1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2013, 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 Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Elists; use Elists;
31 with Einfo; use Einfo;
32 with Errout; use Errout;
33 with Eval_Fat; use Eval_Fat;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch9; use Exp_Ch9;
36 with Exp_Disp; use Exp_Disp;
37 with Exp_Dist; use Exp_Dist;
38 with Exp_Pakd; use Exp_Pakd;
39 with Exp_Tss; use Exp_Tss;
40 with Exp_Util; use Exp_Util;
41 with Fname; use Fname;
42 with Freeze; use Freeze;
43 with Itypes; use Itypes;
44 with Layout; use Layout;
46 with Lib.Xref; use Lib.Xref;
47 with Namet; use Namet;
48 with Nmake; use Nmake;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
54 with Sem_Aux; use Sem_Aux;
55 with Sem_Case; use Sem_Case;
56 with Sem_Cat; use Sem_Cat;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch7; use Sem_Ch7;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Dim; use Sem_Dim;
62 with Sem_Disp; use Sem_Disp;
63 with Sem_Dist; use Sem_Dist;
64 with Sem_Elim; use Sem_Elim;
65 with Sem_Eval; use Sem_Eval;
66 with Sem_Mech; use Sem_Mech;
67 with Sem_Prag; use Sem_Prag;
68 with Sem_Res; use Sem_Res;
69 with Sem_Smem; use Sem_Smem;
70 with Sem_Type; use Sem_Type;
71 with Sem_Util; use Sem_Util;
72 with Sem_Warn; use Sem_Warn;
73 with Stand; use Stand;
74 with Sinfo; use Sinfo;
75 with Sinput; use Sinput;
76 with Snames; use Snames;
77 with Targparm; use Targparm;
78 with Tbuild; use Tbuild;
79 with Ttypes; use Ttypes;
80 with Uintp; use Uintp;
81 with Urealp; use Urealp;
83 package body Sem_Ch3 is
85 -----------------------
86 -- Local Subprograms --
87 -----------------------
89 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id);
90 -- Ada 2005 (AI-251): Add the tag components corresponding to all the
91 -- abstract interface types implemented by a record type or a derived
94 procedure Build_Derived_Type
96 Parent_Type : Entity_Id;
97 Derived_Type : Entity_Id;
98 Is_Completion : Boolean;
99 Derive_Subps : Boolean := True);
100 -- Create and decorate a Derived_Type given the Parent_Type entity. N is
101 -- the N_Full_Type_Declaration node containing the derived type definition.
102 -- Parent_Type is the entity for the parent type in the derived type
103 -- definition and Derived_Type the actual derived type. Is_Completion must
104 -- be set to False if Derived_Type is the N_Defining_Identifier node in N
105 -- (i.e. Derived_Type = Defining_Identifier (N)). In this case N is not the
106 -- completion of a private type declaration. If Is_Completion is set to
107 -- True, N is the completion of a private type declaration and Derived_Type
108 -- is different from the defining identifier inside N (i.e. Derived_Type /=
109 -- Defining_Identifier (N)). Derive_Subps indicates whether the parent
110 -- subprograms should be derived. The only case where this parameter is
111 -- False is when Build_Derived_Type is recursively called to process an
112 -- implicit derived full type for a type derived from a private type (in
113 -- that case the subprograms must only be derived for the private view of
116 -- ??? These flags need a bit of re-examination and re-documentation:
117 -- ??? are they both necessary (both seem related to the recursion)?
119 procedure Build_Derived_Access_Type
121 Parent_Type : Entity_Id;
122 Derived_Type : Entity_Id);
123 -- Subsidiary procedure to Build_Derived_Type. For a derived access type,
124 -- create an implicit base if the parent type is constrained or if the
125 -- subtype indication has a constraint.
127 procedure Build_Derived_Array_Type
129 Parent_Type : Entity_Id;
130 Derived_Type : Entity_Id);
131 -- Subsidiary procedure to Build_Derived_Type. For a derived array type,
132 -- create an implicit base if the parent type is constrained or if the
133 -- subtype indication has a constraint.
135 procedure Build_Derived_Concurrent_Type
137 Parent_Type : Entity_Id;
138 Derived_Type : Entity_Id);
139 -- Subsidiary procedure to Build_Derived_Type. For a derived task or
140 -- protected type, inherit entries and protected subprograms, check
141 -- legality of discriminant constraints if any.
143 procedure Build_Derived_Enumeration_Type
145 Parent_Type : Entity_Id;
146 Derived_Type : Entity_Id);
147 -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
148 -- type, we must create a new list of literals. Types derived from
149 -- Character and [Wide_]Wide_Character are special-cased.
151 procedure Build_Derived_Numeric_Type
153 Parent_Type : Entity_Id;
154 Derived_Type : Entity_Id);
155 -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
156 -- an anonymous base type, and propagate constraint to subtype if needed.
158 procedure Build_Derived_Private_Type
160 Parent_Type : Entity_Id;
161 Derived_Type : Entity_Id;
162 Is_Completion : Boolean;
163 Derive_Subps : Boolean := True);
164 -- Subsidiary procedure to Build_Derived_Type. This procedure is complex
165 -- because the parent may or may not have a completion, and the derivation
166 -- may itself be a completion.
168 procedure Build_Derived_Record_Type
170 Parent_Type : Entity_Id;
171 Derived_Type : Entity_Id;
172 Derive_Subps : Boolean := True);
173 -- Subsidiary procedure used for tagged and untagged record types
174 -- by Build_Derived_Type and Analyze_Private_Extension_Declaration.
175 -- All parameters are as in Build_Derived_Type except that N, in
176 -- addition to being an N_Full_Type_Declaration node, can also be an
177 -- N_Private_Extension_Declaration node. See the definition of this routine
178 -- for much more info. Derive_Subps indicates whether subprograms should be
179 -- derived from the parent type. The only case where Derive_Subps is False
180 -- is for an implicit derived full type for a type derived from a private
181 -- type (see Build_Derived_Type).
183 procedure Build_Discriminal (Discrim : Entity_Id);
184 -- Create the discriminal corresponding to discriminant Discrim, that is
185 -- the parameter corresponding to Discrim to be used in initialization
186 -- procedures for the type where Discrim is a discriminant. Discriminals
187 -- are not used during semantic analysis, and are not fully defined
188 -- entities until expansion. Thus they are not given a scope until
189 -- initialization procedures are built.
191 function Build_Discriminant_Constraints
194 Derived_Def : Boolean := False) return Elist_Id;
195 -- Validate discriminant constraints and return the list of the constraints
196 -- in order of discriminant declarations, where T is the discriminated
197 -- unconstrained type. Def is the N_Subtype_Indication node where the
198 -- discriminants constraints for T are specified. Derived_Def is True
199 -- when building the discriminant constraints in a derived type definition
200 -- of the form "type D (...) is new T (xxx)". In this case T is the parent
201 -- type and Def is the constraint "(xxx)" on T and this routine sets the
202 -- Corresponding_Discriminant field of the discriminants in the derived
203 -- type D to point to the corresponding discriminants in the parent type T.
205 procedure Build_Discriminated_Subtype
209 Related_Nod : Node_Id;
210 For_Access : Boolean := False);
211 -- Subsidiary procedure to Constrain_Discriminated_Type and to
212 -- Process_Incomplete_Dependents. Given
214 -- T (a possibly discriminated base type)
215 -- Def_Id (a very partially built subtype for T),
217 -- the call completes Def_Id to be the appropriate E_*_Subtype.
219 -- The Elist is the list of discriminant constraints if any (it is set
220 -- to No_Elist if T is not a discriminated type, and to an empty list if
221 -- T has discriminants but there are no discriminant constraints). The
222 -- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
223 -- The For_Access says whether or not this subtype is really constraining
224 -- an access type. That is its sole purpose is the designated type of an
225 -- access type -- in which case a Private_Subtype Is_For_Access_Subtype
226 -- is built to avoid freezing T when the access subtype is frozen.
228 function Build_Scalar_Bound
231 Der_T : Entity_Id) return Node_Id;
232 -- The bounds of a derived scalar type are conversions of the bounds of
233 -- the parent type. Optimize the representation if the bounds are literals.
234 -- Needs a more complete spec--what are the parameters exactly, and what
235 -- exactly is the returned value, and how is Bound affected???
237 procedure Build_Underlying_Full_View
241 -- If the completion of a private type is itself derived from a private
242 -- type, or if the full view of a private subtype is itself private, the
243 -- back-end has no way to compute the actual size of this type. We build
244 -- an internal subtype declaration of the proper parent type to convey
245 -- this information. This extra mechanism is needed because a full
246 -- view cannot itself have a full view (it would get clobbered during
249 procedure Check_Access_Discriminant_Requires_Limited
252 -- Check the restriction that the type to which an access discriminant
253 -- belongs must be a concurrent type or a descendant of a type with
254 -- the reserved word 'limited' in its declaration.
256 procedure Check_Anonymous_Access_Components
260 Comp_List : Node_Id);
261 -- Ada 2005 AI-382: an access component in a record definition can refer to
262 -- the enclosing record, in which case it denotes the type itself, and not
263 -- the current instance of the type. We create an anonymous access type for
264 -- the component, and flag it as an access to a component, so accessibility
265 -- checks are properly performed on it. The declaration of the access type
266 -- is placed ahead of that of the record to prevent order-of-elaboration
267 -- circularity issues in Gigi. We create an incomplete type for the record
268 -- declaration, which is the designated type of the anonymous access.
270 procedure Check_Delta_Expression (E : Node_Id);
271 -- Check that the expression represented by E is suitable for use as a
272 -- delta expression, i.e. it is of real type and is static.
274 procedure Check_Digits_Expression (E : Node_Id);
275 -- Check that the expression represented by E is suitable for use as a
276 -- digits expression, i.e. it is of integer type, positive and static.
278 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
279 -- Validate the initialization of an object declaration. T is the required
280 -- type, and Exp is the initialization expression.
282 procedure Check_Interfaces (N : Node_Id; Def : Node_Id);
283 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
285 procedure Check_Or_Process_Discriminants
288 Prev : Entity_Id := Empty);
289 -- If N is the full declaration of the completion T of an incomplete or
290 -- private type, check its discriminants (which are already known to be
291 -- conformant with those of the partial view, see Find_Type_Name),
292 -- otherwise process them. Prev is the entity of the partial declaration,
295 procedure Check_Real_Bound (Bound : Node_Id);
296 -- Check given bound for being of real type and static. If not, post an
297 -- appropriate message, and rewrite the bound with the real literal zero.
299 procedure Constant_Redeclaration
303 -- Various checks on legality of full declaration of deferred constant.
304 -- Id is the entity for the redeclaration, N is the N_Object_Declaration,
305 -- node. The caller has not yet set any attributes of this entity.
307 function Contain_Interface
309 Ifaces : Elist_Id) return Boolean;
310 -- Ada 2005: Determine whether Iface is present in the list Ifaces
312 procedure Convert_Scalar_Bounds
314 Parent_Type : Entity_Id;
315 Derived_Type : Entity_Id;
317 -- For derived scalar types, convert the bounds in the type definition to
318 -- the derived type, and complete their analysis. Given a constraint of the
319 -- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with
320 -- T'Base, the parent_type. The bounds of the derived type (the anonymous
321 -- base) are copies of Lo and Hi. Finally, the bounds of the derived
322 -- subtype are conversions of those bounds to the derived_type, so that
323 -- their typing is consistent.
325 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
326 -- Copies attributes from array base type T2 to array base type T1. Copies
327 -- only attributes that apply to base types, but not subtypes.
329 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
330 -- Copies attributes from array subtype T2 to array subtype T1. Copies
331 -- attributes that apply to both subtypes and base types.
333 procedure Create_Constrained_Components
337 Constraints : Elist_Id);
338 -- Build the list of entities for a constrained discriminated record
339 -- subtype. If a component depends on a discriminant, replace its subtype
340 -- using the discriminant values in the discriminant constraint. Subt
341 -- is the defining identifier for the subtype whose list of constrained
342 -- entities we will create. Decl_Node is the type declaration node where
343 -- we will attach all the itypes created. Typ is the base discriminated
344 -- type for the subtype Subt. Constraints is the list of discriminant
345 -- constraints for Typ.
347 function Constrain_Component_Type
349 Constrained_Typ : Entity_Id;
350 Related_Node : Node_Id;
352 Constraints : Elist_Id) return Entity_Id;
353 -- Given a discriminated base type Typ, a list of discriminant constraint
354 -- Constraints for Typ and a component of Typ, with type Compon_Type,
355 -- create and return the type corresponding to Compon_type where all
356 -- discriminant references are replaced with the corresponding constraint.
357 -- If no discriminant references occur in Compon_Typ then return it as is.
358 -- Constrained_Typ is the final constrained subtype to which the
359 -- constrained Compon_Type belongs. Related_Node is the node where we will
360 -- attach all the itypes created.
362 -- Above description is confused, what is Compon_Type???
364 procedure Constrain_Access
365 (Def_Id : in out Entity_Id;
367 Related_Nod : Node_Id);
368 -- Apply a list of constraints to an access type. If Def_Id is empty, it is
369 -- an anonymous type created for a subtype indication. In that case it is
370 -- created in the procedure and attached to Related_Nod.
372 procedure Constrain_Array
373 (Def_Id : in out Entity_Id;
375 Related_Nod : Node_Id;
376 Related_Id : Entity_Id;
378 -- Apply a list of index constraints to an unconstrained array type. The
379 -- first parameter is the entity for the resulting subtype. A value of
380 -- Empty for Def_Id indicates that an implicit type must be created, but
381 -- creation is delayed (and must be done by this procedure) because other
382 -- subsidiary implicit types must be created first (which is why Def_Id
383 -- is an in/out parameter). The second parameter is a subtype indication
384 -- node for the constrained array to be created (e.g. something of the
385 -- form string (1 .. 10)). Related_Nod gives the place where this type
386 -- has to be inserted in the tree. The Related_Id and Suffix parameters
387 -- are used to build the associated Implicit type name.
389 procedure Constrain_Concurrent
390 (Def_Id : in out Entity_Id;
392 Related_Nod : Node_Id;
393 Related_Id : Entity_Id;
395 -- Apply list of discriminant constraints to an unconstrained concurrent
398 -- SI is the N_Subtype_Indication node containing the constraint and
399 -- the unconstrained type to constrain.
401 -- Def_Id is the entity for the resulting constrained subtype. A value
402 -- of Empty for Def_Id indicates that an implicit type must be created,
403 -- but creation is delayed (and must be done by this procedure) because
404 -- other subsidiary implicit types must be created first (which is why
405 -- Def_Id is an in/out parameter).
407 -- Related_Nod gives the place where this type has to be inserted
410 -- The last two arguments are used to create its external name if needed.
412 function Constrain_Corresponding_Record
413 (Prot_Subt : Entity_Id;
414 Corr_Rec : Entity_Id;
415 Related_Nod : Node_Id;
416 Related_Id : Entity_Id) return Entity_Id;
417 -- When constraining a protected type or task type with discriminants,
418 -- constrain the corresponding record with the same discriminant values.
420 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
421 -- Constrain a decimal fixed point type with a digits constraint and/or a
422 -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
424 procedure Constrain_Discriminated_Type
427 Related_Nod : Node_Id;
428 For_Access : Boolean := False);
429 -- Process discriminant constraints of composite type. Verify that values
430 -- have been provided for all discriminants, that the original type is
431 -- unconstrained, and that the types of the supplied expressions match
432 -- the discriminant types. The first three parameters are like in routine
433 -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
436 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
437 -- Constrain an enumeration type with a range constraint. This is identical
438 -- to Constrain_Integer, but for the Ekind of the resulting subtype.
440 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
441 -- Constrain a floating point type with either a digits constraint
442 -- and/or a range constraint, building a E_Floating_Point_Subtype.
444 procedure Constrain_Index
447 Related_Nod : Node_Id;
448 Related_Id : Entity_Id;
451 -- Process an index constraint S in a constrained array declaration. The
452 -- constraint can be a subtype name, or a range with or without an explicit
453 -- subtype mark. The index is the corresponding index of the unconstrained
454 -- array. The Related_Id and Suffix parameters are used to build the
455 -- associated Implicit type name.
457 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
458 -- Build subtype of a signed or modular integer type
460 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
461 -- Constrain an ordinary fixed point type with a range constraint, and
462 -- build an E_Ordinary_Fixed_Point_Subtype entity.
464 procedure Copy_And_Swap (Priv, Full : Entity_Id);
465 -- Copy the Priv entity into the entity of its full declaration then swap
466 -- the two entities in such a manner that the former private type is now
467 -- seen as a full type.
469 procedure Decimal_Fixed_Point_Type_Declaration
472 -- Create a new decimal fixed point type, and apply the constraint to
473 -- obtain a subtype of this new type.
475 procedure Complete_Private_Subtype
478 Full_Base : Entity_Id;
479 Related_Nod : Node_Id);
480 -- Complete the implicit full view of a private subtype by setting the
481 -- appropriate semantic fields. If the full view of the parent is a record
482 -- type, build constrained components of subtype.
484 procedure Derive_Progenitor_Subprograms
485 (Parent_Type : Entity_Id;
486 Tagged_Type : Entity_Id);
487 -- Ada 2005 (AI-251): To complete type derivation, collect the primitive
488 -- operations of progenitors of Tagged_Type, and replace the subsidiary
489 -- subtypes with Tagged_Type, to build the specs of the inherited interface
490 -- primitives. The derived primitives are aliased to those of the
491 -- interface. This routine takes care also of transferring to the full view
492 -- subprograms associated with the partial view of Tagged_Type that cover
493 -- interface primitives.
495 procedure Derived_Standard_Character
497 Parent_Type : Entity_Id;
498 Derived_Type : Entity_Id);
499 -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
500 -- derivations from types Standard.Character and Standard.Wide_Character.
502 procedure Derived_Type_Declaration
505 Is_Completion : Boolean);
506 -- Process a derived type declaration. Build_Derived_Type is invoked
507 -- to process the actual derived type definition. Parameters N and
508 -- Is_Completion have the same meaning as in Build_Derived_Type.
509 -- T is the N_Defining_Identifier for the entity defined in the
510 -- N_Full_Type_Declaration node N, that is T is the derived type.
512 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
513 -- Insert each literal in symbol table, as an overloadable identifier. Each
514 -- enumeration type is mapped into a sequence of integers, and each literal
515 -- is defined as a constant with integer value. If any of the literals are
516 -- character literals, the type is a character type, which means that
517 -- strings are legal aggregates for arrays of components of the type.
519 function Expand_To_Stored_Constraint
521 Constraint : Elist_Id) return Elist_Id;
522 -- Given a constraint (i.e. a list of expressions) on the discriminants of
523 -- Typ, expand it into a constraint on the stored discriminants and return
524 -- the new list of expressions constraining the stored discriminants.
526 function Find_Type_Of_Object
528 Related_Nod : Node_Id) return Entity_Id;
529 -- Get type entity for object referenced by Obj_Def, attaching the
530 -- implicit types generated to Related_Nod
532 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
533 -- Create a new float and apply the constraint to obtain subtype of it
535 function Has_Range_Constraint (N : Node_Id) return Boolean;
536 -- Given an N_Subtype_Indication node N, return True if a range constraint
537 -- is present, either directly, or as part of a digits or delta constraint.
538 -- In addition, a digits constraint in the decimal case returns True, since
539 -- it establishes a default range if no explicit range is present.
541 function Inherit_Components
543 Parent_Base : Entity_Id;
544 Derived_Base : Entity_Id;
546 Inherit_Discr : Boolean;
547 Discs : Elist_Id) return Elist_Id;
548 -- Called from Build_Derived_Record_Type to inherit the components of
549 -- Parent_Base (a base type) into the Derived_Base (the derived base type).
550 -- For more information on derived types and component inheritance please
551 -- consult the comment above the body of Build_Derived_Record_Type.
553 -- N is the original derived type declaration
555 -- Is_Tagged is set if we are dealing with tagged types
557 -- If Inherit_Discr is set, Derived_Base inherits its discriminants from
558 -- Parent_Base, otherwise no discriminants are inherited.
560 -- Discs gives the list of constraints that apply to Parent_Base in the
561 -- derived type declaration. If Discs is set to No_Elist, then we have
562 -- the following situation:
564 -- type Parent (D1..Dn : ..) is [tagged] record ...;
565 -- type Derived is new Parent [with ...];
567 -- which gets treated as
569 -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
571 -- For untagged types the returned value is an association list. The list
572 -- starts from the association (Parent_Base => Derived_Base), and then it
573 -- contains a sequence of the associations of the form
575 -- (Old_Component => New_Component),
577 -- where Old_Component is the Entity_Id of a component in Parent_Base and
578 -- New_Component is the Entity_Id of the corresponding component in
579 -- Derived_Base. For untagged records, this association list is needed when
580 -- copying the record declaration for the derived base. In the tagged case
581 -- the value returned is irrelevant.
583 function Is_Valid_Constraint_Kind
585 Constraint_Kind : Node_Kind) return Boolean;
586 -- Returns True if it is legal to apply the given kind of constraint to the
587 -- given kind of type (index constraint to an array type, for example).
589 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
590 -- Create new modular type. Verify that modulus is in bounds
592 procedure New_Concatenation_Op (Typ : Entity_Id);
593 -- Create an abbreviated declaration for an operator in order to
594 -- materialize concatenation on array types.
596 procedure Ordinary_Fixed_Point_Type_Declaration
599 -- Create a new ordinary fixed point type, and apply the constraint to
600 -- obtain subtype of it.
602 procedure Prepare_Private_Subtype_Completion
604 Related_Nod : Node_Id);
605 -- Id is a subtype of some private type. Creates the full declaration
606 -- associated with Id whenever possible, i.e. when the full declaration
607 -- of the base type is already known. Records each subtype into
608 -- Private_Dependents of the base type.
610 procedure Process_Incomplete_Dependents
614 -- Process all entities that depend on an incomplete type. There include
615 -- subtypes, subprogram types that mention the incomplete type in their
616 -- profiles, and subprogram with access parameters that designate the
619 -- Inc_T is the defining identifier of an incomplete type declaration, its
620 -- Ekind is E_Incomplete_Type.
622 -- N is the corresponding N_Full_Type_Declaration for Inc_T.
624 -- Full_T is N's defining identifier.
626 -- Subtypes of incomplete types with discriminants are completed when the
627 -- parent type is. This is simpler than private subtypes, because they can
628 -- only appear in the same scope, and there is no need to exchange views.
629 -- Similarly, access_to_subprogram types may have a parameter or a return
630 -- type that is an incomplete type, and that must be replaced with the
633 -- If the full type is tagged, subprogram with access parameters that
634 -- designated the incomplete may be primitive operations of the full type,
635 -- and have to be processed accordingly.
637 procedure Process_Real_Range_Specification (Def : Node_Id);
638 -- Given the type definition for a real type, this procedure processes and
639 -- checks the real range specification of this type definition if one is
640 -- present. If errors are found, error messages are posted, and the
641 -- Real_Range_Specification of Def is reset to Empty.
643 procedure Record_Type_Declaration
647 -- Process a record type declaration (for both untagged and tagged
648 -- records). Parameters T and N are exactly like in procedure
649 -- Derived_Type_Declaration, except that no flag Is_Completion is needed
650 -- for this routine. If this is the completion of an incomplete type
651 -- declaration, Prev is the entity of the incomplete declaration, used for
652 -- cross-referencing. Otherwise Prev = T.
654 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
655 -- This routine is used to process the actual record type definition (both
656 -- for untagged and tagged records). Def is a record type definition node.
657 -- This procedure analyzes the components in this record type definition.
658 -- Prev_T is the entity for the enclosing record type. It is provided so
659 -- that its Has_Task flag can be set if any of the component have Has_Task
660 -- set. If the declaration is the completion of an incomplete type
661 -- declaration, Prev_T is the original incomplete type, whose full view is
664 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
665 -- Subsidiary to Build_Derived_Record_Type. For untagged records, we
666 -- build a copy of the declaration tree of the parent, and we create
667 -- independently the list of components for the derived type. Semantic
668 -- information uses the component entities, but record representation
669 -- clauses are validated on the declaration tree. This procedure replaces
670 -- discriminants and components in the declaration with those that have
671 -- been created by Inherit_Components.
673 procedure Set_Fixed_Range
678 -- Build a range node with the given bounds and set it as the Scalar_Range
679 -- of the given fixed-point type entity. Loc is the source location used
680 -- for the constructed range. See body for further details.
682 procedure Set_Scalar_Range_For_Subtype
686 -- This routine is used to set the scalar range field for a subtype given
687 -- Def_Id, the entity for the subtype, and R, the range expression for the
688 -- scalar range. Subt provides the parent subtype to be used to analyze,
689 -- resolve, and check the given range.
691 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
692 -- Create a new signed integer entity, and apply the constraint to obtain
693 -- the required first named subtype of this type.
695 procedure Set_Stored_Constraint_From_Discriminant_Constraint
697 -- E is some record type. This routine computes E's Stored_Constraint
698 -- from its Discriminant_Constraint.
700 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id);
701 -- Check that an entity in a list of progenitors is an interface,
702 -- emit error otherwise.
704 -----------------------
705 -- Access_Definition --
706 -----------------------
708 function Access_Definition
709 (Related_Nod : Node_Id;
710 N : Node_Id) return Entity_Id
712 Anon_Type : Entity_Id;
713 Anon_Scope : Entity_Id;
714 Desig_Type : Entity_Id;
715 Enclosing_Prot_Type : Entity_Id := Empty;
718 Check_SPARK_Restriction ("access type is not allowed", N);
720 if Is_Entry (Current_Scope)
721 and then Is_Task_Type (Etype (Scope (Current_Scope)))
723 Error_Msg_N ("task entries cannot have access parameters", N);
727 -- Ada 2005: for an object declaration the corresponding anonymous
728 -- type is declared in the current scope.
730 -- If the access definition is the return type of another access to
731 -- function, scope is the current one, because it is the one of the
732 -- current type declaration, except for the pathological case below.
734 if Nkind_In (Related_Nod, N_Object_Declaration,
735 N_Access_Function_Definition)
737 Anon_Scope := Current_Scope;
739 -- A pathological case: function returning access functions that
740 -- return access functions, etc. Each anonymous access type created
741 -- is in the enclosing scope of the outermost function.
748 while Nkind_In (Par, N_Access_Function_Definition,
754 if Nkind (Par) = N_Function_Specification then
755 Anon_Scope := Scope (Defining_Entity (Par));
759 -- For the anonymous function result case, retrieve the scope of the
760 -- function specification's associated entity rather than using the
761 -- current scope. The current scope will be the function itself if the
762 -- formal part is currently being analyzed, but will be the parent scope
763 -- in the case of a parameterless function, and we always want to use
764 -- the function's parent scope. Finally, if the function is a child
765 -- unit, we must traverse the tree to retrieve the proper entity.
767 elsif Nkind (Related_Nod) = N_Function_Specification
768 and then Nkind (Parent (N)) /= N_Parameter_Specification
770 -- If the current scope is a protected type, the anonymous access
771 -- is associated with one of the protected operations, and must
772 -- be available in the scope that encloses the protected declaration.
773 -- Otherwise the type is in the scope enclosing the subprogram.
775 -- If the function has formals, The return type of a subprogram
776 -- declaration is analyzed in the scope of the subprogram (see
777 -- Process_Formals) and thus the protected type, if present, is
778 -- the scope of the current function scope.
780 if Ekind (Current_Scope) = E_Protected_Type then
781 Enclosing_Prot_Type := Current_Scope;
783 elsif Ekind (Current_Scope) = E_Function
784 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
786 Enclosing_Prot_Type := Scope (Current_Scope);
789 if Present (Enclosing_Prot_Type) then
790 Anon_Scope := Scope (Enclosing_Prot_Type);
793 Anon_Scope := Scope (Defining_Entity (Related_Nod));
796 -- For an access type definition, if the current scope is a child
797 -- unit it is the scope of the type.
799 elsif Is_Compilation_Unit (Current_Scope) then
800 Anon_Scope := Current_Scope;
802 -- For access formals, access components, and access discriminants, the
803 -- scope is that of the enclosing declaration,
806 Anon_Scope := Scope (Current_Scope);
811 (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope);
814 and then Ada_Version >= Ada_2005
816 Error_Msg_N ("ALL is not permitted for anonymous access types", N);
819 -- Ada 2005 (AI-254): In case of anonymous access to subprograms call
820 -- the corresponding semantic routine
822 if Present (Access_To_Subprogram_Definition (N)) then
824 -- Compiler runtime units are compiled in Ada 2005 mode when building
825 -- the runtime library but must also be compilable in Ada 95 mode
826 -- (when bootstrapping the compiler).
828 Check_Compiler_Unit (N);
830 Access_Subprogram_Declaration
831 (T_Name => Anon_Type,
832 T_Def => Access_To_Subprogram_Definition (N));
834 if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
836 (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
839 (Anon_Type, E_Anonymous_Access_Subprogram_Type);
842 Set_Can_Use_Internal_Rep
843 (Anon_Type, not Always_Compatible_Rep_On_Target);
845 -- If the anonymous access is associated with a protected operation,
846 -- create a reference to it after the enclosing protected definition
847 -- because the itype will be used in the subsequent bodies.
849 if Ekind (Current_Scope) = E_Protected_Type then
850 Build_Itype_Reference (Anon_Type, Parent (Current_Scope));
856 Find_Type (Subtype_Mark (N));
857 Desig_Type := Entity (Subtype_Mark (N));
859 Set_Directly_Designated_Type (Anon_Type, Desig_Type);
860 Set_Etype (Anon_Type, Anon_Type);
862 -- Make sure the anonymous access type has size and alignment fields
863 -- set, as required by gigi. This is necessary in the case of the
864 -- Task_Body_Procedure.
866 if not Has_Private_Component (Desig_Type) then
867 Layout_Type (Anon_Type);
870 -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
871 -- from Ada 95 semantics. In Ada 2005, anonymous access must specify if
872 -- the null value is allowed. In Ada 95 the null value is never allowed.
874 if Ada_Version >= Ada_2005 then
875 Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
877 Set_Can_Never_Be_Null (Anon_Type, True);
880 -- The anonymous access type is as public as the discriminated type or
881 -- subprogram that defines it. It is imported (for back-end purposes)
882 -- if the designated type is.
884 Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
886 -- Ada 2005 (AI-231): Propagate the access-constant attribute
888 Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
890 -- The context is either a subprogram declaration, object declaration,
891 -- or an access discriminant, in a private or a full type declaration.
892 -- In the case of a subprogram, if the designated type is incomplete,
893 -- the operation will be a primitive operation of the full type, to be
894 -- updated subsequently. If the type is imported through a limited_with
895 -- clause, the subprogram is not a primitive operation of the type
896 -- (which is declared elsewhere in some other scope).
898 if Ekind (Desig_Type) = E_Incomplete_Type
899 and then not From_With_Type (Desig_Type)
900 and then Is_Overloadable (Current_Scope)
902 Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
903 Set_Has_Delayed_Freeze (Current_Scope);
906 -- Ada 2005: if the designated type is an interface that may contain
907 -- tasks, create a Master entity for the declaration. This must be done
908 -- before expansion of the full declaration, because the declaration may
909 -- include an expression that is an allocator, whose expansion needs the
910 -- proper Master for the created tasks.
912 if Nkind (Related_Nod) = N_Object_Declaration
913 and then Expander_Active
915 if Is_Interface (Desig_Type)
916 and then Is_Limited_Record (Desig_Type)
918 Build_Class_Wide_Master (Anon_Type);
920 -- Similarly, if the type is an anonymous access that designates
921 -- tasks, create a master entity for it in the current context.
923 elsif Has_Task (Desig_Type)
924 and then Comes_From_Source (Related_Nod)
926 Build_Master_Entity (Defining_Identifier (Related_Nod));
927 Build_Master_Renaming (Anon_Type);
931 -- For a private component of a protected type, it is imperative that
932 -- the back-end elaborate the type immediately after the protected
933 -- declaration, because this type will be used in the declarations
934 -- created for the component within each protected body, so we must
935 -- create an itype reference for it now.
937 if Nkind (Parent (Related_Nod)) = N_Protected_Definition then
938 Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod)));
940 -- Similarly, if the access definition is the return result of a
941 -- function, create an itype reference for it because it will be used
942 -- within the function body. For a regular function that is not a
943 -- compilation unit, insert reference after the declaration. For a
944 -- protected operation, insert it after the enclosing protected type
945 -- declaration. In either case, do not create a reference for a type
946 -- obtained through a limited_with clause, because this would introduce
947 -- semantic dependencies.
949 -- Similarly, do not create a reference if the designated type is a
950 -- generic formal, because no use of it will reach the backend.
952 elsif Nkind (Related_Nod) = N_Function_Specification
953 and then not From_With_Type (Desig_Type)
954 and then not Is_Generic_Type (Desig_Type)
956 if Present (Enclosing_Prot_Type) then
957 Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type));
959 elsif Is_List_Member (Parent (Related_Nod))
960 and then Nkind (Parent (N)) /= N_Parameter_Specification
962 Build_Itype_Reference (Anon_Type, Parent (Related_Nod));
965 -- Finally, create an itype reference for an object declaration of an
966 -- anonymous access type. This is strictly necessary only for deferred
967 -- constants, but in any case will avoid out-of-scope problems in the
970 elsif Nkind (Related_Nod) = N_Object_Declaration then
971 Build_Itype_Reference (Anon_Type, Related_Nod);
975 end Access_Definition;
977 -----------------------------------
978 -- Access_Subprogram_Declaration --
979 -----------------------------------
981 procedure Access_Subprogram_Declaration
986 procedure Check_For_Premature_Usage (Def : Node_Id);
987 -- Check that type T_Name is not used, directly or recursively, as a
988 -- parameter or a return type in Def. Def is either a subtype, an
989 -- access_definition, or an access_to_subprogram_definition.
991 -------------------------------
992 -- Check_For_Premature_Usage --
993 -------------------------------
995 procedure Check_For_Premature_Usage (Def : Node_Id) is
999 -- Check for a subtype mark
1001 if Nkind (Def) in N_Has_Etype then
1002 if Etype (Def) = T_Name then
1004 ("type& cannot be used before end of its declaration", Def);
1007 -- If this is not a subtype, then this is an access_definition
1009 elsif Nkind (Def) = N_Access_Definition then
1010 if Present (Access_To_Subprogram_Definition (Def)) then
1011 Check_For_Premature_Usage
1012 (Access_To_Subprogram_Definition (Def));
1014 Check_For_Premature_Usage (Subtype_Mark (Def));
1017 -- The only cases left are N_Access_Function_Definition and
1018 -- N_Access_Procedure_Definition.
1021 if Present (Parameter_Specifications (Def)) then
1022 Param := First (Parameter_Specifications (Def));
1023 while Present (Param) loop
1024 Check_For_Premature_Usage (Parameter_Type (Param));
1025 Param := Next (Param);
1029 if Nkind (Def) = N_Access_Function_Definition then
1030 Check_For_Premature_Usage (Result_Definition (Def));
1033 end Check_For_Premature_Usage;
1037 Formals : constant List_Id := Parameter_Specifications (T_Def);
1040 Desig_Type : constant Entity_Id :=
1041 Create_Itype (E_Subprogram_Type, Parent (T_Def));
1043 -- Start of processing for Access_Subprogram_Declaration
1046 Check_SPARK_Restriction ("access type is not allowed", T_Def);
1048 -- Associate the Itype node with the inner full-type declaration or
1049 -- subprogram spec or entry body. This is required to handle nested
1050 -- anonymous declarations. For example:
1053 -- (X : access procedure
1054 -- (Y : access procedure
1057 D_Ityp := Associated_Node_For_Itype (Desig_Type);
1058 while not (Nkind_In (D_Ityp, N_Full_Type_Declaration,
1059 N_Private_Type_Declaration,
1060 N_Private_Extension_Declaration,
1061 N_Procedure_Specification,
1062 N_Function_Specification,
1066 Nkind_In (D_Ityp, N_Object_Declaration,
1067 N_Object_Renaming_Declaration,
1068 N_Formal_Object_Declaration,
1069 N_Formal_Type_Declaration,
1070 N_Task_Type_Declaration,
1071 N_Protected_Type_Declaration))
1073 D_Ityp := Parent (D_Ityp);
1074 pragma Assert (D_Ityp /= Empty);
1077 Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
1079 if Nkind_In (D_Ityp, N_Procedure_Specification,
1080 N_Function_Specification)
1082 Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
1084 elsif Nkind_In (D_Ityp, N_Full_Type_Declaration,
1085 N_Object_Declaration,
1086 N_Object_Renaming_Declaration,
1087 N_Formal_Type_Declaration)
1089 Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
1092 if Nkind (T_Def) = N_Access_Function_Definition then
1093 if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
1095 Acc : constant Node_Id := Result_Definition (T_Def);
1098 if Present (Access_To_Subprogram_Definition (Acc))
1100 Protected_Present (Access_To_Subprogram_Definition (Acc))
1104 Replace_Anonymous_Access_To_Protected_Subprogram
1110 Access_Definition (T_Def, Result_Definition (T_Def)));
1115 Analyze (Result_Definition (T_Def));
1118 Typ : constant Entity_Id := Entity (Result_Definition (T_Def));
1121 -- If a null exclusion is imposed on the result type, then
1122 -- create a null-excluding itype (an access subtype) and use
1123 -- it as the function's Etype.
1125 if Is_Access_Type (Typ)
1126 and then Null_Exclusion_In_Return_Present (T_Def)
1128 Set_Etype (Desig_Type,
1129 Create_Null_Excluding_Itype
1131 Related_Nod => T_Def,
1132 Scope_Id => Current_Scope));
1135 if From_With_Type (Typ) then
1137 -- AI05-151: Incomplete types are allowed in all basic
1138 -- declarations, including access to subprograms.
1140 if Ada_Version >= Ada_2012 then
1145 ("illegal use of incomplete type&",
1146 Result_Definition (T_Def), Typ);
1149 elsif Ekind (Current_Scope) = E_Package
1150 and then In_Private_Part (Current_Scope)
1152 if Ekind (Typ) = E_Incomplete_Type then
1153 Append_Elmt (Desig_Type, Private_Dependents (Typ));
1155 elsif Is_Class_Wide_Type (Typ)
1156 and then Ekind (Etype (Typ)) = E_Incomplete_Type
1159 (Desig_Type, Private_Dependents (Etype (Typ)));
1163 Set_Etype (Desig_Type, Typ);
1168 if not (Is_Type (Etype (Desig_Type))) then
1170 ("expect type in function specification",
1171 Result_Definition (T_Def));
1175 Set_Etype (Desig_Type, Standard_Void_Type);
1178 if Present (Formals) then
1179 Push_Scope (Desig_Type);
1181 -- A bit of a kludge here. These kludges will be removed when Itypes
1182 -- have proper parent pointers to their declarations???
1184 -- Kludge 1) Link defining_identifier of formals. Required by
1185 -- First_Formal to provide its functionality.
1191 F := First (Formals);
1193 -- In ASIS mode, the access_to_subprogram may be analyzed twice,
1194 -- when it is part of an unconstrained type and subtype expansion
1195 -- is disabled. To avoid back-end problems with shared profiles,
1196 -- use previous subprogram type as the designated type, and then
1197 -- remove scope added above.
1200 and then Present (Scope (Defining_Identifier (F)))
1202 Set_Etype (T_Name, T_Name);
1203 Init_Size_Align (T_Name);
1204 Set_Directly_Designated_Type (T_Name,
1205 Scope (Defining_Identifier (F)));
1210 while Present (F) loop
1211 if No (Parent (Defining_Identifier (F))) then
1212 Set_Parent (Defining_Identifier (F), F);
1219 Process_Formals (Formals, Parent (T_Def));
1221 -- Kludge 2) End_Scope requires that the parent pointer be set to
1222 -- something reasonable, but Itypes don't have parent pointers. So
1223 -- we set it and then unset it ???
1225 Set_Parent (Desig_Type, T_Name);
1227 Set_Parent (Desig_Type, Empty);
1230 -- Check for premature usage of the type being defined
1232 Check_For_Premature_Usage (T_Def);
1234 -- The return type and/or any parameter type may be incomplete. Mark the
1235 -- subprogram_type as depending on the incomplete type, so that it can
1236 -- be updated when the full type declaration is seen. This only applies
1237 -- to incomplete types declared in some enclosing scope, not to limited
1238 -- views from other packages.
1239 -- Prior to Ada 2012, access to functions can only have in_parameters.
1241 if Present (Formals) then
1242 Formal := First_Formal (Desig_Type);
1243 while Present (Formal) loop
1244 if Ekind (Formal) /= E_In_Parameter
1245 and then Nkind (T_Def) = N_Access_Function_Definition
1246 and then Ada_Version < Ada_2012
1248 Error_Msg_N ("functions can only have IN parameters", Formal);
1251 if Ekind (Etype (Formal)) = E_Incomplete_Type
1252 and then In_Open_Scopes (Scope (Etype (Formal)))
1254 Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
1255 Set_Has_Delayed_Freeze (Desig_Type);
1258 Next_Formal (Formal);
1262 -- Check whether an indirect call without actuals may be possible. This
1263 -- is used when resolving calls whose result is then indexed.
1265 May_Need_Actuals (Desig_Type);
1267 -- If the return type is incomplete, this is legal as long as the type
1268 -- is declared in the current scope and will be completed in it (rather
1269 -- than being part of limited view).
1271 if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
1272 and then not Has_Delayed_Freeze (Desig_Type)
1273 and then In_Open_Scopes (Scope (Etype (Desig_Type)))
1275 Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
1276 Set_Has_Delayed_Freeze (Desig_Type);
1279 Check_Delayed_Subprogram (Desig_Type);
1281 if Protected_Present (T_Def) then
1282 Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
1283 Set_Convention (Desig_Type, Convention_Protected);
1285 Set_Ekind (T_Name, E_Access_Subprogram_Type);
1288 Set_Can_Use_Internal_Rep (T_Name, not Always_Compatible_Rep_On_Target);
1290 Set_Etype (T_Name, T_Name);
1291 Init_Size_Align (T_Name);
1292 Set_Directly_Designated_Type (T_Name, Desig_Type);
1294 Generate_Reference_To_Formals (T_Name);
1296 -- Ada 2005 (AI-231): Propagate the null-excluding attribute
1298 Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
1300 Check_Restriction (No_Access_Subprograms, T_Def);
1301 end Access_Subprogram_Declaration;
1303 ----------------------------
1304 -- Access_Type_Declaration --
1305 ----------------------------
1307 procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
1308 P : constant Node_Id := Parent (Def);
1309 S : constant Node_Id := Subtype_Indication (Def);
1311 Full_Desig : Entity_Id;
1314 Check_SPARK_Restriction ("access type is not allowed", Def);
1316 -- Check for permissible use of incomplete type
1318 if Nkind (S) /= N_Subtype_Indication then
1321 if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
1322 Set_Directly_Designated_Type (T, Entity (S));
1324 Set_Directly_Designated_Type (T,
1325 Process_Subtype (S, P, T, 'P'));
1329 Set_Directly_Designated_Type (T,
1330 Process_Subtype (S, P, T, 'P'));
1333 if All_Present (Def) or Constant_Present (Def) then
1334 Set_Ekind (T, E_General_Access_Type);
1336 Set_Ekind (T, E_Access_Type);
1339 Full_Desig := Designated_Type (T);
1341 if Base_Type (Full_Desig) = T then
1342 Error_Msg_N ("access type cannot designate itself", S);
1344 -- In Ada 2005, the type may have a limited view through some unit in
1345 -- its own context, allowing the following circularity that cannot be
1348 elsif Is_Class_Wide_Type (Full_Desig)
1349 and then Etype (Full_Desig) = T
1352 ("access type cannot designate its own classwide type", S);
1354 -- Clean up indication of tagged status to prevent cascaded errors
1356 Set_Is_Tagged_Type (T, False);
1361 -- If the type has appeared already in a with_type clause, it is frozen
1362 -- and the pointer size is already set. Else, initialize.
1364 if not From_With_Type (T) then
1365 Init_Size_Align (T);
1368 -- Note that Has_Task is always false, since the access type itself
1369 -- is not a task type. See Einfo for more description on this point.
1370 -- Exactly the same consideration applies to Has_Controlled_Component.
1372 Set_Has_Task (T, False);
1373 Set_Has_Controlled_Component (T, False);
1375 -- Initialize field Finalization_Master explicitly to Empty, to avoid
1376 -- problems where an incomplete view of this entity has been previously
1377 -- established by a limited with and an overlaid version of this field
1378 -- (Stored_Constraint) was initialized for the incomplete view.
1380 -- This reset is performed in most cases except where the access type
1381 -- has been created for the purposes of allocating or deallocating a
1382 -- build-in-place object. Such access types have explicitly set pools
1383 -- and finalization masters.
1385 if No (Associated_Storage_Pool (T)) then
1386 Set_Finalization_Master (T, Empty);
1389 -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
1392 Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
1393 Set_Is_Access_Constant (T, Constant_Present (Def));
1394 end Access_Type_Declaration;
1396 ----------------------------------
1397 -- Add_Interface_Tag_Components --
1398 ----------------------------------
1400 procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is
1401 Loc : constant Source_Ptr := Sloc (N);
1405 procedure Add_Tag (Iface : Entity_Id);
1406 -- Add tag for one of the progenitor interfaces
1412 procedure Add_Tag (Iface : Entity_Id) is
1419 pragma Assert (Is_Tagged_Type (Iface) and then Is_Interface (Iface));
1421 -- This is a reasonable place to propagate predicates
1423 if Has_Predicates (Iface) then
1424 Set_Has_Predicates (Typ);
1428 Make_Component_Definition (Loc,
1429 Aliased_Present => True,
1430 Subtype_Indication =>
1431 New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
1433 Tag := Make_Temporary (Loc, 'V');
1436 Make_Component_Declaration (Loc,
1437 Defining_Identifier => Tag,
1438 Component_Definition => Def);
1440 Analyze_Component_Declaration (Decl);
1442 Set_Analyzed (Decl);
1443 Set_Ekind (Tag, E_Component);
1445 Set_Is_Aliased (Tag);
1446 Set_Related_Type (Tag, Iface);
1447 Init_Component_Location (Tag);
1449 pragma Assert (Is_Frozen (Iface));
1451 Set_DT_Entry_Count (Tag,
1452 DT_Entry_Count (First_Entity (Iface)));
1454 if No (Last_Tag) then
1457 Insert_After (Last_Tag, Decl);
1462 -- If the ancestor has discriminants we need to give special support
1463 -- to store the offset_to_top value of the secondary dispatch tables.
1464 -- For this purpose we add a supplementary component just after the
1465 -- field that contains the tag associated with each secondary DT.
1467 if Typ /= Etype (Typ) and then Has_Discriminants (Etype (Typ)) then
1469 Make_Component_Definition (Loc,
1470 Subtype_Indication =>
1471 New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
1473 Offset := Make_Temporary (Loc, 'V');
1476 Make_Component_Declaration (Loc,
1477 Defining_Identifier => Offset,
1478 Component_Definition => Def);
1480 Analyze_Component_Declaration (Decl);
1482 Set_Analyzed (Decl);
1483 Set_Ekind (Offset, E_Component);
1484 Set_Is_Aliased (Offset);
1485 Set_Related_Type (Offset, Iface);
1486 Init_Component_Location (Offset);
1487 Insert_After (Last_Tag, Decl);
1498 -- Start of processing for Add_Interface_Tag_Components
1501 if not RTE_Available (RE_Interface_Tag) then
1503 ("(Ada 2005) interface types not supported by this run-time!",
1508 if Ekind (Typ) /= E_Record_Type
1509 or else (Is_Concurrent_Record_Type (Typ)
1510 and then Is_Empty_List (Abstract_Interface_List (Typ)))
1511 or else (not Is_Concurrent_Record_Type (Typ)
1512 and then No (Interfaces (Typ))
1513 and then Is_Empty_Elmt_List (Interfaces (Typ)))
1518 -- Find the current last tag
1520 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1521 Ext := Record_Extension_Part (Type_Definition (N));
1523 pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
1524 Ext := Type_Definition (N);
1529 if not (Present (Component_List (Ext))) then
1530 Set_Null_Present (Ext, False);
1532 Set_Component_List (Ext,
1533 Make_Component_List (Loc,
1534 Component_Items => L,
1535 Null_Present => False));
1537 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
1538 L := Component_Items
1540 (Record_Extension_Part
1541 (Type_Definition (N))));
1543 L := Component_Items
1545 (Type_Definition (N)));
1548 -- Find the last tag component
1551 while Present (Comp) loop
1552 if Nkind (Comp) = N_Component_Declaration
1553 and then Is_Tag (Defining_Identifier (Comp))
1562 -- At this point L references the list of components and Last_Tag
1563 -- references the current last tag (if any). Now we add the tag
1564 -- corresponding with all the interfaces that are not implemented
1567 if Present (Interfaces (Typ)) then
1568 Elmt := First_Elmt (Interfaces (Typ));
1569 while Present (Elmt) loop
1570 Add_Tag (Node (Elmt));
1574 end Add_Interface_Tag_Components;
1576 -------------------------------------
1577 -- Add_Internal_Interface_Entities --
1578 -------------------------------------
1580 procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is
1583 Iface_Elmt : Elmt_Id;
1584 Iface_Prim : Entity_Id;
1585 Ifaces_List : Elist_Id;
1586 New_Subp : Entity_Id := Empty;
1588 Restore_Scope : Boolean := False;
1591 pragma Assert (Ada_Version >= Ada_2005
1592 and then Is_Record_Type (Tagged_Type)
1593 and then Is_Tagged_Type (Tagged_Type)
1594 and then Has_Interfaces (Tagged_Type)
1595 and then not Is_Interface (Tagged_Type));
1597 -- Ensure that the internal entities are added to the scope of the type
1599 if Scope (Tagged_Type) /= Current_Scope then
1600 Push_Scope (Scope (Tagged_Type));
1601 Restore_Scope := True;
1604 Collect_Interfaces (Tagged_Type, Ifaces_List);
1606 Iface_Elmt := First_Elmt (Ifaces_List);
1607 while Present (Iface_Elmt) loop
1608 Iface := Node (Iface_Elmt);
1610 -- Originally we excluded here from this processing interfaces that
1611 -- are parents of Tagged_Type because their primitives are located
1612 -- in the primary dispatch table (and hence no auxiliary internal
1613 -- entities are required to handle secondary dispatch tables in such
1614 -- case). However, these auxiliary entities are also required to
1615 -- handle derivations of interfaces in formals of generics (see
1616 -- Derive_Subprograms).
1618 Elmt := First_Elmt (Primitive_Operations (Iface));
1619 while Present (Elmt) loop
1620 Iface_Prim := Node (Elmt);
1622 if not Is_Predefined_Dispatching_Operation (Iface_Prim) then
1624 Find_Primitive_Covering_Interface
1625 (Tagged_Type => Tagged_Type,
1626 Iface_Prim => Iface_Prim);
1628 if No (Prim) and then Serious_Errors_Detected > 0 then
1632 pragma Assert (Present (Prim));
1634 -- Ada 2012 (AI05-0197): If the name of the covering primitive
1635 -- differs from the name of the interface primitive then it is
1636 -- a private primitive inherited from a parent type. In such
1637 -- case, given that Tagged_Type covers the interface, the
1638 -- inherited private primitive becomes visible. For such
1639 -- purpose we add a new entity that renames the inherited
1640 -- private primitive.
1642 if Chars (Prim) /= Chars (Iface_Prim) then
1643 pragma Assert (Has_Suffix (Prim, 'P'));
1645 (New_Subp => New_Subp,
1646 Parent_Subp => Iface_Prim,
1647 Derived_Type => Tagged_Type,
1648 Parent_Type => Iface);
1649 Set_Alias (New_Subp, Prim);
1650 Set_Is_Abstract_Subprogram
1651 (New_Subp, Is_Abstract_Subprogram (Prim));
1655 (New_Subp => New_Subp,
1656 Parent_Subp => Iface_Prim,
1657 Derived_Type => Tagged_Type,
1658 Parent_Type => Iface);
1660 -- Ada 2005 (AI-251): Decorate internal entity Iface_Subp
1661 -- associated with interface types. These entities are
1662 -- only registered in the list of primitives of its
1663 -- corresponding tagged type because they are only used
1664 -- to fill the contents of the secondary dispatch tables.
1665 -- Therefore they are removed from the homonym chains.
1667 Set_Is_Hidden (New_Subp);
1668 Set_Is_Internal (New_Subp);
1669 Set_Alias (New_Subp, Prim);
1670 Set_Is_Abstract_Subprogram
1671 (New_Subp, Is_Abstract_Subprogram (Prim));
1672 Set_Interface_Alias (New_Subp, Iface_Prim);
1674 -- If the returned type is an interface then propagate it to
1675 -- the returned type. Needed by the thunk to generate the code
1676 -- which displaces "this" to reference the corresponding
1677 -- secondary dispatch table in the returned object.
1679 if Is_Interface (Etype (Iface_Prim)) then
1680 Set_Etype (New_Subp, Etype (Iface_Prim));
1683 -- Internal entities associated with interface types are
1684 -- only registered in the list of primitives of the tagged
1685 -- type. They are only used to fill the contents of the
1686 -- secondary dispatch tables. Therefore they are not needed
1687 -- in the homonym chains.
1689 Remove_Homonym (New_Subp);
1691 -- Hidden entities associated with interfaces must have set
1692 -- the Has_Delay_Freeze attribute to ensure that, in case of
1693 -- locally defined tagged types (or compiling with static
1694 -- dispatch tables generation disabled) the corresponding
1695 -- entry of the secondary dispatch table is filled when
1696 -- such an entity is frozen.
1698 Set_Has_Delayed_Freeze (New_Subp);
1705 Next_Elmt (Iface_Elmt);
1708 if Restore_Scope then
1711 end Add_Internal_Interface_Entities;
1713 -----------------------------------
1714 -- Analyze_Component_Declaration --
1715 -----------------------------------
1717 procedure Analyze_Component_Declaration (N : Node_Id) is
1718 Id : constant Entity_Id := Defining_Identifier (N);
1719 E : constant Node_Id := Expression (N);
1720 Typ : constant Node_Id :=
1721 Subtype_Indication (Component_Definition (N));
1725 function Contains_POC (Constr : Node_Id) return Boolean;
1726 -- Determines whether a constraint uses the discriminant of a record
1727 -- type thus becoming a per-object constraint (POC).
1729 function Is_Known_Limited (Typ : Entity_Id) return Boolean;
1730 -- Typ is the type of the current component, check whether this type is
1731 -- a limited type. Used to validate declaration against that of
1732 -- enclosing record.
1738 function Contains_POC (Constr : Node_Id) return Boolean is
1740 -- Prevent cascaded errors
1742 if Error_Posted (Constr) then
1746 case Nkind (Constr) is
1747 when N_Attribute_Reference =>
1749 Attribute_Name (Constr) = Name_Access
1750 and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
1752 when N_Discriminant_Association =>
1753 return Denotes_Discriminant (Expression (Constr));
1755 when N_Identifier =>
1756 return Denotes_Discriminant (Constr);
1758 when N_Index_Or_Discriminant_Constraint =>
1763 IDC := First (Constraints (Constr));
1764 while Present (IDC) loop
1766 -- One per-object constraint is sufficient
1768 if Contains_POC (IDC) then
1779 return Denotes_Discriminant (Low_Bound (Constr))
1781 Denotes_Discriminant (High_Bound (Constr));
1783 when N_Range_Constraint =>
1784 return Denotes_Discriminant (Range_Expression (Constr));
1792 ----------------------
1793 -- Is_Known_Limited --
1794 ----------------------
1796 function Is_Known_Limited (Typ : Entity_Id) return Boolean is
1797 P : constant Entity_Id := Etype (Typ);
1798 R : constant Entity_Id := Root_Type (Typ);
1801 if Is_Limited_Record (Typ) then
1804 -- If the root type is limited (and not a limited interface)
1805 -- so is the current type
1807 elsif Is_Limited_Record (R)
1808 and then (not Is_Interface (R) or else not Is_Limited_Interface (R))
1812 -- Else the type may have a limited interface progenitor, but a
1813 -- limited record parent.
1815 elsif R /= P and then Is_Limited_Record (P) then
1821 end Is_Known_Limited;
1823 -- Start of processing for Analyze_Component_Declaration
1826 Generate_Definition (Id);
1829 if Present (Typ) then
1830 T := Find_Type_Of_Object
1831 (Subtype_Indication (Component_Definition (N)), N);
1833 if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then
1834 Check_SPARK_Restriction ("subtype mark required", Typ);
1837 -- Ada 2005 (AI-230): Access Definition case
1840 pragma Assert (Present
1841 (Access_Definition (Component_Definition (N))));
1843 T := Access_Definition
1845 N => Access_Definition (Component_Definition (N)));
1846 Set_Is_Local_Anonymous_Access (T);
1848 -- Ada 2005 (AI-254)
1850 if Present (Access_To_Subprogram_Definition
1851 (Access_Definition (Component_Definition (N))))
1852 and then Protected_Present (Access_To_Subprogram_Definition
1854 (Component_Definition (N))))
1856 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
1860 -- If the subtype is a constrained subtype of the enclosing record,
1861 -- (which must have a partial view) the back-end does not properly
1862 -- handle the recursion. Rewrite the component declaration with an
1863 -- explicit subtype indication, which is acceptable to Gigi. We can copy
1864 -- the tree directly because side effects have already been removed from
1865 -- discriminant constraints.
1867 if Ekind (T) = E_Access_Subtype
1868 and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
1869 and then Comes_From_Source (T)
1870 and then Nkind (Parent (T)) = N_Subtype_Declaration
1871 and then Etype (Directly_Designated_Type (T)) = Current_Scope
1874 (Subtype_Indication (Component_Definition (N)),
1875 New_Copy_Tree (Subtype_Indication (Parent (T))));
1876 T := Find_Type_Of_Object
1877 (Subtype_Indication (Component_Definition (N)), N);
1880 -- If the component declaration includes a default expression, then we
1881 -- check that the component is not of a limited type (RM 3.7(5)),
1882 -- and do the special preanalysis of the expression (see section on
1883 -- "Handling of Default and Per-Object Expressions" in the spec of
1887 Check_SPARK_Restriction ("default expression is not allowed", E);
1888 Preanalyze_Spec_Expression (E, T);
1889 Check_Initialization (T, E);
1891 if Ada_Version >= Ada_2005
1892 and then Ekind (T) = E_Anonymous_Access_Type
1893 and then Etype (E) /= Any_Type
1895 -- Check RM 3.9.2(9): "if the expected type for an expression is
1896 -- an anonymous access-to-specific tagged type, then the object
1897 -- designated by the expression shall not be dynamically tagged
1898 -- unless it is a controlling operand in a call on a dispatching
1901 if Is_Tagged_Type (Directly_Designated_Type (T))
1903 Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
1905 Ekind (Directly_Designated_Type (Etype (E))) =
1909 ("access to specific tagged type required (RM 3.9.2(9))", E);
1912 -- (Ada 2005: AI-230): Accessibility check for anonymous
1915 if Type_Access_Level (Etype (E)) >
1916 Deepest_Type_Access_Level (T)
1919 ("expression has deeper access level than component " &
1920 "(RM 3.10.2 (12.2))", E);
1923 -- The initialization expression is a reference to an access
1924 -- discriminant. The type of the discriminant is always deeper
1925 -- than any access type.
1927 if Ekind (Etype (E)) = E_Anonymous_Access_Type
1928 and then Is_Entity_Name (E)
1929 and then Ekind (Entity (E)) = E_In_Parameter
1930 and then Present (Discriminal_Link (Entity (E)))
1933 ("discriminant has deeper accessibility level than target",
1939 -- The parent type may be a private view with unknown discriminants,
1940 -- and thus unconstrained. Regular components must be constrained.
1942 if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
1943 if Is_Class_Wide_Type (T) then
1945 ("class-wide subtype with unknown discriminants" &
1946 " in component declaration",
1947 Subtype_Indication (Component_Definition (N)));
1950 ("unconstrained subtype in component declaration",
1951 Subtype_Indication (Component_Definition (N)));
1954 -- Components cannot be abstract, except for the special case of
1955 -- the _Parent field (case of extending an abstract tagged type)
1957 elsif Is_Abstract_Type (T) and then Chars (Id) /= Name_uParent then
1958 Error_Msg_N ("type of a component cannot be abstract", N);
1962 Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
1964 -- The component declaration may have a per-object constraint, set
1965 -- the appropriate flag in the defining identifier of the subtype.
1967 if Present (Subtype_Indication (Component_Definition (N))) then
1969 Sindic : constant Node_Id :=
1970 Subtype_Indication (Component_Definition (N));
1972 if Nkind (Sindic) = N_Subtype_Indication
1973 and then Present (Constraint (Sindic))
1974 and then Contains_POC (Constraint (Sindic))
1976 Set_Has_Per_Object_Constraint (Id);
1981 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
1982 -- out some static checks.
1984 if Ada_Version >= Ada_2005 and then Can_Never_Be_Null (T) then
1985 Null_Exclusion_Static_Checks (N);
1988 -- If this component is private (or depends on a private type), flag the
1989 -- record type to indicate that some operations are not available.
1991 P := Private_Component (T);
1995 -- Check for circular definitions
1997 if P = Any_Type then
1998 Set_Etype (Id, Any_Type);
2000 -- There is a gap in the visibility of operations only if the
2001 -- component type is not defined in the scope of the record type.
2003 elsif Scope (P) = Scope (Current_Scope) then
2006 elsif Is_Limited_Type (P) then
2007 Set_Is_Limited_Composite (Current_Scope);
2010 Set_Is_Private_Composite (Current_Scope);
2015 and then Is_Limited_Type (T)
2016 and then Chars (Id) /= Name_uParent
2017 and then Is_Tagged_Type (Current_Scope)
2019 if Is_Derived_Type (Current_Scope)
2020 and then not Is_Known_Limited (Current_Scope)
2023 ("extension of nonlimited type cannot have limited components",
2026 if Is_Interface (Root_Type (Current_Scope)) then
2028 ("\limitedness is not inherited from limited interface", N);
2029 Error_Msg_N ("\add LIMITED to type indication", N);
2032 Explain_Limited_Type (T, N);
2033 Set_Etype (Id, Any_Type);
2034 Set_Is_Limited_Composite (Current_Scope, False);
2036 elsif not Is_Derived_Type (Current_Scope)
2037 and then not Is_Limited_Record (Current_Scope)
2038 and then not Is_Concurrent_Type (Current_Scope)
2041 ("nonlimited tagged type cannot have limited components", N);
2042 Explain_Limited_Type (T, N);
2043 Set_Etype (Id, Any_Type);
2044 Set_Is_Limited_Composite (Current_Scope, False);
2048 Set_Original_Record_Component (Id, Id);
2050 if Has_Aspects (N) then
2051 Analyze_Aspect_Specifications (N, Id);
2054 Analyze_Dimension (N);
2055 end Analyze_Component_Declaration;
2057 --------------------------
2058 -- Analyze_Declarations --
2059 --------------------------
2061 procedure Analyze_Declarations (L : List_Id) is
2064 procedure Adjust_Decl;
2065 -- Adjust Decl not to include implicit label declarations, since these
2066 -- have strange Sloc values that result in elaboration check problems.
2067 -- (They have the sloc of the label as found in the source, and that
2068 -- is ahead of the current declarative part).
2070 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id);
2071 -- Spec_Id is the entity of a package that may define abstract states.
2072 -- If the states have visible refinement, remove the visibility of each
2073 -- constituent at the end of the package body declarations.
2079 procedure Adjust_Decl is
2081 while Present (Prev (Decl))
2082 and then Nkind (Decl) = N_Implicit_Label_Declaration
2088 --------------------------------
2089 -- Remove_Visible_Refinements --
2090 --------------------------------
2092 procedure Remove_Visible_Refinements (Spec_Id : Entity_Id) is
2093 State_Elmt : Elmt_Id;
2095 if Present (Abstract_States (Spec_Id)) then
2096 State_Elmt := First_Elmt (Abstract_States (Spec_Id));
2097 while Present (State_Elmt) loop
2098 Set_Has_Visible_Refinement (Node (State_Elmt), False);
2099 Next_Elmt (State_Elmt);
2102 end Remove_Visible_Refinements;
2106 Body_Id : Entity_Id;
2108 Freeze_From : Entity_Id := Empty;
2109 Next_Decl : Node_Id;
2111 Spec_Id : Entity_Id;
2113 In_Package_Body : Boolean := False;
2114 -- Flag set when the current declaration list belongs to a package body
2116 -- Start of processing for Analyze_Declarations
2119 if Restriction_Check_Required (SPARK_05) then
2120 Check_Later_Vs_Basic_Declarations (L, During_Parsing => False);
2124 while Present (Decl) loop
2126 -- Package spec cannot contain a package declaration in SPARK
2128 if Nkind (Decl) = N_Package_Declaration
2129 and then Nkind (Parent (L)) = N_Package_Specification
2131 Check_SPARK_Restriction
2132 ("package specification cannot contain a package declaration",
2136 -- Complete analysis of declaration
2139 Next_Decl := Next (Decl);
2141 if No (Freeze_From) then
2142 Freeze_From := First_Entity (Current_Scope);
2145 -- At the end of a declarative part, freeze remaining entities
2146 -- declared in it. The end of the visible declarations of package
2147 -- specification is not the end of a declarative part if private
2148 -- declarations are present. The end of a package declaration is a
2149 -- freezing point only if it a library package. A task definition or
2150 -- protected type definition is not a freeze point either. Finally,
2151 -- we do not freeze entities in generic scopes, because there is no
2152 -- code generated for them and freeze nodes will be generated for
2155 -- The end of a package instantiation is not a freeze point, but
2156 -- for now we make it one, because the generic body is inserted
2157 -- (currently) immediately after. Generic instantiations will not
2158 -- be a freeze point once delayed freezing of bodies is implemented.
2159 -- (This is needed in any case for early instantiations ???).
2161 if No (Next_Decl) then
2162 if Nkind_In (Parent (L), N_Component_List,
2164 N_Protected_Definition)
2168 elsif Nkind (Parent (L)) /= N_Package_Specification then
2169 if Nkind (Parent (L)) = N_Package_Body then
2170 Freeze_From := First_Entity (Current_Scope);
2174 Freeze_All (Freeze_From, Decl);
2175 Freeze_From := Last_Entity (Current_Scope);
2177 elsif Scope (Current_Scope) /= Standard_Standard
2178 and then not Is_Child_Unit (Current_Scope)
2179 and then No (Generic_Parent (Parent (L)))
2183 elsif L /= Visible_Declarations (Parent (L))
2184 or else No (Private_Declarations (Parent (L)))
2185 or else Is_Empty_List (Private_Declarations (Parent (L)))
2188 Freeze_All (Freeze_From, Decl);
2189 Freeze_From := Last_Entity (Current_Scope);
2192 -- If next node is a body then freeze all types before the body.
2193 -- An exception occurs for some expander-generated bodies. If these
2194 -- are generated at places where in general language rules would not
2195 -- allow a freeze point, then we assume that the expander has
2196 -- explicitly checked that all required types are properly frozen,
2197 -- and we do not cause general freezing here. This special circuit
2198 -- is used when the encountered body is marked as having already
2201 -- In all other cases (bodies that come from source, and expander
2202 -- generated bodies that have not been analyzed yet), freeze all
2203 -- types now. Note that in the latter case, the expander must take
2204 -- care to attach the bodies at a proper place in the tree so as to
2205 -- not cause unwanted freezing at that point.
2207 elsif not Analyzed (Next_Decl)
2208 and then (Nkind_In (Next_Decl, N_Subprogram_Body,
2214 Nkind (Next_Decl) in N_Body_Stub)
2217 Freeze_All (Freeze_From, Decl);
2218 Freeze_From := Last_Entity (Current_Scope);
2225 Context := Parent (L);
2227 -- Analyze aspect/pragma Initializes of a package at the end of the
2228 -- visible declarations as the aspect/pragma has visibility over the
2231 if Nkind (Context) = N_Package_Specification
2232 and then L = Visible_Declarations (Context)
2234 Spec_Id := Defining_Entity (Parent (Context));
2235 Prag := Get_Pragma (Spec_Id, Pragma_Initializes);
2237 if Present (Prag) then
2238 Analyze_Initializes_In_Decl_Part (Prag);
2241 -- Analyze the state refinements within a package body now, after
2242 -- all hidden states have been encountered and freely visible.
2243 -- Refinements must be processed before pragmas Refined_Depends and
2244 -- Refined_Global because the last two may mention constituents.
2246 elsif Nkind (Context) = N_Package_Body then
2247 In_Package_Body := True;
2249 Body_Id := Defining_Entity (Context);
2250 Spec_Id := Corresponding_Spec (Context);
2251 Prag := Get_Pragma (Body_Id, Pragma_Refined_State);
2253 -- The analysis of pragma Refined_State detects whether the spec
2254 -- has abstract states available for refinement.
2256 if Present (Prag) then
2257 Analyze_Refined_State_In_Decl_Part (Prag);
2259 -- State refinement is required when the package declaration has
2260 -- abstract states. Null states are not considered.
2262 elsif Present (Abstract_States (Spec_Id))
2263 and then not Has_Null_Abstract_State (Spec_Id)
2266 ("package & requires state refinement", Context, Spec_Id);
2271 -- Analyze the contracts of a subprogram declaration or a body now due
2272 -- to delayed visibility requirements of aspects.
2275 while Present (Decl) loop
2276 if Nkind (Decl) = N_Subprogram_Body then
2277 Analyze_Subprogram_Body_Contract (Defining_Entity (Decl));
2279 elsif Nkind (Decl) = N_Subprogram_Declaration then
2280 Analyze_Subprogram_Contract (Defining_Entity (Decl));
2286 -- State refinements are visible upto the end the of the package body
2287 -- declarations. Hide the refinements from visibility to restore the
2288 -- original state conditions.
2290 if In_Package_Body then
2291 Remove_Visible_Refinements (Spec_Id);
2293 end Analyze_Declarations;
2295 -----------------------------------
2296 -- Analyze_Full_Type_Declaration --
2297 -----------------------------------
2299 procedure Analyze_Full_Type_Declaration (N : Node_Id) is
2300 Def : constant Node_Id := Type_Definition (N);
2301 Def_Id : constant Entity_Id := Defining_Identifier (N);
2305 Is_Remote : constant Boolean :=
2306 (Is_Remote_Types (Current_Scope)
2307 or else Is_Remote_Call_Interface (Current_Scope))
2308 and then not (In_Private_Part (Current_Scope)
2309 or else In_Package_Body (Current_Scope));
2311 procedure Check_Ops_From_Incomplete_Type;
2312 -- If there is a tagged incomplete partial view of the type, traverse
2313 -- the primitives of the incomplete view and change the type of any
2314 -- controlling formals and result to indicate the full view. The
2315 -- primitives will be added to the full type's primitive operations
2316 -- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which
2317 -- is called from Process_Incomplete_Dependents).
2319 ------------------------------------
2320 -- Check_Ops_From_Incomplete_Type --
2321 ------------------------------------
2323 procedure Check_Ops_From_Incomplete_Type is
2330 and then Ekind (Prev) = E_Incomplete_Type
2331 and then Is_Tagged_Type (Prev)
2332 and then Is_Tagged_Type (T)
2334 Elmt := First_Elmt (Primitive_Operations (Prev));
2335 while Present (Elmt) loop
2338 Formal := First_Formal (Op);
2339 while Present (Formal) loop
2340 if Etype (Formal) = Prev then
2341 Set_Etype (Formal, T);
2344 Next_Formal (Formal);
2347 if Etype (Op) = Prev then
2354 end Check_Ops_From_Incomplete_Type;
2356 -- Start of processing for Analyze_Full_Type_Declaration
2359 Prev := Find_Type_Name (N);
2361 -- The full view, if present, now points to the current type
2363 -- Ada 2005 (AI-50217): If the type was previously decorated when
2364 -- imported through a LIMITED WITH clause, it appears as incomplete
2365 -- but has no full view.
2367 if Ekind (Prev) = E_Incomplete_Type
2368 and then Present (Full_View (Prev))
2370 T := Full_View (Prev);
2375 Set_Is_Pure (T, Is_Pure (Current_Scope));
2377 -- We set the flag Is_First_Subtype here. It is needed to set the
2378 -- corresponding flag for the Implicit class-wide-type created
2379 -- during tagged types processing.
2381 Set_Is_First_Subtype (T, True);
2383 -- Only composite types other than array types are allowed to have
2388 -- For derived types, the rule will be checked once we've figured
2389 -- out the parent type.
2391 when N_Derived_Type_Definition =>
2394 -- For record types, discriminants are allowed, unless we are in
2397 when N_Record_Definition =>
2398 if Present (Discriminant_Specifications (N)) then
2399 Check_SPARK_Restriction
2400 ("discriminant type is not allowed",
2402 (First (Discriminant_Specifications (N))));
2406 if Present (Discriminant_Specifications (N)) then
2408 ("elementary or array type cannot have discriminants",
2410 (First (Discriminant_Specifications (N))));
2414 -- Elaborate the type definition according to kind, and generate
2415 -- subsidiary (implicit) subtypes where needed. We skip this if it was
2416 -- already done (this happens during the reanalysis that follows a call
2417 -- to the high level optimizer).
2419 if not Analyzed (T) then
2424 when N_Access_To_Subprogram_Definition =>
2425 Access_Subprogram_Declaration (T, Def);
2427 -- If this is a remote access to subprogram, we must create the
2428 -- equivalent fat pointer type, and related subprograms.
