1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Elists; use Elists;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Eval_Fat; use Eval_Fat;
33 with Exp_Ch3; use Exp_Ch3;
34 with Exp_Ch9; use Exp_Ch9;
35 with Exp_Disp; use Exp_Disp;
36 with Exp_Dist; use Exp_Dist;
37 with Exp_Tss; use Exp_Tss;
38 with Exp_Util; use Exp_Util;
39 with Fname; use Fname;
40 with Freeze; use Freeze;
41 with Itypes; use Itypes;
42 with Layout; use Layout;
44 with Lib.Xref; use Lib.Xref;
45 with Namet; use Namet;
46 with Nmake; use Nmake;
48 with Restrict; use Restrict;
49 with Rident; use Rident;
50 with Rtsfind; use Rtsfind;
52 with Sem_Aux; use Sem_Aux;
53 with Sem_Case; use Sem_Case;
54 with Sem_Cat; use Sem_Cat;
55 with Sem_Ch6; use Sem_Ch6;
56 with Sem_Ch7; use Sem_Ch7;
57 with Sem_Ch8; use Sem_Ch8;
58 with Sem_Ch13; use Sem_Ch13;
59 with Sem_Dim; use Sem_Dim;
60 with Sem_Disp; use Sem_Disp;
61 with Sem_Dist; use Sem_Dist;
62 with Sem_Elim; use Sem_Elim;
63 with Sem_Eval; use Sem_Eval;
64 with Sem_Mech; use Sem_Mech;
65 with Sem_Prag; use Sem_Prag;
66 with Sem_Res; use Sem_Res;
67 with Sem_Smem; use Sem_Smem;
68 with Sem_Type; use Sem_Type;
69 with Sem_Util; use Sem_Util;
70 with Sem_Warn; use Sem_Warn;
71 with Stand; use Stand;
72 with Sinfo; use Sinfo;
73 with Sinput; use Sinput;
74 with Snames; use Snames;
75 with Targparm; use Targparm;
76 with Tbuild; use Tbuild;
77 with Ttypes; use Ttypes;
78 with Uintp; use Uintp;
79 with Urealp; use Urealp;
81 package body Sem_Ch3 is
83 -----------------------
84 -- Local Subprograms --
85 -----------------------
87 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id);
88 -- Ada 2005 (AI-251): Add the tag components corresponding to all the
89 -- abstract interface types implemented by a record type or a derived
92 procedure Build_Derived_Type
94 Parent_Type : Entity_Id;
95 Derived_Type : Entity_Id;
96 Is_Completion : Boolean;
97 Derive_Subps : Boolean := True);
98 -- Create and decorate a Derived_Type given the Parent_Type entity. N is
99 -- the N_Full_Type_Declaration node containing the derived type definition.
100 -- Parent_Type is the entity for the parent type in the derived type
101 -- definition and Derived_Type the actual derived type. Is_Completion must
102 -- be set to False if Derived_Type is the N_Defining_Identifier node in N
103 -- (i.e. Derived_Type = Defining_Identifier (N)). In this case N is not the
104 -- completion of a private type declaration. If Is_Completion is set to
105 -- True, N is the completion of a private type declaration and Derived_Type
106 -- is different from the defining identifier inside N (i.e. Derived_Type /=
107 -- Defining_Identifier (N)). Derive_Subps indicates whether the parent
108 -- subprograms should be derived. The only case where this parameter is
109 -- False is when Build_Derived_Type is recursively called to process an
110 -- implicit derived full type for a type derived from a private type (in
111 -- that case the subprograms must only be derived for the private view of
114 -- ??? These flags need a bit of re-examination and re-documentation:
115 -- ??? are they both necessary (both seem related to the recursion)?
117 procedure Build_Derived_Access_Type
119 Parent_Type : Entity_Id;
120 Derived_Type : Entity_Id);
121 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
122 -- create an implicit base if the parent type is constrained or if the
123 -- subtype indication has a constraint.
125 procedure Build_Derived_Array_Type
127 Parent_Type : Entity_Id;
128 Derived_Type : Entity_Id);
129 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
130 -- create an implicit base if the parent type is constrained or if the
131 -- subtype indication has a constraint.
133 procedure Build_Derived_Concurrent_Type
135 Parent_Type : Entity_Id;
136 Derived_Type : Entity_Id);
137 -- Subsidiary procedure to Build_Derived_Type. For a derived task or
138 -- protected type, inherit entries and protected subprograms, check
139 -- legality of discriminant constraints if any.
141 procedure Build_Derived_Enumeration_Type
143 Parent_Type : Entity_Id;
144 Derived_Type : Entity_Id);
145 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
146 -- type, we must create a new list of literals. Types derived from
147 -- Character and [Wide_]Wide_Character are special-cased.
149 procedure Build_Derived_Numeric_Type
151 Parent_Type : Entity_Id;
152 Derived_Type : Entity_Id);
153 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
154 -- an anonymous base type, and propagate constraint to subtype if needed.
156 procedure Build_Derived_Private_Type
158 Parent_Type : Entity_Id;
159 Derived_Type : Entity_Id;
160 Is_Completion : Boolean;
161 Derive_Subps : Boolean := True);
162 -- Subsidiary procedure to Build_Derived_Type. This procedure is complex
163 -- because the parent may or may not have a completion, and the derivation
164 -- may itself be a completion.
166 procedure Build_Derived_Record_Type
168 Parent_Type : Entity_Id;
169 Derived_Type : Entity_Id;
170 Derive_Subps : Boolean := True);
171 -- Subsidiary procedure for Build_Derived_Type and
172 -- Analyze_Private_Extension_Declaration used for tagged and untagged
173 -- record types. All parameters are as in Build_Derived_Type except that
174 -- N, in addition to being an N_Full_Type_Declaration node, can also be an
175 -- N_Private_Extension_Declaration node. See the definition of this routine
176 -- for much more info. Derive_Subps indicates whether subprograms should
177 -- be derived from the parent type. The only case where Derive_Subps is
178 -- False is for an implicit derived full type for a type derived from a
179 -- private type (see Build_Derived_Type).
181 procedure Build_Discriminal (Discrim : Entity_Id);
182 -- Create the discriminal corresponding to discriminant Discrim, that is
183 -- the parameter corresponding to Discrim to be used in initialization
184 -- procedures for the type where Discrim is a discriminant. Discriminals
185 -- are not used during semantic analysis, and are not fully defined
186 -- entities until expansion. Thus they are not given a scope until
187 -- initialization procedures are built.
189 function Build_Discriminant_Constraints
192 Derived_Def : Boolean := False) return Elist_Id;
193 -- Validate discriminant constraints and return the list of the constraints
194 -- in order of discriminant declarations, where T is the discriminated
195 -- unconstrained type. Def is the N_Subtype_Indication node where the
196 -- discriminants constraints for T are specified. Derived_Def is True
197 -- when building the discriminant constraints in a derived type definition
198 -- of the form "type D (...) is new T (xxx)". In this case T is the parent
199 -- type and Def is the constraint "(xxx)" on T and this routine sets the
200 -- Corresponding_Discriminant field of the discriminants in the derived
201 -- type D to point to the corresponding discriminants in the parent type T.
203 procedure Build_Discriminated_Subtype
207 Related_Nod : Node_Id;
208 For_Access : Boolean := False);
209 -- Subsidiary procedure to Constrain_Discriminated_Type and to
210 -- Process_Incomplete_Dependents. Given
212 -- T (a possibly discriminated base type)
213 -- Def_Id (a very partially built subtype for T),
215 -- the call completes Def_Id to be the appropriate E_*_Subtype.
217 -- The Elist is the list of discriminant constraints if any (it is set
218 -- to No_Elist if T is not a discriminated type, and to an empty list if
219 -- T has discriminants but there are no discriminant constraints). The
220 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
221 -- The For_Access says whether or not this subtype is really constraining
222 -- an access type. That is its sole purpose is the designated type of an
223 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
224 -- is built to avoid freezing T when the access subtype is frozen.
226 function Build_Scalar_Bound
229 Der_T : Entity_Id) return Node_Id;
230 -- The bounds of a derived scalar type are conversions of the bounds of
231 -- the parent type. Optimize the representation if the bounds are literals.
232 -- Needs a more complete spec--what are the parameters exactly, and what
233 -- exactly is the returned value, and how is Bound affected???
235 procedure Build_Underlying_Full_View
239 -- If the completion of a private type is itself derived from a private
240 -- type, or if the full view of a private subtype is itself private, the
241 -- back-end has no way to compute the actual size of this type. We build
242 -- an internal subtype declaration of the proper parent type to convey
243 -- this information. This extra mechanism is needed because a full
244 -- view cannot itself have a full view (it would get clobbered during
247 procedure Check_Access_Discriminant_Requires_Limited
250 -- Check the restriction that the type to which an access discriminant
251 -- belongs must be a concurrent type or a descendant of a type with
252 -- the reserved word 'limited' in its declaration.
254 procedure Check_Anonymous_Access_Components
258 Comp_List : Node_Id);
259 -- Ada 2005 AI-382: an access component in a record definition can refer to
260 -- the enclosing record, in which case it denotes the type itself, and not
261 -- the current instance of the type. We create an anonymous access type for
262 -- the component, and flag it as an access to a component, so accessibility
263 -- checks are properly performed on it. The declaration of the access type
264 -- is placed ahead of that of the record to prevent order-of-elaboration
265 -- circularity issues in Gigi. We create an incomplete type for the record
266 -- declaration, which is the designated type of the anonymous access.
268 procedure Check_Delta_Expression (E : Node_Id);
269 -- Check that the expression represented by E is suitable for use as a
270 -- delta expression, i.e. it is of real type and is static.
272 procedure Check_Digits_Expression (E : Node_Id);
273 -- Check that the expression represented by E is suitable for use as a
274 -- digits expression, i.e. it is of integer type, positive and static.
276 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
277 -- Validate the initialization of an object declaration. T is the required
278 -- type, and Exp is the initialization expression.
280 procedure Check_Interfaces (N : Node_Id; Def : Node_Id);
281 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
283 procedure Check_Or_Process_Discriminants
286 Prev : Entity_Id := Empty);
287 -- If N is the full declaration of the completion T of an incomplete or
288 -- private type, check its discriminants (which are already known to be
289 -- conformant with those of the partial view, see Find_Type_Name),
290 -- otherwise process them. Prev is the entity of the partial declaration,
293 procedure Check_Real_Bound (Bound : Node_Id);
294 -- Check given bound for being of real type and static. If not, post an
295 -- appropriate message, and rewrite the bound with the real literal zero.
297 procedure Constant_Redeclaration
301 -- Various checks on legality of full declaration of deferred constant.
302 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
303 -- node. The caller has not yet set any attributes of this entity.
305 function Contain_Interface
307 Ifaces : Elist_Id) return Boolean;
308 -- Ada 2005: Determine whether Iface is present in the list Ifaces
310 procedure Convert_Scalar_Bounds
312 Parent_Type : Entity_Id;
313 Derived_Type : Entity_Id;
315 -- For derived scalar types, convert the bounds in the type definition to
316 -- the derived type, and complete their analysis. Given a constraint of the
317 -- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with
318 -- T'Base, the parent_type. The bounds of the derived type (the anonymous
319 -- base) are copies of Lo and Hi. Finally, the bounds of the derived
320 -- subtype are conversions of those bounds to the derived_type, so that
321 -- their typing is consistent.
323 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
324 -- Copies attributes from array base type T2 to array base type T1. Copies
325 -- only attributes that apply to base types, but not subtypes.
327 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
328 -- Copies attributes from array subtype T2 to array subtype T1. Copies
329 -- attributes that apply to both subtypes and base types.
331 procedure Create_Constrained_Components
335 Constraints : Elist_Id);
336 -- Build the list of entities for a constrained discriminated record
337 -- subtype. If a component depends on a discriminant, replace its subtype
338 -- using the discriminant values in the discriminant constraint. Subt
339 -- is the defining identifier for the subtype whose list of constrained
340 -- entities we will create. Decl_Node is the type declaration node where
341 -- we will attach all the itypes created. Typ is the base discriminated
342 -- type for the subtype Subt. Constraints is the list of discriminant
343 -- constraints for Typ.
345 function Constrain_Component_Type
347 Constrained_Typ : Entity_Id;
348 Related_Node : Node_Id;
350 Constraints : Elist_Id) return Entity_Id;
351 -- Given a discriminated base type Typ, a list of discriminant constraint
352 -- Constraints for Typ and a component of Typ, with type Compon_Type,
353 -- create and return the type corresponding to Compon_type where all
354 -- discriminant references are replaced with the corresponding constraint.
355 -- If no discriminant references occur in Compon_Typ then return it as is.
356 -- Constrained_Typ is the final constrained subtype to which the
357 -- constrained Compon_Type belongs. Related_Node is the node where we will
358 -- attach all the itypes created.
360 -- Above description is confused, what is Compon_Type???
362 procedure Constrain_Access
363 (Def_Id : in out Entity_Id;
365 Related_Nod : Node_Id);
366 -- Apply a list of constraints to an access type. If Def_Id is empty, it is
367 -- an anonymous type created for a subtype indication. In that case it is
368 -- created in the procedure and attached to Related_Nod.
370 procedure Constrain_Array
371 (Def_Id : in out Entity_Id;
373 Related_Nod : Node_Id;
374 Related_Id : Entity_Id;
376 -- Apply a list of index constraints to an unconstrained array type. The
377 -- first parameter is the entity for the resulting subtype. A value of
378 -- Empty for Def_Id indicates that an implicit type must be created, but
379 -- creation is delayed (and must be done by this procedure) because other
380 -- subsidiary implicit types must be created first (which is why Def_Id
381 -- is an in/out parameter). The second parameter is a subtype indication
382 -- node for the constrained array to be created (e.g. something of the
383 -- form string (1 .. 10)). Related_Nod gives the place where this type
384 -- has to be inserted in the tree. The Related_Id and Suffix parameters
385 -- are used to build the associated Implicit type name.
387 procedure Constrain_Concurrent
388 (Def_Id : in out Entity_Id;
390 Related_Nod : Node_Id;
391 Related_Id : Entity_Id;
393 -- Apply list of discriminant constraints to an unconstrained concurrent
396 -- SI is the N_Subtype_Indication node containing the constraint and
397 -- the unconstrained type to constrain.
399 -- Def_Id is the entity for the resulting constrained subtype. A value
400 -- of Empty for Def_Id indicates that an implicit type must be created,
401 -- but creation is delayed (and must be done by this procedure) because
402 -- other subsidiary implicit types must be created first (which is why
403 -- Def_Id is an in/out parameter).
405 -- Related_Nod gives the place where this type has to be inserted
408 -- The last two arguments are used to create its external name if needed.
410 function Constrain_Corresponding_Record
411 (Prot_Subt : Entity_Id;
412 Corr_Rec : Entity_Id;
413 Related_Nod : Node_Id;
414 Related_Id : Entity_Id) return Entity_Id;
415 -- When constraining a protected type or task type with discriminants,
416 -- constrain the corresponding record with the same discriminant values.
418 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
419 -- Constrain a decimal fixed point type with a digits constraint and/or a
420 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
422 procedure Constrain_Discriminated_Type
425 Related_Nod : Node_Id;
426 For_Access : Boolean := False);
427 -- Process discriminant constraints of composite type. Verify that values
428 -- have been provided for all discriminants, that the original type is
429 -- unconstrained, and that the types of the supplied expressions match
430 -- the discriminant types. The first three parameters are like in routine
431 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
434 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
435 -- Constrain an enumeration type with a range constraint. This is identical
436 -- to Constrain_Integer, but for the Ekind of the resulting subtype.
438 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
439 -- Constrain a floating point type with either a digits constraint
440 -- and/or a range constraint, building a E_Floating_Point_Subtype.
442 procedure Constrain_Index
445 Related_Nod : Node_Id;
446 Related_Id : Entity_Id;
449 -- Process an index constraint S in a constrained array declaration. The
450 -- constraint can be a subtype name, or a range with or without an explicit
451 -- subtype mark. The index is the corresponding index of the unconstrained
452 -- array. The Related_Id and Suffix parameters are used to build the
453 -- associated Implicit type name.
455 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
456 -- Build subtype of a signed or modular integer type
458 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
459 -- Constrain an ordinary fixed point type with a range constraint, and
460 -- build an E_Ordinary_Fixed_Point_Subtype entity.
462 procedure Copy_And_Swap (Priv, Full : Entity_Id);
463 -- Copy the Priv entity into the entity of its full declaration then swap
464 -- the two entities in such a manner that the former private type is now
465 -- seen as a full type.
467 procedure Decimal_Fixed_Point_Type_Declaration
470 -- Create a new decimal fixed point type, and apply the constraint to
471 -- obtain a subtype of this new type.
473 procedure Complete_Private_Subtype
476 Full_Base : Entity_Id;
477 Related_Nod : Node_Id);
478 -- Complete the implicit full view of a private subtype by setting the
479 -- appropriate semantic fields. If the full view of the parent is a record
480 -- type, build constrained components of subtype.
482 procedure Derive_Progenitor_Subprograms
483 (Parent_Type : Entity_Id;
484 Tagged_Type : Entity_Id);
485 -- Ada 2005 (AI-251): To complete type derivation, collect the primitive
486 -- operations of progenitors of Tagged_Type, and replace the subsidiary
487 -- subtypes with Tagged_Type, to build the specs of the inherited interface
488 -- primitives. The derived primitives are aliased to those of the
489 -- interface. This routine takes care also of transferring to the full view
490 -- subprograms associated with the partial view of Tagged_Type that cover
491 -- interface primitives.
493 procedure Derived_Standard_Character
495 Parent_Type : Entity_Id;
496 Derived_Type : Entity_Id);
497 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
498 -- derivations from types Standard.Character and Standard.Wide_Character.
500 procedure Derived_Type_Declaration
503 Is_Completion : Boolean);
504 -- Process a derived type declaration. Build_Derived_Type is invoked
505 -- to process the actual derived type definition. Parameters N and
506 -- Is_Completion have the same meaning as in Build_Derived_Type.
507 -- T is the N_Defining_Identifier for the entity defined in the
508 -- N_Full_Type_Declaration node N, that is T is the derived type.
510 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
511 -- Insert each literal in symbol table, as an overloadable identifier. Each
512 -- enumeration type is mapped into a sequence of integers, and each literal
513 -- is defined as a constant with integer value. If any of the literals are
514 -- character literals, the type is a character type, which means that
515 -- strings are legal aggregates for arrays of components of the type.
517 function Expand_To_Stored_Constraint
519 Constraint : Elist_Id) return Elist_Id;
520 -- Given a constraint (i.e. a list of expressions) on the discriminants of
521 -- Typ, expand it into a constraint on the stored discriminants and return
522 -- the new list of expressions constraining the stored discriminants.
524 function Find_Type_Of_Object
526 Related_Nod : Node_Id) return Entity_Id;
527 -- Get type entity for object referenced by Obj_Def, attaching the
528 -- implicit types generated to Related_Nod
530 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
531 -- Create a new float and apply the constraint to obtain subtype of it
533 function Has_Range_Constraint (N : Node_Id) return Boolean;
534 -- Given an N_Subtype_Indication node N, return True if a range constraint
535 -- is present, either directly, or as part of a digits or delta constraint.
536 -- In addition, a digits constraint in the decimal case returns True, since
537 -- it establishes a default range if no explicit range is present.
539 function Inherit_Components
541 Parent_Base : Entity_Id;
542 Derived_Base : Entity_Id;
544 Inherit_Discr : Boolean;
545 Discs : Elist_Id) return Elist_Id;
546 -- Called from Build_Derived_Record_Type to inherit the components of
547 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
548 -- For more information on derived types and component inheritance please
549 -- consult the comment above the body of Build_Derived_Record_Type.
551 -- N is the original derived type declaration
553 -- Is_Tagged is set if we are dealing with tagged types
555 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from
556 -- Parent_Base, otherwise no discriminants are inherited.
558 -- Discs gives the list of constraints that apply to Parent_Base in the
559 -- derived type declaration. If Discs is set to No_Elist, then we have
560 -- the following situation:
562 -- type Parent (D1..Dn : ..) is [tagged] record ...;
563 -- type Derived is new Parent [with ...];
565 -- which gets treated as
567 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
569 -- For untagged types the returned value is an association list. The list
570 -- starts from the association (Parent_Base => Derived_Base), and then it
571 -- contains a sequence of the associations of the form
573 -- (Old_Component => New_Component),
575 -- where Old_Component is the Entity_Id of a component in Parent_Base and
576 -- New_Component is the Entity_Id of the corresponding component in
577 -- Derived_Base. For untagged records, this association list is needed when
578 -- copying the record declaration for the derived base. In the tagged case
579 -- the value returned is irrelevant.
581 function Is_Valid_Constraint_Kind
583 Constraint_Kind : Node_Kind) return Boolean;
584 -- Returns True if it is legal to apply the given kind of constraint to the
585 -- given kind of type (index constraint to an array type, for example).
587 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
588 -- Create new modular type. Verify that modulus is in bounds
590 procedure New_Concatenation_Op (Typ : Entity_Id);
591 -- Create an abbreviated declaration for an operator in order to
592 -- materialize concatenation on array types.
594 procedure Ordinary_Fixed_Point_Type_Declaration
597 -- Create a new ordinary fixed point type, and apply the constraint to
598 -- obtain subtype of it.
600 procedure Prepare_Private_Subtype_Completion
602 Related_Nod : Node_Id);
603 -- Id is a subtype of some private type. Creates the full declaration
604 -- associated with Id whenever possible, i.e. when the full declaration
605 -- of the base type is already known. Records each subtype into
606 -- Private_Dependents of the base type.
608 procedure Process_Incomplete_Dependents
612 -- Process all entities that depend on an incomplete type. There include
613 -- subtypes, subprogram types that mention the incomplete type in their
614 -- profiles, and subprogram with access parameters that designate the
617 -- Inc_T is the defining identifier of an incomplete type declaration, its
618 -- Ekind is E_Incomplete_Type.
620 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
622 -- Full_T is N's defining identifier.
624 -- Subtypes of incomplete types with discriminants are completed when the
625 -- parent type is. This is simpler than private subtypes, because they can
626 -- only appear in the same scope, and there is no need to exchange views.
627 -- Similarly, access_to_subprogram types may have a parameter or a return
628 -- type that is an incomplete type, and that must be replaced with the
631 -- If the full type is tagged, subprogram with access parameters that
632 -- designated the incomplete may be primitive operations of the full type,
633 -- and have to be processed accordingly.
635 procedure Process_Real_Range_Specification (Def : Node_Id);
636 -- Given the type definition for a real type, this procedure processes and
637 -- checks the real range specification of this type definition if one is
638 -- present. If errors are found, error messages are posted, and the
639 -- Real_Range_Specification of Def is reset to Empty.
641 procedure Record_Type_Declaration
645 -- Process a record type declaration (for both untagged and tagged
646 -- records). Parameters T and N are exactly like in procedure
647 -- Derived_Type_Declaration, except that no flag Is_Completion is needed
648 -- for this routine. If this is the completion of an incomplete type
649 -- declaration, Prev is the entity of the incomplete declaration, used for
650 -- cross-referencing. Otherwise Prev = T.
652 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
653 -- This routine is used to process the actual record type definition (both
654 -- for untagged and tagged records). Def is a record type definition node.
655 -- This procedure analyzes the components in this record type definition.
656 -- Prev_T is the entity for the enclosing record type. It is provided so
657 -- that its Has_Task flag can be set if any of the component have Has_Task
658 -- set. If the declaration is the completion of an incomplete type
659 -- declaration, Prev_T is the original incomplete type, whose full view is
662 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
663 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we
664 -- build a copy of the declaration tree of the parent, and we create
665 -- independently the list of components for the derived type. Semantic
666 -- information uses the component entities, but record representation
667 -- clauses are validated on the declaration tree. This procedure replaces
668 -- discriminants and components in the declaration with those that have
669 -- been created by Inherit_Components.
671 procedure Set_Fixed_Range
676 -- Build a range node with the given bounds and set it as the Scalar_Range
677 -- of the given fixed-point type entity. Loc is the source location used
678 -- for the constructed range. See body for further details.
680 procedure Set_Scalar_Range_For_Subtype
684 -- This routine is used to set the scalar range field for a subtype given
685 -- Def_Id, the entity for the subtype, and R, the range expression for the
686 -- scalar range. Subt provides the parent subtype to be used to analyze,
687 -- resolve, and check the given range.
689 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
690 -- Create a new signed integer entity, and apply the constraint to obtain
691 -- the required first named subtype of this type.
693 procedure Set_Stored_Constraint_From_Discriminant_Constraint
695 -- E is some record type. This routine computes E's Stored_Constraint
696 -- from its Discriminant_Constraint.
698 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id);
699 -- Check that an entity in a list of progenitors is an interface,
700 -- emit error otherwise.
702 -----------------------
703 -- Access_Definition --
704 -----------------------
706 function Access_Definition
707 (Related_Nod : Node_Id;
708 N : Node_Id) return Entity_Id
710 Anon_Type : Entity_Id;
711 Anon_Scope : Entity_Id;
712 Desig_Type : Entity_Id;
713 Enclosing_Prot_Type : Entity_Id := Empty;
716 Check_SPARK_Restriction ("access type is not allowed", N);
718 if Is_Entry (Current_Scope)
719 and then Is_Task_Type (Etype (Scope (Current_Scope)))
721 Error_Msg_N ("task entries cannot have access parameters", N);
725 -- Ada 2005: for an object declaration the corresponding anonymous
726 -- type is declared in the current scope.
728 -- If the access definition is the return type of another access to
729 -- function, scope is the current one, because it is the one of the
730 -- current type declaration, except for the pathological case below.
732 if Nkind_In (Related_Nod, N_Object_Declaration,
733 N_Access_Function_Definition)
735 Anon_Scope := Current_Scope;
737 -- A pathological case: function returning access functions that
738 -- return access functions, etc. Each anonymous access type created
739 -- is in the enclosing scope of the outermost function.
746 while Nkind_In (Par, N_Access_Function_Definition,
752 if Nkind (Par) = N_Function_Specification then
753 Anon_Scope := Scope (Defining_Entity (Par));
757 -- For the anonymous function result case, retrieve the scope of the
758 -- function specification's associated entity rather than using the
759 -- current scope. The current scope will be the function itself if the
760 -- formal part is currently being analyzed, but will be the parent scope
761 -- in the case of a parameterless function, and we always want to use
762 -- the function's parent scope. Finally, if the function is a child
763 -- unit, we must traverse the tree to retrieve the proper entity.
765 elsif Nkind (Related_Nod) = N_Function_Specification
766 and then Nkind (Parent (N)) /= N_Parameter_Specification
768 -- If the current scope is a protected type, the anonymous access
769 -- is associated with one of the protected operations, and must
770 -- be available in the scope that encloses the protected declaration.
771 -- Otherwise the type is in the scope enclosing the subprogram.
773 -- If the function has formals, The return type of a subprogram
774 -- declaration is analyzed in the scope of the subprogram (see
775 -- Process_Formals) and thus the protected type, if present, is
776 -- the scope of the current function scope.
778 if Ekind (Current_Scope) = E_Protected_Type then
779 Enclosing_Prot_Type := Current_Scope;
781 elsif Ekind (Current_Scope) = E_Function
782 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
784 Enclosing_Prot_Type := Scope (Current_Scope);
787 if Present (Enclosing_Prot_Type) then
788 Anon_Scope := Scope (Enclosing_Prot_Type);
791 Anon_Scope := Scope (Defining_Entity (Related_Nod));
794 -- For an access type definition, if the current scope is a child
795 -- unit it is the scope of the type.
797 elsif Is_Compilation_Unit (Current_Scope) then
798 Anon_Scope := Current_Scope;
800 -- For access formals, access components, and access discriminants, the
801 -- scope is that of the enclosing declaration,
804 Anon_Scope := Scope (Current_Scope);
809 (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope);
812 and then Ada_Version >= Ada_2005
814 Error_Msg_N ("ALL is not permitted for anonymous access types", N);
817 -- Ada 2005 (AI-254): In case of anonymous access to subprograms call
818 -- the corresponding semantic routine
820 if Present (Access_To_Subprogram_Definition (N)) then
822 -- Compiler runtime units are compiled in Ada 2005 mode when building
823 -- the runtime library but must also be compilable in Ada 95 mode
824 -- (when bootstrapping the compiler).
826 Check_Compiler_Unit (N);
828 Access_Subprogram_Declaration
829 (T_Name => Anon_Type,
830 T_Def => Access_To_Subprogram_Definition (N));
832 if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
834 (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
837 (Anon_Type, E_Anonymous_Access_Subprogram_Type);
840 Set_Can_Use_Internal_Rep
841 (Anon_Type, not Always_Compatible_Rep_On_Target);
843 -- If the anonymous access is associated with a protected operation,
844 -- create a reference to it after the enclosing protected definition
845 -- because the itype will be used in the subsequent bodies.
847 if Ekind (Current_Scope) = E_Protected_Type then
848 Build_Itype_Reference (Anon_Type, Parent (Current_Scope));
854 Find_Type (Subtype_Mark (N));
855 Desig_Type := Entity (Subtype_Mark (N));
857 Set_Directly_Designated_Type (Anon_Type, Desig_Type);
858 Set_Etype (Anon_Type, Anon_Type);
860 -- Make sure the anonymous access type has size and alignment fields
861 -- set, as required by gigi. This is necessary in the case of the
862 -- Task_Body_Procedure.
864 if not Has_Private_Component (Desig_Type) then
865 Layout_Type (Anon_Type);
868 -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
869 -- from Ada 95 semantics. In Ada 2005, anonymous access must specify if
870 -- the null value is allowed. In Ada 95 the null value is never allowed.
872 if Ada_Version >= Ada_2005 then
873 Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
875 Set_Can_Never_Be_Null (Anon_Type, True);
878 -- The anonymous access type is as public as the discriminated type or
879 -- subprogram that defines it. It is imported (for back-end purposes)
880 -- if the designated type is.
882 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
884 -- Ada 2005 (AI-231): Propagate the access-constant attribute
886 Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
888 -- The context is either a subprogram declaration, object declaration,
889 -- or an access discriminant, in a private or a full type declaration.
890 -- In the case of a subprogram, if the designated type is incomplete,
891 -- the operation will be a primitive operation of the full type, to be
892 -- updated subsequently. If the type is imported through a limited_with
893 -- clause, the subprogram is not a primitive operation of the type
894 -- (which is declared elsewhere in some other scope).
896 if Ekind (Desig_Type) = E_Incomplete_Type
897 and then not From_With_Type (Desig_Type)
898 and then Is_Overloadable (Current_Scope)
900 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
901 Set_Has_Delayed_Freeze (Current_Scope);
904 -- Ada 2005: if the designated type is an interface that may contain
905 -- tasks, create a Master entity for the declaration. This must be done
906 -- before expansion of the full declaration, because the declaration may
907 -- include an expression that is an allocator, whose expansion needs the
908 -- proper Master for the created tasks.
910 if Nkind (Related_Nod) = N_Object_Declaration
911 and then Expander_Active
913 if Is_Interface (Desig_Type)
914 and then Is_Limited_Record (Desig_Type)
916 Build_Class_Wide_Master (Anon_Type);
918 -- Similarly, if the type is an anonymous access that designates
919 -- tasks, create a master entity for it in the current context.
921 elsif Has_Task (Desig_Type)
922 and then Comes_From_Source (Related_Nod)
924 Build_Master_Entity (Defining_Identifier (Related_Nod));
925 Build_Master_Renaming (Anon_Type);
929 -- For a private component of a protected type, it is imperative that
930 -- the back-end elaborate the type immediately after the protected
931 -- declaration, because this type will be used in the declarations
932 -- created for the component within each protected body, so we must
933 -- create an itype reference for it now.
935 if Nkind (Parent (Related_Nod)) = N_Protected_Definition then
936 Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod)));
938 -- Similarly, if the access definition is the return result of a
939 -- function, create an itype reference for it because it will be used
940 -- within the function body. For a regular function that is not a
941 -- compilation unit, insert reference after the declaration. For a
942 -- protected operation, insert it after the enclosing protected type
943 -- declaration. In either case, do not create a reference for a type
944 -- obtained through a limited_with clause, because this would introduce
945 -- semantic dependencies.
947 -- Similarly, do not create a reference if the designated type is a
948 -- generic formal, because no use of it will reach the backend.
950 elsif Nkind (Related_Nod) = N_Function_Specification
951 and then not From_With_Type (Desig_Type)
952 and then not Is_Generic_Type (Desig_Type)
954 if Present (Enclosing_Prot_Type) then
955 Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type));
957 elsif Is_List_Member (Parent (Related_Nod))
958 and then Nkind (Parent (N)) /= N_Parameter_Specification
960 Build_Itype_Reference (Anon_Type, Parent (Related_Nod));
963 -- Finally, create an itype reference for an object declaration of an
964 -- anonymous access type. This is strictly necessary only for deferred
965 -- constants, but in any case will avoid out-of-scope problems in the
968 elsif Nkind (Related_Nod) = N_Object_Declaration then
969 Build_Itype_Reference (Anon_Type, Related_Nod);
973 end Access_Definition;
975 -----------------------------------
976 -- Access_Subprogram_Declaration --
977 -----------------------------------
979 procedure Access_Subprogram_Declaration
984 procedure Check_For_Premature_Usage (Def : Node_Id);
985 -- Check that type T_Name is not used, directly or recursively, as a
986 -- parameter or a return type in Def. Def is either a subtype, an
987 -- access_definition, or an access_to_subprogram_definition.
989 -------------------------------
990 -- Check_For_Premature_Usage --
991 -------------------------------
993 procedure Check_For_Premature_Usage (Def : Node_Id) is
997 -- Check for a subtype mark
999 if Nkind (Def) in N_Has_Etype then
1000 if Etype (Def) = T_Name then
1002 ("type& cannot be used before end of its declaration", Def);
1005 -- If this is not a subtype, then this is an access_definition
1007 elsif Nkind (Def) = N_Access_Definition then
1008 if Present (Access_To_Subprogram_Definition (Def)) then
1009 Check_For_Premature_Usage
1010 (Access_To_Subprogram_Definition (Def));
1012 Check_For_Premature_Usage (Subtype_Mark (Def));
1015 -- The only cases left are N_Access_Function_Definition and
1016 -- N_Access_Procedure_Definition.
1019 if Present (Parameter_Specifications (Def)) then
1020 Param := First (Parameter_Specifications (Def));
1021 while Present (Param) loop
1022 Check_For_Premature_Usage (Parameter_Type (Param));
1023 Param := Next (Param);
1027 if Nkind (Def) = N_Access_Function_Definition then
1028 Check_For_Premature_Usage (Result_Definition (Def));
1031 end Check_For_Premature_Usage;
1035 Formals : constant List_Id := Parameter_Specifications (T_Def);
1038 Desig_Type : constant Entity_Id :=
1039 Create_Itype (E_Subprogram_Type, Parent (T_Def));
1041 -- Start of processing for Access_Subprogram_Declaration
1044 Check_SPARK_Restriction ("access type is not allowed", T_Def);
1046 -- Associate the Itype node with the inner full-type declaration or
1047 -- subprogram spec or entry body. This is required to handle nested
1048 -- anonymous declarations. For example:
1051 -- (X : access procedure
1052 -- (Y : access procedure
1055 D_Ityp := Associated_Node_For_Itype (Desig_Type);
1056 while not (Nkind_In (D_Ityp, N_Full_Type_Declaration,
1057 N_Private_Type_Declaration,
1058 N_Private_Extension_Declaration,
1059 N_Procedure_Specification,
1060 N_Function_Specification,
1064 Nkind_In (D_Ityp, N_Object_Declaration,
1065 N_Object_Renaming_Declaration,
1066 N_Formal_Object_Declaration,
1067 N_Formal_Type_Declaration,
1068 N_Task_Type_Declaration,
1069 N_Protected_Type_Declaration))
1071 D_Ityp := Parent (D_Ityp);
1072 pragma Assert (D_Ityp /= Empty);
1075 Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
1077 if Nkind_In (D_Ityp, N_Procedure_Specification,
1078 N_Function_Specification)
1080 Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
1082 elsif Nkind_In (D_Ityp, N_Full_Type_Declaration,
1083 N_Object_Declaration,
1084 N_Object_Renaming_Declaration,
1085 N_Formal_Type_Declaration)
1087 Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
1090 if Nkind (T_Def) = N_Access_Function_Definition then
1091 if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
1093 Acc : constant Node_Id := Result_Definition (T_Def);
1096 if Present (Access_To_Subprogram_Definition (Acc))
1098 Protected_Present (Access_To_Subprogram_Definition (Acc))
1102 Replace_Anonymous_Access_To_Protected_Subprogram
1108 Access_Definition (T_Def, Result_Definition (T_Def)));
1113 Analyze (Result_Definition (T_Def));
1116 Typ : constant Entity_Id := Entity (Result_Definition (T_Def));
1119 -- If a null exclusion is imposed on the result type, then
1120 -- create a null-excluding itype (an access subtype) and use
1121 -- it as the function's Etype.
1123 if Is_Access_Type (Typ)
1124 and then Null_Exclusion_In_Return_Present (T_Def)
1126 Set_Etype (Desig_Type,
1127 Create_Null_Excluding_Itype
1129 Related_Nod => T_Def,
1130 Scope_Id => Current_Scope));
1133 if From_With_Type (Typ) then
1135 -- AI05-151: Incomplete types are allowed in all basic
1136 -- declarations, including access to subprograms.
1138 if Ada_Version >= Ada_2012 then
1143 ("illegal use of incomplete type&",
1144 Result_Definition (T_Def), Typ);
1147 elsif Ekind (Current_Scope) = E_Package
1148 and then In_Private_Part (Current_Scope)
1150 if Ekind (Typ) = E_Incomplete_Type then
1151 Append_Elmt (Desig_Type, Private_Dependents (Typ));
1153 elsif Is_Class_Wide_Type (Typ)
1154 and then Ekind (Etype (Typ)) = E_Incomplete_Type
1157 (Desig_Type, Private_Dependents (Etype (Typ)));
1161 Set_Etype (Desig_Type, Typ);
1166 if not (Is_Type (Etype (Desig_Type))) then
1168 ("expect type in function specification",
1169 Result_Definition (T_Def));
1173 Set_Etype (Desig_Type, Standard_Void_Type);
1176 if Present (Formals) then
1177 Push_Scope (Desig_Type);
1179 -- A bit of a kludge here. These kludges will be removed when Itypes
1180 -- have proper parent pointers to their declarations???
1182 -- Kludge 1) Link defining_identifier of formals. Required by
1183 -- First_Formal to provide its functionality.
1189 F := First (Formals);
1191 -- In ASIS mode, the access_to_subprogram may be analyzed twice,
1192 -- when it is part of an unconstrained type and subtype expansion
1193 -- is disabled. To avoid back-end problems with shared profiles,
1194 -- use previous subprogram type as the designated type.
1197 and then Present (Scope (Defining_Identifier (F)))
1199 Set_Etype (T_Name, T_Name);
1200 Init_Size_Align (T_Name);
1201 Set_Directly_Designated_Type (T_Name,
1202 Scope (Defining_Identifier (F)));
1206 while Present (F) loop
1207 if No (Parent (Defining_Identifier (F))) then
1208 Set_Parent (Defining_Identifier (F), F);
1215 Process_Formals (Formals, Parent (T_Def));
1217 -- Kludge 2) End_Scope requires that the parent pointer be set to
1218 -- something reasonable, but Itypes don't have parent pointers. So
1219 -- we set it and then unset it ???
1221 Set_Parent (Desig_Type, T_Name);
1223 Set_Parent (Desig_Type, Empty);
1226 -- Check for premature usage of the type being defined
1228 Check_For_Premature_Usage (T_Def);
1230 -- The return type and/or any parameter type may be incomplete. Mark
1231 -- the subprogram_type as depending on the incomplete type, so that
1232 -- it can be updated when the full type declaration is seen. This
1233 -- only applies to incomplete types declared in some enclosing scope,
1234 -- not to limited views from other packages.
1236 if Present (Formals) then
1237 Formal := First_Formal (Desig_Type);
1238 while Present (Formal) loop
1239 if Ekind (Formal) /= E_In_Parameter
1240 and then Nkind (T_Def) = N_Access_Function_Definition
1242 Error_Msg_N ("functions can only have IN parameters", Formal);
1245 if Ekind (Etype (Formal)) = E_Incomplete_Type
1246 and then In_Open_Scopes (Scope (Etype (Formal)))
1248 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
1249 Set_Has_Delayed_Freeze (Desig_Type);
1252 Next_Formal (Formal);
1256 -- If the return type is incomplete, this is legal as long as the
1257 -- type is declared in the current scope and will be completed in
1258 -- it (rather than being part of limited view).
1260 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
1261 and then not Has_Delayed_Freeze (Desig_Type)
1262 and then In_Open_Scopes (Scope (Etype (Desig_Type)))
1264 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
1265 Set_Has_Delayed_Freeze (Desig_Type);
1268 Check_Delayed_Subprogram (Desig_Type);
1270 if Protected_Present (T_Def) then
1271 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
1272 Set_Convention (Desig_Type, Convention_Protected);
1274 Set_Ekind (T_Name, E_Access_Subprogram_Type);
1277 Set_Can_Use_Internal_Rep (T_Name, not Always_Compatible_Rep_On_Target);
1279 Set_Etype (T_Name, T_Name);
1280 Init_Size_Align (T_Name);
1281 Set_Directly_Designated_Type (T_Name, Desig_Type);
1283 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
1285 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
1287 Check_Restriction (No_Access_Subprograms, T_Def);
1288 end Access_Subprogram_Declaration;
1290 ----------------------------
1291 -- Access_Type_Declaration --
1292 ----------------------------
1294 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
1295 P : constant Node_Id := Parent (Def);
1296 S : constant Node_Id := Subtype_Indication (Def);
1298 Full_Desig : Entity_Id;
1301 Check_SPARK_Restriction ("access type is not allowed", Def);
1303 -- Check for permissible use of incomplete type
1305 if Nkind (S) /= N_Subtype_Indication then
1308 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
1309 Set_Directly_Designated_Type (T, Entity (S));
1311 Set_Directly_Designated_Type (T,
1312 Process_Subtype (S, P, T, 'P'));
1316 Set_Directly_Designated_Type (T,
1317 Process_Subtype (S, P, T, 'P'));
1320 if All_Present (Def) or Constant_Present (Def) then
1321 Set_Ekind (T, E_General_Access_Type);
1323 Set_Ekind (T, E_Access_Type);
1326 Full_Desig := Designated_Type (T);
1328 if Base_Type (Full_Desig) = T then
1329 Error_Msg_N ("access type cannot designate itself", S);
1331 -- In Ada 2005, the type may have a limited view through some unit
1332 -- in its own context, allowing the following circularity that cannot
1333 -- be detected earlier
1335 elsif Is_Class_Wide_Type (Full_Desig)
1336 and then Etype (Full_Desig) = T
1339 ("access type cannot designate its own classwide type", S);
1341 -- Clean up indication of tagged status to prevent cascaded errors
1343 Set_Is_Tagged_Type (T, False);
1348 -- If the type has appeared already in a with_type clause, it is
1349 -- frozen and the pointer size is already set. Else, initialize.
1351 if not From_With_Type (T) then
1352 Init_Size_Align (T);
1355 -- Note that Has_Task is always false, since the access type itself
1356 -- is not a task type. See Einfo for more description on this point.
1357 -- Exactly the same consideration applies to Has_Controlled_Component.
1359 Set_Has_Task (T, False);
1360 Set_Has_Controlled_Component (T, False);
1362 -- Initialize field Finalization_Master explicitly to Empty, to avoid
1363 -- problems where an incomplete view of this entity has been previously
1364 -- established by a limited with and an overlaid version of this field
1365 -- (Stored_Constraint) was initialized for the incomplete view.
1367 -- This reset is performed in most cases except where the access type
1368 -- has been created for the purposes of allocating or deallocating a
1369 -- build-in-place object. Such access types have explicitly set pools
1370 -- and finalization masters.
1372 if No (Associated_Storage_Pool (T)) then
1373 Set_Finalization_Master (T, Empty);
1376 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
1379 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
1380 Set_Is_Access_Constant (T, Constant_Present (Def));
1381 end Access_Type_Declaration;
1383 ----------------------------------
1384 -- Add_Interface_Tag_Components --
1385 ----------------------------------
1387 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is
1388 Loc : constant Source_Ptr := Sloc (N);
1392 procedure Add_Tag (Iface : Entity_Id);
1393 -- Add tag for one of the progenitor interfaces
1399 procedure Add_Tag (Iface : Entity_Id) is
1406 pragma Assert (Is_Tagged_Type (Iface)
1407 and then Is_Interface (Iface));
1409 -- This is a reasonable place to propagate predicates
1411 if Has_Predicates (Iface) then
1412 Set_Has_Predicates (Typ);
1416 Make_Component_Definition (Loc,
1417 Aliased_Present => True,
1418 Subtype_Indication =>
1419 New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
1421 Tag := Make_Temporary (Loc, 'V');
1424 Make_Component_Declaration (Loc,
1425 Defining_Identifier => Tag,
1426 Component_Definition => Def);
1428 Analyze_Component_Declaration (Decl);
1430 Set_Analyzed (Decl);
1431 Set_Ekind (Tag, E_Component);
1433 Set_Is_Aliased (Tag);
1434 Set_Related_Type (Tag, Iface);
1435 Init_Component_Location (Tag);
1437 pragma Assert (Is_Frozen (Iface));
1439 Set_DT_Entry_Count (Tag,
1440 DT_Entry_Count (First_Entity (Iface)));
1442 if No (Last_Tag) then
1445 Insert_After (Last_Tag, Decl);
1450 -- If the ancestor has discriminants we need to give special support
1451 -- to store the offset_to_top value of the secondary dispatch tables.
1452 -- For this purpose we add a supplementary component just after the
1453 -- field that contains the tag associated with each secondary DT.
1455 if Typ /= Etype (Typ)
1456 and then Has_Discriminants (Etype (Typ))
1459 Make_Component_Definition (Loc,
1460 Subtype_Indication =>
1461 New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
1463 Offset := Make_Temporary (Loc, 'V');
1466 Make_Component_Declaration (Loc,
1467 Defining_Identifier => Offset,
1468 Component_Definition => Def);
1470 Analyze_Component_Declaration (Decl);
1472 Set_Analyzed (Decl);
1473 Set_Ekind (Offset, E_Component);
1474 Set_Is_Aliased (Offset);
1475 Set_Related_Type (Offset, Iface);
1476 Init_Component_Location (Offset);
1477 Insert_After (Last_Tag, Decl);
1488 -- Start of processing for Add_Interface_Tag_Components
1491 if not RTE_Available (RE_Interface_Tag) then
1493 ("(Ada 2005) interface types not supported by this run-time!",
1498 if Ekind (Typ) /= E_Record_Type
1499 or else (Is_Concurrent_Record_Type (Typ)
1500 and then Is_Empty_List (Abstract_Interface_List (Typ)))
1501 or else (not Is_Concurrent_Record_Type (Typ)
1502 and then No (Interfaces (Typ))
1503 and then Is_Empty_Elmt_List (Interfaces (Typ)))
1508 -- Find the current last tag
1510 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1511 Ext := Record_Extension_Part (Type_Definition (N));
1513 pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
1514 Ext := Type_Definition (N);
1519 if not (Present (Component_List (Ext))) then
1520 Set_Null_Present (Ext, False);
1522 Set_Component_List (Ext,
1523 Make_Component_List (Loc,
1524 Component_Items => L,
1525 Null_Present => False));
1527 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1528 L := Component_Items
1530 (Record_Extension_Part
1531 (Type_Definition (N))));
1533 L := Component_Items
1535 (Type_Definition (N)));
1538 -- Find the last tag component
1541 while Present (Comp) loop
1542 if Nkind (Comp) = N_Component_Declaration
1543 and then Is_Tag (Defining_Identifier (Comp))
1552 -- At this point L references the list of components and Last_Tag
1553 -- references the current last tag (if any). Now we add the tag
1554 -- corresponding with all the interfaces that are not implemented
1557 if Present (Interfaces (Typ)) then
1558 Elmt := First_Elmt (Interfaces (Typ));
1559 while Present (Elmt) loop
1560 Add_Tag (Node (Elmt));
1564 end Add_Interface_Tag_Components;
1566 -------------------------------------
1567 -- Add_Internal_Interface_Entities --
1568 -------------------------------------
1570 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is
1573 Iface_Elmt : Elmt_Id;
1574 Iface_Prim : Entity_Id;
1575 Ifaces_List : Elist_Id;
1576 New_Subp : Entity_Id := Empty;
1578 Restore_Scope : Boolean := False;
1581 pragma Assert (Ada_Version >= Ada_2005
1582 and then Is_Record_Type (Tagged_Type)
1583 and then Is_Tagged_Type (Tagged_Type)
1584 and then Has_Interfaces (Tagged_Type)
1585 and then not Is_Interface (Tagged_Type));
1587 -- Ensure that the internal entities are added to the scope of the type
1589 if Scope (Tagged_Type) /= Current_Scope then
1590 Push_Scope (Scope (Tagged_Type));
1591 Restore_Scope := True;
1594 Collect_Interfaces (Tagged_Type, Ifaces_List);
1596 Iface_Elmt := First_Elmt (Ifaces_List);
1597 while Present (Iface_Elmt) loop
1598 Iface := Node (Iface_Elmt);
1600 -- Originally we excluded here from this processing interfaces that
1601 -- are parents of Tagged_Type because their primitives are located
1602 -- in the primary dispatch table (and hence no auxiliary internal
1603 -- entities are required to handle secondary dispatch tables in such
1604 -- case). However, these auxiliary entities are also required to
1605 -- handle derivations of interfaces in formals of generics (see
1606 -- Derive_Subprograms).
1608 Elmt := First_Elmt (Primitive_Operations (Iface));
1609 while Present (Elmt) loop
1610 Iface_Prim := Node (Elmt);
1612 if not Is_Predefined_Dispatching_Operation (Iface_Prim) then
1614 Find_Primitive_Covering_Interface
1615 (Tagged_Type => Tagged_Type,
1616 Iface_Prim => Iface_Prim);
1618 if No (Prim) and then Serious_Errors_Detected > 0 then
1622 pragma Assert (Present (Prim));
1624 -- Ada 2012 (AI05-0197): If the name of the covering primitive
1625 -- differs from the name of the interface primitive then it is
1626 -- a private primitive inherited from a parent type. In such
1627 -- case, given that Tagged_Type covers the interface, the
1628 -- inherited private primitive becomes visible. For such
1629 -- purpose we add a new entity that renames the inherited
1630 -- private primitive.
1632 if Chars (Prim) /= Chars (Iface_Prim) then
1633 pragma Assert (Has_Suffix (Prim, 'P'));
1635 (New_Subp => New_Subp,
1636 Parent_Subp => Iface_Prim,
1637 Derived_Type => Tagged_Type,
1638 Parent_Type => Iface);
1639 Set_Alias (New_Subp, Prim);
1640 Set_Is_Abstract_Subprogram
1641 (New_Subp, Is_Abstract_Subprogram (Prim));
1645 (New_Subp => New_Subp,
1646 Parent_Subp => Iface_Prim,
1647 Derived_Type => Tagged_Type,
1648 Parent_Type => Iface);
1650 -- Ada 2005 (AI-251): Decorate internal entity Iface_Subp
1651 -- associated with interface types. These entities are
1652 -- only registered in the list of primitives of its
1653 -- corresponding tagged type because they are only used
1654 -- to fill the contents of the secondary dispatch tables.
1655 -- Therefore they are removed from the homonym chains.
1657 Set_Is_Hidden (New_Subp);
1658 Set_Is_Internal (New_Subp);
1659 Set_Alias (New_Subp, Prim);
1660 Set_Is_Abstract_Subprogram
1661 (New_Subp, Is_Abstract_Subprogram (Prim));
1662 Set_Interface_Alias (New_Subp, Iface_Prim);
1664 -- Internal entities associated with interface types are
1665 -- only registered in the list of primitives of the tagged
1666 -- type. They are only used to fill the contents of the
1667 -- secondary dispatch tables. Therefore they are not needed
1668 -- in the homonym chains.
1670 Remove_Homonym (New_Subp);
1672 -- Hidden entities associated with interfaces must have set
1673 -- the Has_Delay_Freeze attribute to ensure that, in case of
1674 -- locally defined tagged types (or compiling with static
1675 -- dispatch tables generation disabled) the corresponding
1676 -- entry of the secondary dispatch table is filled when
1677 -- such an entity is frozen.
1679 Set_Has_Delayed_Freeze (New_Subp);
1686 Next_Elmt (Iface_Elmt);
1689 if Restore_Scope then
1692 end Add_Internal_Interface_Entities;
1694 -----------------------------------
1695 -- Analyze_Component_Declaration --
1696 -----------------------------------
1698 procedure Analyze_Component_Declaration (N : Node_Id) is
1699 Id : constant Entity_Id := Defining_Identifier (N);
1700 E : constant Node_Id := Expression (N);
1701 Typ : constant Node_Id :=
1702 Subtype_Indication (Component_Definition (N));
1706 function Contains_POC (Constr : Node_Id) return Boolean;
1707 -- Determines whether a constraint uses the discriminant of a record
1708 -- type thus becoming a per-object constraint (POC).
1710 function Is_Known_Limited (Typ : Entity_Id) return Boolean;
1711 -- Typ is the type of the current component, check whether this type is
1712 -- a limited type. Used to validate declaration against that of
1713 -- enclosing record.
1719 function Contains_POC (Constr : Node_Id) return Boolean is
1721 -- Prevent cascaded errors
1723 if Error_Posted (Constr) then
1727 case Nkind (Constr) is
1728 when N_Attribute_Reference =>
1730 Attribute_Name (Constr) = Name_Access
1731 and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
1733 when N_Discriminant_Association =>
1734 return Denotes_Discriminant (Expression (Constr));
1736 when N_Identifier =>
1737 return Denotes_Discriminant (Constr);
1739 when N_Index_Or_Discriminant_Constraint =>
1744 IDC := First (Constraints (Constr));
1745 while Present (IDC) loop
1747 -- One per-object constraint is sufficient
1749 if Contains_POC (IDC) then
1760 return Denotes_Discriminant (Low_Bound (Constr))
1762 Denotes_Discriminant (High_Bound (Constr));
1764 when N_Range_Constraint =>
1765 return Denotes_Discriminant (Range_Expression (Constr));
1773 ----------------------
1774 -- Is_Known_Limited --
1775 ----------------------
1777 function Is_Known_Limited (Typ : Entity_Id) return Boolean is
1778 P : constant Entity_Id := Etype (Typ);
1779 R : constant Entity_Id := Root_Type (Typ);
1782 if Is_Limited_Record (Typ) then
1785 -- If the root type is limited (and not a limited interface)
1786 -- so is the current type
1788 elsif Is_Limited_Record (R)
1790 (not Is_Interface (R)
1791 or else not Is_Limited_Interface (R))
1795 -- Else the type may have a limited interface progenitor, but a
1796 -- limited record parent.
1799 and then Is_Limited_Record (P)
1806 end Is_Known_Limited;
1808 -- Start of processing for Analyze_Component_Declaration
1811 Generate_Definition (Id);
1814 if Present (Typ) then
1815 T := Find_Type_Of_Object
1816 (Subtype_Indication (Component_Definition (N)), N);
1818 if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then
1819 Check_SPARK_Restriction ("subtype mark required", Typ);
1822 -- Ada 2005 (AI-230): Access Definition case
1825 pragma Assert (Present
1826 (Access_Definition (Component_Definition (N))));
1828 T := Access_Definition
1830 N => Access_Definition (Component_Definition (N)));
1831 Set_Is_Local_Anonymous_Access (T);
1833 -- Ada 2005 (AI-254)
1835 if Present (Access_To_Subprogram_Definition
1836 (Access_Definition (Component_Definition (N))))
1837 and then Protected_Present (Access_To_Subprogram_Definition
1839 (Component_Definition (N))))
1841 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
1845 -- If the subtype is a constrained subtype of the enclosing record,
1846 -- (which must have a partial view) the back-end does not properly
1847 -- handle the recursion. Rewrite the component declaration with an
1848 -- explicit subtype indication, which is acceptable to Gigi. We can copy
1849 -- the tree directly because side effects have already been removed from
1850 -- discriminant constraints.
1852 if Ekind (T) = E_Access_Subtype
1853 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
1854 and then Comes_From_Source (T)
1855 and then Nkind (Parent (T)) = N_Subtype_Declaration
1856 and then Etype (Directly_Designated_Type (T)) = Current_Scope
1859 (Subtype_Indication (Component_Definition (N)),
1860 New_Copy_Tree (Subtype_Indication (Parent (T))));
1861 T := Find_Type_Of_Object
1862 (Subtype_Indication (Component_Definition (N)), N);
1865 -- If the component declaration includes a default expression, then we
1866 -- check that the component is not of a limited type (RM 3.7(5)),
1867 -- and do the special preanalysis of the expression (see section on
1868 -- "Handling of Default and Per-Object Expressions" in the spec of
1872 Check_SPARK_Restriction ("default expression is not allowed", E);
1873 Preanalyze_Spec_Expression (E, T);
1874 Check_Initialization (T, E);
1876 if Ada_Version >= Ada_2005
1877 and then Ekind (T) = E_Anonymous_Access_Type
1878 and then Etype (E) /= Any_Type
1880 -- Check RM 3.9.2(9): "if the expected type for an expression is
1881 -- an anonymous access-to-specific tagged type, then the object
1882 -- designated by the expression shall not be dynamically tagged
1883 -- unless it is a controlling operand in a call on a dispatching
1886 if Is_Tagged_Type (Directly_Designated_Type (T))
1888 Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
1890 Ekind (Directly_Designated_Type (Etype (E))) =
1894 ("access to specific tagged type required (RM 3.9.2(9))", E);
1897 -- (Ada 2005: AI-230): Accessibility check for anonymous
1900 if Type_Access_Level (Etype (E)) >
1901 Deepest_Type_Access_Level (T)
1904 ("expression has deeper access level than component " &
1905 "(RM 3.10.2 (12.2))", E);
1908 -- The initialization expression is a reference to an access
1909 -- discriminant. The type of the discriminant is always deeper
1910 -- than any access type.
1912 if Ekind (Etype (E)) = E_Anonymous_Access_Type
1913 and then Is_Entity_Name (E)
1914 and then Ekind (Entity (E)) = E_In_Parameter
1915 and then Present (Discriminal_Link (Entity (E)))
1918 ("discriminant has deeper accessibility level than target",
1924 -- The parent type may be a private view with unknown discriminants,
1925 -- and thus unconstrained. Regular components must be constrained.
1927 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
1928 if Is_Class_Wide_Type (T) then
1930 ("class-wide subtype with unknown discriminants" &
1931 " in component declaration",
1932 Subtype_Indication (Component_Definition (N)));
1935 ("unconstrained subtype in component declaration",
1936 Subtype_Indication (Component_Definition (N)));
1939 -- Components cannot be abstract, except for the special case of
1940 -- the _Parent field (case of extending an abstract tagged type)
1942 elsif Is_Abstract_Type (T) and then Chars (Id) /= Name_uParent then
1943 Error_Msg_N ("type of a component cannot be abstract", N);
1947 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
1949 -- The component declaration may have a per-object constraint, set
1950 -- the appropriate flag in the defining identifier of the subtype.
1952 if Present (Subtype_Indication (Component_Definition (N))) then
1954 Sindic : constant Node_Id :=
1955 Subtype_Indication (Component_Definition (N));
1957 if Nkind (Sindic) = N_Subtype_Indication
1958 and then Present (Constraint (Sindic))
1959 and then Contains_POC (Constraint (Sindic))
1961 Set_Has_Per_Object_Constraint (Id);
1966 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
1967 -- out some static checks.
1969 if Ada_Version >= Ada_2005
1970 and then Can_Never_Be_Null (T)
1972 Null_Exclusion_Static_Checks (N);
1975 -- If this component is private (or depends on a private type), flag the
1976 -- record type to indicate that some operations are not available.
1978 P := Private_Component (T);
1982 -- Check for circular definitions
1984 if P = Any_Type then
1985 Set_Etype (Id, Any_Type);
1987 -- There is a gap in the visibility of operations only if the
1988 -- component type is not defined in the scope of the record type.
1990 elsif Scope (P) = Scope (Current_Scope) then
1993 elsif Is_Limited_Type (P) then
1994 Set_Is_Limited_Composite (Current_Scope);
1997 Set_Is_Private_Composite (Current_Scope);
2002 and then Is_Limited_Type (T)
2003 and then Chars (Id) /= Name_uParent
2004 and then Is_Tagged_Type (Current_Scope)
2006 if Is_Derived_Type (Current_Scope)
2007 and then not Is_Known_Limited (Current_Scope)
2010 ("extension of nonlimited type cannot have limited components",
2013 if Is_Interface (Root_Type (Current_Scope)) then
2015 ("\limitedness is not inherited from limited interface", N);
2016 Error_Msg_N ("\add LIMITED to type indication", N);
2019 Explain_Limited_Type (T, N);
2020 Set_Etype (Id, Any_Type);
2021 Set_Is_Limited_Composite (Current_Scope, False);
2023 elsif not Is_Derived_Type (Current_Scope)
2024 and then not Is_Limited_Record (Current_Scope)
2025 and then not Is_Concurrent_Type (Current_Scope)
2028 ("nonlimited tagged type cannot have limited components", N);
2029 Explain_Limited_Type (T, N);
2030 Set_Etype (Id, Any_Type);
2031 Set_Is_Limited_Composite (Current_Scope, False);
2035 Set_Original_Record_Component (Id, Id);
2037 if Has_Aspects (N) then
2038 Analyze_Aspect_Specifications (N, Id);
2041 Analyze_Dimension (N);
2042 end Analyze_Component_Declaration;
2044 --------------------------
2045 -- Analyze_Declarations --
2046 --------------------------
2048 procedure Analyze_Declarations (L : List_Id) is
2050 Freeze_From : Entity_Id := Empty;
2051 Next_Node : Node_Id;
2054 -- Adjust D not to include implicit label declarations, since these
2055 -- have strange Sloc values that result in elaboration check problems.
2056 -- (They have the sloc of the label as found in the source, and that
2057 -- is ahead of the current declarative part).
2063 procedure Adjust_D is
2065 while Present (Prev (D))
2066 and then Nkind (D) = N_Implicit_Label_Declaration
2072 -- Start of processing for Analyze_Declarations
2075 if Restriction_Check_Required (SPARK) then
2076 Check_Later_Vs_Basic_Declarations (L, During_Parsing => False);
2080 while Present (D) loop
2082 -- Package spec cannot contain a package declaration in SPARK
2084 if Nkind (D) = N_Package_Declaration
2085 and then Nkind (Parent (L)) = N_Package_Specification
2087 Check_SPARK_Restriction
2088 ("package specification cannot contain a package declaration",
2092 -- Complete analysis of declaration
2095 Next_Node := Next (D);
2097 if No (Freeze_From) then
2098 Freeze_From := First_Entity (Current_Scope);
2101 -- At the end of a declarative part, freeze remaining entities
2102 -- declared in it. The end of the visible declarations of package
2103 -- specification is not the end of a declarative part if private
2104 -- declarations are present. The end of a package declaration is a
2105 -- freezing point only if it a library package. A task definition or
2106 -- protected type definition is not a freeze point either. Finally,
2107 -- we do not freeze entities in generic scopes, because there is no
2108 -- code generated for them and freeze nodes will be generated for
2111 -- The end of a package instantiation is not a freeze point, but
2112 -- for now we make it one, because the generic body is inserted
2113 -- (currently) immediately after. Generic instantiations will not
2114 -- be a freeze point once delayed freezing of bodies is implemented.
2115 -- (This is needed in any case for early instantiations ???).
2117 if No (Next_Node) then
2118 if Nkind_In (Parent (L), N_Component_List,
2120 N_Protected_Definition)
2124 elsif Nkind (Parent (L)) /= N_Package_Specification then
2125 if Nkind (Parent (L)) = N_Package_Body then
2126 Freeze_From := First_Entity (Current_Scope);
2130 Freeze_All (Freeze_From, D);
2131 Freeze_From := Last_Entity (Current_Scope);
2133 elsif Scope (Current_Scope) /= Standard_Standard
2134 and then not Is_Child_Unit (Current_Scope)
2135 and then No (Generic_Parent (Parent (L)))
2139 elsif L /= Visible_Declarations (Parent (L))
2140 or else No (Private_Declarations (Parent (L)))
2141 or else Is_Empty_List (Private_Declarations (Parent (L)))
2144 Freeze_All (Freeze_From, D);
2145 Freeze_From := Last_Entity (Current_Scope);
2148 -- If next node is a body then freeze all types before the body.
2149 -- An exception occurs for some expander-generated bodies. If these
2150 -- are generated at places where in general language rules would not
2151 -- allow a freeze point, then we assume that the expander has
2152 -- explicitly checked that all required types are properly frozen,
2153 -- and we do not cause general freezing here. This special circuit
2154 -- is used when the encountered body is marked as having already
2157 -- In all other cases (bodies that come from source, and expander
2158 -- generated bodies that have not been analyzed yet), freeze all
2159 -- types now. Note that in the latter case, the expander must take
2160 -- care to attach the bodies at a proper place in the tree so as to
2161 -- not cause unwanted freezing at that point.
2163 elsif not Analyzed (Next_Node)
2164 and then (Nkind_In (Next_Node, N_Subprogram_Body,
2170 Nkind (Next_Node) in N_Body_Stub)
2173 Freeze_All (Freeze_From, D);
2174 Freeze_From := Last_Entity (Current_Scope);
2180 -- One more thing to do, we need to scan the declarations to check
2181 -- for any precondition/postcondition pragmas (Pre/Post aspects have
2182 -- by this stage been converted into corresponding pragmas). It is
2183 -- at this point that we analyze the expressions in such pragmas,
2184 -- to implement the delayed visibility requirement.
2194 while Present (Decl) loop
2195 if Nkind (Original_Node (Decl)) = N_Subprogram_Declaration then
2196 Spec := Specification (Original_Node (Decl));
2197 Sent := Defining_Unit_Name (Spec);
2199 Prag := Spec_PPC_List (Contract (Sent));
2200 while Present (Prag) loop
2201 Analyze_PPC_In_Decl_Part (Prag, Sent);
2202 Prag := Next_Pragma (Prag);
2205 Check_Subprogram_Contract (Sent);
2207 Prag := Spec_TC_List (Contract (Sent));
2208 while Present (Prag) loop
2209 Analyze_TC_In_Decl_Part (Prag, Sent);
2210 Prag := Next_Pragma (Prag);
2217 end Analyze_Declarations;
2219 -----------------------------------
2220 -- Analyze_Full_Type_Declaration --
2221 -----------------------------------
2223 procedure Analyze_Full_Type_Declaration (N : Node_Id) is
2224 Def : constant Node_Id := Type_Definition (N);
2225 Def_Id : constant Entity_Id := Defining_Identifier (N);
2229 Is_Remote : constant Boolean :=
2230 (Is_Remote_Types (Current_Scope)
2231 or else Is_Remote_Call_Interface (Current_Scope))
2232 and then not (In_Private_Part (Current_Scope)
2233 or else In_Package_Body (Current_Scope));
2235 procedure Check_Ops_From_Incomplete_Type;
2236 -- If there is a tagged incomplete partial view of the type, traverse
2237 -- the primitives of the incomplete view and change the type of any
2238 -- controlling formals and result to indicate the full view. The
2239 -- primitives will be added to the full type's primitive operations
2240 -- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which
2241 -- is called from Process_Incomplete_Dependents).
2243 ------------------------------------
2244 -- Check_Ops_From_Incomplete_Type --
2245 ------------------------------------
2247 procedure Check_Ops_From_Incomplete_Type is
2254 and then Ekind (Prev) = E_Incomplete_Type
2255 and then Is_Tagged_Type (Prev)
2256 and then Is_Tagged_Type (T)
2258 Elmt := First_Elmt (Primitive_Operations (Prev));
2259 while Present (Elmt) loop
2262 Formal := First_Formal (Op);
2263 while Present (Formal) loop
2264 if Etype (Formal) = Prev then
2265 Set_Etype (Formal, T);
2268 Next_Formal (Formal);
2271 if Etype (Op) = Prev then
2278 end Check_Ops_From_Incomplete_Type;
2280 -- Start of processing for Analyze_Full_Type_Declaration
2283 Prev := Find_Type_Name (N);
2285 -- The full view, if present, now points to the current type
2287 -- Ada 2005 (AI-50217): If the type was previously decorated when
2288 -- imported through a LIMITED WITH clause, it appears as incomplete
2289 -- but has no full view.
2291 if Ekind (Prev) = E_Incomplete_Type
2292 and then Present (Full_View (Prev))
2294 T := Full_View (Prev);
2299 Set_Is_Pure (T, Is_Pure (Current_Scope));
2301 -- We set the flag Is_First_Subtype here. It is needed to set the
2302 -- corresponding flag for the Implicit class-wide-type created
2303 -- during tagged types processing.
2305 Set_Is_First_Subtype (T, True);
2307 -- Only composite types other than array types are allowed to have
2312 -- For derived types, the rule will be checked once we've figured
2313 -- out the parent type.
2315 when N_Derived_Type_Definition =>
2318 -- For record types, discriminants are allowed, unless we are in
2321 when N_Record_Definition =>
2322 if Present (Discriminant_Specifications (N)) then
2323 Check_SPARK_Restriction
2324 ("discriminant type is not allowed",
2326 (First (Discriminant_Specifications (N))));
2330 if Present (Discriminant_Specifications (N)) then
2332 ("elementary or array type cannot have discriminants",
2334 (First (Discriminant_Specifications (N))));
2338 -- Elaborate the type definition according to kind, and generate
2339 -- subsidiary (implicit) subtypes where needed. We skip this if it was
2340 -- already done (this happens during the reanalysis that follows a call
2341 -- to the high level optimizer).
2343 if not Analyzed (T) then
2348 when N_Access_To_Subprogram_Definition =>
2349 Access_Subprogram_Declaration (T, Def);
2351 -- If this is a remote access to subprogram, we must create the
2352 -- equivalent fat pointer type, and related subprograms.
2355 Process_Remote_AST_Declaration (N);
2358 -- Validate categorization rule against access type declaration
2359 -- usually a violation in Pure unit, Shared_Passive unit.
2361 Validate_Access_Type_Declaration (T, N);
2363 when N_Access_To_Object_Definition =>
2364 Access_Type_Declaration (T, Def);
2366 -- Validate categorization rule against access type declaration
2367 -- usually a violation in Pure unit, Shared_Passive unit.
