_Size_Info (Def_Id, (T));
8384 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8385 Set_Small_Value (Def_Id, Small_Value (T));
8387 -- Process the constraint
8389 C := Constraint (S);
8391 -- Delta constraint present
8393 if Nkind (C) = N_Delta_Constraint then
8394 Check_Restriction (No_Obsolescent_Features, C);
8396 if Warn_On_Obsolescent_Feature then
8398 ("subtype delta constraint is an " &
8399 "obsolescent feature ('R'M 'J.3(7))?");
8402 D := Delta_Expression (C);
8403 Analyze_And_Resolve (D, Any_Real);
8404 Check_Delta_Expression (D);
8405 Set_Delta_Value (Def_Id, Expr_Value_R (D));
8407 -- Check that delta value is in range. Obviously we can do this
8408 -- at compile time, but it is strictly a runtime check, and of
8409 -- course there is an ACVC test that checks this!
8411 if Delta_Value (Def_Id) < Delta_Value (T) then
8412 Error_Msg_N ("?delta value is too small", D);
8414 Make_Raise_Constraint_Error (Sloc (D),
8415 Reason => CE_Range_Check_Failed);
8416 Insert_Action (Declaration_Node (Def_Id), Rais);
8419 C := Range_Constraint (C);
8421 -- No delta constraint present
8424 Set_Delta_Value (Def_Id, Delta_Value (T));
8427 -- Range constraint present
8429 if Nkind (C) = N_Range_Constraint then
8430 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8432 -- No range constraint present
8435 pragma Assert (No (C));
8436 Set_Scalar_Range (Def_Id, Scalar_Range (T));
8440 Set_Discrete_RM_Size (Def_Id);
8442 -- Unconditionally delay the freeze, since we cannot set size
8443 -- information in all cases correctly until the freeze point.
8445 Set_Has_Delayed_Freeze (Def_Id);
8446 end Constrain_Ordinary_Fixed;
8448 ---------------------------
8449 -- Convert_Scalar_Bounds --
8450 ---------------------------
8452 procedure Convert_Scalar_Bounds
8454 Parent_Type : Entity_Id;
8455 Derived_Type : Entity_Id;
8458 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
8465 Lo := Build_Scalar_Bound
8466 (Type_Low_Bound (Derived_Type),
8467 Parent_Type, Implicit_Base);
8469 Hi := Build_Scalar_Bound
8470 (Type_High_Bound (Derived_Type),
8471 Parent_Type, Implicit_Base);
8478 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
8480 Set_Parent (Rng, N);
8481 Set_Scalar_Range (Derived_Type, Rng);
8483 -- Analyze the bounds
8485 Analyze_And_Resolve (Lo, Implicit_Base);
8486 Analyze_And_Resolve (Hi, Implicit_Base);
8488 -- Analyze the range itself, except that we do not analyze it if
8489 -- the bounds are real literals, and we have a fixed-point type.
8490 -- The reason for this is that we delay setting the bounds in this
8491 -- case till we know the final Small and Size values (see circuit
8492 -- in Freeze.Freeze_Fixed_Point_Type for further details).
8494 if Is_Fixed_Point_Type (Parent_Type)
8495 and then Nkind (Lo) = N_Real_Literal
8496 and then Nkind (Hi) = N_Real_Literal
8500 -- Here we do the analysis of the range
8502 -- Note: we do this manually, since if we do a normal Analyze and
8503 -- Resolve call, there are problems with the conversions used for
8504 -- the derived type range.
8507 Set_Etype (Rng, Implicit_Base);
8508 Set_Analyzed (Rng, True);
8510 end Convert_Scalar_Bounds;
8516 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
8518 -- Initialize new full declaration entity by copying the pertinent
8519 -- fields of the corresponding private declaration entity.
8521 -- We temporarily set Ekind to a value appropriate for a type to
8522 -- avoid assert failures in Einfo from checking for setting type
8523 -- attributes on something that is not a type. Ekind (Priv) is an
8524 -- appropriate choice, since it allowed the attributes to be set
8525 -- in the first place. This Ekind value will be modified later.
8527 Set_Ekind (Full, Ekind (Priv));
8529 -- Also set Etype temporarily to Any_Type, again, in the absence
8530 -- of errors, it will be properly reset, and if there are errors,
8531 -- then we want a value of Any_Type to remain.
8533 Set_Etype (Full, Any_Type);
8535 -- Now start copying attributes
8537 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
8539 if Has_Discriminants (Full) then
8540 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
8541 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
8544 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
8545 Set_Homonym (Full, Homonym (Priv));
8546 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
8547 Set_Is_Public (Full, Is_Public (Priv));
8548 Set_Is_Pure (Full, Is_Pure (Priv));
8549 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
8551 Conditional_Delay (Full, Priv);
8553 if Is_Tagged_Type (Full) then
8554 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
8556 if Priv = Base_Type (Priv) then
8557 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
8561 Set_Is_Volatile (Full, Is_Volatile (Priv));
8562 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
8563 Set_Scope (Full, Scope (Priv));
8564 Set_Next_Entity (Full, Next_Entity (Priv));
8565 Set_First_Entity (Full, First_Entity (Priv));
8566 Set_Last_Entity (Full, Last_Entity (Priv));
8568 -- If access types have been recorded for later handling, keep them in
8569 -- the full view so that they get handled when the full view freeze
8570 -- node is expanded.
8572 if Present (Freeze_Node (Priv))
8573 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
8575 Ensure_Freeze_Node (Full);
8576 Set_Access_Types_To_Process
8577 (Freeze_Node (Full),
8578 Access_Types_To_Process (Freeze_Node (Priv)));
8581 -- Swap the two entities. Now Privat is the full type entity and
8582 -- Full is the private one. They will be swapped back at the end
8583 -- of the private part. This swapping ensures that the entity that
8584 -- is visible in the private part is the full declaration.
8586 Exchange_Entities (Priv, Full);
8587 Append_Entity (Full, Scope (Full));
8590 -------------------------------------
8591 -- Copy_Array_Base_Type_Attributes --
8592 -------------------------------------
8594 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
8596 Set_Component_Alignment (T1, Component_Alignment (T2));
8597 Set_Component_Type (T1, Component_Type (T2));
8598 Set_Component_Size (T1, Component_Size (T2));
8599 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
8600 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
8601 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
8602 Set_Has_Task (T1, Has_Task (T2));
8603 Set_Is_Packed (T1, Is_Packed (T2));
8604 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
8605 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
8606 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
8607 end Copy_Array_Base_Type_Attributes;
8609 -----------------------------------
8610 -- Copy_Array_Subtype_Attributes --
8611 -----------------------------------
8613 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
8615 Set_Size_Info (T1, T2);
8617 Set_First_Index (T1, First_Index (T2));
8618 Set_Is_Aliased (T1, Is_Aliased (T2));
8619 Set_Is_Atomic (T1, Is_Atomic (T2));
8620 Set_Is_Volatile (T1, Is_Volatile (T2));
8621 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
8622 Set_Is_Constrained (T1, Is_Constrained (T2));
8623 Set_Depends_On_Private (T1, Has_Private_Component (T2));
8624 Set_First_Rep_Item (T1, First_Rep_Item (T2));
8625 Set_Convention (T1, Convention (T2));
8626 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
8627 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
8628 end Copy_Array_Subtype_Attributes;
8630 -----------------------------------
8631 -- Create_Constrained_Components --
8632 -----------------------------------
8634 procedure Create_Constrained_Components
8636 Decl_Node : Node_Id;
8638 Constraints : Elist_Id)
8640 Loc : constant Source_Ptr := Sloc (Subt);
8641 Comp_List : constant Elist_Id := New_Elmt_List;
8642 Parent_Type : constant Entity_Id := Etype (Typ);
8643 Assoc_List : constant List_Id := New_List;
8644 Discr_Val : Elmt_Id;
8648 Is_Static : Boolean := True;
8650 procedure Collect_Fixed_Components (Typ : Entity_Id);
8651 -- Collect parent type components that do not appear in a variant part
8653 procedure Create_All_Components;
8654 -- Iterate over Comp_List to create the components of the subtype
8656 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
8657 -- Creates a new component from Old_Compon, copying all the fields from
8658 -- it, including its Etype, inserts the new component in the Subt entity
8659 -- chain and returns the new component.
8661 function Is_Variant_Record (T : Entity_Id) return Boolean;
8662 -- If true, and discriminants are static, collect only components from
8663 -- variants selected by discriminant values.
8665 ------------------------------
8666 -- Collect_Fixed_Components --
8667 ------------------------------
8669 procedure Collect_Fixed_Components (Typ : Entity_Id) is
8671 -- Build association list for discriminants, and find components of the
8672 -- variant part selected by the values of the discriminants.
8674 Old_C := First_Discriminant (Typ);
8675 Discr_Val := First_Elmt (Constraints);
8676 while Present (Old_C) loop
8677 Append_To (Assoc_List,
8678 Make_Component_Association (Loc,
8679 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
8680 Expression => New_Copy (Node (Discr_Val))));
8682 Next_Elmt (Discr_Val);
8683 Next_Discriminant (Old_C);
8686 -- The tag, and the possible parent and controller components
8687 -- are unconditionally in the subtype.
8689 if Is_Tagged_Type (Typ)
8690 or else Has_Controlled_Component (Typ)
8692 Old_C := First_Component (Typ);
8693 while Present (Old_C) loop
8694 if Chars ((Old_C)) = Name_uTag
8695 or else Chars ((Old_C)) = Name_uParent
8696 or else Chars ((Old_C)) = Name_uController
8698 Append_Elmt (Old_C, Comp_List);
8701 Next_Component (Old_C);
8704 end Collect_Fixed_Components;
8706 ---------------------------
8707 -- Create_All_Components --
8708 ---------------------------
8710 procedure Create_All_Components is
8714 Comp := First_Elmt (Comp_List);
8715 while Present (Comp) loop
8716 Old_C := Node (Comp);
8717 New_C := Create_Component (Old_C);
8721 Constrain_Component_Type
8722 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
8723 Set_Is_Public (New_C, Is_Public (Subt));
8727 end Create_All_Components;
8729 ----------------------
8730 -- Create_Component --
8731 ----------------------
8733 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
8734 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
8737 -- Set the parent so we have a proper link for freezing etc. This
8738 -- is not a real parent pointer, since of course our parent does
8739 -- not own up to us and reference us, we are an illegitimate
8740 -- child of the original parent!
8742 Set_Parent (New_Compon, Parent (Old_Compon));
8744 -- We do not want this node marked as Comes_From_Source, since
8745 -- otherwise it would get first class status and a separate
8746 -- cross-reference line would be generated. Illegitimate
8747 -- children do not rate such recognition.
8749 Set_Comes_From_Source (New_Compon, False);
8751 -- But it is a real entity, and a birth certificate must be
8752 -- properly registered by entering it into the entity list.
8754 Enter_Name (New_Compon);
8756 end Create_Component;
8758 -----------------------
8759 -- Is_Variant_Record --
8760 -----------------------
8762 function Is_Variant_Record (T : Entity_Id) return Boolean is
8764 return Nkind (Parent (T)) = N_Full_Type_Declaration
8765 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
8766 and then Present (Component_List (Type_Definition (Parent (T))))
8768 Variant_Part (Component_List (Type_Definition (Parent (T)))));
8769 end Is_Variant_Record;
8771 -- Start of processing for Create_Constrained_Components
8774 pragma Assert (Subt /= Base_Type (Subt));
8775 pragma Assert (Typ = Base_Type (Typ));
8777 Set_First_Entity (Subt, Empty);
8778 Set_Last_Entity (Subt, Empty);
8780 -- Check whether constraint is fully static, in which case we can
8781 -- optimize the list of components.
8783 Discr_Val := First_Elmt (Constraints);
8784 while Present (Discr_Val) loop
8785 if not Is_OK_Static_Expression (Node (Discr_Val)) then
8790 Next_Elmt (Discr_Val);
8795 -- Inherit the discriminants of the parent type
8797 Old_C := First_Discriminant (Typ);
8798 while Present (Old_C) loop
8799 New_C := Create_Component (Old_C);
8800 Set_Is_Public (New_C, Is_Public (Subt));
8801 Next_Discriminant (Old_C);
8805 and then Is_Variant_Record (Typ)
8807 Collect_Fixed_Components (Typ);
8811 Component_List (Type_Definition (Parent (Typ))),
8812 Governed_By => Assoc_List,
8814 Report_Errors => Errors);
8815 pragma Assert (not Errors);
8817 Create_All_Components;
8819 -- If the subtype declaration is created for a tagged type derivation
8820 -- with constraints, we retrieve the record definition of the parent
8821 -- type to select the components of the proper variant.
8824 and then Is_Tagged_Type (Typ)
8825 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
8827 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
8828 and then Is_Variant_Record (Parent_Type)
8830 Collect_Fixed_Components (Typ);
8834 Component_List (Type_Definition (Parent (Parent_Type))),
8835 Governed_By => Assoc_List,
8837 Report_Errors => Errors);
8838 pragma Assert (not Errors);
8840 -- If the tagged derivation has a type extension, collect all the
8841 -- new components therein.
8844 (Record_Extension_Part (Type_Definition (Parent (Typ))))
8846 Old_C := First_Component (Typ);
8847 while Present (Old_C) loop
8848 if Original_Record_Component (Old_C) = Old_C
8849 and then Chars (Old_C) /= Name_uTag
8850 and then Chars (Old_C) /= Name_uParent
8851 and then Chars (Old_C) /= Name_uController
8853 Append_Elmt (Old_C, Comp_List);
8856 Next_Component (Old_C);
8860 Create_All_Components;
8863 -- If the discriminants are not static, or if this is a multi-level
8864 -- type extension, we have to include all the components of the
8867 Old_C := First_Component (Typ);
8868 while Present (Old_C) loop
8869 New_C := Create_Component (Old_C);
8873 Constrain_Component_Type
8874 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
8875 Set_Is_Public (New_C, Is_Public (Subt));
8877 Next_Component (Old_C);
8882 end Create_Constrained_Components;
8884 ------------------------------------------
8885 -- Decimal_Fixed_Point_Type_Declaration --
8886 ------------------------------------------
8888 procedure Decimal_Fixed_Point_Type_Declaration
8892 Loc : constant Source_Ptr := Sloc (Def);
8893 Digs_Expr : constant Node_Id := Digits_Expression (Def);
8894 Delta_Expr : constant Node_Id := Delta_Expression (Def);
8895 Implicit_Base : Entity_Id;
8901 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
8904 Check_Restriction (No_Fixed_Point, Def);
8906 -- Create implicit base type
8909 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
8910 Set_Etype (Implicit_Base, Implicit_Base);
8912 -- Analyze and process delta expression
8914 Analyze_And_Resolve (Delta_Expr, Universal_Real);
8916 Check_Delta_Expression (Delta_Expr);
8917 Delta_Val := Expr_Value_R (Delta_Expr);
8919 -- Check delta is power of 10, and determine scale value from it
8922 Val : Ureal := Delta_Val;
8925 Scale_Val := Uint_0;
8927 if Val < Ureal_1 then
8928 while Val < Ureal_1 loop
8929 Val := Val * Ureal_10;
8930 Scale_Val := Scale_Val + 1;
8933 if Scale_Val > 18 then
8934 Error_Msg_N ("scale exceeds maximum value of 18", Def);
8935 Scale_Val := UI_From_Int (+18);
8939 while Val > Ureal_1 loop
8940 Val := Val / Ureal_10;
8941 Scale_Val := Scale_Val - 1;
8944 if Scale_Val < -18 then
8945 Error_Msg_N ("scale is less than minimum value of -18", Def);
8946 Scale_Val := UI_From_Int (-18);
8950 if Val /= Ureal_1 then
8951 Error_Msg_N ("delta expression must be a power of 10", Def);
8952 Delta_Val := Ureal_10 ** (-Scale_Val);
8956 -- Set delta, scale and small (small = delta for decimal type)
8958 Set_Delta_Value (Implicit_Base, Delta_Val);
8959 Set_Scale_Value (Implicit_Base, Scale_Val);
8960 Set_Small_Value (Implicit_Base, Delta_Val);
8962 -- Analyze and process digits expression
8964 Analyze_And_Resolve (Digs_Expr, Any_Integer);
8965 Check_Digits_Expression (Digs_Expr);
8966 Digs_Val := Expr_Value (Digs_Expr);
8968 if Digs_Val > 18 then
8969 Digs_Val := UI_From_Int (+18);
8970 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8973 Set_Digits_Value (Implicit_Base, Digs_Val);
8974 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8976 -- Set range of base type from digits value for now. This will be
8977 -- expanded to represent the true underlying base range by Freeze.
8979 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8981 -- Set size to zero for now, size will be set at freeze time. We have
8982 -- to do this for ordinary fixed-point, because the size depends on
8983 -- the specified small, and we might as well do the same for decimal
8986 Init_Size_Align (Implicit_Base);
8988 -- If there are bounds given in the declaration use them as the
8989 -- bounds of the first named subtype.