2431 Process_Remote_AST_Declaration (N);
2434 -- Validate categorization rule against access type declaration
2435 -- usually a violation in Pure unit, Shared_Passive unit.
2437 Validate_Access_Type_Declaration (T, N);
2439 when N_Access_To_Object_Definition =>
2440 Access_Type_Declaration (T, Def);
2442 -- Validate categorization rule against access type declaration
2443 -- usually a violation in Pure unit, Shared_Passive unit.
2445 Validate_Access_Type_Declaration (T, N);
2447 -- If we are in a Remote_Call_Interface package and define a
2448 -- RACW, then calling stubs and specific stream attributes
2452 and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
2454 Add_RACW_Features (Def_Id);
2457 -- Set no strict aliasing flag if config pragma seen
2459 if Opt.No_Strict_Aliasing then
2460 Set_No_Strict_Aliasing (Base_Type (Def_Id));
2463 when N_Array_Type_Definition =>
2464 Array_Type_Declaration (T, Def);
2466 when N_Derived_Type_Definition =>
2467 Derived_Type_Declaration (T, N, T /= Def_Id);
2469 when N_Enumeration_Type_Definition =>
2470 Enumeration_Type_Declaration (T, Def);
2472 when N_Floating_Point_Definition =>
2473 Floating_Point_Type_Declaration (T, Def);
2475 when N_Decimal_Fixed_Point_Definition =>
2476 Decimal_Fixed_Point_Type_Declaration (T, Def);
2478 when N_Ordinary_Fixed_Point_Definition =>
2479 Ordinary_Fixed_Point_Type_Declaration (T, Def);
2481 when N_Signed_Integer_Type_Definition =>
2482 Signed_Integer_Type_Declaration (T, Def);
2484 when N_Modular_Type_Definition =>
2485 Modular_Type_Declaration (T, Def);
2487 when N_Record_Definition =>
2488 Record_Type_Declaration (T, N, Prev);
2490 -- If declaration has a parse error, nothing to elaborate.
2496 raise Program_Error;
2501 if Etype (T) = Any_Type then
2505 -- Controlled type is not allowed in SPARK
2507 if Is_Visibly_Controlled (T) then
2508 Check_SPARK_Restriction ("controlled type is not allowed", N);
2511 -- Some common processing for all types
2513 Set_Depends_On_Private (T, Has_Private_Component (T));
2514 Check_Ops_From_Incomplete_Type;
2516 -- Both the declared entity, and its anonymous base type if one
2517 -- was created, need freeze nodes allocated.
2520 B : constant Entity_Id := Base_Type (T);
2523 -- In the case where the base type differs from the first subtype, we
2524 -- pre-allocate a freeze node, and set the proper link to the first
2525 -- subtype. Freeze_Entity will use this preallocated freeze node when
2526 -- it freezes the entity.
2528 -- This does not apply if the base type is a generic type, whose
2529 -- declaration is independent of the current derived definition.
2531 if B /= T and then not Is_Generic_Type (B) then
2532 Ensure_Freeze_Node (B);
2533 Set_First_Subtype_Link (Freeze_Node (B), T);
2536 -- A type that is imported through a limited_with clause cannot
2537 -- generate any code, and thus need not be frozen. However, an access
2538 -- type with an imported designated type needs a finalization list,
2539 -- which may be referenced in some other package that has non-limited
2540 -- visibility on the designated type. Thus we must create the
2541 -- finalization list at the point the access type is frozen, to
2542 -- prevent unsatisfied references at link time.
2544 if not From_With_Type (T) or else Is_Access_Type (T) then
2545 Set_Has_Delayed_Freeze (T);
2549 -- Case where T is the full declaration of some private type which has
2550 -- been swapped in Defining_Identifier (N).
2552 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2553 Process_Full_View (N, T, Def_Id);
2555 -- Record the reference. The form of this is a little strange, since
2556 -- the full declaration has been swapped in. So the first parameter
2557 -- here represents the entity to which a reference is made which is
2558 -- the "real" entity, i.e. the one swapped in, and the second
2559 -- parameter provides the reference location.
2561 -- Also, we want to kill Has_Pragma_Unreferenced temporarily here
2562 -- since we don't want a complaint about the full type being an
2563 -- unwanted reference to the private type
2566 B : constant Boolean := Has_Pragma_Unreferenced (T);
2568 Set_Has_Pragma_Unreferenced (T, False);
2569 Generate_Reference (T, T, 'c');
2570 Set_Has_Pragma_Unreferenced (T, B);
2573 Set_Completion_Referenced (Def_Id);
2575 -- For completion of incomplete type, process incomplete dependents
2576 -- and always mark the full type as referenced (it is the incomplete
2577 -- type that we get for any real reference).
2579 elsif Ekind (Prev) = E_Incomplete_Type then
2580 Process_Incomplete_Dependents (N, T, Prev);
2581 Generate_Reference (Prev, Def_Id, 'c');
2582 Set_Completion_Referenced (Def_Id);
2584 -- If not private type or incomplete type completion, this is a real
2585 -- definition of a new entity, so record it.
2588 Generate_Definition (Def_Id);
2591 if Chars (Scope (Def_Id)) = Name_System
2592 and then Chars (Def_Id) = Name_Address
2593 and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N)))
2595 Set_Is_Descendent_Of_Address (Def_Id);
2596 Set_Is_Descendent_Of_Address (Base_Type (Def_Id));
2597 Set_Is_Descendent_Of_Address (Prev);
2600 Set_Optimize_Alignment_Flags (Def_Id);
2601 Check_Eliminated (Def_Id);
2603 -- If the declaration is a completion and aspects are present, apply
2604 -- them to the entity for the type which is currently the partial
2605 -- view, but which is the one that will be frozen.
2607 if Has_Aspects (N) then
2608 if Prev /= Def_Id then
2609 Analyze_Aspect_Specifications (N, Prev);
2611 Analyze_Aspect_Specifications (N, Def_Id);
2614 end Analyze_Full_Type_Declaration;
2616 ----------------------------------
2617 -- Analyze_Incomplete_Type_Decl --
2618 ----------------------------------
2620 procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
2621 F : constant Boolean := Is_Pure (Current_Scope);
2625 Check_SPARK_Restriction ("incomplete type is not allowed", N);
2627 Generate_Definition (Defining_Identifier (N));
2629 -- Process an incomplete declaration. The identifier must not have been
2630 -- declared already in the scope. However, an incomplete declaration may
2631 -- appear in the private part of a package, for a private type that has
2632 -- already been declared.
2634 -- In this case, the discriminants (if any) must match
2636 T := Find_Type_Name (N);
2638 Set_Ekind (T, E_Incomplete_Type);
2639 Init_Size_Align (T);
2640 Set_Is_First_Subtype (T, True);
2643 -- Ada 2005 (AI-326): Minimum decoration to give support to tagged
2644 -- incomplete types.
2646 if Tagged_Present (N) then
2647 Set_Is_Tagged_Type (T);
2648 Make_Class_Wide_Type (T);
2649 Set_Direct_Primitive_Operations (T, New_Elmt_List);
2654 Set_Stored_Constraint (T, No_Elist);
2656 if Present (Discriminant_Specifications (N)) then
2657 Process_Discriminants (N);
2662 -- If the type has discriminants, non-trivial subtypes may be
2663 -- declared before the full view of the type. The full views of those
2664 -- subtypes will be built after the full view of the type.
2666 Set_Private_Dependents (T, New_Elmt_List);
2668 end Analyze_Incomplete_Type_Decl;
2670 -----------------------------------
2671 -- Analyze_Interface_Declaration --
2672 -----------------------------------
2674 procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
2675 CW : constant Entity_Id := Class_Wide_Type (T);
2678 Set_Is_Tagged_Type (T);
2680 Set_Is_Limited_Record (T, Limited_Present (Def)
2681 or else Task_Present (Def)
2682 or else Protected_Present (Def)
2683 or else Synchronized_Present (Def));
2685 -- Type is abstract if full declaration carries keyword, or if previous
2686 -- partial view did.
2688 Set_Is_Abstract_Type (T);
2689 Set_Is_Interface (T);
2691 -- Type is a limited interface if it includes the keyword limited, task,
2692 -- protected, or synchronized.
2694 Set_Is_Limited_Interface
2695 (T, Limited_Present (Def)
2696 or else Protected_Present (Def)
2697 or else Synchronized_Present (Def)
2698 or else Task_Present (Def));
2700 Set_Interfaces (T, New_Elmt_List);
2701 Set_Direct_Primitive_Operations (T, New_Elmt_List);
2703 -- Complete the decoration of the class-wide entity if it was already
2704 -- built (i.e. during the creation of the limited view)
2706 if Present (CW) then
2707 Set_Is_Interface (CW);
2708 Set_Is_Limited_Interface (CW, Is_Limited_Interface (T));
2711 -- Check runtime support for synchronized interfaces
2713 if VM_Target = No_VM
2714 and then (Is_Task_Interface (T)
2715 or else Is_Protected_Interface (T)
2716 or else Is_Synchronized_Interface (T))
2717 and then not RTE_Available (RE_Select_Specific_Data)
2719 Error_Msg_CRT ("synchronized interfaces", T);
2721 end Analyze_Interface_Declaration;
2723 -----------------------------
2724 -- Analyze_Itype_Reference --
2725 -----------------------------
2727 -- Nothing to do. This node is placed in the tree only for the benefit of
2728 -- back end processing, and has no effect on the semantic processing.
2730 procedure Analyze_Itype_Reference (N : Node_Id) is
2732 pragma Assert (Is_Itype (Itype (N)));
2734 end Analyze_Itype_Reference;
2736 --------------------------------
2737 -- Analyze_Number_Declaration --
2738 --------------------------------
2740 procedure Analyze_Number_Declaration (N : Node_Id) is
2741 Id : constant Entity_Id := Defining_Identifier (N);
2742 E : constant Node_Id := Expression (N);
2744 Index : Interp_Index;
2748 Generate_Definition (Id);
2751 -- This is an optimization of a common case of an integer literal
2753 if Nkind (E) = N_Integer_Literal then
2754 Set_Is_Static_Expression (E, True);
2755 Set_Etype (E, Universal_Integer);
2757 Set_Etype (Id, Universal_Integer);
2758 Set_Ekind (Id, E_Named_Integer);
2759 Set_Is_Frozen (Id, True);
2763 Set_Is_Pure (Id, Is_Pure (Current_Scope));
2765 -- Process expression, replacing error by integer zero, to avoid
2766 -- cascaded errors or aborts further along in the processing
2768 -- Replace Error by integer zero, which seems least likely to cause
2772 Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
2773 Set_Error_Posted (E);
2778 -- Verify that the expression is static and numeric. If
2779 -- the expression is overloaded, we apply the preference
2780 -- rule that favors root numeric types.
2782 if not Is_Overloaded (E) then
2788 Get_First_Interp (E, Index, It);
2789 while Present (It.Typ) loop
2790 if (Is_Integer_Type (It.Typ) or else Is_Real_Type (It.Typ))
2791 and then (Scope (Base_Type (It.Typ))) = Standard_Standard
2793 if T = Any_Type then
2796 elsif It.Typ = Universal_Real
2797 or else It.Typ = Universal_Integer
2799 -- Choose universal interpretation over any other
2806 Get_Next_Interp (Index, It);
2810 if Is_Integer_Type (T) then
2812 Set_Etype (Id, Universal_Integer);
2813 Set_Ekind (Id, E_Named_Integer);
2815 elsif Is_Real_Type (T) then
2817 -- Because the real value is converted to universal_real, this is a
2818 -- legal context for a universal fixed expression.
2820 if T = Universal_Fixed then
2822 Loc : constant Source_Ptr := Sloc (N);
2823 Conv : constant Node_Id := Make_Type_Conversion (Loc,
2825 New_Occurrence_Of (Universal_Real, Loc),
2826 Expression => Relocate_Node (E));
2833 elsif T = Any_Fixed then
2834 Error_Msg_N ("illegal context for mixed mode operation", E);
2836 -- Expression is of the form : universal_fixed * integer. Try to
2837 -- resolve as universal_real.
2839 T := Universal_Real;
2844 Set_Etype (Id, Universal_Real);
2845 Set_Ekind (Id, E_Named_Real);
2848 Wrong_Type (E, Any_Numeric);
2852 Set_Ekind (Id, E_Constant);
2853 Set_Never_Set_In_Source (Id, True);
2854 Set_Is_True_Constant (Id, True);
2858 if Nkind_In (E, N_Integer_Literal, N_Real_Literal) then
2859 Set_Etype (E, Etype (Id));
2862 if not Is_OK_Static_Expression (E) then
2863 Flag_Non_Static_Expr
2864 ("non-static expression used in number declaration!", E);
2865 Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
2866 Set_Etype (E, Any_Type);
2868 end Analyze_Number_Declaration;
2870 --------------------------------
2871 -- Analyze_Object_Declaration --
2872 --------------------------------
2874 procedure Analyze_Object_Declaration (N : Node_Id) is
2875 Loc : constant Source_Ptr := Sloc (N);
2876 Id : constant Entity_Id := Defining_Identifier (N);
2880 E : Node_Id := Expression (N);
2881 -- E is set to Expression (N) throughout this routine. When
2882 -- Expression (N) is modified, E is changed accordingly.
2884 Prev_Entity : Entity_Id := Empty;
2886 function Count_Tasks (T : Entity_Id) return Uint;
2887 -- This function is called when a non-generic library level object of a
2888 -- task type is declared. Its function is to count the static number of
2889 -- tasks declared within the type (it is only called if Has_Tasks is set
2890 -- for T). As a side effect, if an array of tasks with non-static bounds
2891 -- or a variant record type is encountered, Check_Restrictions is called
2892 -- indicating the count is unknown.
2898 function Count_Tasks (T : Entity_Id) return Uint is
2904 if Is_Task_Type (T) then
2907 elsif Is_Record_Type (T) then
2908 if Has_Discriminants (T) then
2909 Check_Restriction (Max_Tasks, N);
2914 C := First_Component (T);
2915 while Present (C) loop
2916 V := V + Count_Tasks (Etype (C));
2923 elsif Is_Array_Type (T) then
2924 X := First_Index (T);
2925 V := Count_Tasks (Component_Type (T));
2926 while Present (X) loop
2929 if not Is_Static_Subtype (C) then
2930 Check_Restriction (Max_Tasks, N);
2933 V := V * (UI_Max (Uint_0,
2934 Expr_Value (Type_High_Bound (C)) -
2935 Expr_Value (Type_Low_Bound (C)) + Uint_1));
2948 -- Start of processing for Analyze_Object_Declaration
2951 -- There are three kinds of implicit types generated by an
2952 -- object declaration:
2954 -- 1. Those generated by the original Object Definition
2956 -- 2. Those generated by the Expression
2958 -- 3. Those used to constrain the Object Definition with the
2959 -- expression constraints when the definition is unconstrained.
2961 -- They must be generated in this order to avoid order of elaboration
2962 -- issues. Thus the first step (after entering the name) is to analyze
2963 -- the object definition.
2965 if Constant_Present (N) then
2966 Prev_Entity := Current_Entity_In_Scope (Id);
2968 if Present (Prev_Entity)
2971 -- If the homograph is an implicit subprogram, it is overridden
2972 -- by the current declaration.
2974 ((Is_Overloadable (Prev_Entity)
2975 and then Is_Inherited_Operation (Prev_Entity))
2977 -- The current object is a discriminal generated for an entry
2978 -- family index. Even though the index is a constant, in this
2979 -- particular context there is no true constant redeclaration.
2980 -- Enter_Name will handle the visibility.
2983 (Is_Discriminal (Id)
2984 and then Ekind (Discriminal_Link (Id)) =
2985 E_Entry_Index_Parameter)
2987 -- The current object is the renaming for a generic declared
2988 -- within the instance.
2991 (Ekind (Prev_Entity) = E_Package
2992 and then Nkind (Parent (Prev_Entity)) =
2993 N_Package_Renaming_Declaration
2994 and then not Comes_From_Source (Prev_Entity)
2995 and then Is_Generic_Instance (Renamed_Entity (Prev_Entity))))
2997 Prev_Entity := Empty;
3001 if Present (Prev_Entity) then
3002 Constant_Redeclaration (Id, N, T);
3004 Generate_Reference (Prev_Entity, Id, 'c');
3005 Set_Completion_Referenced (Id);
3007 if Error_Posted (N) then
3009 -- Type mismatch or illegal redeclaration, Do not analyze
3010 -- expression to avoid cascaded errors.
3012 T := Find_Type_Of_Object (Object_Definition (N), N);
3014 Set_Ekind (Id, E_Variable);
3018 -- In the normal case, enter identifier at the start to catch premature
3019 -- usage in the initialization expression.
3022 Generate_Definition (Id);
3025 Mark_Coextensions (N, Object_Definition (N));
3027 T := Find_Type_Of_Object (Object_Definition (N), N);
3029 if Nkind (Object_Definition (N)) = N_Access_Definition
3031 (Access_To_Subprogram_Definition (Object_Definition (N)))
3032 and then Protected_Present
3033 (Access_To_Subprogram_Definition (Object_Definition (N)))
3035 T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
3038 if Error_Posted (Id) then
3040 Set_Ekind (Id, E_Variable);
3045 -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
3046 -- out some static checks
3048 if Ada_Version >= Ada_2005
3049 and then Can_Never_Be_Null (T)
3051 -- In case of aggregates we must also take care of the correct
3052 -- initialization of nested aggregates bug this is done at the
3053 -- point of the analysis of the aggregate (see sem_aggr.adb)
3055 if Present (Expression (N))
3056 and then Nkind (Expression (N)) = N_Aggregate
3062 Save_Typ : constant Entity_Id := Etype (Id);
3064 Set_Etype (Id, T); -- Temp. decoration for static checks
3065 Null_Exclusion_Static_Checks (N);
3066 Set_Etype (Id, Save_Typ);
3071 -- Object is marked pure if it is in a pure scope
3073 Set_Is_Pure (Id, Is_Pure (Current_Scope));
3075 -- If deferred constant, make sure context is appropriate. We detect
3076 -- a deferred constant as a constant declaration with no expression.
3077 -- A deferred constant can appear in a package body if its completion
3078 -- is by means of an interface pragma.
3080 if Constant_Present (N) and then No (E) then
3082 -- A deferred constant may appear in the declarative part of the
3083 -- following constructs:
3087 -- extended return statements
3090 -- subprogram bodies
3093 -- When declared inside a package spec, a deferred constant must be
3094 -- completed by a full constant declaration or pragma Import. In all
3095 -- other cases, the only proper completion is pragma Import. Extended
3096 -- return statements are flagged as invalid contexts because they do
3097 -- not have a declarative part and so cannot accommodate the pragma.
3099 if Ekind (Current_Scope) = E_Return_Statement then
3101 ("invalid context for deferred constant declaration (RM 7.4)",
3104 ("\declaration requires an initialization expression",
3106 Set_Constant_Present (N, False);
3108 -- In Ada 83, deferred constant must be of private type
3110 elsif not Is_Private_Type (T) then
3111 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3113 ("(Ada 83) deferred constant must be private type", N);
3117 -- If not a deferred constant, then object declaration freezes its type
3120 Check_Fully_Declared (T, N);
3121 Freeze_Before (N, T);
3124 -- If the object was created by a constrained array definition, then
3125 -- set the link in both the anonymous base type and anonymous subtype
3126 -- that are built to represent the array type to point to the object.
3128 if Nkind (Object_Definition (Declaration_Node (Id))) =
3129 N_Constrained_Array_Definition
3131 Set_Related_Array_Object (T, Id);
3132 Set_Related_Array_Object (Base_Type (T), Id);
3135 -- Special checks for protected objects not at library level
3137 if Is_Protected_Type (T)
3138 and then not Is_Library_Level_Entity (Id)
3140 Check_Restriction (No_Local_Protected_Objects, Id);
3142 -- Protected objects with interrupt handlers must be at library level
3144 -- Ada 2005: this test is not needed (and the corresponding clause
3145 -- in the RM is removed) because accessibility checks are sufficient
3146 -- to make handlers not at the library level illegal.
3148 -- AI05-0303: the AI is in fact a binding interpretation, and thus
3149 -- applies to the '95 version of the language as well.
3151 if Has_Interrupt_Handler (T) and then Ada_Version < Ada_95 then
3153 ("interrupt object can only be declared at library level", Id);
3157 -- The actual subtype of the object is the nominal subtype, unless
3158 -- the nominal one is unconstrained and obtained from the expression.
3162 -- These checks should be performed before the initialization expression
3163 -- is considered, so that the Object_Definition node is still the same
3164 -- as in source code.
3166 -- In SPARK, the nominal subtype shall be given by a subtype mark and
3167 -- shall not be unconstrained. (The only exception to this is the
3168 -- admission of declarations of constants of type String.)
3171 Nkind_In (Object_Definition (N), N_Identifier, N_Expanded_Name)
3173 Check_SPARK_Restriction
3174 ("subtype mark required", Object_Definition (N));
3176 elsif Is_Array_Type (T)
3177 and then not Is_Constrained (T)
3178 and then T /= Standard_String
3180 Check_SPARK_Restriction
3181 ("subtype mark of constrained type expected",
3182 Object_Definition (N));
3185 -- There are no aliased objects in SPARK
3187 if Aliased_Present (N) then
3188 Check_SPARK_Restriction ("aliased object is not allowed", N);
3191 -- Process initialization expression if present and not in error
3193 if Present (E) and then E /= Error then
3195 -- Generate an error in case of CPP class-wide object initialization.
3196 -- Required because otherwise the expansion of the class-wide
3197 -- assignment would try to use 'size to initialize the object
3198 -- (primitive that is not available in CPP tagged types).
3200 if Is_Class_Wide_Type (Act_T)
3202 (Is_CPP_Class (Root_Type (Etype (Act_T)))
3204 (Present (Full_View (Root_Type (Etype (Act_T))))
3206 Is_CPP_Class (Full_View (Root_Type (Etype (Act_T))))))
3209 ("predefined assignment not available for 'C'P'P tagged types",
3213 Mark_Coextensions (N, E);
3216 -- In case of errors detected in the analysis of the expression,
3217 -- decorate it with the expected type to avoid cascaded errors
3219 if No (Etype (E)) then
3223 -- If an initialization expression is present, then we set the
3224 -- Is_True_Constant flag. It will be reset if this is a variable
3225 -- and it is indeed modified.
3227 Set_Is_True_Constant (Id, True);
3229 -- If we are analyzing a constant declaration, set its completion
3230 -- flag after analyzing and resolving the expression.
3232 if Constant_Present (N) then
3233 Set_Has_Completion (Id);
3236 -- Set type and resolve (type may be overridden later on). Note:
3237 -- Ekind (Id) must still be E_Void at this point so that incorrect
3238 -- early usage within E is properly diagnosed.
3243 -- No further action needed if E is a call to an inlined function
3244 -- which returns an unconstrained type and it has been expanded into
3245 -- a procedure call. In that case N has been replaced by an object
3246 -- declaration without initializing expression and it has been
3247 -- analyzed (see Expand_Inlined_Call).
3250 and then Expander_Active
3251 and then Nkind (E) = N_Function_Call
3252 and then Nkind (Name (E)) in N_Has_Entity
3253 and then Is_Inlined (Entity (Name (E)))
3254 and then not Is_Constrained (Etype (E))
3255 and then Analyzed (N)
3256 and then No (Expression (N))
3261 -- If E is null and has been replaced by an N_Raise_Constraint_Error
3262 -- node (which was marked already-analyzed), we need to set the type
3263 -- to something other than Any_Access in order to keep gigi happy.
3265 if Etype (E) = Any_Access then
3269 -- If the object is an access to variable, the initialization
3270 -- expression cannot be an access to constant.
3272 if Is_Access_Type (T)
3273 and then not Is_Access_Constant (T)
3274 and then Is_Access_Type (Etype (E))
3275 and then Is_Access_Constant (Etype (E))
3278 ("access to variable cannot be initialized "
3279 & "with an access-to-constant expression", E);
3282 if not Assignment_OK (N) then
3283 Check_Initialization (T, E);
3286 Check_Unset_Reference (E);
3288 -- If this is a variable, then set current value. If this is a
3289 -- declared constant of a scalar type with a static expression,
3290 -- indicate that it is always valid.
3292 if not Constant_Present (N) then
3293 if Compile_Time_Known_Value (E) then
3294 Set_Current_Value (Id, E);
3297 elsif Is_Scalar_Type (T)
3298 and then Is_OK_Static_Expression (E)
3300 Set_Is_Known_Valid (Id);
3303 -- Deal with setting of null flags
3305 if Is_Access_Type (T) then
3306 if Known_Non_Null (E) then
3307 Set_Is_Known_Non_Null (Id, True);
3308 elsif Known_Null (E)
3309 and then not Can_Never_Be_Null (Id)
3311 Set_Is_Known_Null (Id, True);
3315 -- Check incorrect use of dynamically tagged expressions
3317 if Is_Tagged_Type (T) then
3318 Check_Dynamically_Tagged_Expression
3324 Apply_Scalar_Range_Check (E, T);
3325 Apply_Static_Length_Check (E, T);
3327 if Nkind (Original_Node (N)) = N_Object_Declaration
3328 and then Comes_From_Source (Original_Node (N))
3330 -- Only call test if needed
3332 and then Restriction_Check_Required (SPARK_05)
3333 and then not Is_SPARK_Initialization_Expr (Original_Node (E))
3335 Check_SPARK_Restriction
3336 ("initialization expression is not appropriate", E);
3340 -- If the No_Streams restriction is set, check that the type of the
3341 -- object is not, and does not contain, any subtype derived from
3342 -- Ada.Streams.Root_Stream_Type. Note that we guard the call to
3343 -- Has_Stream just for efficiency reasons. There is no point in
3344 -- spending time on a Has_Stream check if the restriction is not set.
3346 if Restriction_Check_Required (No_Streams) then
3347 if Has_Stream (T) then
3348 Check_Restriction (No_Streams, N);
3352 -- Deal with predicate check before we start to do major rewriting. It
3353 -- is OK to initialize and then check the initialized value, since the
3354 -- object goes out of scope if we get a predicate failure. Note that we
3355 -- do this in the analyzer and not the expander because the analyzer
3356 -- does some substantial rewriting in some cases.
3358 -- We need a predicate check if the type has predicates, and if either
3359 -- there is an initializing expression, or for default initialization
3360 -- when we have at least one case of an explicit default initial value.
3362 if not Suppress_Assignment_Checks (N)
3363 and then Present (Predicate_Function (T))
3367 Is_Partially_Initialized_Type (T, Include_Implicit => False))
3369 -- If the type has a static predicate and the expression is known at
3370 -- compile time, see if the expression satisfies the predicate.
3373 Check_Expression_Against_Static_Predicate (E, T);
3377 Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc)));
3380 -- Case of unconstrained type
3382 if Is_Indefinite_Subtype (T) then
3384 -- In SPARK, a declaration of unconstrained type is allowed
3385 -- only for constants of type string.
3387 if Is_String_Type (T) and then not Constant_Present (N) then
3388 Check_SPARK_Restriction
3389 ("declaration of object of unconstrained type not allowed", N);
3392 -- Nothing to do in deferred constant case
3394 if Constant_Present (N) and then No (E) then
3397 -- Case of no initialization present
3400 if No_Initialization (N) then
3403 elsif Is_Class_Wide_Type (T) then
3405 ("initialization required in class-wide declaration ", N);
3409 ("unconstrained subtype not allowed (need initialization)",
3410 Object_Definition (N));
3412 if Is_Record_Type (T) and then Has_Discriminants (T) then
3414 ("\provide initial value or explicit discriminant values",
3415 Object_Definition (N));
3418 ("\or give default discriminant values for type&",
3419 Object_Definition (N), T);
3421 elsif Is_Array_Type (T) then
3423 ("\provide initial value or explicit array bounds",
3424 Object_Definition (N));
3428 -- Case of initialization present but in error. Set initial
3429 -- expression as absent (but do not make above complaints)
3431 elsif E = Error then
3432 Set_Expression (N, Empty);
3435 -- Case of initialization present
3438 -- Check restrictions in Ada 83
3440 if not Constant_Present (N) then
3442 -- Unconstrained variables not allowed in Ada 83 mode
3444 if Ada_Version = Ada_83
3445 and then Comes_From_Source (Object_Definition (N))
3448 ("(Ada 83) unconstrained variable not allowed",
3449 Object_Definition (N));
3453 -- Now we constrain the variable from the initializing expression
3455 -- If the expression is an aggregate, it has been expanded into
3456 -- individual assignments. Retrieve the actual type from the
3457 -- expanded construct.
3459 if Is_Array_Type (T)
3460 and then No_Initialization (N)
3461 and then Nkind (Original_Node (E)) = N_Aggregate
3465 -- In case of class-wide interface object declarations we delay
3466 -- the generation of the equivalent record type declarations until
3467 -- its expansion because there are cases in they are not required.
3469 elsif Is_Interface (T) then
3473 Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
3474 Act_T := Find_Type_Of_Object (Object_Definition (N), N);
3477 Set_Is_Constr_Subt_For_U_Nominal (Act_T);
3479 if Aliased_Present (N) then
3480 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
3483 Freeze_Before (N, Act_T);
3484 Freeze_Before (N, T);
3487 elsif Is_Array_Type (T)
3488 and then No_Initialization (N)
3489 and then Nkind (Original_Node (E)) = N_Aggregate
3491 if not Is_Entity_Name (Object_Definition (N)) then
3493 Check_Compile_Time_Size (Act_T);
3495 if Aliased_Present (N) then
3496 Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
3500 -- When the given object definition and the aggregate are specified
3501 -- independently, and their lengths might differ do a length check.
3502 -- This cannot happen if the aggregate is of the form (others =>...)
3504 if not Is_Constrained (T) then
3507 elsif Nkind (E) = N_Raise_Constraint_Error then
3509 -- Aggregate is statically illegal. Place back in declaration
3511 Set_Expression (N, E);
3512 Set_No_Initialization (N, False);
3514 elsif T = Etype (E) then
3517 elsif Nkind (E) = N_Aggregate
3518 and then Present (Component_Associations (E))
3519 and then Present (Choices (First (Component_Associations (E))))
3520 and then Nkind (First
3521 (Choices (First (Component_Associations (E))))) = N_Others_Choice
3526 Apply_Length_Check (E, T);
3529 -- If the type is limited unconstrained with defaulted discriminants and
3530 -- there is no expression, then the object is constrained by the
3531 -- defaults, so it is worthwhile building the corresponding subtype.
3533 elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T))
3534 and then not Is_Constrained (T)
3535 and then Has_Discriminants (T)
3538 Act_T := Build_Default_Subtype (T, N);
3540 -- Ada 2005: a limited object may be initialized by means of an
3541 -- aggregate. If the type has default discriminants it has an
3542 -- unconstrained nominal type, Its actual subtype will be obtained
3543 -- from the aggregate, and not from the default discriminants.
3548 Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
3550 elsif Present (Underlying_Type (T))
3551 and then not Is_Constrained (Underlying_Type (T))
3552 and then Has_Discriminants (Underlying_Type (T))
3553 and then Nkind (E) = N_Function_Call
3554 and then Constant_Present (N)
3556 -- The back-end has problems with constants of a discriminated type
3557 -- with defaults, if the initial value is a function call. We
3558 -- generate an intermediate temporary for the result of the call.
3559 -- It is unclear why this should make it acceptable to gcc. ???
3561 Remove_Side_Effects (E);
3563 -- If this is a constant declaration of an unconstrained type and
3564 -- the initialization is an aggregate, we can use the subtype of the
3565 -- aggregate for the declared entity because it is immutable.
3567 elsif not Is_Constrained (T)
3568 and then Has_Discriminants (T)
3569 and then Constant_Present (N)
3570 and then not Has_Unchecked_Union (T)
3571 and then Nkind (E) = N_Aggregate
3576 -- Check No_Wide_Characters restriction
3578 Check_Wide_Character_Restriction (T, Object_Definition (N));
3580 -- Indicate this is not set in source. Certainly true for constants, and
3581 -- true for variables so far (will be reset for a variable if and when
3582 -- we encounter a modification in the source).
3584 Set_Never_Set_In_Source (Id, True);
3586 -- Now establish the proper kind and type of the object
3588 if Constant_Present (N) then
3589 Set_Ekind (Id, E_Constant);
3590 Set_Is_True_Constant (Id);
3593 Set_Ekind (Id, E_Variable);
3595 -- A variable is set as shared passive if it appears in a shared
3596 -- passive package, and is at the outer level. This is not done for
3597 -- entities generated during expansion, because those are always
3598 -- manipulated locally.
3600 if Is_Shared_Passive (Current_Scope)
3601 and then Is_Library_Level_Entity (Id)
3602 and then Comes_From_Source (Id)
3604 Set_Is_Shared_Passive (Id);
3605 Check_Shared_Var (Id, T, N);
3608 -- Set Has_Initial_Value if initializing expression present. Note
3609 -- that if there is no initializing expression, we leave the state
3610 -- of this flag unchanged (usually it will be False, but notably in
3611 -- the case of exception choice variables, it will already be true).
3614 Set_Has_Initial_Value (Id, True);
3618 -- Initialize alignment and size and capture alignment setting
3620 Init_Alignment (Id);
3622 Set_Optimize_Alignment_Flags (Id);
3624 -- Deal with aliased case
3626 if Aliased_Present (N) then
3627 Set_Is_Aliased (Id);
3629 -- If the object is aliased and the type is unconstrained with
3630 -- defaulted discriminants and there is no expression, then the
3631 -- object is constrained by the defaults, so it is worthwhile
3632 -- building the corresponding subtype.
3634 -- Ada 2005 (AI-363): If the aliased object is discriminated and
3635 -- unconstrained, then only establish an actual subtype if the
3636 -- nominal subtype is indefinite. In definite cases the object is
3637 -- unconstrained in Ada 2005.
3640 and then Is_Record_Type (T)
3641 and then not Is_Constrained (T)
3642 and then Has_Discriminants (T)
3643 and then (Ada_Version < Ada_2005 or else Is_Indefinite_Subtype (T))
3645 Set_Actual_Subtype (Id, Build_Default_Subtype (T, N));
3649 -- Now we can set the type of the object
3651 Set_Etype (Id, Act_T);
3653 -- Object is marked to be treated as volatile if type is volatile and
3654 -- we clear the Current_Value setting that may have been set above.
3656 if Treat_As_Volatile (Etype (Id)) then
3657 Set_Treat_As_Volatile (Id);
3658 Set_Current_Value (Id, Empty);
3661 -- Deal with controlled types
3663 if Has_Controlled_Component (Etype (Id))
3664 or else Is_Controlled (Etype (Id))
3666 if not Is_Library_Level_Entity (Id) then
3667 Check_Restriction (No_Nested_Finalization, N);
3669 Validate_Controlled_Object (Id);
3673 if Has_Task (Etype (Id)) then
3674 Check_Restriction (No_Tasking, N);
3676 -- Deal with counting max tasks
3678 -- Nothing to do if inside a generic
3680 if Inside_A_Generic then
3683 -- If library level entity, then count tasks
3685 elsif Is_Library_Level_Entity (Id) then
3686 Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
3688 -- If not library level entity, then indicate we don't know max
3689 -- tasks and also check task hierarchy restriction and blocking
3690 -- operation (since starting a task is definitely blocking!)
3693 Check_Restriction (Max_Tasks, N);
3694 Check_Restriction (No_Task_Hierarchy, N);
3695 Check_Potentially_Blocking_Operation (N);
3698 -- A rather specialized test. If we see two tasks being declared
3699 -- of the same type in the same object declaration, and the task
3700 -- has an entry with an address clause, we know that program error
3701 -- will be raised at run time since we can't have two tasks with
3702 -- entries at the same address.
3704 if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
3709 E := First_Entity (Etype (Id));
3710 while Present (E) loop
3711 if Ekind (E) = E_Entry
3712 and then Present (Get_Attribute_Definition_Clause
3713 (E, Attribute_Address))
3716 ("??more than one task with same entry address", N);
3718 ("\??Program_Error will be raised at run time", N);
3720 Make_Raise_Program_Error (Loc,
3721 Reason => PE_Duplicated_Entry_Address));
3731 -- Some simple constant-propagation: if the expression is a constant
3732 -- string initialized with a literal, share the literal. This avoids
3736 and then Is_Entity_Name (E)
3737 and then Ekind (Entity (E)) = E_Constant
3738 and then Base_Type (Etype (E)) = Standard_String
3741 Val : constant Node_Id := Constant_Value (Entity (E));
3744 and then Nkind (Val) = N_String_Literal
3746 Rewrite (E, New_Copy (Val));
3751 -- Another optimization: if the nominal subtype is unconstrained and
3752 -- the expression is a function call that returns an unconstrained
3753 -- type, rewrite the declaration as a renaming of the result of the
3754 -- call. The exceptions below are cases where the copy is expected,
3755 -- either by the back end (Aliased case) or by the semantics, as for
3756 -- initializing controlled types or copying tags for classwide types.
3759 and then Nkind (E) = N_Explicit_Dereference
3760 and then Nkind (Original_Node (E)) = N_Function_Call
3761 and then not Is_Library_Level_Entity (Id)
3762 and then not Is_Constrained (Underlying_Type (T))
3763 and then not Is_Aliased (Id)
3764 and then not Is_Class_Wide_Type (T)
3765 and then not Is_Controlled (T)
3766 and then not Has_Controlled_Component (Base_Type (T))
3767 and then Expander_Active
3770 Make_Object_Renaming_Declaration (Loc,
3771 Defining_Identifier => Id,
3772 Access_Definition => Empty,
3773 Subtype_Mark => New_Occurrence_Of
3774 (Base_Type (Etype (Id)), Loc),
3777 Set_Renamed_Object (Id, E);
3779 -- Force generation of debugging information for the constant and for
3780 -- the renamed function call.
3782 Set_Debug_Info_Needed (Id);
3783 Set_Debug_Info_Needed (Entity (Prefix (E)));
3786 if Present (Prev_Entity)
3787 and then Is_Frozen (Prev_Entity)
3788 and then not Error_Posted (Id)
3790 Error_Msg_N ("full constant declaration appears too late", N);
3793 Check_Eliminated (Id);
3795 -- Deal with setting In_Private_Part flag if in private part
3797 if Ekind (Scope (Id)) = E_Package
3798 and then In_Private_Part (Scope (Id))
3800 Set_In_Private_Part (Id);
3803 -- Check for violation of No_Local_Timing_Events
3805 if Restriction_Check_Required (No_Local_Timing_Events)
3806 and then not Is_Library_Level_Entity (Id)
3807 and then Is_RTE (Etype (Id), RE_Timing_Event)
3809 Check_Restriction (No_Local_Timing_Events, N);
3813 -- Initialize the refined state of a variable here because this is a
3814 -- common destination for legal and illegal object declarations.
3816 if Ekind (Id) = E_Variable then
3817 Set_Refined_State (Id, Empty);
3820 if Has_Aspects (N) then
3821 Analyze_Aspect_Specifications (N, Id);
3824 Analyze_Dimension (N);
3826 -- Verify whether the object declaration introduces an illegal hidden
3827 -- state within a package subject to a null abstract state.
3829 if Formal_Extensions and then Ekind (Id) = E_Variable then
3830 Check_No_Hidden_State (Id);
3832 end Analyze_Object_Declaration;
3834 ---------------------------
3835 -- Analyze_Others_Choice --
3836 ---------------------------
3838 -- Nothing to do for the others choice node itself, the semantic analysis
3839 -- of the others choice will occur as part of the processing of the parent
3841 procedure Analyze_Others_Choice (N : Node_Id) is
3842 pragma Warnings (Off, N);
3845 end Analyze_Others_Choice;
3847 -------------------------------------------
3848 -- Analyze_Private_Extension_Declaration --
3849 -------------------------------------------
3851 procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
3852 T : constant Entity_Id := Defining_Identifier (N);
3853 Indic : constant Node_Id := Subtype_Indication (N);
3854 Parent_Type : Entity_Id;
3855 Parent_Base : Entity_Id;
3858 -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
3860 if Is_Non_Empty_List (Interface_List (N)) then
3866 Intf := First (Interface_List (N));
3867 while Present (Intf) loop
3868 T := Find_Type_Of_Subtype_Indic (Intf);
3870 Diagnose_Interface (Intf, T);
3876 Generate_Definition (T);
3878 -- For other than Ada 2012, just enter the name in the current scope
3880 if Ada_Version < Ada_2012 then
3883 -- Ada 2012 (AI05-0162): Enter the name in the current scope handling
3884 -- case of private type that completes an incomplete type.
3891 Prev := Find_Type_Name (N);
3893 pragma Assert (Prev = T
3894 or else (Ekind (Prev) = E_Incomplete_Type
3895 and then Present (Full_View (Prev))
3896 and then Full_View (Prev) = T));
3900 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
3901 Parent_Base := Base_Type (Parent_Type);
3903 if Parent_Type = Any_Type
3904 or else Etype (Parent_Type) = Any_Type
3906 Set_Ekind (T, Ekind (Parent_Type));
3907 Set_Etype (T, Any_Type);
3910 elsif not Is_Tagged_Type (Parent_Type) then
3912 ("parent of type extension must be a tagged type ", Indic);
3915 elsif Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
3916 Error_Msg_N ("premature derivation of incomplete type", Indic);
3919 elsif Is_Concurrent_Type (Parent_Type) then
3921 ("parent type of a private extension cannot be "
3922 & "a synchronized tagged type (RM 3.9.1 (3/1))", N);
3924 Set_Etype (T, Any_Type);
3925 Set_Ekind (T, E_Limited_Private_Type);
3926 Set_Private_Dependents (T, New_Elmt_List);
3927 Set_Error_Posted (T);
3931 -- Perhaps the parent type should be changed to the class-wide type's
3932 -- specific type in this case to prevent cascading errors ???
3934 if Is_Class_Wide_Type (Parent_Type) then
3936 ("parent of type extension must not be a class-wide type", Indic);
3940 if (not Is_Package_Or_Generic_Package (Current_Scope)
3941 and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
3942 or else In_Private_Part (Current_Scope)
3945 Error_Msg_N ("invalid context for private extension", N);
3948 -- Set common attributes
3950 Set_Is_Pure (T, Is_Pure (Current_Scope));
3951 Set_Scope (T, Current_Scope);
3952 Set_Ekind (T, E_Record_Type_With_Private);
3953 Init_Size_Align (T);
3955 Set_Etype (T, Parent_Base);
3956 Set_Has_Task (T, Has_Task (Parent_Base));
3958 Set_Convention (T, Convention (Parent_Type));
3959 Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
3960 Set_Is_First_Subtype (T);
3961 Make_Class_Wide_Type (T);
3963 if Unknown_Discriminants_Present (N) then
3964 Set_Discriminant_Constraint (T, No_Elist);
3967 Build_Derived_Record_Type (N, Parent_Type, T);
3969 -- Propagate inherited invariant information. The new type has
3970 -- invariants, if the parent type has inheritable invariants,
3971 -- and these invariants can in turn be inherited.
3973 if Has_Inheritable_Invariants (Parent_Type) then
3974 Set_Has_Inheritable_Invariants (T);
3975 Set_Has_Invariants (T);
3978 -- Ada 2005 (AI-443): Synchronized private extension or a rewritten
3979 -- synchronized formal derived type.
3981 if Ada_Version >= Ada_2005
3982 and then Synchronized_Present (N)
3984 Set_Is_Limited_Record (T);
3986 -- Formal derived type case
3988 if Is_Generic_Type (T) then
3990 -- The parent must be a tagged limited type or a synchronized
3993 if (not Is_Tagged_Type (Parent_Type)
3994 or else not Is_Limited_Type (Parent_Type))
3996 (not Is_Interface (Parent_Type)
3997 or else not Is_Synchronized_Interface (Parent_Type))
3999 Error_Msg_NE ("parent type of & must be tagged limited " &
4000 "or synchronized", N, T);
4003 -- The progenitors (if any) must be limited or synchronized
4006 if Present (Interfaces (T)) then
4009 Iface_Elmt : Elmt_Id;
4012 Iface_Elmt := First_Elmt (Interfaces (T));
4013 while Present (Iface_Elmt) loop
4014 Iface := Node (Iface_Elmt);
4016 if not Is_Limited_Interface (Iface)
4017 and then not Is_Synchronized_Interface (Iface)
4019 Error_Msg_NE ("progenitor & must be limited " &
4020 "or synchronized", N, Iface);
4023 Next_Elmt (Iface_Elmt);
4028 -- Regular derived extension, the parent must be a limited or
4029 -- synchronized interface.
4032 if not Is_Interface (Parent_Type)
4033 or else (not Is_Limited_Interface (Parent_Type)
4035 not Is_Synchronized_Interface (Parent_Type))
4038 ("parent type of & must be limited interface", N, T);
4042 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
4043 -- extension with a synchronized parent must be explicitly declared
4044 -- synchronized, because the full view will be a synchronized type.
4045 -- This must be checked before the check for limited types below,
4046 -- to ensure that types declared limited are not allowed to extend
4047 -- synchronized interfaces.
4049 elsif Is_Interface (Parent_Type)
4050 and then Is_Synchronized_Interface (Parent_Type)
4051 and then not Synchronized_Present (N)
4054 ("private extension of& must be explicitly synchronized",
4057 elsif Limited_Present (N) then
4058 Set_Is_Limited_Record (T);
4060 if not Is_Limited_Type (Parent_Type)
4062 (not Is_Interface (Parent_Type)
4063 or else not Is_Limited_Interface (Parent_Type))
4065 Error_Msg_NE ("parent type& of limited extension must be limited",
4071 if Has_Aspects (N) then
4072 Analyze_Aspect_Specifications (N, T);
4074 end Analyze_Private_Extension_Declaration;
4076 ---------------------------------
4077 -- Analyze_Subtype_Declaration --
4078 ---------------------------------
4080 procedure Analyze_Subtype_Declaration
4082 Skip : Boolean := False)
4084 Id : constant Entity_Id := Defining_Identifier (N);
4086 R_Checks : Check_Result;
4089 Generate_Definition (Id);
4090 Set_Is_Pure (Id, Is_Pure (Current_Scope));
4091 Init_Size_Align (Id);
4093 -- The following guard condition on Enter_Name is to handle cases where
4094 -- the defining identifier has already been entered into the scope but
4095 -- the declaration as a whole needs to be analyzed.
4097 -- This case in particular happens for derived enumeration types. The
4098 -- derived enumeration type is processed as an inserted enumeration type
4099 -- declaration followed by a rewritten subtype declaration. The defining
4100 -- identifier, however, is entered into the name scope very early in the
4101 -- processing of the original type declaration and therefore needs to be
4102 -- avoided here, when the created subtype declaration is analyzed. (See
4103 -- Build_Derived_Types)
4105 -- This also happens when the full view of a private type is derived
4106 -- type with constraints. In this case the entity has been introduced
4107 -- in the private declaration.
4109 -- Finally this happens in some complex cases when validity checks are
4110 -- enabled, where the same subtype declaration may be analyzed twice.
4111 -- This can happen if the subtype is created by the pre-analysis of
4112 -- an attribute tht gives the range of a loop statement, and the loop
4113 -- itself appears within an if_statement that will be rewritten during
4117 or else (Present (Etype (Id))
4118 and then (Is_Private_Type (Etype (Id))
4119 or else Is_Task_Type (Etype (Id))
4120 or else Is_Rewrite_Substitution (N)))
4124 elsif Current_Entity (Id) = Id then
4131 T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
4133 -- Class-wide equivalent types of records with unknown discriminants
4134 -- involve the generation of an itype which serves as the private view
4135 -- of a constrained record subtype. In such cases the base type of the
4136 -- current subtype we are processing is the private itype. Use the full
4137 -- of the private itype when decorating various attributes.
4140 and then Is_Private_Type (T)
4141 and then Present (Full_View (T))
4146 -- Inherit common attributes
4148 Set_Is_Volatile (Id, Is_Volatile (T));
4149 Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
4150 Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
4151 Set_Convention (Id, Convention (T));
4153 -- If ancestor has predicates then so does the subtype, and in addition
4154 -- we must delay the freeze to properly arrange predicate inheritance.
4156 -- The Ancestor_Type test is a big kludge, there seem to be cases in
4157 -- which T = ID, so the above tests and assignments do nothing???
4159 if Has_Predicates (T)
4160 or else (Present (Ancestor_Subtype (T))
4161 and then Has_Predicates (Ancestor_Subtype (T)))
4163 Set_Has_Predicates (Id);
4164 Set_Has_Delayed_Freeze (Id);
4167 -- Subtype of Boolean cannot have a constraint in SPARK
4169 if Is_Boolean_Type (T)
4170 and then Nkind (Subtype_Indication (N)) = N_Subtype_Indication
4172 Check_SPARK_Restriction
4173 ("subtype of Boolean cannot have constraint", N);
4176 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
4178 Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
4184 if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint then
4185 One_Cstr := First (Constraints (Cstr));
4186 while Present (One_Cstr) loop
4188 -- Index or discriminant constraint in SPARK must be a
4192 Nkind_In (One_Cstr, N_Identifier, N_Expanded_Name)
4194 Check_SPARK_Restriction
4195 ("subtype mark required", One_Cstr);
4197 -- String subtype must have a lower bound of 1 in SPARK.
4198 -- Note that we do not need to test for the non-static case
4199 -- here, since that was already taken care of in
4200 -- Process_Range_Expr_In_Decl.
4202 elsif Base_Type (T) = Standard_String then
4203 Get_Index_Bounds (One_Cstr, Low, High);
4205 if Is_OK_Static_Expression (Low)
4206 and then Expr_Value (Low) /= 1
4208 Check_SPARK_Restriction
4209 ("String subtype must have lower bound of 1", N);
4219 -- In the case where there is no constraint given in the subtype
4220 -- indication, Process_Subtype just returns the Subtype_Mark, so its
4221 -- semantic attributes must be established here.
4223 if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
4224 Set_Etype (Id, Base_Type (T));
4226 -- Subtype of unconstrained array without constraint is not allowed
4229 if Is_Array_Type (T)
4230 and then not Is_Constrained (T)
4232 Check_SPARK_Restriction
4233 ("subtype of unconstrained array must have constraint", N);
4238 Set_Ekind (Id, E_Array_Subtype);
4239 Copy_Array_Subtype_Attributes (Id, T);
4241 when Decimal_Fixed_Point_Kind =>
4242 Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
4243 Set_Digits_Value (Id, Digits_Value (T));
4244 Set_Delta_Value (Id, Delta_Value (T));
4245 Set_Scale_Value (Id, Scale_Value (T));
4246 Set_Small_Value (Id, Small_Value (T));
4247 Set_Scalar_Range (Id, Scalar_Range (T));
4248 Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
4249 Set_Is_Constrained (Id, Is_Constrained (T));
4250 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4251 Set_RM_Size (Id, RM_Size (T));
4253 when Enumeration_Kind =>
4254 Set_Ekind (Id, E_Enumeration_Subtype);
4255 Set_First_Literal (Id, First_Literal (Base_Type (T)));
4256 Set_Scalar_Range (Id, Scalar_Range (T));
4257 Set_Is_Character_Type (Id, Is_Character_Type (T));
4258 Set_Is_Constrained (Id, Is_Constrained (T));
4259 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4260 Set_RM_Size (Id, RM_Size (T));
4262 when Ordinary_Fixed_Point_Kind =>
4263 Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
4264 Set_Scalar_Range (Id, Scalar_Range (T));
4265 Set_Small_Value (Id, Small_Value (T));
4266 Set_Delta_Value (Id, Delta_Value (T));
4267 Set_Is_Constrained (Id, Is_Constrained (T));
4268 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4269 Set_RM_Size (Id, RM_Size (T));
4272 Set_Ekind (Id, E_Floating_Point_Subtype);
4273 Set_Scalar_Range (Id, Scalar_Range (T));
4274 Set_Digits_Value (Id, Digits_Value (T));
4275 Set_Is_Constrained (Id, Is_Constrained (T));
4277 when Signed_Integer_Kind =>
4278 Set_Ekind (Id, E_Signed_Integer_Subtype);
4279 Set_Scalar_Range (Id, Scalar_Range (T));
4280 Set_Is_Constrained (Id, Is_Constrained (T));
4281 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4282 Set_RM_Size (Id, RM_Size (T));
4284 when Modular_Integer_Kind =>
4285 Set_Ekind (Id, E_Modular_Integer_Subtype);
4286 Set_Scalar_Range (Id, Scalar_Range (T));
4287 Set_Is_Constrained (Id, Is_Constrained (T));
4288 Set_Is_Known_Valid (Id, Is_Known_Valid (T));
4289 Set_RM_Size (Id, RM_Size (T));
4291 when Class_Wide_Kind =>
4292 Set_Ekind (Id, E_Class_Wide_Subtype);
4293 Set_First_Entity (Id, First_Entity (T));
4294 Set_Last_Entity (Id, Last_Entity (T));
4295 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4296 Set_Cloned_Subtype (Id, T);
4297 Set_Is_Tagged_Type (Id, True);
4298 Set_Has_Unknown_Discriminants
4301 if Ekind (T) = E_Class_Wide_Subtype then
4302 Set_Equivalent_Type (Id, Equivalent_Type (T));
4305 when E_Record_Type | E_Record_Subtype =>
4306 Set_Ekind (Id, E_Record_Subtype);
4308 if Ekind (T) = E_Record_Subtype
4309 and then Present (Cloned_Subtype (T))
4311 Set_Cloned_Subtype (Id, Cloned_Subtype (T));
4313 Set_Cloned_Subtype (Id, T);
4316 Set_First_Entity (Id, First_Entity (T));
4317 Set_Last_Entity (Id, Last_Entity (T));
4318 Set_Has_Discriminants (Id, Has_Discriminants (T));
4319 Set_Is_Constrained (Id, Is_Constrained (T));
4320 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
4321 Set_Has_Implicit_Dereference
4322 (Id, Has_Implicit_Dereference (T));
4323 Set_Has_Unknown_Discriminants
4324 (Id, Has_Unknown_Discriminants (T));
4326 if Has_Discriminants (T) then
4327 Set_Discriminant_Constraint
4328 (Id, Discriminant_Constraint (T));
4329 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4331 elsif Has_Unknown_Discriminants (Id) then
4332 Set_Discriminant_Constraint (Id, No_Elist);
4335 if Is_Tagged_Type (T) then
4336 Set_Is_Tagged_Type (Id);
4337 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
4338 Set_Direct_Primitive_Operations
4339 (Id, Direct_Primitive_Operations (T));
4340 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4342 if Is_Interface (T) then
4343 Set_Is_Interface (Id);
4344 Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
4348 when Private_Kind =>
4349 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
4350 Set_Has_Discriminants (Id, Has_Discriminants (T));
4351 Set_Is_Constrained (Id, Is_Constrained (T));
4352 Set_First_Entity (Id, First_Entity (T));
4353 Set_Last_Entity (Id, Last_Entity (T));
4354 Set_Private_Dependents (Id, New_Elmt_List);
4355 Set_Is_Limited_Record (Id, Is_Limited_Record (T));
4356 Set_Has_Implicit_Dereference
4357 (Id, Has_Implicit_Dereference (T));
4358 Set_Has_Unknown_Discriminants
4359 (Id, Has_Unknown_Discriminants (T));
4360 Set_Known_To_Have_Preelab_Init
4361 (Id, Known_To_Have_Preelab_Init (T));
4363 if Is_Tagged_Type (T) then
4364 Set_Is_Tagged_Type (Id);
4365 Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
4366 Set_Class_Wide_Type (Id, Class_Wide_Type (T));
4367 Set_Direct_Primitive_Operations (Id,
4368 Direct_Primitive_Operations (T));
4371 -- In general the attributes of the subtype of a private type
4372 -- are the attributes of the partial view of parent. However,
4373 -- the full view may be a discriminated type, and the subtype
4374 -- must share the discriminant constraint to generate correct
4375 -- calls to initialization procedures.
4377 if Has_Discriminants (T) then
4378 Set_Discriminant_Constraint
4379 (Id, Discriminant_Constraint (T));
4380 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4382 elsif Present (Full_View (T))
4383 and then Has_Discriminants (Full_View (T))
4385 Set_Discriminant_Constraint
4386 (Id, Discriminant_Constraint (Full_View (T)));
4387 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4389 -- This would seem semantically correct, but apparently
4390 -- generates spurious errors about missing components ???
4392 -- Set_Has_Discriminants (Id);
4395 Prepare_Private_Subtype_Completion (Id, N);
4397 -- If this is the subtype of a constrained private type with
4398 -- discriminants that has got a full view and we also have
4399 -- built a completion just above, show that the completion
4400 -- is a clone of the full view to the back-end.
4402 if Has_Discriminants (T)
4403 and then not Has_Unknown_Discriminants (T)
4404 and then not Is_Empty_Elmt_List (Discriminant_Constraint (T))
4405 and then Present (Full_View (T))
4406 and then Present (Full_View (Id))
4408 Set_Cloned_Subtype (Full_View (Id), Full_View (T));
4412 Set_Ekind (Id, E_Access_Subtype);
4413 Set_Is_Constrained (Id, Is_Constrained (T));
4414 Set_Is_Access_Constant
4415 (Id, Is_Access_Constant (T));
4416 Set_Directly_Designated_Type
4417 (Id, Designated_Type (T));
4418 Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
4420 -- A Pure library_item must not contain the declaration of a
4421 -- named access type, except within a subprogram, generic
4422 -- subprogram, task unit, or protected unit, or if it has
4423 -- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)).
4425 if Comes_From_Source (Id)
4426 and then In_Pure_Unit
4427 and then not In_Subprogram_Task_Protected_Unit
4428 and then not No_Pool_Assigned (Id)
4431 ("named access types not allowed in pure unit", N);
4434 when Concurrent_Kind =>
4435 Set_Ekind (Id, Subtype_Kind (Ekind (T)));
4436 Set_Corresponding_Record_Type (Id,
4437 Corresponding_Record_Type (T));
4438 Set_First_Entity (Id, First_Entity (T));
4439 Set_First_Private_Entity (Id, First_Private_Entity (T));
4440 Set_Has_Discriminants (Id, Has_Discriminants (T));
4441 Set_Is_Constrained (Id, Is_Constrained (T));
4442 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
4443 Set_Last_Entity (Id, Last_Entity (T));
4445 if Has_Discriminants (T) then
4446 Set_Discriminant_Constraint (Id,
4447 Discriminant_Constraint (T));
4448 Set_Stored_Constraint_From_Discriminant_Constraint (Id);
4451 when E_Incomplete_Type =>
4452 if Ada_Version >= Ada_2005 then
4454 -- In Ada 2005 an incomplete type can be explicitly tagged:
4455 -- propagate indication.
4457 Set_Ekind (Id, E_Incomplete_Subtype);
4458 Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
4459 Set_Private_Dependents (Id, New_Elmt_List);
4461 -- Ada 2005 (AI-412): Decorate an incomplete subtype of an
4462 -- incomplete type visible through a limited with clause.
4464 if From_With_Type (T)
4465 and then Present (Non_Limited_View (T))
4467 Set_From_With_Type (Id);
4468 Set_Non_Limited_View (Id, Non_Limited_View (T));
4470 -- Ada 2005 (AI-412): Add the regular incomplete subtype
4471 -- to the private dependents of the original incomplete
4472 -- type for future transformation.
4475 Append_Elmt (Id, Private_Dependents (T));
4478 -- If the subtype name denotes an incomplete type an error
4479 -- was already reported by Process_Subtype.
4482 Set_Etype (Id, Any_Type);
4486 raise Program_Error;
4490 if Etype (Id) = Any_Type then
4494 -- Some common processing on all types
4496 Set_Size_Info (Id, T);
4497 Set_First_Rep_Item (Id, First_Rep_Item (T));
4499 -- If the parent type is a generic actual, so is the subtype. This may
4500 -- happen in a nested instance. Why Comes_From_Source test???
4502 if not Comes_From_Source (N) then
4503 Set_Is_Generic_Actual_Type (Id, Is_Generic_Actual_Type (T));
4508 Set_Is_Immediately_Visible (Id, True);
4509 Set_Depends_On_Private (Id, Has_Private_Component (T));
4510 Set_Is_Descendent_Of_Address (Id, Is_Descendent_Of_Address (T));
4512 if Is_Interface (T) then
4513 Set_Is_Interface (Id);
4516 if Present (Generic_Parent_Type (N))
4519 (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
4521 (Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
4522 /= N_Formal_Private_Type_Definition)
4524 if Is_Tagged_Type (Id) then
4526 -- If this is a generic actual subtype for a synchronized type,
4527 -- the primitive operations are those of the corresponding record
4528 -- for which there is a separate subtype declaration.
4530 if Is_Concurrent_Type (Id) then
4532 elsif Is_Class_Wide_Type (Id) then
4533 Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
4535 Derive_Subprograms (Generic_Parent_Type (N), Id, T);
4538 elsif Scope (Etype (Id)) /= Standard_Standard then
4539 Derive_Subprograms (Generic_Parent_Type (N), Id);
4543 if Is_Private_Type (T)
4544 and then Present (Full_View (T))
4546 Conditional_Delay (Id, Full_View (T));
4548 -- The subtypes of components or subcomponents of protected types
4549 -- do not need freeze nodes, which would otherwise appear in the
4550 -- wrong scope (before the freeze node for the protected type). The
4551 -- proper subtypes are those of the subcomponents of the corresponding
4554 elsif Ekind (Scope (Id)) /= E_Protected_Type
4555 and then Present (Scope (Scope (Id))) -- error defense!
4556 and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
4558 Conditional_Delay (Id, T);
4561 -- Check that Constraint_Error is raised for a scalar subtype indication
4562 -- when the lower or upper bound of a non-null range lies outside the
4563 -- range of the type mark.
4565 if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
4566 if Is_Scalar_Type (Etype (Id))
4567 and then Scalar_Range (Id) /=
4568 Scalar_Range (Etype (Subtype_Mark
4569 (Subtype_Indication (N))))
4573 Etype (Subtype_Mark (Subtype_Indication (N))));
4575 -- In the array case, check compatibility for each index
4577 elsif Is_Array_Type (Etype (Id))
4578 and then Present (First_Index (Id))
4580 -- This really should be a subprogram that finds the indications
4584 Subt_Index : Node_Id := First_Index (Id);
4585 Target_Index : Node_Id :=
4587 (Subtype_Mark (Subtype_Indication (N))));
4588 Has_Dyn_Chk : Boolean := Has_Dynamic_Range_Check (N);
4591 while Present (Subt_Index) loop
4592 if ((Nkind (Subt_Index) = N_Identifier
4593 and then Ekind (Entity (Subt_Index)) in Scalar_Kind)
4594 or else Nkind (Subt_Index) = N_Subtype_Indication)
4596 Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range
4599 Target_Typ : constant Entity_Id :=
4600 Etype (Target_Index);
4604 (Scalar_Range (Etype (Subt_Index)),
4607 Defining_Identifier (N));
4609 -- Reset Has_Dynamic_Range_Check on the subtype to
4610 -- prevent elision of the index check due to a dynamic
4611 -- check generated for a preceding index (needed since
4612 -- Insert_Range_Checks tries to avoid generating
4613 -- redundant checks on a given declaration).
4615 Set_Has_Dynamic_Range_Check (N, False);
4621 Sloc (Defining_Identifier (N)));
4623 -- Record whether this index involved a dynamic check
4626 Has_Dyn_Chk or else Has_Dynamic_Range_Check (N);
4630 Next_Index (Subt_Index);
4631 Next_Index (Target_Index);
4634 -- Finally, mark whether the subtype involves dynamic checks
4636 Set_Has_Dynamic_Range_Check (N, Has_Dyn_Chk);
4641 -- Make sure that generic actual types are properly frozen. The subtype
4642 -- is marked as a generic actual type when the enclosing instance is
4643 -- analyzed, so here we identify the subtype from the tree structure.
4646 and then Is_Generic_Actual_Type (Id)
4647 and then In_Instance
4648 and then not Comes_From_Source (N)
4649 and then Nkind (Subtype_Indication (N)) /= N_Subtype_Indication
4650 and then Is_Frozen (T)
4652 Freeze_Before (N, Id);
4655 Set_Optimize_Alignment_Flags (Id);
4656 Check_Eliminated (Id);
4659 if Has_Aspects (N) then
4660 Analyze_Aspect_Specifications (N, Id);
4663 Analyze_Dimension (N);
4664 end Analyze_Subtype_Declaration;
4666 --------------------------------
4667 -- Analyze_Subtype_Indication --
4668 --------------------------------
4670 procedure Analyze_Subtype_Indication (N : Node_Id) is
4671 T : constant Entity_Id := Subtype_Mark (N);
4672 R : constant Node_Id := Range_Expression (Constraint (N));
4679 Set_Etype (N, Etype (R));
4680 Resolve (R, Entity (T));
4682 Set_Error_Posted (R);
4683 Set_Error_Posted (T);
4685 end Analyze_Subtype_Indication;
4687 --------------------------
4688 -- Analyze_Variant_Part --
4689 --------------------------
4691 procedure Analyze_Variant_Part (N : Node_Id) is
4692 Discr_Name : Node_Id;
4693 Discr_Type : Entity_Id;
4695 procedure Process_Variant (A : Node_Id);
4696 -- Analyze declarations for a single variant
4698 package Analyze_Variant_Choices is
4699 new Generic_Analyze_Choices (Process_Variant);
4700 use Analyze_Variant_Choices;
4702 ---------------------
4703 -- Process_Variant --
4704 ---------------------
4706 procedure Process_Variant (A : Node_Id) is
4707 CL : constant Node_Id := Component_List (A);
4709 if not Null_Present (CL) then
4710 Analyze_Declarations (Component_Items (CL));
4712 if Present (Variant_Part (CL)) then
4713 Analyze (Variant_Part (CL));
4716 end Process_Variant;
4718 -- Start of processing for Analyze_Variant_Part
4721 Discr_Name := Name (N);
4722 Analyze (Discr_Name);
4724 -- If Discr_Name bad, get out (prevent cascaded errors)
4726 if Etype (Discr_Name) = Any_Type then
4730 -- Check invalid discriminant in variant part
4732 if Ekind (Entity (Discr_Name)) /= E_Discriminant then
4733 Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
4736 Discr_Type := Etype (Entity (Discr_Name));
4738 if not Is_Discrete_Type (Discr_Type) then
4740 ("discriminant in a variant part must be of a discrete type",
4745 -- Now analyze the choices, which also analyzes the declarations that
4746 -- are associated with each choice.
4748 Analyze_Choices (Variants (N), Discr_Type);
4750 -- Note: we used to instantiate and call Check_Choices here to check
4751 -- that the choices covered the discriminant, but it's too early to do
4752 -- that because of statically predicated subtypes, whose analysis may
4753 -- be deferred to their freeze point which may be as late as the freeze
4754 -- point of the containing record. So this call is now to be found in
4755 -- Freeze_Record_Declaration.
4757 end Analyze_Variant_Part;
4759 ----------------------------
4760 -- Array_Type_Declaration --
4761 ----------------------------
4763 procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
4764 Component_Def : constant Node_Id := Component_Definition (Def);
4765 Component_Typ : constant Node_Id := Subtype_Indication (Component_Def);
4766 Element_Type : Entity_Id;
4767 Implicit_Base : Entity_Id;
4769 Related_Id : Entity_Id := Empty;
4771 P : constant Node_Id := Parent (Def);
4775 if Nkind (Def) = N_Constrained_Array_Definition then
4776 Index := First (Discrete_Subtype_Definitions (Def));
4778 Index := First (Subtype_Marks (Def));
4781 -- Find proper names for the implicit types which may be public. In case
4782 -- of anonymous arrays we use the name of the first object of that type
4786 Related_Id := Defining_Identifier (P);
4792 while Present (Index) loop
4795 if not Nkind_In (Index, N_Identifier, N_Expanded_Name) then
4796 Check_SPARK_Restriction ("subtype mark required", Index);
4799 -- Add a subtype declaration for each index of private array type
4800 -- declaration whose etype is also private. For example:
4803 -- type Index is private;
4805 -- type Table is array (Index) of ...
4808 -- This is currently required by the expander for the internally
4809 -- generated equality subprogram of records with variant parts in
4810 -- which the etype of some component is such private type.
4812 if Ekind (Current_Scope) = E_Package
4813 and then In_Private_Part (Current_Scope)
4814 and then Has_Private_Declaration (Etype (Index))
4817 Loc : constant Source_Ptr := Sloc (Def);
4822 New_E := Make_Temporary (Loc, 'T');
4823 Set_Is_Internal (New_E);
4826 Make_Subtype_Declaration (Loc,
4827 Defining_Identifier => New_E,
4828 Subtype_Indication =>
4829 New_Occurrence_Of (Etype (Index), Loc));
4831 Insert_Before (Parent (Def), Decl);
4833 Set_Etype (Index, New_E);
4835 -- If the index is a range the Entity attribute is not
4836 -- available. Example:
4839 -- type T is private;
4841 -- type T is new Natural;
4842 -- Table : array (T(1) .. T(10)) of Boolean;
4845 if Nkind (Index) /= N_Range then
4846 Set_Entity (Index, New_E);
4851 Make_Index (Index, P, Related_Id, Nb_Index);
4853 -- Check error of subtype with predicate for index type
4855 Bad_Predicated_Subtype_Use
4856 ("subtype& has predicate, not allowed as index subtype",
4857 Index, Etype (Index));
4859 -- Move to next index
4862 Nb_Index := Nb_Index + 1;
4865 -- Process subtype indication if one is present
4867 if Present (Component_Typ) then
4868 Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C');
4870 Set_Etype (Component_Typ, Element_Type);
4872 if not Nkind_In (Component_Typ, N_Identifier, N_Expanded_Name) then
4873 Check_SPARK_Restriction ("subtype mark required", Component_Typ);
4876 -- Ada 2005 (AI-230): Access Definition case
4878 else pragma Assert (Present (Access_Definition (Component_Def)));
4880 -- Indicate that the anonymous access type is created by the
4881 -- array type declaration.
4883 Element_Type := Access_Definition
4885 N => Access_Definition (Component_Def));
4886 Set_Is_Local_Anonymous_Access (Element_Type);
4888 -- Propagate the parent. This field is needed if we have to generate
4889 -- the master_id associated with an anonymous access to task type
4890 -- component (see Expand_N_Full_Type_Declaration.Build_Master)
4892 Set_Parent (Element_Type, Parent (T));
4894 -- Ada 2005 (AI-230): In case of components that are anonymous access
4895 -- types the level of accessibility depends on the enclosing type
4898 Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
4900 -- Ada 2005 (AI-254)
4903 CD : constant Node_Id :=
4904 Access_To_Subprogram_Definition
4905 (Access_Definition (Component_Def));
4907 if Present (CD) and then Protected_Present (CD) then
4909 Replace_Anonymous_Access_To_Protected_Subprogram (Def);
4914 -- Constrained array case
4917 T := Create_Itype (E_Void, P, Related_Id, 'T');
4920 if Nkind (Def) = N_Constrained_Array_Definition then
4922 -- Establish Implicit_Base as unconstrained base type
4924 Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
4926 Set_Etype (Implicit_Base, Implicit_Base);
4927 Set_Scope (Implicit_Base, Current_Scope);
4928 Set_Has_Delayed_Freeze (Implicit_Base);
4930 -- The constrained array type is a subtype of the unconstrained one
4932 Set_Ekind (T, E_Array_Subtype);
4933 Init_Size_Align (T);
4934 Set_Etype (T, Implicit_Base);
4935 Set_Scope (T, Current_Scope);
4936 Set_Is_Constrained (T, True);
4937 Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
4938 Set_Has_Delayed_Freeze (T);
4940 -- Complete setup of implicit base type
4942 Set_First_Index (Implicit_Base, First_Index (T));
4943 Set_Component_Type (Implicit_Base, Element_Type);
4944 Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
4945 Set_Component_Size (Implicit_Base, Uint_0);
4946 Set_Packed_Array_Type (Implicit_Base, Empty);
4947 Set_Has_Controlled_Component
4948 (Implicit_Base, Has_Controlled_Component
4950 or else Is_Controlled
4952 Set_Finalize_Storage_Only
4953 (Implicit_Base, Finalize_Storage_Only
4956 -- Unconstrained array case
4959 Set_Ekind (T, E_Array_Type);
4960 Init_Size_Align (T);
4962 Set_Scope (T, Current_Scope);
4963 Set_Component_Size (T, Uint_0);
4964 Set_Is_Constrained (T, False);
4965 Set_First_Index (T, First (Subtype_Marks (Def)));
4966 Set_Has_Delayed_Freeze (T, True);
4967 Set_Has_Task (T, Has_Task (Element_Type));
4968 Set_Has_Controlled_Component (T, Has_Controlled_Component
4971 Is_Controlled (Element_Type));
4972 Set_Finalize_Storage_Only (T, Finalize_Storage_Only
4976 -- Common attributes for both cases
4978 Set_Component_Type (Base_Type (T), Element_Type);
4979 Set_Packed_Array_Type (T, Empty);
4981 if Aliased_Present (Component_Definition (Def)) then
4982 Check_SPARK_Restriction
4983 ("aliased is not allowed", Component_Definition (Def));
4984 Set_Has_Aliased_Components (Etype (T));
4987 -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
4988 -- array type to ensure that objects of this type are initialized.
