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
405 -- value of Empty for Def_Id indicates that an implicit type must be
406 -- created, but creation is delayed (and must be done by this procedure)
407 -- because other subsidiary implicit types must be created first (which
408 -- is why 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.
456 -- The constraint can be a subtype name, or a range with or without
457 -- an 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
736 -- the case of a subprogram, If the designated type is incomplete,
737 -- the operation will be a primitive operation of the full type, to
738 -- be updated subsequently. If the type is imported through a limited
739 -- with clause, it is not a primitive operation of the type (which
740 -- is declared 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
787 -- have parent pointers. So we set it and then unset it ???
788 -- If and when Itypes have proper parent pointers to their
789 -- declarations, this 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
805 if Ekind (Formal) /= E_In_Parameter
806 and then Nkind (T_Def) = N_Access_Function_Definition
808 Error_Msg_N ("functions can only have IN parameters", Formal);
811 if Ekind (Etype (Formal)) = E_Incomplete_Type then
812 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
813 Set_Has_Delayed_Freeze (Desig_Type);
816 Next_Formal (Formal);
820 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
821 and then not Has_Delayed_Freeze (Desig_Type)
823 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
824 Set_Has_Delayed_Freeze (Desig_Type);
827 Check_Delayed_Subprogram (Desig_Type);
829 if Protected_Present (T_Def) then
830 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
831 Set_Convention (Desig_Type, Convention_Protected);
833 Set_Ekind (T_Name, E_Access_Subprogram_Type);
836 Set_Etype (T_Name, T_Name);
837 Init_Size_Align (T_Name);
838 Set_Directly_Designated_Type (T_Name, Desig_Type);
840 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
842 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
844 Check_Restriction (No_Access_Subprograms, T_Def);
845 end Access_Subprogram_Declaration;
847 ----------------------------
848 -- Access_Type_Declaration --
849 ----------------------------
851 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
852 S : constant Node_Id := Subtype_Indication (Def);
853 P : constant Node_Id := Parent (Def);
859 -- Check for permissible use of incomplete type
861 if Nkind (S) /= N_Subtype_Indication then
864 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
865 Set_Directly_Designated_Type (T, Entity (S));
867 Set_Directly_Designated_Type (T,
868 Process_Subtype (S, P, T, 'P'));
872 Set_Directly_Designated_Type (T,
873 Process_Subtype (S, P, T, 'P'));
876 if All_Present (Def) or Constant_Present (Def) then
877 Set_Ekind (T, E_General_Access_Type);
879 Set_Ekind (T, E_Access_Type);
882 if Base_Type (Designated_Type (T)) = T then
883 Error_Msg_N ("access type cannot designate itself", S);
888 -- If the type has appeared already in a with_type clause, it is
889 -- frozen and the pointer size is already set. Else, initialize.
891 if not From_With_Type (T) then
895 Set_Is_Access_Constant (T, Constant_Present (Def));
897 Desig := Designated_Type (T);
899 -- If designated type is an imported tagged type, indicate that the
900 -- access type is also imported, and therefore restricted in its use.
901 -- The access type may already be imported, so keep setting otherwise.
903 -- Ada 2005 (AI-50217): If the non-limited view of the designated type
904 -- is available, use it as the designated type of the access type, so
905 -- that the back-end gets a usable entity.
911 if From_With_Type (Desig) then
912 Set_From_With_Type (T);
914 if Ekind (Desig) = E_Incomplete_Type then
915 N_Desig := Non_Limited_View (Desig);
917 else pragma Assert (Ekind (Desig) = E_Class_Wide_Type);
918 if From_With_Type (Etype (Desig)) then
919 N_Desig := Non_Limited_View (Etype (Desig));
921 N_Desig := Etype (Desig);
925 pragma Assert (Present (N_Desig));
926 Set_Directly_Designated_Type (T, N_Desig);
930 -- Note that Has_Task is always false, since the access type itself
931 -- is not a task type. See Einfo for more description on this point.
932 -- Exactly the same consideration applies to Has_Controlled_Component.
934 Set_Has_Task (T, False);
935 Set_Has_Controlled_Component (T, False);
937 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
940 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
941 Set_Is_Access_Constant (T, Constant_Present (Def));
942 end Access_Type_Declaration;
944 -----------------------------------
945 -- Analyze_Component_Declaration --
946 -----------------------------------
948 procedure Analyze_Component_Declaration (N : Node_Id) is
949 Id : constant Entity_Id := Defining_Identifier (N);
954 Generate_Definition (Id);
957 if Present (Subtype_Indication (Component_Definition (N))) then
958 T := Find_Type_Of_Object
959 (Subtype_Indication (Component_Definition (N)), N);
961 -- Ada 2005 (AI-230): Access Definition case
964 pragma Assert (Present
965 (Access_Definition (Component_Definition (N))));
967 T := Access_Definition
969 N => Access_Definition (Component_Definition (N)));
971 -- Ada 2005 (AI-230): In case of components that are anonymous
972 -- access types the level of accessibility depends on the enclosing
975 Set_Scope (T, Current_Scope); -- Ada 2005 (AI-230)
979 if Present (Access_To_Subprogram_Definition
980 (Access_Definition (Component_Definition (N))))
981 and then Protected_Present (Access_To_Subprogram_Definition
983 (Component_Definition (N))))
985 T := Replace_Anonymous_Access_To_Protected_Subprogram (N, T);
989 -- If the subtype is a constrained subtype of the enclosing record,
990 -- (which must have a partial view) the back-end does not handle
991 -- properly the recursion. Rewrite the component declaration with
992 -- an explicit subtype indication, which is acceptable to Gigi. We
993 -- can copy the tree directly because side effects have already been
994 -- removed from discriminant constraints.
996 if Ekind (T) = E_Access_Subtype
997 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
998 and then Comes_From_Source (T)
999 and then Nkind (Parent (T)) = N_Subtype_Declaration
1000 and then Etype (Directly_Designated_Type (T)) = Current_Scope
1003 (Subtype_Indication (Component_Definition (N)),
1004 New_Copy_Tree (Subtype_Indication (Parent (T))));
1005 T := Find_Type_Of_Object
1006 (Subtype_Indication (Component_Definition (N)), N);
1009 -- If the component declaration includes a default expression, then we
1010 -- check that the component is not of a limited type (RM 3.7(5)),
1011 -- and do the special preanalysis of the expression (see section on
1012 -- "Handling of Default and Per-Object Expressions" in the spec of
1015 if Present (Expression (N)) then
1016 Analyze_Per_Use_Expression (Expression (N), T);
1017 Check_Initialization (T, Expression (N));
1020 -- The parent type may be a private view with unknown discriminants,
1021 -- and thus unconstrained. Regular components must be constrained.
1023 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
1024 if Is_Class_Wide_Type (T) then
1026 ("class-wide subtype with unknown discriminants" &
1027 " in component declaration",
1028 Subtype_Indication (Component_Definition (N)));
1031 ("unconstrained subtype in component declaration",
1032 Subtype_Indication (Component_Definition (N)));
1035 -- Components cannot be abstract, except for the special case of
1036 -- the _Parent field (case of extending an abstract tagged type)
1038 elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then
1039 Error_Msg_N ("type of a component cannot be abstract", N);
1043 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
1045 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
1046 -- out some static checks
1048 if Ada_Version >= Ada_05
1049 and then (Null_Exclusion_Present (Component_Definition (N))
1050 or else Can_Never_Be_Null (T))
1052 Set_Can_Never_Be_Null (Id);
1053 Null_Exclusion_Static_Checks (N);
1056 -- If this component is private (or depends on a private type),
1057 -- flag the record type to indicate that some operations are not
1060 P := Private_Component (T);
1063 -- Check for circular definitions.
1065 if P = Any_Type then
1066 Set_Etype (Id, Any_Type);
1068 -- There is a gap in the visibility of operations only if the
1069 -- component type is not defined in the scope of the record type.
1071 elsif Scope (P) = Scope (Current_Scope) then
1074 elsif Is_Limited_Type (P) then
1075 Set_Is_Limited_Composite (Current_Scope);
1078 Set_Is_Private_Composite (Current_Scope);
1083 and then Is_Limited_Type (T)
1084 and then Chars (Id) /= Name_uParent
1085 and then Is_Tagged_Type (Current_Scope)
1087 if Is_Derived_Type (Current_Scope)
1088 and then not Is_Limited_Record (Root_Type (Current_Scope))
1091 ("extension of nonlimited type cannot have limited components",
1093 Explain_Limited_Type (T, N);
1094 Set_Etype (Id, Any_Type);
1095 Set_Is_Limited_Composite (Current_Scope, False);
1097 elsif not Is_Derived_Type (Current_Scope)
1098 and then not Is_Limited_Record (Current_Scope)
1101 ("nonlimited tagged type cannot have limited components", N);
1102 Explain_Limited_Type (T, N);
1103 Set_Etype (Id, Any_Type);
1104 Set_Is_Limited_Composite (Current_Scope, False);
1108 Set_Original_Record_Component (Id, Id);
1109 end Analyze_Component_Declaration;
1111 --------------------------
1112 -- Analyze_Declarations --
1113 --------------------------
1115 procedure Analyze_Declarations (L : List_Id) is
1117 Next_Node : Node_Id;
1118 Freeze_From : Entity_Id := Empty;
1121 -- Adjust D not to include implicit label declarations, since these
1122 -- have strange Sloc values that result in elaboration check problems.
1123 -- (They have the sloc of the label as found in the source, and that
1124 -- is ahead of the current declarative part).
1130 procedure Adjust_D is
1132 while Present (Prev (D))
1133 and then Nkind (D) = N_Implicit_Label_Declaration
1139 -- Start of processing for Analyze_Declarations
1143 while Present (D) loop
1145 -- Complete analysis of declaration
1148 Next_Node := Next (D);
1150 if No (Freeze_From) then
1151 Freeze_From := First_Entity (Current_Scope);
1154 -- At the end of a declarative part, freeze remaining entities
1155 -- declared in it. The end of the visible declarations of a
1156 -- package specification is not the end of a declarative part
1157 -- if private declarations are present. The end of a package
1158 -- declaration is a freezing point only if it a library package.
1159 -- A task definition or protected type definition is not a freeze
1160 -- point either. Finally, we do not freeze entities in generic
1161 -- scopes, because there is no code generated for them and freeze
1162 -- nodes will be generated for the instance.
1164 -- The end of a package instantiation is not a freeze point, but
1165 -- for now we make it one, because the generic body is inserted
1166 -- (currently) immediately after. Generic instantiations will not
1167 -- be a freeze point once delayed freezing of bodies is implemented.
1168 -- (This is needed in any case for early instantiations ???).
1170 if No (Next_Node) then
1171 if Nkind (Parent (L)) = N_Component_List
1172 or else Nkind (Parent (L)) = N_Task_Definition
1173 or else Nkind (Parent (L)) = N_Protected_Definition
1177 elsif Nkind (Parent (L)) /= N_Package_Specification then
1178 if Nkind (Parent (L)) = N_Package_Body then
1179 Freeze_From := First_Entity (Current_Scope);
1183 Freeze_All (Freeze_From, D);
1184 Freeze_From := Last_Entity (Current_Scope);
1186 elsif Scope (Current_Scope) /= Standard_Standard
1187 and then not Is_Child_Unit (Current_Scope)
1188 and then No (Generic_Parent (Parent (L)))
1192 elsif L /= Visible_Declarations (Parent (L))
1193 or else No (Private_Declarations (Parent (L)))
1194 or else Is_Empty_List (Private_Declarations (Parent (L)))
1197 Freeze_All (Freeze_From, D);
1198 Freeze_From := Last_Entity (Current_Scope);
1201 -- If next node is a body then freeze all types before the body.
1202 -- An exception occurs for expander generated bodies, which can
1203 -- be recognized by their already being analyzed. The expander
1204 -- ensures that all types needed by these bodies have been frozen
1205 -- but it is not necessary to freeze all types (and would be wrong
1206 -- since it would not correspond to an RM defined freeze point).
1208 elsif not Analyzed (Next_Node)
1209 and then (Nkind (Next_Node) = N_Subprogram_Body
1210 or else Nkind (Next_Node) = N_Entry_Body
1211 or else Nkind (Next_Node) = N_Package_Body
1212 or else Nkind (Next_Node) = N_Protected_Body
1213 or else Nkind (Next_Node) = N_Task_Body
1214 or else Nkind (Next_Node) in N_Body_Stub)
1217 Freeze_All (Freeze_From, D);
1218 Freeze_From := Last_Entity (Current_Scope);
1223 end Analyze_Declarations;
1225 ----------------------------------
1226 -- Analyze_Incomplete_Type_Decl --
1227 ----------------------------------
1229 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
1230 F : constant Boolean := Is_Pure (Current_Scope);
1234 Generate_Definition (Defining_Identifier (N));
1236 -- Process an incomplete declaration. The identifier must not have been
1237 -- declared already in the scope. However, an incomplete declaration may
1238 -- appear in the private part of a package, for a private type that has
1239 -- already been declared.
1241 -- In this case, the discriminants (if any) must match.
1243 T := Find_Type_Name (N);
1245 Set_Ekind (T, E_Incomplete_Type);
1246 Init_Size_Align (T);
1247 Set_Is_First_Subtype (T, True);
1251 Set_Stored_Constraint (T, No_Elist);
1253 if Present (Discriminant_Specifications (N)) then
1254 Process_Discriminants (N);
1259 -- If the type has discriminants, non-trivial subtypes may be
1260 -- be declared before the full view of the type. The full views
1261 -- of those subtypes will be built after the full view of the type.
1263 Set_Private_Dependents (T, New_Elmt_List);
1265 end Analyze_Incomplete_Type_Decl;
1267 -----------------------------
1268 -- Analyze_Itype_Reference --
1269 -----------------------------
1271 -- Nothing to do. This node is placed in the tree only for the benefit
1272 -- of Gigi processing, and has no effect on the semantic processing.
1274 procedure Analyze_Itype_Reference (N : Node_Id) is
1276 pragma Assert (Is_Itype (Itype (N)));
1278 end Analyze_Itype_Reference;
1280 --------------------------------
1281 -- Analyze_Number_Declaration --
1282 --------------------------------
1284 procedure Analyze_Number_Declaration (N : Node_Id) is
1285 Id : constant Entity_Id := Defining_Identifier (N);
1286 E : constant Node_Id := Expression (N);
1288 Index : Interp_Index;
1292 Generate_Definition (Id);
1295 -- This is an optimization of a common case of an integer literal
1297 if Nkind (E) = N_Integer_Literal then
1298 Set_Is_Static_Expression (E, True);
1299 Set_Etype (E, Universal_Integer);
1301 Set_Etype (Id, Universal_Integer);
1302 Set_Ekind (Id, E_Named_Integer);
1303 Set_Is_Frozen (Id, True);
1307 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1309 -- Process expression, replacing error by integer zero, to avoid
1310 -- cascaded errors or aborts further along in the processing
1312 -- Replace Error by integer zero, which seems least likely to
1313 -- cause cascaded errors.
1316 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
1317 Set_Error_Posted (E);
1322 -- Verify that the expression is static and numeric. If
1323 -- the expression is overloaded, we apply the preference
1324 -- rule that favors root numeric types.
1326 if not Is_Overloaded (E) then
1331 Get_First_Interp (E, Index, It);
1333 while Present (It.Typ) loop
1334 if (Is_Integer_Type (It.Typ)
1335 or else Is_Real_Type (It.Typ))
1336 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
1338 if T = Any_Type then
1341 elsif It.Typ = Universal_Real
1342 or else It.Typ = Universal_Integer
1344 -- Choose universal interpretation over any other.
1351 Get_Next_Interp (Index, It);
1355 if Is_Integer_Type (T) then
1357 Set_Etype (Id, Universal_Integer);
1358 Set_Ekind (Id, E_Named_Integer);
1360 elsif Is_Real_Type (T) then
1362 -- Because the real value is converted to universal_real, this
1363 -- is a legal context for a universal fixed expression.
1365 if T = Universal_Fixed then
1367 Loc : constant Source_Ptr := Sloc (N);
1368 Conv : constant Node_Id := Make_Type_Conversion (Loc,
1370 New_Occurrence_Of (Universal_Real, Loc),
1371 Expression => Relocate_Node (E));
1378 elsif T = Any_Fixed then
1379 Error_Msg_N ("illegal context for mixed mode operation", E);
1381 -- Expression is of the form : universal_fixed * integer.
1382 -- Try to resolve as universal_real.
1384 T := Universal_Real;
1389 Set_Etype (Id, Universal_Real);
1390 Set_Ekind (Id, E_Named_Real);
1393 Wrong_Type (E, Any_Numeric);
1397 Set_Ekind (Id, E_Constant);
1398 Set_Never_Set_In_Source (Id, True);
1399 Set_Is_True_Constant (Id, True);
1403 if Nkind (E) = N_Integer_Literal
1404 or else Nkind (E) = N_Real_Literal
1406 Set_Etype (E, Etype (Id));
1409 if not Is_OK_Static_Expression (E) then
1410 Flag_Non_Static_Expr
1411 ("non-static expression used in number declaration!", E);
1412 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
1413 Set_Etype (E, Any_Type);
1415 end Analyze_Number_Declaration;
1417 --------------------------------
1418 -- Analyze_Object_Declaration --
1419 --------------------------------
1421 procedure Analyze_Object_Declaration (N : Node_Id) is
1422 Loc : constant Source_Ptr := Sloc (N);
1423 Id : constant Entity_Id := Defining_Identifier (N);
1427 E : Node_Id := Expression (N);
1428 -- E is set to Expression (N) throughout this routine. When
1429 -- Expression (N) is modified, E is changed accordingly.
1431 Prev_Entity : Entity_Id := Empty;
1433 function Build_Default_Subtype return Entity_Id;
1434 -- If the object is limited or aliased, and if the type is unconstrained
1435 -- and there is no expression, the discriminants cannot be modified and
1436 -- the subtype of the object is constrained by the defaults, so it is
1437 -- worthile building the corresponding subtype.
1439 function Count_Tasks (T : Entity_Id) return Uint;
1440 -- This function is called when a library level object of type T
1441 -- is declared. It's function is to count the static number of
1442 -- tasks declared within the type (it is only called if Has_Tasks
1443 -- is set for T). As a side effect, if an array of tasks with
1444 -- non-static bounds or a variant record type is encountered,
1445 -- Check_Restrictions is called indicating the count is unknown.
1447 ---------------------------
1448 -- Build_Default_Subtype --
1449 ---------------------------
1451 function Build_Default_Subtype return Entity_Id is
1452 Constraints : constant List_Id := New_List;
1458 Disc := First_Discriminant (T);
1460 if No (Discriminant_Default_Value (Disc)) then
1461 return T; -- previous error.
1464 Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
1465 while Present (Disc) loop
1468 Discriminant_Default_Value (Disc)), Constraints);
1469 Next_Discriminant (Disc);
1473 Make_Subtype_Declaration (Loc,
1474 Defining_Identifier => Act,
1475 Subtype_Indication =>
1476 Make_Subtype_Indication (Loc,
1477 Subtype_Mark => New_Occurrence_Of (T, Loc),
1479 Make_Index_Or_Discriminant_Constraint
1480 (Loc, Constraints)));
1482 Insert_Before (N, Decl);
1485 end Build_Default_Subtype;
1491 function Count_Tasks (T : Entity_Id) return Uint is
1497 if Is_Task_Type (T) then
1500 elsif Is_Record_Type (T) then
1501 if Has_Discriminants (T) then
1502 Check_Restriction (Max_Tasks, N);
1507 C := First_Component (T);
1508 while Present (C) loop
1509 V := V + Count_Tasks (Etype (C));
1516 elsif Is_Array_Type (T) then
1517 X := First_Index (T);
1518 V := Count_Tasks (Component_Type (T));
1519 while Present (X) loop
1522 if not Is_Static_Subtype (C) then
1523 Check_Restriction (Max_Tasks, N);
1526 V := V * (UI_Max (Uint_0,
1527 Expr_Value (Type_High_Bound (C)) -
1528 Expr_Value (Type_Low_Bound (C)) + Uint_1));
1541 -- Start of processing for Analyze_Object_Declaration
1544 -- There are three kinds of implicit types generated by an
1545 -- object declaration:
1547 -- 1. Those for generated by the original Object Definition
1549 -- 2. Those generated by the Expression
1551 -- 3. Those used to constrained the Object Definition with the
1552 -- expression constraints when it is unconstrained
1554 -- They must be generated in this order to avoid order of elaboration
1555 -- issues. Thus the first step (after entering the name) is to analyze
1556 -- the object definition.
1558 if Constant_Present (N) then
1559 Prev_Entity := Current_Entity_In_Scope (Id);
1561 -- If homograph is an implicit subprogram, it is overridden by the
1562 -- current declaration.
1564 if Present (Prev_Entity)
1565 and then Is_Overloadable (Prev_Entity)
1566 and then Is_Inherited_Operation (Prev_Entity)
1568 Prev_Entity := Empty;
1572 if Present (Prev_Entity) then
1573 Constant_Redeclaration (Id, N, T);
1575 Generate_Reference (Prev_Entity, Id, 'c');
1576 Set_Completion_Referenced (Id);
1578 if Error_Posted (N) then
1579 -- Type mismatch or illegal redeclaration, Do not analyze
1580 -- expression to avoid cascaded errors.
1582 T := Find_Type_Of_Object (Object_Definition (N), N);
1584 Set_Ekind (Id, E_Variable);
1588 -- In the normal case, enter identifier at the start to catch
1589 -- premature usage in the initialization expression.
1592 Generate_Definition (Id);
1595 T := Find_Type_Of_Object (Object_Definition (N), N);
1597 if Error_Posted (Id) then
1599 Set_Ekind (Id, E_Variable);
1604 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
1605 -- out some static checks
1607 if Ada_Version >= Ada_05
1608 and then (Null_Exclusion_Present (N)
1609 or else Can_Never_Be_Null (T))
1611 Set_Can_Never_Be_Null (Id);
1612 Null_Exclusion_Static_Checks (N);
1615 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1617 -- If deferred constant, make sure context is appropriate. We detect
1618 -- a deferred constant as a constant declaration with no expression.
1619 -- A deferred constant can appear in a package body if its completion
1620 -- is by means of an interface pragma.
1622 if Constant_Present (N)
1625 if not Is_Package (Current_Scope) then
1627 ("invalid context for deferred constant declaration ('R'M 7.4)",
1630 ("\declaration requires an initialization expression",
1632 Set_Constant_Present (N, False);
1634 -- In Ada 83, deferred constant must be of private type
1636 elsif not Is_Private_Type (T) then
1637 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1639 ("(Ada 83) deferred constant must be private type", N);
1643 -- If not a deferred constant, then object declaration freezes its type
1646 Check_Fully_Declared (T, N);
1647 Freeze_Before (N, T);
1650 -- If the object was created by a constrained array definition, then
1651 -- set the link in both the anonymous base type and anonymous subtype
1652 -- that are built to represent the array type to point to the object.
1654 if Nkind (Object_Definition (Declaration_Node (Id))) =
1655 N_Constrained_Array_Definition
1657 Set_Related_Array_Object (T, Id);
1658 Set_Related_Array_Object (Base_Type (T), Id);
1661 -- Special checks for protected objects not at library level
1663 if Is_Protected_Type (T)
1664 and then not Is_Library_Level_Entity (Id)
1666 Check_Restriction (No_Local_Protected_Objects, Id);
1668 -- Protected objects with interrupt handlers must be at library level
1670 if Has_Interrupt_Handler (T) then
1672 ("interrupt object can only be declared at library level", Id);
1676 -- The actual subtype of the object is the nominal subtype, unless
1677 -- the nominal one is unconstrained and obtained from the expression.
1681 -- Process initialization expression if present and not in error
1683 if Present (E) and then E /= Error then
1686 -- In case of errors detected in the analysis of the expression,
1687 -- decorate it with the expected type to avoid cascade errors
1689 if not Present (Etype (E)) then
1693 -- If an initialization expression is present, then we set the
1694 -- Is_True_Constant flag. It will be reset if this is a variable
1695 -- and it is indeed modified.
1697 Set_Is_True_Constant (Id, True);
1699 -- If we are analyzing a constant declaration, set its completion
1700 -- flag after analyzing the expression.
1702 if Constant_Present (N) then
1703 Set_Has_Completion (Id);
1706 if not Assignment_OK (N) then
1707 Check_Initialization (T, E);
1710 Set_Etype (Id, T); -- may be overridden later on.
1712 Check_Unset_Reference (E);
1714 if Compile_Time_Known_Value (E) then
1715 Set_Current_Value (Id, E);
1718 -- Check incorrect use of dynamically tagged expressions. Note
1719 -- the use of Is_Tagged_Type (T) which seems redundant but is in
1720 -- fact important to avoid spurious errors due to expanded code
1721 -- for dispatching functions over an anonymous access type
1723 if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
1724 and then Is_Tagged_Type (T)
1725 and then not Is_Class_Wide_Type (T)
1727 Error_Msg_N ("dynamically tagged expression not allowed!", E);
1730 Apply_Scalar_Range_Check (E, T);
1731 Apply_Static_Length_Check (E, T);
1734 -- Abstract type is never permitted for a variable or constant.
1735 -- Note: we inhibit this check for objects that do not come from
1736 -- source because there is at least one case (the expansion of
1737 -- x'class'input where x is abstract) where we legitimately
1738 -- generate an abstract object.
1740 if Is_Abstract (T) and then Comes_From_Source (N) then
1741 Error_Msg_N ("type of object cannot be abstract",
1742 Object_Definition (N));
1743 if Is_CPP_Class (T) then
1744 Error_Msg_NE ("\} may need a cpp_constructor",
1745 Object_Definition (N), T);
1748 -- Case of unconstrained type
1750 elsif Is_Indefinite_Subtype (T) then
1752 -- Nothing to do in deferred constant case
1754 if Constant_Present (N) and then No (E) then
1757 -- Case of no initialization present
1760 if No_Initialization (N) then
1763 elsif Is_Class_Wide_Type (T) then
1765 ("initialization required in class-wide declaration ", N);
1769 ("unconstrained subtype not allowed (need initialization)",
1770 Object_Definition (N));
1773 -- Case of initialization present but in error. Set initial
1774 -- expression as absent (but do not make above complaints)
1776 elsif E = Error then
1777 Set_Expression (N, Empty);
1780 -- Case of initialization present
1783 -- Not allowed in Ada 83
1785 if not Constant_Present (N) then
1786 if Ada_Version = Ada_83
1787 and then Comes_From_Source (Object_Definition (N))
1790 ("(Ada 83) unconstrained variable not allowed",
1791 Object_Definition (N));
1795 -- Now we constrain the variable from the initializing expression
1797 -- If the expression is an aggregate, it has been expanded into
1798 -- individual assignments. Retrieve the actual type from the
1799 -- expanded construct.
1801 if Is_Array_Type (T)
1802 and then No_Initialization (N)
1803 and then Nkind (Original_Node (E)) = N_Aggregate
1808 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
1809 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
1812 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
1814 if Aliased_Present (N) then
1815 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1818 Freeze_Before (N, Act_T);
1819 Freeze_Before (N, T);
1822 elsif Is_Array_Type (T)
1823 and then No_Initialization (N)
1824 and then Nkind (Original_Node (E)) = N_Aggregate
1826 if not Is_Entity_Name (Object_Definition (N)) then
1828 Check_Compile_Time_Size (Act_T);
1830 if Aliased_Present (N) then
1831 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1835 -- When the given object definition and the aggregate are specified
1836 -- independently, and their lengths might differ do a length check.
1837 -- This cannot happen if the aggregate is of the form (others =>...)
1839 if not Is_Constrained (T) then
1842 elsif Nkind (E) = N_Raise_Constraint_Error then
1844 -- Aggregate is statically illegal. Place back in declaration
1846 Set_Expression (N, E);
1847 Set_No_Initialization (N, False);
1849 elsif T = Etype (E) then
1852 elsif Nkind (E) = N_Aggregate
1853 and then Present (Component_Associations (E))
1854 and then Present (Choices (First (Component_Associations (E))))
1855 and then Nkind (First
1856 (Choices (First (Component_Associations (E))))) = N_Others_Choice
1861 Apply_Length_Check (E, T);
1864 elsif (Is_Limited_Record (T)
1865 or else Is_Concurrent_Type (T))
1866 and then not Is_Constrained (T)
1867 and then Has_Discriminants (T)
1869 Act_T := Build_Default_Subtype;
1870 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
1872 elsif not Is_Constrained (T)
1873 and then Has_Discriminants (T)
1874 and then Constant_Present (N)
1875 and then Nkind (E) = N_Function_Call
1877 -- The back-end has problems with constants of a discriminated type
1878 -- with defaults, if the initial value is a function call. We
1879 -- generate an intermediate temporary for the result of the call.
1880 -- It is unclear why this should make it acceptable to gcc. ???
1882 Remove_Side_Effects (E);
1885 if T = Standard_Wide_Character
1886 or else Root_Type (T) = Standard_Wide_String
1888 Check_Restriction (No_Wide_Characters, Object_Definition (N));
1891 -- Now establish the proper kind and type of the object
1893 if Constant_Present (N) then
1894 Set_Ekind (Id, E_Constant);
1895 Set_Never_Set_In_Source (Id, True);
1896 Set_Is_True_Constant (Id, True);
1899 Set_Ekind (Id, E_Variable);
1901 -- A variable is set as shared passive if it appears in a shared
1902 -- passive package, and is at the outer level. This is not done
1903 -- for entities generated during expansion, because those are
1904 -- always manipulated locally.
1906 if Is_Shared_Passive (Current_Scope)
1907 and then Is_Library_Level_Entity (Id)
1908 and then Comes_From_Source (Id)
1910 Set_Is_Shared_Passive (Id);
1911 Check_Shared_Var (Id, T, N);
1914 -- Case of no initializing expression present. If the type is not
1915 -- fully initialized, then we set Never_Set_In_Source, since this
1916 -- is a case of a potentially uninitialized object. Note that we
1917 -- do not consider access variables to be fully initialized for
1918 -- this purpose, since it still seems dubious if someone declares
1920 -- Note that we only do this for source declarations. If the object
1921 -- is declared by a generated declaration, we assume that it is not
1922 -- appropriate to generate warnings in that case.
1925 if (Is_Access_Type (T)
1926 or else not Is_Fully_Initialized_Type (T))
1927 and then Comes_From_Source (N)
1929 Set_Never_Set_In_Source (Id);
1934 Init_Alignment (Id);
1937 if Aliased_Present (N) then
1938 Set_Is_Aliased (Id);
1941 and then Is_Record_Type (T)
1942 and then not Is_Constrained (T)
1943 and then Has_Discriminants (T)
1945 Set_Actual_Subtype (Id, Build_Default_Subtype);
1949 Set_Etype (Id, Act_T);
1951 if Has_Controlled_Component (Etype (Id))
1952 or else Is_Controlled (Etype (Id))
1954 if not Is_Library_Level_Entity (Id) then
1955 Check_Restriction (No_Nested_Finalization, N);
1958 Validate_Controlled_Object (Id);
1961 -- Generate a warning when an initialization causes an obvious
1962 -- ABE violation. If the init expression is a simple aggregate
1963 -- there shouldn't be any initialize/adjust call generated. This
1964 -- will be true as soon as aggregates are built in place when
1965 -- possible. ??? at the moment we do not generate warnings for
1966 -- temporaries created for those aggregates although a
1967 -- Program_Error might be generated if compiled with -gnato
1969 if Is_Controlled (Etype (Id))
1970 and then Comes_From_Source (Id)
1973 BT : constant Entity_Id := Base_Type (Etype (Id));
1975 Implicit_Call : Entity_Id;
1976 pragma Warnings (Off, Implicit_Call);
1977 -- What is this about, it is never referenced ???
1979 function Is_Aggr (N : Node_Id) return Boolean;
1980 -- Check that N is an aggregate
1986 function Is_Aggr (N : Node_Id) return Boolean is
1988 case Nkind (Original_Node (N)) is
1989 when N_Aggregate | N_Extension_Aggregate =>
1992 when N_Qualified_Expression |
1994 N_Unchecked_Type_Conversion =>
1995 return Is_Aggr (Expression (Original_Node (N)));
2003 -- If no underlying type, we already are in an error situation
2004 -- don't try to add a warning since we do not have access
2007 if No (Underlying_Type (BT)) then
2008 Implicit_Call := Empty;
2010 -- A generic type does not have usable primitive operators.
2011 -- Initialization calls are built for instances.
2013 elsif Is_Generic_Type (BT) then
2014 Implicit_Call := Empty;
2016 -- if the init expression is not an aggregate, an adjust
2017 -- call will be generated
2019 elsif Present (E) and then not Is_Aggr (E) then
2020 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
2022 -- if no init expression and we are not in the deferred
2023 -- constant case, an Initialize call will be generated
2025 elsif No (E) and then not Constant_Present (N) then
2026 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
2029 Implicit_Call := Empty;
2035 if Has_Task (Etype (Id)) then
2036 Check_Restriction (No_Tasking, N);
2038 if Is_Library_Level_Entity (Id) then
2039 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
2042 Check_Restriction (Max_Tasks, N);
2043 Check_Restriction (No_Task_Hierarchy, N);
2044 Check_Potentially_Blocking_Operation (N);
2047 -- A rather specialized test. If we see two tasks being declared
2048 -- of the same type in the same object declaration, and the task
2049 -- has an entry with an address clause, we know that program error
2050 -- will be raised at run-time since we can't have two tasks with
2051 -- entries at the same address.
2053 if Is_Task_Type (Etype (Id))
2054 and then More_Ids (N)
2060 E := First_Entity (Etype (Id));
2061 while Present (E) loop
2062 if Ekind (E) = E_Entry
2063 and then Present (Get_Attribute_Definition_Clause
2064 (E, Attribute_Address))
2067 ("?more than one task with same entry address", N);
2069 ("\?Program_Error will be raised at run time", N);
2071 Make_Raise_Program_Error (Loc,
2072 Reason => PE_Duplicated_Entry_Address));
2082 -- Some simple constant-propagation: if the expression is a constant
2083 -- string initialized with a literal, share the literal. This avoids
2087 and then Is_Entity_Name (E)
2088 and then Ekind (Entity (E)) = E_Constant
2089 and then Base_Type (Etype (E)) = Standard_String
2092 Val : constant Node_Id := Constant_Value (Entity (E));
2096 and then Nkind (Val) = N_String_Literal
2098 Rewrite (E, New_Copy (Val));
2103 -- Another optimization: if the nominal subtype is unconstrained and
2104 -- the expression is a function call that returns an unconstrained
2105 -- type, rewrite the declaration as a renaming of the result of the
2106 -- call. The exceptions below are cases where the copy is expected,
2107 -- either by the back end (Aliased case) or by the semantics, as for
2108 -- initializing controlled types or copying tags for classwide types.
2111 and then Nkind (E) = N_Explicit_Dereference
2112 and then Nkind (Original_Node (E)) = N_Function_Call
2113 and then not Is_Library_Level_Entity (Id)
2114 and then not Is_Constrained (T)
2115 and then not Is_Aliased (Id)
2116 and then not Is_Class_Wide_Type (T)
2117 and then not Is_Controlled (T)
2118 and then not Has_Controlled_Component (Base_Type (T))
2119 and then Expander_Active
2122 Make_Object_Renaming_Declaration (Loc,
2123 Defining_Identifier => Id,
2124 Access_Definition => Empty,
2125 Subtype_Mark => New_Occurrence_Of
2126 (Base_Type (Etype (Id)), Loc),
2129 Set_Renamed_Object (Id, E);
2131 -- Force generation of debugging information for the constant
2132 -- and for the renamed function call.
2134 Set_Needs_Debug_Info (Id);
2135 Set_Needs_Debug_Info (Entity (Prefix (E)));
2138 if Present (Prev_Entity)
2139 and then Is_Frozen (Prev_Entity)
2140 and then not Error_Posted (Id)
2142 Error_Msg_N ("full constant declaration appears too late", N);
2145 Check_Eliminated (Id);
2146 end Analyze_Object_Declaration;
2148 ---------------------------
2149 -- Analyze_Others_Choice --
2150 ---------------------------
2152 -- Nothing to do for the others choice node itself, the semantic analysis
2153 -- of the others choice will occur as part of the processing of the parent
2155 procedure Analyze_Others_Choice (N : Node_Id) is
2156 pragma Warnings (Off, N);
2160 end Analyze_Others_Choice;
2162 --------------------------------
2163 -- Analyze_Per_Use_Expression --
2164 --------------------------------
2166 procedure Analyze_Per_Use_Expression (N : Node_Id; T : Entity_Id) is
2167 Save_In_Default_Expression : constant Boolean := In_Default_Expression;
2170 In_Default_Expression := True;
2171 Pre_Analyze_And_Resolve (N, T);
2172 In_Default_Expression := Save_In_Default_Expression;
2173 end Analyze_Per_Use_Expression;
2175 -------------------------------------------
2176 -- Analyze_Private_Extension_Declaration --
2177 -------------------------------------------
2179 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
2180 T : constant Entity_Id := Defining_Identifier (N);
2181 Indic : constant Node_Id := Subtype_Indication (N);
2182 Parent_Type : Entity_Id;
2183 Parent_Base : Entity_Id;
2186 Generate_Definition (T);
2189 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
2190 Parent_Base := Base_Type (Parent_Type);
2192 if Parent_Type = Any_Type
2193 or else Etype (Parent_Type) = Any_Type
2195 Set_Ekind (T, Ekind (Parent_Type));
2196 Set_Etype (T, Any_Type);
2199 elsif not Is_Tagged_Type (Parent_Type) then
2201 ("parent of type extension must be a tagged type ", Indic);
2204 elsif Ekind (Parent_Type) = E_Void
2205 or else Ekind (Parent_Type) = E_Incomplete_Type
2207 Error_Msg_N ("premature derivation of incomplete type", Indic);
2211 -- Perhaps the parent type should be changed to the class-wide type's
2212 -- specific type in this case to prevent cascading errors ???
2214 if Is_Class_Wide_Type (Parent_Type) then
2216 ("parent of type extension must not be a class-wide type", Indic);
2220 if (not Is_Package (Current_Scope)
2221 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
2222 or else In_Private_Part (Current_Scope)
2225 Error_Msg_N ("invalid context for private extension", N);
2228 -- Set common attributes
2230 Set_Is_Pure (T, Is_Pure (Current_Scope));
2231 Set_Scope (T, Current_Scope);
2232 Set_Ekind (T, E_Record_Type_With_Private);
2233 Init_Size_Align (T);
2235 Set_Etype (T, Parent_Base);
2236 Set_Has_Task (T, Has_Task (Parent_Base));
2238 Set_Convention (T, Convention (Parent_Type));
2239 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
2240 Set_Is_First_Subtype (T);
2241 Make_Class_Wide_Type (T);
2243 if Unknown_Discriminants_Present (N) then
2244 Set_Discriminant_Constraint (T, No_Elist);
2247 Build_Derived_Record_Type (N, Parent_Type, T);
2248 end Analyze_Private_Extension_Declaration;
2250 ---------------------------------
2251 -- Analyze_Subtype_Declaration --
2252 ---------------------------------
2254 procedure Analyze_Subtype_Declaration (N : Node_Id) is
2255 Id : constant Entity_Id := Defining_Identifier (N);
2257 R_Checks : Check_Result;
2260 Generate_Definition (Id);
2261 Set_Is_Pure (Id, Is_Pure (Current_Scope));
2262 Init_Size_Align (Id);
2264 -- The following guard condition on Enter_Name is to handle cases
2265 -- where the defining identifier has already been entered into the
2266 -- scope but the declaration as a whole needs to be analyzed.
2268 -- This case in particular happens for derived enumeration types.
2269 -- The derived enumeration type is processed as an inserted enumeration
2270 -- type declaration followed by a rewritten subtype declaration. The
2271 -- defining identifier, however, is entered into the name scope very
2272 -- early in the processing of the original type declaration and
2273 -- therefore needs to be avoided here, when the created subtype
2274 -- declaration is analyzed. (See Build_Derived_Types)
2276 -- This also happens when the full view of a private type is a
2277 -- derived type with constraints. In this case the entity has been
2278 -- introduced in the private declaration.
2280 if Present (Etype (Id))
2281 and then (Is_Private_Type (Etype (Id))
2282 or else Is_Task_Type (Etype (Id))
2283 or else Is_Rewrite_Substitution (N))
2291 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
2293 -- Inherit common attributes
2295 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
2296 Set_Is_Volatile (Id, Is_Volatile (T));
2297 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
2298 Set_Is_Atomic (Id, Is_Atomic (T));
2300 -- In the case where there is no constraint given in the subtype
2301 -- indication, Process_Subtype just returns the Subtype_Mark,
2302 -- so its semantic attributes must be established here.
