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diff --git a/gcc-4.2.1/gcc/ada/sem_ch3.adb b/gcc-4.2.1/gcc/ada/sem_ch3.adb new file mode 100644 index 000000000..7bb4661a7 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/sem_ch3.adb @@ -0,0 +1,15677 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ C H 3 -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2006, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Checks; use Checks; +with Elists; use Elists; +with Einfo; use Einfo; +with Errout; use Errout; +with Eval_Fat; use Eval_Fat; +with Exp_Ch3; use Exp_Ch3; +with Exp_Dist; use Exp_Dist; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; +with Freeze; use Freeze; +with Itypes; use Itypes; +with Layout; use Layout; +with Lib; use Lib; +with Lib.Xref; use Lib.Xref; +with Namet; use Namet; +with Nmake; use Nmake; +with Opt; use Opt; +with Restrict; use Restrict; +with Rident; use Rident; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Case; use Sem_Case; +with Sem_Cat; use Sem_Cat; +with Sem_Ch6; use Sem_Ch6; +with Sem_Ch7; use Sem_Ch7; +with Sem_Ch8; use Sem_Ch8; +with Sem_Ch13; use Sem_Ch13; +with Sem_Disp; use Sem_Disp; +with Sem_Dist; use Sem_Dist; +with Sem_Elim; use Sem_Elim; +with Sem_Eval; use Sem_Eval; +with Sem_Mech; use Sem_Mech; +with Sem_Res; use Sem_Res; +with Sem_Smem; use Sem_Smem; +with Sem_Type; use Sem_Type; +with Sem_Util; use Sem_Util; +with Sem_Warn; use Sem_Warn; +with Stand; use Stand; +with Sinfo; use Sinfo; +with Snames; use Snames; +with Targparm; use Targparm; +with Tbuild; use Tbuild; +with Ttypes; use Ttypes; +with Uintp; use Uintp; +with Urealp; use Urealp; + +package body Sem_Ch3 is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Add_Interface_Tag_Components + (N : Node_Id; Typ : Entity_Id); + -- Ada 2005 (AI-251): Add the tag components corresponding to all the + -- abstract interface types implemented by a record type or a derived + -- record type. + + procedure Build_Derived_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Is_Completion : Boolean; + Derive_Subps : Boolean := True); + -- Create and decorate a Derived_Type given the Parent_Type entity. N is + -- the N_Full_Type_Declaration node containing the derived type definition. + -- Parent_Type is the entity for the parent type in the derived type + -- definition and Derived_Type the actual derived type. Is_Completion must + -- be set to False if Derived_Type is the N_Defining_Identifier node in N + -- (ie Derived_Type = Defining_Identifier (N)). In this case N is not the + -- completion of a private type declaration. If Is_Completion is set to + -- True, N is the completion of a private type declaration and Derived_Type + -- is different from the defining identifier inside N (i.e. Derived_Type /= + -- Defining_Identifier (N)). Derive_Subps indicates whether the parent + -- subprograms should be derived. The only case where this parameter is + -- False is when Build_Derived_Type is recursively called to process an + -- implicit derived full type for a type derived from a private type (in + -- that case the subprograms must only be derived for the private view of + -- the type). + + -- ??? These flags need a bit of re-examination and re-documentation: + -- ??? are they both necessary (both seem related to the recursion)? + + procedure Build_Derived_Access_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id); + -- Subsidiary procedure to Build_Derived_Type. For a derived access type, + -- create an implicit base if the parent type is constrained or if the + -- subtype indication has a constraint. + + procedure Build_Derived_Array_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id); + -- Subsidiary procedure to Build_Derived_Type. For a derived array type, + -- create an implicit base if the parent type is constrained or if the + -- subtype indication has a constraint. + + procedure Build_Derived_Concurrent_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id); + -- Subsidiary procedure to Build_Derived_Type. For a derived task or pro- + -- tected type, inherit entries and protected subprograms, check legality + -- of discriminant constraints if any. + + procedure Build_Derived_Enumeration_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id); + -- Subsidiary procedure to Build_Derived_Type. For a derived enumeration + -- type, we must create a new list of literals. Types derived from + -- Character and Wide_Character are special-cased. + + procedure Build_Derived_Numeric_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id); + -- Subsidiary procedure to Build_Derived_Type. For numeric types, create + -- an anonymous base type, and propagate constraint to subtype if needed. + + procedure Build_Derived_Private_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Is_Completion : Boolean; + Derive_Subps : Boolean := True); + -- Subsidiary procedure to Build_Derived_Type. This procedure is complex + -- because the parent may or may not have a completion, and the derivation + -- may itself be a completion. + + procedure Build_Derived_Record_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Derive_Subps : Boolean := True); + -- Subsidiary procedure for Build_Derived_Type and + -- Analyze_Private_Extension_Declaration used for tagged and untagged + -- record types. All parameters are as in Build_Derived_Type except that + -- N, in addition to being an N_Full_Type_Declaration node, can also be an + -- N_Private_Extension_Declaration node. See the definition of this routine + -- for much more info. Derive_Subps indicates whether subprograms should + -- be derived from the parent type. The only case where Derive_Subps is + -- False is for an implicit derived full type for a type derived from a + -- private type (see Build_Derived_Type). + + procedure Complete_Subprograms_Derivation + (Partial_View : Entity_Id; + Derived_Type : Entity_Id); + -- Ada 2005 (AI-251): Used to complete type derivation of private tagged + -- types implementing interfaces. In this case some interface primitives + -- may have been overriden with the partial-view and, instead of + -- re-calculating them, they are included in the list of primitive + -- operations of the full-view. + + function Inherit_Components + (N : Node_Id; + Parent_Base : Entity_Id; + Derived_Base : Entity_Id; + Is_Tagged : Boolean; + Inherit_Discr : Boolean; + Discs : Elist_Id) return Elist_Id; + -- Called from Build_Derived_Record_Type to inherit the components of + -- Parent_Base (a base type) into the Derived_Base (the derived base type). + -- For more information on derived types and component inheritance please + -- consult the comment above the body of Build_Derived_Record_Type. + -- + -- N is the original derived type declaration + -- + -- Is_Tagged is set if we are dealing with tagged types + -- + -- If Inherit_Discr is set, Derived_Base inherits its discriminants + -- from Parent_Base, otherwise no discriminants are inherited. + -- + -- Discs gives the list of constraints that apply to Parent_Base in the + -- derived type declaration. If Discs is set to No_Elist, then we have + -- the following situation: + -- + -- type Parent (D1..Dn : ..) is [tagged] record ...; + -- type Derived is new Parent [with ...]; + -- + -- which gets treated as + -- + -- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...]; + -- + -- For untagged types the returned value is an association list. The list + -- starts from the association (Parent_Base => Derived_Base), and then it + -- contains a sequence of the associations of the form + -- + -- (Old_Component => New_Component), + -- + -- where Old_Component is the Entity_Id of a component in Parent_Base + -- and New_Component is the Entity_Id of the corresponding component + -- in Derived_Base. For untagged records, this association list is + -- needed when copying the record declaration for the derived base. + -- In the tagged case the value returned is irrelevant. + + procedure Build_Discriminal (Discrim : Entity_Id); + -- Create the discriminal corresponding to discriminant Discrim, that is + -- the parameter corresponding to Discrim to be used in initialization + -- procedures for the type where Discrim is a discriminant. Discriminals + -- are not used during semantic analysis, and are not fully defined + -- entities until expansion. Thus they are not given a scope until + -- initialization procedures are built. + + function Build_Discriminant_Constraints + (T : Entity_Id; + Def : Node_Id; + Derived_Def : Boolean := False) return Elist_Id; + -- Validate discriminant constraints, and return the list of the + -- constraints in order of discriminant declarations. T is the + -- discriminated unconstrained type. Def is the N_Subtype_Indication node + -- where the discriminants constraints for T are specified. Derived_Def is + -- True if we are building the discriminant constraints in a derived type + -- definition of the form "type D (...) is new T (xxx)". In this case T is + -- the parent type and Def is the constraint "(xxx)" on T and this routine + -- sets the Corresponding_Discriminant field of the discriminants in the + -- derived type D to point to the corresponding discriminants in the parent + -- type T. + + procedure Build_Discriminated_Subtype + (T : Entity_Id; + Def_Id : Entity_Id; + Elist : Elist_Id; + Related_Nod : Node_Id; + For_Access : Boolean := False); + -- Subsidiary procedure to Constrain_Discriminated_Type and to + -- Process_Incomplete_Dependents. Given + -- + -- T (a possibly discriminated base type) + -- Def_Id (a very partially built subtype for T), + -- + -- the call completes Def_Id to be the appropriate E_*_Subtype. + -- + -- The Elist is the list of discriminant constraints if any (it is set to + -- No_Elist if T is not a discriminated type, and to an empty list if + -- T has discriminants but there are no discriminant constraints). The + -- Related_Nod is the same as Decl_Node in Create_Constrained_Components. + -- The For_Access says whether or not this subtype is really constraining + -- an access type. That is its sole purpose is the designated type of an + -- access type -- in which case a Private_Subtype Is_For_Access_Subtype + -- is built to avoid freezing T when the access subtype is frozen. + + function Build_Scalar_Bound + (Bound : Node_Id; + Par_T : Entity_Id; + Der_T : Entity_Id) return Node_Id; + -- The bounds of a derived scalar type are conversions of the bounds of + -- the parent type. Optimize the representation if the bounds are literals. + -- Needs a more complete spec--what are the parameters exactly, and what + -- exactly is the returned value, and how is Bound affected??? + + procedure Build_Underlying_Full_View + (N : Node_Id; + Typ : Entity_Id; + Par : Entity_Id); + -- If the completion of a private type is itself derived from a private + -- type, or if the full view of a private subtype is itself private, the + -- back-end has no way to compute the actual size of this type. We build + -- an internal subtype declaration of the proper parent type to convey + -- this information. This extra mechanism is needed because a full + -- view cannot itself have a full view (it would get clobbered during + -- view exchanges). + + procedure Check_Access_Discriminant_Requires_Limited + (D : Node_Id; + Loc : Node_Id); + -- Check the restriction that the type to which an access discriminant + -- belongs must be a concurrent type or a descendant of a type with + -- the reserved word 'limited' in its declaration. + + procedure Check_Delta_Expression (E : Node_Id); + -- Check that the expression represented by E is suitable for use + -- as a delta expression, i.e. it is of real type and is static. + + procedure Check_Digits_Expression (E : Node_Id); + -- Check that the expression represented by E is suitable for use as + -- a digits expression, i.e. it is of integer type, positive and static. + + procedure Check_Initialization (T : Entity_Id; Exp : Node_Id); + -- Validate the initialization of an object declaration. T is the + -- required type, and Exp is the initialization expression. + + procedure Check_Or_Process_Discriminants + (N : Node_Id; + T : Entity_Id; + Prev : Entity_Id := Empty); + -- If T is the full declaration of an incomplete or private type, check + -- the conformance of the discriminants, otherwise process them. Prev + -- is the entity of the partial declaration, if any. + + procedure Check_Real_Bound (Bound : Node_Id); + -- Check given bound for being of real type and static. If not, post an + -- appropriate message, and rewrite the bound with the real literal zero. + + procedure Constant_Redeclaration + (Id : Entity_Id; + N : Node_Id; + T : out Entity_Id); + -- Various checks on legality of full declaration of deferred constant. + -- Id is the entity for the redeclaration, N is the N_Object_Declaration, + -- node. The caller has not yet set any attributes of this entity. + + procedure Convert_Scalar_Bounds + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Loc : Source_Ptr); + -- For derived scalar types, convert the bounds in the type definition + -- to the derived type, and complete their analysis. Given a constraint + -- of the form: + -- .. new T range Lo .. Hi; + -- Lo and Hi are analyzed and resolved with T'Base, the parent_type. + -- The bounds of the derived type (the anonymous base) are copies of + -- Lo and Hi. Finally, the bounds of the derived subtype are conversions + -- of those bounds to the derived_type, so that their typing is + -- consistent. + + procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id); + -- Copies attributes from array base type T2 to array base type T1. + -- Copies only attributes that apply to base types, but not subtypes. + + procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id); + -- Copies attributes from array subtype T2 to array subtype T1. Copies + -- attributes that apply to both subtypes and base types. + + procedure Create_Constrained_Components + (Subt : Entity_Id; + Decl_Node : Node_Id; + Typ : Entity_Id; + Constraints : Elist_Id); + -- Build the list of entities for a constrained discriminated record + -- subtype. If a component depends on a discriminant, replace its subtype + -- using the discriminant values in the discriminant constraint. + -- Subt is the defining identifier for the subtype whose list of + -- constrained entities we will create. Decl_Node is the type declaration + -- node where we will attach all the itypes created. Typ is the base + -- discriminated type for the subtype Subt. Constraints is the list of + -- discriminant constraints for Typ. + + function Constrain_Component_Type + (Comp : Entity_Id; + Constrained_Typ : Entity_Id; + Related_Node : Node_Id; + Typ : Entity_Id; + Constraints : Elist_Id) return Entity_Id; + -- Given a discriminated base type Typ, a list of discriminant constraint + -- Constraints for Typ and a component of Typ, with type Compon_Type, + -- create and return the type corresponding to Compon_type where all + -- discriminant references are replaced with the corresponding + -- constraint. If no discriminant references occur in Compon_Typ then + -- return it as is. Constrained_Typ is the final constrained subtype to + -- which the constrained Compon_Type belongs. Related_Node is the node + -- where we will attach all the itypes created. + + procedure Constrain_Access + (Def_Id : in out Entity_Id; + S : Node_Id; + Related_Nod : Node_Id); + -- Apply a list of constraints to an access type. If Def_Id is empty, it is + -- an anonymous type created for a subtype indication. In that case it is + -- created in the procedure and attached to Related_Nod. + + procedure Constrain_Array + (Def_Id : in out Entity_Id; + SI : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id; + Suffix : Character); + -- Apply a list of index constraints to an unconstrained array type. The + -- first parameter is the entity for the resulting subtype. A value of + -- Empty for Def_Id indicates that an implicit type must be created, but + -- creation is delayed (and must be done by this procedure) because other + -- subsidiary implicit types must be created first (which is why Def_Id + -- is an in/out parameter). The second parameter is a subtype indication + -- node for the constrained array to be created (e.g. something of the + -- form string (1 .. 10)). Related_Nod gives the place where this type + -- has to be inserted in the tree. The Related_Id and Suffix parameters + -- are used to build the associated Implicit type name. + + procedure Constrain_Concurrent + (Def_Id : in out Entity_Id; + SI : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id; + Suffix : Character); + -- Apply list of discriminant constraints to an unconstrained concurrent + -- type. + -- + -- SI is the N_Subtype_Indication node containing the constraint and + -- the unconstrained type to constrain. + -- + -- Def_Id is the entity for the resulting constrained subtype. A value + -- of Empty for Def_Id indicates that an implicit type must be created, + -- but creation is delayed (and must be done by this procedure) because + -- other subsidiary implicit types must be created first (which is why + -- Def_Id is an in/out parameter). + -- + -- Related_Nod gives the place where this type has to be inserted + -- in the tree + -- + -- The last two arguments are used to create its external name if needed. + + function Constrain_Corresponding_Record + (Prot_Subt : Entity_Id; + Corr_Rec : Entity_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id) return Entity_Id; + -- When constraining a protected type or task type with discriminants, + -- constrain the corresponding record with the same discriminant values. + + procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id); + -- Constrain a decimal fixed point type with a digits constraint and/or a + -- range constraint, and build E_Decimal_Fixed_Point_Subtype entity. + + procedure Constrain_Discriminated_Type + (Def_Id : Entity_Id; + S : Node_Id; + Related_Nod : Node_Id; + For_Access : Boolean := False); + -- Process discriminant constraints of composite type. Verify that values + -- have been provided for all discriminants, that the original type is + -- unconstrained, and that the types of the supplied expressions match + -- the discriminant types. The first three parameters are like in routine + -- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation + -- of For_Access. + + procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id); + -- Constrain an enumeration type with a range constraint. This is identical + -- to Constrain_Integer, but for the Ekind of the resulting subtype. + + procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id); + -- Constrain a floating point type with either a digits constraint + -- and/or a range constraint, building a E_Floating_Point_Subtype. + + procedure Constrain_Index + (Index : Node_Id; + S : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id; + Suffix : Character; + Suffix_Index : Nat); + -- Process an index constraint in a constrained array declaration. The + -- constraint can be a subtype name, or a range with or without an + -- explicit subtype mark. The index is the corresponding index of the + -- unconstrained array. The Related_Id and Suffix parameters are used to + -- build the associated Implicit type name. + + procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id); + -- Build subtype of a signed or modular integer type + + procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id); + -- Constrain an ordinary fixed point type with a range constraint, and + -- build an E_Ordinary_Fixed_Point_Subtype entity. + + procedure Copy_And_Swap (Priv, Full : Entity_Id); + -- Copy the Priv entity into the entity of its full declaration + -- then swap the two entities in such a manner that the former private + -- type is now seen as a full type. + + procedure Decimal_Fixed_Point_Type_Declaration + (T : Entity_Id; + Def : Node_Id); + -- Create a new decimal fixed point type, and apply the constraint to + -- obtain a subtype of this new type. + + procedure Complete_Private_Subtype + (Priv : Entity_Id; + Full : Entity_Id; + Full_Base : Entity_Id; + Related_Nod : Node_Id); + -- Complete the implicit full view of a private subtype by setting the + -- appropriate semantic fields. If the full view of the parent is a record + -- type, build constrained components of subtype. + + procedure Derive_Interface_Subprograms + (Derived_Type : Entity_Id); + -- Ada 2005 (AI-251): Subsidiary procedure to Build_Derived_Record_Type. + -- Traverse the list of implemented interfaces and derive all their + -- subprograms. + + procedure Derived_Standard_Character + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id); + -- Subsidiary procedure to Build_Derived_Enumeration_Type which handles + -- derivations from types Standard.Character and Standard.Wide_Character. + + procedure Derived_Type_Declaration + (T : Entity_Id; + N : Node_Id; + Is_Completion : Boolean); + -- Process a derived type declaration. This routine will invoke + -- Build_Derived_Type to process the actual derived type definition. + -- Parameters N and Is_Completion have the same meaning as in + -- Build_Derived_Type. T is the N_Defining_Identifier for the entity + -- defined in the N_Full_Type_Declaration node N, that is T is the derived + -- type. + + procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id); + -- Insert each literal in symbol table, as an overloadable identifier. Each + -- enumeration type is mapped into a sequence of integers, and each literal + -- is defined as a constant with integer value. If any of the literals are + -- character literals, the type is a character type, which means that + -- strings are legal aggregates for arrays of components of the type. + + function Expand_To_Stored_Constraint + (Typ : Entity_Id; + Constraint : Elist_Id) return Elist_Id; + -- Given a Constraint (i.e. a list of expressions) on the discriminants of + -- Typ, expand it into a constraint on the stored discriminants and return + -- the new list of expressions constraining the stored discriminants. + + function Find_Type_Of_Object + (Obj_Def : Node_Id; + Related_Nod : Node_Id) return Entity_Id; + -- Get type entity for object referenced by Obj_Def, attaching the + -- implicit types generated to Related_Nod + + procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id); + -- Create a new float, and apply the constraint to obtain subtype of it + + function Has_Range_Constraint (N : Node_Id) return Boolean; + -- Given an N_Subtype_Indication node N, return True if a range constraint + -- is present, either directly, or as part of a digits or delta constraint. + -- In addition, a digits constraint in the decimal case returns True, since + -- it establishes a default range if no explicit range is present. + + function Is_Valid_Constraint_Kind + (T_Kind : Type_Kind; + Constraint_Kind : Node_Kind) return Boolean; + -- Returns True if it is legal to apply the given kind of constraint to the + -- given kind of type (index constraint to an array type, for example). + + procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id); + -- Create new modular type. Verify that modulus is in bounds and is + -- a power of two (implementation restriction). + + procedure New_Concatenation_Op (Typ : Entity_Id); + -- Create an abbreviated declaration for an operator in order to + -- materialize concatenation on array types. + + procedure Ordinary_Fixed_Point_Type_Declaration + (T : Entity_Id; + Def : Node_Id); + -- Create a new ordinary fixed point type, and apply the constraint to + -- obtain subtype of it. + + procedure Prepare_Private_Subtype_Completion + (Id : Entity_Id; + Related_Nod : Node_Id); + -- Id is a subtype of some private type. Creates the full declaration + -- associated with Id whenever possible, i.e. when the full declaration + -- of the base type is already known. Records each subtype into + -- Private_Dependents of the base type. + + procedure Process_Incomplete_Dependents + (N : Node_Id; + Full_T : Entity_Id; + Inc_T : Entity_Id); + -- Process all entities that depend on an incomplete type. There include + -- subtypes, subprogram types that mention the incomplete type in their + -- profiles, and subprogram with access parameters that designate the + -- incomplete type. + + -- Inc_T is the defining identifier of an incomplete type declaration, its + -- Ekind is E_Incomplete_Type. + -- + -- N is the corresponding N_Full_Type_Declaration for Inc_T. + -- + -- Full_T is N's defining identifier. + -- + -- Subtypes of incomplete types with discriminants are completed when the + -- parent type is. This is simpler than private subtypes, because they can + -- only appear in the same scope, and there is no need to exchange views. + -- Similarly, access_to_subprogram types may have a parameter or a return + -- type that is an incomplete type, and that must be replaced with the + -- full type. + + -- If the full type is tagged, subprogram with access parameters that + -- designated the incomplete may be primitive operations of the full type, + -- and have to be processed accordingly. + + procedure Process_Real_Range_Specification (Def : Node_Id); + -- Given the type definition for a real type, this procedure processes + -- and checks the real range specification of this type definition if + -- one is present. If errors are found, error messages are posted, and + -- the Real_Range_Specification of Def is reset to Empty. + + procedure Record_Type_Declaration + (T : Entity_Id; + N : Node_Id; + Prev : Entity_Id); + -- Process a record type declaration (for both untagged and tagged + -- records). Parameters T and N are exactly like in procedure + -- Derived_Type_Declaration, except that no flag Is_Completion is needed + -- for this routine. If this is the completion of an incomplete type + -- declaration, Prev is the entity of the incomplete declaration, used for + -- cross-referencing. Otherwise Prev = T. + + procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id); + -- This routine is used to process the actual record type definition + -- (both for untagged and tagged records). Def is a record type + -- definition node. This procedure analyzes the components in this + -- record type definition. Prev_T is the entity for the enclosing record + -- type. It is provided so that its Has_Task flag can be set if any of + -- the component have Has_Task set. If the declaration is the completion + -- of an incomplete type declaration, Prev_T is the original incomplete + -- type, whose full view is the record type. + + procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id); + -- Subsidiary to Build_Derived_Record_Type. For untagged records, we + -- build a copy of the declaration tree of the parent, and we create + -- independently the list of components for the derived type. Semantic + -- information uses the component entities, but record representation + -- clauses are validated on the declaration tree. This procedure replaces + -- discriminants and components in the declaration with those that have + -- been created by Inherit_Components. + + procedure Set_Fixed_Range + (E : Entity_Id; + Loc : Source_Ptr; + Lo : Ureal; + Hi : Ureal); + -- Build a range node with the given bounds and set it as the Scalar_Range + -- of the given fixed-point type entity. Loc is the source location used + -- for the constructed range. See body for further details. + + procedure Set_Scalar_Range_For_Subtype + (Def_Id : Entity_Id; + R : Node_Id; + Subt : Entity_Id); + -- This routine is used to set the scalar range field for a subtype given + -- Def_Id, the entity for the subtype, and R, the range expression for the + -- scalar range. Subt provides the parent subtype to be used to analyze, + -- resolve, and check the given range. + + procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id); + -- Create a new signed integer entity, and apply the constraint to obtain + -- the required first named subtype of this type. + + procedure Set_Stored_Constraint_From_Discriminant_Constraint + (E : Entity_Id); + -- E is some record type. This routine computes E's Stored_Constraint + -- from its Discriminant_Constraint. + + ----------------------- + -- Access_Definition -- + ----------------------- + + function Access_Definition + (Related_Nod : Node_Id; + N : Node_Id) return Entity_Id + is + Anon_Type : Entity_Id; + Desig_Type : Entity_Id; + + begin + if Is_Entry (Current_Scope) + and then Is_Task_Type (Etype (Scope (Current_Scope))) + then + Error_Msg_N ("task entries cannot have access parameters", N); + end if; + + -- Ada 2005: for an object declaration the corresponding anonymous + -- type is declared in the current scope. + + if Nkind (Related_Nod) = N_Object_Declaration then + Anon_Type := + Create_Itype + (E_Anonymous_Access_Type, Related_Nod, + Scope_Id => Current_Scope); + + -- For the anonymous function result case, retrieve the scope of + -- the function specification's associated entity rather than using + -- the current scope. The current scope will be the function itself + -- if the formal part is currently being analyzed, but will be the + -- parent scope in the case of a parameterless function, and we + -- always want to use the function's parent scope. + + elsif Nkind (Related_Nod) = N_Function_Specification + and then Nkind (Parent (N)) /= N_Parameter_Specification + then + Anon_Type := + Create_Itype + (E_Anonymous_Access_Type, Related_Nod, + Scope_Id => Scope (Defining_Unit_Name (Related_Nod))); + + else + -- For access formals, access components, and access + -- discriminants, the scope is that of the enclosing declaration, + + Anon_Type := + Create_Itype + (E_Anonymous_Access_Type, Related_Nod, + Scope_Id => Scope (Current_Scope)); + end if; + + if All_Present (N) + and then Ada_Version >= Ada_05 + then + Error_Msg_N ("ALL is not permitted for anonymous access types", N); + end if; + + -- Ada 2005 (AI-254): In case of anonymous access to subprograms + -- call the corresponding semantic routine + + if Present (Access_To_Subprogram_Definition (N)) then + Access_Subprogram_Declaration + (T_Name => Anon_Type, + T_Def => Access_To_Subprogram_Definition (N)); + + if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then + Set_Ekind + (Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type); + else + Set_Ekind + (Anon_Type, E_Anonymous_Access_Subprogram_Type); + end if; + + return Anon_Type; + end if; + + Find_Type (Subtype_Mark (N)); + Desig_Type := Entity (Subtype_Mark (N)); + + Set_Directly_Designated_Type + (Anon_Type, Desig_Type); + Set_Etype (Anon_Type, Anon_Type); + Init_Size_Align (Anon_Type); + Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type)); + + -- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs + -- from Ada 95 semantics. In