4990 if Ada_Version >= Ada_2005
4991 and then Can_Never_Be_Null (Element_Type)
4993 Set_Can_Never_Be_Null (T);
4995 if Null_Exclusion_Present (Component_Definition (Def))
4997 -- No need to check itypes because in their case this check was
4998 -- done at their point of creation
5000 and then not Is_Itype (Element_Type)
5003 ("`NOT NULL` not allowed (null already excluded)",
5004 Subtype_Indication (Component_Definition (Def)));
5008 Priv := Private_Component (Element_Type);
5010 if Present (Priv) then
5012 -- Check for circular definitions
5014 if Priv = Any_Type then
5015 Set_Component_Type (Etype (T), Any_Type);
5017 -- There is a gap in the visibility of operations on the composite
5018 -- type only if the component type is defined in a different scope.
5020 elsif Scope (Priv) = Current_Scope then
5023 elsif Is_Limited_Type (Priv) then
5024 Set_Is_Limited_Composite (Etype (T));
5025 Set_Is_Limited_Composite (T);
5027 Set_Is_Private_Composite (Etype (T));
5028 Set_Is_Private_Composite (T);
5032 -- A syntax error in the declaration itself may lead to an empty index
5033 -- list, in which case do a minimal patch.
5035 if No (First_Index (T)) then
5036 Error_Msg_N ("missing index definition in array type declaration", T);
5039 Indexes : constant List_Id :=
5040 New_List (New_Occurrence_Of (Any_Id, Sloc (T)));
5042 Set_Discrete_Subtype_Definitions (Def, Indexes);
5043 Set_First_Index (T, First (Indexes));
5048 -- Create a concatenation operator for the new type. Internal array
5049 -- types created for packed entities do not need such, they are
5050 -- compatible with the user-defined type.
5052 if Number_Dimensions (T) = 1
5053 and then not Is_Packed_Array_Type (T)
5055 New_Concatenation_Op (T);
5058 -- In the case of an unconstrained array the parser has already verified
5059 -- that all the indexes are unconstrained but we still need to make sure
5060 -- that the element type is constrained.
5062 if Is_Indefinite_Subtype (Element_Type) then
5064 ("unconstrained element type in array declaration",
5065 Subtype_Indication (Component_Def));
5067 elsif Is_Abstract_Type (Element_Type) then
5069 ("the type of a component cannot be abstract",
5070 Subtype_Indication (Component_Def));
5073 -- There may be an invariant declared for the component type, but
5074 -- the construction of the component invariant checking procedure
5075 -- takes place during expansion.
5076 end Array_Type_Declaration;
5078 ------------------------------------------------------
5079 -- Replace_Anonymous_Access_To_Protected_Subprogram --
5080 ------------------------------------------------------
5082 function Replace_Anonymous_Access_To_Protected_Subprogram
5083 (N : Node_Id) return Entity_Id
5085 Loc : constant Source_Ptr := Sloc (N);
5087 Curr_Scope : constant Scope_Stack_Entry :=
5088 Scope_Stack.Table (Scope_Stack.Last);
5090 Anon : constant Entity_Id := Make_Temporary (Loc, 'S');
5093 -- Access definition in declaration
5096 -- Object definition or formal definition with an access definition
5099 -- Declaration of anonymous access to subprogram type
5102 -- Original specification in access to subprogram
5107 Set_Is_Internal (Anon);
5110 when N_Component_Declaration |
5111 N_Unconstrained_Array_Definition |
5112 N_Constrained_Array_Definition =>
5113 Comp := Component_Definition (N);
5114 Acc := Access_Definition (Comp);
5116 when N_Discriminant_Specification =>
5117 Comp := Discriminant_Type (N);
5120 when N_Parameter_Specification =>
5121 Comp := Parameter_Type (N);
5124 when N_Access_Function_Definition =>
5125 Comp := Result_Definition (N);
5128 when N_Object_Declaration =>
5129 Comp := Object_Definition (N);
5132 when N_Function_Specification =>
5133 Comp := Result_Definition (N);
5137 raise Program_Error;
5140 Spec := Access_To_Subprogram_Definition (Acc);
5143 Make_Full_Type_Declaration (Loc,
5144 Defining_Identifier => Anon,
5145 Type_Definition => Copy_Separate_Tree (Spec));
5147 Mark_Rewrite_Insertion (Decl);
5149 -- In ASIS mode, analyze the profile on the original node, because
5150 -- the separate copy does not provide enough links to recover the
5151 -- original tree. Analysis is limited to type annotations, within
5152 -- a temporary scope that serves as an anonymous subprogram to collect
5153 -- otherwise useless temporaries and itypes.
5157 Typ : constant Entity_Id := Make_Temporary (Loc, 'S');
5160 if Nkind (Spec) = N_Access_Function_Definition then
5161 Set_Ekind (Typ, E_Function);
5163 Set_Ekind (Typ, E_Procedure);
5166 Set_Parent (Typ, N);
5167 Set_Scope (Typ, Current_Scope);
5170 Process_Formals (Parameter_Specifications (Spec), Spec);
5172 if Nkind (Spec) = N_Access_Function_Definition then
5174 Def : constant Node_Id := Result_Definition (Spec);
5177 -- The result might itself be an anonymous access type, so
5180 if Nkind (Def) = N_Access_Definition then
5181 if Present (Access_To_Subprogram_Definition (Def)) then
5184 Replace_Anonymous_Access_To_Protected_Subprogram
5187 Find_Type (Subtype_Mark (Def));
5200 -- Insert the new declaration in the nearest enclosing scope. If the
5201 -- node is a body and N is its return type, the declaration belongs in
5202 -- the enclosing scope.
5206 if Nkind (P) = N_Subprogram_Body
5207 and then Nkind (N) = N_Function_Specification
5212 while Present (P) and then not Has_Declarations (P) loop
5216 pragma Assert (Present (P));
5218 if Nkind (P) = N_Package_Specification then
5219 Prepend (Decl, Visible_Declarations (P));
5221 Prepend (Decl, Declarations (P));
5224 -- Replace the anonymous type with an occurrence of the new declaration.
5225 -- In all cases the rewritten node does not have the null-exclusion
5226 -- attribute because (if present) it was already inherited by the
5227 -- anonymous entity (Anon). Thus, in case of components we do not
5228 -- inherit this attribute.
5230 if Nkind (N) = N_Parameter_Specification then
5231 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5232 Set_Etype (Defining_Identifier (N), Anon);
5233 Set_Null_Exclusion_Present (N, False);
5235 elsif Nkind (N) = N_Object_Declaration then
5236 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5237 Set_Etype (Defining_Identifier (N), Anon);
5239 elsif Nkind (N) = N_Access_Function_Definition then
5240 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5242 elsif Nkind (N) = N_Function_Specification then
5243 Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
5244 Set_Etype (Defining_Unit_Name (N), Anon);
5248 Make_Component_Definition (Loc,
5249 Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
5252 Mark_Rewrite_Insertion (Comp);
5254 if Nkind_In (N, N_Object_Declaration, N_Access_Function_Definition) then
5258 -- Temporarily remove the current scope (record or subprogram) from
5259 -- the stack to add the new declarations to the enclosing scope.
5261 Scope_Stack.Decrement_Last;
5263 Set_Is_Itype (Anon);
5264 Scope_Stack.Append (Curr_Scope);
5267 Set_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type);
5268 Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target);
5270 end Replace_Anonymous_Access_To_Protected_Subprogram;
5272 -------------------------------
5273 -- Build_Derived_Access_Type --
5274 -------------------------------
5276 procedure Build_Derived_Access_Type
5278 Parent_Type : Entity_Id;
5279 Derived_Type : Entity_Id)
5281 S : constant Node_Id := Subtype_Indication (Type_Definition (N));
5283 Desig_Type : Entity_Id;
5285 Discr_Con_Elist : Elist_Id;
5286 Discr_Con_El : Elmt_Id;
5290 -- Set the designated type so it is available in case this is an access
5291 -- to a self-referential type, e.g. a standard list type with a next
5292 -- pointer. Will be reset after subtype is built.
5294 Set_Directly_Designated_Type
5295 (Derived_Type, Designated_Type (Parent_Type));
5297 Subt := Process_Subtype (S, N);
5299 if Nkind (S) /= N_Subtype_Indication
5300 and then Subt /= Base_Type (Subt)
5302 Set_Ekind (Derived_Type, E_Access_Subtype);
5305 if Ekind (Derived_Type) = E_Access_Subtype then
5307 Pbase : constant Entity_Id := Base_Type (Parent_Type);
5308 Ibase : constant Entity_Id :=
5309 Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
5310 Svg_Chars : constant Name_Id := Chars (Ibase);
5311 Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
5314 Copy_Node (Pbase, Ibase);
5316 Set_Chars (Ibase, Svg_Chars);
5317 Set_Next_Entity (Ibase, Svg_Next_E);
5318 Set_Sloc (Ibase, Sloc (Derived_Type));
5319 Set_Scope (Ibase, Scope (Derived_Type));
5320 Set_Freeze_Node (Ibase, Empty);
5321 Set_Is_Frozen (Ibase, False);
5322 Set_Comes_From_Source (Ibase, False);
5323 Set_Is_First_Subtype (Ibase, False);
5325 Set_Etype (Ibase, Pbase);
5326 Set_Etype (Derived_Type, Ibase);
5330 Set_Directly_Designated_Type
5331 (Derived_Type, Designated_Type (Subt));
5333 Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
5334 Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
5335 Set_Size_Info (Derived_Type, Parent_Type);
5336 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
5337 Set_Depends_On_Private (Derived_Type,
5338 Has_Private_Component (Derived_Type));
5339 Conditional_Delay (Derived_Type, Subt);
5341 -- Ada 2005 (AI-231): Set the null-exclusion attribute, and verify
5342 -- that it is not redundant.
5344 if Null_Exclusion_Present (Type_Definition (N)) then
5345 Set_Can_Never_Be_Null (Derived_Type);
5347 if Can_Never_Be_Null (Parent_Type)
5351 ("`NOT NULL` not allowed (& already excludes null)",
5355 elsif Can_Never_Be_Null (Parent_Type) then
5356 Set_Can_Never_Be_Null (Derived_Type);
5359 -- Note: we do not copy the Storage_Size_Variable, since we always go to
5360 -- the root type for this information.
5362 -- Apply range checks to discriminants for derived record case
5363 -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
5365 Desig_Type := Designated_Type (Derived_Type);
5366 if Is_Composite_Type (Desig_Type)
5367 and then (not Is_Array_Type (Desig_Type))
5368 and then Has_Discriminants (Desig_Type)
5369 and then Base_Type (Desig_Type) /= Desig_Type
5371 Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
5372 Discr_Con_El := First_Elmt (Discr_Con_Elist);
5374 Discr := First_Discriminant (Base_Type (Desig_Type));
5375 while Present (Discr_Con_El) loop
5376 Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
5377 Next_Elmt (Discr_Con_El);
5378 Next_Discriminant (Discr);
5381 end Build_Derived_Access_Type;
5383 ------------------------------
5384 -- Build_Derived_Array_Type --
5385 ------------------------------
5387 procedure Build_Derived_Array_Type
5389 Parent_Type : Entity_Id;
5390 Derived_Type : Entity_Id)
5392 Loc : constant Source_Ptr := Sloc (N);
5393 Tdef : constant Node_Id := Type_Definition (N);
5394 Indic : constant Node_Id := Subtype_Indication (Tdef);
5395 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
5396 Implicit_Base : Entity_Id;
5397 New_Indic : Node_Id;
5399 procedure Make_Implicit_Base;
5400 -- If the parent subtype is constrained, the derived type is a subtype
5401 -- of an implicit base type derived from the parent base.
5403 ------------------------
5404 -- Make_Implicit_Base --
5405 ------------------------
5407 procedure Make_Implicit_Base is
5410 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
5412 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
5413 Set_Etype (Implicit_Base, Parent_Base);
5415 Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
5416 Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
5418 Set_Has_Delayed_Freeze (Implicit_Base, True);
5419 end Make_Implicit_Base;
5421 -- Start of processing for Build_Derived_Array_Type
5424 if not Is_Constrained (Parent_Type) then
5425 if Nkind (Indic) /= N_Subtype_Indication then
5426 Set_Ekind (Derived_Type, E_Array_Type);
5428 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
5429 Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
5431 Set_Has_Delayed_Freeze (Derived_Type, True);
5435 Set_Etype (Derived_Type, Implicit_Base);
5438 Make_Subtype_Declaration (Loc,
5439 Defining_Identifier => Derived_Type,
5440 Subtype_Indication =>
5441 Make_Subtype_Indication (Loc,
5442 Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
5443 Constraint => Constraint (Indic)));
5445 Rewrite (N, New_Indic);
5450 if Nkind (Indic) /= N_Subtype_Indication then
5453 Set_Ekind (Derived_Type, Ekind (Parent_Type));
5454 Set_Etype (Derived_Type, Implicit_Base);
5455 Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
5458 Error_Msg_N ("illegal constraint on constrained type", Indic);
5462 -- If parent type is not a derived type itself, and is declared in
5463 -- closed scope (e.g. a subprogram), then we must explicitly introduce
5464 -- the new type's concatenation operator since Derive_Subprograms
5465 -- will not inherit the parent's operator. If the parent type is
5466 -- unconstrained, the operator is of the unconstrained base type.
5468 if Number_Dimensions (Parent_Type) = 1
5469 and then not Is_Limited_Type (Parent_Type)
5470 and then not Is_Derived_Type (Parent_Type)
5471 and then not Is_Package_Or_Generic_Package
5472 (Scope (Base_Type (Parent_Type)))
5474 if not Is_Constrained (Parent_Type)
5475 and then Is_Constrained (Derived_Type)
5477 New_Concatenation_Op (Implicit_Base);
5479 New_Concatenation_Op (Derived_Type);
5482 end Build_Derived_Array_Type;
5484 -----------------------------------
5485 -- Build_Derived_Concurrent_Type --
5486 -----------------------------------
5488 procedure Build_Derived_Concurrent_Type
5490 Parent_Type : Entity_Id;
5491 Derived_Type : Entity_Id)
5493 Loc : constant Source_Ptr := Sloc (N);
5495 Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C');
5496 Corr_Decl : Node_Id;
5497 Corr_Decl_Needed : Boolean;
5498 -- If the derived type has fewer discriminants than its parent, the
5499 -- corresponding record is also a derived type, in order to account for
5500 -- the bound discriminants. We create a full type declaration for it in
5503 Constraint_Present : constant Boolean :=
5504 Nkind (Subtype_Indication (Type_Definition (N))) =
5505 N_Subtype_Indication;
5507 D_Constraint : Node_Id;
5508 New_Constraint : Elist_Id;
5509 Old_Disc : Entity_Id;
5510 New_Disc : Entity_Id;
5514 Set_Stored_Constraint (Derived_Type, No_Elist);
5515 Corr_Decl_Needed := False;
5518 if Present (Discriminant_Specifications (N))
5519 and then Constraint_Present
5521 Old_Disc := First_Discriminant (Parent_Type);
5522 New_Disc := First (Discriminant_Specifications (N));
5523 while Present (New_Disc) and then Present (Old_Disc) loop
5524 Next_Discriminant (Old_Disc);
5529 if Present (Old_Disc) and then Expander_Active then
5531 -- The new type has fewer discriminants, so we need to create a new
5532 -- corresponding record, which is derived from the corresponding
5533 -- record of the parent, and has a stored constraint that captures
5534 -- the values of the discriminant constraints. The corresponding
5535 -- record is needed only if expander is active and code generation is
5538 -- The type declaration for the derived corresponding record has the
5539 -- same discriminant part and constraints as the current declaration.
5540 -- Copy the unanalyzed tree to build declaration.
5542 Corr_Decl_Needed := True;
5543 New_N := Copy_Separate_Tree (N);
5546 Make_Full_Type_Declaration (Loc,
5547 Defining_Identifier => Corr_Record,
5548 Discriminant_Specifications =>
5549 Discriminant_Specifications (New_N),
5551 Make_Derived_Type_Definition (Loc,
5552 Subtype_Indication =>
5553 Make_Subtype_Indication (Loc,
5556 (Corresponding_Record_Type (Parent_Type), Loc),
5559 (Subtype_Indication (Type_Definition (New_N))))));
5562 -- Copy Storage_Size and Relative_Deadline variables if task case
5564 if Is_Task_Type (Parent_Type) then
5565 Set_Storage_Size_Variable (Derived_Type,
5566 Storage_Size_Variable (Parent_Type));
5567 Set_Relative_Deadline_Variable (Derived_Type,
5568 Relative_Deadline_Variable (Parent_Type));
5571 if Present (Discriminant_Specifications (N)) then
5572 Push_Scope (Derived_Type);
5573 Check_Or_Process_Discriminants (N, Derived_Type);
5575 if Constraint_Present then
5577 Expand_To_Stored_Constraint
5579 Build_Discriminant_Constraints
5581 Subtype_Indication (Type_Definition (N)), True));
5586 elsif Constraint_Present then
5588 -- Build constrained subtype, copying the constraint, and derive
5589 -- from it to create a derived constrained type.
5592 Loc : constant Source_Ptr := Sloc (N);
5593 Anon : constant Entity_Id :=
5594 Make_Defining_Identifier (Loc,
5595 Chars => New_External_Name (Chars (Derived_Type), 'T'));
5600 Make_Subtype_Declaration (Loc,
5601 Defining_Identifier => Anon,
5602 Subtype_Indication =>
5603 New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
5604 Insert_Before (N, Decl);
5607 Rewrite (Subtype_Indication (Type_Definition (N)),
5608 New_Occurrence_Of (Anon, Loc));
5609 Set_Analyzed (Derived_Type, False);
5615 -- By default, operations and private data are inherited from parent.
5616 -- However, in the presence of bound discriminants, a new corresponding
5617 -- record will be created, see below.
5619 Set_Has_Discriminants
5620 (Derived_Type, Has_Discriminants (Parent_Type));
5621 Set_Corresponding_Record_Type
5622 (Derived_Type, Corresponding_Record_Type (Parent_Type));
5624 -- Is_Constrained is set according the parent subtype, but is set to
5625 -- False if the derived type is declared with new discriminants.
5629 (Is_Constrained (Parent_Type) or else Constraint_Present)
5630 and then not Present (Discriminant_Specifications (N)));
5632 if Constraint_Present then
5633 if not Has_Discriminants (Parent_Type) then
5634 Error_Msg_N ("untagged parent must have discriminants", N);
5636 elsif Present (Discriminant_Specifications (N)) then
5638 -- Verify that new discriminants are used to constrain old ones
5643 (Constraint (Subtype_Indication (Type_Definition (N)))));
5645 Old_Disc := First_Discriminant (Parent_Type);
5647 while Present (D_Constraint) loop
5648 if Nkind (D_Constraint) /= N_Discriminant_Association then
5650 -- Positional constraint. If it is a reference to a new
5651 -- discriminant, it constrains the corresponding old one.
5653 if Nkind (D_Constraint) = N_Identifier then
5654 New_Disc := First_Discriminant (Derived_Type);
5655 while Present (New_Disc) loop
5656 exit when Chars (New_Disc) = Chars (D_Constraint);
5657 Next_Discriminant (New_Disc);
5660 if Present (New_Disc) then
5661 Set_Corresponding_Discriminant (New_Disc, Old_Disc);
5665 Next_Discriminant (Old_Disc);
5667 -- if this is a named constraint, search by name for the old
5668 -- discriminants constrained by the new one.
5670 elsif Nkind (Expression (D_Constraint)) = N_Identifier then
5672 -- Find new discriminant with that name
5674 New_Disc := First_Discriminant (Derived_Type);
5675 while Present (New_Disc) loop
5677 Chars (New_Disc) = Chars (Expression (D_Constraint));
5678 Next_Discriminant (New_Disc);
5681 if Present (New_Disc) then
5683 -- Verify that new discriminant renames some discriminant
5684 -- of the parent type, and associate the new discriminant
5685 -- with one or more old ones that it renames.
5691 Selector := First (Selector_Names (D_Constraint));
5692 while Present (Selector) loop
5693 Old_Disc := First_Discriminant (Parent_Type);
5694 while Present (Old_Disc) loop
5695 exit when Chars (Old_Disc) = Chars (Selector);
5696 Next_Discriminant (Old_Disc);
5699 if Present (Old_Disc) then
5700 Set_Corresponding_Discriminant
5701 (New_Disc, Old_Disc);
5710 Next (D_Constraint);
5713 New_Disc := First_Discriminant (Derived_Type);
5714 while Present (New_Disc) loop
5715 if No (Corresponding_Discriminant (New_Disc)) then
5717 ("new discriminant& must constrain old one", N, New_Disc);
5720 Subtypes_Statically_Compatible
5722 Etype (Corresponding_Discriminant (New_Disc)))
5725 ("& not statically compatible with parent discriminant",
5729 Next_Discriminant (New_Disc);
5733 elsif Present (Discriminant_Specifications (N)) then
5735 ("missing discriminant constraint in untagged derivation", N);
5738 -- The entity chain of the derived type includes the new discriminants
5739 -- but shares operations with the parent.
5741 if Present (Discriminant_Specifications (N)) then
5742 Old_Disc := First_Discriminant (Parent_Type);
5743 while Present (Old_Disc) loop
5744 if No (Next_Entity (Old_Disc))
5745 or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
5748 (Last_Entity (Derived_Type), Next_Entity (Old_Disc));
5752 Next_Discriminant (Old_Disc);
5756 Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
5757 if Has_Discriminants (Parent_Type) then
5758 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
5759 Set_Discriminant_Constraint (
5760 Derived_Type, Discriminant_Constraint (Parent_Type));
5764 Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
5766 Set_Has_Completion (Derived_Type);
5768 if Corr_Decl_Needed then
5769 Set_Stored_Constraint (Derived_Type, New_Constraint);
5770 Insert_After (N, Corr_Decl);
5771 Analyze (Corr_Decl);
5772 Set_Corresponding_Record_Type (Derived_Type, Corr_Record);
5774 end Build_Derived_Concurrent_Type;
5776 ------------------------------------
5777 -- Build_Derived_Enumeration_Type --
5778 ------------------------------------
5780 procedure Build_Derived_Enumeration_Type
5782 Parent_Type : Entity_Id;
5783 Derived_Type : Entity_Id)
5785 Loc : constant Source_Ptr := Sloc (N);
5786 Def : constant Node_Id := Type_Definition (N);
5787 Indic : constant Node_Id := Subtype_Indication (Def);
5788 Implicit_Base : Entity_Id;
5789 Literal : Entity_Id;
5790 New_Lit : Entity_Id;
5791 Literals_List : List_Id;
5792 Type_Decl : Node_Id;
5794 Rang_Expr : Node_Id;
5797 -- Since types Standard.Character and Standard.[Wide_]Wide_Character do
5798 -- not have explicit literals lists we need to process types derived
5799 -- from them specially. This is handled by Derived_Standard_Character.
5800 -- If the parent type is a generic type, there are no literals either,
5801 -- and we construct the same skeletal representation as for the generic
5804 if Is_Standard_Character_Type (Parent_Type) then
5805 Derived_Standard_Character (N, Parent_Type, Derived_Type);
5807 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
5813 if Nkind (Indic) /= N_Subtype_Indication then
5815 Make_Attribute_Reference (Loc,
5816 Attribute_Name => Name_First,
5817 Prefix => New_Reference_To (Derived_Type, Loc));
5818 Set_Etype (Lo, Derived_Type);
5821 Make_Attribute_Reference (Loc,
5822 Attribute_Name => Name_Last,
5823 Prefix => New_Reference_To (Derived_Type, Loc));
5824 Set_Etype (Hi, Derived_Type);
5826 Set_Scalar_Range (Derived_Type,
5832 -- Analyze subtype indication and verify compatibility
5833 -- with parent type.
5835 if Base_Type (Process_Subtype (Indic, N)) /=
5836 Base_Type (Parent_Type)
5839 ("illegal constraint for formal discrete type", N);
5845 -- If a constraint is present, analyze the bounds to catch
5846 -- premature usage of the derived literals.
5848 if Nkind (Indic) = N_Subtype_Indication
5849 and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
5851 Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
5852 Analyze (High_Bound (Range_Expression (Constraint (Indic))));
5855 -- Introduce an implicit base type for the derived type even if there
5856 -- is no constraint attached to it, since this seems closer to the
5857 -- Ada semantics. Build a full type declaration tree for the derived
5858 -- type using the implicit base type as the defining identifier. The
5859 -- build a subtype declaration tree which applies the constraint (if
5860 -- any) have it replace the derived type declaration.
5862 Literal := First_Literal (Parent_Type);
5863 Literals_List := New_List;
5864 while Present (Literal)
5865 and then Ekind (Literal) = E_Enumeration_Literal
5867 -- Literals of the derived type have the same representation as
5868 -- those of the parent type, but this representation can be
5869 -- overridden by an explicit representation clause. Indicate
5870 -- that there is no explicit representation given yet. These
5871 -- derived literals are implicit operations of the new type,
5872 -- and can be overridden by explicit ones.
5874 if Nkind (Literal) = N_Defining_Character_Literal then
5876 Make_Defining_Character_Literal (Loc, Chars (Literal));
5878 New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
5881 Set_Ekind (New_Lit, E_Enumeration_Literal);
5882 Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
5883 Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
5884 Set_Enumeration_Rep_Expr (New_Lit, Empty);
5885 Set_Alias (New_Lit, Literal);
5886 Set_Is_Known_Valid (New_Lit, True);
5888 Append (New_Lit, Literals_List);
5889 Next_Literal (Literal);
5893 Make_Defining_Identifier (Sloc (Derived_Type),
5894 Chars => New_External_Name (Chars (Derived_Type), 'B'));
5896 -- Indicate the proper nature of the derived type. This must be done
5897 -- before analysis of the literals, to recognize cases when a literal
5898 -- may be hidden by a previous explicit function definition (cf.
5901 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
5902 Set_Etype (Derived_Type, Implicit_Base);
5905 Make_Full_Type_Declaration (Loc,
5906 Defining_Identifier => Implicit_Base,
5907 Discriminant_Specifications => No_List,
5909 Make_Enumeration_Type_Definition (Loc, Literals_List));
5911 Mark_Rewrite_Insertion (Type_Decl);
5912 Insert_Before (N, Type_Decl);
5913 Analyze (Type_Decl);
5915 -- After the implicit base is analyzed its Etype needs to be changed
5916 -- to reflect the fact that it is derived from the parent type which
5917 -- was ignored during analysis. We also set the size at this point.
5919 Set_Etype (Implicit_Base, Parent_Type);
5921 Set_Size_Info (Implicit_Base, Parent_Type);
5922 Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
5923 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
5925 -- Copy other flags from parent type
5927 Set_Has_Non_Standard_Rep
5928 (Implicit_Base, Has_Non_Standard_Rep
5930 Set_Has_Pragma_Ordered
5931 (Implicit_Base, Has_Pragma_Ordered
5933 Set_Has_Delayed_Freeze (Implicit_Base);
5935 -- Process the subtype indication including a validation check on the
5936 -- constraint, if any. If a constraint is given, its bounds must be
5937 -- implicitly converted to the new type.
5939 if Nkind (Indic) = N_Subtype_Indication then
5941 R : constant Node_Id :=
5942 Range_Expression (Constraint (Indic));
5945 if Nkind (R) = N_Range then
5946 Hi := Build_Scalar_Bound
5947 (High_Bound (R), Parent_Type, Implicit_Base);
5948 Lo := Build_Scalar_Bound
5949 (Low_Bound (R), Parent_Type, Implicit_Base);
5952 -- Constraint is a Range attribute. Replace with explicit
5953 -- mention of the bounds of the prefix, which must be a
5956 Analyze (Prefix (R));
5958 Convert_To (Implicit_Base,
5959 Make_Attribute_Reference (Loc,
5960 Attribute_Name => Name_Last,
5962 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
5965 Convert_To (Implicit_Base,
5966 Make_Attribute_Reference (Loc,
5967 Attribute_Name => Name_First,
5969 New_Occurrence_Of (Entity (Prefix (R)), Loc)));
5976 (Type_High_Bound (Parent_Type),
5977 Parent_Type, Implicit_Base);
5980 (Type_Low_Bound (Parent_Type),
5981 Parent_Type, Implicit_Base);
5989 -- If we constructed a default range for the case where no range
5990 -- was given, then the expressions in the range must not freeze
5991 -- since they do not correspond to expressions in the source.
5993 if Nkind (Indic) /= N_Subtype_Indication then
5994 Set_Must_Not_Freeze (Lo);
5995 Set_Must_Not_Freeze (Hi);
5996 Set_Must_Not_Freeze (Rang_Expr);
6000 Make_Subtype_Declaration (Loc,
6001 Defining_Identifier => Derived_Type,
6002 Subtype_Indication =>
6003 Make_Subtype_Indication (Loc,
6004 Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
6006 Make_Range_Constraint (Loc,
6007 Range_Expression => Rang_Expr))));
6011 -- Apply a range check. Since this range expression doesn't have an
6012 -- Etype, we have to specifically pass the Source_Typ parameter. Is
6015 if Nkind (Indic) = N_Subtype_Indication then
6016 Apply_Range_Check (Range_Expression (Constraint (Indic)),
6018 Source_Typ => Entity (Subtype_Mark (Indic)));
6021 end Build_Derived_Enumeration_Type;
6023 --------------------------------
6024 -- Build_Derived_Numeric_Type --
6025 --------------------------------
6027 procedure Build_Derived_Numeric_Type
6029 Parent_Type : Entity_Id;
6030 Derived_Type : Entity_Id)
6032 Loc : constant Source_Ptr := Sloc (N);
6033 Tdef : constant Node_Id := Type_Definition (N);
6034 Indic : constant Node_Id := Subtype_Indication (Tdef);
6035 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
6036 No_Constraint : constant Boolean := Nkind (Indic) /=
6037 N_Subtype_Indication;
6038 Implicit_Base : Entity_Id;
6044 -- Process the subtype indication including a validation check on
6045 -- the constraint if any.
6047 Discard_Node (Process_Subtype (Indic, N));
6049 -- Introduce an implicit base type for the derived type even if there
6050 -- is no constraint attached to it, since this seems closer to the Ada
6054 Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
6056 Set_Etype (Implicit_Base, Parent_Base);
6057 Set_Ekind (Implicit_Base, Ekind (Parent_Base));
6058 Set_Size_Info (Implicit_Base, Parent_Base);
6059 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
6060 Set_Parent (Implicit_Base, Parent (Derived_Type));
6061 Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base));
6063 -- Set RM Size for discrete type or decimal fixed-point type
6064 -- Ordinary fixed-point is excluded, why???
6066 if Is_Discrete_Type (Parent_Base)
6067 or else Is_Decimal_Fixed_Point_Type (Parent_Base)
6069 Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
6072 Set_Has_Delayed_Freeze (Implicit_Base);
6074 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
6075 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
6077 Set_Scalar_Range (Implicit_Base,
6082 if Has_Infinities (Parent_Base) then
6083 Set_Includes_Infinities (Scalar_Range (Implicit_Base));
6086 -- The Derived_Type, which is the entity of the declaration, is a
6087 -- subtype of the implicit base. Its Ekind is a subtype, even in the
6088 -- absence of an explicit constraint.
6090 Set_Etype (Derived_Type, Implicit_Base);
6092 -- If we did not have a constraint, then the Ekind is set from the
6093 -- parent type (otherwise Process_Subtype has set the bounds)
6095 if No_Constraint then
6096 Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
6099 -- If we did not have a range constraint, then set the range from the
6100 -- parent type. Otherwise, the Process_Subtype call has set the bounds.
6103 or else not Has_Range_Constraint (Indic)
6105 Set_Scalar_Range (Derived_Type,
6107 Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
6108 High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
6109 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
6111 if Has_Infinities (Parent_Type) then
6112 Set_Includes_Infinities (Scalar_Range (Derived_Type));
6115 Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type));
6118 Set_Is_Descendent_Of_Address (Derived_Type,
6119 Is_Descendent_Of_Address (Parent_Type));
6120 Set_Is_Descendent_Of_Address (Implicit_Base,
6121 Is_Descendent_Of_Address (Parent_Type));
6123 -- Set remaining type-specific fields, depending on numeric type
6125 if Is_Modular_Integer_Type (Parent_Type) then
6126 Set_Modulus (Implicit_Base, Modulus (Parent_Base));
6128 Set_Non_Binary_Modulus
6129 (Implicit_Base, Non_Binary_Modulus (Parent_Base));
6132 (Implicit_Base, Is_Known_Valid (Parent_Base));
6134 elsif Is_Floating_Point_Type (Parent_Type) then
6136 -- Digits of base type is always copied from the digits value of
6137 -- the parent base type, but the digits of the derived type will
6138 -- already have been set if there was a constraint present.
6140 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
6141 Set_Float_Rep (Implicit_Base, Float_Rep (Parent_Base));
6143 if No_Constraint then
6144 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
6147 elsif Is_Fixed_Point_Type (Parent_Type) then
6149 -- Small of base type and derived type are always copied from the
6150 -- parent base type, since smalls never change. The delta of the
6151 -- base type is also copied from the parent base type. However the
6152 -- delta of the derived type will have been set already if a
6153 -- constraint was present.
6155 Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
6156 Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
6157 Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
6159 if No_Constraint then
6160 Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
6163 -- The scale and machine radix in the decimal case are always
6164 -- copied from the parent base type.
6166 if Is_Decimal_Fixed_Point_Type (Parent_Type) then
6167 Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
6168 Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
6170 Set_Machine_Radix_10
6171 (Derived_Type, Machine_Radix_10 (Parent_Base));
6172 Set_Machine_Radix_10
6173 (Implicit_Base, Machine_Radix_10 (Parent_Base));
6175 Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
6177 if No_Constraint then
6178 Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
6181 -- the analysis of the subtype_indication sets the
6182 -- digits value of the derived type.
6189 -- The type of the bounds is that of the parent type, and they
6190 -- must be converted to the derived type.
6192 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
6194 -- The implicit_base should be frozen when the derived type is frozen,
6195 -- but note that it is used in the conversions of the bounds. For fixed
6196 -- types we delay the determination of the bounds until the proper
6197 -- freezing point. For other numeric types this is rejected by GCC, for
6198 -- reasons that are currently unclear (???), so we choose to freeze the
6199 -- implicit base now. In the case of integers and floating point types
6200 -- this is harmless because subsequent representation clauses cannot
6201 -- affect anything, but it is still baffling that we cannot use the
6202 -- same mechanism for all derived numeric types.
6204 -- There is a further complication: actually some representation
6205 -- clauses can affect the implicit base type. For example, attribute
6206 -- definition clauses for stream-oriented attributes need to set the
6207 -- corresponding TSS entries on the base type, and this normally
6208 -- cannot be done after the base type is frozen, so the circuitry in
6209 -- Sem_Ch13.New_Stream_Subprogram must account for this possibility
6210 -- and not use Set_TSS in this case.
6212 -- There are also consequences for the case of delayed representation
6213 -- aspects for some cases. For example, a Size aspect is delayed and
6214 -- should not be evaluated to the freeze point. This early freezing
6215 -- means that the size attribute evaluation happens too early???
6217 if Is_Fixed_Point_Type (Parent_Type) then
6218 Conditional_Delay (Implicit_Base, Parent_Type);
6220 Freeze_Before (N, Implicit_Base);
6222 end Build_Derived_Numeric_Type;
6224 --------------------------------
6225 -- Build_Derived_Private_Type --
6226 --------------------------------
6228 procedure Build_Derived_Private_Type
6230 Parent_Type : Entity_Id;
6231 Derived_Type : Entity_Id;
6232 Is_Completion : Boolean;
6233 Derive_Subps : Boolean := True)
6235 Loc : constant Source_Ptr := Sloc (N);
6236 Der_Base : Entity_Id;
6238 Full_Decl : Node_Id := Empty;
6239 Full_Der : Entity_Id;
6241 Last_Discr : Entity_Id;
6242 Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
6243 Swapped : Boolean := False;
6245 procedure Copy_And_Build;
6246 -- Copy derived type declaration, replace parent with its full view,
6247 -- and analyze new declaration.
6249 --------------------
6250 -- Copy_And_Build --
6251 --------------------
6253 procedure Copy_And_Build is
6257 if Ekind (Parent_Type) in Record_Kind
6259 (Ekind (Parent_Type) in Enumeration_Kind
6260 and then not Is_Standard_Character_Type (Parent_Type)
6261 and then not Is_Generic_Type (Root_Type (Parent_Type)))
6263 Full_N := New_Copy_Tree (N);
6264 Insert_After (N, Full_N);
6265 Build_Derived_Type (
6266 Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
6269 Build_Derived_Type (
6270 N, Parent_Type, Full_Der, True, Derive_Subps => False);
6274 -- Start of processing for Build_Derived_Private_Type
6277 if Is_Tagged_Type (Parent_Type) then
6278 Full_P := Full_View (Parent_Type);
6280 -- A type extension of a type with unknown discriminants is an
6281 -- indefinite type that the back-end cannot handle directly.
6282 -- We treat it as a private type, and build a completion that is
6283 -- derived from the full view of the parent, and hopefully has
6284 -- known discriminants.
6286 -- If the full view of the parent type has an underlying record view,
6287 -- use it to generate the underlying record view of this derived type
6288 -- (required for chains of derivations with unknown discriminants).
6290 -- Minor optimization: we avoid the generation of useless underlying
6291 -- record view entities if the private type declaration has unknown
6292 -- discriminants but its corresponding full view has no
6295 if Has_Unknown_Discriminants (Parent_Type)
6296 and then Present (Full_P)
6297 and then (Has_Discriminants (Full_P)
6298 or else Present (Underlying_Record_View (Full_P)))
6299 and then not In_Open_Scopes (Par_Scope)
6300 and then Expander_Active
6303 Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T');
6304 New_Ext : constant Node_Id :=
6306 (Record_Extension_Part (Type_Definition (N)));
6310 Build_Derived_Record_Type
6311 (N, Parent_Type, Derived_Type, Derive_Subps);
6313 -- Build anonymous completion, as a derivation from the full
6314 -- view of the parent. This is not a completion in the usual
6315 -- sense, because the current type is not private.
6318 Make_Full_Type_Declaration (Loc,
6319 Defining_Identifier => Full_Der,
6321 Make_Derived_Type_Definition (Loc,
6322 Subtype_Indication =>
6324 (Subtype_Indication (Type_Definition (N))),
6325 Record_Extension_Part => New_Ext));
6327 -- If the parent type has an underlying record view, use it
6328 -- here to build the new underlying record view.
6330 if Present (Underlying_Record_View (Full_P)) then
6332 (Nkind (Subtype_Indication (Type_Definition (Decl)))
6334 Set_Entity (Subtype_Indication (Type_Definition (Decl)),
6335 Underlying_Record_View (Full_P));
6338 Install_Private_Declarations (Par_Scope);
6339 Install_Visible_Declarations (Par_Scope);
6340 Insert_Before (N, Decl);
6342 -- Mark entity as an underlying record view before analysis,
6343 -- to avoid generating the list of its primitive operations
6344 -- (which is not really required for this entity) and thus
6345 -- prevent spurious errors associated with missing overriding
6346 -- of abstract primitives (overridden only for Derived_Type).
6348 Set_Ekind (Full_Der, E_Record_Type);
6349 Set_Is_Underlying_Record_View (Full_Der);
6353 pragma Assert (Has_Discriminants (Full_Der)
6354 and then not Has_Unknown_Discriminants (Full_Der));
6356 Uninstall_Declarations (Par_Scope);
6358 -- Freeze the underlying record view, to prevent generation of
6359 -- useless dispatching information, which is simply shared with
6360 -- the real derived type.
6362 Set_Is_Frozen (Full_Der);
6364 -- Set up links between real entity and underlying record view
6366 Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der));
6367 Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type);
6370 -- If discriminants are known, build derived record
6373 Build_Derived_Record_Type
6374 (N, Parent_Type, Derived_Type, Derive_Subps);
6379 elsif Has_Discriminants (Parent_Type) then
6380 if Present (Full_View (Parent_Type)) then
6381 if not Is_Completion then
6383 -- Copy declaration for subsequent analysis, to provide a
6384 -- completion for what is a private declaration. Indicate that
6385 -- the full type is internally generated.
6387 Full_Decl := New_Copy_Tree (N);
6388 Full_Der := New_Copy (Derived_Type);
6389 Set_Comes_From_Source (Full_Decl, False);
6390 Set_Comes_From_Source (Full_Der, False);
6391 Set_Parent (Full_Der, Full_Decl);
6393 Insert_After (N, Full_Decl);
6396 -- If this is a completion, the full view being built is itself
6397 -- private. We build a subtype of the parent with the same
6398 -- constraints as this full view, to convey to the back end the
6399 -- constrained components and the size of this subtype. If the
6400 -- parent is constrained, its full view can serve as the
6401 -- underlying full view of the derived type.
6403 if No (Discriminant_Specifications (N)) then
6404 if Nkind (Subtype_Indication (Type_Definition (N))) =
6405 N_Subtype_Indication
6407 Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
6409 elsif Is_Constrained (Full_View (Parent_Type)) then
6410 Set_Underlying_Full_View
6411 (Derived_Type, Full_View (Parent_Type));
6415 -- If there are new discriminants, the parent subtype is
6416 -- constrained by them, but it is not clear how to build
6417 -- the Underlying_Full_View in this case???
6424 -- Build partial view of derived type from partial view of parent
6426 Build_Derived_Record_Type
6427 (N, Parent_Type, Derived_Type, Derive_Subps);
6429 if Present (Full_View (Parent_Type)) and then not Is_Completion then
6430 if not In_Open_Scopes (Par_Scope)
6431 or else not In_Same_Source_Unit (N, Parent_Type)
6433 -- Swap partial and full views temporarily
6435 Install_Private_Declarations (Par_Scope);
6436 Install_Visible_Declarations (Par_Scope);
6440 -- Build full view of derived type from full view of parent which
6441 -- is now installed. Subprograms have been derived on the partial
6442 -- view, the completion does not derive them anew.
6444 if not Is_Tagged_Type (Parent_Type) then
6446 -- If the parent is itself derived from another private type,
6447 -- installing the private declarations has not affected its
6448 -- privacy status, so use its own full view explicitly.
6450 if Is_Private_Type (Parent_Type) then
6451 Build_Derived_Record_Type
6452 (Full_Decl, Full_View (Parent_Type), Full_Der, False);
6454 Build_Derived_Record_Type
6455 (Full_Decl, Parent_Type, Full_Der, False);
6459 -- If full view of parent is tagged, the completion inherits
6460 -- the proper primitive operations.
6462 Set_Defining_Identifier (Full_Decl, Full_Der);
6463 Build_Derived_Record_Type
6464 (Full_Decl, Parent_Type, Full_Der, Derive_Subps);
6467 -- The full declaration has been introduced into the tree and
6468 -- processed in the step above. It should not be analyzed again
6469 -- (when encountered later in the current list of declarations)
6470 -- to prevent spurious name conflicts. The full entity remains
6473 Set_Analyzed (Full_Decl);
6476 Uninstall_Declarations (Par_Scope);
6478 if In_Open_Scopes (Par_Scope) then
6479 Install_Visible_Declarations (Par_Scope);
6483 Der_Base := Base_Type (Derived_Type);
6484 Set_Full_View (Derived_Type, Full_Der);
6485 Set_Full_View (Der_Base, Base_Type (Full_Der));
6487 -- Copy the discriminant list from full view to the partial views
6488 -- (base type and its subtype). Gigi requires that the partial and
6489 -- full views have the same discriminants.
6491 -- Note that since the partial view is pointing to discriminants
6492 -- in the full view, their scope will be that of the full view.
6493 -- This might cause some front end problems and need adjustment???
6495 Discr := First_Discriminant (Base_Type (Full_Der));
6496 Set_First_Entity (Der_Base, Discr);
6499 Last_Discr := Discr;
6500 Next_Discriminant (Discr);
6501 exit when No (Discr);
6504 Set_Last_Entity (Der_Base, Last_Discr);
6506 Set_First_Entity (Derived_Type, First_Entity (Der_Base));
6507 Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
6508 Set_Stored_Constraint (Full_Der, Stored_Constraint (Derived_Type));
6511 -- If this is a completion, the derived type stays private and
6512 -- there is no need to create a further full view, except in the
6513 -- unusual case when the derivation is nested within a child unit,
6519 elsif Present (Full_View (Parent_Type))
6520 and then Has_Discriminants (Full_View (Parent_Type))
6522 if Has_Unknown_Discriminants (Parent_Type)
6523 and then Nkind (Subtype_Indication (Type_Definition (N))) =
6524 N_Subtype_Indication
6527 ("cannot constrain type with unknown discriminants",
6528 Subtype_Indication (Type_Definition (N)));
6532 -- If full view of parent is a record type, build full view as a
6533 -- derivation from the parent's full view. Partial view remains
6534 -- private. For code generation and linking, the full view must have
6535 -- the same public status as the partial one. This full view is only
6536 -- needed if the parent type is in an enclosing scope, so that the
6537 -- full view may actually become visible, e.g. in a child unit. This
6538 -- is both more efficient, and avoids order of freezing problems with
6539 -- the added entities.
6541 if not Is_Private_Type (Full_View (Parent_Type))
6542 and then (In_Open_Scopes (Scope (Parent_Type)))
6545 Make_Defining_Identifier (Sloc (Derived_Type),
6546 Chars => Chars (Derived_Type));
6548 Set_Is_Itype (Full_Der);
6549 Set_Has_Private_Declaration (Full_Der);
6550 Set_Has_Private_Declaration (Derived_Type);
6551 Set_Associated_Node_For_Itype (Full_Der, N);
6552 Set_Parent (Full_Der, Parent (Derived_Type));
6553 Set_Full_View (Derived_Type, Full_Der);
6554 Set_Is_Public (Full_Der, Is_Public (Derived_Type));
6555 Full_P := Full_View (Parent_Type);
6556 Exchange_Declarations (Parent_Type);
6558 Exchange_Declarations (Full_P);
6561 Build_Derived_Record_Type
6562 (N, Full_View (Parent_Type), Derived_Type,
6563 Derive_Subps => False);
6565 -- Except in the context of the full view of the parent, there
6566 -- are no non-extension aggregates for the derived type.
6568 Set_Has_Private_Ancestor (Derived_Type);
6571 -- In any case, the primitive operations are inherited from the
6572 -- parent type, not from the internal full view.
6574 Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
6576 if Derive_Subps then
6577 Derive_Subprograms (Parent_Type, Derived_Type);
6581 -- Untagged type, No discriminants on either view
6583 if Nkind (Subtype_Indication (Type_Definition (N))) =
6584 N_Subtype_Indication
6587 ("illegal constraint on type without discriminants", N);
6590 if Present (Discriminant_Specifications (N))
6591 and then Present (Full_View (Parent_Type))
6592 and then not Is_Tagged_Type (Full_View (Parent_Type))
6594 Error_Msg_N ("cannot add discriminants to untagged type", N);
6597 Set_Stored_Constraint (Derived_Type, No_Elist);
6598 Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
6599 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
6600 Set_Has_Controlled_Component
6601 (Derived_Type, Has_Controlled_Component
6604 -- Direct controlled types do not inherit Finalize_Storage_Only flag
6606 if not Is_Controlled (Parent_Type) then
6607 Set_Finalize_Storage_Only
6608 (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
6611 -- Construct the implicit full view by deriving from full view of the
6612 -- parent type. In order to get proper visibility, we install the
6613 -- parent scope and its declarations.
6615 -- ??? If the parent is untagged private and its completion is
6616 -- tagged, this mechanism will not work because we cannot derive from
6617 -- the tagged full view unless we have an extension.
6619 if Present (Full_View (Parent_Type))
6620 and then not Is_Tagged_Type (Full_View (Parent_Type))
6621 and then not Is_Completion
6624 Make_Defining_Identifier
6625 (Sloc (Derived_Type), Chars (Derived_Type));
6626 Set_Is_Itype (Full_Der);
6627 Set_Has_Private_Declaration (Full_Der);
6628 Set_Has_Private_Declaration (Derived_Type);
6629 Set_Associated_Node_For_Itype (Full_Der, N);
6630 Set_Parent (Full_Der, Parent (Derived_Type));
6631 Set_Full_View (Derived_Type, Full_Der);
6633 if not In_Open_Scopes (Par_Scope) then
6634 Install_Private_Declarations (Par_Scope);
6635 Install_Visible_Declarations (Par_Scope);
6637 Uninstall_Declarations (Par_Scope);
6639 -- If parent scope is open and in another unit, and parent has a
6640 -- completion, then the derivation is taking place in the visible
6641 -- part of a child unit. In that case retrieve the full view of
6642 -- the parent momentarily.
6644 elsif not In_Same_Source_Unit (N, Parent_Type) then
6645 Full_P := Full_View (Parent_Type);
6646 Exchange_Declarations (Parent_Type);
6648 Exchange_Declarations (Full_P);
6650 -- Otherwise it is a local derivation
6656 Set_Scope (Full_Der, Current_Scope);
6657 Set_Is_First_Subtype (Full_Der,
6658 Is_First_Subtype (Derived_Type));
6659 Set_Has_Size_Clause (Full_Der, False);
6660 Set_Has_Alignment_Clause (Full_Der, False);
6661 Set_Next_Entity (Full_Der, Empty);
6662 Set_Has_Delayed_Freeze (Full_Der);
6663 Set_Is_Frozen (Full_Der, False);
6664 Set_Freeze_Node (Full_Der, Empty);
6665 Set_Depends_On_Private (Full_Der,
6666 Has_Private_Component (Full_Der));
6667 Set_Public_Status (Full_Der);
6671 Set_Has_Unknown_Discriminants (Derived_Type,
6672 Has_Unknown_Discriminants (Parent_Type));
6674 if Is_Private_Type (Derived_Type) then
6675 Set_Private_Dependents (Derived_Type, New_Elmt_List);
6678 if Is_Private_Type (Parent_Type)
6679 and then Base_Type (Parent_Type) = Parent_Type
6680 and then In_Open_Scopes (Scope (Parent_Type))
6682 Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
6684 -- Check for unusual case where a type completed by a private
6685 -- derivation occurs within a package nested in a child unit, and
6686 -- the parent is declared in an ancestor.
6688 if Is_Child_Unit (Scope (Current_Scope))
6689 and then Is_Completion
6690 and then In_Private_Part (Current_Scope)
6691 and then Scope (Parent_Type) /= Current_Scope
6693 -- Note that if the parent has a completion in the private part,
6694 -- (which is itself a derivation from some other private type)
6695 -- it is that completion that is visible, there is no full view
6696 -- available, and no special processing is needed.
6698 and then Present (Full_View (Parent_Type))
6700 -- In this case, the full view of the parent type will become
6701 -- visible in the body of the enclosing child, and only then will
6702 -- the current type be possibly non-private. We build an
6703 -- underlying full view that will be installed when the enclosing
6704 -- child body is compiled.
6707 Make_Defining_Identifier
6708 (Sloc (Derived_Type), Chars (Derived_Type));
6709 Set_Is_Itype (Full_Der);
6710 Build_Itype_Reference (Full_Der, N);
6712 -- The full view will be used to swap entities on entry/exit to
6713 -- the body, and must appear in the entity list for the package.
6715 Append_Entity (Full_Der, Scope (Derived_Type));
6716 Set_Has_Private_Declaration (Full_Der);
6717 Set_Has_Private_Declaration (Derived_Type);
6718 Set_Associated_Node_For_Itype (Full_Der, N);
6719 Set_Parent (Full_Der, Parent (Derived_Type));
6720 Full_P := Full_View (Parent_Type);
6721 Exchange_Declarations (Parent_Type);
6723 Exchange_Declarations (Full_P);
6724 Set_Underlying_Full_View (Derived_Type, Full_Der);
6727 end Build_Derived_Private_Type;
6729 -------------------------------
6730 -- Build_Derived_Record_Type --
6731 -------------------------------
6735 -- Ideally we would like to use the same model of type derivation for
6736 -- tagged and untagged record types. Unfortunately this is not quite
6737 -- possible because the semantics of representation clauses is different
6738 -- for tagged and untagged records under inheritance. Consider the
6741 -- type R (...) is [tagged] record ... end record;
6742 -- type T (...) is new R (...) [with ...];
6744 -- The representation clauses for T can specify a completely different
6745 -- record layout from R's. Hence the same component can be placed in two
6746 -- very different positions in objects of type T and R. If R and T are
6747 -- tagged types, representation clauses for T can only specify the layout
6748 -- of non inherited components, thus components that are common in R and T
6749 -- have the same position in objects of type R and T.
6751 -- This has two implications. The first is that the entire tree for R's
6752 -- declaration needs to be copied for T in the untagged case, so that T
6753 -- can be viewed as a record type of its own with its own representation
6754 -- clauses. The second implication is the way we handle discriminants.
6755 -- Specifically, in the untagged case we need a way to communicate to Gigi
6756 -- what are the real discriminants in the record, while for the semantics
6757 -- we need to consider those introduced by the user to rename the
6758 -- discriminants in the parent type. This is handled by introducing the
6759 -- notion of stored discriminants. See below for more.
6761 -- Fortunately the way regular components are inherited can be handled in
6762 -- the same way in tagged and untagged types.
6764 -- To complicate things a bit more the private view of a private extension
6765 -- cannot be handled in the same way as the full view (for one thing the
6766 -- semantic rules are somewhat different). We will explain what differs
6769 -- 2. DISCRIMINANTS UNDER INHERITANCE
6771 -- The semantic rules governing the discriminants of derived types are
6774 -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
6775 -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
6777 -- If parent type has discriminants, then the discriminants that are
6778 -- declared in the derived type are [3.4 (11)]:
6780 -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
6783 -- o Otherwise, each discriminant of the parent type (implicitly declared
6784 -- in the same order with the same specifications). In this case, the
6785 -- discriminants are said to be "inherited", or if unknown in the parent
6786 -- are also unknown in the derived type.
6788 -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
6790 -- o The parent subtype shall be constrained;
6792 -- o If the parent type is not a tagged type, then each discriminant of
6793 -- the derived type shall be used in the constraint defining a parent
6794 -- subtype. [Implementation note: This ensures that the new discriminant
6795 -- can share storage with an existing discriminant.]
6797 -- For the derived type each discriminant of the parent type is either
6798 -- inherited, constrained to equal some new discriminant of the derived
6799 -- type, or constrained to the value of an expression.
6801 -- When inherited or constrained to equal some new discriminant, the
6802 -- parent discriminant and the discriminant of the derived type are said
6805 -- If a discriminant of the parent type is constrained to a specific value
6806 -- in the derived type definition, then the discriminant is said to be
6807 -- "specified" by that derived type definition.
6809 -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
6811 -- We have spoken about stored discriminants in point 1 (introduction)
6812 -- above. There are two sort of stored discriminants: implicit and
6813 -- explicit. As long as the derived type inherits the same discriminants as
6814 -- the root record type, stored discriminants are the same as regular
6815 -- discriminants, and are said to be implicit. However, if any discriminant
6816 -- in the root type was renamed in the derived type, then the derived
6817 -- type will contain explicit stored discriminants. Explicit stored
6818 -- discriminants are discriminants in addition to the semantically visible
6819 -- discriminants defined for the derived type. Stored discriminants are
6820 -- used by Gigi to figure out what are the physical discriminants in
6821 -- objects of the derived type (see precise definition in einfo.ads).
6822 -- As an example, consider the following:
6824 -- type R (D1, D2, D3 : Int) is record ... end record;
6825 -- type T1 is new R;
6826 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
6827 -- type T3 is new T2;
6828 -- type T4 (Y : Int) is new T3 (Y, 99);
6830 -- The following table summarizes the discriminants and stored
6831 -- discriminants in R and T1 through T4.
6833 -- Type Discrim Stored Discrim Comment
6834 -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
6835 -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
6836 -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
6837 -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
6838 -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
6840 -- Field Corresponding_Discriminant (abbreviated CD below) allows us to
6841 -- find the corresponding discriminant in the parent type, while
6842 -- Original_Record_Component (abbreviated ORC below), the actual physical
6843 -- component that is renamed. Finally the field Is_Completely_Hidden
6844 -- (abbreviated ICH below) is set for all explicit stored discriminants
6845 -- (see einfo.ads for more info). For the above example this gives:
6847 -- Discrim CD ORC ICH
6848 -- ^^^^^^^ ^^ ^^^ ^^^
6849 -- D1 in R empty itself no
6850 -- D2 in R empty itself no
6851 -- D3 in R empty itself no
6853 -- D1 in T1 D1 in R itself no
6854 -- D2 in T1 D2 in R itself no
6855 -- D3 in T1 D3 in R itself no
6857 -- X1 in T2 D3 in T1 D3 in T2 no
6858 -- X2 in T2 D1 in T1 D1 in T2 no
6859 -- D1 in T2 empty itself yes
6860 -- D2 in T2 empty itself yes
6861 -- D3 in T2 empty itself yes
6863 -- X1 in T3 X1 in T2 D3 in T3 no
6864 -- X2 in T3 X2 in T2 D1 in T3 no
6865 -- D1 in T3 empty itself yes
6866 -- D2 in T3 empty itself yes
6867 -- D3 in T3 empty itself yes
6869 -- Y in T4 X1 in T3 D3 in T3 no
6870 -- D1 in T3 empty itself yes
6871 -- D2 in T3 empty itself yes
6872 -- D3 in T3 empty itself yes
6874 -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
6876 -- Type derivation for tagged types is fairly straightforward. If no
6877 -- discriminants are specified by the derived type, these are inherited
6878 -- from the parent. No explicit stored discriminants are ever necessary.
6879 -- The only manipulation that is done to the tree is that of adding a
6880 -- _parent field with parent type and constrained to the same constraint
6881 -- specified for the parent in the derived type definition. For instance:
6883 -- type R (D1, D2, D3 : Int) is tagged record ... end record;
6884 -- type T1 is new R with null record;
6885 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
6887 -- are changed into:
6889 -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
6890 -- _parent : R (D1, D2, D3);
6893 -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
6894 -- _parent : T1 (X2, 88, X1);
6897 -- The discriminants actually present in R, T1 and T2 as well as their CD,
6898 -- ORC and ICH fields are:
6900 -- Discrim CD ORC ICH
6901 -- ^^^^^^^ ^^ ^^^ ^^^
6902 -- D1 in R empty itself no
6903 -- D2 in R empty itself no
6904 -- D3 in R empty itself no
6906 -- D1 in T1 D1 in R D1 in R no
6907 -- D2 in T1 D2 in R D2 in R no
6908 -- D3 in T1 D3 in R D3 in R no
6910 -- X1 in T2 D3 in T1 D3 in R no
6911 -- X2 in T2 D1 in T1 D1 in R no
6913 -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
6915 -- Regardless of whether we dealing with a tagged or untagged type
6916 -- we will transform all derived type declarations of the form
6918 -- type T is new R (...) [with ...];
6920 -- subtype S is R (...);
6921 -- type T is new S [with ...];
6923 -- type BT is new R [with ...];
6924 -- subtype T is BT (...);
6926 -- That is, the base derived type is constrained only if it has no
6927 -- discriminants. The reason for doing this is that GNAT's semantic model
6928 -- assumes that a base type with discriminants is unconstrained.
6930 -- Note that, strictly speaking, the above transformation is not always
6931 -- correct. Consider for instance the following excerpt from ACVC b34011a:
6933 -- procedure B34011A is
6934 -- type REC (D : integer := 0) is record
6939 -- type T6 is new Rec;
6940 -- function F return T6;
6945 -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
6948 -- The definition of Q6.U is illegal. However transforming Q6.U into
6950 -- type BaseU is new T6;
6951 -- subtype U is BaseU (Q6.F.I)
6953 -- turns U into a legal subtype, which is incorrect. To avoid this problem
6954 -- we always analyze the constraint (in this case (Q6.F.I)) before applying
6955 -- the transformation described above.
6957 -- There is another instance where the above transformation is incorrect.
6961 -- type Base (D : Integer) is tagged null record;
6962 -- procedure P (X : Base);
6964 -- type Der is new Base (2) with null record;
6965 -- procedure P (X : Der);
6968 -- Then the above transformation turns this into
6970 -- type Der_Base is new Base with null record;
6971 -- -- procedure P (X : Base) is implicitly inherited here
6972 -- -- as procedure P (X : Der_Base).
6974 -- subtype Der is Der_Base (2);
6975 -- procedure P (X : Der);
6976 -- -- The overriding of P (X : Der_Base) is illegal since we
6977 -- -- have a parameter conformance problem.
6979 -- To get around this problem, after having semantically processed Der_Base
6980 -- and the rewritten subtype declaration for Der, we copy Der_Base field
6981 -- Discriminant_Constraint from Der so that when parameter conformance is
6982 -- checked when P is overridden, no semantic errors are flagged.
6984 -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
6986 -- Regardless of whether we are dealing with a tagged or untagged type
6987 -- we will transform all derived type declarations of the form
6989 -- type R (D1, .., Dn : ...) is [tagged] record ...;
6990 -- type T is new R [with ...];
6992 -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
6994 -- The reason for such transformation is that it allows us to implement a
6995 -- very clean form of component inheritance as explained below.
6997 -- Note that this transformation is not achieved by direct tree rewriting
6998 -- and manipulation, but rather by redoing the semantic actions that the
6999 -- above transformation will entail. This is done directly in routine
7000 -- Inherit_Components.
7002 -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
7004 -- In both tagged and untagged derived types, regular non discriminant
7005 -- components are inherited in the derived type from the parent type. In
7006 -- the absence of discriminants component, inheritance is straightforward
7007 -- as components can simply be copied from the parent.
7009 -- If the parent has discriminants, inheriting components constrained with
7010 -- these discriminants requires caution. Consider the following example:
7012 -- type R (D1, D2 : Positive) is [tagged] record
7013 -- S : String (D1 .. D2);
7016 -- type T1 is new R [with null record];
7017 -- type T2 (X : positive) is new R (1, X) [with null record];
7019 -- As explained in 6. above, T1 is rewritten as
7020 -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
7021 -- which makes the treatment for T1 and T2 identical.
7023 -- What we want when inheriting S, is that references to D1 and D2 in R are
7024 -- replaced with references to their correct constraints, i.e. D1 and D2 in
7025 -- T1 and 1 and X in T2. So all R's discriminant references are replaced
7026 -- with either discriminant references in the derived type or expressions.
7027 -- This replacement is achieved as follows: before inheriting R's
7028 -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
7029 -- created in the scope of T1 (resp. scope of T2) so that discriminants D1
7030 -- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
7031 -- For T2, for instance, this has the effect of replacing String (D1 .. D2)
7032 -- by String (1 .. X).
7034 -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
7036 -- We explain here the rules governing private type extensions relevant to
7037 -- type derivation. These rules are explained on the following example:
7039 -- type D [(...)] is new A [(...)] with private; <-- partial view
7040 -- type D [(...)] is new P [(...)] with null record; <-- full view
7042 -- Type A is called the ancestor subtype of the private extension.
7043 -- Type P is the parent type of the full view of the private extension. It
7044 -- must be A or a type derived from A.
7046 -- The rules concerning the discriminants of private type extensions are
7049 -- o If a private extension inherits known discriminants from the ancestor
7050 -- subtype, then the full view shall also inherit its discriminants from
7051 -- the ancestor subtype and the parent subtype of the full view shall be
7052 -- constrained if and only if the ancestor subtype is constrained.
7054 -- o If a partial view has unknown discriminants, then the full view may
7055 -- define a definite or an indefinite subtype, with or without
7058 -- o If a partial view has neither known nor unknown discriminants, then
7059 -- the full view shall define a definite subtype.
7061 -- o If the ancestor subtype of a private extension has constrained
7062 -- discriminants, then the parent subtype of the full view shall impose a
7063 -- statically matching constraint on those discriminants.
7065 -- This means that only the following forms of private extensions are
7068 -- type D is new A with private; <-- partial view
7069 -- type D is new P with null record; <-- full view
7071 -- If A has no discriminants than P has no discriminants, otherwise P must
7072 -- inherit A's discriminants.
7074 -- type D is new A (...) with private; <-- partial view
7075 -- type D is new P (:::) with null record; <-- full view
7077 -- P must inherit A's discriminants and (...) and (:::) must statically
7080 -- subtype A is R (...);
7081 -- type D is new A with private; <-- partial view
7082 -- type D is new P with null record; <-- full view
7084 -- P must have inherited R's discriminants and must be derived from A or
7085 -- any of its subtypes.
7087 -- type D (..) is new A with private; <-- partial view
7088 -- type D (..) is new P [(:::)] with null record; <-- full view
7090 -- No specific constraints on P's discriminants or constraint (:::).
7091 -- Note that A can be unconstrained, but the parent subtype P must either
7092 -- be constrained or (:::) must be present.
7094 -- type D (..) is new A [(...)] with private; <-- partial view
7095 -- type D (..) is new P [(:::)] with null record; <-- full view
7097 -- P's constraints on A's discriminants must statically match those
7098 -- imposed by (...).
7100 -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
7102 -- The full view of a private extension is handled exactly as described
7103 -- above. The model chose for the private view of a private extension is
7104 -- the same for what concerns discriminants (i.e. they receive the same
7105 -- treatment as in the tagged case). However, the private view of the
7106 -- private extension always inherits the components of the parent base,
7107 -- without replacing any discriminant reference. Strictly speaking this is
7108 -- incorrect. However, Gigi never uses this view to generate code so this
7109 -- is a purely semantic issue. In theory, a set of transformations similar
7110 -- to those given in 5. and 6. above could be applied to private views of
7111 -- private extensions to have the same model of component inheritance as
7112 -- for non private extensions. However, this is not done because it would
7113 -- further complicate private type processing. Semantically speaking, this
7114 -- leaves us in an uncomfortable situation. As an example consider:
7117 -- type R (D : integer) is tagged record
7118 -- S : String (1 .. D);
7120 -- procedure P (X : R);
7121 -- type T is new R (1) with private;
7123 -- type T is new R (1) with null record;
7126 -- This is transformed into:
7129 -- type R (D : integer) is tagged record
7130 -- S : String (1 .. D);
7132 -- procedure P (X : R);
7133 -- type T is new R (1) with private;
7135 -- type BaseT is new R with null record;
7136 -- subtype T is BaseT (1);
7139 -- (strictly speaking the above is incorrect Ada)
7141 -- From the semantic standpoint the private view of private extension T
7142 -- should be flagged as constrained since one can clearly have
7146 -- in a unit withing Pack. However, when deriving subprograms for the
7147 -- private view of private extension T, T must be seen as unconstrained
7148 -- since T has discriminants (this is a constraint of the current
7149 -- subprogram derivation model). Thus, when processing the private view of
7150 -- a private extension such as T, we first mark T as unconstrained, we
7151 -- process it, we perform program derivation and just before returning from
7152 -- Build_Derived_Record_Type we mark T as constrained.
7154 -- ??? Are there are other uncomfortable cases that we will have to
7157 -- 10. RECORD_TYPE_WITH_PRIVATE complications
7159 -- Types that are derived from a visible record type and have a private
7160 -- extension present other peculiarities. They behave mostly like private
7161 -- types, but if they have primitive operations defined, these will not
7162 -- have the proper signatures for further inheritance, because other
7163 -- primitive operations will use the implicit base that we define for
7164 -- private derivations below. This affect subprogram inheritance (see
7165 -- Derive_Subprograms for details). We also derive the implicit base from
7166 -- the base type of the full view, so that the implicit base is a record
7167 -- type and not another private type, This avoids infinite loops.
7169 procedure Build_Derived_Record_Type
7171 Parent_Type : Entity_Id;
7172 Derived_Type : Entity_Id;
7173 Derive_Subps : Boolean := True)
7175 Discriminant_Specs : constant Boolean :=
7176 Present (Discriminant_Specifications (N));
7177 Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
7178 Loc : constant Source_Ptr := Sloc (N);
7179 Private_Extension : constant Boolean :=
7180 Nkind (N) = N_Private_Extension_Declaration;
7181 Assoc_List : Elist_Id;
7182 Constraint_Present : Boolean;
7184 Discrim : Entity_Id;
7186 Inherit_Discrims : Boolean := False;
7187 Last_Discrim : Entity_Id;
7188 New_Base : Entity_Id;
7190 New_Discrs : Elist_Id;
7191 New_Indic : Node_Id;
7192 Parent_Base : Entity_Id;
7193 Save_Etype : Entity_Id;
7194 Save_Discr_Constr : Elist_Id;
7195 Save_Next_Entity : Entity_Id;
7198 Discs : Elist_Id := New_Elmt_List;
7199 -- An empty Discs list means that there were no constraints in the
7200 -- subtype indication or that there was an error processing it.
7203 if Ekind (Parent_Type) = E_Record_Type_With_Private
7204 and then Present (Full_View (Parent_Type))
7205 and then Has_Discriminants (Parent_Type)
7207 Parent_Base := Base_Type (Full_View (Parent_Type));
7209 Parent_Base := Base_Type (Parent_Type);
7212 -- AI05-0115 : if this is a derivation from a private type in some
7213 -- other scope that may lead to invisible components for the derived
7214 -- type, mark it accordingly.
7216 if Is_Private_Type (Parent_Type) then
7217 if Scope (Parent_Type) = Scope (Derived_Type) then
7220 elsif In_Open_Scopes (Scope (Parent_Type))
7221 and then In_Private_Part (Scope (Parent_Type))
7226 Set_Has_Private_Ancestor (Derived_Type);
7230 Set_Has_Private_Ancestor
7231 (Derived_Type, Has_Private_Ancestor (Parent_Type));
7234 -- Before we start the previously documented transformations, here is
7235 -- little fix for size and alignment of tagged types. Normally when we
7236 -- derive type D from type P, we copy the size and alignment of P as the
7237 -- default for D, and in the absence of explicit representation clauses
7238 -- for D, the size and alignment are indeed the same as the parent.
7240 -- But this is wrong for tagged types, since fields may be added, and
7241 -- the default size may need to be larger, and the default alignment may
7242 -- need to be larger.
7244 -- We therefore reset the size and alignment fields in the tagged case.
7245 -- Note that the size and alignment will in any case be at least as
7246 -- large as the parent type (since the derived type has a copy of the
7247 -- parent type in the _parent field)
7249 -- The type is also marked as being tagged here, which is needed when
7250 -- processing components with a self-referential anonymous access type
7251 -- in the call to Check_Anonymous_Access_Components below. Note that
7252 -- this flag is also set later on for completeness.
7255 Set_Is_Tagged_Type (Derived_Type);
7256 Init_Size_Align (Derived_Type);
7259 -- STEP 0a: figure out what kind of derived type declaration we have
7261 if Private_Extension then
7263 Set_Ekind (Derived_Type, E_Record_Type_With_Private);
7266 Type_Def := Type_Definition (N);
7268 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
7269 -- Parent_Base can be a private type or private extension. However,
7270 -- for tagged types with an extension the newly added fields are
7271 -- visible and hence the Derived_Type is always an E_Record_Type.
7272 -- (except that the parent may have its own private fields).
7273 -- For untagged types we preserve the Ekind of the Parent_Base.
7275 if Present (Record_Extension_Part (Type_Def)) then
7276 Set_Ekind (Derived_Type, E_Record_Type);
7278 -- Create internal access types for components with anonymous
7281 if Ada_Version >= Ada_2005 then
7282 Check_Anonymous_Access_Components
7283 (N, Derived_Type, Derived_Type,
7284 Component_List (Record_Extension_Part (Type_Def)));
7288 Set_Ekind (Derived_Type, Ekind (Parent_Base));
7292 -- Indic can either be an N_Identifier if the subtype indication
7293 -- contains no constraint or an N_Subtype_Indication if the subtype
7294 -- indication has a constraint.
7296 Indic := Subtype_Indication (Type_Def);
7297 Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
7299 -- Check that the type has visible discriminants. The type may be
7300 -- a private type with unknown discriminants whose full view has
7301 -- discriminants which are invisible.
7303 if Constraint_Present then
7304 if not Has_Discriminants (Parent_Base)
7306 (Has_Unknown_Discriminants (Parent_Base)
7307 and then Is_Private_Type (Parent_Base))
7310 ("invalid constraint: type has no discriminant",
7311 Constraint (Indic));
7313 Constraint_Present := False;
7314 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
7316 elsif Is_Constrained (Parent_Type) then
7318 ("invalid constraint: parent type is already constrained",
7319 Constraint (Indic));
7321 Constraint_Present := False;
7322 Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
7326 -- STEP 0b: If needed, apply transformation given in point 5. above
7328 if not Private_Extension
7329 and then Has_Discriminants (Parent_Type)
7330 and then not Discriminant_Specs
7331 and then (Is_Constrained (Parent_Type) or else Constraint_Present)
7333 -- First, we must analyze the constraint (see comment in point 5.)
7335 if Constraint_Present then
7336 New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
7338 if Has_Discriminants (Derived_Type)
7339 and then Has_Private_Declaration (Derived_Type)
7340 and then Present (Discriminant_Constraint (Derived_Type))
7342 -- Verify that constraints of the full view statically match
7343 -- those given in the partial view.
7349 C1 := First_Elmt (New_Discrs);
7350 C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
7351 while Present (C1) and then Present (C2) loop
7352 if Fully_Conformant_Expressions (Node (C1), Node (C2))
7354 (Is_OK_Static_Expression (Node (C1))
7356 Is_OK_Static_Expression (Node (C2))
7358 Expr_Value (Node (C1)) = Expr_Value (Node (C2)))
7364 "constraint not conformant to previous declaration",
7375 -- Insert and analyze the declaration for the unconstrained base type
7377 New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
7380 Make_Full_Type_Declaration (Loc,
7381 Defining_Identifier => New_Base,
7383 Make_Derived_Type_Definition (Loc,
7384 Abstract_Present => Abstract_Present (Type_Def),
7385 Limited_Present => Limited_Present (Type_Def),
7386 Subtype_Indication =>
7387 New_Occurrence_Of (Parent_Base, Loc),
7388 Record_Extension_Part =>
7389 Relocate_Node (Record_Extension_Part (Type_Def)),
7390 Interface_List => Interface_List (Type_Def)));
7392 Set_Parent (New_Decl, Parent (N));
7393 Mark_Rewrite_Insertion (New_Decl);
7394 Insert_Before (N, New_Decl);
7396 -- In the extension case, make sure ancestor is frozen appropriately
7397 -- (see also non-discriminated case below).