2304 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
2305 Set_Etype (Id, Base_Type (T));
2309 Set_Ekind (Id, E_Array_Subtype);
2310 Copy_Array_Subtype_Attributes (Id, T);
2312 when Decimal_Fixed_Point_Kind =>
2313 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
2314 Set_Digits_Value (Id, Digits_Value (T));
2315 Set_Delta_Value (Id, Delta_Value (T));
2316 Set_Scale_Value (Id, Scale_Value (T));
2317 Set_Small_Value (Id, Small_Value (T));
2318 Set_Scalar_Range (Id, Scalar_Range (T));
2319 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
2320 Set_Is_Constrained (Id, Is_Constrained (T));
2321 Set_RM_Size (Id, RM_Size (T));
2323 when Enumeration_Kind =>
2324 Set_Ekind (Id, E_Enumeration_Subtype);
2325 Set_First_Literal (Id, First_Literal (Base_Type (T)));
2326 Set_Scalar_Range (Id, Scalar_Range (T));
2327 Set_Is_Character_Type (Id, Is_Character_Type (T));
2328 Set_Is_Constrained (Id, Is_Constrained (T));
2329 Set_RM_Size (Id, RM_Size (T));
2331 when Ordinary_Fixed_Point_Kind =>
2332 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
2333 Set_Scalar_Range (Id, Scalar_Range (T));
2334 Set_Small_Value (Id, Small_Value (T));
2335 Set_Delta_Value (Id, Delta_Value (T));
2336 Set_Is_Constrained (Id, Is_Constrained (T));
2337 Set_RM_Size (Id, RM_Size (T));
2340 Set_Ekind (Id, E_Floating_Point_Subtype);
2341 Set_Scalar_Range (Id, Scalar_Range (T));
2342 Set_Digits_Value (Id, Digits_Value (T));
2343 Set_Is_Constrained (Id, Is_Constrained (T));
2345 when Signed_Integer_Kind =>
2346 Set_Ekind (Id, E_Signed_Integer_Subtype);
2347 Set_Scalar_Range (Id, Scalar_Range (T));
2348 Set_Is_Constrained (Id, Is_Constrained (T));
2349 Set_RM_Size (Id, RM_Size (T));
2351 when Modular_Integer_Kind =>
2352 Set_Ekind (Id, E_Modular_Integer_Subtype);
2353 Set_Scalar_Range (Id, Scalar_Range (T));
2354 Set_Is_Constrained (Id, Is_Constrained (T));
2355 Set_RM_Size (Id, RM_Size (T));
2357 when Class_Wide_Kind =>
2358 Set_Ekind (Id, E_Class_Wide_Subtype);
2359 Set_First_Entity (Id, First_Entity (T));
2360 Set_Last_Entity (Id, Last_Entity (T));
2361 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2362 Set_Cloned_Subtype (Id, T);
2363 Set_Is_Tagged_Type (Id, True);
2364 Set_Has_Unknown_Discriminants
2367 if Ekind (T) = E_Class_Wide_Subtype then
2368 Set_Equivalent_Type (Id, Equivalent_Type (T));
2371 when E_Record_Type | E_Record_Subtype =>
2372 Set_Ekind (Id, E_Record_Subtype);
2374 if Ekind (T) = E_Record_Subtype
2375 and then Present (Cloned_Subtype (T))
2377 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
2379 Set_Cloned_Subtype (Id, T);
2382 Set_First_Entity (Id, First_Entity (T));
2383 Set_Last_Entity (Id, Last_Entity (T));
2384 Set_Has_Discriminants (Id, Has_Discriminants (T));
2385 Set_Is_Constrained (Id, Is_Constrained (T));
2386 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2387 Set_Has_Unknown_Discriminants
2388 (Id, Has_Unknown_Discriminants (T));
2390 if Has_Discriminants (T) then
2391 Set_Discriminant_Constraint
2392 (Id, Discriminant_Constraint (T));
2393 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2395 elsif Has_Unknown_Discriminants (Id) then
2396 Set_Discriminant_Constraint (Id, No_Elist);
2399 if Is_Tagged_Type (T) then
2400 Set_Is_Tagged_Type (Id);
2401 Set_Is_Abstract (Id, Is_Abstract (T));
2402 Set_Primitive_Operations
2403 (Id, Primitive_Operations (T));
2404 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2407 when Private_Kind =>
2408 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2409 Set_Has_Discriminants (Id, Has_Discriminants (T));
2410 Set_Is_Constrained (Id, Is_Constrained (T));
2411 Set_First_Entity (Id, First_Entity (T));
2412 Set_Last_Entity (Id, Last_Entity (T));
2413 Set_Private_Dependents (Id, New_Elmt_List);
2414 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2415 Set_Has_Unknown_Discriminants
2416 (Id, Has_Unknown_Discriminants (T));
2418 if Is_Tagged_Type (T) then
2419 Set_Is_Tagged_Type (Id);
2420 Set_Is_Abstract (Id, Is_Abstract (T));
2421 Set_Primitive_Operations
2422 (Id, Primitive_Operations (T));
2423 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2426 -- In general the attributes of the subtype of a private
2427 -- type are the attributes of the partial view of parent.
2428 -- However, the full view may be a discriminated type,
2429 -- and the subtype must share the discriminant constraint
2430 -- to generate correct calls to initialization procedures.
2432 if Has_Discriminants (T) then
2433 Set_Discriminant_Constraint
2434 (Id, Discriminant_Constraint (T));
2435 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2437 elsif Present (Full_View (T))
2438 and then Has_Discriminants (Full_View (T))
2440 Set_Discriminant_Constraint
2441 (Id, Discriminant_Constraint (Full_View (T)));
2442 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2444 -- This would seem semantically correct, but apparently
2445 -- confuses the back-end (4412-009). To be explained ???
2447 -- Set_Has_Discriminants (Id);
2450 Prepare_Private_Subtype_Completion (Id, N);
2453 Set_Ekind (Id, E_Access_Subtype);
2454 Set_Is_Constrained (Id, Is_Constrained (T));
2455 Set_Is_Access_Constant
2456 (Id, Is_Access_Constant (T));
2457 Set_Directly_Designated_Type
2458 (Id, Designated_Type (T));
2460 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
2461 -- and carry out some static checks
2463 if Null_Exclusion_Present (N)
2464 or else Can_Never_Be_Null (T)
2466 Set_Can_Never_Be_Null (Id);
2468 if Null_Exclusion_Present (N)
2469 and then Can_Never_Be_Null (T)
2472 ("(Ada 2005) null exclusion not allowed if parent "
2473 & "is already non-null", Subtype_Indication (N));
2477 -- A Pure library_item must not contain the declaration of a
2478 -- named access type, except within a subprogram, generic
2479 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
2481 if Comes_From_Source (Id)
2482 and then In_Pure_Unit
2483 and then not In_Subprogram_Task_Protected_Unit
2486 ("named access types not allowed in pure unit", N);
2489 when Concurrent_Kind =>
2490 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2491 Set_Corresponding_Record_Type (Id,
2492 Corresponding_Record_Type (T));
2493 Set_First_Entity (Id, First_Entity (T));
2494 Set_First_Private_Entity (Id, First_Private_Entity (T));
2495 Set_Has_Discriminants (Id, Has_Discriminants (T));
2496 Set_Is_Constrained (Id, Is_Constrained (T));
2497 Set_Last_Entity (Id, Last_Entity (T));
2499 if Has_Discriminants (T) then
2500 Set_Discriminant_Constraint (Id,
2501 Discriminant_Constraint (T));
2502 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
2505 -- If the subtype name denotes an incomplete type
2506 -- an error was already reported by Process_Subtype.
2508 when E_Incomplete_Type =>
2509 Set_Etype (Id, Any_Type);
2512 raise Program_Error;
2516 if Etype (Id) = Any_Type then
2520 -- Some common processing on all types
2522 Set_Size_Info (Id, T);
2523 Set_First_Rep_Item (Id, First_Rep_Item (T));
2527 Set_Is_Immediately_Visible (Id, True);
2528 Set_Depends_On_Private (Id, Has_Private_Component (T));
2530 if Present (Generic_Parent_Type (N))
2533 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
2535 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
2536 /= N_Formal_Private_Type_Definition)
2538 if Is_Tagged_Type (Id) then
2539 if Is_Class_Wide_Type (Id) then
2540 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
2542 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
2545 elsif Scope (Etype (Id)) /= Standard_Standard then
2546 Derive_Subprograms (Generic_Parent_Type (N), Id);
2550 if Is_Private_Type (T)
2551 and then Present (Full_View (T))
2553 Conditional_Delay (Id, Full_View (T));
2555 -- The subtypes of components or subcomponents of protected types
2556 -- do not need freeze nodes, which would otherwise appear in the
2557 -- wrong scope (before the freeze node for the protected type). The
2558 -- proper subtypes are those of the subcomponents of the corresponding
2561 elsif Ekind (Scope (Id)) /= E_Protected_Type
2562 and then Present (Scope (Scope (Id))) -- error defense!
2563 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
2565 Conditional_Delay (Id, T);
2568 -- Check that constraint_error is raised for a scalar subtype
2569 -- indication when the lower or upper bound of a non-null range
2570 -- lies outside the range of the type mark.
2572 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
2573 if Is_Scalar_Type (Etype (Id))
2574 and then Scalar_Range (Id) /=
2575 Scalar_Range (Etype (Subtype_Mark
2576 (Subtype_Indication (N))))
2580 Etype (Subtype_Mark (Subtype_Indication (N))));
2582 elsif Is_Array_Type (Etype (Id))
2583 and then Present (First_Index (Id))
2585 -- This really should be a subprogram that finds the indications
2588 if ((Nkind (First_Index (Id)) = N_Identifier
2589 and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
2590 or else Nkind (First_Index (Id)) = N_Subtype_Indication)
2592 Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
2595 Target_Typ : constant Entity_Id :=
2598 (Subtype_Mark (Subtype_Indication (N)))));
2602 (Scalar_Range (Etype (First_Index (Id))),
2604 Etype (First_Index (Id)),
2605 Defining_Identifier (N));
2611 Sloc (Defining_Identifier (N)));
2617 Check_Eliminated (Id);
2618 end Analyze_Subtype_Declaration;
2620 --------------------------------
2621 -- Analyze_Subtype_Indication --
2622 --------------------------------
2624 procedure Analyze_Subtype_Indication (N : Node_Id) is
2625 T : constant Entity_Id := Subtype_Mark (N);
2626 R : constant Node_Id := Range_Expression (Constraint (N));
2633 Set_Etype (N, Etype (R));
2635 Set_Error_Posted (R);
2636 Set_Error_Posted (T);
2638 end Analyze_Subtype_Indication;
2640 ------------------------------
2641 -- Analyze_Type_Declaration --
2642 ------------------------------
2644 procedure Analyze_Type_Declaration (N : Node_Id) is
2645 Def : constant Node_Id := Type_Definition (N);
2646 Def_Id : constant Entity_Id := Defining_Identifier (N);
2650 Is_Remote : constant Boolean :=
2651 (Is_Remote_Types (Current_Scope)
2652 or else Is_Remote_Call_Interface (Current_Scope))
2653 and then not (In_Private_Part (Current_Scope)
2655 In_Package_Body (Current_Scope));
2658 Prev := Find_Type_Name (N);
2660 -- The full view, if present, now points to the current type
2662 -- Ada 2005 (AI-50217): If the type was previously decorated when
2663 -- imported through a LIMITED WITH clause, it appears as incomplete
2664 -- but has no full view.
2666 if Ekind (Prev) = E_Incomplete_Type
2667 and then Present (Full_View (Prev))
2669 T := Full_View (Prev);
2674 Set_Is_Pure (T, Is_Pure (Current_Scope));
2676 -- We set the flag Is_First_Subtype here. It is needed to set the
2677 -- corresponding flag for the Implicit class-wide-type created
2678 -- during tagged types processing.
2680 Set_Is_First_Subtype (T, True);
2682 -- Only composite types other than array types are allowed to have
2687 -- For derived types, the rule will be checked once we've figured
2688 -- out the parent type.
2690 when N_Derived_Type_Definition =>
2693 -- For record types, discriminants are allowed.
2695 when N_Record_Definition =>
2699 if Present (Discriminant_Specifications (N)) then
2701 ("elementary or array type cannot have discriminants",
2703 (First (Discriminant_Specifications (N))));
2707 -- Elaborate the type definition according to kind, and generate
2708 -- subsidiary (implicit) subtypes where needed. We skip this if
2709 -- it was already done (this happens during the reanalysis that
2710 -- follows a call to the high level optimizer).
2712 if not Analyzed (T) then
2717 when N_Access_To_Subprogram_Definition =>
2718 Access_Subprogram_Declaration (T, Def);
2720 -- If this is a remote access to subprogram, we must create
2721 -- the equivalent fat pointer type, and related subprograms.
2724 Process_Remote_AST_Declaration (N);
2727 -- Validate categorization rule against access type declaration
2728 -- usually a violation in Pure unit, Shared_Passive unit.
2730 Validate_Access_Type_Declaration (T, N);
2732 when N_Access_To_Object_Definition =>
2733 Access_Type_Declaration (T, Def);
2735 -- Validate categorization rule against access type declaration
2736 -- usually a violation in Pure unit, Shared_Passive unit.
2738 Validate_Access_Type_Declaration (T, N);
2740 -- If we are in a Remote_Call_Interface package and define
2741 -- a RACW, Read and Write attribute must be added.
2744 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2746 Add_RACW_Features (Def_Id);
2749 -- Set no strict aliasing flag if config pragma seen
2751 if Opt.No_Strict_Aliasing then
2752 Set_No_Strict_Aliasing (Base_Type (Def_Id));
2755 when N_Array_Type_Definition =>
2756 Array_Type_Declaration (T, Def);
2758 when N_Derived_Type_Definition =>
2759 Derived_Type_Declaration (T, N, T /= Def_Id);
2761 when N_Enumeration_Type_Definition =>
2762 Enumeration_Type_Declaration (T, Def);
2764 when N_Floating_Point_Definition =>
2765 Floating_Point_Type_Declaration (T, Def);
2767 when N_Decimal_Fixed_Point_Definition =>
2768 Decimal_Fixed_Point_Type_Declaration (T, Def);
2770 when N_Ordinary_Fixed_Point_Definition =>
2771 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2773 when N_Signed_Integer_Type_Definition =>
2774 Signed_Integer_Type_Declaration (T, Def);
2776 when N_Modular_Type_Definition =>
2777 Modular_Type_Declaration (T, Def);
2779 when N_Record_Definition =>
2780 Record_Type_Declaration (T, N, Prev);
2783 raise Program_Error;
2788 if Etype (T) = Any_Type then
2792 -- Some common processing for all types
2794 Set_Depends_On_Private (T, Has_Private_Component (T));
2796 -- Both the declared entity, and its anonymous base type if one
2797 -- was created, need freeze nodes allocated.
2800 B : constant Entity_Id := Base_Type (T);
2803 -- In the case where the base type is different from the first
2804 -- subtype, we pre-allocate a freeze node, and set the proper
2805 -- link to the first subtype. Freeze_Entity will use this
2806 -- preallocated freeze node when it freezes the entity.
2809 Ensure_Freeze_Node (B);
2810 Set_First_Subtype_Link (Freeze_Node (B), T);
2813 if not From_With_Type (T) then
2814 Set_Has_Delayed_Freeze (T);
2818 -- Case of T is the full declaration of some private type which has
2819 -- been swapped in Defining_Identifier (N).
2821 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2822 Process_Full_View (N, T, Def_Id);
2824 -- Record the reference. The form of this is a little strange,
2825 -- since the full declaration has been swapped in. So the first
2826 -- parameter here represents the entity to which a reference is
2827 -- made which is the "real" entity, i.e. the one swapped in,
2828 -- and the second parameter provides the reference location.
2830 Generate_Reference (T, T, 'c');
2831 Set_Completion_Referenced (Def_Id);
2833 -- For completion of incomplete type, process incomplete dependents
2834 -- and always mark the full type as referenced (it is the incomplete
2835 -- type that we get for any real reference).
2837 elsif Ekind (Prev) = E_Incomplete_Type then
2838 Process_Incomplete_Dependents (N, T, Prev);
2839 Generate_Reference (Prev, Def_Id, 'c');
2840 Set_Completion_Referenced (Def_Id);
2842 -- If not private type or incomplete type completion, this is a real
2843 -- definition of a new entity, so record it.
2846 Generate_Definition (Def_Id);
2849 Check_Eliminated (Def_Id);
2850 end Analyze_Type_Declaration;
2852 --------------------------
2853 -- Analyze_Variant_Part --
2854 --------------------------
2856 procedure Analyze_Variant_Part (N : Node_Id) is
2858 procedure Non_Static_Choice_Error (Choice : Node_Id);
2859 -- Error routine invoked by the generic instantiation below when
2860 -- the variant part has a non static choice.
2862 procedure Process_Declarations (Variant : Node_Id);
2863 -- Analyzes all the declarations associated with a Variant.
2864 -- Needed by the generic instantiation below.
2866 package Variant_Choices_Processing is new
2867 Generic_Choices_Processing
2868 (Get_Alternatives => Variants,
2869 Get_Choices => Discrete_Choices,
2870 Process_Empty_Choice => No_OP,
2871 Process_Non_Static_Choice => Non_Static_Choice_Error,
2872 Process_Associated_Node => Process_Declarations);
2873 use Variant_Choices_Processing;
2874 -- Instantiation of the generic choice processing package.
2876 -----------------------------
2877 -- Non_Static_Choice_Error --
2878 -----------------------------
2880 procedure Non_Static_Choice_Error (Choice : Node_Id) is
2882 Flag_Non_Static_Expr
2883 ("choice given in variant part is not static!", Choice);
2884 end Non_Static_Choice_Error;
2886 --------------------------
2887 -- Process_Declarations --
2888 --------------------------
2890 procedure Process_Declarations (Variant : Node_Id) is
2892 if not Null_Present (Component_List (Variant)) then
2893 Analyze_Declarations (Component_Items (Component_List (Variant)));
2895 if Present (Variant_Part (Component_List (Variant))) then
2896 Analyze (Variant_Part (Component_List (Variant)));
2899 end Process_Declarations;
2901 -- Variables local to Analyze_Case_Statement.
2903 Discr_Name : Node_Id;
2904 Discr_Type : Entity_Id;
2906 Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
2908 Dont_Care : Boolean;
2909 Others_Present : Boolean := False;
2911 -- Start of processing for Analyze_Variant_Part
2914 Discr_Name := Name (N);
2915 Analyze (Discr_Name);
2917 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
2918 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
2921 Discr_Type := Etype (Entity (Discr_Name));
2923 if not Is_Discrete_Type (Discr_Type) then
2925 ("discriminant in a variant part must be of a discrete type",
2930 -- Call the instantiated Analyze_Choices which does the rest of the work
2933 (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
2934 end Analyze_Variant_Part;
2936 ----------------------------
2937 -- Array_Type_Declaration --
2938 ----------------------------
2940 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
2941 Component_Def : constant Node_Id := Component_Definition (Def);
2942 Element_Type : Entity_Id;
2943 Implicit_Base : Entity_Id;
2945 Related_Id : Entity_Id := Empty;
2947 P : constant Node_Id := Parent (Def);
2951 if Nkind (Def) = N_Constrained_Array_Definition then
2952 Index := First (Discrete_Subtype_Definitions (Def));
2954 Index := First (Subtype_Marks (Def));
2957 -- Find proper names for the implicit types which may be public.
2958 -- in case of anonymous arrays we use the name of the first object
2959 -- of that type as prefix.
2962 Related_Id := Defining_Identifier (P);
2969 while Present (Index) loop
2971 Make_Index (Index, P, Related_Id, Nb_Index);
2973 Nb_Index := Nb_Index + 1;
2976 if Present (Subtype_Indication (Component_Def)) then
2977 Element_Type := Process_Subtype (Subtype_Indication (Component_Def),
2978 P, Related_Id, 'C');
2980 -- Ada 2005 (AI-230): Access Definition case
2982 else pragma Assert (Present (Access_Definition (Component_Def)));
2983 Element_Type := Access_Definition
2984 (Related_Nod => Related_Id,
2985 N => Access_Definition (Component_Def));
2987 -- Ada 2005 (AI-230): In case of components that are anonymous
2988 -- access types the level of accessibility depends on the enclosing
2991 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
2993 -- Ada 2005 (AI-254)
2996 CD : constant Node_Id :=
2997 Access_To_Subprogram_Definition
2998 (Access_Definition (Component_Def));
3000 if Present (CD) and then Protected_Present (CD) then
3002 Replace_Anonymous_Access_To_Protected_Subprogram
3003 (Def, Element_Type);
3008 -- Constrained array case
3011 T := Create_Itype (E_Void, P, Related_Id, 'T');
3014 if Nkind (Def) = N_Constrained_Array_Definition then
3016 -- Establish Implicit_Base as unconstrained base type
3018 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
3020 Init_Size_Align (Implicit_Base);
3021 Set_Etype (Implicit_Base, Implicit_Base);
3022 Set_Scope (Implicit_Base, Current_Scope);
3023 Set_Has_Delayed_Freeze (Implicit_Base);
3025 -- The constrained array type is a subtype of the unconstrained one
3027 Set_Ekind (T, E_Array_Subtype);
3028 Init_Size_Align (T);
3029 Set_Etype (T, Implicit_Base);
3030 Set_Scope (T, Current_Scope);
3031 Set_Is_Constrained (T, True);
3032 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
3033 Set_Has_Delayed_Freeze (T);
3035 -- Complete setup of implicit base type
3037 Set_First_Index (Implicit_Base, First_Index (T));
3038 Set_Component_Type (Implicit_Base, Element_Type);
3039 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
3040 Set_Component_Size (Implicit_Base, Uint_0);
3041 Set_Has_Controlled_Component
3042 (Implicit_Base, Has_Controlled_Component
3045 Is_Controlled (Element_Type));
3046 Set_Finalize_Storage_Only
3047 (Implicit_Base, Finalize_Storage_Only
3050 -- Unconstrained array case
3053 Set_Ekind (T, E_Array_Type);
3054 Init_Size_Align (T);
3056 Set_Scope (T, Current_Scope);
3057 Set_Component_Size (T, Uint_0);
3058 Set_Is_Constrained (T, False);
3059 Set_First_Index (T, First (Subtype_Marks (Def)));
3060 Set_Has_Delayed_Freeze (T, True);
3061 Set_Has_Task (T, Has_Task (Element_Type));
3062 Set_Has_Controlled_Component (T, Has_Controlled_Component
3065 Is_Controlled (Element_Type));
3066 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
3070 Set_Component_Type (Base_Type (T), Element_Type);
3072 if Aliased_Present (Component_Definition (Def)) then
3073 Set_Has_Aliased_Components (Etype (T));
3076 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
3077 -- array to ensure that objects of this type are initialized.
3079 if Ada_Version >= Ada_05
3080 and then (Null_Exclusion_Present (Component_Definition (Def))
3081 or else Can_Never_Be_Null (Element_Type))
3083 Set_Can_Never_Be_Null (T);
3085 if Null_Exclusion_Present (Component_Definition (Def))
3086 and then Can_Never_Be_Null (Element_Type)
3089 ("(Ada 2005) already a null-excluding type",
3090 Subtype_Indication (Component_Definition (Def)));
3094 Priv := Private_Component (Element_Type);
3096 if Present (Priv) then
3098 -- Check for circular definitions
3100 if Priv = Any_Type then
3101 Set_Component_Type (Etype (T), Any_Type);
3103 -- There is a gap in the visibility of operations on the composite
3104 -- type only if the component type is defined in a different scope.
3106 elsif Scope (Priv) = Current_Scope then
3109 elsif Is_Limited_Type (Priv) then
3110 Set_Is_Limited_Composite (Etype (T));
3111 Set_Is_Limited_Composite (T);
3113 Set_Is_Private_Composite (Etype (T));
3114 Set_Is_Private_Composite (T);
3118 -- Create a concatenation operator for the new type. Internal
3119 -- array types created for packed entities do not need such, they
3120 -- are compatible with the user-defined type.
3122 if Number_Dimensions (T) = 1
3123 and then not Is_Packed_Array_Type (T)
3125 New_Concatenation_Op (T);
3128 -- In the case of an unconstrained array the parser has already
3129 -- verified that all the indices are unconstrained but we still
3130 -- need to make sure that the element type is constrained.
3132 if Is_Indefinite_Subtype (Element_Type) then
3134 ("unconstrained element type in array declaration",
3135 Subtype_Indication (Component_Def));
3137 elsif Is_Abstract (Element_Type) then
3139 ("The type of a component cannot be abstract",
3140 Subtype_Indication (Component_Def));
3143 end Array_Type_Declaration;
3145 ------------------------------------------------------
3146 -- Replace_Anonymous_Access_To_Protected_Subprogram --
3147 ------------------------------------------------------
3149 function Replace_Anonymous_Access_To_Protected_Subprogram
3151 Prev_E : Entity_Id) return Entity_Id
3153 Loc : constant Source_Ptr := Sloc (N);
3155 Curr_Scope : constant Scope_Stack_Entry :=
3156 Scope_Stack.Table (Scope_Stack.Last);
3158 Anon : constant Entity_Id :=
3159 Make_Defining_Identifier (Loc,
3160 Chars => New_Internal_Name ('S'));
3165 P : Node_Id := Parent (N);
3168 Set_Is_Internal (Anon);
3171 when N_Component_Declaration |
3172 N_Unconstrained_Array_Definition |
3173 N_Constrained_Array_Definition =>
3174 Comp := Component_Definition (N);
3175 Acc := Access_Definition (Component_Definition (N));
3177 when N_Discriminant_Specification =>
3178 Comp := Discriminant_Type (N);
3179 Acc := Discriminant_Type (N);
3181 when N_Parameter_Specification =>
3182 Comp := Parameter_Type (N);
3183 Acc := Parameter_Type (N);
3186 raise Program_Error;
3189 Decl := Make_Full_Type_Declaration (Loc,
3190 Defining_Identifier => Anon,
3192 Copy_Separate_Tree (Access_To_Subprogram_Definition (Acc)));
3194 Mark_Rewrite_Insertion (Decl);
3196 -- Insert the new declaration in the nearest enclosing scope
3198 while Present (P) and then not Has_Declarations (P) loop
3202 pragma Assert (Present (P));
3204 if Nkind (P) = N_Package_Specification then
3205 Prepend (Decl, Visible_Declarations (P));
3207 Prepend (Decl, Declarations (P));
3210 -- Replace the anonymous type with an occurrence of the new declaration.
3211 -- In all cases the rewriten node does not have the null-exclusion
3212 -- attribute because (if present) it was already inherited by the
3213 -- anonymous entity (Anon). Thus, in case of components we do not
3214 -- inherit this attribute.
3216 if Nkind (N) = N_Parameter_Specification then
3217 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
3218 Set_Etype (Defining_Identifier (N), Anon);
3219 Set_Null_Exclusion_Present (N, False);
3222 Make_Component_Definition (Loc,
3223 Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
3226 Mark_Rewrite_Insertion (Comp);
3228 -- Temporarily remove the current scope from the stack to add the new
3229 -- declarations to the enclosing scope
3231 Scope_Stack.Decrement_Last;
3233 Scope_Stack.Append (Curr_Scope);
3235 Set_Original_Access_Type (Anon, Prev_E);
3237 end Replace_Anonymous_Access_To_Protected_Subprogram;
3239 -------------------------------
3240 -- Build_Derived_Access_Type --
3241 -------------------------------
3243 procedure Build_Derived_Access_Type
3245 Parent_Type : Entity_Id;
3246 Derived_Type : Entity_Id)
3248 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
3250 Desig_Type : Entity_Id;
3252 Discr_Con_Elist : Elist_Id;
3253 Discr_Con_El : Elmt_Id;
3257 -- Set the designated type so it is available in case this is
3258 -- an access to a self-referential type, e.g. a standard list
3259 -- type with a next pointer. Will be reset after subtype is built.
3261 Set_Directly_Designated_Type
3262 (Derived_Type, Designated_Type (Parent_Type));
3264 Subt := Process_Subtype (S, N);
3266 if Nkind (S) /= N_Subtype_Indication
3267 and then Subt /= Base_Type (Subt)
3269 Set_Ekind (Derived_Type, E_Access_Subtype);
3272 if Ekind (Derived_Type) = E_Access_Subtype then
3274 Pbase : constant Entity_Id := Base_Type (Parent_Type);
3275 Ibase : constant Entity_Id :=
3276 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
3277 Svg_Chars : constant Name_Id := Chars (Ibase);
3278 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
3281 Copy_Node (Pbase, Ibase);
3283 Set_Chars (Ibase, Svg_Chars);
3284 Set_Next_Entity (Ibase, Svg_Next_E);
3285 Set_Sloc (Ibase, Sloc (Derived_Type));
3286 Set_Scope (Ibase, Scope (Derived_Type));
3287 Set_Freeze_Node (Ibase, Empty);
3288 Set_Is_Frozen (Ibase, False);
3289 Set_Comes_From_Source (Ibase, False);
3290 Set_Is_First_Subtype (Ibase, False);
3292 Set_Etype (Ibase, Pbase);
3293 Set_Etype (Derived_Type, Ibase);
3297 Set_Directly_Designated_Type
3298 (Derived_Type, Designated_Type (Subt));
3300 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
3301 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
3302 Set_Size_Info (Derived_Type, Parent_Type);
3303 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
3304 Set_Depends_On_Private (Derived_Type,
3305 Has_Private_Component (Derived_Type));
3306 Conditional_Delay (Derived_Type, Subt);
3308 -- Ada 2005 (AI-231). Set the null-exclusion attribute
3310 if Null_Exclusion_Present (Type_Definition (N))
3311 or else Can_Never_Be_Null (Parent_Type)
3313 Set_Can_Never_Be_Null (Derived_Type);
3316 -- Note: we do not copy the Storage_Size_Variable, since
3317 -- we always go to the root type for this information.
3319 -- Apply range checks to discriminants for derived record case
3320 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
3322 Desig_Type := Designated_Type (Derived_Type);
3323 if Is_Composite_Type (Desig_Type)
3324 and then (not Is_Array_Type (Desig_Type))
3325 and then Has_Discriminants (Desig_Type)
3326 and then Base_Type (Desig_Type) /= Desig_Type
3328 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
3329 Discr_Con_El := First_Elmt (Discr_Con_Elist);
3331 Discr := First_Discriminant (Base_Type (Desig_Type));
3332 while Present (Discr_Con_El) loop
3333 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
3334 Next_Elmt (Discr_Con_El);
3335 Next_Discriminant (Discr);
3338 end Build_Derived_Access_Type;
3340 ------------------------------
3341 -- Build_Derived_Array_Type --
3342 ------------------------------
3344 procedure Build_Derived_Array_Type
3346 Parent_Type : Entity_Id;
3347 Derived_Type : Entity_Id)
3349 Loc : constant Source_Ptr := Sloc (N);
3350 Tdef : constant Node_Id := Type_Definition (N);
3351 Indic : constant Node_Id := Subtype_Indication (Tdef);
3352 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3353 Implicit_Base : Entity_Id;
3354 New_Indic : Node_Id;
3356 procedure Make_Implicit_Base;
3357 -- If the parent subtype is constrained, the derived type is a
3358 -- subtype of an implicit base type derived from the parent base.
3360 ------------------------
3361 -- Make_Implicit_Base --
3362 ------------------------
3364 procedure Make_Implicit_Base is
3367 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3369 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3370 Set_Etype (Implicit_Base, Parent_Base);
3372 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
3373 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
3375 Set_Has_Delayed_Freeze (Implicit_Base, True);
3376 end Make_Implicit_Base;
3378 -- Start of processing for Build_Derived_Array_Type
3381 if not Is_Constrained (Parent_Type) then
3382 if Nkind (Indic) /= N_Subtype_Indication then
3383 Set_Ekind (Derived_Type, E_Array_Type);
3385 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
3386 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
3388 Set_Has_Delayed_Freeze (Derived_Type, True);
3392 Set_Etype (Derived_Type, Implicit_Base);
3395 Make_Subtype_Declaration (Loc,
3396 Defining_Identifier => Derived_Type,
3397 Subtype_Indication =>
3398 Make_Subtype_Indication (Loc,
3399 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
3400 Constraint => Constraint (Indic)));
3402 Rewrite (N, New_Indic);
3407 if Nkind (Indic) /= N_Subtype_Indication then
3410 Set_Ekind (Derived_Type, Ekind (Parent_Type));
3411 Set_Etype (Derived_Type, Implicit_Base);
3412 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
3415 Error_Msg_N ("illegal constraint on constrained type", Indic);
3419 -- If the parent type is not a derived type itself, and is
3420 -- declared in a closed scope (e.g., a subprogram), then we
3421 -- need to explicitly introduce the new type's concatenation
3422 -- operator since Derive_Subprograms will not inherit the
3423 -- parent's operator. If the parent type is unconstrained, the
3424 -- operator is of the unconstrained base type.
3426 if Number_Dimensions (Parent_Type) = 1
3427 and then not Is_Limited_Type (Parent_Type)
3428 and then not Is_Derived_Type (Parent_Type)
3429 and then not Is_Package (Scope (Base_Type (Parent_Type)))
3431 if not Is_Constrained (Parent_Type)
3432 and then Is_Constrained (Derived_Type)
3434 New_Concatenation_Op (Implicit_Base);
3436 New_Concatenation_Op (Derived_Type);
3439 end Build_Derived_Array_Type;
3441 -----------------------------------
3442 -- Build_Derived_Concurrent_Type --
3443 -----------------------------------
3445 procedure Build_Derived_Concurrent_Type
3447 Parent_Type : Entity_Id;
3448 Derived_Type : Entity_Id)
3450 D_Constraint : Node_Id;
3451 Disc_Spec : Node_Id;
3452 Old_Disc : Entity_Id;
3453 New_Disc : Entity_Id;
3455 Constraint_Present : constant Boolean :=
3456 Nkind (Subtype_Indication (Type_Definition (N)))
3457 = N_Subtype_Indication;
3460 Set_Stored_Constraint (Derived_Type, No_Elist);
3462 if Is_Task_Type (Parent_Type) then
3463 Set_Storage_Size_Variable (Derived_Type,
3464 Storage_Size_Variable (Parent_Type));
3467 if Present (Discriminant_Specifications (N)) then
3468 New_Scope (Derived_Type);
3469 Check_Or_Process_Discriminants (N, Derived_Type);
3472 elsif Constraint_Present then
3474 -- Build constrained subtype and derive from it
3477 Loc : constant Source_Ptr := Sloc (N);
3478 Anon : constant Entity_Id :=
3479 Make_Defining_Identifier (Loc,
3480 New_External_Name (Chars (Derived_Type), 'T'));
3485 Make_Subtype_Declaration (Loc,
3486 Defining_Identifier => Anon,
3487 Subtype_Indication =>
3488 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
3489 Insert_Before (N, Decl);
3490 Rewrite (Subtype_Indication (Type_Definition (N)),
3491 New_Occurrence_Of (Anon, Loc));
3493 Set_Analyzed (Derived_Type, False);
3499 -- All attributes are inherited from parent. In particular,
3500 -- entries and the corresponding record type are the same.
3501 -- Discriminants may be renamed, and must be treated separately.
3503 Set_Has_Discriminants
3504 (Derived_Type, Has_Discriminants (Parent_Type));
3505 Set_Corresponding_Record_Type
3506 (Derived_Type, Corresponding_Record_Type (Parent_Type));
3508 if Constraint_Present then
3510 if not Has_Discriminants (Parent_Type) then
3511 Error_Msg_N ("untagged parent must have discriminants", N);
3513 elsif Present (Discriminant_Specifications (N)) then
3515 -- Verify that new discriminants are used to constrain
3518 Old_Disc := First_Discriminant (Parent_Type);
3519 New_Disc := First_Discriminant (Derived_Type);
3520 Disc_Spec := First (Discriminant_Specifications (N));
3524 (Constraint (Subtype_Indication (Type_Definition (N)))));
3526 while Present (Old_Disc) and then Present (Disc_Spec) loop
3528 if Nkind (Discriminant_Type (Disc_Spec)) /=
3531 Analyze (Discriminant_Type (Disc_Spec));
3533 if not Subtypes_Statically_Compatible (
3534 Etype (Discriminant_Type (Disc_Spec)),
3538 ("not statically compatible with parent discriminant",
3539 Discriminant_Type (Disc_Spec));
3543 if Nkind (D_Constraint) = N_Identifier
3544 and then Chars (D_Constraint) /=
3545 Chars (Defining_Identifier (Disc_Spec))
3547 Error_Msg_N ("new discriminants must constrain old ones",
3550 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
3553 Next_Discriminant (Old_Disc);
3554 Next_Discriminant (New_Disc);
3558 if Present (Old_Disc) or else Present (Disc_Spec) then
3559 Error_Msg_N ("discriminant mismatch in derivation", N);
3564 elsif Present (Discriminant_Specifications (N)) then
3566 ("missing discriminant constraint in untagged derivation",
3570 if Present (Discriminant_Specifications (N)) then
3572 Old_Disc := First_Discriminant (Parent_Type);
3574 while Present (Old_Disc) loop
3576 if No (Next_Entity (Old_Disc))
3577 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
3579 Set_Next_Entity (Last_Entity (Derived_Type),
3580 Next_Entity (Old_Disc));
3584 Next_Discriminant (Old_Disc);
3588 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
3589 if Has_Discriminants (Parent_Type) then
3590 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3591 Set_Discriminant_Constraint (
3592 Derived_Type, Discriminant_Constraint (Parent_Type));
3596 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
3598 Set_Has_Completion (Derived_Type);
3599 end Build_Derived_Concurrent_Type;
3601 ------------------------------------
3602 -- Build_Derived_Enumeration_Type --
3603 ------------------------------------
3605 procedure Build_Derived_Enumeration_Type
3607 Parent_Type : Entity_Id;
3608 Derived_Type : Entity_Id)
3610 Loc : constant Source_Ptr := Sloc (N);
3611 Def : constant Node_Id := Type_Definition (N);
3612 Indic : constant Node_Id := Subtype_Indication (Def);
3613 Implicit_Base : Entity_Id;
3614 Literal : Entity_Id;
3615 New_Lit : Entity_Id;
3616 Literals_List : List_Id;
3617 Type_Decl : Node_Id;
3619 Rang_Expr : Node_Id;
3622 -- Since types Standard.Character and Standard.Wide_Character do
3623 -- not have explicit literals lists we need to process types derived
3624 -- from them specially. This is handled by Derived_Standard_Character.
3625 -- If the parent type is a generic type, there are no literals either,
3626 -- and we construct the same skeletal representation as for the generic
3629 if Root_Type (Parent_Type) = Standard_Character
3630 or else Root_Type (Parent_Type) = Standard_Wide_Character
3632 Derived_Standard_Character (N, Parent_Type, Derived_Type);
3634 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
3641 Make_Attribute_Reference (Loc,
3642 Attribute_Name => Name_First,
3643 Prefix => New_Reference_To (Derived_Type, Loc));
3644 Set_Etype (Lo, Derived_Type);
3647 Make_Attribute_Reference (Loc,
3648 Attribute_Name => Name_Last,
3649 Prefix => New_Reference_To (Derived_Type, Loc));
3650 Set_Etype (Hi, Derived_Type);
3652 Set_Scalar_Range (Derived_Type,
3659 -- If a constraint is present, analyze the bounds to catch
3660 -- premature usage of the derived literals.
3662 if Nkind (Indic) = N_Subtype_Indication
3663 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
3665 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
3666 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
3669 -- Introduce an implicit base type for the derived type even
3670 -- if there is no constraint attached to it, since this seems
3671 -- closer to the Ada semantics. Build a full type declaration
3672 -- tree for the derived type using the implicit base type as
3673 -- the defining identifier. The build a subtype declaration
3674 -- tree which applies the constraint (if any) have it replace
3675 -- the derived type declaration.
3677 Literal := First_Literal (Parent_Type);
3678 Literals_List := New_List;
3680 while Present (Literal)
3681 and then Ekind (Literal) = E_Enumeration_Literal
3683 -- Literals of the derived type have the same representation as
3684 -- those of the parent type, but this representation can be
3685 -- overridden by an explicit representation clause. Indicate
3686 -- that there is no explicit representation given yet. These
3687 -- derived literals are implicit operations of the new type,
3688 -- and can be overriden by explicit ones.
3690 if Nkind (Literal) = N_Defining_Character_Literal then
3692 Make_Defining_Character_Literal (Loc, Chars (Literal));
3694 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
3697 Set_Ekind (New_Lit, E_Enumeration_Literal);
3698 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
3699 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
3700 Set_Enumeration_Rep_Expr (New_Lit, Empty);
3701 Set_Alias (New_Lit, Literal);
3702 Set_Is_Known_Valid (New_Lit, True);
3704 Append (New_Lit, Literals_List);
3705 Next_Literal (Literal);
3709 Make_Defining_Identifier (Sloc (Derived_Type),
3710 New_External_Name (Chars (Derived_Type), 'B'));
3712 -- Indicate the proper nature of the derived type. This must
3713 -- be done before analysis of the literals, to recognize cases
3714 -- when a literal may be hidden by a previous explicit function
3715 -- definition (cf. c83031a).
3717 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
3718 Set_Etype (Derived_Type, Implicit_Base);
3721 Make_Full_Type_Declaration (Loc,
3722 Defining_Identifier => Implicit_Base,
3723 Discriminant_Specifications => No_List,
3725 Make_Enumeration_Type_Definition (Loc, Literals_List));
3727 Mark_Rewrite_Insertion (Type_Decl);
3728 Insert_Before (N, Type_Decl);
3729 Analyze (Type_Decl);
3731 -- After the implicit base is analyzed its Etype needs to be
3732 -- changed to reflect the fact that it is derived from the
3733 -- parent type which was ignored during analysis. We also set
3734 -- the size at this point.
3736 Set_Etype (Implicit_Base, Parent_Type);
3738 Set_Size_Info (Implicit_Base, Parent_Type);
3739 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
3740 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
3742 Set_Has_Non_Standard_Rep
3743 (Implicit_Base, Has_Non_Standard_Rep
3745 Set_Has_Delayed_Freeze (Implicit_Base);
3747 -- Process the subtype indication including a validation check
3748 -- on the constraint, if any. If a constraint is given, its bounds
3749 -- must be implicitly converted to the new type.
3751 if Nkind (Indic) = N_Subtype_Indication then
3754 R : constant Node_Id :=
3755 Range_Expression (Constraint (Indic));
3758 if Nkind (R) = N_Range then
3759 Hi := Build_Scalar_Bound
3760 (High_Bound (R), Parent_Type, Implicit_Base);
3761 Lo := Build_Scalar_Bound
3762 (Low_Bound (R), Parent_Type, Implicit_Base);
3765 -- Constraint is a Range attribute. Replace with the
3766 -- explicit mention of the bounds of the prefix, which
3767 -- must be a subtype.
3769 Analyze (Prefix (R));
3771 Convert_To (Implicit_Base,
3772 Make_Attribute_Reference (Loc,
3773 Attribute_Name => Name_Last,
3775 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3778 Convert_To (Implicit_Base,
3779 Make_Attribute_Reference (Loc,
3780 Attribute_Name => Name_First,
3782 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3790 (Type_High_Bound (Parent_Type),
3791 Parent_Type, Implicit_Base);
3794 (Type_Low_Bound (Parent_Type),
3795 Parent_Type, Implicit_Base);
3803 -- If we constructed a default range for the case where no range
3804 -- was given, then the expressions in the range must not freeze
3805 -- since they do not correspond to expressions in the source.
3807 if Nkind (Indic) /= N_Subtype_Indication then
3808 Set_Must_Not_Freeze (Lo);
3809 Set_Must_Not_Freeze (Hi);
3810 Set_Must_Not_Freeze (Rang_Expr);
3814 Make_Subtype_Declaration (Loc,
3815 Defining_Identifier => Derived_Type,
3816 Subtype_Indication =>
3817 Make_Subtype_Indication (Loc,
3818 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
3820 Make_Range_Constraint (Loc,
3821 Range_Expression => Rang_Expr))));
3825 -- If pragma Discard_Names applies on the first subtype
3826 -- of the parent type, then it must be applied on this
3829 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
3830 Set_Discard_Names (Derived_Type);
3833 -- Apply a range check. Since this range expression doesn't
3834 -- have an Etype, we have to specifically pass the Source_Typ
3835 -- parameter. Is this right???
