1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Checks; use Checks;
31 with Elists; use Elists;
32 with Einfo; use Einfo;
33 with Errout; use Errout;
34 with Eval_Fat; use Eval_Fat;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Dist; use Exp_Dist;
37 with Exp_Util; use Exp_Util;
38 with Freeze; use Freeze;
39 with Itypes; use Itypes;
40 with Layout; use Layout;
42 with Lib.Xref; use Lib.Xref;
43 with Namet; use Namet;
44 with Nmake; use Nmake;
46 with Restrict; use Restrict;
47 with Rtsfind; use Rtsfind;
49 with Sem_Case; use Sem_Case;
50 with Sem_Cat; use Sem_Cat;
51 with Sem_Ch6; use Sem_Ch6;
52 with Sem_Ch7; use Sem_Ch7;
53 with Sem_Ch8; use Sem_Ch8;
54 with Sem_Ch13; use Sem_Ch13;
55 with Sem_Disp; use Sem_Disp;
56 with Sem_Dist; use Sem_Dist;
57 with Sem_Elim; use Sem_Elim;
58 with Sem_Eval; use Sem_Eval;
59 with Sem_Mech; use Sem_Mech;
60 with Sem_Res; use Sem_Res;
61 with Sem_Smem; use Sem_Smem;
62 with Sem_Type; use Sem_Type;
63 with Sem_Util; use Sem_Util;
64 with Stand; use Stand;
65 with Sinfo; use Sinfo;
66 with Snames; use Snames;
67 with Tbuild; use Tbuild;
68 with Ttypes; use Ttypes;
69 with Uintp; use Uintp;
70 with Urealp; use Urealp;
72 package body Sem_Ch3 is
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
78 procedure Build_Derived_Type
80 Parent_Type : Entity_Id;
81 Derived_Type : Entity_Id;
82 Is_Completion : Boolean;
83 Derive_Subps : Boolean := True);
84 -- Create and decorate a Derived_Type given the Parent_Type entity.
85 -- N is the N_Full_Type_Declaration node containing the derived type
86 -- definition. Parent_Type is the entity for the parent type in the derived
87 -- type definition and Derived_Type the actual derived type. Is_Completion
88 -- must be set to False if Derived_Type is the N_Defining_Identifier node
89 -- in N (ie Derived_Type = Defining_Identifier (N)). In this case N is not
90 -- the completion of a private type declaration. If Is_Completion is
91 -- set to True, N is the completion of a private type declaration and
92 -- Derived_Type is different from the defining identifier inside N (i.e.
93 -- Derived_Type /= Defining_Identifier (N)). Derive_Subps indicates whether
94 -- the parent subprograms should be derived. The only case where this
95 -- parameter is False is when Build_Derived_Type is recursively called to
96 -- process an implicit derived full type for a type derived from a private
97 -- type (in that case the subprograms must only be derived for the private
99 -- ??? These flags need a bit of re-examination and re-documentaion:
100 -- ??? are they both necessary (both seem related to the recursion)?
102 procedure Build_Derived_Access_Type
104 Parent_Type : Entity_Id;
105 Derived_Type : Entity_Id);
106 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
107 -- create an implicit base if the parent type is constrained or if the
108 -- subtype indication has a constraint.
110 procedure Build_Derived_Array_Type
112 Parent_Type : Entity_Id;
113 Derived_Type : Entity_Id);
114 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
115 -- create an implicit base if the parent type is constrained or if the
116 -- subtype indication has a constraint.
118 procedure Build_Derived_Concurrent_Type
120 Parent_Type : Entity_Id;
121 Derived_Type : Entity_Id);
122 -- Subsidiary procedure to Build_Derived_Type. For a derived task or pro-
123 -- tected type, inherit entries and protected subprograms, check legality
124 -- of discriminant constraints if any.
126 procedure Build_Derived_Enumeration_Type
128 Parent_Type : Entity_Id;
129 Derived_Type : Entity_Id);
130 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
131 -- type, we must create a new list of literals. Types derived from
132 -- Character and Wide_Character are special-cased.
134 procedure Build_Derived_Numeric_Type
136 Parent_Type : Entity_Id;
137 Derived_Type : Entity_Id);
138 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
139 -- an anonymous base type, and propagate constraint to subtype if needed.
141 procedure Build_Derived_Private_Type
143 Parent_Type : Entity_Id;
144 Derived_Type : Entity_Id;
145 Is_Completion : Boolean;
146 Derive_Subps : Boolean := True);
147 -- Substidiary procedure to Build_Derived_Type. This procedure is complex
148 -- because the parent may or may not have a completion, and the derivation
149 -- may itself be a completion.
151 procedure Build_Derived_Record_Type
153 Parent_Type : Entity_Id;
154 Derived_Type : Entity_Id;
155 Derive_Subps : Boolean := True);
156 -- Subsidiary procedure to Build_Derived_Type and
157 -- Analyze_Private_Extension_Declaration used for tagged and untagged
158 -- record types. All parameters are as in Build_Derived_Type except that
159 -- N, in addition to being an N_Full_Type_Declaration node, can also be an
160 -- N_Private_Extension_Declaration node. See the definition of this routine
161 -- for much more info. Derive_Subps indicates whether subprograms should
162 -- be derived from the parent type. The only case where Derive_Subps is
163 -- False is for an implicit derived full type for a type derived from a
164 -- private type (see Build_Derived_Type).
166 function Inherit_Components
168 Parent_Base : Entity_Id;
169 Derived_Base : Entity_Id;
171 Inherit_Discr : Boolean;
174 -- Called from Build_Derived_Record_Type to inherit the components of
175 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
176 -- For more information on derived types and component inheritance please
177 -- consult the comment above the body of Build_Derived_Record_Type.
179 -- N is the original derived type declaration.
180 -- Is_Tagged is set if we are dealing with tagged types.
181 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from
182 -- Parent_Base, otherwise no discriminants are inherited.
183 -- Discs gives the list of constraints that apply to Parent_Base in the
184 -- derived type declaration. If Discs is set to No_Elist, then we have the
185 -- following situation:
187 -- type Parent (D1..Dn : ..) is [tagged] record ...;
188 -- type Derived is new Parent [with ...];
190 -- which gets treated as
192 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
194 -- For untagged types the returned value is an association list:
195 -- (Old_Component => New_Component), where Old_Component is the Entity_Id
196 -- of a component in Parent_Base and New_Component is the Entity_Id of the
197 -- corresponding component in Derived_Base. For untagged records, this
198 -- association list is needed when copying the record declaration for the
199 -- derived base. In the tagged case the value returned is irrelevant.
201 procedure Build_Discriminal (Discrim : Entity_Id);
202 -- Create the discriminal corresponding to discriminant Discrim, that is
203 -- the parameter corresponding to Discrim to be used in initialization
204 -- procedures for the type where Discrim is a discriminant. Discriminals
205 -- are not used during semantic analysis, and are not fully defined
206 -- entities until expansion. Thus they are not given a scope until
207 -- intialization procedures are built.
209 function Build_Discriminant_Constraints
212 Derived_Def : Boolean := False)
214 -- Validate discriminant constraints, and return the list of the
215 -- constraints in order of discriminant declarations. T is the
216 -- discriminated unconstrained type. Def is the N_Subtype_Indication
217 -- node where the discriminants constraints for T are specified.
218 -- Derived_Def is True if we are building the discriminant constraints
219 -- in a derived type definition of the form "type D (...) is new T (xxx)".
220 -- In this case T is the parent type and Def is the constraint "(xxx)" on
221 -- T and this routine sets the Corresponding_Discriminant field of the
222 -- discriminants in the derived type D to point to the corresponding
223 -- discriminants in the parent type T.
225 procedure Build_Discriminated_Subtype
229 Related_Nod : Node_Id;
230 For_Access : Boolean := False);
231 -- Subsidiary procedure to Constrain_Discriminated_Type and to
232 -- Process_Incomplete_Dependents. Given
234 -- T (a possibly discriminated base type)
235 -- Def_Id (a very partially built subtype for T),
237 -- the call completes Def_Id to be the appropriate E_*_Subtype.
239 -- The Elist is the list of discriminant constraints if any (it is set to
240 -- No_Elist if T is not a discriminated type, and to an empty list if
241 -- T has discriminants but there are no discriminant constraints). The
242 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
243 -- The For_Access says whether or not this subtype is really constraining
244 -- an access type. That is its sole purpose is the designated type of an
245 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
246 -- is built to avoid freezing T when the access subtype is frozen.
248 function Build_Scalar_Bound
254 -- The bounds of a derived scalar type are conversions of the bounds of
255 -- the parent type. Optimize the representation if the bounds are literals.
256 -- Needs a more complete spec--what are the parameters exactly, and what
257 -- exactly is the returned value, and how is Bound affected???
259 procedure Build_Underlying_Full_View
263 -- If the completion of a private type is itself derived from a private
264 -- type, or if the full view of a private subtype is itself private, the
265 -- back-end has no way to compute the actual size of this type. We build
266 -- an internal subtype declaration of the proper parent type to convey
267 -- this information. This extra mechanism is needed because a full
268 -- view cannot itself have a full view (it would get clobbered during
271 procedure Check_Access_Discriminant_Requires_Limited
274 -- Check the restriction that the type to which an access discriminant
275 -- belongs must be a concurrent type or a descendant of a type with
276 -- the reserved word 'limited' in its declaration.
278 procedure Check_Delta_Expression (E : Node_Id);
279 -- Check that the expression represented by E is suitable for use as
280 -- a delta expression, i.e. it is of real type and is static.
282 procedure Check_Digits_Expression (E : Node_Id);
283 -- Check that the expression represented by E is suitable for use as
284 -- a digits expression, i.e. it is of integer type, positive and static.
286 procedure Check_Incomplete (T : Entity_Id);
287 -- Called to verify that an incomplete type is not used prematurely
289 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
290 -- Validate the initialization of an object declaration. T is the
291 -- required type, and Exp is the initialization expression.
293 procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id);
294 -- If T is the full declaration of an incomplete or private type, check
295 -- the conformance of the discriminants, otherwise process them.
297 procedure Check_Real_Bound (Bound : Node_Id);
298 -- Check given bound for being of real type and static. If not, post an
299 -- appropriate message, and rewrite the bound with the real literal zero.
301 procedure Constant_Redeclaration
305 -- Various checks on legality of full declaration of deferred constant.
306 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
307 -- node. The caller has not yet set any attributes of this entity.
309 procedure Convert_Scalar_Bounds
311 Parent_Type : Entity_Id;
312 Derived_Type : Entity_Id;
314 -- For derived scalar types, convert the bounds in the type definition
315 -- to the derived type, and complete their analysis.
317 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
318 -- Copies attributes from array base type T2 to array base type T1.
319 -- Copies only attributes that apply to base types, but not subtypes.
321 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
322 -- Copies attributes from array subtype T2 to array subtype T1. Copies
323 -- attributes that apply to both subtypes and base types.
325 procedure Create_Constrained_Components
329 Constraints : Elist_Id);
330 -- Build the list of entities for a constrained discriminated record
331 -- subtype. If a component depends on a discriminant, replace its subtype
332 -- using the discriminant values in the discriminant constraint.
333 -- Subt is the defining identifier for the subtype whose list of
334 -- constrained entities we will create. Decl_Node is the type declaration
335 -- node where we will attach all the itypes created. Typ is the base
336 -- discriminated type for the subtype Subt. Constraints is the list of
337 -- discriminant constraints for Typ.
339 function Constrain_Component_Type
340 (Compon_Type : Entity_Id;
341 Constrained_Typ : Entity_Id;
342 Related_Node : Node_Id;
344 Constraints : Elist_Id)
346 -- Given a discriminated base type Typ, a list of discriminant constraint
347 -- Constraints for Typ and the type of a component of Typ, Compon_Type,
348 -- create and return the type corresponding to Compon_type where all
349 -- discriminant references are replaced with the corresponding
350 -- constraint. If no discriminant references occurr in Compon_Typ then
351 -- return it as is. Constrained_Typ is the final constrained subtype to
352 -- which the constrained Compon_Type belongs. Related_Node is the node
353 -- where we will attach all the itypes created.
355 procedure Constrain_Access
356 (Def_Id : in out Entity_Id;
358 Related_Nod : Node_Id);
359 -- Apply a list of constraints to an access type. If Def_Id is empty,
360 -- it is an anonymous type created for a subtype indication. In that
361 -- case it is created in the procedure and attached to Related_Nod.
363 procedure Constrain_Array
364 (Def_Id : in out Entity_Id;
366 Related_Nod : Node_Id;
367 Related_Id : Entity_Id;
369 -- Apply a list of index constraints to an unconstrained array type. The
370 -- first parameter is the entity for the resulting subtype. A value of
371 -- Empty for Def_Id indicates that an implicit type must be created, but
372 -- creation is delayed (and must be done by this procedure) because other
373 -- subsidiary implicit types must be created first (which is why Def_Id
374 -- is an in/out parameter). Related_Nod gives the place where this type has
375 -- to be inserted in the tree. The Related_Id and Suffix parameters are
376 -- used to build the associated Implicit type name.
378 procedure Constrain_Concurrent
379 (Def_Id : in out Entity_Id;
381 Related_Nod : Node_Id;
382 Related_Id : Entity_Id;
384 -- Apply list of discriminant constraints to an unconstrained concurrent
387 -- SI is the N_Subtype_Indication node containing the constraint and
388 -- the unconstrained type to constrain.
390 -- Def_Id is the entity for the resulting constrained subtype. A
391 -- value of Empty for Def_Id indicates that an implicit type must be
392 -- created, but creation is delayed (and must be done by this procedure)
393 -- because other subsidiary implicit types must be created first (which
394 -- is why Def_Id is an in/out parameter).
396 -- Related_Nod gives the place where this type has to be inserted
399 -- The last two arguments are used to create its external name if needed.
401 function Constrain_Corresponding_Record
402 (Prot_Subt : Entity_Id;
403 Corr_Rec : Entity_Id;
404 Related_Nod : Node_Id;
405 Related_Id : Entity_Id)
407 -- When constraining a protected type or task type with discriminants,
408 -- constrain the corresponding record with the same discriminant values.
410 procedure Constrain_Decimal
413 Related_Nod : Node_Id);
414 -- Constrain a decimal fixed point type with a digits constraint and/or a
415 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
417 procedure Constrain_Discriminated_Type
420 Related_Nod : Node_Id;
421 For_Access : Boolean := False);
422 -- Process discriminant constraints of composite type. Verify that values
423 -- have been provided for all discriminants, that the original type is
424 -- unconstrained, and that the types of the supplied expressions match
425 -- the discriminant types. The first three parameters are like in routine
426 -- Constrain_Concurrent. See Build_Discrimated_Subtype for an explanation
429 procedure Constrain_Enumeration
432 Related_Nod : Node_Id);
433 -- Constrain an enumeration type with a range constraint. This is
434 -- identical to Constrain_Integer, but for the Ekind of the
435 -- resulting subtype.
437 procedure Constrain_Float
440 Related_Nod : Node_Id);
441 -- Constrain a floating point type with either a digits constraint
442 -- and/or a range constraint, building a E_Floating_Point_Subtype.
444 procedure Constrain_Index
447 Related_Nod : Node_Id;
448 Related_Id : Entity_Id;
451 -- Process an index constraint in a constrained array declaration.
452 -- The constraint can be a subtype name, or a range with or without
453 -- an explicit subtype mark. The index is the corresponding index of the
454 -- unconstrained array. The Related_Id and Suffix parameters are used to
455 -- build the associated Implicit type name.
457 procedure Constrain_Integer
460 Related_Nod : Node_Id);
461 -- Build subtype of a signed or modular integer type.
463 procedure Constrain_Ordinary_Fixed
466 Related_Nod : Node_Id);
467 -- Constrain an ordinary fixed point type with a range constraint, and
468 -- build an E_Ordinary_Fixed_Point_Subtype entity.
470 procedure Copy_And_Swap (Privat, Full : Entity_Id);
471 -- Copy the Privat entity into the entity of its full declaration
472 -- then swap the two entities in such a manner that the former private
473 -- type is now seen as a full type.
475 procedure Copy_Private_To_Full (Priv, Full : Entity_Id);
476 -- Initialize the full view declaration with the relevant fields
477 -- from the private view.
479 procedure Decimal_Fixed_Point_Type_Declaration
482 -- Create a new decimal fixed point type, and apply the constraint to
483 -- obtain a subtype of this new type.
485 procedure Complete_Private_Subtype
488 Full_Base : Entity_Id;
489 Related_Nod : Node_Id);
490 -- Complete the implicit full view of a private subtype by setting
491 -- the appropriate semantic fields. If the full view of the parent is
492 -- a record type, build constrained components of subtype.
494 procedure Derived_Standard_Character
496 Parent_Type : Entity_Id;
497 Derived_Type : Entity_Id);
498 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
499 -- derivations from types Standard.Character and Standard.Wide_Character.
501 procedure Derived_Type_Declaration
504 Is_Completion : Boolean);
505 -- Process a derived type declaration. This routine will invoke
506 -- Build_Derived_Type to process the actual derived type definition.
507 -- Parameters N and Is_Completion have the same meaning as in
508 -- Build_Derived_Type. T is the N_Defining_Identifier for the entity
509 -- defined in the N_Full_Type_Declaration node N, that is T is the
512 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
513 -- Given a subtype indication S (which is really an N_Subtype_Indication
514 -- node or a plain N_Identifier), find the type of the subtype mark.
516 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
517 -- Insert each literal in symbol table, as an overloadable identifier
518 -- Each enumeration type is mapped into a sequence of integers, and
519 -- each literal is defined as a constant with integer value. If any
520 -- of the literals are character literals, the type is a character
521 -- type, which means that strings are legal aggregates for arrays of
522 -- components of the type.
524 procedure Expand_Others_Choice
525 (Case_Table : Choice_Table_Type;
526 Others_Choice : Node_Id;
527 Choice_Type : Entity_Id);
528 -- In the case of a variant part of a record type that has an OTHERS
529 -- choice, this procedure expands the OTHERS into the actual choices
530 -- that it represents. This new list of choice nodes is attached to
531 -- the OTHERS node via the Others_Discrete_Choices field. The Case_Table
532 -- contains all choices that have been given explicitly in the variant.
534 function Find_Type_Of_Object
536 Related_Nod : Node_Id)
538 -- Get type entity for object referenced by Obj_Def, attaching the
539 -- implicit types generated to Related_Nod
541 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
542 -- Create a new float, and apply the constraint to obtain subtype of it
544 function Has_Range_Constraint (N : Node_Id) return Boolean;
545 -- Given an N_Subtype_Indication node N, return True if a range constraint
546 -- is present, either directly, or as part of a digits or delta constraint.
547 -- In addition, a digits constraint in the decimal case returns True, since
548 -- it establishes a default range if no explicit range is present.
550 function Is_Valid_Constraint_Kind
552 Constraint_Kind : Node_Kind)
554 -- Returns True if it is legal to apply the given kind of constraint
555 -- to the given kind of type (index constraint to an array type,
558 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
559 -- Create new modular type. Verify that modulus is in bounds and is
560 -- a power of two (implementation restriction).
562 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id);
563 -- Create an abbreviated declaration for an operator in order to
564 -- materialize minimally operators on derived types.
566 procedure Ordinary_Fixed_Point_Type_Declaration
569 -- Create a new ordinary fixed point type, and apply the constraint
570 -- to obtain subtype of it.
572 procedure Prepare_Private_Subtype_Completion
574 Related_Nod : Node_Id);
575 -- Id is a subtype of some private type. Creates the full declaration
576 -- associated with Id whenever possible, i.e. when the full declaration
577 -- of the base type is already known. Records each subtype into
578 -- Private_Dependents of the base type.
580 procedure Process_Incomplete_Dependents
584 -- Process all entities that depend on an incomplete type. There include
585 -- subtypes, subprogram types that mention the incomplete type in their
586 -- profiles, and subprogram with access parameters that designate the
589 -- Inc_T is the defining identifier of an incomplete type declaration, its
590 -- Ekind is E_Incomplete_Type.
592 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
594 -- Full_T is N's defining identifier.
596 -- Subtypes of incomplete types with discriminants are completed when the
597 -- parent type is. This is simpler than private subtypes, because they can
598 -- only appear in the same scope, and there is no need to exchange views.
599 -- Similarly, access_to_subprogram types may have a parameter or a return
600 -- type that is an incomplete type, and that must be replaced with the
603 -- If the full type is tagged, subprogram with access parameters that
604 -- designated the incomplete may be primitive operations of the full type,
605 -- and have to be processed accordingly.
607 procedure Process_Real_Range_Specification (Def : Node_Id);
608 -- Given the type definition for a real type, this procedure processes
609 -- and checks the real range specification of this type definition if
610 -- one is present. If errors are found, error messages are posted, and
611 -- the Real_Range_Specification of Def is reset to Empty.
613 procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id);
614 -- Process a record type declaration (for both untagged and tagged
615 -- records). Parameters T and N are exactly like in procedure
616 -- Derived_Type_Declaration, except that no flag Is_Completion is
617 -- needed for this routine.
619 procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id);
620 -- This routine is used to process the actual record type definition
621 -- (both for untagged and tagged records). Def is a record type
622 -- definition node. This procedure analyzes the components in this
623 -- record type definition. T is the entity for the enclosing record
624 -- type. It is provided so that its Has_Task flag can be set if any of
625 -- the component have Has_Task set.
627 procedure Set_Fixed_Range
632 -- Build a range node with the given bounds and set it as the Scalar_Range
633 -- of the given fixed-point type entity. Loc is the source location used
634 -- for the constructed range. See body for further details.
636 procedure Set_Scalar_Range_For_Subtype
640 Related_Nod : Node_Id);
641 -- This routine is used to set the scalar range field for a subtype
642 -- given Def_Id, the entity for the subtype, and R, the range expression
643 -- for the scalar range. Subt provides the parent subtype to be used
644 -- to analyze, resolve, and check the given range.
646 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
647 -- Create a new signed integer entity, and apply the constraint to obtain
648 -- the required first named subtype of this type.
650 -----------------------
651 -- Access_Definition --
652 -----------------------
654 function Access_Definition
655 (Related_Nod : Node_Id;
659 Anon_Type : constant Entity_Id :=
660 Create_Itype (E_Anonymous_Access_Type, Related_Nod,
661 Scope_Id => Scope (Current_Scope));
662 Desig_Type : Entity_Id;
665 if Is_Entry (Current_Scope)
666 and then Is_Task_Type (Etype (Scope (Current_Scope)))
668 Error_Msg_N ("task entries cannot have access parameters", N);
671 Find_Type (Subtype_Mark (N));
672 Desig_Type := Entity (Subtype_Mark (N));
674 Set_Directly_Designated_Type
675 (Anon_Type, Desig_Type);
676 Set_Etype (Anon_Type, Anon_Type);
677 Init_Size_Align (Anon_Type);
678 Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type));
680 -- The anonymous access type is as public as the discriminated type or
681 -- subprogram that defines it. It is imported (for back-end purposes)
682 -- if the designated type is.
684 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
685 Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type));
687 -- The context is either a subprogram declaration or an access
688 -- discriminant, in a private or a full type declaration. In
689 -- the case of a subprogram, If the designated type is incomplete,
690 -- the operation will be a primitive operation of the full type, to
691 -- be updated subsequently.
693 if Ekind (Desig_Type) = E_Incomplete_Type
694 and then Is_Overloadable (Current_Scope)
696 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
697 Set_Has_Delayed_Freeze (Current_Scope);
701 end Access_Definition;
703 -----------------------------------
704 -- Access_Subprogram_Declaration --
705 -----------------------------------
707 procedure Access_Subprogram_Declaration
711 Formals : constant List_Id := Parameter_Specifications (T_Def);
713 Desig_Type : constant Entity_Id :=
714 Create_Itype (E_Subprogram_Type, Parent (T_Def));
717 if Nkind (T_Def) = N_Access_Function_Definition then
718 Analyze (Subtype_Mark (T_Def));
719 Set_Etype (Desig_Type, Entity (Subtype_Mark (T_Def)));
721 Set_Etype (Desig_Type, Standard_Void_Type);
724 if Present (Formals) then
725 New_Scope (Desig_Type);
726 Process_Formals (Desig_Type, Formals, Parent (T_Def));
728 -- A bit of a kludge here, End_Scope requires that the parent
729 -- pointer be set to something reasonable, but Itypes don't
730 -- have parent pointers. So we set it and then unset it ???
731 -- If and when Itypes have proper parent pointers to their
732 -- declarations, this kludge can be removed.
734 Set_Parent (Desig_Type, T_Name);
736 Set_Parent (Desig_Type, Empty);
739 -- The return type and/or any parameter type may be incomplete. Mark
740 -- the subprogram_type as depending on the incomplete type, so that
741 -- it can be updated when the full type declaration is seen.
743 if Present (Formals) then
744 Formal := First_Formal (Desig_Type);
746 while Present (Formal) loop
748 if Ekind (Formal) /= E_In_Parameter
749 and then Nkind (T_Def) = N_Access_Function_Definition
751 Error_Msg_N ("functions can only have IN parameters", Formal);
754 if Ekind (Etype (Formal)) = E_Incomplete_Type then
755 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
756 Set_Has_Delayed_Freeze (Desig_Type);
759 Next_Formal (Formal);
763 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
764 and then not Has_Delayed_Freeze (Desig_Type)
766 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
767 Set_Has_Delayed_Freeze (Desig_Type);
770 Check_Delayed_Subprogram (Desig_Type);
772 if Protected_Present (T_Def) then
773 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
774 Set_Convention (Desig_Type, Convention_Protected);
776 Set_Ekind (T_Name, E_Access_Subprogram_Type);
779 Set_Etype (T_Name, T_Name);
780 Init_Size_Align (T_Name);
781 Set_Directly_Designated_Type (T_Name, Desig_Type);
783 Check_Restriction (No_Access_Subprograms, T_Def);
784 end Access_Subprogram_Declaration;
786 ----------------------------
787 -- Access_Type_Declaration --
788 ----------------------------
790 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
791 S : constant Node_Id := Subtype_Indication (Def);
792 P : constant Node_Id := Parent (Def);
795 -- Check for permissible use of incomplete type
797 if Nkind (S) /= N_Subtype_Indication then
800 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
801 Set_Directly_Designated_Type (T, Entity (S));
803 Set_Directly_Designated_Type (T,
804 Process_Subtype (S, P, T, 'P'));
808 Set_Directly_Designated_Type (T,
809 Process_Subtype (S, P, T, 'P'));
812 if All_Present (Def) or Constant_Present (Def) then
813 Set_Ekind (T, E_General_Access_Type);
815 Set_Ekind (T, E_Access_Type);
818 if Base_Type (Designated_Type (T)) = T then
819 Error_Msg_N ("access type cannot designate itself", S);
824 -- If the type has appeared already in a with_type clause, it is
825 -- frozen and the pointer size is already set. Else, initialize.
827 if not From_With_Type (T) then
831 Set_Is_Access_Constant (T, Constant_Present (Def));
833 -- If designated type is an imported tagged type, indicate that the
834 -- access type is also imported, and therefore restricted in its use.
835 -- The access type may already be imported, so keep setting otherwise.
837 if From_With_Type (Designated_Type (T)) then
838 Set_From_With_Type (T);
841 -- Note that Has_Task is always false, since the access type itself
842 -- is not a task type. See Einfo for more description on this point.
843 -- Exactly the same consideration applies to Has_Controlled_Component.
845 Set_Has_Task (T, False);
846 Set_Has_Controlled_Component (T, False);
847 end Access_Type_Declaration;
849 -----------------------------------
850 -- Analyze_Component_Declaration --
851 -----------------------------------
853 procedure Analyze_Component_Declaration (N : Node_Id) is
854 Id : constant Entity_Id := Defining_Identifier (N);
859 Generate_Definition (Id);
861 T := Find_Type_Of_Object (Subtype_Indication (N), N);
863 -- If the component declaration includes a default expression, then we
864 -- check that the component is not of a limited type (RM 3.7(5)),
865 -- and do the special preanalysis of the expression (see section on
866 -- "Handling of Default Expressions" in the spec of package Sem).
868 if Present (Expression (N)) then
869 Analyze_Default_Expression (Expression (N), T);
870 Check_Initialization (T, Expression (N));
873 -- The parent type may be a private view with unknown discriminants,
874 -- and thus unconstrained. Regular components must be constrained.
876 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
878 ("unconstrained subtype in component declaration",
879 Subtype_Indication (N));
881 -- Components cannot be abstract, except for the special case of
882 -- the _Parent field (case of extending an abstract tagged type)
884 elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then
885 Error_Msg_N ("type of a component cannot be abstract", N);
889 Set_Is_Aliased (Id, Aliased_Present (N));
891 -- If the this component is private (or depends on a private type),
892 -- flag the record type to indicate that some operations are not
895 P := Private_Component (T);
898 -- Check for circular definitions.
901 Set_Etype (Id, Any_Type);
903 -- There is a gap in the visibility of operations only if the
904 -- component type is not defined in the scope of the record type.
906 elsif Scope (P) = Scope (Current_Scope) then
909 elsif Is_Limited_Type (P) then
910 Set_Is_Limited_Composite (Current_Scope);
913 Set_Is_Private_Composite (Current_Scope);
918 and then Is_Limited_Type (T)
919 and then Chars (Id) /= Name_uParent
920 and then Is_Tagged_Type (Current_Scope)
922 if Is_Derived_Type (Current_Scope)
923 and then not Is_Limited_Record (Root_Type (Current_Scope))
926 ("extension of nonlimited type cannot have limited components",
928 Set_Etype (Id, Any_Type);
929 Set_Is_Limited_Composite (Current_Scope, False);
931 elsif not Is_Derived_Type (Current_Scope)
932 and then not Is_Limited_Record (Current_Scope)
934 Error_Msg_N ("nonlimited type cannot have limited components", N);
935 Set_Etype (Id, Any_Type);
936 Set_Is_Limited_Composite (Current_Scope, False);
940 Set_Original_Record_Component (Id, Id);
941 end Analyze_Component_Declaration;
943 --------------------------
944 -- Analyze_Declarations --
945 --------------------------
947 procedure Analyze_Declarations (L : List_Id) is
950 Freeze_From : Entity_Id := Empty;
953 -- Adjust D not to include implicit label declarations, since these
954 -- have strange Sloc values that result in elaboration check problems.
956 procedure Adjust_D is
958 while Present (Prev (D))
959 and then Nkind (D) = N_Implicit_Label_Declaration
965 -- Start of processing for Analyze_Declarations
969 while Present (D) loop
971 -- Complete analysis of declaration
974 Next_Node := Next (D);
976 if No (Freeze_From) then
977 Freeze_From := First_Entity (Current_Scope);
980 -- At the end of a declarative part, freeze remaining entities
981 -- declared in it. The end of the visible declarations of a
982 -- package specification is not the end of a declarative part
983 -- if private declarations are present. The end of a package
984 -- declaration is a freezing point only if it a library package.
985 -- A task definition or protected type definition is not a freeze
986 -- point either. Finally, we do not freeze entities in generic
987 -- scopes, because there is no code generated for them and freeze
988 -- nodes will be generated for the instance.
990 -- The end of a package instantiation is not a freeze point, but
991 -- for now we make it one, because the generic body is inserted
992 -- (currently) immediately after. Generic instantiations will not
993 -- be a freeze point once delayed freezing of bodies is implemented.
994 -- (This is needed in any case for early instantiations ???).
996 if No (Next_Node) then
997 if Nkind (Parent (L)) = N_Component_List
998 or else Nkind (Parent (L)) = N_Task_Definition
999 or else Nkind (Parent (L)) = N_Protected_Definition
1003 elsif Nkind (Parent (L)) /= N_Package_Specification then
1005 if Nkind (Parent (L)) = N_Package_Body then
1006 Freeze_From := First_Entity (Current_Scope);
1010 Freeze_All (Freeze_From, D);
1011 Freeze_From := Last_Entity (Current_Scope);
1013 elsif Scope (Current_Scope) /= Standard_Standard
1014 and then not Is_Child_Unit (Current_Scope)
1015 and then No (Generic_Parent (Parent (L)))
1019 elsif L /= Visible_Declarations (Parent (L))
1020 or else No (Private_Declarations (Parent (L)))
1021 or else Is_Empty_List (Private_Declarations (Parent (L)))
1024 Freeze_All (Freeze_From, D);
1025 Freeze_From := Last_Entity (Current_Scope);
1028 -- If next node is a body then freeze all types before the body.
1029 -- An exception occurs for expander generated bodies, which can
1030 -- be recognized by their already being analyzed. The expander
1031 -- ensures that all types needed by these bodies have been frozen
1032 -- but it is not necessary to freeze all types (and would be wrong
1033 -- since it would not correspond to an RM defined freeze point).
1035 elsif not Analyzed (Next_Node)
1036 and then (Nkind (Next_Node) = N_Subprogram_Body
1037 or else Nkind (Next_Node) = N_Entry_Body
1038 or else Nkind (Next_Node) = N_Package_Body
1039 or else Nkind (Next_Node) = N_Protected_Body
1040 or else Nkind (Next_Node) = N_Task_Body
1041 or else Nkind (Next_Node) in N_Body_Stub)
1044 Freeze_All (Freeze_From, D);
1045 Freeze_From := Last_Entity (Current_Scope);
1051 end Analyze_Declarations;
1053 --------------------------------
1054 -- Analyze_Default_Expression --
1055 --------------------------------
1057 procedure Analyze_Default_Expression (N : Node_Id; T : Entity_Id) is
1058 Save_In_Default_Expression : constant Boolean := In_Default_Expression;
1061 In_Default_Expression := True;
1062 Pre_Analyze_And_Resolve (N, T);
1063 In_Default_Expression := Save_In_Default_Expression;
1064 end Analyze_Default_Expression;
1066 ----------------------------------
1067 -- Analyze_Incomplete_Type_Decl --
1068 ----------------------------------
1070 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
1071 F : constant Boolean := Is_Pure (Current_Scope);
1075 Generate_Definition (Defining_Identifier (N));
1077 -- Process an incomplete declaration. The identifier must not have been
1078 -- declared already in the scope. However, an incomplete declaration may
1079 -- appear in the private part of a package, for a private type that has
1080 -- already been declared.
1082 -- In this case, the discriminants (if any) must match.
1084 T := Find_Type_Name (N);
1086 Set_Ekind (T, E_Incomplete_Type);
1087 Init_Size_Align (T);
1088 Set_Is_First_Subtype (T, True);
1092 Set_Girder_Constraint (T, No_Elist);
1094 if Present (Discriminant_Specifications (N)) then
1095 Process_Discriminants (N);
1100 -- If the type has discriminants, non-trivial subtypes may be
1101 -- be declared before the full view of the type. The full views
1102 -- of those subtypes will be built after the full view of the type.
1104 Set_Private_Dependents (T, New_Elmt_List);
1106 end Analyze_Incomplete_Type_Decl;
1108 -----------------------------
1109 -- Analyze_Itype_Reference --
1110 -----------------------------
1112 -- Nothing to do. This node is placed in the tree only for the benefit
1113 -- of Gigi processing, and has no effect on the semantic processing.
1115 procedure Analyze_Itype_Reference (N : Node_Id) is
1117 pragma Assert (Is_Itype (Itype (N)));
1119 end Analyze_Itype_Reference;
1121 --------------------------------
1122 -- Analyze_Number_Declaration --
1123 --------------------------------
1125 procedure Analyze_Number_Declaration (N : Node_Id) is
1126 Id : constant Entity_Id := Defining_Identifier (N);
1127 E : constant Node_Id := Expression (N);
1129 Index : Interp_Index;
1133 Generate_Definition (Id);
1136 -- This is an optimization of a common case of an integer literal
1138 if Nkind (E) = N_Integer_Literal then
1139 Set_Is_Static_Expression (E, True);
1140 Set_Etype (E, Universal_Integer);
1142 Set_Etype (Id, Universal_Integer);
1143 Set_Ekind (Id, E_Named_Integer);
1144 Set_Is_Frozen (Id, True);
1148 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1152 -- Verify that the expression is static and numeric. If
1153 -- the expression is overloaded, we apply the preference
1154 -- rule that favors root numeric types.
1156 if not Is_Overloaded (E) then
1161 Get_First_Interp (E, Index, It);
1163 while Present (It.Typ) loop
1164 if (Is_Integer_Type (It.Typ)
1165 or else Is_Real_Type (It.Typ))
1166 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
1168 if T = Any_Type then
1171 elsif It.Typ = Universal_Real
1172 or else It.Typ = Universal_Integer
1174 -- Choose universal interpretation over any other.
1181 Get_Next_Interp (Index, It);
1185 if Is_Integer_Type (T) then
1187 Set_Etype (Id, Universal_Integer);
1188 Set_Ekind (Id, E_Named_Integer);
1190 elsif Is_Real_Type (T) then
1192 -- Because the real value is converted to universal_real, this
1193 -- is a legal context for a universal fixed expression.
1195 if T = Universal_Fixed then
1197 Loc : constant Source_Ptr := Sloc (N);
1198 Conv : constant Node_Id := Make_Type_Conversion (Loc,
1200 New_Occurrence_Of (Universal_Real, Loc),
1201 Expression => Relocate_Node (E));
1208 elsif T = Any_Fixed then
1209 Error_Msg_N ("illegal context for mixed mode operation", E);
1211 -- Expression is of the form : universal_fixed * integer.
1212 -- Try to resolve as universal_real.
1214 T := Universal_Real;
1219 Set_Etype (Id, Universal_Real);
1220 Set_Ekind (Id, E_Named_Real);
1223 Wrong_Type (E, Any_Numeric);
1226 Set_Ekind (Id, E_Constant);
1227 Set_Not_Source_Assigned (Id, True);
1228 Set_Is_True_Constant (Id, True);
1232 if Nkind (E) = N_Integer_Literal
1233 or else Nkind (E) = N_Real_Literal
1235 Set_Etype (E, Etype (Id));
1238 if not Is_OK_Static_Expression (E) then
1239 Error_Msg_N ("non-static expression used in number declaration", E);
1240 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
1241 Set_Etype (E, Any_Type);
1244 end Analyze_Number_Declaration;
1246 --------------------------------
1247 -- Analyze_Object_Declaration --
1248 --------------------------------
1250 procedure Analyze_Object_Declaration (N : Node_Id) is
1251 Loc : constant Source_Ptr := Sloc (N);
1252 Id : constant Entity_Id := Defining_Identifier (N);
1256 E : Node_Id := Expression (N);
1257 -- E is set to Expression (N) throughout this routine. When
1258 -- Expression (N) is modified, E is changed accordingly.
1260 Prev_Entity : Entity_Id := Empty;
1262 function Build_Default_Subtype return Entity_Id;
1263 -- If the object is limited or aliased, and if the type is unconstrained
1264 -- and there is no expression, the discriminants cannot be modified and
1265 -- the subtype of the object is constrained by the defaults, so it is
1266 -- worthile building the corresponding subtype.
1268 ---------------------------
1269 -- Build_Default_Subtype --
1270 ---------------------------
1272 function Build_Default_Subtype return Entity_Id is
1274 Constraints : List_Id := New_List;
1279 Disc := First_Discriminant (T);
1281 if No (Discriminant_Default_Value (Disc)) then
1282 return T; -- previous error.
1285 Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
1286 while Present (Disc) loop
1289 Discriminant_Default_Value (Disc)), Constraints);
1290 Next_Discriminant (Disc);
1294 Make_Subtype_Declaration (Loc,
1295 Defining_Identifier => Act,
1296 Subtype_Indication =>
1297 Make_Subtype_Indication (Loc,
1298 Subtype_Mark => New_Occurrence_Of (T, Loc),
1300 Make_Index_Or_Discriminant_Constraint
1301 (Loc, Constraints)));
1303 Insert_Before (N, Decl);
1306 end Build_Default_Subtype;
1308 -- Start of processing for Analyze_Object_Declaration
1311 -- There are three kinds of implicit types generated by an
1312 -- object declaration:
1314 -- 1. Those for generated by the original Object Definition
1316 -- 2. Those generated by the Expression
1318 -- 3. Those used to constrained the Object Definition with the
1319 -- expression constraints when it is unconstrained
1321 -- They must be generated in this order to avoid order of elaboration
1322 -- issues. Thus the first step (after entering the name) is to analyze
1323 -- the object definition.
1325 if Constant_Present (N) then
1326 Prev_Entity := Current_Entity_In_Scope (Id);
1328 -- If homograph is an implicit subprogram, it is overridden by the
1329 -- current declaration.
1331 if Present (Prev_Entity)
1332 and then Is_Overloadable (Prev_Entity)
1333 and then Is_Inherited_Operation (Prev_Entity)
1335 Prev_Entity := Empty;
1339 if Present (Prev_Entity) then
1340 Constant_Redeclaration (Id, N, T);
1342 Generate_Reference (Prev_Entity, Id, 'c');
1344 -- If in main unit, set as referenced, so we do not complain about
1345 -- the full declaration being an unreferenced entity.
1347 if In_Extended_Main_Source_Unit (Id) then
1348 Set_Referenced (Id);
1351 if Error_Posted (N) then
1352 -- Type mismatch or illegal redeclaration, Do not analyze
1353 -- expression to avoid cascaded errors.
1355 T := Find_Type_Of_Object (Object_Definition (N), N);
1357 Set_Ekind (Id, E_Variable);
1361 -- In the normal case, enter identifier at the start to catch
1362 -- premature usage in the initialization expression.
1365 Generate_Definition (Id);
1368 T := Find_Type_Of_Object (Object_Definition (N), N);
1370 if Error_Posted (Id) then
1372 Set_Ekind (Id, E_Variable);
1377 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1379 -- If deferred constant, make sure context is appropriate. We detect
1380 -- a deferred constant as a constant declaration with no expression.
1382 if Constant_Present (N)
1385 if not Is_Package (Current_Scope)
1386 or else In_Private_Part (Current_Scope)
1389 ("invalid context for deferred constant declaration", N);
1390 Set_Constant_Present (N, False);
1392 -- In Ada 83, deferred constant must be of private type
1394 elsif not Is_Private_Type (T) then
1395 if Ada_83 and then Comes_From_Source (N) then
1397 ("(Ada 83) deferred constant must be private type", N);
1401 -- If not a deferred constant, then object declaration freezes its type
1404 Check_Fully_Declared (T, N);
1405 Freeze_Before (N, T);
1408 -- If the object was created by a constrained array definition, then
1409 -- set the link in both the anonymous base type and anonymous subtype
1410 -- that are built to represent the array type to point to the object.