8991 if Present (Real_Range_Specification (Def)) then
8993 RRS : constant Node_Id := Real_Range_Specification (Def);
8994 Low : constant Node_Id := Low_Bound (RRS);
8995 High : constant Node_Id := High_Bound (RRS);
9000 Analyze_And_Resolve (Low, Any_Real);
9001 Analyze_And_Resolve (High, Any_Real);
9002 Check_Real_Bound (Low);
9003 Check_Real_Bound (High);
9004 Low_Val := Expr_Value_R (Low);
9005 High_Val := Expr_Value_R (High);
9007 if Low_Val < (-Bound_Val) then
9009 ("range low bound too small for digits value", Low);
9010 Low_Val := -Bound_Val;
9013 if High_Val > Bound_Val then
9015 ("range high bound too large for digits value", High);
9016 High_Val := Bound_Val;
9019 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
9022 -- If no explicit range, use range that corresponds to given
9023 -- digits value. This will end up as the final range for the
9027 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
9030 -- Complete entity for first subtype
9032 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
9033 Set_Etype (T, Implicit_Base);
9034 Set_Size_Info (T, Implicit_Base);
9035 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
9036 Set_Digits_Value (T, Digs_Val);
9037 Set_Delta_Value (T, Delta_Val);
9038 Set_Small_Value (T, Delta_Val);
9039 Set_Scale_Value (T, Scale_Val);
9040 Set_Is_Constrained (T);
9041 end Decimal_Fixed_Point_Type_Declaration;
9043 -----------------------
9044 -- Derive_Subprogram --
9045 -----------------------
9047 procedure Derive_Subprogram
9048 (New_Subp : in out Entity_Id;
9049 Parent_Subp : Entity_Id;
9050 Derived_Type : Entity_Id;
9051 Parent_Type : Entity_Id;
9052 Actual_Subp : Entity_Id := Empty)
9055 New_Formal : Entity_Id;
9056 Visible_Subp : Entity_Id := Parent_Subp;
9058 function Is_Private_Overriding return Boolean;
9059 -- If Subp is a private overriding of a visible operation, the in-
9060 -- herited operation derives from the overridden op (even though
9061 -- its body is the overriding one) and the inherited operation is
9062 -- visible now. See sem_disp to see the details of the handling of
9063 -- the overridden subprogram, which is removed from the list of
9064 -- primitive operations of the type. The overridden subprogram is
9065 -- saved locally in Visible_Subp, and used to diagnose abstract
9066 -- operations that need overriding in the derived type.
9068 procedure Replace_Type (Id, New_Id : Entity_Id);
9069 -- When the type is an anonymous access type, create a new access type
9070 -- designating the derived type.
9072 procedure Set_Derived_Name;
9073 -- This procedure sets the appropriate Chars name for New_Subp. This
9074 -- is normally just a copy of the parent name. An exception arises for
9075 -- type support subprograms, where the name is changed to reflect the
9076 -- name of the derived type, e.g. if type foo is derived from type bar,
9077 -- then a procedure barDA is derived with a name fooDA.
9079 ---------------------------
9080 -- Is_Private_Overriding --
9081 ---------------------------
9083 function Is_Private_Overriding return Boolean is
9087 -- The visible operation that is overriden is a homonym of the
9088 -- parent subprogram. We scan the homonym chain to find the one
9089 -- whose alias is the subprogram we are deriving.
9091 Prev := Homonym (Parent_Subp);
9092 while Present (Prev) loop
9093 if Is_Dispatching_Operation (Parent_Subp)
9094 and then Present (Prev)
9095 and then Ekind (Prev) = Ekind (Parent_Subp)
9096 and then Alias (Prev) = Parent_Subp
9097 and then Scope (Parent_Subp) = Scope (Prev)
9098 and then not Is_Hidden (Prev)
9100 Visible_Subp := Prev;
9104 Prev := Homonym (Prev);
9108 end Is_Private_Overriding;
9114 procedure Replace_Type (Id, New_Id : Entity_Id) is
9115 Acc_Type : Entity_Id;
9117 Par : constant Node_Id := Parent (Derived_Type);
9120 -- When the type is an anonymous access type, create a new access
9121 -- type designating the derived type. This itype must be elaborated
9122 -- at the point of the derivation, not on subsequent calls that may
9123 -- be out of the proper scope for Gigi, so we insert a reference to
9124 -- it after the derivation.
9126 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
9128 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
9131 if Ekind (Desig_Typ) = E_Record_Type_With_Private
9132 and then Present (Full_View (Desig_Typ))
9133 and then not Is_Private_Type (Parent_Type)
9135 Desig_Typ := Full_View (Desig_Typ);
9138 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
9139 Acc_Type := New_Copy (Etype (Id));
9140 Set_Etype (Acc_Type, Acc_Type);
9141 Set_Scope (Acc_Type, New_Subp);
9143 -- Compute size of anonymous access type
9145 if Is_Array_Type (Desig_Typ)
9146 and then not Is_Constrained (Desig_Typ)
9148 Init_Size (Acc_Type, 2 * System_Address_Size);
9150 Init_Size (Acc_Type, System_Address_Size);
9153 Init_Alignment (Acc_Type);
9154 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
9156 Set_Etype (New_Id, Acc_Type);
9157 Set_Scope (New_Id, New_Subp);
9159 -- Create a reference to it
9161 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
9162 Set_Itype (IR, Acc_Type);
9163 Insert_After (Parent (Derived_Type), IR);
9166 Set_Etype (New_Id, Etype (Id));
9170 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
9172 (Ekind (Etype (Id)) = E_Record_Type_With_Private
9173 and then Present (Full_View (Etype (Id)))
9175 Base_Type (Full_View (Etype (Id))) = Base_Type (Parent_Type))
9177 -- Constraint checks on formals are generated during expansion,
9178 -- based on the signature of the original subprogram. The bounds
9179 -- of the derived type are not relevant, and thus we can use
9180 -- the base type for the formals. However, the return type may be
9181 -- used in a context that requires that the proper static bounds
9182 -- be used (a case statement, for example) and for those cases
9183 -- we must use the derived type (first subtype), not its base.
9185 -- If the derived_type_definition has no constraints, we know that
9186 -- the derived type has the same constraints as the first subtype
9187 -- of the parent, and we can also use it rather than its base,
9188 -- which can lead to more efficient code.
9190 if Etype (Id) = Parent_Type then
9191 if Is_Scalar_Type (Parent_Type)
9193 Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
9195 Set_Etype (New_Id, Derived_Type);
9197 elsif Nkind (Par) = N_Full_Type_Declaration
9199 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
9202 (Subtype_Indication (Type_Definition (Par)))
9204 Set_Etype (New_Id, Derived_Type);
9207 Set_Etype (New_Id, Base_Type (Derived_Type));
9211 Set_Etype (New_Id, Base_Type (Derived_Type));
9215 Set_Etype (New_Id, Etype (Id));
9219 ----------------------
9220 -- Set_Derived_Name --
9221 ----------------------
9223 procedure Set_Derived_Name is
9224 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
9226 if Nm = TSS_Null then
9227 Set_Chars (New_Subp, Chars (Parent_Subp));
9229 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
9231 end Set_Derived_Name;
9233 -- Start of processing for Derive_Subprogram
9237 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
9238 Set_Ekind (New_Subp, Ekind (Parent_Subp));
9240 -- Check whether the inherited subprogram is a private operation that
9241 -- should be inherited but not yet made visible. Such subprograms can
9242 -- become visible at a later point (e.g., the private part of a public
9243 -- child unit) via Declare_Inherited_Private_Subprograms. If the
9244 -- following predicate is true, then this is not such a private
9245 -- operation and the subprogram simply inherits the name of the parent
9246 -- subprogram. Note the special check for the names of controlled
9247 -- operations, which are currently exempted from being inherited with
9248 -- a hidden name because they must be findable for generation of
9249 -- implicit run-time calls.
9251 if not Is_Hidden (Parent_Subp)
9252 or else Is_Internal (Parent_Subp)
9253 or else Is_Private_Overriding
9254 or else Is_Internal_Name (Chars (Parent_Subp))
9255 or else Chars (Parent_Subp) = Name_Initialize
9256 or else Chars (Parent_Subp) = Name_Adjust
9257 or else Chars (Parent_Subp) = Name_Finalize
9261 -- If parent is hidden, this can be a regular derivation if the
9262 -- parent is immediately visible in a non-instantiating context,
9263 -- or if we are in the private part of an instance. This test
9264 -- should still be refined ???
9266 -- The test for In_Instance_Not_Visible avoids inheriting the derived
9267 -- operation as a non-visible operation in cases where the parent
9268 -- subprogram might not be visible now, but was visible within the
9269 -- original generic, so it would be wrong to make the inherited
9270 -- subprogram non-visible now. (Not clear if this test is fully
9271 -- correct; are there any cases where we should declare the inherited
9272 -- operation as not visible to avoid it being overridden, e.g., when
9273 -- the parent type is a generic actual with private primitives ???)
9275 -- (they should be treated the same as other private inherited
9276 -- subprograms, but it's not clear how to do this cleanly). ???
9278 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
9279 and then Is_Immediately_Visible (Parent_Subp)
9280 and then not In_Instance)
9281 or else In_Instance_Not_Visible
9285 -- The type is inheriting a private operation, so enter
9286 -- it with a special name so it can't be overridden.
9289 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
9292 Set_Parent (New_Subp, Parent (Derived_Type));
9293 Replace_Type (Parent_Subp, New_Subp);
9294 Conditional_Delay (New_Subp, Parent_Subp);
9296 Formal := First_Formal (Parent_Subp);
9297 while Present (Formal) loop
9298 New_Formal := New_Copy (Formal);
9300 -- Normally we do not go copying parents, but in the case of
9301 -- formals, we need to link up to the declaration (which is the
9302 -- parameter specification), and it is fine to link up to the
9303 -- original formal's parameter specification in this case.
9305 Set_Parent (New_Formal, Parent (Formal));
9307 Append_Entity (New_Formal, New_Subp);
9309 Replace_Type (Formal, New_Formal);
9310 Next_Formal (Formal);
9313 -- If this derivation corresponds to a tagged generic actual, then
9314 -- primitive operations rename those of the actual. Otherwise the
9315 -- primitive operations rename those of the parent type, If the
9316 -- parent renames an intrinsic operator, so does the new subprogram.
9317 -- We except concatenation, which is always properly typed, and does
9318 -- not get expanded as other intrinsic operations.
9320 if No (Actual_Subp) then
9321 if Is_Intrinsic_Subprogram (Parent_Subp) then
9322 Set_Is_Intrinsic_Subprogram (New_Subp);
9324 if Present (Alias (Parent_Subp))
9325 and then Chars (Parent_Subp) /= Name_Op_Concat
9327 Set_Alias (New_Subp, Alias (Parent_Subp));
9329 Set_Alias (New_Subp, Parent_Subp);
9333 Set_Alias (New_Subp, Parent_Subp);
9337 Set_Alias (New_Subp, Actual_Subp);
9340 -- Derived subprograms of a tagged type must inherit the convention
9341 -- of the parent subprogram (a requirement of AI-117). Derived
9342 -- subprograms of untagged types simply get convention Ada by default.
9344 if Is_Tagged_Type (Derived_Type) then
9345 Set_Convention (New_Subp, Convention (Parent_Subp));
9348 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
9349 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
9351 if Ekind (Parent_Subp) = E_Procedure then
9352 Set_Is_Valued_Procedure
9353 (New_Subp, Is_Valued_Procedure (Parent_Subp));
9356 -- A derived function with a controlling result is abstract. If the
9357 -- Derived_Type is a nonabstract formal generic derived type, then
9358 -- inherited operations are not abstract: the required check is done at
9359 -- instantiation time. If the derivation is for a generic actual, the
9360 -- function is not abstract unless the actual is.
9362 if Is_Generic_Type (Derived_Type)
9363 and then not Is_Abstract (Derived_Type)
9367 elsif Is_Abstract (Alias (New_Subp))
9368 or else (Is_Tagged_Type (Derived_Type)
9369 and then Etype (New_Subp) = Derived_Type
9370 and then No (Actual_Subp))
9372 Set_Is_Abstract (New_Subp);
9374 -- Finally, if the parent type is abstract we must verify that all
9375 -- inherited operations are either non-abstract or overridden, or
9376 -- that the derived type itself is abstract (this check is performed
9377 -- at the end of a package declaration, in Check_Abstract_Overriding).
9378 -- A private overriding in the parent type will not be visible in the
9379 -- derivation if we are not in an inner package or in a child unit of
9380 -- the parent type, in which case the abstractness of the inherited
9381 -- operation is carried to the new subprogram.
9383 elsif Is_Abstract (Parent_Type)
9384 and then not In_Open_Scopes (Scope (Parent_Type))
9385 and then Is_Private_Overriding
9386 and then Is_Abstract (Visible_Subp)
9388 Set_Alias (New_Subp, Visible_Subp);
9389 Set_Is_Abstract (New_Subp);
9392 New_Overloaded_Entity (New_Subp, Derived_Type);
9394 -- Check for case of a derived subprogram for the instantiation of a
9395 -- formal derived tagged type, if so mark the subprogram as dispatching
9396 -- and inherit the dispatching attributes of the parent subprogram. The
9397 -- derived subprogram is effectively renaming of the actual subprogram,
9398 -- so it needs to have the same attributes as the actual.
9400 if Present (Actual_Subp)
9401 and then Is_Dispatching_Operation (Parent_Subp)
9403 Set_Is_Dispatching_Operation (New_Subp);
9404 if Present (DTC_Entity (Parent_Subp)) then
9405 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
9406 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
9410 -- Indicate that a derived subprogram does not require a body and that
9411 -- it does not require processing of default expressions.
9413 Set_Has_Completion (New_Subp);
9414 Set_Default_Expressions_Processed (New_Subp);
9416 if Ekind (New_Subp) = E_Function then
9417 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
9419 end Derive_Subprogram;
9421 ------------------------
9422 -- Derive_Subprograms --
9423 ------------------------
9425 procedure Derive_Subprograms
9426 (Parent_Type : Entity_Id;
9427 Derived_Type : Entity_Id;
9428 Generic_Actual : Entity_Id := Empty)
9430 Op_List : constant Elist_Id :=
9431 Collect_Primitive_Operations (Parent_Type);
9432 Act_List : Elist_Id;
9436 New_Subp : Entity_Id := Empty;
9437 Parent_Base : Entity_Id;
9440 if Ekind (Parent_Type) = E_Record_Type_With_Private
9441 and then Has_Discriminants (Parent_Type)
9442 and then Present (Full_View (Parent_Type))
9444 Parent_Base := Full_View (Parent_Type);
9446 Parent_Base := Parent_Type;
9449 if Present (Generic_Actual) then
9450 Act_List := Collect_Primitive_Operations (Generic_Actual);
9451 Act_Elmt := First_Elmt (Act_List);
9453 Act_Elmt := No_Elmt;
9456 -- Literals are derived earlier in the process of building the derived
9457 -- type, and are skipped here.
9459 Elmt := First_Elmt (Op_List);
9460 while Present (Elmt) loop
9461 Subp := Node (Elmt);
9463 if Ekind (Subp) /= E_Enumeration_Literal then
9464 if No (Generic_Actual) then
9466 (New_Subp, Subp, Derived_Type, Parent_Base);
9469 Derive_Subprogram (New_Subp, Subp,
9470 Derived_Type, Parent_Base, Node (Act_Elmt));
9471 Next_Elmt (Act_Elmt);
9477 end Derive_Subprograms;
9479 --------------------------------
9480 -- Derived_Standard_Character --
9481 --------------------------------
9483 procedure Derived_Standard_Character
9485 Parent_Type : Entity_Id;
9486 Derived_Type : Entity_Id)
9488 Loc : constant Source_Ptr := Sloc (N);
9489 Def : constant Node_Id := Type_Definition (N);
9490 Indic : constant Node_Id := Subtype_Indication (Def);
9491 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
9492 Implicit_Base : constant Entity_Id :=
9494 (E_Enumeration_Type, N, Derived_Type, 'B');
9500 Discard_Node (Process_Subtype (Indic, N));
9502 Set_Etype (Implicit_Base, Parent_Base);
9503 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
9504 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
9506 Set_Is_Character_Type (Implicit_Base, True);
9507 Set_Has_Delayed_Freeze (Implicit_Base);
9509 -- The bounds of the implicit base are the bounds of the parent base.
9510 -- Note that their type is the parent base.
9512 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
9513 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
9515 Set_Scalar_Range (Implicit_Base,
9520 Conditional_Delay (Derived_Type, Parent_Type);
9522 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
9523 Set_Etype (Derived_Type, Implicit_Base);
9524 Set_Size_Info (Derived_Type, Parent_Type);
9526 if Unknown_RM_Size (Derived_Type) then
9527 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
9530 Set_Is_Character_Type (Derived_Type, True);
9532 if Nkind (Indic) /= N_Subtype_Indication then
9534 -- If no explicit constraint, the bounds are those
9535 -- of the parent type.