Ada 2005, anonymous access must specify + -- if the null value is allowed. In Ada 95 the null value is never + -- allowed. + + if Ada_Version >= Ada_05 then + Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N)); + else + Set_Can_Never_Be_Null (Anon_Type, True); + end if; + + -- The anonymous access type is as public as the discriminated type or + -- subprogram that defines it. It is imported (for back-end purposes) + -- if the designated type is. + + Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type))); + + -- Ada 2005 (AI-50217): Propagate the attribute that indicates that the + -- designated type comes from the limited view (for back-end purposes). + + Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type)); + + -- Ada 2005 (AI-231): Propagate the access-constant attribute + + Set_Is_Access_Constant (Anon_Type, Constant_Present (N)); + + -- The context is either a subprogram declaration, object declaration, + -- or an access discriminant, in a private or a full type declaration. + -- In the case of a subprogram, if the designated type is incomplete, + -- the operation will be a primitive operation of the full type, to be + -- updated subsequently. If the type is imported through a limited_with + -- clause, the subprogram is not a primitive operation of the type + -- (which is declared elsewhere in some other scope). + + if Ekind (Desig_Type) = E_Incomplete_Type + and then not From_With_Type (Desig_Type) + and then Is_Overloadable (Current_Scope) + then + Append_Elmt (Current_Scope, Private_Dependents (Desig_Type)); + Set_Has_Delayed_Freeze (Current_Scope); + end if; + + -- Ada 2005: if the designated type is an interface that may contain + -- tasks, create a Master entity for the declaration. This must be done + -- before expansion of the full declaration, because the declaration + -- may include an expression that is an allocator, whose expansion needs + -- the proper Master for the created tasks. + + if Nkind (Related_Nod) = N_Object_Declaration + and then Expander_Active + and then Is_Interface (Desig_Type) + and then Is_Limited_Record (Desig_Type) + then + Build_Class_Wide_Master (Anon_Type); + end if; + + return Anon_Type; + end Access_Definition; + + ----------------------------------- + -- Access_Subprogram_Declaration -- + ----------------------------------- + + procedure Access_Subprogram_Declaration + (T_Name : Entity_Id; + T_Def : Node_Id) + is + Formals : constant List_Id := Parameter_Specifications (T_Def); + Formal : Entity_Id; + D_Ityp : Node_Id; + + Desig_Type : constant Entity_Id := + Create_Itype (E_Subprogram_Type, Parent (T_Def)); + + begin + -- Associate the Itype node with the inner full-type declaration + -- or subprogram spec. This is required to handle nested anonymous + -- declarations. For example: + + -- procedure P + -- (X : access procedure + -- (Y : access procedure + -- (Z : access T))) + + D_Ityp := Associated_Node_For_Itype (Desig_Type); + while Nkind (D_Ityp) /= N_Full_Type_Declaration + and then Nkind (D_Ityp) /= N_Procedure_Specification + and then Nkind (D_Ityp) /= N_Function_Specification + and then Nkind (D_Ityp) /= N_Object_Declaration + and then Nkind (D_Ityp) /= N_Object_Renaming_Declaration + and then Nkind (D_Ityp) /= N_Formal_Type_Declaration + loop + D_Ityp := Parent (D_Ityp); + pragma Assert (D_Ityp /= Empty); + end loop; + + Set_Associated_Node_For_Itype (Desig_Type, D_Ityp); + + if Nkind (D_Ityp) = N_Procedure_Specification + or else Nkind (D_Ityp) = N_Function_Specification + then + Set_Scope (Desig_Type, Scope (Defining_Unit_Name (D_Ityp))); + + elsif Nkind (D_Ityp) = N_Full_Type_Declaration + or else Nkind (D_Ityp) = N_Object_Declaration + or else Nkind (D_Ityp) = N_Object_Renaming_Declaration + or else Nkind (D_Ityp) = N_Formal_Type_Declaration + then + Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp))); + end if; + + if Nkind (T_Def) = N_Access_Function_Definition then + if Nkind (Result_Definition (T_Def)) = N_Access_Definition then + Set_Etype + (Desig_Type, + Access_Definition (T_Def, Result_Definition (T_Def))); + else + Analyze (Result_Definition (T_Def)); + Set_Etype (Desig_Type, Entity (Result_Definition (T_Def))); + end if; + + if not (Is_Type (Etype (Desig_Type))) then + Error_Msg_N + ("expect type in function specification", + Result_Definition (T_Def)); + end if; + + else + Set_Etype (Desig_Type, Standard_Void_Type); + end if; + + if Present (Formals) then + New_Scope (Desig_Type); + Process_Formals (Formals, Parent (T_Def)); + + -- A bit of a kludge here, End_Scope requires that the parent + -- pointer be set to something reasonable, but Itypes don't have + -- parent pointers. So we set it and then unset it ??? If and when + -- Itypes have proper parent pointers to their declarations, this + -- kludge can be removed. + + Set_Parent (Desig_Type, T_Name); + End_Scope; + Set_Parent (Desig_Type, Empty); + end if; + + -- The return type and/or any parameter type may be incomplete. Mark + -- the subprogram_type as depending on the incomplete type, so that + -- it can be updated when the full type declaration is seen. + + if Present (Formals) then + Formal := First_Formal (Desig_Type); + while Present (Formal) loop + if Ekind (Formal) /= E_In_Parameter + and then Nkind (T_Def) = N_Access_Function_Definition + then + Error_Msg_N ("functions can only have IN parameters", Formal); + end if; + + if Ekind (Etype (Formal)) = E_Incomplete_Type then + Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal))); + Set_Has_Delayed_Freeze (Desig_Type); + end if; + + Next_Formal (Formal); + end loop; + end if; + + if Ekind (Etype (Desig_Type)) = E_Incomplete_Type + and then not Has_Delayed_Freeze (Desig_Type) + then + Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type))); + Set_Has_Delayed_Freeze (Desig_Type); + end if; + + Check_Delayed_Subprogram (Desig_Type); + + if Protected_Present (T_Def) then + Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type); + Set_Convention (Desig_Type, Convention_Protected); + else + Set_Ekind (T_Name, E_Access_Subprogram_Type); + end if; + + Set_Etype (T_Name, T_Name); + Init_Size_Align (T_Name); + Set_Directly_Designated_Type (T_Name, Desig_Type); + + -- Ada 2005 (AI-231): Propagate the null-excluding attribute + + Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def)); + + Check_Restriction (No_Access_Subprograms, T_Def); + end Access_Subprogram_Declaration; + + ---------------------------- + -- Access_Type_Declaration -- + ---------------------------- + + procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is + S : constant Node_Id := Subtype_Indication (Def); + P : constant Node_Id := Parent (Def); + + Desig : Entity_Id; + -- Designated type + + begin + -- Check for permissible use of incomplete type + + if Nkind (S) /= N_Subtype_Indication then + Analyze (S); + + if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then + Set_Directly_Designated_Type (T, Entity (S)); + else + Set_Directly_Designated_Type (T, + Process_Subtype (S, P, T, 'P')); + end if; + + else + Set_Directly_Designated_Type (T, + Process_Subtype (S, P, T, 'P')); + end if; + + if All_Present (Def) or Constant_Present (Def) then + Set_Ekind (T, E_General_Access_Type); + else + Set_Ekind (T, E_Access_Type); + end if; + + if Base_Type (Designated_Type (T)) = T then + Error_Msg_N ("access type cannot designate itself", S); + + -- In Ada 2005, the type may have a limited view through some unit + -- in its own context, allowing the following circularity that cannot + -- be detected earlier + + elsif Is_Class_Wide_Type (Designated_Type (T)) + and then Etype (Designated_Type (T)) = T + then + Error_Msg_N + ("access type cannot designate its own classwide type", S); + + -- Clean up indication of tagged status to prevent cascaded errors + + Set_Is_Tagged_Type (T, False); + end if; + + Set_Etype (T, T); + + -- If the type has appeared already in a with_type clause, it is + -- frozen and the pointer size is already set. Else, initialize. + + if not From_With_Type (T) then + Init_Size_Align (T); + end if; + + Set_Is_Access_Constant (T, Constant_Present (Def)); + + Desig := Designated_Type (T); + + -- If designated type is an imported tagged type, indicate that the + -- access type is also imported, and therefore restricted in its use. + -- The access type may already be imported, so keep setting otherwise. + + -- Ada 2005 (AI-50217): If the non-limited view of the designated type + -- is available, use it as the designated type of the access type, so + -- that the back-end gets a usable entity. + + declare + N_Desig : Entity_Id; + + begin + if From_With_Type (Desig) + and then Ekind (Desig) /= E_Access_Type + then + Set_From_With_Type (T); + + if Ekind (Desig) = E_Incomplete_Type then + N_Desig := Non_Limited_View (Desig); + + else pragma Assert (Ekind (Desig) = E_Class_Wide_Type); + if From_With_Type (Etype (Desig)) then + N_Desig := Non_Limited_View (Etype (Desig)); + else + N_Desig := Etype (Desig); + end if; + end if; + + pragma Assert (Present (N_Desig)); + Set_Directly_Designated_Type (T, N_Desig); + end if; + end; + + -- Note that Has_Task is always false, since the access type itself + -- is not a task type. See Einfo for more description on this point. + -- Exactly the same consideration applies to Has_Controlled_Component. + + Set_Has_Task (T, False); + Set_Has_Controlled_Component (T, False); + + -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant + -- attributes + + Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def)); + Set_Is_Access_Constant (T, Constant_Present (Def)); + end Access_Type_Declaration; + + ---------------------------------- + -- Add_Interface_Tag_Components -- + ---------------------------------- + + procedure Add_Interface_Tag_Components + (N : Node_Id; + Typ : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Elmt : Elmt_Id; + Ext : Node_Id; + L : List_Id; + Last_Tag : Node_Id; + Comp : Node_Id; + + procedure Add_Tag (Iface : Entity_Id); + -- Comment required ??? + + ------------- + -- Add_Tag -- + ------------- + + procedure Add_Tag (Iface : Entity_Id) is + Decl : Node_Id; + Def : Node_Id; + Tag : Entity_Id; + Offset : Entity_Id; + + begin + pragma Assert (Is_Tagged_Type (Iface) + and then Is_Interface (Iface)); + + Def := + Make_Component_Definition (Loc, + Aliased_Present => True, + Subtype_Indication => + New_Occurrence_Of (RTE (RE_Interface_Tag), Loc)); + + Tag := Make_Defining_Identifier (Loc, New_Internal_Name ('V')); + + Decl := + Make_Component_Declaration (Loc, + Defining_Identifier => Tag, + Component_Definition => Def); + + Analyze_Component_Declaration (Decl); + + Set_Analyzed (Decl); + Set_Ekind (Tag, E_Component); + Set_Is_Limited_Record (Tag); + Set_Is_Tag (Tag); + Init_Component_Location (Tag); + + pragma Assert (Is_Frozen (Iface)); + + Set_DT_Entry_Count (Tag, + DT_Entry_Count (First_Entity (Iface))); + + if No (Last_Tag) then + Prepend (Decl, L); + else + Insert_After (Last_Tag, Decl); + end if; + + Last_Tag := Decl; + + -- If the ancestor has discriminants we need to give special support + -- to store the offset_to_top value of the secondary dispatch tables. + -- For this purpose we add a supplementary component just after the + -- field that contains the tag associated with each secondary DT. + + if Typ /= Etype (Typ) + and then Has_Discriminants (Etype (Typ)) + then + Def := + Make_Component_Definition (Loc, + Subtype_Indication => + New_Occurrence_Of (RTE (RE_Storage_Offset), Loc)); + + Offset := + Make_Defining_Identifier (Loc, New_Internal_Name ('V')); + + Decl := + Make_Component_Declaration (Loc, + Defining_Identifier => Offset, + Component_Definition => Def); + + Analyze_Component_Declaration (Decl); + + Set_Analyzed (Decl); + Set_Ekind (Offset, E_Component); + Init_Component_Location (Offset); + Insert_After (Last_Tag, Decl); + Last_Tag := Decl; + end if; + end Add_Tag; + + -- Start of processing for Add_Interface_Tag_Components + + begin + if Ekind (Typ) /= E_Record_Type + or else No (Abstract_Interfaces (Typ)) + or else Is_Empty_Elmt_List (Abstract_Interfaces (Typ)) + or else not RTE_Available (RE_Interface_Tag) + then + return; + end if; + + if Present (Abstract_Interfaces (Typ)) then + + -- Find the current last tag + + if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then + Ext := Record_Extension_Part (Type_Definition (N)); + else + pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition); + Ext := Type_Definition (N); + end if; + + Last_Tag := Empty; + + if not (Present (Component_List (Ext))) then + Set_Null_Present (Ext, False); + L := New_List; + Set_Component_List (Ext, + Make_Component_List (Loc, + Component_Items => L, + Null_Present => False)); + else + if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then + L := Component_Items + (Component_List + (Record_Extension_Part + (Type_Definition (N)))); + else + L := Component_Items + (Component_List + (Type_Definition (N))); + end if; + + -- Find the last tag component + + Comp := First (L); + while Present (Comp) loop + if Is_Tag (Defining_Identifier (Comp)) then + Last_Tag := Comp; + end if; + + Next (Comp); + end loop; + end if; + + -- At this point L references the list of components and Last_Tag + -- references the current last tag (if any). Now we add the tag + -- corresponding with all the interfaces that are not implemented + -- by the parent. + + pragma Assert (Present + (First_Elmt (Abstract_Interfaces (Typ)))); + + Elmt := First_Elmt (Abstract_Interfaces (Typ)); + while Present (Elmt) loop + Add_Tag (Node (Elmt)); + Next_Elmt (Elmt); + end loop; + end if; + end Add_Interface_Tag_Components; + + ----------------------------------- + -- Analyze_Component_Declaration -- + ----------------------------------- + + procedure Analyze_Component_Declaration (N : Node_Id) is + Id : constant Entity_Id := Defining_Identifier (N); + T : Entity_Id; + P : Entity_Id; + + function Contains_POC (Constr : Node_Id) return Boolean; + -- Determines whether a constraint uses the discriminant of a record + -- type thus becoming a per-object constraint (POC). + + function Is_Known_Limited (Typ : Entity_Id) return Boolean; + -- Check whether enclosing record is limited, to validate declaration + -- of components with limited types. + -- This seems a wrong description to me??? + -- What is Typ? For sure it can return a result without checking + -- the enclosing record (enclosing what???) + + ------------------ + -- Contains_POC -- + ------------------ + + function Contains_POC (Constr : Node_Id) return Boolean is + begin + case Nkind (Constr) is + when N_Attribute_Reference => + return Attribute_Name (Constr) = Name_Access + and + Prefix (Constr) = Scope (Entity (Prefix (Constr))); + + when N_Discriminant_Association => + return Denotes_Discriminant (Expression (Constr)); + + when N_Identifier => + return Denotes_Discriminant (Constr); + + when N_Index_Or_Discriminant_Constraint => + declare + IDC : Node_Id; + + begin + IDC := First (Constraints (Constr)); + while Present (IDC) loop + + -- One per-object constraint is sufficient + + if Contains_POC (IDC) then + return True; + end if; + + Next (IDC); + end loop; + + return False; + end; + + when N_Range => + return Denotes_Discriminant (Low_Bound (Constr)) + or else + Denotes_Discriminant (High_Bound (Constr)); + + when N_Range_Constraint => + return Denotes_Discriminant (Range_Expression (Constr)); + + when others => + return False; + + end case; + end Contains_POC; + + ---------------------- + -- Is_Known_Limited -- + ---------------------- + + function Is_Known_Limited (Typ : Entity_Id) return Boolean is + P : constant Entity_Id := Etype (Typ); + R : constant Entity_Id := Root_Type (Typ); + + begin + if Is_Limited_Record (Typ) then + return True; + + -- If the root type is limited (and not a limited interface) + -- so is the current type + + elsif Is_Limited_Record (R) + and then + (not Is_Interface (R) + or else not Is_Limited_Interface (R)) + then + return True; + + -- Else the type may have a limited interface progenitor, but a + -- limited record parent. + + elsif R /= P + and then Is_Limited_Record (P) + then + return True; + + else + return False; + end if; + end Is_Known_Limited; + + -- Start of processing for Analyze_Component_Declaration + + begin + Generate_Definition (Id); + Enter_Name (Id); + + if Present (Subtype_Indication (Component_Definition (N))) then + T := Find_Type_Of_Object + (Subtype_Indication (Component_Definition (N)), N); + + -- Ada 2005 (AI-230): Access Definition case + + else + pragma Assert (Present + (Access_Definition (Component_Definition (N)))); + + T := Access_Definition + (Related_Nod => N, + N => Access_Definition (Component_Definition (N))); + Set_Is_Local_Anonymous_Access (T); + + -- Ada 2005 (AI-254) + + if Present (Access_To_Subprogram_Definition + (Access_Definition (Component_Definition (N)))) + and then Protected_Present (Access_To_Subprogram_Definition + (Access_Definition + (Component_Definition (N)))) + then + T := Replace_Anonymous_Access_To_Protected_Subprogram (N, T); + end if; + end if; + + -- If the subtype is a constrained subtype of the enclosing record, + -- (which must have a partial view) the back-end does not properly + -- handle the recursion. Rewrite the component declaration with an + -- explicit subtype indication, which is acceptable to Gigi. We can copy + -- the tree directly because side effects have already been removed from + -- discriminant constraints. + + if Ekind (T) = E_Access_Subtype + and then Is_Entity_Name (Subtype_Indication (Component_Definition (N))) + and then Comes_From_Source (T) + and then Nkind (Parent (T)) = N_Subtype_Declaration + and then Etype (Directly_Designated_Type (T)) = Current_Scope + then + Rewrite + (Subtype_Indication (Component_Definition (N)), + New_Copy_Tree (Subtype_Indication (Parent (T)))); + T := Find_Type_Of_Object + (Subtype_Indication (Component_Definition (N)), N); + end if; + + -- If the component declaration includes a default expression, then we + -- check that the component is not of a limited type (RM 3.7(5)), + -- and do the special preanalysis of the expression (see section on + -- "Handling of Default and Per-Object Expressions" in the spec of + -- package Sem). + + if Present (Expression (N)) then + Analyze_Per_Use_Expression (Expression (N), T); + Check_Initialization (T, Expression (N)); + + if Ada_Version >= Ada_05 + and then Is_Access_Type (T) + and then Ekind (T) = E_Anonymous_Access_Type + then + -- Check RM 3.9.2(9): "if the expected type for an expression is + -- an anonymous access-to-specific tagged type, then the object + -- designated by the expression shall not be dynamically tagged + -- unless it is a controlling operand in a call on a dispatching + -- operation" + + if Is_Tagged_Type (Directly_Designated_Type (T)) + and then + Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type + and then + Ekind (Directly_Designated_Type (Etype (Expression (N)))) = + E_Class_Wide_Type + then + Error_Msg_N + ("access to specific tagged type required ('R'M 3.9.2(9))", + Expression (N)); + end if; + + -- (Ada 2005: AI-230): Accessibility check for anonymous + -- components + + if Type_Access_Level (Etype (Expression (N))) > + Type_Access_Level (T) + then + Error_Msg_N + ("expression has deeper access level than component " & + "('R'M 3.10.2 (12.2))", Expression (N)); + end if; + end if; + end if; + + -- The parent type may be a private view with unknown discriminants, + -- and thus unconstrained. Regular components must be constrained. + + if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then + if Is_Class_Wide_Type (T) then + Error_Msg_N + ("class-wide subtype with unknown discriminants" & + " in component declaration", + Subtype_Indication (Component_Definition (N))); + else + Error_Msg_N + ("unconstrained subtype in component declaration", + Subtype_Indication (Component_Definition (N))); + end if; + + -- Components cannot be abstract, except for the special case of + -- the _Parent field (case of extending an abstract tagged type) + + elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then + Error_Msg_N ("type of a component cannot be abstract", N); + end if; + + Set_Etype (Id, T); + Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N))); + + -- The component declaration may have a per-object constraint, set + -- the appropriate flag in the defining identifier of the subtype. + + if Present (Subtype_Indication (Component_Definition (N))) then + declare + Sindic : constant Node_Id := + Subtype_Indication (Component_Definition (N)); + + begin + if Nkind (Sindic) = N_Subtype_Indication + and then Present (Constraint (Sindic)) + and then Contains_POC (Constraint (Sindic)) + then + Set_Has_Per_Object_Constraint (Id); + end if; + end; + end if; + + -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry + -- out some static checks. + + if Ada_Version >= Ada_05 + and then Can_Never_Be_Null (T) + then + Null_Exclusion_Static_Checks (N); + end if; + + -- If this component is private (or depends on a private type), flag the + -- record type to indicate that some operations are not available. + + P := Private_Component (T); + + if Present (P) then + + -- Check for circular definitions + + if P = Any_Type then + Set_Etype (Id, Any_Type); + + -- There is a gap in the visibility of operations only if the + -- component type is not defined in the scope of the record type. + + elsif Scope (P) = Scope (Current_Scope) then + null; + + elsif Is_Limited_Type (P) then + Set_Is_Limited_Composite (Current_Scope); + + else + Set_Is_Private_Composite (Current_Scope); + end if; + end if; + + if P /= Any_Type + and then Is_Limited_Type (T) + and then Chars (Id) /= Name_uParent + and then Is_Tagged_Type (Current_Scope) + then + if Is_Derived_Type (Current_Scope) + and then not Is_Known_Limited (Current_Scope) + then + Error_Msg_N + ("extension of nonlimited type cannot have limited components", + N); + + if Is_Interface (Root_Type (Current_Scope)) then + Error_Msg_N + ("\limitedness is not inherited from limited interface", N); + Error_Msg_N + ("\add LIMITED to type indication", N); + end if; + + Explain_Limited_Type (T, N); + Set_Etype (Id, Any_Type); + Set_Is_Limited_Composite (Current_Scope, False); + + elsif not Is_Derived_Type (Current_Scope) + and then not Is_Limited_Record (Current_Scope) + and then not Is_Concurrent_Type (Current_Scope) + then + Error_Msg_N + ("nonlimited tagged type cannot have limited components", N); + Explain_Limited_Type (T, N); + Set_Etype (Id, Any_Type); + Set_Is_Limited_Composite (Current_Scope, False); + end if; + end if; + + Set_Original_Record_Component (Id, Id); + end Analyze_Component_Declaration; + + -------------------------- + -- Analyze_Declarations -- + -------------------------- + + procedure Analyze_Declarations (L : List_Id) is + D : Node_Id; + Next_Node : Node_Id; + Freeze_From : Entity_Id := Empty; + + procedure Adjust_D; + -- Adjust D not to include implicit label declarations, since these + -- have strange Sloc values that result in elaboration check problems. + -- (They have the sloc of the label as found in the source, and that + -- is ahead of the current declarative part). + + -------------- + -- Adjust_D -- + -------------- + + procedure Adjust_D is + begin + while Present (Prev (D)) + and then Nkind (D) = N_Implicit_Label_Declaration + loop + Prev (D); + end loop; + end Adjust_D; + + -- Start of processing for Analyze_Declarations + + begin + D := First (L); + while Present (D) loop + + -- Complete analysis of declaration + + Analyze (D); + Next_Node := Next (D); + + if No (Freeze_From) then + Freeze_From := First_Entity (Current_Scope); + end if; + + -- At the end of a declarative part, freeze remaining entities + -- declared in it. The end of the visible declarations of package + -- specification is not the end of a declarative part if private + -- declarations are present. The end of a package declaration is a + -- freezing point only if it a library package. A task definition or + -- protected type definition is not a freeze point either. Finally, + -- we do not freeze entities in generic scopes, because there is no + -- code generated for them and freeze nodes will be generated for + -- the instance. + + -- The end of a package instantiation is not a freeze point, but + -- for now we make it one, because the generic body is inserted + -- (currently) immediately after. Generic instantiations will not + -- be a freeze point once delayed freezing of bodies is implemented. + -- (This is needed in any case for early instantiations ???). + + if No (Next_Node) then + if Nkind (Parent (L)) = N_Component_List + or else Nkind (Parent (L)) = N_Task_Definition + or else Nkind (Parent (L)) = N_Protected_Definition + then + null; + + elsif Nkind (Parent (L)) /= N_Package_Specification then + if Nkind (Parent (L)) = N_Package_Body then + Freeze_From := First_Entity (Current_Scope); + end if; + + Adjust_D; + Freeze_All (Freeze_From, D); + Freeze_From := Last_Entity (Current_Scope); + + elsif Scope (Current_Scope) /= Standard_Standard + and then not Is_Child_Unit (Current_Scope) + and then No (Generic_Parent (Parent (L))) + then + null; + + elsif L /= Visible_Declarations (Parent (L)) + or else No (Private_Declarations (Parent (L))) + or else Is_Empty_List (Private_Declarations (Parent (L))) + then + Adjust_D; + Freeze_All (Freeze_From, D); + Freeze_From := Last_Entity (Current_Scope); + end if; + + -- If next node is a body then freeze all types before the body. + -- An exception occurs for expander generated bodies, which can + -- be recognized by their already being analyzed. The expander + -- ensures that all types needed by these bodies have been frozen + -- but it is not necessary to freeze all types (and would be wrong + -- since it would not correspond to an RM defined freeze point). + + elsif not Analyzed (Next_Node) + and then (Nkind (Next_Node) = N_Subprogram_Body + or else Nkind (Next_Node) = N_Entry_Body + or else Nkind (Next_Node) = N_Package_Body + or else Nkind (Next_Node) = N_Protected_Body + or else Nkind (Next_Node) = N_Task_Body + or else Nkind (Next_Node) in N_Body_Stub) + then + Adjust_D; + Freeze_All (Freeze_From, D); + Freeze_From := Last_Entity (Current_Scope); + end if; + + D := Next_Node; + end loop; + end Analyze_Declarations; + + ---------------------------------- + -- Analyze_Incomplete_Type_Decl -- + ---------------------------------- + + procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is + F : constant Boolean := Is_Pure (Current_Scope); + T : Entity_Id; + + begin + Generate_Definition (Defining_Identifier (N)); + + -- Process an incomplete declaration. The identifier must not have been + -- declared already in the scope. However, an incomplete declaration may + -- appear in the private part of a package, for a private type that has + -- already been declared. + + -- In this case, the discriminants (if any) must match + + T := Find_Type_Name (N); + + Set_Ekind (T, E_Incomplete_Type); + Init_Size_Align (T); + Set_Is_First_Subtype (T, True); + Set_Etype (T, T); + + -- Ada 2005 (AI-326): Minimum decoration to give support to tagged + -- incomplete types. + + if Tagged_Present (N) then + Set_Is_Tagged_Type (T); + Make_Class_Wide_Type (T); + Set_Primitive_Operations (T, New_Elmt_List); + end if; + + New_Scope (T); + + Set_Stored_Constraint (T, No_Elist); + + if Present (Discriminant_Specifications (N)) then + Process_Discriminants (N); + end if; + + End_Scope; + + -- If the type has discriminants, non-trivial subtypes may be be + -- declared before the full view of the type. The full views of those + -- subtypes will be built after the full view of the type. + + Set_Private_Dependents (T, New_Elmt_List); + Set_Is_Pure (T, F); + end Analyze_Incomplete_Type_Decl; + + ----------------------------------- + -- Analyze_Interface_Declaration -- + ----------------------------------- + + procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is + begin + Set_Is_Tagged_Type (T); + + Set_Is_Limited_Record (T, Limited_Present (Def) + or else Task_Present (Def) + or else Protected_Present (Def) + or else Synchronized_Present (Def)); + + -- Type is abstract if full declaration carries keyword, or if + -- previous partial view did. + + Set_Is_Abstract (T); + Set_Is_Interface (T); + + Set_Is_Limited_Interface (T, Limited_Present (Def)); + Set_Is_Protected_Interface (T, Protected_Present (Def)); + Set_Is_Synchronized_Interface (T, Synchronized_Present (Def)); + Set_Is_Task_Interface (T, Task_Present (Def)); + Set_Abstract_Interfaces (T, New_Elmt_List); + Set_Primitive_Operations (T, New_Elmt_List); + end Analyze_Interface_Declaration; + + ----------------------------- + -- Analyze_Itype_Reference -- + ----------------------------- + + -- Nothing to do. This node is placed in the tree only for the benefit of + -- back end processing, and has no effect on the semantic processing. + + procedure Analyze_Itype_Reference (N : Node_Id) is + begin + pragma Assert (Is_Itype (Itype (N))); + null; + end Analyze_Itype_Reference; + + -------------------------------- + -- Analyze_Number_Declaration -- + -------------------------------- + + procedure Analyze_Number_Declaration (N : Node_Id) is + Id : constant Entity_Id := Defining_Identifier (N); + E : constant Node_Id := Expression (N); + T : Entity_Id; + Index : Interp_Index; + It : Interp; + + begin + Generate_Definition (Id); + Enter_Name (Id); + + -- This is an optimization of a common case of an integer literal + + if Nkind (E) = N_Integer_Literal then + Set_Is_Static_Expression (E, True); + Set_Etype (E, Universal_Integer); + + Set_Etype (Id, Universal_Integer); + Set_Ekind (Id, E_Named_Integer); + Set_Is_Frozen (Id, True); + return; + end if; + + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + + -- Process expression, replacing error by integer zero, to avoid + -- cascaded errors or aborts further along in the processing + + -- Replace Error by integer zero, which seems least likely to + -- cause cascaded errors. + + if E = Error then + Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0)); + Set_Error_Posted (E); + end if; + + Analyze (E); + + -- Verify that the expression is static and numeric. If + -- the expression is overloaded, we apply the preference + -- rule that favors root numeric types. + + if not Is_Overloaded (E) then + T := Etype (E); + + else + T := Any_Type; + + Get_First_Interp (E, Index, It); + while Present (It.Typ) loop + if (Is_Integer_Type (It.Typ) + or else Is_Real_Type (It.Typ)) + and then (Scope (Base_Type (It.Typ))) = Standard_Standard + then + if T = Any_Type then + T := It.Typ; + + elsif It.Typ = Universal_Real + or else It.Typ = Universal_Integer + then + -- Choose universal interpretation over any other + + T := It.Typ; + exit; + end if; + end if; + + Get_Next_Interp (Index, It); + end