1412 if Nkind (Object_Definition (Declaration_Node (Id))) =
1413 N_Constrained_Array_Definition
1415 Set_Related_Array_Object (T, Id);
1416 Set_Related_Array_Object (Base_Type (T), Id);
1419 -- Special checks for protected objects not at library level
1421 if Is_Protected_Type (T)
1422 and then not Is_Library_Level_Entity (Id)
1424 Check_Restriction (No_Local_Protected_Objects, Id);
1426 -- Protected objects with interrupt handlers must be at library level
1428 if Has_Interrupt_Handler (T) then
1430 ("interrupt object can only be declared at library level", Id);
1434 -- The actual subtype of the object is the nominal subtype, unless
1435 -- the nominal one is unconstrained and obtained from the expression.
1439 -- Process initialization expression if present and not in error
1441 if Present (E) and then E /= Error then
1444 if not Assignment_OK (N) then
1445 Check_Initialization (T, E);
1450 -- Check for library level object that will require implicit
1453 if Is_Array_Type (T)
1454 and then not Size_Known_At_Compile_Time (T)
1455 and then Is_Library_Level_Entity (Id)
1457 -- String literals are always allowed
1459 if T = Standard_String
1460 and then Nkind (E) = N_String_Literal
1464 -- Otherwise we do not allow this since it may cause an
1465 -- implicit heap allocation.
1469 (No_Implicit_Heap_Allocations, Object_Definition (N));
1473 -- Check incorrect use of dynamically tagged expressions. Note
1474 -- the use of Is_Tagged_Type (T) which seems redundant but is in
1475 -- fact important to avoid spurious errors due to expanded code
1476 -- for dispatching functions over an anonymous access type
1478 if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
1479 and then Is_Tagged_Type (T)
1480 and then not Is_Class_Wide_Type (T)
1482 Error_Msg_N ("dynamically tagged expression not allowed!", E);
1485 Apply_Scalar_Range_Check (E, T);
1486 Apply_Static_Length_Check (E, T);
1489 -- Abstract type is never permitted for a variable or constant.
1490 -- Note: we inhibit this check for objects that do not come from
1491 -- source because there is at least one case (the expansion of
1492 -- x'class'input where x is abstract) where we legitimately
1493 -- generate an abstract object.
1495 if Is_Abstract (T) and then Comes_From_Source (N) then
1496 Error_Msg_N ("type of object cannot be abstract",
1497 Object_Definition (N));
1498 if Is_CPP_Class (T) then
1499 Error_Msg_NE ("\} may need a cpp_constructor",
1500 Object_Definition (N), T);
1503 -- Case of unconstrained type
1505 elsif Is_Indefinite_Subtype (T) then
1507 -- Nothing to do in deferred constant case
1509 if Constant_Present (N) and then No (E) then
1512 -- Case of no initialization present
1515 if No_Initialization (N) then
1518 elsif Is_Class_Wide_Type (T) then
1520 ("initialization required in class-wide declaration ", N);
1524 ("unconstrained subtype not allowed (need initialization)",
1525 Object_Definition (N));
1528 -- Case of initialization present but in error. Set initial
1529 -- expression as absent (but do not make above complaints)
1531 elsif E = Error then
1532 Set_Expression (N, Empty);
1535 -- Case of initialization present
1538 -- Not allowed in Ada 83
1540 if not Constant_Present (N) then
1542 and then Comes_From_Source (Object_Definition (N))
1545 ("(Ada 83) unconstrained variable not allowed",
1546 Object_Definition (N));
1550 -- Now we constrain the variable from the initializing expression
1552 -- If the expression is an aggregate, it has been expanded into
1553 -- individual assignments. Retrieve the actual type from the
1554 -- expanded construct.
1556 if Is_Array_Type (T)
1557 and then No_Initialization (N)
1558 and then Nkind (Original_Node (E)) = N_Aggregate
1563 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
1564 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
1567 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
1569 if Aliased_Present (N) then
1570 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1573 Freeze_Before (N, Act_T);
1574 Freeze_Before (N, T);
1577 elsif Is_Array_Type (T)
1578 and then No_Initialization (N)
1579 and then Nkind (Original_Node (E)) = N_Aggregate
1581 if not Is_Entity_Name (Object_Definition (N)) then
1584 if Aliased_Present (N) then
1585 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
1589 -- When the given object definition and the aggregate are specified
1590 -- independently, and their lengths might differ do a length check.
1591 -- This cannot happen if the aggregate is of the form (others =>...)
1593 if not Is_Constrained (T) then
1596 elsif T = Etype (E) then
1599 elsif Nkind (E) = N_Aggregate
1600 and then Present (Component_Associations (E))
1601 and then Present (Choices (First (Component_Associations (E))))
1602 and then Nkind (First
1603 (Choices (First (Component_Associations (E))))) = N_Others_Choice
1608 Apply_Length_Check (E, T);
1611 elsif (Is_Limited_Record (T)
1612 or else Is_Concurrent_Type (T))
1613 and then not Is_Constrained (T)
1614 and then Has_Discriminants (T)
1616 Act_T := Build_Default_Subtype;
1617 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
1619 elsif not Is_Constrained (T)
1620 and then Has_Discriminants (T)
1621 and then Constant_Present (N)
1622 and then Nkind (E) = N_Function_Call
1624 -- The back-end has problems with constants of a discriminated type
1625 -- with defaults, if the initial value is a function call. We
1626 -- generate an intermediate temporary for the result of the call.
1627 -- It is unclear why this should make it acceptable to gcc. ???
1629 Remove_Side_Effects (E);
1632 if T = Standard_Wide_Character
1633 or else Root_Type (T) = Standard_Wide_String
1635 Check_Restriction (No_Wide_Characters, Object_Definition (N));
1638 -- Now establish the proper kind and type of the object
1640 if Constant_Present (N) then
1641 Set_Ekind (Id, E_Constant);
1642 Set_Not_Source_Assigned (Id, True);
1643 Set_Is_True_Constant (Id, True);
1646 Set_Ekind (Id, E_Variable);
1648 -- A variable is set as shared passive if it appears in a shared
1649 -- passive package, and is at the outer level. This is not done
1650 -- for entities generated during expansion, because those are
1651 -- always manipulated locally.
1653 if Is_Shared_Passive (Current_Scope)
1654 and then Is_Library_Level_Entity (Id)
1655 and then Comes_From_Source (Id)
1657 Set_Is_Shared_Passive (Id);
1658 Check_Shared_Var (Id, T, N);
1661 -- If an initializing expression is present, then the variable
1662 -- is potentially a true constant if no further assignments are
1663 -- present. The code generator can use this for optimization.
1664 -- The flag will be reset if there are any assignments. We only
1665 -- set this flag for non library level entities, since for any
1666 -- library level entities, assignments could exist in other units.
1669 if not Is_Library_Level_Entity (Id) then
1671 -- For now we omit this, because it seems to cause some
1672 -- problems. In particular, if you uncomment this out, then
1673 -- test case 4427-002 will fail for unclear reasons ???
1676 Set_Is_True_Constant (Id);
1680 -- Case of no initializing expression present. If the type is not
1681 -- fully initialized, then we set Not_Source_Assigned, since this
1682 -- is a case of a potentially uninitialized object. Note that we
1683 -- do not consider access variables to be fully initialized for
1684 -- this purpose, since it still seems dubious if someone declares
1685 -- an access variable and never assigns to it.
1688 if Is_Access_Type (T)
1689 or else not Is_Fully_Initialized_Type (T)
1691 Set_Not_Source_Assigned (Id);
1696 Init_Alignment (Id);
1699 if Aliased_Present (N) then
1700 Set_Is_Aliased (Id);
1703 and then Is_Record_Type (T)
1704 and then not Is_Constrained (T)
1705 and then Has_Discriminants (T)
1707 Set_Actual_Subtype (Id, Build_Default_Subtype);
1711 Set_Etype (Id, Act_T);
1713 if Has_Controlled_Component (Etype (Id))
1714 or else Is_Controlled (Etype (Id))
1716 if not Is_Library_Level_Entity (Id) then
1717 Check_Restriction (No_Nested_Finalization, N);
1720 Validate_Controlled_Object (Id);
1723 -- Generate a warning when an initialization causes an obvious
1724 -- ABE violation. If the init expression is a simple aggregate
1725 -- there shouldn't be any initialize/adjust call generated. This
1726 -- will be true as soon as aggregates are built in place when
1727 -- possible. ??? at the moment we do not generate warnings for
1728 -- temporaries created for those aggregates although a
1729 -- Program_Error might be generated if compiled with -gnato
1731 if Is_Controlled (Etype (Id))
1732 and then Comes_From_Source (Id)
1735 BT : constant Entity_Id := Base_Type (Etype (Id));
1736 Implicit_Call : Entity_Id;
1738 function Is_Aggr (N : Node_Id) return Boolean;
1739 -- Check that N is an aggregate
1741 function Is_Aggr (N : Node_Id) return Boolean is
1743 case Nkind (Original_Node (N)) is
1744 when N_Aggregate | N_Extension_Aggregate =>
1747 when N_Qualified_Expression |
1749 N_Unchecked_Type_Conversion =>
1750 return Is_Aggr (Expression (Original_Node (N)));
1758 -- If no underlying type, we already are in an error situation
1759 -- don't try to add a warning since we do not have access
1762 if No (Underlying_Type (BT)) then
1763 Implicit_Call := Empty;
1765 -- A generic type does not have usable primitive operators.
1766 -- Initialization calls are built for instances.
1768 elsif Is_Generic_Type (BT) then
1769 Implicit_Call := Empty;
1771 -- if the init expression is not an aggregate, an adjust
1772 -- call will be generated
1774 elsif Present (E) and then not Is_Aggr (E) then
1775 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
1777 -- if no init expression and we are not in the deferred
1778 -- constant case, an Initialize call will be generated
1780 elsif No (E) and then not Constant_Present (N) then
1781 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
1784 Implicit_Call := Empty;
1790 if Has_Task (Etype (Id)) then
1791 if not Is_Library_Level_Entity (Id) then
1792 Check_Restriction (No_Task_Hierarchy, N);
1793 Check_Potentially_Blocking_Operation (N);
1797 -- Some simple constant-propagation: if the expression is a constant
1798 -- string initialized with a literal, share the literal. This avoids
1802 and then Is_Entity_Name (E)
1803 and then Ekind (Entity (E)) = E_Constant
1804 and then Base_Type (Etype (E)) = Standard_String
1807 Val : constant Node_Id := Constant_Value (Entity (E));
1811 and then Nkind (Val) = N_String_Literal
1813 Rewrite (E, New_Copy (Val));
1818 -- Another optimization: if the nominal subtype is unconstrained and
1819 -- the expression is a function call that returns and unconstrained
1820 -- type, rewrite the declararation as a renaming of the result of the
1821 -- call. The exceptions below are cases where the copy is expected,
1822 -- either by the back end (Aliased case) or by the semantics, as for
1823 -- initializing controlled types or copying tags for classwide types.
1826 and then Nkind (E) = N_Explicit_Dereference
1827 and then Nkind (Original_Node (E)) = N_Function_Call
1828 and then not Is_Library_Level_Entity (Id)
1829 and then not Is_Constrained (T)
1830 and then not Is_Aliased (Id)
1831 and then not Is_Class_Wide_Type (T)
1832 and then not Is_Controlled (T)
1833 and then not Has_Controlled_Component (Base_Type (T))
1834 and then Expander_Active
1837 Make_Object_Renaming_Declaration (Loc,
1838 Defining_Identifier => Id,
1839 Subtype_Mark => New_Occurrence_Of
1840 (Base_Type (Etype (Id)), Loc),
1843 Set_Renamed_Object (Id, E);
1846 if Present (Prev_Entity)
1847 and then Is_Frozen (Prev_Entity)
1848 and then not Error_Posted (Id)
1850 Error_Msg_N ("full constant declaration appears too late", N);
1853 Check_Eliminated (Id);
1854 end Analyze_Object_Declaration;
1856 ---------------------------
1857 -- Analyze_Others_Choice --
1858 ---------------------------
1860 -- Nothing to do for the others choice node itself, the semantic analysis
1861 -- of the others choice will occur as part of the processing of the parent
1863 procedure Analyze_Others_Choice (N : Node_Id) is
1866 end Analyze_Others_Choice;
1868 -------------------------------------------
1869 -- Analyze_Private_Extension_Declaration --
1870 -------------------------------------------
1872 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
1873 T : Entity_Id := Defining_Identifier (N);
1874 Indic : constant Node_Id := Subtype_Indication (N);
1875 Parent_Type : Entity_Id;
1876 Parent_Base : Entity_Id;
1879 Generate_Definition (T);
1882 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
1883 Parent_Base := Base_Type (Parent_Type);
1885 if Parent_Type = Any_Type
1886 or else Etype (Parent_Type) = Any_Type
1888 Set_Ekind (T, Ekind (Parent_Type));
1889 Set_Etype (T, Any_Type);
1892 elsif not Is_Tagged_Type (Parent_Type) then
1894 ("parent of type extension must be a tagged type ", Indic);
1897 elsif Ekind (Parent_Type) = E_Void
1898 or else Ekind (Parent_Type) = E_Incomplete_Type
1900 Error_Msg_N ("premature derivation of incomplete type", Indic);
1904 -- Perhaps the parent type should be changed to the class-wide type's
1905 -- specific type in this case to prevent cascading errors ???
1907 if Is_Class_Wide_Type (Parent_Type) then
1909 ("parent of type extension must not be a class-wide type", Indic);
1913 if (not Is_Package (Current_Scope)
1914 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
1915 or else In_Private_Part (Current_Scope)
1918 Error_Msg_N ("invalid context for private extension", N);
1921 -- Set common attributes
1923 Set_Is_Pure (T, Is_Pure (Current_Scope));
1924 Set_Scope (T, Current_Scope);
1925 Set_Ekind (T, E_Record_Type_With_Private);
1926 Init_Size_Align (T);
1928 Set_Etype (T, Parent_Base);
1929 Set_Has_Task (T, Has_Task (Parent_Base));
1931 Set_Convention (T, Convention (Parent_Type));
1932 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
1933 Set_Is_First_Subtype (T);
1934 Make_Class_Wide_Type (T);
1936 Build_Derived_Record_Type (N, Parent_Type, T);
1937 end Analyze_Private_Extension_Declaration;
1939 ---------------------------------
1940 -- Analyze_Subtype_Declaration --
1941 ---------------------------------
1943 procedure Analyze_Subtype_Declaration (N : Node_Id) is
1944 Id : constant Entity_Id := Defining_Identifier (N);
1946 R_Checks : Check_Result;
1949 Generate_Definition (Id);
1950 Set_Is_Pure (Id, Is_Pure (Current_Scope));
1951 Init_Size_Align (Id);
1953 -- The following guard condition on Enter_Name is to handle cases
1954 -- where the defining identifier has already been entered into the
1955 -- scope but the declaration as a whole needs to be analyzed.
1957 -- This case in particular happens for derived enumeration types.
1958 -- The derived enumeration type is processed as an inserted enumeration
1959 -- type declaration followed by a rewritten subtype declaration. The
1960 -- defining identifier, however, is entered into the name scope very
1961 -- early in the processing of the original type declaration and
1962 -- therefore needs to be avoided here, when the created subtype
1963 -- declaration is analyzed. (See Build_Derived_Types)
1965 -- This also happens when the full view of a private type is a
1966 -- derived type with constraints. In this case the entity has been
1967 -- introduced in the private declaration.
1969 if Present (Etype (Id))
1970 and then (Is_Private_Type (Etype (Id))
1971 or else Is_Task_Type (Etype (Id))
1972 or else Is_Rewrite_Substitution (N))
1980 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
1982 -- Inherit common attributes
1984 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
1985 Set_Is_Volatile (Id, Is_Volatile (T));
1986 Set_Is_Atomic (Id, Is_Atomic (T));
1988 -- In the case where there is no constraint given in the subtype
1989 -- indication, Process_Subtype just returns the Subtype_Mark,
1990 -- so its semantic attributes must be established here.
1992 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
1993 Set_Etype (Id, Base_Type (T));
1997 Set_Ekind (Id, E_Array_Subtype);
1999 -- Shouldn't we call Copy_Array_Subtype_Attributes here???
2001 Set_First_Index (Id, First_Index (T));
2002 Set_Is_Aliased (Id, Is_Aliased (T));
2003 Set_Is_Constrained (Id, Is_Constrained (T));
2005 when Decimal_Fixed_Point_Kind =>
2006 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
2007 Set_Digits_Value (Id, Digits_Value (T));
2008 Set_Delta_Value (Id, Delta_Value (T));
2009 Set_Scale_Value (Id, Scale_Value (T));
2010 Set_Small_Value (Id, Small_Value (T));
2011 Set_Scalar_Range (Id, Scalar_Range (T));
2012 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
2013 Set_Is_Constrained (Id, Is_Constrained (T));
2014 Set_RM_Size (Id, RM_Size (T));
2016 when Enumeration_Kind =>
2017 Set_Ekind (Id, E_Enumeration_Subtype);
2018 Set_First_Literal (Id, First_Literal (Base_Type (T)));
2019 Set_Scalar_Range (Id, Scalar_Range (T));
2020 Set_Is_Character_Type (Id, Is_Character_Type (T));
2021 Set_Is_Constrained (Id, Is_Constrained (T));
2022 Set_RM_Size (Id, RM_Size (T));
2024 when Ordinary_Fixed_Point_Kind =>
2025 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
2026 Set_Scalar_Range (Id, Scalar_Range (T));
2027 Set_Small_Value (Id, Small_Value (T));
2028 Set_Delta_Value (Id, Delta_Value (T));
2029 Set_Is_Constrained (Id, Is_Constrained (T));
2030 Set_RM_Size (Id, RM_Size (T));
2033 Set_Ekind (Id, E_Floating_Point_Subtype);
2034 Set_Scalar_Range (Id, Scalar_Range (T));
2035 Set_Digits_Value (Id, Digits_Value (T));
2036 Set_Is_Constrained (Id, Is_Constrained (T));
2038 when Signed_Integer_Kind =>
2039 Set_Ekind (Id, E_Signed_Integer_Subtype);
2040 Set_Scalar_Range (Id, Scalar_Range (T));
2041 Set_Is_Constrained (Id, Is_Constrained (T));
2042 Set_RM_Size (Id, RM_Size (T));
2044 when Modular_Integer_Kind =>
2045 Set_Ekind (Id, E_Modular_Integer_Subtype);
2046 Set_Scalar_Range (Id, Scalar_Range (T));
2047 Set_Is_Constrained (Id, Is_Constrained (T));
2048 Set_RM_Size (Id, RM_Size (T));
2050 when Class_Wide_Kind =>
2051 Set_Ekind (Id, E_Class_Wide_Subtype);
2052 Set_First_Entity (Id, First_Entity (T));
2053 Set_Last_Entity (Id, Last_Entity (T));
2054 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2055 Set_Cloned_Subtype (Id, T);
2056 Set_Is_Tagged_Type (Id, True);
2057 Set_Has_Unknown_Discriminants
2060 if Ekind (T) = E_Class_Wide_Subtype then
2061 Set_Equivalent_Type (Id, Equivalent_Type (T));
2064 when E_Record_Type | E_Record_Subtype =>
2065 Set_Ekind (Id, E_Record_Subtype);
2067 if Ekind (T) = E_Record_Subtype
2068 and then Present (Cloned_Subtype (T))
2070 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
2072 Set_Cloned_Subtype (Id, T);
2075 Set_First_Entity (Id, First_Entity (T));
2076 Set_Last_Entity (Id, Last_Entity (T));
2077 Set_Has_Discriminants (Id, Has_Discriminants (T));
2078 Set_Is_Constrained (Id, Is_Constrained (T));
2079 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2080 Set_Has_Unknown_Discriminants
2081 (Id, Has_Unknown_Discriminants (T));
2083 if Has_Discriminants (T) then
2084 Set_Discriminant_Constraint
2085 (Id, Discriminant_Constraint (T));
2086 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2088 elsif Has_Unknown_Discriminants (Id) then
2089 Set_Discriminant_Constraint (Id, No_Elist);
2092 if Is_Tagged_Type (T) then
2093 Set_Is_Tagged_Type (Id);
2094 Set_Is_Abstract (Id, Is_Abstract (T));
2095 Set_Primitive_Operations
2096 (Id, Primitive_Operations (T));
2097 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2100 when Private_Kind =>
2101 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2102 Set_Has_Discriminants (Id, Has_Discriminants (T));
2103 Set_Is_Constrained (Id, Is_Constrained (T));
2104 Set_First_Entity (Id, First_Entity (T));
2105 Set_Last_Entity (Id, Last_Entity (T));
2106 Set_Private_Dependents (Id, New_Elmt_List);
2107 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
2108 Set_Has_Unknown_Discriminants
2109 (Id, Has_Unknown_Discriminants (T));
2111 if Is_Tagged_Type (T) then
2112 Set_Is_Tagged_Type (Id);
2113 Set_Is_Abstract (Id, Is_Abstract (T));
2114 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
2117 -- In general the attributes of the subtype of a private
2118 -- type are the attributes of the partial view of parent.
2119 -- However, the full view may be a discriminated type,
2120 -- and the subtype must share the discriminant constraint
2121 -- to generate correct calls to initialization procedures.
2123 if Has_Discriminants (T) then
2124 Set_Discriminant_Constraint
2125 (Id, Discriminant_Constraint (T));
2126 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2128 elsif Present (Full_View (T))
2129 and then Has_Discriminants (Full_View (T))
2131 Set_Discriminant_Constraint
2132 (Id, Discriminant_Constraint (Full_View (T)));
2133 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2135 -- This would seem semantically correct, but apparently
2136 -- confuses the back-end (4412-009). To be explained ???
2138 -- Set_Has_Discriminants (Id);
2141 Prepare_Private_Subtype_Completion (Id, N);
2144 Set_Ekind (Id, E_Access_Subtype);
2145 Set_Is_Constrained (Id, Is_Constrained (T));
2146 Set_Is_Access_Constant
2147 (Id, Is_Access_Constant (T));
2148 Set_Directly_Designated_Type
2149 (Id, Designated_Type (T));
2151 -- A Pure library_item must not contain the declaration of a
2152 -- named access type, except within a subprogram, generic
2153 -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
2155 if Comes_From_Source (Id)
2156 and then In_Pure_Unit
2157 and then not In_Subprogram_Task_Protected_Unit
2160 ("named access types not allowed in pure unit", N);
2163 when Concurrent_Kind =>
2165 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
2166 Set_Corresponding_Record_Type (Id,
2167 Corresponding_Record_Type (T));
2168 Set_First_Entity (Id, First_Entity (T));
2169 Set_First_Private_Entity (Id, First_Private_Entity (T));
2170 Set_Has_Discriminants (Id, Has_Discriminants (T));
2171 Set_Is_Constrained (Id, Is_Constrained (T));
2172 Set_Last_Entity (Id, Last_Entity (T));
2174 if Has_Discriminants (T) then
2175 Set_Discriminant_Constraint (Id,
2176 Discriminant_Constraint (T));
2177 Set_Girder_Constraint_From_Discriminant_Constraint (Id);
2180 -- If the subtype name denotes an incomplete type
2181 -- an error was already reported by Process_Subtype.
2183 when E_Incomplete_Type =>
2184 Set_Etype (Id, Any_Type);
2187 raise Program_Error;
2191 if Etype (Id) = Any_Type then
2195 -- Some common processing on all types
2197 Set_Size_Info (Id, T);
2198 Set_First_Rep_Item (Id, First_Rep_Item (T));
2202 Set_Is_Immediately_Visible (Id, True);
2203 Set_Depends_On_Private (Id, Has_Private_Component (T));
2205 if Present (Generic_Parent_Type (N))
2208 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
2210 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
2211 /= N_Formal_Private_Type_Definition)
2213 if Is_Tagged_Type (Id) then
2214 if Is_Class_Wide_Type (Id) then
2215 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
2217 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
2220 elsif Scope (Etype (Id)) /= Standard_Standard then
2221 Derive_Subprograms (Generic_Parent_Type (N), Id);
2225 if Is_Private_Type (T)
2226 and then Present (Full_View (T))
2228 Conditional_Delay (Id, Full_View (T));
2230 -- The subtypes of components or subcomponents of protected types
2231 -- do not need freeze nodes, which would otherwise appear in the
2232 -- wrong scope (before the freeze node for the protected type). The
2233 -- proper subtypes are those of the subcomponents of the corresponding
2236 elsif Ekind (Scope (Id)) /= E_Protected_Type
2237 and then Present (Scope (Scope (Id))) -- error defense!
2238 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
2240 Conditional_Delay (Id, T);
2243 -- Check that constraint_error is raised for a scalar subtype
2244 -- indication when the lower or upper bound of a non-null range
2245 -- lies outside the range of the type mark.
2247 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
2248 if Is_Scalar_Type (Etype (Id))
2249 and then Scalar_Range (Id) /=
2250 Scalar_Range (Etype (Subtype_Mark
2251 (Subtype_Indication (N))))
2255 Etype (Subtype_Mark (Subtype_Indication (N))));
2257 elsif Is_Array_Type (Etype (Id))
2258 and then Present (First_Index (Id))
2260 -- This really should be a subprogram that finds the indications
2263 if ((Nkind (First_Index (Id)) = N_Identifier
2264 and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
2265 or else Nkind (First_Index (Id)) = N_Subtype_Indication)
2267 Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
2270 Target_Typ : Entity_Id :=
2273 (Etype (Subtype_Mark (Subtype_Indication (N)))));
2277 (Scalar_Range (Etype (First_Index (Id))),
2279 Etype (First_Index (Id)),
2280 Defining_Identifier (N));
2286 Sloc (Defining_Identifier (N)));
2292 Check_Eliminated (Id);
2293 end Analyze_Subtype_Declaration;
2295 --------------------------------
2296 -- Analyze_Subtype_Indication --
2297 --------------------------------
2299 procedure Analyze_Subtype_Indication (N : Node_Id) is
2300 T : constant Entity_Id := Subtype_Mark (N);
2301 R : constant Node_Id := Range_Expression (Constraint (N));
2306 Set_Etype (N, Etype (R));
2307 end Analyze_Subtype_Indication;
2309 ------------------------------
2310 -- Analyze_Type_Declaration --
2311 ------------------------------
2313 procedure Analyze_Type_Declaration (N : Node_Id) is
2314 Def : constant Node_Id := Type_Definition (N);
2315 Def_Id : constant Entity_Id := Defining_Identifier (N);
2320 Prev := Find_Type_Name (N);
2322 if Ekind (Prev) = E_Incomplete_Type then
2323 T := Full_View (Prev);
2328 Set_Is_Pure (T, Is_Pure (Current_Scope));
2330 -- We set the flag Is_First_Subtype here. It is needed to set the
2331 -- corresponding flag for the Implicit class-wide-type created
2332 -- during tagged types processing.
2334 Set_Is_First_Subtype (T, True);
2336 -- Only composite types other than array types are allowed to have
2341 -- For derived types, the rule will be checked once we've figured
2342 -- out the parent type.
2344 when N_Derived_Type_Definition =>
2347 -- For record types, discriminants are allowed.
2349 when N_Record_Definition =>
2353 if Present (Discriminant_Specifications (N)) then
2355 ("elementary or array type cannot have discriminants",
2357 (First (Discriminant_Specifications (N))));
2361 -- Elaborate the type definition according to kind, and generate
2362 -- susbsidiary (implicit) subtypes where needed. We skip this if
2363 -- it was already done (this happens during the reanalysis that
2364 -- follows a call to the high level optimizer).
2366 if not Analyzed (T) then
2371 when N_Access_To_Subprogram_Definition =>
2372 Access_Subprogram_Declaration (T, Def);
2374 -- If this is a remote access to subprogram, we must create
2375 -- the equivalent fat pointer type, and related subprograms.
2377 if Is_Remote_Types (Current_Scope)
2378 or else Is_Remote_Call_Interface (Current_Scope)
2380 Validate_Remote_Access_To_Subprogram_Type (N);
2381 Process_Remote_AST_Declaration (N);
2384 -- Validate categorization rule against access type declaration
2385 -- usually a violation in Pure unit, Shared_Passive unit.
2387 Validate_Access_Type_Declaration (T, N);
2389 when N_Access_To_Object_Definition =>
2390 Access_Type_Declaration (T, Def);
2392 -- Validate categorization rule against access type declaration
2393 -- usually a violation in Pure unit, Shared_Passive unit.
2395 Validate_Access_Type_Declaration (T, N);
2397 -- If we are in a Remote_Call_Interface package and define
2398 -- a RACW, Read and Write attribute must be added.
2400 if (Is_Remote_Call_Interface (Current_Scope)
2401 or else Is_Remote_Types (Current_Scope))
2402 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2404 Add_RACW_Features (Def_Id);
2407 when N_Array_Type_Definition =>
2408 Array_Type_Declaration (T, Def);
2410 when N_Derived_Type_Definition =>
2411 Derived_Type_Declaration (T, N, T /= Def_Id);
2413 when N_Enumeration_Type_Definition =>
2414 Enumeration_Type_Declaration (T, Def);
2416 when N_Floating_Point_Definition =>
2417 Floating_Point_Type_Declaration (T, Def);
2419 when N_Decimal_Fixed_Point_Definition =>
2420 Decimal_Fixed_Point_Type_Declaration (T, Def);
2422 when N_Ordinary_Fixed_Point_Definition =>
2423 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2425 when N_Signed_Integer_Type_Definition =>
2426 Signed_Integer_Type_Declaration (T, Def);
2428 when N_Modular_Type_Definition =>
2429 Modular_Type_Declaration (T, Def);
2431 when N_Record_Definition =>
2432 Record_Type_Declaration (T, N);
2435 raise Program_Error;
2440 if Etype (T) = Any_Type then
2444 -- Some common processing for all types
2446 Set_Depends_On_Private (T, Has_Private_Component (T));
2448 -- Both the declared entity, and its anonymous base type if one
2449 -- was created, need freeze nodes allocated.
2452 B : constant Entity_Id := Base_Type (T);
2455 -- In the case where the base type is different from the first
2456 -- subtype, we pre-allocate a freeze node, and set the proper
2457 -- link to the first subtype. Freeze_Entity will use this
2458 -- preallocated freeze node when it freezes the entity.
2461 Ensure_Freeze_Node (B);
2462 Set_First_Subtype_Link (Freeze_Node (B), T);
2465 if not From_With_Type (T) then
2466 Set_Has_Delayed_Freeze (T);
2470 -- Case of T is the full declaration of some private type which has
2471 -- been swapped in Defining_Identifier (N).
2473 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2474 Process_Full_View (N, T, Def_Id);
2476 -- Record the reference. The form of this is a little strange,
2477 -- since the full declaration has been swapped in. So the first
2478 -- parameter here represents the entity to which a reference is
2479 -- made which is the "real" entity, i.e. the one swapped in,
2480 -- and the second parameter provides the reference location.
2482 Generate_Reference (T, T, 'c');
2484 -- If in main unit, set as referenced, so we do not complain about
2485 -- the full declaration being an unreferenced entity.
2487 if In_Extended_Main_Source_Unit (Def_Id) then
2488 Set_Referenced (Def_Id);
2491 -- For completion of incomplete type, process incomplete dependents
2492 -- and always mark the full type as referenced (it is the incomplete
2493 -- type that we get for any real reference).
2495 elsif Ekind (Prev) = E_Incomplete_Type then
2496 Process_Incomplete_Dependents (N, T, Prev);
2497 Generate_Reference (Prev, Def_Id, 'c');
2499 -- If in main unit, set as referenced, so we do not complain about
2500 -- the full declaration being an unreferenced entity.
2502 if In_Extended_Main_Source_Unit (Def_Id) then
2503 Set_Referenced (Def_Id);
2506 -- If not private type or incomplete type completion, this is a real
2507 -- definition of a new entity, so record it.
2510 Generate_Definition (Def_Id);
2513 Check_Eliminated (Def_Id);
2514 end Analyze_Type_Declaration;
2516 --------------------------
2517 -- Analyze_Variant_Part --
2518 --------------------------
2520 procedure Analyze_Variant_Part (N : Node_Id) is
2522 procedure Non_Static_Choice_Error (Choice : Node_Id);
2523 -- Error routine invoked by the generic instantiation below when
2524 -- the variant part has a non static choice.
2526 procedure Process_Declarations (Variant : Node_Id);
2527 -- Analyzes all the declarations associated with a Variant.
2528 -- Needed by the generic instantiation below.
2530 package Variant_Choices_Processing is new
2531 Generic_Choices_Processing
2532 (Get_Alternatives => Variants,
2533 Get_Choices => Discrete_Choices,
2534 Process_Empty_Choice => No_OP,
2535 Process_Non_Static_Choice => Non_Static_Choice_Error,
2536 Process_Associated_Node => Process_Declarations);
2537 use Variant_Choices_Processing;
2538 -- Instantiation of the generic choice processing package.
2540 -----------------------------
2541 -- Non_Static_Choice_Error --
2542 -----------------------------
2544 procedure Non_Static_Choice_Error (Choice : Node_Id) is
2546 Error_Msg_N ("choice given in variant part is not static", Choice);
2547 end Non_Static_Choice_Error;
2549 --------------------------
2550 -- Process_Declarations --
2551 --------------------------
2553 procedure Process_Declarations (Variant : Node_Id) is
2555 if not Null_Present (Component_List (Variant)) then
2556 Analyze_Declarations (Component_Items (Component_List (Variant)));
2558 if Present (Variant_Part (Component_List (Variant))) then
2559 Analyze (Variant_Part (Component_List (Variant)));
2562 end Process_Declarations;
2564 -- Variables local to Analyze_Case_Statement.
2566 Others_Choice : Node_Id;
2568 Discr_Name : Node_Id;
2569 Discr_Type : Entity_Id;
2571 Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
2573 Dont_Care : Boolean;
2574 Others_Present : Boolean := False;
2576 -- Start of processing for Analyze_Variant_Part
2579 Discr_Name := Name (N);
2580 Analyze (Discr_Name);
2582 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
2583 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
2586 Discr_Type := Etype (Entity (Discr_Name));
2588 -- Call the instantiated Analyze_Choices which does the rest of the work
2591 (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
2593 if Others_Present then
2594 -- Fill in Others_Discrete_Choices field of the OTHERS choice
2596 Others_Choice := First (Discrete_Choices (Last (Variants (N))));
2597 Expand_Others_Choice
2598 (Case_Table (1 .. Last_Choice), Others_Choice, Discr_Type);
2601 end Analyze_Variant_Part;
2603 ----------------------------
2604 -- Array_Type_Declaration --
2605 ----------------------------
2607 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
2608 Component_Def : constant Node_Id := Subtype_Indication (Def);
2609 Element_Type : Entity_Id;
2610 Implicit_Base : Entity_Id;
2612 Related_Id : Entity_Id := Empty;
2614 P : constant Node_Id := Parent (Def);
2618 if Nkind (Def) = N_Constrained_Array_Definition then
2620 Index := First (Discrete_Subtype_Definitions (Def));
2622 -- Find proper names for the implicit types which may be public.
2623 -- in case of anonymous arrays we use the name of the first object
2624 -- of that type as prefix.
2627 Related_Id := Defining_Identifier (P);
2633 Index := First (Subtype_Marks (Def));
2638 while Present (Index) loop
2640 Make_Index (Index, P, Related_Id, Nb_Index);
2642 Nb_Index := Nb_Index + 1;
2645 Element_Type := Process_Subtype (Component_Def, P, Related_Id, 'C');
2647 -- Constrained array case
2650 T := Create_Itype (E_Void, P, Related_Id, 'T');
2653 if Nkind (Def) = N_Constrained_Array_Definition then
2655 -- Establish Implicit_Base as unconstrained base type
2657 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
2659 Init_Size_Align (Implicit_Base);
2660 Set_Etype (Implicit_Base, Implicit_Base);
2661 Set_Scope (Implicit_Base, Current_Scope);
2662 Set_Has_Delayed_Freeze (Implicit_Base);
2664 -- The constrained array type is a subtype of the unconstrained one
2666 Set_Ekind (T, E_Array_Subtype);
2667 Init_Size_Align (T);
2668 Set_Etype (T, Implicit_Base);
2669 Set_Scope (T, Current_Scope);
2670 Set_Is_Constrained (T, True);
2671 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
2672 Set_Has_Delayed_Freeze (T);
2674 -- Complete setup of implicit base type
2676 Set_First_Index (Implicit_Base, First_Index (T));
2677 Set_Component_Type (Implicit_Base, Element_Type);
2678 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
2679 Set_Component_Size (Implicit_Base, Uint_0);
2680 Set_Has_Controlled_Component (Implicit_Base,
2681 Has_Controlled_Component (Element_Type)
2682 or else Is_Controlled (Element_Type));
2683 Set_Finalize_Storage_Only (Implicit_Base,
2684 Finalize_Storage_Only (Element_Type));
2686 -- Unconstrained array case
2689 Set_Ekind (T, E_Array_Type);
2690 Init_Size_Align (T);
2692 Set_Scope (T, Current_Scope);
2693 Set_Component_Size (T, Uint_0);
2694 Set_Is_Constrained (T, False);
2695 Set_First_Index (T, First (Subtype_Marks (Def)));
2696 Set_Has_Delayed_Freeze (T, True);
2697 Set_Has_Task (T, Has_Task (Element_Type));
2698 Set_Has_Controlled_Component (T,
2699 Has_Controlled_Component (Element_Type)
2700 or else Is_Controlled (Element_Type));
2701 Set_Finalize_Storage_Only (T,
2702 Finalize_Storage_Only (Element_Type));
2705 Set_Component_Type (T, Element_Type);
2707 if Aliased_Present (Def) then
2708 Set_Has_Aliased_Components (Etype (T));
2711 Priv := Private_Component (Element_Type);
2713 if Present (Priv) then
2714 -- Check for circular definitions.
2716 if Priv = Any_Type then
2717 Set_Component_Type (T, Any_Type);
2718 Set_Component_Type (Etype (T), Any_Type);
2720 -- There is a gap in the visiblity of operations on the composite
2721 -- type only if the component type is defined in a different scope.
2723 elsif Scope (Priv) = Current_Scope then
2726 elsif Is_Limited_Type (Priv) then
2727 Set_Is_Limited_Composite (Etype (T));
2728 Set_Is_Limited_Composite (T);
2730 Set_Is_Private_Composite (Etype (T));
2731 Set_Is_Private_Composite (T);
2735 -- Create a concatenation operator for the new type. Internal
2736 -- array types created for packed entities do not need such, they
2737 -- are compatible with the user-defined type.
2739 if Number_Dimensions (T) = 1
2740 and then not Is_Packed_Array_Type (T)
2742 New_Binary_Operator (Name_Op_Concat, T);
2745 -- In the case of an unconstrained array the parser has already
2746 -- verified that all the indices are unconstrained but we still
2747 -- need to make sure that the element type is constrained.
2749 if Is_Indefinite_Subtype (Element_Type) then
2751 ("unconstrained element type in array declaration ",
2754 elsif Is_Abstract (Element_Type) then
2755 Error_Msg_N ("The type of a component cannot be abstract ",
2759 end Array_Type_Declaration;
2761 -------------------------------
2762 -- Build_Derived_Access_Type --
2763 -------------------------------
2765 procedure Build_Derived_Access_Type
2767 Parent_Type : Entity_Id;
2768 Derived_Type : Entity_Id)
2770 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
2772 Desig_Type : Entity_Id;
2774 Discr_Con_Elist : Elist_Id;
2775 Discr_Con_El : Elmt_Id;
2780 -- Set the designated type so it is available in case this is
2781 -- an access to a self-referential type, e.g. a standard list
2782 -- type with a next pointer. Will be reset after subtype is built.
2784 Set_Directly_Designated_Type (Derived_Type,
2785 Designated_Type (Parent_Type));
2787 Subt := Process_Subtype (S, N);
2789 if Nkind (S) /= N_Subtype_Indication
2790 and then Subt /= Base_Type (Subt)
2792 Set_Ekind (Derived_Type, E_Access_Subtype);
2795 if Ekind (Derived_Type) = E_Access_Subtype then
2797 Pbase : constant Entity_Id := Base_Type (Parent_Type);
2798 Ibase : constant Entity_Id :=
2799 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
2800 Svg_Chars : constant Name_Id := Chars (Ibase);
2801 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
2804 Copy_Node (Pbase, Ibase);
2806 Set_Chars (Ibase, Svg_Chars);
2807 Set_Next_Entity (Ibase, Svg_Next_E);
2808 Set_Sloc (Ibase, Sloc (Derived_Type));
2809 Set_Scope (Ibase, Scope (Derived_Type));
2810 Set_Freeze_Node (Ibase, Empty);
2811 Set_Is_Frozen (Ibase, False);
2813 Set_Etype (Ibase, Pbase);
2814 Set_Etype (Derived_Type, Ibase);
2818 Set_Directly_Designated_Type
2819 (Derived_Type, Designated_Type (Subt));
2821 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
2822 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
2823 Set_Size_Info (Derived_Type, Parent_Type);
2824 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
2825 Set_Depends_On_Private (Derived_Type,
2826 Has_Private_Component (Derived_Type));
2827 Conditional_Delay (Derived_Type, Subt);
2829 -- Note: we do not copy the Storage_Size_Variable, since
2830 -- we always go to the root type for this information.
2832 -- Apply range checks to discriminants for derived record case
2833 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
2835 Desig_Type := Designated_Type (Derived_Type);
2836 if Is_Composite_Type (Desig_Type)
2837 and then (not Is_Array_Type (Desig_Type))
2838 and then Has_Discriminants (Desig_Type)
2839 and then Base_Type (Desig_Type) /= Desig_Type
2841 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
2842 Discr_Con_El := First_Elmt (Discr_Con_Elist);
2844 Discr := First_Discriminant (Base_Type (Desig_Type));
2845 while Present (Discr_Con_El) loop
2846 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
2847 Next_Elmt (Discr_Con_El);
2848 Next_Discriminant (Discr);
2851 end Build_Derived_Access_Type;
2853 ------------------------------
2854 -- Build_Derived_Array_Type --
2855 ------------------------------
2857 procedure Build_Derived_Array_Type
2859 Parent_Type : Entity_Id;
2860 Derived_Type : Entity_Id)
2862 Loc : constant Source_Ptr := Sloc (N);
2863 Tdef : constant Node_Id := Type_Definition (N);
2864 Indic : constant Node_Id := Subtype_Indication (Tdef);
2865 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
2866 Implicit_Base : Entity_Id;
2867 New_Indic : Node_Id;
2869 procedure Make_Implicit_Base;
2870 -- If the parent subtype is constrained, the derived type is a
2871 -- subtype of an implicit base type derived from the parent base.