9537 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
9538 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
9539 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
9542 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
9544 -- Because the implicit base is used in the conversion of the bounds,
9545 -- we have to freeze it now. This is similar to what is done for
9546 -- numeric types, and it equally suspicious, but otherwise a non-
9547 -- static bound will have a reference to an unfrozen type, which is
9548 -- rejected by Gigi (???).
9550 Freeze_Before (N, Implicit_Base);
9551 end Derived_Standard_Character;
9553 ------------------------------
9554 -- Derived_Type_Declaration --
9555 ------------------------------
9557 procedure Derived_Type_Declaration
9560 Is_Completion : Boolean)
9562 Def : constant Node_Id := Type_Definition (N);
9563 Indic : constant Node_Id := Subtype_Indication (Def);
9564 Extension : constant Node_Id := Record_Extension_Part (Def);
9565 Parent_Type : Entity_Id;
9566 Parent_Scope : Entity_Id;
9570 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
9572 if Parent_Type = Any_Type
9573 or else Etype (Parent_Type) = Any_Type
9574 or else (Is_Class_Wide_Type (Parent_Type)
9575 and then Etype (Parent_Type) = T)
9577 -- If Parent_Type is undefined or illegal, make new type into a
9578 -- subtype of Any_Type, and set a few attributes to prevent cascaded
9579 -- errors. If this is a self-definition, emit error now.
9582 or else T = Etype (Parent_Type)
9584 Error_Msg_N ("type cannot be used in its own definition", Indic);
9587 Set_Ekind (T, Ekind (Parent_Type));
9588 Set_Etype (T, Any_Type);
9589 Set_Scalar_Range (T, Scalar_Range (Any_Type));
9591 if Is_Tagged_Type (T) then
9592 Set_Primitive_Operations (T, New_Elmt_List);
9597 -- Ada 2005 (AI-231): Static check
9599 elsif Is_Access_Type (Parent_Type)
9600 and then Null_Exclusion_Present (Type_Definition (N))
9601 and then Can_Never_Be_Null (Parent_Type)
9603 Error_Msg_N ("(Ada 2005) null exclusion not allowed if parent is "
9604 & "already non-null", Type_Definition (N));
9607 -- Only composite types other than array types are allowed to have
9610 if Present (Discriminant_Specifications (N))
9611 and then (Is_Elementary_Type (Parent_Type)
9612 or else Is_Array_Type (Parent_Type))
9613 and then not Error_Posted (N)
9616 ("elementary or array type cannot have discriminants",
9617 Defining_Identifier (First (Discriminant_Specifications (N))));
9618 Set_Has_Discriminants (T, False);
9621 -- In Ada 83, a derived type defined in a package specification cannot
9622 -- be used for further derivation until the end of its visible part.
9623 -- Note that derivation in the private part of the package is allowed.
9625 if Ada_Version = Ada_83
9626 and then Is_Derived_Type (Parent_Type)
9627 and then In_Visible_Part (Scope (Parent_Type))
9629 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
9631 ("(Ada 83): premature use of type for derivation", Indic);
9635 -- Check for early use of incomplete or private type
9637 if Ekind (Parent_Type) = E_Void
9638 or else Ekind (Parent_Type) = E_Incomplete_Type
9640 Error_Msg_N ("premature derivation of incomplete type", Indic);
9643 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
9644 and then not Is_Generic_Type (Parent_Type)
9645 and then not Is_Generic_Type (Root_Type (Parent_Type))
9646 and then not Is_Generic_Actual_Type (Parent_Type))
9647 or else Has_Private_Component (Parent_Type)
9649 -- The ancestor type of a formal type can be incomplete, in which
9650 -- case only the operations of the partial view are available in
9651 -- the generic. Subsequent checks may be required when the full
9652 -- view is analyzed, to verify that derivation from a tagged type
9653 -- has an extension.
9655 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
9658 elsif No (Underlying_Type (Parent_Type))
9659 or else Has_Private_Component (Parent_Type)
9662 ("premature derivation of derived or private type", Indic);
9664 -- Flag the type itself as being in error, this prevents some
9665 -- nasty problems with people looking at the malformed type.
9667 Set_Error_Posted (T);
9669 -- Check that within the immediate scope of an untagged partial
9670 -- view it's illegal to derive from the partial view if the
9671 -- full view is tagged. (7.3(7))
9673 -- We verify that the Parent_Type is a partial view by checking
9674 -- that it is not a Full_Type_Declaration (i.e. a private type or
9675 -- private extension declaration), to distinguish a partial view
9676 -- from a derivation from a private type which also appears as
9679 elsif Present (Full_View (Parent_Type))
9680 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
9681 and then not Is_Tagged_Type (Parent_Type)
9682 and then Is_Tagged_Type (Full_View (Parent_Type))
9684 Parent_Scope := Scope (T);
9685 while Present (Parent_Scope)
9686 and then Parent_Scope /= Standard_Standard
9688 if Parent_Scope = Scope (Parent_Type) then
9690 ("premature derivation from type with tagged full view",
9694 Parent_Scope := Scope (Parent_Scope);
9699 -- Check that form of derivation is appropriate
9701 Taggd := Is_Tagged_Type (Parent_Type);
9703 -- Perhaps the parent type should be changed to the class-wide type's
9704 -- specific type in this case to prevent cascading errors ???
9706 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
9707 Error_Msg_N ("parent type must not be a class-wide type", Indic);
9711 if Present (Extension) and then not Taggd then
9713 ("type derived from untagged type cannot have extension", Indic);
9715 elsif No (Extension) and then Taggd then
9717 -- If this declaration is within a private part (or body) of a
9718 -- generic instantiation then the derivation is allowed (the parent
9719 -- type can only appear tagged in this case if it's a generic actual
9720 -- type, since it would otherwise have been rejected in the analysis
9721 -- of the generic template).
9723 if not Is_Generic_Actual_Type (Parent_Type)
9724 or else In_Visible_Part (Scope (Parent_Type))
9727 ("type derived from tagged type must have extension", Indic);
9731 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
9732 end Derived_Type_Declaration;
9734 ----------------------------------
9735 -- Enumeration_Type_Declaration --
9736 ----------------------------------
9738 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9745 -- Create identifier node representing lower bound
9747 B_Node := New_Node (N_Identifier, Sloc (Def));
9748 L := First (Literals (Def));
9749 Set_Chars (B_Node, Chars (L));
9750 Set_Entity (B_Node, L);
9751 Set_Etype (B_Node, T);
9752 Set_Is_Static_Expression (B_Node, True);
9754 R_Node := New_Node (N_Range, Sloc (Def));
9755 Set_Low_Bound (R_Node, B_Node);
9757 Set_Ekind (T, E_Enumeration_Type);
9758 Set_First_Literal (T, L);
9760 Set_Is_Constrained (T);
9764 -- Loop through literals of enumeration type setting pos and rep values
9765 -- except that if the Ekind is already set, then it means that the
9766 -- literal was already constructed (case of a derived type declaration
9767 -- and we should not disturb the Pos and Rep values.
9769 while Present (L) loop
9770 if Ekind (L) /= E_Enumeration_Literal then
9771 Set_Ekind (L, E_Enumeration_Literal);
9772 Set_Enumeration_Pos (L, Ev);
9773 Set_Enumeration_Rep (L, Ev);
9774 Set_Is_Known_Valid (L, True);
9778 New_Overloaded_Entity (L);
9779 Generate_Definition (L);
9780 Set_Convention (L, Convention_Intrinsic);
9782 if Nkind (L) = N_Defining_Character_Literal then
9783 Set_Is_Character_Type (T, True);
9790 -- Now create a node representing upper bound
9792 B_Node := New_Node (N_Identifier, Sloc (Def));
9793 Set_Chars (B_Node, Chars (Last (Literals (Def))));
9794 Set_Entity (B_Node, Last (Literals (Def)));
9795 Set_Etype (B_Node, T);
9796 Set_Is_Static_Expression (B_Node, True);
9798 Set_High_Bound (R_Node, B_Node);
9799 Set_Scalar_Range (T, R_Node);
9800 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
9803 -- Set Discard_Names if configuration pragma set, or if there is
9804 -- a parameterless pragma in the current declarative region
9806 if Global_Discard_Names
9807 or else Discard_Names (Scope (T))
9809 Set_Discard_Names (T);
9812 -- Process end label if there is one
9814 if Present (Def) then
9815 Process_End_Label (Def, 'e', T);
9817 end Enumeration_Type_Declaration;
9819 ---------------------------------
9820 -- Expand_To_Stored_Constraint --
9821 ---------------------------------
9823 function Expand_To_Stored_Constraint
9825 Constraint : Elist_Id) return Elist_Id
9827 Explicitly_Discriminated_Type : Entity_Id;
9828 Expansion : Elist_Id;
9829 Discriminant : Entity_Id;
9831 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
9832 -- Find the nearest type that actually specifies discriminants
9834 ---------------------------------
9835 -- Type_With_Explicit_Discrims --
9836 ---------------------------------
9838 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
9839 Typ : constant E := Base_Type (Id);
9842 if Ekind (Typ) in Incomplete_Or_Private_Kind then
9843 if Present (Full_View (Typ)) then
9844 return Type_With_Explicit_Discrims (Full_View (Typ));
9848 if Has_Discriminants (Typ) then
9853 if Etype (Typ) = Typ then
9855 elsif Has_Discriminants (Typ) then
9858 return Type_With_Explicit_Discrims (Etype (Typ));
9861 end Type_With_Explicit_Discrims;
9863 -- Start of processing for Expand_To_Stored_Constraint
9867 or else Is_Empty_Elmt_List (Constraint)
9872 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
9874 if No (Explicitly_Discriminated_Type) then
9878 Expansion := New_Elmt_List;
9881 First_Stored_Discriminant (Explicitly_Discriminated_Type);
9882 while Present (Discriminant) loop
9884 Get_Discriminant_Value (
9885 Discriminant, Explicitly_Discriminated_Type, Constraint),
9887 Next_Stored_Discriminant (Discriminant);
9891 end Expand_To_Stored_Constraint;
9893 --------------------
9894 -- Find_Type_Name --
9895 --------------------
9897 function Find_Type_Name (N : Node_Id) return Entity_Id is
9898 Id : constant Entity_Id := Defining_Identifier (N);
9904 -- Find incomplete declaration, if one was given
9906 Prev := Current_Entity_In_Scope (Id);
9908 if Present (Prev) then
9910 -- Previous declaration exists. Error if not incomplete/private case
9911 -- except if previous declaration is implicit, etc. Enter_Name will
9912 -- emit error if appropriate.
9914 Prev_Par := Parent (Prev);
9916 if not Is_Incomplete_Or_Private_Type (Prev) then
9920 elsif Nkind (N) /= N_Full_Type_Declaration
9921 and then Nkind (N) /= N_Task_Type_Declaration
9922 and then Nkind (N) /= N_Protected_Type_Declaration
9924 -- Completion must be a full type declarations (RM 7.3(4))
9926 Error_Msg_Sloc := Sloc (Prev);
9927 Error_Msg_NE ("invalid completion of }", Id, Prev);
9929 -- Set scope of Id to avoid cascaded errors. Entity is never
9930 -- examined again, except when saving globals in generics.
9932 Set_Scope (Id, Current_Scope);
9935 -- Case of full declaration of incomplete type
9937 elsif Ekind (Prev) = E_Incomplete_Type then
9939 -- Indicate that the incomplete declaration has a matching full
9940 -- declaration. The defining occurrence of the incomplete
9941 -- declaration remains the visible one, and the procedure
9942 -- Get_Full_View dereferences it whenever the type is used.
9944 if Present (Full_View (Prev)) then
9945 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9948 Set_Full_View (Prev, Id);
9949 Append_Entity (Id, Current_Scope);
9950 Set_Is_Public (Id, Is_Public (Prev));
9951 Set_Is_Internal (Id);
9954 -- Case of full declaration of private type
9957 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9958 if Etype (Prev) /= Prev then
9960 -- Prev is a private subtype or a derived type, and needs
9963 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9966 elsif Ekind (Prev) = E_Private_Type
9968 (Nkind (N) = N_Task_Type_Declaration
9969 or else Nkind (N) = N_Protected_Type_Declaration)
9972 ("completion of nonlimited type cannot be limited", N);
9975 elsif Nkind (N) /= N_Full_Type_Declaration
9976 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9979 ("full view of private extension must be an extension", N);
9981 elsif not (Abstract_Present (Parent (Prev)))
9982 and then Abstract_Present (Type_Definition (N))
9985 ("full view of non-abstract extension cannot be abstract", N);
9988 if not In_Private_Part (Current_Scope) then
9990 ("declaration of full view must appear in private part", N);
9993 Copy_And_Swap (Prev, Id);
9994 Set_Has_Private_Declaration (Prev);
9995 Set_Has_Private_Declaration (Id);
9997 -- If no error, propagate freeze_node from private to full view.
9998 -- It may have been generated for an early operational item.
10000 if Present (Freeze_Node (Id))
10001 and then Serious_Errors_Detected = 0
10002 and then No (Full_View (Id))
10004 Set_Freeze_Node (Prev, Freeze_Node (Id));
10005 Set_Freeze_Node (Id, Empty);
10006 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
10009 Set_Full_View (Id, Prev);
10013 -- Verify that full declaration conforms to incomplete one
10015 if Is_Incomplete_Or_Private_Type (Prev)
10016 and then Present (Discriminant_Specifications (Prev_Par))
10018 if Present (Discriminant_Specifications (N)) then
10019 if Ekind (Prev) = E_Incomplete_Type then
10020 Check_Discriminant_Conformance (N, Prev, Prev);
10022 Check_Discriminant_Conformance (N, Prev, Id);
10027 ("missing discriminants in full type declaration", N);
10029 -- To avoid cascaded errors on subsequent use, share the
10030 -- discriminants of the partial view.
10032 Set_Discriminant_Specifications (N,
10033 Discriminant_Specifications (Prev_Par));
10037 -- A prior untagged private type can have an associated class-wide
10038 -- type due to use of the class attribute, and in this case also the
10039 -- full type is required to be tagged.
10042 and then (Is_Tagged_Type (Prev)
10043 or else Present (Class_Wide_Type (Prev)))
10045 -- The full declaration is either a tagged record or an
10046 -- extension otherwise this is an error
10048 if Nkind (Type_Definition (N)) = N_Record_Definition then
10049 if not Tagged_Present (Type_Definition (N)) then
10051 ("full declaration of } must be tagged", Prev, Id);
10052 Set_Is_Tagged_Type (Id);
10053 Set_Primitive_Operations (Id, New_Elmt_List);
10056 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
10057 if No (Record_Extension_Part (Type_Definition (N))) then
10059 "full declaration of } must be a record extension",
10061 Set_Is_Tagged_Type (Id);
10062 Set_Primitive_Operations (Id, New_Elmt_List);
10067 ("full declaration of } must be a tagged type", Prev, Id);
10075 -- New type declaration
10080 end Find_Type_Name;
10082 -------------------------
10083 -- Find_Type_Of_Object --
10084 -------------------------
10086 function Find_Type_Of_Object
10087 (Obj_Def : Node_Id;
10088 Related_Nod : Node_Id) return Entity_Id
10090 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
10091 P : Node_Id := Parent (Obj_Def);
10096 -- If the parent is a component_definition node we climb to the
10097 -- component_declaration node
10099 if Nkind (P) = N_Component_Definition then
10103 -- Case of an anonymous array subtype
10105 if Def_Kind = N_Constrained_Array_Definition
10106 or else Def_Kind = N_Unconstrained_Array_Definition
10109 Array_Type_Declaration (T, Obj_Def);
10111 -- Create an explicit subtype whenever possible
10113 elsif Nkind (P) /= N_Component_Declaration
10114 and then Def_Kind = N_Subtype_Indication
10116 -- Base name of subtype on object name, which will be unique in
10117 -- the current scope.
10119 -- If this is a duplicate declaration, return base type, to avoid
10120 -- generating duplicate anonymous types.
10122 if Error_Posted (P) then
10123 Analyze (Subtype_Mark (Obj_Def));
10124 return Entity (Subtype_Mark (Obj_Def));
10129 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
10131 T := Make_Defining_Identifier (Sloc (P), Nam);
10133 Insert_Action (Obj_Def,
10134 Make_Subtype_Declaration (Sloc (P),
10135 Defining_Identifier => T,
10136 Subtype_Indication => Relocate_Node (Obj_Def)));
10138 -- This subtype may need freezing, and this will not be done
10139 -- automatically if the object declaration is not in declarative
10140 -- part. Since this is an object declaration, the type cannot always
10141 -- be frozen here. Deferred constants do not freeze their type
10142 -- (which often enough will be private).