2369 Validate_Access_Type_Declaration (T, N);
2371 -- If we are in a Remote_Call_Interface package and define a
2372 -- RACW, then calling stubs and specific stream attributes
2376 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2378 Add_RACW_Features (Def_Id);
2381 -- Set no strict aliasing flag if config pragma seen
2383 if Opt.No_Strict_Aliasing then
2384 Set_No_Strict_Aliasing (Base_Type (Def_Id));
2387 when N_Array_Type_Definition =>
2388 Array_Type_Declaration (T, Def);
2390 when N_Derived_Type_Definition =>
2391 Derived_Type_Declaration (T, N, T /= Def_Id);
2393 when N_Enumeration_Type_Definition =>
2394 Enumeration_Type_Declaration (T, Def);
2396 when N_Floating_Point_Definition =>
2397 Floating_Point_Type_Declaration (T, Def);
2399 when N_Decimal_Fixed_Point_Definition =>
2400 Decimal_Fixed_Point_Type_Declaration (T, Def);
2402 when N_Ordinary_Fixed_Point_Definition =>
2403 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2405 when N_Signed_Integer_Type_Definition =>
2406 Signed_Integer_Type_Declaration (T, Def);
2408 when N_Modular_Type_Definition =>
2409 Modular_Type_Declaration (T, Def);
2411 when N_Record_Definition =>
2412 Record_Type_Declaration (T, N, Prev);
2414 -- If declaration has a parse error, nothing to elaborate.
2420 raise Program_Error;
2425 if Etype (T) = Any_Type then
2429 -- Controlled type is not allowed in SPARK
2431 if Is_Visibly_Controlled (T) then
2432 Check_SPARK_Restriction ("controlled type is not allowed", N);
2435 -- Some common processing for all types
2437 Set_Depends_On_Private (T, Has_Private_Component (T));
2438 Check_Ops_From_Incomplete_Type;
2440 -- Both the declared entity, and its anonymous base type if one
2441 -- was created, need freeze nodes allocated.
2444 B : constant Entity_Id := Base_Type (T);
2447 -- In the case where the base type differs from the first subtype, we
2448 -- pre-allocate a freeze node, and set the proper link to the first
2449 -- subtype. Freeze_Entity will use this preallocated freeze node when
2450 -- it freezes the entity.
2452 -- This does not apply if the base type is a generic type, whose
2453 -- declaration is independent of the current derived definition.
2455 if B /= T and then not Is_Generic_Type (B) then
2456 Ensure_Freeze_Node (B);
2457 Set_First_Subtype_Link (Freeze_Node (B), T);
2460 -- A type that is imported through a limited_with clause cannot
2461 -- generate any code, and thus need not be frozen. However, an access
2462 -- type with an imported designated type needs a finalization list,
2463 -- which may be referenced in some other package that has non-limited
2464 -- visibility on the designated type. Thus we must create the
2465 -- finalization list at the point the access type is frozen, to
2466 -- prevent unsatisfied references at link time.
2468 if not From_With_Type (T) or else Is_Access_Type (T) then
2469 Set_Has_Delayed_Freeze (T);
2473 -- Case where T is the full declaration of some private type which has
2474 -- been swapped in Defining_Identifier (N).
2476 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2477 Process_Full_View (N, T, Def_Id);
2479 -- Record the reference. The form of this is a little strange, since
2480 -- the full declaration has been swapped in. So the first parameter
2481 -- here represents the entity to which a reference is made which is
2482 -- the "real" entity, i.e. the one swapped in, and the second
2483 -- parameter provides the reference location.
2485 -- Also, we want to kill Has_Pragma_Unreferenced temporarily here
2486 -- since we don't want a complaint about the full type being an
2487 -- unwanted reference to the private type
2490 B : constant Boolean := Has_Pragma_Unreferenced (T);
2492 Set_Has_Pragma_Unreferenced (T, False);
2493 Generate_Reference (T, T, 'c');
2494 Set_Has_Pragma_Unreferenced (T, B);
2497 Set_Completion_Referenced (Def_Id);
2499 -- For completion of incomplete type, process incomplete dependents
2500 -- and always mark the full type as referenced (it is the incomplete
2501 -- type that we get for any real reference).
2503 elsif Ekind (Prev) = E_Incomplete_Type then
2504 Process_Incomplete_Dependents (N, T, Prev);
2505 Generate_Reference (Prev, Def_Id, 'c');
2506 Set_Completion_Referenced (Def_Id);
2508 -- If not private type or incomplete type completion, this is a real
2509 -- definition of a new entity, so record it.
2512 Generate_Definition (Def_Id);
2515 if Chars (Scope (Def_Id)) = Name_System
2516 and then Chars (Def_Id) = Name_Address
2517 and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N)))
2519 Set_Is_Descendent_Of_Address (Def_Id);
2520 Set_Is_Descendent_Of_Address (Base_Type (Def_Id));
2521 Set_Is_Descendent_Of_Address (Prev);
2524 Set_Optimize_Alignment_Flags (Def_Id);
2525 Check_Eliminated (Def_Id);
2527 -- If the declaration is a completion and aspects are present, apply
2528 -- them to the entity for the type which is currently the partial
2529 -- view, but which is the one that will be frozen.
2531 if Has_Aspects (N) then
2532 if Prev /= Def_Id then
2533 Analyze_Aspect_Specifications (N, Prev);
2535 Analyze_Aspect_Specifications (N, Def_Id);
2538 end Analyze_Full_Type_Declaration;
2540 ----------------------------------
2541 -- Analyze_Incomplete_Type_Decl --
2542 ----------------------------------
2544 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
2545 F : constant Boolean := Is_Pure (Current_Scope);
2549 Check_SPARK_Restriction ("incomplete type is not allowed", N);
2551 Generate_Definition (Defining_Identifier (N));
2553 -- Process an incomplete declaration. The identifier must not have been
2554 -- declared already in the scope. However, an incomplete declaration may
2555 -- appear in the private part of a package, for a private type that has
2556 -- already been declared.
2558 -- In this case, the discriminants (if any) must match
2560 T := Find_Type_Name (N);
2562 Set_Ekind (T, E_Incomplete_Type);
2563 Init_Size_Align (T);
2564 Set_Is_First_Subtype (T, True);
2567 -- Ada 2005 (AI-326): Minimum decoration to give support to tagged
2568 -- incomplete types.
2570 if Tagged_Present (N) then
2571 Set_Is_Tagged_Type (T);
2572 Make_Class_Wide_Type (T);
2573 Set_Direct_Primitive_Operations (T, New_Elmt_List);
2578 Set_Stored_Constraint (T, No_Elist);
2580 if Present (Discriminant_Specifications (N)) then
2581 Process_Discriminants (N);
2586 -- If the type has discriminants, non-trivial subtypes may be
2587 -- declared before the full view of the type. The full views of those
2588 -- subtypes will be built after the full view of the type.
2590 Set_Private_Dependents (T, New_Elmt_List);
2592 end Analyze_Incomplete_Type_Decl;
2594 -----------------------------------
2595 -- Analyze_Interface_Declaration --
2596 -----------------------------------
2598 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
2599 CW : constant Entity_Id := Class_Wide_Type (T);
2602 Set_Is_Tagged_Type (T);
2604 Set_Is_Limited_Record (T, Limited_Present (Def)
2605 or else Task_Present (Def)
2606 or else Protected_Present (Def)
2607 or else Synchronized_Present (Def));
2609 -- Type is abstract if full declaration carries keyword, or if previous
2610 -- partial view did.
2612 Set_Is_Abstract_Type (T);
2613 Set_Is_Interface (T);
2615 -- Type is a limited interface if it includes the keyword limited, task,
2616 -- protected, or synchronized.
2618 Set_Is_Limited_Interface
2619 (T, Limited_Present (Def)
2620 or else Protected_Present (Def)
2621 or else Synchronized_Present (Def)
2622 or else Task_Present (Def));
2624 Set_Interfaces (T, New_Elmt_List);
2625 Set_Direct_Primitive_Operations (T, New_Elmt_List);
2627 -- Complete the decoration of the class-wide entity if it was already
2628 -- built (i.e. during the creation of the limited view)
2630 if Present (CW) then
2631 Set_Is_Interface (CW);
2632 Set_Is_Limited_Interface (CW, Is_Limited_Interface (T));
2635 -- Check runtime support for synchronized interfaces
2637 if VM_Target = No_VM
2638 and then (Is_Task_Interface (T)
2639 or else Is_Protected_Interface (T)
2640 or else Is_Synchronized_Interface (T))
2641 and then not RTE_Available (RE_Select_Specific_Data)
2643 Error_Msg_CRT ("synchronized interfaces", T);
2645 end Analyze_Interface_Declaration;
2647 -----------------------------
2648 -- Analyze_Itype_Reference --
2649 -----------------------------
2651 -- Nothing to do. This node is placed in the tree only for the benefit of
2652 -- back end processing, and has no effect on the semantic processing.
2654 procedure Analyze_Itype_Reference (N : Node_Id) is
2656 pragma Assert (Is_Itype (Itype (N)));
2658 end Analyze_Itype_Reference;
2660 --------------------------------
2661 -- Analyze_Number_Declaration --
2662 --------------------------------
2664 procedure Analyze_Number_Declaration (N : Node_Id) is
2665 Id : constant Entity_Id := Defining_Identifier (N);
2666 E : constant Node_Id := Expression (N);
2668 Index : Interp_Index;
2672 Generate_Definition (Id);
2675 -- This is an optimization of a common case of an integer literal
2677 if Nkind (E) = N_Integer_Literal then
2678 Set_Is_Static_Expression (E, True);
2679 Set_Etype (E, Universal_Integer);
2681 Set_Etype (Id, Universal_Integer);
2682 Set_Ekind (Id, E_Named_Integer);
2683 Set_Is_Frozen (Id, True);
2687 Set_Is_Pure (Id, Is_Pure (Current_Scope));
2689 -- Process expression, replacing error by integer zero, to avoid
2690 -- cascaded errors or aborts further along in the processing
2692 -- Replace Error by integer zero, which seems least likely to cause
2696 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
2697 Set_Error_Posted (E);
2702 -- Verify that the expression is static and numeric. If
2703 -- the expression is overloaded, we apply the preference
2704 -- rule that favors root numeric types.
2706 if not Is_Overloaded (E) then
2712 Get_First_Interp (E, Index, It);
2713 while Present (It.Typ) loop
2714 if (Is_Integer_Type (It.Typ)
2715 or else Is_Real_Type (It.Typ))
2716 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
2718 if T = Any_Type then
2721 elsif It.Typ = Universal_Real
2722 or else It.Typ = Universal_Integer
2724 -- Choose universal interpretation over any other
2731 Get_Next_Interp (Index, It);
2735 if Is_Integer_Type (T) then
2737 Set_Etype (Id, Universal_Integer);
2738 Set_Ekind (Id, E_Named_Integer);
2740 elsif Is_Real_Type (T) then
2742 -- Because the real value is converted to universal_real, this is a
2743 -- legal context for a universal fixed expression.
2745 if T = Universal_Fixed then
2747 Loc : constant Source_Ptr := Sloc (N);
2748 Conv : constant Node_Id := Make_Type_Conversion (Loc,
2750 New_Occurrence_Of (Universal_Real, Loc),
2751 Expression => Relocate_Node (E));
2758 elsif T = Any_Fixed then
2759 Error_Msg_N ("illegal context for mixed mode operation", E);
2761 -- Expression is of the form : universal_fixed * integer. Try to
2762 -- resolve as universal_real.
2764 T := Universal_Real;
2769 Set_Etype (Id, Universal_Real);
2770 Set_Ekind (Id, E_Named_Real);
2773 Wrong_Type (E, Any_Numeric);
2777 Set_Ekind (Id, E_Constant);
2778 Set_Never_Set_In_Source (Id, True);
2779 Set_Is_True_Constant (Id, True);
2783 if Nkind_In (E, N_Integer_Literal, N_Real_Literal) then
2784 Set_Etype (E, Etype (Id));
2787 if not Is_OK_Static_Expression (E) then
2788 Flag_Non_Static_Expr
2789 ("non-static expression used in number declaration!", E);
2790 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
2791 Set_Etype (E, Any_Type);
2793 end Analyze_Number_Declaration;
2795 --------------------------------
2796 -- Analyze_Object_Declaration --
2797 --------------------------------
2799 procedure Analyze_Object_Declaration (N : Node_Id) is
2800 Loc : constant Source_Ptr := Sloc (N);
2801 Id : constant Entity_Id := Defining_Identifier (N);
2805 E : Node_Id := Expression (N);
2806 -- E is set to Expression (N) throughout this routine. When
2807 -- Expression (N) is modified, E is changed accordingly.
2809 Prev_Entity : Entity_Id := Empty;
2811 function Count_Tasks (T : Entity_Id) return Uint;
2812 -- This function is called when a non-generic library level object of a
2813 -- task type is declared. Its function is to count the static number of
2814 -- tasks declared within the type (it is only called if Has_Tasks is set
2815 -- for T). As a side effect, if an array of tasks with non-static bounds
2816 -- or a variant record type is encountered, Check_Restrictions is called
2817 -- indicating the count is unknown.
2823 function Count_Tasks (T : Entity_Id) return Uint is
2829 if Is_Task_Type (T) then
2832 elsif Is_Record_Type (T) then
2833 if Has_Discriminants (T) then
2834 Check_Restriction (Max_Tasks, N);
2839 C := First_Component (T);
2840 while Present (C) loop
2841 V := V + Count_Tasks (Etype (C));
2848 elsif Is_Array_Type (T) then
2849 X := First_Index (T);
2850 V := Count_Tasks (Component_Type (T));
2851 while Present (X) loop
2854 if not Is_Static_Subtype (C) then
2855 Check_Restriction (Max_Tasks, N);
2858 V := V * (UI_Max (Uint_0,
2859 Expr_Value (Type_High_Bound (C)) -
2860 Expr_Value (Type_Low_Bound (C)) + Uint_1));
2873 -- Start of processing for Analyze_Object_Declaration
2876 -- There are three kinds of implicit types generated by an
2877 -- object declaration:
2879 -- 1. Those generated by the original Object Definition
2881 -- 2. Those generated by the Expression
2883 -- 3. Those used to constrain the Object Definition with the
2884 -- expression constraints when the definition is unconstrained.
2886 -- They must be generated in this order to avoid order of elaboration
2887 -- issues. Thus the first step (after entering the name) is to analyze
2888 -- the object definition.
2890 if Constant_Present (N) then
2891 Prev_Entity := Current_Entity_In_Scope (Id);
2893 if Present (Prev_Entity)
2896 -- If the homograph is an implicit subprogram, it is overridden
2897 -- by the current declaration.
2899 ((Is_Overloadable (Prev_Entity)
2900 and then Is_Inherited_Operation (Prev_Entity))
2902 -- The current object is a discriminal generated for an entry
2903 -- family index. Even though the index is a constant, in this
2904 -- particular context there is no true constant redeclaration.
2905 -- Enter_Name will handle the visibility.
2908 (Is_Discriminal (Id)
2909 and then Ekind (Discriminal_Link (Id)) =
2910 E_Entry_Index_Parameter)
2912 -- The current object is the renaming for a generic declared
2913 -- within the instance.
2916 (Ekind (Prev_Entity) = E_Package
2917 and then Nkind (Parent (Prev_Entity)) =
2918 N_Package_Renaming_Declaration
2919 and then not Comes_From_Source (Prev_Entity)
2920 and then Is_Generic_Instance (Renamed_Entity (Prev_Entity))))
2922 Prev_Entity := Empty;
2926 if Present (Prev_Entity) then
2927 Constant_Redeclaration (Id, N, T);
2929 Generate_Reference (Prev_Entity, Id, 'c');
2930 Set_Completion_Referenced (Id);
2932 if Error_Posted (N) then
2934 -- Type mismatch or illegal redeclaration, Do not analyze
2935 -- expression to avoid cascaded errors.
2937 T := Find_Type_Of_Object (Object_Definition (N), N);
2939 Set_Ekind (Id, E_Variable);
2943 -- In the normal case, enter identifier at the start to catch premature
2944 -- usage in the initialization expression.
2947 Generate_Definition (Id);
2950 Mark_Coextensions (N, Object_Definition (N));
2952 T := Find_Type_Of_Object (Object_Definition (N), N);
2954 if Nkind (Object_Definition (N)) = N_Access_Definition
2956 (Access_To_Subprogram_Definition (Object_Definition (N)))
2957 and then Protected_Present
2958 (Access_To_Subprogram_Definition (Object_Definition (N)))
2960 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
2963 if Error_Posted (Id) then
2965 Set_Ekind (Id, E_Variable);
2970 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
2971 -- out some static checks
2973 if Ada_Version >= Ada_2005
2974 and then Can_Never_Be_Null (T)
2976 -- In case of aggregates we must also take care of the correct
2977 -- initialization of nested aggregates bug this is done at the
2978 -- point of the analysis of the aggregate (see sem_aggr.adb)
2980 if Present (Expression (N))
2981 and then Nkind (Expression (N)) = N_Aggregate
2987 Save_Typ : constant Entity_Id := Etype (Id);
2989 Set_Etype (Id, T); -- Temp. decoration for static checks
2990 Null_Exclusion_Static_Checks (N);
2991 Set_Etype (Id, Save_Typ);
2996 -- Object is marked pure if it is in a pure scope
2998 Set_Is_Pure (Id, Is_Pure (Current_Scope));
3000 -- If deferred constant, make sure context is appropriate. We detect
3001 -- a deferred constant as a constant declaration with no expression.
3002 -- A deferred constant can appear in a package body if its completion
3003 -- is by means of an interface pragma.
3005 if Constant_Present (N)
3008 -- A deferred constant may appear in the declarative part of the
3009 -- following constructs:
3013 -- extended return statements
3016 -- subprogram bodies
3019 -- When declared inside a package spec, a deferred constant must be
3020 -- completed by a full constant declaration or pragma Import. In all
3021 -- other cases, the only proper completion is pragma Import. Extended
3022 -- return statements are flagged as invalid contexts because they do
3023 -- not have a declarative part and so cannot accommodate the pragma.
3025 if Ekind (Current_Scope) = E_Return_Statement then
3027 ("invalid context for deferred constant declaration (RM 7.4)",
3030 ("\declaration requires an initialization expression",
3032 Set_Constant_Present (N, False);
3034 -- In Ada 83, deferred constant must be of private type
3036 elsif not Is_Private_Type (T) then
3037 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3039 ("(Ada 83) deferred constant must be private type", N);
3043 -- If not a deferred constant, then object declaration freezes its type
3046 Check_Fully_Declared (T, N);
3047 Freeze_Before (N, T);
3050 -- If the object was created by a constrained array definition, then
3051 -- set the link in both the anonymous base type and anonymous subtype
3052 -- that are built to represent the array type to point to the object.
3054 if Nkind (Object_Definition (Declaration_Node (Id))) =
3055 N_Constrained_Array_Definition
3057 Set_Related_Array_Object (T, Id);
3058 Set_Related_Array_Object (Base_Type (T), Id);
3061 -- Special checks for protected objects not at library level
3063 if Is_Protected_Type (T)
3064 and then not Is_Library_Level_Entity (Id)
3066 Check_Restriction (No_Local_Protected_Objects, Id);
3068 -- Protected objects with interrupt handlers must be at library level
3070 -- Ada 2005: this test is not needed (and the corresponding clause
3071 -- in the RM is removed) because accessibility checks are sufficient
3072 -- to make handlers not at the library level illegal.
3074 if Has_Interrupt_Handler (T)
3075 and then Ada_Version < Ada_2005
3078 ("interrupt object can only be declared at library level", Id);
3082 -- The actual subtype of the object is the nominal subtype, unless
3083 -- the nominal one is unconstrained and obtained from the expression.
3087 -- These checks should be performed before the initialization expression
3088 -- is considered, so that the Object_Definition node is still the same
3089 -- as in source code.
3091 -- In SPARK, the nominal subtype shall be given by a subtype mark and
3092 -- shall not be unconstrained. (The only exception to this is the
3093 -- admission of declarations of constants of type String.)
3096 Nkind_In (Object_Definition (N), N_Identifier, N_Expanded_Name)
3098 Check_SPARK_Restriction
3099 ("subtype mark required", Object_Definition (N));
3101 elsif Is_Array_Type (T)
3102 and then not Is_Constrained (T)
3103 and then T /= Standard_String
3105 Check_SPARK_Restriction
3106 ("subtype mark of constrained type expected",
3107 Object_Definition (N));
3110 -- There are no aliased objects in SPARK
3112 if Aliased_Present (N) then
3113 Check_SPARK_Restriction ("aliased object is not allowed", N);
3116 -- Process initialization expression if present and not in error
3118 if Present (E) and then E /= Error then
3120 -- Generate an error in case of CPP class-wide object initialization.
3121 -- Required because otherwise the expansion of the class-wide
3122 -- assignment would try to use 'size to initialize the object
3123 -- (primitive that is not available in CPP tagged types).
3125 if Is_Class_Wide_Type (Act_T)
3127 (Is_CPP_Class (Root_Type (Etype (Act_T)))
3129 (Present (Full_View (Root_Type (Etype (Act_T))))
3131 Is_CPP_Class (Full_View (Root_Type (Etype (Act_T))))))
3134 ("predefined assignment not available for 'C'P'P tagged types",
3138 Mark_Coextensions (N, E);
3141 -- In case of errors detected in the analysis of the expression,
3142 -- decorate it with the expected type to avoid cascaded errors
3144 if No (Etype (E)) then
3148 -- If an initialization expression is present, then we set the
3149 -- Is_True_Constant flag. It will be reset if this is a variable
3150 -- and it is indeed modified.
3152 Set_Is_True_Constant (Id, True);
3154 -- If we are analyzing a constant declaration, set its completion
3155 -- flag after analyzing and resolving the expression.
3157 if Constant_Present (N) then
3158 Set_Has_Completion (Id);
3161 -- Set type and resolve (type may be overridden later on)
3166 -- If E is null and has been replaced by an N_Raise_Constraint_Error
3167 -- node (which was marked already-analyzed), we need to set the type
3168 -- to something other than Any_Access in order to keep gigi happy.
3170 if Etype (E) = Any_Access then
3174 -- If the object is an access to variable, the initialization
3175 -- expression cannot be an access to constant.
3177 if Is_Access_Type (T)
3178 and then not Is_Access_Constant (T)
3179 and then Is_Access_Type (Etype (E))
3180 and then Is_Access_Constant (Etype (E))
3183 ("access to variable cannot be initialized "
3184 & "with an access-to-constant expression", E);
3187 if not Assignment_OK (N) then
3188 Check_Initialization (T, E);
3191 Check_Unset_Reference (E);
3193 -- If this is a variable, then set current value. If this is a
3194 -- declared constant of a scalar type with a static expression,
3195 -- indicate that it is always valid.
3197 if not Constant_Present (N) then
3198 if Compile_Time_Known_Value (E) then
3199 Set_Current_Value (Id, E);
3202 elsif Is_Scalar_Type (T)
3203 and then Is_OK_Static_Expression (E)
3205 Set_Is_Known_Valid (Id);
3208 -- Deal with setting of null flags
3210 if Is_Access_Type (T) then
3211 if Known_Non_Null (E) then
3212 Set_Is_Known_Non_Null (Id, True);
3213 elsif Known_Null (E)
3214 and then not Can_Never_Be_Null (Id)
3216 Set_Is_Known_Null (Id, True);
3220 -- Check incorrect use of dynamically tagged expressions.
3222 if Is_Tagged_Type (T) then
3223 Check_Dynamically_Tagged_Expression
3229 Apply_Scalar_Range_Check (E, T);
3230 Apply_Static_Length_Check (E, T);
3232 if Nkind (Original_Node (N)) = N_Object_Declaration
3233 and then Comes_From_Source (Original_Node (N))
3235 -- Only call test if needed
3237 and then Restriction_Check_Required (SPARK)
3238 and then not Is_SPARK_Initialization_Expr (E)
3240 Check_SPARK_Restriction
3241 ("initialization expression is not appropriate", E);
3245 -- If the No_Streams restriction is set, check that the type of the
3246 -- object is not, and does not contain, any subtype derived from
3247 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
3248 -- Has_Stream just for efficiency reasons. There is no point in
3249 -- spending time on a Has_Stream check if the restriction is not set.
3251 if Restriction_Check_Required (No_Streams) then
3252 if Has_Stream (T) then
3253 Check_Restriction (No_Streams, N);
3257 -- Deal with predicate check before we start to do major rewriting.
3258 -- it is OK to initialize and then check the initialized value, since
3259 -- the object goes out of scope if we get a predicate failure. Note
3260 -- that we do this in the analyzer and not the expander because the
3261 -- analyzer does some substantial rewriting in some cases.
3263 -- We need a predicate check if the type has predicates, and if either
3264 -- there is an initializing expression, or for default initialization
3265 -- when we have at least one case of an explicit default initial value.
3267 if not Suppress_Assignment_Checks (N)
3268 and then Present (Predicate_Function (T))
3272 Is_Partially_Initialized_Type (T, Include_Implicit => False))
3275 Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc)));
3278 -- Case of unconstrained type
3280 if Is_Indefinite_Subtype (T) then
3282 -- In SPARK, a declaration of unconstrained type is allowed
3283 -- only for constants of type string.
3285 if Is_String_Type (T) and then not Constant_Present (N) then
3286 Check_SPARK_Restriction
3287 ("declaration of object of unconstrained type not allowed",
3291 -- Nothing to do in deferred constant case
3293 if Constant_Present (N) and then No (E) then
3296 -- Case of no initialization present
3299 if No_Initialization (N) then
3302 elsif Is_Class_Wide_Type (T) then
3304 ("initialization required in class-wide declaration ", N);
3308 ("unconstrained subtype not allowed (need initialization)",
3309 Object_Definition (N));
3311 if Is_Record_Type (T) and then Has_Discriminants (T) then
3313 ("\provide initial value or explicit discriminant values",
3314 Object_Definition (N));
3317 ("\or give default discriminant values for type&",
3318 Object_Definition (N), T);
3320 elsif Is_Array_Type (T) then
3322 ("\provide initial value or explicit array bounds",
3323 Object_Definition (N));
3327 -- Case of initialization present but in error. Set initial
3328 -- expression as absent (but do not make above complaints)
3330 elsif E = Error then
3331 Set_Expression (N, Empty);
3334 -- Case of initialization present
3337 -- Check restrictions in Ada 83
3339 if not Constant_Present (N) then
3341 -- Unconstrained variables not allowed in Ada 83 mode
3343 if Ada_Version = Ada_83
3344 and then Comes_From_Source (Object_Definition (N))
3347 ("(Ada 83) unconstrained variable not allowed",
3348 Object_Definition (N));
3352 -- Now we constrain the variable from the initializing expression
3354 -- If the expression is an aggregate, it has been expanded into
3355 -- individual assignments. Retrieve the actual type from the
3356 -- expanded construct.
3358 if Is_Array_Type (T)
3359 and then No_Initialization (N)
3360 and then Nkind (Original_Node (E)) = N_Aggregate
3364 -- In case of class-wide interface object declarations we delay
3365 -- the generation of the equivalent record type declarations until
3366 -- its expansion because there are cases in they are not required.
3368 elsif Is_Interface (T) then
3372 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
3373 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
3376 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
3378 if Aliased_Present (N) then
3379 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
3382 Freeze_Before (N, Act_T);
3383 Freeze_Before (N, T);
3386 elsif Is_Array_Type (T)
3387 and then No_Initialization (N)
3388 and then Nkind (Original_Node (E)) = N_Aggregate
3390 if not Is_Entity_Name (Object_Definition (N)) then
3392 Check_Compile_Time_Size (Act_T);
3394 if Aliased_Present (N) then
3395 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
3399 -- When the given object definition and the aggregate are specified
3400 -- independently, and their lengths might differ do a length check.
3401 -- This cannot happen if the aggregate is of the form (others =>...)
3403 if not Is_Constrained (T) then
3406 elsif Nkind (E) = N_Raise_Constraint_Error then
3408 -- Aggregate is statically illegal. Place back in declaration
3410 Set_Expression (N, E);
3411 Set_No_Initialization (N, False);
3413 elsif T = Etype (E) then
3416 elsif Nkind (E) = N_Aggregate
3417 and then Present (Component_Associations (E))
3418 and then Present (Choices (First (Component_Associations (E))))
3419 and then Nkind (First
3420 (Choices (First (Component_Associations (E))))) = N_Others_Choice
3425 Apply_Length_Check (E, T);
3428 -- If the type is limited unconstrained with defaulted discriminants and
3429 -- there is no expression, then the object is constrained by the
3430 -- defaults, so it is worthwhile building the corresponding subtype.
3432 elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T))
3433 and then not Is_Constrained (T)
3434 and then Has_Discriminants (T)
3437 Act_T := Build_Default_Subtype (T, N);
3439 -- Ada 2005: a limited object may be initialized by means of an
3440 -- aggregate. If the type has default discriminants it has an
3441 -- unconstrained nominal type, Its actual subtype will be obtained
3442 -- from the aggregate, and not from the default discriminants.
3447 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
3449 elsif Present (Underlying_Type (T))
3450 and then not Is_Constrained (Underlying_Type (T))
3451 and then Has_Discriminants (Underlying_Type (T))
3452 and then Nkind (E) = N_Function_Call
3453 and then Constant_Present (N)
3455 -- The back-end has problems with constants of a discriminated type
3456 -- with defaults, if the initial value is a function call. We
3457 -- generate an intermediate temporary for the result of the call.
3458 -- It is unclear why this should make it acceptable to gcc. ???
3460 Remove_Side_Effects (E);
3462 -- If this is a constant declaration of an unconstrained type and
3463 -- the initialization is an aggregate, we can use the subtype of the
3464 -- aggregate for the declared entity because it is immutable.
3466 elsif not Is_Constrained (T)
3467 and then Has_Discriminants (T)
3468 and then Constant_Present (N)
3469 and then not Has_Unchecked_Union (T)
3470 and then Nkind (E) = N_Aggregate
3475 -- Check No_Wide_Characters restriction
3477 Check_Wide_Character_Restriction (T, Object_Definition (N));
3479 -- Indicate this is not set in source. Certainly true for constants, and
3480 -- true for variables so far (will be reset for a variable if and when
3481 -- we encounter a modification in the source).
3483 Set_Never_Set_In_Source (Id, True);
3485 -- Now establish the proper kind and type of the object
3487 if Constant_Present (N) then
3488 Set_Ekind (Id, E_Constant);
3489 Set_Is_True_Constant (Id, True);
3492 Set_Ekind (Id, E_Variable);
3494 -- A variable is set as shared passive if it appears in a shared
3495 -- passive package, and is at the outer level. This is not done for
3496 -- entities generated during expansion, because those are always
3497 -- manipulated locally.
3499 if Is_Shared_Passive (Current_Scope)
3500 and then Is_Library_Level_Entity (Id)
3501 and then Comes_From_Source (Id)
3503 Set_Is_Shared_Passive (Id);
3504 Check_Shared_Var (Id, T, N);
3507 -- Set Has_Initial_Value if initializing expression present. Note
3508 -- that if there is no initializing expression, we leave the state
3509 -- of this flag unchanged (usually it will be False, but notably in
3510 -- the case of exception choice variables, it will already be true).
3513 Set_Has_Initial_Value (Id, True);
3517 -- Initialize alignment and size and capture alignment setting
3519 Init_Alignment (Id);
3521 Set_Optimize_Alignment_Flags (Id);
3523 -- Deal with aliased case
3525 if Aliased_Present (N) then
3526 Set_Is_Aliased (Id);
3528 -- If the object is aliased and the type is unconstrained with
3529 -- defaulted discriminants and there is no expression, then the
3530 -- object is constrained by the defaults, so it is worthwhile
3531 -- building the corresponding subtype.
3533 -- Ada 2005 (AI-363): If the aliased object is discriminated and
3534 -- unconstrained, then only establish an actual subtype if the
3535 -- nominal subtype is indefinite. In definite cases the object is
3536 -- unconstrained in Ada 2005.
3539 and then Is_Record_Type (T)
3540 and then not Is_Constrained (T)
3541 and then Has_Discriminants (T)
3542 and then (Ada_Version < Ada_2005 or else Is_Indefinite_Subtype (T))
3544 Set_Actual_Subtype (Id, Build_Default_Subtype (T, N));
3548 -- Now we can set the type of the object
3550 Set_Etype (Id, Act_T);
3552 -- Object is marked to be treated as volatile if type is volatile and
3553 -- we clear the Current_Value setting that may have been set above.
3555 if Treat_As_Volatile (Etype (Id)) then
3556 Set_Treat_As_Volatile (Id);
3557 Set_Current_Value (Id, Empty);
3560 -- Deal with controlled types
3562 if Has_Controlled_Component (Etype (Id))
3563 or else Is_Controlled (Etype (Id))
3565 if not Is_Library_Level_Entity (Id) then
3566 Check_Restriction (No_Nested_Finalization, N);
3568 Validate_Controlled_Object (Id);
3571 -- Generate a warning when an initialization causes an obvious ABE
3572 -- violation. If the init expression is a simple aggregate there
3573 -- shouldn't be any initialize/adjust call generated. This will be
3574 -- true as soon as aggregates are built in place when possible.
3576 -- ??? at the moment we do not generate warnings for temporaries
3577 -- created for those aggregates although Program_Error might be
3578 -- generated if compiled with -gnato.
3580 if Is_Controlled (Etype (Id))
3581 and then Comes_From_Source (Id)
3584 BT : constant Entity_Id := Base_Type (Etype (Id));
3586 Implicit_Call : Entity_Id;
3587 pragma Warnings (Off, Implicit_Call);
3588 -- ??? what is this for (never referenced!)
3590 function Is_Aggr (N : Node_Id) return Boolean;
3591 -- Check that N is an aggregate
3597 function Is_Aggr (N : Node_Id) return Boolean is
3599 case Nkind (Original_Node (N)) is
3600 when N_Aggregate | N_Extension_Aggregate =>
3603 when N_Qualified_Expression |
3605 N_Unchecked_Type_Conversion =>
3606 return Is_Aggr (Expression (Original_Node (N)));
3614 -- If no underlying type, we already are in an error situation.
3615 -- Do not try to add a warning since we do not have access to
3618 if No (Underlying_Type (BT)) then
3619 Implicit_Call := Empty;
3621 -- A generic type does not have usable primitive operators.
3622 -- Initialization calls are built for instances.
3624 elsif Is_Generic_Type (BT) then
3625 Implicit_Call := Empty;
3627 -- If the init expression is not an aggregate, an adjust call
3628 -- will be generated
3630 elsif Present (E) and then not Is_Aggr (E) then
3631 Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
3633 -- If no init expression and we are not in the deferred
3634 -- constant case, an Initialize call will be generated
3636 elsif No (E) and then not Constant_Present (N) then
3637 Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
3640 Implicit_Call := Empty;
3646 if Has_Task (Etype (Id)) then
3647 Check_Restriction (No_Tasking, N);
3649 -- Deal with counting max tasks
3651 -- Nothing to do if inside a generic
3653 if Inside_A_Generic then
3656 -- If library level entity, then count tasks
3658 elsif Is_Library_Level_Entity (Id) then
3659 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
3661 -- If not library level entity, then indicate we don't know max
3662 -- tasks and also check task hierarchy restriction and blocking
3663 -- operation (since starting a task is definitely blocking!)
3666 Check_Restriction (Max_Tasks, N);
3667 Check_Restriction (No_Task_Hierarchy, N);
3668 Check_Potentially_Blocking_Operation (N);
3671 -- A rather specialized test. If we see two tasks being declared
3672 -- of the same type in the same object declaration, and the task
3673 -- has an entry with an address clause, we know that program error
3674 -- will be raised at run time since we can't have two tasks with
3675 -- entries at the same address.
3677 if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
3682 E := First_Entity (Etype (Id));
3683 while Present (E) loop
3684 if Ekind (E) = E_Entry
3685 and then Present (Get_Attribute_Definition_Clause
3686 (E, Attribute_Address))
3689 ("?more than one task with same entry address", N);
3691 ("\?Program_Error will be raised at run time", N);
3693 Make_Raise_Program_Error (Loc,
3694 Reason => PE_Duplicated_Entry_Address));
3704 -- Some simple constant-propagation: if the expression is a constant
3705 -- string initialized with a literal, share the literal. This avoids
3709 and then Is_Entity_Name (E)
3710 and then Ekind (Entity (E)) = E_Constant
3711 and then Base_Type (Etype (E)) = Standard_String
3714 Val : constant Node_Id := Constant_Value (Entity (E));
3717 and then Nkind (Val) = N_String_Literal
3719 Rewrite (E, New_Copy (Val));
3724 -- Another optimization: if the nominal subtype is unconstrained and
3725 -- the expression is a function call that returns an unconstrained
3726 -- type, rewrite the declaration as a renaming of the result of the
3727 -- call. The exceptions below are cases where the copy is expected,
3728 -- either by the back end (Aliased case) or by the semantics, as for
3729 -- initializing controlled types or copying tags for classwide types.
3732 and then Nkind (E) = N_Explicit_Dereference
3733 and then Nkind (Original_Node (E)) = N_Function_Call
3734 and then not Is_Library_Level_Entity (Id)
3735 and then not Is_Constrained (Underlying_Type (T))
3736 and then not Is_Aliased (Id)
3737 and then not Is_Class_Wide_Type (T)
3738 and then not Is_Controlled (T)
3739 and then not Has_Controlled_Component (Base_Type (T))
3740 and then Expander_Active
3743 Make_Object_Renaming_Declaration (Loc,
3744 Defining_Identifier => Id,
3745 Access_Definition => Empty,
3746 Subtype_Mark => New_Occurrence_Of
3747 (Base_Type (Etype (Id)), Loc),
3750 Set_Renamed_Object (Id, E);
3752 -- Force generation of debugging information for the constant and for
3753 -- the renamed function call.
3755 Set_Debug_Info_Needed (Id);
3756 Set_Debug_Info_Needed (Entity (Prefix (E)));
3759 if Present (Prev_Entity)
3760 and then Is_Frozen (Prev_Entity)
3761 and then not Error_Posted (Id)
3763 Error_Msg_N ("full constant declaration appears too late", N);
3766 Check_Eliminated (Id);
3768 -- Deal with setting In_Private_Part flag if in private part
3770 if Ekind (Scope (Id)) = E_Package
3771 and then In_Private_Part (Scope (Id))
3773 Set_In_Private_Part (Id);
3776 -- Check for violation of No_Local_Timing_Events
3778 if Restriction_Check_Required (No_Local_Timing_Events)
3779 and then not Is_Library_Level_Entity (Id)
3780 and then Is_RTE (Etype (Id), RE_Timing_Event)
3782 Check_Restriction (No_Local_Timing_Events, N);
3786 if Has_Aspects (N) then
3787 Analyze_Aspect_Specifications (N, Id);
3790 Analyze_Dimension (N);
3791 end Analyze_Object_Declaration;
3793 ---------------------------
3794 -- Analyze_Others_Choice --
3795 ---------------------------
3797 -- Nothing to do for the others choice node itself, the semantic analysis
3798 -- of the others choice will occur as part of the processing of the parent
3800 procedure Analyze_Others_Choice (N : Node_Id) is
3801 pragma Warnings (Off, N);
3804 end Analyze_Others_Choice;
3806 -------------------------------------------
3807 -- Analyze_Private_Extension_Declaration --
3808 -------------------------------------------
3810 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
3811 T : constant Entity_Id := Defining_Identifier (N);
3812 Indic : constant Node_Id := Subtype_Indication (N);
3813 Parent_Type : Entity_Id;
3814 Parent_Base : Entity_Id;
3817 -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
3819 if Is_Non_Empty_List (Interface_List (N)) then
3825 Intf := First (Interface_List (N));
3826 while Present (Intf) loop
3827 T := Find_Type_Of_Subtype_Indic (Intf);
3829 Diagnose_Interface (Intf, T);
3835 Generate_Definition (T);
3837 -- For other than Ada 2012, just enter the name in the current scope
3839 if Ada_Version < Ada_2012 then
3842 -- Ada 2012 (AI05-0162): Enter the name in the current scope handling
3843 -- case of private type that completes an incomplete type.
3850 Prev := Find_Type_Name (N);
3852 pragma Assert (Prev = T
3853 or else (Ekind (Prev) = E_Incomplete_Type
3854 and then Present (Full_View (Prev))
3855 and then Full_View (Prev) = T));
3859 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
3860 Parent_Base := Base_Type (Parent_Type);
3862 if Parent_Type = Any_Type
3863 or else Etype (Parent_Type) = Any_Type
3865 Set_Ekind (T, Ekind (Parent_Type));
3866 Set_Etype (T, Any_Type);
3869 elsif not Is_Tagged_Type (Parent_Type) then
3871 ("parent of type extension must be a tagged type ", Indic);
3874 elsif Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
3875 Error_Msg_N ("premature derivation of incomplete type", Indic);
3878 elsif Is_Concurrent_Type (Parent_Type) then
3880 ("parent type of a private extension cannot be "
3881 & "a synchronized tagged type (RM 3.9.1 (3/1))", N);
3883 Set_Etype (T, Any_Type);
3884 Set_Ekind (T, E_Limited_Private_Type);
3885 Set_Private_Dependents (T, New_Elmt_List);
3886 Set_Error_Posted (T);
3890 -- Perhaps the parent type should be changed to the class-wide type's
3891 -- specific type in this case to prevent cascading errors ???
3893 if Is_Class_Wide_Type (Parent_Type) then
3895 ("parent of type extension must not be a class-wide type", Indic);
3899 if (not Is_Package_Or_Generic_Package (Current_Scope)
3900 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
3901 or else In_Private_Part (Current_Scope)
3904 Error_Msg_N ("invalid context for private extension", N);
3907 -- Set common attributes
3909 Set_Is_Pure (T, Is_Pure (Current_Scope));
3910 Set_Scope (T, Current_Scope);
3911 Set_Ekind (T, E_Record_Type_With_Private);
3912 Init_Size_Align (T);
3914 Set_Etype (T, Parent_Base);
3915 Set_Has_Task (T, Has_Task (Parent_Base));
3917 Set_Convention (T, Convention (Parent_Type));
3918 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
3919 Set_Is_First_Subtype (T);
3920 Make_Class_Wide_Type (T);
3922 if Unknown_Discriminants_Present (N) then
3923 Set_Discriminant_Constraint (T, No_Elist);
3926 Build_Derived_Record_Type (N, Parent_Type, T);
3928 -- Propagate inherited invariant information. The new type has
3929 -- invariants, if the parent type has inheritable invariants,
3930 -- and these invariants can in turn be inherited.
3932 if Has_Inheritable_Invariants (Parent_Type) then
3933 Set_Has_Inheritable_Invariants (T);
3934 Set_Has_Invariants (T);
3937 -- Ada 2005 (AI-443): Synchronized private extension or a rewritten
3938 -- synchronized formal derived type.
3940 if Ada_Version >= Ada_2005
3941 and then Synchronized_Present (N)
3943 Set_Is_Limited_Record (T);
3945 -- Formal derived type case
3947 if Is_Generic_Type (T) then
3949 -- The parent must be a tagged limited type or a synchronized
3952 if (not Is_Tagged_Type (Parent_Type)
3953 or else not Is_Limited_Type (Parent_Type))
3955 (not Is_Interface (Parent_Type)
3956 or else not Is_Synchronized_Interface (Parent_Type))
3958 Error_Msg_NE ("parent type of & must be tagged limited " &
3959 "or synchronized", N, T);
3962 -- The progenitors (if any) must be limited or synchronized
3965 if Present (Interfaces (T)) then
3968 Iface_Elmt : Elmt_Id;
3971 Iface_Elmt := First_Elmt (Interfaces (T));
3972 while Present (Iface_Elmt) loop
3973 Iface := Node (Iface_Elmt);
3975 if not Is_Limited_Interface (Iface)
3976 and then not Is_Synchronized_Interface (Iface)
3978 Error_Msg_NE ("progenitor & must be limited " &
3979 "or synchronized", N, Iface);
3982 Next_Elmt (Iface_Elmt);
3987 -- Regular derived extension, the parent must be a limited or
3988 -- synchronized interface.
3991 if not Is_Interface (Parent_Type)
3992 or else (not Is_Limited_Interface (Parent_Type)
3994 not Is_Synchronized_Interface (Parent_Type))
3997 ("parent type of & must be limited interface", N, T);
4001 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
4002 -- extension with a synchronized parent must be explicitly declared
4003 -- synchronized, because the full view will be a synchronized type.
4004 -- This must be checked before the check for limited types below,
4005 -- to ensure that types declared limited are not allowed to extend
4006 -- synchronized interfaces.
4008 elsif Is_Interface (Parent_Type)
4009 and then Is_Synchronized_Interface (Parent_Type)
4010 and then not Synchronized_Present (N)
4013 ("private extension of& must be explicitly synchronized",
4016 elsif Limited_Present (N) then
4017 Set_Is_Limited_Record (T);
4019 if not Is_Limited_Type (Parent_Type)
4021 (not Is_Interface (Parent_Type)
4022 or else not Is_Limited_Interface (Parent_Type))
4024 Error_Msg_NE ("parent type& of limited extension must be limited",
4030 if Has_Aspects (N) then
4031 Analyze_Aspect_Specifications (N, T);
4033 end Analyze_Private_Extension_Declaration;
4035 ---------------------------------
4036 -- Analyze_Subtype_Declaration --
4037 ---------------------------------
4039 procedure Analyze_Subtype_Declaration
4041 Skip : Boolean := False)
4043 Id : constant Entity_Id := Defining_Identifier (N);
4045 R_Checks : Check_Result;
4048 Generate_Definition (Id);
4049 Set_Is_Pure (Id, Is_Pure (Current_Scope));
4050 Init_Size_Align (Id);
4052 -- The following guard condition on Enter_Name is to handle cases where
4053 -- the defining identifier has already been entered into the scope but
4054 -- the declaration as a whole needs to be analyzed.
4056 -- This case in particular happens for derived enumeration types. The
4057 -- derived enumeration type is processed as an inserted enumeration type
4058 -- declaration followed by a rewritten subtype declaration. The defining
4059 -- identifier, however, is entered into the name scope very early in the
4060 -- processing of the original type declaration and therefore needs to be
4061 -- avoided here, when the created subtype declaration is analyzed. (See
4062 -- Build_Derived_Types)
4064 -- This also happens when the full view of a private type is derived
4065 -- type with constraints. In this case the entity has been introduced
4066 -- in the private declaration.
4069 or else (Present (Etype (Id))
4070 and then (Is_Private_Type (Etype (Id))
4071 or else Is_Task_Type (Etype (Id))
4072 or else Is_Rewrite_Substitution (N)))
4080 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
4082 -- Class-wide equivalent types of records with unknown discriminants
4083 -- involve the generation of an itype which serves as the private view
4084 -- of a constrained record subtype. In such cases the base type of the
4085 -- current subtype we are processing is the private itype. Use the full
4086 -- of the private itype when decorating various attributes.
4089 and then Is_Private_Type (T)
4090 and then Present (Full_View (T))
4095 -- Inherit common attributes
4097 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
4098 Set_Is_Volatile (Id, Is_Volatile (T));
4099 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
4100 Set_Is_Atomic (Id, Is_Atomic (T));
4101 Set_Is_Ada_2005_Only (Id, Is_Ada_2005_Only (T));
4102 Set_Is_Ada_2012_Only (Id, Is_Ada_2012_Only (T));
4103 Set_Convention (Id, Convention (T));
4105 -- If ancestor has predicates then so does the subtype, and in addition
4106 -- we must delay the freeze to properly arrange predicate inheritance.
4108 -- The Ancestor_Type test is a big kludge, there seem to be cases in
4109 -- which T = ID, so the above tests and assignments do nothing???
4111 if Has_Predicates (T)
4112 or else (Present (Ancestor_Subtype (T))
4113 and then Has_Predicates (Ancestor_Subtype (T)))
4115 Set_Has_Predicates (Id);
4116 Set_Has_Delayed_Freeze (Id);
4119 -- Subtype of Boolean cannot have a constraint in SPARK
4121 if Is_Boolean_Type (T)
4122 and then Nkind (Subtype_Indication (N)) = N_Subtype_Indication
4124 Check_SPARK_Restriction
4125 ("subtype of Boolean cannot have constraint", N);
4128 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
4130 Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
4136 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint then
4137 One_Cstr := First (Constraints (Cstr));
4138 while Present (One_Cstr) loop
4140 -- Index or discriminant constraint in SPARK must be a
4144 Nkind_In (One_Cstr, N_Identifier, N_Expanded_Name)
4146 Check_SPARK_Restriction
4147 ("subtype mark required", One_Cstr);
4149 -- String subtype must have a lower bound of 1 in SPARK.
4150 -- Note that we do not need to test for the non-static case
4151 -- here, since that was already taken care of in
4152 -- Process_Range_Expr_In_Decl.
4154 elsif Base_Type (T) = Standard_String then
4155 Get_Index_Bounds (One_Cstr, Low, High);
4157 if Is_OK_Static_Expression (Low)
4158 and then Expr_Value (Low) /= 1
4160 Check_SPARK_Restriction
4161 ("String subtype must have lower bound of 1", N);
4171 -- In the case where there is no constraint given in the subtype
4172 -- indication, Process_Subtype just returns the Subtype_Mark, so its
4173 -- semantic attributes must be established here.
4175 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
4176 Set_Etype (Id, Base_Type (T));
4178 -- Subtype of unconstrained array without constraint is not allowed
4181 if Is_Array_Type (T)
4182 and then not Is_Constrained (T)
4184 Check_SPARK_Restriction
4185 ("subtype of unconstrained array must have constraint", N);
4190 Set_Ekind (Id, E_Array_Subtype);
4191 Copy_Array_Subtype_Attributes (Id, T);
4193 when Decimal_Fixed_Point_Kind =>
4194 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
4195 Set_Digits_Value (Id, Digits_Value (T));
4196 Set_Delta_Value (Id, Delta_Value (T));
4197 Set_Scale_Value (Id, Scale_Value (T));
4198 Set_Small_Value (Id, Small_Value (T));
4199 Set_Scalar_Range (Id, Scalar_Range (T));
4200 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
4201 Set_Is_Constrained (Id, Is_Constrained (T));
4202 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4203 Set_RM_Size (Id, RM_Size (T));
4205 when Enumeration_Kind =>
4206 Set_Ekind (Id, E_Enumeration_Subtype);
4207 Set_First_Literal (Id, First_Literal (Base_Type (T)));
4208 Set_Scalar_Range (Id, Scalar_Range (T));
4209 Set_Is_Character_Type (Id, Is_Character_Type (T));
4210 Set_Is_Constrained (Id, Is_Constrained (T));
4211 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4212 Set_RM_Size (Id, RM_Size (T));
4214 when Ordinary_Fixed_Point_Kind =>
4215 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
4216 Set_Scalar_Range (Id, Scalar_Range (T));
4217 Set_Small_Value (Id, Small_Value (T));
4218 Set_Delta_Value (Id, Delta_Value (T));
4219 Set_Is_Constrained (Id, Is_Constrained (T));
4220 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4221 Set_RM_Size (Id, RM_Size (T));
4224 Set_Ekind (Id, E_Floating_Point_Subtype);
4225 Set_Scalar_Range (Id, Scalar_Range (T));
4226 Set_Digits_Value (Id, Digits_Value (T));
4227 Set_Is_Constrained (Id, Is_Constrained (T));
4229 when Signed_Integer_Kind =>
4230 Set_Ekind (Id, E_Signed_Integer_Subtype);
4231 Set_Scalar_Range (Id, Scalar_Range (T));
4232 Set_Is_Constrained (Id, Is_Constrained (T));
4233 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4234 Set_RM_Size (Id, RM_Size (T));
4236 when Modular_Integer_Kind =>
4237 Set_Ekind (Id, E_Modular_Integer_Subtype);
4238 Set_Scalar_Range (Id, Scalar_Range (T));
4239 Set_Is_Constrained (Id, Is_Constrained (T));
4240 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4241 Set_RM_Size (Id, RM_Size (T));
4243 when Class_Wide_Kind =>
4244 Set_Ekind (Id, E_Class_Wide_Subtype);
4245 Set_First_Entity (Id, First_Entity (T));
4246 Set_Last_Entity (Id, Last_Entity (T));
4247 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4248 Set_Cloned_Subtype (Id, T);
4249 Set_Is_Tagged_Type (Id, True);
4250 Set_Has_Unknown_Discriminants
4253 if Ekind (T) = E_Class_Wide_Subtype then
4254 Set_Equivalent_Type (Id, Equivalent_Type (T));
4257 when E_Record_Type | E_Record_Subtype =>
4258 Set_Ekind (Id, E_Record_Subtype);
4260 if Ekind (T) = E_Record_Subtype
4261 and then Present (Cloned_Subtype (T))
4263 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
4265 Set_Cloned_Subtype (Id, T);
4268 Set_First_Entity (Id, First_Entity (T));
4269 Set_Last_Entity (Id, Last_Entity (T));
4270 Set_Has_Discriminants (Id, Has_Discriminants (T));
4271 Set_Is_Constrained (Id, Is_Constrained (T));
4272 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
4273 Set_Has_Implicit_Dereference
4274 (Id, Has_Implicit_Dereference (T));
4275 Set_Has_Unknown_Discriminants
4276 (Id, Has_Unknown_Discriminants (T));
4278 if Has_Discriminants (T) then
4279 Set_Discriminant_Constraint
4280 (Id, Discriminant_Constraint (T));
4281 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4283 elsif Has_Unknown_Discriminants (Id) then
4284 Set_Discriminant_Constraint (Id, No_Elist);
4287 if Is_Tagged_Type (T) then
4288 Set_Is_Tagged_Type (Id);
4289 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
4290 Set_Direct_Primitive_Operations
4291 (Id, Direct_Primitive_Operations (T));
4292 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4294 if Is_Interface (T) then
4295 Set_Is_Interface (Id);
4296 Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
4300 when Private_Kind =>
4301 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
4302 Set_Has_Discriminants (Id, Has_Discriminants (T));
4303 Set_Is_Constrained (Id, Is_Constrained (T));
4304 Set_First_Entity (Id, First_Entity (T));
4305 Set_Last_Entity (Id, Last_Entity (T));
4306 Set_Private_Dependents (Id, New_Elmt_List);
4307 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
4308 Set_Has_Implicit_Dereference
4309 (Id, Has_Implicit_Dereference (T));
4310 Set_Has_Unknown_Discriminants
4311 (Id, Has_Unknown_Discriminants (T));
4312 Set_Known_To_Have_Preelab_Init
4313 (Id, Known_To_Have_Preelab_Init (T));
4315 if Is_Tagged_Type (T) then
4316 Set_Is_Tagged_Type (Id);
4317 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
4318 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4319 Set_Direct_Primitive_Operations (Id,
4320 Direct_Primitive_Operations (T));
4323 -- In general the attributes of the subtype of a private type
4324 -- are the attributes of the partial view of parent. However,
4325 -- the full view may be a discriminated type, and the subtype
4326 -- must share the discriminant constraint to generate correct
4327 -- calls to initialization procedures.
4329 if Has_Discriminants (T) then
4330 Set_Discriminant_Constraint
4331 (Id, Discriminant_Constraint (T));
4332 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4334 elsif Present (Full_View (T))
4335 and then Has_Discriminants (Full_View (T))
4337 Set_Discriminant_Constraint
4338 (Id, Discriminant_Constraint (Full_View (T)));
4339 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4341 -- This would seem semantically correct, but apparently
4342 -- confuses the back-end. To be explained and checked with
4343 -- current version ???
4345 -- Set_Has_Discriminants (Id);
4348 Prepare_Private_Subtype_Completion (Id, N);
4351 Set_Ekind (Id, E_Access_Subtype);
4352 Set_Is_Constrained (Id, Is_Constrained (T));
4353 Set_Is_Access_Constant
4354 (Id, Is_Access_Constant (T));
4355 Set_Directly_Designated_Type
4356 (Id, Designated_Type (T));
4357 Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
4359 -- A Pure library_item must not contain the declaration of a
4360 -- named access type, except within a subprogram, generic
4361 -- subprogram, task unit, or protected unit, or if it has
4362 -- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)).
4364 if Comes_From_Source (Id)
4365 and then In_Pure_Unit
4366 and then not In_Subprogram_Task_Protected_Unit
4367 and then not No_Pool_Assigned (Id)
4370 ("named access types not allowed in pure unit", N);
4373 when Concurrent_Kind =>
4374 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
4375 Set_Corresponding_Record_Type (Id,
4376 Corresponding_Record_Type (T));
4377 Set_First_Entity (Id, First_Entity (T));
4378 Set_First_Private_Entity (Id, First_Private_Entity (T));
4379 Set_Has_Discriminants (Id, Has_Discriminants (T));
4380 Set_Is_Constrained (Id, Is_Constrained (T));
4381 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
4382 Set_Last_Entity (Id, Last_Entity (T));
4384 if Has_Discriminants (T) then
4385 Set_Discriminant_Constraint (Id,
4386 Discriminant_Constraint (T));
4387 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4390 when E_Incomplete_Type =>
4391 if Ada_Version >= Ada_2005 then
4392 Set_Ekind (Id, E_Incomplete_Subtype);
4394 -- Ada 2005 (AI-412): Decorate an incomplete subtype
4395 -- of an incomplete type visible through a limited
4398 if From_With_Type (T)
4399 and then Present (Non_Limited_View (T))
4401 Set_From_With_Type (Id);
4402 Set_Non_Limited_View (Id, Non_Limited_View (T));
4404 -- Ada 2005 (AI-412): Add the regular incomplete subtype
4405 -- to the private dependents of the original incomplete
4406 -- type for future transformation.
4409 Append_Elmt (Id, Private_Dependents (T));
4412 -- If the subtype name denotes an incomplete type an error
4413 -- was already reported by Process_Subtype.
4416 Set_Etype (Id, Any_Type);
4420 raise Program_Error;
4424 if Etype (Id) = Any_Type then
4428 -- Some common processing on all types
4430 Set_Size_Info (Id, T);
4431 Set_First_Rep_Item (Id, First_Rep_Item (T));
4435 Set_Is_Immediately_Visible (Id, True);
4436 Set_Depends_On_Private (Id, Has_Private_Component (T));
4437 Set_Is_Descendent_Of_Address (Id, Is_Descendent_Of_Address (T));
4439 if Is_Interface (T) then
4440 Set_Is_Interface (Id);
4443 if Present (Generic_Parent_Type (N))
4446 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
4448 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
4449 /= N_Formal_Private_Type_Definition)
4451 if Is_Tagged_Type (Id) then
4453 -- If this is a generic actual subtype for a synchronized type,
4454 -- the primitive operations are those of the corresponding record
4455 -- for which there is a separate subtype declaration.
4457 if Is_Concurrent_Type (Id) then
4459 elsif Is_Class_Wide_Type (Id) then
4460 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
4462 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
4465 elsif Scope (Etype (Id)) /= Standard_Standard then
4466 Derive_Subprograms (Generic_Parent_Type (N), Id);
4470 if Is_Private_Type (T)
4471 and then Present (Full_View (T))
4473 Conditional_Delay (Id, Full_View (T));
4475 -- The subtypes of components or subcomponents of protected types
4476 -- do not need freeze nodes, which would otherwise appear in the
4477 -- wrong scope (before the freeze node for the protected type). The
4478 -- proper subtypes are those of the subcomponents of the corresponding
4481 elsif Ekind (Scope (Id)) /= E_Protected_Type
4482 and then Present (Scope (Scope (Id))) -- error defense!
4483 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
4485 Conditional_Delay (Id, T);
4488 -- Check that Constraint_Error is raised for a scalar subtype indication
4489 -- when the lower or upper bound of a non-null range lies outside the
4490 -- range of the type mark.
4492 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
4493 if Is_Scalar_Type (Etype (Id))
4494 and then Scalar_Range (Id) /=
4495 Scalar_Range (Etype (Subtype_Mark
4496 (Subtype_Indication (N))))
4500 Etype (Subtype_Mark (Subtype_Indication (N))));
4502 -- In the array case, check compatibility for each index
4504 elsif Is_Array_Type (Etype (Id))
4505 and then Present (First_Index (Id))
4507 -- This really should be a subprogram that finds the indications
4511 Subt_Index : Node_Id := First_Index (Id);
4512 Target_Index : Node_Id :=
4514 (Subtype_Mark (Subtype_Indication (N))));
4515 Has_Dyn_Chk : Boolean := Has_Dynamic_Range_Check (N);
4518 while Present (Subt_Index) loop
4519 if ((Nkind (Subt_Index) = N_Identifier
4520 and then Ekind (Entity (Subt_Index)) in Scalar_Kind)
4521 or else Nkind (Subt_Index) = N_Subtype_Indication)
4523 Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range
4526 Target_Typ : constant Entity_Id :=
4527 Etype (Target_Index);
4531 (Scalar_Range (Etype (Subt_Index)),
4534 Defining_Identifier (N));
4536 -- Reset Has_Dynamic_Range_Check on the subtype to
4537 -- prevent elision of the index check due to a dynamic
4538 -- check generated for a preceding index (needed since
4539 -- Insert_Range_Checks tries to avoid generating
4540 -- redundant checks on a given declaration).
4542 Set_Has_Dynamic_Range_Check (N, False);
4548 Sloc (Defining_Identifier (N)));
4550 -- Record whether this index involved a dynamic check
4553 Has_Dyn_Chk or else Has_Dynamic_Range_Check (N);
4557 Next_Index (Subt_Index);
4558 Next_Index (Target_Index);
4561 -- Finally, mark whether the subtype involves dynamic checks
4563 Set_Has_Dynamic_Range_Check (N, Has_Dyn_Chk);
4568 -- Make sure that generic actual types are properly frozen. The subtype
4569 -- is marked as a generic actual type when the enclosing instance is
4570 -- analyzed, so here we identify the subtype from the tree structure.
4573 and then Is_Generic_Actual_Type (Id)
4574 and then In_Instance
4575 and then not Comes_From_Source (N)
4576 and then Nkind (Subtype_Indication (N)) /= N_Subtype_Indication
4577 and then Is_Frozen (T)
4579 Freeze_Before (N, Id);
4582 Set_Optimize_Alignment_Flags (Id);
4583 Check_Eliminated (Id);
4586 if Has_Aspects (N) then
4587 Analyze_Aspect_Specifications (N, Id);
4590 Analyze_Dimension (N);
4591 end Analyze_Subtype_Declaration;
4593 --------------------------------
4594 -- Analyze_Subtype_Indication --
4595 --------------------------------
4597 procedure Analyze_Subtype_Indication (N : Node_Id) is
4598 T : constant Entity_Id := Subtype_Mark (N);
4599 R : constant Node_Id := Range_Expression (Constraint (N));
4606 Set_Etype (N, Etype (R));
4607 Resolve (R, Entity (T));
4609 Set_Error_Posted (R);
4610 Set_Error_Posted (T);
4612 end Analyze_Subtype_Indication;
4614 --------------------------
4615 -- Analyze_Variant_Part --
4616 --------------------------
4618 procedure Analyze_Variant_Part (N : Node_Id) is
4620 procedure Non_Static_Choice_Error (Choice : Node_Id);
4621 -- Error routine invoked by the generic instantiation below when the
4622 -- variant part has a non static choice.
4624 procedure Process_Declarations (Variant : Node_Id);
4625 -- Analyzes all the declarations associated with a Variant. Needed by
4626 -- the generic instantiation below.
4628 package Variant_Choices_Processing is new
4629 Generic_Choices_Processing
4630 (Get_Alternatives => Variants,
4631 Get_Choices => Discrete_Choices,
4632 Process_Empty_Choice => No_OP,
4633 Process_Non_Static_Choice => Non_Static_Choice_Error,
4634 Process_Associated_Node => Process_Declarations);
4635 use Variant_Choices_Processing;
4636 -- Instantiation of the generic choice processing package
4638 -----------------------------
4639 -- Non_Static_Choice_Error --
4640 -----------------------------
4642 procedure Non_Static_Choice_Error (Choice : Node_Id) is
4644 Flag_Non_Static_Expr
4645 ("choice given in variant part is not static!", Choice);
4646 end Non_Static_Choice_Error;
4648 --------------------------
4649 -- Process_Declarations --
4650 --------------------------
4652 procedure Process_Declarations (Variant : Node_Id) is
4654 if not Null_Present (Component_List (Variant)) then
4655 Analyze_Declarations (Component_Items (Component_List (Variant)));
4657 if Present (Variant_Part (Component_List (Variant))) then
4658 Analyze (Variant_Part (Component_List (Variant)));
4661 end Process_Declarations;
4665 Discr_Name : Node_Id;
4666 Discr_Type : Entity_Id;
4668 Dont_Care : Boolean;
4669 Others_Present : Boolean := False;
4671 pragma Warnings (Off, Dont_Care);
4672 pragma Warnings (Off, Others_Present);
4673 -- We don't care about the assigned values of any of these
4675 -- Start of processing for Analyze_Variant_Part
4678 Discr_Name := Name (N);
4679 Analyze (Discr_Name);
4681 -- If Discr_Name bad, get out (prevent cascaded errors)
4683 if Etype (Discr_Name) = Any_Type then
4687 -- Check invalid discriminant in variant part
4689 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
4690 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
4693 Discr_Type := Etype (Entity (Discr_Name));
4695 if not Is_Discrete_Type (Discr_Type) then
4697 ("discriminant in a variant part must be of a discrete type",
4702 -- Call the instantiated Analyze_Choices which does the rest of the work
4704 Analyze_Choices (N, Discr_Type, Dont_Care, Others_Present);
4705 end Analyze_Variant_Part;
4707 ----------------------------
4708 -- Array_Type_Declaration --
4709 ----------------------------
4711 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
4712 Component_Def : constant Node_Id := Component_Definition (Def);
4713 Component_Typ : constant Node_Id := Subtype_Indication (Component_Def);
4714 Element_Type : Entity_Id;
4715 Implicit_Base : Entity_Id;
4717 Related_Id : Entity_Id := Empty;
4719 P : constant Node_Id := Parent (Def);
4723 if Nkind (Def) = N_Constrained_Array_Definition then
4724 Index := First (Discrete_Subtype_Definitions (Def));
4726 Index := First (Subtype_Marks (Def));
4729 -- Find proper names for the implicit types which may be public. In case
4730 -- of anonymous arrays we use the name of the first object of that type
4734 Related_Id := Defining_Identifier (P);
4740 while Present (Index) loop
4743 if not Nkind_In (Index, N_Identifier, N_Expanded_Name) then
4744 Check_SPARK_Restriction ("subtype mark required", Index);
4747 -- Add a subtype declaration for each index of private array type
4748 -- declaration whose etype is also private. For example:
4751 -- type Index is private;
4753 -- type Table is array (Index) of ...
4756 -- This is currently required by the expander for the internally
4757 -- generated equality subprogram of records with variant parts in
4758 -- which the etype of some component is such private type.
4760 if Ekind (Current_Scope) = E_Package
4761 and then In_Private_Part (Current_Scope)
4762 and then Has_Private_Declaration (Etype (Index))
4765 Loc : constant Source_Ptr := Sloc (Def);
4770 New_E := Make_Temporary (Loc, 'T');
4771 Set_Is_Internal (New_E);
4774 Make_Subtype_Declaration (Loc,
4775 Defining_Identifier => New_E,
4776 Subtype_Indication =>
4777 New_Occurrence_Of (Etype (Index), Loc));
4779 Insert_Before (Parent (Def), Decl);
4781 Set_Etype (Index, New_E);
4783 -- If the index is a range the Entity attribute is not
4784 -- available. Example:
4787 -- type T is private;
4789 -- type T is new Natural;
4790 -- Table : array (T(1) .. T(10)) of Boolean;
4793 if Nkind (Index) /= N_Range then
4794 Set_Entity (Index, New_E);
4799 Make_Index (Index, P, Related_Id, Nb_Index);
4801 -- Check error of subtype with predicate for index type
4803 Bad_Predicated_Subtype_Use
4804 ("subtype& has predicate, not allowed as index subtype",
4805 Index, Etype (Index));
4807 -- Move to next index
4810 Nb_Index := Nb_Index + 1;
4813 -- Process subtype indication if one is present
4815 if Present (Component_Typ) then
4816 Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C');
4818 Set_Etype (Component_Typ, Element_Type);
4820 if not Nkind_In (Component_Typ, N_Identifier, N_Expanded_Name) then
4821 Check_SPARK_Restriction ("subtype mark required", Component_Typ);
4824 -- Ada 2005 (AI-230): Access Definition case
4826 else pragma Assert (Present (Access_Definition (Component_Def)));
4828 -- Indicate that the anonymous access type is created by the
4829 -- array type declaration.
4831 Element_Type := Access_Definition
4833 N => Access_Definition (Component_Def));
4834 Set_Is_Local_Anonymous_Access (Element_Type);
4836 -- Propagate the parent. This field is needed if we have to generate
4837 -- the master_id associated with an anonymous access to task type
4838 -- component (see Expand_N_Full_Type_Declaration.Build_Master)
4840 Set_Parent (Element_Type, Parent (T));
4842 -- Ada 2005 (AI-230): In case of components that are anonymous access
4843 -- types the level of accessibility depends on the enclosing type
4846 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
4848 -- Ada 2005 (AI-254)
4851 CD : constant Node_Id :=
4852 Access_To_Subprogram_Definition
4853 (Access_Definition (Component_Def));
4855 if Present (CD) and then Protected_Present (CD) then
4857 Replace_Anonymous_Access_To_Protected_Subprogram (Def);
4862 -- Constrained array case
4865 T := Create_Itype (E_Void, P, Related_Id, 'T');
4868 if Nkind (Def) = N_Constrained_Array_Definition then
4870 -- Establish Implicit_Base as unconstrained base type
4872 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
4874 Set_Etype (Implicit_Base, Implicit_Base);
4875 Set_Scope (Implicit_Base, Current_Scope);
4876 Set_Has_Delayed_Freeze (Implicit_Base);
4878 -- The constrained array type is a subtype of the unconstrained one
4880 Set_Ekind (T, E_Array_Subtype);
4881 Init_Size_Align (T);
4882 Set_Etype (T, Implicit_Base);
4883 Set_Scope (T, Current_Scope);
4884 Set_Is_Constrained (T, True);
4885 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
4886 Set_Has_Delayed_Freeze (T);
4888 -- Complete setup of implicit base type
4890 Set_First_Index (Implicit_Base, First_Index (T));
4891 Set_Component_Type (Implicit_Base, Element_Type);
4892 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
4893 Set_Component_Size (Implicit_Base, Uint_0);
4894 Set_Packed_Array_Type (Implicit_Base, Empty);
4895 Set_Has_Controlled_Component
4896 (Implicit_Base, Has_Controlled_Component
4898 or else Is_Controlled
4900 Set_Finalize_Storage_Only
4901 (Implicit_Base, Finalize_Storage_Only
4904 -- Unconstrained array case
4907 Set_Ekind (T, E_Array_Type);
4908 Init_Size_Align (T);
4910 Set_Scope (T, Current_Scope);
4911 Set_Component_Size (T, Uint_0);
4912 Set_Is_Constrained (T, False);
4913 Set_First_Index (T, First (Subtype_Marks (Def)));
4914 Set_Has_Delayed_Freeze (T, True);
4915 Set_Has_Task (T, Has_Task (Element_Type));
4916 Set_Has_Controlled_Component (T, Has_Controlled_Component
4919 Is_Controlled (Element_Type));
4920 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
4924 -- Common attributes for both cases
4926 Set_Component_Type (Base_Type (T), Element_Type);
4927 Set_Packed_Array_Type (T, Empty);
4929 if Aliased_Present (Component_Definition (Def)) then
4930 Check_SPARK_Restriction
4931 ("aliased is not allowed", Component_Definition (Def));
4932 Set_Has_Aliased_Components (Etype (T));
4935 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
4936 -- array type to ensure that objects of this type are initialized.