2873 ------------------------
2874 -- Make_Implicit_Base --
2875 ------------------------
2877 procedure Make_Implicit_Base is
2880 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
2882 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
2883 Set_Etype (Implicit_Base, Parent_Base);
2885 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
2886 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
2888 Set_Has_Delayed_Freeze (Implicit_Base, True);
2889 end Make_Implicit_Base;
2891 -- Start of processing for Build_Derived_Array_Type
2894 if not Is_Constrained (Parent_Type) then
2895 if Nkind (Indic) /= N_Subtype_Indication then
2896 Set_Ekind (Derived_Type, E_Array_Type);
2898 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
2899 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
2901 Set_Has_Delayed_Freeze (Derived_Type, True);
2905 Set_Etype (Derived_Type, Implicit_Base);
2908 Make_Subtype_Declaration (Loc,
2909 Defining_Identifier => Derived_Type,
2910 Subtype_Indication =>
2911 Make_Subtype_Indication (Loc,
2912 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
2913 Constraint => Constraint (Indic)));
2915 Rewrite (N, New_Indic);
2920 if Nkind (Indic) /= N_Subtype_Indication then
2923 Set_Ekind (Derived_Type, Ekind (Parent_Type));
2924 Set_Etype (Derived_Type, Implicit_Base);
2925 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
2928 Error_Msg_N ("illegal constraint on constrained type", Indic);
2932 -- If the parent type is not a derived type itself, and is
2933 -- declared in a closed scope (e.g., a subprogram), then we
2934 -- need to explicitly introduce the new type's concatenation
2935 -- operator since Derive_Subprograms will not inherit the
2936 -- parent's operator.
2938 if Number_Dimensions (Parent_Type) = 1
2939 and then not Is_Limited_Type (Parent_Type)
2940 and then not Is_Derived_Type (Parent_Type)
2941 and then not Is_Package (Scope (Base_Type (Parent_Type)))
2943 New_Binary_Operator (Name_Op_Concat, Derived_Type);
2945 end Build_Derived_Array_Type;
2947 -----------------------------------
2948 -- Build_Derived_Concurrent_Type --
2949 -----------------------------------
2951 procedure Build_Derived_Concurrent_Type
2953 Parent_Type : Entity_Id;
2954 Derived_Type : Entity_Id)
2956 D_Constraint : Node_Id;
2957 Disc_Spec : Node_Id;
2958 Old_Disc : Entity_Id;
2959 New_Disc : Entity_Id;
2960 Constraint_Present : constant Boolean :=
2961 Nkind (Subtype_Indication (Type_Definition (N))) =
2962 N_Subtype_Indication;
2965 Set_Girder_Constraint (Derived_Type, No_Elist);
2967 if Is_Task_Type (Parent_Type) then
2968 Set_Storage_Size_Variable (Derived_Type,
2969 Storage_Size_Variable (Parent_Type));
2972 if Present (Discriminant_Specifications (N)) then
2973 New_Scope (Derived_Type);
2974 Check_Or_Process_Discriminants (N, Derived_Type);
2978 -- All attributes are inherited from parent. In particular,
2979 -- entries and the corresponding record type are the same.
2980 -- Discriminants may be renamed, and must be treated separately.
2982 Set_Has_Discriminants
2983 (Derived_Type, Has_Discriminants (Parent_Type));
2984 Set_Corresponding_Record_Type
2985 (Derived_Type, Corresponding_Record_Type
2988 if Constraint_Present then
2990 if not Has_Discriminants (Parent_Type) then
2991 Error_Msg_N ("untagged parent must have discriminants", N);
2993 elsif Present (Discriminant_Specifications (N)) then
2995 -- Verify that new discriminants are used to constrain
2998 Old_Disc := First_Discriminant (Parent_Type);
2999 New_Disc := First_Discriminant (Derived_Type);
3000 Disc_Spec := First (Discriminant_Specifications (N));
3002 First (Constraints (
3003 Constraint (Subtype_Indication (Type_Definition (N)))));
3005 while Present (Old_Disc) and then Present (Disc_Spec) loop
3007 if Nkind (Discriminant_Type (Disc_Spec)) /=
3010 Analyze (Discriminant_Type (Disc_Spec));
3011 if not Subtypes_Statically_Compatible (
3012 Etype (Discriminant_Type (Disc_Spec)),
3016 ("not statically compatible with parent discriminant",
3017 Discriminant_Type (Disc_Spec));
3021 if Nkind (D_Constraint) = N_Identifier
3022 and then Chars (D_Constraint) /=
3023 Chars (Defining_Identifier (Disc_Spec))
3025 Error_Msg_N ("new discriminants must constrain old ones",
3028 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
3031 Next_Discriminant (Old_Disc);
3032 Next_Discriminant (New_Disc);
3036 if Present (Old_Disc) or else Present (Disc_Spec) then
3037 Error_Msg_N ("discriminant mismatch in derivation", N);
3042 elsif Present (Discriminant_Specifications (N)) then
3044 ("missing discriminant constraint in untagged derivation",
3048 if Present (Discriminant_Specifications (N)) then
3050 Old_Disc := First_Discriminant (Parent_Type);
3052 while Present (Old_Disc) loop
3054 if No (Next_Entity (Old_Disc))
3055 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
3057 Set_Next_Entity (Last_Entity (Derived_Type),
3058 Next_Entity (Old_Disc));
3062 Next_Discriminant (Old_Disc);
3066 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
3069 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
3071 Set_Has_Completion (Derived_Type);
3072 end Build_Derived_Concurrent_Type;
3074 ------------------------------------
3075 -- Build_Derived_Enumeration_Type --
3076 ------------------------------------
3078 procedure Build_Derived_Enumeration_Type
3080 Parent_Type : Entity_Id;
3081 Derived_Type : Entity_Id)
3083 Loc : constant Source_Ptr := Sloc (N);
3084 Def : constant Node_Id := Type_Definition (N);
3085 Indic : constant Node_Id := Subtype_Indication (Def);
3086 Implicit_Base : Entity_Id;
3087 Literal : Entity_Id;
3088 New_Lit : Entity_Id;
3089 Literals_List : List_Id;
3090 Type_Decl : Node_Id;
3092 Rang_Expr : Node_Id;
3095 -- Since types Standard.Character and Standard.Wide_Character do
3096 -- not have explicit literals lists we need to process types derived
3097 -- from them specially. This is handled by Derived_Standard_Character.
3098 -- If the parent type is a generic type, there are no literals either,
3099 -- and we construct the same skeletal representation as for the generic
3102 if Root_Type (Parent_Type) = Standard_Character
3103 or else Root_Type (Parent_Type) = Standard_Wide_Character
3105 Derived_Standard_Character (N, Parent_Type, Derived_Type);
3107 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
3114 Make_Attribute_Reference (Loc,
3115 Attribute_Name => Name_First,
3116 Prefix => New_Reference_To (Derived_Type, Loc));
3117 Set_Etype (Lo, Derived_Type);
3120 Make_Attribute_Reference (Loc,
3121 Attribute_Name => Name_Last,
3122 Prefix => New_Reference_To (Derived_Type, Loc));
3123 Set_Etype (Hi, Derived_Type);
3125 Set_Scalar_Range (Derived_Type,
3132 -- If a constraint is present, analyze the bounds to catch
3133 -- premature usage of the derived literals.
3135 if Nkind (Indic) = N_Subtype_Indication
3136 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
3138 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
3139 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
3142 -- Introduce an implicit base type for the derived type even
3143 -- if there is no constraint attached to it, since this seems
3144 -- closer to the Ada semantics. Build a full type declaration
3145 -- tree for the derived type using the implicit base type as
3146 -- the defining identifier. The build a subtype declaration
3147 -- tree which applies the constraint (if any) have it replace
3148 -- the derived type declaration.
3150 Literal := First_Literal (Parent_Type);
3151 Literals_List := New_List;
3153 while Present (Literal)
3154 and then Ekind (Literal) = E_Enumeration_Literal
3156 -- Literals of the derived type have the same representation as
3157 -- those of the parent type, but this representation can be
3158 -- overridden by an explicit representation clause. Indicate
3159 -- that there is no explicit representation given yet. These
3160 -- derived literals are implicit operations of the new type,
3161 -- and can be overriden by explicit ones.
3163 if Nkind (Literal) = N_Defining_Character_Literal then
3165 Make_Defining_Character_Literal (Loc, Chars (Literal));
3167 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
3170 Set_Ekind (New_Lit, E_Enumeration_Literal);
3171 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
3172 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
3173 Set_Enumeration_Rep_Expr (New_Lit, Empty);
3174 Set_Alias (New_Lit, Literal);
3175 Set_Is_Known_Valid (New_Lit, True);
3177 Append (New_Lit, Literals_List);
3178 Next_Literal (Literal);
3182 Make_Defining_Identifier (Sloc (Derived_Type),
3183 New_External_Name (Chars (Derived_Type), 'B'));
3185 -- Indicate the proper nature of the derived type. This must
3186 -- be done before analysis of the literals, to recognize cases
3187 -- when a literal may be hidden by a previous explicit function
3188 -- definition (cf. c83031a).
3190 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
3191 Set_Etype (Derived_Type, Implicit_Base);
3194 Make_Full_Type_Declaration (Loc,
3195 Defining_Identifier => Implicit_Base,
3196 Discriminant_Specifications => No_List,
3198 Make_Enumeration_Type_Definition (Loc, Literals_List));
3200 Mark_Rewrite_Insertion (Type_Decl);
3201 Insert_Before (N, Type_Decl);
3202 Analyze (Type_Decl);
3204 -- After the implicit base is analyzed its Etype needs to be
3205 -- changed to reflect the fact that it is derived from the
3206 -- parent type which was ignored during analysis. We also set
3207 -- the size at this point.
3209 Set_Etype (Implicit_Base, Parent_Type);
3211 Set_Size_Info (Implicit_Base, Parent_Type);
3212 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
3213 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
3215 Set_Has_Non_Standard_Rep
3216 (Implicit_Base, Has_Non_Standard_Rep
3218 Set_Has_Delayed_Freeze (Implicit_Base);
3220 -- Process the subtype indication including a validation check
3221 -- on the constraint, if any. If a constraint is given, its bounds
3222 -- must be implicitly converted to the new type.
3224 if Nkind (Indic) = N_Subtype_Indication then
3227 R : constant Node_Id :=
3228 Range_Expression (Constraint (Indic));
3231 if Nkind (R) = N_Range then
3232 Hi := Build_Scalar_Bound
3233 (High_Bound (R), Parent_Type, Implicit_Base, Loc);
3234 Lo := Build_Scalar_Bound
3235 (Low_Bound (R), Parent_Type, Implicit_Base, Loc);
3238 -- Constraint is a Range attribute. Replace with the
3239 -- explicit mention of the bounds of the prefix, which
3240 -- must be a subtype.
3242 Analyze (Prefix (R));
3244 Convert_To (Implicit_Base,
3245 Make_Attribute_Reference (Loc,
3246 Attribute_Name => Name_Last,
3248 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3251 Convert_To (Implicit_Base,
3252 Make_Attribute_Reference (Loc,
3253 Attribute_Name => Name_First,
3255 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
3263 (Type_High_Bound (Parent_Type),
3264 Parent_Type, Implicit_Base, Loc);
3267 (Type_Low_Bound (Parent_Type),
3268 Parent_Type, Implicit_Base, Loc);
3276 -- If we constructed a default range for the case where no range
3277 -- was given, then the expressions in the range must not freeze
3278 -- since they do not correspond to expressions in the source.
3280 if Nkind (Indic) /= N_Subtype_Indication then
3281 Set_Must_Not_Freeze (Lo);
3282 Set_Must_Not_Freeze (Hi);
3283 Set_Must_Not_Freeze (Rang_Expr);
3287 Make_Subtype_Declaration (Loc,
3288 Defining_Identifier => Derived_Type,
3289 Subtype_Indication =>
3290 Make_Subtype_Indication (Loc,
3291 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
3293 Make_Range_Constraint (Loc,
3294 Range_Expression => Rang_Expr))));
3298 -- If pragma Discard_Names applies on the first subtype
3299 -- of the parent type, then it must be applied on this
3302 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
3303 Set_Discard_Names (Derived_Type);
3306 -- Apply a range check. Since this range expression doesn't
3307 -- have an Etype, we have to specifically pass the Source_Typ
3308 -- parameter. Is this right???
3310 if Nkind (Indic) = N_Subtype_Indication then
3311 Apply_Range_Check (Range_Expression (Constraint (Indic)),
3313 Source_Typ => Entity (Subtype_Mark (Indic)));
3317 end Build_Derived_Enumeration_Type;
3319 --------------------------------
3320 -- Build_Derived_Numeric_Type --
3321 --------------------------------
3323 procedure Build_Derived_Numeric_Type
3325 Parent_Type : Entity_Id;
3326 Derived_Type : Entity_Id)
3328 Loc : constant Source_Ptr := Sloc (N);
3329 Tdef : constant Node_Id := Type_Definition (N);
3330 Indic : constant Node_Id := Subtype_Indication (Tdef);
3331 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
3332 No_Constraint : constant Boolean := Nkind (Indic) /=
3333 N_Subtype_Indication;
3334 Implicit_Base : Entity_Id;
3341 -- Process the subtype indication including a validation check on
3342 -- the constraint if any.
3344 T := Process_Subtype (Indic, N);
3346 -- Introduce an implicit base type for the derived type even if
3347 -- there is no constraint attached to it, since this seems closer
3348 -- to the Ada semantics.
3351 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
3353 Set_Etype (Implicit_Base, Parent_Base);
3354 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
3355 Set_Size_Info (Implicit_Base, Parent_Base);
3356 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3357 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
3358 Set_Parent (Implicit_Base, Parent (Derived_Type));
3360 if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
3361 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
3364 Set_Has_Delayed_Freeze (Implicit_Base);
3366 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
3367 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
3369 Set_Scalar_Range (Implicit_Base,
3374 if Has_Infinities (Parent_Base) then
3375 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
3378 -- The Derived_Type, which is the entity of the declaration, is
3379 -- a subtype of the implicit base. Its Ekind is a subtype, even
3380 -- in the absence of an explicit constraint.
3382 Set_Etype (Derived_Type, Implicit_Base);
3384 -- If we did not have a constraint, then the Ekind is set from the
3385 -- parent type (otherwise Process_Subtype has set the bounds)
3387 if No_Constraint then
3388 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
3391 -- If we did not have a range constraint, then set the range
3392 -- from the parent type. Otherwise, the call to Process_Subtype
3393 -- has set the bounds.
3396 or else not Has_Range_Constraint (Indic)
3398 Set_Scalar_Range (Derived_Type,
3400 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
3401 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
3402 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3404 if Has_Infinities (Parent_Type) then
3405 Set_Includes_Infinities (Scalar_Range (Derived_Type));
3409 -- Set remaining type-specific fields, depending on numeric type
3411 if Is_Modular_Integer_Type (Parent_Type) then
3412 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
3414 Set_Non_Binary_Modulus
3415 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
3417 elsif Is_Floating_Point_Type (Parent_Type) then
3419 -- Digits of base type is always copied from the digits value of
3420 -- the parent base type, but the digits of the derived type will
3421 -- already have been set if there was a constraint present.
3423 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3424 Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
3426 if No_Constraint then
3427 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
3430 elsif Is_Fixed_Point_Type (Parent_Type) then
3432 -- Small of base type and derived type are always copied from
3433 -- the parent base type, since smalls never change. The delta
3434 -- of the base type is also copied from the parent base type.
3435 -- However the delta of the derived type will have been set
3436 -- already if a constraint was present.
3438 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
3439 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
3440 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
3442 if No_Constraint then
3443 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
3446 -- The scale and machine radix in the decimal case are always
3447 -- copied from the parent base type.
3449 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
3450 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
3451 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
3453 Set_Machine_Radix_10
3454 (Derived_Type, Machine_Radix_10 (Parent_Base));
3455 Set_Machine_Radix_10
3456 (Implicit_Base, Machine_Radix_10 (Parent_Base));
3458 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
3460 if No_Constraint then
3461 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
3464 -- the analysis of the subtype_indication sets the
3465 -- digits value of the derived type.
3472 -- The type of the bounds is that of the parent type, and they
3473 -- must be converted to the derived type.
3475 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
3477 -- The implicit_base should be frozen when the derived type is frozen,
3478 -- but note that it is used in the conversions of the bounds. For
3479 -- fixed types we delay the determination of the bounds until the proper
3480 -- freezing point. For other numeric types this is rejected by GCC, for
3481 -- reasons that are currently unclear (???), so we choose to freeze the
3482 -- implicit base now. In the case of integers and floating point types
3483 -- this is harmless because subsequent representation clauses cannot
3484 -- affect anything, but it is still baffling that we cannot use the
3485 -- same mechanism for all derived numeric types.
3487 if Is_Fixed_Point_Type (Parent_Type) then
3488 Conditional_Delay (Implicit_Base, Parent_Type);
3490 Freeze_Before (N, Implicit_Base);
3493 end Build_Derived_Numeric_Type;
3495 --------------------------------
3496 -- Build_Derived_Private_Type --
3497 --------------------------------
3499 procedure Build_Derived_Private_Type
3501 Parent_Type : Entity_Id;
3502 Derived_Type : Entity_Id;
3503 Is_Completion : Boolean;
3504 Derive_Subps : Boolean := True)
3506 Der_Base : Entity_Id;
3508 Full_Decl : Node_Id := Empty;
3509 Full_Der : Entity_Id;
3511 Last_Discr : Entity_Id;
3512 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
3513 Swapped : Boolean := False;
3515 procedure Copy_And_Build;
3516 -- Copy derived type declaration, replace parent with its full view,
3517 -- and analyze new declaration.
3519 procedure Copy_And_Build is
3523 if Ekind (Parent_Type) in Record_Kind
3524 or else (Ekind (Parent_Type) in Enumeration_Kind
3525 and then Root_Type (Parent_Type) /= Standard_Character
3526 and then Root_Type (Parent_Type) /= Standard_Wide_Character
3527 and then not Is_Generic_Type (Root_Type (Parent_Type)))
3529 Full_N := New_Copy_Tree (N);
3530 Insert_After (N, Full_N);
3531 Build_Derived_Type (
3532 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
3535 Build_Derived_Type (
3536 N, Parent_Type, Full_Der, True, Derive_Subps => False);
3540 -- Start of processing for Build_Derived_Private_Type
3543 if Is_Tagged_Type (Parent_Type) then
3544 Build_Derived_Record_Type
3545 (N, Parent_Type, Derived_Type, Derive_Subps);
3548 elsif Has_Discriminants (Parent_Type) then
3550 if Present (Full_View (Parent_Type)) then
3551 if not Is_Completion then
3553 -- Copy declaration for subsequent analysis.
3555 Full_Decl := New_Copy_Tree (N);
3556 Full_Der := New_Copy (Derived_Type);
3557 Insert_After (N, Full_Decl);
3560 -- If this is a completion, the full view being built is
3561 -- itself private. We build a subtype of the parent with
3562 -- the same constraints as this full view, to convey to the
3563 -- back end the constrained components and the size of this
3564 -- subtype. If the parent is constrained, its full view can
3565 -- serve as the underlying full view of the derived type.
3567 if No (Discriminant_Specifications (N)) then
3569 if Nkind (Subtype_Indication (Type_Definition (N)))
3570 = N_Subtype_Indication
3572 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
3574 elsif Is_Constrained (Full_View (Parent_Type)) then
3575 Set_Underlying_Full_View (Derived_Type,
3576 Full_View (Parent_Type));
3580 -- If there are new discriminants, the parent subtype is
3581 -- constrained by them, but it is not clear how to build
3582 -- the underlying_full_view in this case ???
3589 Build_Derived_Record_Type
3590 (N, Parent_Type, Derived_Type, Derive_Subps);
3592 if Present (Full_View (Parent_Type))
3593 and then not Is_Completion
3595 if not In_Open_Scopes (Par_Scope)
3596 or else not In_Same_Source_Unit (N, Parent_Type)
3598 -- Swap partial and full views temporarily
3600 Install_Private_Declarations (Par_Scope);
3601 Install_Visible_Declarations (Par_Scope);
3605 -- Subprograms have been derived on the private view,
3606 -- the completion does not derive them anew.
3608 Build_Derived_Record_Type
3609 (Full_Decl, Parent_Type, Full_Der, False);
3612 Uninstall_Declarations (Par_Scope);
3614 if In_Open_Scopes (Par_Scope) then
3615 Install_Visible_Declarations (Par_Scope);
3619 Der_Base := Base_Type (Derived_Type);
3620 Set_Full_View (Derived_Type, Full_Der);
3621 Set_Full_View (Der_Base, Base_Type (Full_Der));
3623 -- Copy the discriminant list from full view to
3624 -- the partial views (base type and its subtype).
3625 -- Gigi requires that the partial and full views
3626 -- have the same discriminants.
3627 -- ??? Note that since the partial view is pointing
3628 -- to discriminants in the full view, their scope
3629 -- will be that of the full view. This might
3630 -- cause some front end problems and need
3633 Discr := First_Discriminant (Base_Type (Full_Der));
3634 Set_First_Entity (Der_Base, Discr);
3637 Last_Discr := Discr;
3638 Next_Discriminant (Discr);
3639 exit when No (Discr);
3642 Set_Last_Entity (Der_Base, Last_Discr);
3644 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
3645 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
3648 -- If this is a completion, the derived type stays private
3649 -- and there is no need to create a further full view, except
3650 -- in the unusual case when the derivation is nested within a
3651 -- child unit, see below.
3656 elsif Present (Full_View (Parent_Type))
3657 and then Has_Discriminants (Full_View (Parent_Type))
3659 if Has_Unknown_Discriminants (Parent_Type)
3660 and then Nkind (Subtype_Indication (Type_Definition (N)))
3661 = N_Subtype_Indication
3664 ("cannot constrain type with unknown discriminants",
3665 Subtype_Indication (Type_Definition (N)));
3669 -- Inherit the discriminants of the full view, but
3670 -- keep the proper parent type.
3672 -- ??? this looks wrong, we are replacing (and thus,
3673 -- erasing) the partial view!
3675 -- In any case, the primitive operations are inherited from
3676 -- the parent type, not from the internal full view.
3678 Build_Derived_Record_Type
3679 (N, Full_View (Parent_Type), Derived_Type,
3680 Derive_Subps => False);
3681 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
3683 if Derive_Subps then
3684 Derive_Subprograms (Parent_Type, Derived_Type);
3689 -- Untagged type, No discriminants on either view.
3691 if Nkind (Subtype_Indication (Type_Definition (N)))
3692 = N_Subtype_Indication
3695 ("illegal constraint on type without discriminants", N);
3698 if Present (Discriminant_Specifications (N))
3699 and then Present (Full_View (Parent_Type))
3700 and then not Is_Tagged_Type (Full_View (Parent_Type))
3703 ("cannot add discriminants to untagged type", N);
3706 Set_Girder_Constraint (Derived_Type, No_Elist);
3707 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
3708 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
3709 Set_Has_Controlled_Component (Derived_Type,
3710 Has_Controlled_Component (Parent_Type));
3712 -- Direct controlled types do not inherit the Finalize_Storage_Only
3715 if not Is_Controlled (Parent_Type) then
3716 Set_Finalize_Storage_Only (Derived_Type,
3717 Finalize_Storage_Only (Parent_Type));
3720 -- Construct the implicit full view by deriving from full
3721 -- view of the parent type. In order to get proper visiblity,
3722 -- we install the parent scope and its declarations.
3724 -- ??? if the parent is untagged private and its
3725 -- completion is tagged, this mechanism will not
3726 -- work because we cannot derive from the tagged
3727 -- full view unless we have an extension
3729 if Present (Full_View (Parent_Type))
3730 and then not Is_Tagged_Type (Full_View (Parent_Type))
3731 and then not Is_Completion
3733 Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
3734 Chars (Derived_Type));
3735 Set_Is_Itype (Full_Der);
3736 Set_Has_Private_Declaration (Full_Der);
3737 Set_Has_Private_Declaration (Derived_Type);
3738 Set_Associated_Node_For_Itype (Full_Der, N);
3739 Set_Parent (Full_Der, Parent (Derived_Type));
3740 Set_Full_View (Derived_Type, Full_Der);
3742 if not In_Open_Scopes (Par_Scope) then
3743 Install_Private_Declarations (Par_Scope);
3744 Install_Visible_Declarations (Par_Scope);
3746 Uninstall_Declarations (Par_Scope);
3748 -- If parent scope is open and in another unit, and
3749 -- parent has a completion, then the derivation is taking
3750 -- place in the visible part of a child unit. In that
3751 -- case retrieve the full view of the parent momentarily.
3753 elsif not In_Same_Source_Unit (N, Parent_Type) then
3754 Full_P := Full_View (Parent_Type);
3755 Exchange_Declarations (Parent_Type);
3757 Exchange_Declarations (Full_P);
3759 -- Otherwise it is a local derivation.
3765 Set_Scope (Full_Der, Current_Scope);
3766 Set_Is_First_Subtype (Full_Der,
3767 Is_First_Subtype (Derived_Type));
3768 Set_Has_Size_Clause (Full_Der, False);
3769 Set_Has_Alignment_Clause (Full_Der, False);
3770 Set_Next_Entity (Full_Der, Empty);
3771 Set_Has_Delayed_Freeze (Full_Der);
3772 Set_Is_Frozen (Full_Der, False);
3773 Set_Freeze_Node (Full_Der, Empty);
3774 Set_Depends_On_Private (Full_Der,
3775 Has_Private_Component (Full_Der));
3779 Set_Has_Unknown_Discriminants (Derived_Type,
3780 Has_Unknown_Discriminants (Parent_Type));
3782 if Is_Private_Type (Derived_Type) then
3783 Set_Private_Dependents (Derived_Type, New_Elmt_List);
3786 if Is_Private_Type (Parent_Type)
3787 and then Base_Type (Parent_Type) = Parent_Type
3788 and then In_Open_Scopes (Scope (Parent_Type))
3790 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
3792 if Is_Child_Unit (Scope (Current_Scope))
3793 and then Is_Completion
3794 and then In_Private_Part (Current_Scope)
3796 -- This is the unusual case where a type completed by a private
3797 -- derivation occurs within a package nested in a child unit,
3798 -- and the parent is declared in an ancestor. In this case, the
3799 -- full view of the parent type will become visible in the body
3800 -- of the enclosing child, and only then will the current type
3801 -- be possibly non-private. We build a underlying full view that
3802 -- will be installed when the enclosing child body is compiled.
3805 IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
3809 Make_Defining_Identifier (Sloc (Derived_Type),
3810 Chars (Derived_Type));
3811 Set_Is_Itype (Full_Der);
3812 Set_Itype (IR, Full_Der);
3813 Insert_After (N, IR);
3815 -- The full view will be used to swap entities on entry/exit
3816 -- to the body, and must appear in the entity list for the
3819 Append_Entity (Full_Der, Scope (Derived_Type));
3820 Set_Has_Private_Declaration (Full_Der);
3821 Set_Has_Private_Declaration (Derived_Type);
3822 Set_Associated_Node_For_Itype (Full_Der, N);
3823 Set_Parent (Full_Der, Parent (Derived_Type));
3824 Full_P := Full_View (Parent_Type);
3825 Exchange_Declarations (Parent_Type);
3827 Exchange_Declarations (Full_P);
3828 Set_Underlying_Full_View (Derived_Type, Full_Der);
3832 end Build_Derived_Private_Type;
3834 -------------------------------
3835 -- Build_Derived_Record_Type --
3836 -------------------------------
3840 -- Ideally we would like to use the same model of type derivation for
3841 -- tagged and untagged record types. Unfortunately this is not quite
3842 -- possible because the semantics of representation clauses is different
3843 -- for tagged and untagged records under inheritance. Consider the
3846 -- type R (...) is [tagged] record ... end record;
3847 -- type T (...) is new R (...) [with ...];
3849 -- The representation clauses of T can specify a completely different
3850 -- record layout from R's. Hence a same component can be placed in two very
3851 -- different positions in objects of type T and R. If R and T are tagged
3852 -- types, representation clauses for T can only specify the layout of non
3853 -- inherited components, thus components that are common in R and T have
3854 -- the same position in objects of type R or T.
3856 -- This has two implications. The first is that the entire tree for R's
3857 -- declaration needs to be copied for T in the untagged case, so that
3858 -- T can be viewd as a record type of its own with its own derivation
3859 -- clauses. The second implication is the way we handle discriminants.
3860 -- Specifically, in the untagged case we need a way to communicate to Gigi
3861 -- what are the real discriminants in the record, while for the semantics
3862 -- we need to consider those introduced by the user to rename the
3863 -- discriminants in the parent type. This is handled by introducing the
3864 -- notion of girder discriminants. See below for more.
3866 -- Fortunately the way regular components are inherited can be handled in
3867 -- the same way in tagged and untagged types.
3869 -- To complicate things a bit more the private view of a private extension
3870 -- cannot be handled in the same way as the full view (for one thing the
3871 -- semantic rules are somewhat different). We will explain what differs
3874 -- 2. DISCRIMINANTS UNDER INHERITANCE.
3876 -- The semantic rules governing the discriminants of derived types are
3879 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
3880 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
3882 -- If parent type has discriminants, then the discriminants that are
3883 -- declared in the derived type are [3.4 (11)]:
3885 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
3888 -- o Otherwise, each discriminant of the parent type (implicitely
3889 -- declared in the same order with the same specifications). In this
3890 -- case, the discriminants are said to be "inherited", or if unknown in
3891 -- the parent are also unknown in the derived type.
3893 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
3895 -- o The parent subtype shall be constrained;
3897 -- o If the parent type is not a tagged type, then each discriminant of
3898 -- the derived type shall be used in the constraint defining a parent
3899 -- subtype [Implementation note: this ensures that the new discriminant
3900 -- can share storage with an existing discriminant.].
3902 -- For the derived type each discriminant of the parent type is either
3903 -- inherited, constrained to equal some new discriminant of the derived
3904 -- type, or constrained to the value of an expression.
3906 -- When inherited or constrained to equal some new discriminant, the
3907 -- parent discriminant and the discriminant of the derived type are said
3910 -- If a discriminant of the parent type is constrained to a specific value
3911 -- in the derived type definition, then the discriminant is said to be
3912 -- "specified" by that derived type definition.
3914 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES.
3916 -- We have spoken about girder discriminants in the point 1 (introduction)
3917 -- above. There are two sort of girder discriminants: implicit and
3918 -- explicit. As long as the derived type inherits the same discriminants as
3919 -- the root record type, girder discriminants are the same as regular
3920 -- discriminants, and are said to be implicit. However, if any discriminant
3921 -- in the root type was renamed in the derived type, then the derived
3922 -- type will contain explicit girder discriminants. Explicit girder
3923 -- discriminants are discriminants in addition to the semantically visible
3924 -- discriminants defined for the derived type. Girder discriminants are
3925 -- used by Gigi to figure out what are the physical discriminants in
3926 -- objects of the derived type (see precise definition in einfo.ads).
3927 -- As an example, consider the following:
3929 -- type R (D1, D2, D3 : Int) is record ... end record;
3930 -- type T1 is new R;
3931 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
3932 -- type T3 is new T2;
3933 -- type T4 (Y : Int) is new T3 (Y, 99);
3935 -- The following table summarizes the discriminants and girder
3936 -- discriminants in R and T1 through T4.
3938 -- Type Discrim Girder Discrim Comment
3939 -- R (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in R
3940 -- T1 (D1, D2, D3) (D1, D2, D3) Gider discrims are implicit in T1
3941 -- T2 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T2
3942 -- T3 (X1, X2) (D1, D2, D3) Gider discrims are EXPLICIT in T3
3943 -- T4 (Y) (D1, D2, D3) Gider discrims are EXPLICIT in T4
3945 -- Field Corresponding_Discriminant (abbreviated CD below) allows to find
3946 -- the corresponding discriminant in the parent type, while
3947 -- Original_Record_Component (abbreviated ORC below), the actual physical
3948 -- component that is renamed. Finally the field Is_Completely_Hidden
3949 -- (abbreaviated ICH below) is set for all explicit girder discriminants
3950 -- (see einfo.ads for more info). For the above example this gives:
3952 -- Discrim CD ORC ICH
3953 -- ^^^^^^^ ^^ ^^^ ^^^
3954 -- D1 in R empty itself no
3955 -- D2 in R empty itself no
3956 -- D3 in R empty itself no
3958 -- D1 in T1 D1 in R itself no
3959 -- D2 in T1 D2 in R itself no
3960 -- D3 in T1 D3 in R itself no
3962 -- X1 in T2 D3 in T1 D3 in T2 no
3963 -- X2 in T2 D1 in T1 D1 in T2 no
3964 -- D1 in T2 empty itself yes
3965 -- D2 in T2 empty itself yes
3966 -- D3 in T2 empty itself yes
3968 -- X1 in T3 X1 in T2 D3 in T3 no
3969 -- X2 in T3 X2 in T2 D1 in T3 no
3970 -- D1 in T3 empty itself yes
3971 -- D2 in T3 empty itself yes
3972 -- D3 in T3 empty itself yes
3974 -- Y in T4 X1 in T3 D3 in T3 no
3975 -- D1 in T3 empty itself yes
3976 -- D2 in T3 empty itself yes
3977 -- D3 in T3 empty itself yes
3979 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES.
3981 -- Type derivation for tagged types is fairly straightforward. if no
3982 -- discriminants are specified by the derived type, these are inherited
3983 -- from the parent. No explicit girder discriminants are ever necessary.
3984 -- The only manipulation that is done to the tree is that of adding a
3985 -- _parent field with parent type and constrained to the same constraint
3986 -- specified for the parent in the derived type definition. For instance:
3988 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
3989 -- type T1 is new R with null record;
3990 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
3992 -- are changed into :
3994 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
3995 -- _parent : R (D1, D2, D3);
3998 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
3999 -- _parent : T1 (X2, 88, X1);
4002 -- The discriminants actually present in R, T1 and T2 as well as their CD,
4003 -- ORC and ICH fields are:
4005 -- Discrim CD ORC ICH
4006 -- ^^^^^^^ ^^ ^^^ ^^^
4007 -- D1 in R empty itself no
4008 -- D2 in R empty itself no
4009 -- D3 in R empty itself no
4011 -- D1 in T1 D1 in R D1 in R no
4012 -- D2 in T1 D2 in R D2 in R no
4013 -- D3 in T1 D3 in R D3 in R no
4015 -- X1 in T2 D3 in T1 D3 in R no
4016 -- X2 in T2 D1 in T1 D1 in R no
4018 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS.
4020 -- Regardless of whether we dealing with a tagged or untagged type
4021 -- we will transform all derived type declarations of the form
4023 -- type T is new R (...) [with ...];
4025 -- subtype S is R (...);
4026 -- type T is new S [with ...];
4028 -- type BT is new R [with ...];
4029 -- subtype T is BT (...);
4031 -- That is, the base derived type is constrained only if it has no
4032 -- discriminants. The reason for doing this is that GNAT's semantic model
4033 -- assumes that a base type with discriminants is unconstrained.
4035 -- Note that, strictly speaking, the above transformation is not always
4036 -- correct. Consider for instance the following exercpt from ACVC b34011a:
4038 -- procedure B34011A is
4039 -- type REC (D : integer := 0) is record
4044 -- type T6 is new Rec;
4045 -- function F return T6;
4050 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
4053 -- The definition of Q6.U is illegal. However transforming Q6.U into
4055 -- type BaseU is new T6;
4056 -- subtype U is BaseU (Q6.F.I)
4058 -- turns U into a legal subtype, which is incorrect. To avoid this problem
4059 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
4060 -- the transformation described above.
4062 -- There is another instance where the above transformation is incorrect.
4066 -- type Base (D : Integer) is tagged null record;
4067 -- procedure P (X : Base);
4069 -- type Der is new Base (2) with null record;
4070 -- procedure P (X : Der);
4073 -- Then the above transformation turns this into
4075 -- type Der_Base is new Base with null record;
4076 -- -- procedure P (X : Base) is implicitely inherited here
4077 -- -- as procedure P (X : Der_Base).
4079 -- subtype Der is Der_Base (2);
4080 -- procedure P (X : Der);
4081 -- -- The overriding of P (X : Der_Base) is illegal since we
4082 -- -- have a parameter conformance problem.
4084 -- To get around this problem, after having semantically processed Der_Base
4085 -- and the rewritten subtype declaration for Der, we copy Der_Base field
4086 -- Discriminant_Constraint from Der so that when parameter conformance is
4087 -- checked when P is overridden, no sematic errors are flagged.
4089 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS.
4091 -- Regardless of the fact that we dealing with a tagged or untagged type
4092 -- we will transform all derived type declarations of the form
4094 -- type R (D1, .., Dn : ...) is [tagged] record ...;
4095 -- type T is new R [with ...];
4097 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
4099 -- The reason for such transformation is that it allows us to implement a
4100 -- very clean form of component inheritance as explained below.
4102 -- Note that this transformation is not achieved by direct tree rewriting
4103 -- and manipulation, but rather by redoing the semantic actions that the
4104 -- above transformation will entail. This is done directly in routine
4105 -- Inherit_Components.
4107 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE.
4109 -- In both tagged and untagged derived types, regular non discriminant
4110 -- components are inherited in the derived type from the parent type. In
4111 -- the absence of discriminants component, inheritance is straightforward
4112 -- as components can simply be copied from the parent.
4113 -- If the parent has discriminants, inheriting components constrained with
4114 -- these discriminants requires caution. Consider the following example:
4116 -- type R (D1, D2 : Positive) is [tagged] record
4117 -- S : String (D1 .. D2);
4120 -- type T1 is new R [with null record];
4121 -- type T2 (X : positive) is new R (1, X) [with null record];
4123 -- As explained in 6. above, T1 is rewritten as
4125 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
4127 -- which makes the treatment for T1 and T2 identical.
4129 -- What we want when inheriting S, is that references to D1 and D2 in R are
4130 -- replaced with references to their correct constraints, ie D1 and D2 in
4131 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
4132 -- with either discriminant references in the derived type or expressions.
4133 -- This replacement is acheived as follows: before inheriting R's
4134 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
4135 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
4136 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
4137 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
4138 -- by String (1 .. X).
4140 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS.
4142 -- We explain here the rules governing private type extensions relevant to
4143 -- type derivation. These rules are explained on the following example:
4145 -- type D [(...)] is new A [(...)] with private; <-- partial view
4146 -- type D [(...)] is new P [(...)] with null record; <-- full view
4148 -- Type A is called the ancestor subtype of the private extension.
4149 -- Type P is the parent type of the full view of the private extension. It
4150 -- must be A or a type derived from A.
4152 -- The rules concerning the discriminants of private type extensions are
4155 -- o If a private extension inherits known discriminants from the ancestor
4156 -- subtype, then the full view shall also inherit its discriminants from
4157 -- the ancestor subtype and the parent subtype of the full view shall be
4158 -- constrained if and only if the ancestor subtype is constrained.
4160 -- o If a partial view has unknown discriminants, then the full view may
4161 -- define a definite or an indefinite subtype, with or without
4164 -- o If a partial view has neither known nor unknown discriminants, then
4165 -- the full view shall define a definite subtype.
4167 -- o If the ancestor subtype of a private extension has constrained
4168 -- discrimiants, then the parent subtype of the full view shall impose a
4169 -- statically matching constraint on those discriminants.
4171 -- This means that only the following forms of private extensions are
4174 -- type D is new A with private; <-- partial view
4175 -- type D is new P with null record; <-- full view
4177 -- If A has no discriminants than P has no discriminants, otherwise P must
4178 -- inherit A's discriminants.
4180 -- type D is new A (...) with private; <-- partial view
4181 -- type D is new P (:::) with null record; <-- full view
4183 -- P must inherit A's discriminants and (...) and (:::) must statically
4186 -- subtype A is R (...);
4187 -- type D is new A with private; <-- partial view
4188 -- type D is new P with null record; <-- full view
4190 -- P must have inherited R's discriminants and must be derived from A or
4191 -- any of its subtypes.
4193 -- type D (..) is new A with private; <-- partial view
4194 -- type D (..) is new P [(:::)] with null record; <-- full view
4196 -- No specific constraints on P's discriminants or constraint (:::).
4197 -- Note that A can be unconstrained, but the parent subtype P must either
4198 -- be constrained or (:::) must be present.
4200 -- type D (..) is new A [(...)] with private; <-- partial view
4201 -- type D (..) is new P [(:::)] with null record; <-- full view
4203 -- P's constraints on A's discriminants must statically match those
4204 -- imposed by (...).
4206 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS.
4208 -- The full view of a private extension is handled exactly as described
4209 -- above. The model chose for the private view of a private extension
4210 -- is the same for what concerns discriminants (ie they receive the same
4211 -- treatment as in the tagged case). However, the private view of the
4212 -- private extension always inherits the components of the parent base,
4213 -- without replacing any discriminant reference. Strictly speacking this
4214 -- is incorrect. However, Gigi never uses this view to generate code so
4215 -- this is a purely semantic issue. In theory, a set of transformations
4216 -- similar to those given in 5. and 6. above could be applied to private
4217 -- views of private extensions to have the same model of component
4218 -- inheritance as for non private extensions. However, this is not done
4219 -- because it would further complicate private type processing.
4220 -- Semantically speaking, this leaves us in an uncomfortable
4221 -- situation. As an example consider:
4224 -- type R (D : integer) is tagged record
4225 -- S : String (1 .. D);
4227 -- procedure P (X : R);
4228 -- type T is new R (1) with private;
4230 -- type T is new R (1) with null record;
4233 -- This is transformed into:
4236 -- type R (D : integer) is tagged record
4237 -- S : String (1 .. D);
4239 -- procedure P (X : R);
4240 -- type T is new R (1) with private;
4242 -- type BaseT is new R with null record;
4243 -- subtype T is BaseT (1);
4246 -- (strictly speaking the above is incorrect Ada).
4248 -- From the semantic standpoint the private view of private extension T
4249 -- should be flagged as constrained since one can clearly have
4253 -- in a unit withing Pack. However, when deriving subprograms for the
4254 -- private view of private extension T, T must be seen as unconstrained
4255 -- since T has discriminants (this is a constraint of the current
4256 -- subprogram derivation model). Thus, when processing the private view of
4257 -- a private extension such as T, we first mark T as unconstrained, we
4258 -- process it, we perform program derivation and just before returning from
4259 -- Build_Derived_Record_Type we mark T as constrained.
4260 -- ??? Are there are other unconfortable cases that we will have to
4263 -- 10. RECORD_TYPE_WITH_PRIVATE complications.
4265 -- Types that are derived from a visible record type and have a private
4266 -- extension present other peculiarities. They behave mostly like private
4267 -- types, but if they have primitive operations defined, these will not
4268 -- have the proper signatures for further inheritance, because other
4269 -- primitive operations will use the implicit base that we define for
4270 -- private derivations below. This affect subprogram inheritance (see
4271 -- Derive_Subprograms for details). We also derive the implicit base from
4272 -- the base type of the full view, so that the implicit base is a record
4273 -- type and not another private type, This avoids infinite loops.