10144 if Nkind (P) = N_Object_Declaration
10145 and then Constant_Present (P)
10146 and then No (Expression (P))
10151 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
10155 T := Process_Subtype (Obj_Def, Related_Nod);
10159 end Find_Type_Of_Object;
10161 --------------------------------
10162 -- Find_Type_Of_Subtype_Indic --
10163 --------------------------------
10165 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
10169 -- Case of subtype mark with a constraint
10171 if Nkind (S) = N_Subtype_Indication then
10172 Find_Type (Subtype_Mark (S));
10173 Typ := Entity (Subtype_Mark (S));
10176 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
10179 ("incorrect constraint for this kind of type", Constraint (S));
10180 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
10183 -- Otherwise we have a subtype mark without a constraint
10185 elsif Error_Posted (S) then
10186 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
10194 if Typ = Standard_Wide_Character
10195 or else Typ = Standard_Wide_String
10197 Check_Restriction (No_Wide_Characters, S);
10201 end Find_Type_Of_Subtype_Indic;
10203 -------------------------------------
10204 -- Floating_Point_Type_Declaration --
10205 -------------------------------------
10207 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10208 Digs : constant Node_Id := Digits_Expression (Def);
10210 Base_Typ : Entity_Id;
10211 Implicit_Base : Entity_Id;
10214 function Can_Derive_From (E : Entity_Id) return Boolean;
10215 -- Find if given digits value allows derivation from specified type
10217 ---------------------
10218 -- Can_Derive_From --
10219 ---------------------
10221 function Can_Derive_From (E : Entity_Id) return Boolean is
10222 Spec : constant Entity_Id := Real_Range_Specification (Def);
10225 if Digs_Val > Digits_Value (E) then
10229 if Present (Spec) then
10230 if Expr_Value_R (Type_Low_Bound (E)) >
10231 Expr_Value_R (Low_Bound (Spec))
10236 if Expr_Value_R (Type_High_Bound (E)) <
10237 Expr_Value_R (High_Bound (Spec))
10244 end Can_Derive_From;
10246 -- Start of processing for Floating_Point_Type_Declaration
10249 Check_Restriction (No_Floating_Point, Def);
10251 -- Create an implicit base type
10254 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
10256 -- Analyze and verify digits value
10258 Analyze_And_Resolve (Digs, Any_Integer);
10259 Check_Digits_Expression (Digs);
10260 Digs_Val := Expr_Value (Digs);
10262 -- Process possible range spec and find correct type to derive from
10264 Process_Real_Range_Specification (Def);
10266 if Can_Derive_From (Standard_Short_Float) then
10267 Base_Typ := Standard_Short_Float;
10268 elsif Can_Derive_From (Standard_Float) then
10269 Base_Typ := Standard_Float;
10270 elsif Can_Derive_From (Standard_Long_Float) then
10271 Base_Typ := Standard_Long_Float;
10272 elsif Can_Derive_From (Standard_Long_Long_Float) then
10273 Base_Typ := Standard_Long_Long_Float;
10275 -- If we can't derive from any existing type, use long_long_float
10276 -- and give appropriate message explaining the problem.
10279 Base_Typ := Standard_Long_Long_Float;
10281 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
10282 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
10283 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
10287 ("range too large for any predefined type",
10288 Real_Range_Specification (Def));
10292 -- If there are bounds given in the declaration use them as the bounds
10293 -- of the type, otherwise use the bounds of the predefined base type
10294 -- that was chosen based on the Digits value.
10296 if Present (Real_Range_Specification (Def)) then
10297 Set_Scalar_Range (T, Real_Range_Specification (Def));
10298 Set_Is_Constrained (T);
10300 -- The bounds of this range must be converted to machine numbers
10301 -- in accordance with RM 4.9(38).
10303 Bound := Type_Low_Bound (T);
10305 if Nkind (Bound) = N_Real_Literal then
10307 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
10308 Set_Is_Machine_Number (Bound);
10311 Bound := Type_High_Bound (T);
10313 if Nkind (Bound) = N_Real_Literal then
10315 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
10316 Set_Is_Machine_Number (Bound);
10320 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
10323 -- Complete definition of implicit base and declared first subtype
10325 Set_Etype (Implicit_Base, Base_Typ);
10327 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
10328 Set_Size_Info (Implicit_Base, (Base_Typ));
10329 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
10330 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
10331 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
10332 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
10334 Set_Ekind (T, E_Floating_Point_Subtype);
10335 Set_Etype (T, Implicit_Base);
10337 Set_Size_Info (T, (Implicit_Base));
10338 Set_RM_Size (T, RM_Size (Implicit_Base));
10339 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
10340 Set_Digits_Value (T, Digs_Val);
10341 end Floating_Point_Type_Declaration;
10343 ----------------------------
10344 -- Get_Discriminant_Value --
10345 ----------------------------
10347 -- This is the situation:
10349 -- There is a non-derived type
10351 -- type T0 (Dx, Dy, Dz...)
10353 -- There are zero or more levels of derivation, with each derivation
10354 -- either purely inheriting the discriminants, or defining its own.
10356 -- type Ti is new Ti-1
10358 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
10360 -- subtype Ti is ...
10362 -- The subtype issue is avoided by the use of Original_Record_Component,
10363 -- and the fact that derived subtypes also derive the constraints.
10365 -- This chain leads back from
10367 -- Typ_For_Constraint
10369 -- Typ_For_Constraint has discriminants, and the value for each
10370 -- discriminant is given by its corresponding Elmt of Constraints.
10372 -- Discriminant is some discriminant in this hierarchy
10374 -- We need to return its value
10376 -- We do this by recursively searching each level, and looking for
10377 -- Discriminant. Once we get to the bottom, we start backing up
10378 -- returning the value for it which may in turn be a discriminant
10379 -- further up, so on the backup we continue the substitution.
10381 function Get_Discriminant_Value
10382 (Discriminant : Entity_Id;
10383 Typ_For_Constraint : Entity_Id;
10384 Constraint : Elist_Id) return Node_Id
10386 function Search_Derivation_Levels
10388 Discrim_Values : Elist_Id;
10389 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
10390 -- This is the routine that performs the recursive search of levels
10391 -- as described above.
10393 ------------------------------
10394 -- Search_Derivation_Levels --
10395 ------------------------------
10397 function Search_Derivation_Levels
10399 Discrim_Values : Elist_Id;
10400 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
10404 Result : Node_Or_Entity_Id;
10405 Result_Entity : Node_Id;
10408 -- If inappropriate type, return Error, this happens only in
10409 -- cascaded error situations, and we want to avoid a blow up.
10411 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
10415 -- Look deeper if possible. Use Stored_Constraints only for
10416 -- untagged types. For tagged types use the given constraint.
10417 -- This asymmetry needs explanation???
10419 if not Stored_Discrim_Values
10420 and then Present (Stored_Constraint (Ti))
10421 and then not Is_Tagged_Type (Ti)
10424 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
10427 Td : constant Entity_Id := Etype (Ti);
10431 Result := Discriminant;
10434 if Present (Stored_Constraint (Ti)) then
10436 Search_Derivation_Levels
10437 (Td, Stored_Constraint (Ti), True);
10440 Search_Derivation_Levels
10441 (Td, Discrim_Values, Stored_Discrim_Values);
10447 -- Extra underlying places to search, if not found above. For
10448 -- concurrent types, the relevant discriminant appears in the
10449 -- corresponding record. For a type derived from a private type
10450 -- without discriminant, the full view inherits the discriminants
10451 -- of the full view of the parent.
10453 if Result = Discriminant then
10454 if Is_Concurrent_Type (Ti)
10455 and then Present (Corresponding_Record_Type (Ti))
10458 Search_Derivation_Levels (
10459 Corresponding_Record_Type (Ti),
10461 Stored_Discrim_Values);
10463 elsif Is_Private_Type (Ti)
10464 and then not Has_Discriminants (Ti)
10465 and then Present (Full_View (Ti))
10466 and then Etype (Full_View (Ti)) /= Ti
10469 Search_Derivation_Levels (
10472 Stored_Discrim_Values);
10476 -- If Result is not a (reference to a) discriminant, return it,
10477 -- otherwise set Result_Entity to the discriminant.
10479 if Nkind (Result) = N_Defining_Identifier then
10480 pragma Assert (Result = Discriminant);
10481 Result_Entity := Result;
10484 if not Denotes_Discriminant (Result) then
10488 Result_Entity := Entity (Result);
10491 -- See if this level of derivation actually has discriminants
10492 -- because tagged derivations can add them, hence the lower
10493 -- levels need not have any.
10495 if not Has_Discriminants (Ti) then
10499 -- Scan Ti's discriminants for Result_Entity,
10500 -- and return its corresponding value, if any.
10502 Result_Entity := Original_Record_Component (Result_Entity);
10504 Assoc := First_Elmt (Discrim_Values);
10506 if Stored_Discrim_Values then
10507 Disc := First_Stored_Discriminant (Ti);
10509 Disc := First_Discriminant (Ti);
10512 while Present (Disc) loop
10513 pragma Assert (Present (Assoc));
10515 if Original_Record_Component (Disc) = Result_Entity then
10516 return Node (Assoc);
10521 if Stored_Discrim_Values then
10522 Next_Stored_Discriminant (Disc);
10524 Next_Discriminant (Disc);
10528 -- Could not find it
10531 end Search_Derivation_Levels;
10533 Result : Node_Or_Entity_Id;
10535 -- Start of processing for Get_Discriminant_Value
10538 -- ??? This routine is a gigantic mess and will be deleted. For the
10539 -- time being just test for the trivial case before calling recurse.
10541 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
10543 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
10544 E : Elmt_Id := First_Elmt (Constraint);
10547 while Present (D) loop
10548 if Chars (D) = Chars (Discriminant) then
10552 Next_Discriminant (D);
10558 Result := Search_Derivation_Levels
10559 (Typ_For_Constraint, Constraint, False);
10561 -- ??? hack to disappear when this routine is gone
10563 if Nkind (Result) = N_Defining_Identifier then
10565 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
10566 E : Elmt_Id := First_Elmt (Constraint);
10569 while Present (D) loop
10570 if Corresponding_Discriminant (D) = Discriminant then
10574 Next_Discriminant (D);
10580 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
10582 end Get_Discriminant_Value;
10584 --------------------------
10585 -- Has_Range_Constraint --
10586 --------------------------
10588 function Has_Range_Constraint (N : Node_Id) return Boolean is
10589 C : constant Node_Id := Constraint (N);
10592 if Nkind (C) = N_Range_Constraint then
10595 elsif Nkind (C) = N_Digits_Constraint then
10597 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
10599 Present (Range_Constraint (C));
10601 elsif Nkind (C) = N_Delta_Constraint then
10602 return Present (Range_Constraint (C));
10607 end Has_Range_Constraint;
10609 ------------------------
10610 -- Inherit_Components --
10611 ------------------------
10613 function Inherit_Components
10615 Parent_Base : Entity_Id;
10616 Derived_Base : Entity_Id;
10617 Is_Tagged : Boolean;
10618 Inherit_Discr : Boolean;
10619 Discs : Elist_Id) return Elist_Id
10621 Assoc_List : constant Elist_Id := New_Elmt_List;
10623 procedure Inherit_Component
10624 (Old_C : Entity_Id;
10625 Plain_Discrim : Boolean := False;
10626 Stored_Discrim : Boolean := False);
10627 -- Inherits component Old_C from Parent_Base to the Derived_Base. If
10628 -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
10629 -- True, Old_C is a stored discriminant. If they are both false then
10630 -- Old_C is a regular component.
10632 -----------------------
10633 -- Inherit_Component --
10634 -----------------------
10636 procedure Inherit_Component
10637 (Old_C : Entity_Id;
10638 Plain_Discrim : Boolean := False;
10639 Stored_Discrim : Boolean := False)
10641 New_C : constant Entity_Id := New_Copy (Old_C);
10643 Discrim : Entity_Id;
10644 Corr_Discrim : Entity_Id;
10647 pragma Assert (not Is_Tagged or else not Stored_Discrim);
10649 Set_Parent (New_C, Parent (Old_C));
10651 -- Regular discriminants and components must be inserted
10652 -- in the scope of the Derived_Base. Do it here.
10654 if not Stored_Discrim then
10655 Enter_Name (New_C);
10658 -- For tagged types the Original_Record_Component must point to
10659 -- whatever this field was pointing to in the parent type. This has
10660 -- already been achieved by the call to New_Copy above.
10662 if not Is_Tagged then
10663 Set_Original_Record_Component (New_C, New_C);
10666 -- If we have inherited a component then see if its Etype contains
10667 -- references to Parent_Base discriminants. In this case, replace
10668 -- these references with the constraints given in Discs. We do not
10669 -- do this for the partial view of private types because this is
10670 -- not needed (only the components of the full view will be used
10671 -- for code generation) and cause problem. We also avoid this
10672 -- transformation in some error situations.
10674 if Ekind (New_C) = E_Component then
10675 if (Is_Private_Type (Derived_Base)
10676 and then not Is_Generic_Type (Derived_Base))
10677 or else (Is_Empty_Elmt_List (Discs)
10678 and then not Expander_Active)
10680 Set_Etype (New_C, Etype (Old_C));
10682 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
10683 Derived_Base, N, Parent_Base, Discs));
10687 -- In derived tagged types it is illegal to reference a non
10688 -- discriminant component in the parent type. To catch this, mark
10689 -- these components with an Ekind of E_Void. This will be reset in
10690 -- Record_Type_Definition after processing the record extension of
10691 -- the derived type.
10693 if Is_Tagged and then Ekind (New_C) = E_Component then
10694 Set_Ekind (New_C, E_Void);
10697 if Plain_Discrim then
10698 Set_Corresponding_Discriminant (New_C, Old_C);
10699 Build_Discriminal (New_C);
10701 -- If we are explicitly inheriting a stored discriminant it will be
10702 -- completely hidden.
10704 elsif Stored_Discrim then
10705 Set_Corresponding_Discriminant (New_C, Empty);
10706 Set_Discriminal (New_C, Empty);
10707 Set_Is_Completely_Hidden (New_C);
10709 -- Set the Original_Record_Component of each discriminant in the
10710 -- derived base to point to the corresponding stored that we just
10713 Discrim := First_Discriminant (Derived_Base);
10714 while Present (Discrim) loop
10715 Corr_Discrim := Corresponding_Discriminant (Discrim);
10717 -- Corr_Discrimm could be missing in an error situation
10719 if Present (Corr_Discrim)
10720 and then Original_Record_Component (Corr_Discrim) = Old_C
10722 Set_Original_Record_Component (Discrim, New_C);
10725 Next_Discriminant (Discrim);
10728 Append_Entity (New_C, Derived_Base);
10731 if not Is_Tagged then
10732 Append_Elmt (Old_C, Assoc_List);
10733 Append_Elmt (New_C, Assoc_List);
10735 end Inherit_Component;
10737 -- Variables local to Inherit_Component
10739 Loc : constant Source_Ptr := Sloc (N);
10741 Parent_Discrim : Entity_Id;
10742 Stored_Discrim : Entity_Id;
10744 Component : Entity_Id;
10746 -- Start of processing for Inherit_Components
10749 if not Is_Tagged then
10750 Append_Elmt (Parent_Base, Assoc_List);
10751 Append_Elmt (Derived_Base, Assoc_List);
10754 -- Inherit parent discriminants if needed
10756 if Inherit_Discr then
10757 Parent_Discrim := First_Discriminant (Parent_Base);
10758 while Present (Parent_Discrim) loop
10759 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
10760 Next_Discriminant (Parent_Discrim);
10764 -- Create explicit stored discrims for untagged types when necessary
10766 if not Has_Unknown_Discriminants (Derived_Base)
10767 and then Has_Discriminants (Parent_Base)
10768 and then not Is_Tagged
10771 or else First_Discriminant (Parent_Base) /=
10772 First_Stored_Discriminant (Parent_Base))
10774 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
10775 while Present (Stored_Discrim) loop
10776 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
10777 Next_Stored_Discriminant (Stored_Discrim);
10781 -- See if we can apply the second transformation for derived types, as
10782 -- explained in point 6. in the comments above Build_Derived_Record_Type
10783 -- This is achieved by appending Derived_Base discriminants into Discs,
10784 -- which has the side effect of returning a non empty Discs list to the
10785 -- caller of Inherit_Components, which is what we want. This must be
10786 -- done for private derived types if there are explicit stored
10787 -- discriminants, to ensure that we can retrieve the values of the
10788 -- constraints provided in the ancestors.
10791 and then Is_Empty_Elmt_List (Discs)
10792 and then Present (First_Discriminant (Derived_Base))
10794 (not Is_Private_Type (Derived_Base)
10795 or else Is_Completely_Hidden
10796 (First_Stored_Discriminant (Derived_Base))
10797 or else Is_Generic_Type (Derived_Base))
10799 D := First_Discriminant (Derived_Base);
10800 while Present (D) loop
10801 Append_Elmt (New_Reference_To (D, Loc), Discs);
10802 Next_Discriminant (D);
10806 -- Finally, inherit non-discriminant components unless they are not
10807 -- visible because defined or inherited from the full view of the
10808 -- parent. Don't inherit the _parent field of the parent type.