7399 if Present (Record_Extension_Part (Type_Def))
7400 or else Is_Interface (Parent_Base)
7402 Freeze_Before (New_Decl, Parent_Type);
7405 -- Note that this call passes False for the Derive_Subps parameter
7406 -- because subprogram derivation is deferred until after creating
7407 -- the subtype (see below).
7410 (New_Decl, Parent_Base, New_Base,
7411 Is_Completion => True, Derive_Subps => False);
7413 -- ??? This needs re-examination to determine whether the
7414 -- above call can simply be replaced by a call to Analyze.
7416 Set_Analyzed (New_Decl);
7418 -- Insert and analyze the declaration for the constrained subtype
7420 if Constraint_Present then
7422 Make_Subtype_Indication (Loc,
7423 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
7424 Constraint => Relocate_Node (Constraint (Indic)));
7428 Constr_List : constant List_Id := New_List;
7433 C := First_Elmt (Discriminant_Constraint (Parent_Type));
7434 while Present (C) loop
7437 -- It is safe here to call New_Copy_Tree since
7438 -- Force_Evaluation was called on each constraint in
7439 -- Build_Discriminant_Constraints.
7441 Append (New_Copy_Tree (Expr), To => Constr_List);
7447 Make_Subtype_Indication (Loc,
7448 Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
7450 Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
7455 Make_Subtype_Declaration (Loc,
7456 Defining_Identifier => Derived_Type,
7457 Subtype_Indication => New_Indic));
7461 -- Derivation of subprograms must be delayed until the full subtype
7462 -- has been established, to ensure proper overriding of subprograms
7463 -- inherited by full types. If the derivations occurred as part of
7464 -- the call to Build_Derived_Type above, then the check for type
7465 -- conformance would fail because earlier primitive subprograms
7466 -- could still refer to the full type prior the change to the new
7467 -- subtype and hence would not match the new base type created here.
7468 -- Subprograms are not derived, however, when Derive_Subps is False
7469 -- (since otherwise there could be redundant derivations).
7471 if Derive_Subps then
7472 Derive_Subprograms (Parent_Type, Derived_Type);
7475 -- For tagged types the Discriminant_Constraint of the new base itype
7476 -- is inherited from the first subtype so that no subtype conformance
7477 -- problem arise when the first subtype overrides primitive
7478 -- operations inherited by the implicit base type.
7481 Set_Discriminant_Constraint
7482 (New_Base, Discriminant_Constraint (Derived_Type));
7488 -- If we get here Derived_Type will have no discriminants or it will be
7489 -- a discriminated unconstrained base type.
7491 -- STEP 1a: perform preliminary actions/checks for derived tagged types
7495 -- The parent type is frozen for non-private extensions (RM 13.14(7))
7496 -- The declaration of a specific descendant of an interface type
7497 -- freezes the interface type (RM 13.14).
7499 if not Private_Extension or else Is_Interface (Parent_Base) then
7500 Freeze_Before (N, Parent_Type);
7503 -- In Ada 2005 (AI-344), the restriction that a derived tagged type
7504 -- cannot be declared at a deeper level than its parent type is
7505 -- removed. The check on derivation within a generic body is also
7506 -- relaxed, but there's a restriction that a derived tagged type
7507 -- cannot be declared in a generic body if it's derived directly
7508 -- or indirectly from a formal type of that generic.
7510 if Ada_Version >= Ada_2005 then
7511 if Present (Enclosing_Generic_Body (Derived_Type)) then
7513 Ancestor_Type : Entity_Id;
7516 -- Check to see if any ancestor of the derived type is a
7519 Ancestor_Type := Parent_Type;
7520 while not Is_Generic_Type (Ancestor_Type)
7521 and then Etype (Ancestor_Type) /= Ancestor_Type
7523 Ancestor_Type := Etype (Ancestor_Type);
7526 -- If the derived type does have a formal type as an
7527 -- ancestor, then it's an error if the derived type is
7528 -- declared within the body of the generic unit that
7529 -- declares the formal type in its generic formal part. It's
7530 -- sufficient to check whether the ancestor type is declared
7531 -- inside the same generic body as the derived type (such as
7532 -- within a nested generic spec), in which case the
7533 -- derivation is legal. If the formal type is declared
7534 -- outside of that generic body, then it's guaranteed that
7535 -- the derived type is declared within the generic body of
7536 -- the generic unit declaring the formal type.
7538 if Is_Generic_Type (Ancestor_Type)
7539 and then Enclosing_Generic_Body (Ancestor_Type) /=
7540 Enclosing_Generic_Body (Derived_Type)
7543 ("parent type of& must not be descendant of formal type"
7544 & " of an enclosing generic body",
7545 Indic, Derived_Type);
7550 elsif Type_Access_Level (Derived_Type) /=
7551 Type_Access_Level (Parent_Type)
7552 and then not Is_Generic_Type (Derived_Type)
7554 if Is_Controlled (Parent_Type) then
7556 ("controlled type must be declared at the library level",
7560 ("type extension at deeper accessibility level than parent",
7566 GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
7570 and then GB /= Enclosing_Generic_Body (Parent_Base)
7573 ("parent type of& must not be outside generic body"
7575 Indic, Derived_Type);
7581 -- Ada 2005 (AI-251)
7583 if Ada_Version >= Ada_2005 and then Is_Tagged then
7585 -- "The declaration of a specific descendant of an interface type
7586 -- freezes the interface type" (RM 13.14).
7591 if Is_Non_Empty_List (Interface_List (Type_Def)) then
7592 Iface := First (Interface_List (Type_Def));
7593 while Present (Iface) loop
7594 Freeze_Before (N, Etype (Iface));
7601 -- STEP 1b : preliminary cleanup of the full view of private types
7603 -- If the type is already marked as having discriminants, then it's the
7604 -- completion of a private type or private extension and we need to
7605 -- retain the discriminants from the partial view if the current
7606 -- declaration has Discriminant_Specifications so that we can verify
7607 -- conformance. However, we must remove any existing components that
7608 -- were inherited from the parent (and attached in Copy_And_Swap)
7609 -- because the full type inherits all appropriate components anyway, and
7610 -- we do not want the partial view's components interfering.
7612 if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
7613 Discrim := First_Discriminant (Derived_Type);
7615 Last_Discrim := Discrim;
7616 Next_Discriminant (Discrim);
7617 exit when No (Discrim);
7620 Set_Last_Entity (Derived_Type, Last_Discrim);
7622 -- In all other cases wipe out the list of inherited components (even
7623 -- inherited discriminants), it will be properly rebuilt here.
7626 Set_First_Entity (Derived_Type, Empty);
7627 Set_Last_Entity (Derived_Type, Empty);
7630 -- STEP 1c: Initialize some flags for the Derived_Type
7632 -- The following flags must be initialized here so that
7633 -- Process_Discriminants can check that discriminants of tagged types do
7634 -- not have a default initial value and that access discriminants are
7635 -- only specified for limited records. For completeness, these flags are
7636 -- also initialized along with all the other flags below.
7638 -- AI-419: Limitedness is not inherited from an interface parent, so to
7639 -- be limited in that case the type must be explicitly declared as
7640 -- limited. However, task and protected interfaces are always limited.
7642 if Limited_Present (Type_Def) then
7643 Set_Is_Limited_Record (Derived_Type);
7645 elsif Is_Limited_Record (Parent_Type)
7646 or else (Present (Full_View (Parent_Type))
7647 and then Is_Limited_Record (Full_View (Parent_Type)))
7649 if not Is_Interface (Parent_Type)
7650 or else Is_Synchronized_Interface (Parent_Type)
7651 or else Is_Protected_Interface (Parent_Type)
7652 or else Is_Task_Interface (Parent_Type)
7654 Set_Is_Limited_Record (Derived_Type);
7658 -- STEP 2a: process discriminants of derived type if any
7660 Push_Scope (Derived_Type);
7662 if Discriminant_Specs then
7663 Set_Has_Unknown_Discriminants (Derived_Type, False);
7665 -- The following call initializes fields Has_Discriminants and
7666 -- Discriminant_Constraint, unless we are processing the completion
7667 -- of a private type declaration.
7669 Check_Or_Process_Discriminants (N, Derived_Type);
7671 -- For untagged types, the constraint on the Parent_Type must be
7672 -- present and is used to rename the discriminants.
7674 if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
7675 Error_Msg_N ("untagged parent must have discriminants", Indic);
7677 elsif not Is_Tagged and then not Constraint_Present then
7679 ("discriminant constraint needed for derived untagged records",
7682 -- Otherwise the parent subtype must be constrained unless we have a
7683 -- private extension.
7685 elsif not Constraint_Present
7686 and then not Private_Extension
7687 and then not Is_Constrained (Parent_Type)
7690 ("unconstrained type not allowed in this context", Indic);
7692 elsif Constraint_Present then
7693 -- The following call sets the field Corresponding_Discriminant
7694 -- for the discriminants in the Derived_Type.
7696 Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
7698 -- For untagged types all new discriminants must rename
7699 -- discriminants in the parent. For private extensions new
7700 -- discriminants cannot rename old ones (implied by [7.3(13)]).
7702 Discrim := First_Discriminant (Derived_Type);
7703 while Present (Discrim) loop
7705 and then No (Corresponding_Discriminant (Discrim))
7708 ("new discriminants must constrain old ones", Discrim);
7710 elsif Private_Extension
7711 and then Present (Corresponding_Discriminant (Discrim))
7714 ("only static constraints allowed for parent"
7715 & " discriminants in the partial view", Indic);
7719 -- If a new discriminant is used in the constraint, then its
7720 -- subtype must be statically compatible with the parent
7721 -- discriminant's subtype (3.7(15)).
7723 -- However, if the record contains an array constrained by
7724 -- the discriminant but with some different bound, the compiler
7725 -- attemps to create a smaller range for the discriminant type.
7726 -- (See exp_ch3.Adjust_Discriminants). In this case, where
7727 -- the discriminant type is a scalar type, the check must use
7728 -- the original discriminant type in the parent declaration.
7731 Corr_Disc : constant Entity_Id :=
7732 Corresponding_Discriminant (Discrim);
7733 Disc_Type : constant Entity_Id := Etype (Discrim);
7734 Corr_Type : Entity_Id;
7737 if Present (Corr_Disc) then
7738 if Is_Scalar_Type (Disc_Type) then
7740 Entity (Discriminant_Type (Parent (Corr_Disc)));
7742 Corr_Type := Etype (Corr_Disc);
7746 Subtypes_Statically_Compatible (Disc_Type, Corr_Type)
7749 ("subtype must be compatible "
7750 & "with parent discriminant",
7756 Next_Discriminant (Discrim);
7759 -- Check whether the constraints of the full view statically
7760 -- match those imposed by the parent subtype [7.3(13)].
7762 if Present (Stored_Constraint (Derived_Type)) then
7767 C1 := First_Elmt (Discs);
7768 C2 := First_Elmt (Stored_Constraint (Derived_Type));
7769 while Present (C1) and then Present (C2) loop
7771 Fully_Conformant_Expressions (Node (C1), Node (C2))
7774 ("not conformant with previous declaration",
7785 -- STEP 2b: No new discriminants, inherit discriminants if any
7788 if Private_Extension then
7789 Set_Has_Unknown_Discriminants
7791 Has_Unknown_Discriminants (Parent_Type)
7792 or else Unknown_Discriminants_Present (N));
7794 -- The partial view of the parent may have unknown discriminants,
7795 -- but if the full view has discriminants and the parent type is
7796 -- in scope they must be inherited.
7798 elsif Has_Unknown_Discriminants (Parent_Type)
7800 (not Has_Discriminants (Parent_Type)
7801 or else not In_Open_Scopes (Scope (Parent_Type)))
7803 Set_Has_Unknown_Discriminants (Derived_Type);
7806 if not Has_Unknown_Discriminants (Derived_Type)
7807 and then not Has_Unknown_Discriminants (Parent_Base)
7808 and then Has_Discriminants (Parent_Type)
7810 Inherit_Discrims := True;
7811 Set_Has_Discriminants
7812 (Derived_Type, True);
7813 Set_Discriminant_Constraint
7814 (Derived_Type, Discriminant_Constraint (Parent_Base));
7817 -- The following test is true for private types (remember
7818 -- transformation 5. is not applied to those) and in an error
7821 if Constraint_Present then
7822 Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
7825 -- For now mark a new derived type as constrained only if it has no
7826 -- discriminants. At the end of Build_Derived_Record_Type we properly
7827 -- set this flag in the case of private extensions. See comments in
7828 -- point 9. just before body of Build_Derived_Record_Type.
7832 not (Inherit_Discrims
7833 or else Has_Unknown_Discriminants (Derived_Type)));
7836 -- STEP 3: initialize fields of derived type
7838 Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
7839 Set_Stored_Constraint (Derived_Type, No_Elist);
7841 -- Ada 2005 (AI-251): Private type-declarations can implement interfaces
7842 -- but cannot be interfaces
7844 if not Private_Extension
7845 and then Ekind (Derived_Type) /= E_Private_Type
7846 and then Ekind (Derived_Type) /= E_Limited_Private_Type
7848 if Interface_Present (Type_Def) then
7849 Analyze_Interface_Declaration (Derived_Type, Type_Def);
7852 Set_Interfaces (Derived_Type, No_Elist);
7855 -- Fields inherited from the Parent_Type
7857 Set_Has_Specified_Layout
7858 (Derived_Type, Has_Specified_Layout (Parent_Type));
7859 Set_Is_Limited_Composite
7860 (Derived_Type, Is_Limited_Composite (Parent_Type));
7861 Set_Is_Private_Composite
7862 (Derived_Type, Is_Private_Composite (Parent_Type));
7864 -- Fields inherited from the Parent_Base
7866 Set_Has_Controlled_Component
7867 (Derived_Type, Has_Controlled_Component (Parent_Base));
7868 Set_Has_Non_Standard_Rep
7869 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
7870 Set_Has_Primitive_Operations
7871 (Derived_Type, Has_Primitive_Operations (Parent_Base));
7873 -- Fields inherited from the Parent_Base in the non-private case
7875 if Ekind (Derived_Type) = E_Record_Type then
7876 Set_Has_Complex_Representation
7877 (Derived_Type, Has_Complex_Representation (Parent_Base));
7880 -- Fields inherited from the Parent_Base for record types
7882 if Is_Record_Type (Derived_Type) then
7885 Parent_Full : Entity_Id;
7888 -- Ekind (Parent_Base) is not necessarily E_Record_Type since
7889 -- Parent_Base can be a private type or private extension. Go
7890 -- to the full view here to get the E_Record_Type specific flags.
7892 if Present (Full_View (Parent_Base)) then
7893 Parent_Full := Full_View (Parent_Base);
7895 Parent_Full := Parent_Base;
7898 Set_OK_To_Reorder_Components
7899 (Derived_Type, OK_To_Reorder_Components (Parent_Full));
7903 -- Set fields for private derived types
7905 if Is_Private_Type (Derived_Type) then
7906 Set_Depends_On_Private (Derived_Type, True);
7907 Set_Private_Dependents (Derived_Type, New_Elmt_List);
7909 -- Inherit fields from non private record types. If this is the
7910 -- completion of a derivation from a private type, the parent itself
7911 -- is private, and the attributes come from its full view, which must
7915 if Is_Private_Type (Parent_Base)
7916 and then not Is_Record_Type (Parent_Base)
7918 Set_Component_Alignment
7919 (Derived_Type, Component_Alignment (Full_View (Parent_Base)));
7921 (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
7923 Set_Component_Alignment
7924 (Derived_Type, Component_Alignment (Parent_Base));
7926 (Derived_Type, C_Pass_By_Copy (Parent_Base));
7930 -- Set fields for tagged types
7933 Set_Direct_Primitive_Operations (Derived_Type, New_Elmt_List);
7935 -- All tagged types defined in Ada.Finalization are controlled
7937 if Chars (Scope (Derived_Type)) = Name_Finalization
7938 and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
7939 and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
7941 Set_Is_Controlled (Derived_Type);
7943 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
7946 -- Minor optimization: there is no need to generate the class-wide
7947 -- entity associated with an underlying record view.
7949 if not Is_Underlying_Record_View (Derived_Type) then
7950 Make_Class_Wide_Type (Derived_Type);
7953 Set_Is_Abstract_Type (Derived_Type, Abstract_Present (Type_Def));
7955 if Has_Discriminants (Derived_Type)
7956 and then Constraint_Present
7958 Set_Stored_Constraint
7959 (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
7962 if Ada_Version >= Ada_2005 then
7964 Ifaces_List : Elist_Id;
7967 -- Checks rules 3.9.4 (13/2 and 14/2)
7969 if Comes_From_Source (Derived_Type)
7970 and then not Is_Private_Type (Derived_Type)
7971 and then Is_Interface (Parent_Type)
7972 and then not Is_Interface (Derived_Type)
7974 if Is_Task_Interface (Parent_Type) then
7976 ("(Ada 2005) task type required (RM 3.9.4 (13.2))",
7979 elsif Is_Protected_Interface (Parent_Type) then
7981 ("(Ada 2005) protected type required (RM 3.9.4 (14.2))",
7986 -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
7988 Check_Interfaces (N, Type_Def);
7990 -- Ada 2005 (AI-251): Collect the list of progenitors that are
7991 -- not already in the parents.
7995 Ifaces_List => Ifaces_List,
7996 Exclude_Parents => True);
7998 Set_Interfaces (Derived_Type, Ifaces_List);
8000 -- If the derived type is the anonymous type created for
8001 -- a declaration whose parent has a constraint, propagate
8002 -- the interface list to the source type. This must be done
8003 -- prior to the completion of the analysis of the source type
8004 -- because the components in the extension may contain current
8005 -- instances whose legality depends on some ancestor.
8007 if Is_Itype (Derived_Type) then
8009 Def : constant Node_Id :=
8010 Associated_Node_For_Itype (Derived_Type);
8013 and then Nkind (Def) = N_Full_Type_Declaration
8016 (Defining_Identifier (Def), Ifaces_List);
8024 Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
8025 Set_Has_Non_Standard_Rep
8026 (Derived_Type, Has_Non_Standard_Rep (Parent_Base));
8029 -- STEP 4: Inherit components from the parent base and constrain them.
8030 -- Apply the second transformation described in point 6. above.
8032 if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
8033 or else not Has_Discriminants (Parent_Type)
8034 or else not Is_Constrained (Parent_Type)
8038 Constrs := Discriminant_Constraint (Parent_Type);
8043 (N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
8045 -- STEP 5a: Copy the parent record declaration for untagged types
8047 if not Is_Tagged then
8049 -- Discriminant_Constraint (Derived_Type) has been properly
8050 -- constructed. Save it and temporarily set it to Empty because we
8051 -- do not want the call to New_Copy_Tree below to mess this list.
8053 if Has_Discriminants (Derived_Type) then
8054 Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
8055 Set_Discriminant_Constraint (Derived_Type, No_Elist);
8057 Save_Discr_Constr := No_Elist;
8060 -- Save the Etype field of Derived_Type. It is correctly set now,
8061 -- but the call to New_Copy tree may remap it to point to itself,
8062 -- which is not what we want. Ditto for the Next_Entity field.
8064 Save_Etype := Etype (Derived_Type);
8065 Save_Next_Entity := Next_Entity (Derived_Type);
8067 -- Assoc_List maps all stored discriminants in the Parent_Base to
8068 -- stored discriminants in the Derived_Type. It is fundamental that
8069 -- no types or itypes with discriminants other than the stored
8070 -- discriminants appear in the entities declared inside
8071 -- Derived_Type, since the back end cannot deal with it.
8075 (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
8077 -- Restore the fields saved prior to the New_Copy_Tree call
8078 -- and compute the stored constraint.
8080 Set_Etype (Derived_Type, Save_Etype);
8081 Set_Next_Entity (Derived_Type, Save_Next_Entity);
8083 if Has_Discriminants (Derived_Type) then
8084 Set_Discriminant_Constraint
8085 (Derived_Type, Save_Discr_Constr);
8086 Set_Stored_Constraint
8087 (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
8088 Replace_Components (Derived_Type, New_Decl);
8089 Set_Has_Implicit_Dereference
8090 (Derived_Type, Has_Implicit_Dereference (Parent_Type));
8093 -- Insert the new derived type declaration
8095 Rewrite (N, New_Decl);
8097 -- STEP 5b: Complete the processing for record extensions in generics
8099 -- There is no completion for record extensions declared in the
8100 -- parameter part of a generic, so we need to complete processing for
8101 -- these generic record extensions here. The Record_Type_Definition call
8102 -- will change the Ekind of the components from E_Void to E_Component.
8104 elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
8105 Record_Type_Definition (Empty, Derived_Type);
8107 -- STEP 5c: Process the record extension for non private tagged types
8109 elsif not Private_Extension then
8111 -- Add the _parent field in the derived type
8113 Expand_Record_Extension (Derived_Type, Type_Def);
8115 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
8116 -- implemented interfaces if we are in expansion mode
8119 and then Has_Interfaces (Derived_Type)
8121 Add_Interface_Tag_Components (N, Derived_Type);
8124 -- Analyze the record extension
8126 Record_Type_Definition
8127 (Record_Extension_Part (Type_Def), Derived_Type);
8132 -- Nothing else to do if there is an error in the derivation.
8133 -- An unusual case: the full view may be derived from a type in an
8134 -- instance, when the partial view was used illegally as an actual
8135 -- in that instance, leading to a circular definition.
8137 if Etype (Derived_Type) = Any_Type
8138 or else Etype (Parent_Type) = Derived_Type
8143 -- Set delayed freeze and then derive subprograms, we need to do
8144 -- this in this order so that derived subprograms inherit the
8145 -- derived freeze if necessary.
8147 Set_Has_Delayed_Freeze (Derived_Type);
8149 if Derive_Subps then
8150 Derive_Subprograms (Parent_Type, Derived_Type);
8153 -- If we have a private extension which defines a constrained derived
8154 -- type mark as constrained here after we have derived subprograms. See
8155 -- comment on point 9. just above the body of Build_Derived_Record_Type.
8157 if Private_Extension and then Inherit_Discrims then
8158 if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
8159 Set_Is_Constrained (Derived_Type, True);
8160 Set_Discriminant_Constraint (Derived_Type, Discs);
8162 elsif Is_Constrained (Parent_Type) then
8164 (Derived_Type, True);
8165 Set_Discriminant_Constraint
8166 (Derived_Type, Discriminant_Constraint (Parent_Type));
8170 -- Update the class-wide type, which shares the now-completed entity
8171 -- list with its specific type. In case of underlying record views,
8172 -- we do not generate the corresponding class wide entity.
8175 and then not Is_Underlying_Record_View (Derived_Type)
8178 (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
8180 (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
8183 Check_Function_Writable_Actuals (N);
8184 end Build_Derived_Record_Type;
8186 ------------------------
8187 -- Build_Derived_Type --
8188 ------------------------
8190 procedure Build_Derived_Type
8192 Parent_Type : Entity_Id;
8193 Derived_Type : Entity_Id;
8194 Is_Completion : Boolean;
8195 Derive_Subps : Boolean := True)
8197 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
8200 -- Set common attributes
8202 Set_Scope (Derived_Type, Current_Scope);
8204 Set_Ekind (Derived_Type, Ekind (Parent_Base));
8205 Set_Etype (Derived_Type, Parent_Base);
8206 Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
8208 Set_Size_Info (Derived_Type, Parent_Type);
8209 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
8210 Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
8211 Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type));
8213 -- If the parent type is a private subtype, the convention on the base
8214 -- type may be set in the private part, and not propagated to the
8215 -- subtype until later, so we obtain the convention from the base type.
8217 Set_Convention (Derived_Type, Convention (Parent_Base));
8219 -- Propagate invariant information. The new type has invariants if
8220 -- they are inherited from the parent type, and these invariants can
8221 -- be further inherited, so both flags are set.
8223 -- We similarly inherit predicates
8225 if Has_Predicates (Parent_Type) then
8226 Set_Has_Predicates (Derived_Type);
8229 -- The derived type inherits the representation clauses of the parent.
8230 -- However, for a private type that is completed by a derivation, there
8231 -- may be operation attributes that have been specified already (stream
8232 -- attributes and External_Tag) and those must be provided. Finally,
8233 -- if the partial view is a private extension, the representation items
8234 -- of the parent have been inherited already, and should not be chained
8235 -- twice to the derived type.
8237 if Is_Tagged_Type (Parent_Type)
8238 and then Present (First_Rep_Item (Derived_Type))
8240 -- The existing items are either operational items or items inherited
8241 -- from a private extension declaration.
8245 -- Used to iterate over representation items of the derived type
8248 -- Last representation item of the (non-empty) representation
8249 -- item list of the derived type.
8251 Found : Boolean := False;
8254 Rep := First_Rep_Item (Derived_Type);
8256 while Present (Rep) loop
8257 if Rep = First_Rep_Item (Parent_Type) then
8262 Rep := Next_Rep_Item (Rep);
8264 if Present (Rep) then
8270 -- Here if we either encountered the parent type's first rep
8271 -- item on the derived type's rep item list (in which case
8272 -- Found is True, and we have nothing else to do), or if we
8273 -- reached the last rep item of the derived type, which is
8274 -- Last_Rep, in which case we further chain the parent type's
8275 -- rep items to those of the derived type.
8278 Set_Next_Rep_Item (Last_Rep, First_Rep_Item (Parent_Type));
8283 Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
8286 -- If the parent type has delayed rep aspects, then mark the derived
8287 -- type as possibly inheriting a delayed rep aspect.
8289 if Has_Delayed_Rep_Aspects (Parent_Type) then
8290 Set_May_Inherit_Delayed_Rep_Aspects (Derived_Type);
8293 -- Type dependent processing
8295 case Ekind (Parent_Type) is
8296 when Numeric_Kind =>
8297 Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
8300 Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
8304 | Class_Wide_Kind =>
8305 Build_Derived_Record_Type
8306 (N, Parent_Type, Derived_Type, Derive_Subps);
8309 when Enumeration_Kind =>
8310 Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
8313 Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
8315 when Incomplete_Or_Private_Kind =>
8316 Build_Derived_Private_Type
8317 (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
8319 -- For discriminated types, the derivation includes deriving
8320 -- primitive operations. For others it is done below.
8322 if Is_Tagged_Type (Parent_Type)
8323 or else Has_Discriminants (Parent_Type)
8324 or else (Present (Full_View (Parent_Type))
8325 and then Has_Discriminants (Full_View (Parent_Type)))
8330 when Concurrent_Kind =>
8331 Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
8334 raise Program_Error;
8337 -- Nothing more to do if some error occurred
8339 if Etype (Derived_Type) = Any_Type then
8343 -- Set delayed freeze and then derive subprograms, we need to do this
8344 -- in this order so that derived subprograms inherit the derived freeze
8347 Set_Has_Delayed_Freeze (Derived_Type);
8349 if Derive_Subps then
8350 Derive_Subprograms (Parent_Type, Derived_Type);
8353 Set_Has_Primitive_Operations
8354 (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
8355 end Build_Derived_Type;
8357 -----------------------
8358 -- Build_Discriminal --
8359 -----------------------
8361 procedure Build_Discriminal (Discrim : Entity_Id) is
8362 D_Minal : Entity_Id;
8363 CR_Disc : Entity_Id;
8366 -- A discriminal has the same name as the discriminant
8368 D_Minal := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
8370 Set_Ekind (D_Minal, E_In_Parameter);
8371 Set_Mechanism (D_Minal, Default_Mechanism);
8372 Set_Etype (D_Minal, Etype (Discrim));
8373 Set_Scope (D_Minal, Current_Scope);
8375 Set_Discriminal (Discrim, D_Minal);
8376 Set_Discriminal_Link (D_Minal, Discrim);
8378 -- For task types, build at once the discriminants of the corresponding
8379 -- record, which are needed if discriminants are used in entry defaults
8380 -- and in family bounds.
8382 if Is_Concurrent_Type (Current_Scope)
8383 or else Is_Limited_Type (Current_Scope)
8385 CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
8387 Set_Ekind (CR_Disc, E_In_Parameter);
8388 Set_Mechanism (CR_Disc, Default_Mechanism);
8389 Set_Etype (CR_Disc, Etype (Discrim));
8390 Set_Scope (CR_Disc, Current_Scope);
8391 Set_Discriminal_Link (CR_Disc, Discrim);
8392 Set_CR_Discriminant (Discrim, CR_Disc);
8394 end Build_Discriminal;
8396 ------------------------------------
8397 -- Build_Discriminant_Constraints --
8398 ------------------------------------
8400 function Build_Discriminant_Constraints
8403 Derived_Def : Boolean := False) return Elist_Id
8405 C : constant Node_Id := Constraint (Def);
8406 Nb_Discr : constant Nat := Number_Discriminants (T);
8408 Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
8409 -- Saves the expression corresponding to a given discriminant in T
8411 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
8412 -- Return the Position number within array Discr_Expr of a discriminant
8413 -- D within the discriminant list of the discriminated type T.
8415 procedure Process_Discriminant_Expression
8418 -- If this is a discriminant constraint on a partial view, do not
8419 -- generate an overflow check on the discriminant expression. The check
8420 -- will be generated when constraining the full view. Otherwise the
8421 -- backend creates duplicate symbols for the temporaries corresponding
8422 -- to the expressions to be checked, causing spurious assembler errors.
8428 function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
8432 Disc := First_Discriminant (T);
8433 for J in Discr_Expr'Range loop
8438 Next_Discriminant (Disc);
8441 -- Note: Since this function is called on discriminants that are
8442 -- known to belong to the discriminated type, falling through the
8443 -- loop with no match signals an internal compiler error.
8445 raise Program_Error;
8448 -------------------------------------
8449 -- Process_Discriminant_Expression --
8450 -------------------------------------
8452 procedure Process_Discriminant_Expression
8456 BDT : constant Entity_Id := Base_Type (Etype (D));
8459 -- If this is a discriminant constraint on a partial view, do
8460 -- not generate an overflow on the discriminant expression. The
8461 -- check will be generated when constraining the full view.
8463 if Is_Private_Type (T)
8464 and then Present (Full_View (T))
8466 Analyze_And_Resolve (Expr, BDT, Suppress => Overflow_Check);
8468 Analyze_And_Resolve (Expr, BDT);
8470 end Process_Discriminant_Expression;
8472 -- Declarations local to Build_Discriminant_Constraints
8476 Elist : constant Elist_Id := New_Elmt_List;
8484 Discrim_Present : Boolean := False;
8486 -- Start of processing for Build_Discriminant_Constraints
8489 -- The following loop will process positional associations only.
8490 -- For a positional association, the (single) discriminant is
8491 -- implicitly specified by position, in textual order (RM 3.7.2).
8493 Discr := First_Discriminant (T);
8494 Constr := First (Constraints (C));
8495 for D in Discr_Expr'Range loop
8496 exit when Nkind (Constr) = N_Discriminant_Association;
8499 Error_Msg_N ("too few discriminants given in constraint", C);
8500 return New_Elmt_List;
8502 elsif Nkind (Constr) = N_Range
8503 or else (Nkind (Constr) = N_Attribute_Reference
8505 Attribute_Name (Constr) = Name_Range)
8508 ("a range is not a valid discriminant constraint", Constr);
8509 Discr_Expr (D) := Error;
8512 Process_Discriminant_Expression (Constr, Discr);
8513 Discr_Expr (D) := Constr;
8516 Next_Discriminant (Discr);
8520 if No (Discr) and then Present (Constr) then
8521 Error_Msg_N ("too many discriminants given in constraint", Constr);
8522 return New_Elmt_List;
8525 -- Named associations can be given in any order, but if both positional
8526 -- and named associations are used in the same discriminant constraint,
8527 -- then positional associations must occur first, at their normal
8528 -- position. Hence once a named association is used, the rest of the
8529 -- discriminant constraint must use only named associations.
8531 while Present (Constr) loop
8533 -- Positional association forbidden after a named association
8535 if Nkind (Constr) /= N_Discriminant_Association then
8536 Error_Msg_N ("positional association follows named one", Constr);
8537 return New_Elmt_List;
8539 -- Otherwise it is a named association
8542 -- E records the type of the discriminants in the named
8543 -- association. All the discriminants specified in the same name
8544 -- association must have the same type.
8548 -- Search the list of discriminants in T to see if the simple name
8549 -- given in the constraint matches any of them.
8551 Id := First (Selector_Names (Constr));
8552 while Present (Id) loop
8555 -- If Original_Discriminant is present, we are processing a
8556 -- generic instantiation and this is an instance node. We need
8557 -- to find the name of the corresponding discriminant in the
8558 -- actual record type T and not the name of the discriminant in
8559 -- the generic formal. Example:
8562 -- type G (D : int) is private;
8564 -- subtype W is G (D => 1);
8566 -- type Rec (X : int) is record ... end record;
8567 -- package Q is new P (G => Rec);
8569 -- At the point of the instantiation, formal type G is Rec
8570 -- and therefore when reanalyzing "subtype W is G (D => 1);"
8571 -- which really looks like "subtype W is Rec (D => 1);" at
8572 -- the point of instantiation, we want to find the discriminant
8573 -- that corresponds to D in Rec, i.e. X.
8575 if Present (Original_Discriminant (Id))
8576 and then In_Instance
8578 Discr := Find_Corresponding_Discriminant (Id, T);
8582 Discr := First_Discriminant (T);
8583 while Present (Discr) loop
8584 if Chars (Discr) = Chars (Id) then
8589 Next_Discriminant (Discr);
8593 Error_Msg_N ("& does not match any discriminant", Id);
8594 return New_Elmt_List;
8596 -- If the parent type is a generic formal, preserve the
8597 -- name of the discriminant for subsequent instances.
8598 -- see comment at the beginning of this if statement.
8600 elsif Is_Generic_Type (Root_Type (T)) then
8601 Set_Original_Discriminant (Id, Discr);
8605 Position := Pos_Of_Discr (T, Discr);
8607 if Present (Discr_Expr (Position)) then
8608 Error_Msg_N ("duplicate constraint for discriminant&", Id);
8611 -- Each discriminant specified in the same named association
8612 -- must be associated with a separate copy of the
8613 -- corresponding expression.
8615 if Present (Next (Id)) then
8616 Expr := New_Copy_Tree (Expression (Constr));
8617 Set_Parent (Expr, Parent (Expression (Constr)));
8619 Expr := Expression (Constr);
8622 Discr_Expr (Position) := Expr;
8623 Process_Discriminant_Expression (Expr, Discr);
8626 -- A discriminant association with more than one discriminant
8627 -- name is only allowed if the named discriminants are all of
8628 -- the same type (RM 3.7.1(8)).
8631 E := Base_Type (Etype (Discr));
8633 elsif Base_Type (Etype (Discr)) /= E then
8635 ("all discriminants in an association " &
8636 "must have the same type", Id);
8646 -- A discriminant constraint must provide exactly one value for each
8647 -- discriminant of the type (RM 3.7.1(8)).
8649 for J in Discr_Expr'Range loop
8650 if No (Discr_Expr (J)) then
8651 Error_Msg_N ("too few discriminants given in constraint", C);
8652 return New_Elmt_List;
8656 -- Determine if there are discriminant expressions in the constraint
8658 for J in Discr_Expr'Range loop
8659 if Denotes_Discriminant
8660 (Discr_Expr (J), Check_Concurrent => True)
8662 Discrim_Present := True;
8666 -- Build an element list consisting of the expressions given in the
8667 -- discriminant constraint and apply the appropriate checks. The list
8668 -- is constructed after resolving any named discriminant associations
8669 -- and therefore the expressions appear in the textual order of the
8672 Discr := First_Discriminant (T);
8673 for J in Discr_Expr'Range loop
8674 if Discr_Expr (J) /= Error then
8675 Append_Elmt (Discr_Expr (J), Elist);
8677 -- If any of the discriminant constraints is given by a
8678 -- discriminant and we are in a derived type declaration we
8679 -- have a discriminant renaming. Establish link between new
8680 -- and old discriminant.
8682 if Denotes_Discriminant (Discr_Expr (J)) then
8684 Set_Corresponding_Discriminant
8685 (Entity (Discr_Expr (J)), Discr);
8688 -- Force the evaluation of non-discriminant expressions.
8689 -- If we have found a discriminant in the constraint 3.4(26)
8690 -- and 3.8(18) demand that no range checks are performed are
8691 -- after evaluation. If the constraint is for a component
8692 -- definition that has a per-object constraint, expressions are
8693 -- evaluated but not checked either. In all other cases perform
8697 if Discrim_Present then
8700 elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
8702 Has_Per_Object_Constraint
8703 (Defining_Identifier (Parent (Parent (Def))))
8707 elsif Is_Access_Type (Etype (Discr)) then
8708 Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
8711 Apply_Range_Check (Discr_Expr (J), Etype (Discr));
8714 Force_Evaluation (Discr_Expr (J));
8717 -- Check that the designated type of an access discriminant's
8718 -- expression is not a class-wide type unless the discriminant's
8719 -- designated type is also class-wide.
8721 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
8722 and then not Is_Class_Wide_Type
8723 (Designated_Type (Etype (Discr)))
8724 and then Etype (Discr_Expr (J)) /= Any_Type
8725 and then Is_Class_Wide_Type
8726 (Designated_Type (Etype (Discr_Expr (J))))
8728 Wrong_Type (Discr_Expr (J), Etype (Discr));
8730 elsif Is_Access_Type (Etype (Discr))
8731 and then not Is_Access_Constant (Etype (Discr))
8732 and then Is_Access_Type (Etype (Discr_Expr (J)))
8733 and then Is_Access_Constant (Etype (Discr_Expr (J)))
8736 ("constraint for discriminant& must be access to variable",
8741 Next_Discriminant (Discr);
8745 end Build_Discriminant_Constraints;
8747 ---------------------------------
8748 -- Build_Discriminated_Subtype --
8749 ---------------------------------
8751 procedure Build_Discriminated_Subtype
8755 Related_Nod : Node_Id;
8756 For_Access : Boolean := False)
8758 Has_Discrs : constant Boolean := Has_Discriminants (T);
8759 Constrained : constant Boolean :=
8761 and then not Is_Empty_Elmt_List (Elist)
8762 and then not Is_Class_Wide_Type (T))
8763 or else Is_Constrained (T);
8766 if Ekind (T) = E_Record_Type then
8768 Set_Ekind (Def_Id, E_Private_Subtype);
8769 Set_Is_For_Access_Subtype (Def_Id, True);
8771 Set_Ekind (Def_Id, E_Record_Subtype);
8774 -- Inherit preelaboration flag from base, for types for which it
8775 -- may have been set: records, private types, protected types.
8777 Set_Known_To_Have_Preelab_Init
8778 (Def_Id, Known_To_Have_Preelab_Init (T));
8780 elsif Ekind (T) = E_Task_Type then
8781 Set_Ekind (Def_Id, E_Task_Subtype);
8783 elsif Ekind (T) = E_Protected_Type then
8784 Set_Ekind (Def_Id, E_Protected_Subtype);
8785 Set_Known_To_Have_Preelab_Init
8786 (Def_Id, Known_To_Have_Preelab_Init (T));
8788 elsif Is_Private_Type (T) then
8789 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
8790 Set_Known_To_Have_Preelab_Init
8791 (Def_Id, Known_To_Have_Preelab_Init (T));
8793 -- Private subtypes may have private dependents
8795 Set_Private_Dependents (Def_Id, New_Elmt_List);
8797 elsif Is_Class_Wide_Type (T) then
8798 Set_Ekind (Def_Id, E_Class_Wide_Subtype);
8801 -- Incomplete type. Attach subtype to list of dependents, to be
8802 -- completed with full view of parent type, unless is it the
8803 -- designated subtype of a record component within an init_proc.
8804 -- This last case arises for a component of an access type whose
8805 -- designated type is incomplete (e.g. a Taft Amendment type).
8806 -- The designated subtype is within an inner scope, and needs no
8807 -- elaboration, because only the access type is needed in the
8808 -- initialization procedure.
8810 Set_Ekind (Def_Id, Ekind (T));
8812 if For_Access and then Within_Init_Proc then
8815 Append_Elmt (Def_Id, Private_Dependents (T));
8819 Set_Etype (Def_Id, T);
8820 Init_Size_Align (Def_Id);
8821 Set_Has_Discriminants (Def_Id, Has_Discrs);
8822 Set_Is_Constrained (Def_Id, Constrained);
8824 Set_First_Entity (Def_Id, First_Entity (T));
8825 Set_Last_Entity (Def_Id, Last_Entity (T));
8826 Set_Has_Implicit_Dereference
8827 (Def_Id, Has_Implicit_Dereference (T));
8829 -- If the subtype is the completion of a private declaration, there may
8830 -- have been representation clauses for the partial view, and they must
8831 -- be preserved. Build_Derived_Type chains the inherited clauses with
8832 -- the ones appearing on the extension. If this comes from a subtype
8833 -- declaration, all clauses are inherited.
8835 if No (First_Rep_Item (Def_Id)) then
8836 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
8839 if Is_Tagged_Type (T) then
8840 Set_Is_Tagged_Type (Def_Id);
8841 Make_Class_Wide_Type (Def_Id);
8844 Set_Stored_Constraint (Def_Id, No_Elist);
8847 Set_Discriminant_Constraint (Def_Id, Elist);
8848 Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
8851 if Is_Tagged_Type (T) then
8853 -- Ada 2005 (AI-251): In case of concurrent types we inherit the
8854 -- concurrent record type (which has the list of primitive
8857 if Ada_Version >= Ada_2005
8858 and then Is_Concurrent_Type (T)
8860 Set_Corresponding_Record_Type (Def_Id,
8861 Corresponding_Record_Type (T));
8863 Set_Direct_Primitive_Operations (Def_Id,
8864 Direct_Primitive_Operations (T));
8867 Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (T));
8870 -- Subtypes introduced by component declarations do not need to be
8871 -- marked as delayed, and do not get freeze nodes, because the semantics
8872 -- verifies that the parents of the subtypes are frozen before the
8873 -- enclosing record is frozen.
8875 if not Is_Type (Scope (Def_Id)) then
8876 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
8878 if Is_Private_Type (T)
8879 and then Present (Full_View (T))
8881 Conditional_Delay (Def_Id, Full_View (T));
8883 Conditional_Delay (Def_Id, T);
8887 if Is_Record_Type (T) then
8888 Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
8891 and then not Is_Empty_Elmt_List (Elist)
8892 and then not For_Access
8894 Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
8895 elsif not For_Access then
8896 Set_Cloned_Subtype (Def_Id, T);
8899 end Build_Discriminated_Subtype;
8901 ---------------------------
8902 -- Build_Itype_Reference --
8903 ---------------------------
8905 procedure Build_Itype_Reference
8909 IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod));
8912 -- Itype references are only created for use by the back-end
8914 if Inside_A_Generic then
8917 Set_Itype (IR, Ityp);
8918 Insert_After (Nod, IR);
8920 end Build_Itype_Reference;
8922 ------------------------
8923 -- Build_Scalar_Bound --
8924 ------------------------
8926 function Build_Scalar_Bound
8929 Der_T : Entity_Id) return Node_Id
8931 New_Bound : Entity_Id;
8934 -- Note: not clear why this is needed, how can the original bound
8935 -- be unanalyzed at this point? and if it is, what business do we
8936 -- have messing around with it? and why is the base type of the
8937 -- parent type the right type for the resolution. It probably is
8938 -- not! It is OK for the new bound we are creating, but not for
8939 -- the old one??? Still if it never happens, no problem!
8941 Analyze_And_Resolve (Bound, Base_Type (Par_T));
8943 if Nkind_In (Bound, N_Integer_Literal, N_Real_Literal) then
8944 New_Bound := New_Copy (Bound);
8945 Set_Etype (New_Bound, Der_T);
8946 Set_Analyzed (New_Bound);
8948 elsif Is_Entity_Name (Bound) then
8949 New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
8951 -- The following is almost certainly wrong. What business do we have
8952 -- relocating a node (Bound) that is presumably still attached to
8953 -- the tree elsewhere???
8956 New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
8959 Set_Etype (New_Bound, Der_T);
8961 end Build_Scalar_Bound;
8963 --------------------------------
8964 -- Build_Underlying_Full_View --
8965 --------------------------------
8967 procedure Build_Underlying_Full_View
8972 Loc : constant Source_Ptr := Sloc (N);
8973 Subt : constant Entity_Id :=
8974 Make_Defining_Identifier
8975 (Loc, New_External_Name (Chars (Typ), 'S'));
8982 procedure Set_Discriminant_Name (Id : Node_Id);
8983 -- If the derived type has discriminants, they may rename discriminants
8984 -- of the parent. When building the full view of the parent, we need to
8985 -- recover the names of the original discriminants if the constraint is
8986 -- given by named associations.
8988 ---------------------------
8989 -- Set_Discriminant_Name --
8990 ---------------------------
8992 procedure Set_Discriminant_Name (Id : Node_Id) is
8996 Set_Original_Discriminant (Id, Empty);
8998 if Has_Discriminants (Typ) then
8999 Disc := First_Discriminant (Typ);
9000 while Present (Disc) loop
9001 if Chars (Disc) = Chars (Id)
9002 and then Present (Corresponding_Discriminant (Disc))
9004 Set_Chars (Id, Chars (Corresponding_Discriminant (Disc)));
9006 Next_Discriminant (Disc);
9009 end Set_Discriminant_Name;
9011 -- Start of processing for Build_Underlying_Full_View
9014 if Nkind (N) = N_Full_Type_Declaration then
9015 Constr := Constraint (Subtype_Indication (Type_Definition (N)));
9017 elsif Nkind (N) = N_Subtype_Declaration then
9018 Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
9020 elsif Nkind (N) = N_Component_Declaration then
9023 (Constraint (Subtype_Indication (Component_Definition (N))));
9026 raise Program_Error;
9029 C := First (Constraints (Constr));
9030 while Present (C) loop
9031 if Nkind (C) = N_Discriminant_Association then
9032 Id := First (Selector_Names (C));
9033 while Present (Id) loop
9034 Set_Discriminant_Name (Id);
9043 Make_Subtype_Declaration (Loc,
9044 Defining_Identifier => Subt,
9045 Subtype_Indication =>
9046 Make_Subtype_Indication (Loc,
9047 Subtype_Mark => New_Reference_To (Par, Loc),
9048 Constraint => New_Copy_Tree (Constr)));
9050 -- If this is a component subtype for an outer itype, it is not
9051 -- a list member, so simply set the parent link for analysis: if
9052 -- the enclosing type does not need to be in a declarative list,
9053 -- neither do the components.
9055 if Is_List_Member (N)
9056 and then Nkind (N) /= N_Component_Declaration
9058 Insert_Before (N, Indic);
9060 Set_Parent (Indic, Parent (N));
9064 Set_Underlying_Full_View (Typ, Full_View (Subt));
9065 end Build_Underlying_Full_View;
9067 -------------------------------
9068 -- Check_Abstract_Overriding --
9069 -------------------------------
9071 procedure Check_Abstract_Overriding (T : Entity_Id) is
9072 Alias_Subp : Entity_Id;
9078 procedure Check_Pragma_Implemented (Subp : Entity_Id);
9079 -- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine
9080 -- which has pragma Implemented already set. Check whether Subp's entity
9081 -- kind conforms to the implementation kind of the overridden routine.
9083 procedure Check_Pragma_Implemented
9085 Iface_Subp : Entity_Id);
9086 -- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine
9087 -- Iface_Subp and both entities have pragma Implemented already set on
9088 -- them. Check whether the two implementation kinds are conforming.
9090 procedure Inherit_Pragma_Implemented
9092 Iface_Subp : Entity_Id);
9093 -- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface
9094 -- subprogram Iface_Subp which has been marked by pragma Implemented.
9095 -- Propagate the implementation kind of Iface_Subp to Subp.
9097 ------------------------------
9098 -- Check_Pragma_Implemented --
9099 ------------------------------
9101 procedure Check_Pragma_Implemented (Subp : Entity_Id) is
9102 Iface_Alias : constant Entity_Id := Interface_Alias (Subp);
9103 Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias);
9104 Subp_Alias : constant Entity_Id := Alias (Subp);
9105 Contr_Typ : Entity_Id;
9106 Impl_Subp : Entity_Id;
9109 -- Subp must have an alias since it is a hidden entity used to link
9110 -- an interface subprogram to its overriding counterpart.
9112 pragma Assert (Present (Subp_Alias));
9114 -- Handle aliases to synchronized wrappers
9116 Impl_Subp := Subp_Alias;
9118 if Is_Primitive_Wrapper (Impl_Subp) then
9119 Impl_Subp := Wrapped_Entity (Impl_Subp);
9122 -- Extract the type of the controlling formal
9124 Contr_Typ := Etype (First_Formal (Subp_Alias));
9126 if Is_Concurrent_Record_Type (Contr_Typ) then
9127 Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ);
9130 -- An interface subprogram whose implementation kind is By_Entry must
9131 -- be implemented by an entry.
9133 if Impl_Kind = Name_By_Entry
9134 and then Ekind (Impl_Subp) /= E_Entry
9136 Error_Msg_Node_2 := Iface_Alias;
9138 ("type & must implement abstract subprogram & with an entry",
9139 Subp_Alias, Contr_Typ);
9141 elsif Impl_Kind = Name_By_Protected_Procedure then
9143 -- An interface subprogram whose implementation kind is By_
9144 -- Protected_Procedure cannot be implemented by a primitive
9145 -- procedure of a task type.
9147 if Ekind (Contr_Typ) /= E_Protected_Type then
9148 Error_Msg_Node_2 := Contr_Typ;
9150 ("interface subprogram & cannot be implemented by a " &
9151 "primitive procedure of task type &", Subp_Alias,
9154 -- An interface subprogram whose implementation kind is By_
9155 -- Protected_Procedure must be implemented by a procedure.
9157 elsif Ekind (Impl_Subp) /= E_Procedure then
9158 Error_Msg_Node_2 := Iface_Alias;
9160 ("type & must implement abstract subprogram & with a " &
9161 "procedure", Subp_Alias, Contr_Typ);
9164 end Check_Pragma_Implemented;
9166 ------------------------------
9167 -- Check_Pragma_Implemented --
9168 ------------------------------
9170 procedure Check_Pragma_Implemented
9172 Iface_Subp : Entity_Id)
9174 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
9175 Subp_Kind : constant Name_Id := Implementation_Kind (Subp);
9178 -- Ada 2012 (AI05-0030): The implementation kinds of an overridden
9179 -- and overriding subprogram are different. In general this is an
9180 -- error except when the implementation kind of the overridden
9181 -- subprograms is By_Any or Optional.
9183 if Iface_Kind /= Subp_Kind
9184 and then Iface_Kind /= Name_By_Any
9185 and then Iface_Kind /= Name_Optional
9187 if Iface_Kind = Name_By_Entry then
9189 ("incompatible implementation kind, overridden subprogram " &
9190 "is marked By_Entry", Subp);
9193 ("incompatible implementation kind, overridden subprogram " &
9194 "is marked By_Protected_Procedure", Subp);
9197 end Check_Pragma_Implemented;
9199 --------------------------------
9200 -- Inherit_Pragma_Implemented --
9201 --------------------------------
9203 procedure Inherit_Pragma_Implemented
9205 Iface_Subp : Entity_Id)
9207 Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
9208 Loc : constant Source_Ptr := Sloc (Subp);
9209 Impl_Prag : Node_Id;
9212 -- Since the implementation kind is stored as a representation item
9213 -- rather than a flag, create a pragma node.
9217 Chars => Name_Implemented,
9218 Pragma_Argument_Associations => New_List (
9219 Make_Pragma_Argument_Association (Loc,
9220 Expression => New_Reference_To (Subp, Loc)),
9222 Make_Pragma_Argument_Association (Loc,
9223 Expression => Make_Identifier (Loc, Iface_Kind))));
9225 -- The pragma doesn't need to be analyzed because it is internally
9226 -- built. It is safe to directly register it as a rep item since we
9227 -- are only interested in the characters of the implementation kind.
9229 Record_Rep_Item (Subp, Impl_Prag);
9230 end Inherit_Pragma_Implemented;
9232 -- Start of processing for Check_Abstract_Overriding
9235 Op_List := Primitive_Operations (T);
9237 -- Loop to check primitive operations
9239 Elmt := First_Elmt (Op_List);
9240 while Present (Elmt) loop
9241 Subp := Node (Elmt);
9242 Alias_Subp := Alias (Subp);
9244 -- Inherited subprograms are identified by the fact that they do not
9245 -- come from source, and the associated source location is the
9246 -- location of the first subtype of the derived type.
9248 -- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for
9249 -- subprograms that "require overriding".
9251 -- Special exception, do not complain about failure to override the
9252 -- stream routines _Input and _Output, as well as the primitive
9253 -- operations used in dispatching selects since we always provide
9254 -- automatic overridings for these subprograms.
9256 -- Also ignore this rule for convention CIL since .NET libraries
9257 -- do bizarre things with interfaces???
9259 -- The partial view of T may have been a private extension, for
9260 -- which inherited functions dispatching on result are abstract.
9261 -- If the full view is a null extension, there is no need for
9262 -- overriding in Ada 2005, but wrappers need to be built for them
9263 -- (see exp_ch3, Build_Controlling_Function_Wrappers).
9265 if Is_Null_Extension (T)
9266 and then Has_Controlling_Result (Subp)
9267 and then Ada_Version >= Ada_2005
9268 and then Present (Alias_Subp)
9269 and then not Comes_From_Source (Subp)
9270 and then not Is_Abstract_Subprogram (Alias_Subp)
9271 and then not Is_Access_Type (Etype (Subp))
9275 -- Ada 2005 (AI-251): Internal entities of interfaces need no
9276 -- processing because this check is done with the aliased
9279 elsif Present (Interface_Alias (Subp)) then
9282 elsif (Is_Abstract_Subprogram (Subp)
9283 or else Requires_Overriding (Subp)
9285 (Has_Controlling_Result (Subp)
9286 and then Present (Alias_Subp)
9287 and then not Comes_From_Source (Subp)
9288 and then Sloc (Subp) = Sloc (First_Subtype (T))))
9289 and then not Is_TSS (Subp, TSS_Stream_Input)
9290 and then not Is_TSS (Subp, TSS_Stream_Output)
9291 and then not Is_Abstract_Type (T)
9292 and then Convention (T) /= Convention_CIL
9293 and then not Is_Predefined_Interface_Primitive (Subp)
9295 -- Ada 2005 (AI-251): Do not consider hidden entities associated
9296 -- with abstract interface types because the check will be done
9297 -- with the aliased entity (otherwise we generate a duplicated
9300 and then not Present (Interface_Alias (Subp))
9302 if Present (Alias_Subp) then
9304 -- Only perform the check for a derived subprogram when the
9305 -- type has an explicit record extension. This avoids incorrect
9306 -- flagging of abstract subprograms for the case of a type
9307 -- without an extension that is derived from a formal type
9308 -- with a tagged actual (can occur within a private part).
9310 -- Ada 2005 (AI-391): In the case of an inherited function with
9311 -- a controlling result of the type, the rule does not apply if
9312 -- the type is a null extension (unless the parent function
9313 -- itself is abstract, in which case the function must still be
9314 -- be overridden). The expander will generate an overriding
9315 -- wrapper function calling the parent subprogram (see
9316 -- Exp_Ch3.Make_Controlling_Wrapper_Functions).
9318 Type_Def := Type_Definition (Parent (T));
9320 if Nkind (Type_Def) = N_Derived_Type_Definition
9321 and then Present (Record_Extension_Part (Type_Def))
9323 (Ada_Version < Ada_2005
9324 or else not Is_Null_Extension (T)
9325 or else Ekind (Subp) = E_Procedure
9326 or else not Has_Controlling_Result (Subp)
9327 or else Is_Abstract_Subprogram (Alias_Subp)
9328 or else Requires_Overriding (Subp)
9329 or else Is_Access_Type (Etype (Subp)))
9331 -- Avoid reporting error in case of abstract predefined
9332 -- primitive inherited from interface type because the
9333 -- body of internally generated predefined primitives
9334 -- of tagged types are generated later by Freeze_Type
9336 if Is_Interface (Root_Type (T))
9337 and then Is_Abstract_Subprogram (Subp)
9338 and then Is_Predefined_Dispatching_Operation (Subp)
9339 and then not Comes_From_Source (Ultimate_Alias (Subp))
9345 ("type must be declared abstract or & overridden",
9348 -- Traverse the whole chain of aliased subprograms to
9349 -- complete the error notification. This is especially
9350 -- useful for traceability of the chain of entities when
9351 -- the subprogram corresponds with an interface
9352 -- subprogram (which may be defined in another package).
9354 if Present (Alias_Subp) then
9360 while Present (Alias (E)) loop
9362 -- Avoid reporting redundant errors on entities
9363 -- inherited from interfaces
9365 if Sloc (E) /= Sloc (T) then
9366 Error_Msg_Sloc := Sloc (E);
9368 ("\& has been inherited #", T, Subp);
9374 Error_Msg_Sloc := Sloc (E);
9376 -- AI05-0068: report if there is an overriding
9377 -- non-abstract subprogram that is invisible.
9380 and then not Is_Abstract_Subprogram (E)
9383 ("\& subprogram# is not visible",
9388 ("\& has been inherited from subprogram #",
9395 -- Ada 2005 (AI-345): Protected or task type implementing
9396 -- abstract interfaces.
9398 elsif Is_Concurrent_Record_Type (T)
9399 and then Present (Interfaces (T))
9401 -- The controlling formal of Subp must be of mode "out",
9402 -- "in out" or an access-to-variable to be overridden.
9404 if Ekind (First_Formal (Subp)) = E_In_Parameter
9405 and then Ekind (Subp) /= E_Function
9407 if not Is_Predefined_Dispatching_Operation (Subp)
9408 and then Is_Protected_Type
9409 (Corresponding_Concurrent_Type (T))
9411 Error_Msg_PT (T, Subp);
9414 -- Some other kind of overriding failure
9418 ("interface subprogram & must be overridden",
9421 -- Examine primitive operations of synchronized type,
9422 -- to find homonyms that have the wrong profile.
9429 First_Entity (Corresponding_Concurrent_Type (T));
9430 while Present (Prim) loop
9431 if Chars (Prim) = Chars (Subp) then
9433 ("profile is not type conformant with "
9434 & "prefixed view profile of "
9435 & "inherited operation&", Prim, Subp);
9445 Error_Msg_Node_2 := T;
9447 ("abstract subprogram& not allowed for type&", Subp);
9449 -- Also post unconditional warning on the type (unconditional
9450 -- so that if there are more than one of these cases, we get
9451 -- them all, and not just the first one).
9453 Error_Msg_Node_2 := Subp;
9454 Error_Msg_N ("nonabstract type& has abstract subprogram&!", T);
9458 -- Ada 2012 (AI05-0030): Perform some checks related to pragma
9461 -- Subp is an expander-generated procedure which maps an interface
9462 -- alias to a protected wrapper. The interface alias is flagged by
9463 -- pragma Implemented. Ensure that Subp is a procedure when the
9464 -- implementation kind is By_Protected_Procedure or an entry when
9467 if Ada_Version >= Ada_2012
9468 and then Is_Hidden (Subp)
9469 and then Present (Interface_Alias (Subp))
9470 and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented)
9472 Check_Pragma_Implemented (Subp);
9475 -- Subp is an interface primitive which overrides another interface
9476 -- primitive marked with pragma Implemented.
9478 if Ada_Version >= Ada_2012
9479 and then Present (Overridden_Operation (Subp))
9480 and then Has_Rep_Pragma
9481 (Overridden_Operation (Subp), Name_Implemented)
9483 -- If the overriding routine is also marked by Implemented, check
9484 -- that the two implementation kinds are conforming.
9486 if Has_Rep_Pragma (Subp, Name_Implemented) then
9487 Check_Pragma_Implemented
9489 Iface_Subp => Overridden_Operation (Subp));
9491 -- Otherwise the overriding routine inherits the implementation
9492 -- kind from the overridden subprogram.
9495 Inherit_Pragma_Implemented
9497 Iface_Subp => Overridden_Operation (Subp));
9501 -- If the operation is a wrapper for a synchronized primitive, it
9502 -- may be called indirectly through a dispatching select. We assume
9503 -- that it will be referenced elsewhere indirectly, and suppress
9504 -- warnings about an unused entity.
9506 if Is_Primitive_Wrapper (Subp)
9507 and then Present (Wrapped_Entity (Subp))
9509 Set_Referenced (Wrapped_Entity (Subp));
9514 end Check_Abstract_Overriding;
9516 ------------------------------------------------
9517 -- Check_Access_Discriminant_Requires_Limited --
9518 ------------------------------------------------
9520 procedure Check_Access_Discriminant_Requires_Limited
9525 -- A discriminant_specification for an access discriminant shall appear
9526 -- only in the declaration for a task or protected type, or for a type
9527 -- with the reserved word 'limited' in its definition or in one of its
9528 -- ancestors (RM 3.7(10)).
9530 -- AI-0063: The proper condition is that type must be immutably limited,
9531 -- or else be a partial view.
9533 if Nkind (Discriminant_Type (D)) = N_Access_Definition then
9534 if Is_Immutably_Limited_Type (Current_Scope)
9536 (Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration
9537 and then Limited_Present (Parent (Current_Scope)))
9543 ("access discriminants allowed only for limited types", Loc);
9546 end Check_Access_Discriminant_Requires_Limited;
9548 -----------------------------------
9549 -- Check_Aliased_Component_Types --
9550 -----------------------------------
9552 procedure Check_Aliased_Component_Types (T : Entity_Id) is
9556 -- ??? Also need to check components of record extensions, but not
9557 -- components of protected types (which are always limited).
9559 -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
9560 -- types to be unconstrained. This is safe because it is illegal to
9561 -- create access subtypes to such types with explicit discriminant
9564 if not Is_Limited_Type (T) then
9565 if Ekind (T) = E_Record_Type then
9566 C := First_Component (T);
9567 while Present (C) loop
9569 and then Has_Discriminants (Etype (C))
9570 and then not Is_Constrained (Etype (C))
9571 and then not In_Instance_Body
9572 and then Ada_Version < Ada_2005
9575 ("aliased component must be constrained (RM 3.6(11))",
9582 elsif Ekind (T) = E_Array_Type then
9583 if Has_Aliased_Components (T)
9584 and then Has_Discriminants (Component_Type (T))
9585 and then not Is_Constrained (Component_Type (T))
9586 and then not In_Instance_Body
9587 and then Ada_Version < Ada_2005
9590 ("aliased component type must be constrained (RM 3.6(11))",
9595 end Check_Aliased_Component_Types;
9597 ----------------------
9598 -- Check_Completion --
9599 ----------------------
9601 procedure Check_Completion (Body_Id : Node_Id := Empty) is
9604 procedure Post_Error;
9605 -- Post error message for lack of completion for entity E
9611 procedure Post_Error is
9613 procedure Missing_Body;
9614 -- Output missing body message
9620 procedure Missing_Body is
9622 -- Spec is in same unit, so we can post on spec
9624 if In_Same_Source_Unit (Body_Id, E) then
9625 Error_Msg_N ("missing body for &", E);
9627 -- Spec is in a separate unit, so we have to post on the body
9630 Error_Msg_NE ("missing body for & declared#!", Body_Id, E);
9634 -- Start of processing for Post_Error
9637 if not Comes_From_Source (E) then
9639 if Ekind_In (E, E_Task_Type, E_Protected_Type) then
9640 -- It may be an anonymous protected type created for a
9641 -- single variable. Post error on variable, if present.
9647 Var := First_Entity (Current_Scope);
9648 while Present (Var) loop
9649 exit when Etype (Var) = E
9650 and then Comes_From_Source (Var);
9655 if Present (Var) then
9662 -- If a generated entity has no completion, then either previous
9663 -- semantic errors have disabled the expansion phase, or else we had
9664 -- missing subunits, or else we are compiling without expansion,
9665 -- or else something is very wrong.
9667 if not Comes_From_Source (E) then
9669 (Serious_Errors_Detected > 0
9670 or else Configurable_Run_Time_Violations > 0
9671 or else Subunits_Missing
9672 or else not Expander_Active);
9675 -- Here for source entity
9678 -- Here if no body to post the error message, so we post the error
9679 -- on the declaration that has no completion. This is not really
9680 -- the right place to post it, think about this later ???
9682 if No (Body_Id) then
9685 ("missing full declaration for }", Parent (E), E);
9687 Error_Msg_NE ("missing body for &", Parent (E), E);
9690 -- Package body has no completion for a declaration that appears
9691 -- in the corresponding spec. Post error on the body, with a
9692 -- reference to the non-completed declaration.
9695 Error_Msg_Sloc := Sloc (E);
9698 Error_Msg_NE ("missing full declaration for }!", Body_Id, E);
9700 elsif Is_Overloadable (E)
9701 and then Current_Entity_In_Scope (E) /= E
9703 -- It may be that the completion is mistyped and appears as
9704 -- a distinct overloading of the entity.
9707 Candidate : constant Entity_Id :=
9708 Current_Entity_In_Scope (E);
9709 Decl : constant Node_Id :=
9710 Unit_Declaration_Node (Candidate);
9713 if Is_Overloadable (Candidate)
9714 and then Ekind (Candidate) = Ekind (E)
9715 and then Nkind (Decl) = N_Subprogram_Body
9716 and then Acts_As_Spec (Decl)
9718 Check_Type_Conformant (Candidate, E);
9732 -- Start of processing for Check_Completion
9735 E := First_Entity (Current_Scope);
9736 while Present (E) loop
9737 if Is_Intrinsic_Subprogram (E) then
9740 -- The following situation requires special handling: a child unit
9741 -- that appears in the context clause of the body of its parent:
9743 -- procedure Parent.Child (...);
9745 -- with Parent.Child;
9746 -- package body Parent is
9748 -- Here Parent.Child appears as a local entity, but should not be
9749 -- flagged as requiring completion, because it is a compilation
9752 -- Ignore missing completion for a subprogram that does not come from
9753 -- source (including the _Call primitive operation of RAS types,
9754 -- which has to have the flag Comes_From_Source for other purposes):
9755 -- we assume that the expander will provide the missing completion.
9756 -- In case of previous errors, other expansion actions that provide
9757 -- bodies for null procedures with not be invoked, so inhibit message
9760 -- Note that E_Operator is not in the list that follows, because
9761 -- this kind is reserved for predefined operators, that are
9762 -- intrinsic and do not need completion.
9764 elsif Ekind (E) = E_Function
9765 or else Ekind (E) = E_Procedure
9766 or else Ekind (E) = E_Generic_Function
9767 or else Ekind (E) = E_Generic_Procedure
9769 if Has_Completion (E) then
9772 elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then
9775 elsif Is_Subprogram (E)
9776 and then (not Comes_From_Source (E)
9777 or else Chars (E) = Name_uCall)
9782 Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
9786 elsif Nkind (Parent (E)) = N_Procedure_Specification
9787 and then Null_Present (Parent (E))
9788 and then Serious_Errors_Detected > 0
9796 elsif Is_Entry (E) then
9797 if not Has_Completion (E) and then
9798 (Ekind (Scope (E)) = E_Protected_Object
9799 or else Ekind (Scope (E)) = E_Protected_Type)
9804 elsif Is_Package_Or_Generic_Package (E) then
9805 if Unit_Requires_Body (E) then
9806 if not Has_Completion (E)
9807 and then Nkind (Parent (Unit_Declaration_Node (E))) /=
9813 elsif not Is_Child_Unit (E) then
9814 May_Need_Implicit_Body (E);
9817 -- A formal incomplete type (Ada 2012) does not require a completion;
9818 -- other incomplete type declarations do.
9820 elsif Ekind (E) = E_Incomplete_Type
9821 and then No (Underlying_Type (E))
9822 and then not Is_Generic_Type (E)
9826 elsif (Ekind (E) = E_Task_Type or else
9827 Ekind (E) = E_Protected_Type)
9828 and then not Has_Completion (E)
9832 -- A single task declared in the current scope is a constant, verify
9833 -- that the body of its anonymous type is in the same scope. If the
9834 -- task is defined elsewhere, this may be a renaming declaration for
9835 -- which no completion is needed.
9837 elsif Ekind (E) = E_Constant
9838 and then Ekind (Etype (E)) = E_Task_Type
9839 and then not Has_Completion (Etype (E))
9840 and then Scope (Etype (E)) = Current_Scope
9844 elsif Ekind (E) = E_Protected_Object
9845 and then not Has_Completion (Etype (E))
9849 elsif Ekind (E) = E_Record_Type then
9850 if Is_Tagged_Type (E) then
9851 Check_Abstract_Overriding (E);
9852 Check_Conventions (E);
9855 Check_Aliased_Component_Types (E);
9857 elsif Ekind (E) = E_Array_Type then
9858 Check_Aliased_Component_Types (E);
9864 end Check_Completion;
9866 ------------------------------------
9867 -- Check_CPP_Type_Has_No_Defaults --
9868 ------------------------------------
9870 procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is
9871 Tdef : constant Node_Id := Type_Definition (Declaration_Node (T));
9876 -- Obtain the component list
9878 if Nkind (Tdef) = N_Record_Definition then
9879 Clist := Component_List (Tdef);
9880 else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition);
9881 Clist := Component_List (Record_Extension_Part (Tdef));
9884 -- Check all components to ensure no default expressions
9886 if Present (Clist) then
9887 Comp := First (Component_Items (Clist));
9888 while Present (Comp) loop
9889 if Present (Expression (Comp)) then
9891 ("component of imported 'C'P'P type cannot have "
9892 & "default expression", Expression (Comp));
9898 end Check_CPP_Type_Has_No_Defaults;
9900 ----------------------------
9901 -- Check_Delta_Expression --
9902 ----------------------------
9904 procedure Check_Delta_Expression (E : Node_Id) is
9906 if not (Is_Real_Type (Etype (E))) then
9907 Wrong_Type (E, Any_Real);
9909 elsif not Is_OK_Static_Expression (E) then
9910 Flag_Non_Static_Expr
9911 ("non-static expression used for delta value!", E);
9913 elsif not UR_Is_Positive (Expr_Value_R (E)) then
9914 Error_Msg_N ("delta expression must be positive", E);
9920 -- If any of above errors occurred, then replace the incorrect
9921 -- expression by the real 0.1, which should prevent further errors.
9924 Make_Real_Literal (Sloc (E), Ureal_Tenth));
9925 Analyze_And_Resolve (E, Standard_Float);
9926 end Check_Delta_Expression;
9928 -----------------------------
9929 -- Check_Digits_Expression --
9930 -----------------------------
9932 procedure Check_Digits_Expression (E : Node_Id) is
9934 if not (Is_Integer_Type (Etype (E))) then
9935 Wrong_Type (E, Any_Integer);
9937 elsif not Is_OK_Static_Expression (E) then
9938 Flag_Non_Static_Expr
9939 ("non-static expression used for digits value!", E);
9941 elsif Expr_Value (E) <= 0 then
9942 Error_Msg_N ("digits value must be greater than zero", E);
9948 -- If any of above errors occurred, then replace the incorrect
9949 -- expression by the integer 1, which should prevent further errors.
9951 Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
9952 Analyze_And_Resolve (E, Standard_Integer);
9954 end Check_Digits_Expression;
9956 --------------------------
9957 -- Check_Initialization --
9958 --------------------------
9960 procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
9962 if Is_Limited_Type (T)
9963 and then not In_Instance
9964 and then not In_Inlined_Body
9966 if not OK_For_Limited_Init (T, Exp) then
9968 -- In GNAT mode, this is just a warning, to allow it to be evilly
9969 -- turned off. Otherwise it is a real error.
9973 ("?cannot initialize entities of limited type!", Exp);
9975 elsif Ada_Version < Ada_2005 then
9977 -- The side effect removal machinery may generate illegal Ada
9978 -- code to avoid the usage of access types and 'reference in
9979 -- SPARK mode. Since this is legal code with respect to theorem
9980 -- proving, do not emit the error.
9983 and then Nkind (Exp) = N_Function_Call
9984 and then Nkind (Parent (Exp)) = N_Object_Declaration
9985 and then not Comes_From_Source
9986 (Defining_Identifier (Parent (Exp)))
9992 ("cannot initialize entities of limited type", Exp);
9993 Explain_Limited_Type (T, Exp);
9997 -- Specialize error message according to kind of illegal
9998 -- initial expression.
10000 if Nkind (Exp) = N_Type_Conversion
10001 and then Nkind (Expression (Exp)) = N_Function_Call
10004 ("illegal context for call"
10005 & " to function with limited result", Exp);
10009 ("initialization of limited object requires aggregate "
10010 & "or function call", Exp);
10015 end Check_Initialization;
10017 ----------------------
10018 -- Check_Interfaces --
10019 ----------------------
10021 procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is
10022 Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N));
10025 Iface_Def : Node_Id;
10026 Iface_Typ : Entity_Id;
10027 Parent_Node : Node_Id;
10029 Is_Task : Boolean := False;
10030 -- Set True if parent type or any progenitor is a task interface
10032 Is_Protected : Boolean := False;
10033 -- Set True if parent type or any progenitor is a protected interface
10035 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id);
10036 -- Check that a progenitor is compatible with declaration.
10037 -- Error is posted on Error_Node.