4938 if Ada_Version >= Ada_2005
4939 and then Can_Never_Be_Null (Element_Type)
4941 Set_Can_Never_Be_Null (T);
4943 if Null_Exclusion_Present (Component_Definition (Def))
4945 -- No need to check itypes because in their case this check was
4946 -- done at their point of creation
4948 and then not Is_Itype (Element_Type)
4951 ("`NOT NULL` not allowed (null already excluded)",
4952 Subtype_Indication (Component_Definition (Def)));
4956 Priv := Private_Component (Element_Type);
4958 if Present (Priv) then
4960 -- Check for circular definitions
4962 if Priv = Any_Type then
4963 Set_Component_Type (Etype (T), Any_Type);
4965 -- There is a gap in the visibility of operations on the composite
4966 -- type only if the component type is defined in a different scope.
4968 elsif Scope (Priv) = Current_Scope then
4971 elsif Is_Limited_Type (Priv) then
4972 Set_Is_Limited_Composite (Etype (T));
4973 Set_Is_Limited_Composite (T);
4975 Set_Is_Private_Composite (Etype (T));
4976 Set_Is_Private_Composite (T);
4980 -- A syntax error in the declaration itself may lead to an empty index
4981 -- list, in which case do a minimal patch.
4983 if No (First_Index (T)) then
4984 Error_Msg_N ("missing index definition in array type declaration", T);
4987 Indexes : constant List_Id :=
4988 New_List (New_Occurrence_Of (Any_Id, Sloc (T)));
4990 Set_Discrete_Subtype_Definitions (Def, Indexes);
4991 Set_First_Index (T, First (Indexes));
4996 -- Create a concatenation operator for the new type. Internal array
4997 -- types created for packed entities do not need such, they are
4998 -- compatible with the user-defined type.
5000 if Number_Dimensions (T) = 1
5001 and then not Is_Packed_Array_Type (T)
5003 New_Concatenation_Op (T);
5006 -- In the case of an unconstrained array the parser has already verified
5007 -- that all the indexes are unconstrained but we still need to make sure
5008 -- that the element type is constrained.
5010 if Is_Indefinite_Subtype (Element_Type) then
5012 ("unconstrained element type in array declaration",
5013 Subtype_Indication (Component_Def));
5015 elsif Is_Abstract_Type (Element_Type) then
5017 ("the type of a component cannot be abstract",
5018 Subtype_Indication (Component_Def));
5020 end Array_Type_Declaration;
5022 ------------------------------------------------------
5023 -- Replace_Anonymous_Access_To_Protected_Subprogram --
5024 ------------------------------------------------------
5026 function Replace_Anonymous_Access_To_Protected_Subprogram
5027 (N : Node_Id) return Entity_Id
5029 Loc : constant Source_Ptr := Sloc (N);
5031 Curr_Scope : constant Scope_Stack_Entry :=
5032 Scope_Stack.Table (Scope_Stack.Last);
5034 Anon : constant Entity_Id := Make_Temporary (Loc, 'S');
5041 Set_Is_Internal (Anon);
5044 when N_Component_Declaration |
5045 N_Unconstrained_Array_Definition |
5046 N_Constrained_Array_Definition =>
5047 Comp := Component_Definition (N);
5048 Acc := Access_Definition (Comp);
5050 when N_Discriminant_Specification =>
5051 Comp := Discriminant_Type (N);
5054 when N_Parameter_Specification =>
5055 Comp := Parameter_Type (N);
5058 when N_Access_Function_Definition =>
5059 Comp := Result_Definition (N);
5062 when N_Object_Declaration =>
5063 Comp := Object_Definition (N);
5066 when N_Function_Specification =>
5067 Comp := Result_Definition (N);
5071 raise Program_Error;
5074 Decl := Make_Full_Type_Declaration (Loc,
5075 Defining_Identifier => Anon,
5077 Copy_Separate_Tree (Access_To_Subprogram_Definition (Acc)));
5079 Mark_Rewrite_Insertion (Decl);
5081 -- Insert the new declaration in the nearest enclosing scope. If the
5082 -- node is a body and N is its return type, the declaration belongs in
5083 -- the enclosing scope.
5087 if Nkind (P) = N_Subprogram_Body
5088 and then Nkind (N) = N_Function_Specification
5093 while Present (P) and then not Has_Declarations (P) loop
5097 pragma Assert (Present (P));
5099 if Nkind (P) = N_Package_Specification then
5100 Prepend (Decl, Visible_Declarations (P));
5102 Prepend (Decl, Declarations (P));
5105 -- Replace the anonymous type with an occurrence of the new declaration.
5106 -- In all cases the rewritten node does not have the null-exclusion
5107 -- attribute because (if present) it was already inherited by the
5108 -- anonymous entity (Anon). Thus, in case of components we do not
5109 -- inherit this attribute.
5111 if Nkind (N) = N_Parameter_Specification then
5112 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5113 Set_Etype (Defining_Identifier (N), Anon);
5114 Set_Null_Exclusion_Present (N, False);
5116 elsif Nkind (N) = N_Object_Declaration then
5117 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5118 Set_Etype (Defining_Identifier (N), Anon);
5120 elsif Nkind (N) = N_Access_Function_Definition then
5121 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5123 elsif Nkind (N) = N_Function_Specification then
5124 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5125 Set_Etype (Defining_Unit_Name (N), Anon);
5129 Make_Component_Definition (Loc,
5130 Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
5133 Mark_Rewrite_Insertion (Comp);
5135 if Nkind_In (N, N_Object_Declaration, N_Access_Function_Definition) then
5139 -- Temporarily remove the current scope (record or subprogram) from
5140 -- the stack to add the new declarations to the enclosing scope.
5142 Scope_Stack.Decrement_Last;
5144 Set_Is_Itype (Anon);
5145 Scope_Stack.Append (Curr_Scope);
5148 Set_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type);
5149 Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target);
5151 end Replace_Anonymous_Access_To_Protected_Subprogram;
5153 -------------------------------
5154 -- Build_Derived_Access_Type --
5155 -------------------------------
5157 procedure Build_Derived_Access_Type
5159 Parent_Type : Entity_Id;
5160 Derived_Type : Entity_Id)
5162 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
5164 Desig_Type : Entity_Id;
5166 Discr_Con_Elist : Elist_Id;
5167 Discr_Con_El : Elmt_Id;
5171 -- Set the designated type so it is available in case this is an access
5172 -- to a self-referential type, e.g. a standard list type with a next
5173 -- pointer. Will be reset after subtype is built.
5175 Set_Directly_Designated_Type
5176 (Derived_Type, Designated_Type (Parent_Type));
5178 Subt := Process_Subtype (S, N);
5180 if Nkind (S) /= N_Subtype_Indication
5181 and then Subt /= Base_Type (Subt)
5183 Set_Ekind (Derived_Type, E_Access_Subtype);
5186 if Ekind (Derived_Type) = E_Access_Subtype then
5188 Pbase : constant Entity_Id := Base_Type (Parent_Type);
5189 Ibase : constant Entity_Id :=
5190 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
5191 Svg_Chars : constant Name_Id := Chars (Ibase);
5192 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
5195 Copy_Node (Pbase, Ibase);
5197 Set_Chars (Ibase, Svg_Chars);
5198 Set_Next_Entity (Ibase, Svg_Next_E);
5199 Set_Sloc (Ibase, Sloc (Derived_Type));
5200 Set_Scope (Ibase, Scope (Derived_Type));
5201 Set_Freeze_Node (Ibase, Empty);
5202 Set_Is_Frozen (Ibase, False);
5203 Set_Comes_From_Source (Ibase, False);
5204 Set_Is_First_Subtype (Ibase, False);
5206 Set_Etype (Ibase, Pbase);
5207 Set_Etype (Derived_Type, Ibase);
5211 Set_Directly_Designated_Type
5212 (Derived_Type, Designated_Type (Subt));
5214 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
5215 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
5216 Set_Size_Info (Derived_Type, Parent_Type);
5217 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5218 Set_Depends_On_Private (Derived_Type,
5219 Has_Private_Component (Derived_Type));
5220 Conditional_Delay (Derived_Type, Subt);
5222 -- Ada 2005 (AI-231): Set the null-exclusion attribute, and verify
5223 -- that it is not redundant.
5225 if Null_Exclusion_Present (Type_Definition (N)) then
5226 Set_Can_Never_Be_Null (Derived_Type);
5228 if Can_Never_Be_Null (Parent_Type)
5232 ("`NOT NULL` not allowed (& already excludes null)",
5236 elsif Can_Never_Be_Null (Parent_Type) then
5237 Set_Can_Never_Be_Null (Derived_Type);
5240 -- Note: we do not copy the Storage_Size_Variable, since we always go to
5241 -- the root type for this information.
5243 -- Apply range checks to discriminants for derived record case
5244 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
5246 Desig_Type := Designated_Type (Derived_Type);
5247 if Is_Composite_Type (Desig_Type)
5248 and then (not Is_Array_Type (Desig_Type))
5249 and then Has_Discriminants (Desig_Type)
5250 and then Base_Type (Desig_Type) /= Desig_Type
5252 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
5253 Discr_Con_El := First_Elmt (Discr_Con_Elist);
5255 Discr := First_Discriminant (Base_Type (Desig_Type));
5256 while Present (Discr_Con_El) loop
5257 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
5258 Next_Elmt (Discr_Con_El);
5259 Next_Discriminant (Discr);
5262 end Build_Derived_Access_Type;
5264 ------------------------------
5265 -- Build_Derived_Array_Type --
5266 ------------------------------
5268 procedure Build_Derived_Array_Type
5270 Parent_Type : Entity_Id;
5271 Derived_Type : Entity_Id)
5273 Loc : constant Source_Ptr := Sloc (N);
5274 Tdef : constant Node_Id := Type_Definition (N);
5275 Indic : constant Node_Id := Subtype_Indication (Tdef);
5276 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5277 Implicit_Base : Entity_Id;
5278 New_Indic : Node_Id;
5280 procedure Make_Implicit_Base;
5281 -- If the parent subtype is constrained, the derived type is a subtype
5282 -- of an implicit base type derived from the parent base.
5284 ------------------------
5285 -- Make_Implicit_Base --
5286 ------------------------
5288 procedure Make_Implicit_Base is
5291 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
5293 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
5294 Set_Etype (Implicit_Base, Parent_Base);
5296 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
5297 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
5299 Set_Has_Delayed_Freeze (Implicit_Base, True);
5300 end Make_Implicit_Base;
5302 -- Start of processing for Build_Derived_Array_Type
5305 if not Is_Constrained (Parent_Type) then
5306 if Nkind (Indic) /= N_Subtype_Indication then
5307 Set_Ekind (Derived_Type, E_Array_Type);
5309 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
5310 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
5312 Set_Has_Delayed_Freeze (Derived_Type, True);
5316 Set_Etype (Derived_Type, Implicit_Base);
5319 Make_Subtype_Declaration (Loc,
5320 Defining_Identifier => Derived_Type,
5321 Subtype_Indication =>
5322 Make_Subtype_Indication (Loc,
5323 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
5324 Constraint => Constraint (Indic)));
5326 Rewrite (N, New_Indic);
5331 if Nkind (Indic) /= N_Subtype_Indication then
5334 Set_Ekind (Derived_Type, Ekind (Parent_Type));
5335 Set_Etype (Derived_Type, Implicit_Base);
5336 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
5339 Error_Msg_N ("illegal constraint on constrained type", Indic);
5343 -- If parent type is not a derived type itself, and is declared in
5344 -- closed scope (e.g. a subprogram), then we must explicitly introduce
5345 -- the new type's concatenation operator since Derive_Subprograms
5346 -- will not inherit the parent's operator. If the parent type is
5347 -- unconstrained, the operator is of the unconstrained base type.
5349 if Number_Dimensions (Parent_Type) = 1
5350 and then not Is_Limited_Type (Parent_Type)
5351 and then not Is_Derived_Type (Parent_Type)
5352 and then not Is_Package_Or_Generic_Package
5353 (Scope (Base_Type (Parent_Type)))
5355 if not Is_Constrained (Parent_Type)
5356 and then Is_Constrained (Derived_Type)
5358 New_Concatenation_Op (Implicit_Base);
5360 New_Concatenation_Op (Derived_Type);
5363 end Build_Derived_Array_Type;
5365 -----------------------------------
5366 -- Build_Derived_Concurrent_Type --
5367 -----------------------------------
5369 procedure Build_Derived_Concurrent_Type
5371 Parent_Type : Entity_Id;
5372 Derived_Type : Entity_Id)
5374 Loc : constant Source_Ptr := Sloc (N);
5376 Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C');
5377 Corr_Decl : Node_Id;
5378 Corr_Decl_Needed : Boolean;
5379 -- If the derived type has fewer discriminants than its parent, the
5380 -- corresponding record is also a derived type, in order to account for
5381 -- the bound discriminants. We create a full type declaration for it in
5384 Constraint_Present : constant Boolean :=
5385 Nkind (Subtype_Indication (Type_Definition (N))) =
5386 N_Subtype_Indication;
5388 D_Constraint : Node_Id;
5389 New_Constraint : Elist_Id;
5390 Old_Disc : Entity_Id;
5391 New_Disc : Entity_Id;
5395 Set_Stored_Constraint (Derived_Type, No_Elist);
5396 Corr_Decl_Needed := False;
5399 if Present (Discriminant_Specifications (N))
5400 and then Constraint_Present
5402 Old_Disc := First_Discriminant (Parent_Type);
5403 New_Disc := First (Discriminant_Specifications (N));
5404 while Present (New_Disc) and then Present (Old_Disc) loop
5405 Next_Discriminant (Old_Disc);
5410 if Present (Old_Disc) and then Expander_Active then
5412 -- The new type has fewer discriminants, so we need to create a new
5413 -- corresponding record, which is derived from the corresponding
5414 -- record of the parent, and has a stored constraint that captures
5415 -- the values of the discriminant constraints. The corresponding
5416 -- record is needed only if expander is active and code generation is
5419 -- The type declaration for the derived corresponding record has the
5420 -- same discriminant part and constraints as the current declaration.
5421 -- Copy the unanalyzed tree to build declaration.
5423 Corr_Decl_Needed := True;
5424 New_N := Copy_Separate_Tree (N);
5427 Make_Full_Type_Declaration (Loc,
5428 Defining_Identifier => Corr_Record,
5429 Discriminant_Specifications =>
5430 Discriminant_Specifications (New_N),
5432 Make_Derived_Type_Definition (Loc,
5433 Subtype_Indication =>
5434 Make_Subtype_Indication (Loc,
5437 (Corresponding_Record_Type (Parent_Type), Loc),
5440 (Subtype_Indication (Type_Definition (New_N))))));
5443 -- Copy Storage_Size and Relative_Deadline variables if task case
5445 if Is_Task_Type (Parent_Type) then
5446 Set_Storage_Size_Variable (Derived_Type,
5447 Storage_Size_Variable (Parent_Type));
5448 Set_Relative_Deadline_Variable (Derived_Type,
5449 Relative_Deadline_Variable (Parent_Type));
5452 if Present (Discriminant_Specifications (N)) then
5453 Push_Scope (Derived_Type);
5454 Check_Or_Process_Discriminants (N, Derived_Type);
5456 if Constraint_Present then
5458 Expand_To_Stored_Constraint
5460 Build_Discriminant_Constraints
5462 Subtype_Indication (Type_Definition (N)), True));
5467 elsif Constraint_Present then
5469 -- Build constrained subtype and derive from it
5472 Loc : constant Source_Ptr := Sloc (N);
5473 Anon : constant Entity_Id :=
5474 Make_Defining_Identifier (Loc,
5475 Chars => New_External_Name (Chars (Derived_Type), 'T'));
5480 Make_Subtype_Declaration (Loc,
5481 Defining_Identifier => Anon,
5482 Subtype_Indication =>
5483 Subtype_Indication (Type_Definition (N)));
5484 Insert_Before (N, Decl);
5487 Rewrite (Subtype_Indication (Type_Definition (N)),
5488 New_Occurrence_Of (Anon, Loc));
5489 Set_Analyzed (Derived_Type, False);
5495 -- By default, operations and private data are inherited from parent.
5496 -- However, in the presence of bound discriminants, a new corresponding
5497 -- record will be created, see below.
5499 Set_Has_Discriminants
5500 (Derived_Type, Has_Discriminants (Parent_Type));
5501 Set_Corresponding_Record_Type
5502 (Derived_Type, Corresponding_Record_Type (Parent_Type));
5504 -- Is_Constrained is set according the parent subtype, but is set to
5505 -- False if the derived type is declared with new discriminants.
5509 (Is_Constrained (Parent_Type) or else Constraint_Present)
5510 and then not Present (Discriminant_Specifications (N)));
5512 if Constraint_Present then
5513 if not Has_Discriminants (Parent_Type) then
5514 Error_Msg_N ("untagged parent must have discriminants", N);
5516 elsif Present (Discriminant_Specifications (N)) then
5518 -- Verify that new discriminants are used to constrain old ones
5523 (Constraint (Subtype_Indication (Type_Definition (N)))));
5525 Old_Disc := First_Discriminant (Parent_Type);
5527 while Present (D_Constraint) loop
5528 if Nkind (D_Constraint) /= N_Discriminant_Association then
5530 -- Positional constraint. If it is a reference to a new
5531 -- discriminant, it constrains the corresponding old one.
5533 if Nkind (D_Constraint) = N_Identifier then
5534 New_Disc := First_Discriminant (Derived_Type);
5535 while Present (New_Disc) loop
5536 exit when Chars (New_Disc) = Chars (D_Constraint);
5537 Next_Discriminant (New_Disc);
5540 if Present (New_Disc) then
5541 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
5545 Next_Discriminant (Old_Disc);
5547 -- if this is a named constraint, search by name for the old
5548 -- discriminants constrained by the new one.
5550 elsif Nkind (Expression (D_Constraint)) = N_Identifier then
5552 -- Find new discriminant with that name
5554 New_Disc := First_Discriminant (Derived_Type);
5555 while Present (New_Disc) loop
5557 Chars (New_Disc) = Chars (Expression (D_Constraint));
5558 Next_Discriminant (New_Disc);
5561 if Present (New_Disc) then
5563 -- Verify that new discriminant renames some discriminant
5564 -- of the parent type, and associate the new discriminant
5565 -- with one or more old ones that it renames.
5571 Selector := First (Selector_Names (D_Constraint));
5572 while Present (Selector) loop
5573 Old_Disc := First_Discriminant (Parent_Type);
5574 while Present (Old_Disc) loop
5575 exit when Chars (Old_Disc) = Chars (Selector);
5576 Next_Discriminant (Old_Disc);
5579 if Present (Old_Disc) then
5580 Set_Corresponding_Discriminant
5581 (New_Disc, Old_Disc);
5590 Next (D_Constraint);
5593 New_Disc := First_Discriminant (Derived_Type);
5594 while Present (New_Disc) loop
5595 if No (Corresponding_Discriminant (New_Disc)) then
5597 ("new discriminant& must constrain old one", N, New_Disc);
5600 Subtypes_Statically_Compatible
5602 Etype (Corresponding_Discriminant (New_Disc)))
5605 ("& not statically compatible with parent discriminant",
5609 Next_Discriminant (New_Disc);
5613 elsif Present (Discriminant_Specifications (N)) then
5615 ("missing discriminant constraint in untagged derivation", N);
5618 -- The entity chain of the derived type includes the new discriminants
5619 -- but shares operations with the parent.
5621 if Present (Discriminant_Specifications (N)) then
5622 Old_Disc := First_Discriminant (Parent_Type);
5623 while Present (Old_Disc) loop
5624 if No (Next_Entity (Old_Disc))
5625 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
5628 (Last_Entity (Derived_Type), Next_Entity (Old_Disc));
5632 Next_Discriminant (Old_Disc);
5636 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
5637 if Has_Discriminants (Parent_Type) then
5638 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
5639 Set_Discriminant_Constraint (
5640 Derived_Type, Discriminant_Constraint (Parent_Type));
5644 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
5646 Set_Has_Completion (Derived_Type);
5648 if Corr_Decl_Needed then
5649 Set_Stored_Constraint (Derived_Type, New_Constraint);
5650 Insert_After (N, Corr_Decl);
5651 Analyze (Corr_Decl);
5652 Set_Corresponding_Record_Type (Derived_Type, Corr_Record);
5654 end Build_Derived_Concurrent_Type;
5656 ------------------------------------
5657 -- Build_Derived_Enumeration_Type --
5658 ------------------------------------
5660 procedure Build_Derived_Enumeration_Type
5662 Parent_Type : Entity_Id;
5663 Derived_Type : Entity_Id)
5665 Loc : constant Source_Ptr := Sloc (N);
5666 Def : constant Node_Id := Type_Definition (N);
5667 Indic : constant Node_Id := Subtype_Indication (Def);
5668 Implicit_Base : Entity_Id;
5669 Literal : Entity_Id;
5670 New_Lit : Entity_Id;
5671 Literals_List : List_Id;
5672 Type_Decl : Node_Id;
5674 Rang_Expr : Node_Id;
5677 -- Since types Standard.Character and Standard.[Wide_]Wide_Character do
5678 -- not have explicit literals lists we need to process types derived
5679 -- from them specially. This is handled by Derived_Standard_Character.
5680 -- If the parent type is a generic type, there are no literals either,
5681 -- and we construct the same skeletal representation as for the generic
5684 if Is_Standard_Character_Type (Parent_Type) then
5685 Derived_Standard_Character (N, Parent_Type, Derived_Type);
5687 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
5693 if Nkind (Indic) /= N_Subtype_Indication then
5695 Make_Attribute_Reference (Loc,
5696 Attribute_Name => Name_First,
5697 Prefix => New_Reference_To (Derived_Type, Loc));
5698 Set_Etype (Lo, Derived_Type);
5701 Make_Attribute_Reference (Loc,
5702 Attribute_Name => Name_Last,
5703 Prefix => New_Reference_To (Derived_Type, Loc));
5704 Set_Etype (Hi, Derived_Type);
5706 Set_Scalar_Range (Derived_Type,
5712 -- Analyze subtype indication and verify compatibility
5713 -- with parent type.
5715 if Base_Type (Process_Subtype (Indic, N)) /=
5716 Base_Type (Parent_Type)
5719 ("illegal constraint for formal discrete type", N);
5725 -- If a constraint is present, analyze the bounds to catch
5726 -- premature usage of the derived literals.
5728 if Nkind (Indic) = N_Subtype_Indication
5729 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
5731 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
5732 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
5735 -- Introduce an implicit base type for the derived type even if there
5736 -- is no constraint attached to it, since this seems closer to the
5737 -- Ada semantics. Build a full type declaration tree for the derived
5738 -- type using the implicit base type as the defining identifier. The
5739 -- build a subtype declaration tree which applies the constraint (if
5740 -- any) have it replace the derived type declaration.
5742 Literal := First_Literal (Parent_Type);
5743 Literals_List := New_List;
5744 while Present (Literal)
5745 and then Ekind (Literal) = E_Enumeration_Literal
5747 -- Literals of the derived type have the same representation as
5748 -- those of the parent type, but this representation can be
5749 -- overridden by an explicit representation clause. Indicate
5750 -- that there is no explicit representation given yet. These
5751 -- derived literals are implicit operations of the new type,
5752 -- and can be overridden by explicit ones.
5754 if Nkind (Literal) = N_Defining_Character_Literal then
5756 Make_Defining_Character_Literal (Loc, Chars (Literal));
5758 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
5761 Set_Ekind (New_Lit, E_Enumeration_Literal);
5762 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
5763 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
5764 Set_Enumeration_Rep_Expr (New_Lit, Empty);
5765 Set_Alias (New_Lit, Literal);
5766 Set_Is_Known_Valid (New_Lit, True);
5768 Append (New_Lit, Literals_List);
5769 Next_Literal (Literal);
5773 Make_Defining_Identifier (Sloc (Derived_Type),
5774 Chars => New_External_Name (Chars (Derived_Type), 'B'));
5776 -- Indicate the proper nature of the derived type. This must be done
5777 -- before analysis of the literals, to recognize cases when a literal
5778 -- may be hidden by a previous explicit function definition (cf.
5781 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
5782 Set_Etype (Derived_Type, Implicit_Base);
5785 Make_Full_Type_Declaration (Loc,
5786 Defining_Identifier => Implicit_Base,
5787 Discriminant_Specifications => No_List,
5789 Make_Enumeration_Type_Definition (Loc, Literals_List));
5791 Mark_Rewrite_Insertion (Type_Decl);
5792 Insert_Before (N, Type_Decl);
5793 Analyze (Type_Decl);
5795 -- After the implicit base is analyzed its Etype needs to be changed
5796 -- to reflect the fact that it is derived from the parent type which
5797 -- was ignored during analysis. We also set the size at this point.
5799 Set_Etype (Implicit_Base, Parent_Type);
5801 Set_Size_Info (Implicit_Base, Parent_Type);
5802 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
5803 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
5805 -- Copy other flags from parent type
5807 Set_Has_Non_Standard_Rep
5808 (Implicit_Base, Has_Non_Standard_Rep
5810 Set_Has_Pragma_Ordered
5811 (Implicit_Base, Has_Pragma_Ordered
5813 Set_Has_Delayed_Freeze (Implicit_Base);
5815 -- Process the subtype indication including a validation check on the
5816 -- constraint, if any. If a constraint is given, its bounds must be
5817 -- implicitly converted to the new type.
5819 if Nkind (Indic) = N_Subtype_Indication then
5821 R : constant Node_Id :=
5822 Range_Expression (Constraint (Indic));
5825 if Nkind (R) = N_Range then
5826 Hi := Build_Scalar_Bound
5827 (High_Bound (R), Parent_Type, Implicit_Base);
5828 Lo := Build_Scalar_Bound
5829 (Low_Bound (R), Parent_Type, Implicit_Base);
5832 -- Constraint is a Range attribute. Replace with explicit
5833 -- mention of the bounds of the prefix, which must be a
5836 Analyze (Prefix (R));
5838 Convert_To (Implicit_Base,
5839 Make_Attribute_Reference (Loc,
5840 Attribute_Name => Name_Last,
5842 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
5845 Convert_To (Implicit_Base,
5846 Make_Attribute_Reference (Loc,
5847 Attribute_Name => Name_First,
5849 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
5856 (Type_High_Bound (Parent_Type),
5857 Parent_Type, Implicit_Base);
5860 (Type_Low_Bound (Parent_Type),
5861 Parent_Type, Implicit_Base);
5869 -- If we constructed a default range for the case where no range
5870 -- was given, then the expressions in the range must not freeze
5871 -- since they do not correspond to expressions in the source.
5873 if Nkind (Indic) /= N_Subtype_Indication then
5874 Set_Must_Not_Freeze (Lo);
5875 Set_Must_Not_Freeze (Hi);
5876 Set_Must_Not_Freeze (Rang_Expr);
5880 Make_Subtype_Declaration (Loc,
5881 Defining_Identifier => Derived_Type,
5882 Subtype_Indication =>
5883 Make_Subtype_Indication (Loc,
5884 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
5886 Make_Range_Constraint (Loc,
5887 Range_Expression => Rang_Expr))));
5891 -- If pragma Discard_Names applies on the first subtype of the parent
5892 -- type, then it must be applied on this subtype as well.
5894 if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
5895 Set_Discard_Names (Derived_Type);
5898 -- Apply a range check. Since this range expression doesn't have an
5899 -- Etype, we have to specifically pass the Source_Typ parameter. Is
5902 if Nkind (Indic) = N_Subtype_Indication then
5903 Apply_Range_Check (Range_Expression (Constraint (Indic)),
5905 Source_Typ => Entity (Subtype_Mark (Indic)));
5908 end Build_Derived_Enumeration_Type;
5910 --------------------------------
5911 -- Build_Derived_Numeric_Type --
5912 --------------------------------
5914 procedure Build_Derived_Numeric_Type
5916 Parent_Type : Entity_Id;
5917 Derived_Type : Entity_Id)
5919 Loc : constant Source_Ptr := Sloc (N);
5920 Tdef : constant Node_Id := Type_Definition (N);
5921 Indic : constant Node_Id := Subtype_Indication (Tdef);
5922 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5923 No_Constraint : constant Boolean := Nkind (Indic) /=
5924 N_Subtype_Indication;
5925 Implicit_Base : Entity_Id;
5931 -- Process the subtype indication including a validation check on
5932 -- the constraint if any.
5934 Discard_Node (Process_Subtype (Indic, N));
5936 -- Introduce an implicit base type for the derived type even if there
5937 -- is no constraint attached to it, since this seems closer to the Ada
5941 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
5943 Set_Etype (Implicit_Base, Parent_Base);
5944 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
5945 Set_Size_Info (Implicit_Base, Parent_Base);
5946 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
5947 Set_Parent (Implicit_Base, Parent (Derived_Type));
5948 Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base));
5950 -- Set RM Size for discrete type or decimal fixed-point type
5951 -- Ordinary fixed-point is excluded, why???
5953 if Is_Discrete_Type (Parent_Base)
5954 or else Is_Decimal_Fixed_Point_Type (Parent_Base)
5956 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
5959 Set_Has_Delayed_Freeze (Implicit_Base);
5961 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
5962 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
5964 Set_Scalar_Range (Implicit_Base,
5969 if Has_Infinities (Parent_Base) then
5970 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
5973 -- The Derived_Type, which is the entity of the declaration, is a
5974 -- subtype of the implicit base. Its Ekind is a subtype, even in the
5975 -- absence of an explicit constraint.
5977 Set_Etype (Derived_Type, Implicit_Base);
5979 -- If we did not have a constraint, then the Ekind is set from the
5980 -- parent type (otherwise Process_Subtype has set the bounds)
5982 if No_Constraint then
5983 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
5986 -- If we did not have a range constraint, then set the range from the
5987 -- parent type. Otherwise, the Process_Subtype call has set the bounds.
5990 or else not Has_Range_Constraint (Indic)
5992 Set_Scalar_Range (Derived_Type,
5994 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
5995 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
5996 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
5998 if Has_Infinities (Parent_Type) then
5999 Set_Includes_Infinities (Scalar_Range (Derived_Type));
6002 Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type));
6005 Set_Is_Descendent_Of_Address (Derived_Type,
6006 Is_Descendent_Of_Address (Parent_Type));
6007 Set_Is_Descendent_Of_Address (Implicit_Base,
6008 Is_Descendent_Of_Address (Parent_Type));
6010 -- Set remaining type-specific fields, depending on numeric type
6012 if Is_Modular_Integer_Type (Parent_Type) then
6013 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
6015 Set_Non_Binary_Modulus
6016 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
6019 (Implicit_Base, Is_Known_Valid (Parent_Base));
6021 elsif Is_Floating_Point_Type (Parent_Type) then
6023 -- Digits of base type is always copied from the digits value of
6024 -- the parent base type, but the digits of the derived type will
6025 -- already have been set if there was a constraint present.
6027 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
6028 Set_Float_Rep (Implicit_Base, Float_Rep (Parent_Base));
6030 if No_Constraint then
6031 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
6034 elsif Is_Fixed_Point_Type (Parent_Type) then
6036 -- Small of base type and derived type are always copied from the
6037 -- parent base type, since smalls never change. The delta of the
6038 -- base type is also copied from the parent base type. However the
6039 -- delta of the derived type will have been set already if a
6040 -- constraint was present.
6042 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
6043 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
6044 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
6046 if No_Constraint then
6047 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
6050 -- The scale and machine radix in the decimal case are always
6051 -- copied from the parent base type.
6053 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
6054 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
6055 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
6057 Set_Machine_Radix_10
6058 (Derived_Type, Machine_Radix_10 (Parent_Base));
6059 Set_Machine_Radix_10
6060 (Implicit_Base, Machine_Radix_10 (Parent_Base));
6062 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
6064 if No_Constraint then
6065 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
6068 -- the analysis of the subtype_indication sets the
6069 -- digits value of the derived type.
6076 -- The type of the bounds is that of the parent type, and they
6077 -- must be converted to the derived type.
6079 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
6081 -- The implicit_base should be frozen when the derived type is frozen,
6082 -- but note that it is used in the conversions of the bounds. For fixed
6083 -- types we delay the determination of the bounds until the proper
6084 -- freezing point. For other numeric types this is rejected by GCC, for
6085 -- reasons that are currently unclear (???), so we choose to freeze the
6086 -- implicit base now. In the case of integers and floating point types
6087 -- this is harmless because subsequent representation clauses cannot
6088 -- affect anything, but it is still baffling that we cannot use the
6089 -- same mechanism for all derived numeric types.
6091 -- There is a further complication: actually *some* representation
6092 -- clauses can affect the implicit base type. Namely, attribute
6093 -- definition clauses for stream-oriented attributes need to set the
6094 -- corresponding TSS entries on the base type, and this normally cannot
6095 -- be done after the base type is frozen, so the circuitry in
6096 -- Sem_Ch13.New_Stream_Subprogram must account for this possibility and
6097 -- not use Set_TSS in this case.
6099 if Is_Fixed_Point_Type (Parent_Type) then
6100 Conditional_Delay (Implicit_Base, Parent_Type);
6102 Freeze_Before (N, Implicit_Base);
6104 end Build_Derived_Numeric_Type;
6106 --------------------------------
6107 -- Build_Derived_Private_Type --
6108 --------------------------------
6110 procedure Build_Derived_Private_Type
6112 Parent_Type : Entity_Id;
6113 Derived_Type : Entity_Id;
6114 Is_Completion : Boolean;
6115 Derive_Subps : Boolean := True)
6117 Loc : constant Source_Ptr := Sloc (N);
6118 Der_Base : Entity_Id;
6120 Full_Decl : Node_Id := Empty;
6121 Full_Der : Entity_Id;
6123 Last_Discr : Entity_Id;
6124 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
6125 Swapped : Boolean := False;
6127 procedure Copy_And_Build;
6128 -- Copy derived type declaration, replace parent with its full view,
6129 -- and analyze new declaration.
6131 --------------------
6132 -- Copy_And_Build --
6133 --------------------
6135 procedure Copy_And_Build is
6139 if Ekind (Parent_Type) in Record_Kind
6141 (Ekind (Parent_Type) in Enumeration_Kind
6142 and then not Is_Standard_Character_Type (Parent_Type)
6143 and then not Is_Generic_Type (Root_Type (Parent_Type)))
6145 Full_N := New_Copy_Tree (N);
6146 Insert_After (N, Full_N);
6147 Build_Derived_Type (
6148 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
6151 Build_Derived_Type (
6152 N, Parent_Type, Full_Der, True, Derive_Subps => False);
6156 -- Start of processing for Build_Derived_Private_Type
6159 if Is_Tagged_Type (Parent_Type) then
6160 Full_P := Full_View (Parent_Type);
6162 -- A type extension of a type with unknown discriminants is an
6163 -- indefinite type that the back-end cannot handle directly.
6164 -- We treat it as a private type, and build a completion that is
6165 -- derived from the full view of the parent, and hopefully has
6166 -- known discriminants.
6168 -- If the full view of the parent type has an underlying record view,
6169 -- use it to generate the underlying record view of this derived type
6170 -- (required for chains of derivations with unknown discriminants).
6172 -- Minor optimization: we avoid the generation of useless underlying
6173 -- record view entities if the private type declaration has unknown
6174 -- discriminants but its corresponding full view has no
6177 if Has_Unknown_Discriminants (Parent_Type)
6178 and then Present (Full_P)
6179 and then (Has_Discriminants (Full_P)
6180 or else Present (Underlying_Record_View (Full_P)))
6181 and then not In_Open_Scopes (Par_Scope)
6182 and then Expander_Active
6185 Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T');
6186 New_Ext : constant Node_Id :=
6188 (Record_Extension_Part (Type_Definition (N)));
6192 Build_Derived_Record_Type
6193 (N, Parent_Type, Derived_Type, Derive_Subps);
6195 -- Build anonymous completion, as a derivation from the full
6196 -- view of the parent. This is not a completion in the usual
6197 -- sense, because the current type is not private.
6200 Make_Full_Type_Declaration (Loc,
6201 Defining_Identifier => Full_Der,
6203 Make_Derived_Type_Definition (Loc,
6204 Subtype_Indication =>
6206 (Subtype_Indication (Type_Definition (N))),
6207 Record_Extension_Part => New_Ext));
6209 -- If the parent type has an underlying record view, use it
6210 -- here to build the new underlying record view.
6212 if Present (Underlying_Record_View (Full_P)) then
6214 (Nkind (Subtype_Indication (Type_Definition (Decl)))
6216 Set_Entity (Subtype_Indication (Type_Definition (Decl)),
6217 Underlying_Record_View (Full_P));
6220 Install_Private_Declarations (Par_Scope);
6221 Install_Visible_Declarations (Par_Scope);
6222 Insert_Before (N, Decl);
6224 -- Mark entity as an underlying record view before analysis,
6225 -- to avoid generating the list of its primitive operations
6226 -- (which is not really required for this entity) and thus
6227 -- prevent spurious errors associated with missing overriding
6228 -- of abstract primitives (overridden only for Derived_Type).
6230 Set_Ekind (Full_Der, E_Record_Type);
6231 Set_Is_Underlying_Record_View (Full_Der);
6235 pragma Assert (Has_Discriminants (Full_Der)
6236 and then not Has_Unknown_Discriminants (Full_Der));
6238 Uninstall_Declarations (Par_Scope);
6240 -- Freeze the underlying record view, to prevent generation of
6241 -- useless dispatching information, which is simply shared with
6242 -- the real derived type.
6244 Set_Is_Frozen (Full_Der);
6246 -- Set up links between real entity and underlying record view
6248 Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der));
6249 Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type);
6252 -- If discriminants are known, build derived record
6255 Build_Derived_Record_Type
6256 (N, Parent_Type, Derived_Type, Derive_Subps);
6261 elsif Has_Discriminants (Parent_Type) then
6262 if Present (Full_View (Parent_Type)) then
6263 if not Is_Completion then
6265 -- Copy declaration for subsequent analysis, to provide a
6266 -- completion for what is a private declaration. Indicate that
6267 -- the full type is internally generated.
6269 Full_Decl := New_Copy_Tree (N);
6270 Full_Der := New_Copy (Derived_Type);
6271 Set_Comes_From_Source (Full_Decl, False);
6272 Set_Comes_From_Source (Full_Der, False);
6273 Set_Parent (Full_Der, Full_Decl);
6275 Insert_After (N, Full_Decl);
6278 -- If this is a completion, the full view being built is itself
6279 -- private. We build a subtype of the parent with the same
6280 -- constraints as this full view, to convey to the back end the
6281 -- constrained components and the size of this subtype. If the
6282 -- parent is constrained, its full view can serve as the
6283 -- underlying full view of the derived type.
6285 if No (Discriminant_Specifications (N)) then
6286 if Nkind (Subtype_Indication (Type_Definition (N))) =
6287 N_Subtype_Indication
6289 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
6291 elsif Is_Constrained (Full_View (Parent_Type)) then
6292 Set_Underlying_Full_View
6293 (Derived_Type, Full_View (Parent_Type));
6297 -- If there are new discriminants, the parent subtype is
6298 -- constrained by them, but it is not clear how to build
6299 -- the Underlying_Full_View in this case???
6306 -- Build partial view of derived type from partial view of parent
6308 Build_Derived_Record_Type
6309 (N, Parent_Type, Derived_Type, Derive_Subps);
6311 if Present (Full_View (Parent_Type)) and then not Is_Completion then
6312 if not In_Open_Scopes (Par_Scope)
6313 or else not In_Same_Source_Unit (N, Parent_Type)
6315 -- Swap partial and full views temporarily
6317 Install_Private_Declarations (Par_Scope);
6318 Install_Visible_Declarations (Par_Scope);
6322 -- Build full view of derived type from full view of parent which
6323 -- is now installed. Subprograms have been derived on the partial
6324 -- view, the completion does not derive them anew.
6326 if not Is_Tagged_Type (Parent_Type) then
6328 -- If the parent is itself derived from another private type,
6329 -- installing the private declarations has not affected its
6330 -- privacy status, so use its own full view explicitly.
6332 if Is_Private_Type (Parent_Type) then
6333 Build_Derived_Record_Type
6334 (Full_Decl, Full_View (Parent_Type), Full_Der, False);
6336 Build_Derived_Record_Type
6337 (Full_Decl, Parent_Type, Full_Der, False);
6341 -- If full view of parent is tagged, the completion inherits
6342 -- the proper primitive operations.
6344 Set_Defining_Identifier (Full_Decl, Full_Der);
6345 Build_Derived_Record_Type
6346 (Full_Decl, Parent_Type, Full_Der, Derive_Subps);
6349 -- The full declaration has been introduced into the tree and
6350 -- processed in the step above. It should not be analyzed again
6351 -- (when encountered later in the current list of declarations)
6352 -- to prevent spurious name conflicts. The full entity remains
6355 Set_Analyzed (Full_Decl);
6358 Uninstall_Declarations (Par_Scope);
6360 if In_Open_Scopes (Par_Scope) then
6361 Install_Visible_Declarations (Par_Scope);
6365 Der_Base := Base_Type (Derived_Type);
6366 Set_Full_View (Derived_Type, Full_Der);
6367 Set_Full_View (Der_Base, Base_Type (Full_Der));
6369 -- Copy the discriminant list from full view to the partial views
6370 -- (base type and its subtype). Gigi requires that the partial and
6371 -- full views have the same discriminants.
6373 -- Note that since the partial view is pointing to discriminants
6374 -- in the full view, their scope will be that of the full view.
6375 -- This might cause some front end problems and need adjustment???
6377 Discr := First_Discriminant (Base_Type (Full_Der));
6378 Set_First_Entity (Der_Base, Discr);
6381 Last_Discr := Discr;
6382 Next_Discriminant (Discr);
6383 exit when No (Discr);
6386 Set_Last_Entity (Der_Base, Last_Discr);
6388 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
6389 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
6390 Set_Stored_Constraint (Full_Der, Stored_Constraint (Derived_Type));
6393 -- If this is a completion, the derived type stays private and
6394 -- there is no need to create a further full view, except in the
6395 -- unusual case when the derivation is nested within a child unit,
6401 elsif Present (Full_View (Parent_Type))
6402 and then Has_Discriminants (Full_View (Parent_Type))
6404 if Has_Unknown_Discriminants (Parent_Type)
6405 and then Nkind (Subtype_Indication (Type_Definition (N))) =
6406 N_Subtype_Indication
6409 ("cannot constrain type with unknown discriminants",
6410 Subtype_Indication (Type_Definition (N)));
6414 -- If full view of parent is a record type, build full view as a
6415 -- derivation from the parent's full view. Partial view remains
6416 -- private. For code generation and linking, the full view must have
6417 -- the same public status as the partial one. This full view is only
6418 -- needed if the parent type is in an enclosing scope, so that the
6419 -- full view may actually become visible, e.g. in a child unit. This
6420 -- is both more efficient, and avoids order of freezing problems with
6421 -- the added entities.
6423 if not Is_Private_Type (Full_View (Parent_Type))
6424 and then (In_Open_Scopes (Scope (Parent_Type)))
6427 Make_Defining_Identifier
6428 (Sloc (Derived_Type), Chars (Derived_Type));
6429 Set_Is_Itype (Full_Der);
6430 Set_Has_Private_Declaration (Full_Der);
6431 Set_Has_Private_Declaration (Derived_Type);
6432 Set_Associated_Node_For_Itype (Full_Der, N);
6433 Set_Parent (Full_Der, Parent (Derived_Type));
6434 Set_Full_View (Derived_Type, Full_Der);
6435 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
6436 Full_P := Full_View (Parent_Type);
6437 Exchange_Declarations (Parent_Type);
6439 Exchange_Declarations (Full_P);
6442 Build_Derived_Record_Type
6443 (N, Full_View (Parent_Type), Derived_Type,
6444 Derive_Subps => False);
6447 -- In any case, the primitive operations are inherited from the
6448 -- parent type, not from the internal full view.
6450 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
6452 if Derive_Subps then
6453 Derive_Subprograms (Parent_Type, Derived_Type);
6457 -- Untagged type, No discriminants on either view
6459 if Nkind (Subtype_Indication (Type_Definition (N))) =
6460 N_Subtype_Indication
6463 ("illegal constraint on type without discriminants", N);
6466 if Present (Discriminant_Specifications (N))
6467 and then Present (Full_View (Parent_Type))
6468 and then not Is_Tagged_Type (Full_View (Parent_Type))
6470 Error_Msg_N ("cannot add discriminants to untagged type", N);
6473 Set_Stored_Constraint (Derived_Type, No_Elist);
6474 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
6475 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
6476 Set_Has_Controlled_Component
6477 (Derived_Type, Has_Controlled_Component
6480 -- Direct controlled types do not inherit Finalize_Storage_Only flag
6482 if not Is_Controlled (Parent_Type) then
6483 Set_Finalize_Storage_Only
6484 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
6487 -- Construct the implicit full view by deriving from full view of the
6488 -- parent type. In order to get proper visibility, we install the
6489 -- parent scope and its declarations.
6491 -- ??? If the parent is untagged private and its completion is
6492 -- tagged, this mechanism will not work because we cannot derive from
6493 -- the tagged full view unless we have an extension.
6495 if Present (Full_View (Parent_Type))
6496 and then not Is_Tagged_Type (Full_View (Parent_Type))
6497 and then not Is_Completion
6500 Make_Defining_Identifier
6501 (Sloc (Derived_Type), Chars (Derived_Type));
6502 Set_Is_Itype (Full_Der);
6503 Set_Has_Private_Declaration (Full_Der);
6504 Set_Has_Private_Declaration (Derived_Type);
6505 Set_Associated_Node_For_Itype (Full_Der, N);
6506 Set_Parent (Full_Der, Parent (Derived_Type));
6507 Set_Full_View (Derived_Type, Full_Der);
6509 if not In_Open_Scopes (Par_Scope) then
6510 Install_Private_Declarations (Par_Scope);
6511 Install_Visible_Declarations (Par_Scope);
6513 Uninstall_Declarations (Par_Scope);
6515 -- If parent scope is open and in another unit, and parent has a
6516 -- completion, then the derivation is taking place in the visible
6517 -- part of a child unit. In that case retrieve the full view of
6518 -- the parent momentarily.
6520 elsif not In_Same_Source_Unit (N, Parent_Type) then
6521 Full_P := Full_View (Parent_Type);
6522 Exchange_Declarations (Parent_Type);
6524 Exchange_Declarations (Full_P);
6526 -- Otherwise it is a local derivation
6532 Set_Scope (Full_Der, Current_Scope);
6533 Set_Is_First_Subtype (Full_Der,
6534 Is_First_Subtype (Derived_Type));
6535 Set_Has_Size_Clause (Full_Der, False);
6536 Set_Has_Alignment_Clause (Full_Der, False);
6537 Set_Next_Entity (Full_Der, Empty);
6538 Set_Has_Delayed_Freeze (Full_Der);
6539 Set_Is_Frozen (Full_Der, False);
6540 Set_Freeze_Node (Full_Der, Empty);
6541 Set_Depends_On_Private (Full_Der,
6542 Has_Private_Component (Full_Der));
6543 Set_Public_Status (Full_Der);
6547 Set_Has_Unknown_Discriminants (Derived_Type,
6548 Has_Unknown_Discriminants (Parent_Type));
6550 if Is_Private_Type (Derived_Type) then
6551 Set_Private_Dependents (Derived_Type, New_Elmt_List);
6554 if Is_Private_Type (Parent_Type)
6555 and then Base_Type (Parent_Type) = Parent_Type
6556 and then In_Open_Scopes (Scope (Parent_Type))
6558 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
6560 if Is_Child_Unit (Scope (Current_Scope))
6561 and then Is_Completion
6562 and then In_Private_Part (Current_Scope)
6563 and then Scope (Parent_Type) /= Current_Scope
6565 -- This is the unusual case where a type completed by a private
6566 -- derivation occurs within a package nested in a child unit, and
6567 -- the parent is declared in an ancestor. In this case, the full
6568 -- view of the parent type will become visible in the body of
6569 -- the enclosing child, and only then will the current type be
6570 -- possibly non-private. We build a underlying full view that
6571 -- will be installed when the enclosing child body is compiled.
6574 Make_Defining_Identifier
6575 (Sloc (Derived_Type), Chars (Derived_Type));
6576 Set_Is_Itype (Full_Der);
6577 Build_Itype_Reference (Full_Der, N);
6579 -- The full view will be used to swap entities on entry/exit to
6580 -- the body, and must appear in the entity list for the package.
6582 Append_Entity (Full_Der, Scope (Derived_Type));
6583 Set_Has_Private_Declaration (Full_Der);
6584 Set_Has_Private_Declaration (Derived_Type);
6585 Set_Associated_Node_For_Itype (Full_Der, N);
6586 Set_Parent (Full_Der, Parent (Derived_Type));
6587 Full_P := Full_View (Parent_Type);
6588 Exchange_Declarations (Parent_Type);
6590 Exchange_Declarations (Full_P);
6591 Set_Underlying_Full_View (Derived_Type, Full_Der);
6594 end Build_Derived_Private_Type;
6596 -------------------------------
6597 -- Build_Derived_Record_Type --
6598 -------------------------------
6602 -- Ideally we would like to use the same model of type derivation for
6603 -- tagged and untagged record types. Unfortunately this is not quite
6604 -- possible because the semantics of representation clauses is different
6605 -- for tagged and untagged records under inheritance. Consider the
6608 -- type R (...) is [tagged] record ... end record;
6609 -- type T (...) is new R (...) [with ...];
6611 -- The representation clauses for T can specify a completely different
6612 -- record layout from R's. Hence the same component can be placed in two
6613 -- very different positions in objects of type T and R. If R and T are
6614 -- tagged types, representation clauses for T can only specify the layout
6615 -- of non inherited components, thus components that are common in R and T
6616 -- have the same position in objects of type R and T.
6618 -- This has two implications. The first is that the entire tree for R's
6619 -- declaration needs to be copied for T in the untagged case, so that T
6620 -- can be viewed as a record type of its own with its own representation
6621 -- clauses. The second implication is the way we handle discriminants.
6622 -- Specifically, in the untagged case we need a way to communicate to Gigi
6623 -- what are the real discriminants in the record, while for the semantics
6624 -- we need to consider those introduced by the user to rename the
6625 -- discriminants in the parent type. This is handled by introducing the
6626 -- notion of stored discriminants. See below for more.
6628 -- Fortunately the way regular components are inherited can be handled in
6629 -- the same way in tagged and untagged types.
6631 -- To complicate things a bit more the private view of a private extension
6632 -- cannot be handled in the same way as the full view (for one thing the
6633 -- semantic rules are somewhat different). We will explain what differs
6636 -- 2. DISCRIMINANTS UNDER INHERITANCE
6638 -- The semantic rules governing the discriminants of derived types are
6641 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
6642 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
6644 -- If parent type has discriminants, then the discriminants that are
6645 -- declared in the derived type are [3.4 (11)]:
6647 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
6650 -- o Otherwise, each discriminant of the parent type (implicitly declared
6651 -- in the same order with the same specifications). In this case, the
6652 -- discriminants are said to be "inherited", or if unknown in the parent
6653 -- are also unknown in the derived type.
6655 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
6657 -- o The parent subtype shall be constrained;
6659 -- o If the parent type is not a tagged type, then each discriminant of
6660 -- the derived type shall be used in the constraint defining a parent
6661 -- subtype. [Implementation note: This ensures that the new discriminant
6662 -- can share storage with an existing discriminant.]
6664 -- For the derived type each discriminant of the parent type is either
6665 -- inherited, constrained to equal some new discriminant of the derived
6666 -- type, or constrained to the value of an expression.
6668 -- When inherited or constrained to equal some new discriminant, the
6669 -- parent discriminant and the discriminant of the derived type are said
6672 -- If a discriminant of the parent type is constrained to a specific value
6673 -- in the derived type definition, then the discriminant is said to be
6674 -- "specified" by that derived type definition.
6676 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
6678 -- We have spoken about stored discriminants in point 1 (introduction)
6679 -- above. There are two sort of stored discriminants: implicit and
6680 -- explicit. As long as the derived type inherits the same discriminants as
6681 -- the root record type, stored discriminants are the same as regular
6682 -- discriminants, and are said to be implicit. However, if any discriminant
6683 -- in the root type was renamed in the derived type, then the derived
6684 -- type will contain explicit stored discriminants. Explicit stored
6685 -- discriminants are discriminants in addition to the semantically visible
6686 -- discriminants defined for the derived type. Stored discriminants are
6687 -- used by Gigi to figure out what are the physical discriminants in
6688 -- objects of the derived type (see precise definition in einfo.ads).
6689 -- As an example, consider the following:
6691 -- type R (D1, D2, D3 : Int) is record ... end record;
6692 -- type T1 is new R;
6693 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
6694 -- type T3 is new T2;
6695 -- type T4 (Y : Int) is new T3 (Y, 99);
6697 -- The following table summarizes the discriminants and stored
6698 -- discriminants in R and T1 through T4.
6700 -- Type Discrim Stored Discrim Comment
6701 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
6702 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
6703 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
6704 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
6705 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
6707 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to
6708 -- find the corresponding discriminant in the parent type, while
6709 -- Original_Record_Component (abbreviated ORC below), the actual physical
6710 -- component that is renamed. Finally the field Is_Completely_Hidden
6711 -- (abbreviated ICH below) is set for all explicit stored discriminants
6712 -- (see einfo.ads for more info). For the above example this gives:
6714 -- Discrim CD ORC ICH
6715 -- ^^^^^^^ ^^ ^^^ ^^^
6716 -- D1 in R empty itself no
6717 -- D2 in R empty itself no
6718 -- D3 in R empty itself no
6720 -- D1 in T1 D1 in R itself no
6721 -- D2 in T1 D2 in R itself no
6722 -- D3 in T1 D3 in R itself no
6724 -- X1 in T2 D3 in T1 D3 in T2 no
6725 -- X2 in T2 D1 in T1 D1 in T2 no
6726 -- D1 in T2 empty itself yes
6727 -- D2 in T2 empty itself yes
6728 -- D3 in T2 empty itself yes
6730 -- X1 in T3 X1 in T2 D3 in T3 no
6731 -- X2 in T3 X2 in T2 D1 in T3 no
6732 -- D1 in T3 empty itself yes
6733 -- D2 in T3 empty itself yes
6734 -- D3 in T3 empty itself yes
6736 -- Y in T4 X1 in T3 D3 in T3 no
6737 -- D1 in T3 empty itself yes
6738 -- D2 in T3 empty itself yes
6739 -- D3 in T3 empty itself yes
6741 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
6743 -- Type derivation for tagged types is fairly straightforward. If no
6744 -- discriminants are specified by the derived type, these are inherited
6745 -- from the parent. No explicit stored discriminants are ever necessary.
6746 -- The only manipulation that is done to the tree is that of adding a
6747 -- _parent field with parent type and constrained to the same constraint
6748 -- specified for the parent in the derived type definition. For instance:
6750 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
6751 -- type T1 is new R with null record;
6752 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
6754 -- are changed into:
6756 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
6757 -- _parent : R (D1, D2, D3);
6760 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
6761 -- _parent : T1 (X2, 88, X1);
6764 -- The discriminants actually present in R, T1 and T2 as well as their CD,
6765 -- ORC and ICH fields are:
6767 -- Discrim CD ORC ICH
6768 -- ^^^^^^^ ^^ ^^^ ^^^
6769 -- D1 in R empty itself no
6770 -- D2 in R empty itself no
6771 -- D3 in R empty itself no
6773 -- D1 in T1 D1 in R D1 in R no
6774 -- D2 in T1 D2 in R D2 in R no
6775 -- D3 in T1 D3 in R D3 in R no
6777 -- X1 in T2 D3 in T1 D3 in R no
6778 -- X2 in T2 D1 in T1 D1 in R no
6780 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
6782 -- Regardless of whether we dealing with a tagged or untagged type
6783 -- we will transform all derived type declarations of the form
6785 -- type T is new R (...) [with ...];
6787 -- subtype S is R (...);
6788 -- type T is new S [with ...];
6790 -- type BT is new R [with ...];
6791 -- subtype T is BT (...);
6793 -- That is, the base derived type is constrained only if it has no
6794 -- discriminants. The reason for doing this is that GNAT's semantic model
6795 -- assumes that a base type with discriminants is unconstrained.
6797 -- Note that, strictly speaking, the above transformation is not always
6798 -- correct. Consider for instance the following excerpt from ACVC b34011a:
6800 -- procedure B34011A is
6801 -- type REC (D : integer := 0) is record
6806 -- type T6 is new Rec;
6807 -- function F return T6;
6812 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
6815 -- The definition of Q6.U is illegal. However transforming Q6.U into
6817 -- type BaseU is new T6;
6818 -- subtype U is BaseU (Q6.F.I)
6820 -- turns U into a legal subtype, which is incorrect. To avoid this problem
6821 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
6822 -- the transformation described above.
6824 -- There is another instance where the above transformation is incorrect.
6828 -- type Base (D : Integer) is tagged null record;
6829 -- procedure P (X : Base);
6831 -- type Der is new Base (2) with null record;
6832 -- procedure P (X : Der);
6835 -- Then the above transformation turns this into
6837 -- type Der_Base is new Base with null record;
6838 -- -- procedure P (X : Base) is implicitly inherited here
6839 -- -- as procedure P (X : Der_Base).
6841 -- subtype Der is Der_Base (2);
6842 -- procedure P (X : Der);
6843 -- -- The overriding of P (X : Der_Base) is illegal since we
6844 -- -- have a parameter conformance problem.
6846 -- To get around this problem, after having semantically processed Der_Base
6847 -- and the rewritten subtype declaration for Der, we copy Der_Base field
6848 -- Discriminant_Constraint from Der so that when parameter conformance is
6849 -- checked when P is overridden, no semantic errors are flagged.
6851 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
6853 -- Regardless of whether we are dealing with a tagged or untagged type
6854 -- we will transform all derived type declarations of the form
6856 -- type R (D1, .., Dn : ...) is [tagged] record ...;
6857 -- type T is new R [with ...];
6859 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
6861 -- The reason for such transformation is that it allows us to implement a
6862 -- very clean form of component inheritance as explained below.
6864 -- Note that this transformation is not achieved by direct tree rewriting
6865 -- and manipulation, but rather by redoing the semantic actions that the
6866 -- above transformation will entail. This is done directly in routine
6867 -- Inherit_Components.
6869 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
6871 -- In both tagged and untagged derived types, regular non discriminant
6872 -- components are inherited in the derived type from the parent type. In
6873 -- the absence of discriminants component, inheritance is straightforward
6874 -- as components can simply be copied from the parent.
6876 -- If the parent has discriminants, inheriting components constrained with
6877 -- these discriminants requires caution. Consider the following example:
6879 -- type R (D1, D2 : Positive) is [tagged] record
6880 -- S : String (D1 .. D2);
6883 -- type T1 is new R [with null record];
6884 -- type T2 (X : positive) is new R (1, X) [with null record];
6886 -- As explained in 6. above, T1 is rewritten as
6887 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
6888 -- which makes the treatment for T1 and T2 identical.
6890 -- What we want when inheriting S, is that references to D1 and D2 in R are
6891 -- replaced with references to their correct constraints, i.e. D1 and D2 in
6892 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
6893 -- with either discriminant references in the derived type or expressions.
6894 -- This replacement is achieved as follows: before inheriting R's
6895 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
6896 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
6897 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
6898 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
6899 -- by String (1 .. X).
6901 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
6903 -- We explain here the rules governing private type extensions relevant to
6904 -- type derivation. These rules are explained on the following example:
6906 -- type D [(...)] is new A [(...)] with private; <-- partial view
6907 -- type D [(...)] is new P [(...)] with null record; <-- full view
6909 -- Type A is called the ancestor subtype of the private extension.
6910 -- Type P is the parent type of the full view of the private extension. It
6911 -- must be A or a type derived from A.
6913 -- The rules concerning the discriminants of private type extensions are
6916 -- o If a private extension inherits known discriminants from the ancestor
6917 -- subtype, then the full view shall also inherit its discriminants from
6918 -- the ancestor subtype and the parent subtype of the full view shall be
6919 -- constrained if and only if the ancestor subtype is constrained.
6921 -- o If a partial view has unknown discriminants, then the full view may
6922 -- define a definite or an indefinite subtype, with or without
6925 -- o If a partial view has neither known nor unknown discriminants, then
6926 -- the full view shall define a definite subtype.
6928 -- o If the ancestor subtype of a private extension has constrained
6929 -- discriminants, then the parent subtype of the full view shall impose a
6930 -- statically matching constraint on those discriminants.
6932 -- This means that only the following forms of private extensions are
6935 -- type D is new A with private; <-- partial view
6936 -- type D is new P with null record; <-- full view
6938 -- If A has no discriminants than P has no discriminants, otherwise P must
6939 -- inherit A's discriminants.
6941 -- type D is new A (...) with private; <-- partial view
6942 -- type D is new P (:::) with null record; <-- full view
6944 -- P must inherit A's discriminants and (...) and (:::) must statically
6947 -- subtype A is R (...);
6948 -- type D is new A with private; <-- partial view
6949 -- type D is new P with null record; <-- full view
6951 -- P must have inherited R's discriminants and must be derived from A or
6952 -- any of its subtypes.
6954 -- type D (..) is new A with private; <-- partial view
6955 -- type D (..) is new P [(:::)] with null record; <-- full view
6957 -- No specific constraints on P's discriminants or constraint (:::).
6958 -- Note that A can be unconstrained, but the parent subtype P must either
6959 -- be constrained or (:::) must be present.
6961 -- type D (..) is new A [(...)] with private; <-- partial view
6962 -- type D (..) is new P [(:::)] with null record; <-- full view
6964 -- P's constraints on A's discriminants must statically match those
6965 -- imposed by (...).
6967 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
6969 -- The full view of a private extension is handled exactly as described
6970 -- above. The model chose for the private view of a private extension is
6971 -- the same for what concerns discriminants (i.e. they receive the same
6972 -- treatment as in the tagged case). However, the private view of the
6973 -- private extension always inherits the components of the parent base,
6974 -- without replacing any discriminant reference. Strictly speaking this is
6975 -- incorrect. However, Gigi never uses this view to generate code so this
6976 -- is a purely semantic issue. In theory, a set of transformations similar
6977 -- to those given in 5. and 6. above could be applied to private views of
6978 -- private extensions to have the same model of component inheritance as
6979 -- for non private extensions. However, this is not done because it would
6980 -- further complicate private type processing. Semantically speaking, this
6981 -- leaves us in an uncomfortable situation. As an example consider:
6984 -- type R (D : integer) is tagged record
6985 -- S : String (1 .. D);
6987 -- procedure P (X : R);
6988 -- type T is new R (1) with private;
6990 -- type T is new R (1) with null record;
6993 -- This is transformed into:
6996 -- type R (D : integer) is tagged record
6997 -- S : String (1 .. D);
6999 -- procedure P (X : R);
7000 -- type T is new R (1) with private;
7002 -- type BaseT is new R with null record;
7003 -- subtype T is BaseT (1);
7006 -- (strictly speaking the above is incorrect Ada)
7008 -- From the semantic standpoint the private view of private extension T
7009 -- should be flagged as constrained since one can clearly have
7013 -- in a unit withing Pack. However, when deriving subprograms for the
7014 -- private view of private extension T, T must be seen as unconstrained
7015 -- since T has discriminants (this is a constraint of the current
7016 -- subprogram derivation model). Thus, when processing the private view of
7017 -- a private extension such as T, we first mark T as unconstrained, we
7018 -- process it, we perform program derivation and just before returning from
7019 -- Build_Derived_Record_Type we mark T as constrained.
7021 -- ??? Are there are other uncomfortable cases that we will have to
7024 -- 10. RECORD_TYPE_WITH_PRIVATE complications
7026 -- Types that are derived from a visible record type and have a private
7027 -- extension present other peculiarities. They behave mostly like private
7028 -- types, but if they have primitive operations defined, these will not
7029 -- have the proper signatures for further inheritance, because other
7030 -- primitive operations will use the implicit base that we define for
7031 -- private derivations below. This affect subprogram inheritance (see
7032 -- Derive_Subprograms for details). We also derive the implicit base from
7033 -- the base type of the full view, so that the implicit base is a record
7034 -- type and not another private type, This avoids infinite loops.
7036 procedure Build_Derived_Record_Type
7038 Parent_Type : Entity_Id;
7039 Derived_Type : Entity_Id;
7040 Derive_Subps : Boolean := True)
7042 Discriminant_Specs : constant Boolean :=
7043 Present (Discriminant_Specifications (N));
7044 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
7045 Loc : constant Source_Ptr := Sloc (N);
7046 Private_Extension : constant Boolean :=
7047 Nkind (N) = N_Private_Extension_Declaration;
7048 Assoc_List : Elist_Id;
7049 Constraint_Present : Boolean;
7051 Discrim : Entity_Id;
7053 Inherit_Discrims : Boolean := False;
7054 Last_Discrim : Entity_Id;
7055 New_Base : Entity_Id;
7057 New_Discrs : Elist_Id;
7058 New_Indic : Node_Id;
7059 Parent_Base : Entity_Id;
7060 Save_Etype : Entity_Id;
7061 Save_Discr_Constr : Elist_Id;
7062 Save_Next_Entity : Entity_Id;
7065 Discs : Elist_Id := New_Elmt_List;
7066 -- An empty Discs list means that there were no constraints in the
7067 -- subtype indication or that there was an error processing it.
7070 if Ekind (Parent_Type) = E_Record_Type_With_Private
7071 and then Present (Full_View (Parent_Type))
7072 and then Has_Discriminants (Parent_Type)
7074 Parent_Base := Base_Type (Full_View (Parent_Type));
7076 Parent_Base := Base_Type (Parent_Type);
7079 -- AI05-0115 : if this is a derivation from a private type in some
7080 -- other scope that may lead to invisible components for the derived
7081 -- type, mark it accordingly.
7083 if Is_Private_Type (Parent_Type) then
7084 if Scope (Parent_Type) = Scope (Derived_Type) then
7087 elsif In_Open_Scopes (Scope (Parent_Type))
7088 and then In_Private_Part (Scope (Parent_Type))
7093 Set_Has_Private_Ancestor (Derived_Type);
7097 Set_Has_Private_Ancestor
7098 (Derived_Type, Has_Private_Ancestor (Parent_Type));
7101 -- Before we start the previously documented transformations, here is
7102 -- little fix for size and alignment of tagged types. Normally when we
7103 -- derive type D from type P, we copy the size and alignment of P as the
7104 -- default for D, and in the absence of explicit representation clauses
7105 -- for D, the size and alignment are indeed the same as the parent.
7107 -- But this is wrong for tagged types, since fields may be added, and
7108 -- the default size may need to be larger, and the default alignment may
7109 -- need to be larger.
7111 -- We therefore reset the size and alignment fields in the tagged case.
7112 -- Note that the size and alignment will in any case be at least as
7113 -- large as the parent type (since the derived type has a copy of the
7114 -- parent type in the _parent field)
7116 -- The type is also marked as being tagged here, which is needed when
7117 -- processing components with a self-referential anonymous access type
7118 -- in the call to Check_Anonymous_Access_Components below. Note that
7119 -- this flag is also set later on for completeness.
7122 Set_Is_Tagged_Type (Derived_Type);
7123 Init_Size_Align (Derived_Type);
7126 -- STEP 0a: figure out what kind of derived type declaration we have
7128 if Private_Extension then
7130 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
7133 Type_Def := Type_Definition (N);
7135 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
7136 -- Parent_Base can be a private type or private extension. However,
7137 -- for tagged types with an extension the newly added fields are
7138 -- visible and hence the Derived_Type is always an E_Record_Type.
7139 -- (except that the parent may have its own private fields).
7140 -- For untagged types we preserve the Ekind of the Parent_Base.
7142 if Present (Record_Extension_Part (Type_Def)) then
7143 Set_Ekind (Derived_Type, E_Record_Type);
7145 -- Create internal access types for components with anonymous
7148 if Ada_Version >= Ada_2005 then
7149 Check_Anonymous_Access_Components
7150 (N, Derived_Type, Derived_Type,
7151 Component_List (Record_Extension_Part (Type_Def)));
7155 Set_Ekind (Derived_Type, Ekind (Parent_Base));
7159 -- Indic can either be an N_Identifier if the subtype indication
7160 -- contains no constraint or an N_Subtype_Indication if the subtype
7161 -- indication has a constraint.
7163 Indic := Subtype_Indication (Type_Def);
7164 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
7166 -- Check that the type has visible discriminants. The type may be
7167 -- a private type with unknown discriminants whose full view has
7168 -- discriminants which are invisible.
7170 if Constraint_Present then
7171 if not Has_Discriminants (Parent_Base)
7173 (Has_Unknown_Discriminants (Parent_Base)
7174 and then Is_Private_Type (Parent_Base))
7177 ("invalid constraint: type has no discriminant",
7178 Constraint (Indic));
7180 Constraint_Present := False;
7181 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
7183 elsif Is_Constrained (Parent_Type) then
7185 ("invalid constraint: parent type is already constrained",
7186 Constraint (Indic));
7188 Constraint_Present := False;
7189 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
7193 -- STEP 0b: If needed, apply transformation given in point 5. above
7195 if not Private_Extension
7196 and then Has_Discriminants (Parent_Type)
7197 and then not Discriminant_Specs
7198 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
7200 -- First, we must analyze the constraint (see comment in point 5.)
7202 if Constraint_Present then
7203 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
7205 if Has_Discriminants (Derived_Type)
7206 and then Has_Private_Declaration (Derived_Type)
7207 and then Present (Discriminant_Constraint (Derived_Type))
7209 -- Verify that constraints of the full view statically match
7210 -- those given in the partial view.
7216 C1 := First_Elmt (New_Discrs);
7217 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
7218 while Present (C1) and then Present (C2) loop
7219 if Fully_Conformant_Expressions (Node (C1), Node (C2))
7221 (Is_OK_Static_Expression (Node (C1))
7223 Is_OK_Static_Expression (Node (C2))
7225 Expr_Value (Node (C1)) = Expr_Value (Node (C2)))
7231 "constraint not conformant to previous declaration",
7242 -- Insert and analyze the declaration for the unconstrained base type
7244 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
7247 Make_Full_Type_Declaration (Loc,
7248 Defining_Identifier => New_Base,
7250 Make_Derived_Type_Definition (Loc,
7251 Abstract_Present => Abstract_Present (Type_Def),
7252 Limited_Present => Limited_Present (Type_Def),
7253 Subtype_Indication =>
7254 New_Occurrence_Of (Parent_Base, Loc),
7255 Record_Extension_Part =>
7256 Relocate_Node (Record_Extension_Part (Type_Def)),
7257 Interface_List => Interface_List (Type_Def)));
7259 Set_Parent (New_Decl, Parent (N));
7260 Mark_Rewrite_Insertion (New_Decl);
7261 Insert_Before (N, New_Decl);
7263 -- In the extension case, make sure ancestor is frozen appropriately
7264 -- (see also non-discriminated case below).
7266 if Present (Record_Extension_Part (Type_Def))
7267 or else Is_Interface (Parent_Base)
7269 Freeze_Before (New_Decl, Parent_Type);
7272 -- Note that this call passes False for the Derive_Subps parameter
7273 -- because subprogram derivation is deferred until after creating
7274 -- the subtype (see below).