10810 Component := First_Entity (Parent_Base);
10811 while Present (Component) loop
10812 if Ekind (Component) /= E_Component
10813 or else Chars (Component) = Name_uParent
10817 -- If the derived type is within the parent type's declarative
10818 -- region, then the components can still be inherited even though
10819 -- they aren't visible at this point. This can occur for cases
10820 -- such as within public child units where the components must
10821 -- become visible upon entering the child unit's private part.
10823 elsif not Is_Visible_Component (Component)
10824 and then not In_Open_Scopes (Scope (Parent_Base))
10828 elsif Ekind (Derived_Base) = E_Private_Type
10829 or else Ekind (Derived_Base) = E_Limited_Private_Type
10834 Inherit_Component (Component);
10837 Next_Entity (Component);
10840 -- For tagged derived types, inherited discriminants cannot be used in
10841 -- component declarations of the record extension part. To achieve this
10842 -- we mark the inherited discriminants as not visible.
10844 if Is_Tagged and then Inherit_Discr then
10845 D := First_Discriminant (Derived_Base);
10846 while Present (D) loop
10847 Set_Is_Immediately_Visible (D, False);
10848 Next_Discriminant (D);
10853 end Inherit_Components;
10855 ------------------------------
10856 -- Is_Valid_Constraint_Kind --
10857 ------------------------------
10859 function Is_Valid_Constraint_Kind
10860 (T_Kind : Type_Kind;
10861 Constraint_Kind : Node_Kind) return Boolean
10865 when Enumeration_Kind |
10867 return Constraint_Kind = N_Range_Constraint;
10869 when Decimal_Fixed_Point_Kind =>
10871 Constraint_Kind = N_Digits_Constraint
10873 Constraint_Kind = N_Range_Constraint;
10875 when Ordinary_Fixed_Point_Kind =>
10877 Constraint_Kind = N_Delta_Constraint
10879 Constraint_Kind = N_Range_Constraint;
10883 Constraint_Kind = N_Digits_Constraint
10885 Constraint_Kind = N_Range_Constraint;
10892 E_Incomplete_Type |
10895 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
10898 return True; -- Error will be detected later
10900 end Is_Valid_Constraint_Kind;
10902 --------------------------
10903 -- Is_Visible_Component --
10904 --------------------------
10906 function Is_Visible_Component (C : Entity_Id) return Boolean is
10907 Original_Comp : Entity_Id := Empty;
10908 Original_Scope : Entity_Id;
10909 Type_Scope : Entity_Id;
10911 function Is_Local_Type (Typ : Entity_Id) return Boolean;
10912 -- Check whether parent type of inherited component is declared locally,
10913 -- possibly within a nested package or instance. The current scope is
10914 -- the derived record itself.
10916 -------------------
10917 -- Is_Local_Type --
10918 -------------------
10920 function Is_Local_Type (Typ : Entity_Id) return Boolean is
10921 Scop : Entity_Id := Scope (Typ);
10924 while Present (Scop)
10925 and then Scop /= Standard_Standard
10927 if Scop = Scope (Current_Scope) then
10931 Scop := Scope (Scop);
10937 -- Start of processing for Is_Visible_Component
10940 if Ekind (C) = E_Component
10941 or else Ekind (C) = E_Discriminant
10943 Original_Comp := Original_Record_Component (C);
10946 if No (Original_Comp) then
10948 -- Premature usage, or previous error
10953 Original_Scope := Scope (Original_Comp);
10954 Type_Scope := Scope (Base_Type (Scope (C)));
10957 -- This test only concerns tagged types
10959 if not Is_Tagged_Type (Original_Scope) then
10962 -- If it is _Parent or _Tag, there is no visibility issue
10964 elsif not Comes_From_Source (Original_Comp) then
10967 -- If we are in the body of an instantiation, the component is visible
10968 -- even when the parent type (possibly defined in an enclosing unit or
10969 -- in a parent unit) might not.
10971 elsif In_Instance_Body then
10974 -- Discriminants are always visible
10976 elsif Ekind (Original_Comp) = E_Discriminant
10977 and then not Has_Unknown_Discriminants (Original_Scope)
10981 -- If the component has been declared in an ancestor which is currently
10982 -- a private type, then it is not visible. The same applies if the
10983 -- component's containing type is not in an open scope and the original
10984 -- component's enclosing type is a visible full type of a private type
10985 -- (which can occur in cases where an attempt is being made to reference
10986 -- a component in a sibling package that is inherited from a visible
10987 -- component of a type in an ancestor package; the component in the
10988 -- sibling package should not be visible even though the component it
10989 -- inherited from is visible). This does not apply however in the case
10990 -- where the scope of the type is a private child unit, or when the
10991 -- parent comes from a local package in which the ancestor is currently
10992 -- visible. The latter suppression of visibility is needed for cases
10993 -- that are tested in B730006.
10995 elsif Is_Private_Type (Original_Scope)
10997 (not Is_Private_Descendant (Type_Scope)
10998 and then not In_Open_Scopes (Type_Scope)
10999 and then Has_Private_Declaration (Original_Scope))
11001 -- If the type derives from an entity in a formal package, there
11002 -- are no additional visible components.
11004 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
11005 N_Formal_Package_Declaration
11009 -- if we are not in the private part of the current package, there
11010 -- are no additional visible components.
11012 elsif Ekind (Scope (Current_Scope)) = E_Package
11013 and then not In_Private_Part (Scope (Current_Scope))
11018 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
11019 and then Is_Local_Type (Type_Scope);
11022 -- There is another weird way in which a component may be invisible
11023 -- when the private and the full view are not derived from the same
11024 -- ancestor. Here is an example :
11026 -- type A1 is tagged record F1 : integer; end record;
11027 -- type A2 is new A1 with record F2 : integer; end record;
11028 -- type T is new A1 with private;
11030 -- type T is new A2 with null record;
11032 -- In this case, the full view of T inherits F1 and F2 but the private
11033 -- view inherits only F1
11037 Ancestor : Entity_Id := Scope (C);
11041 if Ancestor = Original_Scope then
11043 elsif Ancestor = Etype (Ancestor) then
11047 Ancestor := Etype (Ancestor);
11053 end Is_Visible_Component;
11055 --------------------------
11056 -- Make_Class_Wide_Type --
11057 --------------------------
11059 procedure Make_Class_Wide_Type (T : Entity_Id) is
11060 CW_Type : Entity_Id;
11062 Next_E : Entity_Id;
11065 -- The class wide type can have been defined by the partial view in
11066 -- which case everything is already done
11068 if Present (Class_Wide_Type (T)) then
11073 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
11075 -- Inherit root type characteristics
11077 CW_Name := Chars (CW_Type);
11078 Next_E := Next_Entity (CW_Type);
11079 Copy_Node (T, CW_Type);
11080 Set_Comes_From_Source (CW_Type, False);
11081 Set_Chars (CW_Type, CW_Name);
11082 Set_Parent (CW_Type, Parent (T));
11083 Set_Next_Entity (CW_Type, Next_E);
11084 Set_Has_Delayed_Freeze (CW_Type);
11086 -- Customize the class-wide type: It has no prim. op., it cannot be
11087 -- abstract and its Etype points back to the specific root type.
11089 Set_Ekind (CW_Type, E_Class_Wide_Type);
11090 Set_Is_Tagged_Type (CW_Type, True);
11091 Set_Primitive_Operations (CW_Type, New_Elmt_List);
11092 Set_Is_Abstract (CW_Type, False);
11093 Set_Is_Constrained (CW_Type, False);
11094 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
11095 Init_Size_Align (CW_Type);
11097 if Ekind (T) = E_Class_Wide_Subtype then
11098 Set_Etype (CW_Type, Etype (Base_Type (T)));
11100 Set_Etype (CW_Type, T);
11103 -- If this is the class_wide type of a constrained subtype, it does
11104 -- not have discriminants.
11106 Set_Has_Discriminants (CW_Type,
11107 Has_Discriminants (T) and then not Is_Constrained (T));
11109 Set_Has_Unknown_Discriminants (CW_Type, True);
11110 Set_Class_Wide_Type (T, CW_Type);
11111 Set_Equivalent_Type (CW_Type, Empty);
11113 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
11115 Set_Class_Wide_Type (CW_Type, CW_Type);
11116 end Make_Class_Wide_Type;
11122 procedure Make_Index
11124 Related_Nod : Node_Id;
11125 Related_Id : Entity_Id := Empty;
11126 Suffix_Index : Nat := 1)
11130 Def_Id : Entity_Id := Empty;
11131 Found : Boolean := False;
11134 -- For a discrete range used in a constrained array definition and
11135 -- defined by a range, an implicit conversion to the predefined type
11136 -- INTEGER is assumed if each bound is either a numeric literal, a named
11137 -- number, or an attribute, and the type of both bounds (prior to the
11138 -- implicit conversion) is the type universal_integer. Otherwise, both
11139 -- bounds must be of the same discrete type, other than universal
11140 -- integer; this type must be determinable independently of the
11141 -- context, but using the fact that the type must be discrete and that
11142 -- both bounds must have the same type.
11144 -- Character literals also have a universal type in the absence of
11145 -- of additional context, and are resolved to Standard_Character.
11147 if Nkind (I) = N_Range then
11149 -- The index is given by a range constraint. The bounds are known
11150 -- to be of a consistent type.
11152 if not Is_Overloaded (I) then
11155 -- If the bounds are universal, choose the specific predefined
11158 if T = Universal_Integer then
11159 T := Standard_Integer;
11161 elsif T = Any_Character then
11163 if Ada_Version >= Ada_95 then
11165 ("ambiguous character literals (could be Wide_Character)",
11169 T := Standard_Character;
11176 Ind : Interp_Index;
11180 Get_First_Interp (I, Ind, It);
11182 while Present (It.Typ) loop
11183 if Is_Discrete_Type (It.Typ) then
11186 and then not Covers (It.Typ, T)
11187 and then not Covers (T, It.Typ)
11189 Error_Msg_N ("ambiguous bounds in discrete range", I);
11197 Get_Next_Interp (Ind, It);
11200 if T = Any_Type then
11201 Error_Msg_N ("discrete type required for range", I);
11202 Set_Etype (I, Any_Type);
11205 elsif T = Universal_Integer then
11206 T := Standard_Integer;
11211 if not Is_Discrete_Type (T) then
11212 Error_Msg_N ("discrete type required for range", I);
11213 Set_Etype (I, Any_Type);
11217 if Nkind (Low_Bound (I)) = N_Attribute_Reference
11218 and then Attribute_Name (Low_Bound (I)) = Name_First
11219 and then Is_Entity_Name (Prefix (Low_Bound (I)))
11220 and then Is_Type (Entity (Prefix (Low_Bound (I))))
11221 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I))))
11223 -- The type of the index will be the type of the prefix, as long
11224 -- as the upper bound is 'Last of the same type.
11226 Def_Id := Entity (Prefix (Low_Bound (I)));
11228 if Nkind (High_Bound (I)) /= N_Attribute_Reference
11229 or else Attribute_Name (High_Bound (I)) /= Name_Last
11230 or else not Is_Entity_Name (Prefix (High_Bound (I)))
11231 or else Entity (Prefix (High_Bound (I))) /= Def_Id
11238 Process_Range_Expr_In_Decl (R, T);
11240 elsif Nkind (I) = N_Subtype_Indication then
11242 -- The index is given by a subtype with a range constraint
11244 T := Base_Type (Entity (Subtype_Mark (I)));
11246 if not Is_Discrete_Type (T) then
11247 Error_Msg_N ("discrete type required for range", I);
11248 Set_Etype (I, Any_Type);
11252 R := Range_Expression (Constraint (I));
11255 Process_Range_Expr_In_Decl (R, Entity (Subtype_Mark (I)));
11257 elsif Nkind (I) = N_Attribute_Reference then
11259 -- The parser guarantees that the attribute is a RANGE attribute
11261 -- If the node denotes the range of a type mark, that is also the
11262 -- resulting type, and we do no need to create an Itype for it.
11264 if Is_Entity_Name (Prefix (I))
11265 and then Comes_From_Source (I)
11266 and then Is_Type (Entity (Prefix (I)))
11267 and then Is_Discrete_Type (Entity (Prefix (I)))
11269 Def_Id := Entity (Prefix (I));
11272 Analyze_And_Resolve (I);
11276 -- If none of the above, must be a subtype. We convert this to a
11277 -- range attribute reference because in the case of declared first
11278 -- named subtypes, the types in the range reference can be different
11279 -- from the type of the entity. A range attribute normalizes the
11280 -- reference and obtains the correct types for the bounds.
11282 -- This transformation is in the nature of an expansion, is only
11283 -- done if expansion is active. In particular, it is not done on
11284 -- formal generic types, because we need to retain the name of the
11285 -- original index for instantiation purposes.
11288 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
11289 Error_Msg_N ("invalid subtype mark in discrete range ", I);
11290 Set_Etype (I, Any_Integer);
11294 -- The type mark may be that of an incomplete type. It is only
11295 -- now that we can get the full view, previous analysis does
11296 -- not look specifically for a type mark.
11298 Set_Entity (I, Get_Full_View (Entity (I)));
11299 Set_Etype (I, Entity (I));
11300 Def_Id := Entity (I);
11302 if not Is_Discrete_Type (Def_Id) then
11303 Error_Msg_N ("discrete type required for index", I);
11304 Set_Etype (I, Any_Type);
11309 if Expander_Active then
11311 Make_Attribute_Reference (Sloc (I),
11312 Attribute_Name => Name_Range,
11313 Prefix => Relocate_Node (I)));
11315 -- The original was a subtype mark that does not freeze. This
11316 -- means that the rewritten version must not freeze either.
11318 Set_Must_Not_Freeze (I);
11319 Set_Must_Not_Freeze (Prefix (I));
11321 -- Is order critical??? if so, document why, if not
11322 -- use Analyze_And_Resolve
11329 -- If expander is inactive, type is legal, nothing else to construct
11336 if not Is_Discrete_Type (T) then
11337 Error_Msg_N ("discrete type required for range", I);
11338 Set_Etype (I, Any_Type);
11341 elsif T = Any_Type then
11342 Set_Etype (I, Any_Type);
11346 -- We will now create the appropriate Itype to describe the range, but
11347 -- first a check. If we originally had a subtype, then we just label
11348 -- the range with this subtype. Not only is there no need to construct
11349 -- a new subtype, but it is wrong to do so for two reasons:
11351 -- 1. A legality concern, if we have a subtype, it must not freeze,
11352 -- and the Itype would cause freezing incorrectly
11354 -- 2. An efficiency concern, if we created an Itype, it would not be
11355 -- recognized as the same type for the purposes of eliminating
11356 -- checks in some circumstances.
11358 -- We signal this case by setting the subtype entity in Def_Id
11360 if No (Def_Id) then
11362 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
11363 Set_Etype (Def_Id, Base_Type (T));
11365 if Is_Signed_Integer_Type (T) then
11366 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
11368 elsif Is_Modular_Integer_Type (T) then
11369 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
11372 Set_Ekind (Def_Id, E_Enumeration_Subtype);
11373 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
11374 Set_First_Literal (Def_Id, First_Literal (T));
11377 Set_Size_Info (Def_Id, (T));
11378 Set_RM_Size (Def_Id, RM_Size (T));
11379 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11381 Set_Scalar_Range (Def_Id, R);
11382 Conditional_Delay (Def_Id, T);
11384 -- In the subtype indication case, if the immediate parent of the
11385 -- new subtype is non-static, then the subtype we create is non-
11386 -- static, even if its bounds are static.
11388 if Nkind (I) = N_Subtype_Indication
11389 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
11391 Set_Is_Non_Static_Subtype (Def_Id);
11395 -- Final step is to label the index with this constructed type
11397 Set_Etype (I, Def_Id);
11400 ------------------------------
11401 -- Modular_Type_Declaration --
11402 ------------------------------
11404 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
11405 Mod_Expr : constant Node_Id := Expression (Def);
11408 procedure Set_Modular_Size (Bits : Int);
11409 -- Sets RM_Size to Bits, and Esize to normal word size above this
11411 ----------------------
11412 -- Set_Modular_Size --
11413 ----------------------
11415 procedure Set_Modular_Size (Bits : Int) is
11417 Set_RM_Size (T, UI_From_Int (Bits));
11422 elsif Bits <= 16 then
11423 Init_Esize (T, 16);
11425 elsif Bits <= 32 then
11426 Init_Esize (T, 32);
11429 Init_Esize (T, System_Max_Binary_Modulus_Power);
11431 end Set_Modular_Size;
11433 -- Start of processing for Modular_Type_Declaration
11436 Analyze_And_Resolve (Mod_Expr, Any_Integer);
11438 Set_Ekind (T, E_Modular_Integer_Type);
11439 Init_Alignment (T);
11440 Set_Is_Constrained (T);
11442 if not Is_OK_Static_Expression (Mod_Expr) then
11443 Flag_Non_Static_Expr
11444 ("non-static expression used for modular type bound!", Mod_Expr);
11445 M_Val := 2 ** System_Max_Binary_Modulus_Power;
11447 M_Val := Expr_Value (Mod_Expr);
11451 Error_Msg_N ("modulus value must be positive", Mod_Expr);
11452 M_Val := 2 ** System_Max_Binary_Modulus_Power;
11455 Set_Modulus (T, M_Val);
11457 -- Create bounds for the modular type based on the modulus given in
11458 -- the type declaration and then analyze and resolve those bounds.