3837 if Nkind (Indic) = N_Subtype_Indication then
3838 Apply_Range_Check (Range_Expression (Constraint (Indic)),
3840 Source_Typ => Entity (Subtype_Mark (Indic)));
3843 end Build_Derived_Enumeration_Type;
3845 --------------------------------
3846 -- Build_Derived_Numeric_Type --
3847 --------------------------------
3849 procedure Build_Derived_Numeric_Type
3851 Parent_Type : Entity_Id;
3852 Derived_Type : Entity_Id)
3854 Loc : constant Source_Ptr := Sloc (N);
3855 Tdef : constant Node_Id := Type_Definition (N);
3856 Indic : constant Node_Id := Subtype_Indication (Tdef);
3857 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3858 No_Constraint : constant Boolean := Nkind (Indic) /=
3859 N_Subtype_Indication;
3860 Implicit_Base : Entity_Id;
3866 -- Process the subtype indication including a validation check on
3867 -- the constraint if any.
3869 Discard_Node (Process_Subtype (Indic, N));
3871 -- Introduce an implicit base type for the derived type even if
3872 -- there is no constraint attached to it, since this seems closer
3873 -- to the Ada semantics.
3876 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3878 Set_Etype (Implicit_Base, Parent_Base);
3879 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3880 Set_Size_Info (Implicit_Base, Parent_Base);
3881 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3882 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
3883 Set_Parent (Implicit_Base, Parent (Derived_Type));
3885 if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
3886 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3889 Set_Has_Delayed_Freeze (Implicit_Base);
3891 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
3892 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
3894 Set_Scalar_Range (Implicit_Base,
3899 if Has_Infinities (Parent_Base) then
3900 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
3903 -- The Derived_Type, which is the entity of the declaration, is
3904 -- a subtype of the implicit base. Its Ekind is a subtype, even
3905 -- in the absence of an explicit constraint.
3907 Set_Etype (Derived_Type, Implicit_Base);
3909 -- If we did not have a constraint, then the Ekind is set from the
3910 -- parent type (otherwise Process_Subtype has set the bounds)
3912 if No_Constraint then
3913 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
3916 -- If we did not have a range constraint, then set the range
3917 -- from the parent type. Otherwise, the call to Process_Subtype
3918 -- has set the bounds.
3921 or else not Has_Range_Constraint (Indic)
3923 Set_Scalar_Range (Derived_Type,
3925 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
3926 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
3927 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3929 if Has_Infinities (Parent_Type) then
3930 Set_Includes_Infinities (Scalar_Range (Derived_Type));
3934 -- Set remaining type-specific fields, depending on numeric type
3936 if Is_Modular_Integer_Type (Parent_Type) then
3937 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
3939 Set_Non_Binary_Modulus
3940 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
3942 elsif Is_Floating_Point_Type (Parent_Type) then
3944 -- Digits of base type is always copied from the digits value of
3945 -- the parent base type, but the digits of the derived type will
3946 -- already have been set if there was a constraint present.
3948 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3949 Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
3951 if No_Constraint then
3952 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
3955 elsif Is_Fixed_Point_Type (Parent_Type) then
3957 -- Small of base type and derived type are always copied from
3958 -- the parent base type, since smalls never change. The delta
3959 -- of the base type is also copied from the parent base type.
3960 -- However the delta of the derived type will have been set
3961 -- already if a constraint was present.
3963 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
3964 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
3965 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
3967 if No_Constraint then
3968 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
3971 -- The scale and machine radix in the decimal case are always
3972 -- copied from the parent base type.
3974 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
3975 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
3976 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
3978 Set_Machine_Radix_10
3979 (Derived_Type, Machine_Radix_10 (Parent_Base));
3980 Set_Machine_Radix_10
3981 (Implicit_Base, Machine_Radix_10 (Parent_Base));
3983 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3985 if No_Constraint then
3986 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
3989 -- the analysis of the subtype_indication sets the
3990 -- digits value of the derived type.
3997 -- The type of the bounds is that of the parent type, and they
3998 -- must be converted to the derived type.
4000 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
4002 -- The implicit_base should be frozen when the derived type is frozen,
4003 -- but note that it is used in the conversions of the bounds. For
4004 -- fixed types we delay the determination of the bounds until the proper
4005 -- freezing point. For other numeric types this is rejected by GCC, for
4006 -- reasons that are currently unclear (???), so we choose to freeze the
4007 -- implicit base now. In the case of integers and floating point types
4008 -- this is harmless because subsequent representation clauses cannot
4009 -- affect anything, but it is still baffling that we cannot use the
4010 -- same mechanism for all derived numeric types.
4012 if Is_Fixed_Point_Type (Parent_Type) then
4013 Conditional_Delay (Implicit_Base, Parent_Type);
4015 Freeze_Before (N, Implicit_Base);
4017 end Build_Derived_Numeric_Type;
4019 --------------------------------
4020 -- Build_Derived_Private_Type --
4021 --------------------------------
4023 procedure Build_Derived_Private_Type
4025 Parent_Type : Entity_Id;
4026 Derived_Type : Entity_Id;
4027 Is_Completion : Boolean;
4028 Derive_Subps : Boolean := True)
4030 Der_Base : Entity_Id;
4032 Full_Decl : Node_Id := Empty;
4033 Full_Der : Entity_Id;
4035 Last_Discr : Entity_Id;
4036 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
4037 Swapped : Boolean := False;
4039 procedure Copy_And_Build;
4040 -- Copy derived type declaration, replace parent with its full view,
4041 -- and analyze new declaration.
4043 --------------------
4044 -- Copy_And_Build --
4045 --------------------
4047 procedure Copy_And_Build is
4051 if Ekind (Parent_Type) in Record_Kind
4052 or else (Ekind (Parent_Type) in Enumeration_Kind
4053 and then Root_Type (Parent_Type) /= Standard_Character
4054 and then Root_Type (Parent_Type) /= Standard_Wide_Character
4055 and then not Is_Generic_Type (Root_Type (Parent_Type)))
4057 Full_N := New_Copy_Tree (N);
4058 Insert_After (N, Full_N);
4059 Build_Derived_Type (
4060 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
4063 Build_Derived_Type (
4064 N, Parent_Type, Full_Der, True, Derive_Subps => False);
4068 -- Start of processing for Build_Derived_Private_Type
4071 if Is_Tagged_Type (Parent_Type) then
4072 Build_Derived_Record_Type
4073 (N, Parent_Type, Derived_Type, Derive_Subps);
4076 elsif Has_Discriminants (Parent_Type) then
4078 if Present (Full_View (Parent_Type)) then
4079 if not Is_Completion then
4081 -- Copy declaration for subsequent analysis, to
4082 -- provide a completion for what is a private
4083 -- declaration. Indicate that the full type is
4084 -- internally generated.
4086 Full_Decl := New_Copy_Tree (N);
4087 Full_Der := New_Copy (Derived_Type);
4088 Set_Comes_From_Source (Full_Decl, False);
4090 Insert_After (N, Full_Decl);
4093 -- If this is a completion, the full view being built is
4094 -- itself private. We build a subtype of the parent with
4095 -- the same constraints as this full view, to convey to the
4096 -- back end the constrained components and the size of this
4097 -- subtype. If the parent is constrained, its full view can
4098 -- serve as the underlying full view of the derived type.
4100 if No (Discriminant_Specifications (N)) then
4102 if Nkind (Subtype_Indication (Type_Definition (N)))
4103 = N_Subtype_Indication
4105 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
4107 elsif Is_Constrained (Full_View (Parent_Type)) then
4108 Set_Underlying_Full_View (Derived_Type,
4109 Full_View (Parent_Type));
4113 -- If there are new discriminants, the parent subtype is
4114 -- constrained by them, but it is not clear how to build
4115 -- the underlying_full_view in this case ???
4122 -- Build partial view of derived type from partial view of parent.
4124 Build_Derived_Record_Type
4125 (N, Parent_Type, Derived_Type, Derive_Subps);
4127 if Present (Full_View (Parent_Type))
4128 and then not Is_Completion
4130 if not In_Open_Scopes (Par_Scope)
4131 or else not In_Same_Source_Unit (N, Parent_Type)
4133 -- Swap partial and full views temporarily
4135 Install_Private_Declarations (Par_Scope);
4136 Install_Visible_Declarations (Par_Scope);
4140 -- Build full view of derived type from full view of
4141 -- parent which is now installed.
4142 -- Subprograms have been derived on the partial view,
4143 -- the completion does not derive them anew.
4145 if not Is_Tagged_Type (Parent_Type) then
4146 Build_Derived_Record_Type
4147 (Full_Decl, Parent_Type, Full_Der, False);
4150 -- If full view of parent is tagged, the completion
4151 -- inherits the proper primitive operations.
4153 Set_Defining_Identifier (Full_Decl, Full_Der);
4154 Build_Derived_Record_Type
4155 (Full_Decl, Parent_Type, Full_Der, Derive_Subps);
4156 Set_Analyzed (Full_Decl);
4160 Uninstall_Declarations (Par_Scope);
4162 if In_Open_Scopes (Par_Scope) then
4163 Install_Visible_Declarations (Par_Scope);
4167 Der_Base := Base_Type (Derived_Type);
4168 Set_Full_View (Derived_Type, Full_Der);
4169 Set_Full_View (Der_Base, Base_Type (Full_Der));
4171 -- Copy the discriminant list from full view to
4172 -- the partial views (base type and its subtype).
4173 -- Gigi requires that the partial and full views
4174 -- have the same discriminants.
4175 -- ??? Note that since the partial view is pointing
4176 -- to discriminants in the full view, their scope
4177 -- will be that of the full view. This might
4178 -- cause some front end problems and need
4181 Discr := First_Discriminant (Base_Type (Full_Der));
4182 Set_First_Entity (Der_Base, Discr);
4185 Last_Discr := Discr;
4186 Next_Discriminant (Discr);
4187 exit when No (Discr);
4190 Set_Last_Entity (Der_Base, Last_Discr);
4192 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
4193 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
4194 Set_Stored_Constraint (Full_Der, Stored_Constraint (Derived_Type));
4197 -- If this is a completion, the derived type stays private
4198 -- and there is no need to create a further full view, except
4199 -- in the unusual case when the derivation is nested within a
4200 -- child unit, see below.
4205 elsif Present (Full_View (Parent_Type))
4206 and then Has_Discriminants (Full_View (Parent_Type))
4208 if Has_Unknown_Discriminants (Parent_Type)
4209 and then Nkind (Subtype_Indication (Type_Definition (N)))
4210 = N_Subtype_Indication
4213 ("cannot constrain type with unknown discriminants",
4214 Subtype_Indication (Type_Definition (N)));
4218 -- If full view of parent is a record type, Build full view as
4219 -- a derivation from the parent's full view. Partial view remains
4220 -- private. For code generation and linking, the full view must
4221 -- have the same public status as the partial one. This full view
4222 -- is only needed if the parent type is in an enclosing scope, so
4223 -- that the full view may actually become visible, e.g. in a child
4224 -- unit. This is both more efficient, and avoids order of freezing
4225 -- problems with the added entities.
4227 if not Is_Private_Type (Full_View (Parent_Type))
4228 and then (In_Open_Scopes (Scope (Parent_Type)))
4230 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
4231 Chars (Derived_Type));
4232 Set_Is_Itype (Full_Der);
4233 Set_Has_Private_Declaration (Full_Der);
4234 Set_Has_Private_Declaration (Derived_Type);
4235 Set_Associated_Node_For_Itype (Full_Der, N);
4236 Set_Parent (Full_Der, Parent (Derived_Type));
4237 Set_Full_View (Derived_Type, Full_Der);
4238 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
4239 Full_P := Full_View (Parent_Type);
4240 Exchange_Declarations (Parent_Type);
4242 Exchange_Declarations (Full_P);
4245 Build_Derived_Record_Type
4246 (N, Full_View (Parent_Type), Derived_Type,
4247 Derive_Subps => False);
4250 -- In any case, the primitive operations are inherited from
4251 -- the parent type, not from the internal full view.
4253 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
4255 if Derive_Subps then
4256 Derive_Subprograms (Parent_Type, Derived_Type);
4260 -- Untagged type, No discriminants on either view
4262 if Nkind (Subtype_Indication (Type_Definition (N)))
4263 = N_Subtype_Indication
4266 ("illegal constraint on type without discriminants", N);
4269 if Present (Discriminant_Specifications (N))
4270 and then Present (Full_View (Parent_Type))
4271 and then not Is_Tagged_Type (Full_View (Parent_Type))
4274 ("cannot add discriminants to untagged type", N);
4277 Set_Stored_Constraint (Derived_Type, No_Elist);
4278 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
4279 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
4280 Set_Has_Controlled_Component
4281 (Derived_Type, Has_Controlled_Component
4284 -- Direct controlled types do not inherit Finalize_Storage_Only flag
4286 if not Is_Controlled (Parent_Type) then
4287 Set_Finalize_Storage_Only
4288 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
4291 -- Construct the implicit full view by deriving from full
4292 -- view of the parent type. In order to get proper visibility,
4293 -- we install the parent scope and its declarations.
4295 -- ??? if the parent is untagged private and its
4296 -- completion is tagged, this mechanism will not
4297 -- work because we cannot derive from the tagged
4298 -- full view unless we have an extension
4300 if Present (Full_View (Parent_Type))
4301 and then not Is_Tagged_Type (Full_View (Parent_Type))
4302 and then not Is_Completion
4304 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
4305 Chars (Derived_Type));
4306 Set_Is_Itype (Full_Der);
4307 Set_Has_Private_Declaration (Full_Der);
4308 Set_Has_Private_Declaration (Derived_Type);
4309 Set_Associated_Node_For_Itype (Full_Der, N);
4310 Set_Parent (Full_Der, Parent (Derived_Type));
4311 Set_Full_View (Derived_Type, Full_Der);
4313 if not In_Open_Scopes (Par_Scope) then
4314 Install_Private_Declarations (Par_Scope);
4315 Install_Visible_Declarations (Par_Scope);
4317 Uninstall_Declarations (Par_Scope);
4319 -- If parent scope is open and in another unit, and
4320 -- parent has a completion, then the derivation is taking
4321 -- place in the visible part of a child unit. In that
4322 -- case retrieve the full view of the parent momentarily.
4324 elsif not In_Same_Source_Unit (N, Parent_Type) then
4325 Full_P := Full_View (Parent_Type);
4326 Exchange_Declarations (Parent_Type);
4328 Exchange_Declarations (Full_P);
4330 -- Otherwise it is a local derivation.
4336 Set_Scope (Full_Der, Current_Scope);
4337 Set_Is_First_Subtype (Full_Der,
4338 Is_First_Subtype (Derived_Type));
4339 Set_Has_Size_Clause (Full_Der, False);
4340 Set_Has_Alignment_Clause (Full_Der, False);
4341 Set_Next_Entity (Full_Der, Empty);
4342 Set_Has_Delayed_Freeze (Full_Der);
4343 Set_Is_Frozen (Full_Der, False);
4344 Set_Freeze_Node (Full_Der, Empty);
4345 Set_Depends_On_Private (Full_Der,
4346 Has_Private_Component (Full_Der));
4347 Set_Public_Status (Full_Der);
4351 Set_Has_Unknown_Discriminants (Derived_Type,
4352 Has_Unknown_Discriminants (Parent_Type));
4354 if Is_Private_Type (Derived_Type) then
4355 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4358 if Is_Private_Type (Parent_Type)
4359 and then Base_Type (Parent_Type) = Parent_Type
4360 and then In_Open_Scopes (Scope (Parent_Type))
4362 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
4364 if Is_Child_Unit (Scope (Current_Scope))
4365 and then Is_Completion
4366 and then In_Private_Part (Current_Scope)
4367 and then Scope (Parent_Type) /= Current_Scope
4369 -- This is the unusual case where a type completed by a private
4370 -- derivation occurs within a package nested in a child unit,
4371 -- and the parent is declared in an ancestor. In this case, the
4372 -- full view of the parent type will become visible in the body
4373 -- of the enclosing child, and only then will the current type
4374 -- be possibly non-private. We build a underlying full view that
4375 -- will be installed when the enclosing child body is compiled.
4378 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
4382 Make_Defining_Identifier (Sloc (Derived_Type),
4383 Chars (Derived_Type));
4384 Set_Is_Itype (Full_Der);
4385 Set_Itype (IR, Full_Der);
4386 Insert_After (N, IR);
4388 -- The full view will be used to swap entities on entry/exit
4389 -- to the body, and must appear in the entity list for the
4392 Append_Entity (Full_Der, Scope (Derived_Type));
4393 Set_Has_Private_Declaration (Full_Der);
4394 Set_Has_Private_Declaration (Derived_Type);
4395 Set_Associated_Node_For_Itype (Full_Der, N);
4396 Set_Parent (Full_Der, Parent (Derived_Type));
4397 Full_P := Full_View (Parent_Type);
4398 Exchange_Declarations (Parent_Type);
4400 Exchange_Declarations (Full_P);
4401 Set_Underlying_Full_View (Derived_Type, Full_Der);
4405 end Build_Derived_Private_Type;
4407 -------------------------------
4408 -- Build_Derived_Record_Type --
4409 -------------------------------
4413 -- Ideally we would like to use the same model of type derivation for
4414 -- tagged and untagged record types. Unfortunately this is not quite
4415 -- possible because the semantics of representation clauses is different
4416 -- for tagged and untagged records under inheritance. Consider the
4419 -- type R (...) is [tagged] record ... end record;
4420 -- type T (...) is new R (...) [with ...];
4422 -- The representation clauses of T can specify a completely different
4423 -- record layout from R's. Hence the same component can be placed in
4424 -- two very different positions in objects of type T and R. If R and T
4425 -- are tagged types, representation clauses for T can only specify the
4426 -- layout of non inherited components, thus components that are common
4427 -- in R and T have the same position in objects of type R and T.
4429 -- This has two implications. The first is that the entire tree for R's
4430 -- declaration needs to be copied for T in the untagged case, so that
4431 -- T can be viewed as a record type of its own with its own representation
4432 -- clauses. The second implication is the way we handle discriminants.
4433 -- Specifically, in the untagged case we need a way to communicate to Gigi
4434 -- what are the real discriminants in the record, while for the semantics
4435 -- we need to consider those introduced by the user to rename the
4436 -- discriminants in the parent type. This is handled by introducing the
4437 -- notion of stored discriminants. See below for more.
4439 -- Fortunately the way regular components are inherited can be handled in
4440 -- the same way in tagged and untagged types.
4442 -- To complicate things a bit more the private view of a private extension
4443 -- cannot be handled in the same way as the full view (for one thing the
4444 -- semantic rules are somewhat different). We will explain what differs
4447 -- 2. DISCRIMINANTS UNDER INHERITANCE.
4449 -- The semantic rules governing the discriminants of derived types are
4452 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
4453 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
4455 -- If parent type has discriminants, then the discriminants that are
4456 -- declared in the derived type are [3.4 (11)]:
4458 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
4461 -- o Otherwise, each discriminant of the parent type (implicitly
4462 -- declared in the same order with the same specifications). In this
4463 -- case, the discriminants are said to be "inherited", or if unknown in
4464 -- the parent are also unknown in the derived type.
4466 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
4468 -- o The parent subtype shall be constrained;
4470 -- o If the parent type is not a tagged type, then each discriminant of
4471 -- the derived type shall be used in the constraint defining a parent
4472 -- subtype [Implementation note: this ensures that the new discriminant
4473 -- can share storage with an existing discriminant.].
4475 -- For the derived type each discriminant of the parent type is either
4476 -- inherited, constrained to equal some new discriminant of the derived
4477 -- type, or constrained to the value of an expression.
4479 -- When inherited or constrained to equal some new discriminant, the
4480 -- parent discriminant and the discriminant of the derived type are said
4483 -- If a discriminant of the parent type is constrained to a specific value
4484 -- in the derived type definition, then the discriminant is said to be
4485 -- "specified" by that derived type definition.
4487 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
4489 -- We have spoken about stored discriminants in point 1 (introduction)
4490 -- above. There are two sort of stored discriminants: implicit and
4491 -- explicit. As long as the derived type inherits the same discriminants as
4492 -- the root record type, stored discriminants are the same as regular
4493 -- discriminants, and are said to be implicit. However, if any discriminant
4494 -- in the root type was renamed in the derived type, then the derived
4495 -- type will contain explicit stored discriminants. Explicit stored
4496 -- discriminants are discriminants in addition to the semantically visible
4497 -- discriminants defined for the derived type. Stored discriminants are
4498 -- used by Gigi to figure out what are the physical discriminants in
4499 -- objects of the derived type (see precise definition in einfo.ads).
4500 -- As an example, consider the following:
4502 -- type R (D1, D2, D3 : Int) is record ... end record;
4503 -- type T1 is new R;
4504 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
4505 -- type T3 is new T2;
4506 -- type T4 (Y : Int) is new T3 (Y, 99);
4508 -- The following table summarizes the discriminants and stored
4509 -- discriminants in R and T1 through T4.
4511 -- Type Discrim Stored Discrim Comment
4512 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
4513 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
4514 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
4515 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
4516 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
4518 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to
4519 -- find the corresponding discriminant in the parent type, while
4520 -- Original_Record_Component (abbreviated ORC below), the actual physical
4521 -- component that is renamed. Finally the field Is_Completely_Hidden
4522 -- (abbreviated ICH below) is set for all explicit stored discriminants
4523 -- (see einfo.ads for more info). For the above example this gives:
4525 -- Discrim CD ORC ICH
4526 -- ^^^^^^^ ^^ ^^^ ^^^
4527 -- D1 in R empty itself no
4528 -- D2 in R empty itself no
4529 -- D3 in R empty itself no
4531 -- D1 in T1 D1 in R itself no
4532 -- D2 in T1 D2 in R itself no
4533 -- D3 in T1 D3 in R itself no
4535 -- X1 in T2 D3 in T1 D3 in T2 no
4536 -- X2 in T2 D1 in T1 D1 in T2 no
4537 -- D1 in T2 empty itself yes
4538 -- D2 in T2 empty itself yes
4539 -- D3 in T2 empty itself yes
4541 -- X1 in T3 X1 in T2 D3 in T3 no
4542 -- X2 in T3 X2 in T2 D1 in T3 no
4543 -- D1 in T3 empty itself yes
4544 -- D2 in T3 empty itself yes
4545 -- D3 in T3 empty itself yes
4547 -- Y in T4 X1 in T3 D3 in T3 no
4548 -- D1 in T3 empty itself yes
4549 -- D2 in T3 empty itself yes
4550 -- D3 in T3 empty itself yes
4552 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
4554 -- Type derivation for tagged types is fairly straightforward. if no
4555 -- discriminants are specified by the derived type, these are inherited
4556 -- from the parent. No explicit stored discriminants are ever necessary.
4557 -- The only manipulation that is done to the tree is that of adding a
4558 -- _parent field with parent type and constrained to the same constraint
4559 -- specified for the parent in the derived type definition. For instance:
4561 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
4562 -- type T1 is new R with null record;
4563 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
4565 -- are changed into :
4567 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
4568 -- _parent : R (D1, D2, D3);
4571 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
4572 -- _parent : T1 (X2, 88, X1);
4575 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4576 -- ORC and ICH fields are:
4578 -- Discrim CD ORC ICH
4579 -- ^^^^^^^ ^^ ^^^ ^^^
4580 -- D1 in R empty itself no
4581 -- D2 in R empty itself no
4582 -- D3 in R empty itself no
4584 -- D1 in T1 D1 in R D1 in R no
4585 -- D2 in T1 D2 in R D2 in R no
4586 -- D3 in T1 D3 in R D3 in R no
4588 -- X1 in T2 D3 in T1 D3 in R no
4589 -- X2 in T2 D1 in T1 D1 in R no
4591 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
4593 -- Regardless of whether we dealing with a tagged or untagged type
4594 -- we will transform all derived type declarations of the form
4596 -- type T is new R (...) [with ...];
4598 -- subtype S is R (...);
4599 -- type T is new S [with ...];
4601 -- type BT is new R [with ...];
4602 -- subtype T is BT (...);
4604 -- That is, the base derived type is constrained only if it has no
4605 -- discriminants. The reason for doing this is that GNAT's semantic model
4606 -- assumes that a base type with discriminants is unconstrained.
4608 -- Note that, strictly speaking, the above transformation is not always
4609 -- correct. Consider for instance the following excerpt from ACVC b34011a:
4611 -- procedure B34011A is
4612 -- type REC (D : integer := 0) is record
4617 -- type T6 is new Rec;
4618 -- function F return T6;
4623 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4626 -- The definition of Q6.U is illegal. However transforming Q6.U into
4628 -- type BaseU is new T6;
4629 -- subtype U is BaseU (Q6.F.I)
4631 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4632 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4633 -- the transformation described above.
4635 -- There is another instance where the above transformation is incorrect.
4639 -- type Base (D : Integer) is tagged null record;
4640 -- procedure P (X : Base);
4642 -- type Der is new Base (2) with null record;
4643 -- procedure P (X : Der);
4646 -- Then the above transformation turns this into
4648 -- type Der_Base is new Base with null record;
4649 -- -- procedure P (X : Base) is implicitly inherited here
4650 -- -- as procedure P (X : Der_Base).
4652 -- subtype Der is Der_Base (2);
4653 -- procedure P (X : Der);
4654 -- -- The overriding of P (X : Der_Base) is illegal since we
4655 -- -- have a parameter conformance problem.
4657 -- To get around this problem, after having semantically processed Der_Base
4658 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4659 -- Discriminant_Constraint from Der so that when parameter conformance is
4660 -- checked when P is overridden, no semantic errors are flagged.
4662 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
4664 -- Regardless of whether we are dealing with a tagged or untagged type
4665 -- we will transform all derived type declarations of the form
4667 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4668 -- type T is new R [with ...];
4670 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4672 -- The reason for such transformation is that it allows us to implement a
4673 -- very clean form of component inheritance as explained below.
4675 -- Note that this transformation is not achieved by direct tree rewriting
4676 -- and manipulation, but rather by redoing the semantic actions that the
4677 -- above transformation will entail. This is done directly in routine
4678 -- Inherit_Components.
4680 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
4682 -- In both tagged and untagged derived types, regular non discriminant
4683 -- components are inherited in the derived type from the parent type. In
4684 -- the absence of discriminants component, inheritance is straightforward
4685 -- as components can simply be copied from the parent.
4686 -- If the parent has discriminants, inheriting components constrained with
4687 -- these discriminants requires caution. Consider the following example:
4689 -- type R (D1, D2 : Positive) is [tagged] record
4690 -- S : String (D1 .. D2);
4693 -- type T1 is new R [with null record];
4694 -- type T2 (X : positive) is new R (1, X) [with null record];
4696 -- As explained in 6. above, T1 is rewritten as
4698 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4700 -- which makes the treatment for T1 and T2 identical.
4702 -- What we want when inheriting S, is that references to D1 and D2 in R are
4703 -- replaced with references to their correct constraints, ie D1 and D2 in
4704 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4705 -- with either discriminant references in the derived type or expressions.
4706 -- This replacement is achieved as follows: before inheriting R's
4707 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4708 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4709 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4710 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4711 -- by String (1 .. X).
4713 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
4715 -- We explain here the rules governing private type extensions relevant to
4716 -- type derivation. These rules are explained on the following example:
4718 -- type D [(...)] is new A [(...)] with private; <-- partial view
4719 -- type D [(...)] is new P [(...)] with null record; <-- full view
4721 -- Type A is called the ancestor subtype of the private extension.
4722 -- Type P is the parent type of the full view of the private extension. It
4723 -- must be A or a type derived from A.
4725 -- The rules concerning the discriminants of private type extensions are
4728 -- o If a private extension inherits known discriminants from the ancestor
4729 -- subtype, then the full view shall also inherit its discriminants from
4730 -- the ancestor subtype and the parent subtype of the full view shall be
4731 -- constrained if and only if the ancestor subtype is constrained.
4733 -- o If a partial view has unknown discriminants, then the full view may
4734 -- define a definite or an indefinite subtype, with or without
4737 -- o If a partial view has neither known nor unknown discriminants, then
4738 -- the full view shall define a definite subtype.
4740 -- o If the ancestor subtype of a private extension has constrained
4741 -- discriminants, then the parent subtype of the full view shall impose a
4742 -- statically matching constraint on those discriminants.
4744 -- This means that only the following forms of private extensions are
4747 -- type D is new A with private; <-- partial view
4748 -- type D is new P with null record; <-- full view
4750 -- If A has no discriminants than P has no discriminants, otherwise P must
4751 -- inherit A's discriminants.
4753 -- type D is new A (...) with private; <-- partial view
4754 -- type D is new P (:::) with null record; <-- full view
4756 -- P must inherit A's discriminants and (...) and (:::) must statically
4759 -- subtype A is R (...);
4760 -- type D is new A with private; <-- partial view
4761 -- type D is new P with null record; <-- full view
4763 -- P must have inherited R's discriminants and must be derived from A or
4764 -- any of its subtypes.
4766 -- type D (..) is new A with private; <-- partial view
4767 -- type D (..) is new P [(:::)] with null record; <-- full view
4769 -- No specific constraints on P's discriminants or constraint (:::).
4770 -- Note that A can be unconstrained, but the parent subtype P must either
4771 -- be constrained or (:::) must be present.
4773 -- type D (..) is new A [(...)] with private; <-- partial view
4774 -- type D (..) is new P [(:::)] with null record; <-- full view
4776 -- P's constraints on A's discriminants must statically match those
4777 -- imposed by (...).
4779 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
4781 -- The full view of a private extension is handled exactly as described
4782 -- above. The model chose for the private view of a private extension
4783 -- is the same for what concerns discriminants (ie they receive the same
4784 -- treatment as in the tagged case). However, the private view of the
4785 -- private extension always inherits the components of the parent base,
4786 -- without replacing any discriminant reference. Strictly speaking this
4787 -- is incorrect. However, Gigi never uses this view to generate code so
4788 -- this is a purely semantic issue. In theory, a set of transformations
4789 -- similar to those given in 5. and 6. above could be applied to private
4790 -- views of private extensions to have the same model of component
4791 -- inheritance as for non private extensions. However, this is not done
4792 -- because it would further complicate private type processing.
4793 -- Semantically speaking, this leaves us in an uncomfortable
4794 -- situation. As an example consider:
4797 -- type R (D : integer) is tagged record
4798 -- S : String (1 .. D);
4800 -- procedure P (X : R);
4801 -- type T is new R (1) with private;
4803 -- type T is new R (1) with null record;
4806 -- This is transformed into:
4809 -- type R (D : integer) is tagged record
4810 -- S : String (1 .. D);
4812 -- procedure P (X : R);
4813 -- type T is new R (1) with private;
4815 -- type BaseT is new R with null record;
4816 -- subtype T is BaseT (1);
4819 -- (strictly speaking the above is incorrect Ada).
4821 -- From the semantic standpoint the private view of private extension T
4822 -- should be flagged as constrained since one can clearly have
4826 -- in a unit withing Pack. However, when deriving subprograms for the
4827 -- private view of private extension T, T must be seen as unconstrained
4828 -- since T has discriminants (this is a constraint of the current
4829 -- subprogram derivation model). Thus, when processing the private view of
4830 -- a private extension such as T, we first mark T as unconstrained, we
4831 -- process it, we perform program derivation and just before returning from
4832 -- Build_Derived_Record_Type we mark T as constrained.
4833 -- ??? Are there are other uncomfortable cases that we will have to
4836 -- 10. RECORD_TYPE_WITH_PRIVATE complications.
4838 -- Types that are derived from a visible record type and have a private
4839 -- extension present other peculiarities. They behave mostly like private
4840 -- types, but if they have primitive operations defined, these will not
4841 -- have the proper signatures for further inheritance, because other
4842 -- primitive operations will use the implicit base that we define for
4843 -- private derivations below. This affect subprogram inheritance (see
4844 -- Derive_Subprograms for details). We also derive the implicit base from
4845 -- the base type of the full view, so that the implicit base is a record
4846 -- type and not another private type, This avoids infinite loops.
4848 procedure Build_Derived_Record_Type
4850 Parent_Type : Entity_Id;
4851 Derived_Type : Entity_Id;
4852 Derive_Subps : Boolean := True)
4854 Loc : constant Source_Ptr := Sloc (N);
4855 Parent_Base : Entity_Id;
4860 Discrim : Entity_Id;
4861 Last_Discrim : Entity_Id;
4863 Discs : Elist_Id := New_Elmt_List;
4864 -- An empty Discs list means that there were no constraints in the
4865 -- subtype indication or that there was an error processing it.
4867 Assoc_List : Elist_Id;
4868 New_Discrs : Elist_Id;
4870 New_Base : Entity_Id;
4872 New_Indic : Node_Id;
4874 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4875 Discriminant_Specs : constant Boolean :=
4876 Present (Discriminant_Specifications (N));
4877 Private_Extension : constant Boolean :=
4878 (Nkind (N) = N_Private_Extension_Declaration);
4880 Constraint_Present : Boolean;
4881 Inherit_Discrims : Boolean := False;
4883 Save_Etype : Entity_Id;
4884 Save_Discr_Constr : Elist_Id;
4885 Save_Next_Entity : Entity_Id;
4888 if Ekind (Parent_Type) = E_Record_Type_With_Private
4889 and then Present (Full_View (Parent_Type))
4890 and then Has_Discriminants (Parent_Type)
4892 Parent_Base := Base_Type (Full_View (Parent_Type));
4894 Parent_Base := Base_Type (Parent_Type);
4897 -- Before we start the previously documented transformations, here is
4898 -- a little fix for size and alignment of tagged types. Normally when
4899 -- we derive type D from type P, we copy the size and alignment of P
4900 -- as the default for D, and in the absence of explicit representation
4901 -- clauses for D, the size and alignment are indeed the same as the
4904 -- But this is wrong for tagged types, since fields may be added,
4905 -- and the default size may need to be larger, and the default
4906 -- alignment may need to be larger.
4908 -- We therefore reset the size and alignment fields in the tagged
4909 -- case. Note that the size and alignment will in any case be at
4910 -- least as large as the parent type (since the derived type has
4911 -- a copy of the parent type in the _parent field)
4914 Init_Size_Align (Derived_Type);
4917 -- STEP 0a: figure out what kind of derived type declaration we have.
4919 if Private_Extension then
4921 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4924 Type_Def := Type_Definition (N);
4926 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4927 -- Parent_Base can be a private type or private extension. However,
4928 -- for tagged types with an extension the newly added fields are
4929 -- visible and hence the Derived_Type is always an E_Record_Type.
4930 -- (except that the parent may have its own private fields).
4931 -- For untagged types we preserve the Ekind of the Parent_Base.
4933 if Present (Record_Extension_Part (Type_Def)) then
4934 Set_Ekind (Derived_Type, E_Record_Type);
4936 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4940 -- Indic can either be an N_Identifier if the subtype indication
4941 -- contains no constraint or an N_Subtype_Indication if the subtype
4942 -- indication has a constraint.
4944 Indic := Subtype_Indication (Type_Def);
4945 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
4947 -- Check that the type has visible discriminants. The type may be
4948 -- a private type with unknown discriminants whose full view has
4949 -- discriminants which are invisible.
4951 if Constraint_Present then
4952 if not Has_Discriminants (Parent_Base)
4954 (Has_Unknown_Discriminants (Parent_Base)
4955 and then Is_Private_Type (Parent_Base))
4958 ("invalid constraint: type has no discriminant",
4959 Constraint (Indic));
4961 Constraint_Present := False;
4962 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4964 elsif Is_Constrained (Parent_Type) then
4966 ("invalid constraint: parent type is already constrained",
4967 Constraint (Indic));
4969 Constraint_Present := False;
4970 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4974 -- STEP 0b: If needed, apply transformation given in point 5. above.
4976 if not Private_Extension
4977 and then Has_Discriminants (Parent_Type)
4978 and then not Discriminant_Specs
4979 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
4981 -- First, we must analyze the constraint (see comment in point 5.).
4983 if Constraint_Present then
4984 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
4986 if Has_Discriminants (Derived_Type)
4987 and then Has_Private_Declaration (Derived_Type)
4988 and then Present (Discriminant_Constraint (Derived_Type))
4990 -- Verify that constraints of the full view conform to those
4991 -- given in partial view.
4997 C1 := First_Elmt (New_Discrs);
4998 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
5000 while Present (C1) and then Present (C2) loop
5002 Fully_Conformant_Expressions (Node (C1), Node (C2))
5005 "constraint not conformant to previous declaration",
5015 -- Insert and analyze the declaration for the unconstrained base type
5017 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
5020 Make_Full_Type_Declaration (Loc,
5021 Defining_Identifier => New_Base,
5023 Make_Derived_Type_Definition (Loc,
5024 Abstract_Present => Abstract_Present (Type_Def),
5025 Subtype_Indication =>
5026 New_Occurrence_Of (Parent_Base, Loc),
5027 Record_Extension_Part =>
5028 Relocate_Node (Record_Extension_Part (Type_Def))));
5030 Set_Parent (New_Decl, Parent (N));
5031 Mark_Rewrite_Insertion (New_Decl);
5032 Insert_Before (N, New_Decl);
5034 -- Note that this call passes False for the Derive_Subps
5035 -- parameter because subprogram derivation is deferred until
5036 -- after creating the subtype (see below).
5039 (New_Decl, Parent_Base, New_Base,
5040 Is_Completion => True, Derive_Subps => False);
5042 -- ??? This needs re-examination to determine whether the
5043 -- above call can simply be replaced by a call to Analyze.
5045 Set_Analyzed (New_Decl);
5047 -- Insert and analyze the declaration for the constrained subtype
5049 if Constraint_Present then
5051 Make_Subtype_Indication (Loc,
5052 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
5053 Constraint => Relocate_Node (Constraint (Indic)));
5057 Constr_List : constant List_Id := New_List;
5062 C := First_Elmt (Discriminant_Constraint (Parent_Type));
5063 while Present (C) loop
5066 -- It is safe here to call New_Copy_Tree since
5067 -- Force_Evaluation was called on each constraint in
5068 -- Build_Discriminant_Constraints.
5070 Append (New_Copy_Tree (Expr), To => Constr_List);
5076 Make_Subtype_Indication (Loc,
5077 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
5079 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
5084 Make_Subtype_Declaration (Loc,
5085 Defining_Identifier => Derived_Type,
5086 Subtype_Indication => New_Indic));
5090 -- Derivation of subprograms must be delayed until the
5091 -- full subtype has been established to ensure proper
5092 -- overriding of subprograms inherited by full types.
5093 -- If the derivations occurred as part of the call to
5094 -- Build_Derived_Type above, then the check for type
5095 -- conformance would fail because earlier primitive
5096 -- subprograms could still refer to the full type prior
5097 -- the change to the new subtype and hence wouldn't
5098 -- match the new base type created here.
5100 Derive_Subprograms (Parent_Type, Derived_Type);
5102 -- For tagged types the Discriminant_Constraint of the new base itype
5103 -- is inherited from the first subtype so that no subtype conformance
5104 -- problem arise when the first subtype overrides primitive
5105 -- operations inherited by the implicit base type.
5108 Set_Discriminant_Constraint
5109 (New_Base, Discriminant_Constraint (Derived_Type));
5115 -- If we get here Derived_Type will have no discriminants or it will be
5116 -- a discriminated unconstrained base type.
5118 -- STEP 1a: perform preliminary actions/checks for derived tagged types
5121 -- The parent type is frozen for non-private extensions (RM 13.14(7))
5123 if not Private_Extension then
5124 Freeze_Before (N, Parent_Type);
5127 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
5128 and then not Is_Generic_Type (Derived_Type)
5130 if Is_Controlled (Parent_Type) then
5132 ("controlled type must be declared at the library level",
5136 ("type extension at deeper accessibility level than parent",
5142 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
5146 and then GB /= Enclosing_Generic_Body (Parent_Base)
5149 ("parent type of& must not be outside generic body"
5150 & " ('R'M 3.9.1(4))",
5151 Indic, Derived_Type);
5157 -- STEP 1b : preliminary cleanup of the full view of private types
5159 -- If the type is already marked as having discriminants, then it's the
5160 -- completion of a private type or private extension and we need to
5161 -- retain the discriminants from the partial view if the current
5162 -- declaration has Discriminant_Specifications so that we can verify
5163 -- conformance. However, we must remove any existing components that
5164 -- were inherited from the parent (and attached in Copy_And_Swap)
5165 -- because the full type inherits all appropriate components anyway, and
5166 -- we don't want the partial view's components interfering.
5168 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
5169 Discrim := First_Discriminant (Derived_Type);
5171 Last_Discrim := Discrim;
5172 Next_Discriminant (Discrim);
5173 exit when No (Discrim);
5176 Set_Last_Entity (Derived_Type, Last_Discrim);
5178 -- In all other cases wipe out the list of inherited components (even
5179 -- inherited discriminants), it will be properly rebuilt here.
5182 Set_First_Entity (Derived_Type, Empty);
5183 Set_Last_Entity (Derived_Type, Empty);
5186 -- STEP 1c: Initialize some flags for the Derived_Type
5188 -- The following flags must be initialized here so that
5189 -- Process_Discriminants can check that discriminants of tagged types
5190 -- do not have a default initial value and that access discriminants
5191 -- are only specified for limited records. For completeness, these
5192 -- flags are also initialized along with all the other flags below.
5194 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
5195 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
5197 -- STEP 2a: process discriminants of derived type if any.
5199 New_Scope (Derived_Type);
5201 if Discriminant_Specs then
5202 Set_Has_Unknown_Discriminants (Derived_Type, False);
5204 -- The following call initializes fields Has_Discriminants and
5205 -- Discriminant_Constraint, unless we are processing the completion
5206 -- of a private type declaration.
5208 Check_Or_Process_Discriminants (N, Derived_Type);
5210 -- For non-tagged types the constraint on the Parent_Type must be
5211 -- present and is used to rename the discriminants.
5213 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
5214 Error_Msg_N ("untagged parent must have discriminants", Indic);
5216 elsif not Is_Tagged and then not Constraint_Present then
5218 ("discriminant constraint needed for derived untagged records",
5221 -- Otherwise the parent subtype must be constrained unless we have a
5222 -- private extension.
5224 elsif not Constraint_Present
5225 and then not Private_Extension
5226 and then not Is_Constrained (Parent_Type)
5229 ("unconstrained type not allowed in this context", Indic);
5231 elsif Constraint_Present then
5232 -- The following call sets the field Corresponding_Discriminant
5233 -- for the discriminants in the Derived_Type.
5235 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
5237 -- For untagged types all new discriminants must rename
5238 -- discriminants in the parent. For private extensions new
5239 -- discriminants cannot rename old ones (implied by [7.3(13)]).