loop; + end if; + + if Is_Integer_Type (T) then + Resolve (E, T); + Set_Etype (Id, Universal_Integer); + Set_Ekind (Id, E_Named_Integer); + + elsif Is_Real_Type (T) then + + -- Because the real value is converted to universal_real, this is a + -- legal context for a universal fixed expression. + + if T = Universal_Fixed then + declare + Loc : constant Source_Ptr := Sloc (N); + Conv : constant Node_Id := Make_Type_Conversion (Loc, + Subtype_Mark => + New_Occurrence_Of (Universal_Real, Loc), + Expression => Relocate_Node (E)); + + begin + Rewrite (E, Conv); + Analyze (E); + end; + + elsif T = Any_Fixed then + Error_Msg_N ("illegal context for mixed mode operation", E); + + -- Expression is of the form : universal_fixed * integer. Try to + -- resolve as universal_real. + + T := Universal_Real; + Set_Etype (E, T); + end if; + + Resolve (E, T); + Set_Etype (Id, Universal_Real); + Set_Ekind (Id, E_Named_Real); + + else + Wrong_Type (E, Any_Numeric); + Resolve (E, T); + + Set_Etype (Id, T); + Set_Ekind (Id, E_Constant); + Set_Never_Set_In_Source (Id, True); + Set_Is_True_Constant (Id, True); + return; + end if; + + if Nkind (E) = N_Integer_Literal + or else Nkind (E) = N_Real_Literal + then + Set_Etype (E, Etype (Id)); + end if; + + if not Is_OK_Static_Expression (E) then + Flag_Non_Static_Expr + ("non-static expression used in number declaration!", E); + Rewrite (E, Make_Integer_Literal (Sloc (N), 1)); + Set_Etype (E, Any_Type); + end if; + end Analyze_Number_Declaration; + + -------------------------------- + -- Analyze_Object_Declaration -- + -------------------------------- + + procedure Analyze_Object_Declaration (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Id : constant Entity_Id := Defining_Identifier (N); + T : Entity_Id; + Act_T : Entity_Id; + + E : Node_Id := Expression (N); + -- E is set to Expression (N) throughout this routine. When + -- Expression (N) is modified, E is changed accordingly. + + Prev_Entity : Entity_Id := Empty; + + function Build_Default_Subtype return Entity_Id; + -- If the object is limited or aliased, and if the type is unconstrained + -- and there is no expression, the discriminants cannot be modified and + -- the subtype of the object is constrained by the defaults, so it is + -- worthwhile building the corresponding subtype. + + function Count_Tasks (T : Entity_Id) return Uint; + -- This function is called when a library level object of type is + -- declared. It's function is to count the static number of tasks + -- declared within the type (it is only called if Has_Tasks is set for + -- T). As a side effect, if an array of tasks with non-static bounds or + -- a variant record type is encountered, Check_Restrictions is called + -- indicating the count is unknown. + + --------------------------- + -- Build_Default_Subtype -- + --------------------------- + + function Build_Default_Subtype return Entity_Id is + Constraints : constant List_Id := New_List; + Act : Entity_Id; + Decl : Node_Id; + Disc : Entity_Id; + + begin + Disc := First_Discriminant (T); + + if No (Discriminant_Default_Value (Disc)) then + return T; -- previous error. + end if; + + Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S')); + while Present (Disc) loop + Append ( + New_Copy_Tree ( + Discriminant_Default_Value (Disc)), Constraints); + Next_Discriminant (Disc); + end loop; + + Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Act, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Occurrence_Of (T, Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint + (Loc, Constraints))); + + Insert_Before (N, Decl); + Analyze (Decl); + return Act; + end Build_Default_Subtype; + + ----------------- + -- Count_Tasks -- + ----------------- + + function Count_Tasks (T : Entity_Id) return Uint is + C : Entity_Id; + X : Node_Id; + V : Uint; + + begin + if Is_Task_Type (T) then + return Uint_1; + + elsif Is_Record_Type (T) then + if Has_Discriminants (T) then + Check_Restriction (Max_Tasks, N); + return Uint_0; + + else + V := Uint_0; + C := First_Component (T); + while Present (C) loop + V := V + Count_Tasks (Etype (C)); + Next_Component (C); + end loop; + + return V; + end if; + + elsif Is_Array_Type (T) then + X := First_Index (T); + V := Count_Tasks (Component_Type (T)); + while Present (X) loop + C := Etype (X); + + if not Is_Static_Subtype (C) then + Check_Restriction (Max_Tasks, N); + return Uint_0; + else + V := V * (UI_Max (Uint_0, + Expr_Value (Type_High_Bound (C)) - + Expr_Value (Type_Low_Bound (C)) + Uint_1)); + end if; + + Next_Index (X); + end loop; + + return V; + + else + return Uint_0; + end if; + end Count_Tasks; + + -- Start of processing for Analyze_Object_Declaration + + begin + -- There are three kinds of implicit types generated by an + -- object declaration: + + -- 1. Those for generated by the original Object Definition + + -- 2. Those generated by the Expression + + -- 3. Those used to constrained the Object Definition with the + -- expression constraints when it is unconstrained + + -- They must be generated in this order to avoid order of elaboration + -- issues. Thus the first step (after entering the name) is to analyze + -- the object definition. + + if Constant_Present (N) then + Prev_Entity := Current_Entity_In_Scope (Id); + + -- If homograph is an implicit subprogram, it is overridden by the + -- current declaration. + + if Present (Prev_Entity) + and then Is_Overloadable (Prev_Entity) + and then Is_Inherited_Operation (Prev_Entity) + then + Prev_Entity := Empty; + end if; + end if; + + if Present (Prev_Entity) then + Constant_Redeclaration (Id, N, T); + + Generate_Reference (Prev_Entity, Id, 'c'); + Set_Completion_Referenced (Id); + + if Error_Posted (N) then + + -- Type mismatch or illegal redeclaration, Do not analyze + -- expression to avoid cascaded errors. + + T := Find_Type_Of_Object (Object_Definition (N), N); + Set_Etype (Id, T); + Set_Ekind (Id, E_Variable); + return; + end if; + + -- In the normal case, enter identifier at the start to catch premature + -- usage in the initialization expression. + + else + Generate_Definition (Id); + Enter_Name (Id); + + T := Find_Type_Of_Object (Object_Definition (N), N); + + if Error_Posted (Id) then + Set_Etype (Id, T); + Set_Ekind (Id, E_Variable); + return; + end if; + end if; + + -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry + -- out some static checks + + if Ada_Version >= Ada_05 + and then Can_Never_Be_Null (T) + then + -- In case of aggregates we must also take care of the correct + -- initialization of nested aggregates bug this is done at the + -- point of the analysis of the aggregate (see sem_aggr.adb) + + if Present (Expression (N)) + and then Nkind (Expression (N)) = N_Aggregate + then + null; + + else + declare + Save_Typ : constant Entity_Id := Etype (Id); + begin + Set_Etype (Id, T); -- Temp. decoration for static checks + Null_Exclusion_Static_Checks (N); + Set_Etype (Id, Save_Typ); + end; + end if; + end if; + + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + + -- If deferred constant, make sure context is appropriate. We detect + -- a deferred constant as a constant declaration with no expression. + -- A deferred constant can appear in a package body if its completion + -- is by means of an interface pragma. + + if Constant_Present (N) + and then No (E) + then + if not Is_Package_Or_Generic_Package (Current_Scope) then + Error_Msg_N + ("invalid context for deferred constant declaration ('R'M 7.4)", + N); + Error_Msg_N + ("\declaration requires an initialization expression", + N); + Set_Constant_Present (N, False); + + -- In Ada 83, deferred constant must be of private type + + elsif not Is_Private_Type (T) then + if Ada_Version = Ada_83 and then Comes_From_Source (N) then + Error_Msg_N + ("(Ada 83) deferred constant must be private type", N); + end if; + end if; + + -- If not a deferred constant, then object declaration freezes its type + + else + Check_Fully_Declared (T, N); + Freeze_Before (N, T); + end if; + + -- If the object was created by a constrained array definition, then + -- set the link in both the anonymous base type and anonymous subtype + -- that are built to represent the array type to point to the object. + + if Nkind (Object_Definition (Declaration_Node (Id))) = + N_Constrained_Array_Definition + then + Set_Related_Array_Object (T, Id); + Set_Related_Array_Object (Base_Type (T), Id); + end if; + + -- Special checks for protected objects not at library level + + if Is_Protected_Type (T) + and then not Is_Library_Level_Entity (Id) + then + Check_Restriction (No_Local_Protected_Objects, Id); + + -- Protected objects with interrupt handlers must be at library level + + -- Ada 2005: this test is not needed (and the corresponding clause + -- in the RM is removed) because accessibility checks are sufficient + -- to make handlers not at the library level illegal. + + if Has_Interrupt_Handler (T) + and then Ada_Version < Ada_05 + then + Error_Msg_N + ("interrupt object can only be declared at library level", Id); + end if; + end if; + + -- The actual subtype of the object is the nominal subtype, unless + -- the nominal one is unconstrained and obtained from the expression. + + Act_T := T; + + -- Process initialization expression if present and not in error + + if Present (E) and then E /= Error then + Analyze (E); + + -- In case of errors detected in the analysis of the expression, + -- decorate it with the expected type to avoid cascade errors + + if No (Etype (E)) then + Set_Etype (E, T); + end if; + + -- If an initialization expression is present, then we set the + -- Is_True_Constant flag. It will be reset if this is a variable + -- and it is indeed modified. + + Set_Is_True_Constant (Id, True); + + -- If we are analyzing a constant declaration, set its completion + -- flag after analyzing the expression. + + if Constant_Present (N) then + Set_Has_Completion (Id); + end if; + + if not Assignment_OK (N) then + Check_Initialization (T, E); + end if; + + Set_Etype (Id, T); -- may be overridden later on + Resolve (E, T); + Check_Unset_Reference (E); + + if Compile_Time_Known_Value (E) then + Set_Current_Value (Id, E); + end if; + + -- Check incorrect use of dynamically tagged expressions. Note + -- the use of Is_Tagged_Type (T) which seems redundant but is in + -- fact important to avoid spurious errors due to expanded code + -- for dispatching functions over an anonymous access type + + if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E)) + and then Is_Tagged_Type (T) + and then not Is_Class_Wide_Type (T) + then + Error_Msg_N ("dynamically tagged expression not allowed!", E); + end if; + + Apply_Scalar_Range_Check (E, T); + Apply_Static_Length_Check (E, T); + end if; + + -- If the No_Streams restriction is set, check that the type of the + -- object is not, and does not contain, any subtype derived from + -- Ada.Streams.Root_Stream_Type. Note that we guard the call to + -- Has_Stream just for efficiency reasons. There is no point in + -- spending time on a Has_Stream check if the restriction is not set. + + if Restrictions.Set (No_Streams) then + if Has_Stream (T) then + Check_Restriction (No_Streams, N); + end if; + end if; + + -- Abstract type is never permitted for a variable or constant. + -- Note: we inhibit this check for objects that do not come from + -- source because there is at least one case (the expansion of + -- x'class'input where x is abstract) where we legitimately + -- generate an abstract object. + + if Is_Abstract (T) and then Comes_From_Source (N) then + Error_Msg_N ("type of object cannot be abstract", + Object_Definition (N)); + + if Is_CPP_Class (T) then + Error_Msg_NE ("\} may need a cpp_constructor", + Object_Definition (N), T); + end if; + + -- Case of unconstrained type + + elsif Is_Indefinite_Subtype (T) then + + -- Nothing to do in deferred constant case + + if Constant_Present (N) and then No (E) then + null; + + -- Case of no initialization present + + elsif No (E) then + if No_Initialization (N) then + null; + + elsif Is_Class_Wide_Type (T) then + Error_Msg_N + ("initialization required in class-wide declaration ", N); + + else + Error_Msg_N + ("unconstrained subtype not allowed (need initialization)", + Object_Definition (N)); + end if; + + -- Case of initialization present but in error. Set initial + -- expression as absent (but do not make above complaints) + + elsif E = Error then + Set_Expression (N, Empty); + E := Empty; + + -- Case of initialization present + + else + -- Not allowed in Ada 83 + + if not Constant_Present (N) then + if Ada_Version = Ada_83 + and then Comes_From_Source (Object_Definition (N)) + then + Error_Msg_N + ("(Ada 83) unconstrained variable not allowed", + Object_Definition (N)); + end if; + end if; + + -- Now we constrain the variable from the initializing expression + + -- If the expression is an aggregate, it has been expanded into + -- individual assignments. Retrieve the actual type from the + -- expanded construct. + + if Is_Array_Type (T) + and then No_Initialization (N) + and then Nkind (Original_Node (E)) = N_Aggregate + then + Act_T := Etype (E); + + else + Expand_Subtype_From_Expr (N, T, Object_Definition (N), E); + Act_T := Find_Type_Of_Object (Object_Definition (N), N); + end if; + + Set_Is_Constr_Subt_For_U_Nominal (Act_T); + + if Aliased_Present (N) then + Set_Is_Constr_Subt_For_UN_Aliased (Act_T); + end if; + + Freeze_Before (N, Act_T); + Freeze_Before (N, T); + end if; + + elsif Is_Array_Type (T) + and then No_Initialization (N) + and then Nkind (Original_Node (E)) = N_Aggregate + then + if not Is_Entity_Name (Object_Definition (N)) then + Act_T := Etype (E); + Check_Compile_Time_Size (Act_T); + + if Aliased_Present (N) then + Set_Is_Constr_Subt_For_UN_Aliased (Act_T); + end if; + end if; + + -- When the given object definition and the aggregate are specified + -- independently, and their lengths might differ do a length check. + -- This cannot happen if the aggregate is of the form (others =>...) + + if not Is_Constrained (T) then + null; + + elsif Nkind (E) = N_Raise_Constraint_Error then + + -- Aggregate is statically illegal. Place back in declaration + + Set_Expression (N, E); + Set_No_Initialization (N, False); + + elsif T = Etype (E) then + null; + + elsif Nkind (E) = N_Aggregate + and then Present (Component_Associations (E)) + and then Present (Choices (First (Component_Associations (E)))) + and then Nkind (First + (Choices (First (Component_Associations (E))))) = N_Others_Choice + then + null; + + else + Apply_Length_Check (E, T); + end if; + + elsif (Is_Limited_Record (T) + or else Is_Concurrent_Type (T)) + and then not Is_Constrained (T) + and then Has_Discriminants (T) + then + if No (E) then + Act_T := Build_Default_Subtype; + else + -- Ada 2005: a limited object may be initialized by means of an + -- aggregate. If the type has default discriminants it has an + -- unconstrained nominal type, Its actual subtype will be obtained + -- from the aggregate, and not from the default discriminants. + + Act_T := Etype (E); + end if; + + Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc)); + + elsif Present (Underlying_Type (T)) + and then not Is_Constrained (Underlying_Type (T)) + and then Has_Discriminants (Underlying_Type (T)) + and then Nkind (E) = N_Function_Call + and then Constant_Present (N) + then + -- The back-end has problems with constants of a discriminated type + -- with defaults, if the initial value is a function call. We + -- generate an intermediate temporary for the result of the call. + -- It is unclear why this should make it acceptable to gcc. ??? + + Remove_Side_Effects (E); + end if; + + if T = Standard_Wide_Character or else T = Standard_Wide_Wide_Character + or else Root_Type (T) = Standard_Wide_String + or else Root_Type (T) = Standard_Wide_Wide_String + then + Check_Restriction (No_Wide_Characters, Object_Definition (N)); + end if; + + -- Now establish the proper kind and type of the object + + if Constant_Present (N) then + Set_Ekind (Id, E_Constant); + Set_Never_Set_In_Source (Id, True); + Set_Is_True_Constant (Id, True); + + else + Set_Ekind (Id, E_Variable); + + -- A variable is set as shared passive if it appears in a shared + -- passive package, and is at the outer level. This is not done + -- for entities generated during expansion, because those are + -- always manipulated locally. + + if Is_Shared_Passive (Current_Scope) + and then Is_Library_Level_Entity (Id) + and then Comes_From_Source (Id) + then + Set_Is_Shared_Passive (Id); + Check_Shared_Var (Id, T, N); + end if; + + -- Case of no initializing expression present. If the type is not + -- fully initialized, then we set Never_Set_In_Source, since this + -- is a case of a potentially uninitialized object. Note that we + -- do not consider access variables to be fully initialized for + -- this purpose, since it still seems dubious if someone declares + + -- Note that we only do this for source declarations. If the object + -- is declared by a generated declaration, we assume that it is not + -- appropriate to generate warnings in that case. + + if No (E) then + if (Is_Access_Type (T) + or else not Is_Fully_Initialized_Type (T)) + and then Comes_From_Source (N) + then + Set_Never_Set_In_Source (Id); + end if; + end if; + end if; + + Init_Alignment (Id); + Init_Esize (Id); + + if Aliased_Present (N) then + Set_Is_Aliased (Id); + + if No (E) + and then Is_Record_Type (T) + and then not Is_Constrained (T) + and then Has_Discriminants (T) + then + Set_Actual_Subtype (Id, Build_Default_Subtype); + end if; + end if; + + Set_Etype (Id, Act_T); + + if Has_Controlled_Component (Etype (Id)) + or else Is_Controlled (Etype (Id)) + then + if not Is_Library_Level_Entity (Id) then + Check_Restriction (No_Nested_Finalization, N); + else + Validate_Controlled_Object (Id); + end if; + + -- Generate a warning when an initialization causes an obvious ABE + -- violation. If the init expression is a simple aggregate there + -- shouldn't be any initialize/adjust call generated. This will be + -- true as soon as aggregates are built in place when possible. + + -- ??? at the moment we do not generate warnings for temporaries + -- created for those aggregates although Program_Error might be + -- generated if compiled with -gnato. + + if Is_Controlled (Etype (Id)) + and then Comes_From_Source (Id) + then + declare + BT : constant Entity_Id := Base_Type (Etype (Id)); + + Implicit_Call : Entity_Id; + pragma Warnings (Off, Implicit_Call); + -- ??? what is this for (never referenced!) + + function Is_Aggr (N : Node_Id) return Boolean; + -- Check that N is an aggregate + + ------------- + -- Is_Aggr -- + ------------- + + function Is_Aggr (N : Node_Id) return Boolean is + begin + case Nkind (Original_Node (N)) is + when N_Aggregate | N_Extension_Aggregate => + return True; + + when N_Qualified_Expression | + N_Type_Conversion | + N_Unchecked_Type_Conversion => + return Is_Aggr (Expression (Original_Node (N))); + + when others => + return False; + end case; + end Is_Aggr; + + begin + -- If no underlying type, we already are in an error situation. + -- Do not try to add a warning since we do not have access to + -- prim-op list. + + if No (Underlying_Type (BT)) then + Implicit_Call := Empty; + + -- A generic type does not have usable primitive operators. + -- Initialization calls are built for instances. + + elsif Is_Generic_Type (BT) then + Implicit_Call := Empty; + + -- If the init expression is not an aggregate, an adjust call + -- will be generated + + elsif Present (E) and then not Is_Aggr (E) then + Implicit_Call := Find_Prim_Op (BT, Name_Adjust); + + -- If no init expression and we are not in the deferred + -- constant case, an Initialize call will be generated + + elsif No (E) and then not Constant_Present (N) then + Implicit_Call := Find_Prim_Op (BT, Name_Initialize); + + else + Implicit_Call := Empty; + end if; + end; + end if; + end if; + + if Has_Task (Etype (Id)) then + Check_Restriction (No_Tasking, N); + + if Is_Library_Level_Entity (Id) then + Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id))); + else + Check_Restriction (Max_Tasks, N); + Check_Restriction (No_Task_Hierarchy, N); + Check_Potentially_Blocking_Operation (N); + end if; + + -- A rather specialized test. If we see two tasks being declared + -- of the same type in the same object declaration, and the task + -- has an entry with an address clause, we know that program error + -- will be raised at run-time since we can't have two tasks with + -- entries at the same address. + + if Is_Task_Type (Etype (Id)) and then More_Ids (N) then + declare + E : Entity_Id; + + begin + E := First_Entity (Etype (Id)); + while Present (E) loop + if Ekind (E) = E_Entry + and then Present (Get_Attribute_Definition_Clause + (E, Attribute_Address)) + then + Error_Msg_N + ("?more than one task with same entry address", N); + Error_Msg_N + ("\?Program_Error will be raised at run time", N); + Insert_Action (N, + Make_Raise_Program_Error (Loc, + Reason => PE_Duplicated_Entry_Address)); + exit; + end if; + + Next_Entity (E); + end loop; + end; + end if; + end if; + + -- Some simple constant-propagation: if the expression is a constant + -- string initialized with a literal, share the literal. This avoids + -- a run-time copy. + + if Present (E) + and then Is_Entity_Name (E) + and then Ekind (Entity (E)) = E_Constant + and then Base_Type (Etype (E)) = Standard_String + then + declare + Val : constant Node_Id := Constant_Value (Entity (E)); + begin + if Present (Val) + and then Nkind (Val) = N_String_Literal + then + Rewrite (E, New_Copy (Val)); + end if; + end; + end if; + + -- Another optimization: if the nominal subtype is unconstrained and + -- the expression is a function call that returns an unconstrained + -- type, rewrite the declaration as a renaming of the result of the + -- call. The exceptions below are cases where the copy is expected, + -- either by the back end (Aliased case) or by the semantics, as for + -- initializing controlled types or copying tags for classwide types. + + if Present (E) + and then Nkind (E) = N_Explicit_Dereference + and then Nkind (Original_Node (E)) = N_Function_Call + and then not Is_Library_Level_Entity (Id) + and then not Is_Constrained (Underlying_Type (T)) + and then not Is_Aliased (Id) + and then not Is_Class_Wide_Type (T) + and then not Is_Controlled (T) + and then not Has_Controlled_Component (Base_Type (T)) + and then Expander_Active + then + Rewrite (N, + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => Id, + Access_Definition => Empty, + Subtype_Mark => New_Occurrence_Of + (Base_Type (Etype (Id)), Loc), + Name => E)); + + Set_Renamed_Object (Id, E); + + -- Force generation of debugging information for the constant and for + -- the renamed function call. + + Set_Needs_Debug_Info (Id); + Set_Needs_Debug_Info (Entity (Prefix (E))); + end if; + + if Present (Prev_Entity) + and then Is_Frozen (Prev_Entity) + and then not Error_Posted (Id) + then + Error_Msg_N ("full constant declaration appears too late", N); + end if; + + Check_Eliminated (Id); + end Analyze_Object_Declaration; + + --------------------------- + -- Analyze_Others_Choice -- + --------------------------- + + -- Nothing to do for the others choice node itself, the semantic analysis + -- of the others choice will occur as part of the processing of the parent + + procedure Analyze_Others_Choice (N : Node_Id) is + pragma Warnings (Off, N); + begin + null; + end Analyze_Others_Choice; + + -------------------------------- + -- Analyze_Per_Use_Expression -- + -------------------------------- + + procedure Analyze_Per_Use_Expression (N : Node_Id; T : Entity_Id) is + Save_In_Default_Expression : constant Boolean := In_Default_Expression; + begin + In_Default_Expression := True; + Pre_Analyze_And_Resolve (N, T); + In_Default_Expression := Save_In_Default_Expression; + end Analyze_Per_Use_Expression; + + ------------------------------------------- + -- Analyze_Private_Extension_Declaration -- + ------------------------------------------- + + procedure Analyze_Private_Extension_Declaration (N : Node_Id) is + T : constant Entity_Id := Defining_Identifier (N); + Indic : constant Node_Id := Subtype_Indication (N); + Parent_Type : Entity_Id; + Parent_Base : Entity_Id; + + begin + -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces + + if Is_Non_Empty_List (Interface_List (N)) then + declare + Intf : Node_Id; + T : Entity_Id; + + begin + Intf := First (Interface_List (N)); + while Present (Intf) loop + T := Find_Type_Of_Subtype_Indic (Intf); + + if not Is_Interface (T) then + Error_Msg_NE ("(Ada 2005) & must be an interface", Intf, T); + end if; + + Next (Intf); + end loop; + end; + end if; + + Generate_Definition (T); + Enter_Name (T); + + Parent_Type := Find_Type_Of_Subtype_Indic (Indic); + Parent_Base := Base_Type (Parent_Type); + + if Parent_Type = Any_Type + or else Etype (Parent_Type) = Any_Type + then + Set_Ekind (T, Ekind (Parent_Type)); + Set_Etype (T, Any_Type); + return; + + elsif not Is_Tagged_Type (Parent_Type) then + Error_Msg_N + ("parent of type extension must be a tagged type ", Indic); + return; + + elsif Ekind (Parent_Type) = E_Void + or else Ekind (Parent_Type) = E_Incomplete_Type + then + Error_Msg_N ("premature derivation of incomplete type", Indic); + return; + end if; + + -- Perhaps the parent type should be changed to the class-wide type's + -- specific type in this case to prevent cascading errors ??? + + if Is_Class_Wide_Type (Parent_Type) then + Error_Msg_N + ("parent of type extension must not be a class-wide type", Indic); + return; + end if; + + if (not Is_Package_Or_Generic_Package (Current_Scope) + and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration) + or else In_Private_Part (Current_Scope) + + then + Error_Msg_N ("invalid context for private extension", N); + end if; + + -- Set common attributes + + Set_Is_Pure (T, Is_Pure (Current_Scope)); + Set_Scope (T, Current_Scope); + Set_Ekind (T, E_Record_Type_With_Private); + Init_Size_Align (T); + + Set_Etype (T, Parent_Base); + Set_Has_Task (T, Has_Task (Parent_Base)); + + Set_Convention (T, Convention (Parent_Type)); + Set_First_Rep_Item (T, First_Rep_Item (Parent_Type)); + Set_Is_First_Subtype (T); + Make_Class_Wide_Type (T); + + if Unknown_Discriminants_Present (N) then + Set_Discriminant_Constraint (T, No_Elist); + end if; + + Build_Derived_Record_Type (N, Parent_Type, T); + + if Limited_Present (N) then + Set_Is_Limited_Record (T); + + if not Is_Limited_Type (Parent_Type) + and then + (not Is_Interface (Parent_Type) + or else not Is_Limited_Interface (Parent_Type)) + then + Error_Msg_NE ("parent type& of limited extension must be limited", + N, Parent_Type); + end if; + end if; + end Analyze_Private_Extension_Declaration; + + --------------------------------- + -- Analyze_Subtype_Declaration -- + --------------------------------- + + procedure Analyze_Subtype_Declaration (N : Node_Id) is + Id : constant Entity_Id := Defining_Identifier (N); + T : Entity_Id; + R_Checks : Check_Result; + + begin + Generate_Definition (Id); + Set_Is_Pure (Id, Is_Pure (Current_Scope)); + Init_Size_Align (Id); + + -- The following guard condition on Enter_Name is to handle cases where + -- the defining identifier has already been entered into the scope but + -- the declaration as a whole needs to be analyzed. + + -- This case in particular happens for derived enumeration types. The + -- derived enumeration type is processed as an inserted enumeration type + -- declaration followed by a rewritten subtype declaration. The defining + -- identifier, however, is entered into the name scope very early in the + -- processing of the original type declaration and therefore needs to be + -- avoided here, when the created subtype declaration is analyzed. (See + -- Build_Derived_Types) + + -- This also happens when the full view of a private type is derived + -- type with constraints. In this case the entity has been introduced + -- in the private declaration. + + if Present (Etype (Id)) + and then (Is_Private_Type (Etype (Id)) + or else Is_Task_Type (Etype (Id)) + or else Is_Rewrite_Substitution (N)) + then + null; + + else + Enter_Name (Id); + end if; + + T := Process_Subtype (Subtype_Indication (N), N, Id, 'P'); + + -- Inherit common attributes + + Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T))); + Set_Is_Volatile (Id, Is_Volatile (T)); + Set_Treat_As_Volatile (Id, Treat_As_Volatile (T)); + Set_Is_Atomic (Id, Is_Atomic (T)); + Set_Is_Ada_2005 (Id, Is_Ada_2005 (T)); + + -- In the case where there is no constraint given in the subtype + -- indication, Process_Subtype just returns the Subtype_Mark, so its + -- semantic attributes must be established here. + + if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then + Set_Etype (Id, Base_Type (T)); + + case Ekind (T) is + when Array_Kind => + Set_Ekind (Id, E_Array_Subtype); + Copy_Array_Subtype_Attributes (Id, T); + + when Decimal_Fixed_Point_Kind => + Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype); + Set_Digits_Value (Id, Digits_Value (T)); + Set_Delta_Value (Id, Delta_Value (T)); + Set_Scale_Value (Id, Scale_Value (T)); + Set_Small_Value (Id, Small_Value (T)); + Set_Scalar_Range (Id, Scalar_Range (T)); + Set_Machine_Radix_10 (Id, Machine_Radix_10 (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_RM_Size (Id, RM_Size (T)); + + when Enumeration_Kind => + Set_Ekind (Id, E_Enumeration_Subtype); + Set_First_Literal (Id, First_Literal (Base_Type (T))); + Set_Scalar_Range (Id, Scalar_Range (T)); + Set_Is_Character_Type (Id, Is_Character_Type (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_RM_Size (Id, RM_Size (T)); + + when Ordinary_Fixed_Point_Kind => + Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype); + Set_Scalar_Range (Id, Scalar_Range (T)); + Set_Small_Value (Id, Small_Value (T)); + Set_Delta_Value (Id, Delta_Value (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_RM_Size (Id, RM_Size (T)); + + when Float_Kind => + Set_Ekind (Id, E_Floating_Point_Subtype); + Set_Scalar_Range (Id, Scalar_Range (T)); + Set_Digits_Value (Id, Digits_Value (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + + when Signed_Integer_Kind => + Set_Ekind (Id, E_Signed_Integer_Subtype); + Set_Scalar_Range (Id, Scalar_Range (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_RM_Size (Id, RM_Size (T)); + + when Modular_Integer_Kind => + Set_Ekind (Id, E_Modular_Integer_Subtype); + Set_Scalar_Range (Id, Scalar_Range (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_RM_Size (Id, RM_Size (T)); + + when Class_Wide_Kind => + Set_Ekind (Id, E_Class_Wide_Subtype); + Set_First_Entity (Id, First_Entity (T)); + Set_Last_Entity (Id, Last_Entity (T)); + Set_Class_Wide_Type (Id, Class_Wide_Type (T)); + Set_Cloned_Subtype (Id, T); + Set_Is_Tagged_Type (Id, True); + Set_Has_Unknown_Discriminants + (Id, True); + + if Ekind (T) = E_Class_Wide_Subtype then + Set_Equivalent_Type (Id, Equivalent_Type (T)); + end if; + + when E_Record_Type | E_Record_Subtype => + Set_Ekind (Id, E_Record_Subtype); + + if Ekind (T) = E_Record_Subtype + and then Present (Cloned_Subtype (T)) + then + Set_Cloned_Subtype (Id, Cloned_Subtype (T)); + else + Set_Cloned_Subtype (Id, T); + end if; + + Set_First_Entity (Id, First_Entity (T)); + Set_Last_Entity (Id, Last_Entity (T)); + Set_Has_Discriminants (Id, Has_Discriminants (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_Is_Limited_Record (Id, Is_Limited_Record (T)); + Set_Has_Unknown_Discriminants + (Id, Has_Unknown_Discriminants (T)); + + if Has_Discriminants (T) then + Set_Discriminant_Constraint + (Id, Discriminant_Constraint (T)); + Set_Stored_Constraint_From_Discriminant_Constraint (Id); + + elsif Has_Unknown_Discriminants (Id) then + Set_Discriminant_Constraint (Id, No_Elist); + end if; + + if Is_Tagged_Type (T) then + Set_Is_Tagged_Type (Id); + Set_Is_Abstract (Id, Is_Abstract (T)); + Set_Primitive_Operations + (Id, Primitive_Operations (T)); + Set_Class_Wide_Type (Id, Class_Wide_Type (T)); + end if; + + when Private_Kind => + Set_Ekind (Id, Subtype_Kind (Ekind (T))); + Set_Has_Discriminants (Id, Has_Discriminants (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_First_Entity (Id, First_Entity (T)); + Set_Last_Entity (Id, Last_Entity (T)); + Set_Private_Dependents (Id, New_Elmt_List); + Set_Is_Limited_Record (Id, Is_Limited_Record (T)); + Set_Has_Unknown_Discriminants + (Id, Has_Unknown_Discriminants (T)); + + if Is_Tagged_Type (T) then + Set_Is_Tagged_Type (Id); + Set_Is_Abstract (Id, Is_Abstract (T)); + Set_Primitive_Operations + (Id, Primitive_Operations (T)); + Set_Class_Wide_Type (Id, Class_Wide_Type (T)); + end if; + + -- In general the attributes of the subtype of a private type + -- are the attributes of the partial view of parent. However, + -- the full view may be a discriminated type, and the subtype + -- must share the discriminant constraint to generate correct + -- calls to initialization procedures. + + if Has_Discriminants (T) then + Set_Discriminant_Constraint + (Id, Discriminant_Constraint (T)); + Set_Stored_Constraint_From_Discriminant_Constraint (Id); + + elsif Present (Full_View (T)) + and then Has_Discriminants (Full_View (T)) + then + Set_Discriminant_Constraint + (Id, Discriminant_Constraint (Full_View (T))); + Set_Stored_Constraint_From_Discriminant_Constraint (Id); + + -- This would seem semantically correct, but apparently + -- confuses the back-end (4412-009). To be explained ??? + + -- Set_Has_Discriminants (Id); + end if; + + Prepare_Private_Subtype_Completion (Id, N); + + when Access_Kind => + Set_Ekind (Id, E_Access_Subtype); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_Is_Access_Constant + (Id, Is_Access_Constant (T)); + Set_Directly_Designated_Type + (Id, Designated_Type (T)); + Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T)); + + -- A Pure library_item must not contain the declaration of a + -- named access type, except within a subprogram, generic + -- subprogram, task unit, or protected unit (RM 10.2.1(16)). + + if Comes_From_Source (Id) + and then In_Pure_Unit + and then not In_Subprogram_Task_Protected_Unit + then + Error_Msg_N + ("named access types not allowed in pure unit", N); + end if; + + when Concurrent_Kind => + Set_Ekind (Id, Subtype_Kind (Ekind (T))); + Set_Corresponding_Record_Type (Id, + Corresponding_Record_Type (T)); + Set_First_Entity (Id, First_Entity (T)); + Set_First_Private_Entity (Id, First_Private_Entity (T)); + Set_Has_Discriminants (Id, Has_Discriminants (T)); + Set_Is_Constrained (Id, Is_Constrained (T)); + Set_Last_Entity (Id, Last_Entity (T)); + + if Has_Discriminants (T) then + Set_Discriminant_Constraint (Id, + Discriminant_Constraint (T)); + Set_Stored_Constraint_From_Discriminant_Constraint (Id); + end if; + + -- If the subtype name denotes an incomplete type an error was + -- already reported by Process_Subtype. + + when E_Incomplete_Type => + Set_Etype (Id, Any_Type); + + when others => + raise Program_Error; + end case; + end if; + + if Etype (Id) = Any_Type then + return; + end if; + + -- Some common processing on all types + + Set_Size_Info (Id, T); + Set_First_Rep_Item (Id, First_Rep_Item (T)); + + T := Etype (Id); + + Set_Is_Immediately_Visible (Id, True); + Set_Depends_On_Private (Id, Has_Private_Component (T)); + + if Present (Generic_Parent_Type (N)) + and then + (Nkind + (Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration + or else Nkind + (Formal_Type_Definition (Parent (Generic_Parent_Type (N)))) + /= N_Formal_Private_Type_Definition) + then + if Is_Tagged_Type (Id) then + if Is_Class_Wide_Type (Id) then + Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T)); + else + Derive_Subprograms (Generic_Parent_Type (N), Id, T); + end if; + + elsif Scope (Etype (Id)) /= Standard_Standard then + Derive_Subprograms (Generic_Parent_Type (N), Id); + end if; + end if; + + if Is_Private_Type (T) + and then Present (Full_View (T)) + then + Conditional_Delay (Id, Full_View (T)); + + -- The subtypes of components or subcomponents of protected types + -- do not need freeze nodes, which would otherwise appear in the + -- wrong scope (before the freeze node for the protected type). The + -- proper subtypes are those of the subcomponents of the corresponding + -- record. + + elsif Ekind (Scope (Id)) /= E_Protected_Type + and then Present (Scope (Scope (Id))) -- error defense! + and then Ekind (Scope (Scope (Id))) /= E_Protected_Type + then + Conditional_Delay (Id, T); + end if; + + -- Check that constraint_error is raised for a scalar subtype + -- indication when the lower or upper bound of a non-null range + -- lies outside the range of the type mark. + + if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then + if Is_Scalar_Type (Etype (Id)) + and then Scalar_Range (Id) /= + Scalar_Range (Etype (Subtype_Mark + (Subtype_Indication (N)))) + then + Apply_Range_Check + (Scalar_Range (Id), + Etype (Subtype_Mark (Subtype_Indication (N)))); + + elsif Is_Array_Type (Etype (Id)) + and then Present (First_Index (Id)) + then + -- This really should be a subprogram that finds the indications + -- to check??? + + if ((Nkind (First_Index (Id)) = N_Identifier + and then Ekind (Entity (First_Index (Id))) in Scalar_Kind) + or else Nkind (First_Index (Id)) = N_Subtype_Indication) + and then + Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range + then + declare + Target_Typ : constant Entity_Id := + Etype + (First_Index (Etype + (Subtype_Mark (Subtype_Indication (N))))); + begin + R_Checks := + Range_Check + (Scalar_Range (Etype (First_Index (Id))), + Target_Typ, + Etype (First_Index (Id)), + Defining_Identifier (N)); + + Insert_Range_Checks + (R_Checks, + N, + Target_Typ, + Sloc (Defining_Identifier (N))); + end; + end if; + end if; + end if; + + Check_Eliminated (Id); + end Analyze_Subtype_Declaration; + + -------------------------------- + -- Analyze_Subtype_Indication -- + -------------------------------- + + procedure Analyze_Subtype_Indication (N : Node_Id) is + T : constant Entity_Id := Subtype_Mark (N); + R : constant Node_Id := Range_Expression (Constraint (N)); + + begin + Analyze (T); + + if R /= Error then + Analyze (R); + Set_Etype (N, Etype (R)); + else + Set_Error_Posted (R); + Set_Error_Posted (T); + end if; + end Analyze_Subtype_Indication; + + ------------------------------ + -- Analyze_Type_Declaration -- + ------------------------------ + + procedure Analyze_Type_Declaration (N : Node_Id) is + Def : constant Node_Id := Type_Definition (N); + Def_Id : constant Entity_Id := Defining_Identifier (N); + T : Entity_Id; + Prev : Entity_Id; + + Is_Remote : constant Boolean := + (Is_Remote_Types (Current_Scope) + or else Is_Remote_Call_Interface (Current_Scope)) + and then not (In_Private_Part (Current_Scope) + or else + In_Package_Body (Current_Scope)); + + procedure Check_Ops_From_Incomplete_Type; + -- If there is a tagged incomplete partial view of the type, transfer + -- its operations to the full view, and indicate that the type of the + -- controlling parameter (s) is this full view. + + ------------------------------------ + -- Check_Ops_From_Incomplete_Type -- + ------------------------------------ + + procedure Check_Ops_From_Incomplete_Type is + Elmt : Elmt_Id; + Formal : Entity_Id; + Op : Entity_Id; + + begin + if Prev /= T + and then Ekind (Prev) = E_Incomplete_Type + and then Is_Tagged_Type (Prev) + and then Is_Tagged_Type (T) + then + Elmt := First_Elmt (Primitive_Operations (Prev)); + while Present (Elmt) loop + Op := Node (Elmt); + Prepend_Elmt (Op, Primitive_Operations (T)); + + Formal := First_Formal (Op); + while Present (Formal) loop + if Etype (Formal) = Prev then + Set_Etype (Formal, T); + end if; + + Next_Formal (Formal); + end loop; + + if Etype (Op) = Prev then + Set_Etype (Op, T); + end if; + + Next_Elmt (Elmt); + end loop; + end if; + end Check_Ops_From_Incomplete_Type; + + -- Start of processing for Analyze_Type_Declaration + + begin + Prev := Find_Type_Name (N); + + -- The full view, if present, now points to the current type + + -- Ada 2005 (AI-50217): If the type was previously decorated when + -- imported through a LIMITED WITH clause, it appears as incomplete + -- but has no full view. + + if Ekind (Prev) = E_Incomplete_Type + and then Present (Full_View (Prev)) + then + T := Full_View (Prev); + else + T := Prev; + end if; + + Set_Is_Pure (T, Is_Pure (Current_Scope)); + + -- We set the flag Is_First_Subtype here. It is needed to set the + -- corresponding flag for the Implicit class-wide-type created + -- during tagged types processing. + + Set_Is_First_Subtype (T, True); + + -- Only composite types other than array types are allowed to have + -- discriminants. + + case Nkind (Def) is + + -- For derived types, the rule will be checked once we've figured + -- out the parent type. + + when N_Derived_Type_Definition => + null; + + -- For record types, discriminants are allowed + + when N_Record_Definition => + null; + + when others => + if Present (Discriminant_Specifications (N)) then + Error_Msg_N + ("elementary or array type cannot have discriminants", + Defining_Identifier + (First (Discriminant_Specifications (N)))); + end if; + end case; + + -- Elaborate the type definition according to kind, and generate + -- subsidiary (implicit) subtypes where needed. We skip this if + -- it was already done (this happens during the reanalysis that + -- follows a call to the high level optimizer). + + if not Analyzed (T) then + Set_Analyzed (T); + + case Nkind (Def) is + + when N_Access_To_Subprogram_Definition => + Access_Subprogram_Declaration (T, Def); + + -- If this is a remote access to subprogram, we must create + -- the equivalent fat pointer type, and related subprograms. + + if Is_Remote then + Process_Remote_AST_Declaration (N); + end if; + + -- Validate categorization rule against access type declaration + -- usually a violation in Pure unit, Shared_Passive unit. + + Validate_Access_Type_Declaration (T, N); + + when N_Access_To_Object_Definition => + Access_Type_Declaration (T, Def); + + -- Validate categorization rule against access type declaration + -- usually a violation in Pure unit, Shared_Passive unit. + + Validate_Access_Type_Declaration (T, N); + + -- If we are in a Remote_Call_Interface package and define + -- a RACW, Read and Write attribute must be added. + + if Is_Remote + and then Is_Remote_Access_To_Class_Wide_Type (Def_Id) + then + Add_RACW_Features (Def_Id); + end if; + + -- Set no strict aliasing flag if config pragma seen + + if Opt.No_Strict_Aliasing then + Set_No_Strict_Aliasing (Base_Type (Def_Id)); + end if; + + when N_Array_Type_Definition => + Array_Type_Declaration (T, Def); + + when N_Derived_Type_Definition => + Derived_Type_Declaration (T, N, T /= Def_Id); + + when N_Enumeration_Type_Definition => + Enumeration_Type_Declaration (T, Def); + + when N_Floating_Point_Definition => + Floating_Point_Type_Declaration (T, Def); + + when N_Decimal_Fixed_Point_Definition => + Decimal_Fixed_Point_Type_Declaration (T, Def); + + when N_Ordinary_Fixed_Point_Definition => + Ordinary_Fixed_Point_Type_Declaration (T, Def); + + when N_Signed_Integer_Type_Definition => + Signed_Integer_Type_Declaration (T, Def); + + when N_Modular_Type_Definition => + Modular_Type_Declaration (T, Def); + + when N_Record_Definition => + Record_Type_Declaration (T, N, Prev); + + when others => + raise Program_Error; + + end case; + end if; + + if Etype (T) = Any_Type then + return; + end if; + + -- Some common processing for all types + + Set_Depends_On_Private (T, Has_Private_Component (T)); + Check_Ops_From_Incomplete_Type; + + -- Both the declared entity, and its anonymous base type if one + -- was created, need freeze nodes allocated. + + declare + B : constant Entity_Id := Base_Type (T); + + begin + -- In the case where the base type is different from the first + -- subtype, we pre-allocate a freeze node, and set the proper link + -- to the first subtype. Freeze_Entity will use this preallocated + -- freeze node when it freezes the entity. + + if B /= T then + Ensure_Freeze_Node (B); + Set_First_Subtype_Link (Freeze_Node (B), T); + end if; + + if not From_With_Type (T) then + Set_Has_Delayed_Freeze (T); + end if; + end; + + -- Case of T is the full declaration of some private type which has + -- been swapped in Defining_Identifier (N). + + if T /= Def_Id and then Is_Private_Type (Def_Id) then + Process_Full_View (N, T, Def_Id); + + -- Record the reference. The form of this is a little strange, + -- since the full declaration has been swapped in. So the first + -- parameter here represents the entity to which a reference is + -- made which is the "real" entity, i.e. the one swapped in, + -- and the second parameter provides the reference location. + + Generate_Reference (T, T, 'c'); + Set_Completion_Referenced (Def_Id); + + -- For completion of incomplete type, process incomplete dependents + -- and always mark the full type as referenced (it is the incomplete + -- type that we get for any real reference). + + elsif Ekind (Prev) = E_Incomplete_Type then + Process_Incomplete_Dependents (N, T, Prev); + Generate_Reference (Prev, Def_Id, 'c'); + Set_Completion_Referenced (Def_Id); + + -- If not private type or incomplete type completion, this is a real + -- definition of a new entity, so record it. + + else + Generate_Definition (Def_Id); + end if; + + Check_Eliminated (Def_Id); + end Analyze_Type_Declaration; + + -------------------------- + -- Analyze_Variant_Part -- + -------------------------- + + procedure Analyze_Variant_Part (N : Node_Id) is + + procedure Non_Static_Choice_Error (Choice : Node_Id); + -- Error routine invoked by the generic instantiation below when + -- the variant part has a non static choice. + + procedure Process_Declarations (Variant : Node_Id); + -- Analyzes all the declarations associated with a Variant. + -- Needed by the generic instantiation below. + + package Variant_Choices_Processing is new + Generic_Choices_Processing + (Get_Alternatives => Variants, + Get_Choices => Discrete_Choices, + Process_Empty_Choice => No_OP, + Process_Non_Static_Choice => Non_Static_Choice_Error, + Process_Associated_Node => Process_Declarations); + use Variant_Choices_Processing; + -- Instantiation of the generic choice processing package + + ----------------------------- + -- Non_Static_Choice_Error -- + ----------------------------- + + procedure Non_Static_Choice_Error (Choice : Node_Id) is + begin + Flag_Non_Static_Expr + ("choice given in variant part is not static!", Choice); + end Non_Static_Choice_Error; + + -------------------------- + -- Process_Declarations -- + -------------------------- + + procedure Process_Declarations (Variant : Node_Id) is + begin + if not Null_Present (Component_List (Variant)) then + Analyze_Declarations (Component_Items (Component_List (Variant))); + + if Present (Variant_Part (Component_List (Variant))) then + Analyze (Variant_Part (Component_List (Variant))); + end if; + end if; + end Process_Declarations; + + -- Variables local to Analyze_Case_Statement + + Discr_Name : Node_Id; + Discr_Type : Entity_Id; + + Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N)); + Last_Choice : Nat; + Dont_Care : Boolean; + Others_Present : Boolean := False; + + -- Start of processing for Analyze_Variant_Part + + begin + Discr_Name := Name (N); + Analyze (Discr_Name); + + if Ekind (Entity (Discr_Name)) /= E_Discriminant then + Error_Msg_N ("invalid discriminant name in variant part", Discr_Name); + end if; + + Discr_Type := Etype (Entity (Discr_Name)); + + if not Is_Discrete_Type (Discr_Type) then + Error_Msg_N + ("discriminant in a variant part must be of a discrete type", + Name (N)); + return; + end if; + + -- Call the instantiated Analyze_Choices which does the rest of the work + + Analyze_Choices + (N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present); + end Analyze_Variant_Part; + + ---------------------------- + -- Array_Type_Declaration -- + ---------------------------- + + procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is + Component_Def : constant Node_Id := Component_Definition (Def); + Element_Type : Entity_Id; + Implicit_Base : Entity_Id; + Index : Node_Id; + Related_Id : Entity_Id := Empty; + Nb_Index : Nat; + P : constant Node_Id := Parent (Def); + Priv : Entity_Id; + + begin + if Nkind (Def) = N_Constrained_Array_Definition then + Index := First (Discrete_Subtype_Definitions (Def)); + else + Index := First (Subtype_Marks (Def)); + end if; + + -- Find proper names for the implicit types which may be public. + -- in case of anonymous arrays we use the name of the first object + -- of that type as prefix. + + if No (T) then + Related_Id := Defining_Identifier (P); + else + Related_Id := T; + end if; + + Nb_Index := 1; + while Present (Index) loop + Analyze (Index); + Make_Index (Index, P, Related_Id, Nb_Index); + Next_Index (Index); + Nb_Index := Nb_Index + 1; + end loop; + + if Present (Subtype_Indication (Component_Def)) then + Element_Type := Process_Subtype (Subtype_Indication (Component_Def), + P, Related_Id, 'C'); + + -- Ada 2005 (AI-230): Access Definition case + + else pragma Assert (Present (Access_Definition (Component_Def))); + Element_Type := Access_Definition + (Related_Nod => Related_Id, + N => Access_Definition (Component_Def)); + Set_Is_Local_Anonymous_Access (Element_Type); + + -- Ada 2005 (AI-230): In case of components that are anonymous + -- access types the level of accessibility depends on the enclosing + -- type declaration + + Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230) + + -- Ada 2005 (AI-254) + + declare + CD : constant Node_Id := + Access_To_Subprogram_Definition + (Access_Definition (Component_Def)); + begin + if Present (CD) and then Protected_Present (CD) then + Element_Type := + Replace_Anonymous_Access_To_Protected_Subprogram + (Def, Element_Type); + end if; + end; + end if; + + -- Constrained array case + + if No (T) then + T := Create_Itype (E_Void, P, Related_Id, 'T'); + end if; + + if Nkind (Def) = N_Constrained_Array_Definition then + + -- Establish Implicit_Base as unconstrained base type + + Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B'); + + Init_Size_Align (Implicit_Base); + Set_Etype (Implicit_Base, Implicit_Base); + Set_Scope (Implicit_Base, Current_Scope); + Set_Has_Delayed_Freeze (Implicit_Base); + + -- The constrained array type is a subtype of the unconstrained one + + Set_Ekind (T, E_Array_Subtype); + Init_Size_Align (T); + Set_Etype (T, Implicit_Base); + Set_Scope (T, Current_Scope); + Set_Is_Constrained (T, True); + Set_First_Index (T, First (Discrete_Subtype_Definitions (Def))); + Set_Has_Delayed_Freeze (T); + + -- Complete setup of implicit base type + + Set_First_Index (Implicit_Base, First_Index (T)); + Set_Component_Type (Implicit_Base, Element_Type); + Set_Has_Task (Implicit_Base, Has_Task (Element_Type)); + Set_Component_Size (Implicit_Base, Uint_0); + Set_Has_Controlled_Component + (Implicit_Base, Has_Controlled_Component + (Element_Type) + or else + Is_Controlled (Element_Type)); + Set_Finalize_Storage_Only + (Implicit_Base, Finalize_Storage_Only + (Element_Type)); + + -- Unconstrained array case + + else + Set_Ekind (T, E_Array_Type); + Init_Size_Align (T); + Set_Etype (T, T); + Set_Scope (T, Current_Scope); + Set_Component_Size (T, Uint_0); + Set_Is_Constrained (T, False); + Set_First_Index (T, First (Subtype_Marks (Def))); + Set_Has_Delayed_Freeze (T, True); + Set_Has_Task (T, Has_Task (Element_Type)); + Set_Has_Controlled_Component (T, Has_Controlled_Component + (Element_Type) + or else + Is_Controlled (Element_Type)); + Set_Finalize_Storage_Only (T, Finalize_Storage_Only + (Element_Type)); + end if; + + Set_Component_Type (Base_Type (T), Element_Type); + + if Aliased_Present (Component_Definition (Def)) then + Set_Has_Aliased_Components (Etype (T)); + end if; + + -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the + -- array type to ensure that objects of this type are initialized. + + if Ada_Version >= Ada_05 + and then Can_Never_Be_Null (Element_Type) + then + Set_Can_Never_Be_Null (T); + + if Null_Exclusion_Present (Component_Definition (Def)) + and then Can_Never_Be_Null (Element_Type) + + -- No need to check itypes because in their case this check + -- was done at their point of creation + + and then not Is_Itype (Element_Type) + then + Error_Msg_N + ("(Ada 2005) already a null-excluding type", + Subtype_Indication (Component_Definition (Def))); + end if; + end if; + + Priv := Private_Component (Element_Type); + + if Present (Priv) then + + -- Check for circular definitions + + if Priv = Any_Type then + Set_Component_Type (Etype (T), Any_Type); + + -- There is a gap in the visibility of operations on the composite + -- type only if the component type is defined in a different scope. + + elsif Scope (Priv) = Current_Scope then + null; + + elsif Is_Limited_Type (Priv) then + Set_Is_Limited_Composite (Etype (T)); + Set_Is_Limited_Composite (T); + else + Set_Is_Private_Composite (Etype (T)); + Set_Is_Private_Composite (T); + end if; + end if; + + -- Create a concatenation operator for the new type. Internal + -- array types created for packed entities do not need such, they + -- are compatible with the user-defined type. + + if Number_Dimensions (T) = 1 + and then not Is_Packed_Array_Type (T) + then + New_Concatenation_Op (T); + end if; + + -- In the case of an unconstrained array the parser has already + -- verified that all the indices are unconstrained but we still + -- need to make sure that the element type is constrained. + + if Is_Indefinite_Subtype (Element_Type) then + Error_Msg_N + ("unconstrained element type in array declaration", + Subtype_Indication (Component_Def)); + + elsif Is_Abstract (Element_Type) then + Error_Msg_N + ("the type of a component cannot be abstract", + Subtype_Indication (Component_Def)); + end if; + + end Array_Type_Declaration; + + ------------------------------------------------------ + -- Replace_Anonymous_Access_To_Protected_Subprogram -- + ------------------------------------------------------ + + function Replace_Anonymous_Access_To_Protected_Subprogram + (N : Node_Id; + Prev_E : Entity_Id) return Entity_Id + is + Loc : constant Source_Ptr := Sloc (N); + + Curr_Scope : constant Scope_Stack_Entry := + Scope_Stack.Table (Scope_Stack.Last); + + Anon : constant Entity_Id := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('S')); + + Acc : Node_Id; + Comp : Node_Id; + Decl : Node_Id; + P : Node_Id; + + begin + Set_Is_Internal (Anon); + + case Nkind (N) is + when N_Component_Declaration | + N_Unconstrained_Array_Definition | + N_Constrained_Array_Definition => + Comp := Component_Definition (N); + Acc := Access_Definition (Component_Definition (N)); + + when N_Discriminant_Specification => + Comp := Discriminant_Type (N); + Acc := Discriminant_Type (N); + + when N_Parameter_Specification => + Comp := Parameter_Type (N); + Acc := Parameter_Type (N); + + when others => + raise Program_Error; + end case; + + Decl := Make_Full_Type_Declaration (Loc, + Defining_Identifier => Anon, + Type_Definition => + Copy_Separate_Tree (Access_To_Subprogram_Definition (Acc))); + + Mark_Rewrite_Insertion (Decl); + + -- Insert the new declaration in the nearest enclosing scope + + P := Parent (N); + while Present (P) and then not Has_Declarations (P) loop + P := Parent (P); + end loop; + + pragma Assert (Present (P)); + + if Nkind (P) = N_Package_Specification then + Prepend (Decl, Visible_Declarations (P)); + else + Prepend (Decl, Declarations (P)); + end if; + + -- Replace the anonymous type with an occurrence of the new declaration. + -- In all cases the rewritten node does not have the null-exclusion + -- attribute because (if present) it was already inherited by the + -- anonymous entity (Anon). Thus, in case of components we do not + -- inherit this attribute. + + if Nkind (N) = N_Parameter_Specification then + Rewrite (Comp, New_Occurrence_Of (Anon, Loc)); + Set_Etype (Defining_Identifier (N), Anon); + Set_Null_Exclusion_Present (N, False); + else + Rewrite (Comp, + Make_Component_Definition (Loc, + Subtype_Indication => New_Occurrence_Of (Anon, Loc))); + end if; + + Mark_Rewrite_Insertion (Comp); + + -- Temporarily remove the current scope from the stack to add the new + -- declarations to the enclosing scope + + Scope_Stack.Decrement_Last; + Analyze (Decl); + Scope_Stack.Append (Curr_Scope); + + Set_Original_Access_Type (Anon, Prev_E); + return Anon; + end Replace_Anonymous_Access_To_Protected_Subprogram; + + ------------------------------- + -- Build_Derived_Access_Type -- + ------------------------------- + + procedure Build_Derived_Access_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id) + is + S : constant Node_Id := Subtype_Indication (Type_Definition (N)); + + Desig_Type : Entity_Id; + Discr : Entity_Id; + Discr_Con_Elist : Elist_Id; + Discr_Con_El : Elmt_Id; + Subt : Entity_Id; + + begin + -- Set the designated type so it is available in case this is + -- an access to a self-referential type, e.g. a standard list + -- type with a next pointer. Will be reset after subtype is built. + + Set_Directly_Designated_Type + (Derived_Type, Designated_Type (Parent_Type)); + + Subt := Process_Subtype (S, N); + + if Nkind (S) /= N_Subtype_Indication + and then Subt /= Base_Type (Subt) + then + Set_Ekind (Derived_Type, E_Access_Subtype); + end if; + + if Ekind (Derived_Type) = E_Access_Subtype then + declare + Pbase : constant Entity_Id := Base_Type (Parent_Type); + Ibase : constant Entity_Id := + Create_Itype (Ekind (Pbase), N, Derived_Type, 'B'); + Svg_Chars : constant Name_Id := Chars (Ibase); + Svg_Next_E : constant Entity_Id := Next_Entity (Ibase); + + begin + Copy_Node (Pbase, Ibase); + + Set_Chars (Ibase, Svg_Chars); + Set_Next_Entity (Ibase, Svg_Next_E); + Set_Sloc (Ibase, Sloc (Derived_Type)); + Set_Scope (Ibase, Scope (Derived_Type)); + Set_Freeze_Node (Ibase, Empty); + Set_Is_Frozen (Ibase, False); + Set_Comes_From_Source (Ibase, False); + Set_Is_First_Subtype (Ibase, False); + + Set_Etype (Ibase, Pbase); + Set_Etype (Derived_Type, Ibase); + end; + end if; + + Set_Directly_Designated_Type + (Derived_Type, Designated_Type (Subt)); + + Set_Is_Constrained (Derived_Type, Is_Constrained (Subt)); + Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type)); + Set_Size_Info (Derived_Type, Parent_Type); + Set_RM_Size (Derived_Type, RM_Size (Parent_Type)); + Set_Depends_On_Private (Derived_Type, + Has_Private_Component (Derived_Type)); + Conditional_Delay (Derived_Type, Subt); + + -- Ada 2005 (AI-231). Set the null-exclusion attribute + + if Null_Exclusion_Present (Type_Definition (N)) + or else Can_Never_Be_Null (Parent_Type) + then + Set_Can_Never_Be_Null (Derived_Type); + end if; + + -- Note: we do not copy the Storage_Size_Variable, since + -- we always go to the root type for this information. + + -- Apply range checks to discriminants for derived record case + -- ??? THIS CODE SHOULD NOT BE HERE REALLY. + + Desig_Type := Designated_Type (Derived_Type); + if Is_Composite_Type (Desig_Type) + and then (not Is_Array_Type (Desig_Type)) + and then Has_Discriminants (Desig_Type) + and then Base_Type (Desig_Type) /= Desig_Type + then + Discr_Con_Elist := Discriminant_Constraint (Desig_Type); + Discr_Con_El := First_Elmt (Discr_Con_Elist); + + Discr := First_Discriminant (Base_Type (Desig_Type)); + while Present (Discr_Con_El) loop + Apply_Range_Check (Node (Discr_Con_El), Etype (Discr)); + Next_Elmt (Discr_Con_El); + Next_Discriminant (Discr); + end loop; + end if; + end Build_Derived_Access_Type; + + ------------------------------ + -- Build_Derived_Array_Type -- + ------------------------------ + + procedure Build_Derived_Array_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Tdef : constant Node_Id := Type_Definition (N); + Indic : constant Node_Id := Subtype_Indication (Tdef); + Parent_Base : constant Entity_Id := Base_Type (Parent_Type); + Implicit_Base : Entity_Id; + New_Indic : Node_Id; + + procedure Make_Implicit_Base; + -- If the parent subtype is constrained, the derived type is a + -- subtype of an implicit base type derived from the parent base. + + ------------------------ + -- Make_Implicit_Base -- + ------------------------ + + procedure Make_Implicit_Base is + begin + Implicit_Base := + Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B'); + + Set_Ekind (Implicit_Base, Ekind (Parent_Base)); + Set_Etype (Implicit_Base, Parent_Base); + + Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base); + Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base); + + Set_Has_Delayed_Freeze (Implicit_Base, True); + end Make_Implicit_Base; + + -- Start of processing for Build_Derived_Array_Type + + begin + if not Is_Constrained (Parent_Type) then + if Nkind (Indic) /= N_Subtype_Indication then + Set_Ekind (Derived_Type, E_Array_Type); + + Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type); + Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type); + + Set_Has_Delayed_Freeze (Derived_Type, True); + + else + Make_Implicit_Base; + Set_Etype (Derived_Type, Implicit_Base); + + New_Indic := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Derived_Type, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Reference_To (Implicit_Base, Loc), + Constraint => Constraint (Indic))); + + Rewrite (N, New_Indic); + Analyze (N); + end if; + + else + if Nkind (Indic) /= N_Subtype_Indication then + Make_Implicit_Base; + + Set_Ekind (Derived_Type, Ekind (Parent_Type)); + Set_Etype (Derived_Type, Implicit_Base); + Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type); + + else + Error_Msg_N ("illegal