11460 Set_Scalar_Range (T,
11461 Make_Range (Sloc (Mod_Expr),
11463 Make_Integer_Literal (Sloc (Mod_Expr), 0),
11465 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
11467 -- Properly analyze the literals for the range. We do this manually
11468 -- because we can't go calling Resolve, since we are resolving these
11469 -- bounds with the type, and this type is certainly not complete yet!
11471 Set_Etype (Low_Bound (Scalar_Range (T)), T);
11472 Set_Etype (High_Bound (Scalar_Range (T)), T);
11473 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
11474 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
11476 -- Loop through powers of two to find number of bits required
11478 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
11482 if M_Val = 2 ** Bits then
11483 Set_Modular_Size (Bits);
11488 elsif M_Val < 2 ** Bits then
11489 Set_Non_Binary_Modulus (T);
11491 if Bits > System_Max_Nonbinary_Modulus_Power then
11492 Error_Msg_Uint_1 :=
11493 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
11495 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
11496 Set_Modular_Size (System_Max_Binary_Modulus_Power);
11500 -- In the non-binary case, set size as per RM 13.3(55)
11502 Set_Modular_Size (Bits);
11509 -- If we fall through, then the size exceed System.Max_Binary_Modulus
11510 -- so we just signal an error and set the maximum size.
11512 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
11513 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
11515 Set_Modular_Size (System_Max_Binary_Modulus_Power);
11516 Init_Alignment (T);
11518 end Modular_Type_Declaration;
11520 --------------------------
11521 -- New_Concatenation_Op --
11522 --------------------------
11524 procedure New_Concatenation_Op (Typ : Entity_Id) is
11525 Loc : constant Source_Ptr := Sloc (Typ);
11528 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
11529 -- Create abbreviated declaration for the formal of a predefined
11530 -- Operator 'Op' of type 'Typ'
11532 --------------------
11533 -- Make_Op_Formal --
11534 --------------------
11536 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
11537 Formal : Entity_Id;
11539 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
11540 Set_Etype (Formal, Typ);
11541 Set_Mechanism (Formal, Default_Mechanism);
11543 end Make_Op_Formal;
11545 -- Start of processing for New_Concatenation_Op
11548 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
11550 Set_Ekind (Op, E_Operator);
11551 Set_Scope (Op, Current_Scope);
11552 Set_Etype (Op, Typ);
11553 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
11554 Set_Is_Immediately_Visible (Op);
11555 Set_Is_Intrinsic_Subprogram (Op);
11556 Set_Has_Completion (Op);
11557 Append_Entity (Op, Current_Scope);
11559 Set_Name_Entity_Id (Name_Op_Concat, Op);
11561 Append_Entity (Make_Op_Formal (Typ, Op), Op);
11562 Append_Entity (Make_Op_Formal (Typ, Op), Op);
11563 end New_Concatenation_Op;
11565 -------------------------------------------
11566 -- Ordinary_Fixed_Point_Type_Declaration --
11567 -------------------------------------------
11569 procedure Ordinary_Fixed_Point_Type_Declaration
11573 Loc : constant Source_Ptr := Sloc (Def);
11574 Delta_Expr : constant Node_Id := Delta_Expression (Def);
11575 RRS : constant Node_Id := Real_Range_Specification (Def);
11576 Implicit_Base : Entity_Id;
11583 Check_Restriction (No_Fixed_Point, Def);
11585 -- Create implicit base type
11588 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
11589 Set_Etype (Implicit_Base, Implicit_Base);
11591 -- Analyze and process delta expression
11593 Analyze_And_Resolve (Delta_Expr, Any_Real);
11595 Check_Delta_Expression (Delta_Expr);
11596 Delta_Val := Expr_Value_R (Delta_Expr);
11598 Set_Delta_Value (Implicit_Base, Delta_Val);
11600 -- Compute default small from given delta, which is the largest power
11601 -- of two that does not exceed the given delta value.
11604 Tmp : Ureal := Ureal_1;
11608 if Delta_Val < Ureal_1 then
11609 while Delta_Val < Tmp loop
11610 Tmp := Tmp / Ureal_2;
11611 Scale := Scale + 1;
11616 Tmp := Tmp * Ureal_2;
11617 exit when Tmp > Delta_Val;
11618 Scale := Scale - 1;
11622 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
11625 Set_Small_Value (Implicit_Base, Small_Val);
11627 -- If no range was given, set a dummy range
11629 if RRS <= Empty_Or_Error then
11630 Low_Val := -Small_Val;
11631 High_Val := Small_Val;
11633 -- Otherwise analyze and process given range
11637 Low : constant Node_Id := Low_Bound (RRS);
11638 High : constant Node_Id := High_Bound (RRS);
11641 Analyze_And_Resolve (Low, Any_Real);
11642 Analyze_And_Resolve (High, Any_Real);
11643 Check_Real_Bound (Low);
11644 Check_Real_Bound (High);
11646 -- Obtain and set the range
11648 Low_Val := Expr_Value_R (Low);
11649 High_Val := Expr_Value_R (High);
11651 if Low_Val > High_Val then
11652 Error_Msg_NE ("?fixed point type& has null range", Def, T);
11657 -- The range for both the implicit base and the declared first subtype
11658 -- cannot be set yet, so we use the special routine Set_Fixed_Range to
11659 -- set a temporary range in place. Note that the bounds of the base
11660 -- type will be widened to be symmetrical and to fill the available
11661 -- bits when the type is frozen.
11663 -- We could do this with all discrete types, and probably should, but
11664 -- we absolutely have to do it for fixed-point, since the end-points
11665 -- of the range and the size are determined by the small value, which
11666 -- could be reset before the freeze point.
11668 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
11669 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
11671 Init_Size_Align (Implicit_Base);
11673 -- Complete definition of first subtype
11675 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
11676 Set_Etype (T, Implicit_Base);
11677 Init_Size_Align (T);
11678 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
11679 Set_Small_Value (T, Small_Val);
11680 Set_Delta_Value (T, Delta_Val);
11681 Set_Is_Constrained (T);
11683 end Ordinary_Fixed_Point_Type_Declaration;
11685 ----------------------------------------
11686 -- Prepare_Private_Subtype_Completion --
11687 ----------------------------------------
11689 procedure Prepare_Private_Subtype_Completion
11691 Related_Nod : Node_Id)
11693 Id_B : constant Entity_Id := Base_Type (Id);
11694 Full_B : constant Entity_Id := Full_View (Id_B);
11698 if Present (Full_B) then
11700 -- The Base_Type is already completed, we can complete the subtype
11701 -- now. We have to create a new entity with the same name, Thus we
11702 -- can't use Create_Itype.
11704 -- This is messy, should be fixed ???
11706 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
11707 Set_Is_Itype (Full);
11708 Set_Associated_Node_For_Itype (Full, Related_Nod);
11709 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
11712 -- The parent subtype may be private, but the base might not, in some
11713 -- nested instances. In that case, the subtype does not need to be
11714 -- exchanged. It would still be nice to make private subtypes and their
11715 -- bases consistent at all times ???
11717 if Is_Private_Type (Id_B) then
11718 Append_Elmt (Id, Private_Dependents (Id_B));
11721 end Prepare_Private_Subtype_Completion;
11723 ---------------------------
11724 -- Process_Discriminants --
11725 ---------------------------
11727 procedure Process_Discriminants
11729 Prev : Entity_Id := Empty)
11731 Elist : constant Elist_Id := New_Elmt_List;
11734 Discr_Number : Uint;
11735 Discr_Type : Entity_Id;
11736 Default_Present : Boolean := False;
11737 Default_Not_Present : Boolean := False;
11740 -- A composite type other than an array type can have discriminants.
11741 -- Discriminants of non-limited types must have a discrete type.
11742 -- On entry, the current scope is the composite type.
11744 -- The discriminants are initially entered into the scope of the type
11745 -- via Enter_Name with the default Ekind of E_Void to prevent premature
11746 -- use, as explained at the end of this procedure.
11748 Discr := First (Discriminant_Specifications (N));
11749 while Present (Discr) loop
11750 Enter_Name (Defining_Identifier (Discr));
11752 -- For navigation purposes we add a reference to the discriminant
11753 -- in the entity for the type. If the current declaration is a
11754 -- completion, place references on the partial view. Otherwise the
11755 -- type is the current scope.
11757 if Present (Prev) then
11759 -- The references go on the partial view, if present. If the
11760 -- partial view has discriminants, the references have been
11761 -- generated already.
11763 if not Has_Discriminants (Prev) then
11764 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
11768 (Current_Scope, Defining_Identifier (Discr), 'd');
11771 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
11772 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
11774 -- Ada 2005 (AI-254)
11776 if Present (Access_To_Subprogram_Definition
11777 (Discriminant_Type (Discr)))
11778 and then Protected_Present (Access_To_Subprogram_Definition
11779 (Discriminant_Type (Discr)))
11782 Replace_Anonymous_Access_To_Protected_Subprogram
11783 (Discr, Discr_Type);
11787 Find_Type (Discriminant_Type (Discr));
11788 Discr_Type := Etype (Discriminant_Type (Discr));
11790 if Error_Posted (Discriminant_Type (Discr)) then
11791 Discr_Type := Any_Type;
11795 if Is_Access_Type (Discr_Type) then
11797 -- Ada 2005 (AI-230): Access discriminant allowed in non-limited
11800 if Ada_Version < Ada_05 then
11801 Check_Access_Discriminant_Requires_Limited
11802 (Discr, Discriminant_Type (Discr));
11805 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
11807 ("(Ada 83) access discriminant not allowed", Discr);
11810 elsif not Is_Discrete_Type (Discr_Type) then
11811 Error_Msg_N ("discriminants must have a discrete or access type",
11812 Discriminant_Type (Discr));
11815 Set_Etype (Defining_Identifier (Discr), Discr_Type);
11817 -- If a discriminant specification includes the assignment compound
11818 -- delimiter followed by an expression, the expression is the default
11819 -- expression of the discriminant; the default expression must be of
11820 -- the type of the discriminant. (RM 3.7.1) Since this expression is
11821 -- a default expression, we do the special preanalysis, since this
11822 -- expression does not freeze (see "Handling of Default and Per-
11823 -- Object Expressions" in spec of package Sem).
11825 if Present (Expression (Discr)) then
11826 Analyze_Per_Use_Expression (Expression (Discr), Discr_Type);
11828 if Nkind (N) = N_Formal_Type_Declaration then
11830 ("discriminant defaults not allowed for formal type",
11831 Expression (Discr));
11833 -- Tagged types cannot have defaulted discriminants, but a
11834 -- non-tagged private type with defaulted discriminants
11835 -- can have a tagged completion.
11837 elsif Is_Tagged_Type (Current_Scope)
11838 and then Comes_From_Source (N)
11841 ("discriminants of tagged type cannot have defaults",
11842 Expression (Discr));
11845 Default_Present := True;
11846 Append_Elmt (Expression (Discr), Elist);
11848 -- Tag the defining identifiers for the discriminants with
11849 -- their corresponding default expressions from the tree.
11851 Set_Discriminant_Default_Value
11852 (Defining_Identifier (Discr), Expression (Discr));
11856 Default_Not_Present := True;
11859 -- Ada 2005 (AI-231): Set the null-excluding attribute and carry
11860 -- out some static checks.
11862 if Ada_Version >= Ada_05
11863 and then (Null_Exclusion_Present (Discr)
11864 or else Can_Never_Be_Null (Discr_Type))
11866 Set_Can_Never_Be_Null (Defining_Identifier (Discr));
11867 Null_Exclusion_Static_Checks (Discr);
11873 -- An element list consisting of the default expressions of the
11874 -- discriminants is constructed in the above loop and used to set
11875 -- the Discriminant_Constraint attribute for the type. If an object
11876 -- is declared of this (record or task) type without any explicit
11877 -- discriminant constraint given, this element list will form the
11878 -- actual parameters for the corresponding initialization procedure
11881 Set_Discriminant_Constraint (Current_Scope, Elist);
11882 Set_Stored_Constraint (Current_Scope, No_Elist);
11884 -- Default expressions must be provided either for all or for none
11885 -- of the discriminants of a discriminant part. (RM 3.7.1)
11887 if Default_Present and then Default_Not_Present then
11889 ("incomplete specification of defaults for discriminants", N);
11892 -- The use of the name of a discriminant is not allowed in default
11893 -- expressions of a discriminant part if the specification of the
11894 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
11896 -- To detect this, the discriminant names are entered initially with an
11897 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
11898 -- attempt to use a void entity (for example in an expression that is
11899 -- type-checked) produces the error message: premature usage. Now after
11900 -- completing the semantic analysis of the discriminant part, we can set
11901 -- the Ekind of all the discriminants appropriately.
11903 Discr := First (Discriminant_Specifications (N));
11904 Discr_Number := Uint_1;
11906 while Present (Discr) loop
11907 Id := Defining_Identifier (Discr);
11908 Set_Ekind (Id, E_Discriminant);
11909 Init_Component_Location (Id);
11911 Set_Discriminant_Number (Id, Discr_Number);
11913 -- Make sure this is always set, even in illegal programs
11915 Set_Corresponding_Discriminant (Id, Empty);
11917 -- Initialize the Original_Record_Component to the entity itself.
11918 -- Inherit_Components will propagate the right value to
11919 -- discriminants in derived record types.
11921 Set_Original_Record_Component (Id, Id);
11923 -- Create the discriminal for the discriminant
11925 Build_Discriminal (Id);
11928 Discr_Number := Discr_Number + 1;
11931 Set_Has_Discriminants (Current_Scope);
11932 end Process_Discriminants;
11934 -----------------------
11935 -- Process_Full_View --
11936 -----------------------
11938 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
11939 Priv_Parent : Entity_Id;
11940 Full_Parent : Entity_Id;
11941 Full_Indic : Node_Id;
11944 -- First some sanity checks that must be done after semantic
11945 -- decoration of the full view and thus cannot be placed with other
11946 -- similar checks in Find_Type_Name
11948 if not Is_Limited_Type (Priv_T)
11949 and then (Is_Limited_Type (Full_T)
11950 or else Is_Limited_Composite (Full_T))
11953 ("completion of nonlimited type cannot be limited", Full_T);
11954 Explain_Limited_Type (Full_T, Full_T);
11956 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
11958 ("completion of nonabstract type cannot be abstract", Full_T);
11960 elsif Is_Tagged_Type (Priv_T)
11961 and then Is_Limited_Type (Priv_T)
11962 and then not Is_Limited_Type (Full_T)
11964 -- GNAT allow its own definition of Limited_Controlled to disobey
11965 -- this rule in order in ease the implementation. The next test is
11966 -- safe because Root_Controlled is defined in a private system child
11968 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
11969 Set_Is_Limited_Composite (Full_T);
11972 ("completion of limited tagged type must be limited", Full_T);
11975 elsif Is_Generic_Type (Priv_T) then
11976 Error_Msg_N ("generic type cannot have a completion", Full_T);
11979 if Is_Tagged_Type (Priv_T)
11980 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
11981 and then Is_Derived_Type (Full_T)
11983 Priv_Parent := Etype (Priv_T);
11985 -- The full view of a private extension may have been transformed
11986 -- into an unconstrained derived type declaration and a subtype
11987 -- declaration (see build_derived_record_type for details).
11989 if Nkind (N) = N_Subtype_Declaration then
11990 Full_Indic := Subtype_Indication (N);
11991 Full_Parent := Etype (Base_Type (Full_T));
11993 Full_Indic := Subtype_Indication (Type_Definition (N));
11994 Full_Parent := Etype (Full_T);
11997 -- Check that the parent type of the full type is a descendant of
11998 -- the ancestor subtype given in the private extension. If either
11999 -- entity has an Etype equal to Any_Type then we had some previous
12000 -- error situation [7.3(8)].
12002 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
12005 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
12007 ("parent of full type must descend from parent"
12008 & " of private extension", Full_Indic);
12010 -- Check the rules of 7.3(10): if the private extension inherits
12011 -- known discriminants, then the full type must also inherit those
12012 -- discriminants from the same (ancestor) type, and the parent
12013 -- subtype of the full type must be constrained if and only if
12014 -- the ancestor subtype of the private extension is constrained.