7277 (New_Decl, Parent_Base, New_Base,
7278 Is_Completion => True, Derive_Subps => False);
7280 -- ??? This needs re-examination to determine whether the
7281 -- above call can simply be replaced by a call to Analyze.
7283 Set_Analyzed (New_Decl);
7285 -- Insert and analyze the declaration for the constrained subtype
7287 if Constraint_Present then
7289 Make_Subtype_Indication (Loc,
7290 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
7291 Constraint => Relocate_Node (Constraint (Indic)));
7295 Constr_List : constant List_Id := New_List;
7300 C := First_Elmt (Discriminant_Constraint (Parent_Type));
7301 while Present (C) loop
7304 -- It is safe here to call New_Copy_Tree since
7305 -- Force_Evaluation was called on each constraint in
7306 -- Build_Discriminant_Constraints.
7308 Append (New_Copy_Tree (Expr), To => Constr_List);
7314 Make_Subtype_Indication (Loc,
7315 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
7317 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
7322 Make_Subtype_Declaration (Loc,
7323 Defining_Identifier => Derived_Type,
7324 Subtype_Indication => New_Indic));
7328 -- Derivation of subprograms must be delayed until the full subtype
7329 -- has been established, to ensure proper overriding of subprograms
7330 -- inherited by full types. If the derivations occurred as part of
7331 -- the call to Build_Derived_Type above, then the check for type
7332 -- conformance would fail because earlier primitive subprograms
7333 -- could still refer to the full type prior the change to the new
7334 -- subtype and hence would not match the new base type created here.
7335 -- Subprograms are not derived, however, when Derive_Subps is False
7336 -- (since otherwise there could be redundant derivations).
7338 if Derive_Subps then
7339 Derive_Subprograms (Parent_Type, Derived_Type);
7342 -- For tagged types the Discriminant_Constraint of the new base itype
7343 -- is inherited from the first subtype so that no subtype conformance
7344 -- problem arise when the first subtype overrides primitive
7345 -- operations inherited by the implicit base type.
7348 Set_Discriminant_Constraint
7349 (New_Base, Discriminant_Constraint (Derived_Type));
7355 -- If we get here Derived_Type will have no discriminants or it will be
7356 -- a discriminated unconstrained base type.
7358 -- STEP 1a: perform preliminary actions/checks for derived tagged types
7362 -- The parent type is frozen for non-private extensions (RM 13.14(7))
7363 -- The declaration of a specific descendant of an interface type
7364 -- freezes the interface type (RM 13.14).
7366 if not Private_Extension or else Is_Interface (Parent_Base) then
7367 Freeze_Before (N, Parent_Type);
7370 -- In Ada 2005 (AI-344), the restriction that a derived tagged type
7371 -- cannot be declared at a deeper level than its parent type is
7372 -- removed. The check on derivation within a generic body is also
7373 -- relaxed, but there's a restriction that a derived tagged type
7374 -- cannot be declared in a generic body if it's derived directly
7375 -- or indirectly from a formal type of that generic.
7377 if Ada_Version >= Ada_2005 then
7378 if Present (Enclosing_Generic_Body (Derived_Type)) then
7380 Ancestor_Type : Entity_Id;
7383 -- Check to see if any ancestor of the derived type is a
7386 Ancestor_Type := Parent_Type;
7387 while not Is_Generic_Type (Ancestor_Type)
7388 and then Etype (Ancestor_Type) /= Ancestor_Type
7390 Ancestor_Type := Etype (Ancestor_Type);
7393 -- If the derived type does have a formal type as an
7394 -- ancestor, then it's an error if the derived type is
7395 -- declared within the body of the generic unit that
7396 -- declares the formal type in its generic formal part. It's
7397 -- sufficient to check whether the ancestor type is declared
7398 -- inside the same generic body as the derived type (such as
7399 -- within a nested generic spec), in which case the
7400 -- derivation is legal. If the formal type is declared
7401 -- outside of that generic body, then it's guaranteed that
7402 -- the derived type is declared within the generic body of
7403 -- the generic unit declaring the formal type.
7405 if Is_Generic_Type (Ancestor_Type)
7406 and then Enclosing_Generic_Body (Ancestor_Type) /=
7407 Enclosing_Generic_Body (Derived_Type)
7410 ("parent type of& must not be descendant of formal type"
7411 & " of an enclosing generic body",
7412 Indic, Derived_Type);
7417 elsif Type_Access_Level (Derived_Type) /=
7418 Type_Access_Level (Parent_Type)
7419 and then not Is_Generic_Type (Derived_Type)
7421 if Is_Controlled (Parent_Type) then
7423 ("controlled type must be declared at the library level",
7427 ("type extension at deeper accessibility level than parent",
7433 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
7437 and then GB /= Enclosing_Generic_Body (Parent_Base)
7440 ("parent type of& must not be outside generic body"
7442 Indic, Derived_Type);
7448 -- Ada 2005 (AI-251)
7450 if Ada_Version >= Ada_2005 and then Is_Tagged then
7452 -- "The declaration of a specific descendant of an interface type
7453 -- freezes the interface type" (RM 13.14).
7458 if Is_Non_Empty_List (Interface_List (Type_Def)) then
7459 Iface := First (Interface_List (Type_Def));
7460 while Present (Iface) loop
7461 Freeze_Before (N, Etype (Iface));
7468 -- STEP 1b : preliminary cleanup of the full view of private types
7470 -- If the type is already marked as having discriminants, then it's the
7471 -- completion of a private type or private extension and we need to
7472 -- retain the discriminants from the partial view if the current
7473 -- declaration has Discriminant_Specifications so that we can verify
7474 -- conformance. However, we must remove any existing components that
7475 -- were inherited from the parent (and attached in Copy_And_Swap)
7476 -- because the full type inherits all appropriate components anyway, and
7477 -- we do not want the partial view's components interfering.
7479 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
7480 Discrim := First_Discriminant (Derived_Type);
7482 Last_Discrim := Discrim;
7483 Next_Discriminant (Discrim);
7484 exit when No (Discrim);
7487 Set_Last_Entity (Derived_Type, Last_Discrim);
7489 -- In all other cases wipe out the list of inherited components (even
7490 -- inherited discriminants), it will be properly rebuilt here.
7493 Set_First_Entity (Derived_Type, Empty);
7494 Set_Last_Entity (Derived_Type, Empty);
7497 -- STEP 1c: Initialize some flags for the Derived_Type
7499 -- The following flags must be initialized here so that
7500 -- Process_Discriminants can check that discriminants of tagged types do
7501 -- not have a default initial value and that access discriminants are
7502 -- only specified for limited records. For completeness, these flags are
7503 -- also initialized along with all the other flags below.
7505 -- AI-419: Limitedness is not inherited from an interface parent, so to
7506 -- be limited in that case the type must be explicitly declared as
7507 -- limited. However, task and protected interfaces are always limited.
7509 if Limited_Present (Type_Def) then
7510 Set_Is_Limited_Record (Derived_Type);
7512 elsif Is_Limited_Record (Parent_Type)
7513 or else (Present (Full_View (Parent_Type))
7514 and then Is_Limited_Record (Full_View (Parent_Type)))
7516 if not Is_Interface (Parent_Type)
7517 or else Is_Synchronized_Interface (Parent_Type)
7518 or else Is_Protected_Interface (Parent_Type)
7519 or else Is_Task_Interface (Parent_Type)
7521 Set_Is_Limited_Record (Derived_Type);
7525 -- STEP 2a: process discriminants of derived type if any
7527 Push_Scope (Derived_Type);
7529 if Discriminant_Specs then
7530 Set_Has_Unknown_Discriminants (Derived_Type, False);
7532 -- The following call initializes fields Has_Discriminants and
7533 -- Discriminant_Constraint, unless we are processing the completion
7534 -- of a private type declaration.
7536 Check_Or_Process_Discriminants (N, Derived_Type);
7538 -- For untagged types, the constraint on the Parent_Type must be
7539 -- present and is used to rename the discriminants.
7541 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
7542 Error_Msg_N ("untagged parent must have discriminants", Indic);
7544 elsif not Is_Tagged and then not Constraint_Present then
7546 ("discriminant constraint needed for derived untagged records",
7549 -- Otherwise the parent subtype must be constrained unless we have a
7550 -- private extension.
7552 elsif not Constraint_Present
7553 and then not Private_Extension
7554 and then not Is_Constrained (Parent_Type)
7557 ("unconstrained type not allowed in this context", Indic);
7559 elsif Constraint_Present then
7560 -- The following call sets the field Corresponding_Discriminant
7561 -- for the discriminants in the Derived_Type.
7563 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
7565 -- For untagged types all new discriminants must rename
7566 -- discriminants in the parent. For private extensions new
7567 -- discriminants cannot rename old ones (implied by [7.3(13)]).
7569 Discrim := First_Discriminant (Derived_Type);
7570 while Present (Discrim) loop
7572 and then No (Corresponding_Discriminant (Discrim))
7575 ("new discriminants must constrain old ones", Discrim);
7577 elsif Private_Extension
7578 and then Present (Corresponding_Discriminant (Discrim))
7581 ("only static constraints allowed for parent"
7582 & " discriminants in the partial view", Indic);
7586 -- If a new discriminant is used in the constraint, then its
7587 -- subtype must be statically compatible with the parent
7588 -- discriminant's subtype (3.7(15)).
7590 if Present (Corresponding_Discriminant (Discrim))
7592 not Subtypes_Statically_Compatible
7594 Etype (Corresponding_Discriminant (Discrim)))
7597 ("subtype must be compatible with parent discriminant",
7601 Next_Discriminant (Discrim);
7604 -- Check whether the constraints of the full view statically
7605 -- match those imposed by the parent subtype [7.3(13)].
7607 if Present (Stored_Constraint (Derived_Type)) then
7612 C1 := First_Elmt (Discs);
7613 C2 := First_Elmt (Stored_Constraint (Derived_Type));
7614 while Present (C1) and then Present (C2) loop
7616 Fully_Conformant_Expressions (Node (C1), Node (C2))
7619 ("not conformant with previous declaration",
7630 -- STEP 2b: No new discriminants, inherit discriminants if any
7633 if Private_Extension then
7634 Set_Has_Unknown_Discriminants
7636 Has_Unknown_Discriminants (Parent_Type)
7637 or else Unknown_Discriminants_Present (N));
7639 -- The partial view of the parent may have unknown discriminants,
7640 -- but if the full view has discriminants and the parent type is
7641 -- in scope they must be inherited.
7643 elsif Has_Unknown_Discriminants (Parent_Type)
7645 (not Has_Discriminants (Parent_Type)
7646 or else not In_Open_Scopes (Scope (Parent_Type)))
7648 Set_Has_Unknown_Discriminants (Derived_Type);
7651 if not Has_Unknown_Discriminants (Derived_Type)
7652 and then not Has_Unknown_Discriminants (Parent_Base)
7653 and then Has_Discriminants (Parent_Type)
7655 Inherit_Discrims := True;
7656 Set_Has_Discriminants
7657 (Derived_Type, True);
7658 Set_Discriminant_Constraint
7659 (Derived_Type, Discriminant_Constraint (Parent_Base));
7662 -- The following test is true for private types (remember
7663 -- transformation 5. is not applied to those) and in an error
7666 if Constraint_Present then
7667 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
7670 -- For now mark a new derived type as constrained only if it has no
7671 -- discriminants. At the end of Build_Derived_Record_Type we properly
7672 -- set this flag in the case of private extensions. See comments in
7673 -- point 9. just before body of Build_Derived_Record_Type.
7677 not (Inherit_Discrims
7678 or else Has_Unknown_Discriminants (Derived_Type)));
7681 -- STEP 3: initialize fields of derived type
7683 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
7684 Set_Stored_Constraint (Derived_Type, No_Elist);
7686 -- Ada 2005 (AI-251): Private type-declarations can implement interfaces
7687 -- but cannot be interfaces
7689 if not Private_Extension
7690 and then Ekind (Derived_Type) /= E_Private_Type
7691 and then Ekind (Derived_Type) /= E_Limited_Private_Type
7693 if Interface_Present (Type_Def) then
7694 Analyze_Interface_Declaration (Derived_Type, Type_Def);
7697 Set_Interfaces (Derived_Type, No_Elist);
7700 -- Fields inherited from the Parent_Type
7703 (Derived_Type, Einfo.Discard_Names (Parent_Type));
7704 Set_Has_Specified_Layout
7705 (Derived_Type, Has_Specified_Layout (Parent_Type));
7706 Set_Is_Limited_Composite
7707 (Derived_Type, Is_Limited_Composite (Parent_Type));
7708 Set_Is_Private_Composite
7709 (Derived_Type, Is_Private_Composite (Parent_Type));
7711 -- Fields inherited from the Parent_Base
7713 Set_Has_Controlled_Component
7714 (Derived_Type, Has_Controlled_Component (Parent_Base));
7715 Set_Has_Non_Standard_Rep
7716 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
7717 Set_Has_Primitive_Operations
7718 (Derived_Type, Has_Primitive_Operations (Parent_Base));
7720 -- Fields inherited from the Parent_Base in the non-private case
7722 if Ekind (Derived_Type) = E_Record_Type then
7723 Set_Has_Complex_Representation
7724 (Derived_Type, Has_Complex_Representation (Parent_Base));
7727 -- Fields inherited from the Parent_Base for record types
7729 if Is_Record_Type (Derived_Type) then
7731 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
7732 -- Parent_Base can be a private type or private extension.
7734 if Present (Full_View (Parent_Base)) then
7735 Set_OK_To_Reorder_Components
7737 OK_To_Reorder_Components (Full_View (Parent_Base)));
7738 Set_Reverse_Bit_Order
7739 (Derived_Type, Reverse_Bit_Order (Full_View (Parent_Base)));
7741 Set_OK_To_Reorder_Components
7742 (Derived_Type, OK_To_Reorder_Components (Parent_Base));
7743 Set_Reverse_Bit_Order
7744 (Derived_Type, Reverse_Bit_Order (Parent_Base));
7748 -- Direct controlled types do not inherit Finalize_Storage_Only flag
7750 if not Is_Controlled (Parent_Type) then
7751 Set_Finalize_Storage_Only
7752 (Derived_Type, Finalize_Storage_Only (Parent_Type));
7755 -- Set fields for private derived types
7757 if Is_Private_Type (Derived_Type) then
7758 Set_Depends_On_Private (Derived_Type, True);
7759 Set_Private_Dependents (Derived_Type, New_Elmt_List);
7761 -- Inherit fields from non private record types. If this is the
7762 -- completion of a derivation from a private type, the parent itself
7763 -- is private, and the attributes come from its full view, which must
7767 if Is_Private_Type (Parent_Base)
7768 and then not Is_Record_Type (Parent_Base)
7770 Set_Component_Alignment
7771 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
7773 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
7775 Set_Component_Alignment
7776 (Derived_Type, Component_Alignment (Parent_Base));
7778 (Derived_Type, C_Pass_By_Copy (Parent_Base));
7782 -- Set fields for tagged types
7785 Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
7787 -- All tagged types defined in Ada.Finalization are controlled
7789 if Chars (Scope (Derived_Type)) = Name_Finalization
7790 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
7791 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
7793 Set_Is_Controlled (Derived_Type);
7795 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
7798 -- Minor optimization: there is no need to generate the class-wide
7799 -- entity associated with an underlying record view.
7801 if not Is_Underlying_Record_View (Derived_Type) then
7802 Make_Class_Wide_Type (Derived_Type);
7805 Set_Is_Abstract_Type (Derived_Type, Abstract_Present (Type_Def));
7807 if Has_Discriminants (Derived_Type)
7808 and then Constraint_Present
7810 Set_Stored_Constraint
7811 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
7814 if Ada_Version >= Ada_2005 then
7816 Ifaces_List : Elist_Id;
7819 -- Checks rules 3.9.4 (13/2 and 14/2)
7821 if Comes_From_Source (Derived_Type)
7822 and then not Is_Private_Type (Derived_Type)
7823 and then Is_Interface (Parent_Type)
7824 and then not Is_Interface (Derived_Type)
7826 if Is_Task_Interface (Parent_Type) then
7828 ("(Ada 2005) task type required (RM 3.9.4 (13.2))",
7831 elsif Is_Protected_Interface (Parent_Type) then
7833 ("(Ada 2005) protected type required (RM 3.9.4 (14.2))",
7838 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
7840 Check_Interfaces (N, Type_Def);
7842 -- Ada 2005 (AI-251): Collect the list of progenitors that are
7843 -- not already in the parents.
7847 Ifaces_List => Ifaces_List,
7848 Exclude_Parents => True);
7850 Set_Interfaces (Derived_Type, Ifaces_List);
7852 -- If the derived type is the anonymous type created for
7853 -- a declaration whose parent has a constraint, propagate
7854 -- the interface list to the source type. This must be done
7855 -- prior to the completion of the analysis of the source type
7856 -- because the components in the extension may contain current
7857 -- instances whose legality depends on some ancestor.
7859 if Is_Itype (Derived_Type) then
7861 Def : constant Node_Id :=
7862 Associated_Node_For_Itype (Derived_Type);
7865 and then Nkind (Def) = N_Full_Type_Declaration
7868 (Defining_Identifier (Def), Ifaces_List);
7876 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
7877 Set_Has_Non_Standard_Rep
7878 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
7881 -- STEP 4: Inherit components from the parent base and constrain them.
7882 -- Apply the second transformation described in point 6. above.
7884 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
7885 or else not Has_Discriminants (Parent_Type)
7886 or else not Is_Constrained (Parent_Type)
7890 Constrs := Discriminant_Constraint (Parent_Type);
7895 (N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
7897 -- STEP 5a: Copy the parent record declaration for untagged types
7899 if not Is_Tagged then
7901 -- Discriminant_Constraint (Derived_Type) has been properly
7902 -- constructed. Save it and temporarily set it to Empty because we
7903 -- do not want the call to New_Copy_Tree below to mess this list.
7905 if Has_Discriminants (Derived_Type) then
7906 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
7907 Set_Discriminant_Constraint (Derived_Type, No_Elist);
7909 Save_Discr_Constr := No_Elist;
7912 -- Save the Etype field of Derived_Type. It is correctly set now,
7913 -- but the call to New_Copy tree may remap it to point to itself,
7914 -- which is not what we want. Ditto for the Next_Entity field.
7916 Save_Etype := Etype (Derived_Type);
7917 Save_Next_Entity := Next_Entity (Derived_Type);
7919 -- Assoc_List maps all stored discriminants in the Parent_Base to
7920 -- stored discriminants in the Derived_Type. It is fundamental that
7921 -- no types or itypes with discriminants other than the stored
7922 -- discriminants appear in the entities declared inside
7923 -- Derived_Type, since the back end cannot deal with it.
7927 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
7929 -- Restore the fields saved prior to the New_Copy_Tree call
7930 -- and compute the stored constraint.
7932 Set_Etype (Derived_Type, Save_Etype);
7933 Set_Next_Entity (Derived_Type, Save_Next_Entity);
7935 if Has_Discriminants (Derived_Type) then
7936 Set_Discriminant_Constraint
7937 (Derived_Type, Save_Discr_Constr);
7938 Set_Stored_Constraint
7939 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
7940 Replace_Components (Derived_Type, New_Decl);
7941 Set_Has_Implicit_Dereference
7942 (Derived_Type, Has_Implicit_Dereference (Parent_Type));
7945 -- Insert the new derived type declaration
7947 Rewrite (N, New_Decl);
7949 -- STEP 5b: Complete the processing for record extensions in generics
7951 -- There is no completion for record extensions declared in the
7952 -- parameter part of a generic, so we need to complete processing for
7953 -- these generic record extensions here. The Record_Type_Definition call
7954 -- will change the Ekind of the components from E_Void to E_Component.
7956 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
7957 Record_Type_Definition (Empty, Derived_Type);
7959 -- STEP 5c: Process the record extension for non private tagged types
7961 elsif not Private_Extension then
7963 -- Add the _parent field in the derived type
7965 Expand_Record_Extension (Derived_Type, Type_Def);
7967 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
7968 -- implemented interfaces if we are in expansion mode
7971 and then Has_Interfaces (Derived_Type)
7973 Add_Interface_Tag_Components (N, Derived_Type);
7976 -- Analyze the record extension
7978 Record_Type_Definition
7979 (Record_Extension_Part (Type_Def), Derived_Type);
7984 -- Nothing else to do if there is an error in the derivation.
7985 -- An unusual case: the full view may be derived from a type in an
7986 -- instance, when the partial view was used illegally as an actual
7987 -- in that instance, leading to a circular definition.
7989 if Etype (Derived_Type) = Any_Type
7990 or else Etype (Parent_Type) = Derived_Type
7995 -- Set delayed freeze and then derive subprograms, we need to do
7996 -- this in this order so that derived subprograms inherit the
7997 -- derived freeze if necessary.
7999 Set_Has_Delayed_Freeze (Derived_Type);
8001 if Derive_Subps then
8002 Derive_Subprograms (Parent_Type, Derived_Type);
8005 -- If we have a private extension which defines a constrained derived
8006 -- type mark as constrained here after we have derived subprograms. See
8007 -- comment on point 9. just above the body of Build_Derived_Record_Type.
8009 if Private_Extension and then Inherit_Discrims then
8010 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
8011 Set_Is_Constrained (Derived_Type, True);
8012 Set_Discriminant_Constraint (Derived_Type, Discs);
8014 elsif Is_Constrained (Parent_Type) then
8016 (Derived_Type, True);
8017 Set_Discriminant_Constraint
8018 (Derived_Type, Discriminant_Constraint (Parent_Type));
8022 -- Update the class-wide type, which shares the now-completed entity
8023 -- list with its specific type. In case of underlying record views,
8024 -- we do not generate the corresponding class wide entity.
8027 and then not Is_Underlying_Record_View (Derived_Type)
8030 (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
8032 (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
8034 end Build_Derived_Record_Type;
8036 ------------------------
8037 -- Build_Derived_Type --
8038 ------------------------
8040 procedure Build_Derived_Type
8042 Parent_Type : Entity_Id;
8043 Derived_Type : Entity_Id;
8044 Is_Completion : Boolean;
8045 Derive_Subps : Boolean := True)
8047 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8050 -- Set common attributes
8052 Set_Scope (Derived_Type, Current_Scope);
8054 Set_Ekind (Derived_Type, Ekind (Parent_Base));
8055 Set_Etype (Derived_Type, Parent_Base);
8056 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
8058 Set_Size_Info (Derived_Type, Parent_Type);
8059 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8060 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
8061 Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type));
8063 -- If the parent type is a private subtype, the convention on the base
8064 -- type may be set in the private part, and not propagated to the
8065 -- subtype until later, so we obtain the convention from the base type.
8067 Set_Convention (Derived_Type, Convention (Parent_Base));
8069 -- Propagate invariant information. The new type has invariants if
8070 -- they are inherited from the parent type, and these invariants can
8071 -- be further inherited, so both flags are set.
8073 if Has_Inheritable_Invariants (Parent_Type) then
8074 Set_Has_Inheritable_Invariants (Derived_Type);
8075 Set_Has_Invariants (Derived_Type);
8078 -- We similarly inherit predicates
8080 if Has_Predicates (Parent_Type) then
8081 Set_Has_Predicates (Derived_Type);
8084 -- The derived type inherits the representation clauses of the parent.
8085 -- However, for a private type that is completed by a derivation, there
8086 -- may be operation attributes that have been specified already (stream
8087 -- attributes and External_Tag) and those must be provided. Finally,
8088 -- if the partial view is a private extension, the representation items
8089 -- of the parent have been inherited already, and should not be chained
8090 -- twice to the derived type.
8092 if Is_Tagged_Type (Parent_Type)
8093 and then Present (First_Rep_Item (Derived_Type))
8095 -- The existing items are either operational items or items inherited
8096 -- from a private extension declaration.
8100 -- Used to iterate over representation items of the derived type
8103 -- Last representation item of the (non-empty) representation
8104 -- item list of the derived type.
8106 Found : Boolean := False;
8109 Rep := First_Rep_Item (Derived_Type);
8111 while Present (Rep) loop
8112 if Rep = First_Rep_Item (Parent_Type) then
8117 Rep := Next_Rep_Item (Rep);
8119 if Present (Rep) then
8125 -- Here if we either encountered the parent type's first rep
8126 -- item on the derived type's rep item list (in which case
8127 -- Found is True, and we have nothing else to do), or if we
8128 -- reached the last rep item of the derived type, which is
8129 -- Last_Rep, in which case we further chain the parent type's
8130 -- rep items to those of the derived type.
8133 Set_Next_Rep_Item (Last_Rep, First_Rep_Item (Parent_Type));
8138 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
8141 case Ekind (Parent_Type) is
8142 when Numeric_Kind =>
8143 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
8146 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
8150 | Class_Wide_Kind =>
8151 Build_Derived_Record_Type
8152 (N, Parent_Type, Derived_Type, Derive_Subps);
8155 when Enumeration_Kind =>
8156 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
8159 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
8161 when Incomplete_Or_Private_Kind =>
8162 Build_Derived_Private_Type
8163 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
8165 -- For discriminated types, the derivation includes deriving
8166 -- primitive operations. For others it is done below.
8168 if Is_Tagged_Type (Parent_Type)
8169 or else Has_Discriminants (Parent_Type)
8170 or else (Present (Full_View (Parent_Type))
8171 and then Has_Discriminants (Full_View (Parent_Type)))
8176 when Concurrent_Kind =>
8177 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
8180 raise Program_Error;
8183 if Etype (Derived_Type) = Any_Type then
8187 -- Set delayed freeze and then derive subprograms, we need to do this
8188 -- in this order so that derived subprograms inherit the derived freeze
8191 Set_Has_Delayed_Freeze (Derived_Type);
8192 if Derive_Subps then
8193 Derive_Subprograms (Parent_Type, Derived_Type);
8196 Set_Has_Primitive_Operations
8197 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
8198 end Build_Derived_Type;
8200 -----------------------
8201 -- Build_Discriminal --
8202 -----------------------
8204 procedure Build_Discriminal (Discrim : Entity_Id) is
8205 D_Minal : Entity_Id;
8206 CR_Disc : Entity_Id;
8209 -- A discriminal has the same name as the discriminant
8211 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
8213 Set_Ekind (D_Minal, E_In_Parameter);
8214 Set_Mechanism (D_Minal, Default_Mechanism);
8215 Set_Etype (D_Minal, Etype (Discrim));
8216 Set_Scope (D_Minal, Current_Scope);
8218 Set_Discriminal (Discrim, D_Minal);
8219 Set_Discriminal_Link (D_Minal, Discrim);
8221 -- For task types, build at once the discriminants of the corresponding
8222 -- record, which are needed if discriminants are used in entry defaults
8223 -- and in family bounds.
8225 if Is_Concurrent_Type (Current_Scope)
8226 or else Is_Limited_Type (Current_Scope)
8228 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
8230 Set_Ekind (CR_Disc, E_In_Parameter);
8231 Set_Mechanism (CR_Disc, Default_Mechanism);
8232 Set_Etype (CR_Disc, Etype (Discrim));
8233 Set_Scope (CR_Disc, Current_Scope);
8234 Set_Discriminal_Link (CR_Disc, Discrim);
8235 Set_CR_Discriminant (Discrim, CR_Disc);
8237 end Build_Discriminal;
8239 ------------------------------------
8240 -- Build_Discriminant_Constraints --
8241 ------------------------------------
8243 function Build_Discriminant_Constraints
8246 Derived_Def : Boolean := False) return Elist_Id
8248 C : constant Node_Id := Constraint (Def);
8249 Nb_Discr : constant Nat := Number_Discriminants (T);
8251 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
8252 -- Saves the expression corresponding to a given discriminant in T
8254 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
8255 -- Return the Position number within array Discr_Expr of a discriminant
8256 -- D within the discriminant list of the discriminated type T.
8262 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
8266 Disc := First_Discriminant (T);
8267 for J in Discr_Expr'Range loop
8272 Next_Discriminant (Disc);
8275 -- Note: Since this function is called on discriminants that are
8276 -- known to belong to the discriminated type, falling through the
8277 -- loop with no match signals an internal compiler error.
8279 raise Program_Error;
8282 -- Declarations local to Build_Discriminant_Constraints
8286 Elist : constant Elist_Id := New_Elmt_List;
8294 Discrim_Present : Boolean := False;
8296 -- Start of processing for Build_Discriminant_Constraints
8299 -- The following loop will process positional associations only.
8300 -- For a positional association, the (single) discriminant is
8301 -- implicitly specified by position, in textual order (RM 3.7.2).
8303 Discr := First_Discriminant (T);
8304 Constr := First (Constraints (C));
8305 for D in Discr_Expr'Range loop
8306 exit when Nkind (Constr) = N_Discriminant_Association;
8309 Error_Msg_N ("too few discriminants given in constraint", C);
8310 return New_Elmt_List;
8312 elsif Nkind (Constr) = N_Range
8313 or else (Nkind (Constr) = N_Attribute_Reference
8315 Attribute_Name (Constr) = Name_Range)
8318 ("a range is not a valid discriminant constraint", Constr);
8319 Discr_Expr (D) := Error;
8322 Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
8323 Discr_Expr (D) := Constr;
8326 Next_Discriminant (Discr);
8330 if No (Discr) and then Present (Constr) then
8331 Error_Msg_N ("too many discriminants given in constraint", Constr);
8332 return New_Elmt_List;
8335 -- Named associations can be given in any order, but if both positional
8336 -- and named associations are used in the same discriminant constraint,
8337 -- then positional associations must occur first, at their normal
8338 -- position. Hence once a named association is used, the rest of the
8339 -- discriminant constraint must use only named associations.
8341 while Present (Constr) loop
8343 -- Positional association forbidden after a named association
8345 if Nkind (Constr) /= N_Discriminant_Association then
8346 Error_Msg_N ("positional association follows named one", Constr);
8347 return New_Elmt_List;
8349 -- Otherwise it is a named association
8352 -- E records the type of the discriminants in the named
8353 -- association. All the discriminants specified in the same name
8354 -- association must have the same type.
8358 -- Search the list of discriminants in T to see if the simple name
8359 -- given in the constraint matches any of them.
8361 Id := First (Selector_Names (Constr));
8362 while Present (Id) loop
8365 -- If Original_Discriminant is present, we are processing a
8366 -- generic instantiation and this is an instance node. We need
8367 -- to find the name of the corresponding discriminant in the
8368 -- actual record type T and not the name of the discriminant in
8369 -- the generic formal. Example:
8372 -- type G (D : int) is private;
8374 -- subtype W is G (D => 1);
8376 -- type Rec (X : int) is record ... end record;
8377 -- package Q is new P (G => Rec);
8379 -- At the point of the instantiation, formal type G is Rec
8380 -- and therefore when reanalyzing "subtype W is G (D => 1);"
8381 -- which really looks like "subtype W is Rec (D => 1);" at
8382 -- the point of instantiation, we want to find the discriminant
8383 -- that corresponds to D in Rec, i.e. X.
8385 if Present (Original_Discriminant (Id))
8386 and then In_Instance
8388 Discr := Find_Corresponding_Discriminant (Id, T);
8392 Discr := First_Discriminant (T);
8393 while Present (Discr) loop
8394 if Chars (Discr) = Chars (Id) then
8399 Next_Discriminant (Discr);
8403 Error_Msg_N ("& does not match any discriminant", Id);
8404 return New_Elmt_List;
8406 -- If the parent type is a generic formal, preserve the
8407 -- name of the discriminant for subsequent instances.
8408 -- see comment at the beginning of this if statement.
8410 elsif Is_Generic_Type (Root_Type (T)) then
8411 Set_Original_Discriminant (Id, Discr);
8415 Position := Pos_Of_Discr (T, Discr);
8417 if Present (Discr_Expr (Position)) then
8418 Error_Msg_N ("duplicate constraint for discriminant&", Id);
8421 -- Each discriminant specified in the same named association
8422 -- must be associated with a separate copy of the
8423 -- corresponding expression.
8425 if Present (Next (Id)) then
8426 Expr := New_Copy_Tree (Expression (Constr));
8427 Set_Parent (Expr, Parent (Expression (Constr)));
8429 Expr := Expression (Constr);
8432 Discr_Expr (Position) := Expr;
8433 Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
8436 -- A discriminant association with more than one discriminant
8437 -- name is only allowed if the named discriminants are all of
8438 -- the same type (RM 3.7.1(8)).
8441 E := Base_Type (Etype (Discr));
8443 elsif Base_Type (Etype (Discr)) /= E then
8445 ("all discriminants in an association " &
8446 "must have the same type", Id);
8456 -- A discriminant constraint must provide exactly one value for each
8457 -- discriminant of the type (RM 3.7.1(8)).
8459 for J in Discr_Expr'Range loop
8460 if No (Discr_Expr (J)) then
8461 Error_Msg_N ("too few discriminants given in constraint", C);
8462 return New_Elmt_List;
8466 -- Determine if there are discriminant expressions in the constraint
8468 for J in Discr_Expr'Range loop
8469 if Denotes_Discriminant
8470 (Discr_Expr (J), Check_Concurrent => True)
8472 Discrim_Present := True;
8476 -- Build an element list consisting of the expressions given in the
8477 -- discriminant constraint and apply the appropriate checks. The list
8478 -- is constructed after resolving any named discriminant associations
8479 -- and therefore the expressions appear in the textual order of the
8482 Discr := First_Discriminant (T);
8483 for J in Discr_Expr'Range loop
8484 if Discr_Expr (J) /= Error then
8485 Append_Elmt (Discr_Expr (J), Elist);
8487 -- If any of the discriminant constraints is given by a
8488 -- discriminant and we are in a derived type declaration we
8489 -- have a discriminant renaming. Establish link between new
8490 -- and old discriminant.
8492 if Denotes_Discriminant (Discr_Expr (J)) then
8494 Set_Corresponding_Discriminant
8495 (Entity (Discr_Expr (J)), Discr);
8498 -- Force the evaluation of non-discriminant expressions.
8499 -- If we have found a discriminant in the constraint 3.4(26)
8500 -- and 3.8(18) demand that no range checks are performed are
8501 -- after evaluation. If the constraint is for a component
8502 -- definition that has a per-object constraint, expressions are
8503 -- evaluated but not checked either. In all other cases perform
8507 if Discrim_Present then
8510 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
8512 Has_Per_Object_Constraint
8513 (Defining_Identifier (Parent (Parent (Def))))
8517 elsif Is_Access_Type (Etype (Discr)) then
8518 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
8521 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
8524 Force_Evaluation (Discr_Expr (J));
8527 -- Check that the designated type of an access discriminant's
8528 -- expression is not a class-wide type unless the discriminant's
8529 -- designated type is also class-wide.
8531 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
8532 and then not Is_Class_Wide_Type
8533 (Designated_Type (Etype (Discr)))
8534 and then Etype (Discr_Expr (J)) /= Any_Type
8535 and then Is_Class_Wide_Type
8536 (Designated_Type (Etype (Discr_Expr (J))))
8538 Wrong_Type (Discr_Expr (J), Etype (Discr));
8540 elsif Is_Access_Type (Etype (Discr))
8541 and then not Is_Access_Constant (Etype (Discr))
8542 and then Is_Access_Type (Etype (Discr_Expr (J)))
8543 and then Is_Access_Constant (Etype (Discr_Expr (J)))
8546 ("constraint for discriminant& must be access to variable",
8551 Next_Discriminant (Discr);
8555 end Build_Discriminant_Constraints;
8557 ---------------------------------
8558 -- Build_Discriminated_Subtype --
8559 ---------------------------------
8561 procedure Build_Discriminated_Subtype
8565 Related_Nod : Node_Id;
8566 For_Access : Boolean := False)
8568 Has_Discrs : constant Boolean := Has_Discriminants (T);
8569 Constrained : constant Boolean :=
8571 and then not Is_Empty_Elmt_List (Elist)
8572 and then not Is_Class_Wide_Type (T))
8573 or else Is_Constrained (T);
8576 if Ekind (T) = E_Record_Type then
8578 Set_Ekind (Def_Id, E_Private_Subtype);
8579 Set_Is_For_Access_Subtype (Def_Id, True);
8581 Set_Ekind (Def_Id, E_Record_Subtype);
8584 -- Inherit preelaboration flag from base, for types for which it
8585 -- may have been set: records, private types, protected types.
8587 Set_Known_To_Have_Preelab_Init
8588 (Def_Id, Known_To_Have_Preelab_Init (T));
8590 elsif Ekind (T) = E_Task_Type then
8591 Set_Ekind (Def_Id, E_Task_Subtype);
8593 elsif Ekind (T) = E_Protected_Type then
8594 Set_Ekind (Def_Id, E_Protected_Subtype);
8595 Set_Known_To_Have_Preelab_Init
8596 (Def_Id, Known_To_Have_Preelab_Init (T));
8598 elsif Is_Private_Type (T) then
8599 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
8600 Set_Known_To_Have_Preelab_Init
8601 (Def_Id, Known_To_Have_Preelab_Init (T));
8603 elsif Is_Class_Wide_Type (T) then
8604 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
8607 -- Incomplete type. Attach subtype to list of dependents, to be
8608 -- completed with full view of parent type, unless is it the
8609 -- designated subtype of a record component within an init_proc.
8610 -- This last case arises for a component of an access type whose
8611 -- designated type is incomplete (e.g. a Taft Amendment type).
8612 -- The designated subtype is within an inner scope, and needs no
8613 -- elaboration, because only the access type is needed in the
8614 -- initialization procedure.
8616 Set_Ekind (Def_Id, Ekind (T));
8618 if For_Access and then Within_Init_Proc then
8621 Append_Elmt (Def_Id, Private_Dependents (T));
8625 Set_Etype (Def_Id, T);
8626 Init_Size_Align (Def_Id);
8627 Set_Has_Discriminants (Def_Id, Has_Discrs);
8628 Set_Is_Constrained (Def_Id, Constrained);
8630 Set_First_Entity (Def_Id, First_Entity (T));
8631 Set_Last_Entity (Def_Id, Last_Entity (T));
8632 Set_Has_Implicit_Dereference
8633 (Def_Id, Has_Implicit_Dereference (T));
8635 -- If the subtype is the completion of a private declaration, there may
8636 -- have been representation clauses for the partial view, and they must
8637 -- be preserved. Build_Derived_Type chains the inherited clauses with
8638 -- the ones appearing on the extension. If this comes from a subtype
8639 -- declaration, all clauses are inherited.
8641 if No (First_Rep_Item (Def_Id)) then
8642 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8645 if Is_Tagged_Type (T) then
8646 Set_Is_Tagged_Type (Def_Id);
8647 Make_Class_Wide_Type (Def_Id);
8650 Set_Stored_Constraint (Def_Id, No_Elist);
8653 Set_Discriminant_Constraint (Def_Id, Elist);
8654 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
8657 if Is_Tagged_Type (T) then
8659 -- Ada 2005 (AI-251): In case of concurrent types we inherit the
8660 -- concurrent record type (which has the list of primitive
8663 if Ada_Version >= Ada_2005
8664 and then Is_Concurrent_Type (T)
8666 Set_Corresponding_Record_Type (Def_Id,
8667 Corresponding_Record_Type (T));
8669 Set_Direct_Primitive_Operations (Def_Id,
8670 Direct_Primitive_Operations (T));
8673 Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (T));
8676 -- Subtypes introduced by component declarations do not need to be
8677 -- marked as delayed, and do not get freeze nodes, because the semantics
8678 -- verifies that the parents of the subtypes are frozen before the
8679 -- enclosing record is frozen.
8681 if not Is_Type (Scope (Def_Id)) then
8682 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
8684 if Is_Private_Type (T)
8685 and then Present (Full_View (T))
8687 Conditional_Delay (Def_Id, Full_View (T));
8689 Conditional_Delay (Def_Id, T);
8693 if Is_Record_Type (T) then
8694 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
8697 and then not Is_Empty_Elmt_List (Elist)
8698 and then not For_Access
8700 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
8701 elsif not For_Access then
8702 Set_Cloned_Subtype (Def_Id, T);
8705 end Build_Discriminated_Subtype;
8707 ---------------------------
8708 -- Build_Itype_Reference --
8709 ---------------------------
8711 procedure Build_Itype_Reference
8715 IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod));
8718 -- Itype references are only created for use by the back-end
8720 if Inside_A_Generic then
8723 Set_Itype (IR, Ityp);
8724 Insert_After (Nod, IR);
8726 end Build_Itype_Reference;
8728 ------------------------
8729 -- Build_Scalar_Bound --
8730 ------------------------
8732 function Build_Scalar_Bound
8735 Der_T : Entity_Id) return Node_Id
8737 New_Bound : Entity_Id;
8740 -- Note: not clear why this is needed, how can the original bound
8741 -- be unanalyzed at this point? and if it is, what business do we
8742 -- have messing around with it? and why is the base type of the
8743 -- parent type the right type for the resolution. It probably is
8744 -- not! It is OK for the new bound we are creating, but not for
8745 -- the old one??? Still if it never happens, no problem!
8747 Analyze_And_Resolve (Bound, Base_Type (Par_T));
8749 if Nkind_In (Bound, N_Integer_Literal, N_Real_Literal) then
8750 New_Bound := New_Copy (Bound);
8751 Set_Etype (New_Bound, Der_T);
8752 Set_Analyzed (New_Bound);
8754 elsif Is_Entity_Name (Bound) then
8755 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
8757 -- The following is almost certainly wrong. What business do we have
8758 -- relocating a node (Bound) that is presumably still attached to
8759 -- the tree elsewhere???
8762 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
8765 Set_Etype (New_Bound, Der_T);
8767 end Build_Scalar_Bound;
8769 --------------------------------
8770 -- Build_Underlying_Full_View --
8771 --------------------------------
8773 procedure Build_Underlying_Full_View
8778 Loc : constant Source_Ptr := Sloc (N);
8779 Subt : constant Entity_Id :=
8780 Make_Defining_Identifier
8781 (Loc, New_External_Name (Chars (Typ), 'S'));
8788 procedure Set_Discriminant_Name (Id : Node_Id);
8789 -- If the derived type has discriminants, they may rename discriminants
8790 -- of the parent. When building the full view of the parent, we need to
8791 -- recover the names of the original discriminants if the constraint is
8792 -- given by named associations.
8794 ---------------------------
8795 -- Set_Discriminant_Name --
8796 ---------------------------
8798 procedure Set_Discriminant_Name (Id : Node_Id) is
8802 Set_Original_Discriminant (Id, Empty);
8804 if Has_Discriminants (Typ) then
8805 Disc := First_Discriminant (Typ);
8806 while Present (Disc) loop
8807 if Chars (Disc) = Chars (Id)
8808 and then Present (Corresponding_Discriminant (Disc))
8810 Set_Chars (Id, Chars (Corresponding_Discriminant (Disc)));
8812 Next_Discriminant (Disc);
8815 end Set_Discriminant_Name;
8817 -- Start of processing for Build_Underlying_Full_View
8820 if Nkind (N) = N_Full_Type_Declaration then
8821 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
8823 elsif Nkind (N) = N_Subtype_Declaration then
8824 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
8826 elsif Nkind (N) = N_Component_Declaration then
8829 (Constraint (Subtype_Indication (Component_Definition (N))));
8832 raise Program_Error;
8835 C := First (Constraints (Constr));
8836 while Present (C) loop
8837 if Nkind (C) = N_Discriminant_Association then
8838 Id := First (Selector_Names (C));
8839 while Present (Id) loop
8840 Set_Discriminant_Name (Id);
8849 Make_Subtype_Declaration (Loc,
8850 Defining_Identifier => Subt,
8851 Subtype_Indication =>
8852 Make_Subtype_Indication (Loc,
8853 Subtype_Mark => New_Reference_To (Par, Loc),
8854 Constraint => New_Copy_Tree (Constr)));
8856 -- If this is a component subtype for an outer itype, it is not
8857 -- a list member, so simply set the parent link for analysis: if
8858 -- the enclosing type does not need to be in a declarative list,
8859 -- neither do the components.
8861 if Is_List_Member (N)
8862 and then Nkind (N) /= N_Component_Declaration
8864 Insert_Before (N, Indic);
8866 Set_Parent (Indic, Parent (N));
8870 Set_Underlying_Full_View (Typ, Full_View (Subt));
8871 end Build_Underlying_Full_View;
8873 -------------------------------
8874 -- Check_Abstract_Overriding --
8875 -------------------------------
8877 procedure Check_Abstract_Overriding (T : Entity_Id) is
8878 Alias_Subp : Entity_Id;
8884 procedure Check_Pragma_Implemented (Subp : Entity_Id);
8885 -- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine
8886 -- which has pragma Implemented already set. Check whether Subp's entity
8887 -- kind conforms to the implementation kind of the overridden routine.
8889 procedure Check_Pragma_Implemented
8891 Iface_Subp : Entity_Id);
8892 -- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine
8893 -- Iface_Subp and both entities have pragma Implemented already set on
8894 -- them. Check whether the two implementation kinds are conforming.
8896 procedure Inherit_Pragma_Implemented
8898 Iface_Subp : Entity_Id);
8899 -- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface
8900 -- subprogram Iface_Subp which has been marked by pragma Implemented.
8901 -- Propagate the implementation kind of Iface_Subp to Subp.
8903 ------------------------------
8904 -- Check_Pragma_Implemented --
8905 ------------------------------
8907 procedure Check_Pragma_Implemented (Subp : Entity_Id) is
8908 Iface_Alias : constant Entity_Id := Interface_Alias (Subp);
8909 Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias);
8910 Subp_Alias : constant Entity_Id := Alias (Subp);
8911 Contr_Typ : Entity_Id;
8912 Impl_Subp : Entity_Id;
8915 -- Subp must have an alias since it is a hidden entity used to link
8916 -- an interface subprogram to its overriding counterpart.
8918 pragma Assert (Present (Subp_Alias));
8920 -- Handle aliases to synchronized wrappers
8922 Impl_Subp := Subp_Alias;
8924 if Is_Primitive_Wrapper (Impl_Subp) then
8925 Impl_Subp := Wrapped_Entity (Impl_Subp);
8928 -- Extract the type of the controlling formal
8930 Contr_Typ := Etype (First_Formal (Subp_Alias));
8932 if Is_Concurrent_Record_Type (Contr_Typ) then
8933 Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ);
8936 -- An interface subprogram whose implementation kind is By_Entry must
8937 -- be implemented by an entry.
8939 if Impl_Kind = Name_By_Entry
8940 and then Ekind (Impl_Subp) /= E_Entry
8942 Error_Msg_Node_2 := Iface_Alias;
8944 ("type & must implement abstract subprogram & with an entry",
8945 Subp_Alias, Contr_Typ);
8947 elsif Impl_Kind = Name_By_Protected_Procedure then
8949 -- An interface subprogram whose implementation kind is By_
8950 -- Protected_Procedure cannot be implemented by a primitive
8951 -- procedure of a task type.
8953 if Ekind (Contr_Typ) /= E_Protected_Type then
8954 Error_Msg_Node_2 := Contr_Typ;
8956 ("interface subprogram & cannot be implemented by a " &
8957 "primitive procedure of task type &", Subp_Alias,
8960 -- An interface subprogram whose implementation kind is By_
8961 -- Protected_Procedure must be implemented by a procedure.
8963 elsif Ekind (Impl_Subp) /= E_Procedure then
8964 Error_Msg_Node_2 := Iface_Alias;
8966 ("type & must implement abstract subprogram & with a " &
8967 "procedure", Subp_Alias, Contr_Typ);
8970 end Check_Pragma_Implemented;
8972 ------------------------------
8973 -- Check_Pragma_Implemented --
8974 ------------------------------
8976 procedure Check_Pragma_Implemented
8978 Iface_Subp : Entity_Id)
8980 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
8981 Subp_Kind : constant Name_Id := Implementation_Kind (Subp);
8984 -- Ada 2012 (AI05-0030): The implementation kinds of an overridden
8985 -- and overriding subprogram are different. In general this is an
8986 -- error except when the implementation kind of the overridden
8987 -- subprograms is By_Any or Optional.
8989 if Iface_Kind /= Subp_Kind
8990 and then Iface_Kind /= Name_By_Any
8991 and then Iface_Kind /= Name_Optional
8993 if Iface_Kind = Name_By_Entry then
8995 ("incompatible implementation kind, overridden subprogram " &
8996 "is marked By_Entry", Subp);
8999 ("incompatible implementation kind, overridden subprogram " &
9000 "is marked By_Protected_Procedure", Subp);
9003 end Check_Pragma_Implemented;
9005 --------------------------------
9006 -- Inherit_Pragma_Implemented --
9007 --------------------------------
9009 procedure Inherit_Pragma_Implemented
9011 Iface_Subp : Entity_Id)
9013 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
9014 Loc : constant Source_Ptr := Sloc (Subp);
9015 Impl_Prag : Node_Id;
9018 -- Since the implementation kind is stored as a representation item
9019 -- rather than a flag, create a pragma node.
9023 Chars => Name_Implemented,
9024 Pragma_Argument_Associations => New_List (
9025 Make_Pragma_Argument_Association (Loc,
9027 New_Reference_To (Subp, Loc)),
9029 Make_Pragma_Argument_Association (Loc,
9030 Expression => Make_Identifier (Loc, Iface_Kind))));
9032 -- The pragma doesn't need to be analyzed because it is internally
9033 -- build. It is safe to directly register it as a rep item since we
9034 -- are only interested in the characters of the implementation kind.
9036 Record_Rep_Item (Subp, Impl_Prag);
9037 end Inherit_Pragma_Implemented;
9039 -- Start of processing for Check_Abstract_Overriding
9042 Op_List := Primitive_Operations (T);
9044 -- Loop to check primitive operations
9046 Elmt := First_Elmt (Op_List);
9047 while Present (Elmt) loop
9048 Subp := Node (Elmt);
9049 Alias_Subp := Alias (Subp);
9051 -- Inherited subprograms are identified by the fact that they do not
9052 -- come from source, and the associated source location is the
9053 -- location of the first subtype of the derived type.
9055 -- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for
9056 -- subprograms that "require overriding".
9058 -- Special exception, do not complain about failure to override the
9059 -- stream routines _Input and _Output, as well as the primitive
9060 -- operations used in dispatching selects since we always provide
9061 -- automatic overridings for these subprograms.
9063 -- Also ignore this rule for convention CIL since .NET libraries
9064 -- do bizarre things with interfaces???
9066 -- The partial view of T may have been a private extension, for
9067 -- which inherited functions dispatching on result are abstract.
9068 -- If the full view is a null extension, there is no need for
9069 -- overriding in Ada 2005, but wrappers need to be built for them
9070 -- (see exp_ch3, Build_Controlling_Function_Wrappers).
9072 if Is_Null_Extension (T)
9073 and then Has_Controlling_Result (Subp)
9074 and then Ada_Version >= Ada_2005
9075 and then Present (Alias_Subp)
9076 and then not Comes_From_Source (Subp)
9077 and then not Is_Abstract_Subprogram (Alias_Subp)
9078 and then not Is_Access_Type (Etype (Subp))
9082 -- Ada 2005 (AI-251): Internal entities of interfaces need no
9083 -- processing because this check is done with the aliased
9086 elsif Present (Interface_Alias (Subp)) then
9089 elsif (Is_Abstract_Subprogram (Subp)
9090 or else Requires_Overriding (Subp)
9092 (Has_Controlling_Result (Subp)
9093 and then Present (Alias_Subp)
9094 and then not Comes_From_Source (Subp)
9095 and then Sloc (Subp) = Sloc (First_Subtype (T))))
9096 and then not Is_TSS (Subp, TSS_Stream_Input)
9097 and then not Is_TSS (Subp, TSS_Stream_Output)
9098 and then not Is_Abstract_Type (T)
9099 and then Convention (T) /= Convention_CIL
9100 and then not Is_Predefined_Interface_Primitive (Subp)
9102 -- Ada 2005 (AI-251): Do not consider hidden entities associated
9103 -- with abstract interface types because the check will be done
9104 -- with the aliased entity (otherwise we generate a duplicated
9107 and then not Present (Interface_Alias (Subp))
9109 if Present (Alias_Subp) then
9111 -- Only perform the check for a derived subprogram when the
9112 -- type has an explicit record extension. This avoids incorrect
9113 -- flagging of abstract subprograms for the case of a type
9114 -- without an extension that is derived from a formal type
9115 -- with a tagged actual (can occur within a private part).
9117 -- Ada 2005 (AI-391): In the case of an inherited function with
9118 -- a controlling result of the type, the rule does not apply if
9119 -- the type is a null extension (unless the parent function
9120 -- itself is abstract, in which case the function must still be
9121 -- be overridden). The expander will generate an overriding
9122 -- wrapper function calling the parent subprogram (see
9123 -- Exp_Ch3.Make_Controlling_Wrapper_Functions).
9125 Type_Def := Type_Definition (Parent (T));
9127 if Nkind (Type_Def) = N_Derived_Type_Definition
9128 and then Present (Record_Extension_Part (Type_Def))
9130 (Ada_Version < Ada_2005
9131 or else not Is_Null_Extension (T)
9132 or else Ekind (Subp) = E_Procedure
9133 or else not Has_Controlling_Result (Subp)
9134 or else Is_Abstract_Subprogram (Alias_Subp)
9135 or else Requires_Overriding (Subp)
9136 or else Is_Access_Type (Etype (Subp)))
9138 -- Avoid reporting error in case of abstract predefined
9139 -- primitive inherited from interface type because the
9140 -- body of internally generated predefined primitives
9141 -- of tagged types are generated later by Freeze_Type
9143 if Is_Interface (Root_Type (T))
9144 and then Is_Abstract_Subprogram (Subp)
9145 and then Is_Predefined_Dispatching_Operation (Subp)
9146 and then not Comes_From_Source (Ultimate_Alias (Subp))
9152 ("type must be declared abstract or & overridden",
9155 -- Traverse the whole chain of aliased subprograms to
9156 -- complete the error notification. This is especially
9157 -- useful for traceability of the chain of entities when
9158 -- the subprogram corresponds with an interface
9159 -- subprogram (which may be defined in another package).
9161 if Present (Alias_Subp) then
9167 while Present (Alias (E)) loop
9169 -- Avoid reporting redundant errors on entities
9170 -- inherited from interfaces
9172 if Sloc (E) /= Sloc (T) then
9173 Error_Msg_Sloc := Sloc (E);
9175 ("\& has been inherited #", T, Subp);
9181 Error_Msg_Sloc := Sloc (E);
9183 -- AI05-0068: report if there is an overriding
9184 -- non-abstract subprogram that is invisible.
9187 and then not Is_Abstract_Subprogram (E)
9190 ("\& subprogram# is not visible",
9195 ("\& has been inherited from subprogram #",
9202 -- Ada 2005 (AI-345): Protected or task type implementing
9203 -- abstract interfaces.
9205 elsif Is_Concurrent_Record_Type (T)
9206 and then Present (Interfaces (T))
9208 -- The controlling formal of Subp must be of mode "out",
9209 -- "in out" or an access-to-variable to be overridden.
9211 if Ekind (First_Formal (Subp)) = E_In_Parameter
9212 and then Ekind (Subp) /= E_Function
9214 if not Is_Predefined_Dispatching_Operation (Subp)
9215 and then Is_Protected_Type
9216 (Corresponding_Concurrent_Type (T))
9218 Error_Msg_PT (T, Subp);
9221 -- Some other kind of overriding failure
9225 ("interface subprogram & must be overridden",
9228 -- Examine primitive operations of synchronized type,
9229 -- to find homonyms that have the wrong profile.
9236 First_Entity (Corresponding_Concurrent_Type (T));
9237 while Present (Prim) loop
9238 if Chars (Prim) = Chars (Subp) then
9240 ("profile is not type conformant with "
9241 & "prefixed view profile of "
9242 & "inherited operation&", Prim, Subp);
9252 Error_Msg_Node_2 := T;
9254 ("abstract subprogram& not allowed for type&", Subp);
9256 -- Also post unconditional warning on the type (unconditional
9257 -- so that if there are more than one of these cases, we get
9258 -- them all, and not just the first one).
9260 Error_Msg_Node_2 := Subp;
9261 Error_Msg_N ("nonabstract type& has abstract subprogram&!", T);
9265 -- Ada 2012 (AI05-0030): Perform some checks related to pragma
9268 -- Subp is an expander-generated procedure which maps an interface
9269 -- alias to a protected wrapper. The interface alias is flagged by
9270 -- pragma Implemented. Ensure that Subp is a procedure when the
9271 -- implementation kind is By_Protected_Procedure or an entry when
9274 if Ada_Version >= Ada_2012
9275 and then Is_Hidden (Subp)
9276 and then Present (Interface_Alias (Subp))
9277 and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented)
9279 Check_Pragma_Implemented (Subp);
9282 -- Subp is an interface primitive which overrides another interface
9283 -- primitive marked with pragma Implemented.
9285 if Ada_Version >= Ada_2012
9286 and then Present (Overridden_Operation (Subp))
9287 and then Has_Rep_Pragma
9288 (Overridden_Operation (Subp), Name_Implemented)
9290 -- If the overriding routine is also marked by Implemented, check
9291 -- that the two implementation kinds are conforming.
9293 if Has_Rep_Pragma (Subp, Name_Implemented) then
9294 Check_Pragma_Implemented
9296 Iface_Subp => Overridden_Operation (Subp));
9298 -- Otherwise the overriding routine inherits the implementation
9299 -- kind from the overridden subprogram.
9302 Inherit_Pragma_Implemented
9304 Iface_Subp => Overridden_Operation (Subp));
9310 end Check_Abstract_Overriding;
9312 ------------------------------------------------
9313 -- Check_Access_Discriminant_Requires_Limited --
9314 ------------------------------------------------
9316 procedure Check_Access_Discriminant_Requires_Limited
9321 -- A discriminant_specification for an access discriminant shall appear
9322 -- only in the declaration for a task or protected type, or for a type
9323 -- with the reserved word 'limited' in its definition or in one of its
9324 -- ancestors (RM 3.7(10)).
9326 -- AI-0063: The proper condition is that type must be immutably limited,
9327 -- or else be a partial view.
9329 if Nkind (Discriminant_Type (D)) = N_Access_Definition then
9330 if Is_Immutably_Limited_Type (Current_Scope)
9332 (Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration
9333 and then Limited_Present (Parent (Current_Scope)))
9339 ("access discriminants allowed only for limited types", Loc);
9342 end Check_Access_Discriminant_Requires_Limited;
9344 -----------------------------------
9345 -- Check_Aliased_Component_Types --
9346 -----------------------------------
9348 procedure Check_Aliased_Component_Types (T : Entity_Id) is
9352 -- ??? Also need to check components of record extensions, but not
9353 -- components of protected types (which are always limited).
9355 -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
9356 -- types to be unconstrained. This is safe because it is illegal to
9357 -- create access subtypes to such types with explicit discriminant
9360 if not Is_Limited_Type (T) then
9361 if Ekind (T) = E_Record_Type then
9362 C := First_Component (T);
9363 while Present (C) loop
9365 and then Has_Discriminants (Etype (C))
9366 and then not Is_Constrained (Etype (C))
9367 and then not In_Instance_Body
9368 and then Ada_Version < Ada_2005
9371 ("aliased component must be constrained (RM 3.6(11))",
9378 elsif Ekind (T) = E_Array_Type then
9379 if Has_Aliased_Components (T)
9380 and then Has_Discriminants (Component_Type (T))
9381 and then not Is_Constrained (Component_Type (T))
9382 and then not In_Instance_Body
9383 and then Ada_Version < Ada_2005
9386 ("aliased component type must be constrained (RM 3.6(11))",
9391 end Check_Aliased_Component_Types;
9393 ----------------------
9394 -- Check_Completion --
9395 ----------------------
9397 procedure Check_Completion (Body_Id : Node_Id := Empty) is
9400 procedure Post_Error;
9401 -- Post error message for lack of completion for entity E
9407 procedure Post_Error is
9409 procedure Missing_Body;
9410 -- Output missing body message
9416 procedure Missing_Body is
9418 -- Spec is in same unit, so we can post on spec
9420 if In_Same_Source_Unit (Body_Id, E) then
9421 Error_Msg_N ("missing body for &", E);
9423 -- Spec is in a separate unit, so we have to post on the body
9426 Error_Msg_NE ("missing body for & declared#!", Body_Id, E);
9430 -- Start of processing for Post_Error
9433 if not Comes_From_Source (E) then
9435 if Ekind_In (E, E_Task_Type, E_Protected_Type) then
9436 -- It may be an anonymous protected type created for a
9437 -- single variable. Post error on variable, if present.
9443 Var := First_Entity (Current_Scope);
9444 while Present (Var) loop
9445 exit when Etype (Var) = E
9446 and then Comes_From_Source (Var);
9451 if Present (Var) then
9458 -- If a generated entity has no completion, then either previous
9459 -- semantic errors have disabled the expansion phase, or else we had
9460 -- missing subunits, or else we are compiling without expansion,
9461 -- or else something is very wrong.
9463 if not Comes_From_Source (E) then
9465 (Serious_Errors_Detected > 0
9466 or else Configurable_Run_Time_Violations > 0
9467 or else Subunits_Missing
9468 or else not Expander_Active);
9471 -- Here for source entity
9474 -- Here if no body to post the error message, so we post the error
9475 -- on the declaration that has no completion. This is not really
9476 -- the right place to post it, think about this later ???
9478 if No (Body_Id) then
9481 ("missing full declaration for }", Parent (E), E);
9483 Error_Msg_NE ("missing body for &", Parent (E), E);
9486 -- Package body has no completion for a declaration that appears
9487 -- in the corresponding spec. Post error on the body, with a
9488 -- reference to the non-completed declaration.
9491 Error_Msg_Sloc := Sloc (E);
9494 Error_Msg_NE ("missing full declaration for }!", Body_Id, E);
9496 elsif Is_Overloadable (E)
9497 and then Current_Entity_In_Scope (E) /= E
9499 -- It may be that the completion is mistyped and appears as
9500 -- a distinct overloading of the entity.
9503 Candidate : constant Entity_Id :=
9504 Current_Entity_In_Scope (E);
9505 Decl : constant Node_Id :=
9506 Unit_Declaration_Node (Candidate);
9509 if Is_Overloadable (Candidate)
9510 and then Ekind (Candidate) = Ekind (E)
9511 and then Nkind (Decl) = N_Subprogram_Body
9512 and then Acts_As_Spec (Decl)
9514 Check_Type_Conformant (Candidate, E);
9528 -- Start of processing for Check_Completion
9531 E := First_Entity (Current_Scope);
9532 while Present (E) loop
9533 if Is_Intrinsic_Subprogram (E) then
9536 -- The following situation requires special handling: a child unit
9537 -- that appears in the context clause of the body of its parent:
9539 -- procedure Parent.Child (...);
9541 -- with Parent.Child;
9542 -- package body Parent is
9544 -- Here Parent.Child appears as a local entity, but should not be
9545 -- flagged as requiring completion, because it is a compilation
9548 -- Ignore missing completion for a subprogram that does not come from
9549 -- source (including the _Call primitive operation of RAS types,
9550 -- which has to have the flag Comes_From_Source for other purposes):
9551 -- we assume that the expander will provide the missing completion.
9552 -- In case of previous errors, other expansion actions that provide
9553 -- bodies for null procedures with not be invoked, so inhibit message
9556 -- Note that E_Operator is not in the list that follows, because
9557 -- this kind is reserved for predefined operators, that are
9558 -- intrinsic and do not need completion.
9560 elsif Ekind (E) = E_Function
9561 or else Ekind (E) = E_Procedure
9562 or else Ekind (E) = E_Generic_Function
9563 or else Ekind (E) = E_Generic_Procedure
9565 if Has_Completion (E) then
9568 elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then
9571 elsif Is_Subprogram (E)
9572 and then (not Comes_From_Source (E)
9573 or else Chars (E) = Name_uCall)
9578 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
9582 elsif Nkind (Parent (E)) = N_Procedure_Specification
9583 and then Null_Present (Parent (E))
9584 and then Serious_Errors_Detected > 0
9592 elsif Is_Entry (E) then
9593 if not Has_Completion (E) and then
9594 (Ekind (Scope (E)) = E_Protected_Object
9595 or else Ekind (Scope (E)) = E_Protected_Type)
9600 elsif Is_Package_Or_Generic_Package (E) then
9601 if Unit_Requires_Body (E) then
9602 if not Has_Completion (E)
9603 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
9609 elsif not Is_Child_Unit (E) then
9610 May_Need_Implicit_Body (E);
9613 -- A formal incomplete type (Ada 2012) does not require a completion;
9614 -- other incomplete type declarations do.
9616 elsif Ekind (E) = E_Incomplete_Type
9617 and then No (Underlying_Type (E))
9618 and then not Is_Generic_Type (E)
9622 elsif (Ekind (E) = E_Task_Type or else
9623 Ekind (E) = E_Protected_Type)
9624 and then not Has_Completion (E)
9628 -- A single task declared in the current scope is a constant, verify
9629 -- that the body of its anonymous type is in the same scope. If the
9630 -- task is defined elsewhere, this may be a renaming declaration for
9631 -- which no completion is needed.
9633 elsif Ekind (E) = E_Constant
9634 and then Ekind (Etype (E)) = E_Task_Type
9635 and then not Has_Completion (Etype (E))
9636 and then Scope (Etype (E)) = Current_Scope
9640 elsif Ekind (E) = E_Protected_Object
9641 and then not Has_Completion (Etype (E))
9645 elsif Ekind (E) = E_Record_Type then
9646 if Is_Tagged_Type (E) then
9647 Check_Abstract_Overriding (E);
9648 Check_Conventions (E);
9651 Check_Aliased_Component_Types (E);
9653 elsif Ekind (E) = E_Array_Type then
9654 Check_Aliased_Component_Types (E);
9660 end Check_Completion;
9662 ------------------------------------
9663 -- Check_CPP_Type_Has_No_Defaults --
9664 ------------------------------------
9666 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is
9667 Tdef : constant Node_Id := Type_Definition (Declaration_Node (T));
9672 -- Obtain the component list
9674 if Nkind (Tdef) = N_Record_Definition then
9675 Clist := Component_List (Tdef);
9676 else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition);
9677 Clist := Component_List (Record_Extension_Part (Tdef));
9680 -- Check all components to ensure no default expressions
9682 if Present (Clist) then
9683 Comp := First (Component_Items (Clist));
9684 while Present (Comp) loop
9685 if Present (Expression (Comp)) then
9687 ("component of imported 'C'P'P type cannot have "
9688 & "default expression", Expression (Comp));
9694 end Check_CPP_Type_Has_No_Defaults;
9696 ----------------------------
9697 -- Check_Delta_Expression --
9698 ----------------------------
9700 procedure Check_Delta_Expression (E : Node_Id) is
9702 if not (Is_Real_Type (Etype (E))) then
9703 Wrong_Type (E, Any_Real);
9705 elsif not Is_OK_Static_Expression (E) then
9706 Flag_Non_Static_Expr
9707 ("non-static expression used for delta value!", E);
9709 elsif not UR_Is_Positive (Expr_Value_R (E)) then
9710 Error_Msg_N ("delta expression must be positive", E);
9716 -- If any of above errors occurred, then replace the incorrect
9717 -- expression by the real 0.1, which should prevent further errors.
9720 Make_Real_Literal (Sloc (E), Ureal_Tenth));
9721 Analyze_And_Resolve (E, Standard_Float);
9722 end Check_Delta_Expression;
9724 -----------------------------
9725 -- Check_Digits_Expression --
9726 -----------------------------
9728 procedure Check_Digits_Expression (E : Node_Id) is
9730 if not (Is_Integer_Type (Etype (E))) then
9731 Wrong_Type (E, Any_Integer);
9733 elsif not Is_OK_Static_Expression (E) then
9734 Flag_Non_Static_Expr
9735 ("non-static expression used for digits value!", E);
9737 elsif Expr_Value (E) <= 0 then
9738 Error_Msg_N ("digits value must be greater than zero", E);
9744 -- If any of above errors occurred, then replace the incorrect
9745 -- expression by the integer 1, which should prevent further errors.
9747 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
9748 Analyze_And_Resolve (E, Standard_Integer);
9750 end Check_Digits_Expression;
9752 --------------------------
9753 -- Check_Initialization --
9754 --------------------------
9756 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
9758 if Is_Limited_Type (T)
9759 and then not In_Instance
9760 and then not In_Inlined_Body
9762 if not OK_For_Limited_Init (T, Exp) then
9764 -- In GNAT mode, this is just a warning, to allow it to be evilly
9765 -- turned off. Otherwise it is a real error.
9769 ("?cannot initialize entities of limited type!", Exp);
9771 elsif Ada_Version < Ada_2005 then
9773 -- The side effect removal machinery may generate illegal Ada
9774 -- code to avoid the usage of access types and 'reference in
9775 -- Alfa mode. Since this is legal code with respect to theorem
9776 -- proving, do not emit the error.
9779 and then Nkind (Exp) = N_Function_Call
9780 and then Nkind (Parent (Exp)) = N_Object_Declaration
9781 and then not Comes_From_Source
9782 (Defining_Identifier (Parent (Exp)))
9788 ("cannot initialize entities of limited type", Exp);
9789 Explain_Limited_Type (T, Exp);
9793 -- Specialize error message according to kind of illegal
9794 -- initial expression.
9796 if Nkind (Exp) = N_Type_Conversion
9797 and then Nkind (Expression (Exp)) = N_Function_Call
9800 ("illegal context for call"
9801 & " to function with limited result", Exp);
9805 ("initialization of limited object requires aggregate "
9806 & "or function call", Exp);
9811 end Check_Initialization;
9813 ----------------------
9814 -- Check_Interfaces --
9815 ----------------------
9817 procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is
9818 Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N));
9821 Iface_Def : Node_Id;
9822 Iface_Typ : Entity_Id;
9823 Parent_Node : Node_Id;
9825 Is_Task : Boolean := False;
9826 -- Set True if parent type or any progenitor is a task interface
9828 Is_Protected : Boolean := False;
9829 -- Set True if parent type or any progenitor is a protected interface
9831 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id);
9832 -- Check that a progenitor is compatible with declaration.
9833 -- Error is posted on Error_Node.
9839 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is
9840 Iface_Id : constant Entity_Id :=
9841 Defining_Identifier (Parent (Iface_Def));
9845 if Nkind (N) = N_Private_Extension_Declaration then
9848 Type_Def := Type_Definition (N);
9851 if Is_Task_Interface (Iface_Id) then
9854 elsif Is_Protected_Interface (Iface_Id) then
9855 Is_Protected := True;
9858 if Is_Synchronized_Interface (Iface_Id) then
9860 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
9861 -- extension derived from a synchronized interface must explicitly
9862 -- be declared synchronized, because the full view will be a
9863 -- synchronized type.
9865 if Nkind (N) = N_Private_Extension_Declaration then
9866 if not Synchronized_Present (N) then
9868 ("private extension of& must be explicitly synchronized",
9872 -- However, by 3.9.4(16/2), a full type that is a record extension
9873 -- is never allowed to derive from a synchronized interface (note
9874 -- that interfaces must be excluded from this check, because those
9875 -- are represented by derived type definitions in some cases).
9877 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition
9878 and then not Interface_Present (Type_Definition (N))
9880 Error_Msg_N ("record extension cannot derive from synchronized"
9881 & " interface", Error_Node);
9885 -- Check that the characteristics of the progenitor are compatible
9886 -- with the explicit qualifier in the declaration.