constraint on constrained type", Indic); + end if; + end if; + + -- If parent type is not a derived type itself, and is declared in + -- closed scope (e.g. a subprogram), then we must explicitly introduce + -- the new type's concatenation operator since Derive_Subprograms + -- will not inherit the parent's operator. If the parent type is + -- unconstrained, the operator is of the unconstrained base type. + + if Number_Dimensions (Parent_Type) = 1 + and then not Is_Limited_Type (Parent_Type) + and then not Is_Derived_Type (Parent_Type) + and then not Is_Package_Or_Generic_Package + (Scope (Base_Type (Parent_Type))) + then + if not Is_Constrained (Parent_Type) + and then Is_Constrained (Derived_Type) + then + New_Concatenation_Op (Implicit_Base); + else + New_Concatenation_Op (Derived_Type); + end if; + end if; + end Build_Derived_Array_Type; + + ----------------------------------- + -- Build_Derived_Concurrent_Type -- + ----------------------------------- + + procedure Build_Derived_Concurrent_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id) + is + D_Constraint : Node_Id; + Disc_Spec : Node_Id; + Old_Disc : Entity_Id; + New_Disc : Entity_Id; + + Constraint_Present : constant Boolean := + Nkind (Subtype_Indication (Type_Definition (N))) + = N_Subtype_Indication; + + begin + Set_Stored_Constraint (Derived_Type, No_Elist); + + if Is_Task_Type (Parent_Type) then + Set_Storage_Size_Variable (Derived_Type, + Storage_Size_Variable (Parent_Type)); + end if; + + if Present (Discriminant_Specifications (N)) then + New_Scope (Derived_Type); + Check_Or_Process_Discriminants (N, Derived_Type); + End_Scope; + + elsif Constraint_Present then + + -- Build constrained subtype and derive from it + + declare + Loc : constant Source_Ptr := Sloc (N); + Anon : constant Entity_Id := + Make_Defining_Identifier (Loc, + New_External_Name (Chars (Derived_Type), 'T')); + Decl : Node_Id; + + begin + Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Anon, + Subtype_Indication => + New_Copy_Tree (Subtype_Indication (Type_Definition (N)))); + Insert_Before (N, Decl); + Rewrite (Subtype_Indication (Type_Definition (N)), + New_Occurrence_Of (Anon, Loc)); + Analyze (Decl); + Set_Analyzed (Derived_Type, False); + Analyze (N); + return; + end; + end if; + + -- All attributes are inherited from parent. In particular, + -- entries and the corresponding record type are the same. + -- Discriminants may be renamed, and must be treated separately. + + Set_Has_Discriminants + (Derived_Type, Has_Discriminants (Parent_Type)); + Set_Corresponding_Record_Type + (Derived_Type, Corresponding_Record_Type (Parent_Type)); + + if Constraint_Present then + if not Has_Discriminants (Parent_Type) then + Error_Msg_N ("untagged parent must have discriminants", N); + + elsif Present (Discriminant_Specifications (N)) then + + -- Verify that new discriminants are used to constrain old ones + + D_Constraint := + First + (Constraints + (Constraint (Subtype_Indication (Type_Definition (N))))); + + Old_Disc := First_Discriminant (Parent_Type); + New_Disc := First_Discriminant (Derived_Type); + Disc_Spec := First (Discriminant_Specifications (N)); + while Present (Old_Disc) and then Present (Disc_Spec) loop + if Nkind (Discriminant_Type (Disc_Spec)) /= + N_Access_Definition + then + Analyze (Discriminant_Type (Disc_Spec)); + + if not Subtypes_Statically_Compatible ( + Etype (Discriminant_Type (Disc_Spec)), + Etype (Old_Disc)) + then + Error_Msg_N + ("not statically compatible with parent discriminant", + Discriminant_Type (Disc_Spec)); + end if; + end if; + + if Nkind (D_Constraint) = N_Identifier + and then Chars (D_Constraint) /= + Chars (Defining_Identifier (Disc_Spec)) + then + Error_Msg_N ("new discriminants must constrain old ones", + D_Constraint); + else + Set_Corresponding_Discriminant (New_Disc, Old_Disc); + end if; + + Next_Discriminant (Old_Disc); + Next_Discriminant (New_Disc); + Next (Disc_Spec); + end loop; + + if Present (Old_Disc) or else Present (Disc_Spec) then + Error_Msg_N ("discriminant mismatch in derivation", N); + end if; + + end if; + + elsif Present (Discriminant_Specifications (N)) then + Error_Msg_N + ("missing discriminant constraint in untagged derivation", + N); + end if; + + if Present (Discriminant_Specifications (N)) then + Old_Disc := First_Discriminant (Parent_Type); + while Present (Old_Disc) loop + + if No (Next_Entity (Old_Disc)) + or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant + then + Set_Next_Entity (Last_Entity (Derived_Type), + Next_Entity (Old_Disc)); + exit; + end if; + + Next_Discriminant (Old_Disc); + end loop; + + else + Set_First_Entity (Derived_Type, First_Entity (Parent_Type)); + if Has_Discriminants (Parent_Type) then + Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type)); + Set_Discriminant_Constraint ( + Derived_Type, Discriminant_Constraint (Parent_Type)); + end if; + end if; + + Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type)); + + Set_Has_Completion (Derived_Type); + end Build_Derived_Concurrent_Type; + + ------------------------------------ + -- Build_Derived_Enumeration_Type -- + ------------------------------------ + + procedure Build_Derived_Enumeration_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Def : constant Node_Id := Type_Definition (N); + Indic : constant Node_Id := Subtype_Indication (Def); + Implicit_Base : Entity_Id; + Literal : Entity_Id; + New_Lit : Entity_Id; + Literals_List : List_Id; + Type_Decl : Node_Id; + Hi, Lo : Node_Id; + Rang_Expr : Node_Id; + + begin + -- Since types Standard.Character and Standard.Wide_Character do + -- not have explicit literals lists we need to process types derived + -- from them specially. This is handled by Derived_Standard_Character. + -- If the parent type is a generic type, there are no literals either, + -- and we construct the same skeletal representation as for the generic + -- parent type. + + if Root_Type (Parent_Type) = Standard_Character + or else Root_Type (Parent_Type) = Standard_Wide_Character + or else Root_Type (Parent_Type) = Standard_Wide_Wide_Character + then + Derived_Standard_Character (N, Parent_Type, Derived_Type); + + elsif Is_Generic_Type (Root_Type (Parent_Type)) then + declare + Lo : Node_Id; + Hi : Node_Id; + + begin + Lo := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => New_Reference_To (Derived_Type, Loc)); + Set_Etype (Lo, Derived_Type); + + Hi := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => New_Reference_To (Derived_Type, Loc)); + Set_Etype (Hi, Derived_Type); + + Set_Scalar_Range (Derived_Type, + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi)); + end; + + else + -- If a constraint is present, analyze the bounds to catch + -- premature usage of the derived literals. + + if Nkind (Indic) = N_Subtype_Indication + and then Nkind (Range_Expression (Constraint (Indic))) = N_Range + then + Analyze (Low_Bound (Range_Expression (Constraint (Indic)))); + Analyze (High_Bound (Range_Expression (Constraint (Indic)))); + end if; + + -- Introduce an implicit base type for the derived type even + -- if there is no constraint attached to it, since this seems + -- closer to the Ada semantics. Build a full type declaration + -- tree for the derived type using the implicit base type as + -- the defining identifier. The build a subtype declaration + -- tree which applies the constraint (if any) have it replace + -- the derived type declaration. + + Literal := First_Literal (Parent_Type); + Literals_List := New_List; + while Present (Literal) + and then Ekind (Literal) = E_Enumeration_Literal + loop + -- Literals of the derived type have the same representation as + -- those of the parent type, but this representation can be + -- overridden by an explicit representation clause. Indicate + -- that there is no explicit representation given yet. These + -- derived literals are implicit operations of the new type, + -- and can be overridden by explicit ones. + + if Nkind (Literal) = N_Defining_Character_Literal then + New_Lit := + Make_Defining_Character_Literal (Loc, Chars (Literal)); + else + New_Lit := Make_Defining_Identifier (Loc, Chars (Literal)); + end if; + + Set_Ekind (New_Lit, E_Enumeration_Literal); + Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal)); + Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal)); + Set_Enumeration_Rep_Expr (New_Lit, Empty); + Set_Alias (New_Lit, Literal); + Set_Is_Known_Valid (New_Lit, True); + + Append (New_Lit, Literals_List); + Next_Literal (Literal); + end loop; + + Implicit_Base := + Make_Defining_Identifier (Sloc (Derived_Type), + New_External_Name (Chars (Derived_Type), 'B')); + + -- Indicate the proper nature of the derived type. This must + -- be done before analysis of the literals, to recognize cases + -- when a literal may be hidden by a previous explicit function + -- definition (cf. c83031a). + + Set_Ekind (Derived_Type, E_Enumeration_Subtype); + Set_Etype (Derived_Type, Implicit_Base); + + Type_Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Implicit_Base, + Discriminant_Specifications => No_List, + Type_Definition => + Make_Enumeration_Type_Definition (Loc, Literals_List)); + + Mark_Rewrite_Insertion (Type_Decl); + Insert_Before (N, Type_Decl); + Analyze (Type_Decl); + + -- After the implicit base is analyzed its Etype needs to be changed + -- to reflect the fact that it is derived from the parent type which + -- was ignored during analysis. We also set the size at this point. + + Set_Etype (Implicit_Base, Parent_Type); + + Set_Size_Info (Implicit_Base, Parent_Type); + Set_RM_Size (Implicit_Base, RM_Size (Parent_Type)); + Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type)); + + Set_Has_Non_Standard_Rep + (Implicit_Base, Has_Non_Standard_Rep + (Parent_Type)); + Set_Has_Delayed_Freeze (Implicit_Base); + + -- Process the subtype indication including a validation check + -- on the constraint, if any. If a constraint is given, its bounds + -- must be implicitly converted to the new type. + + if Nkind (Indic) = N_Subtype_Indication then + declare + R : constant Node_Id := + Range_Expression (Constraint (Indic)); + + begin + if Nkind (R) = N_Range then + Hi := Build_Scalar_Bound + (High_Bound (R), Parent_Type, Implicit_Base); + Lo := Build_Scalar_Bound + (Low_Bound (R), Parent_Type, Implicit_Base); + + else + -- Constraint is a Range attribute. Replace with the + -- explicit mention of the bounds of the prefix, which must + -- be a subtype. + + Analyze (Prefix (R)); + Hi := + Convert_To (Implicit_Base, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Last, + Prefix => + New_Occurrence_Of (Entity (Prefix (R)), Loc))); + + Lo := + Convert_To (Implicit_Base, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_First, + Prefix => + New_Occurrence_Of (Entity (Prefix (R)), Loc))); + end if; + end; + + else + Hi := + Build_Scalar_Bound + (Type_High_Bound (Parent_Type), + Parent_Type, Implicit_Base); + Lo := + Build_Scalar_Bound + (Type_Low_Bound (Parent_Type), + Parent_Type, Implicit_Base); + end if; + + Rang_Expr := + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi); + + -- If we constructed a default range for the case where no range + -- was given, then the expressions in the range must not freeze + -- since they do not correspond to expressions in the source. + + if Nkind (Indic) /= N_Subtype_Indication then + Set_Must_Not_Freeze (Lo); + Set_Must_Not_Freeze (Hi); + Set_Must_Not_Freeze (Rang_Expr); + end if; + + Rewrite (N, + Make_Subtype_Declaration (Loc, + Defining_Identifier => Derived_Type, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc), + Constraint => + Make_Range_Constraint (Loc, + Range_Expression => Rang_Expr)))); + + Analyze (N); + + -- If pragma Discard_Names applies on the first subtype of the + -- parent type, then it must be applied on this subtype as well. + + if Einfo.Discard_Names (First_Subtype (Parent_Type)) then + Set_Discard_Names (Derived_Type); + end if; + + -- Apply a range check. Since this range expression doesn't have an + -- Etype, we have to specifically pass the Source_Typ parameter. Is + -- this right??? + + if Nkind (Indic) = N_Subtype_Indication then + Apply_Range_Check (Range_Expression (Constraint (Indic)), + Parent_Type, + Source_Typ => Entity (Subtype_Mark (Indic))); + end if; + end if; + end Build_Derived_Enumeration_Type; + + -------------------------------- + -- Build_Derived_Numeric_Type -- + -------------------------------- + + procedure Build_Derived_Numeric_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Tdef : constant Node_Id := Type_Definition (N); + Indic : constant Node_Id := Subtype_Indication (Tdef); + Parent_Base : constant Entity_Id := Base_Type (Parent_Type); + No_Constraint : constant Boolean := Nkind (Indic) /= + N_Subtype_Indication; + Implicit_Base : Entity_Id; + + Lo : Node_Id; + Hi : Node_Id; + + begin + -- Process the subtype indication including a validation check on + -- the constraint if any. + + Discard_Node (Process_Subtype (Indic, N)); + + -- Introduce an implicit base type for the derived type even if there + -- is no constraint attached to it, since this seems closer to the Ada + -- semantics. + + Implicit_Base := + Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B'); + + Set_Etype (Implicit_Base, Parent_Base); + Set_Ekind (Implicit_Base, Ekind (Parent_Base)); + Set_Size_Info (Implicit_Base, Parent_Base); + Set_RM_Size (Implicit_Base, RM_Size (Parent_Base)); + Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base)); + Set_Parent (Implicit_Base, Parent (Derived_Type)); + + if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then + Set_RM_Size (Implicit_Base, RM_Size (Parent_Base)); + end if; + + Set_Has_Delayed_Freeze (Implicit_Base); + + Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base)); + Hi := New_Copy_Tree (Type_High_Bound (Parent_Base)); + + Set_Scalar_Range (Implicit_Base, + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi)); + + if Has_Infinities (Parent_Base) then + Set_Includes_Infinities (Scalar_Range (Implicit_Base)); + end if; + + -- The Derived_Type, which is the entity of the declaration, is a + -- subtype of the implicit base. Its Ekind is a subtype, even in the + -- absence of an explicit constraint. + + Set_Etype (Derived_Type, Implicit_Base); + + -- If we did not have a constraint, then the Ekind is set from the + -- parent type (otherwise Process_Subtype has set the bounds) + + if No_Constraint then + Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type))); + end if; + + -- If we did not have a range constraint, then set the range from the + -- parent type. Otherwise, the call to Process_Subtype has set the + -- bounds. + + if No_Constraint + or else not Has_Range_Constraint (Indic) + then + Set_Scalar_Range (Derived_Type, + Make_Range (Loc, + Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)), + High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type)))); + Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type)); + + if Has_Infinities (Parent_Type) then + Set_Includes_Infinities (Scalar_Range (Derived_Type)); + end if; + end if; + + -- Set remaining type-specific fields, depending on numeric type + + if Is_Modular_Integer_Type (Parent_Type) then + Set_Modulus (Implicit_Base, Modulus (Parent_Base)); + + Set_Non_Binary_Modulus + (Implicit_Base, Non_Binary_Modulus (Parent_Base)); + + elsif Is_Floating_Point_Type (Parent_Type) then + + -- Digits of base type is always copied from the digits value of + -- the parent base type, but the digits of the derived type will + -- already have been set if there was a constraint present. + + Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base)); + Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base)); + + if No_Constraint then + Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type)); + end if; + + elsif Is_Fixed_Point_Type (Parent_Type) then + + -- Small of base type and derived type are always copied from the + -- parent base type, since smalls never change. The delta of the + -- base type is also copied from the parent base type. However the + -- delta of the derived type will have been set already if a + -- constraint was present. + + Set_Small_Value (Derived_Type, Small_Value (Parent_Base)); + Set_Small_Value (Implicit_Base, Small_Value (Parent_Base)); + Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base)); + + if No_Constraint then + Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type)); + end if; + + -- The scale and machine radix in the decimal case are always + -- copied from the parent base type. + + if Is_Decimal_Fixed_Point_Type (Parent_Type) then + Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base)); + Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base)); + + Set_Machine_Radix_10 + (Derived_Type, Machine_Radix_10 (Parent_Base)); + Set_Machine_Radix_10 + (Implicit_Base, Machine_Radix_10 (Parent_Base)); + + Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base)); + + if No_Constraint then + Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base)); + + else + -- the analysis of the subtype_indication sets the + -- digits value of the derived type. + + null; + end if; + end if; + end if; + + -- The type of the bounds is that of the parent type, and they + -- must be converted to the derived type. + + Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc); + + -- The implicit_base should be frozen when the derived type is frozen, + -- but note that it is used in the conversions of the bounds. For fixed + -- types we delay the determination of the bounds until the proper + -- freezing point. For other numeric types this is rejected by GCC, for + -- reasons that are currently unclear (???), so we choose to freeze the + -- implicit base now. In the case of integers and floating point types + -- this is harmless because subsequent representation clauses cannot + -- affect anything, but it is still baffling that we cannot use the + -- same mechanism for all derived numeric types. + + if Is_Fixed_Point_Type (Parent_Type) then + Conditional_Delay (Implicit_Base, Parent_Type); + else + Freeze_Before (N, Implicit_Base); + end if; + end Build_Derived_Numeric_Type; + + -------------------------------- + -- Build_Derived_Private_Type -- + -------------------------------- + + procedure Build_Derived_Private_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Is_Completion : Boolean; + Derive_Subps : Boolean := True) + is + Der_Base : Entity_Id; + Discr : Entity_Id; + Full_Decl : Node_Id := Empty; + Full_Der : Entity_Id; + Full_P : Entity_Id; + Last_Discr : Entity_Id; + Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type)); + Swapped : Boolean := False; + + procedure Copy_And_Build; + -- Copy derived type declaration, replace parent with its full view, + -- and analyze new declaration. + + -------------------- + -- Copy_And_Build -- + -------------------- + + procedure Copy_And_Build is + Full_N : Node_Id; + + begin + if Ekind (Parent_Type) in Record_Kind + or else + (Ekind (Parent_Type) in Enumeration_Kind + and then Root_Type (Parent_Type) /= Standard_Character + and then Root_Type (Parent_Type) /= Standard_Wide_Character + and then Root_Type (Parent_Type) /= Standard_Wide_Wide_Character + and then not Is_Generic_Type (Root_Type (Parent_Type))) + then + Full_N := New_Copy_Tree (N); + Insert_After (N, Full_N); + Build_Derived_Type ( + Full_N, Parent_Type, Full_Der, True, Derive_Subps => False); + + else + Build_Derived_Type ( + N, Parent_Type, Full_Der, True, Derive_Subps => False); + end if; + end Copy_And_Build; + + -- Start of processing for Build_Derived_Private_Type + + begin + if Is_Tagged_Type (Parent_Type) then + Build_Derived_Record_Type + (N, Parent_Type, Derived_Type, Derive_Subps); + return; + + elsif Has_Discriminants (Parent_Type) then + if Present (Full_View (Parent_Type)) then + if not Is_Completion then + + -- Copy declaration for subsequent analysis, to provide a + -- completion for what is a private declaration. Indicate that + -- the full type is internally generated. + + Full_Decl := New_Copy_Tree (N); + Full_Der := New_Copy (Derived_Type); + Set_Comes_From_Source (Full_Decl, False); + Set_Comes_From_Source (Full_Der, False); + + Insert_After (N, Full_Decl); + + else + -- If this is a completion, the full view being built is + -- itself private. We build a subtype of the parent with + -- the same constraints as this full view, to convey to the + -- back end the constrained components and the size of this + -- subtype. If the parent is constrained, its full view can + -- serve as the underlying full view of the derived type. + + if No (Discriminant_Specifications (N)) then + if Nkind (Subtype_Indication (Type_Definition (N))) = + N_Subtype_Indication + then + Build_Underlying_Full_View (N, Derived_Type, Parent_Type); + + elsif Is_Constrained (Full_View (Parent_Type)) then + Set_Underlying_Full_View (Derived_Type, + Full_View (Parent_Type)); + end if; + + else + -- If there are new discriminants, the parent subtype is + -- constrained by them, but it is not clear how to build + -- the underlying_full_view in this case ??? + + null; + end if; + end if; + end if; + + -- Build partial view of derived type from partial view of parent + + Build_Derived_Record_Type + (N, Parent_Type, Derived_Type, Derive_Subps); + + if Present (Full_View (Parent_Type)) + and then not Is_Completion + then + if not In_Open_Scopes (Par_Scope) + or else not In_Same_Source_Unit (N, Parent_Type) + then + -- Swap partial and full views temporarily + + Install_Private_Declarations (Par_Scope); + Install_Visible_Declarations (Par_Scope); + Swapped := True; + end if; + + -- Build full view of derived type from full view of parent which + -- is now installed. Subprograms have been derived on the partial + -- view, the completion does not derive them anew. + + if not Is_Tagged_Type (Parent_Type) then + + -- If the parent is itself derived from another private type, + -- installing the private declarations has not affected its + -- privacy status, so use its own full view explicitly. + + if Is_Private_Type (Parent_Type) then + Build_Derived_Record_Type + (Full_Decl, Full_View (Parent_Type), Full_Der, False); + else + Build_Derived_Record_Type + (Full_Decl, Parent_Type, Full_Der, False); + end if; + + else + -- If full view of parent is tagged, the completion + -- inherits the proper primitive operations. + + Set_Defining_Identifier (Full_Decl, Full_Der); + Build_Derived_Record_Type + (Full_Decl, Parent_Type, Full_Der, Derive_Subps); + Set_Analyzed (Full_Decl); + end if; + + if Swapped then + Uninstall_Declarations (Par_Scope); + + if In_Open_Scopes (Par_Scope) then + Install_Visible_Declarations (Par_Scope); + end if; + end if; + + Der_Base := Base_Type (Derived_Type); + Set_Full_View (Derived_Type, Full_Der); + Set_Full_View (Der_Base, Base_Type (Full_Der)); + + -- Copy the discriminant list from full view to the partial views + -- (base type and its subtype). Gigi requires that the partial + -- and full views have the same discriminants. + + -- Note that since the partial view is pointing to discriminants + -- in the full view, their scope will be that of the full view. + -- This might cause some front end problems and need + -- adjustment??? + + Discr := First_Discriminant (Base_Type (Full_Der)); + Set_First_Entity (Der_Base, Discr); + + loop + Last_Discr := Discr; + Next_Discriminant (Discr); + exit when No (Discr); + end loop; + + Set_Last_Entity (Der_Base, Last_Discr); + + Set_First_Entity (Derived_Type, First_Entity (Der_Base)); + Set_Last_Entity (Derived_Type, Last_Entity (Der_Base)); + Set_Stored_Constraint (Full_Der, Stored_Constraint (Derived_Type)); + + else + -- If this is a completion, the derived type stays private + -- and there is no need to create a further full view, except + -- in the unusual case when the derivation is nested within a + -- child unit, see below. + + null; + end if; + + elsif Present (Full_View (Parent_Type)) + and then Has_Discriminants (Full_View (Parent_Type)) + then + if Has_Unknown_Discriminants (Parent_Type) + and then Nkind (Subtype_Indication (Type_Definition (N))) + = N_Subtype_Indication + then + Error_Msg_N + ("cannot constrain type with unknown discriminants", + Subtype_Indication (Type_Definition (N))); + return; + end if; + + -- If full view of parent is a record type, Build full view as + -- a derivation from the parent's full view. Partial view remains + -- private. For code generation and linking, the full view must + -- have the same public status as the partial one. This full view + -- is only needed if the parent type is in an enclosing scope, so + -- that the full view may actually become visible, e.g. in a child + -- unit. This is both more efficient, and avoids order of freezing + -- problems with the added entities. + + if not Is_Private_Type (Full_View (Parent_Type)) + and then (In_Open_Scopes (Scope (Parent_Type))) + then + Full_Der := Make_Defining_Identifier (Sloc (Derived_Type), + Chars (Derived_Type)); + Set_Is_Itype (Full_Der); + Set_Has_Private_Declaration (Full_Der); + Set_Has_Private_Declaration (Derived_Type); + Set_Associated_Node_For_Itype (Full_Der, N); + Set_Parent (Full_Der, Parent (Derived_Type)); + Set_Full_View (Derived_Type, Full_Der); + Set_Is_Public (Full_Der, Is_Public (Derived_Type)); + Full_P := Full_View (Parent_Type); + Exchange_Declarations (Parent_Type); + Copy_And_Build; + Exchange_Declarations (Full_P); + + else + Build_Derived_Record_Type + (N, Full_View (Parent_Type), Derived_Type, + Derive_Subps => False); + end if; + + -- In any case, the primitive operations are inherited from + -- the parent type, not from the internal full view. + + Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type)); + + if Derive_Subps then + Derive_Subprograms (Parent_Type, Derived_Type); + end if; + + else + -- Untagged type, No discriminants on either view + + if Nkind (Subtype_Indication (Type_Definition (N))) = + N_Subtype_Indication + then + Error_Msg_N + ("illegal constraint on type without discriminants", N); + end if; + + if Present (Discriminant_Specifications (N)) + and then Present (Full_View (Parent_Type)) + and then not Is_Tagged_Type (Full_View (Parent_Type)) + then + Error_Msg_N + ("cannot add discriminants to untagged type", N); + end if; + + Set_Stored_Constraint (Derived_Type, No_Elist); + Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type)); + Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type)); + Set_Has_Controlled_Component + (Derived_Type, Has_Controlled_Component + (Parent_Type)); + + -- Direct controlled types do not inherit Finalize_Storage_Only flag + + if not Is_Controlled (Parent_Type) then + Set_Finalize_Storage_Only + (Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type)); + end if; + + -- Construct the implicit full view by deriving from full view of + -- the parent type. In order to get proper visibility, we install + -- the parent scope and its declarations. + + -- ??? if the parent is untagged private and its completion is + -- tagged, this mechanism will not work because we cannot derive + -- from the tagged full view unless we have an extension + + if Present (Full_View (Parent_Type)) + and then not Is_Tagged_Type (Full_View (Parent_Type)) + and then not Is_Completion + then + Full_Der := + Make_Defining_Identifier (Sloc (Derived_Type), + Chars => Chars (Derived_Type)); + Set_Is_Itype (Full_Der); + Set_Has_Private_Declaration (Full_Der); + Set_Has_Private_Declaration (Derived_Type); + Set_Associated_Node_For_Itype (Full_Der, N); + Set_Parent (Full_Der, Parent (Derived_Type)); + Set_Full_View (Derived_Type, Full_Der); + + if not In_Open_Scopes (Par_Scope) then + Install_Private_Declarations (Par_Scope); + Install_Visible_Declarations (Par_Scope); + Copy_And_Build; + Uninstall_Declarations (Par_Scope); + + -- If parent scope is open and in another unit, and parent has a + -- completion, then the derivation is taking place in the visible + -- part of a child unit. In that case retrieve the full view of + -- the parent momentarily. + + elsif not In_Same_Source_Unit (N, Parent_Type) then + Full_P := Full_View (Parent_Type); + Exchange_Declarations (Parent_Type); + Copy_And_Build; + Exchange_Declarations (Full_P); + + -- Otherwise it is a local derivation + + else + Copy_And_Build; + end if; + + Set_Scope (Full_Der, Current_Scope); + Set_Is_First_Subtype (Full_Der, + Is_First_Subtype (Derived_Type)); + Set_Has_Size_Clause (Full_Der, False); + Set_Has_Alignment_Clause (Full_Der, False); + Set_Next_Entity (Full_Der, Empty); + Set_Has_Delayed_Freeze (Full_Der); + Set_Is_Frozen (Full_Der, False); + Set_Freeze_Node (Full_Der, Empty); + Set_Depends_On_Private (Full_Der, + Has_Private_Component (Full_Der)); + Set_Public_Status (Full_Der); + end if; + end if; + + Set_Has_Unknown_Discriminants (Derived_Type, + Has_Unknown_Discriminants (Parent_Type)); + + if Is_Private_Type (Derived_Type) then + Set_Private_Dependents (Derived_Type, New_Elmt_List); + end if; + + if Is_Private_Type (Parent_Type) + and then Base_Type (Parent_Type) = Parent_Type + and then In_Open_Scopes (Scope (Parent_Type)) + then + Append_Elmt (Derived_Type, Private_Dependents (Parent_Type)); + + if Is_Child_Unit (Scope (Current_Scope)) + and then Is_Completion + and then In_Private_Part (Current_Scope) + and then Scope (Parent_Type) /= Current_Scope + then + -- This is the unusual case where a type completed by a private + -- derivation occurs within a package nested in a child unit, + -- and the parent is declared in an ancestor. In this case, the + -- full view of the parent type will become visible in the body + -- of the enclosing child, and only then will the current type + -- be possibly non-private. We build a underlying full view that + -- will be installed when the enclosing child body is compiled. + + declare + IR : constant Node_Id := Make_Itype_Reference (Sloc (N)); + + begin + Full_Der := + Make_Defining_Identifier (Sloc (Derived_Type), + Chars (Derived_Type)); + Set_Is_Itype (Full_Der); + Set_Itype (IR, Full_Der); + Insert_After (N, IR); + + -- The full view will be used to swap entities on entry/exit + -- to the body, and must appear in the entity list for the + -- package. + + Append_Entity (Full_Der, Scope (Derived_Type)); + Set_Has_Private_Declaration (Full_Der); + Set_Has_Private_Declaration (Derived_Type); + Set_Associated_Node_For_Itype (Full_Der, N); + Set_Parent (Full_Der, Parent (Derived_Type)); + Full_P := Full_View (Parent_Type); + Exchange_Declarations (Parent_Type); + Copy_And_Build; + Exchange_Declarations (Full_P); + Set_Underlying_Full_View (Derived_Type, Full_Der); + end; + end if; + end if; + end Build_Derived_Private_Type; + + ------------------------------- + -- Build_Derived_Record_Type -- + ------------------------------- + + -- 1. INTRODUCTION + + -- Ideally we would like to use the same model of type derivation for + -- tagged and untagged record types. Unfortunately this is not quite + -- possible because the semantics of representation clauses is different + -- for tagged and untagged records under inheritance. Consider the + -- following: + + -- type R (...) is [tagged] record ... end record; + -- type T (...) is new R (...) [with ...]; + + -- The representation clauses of T can specify a completely different + -- record layout from R's. Hence the same component can be placed in + -- two very different positions in objects of type T and R. If R and T + -- are tagged types, representation clauses for T can only specify the + -- layout of non inherited components, thus components that are common + -- in R and T have the same position in objects of type R and T. + + -- This has two implications. The first is that the entire tree for R's + -- declaration needs to be copied for T in the untagged case, so that T + -- can be viewed as a record type of its own with its own representation + -- clauses. The second implication is the way we handle discriminants. + -- Specifically, in the untagged case we need a way to communicate to Gigi + -- what are the real discriminants in the record, while for the semantics + -- we need to consider those introduced by the user to rename the + -- discriminants in the parent type. This is handled by introducing the + -- notion of stored discriminants. See below for more. + + -- Fortunately the way regular components are inherited can be handled in + -- the same way in tagged and untagged types. + + -- To complicate things a bit more the private view of a private extension + -- cannot be handled in the same way as the full view (for one thing the + -- semantic rules are somewhat different). We will explain what differs + -- below. + + -- 2. DISCRIMINANTS UNDER INHERITANCE + + -- The semantic rules governing the discriminants of derived types are + -- quite subtle. + + -- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new + -- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART] + + -- If parent type has discriminants, then the discriminants that are + -- declared in the derived type are [3.4 (11)]: + + -- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if + -- there is one; + + -- o Otherwise, each discriminant of the parent type (implicitly declared + -- in the same order with the same specifications). In this case, the + -- discriminants are said to be "inherited", or if unknown in the parent + -- are also unknown in the derived type. + + -- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]: + + -- o The parent subtype shall be constrained; + + -- o If the parent type is not a tagged type, then each discriminant of + -- the derived type shall be used in the constraint defining a parent + -- subtype [Implementation note: this ensures that the new discriminant + -- can share storage with an existing discriminant.]