4275 procedure Build_Derived_Record_Type
4277 Parent_Type : Entity_Id;
4278 Derived_Type : Entity_Id;
4279 Derive_Subps : Boolean := True)
4281 Loc : constant Source_Ptr := Sloc (N);
4282 Parent_Base : Entity_Id;
4287 Discrim : Entity_Id;
4288 Last_Discrim : Entity_Id;
4290 Discs : Elist_Id := New_Elmt_List;
4291 -- An empty Discs list means that there were no constraints in the
4292 -- subtype indication or that there was an error processing it.
4294 Assoc_List : Elist_Id;
4295 New_Discrs : Elist_Id;
4297 New_Base : Entity_Id;
4299 New_Indic : Node_Id;
4301 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
4302 Discriminant_Specs : constant Boolean
4303 := Present (Discriminant_Specifications (N));
4304 Private_Extension : constant Boolean
4305 := (Nkind (N) = N_Private_Extension_Declaration);
4307 Constraint_Present : Boolean;
4308 Inherit_Discrims : Boolean := False;
4310 Save_Etype : Entity_Id;
4311 Save_Discr_Constr : Elist_Id;
4312 Save_Next_Entity : Entity_Id;
4315 if Ekind (Parent_Type) = E_Record_Type_With_Private
4316 and then Present (Full_View (Parent_Type))
4317 and then Has_Discriminants (Parent_Type)
4319 Parent_Base := Base_Type (Full_View (Parent_Type));
4321 Parent_Base := Base_Type (Parent_Type);
4324 -- Before we start the previously documented transformations, here is
4325 -- a little fix for size and alignment of tagged types. Normally when
4326 -- we derive type D from type P, we copy the size and alignment of P
4327 -- as the default for D, and in the absence of explicit representation
4328 -- clauses for D, the size and alignment are indeed the same as the
4331 -- But this is wrong for tagged types, since fields may be added,
4332 -- and the default size may need to be larger, and the default
4333 -- alignment may need to be larger.
4335 -- We therefore reset the size and alignment fields in the tagged
4336 -- case. Note that the size and alignment will in any case be at
4337 -- least as large as the parent type (since the derived type has
4338 -- a copy of the parent type in the _parent field)
4341 Init_Size_Align (Derived_Type);
4344 -- STEP 0a: figure out what kind of derived type declaration we have.
4346 if Private_Extension then
4348 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
4351 Type_Def := Type_Definition (N);
4353 -- Ekind (Parent_Base) in not necessarily E_Record_Type since
4354 -- Parent_Base can be a private type or private extension. However,
4355 -- for tagged types with an extension the newly added fields are
4356 -- visible and hence the Derived_Type is always an E_Record_Type.
4357 -- (except that the parent may have its own private fields).
4358 -- For untagged types we preserve the Ekind of the Parent_Base.
4360 if Present (Record_Extension_Part (Type_Def)) then
4361 Set_Ekind (Derived_Type, E_Record_Type);
4363 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4367 -- Indic can either be an N_Identifier if the subtype indication
4368 -- contains no constraint or an N_Subtype_Indication if the subtype
4369 -- indication has a constraint.
4371 Indic := Subtype_Indication (Type_Def);
4372 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
4374 if Constraint_Present then
4375 if not Has_Discriminants (Parent_Base) then
4377 ("invalid constraint: type has no discriminant",
4378 Constraint (Indic));
4380 Constraint_Present := False;
4381 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4383 elsif Is_Constrained (Parent_Type) then
4385 ("invalid constraint: parent type is already constrained",
4386 Constraint (Indic));
4388 Constraint_Present := False;
4389 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
4393 -- STEP 0b: If needed, apply transformation given in point 5. above.
4395 if not Private_Extension
4396 and then Has_Discriminants (Parent_Type)
4397 and then not Discriminant_Specs
4398 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
4400 -- First, we must analyze the constraint (see comment in point 5.).
4402 if Constraint_Present then
4403 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
4405 if Has_Discriminants (Derived_Type)
4406 and then Has_Private_Declaration (Derived_Type)
4407 and then Present (Discriminant_Constraint (Derived_Type))
4409 -- Verify that constraints of the full view conform to those
4410 -- given in partial view.
4416 C1 := First_Elmt (New_Discrs);
4417 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
4419 while Present (C1) and then Present (C2) loop
4421 Fully_Conformant_Expressions (Node (C1), Node (C2))
4424 "constraint not conformant to previous declaration",
4434 -- Insert and analyze the declaration for the unconstrained base type
4436 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
4439 Make_Full_Type_Declaration (Loc,
4440 Defining_Identifier => New_Base,
4442 Make_Derived_Type_Definition (Loc,
4443 Abstract_Present => Abstract_Present (Type_Def),
4444 Subtype_Indication =>
4445 New_Occurrence_Of (Parent_Base, Loc),
4446 Record_Extension_Part =>
4447 Relocate_Node (Record_Extension_Part (Type_Def))));
4449 Set_Parent (New_Decl, Parent (N));
4450 Mark_Rewrite_Insertion (New_Decl);
4451 Insert_Before (N, New_Decl);
4453 -- Note that this call passes False for the Derive_Subps
4454 -- parameter because subprogram derivation is deferred until
4455 -- after creating the subtype (see below).
4458 (New_Decl, Parent_Base, New_Base,
4459 Is_Completion => True, Derive_Subps => False);
4461 -- ??? This needs re-examination to determine whether the
4462 -- above call can simply be replaced by a call to Analyze.
4464 Set_Analyzed (New_Decl);
4466 -- Insert and analyze the declaration for the constrained subtype
4468 if Constraint_Present then
4470 Make_Subtype_Indication (Loc,
4471 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4472 Constraint => Relocate_Node (Constraint (Indic)));
4477 Constr_List : List_Id := New_List;
4481 C := First_Elmt (Discriminant_Constraint (Parent_Type));
4482 while Present (C) loop
4485 -- It is safe here to call New_Copy_Tree since
4486 -- Force_Evaluation was called on each constraint in
4487 -- Build_Discriminant_Constraints.
4489 Append (New_Copy_Tree (Expr), To => Constr_List);
4495 Make_Subtype_Indication (Loc,
4496 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
4498 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
4503 Make_Subtype_Declaration (Loc,
4504 Defining_Identifier => Derived_Type,
4505 Subtype_Indication => New_Indic));
4509 -- Derivation of subprograms must be delayed until the
4510 -- full subtype has been established to ensure proper
4511 -- overriding of subprograms inherited by full types.
4512 -- If the derivations occurred as part of the call to
4513 -- Build_Derived_Type above, then the check for type
4514 -- conformance would fail because earlier primitive
4515 -- subprograms could still refer to the full type prior
4516 -- the change to the new subtype and hence wouldn't
4517 -- match the new base type created here.
4519 Derive_Subprograms (Parent_Type, Derived_Type);
4521 -- For tagged types the Discriminant_Constraint of the new base itype
4522 -- is inherited from the first subtype so that no subtype conformance
4523 -- problem arise when the first subtype overrides primitive
4524 -- operations inherited by the implicit base type.
4527 Set_Discriminant_Constraint
4528 (New_Base, Discriminant_Constraint (Derived_Type));
4534 -- If we get here Derived_Type will have no discriminants or it will be
4535 -- a discriminated unconstrained base type.
4537 -- STEP 1a: perform preliminary actions/checks for derived tagged types
4540 -- The parent type is frozen for non-private extensions (RM 13.14(7))
4542 if not Private_Extension then
4543 Freeze_Before (N, Parent_Type);
4546 if Type_Access_Level (Derived_Type) /= Type_Access_Level (Parent_Type)
4547 and then not Is_Generic_Type (Derived_Type)
4549 if Is_Controlled (Parent_Type) then
4551 ("controlled type must be declared at the library level",
4555 ("type extension at deeper accessibility level than parent",
4561 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
4565 and then GB /= Enclosing_Generic_Body (Parent_Base)
4568 ("parent type must not be outside generic body",
4575 -- STEP 1b : preliminary cleanup of the full view of private types
4577 -- If the type is already marked as having discriminants, then it's the
4578 -- completion of a private type or private extension and we need to
4579 -- retain the discriminants from the partial view if the current
4580 -- declaration has Discriminant_Specifications so that we can verify
4581 -- conformance. However, we must remove any existing components that
4582 -- were inherited from the parent (and attached in Copy_Private_To_Full)
4583 -- because the full type inherits all appropriate components anyway, and
4584 -- we don't want the partial view's components interfering.
4586 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
4587 Discrim := First_Discriminant (Derived_Type);
4589 Last_Discrim := Discrim;
4590 Next_Discriminant (Discrim);
4591 exit when No (Discrim);
4594 Set_Last_Entity (Derived_Type, Last_Discrim);
4596 -- In all other cases wipe out the list of inherited components (even
4597 -- inherited discriminants), it will be properly rebuilt here.
4600 Set_First_Entity (Derived_Type, Empty);
4601 Set_Last_Entity (Derived_Type, Empty);
4604 -- STEP 1c: Initialize some flags for the Derived_Type
4606 -- The following flags must be initialized here so that
4607 -- Process_Discriminants can check that discriminants of tagged types
4608 -- do not have a default initial value and that access discriminants
4609 -- are only specified for limited records. For completeness, these
4610 -- flags are also initialized along with all the other flags below.
4612 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4613 Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (Parent_Type));
4615 -- STEP 2a: process discriminants of derived type if any.
4617 New_Scope (Derived_Type);
4619 if Discriminant_Specs then
4620 Set_Has_Unknown_Discriminants (Derived_Type, False);
4622 -- The following call initializes fields Has_Discriminants and
4623 -- Discriminant_Constraint, unless we are processing the completion
4624 -- of a private type declaration.
4626 Check_Or_Process_Discriminants (N, Derived_Type);
4628 -- For non-tagged types the constraint on the Parent_Type must be
4629 -- present and is used to rename the discriminants.
4631 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
4632 Error_Msg_N ("untagged parent must have discriminants", Indic);
4634 elsif not Is_Tagged and then not Constraint_Present then
4636 ("discriminant constraint needed for derived untagged records",
4639 -- Otherwise the parent subtype must be constrained unless we have a
4640 -- private extension.
4642 elsif not Constraint_Present
4643 and then not Private_Extension
4644 and then not Is_Constrained (Parent_Type)
4647 ("unconstrained type not allowed in this context", Indic);
4649 elsif Constraint_Present then
4650 -- The following call sets the field Corresponding_Discriminant
4651 -- for the discriminants in the Derived_Type.
4653 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
4655 -- For untagged types all new discriminants must rename
4656 -- discriminants in the parent. For private extensions new
4657 -- discriminants cannot rename old ones (implied by [7.3(13)]).
4659 Discrim := First_Discriminant (Derived_Type);
4661 while Present (Discrim) loop
4663 and then not Present (Corresponding_Discriminant (Discrim))
4666 ("new discriminants must constrain old ones", Discrim);
4668 elsif Private_Extension
4669 and then Present (Corresponding_Discriminant (Discrim))
4672 ("Only static constraints allowed for parent"
4673 & " discriminants in the partial view", Indic);
4678 -- If a new discriminant is used in the constraint,
4679 -- then its subtype must be statically compatible
4680 -- with the parent discriminant's subtype (3.7(15)).
4682 if Present (Corresponding_Discriminant (Discrim))
4684 not Subtypes_Statically_Compatible
4686 Etype (Corresponding_Discriminant (Discrim)))
4689 ("subtype must be compatible with parent discriminant",
4693 Next_Discriminant (Discrim);
4697 -- STEP 2b: No new discriminants, inherit discriminants if any
4700 if Private_Extension then
4701 Set_Has_Unknown_Discriminants
4702 (Derived_Type, Has_Unknown_Discriminants (Parent_Type)
4703 or else Unknown_Discriminants_Present (N));
4705 Set_Has_Unknown_Discriminants
4706 (Derived_Type, Has_Unknown_Discriminants (Parent_Type));
4709 if not Has_Unknown_Discriminants (Derived_Type)
4710 and then Has_Discriminants (Parent_Type)
4712 Inherit_Discrims := True;
4713 Set_Has_Discriminants
4714 (Derived_Type, True);
4715 Set_Discriminant_Constraint
4716 (Derived_Type, Discriminant_Constraint (Parent_Base));
4719 -- The following test is true for private types (remember
4720 -- transformation 5. is not applied to those) and in an error
4723 if Constraint_Present then
4724 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
4727 -- For now mark a new derived type as cosntrained only if it has no
4728 -- discriminants. At the end of Build_Derived_Record_Type we properly
4729 -- set this flag in the case of private extensions. See comments in
4730 -- point 9. just before body of Build_Derived_Record_Type.
4734 not (Inherit_Discrims
4735 or else Has_Unknown_Discriminants (Derived_Type)));
4738 -- STEP 3: initialize fields of derived type.
4740 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
4741 Set_Girder_Constraint (Derived_Type, No_Elist);
4743 -- Fields inherited from the Parent_Type
4746 (Derived_Type, Einfo.Discard_Names (Parent_Type));
4747 Set_Has_Specified_Layout
4748 (Derived_Type, Has_Specified_Layout (Parent_Type));
4749 Set_Is_Limited_Composite
4750 (Derived_Type, Is_Limited_Composite (Parent_Type));
4751 Set_Is_Limited_Record
4752 (Derived_Type, Is_Limited_Record (Parent_Type));
4753 Set_Is_Private_Composite
4754 (Derived_Type, Is_Private_Composite (Parent_Type));
4756 -- Fields inherited from the Parent_Base
4758 Set_Has_Controlled_Component
4759 (Derived_Type, Has_Controlled_Component (Parent_Base));
4760 Set_Has_Non_Standard_Rep
4761 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4762 Set_Has_Primitive_Operations
4763 (Derived_Type, Has_Primitive_Operations (Parent_Base));
4765 -- Direct controlled types do not inherit the Finalize_Storage_Only
4768 if not Is_Controlled (Parent_Type) then
4769 Set_Finalize_Storage_Only (Derived_Type,
4770 Finalize_Storage_Only (Parent_Type));
4773 -- Set fields for private derived types.
4775 if Is_Private_Type (Derived_Type) then
4776 Set_Depends_On_Private (Derived_Type, True);
4777 Set_Private_Dependents (Derived_Type, New_Elmt_List);
4779 -- Inherit fields from non private record types. If this is the
4780 -- completion of a derivation from a private type, the parent itself
4781 -- is private, and the attributes come from its full view, which must
4785 if Is_Private_Type (Parent_Base)
4786 and then not Is_Record_Type (Parent_Base)
4788 Set_Component_Alignment
4789 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
4791 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
4793 Set_Component_Alignment
4794 (Derived_Type, Component_Alignment (Parent_Base));
4797 (Derived_Type, C_Pass_By_Copy (Parent_Base));
4801 -- Set fields for tagged types.
4804 Set_Primitive_Operations (Derived_Type, New_Elmt_List);
4806 -- All tagged types defined in Ada.Finalization are controlled
4808 if Chars (Scope (Derived_Type)) = Name_Finalization
4809 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
4810 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
4812 Set_Is_Controlled (Derived_Type);
4814 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
4817 Make_Class_Wide_Type (Derived_Type);
4818 Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
4820 if Has_Discriminants (Derived_Type)
4821 and then Constraint_Present
4823 Set_Girder_Constraint
4824 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4828 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
4829 Set_Has_Non_Standard_Rep
4830 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
4833 -- STEP 4: Inherit components from the parent base and constrain them.
4834 -- Apply the second transformation described in point 6. above.
4836 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
4837 or else not Has_Discriminants (Parent_Type)
4838 or else not Is_Constrained (Parent_Type)
4842 Constrs := Discriminant_Constraint (Parent_Type);
4845 Assoc_List := Inherit_Components (N,
4846 Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
4848 -- STEP 5a: Copy the parent record declaration for untagged types
4850 if not Is_Tagged then
4852 -- Discriminant_Constraint (Derived_Type) has been properly
4853 -- constructed. Save it and temporarily set it to Empty because we do
4854 -- not want the call to New_Copy_Tree below to mess this list.
4856 if Has_Discriminants (Derived_Type) then
4857 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
4858 Set_Discriminant_Constraint (Derived_Type, No_Elist);
4860 Save_Discr_Constr := No_Elist;
4863 -- Save the Etype field of Derived_Type. It is correctly set now, but
4864 -- the call to New_Copy tree may remap it to point to itself, which
4865 -- is not what we want. Ditto for the Next_Entity field.
4867 Save_Etype := Etype (Derived_Type);
4868 Save_Next_Entity := Next_Entity (Derived_Type);
4870 -- Assoc_List maps all girder discriminants in the Parent_Base to
4871 -- girder discriminants in the Derived_Type. It is fundamental that
4872 -- no types or itypes with discriminants other than the girder
4873 -- discriminants appear in the entities declared inside
4874 -- Derived_Type. Gigi won't like it.
4878 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
4880 -- Restore the fields saved prior to the New_Copy_Tree call
4881 -- and compute the girder constraint.
4883 Set_Etype (Derived_Type, Save_Etype);
4884 Set_Next_Entity (Derived_Type, Save_Next_Entity);
4886 if Has_Discriminants (Derived_Type) then
4887 Set_Discriminant_Constraint
4888 (Derived_Type, Save_Discr_Constr);
4889 Set_Girder_Constraint
4890 (Derived_Type, Expand_To_Girder_Constraint (Parent_Base, Discs));
4893 -- Insert the new derived type declaration
4895 Rewrite (N, New_Decl);
4897 -- STEP 5b: Complete the processing for record extensions in generics
4899 -- There is no completion for record extensions declared in the
4900 -- parameter part of a generic, so we need to complete processing for
4901 -- these generic record extensions here. The call to
4902 -- Record_Type_Definition will change the Ekind of the components
4903 -- from E_Void to E_Component.
4905 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
4906 Record_Type_Definition (Empty, Derived_Type);
4908 -- STEP 5c: Process the record extension for non private tagged types.
4910 elsif not Private_Extension then
4911 -- Add the _parent field in the derived type.
4913 Expand_Derived_Record (Derived_Type, Type_Def);
4915 -- Analyze the record extension
4917 Record_Type_Definition
4918 (Record_Extension_Part (Type_Def), Derived_Type);
4923 if Etype (Derived_Type) = Any_Type then
4927 -- Set delayed freeze and then derive subprograms, we need to do
4928 -- this in this order so that derived subprograms inherit the
4929 -- derived freeze if necessary.
4931 Set_Has_Delayed_Freeze (Derived_Type);
4932 if Derive_Subps then
4933 Derive_Subprograms (Parent_Type, Derived_Type);
4936 -- If we have a private extension which defines a constrained derived
4937 -- type mark as constrained here after we have derived subprograms. See
4938 -- comment on point 9. just above the body of Build_Derived_Record_Type.
4940 if Private_Extension and then Inherit_Discrims then
4941 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
4942 Set_Is_Constrained (Derived_Type, True);
4943 Set_Discriminant_Constraint (Derived_Type, Discs);
4945 elsif Is_Constrained (Parent_Type) then
4947 (Derived_Type, True);
4948 Set_Discriminant_Constraint
4949 (Derived_Type, Discriminant_Constraint (Parent_Type));
4953 end Build_Derived_Record_Type;
4955 ------------------------
4956 -- Build_Derived_Type --
4957 ------------------------
4959 procedure Build_Derived_Type
4961 Parent_Type : Entity_Id;
4962 Derived_Type : Entity_Id;
4963 Is_Completion : Boolean;
4964 Derive_Subps : Boolean := True)
4966 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
4969 -- Set common attributes
4971 Set_Scope (Derived_Type, Current_Scope);
4973 Set_Ekind (Derived_Type, Ekind (Parent_Base));
4974 Set_Etype (Derived_Type, Parent_Base);
4975 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
4977 Set_Size_Info (Derived_Type, Parent_Type);
4978 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
4979 Set_Convention (Derived_Type, Convention (Parent_Type));
4980 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
4982 case Ekind (Parent_Type) is
4983 when Numeric_Kind =>
4984 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
4987 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
4991 | Class_Wide_Kind =>
4992 Build_Derived_Record_Type
4993 (N, Parent_Type, Derived_Type, Derive_Subps);
4996 when Enumeration_Kind =>
4997 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
5000 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
5002 when Incomplete_Or_Private_Kind =>
5003 Build_Derived_Private_Type
5004 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
5006 -- For discriminated types, the derivation includes deriving
5007 -- primitive operations. For others it is done below.
5009 if Is_Tagged_Type (Parent_Type)
5010 or else Has_Discriminants (Parent_Type)
5011 or else (Present (Full_View (Parent_Type))
5012 and then Has_Discriminants (Full_View (Parent_Type)))
5017 when Concurrent_Kind =>
5018 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
5021 raise Program_Error;
5024 if Etype (Derived_Type) = Any_Type then
5028 -- Set delayed freeze and then derive subprograms, we need to do
5029 -- this in this order so that derived subprograms inherit the
5030 -- derived freeze if necessary.
5032 Set_Has_Delayed_Freeze (Derived_Type);
5033 if Derive_Subps then
5034 Derive_Subprograms (Parent_Type, Derived_Type);
5037 Set_Has_Primitive_Operations
5038 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
5039 end Build_Derived_Type;
5041 -----------------------
5042 -- Build_Discriminal --
5043 -----------------------
5045 procedure Build_Discriminal (Discrim : Entity_Id) is
5046 D_Minal : Entity_Id;
5047 CR_Disc : Entity_Id;
5050 -- A discriminal has the same names as the discriminant.
5052 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5054 Set_Ekind (D_Minal, E_In_Parameter);
5055 Set_Mechanism (D_Minal, Default_Mechanism);
5056 Set_Etype (D_Minal, Etype (Discrim));
5058 Set_Discriminal (Discrim, D_Minal);
5059 Set_Discriminal_Link (D_Minal, Discrim);
5061 -- For task types, build at once the discriminants of the corresponding
5062 -- record, which are needed if discriminants are used in entry defaults
5063 -- and in family bounds.
5065 if Is_Concurrent_Type (Current_Scope)
5066 or else Is_Limited_Type (Current_Scope)
5068 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
5070 Set_Ekind (CR_Disc, E_In_Parameter);
5071 Set_Mechanism (CR_Disc, Default_Mechanism);
5072 Set_Etype (CR_Disc, Etype (Discrim));
5073 Set_CR_Discriminant (Discrim, CR_Disc);
5075 end Build_Discriminal;
5077 ------------------------------------
5078 -- Build_Discriminant_Constraints --
5079 ------------------------------------
5081 function Build_Discriminant_Constraints
5084 Derived_Def : Boolean := False)
5087 C : constant Node_Id := Constraint (Def);
5088 Nb_Discr : constant Nat := Number_Discriminants (T);
5089 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
5090 -- Saves the expression corresponding to a given discriminant in T.
5092 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
5093 -- Return the Position number within array Discr_Expr of a discriminant
5094 -- D within the discriminant list of the discriminated type T.
5100 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
5104 Disc := First_Discriminant (T);
5105 for J in Discr_Expr'Range loop
5110 Next_Discriminant (Disc);
5113 -- Note: Since this function is called on discriminants that are
5114 -- known to belong to the discriminated type, falling through the
5115 -- loop with no match signals an internal compiler error.
5117 raise Program_Error;
5120 -- Variables local to Build_Discriminant_Constraints
5124 Elist : Elist_Id := New_Elmt_List;
5132 Discrim_Present : Boolean := False;
5134 -- Start of processing for Build_Discriminant_Constraints
5137 -- The following loop will process positional associations only.
5138 -- For a positional association, the (single) discriminant is
5139 -- implicitly specified by position, in textual order (RM 3.7.2).
5141 Discr := First_Discriminant (T);
5142 Constr := First (Constraints (C));
5144 for D in Discr_Expr'Range loop
5145 exit when Nkind (Constr) = N_Discriminant_Association;
5148 Error_Msg_N ("too few discriminants given in constraint", C);
5149 return New_Elmt_List;
5151 elsif Nkind (Constr) = N_Range
5152 or else (Nkind (Constr) = N_Attribute_Reference
5154 Attribute_Name (Constr) = Name_Range)
5157 ("a range is not a valid discriminant constraint", Constr);
5158 Discr_Expr (D) := Error;
5161 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
5162 Discr_Expr (D) := Constr;
5165 Next_Discriminant (Discr);
5169 if No (Discr) and then Present (Constr) then
5170 Error_Msg_N ("too many discriminants given in constraint", Constr);
5171 return New_Elmt_List;
5174 -- Named associations can be given in any order, but if both positional
5175 -- and named associations are used in the same discriminant constraint,
5176 -- then positional associations must occur first, at their normal
5177 -- position. Hence once a named association is used, the rest of the
5178 -- discriminant constraint must use only named associations.
5180 while Present (Constr) loop
5182 -- Positional association forbidden after a named association.
5184 if Nkind (Constr) /= N_Discriminant_Association then
5185 Error_Msg_N ("positional association follows named one", Constr);
5186 return New_Elmt_List;
5188 -- Otherwise it is a named association
5191 -- E records the type of the discriminants in the named
5192 -- association. All the discriminants specified in the same name
5193 -- association must have the same type.
5197 -- Search the list of discriminants in T to see if the simple name
5198 -- given in the constraint matches any of them.
5200 Id := First (Selector_Names (Constr));
5201 while Present (Id) loop
5204 -- If Original_Discriminant is present, we are processing a
5205 -- generic instantiation and this is an instance node. We need
5206 -- to find the name of the corresponding discriminant in the
5207 -- actual record type T and not the name of the discriminant in
5208 -- the generic formal. Example:
5211 -- type G (D : int) is private;
5213 -- subtype W is G (D => 1);
5215 -- type Rec (X : int) is record ... end record;
5216 -- package Q is new P (G => Rec);
5218 -- At the point of the instantiation, formal type G is Rec
5219 -- and therefore when reanalyzing "subtype W is G (D => 1);"
5220 -- which really looks like "subtype W is Rec (D => 1);" at
5221 -- the point of instantiation, we want to find the discriminant
5222 -- that corresponds to D in Rec, ie X.
5224 if Present (Original_Discriminant (Id)) then
5225 Discr := Find_Corresponding_Discriminant (Id, T);
5229 Discr := First_Discriminant (T);
5230 while Present (Discr) loop
5231 if Chars (Discr) = Chars (Id) then
5236 Next_Discriminant (Discr);
5240 Error_Msg_N ("& does not match any discriminant", Id);
5241 return New_Elmt_List;
5243 -- The following is only useful for the benefit of generic
5244 -- instances but it does not interfere with other
5245 -- processsing for the non-generic case so we do it in all
5246 -- cases (for generics this statement is executed when
5247 -- processing the generic definition, see comment at the
5248 -- begining of this if statement).
5251 Set_Original_Discriminant (Id, Discr);
5255 Position := Pos_Of_Discr (T, Discr);
5257 if Present (Discr_Expr (Position)) then
5258 Error_Msg_N ("duplicate constraint for discriminant&", Id);
5261 -- Each discriminant specified in the same named association
5262 -- must be associated with a separate copy of the
5263 -- corresponding expression.
5265 if Present (Next (Id)) then
5266 Expr := New_Copy_Tree (Expression (Constr));
5267 Set_Parent (Expr, Parent (Expression (Constr)));
5269 Expr := Expression (Constr);
5272 Discr_Expr (Position) := Expr;
5273 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
5276 -- A discriminant association with more than one discriminant
5277 -- name is only allowed if the named discriminants are all of
5278 -- the same type (RM 3.7.1(8)).
5281 E := Base_Type (Etype (Discr));
5283 elsif Base_Type (Etype (Discr)) /= E then
5285 ("all discriminants in an association " &
5286 "must have the same type", Id);
5296 -- A discriminant constraint must provide exactly one value for each
5297 -- discriminant of the type (RM 3.7.1(8)).
5299 for J in Discr_Expr'Range loop
5300 if No (Discr_Expr (J)) then
5301 Error_Msg_N ("too few discriminants given in constraint", C);
5302 return New_Elmt_List;
5306 -- Determine if there are discriminant expressions in the constraint.
5308 for J in Discr_Expr'Range loop
5309 if Denotes_Discriminant (Discr_Expr (J)) then
5310 Discrim_Present := True;
5314 -- Build an element list consisting of the expressions given in the
5315 -- discriminant constraint and apply the appropriate range
5316 -- checks. The list is constructed after resolving any named
5317 -- discriminant associations and therefore the expressions appear in
5318 -- the textual order of the discriminants.
5320 Discr := First_Discriminant (T);
5321 for J in Discr_Expr'Range loop
5322 if Discr_Expr (J) /= Error then
5324 Append_Elmt (Discr_Expr (J), Elist);
5326 -- If any of the discriminant constraints is given by a
5327 -- discriminant and we are in a derived type declaration we
5328 -- have a discriminant renaming. Establish link between new
5329 -- and old discriminant.
5331 if Denotes_Discriminant (Discr_Expr (J)) then
5333 Set_Corresponding_Discriminant
5334 (Entity (Discr_Expr (J)), Discr);
5337 -- Force the evaluation of non-discriminant expressions.
5338 -- If we have found a discriminant in the constraint 3.4(26)
5339 -- and 3.8(18) demand that no range checks are performed are
5340 -- after evaluation. In all other cases perform a range check.
5343 if not Discrim_Present then
5344 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
5347 Force_Evaluation (Discr_Expr (J));
5350 -- Check that the designated type of an access discriminant's
5351 -- expression is not a class-wide type unless the discriminant's
5352 -- designated type is also class-wide.
5354 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
5355 and then not Is_Class_Wide_Type
5356 (Designated_Type (Etype (Discr)))
5357 and then Etype (Discr_Expr (J)) /= Any_Type
5358 and then Is_Class_Wide_Type
5359 (Designated_Type (Etype (Discr_Expr (J))))
5361 Wrong_Type (Discr_Expr (J), Etype (Discr));
5365 Next_Discriminant (Discr);
5369 end Build_Discriminant_Constraints;
5371 ---------------------------------
5372 -- Build_Discriminated_Subtype --
5373 ---------------------------------
5375 procedure Build_Discriminated_Subtype
5379 Related_Nod : Node_Id;
5380 For_Access : Boolean := False)
5382 Has_Discrs : constant Boolean := Has_Discriminants (T);
5383 Constrained : constant Boolean
5384 := (Has_Discrs and then not Is_Empty_Elmt_List (Elist))
5385 or else Is_Constrained (T);
5388 if Ekind (T) = E_Record_Type then
5390 Set_Ekind (Def_Id, E_Private_Subtype);
5391 Set_Is_For_Access_Subtype (Def_Id, True);
5393 Set_Ekind (Def_Id, E_Record_Subtype);
5396 elsif Ekind (T) = E_Task_Type then
5397 Set_Ekind (Def_Id, E_Task_Subtype);
5399 elsif Ekind (T) = E_Protected_Type then
5400 Set_Ekind (Def_Id, E_Protected_Subtype);
5402 elsif Is_Private_Type (T) then
5403 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
5405 elsif Is_Class_Wide_Type (T) then
5406 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
5409 -- Incomplete type. Attach subtype to list of dependents, to be
5410 -- completed with full view of parent type.
5412 Set_Ekind (Def_Id, Ekind (T));
5413 Append_Elmt (Def_Id, Private_Dependents (T));
5416 Set_Etype (Def_Id, T);
5417 Init_Size_Align (Def_Id);
5418 Set_Has_Discriminants (Def_Id, Has_Discrs);
5419 Set_Is_Constrained (Def_Id, Constrained);
5421 Set_First_Entity (Def_Id, First_Entity (T));
5422 Set_Last_Entity (Def_Id, Last_Entity (T));
5423 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
5425 if Is_Tagged_Type (T) then
5426 Set_Is_Tagged_Type (Def_Id);
5427 Make_Class_Wide_Type (Def_Id);
5430 Set_Girder_Constraint (Def_Id, No_Elist);
5433 Set_Discriminant_Constraint (Def_Id, Elist);
5434 Set_Girder_Constraint_From_Discriminant_Constraint (Def_Id);
5437 if Is_Tagged_Type (T) then
5438 Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
5439 Set_Is_Abstract (Def_Id, Is_Abstract (T));
5442 -- Subtypes introduced by component declarations do not need to be
5443 -- marked as delayed, and do not get freeze nodes, because the semantics
5444 -- verifies that the parents of the subtypes are frozen before the
5445 -- enclosing record is frozen.
5447 if not Is_Type (Scope (Def_Id)) then
5448 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
5450 if Is_Private_Type (T)
5451 and then Present (Full_View (T))
5453 Conditional_Delay (Def_Id, Full_View (T));
5455 Conditional_Delay (Def_Id, T);
5459 if Is_Record_Type (T) then
5460 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
5463 and then not Is_Empty_Elmt_List (Elist)
5464 and then not For_Access
5466 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
5467 elsif not For_Access then
5468 Set_Cloned_Subtype (Def_Id, T);
5472 end Build_Discriminated_Subtype;
5474 ------------------------
5475 -- Build_Scalar_Bound --
5476 ------------------------
5478 function Build_Scalar_Bound
5485 New_Bound : Entity_Id;
5488 -- Note: not clear why this is needed, how can the original bound
5489 -- be unanalyzed at this point? and if it is, what business do we
5490 -- have messing around with it? and why is the base type of the
5491 -- parent type the right type for the resolution. It probably is
5492 -- not! It is OK for the new bound we are creating, but not for
5493 -- the old one??? Still if it never happens, no problem!
5495 Analyze_And_Resolve (Bound, Base_Type (Par_T));
5497 if Nkind (Bound) = N_Integer_Literal
5498 or else Nkind (Bound) = N_Real_Literal
5500 New_Bound := New_Copy (Bound);
5501 Set_Etype (New_Bound, Der_T);
5502 Set_Analyzed (New_Bound);
5504 elsif Is_Entity_Name (Bound) then
5505 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
5507 -- The following is almost certainly wrong. What business do we have
5508 -- relocating a node (Bound) that is presumably still attached to
5509 -- the tree elsewhere???
5512 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
5515 Set_Etype (New_Bound, Der_T);
5517 end Build_Scalar_Bound;
5519 --------------------------------
5520 -- Build_Underlying_Full_View --
5521 --------------------------------
5523 procedure Build_Underlying_Full_View
5528 Loc : constant Source_Ptr := Sloc (N);
5529 Subt : constant Entity_Id :=
5530 Make_Defining_Identifier
5531 (Loc, New_External_Name (Chars (Typ), 'S'));
5539 if Nkind (N) = N_Full_Type_Declaration then
5540 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
5542 -- ??? ??? is this assert right, I assume so otherwise Constr
5543 -- would not be defined below (this used to be an elsif)
5545 else pragma Assert (Nkind (N) = N_Subtype_Declaration);
5546 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
5549 -- If the constraint has discriminant associations, the discriminant
5550 -- entity is already set, but it denotes a discriminant of the new
5551 -- type, not the original parent, so it must be found anew.
5553 C := First (Constraints (Constr));
5555 while Present (C) loop
5557 if Nkind (C) = N_Discriminant_Association then
5558 Id := First (Selector_Names (C));
5560 while Present (Id) loop
5561 Set_Original_Discriminant (Id, Empty);
5569 Indic := Make_Subtype_Declaration (Loc,
5570 Defining_Identifier => Subt,
5571 Subtype_Indication =>
5572 Make_Subtype_Indication (Loc,
5573 Subtype_Mark => New_Reference_To (Par, Loc),
5574 Constraint => New_Copy_Tree (Constr)));
5576 Insert_Before (N, Indic);
5578 Set_Underlying_Full_View (Typ, Full_View (Subt));
5579 end Build_Underlying_Full_View;
5581 -------------------------------
5582 -- Check_Abstract_Overriding --
5583 -------------------------------
5585 procedure Check_Abstract_Overriding (T : Entity_Id) is
5592 Op_List := Primitive_Operations (T);
5594 -- Loop to check primitive operations
5596 Elmt := First_Elmt (Op_List);
5597 while Present (Elmt) loop
5598 Subp := Node (Elmt);
5600 -- Special exception, do not complain about failure to
5601 -- override _Input and _Output, since we always provide
5602 -- automatic overridings for these subprograms.
5604 if Is_Abstract (Subp)
5605 and then Chars (Subp) /= Name_uInput
5606 and then Chars (Subp) /= Name_uOutput
5607 and then not Is_Abstract (T)
5609 if Present (Alias (Subp)) then
5610 -- Only perform the check for a derived subprogram when
5611 -- the type has an explicit record extension. This avoids
5612 -- incorrectly flagging abstract subprograms for the case
5613 -- of a type without an extension derived from a formal type
5614 -- with a tagged actual (can occur within a private part).
5616 Type_Def := Type_Definition (Parent (T));
5617 if Nkind (Type_Def) = N_Derived_Type_Definition
5618 and then Present (Record_Extension_Part (Type_Def))
5621 ("type must be declared abstract or & overridden",
5626 ("abstract subprogram not allowed for type&",
5629 ("nonabstract type has abstract subprogram&",
5636 end Check_Abstract_Overriding;
5638 ------------------------------------------------
5639 -- Check_Access_Discriminant_Requires_Limited --
5640 ------------------------------------------------
5642 procedure Check_Access_Discriminant_Requires_Limited
5647 -- A discriminant_specification for an access discriminant
5648 -- shall appear only in the declaration for a task or protected
5649 -- type, or for a type with the reserved word 'limited' in
5650 -- its definition or in one of its ancestors. (RM 3.7(10))
5652 if Nkind (Discriminant_Type (D)) = N_Access_Definition
5653 and then not Is_Concurrent_Type (Current_Scope)
5654 and then not Is_Concurrent_Record_Type (Current_Scope)
5655 and then not Is_Limited_Record (Current_Scope)
5656 and then Ekind (Current_Scope) /= E_Limited_Private_Type
5659 ("access discriminants allowed only for limited types", Loc);
5661 end Check_Access_Discriminant_Requires_Limited;
5663 -----------------------------------
5664 -- Check_Aliased_Component_Types --
5665 -----------------------------------
5667 procedure Check_Aliased_Component_Types (T : Entity_Id) is
5671 -- ??? Also need to check components of record extensions,
5672 -- but not components of protected types (which are always
5675 if not Is_Limited_Type (T) then
5676 if Ekind (T) = E_Record_Type then
5677 C := First_Component (T);
5678 while Present (C) loop
5680 and then Has_Discriminants (Etype (C))
5681 and then not Is_Constrained (Etype (C))
5682 and then not In_Instance
5685 ("aliased component must be constrained ('R'M 3.6(11))",
5692 elsif Ekind (T) = E_Array_Type then
5693 if Has_Aliased_Components (T)
5694 and then Has_Discriminants (Component_Type (T))
5695 and then not Is_Constrained (Component_Type (T))
5696 and then not In_Instance
5699 ("aliased component type must be constrained ('R'M 3.6(11))",
5704 end Check_Aliased_Component_Types;
5706 ----------------------
5707 -- Check_Completion --
5708 ----------------------
5710 procedure Check_Completion (Body_Id : Node_Id := Empty) is
5713 procedure Post_Error;
5714 -- Post error message for lack of completion for entity E
5716 procedure Post_Error is
5718 if not Comes_From_Source (E) then
5720 if (Ekind (E) = E_Task_Type
5721 or else Ekind (E) = E_Protected_Type)
5723 -- It may be an anonymous protected type created for a
5724 -- single variable. Post error on variable, if present.
5730 Var := First_Entity (Current_Scope);
5732 while Present (Var) loop
5733 exit when Etype (Var) = E
5734 and then Comes_From_Source (Var);
5739 if Present (Var) then
5746 -- If a generated entity has no completion, then either previous
5747 -- semantic errors have disabled the expansion phase, or else
5748 -- we had missing subunits, or else we are compiling without expan-
5749 -- sion, or else something is very wrong.
5751 if not Comes_From_Source (E) then
5753 (Errors_Detected > 0
5754 or else Subunits_Missing
5755 or else not Expander_Active);
5758 -- Here for source entity
5761 -- Here if no body to post the error message, so we post the error
5762 -- on the declaration that has no completion. This is not really
5763 -- the right place to post it, think about this later ???
5765 if No (Body_Id) then
5768 ("missing full declaration for }", Parent (E), E);
5771 ("missing body for &", Parent (E), E);
5774 -- Package body has no completion for a declaration that appears
5775 -- in the corresponding spec. Post error on the body, with a
5776 -- reference to the non-completed declaration.
5779 Error_Msg_Sloc := Sloc (E);
5783 ("missing full declaration for }!", Body_Id, E);
5785 elsif Is_Overloadable (E)
5786 and then Current_Entity_In_Scope (E) /= E
5788 -- It may be that the completion is mistyped and appears
5789 -- as a distinct overloading of the entity.
5792 Candidate : Entity_Id := Current_Entity_In_Scope (E);
5793 Decl : Node_Id := Unit_Declaration_Node (Candidate);
5796 if Is_Overloadable (Candidate)
5797 and then Ekind (Candidate) = Ekind (E)
5798 and then Nkind (Decl) = N_Subprogram_Body
5799 and then Acts_As_Spec (Decl)
5801 Check_Type_Conformant (Candidate, E);
5804 Error_Msg_NE ("missing body for & declared#!",
5809 Error_Msg_NE ("missing body for & declared#!",
5816 -- Start processing for Check_Completion
5819 E := First_Entity (Current_Scope);
5820 while Present (E) loop
5821 if Is_Intrinsic_Subprogram (E) then
5824 -- The following situation requires special handling: a child
5825 -- unit that appears in the context clause of the body of its
5828 -- procedure Parent.Child (...);
5830 -- with Parent.Child;
5831 -- package body Parent is
5833 -- Here Parent.Child appears as a local entity, but should not
5834 -- be flagged as requiring completion, because it is a
5835 -- compilation unit.