10043 procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is
10044 Iface_Id : constant Entity_Id :=
10045 Defining_Identifier (Parent (Iface_Def));
10046 Type_Def : Node_Id;
10049 if Nkind (N) = N_Private_Extension_Declaration then
10052 Type_Def := Type_Definition (N);
10055 if Is_Task_Interface (Iface_Id) then
10058 elsif Is_Protected_Interface (Iface_Id) then
10059 Is_Protected := True;
10062 if Is_Synchronized_Interface (Iface_Id) then
10064 -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
10065 -- extension derived from a synchronized interface must explicitly
10066 -- be declared synchronized, because the full view will be a
10067 -- synchronized type.
10069 if Nkind (N) = N_Private_Extension_Declaration then
10070 if not Synchronized_Present (N) then
10072 ("private extension of& must be explicitly synchronized",
10076 -- However, by 3.9.4(16/2), a full type that is a record extension
10077 -- is never allowed to derive from a synchronized interface (note
10078 -- that interfaces must be excluded from this check, because those
10079 -- are represented by derived type definitions in some cases).
10081 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition
10082 and then not Interface_Present (Type_Definition (N))
10084 Error_Msg_N ("record extension cannot derive from synchronized"
10085 & " interface", Error_Node);
10089 -- Check that the characteristics of the progenitor are compatible
10090 -- with the explicit qualifier in the declaration.
10091 -- The check only applies to qualifiers that come from source.
10092 -- Limited_Present also appears in the declaration of corresponding
10093 -- records, and the check does not apply to them.
10095 if Limited_Present (Type_Def)
10097 Is_Concurrent_Record_Type (Defining_Identifier (N))
10099 if Is_Limited_Interface (Parent_Type)
10100 and then not Is_Limited_Interface (Iface_Id)
10103 ("progenitor& must be limited interface",
10104 Error_Node, Iface_Id);
10107 (Task_Present (Iface_Def)
10108 or else Protected_Present (Iface_Def)
10109 or else Synchronized_Present (Iface_Def))
10110 and then Nkind (N) /= N_Private_Extension_Declaration
10111 and then not Error_Posted (N)
10114 ("progenitor& must be limited interface",
10115 Error_Node, Iface_Id);
10118 -- Protected interfaces can only inherit from limited, synchronized
10119 -- or protected interfaces.
10121 elsif Nkind (N) = N_Full_Type_Declaration
10122 and then Protected_Present (Type_Def)
10124 if Limited_Present (Iface_Def)
10125 or else Synchronized_Present (Iface_Def)
10126 or else Protected_Present (Iface_Def)
10130 elsif Task_Present (Iface_Def) then
10131 Error_Msg_N ("(Ada 2005) protected interface cannot inherit"
10132 & " from task interface", Error_Node);
10135 Error_Msg_N ("(Ada 2005) protected interface cannot inherit"
10136 & " from non-limited interface", Error_Node);
10139 -- Ada 2005 (AI-345): Synchronized interfaces can only inherit from
10140 -- limited and synchronized.
10142 elsif Synchronized_Present (Type_Def) then
10143 if Limited_Present (Iface_Def)
10144 or else Synchronized_Present (Iface_Def)
10148 elsif Protected_Present (Iface_Def)
10149 and then Nkind (N) /= N_Private_Extension_Declaration
10151 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
10152 & " from protected interface", Error_Node);
10154 elsif Task_Present (Iface_Def)
10155 and then Nkind (N) /= N_Private_Extension_Declaration
10157 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
10158 & " from task interface", Error_Node);
10160 elsif not Is_Limited_Interface (Iface_Id) then
10161 Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
10162 & " from non-limited interface", Error_Node);
10165 -- Ada 2005 (AI-345): Task interfaces can only inherit from limited,
10166 -- synchronized or task interfaces.
10168 elsif Nkind (N) = N_Full_Type_Declaration
10169 and then Task_Present (Type_Def)
10171 if Limited_Present (Iface_Def)
10172 or else Synchronized_Present (Iface_Def)
10173 or else Task_Present (Iface_Def)
10177 elsif Protected_Present (Iface_Def) then
10178 Error_Msg_N ("(Ada 2005) task interface cannot inherit from"
10179 & " protected interface", Error_Node);
10182 Error_Msg_N ("(Ada 2005) task interface cannot inherit from"
10183 & " non-limited interface", Error_Node);
10188 -- Start of processing for Check_Interfaces
10191 if Is_Interface (Parent_Type) then
10192 if Is_Task_Interface (Parent_Type) then
10195 elsif Is_Protected_Interface (Parent_Type) then
10196 Is_Protected := True;
10200 if Nkind (N) = N_Private_Extension_Declaration then
10202 -- Check that progenitors are compatible with declaration
10204 Iface := First (Interface_List (Def));
10205 while Present (Iface) loop
10206 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
10208 Parent_Node := Parent (Base_Type (Iface_Typ));
10209 Iface_Def := Type_Definition (Parent_Node);
10211 if not Is_Interface (Iface_Typ) then
10212 Diagnose_Interface (Iface, Iface_Typ);
10215 Check_Ifaces (Iface_Def, Iface);
10221 if Is_Task and Is_Protected then
10223 ("type cannot derive from task and protected interface", N);
10229 -- Full type declaration of derived type.
10230 -- Check compatibility with parent if it is interface type
10232 if Nkind (Type_Definition (N)) = N_Derived_Type_Definition
10233 and then Is_Interface (Parent_Type)
10235 Parent_Node := Parent (Parent_Type);
10237 -- More detailed checks for interface varieties
10240 (Iface_Def => Type_Definition (Parent_Node),
10241 Error_Node => Subtype_Indication (Type_Definition (N)));
10244 Iface := First (Interface_List (Def));
10245 while Present (Iface) loop
10246 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
10248 Parent_Node := Parent (Base_Type (Iface_Typ));
10249 Iface_Def := Type_Definition (Parent_Node);
10251 if not Is_Interface (Iface_Typ) then
10252 Diagnose_Interface (Iface, Iface_Typ);
10255 -- "The declaration of a specific descendant of an interface
10256 -- type freezes the interface type" RM 13.14
10258 Freeze_Before (N, Iface_Typ);
10259 Check_Ifaces (Iface_Def, Error_Node => Iface);
10265 if Is_Task and Is_Protected then
10267 ("type cannot derive from task and protected interface", N);
10269 end Check_Interfaces;
10271 ------------------------------------
10272 -- Check_Or_Process_Discriminants --
10273 ------------------------------------
10275 -- If an incomplete or private type declaration was already given for the
10276 -- type, the discriminants may have already been processed if they were
10277 -- present on the incomplete declaration. In this case a full conformance
10278 -- check has been performed in Find_Type_Name, and we then recheck here
10279 -- some properties that can't be checked on the partial view alone.
10280 -- Otherwise we call Process_Discriminants.
10282 procedure Check_Or_Process_Discriminants
10285 Prev : Entity_Id := Empty)
10288 if Has_Discriminants (T) then
10290 -- Discriminants are already set on T if they were already present
10291 -- on the partial view. Make them visible to component declarations.
10295 -- Discriminant on T (full view) referencing expr on partial view
10297 Prev_D : Entity_Id;
10298 -- Entity of corresponding discriminant on partial view
10301 -- Discriminant specification for full view, expression is the
10302 -- syntactic copy on full view (which has been checked for
10303 -- conformance with partial view), only used here to post error
10307 D := First_Discriminant (T);
10308 New_D := First (Discriminant_Specifications (N));
10309 while Present (D) loop
10310 Prev_D := Current_Entity (D);
10311 Set_Current_Entity (D);
10312 Set_Is_Immediately_Visible (D);
10313 Set_Homonym (D, Prev_D);
10315 -- Handle the case where there is an untagged partial view and
10316 -- the full view is tagged: must disallow discriminants with
10317 -- defaults, unless compiling for Ada 2012, which allows a
10318 -- limited tagged type to have defaulted discriminants (see
10319 -- AI05-0214). However, suppress the error here if it was
10320 -- already reported on the default expression of the partial
10323 if Is_Tagged_Type (T)
10324 and then Present (Expression (Parent (D)))
10325 and then (not Is_Limited_Type (Current_Scope)
10326 or else Ada_Version < Ada_2012)
10327 and then not Error_Posted (Expression (Parent (D)))
10329 if Ada_Version >= Ada_2012 then
10331 ("discriminants of nonlimited tagged type cannot have"
10333 Expression (New_D));
10336 ("discriminants of tagged type cannot have defaults",
10337 Expression (New_D));
10341 -- Ada 2005 (AI-230): Access discriminant allowed in
10342 -- non-limited record types.
10344 if Ada_Version < Ada_2005 then
10346 -- This restriction gets applied to the full type here. It
10347 -- has already been applied earlier to the partial view.
10349 Check_Access_Discriminant_Requires_Limited (Parent (D), N);
10352 Next_Discriminant (D);
10357 elsif Present (Discriminant_Specifications (N)) then
10358 Process_Discriminants (N, Prev);
10360 end Check_Or_Process_Discriminants;
10362 ----------------------
10363 -- Check_Real_Bound --
10364 ----------------------
10366 procedure Check_Real_Bound (Bound : Node_Id) is
10368 if not Is_Real_Type (Etype (Bound)) then
10370 ("bound in real type definition must be of real type", Bound);
10372 elsif not Is_OK_Static_Expression (Bound) then
10373 Flag_Non_Static_Expr
10374 ("non-static expression used for real type bound!", Bound);
10381 (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
10383 Resolve (Bound, Standard_Float);
10384 end Check_Real_Bound;
10386 ------------------------------
10387 -- Complete_Private_Subtype --
10388 ------------------------------
10390 procedure Complete_Private_Subtype
10393 Full_Base : Entity_Id;
10394 Related_Nod : Node_Id)
10396 Save_Next_Entity : Entity_Id;
10397 Save_Homonym : Entity_Id;
10400 -- Set semantic attributes for (implicit) private subtype completion.
10401 -- If the full type has no discriminants, then it is a copy of the full
10402 -- view of the base. Otherwise, it is a subtype of the base with a
10403 -- possible discriminant constraint. Save and restore the original
10404 -- Next_Entity field of full to ensure that the calls to Copy_Node
10405 -- do not corrupt the entity chain.
10407 -- Note that the type of the full view is the same entity as the type of
10408 -- the partial view. In this fashion, the subtype has access to the
10409 -- correct view of the parent.
10411 Save_Next_Entity := Next_Entity (Full);
10412 Save_Homonym := Homonym (Priv);
10414 case Ekind (Full_Base) is
10415 when E_Record_Type |
10421 Copy_Node (Priv, Full);
10423 Set_Has_Discriminants
10424 (Full, Has_Discriminants (Full_Base));
10425 Set_Has_Unknown_Discriminants
10426 (Full, Has_Unknown_Discriminants (Full_Base));
10427 Set_First_Entity (Full, First_Entity (Full_Base));
10428 Set_Last_Entity (Full, Last_Entity (Full_Base));
10430 -- If the underlying base type is constrained, we know that the
10431 -- full view of the subtype is constrained as well (the converse
10432 -- is not necessarily true).
10434 if Is_Constrained (Full_Base) then
10435 Set_Is_Constrained (Full);
10439 Copy_Node (Full_Base, Full);
10441 Set_Chars (Full, Chars (Priv));
10442 Conditional_Delay (Full, Priv);
10443 Set_Sloc (Full, Sloc (Priv));
10446 Set_Next_Entity (Full, Save_Next_Entity);
10447 Set_Homonym (Full, Save_Homonym);
10448 Set_Associated_Node_For_Itype (Full, Related_Nod);
10450 -- Set common attributes for all subtypes: kind, convention, etc.
10452 Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
10453 Set_Convention (Full, Convention (Full_Base));
10455 -- The Etype of the full view is inconsistent. Gigi needs to see the
10456 -- structural full view, which is what the current scheme gives:
10457 -- the Etype of the full view is the etype of the full base. However,
10458 -- if the full base is a derived type, the full view then looks like
10459 -- a subtype of the parent, not a subtype of the full base. If instead
10462 -- Set_Etype (Full, Full_Base);
10464 -- then we get inconsistencies in the front-end (confusion between
10465 -- views). Several outstanding bugs are related to this ???
10467 Set_Is_First_Subtype (Full, False);
10468 Set_Scope (Full, Scope (Priv));
10469 Set_Size_Info (Full, Full_Base);
10470 Set_RM_Size (Full, RM_Size (Full_Base));
10471 Set_Is_Itype (Full);
10473 -- A subtype of a private-type-without-discriminants, whose full-view
10474 -- has discriminants with default expressions, is not constrained!
10476 if not Has_Discriminants (Priv) then
10477 Set_Is_Constrained (Full, Is_Constrained (Full_Base));
10479 if Has_Discriminants (Full_Base) then
10480 Set_Discriminant_Constraint
10481 (Full, Discriminant_Constraint (Full_Base));
10483 -- The partial view may have been indefinite, the full view
10486 Set_Has_Unknown_Discriminants
10487 (Full, Has_Unknown_Discriminants (Full_Base));
10491 Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
10492 Set_Depends_On_Private (Full, Has_Private_Component (Full));
10494 -- Freeze the private subtype entity if its parent is delayed, and not
10495 -- already frozen. We skip this processing if the type is an anonymous
10496 -- subtype of a record component, or is the corresponding record of a
10497 -- protected type, since ???
10499 if not Is_Type (Scope (Full)) then
10500 Set_Has_Delayed_Freeze (Full,
10501 Has_Delayed_Freeze (Full_Base)
10502 and then (not Is_Frozen (Full_Base)));
10505 Set_Freeze_Node (Full, Empty);
10506 Set_Is_Frozen (Full, False);
10507 Set_Full_View (Priv, Full);
10509 if Has_Discriminants (Full) then
10510 Set_Stored_Constraint_From_Discriminant_Constraint (Full);
10511 Set_Stored_Constraint (Priv, Stored_Constraint (Full));
10513 if Has_Unknown_Discriminants (Full) then
10514 Set_Discriminant_Constraint (Full, No_Elist);
10518 if Ekind (Full_Base) = E_Record_Type
10519 and then Has_Discriminants (Full_Base)
10520 and then Has_Discriminants (Priv) -- might not, if errors
10521 and then not Has_Unknown_Discriminants (Priv)
10522 and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
10524 Create_Constrained_Components
10525 (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
10527 -- If the full base is itself derived from private, build a congruent
10528 -- subtype of its underlying type, for use by the back end. For a
10529 -- constrained record component, the declaration cannot be placed on
10530 -- the component list, but it must nevertheless be built an analyzed, to
10531 -- supply enough information for Gigi to compute the size of component.
10533 elsif Ekind (Full_Base) in Private_Kind
10534 and then Is_Derived_Type (Full_Base)
10535 and then Has_Discriminants (Full_Base)
10536 and then (Ekind (Current_Scope) /= E_Record_Subtype)
10538 if not Is_Itype (Priv)
10540 Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
10542 Build_Underlying_Full_View
10543 (Parent (Priv), Full, Etype (Full_Base));
10545 elsif Nkind (Related_Nod) = N_Component_Declaration then
10546 Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
10549 elsif Is_Record_Type (Full_Base) then
10551 -- Show Full is simply a renaming of Full_Base
10553 Set_Cloned_Subtype (Full, Full_Base);
10556 -- It is unsafe to share the bounds of a scalar type, because the Itype
10557 -- is elaborated on demand, and if a bound is non-static then different
10558 -- orders of elaboration in different units will lead to different
10559 -- external symbols.
10561 if Is_Scalar_Type (Full_Base) then
10562 Set_Scalar_Range (Full,
10563 Make_Range (Sloc (Related_Nod),
10565 Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
10567 Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
10569 -- This completion inherits the bounds of the full parent, but if
10570 -- the parent is an unconstrained floating point type, so is the
10573 if Is_Floating_Point_Type (Full_Base) then
10574 Set_Includes_Infinities
10575 (Scalar_Range (Full), Has_Infinities (Full_Base));
10579 -- ??? It seems that a lot of fields are missing that should be copied
10580 -- from Full_Base to Full. Here are some that are introduced in a
10581 -- non-disruptive way but a cleanup is necessary.
10583 if Is_Tagged_Type (Full_Base) then
10584 Set_Is_Tagged_Type (Full);
10585 Set_Direct_Primitive_Operations (Full,
10586 Direct_Primitive_Operations (Full_Base));
10588 -- Inherit class_wide type of full_base in case the partial view was
10589 -- not tagged. Otherwise it has already been created when the private
10590 -- subtype was analyzed.
10592 if No (Class_Wide_Type (Full)) then
10593 Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
10596 -- If this is a subtype of a protected or task type, constrain its
10597 -- corresponding record, unless this is a subtype without constraints,
10598 -- i.e. a simple renaming as with an actual subtype in an instance.
10600 elsif Is_Concurrent_Type (Full_Base) then
10601 if Has_Discriminants (Full)
10602 and then Present (Corresponding_Record_Type (Full_Base))
10604 not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
10606 Set_Corresponding_Record_Type (Full,
10607 Constrain_Corresponding_Record
10608 (Full, Corresponding_Record_Type (Full_Base),
10609 Related_Nod, Full_Base));
10612 Set_Corresponding_Record_Type (Full,
10613 Corresponding_Record_Type (Full_Base));
10617 -- Link rep item chain, and also setting of Has_Predicates from private
10618 -- subtype to full subtype, since we will need these on the full subtype
10619 -- to create the predicate function. Note that the full subtype may
10620 -- already have rep items, inherited from the full view of the base
10621 -- type, so we must be sure not to overwrite these entries.
10626 Next_Item : Node_Id;
10629 Item := First_Rep_Item (Full);
10631 -- If no existing rep items on full type, we can just link directly
10632 -- to the list of items on the private type.
10635 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
10637 -- Otherwise, search to the end of items currently linked to the full
10638 -- subtype and append the private items to the end. However, if Priv
10639 -- and Full already have the same list of rep items, then the append
10640 -- is not done, as that would create a circularity.
10642 elsif Item /= First_Rep_Item (Priv) then
10646 Next_Item := Next_Rep_Item (Item);
10647 exit when No (Next_Item);
10650 -- If the private view has aspect specifications, the full view
10651 -- inherits them. Since these aspects may already have been
10652 -- attached to the full view during derivation, do not append
10653 -- them if already present.
10655 if Item = First_Rep_Item (Priv) then
10661 -- And link the private type items at the end of the chain
10664 Set_Next_Rep_Item (Item, First_Rep_Item (Priv));
10669 -- Make sure Has_Predicates is set on full type if it is set on the
10670 -- private type. Note that it may already be set on the full type and
10671 -- if so, we don't want to unset it.
10673 if Has_Predicates (Priv) then
10674 Set_Has_Predicates (Full);
10676 end Complete_Private_Subtype;
10678 ----------------------------
10679 -- Constant_Redeclaration --
10680 ----------------------------
10682 procedure Constant_Redeclaration
10687 Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
10688 Obj_Def : constant Node_Id := Object_Definition (N);
10691 procedure Check_Possible_Deferred_Completion
10692 (Prev_Id : Entity_Id;
10693 Prev_Obj_Def : Node_Id;
10694 Curr_Obj_Def : Node_Id);
10695 -- Determine whether the two object definitions describe the partial
10696 -- and the full view of a constrained deferred constant. Generate
10697 -- a subtype for the full view and verify that it statically matches
10698 -- the subtype of the partial view.
10700 procedure Check_Recursive_Declaration (Typ : Entity_Id);
10701 -- If deferred constant is an access type initialized with an allocator,
10702 -- check whether there is an illegal recursion in the definition,
10703 -- through a default value of some record subcomponent. This is normally
10704 -- detected when generating init procs, but requires this additional
10705 -- mechanism when expansion is disabled.
10707 ----------------------------------------
10708 -- Check_Possible_Deferred_Completion --
10709 ----------------------------------------
10711 procedure Check_Possible_Deferred_Completion
10712 (Prev_Id : Entity_Id;
10713 Prev_Obj_Def : Node_Id;
10714 Curr_Obj_Def : Node_Id)
10717 if Nkind (Prev_Obj_Def) = N_Subtype_Indication
10718 and then Present (Constraint (Prev_Obj_Def))
10719 and then Nkind (Curr_Obj_Def) = N_Subtype_Indication
10720 and then Present (Constraint (Curr_Obj_Def))
10723 Loc : constant Source_Ptr := Sloc (N);
10724 Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
10725 Decl : constant Node_Id :=
10726 Make_Subtype_Declaration (Loc,
10727 Defining_Identifier => Def_Id,
10728 Subtype_Indication =>
10729 Relocate_Node (Curr_Obj_Def));
10732 Insert_Before_And_Analyze (N, Decl);
10733 Set_Etype (Id, Def_Id);
10735 if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then
10736 Error_Msg_Sloc := Sloc (Prev_Id);
10737 Error_Msg_N ("subtype does not statically match deferred " &
10738 "declaration#", N);
10742 end Check_Possible_Deferred_Completion;
10744 ---------------------------------
10745 -- Check_Recursive_Declaration --
10746 ---------------------------------
10748 procedure Check_Recursive_Declaration (Typ : Entity_Id) is
10752 if Is_Record_Type (Typ) then
10753 Comp := First_Component (Typ);
10754 while Present (Comp) loop
10755 if Comes_From_Source (Comp) then
10756 if Present (Expression (Parent (Comp)))
10757 and then Is_Entity_Name (Expression (Parent (Comp)))
10758 and then Entity (Expression (Parent (Comp))) = Prev
10760 Error_Msg_Sloc := Sloc (Parent (Comp));
10762 ("illegal circularity with declaration for&#",
10766 elsif Is_Record_Type (Etype (Comp)) then
10767 Check_Recursive_Declaration (Etype (Comp));
10771 Next_Component (Comp);
10774 end Check_Recursive_Declaration;
10776 -- Start of processing for Constant_Redeclaration
10779 if Nkind (Parent (Prev)) = N_Object_Declaration then
10780 if Nkind (Object_Definition
10781 (Parent (Prev))) = N_Subtype_Indication
10783 -- Find type of new declaration. The constraints of the two
10784 -- views must match statically, but there is no point in
10785 -- creating an itype for the full view.
10787 if Nkind (Obj_Def) = N_Subtype_Indication then
10788 Find_Type (Subtype_Mark (Obj_Def));
10789 New_T := Entity (Subtype_Mark (Obj_Def));
10792 Find_Type (Obj_Def);
10793 New_T := Entity (Obj_Def);
10799 -- The full view may impose a constraint, even if the partial
10800 -- view does not, so construct the subtype.
10802 New_T := Find_Type_Of_Object (Obj_Def, N);
10807 -- Current declaration is illegal, diagnosed below in Enter_Name
10813 -- If previous full declaration or a renaming declaration exists, or if
10814 -- a homograph is present, let Enter_Name handle it, either with an
10815 -- error or with the removal of an overridden implicit subprogram.
10817 if Ekind (Prev) /= E_Constant
10818 or else Nkind (Parent (Prev)) = N_Object_Renaming_Declaration
10819 or else Present (Expression (Parent (Prev)))
10820 or else Present (Full_View (Prev))
10824 -- Verify that types of both declarations match, or else that both types
10825 -- are anonymous access types whose designated subtypes statically match
10826 -- (as allowed in Ada 2005 by AI-385).
10828 elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
10830 (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
10831 or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
10832 or else Is_Access_Constant (Etype (New_T)) /=
10833 Is_Access_Constant (Etype (Prev))
10834 or else Can_Never_Be_Null (Etype (New_T)) /=
10835 Can_Never_Be_Null (Etype (Prev))
10836 or else Null_Exclusion_Present (Parent (Prev)) /=
10837 Null_Exclusion_Present (Parent (Id))
10838 or else not Subtypes_Statically_Match
10839 (Designated_Type (Etype (Prev)),
10840 Designated_Type (Etype (New_T))))
10842 Error_Msg_Sloc := Sloc (Prev);
10843 Error_Msg_N ("type does not match declaration#", N);
10844 Set_Full_View (Prev, Id);
10845 Set_Etype (Id, Any_Type);
10848 Null_Exclusion_Present (Parent (Prev))
10849 and then not Null_Exclusion_Present (N)
10851 Error_Msg_Sloc := Sloc (Prev);
10852 Error_Msg_N ("null-exclusion does not match declaration#", N);
10853 Set_Full_View (Prev, Id);
10854 Set_Etype (Id, Any_Type);
10856 -- If so, process the full constant declaration
10859 -- RM 7.4 (6): If the subtype defined by the subtype_indication in
10860 -- the deferred declaration is constrained, then the subtype defined
10861 -- by the subtype_indication in the full declaration shall match it
10864 Check_Possible_Deferred_Completion
10866 Prev_Obj_Def => Object_Definition (Parent (Prev)),
10867 Curr_Obj_Def => Obj_Def);
10869 Set_Full_View (Prev, Id);
10870 Set_Is_Public (Id, Is_Public (Prev));
10871 Set_Is_Internal (Id);
10872 Append_Entity (Id, Current_Scope);
10874 -- Check ALIASED present if present before (RM 7.4(7))
10876 if Is_Aliased (Prev)
10877 and then not Aliased_Present (N)
10879 Error_Msg_Sloc := Sloc (Prev);
10880 Error_Msg_N ("ALIASED required (see declaration#)", N);
10883 -- Check that placement is in private part and that the incomplete
10884 -- declaration appeared in the visible part.
10886 if Ekind (Current_Scope) = E_Package
10887 and then not In_Private_Part (Current_Scope)
10889 Error_Msg_Sloc := Sloc (Prev);
10891 ("full constant for declaration#"
10892 & " must be in private part", N);
10894 elsif Ekind (Current_Scope) = E_Package
10896 List_Containing (Parent (Prev)) /=
10897 Visible_Declarations
10898 (Specification (Unit_Declaration_Node (Current_Scope)))
10901 ("deferred constant must be declared in visible part",
10905 if Is_Access_Type (T)
10906 and then Nkind (Expression (N)) = N_Allocator
10908 Check_Recursive_Declaration (Designated_Type (T));
10911 -- A deferred constant is a visible entity. If type has invariants,
10912 -- verify that the initial value satisfies them.
10914 if Has_Invariants (T) and then Present (Invariant_Procedure (T)) then
10916 Make_Invariant_Call (New_Occurrence_Of (Prev, Sloc (N))));
10919 end Constant_Redeclaration;
10921 ----------------------
10922 -- Constrain_Access --
10923 ----------------------
10925 procedure Constrain_Access
10926 (Def_Id : in out Entity_Id;
10928 Related_Nod : Node_Id)
10930 T : constant Entity_Id := Entity (Subtype_Mark (S));
10931 Desig_Type : constant Entity_Id := Designated_Type (T);
10932 Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
10933 Constraint_OK : Boolean := True;
10935 function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean;
10936 -- Simple predicate to test for defaulted discriminants
10937 -- Shouldn't this be in sem_util???
10939 ---------------------------------
10940 -- Has_Defaulted_Discriminants --
10941 ---------------------------------
10943 function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean is
10945 return Has_Discriminants (Typ)
10946 and then Present (First_Discriminant (Typ))
10948 (Discriminant_Default_Value (First_Discriminant (Typ)));
10949 end Has_Defaulted_Discriminants;
10951 -- Start of processing for Constrain_Access
10954 if Is_Array_Type (Desig_Type) then
10955 Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
10957 elsif (Is_Record_Type (Desig_Type)
10958 or else Is_Incomplete_Or_Private_Type (Desig_Type))
10959 and then not Is_Constrained (Desig_Type)
10961 -- ??? The following code is a temporary kludge to ignore a
10962 -- discriminant constraint on access type if it is constraining
10963 -- the current record. Avoid creating the implicit subtype of the
10964 -- record we are currently compiling since right now, we cannot
10965 -- handle these. For now, just return the access type itself.
10967 if Desig_Type = Current_Scope
10968 and then No (Def_Id)
10970 Set_Ekind (Desig_Subtype, E_Record_Subtype);
10971 Def_Id := Entity (Subtype_Mark (S));
10973 -- This call added to ensure that the constraint is analyzed
10974 -- (needed for a B test). Note that we still return early from
10975 -- this procedure to avoid recursive processing. ???
10977 Constrain_Discriminated_Type
10978 (Desig_Subtype, S, Related_Nod, For_Access => True);
10982 -- Enforce rule that the constraint is illegal if there is an
10983 -- unconstrained view of the designated type. This means that the
10984 -- partial view (either a private type declaration or a derivation
10985 -- from a private type) has no discriminants. (Defect Report
10986 -- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001).
10988 -- Rule updated for Ada 2005: the private type is said to have
10989 -- a constrained partial view, given that objects of the type
10990 -- can be declared. Furthermore, the rule applies to all access
10991 -- types, unlike the rule concerning default discriminants (see
10994 if (Ekind (T) = E_General_Access_Type
10995 or else Ada_Version >= Ada_2005)
10996 and then Has_Private_Declaration (Desig_Type)
10997 and then In_Open_Scopes (Scope (Desig_Type))
10998 and then Has_Discriminants (Desig_Type)
11001 Pack : constant Node_Id :=
11002 Unit_Declaration_Node (Scope (Desig_Type));
11007 if Nkind (Pack) = N_Package_Declaration then
11008 Decls := Visible_Declarations (Specification (Pack));
11009 Decl := First (Decls);
11010 while Present (Decl) loop
11011 if (Nkind (Decl) = N_Private_Type_Declaration
11013 Chars (Defining_Identifier (Decl)) =
11014 Chars (Desig_Type))
11017 (Nkind (Decl) = N_Full_Type_Declaration
11019 Chars (Defining_Identifier (Decl)) =
11021 and then Is_Derived_Type (Desig_Type)
11023 Has_Private_Declaration (Etype (Desig_Type)))
11025 if No (Discriminant_Specifications (Decl)) then
11027 ("cannot constrain access type if designated " &
11028 "type has constrained partial view", S);
11040 Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
11041 For_Access => True);
11043 elsif (Is_Task_Type (Desig_Type)
11044 or else Is_Protected_Type (Desig_Type))
11045 and then not Is_Constrained (Desig_Type)
11047 Constrain_Concurrent
11048 (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
11051 Error_Msg_N ("invalid constraint on access type", S);
11052 Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
11053 Constraint_OK := False;
11056 if No (Def_Id) then
11057 Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
11059 Set_Ekind (Def_Id, E_Access_Subtype);
11062 if Constraint_OK then
11063 Set_Etype (Def_Id, Base_Type (T));
11065 if Is_Private_Type (Desig_Type) then
11066 Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
11069 Set_Etype (Def_Id, Any_Type);
11072 Set_Size_Info (Def_Id, T);
11073 Set_Is_Constrained (Def_Id, Constraint_OK);
11074 Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
11075 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
11076 Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
11078 Conditional_Delay (Def_Id, T);
11080 -- AI-363 : Subtypes of general access types whose designated types have
11081 -- default discriminants are disallowed. In instances, the rule has to
11082 -- be checked against the actual, of which T is the subtype. In a
11083 -- generic body, the rule is checked assuming that the actual type has
11084 -- defaulted discriminants.
11086 if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then
11087 if Ekind (Base_Type (T)) = E_General_Access_Type
11088 and then Has_Defaulted_Discriminants (Desig_Type)
11090 if Ada_Version < Ada_2005 then
11092 ("access subtype of general access type would not " &
11093 "be allowed in Ada 2005?y?", S);
11096 ("access subtype of general access type not allowed", S);
11099 Error_Msg_N ("\discriminants have defaults", S);
11101 elsif Is_Access_Type (T)
11102 and then Is_Generic_Type (Desig_Type)
11103 and then Has_Discriminants (Desig_Type)
11104 and then In_Package_Body (Current_Scope)
11106 if Ada_Version < Ada_2005 then
11108 ("access subtype would not be allowed in generic body " &
11109 "in Ada 2005?y?", S);
11112 ("access subtype not allowed in generic body", S);
11116 ("\designated type is a discriminated formal", S);
11119 end Constrain_Access;
11121 ---------------------
11122 -- Constrain_Array --
11123 ---------------------
11125 procedure Constrain_Array
11126 (Def_Id : in out Entity_Id;
11128 Related_Nod : Node_Id;
11129 Related_Id : Entity_Id;
11130 Suffix : Character)
11132 C : constant Node_Id := Constraint (SI);
11133 Number_Of_Constraints : Nat := 0;
11136 Constraint_OK : Boolean := True;
11139 T := Entity (Subtype_Mark (SI));
11141 if Ekind (T) in Access_Kind then
11142 T := Designated_Type (T);
11145 -- If an index constraint follows a subtype mark in a subtype indication
11146 -- then the type or subtype denoted by the subtype mark must not already
11147 -- impose an index constraint. The subtype mark must denote either an
11148 -- unconstrained array type or an access type whose designated type
11149 -- is such an array type... (RM 3.6.1)
11151 if Is_Constrained (T) then
11152 Error_Msg_N ("array type is already constrained", Subtype_Mark (SI));
11153 Constraint_OK := False;
11156 S := First (Constraints (C));
11157 while Present (S) loop
11158 Number_Of_Constraints := Number_Of_Constraints + 1;
11162 -- In either case, the index constraint must provide a discrete
11163 -- range for each index of the array type and the type of each
11164 -- discrete range must be the same as that of the corresponding
11165 -- index. (RM 3.6.1)
11167 if Number_Of_Constraints /= Number_Dimensions (T) then
11168 Error_Msg_NE ("incorrect number of index constraints for }", C, T);
11169 Constraint_OK := False;
11172 S := First (Constraints (C));
11173 Index := First_Index (T);
11176 -- Apply constraints to each index type
11178 for J in 1 .. Number_Of_Constraints loop
11179 Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
11187 if No (Def_Id) then
11189 Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
11190 Set_Parent (Def_Id, Related_Nod);
11193 Set_Ekind (Def_Id, E_Array_Subtype);
11196 Set_Size_Info (Def_Id, (T));
11197 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11198 Set_Etype (Def_Id, Base_Type (T));
11200 if Constraint_OK then
11201 Set_First_Index (Def_Id, First (Constraints (C)));
11203 Set_First_Index (Def_Id, First_Index (T));
11206 Set_Is_Constrained (Def_Id, True);
11207 Set_Is_Aliased (Def_Id, Is_Aliased (T));
11208 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
11210 Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
11211 Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
11213 -- A subtype does not inherit the packed_array_type of is parent. We
11214 -- need to initialize the attribute because if Def_Id is previously
11215 -- analyzed through a limited_with clause, it will have the attributes
11216 -- of an incomplete type, one of which is an Elist that overlaps the
11217 -- Packed_Array_Type field.
11219 Set_Packed_Array_Type (Def_Id, Empty);
11221 -- Build a freeze node if parent still needs one. Also make sure that
11222 -- the Depends_On_Private status is set because the subtype will need
11223 -- reprocessing at the time the base type does, and also we must set a
11224 -- conditional delay.
11226 Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
11227 Conditional_Delay (Def_Id, T);
11228 end Constrain_Array;
11230 ------------------------------
11231 -- Constrain_Component_Type --
11232 ------------------------------
11234 function Constrain_Component_Type
11236 Constrained_Typ : Entity_Id;
11237 Related_Node : Node_Id;
11239 Constraints : Elist_Id) return Entity_Id
11241 Loc : constant Source_Ptr := Sloc (Constrained_Typ);
11242 Compon_Type : constant Entity_Id := Etype (Comp);
11243 Array_Comp : Node_Id;
11245 function Build_Constrained_Array_Type
11246 (Old_Type : Entity_Id) return Entity_Id;
11247 -- If Old_Type is an array type, one of whose indexes is constrained
11248 -- by a discriminant, build an Itype whose constraint replaces the
11249 -- discriminant with its value in the constraint.
11251 function Build_Constrained_Discriminated_Type
11252 (Old_Type : Entity_Id) return Entity_Id;
11253 -- Ditto for record components
11255 function Build_Constrained_Access_Type
11256 (Old_Type : Entity_Id) return Entity_Id;
11257 -- Ditto for access types. Makes use of previous two functions, to
11258 -- constrain designated type.
11260 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
11261 -- T is an array or discriminated type, C is a list of constraints
11262 -- that apply to T. This routine builds the constrained subtype.
11264 function Is_Discriminant (Expr : Node_Id) return Boolean;
11265 -- Returns True if Expr is a discriminant
11267 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
11268 -- Find the value of discriminant Discrim in Constraint
11270 -----------------------------------
11271 -- Build_Constrained_Access_Type --
11272 -----------------------------------
11274 function Build_Constrained_Access_Type
11275 (Old_Type : Entity_Id) return Entity_Id
11277 Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
11279 Desig_Subtype : Entity_Id;
11283 -- if the original access type was not embedded in the enclosing
11284 -- type definition, there is no need to produce a new access
11285 -- subtype. In fact every access type with an explicit constraint
11286 -- generates an itype whose scope is the enclosing record.
11288 if not Is_Type (Scope (Old_Type)) then
11291 elsif Is_Array_Type (Desig_Type) then
11292 Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
11294 elsif Has_Discriminants (Desig_Type) then
11296 -- This may be an access type to an enclosing record type for
11297 -- which we are constructing the constrained components. Return
11298 -- the enclosing record subtype. This is not always correct,
11299 -- but avoids infinite recursion. ???
11301 Desig_Subtype := Any_Type;
11303 for J in reverse 0 .. Scope_Stack.Last loop
11304 Scop := Scope_Stack.Table (J).Entity;
11307 and then Base_Type (Scop) = Base_Type (Desig_Type)
11309 Desig_Subtype := Scop;
11312 exit when not Is_Type (Scop);
11315 if Desig_Subtype = Any_Type then
11317 Build_Constrained_Discriminated_Type (Desig_Type);
11324 if Desig_Subtype /= Desig_Type then
11326 -- The Related_Node better be here or else we won't be able
11327 -- to attach new itypes to a node in the tree.
11329 pragma Assert (Present (Related_Node));
11331 Itype := Create_Itype (E_Access_Subtype, Related_Node);
11333 Set_Etype (Itype, Base_Type (Old_Type));
11334 Set_Size_Info (Itype, (Old_Type));
11335 Set_Directly_Designated_Type (Itype, Desig_Subtype);
11336 Set_Depends_On_Private (Itype, Has_Private_Component
11338 Set_Is_Access_Constant (Itype, Is_Access_Constant
11341 -- The new itype needs freezing when it depends on a not frozen
11342 -- type and the enclosing subtype needs freezing.
11344 if Has_Delayed_Freeze (Constrained_Typ)
11345 and then not Is_Frozen (Constrained_Typ)
11347 Conditional_Delay (Itype, Base_Type (Old_Type));
11355 end Build_Constrained_Access_Type;
11357 ----------------------------------
11358 -- Build_Constrained_Array_Type --
11359 ----------------------------------
11361 function Build_Constrained_Array_Type
11362 (Old_Type : Entity_Id) return Entity_Id
11366 Old_Index : Node_Id;
11367 Range_Node : Node_Id;
11368 Constr_List : List_Id;
11370 Need_To_Create_Itype : Boolean := False;
11373 Old_Index := First_Index (Old_Type);
11374 while Present (Old_Index) loop
11375 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
11377 if Is_Discriminant (Lo_Expr)
11378 or else Is_Discriminant (Hi_Expr)
11380 Need_To_Create_Itype := True;
11383 Next_Index (Old_Index);
11386 if Need_To_Create_Itype then
11387 Constr_List := New_List;
11389 Old_Index := First_Index (Old_Type);
11390 while Present (Old_Index) loop
11391 Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
11393 if Is_Discriminant (Lo_Expr) then
11394 Lo_Expr := Get_Discr_Value (Lo_Expr);
11397 if Is_Discriminant (Hi_Expr) then
11398 Hi_Expr := Get_Discr_Value (Hi_Expr);
11403 (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
11405 Append (Range_Node, To => Constr_List);
11407 Next_Index (Old_Index);
11410 return Build_Subtype (Old_Type, Constr_List);
11415 end Build_Constrained_Array_Type;
11417 ------------------------------------------
11418 -- Build_Constrained_Discriminated_Type --
11419 ------------------------------------------
11421 function Build_Constrained_Discriminated_Type
11422 (Old_Type : Entity_Id) return Entity_Id
11425 Constr_List : List_Id;
11426 Old_Constraint : Elmt_Id;
11428 Need_To_Create_Itype : Boolean := False;
11431 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
11432 while Present (Old_Constraint) loop
11433 Expr := Node (Old_Constraint);
11435 if Is_Discriminant (Expr) then
11436 Need_To_Create_Itype := True;
11439 Next_Elmt (Old_Constraint);
11442 if Need_To_Create_Itype then
11443 Constr_List := New_List;
11445 Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
11446 while Present (Old_Constraint) loop
11447 Expr := Node (Old_Constraint);
11449 if Is_Discriminant (Expr) then
11450 Expr := Get_Discr_Value (Expr);
11453 Append (New_Copy_Tree (Expr), To => Constr_List);
11455 Next_Elmt (Old_Constraint);
11458 return Build_Subtype (Old_Type, Constr_List);
11463 end Build_Constrained_Discriminated_Type;
11465 -------------------
11466 -- Build_Subtype --
11467 -------------------
11469 function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
11471 Subtyp_Decl : Node_Id;
11472 Def_Id : Entity_Id;
11473 Btyp : Entity_Id := Base_Type (T);
11476 -- The Related_Node better be here or else we won't be able to
11477 -- attach new itypes to a node in the tree.
11479 pragma Assert (Present (Related_Node));
11481 -- If the view of the component's type is incomplete or private
11482 -- with unknown discriminants, then the constraint must be applied
11483 -- to the full type.
11485 if Has_Unknown_Discriminants (Btyp)
11486 and then Present (Underlying_Type (Btyp))
11488 Btyp := Underlying_Type (Btyp);
11492 Make_Subtype_Indication (Loc,
11493 Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
11494 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
11496 Def_Id := Create_Itype (Ekind (T), Related_Node);
11499 Make_Subtype_Declaration (Loc,
11500 Defining_Identifier => Def_Id,
11501 Subtype_Indication => Indic);
11503 Set_Parent (Subtyp_Decl, Parent (Related_Node));
11505 -- Itypes must be analyzed with checks off (see package Itypes)
11507 Analyze (Subtyp_Decl, Suppress => All_Checks);
11512 ---------------------
11513 -- Get_Discr_Value --
11514 ---------------------
11516 function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
11521 -- The discriminant may be declared for the type, in which case we
11522 -- find it by iterating over the list of discriminants. If the
11523 -- discriminant is inherited from a parent type, it appears as the
11524 -- corresponding discriminant of the current type. This will be the
11525 -- case when constraining an inherited component whose constraint is
11526 -- given by a discriminant of the parent.
11528 D := First_Discriminant (Typ);
11529 E := First_Elmt (Constraints);
11531 while Present (D) loop
11532 if D = Entity (Discrim)
11533 or else D = CR_Discriminant (Entity (Discrim))
11534 or else Corresponding_Discriminant (D) = Entity (Discrim)
11539 Next_Discriminant (D);
11543 -- The Corresponding_Discriminant mechanism is incomplete, because
11544 -- the correspondence between new and old discriminants is not one
11545 -- to one: one new discriminant can constrain several old ones. In
11546 -- that case, scan sequentially the stored_constraint, the list of
11547 -- discriminants of the parents, and the constraints.
11549 -- Previous code checked for the present of the Stored_Constraint
11550 -- list for the derived type, but did not use it at all. Should it
11551 -- be present when the component is a discriminated task type?
11553 if Is_Derived_Type (Typ)
11554 and then Scope (Entity (Discrim)) = Etype (Typ)
11556 D := First_Discriminant (Etype (Typ));
11557 E := First_Elmt (Constraints);
11558 while Present (D) loop
11559 if D = Entity (Discrim) then
11563 Next_Discriminant (D);
11568 -- Something is wrong if we did not find the value
11570 raise Program_Error;
11571 end Get_Discr_Value;
11573 ---------------------
11574 -- Is_Discriminant --
11575 ---------------------
11577 function Is_Discriminant (Expr : Node_Id) return Boolean is
11578 Discrim_Scope : Entity_Id;
11581 if Denotes_Discriminant (Expr) then
11582 Discrim_Scope := Scope (Entity (Expr));
11584 -- Either we have a reference to one of Typ's discriminants,
11586 pragma Assert (Discrim_Scope = Typ
11588 -- or to the discriminants of the parent type, in the case
11589 -- of a derivation of a tagged type with variants.
11591 or else Discrim_Scope = Etype (Typ)
11592 or else Full_View (Discrim_Scope) = Etype (Typ)
11594 -- or same as above for the case where the discriminants
11595 -- were declared in Typ's private view.
11597 or else (Is_Private_Type (Discrim_Scope)
11598 and then Chars (Discrim_Scope) = Chars (Typ))
11600 -- or else we are deriving from the full view and the
11601 -- discriminant is declared in the private entity.
11603 or else (Is_Private_Type (Typ)
11604 and then Chars (Discrim_Scope) = Chars (Typ))
11606 -- Or we are constrained the corresponding record of a
11607 -- synchronized type that completes a private declaration.
11609 or else (Is_Concurrent_Record_Type (Typ)
11611 Corresponding_Concurrent_Type (Typ) = Discrim_Scope)
11613 -- or we have a class-wide type, in which case make sure the
11614 -- discriminant found belongs to the root type.
11616 or else (Is_Class_Wide_Type (Typ)
11617 and then Etype (Typ) = Discrim_Scope));
11622 -- In all other cases we have something wrong
11625 end Is_Discriminant;
11627 -- Start of processing for Constrain_Component_Type
11630 if Nkind (Parent (Comp)) = N_Component_Declaration
11631 and then Comes_From_Source (Parent (Comp))
11632 and then Comes_From_Source
11633 (Subtype_Indication (Component_Definition (Parent (Comp))))
11636 (Subtype_Indication (Component_Definition (Parent (Comp))))
11638 return Compon_Type;
11640 elsif Is_Array_Type (Compon_Type) then
11641 Array_Comp := Build_Constrained_Array_Type (Compon_Type);
11643 -- If the component of the parent is packed, and the record type is
11644 -- already frozen, as is the case for an itype, the component type
11645 -- itself will not be frozen, and the packed array type for it must
11646 -- be constructed explicitly. Since the creation of packed types is
11647 -- an expansion activity, we only do this if expansion is active.
11650 and then Is_Packed (Compon_Type)
11651 and then Is_Frozen (Current_Scope)
11653 Create_Packed_Array_Type (Array_Comp);
11658 elsif Has_Discriminants (Compon_Type) then
11659 return Build_Constrained_Discriminated_Type (Compon_Type);
11661 elsif Is_Access_Type (Compon_Type) then
11662 return Build_Constrained_Access_Type (Compon_Type);
11665 return Compon_Type;
11667 end Constrain_Component_Type;
11669 --------------------------
11670 -- Constrain_Concurrent --
11671 --------------------------
11673 -- For concurrent types, the associated record value type carries the same
11674 -- discriminants, so when we constrain a concurrent type, we must constrain
11675 -- the corresponding record type as well.
11677 procedure Constrain_Concurrent
11678 (Def_Id : in out Entity_Id;
11680 Related_Nod : Node_Id;
11681 Related_Id : Entity_Id;
11682 Suffix : Character)
11684 -- Retrieve Base_Type to ensure getting to the concurrent type in the
11685 -- case of a private subtype (needed when only doing semantic analysis).
11687 T_Ent : Entity_Id := Base_Type (Entity (Subtype_Mark (SI)));
11691 if Ekind (T_Ent) in Access_Kind then
11692 T_Ent := Designated_Type (T_Ent);
11695 T_Val := Corresponding_Record_Type (T_Ent);
11697 if Present (T_Val) then
11699 if No (Def_Id) then
11700 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11703 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
11705 Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
11706 Set_Corresponding_Record_Type (Def_Id,
11707 Constrain_Corresponding_Record
11708 (Def_Id, T_Val, Related_Nod, Related_Id));
11711 -- If there is no associated record, expansion is disabled and this
11712 -- is a generic context. Create a subtype in any case, so that
11713 -- semantic analysis can proceed.
11715 if No (Def_Id) then
11716 Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
11719 Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
11721 end Constrain_Concurrent;
11723 ------------------------------------
11724 -- Constrain_Corresponding_Record --
11725 ------------------------------------
11727 function Constrain_Corresponding_Record
11728 (Prot_Subt : Entity_Id;
11729 Corr_Rec : Entity_Id;
11730 Related_Nod : Node_Id;
11731 Related_Id : Entity_Id) return Entity_Id
11733 T_Sub : constant Entity_Id :=
11734 Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
11737 Set_Etype (T_Sub, Corr_Rec);
11738 Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
11739 Set_Is_Constrained (T_Sub, True);
11740 Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
11741 Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
11743 -- As elsewhere, we do not want to create a freeze node for this itype
11744 -- if it is created for a constrained component of an enclosing record
11745 -- because references to outer discriminants will appear out of scope.
11747 if Ekind (Scope (Prot_Subt)) /= E_Record_Type then
11748 Conditional_Delay (T_Sub, Corr_Rec);
11750 Set_Is_Frozen (T_Sub);
11753 if Has_Discriminants (Prot_Subt) then -- False only if errors.
11754 Set_Discriminant_Constraint
11755 (T_Sub, Discriminant_Constraint (Prot_Subt));
11756 Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
11757 Create_Constrained_Components
11758 (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
11761 Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
11764 end Constrain_Corresponding_Record;
11766 -----------------------
11767 -- Constrain_Decimal --
11768 -----------------------
11770 procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
11771 T : constant Entity_Id := Entity (Subtype_Mark (S));
11772 C : constant Node_Id := Constraint (S);
11773 Loc : constant Source_Ptr := Sloc (C);
11774 Range_Expr : Node_Id;
11775 Digits_Expr : Node_Id;
11780 Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
11782 if Nkind (C) = N_Range_Constraint then
11783 Range_Expr := Range_Expression (C);
11784 Digits_Val := Digits_Value (T);
11787 pragma Assert (Nkind (C) = N_Digits_Constraint);
11789 Check_SPARK_Restriction ("digits constraint is not allowed", S);
11791 Digits_Expr := Digits_Expression (C);
11792 Analyze_And_Resolve (Digits_Expr, Any_Integer);
11794 Check_Digits_Expression (Digits_Expr);
11795 Digits_Val := Expr_Value (Digits_Expr);
11797 if Digits_Val > Digits_Value (T) then
11799 ("digits expression is incompatible with subtype", C);
11800 Digits_Val := Digits_Value (T);
11803 if Present (Range_Constraint (C)) then
11804 Range_Expr := Range_Expression (Range_Constraint (C));
11806 Range_Expr := Empty;
11810 Set_Etype (Def_Id, Base_Type (T));
11811 Set_Size_Info (Def_Id, (T));
11812 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11813 Set_Delta_Value (Def_Id, Delta_Value (T));
11814 Set_Scale_Value (Def_Id, Scale_Value (T));
11815 Set_Small_Value (Def_Id, Small_Value (T));
11816 Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
11817 Set_Digits_Value (Def_Id, Digits_Val);
11819 -- Manufacture range from given digits value if no range present
11821 if No (Range_Expr) then
11822 Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
11826 Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
11828 Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
11831 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
11832 Set_Discrete_RM_Size (Def_Id);
11834 -- Unconditionally delay the freeze, since we cannot set size
11835 -- information in all cases correctly until the freeze point.
11837 Set_Has_Delayed_Freeze (Def_Id);
11838 end Constrain_Decimal;
11840 ----------------------------------
11841 -- Constrain_Discriminated_Type --
11842 ----------------------------------
11844 procedure Constrain_Discriminated_Type
11845 (Def_Id : Entity_Id;
11847 Related_Nod : Node_Id;
11848 For_Access : Boolean := False)
11850 E : constant Entity_Id := Entity (Subtype_Mark (S));
11853 Elist : Elist_Id := New_Elmt_List;
11855 procedure Fixup_Bad_Constraint;
11856 -- This is called after finding a bad constraint, and after having
11857 -- posted an appropriate error message. The mission is to leave the
11858 -- entity T in as reasonable state as possible!
11860 --------------------------
11861 -- Fixup_Bad_Constraint --
11862 --------------------------
11864 procedure Fixup_Bad_Constraint is
11866 -- Set a reasonable Ekind for the entity. For an incomplete type,
11867 -- we can't do much, but for other types, we can set the proper
11868 -- corresponding subtype kind.
11870 if Ekind (T) = E_Incomplete_Type then
11871 Set_Ekind (Def_Id, Ekind (T));
11873 Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
11876 -- Set Etype to the known type, to reduce chances of cascaded errors
11878 Set_Etype (Def_Id, E);
11879 Set_Error_Posted (Def_Id);
11880 end Fixup_Bad_Constraint;
11882 -- Start of processing for Constrain_Discriminated_Type
11885 C := Constraint (S);
11887 -- A discriminant constraint is only allowed in a subtype indication,
11888 -- after a subtype mark. This subtype mark must denote either a type
11889 -- with discriminants, or an access type whose designated type is a
11890 -- type with discriminants. A discriminant constraint specifies the
11891 -- values of these discriminants (RM 3.7.2(5)).
11893 T := Base_Type (Entity (Subtype_Mark (S)));
11895 if Ekind (T) in Access_Kind then
11896 T := Designated_Type (T);
11899 -- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal.
11900 -- Avoid generating an error for access-to-incomplete subtypes.
11902 if Ada_Version >= Ada_2005
11903 and then Ekind (T) = E_Incomplete_Type
11904 and then Nkind (Parent (S)) = N_Subtype_Declaration
11905 and then not Is_Itype (Def_Id)
11907 -- A little sanity check, emit an error message if the type
11908 -- has discriminants to begin with. Type T may be a regular
11909 -- incomplete type or imported via a limited with clause.
11911 if Has_Discriminants (T)
11913 (From_With_Type (T)
11914 and then Present (Non_Limited_View (T))
11915 and then Nkind (Parent (Non_Limited_View (T))) =
11916 N_Full_Type_Declaration
11917 and then Present (Discriminant_Specifications
11918 (Parent (Non_Limited_View (T)))))
11921 ("(Ada 2005) incomplete subtype may not be constrained", C);
11923 Error_Msg_N ("invalid constraint: type has no discriminant", C);
11926 Fixup_Bad_Constraint;
11929 -- Check that the type has visible discriminants. The type may be
11930 -- a private type with unknown discriminants whose full view has
11931 -- discriminants which are invisible.
11933 elsif not Has_Discriminants (T)
11935 (Has_Unknown_Discriminants (T)
11936 and then Is_Private_Type (T))
11938 Error_Msg_N ("invalid constraint: type has no discriminant", C);
11939 Fixup_Bad_Constraint;
11942 elsif Is_Constrained (E)
11943 or else (Ekind (E) = E_Class_Wide_Subtype
11944 and then Present (Discriminant_Constraint (E)))
11946 Error_Msg_N ("type is already constrained", Subtype_Mark (S));
11947 Fixup_Bad_Constraint;
11951 -- T may be an unconstrained subtype (e.g. a generic actual).
11952 -- Constraint applies to the base type.
11954 T := Base_Type (T);
11956 Elist := Build_Discriminant_Constraints (T, S);
11958 -- If the list returned was empty we had an error in building the
11959 -- discriminant constraint. We have also already signalled an error
11960 -- in the incomplete type case
11962 if Is_Empty_Elmt_List (Elist) then
11963 Fixup_Bad_Constraint;
11967 Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
11968 end Constrain_Discriminated_Type;
11970 ---------------------------
11971 -- Constrain_Enumeration --
11972 ---------------------------
11974 procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
11975 T : constant Entity_Id := Entity (Subtype_Mark (S));
11976 C : constant Node_Id := Constraint (S);
11979 Set_Ekind (Def_Id, E_Enumeration_Subtype);
11981 Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
11983 Set_Etype (Def_Id, Base_Type (T));
11984 Set_Size_Info (Def_Id, (T));
11985 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
11986 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
11988 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
11990 Set_Discrete_RM_Size (Def_Id);
11991 end Constrain_Enumeration;
11993 ----------------------
11994 -- Constrain_Float --
11995 ----------------------
11997 procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
11998 T : constant Entity_Id := Entity (Subtype_Mark (S));
12004 Set_Ekind (Def_Id, E_Floating_Point_Subtype);
12006 Set_Etype (Def_Id, Base_Type (T));
12007 Set_Size_Info (Def_Id, (T));
12008 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
12010 -- Process the constraint
12012 C := Constraint (S);
12014 -- Digits constraint present
12016 if Nkind (C) = N_Digits_Constraint then
12018 Check_SPARK_Restriction ("digits constraint is not allowed", S);
12019 Check_Restriction (No_Obsolescent_Features, C);
12021 if Warn_On_Obsolescent_Feature then
12023 ("subtype digits constraint is an " &
12024 "obsolescent feature (RM J.3(8))?j?", C);
12027 D := Digits_Expression (C);
12028 Analyze_And_Resolve (D, Any_Integer);
12029 Check_Digits_Expression (D);
12030 Set_Digits_Value (Def_Id, Expr_Value (D));
12032 -- Check that digits value is in range. Obviously we can do this
12033 -- at compile time, but it is strictly a runtime check, and of
12034 -- course there is an ACVC test that checks this!
12036 if Digits_Value (Def_Id) > Digits_Value (T) then
12037 Error_Msg_Uint_1 := Digits_Value (T);
12038 Error_Msg_N ("??digits value is too large, maximum is ^", D);
12040 Make_Raise_Constraint_Error (Sloc (D),
12041 Reason => CE_Range_Check_Failed);
12042 Insert_Action (Declaration_Node (Def_Id), Rais);
12045 C := Range_Constraint (C);
12047 -- No digits constraint present
12050 Set_Digits_Value (Def_Id, Digits_Value (T));
12053 -- Range constraint present
12055 if Nkind (C) = N_Range_Constraint then
12056 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
12058 -- No range constraint present
12061 pragma Assert (No (C));
12062 Set_Scalar_Range (Def_Id, Scalar_Range (T));
12065 Set_Is_Constrained (Def_Id);
12066 end Constrain_Float;
12068 ---------------------
12069 -- Constrain_Index --
12070 ---------------------
12072 procedure Constrain_Index
12075 Related_Nod : Node_Id;
12076 Related_Id : Entity_Id;
12077 Suffix : Character;
12078 Suffix_Index : Nat)
12080 Def_Id : Entity_Id;
12081 R : Node_Id := Empty;
12082 T : constant Entity_Id := Etype (Index);
12085 if Nkind (S) = N_Range
12087 (Nkind (S) = N_Attribute_Reference
12088 and then Attribute_Name (S) = Name_Range)
12090 -- A Range attribute will be transformed into N_Range by Resolve
12096 Process_Range_Expr_In_Decl (R, T, Empty_List);
12098 if not Error_Posted (S)
12100 (Nkind (S) /= N_Range
12101 or else not Covers (T, (Etype (Low_Bound (S))))
12102 or else not Covers (T, (Etype (High_Bound (S)))))
12104 if Base_Type (T) /= Any_Type
12105 and then Etype (Low_Bound (S)) /= Any_Type
12106 and then Etype (High_Bound (S)) /= Any_Type
12108 Error_Msg_N ("range expected", S);
12112 elsif Nkind (S) = N_Subtype_Indication then
12114 -- The parser has verified that this is a discrete indication
12116 Resolve_Discrete_Subtype_Indication (S, T);
12117 R := Range_Expression (Constraint (S));
12119 -- Capture values of bounds and generate temporaries for them if
12120 -- needed, since checks may cause duplication of the expressions
12121 -- which must not be reevaluated.
12123 -- The forced evaluation removes side effects from expressions,
12124 -- which should occur also in SPARK mode. Otherwise, we end up with
12125 -- unexpected insertions of actions at places where this is not
12126 -- supposed to occur, e.g. on default parameters of a call.
12128 if Expander_Active then
12129 Force_Evaluation (Low_Bound (R));
12130 Force_Evaluation (High_Bound (R));
12133 elsif Nkind (S) = N_Discriminant_Association then
12135 -- Syntactically valid in subtype indication
12137 Error_Msg_N ("invalid index constraint", S);
12138 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
12141 -- Subtype_Mark case, no anonymous subtypes to construct
12146 if Is_Entity_Name (S) then
12147 if not Is_Type (Entity (S)) then
12148 Error_Msg_N ("expect subtype mark for index constraint", S);
12150 elsif Base_Type (Entity (S)) /= Base_Type (T) then
12151 Wrong_Type (S, Base_Type (T));
12153 -- Check error of subtype with predicate in index constraint
12156 Bad_Predicated_Subtype_Use
12157 ("subtype& has predicate, not allowed in index constraint",
12164 Error_Msg_N ("invalid index constraint", S);
12165 Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
12171 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
12173 Set_Etype (Def_Id, Base_Type (T));
12175 if Is_Modular_Integer_Type (T) then
12176 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
12178 elsif Is_Integer_Type (T) then
12179 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
12182 Set_Ekind (Def_Id, E_Enumeration_Subtype);
12183 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
12184 Set_First_Literal (Def_Id, First_Literal (T));
12187 Set_Size_Info (Def_Id, (T));
12188 Set_RM_Size (Def_Id, RM_Size (T));
12189 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
12191 Set_Scalar_Range (Def_Id, R);
12193 Set_Etype (S, Def_Id);
12194 Set_Discrete_RM_Size (Def_Id);
12195 end Constrain_Index;
12197 -----------------------
12198 -- Constrain_Integer --
12199 -----------------------
12201 procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
12202 T : constant Entity_Id := Entity (Subtype_Mark (S));
12203 C : constant Node_Id := Constraint (S);
12206 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
12208 if Is_Modular_Integer_Type (T) then
12209 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
12211 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
12214 Set_Etype (Def_Id, Base_Type (T));
12215 Set_Size_Info (Def_Id, (T));
12216 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
12217 Set_Discrete_RM_Size (Def_Id);
12218 end Constrain_Integer;
12220 ------------------------------
12221 -- Constrain_Ordinary_Fixed --
12222 ------------------------------
12224 procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
12225 T : constant Entity_Id := Entity (Subtype_Mark (S));
12231 Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
12232 Set_Etype (Def_Id, Base_Type (T));
12233 Set_Size_Info (Def_Id, (T));
12234 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
12235 Set_Small_Value (Def_Id, Small_Value (T));
12237 -- Process the constraint
12239 C := Constraint (S);
12241 -- Delta constraint present
12243 if Nkind (C) = N_Delta_Constraint then
12245 Check_SPARK_Restriction ("delta constraint is not allowed", S);
12246 Check_Restriction (No_Obsolescent_Features, C);
12248 if Warn_On_Obsolescent_Feature then
12250 ("subtype delta constraint is an " &
12251 "obsolescent feature (RM J.3(7))?j?");
12254 D := Delta_Expression (C);
12255 Analyze_And_Resolve (D, Any_Real);
12256 Check_Delta_Expression (D);
12257 Set_Delta_Value (Def_Id, Expr_Value_R (D));
12259 -- Check that delta value is in range. Obviously we can do this
12260 -- at compile time, but it is strictly a runtime check, and of
12261 -- course there is an ACVC test that checks this!
12263 if Delta_Value (Def_Id) < Delta_Value (T) then
12264 Error_Msg_N ("??delta value is too small", D);
12266 Make_Raise_Constraint_Error (Sloc (D),
12267 Reason => CE_Range_Check_Failed);
12268 Insert_Action (Declaration_Node (Def_Id), Rais);
12271 C := Range_Constraint (C);
12273 -- No delta constraint present
12276 Set_Delta_Value (Def_Id, Delta_Value (T));
12279 -- Range constraint present
12281 if Nkind (C) = N_Range_Constraint then
12282 Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
12284 -- No range constraint present
12287 pragma Assert (No (C));
12288 Set_Scalar_Range (Def_Id, Scalar_Range (T));
12292 Set_Discrete_RM_Size (Def_Id);
12294 -- Unconditionally delay the freeze, since we cannot set size
12295 -- information in all cases correctly until the freeze point.
12297 Set_Has_Delayed_Freeze (Def_Id);
12298 end Constrain_Ordinary_Fixed;
12300 -----------------------
12301 -- Contain_Interface --
12302 -----------------------
12304 function Contain_Interface
12305 (Iface : Entity_Id;
12306 Ifaces : Elist_Id) return Boolean
12308 Iface_Elmt : Elmt_Id;
12311 if Present (Ifaces) then
12312 Iface_Elmt := First_Elmt (Ifaces);
12313 while Present (Iface_Elmt) loop
12314 if Node (Iface_Elmt) = Iface then
12318 Next_Elmt (Iface_Elmt);
12323 end Contain_Interface;
12325 ---------------------------
12326 -- Convert_Scalar_Bounds --
12327 ---------------------------
12329 procedure Convert_Scalar_Bounds
12331 Parent_Type : Entity_Id;
12332 Derived_Type : Entity_Id;
12335 Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
12342 -- Defend against previous errors
12344 if No (Scalar_Range (Derived_Type)) then
12345 Check_Error_Detected;
12349 Lo := Build_Scalar_Bound
12350 (Type_Low_Bound (Derived_Type),
12351 Parent_Type, Implicit_Base);
12353 Hi := Build_Scalar_Bound
12354 (Type_High_Bound (Derived_Type),
12355 Parent_Type, Implicit_Base);
12362 Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
12364 Set_Parent (Rng, N);
12365 Set_Scalar_Range (Derived_Type, Rng);
12367 -- Analyze the bounds
12369 Analyze_And_Resolve (Lo, Implicit_Base);
12370 Analyze_And_Resolve (Hi, Implicit_Base);
12372 -- Analyze the range itself, except that we do not analyze it if
12373 -- the bounds are real literals, and we have a fixed-point type.
12374 -- The reason for this is that we delay setting the bounds in this
12375 -- case till we know the final Small and Size values (see circuit
12376 -- in Freeze.Freeze_Fixed_Point_Type for further details).
12378 if Is_Fixed_Point_Type (Parent_Type)
12379 and then Nkind (Lo) = N_Real_Literal
12380 and then Nkind (Hi) = N_Real_Literal
12384 -- Here we do the analysis of the range
12386 -- Note: we do this manually, since if we do a normal Analyze and
12387 -- Resolve call, there are problems with the conversions used for
12388 -- the derived type range.
12391 Set_Etype (Rng, Implicit_Base);
12392 Set_Analyzed (Rng, True);
12394 end Convert_Scalar_Bounds;
12396 -------------------
12397 -- Copy_And_Swap --
12398 -------------------
12400 procedure Copy_And_Swap (Priv, Full : Entity_Id) is
12402 -- Initialize new full declaration entity by copying the pertinent
12403 -- fields of the corresponding private declaration entity.
12405 -- We temporarily set Ekind to a value appropriate for a type to
12406 -- avoid assert failures in Einfo from checking for setting type
12407 -- attributes on something that is not a type. Ekind (Priv) is an
12408 -- appropriate choice, since it allowed the attributes to be set
12409 -- in the first place. This Ekind value will be modified later.
12411 Set_Ekind (Full, Ekind (Priv));
12413 -- Also set Etype temporarily to Any_Type, again, in the absence
12414 -- of errors, it will be properly reset, and if there are errors,
12415 -- then we want a value of Any_Type to remain.
12417 Set_Etype (Full, Any_Type);
12419 -- Now start copying attributes
12421 Set_Has_Discriminants (Full, Has_Discriminants (Priv));
12423 if Has_Discriminants (Full) then
12424 Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
12425 Set_Stored_Constraint (Full, Stored_Constraint (Priv));
12428 Set_First_Rep_Item (Full, First_Rep_Item (Priv));
12429 Set_Homonym (Full, Homonym (Priv));
12430 Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
12431 Set_Is_Public (Full, Is_Public (Priv));
12432 Set_Is_Pure (Full, Is_Pure (Priv));
12433 Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
12434 Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv));
12435 Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv));
12436 Set_Has_Pragma_Unreferenced_Objects
12437 (Full, Has_Pragma_Unreferenced_Objects
12440 Conditional_Delay (Full, Priv);
12442 if Is_Tagged_Type (Full) then
12443 Set_Direct_Primitive_Operations (Full,
12444 Direct_Primitive_Operations (Priv));
12446 if Is_Base_Type (Priv) then
12447 Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
12451 Set_Is_Volatile (Full, Is_Volatile (Priv));
12452 Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
12453 Set_Scope (Full, Scope (Priv));
12454 Set_Next_Entity (Full, Next_Entity (Priv));
12455 Set_First_Entity (Full, First_Entity (Priv));
12456 Set_Last_Entity (Full, Last_Entity (Priv));
12458 -- If access types have been recorded for later handling, keep them in
12459 -- the full view so that they get handled when the full view freeze
12460 -- node is expanded.
12462 if Present (Freeze_Node (Priv))
12463 and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
12465 Ensure_Freeze_Node (Full);
12466 Set_Access_Types_To_Process
12467 (Freeze_Node (Full),
12468 Access_Types_To_Process (Freeze_Node (Priv)));
12471 -- Swap the two entities. Now Private is the full type entity and Full
12472 -- is the private one. They will be swapped back at the end of the
12473 -- private part. This swapping ensures that the entity that is visible
12474 -- in the private part is the full declaration.
12476 Exchange_Entities (Priv, Full);
12477 Append_Entity (Full, Scope (Full));
12480 -------------------------------------
12481 -- Copy_Array_Base_Type_Attributes --
12482 -------------------------------------
12484 procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
12486 Set_Component_Alignment (T1, Component_Alignment (T2));
12487 Set_Component_Type (T1, Component_Type (T2));
12488 Set_Component_Size (T1, Component_Size (T2));
12489 Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
12490 Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
12491 Set_Has_Task (T1, Has_Task (T2));
12492 Set_Is_Packed (T1, Is_Packed (T2));
12493 Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
12494 Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
12495 Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
12496 end Copy_Array_Base_Type_Attributes;
12498 -----------------------------------
12499 -- Copy_Array_Subtype_Attributes --
12500 -----------------------------------
12502 procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
12504 Set_Size_Info (T1, T2);
12506 Set_First_Index (T1, First_Index (T2));
12507 Set_Is_Aliased (T1, Is_Aliased (T2));
12508 Set_Is_Volatile (T1, Is_Volatile (T2));
12509 Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
12510 Set_Is_Constrained (T1, Is_Constrained (T2));
12511 Set_Depends_On_Private (T1, Has_Private_Component (T2));
12512 Set_First_Rep_Item (T1, First_Rep_Item (T2));
12513 Set_Convention (T1, Convention (T2));
12514 Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
12515 Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
12516 Set_Packed_Array_Type (T1, Packed_Array_Type (T2));
12517 end Copy_Array_Subtype_Attributes;
12519 -----------------------------------
12520 -- Create_Constrained_Components --
12521 -----------------------------------
12523 procedure Create_Constrained_Components
12525 Decl_Node : Node_Id;
12527 Constraints : Elist_Id)
12529 Loc : constant Source_Ptr := Sloc (Subt);
12530 Comp_List : constant Elist_Id := New_Elmt_List;
12531 Parent_Type : constant Entity_Id := Etype (Typ);
12532 Assoc_List : constant List_Id := New_List;
12533 Discr_Val : Elmt_Id;
12537 Is_Static : Boolean := True;
12539 procedure Collect_Fixed_Components (Typ : Entity_Id);
12540 -- Collect parent type components that do not appear in a variant part
12542 procedure Create_All_Components;
12543 -- Iterate over Comp_List to create the components of the subtype
12545 function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
12546 -- Creates a new component from Old_Compon, copying all the fields from
12547 -- it, including its Etype, inserts the new component in the Subt entity
12548 -- chain and returns the new component.
12550 function Is_Variant_Record (T : Entity_Id) return Boolean;
12551 -- If true, and discriminants are static, collect only components from
12552 -- variants selected by discriminant values.
12554 ------------------------------
12555 -- Collect_Fixed_Components --
12556 ------------------------------
12558 procedure Collect_Fixed_Components (Typ : Entity_Id) is
12560 -- Build association list for discriminants, and find components of the
12561 -- variant part selected by the values of the discriminants.
12563 Old_C := First_Discriminant (Typ);
12564 Discr_Val := First_Elmt (Constraints);
12565 while Present (Old_C) loop
12566 Append_To (Assoc_List,
12567 Make_Component_Association (Loc,
12568 Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
12569 Expression => New_Copy (Node (Discr_Val))));
12571 Next_Elmt (Discr_Val);
12572 Next_Discriminant (Old_C);
12575 -- The tag and the possible parent component are unconditionally in
12578 if Is_Tagged_Type (Typ)
12579 or else Has_Controlled_Component (Typ)
12581 Old_C := First_Component (Typ);
12582 while Present (Old_C) loop
12583 if Nam_In (Chars (Old_C), Name_uTag, Name_uParent) then
12584 Append_Elmt (Old_C, Comp_List);
12587 Next_Component (Old_C);
12590 end Collect_Fixed_Components;
12592 ---------------------------
12593 -- Create_All_Components --
12594 ---------------------------
12596 procedure Create_All_Components is
12600 Comp := First_Elmt (Comp_List);
12601 while Present (Comp) loop
12602 Old_C := Node (Comp);
12603 New_C := Create_Component (Old_C);
12607 Constrain_Component_Type
12608 (Old_C, Subt, Decl_Node, Typ, Constraints));
12609 Set_Is_Public (New_C, Is_Public (Subt));
12613 end Create_All_Components;
12615 ----------------------
12616 -- Create_Component --
12617 ----------------------
12619 function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
12620 New_Compon : constant Entity_Id := New_Copy (Old_Compon);
12623 if Ekind (Old_Compon) = E_Discriminant
12624 and then Is_Completely_Hidden (Old_Compon)
12626 -- This is a shadow discriminant created for a discriminant of
12627 -- the parent type, which needs to be present in the subtype.