9887 -- The check only applies to qualifiers that come from source.
9888 -- Limited_Present also appears in the declaration of corresponding
9889 -- records, and the check does not apply to them.
9891 if Limited_Present (Type_Def)
9893 Is_Concurrent_Record_Type (Defining_Identifier (N))
9895 if Is_Limited_Interface (Parent_Type)
9896 and then not Is_Limited_Interface (Iface_Id)
9899 ("progenitor& must be limited interface",
9900 Error_Node, Iface_Id);
9903 (Task_Present (Iface_Def)
9904 or else Protected_Present (Iface_Def)
9905 or else Synchronized_Present (Iface_Def))
9906 and then Nkind (N) /= N_Private_Extension_Declaration
9907 and then not Error_Posted (N)
9910 ("progenitor& must be limited interface",
9911 Error_Node, Iface_Id);
9914 -- Protected interfaces can only inherit from limited, synchronized
9915 -- or protected interfaces.
9917 elsif Nkind (N) = N_Full_Type_Declaration
9918 and then Protected_Present (Type_Def)
9920 if Limited_Present (Iface_Def)
9921 or else Synchronized_Present (Iface_Def)
9922 or else Protected_Present (Iface_Def)
9926 elsif Task_Present (Iface_Def) then
9927 Error_Msg_N ("(Ada 2005) protected interface cannot inherit"
9928 & " from task interface", Error_Node);
9931 Error_Msg_N ("(Ada 2005) protected interface cannot inherit"
9932 & " from non-limited interface", Error_Node);
9935 -- Ada 2005 (AI-345): Synchronized interfaces can only inherit from
9936 -- limited and synchronized.
9938 elsif Synchronized_Present (Type_Def) then
9939 if Limited_Present (Iface_Def)
9940 or else Synchronized_Present (Iface_Def)
9944 elsif Protected_Present (Iface_Def)
9945 and then Nkind (N) /= N_Private_Extension_Declaration
9947 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
9948 & " from protected interface", Error_Node);
9950 elsif Task_Present (Iface_Def)
9951 and then Nkind (N) /= N_Private_Extension_Declaration
9953 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
9954 & " from task interface", Error_Node);
9956 elsif not Is_Limited_Interface (Iface_Id) then
9957 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
9958 & " from non-limited interface", Error_Node);
9961 -- Ada 2005 (AI-345): Task interfaces can only inherit from limited,
9962 -- synchronized or task interfaces.
9964 elsif Nkind (N) = N_Full_Type_Declaration
9965 and then Task_Present (Type_Def)
9967 if Limited_Present (Iface_Def)
9968 or else Synchronized_Present (Iface_Def)
9969 or else Task_Present (Iface_Def)
9973 elsif Protected_Present (Iface_Def) then
9974 Error_Msg_N ("(Ada 2005) task interface cannot inherit from"
9975 & " protected interface", Error_Node);
9978 Error_Msg_N ("(Ada 2005) task interface cannot inherit from"
9979 & " non-limited interface", Error_Node);
9984 -- Start of processing for Check_Interfaces
9987 if Is_Interface (Parent_Type) then
9988 if Is_Task_Interface (Parent_Type) then
9991 elsif Is_Protected_Interface (Parent_Type) then
9992 Is_Protected := True;
9996 if Nkind (N) = N_Private_Extension_Declaration then
9998 -- Check that progenitors are compatible with declaration
10000 Iface := First (Interface_List (Def));
10001 while Present (Iface) loop
10002 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
10004 Parent_Node := Parent (Base_Type (Iface_Typ));
10005 Iface_Def := Type_Definition (Parent_Node);
10007 if not Is_Interface (Iface_Typ) then
10008 Diagnose_Interface (Iface, Iface_Typ);
10011 Check_Ifaces (Iface_Def, Iface);
10017 if Is_Task and Is_Protected then
10019 ("type cannot derive from task and protected interface", N);
10025 -- Full type declaration of derived type.
10026 -- Check compatibility with parent if it is interface type
10028 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition
10029 and then Is_Interface (Parent_Type)
10031 Parent_Node := Parent (Parent_Type);
10033 -- More detailed checks for interface varieties
10036 (Iface_Def => Type_Definition (Parent_Node),
10037 Error_Node => Subtype_Indication (Type_Definition (N)));
10040 Iface := First (Interface_List (Def));
10041 while Present (Iface) loop
10042 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
10044 Parent_Node := Parent (Base_Type (Iface_Typ));
10045 Iface_Def := Type_Definition (Parent_Node);
10047 if not Is_Interface (Iface_Typ) then
10048 Diagnose_Interface (Iface, Iface_Typ);
10051 -- "The declaration of a specific descendant of an interface
10052 -- type freezes the interface type" RM 13.14
10054 Freeze_Before (N, Iface_Typ);
10055 Check_Ifaces (Iface_Def, Error_Node => Iface);
10061 if Is_Task and Is_Protected then
10063 ("type cannot derive from task and protected interface", N);
10065 end Check_Interfaces;
10067 ------------------------------------
10068 -- Check_Or_Process_Discriminants --
10069 ------------------------------------
10071 -- If an incomplete or private type declaration was already given for the
10072 -- type, the discriminants may have already been processed if they were
10073 -- present on the incomplete declaration. In this case a full conformance
10074 -- check has been performed in Find_Type_Name, and we then recheck here
10075 -- some properties that can't be checked on the partial view alone.
10076 -- Otherwise we call Process_Discriminants.
10078 procedure Check_Or_Process_Discriminants
10081 Prev : Entity_Id := Empty)
10084 if Has_Discriminants (T) then
10086 -- Discriminants are already set on T if they were already present
10087 -- on the partial view. Make them visible to component declarations.
10091 -- Discriminant on T (full view) referencing expr on partial view
10093 Prev_D : Entity_Id;
10094 -- Entity of corresponding discriminant on partial view
10097 -- Discriminant specification for full view, expression is the
10098 -- syntactic copy on full view (which has been checked for
10099 -- conformance with partial view), only used here to post error
10103 D := First_Discriminant (T);
10104 New_D := First (Discriminant_Specifications (N));
10105 while Present (D) loop
10106 Prev_D := Current_Entity (D);
10107 Set_Current_Entity (D);
10108 Set_Is_Immediately_Visible (D);
10109 Set_Homonym (D, Prev_D);
10111 -- Handle the case where there is an untagged partial view and
10112 -- the full view is tagged: must disallow discriminants with
10113 -- defaults, unless compiling for Ada 2012, which allows a
10114 -- limited tagged type to have defaulted discriminants (see
10115 -- AI05-0214). However, suppress the error here if it was
10116 -- already reported on the default expression of the partial
10119 if Is_Tagged_Type (T)
10120 and then Present (Expression (Parent (D)))
10121 and then (not Is_Limited_Type (Current_Scope)
10122 or else Ada_Version < Ada_2012)
10123 and then not Error_Posted (Expression (Parent (D)))
10125 if Ada_Version >= Ada_2012 then
10127 ("discriminants of nonlimited tagged type cannot have"
10129 Expression (New_D));
10132 ("discriminants of tagged type cannot have defaults",
10133 Expression (New_D));
10137 -- Ada 2005 (AI-230): Access discriminant allowed in
10138 -- non-limited record types.
10140 if Ada_Version < Ada_2005 then
10142 -- This restriction gets applied to the full type here. It
10143 -- has already been applied earlier to the partial view.
10145 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
10148 Next_Discriminant (D);
10153 elsif Present (Discriminant_Specifications (N)) then
10154 Process_Discriminants (N, Prev);
10156 end Check_Or_Process_Discriminants;
10158 ----------------------
10159 -- Check_Real_Bound --
10160 ----------------------
10162 procedure Check_Real_Bound (Bound : Node_Id) is
10164 if not Is_Real_Type (Etype (Bound)) then
10166 ("bound in real type definition must be of real type", Bound);
10168 elsif not Is_OK_Static_Expression (Bound) then
10169 Flag_Non_Static_Expr
10170 ("non-static expression used for real type bound!", Bound);
10177 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
10179 Resolve (Bound, Standard_Float);
10180 end Check_Real_Bound;
10182 ------------------------------
10183 -- Complete_Private_Subtype --
10184 ------------------------------
10186 procedure Complete_Private_Subtype
10189 Full_Base : Entity_Id;
10190 Related_Nod : Node_Id)
10192 Save_Next_Entity : Entity_Id;
10193 Save_Homonym : Entity_Id;
10196 -- Set semantic attributes for (implicit) private subtype completion.
10197 -- If the full type has no discriminants, then it is a copy of the full
10198 -- view of the base. Otherwise, it is a subtype of the base with a
10199 -- possible discriminant constraint. Save and restore the original
10200 -- Next_Entity field of full to ensure that the calls to Copy_Node
10201 -- do not corrupt the entity chain.
10203 -- Note that the type of the full view is the same entity as the type of
10204 -- the partial view. In this fashion, the subtype has access to the
10205 -- correct view of the parent.
10207 Save_Next_Entity := Next_Entity (Full);
10208 Save_Homonym := Homonym (Priv);
10210 case Ekind (Full_Base) is
10211 when E_Record_Type |
10217 Copy_Node (Priv, Full);
10219 Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
10220 Set_First_Entity (Full, First_Entity (Full_Base));
10221 Set_Last_Entity (Full, Last_Entity (Full_Base));
10224 Copy_Node (Full_Base, Full);
10225 Set_Chars (Full, Chars (Priv));
10226 Conditional_Delay (Full, Priv);
10227 Set_Sloc (Full, Sloc (Priv));
10230 Set_Next_Entity (Full, Save_Next_Entity);
10231 Set_Homonym (Full, Save_Homonym);
10232 Set_Associated_Node_For_Itype (Full, Related_Nod);
10234 -- Set common attributes for all subtypes: kind, convention, etc.
10236 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
10237 Set_Convention (Full, Convention (Full_Base));
10239 -- The Etype of the full view is inconsistent. Gigi needs to see the
10240 -- structural full view, which is what the current scheme gives:
10241 -- the Etype of the full view is the etype of the full base. However,
10242 -- if the full base is a derived type, the full view then looks like
10243 -- a subtype of the parent, not a subtype of the full base. If instead
10246 -- Set_Etype (Full, Full_Base);
10248 -- then we get inconsistencies in the front-end (confusion between
10249 -- views). Several outstanding bugs are related to this ???
10251 Set_Is_First_Subtype (Full, False);
10252 Set_Scope (Full, Scope (Priv));
10253 Set_Size_Info (Full, Full_Base);
10254 Set_RM_Size (Full, RM_Size (Full_Base));
10255 Set_Is_Itype (Full);
10257 -- A subtype of a private-type-without-discriminants, whose full-view
10258 -- has discriminants with default expressions, is not constrained!
10260 if not Has_Discriminants (Priv) then
10261 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
10263 if Has_Discriminants (Full_Base) then
10264 Set_Discriminant_Constraint
10265 (Full, Discriminant_Constraint (Full_Base));
10267 -- The partial view may have been indefinite, the full view
10270 Set_Has_Unknown_Discriminants
10271 (Full, Has_Unknown_Discriminants (Full_Base));
10275 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
10276 Set_Depends_On_Private (Full, Has_Private_Component (Full));
10278 -- Freeze the private subtype entity if its parent is delayed, and not
10279 -- already frozen. We skip this processing if the type is an anonymous
10280 -- subtype of a record component, or is the corresponding record of a
10281 -- protected type, since ???
10283 if not Is_Type (Scope (Full)) then
10284 Set_Has_Delayed_Freeze (Full,
10285 Has_Delayed_Freeze (Full_Base)
10286 and then (not Is_Frozen (Full_Base)));
10289 Set_Freeze_Node (Full, Empty);
10290 Set_Is_Frozen (Full, False);
10291 Set_Full_View (Priv, Full);
10293 if Has_Discriminants (Full) then
10294 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
10295 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
10297 if Has_Unknown_Discriminants (Full) then
10298 Set_Discriminant_Constraint (Full, No_Elist);
10302 if Ekind (Full_Base) = E_Record_Type
10303 and then Has_Discriminants (Full_Base)
10304 and then Has_Discriminants (Priv) -- might not, if errors
10305 and then not Has_Unknown_Discriminants (Priv)
10306 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
10308 Create_Constrained_Components
10309 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
10311 -- If the full base is itself derived from private, build a congruent
10312 -- subtype of its underlying type, for use by the back end. For a
10313 -- constrained record component, the declaration cannot be placed on
10314 -- the component list, but it must nevertheless be built an analyzed, to
10315 -- supply enough information for Gigi to compute the size of component.
10317 elsif Ekind (Full_Base) in Private_Kind
10318 and then Is_Derived_Type (Full_Base)
10319 and then Has_Discriminants (Full_Base)
10320 and then (Ekind (Current_Scope) /= E_Record_Subtype)
10322 if not Is_Itype (Priv)
10324 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
10326 Build_Underlying_Full_View
10327 (Parent (Priv), Full, Etype (Full_Base));
10329 elsif Nkind (Related_Nod) = N_Component_Declaration then
10330 Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
10333 elsif Is_Record_Type (Full_Base) then
10335 -- Show Full is simply a renaming of Full_Base
10337 Set_Cloned_Subtype (Full, Full_Base);
10340 -- It is unsafe to share to bounds of a scalar type, because the Itype
10341 -- is elaborated on demand, and if a bound is non-static then different
10342 -- orders of elaboration in different units will lead to different
10343 -- external symbols.
10345 if Is_Scalar_Type (Full_Base) then
10346 Set_Scalar_Range (Full,
10347 Make_Range (Sloc (Related_Nod),
10349 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
10351 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
10353 -- This completion inherits the bounds of the full parent, but if
10354 -- the parent is an unconstrained floating point type, so is the
10357 if Is_Floating_Point_Type (Full_Base) then
10358 Set_Includes_Infinities
10359 (Scalar_Range (Full), Has_Infinities (Full_Base));
10363 -- ??? It seems that a lot of fields are missing that should be copied
10364 -- from Full_Base to Full. Here are some that are introduced in a
10365 -- non-disruptive way but a cleanup is necessary.
10367 if Is_Tagged_Type (Full_Base) then
10368 Set_Is_Tagged_Type (Full);
10369 Set_Direct_Primitive_Operations (Full,
10370 Direct_Primitive_Operations (Full_Base));
10372 -- Inherit class_wide type of full_base in case the partial view was
10373 -- not tagged. Otherwise it has already been created when the private
10374 -- subtype was analyzed.
10376 if No (Class_Wide_Type (Full)) then
10377 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
10380 -- If this is a subtype of a protected or task type, constrain its
10381 -- corresponding record, unless this is a subtype without constraints,
10382 -- i.e. a simple renaming as with an actual subtype in an instance.
10384 elsif Is_Concurrent_Type (Full_Base) then
10385 if Has_Discriminants (Full)
10386 and then Present (Corresponding_Record_Type (Full_Base))
10388 not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
10390 Set_Corresponding_Record_Type (Full,
10391 Constrain_Corresponding_Record
10392 (Full, Corresponding_Record_Type (Full_Base),
10393 Related_Nod, Full_Base));
10396 Set_Corresponding_Record_Type (Full,
10397 Corresponding_Record_Type (Full_Base));
10401 -- Link rep item chain, and also setting of Has_Predicates from private
10402 -- subtype to full subtype, since we will need these on the full subtype
10403 -- to create the predicate function. Note that the full subtype may
10404 -- already have rep items, inherited from the full view of the base
10405 -- type, so we must be sure not to overwrite these entries.
10410 Next_Item : Node_Id;
10413 Item := First_Rep_Item (Full);
10415 -- If no existing rep items on full type, we can just link directly
10416 -- to the list of items on the private type.
10419 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
10421 -- Otherwise, search to the end of items currently linked to the full
10422 -- subtype and append the private items to the end. However, if Priv
10423 -- and Full already have the same list of rep items, then the append
10424 -- is not done, as that would create a circularity.
10426 elsif Item /= First_Rep_Item (Priv) then
10430 Next_Item := Next_Rep_Item (Item);
10431 exit when No (Next_Item);
10434 -- If the private view has aspect specifications, the full view
10435 -- inherits them. Since these aspects may already have been
10436 -- attached to the full view during derivation, do not append
10437 -- them if already present.
10439 if Item = First_Rep_Item (Priv) then
10445 -- And link the private type items at the end of the chain
10448 Set_Next_Rep_Item (Item, First_Rep_Item (Priv));
10453 -- Make sure Has_Predicates is set on full type if it is set on the
10454 -- private type. Note that it may already be set on the full type and
10455 -- if so, we don't want to unset it.
10457 if Has_Predicates (Priv) then
10458 Set_Has_Predicates (Full);
10460 end Complete_Private_Subtype;
10462 ----------------------------
10463 -- Constant_Redeclaration --
10464 ----------------------------
10466 procedure Constant_Redeclaration
10471 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
10472 Obj_Def : constant Node_Id := Object_Definition (N);
10475 procedure Check_Possible_Deferred_Completion
10476 (Prev_Id : Entity_Id;
10477 Prev_Obj_Def : Node_Id;
10478 Curr_Obj_Def : Node_Id);
10479 -- Determine whether the two object definitions describe the partial
10480 -- and the full view of a constrained deferred constant. Generate
10481 -- a subtype for the full view and verify that it statically matches
10482 -- the subtype of the partial view.
10484 procedure Check_Recursive_Declaration (Typ : Entity_Id);
10485 -- If deferred constant is an access type initialized with an allocator,
10486 -- check whether there is an illegal recursion in the definition,
10487 -- through a default value of some record subcomponent. This is normally
10488 -- detected when generating init procs, but requires this additional
10489 -- mechanism when expansion is disabled.
10491 ----------------------------------------
10492 -- Check_Possible_Deferred_Completion --
10493 ----------------------------------------
10495 procedure Check_Possible_Deferred_Completion
10496 (Prev_Id : Entity_Id;
10497 Prev_Obj_Def : Node_Id;
10498 Curr_Obj_Def : Node_Id)
10501 if Nkind (Prev_Obj_Def) = N_Subtype_Indication
10502 and then Present (Constraint (Prev_Obj_Def))
10503 and then Nkind (Curr_Obj_Def) = N_Subtype_Indication
10504 and then Present (Constraint (Curr_Obj_Def))
10507 Loc : constant Source_Ptr := Sloc (N);
10508 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
10509 Decl : constant Node_Id :=
10510 Make_Subtype_Declaration (Loc,
10511 Defining_Identifier => Def_Id,
10512 Subtype_Indication =>
10513 Relocate_Node (Curr_Obj_Def));
10516 Insert_Before_And_Analyze (N, Decl);
10517 Set_Etype (Id, Def_Id);
10519 if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then
10520 Error_Msg_Sloc := Sloc (Prev_Id);
10521 Error_Msg_N ("subtype does not statically match deferred " &
10522 "declaration#", N);
10526 end Check_Possible_Deferred_Completion;
10528 ---------------------------------
10529 -- Check_Recursive_Declaration --
10530 ---------------------------------
10532 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
10536 if Is_Record_Type (Typ) then
10537 Comp := First_Component (Typ);
10538 while Present (Comp) loop
10539 if Comes_From_Source (Comp) then
10540 if Present (Expression (Parent (Comp)))
10541 and then Is_Entity_Name (Expression (Parent (Comp)))
10542 and then Entity (Expression (Parent (Comp))) = Prev
10544 Error_Msg_Sloc := Sloc (Parent (Comp));
10546 ("illegal circularity with declaration for&#",
10550 elsif Is_Record_Type (Etype (Comp)) then
10551 Check_Recursive_Declaration (Etype (Comp));
10555 Next_Component (Comp);
10558 end Check_Recursive_Declaration;
10560 -- Start of processing for Constant_Redeclaration
10563 if Nkind (Parent (Prev)) = N_Object_Declaration then
10564 if Nkind (Object_Definition
10565 (Parent (Prev))) = N_Subtype_Indication
10567 -- Find type of new declaration. The constraints of the two
10568 -- views must match statically, but there is no point in
10569 -- creating an itype for the full view.
10571 if Nkind (Obj_Def) = N_Subtype_Indication then
10572 Find_Type (Subtype_Mark (Obj_Def));
10573 New_T := Entity (Subtype_Mark (Obj_Def));
10576 Find_Type (Obj_Def);
10577 New_T := Entity (Obj_Def);
10583 -- The full view may impose a constraint, even if the partial
10584 -- view does not, so construct the subtype.
10586 New_T := Find_Type_Of_Object (Obj_Def, N);
10591 -- Current declaration is illegal, diagnosed below in Enter_Name
10597 -- If previous full declaration or a renaming declaration exists, or if
10598 -- a homograph is present, let Enter_Name handle it, either with an
10599 -- error or with the removal of an overridden implicit subprogram.
10601 if Ekind (Prev) /= E_Constant
10602 or else Nkind (Parent (Prev)) = N_Object_Renaming_Declaration
10603 or else Present (Expression (Parent (Prev)))
10604 or else Present (Full_View (Prev))
10608 -- Verify that types of both declarations match, or else that both types
10609 -- are anonymous access types whose designated subtypes statically match
10610 -- (as allowed in Ada 2005 by AI-385).
10612 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
10614 (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
10615 or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
10616 or else Is_Access_Constant (Etype (New_T)) /=
10617 Is_Access_Constant (Etype (Prev))
10618 or else Can_Never_Be_Null (Etype (New_T)) /=
10619 Can_Never_Be_Null (Etype (Prev))
10620 or else Null_Exclusion_Present (Parent (Prev)) /=
10621 Null_Exclusion_Present (Parent (Id))
10622 or else not Subtypes_Statically_Match
10623 (Designated_Type (Etype (Prev)),
10624 Designated_Type (Etype (New_T))))
10626 Error_Msg_Sloc := Sloc (Prev);
10627 Error_Msg_N ("type does not match declaration#", N);
10628 Set_Full_View (Prev, Id);
10629 Set_Etype (Id, Any_Type);
10632 Null_Exclusion_Present (Parent (Prev))
10633 and then not Null_Exclusion_Present (N)
10635 Error_Msg_Sloc := Sloc (Prev);
10636 Error_Msg_N ("null-exclusion does not match declaration#", N);
10637 Set_Full_View (Prev, Id);
10638 Set_Etype (Id, Any_Type);
10640 -- If so, process the full constant declaration
10643 -- RM 7.4 (6): If the subtype defined by the subtype_indication in
10644 -- the deferred declaration is constrained, then the subtype defined
10645 -- by the subtype_indication in the full declaration shall match it
10648 Check_Possible_Deferred_Completion
10650 Prev_Obj_Def => Object_Definition (Parent (Prev)),
10651 Curr_Obj_Def => Obj_Def);
10653 Set_Full_View (Prev, Id);
10654 Set_Is_Public (Id, Is_Public (Prev));
10655 Set_Is_Internal (Id);
10656 Append_Entity (Id, Current_Scope);
10658 -- Check ALIASED present if present before (RM 7.4(7))
10660 if Is_Aliased (Prev)
10661 and then not Aliased_Present (N)
10663 Error_Msg_Sloc := Sloc (Prev);
10664 Error_Msg_N ("ALIASED required (see declaration#)", N);
10667 -- Check that placement is in private part and that the incomplete
10668 -- declaration appeared in the visible part.
10670 if Ekind (Current_Scope) = E_Package
10671 and then not In_Private_Part (Current_Scope)
10673 Error_Msg_Sloc := Sloc (Prev);
10675 ("full constant for declaration#"
10676 & " must be in private part", N);
10678 elsif Ekind (Current_Scope) = E_Package
10680 List_Containing (Parent (Prev)) /=
10681 Visible_Declarations
10682 (Specification (Unit_Declaration_Node (Current_Scope)))
10685 ("deferred constant must be declared in visible part",
10689 if Is_Access_Type (T)
10690 and then Nkind (Expression (N)) = N_Allocator
10692 Check_Recursive_Declaration (Designated_Type (T));
10695 end Constant_Redeclaration;
10697 ----------------------
10698 -- Constrain_Access --
10699 ----------------------
10701 procedure Constrain_Access
10702 (Def_Id : in out Entity_Id;
10704 Related_Nod : Node_Id)
10706 T : constant Entity_Id := Entity (Subtype_Mark (S));
10707 Desig_Type : constant Entity_Id := Designated_Type (T);
10708 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
10709 Constraint_OK : Boolean := True;
10711 function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean;
10712 -- Simple predicate to test for defaulted discriminants
10713 -- Shouldn't this be in sem_util???
10715 ---------------------------------
10716 -- Has_Defaulted_Discriminants --
10717 ---------------------------------
10719 function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean is
10721 return Has_Discriminants (Typ)
10722 and then Present (First_Discriminant (Typ))
10724 (Discriminant_Default_Value (First_Discriminant (Typ)));
10725 end Has_Defaulted_Discriminants;
10727 -- Start of processing for Constrain_Access
10730 if Is_Array_Type (Desig_Type) then
10731 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
10733 elsif (Is_Record_Type (Desig_Type)
10734 or else Is_Incomplete_Or_Private_Type (Desig_Type))
10735 and then not Is_Constrained (Desig_Type)
10737 -- ??? The following code is a temporary kludge to ignore a
10738 -- discriminant constraint on access type if it is constraining
10739 -- the current record. Avoid creating the implicit subtype of the
10740 -- record we are currently compiling since right now, we cannot
10741 -- handle these. For now, just return the access type itself.
10743 if Desig_Type = Current_Scope
10744 and then No (Def_Id)
10746 Set_Ekind (Desig_Subtype, E_Record_Subtype);
10747 Def_Id := Entity (Subtype_Mark (S));
10749 -- This call added to ensure that the constraint is analyzed
10750 -- (needed for a B test). Note that we still return early from
10751 -- this procedure to avoid recursive processing. ???
10753 Constrain_Discriminated_Type
10754 (Desig_Subtype, S, Related_Nod, For_Access => True);
10758 -- Enforce rule that the constraint is illegal if there is an
10759 -- unconstrained view of the designated type. This means that the
10760 -- partial view (either a private type declaration or a derivation
10761 -- from a private type) has no discriminants. (Defect Report
10762 -- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001).
10764 -- Rule updated for Ada 2005: the private type is said to have
10765 -- a constrained partial view, given that objects of the type
10766 -- can be declared. Furthermore, the rule applies to all access
10767 -- types, unlike the rule concerning default discriminants (see
10770 if (Ekind (T) = E_General_Access_Type
10771 or else Ada_Version >= Ada_2005)
10772 and then Has_Private_Declaration (Desig_Type)
10773 and then In_Open_Scopes (Scope (Desig_Type))
10774 and then Has_Discriminants (Desig_Type)
10777 Pack : constant Node_Id :=
10778 Unit_Declaration_Node (Scope (Desig_Type));
10783 if Nkind (Pack) = N_Package_Declaration then
10784 Decls := Visible_Declarations (Specification (Pack));
10785 Decl := First (Decls);
10786 while Present (Decl) loop
10787 if (Nkind (Decl) = N_Private_Type_Declaration
10789 Chars (Defining_Identifier (Decl)) =
10790 Chars (Desig_Type))
10793 (Nkind (Decl) = N_Full_Type_Declaration
10795 Chars (Defining_Identifier (Decl)) =
10797 and then Is_Derived_Type (Desig_Type)
10799 Has_Private_Declaration (Etype (Desig_Type)))
10801 if No (Discriminant_Specifications (Decl)) then
10803 ("cannot constrain access type if designated " &
10804 "type has constrained partial view", S);
10816 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
10817 For_Access => True);
10819 elsif (Is_Task_Type (Desig_Type)
10820 or else Is_Protected_Type (Desig_Type))
10821 and then not Is_Constrained (Desig_Type)
10823 Constrain_Concurrent
10824 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
10827 Error_Msg_N ("invalid constraint on access type", S);
10828 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
10829 Constraint_OK := False;
10832 if No (Def_Id) then
10833 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
10835 Set_Ekind (Def_Id, E_Access_Subtype);
10838 if Constraint_OK then
10839 Set_Etype (Def_Id, Base_Type (T));
10841 if Is_Private_Type (Desig_Type) then
10842 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
10845 Set_Etype (Def_Id, Any_Type);
10848 Set_Size_Info (Def_Id, T);
10849 Set_Is_Constrained (Def_Id, Constraint_OK);
10850 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
10851 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
10852 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
10854 Conditional_Delay (Def_Id, T);
10856 -- AI-363 : Subtypes of general access types whose designated types have
10857 -- default discriminants are disallowed. In instances, the rule has to
10858 -- be checked against the actual, of which T is the subtype. In a
10859 -- generic body, the rule is checked assuming that the actual type has
10860 -- defaulted discriminants.
10862 if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then
10863 if Ekind (Base_Type (T)) = E_General_Access_Type
10864 and then Has_Defaulted_Discriminants (Desig_Type)
10866 if Ada_Version < Ada_2005 then
10868 ("access subtype of general access type would not " &
10869 "be allowed in Ada 2005?", S);
10872 ("access subtype of general access type not allowed", S);
10875 Error_Msg_N ("\discriminants have defaults", S);
10877 elsif Is_Access_Type (T)
10878 and then Is_Generic_Type (Desig_Type)
10879 and then Has_Discriminants (Desig_Type)
10880 and then In_Package_Body (Current_Scope)
10882 if Ada_Version < Ada_2005 then
10884 ("access subtype would not be allowed in generic body " &
10885 "in Ada 2005?", S);
10888 ("access subtype not allowed in generic body", S);
10892 ("\designated type is a discriminated formal", S);
10895 end Constrain_Access;
10897 ---------------------
10898 -- Constrain_Array --
10899 ---------------------
10901 procedure Constrain_Array
10902 (Def_Id : in out Entity_Id;
10904 Related_Nod : Node_Id;
10905 Related_Id : Entity_Id;
10906 Suffix : Character)
10908 C : constant Node_Id := Constraint (SI);
10909 Number_Of_Constraints : Nat := 0;
10912 Constraint_OK : Boolean := True;
10915 T := Entity (Subtype_Mark (SI));
10917 if Ekind (T) in Access_Kind then
10918 T := Designated_Type (T);
10921 -- If an index constraint follows a subtype mark in a subtype indication
10922 -- then the type or subtype denoted by the subtype mark must not already
10923 -- impose an index constraint. The subtype mark must denote either an
10924 -- unconstrained array type or an access type whose designated type
10925 -- is such an array type... (RM 3.6.1)
10927 if Is_Constrained (T) then
10928 Error_Msg_N ("array type is already constrained", Subtype_Mark (SI));
10929 Constraint_OK := False;
10932 S := First (Constraints (C));
10933 while Present (S) loop
10934 Number_Of_Constraints := Number_Of_Constraints + 1;
10938 -- In either case, the index constraint must provide a discrete
10939 -- range for each index of the array type and the type of each
10940 -- discrete range must be the same as that of the corresponding
10941 -- index. (RM 3.6.1)
10943 if Number_Of_Constraints /= Number_Dimensions (T) then
10944 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
10945 Constraint_OK := False;
10948 S := First (Constraints (C));
10949 Index := First_Index (T);
10952 -- Apply constraints to each index type
10954 for J in 1 .. Number_Of_Constraints loop
10955 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
10963 if No (Def_Id) then
10965 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
10966 Set_Parent (Def_Id, Related_Nod);
10969 Set_Ekind (Def_Id, E_Array_Subtype);
10972 Set_Size_Info (Def_Id, (T));
10973 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
10974 Set_Etype (Def_Id, Base_Type (T));
10976 if Constraint_OK then
10977 Set_First_Index (Def_Id, First (Constraints (C)));
10979 Set_First_Index (Def_Id, First_Index (T));
10982 Set_Is_Constrained (Def_Id, True);
10983 Set_Is_Aliased (Def_Id, Is_Aliased (T));
10984 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
10986 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
10987 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
10989 -- A subtype does not inherit the packed_array_type of is parent. We
10990 -- need to initialize the attribute because if Def_Id is previously
10991 -- analyzed through a limited_with clause, it will have the attributes
10992 -- of an incomplete type, one of which is an Elist that overlaps the
10993 -- Packed_Array_Type field.
10995 Set_Packed_Array_Type (Def_Id, Empty);
10997 -- Build a freeze node if parent still needs one. Also make sure that
10998 -- the Depends_On_Private status is set because the subtype will need
10999 -- reprocessing at the time the base type does, and also we must set a
11000 -- conditional delay.
11002 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
11003 Conditional_Delay (Def_Id, T);
11004 end Constrain_Array;
11006 ------------------------------
11007 -- Constrain_Component_Type --
11008 ------------------------------
11010 function Constrain_Component_Type
11012 Constrained_Typ : Entity_Id;
11013 Related_Node : Node_Id;
11015 Constraints : Elist_Id) return Entity_Id
11017 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
11018 Compon_Type : constant Entity_Id := Etype (Comp);
11020 function Build_Constrained_Array_Type
11021 (Old_Type : Entity_Id) return Entity_Id;
11022 -- If Old_Type is an array type, one of whose indexes is constrained
11023 -- by a discriminant, build an Itype whose constraint replaces the
11024 -- discriminant with its value in the constraint.
11026 function Build_Constrained_Discriminated_Type
11027 (Old_Type : Entity_Id) return Entity_Id;
11028 -- Ditto for record components
11030 function Build_Constrained_Access_Type
11031 (Old_Type : Entity_Id) return Entity_Id;
11032 -- Ditto for access types. Makes use of previous two functions, to
11033 -- constrain designated type.
11035 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
11036 -- T is an array or discriminated type, C is a list of constraints
11037 -- that apply to T. This routine builds the constrained subtype.
11039 function Is_Discriminant (Expr : Node_Id) return Boolean;
11040 -- Returns True if Expr is a discriminant
11042 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
11043 -- Find the value of discriminant Discrim in Constraint
11045 -----------------------------------
11046 -- Build_Constrained_Access_Type --
11047 -----------------------------------
11049 function Build_Constrained_Access_Type
11050 (Old_Type : Entity_Id) return Entity_Id
11052 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
11054 Desig_Subtype : Entity_Id;
11058 -- if the original access type was not embedded in the enclosing
11059 -- type definition, there is no need to produce a new access
11060 -- subtype. In fact every access type with an explicit constraint
11061 -- generates an itype whose scope is the enclosing record.
11063 if not Is_Type (Scope (Old_Type)) then
11066 elsif Is_Array_Type (Desig_Type) then
11067 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
11069 elsif Has_Discriminants (Desig_Type) then
11071 -- This may be an access type to an enclosing record type for
11072 -- which we are constructing the constrained components. Return
11073 -- the enclosing record subtype. This is not always correct,
11074 -- but avoids infinite recursion. ???
11076 Desig_Subtype := Any_Type;
11078 for J in reverse 0 .. Scope_Stack.Last loop
11079 Scop := Scope_Stack.Table (J).Entity;
11082 and then Base_Type (Scop) = Base_Type (Desig_Type)
11084 Desig_Subtype := Scop;
11087 exit when not Is_Type (Scop);
11090 if Desig_Subtype = Any_Type then
11092 Build_Constrained_Discriminated_Type (Desig_Type);
11099 if Desig_Subtype /= Desig_Type then
11101 -- The Related_Node better be here or else we won't be able
11102 -- to attach new itypes to a node in the tree.
11104 pragma Assert (Present (Related_Node));
11106 Itype := Create_Itype (E_Access_Subtype, Related_Node);
11108 Set_Etype (Itype, Base_Type (Old_Type));
11109 Set_Size_Info (Itype, (Old_Type));
11110 Set_Directly_Designated_Type (Itype, Desig_Subtype);
11111 Set_Depends_On_Private (Itype, Has_Private_Component
11113 Set_Is_Access_Constant (Itype, Is_Access_Constant
11116 -- The new itype needs freezing when it depends on a not frozen
11117 -- type and the enclosing subtype needs freezing.
11119 if Has_Delayed_Freeze (Constrained_Typ)
11120 and then not Is_Frozen (Constrained_Typ)
11122 Conditional_Delay (Itype, Base_Type (Old_Type));
11130 end Build_Constrained_Access_Type;
11132 ----------------------------------
11133 -- Build_Constrained_Array_Type --
11134 ----------------------------------
11136 function Build_Constrained_Array_Type
11137 (Old_Type : Entity_Id) return Entity_Id
11141 Old_Index : Node_Id;
11142 Range_Node : Node_Id;
11143 Constr_List : List_Id;
11145 Need_To_Create_Itype : Boolean := False;
11148 Old_Index := First_Index (Old_Type);
11149 while Present (Old_Index) loop
11150 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
11152 if Is_Discriminant (Lo_Expr)
11153 or else Is_Discriminant (Hi_Expr)
11155 Need_To_Create_Itype := True;
11158 Next_Index (Old_Index);
11161 if Need_To_Create_Itype then
11162 Constr_List := New_List;
11164 Old_Index := First_Index (Old_Type);
11165 while Present (Old_Index) loop
11166 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
11168 if Is_Discriminant (Lo_Expr) then
11169 Lo_Expr := Get_Discr_Value (Lo_Expr);
11172 if Is_Discriminant (Hi_Expr) then
11173 Hi_Expr := Get_Discr_Value (Hi_Expr);
11178 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
11180 Append (Range_Node, To => Constr_List);
11182 Next_Index (Old_Index);
11185 return Build_Subtype (Old_Type, Constr_List);
11190 end Build_Constrained_Array_Type;
11192 ------------------------------------------
11193 -- Build_Constrained_Discriminated_Type --
11194 ------------------------------------------
11196 function Build_Constrained_Discriminated_Type
11197 (Old_Type : Entity_Id) return Entity_Id
11200 Constr_List : List_Id;
11201 Old_Constraint : Elmt_Id;
11203 Need_To_Create_Itype : Boolean := False;
11206 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
11207 while Present (Old_Constraint) loop
11208 Expr := Node (Old_Constraint);
11210 if Is_Discriminant (Expr) then
11211 Need_To_Create_Itype := True;
11214 Next_Elmt (Old_Constraint);
11217 if Need_To_Create_Itype then
11218 Constr_List := New_List;
11220 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
11221 while Present (Old_Constraint) loop
11222 Expr := Node (Old_Constraint);
11224 if Is_Discriminant (Expr) then
11225 Expr := Get_Discr_Value (Expr);
11228 Append (New_Copy_Tree (Expr), To => Constr_List);
11230 Next_Elmt (Old_Constraint);
11233 return Build_Subtype (Old_Type, Constr_List);
11238 end Build_Constrained_Discriminated_Type;
11240 -------------------
11241 -- Build_Subtype --
11242 -------------------
11244 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
11246 Subtyp_Decl : Node_Id;
11247 Def_Id : Entity_Id;
11248 Btyp : Entity_Id := Base_Type (T);
11251 -- The Related_Node better be here or else we won't be able to
11252 -- attach new itypes to a node in the tree.
11254 pragma Assert (Present (Related_Node));
11256 -- If the view of the component's type is incomplete or private
11257 -- with unknown discriminants, then the constraint must be applied
11258 -- to the full type.
11260 if Has_Unknown_Discriminants (Btyp)
11261 and then Present (Underlying_Type (Btyp))
11263 Btyp := Underlying_Type (Btyp);
11267 Make_Subtype_Indication (Loc,
11268 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
11269 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
11271 Def_Id := Create_Itype (Ekind (T), Related_Node);
11274 Make_Subtype_Declaration (Loc,
11275 Defining_Identifier => Def_Id,
11276 Subtype_Indication => Indic);
11278 Set_Parent (Subtyp_Decl, Parent (Related_Node));
11280 -- Itypes must be analyzed with checks off (see package Itypes)
11282 Analyze (Subtyp_Decl, Suppress => All_Checks);
11287 ---------------------
11288 -- Get_Discr_Value --
11289 ---------------------
11291 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
11296 -- The discriminant may be declared for the type, in which case we
11297 -- find it by iterating over the list of discriminants. If the
11298 -- discriminant is inherited from a parent type, it appears as the
11299 -- corresponding discriminant of the current type. This will be the
11300 -- case when constraining an inherited component whose constraint is
11301 -- given by a discriminant of the parent.
11303 D := First_Discriminant (Typ);
11304 E := First_Elmt (Constraints);
11306 while Present (D) loop
11307 if D = Entity (Discrim)
11308 or else D = CR_Discriminant (Entity (Discrim))
11309 or else Corresponding_Discriminant (D) = Entity (Discrim)
11314 Next_Discriminant (D);
11318 -- The Corresponding_Discriminant mechanism is incomplete, because
11319 -- the correspondence between new and old discriminants is not one
11320 -- to one: one new discriminant can constrain several old ones. In
11321 -- that case, scan sequentially the stored_constraint, the list of
11322 -- discriminants of the parents, and the constraints.
11323 -- Previous code checked for the present of the Stored_Constraint
11324 -- list for the derived type, but did not use it at all. Should it
11325 -- be present when the component is a discriminated task type?
11327 if Is_Derived_Type (Typ)
11328 and then Scope (Entity (Discrim)) = Etype (Typ)
11330 D := First_Discriminant (Etype (Typ));
11331 E := First_Elmt (Constraints);
11332 while Present (D) loop
11333 if D = Entity (Discrim) then
11337 Next_Discriminant (D);
11342 -- Something is wrong if we did not find the value
11344 raise Program_Error;
11345 end Get_Discr_Value;
11347 ---------------------
11348 -- Is_Discriminant --
11349 ---------------------
11351 function Is_Discriminant (Expr : Node_Id) return Boolean is
11352 Discrim_Scope : Entity_Id;
11355 if Denotes_Discriminant (Expr) then
11356 Discrim_Scope := Scope (Entity (Expr));
11358 -- Either we have a reference to one of Typ's discriminants,
11360 pragma Assert (Discrim_Scope = Typ
11362 -- or to the discriminants of the parent type, in the case
11363 -- of a derivation of a tagged type with variants.
11365 or else Discrim_Scope = Etype (Typ)
11366 or else Full_View (Discrim_Scope) = Etype (Typ)
11368 -- or same as above for the case where the discriminants
11369 -- were declared in Typ's private view.
11371 or else (Is_Private_Type (Discrim_Scope)
11372 and then Chars (Discrim_Scope) = Chars (Typ))
11374 -- or else we are deriving from the full view and the
11375 -- discriminant is declared in the private entity.
11377 or else (Is_Private_Type (Typ)
11378 and then Chars (Discrim_Scope) = Chars (Typ))
11380 -- Or we are constrained the corresponding record of a
11381 -- synchronized type that completes a private declaration.
11383 or else (Is_Concurrent_Record_Type (Typ)
11385 Corresponding_Concurrent_Type (Typ) = Discrim_Scope)
11387 -- or we have a class-wide type, in which case make sure the
11388 -- discriminant found belongs to the root type.
11390 or else (Is_Class_Wide_Type (Typ)
11391 and then Etype (Typ) = Discrim_Scope));
11396 -- In all other cases we have something wrong
11399 end Is_Discriminant;
11401 -- Start of processing for Constrain_Component_Type
11404 if Nkind (Parent (Comp)) = N_Component_Declaration
11405 and then Comes_From_Source (Parent (Comp))
11406 and then Comes_From_Source
11407 (Subtype_Indication (Component_Definition (Parent (Comp))))
11410 (Subtype_Indication (Component_Definition (Parent (Comp))))
11412 return Compon_Type;
11414 elsif Is_Array_Type (Compon_Type) then
11415 return Build_Constrained_Array_Type (Compon_Type);
11417 elsif Has_Discriminants (Compon_Type) then
11418 return Build_Constrained_Discriminated_Type (Compon_Type);
11420 elsif Is_Access_Type (Compon_Type) then
11421 return Build_Constrained_Access_Type (Compon_Type);
11424 return Compon_Type;
11426 end Constrain_Component_Type;
11428 --------------------------
11429 -- Constrain_Concurrent --
11430 --------------------------
11432 -- For concurrent types, the associated record value type carries the same
11433 -- discriminants, so when we constrain a concurrent type, we must constrain
11434 -- the corresponding record type as well.
11436 procedure Constrain_Concurrent
11437 (Def_Id : in out Entity_Id;
11439 Related_Nod : Node_Id;
11440 Related_Id : Entity_Id;
11441 Suffix : Character)
11443 -- Retrieve Base_Type to ensure getting to the concurrent type in the
11444 -- case of a private subtype (needed when only doing semantic analysis).
11446 T_Ent : Entity_Id := Base_Type (Entity (Subtype_Mark (SI)));
11450 if Ekind (T_Ent) in Access_Kind then
11451 T_Ent := Designated_Type (T_Ent);
11454 T_Val := Corresponding_Record_Type (T_Ent);
11456 if Present (T_Val) then
11458 if No (Def_Id) then
11459 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11462 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
11464 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
11465 Set_Corresponding_Record_Type (Def_Id,
11466 Constrain_Corresponding_Record
11467 (Def_Id, T_Val, Related_Nod, Related_Id));
11470 -- If there is no associated record, expansion is disabled and this
11471 -- is a generic context. Create a subtype in any case, so that
11472 -- semantic analysis can proceed.
11474 if No (Def_Id) then
11475 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11478 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
11480 end Constrain_Concurrent;
11482 ------------------------------------
11483 -- Constrain_Corresponding_Record --
11484 ------------------------------------
11486 function Constrain_Corresponding_Record
11487 (Prot_Subt : Entity_Id;
11488 Corr_Rec : Entity_Id;
11489 Related_Nod : Node_Id;
11490 Related_Id : Entity_Id) return Entity_Id
11492 T_Sub : constant Entity_Id :=
11493 Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
11496 Set_Etype (T_Sub, Corr_Rec);
11497 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
11498 Set_Is_Constrained (T_Sub, True);
11499 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
11500 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
11502 -- As elsewhere, we do not want to create a freeze node for this itype
11503 -- if it is created for a constrained component of an enclosing record
11504 -- because references to outer discriminants will appear out of scope.
11506 if Ekind (Scope (Prot_Subt)) /= E_Record_Type then
11507 Conditional_Delay (T_Sub, Corr_Rec);
11509 Set_Is_Frozen (T_Sub);
11512 if Has_Discriminants (Prot_Subt) then -- False only if errors.
11513 Set_Discriminant_Constraint
11514 (T_Sub, Discriminant_Constraint (Prot_Subt));
11515 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
11516 Create_Constrained_Components
11517 (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
11520 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
11523 end Constrain_Corresponding_Record;
11525 -----------------------
11526 -- Constrain_Decimal --
11527 -----------------------
11529 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
11530 T : constant Entity_Id := Entity (Subtype_Mark (S));
11531 C : constant Node_Id := Constraint (S);
11532 Loc : constant Source_Ptr := Sloc (C);
11533 Range_Expr : Node_Id;
11534 Digits_Expr : Node_Id;
11539 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
11541 if Nkind (C) = N_Range_Constraint then
11542 Range_Expr := Range_Expression (C);
11543 Digits_Val := Digits_Value (T);
11546 pragma Assert (Nkind (C) = N_Digits_Constraint);
11548 Check_SPARK_Restriction ("digits constraint is not allowed", S);
11550 Digits_Expr := Digits_Expression (C);
11551 Analyze_And_Resolve (Digits_Expr, Any_Integer);
11553 Check_Digits_Expression (Digits_Expr);
11554 Digits_Val := Expr_Value (Digits_Expr);
11556 if Digits_Val > Digits_Value (T) then
11558 ("digits expression is incompatible with subtype", C);
11559 Digits_Val := Digits_Value (T);
11562 if Present (Range_Constraint (C)) then
11563 Range_Expr := Range_Expression (Range_Constraint (C));
11565 Range_Expr := Empty;
11569 Set_Etype (Def_Id, Base_Type (T));
11570 Set_Size_Info (Def_Id, (T));
11571 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11572 Set_Delta_Value (Def_Id, Delta_Value (T));
11573 Set_Scale_Value (Def_Id, Scale_Value (T));
11574 Set_Small_Value (Def_Id, Small_Value (T));
11575 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
11576 Set_Digits_Value (Def_Id, Digits_Val);
11578 -- Manufacture range from given digits value if no range present
11580 if No (Range_Expr) then
11581 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
11585 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
11587 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
11590 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
11591 Set_Discrete_RM_Size (Def_Id);
11593 -- Unconditionally delay the freeze, since we cannot set size
11594 -- information in all cases correctly until the freeze point.
11596 Set_Has_Delayed_Freeze (Def_Id);
11597 end Constrain_Decimal;
11599 ----------------------------------
11600 -- Constrain_Discriminated_Type --
11601 ----------------------------------
11603 procedure Constrain_Discriminated_Type
11604 (Def_Id : Entity_Id;
11606 Related_Nod : Node_Id;
11607 For_Access : Boolean := False)
11609 E : constant Entity_Id := Entity (Subtype_Mark (S));
11612 Elist : Elist_Id := New_Elmt_List;
11614 procedure Fixup_Bad_Constraint;
11615 -- This is called after finding a bad constraint, and after having
11616 -- posted an appropriate error message. The mission is to leave the
11617 -- entity T in as reasonable state as possible!
11619 --------------------------
11620 -- Fixup_Bad_Constraint --
11621 --------------------------
11623 procedure Fixup_Bad_Constraint is
11625 -- Set a reasonable Ekind for the entity. For an incomplete type,
11626 -- we can't do much, but for other types, we can set the proper
11627 -- corresponding subtype kind.
11629 if Ekind (T) = E_Incomplete_Type then
11630 Set_Ekind (Def_Id, Ekind (T));
11632 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
11635 -- Set Etype to the known type, to reduce chances of cascaded errors
11637 Set_Etype (Def_Id, E);
11638 Set_Error_Posted (Def_Id);
11639 end Fixup_Bad_Constraint;
11641 -- Start of processing for Constrain_Discriminated_Type
11644 C := Constraint (S);
11646 -- A discriminant constraint is only allowed in a subtype indication,
11647 -- after a subtype mark. This subtype mark must denote either a type
11648 -- with discriminants, or an access type whose designated type is a
11649 -- type with discriminants. A discriminant constraint specifies the
11650 -- values of these discriminants (RM 3.7.2(5)).
11652 T := Base_Type (Entity (Subtype_Mark (S)));
11654 if Ekind (T) in Access_Kind then
11655 T := Designated_Type (T);
11658 -- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal.
11659 -- Avoid generating an error for access-to-incomplete subtypes.
11661 if Ada_Version >= Ada_2005
11662 and then Ekind (T) = E_Incomplete_Type
11663 and then Nkind (Parent (S)) = N_Subtype_Declaration
11664 and then not Is_Itype (Def_Id)
11666 -- A little sanity check, emit an error message if the type
11667 -- has discriminants to begin with. Type T may be a regular
11668 -- incomplete type or imported via a limited with clause.
11670 if Has_Discriminants (T)
11672 (From_With_Type (T)
11673 and then Present (Non_Limited_View (T))
11674 and then Nkind (Parent (Non_Limited_View (T))) =
11675 N_Full_Type_Declaration
11676 and then Present (Discriminant_Specifications
11677 (Parent (Non_Limited_View (T)))))
11680 ("(Ada 2005) incomplete subtype may not be constrained", C);
11682 Error_Msg_N ("invalid constraint: type has no discriminant", C);
11685 Fixup_Bad_Constraint;
11688 -- Check that the type has visible discriminants. The type may be
11689 -- a private type with unknown discriminants whose full view has
11690 -- discriminants which are invisible.
11692 elsif not Has_Discriminants (T)
11694 (Has_Unknown_Discriminants (T)
11695 and then Is_Private_Type (T))
11697 Error_Msg_N ("invalid constraint: type has no discriminant", C);
11698 Fixup_Bad_Constraint;
11701 elsif Is_Constrained (E)
11702 or else (Ekind (E) = E_Class_Wide_Subtype
11703 and then Present (Discriminant_Constraint (E)))
11705 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
11706 Fixup_Bad_Constraint;
11710 -- T may be an unconstrained subtype (e.g. a generic actual).
11711 -- Constraint applies to the base type.
11713 T := Base_Type (T);
11715 Elist := Build_Discriminant_Constraints (T, S);
11717 -- If the list returned was empty we had an error in building the
11718 -- discriminant constraint. We have also already signalled an error
11719 -- in the incomplete type case
11721 if Is_Empty_Elmt_List (Elist) then
11722 Fixup_Bad_Constraint;
11726 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
11727 end Constrain_Discriminated_Type;
11729 ---------------------------
11730 -- Constrain_Enumeration --
11731 ---------------------------
11733 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
11734 T : constant Entity_Id := Entity (Subtype_Mark (S));
11735 C : constant Node_Id := Constraint (S);
11738 Set_Ekind (Def_Id, E_Enumeration_Subtype);
11740 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
11742 Set_Etype (Def_Id, Base_Type (T));
11743 Set_Size_Info (Def_Id, (T));
11744 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11745 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
11747 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
11749 Set_Discrete_RM_Size (Def_Id);
11750 end Constrain_Enumeration;
11752 ----------------------
11753 -- Constrain_Float --
11754 ----------------------
11756 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
11757 T : constant Entity_Id := Entity (Subtype_Mark (S));
11763 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
11765 Set_Etype (Def_Id, Base_Type (T));
11766 Set_Size_Info (Def_Id, (T));
11767 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11769 -- Process the constraint
11771 C := Constraint (S);
11773 -- Digits constraint present
11775 if Nkind (C) = N_Digits_Constraint then
11777 Check_SPARK_Restriction ("digits constraint is not allowed", S);
11778 Check_Restriction (No_Obsolescent_Features, C);
11780 if Warn_On_Obsolescent_Feature then
11782 ("subtype digits constraint is an " &
11783 "obsolescent feature (RM J.3(8))?", C);
11786 D := Digits_Expression (C);
11787 Analyze_And_Resolve (D, Any_Integer);
11788 Check_Digits_Expression (D);
11789 Set_Digits_Value (Def_Id, Expr_Value (D));
11791 -- Check that digits value is in range. Obviously we can do this
11792 -- at compile time, but it is strictly a runtime check, and of
11793 -- course there is an ACVC test that checks this!
11795 if Digits_Value (Def_Id) > Digits_Value (T) then
11796 Error_Msg_Uint_1 := Digits_Value (T);
11797 Error_Msg_N ("?digits value is too large, maximum is ^", D);
11799 Make_Raise_Constraint_Error (Sloc (D),
11800 Reason => CE_Range_Check_Failed);
11801 Insert_Action (Declaration_Node (Def_Id), Rais);
11804 C := Range_Constraint (C);
11806 -- No digits constraint present
11809 Set_Digits_Value (Def_Id, Digits_Value (T));
11812 -- Range constraint present
11814 if Nkind (C) = N_Range_Constraint then
11815 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
11817 -- No range constraint present
11820 pragma Assert (No (C));
11821 Set_Scalar_Range (Def_Id, Scalar_Range (T));
11824 Set_Is_Constrained (Def_Id);
11825 end Constrain_Float;
11827 ---------------------
11828 -- Constrain_Index --
11829 ---------------------
11831 procedure Constrain_Index
11834 Related_Nod : Node_Id;
11835 Related_Id : Entity_Id;
11836 Suffix : Character;
11837 Suffix_Index : Nat)
11839 Def_Id : Entity_Id;
11840 R : Node_Id := Empty;
11841 T : constant Entity_Id := Etype (Index);
11844 if Nkind (S) = N_Range
11846 (Nkind (S) = N_Attribute_Reference
11847 and then Attribute_Name (S) = Name_Range)
11849 -- A Range attribute will be transformed into N_Range by Resolve
11855 Process_Range_Expr_In_Decl (R, T, Empty_List);
11857 if not Error_Posted (S)
11859 (Nkind (S) /= N_Range
11860 or else not Covers (T, (Etype (Low_Bound (S))))
11861 or else not Covers (T, (Etype (High_Bound (S)))))
11863 if Base_Type (T) /= Any_Type
11864 and then Etype (Low_Bound (S)) /= Any_Type
11865 and then Etype (High_Bound (S)) /= Any_Type
11867 Error_Msg_N ("range expected", S);
11871 elsif Nkind (S) = N_Subtype_Indication then
11873 -- The parser has verified that this is a discrete indication
11875 Resolve_Discrete_Subtype_Indication (S, T);
11876 R := Range_Expression (Constraint (S));
11878 -- Capture values of bounds and generate temporaries for them if
11879 -- needed, since checks may cause duplication of the expressions
11880 -- which must not be reevaluated.
11882 -- The forced evaluation removes side effects from expressions,
11883 -- which should occur also in Alfa mode. Otherwise, we end up with
11884 -- unexpected insertions of actions at places where this is not
11885 -- supposed to occur, e.g. on default parameters of a call.
11887 if Expander_Active then
11888 Force_Evaluation (Low_Bound (R));
11889 Force_Evaluation (High_Bound (R));
11892 elsif Nkind (S) = N_Discriminant_Association then
11894 -- Syntactically valid in subtype indication
11896 Error_Msg_N ("invalid index constraint", S);
11897 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
11900 -- Subtype_Mark case, no anonymous subtypes to construct
11905 if Is_Entity_Name (S) then
11906 if not Is_Type (Entity (S)) then
11907 Error_Msg_N ("expect subtype mark for index constraint", S);
11909 elsif Base_Type (Entity (S)) /= Base_Type (T) then
11910 Wrong_Type (S, Base_Type (T));
11912 -- Check error of subtype with predicate in index constraint
11915 Bad_Predicated_Subtype_Use
11916 ("subtype& has predicate, not allowed in index constraint",
11923 Error_Msg_N ("invalid index constraint", S);
11924 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
11930 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
11932 Set_Etype (Def_Id, Base_Type (T));
11934 if Is_Modular_Integer_Type (T) then
11935 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
11937 elsif Is_Integer_Type (T) then
11938 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
11941 Set_Ekind (Def_Id, E_Enumeration_Subtype);
11942 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
11943 Set_First_Literal (Def_Id, First_Literal (T));
11946 Set_Size_Info (Def_Id, (T));
11947 Set_RM_Size (Def_Id, RM_Size (T));
11948 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11950 Set_Scalar_Range (Def_Id, R);
11952 Set_Etype (S, Def_Id);
11953 Set_Discrete_RM_Size (Def_Id);
11954 end Constrain_Index;
11956 -----------------------
11957 -- Constrain_Integer --
11958 -----------------------
11960 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
11961 T : constant Entity_Id := Entity (Subtype_Mark (S));
11962 C : constant Node_Id := Constraint (S);
11965 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
11967 if Is_Modular_Integer_Type (T) then
11968 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
11970 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
11973 Set_Etype (Def_Id, Base_Type (T));
11974 Set_Size_Info (Def_Id, (T));
11975 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11976 Set_Discrete_RM_Size (Def_Id);
11977 end Constrain_Integer;
11979 ------------------------------
11980 -- Constrain_Ordinary_Fixed --
11981 ------------------------------
11983 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
11984 T : constant Entity_Id := Entity (Subtype_Mark (S));
11990 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
11991 Set_Etype (Def_Id, Base_Type (T));
11992 Set_Size_Info (Def_Id, (T));
11993 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11994 Set_Small_Value (Def_Id, Small_Value (T));
11996 -- Process the constraint
11998 C := Constraint (S);
12000 -- Delta constraint present
12002 if Nkind (C) = N_Delta_Constraint then
12004 Check_SPARK_Restriction ("delta constraint is not allowed", S);
12005 Check_Restriction (No_Obsolescent_Features, C);
12007 if Warn_On_Obsolescent_Feature then
12009 ("subtype delta constraint is an " &
12010 "obsolescent feature (RM J.3(7))?");
12013 D := Delta_Expression (C);
12014 Analyze_And_Resolve (D, Any_Real);
12015 Check_Delta_Expression (D);
12016 Set_Delta_Value (Def_Id, Expr_Value_R (D));
12018 -- Check that delta value is in range. Obviously we can do this
12019 -- at compile time, but it is strictly a runtime check, and of
12020 -- course there is an ACVC test that checks this!
12022 if Delta_Value (Def_Id) < Delta_Value (T) then
12023 Error_Msg_N ("?delta value is too small", D);
12025 Make_Raise_Constraint_Error (Sloc (D),
12026 Reason => CE_Range_Check_Failed);
12027 Insert_Action (Declaration_Node (Def_Id), Rais);
12030 C := Range_Constraint (C);
12032 -- No delta constraint present
12035 Set_Delta_Value (Def_Id, Delta_Value (T));
12038 -- Range constraint present
12040 if Nkind (C) = N_Range_Constraint then
12041 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
12043 -- No range constraint present
12046 pragma Assert (No (C));
12047 Set_Scalar_Range (Def_Id, Scalar_Range (T));
12051 Set_Discrete_RM_Size (Def_Id);
12053 -- Unconditionally delay the freeze, since we cannot set size
12054 -- information in all cases correctly until the freeze point.
12056 Set_Has_Delayed_Freeze (Def_Id);
12057 end Constrain_Ordinary_Fixed;
12059 -----------------------
12060 -- Contain_Interface --
12061 -----------------------
12063 function Contain_Interface
12064 (Iface : Entity_Id;
12065 Ifaces : Elist_Id) return Boolean
12067 Iface_Elmt : Elmt_Id;
12070 if Present (Ifaces) then
12071 Iface_Elmt := First_Elmt (Ifaces);
12072 while Present (Iface_Elmt) loop
12073 if Node (Iface_Elmt) = Iface then
12077 Next_Elmt (Iface_Elmt);
12082 end Contain_Interface;
12084 ---------------------------
12085 -- Convert_Scalar_Bounds --
12086 ---------------------------
12088 procedure Convert_Scalar_Bounds
12090 Parent_Type : Entity_Id;
12091 Derived_Type : Entity_Id;
12094 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
12101 -- Defend against previous errors
12103 if No (Scalar_Range (Derived_Type)) then
12107 Lo := Build_Scalar_Bound
12108 (Type_Low_Bound (Derived_Type),
12109 Parent_Type, Implicit_Base);
12111 Hi := Build_Scalar_Bound
12112 (Type_High_Bound (Derived_Type),
12113 Parent_Type, Implicit_Base);
12120 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
12122 Set_Parent (Rng, N);
12123 Set_Scalar_Range (Derived_Type, Rng);
12125 -- Analyze the bounds
12127 Analyze_And_Resolve (Lo, Implicit_Base);
12128 Analyze_And_Resolve (Hi, Implicit_Base);
12130 -- Analyze the range itself, except that we do not analyze it if
12131 -- the bounds are real literals, and we have a fixed-point type.
12132 -- The reason for this is that we delay setting the bounds in this
12133 -- case till we know the final Small and Size values (see circuit
12134 -- in Freeze.Freeze_Fixed_Point_Type for further details).
12136 if Is_Fixed_Point_Type (Parent_Type)
12137 and then Nkind (Lo) = N_Real_Literal
12138 and then Nkind (Hi) = N_Real_Literal
12142 -- Here we do the analysis of the range
12144 -- Note: we do this manually, since if we do a normal Analyze and
12145 -- Resolve call, there are problems with the conversions used for
12146 -- the derived type range.
12149 Set_Etype (Rng, Implicit_Base);
12150 Set_Analyzed (Rng, True);
12152 end Convert_Scalar_Bounds;
12154 -------------------
12155 -- Copy_And_Swap --
12156 -------------------
12158 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
12160 -- Initialize new full declaration entity by copying the pertinent
12161 -- fields of the corresponding private declaration entity.
12163 -- We temporarily set Ekind to a value appropriate for a type to
12164 -- avoid assert failures in Einfo from checking for setting type
12165 -- attributes on something that is not a type. Ekind (Priv) is an
12166 -- appropriate choice, since it allowed the attributes to be set
12167 -- in the first place. This Ekind value will be modified later.
12169 Set_Ekind (Full, Ekind (Priv));
12171 -- Also set Etype temporarily to Any_Type, again, in the absence
12172 -- of errors, it will be properly reset, and if there are errors,
12173 -- then we want a value of Any_Type to remain.
12175 Set_Etype (Full, Any_Type);
12177 -- Now start copying attributes
12179 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
12181 if Has_Discriminants (Full) then
12182 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
12183 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
12186 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
12187 Set_Homonym (Full, Homonym (Priv));
12188 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
12189 Set_Is_Public (Full, Is_Public (Priv));
12190 Set_Is_Pure (Full, Is_Pure (Priv));
12191 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
12192 Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv));
12193 Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv));
12194 Set_Has_Pragma_Unreferenced_Objects
12195 (Full, Has_Pragma_Unreferenced_Objects
12198 Conditional_Delay (Full, Priv);
12200 if Is_Tagged_Type (Full) then
12201 Set_Direct_Primitive_Operations (Full,
12202 Direct_Primitive_Operations (Priv));
12204 if Is_Base_Type (Priv) then
12205 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
12209 Set_Is_Volatile (Full, Is_Volatile (Priv));
12210 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
12211 Set_Scope (Full, Scope (Priv));
12212 Set_Next_Entity (Full, Next_Entity (Priv));
12213 Set_First_Entity (Full, First_Entity (Priv));
12214 Set_Last_Entity (Full, Last_Entity (Priv));
12216 -- If access types have been recorded for later handling, keep them in
12217 -- the full view so that they get handled when the full view freeze
12218 -- node is expanded.
12220 if Present (Freeze_Node (Priv))
12221 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
12223 Ensure_Freeze_Node (Full);
12224 Set_Access_Types_To_Process
12225 (Freeze_Node (Full),
12226 Access_Types_To_Process (Freeze_Node (Priv)));
12229 -- Swap the two entities. Now Private is the full type entity and Full
12230 -- is the private one. They will be swapped back at the end of the
12231 -- private part. This swapping ensures that the entity that is visible
12232 -- in the private part is the full declaration.
12234 Exchange_Entities (Priv, Full);
12235 Append_Entity (Full, Scope (Full));
12238 -------------------------------------
12239 -- Copy_Array_Base_Type_Attributes --
12240 -------------------------------------
12242 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
12244 Set_Component_Alignment (T1, Component_Alignment (T2));
12245 Set_Component_Type (T1, Component_Type (T2));
12246 Set_Component_Size (T1, Component_Size (T2));
12247 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
12248 Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
12249 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
12250 Set_Has_Task (T1, Has_Task (T2));
12251 Set_Is_Packed (T1, Is_Packed (T2));
12252 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
12253 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
12254 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
12255 end Copy_Array_Base_Type_Attributes;
12257 -----------------------------------
12258 -- Copy_Array_Subtype_Attributes --
12259 -----------------------------------
12261 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
12263 Set_Size_Info (T1, T2);
12265 Set_First_Index (T1, First_Index (T2));
12266 Set_Is_Aliased (T1, Is_Aliased (T2));
12267 Set_Is_Atomic (T1, Is_Atomic (T2));
12268 Set_Is_Volatile (T1, Is_Volatile (T2));
12269 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
12270 Set_Is_Constrained (T1, Is_Constrained (T2));
12271 Set_Depends_On_Private (T1, Has_Private_Component (T2));
12272 Set_First_Rep_Item (T1, First_Rep_Item (T2));
12273 Set_Convention (T1, Convention (T2));
12274 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
12275 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
12276 Set_Packed_Array_Type (T1, Packed_Array_Type (T2));
12277 end Copy_Array_Subtype_Attributes;
12279 -----------------------------------
12280 -- Create_Constrained_Components --
12281 -----------------------------------
12283 procedure Create_Constrained_Components
12285 Decl_Node : Node_Id;
12287 Constraints : Elist_Id)
12289 Loc : constant Source_Ptr := Sloc (Subt);
12290 Comp_List : constant Elist_Id := New_Elmt_List;
12291 Parent_Type : constant Entity_Id := Etype (Typ);
12292 Assoc_List : constant List_Id := New_List;
12293 Discr_Val : Elmt_Id;
12297 Is_Static : Boolean := True;
12299 procedure Collect_Fixed_Components (Typ : Entity_Id);
12300 -- Collect parent type components that do not appear in a variant part
12302 procedure Create_All_Components;
12303 -- Iterate over Comp_List to create the components of the subtype
12305 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
12306 -- Creates a new component from Old_Compon, copying all the fields from
12307 -- it, including its Etype, inserts the new component in the Subt entity
12308 -- chain and returns the new component.
12310 function Is_Variant_Record (T : Entity_Id) return Boolean;
12311 -- If true, and discriminants are static, collect only components from
12312 -- variants selected by discriminant values.
12314 ------------------------------
12315 -- Collect_Fixed_Components --
12316 ------------------------------
12318 procedure Collect_Fixed_Components (Typ : Entity_Id) is
12320 -- Build association list for discriminants, and find components of the
12321 -- variant part selected by the values of the discriminants.
12323 Old_C := First_Discriminant (Typ);
12324 Discr_Val := First_Elmt (Constraints);
12325 while Present (Old_C) loop
12326 Append_To (Assoc_List,
12327 Make_Component_Association (Loc,
12328 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
12329 Expression => New_Copy (Node (Discr_Val))));
12331 Next_Elmt (Discr_Val);
12332 Next_Discriminant (Old_C);
12335 -- The tag and the possible parent component are unconditionally in
12338 if Is_Tagged_Type (Typ)
12339 or else Has_Controlled_Component (Typ)
12341 Old_C := First_Component (Typ);
12342 while Present (Old_C) loop
12343 if Chars ((Old_C)) = Name_uTag
12344 or else Chars ((Old_C)) = Name_uParent
12346 Append_Elmt (Old_C, Comp_List);
12349 Next_Component (Old_C);
12352 end Collect_Fixed_Components;
12354 ---------------------------
12355 -- Create_All_Components --
12356 ---------------------------
12358 procedure Create_All_Components is
12362 Comp := First_Elmt (Comp_List);
12363 while Present (Comp) loop
12364 Old_C := Node (Comp);
12365 New_C := Create_Component (Old_C);
12369 Constrain_Component_Type
12370 (Old_C, Subt, Decl_Node, Typ, Constraints));
12371 Set_Is_Public (New_C, Is_Public (Subt));
12375 end Create_All_Components;
12377 ----------------------
12378 -- Create_Component --
12379 ----------------------
12381 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
12382 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
12385 if Ekind (Old_Compon) = E_Discriminant
12386 and then Is_Completely_Hidden (Old_Compon)
12388 -- This is a shadow discriminant created for a discriminant of
12389 -- the parent type, which needs to be present in the subtype.
12390 -- Give the shadow discriminant an internal name that cannot
12391 -- conflict with that of visible components.
12393 Set_Chars (New_Compon, New_Internal_Name ('C'));
12396 -- Set the parent so we have a proper link for freezing etc. This is
12397 -- not a real parent pointer, since of course our parent does not own
12398 -- up to us and reference us, we are an illegitimate child of the
12399 -- original parent!
12401 Set_Parent (New_Compon, Parent (Old_Compon));
12403 -- If the old component's Esize was already determined and is a
12404 -- static value, then the new component simply inherits it. Otherwise
12405 -- the old component's size may require run-time determination, but
12406 -- the new component's size still might be statically determinable
12407 -- (if, for example it has a static constraint). In that case we want
12408 -- Layout_Type to recompute the component's size, so we reset its
12409 -- size and positional fields.
12411 if Frontend_Layout_On_Target
12412 and then not Known_Static_Esize (Old_Compon)
12414 Set_Esize (New_Compon, Uint_0);
12415 Init_Normalized_First_Bit (New_Compon);
12416 Init_Normalized_Position (New_Compon);
12417 Init_Normalized_Position_Max (New_Compon);
12420 -- We do not want this node marked as Comes_From_Source, since
12421 -- otherwise it would get first class status and a separate cross-
12422 -- reference line would be generated. Illegitimate children do not
12423 -- rate such recognition.