. + + -- For the derived type each discriminant of the parent type is either + -- inherited, constrained to equal some new discriminant of the derived + -- type, or constrained to the value of an expression. + + -- When inherited or constrained to equal some new discriminant, the + -- parent discriminant and the discriminant of the derived type are said + -- to "correspond". + + -- If a discriminant of the parent type is constrained to a specific value + -- in the derived type definition, then the discriminant is said to be + -- "specified" by that derived type definition. + + -- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES + + -- We have spoken about stored discriminants in point 1 (introduction) + -- above. There are two sort of stored discriminants: implicit and + -- explicit. As long as the derived type inherits the same discriminants as + -- the root record type, stored discriminants are the same as regular + -- discriminants, and are said to be implicit. However, if any discriminant + -- in the root type was renamed in the derived type, then the derived + -- type will contain explicit stored discriminants. Explicit stored + -- discriminants are discriminants in addition to the semantically visible + -- discriminants defined for the derived type. Stored discriminants are + -- used by Gigi to figure out what are the physical discriminants in + -- objects of the derived type (see precise definition in einfo.ads). + -- As an example, consider the following: + + -- type R (D1, D2, D3 : Int) is record ... end record; + -- type T1 is new R; + -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1); + -- type T3 is new T2; + -- type T4 (Y : Int) is new T3 (Y, 99); + + -- The following table summarizes the discriminants and stored + -- discriminants in R and T1 through T4. + + -- Type Discrim Stored Discrim Comment + -- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R + -- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1 + -- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2 + -- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3 + -- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4 + + -- Field Corresponding_Discriminant (abbreviated CD below) allows us to + -- find the corresponding discriminant in the parent type, while + -- Original_Record_Component (abbreviated ORC below), the actual physical + -- component that is renamed. Finally the field Is_Completely_Hidden + -- (abbreviated ICH below) is set for all explicit stored discriminants + -- (see einfo.ads for more info). For the above example this gives: + + -- Discrim CD ORC ICH + -- ^^^^^^^ ^^ ^^^ ^^^ + -- D1 in R empty itself no + -- D2 in R empty itself no + -- D3 in R empty itself no + + -- D1 in T1 D1 in R itself no + -- D2 in T1 D2 in R itself no + -- D3 in T1 D3 in R itself no + + -- X1 in T2 D3 in T1 D3 in T2 no + -- X2 in T2 D1 in T1 D1 in T2 no + -- D1 in T2 empty itself yes + -- D2 in T2 empty itself yes + -- D3 in T2 empty itself yes + + -- X1 in T3 X1 in T2 D3 in T3 no + -- X2 in T3 X2 in T2 D1 in T3 no + -- D1 in T3 empty itself yes + -- D2 in T3 empty itself yes + -- D3 in T3 empty itself yes + + -- Y in T4 X1 in T3 D3 in T3 no + -- D1 in T3 empty itself yes + -- D2 in T3 empty itself yes + -- D3 in T3 empty itself yes + + -- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES + + -- Type derivation for tagged types is fairly straightforward. if no + -- discriminants are specified by the derived type, these are inherited + -- from the parent. No explicit stored discriminants are ever necessary. + -- The only manipulation that is done to the tree is that of adding a + -- _parent field with parent type and constrained to the same constraint + -- specified for the parent in the derived type definition. For instance: + + -- type R (D1, D2, D3 : Int) is tagged record ... end record; + -- type T1 is new R with null record; + -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record; + + -- are changed into: + + -- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record + -- _parent : R (D1, D2, D3); + -- end record; + + -- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record + -- _parent : T1 (X2, 88, X1); + -- end record; + + -- The discriminants actually present in R, T1 and T2 as well as their CD, + -- ORC and ICH fields are: + + -- Discrim CD ORC ICH + -- ^^^^^^^ ^^ ^^^ ^^^ + -- D1 in R empty itself no + -- D2 in R empty itself no + -- D3 in R empty itself no + + -- D1 in T1 D1 in R D1 in R no + -- D2 in T1 D2 in R D2 in R no + -- D3 in T1 D3 in R D3 in R no + + -- X1 in T2 D3 in T1 D3 in R no + -- X2 in T2 D1 in T1 D1 in R no + + -- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS + -- + -- Regardless of whether we dealing with a tagged or untagged type + -- we will transform all derived type declarations of the form + -- + -- type T is new R (...) [with ...]; + -- or + -- subtype S is R (...); + -- type T is new S [with ...]; + -- into + -- type BT is new R [with ...]; + -- subtype T is BT (...); + -- + -- That is, the base derived type is constrained only if it has no + -- discriminants. The reason for doing this is that GNAT's semantic model + -- assumes that a base type with discriminants is unconstrained. + -- + -- Note that, strictly speaking, the above transformation is not always + -- correct. Consider for instance the following excerpt from ACVC b34011a: + -- + -- procedure B34011A is + -- type REC (D : integer := 0) is record + -- I : Integer; + -- end record; + + -- package P is + -- type T6 is new Rec; + -- function F return T6; + -- end P; + + -- use P; + -- package Q6 is + -- type U is new T6 (Q6.F.I); -- ERROR: Q6.F. + -- end Q6; + -- + -- The definition of Q6.U is illegal. However transforming Q6.U into + + -- type BaseU is new T6; + -- subtype U is BaseU (Q6.F.I) + + -- turns U into a legal subtype, which is incorrect. To avoid this problem + -- we always analyze the constraint (in this case (Q6.F.I)) before applying + -- the transformation described above. + + -- There is another instance where the above transformation is incorrect. + -- Consider: + + -- package Pack is + -- type Base (D : Integer) is tagged null record; + -- procedure P (X : Base); + + -- type Der is new Base (2) with null record; + -- procedure P (X : Der); + -- end Pack; + + -- Then the above transformation turns this into + + -- type Der_Base is new Base with null record; + -- -- procedure P (X : Base) is implicitly inherited here + -- -- as procedure P (X : Der_Base). + + -- subtype Der is Der_Base (2); + -- procedure P (X : Der); + -- -- The overriding of P (X : Der_Base) is illegal since we + -- -- have a parameter conformance problem. + + -- To get around this problem, after having semantically processed Der_Base + -- and the rewritten subtype declaration for Der, we copy Der_Base field + -- Discriminant_Constraint from Der so that when parameter conformance is + -- checked when P is overridden, no semantic errors are flagged. + + -- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS + + -- Regardless of whether we are dealing with a tagged or untagged type + -- we will transform all derived type declarations of the form + + -- type R (D1, .., Dn : ...) is [tagged] record ...; + -- type T is new R [with ...]; + -- into + -- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...]; + + -- The reason for such transformation is that it allows us to implement a + -- very clean form of component inheritance as explained below. + + -- Note that this transformation is not achieved by direct tree rewriting + -- and manipulation, but rather by redoing the semantic actions that the + -- above transformation will entail. This is done directly in routine + -- Inherit_Components. + + -- 7. TYPE DERIVATION AND COMPONENT INHERITANCE + + -- In both tagged and untagged derived types, regular non discriminant + -- components are inherited in the derived type from the parent type. In + -- the absence of discriminants component, inheritance is straightforward + -- as components can simply be copied from the parent. + + -- If the parent has discriminants, inheriting components constrained with + -- these discriminants requires caution. Consider the following example: + + -- type R (D1, D2 : Positive) is [tagged] record + -- S : String (D1 .. D2); + -- end record; + + -- type T1 is new R [with null record]; + -- type T2 (X : positive) is new R (1, X) [with null record]; + + -- As explained in 6. above, T1 is rewritten as + -- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record]; + -- which makes the treatment for T1 and T2 identical. + + -- What we want when inheriting S, is that references to D1 and D2 in R are + -- replaced with references to their correct constraints, ie D1 and D2 in + -- T1 and 1 and X in T2. So all R's discriminant references are replaced + -- with either discriminant references in the derived type or expressions. + -- This replacement is achieved as follows: before inheriting R's + -- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is + -- created in the scope of T1 (resp. scope of T2) so that discriminants D1 + -- and D2 of T1 are visible (resp. discriminant X of T2 is visible). + -- For T2, for instance, this has the effect of replacing String (D1 .. D2) + -- by String (1 .. X). + + -- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS + + -- We explain here the rules governing private type extensions relevant to + -- type derivation. These rules are explained on the following example: + + -- type D [(...)] is new A [(...)] with private; <-- partial view + -- type D [(...)] is new P [(...)] with null record; <-- full view + + -- Type A is called the ancestor subtype of the private extension. + -- Type P is the parent type of the full view of the private extension. It + -- must be A or a type derived from A. + + -- The rules concerning the discriminants of private type extensions are + -- [7.3(10-13)]: + + -- o If a private extension inherits known discriminants from the ancestor + -- subtype, then the full view shall also inherit its discriminants from + -- the ancestor subtype and the parent subtype of the full view shall be + -- constrained if and only if the ancestor subtype is constrained. + + -- o If a partial view has unknown discriminants, then the full view may + -- define a definite or an indefinite subtype, with or without + -- discriminants. + + -- o If a partial view has neither known nor unknown discriminants, then + -- the full view shall define a definite subtype. + + -- o If the ancestor subtype of a private extension has constrained + -- discriminants, then the parent subtype of the full view shall impose a + -- statically matching constraint on those discriminants. + + -- This means that only the following forms of private extensions are + -- allowed: + + -- type D is new A with private; <-- partial view + -- type D is new P with null record; <-- full view + + -- If A has no discriminants than P has no discriminants, otherwise P must + -- inherit A's discriminants. + + -- type D is new A (...) with private; <-- partial view + -- type D is new P (:::) with null record; <-- full view + + -- P must inherit A's discriminants and (...) and (:::) must statically + -- match. + + -- subtype A is R (...); + -- type D is new A with private; <-- partial view + -- type D is new P with null record; <-- full view + + -- P must have inherited R's discriminants and must be derived from A or + -- any of its subtypes. + + -- type D (..) is new A with private; <-- partial view + -- type D (..) is new P [(:::)] with null record; <-- full view + + -- No specific constraints on P's discriminants or constraint (:::). + -- Note that A can be unconstrained, but the parent subtype P must either + -- be constrained or (:::) must be present. + + -- type D (..) is new A [(...)] with private; <-- partial view + -- type D (..) is new P [(:::)] with null record; <-- full view + + -- P's constraints on A's discriminants must statically match those + -- imposed by (...). + + -- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS + + -- The full view of a private extension is handled exactly as described + -- above. The model chose for the private view of a private extension is + -- the same for what concerns discriminants (ie they receive the same + -- treatment as in the tagged case). However, the private view of the + -- private extension always inherits the components of the parent base, + -- without replacing any discriminant reference. Strictly speaking this is + -- incorrect. However, Gigi never uses this view to generate code so this + -- is a purely semantic issue. In theory, a set of transformations similar + -- to those given in 5. and 6. above could be applied to private views of + -- private extensions to have the same model of component inheritance as + -- for non private extensions. However, this is not done because it would + -- further complicate private type processing. Semantically speaking, this + -- leaves us in an uncomfortable situation. As an example consider: + + -- package Pack is + -- type R (D : integer) is tagged record + -- S : String (1 .. D); + -- end record; + -- procedure P (X : R); + -- type T is new R (1) with private; + -- private + -- type T is new R (1) with null record; + -- end; + + -- This is transformed into: + + -- package Pack is + -- type R (D : integer) is tagged record + -- S : String (1 .. D); + -- end record; + -- procedure P (X : R); + -- type T is new R (1) with private; + -- private + -- type BaseT is new R with null record; + -- subtype T is BaseT (1); + -- end; + + -- (strictly speaking the above is incorrect Ada) + + -- From the semantic standpoint the private view of private extension T + -- should be flagged as constrained since one can clearly have + -- + -- Obj : T; + -- + -- in a unit withing Pack. However, when deriving subprograms for the + -- private view of private extension T, T must be seen as unconstrained + -- since T has discriminants (this is a constraint of the current + -- subprogram derivation model). Thus, when processing the private view of + -- a private extension such as T, we first mark T as unconstrained, we + -- process it, we perform program derivation and just before returning from + -- Build_Derived_Record_Type we mark T as constrained. + + -- ??? Are there are other uncomfortable cases that we will have to + -- deal with. + + -- 10. RECORD_TYPE_WITH_PRIVATE complications + + -- Types that are derived from a visible record type and have a private + -- extension present other peculiarities. They behave mostly like private + -- types, but if they have primitive operations defined, these will not + -- have the proper signatures for further inheritance, because other + -- primitive operations will use the implicit base that we define for + -- private derivations below. This affect subprogram inheritance (see + -- Derive_Subprograms for details). We also derive the implicit base from + -- the base type of the full view, so that the implicit base is a record + -- type and not another private type, This avoids infinite loops. + + procedure Build_Derived_Record_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Derive_Subps : Boolean := True) + is + Loc : constant Source_Ptr := Sloc (N); + Parent_Base : Entity_Id; + Type_Def : Node_Id; + Indic : Node_Id; + Discrim : Entity_Id; + Last_Discrim : Entity_Id; + Constrs : Elist_Id; + + Discs : Elist_Id := New_Elmt_List; + -- An empty Discs list means that there were no constraints in the + -- subtype indication or that there was an error processing it. + + Assoc_List : Elist_Id; + New_Discrs : Elist_Id; + New_Base : Entity_Id; + New_Decl : Node_Id; + New_Indic : Node_Id; + + Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type); + Discriminant_Specs : constant Boolean := + Present (Discriminant_Specifications (N)); + Private_Extension : constant Boolean := + (Nkind (N) = N_Private_Extension_Declaration); + + Constraint_Present : Boolean; + Has_Interfaces : Boolean := False; + Inherit_Discrims : Boolean := False; + Tagged_Partial_View : Entity_Id; + Save_Etype : Entity_Id; + Save_Discr_Constr : Elist_Id; + Save_Next_Entity : Entity_Id; + + begin + if Ekind (Parent_Type) = E_Record_Type_With_Private + and then Present (Full_View (Parent_Type)) + and then Has_Discriminants (Parent_Type) + then + Parent_Base := Base_Type (Full_View (Parent_Type)); + else + Parent_Base := Base_Type (Parent_Type); + end if; + + -- Before we start the previously documented transformations, here is + -- a little fix for size and alignment of tagged types. Normally when + -- we derive type D from type P, we copy the size and alignment of P + -- as the default for D, and in the absence of explicit representation + -- clauses for D, the size and alignment are indeed the same as the + -- parent. + + -- But this is wrong for tagged types, since fields may be added, + -- and the default size may need to be larger, and the default + -- alignment may need to be larger. + + -- We therefore reset the size and alignment fields in the tagged + -- case. Note that the size and alignment will in any case be at + -- least as large as the parent type (since the derived type has + -- a copy of the parent type in the _parent field) + + if Is_Tagged then + Init_Size_Align (Derived_Type); + end if; + + -- STEP 0a: figure out what kind of derived type declaration we have + + if Private_Extension then + Type_Def := N; + Set_Ekind (Derived_Type, E_Record_Type_With_Private); + + else + Type_Def := Type_Definition (N); + + -- Ekind (Parent_Base) in not necessarily E_Record_Type since + -- Parent_Base can be a private type or private extension. However, + -- for tagged types with an extension the newly added fields are + -- visible and hence the Derived_Type is always an E_Record_Type. + -- (except that the parent may have its own private fields). + -- For untagged types we preserve the Ekind of the Parent_Base. + + if Present (Record_Extension_Part (Type_Def)) then + Set_Ekind (Derived_Type, E_Record_Type); + else + Set_Ekind (Derived_Type, Ekind (Parent_Base)); + end if; + end if; + + -- Indic can either be an N_Identifier if the subtype indication + -- contains no constraint or an N_Subtype_Indication if the subtype + -- indication has a constraint. + + Indic := Subtype_Indication (Type_Def); + Constraint_Present := (Nkind (Indic) = N_Subtype_Indication); + + -- Check that the type has visible discriminants. The type may be + -- a private type with unknown discriminants whose full view has + -- discriminants which are invisible. + + if Constraint_Present then + if not Has_Discriminants (Parent_Base) + or else + (Has_Unknown_Discriminants (Parent_Base) + and then Is_Private_Type (Parent_Base)) + then + Error_Msg_N + ("invalid constraint: type has no discriminant", + Constraint (Indic)); + + Constraint_Present := False; + Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic))); + + elsif Is_Constrained (Parent_Type) then + Error_Msg_N + ("invalid constraint: parent type is already constrained", + Constraint (Indic)); + + Constraint_Present := False; + Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic))); + end if; + end if; + + -- STEP 0b: If needed, apply transformation given in point 5. above + + if not Private_Extension + and then Has_Discriminants (Parent_Type) + and then not Discriminant_Specs + and then (Is_Constrained (Parent_Type) or else Constraint_Present) + then + -- First, we must analyze the constraint (see comment in point 5.) + + if Constraint_Present then + New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic); + + if Has_Discriminants (Derived_Type) + and then Has_Private_Declaration (Derived_Type) + and then Present (Discriminant_Constraint (Derived_Type)) + then + -- Verify that constraints of the full view conform to those + -- given in partial view. + + declare + C1, C2 : Elmt_Id; + + begin + C1 := First_Elmt (New_Discrs); + C2 := First_Elmt (Discriminant_Constraint (Derived_Type)); + while Present (C1) and then Present (C2) loop + if not + Fully_Conformant_Expressions (Node (C1), Node (C2)) + then + Error_Msg_N ( + "constraint not conformant to previous declaration", + Node (C1)); + end if; + + Next_Elmt (C1); + Next_Elmt (C2); + end loop; + end; + end if; + end if; + + -- Insert and analyze the declaration for the unconstrained base type + + New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B'); + + New_Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => New_Base, + Type_Definition => + Make_Derived_Type_Definition (Loc, + Abstract_Present => Abstract_Present (Type_Def), + Subtype_Indication => + New_Occurrence_Of (Parent_Base, Loc), + Record_Extension_Part => + Relocate_Node (Record_Extension_Part (Type_Def)))); + + Set_Parent (New_Decl, Parent (N)); + Mark_Rewrite_Insertion (New_Decl); + Insert_Before (N, New_Decl); + + -- Note that this call passes False for the Derive_Subps parameter + -- because subprogram derivation is deferred until after creating + -- the subtype (see below). + + Build_Derived_Type + (New_Decl, Parent_Base, New_Base, + Is_Completion => True, Derive_Subps => False); + + -- ??? This needs re-examination to determine whether the + -- above call can simply be replaced by a call to Analyze. + + Set_Analyzed (New_Decl); + + -- Insert and analyze the declaration for the constrained subtype + + if Constraint_Present then + New_Indic := + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Occurrence_Of (New_Base, Loc), + Constraint => Relocate_Node (Constraint (Indic))); + + else + declare + Constr_List : constant List_Id := New_List; + C : Elmt_Id; + Expr : Node_Id; + + begin + C := First_Elmt (Discriminant_Constraint (Parent_Type)); + while Present (C) loop + Expr := Node (C); + + -- It is safe here to call New_Copy_Tree since + -- Force_Evaluation was called on each constraint in + -- Build_Discriminant_Constraints. + + Append (New_Copy_Tree (Expr), To => Constr_List); + + Next_Elmt (C); + end loop; + + New_Indic := + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Occurrence_Of (New_Base, Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, Constr_List)); + end; + end if; + + Rewrite (N, + Make_Subtype_Declaration (Loc, + Defining_Identifier => Derived_Type, + Subtype_Indication => New_Indic)); + + Analyze (N); + + -- Derivation of subprograms must be delayed until the full subtype + -- has been established to ensure proper overriding of subprograms + -- inherited by full types. If the derivations occurred as part of + -- the call to Build_Derived_Type above, then the check for type + -- conformance would fail because earlier primitive subprograms + -- could still refer to the full type prior the change to the new + -- subtype and hence would not match the new base type created here. + + Derive_Subprograms (Parent_Type, Derived_Type); + + -- For tagged types the Discriminant_Constraint of the new base itype + -- is inherited from the first subtype so that no subtype conformance + -- problem arise when the first subtype overrides primitive + -- operations inherited by the implicit base type. + + if Is_Tagged then + Set_Discriminant_Constraint + (New_Base, Discriminant_Constraint (Derived_Type)); + end if; + + return; + end if; + + -- If we get here Derived_Type will have no discriminants or it will be + -- a discriminated unconstrained base type. + + -- STEP 1a: perform preliminary actions/checks for derived tagged types + + if Is_Tagged then + + -- The parent type is frozen for non-private extensions (RM 13.14(7)) + + if not Private_Extension then + Freeze_Before (N, Parent_Type); + end if; + + -- In Ada 2005 (AI-344), the restriction that a derived tagged type + -- cannot be declared at a deeper level than its parent type is + -- removed. The check on derivation within a generic body is also + -- relaxed, but there's a restriction that a derived tagged type + -- cannot be declared in a generic body if it's derived directly + -- or indirectly from a formal type of that generic. + + if Ada_Version >= Ada_05 then + if Present (Enclosing_Generic_Body (Derived_Type)) then + declare + Ancestor_Type : Entity_Id; + + begin + -- Check to see if any ancestor of the derived type is a + -- formal type. + + Ancestor_Type := Parent_Type; + while not Is_Generic_Type (Ancestor_Type) + and then Etype (Ancestor_Type) /= Ancestor_Type + loop + Ancestor_Type := Etype (Ancestor_Type); + end loop; + + -- If the derived type does have a formal type as an + -- ancestor, then it's an error if the derived type is + -- declared within the body of the generic unit that + -- declares the formal type in its generic formal part. It's + -- sufficient to check whether the ancestor type is declared + -- inside the same generic body as the derived type (such as + -- within a nested generic spec), in which case the + -- derivation is legal. If the formal type is declared + -- outside of that generic body, then it's guaranteed that + -- the derived type is declared within the generic body of + -- the generic unit declaring the formal type. + + if Is_Generic_Type (Ancestor_Type) + and then Enclosing_Generic_Body (Ancestor_Type) /= + Enclosing_Generic_Body (Derived_Type) + then + Error_Msg_NE + ("parent type of& must not be descendant of formal type" + & " of an enclosing generic body", + Indic, Derived_Type); + end if; + end; + end if; + + elsif Type_Access_Level (Derived_Type) /= + Type_Access_Level (Parent_Type) + and then not Is_Generic_Type (Derived_Type) + then + if Is_Controlled (Parent_Type) then + Error_Msg_N + ("controlled type must be declared at the library level", + Indic); + else + Error_Msg_N + ("type extension at deeper accessibility level than parent", + Indic); + end if; + + else + declare + GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type); + + begin + if Present (GB) + and then GB /= Enclosing_Generic_Body (Parent_Base) + then + Error_Msg_NE + ("parent type of& must not be outside generic body" + & " ('R'M 3.9.1(4))", + Indic, Derived_Type); + end if; + end; + end if; + end if; + + -- Ada 2005 (AI-251) + + if Ada_Version = Ada_05 + and then Is_Tagged + then + + -- "The declaration of a specific descendant of an interface type + -- freezes the interface type" (RM 13.14). + + declare + Iface : Node_Id; + begin + if Is_Non_Empty_List (Interface_List (Type_Def)) then + Iface := First (Interface_List (Type_Def)); + while Present (Iface) loop + Freeze_Before (N, Etype (Iface)); + Next (Iface); + end loop; + end if; + end; + end if; + + -- STEP 1b : preliminary cleanup of the full view of private types + + -- If the type is already marked as having discriminants, then it's the + -- completion of a private type or private extension and we need to + -- retain the discriminants from the partial view if the current + -- declaration has Discriminant_Specifications so that we can verify + -- conformance. However, we must remove any existing components that + -- were inherited from the parent (and attached in Copy_And_Swap) + -- because the full type inherits all appropriate components anyway, and + -- we do not want the partial view's components interfering. + + if Has_Discriminants (Derived_Type) and then Discriminant_Specs then + Discrim := First_Discriminant (Derived_Type); + loop + Last_Discrim := Discrim; + Next_Discriminant (Discrim); + exit when No (Discrim); + end loop; + + Set_Last_Entity (Derived_Type, Last_Discrim); + + -- In all other cases wipe out the list of inherited components (even + -- inherited discriminants), it will be properly rebuilt here. + + else + Set_First_Entity (Derived_Type, Empty); + Set_Last_Entity (Derived_Type, Empty); + end if; + + -- STEP 1c: Initialize some flags for the Derived_Type + + -- The following flags must be initialized here so that + -- Process_Discriminants can check that discriminants of tagged types + -- do not have a default initial value