5837 elsif Ekind (E) = E_Function
5838 or else Ekind (E) = E_Procedure
5839 or else Ekind (E) = E_Generic_Function
5840 or else Ekind (E) = E_Generic_Procedure
5842 if not Has_Completion (E)
5843 and then not Is_Abstract (E)
5844 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5846 and then Chars (E) /= Name_uSize
5851 elsif Is_Entry (E) then
5852 if not Has_Completion (E) and then
5853 (Ekind (Scope (E)) = E_Protected_Object
5854 or else Ekind (Scope (E)) = E_Protected_Type)
5859 elsif Is_Package (E) then
5860 if Unit_Requires_Body (E) then
5861 if not Has_Completion (E)
5862 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
5868 elsif not Is_Child_Unit (E) then
5869 May_Need_Implicit_Body (E);
5872 elsif Ekind (E) = E_Incomplete_Type
5873 and then No (Underlying_Type (E))
5877 elsif (Ekind (E) = E_Task_Type or else
5878 Ekind (E) = E_Protected_Type)
5879 and then not Has_Completion (E)
5883 elsif Ekind (E) = E_Constant
5884 and then Ekind (Etype (E)) = E_Task_Type
5885 and then not Has_Completion (Etype (E))
5889 elsif Ekind (E) = E_Protected_Object
5890 and then not Has_Completion (Etype (E))
5894 elsif Ekind (E) = E_Record_Type then
5895 if Is_Tagged_Type (E) then
5896 Check_Abstract_Overriding (E);
5899 Check_Aliased_Component_Types (E);
5901 elsif Ekind (E) = E_Array_Type then
5902 Check_Aliased_Component_Types (E);
5908 end Check_Completion;
5910 ----------------------------
5911 -- Check_Delta_Expression --
5912 ----------------------------
5914 procedure Check_Delta_Expression (E : Node_Id) is
5916 if not (Is_Real_Type (Etype (E))) then
5917 Wrong_Type (E, Any_Real);
5919 elsif not Is_OK_Static_Expression (E) then
5920 Error_Msg_N ("non-static expression used for delta value", E);
5922 elsif not UR_Is_Positive (Expr_Value_R (E)) then
5923 Error_Msg_N ("delta expression must be positive", E);
5929 -- If any of above errors occurred, then replace the incorrect
5930 -- expression by the real 0.1, which should prevent further errors.
5933 Make_Real_Literal (Sloc (E), Ureal_Tenth));
5934 Analyze_And_Resolve (E, Standard_Float);
5936 end Check_Delta_Expression;
5938 -----------------------------
5939 -- Check_Digits_Expression --
5940 -----------------------------
5942 procedure Check_Digits_Expression (E : Node_Id) is
5944 if not (Is_Integer_Type (Etype (E))) then
5945 Wrong_Type (E, Any_Integer);
5947 elsif not Is_OK_Static_Expression (E) then
5948 Error_Msg_N ("non-static expression used for digits value", E);
5950 elsif Expr_Value (E) <= 0 then
5951 Error_Msg_N ("digits value must be greater than zero", E);
5957 -- If any of above errors occurred, then replace the incorrect
5958 -- expression by the integer 1, which should prevent further errors.
5960 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
5961 Analyze_And_Resolve (E, Standard_Integer);
5963 end Check_Digits_Expression;
5965 ----------------------
5966 -- Check_Incomplete --
5967 ----------------------
5969 procedure Check_Incomplete (T : Entity_Id) is
5971 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
5972 Error_Msg_N ("invalid use of type before its full declaration", T);
5974 end Check_Incomplete;
5976 --------------------------
5977 -- Check_Initialization --
5978 --------------------------
5980 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
5982 if (Is_Limited_Type (T)
5983 or else Is_Limited_Composite (T))
5984 and then not In_Instance
5987 ("cannot initialize entities of limited type", Exp);
5989 end Check_Initialization;
5991 ------------------------------------
5992 -- Check_Or_Process_Discriminants --
5993 ------------------------------------
5995 -- If an incomplete or private type declaration was already given for
5996 -- the type, the discriminants may have already been processed if they
5997 -- were present on the incomplete declaration. In this case a full
5998 -- conformance check is performed otherwise just process them.
6000 procedure Check_Or_Process_Discriminants (N : Node_Id; T : Entity_Id) is
6002 if Has_Discriminants (T) then
6004 -- Make the discriminants visible to component declarations.
6007 D : Entity_Id := First_Discriminant (T);
6011 while Present (D) loop
6012 Prev := Current_Entity (D);
6013 Set_Current_Entity (D);
6014 Set_Is_Immediately_Visible (D);
6015 Set_Homonym (D, Prev);
6017 -- This restriction gets applied to the full type here; it
6018 -- has already been applied earlier to the partial view
6020 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
6022 Next_Discriminant (D);
6026 elsif Present (Discriminant_Specifications (N)) then
6027 Process_Discriminants (N);
6029 end Check_Or_Process_Discriminants;
6031 ----------------------
6032 -- Check_Real_Bound --
6033 ----------------------
6035 procedure Check_Real_Bound (Bound : Node_Id) is
6037 if not Is_Real_Type (Etype (Bound)) then
6039 ("bound in real type definition must be of real type", Bound);
6041 elsif not Is_OK_Static_Expression (Bound) then
6043 ("non-static expression used for real type bound", Bound);
6050 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
6052 Resolve (Bound, Standard_Float);
6053 end Check_Real_Bound;
6055 ------------------------------
6056 -- Complete_Private_Subtype --
6057 ------------------------------
6059 procedure Complete_Private_Subtype
6062 Full_Base : Entity_Id;
6063 Related_Nod : Node_Id)
6065 Save_Next_Entity : Entity_Id;
6066 Save_Homonym : Entity_Id;
6069 -- Set semantic attributes for (implicit) private subtype completion.
6070 -- If the full type has no discriminants, then it is a copy of the full
6071 -- view of the base. Otherwise, it is a subtype of the base with a
6072 -- possible discriminant constraint. Save and restore the original
6073 -- Next_Entity field of full to ensure that the calls to Copy_Node
6074 -- do not corrupt the entity chain.
6076 -- Note that the type of the full view is the same entity as the
6077 -- type of the partial view. In this fashion, the subtype has
6078 -- access to the correct view of the parent.
6080 Save_Next_Entity := Next_Entity (Full);
6081 Save_Homonym := Homonym (Priv);
6083 case Ekind (Full_Base) is
6085 when E_Record_Type |
6091 Copy_Node (Priv, Full);
6093 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
6094 Set_First_Entity (Full, First_Entity (Full_Base));
6095 Set_Last_Entity (Full, Last_Entity (Full_Base));
6098 Copy_Node (Full_Base, Full);
6099 Set_Chars (Full, Chars (Priv));
6100 Conditional_Delay (Full, Priv);
6101 Set_Sloc (Full, Sloc (Priv));
6105 Set_Next_Entity (Full, Save_Next_Entity);
6106 Set_Homonym (Full, Save_Homonym);
6107 Set_Associated_Node_For_Itype (Full, Related_Nod);
6109 -- Set common attributes for all subtypes.
6111 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
6113 -- The Etype of the full view is inconsistent. Gigi needs to see the
6114 -- structural full view, which is what the current scheme gives:
6115 -- the Etype of the full view is the etype of the full base. However,
6116 -- if the full base is a derived type, the full view then looks like
6117 -- a subtype of the parent, not a subtype of the full base. If instead
6120 -- Set_Etype (Full, Full_Base);
6122 -- then we get inconsistencies in the front-end (confusion between
6123 -- views). Several outstanding bugs are related to this.
6125 Set_Is_First_Subtype (Full, False);
6126 Set_Scope (Full, Scope (Priv));
6127 Set_Size_Info (Full, Full_Base);
6128 Set_RM_Size (Full, RM_Size (Full_Base));
6129 Set_Is_Itype (Full);
6131 -- A subtype of a private-type-without-discriminants, whose full-view
6132 -- has discriminants with default expressions, is not constrained!
6134 if not Has_Discriminants (Priv) then
6135 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
6138 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
6139 Set_Depends_On_Private (Full, Has_Private_Component (Full));
6141 -- Freeze the private subtype entity if its parent is delayed,
6142 -- and not already frozen. We skip this processing if the type
6143 -- is an anonymous subtype of a record component, or is the
6144 -- corresponding record of a protected type, since ???
6146 if not Is_Type (Scope (Full)) then
6147 Set_Has_Delayed_Freeze (Full,
6148 Has_Delayed_Freeze (Full_Base)
6149 and then (not Is_Frozen (Full_Base)));
6152 Set_Freeze_Node (Full, Empty);
6153 Set_Is_Frozen (Full, False);
6154 Set_Full_View (Priv, Full);
6156 if Has_Discriminants (Full) then
6157 Set_Girder_Constraint_From_Discriminant_Constraint (Full);
6158 Set_Girder_Constraint (Priv, Girder_Constraint (Full));
6159 if Has_Unknown_Discriminants (Full) then
6160 Set_Discriminant_Constraint (Full, No_Elist);
6164 if Ekind (Full_Base) = E_Record_Type
6165 and then Has_Discriminants (Full_Base)
6166 and then Has_Discriminants (Priv) -- might not, if errors
6167 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
6169 Create_Constrained_Components
6170 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
6172 -- If the full base is itself derived from private, build a congruent
6173 -- subtype of its underlying type, for use by the back end.
6175 elsif Ekind (Full_Base) in Private_Kind
6176 and then Is_Derived_Type (Full_Base)
6177 and then Has_Discriminants (Full_Base)
6179 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
6181 Build_Underlying_Full_View (Parent (Priv), Full, Etype (Full_Base));
6183 elsif Is_Record_Type (Full_Base) then
6185 -- Show Full is simply a renaming of Full_Base.
6187 Set_Cloned_Subtype (Full, Full_Base);
6190 -- It is usafe to share to bounds of a scalar type, because the
6191 -- Itype is elaborated on demand, and if a bound is non-static
6192 -- then different orders of elaboration in different units will
6193 -- lead to different external symbols.
6195 if Is_Scalar_Type (Full_Base) then
6196 Set_Scalar_Range (Full,
6197 Make_Range (Sloc (Related_Nod),
6198 Low_Bound => Duplicate_Subexpr (Type_Low_Bound (Full_Base)),
6199 High_Bound => Duplicate_Subexpr (Type_High_Bound (Full_Base))));
6202 -- ??? It seems that a lot of fields are missing that should be
6203 -- copied from Full_Base to Full. Here are some that are introduced
6204 -- in a non-disruptive way but a cleanup is necessary.
6206 if Is_Tagged_Type (Full_Base) then
6207 Set_Is_Tagged_Type (Full);
6208 Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
6210 elsif Is_Concurrent_Type (Full_Base) then
6212 if Has_Discriminants (Full)
6213 and then Present (Corresponding_Record_Type (Full_Base))
6215 Set_Corresponding_Record_Type (Full,
6216 Constrain_Corresponding_Record
6217 (Full, Corresponding_Record_Type (Full_Base),
6218 Related_Nod, Full_Base));
6221 Set_Corresponding_Record_Type (Full,
6222 Corresponding_Record_Type (Full_Base));
6226 end Complete_Private_Subtype;
6228 ----------------------------
6229 -- Constant_Redeclaration --
6230 ----------------------------
6232 procedure Constant_Redeclaration
6237 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
6238 Obj_Def : constant Node_Id := Object_Definition (N);
6242 if Nkind (Parent (Prev)) = N_Object_Declaration then
6243 if Nkind (Object_Definition
6244 (Parent (Prev))) = N_Subtype_Indication
6246 -- Find type of new declaration. The constraints of the two
6247 -- views must match statically, but there is no point in
6248 -- creating an itype for the full view.
6250 if Nkind (Obj_Def) = N_Subtype_Indication then
6251 Find_Type (Subtype_Mark (Obj_Def));
6252 New_T := Entity (Subtype_Mark (Obj_Def));
6255 Find_Type (Obj_Def);
6256 New_T := Entity (Obj_Def);
6262 -- The full view may impose a constraint, even if the partial
6263 -- view does not, so construct the subtype.
6265 New_T := Find_Type_Of_Object (Obj_Def, N);
6270 -- Current declaration is illegal, diagnosed below in Enter_Name.
6276 -- If previous full declaration exists, or if a homograph is present,
6277 -- let Enter_Name handle it, either with an error, or with the removal
6278 -- of an overridden implicit subprogram.
6280 if Ekind (Prev) /= E_Constant
6281 or else Present (Expression (Parent (Prev)))
6285 -- Verify that types of both declarations match.
6287 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) then
6288 Error_Msg_Sloc := Sloc (Prev);
6289 Error_Msg_N ("type does not match declaration#", N);
6290 Set_Full_View (Prev, Id);
6291 Set_Etype (Id, Any_Type);
6293 -- If so, process the full constant declaration
6296 Set_Full_View (Prev, Id);
6297 Set_Is_Public (Id, Is_Public (Prev));
6298 Set_Is_Internal (Id);
6299 Append_Entity (Id, Current_Scope);
6301 -- Check ALIASED present if present before (RM 7.4(7))
6303 if Is_Aliased (Prev)
6304 and then not Aliased_Present (N)
6306 Error_Msg_Sloc := Sloc (Prev);
6307 Error_Msg_N ("ALIASED required (see declaration#)", N);
6310 -- Check that placement is in private part
6312 if Ekind (Current_Scope) = E_Package
6313 and then not In_Private_Part (Current_Scope)
6315 Error_Msg_Sloc := Sloc (Prev);
6316 Error_Msg_N ("full constant for declaration#"
6317 & " must be in private part", N);
6320 end Constant_Redeclaration;
6322 ----------------------
6323 -- Constrain_Access --
6324 ----------------------
6326 procedure Constrain_Access
6327 (Def_Id : in out Entity_Id;
6329 Related_Nod : Node_Id)
6331 T : constant Entity_Id := Entity (Subtype_Mark (S));
6332 Desig_Type : constant Entity_Id := Designated_Type (T);
6333 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
6334 Constraint_OK : Boolean := True;
6337 if Is_Array_Type (Desig_Type) then
6338 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
6340 elsif (Is_Record_Type (Desig_Type)
6341 or else Is_Incomplete_Or_Private_Type (Desig_Type))
6342 and then not Is_Constrained (Desig_Type)
6344 -- ??? The following code is a temporary kludge to ignore
6345 -- discriminant constraint on access type if
6346 -- it is constraining the current record. Avoid creating the
6347 -- implicit subtype of the record we are currently compiling
6348 -- since right now, we cannot handle these.
6349 -- For now, just return the access type itself.
6351 if Desig_Type = Current_Scope
6352 and then No (Def_Id)
6354 Set_Ekind (Desig_Subtype, E_Record_Subtype);
6355 Def_Id := Entity (Subtype_Mark (S));
6357 -- This call added to ensure that the constraint is
6358 -- analyzed (needed for a B test). Note that we
6359 -- still return early from this procedure to avoid
6360 -- recursive processing. ???
6362 Constrain_Discriminated_Type
6363 (Desig_Subtype, S, Related_Nod, For_Access => True);
6368 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
6369 For_Access => True);
6371 elsif (Is_Task_Type (Desig_Type)
6372 or else Is_Protected_Type (Desig_Type))
6373 and then not Is_Constrained (Desig_Type)
6375 Constrain_Concurrent
6376 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
6379 Error_Msg_N ("invalid constraint on access type", S);
6380 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
6381 Constraint_OK := False;
6385 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
6387 Set_Ekind (Def_Id, E_Access_Subtype);
6390 if Constraint_OK then
6391 Set_Etype (Def_Id, Base_Type (T));
6393 if Is_Private_Type (Desig_Type) then
6394 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
6397 Set_Etype (Def_Id, Any_Type);
6400 Set_Size_Info (Def_Id, T);
6401 Set_Is_Constrained (Def_Id, Constraint_OK);
6402 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
6403 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6404 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
6406 -- Itypes created for constrained record components do not receive
6407 -- a freeze node, they are elaborated when first seen.
6409 if not Is_Record_Type (Current_Scope) then
6410 Conditional_Delay (Def_Id, T);
6412 end Constrain_Access;
6414 ---------------------
6415 -- Constrain_Array --
6416 ---------------------
6418 procedure Constrain_Array
6419 (Def_Id : in out Entity_Id;
6421 Related_Nod : Node_Id;
6422 Related_Id : Entity_Id;
6425 C : constant Node_Id := Constraint (SI);
6426 Number_Of_Constraints : Nat := 0;
6429 Constraint_OK : Boolean := True;
6432 T := Entity (Subtype_Mark (SI));
6434 if Ekind (T) in Access_Kind then
6435 T := Designated_Type (T);
6438 -- If an index constraint follows a subtype mark in a subtype indication
6439 -- then the type or subtype denoted by the subtype mark must not already
6440 -- impose an index constraint. The subtype mark must denote either an
6441 -- unconstrained array type or an access type whose designated type
6442 -- is such an array type... (RM 3.6.1)
6444 if Is_Constrained (T) then
6446 ("array type is already constrained", Subtype_Mark (SI));
6447 Constraint_OK := False;
6450 S := First (Constraints (C));
6452 while Present (S) loop
6453 Number_Of_Constraints := Number_Of_Constraints + 1;
6457 -- In either case, the index constraint must provide a discrete
6458 -- range for each index of the array type and the type of each
6459 -- discrete range must be the same as that of the corresponding
6460 -- index. (RM 3.6.1)
6462 if Number_Of_Constraints /= Number_Dimensions (T) then
6463 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
6464 Constraint_OK := False;
6467 S := First (Constraints (C));
6468 Index := First_Index (T);
6471 -- Apply constraints to each index type
6473 for J in 1 .. Number_Of_Constraints loop
6474 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
6484 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
6486 Set_Ekind (Def_Id, E_Array_Subtype);
6489 Set_Size_Info (Def_Id, (T));
6490 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
6491 Set_Etype (Def_Id, Base_Type (T));
6493 if Constraint_OK then
6494 Set_First_Index (Def_Id, First (Constraints (C)));
6497 Set_Component_Type (Def_Id, Component_Type (T));
6498 Set_Is_Constrained (Def_Id, True);
6499 Set_Is_Aliased (Def_Id, Is_Aliased (T));
6500 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6502 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
6503 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
6505 -- If the subtype is not that of a record component, build a freeze
6506 -- node if parent still needs one.
6508 -- If the subtype is not that of a record component, make sure
6509 -- that the Depends_On_Private status is set (explanation ???)
6510 -- and also that a conditional delay is set.
6512 if not Is_Type (Scope (Def_Id)) then
6513 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
6514 Conditional_Delay (Def_Id, T);
6517 end Constrain_Array;
6519 ------------------------------
6520 -- Constrain_Component_Type --
6521 ------------------------------
6523 function Constrain_Component_Type
6524 (Compon_Type : Entity_Id;
6525 Constrained_Typ : Entity_Id;
6526 Related_Node : Node_Id;
6528 Constraints : Elist_Id)
6531 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
6533 function Build_Constrained_Array_Type
6534 (Old_Type : Entity_Id)
6536 -- If Old_Type is an array type, one of whose indices is
6537 -- constrained by a discriminant, build an Itype whose constraint
6538 -- replaces the discriminant with its value in the constraint.
6540 function Build_Constrained_Discriminated_Type
6541 (Old_Type : Entity_Id)
6543 -- Ditto for record components.
6545 function Build_Constrained_Access_Type
6546 (Old_Type : Entity_Id)
6548 -- Ditto for access types. Makes use of previous two functions, to
6549 -- constrain designated type.
6551 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
6552 -- T is an array or discriminated type, C is a list of constraints
6553 -- that apply to T. This routine builds the constrained subtype.
6555 function Is_Discriminant (Expr : Node_Id) return Boolean;
6556 -- Returns True if Expr is a discriminant.
6558 function Get_Value (Discrim : Entity_Id) return Node_Id;
6559 -- Find the value of discriminant Discrim in Constraint.
6561 -----------------------------------
6562 -- Build_Constrained_Access_Type --
6563 -----------------------------------
6565 function Build_Constrained_Access_Type
6566 (Old_Type : Entity_Id)
6569 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
6571 Desig_Subtype : Entity_Id;
6575 -- if the original access type was not embedded in the enclosing
6576 -- type definition, there is no need to produce a new access
6577 -- subtype. In fact every access type with an explicit constraint
6578 -- generates an itype whose scope is the enclosing record.
6580 if not Is_Type (Scope (Old_Type)) then
6583 elsif Is_Array_Type (Desig_Type) then
6584 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
6586 elsif Has_Discriminants (Desig_Type) then
6588 -- This may be an access type to an enclosing record type for
6589 -- which we are constructing the constrained components. Return
6590 -- the enclosing record subtype. This is not always correct,
6591 -- but avoids infinite recursion. ???
6593 Desig_Subtype := Any_Type;
6595 for J in reverse 0 .. Scope_Stack.Last loop
6596 Scop := Scope_Stack.Table (J).Entity;
6599 and then Base_Type (Scop) = Base_Type (Desig_Type)
6601 Desig_Subtype := Scop;
6604 exit when not Is_Type (Scop);
6607 if Desig_Subtype = Any_Type then
6609 Build_Constrained_Discriminated_Type (Desig_Type);
6616 if Desig_Subtype /= Desig_Type then
6617 -- The Related_Node better be here or else we won't be able
6618 -- to attach new itypes to a node in the tree.
6620 pragma Assert (Present (Related_Node));
6622 Itype := Create_Itype (E_Access_Subtype, Related_Node);
6624 Set_Etype (Itype, Base_Type (Old_Type));
6625 Set_Size_Info (Itype, (Old_Type));
6626 Set_Directly_Designated_Type (Itype, Desig_Subtype);
6627 Set_Depends_On_Private (Itype, Has_Private_Component
6629 Set_Is_Access_Constant (Itype, Is_Access_Constant
6632 -- The new itype needs freezing when it depends on a not frozen
6633 -- type and the enclosing subtype needs freezing.
6635 if Has_Delayed_Freeze (Constrained_Typ)
6636 and then not Is_Frozen (Constrained_Typ)
6638 Conditional_Delay (Itype, Base_Type (Old_Type));
6646 end Build_Constrained_Access_Type;
6648 ----------------------------------
6649 -- Build_Constrained_Array_Type --
6650 ----------------------------------
6652 function Build_Constrained_Array_Type
6653 (Old_Type : Entity_Id)
6658 Old_Index : Node_Id;
6659 Range_Node : Node_Id;
6660 Constr_List : List_Id;
6662 Need_To_Create_Itype : Boolean := False;
6665 Old_Index := First_Index (Old_Type);
6666 while Present (Old_Index) loop
6667 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6669 if Is_Discriminant (Lo_Expr)
6670 or else Is_Discriminant (Hi_Expr)
6672 Need_To_Create_Itype := True;
6675 Next_Index (Old_Index);
6678 if Need_To_Create_Itype then
6679 Constr_List := New_List;
6681 Old_Index := First_Index (Old_Type);
6682 while Present (Old_Index) loop
6683 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
6685 if Is_Discriminant (Lo_Expr) then
6686 Lo_Expr := Get_Value (Lo_Expr);
6689 if Is_Discriminant (Hi_Expr) then
6690 Hi_Expr := Get_Value (Hi_Expr);
6695 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
6697 Append (Range_Node, To => Constr_List);
6699 Next_Index (Old_Index);
6702 return Build_Subtype (Old_Type, Constr_List);
6707 end Build_Constrained_Array_Type;
6709 ------------------------------------------
6710 -- Build_Constrained_Discriminated_Type --
6711 ------------------------------------------
6713 function Build_Constrained_Discriminated_Type
6714 (Old_Type : Entity_Id)
6718 Constr_List : List_Id;
6719 Old_Constraint : Elmt_Id;
6721 Need_To_Create_Itype : Boolean := False;
6724 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6725 while Present (Old_Constraint) loop
6726 Expr := Node (Old_Constraint);
6728 if Is_Discriminant (Expr) then
6729 Need_To_Create_Itype := True;
6732 Next_Elmt (Old_Constraint);
6735 if Need_To_Create_Itype then
6736 Constr_List := New_List;
6738 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
6739 while Present (Old_Constraint) loop
6740 Expr := Node (Old_Constraint);
6742 if Is_Discriminant (Expr) then
6743 Expr := Get_Value (Expr);
6746 Append (New_Copy_Tree (Expr), To => Constr_List);
6748 Next_Elmt (Old_Constraint);
6751 return Build_Subtype (Old_Type, Constr_List);
6756 end Build_Constrained_Discriminated_Type;
6762 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
6764 Subtyp_Decl : Node_Id;
6766 Btyp : Entity_Id := Base_Type (T);
6769 -- The Related_Node better be here or else we won't be able
6770 -- to attach new itypes to a node in the tree.
6772 pragma Assert (Present (Related_Node));
6774 -- If the view of the component's type is incomplete or private
6775 -- with unknown discriminants, then the constraint must be applied
6776 -- to the full type.
6778 if Has_Unknown_Discriminants (Btyp)
6779 and then Present (Underlying_Type (Btyp))
6781 Btyp := Underlying_Type (Btyp);
6785 Make_Subtype_Indication (Loc,
6786 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
6787 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
6789 Def_Id := Create_Itype (Ekind (T), Related_Node);
6792 Make_Subtype_Declaration (Loc,
6793 Defining_Identifier => Def_Id,
6794 Subtype_Indication => Indic);
6795 Set_Parent (Subtyp_Decl, Parent (Related_Node));
6797 -- Itypes must be analyzed with checks off (see itypes.ads).
6799 Analyze (Subtyp_Decl, Suppress => All_Checks);
6808 function Get_Value (Discrim : Entity_Id) return Node_Id is
6809 D : Entity_Id := First_Discriminant (Typ);
6810 E : Elmt_Id := First_Elmt (Constraints);
6813 while Present (D) loop
6815 -- If we are constraining the subtype of a derived tagged type,
6816 -- recover the discriminant of the parent, which appears in
6817 -- the constraint of an inherited component.
6819 if D = Entity (Discrim)
6820 or else Corresponding_Discriminant (D) = Entity (Discrim)
6825 Next_Discriminant (D);
6829 -- Something is wrong if we did not find the value
6831 raise Program_Error;
6834 ---------------------
6835 -- Is_Discriminant --
6836 ---------------------
6838 function Is_Discriminant (Expr : Node_Id) return Boolean is
6839 Discrim_Scope : Entity_Id;
6842 if Denotes_Discriminant (Expr) then
6843 Discrim_Scope := Scope (Entity (Expr));
6845 -- Either we have a reference to one of Typ's discriminants,
6847 pragma Assert (Discrim_Scope = Typ
6849 -- or to the discriminants of the parent type, in the case
6850 -- of a derivation of a tagged type with variants.
6852 or else Discrim_Scope = Etype (Typ)
6853 or else Full_View (Discrim_Scope) = Etype (Typ)
6855 -- or same as above for the case where the discriminants
6856 -- were declared in Typ's private view.
6858 or else (Is_Private_Type (Discrim_Scope)
6859 and then Chars (Discrim_Scope) = Chars (Typ))
6861 -- or else we are deriving from the full view and the
6862 -- discriminant is declared in the private entity.
6864 or else (Is_Private_Type (Typ)
6865 and then Chars (Discrim_Scope) = Chars (Typ))
6867 -- or we have a class-wide type, in which case make sure the
6868 -- discriminant found belongs to the root type.
6870 or else (Is_Class_Wide_Type (Typ)
6871 and then Etype (Typ) = Discrim_Scope));
6876 -- In all other cases we have something wrong.
6879 end Is_Discriminant;
6881 -- Start of processing for Constrain_Component_Type
6884 if Is_Array_Type (Compon_Type) then
6885 return Build_Constrained_Array_Type (Compon_Type);
6887 elsif Has_Discriminants (Compon_Type) then
6888 return Build_Constrained_Discriminated_Type (Compon_Type);
6890 elsif Is_Access_Type (Compon_Type) then
6891 return Build_Constrained_Access_Type (Compon_Type);
6895 end Constrain_Component_Type;
6897 --------------------------
6898 -- Constrain_Concurrent --
6899 --------------------------
6901 -- For concurrent types, the associated record value type carries the same
6902 -- discriminants, so when we constrain a concurrent type, we must constrain
6903 -- the value type as well.
6905 procedure Constrain_Concurrent
6906 (Def_Id : in out Entity_Id;
6908 Related_Nod : Node_Id;
6909 Related_Id : Entity_Id;
6912 T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
6916 if Ekind (T_Ent) in Access_Kind then
6917 T_Ent := Designated_Type (T_Ent);
6920 T_Val := Corresponding_Record_Type (T_Ent);
6922 if Present (T_Val) then
6925 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6928 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
6930 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
6931 Set_Corresponding_Record_Type (Def_Id,
6932 Constrain_Corresponding_Record
6933 (Def_Id, T_Val, Related_Nod, Related_Id));
6936 -- If there is no associated record, expansion is disabled and this
6937 -- is a generic context. Create a subtype in any case, so that
6938 -- semantic analysis can proceed.
6941 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
6944 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
6946 end Constrain_Concurrent;
6948 ------------------------------------
6949 -- Constrain_Corresponding_Record --
6950 ------------------------------------
6952 function Constrain_Corresponding_Record
6953 (Prot_Subt : Entity_Id;
6954 Corr_Rec : Entity_Id;
6955 Related_Nod : Node_Id;
6956 Related_Id : Entity_Id)
6959 T_Sub : constant Entity_Id
6960 := Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
6963 Set_Etype (T_Sub, Corr_Rec);
6964 Init_Size_Align (T_Sub);
6965 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
6966 Set_Is_Constrained (T_Sub, True);
6967 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
6968 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
6970 Conditional_Delay (T_Sub, Corr_Rec);
6972 if Has_Discriminants (Prot_Subt) then -- False only if errors.
6973 Set_Discriminant_Constraint (T_Sub,
6974 Discriminant_Constraint (Prot_Subt));
6975 Set_Girder_Constraint_From_Discriminant_Constraint (T_Sub);
6976 Create_Constrained_Components (T_Sub, Related_Nod, Corr_Rec,
6977 Discriminant_Constraint (T_Sub));
6980 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
6983 end Constrain_Corresponding_Record;
6985 -----------------------
6986 -- Constrain_Decimal --
6987 -----------------------
6989 procedure Constrain_Decimal
6992 Related_Nod : Node_Id)
6994 T : constant Entity_Id := Entity (Subtype_Mark (S));
6995 C : constant Node_Id := Constraint (S);
6996 Loc : constant Source_Ptr := Sloc (C);
6997 Range_Expr : Node_Id;
6998 Digits_Expr : Node_Id;
7003 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
7005 if Nkind (C) = N_Range_Constraint then
7006 Range_Expr := Range_Expression (C);
7007 Digits_Val := Digits_Value (T);
7010 pragma Assert (Nkind (C) = N_Digits_Constraint);
7011 Digits_Expr := Digits_Expression (C);
7012 Analyze_And_Resolve (Digits_Expr, Any_Integer);
7014 Check_Digits_Expression (Digits_Expr);
7015 Digits_Val := Expr_Value (Digits_Expr);
7017 if Digits_Val > Digits_Value (T) then
7019 ("digits expression is incompatible with subtype", C);
7020 Digits_Val := Digits_Value (T);
7023 if Present (Range_Constraint (C)) then
7024 Range_Expr := Range_Expression (Range_Constraint (C));
7026 Range_Expr := Empty;
7030 Set_Etype (Def_Id, Base_Type (T));
7031 Set_Size_Info (Def_Id, (T));
7032 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7033 Set_Delta_Value (Def_Id, Delta_Value (T));
7034 Set_Scale_Value (Def_Id, Scale_Value (T));
7035 Set_Small_Value (Def_Id, Small_Value (T));
7036 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
7037 Set_Digits_Value (Def_Id, Digits_Val);
7039 -- Manufacture range from given digits value if no range present
7041 if No (Range_Expr) then
7042 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
7046 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
7048 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
7052 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T, Related_Nod);
7053 Set_Discrete_RM_Size (Def_Id);
7055 -- Unconditionally delay the freeze, since we cannot set size
7056 -- information in all cases correctly until the freeze point.
7058 Set_Has_Delayed_Freeze (Def_Id);
7059 end Constrain_Decimal;
7061 ----------------------------------
7062 -- Constrain_Discriminated_Type --
7063 ----------------------------------
7065 procedure Constrain_Discriminated_Type
7066 (Def_Id : Entity_Id;
7068 Related_Nod : Node_Id;
7069 For_Access : Boolean := False)
7073 Elist : Elist_Id := New_Elmt_List;
7075 procedure Fixup_Bad_Constraint;
7076 -- This is called after finding a bad constraint, and after having
7077 -- posted an appropriate error message. The mission is to leave the
7078 -- entity T in as reasonable state as possible!
7080 procedure Fixup_Bad_Constraint is
7082 -- Set a reasonable Ekind for the entity. For an incomplete type,
7083 -- we can't do much, but for other types, we can set the proper
7084 -- corresponding subtype kind.
7086 if Ekind (T) = E_Incomplete_Type then
7087 Set_Ekind (Def_Id, Ekind (T));
7089 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
7092 Set_Etype (Def_Id, Any_Type);
7093 Set_Error_Posted (Def_Id);
7094 end Fixup_Bad_Constraint;
7096 -- Start of processing for Constrain_Discriminated_Type
7099 C := Constraint (S);
7101 -- A discriminant constraint is only allowed in a subtype indication,
7102 -- after a subtype mark. This subtype mark must denote either a type
7103 -- with discriminants, or an access type whose designated type is a
7104 -- type with discriminants. A discriminant constraint specifies the
7105 -- values of these discriminants (RM 3.7.2(5)).
7107 T := Base_Type (Entity (Subtype_Mark (S)));
7109 if Ekind (T) in Access_Kind then
7110 T := Designated_Type (T);
7113 if not Has_Discriminants (T) then
7114 Error_Msg_N ("invalid constraint: type has no discriminant", C);
7115 Fixup_Bad_Constraint;
7118 elsif Is_Constrained (Entity (Subtype_Mark (S))) then
7119 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
7120 Fixup_Bad_Constraint;
7124 -- T may be an unconstrained subtype (e.g. a generic actual).
7125 -- Constraint applies to the base type.
7129 Elist := Build_Discriminant_Constraints (T, S);
7131 -- If the list returned was empty we had an error in building the
7132 -- discriminant constraint. We have also already signalled an error
7133 -- in the incomplete type case
7135 if Is_Empty_Elmt_List (Elist) then
7136 Fixup_Bad_Constraint;
7140 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
7141 end Constrain_Discriminated_Type;
7143 ---------------------------
7144 -- Constrain_Enumeration --
7145 ---------------------------
7147 procedure Constrain_Enumeration
7150 Related_Nod : Node_Id)
7152 T : constant Entity_Id := Entity (Subtype_Mark (S));
7153 C : constant Node_Id := Constraint (S);
7156 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7158 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
7160 Set_Etype (Def_Id, Base_Type (T));
7161 Set_Size_Info (Def_Id, (T));
7162 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7163 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7165 Set_Scalar_Range_For_Subtype
7166 (Def_Id, Range_Expression (C), T, Related_Nod);
7168 Set_Discrete_RM_Size (Def_Id);
7170 end Constrain_Enumeration;
7172 ----------------------
7173 -- Constrain_Float --
7174 ----------------------
7176 procedure Constrain_Float
7179 Related_Nod : Node_Id)
7181 T : constant Entity_Id := Entity (Subtype_Mark (S));
7187 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
7189 Set_Etype (Def_Id, Base_Type (T));
7190 Set_Size_Info (Def_Id, (T));
7191 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7193 -- Process the constraint
7195 C := Constraint (S);
7197 -- Digits constraint present
7199 if Nkind (C) = N_Digits_Constraint then
7200 D := Digits_Expression (C);
7201 Analyze_And_Resolve (D, Any_Integer);
7202 Check_Digits_Expression (D);
7203 Set_Digits_Value (Def_Id, Expr_Value (D));
7205 -- Check that digits value is in range. Obviously we can do this
7206 -- at compile time, but it is strictly a runtime check, and of
7207 -- course there is an ACVC test that checks this!
7209 if Digits_Value (Def_Id) > Digits_Value (T) then
7210 Error_Msg_Uint_1 := Digits_Value (T);
7211 Error_Msg_N ("?digits value is too large, maximum is ^", D);
7212 Rais := Make_Raise_Constraint_Error (Sloc (D));
7213 Insert_Action (Declaration_Node (Def_Id), Rais);
7216 C := Range_Constraint (C);
7218 -- No digits constraint present
7221 Set_Digits_Value (Def_Id, Digits_Value (T));
7224 -- Range constraint present
7226 if Nkind (C) = N_Range_Constraint then
7227 Set_Scalar_Range_For_Subtype
7228 (Def_Id, Range_Expression (C), T, Related_Nod);
7230 -- No range constraint present
7233 pragma Assert (No (C));
7234 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7237 Set_Is_Constrained (Def_Id);
7238 end Constrain_Float;
7240 ---------------------
7241 -- Constrain_Index --
7242 ---------------------
7244 procedure Constrain_Index
7247 Related_Nod : Node_Id;
7248 Related_Id : Entity_Id;
7254 Checks_Off : Boolean := False;
7255 T : constant Entity_Id := Etype (Index);
7258 if Nkind (S) = N_Range
7259 or else Nkind (S) = N_Attribute_Reference
7261 -- A Range attribute will transformed into N_Range by Resolve.
7267 -- ??? Why on earth do we turn checks of in this very specific case ?
7269 -- From the revision history: (Constrain_Index): Call
7270 -- Process_Range_Expr_In_Decl with range checking off for range
7271 -- bounds that are attributes. This avoids some horrible
7272 -- constraint error checks.
7274 if Nkind (R) = N_Range
7275 and then Nkind (Low_Bound (R)) = N_Attribute_Reference
7276 and then Nkind (High_Bound (R)) = N_Attribute_Reference
7281 Process_Range_Expr_In_Decl
7282 (R, T, Related_Nod, Empty_List, Checks_Off);
7284 if not Error_Posted (S)
7286 (Nkind (S) /= N_Range
7287 or else Base_Type (T) /= Base_Type (Etype (Low_Bound (S)))
7288 or else Base_Type (T) /= Base_Type (Etype (High_Bound (S))))
7290 if Base_Type (T) /= Any_Type
7291 and then Etype (Low_Bound (S)) /= Any_Type
7292 and then Etype (High_Bound (S)) /= Any_Type
7294 Error_Msg_N ("range expected", S);
7298 elsif Nkind (S) = N_Subtype_Indication then
7299 -- the parser has verified that this is a discrete indication.
7301 Resolve_Discrete_Subtype_Indication (S, T);
7302 R := Range_Expression (Constraint (S));
7304 elsif Nkind (S) = N_Discriminant_Association then
7306 -- syntactically valid in subtype indication.
7308 Error_Msg_N ("invalid index constraint", S);
7309 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7312 -- Subtype_Mark case, no anonymous subtypes to construct
7317 if Is_Entity_Name (S) then
7319 if not Is_Type (Entity (S)) then
7320 Error_Msg_N ("expect subtype mark for index constraint", S);
7322 elsif Base_Type (Entity (S)) /= Base_Type (T) then
7323 Wrong_Type (S, Base_Type (T));
7329 Error_Msg_N ("invalid index constraint", S);
7330 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
7336 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
7338 Set_Etype (Def_Id, Base_Type (T));
7340 if Is_Modular_Integer_Type (T) then
7341 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7343 elsif Is_Integer_Type (T) then
7344 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7347 Set_Ekind (Def_Id, E_Enumeration_Subtype);
7348 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
7351 Set_Size_Info (Def_Id, (T));
7352 Set_RM_Size (Def_Id, RM_Size (T));
7353 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7355 -- ??? ??? is R always initialized, not at all obvious why?
7357 Set_Scalar_Range (Def_Id, R);
7359 Set_Etype (S, Def_Id);
7360 Set_Discrete_RM_Size (Def_Id);
7361 end Constrain_Index;
7363 -----------------------
7364 -- Constrain_Integer --
7365 -----------------------
7367 procedure Constrain_Integer
7370 Related_Nod : Node_Id)
7372 T : constant Entity_Id := Entity (Subtype_Mark (S));
7373 C : constant Node_Id := Constraint (S);
7376 Set_Scalar_Range_For_Subtype
7377 (Def_Id, Range_Expression (C), T, Related_Nod);
7379 if Is_Modular_Integer_Type (T) then
7380 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
7382 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
7385 Set_Etype (Def_Id, Base_Type (T));
7386 Set_Size_Info (Def_Id, (T));
7387 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7388 Set_Discrete_RM_Size (Def_Id);
7390 end Constrain_Integer;
7392 ------------------------------
7393 -- Constrain_Ordinary_Fixed --
7394 ------------------------------
7396 procedure Constrain_Ordinary_Fixed
7399 Related_Nod : Node_Id)
7401 T : constant Entity_Id := Entity (Subtype_Mark (S));
7407 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
7408 Set_Etype (Def_Id, Base_Type (T));
7409 Set_Size_Info (Def_Id, (T));
7410 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
7411 Set_Small_Value (Def_Id, Small_Value (T));
7413 -- Process the constraint
7415 C := Constraint (S);
7417 -- Delta constraint present
7419 if Nkind (C) = N_Delta_Constraint then
7420 D := Delta_Expression (C);
7421 Analyze_And_Resolve (D, Any_Real);
7422 Check_Delta_Expression (D);
7423 Set_Delta_Value (Def_Id, Expr_Value_R (D));
7425 -- Check that delta value is in range. Obviously we can do this
7426 -- at compile time, but it is strictly a runtime check, and of
7427 -- course there is an ACVC test that checks this!
7429 if Delta_Value (Def_Id) < Delta_Value (T) then
7430 Error_Msg_N ("?delta value is too small", D);
7431 Rais := Make_Raise_Constraint_Error (Sloc (D));
7432 Insert_Action (Declaration_Node (Def_Id), Rais);
7435 C := Range_Constraint (C);
7437 -- No delta constraint present
7440 Set_Delta_Value (Def_Id, Delta_Value (T));
7443 -- Range constraint present
7445 if Nkind (C) = N_Range_Constraint then
7446 Set_Scalar_Range_For_Subtype
7447 (Def_Id, Range_Expression (C), T, Related_Nod);
7449 -- No range constraint present
7452 pragma Assert (No (C));
7453 Set_Scalar_Range (Def_Id, Scalar_Range (T));
7457 Set_Discrete_RM_Size (Def_Id);
7459 -- Unconditionally delay the freeze, since we cannot set size
7460 -- information in all cases correctly until the freeze point.
7462 Set_Has_Delayed_Freeze (Def_Id);
7463 end Constrain_Ordinary_Fixed;
7465 ---------------------------
7466 -- Convert_Scalar_Bounds --
7467 ---------------------------
7469 procedure Convert_Scalar_Bounds
7471 Parent_Type : Entity_Id;
7472 Derived_Type : Entity_Id;
7475 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
7482 Lo := Build_Scalar_Bound
7483 (Type_Low_Bound (Derived_Type),
7484 Parent_Type, Implicit_Base, Loc);
7486 Hi := Build_Scalar_Bound
7487 (Type_High_Bound (Derived_Type),
7488 Parent_Type, Implicit_Base, Loc);
7495 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
7497 Set_Parent (Rng, N);
7498 Set_Scalar_Range (Derived_Type, Rng);
7500 -- Analyze the bounds
7502 Analyze_And_Resolve (Lo, Implicit_Base);
7503 Analyze_And_Resolve (Hi, Implicit_Base);
7505 -- Analyze the range itself, except that we do not analyze it if
7506 -- the bounds are real literals, and we have a fixed-point type.