5241 Discrim := First_Discriminant (Derived_Type);
5243 while Present (Discrim) loop
5245 and then not Present (Corresponding_Discriminant (Discrim))
5248 ("new discriminants must constrain old ones", Discrim);
5250 elsif Private_Extension
5251 and then Present (Corresponding_Discriminant (Discrim))
5254 ("only static constraints allowed for parent"
5255 & " discriminants in the partial view", Indic);
5259 -- If a new discriminant is used in the constraint,
5260 -- then its subtype must be statically compatible
5261 -- with the parent discriminant's subtype (3.7(15)).
5263 if Present (Corresponding_Discriminant (Discrim))
5265 not Subtypes_Statically_Compatible
5267 Etype (Corresponding_Discriminant (Discrim)))
5270 ("subtype must be compatible with parent discriminant",
5274 Next_Discriminant (Discrim);
5277 -- Check whether the constraints of the full view statically
5278 -- match those imposed by the parent subtype [7.3(13)].
5280 if Present (Stored_Constraint (Derived_Type)) then
5285 C1 := First_Elmt (Discs);
5286 C2 := First_Elmt (Stored_Constraint (Derived_Type));
5287 while Present (C1) and then Present (C2) loop
5289 Fully_Conformant_Expressions (Node (C1), Node (C2))
5292 "not conformant with previous declaration",
5303 -- STEP 2b: No new discriminants, inherit discriminants if any
5306 if Private_Extension then
5307 Set_Has_Unknown_Discriminants
5309 Has_Unknown_Discriminants (Parent_Type)
5310 or else Unknown_Discriminants_Present (N));
5312 -- The partial view of the parent may have unknown discriminants,
5313 -- but if the full view has discriminants and the parent type is
5314 -- in scope they must be inherited.
5316 elsif Has_Unknown_Discriminants (Parent_Type)
5318 (not Has_Discriminants (Parent_Type)
5319 or else not In_Open_Scopes (Scope (Parent_Type)))
5321 Set_Has_Unknown_Discriminants (Derived_Type);
5324 if not Has_Unknown_Discriminants (Derived_Type)
5325 and then Has_Discriminants (Parent_Type)
5327 Inherit_Discrims := True;
5328 Set_Has_Discriminants
5329 (Derived_Type, True);
5330 Set_Discriminant_Constraint
5331 (Derived_Type, Discriminant_Constraint (Parent_Base));
5334 -- The following test is true for private types (remember
5335 -- transformation 5. is not applied to those) and in an error
5338 if Constraint_Present then
5339 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
5342 -- For now mark a new derived type as constrained only if it has no
5343 -- discriminants. At the end of Build_Derived_Record_Type we properly
5344 -- set this flag in the case of private extensions. See comments in
5345 -- point 9. just before body of Build_Derived_Record_Type.
5349 not (Inherit_Discrims
5350 or else Has_Unknown_Discriminants (Derived_Type)));
5353 -- STEP 3: initialize fields of derived type.
5355 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
5356 Set_Stored_Constraint (Derived_Type, No_Elist);
5358 -- Fields inherited from the Parent_Type
5361 (Derived_Type, Einfo.Discard_Names (Parent_Type));
5362 Set_Has_Specified_Layout
5363 (Derived_Type, Has_Specified_Layout (Parent_Type));
5364 Set_Is_Limited_Composite
5365 (Derived_Type, Is_Limited_Composite (Parent_Type));
5366 Set_Is_Limited_Record
5367 (Derived_Type, Is_Limited_Record (Parent_Type));
5368 Set_Is_Private_Composite
5369 (Derived_Type, Is_Private_Composite (Parent_Type));
5371 -- Fields inherited from the Parent_Base
5373 Set_Has_Controlled_Component
5374 (Derived_Type, Has_Controlled_Component (Parent_Base));
5375 Set_Has_Non_Standard_Rep
5376 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
5377 Set_Has_Primitive_Operations
5378 (Derived_Type, Has_Primitive_Operations (Parent_Base));
5380 -- Direct controlled types do not inherit Finalize_Storage_Only flag
5382 if not Is_Controlled (Parent_Type) then
5383 Set_Finalize_Storage_Only
5384 (Derived_Type, Finalize_Storage_Only (Parent_Type));
5387 -- Set fields for private derived types.
5389 if Is_Private_Type (Derived_Type) then
5390 Set_Depends_On_Private (Derived_Type, True);
5391 Set_Private_Dependents (Derived_Type, New_Elmt_List);
5393 -- Inherit fields from non private record types. If this is the
5394 -- completion of a derivation from a private type, the parent itself
5395 -- is private, and the attributes come from its full view, which must
5399 if Is_Private_Type (Parent_Base)
5400 and then not Is_Record_Type (Parent_Base)
5402 Set_Component_Alignment
5403 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
5405 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
5407 Set_Component_Alignment
5408 (Derived_Type, Component_Alignment (Parent_Base));
5411 (Derived_Type, C_Pass_By_Copy (Parent_Base));
5415 -- Set fields for tagged types
5418 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
5420 -- All tagged types defined in Ada.Finalization are controlled
5422 if Chars (Scope (Derived_Type)) = Name_Finalization
5423 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
5424 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
5426 Set_Is_Controlled (Derived_Type);
5428 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
5431 Make_Class_Wide_Type (Derived_Type);
5432 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
5434 if Has_Discriminants (Derived_Type)
5435 and then Constraint_Present
5437 Set_Stored_Constraint
5438 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
5442 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
5443 Set_Has_Non_Standard_Rep
5444 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
5447 -- STEP 4: Inherit components from the parent base and constrain them.
5448 -- Apply the second transformation described in point 6. above.
5450 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
5451 or else not Has_Discriminants (Parent_Type)
5452 or else not Is_Constrained (Parent_Type)
5456 Constrs := Discriminant_Constraint (Parent_Type);
5459 Assoc_List := Inherit_Components (N,
5460 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
5462 -- STEP 5a: Copy the parent record declaration for untagged types
5464 if not Is_Tagged then
5466 -- Discriminant_Constraint (Derived_Type) has been properly
5467 -- constructed. Save it and temporarily set it to Empty because we do
5468 -- not want the call to New_Copy_Tree below to mess this list.
5470 if Has_Discriminants (Derived_Type) then
5471 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
5472 Set_Discriminant_Constraint (Derived_Type, No_Elist);
5474 Save_Discr_Constr := No_Elist;
5477 -- Save the Etype field of Derived_Type. It is correctly set now, but
5478 -- the call to New_Copy tree may remap it to point to itself, which
5479 -- is not what we want. Ditto for the Next_Entity field.
5481 Save_Etype := Etype (Derived_Type);
5482 Save_Next_Entity := Next_Entity (Derived_Type);
5484 -- Assoc_List maps all stored discriminants in the Parent_Base to
5485 -- stored discriminants in the Derived_Type. It is fundamental that
5486 -- no types or itypes with discriminants other than the stored
5487 -- discriminants appear in the entities declared inside
5488 -- Derived_Type. Gigi won't like it.
5492 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
5494 -- Restore the fields saved prior to the New_Copy_Tree call
5495 -- and compute the stored constraint.
5497 Set_Etype (Derived_Type, Save_Etype);
5498 Set_Next_Entity (Derived_Type, Save_Next_Entity);
5500 if Has_Discriminants (Derived_Type) then
5501 Set_Discriminant_Constraint
5502 (Derived_Type, Save_Discr_Constr);
5503 Set_Stored_Constraint
5504 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
5505 Replace_Components (Derived_Type, New_Decl);
5508 -- Insert the new derived type declaration
5510 Rewrite (N, New_Decl);
5512 -- STEP 5b: Complete the processing for record extensions in generics
5514 -- There is no completion for record extensions declared in the
5515 -- parameter part of a generic, so we need to complete processing for
5516 -- these generic record extensions here. The Record_Type_Definition call
5517 -- will change the Ekind of the components from E_Void to E_Component.
5519 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
5520 Record_Type_Definition (Empty, Derived_Type);
5522 -- STEP 5c: Process the record extension for non private tagged types.
5524 elsif not Private_Extension then
5525 -- Add the _parent field in the derived type.
5527 Expand_Derived_Record (Derived_Type, Type_Def);
5529 -- Analyze the record extension
5531 Record_Type_Definition
5532 (Record_Extension_Part (Type_Def), Derived_Type);
5537 if Etype (Derived_Type) = Any_Type then
5541 -- Set delayed freeze and then derive subprograms, we need to do
5542 -- this in this order so that derived subprograms inherit the
5543 -- derived freeze if necessary.
5545 Set_Has_Delayed_Freeze (Derived_Type);
5546 if Derive_Subps then
5547 Derive_Subprograms (Parent_Type, Derived_Type);
5550 -- If we have a private extension which defines a constrained derived
5551 -- type mark as constrained here after we have derived subprograms. See
5552 -- comment on point 9. just above the body of Build_Derived_Record_Type.
5554 if Private_Extension and then Inherit_Discrims then
5555 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
5556 Set_Is_Constrained (Derived_Type, True);
5557 Set_Discriminant_Constraint (Derived_Type, Discs);
5559 elsif Is_Constrained (Parent_Type) then
5561 (Derived_Type, True);
5562 Set_Discriminant_Constraint
5563 (Derived_Type, Discriminant_Constraint (Parent_Type));
5567 end Build_Derived_Record_Type;
5569 ------------------------
5570 -- Build_Derived_Type --
5571 ------------------------
5573 procedure Build_Derived_Type
5575 Parent_Type : Entity_Id;
5576 Derived_Type : Entity_Id;
5577 Is_Completion : Boolean;
5578 Derive_Subps : Boolean := True)
5580 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5583 -- Set common attributes
5585 Set_Scope (Derived_Type, Current_Scope);
5587 Set_Ekind (Derived_Type, Ekind (Parent_Base));
5588 Set_Etype (Derived_Type, Parent_Base);
5589 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
5591 Set_Size_Info (Derived_Type, Parent_Type);
5592 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5593 Set_Convention (Derived_Type, Convention (Parent_Type));
5594 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
5596 -- The derived type inherits the representation clauses of the parent.
5597 -- However, for a private type that is completed by a derivation, there
5598 -- may be operation attributes that have been specified already (stream
5599 -- attributes and External_Tag) and those must be provided. Finally,
5600 -- if the partial view is a private extension, the representation items
5601 -- of the parent have been inherited already, and should not be chained
5602 -- twice to the derived type.
5604 if Is_Tagged_Type (Parent_Type)
5605 and then Present (First_Rep_Item (Derived_Type))
5607 -- The existing items are either operational items or items inherited
5608 -- from a private extension declaration.
5611 Rep : Node_Id := First_Rep_Item (Derived_Type);
5612 Found : Boolean := False;
5615 while Present (Rep) loop
5616 if Rep = First_Rep_Item (Parent_Type) then
5620 Rep := Next_Rep_Item (Rep);
5626 (First_Rep_Item (Derived_Type), First_Rep_Item (Parent_Type));
5631 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
5634 case Ekind (Parent_Type) is
5635 when Numeric_Kind =>
5636 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
5639 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
5643 | Class_Wide_Kind =>
5644 Build_Derived_Record_Type
5645 (N, Parent_Type, Derived_Type, Derive_Subps);
5648 when Enumeration_Kind =>
5649 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5652 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5654 when Incomplete_Or_Private_Kind =>
5655 Build_Derived_Private_Type
5656 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5658 -- For discriminated types, the derivation includes deriving
5659 -- primitive operations. For others it is done below.
5661 if Is_Tagged_Type (Parent_Type)
5662 or else Has_Discriminants (Parent_Type)
5663 or else (Present (Full_View (Parent_Type))
5664 and then Has_Discriminants (Full_View (Parent_Type)))
5669 when Concurrent_Kind =>
5670 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5673 raise Program_Error;
5676 if Etype (Derived_Type) = Any_Type then
5680 -- Set delayed freeze and then derive subprograms, we need to do
5681 -- this in this order so that derived subprograms inherit the
5682 -- derived freeze if necessary.
5684 Set_Has_Delayed_Freeze (Derived_Type);
5685 if Derive_Subps then
5686 Derive_Subprograms (Parent_Type, Derived_Type);
5689 Set_Has_Primitive_Operations
5690 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5691 end Build_Derived_Type;
5693 -----------------------
5694 -- Build_Discriminal --
5695 -----------------------
5697 procedure Build_Discriminal (Discrim : Entity_Id) is
5698 D_Minal : Entity_Id;
5699 CR_Disc : Entity_Id;
5702 -- A discriminal has the same names as the discriminant.
5704 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5706 Set_Ekind (D_Minal, E_In_Parameter);
5707 Set_Mechanism (D_Minal, Default_Mechanism);
5708 Set_Etype (D_Minal, Etype (Discrim));
5710 Set_Discriminal (Discrim, D_Minal);
5711 Set_Discriminal_Link (D_Minal, Discrim);
5713 -- For task types, build at once the discriminants of the corresponding
5714 -- record, which are needed if discriminants are used in entry defaults
5715 -- and in family bounds.
5717 if Is_Concurrent_Type (Current_Scope)
5718 or else Is_Limited_Type (Current_Scope)
5720 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5722 Set_Ekind (CR_Disc, E_In_Parameter);
5723 Set_Mechanism (CR_Disc, Default_Mechanism);
5724 Set_Etype (CR_Disc, Etype (Discrim));
5725 Set_CR_Discriminant (Discrim, CR_Disc);
5727 end Build_Discriminal;
5729 ------------------------------------
5730 -- Build_Discriminant_Constraints --
5731 ------------------------------------
5733 function Build_Discriminant_Constraints
5736 Derived_Def : Boolean := False) return Elist_Id
5738 C : constant Node_Id := Constraint (Def);
5739 Nb_Discr : constant Nat := Number_Discriminants (T);
5740 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5741 -- Saves the expression corresponding to a given discriminant in T.
5743 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5744 -- Return the Position number within array Discr_Expr of a discriminant
5745 -- D within the discriminant list of the discriminated type T.
5751 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5755 Disc := First_Discriminant (T);
5756 for J in Discr_Expr'Range loop
5761 Next_Discriminant (Disc);
5764 -- Note: Since this function is called on discriminants that are
5765 -- known to belong to the discriminated type, falling through the
5766 -- loop with no match signals an internal compiler error.
5768 raise Program_Error;
5771 -- Declarations local to Build_Discriminant_Constraints
5775 Elist : constant Elist_Id := New_Elmt_List;
5783 Discrim_Present : Boolean := False;
5785 -- Start of processing for Build_Discriminant_Constraints
5788 -- The following loop will process positional associations only.
5789 -- For a positional association, the (single) discriminant is
5790 -- implicitly specified by position, in textual order (RM 3.7.2).
5792 Discr := First_Discriminant (T);
5793 Constr := First (Constraints (C));
5795 for D in Discr_Expr'Range loop
5796 exit when Nkind (Constr) = N_Discriminant_Association;
5799 Error_Msg_N ("too few discriminants given in constraint", C);
5800 return New_Elmt_List;
5802 elsif Nkind (Constr) = N_Range
5803 or else (Nkind (Constr) = N_Attribute_Reference
5805 Attribute_Name (Constr) = Name_Range)
5808 ("a range is not a valid discriminant constraint", Constr);
5809 Discr_Expr (D) := Error;
5812 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5813 Discr_Expr (D) := Constr;
5816 Next_Discriminant (Discr);
5820 if No (Discr) and then Present (Constr) then
5821 Error_Msg_N ("too many discriminants given in constraint", Constr);
5822 return New_Elmt_List;
5825 -- Named associations can be given in any order, but if both positional
5826 -- and named associations are used in the same discriminant constraint,
5827 -- then positional associations must occur first, at their normal
5828 -- position. Hence once a named association is used, the rest of the
5829 -- discriminant constraint must use only named associations.
5831 while Present (Constr) loop
5833 -- Positional association forbidden after a named association.
5835 if Nkind (Constr) /= N_Discriminant_Association then
5836 Error_Msg_N ("positional association follows named one", Constr);
5837 return New_Elmt_List;
5839 -- Otherwise it is a named association
5842 -- E records the type of the discriminants in the named
5843 -- association. All the discriminants specified in the same name
5844 -- association must have the same type.
5848 -- Search the list of discriminants in T to see if the simple name
5849 -- given in the constraint matches any of them.
5851 Id := First (Selector_Names (Constr));
5852 while Present (Id) loop
5855 -- If Original_Discriminant is present, we are processing a
5856 -- generic instantiation and this is an instance node. We need
5857 -- to find the name of the corresponding discriminant in the
5858 -- actual record type T and not the name of the discriminant in
5859 -- the generic formal. Example:
5862 -- type G (D : int) is private;
5864 -- subtype W is G (D => 1);
5866 -- type Rec (X : int) is record ... end record;
5867 -- package Q is new P (G => Rec);
5869 -- At the point of the instantiation, formal type G is Rec
5870 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5871 -- which really looks like "subtype W is Rec (D => 1);" at
5872 -- the point of instantiation, we want to find the discriminant
5873 -- that corresponds to D in Rec, ie X.
5875 if Present (Original_Discriminant (Id)) then
5876 Discr := Find_Corresponding_Discriminant (Id, T);
5880 Discr := First_Discriminant (T);
5881 while Present (Discr) loop
5882 if Chars (Discr) = Chars (Id) then
5887 Next_Discriminant (Discr);
5891 Error_Msg_N ("& does not match any discriminant", Id);
5892 return New_Elmt_List;
5894 -- The following is only useful for the benefit of generic
5895 -- instances but it does not interfere with other
5896 -- processing for the non-generic case so we do it in all
5897 -- cases (for generics this statement is executed when
5898 -- processing the generic definition, see comment at the
5899 -- beginning of this if statement).
5902 Set_Original_Discriminant (Id, Discr);
5906 Position := Pos_Of_Discr (T, Discr);
5908 if Present (Discr_Expr (Position)) then
5909 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5912 -- Each discriminant specified in the same named association
5913 -- must be associated with a separate copy of the
5914 -- corresponding expression.
5916 if Present (Next (Id)) then
5917 Expr := New_Copy_Tree (Expression (Constr));
5918 Set_Parent (Expr, Parent (Expression (Constr)));
5920 Expr := Expression (Constr);
5923 Discr_Expr (Position) := Expr;
5924 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
5927 -- A discriminant association with more than one discriminant
5928 -- name is only allowed if the named discriminants are all of
5929 -- the same type (RM 3.7.1(8)).
5932 E := Base_Type (Etype (Discr));
5934 elsif Base_Type (Etype (Discr)) /= E then
5936 ("all discriminants in an association " &
5937 "must have the same type", Id);
5947 -- A discriminant constraint must provide exactly one value for each
5948 -- discriminant of the type (RM 3.7.1(8)).
5950 for J in Discr_Expr'Range loop
5951 if No (Discr_Expr (J)) then
5952 Error_Msg_N ("too few discriminants given in constraint", C);
5953 return New_Elmt_List;
5957 -- Determine if there are discriminant expressions in the constraint.
5959 for J in Discr_Expr'Range loop
5960 if Denotes_Discriminant (Discr_Expr (J), Check_Protected => True) then
5961 Discrim_Present := True;
5965 -- Build an element list consisting of the expressions given in the
5966 -- discriminant constraint and apply the appropriate checks. The list
5967 -- is constructed after resolving any named discriminant associations
5968 -- and therefore the expressions appear in the textual order of the
5971 Discr := First_Discriminant (T);
5972 for J in Discr_Expr'Range loop
5973 if Discr_Expr (J) /= Error then
5975 Append_Elmt (Discr_Expr (J), Elist);
5977 -- If any of the discriminant constraints is given by a
5978 -- discriminant and we are in a derived type declaration we
5979 -- have a discriminant renaming. Establish link between new
5980 -- and old discriminant.
5982 if Denotes_Discriminant (Discr_Expr (J)) then
5984 Set_Corresponding_Discriminant
5985 (Entity (Discr_Expr (J)), Discr);
5988 -- Force the evaluation of non-discriminant expressions.
5989 -- If we have found a discriminant in the constraint 3.4(26)
5990 -- and 3.8(18) demand that no range checks are performed are
5991 -- after evaluation. If the constraint is for a component
5992 -- definition that has a per-object constraint, expressions are
5993 -- evaluated but not checked either. In all other cases perform
5997 if Discrim_Present then
6000 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
6002 Has_Per_Object_Constraint
6003 (Defining_Identifier (Parent (Parent (Def))))
6007 elsif Is_Access_Type (Etype (Discr)) then
6008 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
6011 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
6014 Force_Evaluation (Discr_Expr (J));
6017 -- Check that the designated type of an access discriminant's
6018 -- expression is not a class-wide type unless the discriminant's
6019 -- designated type is also class-wide.
6021 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
6022 and then not Is_Class_Wide_Type
6023 (Designated_Type (Etype (Discr)))
6024 and then Etype (Discr_Expr (J)) /= Any_Type
6025 and then Is_Class_Wide_Type
6026 (Designated_Type (Etype (Discr_Expr (J))))
6028 Wrong_Type (Discr_Expr (J), Etype (Discr));
6032 Next_Discriminant (Discr);
6036 end Build_Discriminant_Constraints;
6038 ---------------------------------
6039 -- Build_Discriminated_Subtype --
6040 ---------------------------------
6042 procedure Build_Discriminated_Subtype
6046 Related_Nod : Node_Id;
6047 For_Access : Boolean := False)
6049 Has_Discrs : constant Boolean := Has_Discriminants (T);
6050 Constrained : constant Boolean
6052 and then not Is_Empty_Elmt_List (Elist)
6053 and then not Is_Class_Wide_Type (T))
6054 or else Is_Constrained (T);
6057 if Ekind (T) = E_Record_Type then
6059 Set_Ekind (Def_Id, E_Private_Subtype);
6060 Set_Is_For_Access_Subtype (Def_Id, True);
6062 Set_Ekind (Def_Id, E_Record_Subtype);
6065 elsif Ekind (T) = E_Task_Type then
6066 Set_Ekind (Def_Id, E_Task_Subtype);
6068 elsif Ekind (T) = E_Protected_Type then
6069 Set_Ekind (Def_Id, E_Protected_Subtype);
6071 elsif Is_Private_Type (T) then
6072 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
6074 elsif Is_Class_Wide_Type (T) then
6075 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
6078 -- Incomplete type. Attach subtype to list of dependents, to be
6079 -- completed with full view of parent type.
6081 Set_Ekind (Def_Id, Ekind (T));
6082 Append_Elmt (Def_Id, Private_Dependents (T));
6085 Set_Etype (Def_Id, T);
6086 Init_Size_Align (Def_Id);
6087 Set_Has_Discriminants (Def_Id, Has_Discrs);
6088 Set_Is_Constrained (Def_Id, Constrained);
6090 Set_First_Entity (Def_Id, First_Entity (T));
6091 Set_Last_Entity (Def_Id, Last_Entity (T));
6092 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6094 if Is_Tagged_Type (T) then
6095 Set_Is_Tagged_Type (Def_Id);
6096 Make_Class_Wide_Type (Def_Id);
6099 Set_Stored_Constraint (Def_Id, No_Elist);
6102 Set_Discriminant_Constraint (Def_Id, Elist);
6103 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
6106 if Is_Tagged_Type (T) then
6107 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
6108 Set_Is_Abstract (Def_Id, Is_Abstract (T));
6111 -- Subtypes introduced by component declarations do not need to be
6112 -- marked as delayed, and do not get freeze nodes, because the semantics
6113 -- verifies that the parents of the subtypes are frozen before the
6114 -- enclosing record is frozen.
6116 if not Is_Type (Scope (Def_Id)) then
6117 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6119 if Is_Private_Type (T)
6120 and then Present (Full_View (T))
6122 Conditional_Delay (Def_Id, Full_View (T));
6124 Conditional_Delay (Def_Id, T);
6128 if Is_Record_Type (T) then
6129 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
6132 and then not Is_Empty_Elmt_List (Elist)
6133 and then not For_Access
6135 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
6136 elsif not For_Access then
6137 Set_Cloned_Subtype (Def_Id, T);
6141 end Build_Discriminated_Subtype;
6143 ------------------------
6144 -- Build_Scalar_Bound --
6145 ------------------------
6147 function Build_Scalar_Bound
6150 Der_T : Entity_Id) return Node_Id
6152 New_Bound : Entity_Id;
6155 -- Note: not clear why this is needed, how can the original bound
6156 -- be unanalyzed at this point? and if it is, what business do we
6157 -- have messing around with it? and why is the base type of the
6158 -- parent type the right type for the resolution. It probably is
6159 -- not! It is OK for the new bound we are creating, but not for
6160 -- the old one??? Still if it never happens, no problem!
6162 Analyze_And_Resolve (Bound, Base_Type (Par_T));
6164 if Nkind (Bound) = N_Integer_Literal
6165 or else Nkind (Bound) = N_Real_Literal
6167 New_Bound := New_Copy (Bound);
6168 Set_Etype (New_Bound, Der_T);
6169 Set_Analyzed (New_Bound);
6171 elsif Is_Entity_Name (Bound) then
6172 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
6174 -- The following is almost certainly wrong. What business do we have
6175 -- relocating a node (Bound) that is presumably still attached to
6176 -- the tree elsewhere???
6179 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
6182 Set_Etype (New_Bound, Der_T);
6184 end Build_Scalar_Bound;
6186 --------------------------------
6187 -- Build_Underlying_Full_View --
6188 --------------------------------
6190 procedure Build_Underlying_Full_View
6195 Loc : constant Source_Ptr := Sloc (N);
6196 Subt : constant Entity_Id :=
6197 Make_Defining_Identifier
6198 (Loc, New_External_Name (Chars (Typ), 'S'));
6206 if Nkind (N) = N_Full_Type_Declaration then
6207 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
6209 -- ??? ??? is this assert right, I assume so otherwise Constr
6210 -- would not be defined below (this used to be an elsif)
6212 else pragma Assert (Nkind (N) = N_Subtype_Declaration);
6213 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
6216 -- If the constraint has discriminant associations, the discriminant
6217 -- entity is already set, but it denotes a discriminant of the new
6218 -- type, not the original parent, so it must be found anew.
6220 C := First (Constraints (Constr));
6222 while Present (C) loop
6224 if Nkind (C) = N_Discriminant_Association then
6225 Id := First (Selector_Names (C));
6227 while Present (Id) loop
6228 Set_Original_Discriminant (Id, Empty);
6236 Indic := Make_Subtype_Declaration (Loc,
6237 Defining_Identifier => Subt,
6238 Subtype_Indication =>
6239 Make_Subtype_Indication (Loc,
6240 Subtype_Mark => New_Reference_To (Par, Loc),
6241 Constraint => New_Copy_Tree (Constr)));
6243 Insert_Before (N, Indic);
6245 Set_Underlying_Full_View (Typ, Full_View (Subt));
6246 end Build_Underlying_Full_View;
6248 -------------------------------
6249 -- Check_Abstract_Overriding --
6250 -------------------------------
6252 procedure Check_Abstract_Overriding (T : Entity_Id) is
6259 Op_List := Primitive_Operations (T);
6261 -- Loop to check primitive operations
6263 Elmt := First_Elmt (Op_List);
6264 while Present (Elmt) loop
6265 Subp := Node (Elmt);
6267 -- Special exception, do not complain about failure to
6268 -- override _Input and _Output, since we always provide
6269 -- automatic overridings for these subprograms.
6271 if Is_Abstract (Subp)
6272 and then not Is_TSS (Subp, TSS_Stream_Input)
6273 and then not Is_TSS (Subp, TSS_Stream_Output)
6274 and then not Is_Abstract (T)
6276 if Present (Alias (Subp)) then
6277 -- Only perform the check for a derived subprogram when
6278 -- the type has an explicit record extension. This avoids
6279 -- incorrectly flagging abstract subprograms for the case
6280 -- of a type without an extension derived from a formal type
6281 -- with a tagged actual (can occur within a private part).
6283 Type_Def := Type_Definition (Parent (T));
6284 if Nkind (Type_Def) = N_Derived_Type_Definition
6285 and then Present (Record_Extension_Part (Type_Def))
6288 ("type must be declared abstract or & overridden",
6293 ("abstract subprogram not allowed for type&",
6296 ("nonabstract type has abstract subprogram&",
6303 end Check_Abstract_Overriding;
6305 ------------------------------------------------
6306 -- Check_Access_Discriminant_Requires_Limited --
6307 ------------------------------------------------
6309 procedure Check_Access_Discriminant_Requires_Limited
6314 -- A discriminant_specification for an access discriminant
6315 -- shall appear only in the declaration for a task or protected
6316 -- type, or for a type with the reserved word 'limited' in
6317 -- its definition or in one of its ancestors. (RM 3.7(10))
6319 if Nkind (Discriminant_Type (D)) = N_Access_Definition
6320 and then not Is_Concurrent_Type (Current_Scope)
6321 and then not Is_Concurrent_Record_Type (Current_Scope)
6322 and then not Is_Limited_Record (Current_Scope)
6323 and then Ekind (Current_Scope) /= E_Limited_Private_Type
6326 ("access discriminants allowed only for limited types", Loc);
6328 end Check_Access_Discriminant_Requires_Limited;
6330 -----------------------------------
6331 -- Check_Aliased_Component_Types --
6332 -----------------------------------
6334 procedure Check_Aliased_Component_Types (T : Entity_Id) is
6338 -- ??? Also need to check components of record extensions,
6339 -- but not components of protected types (which are always
6342 if not Is_Limited_Type (T) then
6343 if Ekind (T) = E_Record_Type then
6344 C := First_Component (T);
6345 while Present (C) loop
6347 and then Has_Discriminants (Etype (C))
6348 and then not Is_Constrained (Etype (C))
6349 and then not In_Instance
6352 ("aliased component must be constrained ('R'M 3.6(11))",
6359 elsif Ekind (T) = E_Array_Type then
6360 if Has_Aliased_Components (T)
6361 and then Has_Discriminants (Component_Type (T))
6362 and then not Is_Constrained (Component_Type (T))
6363 and then not In_Instance
6366 ("aliased component type must be constrained ('R'M 3.6(11))",
6371 end Check_Aliased_Component_Types;
6373 ----------------------
6374 -- Check_Completion --
6375 ----------------------
6377 procedure Check_Completion (Body_Id : Node_Id := Empty) is
6380 procedure Post_Error;
6381 -- Post error message for lack of completion for entity E
6387 procedure Post_Error is
6389 if not Comes_From_Source (E) then
6391 if Ekind (E) = E_Task_Type
6392 or else Ekind (E) = E_Protected_Type
6394 -- It may be an anonymous protected type created for a
6395 -- single variable. Post error on variable, if present.
6401 Var := First_Entity (Current_Scope);
6403 while Present (Var) loop
6404 exit when Etype (Var) = E
6405 and then Comes_From_Source (Var);
6410 if Present (Var) then
6417 -- If a generated entity has no completion, then either previous
6418 -- semantic errors have disabled the expansion phase, or else
6419 -- we had missing subunits, or else we are compiling without expan-
6420 -- sion, or else something is very wrong.
6422 if not Comes_From_Source (E) then
6424 (Serious_Errors_Detected > 0
6425 or else Configurable_Run_Time_Violations > 0
6426 or else Subunits_Missing
6427 or else not Expander_Active);
6430 -- Here for source entity
6433 -- Here if no body to post the error message, so we post the error
6434 -- on the declaration that has no completion. This is not really
6435 -- the right place to post it, think about this later ???
6437 if No (Body_Id) then
6440 ("missing full declaration for }", Parent (E), E);
6443 ("missing body for &", Parent (E), E);
6446 -- Package body has no completion for a declaration that appears
6447 -- in the corresponding spec. Post error on the body, with a
6448 -- reference to the non-completed declaration.
6451 Error_Msg_Sloc := Sloc (E);
6455 ("missing full declaration for }!", Body_Id, E);
6457 elsif Is_Overloadable (E)
6458 and then Current_Entity_In_Scope (E) /= E
6460 -- It may be that the completion is mistyped and appears
6461 -- as a distinct overloading of the entity.
6464 Candidate : constant Entity_Id :=
6465 Current_Entity_In_Scope (E);
6466 Decl : constant Node_Id :=
6467 Unit_Declaration_Node (Candidate);
6470 if Is_Overloadable (Candidate)
6471 and then Ekind (Candidate) = Ekind (E)
6472 and then Nkind (Decl) = N_Subprogram_Body
6473 and then Acts_As_Spec (Decl)
6475 Check_Type_Conformant (Candidate, E);
6478 Error_Msg_NE ("missing body for & declared#!",
6483 Error_Msg_NE ("missing body for & declared#!",
6490 -- Start processing for Check_Completion
6493 E := First_Entity (Current_Scope);
6494 while Present (E) loop
6495 if Is_Intrinsic_Subprogram (E) then
6498 -- The following situation requires special handling: a child
6499 -- unit that appears in the context clause of the body of its
6502 -- procedure Parent.Child (...);
6504 -- with Parent.Child;
6505 -- package body Parent is
6507 -- Here Parent.Child appears as a local entity, but should not
6508 -- be flagged as requiring completion, because it is a
6509 -- compilation unit.
6511 elsif Ekind (E) = E_Function
6512 or else Ekind (E) = E_Procedure
6513 or else Ekind (E) = E_Generic_Function
6514 or else Ekind (E) = E_Generic_Procedure
6516 if not Has_Completion (E)
6517 and then not Is_Abstract (E)
6518 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
6520 and then Chars (E) /= Name_uSize
6525 elsif Is_Entry (E) then
6526 if not Has_Completion (E) and then
6527 (Ekind (Scope (E)) = E_Protected_Object
6528 or else Ekind (Scope (E)) = E_Protected_Type)
6533 elsif Is_Package (E) then
6534 if Unit_Requires_Body (E) then
6535 if not Has_Completion (E)
6536 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
6542 elsif not Is_Child_Unit (E) then
6543 May_Need_Implicit_Body (E);
6546 elsif Ekind (E) = E_Incomplete_Type
6547 and then No (Underlying_Type (E))
6551 elsif (Ekind (E) = E_Task_Type or else
6552 Ekind (E) = E_Protected_Type)
6553 and then not Has_Completion (E)
6557 -- A single task declared in the current scope is
6558 -- a constant, verify that the body of its anonymous
6559 -- type is in the same scope. If the task is defined
6560 -- elsewhere, this may be a renaming declaration for
6561 -- which no completion is needed.
6563 elsif Ekind (E) = E_Constant
6564 and then Ekind (Etype (E)) = E_Task_Type
6565 and then not Has_Completion (Etype (E))
6566 and then Scope (Etype (E)) = Current_Scope
6570 elsif Ekind (E) = E_Protected_Object
6571 and then not Has_Completion (Etype (E))
6575 elsif Ekind (E) = E_Record_Type then
6576 if Is_Tagged_Type (E) then
6577 Check_Abstract_Overriding (E);
6580 Check_Aliased_Component_Types (E);
6582 elsif Ekind (E) = E_Array_Type then
6583 Check_Aliased_Component_Types (E);
6589 end Check_Completion;
6591 ----------------------------
6592 -- Check_Delta_Expression --
6593 ----------------------------
6595 procedure Check_Delta_Expression (E : Node_Id) is
6597 if not (Is_Real_Type (Etype (E))) then
6598 Wrong_Type (E, Any_Real);
6600 elsif not Is_OK_Static_Expression (E) then
6601 Flag_Non_Static_Expr
6602 ("non-static expression used for delta value!", E);
6604 elsif not UR_Is_Positive (Expr_Value_R (E)) then
6605 Error_Msg_N ("delta expression must be positive", E);
6611 -- If any of above errors occurred, then replace the incorrect
6612 -- expression by the real 0.1, which should prevent further errors.
6615 Make_Real_Literal (Sloc (E), Ureal_Tenth));
6616 Analyze_And_Resolve (E, Standard_Float);
6618 end Check_Delta_Expression;
6620 -----------------------------
6621 -- Check_Digits_Expression --
6622 -----------------------------
6624 procedure Check_Digits_Expression (E : Node_Id) is
6626 if not (Is_Integer_Type (Etype (E))) then
6627 Wrong_Type (E, Any_Integer);
6629 elsif not Is_OK_Static_Expression (E) then
6630 Flag_Non_Static_Expr
6631 ("non-static expression used for digits value!", E);
6633 elsif Expr_Value (E) <= 0 then
6634 Error_Msg_N ("digits value must be greater than zero", E);
6640 -- If any of above errors occurred, then replace the incorrect
6641 -- expression by the integer 1, which should prevent further errors.
6643 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
6644 Analyze_And_Resolve (E, Standard_Integer);
6646 end Check_Digits_Expression;
6648 --------------------------
6649 -- Check_Initialization --
6650 --------------------------
6652 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
6654 if (Is_Limited_Type (T)
6655 or else Is_Limited_Composite (T))
6656 and then not In_Instance
6657 and then not In_Inlined_Body
6659 -- Ada 2005 (AI-287): Relax the strictness of the front-end in
6660 -- case of limited aggregates and extension aggregates.
6662 if Ada_Version >= Ada_05
6663 and then (Nkind (Exp) = N_Aggregate
6664 or else Nkind (Exp) = N_Extension_Aggregate)
6669 ("cannot initialize entities of limited type", Exp);
6670 Explain_Limited_Type (T, Exp);
6673 end Check_Initialization;
6675 ------------------------------------
6676 -- Check_Or_Process_Discriminants --
6677 ------------------------------------
6679 -- If an incomplete or private type declaration was already given for
6680 -- the type, the discriminants may have already been processed if they
6681 -- were present on the incomplete declaration. In this case a full
6682 -- conformance check is performed otherwise just process them.
6684 procedure Check_Or_Process_Discriminants
6687 Prev : Entity_Id := Empty)
6690 if Has_Discriminants (T) then
6692 -- Make the discriminants visible to component declarations.
6695 D : Entity_Id := First_Discriminant (T);
6699 while Present (D) loop
6700 Prev := Current_Entity (D);
6701 Set_Current_Entity (D);
6702 Set_Is_Immediately_Visible (D);
6703 Set_Homonym (D, Prev);
6705 -- Ada 2005 (AI-230): Access discriminant allowed in
6706 -- non-limited record types.
6708 if Ada_Version < Ada_05 then
6710 -- This restriction gets applied to the full type here; it
6711 -- has already been applied earlier to the partial view
6713 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6716 Next_Discriminant (D);
6720 elsif Present (Discriminant_Specifications (N)) then
6721 Process_Discriminants (N, Prev);
6723 end Check_Or_Process_Discriminants;
6725 ----------------------
6726 -- Check_Real_Bound --
6727 ----------------------
6729 procedure Check_Real_Bound (Bound : Node_Id) is
6731 if not Is_Real_Type (Etype (Bound)) then
6733 ("bound in real type definition must be of real type", Bound);
6735 elsif not Is_OK_Static_Expression (Bound) then
6736 Flag_Non_Static_Expr
6737 ("non-static expression used for real type bound!", Bound);
6744 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6746 Resolve (Bound, Standard_Float);
6747 end Check_Real_Bound;
6749 ------------------------------
6750 -- Complete_Private_Subtype --
6751 ------------------------------
6753 procedure Complete_Private_Subtype
6756 Full_Base : Entity_Id;
6757 Related_Nod : Node_Id)
6759 Save_Next_Entity : Entity_Id;
6760 Save_Homonym : Entity_Id;
6763 -- Set semantic attributes for (implicit) private subtype completion.
6764 -- If the full type has no discriminants, then it is a copy of the full
6765 -- view of the base. Otherwise, it is a subtype of the base with a
6766 -- possible discriminant constraint. Save and restore the original
6767 -- Next_Entity field of full to ensure that the calls to Copy_Node
6768 -- do not corrupt the entity chain.
6770 -- Note that the type of the full view is the same entity as the
6771 -- type of the partial view. In this fashion, the subtype has
6772 -- access to the correct view of the parent.
6774 Save_Next_Entity := Next_Entity (Full);
6775 Save_Homonym := Homonym (Priv);
6777 case Ekind (Full_Base) is
6779 when E_Record_Type |
6785 Copy_Node (Priv, Full);
6787 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6788 Set_First_Entity (Full, First_Entity (Full_Base));
6789 Set_Last_Entity (Full, Last_Entity (Full_Base));
6792 Copy_Node (Full_Base, Full);
6793 Set_Chars (Full, Chars (Priv));
6794 Conditional_Delay (Full, Priv);
6795 Set_Sloc (Full, Sloc (Priv));
6799 Set_Next_Entity (Full, Save_Next_Entity);
6800 Set_Homonym (Full, Save_Homonym);
6801 Set_Associated_Node_For_Itype (Full, Related_Nod);
6803 -- Set common attributes for all subtypes.
6805 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6807 -- The Etype of the full view is inconsistent. Gigi needs to see the
6808 -- structural full view, which is what the current scheme gives:
6809 -- the Etype of the full view is the etype of the full base. However,
6810 -- if the full base is a derived type, the full view then looks like
6811 -- a subtype of the parent, not a subtype of the full base. If instead
6814 -- Set_Etype (Full, Full_Base);
6816 -- then we get inconsistencies in the front-end (confusion between
6817 -- views). Several outstanding bugs are related to this.
6819 Set_Is_First_Subtype (Full, False);
6820 Set_Scope (Full, Scope (Priv));
6821 Set_Size_Info (Full, Full_Base);
6822 Set_RM_Size (Full, RM_Size (Full_Base));
6823 Set_Is_Itype (Full);
6825 -- A subtype of a private-type-without-discriminants, whose full-view
6826 -- has discriminants with default expressions, is not constrained!
6828 if not Has_Discriminants (Priv) then
6829 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6831 if Has_Discriminants (Full_Base) then
6832 Set_Discriminant_Constraint
6833 (Full, Discriminant_Constraint (Full_Base));
6837 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6838 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6840 -- Freeze the private subtype entity if its parent is delayed,
6841 -- and not already frozen. We skip this processing if the type
6842 -- is an anonymous subtype of a record component, or is the
6843 -- corresponding record of a protected type, since ???
6845 if not Is_Type (Scope (Full)) then
6846 Set_Has_Delayed_Freeze (Full,
6847 Has_Delayed_Freeze (Full_Base)
6848 and then (not Is_Frozen (Full_Base)));
6851 Set_Freeze_Node (Full, Empty);
6852 Set_Is_Frozen (Full, False);
6853 Set_Full_View (Priv, Full);
6855 if Has_Discriminants (Full) then
6856 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
6857 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
6858 if Has_Unknown_Discriminants (Full) then
6859 Set_Discriminant_Constraint (Full, No_Elist);
6863 if Ekind (Full_Base) = E_Record_Type
6864 and then Has_Discriminants (Full_Base)
6865 and then Has_Discriminants (Priv) -- might not, if errors
6866 and then not Has_Unknown_Discriminants (Priv)
6867 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
6869 Create_Constrained_Components
6870 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
6872 -- If the full base is itself derived from private, build a congruent
6873 -- subtype of its underlying type, for use by the back end. Do not
6874 -- do this for a constrained record component, where the back-end has
6875 -- the proper information and there is no place for the declaration.