12425 Set_Comes_From_Source (New_Compon, False);
12427 -- But it is a real entity, and a birth certificate must be properly
12428 -- registered by entering it into the entity list.
12430 Enter_Name (New_Compon);
12433 end Create_Component;
12435 -----------------------
12436 -- Is_Variant_Record --
12437 -----------------------
12439 function Is_Variant_Record (T : Entity_Id) return Boolean is
12441 return Nkind (Parent (T)) = N_Full_Type_Declaration
12442 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
12443 and then Present (Component_List (Type_Definition (Parent (T))))
12446 (Variant_Part (Component_List (Type_Definition (Parent (T)))));
12447 end Is_Variant_Record;
12449 -- Start of processing for Create_Constrained_Components
12452 pragma Assert (Subt /= Base_Type (Subt));
12453 pragma Assert (Typ = Base_Type (Typ));
12455 Set_First_Entity (Subt, Empty);
12456 Set_Last_Entity (Subt, Empty);
12458 -- Check whether constraint is fully static, in which case we can
12459 -- optimize the list of components.
12461 Discr_Val := First_Elmt (Constraints);
12462 while Present (Discr_Val) loop
12463 if not Is_OK_Static_Expression (Node (Discr_Val)) then
12464 Is_Static := False;
12468 Next_Elmt (Discr_Val);
12471 Set_Has_Static_Discriminants (Subt, Is_Static);
12475 -- Inherit the discriminants of the parent type
12477 Add_Discriminants : declare
12483 Old_C := First_Discriminant (Typ);
12485 while Present (Old_C) loop
12486 Num_Disc := Num_Disc + 1;
12487 New_C := Create_Component (Old_C);
12488 Set_Is_Public (New_C, Is_Public (Subt));
12489 Next_Discriminant (Old_C);
12492 -- For an untagged derived subtype, the number of discriminants may
12493 -- be smaller than the number of inherited discriminants, because
12494 -- several of them may be renamed by a single new discriminant or
12495 -- constrained. In this case, add the hidden discriminants back into
12496 -- the subtype, because they need to be present if the optimizer of
12497 -- the GCC 4.x back-end decides to break apart assignments between
12498 -- objects using the parent view into member-wise assignments.
12502 if Is_Derived_Type (Typ)
12503 and then not Is_Tagged_Type (Typ)
12505 Old_C := First_Stored_Discriminant (Typ);
12507 while Present (Old_C) loop
12508 Num_Gird := Num_Gird + 1;
12509 Next_Stored_Discriminant (Old_C);
12513 if Num_Gird > Num_Disc then
12515 -- Find out multiple uses of new discriminants, and add hidden
12516 -- components for the extra renamed discriminants. We recognize
12517 -- multiple uses through the Corresponding_Discriminant of a
12518 -- new discriminant: if it constrains several old discriminants,
12519 -- this field points to the last one in the parent type. The
12520 -- stored discriminants of the derived type have the same name
12521 -- as those of the parent.
12525 New_Discr : Entity_Id;
12526 Old_Discr : Entity_Id;
12529 Constr := First_Elmt (Stored_Constraint (Typ));
12530 Old_Discr := First_Stored_Discriminant (Typ);
12531 while Present (Constr) loop
12532 if Is_Entity_Name (Node (Constr))
12533 and then Ekind (Entity (Node (Constr))) = E_Discriminant
12535 New_Discr := Entity (Node (Constr));
12537 if Chars (Corresponding_Discriminant (New_Discr)) /=
12540 -- The new discriminant has been used to rename a
12541 -- subsequent old discriminant. Introduce a shadow
12542 -- component for the current old discriminant.
12544 New_C := Create_Component (Old_Discr);
12545 Set_Original_Record_Component (New_C, Old_Discr);
12549 -- The constraint has eliminated the old discriminant.
12550 -- Introduce a shadow component.
12552 New_C := Create_Component (Old_Discr);
12553 Set_Original_Record_Component (New_C, Old_Discr);
12556 Next_Elmt (Constr);
12557 Next_Stored_Discriminant (Old_Discr);
12561 end Add_Discriminants;
12564 and then Is_Variant_Record (Typ)
12566 Collect_Fixed_Components (Typ);
12568 Gather_Components (
12570 Component_List (Type_Definition (Parent (Typ))),
12571 Governed_By => Assoc_List,
12573 Report_Errors => Errors);
12574 pragma Assert (not Errors);
12576 Create_All_Components;
12578 -- If the subtype declaration is created for a tagged type derivation
12579 -- with constraints, we retrieve the record definition of the parent
12580 -- type to select the components of the proper variant.
12583 and then Is_Tagged_Type (Typ)
12584 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
12586 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
12587 and then Is_Variant_Record (Parent_Type)
12589 Collect_Fixed_Components (Typ);
12591 Gather_Components (
12593 Component_List (Type_Definition (Parent (Parent_Type))),
12594 Governed_By => Assoc_List,
12596 Report_Errors => Errors);
12597 pragma Assert (not Errors);
12599 -- If the tagged derivation has a type extension, collect all the
12600 -- new components therein.
12603 (Record_Extension_Part (Type_Definition (Parent (Typ))))
12605 Old_C := First_Component (Typ);
12606 while Present (Old_C) loop
12607 if Original_Record_Component (Old_C) = Old_C
12608 and then Chars (Old_C) /= Name_uTag
12609 and then Chars (Old_C) /= Name_uParent
12611 Append_Elmt (Old_C, Comp_List);
12614 Next_Component (Old_C);
12618 Create_All_Components;
12621 -- If discriminants are not static, or if this is a multi-level type
12622 -- extension, we have to include all components of the parent type.
12624 Old_C := First_Component (Typ);
12625 while Present (Old_C) loop
12626 New_C := Create_Component (Old_C);
12630 Constrain_Component_Type
12631 (Old_C, Subt, Decl_Node, Typ, Constraints));
12632 Set_Is_Public (New_C, Is_Public (Subt));
12634 Next_Component (Old_C);
12639 end Create_Constrained_Components;
12641 ------------------------------------------
12642 -- Decimal_Fixed_Point_Type_Declaration --
12643 ------------------------------------------
12645 procedure Decimal_Fixed_Point_Type_Declaration
12649 Loc : constant Source_Ptr := Sloc (Def);
12650 Digs_Expr : constant Node_Id := Digits_Expression (Def);
12651 Delta_Expr : constant Node_Id := Delta_Expression (Def);
12652 Implicit_Base : Entity_Id;
12659 Check_SPARK_Restriction
12660 ("decimal fixed point type is not allowed", Def);
12661 Check_Restriction (No_Fixed_Point, Def);
12663 -- Create implicit base type
12666 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
12667 Set_Etype (Implicit_Base, Implicit_Base);
12669 -- Analyze and process delta expression
12671 Analyze_And_Resolve (Delta_Expr, Universal_Real);
12673 Check_Delta_Expression (Delta_Expr);
12674 Delta_Val := Expr_Value_R (Delta_Expr);
12676 -- Check delta is power of 10, and determine scale value from it
12682 Scale_Val := Uint_0;
12685 if Val < Ureal_1 then
12686 while Val < Ureal_1 loop
12687 Val := Val * Ureal_10;
12688 Scale_Val := Scale_Val + 1;
12691 if Scale_Val > 18 then
12692 Error_Msg_N ("scale exceeds maximum value of 18", Def);
12693 Scale_Val := UI_From_Int (+18);
12697 while Val > Ureal_1 loop
12698 Val := Val / Ureal_10;
12699 Scale_Val := Scale_Val - 1;
12702 if Scale_Val < -18 then
12703 Error_Msg_N ("scale is less than minimum value of -18", Def);
12704 Scale_Val := UI_From_Int (-18);
12708 if Val /= Ureal_1 then
12709 Error_Msg_N ("delta expression must be a power of 10", Def);
12710 Delta_Val := Ureal_10 ** (-Scale_Val);
12714 -- Set delta, scale and small (small = delta for decimal type)
12716 Set_Delta_Value (Implicit_Base, Delta_Val);
12717 Set_Scale_Value (Implicit_Base, Scale_Val);
12718 Set_Small_Value (Implicit_Base, Delta_Val);
12720 -- Analyze and process digits expression
12722 Analyze_And_Resolve (Digs_Expr, Any_Integer);
12723 Check_Digits_Expression (Digs_Expr);
12724 Digs_Val := Expr_Value (Digs_Expr);
12726 if Digs_Val > 18 then
12727 Digs_Val := UI_From_Int (+18);
12728 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
12731 Set_Digits_Value (Implicit_Base, Digs_Val);
12732 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
12734 -- Set range of base type from digits value for now. This will be
12735 -- expanded to represent the true underlying base range by Freeze.
12737 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
12739 -- Note: We leave size as zero for now, size will be set at freeze
12740 -- time. We have to do this for ordinary fixed-point, because the size
12741 -- depends on the specified small, and we might as well do the same for
12742 -- decimal fixed-point.
12744 pragma Assert (Esize (Implicit_Base) = Uint_0);
12746 -- If there are bounds given in the declaration use them as the
12747 -- bounds of the first named subtype.
12749 if Present (Real_Range_Specification (Def)) then
12751 RRS : constant Node_Id := Real_Range_Specification (Def);
12752 Low : constant Node_Id := Low_Bound (RRS);
12753 High : constant Node_Id := High_Bound (RRS);
12758 Analyze_And_Resolve (Low, Any_Real);
12759 Analyze_And_Resolve (High, Any_Real);
12760 Check_Real_Bound (Low);
12761 Check_Real_Bound (High);
12762 Low_Val := Expr_Value_R (Low);
12763 High_Val := Expr_Value_R (High);
12765 if Low_Val < (-Bound_Val) then
12767 ("range low bound too small for digits value", Low);
12768 Low_Val := -Bound_Val;
12771 if High_Val > Bound_Val then
12773 ("range high bound too large for digits value", High);
12774 High_Val := Bound_Val;
12777 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
12780 -- If no explicit range, use range that corresponds to given
12781 -- digits value. This will end up as the final range for the
12785 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
12788 -- Complete entity for first subtype
12790 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
12791 Set_Etype (T, Implicit_Base);
12792 Set_Size_Info (T, Implicit_Base);
12793 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
12794 Set_Digits_Value (T, Digs_Val);
12795 Set_Delta_Value (T, Delta_Val);
12796 Set_Small_Value (T, Delta_Val);
12797 Set_Scale_Value (T, Scale_Val);
12798 Set_Is_Constrained (T);
12799 end Decimal_Fixed_Point_Type_Declaration;
12801 -----------------------------------
12802 -- Derive_Progenitor_Subprograms --
12803 -----------------------------------
12805 procedure Derive_Progenitor_Subprograms
12806 (Parent_Type : Entity_Id;
12807 Tagged_Type : Entity_Id)
12812 Iface_Elmt : Elmt_Id;
12813 Iface_Subp : Entity_Id;
12814 New_Subp : Entity_Id := Empty;
12815 Prim_Elmt : Elmt_Id;
12820 pragma Assert (Ada_Version >= Ada_2005
12821 and then Is_Record_Type (Tagged_Type)
12822 and then Is_Tagged_Type (Tagged_Type)
12823 and then Has_Interfaces (Tagged_Type));
12825 -- Step 1: Transfer to the full-view primitives associated with the
12826 -- partial-view that cover interface primitives. Conceptually this
12827 -- work should be done later by Process_Full_View; done here to
12828 -- simplify its implementation at later stages. It can be safely
12829 -- done here because interfaces must be visible in the partial and
12830 -- private view (RM 7.3(7.3/2)).
12832 -- Small optimization: This work is only required if the parent is
12833 -- abstract. If the tagged type is not abstract, it cannot have
12834 -- abstract primitives (the only entities in the list of primitives of
12835 -- non-abstract tagged types that can reference abstract primitives
12836 -- through its Alias attribute are the internal entities that have
12837 -- attribute Interface_Alias, and these entities are generated later
12838 -- by Add_Internal_Interface_Entities).
12840 if In_Private_Part (Current_Scope)
12841 and then Is_Abstract_Type (Parent_Type)
12843 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
12844 while Present (Elmt) loop
12845 Subp := Node (Elmt);
12847 -- At this stage it is not possible to have entities in the list
12848 -- of primitives that have attribute Interface_Alias
12850 pragma Assert (No (Interface_Alias (Subp)));
12852 Typ := Find_Dispatching_Type (Ultimate_Alias (Subp));
12854 if Is_Interface (Typ) then
12855 E := Find_Primitive_Covering_Interface
12856 (Tagged_Type => Tagged_Type,
12857 Iface_Prim => Subp);
12860 and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ
12862 Replace_Elmt (Elmt, E);
12863 Remove_Homonym (Subp);
12871 -- Step 2: Add primitives of progenitors that are not implemented by
12872 -- parents of Tagged_Type
12874 if Present (Interfaces (Base_Type (Tagged_Type))) then
12875 Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type)));
12876 while Present (Iface_Elmt) loop
12877 Iface := Node (Iface_Elmt);
12879 Prim_Elmt := First_Elmt (Primitive_Operations (Iface));
12880 while Present (Prim_Elmt) loop
12881 Iface_Subp := Node (Prim_Elmt);
12883 -- Exclude derivation of predefined primitives except those
12884 -- that come from source, or are inherited from one that comes
12885 -- from source. Required to catch declarations of equality
12886 -- operators of interfaces. For example:
12888 -- type Iface is interface;
12889 -- function "=" (Left, Right : Iface) return Boolean;
12891 if not Is_Predefined_Dispatching_Operation (Iface_Subp)
12892 or else Comes_From_Source (Ultimate_Alias (Iface_Subp))
12894 E := Find_Primitive_Covering_Interface
12895 (Tagged_Type => Tagged_Type,
12896 Iface_Prim => Iface_Subp);
12898 -- If not found we derive a new primitive leaving its alias
12899 -- attribute referencing the interface primitive
12903 (New_Subp, Iface_Subp, Tagged_Type, Iface);
12905 -- Ada 2012 (AI05-0197): If the covering primitive's name
12906 -- differs from the name of the interface primitive then it
12907 -- is a private primitive inherited from a parent type. In
12908 -- such case, given that Tagged_Type covers the interface,
12909 -- the inherited private primitive becomes visible. For such
12910 -- purpose we add a new entity that renames the inherited
12911 -- private primitive.
12913 elsif Chars (E) /= Chars (Iface_Subp) then
12914 pragma Assert (Has_Suffix (E, 'P'));
12916 (New_Subp, Iface_Subp, Tagged_Type, Iface);
12917 Set_Alias (New_Subp, E);
12918 Set_Is_Abstract_Subprogram (New_Subp,
12919 Is_Abstract_Subprogram (E));
12921 -- Propagate to the full view interface entities associated
12922 -- with the partial view
12924 elsif In_Private_Part (Current_Scope)
12925 and then Present (Alias (E))
12926 and then Alias (E) = Iface_Subp
12928 List_Containing (Parent (E)) /=
12929 Private_Declarations
12931 (Unit_Declaration_Node (Current_Scope)))
12933 Append_Elmt (E, Primitive_Operations (Tagged_Type));
12937 Next_Elmt (Prim_Elmt);
12940 Next_Elmt (Iface_Elmt);
12943 end Derive_Progenitor_Subprograms;
12945 -----------------------
12946 -- Derive_Subprogram --
12947 -----------------------
12949 procedure Derive_Subprogram
12950 (New_Subp : in out Entity_Id;
12951 Parent_Subp : Entity_Id;
12952 Derived_Type : Entity_Id;
12953 Parent_Type : Entity_Id;
12954 Actual_Subp : Entity_Id := Empty)
12956 Formal : Entity_Id;
12957 -- Formal parameter of parent primitive operation
12959 Formal_Of_Actual : Entity_Id;
12960 -- Formal parameter of actual operation, when the derivation is to
12961 -- create a renaming for a primitive operation of an actual in an
12964 New_Formal : Entity_Id;
12965 -- Formal of inherited operation
12967 Visible_Subp : Entity_Id := Parent_Subp;
12969 function Is_Private_Overriding return Boolean;
12970 -- If Subp is a private overriding of a visible operation, the inherited
12971 -- operation derives from the overridden op (even though its body is the
12972 -- overriding one) and the inherited operation is visible now. See
12973 -- sem_disp to see the full details of the handling of the overridden
12974 -- subprogram, which is removed from the list of primitive operations of
12975 -- the type. The overridden subprogram is saved locally in Visible_Subp,
12976 -- and used to diagnose abstract operations that need overriding in the
12979 procedure Replace_Type (Id, New_Id : Entity_Id);
12980 -- When the type is an anonymous access type, create a new access type
12981 -- designating the derived type.
12983 procedure Set_Derived_Name;
12984 -- This procedure sets the appropriate Chars name for New_Subp. This
12985 -- is normally just a copy of the parent name. An exception arises for
12986 -- type support subprograms, where the name is changed to reflect the
12987 -- name of the derived type, e.g. if type foo is derived from type bar,
12988 -- then a procedure barDA is derived with a name fooDA.
12990 ---------------------------
12991 -- Is_Private_Overriding --
12992 ---------------------------
12994 function Is_Private_Overriding return Boolean is
12998 -- If the parent is not a dispatching operation there is no
12999 -- need to investigate overridings
13001 if not Is_Dispatching_Operation (Parent_Subp) then
13005 -- The visible operation that is overridden is a homonym of the
13006 -- parent subprogram. We scan the homonym chain to find the one
13007 -- whose alias is the subprogram we are deriving.
13009 Prev := Current_Entity (Parent_Subp);
13010 while Present (Prev) loop
13011 if Ekind (Prev) = Ekind (Parent_Subp)
13012 and then Alias (Prev) = Parent_Subp
13013 and then Scope (Parent_Subp) = Scope (Prev)
13014 and then not Is_Hidden (Prev)
13016 Visible_Subp := Prev;
13020 Prev := Homonym (Prev);
13024 end Is_Private_Overriding;
13030 procedure Replace_Type (Id, New_Id : Entity_Id) is
13031 Acc_Type : Entity_Id;
13032 Par : constant Node_Id := Parent (Derived_Type);
13035 -- When the type is an anonymous access type, create a new access
13036 -- type designating the derived type. This itype must be elaborated
13037 -- at the point of the derivation, not on subsequent calls that may
13038 -- be out of the proper scope for Gigi, so we insert a reference to
13039 -- it after the derivation.
13041 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
13043 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
13046 if Ekind (Desig_Typ) = E_Record_Type_With_Private
13047 and then Present (Full_View (Desig_Typ))
13048 and then not Is_Private_Type (Parent_Type)
13050 Desig_Typ := Full_View (Desig_Typ);
13053 if Base_Type (Desig_Typ) = Base_Type (Parent_Type)
13055 -- Ada 2005 (AI-251): Handle also derivations of abstract
13056 -- interface primitives.
13058 or else (Is_Interface (Desig_Typ)
13059 and then not Is_Class_Wide_Type (Desig_Typ))
13061 Acc_Type := New_Copy (Etype (Id));
13062 Set_Etype (Acc_Type, Acc_Type);
13063 Set_Scope (Acc_Type, New_Subp);
13065 -- Compute size of anonymous access type
13067 if Is_Array_Type (Desig_Typ)
13068 and then not Is_Constrained (Desig_Typ)
13070 Init_Size (Acc_Type, 2 * System_Address_Size);
13072 Init_Size (Acc_Type, System_Address_Size);
13075 Init_Alignment (Acc_Type);
13076 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
13078 Set_Etype (New_Id, Acc_Type);
13079 Set_Scope (New_Id, New_Subp);
13081 -- Create a reference to it
13082 Build_Itype_Reference (Acc_Type, Parent (Derived_Type));
13085 Set_Etype (New_Id, Etype (Id));
13089 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
13091 (Ekind (Etype (Id)) = E_Record_Type_With_Private
13092 and then Present (Full_View (Etype (Id)))
13094 Base_Type (Full_View (Etype (Id))) = Base_Type (Parent_Type))
13096 -- Constraint checks on formals are generated during expansion,
13097 -- based on the signature of the original subprogram. The bounds
13098 -- of the derived type are not relevant, and thus we can use
13099 -- the base type for the formals. However, the return type may be
13100 -- used in a context that requires that the proper static bounds
13101 -- be used (a case statement, for example) and for those cases
13102 -- we must use the derived type (first subtype), not its base.
13104 -- If the derived_type_definition has no constraints, we know that
13105 -- the derived type has the same constraints as the first subtype
13106 -- of the parent, and we can also use it rather than its base,
13107 -- which can lead to more efficient code.
13109 if Etype (Id) = Parent_Type then
13110 if Is_Scalar_Type (Parent_Type)
13112 Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
13114 Set_Etype (New_Id, Derived_Type);
13116 elsif Nkind (Par) = N_Full_Type_Declaration
13118 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
13121 (Subtype_Indication (Type_Definition (Par)))
13123 Set_Etype (New_Id, Derived_Type);
13126 Set_Etype (New_Id, Base_Type (Derived_Type));
13130 Set_Etype (New_Id, Base_Type (Derived_Type));
13134 Set_Etype (New_Id, Etype (Id));
13138 ----------------------
13139 -- Set_Derived_Name --
13140 ----------------------
13142 procedure Set_Derived_Name is
13143 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
13145 if Nm = TSS_Null then
13146 Set_Chars (New_Subp, Chars (Parent_Subp));
13148 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
13150 end Set_Derived_Name;
13152 -- Start of processing for Derive_Subprogram
13156 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
13157 Set_Ekind (New_Subp, Ekind (Parent_Subp));
13158 Set_Contract (New_Subp, Make_Contract (Sloc (New_Subp)));
13160 -- Check whether the inherited subprogram is a private operation that
13161 -- should be inherited but not yet made visible. Such subprograms can
13162 -- become visible at a later point (e.g., the private part of a public
13163 -- child unit) via Declare_Inherited_Private_Subprograms. If the
13164 -- following predicate is true, then this is not such a private
13165 -- operation and the subprogram simply inherits the name of the parent
13166 -- subprogram. Note the special check for the names of controlled
13167 -- operations, which are currently exempted from being inherited with
13168 -- a hidden name because they must be findable for generation of
13169 -- implicit run-time calls.
13171 if not Is_Hidden (Parent_Subp)
13172 or else Is_Internal (Parent_Subp)
13173 or else Is_Private_Overriding
13174 or else Is_Internal_Name (Chars (Parent_Subp))
13175 or else Chars (Parent_Subp) = Name_Initialize
13176 or else Chars (Parent_Subp) = Name_Adjust
13177 or else Chars (Parent_Subp) = Name_Finalize
13181 -- An inherited dispatching equality will be overridden by an internally
13182 -- generated one, or by an explicit one, so preserve its name and thus
13183 -- its entry in the dispatch table. Otherwise, if Parent_Subp is a
13184 -- private operation it may become invisible if the full view has
13185 -- progenitors, and the dispatch table will be malformed.
13186 -- We check that the type is limited to handle the anomalous declaration
13187 -- of Limited_Controlled, which is derived from a non-limited type, and
13188 -- which is handled specially elsewhere as well.
13190 elsif Chars (Parent_Subp) = Name_Op_Eq
13191 and then Is_Dispatching_Operation (Parent_Subp)
13192 and then Etype (Parent_Subp) = Standard_Boolean
13193 and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp)))
13195 Etype (First_Formal (Parent_Subp)) =
13196 Etype (Next_Formal (First_Formal (Parent_Subp)))
13200 -- If parent is hidden, this can be a regular derivation if the
13201 -- parent is immediately visible in a non-instantiating context,
13202 -- or if we are in the private part of an instance. This test
13203 -- should still be refined ???
13205 -- The test for In_Instance_Not_Visible avoids inheriting the derived
13206 -- operation as a non-visible operation in cases where the parent
13207 -- subprogram might not be visible now, but was visible within the
13208 -- original generic, so it would be wrong to make the inherited
13209 -- subprogram non-visible now. (Not clear if this test is fully
13210 -- correct; are there any cases where we should declare the inherited
13211 -- operation as not visible to avoid it being overridden, e.g., when
13212 -- the parent type is a generic actual with private primitives ???)
13214 -- (they should be treated the same as other private inherited
13215 -- subprograms, but it's not clear how to do this cleanly). ???
13217 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
13218 and then Is_Immediately_Visible (Parent_Subp)
13219 and then not In_Instance)
13220 or else In_Instance_Not_Visible
13224 -- Ada 2005 (AI-251): Regular derivation if the parent subprogram
13225 -- overrides an interface primitive because interface primitives
13226 -- must be visible in the partial view of the parent (RM 7.3 (7.3/2))
13228 elsif Ada_Version >= Ada_2005
13229 and then Is_Dispatching_Operation (Parent_Subp)
13230 and then Covers_Some_Interface (Parent_Subp)
13234 -- Otherwise, the type is inheriting a private operation, so enter
13235 -- it with a special name so it can't be overridden.
13238 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
13241 Set_Parent (New_Subp, Parent (Derived_Type));
13243 if Present (Actual_Subp) then
13244 Replace_Type (Actual_Subp, New_Subp);
13246 Replace_Type (Parent_Subp, New_Subp);
13249 Conditional_Delay (New_Subp, Parent_Subp);
13251 -- If we are creating a renaming for a primitive operation of an
13252 -- actual of a generic derived type, we must examine the signature
13253 -- of the actual primitive, not that of the generic formal, which for
13254 -- example may be an interface. However the name and initial value
13255 -- of the inherited operation are those of the formal primitive.
13257 Formal := First_Formal (Parent_Subp);
13259 if Present (Actual_Subp) then
13260 Formal_Of_Actual := First_Formal (Actual_Subp);
13262 Formal_Of_Actual := Empty;
13265 while Present (Formal) loop
13266 New_Formal := New_Copy (Formal);
13268 -- Normally we do not go copying parents, but in the case of
13269 -- formals, we need to link up to the declaration (which is the
13270 -- parameter specification), and it is fine to link up to the
13271 -- original formal's parameter specification in this case.
13273 Set_Parent (New_Formal, Parent (Formal));
13274 Append_Entity (New_Formal, New_Subp);
13276 if Present (Formal_Of_Actual) then
13277 Replace_Type (Formal_Of_Actual, New_Formal);
13278 Next_Formal (Formal_Of_Actual);
13280 Replace_Type (Formal, New_Formal);
13283 Next_Formal (Formal);
13286 -- If this derivation corresponds to a tagged generic actual, then
13287 -- primitive operations rename those of the actual. Otherwise the
13288 -- primitive operations rename those of the parent type, If the parent
13289 -- renames an intrinsic operator, so does the new subprogram. We except
13290 -- concatenation, which is always properly typed, and does not get
13291 -- expanded as other intrinsic operations.
13293 if No (Actual_Subp) then
13294 if Is_Intrinsic_Subprogram (Parent_Subp) then
13295 Set_Is_Intrinsic_Subprogram (New_Subp);
13297 if Present (Alias (Parent_Subp))
13298 and then Chars (Parent_Subp) /= Name_Op_Concat
13300 Set_Alias (New_Subp, Alias (Parent_Subp));
13302 Set_Alias (New_Subp, Parent_Subp);
13306 Set_Alias (New_Subp, Parent_Subp);
13310 Set_Alias (New_Subp, Actual_Subp);
13313 -- Derived subprograms of a tagged type must inherit the convention
13314 -- of the parent subprogram (a requirement of AI-117). Derived
13315 -- subprograms of untagged types simply get convention Ada by default.
13317 if Is_Tagged_Type (Derived_Type) then
13318 Set_Convention (New_Subp, Convention (Parent_Subp));
13321 -- Predefined controlled operations retain their name even if the parent
13322 -- is hidden (see above), but they are not primitive operations if the
13323 -- ancestor is not visible, for example if the parent is a private
13324 -- extension completed with a controlled extension. Note that a full
13325 -- type that is controlled can break privacy: the flag Is_Controlled is
13326 -- set on both views of the type.
13328 if Is_Controlled (Parent_Type)
13330 (Chars (Parent_Subp) = Name_Initialize
13331 or else Chars (Parent_Subp) = Name_Adjust
13332 or else Chars (Parent_Subp) = Name_Finalize)
13333 and then Is_Hidden (Parent_Subp)
13334 and then not Is_Visibly_Controlled (Parent_Type)
13336 Set_Is_Hidden (New_Subp);
13339 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
13340 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
13342 if Ekind (Parent_Subp) = E_Procedure then
13343 Set_Is_Valued_Procedure
13344 (New_Subp, Is_Valued_Procedure (Parent_Subp));
13346 Set_Has_Controlling_Result
13347 (New_Subp, Has_Controlling_Result (Parent_Subp));
13350 -- No_Return must be inherited properly. If this is overridden in the
13351 -- case of a dispatching operation, then a check is made in Sem_Disp
13352 -- that the overriding operation is also No_Return (no such check is
13353 -- required for the case of non-dispatching operation.
13355 Set_No_Return (New_Subp, No_Return (Parent_Subp));
13357 -- A derived function with a controlling result is abstract. If the
13358 -- Derived_Type is a nonabstract formal generic derived type, then
13359 -- inherited operations are not abstract: the required check is done at
13360 -- instantiation time. If the derivation is for a generic actual, the
13361 -- function is not abstract unless the actual is.
13363 if Is_Generic_Type (Derived_Type)
13364 and then not Is_Abstract_Type (Derived_Type)
13368 -- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract"
13369 -- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2).
13371 elsif Ada_Version >= Ada_2005
13372 and then (Is_Abstract_Subprogram (Alias (New_Subp))
13373 or else (Is_Tagged_Type (Derived_Type)
13374 and then Etype (New_Subp) = Derived_Type
13375 and then not Is_Null_Extension (Derived_Type))
13376 or else (Is_Tagged_Type (Derived_Type)
13377 and then Ekind (Etype (New_Subp)) =
13378 E_Anonymous_Access_Type
13379 and then Designated_Type (Etype (New_Subp)) =
13381 and then not Is_Null_Extension (Derived_Type)))
13382 and then No (Actual_Subp)
13384 if not Is_Tagged_Type (Derived_Type)
13385 or else Is_Abstract_Type (Derived_Type)
13386 or else Is_Abstract_Subprogram (Alias (New_Subp))
13388 Set_Is_Abstract_Subprogram (New_Subp);
13390 Set_Requires_Overriding (New_Subp);
13393 elsif Ada_Version < Ada_2005
13394 and then (Is_Abstract_Subprogram (Alias (New_Subp))
13395 or else (Is_Tagged_Type (Derived_Type)
13396 and then Etype (New_Subp) = Derived_Type
13397 and then No (Actual_Subp)))
13399 Set_Is_Abstract_Subprogram (New_Subp);
13401 -- AI05-0097 : an inherited operation that dispatches on result is
13402 -- abstract if the derived type is abstract, even if the parent type
13403 -- is concrete and the derived type is a null extension.
13405 elsif Has_Controlling_Result (Alias (New_Subp))
13406 and then Is_Abstract_Type (Etype (New_Subp))
13408 Set_Is_Abstract_Subprogram (New_Subp);
13410 -- Finally, if the parent type is abstract we must verify that all
13411 -- inherited operations are either non-abstract or overridden, or that
13412 -- the derived type itself is abstract (this check is performed at the
13413 -- end of a package declaration, in Check_Abstract_Overriding). A
13414 -- private overriding in the parent type will not be visible in the
13415 -- derivation if we are not in an inner package or in a child unit of
13416 -- the parent type, in which case the abstractness of the inherited
13417 -- operation is carried to the new subprogram.
13419 elsif Is_Abstract_Type (Parent_Type)
13420 and then not In_Open_Scopes (Scope (Parent_Type))
13421 and then Is_Private_Overriding
13422 and then Is_Abstract_Subprogram (Visible_Subp)
13424 if No (Actual_Subp) then
13425 Set_Alias (New_Subp, Visible_Subp);
13426 Set_Is_Abstract_Subprogram (New_Subp, True);
13429 -- If this is a derivation for an instance of a formal derived
13430 -- type, abstractness comes from the primitive operation of the
13431 -- actual, not from the operation inherited from the ancestor.
13433 Set_Is_Abstract_Subprogram
13434 (New_Subp, Is_Abstract_Subprogram (Actual_Subp));
13438 New_Overloaded_Entity (New_Subp, Derived_Type);
13440 -- Check for case of a derived subprogram for the instantiation of a
13441 -- formal derived tagged type, if so mark the subprogram as dispatching
13442 -- and inherit the dispatching attributes of the actual subprogram. The
13443 -- derived subprogram is effectively renaming of the actual subprogram,
13444 -- so it needs to have the same attributes as the actual.
13446 if Present (Actual_Subp)
13447 and then Is_Dispatching_Operation (Actual_Subp)
13449 Set_Is_Dispatching_Operation (New_Subp);
13451 if Present (DTC_Entity (Actual_Subp)) then
13452 Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp));
13453 Set_DT_Position (New_Subp, DT_Position (Actual_Subp));
13457 -- Indicate that a derived subprogram does not require a body and that
13458 -- it does not require processing of default expressions.
13460 Set_Has_Completion (New_Subp);
13461 Set_Default_Expressions_Processed (New_Subp);
13463 if Ekind (New_Subp) = E_Function then
13464 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
13466 end Derive_Subprogram;
13468 ------------------------
13469 -- Derive_Subprograms --
13470 ------------------------
13472 procedure Derive_Subprograms
13473 (Parent_Type : Entity_Id;
13474 Derived_Type : Entity_Id;
13475 Generic_Actual : Entity_Id := Empty)
13477 Op_List : constant Elist_Id :=
13478 Collect_Primitive_Operations (Parent_Type);
13480 function Check_Derived_Type return Boolean;
13481 -- Check that all the entities derived from Parent_Type are found in
13482 -- the list of primitives of Derived_Type exactly in the same order.
13484 procedure Derive_Interface_Subprogram
13485 (New_Subp : in out Entity_Id;
13487 Actual_Subp : Entity_Id);
13488 -- Derive New_Subp from the ultimate alias of the parent subprogram Subp
13489 -- (which is an interface primitive). If Generic_Actual is present then
13490 -- Actual_Subp is the actual subprogram corresponding with the generic
13491 -- subprogram Subp.
13493 function Check_Derived_Type return Boolean is
13497 New_Subp : Entity_Id;
13502 -- Traverse list of entities in the current scope searching for
13503 -- an incomplete type whose full-view is derived type
13505 E := First_Entity (Scope (Derived_Type));
13507 and then E /= Derived_Type
13509 if Ekind (E) = E_Incomplete_Type
13510 and then Present (Full_View (E))
13511 and then Full_View (E) = Derived_Type
13513 -- Disable this test if Derived_Type completes an incomplete
13514 -- type because in such case more primitives can be added
13515 -- later to the list of primitives of Derived_Type by routine
13516 -- Process_Incomplete_Dependents
13521 E := Next_Entity (E);
13524 List := Collect_Primitive_Operations (Derived_Type);
13525 Elmt := First_Elmt (List);
13527 Op_Elmt := First_Elmt (Op_List);
13528 while Present (Op_Elmt) loop
13529 Subp := Node (Op_Elmt);
13530 New_Subp := Node (Elmt);
13532 -- At this early stage Derived_Type has no entities with attribute
13533 -- Interface_Alias. In addition, such primitives are always
13534 -- located at the end of the list of primitives of Parent_Type.
13535 -- Therefore, if found we can safely stop processing pending
13538 exit when Present (Interface_Alias (Subp));
13540 -- Handle hidden entities
13542 if not Is_Predefined_Dispatching_Operation (Subp)
13543 and then Is_Hidden (Subp)
13545 if Present (New_Subp)
13546 and then Primitive_Names_Match (Subp, New_Subp)
13552 if not Present (New_Subp)
13553 or else Ekind (Subp) /= Ekind (New_Subp)
13554 or else not Primitive_Names_Match (Subp, New_Subp)
13562 Next_Elmt (Op_Elmt);
13566 end Check_Derived_Type;
13568 ---------------------------------
13569 -- Derive_Interface_Subprogram --
13570 ---------------------------------
13572 procedure Derive_Interface_Subprogram
13573 (New_Subp : in out Entity_Id;
13575 Actual_Subp : Entity_Id)
13577 Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp);
13578 Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp);
13581 pragma Assert (Is_Interface (Iface_Type));
13584 (New_Subp => New_Subp,
13585 Parent_Subp => Iface_Subp,
13586 Derived_Type => Derived_Type,
13587 Parent_Type => Iface_Type,
13588 Actual_Subp => Actual_Subp);
13590 -- Given that this new interface entity corresponds with a primitive
13591 -- of the parent that was not overridden we must leave it associated
13592 -- with its parent primitive to ensure that it will share the same
13593 -- dispatch table slot when overridden.
13595 if No (Actual_Subp) then
13596 Set_Alias (New_Subp, Subp);
13598 -- For instantiations this is not needed since the previous call to
13599 -- Derive_Subprogram leaves the entity well decorated.
13602 pragma Assert (Alias (New_Subp) = Actual_Subp);
13605 end Derive_Interface_Subprogram;
13609 Alias_Subp : Entity_Id;
13610 Act_List : Elist_Id;
13611 Act_Elmt : Elmt_Id := No_Elmt;
13612 Act_Subp : Entity_Id := Empty;
13614 Need_Search : Boolean := False;
13615 New_Subp : Entity_Id := Empty;
13616 Parent_Base : Entity_Id;
13619 -- Start of processing for Derive_Subprograms
13622 if Ekind (Parent_Type) = E_Record_Type_With_Private
13623 and then Has_Discriminants (Parent_Type)
13624 and then Present (Full_View (Parent_Type))
13626 Parent_Base := Full_View (Parent_Type);
13628 Parent_Base := Parent_Type;
13631 if Present (Generic_Actual) then
13632 Act_List := Collect_Primitive_Operations (Generic_Actual);
13633 Act_Elmt := First_Elmt (Act_List);
13636 -- Derive primitives inherited from the parent. Note that if the generic
13637 -- actual is present, this is not really a type derivation, it is a
13638 -- completion within an instance.
13640 -- Case 1: Derived_Type does not implement interfaces
13642 if not Is_Tagged_Type (Derived_Type)
13643 or else (not Has_Interfaces (Derived_Type)
13644 and then not (Present (Generic_Actual)
13646 Has_Interfaces (Generic_Actual)))
13648 Elmt := First_Elmt (Op_List);
13649 while Present (Elmt) loop
13650 Subp := Node (Elmt);
13652 -- Literals are derived earlier in the process of building the
13653 -- derived type, and are skipped here.
13655 if Ekind (Subp) = E_Enumeration_Literal then
13658 -- The actual is a direct descendant and the common primitive
13659 -- operations appear in the same order.
13661 -- If the generic parent type is present, the derived type is an
13662 -- instance of a formal derived type, and within the instance its
13663 -- operations are those of the actual. We derive from the formal
13664 -- type but make the inherited operations aliases of the
13665 -- corresponding operations of the actual.
13668 pragma Assert (No (Node (Act_Elmt))
13669 or else (Primitive_Names_Match (Subp, Node (Act_Elmt))
13671 Type_Conformant (Subp, Node (Act_Elmt),
13672 Skip_Controlling_Formals => True)));
13675 (New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt));
13677 if Present (Act_Elmt) then
13678 Next_Elmt (Act_Elmt);
13685 -- Case 2: Derived_Type implements interfaces
13688 -- If the parent type has no predefined primitives we remove
13689 -- predefined primitives from the list of primitives of generic
13690 -- actual to simplify the complexity of this algorithm.
13692 if Present (Generic_Actual) then
13694 Has_Predefined_Primitives : Boolean := False;
13697 -- Check if the parent type has predefined primitives
13699 Elmt := First_Elmt (Op_List);
13700 while Present (Elmt) loop
13701 Subp := Node (Elmt);
13703 if Is_Predefined_Dispatching_Operation (Subp)
13704 and then not Comes_From_Source (Ultimate_Alias (Subp))
13706 Has_Predefined_Primitives := True;
13713 -- Remove predefined primitives of Generic_Actual. We must use
13714 -- an auxiliary list because in case of tagged types the value
13715 -- returned by Collect_Primitive_Operations is the value stored
13716 -- in its Primitive_Operations attribute (and we don't want to
13717 -- modify its current contents).
13719 if not Has_Predefined_Primitives then
13721 Aux_List : constant Elist_Id := New_Elmt_List;
13724 Elmt := First_Elmt (Act_List);
13725 while Present (Elmt) loop
13726 Subp := Node (Elmt);
13728 if not Is_Predefined_Dispatching_Operation (Subp)
13729 or else Comes_From_Source (Subp)
13731 Append_Elmt (Subp, Aux_List);
13737 Act_List := Aux_List;
13741 Act_Elmt := First_Elmt (Act_List);
13742 Act_Subp := Node (Act_Elmt);
13746 -- Stage 1: If the generic actual is not present we derive the
13747 -- primitives inherited from the parent type. If the generic parent
13748 -- type is present, the derived type is an instance of a formal
13749 -- derived type, and within the instance its operations are those of
13750 -- the actual. We derive from the formal type but make the inherited
13751 -- operations aliases of the corresponding operations of the actual.
13753 Elmt := First_Elmt (Op_List);
13754 while Present (Elmt) loop
13755 Subp := Node (Elmt);
13756 Alias_Subp := Ultimate_Alias (Subp);
13758 -- Do not derive internal entities of the parent that link
13759 -- interface primitives with their covering primitive. These
13760 -- entities will be added to this type when frozen.
13762 if Present (Interface_Alias (Subp)) then
13766 -- If the generic actual is present find the corresponding
13767 -- operation in the generic actual. If the parent type is a
13768 -- direct ancestor of the derived type then, even if it is an
13769 -- interface, the operations are inherited from the primary
13770 -- dispatch table and are in the proper order. If we detect here
13771 -- that primitives are not in the same order we traverse the list
13772 -- of primitive operations of the actual to find the one that
13773 -- implements the interface primitive.
13777 (Present (Generic_Actual)
13778 and then Present (Act_Subp)
13780 (Primitive_Names_Match (Subp, Act_Subp)
13782 Type_Conformant (Subp, Act_Subp,
13783 Skip_Controlling_Formals => True)))
13785 pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual,
13786 Use_Full_View => True));
13788 -- Remember that we need searching for all pending primitives
13790 Need_Search := True;
13792 -- Handle entities associated with interface primitives
13794 if Present (Alias_Subp)
13795 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
13796 and then not Is_Predefined_Dispatching_Operation (Subp)
13798 -- Search for the primitive in the homonym chain
13801 Find_Primitive_Covering_Interface
13802 (Tagged_Type => Generic_Actual,
13803 Iface_Prim => Alias_Subp);
13805 -- Previous search may not locate primitives covering
13806 -- interfaces defined in generics units or instantiations.
13807 -- (it fails if the covering primitive has formals whose
13808 -- type is also defined in generics or instantiations).
13809 -- In such case we search in the list of primitives of the
13810 -- generic actual for the internal entity that links the
13811 -- interface primitive and the covering primitive.
13814 and then Is_Generic_Type (Parent_Type)
13816 -- This code has been designed to handle only generic
13817 -- formals that implement interfaces that are defined
13818 -- in a generic unit or instantiation. If this code is
13819 -- needed for other cases we must review it because
13820 -- (given that it relies on Original_Location to locate
13821 -- the primitive of Generic_Actual that covers the
13822 -- interface) it could leave linked through attribute
13823 -- Alias entities of unrelated instantiations).
13827 (Scope (Find_Dispatching_Type (Alias_Subp)))
13829 Instantiation_Depth
13830 (Sloc (Find_Dispatching_Type (Alias_Subp))) > 0);
13833 Iface_Prim_Loc : constant Source_Ptr :=
13834 Original_Location (Sloc (Alias_Subp));
13839 First_Elmt (Primitive_Operations (Generic_Actual));
13841 Search : while Present (Elmt) loop
13842 Prim := Node (Elmt);
13844 if Present (Interface_Alias (Prim))
13845 and then Original_Location
13846 (Sloc (Interface_Alias (Prim)))
13849 Act_Subp := Alias (Prim);
13858 pragma Assert (Present (Act_Subp)
13859 or else Is_Abstract_Type (Generic_Actual)
13860 or else Serious_Errors_Detected > 0);
13862 -- Handle predefined primitives plus the rest of user-defined
13866 Act_Elmt := First_Elmt (Act_List);
13867 while Present (Act_Elmt) loop
13868 Act_Subp := Node (Act_Elmt);
13870 exit when Primitive_Names_Match (Subp, Act_Subp)
13871 and then Type_Conformant
13873 Skip_Controlling_Formals => True)
13874 and then No (Interface_Alias (Act_Subp));
13876 Next_Elmt (Act_Elmt);
13879 if No (Act_Elmt) then
13885 -- Case 1: If the parent is a limited interface then it has the
13886 -- predefined primitives of synchronized interfaces. However, the
13887 -- actual type may be a non-limited type and hence it does not
13888 -- have such primitives.
13890 if Present (Generic_Actual)
13891 and then not Present (Act_Subp)
13892 and then Is_Limited_Interface (Parent_Base)
13893 and then Is_Predefined_Interface_Primitive (Subp)
13897 -- Case 2: Inherit entities associated with interfaces that were
13898 -- not covered by the parent type. We exclude here null interface
13899 -- primitives because they do not need special management.
13901 -- We also exclude interface operations that are renamings. If the
13902 -- subprogram is an explicit renaming of an interface primitive,
13903 -- it is a regular primitive operation, and the presence of its
13904 -- alias is not relevant: it has to be derived like any other
13907 elsif Present (Alias (Subp))
13908 and then Nkind (Unit_Declaration_Node (Subp)) /=
13909 N_Subprogram_Renaming_Declaration
13910 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
13912 (Nkind (Parent (Alias_Subp)) = N_Procedure_Specification
13913 and then Null_Present (Parent (Alias_Subp)))
13915 -- If this is an abstract private type then we transfer the
13916 -- derivation of the interface primitive from the partial view
13917 -- to the full view. This is safe because all the interfaces
13918 -- must be visible in the partial view. Done to avoid adding
13919 -- a new interface derivation to the private part of the
13920 -- enclosing package; otherwise this new derivation would be
13921 -- decorated as hidden when the analysis of the enclosing
13922 -- package completes.
13924 if Is_Abstract_Type (Derived_Type)
13925 and then In_Private_Part (Current_Scope)
13926 and then Has_Private_Declaration (Derived_Type)
13929 Partial_View : Entity_Id;
13934 Partial_View := First_Entity (Current_Scope);
13936 exit when No (Partial_View)
13937 or else (Has_Private_Declaration (Partial_View)
13939 Full_View (Partial_View) = Derived_Type);
13941 Next_Entity (Partial_View);
13944 -- If the partial view was not found then the source code
13945 -- has errors and the derivation is not needed.
13947 if Present (Partial_View) then
13949 First_Elmt (Primitive_Operations (Partial_View));
13950 while Present (Elmt) loop
13951 Ent := Node (Elmt);
13953 if Present (Alias (Ent))
13954 and then Ultimate_Alias (Ent) = Alias (Subp)
13957 (Ent, Primitive_Operations (Derived_Type));
13964 -- If the interface primitive was not found in the
13965 -- partial view then this interface primitive was
13966 -- overridden. We add a derivation to activate in
13967 -- Derive_Progenitor_Subprograms the machinery to
13971 Derive_Interface_Subprogram
13972 (New_Subp => New_Subp,
13974 Actual_Subp => Act_Subp);
13979 Derive_Interface_Subprogram
13980 (New_Subp => New_Subp,
13982 Actual_Subp => Act_Subp);
13985 -- Case 3: Common derivation
13989 (New_Subp => New_Subp,
13990 Parent_Subp => Subp,
13991 Derived_Type => Derived_Type,
13992 Parent_Type => Parent_Base,
13993 Actual_Subp => Act_Subp);
13996 -- No need to update Act_Elm if we must search for the
13997 -- corresponding operation in the generic actual
14000 and then Present (Act_Elmt)
14002 Next_Elmt (Act_Elmt);
14003 Act_Subp := Node (Act_Elmt);
14010 -- Inherit additional operations from progenitors. If the derived
14011 -- type is a generic actual, there are not new primitive operations
14012 -- for the type because it has those of the actual, and therefore
14013 -- nothing needs to be done. The renamings generated above are not
14014 -- primitive operations, and their purpose is simply to make the
14015 -- proper operations visible within an instantiation.
14017 if No (Generic_Actual) then
14018 Derive_Progenitor_Subprograms (Parent_Base, Derived_Type);
14022 -- Final check: Direct descendants must have their primitives in the
14023 -- same order. We exclude from this test untagged types and instances
14024 -- of formal derived types. We skip this test if we have already
14025 -- reported serious errors in the sources.
14027 pragma Assert (not Is_Tagged_Type (Derived_Type)
14028 or else Present (Generic_Actual)
14029 or else Serious_Errors_Detected > 0
14030 or else Check_Derived_Type);
14031 end Derive_Subprograms;
14033 --------------------------------
14034 -- Derived_Standard_Character --
14035 --------------------------------
14037 procedure Derived_Standard_Character
14039 Parent_Type : Entity_Id;
14040 Derived_Type : Entity_Id)
14042 Loc : constant Source_Ptr := Sloc (N);
14043 Def : constant Node_Id := Type_Definition (N);
14044 Indic : constant Node_Id := Subtype_Indication (Def);
14045 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
14046 Implicit_Base : constant Entity_Id :=
14048 (E_Enumeration_Type, N, Derived_Type, 'B');
14054 Discard_Node (Process_Subtype (Indic, N));
14056 Set_Etype (Implicit_Base, Parent_Base);
14057 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
14058 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
14060 Set_Is_Character_Type (Implicit_Base, True);
14061 Set_Has_Delayed_Freeze (Implicit_Base);
14063 -- The bounds of the implicit base are the bounds of the parent base.
14064 -- Note that their type is the parent base.
14066 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
14067 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
14069 Set_Scalar_Range (Implicit_Base,
14072 High_Bound => Hi));
14074 Conditional_Delay (Derived_Type, Parent_Type);
14076 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
14077 Set_Etype (Derived_Type, Implicit_Base);
14078 Set_Size_Info (Derived_Type, Parent_Type);
14080 if Unknown_RM_Size (Derived_Type) then
14081 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
14084 Set_Is_Character_Type (Derived_Type, True);
14086 if Nkind (Indic) /= N_Subtype_Indication then
14088 -- If no explicit constraint, the bounds are those
14089 -- of the parent type.
14091 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
14092 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
14093 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
14096 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
14098 -- Because the implicit base is used in the conversion of the bounds, we
14099 -- have to freeze it now. This is similar to what is done for numeric
14100 -- types, and it equally suspicious, but otherwise a non-static bound
14101 -- will have a reference to an unfrozen type, which is rejected by Gigi
14102 -- (???). This requires specific care for definition of stream
14103 -- attributes. For details, see comments at the end of
14104 -- Build_Derived_Numeric_Type.
14106 Freeze_Before (N, Implicit_Base);
14107 end Derived_Standard_Character;
14109 ------------------------------
14110 -- Derived_Type_Declaration --
14111 ------------------------------
14113 procedure Derived_Type_Declaration
14116 Is_Completion : Boolean)
14118 Parent_Type : Entity_Id;
14120 function Comes_From_Generic (Typ : Entity_Id) return Boolean;
14121 -- Check whether the parent type is a generic formal, or derives
14122 -- directly or indirectly from one.
14124 ------------------------
14125 -- Comes_From_Generic --
14126 ------------------------
14128 function Comes_From_Generic (Typ : Entity_Id) return Boolean is
14130 if Is_Generic_Type (Typ) then
14133 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
14136 elsif Is_Private_Type (Typ)
14137 and then Present (Full_View (Typ))
14138 and then Is_Generic_Type (Root_Type (Full_View (Typ)))
14142 elsif Is_Generic_Actual_Type (Typ) then
14148 end Comes_From_Generic;
14152 Def : constant Node_Id := Type_Definition (N);
14153 Iface_Def : Node_Id;
14154 Indic : constant Node_Id := Subtype_Indication (Def);
14155 Extension : constant Node_Id := Record_Extension_Part (Def);
14156 Parent_Node : Node_Id;
14159 -- Start of processing for Derived_Type_Declaration
14162 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
14164 -- Ada 2005 (AI-251): In case of interface derivation check that the
14165 -- parent is also an interface.
14167 if Interface_Present (Def) then
14168 Check_SPARK_Restriction ("interface is not allowed", Def);
14170 if not Is_Interface (Parent_Type) then
14171 Diagnose_Interface (Indic, Parent_Type);
14174 Parent_Node := Parent (Base_Type (Parent_Type));
14175 Iface_Def := Type_Definition (Parent_Node);
14177 -- Ada 2005 (AI-251): Limited interfaces can only inherit from
14178 -- other limited interfaces.
14180 if Limited_Present (Def) then
14181 if Limited_Present (Iface_Def) then
14184 elsif Protected_Present (Iface_Def) then
14186 ("descendant of& must be declared"
14187 & " as a protected interface",
14190 elsif Synchronized_Present (Iface_Def) then
14192 ("descendant of& must be declared"
14193 & " as a synchronized interface",
14196 elsif Task_Present (Iface_Def) then
14198 ("descendant of& must be declared as a task interface",
14203 ("(Ada 2005) limited interface cannot "
14204 & "inherit from non-limited interface", Indic);
14207 -- Ada 2005 (AI-345): Non-limited interfaces can only inherit
14208 -- from non-limited or limited interfaces.
14210 elsif not Protected_Present (Def)
14211 and then not Synchronized_Present (Def)
14212 and then not Task_Present (Def)
14214 if Limited_Present (Iface_Def) then
14217 elsif Protected_Present (Iface_Def) then
14219 ("descendant of& must be declared"
14220 & " as a protected interface",
14223 elsif Synchronized_Present (Iface_Def) then
14225 ("descendant of& must be declared"
14226 & " as a synchronized interface",
14229 elsif Task_Present (Iface_Def) then
14231 ("descendant of& must be declared as a task interface",
14240 if Is_Tagged_Type (Parent_Type)
14241 and then Is_Concurrent_Type (Parent_Type)
14242 and then not Is_Interface (Parent_Type)
14245 ("parent type of a record extension cannot be "
14246 & "a synchronized tagged type (RM 3.9.1 (3/1))", N);
14247 Set_Etype (T, Any_Type);
14251 -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
14254 if Is_Tagged_Type (Parent_Type)
14255 and then Is_Non_Empty_List (Interface_List (Def))
14262 Intf := First (Interface_List (Def));
14263 while Present (Intf) loop
14264 T := Find_Type_Of_Subtype_Indic (Intf);
14266 if not Is_Interface (T) then
14267 Diagnose_Interface (Intf, T);
14269 -- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow
14270 -- a limited type from having a nonlimited progenitor.
14272 elsif (Limited_Present (Def)
14273 or else (not Is_Interface (Parent_Type)
14274 and then Is_Limited_Type (Parent_Type)))
14275 and then not Is_Limited_Interface (T)
14278 ("progenitor interface& of limited type must be limited",
14287 if Parent_Type = Any_Type
14288 or else Etype (Parent_Type) = Any_Type
14289 or else (Is_Class_Wide_Type (Parent_Type)
14290 and then Etype (Parent_Type) = T)
14292 -- If Parent_Type is undefined or illegal, make new type into a
14293 -- subtype of Any_Type, and set a few attributes to prevent cascaded
14294 -- errors. If this is a self-definition, emit error now.
14297 or else T = Etype (Parent_Type)
14299 Error_Msg_N ("type cannot be used in its own definition", Indic);
14302 Set_Ekind (T, Ekind (Parent_Type));
14303 Set_Etype (T, Any_Type);
14304 Set_Scalar_Range (T, Scalar_Range (Any_Type));
14306 if Is_Tagged_Type (T)
14307 and then Is_Record_Type (T)
14309 Set_Direct_Primitive_Operations (T, New_Elmt_List);
14315 -- Ada 2005 (AI-251): The case in which the parent of the full-view is
14316 -- an interface is special because the list of interfaces in the full
14317 -- view can be given in any order. For example:
14319 -- type A is interface;
14320 -- type B is interface and A;
14321 -- type D is new B with private;
14323 -- type D is new A and B with null record; -- 1 --
14325 -- In this case we perform the following transformation of -1-:
14327 -- type D is new B and A with null record;
14329 -- If the parent of the full-view covers the parent of the partial-view
14330 -- we have two possible cases:
14332 -- 1) They have the same parent
14333 -- 2) The parent of the full-view implements some further interfaces
14335 -- In both cases we do not need to perform the transformation. In the
14336 -- first case the source program is correct and the transformation is
14337 -- not needed; in the second case the source program does not fulfill
14338 -- the no-hidden interfaces rule (AI-396) and the error will be reported
14341 -- This transformation not only simplifies the rest of the analysis of
14342 -- this type declaration but also simplifies the correct generation of
14343 -- the object layout to the expander.
14345 if In_Private_Part (Current_Scope)
14346 and then Is_Interface (Parent_Type)
14350 Partial_View : Entity_Id;
14351 Partial_View_Parent : Entity_Id;
14352 New_Iface : Node_Id;
14355 -- Look for the associated private type declaration
14357 Partial_View := First_Entity (Current_Scope);
14359 exit when No (Partial_View)
14360 or else (Has_Private_Declaration (Partial_View)
14361 and then Full_View (Partial_View) = T);
14363 Next_Entity (Partial_View);
14366 -- If the partial view was not found then the source code has
14367 -- errors and the transformation is not needed.
14369 if Present (Partial_View) then
14370 Partial_View_Parent := Etype (Partial_View);
14372 -- If the parent of the full-view covers the parent of the
14373 -- partial-view we have nothing else to do.
14375 if Interface_Present_In_Ancestor
14376 (Parent_Type, Partial_View_Parent)
14380 -- Traverse the list of interfaces of the full-view to look
14381 -- for the parent of the partial-view and perform the tree
14385 Iface := First (Interface_List (Def));
14386 while Present (Iface) loop
14387 if Etype (Iface) = Etype (Partial_View) then
14388 Rewrite (Subtype_Indication (Def),
14389 New_Copy (Subtype_Indication
14390 (Parent (Partial_View))));
14393 Make_Identifier (Sloc (N), Chars (Parent_Type));
14394 Append (New_Iface, Interface_List (Def));
14396 -- Analyze the transformed code
14398 Derived_Type_Declaration (T, N, Is_Completion);
14409 -- Only composite types other than array types are allowed to have
14410 -- discriminants. In SPARK, no types are allowed to have discriminants.
14412 if Present (Discriminant_Specifications (N)) then
14413 if (Is_Elementary_Type (Parent_Type)
14414 or else Is_Array_Type (Parent_Type))
14415 and then not Error_Posted (N)
14418 ("elementary or array type cannot have discriminants",
14419 Defining_Identifier (First (Discriminant_Specifications (N))));
14420 Set_Has_Discriminants (T, False);
14422 Check_SPARK_Restriction ("discriminant type is not allowed", N);
14426 -- In Ada 83, a derived type defined in a package specification cannot
14427 -- be used for further derivation until the end of its visible part.
14428 -- Note that derivation in the private part of the package is allowed.
14430 if Ada_Version = Ada_83
14431 and then Is_Derived_Type (Parent_Type)
14432 and then In_Visible_Part (Scope (Parent_Type))
14434 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
14436 ("(Ada 83): premature use of type for derivation", Indic);
14440 -- Check for early use of incomplete or private type
14442 if Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
14443 Error_Msg_N ("premature derivation of incomplete type", Indic);
14446 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
14447 and then not Comes_From_Generic (Parent_Type))
14448 or else Has_Private_Component (Parent_Type)
14450 -- The ancestor type of a formal type can be incomplete, in which
14451 -- case only the operations of the partial view are available in the
14452 -- generic. Subsequent checks may be required when the full view is
14453 -- analyzed to verify that a derivation from a tagged type has an
14456 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
14459 elsif No (Underlying_Type (Parent_Type))
14460 or else Has_Private_Component (Parent_Type)
14463 ("premature derivation of derived or private type", Indic);
14465 -- Flag the type itself as being in error, this prevents some
14466 -- nasty problems with subsequent uses of the malformed type.
14468 Set_Error_Posted (T);
14470 -- Check that within the immediate scope of an untagged partial
14471 -- view it's illegal to derive from the partial view if the
14472 -- full view is tagged. (7.3(7))
14474 -- We verify that the Parent_Type is a partial view by checking
14475 -- that it is not a Full_Type_Declaration (i.e. a private type or
14476 -- private extension declaration), to distinguish a partial view
14477 -- from a derivation from a private type which also appears as
14478 -- E_Private_Type. If the parent base type is not declared in an
14479 -- enclosing scope there is no need to check.
14481 elsif Present (Full_View (Parent_Type))
14482 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
14483 and then not Is_Tagged_Type (Parent_Type)
14484 and then Is_Tagged_Type (Full_View (Parent_Type))
14485 and then In_Open_Scopes (Scope (Base_Type (Parent_Type)))
14488 ("premature derivation from type with tagged full view",
14493 -- Check that form of derivation is appropriate
14495 Taggd := Is_Tagged_Type (Parent_Type);
14497 -- Perhaps the parent type should be changed to the class-wide type's
14498 -- specific type in this case to prevent cascading errors ???
14500 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
14501 Error_Msg_N ("parent type must not be a class-wide type", Indic);
14505 if Present (Extension) and then not Taggd then
14507 ("type derived from untagged type cannot have extension", Indic);
14509 elsif No (Extension) and then Taggd then
14511 -- If this declaration is within a private part (or body) of a
14512 -- generic instantiation then the derivation is allowed (the parent
14513 -- type can only appear tagged in this case if it's a generic actual
14514 -- type, since it would otherwise have been rejected in the analysis
14515 -- of the generic template).
14517 if not Is_Generic_Actual_Type (Parent_Type)
14518 or else In_Visible_Part (Scope (Parent_Type))
14520 if Is_Class_Wide_Type (Parent_Type) then
14522 ("parent type must not be a class-wide type", Indic);
14524 -- Use specific type to prevent cascaded errors.
14526 Parent_Type := Etype (Parent_Type);
14530 ("type derived from tagged type must have extension", Indic);
14535 -- AI-443: Synchronized formal derived types require a private
14536 -- extension. There is no point in checking the ancestor type or
14537 -- the progenitors since the construct is wrong to begin with.
14539 if Ada_Version >= Ada_2005
14540 and then Is_Generic_Type (T)
14541 and then Present (Original_Node (N))
14544 Decl : constant Node_Id := Original_Node (N);
14547 if Nkind (Decl) = N_Formal_Type_Declaration
14548 and then Nkind (Formal_Type_Definition (Decl)) =
14549 N_Formal_Derived_Type_Definition
14550 and then Synchronized_Present (Formal_Type_Definition (Decl))
14551 and then No (Extension)
14553 -- Avoid emitting a duplicate error message
14555 and then not Error_Posted (Indic)
14558 ("synchronized derived type must have extension", N);
14563 if Null_Exclusion_Present (Def)
14564 and then not Is_Access_Type (Parent_Type)
14566 Error_Msg_N ("null exclusion can only apply to an access type", N);
14569 -- Avoid deriving parent primitives of underlying record views
14571 Build_Derived_Type (N, Parent_Type, T, Is_Completion,
14572 Derive_Subps => not Is_Underlying_Record_View (T));
14574 -- AI-419: The parent type of an explicitly limited derived type must
14575 -- be a limited type or a limited interface.
14577 if Limited_Present (Def) then
14578 Set_Is_Limited_Record (T);
14580 if Is_Interface (T) then
14581 Set_Is_Limited_Interface (T);
14584 if not Is_Limited_Type (Parent_Type)
14586 (not Is_Interface (Parent_Type)
14587 or else not Is_Limited_Interface (Parent_Type))
14589 -- AI05-0096: a derivation in the private part of an instance is
14590 -- legal if the generic formal is untagged limited, and the actual
14593 if Is_Generic_Actual_Type (Parent_Type)
14594 and then In_Private_Part (Current_Scope)
14597 (Generic_Parent_Type (Parent (Parent_Type)))
14603 ("parent type& of limited type must be limited",
14609 -- In SPARK, there are no derived type definitions other than type
14610 -- extensions of tagged record types.
14612 if No (Extension) then
14613 Check_SPARK_Restriction ("derived type is not allowed", N);
14615 end Derived_Type_Declaration;
14617 ------------------------
14618 -- Diagnose_Interface --
14619 ------------------------
14621 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is
14623 if not Is_Interface (E)
14624 and then E /= Any_Type
14626 Error_Msg_NE ("(Ada 2005) & must be an interface", N, E);
14628 end Diagnose_Interface;
14630 ----------------------------------
14631 -- Enumeration_Type_Declaration --
14632 ----------------------------------
14634 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
14641 -- Create identifier node representing lower bound
14643 B_Node := New_Node (N_Identifier, Sloc (Def));
14644 L := First (Literals (Def));
14645 Set_Chars (B_Node, Chars (L));
14646 Set_Entity (B_Node, L);
14647 Set_Etype (B_Node, T);
14648 Set_Is_Static_Expression (B_Node, True);
14650 R_Node := New_Node (N_Range, Sloc (Def));
14651 Set_Low_Bound (R_Node, B_Node);
14653 Set_Ekind (T, E_Enumeration_Type);
14654 Set_First_Literal (T, L);
14656 Set_Is_Constrained (T);
14660 -- Loop through literals of enumeration type setting pos and rep values
14661 -- except that if the Ekind is already set, then it means the literal
14662 -- was already constructed (case of a derived type declaration and we
14663 -- should not disturb the Pos and Rep values.
14665 while Present (L) loop
14666 if Ekind (L) /= E_Enumeration_Literal then
14667 Set_Ekind (L, E_Enumeration_Literal);
14668 Set_Enumeration_Pos (L, Ev);
14669 Set_Enumeration_Rep (L, Ev);
14670 Set_Is_Known_Valid (L, True);
14674 New_Overloaded_Entity (L);
14675 Generate_Definition (L);
14676 Set_Convention (L, Convention_Intrinsic);
14678 -- Case of character literal
14680 if Nkind (L) = N_Defining_Character_Literal then
14681 Set_Is_Character_Type (T, True);
14683 -- Check violation of No_Wide_Characters
14685 if Restriction_Check_Required (No_Wide_Characters) then
14686 Get_Name_String (Chars (L));
14688 if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then
14689 Check_Restriction (No_Wide_Characters, L);
14698 -- Now create a node representing upper bound
14700 B_Node := New_Node (N_Identifier, Sloc (Def));
14701 Set_Chars (B_Node, Chars (Last (Literals (Def))));
14702 Set_Entity (B_Node, Last (Literals (Def)));
14703 Set_Etype (B_Node, T);
14704 Set_Is_Static_Expression (B_Node, True);
14706 Set_High_Bound (R_Node, B_Node);
14708 -- Initialize various fields of the type. Some of this information
14709 -- may be overwritten later through rep.clauses.
14711 Set_Scalar_Range (T, R_Node);
14712 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
14713 Set_Enum_Esize (T);
14714 Set_Enum_Pos_To_Rep (T, Empty);
14716 -- Set Discard_Names if configuration pragma set, or if there is
14717 -- a parameterless pragma in the current declarative region
14719 if Global_Discard_Names
14720 or else Discard_Names (Scope (T))
14722 Set_Discard_Names (T);
14725 -- Process end label if there is one
14727 if Present (Def) then
14728 Process_End_Label (Def, 'e', T);
14730 end Enumeration_Type_Declaration;
14732 ---------------------------------
14733 -- Expand_To_Stored_Constraint --
14734 ---------------------------------
14736 function Expand_To_Stored_Constraint
14738 Constraint : Elist_Id) return Elist_Id
14740 Explicitly_Discriminated_Type : Entity_Id;
14741 Expansion : Elist_Id;
14742 Discriminant : Entity_Id;
14744 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
14745 -- Find the nearest type that actually specifies discriminants
14747 ---------------------------------
14748 -- Type_With_Explicit_Discrims --
14749 ---------------------------------
14751 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
14752 Typ : constant E := Base_Type (Id);
14755 if Ekind (Typ) in Incomplete_Or_Private_Kind then
14756 if Present (Full_View (Typ)) then
14757 return Type_With_Explicit_Discrims (Full_View (Typ));
14761 if Has_Discriminants (Typ) then
14766 if Etype (Typ) = Typ then
14768 elsif Has_Discriminants (Typ) then
14771 return Type_With_Explicit_Discrims (Etype (Typ));
14774 end Type_With_Explicit_Discrims;
14776 -- Start of processing for Expand_To_Stored_Constraint
14780 or else Is_Empty_Elmt_List (Constraint)
14785 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
14787 if No (Explicitly_Discriminated_Type) then
14791 Expansion := New_Elmt_List;
14794 First_Stored_Discriminant (Explicitly_Discriminated_Type);
14795 while Present (Discriminant) loop
14797 Get_Discriminant_Value (
14798 Discriminant, Explicitly_Discriminated_Type, Constraint),
14800 Next_Stored_Discriminant (Discriminant);
14804 end Expand_To_Stored_Constraint;
14806 ---------------------------
14807 -- Find_Hidden_Interface --
14808 ---------------------------
14810 function Find_Hidden_Interface
14812 Dest : Elist_Id) return Entity_Id
14815 Iface_Elmt : Elmt_Id;
14818 if Present (Src) and then Present (Dest) then
14819 Iface_Elmt := First_Elmt (Src);
14820 while Present (Iface_Elmt) loop
14821 Iface := Node (Iface_Elmt);
14823 if Is_Interface (Iface)
14824 and then not Contain_Interface (Iface, Dest)
14829 Next_Elmt (Iface_Elmt);
14834 end Find_Hidden_Interface;
14836 --------------------
14837 -- Find_Type_Name --
14838 --------------------
14840 function Find_Type_Name (N : Node_Id) return Entity_Id is
14841 Id : constant Entity_Id := Defining_Identifier (N);
14843 New_Id : Entity_Id;
14844 Prev_Par : Node_Id;
14846 procedure Tag_Mismatch;
14847 -- Diagnose a tagged partial view whose full view is untagged.
14848 -- We post the message on the full view, with a reference to
14849 -- the previous partial view. The partial view can be private
14850 -- or incomplete, and these are handled in a different manner,
14851 -- so we determine the position of the error message from the
14852 -- respective slocs of both.
14858 procedure Tag_Mismatch is
14860 if Sloc (Prev) < Sloc (Id) then
14861 if Ada_Version >= Ada_2012
14862 and then Nkind (N) = N_Private_Type_Declaration
14865 ("declaration of private } must be a tagged type ", Id, Prev);
14868 ("full declaration of } must be a tagged type ", Id, Prev);
14871 if Ada_Version >= Ada_2012
14872 and then Nkind (N) = N_Private_Type_Declaration
14875 ("declaration of private } must be a tagged type ", Prev, Id);
14878 ("full declaration of } must be a tagged type ", Prev, Id);
14883 -- Start of processing for Find_Type_Name
14886 -- Find incomplete declaration, if one was given
14888 Prev := Current_Entity_In_Scope (Id);
14890 -- New type declaration
14896 -- Previous declaration exists
14899 Prev_Par := Parent (Prev);
14901 -- Error if not incomplete/private case except if previous
14902 -- declaration is implicit, etc. Enter_Name will emit error if
14905 if not Is_Incomplete_Or_Private_Type (Prev) then
14909 -- Check invalid completion of private or incomplete type
14911 elsif not Nkind_In (N, N_Full_Type_Declaration,
14912 N_Task_Type_Declaration,
14913 N_Protected_Type_Declaration)
14915 (Ada_Version < Ada_2012
14916 or else not Is_Incomplete_Type (Prev)
14917 or else not Nkind_In (N, N_Private_Type_Declaration,
14918 N_Private_Extension_Declaration))
14920 -- Completion must be a full type declarations (RM 7.3(4))
14922 Error_Msg_Sloc := Sloc (Prev);
14923 Error_Msg_NE ("invalid completion of }", Id, Prev);
14925 -- Set scope of Id to avoid cascaded errors. Entity is never
14926 -- examined again, except when saving globals in generics.