7507 -- The reason for this is that we delay setting the bounds in this
7508 -- case till we know the final Small and Size values (see circuit
7509 -- in Freeze.Freeze_Fixed_Point_Type for further details).
7511 if Is_Fixed_Point_Type (Parent_Type)
7512 and then Nkind (Lo) = N_Real_Literal
7513 and then Nkind (Hi) = N_Real_Literal
7517 -- Here we do the analysis of the range.
7519 -- Note: we do this manually, since if we do a normal Analyze and
7520 -- Resolve call, there are problems with the conversions used for
7521 -- the derived type range.
7524 Set_Etype (Rng, Implicit_Base);
7525 Set_Analyzed (Rng, True);
7527 end Convert_Scalar_Bounds;
7533 procedure Copy_And_Swap (Privat, Full : Entity_Id) is
7535 -- Initialize new full declaration entity by copying the pertinent
7536 -- fields of the corresponding private declaration entity.
7538 Copy_Private_To_Full (Privat, Full);
7540 -- Swap the two entities. Now Privat is the full type entity and
7541 -- Full is the private one. They will be swapped back at the end
7542 -- of the private part. This swapping ensures that the entity that
7543 -- is visible in the private part is the full declaration.
7545 Exchange_Entities (Privat, Full);
7546 Append_Entity (Full, Scope (Full));
7549 -------------------------------------
7550 -- Copy_Array_Base_Type_Attributes --
7551 -------------------------------------
7553 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
7555 Set_Component_Alignment (T1, Component_Alignment (T2));
7556 Set_Component_Type (T1, Component_Type (T2));
7557 Set_Component_Size (T1, Component_Size (T2));
7558 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
7559 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
7560 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
7561 Set_Has_Task (T1, Has_Task (T2));
7562 Set_Is_Packed (T1, Is_Packed (T2));
7563 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
7564 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
7565 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
7566 end Copy_Array_Base_Type_Attributes;
7568 -----------------------------------
7569 -- Copy_Array_Subtype_Attributes --
7570 -----------------------------------
7572 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
7574 Set_Size_Info (T1, T2);
7576 Set_First_Index (T1, First_Index (T2));
7577 Set_Is_Aliased (T1, Is_Aliased (T2));
7578 Set_Is_Atomic (T1, Is_Atomic (T2));
7579 Set_Is_Volatile (T1, Is_Volatile (T2));
7580 Set_Is_Constrained (T1, Is_Constrained (T2));
7581 Set_Depends_On_Private (T1, Has_Private_Component (T2));
7582 Set_First_Rep_Item (T1, First_Rep_Item (T2));
7583 Set_Convention (T1, Convention (T2));
7584 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
7585 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
7586 end Copy_Array_Subtype_Attributes;
7588 --------------------------
7589 -- Copy_Private_To_Full --
7590 --------------------------
7592 procedure Copy_Private_To_Full (Priv, Full : Entity_Id) is
7594 -- We temporarily set Ekind to a value appropriate for a type to
7595 -- avoid assert failures in Einfo from checking for setting type
7596 -- attributes on something that is not a type. Ekind (Priv) is an
7597 -- appropriate choice, since it allowed the attributes to be set
7598 -- in the first place. This Ekind value will be modified later.
7600 Set_Ekind (Full, Ekind (Priv));
7602 -- Also set Etype temporarily to Any_Type, again, in the absence
7603 -- of errors, it will be properly reset, and if there are errors,
7604 -- then we want a value of Any_Type to remain.
7606 Set_Etype (Full, Any_Type);
7608 -- Now start copying attributes
7610 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
7612 if Has_Discriminants (Full) then
7613 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
7614 Set_Girder_Constraint (Full, Girder_Constraint (Priv));
7617 Set_Homonym (Full, Homonym (Priv));
7618 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
7619 Set_Is_Public (Full, Is_Public (Priv));
7620 Set_Is_Pure (Full, Is_Pure (Priv));
7621 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
7623 Conditional_Delay (Full, Priv);
7625 if Is_Tagged_Type (Full) then
7626 Set_Primitive_Operations (Full, Primitive_Operations (Priv));
7628 if Priv = Base_Type (Priv) then
7629 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
7633 Set_Is_Volatile (Full, Is_Volatile (Priv));
7634 Set_Scope (Full, Scope (Priv));
7635 Set_Next_Entity (Full, Next_Entity (Priv));
7636 Set_First_Entity (Full, First_Entity (Priv));
7637 Set_Last_Entity (Full, Last_Entity (Priv));
7639 -- If access types have been recorded for later handling, keep them
7640 -- in the full view so that they get handled when the full view freeze
7641 -- node is expanded.
7643 if Present (Freeze_Node (Priv))
7644 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
7646 Ensure_Freeze_Node (Full);
7647 Set_Access_Types_To_Process (Freeze_Node (Full),
7648 Access_Types_To_Process (Freeze_Node (Priv)));
7650 end Copy_Private_To_Full;
7652 -----------------------------------
7653 -- Create_Constrained_Components --
7654 -----------------------------------
7656 procedure Create_Constrained_Components
7658 Decl_Node : Node_Id;
7660 Constraints : Elist_Id)
7662 Loc : constant Source_Ptr := Sloc (Subt);
7663 Assoc_List : List_Id := New_List;
7664 Comp_List : Elist_Id := New_Elmt_List;
7665 Discr_Val : Elmt_Id;
7669 Is_Static : Boolean := True;
7670 Parent_Type : constant Entity_Id := Etype (Typ);
7672 procedure Collect_Fixed_Components (Typ : Entity_Id);
7673 -- Collect components of parent type that do not appear in a variant
7676 procedure Create_All_Components;
7677 -- Iterate over Comp_List to create the components of the subtype.
7679 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
7680 -- Creates a new component from Old_Compon, coppying all the fields from
7681 -- it, including its Etype, inserts the new component in the Subt entity
7682 -- chain and returns the new component.
7684 function Is_Variant_Record (T : Entity_Id) return Boolean;
7685 -- If true, and discriminants are static, collect only components from
7686 -- variants selected by discriminant values.
7688 ------------------------------
7689 -- Collect_Fixed_Components --
7690 ------------------------------
7692 procedure Collect_Fixed_Components (Typ : Entity_Id) is
7694 -- Build association list for discriminants, and find components of
7695 -- the variant part selected by the values of the discriminants.
7697 Old_C := First_Discriminant (Typ);
7698 Discr_Val := First_Elmt (Constraints);
7700 while Present (Old_C) loop
7701 Append_To (Assoc_List,
7702 Make_Component_Association (Loc,
7703 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
7704 Expression => New_Copy (Node (Discr_Val))));
7706 Next_Elmt (Discr_Val);
7707 Next_Discriminant (Old_C);
7710 -- The tag, and the possible parent and controller components
7711 -- are unconditionally in the subtype.
7713 if Is_Tagged_Type (Typ)
7714 or else Has_Controlled_Component (Typ)
7716 Old_C := First_Component (Typ);
7718 while Present (Old_C) loop
7719 if Chars ((Old_C)) = Name_uTag
7720 or else Chars ((Old_C)) = Name_uParent
7721 or else Chars ((Old_C)) = Name_uController
7723 Append_Elmt (Old_C, Comp_List);
7726 Next_Component (Old_C);
7729 end Collect_Fixed_Components;
7731 ---------------------------
7732 -- Create_All_Components --
7733 ---------------------------
7735 procedure Create_All_Components is
7739 Comp := First_Elmt (Comp_List);
7741 while Present (Comp) loop
7742 Old_C := Node (Comp);
7743 New_C := Create_Component (Old_C);
7747 Constrain_Component_Type
7748 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7749 Set_Is_Public (New_C, Is_Public (Subt));
7753 end Create_All_Components;
7755 ----------------------
7756 -- Create_Component --
7757 ----------------------
7759 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
7760 New_Compon : Entity_Id := New_Copy (Old_Compon);
7763 -- Set the parent so we have a proper link for freezing etc. This
7764 -- is not a real parent pointer, since of course our parent does
7765 -- not own up to us and reference us, we are an illegitimate
7766 -- child of the original parent!
7768 Set_Parent (New_Compon, Parent (Old_Compon));
7770 -- We do not want this node marked as Comes_From_Source, since
7771 -- otherwise it would get first class status and a separate
7772 -- cross-reference line would be generated. Illegitimate
7773 -- children do not rate such recognition.
7775 Set_Comes_From_Source (New_Compon, False);
7777 -- But it is a real entity, and a birth certificate must be
7778 -- properly registered by entering it into the entity list.
7780 Enter_Name (New_Compon);
7782 end Create_Component;
7784 -----------------------
7785 -- Is_Variant_Record --
7786 -----------------------
7788 function Is_Variant_Record (T : Entity_Id) return Boolean is
7790 return Nkind (Parent (T)) = N_Full_Type_Declaration
7791 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
7792 and then Present (Component_List (Type_Definition (Parent (T))))
7794 Variant_Part (Component_List (Type_Definition (Parent (T)))));
7795 end Is_Variant_Record;
7797 -- Start of processing for Create_Constrained_Components
7800 pragma Assert (Subt /= Base_Type (Subt));
7801 pragma Assert (Typ = Base_Type (Typ));
7803 Set_First_Entity (Subt, Empty);
7804 Set_Last_Entity (Subt, Empty);
7806 -- Check whether constraint is fully static, in which case we can
7807 -- optimize the list of components.
7809 Discr_Val := First_Elmt (Constraints);
7811 while Present (Discr_Val) loop
7813 if not Is_OK_Static_Expression (Node (Discr_Val)) then
7818 Next_Elmt (Discr_Val);
7823 -- Inherit the discriminants of the parent type.
7825 Old_C := First_Discriminant (Typ);
7827 while Present (Old_C) loop
7828 New_C := Create_Component (Old_C);
7829 Set_Is_Public (New_C, Is_Public (Subt));
7830 Next_Discriminant (Old_C);
7834 and then Is_Variant_Record (Typ)
7836 Collect_Fixed_Components (Typ);
7840 Component_List (Type_Definition (Parent (Typ))),
7841 Governed_By => Assoc_List,
7843 Report_Errors => Errors);
7844 pragma Assert (not Errors);
7846 Create_All_Components;
7848 -- If the subtype declaration is created for a tagged type derivation
7849 -- with constraints, we retrieve the record definition of the parent
7850 -- type to select the components of the proper variant.
7853 and then Is_Tagged_Type (Typ)
7854 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
7856 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
7857 and then Is_Variant_Record (Parent_Type)
7859 Collect_Fixed_Components (Typ);
7863 Component_List (Type_Definition (Parent (Parent_Type))),
7864 Governed_By => Assoc_List,
7866 Report_Errors => Errors);
7867 pragma Assert (not Errors);
7869 -- If the tagged derivation has a type extension, collect all the
7870 -- new components therein.
7873 Record_Extension_Part (Type_Definition (Parent (Typ))))
7875 Old_C := First_Component (Typ);
7877 while Present (Old_C) loop
7878 if Original_Record_Component (Old_C) = Old_C
7879 and then Chars (Old_C) /= Name_uTag
7880 and then Chars (Old_C) /= Name_uParent
7881 and then Chars (Old_C) /= Name_uController
7883 Append_Elmt (Old_C, Comp_List);
7886 Next_Component (Old_C);
7890 Create_All_Components;
7893 -- If the discriminants are not static, or if this is a multi-level
7894 -- type extension, we have to include all the components of the
7897 Old_C := First_Component (Typ);
7899 while Present (Old_C) loop
7900 New_C := Create_Component (Old_C);
7904 Constrain_Component_Type
7905 (Etype (Old_C), Subt, Decl_Node, Typ, Constraints));
7906 Set_Is_Public (New_C, Is_Public (Subt));
7908 Next_Component (Old_C);
7913 end Create_Constrained_Components;
7915 ------------------------------------------
7916 -- Decimal_Fixed_Point_Type_Declaration --
7917 ------------------------------------------
7919 procedure Decimal_Fixed_Point_Type_Declaration
7923 Loc : constant Source_Ptr := Sloc (Def);
7924 Digs_Expr : constant Node_Id := Digits_Expression (Def);
7925 Delta_Expr : constant Node_Id := Delta_Expression (Def);
7926 Implicit_Base : Entity_Id;
7932 -- Start of processing for Decimal_Fixed_Point_Type_Declaration
7935 Check_Restriction (No_Fixed_Point, Def);
7937 -- Create implicit base type
7940 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
7941 Set_Etype (Implicit_Base, Implicit_Base);
7943 -- Analyze and process delta expression
7945 Analyze_And_Resolve (Delta_Expr, Universal_Real);
7947 Check_Delta_Expression (Delta_Expr);
7948 Delta_Val := Expr_Value_R (Delta_Expr);
7950 -- Check delta is power of 10, and determine scale value from it
7953 Val : Ureal := Delta_Val;
7956 Scale_Val := Uint_0;
7958 if Val < Ureal_1 then
7959 while Val < Ureal_1 loop
7960 Val := Val * Ureal_10;
7961 Scale_Val := Scale_Val + 1;
7964 if Scale_Val > 18 then
7965 Error_Msg_N ("scale exceeds maximum value of 18", Def);
7966 Scale_Val := UI_From_Int (+18);
7970 while Val > Ureal_1 loop
7971 Val := Val / Ureal_10;
7972 Scale_Val := Scale_Val - 1;
7975 if Scale_Val < -18 then
7976 Error_Msg_N ("scale is less than minimum value of -18", Def);
7977 Scale_Val := UI_From_Int (-18);
7981 if Val /= Ureal_1 then
7982 Error_Msg_N ("delta expression must be a power of 10", Def);
7983 Delta_Val := Ureal_10 ** (-Scale_Val);
7987 -- Set delta, scale and small (small = delta for decimal type)
7989 Set_Delta_Value (Implicit_Base, Delta_Val);
7990 Set_Scale_Value (Implicit_Base, Scale_Val);
7991 Set_Small_Value (Implicit_Base, Delta_Val);
7993 -- Analyze and process digits expression
7995 Analyze_And_Resolve (Digs_Expr, Any_Integer);
7996 Check_Digits_Expression (Digs_Expr);
7997 Digs_Val := Expr_Value (Digs_Expr);
7999 if Digs_Val > 18 then
8000 Digs_Val := UI_From_Int (+18);
8001 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
8004 Set_Digits_Value (Implicit_Base, Digs_Val);
8005 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
8007 -- Set range of base type from digits value for now. This will be
8008 -- expanded to represent the true underlying base range by Freeze.
8010 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
8012 -- Set size to zero for now, size will be set at freeze time. We have
8013 -- to do this for ordinary fixed-point, because the size depends on
8014 -- the specified small, and we might as well do the same for decimal
8017 Init_Size_Align (Implicit_Base);
8019 -- Complete entity for first subtype
8021 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
8022 Set_Etype (T, Implicit_Base);
8023 Set_Size_Info (T, Implicit_Base);
8024 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
8025 Set_Digits_Value (T, Digs_Val);
8026 Set_Delta_Value (T, Delta_Val);
8027 Set_Small_Value (T, Delta_Val);
8028 Set_Scale_Value (T, Scale_Val);
8029 Set_Is_Constrained (T);
8031 -- If there are bounds given in the declaration use them as the
8032 -- bounds of the first named subtype.
8034 if Present (Real_Range_Specification (Def)) then
8036 RRS : constant Node_Id := Real_Range_Specification (Def);
8037 Low : constant Node_Id := Low_Bound (RRS);
8038 High : constant Node_Id := High_Bound (RRS);
8043 Analyze_And_Resolve (Low, Any_Real);
8044 Analyze_And_Resolve (High, Any_Real);
8045 Check_Real_Bound (Low);
8046 Check_Real_Bound (High);
8047 Low_Val := Expr_Value_R (Low);
8048 High_Val := Expr_Value_R (High);
8050 if Low_Val < (-Bound_Val) then
8052 ("range low bound too small for digits value", Low);
8053 Low_Val := -Bound_Val;
8056 if High_Val > Bound_Val then
8058 ("range high bound too large for digits value", High);
8059 High_Val := Bound_Val;
8062 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
8065 -- If no explicit range, use range that corresponds to given
8066 -- digits value. This will end up as the final range for the
8070 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
8073 end Decimal_Fixed_Point_Type_Declaration;
8075 -----------------------
8076 -- Derive_Subprogram --
8077 -----------------------
8079 procedure Derive_Subprogram
8080 (New_Subp : in out Entity_Id;
8081 Parent_Subp : Entity_Id;
8082 Derived_Type : Entity_Id;
8083 Parent_Type : Entity_Id;
8084 Actual_Subp : Entity_Id := Empty)
8087 New_Formal : Entity_Id;
8088 Same_Subt : constant Boolean :=
8089 Is_Scalar_Type (Parent_Type)
8090 and then Subtypes_Statically_Compatible (Parent_Type, Derived_Type);
8092 function Is_Private_Overriding return Boolean;
8093 -- If Subp is a private overriding of a visible operation, the in-
8094 -- herited operation derives from the overridden op (even though
8095 -- its body is the overriding one) and the inherited operation is
8096 -- visible now. See sem_disp to see the details of the handling of
8097 -- the overridden subprogram, which is removed from the list of
8098 -- primitive operations of the type.
8100 procedure Replace_Type (Id, New_Id : Entity_Id);
8101 -- When the type is an anonymous access type, create a new access type
8102 -- designating the derived type.
8104 ---------------------------
8105 -- Is_Private_Overriding --
8106 ---------------------------
8108 function Is_Private_Overriding return Boolean is
8112 Prev := Homonym (Parent_Subp);
8114 -- The visible operation that is overriden is a homonym of
8115 -- the parent subprogram. We scan the homonym chain to find
8116 -- the one whose alias is the subprogram we are deriving.
8118 while Present (Prev) loop
8119 if Is_Dispatching_Operation (Parent_Subp)
8120 and then Present (Prev)
8121 and then Ekind (Prev) = Ekind (Parent_Subp)
8122 and then Alias (Prev) = Parent_Subp
8123 and then Scope (Parent_Subp) = Scope (Prev)
8124 and then not Is_Hidden (Prev)
8129 Prev := Homonym (Prev);
8133 end Is_Private_Overriding;
8139 procedure Replace_Type (Id, New_Id : Entity_Id) is
8140 Acc_Type : Entity_Id;
8144 -- When the type is an anonymous access type, create a new access
8145 -- type designating the derived type. This itype must be elaborated
8146 -- at the point of the derivation, not on subsequent calls that may
8147 -- be out of the proper scope for Gigi, so we insert a reference to
8148 -- it after the derivation.
8150 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
8152 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
8155 if Ekind (Desig_Typ) = E_Record_Type_With_Private
8156 and then Present (Full_View (Desig_Typ))
8157 and then not Is_Private_Type (Parent_Type)
8159 Desig_Typ := Full_View (Desig_Typ);
8162 if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
8163 Acc_Type := New_Copy (Etype (Id));
8164 Set_Etype (Acc_Type, Acc_Type);
8165 Set_Scope (Acc_Type, New_Subp);
8167 -- Compute size of anonymous access type.
8169 if Is_Array_Type (Desig_Typ)
8170 and then not Is_Constrained (Desig_Typ)
8172 Init_Size (Acc_Type, 2 * System_Address_Size);
8174 Init_Size (Acc_Type, System_Address_Size);
8177 Init_Alignment (Acc_Type);
8179 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
8181 Set_Etype (New_Id, Acc_Type);
8182 Set_Scope (New_Id, New_Subp);
8184 -- Create a reference to it.
8186 IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
8187 Set_Itype (IR, Acc_Type);
8188 Insert_After (Parent (Derived_Type), IR);
8191 Set_Etype (New_Id, Etype (Id));
8194 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
8196 (Ekind (Etype (Id)) = E_Record_Type_With_Private
8197 and then Present (Full_View (Etype (Id)))
8198 and then Base_Type (Full_View (Etype (Id))) =
8199 Base_Type (Parent_Type))
8202 -- Constraint checks on formals are generated during expansion,
8203 -- based on the signature of the original subprogram. The bounds
8204 -- of the derived type are not relevant, and thus we can use
8205 -- the base type for the formals. However, the return type may be
8206 -- used in a context that requires that the proper static bounds
8207 -- be used (a case statement, for example) and for those cases
8208 -- we must use the derived type (first subtype), not its base.
8210 if Etype (Id) = Parent_Type
8213 Set_Etype (New_Id, Derived_Type);
8215 Set_Etype (New_Id, Base_Type (Derived_Type));
8219 Set_Etype (New_Id, Etype (Id));
8223 -- Start of processing for Derive_Subprogram
8227 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
8228 Set_Ekind (New_Subp, Ekind (Parent_Subp));
8230 -- Check whether the inherited subprogram is a private operation that
8231 -- should be inherited but not yet made visible. Such subprograms can
8232 -- become visible at a later point (e.g., the private part of a public
8233 -- child unit) via Declare_Inherited_Private_Subprograms. If the
8234 -- following predicate is true, then this is not such a private
8235 -- operation and the subprogram simply inherits the name of the parent
8236 -- subprogram. Note the special check for the names of controlled
8237 -- operations, which are currently exempted from being inherited with
8238 -- a hidden name because they must be findable for generation of
8239 -- implicit run-time calls.
8241 if not Is_Hidden (Parent_Subp)
8242 or else Is_Internal (Parent_Subp)
8243 or else Is_Private_Overriding
8244 or else Is_Internal_Name (Chars (Parent_Subp))
8245 or else Chars (Parent_Subp) = Name_Initialize
8246 or else Chars (Parent_Subp) = Name_Adjust
8247 or else Chars (Parent_Subp) = Name_Finalize
8249 Set_Chars (New_Subp, Chars (Parent_Subp));
8251 -- If parent is hidden, this can be a regular derivation if the
8252 -- parent is immediately visible in a non-instantiating context,
8253 -- or if we are in the private part of an instance. This test
8254 -- should still be refined ???
8256 -- The test for In_Instance_Not_Visible avoids inheriting the
8257 -- derived operation as a non-visible operation in cases where
8258 -- the parent subprogram might not be visible now, but was
8259 -- visible within the original generic, so it would be wrong
8260 -- to make the inherited subprogram non-visible now. (Not
8261 -- clear if this test is fully correct; are there any cases
8262 -- where we should declare the inherited operation as not
8263 -- visible to avoid it being overridden, e.g., when the
8264 -- parent type is a generic actual with private primitives ???)
8266 -- (they should be treated the same as other private inherited
8267 -- subprograms, but it's not clear how to do this cleanly). ???
8269 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
8270 and then Is_Immediately_Visible (Parent_Subp)
8271 and then not In_Instance)
8272 or else In_Instance_Not_Visible
8274 Set_Chars (New_Subp, Chars (Parent_Subp));
8276 -- The type is inheriting a private operation, so enter
8277 -- it with a special name so it can't be overridden.
8280 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
8283 Set_Parent (New_Subp, Parent (Derived_Type));
8284 Replace_Type (Parent_Subp, New_Subp);
8285 Conditional_Delay (New_Subp, Parent_Subp);
8287 Formal := First_Formal (Parent_Subp);
8288 while Present (Formal) loop
8289 New_Formal := New_Copy (Formal);
8291 -- Normally we do not go copying parents, but in the case of
8292 -- formals, we need to link up to the declaration (which is
8293 -- the parameter specification), and it is fine to link up to
8294 -- the original formal's parameter specification in this case.
8296 Set_Parent (New_Formal, Parent (Formal));
8298 Append_Entity (New_Formal, New_Subp);
8300 Replace_Type (Formal, New_Formal);
8301 Next_Formal (Formal);
8304 -- If this derivation corresponds to a tagged generic actual, then
8305 -- primitive operations rename those of the actual. Otherwise the
8306 -- primitive operations rename those of the parent type.
8308 if No (Actual_Subp) then
8309 Set_Alias (New_Subp, Parent_Subp);
8310 Set_Is_Intrinsic_Subprogram (New_Subp,
8311 Is_Intrinsic_Subprogram (Parent_Subp));
8314 Set_Alias (New_Subp, Actual_Subp);
8317 -- Derived subprograms of a tagged type must inherit the convention
8318 -- of the parent subprogram (a requirement of AI-117). Derived
8319 -- subprograms of untagged types simply get convention Ada by default.
8321 if Is_Tagged_Type (Derived_Type) then
8322 Set_Convention (New_Subp, Convention (Parent_Subp));
8325 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
8326 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
8328 if Ekind (Parent_Subp) = E_Procedure then
8329 Set_Is_Valued_Procedure
8330 (New_Subp, Is_Valued_Procedure (Parent_Subp));
8333 New_Overloaded_Entity (New_Subp, Derived_Type);
8335 -- Check for case of a derived subprogram for the instantiation
8336 -- of a formal derived tagged type, so mark the subprogram as
8337 -- dispatching and inherit the dispatching attributes of the
8338 -- parent subprogram. The derived subprogram is effectively a
8339 -- renaming of the actual subprogram, so it needs to have the
8340 -- same attributes as the actual.
8342 if Present (Actual_Subp)
8343 and then Is_Dispatching_Operation (Parent_Subp)
8345 Set_Is_Dispatching_Operation (New_Subp);
8346 if Present (DTC_Entity (Parent_Subp)) then
8347 Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
8348 Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
8352 -- Indicate that a derived subprogram does not require a body
8353 -- and that it does not require processing of default expressions.
8355 Set_Has_Completion (New_Subp);
8356 Set_Default_Expressions_Processed (New_Subp);
8358 -- A derived function with a controlling result is abstract.
8359 -- If the Derived_Type is a nonabstract formal generic derived
8360 -- type, then inherited operations are not abstract: check is
8361 -- done at instantiation time. If the derivation is for a generic
8362 -- actual, the function is not abstract unless the actual is.
8364 if Is_Generic_Type (Derived_Type)
8365 and then not Is_Abstract (Derived_Type)
8369 elsif Is_Abstract (Alias (New_Subp))
8370 or else (Is_Tagged_Type (Derived_Type)
8371 and then Etype (New_Subp) = Derived_Type
8372 and then No (Actual_Subp))
8374 Set_Is_Abstract (New_Subp);
8377 if Ekind (New_Subp) = E_Function then
8378 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
8380 end Derive_Subprogram;
8382 ------------------------
8383 -- Derive_Subprograms --
8384 ------------------------
8386 procedure Derive_Subprograms
8387 (Parent_Type : Entity_Id;
8388 Derived_Type : Entity_Id;
8389 Generic_Actual : Entity_Id := Empty)
8391 Op_List : Elist_Id := Collect_Primitive_Operations (Parent_Type);
8392 Act_List : Elist_Id;
8396 New_Subp : Entity_Id := Empty;
8397 Parent_Base : Entity_Id;
8400 if Ekind (Parent_Type) = E_Record_Type_With_Private
8401 and then Has_Discriminants (Parent_Type)
8402 and then Present (Full_View (Parent_Type))
8404 Parent_Base := Full_View (Parent_Type);
8406 Parent_Base := Parent_Type;
8409 Elmt := First_Elmt (Op_List);
8411 if Present (Generic_Actual) then
8412 Act_List := Collect_Primitive_Operations (Generic_Actual);
8413 Act_Elmt := First_Elmt (Act_List);
8415 Act_Elmt := No_Elmt;
8418 -- Literals are derived earlier in the process of building the
8419 -- derived type, and are skipped here.
8421 while Present (Elmt) loop
8422 Subp := Node (Elmt);
8424 if Ekind (Subp) /= E_Enumeration_Literal then
8425 if No (Generic_Actual) then
8427 (New_Subp, Subp, Derived_Type, Parent_Base);
8430 Derive_Subprogram (New_Subp, Subp,
8431 Derived_Type, Parent_Base, Node (Act_Elmt));
8432 Next_Elmt (Act_Elmt);
8438 end Derive_Subprograms;
8440 --------------------------------
8441 -- Derived_Standard_Character --
8442 --------------------------------
8444 procedure Derived_Standard_Character
8446 Parent_Type : Entity_Id;
8447 Derived_Type : Entity_Id)
8449 Loc : constant Source_Ptr := Sloc (N);
8450 Def : constant Node_Id := Type_Definition (N);
8451 Indic : constant Node_Id := Subtype_Indication (Def);
8452 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8453 Implicit_Base : constant Entity_Id :=
8455 (E_Enumeration_Type, N, Derived_Type, 'B');
8462 T := Process_Subtype (Indic, N);
8464 Set_Etype (Implicit_Base, Parent_Base);
8465 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
8466 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
8468 Set_Is_Character_Type (Implicit_Base, True);
8469 Set_Has_Delayed_Freeze (Implicit_Base);
8471 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
8472 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
8474 Set_Scalar_Range (Implicit_Base,
8479 Conditional_Delay (Derived_Type, Parent_Type);
8481 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
8482 Set_Etype (Derived_Type, Implicit_Base);
8483 Set_Size_Info (Derived_Type, Parent_Type);
8485 if Unknown_RM_Size (Derived_Type) then
8486 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8489 Set_Is_Character_Type (Derived_Type, True);
8491 if Nkind (Indic) /= N_Subtype_Indication then
8492 Set_Scalar_Range (Derived_Type, Scalar_Range (Implicit_Base));
8495 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
8497 -- Because the implicit base is used in the conversion of the bounds,
8498 -- we have to freeze it now. This is similar to what is done for
8499 -- numeric types, and it equally suspicious, but otherwise a non-
8500 -- static bound will have a reference to an unfrozen type, which is
8501 -- rejected by Gigi (???).
8503 Freeze_Before (N, Implicit_Base);
8505 end Derived_Standard_Character;
8507 ------------------------------
8508 -- Derived_Type_Declaration --
8509 ------------------------------
8511 procedure Derived_Type_Declaration
8514 Is_Completion : Boolean)
8516 Def : constant Node_Id := Type_Definition (N);
8517 Indic : constant Node_Id := Subtype_Indication (Def);
8518 Extension : constant Node_Id := Record_Extension_Part (Def);
8519 Parent_Type : Entity_Id;
8520 Parent_Scope : Entity_Id;
8524 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
8526 if Parent_Type = Any_Type
8527 or else Etype (Parent_Type) = Any_Type
8528 or else (Is_Class_Wide_Type (Parent_Type)
8529 and then Etype (Parent_Type) = T)
8531 -- If Parent_Type is undefined or illegal, make new type into
8532 -- a subtype of Any_Type, and set a few attributes to prevent
8533 -- cascaded errors. If this is a self-definition, emit error now.
8536 or else T = Etype (Parent_Type)
8538 Error_Msg_N ("type cannot be used in its own definition", Indic);
8541 Set_Ekind (T, Ekind (Parent_Type));
8542 Set_Etype (T, Any_Type);
8543 Set_Scalar_Range (T, Scalar_Range (Any_Type));
8545 if Is_Tagged_Type (T) then
8546 Set_Primitive_Operations (T, New_Elmt_List);
8550 elsif Is_Unchecked_Union (Parent_Type) then
8551 Error_Msg_N ("cannot derive from Unchecked_Union type", N);
8554 -- Only composite types other than array types are allowed to have
8557 if Present (Discriminant_Specifications (N))
8558 and then (Is_Elementary_Type (Parent_Type)
8559 or else Is_Array_Type (Parent_Type))
8560 and then not Error_Posted (N)
8563 ("elementary or array type cannot have discriminants",
8564 Defining_Identifier (First (Discriminant_Specifications (N))));
8565 Set_Has_Discriminants (T, False);
8568 -- In Ada 83, a derived type defined in a package specification cannot
8569 -- be used for further derivation until the end of its visible part.
8570 -- Note that derivation in the private part of the package is allowed.
8573 and then Is_Derived_Type (Parent_Type)
8574 and then In_Visible_Part (Scope (Parent_Type))
8576 if Ada_83 and then Comes_From_Source (Indic) then
8578 ("(Ada 83): premature use of type for derivation", Indic);
8582 -- Check for early use of incomplete or private type
8584 if Ekind (Parent_Type) = E_Void
8585 or else Ekind (Parent_Type) = E_Incomplete_Type
8587 Error_Msg_N ("premature derivation of incomplete type", Indic);
8590 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
8591 and then not Is_Generic_Type (Parent_Type)
8592 and then not Is_Generic_Type (Root_Type (Parent_Type))
8593 and then not Is_Generic_Actual_Type (Parent_Type))
8594 or else Has_Private_Component (Parent_Type)
8596 -- The ancestor type of a formal type can be incomplete, in which
8597 -- case only the operations of the partial view are available in
8598 -- the generic. Subsequent checks may be required when the full
8599 -- view is analyzed, to verify that derivation from a tagged type
8600 -- has an extension.
8602 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
8605 elsif No (Underlying_Type (Parent_Type))
8606 or else Has_Private_Component (Parent_Type)
8609 ("premature derivation of derived or private type", Indic);
8611 -- Flag the type itself as being in error, this prevents some
8612 -- nasty problems with people looking at the malformed type.
8614 Set_Error_Posted (T);
8616 -- Check that within the immediate scope of an untagged partial
8617 -- view it's illegal to derive from the partial view if the
8618 -- full view is tagged. (7.3(7))
8620 -- We verify that the Parent_Type is a partial view by checking
8621 -- that it is not a Full_Type_Declaration (i.e. a private type or
8622 -- private extension declaration), to distinguish a partial view
8623 -- from a derivation from a private type which also appears as
8626 elsif Present (Full_View (Parent_Type))
8627 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
8628 and then not Is_Tagged_Type (Parent_Type)
8629 and then Is_Tagged_Type (Full_View (Parent_Type))
8631 Parent_Scope := Scope (T);
8632 while Present (Parent_Scope)
8633 and then Parent_Scope /= Standard_Standard
8635 if Parent_Scope = Scope (Parent_Type) then
8637 ("premature derivation from type with tagged full view",
8641 Parent_Scope := Scope (Parent_Scope);
8646 -- Check that form of derivation is appropriate
8648 Taggd := Is_Tagged_Type (Parent_Type);
8650 -- Perhaps the parent type should be changed to the class-wide type's
8651 -- specific type in this case to prevent cascading errors ???
8653 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
8654 Error_Msg_N ("parent type must not be a class-wide type", Indic);
8658 if Present (Extension) and then not Taggd then
8660 ("type derived from untagged type cannot have extension", Indic);
8662 elsif No (Extension) and then Taggd then
8663 -- If this is within a private part (or body) of a generic
8664 -- instantiation then the derivation is allowed (the parent
8665 -- type can only appear tagged in this case if it's a generic
8666 -- actual type, since it would otherwise have been rejected
8667 -- in the analysis of the generic template).
8669 if not Is_Generic_Actual_Type (Parent_Type)
8670 or else In_Visible_Part (Scope (Parent_Type))
8673 ("type derived from tagged type must have extension", Indic);
8677 Build_Derived_Type (N, Parent_Type, T, Is_Completion);
8678 end Derived_Type_Declaration;
8680 ----------------------------------
8681 -- Enumeration_Type_Declaration --
8682 ----------------------------------
8684 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
8691 -- Create identifier node representing lower bound
8693 B_Node := New_Node (N_Identifier, Sloc (Def));
8694 L := First (Literals (Def));
8695 Set_Chars (B_Node, Chars (L));
8696 Set_Entity (B_Node, L);
8697 Set_Etype (B_Node, T);
8698 Set_Is_Static_Expression (B_Node, True);
8700 R_Node := New_Node (N_Range, Sloc (Def));
8701 Set_Low_Bound (R_Node, B_Node);
8703 Set_Ekind (T, E_Enumeration_Type);
8704 Set_First_Literal (T, L);
8706 Set_Is_Constrained (T);
8710 -- Loop through literals of enumeration type setting pos and rep values
8711 -- except that if the Ekind is already set, then it means that the
8712 -- literal was already constructed (case of a derived type declaration
8713 -- and we should not disturb the Pos and Rep values.
8715 while Present (L) loop
8716 if Ekind (L) /= E_Enumeration_Literal then
8717 Set_Ekind (L, E_Enumeration_Literal);
8718 Set_Enumeration_Pos (L, Ev);
8719 Set_Enumeration_Rep (L, Ev);
8720 Set_Is_Known_Valid (L, True);
8724 New_Overloaded_Entity (L);
8725 Generate_Definition (L);
8726 Set_Convention (L, Convention_Intrinsic);
8728 if Nkind (L) = N_Defining_Character_Literal then
8729 Set_Is_Character_Type (T, True);
8736 -- Now create a node representing upper bound
8738 B_Node := New_Node (N_Identifier, Sloc (Def));
8739 Set_Chars (B_Node, Chars (Last (Literals (Def))));
8740 Set_Entity (B_Node, Last (Literals (Def)));
8741 Set_Etype (B_Node, T);
8742 Set_Is_Static_Expression (B_Node, True);
8744 Set_High_Bound (R_Node, B_Node);
8745 Set_Scalar_Range (T, R_Node);
8746 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
8749 -- Set Discard_Names if configuration pragma setg, or if there is
8750 -- a parameterless pragma in the current declarative region
8752 if Global_Discard_Names
8753 or else Discard_Names (Scope (T))
8755 Set_Discard_Names (T);
8757 end Enumeration_Type_Declaration;
8759 --------------------------
8760 -- Expand_Others_Choice --
8761 --------------------------
8763 procedure Expand_Others_Choice
8764 (Case_Table : Choice_Table_Type;
8765 Others_Choice : Node_Id;
8766 Choice_Type : Entity_Id)
8769 Choice_List : List_Id := New_List;
8774 Loc : Source_Ptr := Sloc (Others_Choice);
8777 function Build_Choice (Value1, Value2 : Uint) return Node_Id;
8778 -- Builds a node representing the missing choices given by the
8779 -- Value1 and Value2. A N_Range node is built if there is more than
8780 -- one literal value missing. Otherwise a single N_Integer_Literal,
8781 -- N_Identifier or N_Character_Literal is built depending on what
8784 function Lit_Of (Value : Uint) return Node_Id;
8785 -- Returns the Node_Id for the enumeration literal corresponding to the
8786 -- position given by Value within the enumeration type Choice_Type.
8792 function Build_Choice (Value1, Value2 : Uint) return Node_Id is
8797 -- If there is only one choice value missing between Value1 and
8798 -- Value2, build an integer or enumeration literal to represent it.
8800 if (Value2 - Value1) = 0 then
8801 if Is_Integer_Type (Choice_Type) then
8802 Lit_Node := Make_Integer_Literal (Loc, Value1);
8803 Set_Etype (Lit_Node, Choice_Type);
8805 Lit_Node := Lit_Of (Value1);
8808 -- Otherwise is more that one choice value that is missing between
8809 -- Value1 and Value2, therefore build a N_Range node of either
8810 -- integer or enumeration literals.
8813 if Is_Integer_Type (Choice_Type) then
8814 Lo := Make_Integer_Literal (Loc, Value1);
8815 Set_Etype (Lo, Choice_Type);
8816 Hi := Make_Integer_Literal (Loc, Value2);
8817 Set_Etype (Hi, Choice_Type);
8826 Low_Bound => Lit_Of (Value1),
8827 High_Bound => Lit_Of (Value2));
8838 function Lit_Of (Value : Uint) return Node_Id is
8842 -- In the case where the literal is of type Character, there needs
8843 -- to be some special handling since there is no explicit chain
8844 -- of literals to search. Instead, a N_Character_Literal node
8845 -- is created with the appropriate Char_Code and Chars fields.
8847 if Root_Type (Choice_Type) = Standard_Character then
8848 Set_Character_Literal_Name (Char_Code (UI_To_Int (Value)));
8849 Lit := New_Node (N_Character_Literal, Loc);
8850 Set_Chars (Lit, Name_Find);
8851 Set_Char_Literal_Value (Lit, Char_Code (UI_To_Int (Value)));
8852 Set_Etype (Lit, Choice_Type);
8853 Set_Is_Static_Expression (Lit, True);
8856 -- Otherwise, iterate through the literals list of Choice_Type
8857 -- "Value" number of times until the desired literal is reached
8858 -- and then return an occurrence of it.
8861 Lit := First_Literal (Choice_Type);
8862 for J in 1 .. UI_To_Int (Value) loop
8866 return New_Occurrence_Of (Lit, Loc);
8870 -- Start of processing for Expand_Others_Choice
8873 if Case_Table'Length = 0 then
8875 -- Pathological case: only an others case is present.
8876 -- The others case covers the full range of the type.
8878 if Is_Static_Subtype (Choice_Type) then
8879 Choice := New_Occurrence_Of (Choice_Type, Loc);
8881 Choice := New_Occurrence_Of (Base_Type (Choice_Type), Loc);
8884 Set_Others_Discrete_Choices (Others_Choice, New_List (Choice));
8888 -- Establish the bound values for the variant depending upon whether
8889 -- the type of the discriminant name is static or not.
8891 if Is_OK_Static_Subtype (Choice_Type) then
8892 Exp_Lo := Type_Low_Bound (Choice_Type);
8893 Exp_Hi := Type_High_Bound (Choice_Type);
8895 Exp_Lo := Type_Low_Bound (Base_Type (Choice_Type));
8896 Exp_Hi := Type_High_Bound (Base_Type (Choice_Type));
8899 Lo := Expr_Value (Case_Table (Case_Table'First).Lo);
8900 Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8901 Previous_Hi := Expr_Value (Case_Table (Case_Table'First).Hi);
8903 -- Build the node for any missing choices that are smaller than any
8904 -- explicit choices given in the variant.
8906 if Expr_Value (Exp_Lo) < Lo then
8907 Append (Build_Choice (Expr_Value (Exp_Lo), Lo - 1), Choice_List);
8910 -- Build the nodes representing any missing choices that lie between
8911 -- the explicit ones given in the variant.
8913 for J in Case_Table'First + 1 .. Case_Table'Last loop
8914 Lo := Expr_Value (Case_Table (J).Lo);
8915 Hi := Expr_Value (Case_Table (J).Hi);
8917 if Lo /= (Previous_Hi + 1) then
8918 Append_To (Choice_List, Build_Choice (Previous_Hi + 1, Lo - 1));
8924 -- Build the node for any missing choices that are greater than any
8925 -- explicit choices given in the variant.
8927 if Expr_Value (Exp_Hi) > Hi then
8928 Append (Build_Choice (Hi + 1, Expr_Value (Exp_Hi)), Choice_List);
8931 Set_Others_Discrete_Choices (Others_Choice, Choice_List);
8932 end Expand_Others_Choice;
8934 ---------------------------------
8935 -- Expand_To_Girder_Constraint --
8936 ---------------------------------
8938 function Expand_To_Girder_Constraint
8940 Constraint : Elist_Id)
8943 Explicitly_Discriminated_Type : Entity_Id;
8944 Expansion : Elist_Id;
8945 Discriminant : Entity_Id;
8947 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
8948 -- Find the nearest type that actually specifies discriminants.