6877 elsif Ekind (Full_Base) in Private_Kind
6878 and then Is_Derived_Type (Full_Base)
6879 and then Has_Discriminants (Full_Base)
6880 and then Nkind (Related_Nod) /= N_Component_Declaration
6881 and then (Ekind (Current_Scope) /= E_Record_Subtype)
6883 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
6885 Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
6887 elsif Is_Record_Type (Full_Base) then
6889 -- Show Full is simply a renaming of Full_Base.
6891 Set_Cloned_Subtype (Full, Full_Base);
6894 -- It is unsafe to share to bounds of a scalar type, because the
6895 -- Itype is elaborated on demand, and if a bound is non-static
6896 -- then different orders of elaboration in different units will
6897 -- lead to different external symbols.
6899 if Is_Scalar_Type (Full_Base) then
6900 Set_Scalar_Range (Full,
6901 Make_Range (Sloc (Related_Nod),
6903 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
6905 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
6907 -- This completion inherits the bounds of the full parent, but if
6908 -- the parent is an unconstrained floating point type, so is the
6911 if Is_Floating_Point_Type (Full_Base) then
6912 Set_Includes_Infinities
6913 (Scalar_Range (Full), Has_Infinities (Full_Base));
6917 -- ??? It seems that a lot of fields are missing that should be
6918 -- copied from Full_Base to Full. Here are some that are introduced
6919 -- in a non-disruptive way but a cleanup is necessary.
6921 if Is_Tagged_Type (Full_Base) then
6922 Set_Is_Tagged_Type (Full);
6923 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
6924 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
6926 elsif Is_Concurrent_Type (Full_Base) then
6927 if Has_Discriminants (Full)
6928 and then Present (Corresponding_Record_Type (Full_Base))
6930 Set_Corresponding_Record_Type (Full,
6931 Constrain_Corresponding_Record
6932 (Full, Corresponding_Record_Type (Full_Base),
6933 Related_Nod, Full_Base));
6936 Set_Corresponding_Record_Type (Full,
6937 Corresponding_Record_Type (Full_Base));
6941 end Complete_Private_Subtype;
6943 ----------------------------
6944 -- Constant_Redeclaration --
6945 ----------------------------
6947 procedure Constant_Redeclaration
6952 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
6953 Obj_Def : constant Node_Id := Object_Definition (N);
6956 procedure Check_Recursive_Declaration (Typ : Entity_Id);
6957 -- If deferred constant is an access type initialized with an
6958 -- allocator, check whether there is an illegal recursion in the
6959 -- definition, through a default value of some record subcomponent.
6960 -- This is normally detected when generating init procs, but requires
6961 -- this additional mechanism when expansion is disabled.
6963 ---------------------------------
6964 -- Check_Recursive_Declaration --
6965 ---------------------------------
6967 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
6971 if Is_Record_Type (Typ) then
6972 Comp := First_Component (Typ);
6974 while Present (Comp) loop
6975 if Comes_From_Source (Comp) then
6976 if Present (Expression (Parent (Comp)))
6977 and then Is_Entity_Name (Expression (Parent (Comp)))
6978 and then Entity (Expression (Parent (Comp))) = Prev
6980 Error_Msg_Sloc := Sloc (Parent (Comp));
6982 ("illegal circularity with declaration for&#",
6986 elsif Is_Record_Type (Etype (Comp)) then
6987 Check_Recursive_Declaration (Etype (Comp));
6991 Next_Component (Comp);
6994 end Check_Recursive_Declaration;
6996 -- Start of processing for Constant_Redeclaration
6999 if Nkind (Parent (Prev)) = N_Object_Declaration then
7000 if Nkind (Object_Definition
7001 (Parent (Prev))) = N_Subtype_Indication
7003 -- Find type of new declaration. The constraints of the two
7004 -- views must match statically, but there is no point in
7005 -- creating an itype for the full view.
7007 if Nkind (Obj_Def) = N_Subtype_Indication then
7008 Find_Type (Subtype_Mark (Obj_Def));
7009 New_T := Entity (Subtype_Mark (Obj_Def));
7012 Find_Type (Obj_Def);
7013 New_T := Entity (Obj_Def);
7019 -- The full view may impose a constraint, even if the partial
7020 -- view does not, so construct the subtype.
7022 New_T := Find_Type_Of_Object (Obj_Def, N);
7027 -- Current declaration is illegal, diagnosed below in Enter_Name.
7033 -- If previous full declaration exists, or if a homograph is present,
7034 -- let Enter_Name handle it, either with an error, or with the removal
7035 -- of an overridden implicit subprogram.
7037 if Ekind (Prev) /= E_Constant
7038 or else Present (Expression (Parent (Prev)))
7039 or else Present (Full_View (Prev))
7043 -- Verify that types of both declarations match.
7045 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
7046 Error_Msg_Sloc := Sloc (Prev);
7047 Error_Msg_N ("type does not match declaration#", N);
7048 Set_Full_View (Prev, Id);
7049 Set_Etype (Id, Any_Type);
7051 -- If so, process the full constant declaration
7054 Set_Full_View (Prev, Id);
7055 Set_Is_Public (Id, Is_Public (Prev));
7056 Set_Is_Internal (Id);
7057 Append_Entity (Id, Current_Scope);
7059 -- Check ALIASED present if present before (RM 7.4(7))
7061 if Is_Aliased (Prev)
7062 and then not Aliased_Present (N)
7064 Error_Msg_Sloc := Sloc (Prev);
7065 Error_Msg_N ("ALIASED required (see declaration#)", N);
7068 -- Check that placement is in private part and that the incomplete
7069 -- declaration appeared in the visible part.
7071 if Ekind (Current_Scope) = E_Package
7072 and then not In_Private_Part (Current_Scope)
7074 Error_Msg_Sloc := Sloc (Prev);
7075 Error_Msg_N ("full constant for declaration#"
7076 & " must be in private part", N);
7078 elsif Ekind (Current_Scope) = E_Package
7079 and then List_Containing (Parent (Prev))
7080 /= Visible_Declarations
7081 (Specification (Unit_Declaration_Node (Current_Scope)))
7084 ("deferred constant must be declared in visible part",
7088 if Is_Access_Type (T)
7089 and then Nkind (Expression (N)) = N_Allocator
7091 Check_Recursive_Declaration (Designated_Type (T));
7094 end Constant_Redeclaration;
7096 ----------------------
7097 -- Constrain_Access --
7098 ----------------------
7100 procedure Constrain_Access
7101 (Def_Id : in out Entity_Id;
7103 Related_Nod : Node_Id)
7105 T : constant Entity_Id := Entity (Subtype_Mark (S));
7106 Desig_Type : constant Entity_Id := Designated_Type (T);
7107 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
7108 Constraint_OK : Boolean := True;
7111 if Is_Array_Type (Desig_Type) then
7112 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
7114 elsif (Is_Record_Type (Desig_Type)
7115 or else Is_Incomplete_Or_Private_Type (Desig_Type))
7116 and then not Is_Constrained (Desig_Type)
7118 -- ??? The following code is a temporary kludge to ignore
7119 -- discriminant constraint on access type if
7120 -- it is constraining the current record. Avoid creating the
7121 -- implicit subtype of the record we are currently compiling
7122 -- since right now, we cannot handle these.
7123 -- For now, just return the access type itself.
7125 if Desig_Type = Current_Scope
7126 and then No (Def_Id)
7128 Set_Ekind (Desig_Subtype, E_Record_Subtype);
7129 Def_Id := Entity (Subtype_Mark (S));
7131 -- This call added to ensure that the constraint is
7132 -- analyzed (needed for a B test). Note that we
7133 -- still return early from this procedure to avoid
7134 -- recursive processing. ???
7136 Constrain_Discriminated_Type
7137 (Desig_Subtype, S, Related_Nod, For_Access => True);
7142 if Ekind (T) = E_General_Access_Type
7143 and then Has_Private_Declaration (Desig_Type)
7144 and then In_Open_Scopes (Scope (Desig_Type))
7146 -- Enforce rule that the constraint is illegal if there is
7147 -- an unconstrained view of the designated type. This means
7148 -- that the partial view (either a private type declaration or
7149 -- a derivation from a private type) has no discriminants.
7150 -- (Defect Report 8652/0008, Technical Corrigendum 1, checked
7151 -- by ACATS B371001).
7154 Pack : constant Node_Id :=
7155 Unit_Declaration_Node (Scope (Desig_Type));
7160 if Nkind (Pack) = N_Package_Declaration then
7161 Decls := Visible_Declarations (Specification (Pack));
7162 Decl := First (Decls);
7164 while Present (Decl) loop
7165 if (Nkind (Decl) = N_Private_Type_Declaration
7167 Chars (Defining_Identifier (Decl)) =
7171 (Nkind (Decl) = N_Full_Type_Declaration
7173 Chars (Defining_Identifier (Decl)) =
7175 and then Is_Derived_Type (Desig_Type)
7177 Has_Private_Declaration (Etype (Desig_Type)))
7179 if No (Discriminant_Specifications (Decl)) then
7181 ("cannot constrain general access type " &
7182 "if designated type has unconstrained view", S);
7194 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
7195 For_Access => True);
7197 elsif (Is_Task_Type (Desig_Type)
7198 or else Is_Protected_Type (Desig_Type))
7199 and then not Is_Constrained (Desig_Type)
7201 Constrain_Concurrent
7202 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
7205 Error_Msg_N ("invalid constraint on access type", S);
7206 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
7207 Constraint_OK := False;
7211 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
7213 Set_Ekind (Def_Id, E_Access_Subtype);
7216 if Constraint_OK then
7217 Set_Etype (Def_Id, Base_Type (T));
7219 if Is_Private_Type (Desig_Type) then
7220 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
7223 Set_Etype (Def_Id, Any_Type);
7226 Set_Size_Info (Def_Id, T);
7227 Set_Is_Constrained (Def_Id, Constraint_OK);
7228 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
7229 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7230 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
7232 -- Itypes created for constrained record components do not receive
7233 -- a freeze node, they are elaborated when first seen.
7235 if not Is_Record_Type (Current_Scope) then
7236 Conditional_Delay (Def_Id, T);
7238 end Constrain_Access;
7240 ---------------------
7241 -- Constrain_Array --
7242 ---------------------
7244 procedure Constrain_Array
7245 (Def_Id : in out Entity_Id;
7247 Related_Nod : Node_Id;
7248 Related_Id : Entity_Id;
7251 C : constant Node_Id := Constraint (SI);
7252 Number_Of_Constraints : Nat := 0;
7255 Constraint_OK : Boolean := True;
7258 T := Entity (Subtype_Mark (SI));
7260 if Ekind (T) in Access_Kind then
7261 T := Designated_Type (T);
7264 -- If an index constraint follows a subtype mark in a subtype indication
7265 -- then the type or subtype denoted by the subtype mark must not already
7266 -- impose an index constraint. The subtype mark must denote either an
7267 -- unconstrained array type or an access type whose designated type
7268 -- is such an array type... (RM 3.6.1)
7270 if Is_Constrained (T) then
7272 ("array type is already constrained", Subtype_Mark (SI));
7273 Constraint_OK := False;
7276 S := First (Constraints (C));
7278 while Present (S) loop
7279 Number_Of_Constraints := Number_Of_Constraints + 1;
7283 -- In either case, the index constraint must provide a discrete
7284 -- range for each index of the array type and the type of each
7285 -- discrete range must be the same as that of the corresponding
7286 -- index. (RM 3.6.1)
7288 if Number_Of_Constraints /= Number_Dimensions (T) then
7289 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
7290 Constraint_OK := False;
7293 S := First (Constraints (C));
7294 Index := First_Index (T);
7297 -- Apply constraints to each index type
7299 for J in 1 .. Number_Of_Constraints loop
7300 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
7310 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
7311 Set_Parent (Def_Id, Related_Nod);
7314 Set_Ekind (Def_Id, E_Array_Subtype);
7317 Set_Size_Info (Def_Id, (T));
7318 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7319 Set_Etype (Def_Id, Base_Type (T));
7321 if Constraint_OK then
7322 Set_First_Index (Def_Id, First (Constraints (C)));
7325 Set_Is_Constrained (Def_Id, True);
7326 Set_Is_Aliased (Def_Id, Is_Aliased (T));
7327 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7329 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
7330 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
7332 -- If the subtype is not that of a record component, build a freeze
7333 -- node if parent still needs one.
7335 -- If the subtype is not that of a record component, make sure
7336 -- that the Depends_On_Private status is set (explanation ???)
7337 -- and also that a conditional delay is set.
7339 if not Is_Type (Scope (Def_Id)) then
7340 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
7341 Conditional_Delay (Def_Id, T);
7344 end Constrain_Array;
7346 ------------------------------
7347 -- Constrain_Component_Type --
7348 ------------------------------
7350 function Constrain_Component_Type
7351 (Compon_Type : Entity_Id;
7352 Constrained_Typ : Entity_Id;
7353 Related_Node : Node_Id;
7355 Constraints : Elist_Id) return Entity_Id
7357 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
7359 function Build_Constrained_Array_Type
7360 (Old_Type : Entity_Id) return Entity_Id;
7361 -- If Old_Type is an array type, one of whose indices is
7362 -- constrained by a discriminant, build an Itype whose constraint
7363 -- replaces the discriminant with its value in the constraint.
7365 function Build_Constrained_Discriminated_Type
7366 (Old_Type : Entity_Id) return Entity_Id;
7367 -- Ditto for record components.
7369 function Build_Constrained_Access_Type
7370 (Old_Type : Entity_Id) return Entity_Id;
7371 -- Ditto for access types. Makes use of previous two functions, to
7372 -- constrain designated type.
7374 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
7375 -- T is an array or discriminated type, C is a list of constraints
7376 -- that apply to T. This routine builds the constrained subtype.
7378 function Is_Discriminant (Expr : Node_Id) return Boolean;
7379 -- Returns True if Expr is a discriminant.
7381 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
7382 -- Find the value of discriminant Discrim in Constraint.
7384 -----------------------------------
7385 -- Build_Constrained_Access_Type --
7386 -----------------------------------
7388 function Build_Constrained_Access_Type
7389 (Old_Type : Entity_Id) return Entity_Id
7391 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
7393 Desig_Subtype : Entity_Id;
7397 -- if the original access type was not embedded in the enclosing
7398 -- type definition, there is no need to produce a new access
7399 -- subtype. In fact every access type with an explicit constraint
7400 -- generates an itype whose scope is the enclosing record.
7402 if not Is_Type (Scope (Old_Type)) then
7405 elsif Is_Array_Type (Desig_Type) then
7406 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
7408 elsif Has_Discriminants (Desig_Type) then
7410 -- This may be an access type to an enclosing record type for
7411 -- which we are constructing the constrained components. Return
7412 -- the enclosing record subtype. This is not always correct,
7413 -- but avoids infinite recursion. ???
7415 Desig_Subtype := Any_Type;
7417 for J in reverse 0 .. Scope_Stack.Last loop
7418 Scop := Scope_Stack.Table (J).Entity;
7421 and then Base_Type (Scop) = Base_Type (Desig_Type)
7423 Desig_Subtype := Scop;
7426 exit when not Is_Type (Scop);
7429 if Desig_Subtype = Any_Type then
7431 Build_Constrained_Discriminated_Type (Desig_Type);
7438 if Desig_Subtype /= Desig_Type then
7439 -- The Related_Node better be here or else we won't be able
7440 -- to attach new itypes to a node in the tree.
7442 pragma Assert (Present (Related_Node));
7444 Itype := Create_Itype (E_Access_Subtype, Related_Node);
7446 Set_Etype (Itype, Base_Type (Old_Type));
7447 Set_Size_Info (Itype, (Old_Type));
7448 Set_Directly_Designated_Type (Itype, Desig_Subtype);
7449 Set_Depends_On_Private (Itype, Has_Private_Component
7451 Set_Is_Access_Constant (Itype, Is_Access_Constant
7454 -- The new itype needs freezing when it depends on a not frozen
7455 -- type and the enclosing subtype needs freezing.
7457 if Has_Delayed_Freeze (Constrained_Typ)
7458 and then not Is_Frozen (Constrained_Typ)
7460 Conditional_Delay (Itype, Base_Type (Old_Type));
7468 end Build_Constrained_Access_Type;
7470 ----------------------------------
7471 -- Build_Constrained_Array_Type --
7472 ----------------------------------
7474 function Build_Constrained_Array_Type
7475 (Old_Type : Entity_Id) return Entity_Id
7479 Old_Index : Node_Id;
7480 Range_Node : Node_Id;
7481 Constr_List : List_Id;
7483 Need_To_Create_Itype : Boolean := False;
7486 Old_Index := First_Index (Old_Type);
7487 while Present (Old_Index) loop
7488 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
7490 if Is_Discriminant (Lo_Expr)
7491 or else Is_Discriminant (Hi_Expr)
7493 Need_To_Create_Itype := True;
7496 Next_Index (Old_Index);
7499 if Need_To_Create_Itype then
7500 Constr_List := New_List;
7502 Old_Index := First_Index (Old_Type);
7503 while Present (Old_Index) loop
7504 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
7506 if Is_Discriminant (Lo_Expr) then
7507 Lo_Expr := Get_Discr_Value (Lo_Expr);
7510 if Is_Discriminant (Hi_Expr) then
7511 Hi_Expr := Get_Discr_Value (Hi_Expr);
7516 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
7518 Append (Range_Node, To => Constr_List);
7520 Next_Index (Old_Index);
7523 return Build_Subtype (Old_Type, Constr_List);
7528 end Build_Constrained_Array_Type;
7530 ------------------------------------------
7531 -- Build_Constrained_Discriminated_Type --
7532 ------------------------------------------
7534 function Build_Constrained_Discriminated_Type
7535 (Old_Type : Entity_Id) return Entity_Id
7538 Constr_List : List_Id;
7539 Old_Constraint : Elmt_Id;
7541 Need_To_Create_Itype : Boolean := False;
7544 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
7545 while Present (Old_Constraint) loop
7546 Expr := Node (Old_Constraint);
7548 if Is_Discriminant (Expr) then
7549 Need_To_Create_Itype := True;
7552 Next_Elmt (Old_Constraint);
7555 if Need_To_Create_Itype then
7556 Constr_List := New_List;
7558 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
7559 while Present (Old_Constraint) loop
7560 Expr := Node (Old_Constraint);
7562 if Is_Discriminant (Expr) then
7563 Expr := Get_Discr_Value (Expr);
7566 Append (New_Copy_Tree (Expr), To => Constr_List);
7568 Next_Elmt (Old_Constraint);
7571 return Build_Subtype (Old_Type, Constr_List);
7576 end Build_Constrained_Discriminated_Type;
7582 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
7584 Subtyp_Decl : Node_Id;
7586 Btyp : Entity_Id := Base_Type (T);
7589 -- The Related_Node better be here or else we won't be able
7590 -- to attach new itypes to a node in the tree.
7592 pragma Assert (Present (Related_Node));
7594 -- If the view of the component's type is incomplete or private
7595 -- with unknown discriminants, then the constraint must be applied
7596 -- to the full type.
7598 if Has_Unknown_Discriminants (Btyp)
7599 and then Present (Underlying_Type (Btyp))
7601 Btyp := Underlying_Type (Btyp);
7605 Make_Subtype_Indication (Loc,
7606 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
7607 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
7609 Def_Id := Create_Itype (Ekind (T), Related_Node);
7612 Make_Subtype_Declaration (Loc,
7613 Defining_Identifier => Def_Id,
7614 Subtype_Indication => Indic);
7616 Set_Parent (Subtyp_Decl, Parent (Related_Node));
7618 -- Itypes must be analyzed with checks off (see itypes.ads).
7620 Analyze (Subtyp_Decl, Suppress => All_Checks);
7625 ---------------------
7626 -- Get_Discr_Value --
7627 ---------------------
7629 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
7630 D : Entity_Id := First_Discriminant (Typ);
7631 E : Elmt_Id := First_Elmt (Constraints);
7635 -- The discriminant may be declared for the type, in which case we
7636 -- find it by iterating over the list of discriminants. If the
7637 -- discriminant is inherited from a parent type, it appears as the
7638 -- corresponding discriminant of the current type. This will be the
7639 -- case when constraining an inherited component whose constraint is
7640 -- given by a discriminant of the parent.
7642 while Present (D) loop
7643 if D = Entity (Discrim)
7644 or else Corresponding_Discriminant (D) = Entity (Discrim)
7649 Next_Discriminant (D);
7653 -- The corresponding_Discriminant mechanism is incomplete, because
7654 -- the correspondence between new and old discriminants is not one
7655 -- to one: one new discriminant can constrain several old ones.
7656 -- In that case, scan sequentially the stored_constraint, the list
7657 -- of discriminants of the parents, and the constraints.
7659 if Is_Derived_Type (Typ)
7660 and then Present (Stored_Constraint (Typ))
7661 and then Scope (Entity (Discrim)) = Etype (Typ)
7663 D := First_Discriminant (Etype (Typ));
7664 E := First_Elmt (Constraints);
7665 G := First_Elmt (Stored_Constraint (Typ));
7667 while Present (D) loop
7668 if D = Entity (Discrim) then
7672 Next_Discriminant (D);
7678 -- Something is wrong if we did not find the value
7680 raise Program_Error;
7681 end Get_Discr_Value;
7683 ---------------------
7684 -- Is_Discriminant --
7685 ---------------------
7687 function Is_Discriminant (Expr : Node_Id) return Boolean is
7688 Discrim_Scope : Entity_Id;
7691 if Denotes_Discriminant (Expr) then
7692 Discrim_Scope := Scope (Entity (Expr));
7694 -- Either we have a reference to one of Typ's discriminants,
7696 pragma Assert (Discrim_Scope = Typ
7698 -- or to the discriminants of the parent type, in the case
7699 -- of a derivation of a tagged type with variants.
7701 or else Discrim_Scope = Etype (Typ)
7702 or else Full_View (Discrim_Scope) = Etype (Typ)
7704 -- or same as above for the case where the discriminants
7705 -- were declared in Typ's private view.
7707 or else (Is_Private_Type (Discrim_Scope)
7708 and then Chars (Discrim_Scope) = Chars (Typ))
7710 -- or else we are deriving from the full view and the
7711 -- discriminant is declared in the private entity.
7713 or else (Is_Private_Type (Typ)
7714 and then Chars (Discrim_Scope) = Chars (Typ))
7716 -- or we have a class-wide type, in which case make sure the
7717 -- discriminant found belongs to the root type.
7719 or else (Is_Class_Wide_Type (Typ)
7720 and then Etype (Typ) = Discrim_Scope));
7725 -- In all other cases we have something wrong.
7728 end Is_Discriminant;
7730 -- Start of processing for Constrain_Component_Type
7733 if Is_Array_Type (Compon_Type) then
7734 return Build_Constrained_Array_Type (Compon_Type);
7736 elsif Has_Discriminants (Compon_Type) then
7737 return Build_Constrained_Discriminated_Type (Compon_Type);
7739 elsif Is_Access_Type (Compon_Type) then
7740 return Build_Constrained_Access_Type (Compon_Type);
7744 end Constrain_Component_Type;
7746 --------------------------
7747 -- Constrain_Concurrent --
7748 --------------------------
7750 -- For concurrent types, the associated record value type carries the same
7751 -- discriminants, so when we constrain a concurrent type, we must constrain
7752 -- the value type as well.
7754 procedure Constrain_Concurrent
7755 (Def_Id : in out Entity_Id;
7757 Related_Nod : Node_Id;
7758 Related_Id : Entity_Id;
7761 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
7765 if Ekind (T_Ent) in Access_Kind then
7766 T_Ent := Designated_Type (T_Ent);
7769 T_Val := Corresponding_Record_Type (T_Ent);
7771 if Present (T_Val) then
7774 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7777 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7779 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
7780 Set_Corresponding_Record_Type (Def_Id,
7781 Constrain_Corresponding_Record
7782 (Def_Id, T_Val, Related_Nod, Related_Id));
7785 -- If there is no associated record, expansion is disabled and this
7786 -- is a generic context. Create a subtype in any case, so that
7787 -- semantic analysis can proceed.
7790 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
7793 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
7795 end Constrain_Concurrent;
7797 ------------------------------------
7798 -- Constrain_Corresponding_Record --
7799 ------------------------------------
7801 function Constrain_Corresponding_Record
7802 (Prot_Subt : Entity_Id;
7803 Corr_Rec : Entity_Id;
7804 Related_Nod : Node_Id;
7805 Related_Id : Entity_Id) return Entity_Id
7807 T_Sub : constant Entity_Id
7808 := Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
7811 Set_Etype (T_Sub, Corr_Rec);
7812 Init_Size_Align (T_Sub);
7813 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
7814 Set_Is_Constrained (T_Sub, True);
7815 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
7816 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
7818 Conditional_Delay (T_Sub, Corr_Rec);
7820 if Has_Discriminants (Prot_Subt) then -- False only if errors.
7821 Set_Discriminant_Constraint (T_Sub,
7822 Discriminant_Constraint (Prot_Subt));
7823 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
7824 Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
7825 Discriminant_Constraint (T_Sub));
7828 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
7831 end Constrain_Corresponding_Record;
7833 -----------------------
7834 -- Constrain_Decimal --
7835 -----------------------
7837 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
7838 T : constant Entity_Id := Entity (Subtype_Mark (S));
7839 C : constant Node_Id := Constraint (S);
7840 Loc : constant Source_Ptr := Sloc (C);
7841 Range_Expr : Node_Id;
7842 Digits_Expr : Node_Id;
7847 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7849 if Nkind (C) = N_Range_Constraint then
7850 Range_Expr := Range_Expression (C);
7851 Digits_Val := Digits_Value (T);
7854 pragma Assert (Nkind (C) = N_Digits_Constraint);
7855 Digits_Expr := Digits_Expression (C);
7856 Analyze_And_Resolve (Digits_Expr, Any_Integer);
7858 Check_Digits_Expression (Digits_Expr);
7859 Digits_Val := Expr_Value (Digits_Expr);
7861 if Digits_Val > Digits_Value (T) then
7863 ("digits expression is incompatible with subtype", C);
7864 Digits_Val := Digits_Value (T);
7867 if Present (Range_Constraint (C)) then
7868 Range_Expr := Range_Expression (Range_Constraint (C));
7870 Range_Expr := Empty;
7874 Set_Etype (Def_Id, Base_Type (T));
7875 Set_Size_Info (Def_Id, (T));
7876 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7877 Set_Delta_Value (Def_Id, Delta_Value (T));
7878 Set_Scale_Value (Def_Id, Scale_Value (T));
7879 Set_Small_Value (Def_Id, Small_Value (T));
7880 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
7881 Set_Digits_Value (Def_Id, Digits_Val);
7883 -- Manufacture range from given digits value if no range present
7885 if No (Range_Expr) then
7886 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
7890 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
7892 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
7896 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
7897 Set_Discrete_RM_Size (Def_Id);
7899 -- Unconditionally delay the freeze, since we cannot set size
7900 -- information in all cases correctly until the freeze point.
7902 Set_Has_Delayed_Freeze (Def_Id);
7903 end Constrain_Decimal;
7905 ----------------------------------
7906 -- Constrain_Discriminated_Type --
7907 ----------------------------------
7909 procedure Constrain_Discriminated_Type
7910 (Def_Id : Entity_Id;
7912 Related_Nod : Node_Id;
7913 For_Access : Boolean := False)
7915 E : constant Entity_Id := Entity (Subtype_Mark (S));
7918 Elist : Elist_Id := New_Elmt_List;
7920 procedure Fixup_Bad_Constraint;
7921 -- This is called after finding a bad constraint, and after having
7922 -- posted an appropriate error message. The mission is to leave the
7923 -- entity T in as reasonable state as possible!
7925 --------------------------
7926 -- Fixup_Bad_Constraint --
7927 --------------------------
7929 procedure Fixup_Bad_Constraint is
7931 -- Set a reasonable Ekind for the entity. For an incomplete type,
7932 -- we can't do much, but for other types, we can set the proper
7933 -- corresponding subtype kind.
7935 if Ekind (T) = E_Incomplete_Type then
7936 Set_Ekind (Def_Id, Ekind (T));
7938 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
7941 Set_Etype (Def_Id, Any_Type);
7942 Set_Error_Posted (Def_Id);
7943 end Fixup_Bad_Constraint;
7945 -- Start of processing for Constrain_Discriminated_Type
7948 C := Constraint (S);
7950 -- A discriminant constraint is only allowed in a subtype indication,
7951 -- after a subtype mark. This subtype mark must denote either a type
7952 -- with discriminants, or an access type whose designated type is a
7953 -- type with discriminants. A discriminant constraint specifies the
7954 -- values of these discriminants (RM 3.7.2(5)).
7956 T := Base_Type (Entity (Subtype_Mark (S)));
7958 if Ekind (T) in Access_Kind then
7959 T := Designated_Type (T);
7962 -- Check that the type has visible discriminants. The type may be
7963 -- a private type with unknown discriminants whose full view has
7964 -- discriminants which are invisible.
7966 if not Has_Discriminants (T)
7968 (Has_Unknown_Discriminants (T)
7969 and then Is_Private_Type (T))
7971 Error_Msg_N ("invalid constraint: type has no discriminant", C);
7972 Fixup_Bad_Constraint;
7975 elsif Is_Constrained (E)
7976 or else (Ekind (E) = E_Class_Wide_Subtype
7977 and then Present (Discriminant_Constraint (E)))
7979 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
7980 Fixup_Bad_Constraint;
7984 -- T may be an unconstrained subtype (e.g. a generic actual).
7985 -- Constraint applies to the base type.
7989 Elist := Build_Discriminant_Constraints (T, S);
7991 -- If the list returned was empty we had an error in building the
7992 -- discriminant constraint. We have also already signalled an error
7993 -- in the incomplete type case
7995 if Is_Empty_Elmt_List (Elist) then
7996 Fixup_Bad_Constraint;
8000 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
8001 end Constrain_Discriminated_Type;
8003 ---------------------------
8004 -- Constrain_Enumeration --
8005 ---------------------------
8007 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
8008 T : constant Entity_Id := Entity (Subtype_Mark (S));
8009 C : constant Node_Id := Constraint (S);
8012 Set_Ekind (Def_Id, E_Enumeration_Subtype);
8014 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
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_Is_Character_Type (Def_Id, Is_Character_Type (T));
8021 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8023 Set_Discrete_RM_Size (Def_Id);
8025 end Constrain_Enumeration;
8027 ----------------------
8028 -- Constrain_Float --
8029 ----------------------
8031 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
8032 T : constant Entity_Id := Entity (Subtype_Mark (S));
8038 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
8040 Set_Etype (Def_Id, Base_Type (T));
8041 Set_Size_Info (Def_Id, (T));
8042 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8044 -- Process the constraint
8046 C := Constraint (S);
8048 -- Digits constraint present
8050 if Nkind (C) = N_Digits_Constraint then
8051 if Warn_On_Obsolescent_Feature then
8053 ("subtype digits constraint is an " &
8054 "obsolescent feature ('R'M 'J.3(8))?", C);
8057 D := Digits_Expression (C);
8058 Analyze_And_Resolve (D, Any_Integer);
8059 Check_Digits_Expression (D);
8060 Set_Digits_Value (Def_Id, Expr_Value (D));
8062 -- Check that digits value is in range. Obviously we can do this
8063 -- at compile time, but it is strictly a runtime check, and of
8064 -- course there is an ACVC test that checks this!
8066 if Digits_Value (Def_Id) > Digits_Value (T) then
8067 Error_Msg_Uint_1 := Digits_Value (T);
8068 Error_Msg_N ("?digits value is too large, maximum is ^", D);
8070 Make_Raise_Constraint_Error (Sloc (D),
8071 Reason => CE_Range_Check_Failed);
8072 Insert_Action (Declaration_Node (Def_Id), Rais);
8075 C := Range_Constraint (C);
8077 -- No digits constraint present
8080 Set_Digits_Value (Def_Id, Digits_Value (T));
8083 -- Range constraint present
8085 if Nkind (C) = N_Range_Constraint then
8086 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8088 -- No range constraint present
8091 pragma Assert (No (C));
8092 Set_Scalar_Range (Def_Id, Scalar_Range (T));
8095 Set_Is_Constrained (Def_Id);
8096 end Constrain_Float;
8098 ---------------------
8099 -- Constrain_Index --
8100 ---------------------
8102 procedure Constrain_Index
8105 Related_Nod : Node_Id;
8106 Related_Id : Entity_Id;
8111 R : Node_Id := Empty;
8112 T : constant Entity_Id := Etype (Index);
8115 if Nkind (S) = N_Range
8117 (Nkind (S) = N_Attribute_Reference
8118 and then Attribute_Name (S) = Name_Range)
8120 -- A Range attribute will transformed into N_Range by Resolve.
8126 Process_Range_Expr_In_Decl (R, T, Empty_List);
8128 if not Error_Posted (S)
8130 (Nkind (S) /= N_Range
8131 or else not Covers (T, (Etype (Low_Bound (S))))
8132 or else not Covers (T, (Etype (High_Bound (S)))))
8134 if Base_Type (T) /= Any_Type
8135 and then Etype (Low_Bound (S)) /= Any_Type
8136 and then Etype (High_Bound (S)) /= Any_Type
8138 Error_Msg_N ("range expected", S);
8142 elsif Nkind (S) = N_Subtype_Indication then
8143 -- the parser has verified that this is a discrete indication.
8145 Resolve_Discrete_Subtype_Indication (S, T);
8146 R := Range_Expression (Constraint (S));
8148 elsif Nkind (S) = N_Discriminant_Association then
8150 -- syntactically valid in subtype indication.
8152 Error_Msg_N ("invalid index constraint", S);
8153 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
8156 -- Subtype_Mark case, no anonymous subtypes to construct
8161 if Is_Entity_Name (S) then
8163 if not Is_Type (Entity (S)) then
8164 Error_Msg_N ("expect subtype mark for index constraint", S);
8166 elsif Base_Type (Entity (S)) /= Base_Type (T) then
8167 Wrong_Type (S, Base_Type (T));
8173 Error_Msg_N ("invalid index constraint", S);
8174 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
8180 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
8182 Set_Etype (Def_Id, Base_Type (T));
8184 if Is_Modular_Integer_Type (T) then
8185 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
8187 elsif Is_Integer_Type (T) then
8188 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
8191 Set_Ekind (Def_Id, E_Enumeration_Subtype);
8192 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
8195 Set_Size_Info (Def_Id, (T));
8196 Set_RM_Size (Def_Id, RM_Size (T));
8197 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8199 Set_Scalar_Range (Def_Id, R);
8201 Set_Etype (S, Def_Id);
8202 Set_Discrete_RM_Size (Def_Id);
8203 end Constrain_Index;
8205 -----------------------
8206 -- Constrain_Integer --
8207 -----------------------
8209 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
8210 T : constant Entity_Id := Entity (Subtype_Mark (S));
8211 C : constant Node_Id := Constraint (S);
8214 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8216 if Is_Modular_Integer_Type (T) then
8217 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
8219 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
8222 Set_Etype (Def_Id, Base_Type (T));
8223 Set_Size_Info (Def_Id, (T));
8224 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8225 Set_Discrete_RM_Size (Def_Id);
8227 end Constrain_Integer;
8229 ------------------------------
8230 -- Constrain_Ordinary_Fixed --
8231 ------------------------------
8233 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
8234 T : constant Entity_Id := Entity (Subtype_Mark (S));
8240 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
8241 Set_Etype (Def_Id, Base_Type (T));
8242 Set_Size_Info (Def_Id, (T));
8243 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8244 Set_Small_Value (Def_Id, Small_Value (T));
8246 -- Process the constraint
8248 C := Constraint (S);
8250 -- Delta constraint present
8252 if Nkind (C) = N_Delta_Constraint then
8253 if Warn_On_Obsolescent_Feature then
8255 ("subtype delta constraint is an " &
8256 "obsolescent feature ('R'M 'J.3(7))?");
8259 D := Delta_Expression (C);
8260 Analyze_And_Resolve (D, Any_Real);
8261 Check_Delta_Expression (D);
8262 Set_Delta_Value (Def_Id, Expr_Value_R (D));
8264 -- Check that delta value is in range. Obviously we can do this
8265 -- at compile time, but it is strictly a runtime check, and of
8266 -- course there is an ACVC test that checks this!
8268 if Delta_Value (Def_Id) < Delta_Value (T) then
8269 Error_Msg_N ("?delta value is too small", D);
8271 Make_Raise_Constraint_Error (Sloc (D),
8272 Reason => CE_Range_Check_Failed);
8273 Insert_Action (Declaration_Node (Def_Id), Rais);
8276 C := Range_Constraint (C);
8278 -- No delta constraint present
8281 Set_Delta_Value (Def_Id, Delta_Value (T));
8284 -- Range constraint present
8286 if Nkind (C) = N_Range_Constraint then
8287 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
8289 -- No range constraint present
8292 pragma Assert (No (C));
8293 Set_Scalar_Range (Def_Id, Scalar_Range (T));
8297 Set_Discrete_RM_Size (Def_Id);
8299 -- Unconditionally delay the freeze, since we cannot set size
8300 -- information in all cases correctly until the freeze point.
8302 Set_Has_Delayed_Freeze (Def_Id);
8303 end Constrain_Ordinary_Fixed;
8305 ---------------------------
8306 -- Convert_Scalar_Bounds --
8307 ---------------------------
8309 procedure Convert_Scalar_Bounds
8311 Parent_Type : Entity_Id;
8312 Derived_Type : Entity_Id;
8315 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
8322 Lo := Build_Scalar_Bound
8323 (Type_Low_Bound (Derived_Type),
8324 Parent_Type, Implicit_Base);
8326 Hi := Build_Scalar_Bound
8327 (Type_High_Bound (Derived_Type),
8328 Parent_Type, Implicit_Base);
8335 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
8337 Set_Parent (Rng, N);
8338 Set_Scalar_Range (Derived_Type, Rng);
8340 -- Analyze the bounds
8342 Analyze_And_Resolve (Lo, Implicit_Base);
8343 Analyze_And_Resolve (Hi, Implicit_Base);
8345 -- Analyze the range itself, except that we do not analyze it if
8346 -- the bounds are real literals, and we have a fixed-point type.
8347 -- The reason for this is that we delay setting the bounds in this
8348 -- case till we know the final Small and Size values (see circuit
8349 -- in Freeze.Freeze_Fixed_Point_Type for further details).
8351 if Is_Fixed_Point_Type (Parent_Type)
8352 and then Nkind (Lo) = N_Real_Literal
8353 and then Nkind (Hi) = N_Real_Literal
8357 -- Here we do the analysis of the range.
8359 -- Note: we do this manually, since if we do a normal Analyze and
8360 -- Resolve call, there are problems with the conversions used for
8361 -- the derived type range.
8364 Set_Etype (Rng, Implicit_Base);
8365 Set_Analyzed (Rng, True);
8367 end Convert_Scalar_Bounds;
8373 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
8376 -- Initialize new full declaration entity by copying the pertinent
8377 -- fields of the corresponding private declaration entity.
8379 -- We temporarily set Ekind to a value appropriate for a type to
8380 -- avoid assert failures in Einfo from checking for setting type
8381 -- attributes on something that is not a type. Ekind (Priv) is an
8382 -- appropriate choice, since it allowed the attributes to be set
8383 -- in the first place. This Ekind value will be modified later.
8385 Set_Ekind (Full, Ekind (Priv));
8387 -- Also set Etype temporarily to Any_Type, again, in the absence
8388 -- of errors, it will be properly reset, and if there are errors,
8389 -- then we want a value of Any_Type to remain.
8391 Set_Etype (Full, Any_Type);
8393 -- Now start copying attributes
8395 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
8397 if Has_Discriminants (Full) then
8398 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
8399 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
8402 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
8403 Set_Homonym (Full, Homonym (Priv));
8404 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
8405 Set_Is_Public (Full, Is_Public (Priv));
8406 Set_Is_Pure (Full, Is_Pure (Priv));
8407 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
8409 Conditional_Delay (Full, Priv);
8411 if Is_Tagged_Type (Full) then
8412 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
8414 if Priv = Base_Type (Priv) then
8415 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
8419 Set_Is_Volatile (Full, Is_Volatile (Priv));
8420 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
8421 Set_Scope (Full, Scope (Priv));
8422 Set_Next_Entity (Full, Next_Entity (Priv));
8423 Set_First_Entity (Full, First_Entity (Priv));
8424 Set_Last_Entity (Full, Last_Entity (Priv));
8426 -- If access types have been recorded for later handling, keep them
8427 -- in the full view so that they get handled when the full view
8428 -- freeze node is expanded.
8430 if Present (Freeze_Node (Priv))
8431 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
8433 Ensure_Freeze_Node (Full);
8434 Set_Access_Types_To_Process
8435 (Freeze_Node (Full),
8436 Access_Types_To_Process (Freeze_Node (Priv)));
8439 -- Swap the two entities. Now Privat is the full type entity and
8440 -- Full is the private one. They will be swapped back at the end
8441 -- of the private part. This swapping ensures that the entity that
8442 -- is visible in the private part is the full declaration.
8444 Exchange_Entities (Priv, Full);
8445 Append_Entity (Full, Scope (Full));
8448 -------------------------------------
8449 -- Copy_Array_Base_Type_Attributes --
8450 -------------------------------------
8452 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
8454 Set_Component_Alignment (T1, Component_Alignment (T2));
8455 Set_Component_Type (T1, Component_Type (T2));
8456 Set_Component_Size (T1, Component_Size (T2));
8457 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
8458 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
8459 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
8460 Set_Has_Task (T1, Has_Task (T2));
8461 Set_Is_Packed (T1, Is_Packed (T2));
8462 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
8463 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
8464 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
8465 end Copy_Array_Base_Type_Attributes;
8467 -----------------------------------
8468 -- Copy_Array_Subtype_Attributes --
8469 -----------------------------------
8471 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
8473 Set_Size_Info (T1, T2);
8475 Set_First_Index (T1, First_Index (T2));
8476 Set_Is_Aliased (T1, Is_Aliased (T2));
8477 Set_Is_Atomic (T1, Is_Atomic (T2));
8478 Set_Is_Volatile (T1, Is_Volatile (T2));
8479 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
8480 Set_Is_Constrained (T1, Is_Constrained (T2));
8481 Set_Depends_On_Private (T1, Has_Private_Component (T2));
8482 Set_First_Rep_Item (T1, First_Rep_Item (T2));
8483 Set_Convention (T1, Convention (T2));
8484 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
8485 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
8486 end Copy_Array_Subtype_Attributes;
8488 -----------------------------------
8489 -- Create_Constrained_Components --
8490 -----------------------------------
8492 procedure Create_Constrained_Components
8494 Decl_Node : Node_Id;
8496 Constraints : Elist_Id)
8498 Loc : constant Source_Ptr := Sloc (Subt);
8499 Comp_List : constant Elist_Id := New_Elmt_List;
8500 Parent_Type : constant Entity_Id := Etype (Typ);
8501 Assoc_List : constant List_Id := New_List;
8502 Discr_Val : Elmt_Id;
8506 Is_Static : Boolean := True;
8508 procedure Collect_Fixed_Components (Typ : Entity_Id);
8509 -- Collect parent type components that do not appear in a variant part
8511 procedure Create_All_Components;
8512 -- Iterate over Comp_List to create the components of the subtype.