14928 Set_Scope (Id, Current_Scope);
14931 -- If this is a repeated incomplete declaration, no further
14932 -- checks are possible.
14934 if Nkind (N) = N_Incomplete_Type_Declaration then
14938 -- Case of full declaration of incomplete type
14940 elsif Ekind (Prev) = E_Incomplete_Type
14941 and then (Ada_Version < Ada_2012
14942 or else No (Full_View (Prev))
14943 or else not Is_Private_Type (Full_View (Prev)))
14946 -- Indicate that the incomplete declaration has a matching full
14947 -- declaration. The defining occurrence of the incomplete
14948 -- declaration remains the visible one, and the procedure
14949 -- Get_Full_View dereferences it whenever the type is used.
14951 if Present (Full_View (Prev)) then
14952 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
14955 Set_Full_View (Prev, Id);
14956 Append_Entity (Id, Current_Scope);
14957 Set_Is_Public (Id, Is_Public (Prev));
14958 Set_Is_Internal (Id);
14961 -- If the incomplete view is tagged, a class_wide type has been
14962 -- created already. Use it for the private type as well, in order
14963 -- to prevent multiple incompatible class-wide types that may be
14964 -- created for self-referential anonymous access components.
14966 if Is_Tagged_Type (Prev)
14967 and then Present (Class_Wide_Type (Prev))
14969 Set_Ekind (Id, Ekind (Prev)); -- will be reset later
14970 Set_Class_Wide_Type (Id, Class_Wide_Type (Prev));
14971 Set_Etype (Class_Wide_Type (Id), Id);
14974 -- Case of full declaration of private type
14977 -- If the private type was a completion of an incomplete type then
14978 -- update Prev to reference the private type
14980 if Ada_Version >= Ada_2012
14981 and then Ekind (Prev) = E_Incomplete_Type
14982 and then Present (Full_View (Prev))
14983 and then Is_Private_Type (Full_View (Prev))
14985 Prev := Full_View (Prev);
14986 Prev_Par := Parent (Prev);
14989 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
14990 if Etype (Prev) /= Prev then
14992 -- Prev is a private subtype or a derived type, and needs
14995 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
14998 elsif Ekind (Prev) = E_Private_Type
14999 and then Nkind_In (N, N_Task_Type_Declaration,
15000 N_Protected_Type_Declaration)
15003 ("completion of nonlimited type cannot be limited", N);
15005 elsif Ekind (Prev) = E_Record_Type_With_Private
15006 and then Nkind_In (N, N_Task_Type_Declaration,
15007 N_Protected_Type_Declaration)
15009 if not Is_Limited_Record (Prev) then
15011 ("completion of nonlimited type cannot be limited", N);
15013 elsif No (Interface_List (N)) then
15015 ("completion of tagged private type must be tagged",
15019 elsif Nkind (N) = N_Full_Type_Declaration
15021 Nkind (Type_Definition (N)) = N_Record_Definition
15022 and then Interface_Present (Type_Definition (N))
15025 ("completion of private type cannot be an interface", N);
15028 -- Ada 2005 (AI-251): Private extension declaration of a task
15029 -- type or a protected type. This case arises when covering
15030 -- interface types.
15032 elsif Nkind_In (N, N_Task_Type_Declaration,
15033 N_Protected_Type_Declaration)
15037 elsif Nkind (N) /= N_Full_Type_Declaration
15038 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
15041 ("full view of private extension must be an extension", N);
15043 elsif not (Abstract_Present (Parent (Prev)))
15044 and then Abstract_Present (Type_Definition (N))
15047 ("full view of non-abstract extension cannot be abstract", N);
15050 if not In_Private_Part (Current_Scope) then
15052 ("declaration of full view must appear in private part", N);
15055 Copy_And_Swap (Prev, Id);
15056 Set_Has_Private_Declaration (Prev);
15057 Set_Has_Private_Declaration (Id);
15059 -- Preserve aspect and iterator flags that may have been set on
15060 -- the partial view.
15062 Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id));
15063 Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (Id));
15065 -- If no error, propagate freeze_node from private to full view.
15066 -- It may have been generated for an early operational item.
15068 if Present (Freeze_Node (Id))
15069 and then Serious_Errors_Detected = 0
15070 and then No (Full_View (Id))
15072 Set_Freeze_Node (Prev, Freeze_Node (Id));
15073 Set_Freeze_Node (Id, Empty);
15074 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
15077 Set_Full_View (Id, Prev);
15081 -- Verify that full declaration conforms to partial one
15083 if Is_Incomplete_Or_Private_Type (Prev)
15084 and then Present (Discriminant_Specifications (Prev_Par))
15086 if Present (Discriminant_Specifications (N)) then
15087 if Ekind (Prev) = E_Incomplete_Type then
15088 Check_Discriminant_Conformance (N, Prev, Prev);
15090 Check_Discriminant_Conformance (N, Prev, Id);
15095 ("missing discriminants in full type declaration", N);
15097 -- To avoid cascaded errors on subsequent use, share the
15098 -- discriminants of the partial view.
15100 Set_Discriminant_Specifications (N,
15101 Discriminant_Specifications (Prev_Par));
15105 -- A prior untagged partial view can have an associated class-wide
15106 -- type due to use of the class attribute, and in this case the full
15107 -- type must also be tagged. This Ada 95 usage is deprecated in favor
15108 -- of incomplete tagged declarations, but we check for it.
15111 and then (Is_Tagged_Type (Prev)
15112 or else Present (Class_Wide_Type (Prev)))
15114 -- Ada 2012 (AI05-0162): A private type may be the completion of
15115 -- an incomplete type
15117 if Ada_Version >= Ada_2012
15118 and then Is_Incomplete_Type (Prev)
15119 and then Nkind_In (N, N_Private_Type_Declaration,
15120 N_Private_Extension_Declaration)
15122 -- No need to check private extensions since they are tagged
15124 if Nkind (N) = N_Private_Type_Declaration
15125 and then not Tagged_Present (N)
15130 -- The full declaration is either a tagged type (including
15131 -- a synchronized type that implements interfaces) or a
15132 -- type extension, otherwise this is an error.
15134 elsif Nkind_In (N, N_Task_Type_Declaration,
15135 N_Protected_Type_Declaration)
15137 if No (Interface_List (N))
15138 and then not Error_Posted (N)
15143 elsif Nkind (Type_Definition (N)) = N_Record_Definition then
15145 -- Indicate that the previous declaration (tagged incomplete
15146 -- or private declaration) requires the same on the full one.
15148 if not Tagged_Present (Type_Definition (N)) then
15150 Set_Is_Tagged_Type (Id);
15153 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
15154 if No (Record_Extension_Part (Type_Definition (N))) then
15156 ("full declaration of } must be a record extension",
15159 -- Set some attributes to produce a usable full view
15161 Set_Is_Tagged_Type (Id);
15170 and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration
15171 and then Present (Premature_Use (Parent (Prev)))
15173 Error_Msg_Sloc := Sloc (N);
15175 ("\full declaration #", Premature_Use (Parent (Prev)));
15180 end Find_Type_Name;
15182 -------------------------
15183 -- Find_Type_Of_Object --
15184 -------------------------
15186 function Find_Type_Of_Object
15187 (Obj_Def : Node_Id;
15188 Related_Nod : Node_Id) return Entity_Id
15190 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
15191 P : Node_Id := Parent (Obj_Def);
15196 -- If the parent is a component_definition node we climb to the
15197 -- component_declaration node
15199 if Nkind (P) = N_Component_Definition then
15203 -- Case of an anonymous array subtype
15205 if Nkind_In (Def_Kind, N_Constrained_Array_Definition,
15206 N_Unconstrained_Array_Definition)
15209 Array_Type_Declaration (T, Obj_Def);
15211 -- Create an explicit subtype whenever possible
15213 elsif Nkind (P) /= N_Component_Declaration
15214 and then Def_Kind = N_Subtype_Indication
15216 -- Base name of subtype on object name, which will be unique in
15217 -- the current scope.
15219 -- If this is a duplicate declaration, return base type, to avoid
15220 -- generating duplicate anonymous types.
15222 if Error_Posted (P) then
15223 Analyze (Subtype_Mark (Obj_Def));
15224 return Entity (Subtype_Mark (Obj_Def));
15229 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
15231 T := Make_Defining_Identifier (Sloc (P), Nam);
15233 Insert_Action (Obj_Def,
15234 Make_Subtype_Declaration (Sloc (P),
15235 Defining_Identifier => T,
15236 Subtype_Indication => Relocate_Node (Obj_Def)));
15238 -- This subtype may need freezing, and this will not be done
15239 -- automatically if the object declaration is not in declarative
15240 -- part. Since this is an object declaration, the type cannot always
15241 -- be frozen here. Deferred constants do not freeze their type
15242 -- (which often enough will be private).
15244 if Nkind (P) = N_Object_Declaration
15245 and then Constant_Present (P)
15246 and then No (Expression (P))
15250 Insert_Actions (Obj_Def, Freeze_Entity (T, P));
15253 -- Ada 2005 AI-406: the object definition in an object declaration
15254 -- can be an access definition.
15256 elsif Def_Kind = N_Access_Definition then
15257 T := Access_Definition (Related_Nod, Obj_Def);
15259 Set_Is_Local_Anonymous_Access
15261 V => (Ada_Version < Ada_2012)
15262 or else (Nkind (P) /= N_Object_Declaration)
15263 or else Is_Library_Level_Entity (Defining_Identifier (P)));
15265 -- Otherwise, the object definition is just a subtype_mark
15268 T := Process_Subtype (Obj_Def, Related_Nod);
15270 -- If expansion is disabled an object definition that is an aggregate
15271 -- will not get expanded and may lead to scoping problems in the back
15272 -- end, if the object is referenced in an inner scope. In that case
15273 -- create an itype reference for the object definition now. This
15274 -- may be redundant in some cases, but harmless.
15277 and then Nkind (Related_Nod) = N_Object_Declaration
15280 Build_Itype_Reference (T, Related_Nod);
15285 end Find_Type_Of_Object;
15287 --------------------------------
15288 -- Find_Type_Of_Subtype_Indic --
15289 --------------------------------
15291 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
15295 -- Case of subtype mark with a constraint
15297 if Nkind (S) = N_Subtype_Indication then
15298 Find_Type (Subtype_Mark (S));
15299 Typ := Entity (Subtype_Mark (S));
15302 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
15305 ("incorrect constraint for this kind of type", Constraint (S));
15306 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
15309 -- Otherwise we have a subtype mark without a constraint
15311 elsif Error_Posted (S) then
15312 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
15320 -- Check No_Wide_Characters restriction
15322 Check_Wide_Character_Restriction (Typ, S);
15325 end Find_Type_Of_Subtype_Indic;
15327 -------------------------------------
15328 -- Floating_Point_Type_Declaration --
15329 -------------------------------------
15331 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
15332 Digs : constant Node_Id := Digits_Expression (Def);
15333 Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float);
15335 Base_Typ : Entity_Id;
15336 Implicit_Base : Entity_Id;
15339 function Can_Derive_From (E : Entity_Id) return Boolean;
15340 -- Find if given digits value, and possibly a specified range, allows
15341 -- derivation from specified type
15343 function Find_Base_Type return Entity_Id;
15344 -- Find a predefined base type that Def can derive from, or generate
15345 -- an error and substitute Long_Long_Float if none exists.
15347 ---------------------
15348 -- Can_Derive_From --
15349 ---------------------
15351 function Can_Derive_From (E : Entity_Id) return Boolean is
15352 Spec : constant Entity_Id := Real_Range_Specification (Def);
15355 -- Check specified "digits" constraint
15357 if Digs_Val > Digits_Value (E) then
15361 -- Avoid types not matching pragma Float_Representation, if present
15363 if (Opt.Float_Format = 'I' and then Float_Rep (E) /= IEEE_Binary)
15365 (Opt.Float_Format = 'V' and then Float_Rep (E) /= VAX_Native)
15370 -- Check for matching range, if specified
15372 if Present (Spec) then
15373 if Expr_Value_R (Type_Low_Bound (E)) >
15374 Expr_Value_R (Low_Bound (Spec))
15379 if Expr_Value_R (Type_High_Bound (E)) <
15380 Expr_Value_R (High_Bound (Spec))
15387 end Can_Derive_From;
15389 --------------------
15390 -- Find_Base_Type --
15391 --------------------
15393 function Find_Base_Type return Entity_Id is
15394 Choice : Elmt_Id := First_Elmt (Predefined_Float_Types);
15397 -- Iterate over the predefined types in order, returning the first
15398 -- one that Def can derive from.
15400 while Present (Choice) loop
15401 if Can_Derive_From (Node (Choice)) then
15402 return Node (Choice);
15405 Next_Elmt (Choice);
15408 -- If we can't derive from any existing type, use Long_Long_Float
15409 -- and give appropriate message explaining the problem.
15411 if Digs_Val > Max_Digs_Val then
15412 -- It might be the case that there is a type with the requested
15413 -- range, just not the combination of digits and range.
15416 ("no predefined type has requested range and precision",
15417 Real_Range_Specification (Def));
15421 ("range too large for any predefined type",
15422 Real_Range_Specification (Def));
15425 return Standard_Long_Long_Float;
15426 end Find_Base_Type;
15428 -- Start of processing for Floating_Point_Type_Declaration
15431 Check_Restriction (No_Floating_Point, Def);
15433 -- Create an implicit base type
15436 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
15438 -- Analyze and verify digits value
15440 Analyze_And_Resolve (Digs, Any_Integer);
15441 Check_Digits_Expression (Digs);
15442 Digs_Val := Expr_Value (Digs);
15444 -- Process possible range spec and find correct type to derive from
15446 Process_Real_Range_Specification (Def);
15448 -- Check that requested number of digits is not too high.
15450 if Digs_Val > Max_Digs_Val then
15451 -- The check for Max_Base_Digits may be somewhat expensive, as it
15452 -- requires reading System, so only do it when necessary.
15455 Max_Base_Digits : constant Uint :=
15458 (Parent (RTE (RE_Max_Base_Digits))));
15461 if Digs_Val > Max_Base_Digits then
15462 Error_Msg_Uint_1 := Max_Base_Digits;
15463 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
15465 elsif No (Real_Range_Specification (Def)) then
15466 Error_Msg_Uint_1 := Max_Digs_Val;
15467 Error_Msg_N ("types with more than ^ digits need range spec "
15468 & "(RM 3.5.7(6))", Digs);
15473 -- Find a suitable type to derive from or complain and use a substitute
15475 Base_Typ := Find_Base_Type;
15477 -- If there are bounds given in the declaration use them as the bounds
15478 -- of the type, otherwise use the bounds of the predefined base type
15479 -- that was chosen based on the Digits value.
15481 if Present (Real_Range_Specification (Def)) then
15482 Set_Scalar_Range (T, Real_Range_Specification (Def));
15483 Set_Is_Constrained (T);
15485 -- The bounds of this range must be converted to machine numbers
15486 -- in accordance with RM 4.9(38).
15488 Bound := Type_Low_Bound (T);
15490 if Nkind (Bound) = N_Real_Literal then
15492 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
15493 Set_Is_Machine_Number (Bound);
15496 Bound := Type_High_Bound (T);
15498 if Nkind (Bound) = N_Real_Literal then
15500 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
15501 Set_Is_Machine_Number (Bound);
15505 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
15508 -- Complete definition of implicit base and declared first subtype
15510 Set_Etype (Implicit_Base, Base_Typ);
15512 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
15513 Set_Size_Info (Implicit_Base, (Base_Typ));
15514 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
15515 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
15516 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
15517 Set_Float_Rep (Implicit_Base, Float_Rep (Base_Typ));
15519 Set_Ekind (T, E_Floating_Point_Subtype);
15520 Set_Etype (T, Implicit_Base);
15522 Set_Size_Info (T, (Implicit_Base));
15523 Set_RM_Size (T, RM_Size (Implicit_Base));
15524 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
15525 Set_Digits_Value (T, Digs_Val);
15526 end Floating_Point_Type_Declaration;
15528 ----------------------------
15529 -- Get_Discriminant_Value --
15530 ----------------------------
15532 -- This is the situation:
15534 -- There is a non-derived type
15536 -- type T0 (Dx, Dy, Dz...)
15538 -- There are zero or more levels of derivation, with each derivation
15539 -- either purely inheriting the discriminants, or defining its own.
15541 -- type Ti is new Ti-1
15543 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
15545 -- subtype Ti is ...
15547 -- The subtype issue is avoided by the use of Original_Record_Component,
15548 -- and the fact that derived subtypes also derive the constraints.
15550 -- This chain leads back from
15552 -- Typ_For_Constraint
15554 -- Typ_For_Constraint has discriminants, and the value for each
15555 -- discriminant is given by its corresponding Elmt of Constraints.
15557 -- Discriminant is some discriminant in this hierarchy
15559 -- We need to return its value
15561 -- We do this by recursively searching each level, and looking for
15562 -- Discriminant. Once we get to the bottom, we start backing up
15563 -- returning the value for it which may in turn be a discriminant
15564 -- further up, so on the backup we continue the substitution.
15566 function Get_Discriminant_Value
15567 (Discriminant : Entity_Id;
15568 Typ_For_Constraint : Entity_Id;
15569 Constraint : Elist_Id) return Node_Id
15571 function Search_Derivation_Levels
15573 Discrim_Values : Elist_Id;
15574 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
15575 -- This is the routine that performs the recursive search of levels
15576 -- as described above.
15578 ------------------------------
15579 -- Search_Derivation_Levels --
15580 ------------------------------
15582 function Search_Derivation_Levels
15584 Discrim_Values : Elist_Id;
15585 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
15589 Result : Node_Or_Entity_Id;
15590 Result_Entity : Node_Id;
15593 -- If inappropriate type, return Error, this happens only in
15594 -- cascaded error situations, and we want to avoid a blow up.
15596 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
15600 -- Look deeper if possible. Use Stored_Constraints only for
15601 -- untagged types. For tagged types use the given constraint.
15602 -- This asymmetry needs explanation???
15604 if not Stored_Discrim_Values
15605 and then Present (Stored_Constraint (Ti))
15606 and then not Is_Tagged_Type (Ti)
15609 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
15612 Td : constant Entity_Id := Etype (Ti);
15616 Result := Discriminant;
15619 if Present (Stored_Constraint (Ti)) then
15621 Search_Derivation_Levels
15622 (Td, Stored_Constraint (Ti), True);
15625 Search_Derivation_Levels
15626 (Td, Discrim_Values, Stored_Discrim_Values);
15632 -- Extra underlying places to search, if not found above. For
15633 -- concurrent types, the relevant discriminant appears in the
15634 -- corresponding record. For a type derived from a private type
15635 -- without discriminant, the full view inherits the discriminants
15636 -- of the full view of the parent.
15638 if Result = Discriminant then
15639 if Is_Concurrent_Type (Ti)
15640 and then Present (Corresponding_Record_Type (Ti))
15643 Search_Derivation_Levels (
15644 Corresponding_Record_Type (Ti),
15646 Stored_Discrim_Values);
15648 elsif Is_Private_Type (Ti)
15649 and then not Has_Discriminants (Ti)
15650 and then Present (Full_View (Ti))
15651 and then Etype (Full_View (Ti)) /= Ti
15654 Search_Derivation_Levels (
15657 Stored_Discrim_Values);
15661 -- If Result is not a (reference to a) discriminant, return it,
15662 -- otherwise set Result_Entity to the discriminant.
15664 if Nkind (Result) = N_Defining_Identifier then
15665 pragma Assert (Result = Discriminant);
15666 Result_Entity := Result;
15669 if not Denotes_Discriminant (Result) then
15673 Result_Entity := Entity (Result);
15676 -- See if this level of derivation actually has discriminants
15677 -- because tagged derivations can add them, hence the lower
15678 -- levels need not have any.
15680 if not Has_Discriminants (Ti) then
15684 -- Scan Ti's discriminants for Result_Entity,
15685 -- and return its corresponding value, if any.
15687 Result_Entity := Original_Record_Component (Result_Entity);
15689 Assoc := First_Elmt (Discrim_Values);
15691 if Stored_Discrim_Values then
15692 Disc := First_Stored_Discriminant (Ti);
15694 Disc := First_Discriminant (Ti);
15697 while Present (Disc) loop
15698 pragma Assert (Present (Assoc));
15700 if Original_Record_Component (Disc) = Result_Entity then
15701 return Node (Assoc);
15706 if Stored_Discrim_Values then
15707 Next_Stored_Discriminant (Disc);
15709 Next_Discriminant (Disc);
15713 -- Could not find it
15716 end Search_Derivation_Levels;
15720 Result : Node_Or_Entity_Id;
15722 -- Start of processing for Get_Discriminant_Value
15725 -- ??? This routine is a gigantic mess and will be deleted. For the
15726 -- time being just test for the trivial case before calling recurse.
15728 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
15734 D := First_Discriminant (Typ_For_Constraint);
15735 E := First_Elmt (Constraint);
15736 while Present (D) loop
15737 if Chars (D) = Chars (Discriminant) then
15741 Next_Discriminant (D);
15747 Result := Search_Derivation_Levels
15748 (Typ_For_Constraint, Constraint, False);
15750 -- ??? hack to disappear when this routine is gone
15752 if Nkind (Result) = N_Defining_Identifier then
15758 D := First_Discriminant (Typ_For_Constraint);
15759 E := First_Elmt (Constraint);
15760 while Present (D) loop
15761 if Corresponding_Discriminant (D) = Discriminant then
15765 Next_Discriminant (D);
15771 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
15773 end Get_Discriminant_Value;
15775 --------------------------
15776 -- Has_Range_Constraint --
15777 --------------------------
15779 function Has_Range_Constraint (N : Node_Id) return Boolean is
15780 C : constant Node_Id := Constraint (N);
15783 if Nkind (C) = N_Range_Constraint then
15786 elsif Nkind (C) = N_Digits_Constraint then
15788 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
15790 Present (Range_Constraint (C));
15792 elsif Nkind (C) = N_Delta_Constraint then
15793 return Present (Range_Constraint (C));
15798 end Has_Range_Constraint;
15800 ------------------------
15801 -- Inherit_Components --
15802 ------------------------
15804 function Inherit_Components
15806 Parent_Base : Entity_Id;
15807 Derived_Base : Entity_Id;
15808 Is_Tagged : Boolean;
15809 Inherit_Discr : Boolean;
15810 Discs : Elist_Id) return Elist_Id
15812 Assoc_List : constant Elist_Id := New_Elmt_List;
15814 procedure Inherit_Component
15815 (Old_C : Entity_Id;
15816 Plain_Discrim : Boolean := False;
15817 Stored_Discrim : Boolean := False);
15818 -- Inherits component Old_C from Parent_Base to the Derived_Base. If
15819 -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
15820 -- True, Old_C is a stored discriminant. If they are both false then
15821 -- Old_C is a regular component.
15823 -----------------------
15824 -- Inherit_Component --
15825 -----------------------
15827 procedure Inherit_Component
15828 (Old_C : Entity_Id;
15829 Plain_Discrim : Boolean := False;
15830 Stored_Discrim : Boolean := False)
15832 procedure Set_Anonymous_Type (Id : Entity_Id);
15833 -- Id denotes the entity of an access discriminant or anonymous
15834 -- access component. Set the type of Id to either the same type of
15835 -- Old_C or create a new one depending on whether the parent and
15836 -- the child types are in the same scope.
15838 ------------------------
15839 -- Set_Anonymous_Type --
15840 ------------------------
15842 procedure Set_Anonymous_Type (Id : Entity_Id) is
15843 Old_Typ : constant Entity_Id := Etype (Old_C);
15846 if Scope (Parent_Base) = Scope (Derived_Base) then
15847 Set_Etype (Id, Old_Typ);
15849 -- The parent and the derived type are in two different scopes.
15850 -- Reuse the type of the original discriminant / component by
15851 -- copying it in order to preserve all attributes.
15855 Typ : constant Entity_Id := New_Copy (Old_Typ);
15858 Set_Etype (Id, Typ);
15860 -- Since we do not generate component declarations for
15861 -- inherited components, associate the itype with the
15864 Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base));
15865 Set_Scope (Typ, Derived_Base);
15868 end Set_Anonymous_Type;
15870 -- Local variables and constants
15872 New_C : constant Entity_Id := New_Copy (Old_C);
15874 Corr_Discrim : Entity_Id;
15875 Discrim : Entity_Id;
15877 -- Start of processing for Inherit_Component
15880 pragma Assert (not Is_Tagged or else not Stored_Discrim);
15882 Set_Parent (New_C, Parent (Old_C));
15884 -- Regular discriminants and components must be inserted in the scope
15885 -- of the Derived_Base. Do it here.
15887 if not Stored_Discrim then
15888 Enter_Name (New_C);
15891 -- For tagged types the Original_Record_Component must point to
15892 -- whatever this field was pointing to in the parent type. This has
15893 -- already been achieved by the call to New_Copy above.
15895 if not Is_Tagged then
15896 Set_Original_Record_Component (New_C, New_C);
15899 -- Set the proper type of an access discriminant
15901 if Ekind (New_C) = E_Discriminant
15902 and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type
15904 Set_Anonymous_Type (New_C);
15907 -- If we have inherited a component then see if its Etype contains
15908 -- references to Parent_Base discriminants. In this case, replace
15909 -- these references with the constraints given in Discs. We do not
15910 -- do this for the partial view of private types because this is
15911 -- not needed (only the components of the full view will be used
15912 -- for code generation) and cause problem. We also avoid this
15913 -- transformation in some error situations.
15915 if Ekind (New_C) = E_Component then
15917 -- Set the proper type of an anonymous access component
15919 if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then
15920 Set_Anonymous_Type (New_C);
15922 elsif (Is_Private_Type (Derived_Base)
15923 and then not Is_Generic_Type (Derived_Base))
15924 or else (Is_Empty_Elmt_List (Discs)
15925 and then not Expander_Active)
15927 Set_Etype (New_C, Etype (Old_C));
15930 -- The current component introduces a circularity of the
15933 -- limited with Pack_2;
15934 -- package Pack_1 is
15935 -- type T_1 is tagged record
15936 -- Comp : access Pack_2.T_2;
15942 -- package Pack_2 is
15943 -- type T_2 is new Pack_1.T_1 with ...;
15948 Constrain_Component_Type
15949 (Old_C, Derived_Base, N, Parent_Base, Discs));
15953 -- In derived tagged types it is illegal to reference a non
15954 -- discriminant component in the parent type. To catch this, mark
15955 -- these components with an Ekind of E_Void. This will be reset in
15956 -- Record_Type_Definition after processing the record extension of
15957 -- the derived type.
15959 -- If the declaration is a private extension, there is no further
15960 -- record extension to process, and the components retain their
15961 -- current kind, because they are visible at this point.
15963 if Is_Tagged and then Ekind (New_C) = E_Component
15964 and then Nkind (N) /= N_Private_Extension_Declaration
15966 Set_Ekind (New_C, E_Void);
15969 if Plain_Discrim then
15970 Set_Corresponding_Discriminant (New_C, Old_C);
15971 Build_Discriminal (New_C);
15973 -- If we are explicitly inheriting a stored discriminant it will be
15974 -- completely hidden.
15976 elsif Stored_Discrim then
15977 Set_Corresponding_Discriminant (New_C, Empty);
15978 Set_Discriminal (New_C, Empty);
15979 Set_Is_Completely_Hidden (New_C);
15981 -- Set the Original_Record_Component of each discriminant in the
15982 -- derived base to point to the corresponding stored that we just
15985 Discrim := First_Discriminant (Derived_Base);
15986 while Present (Discrim) loop
15987 Corr_Discrim := Corresponding_Discriminant (Discrim);
15989 -- Corr_Discrim could be missing in an error situation
15991 if Present (Corr_Discrim)
15992 and then Original_Record_Component (Corr_Discrim) = Old_C
15994 Set_Original_Record_Component (Discrim, New_C);
15997 Next_Discriminant (Discrim);
16000 Append_Entity (New_C, Derived_Base);
16003 if not Is_Tagged then
16004 Append_Elmt (Old_C, Assoc_List);
16005 Append_Elmt (New_C, Assoc_List);
16007 end Inherit_Component;
16009 -- Variables local to Inherit_Component
16011 Loc : constant Source_Ptr := Sloc (N);
16013 Parent_Discrim : Entity_Id;
16014 Stored_Discrim : Entity_Id;
16016 Component : Entity_Id;
16018 -- Start of processing for Inherit_Components
16021 if not Is_Tagged then
16022 Append_Elmt (Parent_Base, Assoc_List);
16023 Append_Elmt (Derived_Base, Assoc_List);
16026 -- Inherit parent discriminants if needed
16028 if Inherit_Discr then
16029 Parent_Discrim := First_Discriminant (Parent_Base);
16030 while Present (Parent_Discrim) loop
16031 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
16032 Next_Discriminant (Parent_Discrim);
16036 -- Create explicit stored discrims for untagged types when necessary
16038 if not Has_Unknown_Discriminants (Derived_Base)
16039 and then Has_Discriminants (Parent_Base)
16040 and then not Is_Tagged
16043 or else First_Discriminant (Parent_Base) /=
16044 First_Stored_Discriminant (Parent_Base))
16046 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
16047 while Present (Stored_Discrim) loop
16048 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
16049 Next_Stored_Discriminant (Stored_Discrim);
16053 -- See if we can apply the second transformation for derived types, as
16054 -- explained in point 6. in the comments above Build_Derived_Record_Type
16055 -- This is achieved by appending Derived_Base discriminants into Discs,
16056 -- which has the side effect of returning a non empty Discs list to the
16057 -- caller of Inherit_Components, which is what we want. This must be
16058 -- done for private derived types if there are explicit stored
16059 -- discriminants, to ensure that we can retrieve the values of the
16060 -- constraints provided in the ancestors.
16063 and then Is_Empty_Elmt_List (Discs)
16064 and then Present (First_Discriminant (Derived_Base))
16066 (not Is_Private_Type (Derived_Base)
16067 or else Is_Completely_Hidden
16068 (First_Stored_Discriminant (Derived_Base))
16069 or else Is_Generic_Type (Derived_Base))
16071 D := First_Discriminant (Derived_Base);
16072 while Present (D) loop
16073 Append_Elmt (New_Reference_To (D, Loc), Discs);
16074 Next_Discriminant (D);
16078 -- Finally, inherit non-discriminant components unless they are not
16079 -- visible because defined or inherited from the full view of the
16080 -- parent. Don't inherit the _parent field of the parent type.
16082 Component := First_Entity (Parent_Base);
16083 while Present (Component) loop
16085 -- Ada 2005 (AI-251): Do not inherit components associated with
16086 -- secondary tags of the parent.
16088 if Ekind (Component) = E_Component
16089 and then Present (Related_Type (Component))
16093 elsif Ekind (Component) /= E_Component
16094 or else Chars (Component) = Name_uParent
16098 -- If the derived type is within the parent type's declarative
16099 -- region, then the components can still be inherited even though
16100 -- they aren't visible at this point. This can occur for cases
16101 -- such as within public child units where the components must
16102 -- become visible upon entering the child unit's private part.
16104 elsif not Is_Visible_Component (Component)
16105 and then not In_Open_Scopes (Scope (Parent_Base))
16109 elsif Ekind_In (Derived_Base, E_Private_Type,
16110 E_Limited_Private_Type)
16115 Inherit_Component (Component);
16118 Next_Entity (Component);
16121 -- For tagged derived types, inherited discriminants cannot be used in
16122 -- component declarations of the record extension part. To achieve this
16123 -- we mark the inherited discriminants as not visible.
16125 if Is_Tagged and then Inherit_Discr then
16126 D := First_Discriminant (Derived_Base);
16127 while Present (D) loop
16128 Set_Is_Immediately_Visible (D, False);
16129 Next_Discriminant (D);
16134 end Inherit_Components;
16136 -----------------------
16137 -- Is_Constant_Bound --
16138 -----------------------
16140 function Is_Constant_Bound (Exp : Node_Id) return Boolean is
16142 if Compile_Time_Known_Value (Exp) then
16145 elsif Is_Entity_Name (Exp)
16146 and then Present (Entity (Exp))
16148 return Is_Constant_Object (Entity (Exp))
16149 or else Ekind (Entity (Exp)) = E_Enumeration_Literal;
16151 elsif Nkind (Exp) in N_Binary_Op then
16152 return Is_Constant_Bound (Left_Opnd (Exp))
16153 and then Is_Constant_Bound (Right_Opnd (Exp))
16154 and then Scope (Entity (Exp)) = Standard_Standard;
16159 end Is_Constant_Bound;
16161 -----------------------
16162 -- Is_Null_Extension --
16163 -----------------------
16165 function Is_Null_Extension (T : Entity_Id) return Boolean is
16166 Type_Decl : constant Node_Id := Parent (Base_Type (T));
16167 Comp_List : Node_Id;
16171 if Nkind (Type_Decl) /= N_Full_Type_Declaration
16172 or else not Is_Tagged_Type (T)
16173 or else Nkind (Type_Definition (Type_Decl)) /=
16174 N_Derived_Type_Definition
16175 or else No (Record_Extension_Part (Type_Definition (Type_Decl)))
16181 Component_List (Record_Extension_Part (Type_Definition (Type_Decl)));
16183 if Present (Discriminant_Specifications (Type_Decl)) then
16186 elsif Present (Comp_List)
16187 and then Is_Non_Empty_List (Component_Items (Comp_List))
16189 Comp := First (Component_Items (Comp_List));
16191 -- Only user-defined components are relevant. The component list
16192 -- may also contain a parent component and internal components
16193 -- corresponding to secondary tags, but these do not determine
16194 -- whether this is a null extension.
16196 while Present (Comp) loop
16197 if Comes_From_Source (Comp) then
16208 end Is_Null_Extension;
16210 ------------------------------
16211 -- Is_Valid_Constraint_Kind --
16212 ------------------------------
16214 function Is_Valid_Constraint_Kind
16215 (T_Kind : Type_Kind;
16216 Constraint_Kind : Node_Kind) return Boolean
16220 when Enumeration_Kind |
16222 return Constraint_Kind = N_Range_Constraint;
16224 when Decimal_Fixed_Point_Kind =>
16225 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
16226 N_Range_Constraint);
16228 when Ordinary_Fixed_Point_Kind =>
16229 return Nkind_In (Constraint_Kind, N_Delta_Constraint,
16230 N_Range_Constraint);
16233 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
16234 N_Range_Constraint);
16241 E_Incomplete_Type |
16244 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
16247 return True; -- Error will be detected later
16249 end Is_Valid_Constraint_Kind;
16251 --------------------------
16252 -- Is_Visible_Component --
16253 --------------------------
16255 function Is_Visible_Component (C : Entity_Id) return Boolean is
16256 Original_Comp : Entity_Id := Empty;
16257 Original_Scope : Entity_Id;
16258 Type_Scope : Entity_Id;
16260 function Is_Local_Type (Typ : Entity_Id) return Boolean;
16261 -- Check whether parent type of inherited component is declared locally,
16262 -- possibly within a nested package or instance. The current scope is
16263 -- the derived record itself.
16265 -------------------
16266 -- Is_Local_Type --
16267 -------------------
16269 function Is_Local_Type (Typ : Entity_Id) return Boolean is
16273 Scop := Scope (Typ);
16274 while Present (Scop)
16275 and then Scop /= Standard_Standard
16277 if Scop = Scope (Current_Scope) then
16281 Scop := Scope (Scop);
16287 -- Start of processing for Is_Visible_Component
16290 if Ekind_In (C, E_Component, E_Discriminant) then
16291 Original_Comp := Original_Record_Component (C);
16294 if No (Original_Comp) then
16296 -- Premature usage, or previous error
16301 Original_Scope := Scope (Original_Comp);
16302 Type_Scope := Scope (Base_Type (Scope (C)));
16305 -- This test only concerns tagged types
16307 if not Is_Tagged_Type (Original_Scope) then
16310 -- If it is _Parent or _Tag, there is no visibility issue
16312 elsif not Comes_From_Source (Original_Comp) then
16315 -- Discriminants are always visible
16317 elsif Ekind (Original_Comp) = E_Discriminant
16318 and then not Has_Unknown_Discriminants (Original_Scope)
16322 -- In the body of an instantiation, no need to check for the visibility
16325 elsif In_Instance_Body then
16328 -- If the component has been declared in an ancestor which is currently
16329 -- a private type, then it is not visible. The same applies if the
16330 -- component's containing type is not in an open scope and the original
16331 -- component's enclosing type is a visible full view of a private type
16332 -- (which can occur in cases where an attempt is being made to reference
16333 -- a component in a sibling package that is inherited from a visible
16334 -- component of a type in an ancestor package; the component in the
16335 -- sibling package should not be visible even though the component it
16336 -- inherited from is visible). This does not apply however in the case
16337 -- where the scope of the type is a private child unit, or when the
16338 -- parent comes from a local package in which the ancestor is currently
16339 -- visible. The latter suppression of visibility is needed for cases
16340 -- that are tested in B730006.
16342 elsif Is_Private_Type (Original_Scope)
16344 (not Is_Private_Descendant (Type_Scope)
16345 and then not In_Open_Scopes (Type_Scope)
16346 and then Has_Private_Declaration (Original_Scope))
16348 -- If the type derives from an entity in a formal package, there
16349 -- are no additional visible components.
16351 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
16352 N_Formal_Package_Declaration
16356 -- if we are not in the private part of the current package, there
16357 -- are no additional visible components.
16359 elsif Ekind (Scope (Current_Scope)) = E_Package
16360 and then not In_Private_Part (Scope (Current_Scope))
16365 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
16366 and then In_Open_Scopes (Scope (Original_Scope))
16367 and then Is_Local_Type (Type_Scope);
16370 -- There is another weird way in which a component may be invisible
16371 -- when the private and the full view are not derived from the same
16372 -- ancestor. Here is an example :
16374 -- type A1 is tagged record F1 : integer; end record;
16375 -- type A2 is new A1 with record F2 : integer; end record;
16376 -- type T is new A1 with private;
16378 -- type T is new A2 with null record;
16380 -- In this case, the full view of T inherits F1 and F2 but the private
16381 -- view inherits only F1
16385 Ancestor : Entity_Id := Scope (C);
16389 if Ancestor = Original_Scope then
16391 elsif Ancestor = Etype (Ancestor) then
16395 Ancestor := Etype (Ancestor);
16399 end Is_Visible_Component;
16401 --------------------------
16402 -- Make_Class_Wide_Type --
16403 --------------------------
16405 procedure Make_Class_Wide_Type (T : Entity_Id) is
16406 CW_Type : Entity_Id;
16408 Next_E : Entity_Id;
16411 if Present (Class_Wide_Type (T)) then
16413 -- The class-wide type is a partially decorated entity created for a
16414 -- unanalyzed tagged type referenced through a limited with clause.
16415 -- When the tagged type is analyzed, its class-wide type needs to be
16416 -- redecorated. Note that we reuse the entity created by Decorate_
16417 -- Tagged_Type in order to preserve all links.
16419 if Materialize_Entity (Class_Wide_Type (T)) then
16420 CW_Type := Class_Wide_Type (T);
16421 Set_Materialize_Entity (CW_Type, False);
16423 -- The class wide type can have been defined by the partial view, in
16424 -- which case everything is already done.
16430 -- Default case, we need to create a new class-wide type
16434 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
16437 -- Inherit root type characteristics
16439 CW_Name := Chars (CW_Type);
16440 Next_E := Next_Entity (CW_Type);
16441 Copy_Node (T, CW_Type);
16442 Set_Comes_From_Source (CW_Type, False);
16443 Set_Chars (CW_Type, CW_Name);
16444 Set_Parent (CW_Type, Parent (T));
16445 Set_Next_Entity (CW_Type, Next_E);
16447 -- Ensure we have a new freeze node for the class-wide type. The partial
16448 -- view may have freeze action of its own, requiring a proper freeze
16449 -- node, and the same freeze node cannot be shared between the two
16452 Set_Has_Delayed_Freeze (CW_Type);
16453 Set_Freeze_Node (CW_Type, Empty);
16455 -- Customize the class-wide type: It has no prim. op., it cannot be
16456 -- abstract and its Etype points back to the specific root type.
16458 Set_Ekind (CW_Type, E_Class_Wide_Type);
16459 Set_Is_Tagged_Type (CW_Type, True);
16460 Set_Direct_Primitive_Operations (CW_Type, New_Elmt_List);
16461 Set_Is_Abstract_Type (CW_Type, False);
16462 Set_Is_Constrained (CW_Type, False);
16463 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
16465 if Ekind (T) = E_Class_Wide_Subtype then
16466 Set_Etype (CW_Type, Etype (Base_Type (T)));
16468 Set_Etype (CW_Type, T);
16471 -- If this is the class_wide type of a constrained subtype, it does
16472 -- not have discriminants.
16474 Set_Has_Discriminants (CW_Type,
16475 Has_Discriminants (T) and then not Is_Constrained (T));
16477 Set_Has_Unknown_Discriminants (CW_Type, True);
16478 Set_Class_Wide_Type (T, CW_Type);
16479 Set_Equivalent_Type (CW_Type, Empty);
16481 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
16483 Set_Class_Wide_Type (CW_Type, CW_Type);
16484 end Make_Class_Wide_Type;
16490 procedure Make_Index
16492 Related_Nod : Node_Id;
16493 Related_Id : Entity_Id := Empty;
16494 Suffix_Index : Nat := 1;
16495 In_Iter_Schm : Boolean := False)
16499 Def_Id : Entity_Id := Empty;
16500 Found : Boolean := False;
16503 -- For a discrete range used in a constrained array definition and
16504 -- defined by a range, an implicit conversion to the predefined type
16505 -- INTEGER is assumed if each bound is either a numeric literal, a named
16506 -- number, or an attribute, and the type of both bounds (prior to the
16507 -- implicit conversion) is the type universal_integer. Otherwise, both
16508 -- bounds must be of the same discrete type, other than universal
16509 -- integer; this type must be determinable independently of the
16510 -- context, but using the fact that the type must be discrete and that
16511 -- both bounds must have the same type.
16513 -- Character literals also have a universal type in the absence of
16514 -- of additional context, and are resolved to Standard_Character.
16516 if Nkind (I) = N_Range then
16518 -- The index is given by a range constraint. The bounds are known
16519 -- to be of a consistent type.
16521 if not Is_Overloaded (I) then
16524 -- For universal bounds, choose the specific predefined type
16526 if T = Universal_Integer then
16527 T := Standard_Integer;
16529 elsif T = Any_Character then
16530 Ambiguous_Character (Low_Bound (I));
16532 T := Standard_Character;
16535 -- The node may be overloaded because some user-defined operators
16536 -- are available, but if a universal interpretation exists it is
16537 -- also the selected one.
16539 elsif Universal_Interpretation (I) = Universal_Integer then
16540 T := Standard_Integer;
16546 Ind : Interp_Index;
16550 Get_First_Interp (I, Ind, It);
16551 while Present (It.Typ) loop
16552 if Is_Discrete_Type (It.Typ) then
16555 and then not Covers (It.Typ, T)
16556 and then not Covers (T, It.Typ)
16558 Error_Msg_N ("ambiguous bounds in discrete range", I);
16566 Get_Next_Interp (Ind, It);
16569 if T = Any_Type then
16570 Error_Msg_N ("discrete type required for range", I);
16571 Set_Etype (I, Any_Type);
16574 elsif T = Universal_Integer then
16575 T := Standard_Integer;
16580 if not Is_Discrete_Type (T) then
16581 Error_Msg_N ("discrete type required for range", I);
16582 Set_Etype (I, Any_Type);
16586 if Nkind (Low_Bound (I)) = N_Attribute_Reference
16587 and then Attribute_Name (Low_Bound (I)) = Name_First
16588 and then Is_Entity_Name (Prefix (Low_Bound (I)))
16589 and then Is_Type (Entity (Prefix (Low_Bound (I))))
16590 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I))))
16592 -- The type of the index will be the type of the prefix, as long
16593 -- as the upper bound is 'Last of the same type.
16595 Def_Id := Entity (Prefix (Low_Bound (I)));
16597 if Nkind (High_Bound (I)) /= N_Attribute_Reference
16598 or else Attribute_Name (High_Bound (I)) /= Name_Last
16599 or else not Is_Entity_Name (Prefix (High_Bound (I)))
16600 or else Entity (Prefix (High_Bound (I))) /= Def_Id
16607 Process_Range_Expr_In_Decl (R, T, In_Iter_Schm => In_Iter_Schm);
16609 elsif Nkind (I) = N_Subtype_Indication then
16611 -- The index is given by a subtype with a range constraint
16613 T := Base_Type (Entity (Subtype_Mark (I)));
16615 if not Is_Discrete_Type (T) then
16616 Error_Msg_N ("discrete type required for range", I);
16617 Set_Etype (I, Any_Type);
16621 R := Range_Expression (Constraint (I));
16624 Process_Range_Expr_In_Decl
16625 (R, Entity (Subtype_Mark (I)), In_Iter_Schm => In_Iter_Schm);
16627 elsif Nkind (I) = N_Attribute_Reference then
16629 -- The parser guarantees that the attribute is a RANGE attribute
16631 -- If the node denotes the range of a type mark, that is also the
16632 -- resulting type, and we do no need to create an Itype for it.
16634 if Is_Entity_Name (Prefix (I))
16635 and then Comes_From_Source (I)
16636 and then Is_Type (Entity (Prefix (I)))
16637 and then Is_Discrete_Type (Entity (Prefix (I)))
16639 Def_Id := Entity (Prefix (I));
16642 Analyze_And_Resolve (I);
16646 -- If none of the above, must be a subtype. We convert this to a
16647 -- range attribute reference because in the case of declared first
16648 -- named subtypes, the types in the range reference can be different
16649 -- from the type of the entity. A range attribute normalizes the
16650 -- reference and obtains the correct types for the bounds.
16652 -- This transformation is in the nature of an expansion, is only
16653 -- done if expansion is active. In particular, it is not done on
16654 -- formal generic types, because we need to retain the name of the
16655 -- original index for instantiation purposes.
16658 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
16659 Error_Msg_N ("invalid subtype mark in discrete range ", I);
16660 Set_Etype (I, Any_Integer);
16664 -- The type mark may be that of an incomplete type. It is only
16665 -- now that we can get the full view, previous analysis does
16666 -- not look specifically for a type mark.
16668 Set_Entity (I, Get_Full_View (Entity (I)));
16669 Set_Etype (I, Entity (I));
16670 Def_Id := Entity (I);
16672 if not Is_Discrete_Type (Def_Id) then
16673 Error_Msg_N ("discrete type required for index", I);
16674 Set_Etype (I, Any_Type);
16679 if Expander_Active then
16681 Make_Attribute_Reference (Sloc (I),
16682 Attribute_Name => Name_Range,
16683 Prefix => Relocate_Node (I)));
16685 -- The original was a subtype mark that does not freeze. This
16686 -- means that the rewritten version must not freeze either.
16688 Set_Must_Not_Freeze (I);
16689 Set_Must_Not_Freeze (Prefix (I));
16691 -- Is order critical??? if so, document why, if not
16692 -- use Analyze_And_Resolve
16694 Analyze_And_Resolve (I);
16698 -- If expander is inactive, type is legal, nothing else to construct
16705 if not Is_Discrete_Type (T) then
16706 Error_Msg_N ("discrete type required for range", I);
16707 Set_Etype (I, Any_Type);
16710 elsif T = Any_Type then
16711 Set_Etype (I, Any_Type);
16715 -- We will now create the appropriate Itype to describe the range, but
16716 -- first a check. If we originally had a subtype, then we just label
16717 -- the range with this subtype. Not only is there no need to construct
16718 -- a new subtype, but it is wrong to do so for two reasons:
16720 -- 1. A legality concern, if we have a subtype, it must not freeze,
16721 -- and the Itype would cause freezing incorrectly
16723 -- 2. An efficiency concern, if we created an Itype, it would not be
16724 -- recognized as the same type for the purposes of eliminating
16725 -- checks in some circumstances.
16727 -- We signal this case by setting the subtype entity in Def_Id
16729 if No (Def_Id) then
16731 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
16732 Set_Etype (Def_Id, Base_Type (T));
16734 if Is_Signed_Integer_Type (T) then
16735 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
16737 elsif Is_Modular_Integer_Type (T) then
16738 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
16741 Set_Ekind (Def_Id, E_Enumeration_Subtype);
16742 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
16743 Set_First_Literal (Def_Id, First_Literal (T));
16746 Set_Size_Info (Def_Id, (T));
16747 Set_RM_Size (Def_Id, RM_Size (T));
16748 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
16750 Set_Scalar_Range (Def_Id, R);
16751 Conditional_Delay (Def_Id, T);
16753 -- In the subtype indication case, if the immediate parent of the
16754 -- new subtype is non-static, then the subtype we create is non-
16755 -- static, even if its bounds are static.
16757 if Nkind (I) = N_Subtype_Indication
16758 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
16760 Set_Is_Non_Static_Subtype (Def_Id);
16764 -- Final step is to label the index with this constructed type
16766 Set_Etype (I, Def_Id);
16769 ------------------------------
16770 -- Modular_Type_Declaration --
16771 ------------------------------
16773 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
16774 Mod_Expr : constant Node_Id := Expression (Def);
16777 procedure Set_Modular_Size (Bits : Int);
16778 -- Sets RM_Size to Bits, and Esize to normal word size above this
16780 ----------------------
16781 -- Set_Modular_Size --
16782 ----------------------
16784 procedure Set_Modular_Size (Bits : Int) is
16786 Set_RM_Size (T, UI_From_Int (Bits));
16791 elsif Bits <= 16 then
16792 Init_Esize (T, 16);
16794 elsif Bits <= 32 then
16795 Init_Esize (T, 32);
16798 Init_Esize (T, System_Max_Binary_Modulus_Power);
16801 if not Non_Binary_Modulus (T)
16802 and then Esize (T) = RM_Size (T)
16804 Set_Is_Known_Valid (T);
16806 end Set_Modular_Size;
16808 -- Start of processing for Modular_Type_Declaration
16811 -- If the mod expression is (exactly) 2 * literal, where literal is
16812 -- 64 or less,then almost certainly the * was meant to be **. Warn!
16814 if Warn_On_Suspicious_Modulus_Value
16815 and then Nkind (Mod_Expr) = N_Op_Multiply
16816 and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal
16817 and then Intval (Left_Opnd (Mod_Expr)) = Uint_2
16818 and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal
16819 and then Intval (Right_Opnd (Mod_Expr)) <= Uint_64
16821 Error_Msg_N ("suspicious MOD value, was '*'* intended'??", Mod_Expr);
16824 -- Proceed with analysis of mod expression
16826 Analyze_And_Resolve (Mod_Expr, Any_Integer);
16828 Set_Ekind (T, E_Modular_Integer_Type);
16829 Init_Alignment (T);
16830 Set_Is_Constrained (T);
16832 if not Is_OK_Static_Expression (Mod_Expr) then
16833 Flag_Non_Static_Expr
16834 ("non-static expression used for modular type bound!", Mod_Expr);
16835 M_Val := 2 ** System_Max_Binary_Modulus_Power;
16837 M_Val := Expr_Value (Mod_Expr);
16841 Error_Msg_N ("modulus value must be positive", Mod_Expr);
16842 M_Val := 2 ** System_Max_Binary_Modulus_Power;
16845 Set_Modulus (T, M_Val);
16847 -- Create bounds for the modular type based on the modulus given in
16848 -- the type declaration and then analyze and resolve those bounds.
16850 Set_Scalar_Range (T,
16851 Make_Range (Sloc (Mod_Expr),
16852 Low_Bound => Make_Integer_Literal (Sloc (Mod_Expr), 0),
16853 High_Bound => Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
16855 -- Properly analyze the literals for the range. We do this manually
16856 -- because we can't go calling Resolve, since we are resolving these
16857 -- bounds with the type, and this type is certainly not complete yet!
16859 Set_Etype (Low_Bound (Scalar_Range (T)), T);
16860 Set_Etype (High_Bound (Scalar_Range (T)), T);
16861 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
16862 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
16864 -- Loop through powers of two to find number of bits required
16866 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
16870 if M_Val = 2 ** Bits then
16871 Set_Modular_Size (Bits);
16876 elsif M_Val < 2 ** Bits then
16877 Check_SPARK_Restriction ("modulus should be a power of 2", T);
16878 Set_Non_Binary_Modulus (T);
16880 if Bits > System_Max_Nonbinary_Modulus_Power then
16881 Error_Msg_Uint_1 :=
16882 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
16884 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
16885 Set_Modular_Size (System_Max_Binary_Modulus_Power);
16889 -- In the non-binary case, set size as per RM 13.3(55)
16891 Set_Modular_Size (Bits);
16898 -- If we fall through, then the size exceed System.Max_Binary_Modulus
16899 -- so we just signal an error and set the maximum size.
16901 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
16902 Error_Msg_F ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
16904 Set_Modular_Size (System_Max_Binary_Modulus_Power);
16905 Init_Alignment (T);
16907 end Modular_Type_Declaration;
16909 --------------------------
16910 -- New_Concatenation_Op --
16911 --------------------------
16913 procedure New_Concatenation_Op (Typ : Entity_Id) is
16914 Loc : constant Source_Ptr := Sloc (Typ);
16917 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
16918 -- Create abbreviated declaration for the formal of a predefined
16919 -- Operator 'Op' of type 'Typ'
16921 --------------------
16922 -- Make_Op_Formal --
16923 --------------------
16925 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
16926 Formal : Entity_Id;
16928 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
16929 Set_Etype (Formal, Typ);
16930 Set_Mechanism (Formal, Default_Mechanism);
16932 end Make_Op_Formal;
16934 -- Start of processing for New_Concatenation_Op
16937 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
16939 Set_Ekind (Op, E_Operator);
16940 Set_Scope (Op, Current_Scope);
16941 Set_Etype (Op, Typ);
16942 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
16943 Set_Is_Immediately_Visible (Op);
16944 Set_Is_Intrinsic_Subprogram (Op);
16945 Set_Has_Completion (Op);
16946 Append_Entity (Op, Current_Scope);
16948 Set_Name_Entity_Id (Name_Op_Concat, Op);
16950 Append_Entity (Make_Op_Formal (Typ, Op), Op);
16951 Append_Entity (Make_Op_Formal (Typ, Op), Op);
16952 end New_Concatenation_Op;
16954 -------------------------
16955 -- OK_For_Limited_Init --
16956 -------------------------
16958 -- ???Check all calls of this, and compare the conditions under which it's
16961 function OK_For_Limited_Init
16963 Exp : Node_Id) return Boolean
16966 return Is_CPP_Constructor_Call (Exp)
16967 or else (Ada_Version >= Ada_2005
16968 and then not Debug_Flag_Dot_L
16969 and then OK_For_Limited_Init_In_05 (Typ, Exp));
16970 end OK_For_Limited_Init;
16972 -------------------------------
16973 -- OK_For_Limited_Init_In_05 --
16974 -------------------------------
16976 function OK_For_Limited_Init_In_05
16978 Exp : Node_Id) return Boolean
16981 -- An object of a limited interface type can be initialized with any
16982 -- expression of a nonlimited descendant type.
16984 if Is_Class_Wide_Type (Typ)
16985 and then Is_Limited_Interface (Typ)
16986 and then not Is_Limited_Type (Etype (Exp))
16991 -- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in
16992 -- case of limited aggregates (including extension aggregates), and
16993 -- function calls. The function call may have been given in prefixed
16994 -- notation, in which case the original node is an indexed component.
16995 -- If the function is parameterless, the original node was an explicit
16996 -- dereference. The function may also be parameterless, in which case
16997 -- the source node is just an identifier.
16999 case Nkind (Original_Node (Exp)) is
17000 when N_Aggregate | N_Extension_Aggregate | N_Function_Call | N_Op =>
17003 when N_Identifier =>
17004 return Present (Entity (Original_Node (Exp)))
17005 and then Ekind (Entity (Original_Node (Exp))) = E_Function;
17007 when N_Qualified_Expression =>
17009 OK_For_Limited_Init_In_05
17010 (Typ, Expression (Original_Node (Exp)));
17012 -- Ada 2005 (AI-251): If a class-wide interface object is initialized
17013 -- with a function call, the expander has rewritten the call into an
17014 -- N_Type_Conversion node to force displacement of the pointer to
17015 -- reference the component containing the secondary dispatch table.
17016 -- Otherwise a type conversion is not a legal context.
17017 -- A return statement for a build-in-place function returning a
17018 -- synchronized type also introduces an unchecked conversion.
17020 when N_Type_Conversion |
17021 N_Unchecked_Type_Conversion =>
17022 return not Comes_From_Source (Exp)
17024 OK_For_Limited_Init_In_05
17025 (Typ, Expression (Original_Node (Exp)));
17027 when N_Indexed_Component |
17028 N_Selected_Component |
17029 N_Explicit_Dereference =>
17030 return Nkind (Exp) = N_Function_Call;
17032 -- A use of 'Input is a function call, hence allowed. Normally the
17033 -- attribute will be changed to a call, but the attribute by itself
17034 -- can occur with -gnatc.
17036 when N_Attribute_Reference =>
17037 return Attribute_Name (Original_Node (Exp)) = Name_Input;
17039 -- For a conditional expression, all dependent expressions must be
17040 -- legal constructs.
17042 when N_Conditional_Expression =>
17044 Then_Expr : constant Node_Id :=
17045 Next (First (Expressions (Original_Node (Exp))));
17046 Else_Expr : constant Node_Id := Next (Then_Expr);
17048 return OK_For_Limited_Init_In_05 (Typ, Then_Expr)
17049 and then OK_For_Limited_Init_In_05 (Typ, Else_Expr);
17052 when N_Case_Expression =>
17057 Alt := First (Alternatives (Original_Node (Exp)));
17058 while Present (Alt) loop
17059 if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then
17072 end OK_For_Limited_Init_In_05;
17074 -------------------------------------------
17075 -- Ordinary_Fixed_Point_Type_Declaration --
17076 -------------------------------------------
17078 procedure Ordinary_Fixed_Point_Type_Declaration
17082 Loc : constant Source_Ptr := Sloc (Def);
17083 Delta_Expr : constant Node_Id := Delta_Expression (Def);
17084 RRS : constant Node_Id := Real_Range_Specification (Def);
17085 Implicit_Base : Entity_Id;
17092 Check_Restriction (No_Fixed_Point, Def);
17094 -- Create implicit base type
17097 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
17098 Set_Etype (Implicit_Base, Implicit_Base);
17100 -- Analyze and process delta expression
17102 Analyze_And_Resolve (Delta_Expr, Any_Real);
17104 Check_Delta_Expression (Delta_Expr);
17105 Delta_Val := Expr_Value_R (Delta_Expr);
17107 Set_Delta_Value (Implicit_Base, Delta_Val);
17109 -- Compute default small from given delta, which is the largest power
17110 -- of two that does not exceed the given delta value.
17120 if Delta_Val < Ureal_1 then
17121 while Delta_Val < Tmp loop
17122 Tmp := Tmp / Ureal_2;
17123 Scale := Scale + 1;
17128 Tmp := Tmp * Ureal_2;
17129 exit when Tmp > Delta_Val;
17130 Scale := Scale - 1;
17134 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
17137 Set_Small_Value (Implicit_Base, Small_Val);
17139 -- If no range was given, set a dummy range
17141 if RRS <= Empty_Or_Error then
17142 Low_Val := -Small_Val;
17143 High_Val := Small_Val;
17145 -- Otherwise analyze and process given range
17149 Low : constant Node_Id := Low_Bound (RRS);
17150 High : constant Node_Id := High_Bound (RRS);
17153 Analyze_And_Resolve (Low, Any_Real);
17154 Analyze_And_Resolve (High, Any_Real);
17155 Check_Real_Bound (Low);
17156 Check_Real_Bound (High);
17158 -- Obtain and set the range
17160 Low_Val := Expr_Value_R (Low);
17161 High_Val := Expr_Value_R (High);
17163 if Low_Val > High_Val then
17164 Error_Msg_NE ("?fixed point type& has null range", Def, T);
17169 -- The range for both the implicit base and the declared first subtype
17170 -- cannot be set yet, so we use the special routine Set_Fixed_Range to
17171 -- set a temporary range in place. Note that the bounds of the base
17172 -- type will be widened to be symmetrical and to fill the available
17173 -- bits when the type is frozen.
17175 -- We could do this with all discrete types, and probably should, but
17176 -- we absolutely have to do it for fixed-point, since the end-points
17177 -- of the range and the size are determined by the small value, which
17178 -- could be reset before the freeze point.
17180 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
17181 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
17183 -- Complete definition of first subtype
17185 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
17186 Set_Etype (T, Implicit_Base);
17187 Init_Size_Align (T);
17188 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
17189 Set_Small_Value (T, Small_Val);
17190 Set_Delta_Value (T, Delta_Val);
17191 Set_Is_Constrained (T);
17193 end Ordinary_Fixed_Point_Type_Declaration;
17195 ----------------------------------------
17196 -- Prepare_Private_Subtype_Completion --
17197 ----------------------------------------
17199 procedure Prepare_Private_Subtype_Completion
17201 Related_Nod : Node_Id)
17203 Id_B : constant Entity_Id := Base_Type (Id);
17204 Full_B : constant Entity_Id := Full_View (Id_B);
17208 if Present (Full_B) then
17210 -- The Base_Type is already completed, we can complete the subtype
17211 -- now. We have to create a new entity with the same name, Thus we
17212 -- can't use Create_Itype.
17214 -- This is messy, should be fixed ???
17216 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
17217 Set_Is_Itype (Full);
17218 Set_Associated_Node_For_Itype (Full, Related_Nod);
17219 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
17222 -- The parent subtype may be private, but the base might not, in some
17223 -- nested instances. In that case, the subtype does not need to be
17224 -- exchanged. It would still be nice to make private subtypes and their
17225 -- bases consistent at all times ???
17227 if Is_Private_Type (Id_B) then
17228 Append_Elmt (Id, Private_Dependents (Id_B));
17231 end Prepare_Private_Subtype_Completion;
17233 ---------------------------
17234 -- Process_Discriminants --
17235 ---------------------------
17237 procedure Process_Discriminants
17239 Prev : Entity_Id := Empty)
17241 Elist : constant Elist_Id := New_Elmt_List;
17244 Discr_Number : Uint;
17245 Discr_Type : Entity_Id;
17246 Default_Present : Boolean := False;
17247 Default_Not_Present : Boolean := False;
17250 -- A composite type other than an array type can have discriminants.
17251 -- On entry, the current scope is the composite type.
17253 -- The discriminants are initially entered into the scope of the type
17254 -- via Enter_Name with the default Ekind of E_Void to prevent premature
17255 -- use, as explained at the end of this procedure.
17257 Discr := First (Discriminant_Specifications (N));
17258 while Present (Discr) loop
17259 Enter_Name (Defining_Identifier (Discr));
17261 -- For navigation purposes we add a reference to the discriminant
17262 -- in the entity for the type. If the current declaration is a
17263 -- completion, place references on the partial view. Otherwise the
17264 -- type is the current scope.
17266 if Present (Prev) then
17268 -- The references go on the partial view, if present. If the
17269 -- partial view has discriminants, the references have been
17270 -- generated already.
17272 if not Has_Discriminants (Prev) then
17273 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
17277 (Current_Scope, Defining_Identifier (Discr), 'd');
17280 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
17281 Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr));
17283 -- Ada 2005 (AI-254)
17285 if Present (Access_To_Subprogram_Definition
17286 (Discriminant_Type (Discr)))
17287 and then Protected_Present (Access_To_Subprogram_Definition
17288 (Discriminant_Type (Discr)))
17291 Replace_Anonymous_Access_To_Protected_Subprogram (Discr);
17295 Find_Type (Discriminant_Type (Discr));
17296 Discr_Type := Etype (Discriminant_Type (Discr));
17298 if Error_Posted (Discriminant_Type (Discr)) then
17299 Discr_Type := Any_Type;
17303 if Is_Access_Type (Discr_Type) then
17305 -- Ada 2005 (AI-230): Access discriminant allowed in non-limited
17308 if Ada_Version < Ada_2005 then
17309 Check_Access_Discriminant_Requires_Limited
17310 (Discr, Discriminant_Type (Discr));
17313 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
17315 ("(Ada 83) access discriminant not allowed", Discr);
17318 elsif not Is_Discrete_Type (Discr_Type) then
17319 Error_Msg_N ("discriminants must have a discrete or access type",
17320 Discriminant_Type (Discr));
17323 Set_Etype (Defining_Identifier (Discr), Discr_Type);
17325 -- If a discriminant specification includes the assignment compound
17326 -- delimiter followed by an expression, the expression is the default
17327 -- expression of the discriminant; the default expression must be of
17328 -- the type of the discriminant. (RM 3.7.1) Since this expression is
17329 -- a default expression, we do the special preanalysis, since this
17330 -- expression does not freeze (see "Handling of Default and Per-
17331 -- Object Expressions" in spec of package Sem).
17333 if Present (Expression (Discr)) then
17334 Preanalyze_Spec_Expression (Expression (Discr), Discr_Type);
17336 if Nkind (N) = N_Formal_Type_Declaration then
17338 ("discriminant defaults not allowed for formal type",
17339 Expression (Discr));
17341 -- Flag an error for a tagged type with defaulted discriminants,
17342 -- excluding limited tagged types when compiling for Ada 2012
17343 -- (see AI05-0214).
17345 elsif Is_Tagged_Type (Current_Scope)
17346 and then (not Is_Limited_Type (Current_Scope)
17347 or else Ada_Version < Ada_2012)
17348 and then Comes_From_Source (N)
17350 -- Note: see similar test in Check_Or_Process_Discriminants, to
17351 -- handle the (illegal) case of the completion of an untagged
17352 -- view with discriminants with defaults by a tagged full view.
17353 -- We skip the check if Discr does not come from source, to
17354 -- account for the case of an untagged derived type providing
17355 -- defaults for a renamed discriminant from a private untagged
17356 -- ancestor with a tagged full view (ACATS B460006).
17358 if Ada_Version >= Ada_2012 then
17360 ("discriminants of nonlimited tagged type cannot have"
17362 Expression (Discr));
17365 ("discriminants of tagged type cannot have defaults",
17366 Expression (Discr));
17370 Default_Present := True;
17371 Append_Elmt (Expression (Discr), Elist);
17373 -- Tag the defining identifiers for the discriminants with
17374 -- their corresponding default expressions from the tree.
17376 Set_Discriminant_Default_Value
17377 (Defining_Identifier (Discr), Expression (Discr));
17381 Default_Not_Present := True;
17384 -- Ada 2005 (AI-231): Create an Itype that is a duplicate of
17385 -- Discr_Type but with the null-exclusion attribute
17387 if Ada_Version >= Ada_2005 then
17389 -- Ada 2005 (AI-231): Static checks
17391 if Can_Never_Be_Null (Discr_Type) then
17392 Null_Exclusion_Static_Checks (Discr);
17394 elsif Is_Access_Type (Discr_Type)
17395 and then Null_Exclusion_Present (Discr)
17397 -- No need to check itypes because in their case this check
17398 -- was done at their point of creation
17400 and then not Is_Itype (Discr_Type)
17402 if Can_Never_Be_Null (Discr_Type) then
17404 ("`NOT NULL` not allowed (& already excludes null)",
17409 Set_Etype (Defining_Identifier (Discr),
17410 Create_Null_Excluding_Itype
17412 Related_Nod => Discr));
17414 -- Check for improper null exclusion if the type is otherwise
17415 -- legal for a discriminant.
17417 elsif Null_Exclusion_Present (Discr)
17418 and then Is_Discrete_Type (Discr_Type)
17421 ("null exclusion can only apply to an access type", Discr);
17424 -- Ada 2005 (AI-402): access discriminants of nonlimited types
17425 -- can't have defaults. Synchronized types, or types that are
17426 -- explicitly limited are fine, but special tests apply to derived
17427 -- types in generics: in a generic body we have to assume the
17428 -- worst, and therefore defaults are not allowed if the parent is
17429 -- a generic formal private type (see ACATS B370001).
17431 if Is_Access_Type (Discr_Type) and then Default_Present then
17432 if Ekind (Discr_Type) /= E_Anonymous_Access_Type
17433 or else Is_Limited_Record (Current_Scope)
17434 or else Is_Concurrent_Type (Current_Scope)
17435 or else Is_Concurrent_Record_Type (Current_Scope)
17436 or else Ekind (Current_Scope) = E_Limited_Private_Type
17438 if not Is_Derived_Type (Current_Scope)
17439 or else not Is_Generic_Type (Etype (Current_Scope))
17440 or else not In_Package_Body (Scope (Etype (Current_Scope)))
17441 or else Limited_Present
17442 (Type_Definition (Parent (Current_Scope)))
17447 Error_Msg_N ("access discriminants of nonlimited types",
17448 Expression (Discr));
17449 Error_Msg_N ("\cannot have defaults", Expression (Discr));
17452 elsif Present (Expression (Discr)) then
17454 ("(Ada 2005) access discriminants of nonlimited types",
17455 Expression (Discr));
17456 Error_Msg_N ("\cannot have defaults", Expression (Discr));
17464 -- An element list consisting of the default expressions of the
17465 -- discriminants is constructed in the above loop and used to set
17466 -- the Discriminant_Constraint attribute for the type. If an object
17467 -- is declared of this (record or task) type without any explicit
17468 -- discriminant constraint given, this element list will form the
17469 -- actual parameters for the corresponding initialization procedure
17472 Set_Discriminant_Constraint (Current_Scope, Elist);
17473 Set_Stored_Constraint (Current_Scope, No_Elist);
17475 -- Default expressions must be provided either for all or for none
17476 -- of the discriminants of a discriminant part. (RM 3.7.1)
17478 if Default_Present and then Default_Not_Present then
17480 ("incomplete specification of defaults for discriminants", N);
17483 -- The use of the name of a discriminant is not allowed in default
17484 -- expressions of a discriminant part if the specification of the
17485 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
17487 -- To detect this, the discriminant names are entered initially with an
17488 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
17489 -- attempt to use a void entity (for example in an expression that is
17490 -- type-checked) produces the error message: premature usage. Now after
17491 -- completing the semantic analysis of the discriminant part, we can set
17492 -- the Ekind of all the discriminants appropriately.
17494 Discr := First (Discriminant_Specifications (N));
17495 Discr_Number := Uint_1;
17496 while Present (Discr) loop
17497 Id := Defining_Identifier (Discr);
17498 Set_Ekind (Id, E_Discriminant);
17499 Init_Component_Location (Id);
17501 Set_Discriminant_Number (Id, Discr_Number);
17503 -- Make sure this is always set, even in illegal programs
17505 Set_Corresponding_Discriminant (Id, Empty);
17507 -- Initialize the Original_Record_Component to the entity itself.