8950 ---------------------------------
8951 -- Type_With_Explicit_Discrims --
8952 ---------------------------------
8954 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
8955 Typ : constant E := Base_Type (Id);
8958 if Ekind (Typ) in Incomplete_Or_Private_Kind then
8959 if Present (Full_View (Typ)) then
8960 return Type_With_Explicit_Discrims (Full_View (Typ));
8964 if Has_Discriminants (Typ) then
8969 if Etype (Typ) = Typ then
8971 elsif Has_Discriminants (Typ) then
8974 return Type_With_Explicit_Discrims (Etype (Typ));
8977 end Type_With_Explicit_Discrims;
8979 -- Start of processing for Expand_To_Girder_Constraint
8983 or else Is_Empty_Elmt_List (Constraint)
8988 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
8990 if No (Explicitly_Discriminated_Type) then
8994 Expansion := New_Elmt_List;
8997 First_Girder_Discriminant (Explicitly_Discriminated_Type);
8999 while Present (Discriminant) loop
9002 Get_Discriminant_Value (
9003 Discriminant, Explicitly_Discriminated_Type, Constraint),
9006 Next_Girder_Discriminant (Discriminant);
9010 end Expand_To_Girder_Constraint;
9012 --------------------
9013 -- Find_Type_Name --
9014 --------------------
9016 function Find_Type_Name (N : Node_Id) return Entity_Id is
9017 Id : constant Entity_Id := Defining_Identifier (N);
9023 -- Find incomplete declaration, if some was given.
9025 Prev := Current_Entity_In_Scope (Id);
9027 if Present (Prev) then
9029 -- Previous declaration exists. Error if not incomplete/private case
9030 -- except if previous declaration is implicit, etc. Enter_Name will
9031 -- emit error if appropriate.
9033 Prev_Par := Parent (Prev);
9035 if not Is_Incomplete_Or_Private_Type (Prev) then
9039 elsif Nkind (N) /= N_Full_Type_Declaration
9040 and then Nkind (N) /= N_Task_Type_Declaration
9041 and then Nkind (N) /= N_Protected_Type_Declaration
9043 -- Completion must be a full type declarations (RM 7.3(4))
9045 Error_Msg_Sloc := Sloc (Prev);
9046 Error_Msg_NE ("invalid completion of }", Id, Prev);
9048 -- Set scope of Id to avoid cascaded errors. Entity is never
9049 -- examined again, except when saving globals in generics.
9051 Set_Scope (Id, Current_Scope);
9054 -- Case of full declaration of incomplete type
9056 elsif Ekind (Prev) = E_Incomplete_Type then
9058 -- Indicate that the incomplete declaration has a matching
9059 -- full declaration. The defining occurrence of the incomplete
9060 -- declaration remains the visible one, and the procedure
9061 -- Get_Full_View dereferences it whenever the type is used.
9063 if Present (Full_View (Prev)) then
9064 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9067 Set_Full_View (Prev, Id);
9068 Append_Entity (Id, Current_Scope);
9069 Set_Is_Public (Id, Is_Public (Prev));
9070 Set_Is_Internal (Id);
9073 -- Case of full declaration of private type
9076 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
9077 if Etype (Prev) /= Prev then
9079 -- Prev is a private subtype or a derived type, and needs
9082 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
9085 elsif Ekind (Prev) = E_Private_Type
9087 (Nkind (N) = N_Task_Type_Declaration
9088 or else Nkind (N) = N_Protected_Type_Declaration)
9091 ("completion of nonlimited type cannot be limited", N);
9094 elsif Nkind (N) /= N_Full_Type_Declaration
9095 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
9097 Error_Msg_N ("full view of private extension must be"
9098 & " an extension", N);
9100 elsif not (Abstract_Present (Parent (Prev)))
9101 and then Abstract_Present (Type_Definition (N))
9103 Error_Msg_N ("full view of non-abstract extension cannot"
9104 & " be abstract", N);
9107 if not In_Private_Part (Current_Scope) then
9109 ("declaration of full view must appear in private part", N);
9112 Copy_And_Swap (Prev, Id);
9113 Set_Full_View (Id, Prev);
9114 Set_Has_Private_Declaration (Prev);
9115 Set_Has_Private_Declaration (Id);
9119 -- Verify that full declaration conforms to incomplete one
9121 if Is_Incomplete_Or_Private_Type (Prev)
9122 and then Present (Discriminant_Specifications (Prev_Par))
9124 if Present (Discriminant_Specifications (N)) then
9125 if Ekind (Prev) = E_Incomplete_Type then
9126 Check_Discriminant_Conformance (N, Prev, Prev);
9128 Check_Discriminant_Conformance (N, Prev, Id);
9133 ("missing discriminants in full type declaration", N);
9135 -- To avoid cascaded errors on subsequent use, share the
9136 -- discriminants of the partial view.
9138 Set_Discriminant_Specifications (N,
9139 Discriminant_Specifications (Prev_Par));
9143 -- A prior untagged private type can have an associated
9144 -- class-wide type due to use of the class attribute,
9145 -- and in this case also the full type is required to
9149 and then (Is_Tagged_Type (Prev)
9150 or else Present (Class_Wide_Type (Prev)))
9152 -- The full declaration is either a tagged record or an
9153 -- extension otherwise this is an error
9155 if Nkind (Type_Definition (N)) = N_Record_Definition then
9156 if not Tagged_Present (Type_Definition (N)) then
9158 ("full declaration of } must be tagged", Prev, Id);
9159 Set_Is_Tagged_Type (Id);
9160 Set_Primitive_Operations (Id, New_Elmt_List);
9163 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
9164 if No (Record_Extension_Part (Type_Definition (N))) then
9166 "full declaration of } must be a record extension",
9168 Set_Is_Tagged_Type (Id);
9169 Set_Primitive_Operations (Id, New_Elmt_List);
9174 ("full declaration of } must be a tagged type", Prev, Id);
9182 -- New type declaration
9189 -------------------------
9190 -- Find_Type_Of_Object --
9191 -------------------------
9193 function Find_Type_Of_Object
9195 Related_Nod : Node_Id)
9198 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
9199 P : constant Node_Id := Parent (Obj_Def);
9204 -- Case of an anonymous array subtype
9206 if Def_Kind = N_Constrained_Array_Definition
9207 or else Def_Kind = N_Unconstrained_Array_Definition
9210 Array_Type_Declaration (T, Obj_Def);
9212 -- Create an explicit subtype whenever possible.
9214 elsif Nkind (P) /= N_Component_Declaration
9215 and then Def_Kind = N_Subtype_Indication
9217 -- Base name of subtype on object name, which will be unique in
9218 -- the current scope.
9220 -- If this is a duplicate declaration, return base type, to avoid
9221 -- generating duplicate anonymous types.
9223 if Error_Posted (P) then
9224 Analyze (Subtype_Mark (Obj_Def));
9225 return Entity (Subtype_Mark (Obj_Def));
9230 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
9232 T := Make_Defining_Identifier (Sloc (P), Nam);
9234 Insert_Action (Obj_Def,
9235 Make_Subtype_Declaration (Sloc (P),
9236 Defining_Identifier => T,
9237 Subtype_Indication => Relocate_Node (Obj_Def)));
9239 -- This subtype may need freezing and it will not be done
9240 -- automatically if the object declaration is not in a
9241 -- declarative part. Since this is an object declaration, the
9242 -- type cannot always be frozen here. Deferred constants do not
9243 -- freeze their type (which often enough will be private).
9245 if Nkind (P) = N_Object_Declaration
9246 and then Constant_Present (P)
9247 and then No (Expression (P))
9252 Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
9256 T := Process_Subtype (Obj_Def, Related_Nod);
9260 end Find_Type_Of_Object;
9262 --------------------------------
9263 -- Find_Type_Of_Subtype_Indic --
9264 --------------------------------
9266 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
9270 -- Case of subtype mark with a constraint
9272 if Nkind (S) = N_Subtype_Indication then
9273 Find_Type (Subtype_Mark (S));
9274 Typ := Entity (Subtype_Mark (S));
9277 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
9280 ("incorrect constraint for this kind of type", Constraint (S));
9281 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
9284 -- Otherwise we have a subtype mark without a constraint
9291 if Typ = Standard_Wide_Character
9292 or else Typ = Standard_Wide_String
9294 Check_Restriction (No_Wide_Characters, S);
9298 end Find_Type_Of_Subtype_Indic;
9300 -------------------------------------
9301 -- Floating_Point_Type_Declaration --
9302 -------------------------------------
9304 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
9305 Digs : constant Node_Id := Digits_Expression (Def);
9307 Base_Typ : Entity_Id;
9308 Implicit_Base : Entity_Id;
9311 function Can_Derive_From (E : Entity_Id) return Boolean;
9312 -- Find if given digits value allows derivation from specified type
9314 function Can_Derive_From (E : Entity_Id) return Boolean is
9315 Spec : constant Entity_Id := Real_Range_Specification (Def);
9318 if Digs_Val > Digits_Value (E) then
9322 if Present (Spec) then
9323 if Expr_Value_R (Type_Low_Bound (E)) >
9324 Expr_Value_R (Low_Bound (Spec))
9329 if Expr_Value_R (Type_High_Bound (E)) <
9330 Expr_Value_R (High_Bound (Spec))
9337 end Can_Derive_From;
9339 -- Start of processing for Floating_Point_Type_Declaration
9342 Check_Restriction (No_Floating_Point, Def);
9344 -- Create an implicit base type
9347 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
9349 -- Analyze and verify digits value
9351 Analyze_And_Resolve (Digs, Any_Integer);
9352 Check_Digits_Expression (Digs);
9353 Digs_Val := Expr_Value (Digs);
9355 -- Process possible range spec and find correct type to derive from
9357 Process_Real_Range_Specification (Def);
9359 if Can_Derive_From (Standard_Short_Float) then
9360 Base_Typ := Standard_Short_Float;
9361 elsif Can_Derive_From (Standard_Float) then
9362 Base_Typ := Standard_Float;
9363 elsif Can_Derive_From (Standard_Long_Float) then
9364 Base_Typ := Standard_Long_Float;
9365 elsif Can_Derive_From (Standard_Long_Long_Float) then
9366 Base_Typ := Standard_Long_Long_Float;
9368 -- If we can't derive from any existing type, use long long float
9369 -- and give appropriate message explaining the problem.
9372 Base_Typ := Standard_Long_Long_Float;
9374 if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
9375 Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
9376 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
9380 ("range too large for any predefined type",
9381 Real_Range_Specification (Def));
9385 -- If there are bounds given in the declaration use them as the bounds
9386 -- of the type, otherwise use the bounds of the predefined base type
9387 -- that was chosen based on the Digits value.
9389 if Present (Real_Range_Specification (Def)) then
9390 Set_Scalar_Range (T, Real_Range_Specification (Def));
9391 Set_Is_Constrained (T);
9393 -- The bounds of this range must be converted to machine numbers
9394 -- in accordance with RM 4.9(38).
9396 Bound := Type_Low_Bound (T);
9398 if Nkind (Bound) = N_Real_Literal then
9399 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9400 Set_Is_Machine_Number (Bound);
9403 Bound := Type_High_Bound (T);
9405 if Nkind (Bound) = N_Real_Literal then
9406 Set_Realval (Bound, Machine (Base_Typ, Realval (Bound), Round));
9407 Set_Is_Machine_Number (Bound);
9411 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
9414 -- Complete definition of implicit base and declared first subtype
9416 Set_Etype (Implicit_Base, Base_Typ);
9418 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
9419 Set_Size_Info (Implicit_Base, (Base_Typ));
9420 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
9421 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
9422 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
9423 Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
9425 Set_Ekind (T, E_Floating_Point_Subtype);
9426 Set_Etype (T, Implicit_Base);
9428 Set_Size_Info (T, (Implicit_Base));
9429 Set_RM_Size (T, RM_Size (Implicit_Base));
9430 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
9431 Set_Digits_Value (T, Digs_Val);
9433 end Floating_Point_Type_Declaration;
9435 ----------------------------
9436 -- Get_Discriminant_Value --
9437 ----------------------------
9439 -- This is the situation...
9441 -- There is a non-derived type
9443 -- type T0 (Dx, Dy, Dz...)
9445 -- There are zero or more levels of derivation, with each
9446 -- derivation either purely inheriting the discriminants, or
9447 -- defining its own.
9449 -- type Ti is new Ti-1
9451 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
9453 -- subtype Ti is ...
9455 -- The subtype issue is avoided by the use of
9456 -- Original_Record_Component, and the fact that derived subtypes
9457 -- also derive the constraits.
9459 -- This chain leads back from
9461 -- Typ_For_Constraint
9463 -- Typ_For_Constraint has discriminants, and the value for each
9464 -- discriminant is given by its corresponding Elmt of Constraints.
9466 -- Discriminant is some discriminant in this hierarchy.
9468 -- We need to return its value.
9470 -- We do this by recursively searching each level, and looking for
9471 -- Discriminant. Once we get to the bottom, we start backing up
9472 -- returning the value for it which may in turn be a discriminant
9473 -- further up, so on the backup we continue the substitution.
9475 function Get_Discriminant_Value
9476 (Discriminant : Entity_Id;
9477 Typ_For_Constraint : Entity_Id;
9478 Constraint : Elist_Id)
9483 Discrim_Values : Elist_Id;
9484 Girder_Discrim_Values : Boolean)
9485 return Node_Or_Entity_Id;
9486 -- This is the routine that performs the recursive search of levels
9487 -- as described above.
9491 Discrim_Values : Elist_Id;
9492 Girder_Discrim_Values : Boolean)
9493 return Node_Or_Entity_Id
9497 Result : Node_Or_Entity_Id;
9498 Result_Entity : Node_Id;
9501 -- If inappropriate type, return Error, this happens only in
9502 -- cascaded error situations, and we want to avoid a blow up.
9504 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
9508 -- Look deeper if possible. Use Girder_Constraints only for
9509 -- untagged types. For tagged types use the given constraint.
9510 -- This asymmetry needs explanation???
9512 if not Girder_Discrim_Values
9513 and then Present (Girder_Constraint (Ti))
9514 and then not Is_Tagged_Type (Ti)
9516 Result := Recurse (Ti, Girder_Constraint (Ti), True);
9519 Td : Entity_Id := Etype (Ti);
9523 Result := Discriminant;
9526 if Present (Girder_Constraint (Ti)) then
9528 Recurse (Td, Girder_Constraint (Ti), True);
9531 Recurse (Td, Discrim_Values, Girder_Discrim_Values);
9537 -- Extra underlying places to search, if not found above. For
9538 -- concurrent types, the relevant discriminant appears in the
9539 -- corresponding record. For a type derived from a private type
9540 -- without discriminant, the full view inherits the discriminants
9541 -- of the full view of the parent.
9543 if Result = Discriminant then
9544 if Is_Concurrent_Type (Ti)
9545 and then Present (Corresponding_Record_Type (Ti))
9549 Corresponding_Record_Type (Ti),
9551 Girder_Discrim_Values);
9553 elsif Is_Private_Type (Ti)
9554 and then not Has_Discriminants (Ti)
9555 and then Present (Full_View (Ti))
9556 and then Etype (Full_View (Ti)) /= Ti
9562 Girder_Discrim_Values);
9566 -- If Result is not a (reference to a) discriminant,
9567 -- return it, otherwise set Result_Entity to the discriminant.
9569 if Nkind (Result) = N_Defining_Identifier then
9571 pragma Assert (Result = Discriminant);
9573 Result_Entity := Result;
9576 if not Denotes_Discriminant (Result) then
9580 Result_Entity := Entity (Result);
9583 -- See if this level of derivation actually has discriminants
9584 -- because tagged derivations can add them, hence the lower
9585 -- levels need not have any.
9587 if not Has_Discriminants (Ti) then
9591 -- Scan Ti's discriminants for Result_Entity,
9592 -- and return its corresponding value, if any.
9594 Result_Entity := Original_Record_Component (Result_Entity);
9596 Assoc := First_Elmt (Discrim_Values);
9598 if Girder_Discrim_Values then
9599 Disc := First_Girder_Discriminant (Ti);
9601 Disc := First_Discriminant (Ti);
9604 while Present (Disc) loop
9606 pragma Assert (Present (Assoc));
9608 if Original_Record_Component (Disc) = Result_Entity then
9609 return Node (Assoc);
9614 if Girder_Discrim_Values then
9615 Next_Girder_Discriminant (Disc);
9617 Next_Discriminant (Disc);
9621 -- Could not find it
9626 Result : Node_Or_Entity_Id;
9628 -- Start of processing for Get_Discriminant_Value
9631 -- ??? this routine is a gigantic mess and will be deleted.
9632 -- for the time being just test for the trivial case before calling
9635 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
9637 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9638 E : Elmt_Id := First_Elmt (Constraint);
9640 while Present (D) loop
9641 if Chars (D) = Chars (Discriminant) then
9645 Next_Discriminant (D);
9651 Result := Recurse (Typ_For_Constraint, Constraint, False);
9653 -- ??? hack to disappear when this routine is gone
9655 if Nkind (Result) = N_Defining_Identifier then
9657 D : Entity_Id := First_Discriminant (Typ_For_Constraint);
9658 E : Elmt_Id := First_Elmt (Constraint);
9660 while Present (D) loop
9661 if Corresponding_Discriminant (D) = Discriminant then
9665 Next_Discriminant (D);
9671 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
9673 end Get_Discriminant_Value;
9675 --------------------------
9676 -- Has_Range_Constraint --
9677 --------------------------
9679 function Has_Range_Constraint (N : Node_Id) return Boolean is
9680 C : constant Node_Id := Constraint (N);
9683 if Nkind (C) = N_Range_Constraint then
9686 elsif Nkind (C) = N_Digits_Constraint then
9688 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
9690 Present (Range_Constraint (C));
9692 elsif Nkind (C) = N_Delta_Constraint then
9693 return Present (Range_Constraint (C));
9698 end Has_Range_Constraint;
9700 ------------------------
9701 -- Inherit_Components --
9702 ------------------------
9704 function Inherit_Components
9706 Parent_Base : Entity_Id;
9707 Derived_Base : Entity_Id;
9708 Is_Tagged : Boolean;
9709 Inherit_Discr : Boolean;
9713 Assoc_List : Elist_Id := New_Elmt_List;
9715 procedure Inherit_Component
9717 Plain_Discrim : Boolean := False;
9718 Girder_Discrim : Boolean := False);
9719 -- Inherits component Old_C from Parent_Base to the Derived_Base.
9720 -- If Plain_Discrim is True, Old_C is a discriminant.
9721 -- If Girder_Discrim is True, Old_C is a girder discriminant.
9722 -- If they are both false then Old_C is a regular component.
9724 -----------------------
9725 -- Inherit_Component --
9726 -----------------------
9728 procedure Inherit_Component
9730 Plain_Discrim : Boolean := False;
9731 Girder_Discrim : Boolean := False)
9733 New_C : Entity_Id := New_Copy (Old_C);
9735 Discrim : Entity_Id;
9736 Corr_Discrim : Entity_Id;
9739 pragma Assert (not Is_Tagged or else not Girder_Discrim);
9741 Set_Parent (New_C, Parent (Old_C));
9743 -- Regular discriminants and components must be inserted
9744 -- in the scope of the Derived_Base. Do it here.
9746 if not Girder_Discrim then
9750 -- For tagged types the Original_Record_Component must point to
9751 -- whatever this field was pointing to in the parent type. This has
9752 -- already been achieved by the call to New_Copy above.
9754 if not Is_Tagged then
9755 Set_Original_Record_Component (New_C, New_C);
9758 -- If we have inherited a component then see if its Etype contains
9759 -- references to Parent_Base discriminants. In this case, replace
9760 -- these references with the constraints given in Discs. We do not
9761 -- do this for the partial view of private types because this is
9762 -- not needed (only the components of the full view will be used
9763 -- for code generation) and cause problem. We also avoid this
9764 -- transformation in some error situations.
9766 if Ekind (New_C) = E_Component then
9767 if (Is_Private_Type (Derived_Base)
9768 and then not Is_Generic_Type (Derived_Base))
9769 or else (Is_Empty_Elmt_List (Discs)
9770 and then not Expander_Active)
9772 Set_Etype (New_C, Etype (Old_C));
9774 Set_Etype (New_C, Constrain_Component_Type (Etype (Old_C),
9775 Derived_Base, N, Parent_Base, Discs));
9779 -- In derived tagged types it is illegal to reference a non
9780 -- discriminant component in the parent type. To catch this, mark
9781 -- these components with an Ekind of E_Void. This will be reset in
9782 -- Record_Type_Definition after processing the record extension of
9783 -- the derived type.
9785 if Is_Tagged and then Ekind (New_C) = E_Component then
9786 Set_Ekind (New_C, E_Void);
9789 if Plain_Discrim then
9790 Set_Corresponding_Discriminant (New_C, Old_C);
9791 Build_Discriminal (New_C);
9793 -- If we are explicitely inheriting a girder discriminant it will be
9794 -- completely hidden.
9796 elsif Girder_Discrim then
9797 Set_Corresponding_Discriminant (New_C, Empty);
9798 Set_Discriminal (New_C, Empty);
9799 Set_Is_Completely_Hidden (New_C);
9801 -- Set the Original_Record_Component of each discriminant in the
9802 -- derived base to point to the corresponding girder that we just
9805 Discrim := First_Discriminant (Derived_Base);
9806 while Present (Discrim) loop
9807 Corr_Discrim := Corresponding_Discriminant (Discrim);
9809 -- Corr_Discrimm could be missing in an error situation.
9811 if Present (Corr_Discrim)
9812 and then Original_Record_Component (Corr_Discrim) = Old_C
9814 Set_Original_Record_Component (Discrim, New_C);
9817 Next_Discriminant (Discrim);
9820 Append_Entity (New_C, Derived_Base);
9823 if not Is_Tagged then
9824 Append_Elmt (Old_C, Assoc_List);
9825 Append_Elmt (New_C, Assoc_List);
9827 end Inherit_Component;
9829 -- Variables local to Inherit_Components.
9831 Loc : constant Source_Ptr := Sloc (N);
9833 Parent_Discrim : Entity_Id;
9834 Girder_Discrim : Entity_Id;
9837 Component : Entity_Id;
9839 -- Start of processing for Inherit_Components
9842 if not Is_Tagged then
9843 Append_Elmt (Parent_Base, Assoc_List);
9844 Append_Elmt (Derived_Base, Assoc_List);
9847 -- Inherit parent discriminants if needed.
9849 if Inherit_Discr then
9850 Parent_Discrim := First_Discriminant (Parent_Base);
9851 while Present (Parent_Discrim) loop
9852 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
9853 Next_Discriminant (Parent_Discrim);
9857 -- Create explicit girder discrims for untagged types when necessary.
9859 if not Has_Unknown_Discriminants (Derived_Base)
9860 and then Has_Discriminants (Parent_Base)
9861 and then not Is_Tagged
9864 or else First_Discriminant (Parent_Base) /=
9865 First_Girder_Discriminant (Parent_Base))
9867 Girder_Discrim := First_Girder_Discriminant (Parent_Base);
9868 while Present (Girder_Discrim) loop
9869 Inherit_Component (Girder_Discrim, Girder_Discrim => True);
9870 Next_Girder_Discriminant (Girder_Discrim);
9874 -- See if we can apply the second transformation for derived types, as
9875 -- explained in point 6. in the comments above Build_Derived_Record_Type
9876 -- This is achieved by appending Derived_Base discriminants into
9877 -- Discs, which has the side effect of returning a non empty Discs
9878 -- list to the caller of Inherit_Components, which is what we want.
9881 and then Is_Empty_Elmt_List (Discs)
9882 and then (not Is_Private_Type (Derived_Base)
9883 or Is_Generic_Type (Derived_Base))
9885 D := First_Discriminant (Derived_Base);
9886 while Present (D) loop
9887 Append_Elmt (New_Reference_To (D, Loc), Discs);
9888 Next_Discriminant (D);
9892 -- Finally, inherit non-discriminant components unless they are not
9893 -- visible because defined or inherited from the full view of the
9894 -- parent. Don't inherit the _parent field of the parent type.
9896 Component := First_Entity (Parent_Base);
9897 while Present (Component) loop
9898 if Ekind (Component) /= E_Component
9899 or else Chars (Component) = Name_uParent
9903 -- If the derived type is within the parent type's declarative
9904 -- region, then the components can still be inherited even though
9905 -- they aren't visible at this point. This can occur for cases
9906 -- such as within public child units where the components must
9907 -- become visible upon entering the child unit's private part.
9909 elsif not Is_Visible_Component (Component)
9910 and then not In_Open_Scopes (Scope (Parent_Base))
9914 elsif Ekind (Derived_Base) = E_Private_Type
9915 or else Ekind (Derived_Base) = E_Limited_Private_Type
9920 Inherit_Component (Component);
9923 Next_Entity (Component);
9926 -- For tagged derived types, inherited discriminants cannot be used in
9927 -- component declarations of the record extension part. To achieve this
9928 -- we mark the inherited discriminants as not visible.
9930 if Is_Tagged and then Inherit_Discr then
9931 D := First_Discriminant (Derived_Base);
9932 while Present (D) loop
9933 Set_Is_Immediately_Visible (D, False);
9934 Next_Discriminant (D);
9939 end Inherit_Components;
9941 ------------------------------
9942 -- Is_Valid_Constraint_Kind --
9943 ------------------------------
9945 function Is_Valid_Constraint_Kind
9946 (T_Kind : Type_Kind;
9947 Constraint_Kind : Node_Kind)
9953 when Enumeration_Kind |
9955 return Constraint_Kind = N_Range_Constraint;
9957 when Decimal_Fixed_Point_Kind =>
9959 Constraint_Kind = N_Digits_Constraint
9961 Constraint_Kind = N_Range_Constraint;
9963 when Ordinary_Fixed_Point_Kind =>
9965 Constraint_Kind = N_Delta_Constraint
9967 Constraint_Kind = N_Range_Constraint;
9971 Constraint_Kind = N_Digits_Constraint
9973 Constraint_Kind = N_Range_Constraint;
9983 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
9986 return True; -- Error will be detected later.
9989 end Is_Valid_Constraint_Kind;
9991 --------------------------
9992 -- Is_Visible_Component --
9993 --------------------------
9995 function Is_Visible_Component (C : Entity_Id) return Boolean is
9996 Original_Comp : constant Entity_Id := Original_Record_Component (C);
9997 Original_Scope : Entity_Id;
10000 if No (Original_Comp) then
10002 -- Premature usage, or previous error
10007 Original_Scope := Scope (Original_Comp);
10010 -- This test only concern tagged types
10012 if not Is_Tagged_Type (Original_Scope) then
10015 -- If it is _Parent or _Tag, there is no visiblity issue
10017 elsif not Comes_From_Source (Original_Comp) then
10020 -- If we are in the body of an instantiation, the component is
10021 -- visible even when the parent type (possibly defined in an
10022 -- enclosing unit or in a parent unit) might not.
10024 elsif In_Instance_Body then
10027 -- Discriminants are always visible.
10029 elsif Ekind (Original_Comp) = E_Discriminant
10030 and then not Has_Unknown_Discriminants (Original_Scope)
10034 -- If the component has been declared in an ancestor which is
10035 -- currently a private type, then it is not visible. The same
10036 -- applies if the component's containing type is not in an
10037 -- open scope and the original component's enclosing type
10038 -- is a visible full type of a private type (which can occur
10039 -- in cases where an attempt is being made to reference a
10040 -- component in a sibling package that is inherited from
10041 -- a visible component of a type in an ancestor package;
10042 -- the component in the sibling package should not be
10043 -- visible even though the component it inherited from
10044 -- is visible). This does not apply however in the case
10045 -- where the scope of the type is a private child unit.
10046 -- The latter suppression of visibility is needed for cases
10047 -- that are tested in B730006.
10049 elsif (Ekind (Original_Comp) /= E_Discriminant
10050 or else Has_Unknown_Discriminants (Original_Scope))
10052 (Is_Private_Type (Original_Scope)
10054 (not Is_Private_Descendant (Scope (Base_Type (Scope (C))))
10055 and then not In_Open_Scopes (Scope (Base_Type (Scope (C))))
10056 and then Has_Private_Declaration (Original_Scope)))
10060 -- There is another weird way in which a component may be invisible
10061 -- when the private and the full view are not derived from the same
10062 -- ancestor. Here is an example :
10064 -- type A1 is tagged record F1 : integer; end record;
10065 -- type A2 is new A1 with record F2 : integer; end record;
10066 -- type T is new A1 with private;
10068 -- type T is new A2 with private;
10070 -- In this case, the full view of T inherits F1 and F2 but the
10071 -- private view inherits only F1
10075 Ancestor : Entity_Id := Scope (C);
10079 if Ancestor = Original_Scope then
10081 elsif Ancestor = Etype (Ancestor) then
10085 Ancestor := Etype (Ancestor);
10091 end Is_Visible_Component;
10093 --------------------------
10094 -- Make_Class_Wide_Type --
10095 --------------------------
10097 procedure Make_Class_Wide_Type (T : Entity_Id) is
10098 CW_Type : Entity_Id;
10100 Next_E : Entity_Id;
10103 -- The class wide type can have been defined by the partial view in
10104 -- which case everything is already done
10106 if Present (Class_Wide_Type (T)) then
10111 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
10113 -- Inherit root type characteristics
10115 CW_Name := Chars (CW_Type);
10116 Next_E := Next_Entity (CW_Type);
10117 Copy_Node (T, CW_Type);
10118 Set_Comes_From_Source (CW_Type, False);
10119 Set_Chars (CW_Type, CW_Name);
10120 Set_Parent (CW_Type, Parent (T));
10121 Set_Next_Entity (CW_Type, Next_E);
10122 Set_Has_Delayed_Freeze (CW_Type);
10124 -- Customize the class-wide type: It has no prim. op., it cannot be
10125 -- abstract and its Etype points back to the root type
10127 Set_Ekind (CW_Type, E_Class_Wide_Type);
10128 Set_Is_Tagged_Type (CW_Type, True);
10129 Set_Primitive_Operations (CW_Type, New_Elmt_List);
10130 Set_Is_Abstract (CW_Type, False);
10131 Set_Etype (CW_Type, T);
10132 Set_Is_Constrained (CW_Type, False);
10133 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
10134 Init_Size_Align (CW_Type);
10136 -- If this is the class_wide type of a constrained subtype, it does
10137 -- not have discriminants.
10139 Set_Has_Discriminants (CW_Type,
10140 Has_Discriminants (T) and then not Is_Constrained (T));
10142 Set_Has_Unknown_Discriminants (CW_Type, True);
10143 Set_Class_Wide_Type (T, CW_Type);
10144 Set_Equivalent_Type (CW_Type, Empty);
10146 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
10148 Set_Class_Wide_Type (CW_Type, CW_Type);
10150 end Make_Class_Wide_Type;
10156 procedure Make_Index
10158 Related_Nod : Node_Id;
10159 Related_Id : Entity_Id := Empty;
10160 Suffix_Index : Nat := 1)
10164 Def_Id : Entity_Id := Empty;
10165 Found : Boolean := False;
10168 -- For a discrete range used in a constrained array definition and
10169 -- defined by a range, an implicit conversion to the predefined type
10170 -- INTEGER is assumed if each bound is either a numeric literal, a named
10171 -- number, or an attribute, and the type of both bounds (prior to the
10172 -- implicit conversion) is the type universal_integer. Otherwise, both
10173 -- bounds must be of the same discrete type, other than universal
10174 -- integer; this type must be determinable independently of the
10175 -- context, but using the fact that the type must be discrete and that
10176 -- both bounds must have the same type.
10178 -- Character literals also have a universal type in the absence of
10179 -- of additional context, and are resolved to Standard_Character.
10181 if Nkind (I) = N_Range then
10183 -- The index is given by a range constraint. The bounds are known
10184 -- to be of a consistent type.
10186 if not Is_Overloaded (I) then
10189 -- If the bounds are universal, choose the specific predefined
10192 if T = Universal_Integer then
10193 T := Standard_Integer;
10195 elsif T = Any_Character then
10199 ("ambiguous character literals (could be Wide_Character)",
10203 T := Standard_Character;
10210 Ind : Interp_Index;
10214 Get_First_Interp (I, Ind, It);
10216 while Present (It.Typ) loop
10217 if Is_Discrete_Type (It.Typ) then
10220 and then not Covers (It.Typ, T)
10221 and then not Covers (T, It.Typ)
10223 Error_Msg_N ("ambiguous bounds in discrete range", I);
10231 Get_Next_Interp (Ind, It);
10234 if T = Any_Type then
10235 Error_Msg_N ("discrete type required for range", I);
10236 Set_Etype (I, Any_Type);
10239 elsif T = Universal_Integer then
10240 T := Standard_Integer;
10245 if not Is_Discrete_Type (T) then
10246 Error_Msg_N ("discrete type required for range", I);
10247 Set_Etype (I, Any_Type);
10252 Process_Range_Expr_In_Decl (R, T, Related_Nod);
10254 elsif Nkind (I) = N_Subtype_Indication then
10256 -- The index is given by a subtype with a range constraint.
10258 T := Base_Type (Entity (Subtype_Mark (I)));
10260 if not Is_Discrete_Type (T) then
10261 Error_Msg_N ("discrete type required for range", I);
10262 Set_Etype (I, Any_Type);
10266 R := Range_Expression (Constraint (I));
10269 Process_Range_Expr_In_Decl (R,
10270 Entity (Subtype_Mark (I)), Related_Nod);
10272 elsif Nkind (I) = N_Attribute_Reference then
10274 -- The parser guarantees that the attribute is a RANGE attribute
10276 -- Is order critical here (setting T before Resolve). If so,
10277 -- document why, if not use Analyze_And_Resolve and get T after???
10284 -- If none of the above, must be a subtype. We convert this to a
10285 -- range attribute reference because in the case of declared first
10286 -- named subtypes, the types in the range reference can be different
10287 -- from the type of the entity. A range attribute normalizes the
10288 -- reference and obtains the correct types for the bounds.
10290 -- This transformation is in the nature of an expansion, is only
10291 -- done if expansion is active. In particular, it is not done on
10292 -- formal generic types, because we need to retain the name of the
10293 -- original index for instantiation purposes.
10296 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
10297 Error_Msg_N ("invalid subtype mark in discrete range ", I);
10298 Set_Etype (I, Any_Integer);
10301 -- The type mark may be that of an incomplete type. It is only
10302 -- now that we can get the full view, previous analysis does
10303 -- not look specifically for a type mark.
10305 Set_Entity (I, Get_Full_View (Entity (I)));
10306 Set_Etype (I, Entity (I));
10307 Def_Id := Entity (I);
10309 if not Is_Discrete_Type (Def_Id) then
10310 Error_Msg_N ("discrete type required for index", I);
10311 Set_Etype (I, Any_Type);
10316 if Expander_Active then
10318 Make_Attribute_Reference (Sloc (I),
10319 Attribute_Name => Name_Range,
10320 Prefix => Relocate_Node (I)));
10322 -- The original was a subtype mark that does not freeze. This
10323 -- means that the rewritten version must not freeze either.
10325 Set_Must_Not_Freeze (I);
10326 Set_Must_Not_Freeze (Prefix (I));
10328 -- Is order critical??? if so, document why, if not
10329 -- use Analyze_And_Resolve
10337 -- Type is legal, nothing else to construct.
10342 if not Is_Discrete_Type (T) then
10343 Error_Msg_N ("discrete type required for range", I);
10344 Set_Etype (I, Any_Type);
10347 elsif T = Any_Type then
10348 Set_Etype (I, Any_Type);
10352 -- We will now create the appropriate Itype to describe the
10353 -- range, but first a check. If we originally had a subtype,
10354 -- then we just label the range with this subtype. Not only
10355 -- is there no need to construct a new subtype, but it is wrong
10356 -- to do so for two reasons:
10358 -- 1. A legality concern, if we have a subtype, it must not
10359 -- freeze, and the Itype would cause freezing incorrectly
10361 -- 2. An efficiency concern, if we created an Itype, it would
10362 -- not be recognized as the same type for the purposes of
10363 -- eliminating checks in some circumstances.
10365 -- We signal this case by setting the subtype entity in Def_Id.
10367 -- It would be nice to also do this optimization for the cases
10368 -- of X'Range and also the explicit range X'First .. X'Last,
10369 -- but that is not done yet (it is just an efficiency concern) ???
10371 if No (Def_Id) then
10374 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
10375 Set_Etype (Def_Id, Base_Type (T));
10377 if Is_Signed_Integer_Type (T) then
10378 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
10380 elsif Is_Modular_Integer_Type (T) then
10381 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
10384 Set_Ekind (Def_Id, E_Enumeration_Subtype);
10385 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
10388 Set_Size_Info (Def_Id, (T));
10389 Set_RM_Size (Def_Id, RM_Size (T));
10390 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10392 Set_Scalar_Range (Def_Id, R);
10393 Conditional_Delay (Def_Id, T);
10395 -- In the subtype indication case, if the immediate parent of the
10396 -- new subtype is non-static, then the subtype we create is non-
10397 -- static, even if its bounds are static.
10399 if Nkind (I) = N_Subtype_Indication
10400 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
10402 Set_Is_Non_Static_Subtype (Def_Id);
10406 -- Final step is to label the index with this constructed type
10408 Set_Etype (I, Def_Id);
10411 ------------------------------
10412 -- Modular_Type_Declaration --
10413 ------------------------------
10415 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
10416 Mod_Expr : constant Node_Id := Expression (Def);
10419 procedure Set_Modular_Size (Bits : Int);
10420 -- Sets RM_Size to Bits, and Esize to normal word size above this
10422 procedure Set_Modular_Size (Bits : Int) is
10424 Set_RM_Size (T, UI_From_Int (Bits));
10429 elsif Bits <= 16 then
10430 Init_Esize (T, 16);
10432 elsif Bits <= 32 then
10433 Init_Esize (T, 32);
10436 Init_Esize (T, System_Max_Binary_Modulus_Power);
10438 end Set_Modular_Size;
10440 -- Start of processing for Modular_Type_Declaration
10443 Analyze_And_Resolve (Mod_Expr, Any_Integer);
10445 Set_Ekind (T, E_Modular_Integer_Type);
10446 Init_Alignment (T);
10447 Set_Is_Constrained (T);
10449 if not Is_OK_Static_Expression (Mod_Expr) then
10451 ("non-static expression used for modular type bound", Mod_Expr);
10452 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10454 M_Val := Expr_Value (Mod_Expr);
10458 Error_Msg_N ("modulus value must be positive", Mod_Expr);
10459 M_Val := 2 ** System_Max_Binary_Modulus_Power;
10462 Set_Modulus (T, M_Val);
10464 -- Create bounds for the modular type based on the modulus given in
10465 -- the type declaration and then analyze and resolve those bounds.
10467 Set_Scalar_Range (T,
10468 Make_Range (Sloc (Mod_Expr),
10470 Make_Integer_Literal (Sloc (Mod_Expr), 0),
10472 Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
10474 -- Properly analyze the literals for the range. We do this manually
10475 -- because we can't go calling Resolve, since we are resolving these
10476 -- bounds with the type, and this type is certainly not complete yet!
10478 Set_Etype (Low_Bound (Scalar_Range (T)), T);
10479 Set_Etype (High_Bound (Scalar_Range (T)), T);
10480 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
10481 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
10483 -- Loop through powers of two to find number of bits required
10485 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
10489 if M_Val = 2 ** Bits then
10490 Set_Modular_Size (Bits);
10495 elsif M_Val < 2 ** Bits then
10496 Set_Non_Binary_Modulus (T);
10498 if Bits > System_Max_Nonbinary_Modulus_Power then
10499 Error_Msg_Uint_1 :=
10500 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
10502 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
10503 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10507 -- In the non-binary case, set size as per RM 13.3(55).
10509 Set_Modular_Size (Bits);
10516 -- If we fall through, then the size exceed System.Max_Binary_Modulus
10517 -- so we just signal an error and set the maximum size.
10519 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
10520 Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
10522 Set_Modular_Size (System_Max_Binary_Modulus_Power);
10523 Init_Alignment (T);
10525 end Modular_Type_Declaration;
10527 -------------------------
10528 -- New_Binary_Operator --
10529 -------------------------
10531 procedure New_Binary_Operator (Op_Name : Name_Id; Typ : Entity_Id) is
10532 Loc : constant Source_Ptr := Sloc (Typ);
10535 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
10536 -- Create abbreviated declaration for the formal of a predefined
10537 -- Operator 'Op' of type 'Typ'
10539 --------------------
10540 -- Make_Op_Formal --
10541 --------------------
10543 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
10544 Formal : Entity_Id;
10547 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
10548 Set_Etype (Formal, Typ);
10549 Set_Mechanism (Formal, Default_Mechanism);
10551 end Make_Op_Formal;
10553 -- Start of processing for New_Binary_Operator
10556 Op := Make_Defining_Operator_Symbol (Loc, Op_Name);
10558 Set_Ekind (Op, E_Operator);
10559 Set_Scope (Op, Current_Scope);
10560 Set_Etype (Op, Typ);
10561 Set_Homonym (Op, Get_Name_Entity_Id (Op_Name));
10562 Set_Is_Immediately_Visible (Op);
10563 Set_Is_Intrinsic_Subprogram (Op);
10564 Set_Has_Completion (Op);
10565 Append_Entity (Op, Current_Scope);
10567 Set_Name_Entity_Id (Op_Name, Op);
10569 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10570 Append_Entity (Make_Op_Formal (Typ, Op), Op);
10572 end New_Binary_Operator;
10574 -------------------------------------------
10575 -- Ordinary_Fixed_Point_Type_Declaration --
10576 -------------------------------------------
10578 procedure Ordinary_Fixed_Point_Type_Declaration
10582 Loc : constant Source_Ptr := Sloc (Def);
10583 Delta_Expr : constant Node_Id := Delta_Expression (Def);
10584 RRS : constant Node_Id := Real_Range_Specification (Def);
10585 Implicit_Base : Entity_Id;
10592 Check_Restriction (No_Fixed_Point, Def);
10594 -- Create implicit base type
10597 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
10598 Set_Etype (Implicit_Base, Implicit_Base);
10600 -- Analyze and process delta expression
10602 Analyze_And_Resolve (Delta_Expr, Any_Real);
10604 Check_Delta_Expression (Delta_Expr);
10605 Delta_Val := Expr_Value_R (Delta_Expr);
10607 Set_Delta_Value (Implicit_Base, Delta_Val);
10609 -- Compute default small from given delta, which is the largest
10610 -- power of two that does not exceed the given delta value.