12016 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
12017 and then not Has_Unknown_Discriminants (Priv_T)
12018 and then Has_Discriminants (Base_Type (Priv_Parent))
12021 Priv_Indic : constant Node_Id :=
12022 Subtype_Indication (Parent (Priv_T));
12024 Priv_Constr : constant Boolean :=
12025 Is_Constrained (Priv_Parent)
12027 Nkind (Priv_Indic) = N_Subtype_Indication
12028 or else Is_Constrained (Entity (Priv_Indic));
12030 Full_Constr : constant Boolean :=
12031 Is_Constrained (Full_Parent)
12033 Nkind (Full_Indic) = N_Subtype_Indication
12034 or else Is_Constrained (Entity (Full_Indic));
12036 Priv_Discr : Entity_Id;
12037 Full_Discr : Entity_Id;
12040 Priv_Discr := First_Discriminant (Priv_Parent);
12041 Full_Discr := First_Discriminant (Full_Parent);
12043 while Present (Priv_Discr) and then Present (Full_Discr) loop
12044 if Original_Record_Component (Priv_Discr) =
12045 Original_Record_Component (Full_Discr)
12047 Corresponding_Discriminant (Priv_Discr) =
12048 Corresponding_Discriminant (Full_Discr)
12055 Next_Discriminant (Priv_Discr);
12056 Next_Discriminant (Full_Discr);
12059 if Present (Priv_Discr) or else Present (Full_Discr) then
12061 ("full view must inherit discriminants of the parent type"
12062 & " used in the private extension", Full_Indic);
12064 elsif Priv_Constr and then not Full_Constr then
12066 ("parent subtype of full type must be constrained",
12069 elsif Full_Constr and then not Priv_Constr then
12071 ("parent subtype of full type must be unconstrained",
12076 -- Check the rules of 7.3(12): if a partial view has neither known
12077 -- or unknown discriminants, then the full type declaration shall
12078 -- define a definite subtype.
12080 elsif not Has_Unknown_Discriminants (Priv_T)
12081 and then not Has_Discriminants (Priv_T)
12082 and then not Is_Constrained (Full_T)
12085 ("full view must define a constrained type if partial view"
12086 & " has no discriminants", Full_T);
12089 -- ??????? Do we implement the following properly ?????
12090 -- If the ancestor subtype of a private extension has constrained
12091 -- discriminants, then the parent subtype of the full view shall
12092 -- impose a statically matching constraint on those discriminants
12096 -- For untagged types, verify that a type without discriminants
12097 -- is not completed with an unconstrained type.
12099 if not Is_Indefinite_Subtype (Priv_T)
12100 and then Is_Indefinite_Subtype (Full_T)
12102 Error_Msg_N ("full view of type must be definite subtype", Full_T);
12106 -- Create a full declaration for all its subtypes recorded in
12107 -- Private_Dependents and swap them similarly to the base type. These
12108 -- are subtypes that have been define before the full declaration of
12109 -- the private type. We also swap the entry in Private_Dependents list
12110 -- so we can properly restore the private view on exit from the scope.
12113 Priv_Elmt : Elmt_Id;
12118 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
12119 while Present (Priv_Elmt) loop
12120 Priv := Node (Priv_Elmt);
12122 if Ekind (Priv) = E_Private_Subtype
12123 or else Ekind (Priv) = E_Limited_Private_Subtype
12124 or else Ekind (Priv) = E_Record_Subtype_With_Private
12126 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
12127 Set_Is_Itype (Full);
12128 Set_Parent (Full, Parent (Priv));
12129 Set_Associated_Node_For_Itype (Full, N);
12131 -- Now we need to complete the private subtype, but since the
12132 -- base type has already been swapped, we must also swap the
12133 -- subtypes (and thus, reverse the arguments in the call to
12134 -- Complete_Private_Subtype).
12136 Copy_And_Swap (Priv, Full);
12137 Complete_Private_Subtype (Full, Priv, Full_T, N);
12138 Replace_Elmt (Priv_Elmt, Full);
12141 Next_Elmt (Priv_Elmt);
12145 -- If the private view was tagged, copy the new Primitive
12146 -- operations from the private view to the full view.
12148 if Is_Tagged_Type (Full_T) then
12150 Priv_List : Elist_Id;
12151 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
12154 D_Type : Entity_Id;
12157 if Is_Tagged_Type (Priv_T) then
12158 Priv_List := Primitive_Operations (Priv_T);
12160 P1 := First_Elmt (Priv_List);
12161 while Present (P1) loop
12164 -- Transfer explicit primitives, not those inherited from
12165 -- parent of partial view, which will be re-inherited on
12168 if Comes_From_Source (Prim) then
12169 P2 := First_Elmt (Full_List);
12170 while Present (P2) and then Node (P2) /= Prim loop
12174 -- If not found, that is a new one
12177 Append_Elmt (Prim, Full_List);
12185 -- In this case the partial view is untagged, so here we
12186 -- locate all of the earlier primitives that need to be
12187 -- treated as dispatching (those that appear between the two
12188 -- views). Note that these additional operations must all be
12189 -- new operations (any earlier operations that override
12190 -- inherited operations of the full view will already have
12191 -- been inserted in the primitives list and marked as
12192 -- dispatching by Check_Operation_From_Private_View. Note that
12193 -- implicit "/=" operators are excluded from being added to
12194 -- the primitives list since they shouldn't be treated as
12195 -- dispatching (tagged "/=" is handled specially).
12197 Prim := Next_Entity (Full_T);
12198 while Present (Prim) and then Prim /= Priv_T loop
12199 if Ekind (Prim) = E_Procedure
12201 Ekind (Prim) = E_Function
12204 D_Type := Find_Dispatching_Type (Prim);
12207 and then (Chars (Prim) /= Name_Op_Ne
12208 or else Comes_From_Source (Prim))
12210 Check_Controlling_Formals (Full_T, Prim);
12212 if not Is_Dispatching_Operation (Prim) then
12213 Append_Elmt (Prim, Full_List);
12214 Set_Is_Dispatching_Operation (Prim, True);
12215 Set_DT_Position (Prim, No_Uint);
12218 elsif Is_Dispatching_Operation (Prim)
12219 and then D_Type /= Full_T
12222 -- Verify that it is not otherwise controlled by
12223 -- a formal or a return value ot type T.
12225 Check_Controlling_Formals (D_Type, Prim);
12229 Next_Entity (Prim);
12233 -- For the tagged case, the two views can share the same
12234 -- Primitive Operation list and the same class wide type.
12235 -- Update attributes of the class-wide type which depend on
12236 -- the full declaration.
12238 if Is_Tagged_Type (Priv_T) then
12239 Set_Primitive_Operations (Priv_T, Full_List);
12240 Set_Class_Wide_Type
12241 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
12243 -- Any other attributes should be propagated to C_W ???
12245 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
12250 end Process_Full_View;
12252 -----------------------------------
12253 -- Process_Incomplete_Dependents --
12254 -----------------------------------
12256 procedure Process_Incomplete_Dependents
12258 Full_T : Entity_Id;
12261 Inc_Elmt : Elmt_Id;
12262 Priv_Dep : Entity_Id;
12263 New_Subt : Entity_Id;
12265 Disc_Constraint : Elist_Id;
12268 if No (Private_Dependents (Inc_T)) then
12272 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
12274 -- Itypes that may be generated by the completion of an incomplete
12275 -- subtype are not used by the back-end and not attached to the tree.
12276 -- They are created only for constraint-checking purposes.
12279 while Present (Inc_Elmt) loop
12280 Priv_Dep := Node (Inc_Elmt);
12282 if Ekind (Priv_Dep) = E_Subprogram_Type then
12284 -- An Access_To_Subprogram type may have a return type or a
12285 -- parameter type that is incomplete. Replace with the full view.
12287 if Etype (Priv_Dep) = Inc_T then
12288 Set_Etype (Priv_Dep, Full_T);
12292 Formal : Entity_Id;
12295 Formal := First_Formal (Priv_Dep);
12297 while Present (Formal) loop
12299 if Etype (Formal) = Inc_T then
12300 Set_Etype (Formal, Full_T);
12303 Next_Formal (Formal);
12307 elsif Is_Overloadable (Priv_Dep) then
12309 if Is_Tagged_Type (Full_T) then
12311 -- Subprogram has an access parameter whose designated type
12312 -- was incomplete. Reexamine declaration now, because it may
12313 -- be a primitive operation of the full type.
12315 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
12316 Set_Is_Dispatching_Operation (Priv_Dep);
12317 Check_Controlling_Formals (Full_T, Priv_Dep);
12320 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
12322 -- Can happen during processing of a body before the completion
12323 -- of a TA type. Ignore, because spec is also on dependent list.
12327 -- Dependent is a subtype
12330 -- We build a new subtype indication using the full view of the
12331 -- incomplete parent. The discriminant constraints have been
12332 -- elaborated already at the point of the subtype declaration.
12334 New_Subt := Create_Itype (E_Void, N);
12336 if Has_Discriminants (Full_T) then
12337 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
12339 Disc_Constraint := No_Elist;
12342 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
12343 Set_Full_View (Priv_Dep, New_Subt);
12346 Next_Elmt (Inc_Elmt);
12348 end Process_Incomplete_Dependents;
12350 --------------------------------
12351 -- Process_Range_Expr_In_Decl --
12352 --------------------------------
12354 procedure Process_Range_Expr_In_Decl
12357 Check_List : List_Id := Empty_List;
12358 R_Check_Off : Boolean := False)
12361 R_Checks : Check_Result;
12362 Type_Decl : Node_Id;
12363 Def_Id : Entity_Id;
12366 Analyze_And_Resolve (R, Base_Type (T));
12368 if Nkind (R) = N_Range then
12369 Lo := Low_Bound (R);
12370 Hi := High_Bound (R);
12372 -- If there were errors in the declaration, try and patch up some
12373 -- common mistakes in the bounds. The cases handled are literals
12374 -- which are Integer where the expected type is Real and vice versa.
12375 -- These corrections allow the compilation process to proceed further
12376 -- along since some basic assumptions of the format of the bounds
12379 if Etype (R) = Any_Type then
12381 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
12383 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
12385 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
12387 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
12389 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
12391 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
12393 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
12395 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
12402 -- If the bounds of the range have been mistakenly given as string
12403 -- literals (perhaps in place of character literals), then an error
12404 -- has already been reported, but we rewrite the string literal as a
12405 -- bound of the range's type to avoid blowups in later processing
12406 -- that looks at static values.
12408 if Nkind (Lo) = N_String_Literal then
12410 Make_Attribute_Reference (Sloc (Lo),
12411 Attribute_Name => Name_First,
12412 Prefix => New_Reference_To (T, Sloc (Lo))));
12413 Analyze_And_Resolve (Lo);
12416 if Nkind (Hi) = N_String_Literal then
12418 Make_Attribute_Reference (Sloc (Hi),
12419 Attribute_Name => Name_First,
12420 Prefix => New_Reference_To (T, Sloc (Hi))));
12421 Analyze_And_Resolve (Hi);
12424 -- If bounds aren't scalar at this point then exit, avoiding
12425 -- problems with further processing of the range in this procedure.
12427 if not Is_Scalar_Type (Etype (Lo)) then
12431 -- Resolve (actually Sem_Eval) has checked that the bounds are in
12432 -- then range of the base type. Here we check whether the bounds
12433 -- are in the range of the subtype itself. Note that if the bounds
12434 -- represent the null range the Constraint_Error exception should
12437 -- ??? The following code should be cleaned up as follows
12439 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
12440 -- is done in the call to Range_Check (R, T); below
12442 -- 2. The use of R_Check_Off should be investigated and possibly
12443 -- removed, this would clean up things a bit.
12445 if Is_Null_Range (Lo, Hi) then
12449 -- Capture values of bounds and generate temporaries for them
12450 -- if needed, before applying checks, since checks may cause
12451 -- duplication of the expression without forcing evaluation.
12453 if Expander_Active then
12454 Force_Evaluation (Lo);
12455 Force_Evaluation (Hi);
12458 -- We use a flag here instead of suppressing checks on the
12459 -- type because the type we check against isn't necessarily
12460 -- the place where we put the check.
12462 if not R_Check_Off then
12463 R_Checks := Range_Check (R, T);
12464 Type_Decl := Parent (R);
12466 -- Look up tree to find an appropriate insertion point.
12467 -- This seems really junk code, and very brittle, couldn't
12468 -- we just use an insert actions call of some kind ???
12470 while Present (Type_Decl) and then not
12471 (Nkind (Type_Decl) = N_Full_Type_Declaration
12473 Nkind (Type_Decl) = N_Subtype_Declaration
12475 Nkind (Type_Decl) = N_Loop_Statement
12477 Nkind (Type_Decl) = N_Task_Type_Declaration
12479 Nkind (Type_Decl) = N_Single_Task_Declaration
12481 Nkind (Type_Decl) = N_Protected_Type_Declaration
12483 Nkind (Type_Decl) = N_Single_Protected_Declaration)
12485 Type_Decl := Parent (Type_Decl);
12488 -- Why would Type_Decl not be present??? Without this test,
12489 -- short regression tests fail.
12491 if Present (Type_Decl) then
12493 -- Case of loop statement (more comments ???)
12495 if Nkind (Type_Decl) = N_Loop_Statement then
12497 Indic : Node_Id := Parent (R);
12500 while Present (Indic) and then not
12501 (Nkind (Indic) = N_Subtype_Indication)
12503 Indic := Parent (Indic);
12506 if Present (Indic) then
12507 Def_Id := Etype (Subtype_Mark (Indic));
12509 Insert_Range_Checks
12515 Do_Before => True);
12519 -- All other cases (more comments ???)
12522 Def_Id := Defining_Identifier (Type_Decl);
12524 if (Ekind (Def_Id) = E_Record_Type
12525 and then Depends_On_Discriminant (R))
12527 (Ekind (Def_Id) = E_Protected_Type
12528 and then Has_Discriminants (Def_Id))
12530 Append_Range_Checks
12531 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
12534 Insert_Range_Checks
12535 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
12543 elsif Expander_Active then
12544 Get_Index_Bounds (R, Lo, Hi);
12545 Force_Evaluation (Lo);
12546 Force_Evaluation (Hi);
12548 end Process_Range_Expr_In_Decl;
12550 --------------------------------------
12551 -- Process_Real_Range_Specification --
12552 --------------------------------------
12554 procedure Process_Real_Range_Specification (Def : Node_Id) is
12555 Spec : constant Node_Id := Real_Range_Specification (Def);
12558 Err : Boolean := False;
12560 procedure Analyze_Bound (N : Node_Id);
12561 -- Analyze and check one bound
12563 -------------------
12564 -- Analyze_Bound --
12565 -------------------
12567 procedure Analyze_Bound (N : Node_Id) is
12569 Analyze_And_Resolve (N, Any_Real);
12571 if not Is_OK_Static_Expression (N) then
12572 Flag_Non_Static_Expr
12573 ("bound in real type definition is not static!", N);
12578 -- Start of processing for Process_Real_Range_Specification
12581 if Present (Spec) then
12582 Lo := Low_Bound (Spec);
12583 Hi := High_Bound (Spec);
12584 Analyze_Bound (Lo);
12585 Analyze_Bound (Hi);
12587 -- If error, clear away junk range specification
12590 Set_Real_Range_Specification (Def, Empty);
12593 end Process_Real_Range_Specification;
12595 ---------------------
12596 -- Process_Subtype --
12597 ---------------------
12599 function Process_Subtype
12601 Related_Nod : Node_Id;
12602 Related_Id : Entity_Id := Empty;
12603 Suffix : Character := ' ') return Entity_Id
12606 Def_Id : Entity_Id;
12607 Full_View_Id : Entity_Id;
12608 Subtype_Mark_Id : Entity_Id;
12610 procedure Check_Incomplete (T : Entity_Id);
12611 -- Called to verify that an incomplete type is not used prematurely
12613 ----------------------
12614 -- Check_Incomplete --
12615 ----------------------
12617 procedure Check_Incomplete (T : Entity_Id) is
12619 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
12620 Error_Msg_N ("invalid use of type before its full declaration", T);
12622 end Check_Incomplete;
12624 -- Start of processing for Process_Subtype
12627 -- Case of no constraints present
12629 if Nkind (S) /= N_Subtype_Indication then
12632 Check_Incomplete (S);
12634 -- Ada 2005 (AI-231): Static check
12636 if Ada_Version >= Ada_05
12637 and then Present (Parent (S))
12638 and then Null_Exclusion_Present (Parent (S))
12639 and then Nkind (Parent (S)) /= N_Access_To_Object_Definition
12640 and then not Is_Access_Type (Entity (S))
12643 ("(Ada 2005) null-exclusion part requires an access type", S);
12647 -- Case of constraint present, so that we have an N_Subtype_Indication
12648 -- node (this node is created only if constraints are present).
12652 Find_Type (Subtype_Mark (S));
12654 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
12656 (Nkind (Parent (S)) = N_Subtype_Declaration
12658 Is_Itype (Defining_Identifier (Parent (S))))
12660 Check_Incomplete (Subtype_Mark (S));
12664 Subtype_Mark_Id := Entity (Subtype_Mark (S));
12666 -- Explicit subtype declaration case
12668 if Nkind (P) = N_Subtype_Declaration then
12669 Def_Id := Defining_Identifier (P);
12671 -- Explicit derived type definition case
12673 elsif Nkind (P) = N_Derived_Type_Definition then
12674 Def_Id := Defining_Identifier (Parent (P));
12676 -- Implicit case, the Def_Id must be created as an implicit type.