12628 -- Give the shadow discriminant an internal name that cannot
12629 -- conflict with that of visible components.
12631 Set_Chars (New_Compon, New_Internal_Name ('C'));
12634 -- Set the parent so we have a proper link for freezing etc. This is
12635 -- not a real parent pointer, since of course our parent does not own
12636 -- up to us and reference us, we are an illegitimate child of the
12637 -- original parent!
12639 Set_Parent (New_Compon, Parent (Old_Compon));
12641 -- If the old component's Esize was already determined and is a
12642 -- static value, then the new component simply inherits it. Otherwise
12643 -- the old component's size may require run-time determination, but
12644 -- the new component's size still might be statically determinable
12645 -- (if, for example it has a static constraint). In that case we want
12646 -- Layout_Type to recompute the component's size, so we reset its
12647 -- size and positional fields.
12649 if Frontend_Layout_On_Target
12650 and then not Known_Static_Esize (Old_Compon)
12652 Set_Esize (New_Compon, Uint_0);
12653 Init_Normalized_First_Bit (New_Compon);
12654 Init_Normalized_Position (New_Compon);
12655 Init_Normalized_Position_Max (New_Compon);
12658 -- We do not want this node marked as Comes_From_Source, since
12659 -- otherwise it would get first class status and a separate cross-
12660 -- reference line would be generated. Illegitimate children do not
12661 -- rate such recognition.
12663 Set_Comes_From_Source (New_Compon, False);
12665 -- But it is a real entity, and a birth certificate must be properly
12666 -- registered by entering it into the entity list.
12668 Enter_Name (New_Compon);
12671 end Create_Component;
12673 -----------------------
12674 -- Is_Variant_Record --
12675 -----------------------
12677 function Is_Variant_Record (T : Entity_Id) return Boolean is
12679 return Nkind (Parent (T)) = N_Full_Type_Declaration
12680 and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
12681 and then Present (Component_List (Type_Definition (Parent (T))))
12684 (Variant_Part (Component_List (Type_Definition (Parent (T)))));
12685 end Is_Variant_Record;
12687 -- Start of processing for Create_Constrained_Components
12690 pragma Assert (Subt /= Base_Type (Subt));
12691 pragma Assert (Typ = Base_Type (Typ));
12693 Set_First_Entity (Subt, Empty);
12694 Set_Last_Entity (Subt, Empty);
12696 -- Check whether constraint is fully static, in which case we can
12697 -- optimize the list of components.
12699 Discr_Val := First_Elmt (Constraints);
12700 while Present (Discr_Val) loop
12701 if not Is_OK_Static_Expression (Node (Discr_Val)) then
12702 Is_Static := False;
12706 Next_Elmt (Discr_Val);
12709 Set_Has_Static_Discriminants (Subt, Is_Static);
12713 -- Inherit the discriminants of the parent type
12715 Add_Discriminants : declare
12721 Old_C := First_Discriminant (Typ);
12723 while Present (Old_C) loop
12724 Num_Disc := Num_Disc + 1;
12725 New_C := Create_Component (Old_C);
12726 Set_Is_Public (New_C, Is_Public (Subt));
12727 Next_Discriminant (Old_C);
12730 -- For an untagged derived subtype, the number of discriminants may
12731 -- be smaller than the number of inherited discriminants, because
12732 -- several of them may be renamed by a single new discriminant or
12733 -- constrained. In this case, add the hidden discriminants back into
12734 -- the subtype, because they need to be present if the optimizer of
12735 -- the GCC 4.x back-end decides to break apart assignments between
12736 -- objects using the parent view into member-wise assignments.
12740 if Is_Derived_Type (Typ)
12741 and then not Is_Tagged_Type (Typ)
12743 Old_C := First_Stored_Discriminant (Typ);
12745 while Present (Old_C) loop
12746 Num_Gird := Num_Gird + 1;
12747 Next_Stored_Discriminant (Old_C);
12751 if Num_Gird > Num_Disc then
12753 -- Find out multiple uses of new discriminants, and add hidden
12754 -- components for the extra renamed discriminants. We recognize
12755 -- multiple uses through the Corresponding_Discriminant of a
12756 -- new discriminant: if it constrains several old discriminants,
12757 -- this field points to the last one in the parent type. The
12758 -- stored discriminants of the derived type have the same name
12759 -- as those of the parent.
12763 New_Discr : Entity_Id;
12764 Old_Discr : Entity_Id;
12767 Constr := First_Elmt (Stored_Constraint (Typ));
12768 Old_Discr := First_Stored_Discriminant (Typ);
12769 while Present (Constr) loop
12770 if Is_Entity_Name (Node (Constr))
12771 and then Ekind (Entity (Node (Constr))) = E_Discriminant
12773 New_Discr := Entity (Node (Constr));
12775 if Chars (Corresponding_Discriminant (New_Discr)) /=
12778 -- The new discriminant has been used to rename a
12779 -- subsequent old discriminant. Introduce a shadow
12780 -- component for the current old discriminant.
12782 New_C := Create_Component (Old_Discr);
12783 Set_Original_Record_Component (New_C, Old_Discr);
12787 -- The constraint has eliminated the old discriminant.
12788 -- Introduce a shadow component.
12790 New_C := Create_Component (Old_Discr);
12791 Set_Original_Record_Component (New_C, Old_Discr);
12794 Next_Elmt (Constr);
12795 Next_Stored_Discriminant (Old_Discr);
12799 end Add_Discriminants;
12802 and then Is_Variant_Record (Typ)
12804 Collect_Fixed_Components (Typ);
12806 Gather_Components (
12808 Component_List (Type_Definition (Parent (Typ))),
12809 Governed_By => Assoc_List,
12811 Report_Errors => Errors);
12812 pragma Assert (not Errors);
12814 Create_All_Components;
12816 -- If the subtype declaration is created for a tagged type derivation
12817 -- with constraints, we retrieve the record definition of the parent
12818 -- type to select the components of the proper variant.
12821 and then Is_Tagged_Type (Typ)
12822 and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
12824 Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
12825 and then Is_Variant_Record (Parent_Type)
12827 Collect_Fixed_Components (Typ);
12829 Gather_Components (
12831 Component_List (Type_Definition (Parent (Parent_Type))),
12832 Governed_By => Assoc_List,
12834 Report_Errors => Errors);
12835 pragma Assert (not Errors);
12837 -- If the tagged derivation has a type extension, collect all the
12838 -- new components therein.
12841 (Record_Extension_Part (Type_Definition (Parent (Typ))))
12843 Old_C := First_Component (Typ);
12844 while Present (Old_C) loop
12845 if Original_Record_Component (Old_C) = Old_C
12846 and then Chars (Old_C) /= Name_uTag
12847 and then Chars (Old_C) /= Name_uParent
12849 Append_Elmt (Old_C, Comp_List);
12852 Next_Component (Old_C);
12856 Create_All_Components;
12859 -- If discriminants are not static, or if this is a multi-level type
12860 -- extension, we have to include all components of the parent type.
12862 Old_C := First_Component (Typ);
12863 while Present (Old_C) loop
12864 New_C := Create_Component (Old_C);
12868 Constrain_Component_Type
12869 (Old_C, Subt, Decl_Node, Typ, Constraints));
12870 Set_Is_Public (New_C, Is_Public (Subt));
12872 Next_Component (Old_C);
12877 end Create_Constrained_Components;
12879 ------------------------------------------
12880 -- Decimal_Fixed_Point_Type_Declaration --
12881 ------------------------------------------
12883 procedure Decimal_Fixed_Point_Type_Declaration
12887 Loc : constant Source_Ptr := Sloc (Def);
12888 Digs_Expr : constant Node_Id := Digits_Expression (Def);
12889 Delta_Expr : constant Node_Id := Delta_Expression (Def);
12890 Implicit_Base : Entity_Id;
12897 Check_SPARK_Restriction
12898 ("decimal fixed point type is not allowed", Def);
12899 Check_Restriction (No_Fixed_Point, Def);
12901 -- Create implicit base type
12904 Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
12905 Set_Etype (Implicit_Base, Implicit_Base);
12907 -- Analyze and process delta expression
12909 Analyze_And_Resolve (Delta_Expr, Universal_Real);
12911 Check_Delta_Expression (Delta_Expr);
12912 Delta_Val := Expr_Value_R (Delta_Expr);
12914 -- Check delta is power of 10, and determine scale value from it
12920 Scale_Val := Uint_0;
12923 if Val < Ureal_1 then
12924 while Val < Ureal_1 loop
12925 Val := Val * Ureal_10;
12926 Scale_Val := Scale_Val + 1;
12929 if Scale_Val > 18 then
12930 Error_Msg_N ("scale exceeds maximum value of 18", Def);
12931 Scale_Val := UI_From_Int (+18);
12935 while Val > Ureal_1 loop
12936 Val := Val / Ureal_10;
12937 Scale_Val := Scale_Val - 1;
12940 if Scale_Val < -18 then
12941 Error_Msg_N ("scale is less than minimum value of -18", Def);
12942 Scale_Val := UI_From_Int (-18);
12946 if Val /= Ureal_1 then
12947 Error_Msg_N ("delta expression must be a power of 10", Def);
12948 Delta_Val := Ureal_10 ** (-Scale_Val);
12952 -- Set delta, scale and small (small = delta for decimal type)
12954 Set_Delta_Value (Implicit_Base, Delta_Val);
12955 Set_Scale_Value (Implicit_Base, Scale_Val);
12956 Set_Small_Value (Implicit_Base, Delta_Val);
12958 -- Analyze and process digits expression
12960 Analyze_And_Resolve (Digs_Expr, Any_Integer);
12961 Check_Digits_Expression (Digs_Expr);
12962 Digs_Val := Expr_Value (Digs_Expr);
12964 if Digs_Val > 18 then
12965 Digs_Val := UI_From_Int (+18);
12966 Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
12969 Set_Digits_Value (Implicit_Base, Digs_Val);
12970 Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
12972 -- Set range of base type from digits value for now. This will be
12973 -- expanded to represent the true underlying base range by Freeze.
12975 Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
12977 -- Note: We leave size as zero for now, size will be set at freeze
12978 -- time. We have to do this for ordinary fixed-point, because the size
12979 -- depends on the specified small, and we might as well do the same for
12980 -- decimal fixed-point.
12982 pragma Assert (Esize (Implicit_Base) = Uint_0);
12984 -- If there are bounds given in the declaration use them as the
12985 -- bounds of the first named subtype.
12987 if Present (Real_Range_Specification (Def)) then
12989 RRS : constant Node_Id := Real_Range_Specification (Def);
12990 Low : constant Node_Id := Low_Bound (RRS);
12991 High : constant Node_Id := High_Bound (RRS);
12996 Analyze_And_Resolve (Low, Any_Real);
12997 Analyze_And_Resolve (High, Any_Real);
12998 Check_Real_Bound (Low);
12999 Check_Real_Bound (High);
13000 Low_Val := Expr_Value_R (Low);
13001 High_Val := Expr_Value_R (High);
13003 if Low_Val < (-Bound_Val) then
13005 ("range low bound too small for digits value", Low);
13006 Low_Val := -Bound_Val;
13009 if High_Val > Bound_Val then
13011 ("range high bound too large for digits value", High);
13012 High_Val := Bound_Val;
13015 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
13018 -- If no explicit range, use range that corresponds to given
13019 -- digits value. This will end up as the final range for the
13023 Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
13026 -- Complete entity for first subtype
13028 Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
13029 Set_Etype (T, Implicit_Base);
13030 Set_Size_Info (T, Implicit_Base);
13031 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
13032 Set_Digits_Value (T, Digs_Val);
13033 Set_Delta_Value (T, Delta_Val);
13034 Set_Small_Value (T, Delta_Val);
13035 Set_Scale_Value (T, Scale_Val);
13036 Set_Is_Constrained (T);
13037 end Decimal_Fixed_Point_Type_Declaration;
13039 -----------------------------------
13040 -- Derive_Progenitor_Subprograms --
13041 -----------------------------------
13043 procedure Derive_Progenitor_Subprograms
13044 (Parent_Type : Entity_Id;
13045 Tagged_Type : Entity_Id)
13050 Iface_Elmt : Elmt_Id;
13051 Iface_Subp : Entity_Id;
13052 New_Subp : Entity_Id := Empty;
13053 Prim_Elmt : Elmt_Id;
13058 pragma Assert (Ada_Version >= Ada_2005
13059 and then Is_Record_Type (Tagged_Type)
13060 and then Is_Tagged_Type (Tagged_Type)
13061 and then Has_Interfaces (Tagged_Type));
13063 -- Step 1: Transfer to the full-view primitives associated with the
13064 -- partial-view that cover interface primitives. Conceptually this
13065 -- work should be done later by Process_Full_View; done here to
13066 -- simplify its implementation at later stages. It can be safely
13067 -- done here because interfaces must be visible in the partial and
13068 -- private view (RM 7.3(7.3/2)).
13070 -- Small optimization: This work is only required if the parent may
13071 -- have entities whose Alias attribute reference an interface primitive.
13072 -- Such a situation may occur if the parent is an abstract type and the
13073 -- primitive has not been yet overridden or if the parent is a generic
13074 -- formal type covering interfaces.
13076 -- If the tagged type is not abstract, it cannot have abstract
13077 -- primitives (the only entities in the list of primitives of
13078 -- non-abstract tagged types that can reference abstract primitives
13079 -- through its Alias attribute are the internal entities that have
13080 -- attribute Interface_Alias, and these entities are generated later
13081 -- by Add_Internal_Interface_Entities).
13083 if In_Private_Part (Current_Scope)
13084 and then (Is_Abstract_Type (Parent_Type)
13086 Is_Generic_Type (Parent_Type))
13088 Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
13089 while Present (Elmt) loop
13090 Subp := Node (Elmt);
13092 -- At this stage it is not possible to have entities in the list
13093 -- of primitives that have attribute Interface_Alias.
13095 pragma Assert (No (Interface_Alias (Subp)));
13097 Typ := Find_Dispatching_Type (Ultimate_Alias (Subp));
13099 if Is_Interface (Typ) then
13100 E := Find_Primitive_Covering_Interface
13101 (Tagged_Type => Tagged_Type,
13102 Iface_Prim => Subp);
13105 and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ
13107 Replace_Elmt (Elmt, E);
13108 Remove_Homonym (Subp);
13116 -- Step 2: Add primitives of progenitors that are not implemented by
13117 -- parents of Tagged_Type.
13119 if Present (Interfaces (Base_Type (Tagged_Type))) then
13120 Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type)));
13121 while Present (Iface_Elmt) loop
13122 Iface := Node (Iface_Elmt);
13124 Prim_Elmt := First_Elmt (Primitive_Operations (Iface));
13125 while Present (Prim_Elmt) loop
13126 Iface_Subp := Node (Prim_Elmt);
13128 -- Exclude derivation of predefined primitives except those
13129 -- that come from source, or are inherited from one that comes
13130 -- from source. Required to catch declarations of equality
13131 -- operators of interfaces. For example:
13133 -- type Iface is interface;
13134 -- function "=" (Left, Right : Iface) return Boolean;
13136 if not Is_Predefined_Dispatching_Operation (Iface_Subp)
13137 or else Comes_From_Source (Ultimate_Alias (Iface_Subp))
13139 E := Find_Primitive_Covering_Interface
13140 (Tagged_Type => Tagged_Type,
13141 Iface_Prim => Iface_Subp);
13143 -- If not found we derive a new primitive leaving its alias
13144 -- attribute referencing the interface primitive.
13148 (New_Subp, Iface_Subp, Tagged_Type, Iface);
13150 -- Ada 2012 (AI05-0197): If the covering primitive's name
13151 -- differs from the name of the interface primitive then it
13152 -- is a private primitive inherited from a parent type. In
13153 -- such case, given that Tagged_Type covers the interface,
13154 -- the inherited private primitive becomes visible. For such
13155 -- purpose we add a new entity that renames the inherited
13156 -- private primitive.
13158 elsif Chars (E) /= Chars (Iface_Subp) then
13159 pragma Assert (Has_Suffix (E, 'P'));
13161 (New_Subp, Iface_Subp, Tagged_Type, Iface);
13162 Set_Alias (New_Subp, E);
13163 Set_Is_Abstract_Subprogram (New_Subp,
13164 Is_Abstract_Subprogram (E));
13166 -- Propagate to the full view interface entities associated
13167 -- with the partial view.
13169 elsif In_Private_Part (Current_Scope)
13170 and then Present (Alias (E))
13171 and then Alias (E) = Iface_Subp
13173 List_Containing (Parent (E)) /=
13174 Private_Declarations
13176 (Unit_Declaration_Node (Current_Scope)))
13178 Append_Elmt (E, Primitive_Operations (Tagged_Type));
13182 Next_Elmt (Prim_Elmt);
13185 Next_Elmt (Iface_Elmt);
13188 end Derive_Progenitor_Subprograms;
13190 -----------------------
13191 -- Derive_Subprogram --
13192 -----------------------
13194 procedure Derive_Subprogram
13195 (New_Subp : in out Entity_Id;
13196 Parent_Subp : Entity_Id;
13197 Derived_Type : Entity_Id;
13198 Parent_Type : Entity_Id;
13199 Actual_Subp : Entity_Id := Empty)
13201 Formal : Entity_Id;
13202 -- Formal parameter of parent primitive operation
13204 Formal_Of_Actual : Entity_Id;
13205 -- Formal parameter of actual operation, when the derivation is to
13206 -- create a renaming for a primitive operation of an actual in an
13209 New_Formal : Entity_Id;
13210 -- Formal of inherited operation
13212 Visible_Subp : Entity_Id := Parent_Subp;
13214 function Is_Private_Overriding return Boolean;
13215 -- If Subp is a private overriding of a visible operation, the inherited
13216 -- operation derives from the overridden op (even though its body is the
13217 -- overriding one) and the inherited operation is visible now. See
13218 -- sem_disp to see the full details of the handling of the overridden
13219 -- subprogram, which is removed from the list of primitive operations of
13220 -- the type. The overridden subprogram is saved locally in Visible_Subp,
13221 -- and used to diagnose abstract operations that need overriding in the
13224 procedure Replace_Type (Id, New_Id : Entity_Id);
13225 -- When the type is an anonymous access type, create a new access type
13226 -- designating the derived type.
13228 procedure Set_Derived_Name;
13229 -- This procedure sets the appropriate Chars name for New_Subp. This
13230 -- is normally just a copy of the parent name. An exception arises for
13231 -- type support subprograms, where the name is changed to reflect the
13232 -- name of the derived type, e.g. if type foo is derived from type bar,
13233 -- then a procedure barDA is derived with a name fooDA.
13235 ---------------------------
13236 -- Is_Private_Overriding --
13237 ---------------------------
13239 function Is_Private_Overriding return Boolean is
13243 -- If the parent is not a dispatching operation there is no
13244 -- need to investigate overridings
13246 if not Is_Dispatching_Operation (Parent_Subp) then
13250 -- The visible operation that is overridden is a homonym of the
13251 -- parent subprogram. We scan the homonym chain to find the one
13252 -- whose alias is the subprogram we are deriving.
13254 Prev := Current_Entity (Parent_Subp);
13255 while Present (Prev) loop
13256 if Ekind (Prev) = Ekind (Parent_Subp)
13257 and then Alias (Prev) = Parent_Subp
13258 and then Scope (Parent_Subp) = Scope (Prev)
13259 and then not Is_Hidden (Prev)
13261 Visible_Subp := Prev;
13265 Prev := Homonym (Prev);
13269 end Is_Private_Overriding;
13275 procedure Replace_Type (Id, New_Id : Entity_Id) is
13276 Acc_Type : Entity_Id;
13277 Par : constant Node_Id := Parent (Derived_Type);
13280 -- When the type is an anonymous access type, create a new access
13281 -- type designating the derived type. This itype must be elaborated
13282 -- at the point of the derivation, not on subsequent calls that may
13283 -- be out of the proper scope for Gigi, so we insert a reference to
13284 -- it after the derivation.
13286 if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
13288 Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
13291 if Ekind (Desig_Typ) = E_Record_Type_With_Private
13292 and then Present (Full_View (Desig_Typ))
13293 and then not Is_Private_Type (Parent_Type)
13295 Desig_Typ := Full_View (Desig_Typ);
13298 if Base_Type (Desig_Typ) = Base_Type (Parent_Type)
13300 -- Ada 2005 (AI-251): Handle also derivations of abstract
13301 -- interface primitives.
13303 or else (Is_Interface (Desig_Typ)
13304 and then not Is_Class_Wide_Type (Desig_Typ))
13306 Acc_Type := New_Copy (Etype (Id));
13307 Set_Etype (Acc_Type, Acc_Type);
13308 Set_Scope (Acc_Type, New_Subp);
13310 -- Compute size of anonymous access type
13312 if Is_Array_Type (Desig_Typ)
13313 and then not Is_Constrained (Desig_Typ)
13315 Init_Size (Acc_Type, 2 * System_Address_Size);
13317 Init_Size (Acc_Type, System_Address_Size);
13320 Init_Alignment (Acc_Type);
13321 Set_Directly_Designated_Type (Acc_Type, Derived_Type);
13323 Set_Etype (New_Id, Acc_Type);
13324 Set_Scope (New_Id, New_Subp);
13326 -- Create a reference to it
13327 Build_Itype_Reference (Acc_Type, Parent (Derived_Type));
13330 Set_Etype (New_Id, Etype (Id));
13334 elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
13336 (Ekind (Etype (Id)) = E_Record_Type_With_Private
13337 and then Present (Full_View (Etype (Id)))
13339 Base_Type (Full_View (Etype (Id))) = Base_Type (Parent_Type))
13341 -- Constraint checks on formals are generated during expansion,
13342 -- based on the signature of the original subprogram. The bounds
13343 -- of the derived type are not relevant, and thus we can use
13344 -- the base type for the formals. However, the return type may be
13345 -- used in a context that requires that the proper static bounds
13346 -- be used (a case statement, for example) and for those cases
13347 -- we must use the derived type (first subtype), not its base.
13349 -- If the derived_type_definition has no constraints, we know that
13350 -- the derived type has the same constraints as the first subtype
13351 -- of the parent, and we can also use it rather than its base,
13352 -- which can lead to more efficient code.
13354 if Etype (Id) = Parent_Type then
13355 if Is_Scalar_Type (Parent_Type)
13357 Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
13359 Set_Etype (New_Id, Derived_Type);
13361 elsif Nkind (Par) = N_Full_Type_Declaration
13363 Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
13366 (Subtype_Indication (Type_Definition (Par)))
13368 Set_Etype (New_Id, Derived_Type);
13371 Set_Etype (New_Id, Base_Type (Derived_Type));
13375 Set_Etype (New_Id, Base_Type (Derived_Type));
13379 Set_Etype (New_Id, Etype (Id));
13383 ----------------------
13384 -- Set_Derived_Name --
13385 ----------------------
13387 procedure Set_Derived_Name is
13388 Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
13390 if Nm = TSS_Null then
13391 Set_Chars (New_Subp, Chars (Parent_Subp));
13393 Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
13395 end Set_Derived_Name;
13397 -- Start of processing for Derive_Subprogram
13401 New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
13402 Set_Ekind (New_Subp, Ekind (Parent_Subp));
13403 Set_Contract (New_Subp, Make_Contract (Sloc (New_Subp)));
13405 -- Check whether the inherited subprogram is a private operation that
13406 -- should be inherited but not yet made visible. Such subprograms can
13407 -- become visible at a later point (e.g., the private part of a public
13408 -- child unit) via Declare_Inherited_Private_Subprograms. If the
13409 -- following predicate is true, then this is not such a private
13410 -- operation and the subprogram simply inherits the name of the parent
13411 -- subprogram. Note the special check for the names of controlled
13412 -- operations, which are currently exempted from being inherited with
13413 -- a hidden name because they must be findable for generation of
13414 -- implicit run-time calls.
13416 if not Is_Hidden (Parent_Subp)
13417 or else Is_Internal (Parent_Subp)
13418 or else Is_Private_Overriding
13419 or else Is_Internal_Name (Chars (Parent_Subp))
13420 or else Nam_In (Chars (Parent_Subp), Name_Initialize,
13426 -- An inherited dispatching equality will be overridden by an internally
13427 -- generated one, or by an explicit one, so preserve its name and thus
13428 -- its entry in the dispatch table. Otherwise, if Parent_Subp is a
13429 -- private operation it may become invisible if the full view has
13430 -- progenitors, and the dispatch table will be malformed.
13431 -- We check that the type is limited to handle the anomalous declaration
13432 -- of Limited_Controlled, which is derived from a non-limited type, and
13433 -- which is handled specially elsewhere as well.
13435 elsif Chars (Parent_Subp) = Name_Op_Eq
13436 and then Is_Dispatching_Operation (Parent_Subp)
13437 and then Etype (Parent_Subp) = Standard_Boolean
13438 and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp)))
13440 Etype (First_Formal (Parent_Subp)) =
13441 Etype (Next_Formal (First_Formal (Parent_Subp)))
13445 -- If parent is hidden, this can be a regular derivation if the
13446 -- parent is immediately visible in a non-instantiating context,
13447 -- or if we are in the private part of an instance. This test
13448 -- should still be refined ???
13450 -- The test for In_Instance_Not_Visible avoids inheriting the derived
13451 -- operation as a non-visible operation in cases where the parent
13452 -- subprogram might not be visible now, but was visible within the
13453 -- original generic, so it would be wrong to make the inherited
13454 -- subprogram non-visible now. (Not clear if this test is fully
13455 -- correct; are there any cases where we should declare the inherited
13456 -- operation as not visible to avoid it being overridden, e.g., when
13457 -- the parent type is a generic actual with private primitives ???)
13459 -- (they should be treated the same as other private inherited
13460 -- subprograms, but it's not clear how to do this cleanly). ???
13462 elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
13463 and then Is_Immediately_Visible (Parent_Subp)
13464 and then not In_Instance)
13465 or else In_Instance_Not_Visible
13469 -- Ada 2005 (AI-251): Regular derivation if the parent subprogram
13470 -- overrides an interface primitive because interface primitives
13471 -- must be visible in the partial view of the parent (RM 7.3 (7.3/2))
13473 elsif Ada_Version >= Ada_2005
13474 and then Is_Dispatching_Operation (Parent_Subp)
13475 and then Covers_Some_Interface (Parent_Subp)
13479 -- Otherwise, the type is inheriting a private operation, so enter
13480 -- it with a special name so it can't be overridden.
13483 Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
13486 Set_Parent (New_Subp, Parent (Derived_Type));
13488 if Present (Actual_Subp) then
13489 Replace_Type (Actual_Subp, New_Subp);
13491 Replace_Type (Parent_Subp, New_Subp);
13494 Conditional_Delay (New_Subp, Parent_Subp);
13496 -- If we are creating a renaming for a primitive operation of an
13497 -- actual of a generic derived type, we must examine the signature
13498 -- of the actual primitive, not that of the generic formal, which for
13499 -- example may be an interface. However the name and initial value
13500 -- of the inherited operation are those of the formal primitive.
13502 Formal := First_Formal (Parent_Subp);
13504 if Present (Actual_Subp) then
13505 Formal_Of_Actual := First_Formal (Actual_Subp);
13507 Formal_Of_Actual := Empty;
13510 while Present (Formal) loop
13511 New_Formal := New_Copy (Formal);
13513 -- Normally we do not go copying parents, but in the case of
13514 -- formals, we need to link up to the declaration (which is the
13515 -- parameter specification), and it is fine to link up to the
13516 -- original formal's parameter specification in this case.
13518 Set_Parent (New_Formal, Parent (Formal));
13519 Append_Entity (New_Formal, New_Subp);
13521 if Present (Formal_Of_Actual) then
13522 Replace_Type (Formal_Of_Actual, New_Formal);
13523 Next_Formal (Formal_Of_Actual);
13525 Replace_Type (Formal, New_Formal);
13528 Next_Formal (Formal);
13531 -- If this derivation corresponds to a tagged generic actual, then
13532 -- primitive operations rename those of the actual. Otherwise the
13533 -- primitive operations rename those of the parent type, If the parent
13534 -- renames an intrinsic operator, so does the new subprogram. We except
13535 -- concatenation, which is always properly typed, and does not get
13536 -- expanded as other intrinsic operations.
13538 if No (Actual_Subp) then
13539 if Is_Intrinsic_Subprogram (Parent_Subp) then
13540 Set_Is_Intrinsic_Subprogram (New_Subp);
13542 if Present (Alias (Parent_Subp))
13543 and then Chars (Parent_Subp) /= Name_Op_Concat
13545 Set_Alias (New_Subp, Alias (Parent_Subp));
13547 Set_Alias (New_Subp, Parent_Subp);
13551 Set_Alias (New_Subp, Parent_Subp);
13555 Set_Alias (New_Subp, Actual_Subp);
13558 -- Derived subprograms of a tagged type must inherit the convention
13559 -- of the parent subprogram (a requirement of AI-117). Derived
13560 -- subprograms of untagged types simply get convention Ada by default.
13562 -- If the derived type is a tagged generic formal type with unknown
13563 -- discriminants, its convention is intrinsic (RM 6.3.1 (8)).
13565 -- However, if the type is derived from a generic formal, the further
13566 -- inherited subprogram has the convention of the non-generic ancestor.
13567 -- Otherwise there would be no way to override the operation.
13568 -- (This is subject to forthcoming ARG discussions).
13570 if Is_Tagged_Type (Derived_Type) then
13571 if Is_Generic_Type (Derived_Type)
13572 and then Has_Unknown_Discriminants (Derived_Type)
13574 Set_Convention (New_Subp, Convention_Intrinsic);
13577 if Is_Generic_Type (Parent_Type)
13578 and then Has_Unknown_Discriminants (Parent_Type)
13580 Set_Convention (New_Subp, Convention (Alias (Parent_Subp)));
13582 Set_Convention (New_Subp, Convention (Parent_Subp));
13587 -- Predefined controlled operations retain their name even if the parent
13588 -- is hidden (see above), but they are not primitive operations if the
13589 -- ancestor is not visible, for example if the parent is a private
13590 -- extension completed with a controlled extension. Note that a full
13591 -- type that is controlled can break privacy: the flag Is_Controlled is
13592 -- set on both views of the type.
13594 if Is_Controlled (Parent_Type)
13595 and then Nam_In (Chars (Parent_Subp), Name_Initialize,
13598 and then Is_Hidden (Parent_Subp)
13599 and then not Is_Visibly_Controlled (Parent_Type)
13601 Set_Is_Hidden (New_Subp);
13604 Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
13605 Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
13607 if Ekind (Parent_Subp) = E_Procedure then
13608 Set_Is_Valued_Procedure
13609 (New_Subp, Is_Valued_Procedure (Parent_Subp));
13611 Set_Has_Controlling_Result
13612 (New_Subp, Has_Controlling_Result (Parent_Subp));
13615 -- No_Return must be inherited properly. If this is overridden in the
13616 -- case of a dispatching operation, then a check is made in Sem_Disp
13617 -- that the overriding operation is also No_Return (no such check is
13618 -- required for the case of non-dispatching operation.
13620 Set_No_Return (New_Subp, No_Return (Parent_Subp));
13622 -- A derived function with a controlling result is abstract. If the
13623 -- Derived_Type is a nonabstract formal generic derived type, then
13624 -- inherited operations are not abstract: the required check is done at
13625 -- instantiation time. If the derivation is for a generic actual, the
13626 -- function is not abstract unless the actual is.
13628 if Is_Generic_Type (Derived_Type)
13629 and then not Is_Abstract_Type (Derived_Type)
13633 -- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract"
13634 -- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2).
13636 elsif Ada_Version >= Ada_2005
13637 and then (Is_Abstract_Subprogram (Alias (New_Subp))
13638 or else (Is_Tagged_Type (Derived_Type)
13639 and then Etype (New_Subp) = Derived_Type
13640 and then not Is_Null_Extension (Derived_Type))
13641 or else (Is_Tagged_Type (Derived_Type)
13642 and then Ekind (Etype (New_Subp)) =
13643 E_Anonymous_Access_Type
13644 and then Designated_Type (Etype (New_Subp)) =
13646 and then not Is_Null_Extension (Derived_Type)))
13647 and then No (Actual_Subp)
13649 if not Is_Tagged_Type (Derived_Type)
13650 or else Is_Abstract_Type (Derived_Type)
13651 or else Is_Abstract_Subprogram (Alias (New_Subp))
13653 Set_Is_Abstract_Subprogram (New_Subp);
13655 Set_Requires_Overriding (New_Subp);
13658 elsif Ada_Version < Ada_2005
13659 and then (Is_Abstract_Subprogram (Alias (New_Subp))
13660 or else (Is_Tagged_Type (Derived_Type)
13661 and then Etype (New_Subp) = Derived_Type
13662 and then No (Actual_Subp)))
13664 Set_Is_Abstract_Subprogram (New_Subp);
13666 -- AI05-0097 : an inherited operation that dispatches on result is
13667 -- abstract if the derived type is abstract, even if the parent type
13668 -- is concrete and the derived type is a null extension.
13670 elsif Has_Controlling_Result (Alias (New_Subp))
13671 and then Is_Abstract_Type (Etype (New_Subp))
13673 Set_Is_Abstract_Subprogram (New_Subp);
13675 -- Finally, if the parent type is abstract we must verify that all
13676 -- inherited operations are either non-abstract or overridden, or that
13677 -- the derived type itself is abstract (this check is performed at the
13678 -- end of a package declaration, in Check_Abstract_Overriding). A
13679 -- private overriding in the parent type will not be visible in the
13680 -- derivation if we are not in an inner package or in a child unit of
13681 -- the parent type, in which case the abstractness of the inherited
13682 -- operation is carried to the new subprogram.
13684 elsif Is_Abstract_Type (Parent_Type)
13685 and then not In_Open_Scopes (Scope (Parent_Type))
13686 and then Is_Private_Overriding
13687 and then Is_Abstract_Subprogram (Visible_Subp)
13689 if No (Actual_Subp) then
13690 Set_Alias (New_Subp, Visible_Subp);
13691 Set_Is_Abstract_Subprogram (New_Subp, True);
13694 -- If this is a derivation for an instance of a formal derived
13695 -- type, abstractness comes from the primitive operation of the
13696 -- actual, not from the operation inherited from the ancestor.
13698 Set_Is_Abstract_Subprogram
13699 (New_Subp, Is_Abstract_Subprogram (Actual_Subp));
13703 New_Overloaded_Entity (New_Subp, Derived_Type);
13705 -- Check for case of a derived subprogram for the instantiation of a
13706 -- formal derived tagged type, if so mark the subprogram as dispatching
13707 -- and inherit the dispatching attributes of the actual subprogram. The
13708 -- derived subprogram is effectively renaming of the actual subprogram,
13709 -- so it needs to have the same attributes as the actual.
13711 if Present (Actual_Subp)
13712 and then Is_Dispatching_Operation (Actual_Subp)
13714 Set_Is_Dispatching_Operation (New_Subp);
13716 if Present (DTC_Entity (Actual_Subp)) then
13717 Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp));
13718 Set_DT_Position (New_Subp, DT_Position (Actual_Subp));
13722 -- Indicate that a derived subprogram does not require a body and that
13723 -- it does not require processing of default expressions.
13725 Set_Has_Completion (New_Subp);
13726 Set_Default_Expressions_Processed (New_Subp);
13728 if Ekind (New_Subp) = E_Function then
13729 Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
13731 end Derive_Subprogram;
13733 ------------------------
13734 -- Derive_Subprograms --
13735 ------------------------
13737 procedure Derive_Subprograms
13738 (Parent_Type : Entity_Id;
13739 Derived_Type : Entity_Id;
13740 Generic_Actual : Entity_Id := Empty)
13742 Op_List : constant Elist_Id :=
13743 Collect_Primitive_Operations (Parent_Type);
13745 function Check_Derived_Type return Boolean;
13746 -- Check that all the entities derived from Parent_Type are found in
13747 -- the list of primitives of Derived_Type exactly in the same order.
13749 procedure Derive_Interface_Subprogram
13750 (New_Subp : in out Entity_Id;
13752 Actual_Subp : Entity_Id);
13753 -- Derive New_Subp from the ultimate alias of the parent subprogram Subp
13754 -- (which is an interface primitive). If Generic_Actual is present then
13755 -- Actual_Subp is the actual subprogram corresponding with the generic
13756 -- subprogram Subp.
13758 function Check_Derived_Type return Boolean is
13762 New_Subp : Entity_Id;
13767 -- Traverse list of entities in the current scope searching for
13768 -- an incomplete type whose full-view is derived type
13770 E := First_Entity (Scope (Derived_Type));
13771 while Present (E) and then E /= Derived_Type loop
13772 if Ekind (E) = E_Incomplete_Type
13773 and then Present (Full_View (E))
13774 and then Full_View (E) = Derived_Type
13776 -- Disable this test if Derived_Type completes an incomplete
13777 -- type because in such case more primitives can be added
13778 -- later to the list of primitives of Derived_Type by routine
13779 -- Process_Incomplete_Dependents
13784 E := Next_Entity (E);
13787 List := Collect_Primitive_Operations (Derived_Type);
13788 Elmt := First_Elmt (List);
13790 Op_Elmt := First_Elmt (Op_List);
13791 while Present (Op_Elmt) loop
13792 Subp := Node (Op_Elmt);
13793 New_Subp := Node (Elmt);
13795 -- At this early stage Derived_Type has no entities with attribute
13796 -- Interface_Alias. In addition, such primitives are always
13797 -- located at the end of the list of primitives of Parent_Type.
13798 -- Therefore, if found we can safely stop processing pending
13801 exit when Present (Interface_Alias (Subp));
13803 -- Handle hidden entities
13805 if not Is_Predefined_Dispatching_Operation (Subp)
13806 and then Is_Hidden (Subp)
13808 if Present (New_Subp)
13809 and then Primitive_Names_Match (Subp, New_Subp)
13815 if not Present (New_Subp)
13816 or else Ekind (Subp) /= Ekind (New_Subp)
13817 or else not Primitive_Names_Match (Subp, New_Subp)
13825 Next_Elmt (Op_Elmt);
13829 end Check_Derived_Type;
13831 ---------------------------------
13832 -- Derive_Interface_Subprogram --
13833 ---------------------------------
13835 procedure Derive_Interface_Subprogram
13836 (New_Subp : in out Entity_Id;
13838 Actual_Subp : Entity_Id)
13840 Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp);
13841 Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp);
13844 pragma Assert (Is_Interface (Iface_Type));
13847 (New_Subp => New_Subp,
13848 Parent_Subp => Iface_Subp,
13849 Derived_Type => Derived_Type,
13850 Parent_Type => Iface_Type,
13851 Actual_Subp => Actual_Subp);
13853 -- Given that this new interface entity corresponds with a primitive
13854 -- of the parent that was not overridden we must leave it associated
13855 -- with its parent primitive to ensure that it will share the same
13856 -- dispatch table slot when overridden.
13858 if No (Actual_Subp) then
13859 Set_Alias (New_Subp, Subp);
13861 -- For instantiations this is not needed since the previous call to
13862 -- Derive_Subprogram leaves the entity well decorated.
13865 pragma Assert (Alias (New_Subp) = Actual_Subp);
13868 end Derive_Interface_Subprogram;
13872 Alias_Subp : Entity_Id;
13873 Act_List : Elist_Id;
13874 Act_Elmt : Elmt_Id;
13875 Act_Subp : Entity_Id := Empty;
13877 Need_Search : Boolean := False;
13878 New_Subp : Entity_Id := Empty;
13879 Parent_Base : Entity_Id;
13882 -- Start of processing for Derive_Subprograms
13885 if Ekind (Parent_Type) = E_Record_Type_With_Private
13886 and then Has_Discriminants (Parent_Type)
13887 and then Present (Full_View (Parent_Type))
13889 Parent_Base := Full_View (Parent_Type);
13891 Parent_Base := Parent_Type;
13894 if Present (Generic_Actual) then
13895 Act_List := Collect_Primitive_Operations (Generic_Actual);
13896 Act_Elmt := First_Elmt (Act_List);
13898 Act_List := No_Elist;
13899 Act_Elmt := No_Elmt;
13902 -- Derive primitives inherited from the parent. Note that if the generic
13903 -- actual is present, this is not really a type derivation, it is a
13904 -- completion within an instance.
13906 -- Case 1: Derived_Type does not implement interfaces
13908 if not Is_Tagged_Type (Derived_Type)
13909 or else (not Has_Interfaces (Derived_Type)
13910 and then not (Present (Generic_Actual)
13911 and then Has_Interfaces (Generic_Actual)))
13913 Elmt := First_Elmt (Op_List);
13914 while Present (Elmt) loop
13915 Subp := Node (Elmt);
13917 -- Literals are derived earlier in the process of building the
13918 -- derived type, and are skipped here.
13920 if Ekind (Subp) = E_Enumeration_Literal then
13923 -- The actual is a direct descendant and the common primitive
13924 -- operations appear in the same order.
13926 -- If the generic parent type is present, the derived type is an
13927 -- instance of a formal derived type, and within the instance its
13928 -- operations are those of the actual. We derive from the formal
13929 -- type but make the inherited operations aliases of the
13930 -- corresponding operations of the actual.
13933 pragma Assert (No (Node (Act_Elmt))
13934 or else (Primitive_Names_Match (Subp, Node (Act_Elmt))
13937 (Subp, Node (Act_Elmt),
13938 Skip_Controlling_Formals => True)));
13941 (New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt));
13943 if Present (Act_Elmt) then
13944 Next_Elmt (Act_Elmt);
13951 -- Case 2: Derived_Type implements interfaces
13954 -- If the parent type has no predefined primitives we remove
13955 -- predefined primitives from the list of primitives of generic
13956 -- actual to simplify the complexity of this algorithm.
13958 if Present (Generic_Actual) then
13960 Has_Predefined_Primitives : Boolean := False;
13963 -- Check if the parent type has predefined primitives
13965 Elmt := First_Elmt (Op_List);
13966 while Present (Elmt) loop
13967 Subp := Node (Elmt);
13969 if Is_Predefined_Dispatching_Operation (Subp)
13970 and then not Comes_From_Source (Ultimate_Alias (Subp))
13972 Has_Predefined_Primitives := True;
13979 -- Remove predefined primitives of Generic_Actual. We must use
13980 -- an auxiliary list because in case of tagged types the value
13981 -- returned by Collect_Primitive_Operations is the value stored
13982 -- in its Primitive_Operations attribute (and we don't want to
13983 -- modify its current contents).
13985 if not Has_Predefined_Primitives then
13987 Aux_List : constant Elist_Id := New_Elmt_List;
13990 Elmt := First_Elmt (Act_List);
13991 while Present (Elmt) loop
13992 Subp := Node (Elmt);
13994 if not Is_Predefined_Dispatching_Operation (Subp)
13995 or else Comes_From_Source (Subp)
13997 Append_Elmt (Subp, Aux_List);
14003 Act_List := Aux_List;
14007 Act_Elmt := First_Elmt (Act_List);
14008 Act_Subp := Node (Act_Elmt);
14012 -- Stage 1: If the generic actual is not present we derive the
14013 -- primitives inherited from the parent type. If the generic parent
14014 -- type is present, the derived type is an instance of a formal
14015 -- derived type, and within the instance its operations are those of
14016 -- the actual. We derive from the formal type but make the inherited
14017 -- operations aliases of the corresponding operations of the actual.
14019 Elmt := First_Elmt (Op_List);
14020 while Present (Elmt) loop
14021 Subp := Node (Elmt);
14022 Alias_Subp := Ultimate_Alias (Subp);
14024 -- Do not derive internal entities of the parent that link
14025 -- interface primitives with their covering primitive. These
14026 -- entities will be added to this type when frozen.
14028 if Present (Interface_Alias (Subp)) then
14032 -- If the generic actual is present find the corresponding
14033 -- operation in the generic actual. If the parent type is a
14034 -- direct ancestor of the derived type then, even if it is an
14035 -- interface, the operations are inherited from the primary
14036 -- dispatch table and are in the proper order. If we detect here
14037 -- that primitives are not in the same order we traverse the list
14038 -- of primitive operations of the actual to find the one that
14039 -- implements the interface primitive.
14043 (Present (Generic_Actual)
14044 and then Present (Act_Subp)
14046 (Primitive_Names_Match (Subp, Act_Subp)
14048 Type_Conformant (Subp, Act_Subp,
14049 Skip_Controlling_Formals => True)))
14051 pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual,
14052 Use_Full_View => True));
14054 -- Remember that we need searching for all pending primitives
14056 Need_Search := True;
14058 -- Handle entities associated with interface primitives
14060 if Present (Alias_Subp)
14061 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
14062 and then not Is_Predefined_Dispatching_Operation (Subp)
14064 -- Search for the primitive in the homonym chain
14067 Find_Primitive_Covering_Interface
14068 (Tagged_Type => Generic_Actual,
14069 Iface_Prim => Alias_Subp);
14071 -- Previous search may not locate primitives covering
14072 -- interfaces defined in generics units or instantiations.
14073 -- (it fails if the covering primitive has formals whose
14074 -- type is also defined in generics or instantiations).
14075 -- In such case we search in the list of primitives of the
14076 -- generic actual for the internal entity that links the
14077 -- interface primitive and the covering primitive.
14080 and then Is_Generic_Type (Parent_Type)
14082 -- This code has been designed to handle only generic
14083 -- formals that implement interfaces that are defined
14084 -- in a generic unit or instantiation. If this code is
14085 -- needed for other cases we must review it because
14086 -- (given that it relies on Original_Location to locate
14087 -- the primitive of Generic_Actual that covers the
14088 -- interface) it could leave linked through attribute
14089 -- Alias entities of unrelated instantiations).
14093 (Scope (Find_Dispatching_Type (Alias_Subp)))
14095 Instantiation_Depth
14096 (Sloc (Find_Dispatching_Type (Alias_Subp))) > 0);
14099 Iface_Prim_Loc : constant Source_Ptr :=
14100 Original_Location (Sloc (Alias_Subp));
14107 First_Elmt (Primitive_Operations (Generic_Actual));
14109 Search : while Present (Elmt) loop
14110 Prim := Node (Elmt);
14112 if Present (Interface_Alias (Prim))
14113 and then Original_Location
14114 (Sloc (Interface_Alias (Prim))) =
14117 Act_Subp := Alias (Prim);
14126 pragma Assert (Present (Act_Subp)
14127 or else Is_Abstract_Type (Generic_Actual)
14128 or else Serious_Errors_Detected > 0);
14130 -- Handle predefined primitives plus the rest of user-defined
14134 Act_Elmt := First_Elmt (Act_List);
14135 while Present (Act_Elmt) loop
14136 Act_Subp := Node (Act_Elmt);
14138 exit when Primitive_Names_Match (Subp, Act_Subp)
14139 and then Type_Conformant
14141 Skip_Controlling_Formals => True)
14142 and then No (Interface_Alias (Act_Subp));
14144 Next_Elmt (Act_Elmt);
14147 if No (Act_Elmt) then
14153 -- Case 1: If the parent is a limited interface then it has the
14154 -- predefined primitives of synchronized interfaces. However, the
14155 -- actual type may be a non-limited type and hence it does not
14156 -- have such primitives.
14158 if Present (Generic_Actual)
14159 and then not Present (Act_Subp)
14160 and then Is_Limited_Interface (Parent_Base)
14161 and then Is_Predefined_Interface_Primitive (Subp)
14165 -- Case 2: Inherit entities associated with interfaces that were
14166 -- not covered by the parent type. We exclude here null interface
14167 -- primitives because they do not need special management.
14169 -- We also exclude interface operations that are renamings. If the
14170 -- subprogram is an explicit renaming of an interface primitive,
14171 -- it is a regular primitive operation, and the presence of its
14172 -- alias is not relevant: it has to be derived like any other
14175 elsif Present (Alias (Subp))
14176 and then Nkind (Unit_Declaration_Node (Subp)) /=
14177 N_Subprogram_Renaming_Declaration
14178 and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
14180 (Nkind (Parent (Alias_Subp)) = N_Procedure_Specification
14181 and then Null_Present (Parent (Alias_Subp)))
14183 -- If this is an abstract private type then we transfer the
14184 -- derivation of the interface primitive from the partial view
14185 -- to the full view. This is safe because all the interfaces
14186 -- must be visible in the partial view. Done to avoid adding
14187 -- a new interface derivation to the private part of the
14188 -- enclosing package; otherwise this new derivation would be
14189 -- decorated as hidden when the analysis of the enclosing
14190 -- package completes.
14192 if Is_Abstract_Type (Derived_Type)
14193 and then In_Private_Part (Current_Scope)
14194 and then Has_Private_Declaration (Derived_Type)
14197 Partial_View : Entity_Id;
14202 Partial_View := First_Entity (Current_Scope);
14204 exit when No (Partial_View)
14205 or else (Has_Private_Declaration (Partial_View)
14207 Full_View (Partial_View) = Derived_Type);
14209 Next_Entity (Partial_View);
14212 -- If the partial view was not found then the source code
14213 -- has errors and the derivation is not needed.
14215 if Present (Partial_View) then
14217 First_Elmt (Primitive_Operations (Partial_View));
14218 while Present (Elmt) loop
14219 Ent := Node (Elmt);
14221 if Present (Alias (Ent))
14222 and then Ultimate_Alias (Ent) = Alias (Subp)
14225 (Ent, Primitive_Operations (Derived_Type));
14232 -- If the interface primitive was not found in the
14233 -- partial view then this interface primitive was
14234 -- overridden. We add a derivation to activate in
14235 -- Derive_Progenitor_Subprograms the machinery to
14239 Derive_Interface_Subprogram
14240 (New_Subp => New_Subp,
14242 Actual_Subp => Act_Subp);
14247 Derive_Interface_Subprogram
14248 (New_Subp => New_Subp,
14250 Actual_Subp => Act_Subp);
14253 -- Case 3: Common derivation
14257 (New_Subp => New_Subp,
14258 Parent_Subp => Subp,
14259 Derived_Type => Derived_Type,
14260 Parent_Type => Parent_Base,
14261 Actual_Subp => Act_Subp);
14264 -- No need to update Act_Elm if we must search for the
14265 -- corresponding operation in the generic actual
14268 and then Present (Act_Elmt)
14270 Next_Elmt (Act_Elmt);
14271 Act_Subp := Node (Act_Elmt);
14278 -- Inherit additional operations from progenitors. If the derived
14279 -- type is a generic actual, there are not new primitive operations
14280 -- for the type because it has those of the actual, and therefore
14281 -- nothing needs to be done. The renamings generated above are not
14282 -- primitive operations, and their purpose is simply to make the
14283 -- proper operations visible within an instantiation.
14285 if No (Generic_Actual) then
14286 Derive_Progenitor_Subprograms (Parent_Base, Derived_Type);
14290 -- Final check: Direct descendants must have their primitives in the
14291 -- same order. We exclude from this test untagged types and instances
14292 -- of formal derived types. We skip this test if we have already
14293 -- reported serious errors in the sources.
14295 pragma Assert (not Is_Tagged_Type (Derived_Type)
14296 or else Present (Generic_Actual)
14297 or else Serious_Errors_Detected > 0
14298 or else Check_Derived_Type);
14299 end Derive_Subprograms;
14301 --------------------------------
14302 -- Derived_Standard_Character --
14303 --------------------------------
14305 procedure Derived_Standard_Character
14307 Parent_Type : Entity_Id;
14308 Derived_Type : Entity_Id)
14310 Loc : constant Source_Ptr := Sloc (N);
14311 Def : constant Node_Id := Type_Definition (N);
14312 Indic : constant Node_Id := Subtype_Indication (Def);
14313 Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
14314 Implicit_Base : constant Entity_Id :=
14316 (E_Enumeration_Type, N, Derived_Type, 'B');
14322 Discard_Node (Process_Subtype (Indic, N));
14324 Set_Etype (Implicit_Base, Parent_Base);
14325 Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
14326 Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
14328 Set_Is_Character_Type (Implicit_Base, True);
14329 Set_Has_Delayed_Freeze (Implicit_Base);
14331 -- The bounds of the implicit base are the bounds of the parent base.
14332 -- Note that their type is the parent base.
14334 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
14335 Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
14337 Set_Scalar_Range (Implicit_Base,
14340 High_Bound => Hi));
14342 Conditional_Delay (Derived_Type, Parent_Type);
14344 Set_Ekind (Derived_Type, E_Enumeration_Subtype);
14345 Set_Etype (Derived_Type, Implicit_Base);
14346 Set_Size_Info (Derived_Type, Parent_Type);
14348 if Unknown_RM_Size (Derived_Type) then
14349 Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
14352 Set_Is_Character_Type (Derived_Type, True);
14354 if Nkind (Indic) /= N_Subtype_Indication then
14356 -- If no explicit constraint, the bounds are those
14357 -- of the parent type.
14359 Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
14360 Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
14361 Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
14364 Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
14366 -- Because the implicit base is used in the conversion of the bounds, we
14367 -- have to freeze it now. This is similar to what is done for numeric
14368 -- types, and it equally suspicious, but otherwise a non-static bound
14369 -- will have a reference to an unfrozen type, which is rejected by Gigi
14370 -- (???). This requires specific care for definition of stream
14371 -- attributes. For details, see comments at the end of
14372 -- Build_Derived_Numeric_Type.
14374 Freeze_Before (N, Implicit_Base);
14375 end Derived_Standard_Character;
14377 ------------------------------
14378 -- Derived_Type_Declaration --
14379 ------------------------------
14381 procedure Derived_Type_Declaration
14384 Is_Completion : Boolean)
14386 Parent_Type : Entity_Id;
14388 function Comes_From_Generic (Typ : Entity_Id) return Boolean;
14389 -- Check whether the parent type is a generic formal, or derives
14390 -- directly or indirectly from one.
14392 ------------------------
14393 -- Comes_From_Generic --
14394 ------------------------
14396 function Comes_From_Generic (Typ : Entity_Id) return Boolean is
14398 if Is_Generic_Type (Typ) then
14401 elsif Is_Generic_Type (Root_Type (Parent_Type)) then
14404 elsif Is_Private_Type (Typ)
14405 and then Present (Full_View (Typ))
14406 and then Is_Generic_Type (Root_Type (Full_View (Typ)))
14410 elsif Is_Generic_Actual_Type (Typ) then
14416 end Comes_From_Generic;
14420 Def : constant Node_Id := Type_Definition (N);
14421 Iface_Def : Node_Id;
14422 Indic : constant Node_Id := Subtype_Indication (Def);
14423 Extension : constant Node_Id := Record_Extension_Part (Def);
14424 Parent_Node : Node_Id;
14427 -- Start of processing for Derived_Type_Declaration
14430 Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
14432 -- Ada 2005 (AI-251): In case of interface derivation check that the
14433 -- parent is also an interface.
14435 if Interface_Present (Def) then
14436 Check_SPARK_Restriction ("interface is not allowed", Def);
14438 if not Is_Interface (Parent_Type) then
14439 Diagnose_Interface (Indic, Parent_Type);
14442 Parent_Node := Parent (Base_Type (Parent_Type));
14443 Iface_Def := Type_Definition (Parent_Node);
14445 -- Ada 2005 (AI-251): Limited interfaces can only inherit from
14446 -- other limited interfaces.
14448 if Limited_Present (Def) then
14449 if Limited_Present (Iface_Def) then
14452 elsif Protected_Present (Iface_Def) then
14454 ("descendant of& must be declared"
14455 & " as a protected interface",
14458 elsif Synchronized_Present (Iface_Def) then
14460 ("descendant of& must be declared"
14461 & " as a synchronized interface",
14464 elsif Task_Present (Iface_Def) then
14466 ("descendant of& must be declared as a task interface",
14471 ("(Ada 2005) limited interface cannot "
14472 & "inherit from non-limited interface", Indic);
14475 -- Ada 2005 (AI-345): Non-limited interfaces can only inherit
14476 -- from non-limited or limited interfaces.
14478 elsif not Protected_Present (Def)
14479 and then not Synchronized_Present (Def)
14480 and then not Task_Present (Def)
14482 if Limited_Present (Iface_Def) then
14485 elsif Protected_Present (Iface_Def) then
14487 ("descendant of& must be declared"
14488 & " as a protected interface",
14491 elsif Synchronized_Present (Iface_Def) then
14493 ("descendant of& must be declared"
14494 & " as a synchronized interface",
14497 elsif Task_Present (Iface_Def) then
14499 ("descendant of& must be declared as a task interface",
14508 if Is_Tagged_Type (Parent_Type)
14509 and then Is_Concurrent_Type (Parent_Type)
14510 and then not Is_Interface (Parent_Type)
14513 ("parent type of a record extension cannot be "
14514 & "a synchronized tagged type (RM 3.9.1 (3/1))", N);
14515 Set_Etype (T, Any_Type);
14519 -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
14522 if Is_Tagged_Type (Parent_Type)
14523 and then Is_Non_Empty_List (Interface_List (Def))
14530 Intf := First (Interface_List (Def));
14531 while Present (Intf) loop
14532 T := Find_Type_Of_Subtype_Indic (Intf);
14534 if not Is_Interface (T) then
14535 Diagnose_Interface (Intf, T);
14537 -- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow
14538 -- a limited type from having a nonlimited progenitor.
14540 elsif (Limited_Present (Def)
14541 or else (not Is_Interface (Parent_Type)
14542 and then Is_Limited_Type (Parent_Type)))
14543 and then not Is_Limited_Interface (T)
14546 ("progenitor interface& of limited type must be limited",
14555 if Parent_Type = Any_Type
14556 or else Etype (Parent_Type) = Any_Type
14557 or else (Is_Class_Wide_Type (Parent_Type)
14558 and then Etype (Parent_Type) = T)
14560 -- If Parent_Type is undefined or illegal, make new type into a
14561 -- subtype of Any_Type, and set a few attributes to prevent cascaded
14562 -- errors. If this is a self-definition, emit error now.
14565 or else T = Etype (Parent_Type)
14567 Error_Msg_N ("type cannot be used in its own definition", Indic);
14570 Set_Ekind (T, Ekind (Parent_Type));
14571 Set_Etype (T, Any_Type);
14572 Set_Scalar_Range (T, Scalar_Range (Any_Type));
14574 if Is_Tagged_Type (T)
14575 and then Is_Record_Type (T)
14577 Set_Direct_Primitive_Operations (T, New_Elmt_List);
14583 -- Ada 2005 (AI-251): The case in which the parent of the full-view is
14584 -- an interface is special because the list of interfaces in the full
14585 -- view can be given in any order. For example:
14587 -- type A is interface;
14588 -- type B is interface and A;
14589 -- type D is new B with private;
14591 -- type D is new A and B with null record; -- 1 --
14593 -- In this case we perform the following transformation of -1-:
14595 -- type D is new B and A with null record;
14597 -- If the parent of the full-view covers the parent of the partial-view
14598 -- we have two possible cases:
14600 -- 1) They have the same parent
14601 -- 2) The parent of the full-view implements some further interfaces
14603 -- In both cases we do not need to perform the transformation. In the
14604 -- first case the source program is correct and the transformation is
14605 -- not needed; in the second case the source program does not fulfill
14606 -- the no-hidden interfaces rule (AI-396) and the error will be reported
14609 -- This transformation not only simplifies the rest of the analysis of
14610 -- this type declaration but also simplifies the correct generation of
14611 -- the object layout to the expander.
14613 if In_Private_Part (Current_Scope)
14614 and then Is_Interface (Parent_Type)
14618 Partial_View : Entity_Id;
14619 Partial_View_Parent : Entity_Id;
14620 New_Iface : Node_Id;
14623 -- Look for the associated private type declaration
14625 Partial_View := First_Entity (Current_Scope);
14627 exit when No (Partial_View)
14628 or else (Has_Private_Declaration (Partial_View)
14629 and then Full_View (Partial_View) = T);
14631 Next_Entity (Partial_View);
14634 -- If the partial view was not found then the source code has
14635 -- errors and the transformation is not needed.
14637 if Present (Partial_View) then
14638 Partial_View_Parent := Etype (Partial_View);
14640 -- If the parent of the full-view covers the parent of the
14641 -- partial-view we have nothing else to do.
14643 if Interface_Present_In_Ancestor
14644 (Parent_Type, Partial_View_Parent)
14648 -- Traverse the list of interfaces of the full-view to look
14649 -- for the parent of the partial-view and perform the tree
14653 Iface := First (Interface_List (Def));
14654 while Present (Iface) loop
14655 if Etype (Iface) = Etype (Partial_View) then
14656 Rewrite (Subtype_Indication (Def),
14657 New_Copy (Subtype_Indication
14658 (Parent (Partial_View))));
14661 Make_Identifier (Sloc (N), Chars (Parent_Type));
14662 Append (New_Iface, Interface_List (Def));
14664 -- Analyze the transformed code
14666 Derived_Type_Declaration (T, N, Is_Completion);
14677 -- Only composite types other than array types are allowed to have
14678 -- discriminants. In SPARK, no types are allowed to have discriminants.
14680 if Present (Discriminant_Specifications (N)) then
14681 if (Is_Elementary_Type (Parent_Type)
14682 or else Is_Array_Type (Parent_Type))
14683 and then not Error_Posted (N)
14686 ("elementary or array type cannot have discriminants",
14687 Defining_Identifier (First (Discriminant_Specifications (N))));
14688 Set_Has_Discriminants (T, False);
14690 Check_SPARK_Restriction ("discriminant type is not allowed", N);
14694 -- In Ada 83, a derived type defined in a package specification cannot
14695 -- be used for further derivation until the end of its visible part.
14696 -- Note that derivation in the private part of the package is allowed.
14698 if Ada_Version = Ada_83
14699 and then Is_Derived_Type (Parent_Type)
14700 and then In_Visible_Part (Scope (Parent_Type))
14702 if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
14704 ("(Ada 83): premature use of type for derivation", Indic);
14708 -- Check for early use of incomplete or private type
14710 if Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
14711 Error_Msg_N ("premature derivation of incomplete type", Indic);
14714 elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
14715 and then not Comes_From_Generic (Parent_Type))
14716 or else Has_Private_Component (Parent_Type)
14718 -- The ancestor type of a formal type can be incomplete, in which
14719 -- case only the operations of the partial view are available in the
14720 -- generic. Subsequent checks may be required when the full view is
14721 -- analyzed to verify that a derivation from a tagged type has an
14724 if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
14727 elsif No (Underlying_Type (Parent_Type))
14728 or else Has_Private_Component (Parent_Type)
14731 ("premature derivation of derived or private type", Indic);
14733 -- Flag the type itself as being in error, this prevents some
14734 -- nasty problems with subsequent uses of the malformed type.
14736 Set_Error_Posted (T);
14738 -- Check that within the immediate scope of an untagged partial
14739 -- view it's illegal to derive from the partial view if the
14740 -- full view is tagged. (7.3(7))
14742 -- We verify that the Parent_Type is a partial view by checking
14743 -- that it is not a Full_Type_Declaration (i.e. a private type or
14744 -- private extension declaration), to distinguish a partial view
14745 -- from a derivation from a private type which also appears as
14746 -- E_Private_Type. If the parent base type is not declared in an
14747 -- enclosing scope there is no need to check.
14749 elsif Present (Full_View (Parent_Type))
14750 and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
14751 and then not Is_Tagged_Type (Parent_Type)
14752 and then Is_Tagged_Type (Full_View (Parent_Type))
14753 and then In_Open_Scopes (Scope (Base_Type (Parent_Type)))
14756 ("premature derivation from type with tagged full view",
14761 -- Check that form of derivation is appropriate
14763 Taggd := Is_Tagged_Type (Parent_Type);
14765 -- Perhaps the parent type should be changed to the class-wide type's
14766 -- specific type in this case to prevent cascading errors ???
14768 if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
14769 Error_Msg_N ("parent type must not be a class-wide type", Indic);
14773 if Present (Extension) and then not Taggd then
14775 ("type derived from untagged type cannot have extension", Indic);
14777 elsif No (Extension) and then Taggd then
14779 -- If this declaration is within a private part (or body) of a
14780 -- generic instantiation then the derivation is allowed (the parent
14781 -- type can only appear tagged in this case if it's a generic actual
14782 -- type, since it would otherwise have been rejected in the analysis
14783 -- of the generic template).
14785 if not Is_Generic_Actual_Type (Parent_Type)
14786 or else In_Visible_Part (Scope (Parent_Type))
14788 if Is_Class_Wide_Type (Parent_Type) then
14790 ("parent type must not be a class-wide type", Indic);
14792 -- Use specific type to prevent cascaded errors.
14794 Parent_Type := Etype (Parent_Type);
14798 ("type derived from tagged type must have extension", Indic);
14803 -- AI-443: Synchronized formal derived types require a private
14804 -- extension. There is no point in checking the ancestor type or
14805 -- the progenitors since the construct is wrong to begin with.
14807 if Ada_Version >= Ada_2005
14808 and then Is_Generic_Type (T)
14809 and then Present (Original_Node (N))
14812 Decl : constant Node_Id := Original_Node (N);
14815 if Nkind (Decl) = N_Formal_Type_Declaration
14816 and then Nkind (Formal_Type_Definition (Decl)) =
14817 N_Formal_Derived_Type_Definition
14818 and then Synchronized_Present (Formal_Type_Definition (Decl))
14819 and then No (Extension)
14821 -- Avoid emitting a duplicate error message
14823 and then not Error_Posted (Indic)
14826 ("synchronized derived type must have extension", N);
14831 if Null_Exclusion_Present (Def)
14832 and then not Is_Access_Type (Parent_Type)
14834 Error_Msg_N ("null exclusion can only apply to an access type", N);
14837 -- Avoid deriving parent primitives of underlying record views
14839 Build_Derived_Type (N, Parent_Type, T, Is_Completion,
14840 Derive_Subps => not Is_Underlying_Record_View (T));
14842 -- AI-419: The parent type of an explicitly limited derived type must
14843 -- be a limited type or a limited interface.
14845 if Limited_Present (Def) then
14846 Set_Is_Limited_Record (T);
14848 if Is_Interface (T) then
14849 Set_Is_Limited_Interface (T);
14852 if not Is_Limited_Type (Parent_Type)
14854 (not Is_Interface (Parent_Type)
14855 or else not Is_Limited_Interface (Parent_Type))
14857 -- AI05-0096: a derivation in the private part of an instance is
14858 -- legal if the generic formal is untagged limited, and the actual
14861 if Is_Generic_Actual_Type (Parent_Type)
14862 and then In_Private_Part (Current_Scope)
14865 (Generic_Parent_Type (Parent (Parent_Type)))
14871 ("parent type& of limited type must be limited",
14877 -- In SPARK, there are no derived type definitions other than type
14878 -- extensions of tagged record types.
14880 if No (Extension) then
14881 Check_SPARK_Restriction
14882 ("derived type is not allowed", Original_Node (N));
14884 end Derived_Type_Declaration;
14886 ------------------------
14887 -- Diagnose_Interface --
14888 ------------------------
14890 procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is
14892 if not Is_Interface (E)
14893 and then E /= Any_Type
14895 Error_Msg_NE ("(Ada 2005) & must be an interface", N, E);
14897 end Diagnose_Interface;
14899 ----------------------------------
14900 -- Enumeration_Type_Declaration --
14901 ----------------------------------
14903 procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
14910 -- Create identifier node representing lower bound
14912 B_Node := New_Node (N_Identifier, Sloc (Def));
14913 L := First (Literals (Def));
14914 Set_Chars (B_Node, Chars (L));
14915 Set_Entity (B_Node, L);
14916 Set_Etype (B_Node, T);
14917 Set_Is_Static_Expression (B_Node, True);
14919 R_Node := New_Node (N_Range, Sloc (Def));
14920 Set_Low_Bound (R_Node, B_Node);
14922 Set_Ekind (T, E_Enumeration_Type);
14923 Set_First_Literal (T, L);
14925 Set_Is_Constrained (T);
14929 -- Loop through literals of enumeration type setting pos and rep values
14930 -- except that if the Ekind is already set, then it means the literal
14931 -- was already constructed (case of a derived type declaration and we
14932 -- should not disturb the Pos and Rep values.
14934 while Present (L) loop
14935 if Ekind (L) /= E_Enumeration_Literal then
14936 Set_Ekind (L, E_Enumeration_Literal);
14937 Set_Enumeration_Pos (L, Ev);
14938 Set_Enumeration_Rep (L, Ev);
14939 Set_Is_Known_Valid (L, True);
14943 New_Overloaded_Entity (L);
14944 Generate_Definition (L);
14945 Set_Convention (L, Convention_Intrinsic);
14947 -- Case of character literal
14949 if Nkind (L) = N_Defining_Character_Literal then
14950 Set_Is_Character_Type (T, True);
14952 -- Check violation of No_Wide_Characters
14954 if Restriction_Check_Required (No_Wide_Characters) then
14955 Get_Name_String (Chars (L));
14957 if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then
14958 Check_Restriction (No_Wide_Characters, L);
14967 -- Now create a node representing upper bound
14969 B_Node := New_Node (N_Identifier, Sloc (Def));
14970 Set_Chars (B_Node, Chars (Last (Literals (Def))));
14971 Set_Entity (B_Node, Last (Literals (Def)));
14972 Set_Etype (B_Node, T);
14973 Set_Is_Static_Expression (B_Node, True);
14975 Set_High_Bound (R_Node, B_Node);
14977 -- Initialize various fields of the type. Some of this information
14978 -- may be overwritten later through rep.clauses.
14980 Set_Scalar_Range (T, R_Node);
14981 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
14982 Set_Enum_Esize (T);
14983 Set_Enum_Pos_To_Rep (T, Empty);
14985 -- Set Discard_Names if configuration pragma set, or if there is
14986 -- a parameterless pragma in the current declarative region
14988 if Global_Discard_Names or else Discard_Names (Scope (T)) then
14989 Set_Discard_Names (T);
14992 -- Process end label if there is one
14994 if Present (Def) then
14995 Process_End_Label (Def, 'e', T);
14997 end Enumeration_Type_Declaration;
14999 ---------------------------------
15000 -- Expand_To_Stored_Constraint --
15001 ---------------------------------
15003 function Expand_To_Stored_Constraint
15005 Constraint : Elist_Id) return Elist_Id
15007 Explicitly_Discriminated_Type : Entity_Id;
15008 Expansion : Elist_Id;
15009 Discriminant : Entity_Id;
15011 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
15012 -- Find the nearest type that actually specifies discriminants
15014 ---------------------------------
15015 -- Type_With_Explicit_Discrims --
15016 ---------------------------------
15018 function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
15019 Typ : constant E := Base_Type (Id);
15022 if Ekind (Typ) in Incomplete_Or_Private_Kind then
15023 if Present (Full_View (Typ)) then
15024 return Type_With_Explicit_Discrims (Full_View (Typ));
15028 if Has_Discriminants (Typ) then
15033 if Etype (Typ) = Typ then
15035 elsif Has_Discriminants (Typ) then
15038 return Type_With_Explicit_Discrims (Etype (Typ));
15041 end Type_With_Explicit_Discrims;
15043 -- Start of processing for Expand_To_Stored_Constraint
15047 or else Is_Empty_Elmt_List (Constraint)
15052 Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
15054 if No (Explicitly_Discriminated_Type) then
15058 Expansion := New_Elmt_List;
15061 First_Stored_Discriminant (Explicitly_Discriminated_Type);
15062 while Present (Discriminant) loop
15064 Get_Discriminant_Value (
15065 Discriminant, Explicitly_Discriminated_Type, Constraint),
15067 Next_Stored_Discriminant (Discriminant);
15071 end Expand_To_Stored_Constraint;
15073 ---------------------------
15074 -- Find_Hidden_Interface --
15075 ---------------------------
15077 function Find_Hidden_Interface
15079 Dest : Elist_Id) return Entity_Id
15082 Iface_Elmt : Elmt_Id;
15085 if Present (Src) and then Present (Dest) then
15086 Iface_Elmt := First_Elmt (Src);
15087 while Present (Iface_Elmt) loop
15088 Iface := Node (Iface_Elmt);
15090 if Is_Interface (Iface)
15091 and then not Contain_Interface (Iface, Dest)
15096 Next_Elmt (Iface_Elmt);
15101 end Find_Hidden_Interface;
15103 --------------------
15104 -- Find_Type_Name --
15105 --------------------
15107 function Find_Type_Name (N : Node_Id) return Entity_Id is
15108 Id : constant Entity_Id := Defining_Identifier (N);
15110 New_Id : Entity_Id;
15111 Prev_Par : Node_Id;
15113 procedure Check_Duplicate_Aspects;
15114 -- Check that aspects specified in a completion have not been specified
15115 -- already in the partial view. Type_Invariant and others can be
15116 -- specified on either view but never on both.
15118 procedure Tag_Mismatch;
15119 -- Diagnose a tagged partial view whose full view is untagged.
15120 -- We post the message on the full view, with a reference to
15121 -- the previous partial view. The partial view can be private
15122 -- or incomplete, and these are handled in a different manner,
15123 -- so we determine the position of the error message from the
15124 -- respective slocs of both.