8514 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
8515 -- Creates a new component from Old_Compon, copying all the fields from
8516 -- it, including its Etype, inserts the new component in the Subt entity
8517 -- chain and returns the new component.
8519 function Is_Variant_Record (T : Entity_Id) return Boolean;
8520 -- If true, and discriminants are static, collect only components from
8521 -- variants selected by discriminant values.
8523 ------------------------------
8524 -- Collect_Fixed_Components --
8525 ------------------------------
8527 procedure Collect_Fixed_Components (Typ : Entity_Id) is
8529 -- Build association list for discriminants, and find components of
8530 -- the variant part selected by the values of the discriminants.
8532 Old_C := First_Discriminant (Typ);
8533 Discr_Val := First_Elmt (Constraints);
8535 while Present (Old_C) loop
8536 Append_To (Assoc_List,
8537 Make_Component_Association (Loc,
8538 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
8539 Expression => New_Copy (Node (Discr_Val))));
8541 Next_Elmt (Discr_Val);
8542 Next_Discriminant (Old_C);
8545 -- The tag, and the possible parent and controller components
8546 -- are unconditionally in the subtype.
8548 if Is_Tagged_Type (Typ)
8549 or else Has_Controlled_Component (Typ)
8551 Old_C := First_Component (Typ);
8553 while Present (Old_C) loop
8554 if Chars ((Old_C)) = Name_uTag
8555 or else Chars ((Old_C)) = Name_uParent
8556 or else Chars ((Old_C)) = Name_uController
8558 Append_Elmt (Old_C, Comp_List);
8561 Next_Component (Old_C);
8564 end Collect_Fixed_Components;
8566 ---------------------------
8567 -- Create_All_Components --
8568 ---------------------------
8570 procedure Create_All_Components is
8574 Comp := First_Elmt (Comp_List);
8576 while Present (Comp) loop
8577 Old_C := Node (Comp);
8578 New_C := Create_Component (Old_C);
8582 Constrain_Component_Type
8583 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
8584 Set_Is_Public (New_C, Is_Public (Subt));
8588 end Create_All_Components;
8590 ----------------------
8591 -- Create_Component --
8592 ----------------------
8594 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
8595 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
8598 -- Set the parent so we have a proper link for freezing etc. This
8599 -- is not a real parent pointer, since of course our parent does
8600 -- not own up to us and reference us, we are an illegitimate
8601 -- child of the original parent!
8603 Set_Parent (New_Compon, Parent (Old_Compon));
8605 -- We do not want this node marked as Comes_From_Source, since
8606 -- otherwise it would get first class status and a separate
8607 -- cross-reference line would be generated. Illegitimate
8608 -- children do not rate such recognition.
8610 Set_Comes_From_Source (New_Compon, False);
8612 -- But it is a real entity, and a birth certificate must be
8613 -- properly registered by entering it into the entity list.
8615 Enter_Name (New_Compon);
8617 end Create_Component;
8619 -----------------------
8620 -- Is_Variant_Record --
8621 -----------------------
8623 function Is_Variant_Record (T : Entity_Id) return Boolean is
8625 return Nkind (Parent (T)) = N_Full_Type_Declaration
8626 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
8627 and then Present (Component_List (Type_Definition (Parent (T))))
8629 Variant_Part (Component_List (Type_Definition (Parent (T)))));
8630 end Is_Variant_Record;
8632 -- Start of processing for Create_Constrained_Components
8635 pragma Assert (Subt /= Base_Type (Subt));
8636 pragma Assert (Typ = Base_Type (Typ));
8638 Set_First_Entity (Subt, Empty);
8639 Set_Last_Entity (Subt, Empty);
8641 -- Check whether constraint is fully static, in which case we can
8642 -- optimize the list of components.
8644 Discr_Val := First_Elmt (Constraints);
8646 while Present (Discr_Val) loop
8648 if not Is_OK_Static_Expression (Node (Discr_Val)) then
8653 Next_Elmt (Discr_Val);
8658 -- Inherit the discriminants of the parent type.
8660 Old_C := First_Discriminant (Typ);
8662 while Present (Old_C) loop
8663 New_C := Create_Component (Old_C);
8664 Set_Is_Public (New_C, Is_Public (Subt));
8665 Next_Discriminant (Old_C);
8669 and then Is_Variant_Record (Typ)
8671 Collect_Fixed_Components (Typ);
8675 Component_List (Type_Definition (Parent (Typ))),
8676 Governed_By => Assoc_List,
8678 Report_Errors => Errors);
8679 pragma Assert (not Errors);
8681 Create_All_Components;
8683 -- If the subtype declaration is created for a tagged type derivation
8684 -- with constraints, we retrieve the record definition of the parent
8685 -- type to select the components of the proper variant.
8688 and then Is_Tagged_Type (Typ)
8689 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
8691 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
8692 and then Is_Variant_Record (Parent_Type)
8694 Collect_Fixed_Components (Typ);
8698 Component_List (Type_Definition (Parent (Parent_Type))),
8699 Governed_By => Assoc_List,
8701 Report_Errors => Errors);
8702 pragma Assert (not Errors);
8704 -- If the tagged derivation has a type extension, collect all the
8705 -- new components therein.
8708 (Record_Extension_Part (Type_Definition (Parent (Typ))))
8710 Old_C := First_Component (Typ);
8712 while Present (Old_C) loop
8713 if Original_Record_Component (Old_C) = Old_C
8714 and then Chars (Old_C) /= Name_uTag
8715 and then Chars (Old_C) /= Name_uParent
8716 and then Chars (Old_C) /= Name_uController
8718 Append_Elmt (Old_C, Comp_List);
8721 Next_Component (Old_C);
8725 Create_All_Components;
8728 -- If the discriminants are not static, or if this is a multi-level
8729 -- type extension, we have to include all the components of the
8732 Old_C := First_Component (Typ);
8734 while Present (Old_C) loop
8735 New_C := Create_Component (Old_C);
8739 Constrain_Component_Type
8740 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
8741 Set_Is_Public (New_C, Is_Public (Subt));
8743 Next_Component (Old_C);
8748 end Create_Constrained_Components;
8750 ------------------------------------------
8751 -- Decimal_Fixed_Point_Type_Declaration --
8752 ------------------------------------------
8754 procedure Decimal_Fixed_Point_Type_Declaration
8758 Loc : constant Source_Ptr := Sloc (Def);
8759 Digs_Expr : constant Node_Id := Digits_Expression (Def);
8760 Delta_Expr : constant Node_Id := Delta_Expression (Def);
8761 Implicit_Base : Entity_Id;
8767 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
8770 Check_Restriction (No_Fixed_Point, Def);
8772 -- Create implicit base type
8775 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
8776 Set_Etype (Implicit_Base, Implicit_Base);
8778 -- Analyze and process delta expression
8780 Analyze_And_Resolve (Delta_Expr, Universal_Real);
8782 Check_Delta_Expression (Delta_Expr);
8783 Delta_Val := Expr_Value_R (Delta_Expr);
8785 -- Check delta is power of 10, and determine scale value from it
8788 Val : Ureal := Delta_Val;
8791 Scale_Val := Uint_0;
8793 if Val < Ureal_1 then
8794 while Val < Ureal_1 loop
8795 Val := Val * Ureal_10;
8796 Scale_Val := Scale_Val + 1;
8799 if Scale_Val > 18 then
8800 Error_Msg_N ("scale exceeds maximum value of 18", Def);
8801 Scale_Val := UI_From_Int (+18);
8805 while Val > Ureal_1 loop
8806 Val := Val / Ureal_10;
8807 Scale_Val := Scale_Val - 1;
8810 if Scale_Val < -18 then
8811 Error_Msg_N ("scale is less than minimum value of -18", Def);
8812 Scale_Val := UI_From_Int (-18);
8816 if Val /= Ureal_1 then
8817 Error_Msg_N ("delta expression must be a power of 10", Def);
8818 Delta_Val := Ureal_10 ** (-Scale_Val);
8822 -- Set delta, scale and small (small = delta for decimal type)
8824 Set_Delta_Value (Implicit_Base, Delta_Val);
8825 Set_Scale_Value (Implicit_Base, Scale_Val);
8826 Set_Small_Value (Implicit_Base, Delta_Val);
8828 -- Analyze and process digits expression
8830 Analyze_And_Resolve (Digs_Expr, Any_Integer);
8831 Check_Digits_Expression (Digs_Expr);
8832 Digs_Val := Expr_Value (Digs_Expr);
8834 if Digs_Val > 18 then
8835 Digs_Val := UI_From_Int (+18);
8836 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8839 Set_Digits_Value (Implicit_Base, Digs_Val);
8840 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8842 -- Set range of base type from digits value for now. This will be
8843 -- expanded to represent the true underlying base range by Freeze.
8845 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8847 -- Set size to zero for now, size will be set at freeze time. We have
8848 -- to do this for ordinary fixed-point, because the size depends on
8849 -- the specified small, and we might as well do the same for decimal
8852 Init_Size_Align (Implicit_Base);
8854 -- If there are bounds given in the declaration use them as the
8855 -- bounds of the first named subtype.
8857 if Present (Real_Range_Specification (Def)) then
8859 RRS : constant Node_Id := Real_Range_Specification (Def);
8860 Low : constant Node_Id := Low_Bound (RRS);
8861 High : constant Node_Id := High_Bound (RRS);
8866 Analyze_And_Resolve (Low, Any_Real);
8867 Analyze_And_Resolve (High, Any_Real);
8868 Check_Real_Bound (Low);
8869 Check_Real_Bound (High);
8870 Low_Val := Expr_Value_R (Low);
8871 High_Val := Expr_Value_R (High);
8873 if Low_Val < (-Bound_Val) then
8875 ("range low bound too small for digits value", Low);
8876 Low_Val := -Bound_Val;
8879 if High_Val > Bound_Val then
8881 ("range high bound too large for digits value", High);
8882 High_Val := Bound_Val;
8885 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
8888 -- If no explicit range, use range that corresponds to given
8889 -- digits value. This will end up as the final range for the
8893 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
8896 -- Complete entity for first subtype
8898 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
8899 Set_Etype (T, Implicit_Base);
8900 Set_Size_Info (T, Implicit_Base);
8901 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
8902 Set_Digits_Value (T, Digs_Val);
8903 Set_Delta_Value (T, Delta_Val);
8904 Set_Small_Value (T, Delta_Val);
8905 Set_Scale_Value (T, Scale_Val);
8906 Set_Is_Constrained (T);
8907 end Decimal_Fixed_Point_Type_Declaration;
8909 -----------------------
8910 -- Derive_Subprogram --
8911 -----------------------
8913 procedure Derive_Subprogram
8914 (New_Subp : in out Entity_Id;
8915 Parent_Subp : Entity_Id;
8916 Derived_Type : Entity_Id;
8917 Parent_Type : Entity_Id;
8918 Actual_Subp : Entity_Id := Empty)
8921 New_Formal : Entity_Id;
8922 Visible_Subp : Entity_Id := Parent_Subp;
8924 function Is_Private_Overriding return Boolean;
8925 -- If Subp is a private overriding of a visible operation, the in-
8926 -- herited operation derives from the overridden op (even though
8927 -- its body is the overriding one) and the inherited operation is
8928 -- visible now. See sem_disp to see the details of the handling of
8929 -- the overridden subprogram, which is removed from the list of
8930 -- primitive operations of the type. The overridden subprogram is
8931 -- saved locally in Visible_Subp, and used to diagnose abstract
8932 -- operations that need overriding in the derived type.
8934 procedure Replace_Type (Id, New_Id : Entity_Id);
8935 -- When the type is an anonymous access type, create a new access type
8936 -- designating the derived type.
8938 procedure Set_Derived_Name;
8939 -- This procedure sets the appropriate Chars name for New_Subp. This
8940 -- is normally just a copy of the parent name. An exception arises for
8941 -- type support subprograms, where the name is changed to reflect the
8942 -- name of the derived type, e.g. if type foo is derived from type bar,
8943 -- then a procedure barDA is derived with a name fooDA.
8945 ---------------------------
8946 -- Is_Private_Overriding --
8947 ---------------------------
8949 function Is_Private_Overriding return Boolean is
8953 Prev := Homonym (Parent_Subp);
8955 -- The visible operation that is overriden is a homonym of
8956 -- the parent subprogram. We scan the homonym chain to find
8957 -- the one whose alias is the subprogram we are deriving.
8959 while Present (Prev) loop
8960 if Is_Dispatching_Operation (Parent_Subp)
8961 and then Present (Prev)
8962 and then Ekind (Prev) = Ekind (Parent_Subp)
8963 and then Alias (Prev) = Parent_Subp
8964 and then Scope (Parent_Subp) = Scope (Prev)
8965 and then not Is_Hidden (Prev)
8967 Visible_Subp := Prev;
8971 Prev := Homonym (Prev);
8975 end Is_Private_Overriding;
8981 procedure Replace_Type (Id, New_Id : Entity_Id) is
8982 Acc_Type : Entity_Id;
8984 Par : constant Node_Id := Parent (Derived_Type);
8987 -- When the type is an anonymous access type, create a new access
8988 -- type designating the derived type. This itype must be elaborated
8989 -- at the point of the derivation, not on subsequent calls that may
8990 -- be out of the proper scope for Gigi, so we insert a reference to
8991 -- it after the derivation.
8993 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
8995 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
8998 if Ekind (Desig_Typ) = E_Record_Type_With_Private
8999 and then Present (Full_View (Desig_Typ))
9000 and then not Is_Private_Type (Parent_Type)
9002 Desig_Typ := Full_View (Desig_Typ);
9005 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
9006 Acc_Type := New_Copy (Etype (Id));
9007 Set_Etype (Acc_Type, Acc_Type);
9008 Set_Scope (Acc_Type, New_Subp);
9010 -- Compute size of anonymous access type.
9012 if Is_Array_Type (Desig_Typ)
9013 and then not Is_Constrained (Desig_Typ)
9015 Init_Size (Acc_Type, 2 * System_Address_Size);
9017 Init_Size (Acc_Type, System_Address_Size);
9020 Init_Alignment (Acc_Type);
9022 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
9024 Set_Etype (New_Id, Acc_Type);
9025 Set_Scope (New_Id, New_Subp);
9027 -- Create a reference to it
9029 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
9030 Set_Itype (IR, Acc_Type);
9031 Insert_After (Parent (Derived_Type), IR);
9034 Set_Etype (New_Id, Etype (Id));
9038 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
9040 (Ekind (Etype (Id)) = E_Record_Type_With_Private
9041 and then Present (Full_View (Etype (Id)))
9043 Base_Type (Full_View (Etype (Id))) = Base_Type (Parent_Type))
9045 -- Constraint checks on formals are generated during expansion,
9046 -- based on the signature of the original subprogram. The bounds
9047 -- of the derived type are not relevant, and thus we can use
9048 -- the base type for the formals. However, the return type may be
9049 -- used in a context that requires that the proper static bounds
9050 -- be used (a case statement, for example) and for those cases
9051 -- we must use the derived type (first subtype), not its base.
9053 -- If the derived_type_definition has no constraints, we know that
9054 -- the derived type has the same constraints as the first subtype
9055 -- of the parent, and we can also use it rather than its base,
9056 -- which can lead to more efficient code.
9058 if Etype (Id) = Parent_Type then
9059 if Is_Scalar_Type (Parent_Type)
9061 Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
9063 Set_Etype (New_Id, Derived_Type);
9065 elsif Nkind (Par) = N_Full_Type_Declaration
9067 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
9070 (Subtype_Indication (Type_Definition (Par)))
9072 Set_Etype (New_Id, Derived_Type);
9075 Set_Etype (New_Id, Base_Type (Derived_Type));
9079 Set_Etype (New_Id, Base_Type (Derived_Type));
9083 Set_Etype (New_Id, Etype (Id));
9087 ----------------------
9088 -- Set_Derived_Name --
9089 ----------------------
9091 procedure Set_Derived_Name is
9092 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
9094 if Nm = TSS_Null then
9095 Set_Chars (New_Subp, Chars (Parent_Subp));
9097 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
9099 end Set_Derived_Name;
9101 -- Start of processing for Derive_Subprogram
9105 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
9106 Set_Ekind (New_Subp, Ekind (Parent_Subp));
9108 -- Check whether the inherited subprogram is a private operation that
9109 -- should be inherited but not yet made visible. Such subprograms can
9110 -- become visible at a later point (e.g., the private part of a public
9111 -- child unit) via Declare_Inherited_Private_Subprograms. If the
9112 -- following predicate is true, then this is not such a private
9113 -- operation and the subprogram simply inherits the name of the parent
9114 -- subprogram. Note the special check for the names of controlled
9115 -- operations, which are currently exempted from being inherited with
9116 -- a hidden name because they must be findable for generation of
9117 -- implicit run-time calls.
9119 if not Is_Hidden (Parent_Subp)
9120 or else Is_Internal (Parent_Subp)
9121 or else Is_Private_Overriding
9122 or else Is_Internal_Name (Chars (Parent_Subp))
9123 or else Chars (Parent_Subp) = Name_Initialize
9124 or else Chars (Parent_Subp) = Name_Adjust
9125 or else Chars (Parent_Subp) = Name_Finalize
9129 -- If parent is hidden, this can be a regular derivation if the
9130 -- parent is immediately visible in a non-instantiating context,
9131 -- or if we are in the private part of an instance. This test
9132 -- should still be refined ???
9134 -- The test for In_Instance_Not_Visible avoids inheriting the
9135 -- derived operation as a non-visible operation in cases where
9136 -- the parent subprogram might not be visible now, but was
9137 -- visible within the original generic, so it would be wrong
9138 -- to make the inherited subprogram non-visible now. (Not
9139 -- clear if this test is fully correct; are there any cases
9140 -- where we should declare the inherited operation as not
9141 -- visible to avoid it being overridden, e.g., when the
9142 -- parent type is a generic actual with private primitives ???)
9144 -- (they should be treated the same as other private inherited
9145 -- subprograms, but it's not clear how to do this cleanly). ???
9147 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
9148 and then Is_Immediately_Visible (Parent_Subp)
9149 and then not In_Instance)
9150 or else In_Instance_Not_Visible
9154 -- The type is inheriting a private operation, so enter
9155 -- it with a special name so it can't be overridden.
9158 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
9161 Set_Parent (New_Subp, Parent (Derived_Type));
9162 Replace_Type (Parent_Subp, New_Subp);
9163 Conditional_Delay (New_Subp, Parent_Subp);
9165 Formal := First_Formal (Parent_Subp);
9166 while Present (Formal) loop
9167 New_Formal := New_Copy (Formal);
9169 -- Normally we do not go copying parents, but in the case of
9170 -- formals, we need to link up to the declaration (which is
9171 -- the parameter specification), and it is fine to link up to
9172 -- the original formal's parameter specification in this case.
9174 Set_Parent (New_Formal, Parent (Formal));
9176 Append_Entity (New_Formal, New_Subp);
9178 Replace_Type (Formal, New_Formal);
9179 Next_Formal (Formal);
9182 -- If this derivation corresponds to a tagged generic actual, then
9183 -- primitive operations rename those of the actual. Otherwise the
9184 -- primitive operations rename those of the parent type, If the
9185 -- parent renames an intrinsic operator, so does the new subprogram.
9186 -- We except concatenation, which is always properly typed, and does
9187 -- not get expanded as other intrinsic operations.
9189 if No (Actual_Subp) then
9190 if Is_Intrinsic_Subprogram (Parent_Subp) then
9191 Set_Is_Intrinsic_Subprogram (New_Subp);
9193 if Present (Alias (Parent_Subp))
9194 and then Chars (Parent_Subp) /= Name_Op_Concat
9196 Set_Alias (New_Subp, Alias (Parent_Subp));
9198 Set_Alias (New_Subp, Parent_Subp);
9202 Set_Alias (New_Subp, Parent_Subp);
9206 Set_Alias (New_Subp, Actual_Subp);
9209 -- Derived subprograms of a tagged type must inherit the convention
9210 -- of the parent subprogram (a requirement of AI-117). Derived
9211 -- subprograms of untagged types simply get convention Ada by default.
9213 if Is_Tagged_Type (Derived_Type) then
9214 Set_Convention (New_Subp, Convention (Parent_Subp));
9217 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
9218 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
9220 if Ekind (Parent_Subp) = E_Procedure then
9221 Set_Is_Valued_Procedure
9222 (New_Subp, Is_Valued_Procedure (Parent_Subp));
9225 -- A derived function with a controlling result is abstract.
9226 -- If the Derived_Type is a nonabstract formal generic derived
9227 -- type, then inherited operations are not abstract: check is
9228 -- done at instantiation time. If the derivation is for a generic
9229 -- actual, the function is not abstract unless the actual is.
9231 if Is_Generic_Type (Derived_Type)
9232 and then not Is_Abstract (Derived_Type)
9236 elsif Is_Abstract (Alias (New_Subp))
9237 or else (Is_Tagged_Type (Derived_Type)
9238 and then Etype (New_Subp) = Derived_Type
9239 and then No (Actual_Subp))
9241 Set_Is_Abstract (New_Subp);
9243 -- Finally, if the parent type is abstract we must verify that all
9244 -- inherited operations are either non-abstract or overridden, or
9245 -- that the derived type itself is abstract (this check is performed
9246 -- at the end of a package declaration, in Check_Abstract_Overriding).
9247 -- A private overriding in the parent type will not be visible in the
9248 -- derivation if we are not in an inner package or in a child unit of
9249 -- the parent type, in which case the abstractness of the inherited
9250 -- operation is carried to the new subprogram.
9252 elsif Is_Abstract (Parent_Type)
9253 and then not In_Open_Scopes (Scope (Parent_Type))
9254 and then Is_Private_Overriding
9255 and then Is_Abstract (Visible_Subp)
9257 Set_Alias (New_Subp, Visible_Subp);
9258 Set_Is_Abstract (New_Subp);
9261 New_Overloaded_Entity (New_Subp, Derived_Type);
9263 -- Check for case of a derived subprogram for the instantiation
9264 -- of a formal derived tagged type, if so mark the subprogram as
9265 -- dispatching and inherit the dispatching attributes of the
9266 -- parent subprogram. The derived subprogram is effectively a
9267 -- renaming of the actual subprogram, so it needs to have the
9268 -- same attributes as the actual.
9270 if Present (Actual_Subp)
9271 and then Is_Dispatching_Operation (Parent_Subp)
9273 Set_Is_Dispatching_Operation (New_Subp);
9274 if Present (DTC_Entity (Parent_Subp)) then
9275 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
9276 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
9280 -- Indicate that a derived subprogram does not require a body
9281 -- and that it does not require processing of default expressions.
9283 Set_Has_Completion (New_Subp);
9284 Set_Default_Expressions_Processed (New_Subp);
9286 if Ekind (New_Subp) = E_Function then
9287 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
9289 end Derive_Subprogram;
9291 ------------------------
9292 -- Derive_Subprograms --
9293 ------------------------
9295 procedure Derive_Subprograms
9296 (Parent_Type : Entity_Id;
9297 Derived_Type : Entity_Id;
9298 Generic_Actual : Entity_Id := Empty)
9300 Op_List : constant Elist_Id :=
9301 Collect_Primitive_Operations (Parent_Type);
9302 Act_List : Elist_Id;
9306 New_Subp : Entity_Id := Empty;
9307 Parent_Base : Entity_Id;
9310 if Ekind (Parent_Type) = E_Record_Type_With_Private
9311 and then Has_Discriminants (Parent_Type)
9312 and then Present (Full_View (Parent_Type))
9314 Parent_Base := Full_View (Parent_Type);
9316 Parent_Base := Parent_Type;
9319 Elmt := First_Elmt (Op_List);
9321 if Present (Generic_Actual) then
9322 Act_List := Collect_Primitive_Operations (Generic_Actual);
9323 Act_Elmt := First_Elmt (Act_List);
9325 Act_Elmt := No_Elmt;
9328 -- Literals are derived earlier in the process of building the
9329 -- derived type, and are skipped here.
9331 while Present (Elmt) loop
9332 Subp := Node (Elmt);
9334 if Ekind (Subp) /= E_Enumeration_Literal then
9335 if No (Generic_Actual) then
9337 (New_Subp, Subp, Derived_Type, Parent_Base);
9340 Derive_Subprogram (New_Subp, Subp,
9341 Derived_Type, Parent_Base, Node (Act_Elmt));
9342 Next_Elmt (Act_Elmt);
9348 end Derive_Subprograms;
9350 --------------------------------
9351 -- Derived_Standard_Character --
9352 --------------------------------
9354 procedure Derived_Standard_Character
9356 Parent_Type : Entity_Id;
9357 Derived_Type : Entity_Id)
9359 Loc : constant Source_Ptr := Sloc (N);
9360 Def : constant Node_Id := Type_Definition (N);
9361 Indic : constant Node_Id := Subtype_Indication (Def);
9362 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
9363 Implicit_Base : constant Entity_Id :=
9365 (E_Enumeration_Type, N, Derived_Type, 'B');
9371 Discard_Node (Process_Subtype (Indic, N));
9373 Set_Etype (Implicit_Base, Parent_Base);
9374 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
9375 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
9377 Set_Is_Character_Type (Implicit_Base, True);
9378 Set_Has_Delayed_Freeze (Implicit_Base);
9380 -- The bounds of the implicit base are the bounds of the parent base.
9381 -- Note that their type is the parent base.
9383 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
9384 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
9386 Set_Scalar_Range (Implicit_Base,
9391 Conditional_Delay (Derived_Type, Parent_Type);
9393 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
9394 Set_Etype (Derived_Type, Implicit_Base);
9395 Set_Size_Info (Derived_Type, Parent_Type);
9397 if Unknown_RM_Size (Derived_Type) then
9398 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
9401 Set_Is_Character_Type (Derived_Type, True);
9403 if Nkind (Indic) /= N_Subtype_Indication then
9405 -- If no explicit constraint, the bounds are those
9406 -- of the parent type.
9408 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
9409 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
9410 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
9413 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
9415 -- Because the implicit base is used in the conversion of the bounds,
9416 -- we have to freeze it now. This is similar to what is done for
9417 -- numeric types, and it equally suspicious, but otherwise a non-
9418 -- static bound will have a reference to an unfrozen type, which is
9419 -- rejected by Gigi (???).
9421 Freeze_Before (N, Implicit_Base);
9422 end Derived_Standard_Character;
9424 ------------------------------
9425 -- Derived_Type_Declaration --
9426 ------------------------------
9428 procedure Derived_Type_Declaration
9431 Is_Completion : Boolean)
9433 Def : constant Node_Id := Type_Definition (N);
9434 Indic : constant Node_Id := Subtype_Indication (Def);
9435 Extension : constant Node_Id := Record_Extension_Part (Def);
9436 Parent_Type : Entity_Id;
9437 Parent_Scope : Entity_Id;
9441 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
9443 if Parent_Type = Any_Type
9444 or else Etype (Parent_Type) = Any_Type
9445 or else (Is_Class_Wide_Type (Parent_Type)
9446 and then Etype (Parent_Type) = T)
9448 -- If Parent_Type is undefined or illegal, make new type into
9449 -- a subtype of Any_Type, and set a few attributes to prevent
9450 -- cascaded errors. If this is a self-definition, emit error now.
9453 or else T = Etype (Parent_Type)
9455 Error_Msg_N ("type cannot be used in its own definition", Indic);
9458 Set_Ekind (T, Ekind (Parent_Type));
9459 Set_Etype (T, Any_Type);
9460 Set_Scalar_Range (T, Scalar_Range (Any_Type));
9462 if Is_Tagged_Type (T) then
9463 Set_Primitive_Operations (T, New_Elmt_List);
9468 elsif Is_Unchecked_Union (Parent_Type) then
9469 Error_Msg_N ("cannot derive from Unchecked_Union type", N);
9471 -- Ada 2005 (AI-231): Static check
9473 elsif Is_Access_Type (Parent_Type)
9474 and then Null_Exclusion_Present (Type_Definition (N))
9475 and then Can_Never_Be_Null (Parent_Type)
9477 Error_Msg_N ("(Ada 2005) null exclusion not allowed if parent is "
9478 & "already non-null", Type_Definition (N));
9481 -- Only composite types other than array types are allowed to have
9484 if Present (Discriminant_Specifications (N))
9485 and then (Is_Elementary_Type (Parent_Type)
9486 or else Is_Array_Type (Parent_Type))
9487 and then not Error_Posted (N)
9490 ("elementary or array type cannot have discriminants",
9491 Defining_Identifier (First (Discriminant_Specifications (N))));
9492 Set_Has_Discriminants (T, False);
9495 -- In Ada 83, a derived type defined in a package specification cannot
9496 -- be used for further derivation until the end of its visible part.
9497 -- Note that derivation in the private part of the package is allowed.
9499 if Ada_Version = Ada_83
9500 and then Is_Derived_Type (Parent_Type)
9501 and then In_Visible_Part (Scope (Parent_Type))
9503 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
9505 ("(Ada 83): premature use of type for derivation", Indic);
9509 -- Check for early use of incomplete or private type
9511 if Ekind (Parent_Type) = E_Void
9512 or else Ekind (Parent_Type) = E_Incomplete_Type
9514 Error_Msg_N ("premature derivation of incomplete type", Indic);
9517 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
9518 and then not Is_Generic_Type (Parent_Type)
9519 and then not Is_Generic_Type (Root_Type (Parent_Type))
9520 and then not Is_Generic_Actual_Type (Parent_Type))
9521 or else Has_Private_Component (Parent_Type)
9523 -- The ancestor type of a formal type can be incomplete, in which
9524 -- case only the operations of the partial view are available in
9525 -- the generic. Subsequent checks may be required when the full
9526 -- view is analyzed, to verify that derivation from a tagged type
9527 -- has an extension.
9529 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
9532 elsif No (Underlying_Type (Parent_Type))
9533 or else Has_Private_Component (Parent_Type)
9536 ("premature derivation of derived or private type", Indic);
9538 -- Flag the type itself as being in error, this prevents some
9539 -- nasty problems with people looking at the malformed type.
9541 Set_Error_Posted (T);
9543 -- Check that within the immediate scope of an untagged partial
9544 -- view it's illegal to derive from the partial view if the
9545 -- full view is tagged. (7.3(7))
9547 -- We verify that the Parent_Type is a partial view by checking
9548 -- that it is not a Full_Type_Declaration (i.e. a private type or
9549 -- private extension declaration), to distinguish a partial view
9550 -- from a derivation from a private type which also appears as
9553 elsif Present (Full_View (Parent_Type))
9554 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
9555 and then not Is_Tagged_Type (Parent_Type)
9556 and then Is_Tagged_Type (Full_View (Parent_Type))
9558 Parent_Scope := Scope (T);
9559 while Present (Parent_Scope)
9560 and then Parent_Scope /= Standard_Standard
9562 if Parent_Scope = Scope (Parent_Type) then
9564 ("premature derivation from type with tagged full view",
9568 Parent_Scope := Scope (Parent_Scope);
9573 -- Check that form of derivation is appropriate
9575 Taggd := Is_Tagged_Type (Parent_Type);
9577 -- Perhaps the parent type should be changed to the class-wide type's
9578 -- specific type in this case to prevent cascading errors ???
9580 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
9581 Error_Msg_N ("parent type must not be a class-wide type", Indic);
9585 if Present (Extension) and then not Taggd then
9587 ("type derived from untagged type cannot have extension", Indic);
9589 elsif No (Extension) and then Taggd then
9590 -- If this is within a private part (or body) of a generic
9591 -- instantiation then the derivation is allowed (the parent
9592 -- type can only appear tagged in this case if it's a generic
9593 -- actual type, since it would otherwise have been rejected
9594 -- in the analysis of the generic template).
9596 if not Is_Generic_Actual_Type (Parent_Type)
9597 or else In_Visible_Part (Scope (Parent_Type))
9600 ("type derived from tagged type must have extension", Indic);
9604 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
9605 end Derived_Type_Declaration;
9607 ----------------------------------
9608 -- Enumeration_Type_Declaration --
9609 ----------------------------------
9611 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9618 -- Create identifier node representing lower bound
9620 B_Node := New_Node (N_Identifier, Sloc (Def));
9621 L := First (Literals (Def));
9622 Set_Chars (B_Node, Chars (L));
9623 Set_Entity (B_Node, L);
9624 Set_Etype (B_Node, T);
9625 Set_Is_Static_Expression (B_Node, True);
9627 R_Node := New_Node (N_Range, Sloc (Def));
9628 Set_Low_Bound (R_Node, B_Node);
9630 Set_Ekind (T, E_Enumeration_Type);
9631 Set_First_Literal (T, L);
9633 Set_Is_Constrained (T);
9637 -- Loop through literals of enumeration type setting pos and rep values
9638 -- except that if the Ekind is already set, then it means that the
9639 -- literal was already constructed (case of a derived type declaration
9640 -- and we should not disturb the Pos and Rep values.
9642 while Present (L) loop
9643 if Ekind (L) /= E_Enumeration_Literal then
9644 Set_Ekind (L, E_Enumeration_Literal);
9645 Set_Enumeration_Pos (L, Ev);
9646 Set_Enumeration_Rep (L, Ev);
9647 Set_Is_Known_Valid (L, True);
9651 New_Overloaded_Entity (L);
9652 Generate_Definition (L);
9653 Set_Convention (L, Convention_Intrinsic);
9655 if Nkind (L) = N_Defining_Character_Literal then
9656 Set_Is_Character_Type (T, True);
9663 -- Now create a node representing upper bound
9665 B_Node := New_Node (N_Identifier, Sloc (Def));
9666 Set_Chars (B_Node, Chars (Last (Literals (Def))));
9667 Set_Entity (B_Node, Last (Literals (Def)));
9668 Set_Etype (B_Node, T);
9669 Set_Is_Static_Expression (B_Node, True);
9671 Set_High_Bound (R_Node, B_Node);
9672 Set_Scalar_Range (T, R_Node);
9673 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
9676 -- Set Discard_Names if configuration pragma set, or if there is
9677 -- a parameterless pragma in the current declarative region
9679 if Global_Discard_Names
9680 or else Discard_Names (Scope (T))
9682 Set_Discard_Names (T);
9685 -- Process end label if there is one
9687 if Present (Def) then
9688 Process_End_Label (Def, 'e', T);
9690 end Enumeration_Type_Declaration;
9692 ---------------------------------
9693 -- Expand_To_Stored_Constraint --
9694 ---------------------------------
9696 function Expand_To_Stored_Constraint
9698 Constraint : Elist_Id) return Elist_Id
9700 Explicitly_Discriminated_Type : Entity_Id;
9701 Expansion : Elist_Id;
9702 Discriminant : Entity_Id;
9704 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
9705 -- Find the nearest type that actually specifies discriminants.
9707 ---------------------------------
9708 -- Type_With_Explicit_Discrims --
9709 ---------------------------------
9711 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
9712 Typ : constant E := Base_Type (Id);
9715 if Ekind (Typ) in Incomplete_Or_Private_Kind then
9716 if Present (Full_View (Typ)) then
9717 return Type_With_Explicit_Discrims (Full_View (Typ));
9721 if Has_Discriminants (Typ) then
9726 if Etype (Typ) = Typ then
9728 elsif Has_Discriminants (Typ) then
9731 return Type_With_Explicit_Discrims (Etype (Typ));
9734 end Type_With_Explicit_Discrims;
9736 -- Start of processing for Expand_To_Stored_Constraint
9740 or else Is_Empty_Elmt_List (Constraint)
9745 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
9747 if No (Explicitly_Discriminated_Type) then
9751 Expansion := New_Elmt_List;
9754 First_Stored_Discriminant (Explicitly_Discriminated_Type);
9756 while Present (Discriminant) loop
9759 Get_Discriminant_Value (
9760 Discriminant, Explicitly_Discriminated_Type, Constraint),
9763 Next_Stored_Discriminant (Discriminant);
9767 end Expand_To_Stored_Constraint;
9769 --------------------
9770 -- Find_Type_Name --
9771 --------------------
9773 function Find_Type_Name (N : Node_Id) return Entity_Id is
9774 Id : constant Entity_Id := Defining_Identifier (N);
9780 -- Find incomplete declaration, if some was given.
9782 Prev := Current_Entity_In_Scope (Id);
9784 if Present (Prev) then
9786 -- Previous declaration exists. Error if not incomplete/private case
9787 -- except if previous declaration is implicit, etc. Enter_Name will
9788 -- emit error if appropriate.
9790 Prev_Par := Parent (Prev);
9792 if not Is_Incomplete_Or_Private_Type (Prev) then
9796 elsif Nkind (N) /= N_Full_Type_Declaration
9797 and then Nkind (N) /= N_Task_Type_Declaration
9798 and then Nkind (N) /= N_Protected_Type_Declaration
9800 -- Completion must be a full type declarations (RM 7.3(4))
9802 Error_Msg_Sloc := Sloc (Prev);
9803 Error_Msg_NE ("invalid completion of }", Id, Prev);
9805 -- Set scope of Id to avoid cascaded errors. Entity is never
9806 -- examined again, except when saving globals in generics.
9808 Set_Scope (Id, Current_Scope);
9811 -- Case of full declaration of incomplete type
9813 elsif Ekind (Prev) = E_Incomplete_Type then
9815 -- Indicate that the incomplete declaration has a matching
9816 -- full declaration. The defining occurrence of the incomplete
9817 -- declaration remains the visible one, and the procedure
9818 -- Get_Full_View dereferences it whenever the type is used.
9820 if Present (Full_View (Prev)) then
9821 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9824 Set_Full_View (Prev, Id);
9825 Append_Entity (Id, Current_Scope);
9826 Set_Is_Public (Id, Is_Public (Prev));
9827 Set_Is_Internal (Id);
9830 -- Case of full declaration of private type
9833 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9834 if Etype (Prev) /= Prev then
9836 -- Prev is a private subtype or a derived type, and needs
9839 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9842 elsif Ekind (Prev) = E_Private_Type
9844 (Nkind (N) = N_Task_Type_Declaration
9845 or else Nkind (N) = N_Protected_Type_Declaration)
9848 ("completion of nonlimited type cannot be limited", N);
9851 elsif Nkind (N) /= N_Full_Type_Declaration
9852 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9854 Error_Msg_N ("full view of private extension must be"
9855 & " an extension", N);
9857 elsif not (Abstract_Present (Parent (Prev)))
9858 and then Abstract_Present (Type_Definition (N))
9860 Error_Msg_N ("full view of non-abstract extension cannot"
9861 & " be abstract", N);
9864 if not In_Private_Part (Current_Scope) then
9866 ("declaration of full view must appear in private part", N);
9869 Copy_And_Swap (Prev, Id);
9870 Set_Has_Private_Declaration (Prev);
9871 Set_Has_Private_Declaration (Id);
9873 -- If no error, propagate freeze_node from private to full view.
9874 -- It may have been generated for an early operational item.
9876 if Present (Freeze_Node (Id))
9877 and then Serious_Errors_Detected = 0
9878 and then No (Full_View (Id))
9880 Set_Freeze_Node (Prev, Freeze_Node (Id));
9881 Set_Freeze_Node (Id, Empty);
9882 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
9885 Set_Full_View (Id, Prev);
9889 -- Verify that full declaration conforms to incomplete one
9891 if Is_Incomplete_Or_Private_Type (Prev)
9892 and then Present (Discriminant_Specifications (Prev_Par))
9894 if Present (Discriminant_Specifications (N)) then
9895 if Ekind (Prev) = E_Incomplete_Type then
9896 Check_Discriminant_Conformance (N, Prev, Prev);
9898 Check_Discriminant_Conformance (N, Prev, Id);
9903 ("missing discriminants in full type declaration", N);
9905 -- To avoid cascaded errors on subsequent use, share the
9906 -- discriminants of the partial view.
9908 Set_Discriminant_Specifications (N,
9909 Discriminant_Specifications (Prev_Par));
9913 -- A prior untagged private type can have an associated
9914 -- class-wide type due to use of the class attribute,
9915 -- and in this case also the full type is required to
9919 and then (Is_Tagged_Type (Prev)
9920 or else Present (Class_Wide_Type (Prev)))
9922 -- The full declaration is either a tagged record or an
9923 -- extension otherwise this is an error
9925 if Nkind (Type_Definition (N)) = N_Record_Definition then
9926 if not Tagged_Present (Type_Definition (N)) then
9928 ("full declaration of } must be tagged", Prev, Id);
9929 Set_Is_Tagged_Type (Id);
9930 Set_Primitive_Operations (Id, New_Elmt_List);
9933 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
9934 if No (Record_Extension_Part (Type_Definition (N))) then
9936 "full declaration of } must be a record extension",
9938 Set_Is_Tagged_Type (Id);
9939 Set_Primitive_Operations (Id, New_Elmt_List);
9944 ("full declaration of } must be a tagged type", Prev, Id);
9952 -- New type declaration
9959 -------------------------
9960 -- Find_Type_Of_Object --
9961 -------------------------
9963 function Find_Type_Of_Object
9965 Related_Nod : Node_Id) return Entity_Id
9967 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
9968 P : Node_Id := Parent (Obj_Def);
9973 -- If the parent is a component_definition node we climb to the
9974 -- component_declaration node
9976 if Nkind (P) = N_Component_Definition then
9980 -- Case of an anonymous array subtype
9982 if Def_Kind = N_Constrained_Array_Definition
9983 or else Def_Kind = N_Unconstrained_Array_Definition
9986 Array_Type_Declaration (T, Obj_Def);
9988 -- Create an explicit subtype whenever possible.
9990 elsif Nkind (P) /= N_Component_Declaration
9991 and then Def_Kind = N_Subtype_Indication
9993 -- Base name of subtype on object name, which will be unique in
9994 -- the current scope.
9996 -- If this is a duplicate declaration, return base type, to avoid
9997 -- generating duplicate anonymous types.