12677 -- The one exception arises in the case of concurrent types, array
12678 -- and access types, where other subsidiary implicit types may be
12679 -- created and must appear before the main implicit type. In these
12680 -- cases we leave Def_Id set to Empty as a signal that Create_Itype
12681 -- has not yet been called to create Def_Id.
12684 if Is_Array_Type (Subtype_Mark_Id)
12685 or else Is_Concurrent_Type (Subtype_Mark_Id)
12686 or else Is_Access_Type (Subtype_Mark_Id)
12690 -- For the other cases, we create a new unattached Itype,
12691 -- and set the indication to ensure it gets attached later.
12695 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12699 -- If the kind of constraint is invalid for this kind of type,
12700 -- then give an error, and then pretend no constraint was given.
12702 if not Is_Valid_Constraint_Kind
12703 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
12706 ("incorrect constraint for this kind of type", Constraint (S));
12708 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
12710 -- Make recursive call, having got rid of the bogus constraint
12712 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
12715 -- Remaining processing depends on type
12717 case Ekind (Subtype_Mark_Id) is
12718 when Access_Kind =>
12719 Constrain_Access (Def_Id, S, Related_Nod);
12722 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
12724 when Decimal_Fixed_Point_Kind =>
12725 Constrain_Decimal (Def_Id, S);
12727 when Enumeration_Kind =>
12728 Constrain_Enumeration (Def_Id, S);
12730 when Ordinary_Fixed_Point_Kind =>
12731 Constrain_Ordinary_Fixed (Def_Id, S);
12734 Constrain_Float (Def_Id, S);
12736 when Integer_Kind =>
12737 Constrain_Integer (Def_Id, S);
12739 when E_Record_Type |
12742 E_Incomplete_Type =>
12743 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
12745 when Private_Kind =>
12746 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
12747 Set_Private_Dependents (Def_Id, New_Elmt_List);
12749 -- In case of an invalid constraint prevent further processing
12750 -- since the type constructed is missing expected fields.
12752 if Etype (Def_Id) = Any_Type then
12756 -- If the full view is that of a task with discriminants,
12757 -- we must constrain both the concurrent type and its
12758 -- corresponding record type. Otherwise we will just propagate
12759 -- the constraint to the full view, if available.
12761 if Present (Full_View (Subtype_Mark_Id))
12762 and then Has_Discriminants (Subtype_Mark_Id)
12763 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
12766 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12768 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
12769 Constrain_Concurrent (Full_View_Id, S,
12770 Related_Nod, Related_Id, Suffix);
12771 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
12772 Set_Full_View (Def_Id, Full_View_Id);
12775 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
12778 when Concurrent_Kind =>
12779 Constrain_Concurrent (Def_Id, S,
12780 Related_Nod, Related_Id, Suffix);
12783 Error_Msg_N ("invalid subtype mark in subtype indication", S);
12786 -- Size and Convention are always inherited from the base type
12788 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
12789 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
12793 end Process_Subtype;
12795 -----------------------------
12796 -- Record_Type_Declaration --
12797 -----------------------------
12799 procedure Record_Type_Declaration
12804 Def : constant Node_Id := Type_Definition (N);
12806 Is_Tagged : Boolean;
12807 Tag_Comp : Entity_Id;
12810 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
12811 -- if it detected an error for declaration T. This arises in the case of
12812 -- private tagged types where the full view omits the word tagged.
12815 Tagged_Present (Def)
12816 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
12818 -- Records constitute a scope for the component declarations within.
12819 -- The scope is created prior to the processing of these declarations.
12820 -- Discriminants are processed first, so that they are visible when
12821 -- processing the other components. The Ekind of the record type itself
12822 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
12824 -- Enter record scope
12828 -- These flags must be initialized before calling Process_Discriminants
12829 -- because this routine makes use of them.
12831 Set_Is_Tagged_Type (T, Is_Tagged);
12832 Set_Is_Limited_Record (T, Limited_Present (Def));
12834 -- Type is abstract if full declaration carries keyword, or if
12835 -- previous partial view did.
12837 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
12839 Set_Ekind (T, E_Record_Type);
12841 Init_Size_Align (T);
12843 Set_Stored_Constraint (T, No_Elist);
12845 -- If an incomplete or private type declaration was already given for
12846 -- the type, then this scope already exists, and the discriminants have
12847 -- been declared within. We must verify that the full declaration
12848 -- matches the incomplete one.
12850 Check_Or_Process_Discriminants (N, T, Prev);
12852 Set_Is_Constrained (T, not Has_Discriminants (T));
12853 Set_Has_Delayed_Freeze (T, True);
12855 -- For tagged types add a manually analyzed component corresponding
12856 -- to the component _tag, the corresponding piece of tree will be
12857 -- expanded as part of the freezing actions if it is not a CPP_Class.
12861 -- Do not add the tag unless we are in expansion mode
12863 if Expander_Active then
12864 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
12865 Enter_Name (Tag_Comp);
12867 Set_Is_Tag (Tag_Comp);
12868 Set_Ekind (Tag_Comp, E_Component);
12869 Set_Etype (Tag_Comp, RTE (RE_Tag));
12870 Set_DT_Entry_Count (Tag_Comp, No_Uint);
12871 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
12872 Init_Component_Location (Tag_Comp);
12875 Make_Class_Wide_Type (T);
12876 Set_Primitive_Operations (T, New_Elmt_List);
12879 -- We must suppress range checks when processing the components
12880 -- of a record in the presence of discriminants, since we don't
12881 -- want spurious checks to be generated during their analysis, but
12882 -- must reset the Suppress_Range_Checks flags after having processed
12883 -- the record definition.
12885 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
12886 Set_Kill_Range_Checks (T, True);
12887 Record_Type_Definition (Def, Prev);
12888 Set_Kill_Range_Checks (T, False);
12890 Record_Type_Definition (Def, Prev);
12893 -- Exit from record scope
12896 end Record_Type_Declaration;
12898 ----------------------------
12899 -- Record_Type_Definition --
12900 ----------------------------
12902 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
12903 Component : Entity_Id;
12904 Ctrl_Components : Boolean := False;
12905 Final_Storage_Only : Boolean;
12909 if Ekind (Prev_T) = E_Incomplete_Type then
12910 T := Full_View (Prev_T);
12915 Final_Storage_Only := not Is_Controlled (T);
12917 -- If the component list of a record type is defined by the reserved
12918 -- word null and there is no discriminant part, then the record type has
12919 -- no components and all records of the type are null records (RM 3.7)
12920 -- This procedure is also called to process the extension part of a
12921 -- record extension, in which case the current scope may have inherited
12925 or else No (Component_List (Def))
12926 or else Null_Present (Component_List (Def))
12931 Analyze_Declarations (Component_Items (Component_List (Def)));
12933 if Present (Variant_Part (Component_List (Def))) then
12934 Analyze (Variant_Part (Component_List (Def)));
12938 -- After completing the semantic analysis of the record definition,
12939 -- record components, both new and inherited, are accessible. Set
12940 -- their kind accordingly.
12942 Component := First_Entity (Current_Scope);
12943 while Present (Component) loop
12944 if Ekind (Component) = E_Void then
12945 Set_Ekind (Component, E_Component);
12946 Init_Component_Location (Component);
12949 if Has_Task (Etype (Component)) then
12953 if Ekind (Component) /= E_Component then
12956 elsif Has_Controlled_Component (Etype (Component))
12957 or else (Chars (Component) /= Name_uParent
12958 and then Is_Controlled (Etype (Component)))
12960 Set_Has_Controlled_Component (T, True);
12961 Final_Storage_Only := Final_Storage_Only
12962 and then Finalize_Storage_Only (Etype (Component));
12963 Ctrl_Components := True;
12966 Next_Entity (Component);
12969 -- A type is Finalize_Storage_Only only if all its controlled
12970 -- components are so.
12972 if Ctrl_Components then
12973 Set_Finalize_Storage_Only (T, Final_Storage_Only);
12976 -- Place reference to end record on the proper entity, which may
12977 -- be a partial view.
12979 if Present (Def) then
12980 Process_End_Label (Def, 'e', Prev_T);
12982 end Record_Type_Definition;
12984 ------------------------
12985 -- Replace_Components --
12986 ------------------------
12988 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
12989 function Process (N : Node_Id) return Traverse_Result;
12995 function Process (N : Node_Id) return Traverse_Result is
12999 if Nkind (N) = N_Discriminant_Specification then
13000 Comp := First_Discriminant (Typ);
13002 while Present (Comp) loop
13003 if Chars (Comp) = Chars (Defining_Identifier (N)) then
13004 Set_Defining_Identifier (N, Comp);
13008 Next_Discriminant (Comp);
13011 elsif Nkind (N) = N_Component_Declaration then
13012 Comp := First_Component (Typ);
13014 while Present (Comp) loop
13015 if Chars (Comp) = Chars (Defining_Identifier (N)) then
13016 Set_Defining_Identifier (N, Comp);
13020 Next_Component (Comp);
13027 procedure Replace is new Traverse_Proc (Process);
13029 -- Start of processing for Replace_Components
13033 end Replace_Components;
13035 -------------------------------
13036 -- Set_Completion_Referenced --
13037 -------------------------------
13039 procedure Set_Completion_Referenced (E : Entity_Id) is
13041 -- If in main unit, mark entity that is a completion as referenced,
13042 -- warnings go on the partial view when needed.
13044 if In_Extended_Main_Source_Unit (E) then
13045 Set_Referenced (E);
13047 end Set_Completion_Referenced;
13049 ---------------------
13050 -- Set_Fixed_Range --
13051 ---------------------
13053 -- The range for fixed-point types is complicated by the fact that we
13054 -- do not know the exact end points at the time of the declaration. This
13055 -- is true for three reasons:
13057 -- A size clause may affect the fudging of the end-points
13058 -- A small clause may affect the values of the end-points
13059 -- We try to include the end-points if it does not affect the size
13061 -- This means that the actual end-points must be established at the point
13062 -- when the type is frozen. Meanwhile, we first narrow the range as
13063 -- permitted (so that it will fit if necessary in a small specified size),
13064 -- and then build a range subtree with these narrowed bounds.
13066 -- Set_Fixed_Range constructs the range from real literal values, and sets
13067 -- the range as the Scalar_Range of the given fixed-point type entity.
13069 -- The parent of this range is set to point to the entity so that it is
13070 -- properly hooked into the tree (unlike normal Scalar_Range entries for
13071 -- other scalar types, which are just pointers to the range in the
13072 -- original tree, this would otherwise be an orphan).
13074 -- The tree is left unanalyzed. When the type is frozen, the processing
13075 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
13076 -- analyzed, and uses this as an indication that it should complete
13077 -- work on the range (it will know the final small and size values).
13079 procedure Set_Fixed_Range
13085 S : constant Node_Id :=
13087 Low_Bound => Make_Real_Literal (Loc, Lo),
13088 High_Bound => Make_Real_Literal (Loc, Hi));
13091 Set_Scalar_Range (E, S);
13093 end Set_Fixed_Range;
13095 ----------------------------------
13096 -- Set_Scalar_Range_For_Subtype --
13097 ----------------------------------
13099 procedure Set_Scalar_Range_For_Subtype
13100 (Def_Id : Entity_Id;
13104 Kind : constant Entity_Kind := Ekind (Def_Id);
13107 Set_Scalar_Range (Def_Id, R);
13109 -- We need to link the range into the tree before resolving it so
13110 -- that types that are referenced, including importantly the subtype
13111 -- itself, are properly frozen (Freeze_Expression requires that the
13112 -- expression be properly linked into the tree). Of course if it is
13113 -- already linked in, then we do not disturb the current link.
13115 if No (Parent (R)) then
13116 Set_Parent (R, Def_Id);
13119 -- Reset the kind of the subtype during analysis of the range, to
13120 -- catch possible premature use in the bounds themselves.
13122 Set_Ekind (Def_Id, E_Void);
13123 Process_Range_Expr_In_Decl (R, Subt);
13124 Set_Ekind (Def_Id, Kind);
13126 end Set_Scalar_Range_For_Subtype;
13128 --------------------------------------------------------
13129 -- Set_Stored_Constraint_From_Discriminant_Constraint --
13130 --------------------------------------------------------
13132 procedure Set_Stored_Constraint_From_Discriminant_Constraint
13136 -- Make sure set if encountered during Expand_To_Stored_Constraint
13138 Set_Stored_Constraint (E, No_Elist);
13140 -- Give it the right value
13142 if Is_Constrained (E) and then Has_Discriminants (E) then
13143 Set_Stored_Constraint (E,
13144 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
13146 end Set_Stored_Constraint_From_Discriminant_Constraint;
13148 -------------------------------------
13149 -- Signed_Integer_Type_Declaration --
13150 -------------------------------------
13152 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
13153 Implicit_Base : Entity_Id;
13154 Base_Typ : Entity_Id;
13157 Errs : Boolean := False;
13161 function Can_Derive_From (E : Entity_Id) return Boolean;
13162 -- Determine whether given bounds allow derivation from specified type
13164 procedure Check_Bound (Expr : Node_Id);
13165 -- Check bound to make sure it is integral and static. If not, post
13166 -- appropriate error message and set Errs flag
13168 ---------------------
13169 -- Can_Derive_From --
13170 ---------------------
13172 -- Note we check both bounds against both end values, to deal with
13173 -- strange types like ones with a range of 0 .. -12341234.
13175 function Can_Derive_From (E : Entity_Id) return Boolean is
13176 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
13177 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
13179 return Lo <= Lo_Val and then Lo_Val <= Hi
13181 Lo <= Hi_Val and then Hi_Val <= Hi;
13182 end Can_Derive_From;
13188 procedure Check_Bound (Expr : Node_Id) is
13190 -- If a range constraint is used as an integer type definition, each
13191 -- bound of the range must be defined by a static expression of some
13192 -- integer type, but the two bounds need not have the same integer
13193 -- type (Negative bounds are allowed.) (RM 3.5.4)
13195 if not Is_Integer_Type (Etype (Expr)) then
13197 ("integer type definition bounds must be of integer type", Expr);
13200 elsif not Is_OK_Static_Expression (Expr) then
13201 Flag_Non_Static_Expr
13202 ("non-static expression used for integer type bound!", Expr);
13205 -- The bounds are folded into literals, and we set their type to be
13206 -- universal, to avoid typing difficulties: we cannot set the type
13207 -- of the literal to the new type, because this would be a forward
13208 -- reference for the back end, and if the original type is user-
13209 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
13212 if Is_Entity_Name (Expr) then
13213 Fold_Uint (Expr, Expr_Value (Expr), True);
13216 Set_Etype (Expr, Universal_Integer);
13220 -- Start of processing for Signed_Integer_Type_Declaration
13223 -- Create an anonymous base type
13226 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
13228 -- Analyze and check the bounds, they can be of any integer type
13230 Lo := Low_Bound (Def);
13231 Hi := High_Bound (Def);
13233 -- Arbitrarily use Integer as the type if either bound had an error
13235 if Hi = Error or else Lo = Error then
13236 Base_Typ := Any_Integer;
13237 Set_Error_Posted (T, True);
13239 -- Here both bounds are OK expressions
13242 Analyze_And_Resolve (Lo, Any_Integer);
13243 Analyze_And_Resolve (Hi, Any_Integer);
13249 Hi := Type_High_Bound (Standard_Long_Long_Integer);
13250 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
13253 -- Find type to derive from
13255 Lo_Val := Expr_Value (Lo);
13256 Hi_Val := Expr_Value (Hi);
13258 if Can_Derive_From (Standard_Short_Short_Integer) then
13259 Base_Typ := Base_Type (Standard_Short_Short_Integer);
13261 elsif Can_Derive_From (Standard_Short_Integer) then
13262 Base_Typ := Base_Type (Standard_Short_Integer);
13264 elsif Can_Derive_From (Standard_Integer) then
13265 Base_Typ := Base_Type (Standard_Integer);
13267 elsif Can_Derive_From (Standard_Long_Integer) then
13268 Base_Typ := Base_Type (Standard_Long_Integer);
13270 elsif Can_Derive_From (Standard_Long_Long_Integer) then
13271 Base_Typ := Base_Type (Standard_Long_Long_Integer);
13274 Base_Typ := Base_Type (Standard_Long_Long_Integer);
13275 Error_Msg_N ("integer type definition bounds out of range", Def);
13276 Hi := Type_High_Bound (Standard_Long_Long_Integer);
13277 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
13281 -- Complete both implicit base and declared first subtype entities
13283 Set_Etype (Implicit_Base, Base_Typ);
13284 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
13285 Set_Size_Info (Implicit_Base, (Base_Typ));
13286 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
13287 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
13289 Set_Ekind (T, E_Signed_Integer_Subtype);
13290 Set_Etype (T, Implicit_Base);
13292 Set_Size_Info (T, (Implicit_Base));
13293 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
13294 Set_Scalar_Range (T, Def);
13295 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
13296 Set_Is_Constrained (T);
13297 end Signed_Integer_Type_Declaration;