15126 -----------------------------
15127 -- Check_Duplicate_Aspects --
15128 -----------------------------
15129 procedure Check_Duplicate_Aspects is
15130 Prev_Aspects : constant List_Id := Aspect_Specifications (Prev_Par);
15131 Full_Aspects : constant List_Id := Aspect_Specifications (N);
15132 F_Spec, P_Spec : Node_Id;
15135 if Present (Prev_Aspects) and then Present (Full_Aspects) then
15136 F_Spec := First (Full_Aspects);
15137 while Present (F_Spec) loop
15138 P_Spec := First (Prev_Aspects);
15139 while Present (P_Spec) loop
15141 Chars (Identifier (P_Spec)) = Chars (Identifier (F_Spec))
15144 ("aspect already specified in private declaration",
15156 end Check_Duplicate_Aspects;
15162 procedure Tag_Mismatch is
15164 if Sloc (Prev) < Sloc (Id) then
15165 if Ada_Version >= Ada_2012
15166 and then Nkind (N) = N_Private_Type_Declaration
15169 ("declaration of private } must be a tagged type ", Id, Prev);
15172 ("full declaration of } must be a tagged type ", Id, Prev);
15175 if Ada_Version >= Ada_2012
15176 and then Nkind (N) = N_Private_Type_Declaration
15179 ("declaration of private } must be a tagged type ", Prev, Id);
15182 ("full declaration of } must be a tagged type ", Prev, Id);
15187 -- Start of processing for Find_Type_Name
15190 -- Find incomplete declaration, if one was given
15192 Prev := Current_Entity_In_Scope (Id);
15194 -- New type declaration
15200 -- Previous declaration exists
15203 Prev_Par := Parent (Prev);
15205 -- Error if not incomplete/private case except if previous
15206 -- declaration is implicit, etc. Enter_Name will emit error if
15209 if not Is_Incomplete_Or_Private_Type (Prev) then
15213 -- Check invalid completion of private or incomplete type
15215 elsif not Nkind_In (N, N_Full_Type_Declaration,
15216 N_Task_Type_Declaration,
15217 N_Protected_Type_Declaration)
15219 (Ada_Version < Ada_2012
15220 or else not Is_Incomplete_Type (Prev)
15221 or else not Nkind_In (N, N_Private_Type_Declaration,
15222 N_Private_Extension_Declaration))
15224 -- Completion must be a full type declarations (RM 7.3(4))
15226 Error_Msg_Sloc := Sloc (Prev);
15227 Error_Msg_NE ("invalid completion of }", Id, Prev);
15229 -- Set scope of Id to avoid cascaded errors. Entity is never
15230 -- examined again, except when saving globals in generics.
15232 Set_Scope (Id, Current_Scope);
15235 -- If this is a repeated incomplete declaration, no further
15236 -- checks are possible.
15238 if Nkind (N) = N_Incomplete_Type_Declaration then
15242 -- Case of full declaration of incomplete type
15244 elsif Ekind (Prev) = E_Incomplete_Type
15245 and then (Ada_Version < Ada_2012
15246 or else No (Full_View (Prev))
15247 or else not Is_Private_Type (Full_View (Prev)))
15250 -- Indicate that the incomplete declaration has a matching full
15251 -- declaration. The defining occurrence of the incomplete
15252 -- declaration remains the visible one, and the procedure
15253 -- Get_Full_View dereferences it whenever the type is used.
15255 if Present (Full_View (Prev)) then
15256 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
15259 Set_Full_View (Prev, Id);
15260 Append_Entity (Id, Current_Scope);
15261 Set_Is_Public (Id, Is_Public (Prev));
15262 Set_Is_Internal (Id);
15265 -- If the incomplete view is tagged, a class_wide type has been
15266 -- created already. Use it for the private type as well, in order
15267 -- to prevent multiple incompatible class-wide types that may be
15268 -- created for self-referential anonymous access components.
15270 if Is_Tagged_Type (Prev)
15271 and then Present (Class_Wide_Type (Prev))
15273 Set_Ekind (Id, Ekind (Prev)); -- will be reset later
15274 Set_Class_Wide_Type (Id, Class_Wide_Type (Prev));
15276 -- If the incomplete type is completed by a private declaration
15277 -- the class-wide type remains associated with the incomplete
15278 -- type, to prevent order-of-elaboration issues in gigi, else
15279 -- we associate the class-wide type with the known full view.
15281 if Nkind (N) /= N_Private_Type_Declaration then
15282 Set_Etype (Class_Wide_Type (Id), Id);
15286 -- Case of full declaration of private type
15289 -- If the private type was a completion of an incomplete type then
15290 -- update Prev to reference the private type
15292 if Ada_Version >= Ada_2012
15293 and then Ekind (Prev) = E_Incomplete_Type
15294 and then Present (Full_View (Prev))
15295 and then Is_Private_Type (Full_View (Prev))
15297 Prev := Full_View (Prev);
15298 Prev_Par := Parent (Prev);
15301 if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
15302 if Etype (Prev) /= Prev then
15304 -- Prev is a private subtype or a derived type, and needs
15307 Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
15310 elsif Ekind (Prev) = E_Private_Type
15311 and then Nkind_In (N, N_Task_Type_Declaration,
15312 N_Protected_Type_Declaration)
15315 ("completion of nonlimited type cannot be limited", N);
15317 elsif Ekind (Prev) = E_Record_Type_With_Private
15318 and then Nkind_In (N, N_Task_Type_Declaration,
15319 N_Protected_Type_Declaration)
15321 if not Is_Limited_Record (Prev) then
15323 ("completion of nonlimited type cannot be limited", N);
15325 elsif No (Interface_List (N)) then
15327 ("completion of tagged private type must be tagged",
15331 elsif Nkind (N) = N_Full_Type_Declaration
15333 Nkind (Type_Definition (N)) = N_Record_Definition
15334 and then Interface_Present (Type_Definition (N))
15337 ("completion of private type cannot be an interface", N);
15340 -- Ada 2005 (AI-251): Private extension declaration of a task
15341 -- type or a protected type. This case arises when covering
15342 -- interface types.
15344 elsif Nkind_In (N, N_Task_Type_Declaration,
15345 N_Protected_Type_Declaration)
15349 elsif Nkind (N) /= N_Full_Type_Declaration
15350 or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
15353 ("full view of private extension must be an extension", N);
15355 elsif not (Abstract_Present (Parent (Prev)))
15356 and then Abstract_Present (Type_Definition (N))
15359 ("full view of non-abstract extension cannot be abstract", N);
15362 if not In_Private_Part (Current_Scope) then
15364 ("declaration of full view must appear in private part", N);
15367 if Ada_Version >= Ada_2012 then
15368 Check_Duplicate_Aspects;
15371 Copy_And_Swap (Prev, Id);
15372 Set_Has_Private_Declaration (Prev);
15373 Set_Has_Private_Declaration (Id);
15375 -- Preserve aspect and iterator flags that may have been set on
15376 -- the partial view.
15378 Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id));
15379 Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (Id));
15381 -- If no error, propagate freeze_node from private to full view.
15382 -- It may have been generated for an early operational item.
15384 if Present (Freeze_Node (Id))
15385 and then Serious_Errors_Detected = 0
15386 and then No (Full_View (Id))
15388 Set_Freeze_Node (Prev, Freeze_Node (Id));
15389 Set_Freeze_Node (Id, Empty);
15390 Set_First_Rep_Item (Prev, First_Rep_Item (Id));
15393 Set_Full_View (Id, Prev);
15397 -- Verify that full declaration conforms to partial one
15399 if Is_Incomplete_Or_Private_Type (Prev)
15400 and then Present (Discriminant_Specifications (Prev_Par))
15402 if Present (Discriminant_Specifications (N)) then
15403 if Ekind (Prev) = E_Incomplete_Type then
15404 Check_Discriminant_Conformance (N, Prev, Prev);
15406 Check_Discriminant_Conformance (N, Prev, Id);
15411 ("missing discriminants in full type declaration", N);
15413 -- To avoid cascaded errors on subsequent use, share the
15414 -- discriminants of the partial view.
15416 Set_Discriminant_Specifications (N,
15417 Discriminant_Specifications (Prev_Par));
15421 -- A prior untagged partial view can have an associated class-wide
15422 -- type due to use of the class attribute, and in this case the full
15423 -- type must also be tagged. This Ada 95 usage is deprecated in favor
15424 -- of incomplete tagged declarations, but we check for it.
15427 and then (Is_Tagged_Type (Prev)
15428 or else Present (Class_Wide_Type (Prev)))
15430 -- Ada 2012 (AI05-0162): A private type may be the completion of
15431 -- an incomplete type
15433 if Ada_Version >= Ada_2012
15434 and then Is_Incomplete_Type (Prev)
15435 and then Nkind_In (N, N_Private_Type_Declaration,
15436 N_Private_Extension_Declaration)
15438 -- No need to check private extensions since they are tagged
15440 if Nkind (N) = N_Private_Type_Declaration
15441 and then not Tagged_Present (N)
15446 -- The full declaration is either a tagged type (including
15447 -- a synchronized type that implements interfaces) or a
15448 -- type extension, otherwise this is an error.
15450 elsif Nkind_In (N, N_Task_Type_Declaration,
15451 N_Protected_Type_Declaration)
15453 if No (Interface_List (N))
15454 and then not Error_Posted (N)
15459 elsif Nkind (Type_Definition (N)) = N_Record_Definition then
15461 -- Indicate that the previous declaration (tagged incomplete
15462 -- or private declaration) requires the same on the full one.
15464 if not Tagged_Present (Type_Definition (N)) then
15466 Set_Is_Tagged_Type (Id);
15469 elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
15470 if No (Record_Extension_Part (Type_Definition (N))) then
15472 ("full declaration of } must be a record extension",
15475 -- Set some attributes to produce a usable full view
15477 Set_Is_Tagged_Type (Id);
15486 and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration
15487 and then Present (Premature_Use (Parent (Prev)))
15489 Error_Msg_Sloc := Sloc (N);
15491 ("\full declaration #", Premature_Use (Parent (Prev)));
15496 end Find_Type_Name;
15498 -------------------------
15499 -- Find_Type_Of_Object --
15500 -------------------------
15502 function Find_Type_Of_Object
15503 (Obj_Def : Node_Id;
15504 Related_Nod : Node_Id) return Entity_Id
15506 Def_Kind : constant Node_Kind := Nkind (Obj_Def);
15507 P : Node_Id := Parent (Obj_Def);
15512 -- If the parent is a component_definition node we climb to the
15513 -- component_declaration node
15515 if Nkind (P) = N_Component_Definition then
15519 -- Case of an anonymous array subtype
15521 if Nkind_In (Def_Kind, N_Constrained_Array_Definition,
15522 N_Unconstrained_Array_Definition)
15525 Array_Type_Declaration (T, Obj_Def);
15527 -- Create an explicit subtype whenever possible
15529 elsif Nkind (P) /= N_Component_Declaration
15530 and then Def_Kind = N_Subtype_Indication
15532 -- Base name of subtype on object name, which will be unique in
15533 -- the current scope.
15535 -- If this is a duplicate declaration, return base type, to avoid
15536 -- generating duplicate anonymous types.
15538 if Error_Posted (P) then
15539 Analyze (Subtype_Mark (Obj_Def));
15540 return Entity (Subtype_Mark (Obj_Def));
15545 (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
15547 T := Make_Defining_Identifier (Sloc (P), Nam);
15549 Insert_Action (Obj_Def,
15550 Make_Subtype_Declaration (Sloc (P),
15551 Defining_Identifier => T,
15552 Subtype_Indication => Relocate_Node (Obj_Def)));
15554 -- This subtype may need freezing, and this will not be done
15555 -- automatically if the object declaration is not in declarative
15556 -- part. Since this is an object declaration, the type cannot always
15557 -- be frozen here. Deferred constants do not freeze their type
15558 -- (which often enough will be private).
15560 if Nkind (P) = N_Object_Declaration
15561 and then Constant_Present (P)
15562 and then No (Expression (P))
15566 Insert_Actions (Obj_Def, Freeze_Entity (T, P));
15569 -- Ada 2005 AI-406: the object definition in an object declaration
15570 -- can be an access definition.
15572 elsif Def_Kind = N_Access_Definition then
15573 T := Access_Definition (Related_Nod, Obj_Def);
15575 Set_Is_Local_Anonymous_Access
15577 V => (Ada_Version < Ada_2012)
15578 or else (Nkind (P) /= N_Object_Declaration)
15579 or else Is_Library_Level_Entity (Defining_Identifier (P)));
15581 -- Otherwise, the object definition is just a subtype_mark
15584 T := Process_Subtype (Obj_Def, Related_Nod);
15586 -- If expansion is disabled an object definition that is an aggregate
15587 -- will not get expanded and may lead to scoping problems in the back
15588 -- end, if the object is referenced in an inner scope. In that case
15589 -- create an itype reference for the object definition now. This
15590 -- may be redundant in some cases, but harmless.
15593 and then Nkind (Related_Nod) = N_Object_Declaration
15596 Build_Itype_Reference (T, Related_Nod);
15601 end Find_Type_Of_Object;
15603 --------------------------------
15604 -- Find_Type_Of_Subtype_Indic --
15605 --------------------------------
15607 function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
15611 -- Case of subtype mark with a constraint
15613 if Nkind (S) = N_Subtype_Indication then
15614 Find_Type (Subtype_Mark (S));
15615 Typ := Entity (Subtype_Mark (S));
15618 Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
15621 ("incorrect constraint for this kind of type", Constraint (S));
15622 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
15625 -- Otherwise we have a subtype mark without a constraint
15627 elsif Error_Posted (S) then
15628 Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
15636 -- Check No_Wide_Characters restriction
15638 Check_Wide_Character_Restriction (Typ, S);
15641 end Find_Type_Of_Subtype_Indic;
15643 -------------------------------------
15644 -- Floating_Point_Type_Declaration --
15645 -------------------------------------
15647 procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
15648 Digs : constant Node_Id := Digits_Expression (Def);
15649 Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float);
15651 Base_Typ : Entity_Id;
15652 Implicit_Base : Entity_Id;
15655 function Can_Derive_From (E : Entity_Id) return Boolean;
15656 -- Find if given digits value, and possibly a specified range, allows
15657 -- derivation from specified type
15659 function Find_Base_Type return Entity_Id;
15660 -- Find a predefined base type that Def can derive from, or generate
15661 -- an error and substitute Long_Long_Float if none exists.
15663 ---------------------
15664 -- Can_Derive_From --
15665 ---------------------
15667 function Can_Derive_From (E : Entity_Id) return Boolean is
15668 Spec : constant Entity_Id := Real_Range_Specification (Def);
15671 -- Check specified "digits" constraint
15673 if Digs_Val > Digits_Value (E) then
15677 -- Avoid types not matching pragma Float_Representation, if present
15679 if (Opt.Float_Format = 'I' and then Float_Rep (E) /= IEEE_Binary)
15681 (Opt.Float_Format = 'V' and then Float_Rep (E) /= VAX_Native)
15686 -- Check for matching range, if specified
15688 if Present (Spec) then
15689 if Expr_Value_R (Type_Low_Bound (E)) >
15690 Expr_Value_R (Low_Bound (Spec))
15695 if Expr_Value_R (Type_High_Bound (E)) <
15696 Expr_Value_R (High_Bound (Spec))
15703 end Can_Derive_From;
15705 --------------------
15706 -- Find_Base_Type --
15707 --------------------
15709 function Find_Base_Type return Entity_Id is
15710 Choice : Elmt_Id := First_Elmt (Predefined_Float_Types);
15713 -- Iterate over the predefined types in order, returning the first
15714 -- one that Def can derive from.
15716 while Present (Choice) loop
15717 if Can_Derive_From (Node (Choice)) then
15718 return Node (Choice);
15721 Next_Elmt (Choice);
15724 -- If we can't derive from any existing type, use Long_Long_Float
15725 -- and give appropriate message explaining the problem.
15727 if Digs_Val > Max_Digs_Val then
15728 -- It might be the case that there is a type with the requested
15729 -- range, just not the combination of digits and range.
15732 ("no predefined type has requested range and precision",
15733 Real_Range_Specification (Def));
15737 ("range too large for any predefined type",
15738 Real_Range_Specification (Def));
15741 return Standard_Long_Long_Float;
15742 end Find_Base_Type;
15744 -- Start of processing for Floating_Point_Type_Declaration
15747 Check_Restriction (No_Floating_Point, Def);
15749 -- Create an implicit base type
15752 Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
15754 -- Analyze and verify digits value
15756 Analyze_And_Resolve (Digs, Any_Integer);
15757 Check_Digits_Expression (Digs);
15758 Digs_Val := Expr_Value (Digs);
15760 -- Process possible range spec and find correct type to derive from
15762 Process_Real_Range_Specification (Def);
15764 -- Check that requested number of digits is not too high.
15766 if Digs_Val > Max_Digs_Val then
15767 -- The check for Max_Base_Digits may be somewhat expensive, as it
15768 -- requires reading System, so only do it when necessary.
15771 Max_Base_Digits : constant Uint :=
15774 (Parent (RTE (RE_Max_Base_Digits))));
15777 if Digs_Val > Max_Base_Digits then
15778 Error_Msg_Uint_1 := Max_Base_Digits;
15779 Error_Msg_N ("digits value out of range, maximum is ^", Digs);
15781 elsif No (Real_Range_Specification (Def)) then
15782 Error_Msg_Uint_1 := Max_Digs_Val;
15783 Error_Msg_N ("types with more than ^ digits need range spec "
15784 & "(RM 3.5.7(6))", Digs);
15789 -- Find a suitable type to derive from or complain and use a substitute
15791 Base_Typ := Find_Base_Type;
15793 -- If there are bounds given in the declaration use them as the bounds
15794 -- of the type, otherwise use the bounds of the predefined base type
15795 -- that was chosen based on the Digits value.
15797 if Present (Real_Range_Specification (Def)) then
15798 Set_Scalar_Range (T, Real_Range_Specification (Def));
15799 Set_Is_Constrained (T);
15801 -- The bounds of this range must be converted to machine numbers
15802 -- in accordance with RM 4.9(38).
15804 Bound := Type_Low_Bound (T);
15806 if Nkind (Bound) = N_Real_Literal then
15808 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
15809 Set_Is_Machine_Number (Bound);
15812 Bound := Type_High_Bound (T);
15814 if Nkind (Bound) = N_Real_Literal then
15816 (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
15817 Set_Is_Machine_Number (Bound);
15821 Set_Scalar_Range (T, Scalar_Range (Base_Typ));
15824 -- Complete definition of implicit base and declared first subtype
15826 Set_Etype (Implicit_Base, Base_Typ);
15828 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
15829 Set_Size_Info (Implicit_Base, (Base_Typ));
15830 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
15831 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
15832 Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
15833 Set_Float_Rep (Implicit_Base, Float_Rep (Base_Typ));
15835 Set_Ekind (T, E_Floating_Point_Subtype);
15836 Set_Etype (T, Implicit_Base);
15838 Set_Size_Info (T, (Implicit_Base));
15839 Set_RM_Size (T, RM_Size (Implicit_Base));
15840 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
15841 Set_Digits_Value (T, Digs_Val);
15842 end Floating_Point_Type_Declaration;
15844 ----------------------------
15845 -- Get_Discriminant_Value --
15846 ----------------------------
15848 -- This is the situation:
15850 -- There is a non-derived type
15852 -- type T0 (Dx, Dy, Dz...)
15854 -- There are zero or more levels of derivation, with each derivation
15855 -- either purely inheriting the discriminants, or defining its own.
15857 -- type Ti is new Ti-1
15859 -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
15861 -- subtype Ti is ...
15863 -- The subtype issue is avoided by the use of Original_Record_Component,
15864 -- and the fact that derived subtypes also derive the constraints.
15866 -- This chain leads back from
15868 -- Typ_For_Constraint
15870 -- Typ_For_Constraint has discriminants, and the value for each
15871 -- discriminant is given by its corresponding Elmt of Constraints.
15873 -- Discriminant is some discriminant in this hierarchy
15875 -- We need to return its value
15877 -- We do this by recursively searching each level, and looking for
15878 -- Discriminant. Once we get to the bottom, we start backing up
15879 -- returning the value for it which may in turn be a discriminant
15880 -- further up, so on the backup we continue the substitution.
15882 function Get_Discriminant_Value
15883 (Discriminant : Entity_Id;
15884 Typ_For_Constraint : Entity_Id;
15885 Constraint : Elist_Id) return Node_Id
15887 function Root_Corresponding_Discriminant
15888 (Discr : Entity_Id) return Entity_Id;
15889 -- Given a discriminant, traverse the chain of inherited discriminants
15890 -- and return the topmost discriminant.
15892 function Search_Derivation_Levels
15894 Discrim_Values : Elist_Id;
15895 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
15896 -- This is the routine that performs the recursive search of levels
15897 -- as described above.
15899 -------------------------------------
15900 -- Root_Corresponding_Discriminant --
15901 -------------------------------------
15903 function Root_Corresponding_Discriminant
15904 (Discr : Entity_Id) return Entity_Id
15910 while Present (Corresponding_Discriminant (D)) loop
15911 D := Corresponding_Discriminant (D);
15915 end Root_Corresponding_Discriminant;
15917 ------------------------------
15918 -- Search_Derivation_Levels --
15919 ------------------------------
15921 function Search_Derivation_Levels
15923 Discrim_Values : Elist_Id;
15924 Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
15928 Result : Node_Or_Entity_Id;
15929 Result_Entity : Node_Id;
15932 -- If inappropriate type, return Error, this happens only in
15933 -- cascaded error situations, and we want to avoid a blow up.
15935 if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
15939 -- Look deeper if possible. Use Stored_Constraints only for
15940 -- untagged types. For tagged types use the given constraint.
15941 -- This asymmetry needs explanation???
15943 if not Stored_Discrim_Values
15944 and then Present (Stored_Constraint (Ti))
15945 and then not Is_Tagged_Type (Ti)
15948 Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
15951 Td : constant Entity_Id := Etype (Ti);
15955 Result := Discriminant;
15958 if Present (Stored_Constraint (Ti)) then
15960 Search_Derivation_Levels
15961 (Td, Stored_Constraint (Ti), True);
15964 Search_Derivation_Levels
15965 (Td, Discrim_Values, Stored_Discrim_Values);
15971 -- Extra underlying places to search, if not found above. For
15972 -- concurrent types, the relevant discriminant appears in the
15973 -- corresponding record. For a type derived from a private type
15974 -- without discriminant, the full view inherits the discriminants
15975 -- of the full view of the parent.
15977 if Result = Discriminant then
15978 if Is_Concurrent_Type (Ti)
15979 and then Present (Corresponding_Record_Type (Ti))
15982 Search_Derivation_Levels (
15983 Corresponding_Record_Type (Ti),
15985 Stored_Discrim_Values);
15987 elsif Is_Private_Type (Ti)
15988 and then not Has_Discriminants (Ti)
15989 and then Present (Full_View (Ti))
15990 and then Etype (Full_View (Ti)) /= Ti
15993 Search_Derivation_Levels (
15996 Stored_Discrim_Values);
16000 -- If Result is not a (reference to a) discriminant, return it,
16001 -- otherwise set Result_Entity to the discriminant.
16003 if Nkind (Result) = N_Defining_Identifier then
16004 pragma Assert (Result = Discriminant);
16005 Result_Entity := Result;
16008 if not Denotes_Discriminant (Result) then
16012 Result_Entity := Entity (Result);
16015 -- See if this level of derivation actually has discriminants
16016 -- because tagged derivations can add them, hence the lower
16017 -- levels need not have any.
16019 if not Has_Discriminants (Ti) then
16023 -- Scan Ti's discriminants for Result_Entity,
16024 -- and return its corresponding value, if any.
16026 Result_Entity := Original_Record_Component (Result_Entity);
16028 Assoc := First_Elmt (Discrim_Values);
16030 if Stored_Discrim_Values then
16031 Disc := First_Stored_Discriminant (Ti);
16033 Disc := First_Discriminant (Ti);
16036 while Present (Disc) loop
16037 pragma Assert (Present (Assoc));
16039 if Original_Record_Component (Disc) = Result_Entity then
16040 return Node (Assoc);
16045 if Stored_Discrim_Values then
16046 Next_Stored_Discriminant (Disc);
16048 Next_Discriminant (Disc);
16052 -- Could not find it
16055 end Search_Derivation_Levels;
16059 Result : Node_Or_Entity_Id;
16061 -- Start of processing for Get_Discriminant_Value
16064 -- ??? This routine is a gigantic mess and will be deleted. For the
16065 -- time being just test for the trivial case before calling recurse.
16067 if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
16073 D := First_Discriminant (Typ_For_Constraint);
16074 E := First_Elmt (Constraint);
16075 while Present (D) loop
16076 if Chars (D) = Chars (Discriminant) then
16080 Next_Discriminant (D);
16086 Result := Search_Derivation_Levels
16087 (Typ_For_Constraint, Constraint, False);
16089 -- ??? hack to disappear when this routine is gone
16091 if Nkind (Result) = N_Defining_Identifier then
16097 D := First_Discriminant (Typ_For_Constraint);
16098 E := First_Elmt (Constraint);
16099 while Present (D) loop
16100 if Root_Corresponding_Discriminant (D) = Discriminant then
16104 Next_Discriminant (D);
16110 pragma Assert (Nkind (Result) /= N_Defining_Identifier);
16112 end Get_Discriminant_Value;
16114 --------------------------
16115 -- Has_Range_Constraint --
16116 --------------------------
16118 function Has_Range_Constraint (N : Node_Id) return Boolean is
16119 C : constant Node_Id := Constraint (N);
16122 if Nkind (C) = N_Range_Constraint then
16125 elsif Nkind (C) = N_Digits_Constraint then
16127 Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
16129 Present (Range_Constraint (C));
16131 elsif Nkind (C) = N_Delta_Constraint then
16132 return Present (Range_Constraint (C));
16137 end Has_Range_Constraint;
16139 ------------------------
16140 -- Inherit_Components --
16141 ------------------------
16143 function Inherit_Components
16145 Parent_Base : Entity_Id;
16146 Derived_Base : Entity_Id;
16147 Is_Tagged : Boolean;
16148 Inherit_Discr : Boolean;
16149 Discs : Elist_Id) return Elist_Id
16151 Assoc_List : constant Elist_Id := New_Elmt_List;
16153 procedure Inherit_Component
16154 (Old_C : Entity_Id;
16155 Plain_Discrim : Boolean := False;
16156 Stored_Discrim : Boolean := False);
16157 -- Inherits component Old_C from Parent_Base to the Derived_Base. If
16158 -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
16159 -- True, Old_C is a stored discriminant. If they are both false then
16160 -- Old_C is a regular component.
16162 -----------------------
16163 -- Inherit_Component --
16164 -----------------------
16166 procedure Inherit_Component
16167 (Old_C : Entity_Id;
16168 Plain_Discrim : Boolean := False;
16169 Stored_Discrim : Boolean := False)
16171 procedure Set_Anonymous_Type (Id : Entity_Id);
16172 -- Id denotes the entity of an access discriminant or anonymous
16173 -- access component. Set the type of Id to either the same type of
16174 -- Old_C or create a new one depending on whether the parent and
16175 -- the child types are in the same scope.
16177 ------------------------
16178 -- Set_Anonymous_Type --
16179 ------------------------
16181 procedure Set_Anonymous_Type (Id : Entity_Id) is
16182 Old_Typ : constant Entity_Id := Etype (Old_C);
16185 if Scope (Parent_Base) = Scope (Derived_Base) then
16186 Set_Etype (Id, Old_Typ);
16188 -- The parent and the derived type are in two different scopes.
16189 -- Reuse the type of the original discriminant / component by
16190 -- copying it in order to preserve all attributes.
16194 Typ : constant Entity_Id := New_Copy (Old_Typ);
16197 Set_Etype (Id, Typ);
16199 -- Since we do not generate component declarations for
16200 -- inherited components, associate the itype with the
16203 Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base));
16204 Set_Scope (Typ, Derived_Base);
16207 end Set_Anonymous_Type;
16209 -- Local variables and constants
16211 New_C : constant Entity_Id := New_Copy (Old_C);
16213 Corr_Discrim : Entity_Id;
16214 Discrim : Entity_Id;
16216 -- Start of processing for Inherit_Component
16219 pragma Assert (not Is_Tagged or else not Stored_Discrim);
16221 Set_Parent (New_C, Parent (Old_C));
16223 -- Regular discriminants and components must be inserted in the scope
16224 -- of the Derived_Base. Do it here.
16226 if not Stored_Discrim then
16227 Enter_Name (New_C);
16230 -- For tagged types the Original_Record_Component must point to
16231 -- whatever this field was pointing to in the parent type. This has
16232 -- already been achieved by the call to New_Copy above.
16234 if not Is_Tagged then
16235 Set_Original_Record_Component (New_C, New_C);
16238 -- Set the proper type of an access discriminant
16240 if Ekind (New_C) = E_Discriminant
16241 and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type
16243 Set_Anonymous_Type (New_C);
16246 -- If we have inherited a component then see if its Etype contains
16247 -- references to Parent_Base discriminants. In this case, replace
16248 -- these references with the constraints given in Discs. We do not
16249 -- do this for the partial view of private types because this is
16250 -- not needed (only the components of the full view will be used
16251 -- for code generation) and cause problem. We also avoid this
16252 -- transformation in some error situations.
16254 if Ekind (New_C) = E_Component then
16256 -- Set the proper type of an anonymous access component
16258 if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then
16259 Set_Anonymous_Type (New_C);
16261 elsif (Is_Private_Type (Derived_Base)
16262 and then not Is_Generic_Type (Derived_Base))
16263 or else (Is_Empty_Elmt_List (Discs)
16264 and then not Expander_Active)
16266 Set_Etype (New_C, Etype (Old_C));
16269 -- The current component introduces a circularity of the
16272 -- limited with Pack_2;
16273 -- package Pack_1 is
16274 -- type T_1 is tagged record
16275 -- Comp : access Pack_2.T_2;
16281 -- package Pack_2 is
16282 -- type T_2 is new Pack_1.T_1 with ...;
16287 Constrain_Component_Type
16288 (Old_C, Derived_Base, N, Parent_Base, Discs));
16292 -- In derived tagged types it is illegal to reference a non
16293 -- discriminant component in the parent type. To catch this, mark
16294 -- these components with an Ekind of E_Void. This will be reset in
16295 -- Record_Type_Definition after processing the record extension of
16296 -- the derived type.
16298 -- If the declaration is a private extension, there is no further
16299 -- record extension to process, and the components retain their
16300 -- current kind, because they are visible at this point.
16302 if Is_Tagged and then Ekind (New_C) = E_Component
16303 and then Nkind (N) /= N_Private_Extension_Declaration
16305 Set_Ekind (New_C, E_Void);
16308 if Plain_Discrim then
16309 Set_Corresponding_Discriminant (New_C, Old_C);
16310 Build_Discriminal (New_C);
16312 -- If we are explicitly inheriting a stored discriminant it will be
16313 -- completely hidden.
16315 elsif Stored_Discrim then
16316 Set_Corresponding_Discriminant (New_C, Empty);
16317 Set_Discriminal (New_C, Empty);
16318 Set_Is_Completely_Hidden (New_C);
16320 -- Set the Original_Record_Component of each discriminant in the
16321 -- derived base to point to the corresponding stored that we just
16324 Discrim := First_Discriminant (Derived_Base);
16325 while Present (Discrim) loop
16326 Corr_Discrim := Corresponding_Discriminant (Discrim);
16328 -- Corr_Discrim could be missing in an error situation
16330 if Present (Corr_Discrim)
16331 and then Original_Record_Component (Corr_Discrim) = Old_C
16333 Set_Original_Record_Component (Discrim, New_C);
16336 Next_Discriminant (Discrim);
16339 Append_Entity (New_C, Derived_Base);
16342 if not Is_Tagged then
16343 Append_Elmt (Old_C, Assoc_List);
16344 Append_Elmt (New_C, Assoc_List);
16346 end Inherit_Component;
16348 -- Variables local to Inherit_Component
16350 Loc : constant Source_Ptr := Sloc (N);
16352 Parent_Discrim : Entity_Id;
16353 Stored_Discrim : Entity_Id;
16355 Component : Entity_Id;
16357 -- Start of processing for Inherit_Components
16360 if not Is_Tagged then
16361 Append_Elmt (Parent_Base, Assoc_List);
16362 Append_Elmt (Derived_Base, Assoc_List);
16365 -- Inherit parent discriminants if needed
16367 if Inherit_Discr then
16368 Parent_Discrim := First_Discriminant (Parent_Base);
16369 while Present (Parent_Discrim) loop
16370 Inherit_Component (Parent_Discrim, Plain_Discrim => True);
16371 Next_Discriminant (Parent_Discrim);
16375 -- Create explicit stored discrims for untagged types when necessary
16377 if not Has_Unknown_Discriminants (Derived_Base)
16378 and then Has_Discriminants (Parent_Base)
16379 and then not Is_Tagged
16382 or else First_Discriminant (Parent_Base) /=
16383 First_Stored_Discriminant (Parent_Base))
16385 Stored_Discrim := First_Stored_Discriminant (Parent_Base);
16386 while Present (Stored_Discrim) loop
16387 Inherit_Component (Stored_Discrim, Stored_Discrim => True);
16388 Next_Stored_Discriminant (Stored_Discrim);
16392 -- See if we can apply the second transformation for derived types, as
16393 -- explained in point 6. in the comments above Build_Derived_Record_Type
16394 -- This is achieved by appending Derived_Base discriminants into Discs,
16395 -- which has the side effect of returning a non empty Discs list to the
16396 -- caller of Inherit_Components, which is what we want. This must be
16397 -- done for private derived types if there are explicit stored
16398 -- discriminants, to ensure that we can retrieve the values of the
16399 -- constraints provided in the ancestors.
16402 and then Is_Empty_Elmt_List (Discs)
16403 and then Present (First_Discriminant (Derived_Base))
16405 (not Is_Private_Type (Derived_Base)
16406 or else Is_Completely_Hidden
16407 (First_Stored_Discriminant (Derived_Base))
16408 or else Is_Generic_Type (Derived_Base))
16410 D := First_Discriminant (Derived_Base);
16411 while Present (D) loop
16412 Append_Elmt (New_Reference_To (D, Loc), Discs);
16413 Next_Discriminant (D);
16417 -- Finally, inherit non-discriminant components unless they are not
16418 -- visible because defined or inherited from the full view of the
16419 -- parent. Don't inherit the _parent field of the parent type.
16421 Component := First_Entity (Parent_Base);
16422 while Present (Component) loop
16424 -- Ada 2005 (AI-251): Do not inherit components associated with
16425 -- secondary tags of the parent.
16427 if Ekind (Component) = E_Component
16428 and then Present (Related_Type (Component))
16432 elsif Ekind (Component) /= E_Component
16433 or else Chars (Component) = Name_uParent
16437 -- If the derived type is within the parent type's declarative
16438 -- region, then the components can still be inherited even though
16439 -- they aren't visible at this point. This can occur for cases
16440 -- such as within public child units where the components must
16441 -- become visible upon entering the child unit's private part.
16443 elsif not Is_Visible_Component (Component)
16444 and then not In_Open_Scopes (Scope (Parent_Base))
16448 elsif Ekind_In (Derived_Base, E_Private_Type,
16449 E_Limited_Private_Type)
16454 Inherit_Component (Component);
16457 Next_Entity (Component);
16460 -- For tagged derived types, inherited discriminants cannot be used in
16461 -- component declarations of the record extension part. To achieve this
16462 -- we mark the inherited discriminants as not visible.
16464 if Is_Tagged and then Inherit_Discr then
16465 D := First_Discriminant (Derived_Base);
16466 while Present (D) loop
16467 Set_Is_Immediately_Visible (D, False);
16468 Next_Discriminant (D);
16473 end Inherit_Components;
16475 -----------------------
16476 -- Is_Null_Extension --
16477 -----------------------
16479 function Is_Null_Extension (T : Entity_Id) return Boolean is
16480 Type_Decl : constant Node_Id := Parent (Base_Type (T));
16481 Comp_List : Node_Id;
16485 if Nkind (Type_Decl) /= N_Full_Type_Declaration
16486 or else not Is_Tagged_Type (T)
16487 or else Nkind (Type_Definition (Type_Decl)) /=
16488 N_Derived_Type_Definition
16489 or else No (Record_Extension_Part (Type_Definition (Type_Decl)))
16495 Component_List (Record_Extension_Part (Type_Definition (Type_Decl)));
16497 if Present (Discriminant_Specifications (Type_Decl)) then
16500 elsif Present (Comp_List)
16501 and then Is_Non_Empty_List (Component_Items (Comp_List))
16503 Comp := First (Component_Items (Comp_List));
16505 -- Only user-defined components are relevant. The component list
16506 -- may also contain a parent component and internal components
16507 -- corresponding to secondary tags, but these do not determine
16508 -- whether this is a null extension.
16510 while Present (Comp) loop
16511 if Comes_From_Source (Comp) then
16522 end Is_Null_Extension;
16524 ------------------------------
16525 -- Is_Valid_Constraint_Kind --
16526 ------------------------------
16528 function Is_Valid_Constraint_Kind
16529 (T_Kind : Type_Kind;
16530 Constraint_Kind : Node_Kind) return Boolean
16534 when Enumeration_Kind |
16536 return Constraint_Kind = N_Range_Constraint;
16538 when Decimal_Fixed_Point_Kind =>
16539 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
16540 N_Range_Constraint);
16542 when Ordinary_Fixed_Point_Kind =>
16543 return Nkind_In (Constraint_Kind, N_Delta_Constraint,
16544 N_Range_Constraint);
16547 return Nkind_In (Constraint_Kind, N_Digits_Constraint,
16548 N_Range_Constraint);
16555 E_Incomplete_Type |
16558 return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
16561 return True; -- Error will be detected later
16563 end Is_Valid_Constraint_Kind;
16565 --------------------------
16566 -- Is_Visible_Component --
16567 --------------------------
16569 function Is_Visible_Component
16571 N : Node_Id := Empty) return Boolean
16573 Original_Comp : Entity_Id := Empty;
16574 Original_Scope : Entity_Id;
16575 Type_Scope : Entity_Id;
16577 function Is_Local_Type (Typ : Entity_Id) return Boolean;
16578 -- Check whether parent type of inherited component is declared locally,
16579 -- possibly within a nested package or instance. The current scope is
16580 -- the derived record itself.
16582 -------------------
16583 -- Is_Local_Type --
16584 -------------------
16586 function Is_Local_Type (Typ : Entity_Id) return Boolean is
16590 Scop := Scope (Typ);
16591 while Present (Scop)
16592 and then Scop /= Standard_Standard
16594 if Scop = Scope (Current_Scope) then
16598 Scop := Scope (Scop);
16604 -- Start of processing for Is_Visible_Component
16607 if Ekind_In (C, E_Component, E_Discriminant) then
16608 Original_Comp := Original_Record_Component (C);
16611 if No (Original_Comp) then
16613 -- Premature usage, or previous error
16618 Original_Scope := Scope (Original_Comp);
16619 Type_Scope := Scope (Base_Type (Scope (C)));
16622 -- For an untagged type derived from a private type, the only visible
16623 -- components are new discriminants. In an instance all components are
16624 -- visible (see Analyze_Selected_Component).
16626 if not Is_Tagged_Type (Original_Scope) then
16627 return not Has_Private_Ancestor (Original_Scope)
16628 or else In_Open_Scopes (Scope (Original_Scope))
16629 or else In_Instance
16630 or else (Ekind (Original_Comp) = E_Discriminant
16631 and then Original_Scope = Type_Scope);
16633 -- If it is _Parent or _Tag, there is no visibility issue
16635 elsif not Comes_From_Source (Original_Comp) then
16638 -- Discriminants are visible unless the (private) type has unknown
16639 -- discriminants. If the discriminant reference is inserted for a
16640 -- discriminant check on a full view it is also visible.
16642 elsif Ekind (Original_Comp) = E_Discriminant
16644 (not Has_Unknown_Discriminants (Original_Scope)
16645 or else (Present (N)
16646 and then Nkind (N) = N_Selected_Component
16647 and then Nkind (Prefix (N)) = N_Type_Conversion
16648 and then not Comes_From_Source (Prefix (N))))
16652 -- In the body of an instantiation, no need to check for the visibility
16655 elsif In_Instance_Body then
16658 -- If the component has been declared in an ancestor which is currently
16659 -- a private type, then it is not visible. The same applies if the
16660 -- component's containing type is not in an open scope and the original
16661 -- component's enclosing type is a visible full view of a private type
16662 -- (which can occur in cases where an attempt is being made to reference
16663 -- a component in a sibling package that is inherited from a visible
16664 -- component of a type in an ancestor package; the component in the
16665 -- sibling package should not be visible even though the component it
16666 -- inherited from is visible). This does not apply however in the case
16667 -- where the scope of the type is a private child unit, or when the
16668 -- parent comes from a local package in which the ancestor is currently
16669 -- visible. The latter suppression of visibility is needed for cases
16670 -- that are tested in B730006.
16672 elsif Is_Private_Type (Original_Scope)
16674 (not Is_Private_Descendant (Type_Scope)
16675 and then not In_Open_Scopes (Type_Scope)
16676 and then Has_Private_Declaration (Original_Scope))
16678 -- If the type derives from an entity in a formal package, there
16679 -- are no additional visible components.
16681 if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
16682 N_Formal_Package_Declaration
16686 -- if we are not in the private part of the current package, there
16687 -- are no additional visible components.
16689 elsif Ekind (Scope (Current_Scope)) = E_Package
16690 and then not In_Private_Part (Scope (Current_Scope))
16695 Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
16696 and then In_Open_Scopes (Scope (Original_Scope))
16697 and then Is_Local_Type (Type_Scope);
16700 -- There is another weird way in which a component may be invisible when
16701 -- the private and the full view are not derived from the same ancestor.
16702 -- Here is an example :
16704 -- type A1 is tagged record F1 : integer; end record;
16705 -- type A2 is new A1 with record F2 : integer; end record;
16706 -- type T is new A1 with private;
16708 -- type T is new A2 with null record;
16710 -- In this case, the full view of T inherits F1 and F2 but the private
16711 -- view inherits only F1
16715 Ancestor : Entity_Id := Scope (C);
16719 if Ancestor = Original_Scope then
16721 elsif Ancestor = Etype (Ancestor) then
16725 Ancestor := Etype (Ancestor);
16729 end Is_Visible_Component;
16731 --------------------------
16732 -- Make_Class_Wide_Type --
16733 --------------------------
16735 procedure Make_Class_Wide_Type (T : Entity_Id) is
16736 CW_Type : Entity_Id;
16738 Next_E : Entity_Id;
16741 if Present (Class_Wide_Type (T)) then
16743 -- The class-wide type is a partially decorated entity created for a
16744 -- unanalyzed tagged type referenced through a limited with clause.
16745 -- When the tagged type is analyzed, its class-wide type needs to be
16746 -- redecorated. Note that we reuse the entity created by Decorate_
16747 -- Tagged_Type in order to preserve all links.
16749 if Materialize_Entity (Class_Wide_Type (T)) then
16750 CW_Type := Class_Wide_Type (T);
16751 Set_Materialize_Entity (CW_Type, False);
16753 -- The class wide type can have been defined by the partial view, in
16754 -- which case everything is already done.
16760 -- Default case, we need to create a new class-wide type
16764 New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
16767 -- Inherit root type characteristics
16769 CW_Name := Chars (CW_Type);
16770 Next_E := Next_Entity (CW_Type);
16771 Copy_Node (T, CW_Type);
16772 Set_Comes_From_Source (CW_Type, False);
16773 Set_Chars (CW_Type, CW_Name);
16774 Set_Parent (CW_Type, Parent (T));
16775 Set_Next_Entity (CW_Type, Next_E);
16777 -- Ensure we have a new freeze node for the class-wide type. The partial
16778 -- view may have freeze action of its own, requiring a proper freeze
16779 -- node, and the same freeze node cannot be shared between the two
16782 Set_Has_Delayed_Freeze (CW_Type);
16783 Set_Freeze_Node (CW_Type, Empty);
16785 -- Customize the class-wide type: It has no prim. op., it cannot be
16786 -- abstract and its Etype points back to the specific root type.
16788 Set_Ekind (CW_Type, E_Class_Wide_Type);
16789 Set_Is_Tagged_Type (CW_Type, True);
16790 Set_Direct_Primitive_Operations (CW_Type, New_Elmt_List);
16791 Set_Is_Abstract_Type (CW_Type, False);
16792 Set_Is_Constrained (CW_Type, False);
16793 Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
16795 if Ekind (T) = E_Class_Wide_Subtype then
16796 Set_Etype (CW_Type, Etype (Base_Type (T)));
16798 Set_Etype (CW_Type, T);
16801 -- If this is the class_wide type of a constrained subtype, it does
16802 -- not have discriminants.
16804 Set_Has_Discriminants (CW_Type,
16805 Has_Discriminants (T) and then not Is_Constrained (T));
16807 Set_Has_Unknown_Discriminants (CW_Type, True);
16808 Set_Class_Wide_Type (T, CW_Type);
16809 Set_Equivalent_Type (CW_Type, Empty);
16811 -- The class-wide type of a class-wide type is itself (RM 3.9(14))
16813 Set_Class_Wide_Type (CW_Type, CW_Type);
16814 end Make_Class_Wide_Type;
16820 procedure Make_Index
16822 Related_Nod : Node_Id;
16823 Related_Id : Entity_Id := Empty;
16824 Suffix_Index : Nat := 1;
16825 In_Iter_Schm : Boolean := False)
16829 Def_Id : Entity_Id := Empty;
16830 Found : Boolean := False;
16833 -- For a discrete range used in a constrained array definition and
16834 -- defined by a range, an implicit conversion to the predefined type
16835 -- INTEGER is assumed if each bound is either a numeric literal, a named
16836 -- number, or an attribute, and the type of both bounds (prior to the
16837 -- implicit conversion) is the type universal_integer. Otherwise, both
16838 -- bounds must be of the same discrete type, other than universal
16839 -- integer; this type must be determinable independently of the
16840 -- context, but using the fact that the type must be discrete and that
16841 -- both bounds must have the same type.
16843 -- Character literals also have a universal type in the absence of
16844 -- of additional context, and are resolved to Standard_Character.
16846 if Nkind (I) = N_Range then
16848 -- The index is given by a range constraint. The bounds are known
16849 -- to be of a consistent type.
16851 if not Is_Overloaded (I) then
16854 -- For universal bounds, choose the specific predefined type
16856 if T = Universal_Integer then
16857 T := Standard_Integer;
16859 elsif T = Any_Character then
16860 Ambiguous_Character (Low_Bound (I));
16862 T := Standard_Character;
16865 -- The node may be overloaded because some user-defined operators
16866 -- are available, but if a universal interpretation exists it is
16867 -- also the selected one.
16869 elsif Universal_Interpretation (I) = Universal_Integer then
16870 T := Standard_Integer;
16876 Ind : Interp_Index;
16880 Get_First_Interp (I, Ind, It);
16881 while Present (It.Typ) loop
16882 if Is_Discrete_Type (It.Typ) then
16885 and then not Covers (It.Typ, T)
16886 and then not Covers (T, It.Typ)
16888 Error_Msg_N ("ambiguous bounds in discrete range", I);
16896 Get_Next_Interp (Ind, It);
16899 if T = Any_Type then
16900 Error_Msg_N ("discrete type required for range", I);
16901 Set_Etype (I, Any_Type);
16904 elsif T = Universal_Integer then
16905 T := Standard_Integer;
16910 if not Is_Discrete_Type (T) then
16911 Error_Msg_N ("discrete type required for range", I);
16912 Set_Etype (I, Any_Type);
16916 if Nkind (Low_Bound (I)) = N_Attribute_Reference
16917 and then Attribute_Name (Low_Bound (I)) = Name_First
16918 and then Is_Entity_Name (Prefix (Low_Bound (I)))
16919 and then Is_Type (Entity (Prefix (Low_Bound (I))))
16920 and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I))))
16922 -- The type of the index will be the type of the prefix, as long
16923 -- as the upper bound is 'Last of the same type.
16925 Def_Id := Entity (Prefix (Low_Bound (I)));
16927 if Nkind (High_Bound (I)) /= N_Attribute_Reference
16928 or else Attribute_Name (High_Bound (I)) /= Name_Last
16929 or else not Is_Entity_Name (Prefix (High_Bound (I)))
16930 or else Entity (Prefix (High_Bound (I))) /= Def_Id
16937 Process_Range_Expr_In_Decl (R, T, In_Iter_Schm => In_Iter_Schm);
16939 elsif Nkind (I) = N_Subtype_Indication then
16941 -- The index is given by a subtype with a range constraint
16943 T := Base_Type (Entity (Subtype_Mark (I)));
16945 if not Is_Discrete_Type (T) then
16946 Error_Msg_N ("discrete type required for range", I);
16947 Set_Etype (I, Any_Type);
16951 R := Range_Expression (Constraint (I));
16954 Process_Range_Expr_In_Decl
16955 (R, Entity (Subtype_Mark (I)), In_Iter_Schm => In_Iter_Schm);
16957 elsif Nkind (I) = N_Attribute_Reference then
16959 -- The parser guarantees that the attribute is a RANGE attribute
16961 -- If the node denotes the range of a type mark, that is also the
16962 -- resulting type, and we do no need to create an Itype for it.
16964 if Is_Entity_Name (Prefix (I))
16965 and then Comes_From_Source (I)
16966 and then Is_Type (Entity (Prefix (I)))
16967 and then Is_Discrete_Type (Entity (Prefix (I)))
16969 Def_Id := Entity (Prefix (I));
16972 Analyze_And_Resolve (I);
16976 -- If none of the above, must be a subtype. We convert this to a
16977 -- range attribute reference because in the case of declared first
16978 -- named subtypes, the types in the range reference can be different
16979 -- from the type of the entity. A range attribute normalizes the
16980 -- reference and obtains the correct types for the bounds.
16982 -- This transformation is in the nature of an expansion, is only
16983 -- done if expansion is active. In particular, it is not done on
16984 -- formal generic types, because we need to retain the name of the
16985 -- original index for instantiation purposes.
16988 if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
16989 Error_Msg_N ("invalid subtype mark in discrete range ", I);
16990 Set_Etype (I, Any_Integer);
16994 -- The type mark may be that of an incomplete type. It is only
16995 -- now that we can get the full view, previous analysis does
16996 -- not look specifically for a type mark.
16998 Set_Entity (I, Get_Full_View (Entity (I)));
16999 Set_Etype (I, Entity (I));
17000 Def_Id := Entity (I);
17002 if not Is_Discrete_Type (Def_Id) then
17003 Error_Msg_N ("discrete type required for index", I);
17004 Set_Etype (I, Any_Type);
17009 if Expander_Active then
17011 Make_Attribute_Reference (Sloc (I),
17012 Attribute_Name => Name_Range,
17013 Prefix => Relocate_Node (I)));
17015 -- The original was a subtype mark that does not freeze. This
17016 -- means that the rewritten version must not freeze either.
17018 Set_Must_Not_Freeze (I);
17019 Set_Must_Not_Freeze (Prefix (I));
17020 Analyze_And_Resolve (I);
17024 -- If expander is inactive, type is legal, nothing else to construct
17031 if not Is_Discrete_Type (T) then
17032 Error_Msg_N ("discrete type required for range", I);
17033 Set_Etype (I, Any_Type);
17036 elsif T = Any_Type then
17037 Set_Etype (I, Any_Type);
17041 -- We will now create the appropriate Itype to describe the range, but
17042 -- first a check. If we originally had a subtype, then we just label
17043 -- the range with this subtype. Not only is there no need to construct
17044 -- a new subtype, but it is wrong to do so for two reasons:
17046 -- 1. A legality concern, if we have a subtype, it must not freeze,
17047 -- and the Itype would cause freezing incorrectly
17049 -- 2. An efficiency concern, if we created an Itype, it would not be
17050 -- recognized as the same type for the purposes of eliminating
17051 -- checks in some circumstances.
17053 -- We signal this case by setting the subtype entity in Def_Id
17055 if No (Def_Id) then
17057 Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
17058 Set_Etype (Def_Id, Base_Type (T));
17060 if Is_Signed_Integer_Type (T) then
17061 Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
17063 elsif Is_Modular_Integer_Type (T) then
17064 Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
17067 Set_Ekind (Def_Id, E_Enumeration_Subtype);
17068 Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
17069 Set_First_Literal (Def_Id, First_Literal (T));
17072 Set_Size_Info (Def_Id, (T));
17073 Set_RM_Size (Def_Id, RM_Size (T));
17074 Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
17076 Set_Scalar_Range (Def_Id, R);
17077 Conditional_Delay (Def_Id, T);
17079 -- In the subtype indication case, if the immediate parent of the
17080 -- new subtype is non-static, then the subtype we create is non-
17081 -- static, even if its bounds are static.
17083 if Nkind (I) = N_Subtype_Indication
17084 and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
17086 Set_Is_Non_Static_Subtype (Def_Id);
17090 -- Final step is to label the index with this constructed type
17092 Set_Etype (I, Def_Id);
17095 ------------------------------
17096 -- Modular_Type_Declaration --
17097 ------------------------------
17099 procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
17100 Mod_Expr : constant Node_Id := Expression (Def);
17103 procedure Set_Modular_Size (Bits : Int);
17104 -- Sets RM_Size to Bits, and Esize to normal word size above this
17106 ----------------------
17107 -- Set_Modular_Size --
17108 ----------------------
17110 procedure Set_Modular_Size (Bits : Int) is
17112 Set_RM_Size (T, UI_From_Int (Bits));
17117 elsif Bits <= 16 then
17118 Init_Esize (T, 16);
17120 elsif Bits <= 32 then
17121 Init_Esize (T, 32);
17124 Init_Esize (T, System_Max_Binary_Modulus_Power);
17127 if not Non_Binary_Modulus (T)
17128 and then Esize (T) = RM_Size (T)
17130 Set_Is_Known_Valid (T);
17132 end Set_Modular_Size;
17134 -- Start of processing for Modular_Type_Declaration
17137 -- If the mod expression is (exactly) 2 * literal, where literal is
17138 -- 64 or less,then almost certainly the * was meant to be **. Warn!
17140 if Warn_On_Suspicious_Modulus_Value
17141 and then Nkind (Mod_Expr) = N_Op_Multiply
17142 and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal
17143 and then Intval (Left_Opnd (Mod_Expr)) = Uint_2
17144 and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal
17145 and then Intval (Right_Opnd (Mod_Expr)) <= Uint_64
17148 ("suspicious MOD value, was '*'* intended'??M?", Mod_Expr);
17151 -- Proceed with analysis of mod expression
17153 Analyze_And_Resolve (Mod_Expr, Any_Integer);
17155 Set_Ekind (T, E_Modular_Integer_Type);
17156 Init_Alignment (T);
17157 Set_Is_Constrained (T);
17159 if not Is_OK_Static_Expression (Mod_Expr) then
17160 Flag_Non_Static_Expr
17161 ("non-static expression used for modular type bound!", Mod_Expr);
17162 M_Val := 2 ** System_Max_Binary_Modulus_Power;
17164 M_Val := Expr_Value (Mod_Expr);
17168 Error_Msg_N ("modulus value must be positive", Mod_Expr);
17169 M_Val := 2 ** System_Max_Binary_Modulus_Power;
17172 Set_Modulus (T, M_Val);
17174 -- Create bounds for the modular type based on the modulus given in
17175 -- the type declaration and then analyze and resolve those bounds.
17177 Set_Scalar_Range (T,
17178 Make_Range (Sloc (Mod_Expr),
17179 Low_Bound => Make_Integer_Literal (Sloc (Mod_Expr), 0),
17180 High_Bound => Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
17182 -- Properly analyze the literals for the range. We do this manually
17183 -- because we can't go calling Resolve, since we are resolving these
17184 -- bounds with the type, and this type is certainly not complete yet!
17186 Set_Etype (Low_Bound (Scalar_Range (T)), T);
17187 Set_Etype (High_Bound (Scalar_Range (T)), T);
17188 Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
17189 Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
17191 -- Loop through powers of two to find number of bits required
17193 for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
17197 if M_Val = 2 ** Bits then
17198 Set_Modular_Size (Bits);
17203 elsif M_Val < 2 ** Bits then
17204 Check_SPARK_Restriction ("modulus should be a power of 2", T);
17205 Set_Non_Binary_Modulus (T);
17207 if Bits > System_Max_Nonbinary_Modulus_Power then
17208 Error_Msg_Uint_1 :=
17209 UI_From_Int (System_Max_Nonbinary_Modulus_Power);
17211 ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
17212 Set_Modular_Size (System_Max_Binary_Modulus_Power);
17216 -- In the non-binary case, set size as per RM 13.3(55)
17218 Set_Modular_Size (Bits);
17225 -- If we fall through, then the size exceed System.Max_Binary_Modulus
17226 -- so we just signal an error and set the maximum size.
17228 Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
17229 Error_Msg_F ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
17231 Set_Modular_Size (System_Max_Binary_Modulus_Power);
17232 Init_Alignment (T);
17234 end Modular_Type_Declaration;
17236 --------------------------
17237 -- New_Concatenation_Op --
17238 --------------------------
17240 procedure New_Concatenation_Op (Typ : Entity_Id) is
17241 Loc : constant Source_Ptr := Sloc (Typ);
17244 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
17245 -- Create abbreviated declaration for the formal of a predefined
17246 -- Operator 'Op' of type 'Typ'
17248 --------------------
17249 -- Make_Op_Formal --
17250 --------------------
17252 function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
17253 Formal : Entity_Id;
17255 Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
17256 Set_Etype (Formal, Typ);
17257 Set_Mechanism (Formal, Default_Mechanism);
17259 end Make_Op_Formal;
17261 -- Start of processing for New_Concatenation_Op
17264 Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
17266 Set_Ekind (Op, E_Operator);
17267 Set_Scope (Op, Current_Scope);
17268 Set_Etype (Op, Typ);
17269 Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
17270 Set_Is_Immediately_Visible (Op);
17271 Set_Is_Intrinsic_Subprogram (Op);
17272 Set_Has_Completion (Op);
17273 Append_Entity (Op, Current_Scope);
17275 Set_Name_Entity_Id (Name_Op_Concat, Op);
17277 Append_Entity (Make_Op_Formal (Typ, Op), Op);
17278 Append_Entity (Make_Op_Formal (Typ, Op), Op);
17279 end New_Concatenation_Op;
17281 -------------------------
17282 -- OK_For_Limited_Init --
17283 -------------------------
17285 -- ???Check all calls of this, and compare the conditions under which it's
17288 function OK_For_Limited_Init
17290 Exp : Node_Id) return Boolean
17293 return Is_CPP_Constructor_Call (Exp)
17294 or else (Ada_Version >= Ada_2005
17295 and then not Debug_Flag_Dot_L
17296 and then OK_For_Limited_Init_In_05 (Typ, Exp));
17297 end OK_For_Limited_Init;
17299 -------------------------------
17300 -- OK_For_Limited_Init_In_05 --
17301 -------------------------------
17303 function OK_For_Limited_Init_In_05
17305 Exp : Node_Id) return Boolean
17308 -- An object of a limited interface type can be initialized with any
17309 -- expression of a nonlimited descendant type.
17311 if Is_Class_Wide_Type (Typ)
17312 and then Is_Limited_Interface (Typ)
17313 and then not Is_Limited_Type (Etype (Exp))
17318 -- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in
17319 -- case of limited aggregates (including extension aggregates), and
17320 -- function calls. The function call may have been given in prefixed
17321 -- notation, in which case the original node is an indexed component.
17322 -- If the function is parameterless, the original node was an explicit
17323 -- dereference. The function may also be parameterless, in which case
17324 -- the source node is just an identifier.
17326 case Nkind (Original_Node (Exp)) is
17327 when N_Aggregate | N_Extension_Aggregate | N_Function_Call | N_Op =>
17330 when N_Identifier =>
17331 return Present (Entity (Original_Node (Exp)))
17332 and then Ekind (Entity (Original_Node (Exp))) = E_Function;
17334 when N_Qualified_Expression =>
17336 OK_For_Limited_Init_In_05
17337 (Typ, Expression (Original_Node (Exp)));
17339 -- Ada 2005 (AI-251): If a class-wide interface object is initialized
17340 -- with a function call, the expander has rewritten the call into an
17341 -- N_Type_Conversion node to force displacement of the pointer to
17342 -- reference the component containing the secondary dispatch table.
17343 -- Otherwise a type conversion is not a legal context.
17344 -- A return statement for a build-in-place function returning a
17345 -- synchronized type also introduces an unchecked conversion.
17347 when N_Type_Conversion |
17348 N_Unchecked_Type_Conversion =>
17349 return not Comes_From_Source (Exp)
17351 OK_For_Limited_Init_In_05
17352 (Typ, Expression (Original_Node (Exp)));
17354 when N_Indexed_Component |
17355 N_Selected_Component |
17356 N_Explicit_Dereference =>
17357 return Nkind (Exp) = N_Function_Call;
17359 -- A use of 'Input is a function call, hence allowed. Normally the
17360 -- attribute will be changed to a call, but the attribute by itself
17361 -- can occur with -gnatc.
17363 when N_Attribute_Reference =>
17364 return Attribute_Name (Original_Node (Exp)) = Name_Input;
17366 -- For a case expression, all dependent expressions must be legal
17368 when N_Case_Expression =>
17373 Alt := First (Alternatives (Original_Node (Exp)));
17374 while Present (Alt) loop
17375 if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then
17385 -- For an if expression, all dependent expressions must be legal
17387 when N_If_Expression =>
17389 Then_Expr : constant Node_Id :=
17390 Next (First (Expressions (Original_Node (Exp))));
17391 Else_Expr : constant Node_Id := Next (Then_Expr);
17393 return OK_For_Limited_Init_In_05 (Typ, Then_Expr)
17395 OK_For_Limited_Init_In_05 (Typ, Else_Expr);
17401 end OK_For_Limited_Init_In_05;
17403 -------------------------------------------
17404 -- Ordinary_Fixed_Point_Type_Declaration --
17405 -------------------------------------------
17407 procedure Ordinary_Fixed_Point_Type_Declaration
17411 Loc : constant Source_Ptr := Sloc (Def);
17412 Delta_Expr : constant Node_Id := Delta_Expression (Def);
17413 RRS : constant Node_Id := Real_Range_Specification (Def);
17414 Implicit_Base : Entity_Id;
17421 Check_Restriction (No_Fixed_Point, Def);
17423 -- Create implicit base type
17426 Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
17427 Set_Etype (Implicit_Base, Implicit_Base);
17429 -- Analyze and process delta expression
17431 Analyze_And_Resolve (Delta_Expr, Any_Real);
17433 Check_Delta_Expression (Delta_Expr);
17434 Delta_Val := Expr_Value_R (Delta_Expr);
17436 Set_Delta_Value (Implicit_Base, Delta_Val);
17438 -- Compute default small from given delta, which is the largest power
17439 -- of two that does not exceed the given delta value.
17449 if Delta_Val < Ureal_1 then
17450 while Delta_Val < Tmp loop
17451 Tmp := Tmp / Ureal_2;
17452 Scale := Scale + 1;
17457 Tmp := Tmp * Ureal_2;
17458 exit when Tmp > Delta_Val;
17459 Scale := Scale - 1;
17463 Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
17466 Set_Small_Value (Implicit_Base, Small_Val);
17468 -- If no range was given, set a dummy range
17470 if RRS <= Empty_Or_Error then
17471 Low_Val := -Small_Val;
17472 High_Val := Small_Val;
17474 -- Otherwise analyze and process given range
17478 Low : constant Node_Id := Low_Bound (RRS);
17479 High : constant Node_Id := High_Bound (RRS);
17482 Analyze_And_Resolve (Low, Any_Real);
17483 Analyze_And_Resolve (High, Any_Real);
17484 Check_Real_Bound (Low);
17485 Check_Real_Bound (High);
17487 -- Obtain and set the range
17489 Low_Val := Expr_Value_R (Low);
17490 High_Val := Expr_Value_R (High);
17492 if Low_Val > High_Val then
17493 Error_Msg_NE ("??fixed point type& has null range", Def, T);
17498 -- The range for both the implicit base and the declared first subtype
17499 -- cannot be set yet, so we use the special routine Set_Fixed_Range to
17500 -- set a temporary range in place. Note that the bounds of the base
17501 -- type will be widened to be symmetrical and to fill the available
17502 -- bits when the type is frozen.
17504 -- We could do this with all discrete types, and probably should, but
17505 -- we absolutely have to do it for fixed-point, since the end-points
17506 -- of the range and the size are determined by the small value, which
17507 -- could be reset before the freeze point.
17509 Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
17510 Set_Fixed_Range (T, Loc, Low_Val, High_Val);
17512 -- Complete definition of first subtype
17514 Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
17515 Set_Etype (T, Implicit_Base);
17516 Init_Size_Align (T);
17517 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
17518 Set_Small_Value (T, Small_Val);
17519 Set_Delta_Value (T, Delta_Val);
17520 Set_Is_Constrained (T);
17522 end Ordinary_Fixed_Point_Type_Declaration;
17524 ----------------------------------------
17525 -- Prepare_Private_Subtype_Completion --
17526 ----------------------------------------
17528 procedure Prepare_Private_Subtype_Completion
17530 Related_Nod : Node_Id)
17532 Id_B : constant Entity_Id := Base_Type (Id);
17533 Full_B : constant Entity_Id := Full_View (Id_B);
17537 if Present (Full_B) then
17539 -- The Base_Type is already completed, we can complete the subtype
17540 -- now. We have to create a new entity with the same name, Thus we
17541 -- can't use Create_Itype.
17543 Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
17544 Set_Is_Itype (Full);
17545 Set_Associated_Node_For_Itype (Full, Related_Nod);
17546 Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
17549 -- The parent subtype may be private, but the base might not, in some
17550 -- nested instances. In that case, the subtype does not need to be
17551 -- exchanged. It would still be nice to make private subtypes and their
17552 -- bases consistent at all times ???
17554 if Is_Private_Type (Id_B) then
17555 Append_Elmt (Id, Private_Dependents (Id_B));
17557 end Prepare_Private_Subtype_Completion;
17559 ---------------------------
17560 -- Process_Discriminants --
17561 ---------------------------
17563 procedure Process_Discriminants
17565 Prev : Entity_Id := Empty)
17567 Elist : constant Elist_Id := New_Elmt_List;
17570 Discr_Number : Uint;
17571 Discr_Type : Entity_Id;
17572 Default_Present : Boolean := False;
17573 Default_Not_Present : Boolean := False;
17576 -- A composite type other than an array type can have discriminants.
17577 -- On entry, the current scope is the composite type.
17579 -- The discriminants are initially entered into the scope of the type
17580 -- via Enter_Name with the default Ekind of E_Void to prevent premature
17581 -- use, as explained at the end of this procedure.
17583 Discr := First (Discriminant_Specifications (N));
17584 while Present (Discr) loop
17585 Enter_Name (Defining_Identifier (Discr));
17587 -- For navigation purposes we add a reference to the discriminant
17588 -- in the entity for the type. If the current declaration is a
17589 -- completion, place references on the partial view. Otherwise the
17590 -- type is the current scope.
17592 if Present (Prev) then
17594 -- The references go on the partial view, if present. If the
17595 -- partial view has discriminants, the references have been
17596 -- generated already.
17598 if not Has_Discriminants (Prev) then
17599 Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
17603 (Current_Scope, Defining_Identifier (Discr), 'd');
17606 if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
17607 Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr));
17609 -- Ada 2005 (AI-254)
17611 if Present (Access_To_Subprogram_Definition
17612 (Discriminant_Type (Discr)))
17613 and then Protected_Present (Access_To_Subprogram_Definition
17614 (Discriminant_Type (Discr)))
17617 Replace_Anonymous_Access_To_Protected_Subprogram (Discr);
17621 Find_Type (Discriminant_Type (Discr));
17622 Discr_Type := Etype (Discriminant_Type (Discr));
17624 if Error_Posted (Discriminant_Type (Discr)) then
17625 Discr_Type := Any_Type;
17629 if Is_Access_Type (Discr_Type) then
17631 -- Ada 2005 (AI-230): Access discriminant allowed in non-limited
17634 if Ada_Version < Ada_2005 then
17635 Check_Access_Discriminant_Requires_Limited
17636 (Discr, Discriminant_Type (Discr));
17639 if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
17641 ("(Ada 83) access discriminant not allowed", Discr);
17644 elsif not Is_Discrete_Type (Discr_Type) then
17645 Error_Msg_N ("discriminants must have a discrete or access type",
17646 Discriminant_Type (Discr));
17649 Set_Etype (Defining_Identifier (Discr), Discr_Type);
17651 -- If a discriminant specification includes the assignment compound
17652 -- delimiter followed by an expression, the expression is the default
17653 -- expression of the discriminant; the default expression must be of
17654 -- the type of the discriminant. (RM 3.7.1) Since this expression is
17655 -- a default expression, we do the special preanalysis, since this
17656 -- expression does not freeze (see "Handling of Default and Per-
17657 -- Object Expressions" in spec of package Sem).
17659 if Present (Expression (Discr)) then
17660 Preanalyze_Spec_Expression (Expression (Discr), Discr_Type);
17662 if Nkind (N) = N_Formal_Type_Declaration then
17664 ("discriminant defaults not allowed for formal type",
17665 Expression (Discr));
17667 -- Flag an error for a tagged type with defaulted discriminants,
17668 -- excluding limited tagged types when compiling for Ada 2012
17669 -- (see AI05-0214).
17671 elsif Is_Tagged_Type (Current_Scope)
17672 and then (not Is_Limited_Type (Current_Scope)
17673 or else Ada_Version < Ada_2012)
17674 and then Comes_From_Source (N)
17676 -- Note: see similar test in Check_Or_Process_Discriminants, to
17677 -- handle the (illegal) case of the completion of an untagged
17678 -- view with discriminants with defaults by a tagged full view.
17679 -- We skip the check if Discr does not come from source, to
17680 -- account for the case of an untagged derived type providing
17681 -- defaults for a renamed discriminant from a private untagged
17682 -- ancestor with a tagged full view (ACATS B460006).
17684 if Ada_Version >= Ada_2012 then
17686 ("discriminants of nonlimited tagged type cannot have"
17688 Expression (Discr));
17691 ("discriminants of tagged type cannot have defaults",
17692 Expression (Discr));
17696 Default_Present := True;
17697 Append_Elmt (Expression (Discr), Elist);
17699 -- Tag the defining identifiers for the discriminants with
17700 -- their corresponding default expressions from the tree.
17702 Set_Discriminant_Default_Value
17703 (Defining_Identifier (Discr), Expression (Discr));
17707 Default_Not_Present := True;
17710 -- Ada 2005 (AI-231): Create an Itype that is a duplicate of
17711 -- Discr_Type but with the null-exclusion attribute
17713 if Ada_Version >= Ada_2005 then
17715 -- Ada 2005 (AI-231): Static checks
17717 if Can_Never_Be_Null (Discr_Type) then
17718 Null_Exclusion_Static_Checks (Discr);
17720 elsif Is_Access_Type (Discr_Type)
17721 and then Null_Exclusion_Present (Discr)
17723 -- No need to check itypes because in their case this check
17724 -- was done at their point of creation
17726 and then not Is_Itype (Discr_Type)
17728 if Can_Never_Be_Null (Discr_Type) then
17730 ("`NOT NULL` not allowed (& already excludes null)",
17735 Set_Etype (Defining_Identifier (Discr),
17736 Create_Null_Excluding_Itype
17738 Related_Nod => Discr));
17740 -- Check for improper null exclusion if the type is otherwise
17741 -- legal for a discriminant.
17743 elsif Null_Exclusion_Present (Discr)
17744 and then Is_Discrete_Type (Discr_Type)
17747 ("null exclusion can only apply to an access type", Discr);
17750 -- Ada 2005 (AI-402): access discriminants of nonlimited types
17751 -- can't have defaults. Synchronized types, or types that are
17752 -- explicitly limited are fine, but special tests apply to derived
17753 -- types in generics: in a generic body we have to assume the
17754 -- worst, and therefore defaults are not allowed if the parent is
17755 -- a generic formal private type (see ACATS B370001).
17757 if Is_Access_Type (Discr_Type) and then Default_Present then
17758 if Ekind (Discr_Type) /= E_Anonymous_Access_Type
17759 or else Is_Limited_Record (Current_Scope)
17760 or else Is_Concurrent_Type (Current_Scope)
17761 or else Is_Concurrent_Record_Type (Current_Scope)
17762 or else Ekind (Current_Scope) = E_Limited_Private_Type
17764 if not Is_Derived_Type (Current_Scope)
17765 or else not Is_Generic_Type (Etype (Current_Scope))
17766 or else not In_Package_Body (Scope (Etype (Current_Scope)))
17767 or else Limited_Present
17768 (Type_Definition (Parent (Current_Scope)))
17773 Error_Msg_N ("access discriminants of nonlimited types",
17774 Expression (Discr));
17775 Error_Msg_N ("\cannot have defaults", Expression (Discr));
17778 elsif Present (Expression (Discr)) then
17780 ("(Ada 2005) access discriminants of nonlimited types",
17781 Expression (Discr));
17782 Error_Msg_N ("\cannot have defaults", Expression (Discr));
17790 -- An element list consisting of the default expressions of the
17791 -- discriminants is constructed in the above loop and used to set
17792 -- the Discriminant_Constraint attribute for the type. If an object
17793 -- is declared of this (record or task) type without any explicit
17794 -- discriminant constraint given, this element list will form the
17795 -- actual parameters for the corresponding initialization procedure
17798 Set_Discriminant_Constraint (Current_Scope, Elist);
17799 Set_Stored_Constraint (Current_Scope, No_Elist);
17801 -- Default expressions must be provided either for all or for none
17802 -- of the discriminants of a discriminant part. (RM 3.7.1)
17804 if Default_Present and then Default_Not_Present then
17806 ("incomplete specification of defaults for discriminants", N);
17809 -- The use of the name of a discriminant is not allowed in default
17810 -- expressions of a discriminant part if the specification of the
17811 -- discriminant is itself given in the discriminant part. (RM 3.7.1)
17813 -- To detect this, the discriminant names are entered initially with an
17814 -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
17815 -- attempt to use a void entity (for example in an expression that is
17816 -- type-checked) produces the error message: premature usage. Now after
17817 -- completing the semantic analysis of the discriminant part, we can set
17818 -- the Ekind of all the discriminants appropriately.