9999 if Error_Posted (P) then
10000 Analyze (Subtype_Mark (Obj_Def));
10001 return Entity (Subtype_Mark (Obj_Def));
10006 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
10008 T := Make_Defining_Identifier (Sloc (P), Nam);
10010 Insert_Action (Obj_Def,
10011 Make_Subtype_Declaration (Sloc (P),
10012 Defining_Identifier => T,
10013 Subtype_Indication => Relocate_Node (Obj_Def)));
10015 -- This subtype may need freezing, and this will not be done
10016 -- automatically if the object declaration is not in a
10017 -- declarative part. Since this is an object declaration, the
10018 -- type cannot always be frozen here. Deferred constants do not
10019 -- freeze their type (which often enough will be private).
10021 if Nkind (P) = N_Object_Declaration
10022 and then Constant_Present (P)
10023 and then No (Expression (P))
10028 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
10032 T := Process_Subtype (Obj_Def, Related_Nod);
10036 end Find_Type_Of_Object;
10038 --------------------------------
10039 -- Find_Type_Of_Subtype_Indic --
10040 --------------------------------
10042 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
10046 -- Case of subtype mark with a constraint
10048 if Nkind (S) = N_Subtype_Indication then
10049 Find_Type (Subtype_Mark (S));
10050 Typ := Entity (Subtype_Mark (S));
10053 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
10056 ("incorrect constraint for this kind of type", Constraint (S));
10057 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
10060 -- Otherwise we have a subtype mark without a constraint
10062 elsif Error_Posted (S) then
10063 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
10071 if Typ = Standard_Wide_Character
10072 or else Typ = Standard_Wide_String
10074 Check_Restriction (No_Wide_Characters, S);
10078 end Find_Type_Of_Subtype_Indic;
10080 -------------------------------------
10081 -- Floating_Point_Type_Declaration --
10082 -------------------------------------
10084 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10085 Digs : constant Node_Id := Digits_Expression (Def);
10087 Base_Typ : Entity_Id;
10088 Implicit_Base : Entity_Id;
10091 function Can_Derive_From (E : Entity_Id) return Boolean;
10092 -- Find if given digits value allows derivation from specified type
10094 ---------------------
10095 -- Can_Derive_From --
10096 ---------------------
10098 function Can_Derive_From (E : Entity_Id) return Boolean is
10099 Spec : constant Entity_Id := Real_Range_Specification (Def);
10102 if Digs_Val > Digits_Value (E) then
10106 if Present (Spec) then
10107 if Expr_Value_R (Type_Low_Bound (E)) >
10108 Expr_Value_R (Low_Bound (Spec))
10113 if Expr_Value_R (Type_High_Bound (E)) <
10114 Expr_Value_R (High_Bound (Spec))
10121 end Can_Derive_From;
10123 -- Start of processing for Floating_Point_Type_Declaration
10126 Check_Restriction (No_Floating_Point, Def);
10128 -- Create an implicit base type
10131 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
10133 -- Analyze and verify digits value
10135 Analyze_And_Resolve (Digs, Any_Integer);
10136 Check_Digits_Expression (Digs);
10137 Digs_Val := Expr_Value (Digs);
10139 -- Process possible range spec and find correct type to derive from
10141 Process_Real_Range_Specification (Def);
10143 if Can_Derive_From (Standard_Short_Float) then
10144 Base_Typ := Standard_Short_Float;
10145 elsif Can_Derive_From (Standard_Float) then
10146 Base_Typ := Standard_Float;
10147 elsif Can_Derive_From (Standard_Long_Float) then
10148 Base_Typ := Standard_Long_Float;
10149 elsif Can_Derive_From (Standard_Long_Long_Float) then
10150 Base_Typ := Standard_Long_Long_Float;
10152 -- If we can't derive from any existing type, use long_long_float
10153 -- and give appropriate message explaining the problem.
10156 Base_Typ := Standard_Long_Long_Float;
10158 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
10159 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
10160 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
10164 ("range too large for any predefined type",
10165 Real_Range_Specification (Def));
10169 -- If there are bounds given in the declaration use them as the bounds
10170 -- of the type, otherwise use the bounds of the predefined base type
10171 -- that was chosen based on the Digits value.
10173 if Present (Real_Range_Specification (Def)) then
10174 Set_Scalar_Range (T, Real_Range_Specification (Def));
10175 Set_Is_Constrained (T);
10177 -- The bounds of this range must be converted to machine numbers
10178 -- in accordance with RM 4.9(38).
10180 Bound := Type_Low_Bound (T);
10182 if Nkind (Bound) = N_Real_Literal then
10184 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
10185 Set_Is_Machine_Number (Bound);
10188 Bound := Type_High_Bound (T);
10190 if Nkind (Bound) = N_Real_Literal then
10192 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
10193 Set_Is_Machine_Number (Bound);
10197 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
10200 -- Complete definition of implicit base and declared first subtype
10202 Set_Etype (Implicit_Base, Base_Typ);
10204 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
10205 Set_Size_Info (Implicit_Base, (Base_Typ));
10206 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
10207 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
10208 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
10209 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
10211 Set_Ekind (T, E_Floating_Point_Subtype);
10212 Set_Etype (T, Implicit_Base);
10214 Set_Size_Info (T, (Implicit_Base));
10215 Set_RM_Size (T, RM_Size (Implicit_Base));
10216 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
10217 Set_Digits_Value (T, Digs_Val);
10219 end Floating_Point_Type_Declaration;
10221 ----------------------------
10222 -- Get_Discriminant_Value --
10223 ----------------------------
10225 -- This is the situation...
10227 -- There is a non-derived type
10229 -- type T0 (Dx, Dy, Dz...)
10231 -- There are zero or more levels of derivation, with each
10232 -- derivation either purely inheriting the discriminants, or
10233 -- defining its own.
10235 -- type Ti is new Ti-1
10237 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
10239 -- subtype Ti is ...
10241 -- The subtype issue is avoided by the use of
10242 -- Original_Record_Component, and the fact that derived subtypes
10243 -- also derive the constraints.
10245 -- This chain leads back from
10247 -- Typ_For_Constraint
10249 -- Typ_For_Constraint has discriminants, and the value for each
10250 -- discriminant is given by its corresponding Elmt of Constraints.
10252 -- Discriminant is some discriminant in this hierarchy.
10254 -- We need to return its value.
10256 -- We do this by recursively searching each level, and looking for
10257 -- Discriminant. Once we get to the bottom, we start backing up
10258 -- returning the value for it which may in turn be a discriminant
10259 -- further up, so on the backup we continue the substitution.
10261 function Get_Discriminant_Value
10262 (Discriminant : Entity_Id;
10263 Typ_For_Constraint : Entity_Id;
10264 Constraint : Elist_Id) return Node_Id
10266 function Search_Derivation_Levels
10268 Discrim_Values : Elist_Id;
10269 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
10270 -- This is the routine that performs the recursive search of levels
10271 -- as described above.
10273 ------------------------------
10274 -- Search_Derivation_Levels --
10275 ------------------------------
10277 function Search_Derivation_Levels
10279 Discrim_Values : Elist_Id;
10280 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
10284 Result : Node_Or_Entity_Id;
10285 Result_Entity : Node_Id;
10288 -- If inappropriate type, return Error, this happens only in
10289 -- cascaded error situations, and we want to avoid a blow up.
10291 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
10295 -- Look deeper if possible. Use Stored_Constraints only for
10296 -- untagged types. For tagged types use the given constraint.
10297 -- This asymmetry needs explanation???
10299 if not Stored_Discrim_Values
10300 and then Present (Stored_Constraint (Ti))
10301 and then not Is_Tagged_Type (Ti)
10304 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
10307 Td : constant Entity_Id := Etype (Ti);
10311 Result := Discriminant;
10314 if Present (Stored_Constraint (Ti)) then
10316 Search_Derivation_Levels
10317 (Td, Stored_Constraint (Ti), True);
10320 Search_Derivation_Levels
10321 (Td, Discrim_Values, Stored_Discrim_Values);
10327 -- Extra underlying places to search, if not found above. For
10328 -- concurrent types, the relevant discriminant appears in the
10329 -- corresponding record. For a type derived from a private type
10330 -- without discriminant, the full view inherits the discriminants
10331 -- of the full view of the parent.
10333 if Result = Discriminant then
10334 if Is_Concurrent_Type (Ti)
10335 and then Present (Corresponding_Record_Type (Ti))
10338 Search_Derivation_Levels (
10339 Corresponding_Record_Type (Ti),
10341 Stored_Discrim_Values);
10343 elsif Is_Private_Type (Ti)
10344 and then not Has_Discriminants (Ti)
10345 and then Present (Full_View (Ti))
10346 and then Etype (Full_View (Ti)) /= Ti
10349 Search_Derivation_Levels (
10352 Stored_Discrim_Values);
10356 -- If Result is not a (reference to a) discriminant,
10357 -- return it, otherwise set Result_Entity to the discriminant.
10359 if Nkind (Result) = N_Defining_Identifier then
10361 pragma Assert (Result = Discriminant);
10363 Result_Entity := Result;
10366 if not Denotes_Discriminant (Result) then
10370 Result_Entity := Entity (Result);
10373 -- See if this level of derivation actually has discriminants
10374 -- because tagged derivations can add them, hence the lower
10375 -- levels need not have any.
10377 if not Has_Discriminants (Ti) then
10381 -- Scan Ti's discriminants for Result_Entity,
10382 -- and return its corresponding value, if any.
10384 Result_Entity := Original_Record_Component (Result_Entity);
10386 Assoc := First_Elmt (Discrim_Values);
10388 if Stored_Discrim_Values then
10389 Disc := First_Stored_Discriminant (Ti);
10391 Disc := First_Discriminant (Ti);
10394 while Present (Disc) loop
10396 pragma Assert (Present (Assoc));
10398 if Original_Record_Component (Disc) = Result_Entity then
10399 return Node (Assoc);
10404 if Stored_Discrim_Values then
10405 Next_Stored_Discriminant (Disc);
10407 Next_Discriminant (Disc);
10411 -- Could not find it
10414 end Search_Derivation_Levels;
10416 Result : Node_Or_Entity_Id;
10418 -- Start of processing for Get_Discriminant_Value
10421 -- ??? this routine is a gigantic mess and will be deleted.
10422 -- for the time being just test for the trivial case before calling
10425 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
10427 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
10428 E : Elmt_Id := First_Elmt (Constraint);
10430 while Present (D) loop
10431 if Chars (D) = Chars (Discriminant) then
10435 Next_Discriminant (D);
10441 Result := Search_Derivation_Levels
10442 (Typ_For_Constraint, Constraint, False);
10444 -- ??? hack to disappear when this routine is gone
10446 if Nkind (Result) = N_Defining_Identifier then
10448 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
10449 E : Elmt_Id := First_Elmt (Constraint);
10452 while Present (D) loop
10453 if Corresponding_Discriminant (D) = Discriminant then
10457 Next_Discriminant (D);
10463 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
10465 end Get_Discriminant_Value;
10467 --------------------------
10468 -- Has_Range_Constraint --
10469 --------------------------
10471 function Has_Range_Constraint (N : Node_Id) return Boolean is
10472 C : constant Node_Id := Constraint (N);
10475 if Nkind (C) = N_Range_Constraint then
10478 elsif Nkind (C) = N_Digits_Constraint then
10480 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
10482 Present (Range_Constraint (C));
10484 elsif Nkind (C) = N_Delta_Constraint then
10485 return Present (Range_Constraint (C));
10490 end Has_Range_Constraint;
10492 ------------------------
10493 -- Inherit_Components --
10494 ------------------------
10496 function Inherit_Components
10498 Parent_Base : Entity_Id;
10499 Derived_Base : Entity_Id;
10500 Is_Tagged : Boolean;
10501 Inherit_Discr : Boolean;
10502 Discs : Elist_Id) return Elist_Id
10504 Assoc_List : constant Elist_Id := New_Elmt_List;
10506 procedure Inherit_Component
10507 (Old_C : Entity_Id;
10508 Plain_Discrim : Boolean := False;
10509 Stored_Discrim : Boolean := False);
10510 -- Inherits component Old_C from Parent_Base to the Derived_Base.
10511 -- If Plain_Discrim is True, Old_C is a discriminant.
10512 -- If Stored_Discrim is True, Old_C is a stored discriminant.
10513 -- If they are both false then Old_C is a regular component.
10515 -----------------------
10516 -- Inherit_Component --
10517 -----------------------
10519 procedure Inherit_Component
10520 (Old_C : Entity_Id;
10521 Plain_Discrim : Boolean := False;
10522 Stored_Discrim : Boolean := False)
10524 New_C : constant Entity_Id := New_Copy (Old_C);
10526 Discrim : Entity_Id;
10527 Corr_Discrim : Entity_Id;
10530 pragma Assert (not Is_Tagged or else not Stored_Discrim);
10532 Set_Parent (New_C, Parent (Old_C));
10534 -- Regular discriminants and components must be inserted
10535 -- in the scope of the Derived_Base. Do it here.
10537 if not Stored_Discrim then
10538 Enter_Name (New_C);
10541 -- For tagged types the Original_Record_Component must point to
10542 -- whatever this field was pointing to in the parent type. This has
10543 -- already been achieved by the call to New_Copy above.
10545 if not Is_Tagged then
10546 Set_Original_Record_Component (New_C, New_C);
10549 -- If we have inherited a component then see if its Etype contains
10550 -- references to Parent_Base discriminants. In this case, replace
10551 -- these references with the constraints given in Discs. We do not
10552 -- do this for the partial view of private types because this is
10553 -- not needed (only the components of the full view will be used
10554 -- for code generation) and cause problem. We also avoid this
10555 -- transformation in some error situations.
10557 if Ekind (New_C) = E_Component then
10558 if (Is_Private_Type (Derived_Base)
10559 and then not Is_Generic_Type (Derived_Base))
10560 or else (Is_Empty_Elmt_List (Discs)
10561 and then not Expander_Active)
10563 Set_Etype (New_C, Etype (Old_C));
10565 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
10566 Derived_Base, N, Parent_Base, Discs));
10570 -- In derived tagged types it is illegal to reference a non
10571 -- discriminant component in the parent type. To catch this, mark
10572 -- these components with an Ekind of E_Void. This will be reset in
10573 -- Record_Type_Definition after processing the record extension of
10574 -- the derived type.
10576 if Is_Tagged and then Ekind (New_C) = E_Component then
10577 Set_Ekind (New_C, E_Void);
10580 if Plain_Discrim then
10581 Set_Corresponding_Discriminant (New_C, Old_C);
10582 Build_Discriminal (New_C);
10584 -- If we are explicitly inheriting a stored discriminant it will be
10585 -- completely hidden.
10587 elsif Stored_Discrim then
10588 Set_Corresponding_Discriminant (New_C, Empty);
10589 Set_Discriminal (New_C, Empty);
10590 Set_Is_Completely_Hidden (New_C);
10592 -- Set the Original_Record_Component of each discriminant in the
10593 -- derived base to point to the corresponding stored that we just
10596 Discrim := First_Discriminant (Derived_Base);
10597 while Present (Discrim) loop
10598 Corr_Discrim := Corresponding_Discriminant (Discrim);
10600 -- Corr_Discrimm could be missing in an error situation.
10602 if Present (Corr_Discrim)
10603 and then Original_Record_Component (Corr_Discrim) = Old_C
10605 Set_Original_Record_Component (Discrim, New_C);
10608 Next_Discriminant (Discrim);
10611 Append_Entity (New_C, Derived_Base);
10614 if not Is_Tagged then
10615 Append_Elmt (Old_C, Assoc_List);
10616 Append_Elmt (New_C, Assoc_List);
10618 end Inherit_Component;
10620 -- Variables local to Inherit_Components.
10622 Loc : constant Source_Ptr := Sloc (N);
10624 Parent_Discrim : Entity_Id;
10625 Stored_Discrim : Entity_Id;
10628 Component : Entity_Id;
10630 -- Start of processing for Inherit_Components
10633 if not Is_Tagged then
10634 Append_Elmt (Parent_Base, Assoc_List);
10635 Append_Elmt (Derived_Base, Assoc_List);
10638 -- Inherit parent discriminants if needed.
10640 if Inherit_Discr then
10641 Parent_Discrim := First_Discriminant (Parent_Base);
10642 while Present (Parent_Discrim) loop
10643 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
10644 Next_Discriminant (Parent_Discrim);
10648 -- Create explicit stored discrims for untagged types when necessary.
10650 if not Has_Unknown_Discriminants (Derived_Base)
10651 and then Has_Discriminants (Parent_Base)
10652 and then not Is_Tagged
10655 or else First_Discriminant (Parent_Base) /=
10656 First_Stored_Discriminant (Parent_Base))
10658 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
10659 while Present (Stored_Discrim) loop
10660 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
10661 Next_Stored_Discriminant (Stored_Discrim);
10665 -- See if we can apply the second transformation for derived types, as
10666 -- explained in point 6. in the comments above Build_Derived_Record_Type
10667 -- This is achieved by appending Derived_Base discriminants into
10668 -- Discs, which has the side effect of returning a non empty Discs
10669 -- list to the caller of Inherit_Components, which is what we want.
10670 -- This must be done for private derived types if there are explicit
10671 -- stored discriminants, to ensure that we can retrieve the values of
10672 -- the constraints provided in the ancestors.
10675 and then Is_Empty_Elmt_List (Discs)
10676 and then Present (First_Discriminant (Derived_Base))
10678 (not Is_Private_Type (Derived_Base)
10679 or else Is_Completely_Hidden
10680 (First_Stored_Discriminant (Derived_Base))
10681 or else Is_Generic_Type (Derived_Base))
10683 D := First_Discriminant (Derived_Base);
10684 while Present (D) loop
10685 Append_Elmt (New_Reference_To (D, Loc), Discs);
10686 Next_Discriminant (D);
10690 -- Finally, inherit non-discriminant components unless they are not
10691 -- visible because defined or inherited from the full view of the
10692 -- parent. Don't inherit the _parent field of the parent type.
10694 Component := First_Entity (Parent_Base);
10695 while Present (Component) loop
10696 if Ekind (Component) /= E_Component
10697 or else Chars (Component) = Name_uParent
10701 -- If the derived type is within the parent type's declarative
10702 -- region, then the components can still be inherited even though
10703 -- they aren't visible at this point. This can occur for cases
10704 -- such as within public child units where the components must
10705 -- become visible upon entering the child unit's private part.
10707 elsif not Is_Visible_Component (Component)
10708 and then not In_Open_Scopes (Scope (Parent_Base))
10712 elsif Ekind (Derived_Base) = E_Private_Type
10713 or else Ekind (Derived_Base) = E_Limited_Private_Type
10718 Inherit_Component (Component);
10721 Next_Entity (Component);
10724 -- For tagged derived types, inherited discriminants cannot be used in
10725 -- component declarations of the record extension part. To achieve this
10726 -- we mark the inherited discriminants as not visible.
10728 if Is_Tagged and then Inherit_Discr then
10729 D := First_Discriminant (Derived_Base);
10730 while Present (D) loop
10731 Set_Is_Immediately_Visible (D, False);
10732 Next_Discriminant (D);
10737 end Inherit_Components;
10739 ------------------------------
10740 -- Is_Valid_Constraint_Kind --
10741 ------------------------------
10743 function Is_Valid_Constraint_Kind
10744 (T_Kind : Type_Kind;
10745 Constraint_Kind : Node_Kind) return Boolean
10750 when Enumeration_Kind |
10752 return Constraint_Kind = N_Range_Constraint;
10754 when Decimal_Fixed_Point_Kind =>
10756 Constraint_Kind = N_Digits_Constraint
10758 Constraint_Kind = N_Range_Constraint;
10760 when Ordinary_Fixed_Point_Kind =>
10762 Constraint_Kind = N_Delta_Constraint
10764 Constraint_Kind = N_Range_Constraint;
10768 Constraint_Kind = N_Digits_Constraint
10770 Constraint_Kind = N_Range_Constraint;
10777 E_Incomplete_Type |
10780 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
10783 return True; -- Error will be detected later.
10786 end Is_Valid_Constraint_Kind;
10788 --------------------------
10789 -- Is_Visible_Component --
10790 --------------------------
10792 function Is_Visible_Component (C : Entity_Id) return Boolean is
10793 Original_Comp : Entity_Id := Empty;
10794 Original_Scope : Entity_Id;
10795 Type_Scope : Entity_Id;
10797 function Is_Local_Type (Typ : Entity_Id) return Boolean;
10798 -- Check whether parent type of inherited component is declared
10799 -- locally, possibly within a nested package or instance. The
10800 -- current scope is the derived record itself.
10802 -------------------
10803 -- Is_Local_Type --
10804 -------------------
10806 function Is_Local_Type (Typ : Entity_Id) return Boolean is
10807 Scop : Entity_Id := Scope (Typ);
10810 while Present (Scop)
10811 and then Scop /= Standard_Standard
10813 if Scop = Scope (Current_Scope) then
10817 Scop := Scope (Scop);
10822 -- Start of processing for Is_Visible_Component
10825 if Ekind (C) = E_Component
10826 or else Ekind (C) = E_Discriminant
10828 Original_Comp := Original_Record_Component (C);
10831 if No (Original_Comp) then
10833 -- Premature usage, or previous error
10838 Original_Scope := Scope (Original_Comp);
10839 Type_Scope := Scope (Base_Type (Scope (C)));
10842 -- This test only concerns tagged types
10844 if not Is_Tagged_Type (Original_Scope) then
10847 -- If it is _Parent or _Tag, there is no visibility issue
10849 elsif not Comes_From_Source (Original_Comp) then
10852 -- If we are in the body of an instantiation, the component is
10853 -- visible even when the parent type (possibly defined in an
10854 -- enclosing unit or in a parent unit) might not.
10856 elsif In_Instance_Body then
10859 -- Discriminants are always visible.
10861 elsif Ekind (Original_Comp) = E_Discriminant
10862 and then not Has_Unknown_Discriminants (Original_Scope)
10866 -- If the component has been declared in an ancestor which is
10867 -- currently a private type, then it is not visible. The same
10868 -- applies if the component's containing type is not in an
10869 -- open scope and the original component's enclosing type
10870 -- is a visible full type of a private type (which can occur
10871 -- in cases where an attempt is being made to reference a
10872 -- component in a sibling package that is inherited from a
10873 -- visible component of a type in an ancestor package; the
10874 -- component in the sibling package should not be visible
10875 -- even though the component it inherited from is visible).
10876 -- This does not apply however in the case where the scope
10877 -- of the type is a private child unit, or when the parent
10878 -- comes from a local package in which the ancestor is
10879 -- currently visible. The latter suppression of visibility
10880 -- is needed for cases that are tested in B730006.
10882 elsif Is_Private_Type (Original_Scope)
10884 (not Is_Private_Descendant (Type_Scope)
10885 and then not In_Open_Scopes (Type_Scope)
10886 and then Has_Private_Declaration (Original_Scope))
10888 -- If the type derives from an entity in a formal package, there
10889 -- are no additional visible components.
10891 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
10892 N_Formal_Package_Declaration
10896 -- if we are not in the private part of the current package, there
10897 -- are no additional visible components.
10899 elsif Ekind (Scope (Current_Scope)) = E_Package
10900 and then not In_Private_Part (Scope (Current_Scope))
10905 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
10906 and then Is_Local_Type (Type_Scope);
10909 -- There is another weird way in which a component may be invisible
10910 -- when the private and the full view are not derived from the same
10911 -- ancestor. Here is an example :
10913 -- type A1 is tagged record F1 : integer; end record;
10914 -- type A2 is new A1 with record F2 : integer; end record;
10915 -- type T is new A1 with private;
10917 -- type T is new A2 with null record;
10919 -- In this case, the full view of T inherits F1 and F2 but the
10920 -- private view inherits only F1
10924 Ancestor : Entity_Id := Scope (C);
10928 if Ancestor = Original_Scope then
10930 elsif Ancestor = Etype (Ancestor) then
10934 Ancestor := Etype (Ancestor);
10940 end Is_Visible_Component;
10942 --------------------------
10943 -- Make_Class_Wide_Type --
10944 --------------------------
10946 procedure Make_Class_Wide_Type (T : Entity_Id) is
10947 CW_Type : Entity_Id;
10949 Next_E : Entity_Id;
10952 -- The class wide type can have been defined by the partial view in
10953 -- which case everything is already done
10955 if Present (Class_Wide_Type (T)) then
10960 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
10962 -- Inherit root type characteristics
10964 CW_Name := Chars (CW_Type);
10965 Next_E := Next_Entity (CW_Type);
10966 Copy_Node (T, CW_Type);
10967 Set_Comes_From_Source (CW_Type, False);
10968 Set_Chars (CW_Type, CW_Name);
10969 Set_Parent (CW_Type, Parent (T));
10970 Set_Next_Entity (CW_Type, Next_E);
10971 Set_Has_Delayed_Freeze (CW_Type);
10973 -- Customize the class-wide type: It has no prim. op., it cannot be
10974 -- abstract and its Etype points back to the specific root type.
10976 Set_Ekind (CW_Type, E_Class_Wide_Type);
10977 Set_Is_Tagged_Type (CW_Type, True);
10978 Set_Primitive_Operations (CW_Type, New_Elmt_List);
10979 Set_Is_Abstract (CW_Type, False);
10980 Set_Is_Constrained (CW_Type, False);
10981 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
10982 Init_Size_Align (CW_Type);
10984 if Ekind (T) = E_Class_Wide_Subtype then
10985 Set_Etype (CW_Type, Etype (Base_Type (T)));
10987 Set_Etype (CW_Type, T);
10990 -- If this is the class_wide type of a constrained subtype, it does
10991 -- not have discriminants.
10993 Set_Has_Discriminants (CW_Type,
10994 Has_Discriminants (T) and then not Is_Constrained (T));
10996 Set_Has_Unknown_Discriminants (CW_Type, True);
10997 Set_Class_Wide_Type (T, CW_Type);
10998 Set_Equivalent_Type (CW_Type, Empty);
11000 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
11002 Set_Class_Wide_Type (CW_Type, CW_Type);
11004 end Make_Class_Wide_Type;
11010 procedure Make_Index
11012 Related_Nod : Node_Id;
11013 Related_Id : Entity_Id := Empty;
11014 Suffix_Index : Nat := 1)
11018 Def_Id : Entity_Id := Empty;
11019 Found : Boolean := False;
11022 -- For a discrete range used in a constrained array definition and
11023 -- defined by a range, an implicit conversion to the predefined type
11024 -- INTEGER is assumed if each bound is either a numeric literal, a named
11025 -- number, or an attribute, and the type of both bounds (prior to the
11026 -- implicit conversion) is the type universal_integer. Otherwise, both
11027 -- bounds must be of the same discrete type, other than universal
11028 -- integer; this type must be determinable independently of the
11029 -- context, but using the fact that the type must be discrete and that
11030 -- both bounds must have the same type.
11032 -- Character literals also have a universal type in the absence of
11033 -- of additional context, and are resolved to Standard_Character.
11035 if Nkind (I) = N_Range then
11037 -- The index is given by a range constraint. The bounds are known
11038 -- to be of a consistent type.
11040 if not Is_Overloaded (I) then
11043 -- If the bounds are universal, choose the specific predefined
11046 if T = Universal_Integer then
11047 T := Standard_Integer;
11049 elsif T = Any_Character then
11051 if Ada_Version >= Ada_95 then
11053 ("ambiguous character literals (could be Wide_Character)",
11057 T := Standard_Character;
11064 Ind : Interp_Index;
11068 Get_First_Interp (I, Ind, It);
11070 while Present (It.Typ) loop
11071 if Is_Discrete_Type (It.Typ) then
11074 and then not Covers (It.Typ, T)
11075 and then not Covers (T, It.Typ)
11077 Error_Msg_N ("ambiguous bounds in discrete range", I);
11085 Get_Next_Interp (Ind, It);
11088 if T = Any_Type then
11089 Error_Msg_N ("discrete type required for range", I);
11090 Set_Etype (I, Any_Type);
11093 elsif T = Universal_Integer then
11094 T := Standard_Integer;
11099 if not Is_Discrete_Type (T) then
11100 Error_Msg_N ("discrete type required for range", I);
11101 Set_Etype (I, Any_Type);
11105 if Nkind (Low_Bound (I)) = N_Attribute_Reference
11106 and then Attribute_Name (Low_Bound (I)) = Name_First
11107 and then Is_Entity_Name (Prefix (Low_Bound (I)))
11108 and then Is_Type (Entity (Prefix (Low_Bound (I))))
11109 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I))))
11111 -- The type of the index will be the type of the prefix,
11112 -- as long as the upper bound is 'Last of the same type.
11114 Def_Id := Entity (Prefix (Low_Bound (I)));
11116 if Nkind (High_Bound (I)) /= N_Attribute_Reference
11117 or else Attribute_Name (High_Bound (I)) /= Name_Last
11118 or else not Is_Entity_Name (Prefix (High_Bound (I)))
11119 or else Entity (Prefix (High_Bound (I))) /= Def_Id
11126 Process_Range_Expr_In_Decl (R, T);
11128 elsif Nkind (I) = N_Subtype_Indication then
11130 -- The index is given by a subtype with a range constraint.
11132 T := Base_Type (Entity (Subtype_Mark (I)));
11134 if not Is_Discrete_Type (T) then
11135 Error_Msg_N ("discrete type required for range", I);
11136 Set_Etype (I, Any_Type);
11140 R := Range_Expression (Constraint (I));
11143 Process_Range_Expr_In_Decl (R, Entity (Subtype_Mark (I)));
11145 elsif Nkind (I) = N_Attribute_Reference then
11147 -- The parser guarantees that the attribute is a RANGE attribute
11149 -- If the node denotes the range of a type mark, that is also the
11150 -- resulting type, and we do no need to create an Itype for it.
11152 if Is_Entity_Name (Prefix (I))
11153 and then Comes_From_Source (I)
11154 and then Is_Type (Entity (Prefix (I)))
11155 and then Is_Discrete_Type (Entity (Prefix (I)))
11157 Def_Id := Entity (Prefix (I));
11160 Analyze_And_Resolve (I);
11164 -- If none of the above, must be a subtype. We convert this to a
11165 -- range attribute reference because in the case of declared first
11166 -- named subtypes, the types in the range reference can be different
11167 -- from the type of the entity. A range attribute normalizes the
11168 -- reference and obtains the correct types for the bounds.
11170 -- This transformation is in the nature of an expansion, is only
11171 -- done if expansion is active. In particular, it is not done on
11172 -- formal generic types, because we need to retain the name of the
11173 -- original index for instantiation purposes.
11176 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
11177 Error_Msg_N ("invalid subtype mark in discrete range ", I);
11178 Set_Etype (I, Any_Integer);
11181 -- The type mark may be that of an incomplete type. It is only
11182 -- now that we can get the full view, previous analysis does
11183 -- not look specifically for a type mark.
11185 Set_Entity (I, Get_Full_View (Entity (I)));
11186 Set_Etype (I, Entity (I));
11187 Def_Id := Entity (I);
11189 if not Is_Discrete_Type (Def_Id) then
11190 Error_Msg_N ("discrete type required for index", I);
11191 Set_Etype (I, Any_Type);
11196 if Expander_Active then
11198 Make_Attribute_Reference (Sloc (I),
11199 Attribute_Name => Name_Range,
11200 Prefix => Relocate_Node (I)));
11202 -- The original was a subtype mark that does not freeze. This
11203 -- means that the rewritten version must not freeze either.
11205 Set_Must_Not_Freeze (I);
11206 Set_Must_Not_Freeze (Prefix (I));
11208 -- Is order critical??? if so, document why, if not
11209 -- use Analyze_And_Resolve
11216 -- If expander is inactive, type is legal, nothing else to construct
11223 if not Is_Discrete_Type (T) then
11224 Error_Msg_N ("discrete type required for range", I);
11225 Set_Etype (I, Any_Type);
11228 elsif T = Any_Type then
11229 Set_Etype (I, Any_Type);
11233 -- We will now create the appropriate Itype to describe the
11234 -- range, but first a check. If we originally had a subtype,
11235 -- then we just label the range with this subtype. Not only
11236 -- is there no need to construct a new subtype, but it is wrong
11237 -- to do so for two reasons:
11239 -- 1. A legality concern, if we have a subtype, it must not
11240 -- freeze, and the Itype would cause freezing incorrectly
11242 -- 2. An efficiency concern, if we created an Itype, it would
11243 -- not be recognized as the same type for the purposes of
11244 -- eliminating checks in some circumstances.
11246 -- We signal this case by setting the subtype entity in Def_Id.
11248 if No (Def_Id) then
11251 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
11252 Set_Etype (Def_Id, Base_Type (T));
11254 if Is_Signed_Integer_Type (T) then
11255 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
11257 elsif Is_Modular_Integer_Type (T) then
11258 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
11261 Set_Ekind (Def_Id, E_Enumeration_Subtype);
11262 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
11263 Set_First_Literal (Def_Id, First_Literal (T));
11266 Set_Size_Info (Def_Id, (T));
11267 Set_RM_Size (Def_Id, RM_Size (T));
11268 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11270 Set_Scalar_Range (Def_Id, R);
11271 Conditional_Delay (Def_Id, T);
11273 -- In the subtype indication case, if the immediate parent of the
11274 -- new subtype is non-static, then the subtype we create is non-
11275 -- static, even if its bounds are static.
11277 if Nkind (I) = N_Subtype_Indication
11278 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
11280 Set_Is_Non_Static_Subtype (Def_Id);
11284 -- Final step is to label the index with this constructed type
11286 Set_Etype (I, Def_Id);
11289 ------------------------------
11290 -- Modular_Type_Declaration --
11291 ------------------------------
11293 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
11294 Mod_Expr : constant Node_Id := Expression (Def);
11297 procedure Set_Modular_Size (Bits : Int);
11298 -- Sets RM_Size to Bits, and Esize to normal word size above this
11300 ----------------------
11301 -- Set_Modular_Size --
11302 ----------------------
11304 procedure Set_Modular_Size (Bits : Int) is
11306 Set_RM_Size (T, UI_From_Int (Bits));
11311 elsif Bits <= 16 then
11312 Init_Esize (T, 16);
11314 elsif Bits <= 32 then
11315 Init_Esize (T, 32);
11318 Init_Esize (T, System_Max_Binary_Modulus_Power);
11320 end Set_Modular_Size;
11322 -- Start of processing for Modular_Type_Declaration
11325 Analyze_And_Resolve (Mod_Expr, Any_Integer);
11327 Set_Ekind (T, E_Modular_Integer_Type);
11328 Init_Alignment (T);
11329 Set_Is_Constrained (T);
11331 if not Is_OK_Static_Expression (Mod_Expr) then
11332 Flag_Non_Static_Expr
11333 ("non-static expression used for modular type bound!", Mod_Expr);
11334 M_Val := 2 ** System_Max_Binary_Modulus_Power;
11336 M_Val := Expr_Value (Mod_Expr);
11340 Error_Msg_N ("modulus value must be positive", Mod_Expr);
11341 M_Val := 2 ** System_Max_Binary_Modulus_Power;
11344 Set_Modulus (T, M_Val);
11346 -- Create bounds for the modular type based on the modulus given in
11347 -- the type declaration and then analyze and resolve those bounds.
11349 Set_Scalar_Range (T,
11350 Make_Range (Sloc (Mod_Expr),
11352 Make_Integer_Literal (Sloc (Mod_Expr), 0),
11354 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
11356 -- Properly analyze the literals for the range. We do this manually
11357 -- because we can't go calling Resolve, since we are resolving these
11358 -- bounds with the type, and this type is certainly not complete yet!
11360 Set_Etype (Low_Bound (Scalar_Range (T)), T);
11361 Set_Etype (High_Bound (Scalar_Range (T)), T);
11362 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
11363 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
11365 -- Loop through powers of two to find number of bits required
11367 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
11371 if M_Val = 2 ** Bits then
11372 Set_Modular_Size (Bits);
11377 elsif M_Val < 2 ** Bits then
11378 Set_Non_Binary_Modulus (T);
11380 if Bits > System_Max_Nonbinary_Modulus_Power then
11381 Error_Msg_Uint_1 :=
11382 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
11384 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
11385 Set_Modular_Size (System_Max_Binary_Modulus_Power);
11389 -- In the non-binary case, set size as per RM 13.3(55).
11391 Set_Modular_Size (Bits);
11398 -- If we fall through, then the size exceed System.Max_Binary_Modulus
11399 -- so we just signal an error and set the maximum size.
11401 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
11402 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
11404 Set_Modular_Size (System_Max_Binary_Modulus_Power);
11405 Init_Alignment (T);
11407 end Modular_Type_Declaration;
11409 --------------------------
11410 -- New_Concatenation_Op --
11411 --------------------------
11413 procedure New_Concatenation_Op (Typ : Entity_Id) is
11414 Loc : constant Source_Ptr := Sloc (Typ);
11417 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
11418 -- Create abbreviated declaration for the formal of a predefined
11419 -- Operator 'Op' of type 'Typ'
11421 --------------------
11422 -- Make_Op_Formal --
11423 --------------------
11425 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
11426 Formal : Entity_Id;
11429 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
11430 Set_Etype (Formal, Typ);
11431 Set_Mechanism (Formal, Default_Mechanism);
11433 end Make_Op_Formal;
11435 -- Start of processing for New_Concatenation_Op
11438 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
11440 Set_Ekind (Op, E_Operator);
11441 Set_Scope (Op, Current_Scope);
11442 Set_Etype (Op, Typ);
11443 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
11444 Set_Is_Immediately_Visible (Op);
11445 Set_Is_Intrinsic_Subprogram (Op);
11446 Set_Has_Completion (Op);
11447 Append_Entity (Op, Current_Scope);
11449 Set_Name_Entity_Id (Name_Op_Concat, Op);
11451 Append_Entity (Make_Op_Formal (Typ, Op), Op);
11452 Append_Entity (Make_Op_Formal (Typ, Op), Op);
11454 end New_Concatenation_Op;
11456 -------------------------------------------
11457 -- Ordinary_Fixed_Point_Type_Declaration --
11458 -------------------------------------------
11460 procedure Ordinary_Fixed_Point_Type_Declaration
11464 Loc : constant Source_Ptr := Sloc (Def);
11465 Delta_Expr : constant Node_Id := Delta_Expression (Def);
11466 RRS : constant Node_Id := Real_Range_Specification (Def);
11467 Implicit_Base : Entity_Id;
11474 Check_Restriction (No_Fixed_Point, Def);
11476 -- Create implicit base type
11479 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
11480 Set_Etype (Implicit_Base, Implicit_Base);
11482 -- Analyze and process delta expression
11484 Analyze_And_Resolve (Delta_Expr, Any_Real);
11486 Check_Delta_Expression (Delta_Expr);
11487 Delta_Val := Expr_Value_R (Delta_Expr);
11489 Set_Delta_Value (Implicit_Base, Delta_Val);
11491 -- Compute default small from given delta, which is the largest
11492 -- power of two that does not exceed the given delta value.
11495 Tmp : Ureal := Ureal_1;
11499 if Delta_Val < Ureal_1 then
11500 while Delta_Val < Tmp loop
11501 Tmp := Tmp / Ureal_2;
11502 Scale := Scale + 1;
11507 Tmp := Tmp * Ureal_2;
11508 exit when Tmp > Delta_Val;
11509 Scale := Scale - 1;
11513 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
11516 Set_Small_Value (Implicit_Base, Small_Val);
11518 -- If no range was given, set a dummy range
11520 if RRS <= Empty_Or_Error then
11521 Low_Val := -Small_Val;
11522 High_Val := Small_Val;
11524 -- Otherwise analyze and process given range
11528 Low : constant Node_Id := Low_Bound (RRS);
11529 High : constant Node_Id := High_Bound (RRS);
11532 Analyze_And_Resolve (Low, Any_Real);
11533 Analyze_And_Resolve (High, Any_Real);
11534 Check_Real_Bound (Low);
11535 Check_Real_Bound (High);
11537 -- Obtain and set the range
11539 Low_Val := Expr_Value_R (Low);
11540 High_Val := Expr_Value_R (High);
11542 if Low_Val > High_Val then
11543 Error_Msg_NE ("?fixed point type& has null range", Def, T);
11548 -- The range for both the implicit base and the declared first
11549 -- subtype cannot be set yet, so we use the special routine
11550 -- Set_Fixed_Range to set a temporary range in place. Note that
11551 -- the bounds of the base type will be widened to be symmetrical
11552 -- and to fill the available bits when the type is frozen.
11554 -- We could do this with all discrete types, and probably should, but
11555 -- we absolutely have to do it for fixed-point, since the end-points
11556 -- of the range and the size are determined by the small value, which
11557 -- could be reset before the freeze point.
11559 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
11560 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
11562 Init_Size_Align (Implicit_Base);
11564 -- Complete definition of first subtype
11566 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
11567 Set_Etype (T, Implicit_Base);
11568 Init_Size_Align (T);
11569 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
11570 Set_Small_Value (T, Small_Val);
11571 Set_Delta_Value (T, Delta_Val);
11572 Set_Is_Constrained (T);
11574 end Ordinary_Fixed_Point_Type_Declaration;
11576 ----------------------------------------
11577 -- Prepare_Private_Subtype_Completion --
11578 ----------------------------------------
11580 procedure Prepare_Private_Subtype_Completion
11582 Related_Nod : Node_Id)
11584 Id_B : constant Entity_Id := Base_Type (Id);
11585 Full_B : constant Entity_Id := Full_View (Id_B);
11589 if Present (Full_B) then
11591 -- The Base_Type is already completed, we can complete the
11592 -- subtype now. We have to create a new entity with the same name,
11593 -- Thus we can't use Create_Itype.
11594 -- This is messy, should be fixed ???
11596 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
11597 Set_Is_Itype (Full);
11598 Set_Associated_Node_For_Itype (Full, Related_Nod);
11599 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
11602 -- The parent subtype may be private, but the base might not, in some
11603 -- nested instances. In that case, the subtype does not need to be
11604 -- exchanged. It would still be nice to make private subtypes and their
11605 -- bases consistent at all times ???
11607 if Is_Private_Type (Id_B) then
11608 Append_Elmt (Id, Private_Dependents (Id_B));
11611 end Prepare_Private_Subtype_Completion;
11613 ---------------------------
11614 -- Process_Discriminants --
11615 ---------------------------
11617 procedure Process_Discriminants
11619 Prev : Entity_Id := Empty)
11621 Elist : constant Elist_Id := New_Elmt_List;
11624 Discr_Number : Uint;
11625 Discr_Type : Entity_Id;
11626 Default_Present : Boolean := False;
11627 Default_Not_Present : Boolean := False;
11630 -- A composite type other than an array type can have discriminants.
11631 -- Discriminants of non-limited types must have a discrete type.
11632 -- On entry, the current scope is the composite type.
11634 -- The discriminants are initially entered into the scope of the type
11635 -- via Enter_Name with the default Ekind of E_Void to prevent premature
11636 -- use, as explained at the end of this procedure.