17508 -- Inherit_Components will propagate the right value to
17509 -- discriminants in derived record types.
17511 Set_Original_Record_Component (Id, Id);
17513 -- Create the discriminal for the discriminant
17515 Build_Discriminal (Id);
17518 Discr_Number := Discr_Number + 1;
17521 Set_Has_Discriminants (Current_Scope);
17522 end Process_Discriminants;
17524 -----------------------
17525 -- Process_Full_View --
17526 -----------------------
17528 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
17529 Priv_Parent : Entity_Id;
17530 Full_Parent : Entity_Id;
17531 Full_Indic : Node_Id;
17533 procedure Collect_Implemented_Interfaces
17535 Ifaces : Elist_Id);
17536 -- Ada 2005: Gather all the interfaces that Typ directly or
17537 -- inherently implements. Duplicate entries are not added to
17538 -- the list Ifaces.
17540 ------------------------------------
17541 -- Collect_Implemented_Interfaces --
17542 ------------------------------------
17544 procedure Collect_Implemented_Interfaces
17549 Iface_Elmt : Elmt_Id;
17552 -- Abstract interfaces are only associated with tagged record types
17554 if not Is_Tagged_Type (Typ)
17555 or else not Is_Record_Type (Typ)
17560 -- Recursively climb to the ancestors
17562 if Etype (Typ) /= Typ
17564 -- Protect the frontend against wrong cyclic declarations like:
17566 -- type B is new A with private;
17567 -- type C is new A with private;
17569 -- type B is new C with null record;
17570 -- type C is new B with null record;
17572 and then Etype (Typ) /= Priv_T
17573 and then Etype (Typ) /= Full_T
17575 -- Keep separate the management of private type declarations
17577 if Ekind (Typ) = E_Record_Type_With_Private then
17579 -- Handle the following erroneous case:
17580 -- type Private_Type is tagged private;
17582 -- type Private_Type is new Type_Implementing_Iface;
17584 if Present (Full_View (Typ))
17585 and then Etype (Typ) /= Full_View (Typ)
17587 if Is_Interface (Etype (Typ)) then
17588 Append_Unique_Elmt (Etype (Typ), Ifaces);
17591 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
17594 -- Non-private types
17597 if Is_Interface (Etype (Typ)) then
17598 Append_Unique_Elmt (Etype (Typ), Ifaces);
17601 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
17605 -- Handle entities in the list of abstract interfaces
17607 if Present (Interfaces (Typ)) then
17608 Iface_Elmt := First_Elmt (Interfaces (Typ));
17609 while Present (Iface_Elmt) loop
17610 Iface := Node (Iface_Elmt);
17612 pragma Assert (Is_Interface (Iface));
17614 if not Contain_Interface (Iface, Ifaces) then
17615 Append_Elmt (Iface, Ifaces);
17616 Collect_Implemented_Interfaces (Iface, Ifaces);
17619 Next_Elmt (Iface_Elmt);
17622 end Collect_Implemented_Interfaces;
17624 -- Start of processing for Process_Full_View
17627 -- First some sanity checks that must be done after semantic
17628 -- decoration of the full view and thus cannot be placed with other
17629 -- similar checks in Find_Type_Name
17631 if not Is_Limited_Type (Priv_T)
17632 and then (Is_Limited_Type (Full_T)
17633 or else Is_Limited_Composite (Full_T))
17635 if In_Instance then
17639 ("completion of nonlimited type cannot be limited", Full_T);
17640 Explain_Limited_Type (Full_T, Full_T);
17643 elsif Is_Abstract_Type (Full_T)
17644 and then not Is_Abstract_Type (Priv_T)
17647 ("completion of nonabstract type cannot be abstract", Full_T);
17649 elsif Is_Tagged_Type (Priv_T)
17650 and then Is_Limited_Type (Priv_T)
17651 and then not Is_Limited_Type (Full_T)
17653 -- If pragma CPP_Class was applied to the private declaration
17654 -- propagate the limitedness to the full-view
17656 if Is_CPP_Class (Priv_T) then
17657 Set_Is_Limited_Record (Full_T);
17659 -- GNAT allow its own definition of Limited_Controlled to disobey
17660 -- this rule in order in ease the implementation. This test is safe
17661 -- because Root_Controlled is defined in a child of System that
17662 -- normal programs are not supposed to use.
17664 elsif Is_RTE (Etype (Full_T), RE_Root_Controlled) then
17665 Set_Is_Limited_Composite (Full_T);
17668 ("completion of limited tagged type must be limited", Full_T);
17671 elsif Is_Generic_Type (Priv_T) then
17672 Error_Msg_N ("generic type cannot have a completion", Full_T);
17675 -- Check that ancestor interfaces of private and full views are
17676 -- consistent. We omit this check for synchronized types because
17677 -- they are performed on the corresponding record type when frozen.
17679 if Ada_Version >= Ada_2005
17680 and then Is_Tagged_Type (Priv_T)
17681 and then Is_Tagged_Type (Full_T)
17682 and then not Is_Concurrent_Type (Full_T)
17686 Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
17687 Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
17690 Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
17691 Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
17693 -- Ada 2005 (AI-251): The partial view shall be a descendant of
17694 -- an interface type if and only if the full type is descendant
17695 -- of the interface type (AARM 7.3 (7.3/2)).
17697 Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
17699 if Present (Iface) then
17701 ("interface & not implemented by full type " &
17702 "(RM-2005 7.3 (7.3/2))", Priv_T, Iface);
17705 Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
17707 if Present (Iface) then
17709 ("interface & not implemented by partial view " &
17710 "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
17715 if Is_Tagged_Type (Priv_T)
17716 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
17717 and then Is_Derived_Type (Full_T)
17719 Priv_Parent := Etype (Priv_T);
17721 -- The full view of a private extension may have been transformed
17722 -- into an unconstrained derived type declaration and a subtype
17723 -- declaration (see build_derived_record_type for details).
17725 if Nkind (N) = N_Subtype_Declaration then
17726 Full_Indic := Subtype_Indication (N);
17727 Full_Parent := Etype (Base_Type (Full_T));
17729 Full_Indic := Subtype_Indication (Type_Definition (N));
17730 Full_Parent := Etype (Full_T);
17733 -- Check that the parent type of the full type is a descendant of
17734 -- the ancestor subtype given in the private extension. If either
17735 -- entity has an Etype equal to Any_Type then we had some previous
17736 -- error situation [7.3(8)].
17738 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
17741 -- Ada 2005 (AI-251): Interfaces in the full-typ can be given in
17742 -- any order. Therefore we don't have to check that its parent must
17743 -- be a descendant of the parent of the private type declaration.
17745 elsif Is_Interface (Priv_Parent)
17746 and then Is_Interface (Full_Parent)
17750 -- Ada 2005 (AI-251): If the parent of the private type declaration
17751 -- is an interface there is no need to check that it is an ancestor
17752 -- of the associated full type declaration. The required tests for
17753 -- this case are performed by Build_Derived_Record_Type.
17755 elsif not Is_Interface (Base_Type (Priv_Parent))
17756 and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
17759 ("parent of full type must descend from parent"
17760 & " of private extension", Full_Indic);
17762 -- First check a formal restriction, and then proceed with checking
17763 -- Ada rules. Since the formal restriction is not a serious error, we
17764 -- don't prevent further error detection for this check, hence the
17769 -- In formal mode, when completing a private extension the type
17770 -- named in the private part must be exactly the same as that
17771 -- named in the visible part.
17773 if Priv_Parent /= Full_Parent then
17774 Error_Msg_Name_1 := Chars (Priv_Parent);
17775 Check_SPARK_Restriction ("% expected", Full_Indic);
17778 -- Check the rules of 7.3(10): if the private extension inherits
17779 -- known discriminants, then the full type must also inherit those
17780 -- discriminants from the same (ancestor) type, and the parent
17781 -- subtype of the full type must be constrained if and only if
17782 -- the ancestor subtype of the private extension is constrained.
17784 if No (Discriminant_Specifications (Parent (Priv_T)))
17785 and then not Has_Unknown_Discriminants (Priv_T)
17786 and then Has_Discriminants (Base_Type (Priv_Parent))
17789 Priv_Indic : constant Node_Id :=
17790 Subtype_Indication (Parent (Priv_T));
17792 Priv_Constr : constant Boolean :=
17793 Is_Constrained (Priv_Parent)
17795 Nkind (Priv_Indic) = N_Subtype_Indication
17797 Is_Constrained (Entity (Priv_Indic));
17799 Full_Constr : constant Boolean :=
17800 Is_Constrained (Full_Parent)
17802 Nkind (Full_Indic) = N_Subtype_Indication
17804 Is_Constrained (Entity (Full_Indic));
17806 Priv_Discr : Entity_Id;
17807 Full_Discr : Entity_Id;
17810 Priv_Discr := First_Discriminant (Priv_Parent);
17811 Full_Discr := First_Discriminant (Full_Parent);
17812 while Present (Priv_Discr) and then Present (Full_Discr) loop
17813 if Original_Record_Component (Priv_Discr) =
17814 Original_Record_Component (Full_Discr)
17816 Corresponding_Discriminant (Priv_Discr) =
17817 Corresponding_Discriminant (Full_Discr)
17824 Next_Discriminant (Priv_Discr);
17825 Next_Discriminant (Full_Discr);
17828 if Present (Priv_Discr) or else Present (Full_Discr) then
17830 ("full view must inherit discriminants of the parent"
17831 & " type used in the private extension", Full_Indic);
17833 elsif Priv_Constr and then not Full_Constr then
17835 ("parent subtype of full type must be constrained",
17838 elsif Full_Constr and then not Priv_Constr then
17840 ("parent subtype of full type must be unconstrained",
17845 -- Check the rules of 7.3(12): if a partial view has neither
17846 -- known or unknown discriminants, then the full type
17847 -- declaration shall define a definite subtype.
17849 elsif not Has_Unknown_Discriminants (Priv_T)
17850 and then not Has_Discriminants (Priv_T)
17851 and then not Is_Constrained (Full_T)
17854 ("full view must define a constrained type if partial view"
17855 & " has no discriminants", Full_T);
17858 -- ??????? Do we implement the following properly ?????
17859 -- If the ancestor subtype of a private extension has constrained
17860 -- discriminants, then the parent subtype of the full view shall
17861 -- impose a statically matching constraint on those discriminants
17866 -- For untagged types, verify that a type without discriminants
17867 -- is not completed with an unconstrained type.
17869 if not Is_Indefinite_Subtype (Priv_T)
17870 and then Is_Indefinite_Subtype (Full_T)
17872 Error_Msg_N ("full view of type must be definite subtype", Full_T);
17876 -- AI-419: verify that the use of "limited" is consistent
17879 Orig_Decl : constant Node_Id := Original_Node (N);
17882 if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
17883 and then not Limited_Present (Parent (Priv_T))
17884 and then not Synchronized_Present (Parent (Priv_T))
17885 and then Nkind (Orig_Decl) = N_Full_Type_Declaration
17887 (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition
17888 and then Limited_Present (Type_Definition (Orig_Decl))
17891 ("full view of non-limited extension cannot be limited", N);
17895 -- Ada 2005 (AI-443): A synchronized private extension must be
17896 -- completed by a task or protected type.
17898 if Ada_Version >= Ada_2005
17899 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
17900 and then Synchronized_Present (Parent (Priv_T))
17901 and then not Is_Concurrent_Type (Full_T)
17903 Error_Msg_N ("full view of synchronized extension must " &
17904 "be synchronized type", N);
17907 -- Ada 2005 AI-363: if the full view has discriminants with
17908 -- defaults, it is illegal to declare constrained access subtypes
17909 -- whose designated type is the current type. This allows objects
17910 -- of the type that are declared in the heap to be unconstrained.
17912 if not Has_Unknown_Discriminants (Priv_T)
17913 and then not Has_Discriminants (Priv_T)
17914 and then Has_Discriminants (Full_T)
17916 Present (Discriminant_Default_Value (First_Discriminant (Full_T)))
17918 Set_Has_Constrained_Partial_View (Full_T);
17919 Set_Has_Constrained_Partial_View (Priv_T);
17922 -- Create a full declaration for all its subtypes recorded in
17923 -- Private_Dependents and swap them similarly to the base type. These
17924 -- are subtypes that have been define before the full declaration of
17925 -- the private type. We also swap the entry in Private_Dependents list
17926 -- so we can properly restore the private view on exit from the scope.
17929 Priv_Elmt : Elmt_Id;
17934 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
17935 while Present (Priv_Elmt) loop
17936 Priv := Node (Priv_Elmt);
17938 if Ekind_In (Priv, E_Private_Subtype,
17939 E_Limited_Private_Subtype,
17940 E_Record_Subtype_With_Private)
17942 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
17943 Set_Is_Itype (Full);
17944 Set_Parent (Full, Parent (Priv));
17945 Set_Associated_Node_For_Itype (Full, N);
17947 -- Now we need to complete the private subtype, but since the
17948 -- base type has already been swapped, we must also swap the
17949 -- subtypes (and thus, reverse the arguments in the call to
17950 -- Complete_Private_Subtype).
17952 Copy_And_Swap (Priv, Full);
17953 Complete_Private_Subtype (Full, Priv, Full_T, N);
17954 Replace_Elmt (Priv_Elmt, Full);
17957 Next_Elmt (Priv_Elmt);
17961 -- If the private view was tagged, copy the new primitive operations
17962 -- from the private view to the full view.
17964 if Is_Tagged_Type (Full_T) then
17966 Disp_Typ : Entity_Id;
17967 Full_List : Elist_Id;
17969 Prim_Elmt : Elmt_Id;
17970 Priv_List : Elist_Id;
17974 L : Elist_Id) return Boolean;
17975 -- Determine whether list L contains element E
17983 L : Elist_Id) return Boolean
17985 List_Elmt : Elmt_Id;
17988 List_Elmt := First_Elmt (L);
17989 while Present (List_Elmt) loop
17990 if Node (List_Elmt) = E then
17994 Next_Elmt (List_Elmt);
18000 -- Start of processing
18003 if Is_Tagged_Type (Priv_T) then
18004 Priv_List := Primitive_Operations (Priv_T);
18005 Prim_Elmt := First_Elmt (Priv_List);
18007 -- In the case of a concurrent type completing a private tagged
18008 -- type, primitives may have been declared in between the two
18009 -- views. These subprograms need to be wrapped the same way
18010 -- entries and protected procedures are handled because they
18011 -- cannot be directly shared by the two views.
18013 if Is_Concurrent_Type (Full_T) then
18015 Conc_Typ : constant Entity_Id :=
18016 Corresponding_Record_Type (Full_T);
18017 Curr_Nod : Node_Id := Parent (Conc_Typ);
18018 Wrap_Spec : Node_Id;
18021 while Present (Prim_Elmt) loop
18022 Prim := Node (Prim_Elmt);
18024 if Comes_From_Source (Prim)
18025 and then not Is_Abstract_Subprogram (Prim)
18028 Make_Subprogram_Declaration (Sloc (Prim),
18032 Obj_Typ => Conc_Typ,
18034 Parameter_Specifications (
18037 Insert_After (Curr_Nod, Wrap_Spec);
18038 Curr_Nod := Wrap_Spec;
18040 Analyze (Wrap_Spec);
18043 Next_Elmt (Prim_Elmt);
18049 -- For non-concurrent types, transfer explicit primitives, but
18050 -- omit those inherited from the parent of the private view
18051 -- since they will be re-inherited later on.
18054 Full_List := Primitive_Operations (Full_T);
18056 while Present (Prim_Elmt) loop
18057 Prim := Node (Prim_Elmt);
18059 if Comes_From_Source (Prim)
18060 and then not Contains (Prim, Full_List)
18062 Append_Elmt (Prim, Full_List);
18065 Next_Elmt (Prim_Elmt);
18069 -- Untagged private view
18072 Full_List := Primitive_Operations (Full_T);
18074 -- In this case the partial view is untagged, so here we locate
18075 -- all of the earlier primitives that need to be treated as
18076 -- dispatching (those that appear between the two views). Note
18077 -- that these additional operations must all be new operations
18078 -- (any earlier operations that override inherited operations
18079 -- of the full view will already have been inserted in the
18080 -- primitives list, marked by Check_Operation_From_Private_View
18081 -- as dispatching. Note that implicit "/=" operators are
18082 -- excluded from being added to the primitives list since they
18083 -- shouldn't be treated as dispatching (tagged "/=" is handled
18086 Prim := Next_Entity (Full_T);
18087 while Present (Prim) and then Prim /= Priv_T loop
18088 if Ekind_In (Prim, E_Procedure, E_Function) then
18089 Disp_Typ := Find_Dispatching_Type (Prim);
18091 if Disp_Typ = Full_T
18092 and then (Chars (Prim) /= Name_Op_Ne
18093 or else Comes_From_Source (Prim))
18095 Check_Controlling_Formals (Full_T, Prim);
18097 if not Is_Dispatching_Operation (Prim) then
18098 Append_Elmt (Prim, Full_List);
18099 Set_Is_Dispatching_Operation (Prim, True);
18100 Set_DT_Position (Prim, No_Uint);
18103 elsif Is_Dispatching_Operation (Prim)
18104 and then Disp_Typ /= Full_T
18107 -- Verify that it is not otherwise controlled by a
18108 -- formal or a return value of type T.
18110 Check_Controlling_Formals (Disp_Typ, Prim);
18114 Next_Entity (Prim);
18118 -- For the tagged case, the two views can share the same primitive
18119 -- operations list and the same class-wide type. Update attributes
18120 -- of the class-wide type which depend on the full declaration.
18122 if Is_Tagged_Type (Priv_T) then
18123 Set_Direct_Primitive_Operations (Priv_T, Full_List);
18124 Set_Class_Wide_Type
18125 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
18127 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
18132 -- Ada 2005 AI 161: Check preelaboratable initialization consistency
18134 if Known_To_Have_Preelab_Init (Priv_T) then
18136 -- Case where there is a pragma Preelaborable_Initialization. We
18137 -- always allow this in predefined units, which is a bit of a kludge,
18138 -- but it means we don't have to struggle to meet the requirements in
18139 -- the RM for having Preelaborable Initialization. Otherwise we
18140 -- require that the type meets the RM rules. But we can't check that
18141 -- yet, because of the rule about overriding Initialize, so we simply
18142 -- set a flag that will be checked at freeze time.
18144 if not In_Predefined_Unit (Full_T) then
18145 Set_Must_Have_Preelab_Init (Full_T);
18149 -- If pragma CPP_Class was applied to the private type declaration,
18150 -- propagate it now to the full type declaration.
18152 if Is_CPP_Class (Priv_T) then
18153 Set_Is_CPP_Class (Full_T);
18154 Set_Convention (Full_T, Convention_CPP);
18156 -- Check that components of imported CPP types do not have default
18159 Check_CPP_Type_Has_No_Defaults (Full_T);
18162 -- If the private view has user specified stream attributes, then so has
18165 -- Why the test, how could these flags be already set in Full_T ???
18167 if Has_Specified_Stream_Read (Priv_T) then
18168 Set_Has_Specified_Stream_Read (Full_T);
18171 if Has_Specified_Stream_Write (Priv_T) then
18172 Set_Has_Specified_Stream_Write (Full_T);
18175 if Has_Specified_Stream_Input (Priv_T) then
18176 Set_Has_Specified_Stream_Input (Full_T);
18179 if Has_Specified_Stream_Output (Priv_T) then
18180 Set_Has_Specified_Stream_Output (Full_T);
18183 -- Propagate invariants to full type
18185 if Has_Invariants (Priv_T) then
18186 Set_Has_Invariants (Full_T);
18187 Set_Invariant_Procedure (Full_T, Invariant_Procedure (Priv_T));
18190 if Has_Inheritable_Invariants (Priv_T) then
18191 Set_Has_Inheritable_Invariants (Full_T);
18194 -- Propagate predicates to full type
18196 if Has_Predicates (Priv_T) then
18197 Set_Predicate_Function (Priv_T, Predicate_Function (Full_T));
18198 Set_Has_Predicates (Full_T);
18200 end Process_Full_View;
18202 -----------------------------------
18203 -- Process_Incomplete_Dependents --
18204 -----------------------------------
18206 procedure Process_Incomplete_Dependents
18208 Full_T : Entity_Id;
18211 Inc_Elmt : Elmt_Id;
18212 Priv_Dep : Entity_Id;
18213 New_Subt : Entity_Id;
18215 Disc_Constraint : Elist_Id;
18218 if No (Private_Dependents (Inc_T)) then
18222 -- Itypes that may be generated by the completion of an incomplete
18223 -- subtype are not used by the back-end and not attached to the tree.
18224 -- They are created only for constraint-checking purposes.
18226 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
18227 while Present (Inc_Elmt) loop
18228 Priv_Dep := Node (Inc_Elmt);
18230 if Ekind (Priv_Dep) = E_Subprogram_Type then
18232 -- An Access_To_Subprogram type may have a return type or a
18233 -- parameter type that is incomplete. Replace with the full view.
18235 if Etype (Priv_Dep) = Inc_T then
18236 Set_Etype (Priv_Dep, Full_T);
18240 Formal : Entity_Id;
18243 Formal := First_Formal (Priv_Dep);
18244 while Present (Formal) loop
18245 if Etype (Formal) = Inc_T then
18246 Set_Etype (Formal, Full_T);
18249 Next_Formal (Formal);
18253 elsif Is_Overloadable (Priv_Dep) then
18255 -- If a subprogram in the incomplete dependents list is primitive
18256 -- for a tagged full type then mark it as a dispatching operation,
18257 -- check whether it overrides an inherited subprogram, and check
18258 -- restrictions on its controlling formals. Note that a protected
18259 -- operation is never dispatching: only its wrapper operation
18260 -- (which has convention Ada) is.
18262 if Is_Tagged_Type (Full_T)
18263 and then Is_Primitive (Priv_Dep)
18264 and then Convention (Priv_Dep) /= Convention_Protected
18266 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
18267 Set_Is_Dispatching_Operation (Priv_Dep);
18268 Check_Controlling_Formals (Full_T, Priv_Dep);
18271 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
18273 -- Can happen during processing of a body before the completion
18274 -- of a TA type. Ignore, because spec is also on dependent list.
18278 -- Ada 2005 (AI-412): Transform a regular incomplete subtype into a
18279 -- corresponding subtype of the full view.
18281 elsif Ekind (Priv_Dep) = E_Incomplete_Subtype then
18282 Set_Subtype_Indication
18283 (Parent (Priv_Dep), New_Reference_To (Full_T, Sloc (Priv_Dep)));
18284 Set_Etype (Priv_Dep, Full_T);
18285 Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T)));
18286 Set_Analyzed (Parent (Priv_Dep), False);
18288 -- Reanalyze the declaration, suppressing the call to
18289 -- Enter_Name to avoid duplicate names.
18291 Analyze_Subtype_Declaration
18292 (N => Parent (Priv_Dep),
18295 -- Dependent is a subtype
18298 -- We build a new subtype indication using the full view of the
18299 -- incomplete parent. The discriminant constraints have been
18300 -- elaborated already at the point of the subtype declaration.
18302 New_Subt := Create_Itype (E_Void, N);
18304 if Has_Discriminants (Full_T) then
18305 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
18307 Disc_Constraint := No_Elist;
18310 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
18311 Set_Full_View (Priv_Dep, New_Subt);
18314 Next_Elmt (Inc_Elmt);
18316 end Process_Incomplete_Dependents;
18318 --------------------------------
18319 -- Process_Range_Expr_In_Decl --
18320 --------------------------------
18322 procedure Process_Range_Expr_In_Decl
18325 Check_List : List_Id := Empty_List;
18326 R_Check_Off : Boolean := False;
18327 In_Iter_Schm : Boolean := False)
18330 R_Checks : Check_Result;
18331 Insert_Node : Node_Id;
18332 Def_Id : Entity_Id;
18335 Analyze_And_Resolve (R, Base_Type (T));
18337 if Nkind (R) = N_Range then
18339 -- In SPARK, all ranges should be static, with the exception of the
18340 -- discrete type definition of a loop parameter specification.
18342 if not In_Iter_Schm
18343 and then not Is_Static_Range (R)
18345 Check_SPARK_Restriction ("range should be static", R);
18348 Lo := Low_Bound (R);
18349 Hi := High_Bound (R);
18351 -- We need to ensure validity of the bounds here, because if we
18352 -- go ahead and do the expansion, then the expanded code will get
18353 -- analyzed with range checks suppressed and we miss the check.
18355 Validity_Check_Range (R);
18357 -- If there were errors in the declaration, try and patch up some
18358 -- common mistakes in the bounds. The cases handled are literals
18359 -- which are Integer where the expected type is Real and vice versa.
18360 -- These corrections allow the compilation process to proceed further
18361 -- along since some basic assumptions of the format of the bounds
18364 if Etype (R) = Any_Type then
18366 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
18368 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
18370 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
18372 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
18374 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
18376 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
18378 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
18380 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
18387 -- If the bounds of the range have been mistakenly given as string
18388 -- literals (perhaps in place of character literals), then an error
18389 -- has already been reported, but we rewrite the string literal as a
18390 -- bound of the range's type to avoid blowups in later processing
18391 -- that looks at static values.
18393 if Nkind (Lo) = N_String_Literal then
18395 Make_Attribute_Reference (Sloc (Lo),
18396 Attribute_Name => Name_First,
18397 Prefix => New_Reference_To (T, Sloc (Lo))));
18398 Analyze_And_Resolve (Lo);
18401 if Nkind (Hi) = N_String_Literal then
18403 Make_Attribute_Reference (Sloc (Hi),
18404 Attribute_Name => Name_First,
18405 Prefix => New_Reference_To (T, Sloc (Hi))));
18406 Analyze_And_Resolve (Hi);
18409 -- If bounds aren't scalar at this point then exit, avoiding
18410 -- problems with further processing of the range in this procedure.
18412 if not Is_Scalar_Type (Etype (Lo)) then
18416 -- Resolve (actually Sem_Eval) has checked that the bounds are in
18417 -- then range of the base type. Here we check whether the bounds
18418 -- are in the range of the subtype itself. Note that if the bounds
18419 -- represent the null range the Constraint_Error exception should
18422 -- ??? The following code should be cleaned up as follows
18424 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
18425 -- is done in the call to Range_Check (R, T); below
18427 -- 2. The use of R_Check_Off should be investigated and possibly
18428 -- removed, this would clean up things a bit.
18430 if Is_Null_Range (Lo, Hi) then
18434 -- Capture values of bounds and generate temporaries for them
18435 -- if needed, before applying checks, since checks may cause
18436 -- duplication of the expression without forcing evaluation.
18438 -- The forced evaluation removes side effects from expressions,
18439 -- which should occur also in Alfa mode. Otherwise, we end up with
18440 -- unexpected insertions of actions at places where this is not
18441 -- supposed to occur, e.g. on default parameters of a call.
18443 if Expander_Active then
18444 Force_Evaluation (Lo);
18445 Force_Evaluation (Hi);
18448 -- We use a flag here instead of suppressing checks on the
18449 -- type because the type we check against isn't necessarily
18450 -- the place where we put the check.
18452 if not R_Check_Off then
18453 R_Checks := Get_Range_Checks (R, T);
18455 -- Look up tree to find an appropriate insertion point. We
18456 -- can't just use insert_actions because later processing
18457 -- depends on the insertion node. Prior to Ada 2012 the
18458 -- insertion point could only be a declaration or a loop, but
18459 -- quantified expressions can appear within any context in an
18460 -- expression, and the insertion point can be any statement,
18461 -- pragma, or declaration.
18463 Insert_Node := Parent (R);
18464 while Present (Insert_Node) loop
18466 Nkind (Insert_Node) in N_Declaration
18469 (Insert_Node, N_Component_Declaration,
18470 N_Loop_Parameter_Specification,
18471 N_Function_Specification,
18472 N_Procedure_Specification);
18474 exit when Nkind (Insert_Node) in N_Later_Decl_Item
18475 or else Nkind (Insert_Node) in
18476 N_Statement_Other_Than_Procedure_Call
18477 or else Nkind_In (Insert_Node, N_Procedure_Call_Statement,
18480 Insert_Node := Parent (Insert_Node);
18483 -- Why would Type_Decl not be present??? Without this test,
18484 -- short regression tests fail.
18486 if Present (Insert_Node) then
18488 -- Case of loop statement. Verify that the range is part
18489 -- of the subtype indication of the iteration scheme.
18491 if Nkind (Insert_Node) = N_Loop_Statement then
18496 Indic := Parent (R);
18497 while Present (Indic)
18498 and then Nkind (Indic) /= N_Subtype_Indication
18500 Indic := Parent (Indic);
18503 if Present (Indic) then
18504 Def_Id := Etype (Subtype_Mark (Indic));
18506 Insert_Range_Checks
18510 Sloc (Insert_Node),
18512 Do_Before => True);
18516 -- Insertion before a declaration. If the declaration
18517 -- includes discriminants, the list of applicable checks
18518 -- is given by the caller.
18520 elsif Nkind (Insert_Node) in N_Declaration then
18521 Def_Id := Defining_Identifier (Insert_Node);
18523 if (Ekind (Def_Id) = E_Record_Type
18524 and then Depends_On_Discriminant (R))
18526 (Ekind (Def_Id) = E_Protected_Type
18527 and then Has_Discriminants (Def_Id))
18529 Append_Range_Checks
18531 Check_List, Def_Id, Sloc (Insert_Node), R);
18534 Insert_Range_Checks
18536 Insert_Node, Def_Id, Sloc (Insert_Node), R);
18540 -- Insertion before a statement. Range appears in the
18541 -- context of a quantified expression. Insertion will
18542 -- take place when expression is expanded.
18551 -- Case of other than an explicit N_Range node
18553 -- The forced evaluation removes side effects from expressions, which
18554 -- should occur also in Alfa mode. Otherwise, we end up with unexpected
18555 -- insertions of actions at places where this is not supposed to occur,
18556 -- e.g. on default parameters of a call.
18558 elsif Expander_Active then
18559 Get_Index_Bounds (R, Lo, Hi);
18560 Force_Evaluation (Lo);
18561 Force_Evaluation (Hi);
18563 end Process_Range_Expr_In_Decl;
18565 --------------------------------------
18566 -- Process_Real_Range_Specification --
18567 --------------------------------------
18569 procedure Process_Real_Range_Specification (Def : Node_Id) is
18570 Spec : constant Node_Id := Real_Range_Specification (Def);
18573 Err : Boolean := False;
18575 procedure Analyze_Bound (N : Node_Id);
18576 -- Analyze and check one bound
18578 -------------------
18579 -- Analyze_Bound --
18580 -------------------
18582 procedure Analyze_Bound (N : Node_Id) is
18584 Analyze_And_Resolve (N, Any_Real);
18586 if not Is_OK_Static_Expression (N) then
18587 Flag_Non_Static_Expr
18588 ("bound in real type definition is not static!", N);
18593 -- Start of processing for Process_Real_Range_Specification
18596 if Present (Spec) then
18597 Lo := Low_Bound (Spec);
18598 Hi := High_Bound (Spec);
18599 Analyze_Bound (Lo);
18600 Analyze_Bound (Hi);
18602 -- If error, clear away junk range specification
18605 Set_Real_Range_Specification (Def, Empty);
18608 end Process_Real_Range_Specification;
18610 ---------------------
18611 -- Process_Subtype --
18612 ---------------------
18614 function Process_Subtype
18616 Related_Nod : Node_Id;
18617 Related_Id : Entity_Id := Empty;
18618 Suffix : Character := ' ') return Entity_Id
18621 Def_Id : Entity_Id;
18622 Error_Node : Node_Id;
18623 Full_View_Id : Entity_Id;
18624 Subtype_Mark_Id : Entity_Id;
18626 May_Have_Null_Exclusion : Boolean;
18628 procedure Check_Incomplete (T : Entity_Id);
18629 -- Called to verify that an incomplete type is not used prematurely
18631 ----------------------
18632 -- Check_Incomplete --
18633 ----------------------
18635 procedure Check_Incomplete (T : Entity_Id) is
18637 -- Ada 2005 (AI-412): Incomplete subtypes are legal
18639 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type
18641 not (Ada_Version >= Ada_2005
18643 (Nkind (Parent (T)) = N_Subtype_Declaration
18645 (Nkind (Parent (T)) = N_Subtype_Indication
18646 and then Nkind (Parent (Parent (T))) =
18647 N_Subtype_Declaration)))
18649 Error_Msg_N ("invalid use of type before its full declaration", T);
18651 end Check_Incomplete;
18653 -- Start of processing for Process_Subtype
18656 -- Case of no constraints present
18658 if Nkind (S) /= N_Subtype_Indication then
18660 Check_Incomplete (S);
18663 -- Ada 2005 (AI-231): Static check
18665 if Ada_Version >= Ada_2005
18666 and then Present (P)
18667 and then Null_Exclusion_Present (P)
18668 and then Nkind (P) /= N_Access_To_Object_Definition
18669 and then not Is_Access_Type (Entity (S))
18671 Error_Msg_N ("`NOT NULL` only allowed for an access type", S);
18674 -- The following is ugly, can't we have a range or even a flag???
18676 May_Have_Null_Exclusion :=
18677 Nkind_In (P, N_Access_Definition,
18678 N_Access_Function_Definition,
18679 N_Access_Procedure_Definition,
18680 N_Access_To_Object_Definition,
18682 N_Component_Definition)
18684 Nkind_In (P, N_Derived_Type_Definition,
18685 N_Discriminant_Specification,
18686 N_Formal_Object_Declaration,
18687 N_Object_Declaration,
18688 N_Object_Renaming_Declaration,
18689 N_Parameter_Specification,
18690 N_Subtype_Declaration);
18692 -- Create an Itype that is a duplicate of Entity (S) but with the
18693 -- null-exclusion attribute.
18695 if May_Have_Null_Exclusion
18696 and then Is_Access_Type (Entity (S))
18697 and then Null_Exclusion_Present (P)
18699 -- No need to check the case of an access to object definition.
18700 -- It is correct to define double not-null pointers.
18703 -- type Not_Null_Int_Ptr is not null access Integer;
18704 -- type Acc is not null access Not_Null_Int_Ptr;
18706 and then Nkind (P) /= N_Access_To_Object_Definition
18708 if Can_Never_Be_Null (Entity (S)) then
18709 case Nkind (Related_Nod) is
18710 when N_Full_Type_Declaration =>
18711 if Nkind (Type_Definition (Related_Nod))
18712 in N_Array_Type_Definition
18716 (Component_Definition
18717 (Type_Definition (Related_Nod)));
18720 Subtype_Indication (Type_Definition (Related_Nod));
18723 when N_Subtype_Declaration =>
18724 Error_Node := Subtype_Indication (Related_Nod);
18726 when N_Object_Declaration =>
18727 Error_Node := Object_Definition (Related_Nod);
18729 when N_Component_Declaration =>
18731 Subtype_Indication (Component_Definition (Related_Nod));
18733 when N_Allocator =>
18734 Error_Node := Expression (Related_Nod);
18737 pragma Assert (False);
18738 Error_Node := Related_Nod;
18742 ("`NOT NULL` not allowed (& already excludes null)",
18748 Create_Null_Excluding_Itype
18750 Related_Nod => P));
18751 Set_Entity (S, Etype (S));
18756 -- Case of constraint present, so that we have an N_Subtype_Indication
18757 -- node (this node is created only if constraints are present).
18760 Find_Type (Subtype_Mark (S));
18762 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
18764 (Nkind (Parent (S)) = N_Subtype_Declaration
18765 and then Is_Itype (Defining_Identifier (Parent (S))))
18767 Check_Incomplete (Subtype_Mark (S));
18771 Subtype_Mark_Id := Entity (Subtype_Mark (S));
18773 -- Explicit subtype declaration case
18775 if Nkind (P) = N_Subtype_Declaration then
18776 Def_Id := Defining_Identifier (P);
18778 -- Explicit derived type definition case
18780 elsif Nkind (P) = N_Derived_Type_Definition then
18781 Def_Id := Defining_Identifier (Parent (P));
18783 -- Implicit case, the Def_Id must be created as an implicit type.
18784 -- The one exception arises in the case of concurrent types, array
18785 -- and access types, where other subsidiary implicit types may be
18786 -- created and must appear before the main implicit type. In these
18787 -- cases we leave Def_Id set to Empty as a signal that Create_Itype
18788 -- has not yet been called to create Def_Id.
18791 if Is_Array_Type (Subtype_Mark_Id)
18792 or else Is_Concurrent_Type (Subtype_Mark_Id)
18793 or else Is_Access_Type (Subtype_Mark_Id)
18797 -- For the other cases, we create a new unattached Itype,
18798 -- and set the indication to ensure it gets attached later.
18802 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
18806 -- If the kind of constraint is invalid for this kind of type,
18807 -- then give an error, and then pretend no constraint was given.
18809 if not Is_Valid_Constraint_Kind
18810 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
18813 ("incorrect constraint for this kind of type", Constraint (S));
18815 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
18817 -- Set Ekind of orphan itype, to prevent cascaded errors
18819 if Present (Def_Id) then
18820 Set_Ekind (Def_Id, Ekind (Any_Type));
18823 -- Make recursive call, having got rid of the bogus constraint
18825 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
18828 -- Remaining processing depends on type. Select on Base_Type kind to
18829 -- ensure getting to the concrete type kind in the case of a private
18830 -- subtype (needed when only doing semantic analysis).
18832 case Ekind (Base_Type (Subtype_Mark_Id)) is
18833 when Access_Kind =>
18834 Constrain_Access (Def_Id, S, Related_Nod);
18837 and then Is_Itype (Designated_Type (Def_Id))
18838 and then Nkind (Related_Nod) = N_Subtype_Declaration
18839 and then not Is_Incomplete_Type (Designated_Type (Def_Id))
18841 Build_Itype_Reference
18842 (Designated_Type (Def_Id), Related_Nod);
18846 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
18848 when Decimal_Fixed_Point_Kind =>
18849 Constrain_Decimal (Def_Id, S);
18851 when Enumeration_Kind =>
18852 Constrain_Enumeration (Def_Id, S);
18854 when Ordinary_Fixed_Point_Kind =>
18855 Constrain_Ordinary_Fixed (Def_Id, S);
18858 Constrain_Float (Def_Id, S);
18860 when Integer_Kind =>
18861 Constrain_Integer (Def_Id, S);
18863 when E_Record_Type |
18866 E_Incomplete_Type =>
18867 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
18869 if Ekind (Def_Id) = E_Incomplete_Type then
18870 Set_Private_Dependents (Def_Id, New_Elmt_List);
18873 when Private_Kind =>
18874 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
18875 Set_Private_Dependents (Def_Id, New_Elmt_List);
18877 -- In case of an invalid constraint prevent further processing
18878 -- since the type constructed is missing expected fields.
18880 if Etype (Def_Id) = Any_Type then
18884 -- If the full view is that of a task with discriminants,
18885 -- we must constrain both the concurrent type and its
18886 -- corresponding record type. Otherwise we will just propagate
18887 -- the constraint to the full view, if available.
18889 if Present (Full_View (Subtype_Mark_Id))
18890 and then Has_Discriminants (Subtype_Mark_Id)
18891 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
18894 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
18896 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
18897 Constrain_Concurrent (Full_View_Id, S,
18898 Related_Nod, Related_Id, Suffix);
18899 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
18900 Set_Full_View (Def_Id, Full_View_Id);
18902 -- Introduce an explicit reference to the private subtype,
18903 -- to prevent scope anomalies in gigi if first use appears
18904 -- in a nested context, e.g. a later function body.
18905 -- Should this be generated in other contexts than a full
18906 -- type declaration?
18908 if Is_Itype (Def_Id)
18910 Nkind (Parent (P)) = N_Full_Type_Declaration
18912 Build_Itype_Reference (Def_Id, Parent (P));
18916 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
18919 when Concurrent_Kind =>
18920 Constrain_Concurrent (Def_Id, S,
18921 Related_Nod, Related_Id, Suffix);
18924 Error_Msg_N ("invalid subtype mark in subtype indication", S);
18927 -- Size and Convention are always inherited from the base type
18929 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
18930 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
18934 end Process_Subtype;
18936 ---------------------------------------
18937 -- Check_Anonymous_Access_Components --
18938 ---------------------------------------
18940 procedure Check_Anonymous_Access_Components
18941 (Typ_Decl : Node_Id;
18944 Comp_List : Node_Id)
18946 Loc : constant Source_Ptr := Sloc (Typ_Decl);
18947 Anon_Access : Entity_Id;
18950 Comp_Def : Node_Id;
18952 Type_Def : Node_Id;
18954 procedure Build_Incomplete_Type_Declaration;
18955 -- If the record type contains components that include an access to the
18956 -- current record, then create an incomplete type declaration for the
18957 -- record, to be used as the designated type of the anonymous access.
18958 -- This is done only once, and only if there is no previous partial
18959 -- view of the type.
18961 function Designates_T (Subt : Node_Id) return Boolean;
18962 -- Check whether a node designates the enclosing record type, or 'Class
18965 function Mentions_T (Acc_Def : Node_Id) return Boolean;
18966 -- Check whether an access definition includes a reference to
18967 -- the enclosing record type. The reference can be a subtype mark
18968 -- in the access definition itself, a 'Class attribute reference, or
18969 -- recursively a reference appearing in a parameter specification
18970 -- or result definition of an access_to_subprogram definition.
18972 --------------------------------------
18973 -- Build_Incomplete_Type_Declaration --
18974 --------------------------------------
18976 procedure Build_Incomplete_Type_Declaration is
18981 -- Is_Tagged indicates whether the type is tagged. It is tagged if
18982 -- it's "is new ... with record" or else "is tagged record ...".
18984 Is_Tagged : constant Boolean :=
18985 (Nkind (Type_Definition (Typ_Decl)) = N_Derived_Type_Definition
18988 (Record_Extension_Part (Type_Definition (Typ_Decl))))
18990 (Nkind (Type_Definition (Typ_Decl)) = N_Record_Definition
18991 and then Tagged_Present (Type_Definition (Typ_Decl)));
18994 -- If there is a previous partial view, no need to create a new one
18995 -- If the partial view, given by Prev, is incomplete, If Prev is
18996 -- a private declaration, full declaration is flagged accordingly.
18998 if Prev /= Typ then
19000 Make_Class_Wide_Type (Prev);
19001 Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev));
19002 Set_Etype (Class_Wide_Type (Typ), Typ);
19007 elsif Has_Private_Declaration (Typ) then
19009 -- If we refer to T'Class inside T, and T is the completion of a
19010 -- private type, then we need to make sure the class-wide type
19014 Make_Class_Wide_Type (Typ);
19019 -- If there was a previous anonymous access type, the incomplete
19020 -- type declaration will have been created already.
19022 elsif Present (Current_Entity (Typ))
19023 and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type
19024 and then Full_View (Current_Entity (Typ)) = Typ
19027 and then Comes_From_Source (Current_Entity (Typ))
19028 and then not Is_Tagged_Type (Current_Entity (Typ))
19030 Make_Class_Wide_Type (Typ);
19032 ("incomplete view of tagged type should be declared tagged?",
19033 Parent (Current_Entity (Typ)));
19038 Inc_T := Make_Defining_Identifier (Loc, Chars (Typ));
19039 Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
19041 -- Type has already been inserted into the current scope. Remove
19042 -- it, and add incomplete declaration for type, so that subsequent
19043 -- anonymous access types can use it. The entity is unchained from
19044 -- the homonym list and from immediate visibility. After analysis,
19045 -- the entity in the incomplete declaration becomes immediately
19046 -- visible in the record declaration that follows.
19048 H := Current_Entity (Typ);
19051 Set_Name_Entity_Id (Chars (Typ), Homonym (Typ));
19054 and then Homonym (H) /= Typ
19056 H := Homonym (Typ);
19059 Set_Homonym (H, Homonym (Typ));
19062 Insert_Before (Typ_Decl, Decl);
19064 Set_Full_View (Inc_T, Typ);
19068 -- Create a common class-wide type for both views, and set the
19069 -- Etype of the class-wide type to the full view.
19071 Make_Class_Wide_Type (Inc_T);
19072 Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T));
19073 Set_Etype (Class_Wide_Type (Typ), Typ);
19076 end Build_Incomplete_Type_Declaration;
19082 function Designates_T (Subt : Node_Id) return Boolean is
19083 Type_Id : constant Name_Id := Chars (Typ);
19085 function Names_T (Nam : Node_Id) return Boolean;
19086 -- The record type has not been introduced in the current scope
19087 -- yet, so we must examine the name of the type itself, either
19088 -- an identifier T, or an expanded name of the form P.T, where
19089 -- P denotes the current scope.
19095 function Names_T (Nam : Node_Id) return Boolean is
19097 if Nkind (Nam) = N_Identifier then
19098 return Chars (Nam) = Type_Id;
19100 elsif Nkind (Nam) = N_Selected_Component then
19101 if Chars (Selector_Name (Nam)) = Type_Id then
19102 if Nkind (Prefix (Nam)) = N_Identifier then
19103 return Chars (Prefix (Nam)) = Chars (Current_Scope);
19105 elsif Nkind (Prefix (Nam)) = N_Selected_Component then
19106 return Chars (Selector_Name (Prefix (Nam))) =
19107 Chars (Current_Scope);
19121 -- Start of processing for Designates_T
19124 if Nkind (Subt) = N_Identifier then
19125 return Chars (Subt) = Type_Id;
19127 -- Reference can be through an expanded name which has not been
19128 -- analyzed yet, and which designates enclosing scopes.
19130 elsif Nkind (Subt) = N_Selected_Component then
19131 if Names_T (Subt) then
19134 -- Otherwise it must denote an entity that is already visible.
19135 -- The access definition may name a subtype of the enclosing
19136 -- type, if there is a previous incomplete declaration for it.
19139 Find_Selected_Component (Subt);
19141 Is_Entity_Name (Subt)
19142 and then Scope (Entity (Subt)) = Current_Scope
19144 (Chars (Base_Type (Entity (Subt))) = Type_Id
19146 (Is_Class_Wide_Type (Entity (Subt))
19148 Chars (Etype (Base_Type (Entity (Subt)))) =
19152 -- A reference to the current type may appear as the prefix of
19153 -- a 'Class attribute.
19155 elsif Nkind (Subt) = N_Attribute_Reference
19156 and then Attribute_Name (Subt) = Name_Class
19158 return Names_T (Prefix (Subt));
19169 function Mentions_T (Acc_Def : Node_Id) return Boolean is
19170 Param_Spec : Node_Id;
19172 Acc_Subprg : constant Node_Id :=
19173 Access_To_Subprogram_Definition (Acc_Def);
19176 if No (Acc_Subprg) then
19177 return Designates_T (Subtype_Mark (Acc_Def));
19180 -- Component is an access_to_subprogram: examine its formals,
19181 -- and result definition in the case of an access_to_function.
19183 Param_Spec := First (Parameter_Specifications (Acc_Subprg));
19184 while Present (Param_Spec) loop
19185 if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition
19186 and then Mentions_T (Parameter_Type (Param_Spec))
19190 elsif Designates_T (Parameter_Type (Param_Spec)) then
19197 if Nkind (Acc_Subprg) = N_Access_Function_Definition then
19198 if Nkind (Result_Definition (Acc_Subprg)) =
19199 N_Access_Definition
19201 return Mentions_T (Result_Definition (Acc_Subprg));
19203 return Designates_T (Result_Definition (Acc_Subprg));
19210 -- Start of processing for Check_Anonymous_Access_Components
19213 if No (Comp_List) then
19217 Comp := First (Component_Items (Comp_List));
19218 while Present (Comp) loop
19219 if Nkind (Comp) = N_Component_Declaration
19221 (Access_Definition (Component_Definition (Comp)))
19223 Mentions_T (Access_Definition (Component_Definition (Comp)))
19225 Comp_Def := Component_Definition (Comp);
19227 Access_To_Subprogram_Definition
19228 (Access_Definition (Comp_Def));
19230 Build_Incomplete_Type_Declaration;
19231 Anon_Access := Make_Temporary (Loc, 'S');
19233 -- Create a declaration for the anonymous access type: either
19234 -- an access_to_object or an access_to_subprogram.
19236 if Present (Acc_Def) then
19237 if Nkind (Acc_Def) = N_Access_Function_Definition then
19239 Make_Access_Function_Definition (Loc,
19240 Parameter_Specifications =>
19241 Parameter_Specifications (Acc_Def),
19242 Result_Definition => Result_Definition (Acc_Def));
19245 Make_Access_Procedure_Definition (Loc,
19246 Parameter_Specifications =>
19247 Parameter_Specifications (Acc_Def));
19252 Make_Access_To_Object_Definition (Loc,
19253 Subtype_Indication =>
19256 (Access_Definition (Comp_Def))));
19258 Set_Constant_Present
19259 (Type_Def, Constant_Present (Access_Definition (Comp_Def)));
19261 (Type_Def, All_Present (Access_Definition (Comp_Def)));
19264 Set_Null_Exclusion_Present
19266 Null_Exclusion_Present (Access_Definition (Comp_Def)));
19269 Make_Full_Type_Declaration (Loc,
19270 Defining_Identifier => Anon_Access,
19271 Type_Definition => Type_Def);
19273 Insert_Before (Typ_Decl, Decl);
19276 -- If an access to subprogram, create the extra formals
19278 if Present (Acc_Def) then
19279 Create_Extra_Formals (Designated_Type (Anon_Access));
19281 -- If an access to object, preserve entity of designated type,
19282 -- for ASIS use, before rewriting the component definition.
19289 Desig := Entity (Subtype_Indication (Type_Def));
19291 -- If the access definition is to the current record,
19292 -- the visible entity at this point is an incomplete
19293 -- type. Retrieve the full view to simplify ASIS queries
19295 if Ekind (Desig) = E_Incomplete_Type then
19296 Desig := Full_View (Desig);
19300 (Subtype_Mark (Access_Definition (Comp_Def)), Desig);
19305 Make_Component_Definition (Loc,
19306 Subtype_Indication =>
19307 New_Occurrence_Of (Anon_Access, Loc)));
19309 if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then
19310 Set_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type);
19312 Set_Ekind (Anon_Access, E_Anonymous_Access_Type);
19315 Set_Is_Local_Anonymous_Access (Anon_Access);
19321 if Present (Variant_Part (Comp_List)) then
19325 V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
19326 while Present (V) loop
19327 Check_Anonymous_Access_Components
19328 (Typ_Decl, Typ, Prev, Component_List (V));
19329 Next_Non_Pragma (V);
19333 end Check_Anonymous_Access_Components;
19335 --------------------------------
19336 -- Preanalyze_Spec_Expression --
19337 --------------------------------
19339 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is
19340 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
19342 In_Spec_Expression := True;
19343 Preanalyze_And_Resolve (N, T);
19344 In_Spec_Expression := Save_In_Spec_Expression;
19345 end Preanalyze_Spec_Expression;
19347 -----------------------------
19348 -- Record_Type_Declaration --
19349 -----------------------------
19351 procedure Record_Type_Declaration
19356 Def : constant Node_Id := Type_Definition (N);
19357 Is_Tagged : Boolean;
19358 Tag_Comp : Entity_Id;
19361 -- These flags must be initialized before calling Process_Discriminants
19362 -- because this routine makes use of them.
19364 Set_Ekind (T, E_Record_Type);
19366 Init_Size_Align (T);
19367 Set_Interfaces (T, No_Elist);
19368 Set_Stored_Constraint (T, No_Elist);
19372 if Ada_Version < Ada_2005
19373 or else not Interface_Present (Def)
19375 if Limited_Present (Def) then
19376 Check_SPARK_Restriction ("limited is not allowed", N);
19379 if Abstract_Present (Def) then
19380 Check_SPARK_Restriction ("abstract is not allowed", N);
19383 -- The flag Is_Tagged_Type might have already been set by
19384 -- Find_Type_Name if it detected an error for declaration T. This
19385 -- arises in the case of private tagged types where the full view
19386 -- omits the word tagged.
19389 Tagged_Present (Def)
19390 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
19392 Set_Is_Tagged_Type (T, Is_Tagged);
19393 Set_Is_Limited_Record (T, Limited_Present (Def));
19395 -- Type is abstract if full declaration carries keyword, or if
19396 -- previous partial view did.
19398 Set_Is_Abstract_Type (T, Is_Abstract_Type (T)
19399 or else Abstract_Present (Def));
19402 Check_SPARK_Restriction ("interface is not allowed", N);
19405 Analyze_Interface_Declaration (T, Def);
19407 if Present (Discriminant_Specifications (N)) then
19409 ("interface types cannot have discriminants",
19410 Defining_Identifier
19411 (First (Discriminant_Specifications (N))));
19415 -- First pass: if there are self-referential access components,
19416 -- create the required anonymous access type declarations, and if
19417 -- need be an incomplete type declaration for T itself.
19419 Check_Anonymous_Access_Components (N, T, Prev, Component_List (Def));
19421 if Ada_Version >= Ada_2005
19422 and then Present (Interface_List (Def))
19424 Check_Interfaces (N, Def);
19427 Ifaces_List : Elist_Id;
19430 -- Ada 2005 (AI-251): Collect the list of progenitors that are not
19431 -- already in the parents.
19435 Ifaces_List => Ifaces_List,
19436 Exclude_Parents => True);
19438 Set_Interfaces (T, Ifaces_List);
19442 -- Records constitute a scope for the component declarations within.
19443 -- The scope is created prior to the processing of these declarations.
19444 -- Discriminants are processed first, so that they are visible when
19445 -- processing the other components. The Ekind of the record type itself
19446 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
19448 -- Enter record scope
19452 -- If an incomplete or private type declaration was already given for
19453 -- the type, then this scope already exists, and the discriminants have
19454 -- been declared within. We must verify that the full declaration
19455 -- matches the incomplete one.
19457 Check_Or_Process_Discriminants (N, T, Prev);
19459 Set_Is_Constrained (T, not Has_Discriminants (T));
19460 Set_Has_Delayed_Freeze (T, True);
19462 -- For tagged types add a manually analyzed component corresponding
19463 -- to the component _tag, the corresponding piece of tree will be
19464 -- expanded as part of the freezing actions if it is not a CPP_Class.
19468 -- Do not add the tag unless we are in expansion mode
19470 if Expander_Active then
19471 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
19472 Enter_Name (Tag_Comp);
19474 Set_Ekind (Tag_Comp, E_Component);
19475 Set_Is_Tag (Tag_Comp);
19476 Set_Is_Aliased (Tag_Comp);
19477 Set_Etype (Tag_Comp, RTE (RE_Tag));
19478 Set_DT_Entry_Count (Tag_Comp, No_Uint);
19479 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
19480 Init_Component_Location (Tag_Comp);
19482 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
19483 -- implemented interfaces.
19485 if Has_Interfaces (T) then
19486 Add_Interface_Tag_Components (N, T);
19490 Make_Class_Wide_Type (T);
19491 Set_Direct_Primitive_Operations (T, New_Elmt_List);
19494 -- We must suppress range checks when processing record components in
19495 -- the presence of discriminants, since we don't want spurious checks to
19496 -- be generated during their analysis, but Suppress_Range_Checks flags
19497 -- must be reset the after processing the record definition.
19499 -- Note: this is the only use of Kill_Range_Checks, and is a bit odd,
19500 -- couldn't we just use the normal range check suppression method here.
19501 -- That would seem cleaner ???
19503 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
19504 Set_Kill_Range_Checks (T, True);
19505 Record_Type_Definition (Def, Prev);
19506 Set_Kill_Range_Checks (T, False);
19508 Record_Type_Definition (Def, Prev);
19511 -- Exit from record scope
19515 -- Ada 2005 (AI-251 and AI-345): Derive the interface subprograms of all
19516 -- the implemented interfaces and associate them an aliased entity.
19519 and then not Is_Empty_List (Interface_List (Def))
19521 Derive_Progenitor_Subprograms (T, T);
19523 end Record_Type_Declaration;
19525 ----------------------------
19526 -- Record_Type_Definition --
19527 ----------------------------
19529 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
19530 Component : Entity_Id;
19531 Ctrl_Components : Boolean := False;
19532 Final_Storage_Only : Boolean;
19536 if Ekind (Prev_T) = E_Incomplete_Type then
19537 T := Full_View (Prev_T);
19542 -- In SPARK, tagged types and type extensions may only be declared in
19543 -- the specification of library unit packages.
19545 if Present (Def) and then Is_Tagged_Type (T) then
19551 if Nkind (Parent (Def)) = N_Full_Type_Declaration then
19552 Typ := Parent (Def);
19555 (Nkind (Parent (Def)) = N_Derived_Type_Definition);
19556 Typ := Parent (Parent (Def));
19559 Ctxt := Parent (Typ);
19561 if Nkind (Ctxt) = N_Package_Body
19562 and then Nkind (Parent (Ctxt)) = N_Compilation_Unit
19564 Check_SPARK_Restriction
19565 ("type should be defined in package specification", Typ);
19567 elsif Nkind (Ctxt) /= N_Package_Specification
19568 or else Nkind (Parent (Parent (Ctxt))) /= N_Compilation_Unit
19570 Check_SPARK_Restriction
19571 ("type should be defined in library unit package", Typ);
19576 Final_Storage_Only := not Is_Controlled (T);
19578 -- Ada 2005: check whether an explicit Limited is present in a derived
19579 -- type declaration.
19581 if Nkind (Parent (Def)) = N_Derived_Type_Definition
19582 and then Limited_Present (Parent (Def))
19584 Set_Is_Limited_Record (T);
19587 -- If the component list of a record type is defined by the reserved
19588 -- word null and there is no discriminant part, then the record type has
19589 -- no components and all records of the type are null records (RM 3.7)
19590 -- This procedure is also called to process the extension part of a
19591 -- record extension, in which case the current scope may have inherited
19595 or else No (Component_List (Def))
19596 or else Null_Present (Component_List (Def))
19598 if not Is_Tagged_Type (T) then
19599 Check_SPARK_Restriction ("non-tagged record cannot be null", Def);
19603 Analyze_Declarations (Component_Items (Component_List (Def)));
19605 if Present (Variant_Part (Component_List (Def))) then
19606 Check_SPARK_Restriction ("variant part is not allowed", Def);
19607 Analyze (Variant_Part (Component_List (Def)));
19611 -- After completing the semantic analysis of the record definition,
19612 -- record components, both new and inherited, are accessible. Set their
19613 -- kind accordingly. Exclude malformed itypes from illegal declarations,
19614 -- whose Ekind may be void.
19616 Component := First_Entity (Current_Scope);
19617 while Present (Component) loop
19618 if Ekind (Component) = E_Void
19619 and then not Is_Itype (Component)
19621 Set_Ekind (Component, E_Component);
19622 Init_Component_Location (Component);
19625 if Has_Task (Etype (Component)) then
19629 if Ekind (Component) /= E_Component then
19632 -- Do not set Has_Controlled_Component on a class-wide equivalent
19633 -- type. See Make_CW_Equivalent_Type.
19635 elsif not Is_Class_Wide_Equivalent_Type (T)
19636 and then (Has_Controlled_Component (Etype (Component))
19637 or else (Chars (Component) /= Name_uParent
19638 and then Is_Controlled (Etype (Component))))
19640 Set_Has_Controlled_Component (T, True);
19641 Final_Storage_Only :=
19643 and then Finalize_Storage_Only (Etype (Component));
19644 Ctrl_Components := True;
19647 Next_Entity (Component);
19650 -- A Type is Finalize_Storage_Only only if all its controlled components
19653 if Ctrl_Components then
19654 Set_Finalize_Storage_Only (T, Final_Storage_Only);
19657 -- Place reference to end record on the proper entity, which may
19658 -- be a partial view.
19660 if Present (Def) then
19661 Process_End_Label (Def, 'e', Prev_T);
19663 end Record_Type_Definition;
19665 ------------------------
19666 -- Replace_Components --
19667 ------------------------
19669 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
19670 function Process (N : Node_Id) return Traverse_Result;
19676 function Process (N : Node_Id) return Traverse_Result is
19680 if Nkind (N) = N_Discriminant_Specification then
19681 Comp := First_Discriminant (Typ);
19682 while Present (Comp) loop
19683 if Chars (Comp) = Chars (Defining_Identifier (N)) then
19684 Set_Defining_Identifier (N, Comp);
19688 Next_Discriminant (Comp);
19691 elsif Nkind (N) = N_Component_Declaration then
19692 Comp := First_Component (Typ);
19693 while Present (Comp) loop
19694 if Chars (Comp) = Chars (Defining_Identifier (N)) then
19695 Set_Defining_Identifier (N, Comp);
19699 Next_Component (Comp);
19706 procedure Replace is new Traverse_Proc (Process);
19708 -- Start of processing for Replace_Components
19712 end Replace_Components;
19714 -------------------------------
19715 -- Set_Completion_Referenced --
19716 -------------------------------
19718 procedure Set_Completion_Referenced (E : Entity_Id) is
19720 -- If in main unit, mark entity that is a completion as referenced,
19721 -- warnings go on the partial view when needed.
19723 if In_Extended_Main_Source_Unit (E) then
19724 Set_Referenced (E);
19726 end Set_Completion_Referenced;
19728 ---------------------
19729 -- Set_Fixed_Range --
19730 ---------------------
19732 -- The range for fixed-point types is complicated by the fact that we
19733 -- do not know the exact end points at the time of the declaration. This
19734 -- is true for three reasons:
19736 -- A size clause may affect the fudging of the end-points.
19737 -- A small clause may affect the values of the end-points.
19738 -- We try to include the end-points if it does not affect the size.
19740 -- This means that the actual end-points must be established at the
19741 -- point when the type is frozen. Meanwhile, we first narrow the range
19742 -- as permitted (so that it will fit if necessary in a small specified
19743 -- size), and then build a range subtree with these narrowed bounds.
19744 -- Set_Fixed_Range constructs the range from real literal values, and
19745 -- sets the range as the Scalar_Range of the given fixed-point type entity.
19747 -- The parent of this range is set to point to the entity so that it is
19748 -- properly hooked into the tree (unlike normal Scalar_Range entries for
19749 -- other scalar types, which are just pointers to the range in the
19750 -- original tree, this would otherwise be an orphan).
19752 -- The tree is left unanalyzed. When the type is frozen, the processing
19753 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
19754 -- analyzed, and uses this as an indication that it should complete
19755 -- work on the range (it will know the final small and size values).
19757 procedure Set_Fixed_Range
19763 S : constant Node_Id :=
19765 Low_Bound => Make_Real_Literal (Loc, Lo),
19766 High_Bound => Make_Real_Literal (Loc, Hi));
19768 Set_Scalar_Range (E, S);
19771 -- Before the freeze point, the bounds of a fixed point are universal
19772 -- and carry the corresponding type.
19774 Set_Etype (Low_Bound (S), Universal_Real);
19775 Set_Etype (High_Bound (S), Universal_Real);
19776 end Set_Fixed_Range;
19778 ----------------------------------
19779 -- Set_Scalar_Range_For_Subtype --
19780 ----------------------------------
19782 procedure Set_Scalar_Range_For_Subtype
19783 (Def_Id : Entity_Id;
19787 Kind : constant Entity_Kind := Ekind (Def_Id);
19790 -- Defend against previous error
19792 if Nkind (R) = N_Error then
19796 Set_Scalar_Range (Def_Id, R);
19798 -- We need to link the range into the tree before resolving it so
19799 -- that types that are referenced, including importantly the subtype
19800 -- itself, are properly frozen (Freeze_Expression requires that the
19801 -- expression be properly linked into the tree). Of course if it is
19802 -- already linked in, then we do not disturb the current link.
19804 if No (Parent (R)) then
19805 Set_Parent (R, Def_Id);
19808 -- Reset the kind of the subtype during analysis of the range, to
19809 -- catch possible premature use in the bounds themselves.
19811 Set_Ekind (Def_Id, E_Void);
19812 Process_Range_Expr_In_Decl (R, Subt);
19813 Set_Ekind (Def_Id, Kind);
19814 end Set_Scalar_Range_For_Subtype;
19816 --------------------------------------------------------
19817 -- Set_Stored_Constraint_From_Discriminant_Constraint --
19818 --------------------------------------------------------
19820 procedure Set_Stored_Constraint_From_Discriminant_Constraint
19824 -- Make sure set if encountered during Expand_To_Stored_Constraint
19826 Set_Stored_Constraint (E, No_Elist);
19828 -- Give it the right value
19830 if Is_Constrained (E) and then Has_Discriminants (E) then
19831 Set_Stored_Constraint (E,
19832 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
19834 end Set_Stored_Constraint_From_Discriminant_Constraint;
19836 -------------------------------------
19837 -- Signed_Integer_Type_Declaration --
19838 -------------------------------------
19840 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
19841 Implicit_Base : Entity_Id;
19842 Base_Typ : Entity_Id;
19845 Errs : Boolean := False;
19849 function Can_Derive_From (E : Entity_Id) return Boolean;
19850 -- Determine whether given bounds allow derivation from specified type
19852 procedure Check_Bound (Expr : Node_Id);
19853 -- Check bound to make sure it is integral and static. If not, post
19854 -- appropriate error message and set Errs flag
19856 ---------------------
19857 -- Can_Derive_From --
19858 ---------------------
19860 -- Note we check both bounds against both end values, to deal with
19861 -- strange types like ones with a range of 0 .. -12341234.
19863 function Can_Derive_From (E : Entity_Id) return Boolean is
19864 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
19865 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
19867 return Lo <= Lo_Val and then Lo_Val <= Hi
19869 Lo <= Hi_Val and then Hi_Val <= Hi;
19870 end Can_Derive_From;
19876 procedure Check_Bound (Expr : Node_Id) is
19878 -- If a range constraint is used as an integer type definition, each
19879 -- bound of the range must be defined by a static expression of some
19880 -- integer type, but the two bounds need not have the same integer
19881 -- type (Negative bounds are allowed.) (RM 3.5.4)
19883 if not Is_Integer_Type (Etype (Expr)) then
19885 ("integer type definition bounds must be of integer type", Expr);
19888 elsif not Is_OK_Static_Expression (Expr) then
19889 Flag_Non_Static_Expr
19890 ("non-static expression used for integer type bound!", Expr);
19893 -- The bounds are folded into literals, and we set their type to be
19894 -- universal, to avoid typing difficulties: we cannot set the type
19895 -- of the literal to the new type, because this would be a forward
19896 -- reference for the back end, and if the original type is user-
19897 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
19900 if Is_Entity_Name (Expr) then
19901 Fold_Uint (Expr, Expr_Value (Expr), True);
19904 Set_Etype (Expr, Universal_Integer);
19908 -- Start of processing for Signed_Integer_Type_Declaration
19911 -- Create an anonymous base type
19914 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
19916 -- Analyze and check the bounds, they can be of any integer type
19918 Lo := Low_Bound (Def);
19919 Hi := High_Bound (Def);
19921 -- Arbitrarily use Integer as the type if either bound had an error
19923 if Hi = Error or else Lo = Error then
19924 Base_Typ := Any_Integer;
19925 Set_Error_Posted (T, True);
19927 -- Here both bounds are OK expressions
19930 Analyze_And_Resolve (Lo, Any_Integer);
19931 Analyze_And_Resolve (Hi, Any_Integer);
19937 Hi := Type_High_Bound (Standard_Long_Long_Integer);
19938 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
19941 -- Find type to derive from
19943 Lo_Val := Expr_Value (Lo);
19944 Hi_Val := Expr_Value (Hi);
19946 if Can_Derive_From (Standard_Short_Short_Integer) then
19947 Base_Typ := Base_Type (Standard_Short_Short_Integer);
19949 elsif Can_Derive_From (Standard_Short_Integer) then
19950 Base_Typ := Base_Type (Standard_Short_Integer);
19952 elsif Can_Derive_From (Standard_Integer) then
19953 Base_Typ := Base_Type (Standard_Integer);
19955 elsif Can_Derive_From (Standard_Long_Integer) then
19956 Base_Typ := Base_Type (Standard_Long_Integer);
19958 elsif Can_Derive_From (Standard_Long_Long_Integer) then
19959 Base_Typ := Base_Type (Standard_Long_Long_Integer);
19962 Base_Typ := Base_Type (Standard_Long_Long_Integer);
19963 Error_Msg_N ("integer type definition bounds out of range", Def);
19964 Hi := Type_High_Bound (Standard_Long_Long_Integer);
19965 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
19969 -- Complete both implicit base and declared first subtype entities
19971 Set_Etype (Implicit_Base, Base_Typ);
19972 Set_Size_Info (Implicit_Base, (Base_Typ));
19973 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
19974 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
19976 Set_Ekind (T, E_Signed_Integer_Subtype);
19977 Set_Etype (T, Implicit_Base);
19979 -- In formal verification mode, restrict the base type's range to the
19980 -- minimum allowed by RM 3.5.4, namely the smallest symmetric range
19981 -- around zero with a possible extra negative value that contains the
19982 -- subtype range. Keep Size, RM_Size and First_Rep_Item info, which
19983 -- should not be relied upon in formal verification.
19985 if Strict_Alfa_Mode then
19989 Dloc : constant Source_Ptr := Sloc (Def);
19995 -- If the subtype range is empty, the smallest base type range
19996 -- is the symmetric range around zero containing Lo_Val and
19999 if UI_Gt (Lo_Val, Hi_Val) then
20000 Sym_Hi_Val := UI_Max (UI_Abs (Lo_Val), UI_Abs (Hi_Val));
20001 Sym_Lo_Val := UI_Negate (Sym_Hi_Val);
20003 -- Otherwise, if the subtype range is not empty and Hi_Val has
20004 -- the largest absolute value, Hi_Val is non negative and the
20005 -- smallest base type range is the symmetric range around zero
20006 -- containing Hi_Val.
20008 elsif UI_Le (UI_Abs (Lo_Val), UI_Abs (Hi_Val)) then
20009 Sym_Hi_Val := Hi_Val;
20010 Sym_Lo_Val := UI_Negate (Hi_Val);
20012 -- Otherwise, the subtype range is not empty, Lo_Val has the
20013 -- strictly largest absolute value, Lo_Val is negative and the
20014 -- smallest base type range is the symmetric range around zero
20015 -- with an extra negative value Lo_Val.
20018 Sym_Lo_Val := Lo_Val;
20019 Sym_Hi_Val := UI_Sub (UI_Negate (Lo_Val), Uint_1);
20022 Lbound := Make_Integer_Literal (Dloc, Sym_Lo_Val);
20023 Ubound := Make_Integer_Literal (Dloc, Sym_Hi_Val);
20024 Set_Is_Static_Expression (Lbound);
20025 Set_Is_Static_Expression (Ubound);
20026 Analyze_And_Resolve (Lbound, Any_Integer);
20027 Analyze_And_Resolve (Ubound, Any_Integer);
20029 Bounds := Make_Range (Dloc, Lbound, Ubound);
20030 Set_Etype (Bounds, Base_Typ);
20032 Set_Scalar_Range (Implicit_Base, Bounds);
20036 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
20039 Set_Size_Info (T, (Implicit_Base));
20040 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
20041 Set_Scalar_Range (T, Def);
20042 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
20043 Set_Is_Constrained (T);
20044 end Signed_Integer_Type_Declaration;