10613 Tmp : Ureal := Ureal_1;
10617 if Delta_Val < Ureal_1 then
10618 while Delta_Val < Tmp loop
10619 Tmp := Tmp / Ureal_2;
10620 Scale := Scale + 1;
10625 Tmp := Tmp * Ureal_2;
10626 exit when Tmp > Delta_Val;
10627 Scale := Scale - 1;
10631 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
10634 Set_Small_Value (Implicit_Base, Small_Val);
10636 -- If no range was given, set a dummy range
10638 if RRS <= Empty_Or_Error then
10639 Low_Val := -Small_Val;
10640 High_Val := Small_Val;
10642 -- Otherwise analyze and process given range
10646 Low : constant Node_Id := Low_Bound (RRS);
10647 High : constant Node_Id := High_Bound (RRS);
10650 Analyze_And_Resolve (Low, Any_Real);
10651 Analyze_And_Resolve (High, Any_Real);
10652 Check_Real_Bound (Low);
10653 Check_Real_Bound (High);
10655 -- Obtain and set the range
10657 Low_Val := Expr_Value_R (Low);
10658 High_Val := Expr_Value_R (High);
10660 if Low_Val > High_Val then
10661 Error_Msg_NE ("?fixed point type& has null range", Def, T);
10666 -- The range for both the implicit base and the declared first
10667 -- subtype cannot be set yet, so we use the special routine
10668 -- Set_Fixed_Range to set a temporary range in place. Note that
10669 -- the bounds of the base type will be widened to be symmetrical
10670 -- and to fill the available bits when the type is frozen.
10672 -- We could do this with all discrete types, and probably should, but
10673 -- we absolutely have to do it for fixed-point, since the end-points
10674 -- of the range and the size are determined by the small value, which
10675 -- could be reset before the freeze point.
10677 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
10678 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
10680 Init_Size_Align (Implicit_Base);
10682 -- Complete definition of first subtype
10684 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
10685 Set_Etype (T, Implicit_Base);
10686 Init_Size_Align (T);
10687 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
10688 Set_Small_Value (T, Small_Val);
10689 Set_Delta_Value (T, Delta_Val);
10690 Set_Is_Constrained (T);
10692 end Ordinary_Fixed_Point_Type_Declaration;
10694 ----------------------------------------
10695 -- Prepare_Private_Subtype_Completion --
10696 ----------------------------------------
10698 procedure Prepare_Private_Subtype_Completion
10700 Related_Nod : Node_Id)
10702 Id_B : constant Entity_Id := Base_Type (Id);
10703 Full_B : constant Entity_Id := Full_View (Id_B);
10707 if Present (Full_B) then
10709 -- The Base_Type is already completed, we can complete the
10710 -- subtype now. We have to create a new entity with the same name,
10711 -- Thus we can't use Create_Itype.
10712 -- This is messy, should be fixed ???
10714 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
10715 Set_Is_Itype (Full);
10716 Set_Associated_Node_For_Itype (Full, Related_Nod);
10717 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
10720 -- The parent subtype may be private, but the base might not, in some
10721 -- nested instances. In that case, the subtype does not need to be
10722 -- exchanged. It would still be nice to make private subtypes and their
10723 -- bases consistent at all times ???
10725 if Is_Private_Type (Id_B) then
10726 Append_Elmt (Id, Private_Dependents (Id_B));
10729 end Prepare_Private_Subtype_Completion;
10731 ---------------------------
10732 -- Process_Discriminants --
10733 ---------------------------
10735 procedure Process_Discriminants (N : Node_Id) is
10738 Discr_Number : Uint;
10739 Discr_Type : Entity_Id;
10740 Default_Present : Boolean := False;
10741 Default_Not_Present : Boolean := False;
10742 Elist : Elist_Id := New_Elmt_List;
10745 -- A composite type other than an array type can have discriminants.
10746 -- Discriminants of non-limited types must have a discrete type.
10747 -- On entry, the current scope is the composite type.
10749 -- The discriminants are initially entered into the scope of the type
10750 -- via Enter_Name with the default Ekind of E_Void to prevent premature
10751 -- use, as explained at the end of this procedure.
10753 Discr := First (Discriminant_Specifications (N));
10754 while Present (Discr) loop
10755 Enter_Name (Defining_Identifier (Discr));
10757 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
10758 Discr_Type := Access_Definition (N, Discriminant_Type (Discr));
10761 Find_Type (Discriminant_Type (Discr));
10762 Discr_Type := Etype (Discriminant_Type (Discr));
10764 if Error_Posted (Discriminant_Type (Discr)) then
10765 Discr_Type := Any_Type;
10769 if Is_Access_Type (Discr_Type) then
10770 Check_Access_Discriminant_Requires_Limited
10771 (Discr, Discriminant_Type (Discr));
10773 if Ada_83 and then Comes_From_Source (Discr) then
10775 ("(Ada 83) access discriminant not allowed", Discr);
10778 elsif not Is_Discrete_Type (Discr_Type) then
10779 Error_Msg_N ("discriminants must have a discrete or access type",
10780 Discriminant_Type (Discr));
10783 Set_Etype (Defining_Identifier (Discr), Discr_Type);
10785 -- If a discriminant specification includes the assignment compound
10786 -- delimiter followed by an expression, the expression is the default
10787 -- expression of the discriminant; the default expression must be of
10788 -- the type of the discriminant. (RM 3.7.1) Since this expression is
10789 -- a default expression, we do the special preanalysis, since this
10790 -- expression does not freeze (see "Handling of Default Expressions"
10791 -- in spec of package Sem).
10793 if Present (Expression (Discr)) then
10794 Analyze_Default_Expression (Expression (Discr), Discr_Type);
10796 if Nkind (N) = N_Formal_Type_Declaration then
10798 ("discriminant defaults not allowed for formal type",
10799 Expression (Discr));
10801 elsif Is_Tagged_Type (Current_Scope) then
10803 ("discriminants of tagged type cannot have defaults",
10804 Expression (Discr));
10807 Default_Present := True;
10808 Append_Elmt (Expression (Discr), Elist);
10810 -- Tag the defining identifiers for the discriminants with
10811 -- their corresponding default expressions from the tree.
10813 Set_Discriminant_Default_Value
10814 (Defining_Identifier (Discr), Expression (Discr));
10818 Default_Not_Present := True;
10824 -- An element list consisting of the default expressions of the
10825 -- discriminants is constructed in the above loop and used to set
10826 -- the Discriminant_Constraint attribute for the type. If an object
10827 -- is declared of this (record or task) type without any explicit
10828 -- discriminant constraint given, this element list will form the
10829 -- actual parameters for the corresponding initialization procedure
10832 Set_Discriminant_Constraint (Current_Scope, Elist);
10833 Set_Girder_Constraint (Current_Scope, No_Elist);
10835 -- Default expressions must be provided either for all or for none
10836 -- of the discriminants of a discriminant part. (RM 3.7.1)
10838 if Default_Present and then Default_Not_Present then
10840 ("incomplete specification of defaults for discriminants", N);
10843 -- The use of the name of a discriminant is not allowed in default
10844 -- expressions of a discriminant part if the specification of the
10845 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
10847 -- To detect this, the discriminant names are entered initially with an
10848 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
10849 -- attempt to use a void entity (for example in an expression that is
10850 -- type-checked) produces the error message: premature usage. Now after
10851 -- completing the semantic analysis of the discriminant part, we can set
10852 -- the Ekind of all the discriminants appropriately.
10854 Discr := First (Discriminant_Specifications (N));
10855 Discr_Number := Uint_1;
10857 while Present (Discr) loop
10858 Id := Defining_Identifier (Discr);
10859 Set_Ekind (Id, E_Discriminant);
10860 Init_Component_Location (Id);
10862 Set_Discriminant_Number (Id, Discr_Number);
10864 -- Make sure this is always set, even in illegal programs
10866 Set_Corresponding_Discriminant (Id, Empty);
10868 -- Initialize the Original_Record_Component to the entity itself.
10869 -- Inherit_Components will propagate the right value to
10870 -- discriminants in derived record types.
10872 Set_Original_Record_Component (Id, Id);
10874 -- Create the discriminal for the discriminant.
10876 Build_Discriminal (Id);
10879 Discr_Number := Discr_Number + 1;
10882 Set_Has_Discriminants (Current_Scope);
10883 end Process_Discriminants;
10885 -----------------------
10886 -- Process_Full_View --
10887 -----------------------
10889 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
10890 Priv_Parent : Entity_Id;
10891 Full_Parent : Entity_Id;
10892 Full_Indic : Node_Id;
10895 -- First some sanity checks that must be done after semantic
10896 -- decoration of the full view and thus cannot be placed with other
10897 -- similar checks in Find_Type_Name
10899 if not Is_Limited_Type (Priv_T)
10900 and then (Is_Limited_Type (Full_T)
10901 or else Is_Limited_Composite (Full_T))
10904 ("completion of nonlimited type cannot be limited", Full_T);
10906 elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
10908 ("completion of nonabstract type cannot be abstract", Full_T);
10910 elsif Is_Tagged_Type (Priv_T)
10911 and then Is_Limited_Type (Priv_T)
10912 and then not Is_Limited_Type (Full_T)
10914 -- GNAT allow its own definition of Limited_Controlled to disobey
10915 -- this rule in order in ease the implementation. The next test is
10916 -- safe because Root_Controlled is defined in a private system child
10918 if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
10919 Set_Is_Limited_Composite (Full_T);
10922 ("completion of limited tagged type must be limited", Full_T);
10925 elsif Is_Generic_Type (Priv_T) then
10926 Error_Msg_N ("generic type cannot have a completion", Full_T);
10929 if Is_Tagged_Type (Priv_T)
10930 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
10931 and then Is_Derived_Type (Full_T)
10933 Priv_Parent := Etype (Priv_T);
10935 -- The full view of a private extension may have been transformed
10936 -- into an unconstrained derived type declaration and a subtype
10937 -- declaration (see build_derived_record_type for details).
10939 if Nkind (N) = N_Subtype_Declaration then
10940 Full_Indic := Subtype_Indication (N);
10941 Full_Parent := Etype (Base_Type (Full_T));
10943 Full_Indic := Subtype_Indication (Type_Definition (N));
10944 Full_Parent := Etype (Full_T);
10947 -- Check that the parent type of the full type is a descendant of
10948 -- the ancestor subtype given in the private extension. If either
10949 -- entity has an Etype equal to Any_Type then we had some previous
10950 -- error situation [7.3(8)].
10952 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
10955 elsif not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) then
10957 ("parent of full type must descend from parent"
10958 & " of private extension", Full_Indic);
10960 -- Check the rules of 7.3(10): if the private extension inherits
10961 -- known discriminants, then the full type must also inherit those
10962 -- discriminants from the same (ancestor) type, and the parent
10963 -- subtype of the full type must be constrained if and only if
10964 -- the ancestor subtype of the private extension is constrained.
10966 elsif not Present (Discriminant_Specifications (Parent (Priv_T)))
10967 and then not Has_Unknown_Discriminants (Priv_T)
10968 and then Has_Discriminants (Base_Type (Priv_Parent))
10971 Priv_Indic : constant Node_Id :=
10972 Subtype_Indication (Parent (Priv_T));
10974 Priv_Constr : constant Boolean :=
10975 Is_Constrained (Priv_Parent)
10977 Nkind (Priv_Indic) = N_Subtype_Indication
10978 or else Is_Constrained (Entity (Priv_Indic));
10980 Full_Constr : constant Boolean :=
10981 Is_Constrained (Full_Parent)
10983 Nkind (Full_Indic) = N_Subtype_Indication
10984 or else Is_Constrained (Entity (Full_Indic));
10986 Priv_Discr : Entity_Id;
10987 Full_Discr : Entity_Id;
10990 Priv_Discr := First_Discriminant (Priv_Parent);
10991 Full_Discr := First_Discriminant (Full_Parent);
10993 while Present (Priv_Discr) and then Present (Full_Discr) loop
10994 if Original_Record_Component (Priv_Discr) =
10995 Original_Record_Component (Full_Discr)
10997 Corresponding_Discriminant (Priv_Discr) =
10998 Corresponding_Discriminant (Full_Discr)
11005 Next_Discriminant (Priv_Discr);
11006 Next_Discriminant (Full_Discr);
11009 if Present (Priv_Discr) or else Present (Full_Discr) then
11011 ("full view must inherit discriminants of the parent type"
11012 & " used in the private extension", Full_Indic);
11014 elsif Priv_Constr and then not Full_Constr then
11016 ("parent subtype of full type must be constrained",
11019 elsif Full_Constr and then not Priv_Constr then
11021 ("parent subtype of full type must be unconstrained",
11026 -- Check the rules of 7.3(12): if a partial view has neither known
11027 -- or unknown discriminants, then the full type declaration shall
11028 -- define a definite subtype.
11030 elsif not Has_Unknown_Discriminants (Priv_T)
11031 and then not Has_Discriminants (Priv_T)
11032 and then not Is_Constrained (Full_T)
11035 ("full view must define a constrained type if partial view"
11036 & " has no discriminants", Full_T);
11039 -- ??????? Do we implement the following properly ?????
11040 -- If the ancestor subtype of a private extension has constrained
11041 -- discriminants, then the parent subtype of the full view shall
11042 -- impose a statically matching constraint on those discriminants
11046 -- For untagged types, verify that a type without discriminants
11047 -- is not completed with an unconstrained type.
11049 if not Is_Indefinite_Subtype (Priv_T)
11050 and then Is_Indefinite_Subtype (Full_T)
11052 Error_Msg_N ("full view of type must be definite subtype", Full_T);
11056 -- Create a full declaration for all its subtypes recorded in
11057 -- Private_Dependents and swap them similarly to the base type.
11058 -- These are subtypes that have been define before the full
11059 -- declaration of the private type. We also swap the entry in
11060 -- Private_Dependents list so we can properly restore the
11061 -- private view on exit from the scope.
11064 Priv_Elmt : Elmt_Id;
11069 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
11070 while Present (Priv_Elmt) loop
11071 Priv := Node (Priv_Elmt);
11073 if Ekind (Priv) = E_Private_Subtype
11074 or else Ekind (Priv) = E_Limited_Private_Subtype
11075 or else Ekind (Priv) = E_Record_Subtype_With_Private
11077 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
11078 Set_Is_Itype (Full);
11079 Set_Parent (Full, Parent (Priv));
11080 Set_Associated_Node_For_Itype (Full, N);
11082 -- Now we need to complete the private subtype, but since the
11083 -- base type has already been swapped, we must also swap the
11084 -- subtypes (and thus, reverse the arguments in the call to
11085 -- Complete_Private_Subtype).
11087 Copy_And_Swap (Priv, Full);
11088 Complete_Private_Subtype (Full, Priv, Full_T, N);
11089 Replace_Elmt (Priv_Elmt, Full);
11092 Next_Elmt (Priv_Elmt);
11096 -- If the private view was tagged, copy the new Primitive
11097 -- operations from the private view to the full view.
11099 if Is_Tagged_Type (Full_T) then
11101 Priv_List : Elist_Id;
11102 Full_List : constant Elist_Id := Primitive_Operations (Full_T);
11105 D_Type : Entity_Id;
11108 if Is_Tagged_Type (Priv_T) then
11109 Priv_List := Primitive_Operations (Priv_T);
11111 P1 := First_Elmt (Priv_List);
11112 while Present (P1) loop
11115 -- Transfer explicit primitives, not those inherited from
11116 -- parent of partial view, which will be re-inherited on
11119 if Comes_From_Source (Prim) then
11120 P2 := First_Elmt (Full_List);
11121 while Present (P2) and then Node (P2) /= Prim loop
11125 -- If not found, that is a new one
11128 Append_Elmt (Prim, Full_List);
11136 -- In this case the partial view is untagged, so here we
11137 -- locate all of the earlier primitives that need to be
11138 -- treated as dispatching (those that appear between the
11139 -- two views). Note that these additional operations must
11140 -- all be new operations (any earlier operations that
11141 -- override inherited operations of the full view will
11142 -- already have been inserted in the primitives list and
11143 -- marked as dispatching by Check_Operation_From_Private_View.
11144 -- Note that implicit "/=" operators are excluded from being
11145 -- added to the primitives list since they shouldn't be
11146 -- treated as dispatching (tagged "/=" is handled specially).
11148 Prim := Next_Entity (Full_T);
11149 while Present (Prim) and then Prim /= Priv_T loop
11150 if (Ekind (Prim) = E_Procedure
11151 or else Ekind (Prim) = E_Function)
11154 D_Type := Find_Dispatching_Type (Prim);
11157 and then (Chars (Prim) /= Name_Op_Ne
11158 or else Comes_From_Source (Prim))
11160 Check_Controlling_Formals (Full_T, Prim);
11162 if not Is_Dispatching_Operation (Prim) then
11163 Append_Elmt (Prim, Full_List);
11164 Set_Is_Dispatching_Operation (Prim, True);
11165 Set_DT_Position (Prim, No_Uint);
11168 elsif Is_Dispatching_Operation (Prim)
11169 and then D_Type /= Full_T
11172 -- Verify that it is not otherwise controlled by
11173 -- a formal or a return value ot type T.
11175 Check_Controlling_Formals (D_Type, Prim);
11179 Next_Entity (Prim);
11183 -- For the tagged case, the two views can share the same
11184 -- Primitive Operation list and the same class wide type.
11185 -- Update attributes of the class-wide type which depend on
11186 -- the full declaration.
11188 if Is_Tagged_Type (Priv_T) then
11189 Set_Primitive_Operations (Priv_T, Full_List);
11190 Set_Class_Wide_Type
11191 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
11193 -- Any other attributes should be propagated to C_W ???
11195 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
11200 end Process_Full_View;
11202 -----------------------------------
11203 -- Process_Incomplete_Dependents --
11204 -----------------------------------
11206 procedure Process_Incomplete_Dependents
11208 Full_T : Entity_Id;
11211 Inc_Elmt : Elmt_Id;
11212 Priv_Dep : Entity_Id;
11213 New_Subt : Entity_Id;
11215 Disc_Constraint : Elist_Id;
11218 if No (Private_Dependents (Inc_T)) then
11222 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
11224 -- Itypes that may be generated by the completion of an incomplete
11225 -- subtype are not used by the back-end and not attached to the tree.
11226 -- They are created only for constraint-checking purposes.
11229 while Present (Inc_Elmt) loop
11230 Priv_Dep := Node (Inc_Elmt);
11232 if Ekind (Priv_Dep) = E_Subprogram_Type then
11234 -- An Access_To_Subprogram type may have a return type or a
11235 -- parameter type that is incomplete. Replace with the full view.
11237 if Etype (Priv_Dep) = Inc_T then
11238 Set_Etype (Priv_Dep, Full_T);
11242 Formal : Entity_Id;
11245 Formal := First_Formal (Priv_Dep);
11247 while Present (Formal) loop
11249 if Etype (Formal) = Inc_T then
11250 Set_Etype (Formal, Full_T);
11253 Next_Formal (Formal);
11257 elsif Is_Overloadable (Priv_Dep) then
11259 if Is_Tagged_Type (Full_T) then
11261 -- Subprogram has an access parameter whose designated type
11262 -- was incomplete. Reexamine declaration now, because it may
11263 -- be a primitive operation of the full type.
11265 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
11266 Set_Is_Dispatching_Operation (Priv_Dep);
11267 Check_Controlling_Formals (Full_T, Priv_Dep);
11270 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
11272 -- Can happen during processing of a body before the completion
11273 -- of a TA type. Ignore, because spec is also on dependent list.
11277 -- Dependent is a subtype
11280 -- We build a new subtype indication using the full view of the
11281 -- incomplete parent. The discriminant constraints have been
11282 -- elaborated already at the point of the subtype declaration.
11284 New_Subt := Create_Itype (E_Void, N);
11286 if Has_Discriminants (Full_T) then
11287 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
11289 Disc_Constraint := No_Elist;
11292 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
11293 Set_Full_View (Priv_Dep, New_Subt);
11296 Next_Elmt (Inc_Elmt);
11299 end Process_Incomplete_Dependents;
11301 --------------------------------
11302 -- Process_Range_Expr_In_Decl --
11303 --------------------------------
11305 procedure Process_Range_Expr_In_Decl
11308 Related_Nod : Node_Id;
11309 Check_List : List_Id := Empty_List;
11310 R_Check_Off : Boolean := False)
11313 R_Checks : Check_Result;
11314 Type_Decl : Node_Id;
11315 Def_Id : Entity_Id;
11318 Analyze_And_Resolve (R, Base_Type (T));
11320 if Nkind (R) = N_Range then
11321 Lo := Low_Bound (R);
11322 Hi := High_Bound (R);
11324 -- If there were errors in the declaration, try and patch up some
11325 -- common mistakes in the bounds. The cases handled are literals
11326 -- which are Integer where the expected type is Real and vice versa.
11327 -- These corrections allow the compilation process to proceed further
11328 -- along since some basic assumptions of the format of the bounds
11331 if Etype (R) = Any_Type then
11333 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
11335 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
11337 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
11339 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
11341 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
11343 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
11345 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
11347 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
11354 -- If the bounds of the range have been mistakenly given as
11355 -- string literals (perhaps in place of character literals),
11356 -- then an error has already been reported, but we rewrite
11357 -- the string literal as a bound of the range's type to
11358 -- avoid blowups in later processing that looks at static
11361 if Nkind (Lo) = N_String_Literal then
11363 Make_Attribute_Reference (Sloc (Lo),
11364 Attribute_Name => Name_First,
11365 Prefix => New_Reference_To (T, Sloc (Lo))));
11366 Analyze_And_Resolve (Lo);
11369 if Nkind (Hi) = N_String_Literal then
11371 Make_Attribute_Reference (Sloc (Hi),
11372 Attribute_Name => Name_First,
11373 Prefix => New_Reference_To (T, Sloc (Hi))));
11374 Analyze_And_Resolve (Hi);
11377 -- If bounds aren't scalar at this point then exit, avoiding
11378 -- problems with further processing of the range in this procedure.
11380 if not Is_Scalar_Type (Etype (Lo)) then
11384 -- Resolve (actually Sem_Eval) has checked that the bounds are in
11385 -- then range of the base type. Here we check whether the bounds
11386 -- are in the range of the subtype itself. Note that if the bounds
11387 -- represent the null range the Constraint_Error exception should
11390 -- ??? The following code should be cleaned up as follows
11391 -- 1. The Is_Null_Range (Lo, Hi) test should disapper since it
11392 -- is done in the call to Range_Check (R, T); below
11393 -- 2. The use of R_Check_Off should be investigated and possibly
11394 -- removed, this would clean up things a bit.
11396 if Is_Null_Range (Lo, Hi) then
11400 -- We use a flag here instead of suppressing checks on the
11401 -- type because the type we check against isn't necessarily the
11402 -- place where we put the check.
11404 if not R_Check_Off then
11405 R_Checks := Range_Check (R, T);
11406 Type_Decl := Parent (R);
11408 -- Look up tree to find an appropriate insertion point.
11409 -- This seems really junk code, and very brittle, couldn't
11410 -- we just use an insert actions call of some kind ???
11412 while Present (Type_Decl) and then not
11413 (Nkind (Type_Decl) = N_Full_Type_Declaration
11415 Nkind (Type_Decl) = N_Subtype_Declaration
11417 Nkind (Type_Decl) = N_Loop_Statement
11419 Nkind (Type_Decl) = N_Task_Type_Declaration
11421 Nkind (Type_Decl) = N_Single_Task_Declaration
11423 Nkind (Type_Decl) = N_Protected_Type_Declaration
11425 Nkind (Type_Decl) = N_Single_Protected_Declaration)
11427 Type_Decl := Parent (Type_Decl);
11430 -- Why would Type_Decl not be present??? Without this test,
11431 -- short regression tests fail.
11433 if Present (Type_Decl) then
11434 if Nkind (Type_Decl) = N_Loop_Statement then
11436 Indic : Node_Id := Parent (R);
11438 while Present (Indic) and then not
11439 (Nkind (Indic) = N_Subtype_Indication)
11441 Indic := Parent (Indic);
11444 if Present (Indic) then
11445 Def_Id := Etype (Subtype_Mark (Indic));
11447 Insert_Range_Checks
11453 Do_Before => True);
11457 Def_Id := Defining_Identifier (Type_Decl);
11459 if (Ekind (Def_Id) = E_Record_Type
11460 and then Depends_On_Discriminant (R))
11462 (Ekind (Def_Id) = E_Protected_Type
11463 and then Has_Discriminants (Def_Id))
11465 Append_Range_Checks
11466 (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
11469 Insert_Range_Checks
11470 (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
11479 Get_Index_Bounds (R, Lo, Hi);
11481 if Expander_Active then
11482 Force_Evaluation (Lo);
11483 Force_Evaluation (Hi);
11486 end Process_Range_Expr_In_Decl;
11488 --------------------------------------
11489 -- Process_Real_Range_Specification --
11490 --------------------------------------
11492 procedure Process_Real_Range_Specification (Def : Node_Id) is
11493 Spec : constant Node_Id := Real_Range_Specification (Def);
11496 Err : Boolean := False;
11498 procedure Analyze_Bound (N : Node_Id);
11499 -- Analyze and check one bound
11501 procedure Analyze_Bound (N : Node_Id) is
11503 Analyze_And_Resolve (N, Any_Real);
11505 if not Is_OK_Static_Expression (N) then
11507 ("bound in real type definition is not static", N);
11513 if Present (Spec) then
11514 Lo := Low_Bound (Spec);
11515 Hi := High_Bound (Spec);
11516 Analyze_Bound (Lo);
11517 Analyze_Bound (Hi);
11519 -- If error, clear away junk range specification
11522 Set_Real_Range_Specification (Def, Empty);
11525 end Process_Real_Range_Specification;
11527 ---------------------
11528 -- Process_Subtype --
11529 ---------------------
11531 function Process_Subtype
11533 Related_Nod : Node_Id;
11534 Related_Id : Entity_Id := Empty;
11535 Suffix : Character := ' ')
11539 Def_Id : Entity_Id;
11540 Full_View_Id : Entity_Id;
11541 Subtype_Mark_Id : Entity_Id;
11542 N_Dynamic_Ityp : Node_Id := Empty;
11545 -- Case of constraint present, so that we have an N_Subtype_Indication
11546 -- node (this node is created only if constraints are present).
11548 if Nkind (S) = N_Subtype_Indication then
11549 Find_Type (Subtype_Mark (S));
11551 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
11553 (Nkind (Parent (S)) = N_Subtype_Declaration
11555 Is_Itype (Defining_Identifier (Parent (S))))
11557 Check_Incomplete (Subtype_Mark (S));
11561 Subtype_Mark_Id := Entity (Subtype_Mark (S));
11563 if Is_Unchecked_Union (Subtype_Mark_Id)
11564 and then Comes_From_Source (Related_Nod)
11567 ("cannot create subtype of Unchecked_Union", Related_Nod);
11570 -- Explicit subtype declaration case
11572 if Nkind (P) = N_Subtype_Declaration then
11573 Def_Id := Defining_Identifier (P);
11575 -- Explicit derived type definition case
11577 elsif Nkind (P) = N_Derived_Type_Definition then
11578 Def_Id := Defining_Identifier (Parent (P));
11580 -- Implicit case, the Def_Id must be created as an implicit type.
11581 -- The one exception arises in the case of concurrent types,
11582 -- array and access types, where other subsidiary implicit types
11583 -- may be created and must appear before the main implicit type.
11584 -- In these cases we leave Def_Id set to Empty as a signal that
11585 -- Create_Itype has not yet been called to create Def_Id.
11588 if Is_Array_Type (Subtype_Mark_Id)
11589 or else Is_Concurrent_Type (Subtype_Mark_Id)
11590 or else Is_Access_Type (Subtype_Mark_Id)
11594 -- For the other cases, we create a new unattached Itype,
11595 -- and set the indication to ensure it gets attached later.
11599 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11602 N_Dynamic_Ityp := Related_Nod;
11605 -- If the kind of constraint is invalid for this kind of type,
11606 -- then give an error, and then pretend no constraint was given.
11608 if not Is_Valid_Constraint_Kind
11609 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
11612 ("incorrect constraint for this kind of type", Constraint (S));
11614 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
11616 -- Make recursive call, having got rid of the bogus constraint
11618 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
11621 -- Remaining processing depends on type
11623 case Ekind (Subtype_Mark_Id) is
11625 when Access_Kind =>
11626 Constrain_Access (Def_Id, S, Related_Nod);
11629 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
11631 when Decimal_Fixed_Point_Kind =>
11632 Constrain_Decimal (Def_Id, S, N_Dynamic_Ityp);
11634 when Enumeration_Kind =>
11635 Constrain_Enumeration (Def_Id, S, N_Dynamic_Ityp);
11637 when Ordinary_Fixed_Point_Kind =>
11638 Constrain_Ordinary_Fixed (Def_Id, S, N_Dynamic_Ityp);
11641 Constrain_Float (Def_Id, S, N_Dynamic_Ityp);
11643 when Integer_Kind =>
11644 Constrain_Integer (Def_Id, S, N_Dynamic_Ityp);
11646 when E_Record_Type |
11649 E_Incomplete_Type =>
11650 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11652 when Private_Kind =>
11653 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
11654 Set_Private_Dependents (Def_Id, New_Elmt_List);
11656 -- In case of an invalid constraint prevent further processing
11657 -- since the type constructed is missing expected fields.
11659 if Etype (Def_Id) = Any_Type then
11663 -- If the full view is that of a task with discriminants,
11664 -- we must constrain both the concurrent type and its
11665 -- corresponding record type. Otherwise we will just propagate
11666 -- the constraint to the full view, if available.
11668 if Present (Full_View (Subtype_Mark_Id))
11669 and then Has_Discriminants (Subtype_Mark_Id)
11670 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
11673 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11675 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
11676 Constrain_Concurrent (Full_View_Id, S,
11677 Related_Nod, Related_Id, Suffix);
11678 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
11679 Set_Full_View (Def_Id, Full_View_Id);
11682 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
11685 when Concurrent_Kind =>
11686 Constrain_Concurrent (Def_Id, S,
11687 Related_Nod, Related_Id, Suffix);
11690 Error_Msg_N ("invalid subtype mark in subtype indication", S);
11693 -- Size and Convention are always inherited from the base type
11695 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
11696 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
11700 -- Case of no constraints present
11704 Check_Incomplete (S);
11707 end Process_Subtype;
11709 -----------------------------
11710 -- Record_Type_Declaration --
11711 -----------------------------
11713 procedure Record_Type_Declaration (T : Entity_Id; N : Node_Id) is
11714 Def : constant Node_Id := Type_Definition (N);
11715 Range_Checks_Suppressed_Flag : Boolean := False;
11717 Is_Tagged : Boolean;
11718 Tag_Comp : Entity_Id;
11721 -- The flag Is_Tagged_Type might have already been set by Find_Type_Name
11722 -- if it detected an error for declaration T. This arises in the case of
11723 -- private tagged types where the full view omits the word tagged.
11725 Is_Tagged := Tagged_Present (Def)
11726 or else (Errors_Detected > 0 and then Is_Tagged_Type (T));
11728 -- Records constitute a scope for the component declarations within.
11729 -- The scope is created prior to the processing of these declarations.
11730 -- Discriminants are processed first, so that they are visible when
11731 -- processing the other components. The Ekind of the record type itself
11732 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
11734 -- Enter record scope
11738 -- These flags must be initialized before calling Process_Discriminants
11739 -- because this routine makes use of them.
11741 Set_Is_Tagged_Type (T, Is_Tagged);
11742 Set_Is_Limited_Record (T, Limited_Present (Def));
11744 -- Type is abstract if full declaration carries keyword, or if
11745 -- previous partial view did.
11747 Set_Is_Abstract (T, Is_Abstract (T) or else Abstract_Present (Def));
11749 Set_Ekind (T, E_Record_Type);
11751 Init_Size_Align (T);
11753 Set_Girder_Constraint (T, No_Elist);
11755 -- If an incomplete or private type declaration was already given for
11756 -- the type, then this scope already exists, and the discriminants have
11757 -- been declared within. We must verify that the full declaration
11758 -- matches the incomplete one.
11760 Check_Or_Process_Discriminants (N, T);
11762 Set_Is_Constrained (T, not Has_Discriminants (T));
11763 Set_Has_Delayed_Freeze (T, True);
11765 -- For tagged types add a manually analyzed component corresponding
11766 -- to the component _tag, the corresponding piece of tree will be
11767 -- expanded as part of the freezing actions if it is not a CPP_Class.
11770 -- Do not add the tag unless we are in expansion mode.
11772 if Expander_Active then
11773 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
11774 Enter_Name (Tag_Comp);
11776 Set_Is_Tag (Tag_Comp);
11777 Set_Ekind (Tag_Comp, E_Component);
11778 Set_Etype (Tag_Comp, RTE (RE_Tag));
11779 Set_DT_Entry_Count (Tag_Comp, No_Uint);
11780 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
11781 Init_Component_Location (Tag_Comp);
11784 Make_Class_Wide_Type (T);
11785 Set_Primitive_Operations (T, New_Elmt_List);
11788 -- We must suppress range checks when processing the components
11789 -- of a record in the presence of discriminants, since we don't
11790 -- want spurious checks to be generated during their analysis, but
11791 -- must reset the Suppress_Range_Checks flags after having procesed
11792 -- the record definition.
11794 if Has_Discriminants (T) and then not Suppress_Range_Checks (T) then
11795 Set_Suppress_Range_Checks (T, True);
11796 Range_Checks_Suppressed_Flag := True;
11799 Record_Type_Definition (Def, T);
11801 if Range_Checks_Suppressed_Flag then
11802 Set_Suppress_Range_Checks (T, False);
11803 Range_Checks_Suppressed_Flag := False;
11806 -- Exit from record scope
11809 end Record_Type_Declaration;
11811 ----------------------------
11812 -- Record_Type_Definition --
11813 ----------------------------
11815 procedure Record_Type_Definition (Def : Node_Id; T : Entity_Id) is
11816 Component : Entity_Id;
11817 Ctrl_Components : Boolean := False;
11818 Final_Storage_Only : Boolean := not Is_Controlled (T);
11821 -- If the component list of a record type is defined by the reserved
11822 -- word null and there is no discriminant part, then the record type has
11823 -- no components and all records of the type are null records (RM 3.7)
11824 -- This procedure is also called to process the extension part of a
11825 -- record extension, in which case the current scope may have inherited
11829 or else No (Component_List (Def))
11830 or else Null_Present (Component_List (Def))
11835 Analyze_Declarations (Component_Items (Component_List (Def)));
11837 if Present (Variant_Part (Component_List (Def))) then
11838 Analyze (Variant_Part (Component_List (Def)));
11842 -- After completing the semantic analysis of the record definition,
11843 -- record components, both new and inherited, are accessible. Set
11844 -- their kind accordingly.
11846 Component := First_Entity (Current_Scope);
11847 while Present (Component) loop
11849 if Ekind (Component) = E_Void then
11850 Set_Ekind (Component, E_Component);
11851 Init_Component_Location (Component);
11854 if Has_Task (Etype (Component)) then
11858 if Ekind (Component) /= E_Component then
11861 elsif Has_Controlled_Component (Etype (Component))
11862 or else (Chars (Component) /= Name_uParent
11863 and then Is_Controlled (Etype (Component)))
11865 Set_Has_Controlled_Component (T, True);
11866 Final_Storage_Only := Final_Storage_Only
11867 and then Finalize_Storage_Only (Etype (Component));
11868 Ctrl_Components := True;
11871 Next_Entity (Component);
11874 -- A type is Finalize_Storage_Only only if all its controlled
11875 -- components are so.
11877 if Ctrl_Components then
11878 Set_Finalize_Storage_Only (T, Final_Storage_Only);
11881 if Present (Def) then
11882 Process_End_Label (Def, 'e');
11884 end Record_Type_Definition;
11886 ---------------------
11887 -- Set_Fixed_Range --
11888 ---------------------
11890 -- The range for fixed-point types is complicated by the fact that we
11891 -- do not know the exact end points at the time of the declaration. This
11892 -- is true for three reasons:
11894 -- A size clause may affect the fudging of the end-points
11895 -- A small clause may affect the values of the end-points
11896 -- We try to include the end-points if it does not affect the size
11898 -- This means that the actual end-points must be established at the
11899 -- point when the type is frozen. Meanwhile, we first narrow the range
11900 -- as permitted (so that it will fit if necessary in a small specified
11901 -- size), and then build a range subtree with these narrowed bounds.
11903 -- Set_Fixed_Range constructs the range from real literal values, and
11904 -- sets the range as the Scalar_Range of the given fixed-point type
11907 -- The parent of this range is set to point to the entity so that it
11908 -- is properly hooked into the tree (unlike normal Scalar_Range entries
11909 -- for other scalar types, which are just pointers to the range in the
11910 -- original tree, this would otherwise be an orphan).
11912 -- The tree is left unanalyzed. When the type is frozen, the processing
11913 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
11914 -- analyzed, and uses this as an indication that it should complete
11915 -- work on the range (it will know the final small and size values).
11917 procedure Set_Fixed_Range
11923 S : constant Node_Id :=
11925 Low_Bound => Make_Real_Literal (Loc, Lo),
11926 High_Bound => Make_Real_Literal (Loc, Hi));
11929 Set_Scalar_Range (E, S);
11931 end Set_Fixed_Range;
11933 --------------------------------------------------------
11934 -- Set_Girder_Constraint_From_Discriminant_Constraint --
11935 --------------------------------------------------------
11937 procedure Set_Girder_Constraint_From_Discriminant_Constraint
11941 -- Make sure set if encountered during
11942 -- Expand_To_Girder_Constraint
11944 Set_Girder_Constraint (E, No_Elist);
11946 -- Give it the right value
11948 if Is_Constrained (E) and then Has_Discriminants (E) then
11949 Set_Girder_Constraint (E,
11950 Expand_To_Girder_Constraint (E, Discriminant_Constraint (E)));
11953 end Set_Girder_Constraint_From_Discriminant_Constraint;
11955 ----------------------------------
11956 -- Set_Scalar_Range_For_Subtype --
11957 ----------------------------------
11959 procedure Set_Scalar_Range_For_Subtype
11960 (Def_Id : Entity_Id;
11963 Related_Nod : Node_Id)
11965 Kind : constant Entity_Kind := Ekind (Def_Id);
11967 Set_Scalar_Range (Def_Id, R);
11969 -- We need to link the range into the tree before resolving it so
11970 -- that types that are referenced, including importantly the subtype
11971 -- itself, are properly frozen (Freeze_Expression requires that the
11972 -- expression be properly linked into the tree). Of course if it is
11973 -- already linked in, then we do not disturb the current link.
11975 if No (Parent (R)) then
11976 Set_Parent (R, Def_Id);
11979 -- Reset the kind of the subtype during analysis of the range, to
11980 -- catch possible premature use in the bounds themselves.
11982 Set_Ekind (Def_Id, E_Void);
11983 Process_Range_Expr_In_Decl (R, Subt, Related_Nod);
11984 Set_Ekind (Def_Id, Kind);
11986 end Set_Scalar_Range_For_Subtype;
11988 -------------------------------------
11989 -- Signed_Integer_Type_Declaration --
11990 -------------------------------------
11992 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
11993 Implicit_Base : Entity_Id;
11994 Base_Typ : Entity_Id;
11997 Errs : Boolean := False;
12001 function Can_Derive_From (E : Entity_Id) return Boolean;
12002 -- Determine whether given bounds allow derivation from specified type
12004 procedure Check_Bound (Expr : Node_Id);
12005 -- Check bound to make sure it is integral and static. If not, post
12006 -- appropriate error message and set Errs flag
12008 function Can_Derive_From (E : Entity_Id) return Boolean is
12009 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
12010 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
12013 -- Note we check both bounds against both end values, to deal with
12014 -- strange types like ones with a range of 0 .. -12341234.
12016 return Lo <= Lo_Val and then Lo_Val <= Hi
12018 Lo <= Hi_Val and then Hi_Val <= Hi;
12019 end Can_Derive_From;
12021 procedure Check_Bound (Expr : Node_Id) is
12023 -- If a range constraint is used as an integer type definition, each
12024 -- bound of the range must be defined by a static expression of some
12025 -- integer type, but the two bounds need not have the same integer
12026 -- type (Negative bounds are allowed.) (RM 3.5.4)
12028 if not Is_Integer_Type (Etype (Expr)) then
12030 ("integer type definition bounds must be of integer type", Expr);
12033 elsif not Is_OK_Static_Expression (Expr) then
12035 ("non-static expression used for integer type bound", Expr);
12038 -- The bounds are folded into literals, and we set their type to be
12039 -- universal, to avoid typing difficulties: we cannot set the type
12040 -- of the literal to the new type, because this would be a forward
12041 -- reference for the back end, and if the original type is user-
12042 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
12045 if Is_Entity_Name (Expr) then
12046 Fold_Uint (Expr, Expr_Value (Expr));
12049 Set_Etype (Expr, Universal_Integer);
12053 -- Start of processing for Signed_Integer_Type_Declaration
12056 -- Create an anonymous base type
12059 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
12061 -- Analyze and check the bounds, they can be of any integer type
12063 Lo := Low_Bound (Def);
12064 Hi := High_Bound (Def);
12065 Analyze_And_Resolve (Lo, Any_Integer);
12066 Analyze_And_Resolve (Hi, Any_Integer);
12072 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12073 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12076 -- Find type to derive from
12078 Lo_Val := Expr_Value (Lo);
12079 Hi_Val := Expr_Value (Hi);
12081 if Can_Derive_From (Standard_Short_Short_Integer) then
12082 Base_Typ := Base_Type (Standard_Short_Short_Integer);
12084 elsif Can_Derive_From (Standard_Short_Integer) then
12085 Base_Typ := Base_Type (Standard_Short_Integer);
12087 elsif Can_Derive_From (Standard_Integer) then
12088 Base_Typ := Base_Type (Standard_Integer);
12090 elsif Can_Derive_From (Standard_Long_Integer) then
12091 Base_Typ := Base_Type (Standard_Long_Integer);
12093 elsif Can_Derive_From (Standard_Long_Long_Integer) then
12094 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12097 Base_Typ := Base_Type (Standard_Long_Long_Integer);
12098 Error_Msg_N ("integer type definition bounds out of range", Def);
12099 Hi := Type_High_Bound (Standard_Long_Long_Integer);
12100 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
12103 -- Complete both implicit base and declared first subtype entities
12105 Set_Etype (Implicit_Base, Base_Typ);
12106 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
12107 Set_Size_Info (Implicit_Base, (Base_Typ));
12108 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
12109 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
12111 Set_Ekind (T, E_Signed_Integer_Subtype);
12112 Set_Etype (T, Implicit_Base);
12114 Set_Size_Info (T, (Implicit_Base));
12115 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
12116 Set_Scalar_Range (T, Def);
12117 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
12118 Set_Is_Constrained (T);
12120 end Signed_Integer_Type_Declaration;
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