17820 Discr := First (Discriminant_Specifications (N));
17821 Discr_Number := Uint_1;
17822 while Present (Discr) loop
17823 Id := Defining_Identifier (Discr);
17824 Set_Ekind (Id, E_Discriminant);
17825 Init_Component_Location (Id);
17827 Set_Discriminant_Number (Id, Discr_Number);
17829 -- Make sure this is always set, even in illegal programs
17831 Set_Corresponding_Discriminant (Id, Empty);
17833 -- Initialize the Original_Record_Component to the entity itself.
17834 -- Inherit_Components will propagate the right value to
17835 -- discriminants in derived record types.
17837 Set_Original_Record_Component (Id, Id);
17839 -- Create the discriminal for the discriminant
17841 Build_Discriminal (Id);
17844 Discr_Number := Discr_Number + 1;
17847 Set_Has_Discriminants (Current_Scope);
17848 end Process_Discriminants;
17850 -----------------------
17851 -- Process_Full_View --
17852 -----------------------
17854 procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
17855 Priv_Parent : Entity_Id;
17856 Full_Parent : Entity_Id;
17857 Full_Indic : Node_Id;
17859 procedure Collect_Implemented_Interfaces
17861 Ifaces : Elist_Id);
17862 -- Ada 2005: Gather all the interfaces that Typ directly or
17863 -- inherently implements. Duplicate entries are not added to
17864 -- the list Ifaces.
17866 ------------------------------------
17867 -- Collect_Implemented_Interfaces --
17868 ------------------------------------
17870 procedure Collect_Implemented_Interfaces
17875 Iface_Elmt : Elmt_Id;
17878 -- Abstract interfaces are only associated with tagged record types
17880 if not Is_Tagged_Type (Typ)
17881 or else not Is_Record_Type (Typ)
17886 -- Recursively climb to the ancestors
17888 if Etype (Typ) /= Typ
17890 -- Protect the frontend against wrong cyclic declarations like:
17892 -- type B is new A with private;
17893 -- type C is new A with private;
17895 -- type B is new C with null record;
17896 -- type C is new B with null record;
17898 and then Etype (Typ) /= Priv_T
17899 and then Etype (Typ) /= Full_T
17901 -- Keep separate the management of private type declarations
17903 if Ekind (Typ) = E_Record_Type_With_Private then
17905 -- Handle the following erroneous case:
17906 -- type Private_Type is tagged private;
17908 -- type Private_Type is new Type_Implementing_Iface;
17910 if Present (Full_View (Typ))
17911 and then Etype (Typ) /= Full_View (Typ)
17913 if Is_Interface (Etype (Typ)) then
17914 Append_Unique_Elmt (Etype (Typ), Ifaces);
17917 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
17920 -- Non-private types
17923 if Is_Interface (Etype (Typ)) then
17924 Append_Unique_Elmt (Etype (Typ), Ifaces);
17927 Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
17931 -- Handle entities in the list of abstract interfaces
17933 if Present (Interfaces (Typ)) then
17934 Iface_Elmt := First_Elmt (Interfaces (Typ));
17935 while Present (Iface_Elmt) loop
17936 Iface := Node (Iface_Elmt);
17938 pragma Assert (Is_Interface (Iface));
17940 if not Contain_Interface (Iface, Ifaces) then
17941 Append_Elmt (Iface, Ifaces);
17942 Collect_Implemented_Interfaces (Iface, Ifaces);
17945 Next_Elmt (Iface_Elmt);
17948 end Collect_Implemented_Interfaces;
17950 -- Start of processing for Process_Full_View
17953 -- First some sanity checks that must be done after semantic
17954 -- decoration of the full view and thus cannot be placed with other
17955 -- similar checks in Find_Type_Name
17957 if not Is_Limited_Type (Priv_T)
17958 and then (Is_Limited_Type (Full_T)
17959 or else Is_Limited_Composite (Full_T))
17961 if In_Instance then
17965 ("completion of nonlimited type cannot be limited", Full_T);
17966 Explain_Limited_Type (Full_T, Full_T);
17969 elsif Is_Abstract_Type (Full_T)
17970 and then not Is_Abstract_Type (Priv_T)
17973 ("completion of nonabstract type cannot be abstract", Full_T);
17975 elsif Is_Tagged_Type (Priv_T)
17976 and then Is_Limited_Type (Priv_T)
17977 and then not Is_Limited_Type (Full_T)
17979 -- If pragma CPP_Class was applied to the private declaration
17980 -- propagate the limitedness to the full-view
17982 if Is_CPP_Class (Priv_T) then
17983 Set_Is_Limited_Record (Full_T);
17985 -- GNAT allow its own definition of Limited_Controlled to disobey
17986 -- this rule in order in ease the implementation. This test is safe
17987 -- because Root_Controlled is defined in a child of System that
17988 -- normal programs are not supposed to use.
17990 elsif Is_RTE (Etype (Full_T), RE_Root_Controlled) then
17991 Set_Is_Limited_Composite (Full_T);
17994 ("completion of limited tagged type must be limited", Full_T);
17997 elsif Is_Generic_Type (Priv_T) then
17998 Error_Msg_N ("generic type cannot have a completion", Full_T);
18001 -- Check that ancestor interfaces of private and full views are
18002 -- consistent. We omit this check for synchronized types because
18003 -- they are performed on the corresponding record type when frozen.
18005 if Ada_Version >= Ada_2005
18006 and then Is_Tagged_Type (Priv_T)
18007 and then Is_Tagged_Type (Full_T)
18008 and then not Is_Concurrent_Type (Full_T)
18012 Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
18013 Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
18016 Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
18017 Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
18019 -- Ada 2005 (AI-251): The partial view shall be a descendant of
18020 -- an interface type if and only if the full type is descendant
18021 -- of the interface type (AARM 7.3 (7.3/2)).
18023 Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
18025 if Present (Iface) then
18027 ("interface & not implemented by full type " &
18028 "(RM-2005 7.3 (7.3/2))", Priv_T, Iface);
18031 Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
18033 if Present (Iface) then
18035 ("interface & not implemented by partial view " &
18036 "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
18041 if Is_Tagged_Type (Priv_T)
18042 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
18043 and then Is_Derived_Type (Full_T)
18045 Priv_Parent := Etype (Priv_T);
18047 -- The full view of a private extension may have been transformed
18048 -- into an unconstrained derived type declaration and a subtype
18049 -- declaration (see build_derived_record_type for details).
18051 if Nkind (N) = N_Subtype_Declaration then
18052 Full_Indic := Subtype_Indication (N);
18053 Full_Parent := Etype (Base_Type (Full_T));
18055 Full_Indic := Subtype_Indication (Type_Definition (N));
18056 Full_Parent := Etype (Full_T);
18059 -- Check that the parent type of the full type is a descendant of
18060 -- the ancestor subtype given in the private extension. If either
18061 -- entity has an Etype equal to Any_Type then we had some previous
18062 -- error situation [7.3(8)].
18064 if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
18067 -- Ada 2005 (AI-251): Interfaces in the full-typ can be given in
18068 -- any order. Therefore we don't have to check that its parent must
18069 -- be a descendant of the parent of the private type declaration.
18071 elsif Is_Interface (Priv_Parent)
18072 and then Is_Interface (Full_Parent)
18076 -- Ada 2005 (AI-251): If the parent of the private type declaration
18077 -- is an interface there is no need to check that it is an ancestor
18078 -- of the associated full type declaration. The required tests for
18079 -- this case are performed by Build_Derived_Record_Type.
18081 elsif not Is_Interface (Base_Type (Priv_Parent))
18082 and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
18085 ("parent of full type must descend from parent"
18086 & " of private extension", Full_Indic);
18088 -- First check a formal restriction, and then proceed with checking
18089 -- Ada rules. Since the formal restriction is not a serious error, we
18090 -- don't prevent further error detection for this check, hence the
18095 -- In formal mode, when completing a private extension the type
18096 -- named in the private part must be exactly the same as that
18097 -- named in the visible part.
18099 if Priv_Parent /= Full_Parent then
18100 Error_Msg_Name_1 := Chars (Priv_Parent);
18101 Check_SPARK_Restriction ("% expected", Full_Indic);
18104 -- Check the rules of 7.3(10): if the private extension inherits
18105 -- known discriminants, then the full type must also inherit those
18106 -- discriminants from the same (ancestor) type, and the parent
18107 -- subtype of the full type must be constrained if and only if
18108 -- the ancestor subtype of the private extension is constrained.
18110 if No (Discriminant_Specifications (Parent (Priv_T)))
18111 and then not Has_Unknown_Discriminants (Priv_T)
18112 and then Has_Discriminants (Base_Type (Priv_Parent))
18115 Priv_Indic : constant Node_Id :=
18116 Subtype_Indication (Parent (Priv_T));
18118 Priv_Constr : constant Boolean :=
18119 Is_Constrained (Priv_Parent)
18121 Nkind (Priv_Indic) = N_Subtype_Indication
18123 Is_Constrained (Entity (Priv_Indic));
18125 Full_Constr : constant Boolean :=
18126 Is_Constrained (Full_Parent)
18128 Nkind (Full_Indic) = N_Subtype_Indication
18130 Is_Constrained (Entity (Full_Indic));
18132 Priv_Discr : Entity_Id;
18133 Full_Discr : Entity_Id;
18136 Priv_Discr := First_Discriminant (Priv_Parent);
18137 Full_Discr := First_Discriminant (Full_Parent);
18138 while Present (Priv_Discr) and then Present (Full_Discr) loop
18139 if Original_Record_Component (Priv_Discr) =
18140 Original_Record_Component (Full_Discr)
18142 Corresponding_Discriminant (Priv_Discr) =
18143 Corresponding_Discriminant (Full_Discr)
18150 Next_Discriminant (Priv_Discr);
18151 Next_Discriminant (Full_Discr);
18154 if Present (Priv_Discr) or else Present (Full_Discr) then
18156 ("full view must inherit discriminants of the parent"
18157 & " type used in the private extension", Full_Indic);
18159 elsif Priv_Constr and then not Full_Constr then
18161 ("parent subtype of full type must be constrained",
18164 elsif Full_Constr and then not Priv_Constr then
18166 ("parent subtype of full type must be unconstrained",
18171 -- Check the rules of 7.3(12): if a partial view has neither
18172 -- known or unknown discriminants, then the full type
18173 -- declaration shall define a definite subtype.
18175 elsif not Has_Unknown_Discriminants (Priv_T)
18176 and then not Has_Discriminants (Priv_T)
18177 and then not Is_Constrained (Full_T)
18180 ("full view must define a constrained type if partial view"
18181 & " has no discriminants", Full_T);
18184 -- ??????? Do we implement the following properly ?????
18185 -- If the ancestor subtype of a private extension has constrained
18186 -- discriminants, then the parent subtype of the full view shall
18187 -- impose a statically matching constraint on those discriminants
18192 -- For untagged types, verify that a type without discriminants
18193 -- is not completed with an unconstrained type.
18195 if not Is_Indefinite_Subtype (Priv_T)
18196 and then Is_Indefinite_Subtype (Full_T)
18198 Error_Msg_N ("full view of type must be definite subtype", Full_T);
18202 -- AI-419: verify that the use of "limited" is consistent
18205 Orig_Decl : constant Node_Id := Original_Node (N);
18208 if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
18209 and then not Limited_Present (Parent (Priv_T))
18210 and then not Synchronized_Present (Parent (Priv_T))
18211 and then Nkind (Orig_Decl) = N_Full_Type_Declaration
18213 (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition
18214 and then Limited_Present (Type_Definition (Orig_Decl))
18217 ("full view of non-limited extension cannot be limited", N);
18221 -- Ada 2005 (AI-443): A synchronized private extension must be
18222 -- completed by a task or protected type.
18224 if Ada_Version >= Ada_2005
18225 and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
18226 and then Synchronized_Present (Parent (Priv_T))
18227 and then not Is_Concurrent_Type (Full_T)
18229 Error_Msg_N ("full view of synchronized extension must " &
18230 "be synchronized type", N);
18233 -- Ada 2005 AI-363: if the full view has discriminants with
18234 -- defaults, it is illegal to declare constrained access subtypes
18235 -- whose designated type is the current type. This allows objects
18236 -- of the type that are declared in the heap to be unconstrained.
18238 if not Has_Unknown_Discriminants (Priv_T)
18239 and then not Has_Discriminants (Priv_T)
18240 and then Has_Discriminants (Full_T)
18242 Present (Discriminant_Default_Value (First_Discriminant (Full_T)))
18244 Set_Has_Constrained_Partial_View (Full_T);
18245 Set_Has_Constrained_Partial_View (Priv_T);
18248 -- Create a full declaration for all its subtypes recorded in
18249 -- Private_Dependents and swap them similarly to the base type. These
18250 -- are subtypes that have been define before the full declaration of
18251 -- the private type. We also swap the entry in Private_Dependents list
18252 -- so we can properly restore the private view on exit from the scope.
18255 Priv_Elmt : Elmt_Id;
18260 Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
18261 while Present (Priv_Elmt) loop
18262 Priv := Node (Priv_Elmt);
18264 if Ekind_In (Priv, E_Private_Subtype,
18265 E_Limited_Private_Subtype,
18266 E_Record_Subtype_With_Private)
18268 Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
18269 Set_Is_Itype (Full);
18270 Set_Parent (Full, Parent (Priv));
18271 Set_Associated_Node_For_Itype (Full, N);
18273 -- Now we need to complete the private subtype, but since the
18274 -- base type has already been swapped, we must also swap the
18275 -- subtypes (and thus, reverse the arguments in the call to
18276 -- Complete_Private_Subtype).
18278 Copy_And_Swap (Priv, Full);
18279 Complete_Private_Subtype (Full, Priv, Full_T, N);
18280 Replace_Elmt (Priv_Elmt, Full);
18283 Next_Elmt (Priv_Elmt);
18287 -- If the private view was tagged, copy the new primitive operations
18288 -- from the private view to the full view.
18290 if Is_Tagged_Type (Full_T) then
18292 Disp_Typ : Entity_Id;
18293 Full_List : Elist_Id;
18295 Prim_Elmt : Elmt_Id;
18296 Priv_List : Elist_Id;
18300 L : Elist_Id) return Boolean;
18301 -- Determine whether list L contains element E
18309 L : Elist_Id) return Boolean
18311 List_Elmt : Elmt_Id;
18314 List_Elmt := First_Elmt (L);
18315 while Present (List_Elmt) loop
18316 if Node (List_Elmt) = E then
18320 Next_Elmt (List_Elmt);
18326 -- Start of processing
18329 if Is_Tagged_Type (Priv_T) then
18330 Priv_List := Primitive_Operations (Priv_T);
18331 Prim_Elmt := First_Elmt (Priv_List);
18333 -- In the case of a concurrent type completing a private tagged
18334 -- type, primitives may have been declared in between the two
18335 -- views. These subprograms need to be wrapped the same way
18336 -- entries and protected procedures are handled because they
18337 -- cannot be directly shared by the two views.
18339 if Is_Concurrent_Type (Full_T) then
18341 Conc_Typ : constant Entity_Id :=
18342 Corresponding_Record_Type (Full_T);
18343 Curr_Nod : Node_Id := Parent (Conc_Typ);
18344 Wrap_Spec : Node_Id;
18347 while Present (Prim_Elmt) loop
18348 Prim := Node (Prim_Elmt);
18350 if Comes_From_Source (Prim)
18351 and then not Is_Abstract_Subprogram (Prim)
18354 Make_Subprogram_Declaration (Sloc (Prim),
18358 Obj_Typ => Conc_Typ,
18360 Parameter_Specifications (
18363 Insert_After (Curr_Nod, Wrap_Spec);
18364 Curr_Nod := Wrap_Spec;
18366 Analyze (Wrap_Spec);
18369 Next_Elmt (Prim_Elmt);
18375 -- For non-concurrent types, transfer explicit primitives, but
18376 -- omit those inherited from the parent of the private view
18377 -- since they will be re-inherited later on.
18380 Full_List := Primitive_Operations (Full_T);
18382 while Present (Prim_Elmt) loop
18383 Prim := Node (Prim_Elmt);
18385 if Comes_From_Source (Prim)
18386 and then not Contains (Prim, Full_List)
18388 Append_Elmt (Prim, Full_List);
18391 Next_Elmt (Prim_Elmt);
18395 -- Untagged private view
18398 Full_List := Primitive_Operations (Full_T);
18400 -- In this case the partial view is untagged, so here we locate
18401 -- all of the earlier primitives that need to be treated as
18402 -- dispatching (those that appear between the two views). Note
18403 -- that these additional operations must all be new operations
18404 -- (any earlier operations that override inherited operations
18405 -- of the full view will already have been inserted in the
18406 -- primitives list, marked by Check_Operation_From_Private_View
18407 -- as dispatching. Note that implicit "/=" operators are
18408 -- excluded from being added to the primitives list since they
18409 -- shouldn't be treated as dispatching (tagged "/=" is handled
18412 Prim := Next_Entity (Full_T);
18413 while Present (Prim) and then Prim /= Priv_T loop
18414 if Ekind_In (Prim, E_Procedure, E_Function) then
18415 Disp_Typ := Find_Dispatching_Type (Prim);
18417 if Disp_Typ = Full_T
18418 and then (Chars (Prim) /= Name_Op_Ne
18419 or else Comes_From_Source (Prim))
18421 Check_Controlling_Formals (Full_T, Prim);
18423 if not Is_Dispatching_Operation (Prim) then
18424 Append_Elmt (Prim, Full_List);
18425 Set_Is_Dispatching_Operation (Prim, True);
18426 Set_DT_Position (Prim, No_Uint);
18429 elsif Is_Dispatching_Operation (Prim)
18430 and then Disp_Typ /= Full_T
18433 -- Verify that it is not otherwise controlled by a
18434 -- formal or a return value of type T.
18436 Check_Controlling_Formals (Disp_Typ, Prim);
18440 Next_Entity (Prim);
18444 -- For the tagged case, the two views can share the same primitive
18445 -- operations list and the same class-wide type. Update attributes
18446 -- of the class-wide type which depend on the full declaration.
18448 if Is_Tagged_Type (Priv_T) then
18449 Set_Direct_Primitive_Operations (Priv_T, Full_List);
18450 Set_Class_Wide_Type
18451 (Base_Type (Full_T), Class_Wide_Type (Priv_T));
18453 Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
18458 -- Ada 2005 AI 161: Check preelaboratable initialization consistency
18460 if Known_To_Have_Preelab_Init (Priv_T) then
18462 -- Case where there is a pragma Preelaborable_Initialization. We
18463 -- always allow this in predefined units, which is a bit of a kludge,
18464 -- but it means we don't have to struggle to meet the requirements in
18465 -- the RM for having Preelaborable Initialization. Otherwise we
18466 -- require that the type meets the RM rules. But we can't check that
18467 -- yet, because of the rule about overriding Initialize, so we simply
18468 -- set a flag that will be checked at freeze time.
18470 if not In_Predefined_Unit (Full_T) then
18471 Set_Must_Have_Preelab_Init (Full_T);
18475 -- If pragma CPP_Class was applied to the private type declaration,
18476 -- propagate it now to the full type declaration.
18478 if Is_CPP_Class (Priv_T) then
18479 Set_Is_CPP_Class (Full_T);
18480 Set_Convention (Full_T, Convention_CPP);
18482 -- Check that components of imported CPP types do not have default
18485 Check_CPP_Type_Has_No_Defaults (Full_T);
18488 -- If the private view has user specified stream attributes, then so has
18491 -- Why the test, how could these flags be already set in Full_T ???
18493 if Has_Specified_Stream_Read (Priv_T) then
18494 Set_Has_Specified_Stream_Read (Full_T);
18497 if Has_Specified_Stream_Write (Priv_T) then
18498 Set_Has_Specified_Stream_Write (Full_T);
18501 if Has_Specified_Stream_Input (Priv_T) then
18502 Set_Has_Specified_Stream_Input (Full_T);
18505 if Has_Specified_Stream_Output (Priv_T) then
18506 Set_Has_Specified_Stream_Output (Full_T);
18509 -- Propagate invariants to full type
18511 if Has_Invariants (Priv_T) then
18512 Set_Has_Invariants (Full_T);
18513 Set_Invariant_Procedure (Full_T, Invariant_Procedure (Priv_T));
18516 if Has_Inheritable_Invariants (Priv_T) then
18517 Set_Has_Inheritable_Invariants (Full_T);
18520 -- Propagate predicates to full type
18522 if Has_Predicates (Priv_T) then
18523 Set_Predicate_Function (Priv_T, Predicate_Function (Full_T));
18524 Set_Has_Predicates (Full_T);
18526 end Process_Full_View;
18528 -----------------------------------
18529 -- Process_Incomplete_Dependents --
18530 -----------------------------------
18532 procedure Process_Incomplete_Dependents
18534 Full_T : Entity_Id;
18537 Inc_Elmt : Elmt_Id;
18538 Priv_Dep : Entity_Id;
18539 New_Subt : Entity_Id;
18541 Disc_Constraint : Elist_Id;
18544 if No (Private_Dependents (Inc_T)) then
18548 -- Itypes that may be generated by the completion of an incomplete
18549 -- subtype are not used by the back-end and not attached to the tree.
18550 -- They are created only for constraint-checking purposes.
18552 Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
18553 while Present (Inc_Elmt) loop
18554 Priv_Dep := Node (Inc_Elmt);
18556 if Ekind (Priv_Dep) = E_Subprogram_Type then
18558 -- An Access_To_Subprogram type may have a return type or a
18559 -- parameter type that is incomplete. Replace with the full view.
18561 if Etype (Priv_Dep) = Inc_T then
18562 Set_Etype (Priv_Dep, Full_T);
18566 Formal : Entity_Id;
18569 Formal := First_Formal (Priv_Dep);
18570 while Present (Formal) loop
18571 if Etype (Formal) = Inc_T then
18572 Set_Etype (Formal, Full_T);
18575 Next_Formal (Formal);
18579 elsif Is_Overloadable (Priv_Dep) then
18581 -- If a subprogram in the incomplete dependents list is primitive
18582 -- for a tagged full type then mark it as a dispatching operation,
18583 -- check whether it overrides an inherited subprogram, and check
18584 -- restrictions on its controlling formals. Note that a protected
18585 -- operation is never dispatching: only its wrapper operation
18586 -- (which has convention Ada) is.
18588 if Is_Tagged_Type (Full_T)
18589 and then Is_Primitive (Priv_Dep)
18590 and then Convention (Priv_Dep) /= Convention_Protected
18592 Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
18593 Set_Is_Dispatching_Operation (Priv_Dep);
18594 Check_Controlling_Formals (Full_T, Priv_Dep);
18597 elsif Ekind (Priv_Dep) = E_Subprogram_Body then
18599 -- Can happen during processing of a body before the completion
18600 -- of a TA type. Ignore, because spec is also on dependent list.
18604 -- Ada 2005 (AI-412): Transform a regular incomplete subtype into a
18605 -- corresponding subtype of the full view.
18607 elsif Ekind (Priv_Dep) = E_Incomplete_Subtype then
18608 Set_Subtype_Indication
18609 (Parent (Priv_Dep), New_Reference_To (Full_T, Sloc (Priv_Dep)));
18610 Set_Etype (Priv_Dep, Full_T);
18611 Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T)));
18612 Set_Analyzed (Parent (Priv_Dep), False);
18614 -- Reanalyze the declaration, suppressing the call to
18615 -- Enter_Name to avoid duplicate names.
18617 Analyze_Subtype_Declaration
18618 (N => Parent (Priv_Dep),
18621 -- Dependent is a subtype
18624 -- We build a new subtype indication using the full view of the
18625 -- incomplete parent. The discriminant constraints have been
18626 -- elaborated already at the point of the subtype declaration.
18628 New_Subt := Create_Itype (E_Void, N);
18630 if Has_Discriminants (Full_T) then
18631 Disc_Constraint := Discriminant_Constraint (Priv_Dep);
18633 Disc_Constraint := No_Elist;
18636 Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
18637 Set_Full_View (Priv_Dep, New_Subt);
18640 Next_Elmt (Inc_Elmt);
18642 end Process_Incomplete_Dependents;
18644 --------------------------------
18645 -- Process_Range_Expr_In_Decl --
18646 --------------------------------
18648 procedure Process_Range_Expr_In_Decl
18651 Check_List : List_Id := Empty_List;
18652 R_Check_Off : Boolean := False;
18653 In_Iter_Schm : Boolean := False)
18656 R_Checks : Check_Result;
18657 Insert_Node : Node_Id;
18658 Def_Id : Entity_Id;
18661 Analyze_And_Resolve (R, Base_Type (T));
18663 if Nkind (R) = N_Range then
18665 -- In SPARK, all ranges should be static, with the exception of the
18666 -- discrete type definition of a loop parameter specification.
18668 if not In_Iter_Schm
18669 and then not Is_Static_Range (R)
18671 Check_SPARK_Restriction ("range should be static", R);
18674 Lo := Low_Bound (R);
18675 Hi := High_Bound (R);
18677 -- We need to ensure validity of the bounds here, because if we
18678 -- go ahead and do the expansion, then the expanded code will get
18679 -- analyzed with range checks suppressed and we miss the check.
18681 Validity_Check_Range (R);
18683 -- If there were errors in the declaration, try and patch up some
18684 -- common mistakes in the bounds. The cases handled are literals
18685 -- which are Integer where the expected type is Real and vice versa.
18686 -- These corrections allow the compilation process to proceed further
18687 -- along since some basic assumptions of the format of the bounds
18690 if Etype (R) = Any_Type then
18692 if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
18694 Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
18696 elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
18698 Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
18700 elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
18702 Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
18704 elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
18706 Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
18713 -- If the bounds of the range have been mistakenly given as string
18714 -- literals (perhaps in place of character literals), then an error
18715 -- has already been reported, but we rewrite the string literal as a
18716 -- bound of the range's type to avoid blowups in later processing
18717 -- that looks at static values.
18719 if Nkind (Lo) = N_String_Literal then
18721 Make_Attribute_Reference (Sloc (Lo),
18722 Attribute_Name => Name_First,
18723 Prefix => New_Reference_To (T, Sloc (Lo))));
18724 Analyze_And_Resolve (Lo);
18727 if Nkind (Hi) = N_String_Literal then
18729 Make_Attribute_Reference (Sloc (Hi),
18730 Attribute_Name => Name_First,
18731 Prefix => New_Reference_To (T, Sloc (Hi))));
18732 Analyze_And_Resolve (Hi);
18735 -- If bounds aren't scalar at this point then exit, avoiding
18736 -- problems with further processing of the range in this procedure.
18738 if not Is_Scalar_Type (Etype (Lo)) then
18742 -- Resolve (actually Sem_Eval) has checked that the bounds are in
18743 -- then range of the base type. Here we check whether the bounds
18744 -- are in the range of the subtype itself. Note that if the bounds
18745 -- represent the null range the Constraint_Error exception should
18748 -- ??? The following code should be cleaned up as follows
18750 -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
18751 -- is done in the call to Range_Check (R, T); below
18753 -- 2. The use of R_Check_Off should be investigated and possibly
18754 -- removed, this would clean up things a bit.
18756 if Is_Null_Range (Lo, Hi) then
18760 -- Capture values of bounds and generate temporaries for them
18761 -- if needed, before applying checks, since checks may cause
18762 -- duplication of the expression without forcing evaluation.
18764 -- The forced evaluation removes side effects from expressions,
18765 -- which should occur also in SPARK mode. Otherwise, we end up
18766 -- with unexpected insertions of actions at places where this is
18767 -- not supposed to occur, e.g. on default parameters of a call.
18769 if Expander_Active then
18770 Force_Evaluation (Lo);
18771 Force_Evaluation (Hi);
18774 -- We use a flag here instead of suppressing checks on the
18775 -- type because the type we check against isn't necessarily
18776 -- the place where we put the check.
18778 if not R_Check_Off then
18779 R_Checks := Get_Range_Checks (R, T);
18781 -- Look up tree to find an appropriate insertion point. We
18782 -- can't just use insert_actions because later processing
18783 -- depends on the insertion node. Prior to Ada 2012 the
18784 -- insertion point could only be a declaration or a loop, but
18785 -- quantified expressions can appear within any context in an
18786 -- expression, and the insertion point can be any statement,
18787 -- pragma, or declaration.
18789 Insert_Node := Parent (R);
18790 while Present (Insert_Node) loop
18792 Nkind (Insert_Node) in N_Declaration
18795 (Insert_Node, N_Component_Declaration,
18796 N_Loop_Parameter_Specification,
18797 N_Function_Specification,
18798 N_Procedure_Specification);
18800 exit when Nkind (Insert_Node) in N_Later_Decl_Item
18801 or else Nkind (Insert_Node) in
18802 N_Statement_Other_Than_Procedure_Call
18803 or else Nkind_In (Insert_Node, N_Procedure_Call_Statement,
18806 Insert_Node := Parent (Insert_Node);
18809 -- Why would Type_Decl not be present??? Without this test,
18810 -- short regression tests fail.
18812 if Present (Insert_Node) then
18814 -- Case of loop statement. Verify that the range is part
18815 -- of the subtype indication of the iteration scheme.
18817 if Nkind (Insert_Node) = N_Loop_Statement then
18822 Indic := Parent (R);
18823 while Present (Indic)
18824 and then Nkind (Indic) /= N_Subtype_Indication
18826 Indic := Parent (Indic);
18829 if Present (Indic) then
18830 Def_Id := Etype (Subtype_Mark (Indic));
18832 Insert_Range_Checks
18836 Sloc (Insert_Node),
18838 Do_Before => True);
18842 -- Insertion before a declaration. If the declaration
18843 -- includes discriminants, the list of applicable checks
18844 -- is given by the caller.
18846 elsif Nkind (Insert_Node) in N_Declaration then
18847 Def_Id := Defining_Identifier (Insert_Node);
18849 if (Ekind (Def_Id) = E_Record_Type
18850 and then Depends_On_Discriminant (R))
18852 (Ekind (Def_Id) = E_Protected_Type
18853 and then Has_Discriminants (Def_Id))
18855 Append_Range_Checks
18857 Check_List, Def_Id, Sloc (Insert_Node), R);
18860 Insert_Range_Checks
18862 Insert_Node, Def_Id, Sloc (Insert_Node), R);
18866 -- Insertion before a statement. Range appears in the
18867 -- context of a quantified expression. Insertion will
18868 -- take place when expression is expanded.
18877 -- Case of other than an explicit N_Range node
18879 -- The forced evaluation removes side effects from expressions, which
18880 -- should occur also in SPARK mode. Otherwise, we end up with unexpected
18881 -- insertions of actions at places where this is not supposed to occur,
18882 -- e.g. on default parameters of a call.
18884 elsif Expander_Active then
18885 Get_Index_Bounds (R, Lo, Hi);
18886 Force_Evaluation (Lo);
18887 Force_Evaluation (Hi);
18889 end Process_Range_Expr_In_Decl;
18891 --------------------------------------
18892 -- Process_Real_Range_Specification --
18893 --------------------------------------
18895 procedure Process_Real_Range_Specification (Def : Node_Id) is
18896 Spec : constant Node_Id := Real_Range_Specification (Def);
18899 Err : Boolean := False;
18901 procedure Analyze_Bound (N : Node_Id);
18902 -- Analyze and check one bound
18904 -------------------
18905 -- Analyze_Bound --
18906 -------------------
18908 procedure Analyze_Bound (N : Node_Id) is
18910 Analyze_And_Resolve (N, Any_Real);
18912 if not Is_OK_Static_Expression (N) then
18913 Flag_Non_Static_Expr
18914 ("bound in real type definition is not static!", N);
18919 -- Start of processing for Process_Real_Range_Specification
18922 if Present (Spec) then
18923 Lo := Low_Bound (Spec);
18924 Hi := High_Bound (Spec);
18925 Analyze_Bound (Lo);
18926 Analyze_Bound (Hi);
18928 -- If error, clear away junk range specification
18931 Set_Real_Range_Specification (Def, Empty);
18934 end Process_Real_Range_Specification;
18936 ---------------------
18937 -- Process_Subtype --
18938 ---------------------
18940 function Process_Subtype
18942 Related_Nod : Node_Id;
18943 Related_Id : Entity_Id := Empty;
18944 Suffix : Character := ' ') return Entity_Id
18947 Def_Id : Entity_Id;
18948 Error_Node : Node_Id;
18949 Full_View_Id : Entity_Id;
18950 Subtype_Mark_Id : Entity_Id;
18952 May_Have_Null_Exclusion : Boolean;
18954 procedure Check_Incomplete (T : Entity_Id);
18955 -- Called to verify that an incomplete type is not used prematurely
18957 ----------------------
18958 -- Check_Incomplete --
18959 ----------------------
18961 procedure Check_Incomplete (T : Entity_Id) is
18963 -- Ada 2005 (AI-412): Incomplete subtypes are legal
18965 if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type
18967 not (Ada_Version >= Ada_2005
18969 (Nkind (Parent (T)) = N_Subtype_Declaration
18971 (Nkind (Parent (T)) = N_Subtype_Indication
18972 and then Nkind (Parent (Parent (T))) =
18973 N_Subtype_Declaration)))
18975 Error_Msg_N ("invalid use of type before its full declaration", T);
18977 end Check_Incomplete;
18979 -- Start of processing for Process_Subtype
18982 -- Case of no constraints present
18984 if Nkind (S) /= N_Subtype_Indication then
18986 Check_Incomplete (S);
18989 -- Ada 2005 (AI-231): Static check
18991 if Ada_Version >= Ada_2005
18992 and then Present (P)
18993 and then Null_Exclusion_Present (P)
18994 and then Nkind (P) /= N_Access_To_Object_Definition
18995 and then not Is_Access_Type (Entity (S))
18997 Error_Msg_N ("`NOT NULL` only allowed for an access type", S);
19000 -- The following is ugly, can't we have a range or even a flag???
19002 May_Have_Null_Exclusion :=
19003 Nkind_In (P, N_Access_Definition,
19004 N_Access_Function_Definition,
19005 N_Access_Procedure_Definition,
19006 N_Access_To_Object_Definition,
19008 N_Component_Definition)
19010 Nkind_In (P, N_Derived_Type_Definition,
19011 N_Discriminant_Specification,
19012 N_Formal_Object_Declaration,
19013 N_Object_Declaration,
19014 N_Object_Renaming_Declaration,
19015 N_Parameter_Specification,
19016 N_Subtype_Declaration);
19018 -- Create an Itype that is a duplicate of Entity (S) but with the
19019 -- null-exclusion attribute.
19021 if May_Have_Null_Exclusion
19022 and then Is_Access_Type (Entity (S))
19023 and then Null_Exclusion_Present (P)
19025 -- No need to check the case of an access to object definition.
19026 -- It is correct to define double not-null pointers.
19029 -- type Not_Null_Int_Ptr is not null access Integer;
19030 -- type Acc is not null access Not_Null_Int_Ptr;
19032 and then Nkind (P) /= N_Access_To_Object_Definition
19034 if Can_Never_Be_Null (Entity (S)) then
19035 case Nkind (Related_Nod) is
19036 when N_Full_Type_Declaration =>
19037 if Nkind (Type_Definition (Related_Nod))
19038 in N_Array_Type_Definition
19042 (Component_Definition
19043 (Type_Definition (Related_Nod)));
19046 Subtype_Indication (Type_Definition (Related_Nod));
19049 when N_Subtype_Declaration =>
19050 Error_Node := Subtype_Indication (Related_Nod);
19052 when N_Object_Declaration =>
19053 Error_Node := Object_Definition (Related_Nod);
19055 when N_Component_Declaration =>
19057 Subtype_Indication (Component_Definition (Related_Nod));
19059 when N_Allocator =>
19060 Error_Node := Expression (Related_Nod);
19063 pragma Assert (False);
19064 Error_Node := Related_Nod;
19068 ("`NOT NULL` not allowed (& already excludes null)",
19074 Create_Null_Excluding_Itype
19076 Related_Nod => P));
19077 Set_Entity (S, Etype (S));
19082 -- Case of constraint present, so that we have an N_Subtype_Indication
19083 -- node (this node is created only if constraints are present).
19086 Find_Type (Subtype_Mark (S));
19088 if Nkind (Parent (S)) /= N_Access_To_Object_Definition
19090 (Nkind (Parent (S)) = N_Subtype_Declaration
19091 and then Is_Itype (Defining_Identifier (Parent (S))))
19093 Check_Incomplete (Subtype_Mark (S));
19097 Subtype_Mark_Id := Entity (Subtype_Mark (S));
19099 -- Explicit subtype declaration case
19101 if Nkind (P) = N_Subtype_Declaration then
19102 Def_Id := Defining_Identifier (P);
19104 -- Explicit derived type definition case
19106 elsif Nkind (P) = N_Derived_Type_Definition then
19107 Def_Id := Defining_Identifier (Parent (P));
19109 -- Implicit case, the Def_Id must be created as an implicit type.
19110 -- The one exception arises in the case of concurrent types, array
19111 -- and access types, where other subsidiary implicit types may be
19112 -- created and must appear before the main implicit type. In these
19113 -- cases we leave Def_Id set to Empty as a signal that Create_Itype
19114 -- has not yet been called to create Def_Id.
19117 if Is_Array_Type (Subtype_Mark_Id)
19118 or else Is_Concurrent_Type (Subtype_Mark_Id)
19119 or else Is_Access_Type (Subtype_Mark_Id)
19123 -- For the other cases, we create a new unattached Itype,
19124 -- and set the indication to ensure it gets attached later.
19128 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
19132 -- If the kind of constraint is invalid for this kind of type,
19133 -- then give an error, and then pretend no constraint was given.
19135 if not Is_Valid_Constraint_Kind
19136 (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
19139 ("incorrect constraint for this kind of type", Constraint (S));
19141 Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
19143 -- Set Ekind of orphan itype, to prevent cascaded errors
19145 if Present (Def_Id) then
19146 Set_Ekind (Def_Id, Ekind (Any_Type));
19149 -- Make recursive call, having got rid of the bogus constraint
19151 return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
19154 -- Remaining processing depends on type. Select on Base_Type kind to
19155 -- ensure getting to the concrete type kind in the case of a private
19156 -- subtype (needed when only doing semantic analysis).
19158 case Ekind (Base_Type (Subtype_Mark_Id)) is
19159 when Access_Kind =>
19161 -- If this is a constraint on a class-wide type, discard it.
19162 -- There is currently no way to express a partial discriminant
19163 -- constraint on a type with unknown discriminants. This is
19164 -- a pathology that the ACATS wisely decides not to test.
19166 if Is_Class_Wide_Type (Designated_Type (Subtype_Mark_Id)) then
19167 if Comes_From_Source (S) then
19169 ("constraint on class-wide type ignored?",
19173 if Nkind (P) = N_Subtype_Declaration then
19174 Set_Subtype_Indication (P,
19175 New_Occurrence_Of (Subtype_Mark_Id, Sloc (S)));
19178 return Subtype_Mark_Id;
19181 Constrain_Access (Def_Id, S, Related_Nod);
19184 and then Is_Itype (Designated_Type (Def_Id))
19185 and then Nkind (Related_Nod) = N_Subtype_Declaration
19186 and then not Is_Incomplete_Type (Designated_Type (Def_Id))
19188 Build_Itype_Reference
19189 (Designated_Type (Def_Id), Related_Nod);
19193 Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
19195 when Decimal_Fixed_Point_Kind =>
19196 Constrain_Decimal (Def_Id, S);
19198 when Enumeration_Kind =>
19199 Constrain_Enumeration (Def_Id, S);
19201 when Ordinary_Fixed_Point_Kind =>
19202 Constrain_Ordinary_Fixed (Def_Id, S);
19205 Constrain_Float (Def_Id, S);
19207 when Integer_Kind =>
19208 Constrain_Integer (Def_Id, S);
19210 when E_Record_Type |
19213 E_Incomplete_Type =>
19214 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
19216 if Ekind (Def_Id) = E_Incomplete_Type then
19217 Set_Private_Dependents (Def_Id, New_Elmt_List);
19220 when Private_Kind =>
19221 Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
19222 Set_Private_Dependents (Def_Id, New_Elmt_List);
19224 -- In case of an invalid constraint prevent further processing
19225 -- since the type constructed is missing expected fields.
19227 if Etype (Def_Id) = Any_Type then
19231 -- If the full view is that of a task with discriminants,
19232 -- we must constrain both the concurrent type and its
19233 -- corresponding record type. Otherwise we will just propagate
19234 -- the constraint to the full view, if available.
19236 if Present (Full_View (Subtype_Mark_Id))
19237 and then Has_Discriminants (Subtype_Mark_Id)
19238 and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
19241 Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
19243 Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
19244 Constrain_Concurrent (Full_View_Id, S,
19245 Related_Nod, Related_Id, Suffix);
19246 Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
19247 Set_Full_View (Def_Id, Full_View_Id);
19249 -- Introduce an explicit reference to the private subtype,
19250 -- to prevent scope anomalies in gigi if first use appears
19251 -- in a nested context, e.g. a later function body.
19252 -- Should this be generated in other contexts than a full
19253 -- type declaration?
19255 if Is_Itype (Def_Id)
19257 Nkind (Parent (P)) = N_Full_Type_Declaration
19259 Build_Itype_Reference (Def_Id, Parent (P));
19263 Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
19266 when Concurrent_Kind =>
19267 Constrain_Concurrent (Def_Id, S,
19268 Related_Nod, Related_Id, Suffix);
19271 Error_Msg_N ("invalid subtype mark in subtype indication", S);
19274 -- Size and Convention are always inherited from the base type
19276 Set_Size_Info (Def_Id, (Subtype_Mark_Id));
19277 Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
19281 end Process_Subtype;
19283 ---------------------------------------
19284 -- Check_Anonymous_Access_Components --
19285 ---------------------------------------
19287 procedure Check_Anonymous_Access_Components
19288 (Typ_Decl : Node_Id;
19291 Comp_List : Node_Id)
19293 Loc : constant Source_Ptr := Sloc (Typ_Decl);
19294 Anon_Access : Entity_Id;
19297 Comp_Def : Node_Id;
19299 Type_Def : Node_Id;
19301 procedure Build_Incomplete_Type_Declaration;
19302 -- If the record type contains components that include an access to the
19303 -- current record, then create an incomplete type declaration for the
19304 -- record, to be used as the designated type of the anonymous access.
19305 -- This is done only once, and only if there is no previous partial
19306 -- view of the type.
19308 function Designates_T (Subt : Node_Id) return Boolean;
19309 -- Check whether a node designates the enclosing record type, or 'Class
19312 function Mentions_T (Acc_Def : Node_Id) return Boolean;
19313 -- Check whether an access definition includes a reference to
19314 -- the enclosing record type. The reference can be a subtype mark
19315 -- in the access definition itself, a 'Class attribute reference, or
19316 -- recursively a reference appearing in a parameter specification
19317 -- or result definition of an access_to_subprogram definition.
19319 --------------------------------------
19320 -- Build_Incomplete_Type_Declaration --
19321 --------------------------------------
19323 procedure Build_Incomplete_Type_Declaration is
19328 -- Is_Tagged indicates whether the type is tagged. It is tagged if
19329 -- it's "is new ... with record" or else "is tagged record ...".
19331 Is_Tagged : constant Boolean :=
19332 (Nkind (Type_Definition (Typ_Decl)) = N_Derived_Type_Definition
19335 (Record_Extension_Part (Type_Definition (Typ_Decl))))
19337 (Nkind (Type_Definition (Typ_Decl)) = N_Record_Definition
19338 and then Tagged_Present (Type_Definition (Typ_Decl)));
19341 -- If there is a previous partial view, no need to create a new one
19342 -- If the partial view, given by Prev, is incomplete, If Prev is
19343 -- a private declaration, full declaration is flagged accordingly.
19345 if Prev /= Typ then
19347 Make_Class_Wide_Type (Prev);
19348 Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev));
19349 Set_Etype (Class_Wide_Type (Typ), Typ);
19354 elsif Has_Private_Declaration (Typ) then
19356 -- If we refer to T'Class inside T, and T is the completion of a
19357 -- private type, then we need to make sure the class-wide type
19361 Make_Class_Wide_Type (Typ);
19366 -- If there was a previous anonymous access type, the incomplete
19367 -- type declaration will have been created already.
19369 elsif Present (Current_Entity (Typ))
19370 and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type
19371 and then Full_View (Current_Entity (Typ)) = Typ
19374 and then Comes_From_Source (Current_Entity (Typ))
19375 and then not Is_Tagged_Type (Current_Entity (Typ))
19377 Make_Class_Wide_Type (Typ);
19379 ("incomplete view of tagged type should be declared tagged??",
19380 Parent (Current_Entity (Typ)));
19385 Inc_T := Make_Defining_Identifier (Loc, Chars (Typ));
19386 Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
19388 -- Type has already been inserted into the current scope. Remove
19389 -- it, and add incomplete declaration for type, so that subsequent
19390 -- anonymous access types can use it. The entity is unchained from
19391 -- the homonym list and from immediate visibility. After analysis,
19392 -- the entity in the incomplete declaration becomes immediately
19393 -- visible in the record declaration that follows.
19395 H := Current_Entity (Typ);
19398 Set_Name_Entity_Id (Chars (Typ), Homonym (Typ));
19401 and then Homonym (H) /= Typ
19403 H := Homonym (Typ);
19406 Set_Homonym (H, Homonym (Typ));
19409 Insert_Before (Typ_Decl, Decl);
19411 Set_Full_View (Inc_T, Typ);
19415 -- Create a common class-wide type for both views, and set the
19416 -- Etype of the class-wide type to the full view.
19418 Make_Class_Wide_Type (Inc_T);
19419 Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T));
19420 Set_Etype (Class_Wide_Type (Typ), Typ);
19423 end Build_Incomplete_Type_Declaration;
19429 function Designates_T (Subt : Node_Id) return Boolean is
19430 Type_Id : constant Name_Id := Chars (Typ);
19432 function Names_T (Nam : Node_Id) return Boolean;
19433 -- The record type has not been introduced in the current scope
19434 -- yet, so we must examine the name of the type itself, either
19435 -- an identifier T, or an expanded name of the form P.T, where
19436 -- P denotes the current scope.
19442 function Names_T (Nam : Node_Id) return Boolean is
19444 if Nkind (Nam) = N_Identifier then
19445 return Chars (Nam) = Type_Id;
19447 elsif Nkind (Nam) = N_Selected_Component then
19448 if Chars (Selector_Name (Nam)) = Type_Id then
19449 if Nkind (Prefix (Nam)) = N_Identifier then
19450 return Chars (Prefix (Nam)) = Chars (Current_Scope);
19452 elsif Nkind (Prefix (Nam)) = N_Selected_Component then
19453 return Chars (Selector_Name (Prefix (Nam))) =
19454 Chars (Current_Scope);
19468 -- Start of processing for Designates_T
19471 if Nkind (Subt) = N_Identifier then
19472 return Chars (Subt) = Type_Id;
19474 -- Reference can be through an expanded name which has not been
19475 -- analyzed yet, and which designates enclosing scopes.
19477 elsif Nkind (Subt) = N_Selected_Component then
19478 if Names_T (Subt) then
19481 -- Otherwise it must denote an entity that is already visible.
19482 -- The access definition may name a subtype of the enclosing
19483 -- type, if there is a previous incomplete declaration for it.
19486 Find_Selected_Component (Subt);
19488 Is_Entity_Name (Subt)
19489 and then Scope (Entity (Subt)) = Current_Scope
19491 (Chars (Base_Type (Entity (Subt))) = Type_Id
19493 (Is_Class_Wide_Type (Entity (Subt))
19495 Chars (Etype (Base_Type (Entity (Subt)))) =
19499 -- A reference to the current type may appear as the prefix of
19500 -- a 'Class attribute.
19502 elsif Nkind (Subt) = N_Attribute_Reference
19503 and then Attribute_Name (Subt) = Name_Class
19505 return Names_T (Prefix (Subt));
19516 function Mentions_T (Acc_Def : Node_Id) return Boolean is
19517 Param_Spec : Node_Id;
19519 Acc_Subprg : constant Node_Id :=
19520 Access_To_Subprogram_Definition (Acc_Def);
19523 if No (Acc_Subprg) then
19524 return Designates_T (Subtype_Mark (Acc_Def));
19527 -- Component is an access_to_subprogram: examine its formals,
19528 -- and result definition in the case of an access_to_function.
19530 Param_Spec := First (Parameter_Specifications (Acc_Subprg));
19531 while Present (Param_Spec) loop
19532 if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition
19533 and then Mentions_T (Parameter_Type (Param_Spec))
19537 elsif Designates_T (Parameter_Type (Param_Spec)) then
19544 if Nkind (Acc_Subprg) = N_Access_Function_Definition then
19545 if Nkind (Result_Definition (Acc_Subprg)) =
19546 N_Access_Definition
19548 return Mentions_T (Result_Definition (Acc_Subprg));
19550 return Designates_T (Result_Definition (Acc_Subprg));
19557 -- Start of processing for Check_Anonymous_Access_Components
19560 if No (Comp_List) then
19564 Comp := First (Component_Items (Comp_List));
19565 while Present (Comp) loop
19566 if Nkind (Comp) = N_Component_Declaration
19568 (Access_Definition (Component_Definition (Comp)))
19570 Mentions_T (Access_Definition (Component_Definition (Comp)))
19572 Comp_Def := Component_Definition (Comp);
19574 Access_To_Subprogram_Definition
19575 (Access_Definition (Comp_Def));
19577 Build_Incomplete_Type_Declaration;
19578 Anon_Access := Make_Temporary (Loc, 'S');
19580 -- Create a declaration for the anonymous access type: either
19581 -- an access_to_object or an access_to_subprogram.
19583 if Present (Acc_Def) then
19584 if Nkind (Acc_Def) = N_Access_Function_Definition then
19586 Make_Access_Function_Definition (Loc,
19587 Parameter_Specifications =>
19588 Parameter_Specifications (Acc_Def),
19589 Result_Definition => Result_Definition (Acc_Def));
19592 Make_Access_Procedure_Definition (Loc,
19593 Parameter_Specifications =>
19594 Parameter_Specifications (Acc_Def));
19599 Make_Access_To_Object_Definition (Loc,
19600 Subtype_Indication =>
19603 (Access_Definition (Comp_Def))));
19605 Set_Constant_Present
19606 (Type_Def, Constant_Present (Access_Definition (Comp_Def)));
19608 (Type_Def, All_Present (Access_Definition (Comp_Def)));
19611 Set_Null_Exclusion_Present
19613 Null_Exclusion_Present (Access_Definition (Comp_Def)));
19616 Make_Full_Type_Declaration (Loc,
19617 Defining_Identifier => Anon_Access,
19618 Type_Definition => Type_Def);
19620 Insert_Before (Typ_Decl, Decl);
19623 -- If an access to subprogram, create the extra formals
19625 if Present (Acc_Def) then
19626 Create_Extra_Formals (Designated_Type (Anon_Access));
19628 -- If an access to object, preserve entity of designated type,
19629 -- for ASIS use, before rewriting the component definition.
19636 Desig := Entity (Subtype_Indication (Type_Def));
19638 -- If the access definition is to the current record,
19639 -- the visible entity at this point is an incomplete
19640 -- type. Retrieve the full view to simplify ASIS queries
19642 if Ekind (Desig) = E_Incomplete_Type then
19643 Desig := Full_View (Desig);
19647 (Subtype_Mark (Access_Definition (Comp_Def)), Desig);
19652 Make_Component_Definition (Loc,
19653 Subtype_Indication =>
19654 New_Occurrence_Of (Anon_Access, Loc)));
19656 if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then
19657 Set_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type);
19659 Set_Ekind (Anon_Access, E_Anonymous_Access_Type);
19662 Set_Is_Local_Anonymous_Access (Anon_Access);
19668 if Present (Variant_Part (Comp_List)) then
19672 V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
19673 while Present (V) loop
19674 Check_Anonymous_Access_Components
19675 (Typ_Decl, Typ, Prev, Component_List (V));
19676 Next_Non_Pragma (V);
19680 end Check_Anonymous_Access_Components;
19682 ----------------------------------
19683 -- Preanalyze_Assert_Expression --
19684 ----------------------------------
19686 procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id) is
19688 In_Assertion_Expr := In_Assertion_Expr + 1;
19689 Preanalyze_Spec_Expression (N, T);
19690 In_Assertion_Expr := In_Assertion_Expr - 1;
19691 end Preanalyze_Assert_Expression;
19693 --------------------------------
19694 -- Preanalyze_Spec_Expression --
19695 --------------------------------
19697 procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is
19698 Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
19700 In_Spec_Expression := True;
19701 Preanalyze_And_Resolve (N, T);
19702 In_Spec_Expression := Save_In_Spec_Expression;
19703 end Preanalyze_Spec_Expression;
19705 -----------------------------
19706 -- Record_Type_Declaration --
19707 -----------------------------
19709 procedure Record_Type_Declaration
19714 Def : constant Node_Id := Type_Definition (N);
19715 Is_Tagged : Boolean;
19716 Tag_Comp : Entity_Id;
19719 -- These flags must be initialized before calling Process_Discriminants
19720 -- because this routine makes use of them.
19722 Set_Ekind (T, E_Record_Type);
19724 Init_Size_Align (T);
19725 Set_Interfaces (T, No_Elist);
19726 Set_Stored_Constraint (T, No_Elist);
19730 if Ada_Version < Ada_2005
19731 or else not Interface_Present (Def)
19733 if Limited_Present (Def) then
19734 Check_SPARK_Restriction ("limited is not allowed", N);
19737 if Abstract_Present (Def) then
19738 Check_SPARK_Restriction ("abstract is not allowed", N);
19741 -- The flag Is_Tagged_Type might have already been set by
19742 -- Find_Type_Name if it detected an error for declaration T. This
19743 -- arises in the case of private tagged types where the full view
19744 -- omits the word tagged.
19747 Tagged_Present (Def)
19748 or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
19750 Set_Is_Tagged_Type (T, Is_Tagged);
19751 Set_Is_Limited_Record (T, Limited_Present (Def));
19753 -- Type is abstract if full declaration carries keyword, or if
19754 -- previous partial view did.
19756 Set_Is_Abstract_Type (T, Is_Abstract_Type (T)
19757 or else Abstract_Present (Def));
19760 Check_SPARK_Restriction ("interface is not allowed", N);
19763 Analyze_Interface_Declaration (T, Def);
19765 if Present (Discriminant_Specifications (N)) then
19767 ("interface types cannot have discriminants",
19768 Defining_Identifier
19769 (First (Discriminant_Specifications (N))));
19773 -- First pass: if there are self-referential access components,
19774 -- create the required anonymous access type declarations, and if
19775 -- need be an incomplete type declaration for T itself.
19777 Check_Anonymous_Access_Components (N, T, Prev, Component_List (Def));
19779 if Ada_Version >= Ada_2005
19780 and then Present (Interface_List (Def))
19782 Check_Interfaces (N, Def);
19785 Ifaces_List : Elist_Id;
19788 -- Ada 2005 (AI-251): Collect the list of progenitors that are not
19789 -- already in the parents.
19793 Ifaces_List => Ifaces_List,
19794 Exclude_Parents => True);
19796 Set_Interfaces (T, Ifaces_List);
19800 -- Records constitute a scope for the component declarations within.
19801 -- The scope is created prior to the processing of these declarations.
19802 -- Discriminants are processed first, so that they are visible when
19803 -- processing the other components. The Ekind of the record type itself
19804 -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
19806 -- Enter record scope
19810 -- If an incomplete or private type declaration was already given for
19811 -- the type, then this scope already exists, and the discriminants have
19812 -- been declared within. We must verify that the full declaration
19813 -- matches the incomplete one.
19815 Check_Or_Process_Discriminants (N, T, Prev);
19817 Set_Is_Constrained (T, not Has_Discriminants (T));
19818 Set_Has_Delayed_Freeze (T, True);
19820 -- For tagged types add a manually analyzed component corresponding
19821 -- to the component _tag, the corresponding piece of tree will be
19822 -- expanded as part of the freezing actions if it is not a CPP_Class.
19826 -- Do not add the tag unless we are in expansion mode
19828 if Expander_Active then
19829 Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
19830 Enter_Name (Tag_Comp);
19832 Set_Ekind (Tag_Comp, E_Component);
19833 Set_Is_Tag (Tag_Comp);
19834 Set_Is_Aliased (Tag_Comp);
19835 Set_Etype (Tag_Comp, RTE (RE_Tag));
19836 Set_DT_Entry_Count (Tag_Comp, No_Uint);
19837 Set_Original_Record_Component (Tag_Comp, Tag_Comp);
19838 Init_Component_Location (Tag_Comp);
19840 -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
19841 -- implemented interfaces.
19843 if Has_Interfaces (T) then
19844 Add_Interface_Tag_Components (N, T);
19848 Make_Class_Wide_Type (T);
19849 Set_Direct_Primitive_Operations (T, New_Elmt_List);
19852 -- We must suppress range checks when processing record components in
19853 -- the presence of discriminants, since we don't want spurious checks to
19854 -- be generated during their analysis, but Suppress_Range_Checks flags
19855 -- must be reset the after processing the record definition.
19857 -- Note: this is the only use of Kill_Range_Checks, and is a bit odd,
19858 -- couldn't we just use the normal range check suppression method here.
19859 -- That would seem cleaner ???
19861 if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
19862 Set_Kill_Range_Checks (T, True);
19863 Record_Type_Definition (Def, Prev);
19864 Set_Kill_Range_Checks (T, False);
19866 Record_Type_Definition (Def, Prev);
19869 -- Exit from record scope
19873 -- Ada 2005 (AI-251 and AI-345): Derive the interface subprograms of all
19874 -- the implemented interfaces and associate them an aliased entity.
19877 and then not Is_Empty_List (Interface_List (Def))
19879 Derive_Progenitor_Subprograms (T, T);
19882 Check_Function_Writable_Actuals (N);
19883 end Record_Type_Declaration;
19885 ----------------------------
19886 -- Record_Type_Definition --
19887 ----------------------------
19889 procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
19890 Component : Entity_Id;
19891 Ctrl_Components : Boolean := False;
19892 Final_Storage_Only : Boolean;
19896 if Ekind (Prev_T) = E_Incomplete_Type then
19897 T := Full_View (Prev_T);
19902 -- In SPARK, tagged types and type extensions may only be declared in
19903 -- the specification of library unit packages.
19905 if Present (Def) and then Is_Tagged_Type (T) then
19911 if Nkind (Parent (Def)) = N_Full_Type_Declaration then
19912 Typ := Parent (Def);
19915 (Nkind (Parent (Def)) = N_Derived_Type_Definition);
19916 Typ := Parent (Parent (Def));
19919 Ctxt := Parent (Typ);
19921 if Nkind (Ctxt) = N_Package_Body
19922 and then Nkind (Parent (Ctxt)) = N_Compilation_Unit
19924 Check_SPARK_Restriction
19925 ("type should be defined in package specification", Typ);
19927 elsif Nkind (Ctxt) /= N_Package_Specification
19928 or else Nkind (Parent (Parent (Ctxt))) /= N_Compilation_Unit
19930 Check_SPARK_Restriction
19931 ("type should be defined in library unit package", Typ);
19936 Final_Storage_Only := not Is_Controlled (T);
19938 -- Ada 2005: check whether an explicit Limited is present in a derived
19939 -- type declaration.
19941 if Nkind (Parent (Def)) = N_Derived_Type_Definition
19942 and then Limited_Present (Parent (Def))
19944 Set_Is_Limited_Record (T);
19947 -- If the component list of a record type is defined by the reserved
19948 -- word null and there is no discriminant part, then the record type has
19949 -- no components and all records of the type are null records (RM 3.7)
19950 -- This procedure is also called to process the extension part of a
19951 -- record extension, in which case the current scope may have inherited
19955 or else No (Component_List (Def))
19956 or else Null_Present (Component_List (Def))
19958 if not Is_Tagged_Type (T) then
19959 Check_SPARK_Restriction ("non-tagged record cannot be null", Def);
19963 Analyze_Declarations (Component_Items (Component_List (Def)));
19965 if Present (Variant_Part (Component_List (Def))) then
19966 Check_SPARK_Restriction ("variant part is not allowed", Def);
19967 Analyze (Variant_Part (Component_List (Def)));
19971 -- After completing the semantic analysis of the record definition,
19972 -- record components, both new and inherited, are accessible. Set their
19973 -- kind accordingly. Exclude malformed itypes from illegal declarations,
19974 -- whose Ekind may be void.
19976 Component := First_Entity (Current_Scope);
19977 while Present (Component) loop
19978 if Ekind (Component) = E_Void
19979 and then not Is_Itype (Component)
19981 Set_Ekind (Component, E_Component);
19982 Init_Component_Location (Component);
19985 if Has_Task (Etype (Component)) then
19989 if Ekind (Component) /= E_Component then
19992 -- Do not set Has_Controlled_Component on a class-wide equivalent
19993 -- type. See Make_CW_Equivalent_Type.
19995 elsif not Is_Class_Wide_Equivalent_Type (T)
19996 and then (Has_Controlled_Component (Etype (Component))
19997 or else (Chars (Component) /= Name_uParent
19998 and then Is_Controlled (Etype (Component))))
20000 Set_Has_Controlled_Component (T, True);
20001 Final_Storage_Only :=
20003 and then Finalize_Storage_Only (Etype (Component));
20004 Ctrl_Components := True;
20007 Next_Entity (Component);
20010 -- A Type is Finalize_Storage_Only only if all its controlled components
20013 if Ctrl_Components then
20014 Set_Finalize_Storage_Only (T, Final_Storage_Only);
20017 -- Place reference to end record on the proper entity, which may
20018 -- be a partial view.
20020 if Present (Def) then
20021 Process_End_Label (Def, 'e', Prev_T);
20023 end Record_Type_Definition;
20025 ------------------------
20026 -- Replace_Components --
20027 ------------------------
20029 procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
20030 function Process (N : Node_Id) return Traverse_Result;
20036 function Process (N : Node_Id) return Traverse_Result is
20040 if Nkind (N) = N_Discriminant_Specification then
20041 Comp := First_Discriminant (Typ);
20042 while Present (Comp) loop
20043 if Chars (Comp) = Chars (Defining_Identifier (N)) then
20044 Set_Defining_Identifier (N, Comp);
20048 Next_Discriminant (Comp);
20051 elsif Nkind (N) = N_Component_Declaration then
20052 Comp := First_Component (Typ);
20053 while Present (Comp) loop
20054 if Chars (Comp) = Chars (Defining_Identifier (N)) then
20055 Set_Defining_Identifier (N, Comp);
20059 Next_Component (Comp);
20066 procedure Replace is new Traverse_Proc (Process);
20068 -- Start of processing for Replace_Components
20072 end Replace_Components;
20074 -------------------------------
20075 -- Set_Completion_Referenced --
20076 -------------------------------
20078 procedure Set_Completion_Referenced (E : Entity_Id) is
20080 -- If in main unit, mark entity that is a completion as referenced,
20081 -- warnings go on the partial view when needed.
20083 if In_Extended_Main_Source_Unit (E) then
20084 Set_Referenced (E);
20086 end Set_Completion_Referenced;
20088 ---------------------
20089 -- Set_Fixed_Range --
20090 ---------------------
20092 -- The range for fixed-point types is complicated by the fact that we
20093 -- do not know the exact end points at the time of the declaration. This
20094 -- is true for three reasons:
20096 -- A size clause may affect the fudging of the end-points.
20097 -- A small clause may affect the values of the end-points.
20098 -- We try to include the end-points if it does not affect the size.
20100 -- This means that the actual end-points must be established at the
20101 -- point when the type is frozen. Meanwhile, we first narrow the range
20102 -- as permitted (so that it will fit if necessary in a small specified
20103 -- size), and then build a range subtree with these narrowed bounds.
20104 -- Set_Fixed_Range constructs the range from real literal values, and
20105 -- sets the range as the Scalar_Range of the given fixed-point type entity.
20107 -- The parent of this range is set to point to the entity so that it is
20108 -- properly hooked into the tree (unlike normal Scalar_Range entries for
20109 -- other scalar types, which are just pointers to the range in the
20110 -- original tree, this would otherwise be an orphan).
20112 -- The tree is left unanalyzed. When the type is frozen, the processing
20113 -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
20114 -- analyzed, and uses this as an indication that it should complete
20115 -- work on the range (it will know the final small and size values).
20117 procedure Set_Fixed_Range
20123 S : constant Node_Id :=
20125 Low_Bound => Make_Real_Literal (Loc, Lo),
20126 High_Bound => Make_Real_Literal (Loc, Hi));
20128 Set_Scalar_Range (E, S);
20131 -- Before the freeze point, the bounds of a fixed point are universal
20132 -- and carry the corresponding type.
20134 Set_Etype (Low_Bound (S), Universal_Real);
20135 Set_Etype (High_Bound (S), Universal_Real);
20136 end Set_Fixed_Range;
20138 ----------------------------------
20139 -- Set_Scalar_Range_For_Subtype --
20140 ----------------------------------
20142 procedure Set_Scalar_Range_For_Subtype
20143 (Def_Id : Entity_Id;
20147 Kind : constant Entity_Kind := Ekind (Def_Id);
20150 -- Defend against previous error
20152 if Nkind (R) = N_Error then
20156 Set_Scalar_Range (Def_Id, R);
20158 -- We need to link the range into the tree before resolving it so
20159 -- that types that are referenced, including importantly the subtype
20160 -- itself, are properly frozen (Freeze_Expression requires that the
20161 -- expression be properly linked into the tree). Of course if it is
20162 -- already linked in, then we do not disturb the current link.
20164 if No (Parent (R)) then
20165 Set_Parent (R, Def_Id);
20168 -- Reset the kind of the subtype during analysis of the range, to
20169 -- catch possible premature use in the bounds themselves.
20171 Set_Ekind (Def_Id, E_Void);
20172 Process_Range_Expr_In_Decl (R, Subt);
20173 Set_Ekind (Def_Id, Kind);
20174 end Set_Scalar_Range_For_Subtype;
20176 --------------------------------------------------------
20177 -- Set_Stored_Constraint_From_Discriminant_Constraint --
20178 --------------------------------------------------------
20180 procedure Set_Stored_Constraint_From_Discriminant_Constraint
20184 -- Make sure set if encountered during Expand_To_Stored_Constraint
20186 Set_Stored_Constraint (E, No_Elist);
20188 -- Give it the right value
20190 if Is_Constrained (E) and then Has_Discriminants (E) then
20191 Set_Stored_Constraint (E,
20192 Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
20194 end Set_Stored_Constraint_From_Discriminant_Constraint;
20196 -------------------------------------
20197 -- Signed_Integer_Type_Declaration --
20198 -------------------------------------
20200 procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
20201 Implicit_Base : Entity_Id;
20202 Base_Typ : Entity_Id;
20205 Errs : Boolean := False;
20209 function Can_Derive_From (E : Entity_Id) return Boolean;
20210 -- Determine whether given bounds allow derivation from specified type
20212 procedure Check_Bound (Expr : Node_Id);
20213 -- Check bound to make sure it is integral and static. If not, post
20214 -- appropriate error message and set Errs flag
20216 ---------------------
20217 -- Can_Derive_From --
20218 ---------------------
20220 -- Note we check both bounds against both end values, to deal with
20221 -- strange types like ones with a range of 0 .. -12341234.
20223 function Can_Derive_From (E : Entity_Id) return Boolean is
20224 Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
20225 Hi : constant Uint := Expr_Value (Type_High_Bound (E));
20227 return Lo <= Lo_Val and then Lo_Val <= Hi
20229 Lo <= Hi_Val and then Hi_Val <= Hi;
20230 end Can_Derive_From;
20236 procedure Check_Bound (Expr : Node_Id) is
20238 -- If a range constraint is used as an integer type definition, each
20239 -- bound of the range must be defined by a static expression of some
20240 -- integer type, but the two bounds need not have the same integer
20241 -- type (Negative bounds are allowed.) (RM 3.5.4)
20243 if not Is_Integer_Type (Etype (Expr)) then
20245 ("integer type definition bounds must be of integer type", Expr);
20248 elsif not Is_OK_Static_Expression (Expr) then
20249 Flag_Non_Static_Expr
20250 ("non-static expression used for integer type bound!", Expr);
20253 -- The bounds are folded into literals, and we set their type to be
20254 -- universal, to avoid typing difficulties: we cannot set the type
20255 -- of the literal to the new type, because this would be a forward
20256 -- reference for the back end, and if the original type is user-
20257 -- defined this can lead to spurious semantic errors (e.g. 2928-003).
20260 if Is_Entity_Name (Expr) then
20261 Fold_Uint (Expr, Expr_Value (Expr), True);
20264 Set_Etype (Expr, Universal_Integer);
20268 -- Start of processing for Signed_Integer_Type_Declaration
20271 -- Create an anonymous base type
20274 Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
20276 -- Analyze and check the bounds, they can be of any integer type
20278 Lo := Low_Bound (Def);
20279 Hi := High_Bound (Def);
20281 -- Arbitrarily use Integer as the type if either bound had an error
20283 if Hi = Error or else Lo = Error then
20284 Base_Typ := Any_Integer;
20285 Set_Error_Posted (T, True);
20287 -- Here both bounds are OK expressions
20290 Analyze_And_Resolve (Lo, Any_Integer);
20291 Analyze_And_Resolve (Hi, Any_Integer);
20297 Hi := Type_High_Bound (Standard_Long_Long_Integer);
20298 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
20301 -- Find type to derive from
20303 Lo_Val := Expr_Value (Lo);
20304 Hi_Val := Expr_Value (Hi);
20306 if Can_Derive_From (Standard_Short_Short_Integer) then
20307 Base_Typ := Base_Type (Standard_Short_Short_Integer);
20309 elsif Can_Derive_From (Standard_Short_Integer) then
20310 Base_Typ := Base_Type (Standard_Short_Integer);
20312 elsif Can_Derive_From (Standard_Integer) then
20313 Base_Typ := Base_Type (Standard_Integer);
20315 elsif Can_Derive_From (Standard_Long_Integer) then
20316 Base_Typ := Base_Type (Standard_Long_Integer);
20318 elsif Can_Derive_From (Standard_Long_Long_Integer) then
20319 Base_Typ := Base_Type (Standard_Long_Long_Integer);
20322 Base_Typ := Base_Type (Standard_Long_Long_Integer);
20323 Error_Msg_N ("integer type definition bounds out of range", Def);
20324 Hi := Type_High_Bound (Standard_Long_Long_Integer);
20325 Lo := Type_Low_Bound (Standard_Long_Long_Integer);
20329 -- Complete both implicit base and declared first subtype entities
20331 Set_Etype (Implicit_Base, Base_Typ);
20332 Set_Size_Info (Implicit_Base, (Base_Typ));
20333 Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
20334 Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
20336 Set_Ekind (T, E_Signed_Integer_Subtype);
20337 Set_Etype (T, Implicit_Base);
20339 -- In formal verification mode, restrict the base type's range to the
20340 -- minimum allowed by RM 3.5.4, namely the smallest symmetric range
20341 -- around zero with a possible extra negative value that contains the
20342 -- subtype range. Keep Size, RM_Size and First_Rep_Item info, which
20343 -- should not be relied upon in formal verification.
20345 if SPARK_Strict_Mode then
20349 Dloc : constant Source_Ptr := Sloc (Def);
20355 -- If the subtype range is empty, the smallest base type range
20356 -- is the symmetric range around zero containing Lo_Val and
20359 if UI_Gt (Lo_Val, Hi_Val) then
20360 Sym_Hi_Val := UI_Max (UI_Abs (Lo_Val), UI_Abs (Hi_Val));
20361 Sym_Lo_Val := UI_Negate (Sym_Hi_Val);
20363 -- Otherwise, if the subtype range is not empty and Hi_Val has
20364 -- the largest absolute value, Hi_Val is non negative and the
20365 -- smallest base type range is the symmetric range around zero
20366 -- containing Hi_Val.
20368 elsif UI_Le (UI_Abs (Lo_Val), UI_Abs (Hi_Val)) then
20369 Sym_Hi_Val := Hi_Val;
20370 Sym_Lo_Val := UI_Negate (Hi_Val);
20372 -- Otherwise, the subtype range is not empty, Lo_Val has the
20373 -- strictly largest absolute value, Lo_Val is negative and the
20374 -- smallest base type range is the symmetric range around zero
20375 -- with an extra negative value Lo_Val.
20378 Sym_Lo_Val := Lo_Val;
20379 Sym_Hi_Val := UI_Sub (UI_Negate (Lo_Val), Uint_1);
20382 Lbound := Make_Integer_Literal (Dloc, Sym_Lo_Val);
20383 Ubound := Make_Integer_Literal (Dloc, Sym_Hi_Val);
20384 Set_Is_Static_Expression (Lbound);
20385 Set_Is_Static_Expression (Ubound);
20386 Analyze_And_Resolve (Lbound, Any_Integer);
20387 Analyze_And_Resolve (Ubound, Any_Integer);
20389 Bounds := Make_Range (Dloc, Lbound, Ubound);
20390 Set_Etype (Bounds, Base_Typ);
20392 Set_Scalar_Range (Implicit_Base, Bounds);
20396 Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
20399 Set_Size_Info (T, (Implicit_Base));
20400 Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
20401 Set_Scalar_Range (T, Def);
20402 Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
20403 Set_Is_Constrained (T);
20404 end Signed_Integer_Type_Declaration;