11638 Discr := First (Discriminant_Specifications (N));
11639 while Present (Discr) loop
11640 Enter_Name (Defining_Identifier (Discr));
11642 -- For navigation purposes we add a reference to the discriminant
11643 -- in the entity for the type. If the current declaration is a
11644 -- completion, place references on the partial view. Otherwise the
11645 -- type is the current scope.
11647 if Present (Prev) then
11649 -- The references go on the partial view, if present. If the
11650 -- partial view has discriminants, the references have been
11651 -- generated already.
11653 if not Has_Discriminants (Prev) then
11654 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
11658 (Current_Scope, Defining_Identifier (Discr), 'd');
11661 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
11662 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
11664 -- Ada 2005 (AI-254)
11666 if Present (Access_To_Subprogram_Definition
11667 (Discriminant_Type (Discr)))
11668 and then Protected_Present (Access_To_Subprogram_Definition
11669 (Discriminant_Type (Discr)))
11672 Replace_Anonymous_Access_To_Protected_Subprogram
11673 (Discr, Discr_Type);
11677 Find_Type (Discriminant_Type (Discr));
11678 Discr_Type := Etype (Discriminant_Type (Discr));
11680 if Error_Posted (Discriminant_Type (Discr)) then
11681 Discr_Type := Any_Type;
11685 if Is_Access_Type (Discr_Type) then
11687 -- Ada 2005 (AI-230): Access discriminant allowed in non-limited
11690 if Ada_Version < Ada_05 then
11691 Check_Access_Discriminant_Requires_Limited
11692 (Discr, Discriminant_Type (Discr));
11695 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
11697 ("(Ada 83) access discriminant not allowed", Discr);
11700 elsif not Is_Discrete_Type (Discr_Type) then
11701 Error_Msg_N ("discriminants must have a discrete or access type",
11702 Discriminant_Type (Discr));
11705 Set_Etype (Defining_Identifier (Discr), Discr_Type);
11707 -- If a discriminant specification includes the assignment compound
11708 -- delimiter followed by an expression, the expression is the default
11709 -- expression of the discriminant; the default expression must be of
11710 -- the type of the discriminant. (RM 3.7.1) Since this expression is
11711 -- a default expression, we do the special preanalysis, since this
11712 -- expression does not freeze (see "Handling of Default and Per-
11713 -- Object Expressions" in spec of package Sem).
11715 if Present (Expression (Discr)) then
11716 Analyze_Per_Use_Expression (Expression (Discr), Discr_Type);
11718 if Nkind (N) = N_Formal_Type_Declaration then
11720 ("discriminant defaults not allowed for formal type",
11721 Expression (Discr));
11723 -- Tagged types cannot have defaulted discriminants, but a
11724 -- non-tagged private type with defaulted discriminants
11725 -- can have a tagged completion.
11727 elsif Is_Tagged_Type (Current_Scope)
11728 and then Comes_From_Source (N)
11731 ("discriminants of tagged type cannot have defaults",
11732 Expression (Discr));
11735 Default_Present := True;
11736 Append_Elmt (Expression (Discr), Elist);
11738 -- Tag the defining identifiers for the discriminants with
11739 -- their corresponding default expressions from the tree.
11741 Set_Discriminant_Default_Value
11742 (Defining_Identifier (Discr), Expression (Discr));
11746 Default_Not_Present := True;
11749 -- Ada 2005 (AI-231): Set the null-excluding attribute and carry
11750 -- out some static checks.
11752 if Ada_Version >= Ada_05
11753 and then (Null_Exclusion_Present (Discr)
11754 or else Can_Never_Be_Null (Discr_Type))
11756 Set_Can_Never_Be_Null (Defining_Identifier (Discr));
11757 Null_Exclusion_Static_Checks (Discr);
11763 -- An element list consisting of the default expressions of the
11764 -- discriminants is constructed in the above loop and used to set
11765 -- the Discriminant_Constraint attribute for the type. If an object
11766 -- is declared of this (record or task) type without any explicit
11767 -- discriminant constraint given, this element list will form the
11768 -- actual parameters for the corresponding initialization procedure
11771 Set_Discriminant_Constraint (Current_Scope, Elist);
11772 Set_Stored_Constraint (Current_Scope, No_Elist);
11774 -- Default expressions must be provided either for all or for none
11775 -- of the discriminants of a discriminant part. (RM 3.7.1)
11777 if Default_Present and then Default_Not_Present then
11779 ("incomplete specification of defaults for discriminants", N);
11782 -- The use of the name of a discriminant is not allowed in default
11783 -- expressions of a discriminant part if the specification of the
11784 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
11786 -- To detect this, the discriminant names are entered initially with an
11787 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
11788 -- attempt to use a void entity (for example in an expression that is
11789 -- type-checked) produces the error message: premature usage. Now after
11790 -- completing the semantic analysis of the discriminant part, we can set
11791 -- the Ekind of all the discriminants appropriately.
11793 Discr := First (Discriminant_Specifications (N));
11794 Discr_Number := Uint_1;
11796 while Present (Discr) loop
11797 Id := Defining_Identifier (Discr);
11798 Set_Ekind (Id, E_Discriminant);
11799 Init_Component_Location (Id);
11801 Set_Discriminant_Number (Id, Discr_Number);
11803 -- Make sure this is always set, even in illegal programs
11805 Set_Corresponding_Discriminant (Id, Empty);
11807 -- Initialize the Original_Record_Component to the entity itself.
11808 -- Inherit_Components will propagate the right value to
11809 -- discriminants in derived record types.
11811 Set_Original_Record_Component (Id, Id);
11813 -- Create the discriminal for the discriminant.
11815 Build_Discriminal (Id);
11818 Discr_Number := Discr_Number + 1;
11821 Set_Has_Discriminants (Current_Scope);
11822 end Process_Discriminants;
11824 -----------------------
11825 -- Process_Full_View --
11826 -----------------------
11828 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
11829 Priv_Parent : Entity_Id;
11830 Full_Parent : Entity_Id;
11831 Full_Indic : Node_Id;
11834 -- First some sanity checks that must be done after semantic
11835 -- decoration of the full view and thus cannot be placed with other
11836 -- similar checks in Find_Type_Name
11838 if not Is_Limited_Type (Priv_T)
11839 and then (Is_Limited_Type (Full_T)
11840 or else Is_Limited_Composite (Full_T))
11843 ("completion of nonlimited type cannot be limited", Full_T);
11844 Explain_Limited_Type (Full_T, Full_T);
11846 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
11848 ("completion of nonabstract type cannot be abstract", Full_T);
11850 elsif Is_Tagged_Type (Priv_T)
11851 and then Is_Limited_Type (Priv_T)
11852 and then not Is_Limited_Type (Full_T)
11854 -- GNAT allow its own definition of Limited_Controlled to disobey
11855 -- this rule in order in ease the implementation. The next test is
11856 -- safe because Root_Controlled is defined in a private system child
11858 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
11859 Set_Is_Limited_Composite (Full_T);
11862 ("completion of limited tagged type must be limited", Full_T);
11865 elsif Is_Generic_Type (Priv_T) then
11866 Error_Msg_N ("generic type cannot have a completion", Full_T);
11869 if Is_Tagged_Type (Priv_T)
11870 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
11871 and then Is_Derived_Type (Full_T)
11873 Priv_Parent := Etype (Priv_T);
11875 -- The full view of a private extension may have been transformed
11876 -- into an unconstrained derived type declaration and a subtype
11877 -- declaration (see build_derived_record_type for details).
11879 if Nkind (N) = N_Subtype_Declaration then
11880 Full_Indic := Subtype_Indication (N);
11881 Full_Parent := Etype (Base_Type (Full_T));
11883 Full_Indic := Subtype_Indication (Type_Definition (N));
11884 Full_Parent := Etype (Full_T);
11887 -- Check that the parent type of the full type is a descendant of
11888 -- the ancestor subtype given in the private extension. If either
11889 -- entity has an Etype equal to Any_Type then we had some previous
11890 -- error situation [7.3(8)].
11892 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
11895 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
11897 ("parent of full type must descend from parent"
11898 & " of private extension", Full_Indic);
11900 -- Check the rules of 7.3(10): if the private extension inherits
11901 -- known discriminants, then the full type must also inherit those
11902 -- discriminants from the same (ancestor) type, and the parent
11903 -- subtype of the full type must be constrained if and only if
11904 -- the ancestor subtype of the private extension is constrained.
11906 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
11907 and then not Has_Unknown_Discriminants (Priv_T)
11908 and then Has_Discriminants (Base_Type (Priv_Parent))
11911 Priv_Indic : constant Node_Id :=
11912 Subtype_Indication (Parent (Priv_T));
11914 Priv_Constr : constant Boolean :=
11915 Is_Constrained (Priv_Parent)
11917 Nkind (Priv_Indic) = N_Subtype_Indication
11918 or else Is_Constrained (Entity (Priv_Indic));
11920 Full_Constr : constant Boolean :=
11921 Is_Constrained (Full_Parent)
11923 Nkind (Full_Indic) = N_Subtype_Indication
11924 or else Is_Constrained (Entity (Full_Indic));
11926 Priv_Discr : Entity_Id;
11927 Full_Discr : Entity_Id;
11930 Priv_Discr := First_Discriminant (Priv_Parent);
11931 Full_Discr := First_Discriminant (Full_Parent);
11933 while Present (Priv_Discr) and then Present (Full_Discr) loop
11934 if Original_Record_Component (Priv_Discr) =
11935 Original_Record_Component (Full_Discr)
11937 Corresponding_Discriminant (Priv_Discr) =
11938 Corresponding_Discriminant (Full_Discr)
11945 Next_Discriminant (Priv_Discr);
11946 Next_Discriminant (Full_Discr);
11949 if Present (Priv_Discr) or else Present (Full_Discr) then
11951 ("full view must inherit discriminants of the parent type"
11952 & " used in the private extension", Full_Indic);
11954 elsif Priv_Constr and then not Full_Constr then
11956 ("parent subtype of full type must be constrained",
11959 elsif Full_Constr and then not Priv_Constr then
11961 ("parent subtype of full type must be unconstrained",
11966 -- Check the rules of 7.3(12): if a partial view has neither known
11967 -- or unknown discriminants, then the full type declaration shall
11968 -- define a definite subtype.
11970 elsif not Has_Unknown_Discriminants (Priv_T)
11971 and then not Has_Discriminants (Priv_T)
11972 and then not Is_Constrained (Full_T)
11975 ("full view must define a constrained type if partial view"
11976 & " has no discriminants", Full_T);
11979 -- ??????? Do we implement the following properly ?????
11980 -- If the ancestor subtype of a private extension has constrained
11981 -- discriminants, then the parent subtype of the full view shall
11982 -- impose a statically matching constraint on those discriminants
11986 -- For untagged types, verify that a type without discriminants
11987 -- is not completed with an unconstrained type.
11989 if not Is_Indefinite_Subtype (Priv_T)
11990 and then Is_Indefinite_Subtype (Full_T)
11992 Error_Msg_N ("full view of type must be definite subtype", Full_T);
11996 -- Create a full declaration for all its subtypes recorded in
11997 -- Private_Dependents and swap them similarly to the base type.
11998 -- These are subtypes that have been define before the full
11999 -- declaration of the private type. We also swap the entry in
12000 -- Private_Dependents list so we can properly restore the
12001 -- private view on exit from the scope.
12004 Priv_Elmt : Elmt_Id;
12009 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
12010 while Present (Priv_Elmt) loop
12011 Priv := Node (Priv_Elmt);
12013 if Ekind (Priv) = E_Private_Subtype
12014 or else Ekind (Priv) = E_Limited_Private_Subtype
12015 or else Ekind (Priv) = E_Record_Subtype_With_Private
12017 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
12018 Set_Is_Itype (Full);
12019 Set_Parent (Full, Parent (Priv));
12020 Set_Associated_Node_For_Itype (Full, N);
12022 -- Now we need to complete the private subtype, but since the
12023 -- base type has already been swapped, we must also swap the
12024 -- subtypes (and thus, reverse the arguments in the call to
12025 -- Complete_Private_Subtype).
12027 Copy_And_Swap (Priv, Full);
12028 Complete_Private_Subtype (Full, Priv, Full_T, N);
12029 Replace_Elmt (Priv_Elmt, Full);
12032 Next_Elmt (Priv_Elmt);
12036 -- If the private view was tagged, copy the new Primitive
12037 -- operations from the private view to the full view.
12039 if Is_Tagged_Type (Full_T) then
12041 Priv_List : Elist_Id;
12042 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
12045 D_Type : Entity_Id;
12048 if Is_Tagged_Type (Priv_T) then
12049 Priv_List := Primitive_Operations (Priv_T);
12051 P1 := First_Elmt (Priv_List);
12052 while Present (P1) loop
12055 -- Transfer explicit primitives, not those inherited from
12056 -- parent of partial view, which will be re-inherited on
12059 if Comes_From_Source (Prim) then
12060 P2 := First_Elmt (Full_List);
12061 while Present (P2) and then Node (P2) /= Prim loop
12065 -- If not found, that is a new one
12068 Append_Elmt (Prim, Full_List);
12076 -- In this case the partial view is untagged, so here we
12077 -- locate all of the earlier primitives that need to be
12078 -- treated as dispatching (those that appear between the
12079 -- two views). Note that these additional operations must
12080 -- all be new operations (any earlier operations that
12081 -- override inherited operations of the full view will
12082 -- already have been inserted in the primitives list and
12083 -- marked as dispatching by Check_Operation_From_Private_View.
12084 -- Note that implicit "/=" operators are excluded from being
12085 -- added to the primitives list since they shouldn't be
12086 -- treated as dispatching (tagged "/=" is handled specially).
12088 Prim := Next_Entity (Full_T);
12089 while Present (Prim) and then Prim /= Priv_T loop
12090 if Ekind (Prim) = E_Procedure
12092 Ekind (Prim) = E_Function
12095 D_Type := Find_Dispatching_Type (Prim);
12098 and then (Chars (Prim) /= Name_Op_Ne
12099 or else Comes_From_Source (Prim))
12101 Check_Controlling_Formals (Full_T, Prim);
12103 if not Is_Dispatching_Operation (Prim) then
12104 Append_Elmt (Prim, Full_List);
12105 Set_Is_Dispatching_Operation (Prim, True);
12106 Set_DT_Position (Prim, No_Uint);
12109 elsif Is_Dispatching_Operation (Prim)
12110 and then D_Type /= Full_T
12113 -- Verify that it is not otherwise controlled by
12114 -- a formal or a return value ot type T.
12116 Check_Controlling_Formals (D_Type, Prim);
12120 Next_Entity (Prim);
12124 -- For the tagged case, the two views can share the same
12125 -- Primitive Operation list and the same class wide type.
12126 -- Update attributes of the class-wide type which depend on
12127 -- the full declaration.
12129 if Is_Tagged_Type (Priv_T) then
12130 Set_Primitive_Operations (Priv_T, Full_List);
12131 Set_Class_Wide_Type
12132 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
12134 -- Any other attributes should be propagated to C_W ???
12136 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
12141 end Process_Full_View;
12143 -----------------------------------
12144 -- Process_Incomplete_Dependents --
12145 -----------------------------------
12147 procedure Process_Incomplete_Dependents
12149 Full_T : Entity_Id;
12152 Inc_Elmt : Elmt_Id;
12153 Priv_Dep : Entity_Id;
12154 New_Subt : Entity_Id;
12156 Disc_Constraint : Elist_Id;
12159 if No (Private_Dependents (Inc_T)) then
12163 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
12165 -- Itypes that may be generated by the completion of an incomplete
12166 -- subtype are not used by the back-end and not attached to the tree.
12167 -- They are created only for constraint-checking purposes.
12170 while Present (Inc_Elmt) loop
12171 Priv_Dep := Node (Inc_Elmt);
12173 if Ekind (Priv_Dep) = E_Subprogram_Type then
12175 -- An Access_To_Subprogram type may have a return type or a
12176 -- parameter type that is incomplete. Replace with the full view.
12178 if Etype (Priv_Dep) = Inc_T then
12179 Set_Etype (Priv_Dep, Full_T);
12183 Formal : Entity_Id;
12186 Formal := First_Formal (Priv_Dep);
12188 while Present (Formal) loop
12190 if Etype (Formal) = Inc_T then
12191 Set_Etype (Formal, Full_T);
12194 Next_Formal (Formal);
12198 elsif Is_Overloadable (Priv_Dep) then
12200 if Is_Tagged_Type (Full_T) then
12202 -- Subprogram has an access parameter whose designated type
12203 -- was incomplete. Reexamine declaration now, because it may
12204 -- be a primitive operation of the full type.
12206 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
12207 Set_Is_Dispatching_Operation (Priv_Dep);
12208 Check_Controlling_Formals (Full_T, Priv_Dep);
12211 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
12213 -- Can happen during processing of a body before the completion
12214 -- of a TA type. Ignore, because spec is also on dependent list.
12218 -- Dependent is a subtype
12221 -- We build a new subtype indication using the full view of the
12222 -- incomplete parent. The discriminant constraints have been
12223 -- elaborated already at the point of the subtype declaration.
12225 New_Subt := Create_Itype (E_Void, N);
12227 if Has_Discriminants (Full_T) then
12228 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
12230 Disc_Constraint := No_Elist;
12233 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
12234 Set_Full_View (Priv_Dep, New_Subt);
12237 Next_Elmt (Inc_Elmt);
12240 end Process_Incomplete_Dependents;
12242 --------------------------------
12243 -- Process_Range_Expr_In_Decl --
12244 --------------------------------
12246 procedure Process_Range_Expr_In_Decl
12249 Check_List : List_Id := Empty_List;
12250 R_Check_Off : Boolean := False)
12253 R_Checks : Check_Result;
12254 Type_Decl : Node_Id;
12255 Def_Id : Entity_Id;
12258 Analyze_And_Resolve (R, Base_Type (T));
12260 if Nkind (R) = N_Range then
12261 Lo := Low_Bound (R);
12262 Hi := High_Bound (R);
12264 -- If there were errors in the declaration, try and patch up some
12265 -- common mistakes in the bounds. The cases handled are literals
12266 -- which are Integer where the expected type is Real and vice versa.
12267 -- These corrections allow the compilation process to proceed further
12268 -- along since some basic assumptions of the format of the bounds
12271 if Etype (R) = Any_Type then
12273 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
12275 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
12277 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
12279 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
12281 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
12283 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
12285 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
12287 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
12294 -- If the bounds of the range have been mistakenly given as
12295 -- string literals (perhaps in place of character literals),
12296 -- then an error has already been reported, but we rewrite
12297 -- the string literal as a bound of the range's type to
12298 -- avoid blowups in later processing that looks at static
12301 if Nkind (Lo) = N_String_Literal then
12303 Make_Attribute_Reference (Sloc (Lo),
12304 Attribute_Name => Name_First,
12305 Prefix => New_Reference_To (T, Sloc (Lo))));
12306 Analyze_And_Resolve (Lo);
12309 if Nkind (Hi) = N_String_Literal then
12311 Make_Attribute_Reference (Sloc (Hi),
12312 Attribute_Name => Name_First,
12313 Prefix => New_Reference_To (T, Sloc (Hi))));
12314 Analyze_And_Resolve (Hi);
12317 -- If bounds aren't scalar at this point then exit, avoiding
12318 -- problems with further processing of the range in this procedure.
12320 if not Is_Scalar_Type (Etype (Lo)) then
12324 -- Resolve (actually Sem_Eval) has checked that the bounds are in
12325 -- then range of the base type. Here we check whether the bounds
12326 -- are in the range of the subtype itself. Note that if the bounds
12327 -- represent the null range the Constraint_Error exception should
12330 -- ??? The following code should be cleaned up as follows
12331 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
12332 -- is done in the call to Range_Check (R, T); below
12333 -- 2. The use of R_Check_Off should be investigated and possibly
12334 -- removed, this would clean up things a bit.
12336 if Is_Null_Range (Lo, Hi) then
12340 -- Capture values of bounds and generate temporaries for them
12341 -- if needed, before applying checks, since checks may cause
12342 -- duplication of the expression without forcing evaluation.
12344 if Expander_Active then
12345 Force_Evaluation (Lo);
12346 Force_Evaluation (Hi);
12349 -- We use a flag here instead of suppressing checks on the
12350 -- type because the type we check against isn't necessarily
12351 -- the place where we put the check.
12353 if not R_Check_Off then
12354 R_Checks := Range_Check (R, T);
12355 Type_Decl := Parent (R);
12357 -- Look up tree to find an appropriate insertion point.
12358 -- This seems really junk code, and very brittle, couldn't
12359 -- we just use an insert actions call of some kind ???
12361 while Present (Type_Decl) and then not
12362 (Nkind (Type_Decl) = N_Full_Type_Declaration
12364 Nkind (Type_Decl) = N_Subtype_Declaration
12366 Nkind (Type_Decl) = N_Loop_Statement
12368 Nkind (Type_Decl) = N_Task_Type_Declaration
12370 Nkind (Type_Decl) = N_Single_Task_Declaration
12372 Nkind (Type_Decl) = N_Protected_Type_Declaration
12374 Nkind (Type_Decl) = N_Single_Protected_Declaration)
12376 Type_Decl := Parent (Type_Decl);
12379 -- Why would Type_Decl not be present??? Without this test,
12380 -- short regression tests fail.
12382 if Present (Type_Decl) then
12384 -- Case of loop statement (more comments ???)
12386 if Nkind (Type_Decl) = N_Loop_Statement then
12388 Indic : Node_Id := Parent (R);
12391 while Present (Indic) and then not
12392 (Nkind (Indic) = N_Subtype_Indication)
12394 Indic := Parent (Indic);
12397 if Present (Indic) then
12398 Def_Id := Etype (Subtype_Mark (Indic));
12400 Insert_Range_Checks
12406 Do_Before => True);
12410 -- All other cases (more comments ???)
12413 Def_Id := Defining_Identifier (Type_Decl);
12415 if (Ekind (Def_Id) = E_Record_Type
12416 and then Depends_On_Discriminant (R))
12418 (Ekind (Def_Id) = E_Protected_Type
12419 and then Has_Discriminants (Def_Id))
12421 Append_Range_Checks
12422 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
12425 Insert_Range_Checks
12426 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
12434 elsif Expander_Active then
12435 Get_Index_Bounds (R, Lo, Hi);
12436 Force_Evaluation (Lo);
12437 Force_Evaluation (Hi);
12439 end Process_Range_Expr_In_Decl;
12441 --------------------------------------
12442 -- Process_Real_Range_Specification --
12443 --------------------------------------
12445 procedure Process_Real_Range_Specification (Def : Node_Id) is
12446 Spec : constant Node_Id := Real_Range_Specification (Def);
12449 Err : Boolean := False;
12451 procedure Analyze_Bound (N : Node_Id);
12452 -- Analyze and check one bound
12454 -------------------
12455 -- Analyze_Bound --
12456 -------------------
12458 procedure Analyze_Bound (N : Node_Id) is
12460 Analyze_And_Resolve (N, Any_Real);
12462 if not Is_OK_Static_Expression (N) then
12463 Flag_Non_Static_Expr
12464 ("bound in real type definition is not static!", N);
12469 -- Start of processing for Process_Real_Range_Specification
12472 if Present (Spec) then
12473 Lo := Low_Bound (Spec);
12474 Hi := High_Bound (Spec);
12475 Analyze_Bound (Lo);
12476 Analyze_Bound (Hi);
12478 -- If error, clear away junk range specification
12481 Set_Real_Range_Specification (Def, Empty);
12484 end Process_Real_Range_Specification;
12486 ---------------------
12487 -- Process_Subtype --
12488 ---------------------
12490 function Process_Subtype
12492 Related_Nod : Node_Id;
12493 Related_Id : Entity_Id := Empty;
12494 Suffix : Character := ' ') return Entity_Id
12497 Def_Id : Entity_Id;
12498 Full_View_Id : Entity_Id;
12499 Subtype_Mark_Id : Entity_Id;
12501 procedure Check_Incomplete (T : Entity_Id);
12502 -- Called to verify that an incomplete type is not used prematurely
12504 ----------------------
12505 -- Check_Incomplete --
12506 ----------------------
12508 procedure Check_Incomplete (T : Entity_Id) is
12510 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
12511 Error_Msg_N ("invalid use of type before its full declaration", T);
12513 end Check_Incomplete;
12515 -- Start of processing for Process_Subtype
12518 -- Case of no constraints present
12520 if Nkind (S) /= N_Subtype_Indication then
12523 Check_Incomplete (S);
12525 -- Ada 2005 (AI-231): Static check
12527 if Ada_Version >= Ada_05
12528 and then Present (Parent (S))
12529 and then Null_Exclusion_Present (Parent (S))
12530 and then Nkind (Parent (S)) /= N_Access_To_Object_Definition
12531 and then not Is_Access_Type (Entity (S))
12534 ("(Ada 2005) null-exclusion part requires an access type", S);
12538 -- Case of constraint present, so that we have an N_Subtype_Indication
12539 -- node (this node is created only if constraints are present).
12543 Find_Type (Subtype_Mark (S));
12545 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
12547 (Nkind (Parent (S)) = N_Subtype_Declaration
12549 Is_Itype (Defining_Identifier (Parent (S))))
12551 Check_Incomplete (Subtype_Mark (S));
12555 Subtype_Mark_Id := Entity (Subtype_Mark (S));
12557 if Is_Unchecked_Union (Subtype_Mark_Id)
12558 and then Comes_From_Source (Related_Nod)
12561 ("cannot create subtype of Unchecked_Union", Related_Nod);
12564 -- Explicit subtype declaration case
12566 if Nkind (P) = N_Subtype_Declaration then
12567 Def_Id := Defining_Identifier (P);
12569 -- Explicit derived type definition case
12571 elsif Nkind (P) = N_Derived_Type_Definition then
12572 Def_Id := Defining_Identifier (Parent (P));
12574 -- Implicit case, the Def_Id must be created as an implicit type.
12575 -- The one exception arises in the case of concurrent types,
12576 -- array and access types, where other subsidiary implicit types
12577 -- may be created and must appear before the main implicit type.
12578 -- In these cases we leave Def_Id set to Empty as a signal that
12579 -- Create_Itype has not yet been called to create Def_Id.
12582 if Is_Array_Type (Subtype_Mark_Id)
12583 or else Is_Concurrent_Type (Subtype_Mark_Id)
12584 or else Is_Access_Type (Subtype_Mark_Id)
12588 -- For the other cases, we create a new unattached Itype,
12589 -- and set the indication to ensure it gets attached later.
12593 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12597 -- If the kind of constraint is invalid for this kind of type,
12598 -- then give an error, and then pretend no constraint was given.
12600 if not Is_Valid_Constraint_Kind
12601 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
12604 ("incorrect constraint for this kind of type", Constraint (S));
12606 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
12608 -- Make recursive call, having got rid of the bogus constraint
12610 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
12613 -- Remaining processing depends on type
12615 case Ekind (Subtype_Mark_Id) is
12617 when Access_Kind =>
12618 Constrain_Access (Def_Id, S, Related_Nod);
12621 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
12623 when Decimal_Fixed_Point_Kind =>
12624 Constrain_Decimal (Def_Id, S);
12626 when Enumeration_Kind =>
12627 Constrain_Enumeration (Def_Id, S);
12629 when Ordinary_Fixed_Point_Kind =>
12630 Constrain_Ordinary_Fixed (Def_Id, S);
12633 Constrain_Float (Def_Id, S);
12635 when Integer_Kind =>
12636 Constrain_Integer (Def_Id, S);
12638 when E_Record_Type |
12641 E_Incomplete_Type =>
12642 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
12644 when Private_Kind =>
12645 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
12646 Set_Private_Dependents (Def_Id, New_Elmt_List);
12648 -- In case of an invalid constraint prevent further processing
12649 -- since the type constructed is missing expected fields.
12651 if Etype (Def_Id) = Any_Type then
12655 -- If the full view is that of a task with discriminants,
12656 -- we must constrain both the concurrent type and its
12657 -- corresponding record type. Otherwise we will just propagate
12658 -- the constraint to the full view, if available.
12660 if Present (Full_View (Subtype_Mark_Id))
12661 and then Has_Discriminants (Subtype_Mark_Id)
12662 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
12665 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
12667 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
12668 Constrain_Concurrent (Full_View_Id, S,
12669 Related_Nod, Related_Id, Suffix);
12670 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
12671 Set_Full_View (Def_Id, Full_View_Id);
12674 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
12677 when Concurrent_Kind =>
12678 Constrain_Concurrent (Def_Id, S,
12679 Related_Nod, Related_Id, Suffix);
12682 Error_Msg_N ("invalid subtype mark in subtype indication", S);
12685 -- Size and Convention are always inherited from the base type
12687 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
12688 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
12693 end Process_Subtype;
12695 -----------------------------
12696 -- Record_Type_Declaration --
12697 -----------------------------
12699 procedure Record_Type_Declaration
12704 Def : constant Node_Id := Type_Definition (N);
12706 Is_Tagged : Boolean;
12707 Tag_Comp : Entity_Id;
12710 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
12711 -- if it detected an error for declaration T. This arises in the case of
12712 -- private tagged types where the full view omits the word tagged.
12714 Is_Tagged := Tagged_Present (Def)
12715 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
12717 -- Records constitute a scope for the component declarations within.
12718 -- The scope is created prior to the processing of these declarations.
12719 -- Discriminants are processed first, so that they are visible when
12720 -- processing the other components. The Ekind of the record type itself
12721 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
12723 -- Enter record scope
12727 -- These flags must be initialized before calling Process_Discriminants
12728 -- because this routine makes use of them.
12730 Set_Is_Tagged_Type (T, Is_Tagged);
12731 Set_Is_Limited_Record (T, Limited_Present (Def));
12733 -- Type is abstract if full declaration carries keyword, or if
12734 -- previous partial view did.
12736 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
12738 Set_Ekind (T, E_Record_Type);
12740 Init_Size_Align (T);
12742 Set_Stored_Constraint (T, No_Elist);
12744 -- If an incomplete or private type declaration was already given for
12745 -- the type, then this scope already exists, and the discriminants have
12746 -- been declared within. We must verify that the full declaration
12747 -- matches the incomplete one.
12749 Check_Or_Process_Discriminants (N, T, Prev);
12751 Set_Is_Constrained (T, not Has_Discriminants (T));
12752 Set_Has_Delayed_Freeze (T, True);
12754 -- For tagged types add a manually analyzed component corresponding
12755 -- to the component _tag, the corresponding piece of tree will be
12756 -- expanded as part of the freezing actions if it is not a CPP_Class.
12759 -- Do not add the tag unless we are in expansion mode.
12761 if Expander_Active then
12762 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
12763 Enter_Name (Tag_Comp);
12765 Set_Is_Tag (Tag_Comp);
12766 Set_Ekind (Tag_Comp, E_Component);
12767 Set_Etype (Tag_Comp, RTE (RE_Tag));
12768 Set_DT_Entry_Count (Tag_Comp, No_Uint);
12769 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
12770 Init_Component_Location (Tag_Comp);
12773 Make_Class_Wide_Type (T);
12774 Set_Primitive_Operations (T, New_Elmt_List);
12777 -- We must suppress range checks when processing the components
12778 -- of a record in the presence of discriminants, since we don't
12779 -- want spurious checks to be generated during their analysis, but
12780 -- must reset the Suppress_Range_Checks flags after having processed
12781 -- the record definition.
12783 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
12784 Set_Kill_Range_Checks (T, True);
12785 Record_Type_Definition (Def, Prev);
12786 Set_Kill_Range_Checks (T, False);
12788 Record_Type_Definition (Def, Prev);
12791 -- Exit from record scope
12794 end Record_Type_Declaration;
12796 ----------------------------
12797 -- Record_Type_Definition --
12798 ----------------------------
12800 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
12801 Component : Entity_Id;
12802 Ctrl_Components : Boolean := False;
12803 Final_Storage_Only : Boolean;
12807 if Ekind (Prev_T) = E_Incomplete_Type then
12808 T := Full_View (Prev_T);
12813 Final_Storage_Only := not Is_Controlled (T);
12815 -- If the component list of a record type is defined by the reserved
12816 -- word null and there is no discriminant part, then the record type has
12817 -- no components and all records of the type are null records (RM 3.7)
12818 -- This procedure is also called to process the extension part of a
12819 -- record extension, in which case the current scope may have inherited
12823 or else No (Component_List (Def))
12824 or else Null_Present (Component_List (Def))
12829 Analyze_Declarations (Component_Items (Component_List (Def)));
12831 if Present (Variant_Part (Component_List (Def))) then
12832 Analyze (Variant_Part (Component_List (Def)));
12836 -- After completing the semantic analysis of the record definition,
12837 -- record components, both new and inherited, are accessible. Set
12838 -- their kind accordingly.
12840 Component := First_Entity (Current_Scope);
12841 while Present (Component) loop
12843 if Ekind (Component) = E_Void then
12844 Set_Ekind (Component, E_Component);
12845 Init_Component_Location (Component);
12848 if Has_Task (Etype (Component)) then
12852 if Ekind (Component) /= E_Component then
12855 elsif Has_Controlled_Component (Etype (Component))
12856 or else (Chars (Component) /= Name_uParent
12857 and then Is_Controlled (Etype (Component)))
12859 Set_Has_Controlled_Component (T, True);
12860 Final_Storage_Only := Final_Storage_Only
12861 and then Finalize_Storage_Only (Etype (Component));
12862 Ctrl_Components := True;
12865 Next_Entity (Component);
12868 -- A type is Finalize_Storage_Only only if all its controlled
12869 -- components are so.
12871 if Ctrl_Components then
12872 Set_Finalize_Storage_Only (T, Final_Storage_Only);
12875 -- Place reference to end record on the proper entity, which may
12876 -- be a partial view.
12878 if Present (Def) then
12879 Process_End_Label (Def, 'e', Prev_T);
12881 end Record_Type_Definition;
12883 ------------------------
12884 -- Replace_Components --
12885 ------------------------
12887 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
12888 function Process (N : Node_Id) return Traverse_Result;
12894 function Process (N : Node_Id) return Traverse_Result is
12898 if Nkind (N) = N_Discriminant_Specification then
12899 Comp := First_Discriminant (Typ);
12901 while Present (Comp) loop
12902 if Chars (Comp) = Chars (Defining_Identifier (N)) then
12903 Set_Defining_Identifier (N, Comp);
12907 Next_Discriminant (Comp);
12910 elsif Nkind (N) = N_Component_Declaration then
12911 Comp := First_Component (Typ);
12913 while Present (Comp) loop
12914 if Chars (Comp) = Chars (Defining_Identifier (N)) then
12915 Set_Defining_Identifier (N, Comp);
12919 Next_Component (Comp);
12926 procedure Replace is new Traverse_Proc (Process);
12928 -- Start of processing for Replace_Components
12932 end Replace_Components;
12934 -------------------------------
12935 -- Set_Completion_Referenced --
12936 -------------------------------
12938 procedure Set_Completion_Referenced (E : Entity_Id) is
12940 -- If in main unit, mark entity that is a completion as referenced,
12941 -- warnings go on the partial view when needed.
12943 if In_Extended_Main_Source_Unit (E) then
12944 Set_Referenced (E);
12946 end Set_Completion_Referenced;
12948 ---------------------
12949 -- Set_Fixed_Range --
12950 ---------------------
12952 -- The range for fixed-point types is complicated by the fact that we
12953 -- do not know the exact end points at the time of the declaration. This
12954 -- is true for three reasons:
12956 -- A size clause may affect the fudging of the end-points
12957 -- A small clause may affect the values of the end-points
12958 -- We try to include the end-points if it does not affect the size
12960 -- This means that the actual end-points must be established at the
12961 -- point when the type is frozen. Meanwhile, we first narrow the range
12962 -- as permitted (so that it will fit if necessary in a small specified
12963 -- size), and then build a range subtree with these narrowed bounds.
12965 -- Set_Fixed_Range constructs the range from real literal values, and
12966 -- sets the range as the Scalar_Range of the given fixed-point type
12969 -- The parent of this range is set to point to the entity so that it
12970 -- is properly hooked into the tree (unlike normal Scalar_Range entries
12971 -- for other scalar types, which are just pointers to the range in the
12972 -- original tree, this would otherwise be an orphan).
12974 -- The tree is left unanalyzed. When the type is frozen, the processing
12975 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
12976 -- analyzed, and uses this as an indication that it should complete
12977 -- work on the range (it will know the final small and size values).
12979 procedure Set_Fixed_Range
12985 S : constant Node_Id :=
12987 Low_Bound => Make_Real_Literal (Loc, Lo),
12988 High_Bound => Make_Real_Literal (Loc, Hi));
12991 Set_Scalar_Range (E, S);
12993 end Set_Fixed_Range;
12995 ----------------------------------
12996 -- Set_Scalar_Range_For_Subtype --
12997 ----------------------------------
12999 procedure Set_Scalar_Range_For_Subtype
13000 (Def_Id : Entity_Id;
13004 Kind : constant Entity_Kind := Ekind (Def_Id);
13006 Set_Scalar_Range (Def_Id, R);
13008 -- We need to link the range into the tree before resolving it so
13009 -- that types that are referenced, including importantly the subtype
13010 -- itself, are properly frozen (Freeze_Expression requires that the
13011 -- expression be properly linked into the tree). Of course if it is
13012 -- already linked in, then we do not disturb the current link.
13014 if No (Parent (R)) then
13015 Set_Parent (R, Def_Id);
13018 -- Reset the kind of the subtype during analysis of the range, to
13019 -- catch possible premature use in the bounds themselves.
13021 Set_Ekind (Def_Id, E_Void);
13022 Process_Range_Expr_In_Decl (R, Subt);
13023 Set_Ekind (Def_Id, Kind);
13025 end Set_Scalar_Range_For_Subtype;
13027 --------------------------------------------------------
13028 -- Set_Stored_Constraint_From_Discriminant_Constraint --
13029 --------------------------------------------------------
13031 procedure Set_Stored_Constraint_From_Discriminant_Constraint
13035 -- Make sure set if encountered during
13036 -- Expand_To_Stored_Constraint
13038 Set_Stored_Constraint (E, No_Elist);
13040 -- Give it the right value
13042 if Is_Constrained (E) and then Has_Discriminants (E) then
13043 Set_Stored_Constraint (E,
13044 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
13047 end Set_Stored_Constraint_From_Discriminant_Constraint;
13049 -------------------------------------
13050 -- Signed_Integer_Type_Declaration --
13051 -------------------------------------
13053 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
13054 Implicit_Base : Entity_Id;
13055 Base_Typ : Entity_Id;
13058 Errs : Boolean := False;
13062 function Can_Derive_From (E : Entity_Id) return Boolean;
13063 -- Determine whether given bounds allow derivation from specified type
13065 procedure Check_Bound (Expr : Node_Id);
13066 -- Check bound to make sure it is integral and static. If not, post
13067 -- appropriate error message and set Errs flag
13069 ---------------------
13070 -- Can_Derive_From --
13071 ---------------------
13073 function Can_Derive_From (E : Entity_Id) return Boolean is
13074 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
13075 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
13078 -- Note we check both bounds against both end values, to deal with
13079 -- strange types like ones with a range of 0 .. -12341234.
13081 return Lo <= Lo_Val and then Lo_Val <= Hi
13083 Lo <= Hi_Val and then Hi_Val <= Hi;
13084 end Can_Derive_From;
13090 procedure Check_Bound (Expr : Node_Id) is
13092 -- If a range constraint is used as an integer type definition, each
13093 -- bound of the range must be defined by a static expression of some
13094 -- integer type, but the two bounds need not have the same integer
13095 -- type (Negative bounds are allowed.) (RM 3.5.4)
13097 if not Is_Integer_Type (Etype (Expr)) then
13099 ("integer type definition bounds must be of integer type", Expr);
13102 elsif not Is_OK_Static_Expression (Expr) then
13103 Flag_Non_Static_Expr
13104 ("non-static expression used for integer type bound!", Expr);
13107 -- The bounds are folded into literals, and we set their type to be
13108 -- universal, to avoid typing difficulties: we cannot set the type
13109 -- of the literal to the new type, because this would be a forward
13110 -- reference for the back end, and if the original type is user-
13111 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
13114 if Is_Entity_Name (Expr) then
13115 Fold_Uint (Expr, Expr_Value (Expr), True);
13118 Set_Etype (Expr, Universal_Integer);
13122 -- Start of processing for Signed_Integer_Type_Declaration
13125 -- Create an anonymous base type
13128 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
13130 -- Analyze and check the bounds, they can be of any integer type
13132 Lo := Low_Bound (Def);
13133 Hi := High_Bound (Def);
13135 -- Arbitrarily use Integer as the type if either bound had an error
13137 if Hi = Error or else Lo = Error then
13138 Base_Typ := Any_Integer;
13139 Set_Error_Posted (T, True);
13141 -- Here both bounds are OK expressions
13144 Analyze_And_Resolve (Lo, Any_Integer);
13145 Analyze_And_Resolve (Hi, Any_Integer);
13151 Hi := Type_High_Bound (Standard_Long_Long_Integer);
13152 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
13155 -- Find type to derive from
13157 Lo_Val := Expr_Value (Lo);
13158 Hi_Val := Expr_Value (Hi);
13160 if Can_Derive_From (Standard_Short_Short_Integer) then
13161 Base_Typ := Base_Type (Standard_Short_Short_Integer);
13163 elsif Can_Derive_From (Standard_Short_Integer) then
13164 Base_Typ := Base_Type (Standard_Short_Integer);
13166 elsif Can_Derive_From (Standard_Integer) then
13167 Base_Typ := Base_Type (Standard_Integer);
13169 elsif Can_Derive_From (Standard_Long_Integer) then
13170 Base_Typ := Base_Type (Standard_Long_Integer);
13172 elsif Can_Derive_From (Standard_Long_Long_Integer) then
13173 Base_Typ := Base_Type (Standard_Long_Long_Integer);
13176 Base_Typ := Base_Type (Standard_Long_Long_Integer);
13177 Error_Msg_N ("integer type definition bounds out of range", Def);
13178 Hi := Type_High_Bound (Standard_Long_Long_Integer);
13179 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
13183 -- Complete both implicit base and declared first subtype entities
13185 Set_Etype (Implicit_Base, Base_Typ);
13186 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
13187 Set_Size_Info (Implicit_Base, (Base_Typ));
13188 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
13189 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
13191 Set_Ekind (T, E_Signed_Integer_Subtype);
13192 Set_Etype (T, Implicit_Base);
13194 Set_Size_Info (T, (Implicit_Base));
13195 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
13196 Set_Scalar_Range (T, Def);
13197 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
13198 Set_Is_Constrained (T);
13199 end Signed_Integer_Type_Declaration;