and that access discriminants + -- are only specified for limited records. For completeness, these + -- flags are also initialized along with all the other flags below. + + -- AI-419: limitedness is not inherited from an interface parent + + Set_Is_Tagged_Type (Derived_Type, Is_Tagged); + Set_Is_Limited_Record (Derived_Type, + Is_Limited_Record (Parent_Type) + and then not Is_Interface (Parent_Type)); + + -- STEP 2a: process discriminants of derived type if any + + New_Scope (Derived_Type); + + if Discriminant_Specs then + Set_Has_Unknown_Discriminants (Derived_Type, False); + + -- The following call initializes fields Has_Discriminants and + -- Discriminant_Constraint, unless we are processing the completion + -- of a private type declaration. + + Check_Or_Process_Discriminants (N, Derived_Type); + + -- For non-tagged types the constraint on the Parent_Type must be + -- present and is used to rename the discriminants. + + if not Is_Tagged and then not Has_Discriminants (Parent_Type) then + Error_Msg_N ("untagged parent must have discriminants", Indic); + + elsif not Is_Tagged and then not Constraint_Present then + Error_Msg_N + ("discriminant constraint needed for derived untagged records", + Indic); + + -- Otherwise the parent subtype must be constrained unless we have a + -- private extension. + + elsif not Constraint_Present + and then not Private_Extension + and then not Is_Constrained (Parent_Type) + then + Error_Msg_N + ("unconstrained type not allowed in this context", Indic); + + elsif Constraint_Present then + -- The following call sets the field Corresponding_Discriminant + -- for the discriminants in the Derived_Type. + + Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True); + + -- For untagged types all new discriminants must rename + -- discriminants in the parent. For private extensions new + -- discriminants cannot rename old ones (implied by [7.3(13)]). + + Discrim := First_Discriminant (Derived_Type); + while Present (Discrim) loop + if not Is_Tagged + and then No (Corresponding_Discriminant (Discrim)) + then + Error_Msg_N + ("new discriminants must constrain old ones", Discrim); + + elsif Private_Extension + and then Present (Corresponding_Discriminant (Discrim)) + then + Error_Msg_N + ("only static constraints allowed for parent" + & " discriminants in the partial view", Indic); + exit; + end if; + + -- If a new discriminant is used in the constraint, then its + -- subtype must be statically compatible with the parent + -- discriminant's subtype (3.7(15)). + + if Present (Corresponding_Discriminant (Discrim)) + and then + not Subtypes_Statically_Compatible + (Etype (Discrim), + Etype (Corresponding_Discriminant (Discrim))) + then + Error_Msg_N + ("subtype must be compatible with parent discriminant", + Discrim); + end if; + + Next_Discriminant (Discrim); + end loop; + + -- Check whether the constraints of the full view statically + -- match those imposed by the parent subtype [7.3(13)]. + + if Present (Stored_Constraint (Derived_Type)) then + declare + C1, C2 : Elmt_Id; + + begin + C1 := First_Elmt (Discs); + C2 := First_Elmt (Stored_Constraint (Derived_Type)); + while Present (C1) and then Present (C2) loop + if not + Fully_Conformant_Expressions (Node (C1), Node (C2)) + then + Error_Msg_N ( + "not conformant with previous declaration", + Node (C1)); + end if; + + Next_Elmt (C1); + Next_Elmt (C2); + end loop; + end; + end if; + end if; + + -- STEP 2b: No new discriminants, inherit discriminants if any + + else + if Private_Extension then + Set_Has_Unknown_Discriminants + (Derived_Type, + Has_Unknown_Discriminants (Parent_Type) + or else Unknown_Discriminants_Present (N)); + + -- The partial view of the parent may have unknown discriminants, + -- but if the full view has discriminants and the parent type is + -- in scope they must be inherited. + + elsif Has_Unknown_Discriminants (Parent_Type) + and then + (not Has_Discriminants (Parent_Type) + or else not In_Open_Scopes (Scope (Parent_Type))) + then + Set_Has_Unknown_Discriminants (Derived_Type); + end if; + + if not Has_Unknown_Discriminants (Derived_Type) + and then not Has_Unknown_Discriminants (Parent_Base) + and then Has_Discriminants (Parent_Type) + then + Inherit_Discrims := True; + Set_Has_Discriminants + (Derived_Type, True); + Set_Discriminant_Constraint + (Derived_Type, Discriminant_Constraint (Parent_Base)); + end if; + + -- The following test is true for private types (remember + -- transformation 5. is not applied to those) and in an error + -- situation. + + if Constraint_Present then + Discs := Build_Discriminant_Constraints (Parent_Type, Indic); + end if; + + -- For now mark a new derived type as constrained only if it has no + -- discriminants. At the end of Build_Derived_Record_Type we properly + -- set this flag in the case of private extensions. See comments in + -- point 9. just before body of Build_Derived_Record_Type. + + Set_Is_Constrained + (Derived_Type, + not (Inherit_Discrims + or else Has_Unknown_Discriminants (Derived_Type))); + end if; + + -- STEP 3: initialize fields of derived type + + Set_Is_Tagged_Type (Derived_Type, Is_Tagged); + Set_Stored_Constraint (Derived_Type, No_Elist); + + -- Ada 2005 (AI-251): Private type-declarations can implement interfaces + -- but cannot be interfaces + + if not Private_Extension + and then Ekind (Derived_Type) /= E_Private_Type + and then Ekind (Derived_Type) /= E_Limited_Private_Type + then + Set_Is_Interface (Derived_Type, Interface_Present (Type_Def)); + Set_Abstract_Interfaces (Derived_Type, No_Elist); + end if; + + -- Fields inherited from the Parent_Type + + Set_Discard_Names + (Derived_Type, Einfo.Discard_Names (Parent_Type)); + Set_Has_Specified_Layout + (Derived_Type, Has_Specified_Layout (Parent_Type)); + Set_Is_Limited_Composite + (Derived_Type, Is_Limited_Composite (Parent_Type)); + Set_Is_Limited_Record + (Derived_Type, + Is_Limited_Record (Parent_Type) + and then not Is_Interface (Parent_Type)); + Set_Is_Private_Composite + (Derived_Type, Is_Private_Composite (Parent_Type)); + + -- Fields inherited from the Parent_Base + + Set_Has_Controlled_Component + (Derived_Type, Has_Controlled_Component (Parent_Base)); + Set_Has_Non_Standard_Rep + (Derived_Type, Has_Non_Standard_Rep (Parent_Base)); + Set_Has_Primitive_Operations + (Derived_Type, Has_Primitive_Operations (Parent_Base)); + + -- Direct controlled types do not inherit Finalize_Storage_Only flag + + if not Is_Controlled (Parent_Type) then + Set_Finalize_Storage_Only + (Derived_Type, Finalize_Storage_Only (Parent_Type)); + end if; + + -- Set fields for private derived types + + if Is_Private_Type (Derived_Type) then + Set_Depends_On_Private (Derived_Type, True); + Set_Private_Dependents (Derived_Type, New_Elmt_List); + + -- Inherit fields from non private record types. If this is the + -- completion of a derivation from a private type, the parent itself + -- is private, and the attributes come from its full view, which must + -- be present. + + else + if Is_Private_Type (Parent_Base) + and then not Is_Record_Type (Parent_Base) + then + Set_Component_Alignment + (Derived_Type, Component_Alignment (Full_View (Parent_Base))); + Set_C_Pass_By_Copy + (Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base))); + else + Set_Component_Alignment + (Derived_Type, Component_Alignment (Parent_Base)); + + Set_C_Pass_By_Copy + (Derived_Type, C_Pass_By_Copy (Parent_Base)); + end if; + end if; + + -- Set fields for tagged types + + if Is_Tagged then + Set_Primitive_Operations (Derived_Type, New_Elmt_List); + + -- All tagged types defined in Ada.Finalization are controlled + + if Chars (Scope (Derived_Type)) = Name_Finalization + and then Chars (Scope (Scope (Derived_Type))) = Name_Ada + and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard + then + Set_Is_Controlled (Derived_Type); + else + Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base)); + end if; + + Make_Class_Wide_Type (Derived_Type); + Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def)); + + if Has_Discriminants (Derived_Type) + and then Constraint_Present + then + Set_Stored_Constraint + (Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs)); + end if; + + -- Ada 2005 (AI-251): Look for the partial view of tagged types + -- declared in the private part. This will be used 1) to check that + -- the set of interfaces in both views is equal, and 2) to complete + -- the derivation of subprograms covering interfaces. + + Tagged_Partial_View := Empty; + + if Has_Private_Declaration (Derived_Type) then + Tagged_Partial_View := Next_Entity (Derived_Type); + loop + exit when Has_Private_Declaration (Tagged_Partial_View) + and then Full_View (Tagged_Partial_View) = Derived_Type; + + Next_Entity (Tagged_Partial_View); + end loop; + end if; + + -- Ada 2005 (AI-251): Collect the whole list of implemented + -- interfaces. + + if Ada_Version >= Ada_05 then + Set_Abstract_Interfaces (Derived_Type, New_Elmt_List); + + if Nkind (N) = N_Private_Extension_Declaration then + Collect_Interfaces (N, Derived_Type); + else + Collect_Interfaces (Type_Definition (N), Derived_Type); + end if; + end if; + + else + Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base)); + Set_Has_Non_Standard_Rep + (Derived_Type, Has_Non_Standard_Rep (Parent_Base)); + end if; + + -- STEP 4: Inherit components from the parent base and constrain them. + -- Apply the second transformation described in point 6. above. + + if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims) + or else not Has_Discriminants (Parent_Type) + or else not Is_Constrained (Parent_Type) + then + Constrs := Discs; + else + Constrs := Discriminant_Constraint (Parent_Type); + end if; + + Assoc_List := + Inherit_Components + (N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs); + + -- STEP 5a: Copy the parent record declaration for untagged types + + if not Is_Tagged then + + -- Discriminant_Constraint (Derived_Type) has been properly + -- constructed. Save it and temporarily set it to Empty because we + -- do not want the call to New_Copy_Tree below to mess this list. + + if Has_Discriminants (Derived_Type) then + Save_Discr_Constr := Discriminant_Constraint (Derived_Type); + Set_Discriminant_Constraint (Derived_Type, No_Elist); + else + Save_Discr_Constr := No_Elist; + end if; + + -- Save the Etype field of Derived_Type. It is correctly set now, + -- but the call to New_Copy tree may remap it to point to itself, + -- which is not what we want. Ditto for the Next_Entity field. + + Save_Etype := Etype (Derived_Type); + Save_Next_Entity := Next_Entity (Derived_Type); + + -- Assoc_List maps all stored discriminants in the Parent_Base to + -- stored discriminants in the Derived_Type. It is fundamental that + -- no types or itypes with discriminants other than the stored + -- discriminants appear in the entities declared inside + -- Derived_Type, since the back end cannot deal with it. + + New_Decl := + New_Copy_Tree + (Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc); + + -- Restore the fields saved prior to the New_Copy_Tree call + -- and compute the stored constraint. + + Set_Etype (Derived_Type, Save_Etype); + Set_Next_Entity (Derived_Type, Save_Next_Entity); + + if Has_Discriminants (Derived_Type) then + Set_Discriminant_Constraint + (Derived_Type, Save_Discr_Constr); + Set_Stored_Constraint + (Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs)); + Replace_Components (Derived_Type, New_Decl); + end if; + + -- Insert the new derived type declaration + + Rewrite (N, New_Decl); + + -- STEP 5b: Complete the processing for record extensions in generics + + -- There is no completion for record extensions declared in the + -- parameter part of a generic, so we need to complete processing for + -- these generic record extensions here. The Record_Type_Definition call + -- will change the Ekind of the components from E_Void to E_Component. + + elsif Private_Extension and then Is_Generic_Type (Derived_Type) then + Record_Type_Definition (Empty, Derived_Type); + + -- STEP 5c: Process the record extension for non private tagged types + + elsif not Private_Extension then + + -- Add the _parent field in the derived type + + Expand_Record_Extension (Derived_Type, Type_Def); + + -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the + -- implemented interfaces if we are in expansion mode + + if Expander_Active then + Add_Interface_Tag_Components (N, Derived_Type); + end if; + + -- Analyze the record extension + + Record_Type_Definition + (Record_Extension_Part (Type_Def), Derived_Type); + end if; + + End_Scope; + + if Etype (Derived_Type) = Any_Type then + return; + end if; + + -- Set delayed freeze and then derive subprograms, we need to do + -- this in this order so that derived subprograms inherit the + -- derived freeze if necessary. + + Set_Has_Delayed_Freeze (Derived_Type); + + if Derive_Subps then + + -- Ada 2005 (AI-251): Check if this tagged type implements abstract + -- interfaces + + Has_Interfaces := False; + + if Is_Tagged_Type (Derived_Type) then + declare + E : Entity_Id; + + begin + -- Handle private types + + if Present (Full_View (Derived_Type)) then + E := Full_View (Derived_Type); + else + E := Derived_Type; + end if; + + loop + if Is_Interface (E) + or else (Present (Abstract_Interfaces (E)) + and then + not Is_Empty_Elmt_List (Abstract_Interfaces (E))) + then + Has_Interfaces := True; + exit; + end if; + + exit when Etype (E) = E + + -- Handle private types + + or else (Present (Full_View (Etype (E))) + and then Full_View (Etype (E)) = E) + + -- Protect the frontend against wrong source + + or else Etype (E) = Derived_Type; + + -- Climb to the ancestor type handling private types + + if Present (Full_View (Etype (E))) then + E := Full_View (Etype (E)); + else + E := Etype (E); + end if; + end loop; + end; + end if; + + Derive_Subprograms (Parent_Type, Derived_Type); + + -- Ada 2005 (AI-251): Handle tagged types implementing interfaces + + if Is_Tagged_Type (Derived_Type) + and then Has_Interfaces + then + -- Ada 2005 (AI-251): If we are analyzing a full view that has + -- no partial view we derive the abstract interface Subprograms + + if No (Tagged_Partial_View) then + Derive_Interface_Subprograms (Derived_Type); + + -- Ada 2005 (AI-251): if we are analyzing a full view that has + -- a partial view we complete the derivation of the subprograms + + else + Complete_Subprograms_Derivation + (Partial_View => Tagged_Partial_View, + Derived_Type => Derived_Type); + end if; + + -- Ada 2005 (AI-251): In both cases we check if some of the + -- inherited subprograms cover interface primitives. + + declare + Iface_Subp : Entity_Id; + Iface_Subp_Elmt : Elmt_Id; + Prev_Alias : Entity_Id; + Subp : Entity_Id; + Subp_Elmt : Elmt_Id; + + begin + Iface_Subp_Elmt := + First_Elmt (Primitive_Operations (Derived_Type)); + while Present (Iface_Subp_Elmt) loop + Iface_Subp := Node (Iface_Subp_Elmt); + + -- Look for an abstract interface subprogram + + if Is_Abstract (Iface_Subp) + and then Present (Alias (Iface_Subp)) + and then Present (DTC_Entity (Alias (Iface_Subp))) + and then Is_Interface + (Scope (DTC_Entity (Alias (Iface_Subp)))) + then + -- Look for candidate primitive subprograms of the tagged + -- type that can cover this interface subprogram. + + Subp_Elmt := + First_Elmt (Primitive_Operations (Derived_Type)); + while Present (Subp_Elmt) loop + Subp := Node (Subp_Elmt); + + if not Is_Abstract (Subp) + and then Chars (Subp) = Chars (Iface_Subp) + and then Type_Conformant (Iface_Subp, Subp) + then + Prev_Alias := Alias (Iface_Subp); + + Check_Dispatching_Operation + (Subp => Subp, + Old_Subp => Iface_Subp); + + pragma Assert + (Alias (Iface_Subp) = Subp); + pragma Assert + (Abstract_Interface_Alias (Iface_Subp) + = Prev_Alias); + + -- Traverse the list of aliased subprograms to link + -- subp with its ultimate aliased subprogram. This + -- avoids problems with the backend. + + declare + E : Entity_Id; + + begin + E := Alias (Subp); + while Present (Alias (E)) loop + E := Alias (E); + end loop; + + Set_Alias (Subp, E); + end; + + Set_Has_Delayed_Freeze (Subp); + exit; + end if; + + Next_Elmt (Subp_Elmt); + end loop; + end if; + + Next_Elmt (Iface_Subp_Elmt); + end loop; + end; + end if; + end if; + + -- If we have a private extension which defines a constrained derived + -- type mark as constrained here after we have derived subprograms. See + -- comment on point 9. just above the body of Build_Derived_Record_Type. + + if Private_Extension and then Inherit_Discrims then + if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then + Set_Is_Constrained (Derived_Type, True); + Set_Discriminant_Constraint (Derived_Type, Discs); + + elsif Is_Constrained (Parent_Type) then + Set_Is_Constrained + (Derived_Type, True); + Set_Discriminant_Constraint + (Derived_Type, Discriminant_Constraint (Parent_Type)); + end if; + end if; + + -- Update the class_wide type, which shares the now-completed + -- entity list with its specific type. + + if Is_Tagged then + Set_First_Entity + (Class_Wide_Type (Derived_Type), First_Entity (Derived_Type)); + Set_Last_Entity + (Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type)); + end if; + + end Build_Derived_Record_Type; + + ------------------------ + -- Build_Derived_Type -- + ------------------------ + + procedure Build_Derived_Type + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Is_Completion : Boolean; + Derive_Subps : Boolean := True) + is + Parent_Base : constant Entity_Id := Base_Type (Parent_Type); + + begin + -- Set common attributes + + Set_Scope (Derived_Type, Current_Scope); + + Set_Ekind (Derived_Type, Ekind (Parent_Base)); + Set_Etype (Derived_Type, Parent_Base); + Set_Has_Task (Derived_Type, Has_Task (Parent_Base)); + + Set_Size_Info (Derived_Type, Parent_Type); + Set_RM_Size (Derived_Type, RM_Size (Parent_Type)); + Set_Convention (Derived_Type, Convention (Parent_Type)); + Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type)); + + -- The derived type inherits the representation clauses of the parent. + -- However, for a private type that is completed by a derivation, there + -- may be operation attributes that have been specified already (stream + -- attributes and External_Tag) and those must be provided. Finally, + -- if the partial view is a private extension, the representation items + -- of the parent have been inherited already, and should not be chained + -- twice to the derived type. + + if Is_Tagged_Type (Parent_Type) + and then Present (First_Rep_Item (Derived_Type)) + then + -- The existing items are either operational items or items inherited + -- from a private extension declaration. + + declare + Rep : Node_Id; + Found : Boolean := False; + + begin + Rep := First_Rep_Item (Derived_Type); + while Present (Rep) loop + if Rep = First_Rep_Item (Parent_Type) then + Found := True; + exit; + else + Rep := Next_Rep_Item (Rep); + end if; + end loop; + + if not Found then + Set_Next_Rep_Item + (First_Rep_Item (Derived_Type), First_Rep_Item (Parent_Type)); + end if; + end; + + else + Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type)); + end if; + + case Ekind (Parent_Type) is + when Numeric_Kind => + Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type); + + when Array_Kind => + Build_Derived_Array_Type (N, Parent_Type, Derived_Type); + + when E_Record_Type + | E_Record_Subtype + | Class_Wide_Kind => + Build_Derived_Record_Type + (N, Parent_Type, Derived_Type, Derive_Subps); + return; + + when Enumeration_Kind => + Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type); + + when Access_Kind => + Build_Derived_Access_Type (N, Parent_Type, Derived_Type); + + when Incomplete_Or_Private_Kind => + Build_Derived_Private_Type + (N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps); + + -- For discriminated types, the derivation includes deriving + -- primitive operations. For others it is done below. + + if Is_Tagged_Type (Parent_Type) + or else Has_Discriminants (Parent_Type) + or else (Present (Full_View (Parent_Type)) + and then Has_Discriminants (Full_View (Parent_Type))) + then + return; + end if; + + when Concurrent_Kind => + Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type); + + when others => + raise Program_Error; + end case; + + if Etype (Derived_Type) = Any_Type then + return; + end if; + + -- Set delayed freeze and then derive subprograms, we need to do this + -- in this order so that derived subprograms inherit the derived freeze + -- if necessary. + + Set_Has_Delayed_Freeze (Derived_Type); + if Derive_Subps then + Derive_Subprograms (Parent_Type, Derived_Type); + end if; + + Set_Has_Primitive_Operations + (Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type)); + end Build_Derived_Type; + + ----------------------- + -- Build_Discriminal -- + ----------------------- + + procedure Build_Discriminal (Discrim : Entity_Id) is + D_Minal : Entity_Id; + CR_Disc : Entity_Id; + + begin + -- A discriminal has the same name as the discriminant + + D_Minal := + Make_Defining_Identifier (Sloc (Discrim), + Chars => Chars (Discrim)); + + Set_Ekind (D_Minal, E_In_Parameter); + Set_Mechanism (D_Minal, Default_Mechanism); + Set_Etype (D_Minal, Etype (Discrim)); + + Set_Discriminal (Discrim, D_Minal); + Set_Discriminal_Link (D_Minal, Discrim); + + -- For task types, build at once the discriminants of the corresponding + -- record, which are needed if discriminants are used in entry defaults + -- and in family bounds. + + if Is_Concurrent_Type (Current_Scope) + or else Is_Limited_Type (Current_Scope) + then + CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim)); + + Set_Ekind (CR_Disc, E_In_Parameter); + Set_Mechanism (CR_Disc, Default_Mechanism); + Set_Etype (CR_Disc, Etype (Discrim)); + Set_Discriminal_Link (CR_Disc, Discrim); + Set_CR_Discriminant (Discrim, CR_Disc); + end if; + end Build_Discriminal; + + ------------------------------------ + -- Build_Discriminant_Constraints -- + ------------------------------------ + + function Build_Discriminant_Constraints + (T : Entity_Id; + Def : Node_Id; + Derived_Def : Boolean := False) return Elist_Id + is + C : constant Node_Id := Constraint (Def); + Nb_Discr : constant Nat := Number_Discriminants (T); + + Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty); + -- Saves the expression corresponding to a given discriminant in T + + function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat; + -- Return the Position number within array Discr_Expr of a discriminant + -- D within the discriminant list of the discriminated type T. + + ------------------ + -- Pos_Of_Discr -- + ------------------ + + function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is + Disc : Entity_Id; + + begin + Disc := First_Discriminant (T); + for J in Discr_Expr'Range loop + if Disc = D then + return J; + end if; + + Next_Discriminant (Disc); + end loop; + + -- Note: Since this function is called on discriminants that are + -- known to belong to the discriminated type, falling through the + -- loop with no match signals an internal compiler error. + + raise Program_Error; + end Pos_Of_Discr; + + -- Declarations local to Build_Discriminant_Constraints + + Discr : Entity_Id; + E : Entity_Id; + Elist : constant Elist_Id := New_Elmt_List; + + Constr : Node_Id; + Expr : Node_Id; + Id : Node_Id; + Position : Nat; + Found : Boolean; + + Discrim_Present : Boolean := False; + + -- Start of processing for Build_Discriminant_Constraints + + begin + -- The following loop will process positional associations only. + -- For a positional association, the (single) discriminant is + -- implicitly specified by position, in textual order (RM 3.7.2). + + Discr := First_Discriminant (T); + Constr := First (Constraints (C)); + + for D in Discr_Expr'Range loop + exit when Nkind (Constr) = N_Discriminant_Association; + + if No (Constr) then + Error_Msg_N ("too few discriminants given in constraint", C); + return New_Elmt_List; + + elsif Nkind (Constr) = N_Range + or else (Nkind (Constr) = N_Attribute_Reference + and then + Attribute_Name (Constr) = Name_Range) + then + Error_Msg_N + ("a range is not a valid discriminant constraint", Constr); + Discr_Expr (D) := Error; + + else + Analyze_And_Resolve (Constr, Base_Type (Etype (Discr))); + Discr_Expr (D) := Constr; + end if; + + Next_Discriminant (Discr); + Next (Constr); + end loop; + + if No (Discr) and then Present (Constr) then + Error_Msg_N ("too many discriminants given in constraint", Constr); + return New_Elmt_List; + end if; + + -- Named associations can be given in any order, but if both positional + -- and named associations are used in the same discriminant constraint, + -- then positional associations must occur first, at their normal + -- position. Hence once a named association is used, the rest of the + -- discriminant constraint must use only named associations. + + while Present (Constr) loop + + -- Positional association forbidden after a named association + + if Nkind (Constr) /= N_Discriminant_Association then + Error_Msg_N ("positional association follows named one", Constr); + return New_Elmt_List; + + -- Otherwise it is a named association + + else + -- E records the type of the discriminants in the named + -- association. All the discriminants specified in the same name + -- association must have the same type. + + E := Empty; + + -- Search the list of discriminants in T to see if the simple name + -- given in the constraint matches any of them. + + Id := First (Selector_Names (Constr)); + while Present (Id) loop + Found := False; + + -- If Original_Discriminant is present, we are processing a + -- generic instantiation and this is an instance node. We need + -- to find the name of the corresponding discriminant in the + -- actual record type T and not the name of the discriminant in + -- the generic formal. Example: + -- + -- generic + -- type G (D : int) is private; + -- package P is + -- subtype W is G (D => 1); + -- end package; + -- type Rec (X : int) is record ... end record; + -- package Q is new P (G => Rec); + -- + -- At the point of the instantiation, formal type G is Rec + -- and therefore when reanalyzing "subtype W is G (D => 1);" + -- which really looks like "subtype W is Rec (D => 1);" at + -- the point of instantiation, we want to find the discriminant + -- that corresponds to D in Rec, ie X. + + if Present (Original_Discriminant (Id)) then + Discr := Find_Corresponding_Discriminant (Id, T); + Found := True; + + else + Discr := First_Discriminant (T); + while Present (Discr) loop + if Chars (Discr) = Chars (Id) then + Found := True; + exit; + end if; + + Next_Discriminant (Discr); + end loop; + + if not Found then + Error_Msg_N ("& does not match any discriminant", Id); + return New_Elmt_List; + + -- The following is only useful for the benefit of generic + -- instances but it does not interfere with other + -- processing for the non-generic case so we do it in all + -- cases (for generics this statement is executed when + -- processing the generic definition, see comment at the + -- beginning of this if statement). + + else + Set_Original_Discriminant (Id, Discr); + end if; + end if; + + Position := Pos_Of_Discr (T, Discr); + + if Present (Discr_Expr (Position)) then + Error_Msg_N ("duplicate constraint for discriminant&", Id); + + else + -- Each discriminant specified in the same named association + -- must be associated with a separate copy of the + -- corresponding expression. + + if Present (Next (Id)) then + Expr := New_Copy_Tree (Expression (Constr)); + Set_Parent (Expr, Parent (Expression (Constr))); + else + Expr := Expression (Constr); + end if; + + Discr_Expr (Position) := Expr; + Analyze_And_Resolve (Expr, Base_Type (Etype (Discr))); + end if; + + -- A discriminant association with more than one discriminant + -- name is only allowed if the named discriminants are all of + -- the same type (RM 3.7.1(8)). + + if E = Empty then + E := Base_Type (Etype (Discr)); + + elsif Base_Type (Etype (Discr)) /= E then + Error_Msg_N + ("all discriminants in an association " & + "must have the same type", Id); + end if; + + Next (Id); + end loop; + end if; + + Next (Constr); + end loop; + + -- A discriminant constraint must provide exactly one value for each + -- discriminant of the type (RM 3.7.1(8)). + + for J in Discr_Expr'Range loop + if No (Discr_Expr (J)) then + Error_Msg_N ("too few discriminants given in constraint", C); + return New_Elmt_List; + end if; + end loop; + + -- Determine if there are discriminant expressions in the constraint + + for J in Discr_Expr'Range loop + if Denotes_Discriminant (Discr_Expr (J), Check_Protected => True) then + Discrim_Present := True; + end if; + end loop; + + -- Build an element list consisting of the expressions given in the + -- discriminant constraint and apply the appropriate checks. The list + -- is constructed after resolving any named discriminant associations + -- and therefore the expressions appear in the textual order of the + -- discriminants. + + Discr := First_Discriminant (T); + for J in Discr_Expr'Range loop + if Discr_Expr (J) /= Error then + + Append_Elmt (Discr_Expr (J), Elist); + + -- If any of the discriminant constraints is given by a + -- discriminant and we are in a derived type declaration we + -- have a discriminant renaming. Establish link between new + -- and old discriminant. + + if Denotes_Discriminant (Discr_Expr (J)) then + if Derived_Def then + Set_Corresponding_Discriminant + (Entity (Discr_Expr (J)), Discr); + end if; + + -- Force the evaluation of non-discriminant expressions. + -- If we have found a discriminant in the constraint 3.4(26) + -- and 3.8(18) demand that no range checks are performed are + -- after evaluation. If the constraint is for a component + -- definition that has a per-object constraint, expressions are + -- evaluated but not checked either. In all other cases perform + -- a range check. + + else + if Discrim_Present then + null; + + elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration + and then + Has_Per_Object_Constraint + (Defining_Identifier (Parent (Parent (Def)))) + then + null; + + elsif Is_Access_Type (Etype (Discr)) then + Apply_Constraint_Check (Discr_Expr (J), Etype (Discr)); + + else + Apply_Range_Check (Discr_Expr (J), Etype (Discr)); + end if; + + Force_Evaluation (Discr_Expr (J)); + end if; + + -- Check that the designated type of an access discriminant's + -- expression is not a class-wide type unless the discriminant's + -- designated type is also class-wide. + + if Ekind (Etype (Discr)) = E_Anonymous_Access_Type + and then not Is_Class_Wide_Type + (Designated_Type (Etype (Discr))) + and then Etype (Discr_Expr (J)) /= Any_Type + and then Is_Class_Wide_Type + (Designated_Type (Etype (Discr_Expr (J)))) + then + Wrong_Type (Discr_Expr (J), Etype (Discr)); + end if; + end if; + + Next_Discriminant (Discr); + end loop; + + return Elist; + end Build_Discriminant_Constraints; + + --------------------------------- + -- Build_Discriminated_Subtype -- + --------------------------------- + + procedure Build_Discriminated_Subtype + (T : Entity_Id; + Def_Id : Entity_Id; + Elist : Elist_Id; + Related_Nod : Node_Id; + For_Access : Boolean := False) + is + Has_Discrs : constant Boolean := Has_Discriminants (T); + Constrained : constant Boolean + := (Has_Discrs + and then not Is_Empty_Elmt_List (Elist) + and then not Is_Class_Wide_Type (T)) + or else Is_Constrained (T); + + begin + if Ekind (T) = E_Record_Type then + if For_Access then + Set_Ekind (Def_Id, E_Private_Subtype); + Set_Is_For_Access_Subtype (Def_Id, True); + else + Set_Ekind (Def_Id, E_Record_Subtype); + end if; + + elsif Ekind (T) = E_Task_Type then + Set_Ekind (Def_Id, E_Task_Subtype); + + elsif Ekind (T) = E_Protected_Type then + Set_Ekind (Def_Id, E_Protected_Subtype); + + elsif Is_Private_Type (T) then + Set_Ekind (Def_Id, Subtype_Kind (Ekind (T))); + + elsif Is_Class_Wide_Type (T) then + Set_Ekind (Def_Id, E_Class_Wide_Subtype); + + else + -- Incomplete type. attach subtype to list of dependents, to be + -- completed with full view of parent type, unless is it the + -- designated subtype of a record component within an init_proc. + -- This last case arises for a component of an access type whose + -- designated type is incomplete (e.g. a Taft Amendment type). + -- The designated subtype is within an inner scope, and needs no + -- elaboration, because only the access type is needed in the + -- initialization procedure. + + Set_Ekind (Def_Id, Ekind (T)); + + if For_Access and then Within_Init_Proc then + null; + else + Append_Elmt (Def_Id, Private_Dependents (T)); + end if; + end if; + + Set_Etype (Def_Id, T); + Init_Size_Align (Def_Id); + Set_Has_Discriminants (Def_Id, Has_Discrs); + Set_Is_Constrained (Def_Id, Constrained); + + Set_First_Entity (Def_Id, First_Entity (T)); + Set_Last_Entity (Def_Id, Last_Entity (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + + if Is_Tagged_Type (T) then + Set_Is_Tagged_Type (Def_Id); + Make_Class_Wide_Type (Def_Id); + end if; + + Set_Stored_Constraint (Def_Id, No_Elist); + + if Has_Discrs then + Set_Discriminant_Constraint (Def_Id, Elist); + Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id); + end if; + + if Is_Tagged_Type (T) then + + -- Ada 2005 (AI-251): In case of concurrent types we inherit the + -- concurrent record type (which has the list of primitive + -- operations). + + if Ada_Version >= Ada_05 + and then Is_Concurrent_Type (T) + then + Set_Corresponding_Record_Type (Def_Id, + Corresponding_Record_Type (T)); + else + Set_Primitive_Operations (Def_Id, Primitive_Operations (T)); + end if; + + Set_Is_Abstract (Def_Id, Is_Abstract (T)); + end if; + + -- Subtypes introduced by component declarations do not need to be + -- marked as delayed, and do not get freeze nodes, because the semantics + -- verifies that the parents of the subtypes are frozen before the + -- enclosing record is frozen. + + if not Is_Type (Scope (Def_Id)) then + Set_Depends_On_Private (Def_Id, Depends_On_Private (T)); + + if Is_Private_Type (T) + and then Present (Full_View (T)) + then + Conditional_Delay (Def_Id, Full_View (T)); + else + Conditional_Delay (Def_Id, T); + end if; + end if; + + if Is_Record_Type (T) then + Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T)); + + if Has_Discrs + and then not Is_Empty_Elmt_List (Elist) + and then not For_Access + then + Create_Constrained_Components (Def_Id, Related_Nod, T, Elist); + elsif not For_Access then + Set_Cloned_Subtype (Def_Id, T); + end if; + end if; + + end Build_Discriminated_Subtype; + + ------------------------ + -- Build_Scalar_Bound -- + ------------------------ + + function Build_Scalar_Bound + (Bound : Node_Id; + Par_T : Entity_Id; + Der_T : Entity_Id) return Node_Id + is + New_Bound : Entity_Id; + + begin + -- Note: not clear why this is needed, how can the original bound + -- be unanalyzed at this point? and if it is, what business do we + -- have messing around with it? and why is the base type of the + -- parent type the right type for the resolution. It probably is + -- not! It is OK for the new bound we are creating, but not for + -- the old one??? Still if it never happens, no problem! + + Analyze_And_Resolve (Bound, Base_Type (Par_T)); + + if Nkind (Bound) = N_Integer_Literal + or else Nkind (Bound) = N_Real_Literal + then + New_Bound := New_Copy (Bound); + Set_Etype (New_Bound, Der_T); + Set_Analyzed (New_Bound); + + elsif Is_Entity_Name (Bound) then + New_Bound := OK_Convert_To (Der_T, New_Copy (Bound)); + + -- The following is almost certainly wrong. What business do we have + -- relocating a node (Bound) that is presumably still attached to + -- the tree elsewhere??? + + else + New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound)); + end if; + + Set_Etype (New_Bound, Der_T); + return New_Bound; + end Build_Scalar_Bound; + + -------------------------------- + -- Build_Underlying_Full_View -- + -------------------------------- + + procedure Build_Underlying_Full_View + (N : Node_Id; + Typ : Entity_Id; + Par : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Subt : constant Entity_Id := + Make_Defining_Identifier + (Loc, New_External_Name (Chars (Typ), 'S')); + + Constr : Node_Id; + Indic : Node_Id; + C : Node_Id; + Id : Node_Id; + + procedure Set_Discriminant_Name (Id : Node_Id); + -- If the derived type has discriminants, they may rename discriminants + -- of the parent. When building the full view of the parent, we need to + -- recover the names of the original discriminants if the constraint is + -- given by named associations. + + --------------------------- + -- Set_Discriminant_Name -- + --------------------------- + + procedure Set_Discriminant_Name (Id : Node_Id) is + Disc : Entity_Id; + + begin + Set_Original_Discriminant (Id, Empty); + + if Has_Discriminants (Typ) then + Disc := First_Discriminant (Typ); + while Present (Disc) loop + if Chars (Disc) = Chars (Id) + and then Present (Corresponding_Discriminant (Disc)) + then + Set_Chars (Id, Chars (Corresponding_Discriminant (Disc))); + end if; + Next_Discriminant (Disc); + end loop; + end if; + end Set_Discriminant_Name; + + -- Start of processing for Build_Underlying_Full_View + + begin + if Nkind (N) = N_Full_Type_Declaration then + Constr := Constraint (Subtype_Indication (Type_Definition (N))); + + elsif Nkind (N) = N_Subtype_Declaration then + Constr := New_Copy_Tree (Constraint (Subtype_Indication (N))); + + elsif Nkind (N) = N_Component_Declaration then + Constr := + New_Copy_Tree + (Constraint (Subtype_Indication (Component_Definition (N)))); + + else + raise Program_Error; + end if; + + C := First (Constraints (Constr)); + while Present (C) loop + if Nkind (C) = N_Discriminant_Association then + Id := First (Selector_Names (C)); + while Present (Id) loop + Set_Discriminant_Name (Id); + Next (Id); + end loop; + end if; + + Next (C); + end loop; + + Indic := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Subt, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Reference_To (Par, Loc), + Constraint => New_Copy_Tree (Constr))); + + -- If this is a component subtype for an outer itype, it is not + -- a list member, so simply set the parent link for analysis: if + -- the enclosing type does not need to be in a declarative list, + -- neither do the components. + + if Is_List_Member (N) + and then Nkind (N) /= N_Component_Declaration + then + Insert_Before (N, Indic); + else + Set_Parent (Indic, Parent (N)); + end if; + + Analyze (Indic); + Set_Underlying_Full_View (Typ, Full_View (Subt)); + end Build_Underlying_Full_View; + + ------------------------------- + -- Check_Abstract_Overriding -- + ------------------------------- + + procedure Check_Abstract_Overriding (T : Entity_Id) is + Op_List : Elist_Id; + Elmt : Elmt_Id; + Subp : Entity_Id; + Alias_Subp : Entity_Id; + Type_Def : Node_Id; + + begin + Op_List := Primitive_Operations (T); + + -- Loop to check primitive operations + + Elmt := First_Elmt (Op_List); + while Present (Elmt) loop + Subp := Node (Elmt); + Alias_Subp := Alias (Subp); + + -- Inherited subprograms are identified by the fact that they do not + -- come from source, and the associated source location is the + -- location of the first subtype of the derived type. + + -- Special exception, do not complain about failure to override the + -- stream routines _Input and _Output, as well as the primitive + -- operations used in dispatching selects since we always provide + -- automatic overridings for these subprograms. + + if (Is_Abstract (Subp) + or else (Has_Controlling_Result (Subp) + and then Present (Alias_Subp) + and then not Comes_From_Source (Subp) + and then Sloc (Subp) = Sloc (First_Subtype (T)))) + and then not Is_TSS (Subp, TSS_Stream_Input) + and then not Is_TSS (Subp, TSS_Stream_Output) + and then not Is_Abstract (T) + and then Chars (Subp) /= Name_uDisp_Asynchronous_Select + and then Chars (Subp) /= Name_uDisp_Conditional_Select + and then Chars (Subp) /= Name_uDisp_Get_Prim_Op_Kind + and then Chars (Subp) /= Name_uDisp_Timed_Select + then + if Present (Alias_Subp) then + + -- Only perform the check for a derived subprogram when the + -- type has an explicit record extension. This avoids + -- incorrectly flagging abstract subprograms for the case of a + -- type without an extension derived from a formal type with a + -- tagged actual (can occur within a private part). + + -- Ada 2005 (AI-391): In the case of an inherited function with + -- a controlling result of the type, the rule does not apply if + -- the type is a null extension (unless the parent function + -- itself is abstract, in which case the function must still be + -- be overridden). The expander will generate an overriding + -- wrapper function calling the parent subprogram (see + -- Exp_Ch3.Make_Controlling_Wrapper_Functions). + + Type_Def := Type_Definition (Parent (T)); + if Nkind (Type_Def) = N_Derived_Type_Definition + and then Present (Record_Extension_Part (Type_Def)) + and then + (Ada_Version < Ada_05 + or else not Is_Null_Extension (T) + or else Ekind (Subp) = E_Procedure + or else not Has_Controlling_Result (Subp) + or else Is_Abstract (Alias_Subp) + or else Is_Access_Type (Etype (Subp))) + then + Error_Msg_NE + ("type must be declared abstract or & overridden", + T, Subp); + + -- Traverse the whole chain of aliased subprograms to + -- complete the error notification. This is especially + -- useful for traceability of the chain of entities when the + -- subprogram corresponds with an interface subprogram + -- (which might be defined in another package) + + if Present (Alias_Subp) then + declare + E : Entity_Id; + + begin + E := Subp; + while Present (Alias (E)) loop + Error_Msg_Sloc := Sloc (E); + Error_Msg_NE ("\& has been inherited #", T, Subp); + E := Alias (E); + end loop; + + Error_Msg_Sloc := Sloc (E); + Error_Msg_NE + ("\& has been inherited from subprogram #", T, Subp); + end; + end if; + + -- Ada 2005 (AI-345): Protected or task type implementing + -- abstract interfaces. + + elsif Is_Concurrent_Record_Type (T) + and then Present (Abstract_Interfaces (T)) + then + Error_Msg_NE + ("interface subprogram & must be overridden", + T, Subp); + end if; + else + Error_Msg_NE + ("abstract subprogram not allowed for type&", + Subp, T); + Error_Msg_NE + ("nonabstract type has abstract subprogram&", + T, Subp); + end if; + end if; + + Next_Elmt (Elmt); + end loop; + end Check_Abstract_Overriding; + + ------------------------------------------------ + -- Check_Access_Discriminant_Requires_Limited -- + ------------------------------------------------ + + procedure Check_Access_Discriminant_Requires_Limited + (D : Node_Id; + Loc : Node_Id) + is + begin + -- A discriminant_specification for an access discriminant shall appear + -- only in the declaration for a task or protected type, or for a type + -- with the reserved word 'limited' in its definition or in one of its + -- ancestors. (RM 3.7(10)) + + if Nkind (Discriminant_Type (D)) = N_Access_Definition + and then not Is_Concurrent_Type (Current_Scope) + and then not Is_Concurrent_Record_Type (Current_Scope) + and then not Is_Limited_Record (Current_Scope) + and then Ekind (Current_Scope) /= E_Limited_Private_Type + then + Error_Msg_N + ("access discriminants allowed only for limited types", Loc); + end if; + end Check_Access_Discriminant_Requires_Limited; + + ----------------------------------- + -- Check_Aliased_Component_Types -- + ----------------------------------- + + procedure Check_Aliased_Component_Types (T : Entity_Id) is + C : Entity_Id; + + begin + -- ??? Also need to check components of record extensions, but not + -- components of protected types (which are always limited). + + -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such + -- types to be unconstrained. This is safe because it is illegal to + -- create access subtypes to such types with explicit discriminant + -- constraints. + + if not Is_Limited_Type (T) then + if Ekind (T) = E_Record_Type then + C := First_Component (T); + while Present (C) loop + if Is_Aliased (C) + and then Has_Discriminants (Etype (C)) + and then not Is_Constrained (Etype (C)) + and then not In_Instance_Body + and then Ada_Version < Ada_05 + then + Error_Msg_N + ("aliased component must be constrained ('R'M 3.6(11))", + C); + end if; + + Next_Component (C); + end loop; + + elsif Ekind (T) = E_Array_Type then + if Has_Aliased_Components (T) + and then Has_Discriminants (Component_Type (T)) + and then not Is_Constrained (Component_Type (T)) + and then not In_Instance_Body + and then Ada_Version < Ada_05 + then + Error_Msg_N + ("aliased component type must be constrained ('R'M 3.6(11))", + T); + end if; + end if; + end if; + end Check_Aliased_Component_Types; + + ---------------------- + -- Check_Completion -- + ---------------------- + + procedure Check_Completion (Body_Id : Node_Id := Empty) is + E : Entity_Id; + + procedure Post_Error; + -- Post error message for lack of completion for entity E + + ---------------- + -- Post_Error -- + ---------------- + + procedure Post_Error is + begin + if not Comes_From_Source (E) then + + if Ekind (E) = E_Task_Type + or else Ekind (E) = E_Protected_Type + then + -- It may be an anonymous protected type created for a + -- single variable. Post error on variable, if present. + + declare + Var : Entity_Id; + + begin + Var := First_Entity (Current_Scope); + while Present (Var) loop + exit when Etype (Var) = E + and then Comes_From_Source (Var); + + Next_Entity (Var); + end loop; + + if Present (Var) then + E := Var; + end if; + end; + end if; + end if; + + -- If a generated entity has no completion, then either previous + -- semantic errors have disabled the expansion phase, or else we had + -- missing subunits, or else we are compiling without expan- sion, + -- or else something is very wrong. + + if not Comes_From_Source (E) then + pragma Assert + (Serious_Errors_Detected > 0 + or else Configurable_Run_Time_Violations > 0 + or else Subunits_Missing + or else not Expander_Active); + return; + + -- Here for source entity + + else + -- Here if no body to post the error message, so we post the error + -- on the declaration that has no completion. This is not really + -- the right place to post it, think about this later ??? + + if No (Body_Id) then + if Is_Type (E) then + Error_Msg_NE + ("missing full declaration for }", Parent (E), E); + else + Error_Msg_NE + ("missing body for &", Parent (E), E); + end if; + + -- Package body has no completion for a declaration that appears + -- in the corresponding spec. Post error on the body, with a + -- reference to the non-completed declaration. + + else + Error_Msg_Sloc := Sloc (E); + + if Is_Type (E) then + Error_Msg_NE + ("missing full declaration for }!", Body_Id, E); + + elsif Is_Overloadable (E) + and then Current_Entity_In_Scope (E) /= E + then + -- It may be that the completion is mistyped and appears + -- as a distinct overloading of the entity. + + declare + Candidate : constant Entity_Id := + Current_Entity_In_Scope (E); + Decl : constant Node_Id := + Unit_Declaration_Node (Candidate); + + begin + if Is_Overloadable (Candidate) + and then Ekind (Candidate) = Ekind (E) + and then Nkind (Decl) = N_Subprogram_Body + and then Acts_As_Spec (Decl) + then + Check_Type_Conformant (Candidate, E); + + else + Error_Msg_NE ("missing body for & declared#!", + Body_Id, E); + end if; + end; + else + Error_Msg_NE ("missing body for & declared#!", + Body_Id, E); + end if; + end if; + end if; + end Post_Error; + + -- Start processing for Check_Completion + + begin + E := First_Entity (Current_Scope); + while Present (E) loop + if Is_Intrinsic_Subprogram (E) then + null; + + -- The following situation requires special handling: a child + -- unit that appears in the context clause of the body of its + -- parent: + + -- procedure Parent.Child (...); + + -- with Parent.Child; + -- package body Parent is + + -- Here Parent.Child appears as a local entity, but should not + -- be flagged as requiring completion, because it is a + -- compilation unit. + + elsif Ekind (E) = E_Function + or else Ekind (E) = E_Procedure + or else Ekind (E) = E_Generic_Function + or else Ekind (E) = E_Generic_Procedure + then + if not Has_Completion (E) + and then not Is_Abstract (E) + and then Nkind (Parent (Unit_Declaration_Node (E))) /= + N_Compilation_Unit + and then Chars (E) /= Name_uSize + then + Post_Error; + end if; + + elsif Is_Entry (E) then + if not Has_Completion (E) and then + (Ekind (Scope (E)) = E_Protected_Object + or else Ekind (Scope (E)) = E_Protected_Type) + then + Post_Error; + end if; + + elsif Is_Package_Or_Generic_Package (E) then + if Unit_Requires_Body (E) then + if not Has_Completion (E) + and then Nkind (Parent (Unit_Declaration_Node (E))) /= + N_Compilation_Unit + then + Post_Error; + end if; + + elsif not Is_Child_Unit (E) then + May_Need_Implicit_Body (E); + end if; + + elsif Ekind (E) = E_Incomplete_Type + and then No (Underlying_Type (E)) + then + Post_Error; + + elsif (Ekind (E) = E_Task_Type or else + Ekind (E) = E_Protected_Type) + and then not Has_Completion (E) + then + Post_Error; + + -- A single task declared in the current scope is a constant, verify + -- that the body of its anonymous type is in the same scope. If the + -- task is defined elsewhere, this may be a renaming declaration for + -- which no completion is needed. + + elsif Ekind (E) = E_Constant + and then Ekind (Etype (E)) = E_Task_Type + and then not Has_Completion (Etype (E)) + and then Scope (Etype (E)) = Current_Scope + then + Post_Error; + + elsif Ekind (E) = E_Protected_Object + and then not Has_Completion (Etype (E)) + then + Post_Error; + + elsif Ekind (E) = E_Record_Type then + if Is_Tagged_Type (E) then + Check_Abstract_Overriding (E); + end if; + + Check_Aliased_Component_Types (E); + + elsif Ekind (E) = E_Array_Type then + Check_Aliased_Component_Types (E); + + end if; + + Next_Entity (E); + end loop; + end Check_Completion; + + ---------------------------- + -- Check_Delta_Expression -- + ---------------------------- + + procedure Check_Delta_Expression (E : Node_Id) is + begin + if not (Is_Real_Type (Etype (E))) then + Wrong_Type (E, Any_Real); + + elsif not Is_OK_Static_Expression (E) then + Flag_Non_Static_Expr + ("non-static expression used for delta value!", E); + + elsif not UR_Is_Positive (Expr_Value_R (E)) then + Error_Msg_N ("delta expression must be positive", E); + + else + return; + end if; + + -- If any of above errors occurred, then replace the incorrect + -- expression by the real 0.1, which should prevent further errors. + + Rewrite (E, + Make_Real_Literal (Sloc (E), Ureal_Tenth)); + Analyze_And_Resolve (E, Standard_Float); + end Check_Delta_Expression; + + ----------------------------- + -- Check_Digits_Expression -- + ----------------------------- + + procedure Check_Digits_Expression (E : Node_Id) is + begin + if not (Is_Integer_Type (Etype (E))) then + Wrong_Type (E, Any_Integer); + + elsif not Is_OK_Static_Expression (E) then + Flag_Non_Static_Expr + ("non-static expression used for digits value!", E); + + elsif Expr_Value (E) <= 0 then + Error_Msg_N ("digits value must be greater than zero", E); + + else + return; + end if; + + -- If any of above errors occurred, then replace the incorrect + -- expression by the integer 1, which should prevent further errors. + + Rewrite (E, Make_Integer_Literal (Sloc (E), 1)); + Analyze_And_Resolve (E, Standard_Integer); + + end Check_Digits_Expression; + + -------------------------- + -- Check_Initialization -- + -------------------------- + + procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is + begin + if (Is_Limited_Type (T) + or else Is_Limited_Composite (T)) + and then not In_Instance + and then not In_Inlined_Body + then + -- Ada 2005 (AI-287): Relax the strictness of the front-end in + -- case of limited aggregates and extension aggregates. + + if Ada_Version >= Ada_05 + and then (Nkind (Exp) = N_Aggregate + or else Nkind (Exp) = N_Extension_Aggregate) + then + null; + else + Error_Msg_N + ("cannot initialize entities of limited type", Exp); + Explain_Limited_Type (T, Exp); + end if; + end if; + end Check_Initialization; + + ------------------------------------ + -- Check_Or_Process_Discriminants -- + ------------------------------------ + + -- If an incomplete or private type declaration was already given for the + -- type, the discriminants may have already been processed if they were + -- present on the incomplete declaration. In this case a full conformance + -- check is performed otherwise just process them. + + procedure Check_Or_Process_Discriminants + (N : Node_Id; + T : Entity_Id; + Prev : Entity_Id := Empty) + is + begin + if Has_Discriminants (T) then + + -- Make the discriminants visible to component declarations + + declare + D : Entity_Id; + Prev : Entity_Id; + + begin + D := First_Discriminant (T); + while Present (D) loop + Prev := Current_Entity (D); + Set_Current_Entity (D); + Set_Is_Immediately_Visible (D); + Set_Homonym (D, Prev); + + -- Ada 2005 (AI-230): Access discriminant allowed in + -- non-limited record types. + + if Ada_Version < Ada_05 then + + -- This restriction gets applied to the full type here. It + -- has already been applied earlier to the partial view. + + Check_Access_Discriminant_Requires_Limited (Parent (D), N); + end if; + + Next_Discriminant (D); + end loop; + end; + + elsif Present (Discriminant_Specifications (N)) then + Process_Discriminants (N, Prev); + end if; + end Check_Or_Process_Discriminants; + + ---------------------- + -- Check_Real_Bound -- + ---------------------- + + procedure Check_Real_Bound (Bound : Node_Id) is + begin + if not Is_Real_Type (Etype (Bound)) then + Error_Msg_N + ("bound in real type definition must be of real type", Bound); + + elsif not Is_OK_Static_Expression (Bound) then + Flag_Non_Static_Expr + ("non-static expression used for real type bound!", Bound); + + else + return; + end if; + + Rewrite + (Bound, Make_Real_Literal (Sloc (Bound), Ureal_0)); + Analyze (Bound); + Resolve (Bound, Standard_Float); + end Check_Real_Bound; + + ------------------------ + -- Collect_Interfaces -- + ------------------------ + + procedure Collect_Interfaces (N : Node_Id; Derived_Type : Entity_Id) is + Intf : Node_Id; + + procedure Add_Interface (Iface : Entity_Id); + -- Add one interface + + ------------------- + -- Add_Interface -- + ------------------- + + procedure Add_Interface (Iface : Entity_Id) is + Elmt : Elmt_Id; + + begin + Elmt := First_Elmt (Abstract_Interfaces (Derived_Type)); + while Present (Elmt) and then Node (Elmt) /= Iface loop + Next_Elmt (Elmt); + end loop; + + if No (Elmt) then + Append_Elmt (Node => Iface, + To => Abstract_Interfaces (Derived_Type)); + end if; + end Add_Interface; + + -- Start of processing for Collect_Interfaces + + begin + pragma Assert (False + or else Nkind (N) = N_Derived_Type_Definition + or else Nkind (N) = N_Record_Definition + or else Nkind (N) = N_Private_Extension_Declaration); + + -- Traverse the graph of ancestor interfaces + + if Is_Non_Empty_List (Interface_List (N)) then + Intf := First (Interface_List (N)); + while Present (Intf) loop + + -- Protect against wrong uses. For example: + -- type I is interface; + -- type O is tagged null record; + -- type Wrong is new I and O with null record; -- ERROR + + if Is_Interface (Etype (Intf)) then + + -- Do not add the interface when the derived type already + -- implements this interface + + if not Interface_Present_In_Ancestor (Derived_Type, + Etype (Intf)) + then + Collect_Interfaces + (Type_Definition (Parent (Etype (Intf))), + Derived_Type); + Add_Interface (Etype (Intf)); + end if; + end if; + + Next (Intf); + end loop; + end if; + end Collect_Interfaces; + + ------------------------------ + -- Complete_Private_Subtype -- + ------------------------------ + + procedure Complete_Private_Subtype + (Priv : Entity_Id; + Full : Entity_Id; + Full_Base : Entity_Id; + Related_Nod : Node_Id) + is + Save_Next_Entity : Entity_Id; + Save_Homonym : Entity_Id; + + begin + -- Set semantic attributes for (implicit) private subtype completion. + -- If the full type has no discriminants, then it is a copy of the full + -- view of the base. Otherwise, it is a subtype of the base with a + -- possible discriminant constraint. Save and restore the original + -- Next_Entity field of full to ensure that the calls to Copy_Node + -- do not corrupt the entity chain. + + -- Note that the type of the full view is the same entity as the type of + -- the partial view. In this fashion, the subtype has access to the + -- correct view of the parent. + + Save_Next_Entity := Next_Entity (Full); + Save_Homonym := Homonym (Priv); + + case Ekind (Full_Base) is + when E_Record_Type | + E_Record_Subtype | + Class_Wide_Kind | + Private_Kind | + Task_Kind | + Protected_Kind => + Copy_Node (Priv, Full); + + Set_Has_Discriminants (Full, Has_Discriminants (Full_Base)); + Set_First_Entity (Full, First_Entity (Full_Base)); + Set_Last_Entity (Full, Last_Entity (Full_Base)); + + when others => + Copy_Node (Full_Base, Full); + Set_Chars (Full, Chars (Priv)); + Conditional_Delay (Full, Priv); + Set_Sloc (Full, Sloc (Priv)); + end case; + + Set_Next_Entity (Full, Save_Next_Entity); + Set_Homonym (Full, Save_Homonym); + Set_Associated_Node_For_Itype (Full, Related_Nod); + + -- Set common attributes for all subtypes + + Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base))); + + -- The Etype of the full view is inconsistent. Gigi needs to see the + -- structural full view, which is what the current scheme gives: + -- the Etype of the full view is the etype of the full base. However, + -- if the full base is a derived type, the full view then looks like + -- a subtype of the parent, not a subtype of the full base. If instead + -- we write: + + -- Set_Etype (Full, Full_Base); + + -- then we get inconsistencies in the front-end (confusion between + -- views). Several outstanding bugs are related to this ??? + + Set_Is_First_Subtype (Full, False); + Set_Scope (Full, Scope (Priv)); + Set_Size_Info (Full, Full_Base); + Set_RM_Size (Full, RM_Size (Full_Base)); + Set_Is_Itype (Full); + + -- A subtype of a private-type-without-discriminants, whose full-view + -- has discriminants with default expressions, is not constrained! + + if not Has_Discriminants (Priv) then + Set_Is_Constrained (Full, Is_Constrained (Full_Base)); + + if Has_Discriminants (Full_Base) then + Set_Discriminant_Constraint + (Full, Discriminant_Constraint (Full_Base)); + + -- The partial view may have been indefinite, the full view + -- might not be. + + Set_Has_Unknown_Discriminants + (Full, Has_Unknown_Discriminants (Full_Base)); + end if; + end if; + + Set_First_Rep_Item (Full, First_Rep_Item (Full_Base)); + Set_Depends_On_Private (Full, Has_Private_Component (Full)); + + -- Freeze the private subtype entity if its parent is delayed, and not + -- already frozen. We skip this processing if the type is an anonymous + -- subtype of a record component, or is the corresponding record of a + -- protected type, since ??? + + if not Is_Type (Scope (Full)) then + Set_Has_Delayed_Freeze (Full, + Has_Delayed_Freeze (Full_Base) + and then (not Is_Frozen (Full_Base))); + end if; + + Set_Freeze_Node (Full, Empty); + Set_Is_Frozen (Full, False); + Set_Full_View (Priv, Full); + + if Has_Discriminants (Full) then + Set_Stored_Constraint_From_Discriminant_Constraint (Full); + Set_Stored_Constraint (Priv, Stored_Constraint (Full)); + + if Has_Unknown_Discriminants (Full) then + Set_Discriminant_Constraint (Full, No_Elist); + end if; + end if; + + if Ekind (Full_Base) = E_Record_Type + and then Has_Discriminants (Full_Base) + and then Has_Discriminants (Priv) -- might not, if errors + and then not Has_Unknown_Discriminants (Priv) + and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv)) + then + Create_Constrained_Components + (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv)); + + -- If the full base is itself derived from private, build a congruent + -- subtype of its underlying type, for use by the back end. For a + -- constrained record component, the declaration cannot be placed on + -- the component list, but it must nevertheless be built an analyzed, to + -- supply enough information for Gigi to compute the size of component. + + elsif Ekind (Full_Base) in Private_Kind + and then Is_Derived_Type (Full_Base) + and then Has_Discriminants (Full_Base) + and then (Ekind (Current_Scope) /= E_Record_Subtype) + then + if not Is_Itype (Priv) + and then + Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication + then + Build_Underlying_Full_View + (Parent (Priv), Full, Etype (Full_Base)); + + elsif Nkind (Related_Nod) = N_Component_Declaration then + Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base)); + end if; + + elsif Is_Record_Type (Full_Base) then + + -- Show Full is simply a renaming of Full_Base + + Set_Cloned_Subtype (Full, Full_Base); + end if; + + -- It is unsafe to share to bounds of a scalar type, because the Itype + -- is elaborated on demand, and if a bound is non-static then different + -- orders of elaboration in different units will lead to different + -- external symbols. + + if Is_Scalar_Type (Full_Base) then + Set_Scalar_Range (Full, + Make_Range (Sloc (Related_Nod), + Low_Bound => + Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)), + High_Bound => + Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base)))); + + -- This completion inherits the bounds of the full parent, but if + -- the parent is an unconstrained floating point type, so is the + -- completion. + + if Is_Floating_Point_Type (Full_Base) then + Set_Includes_Infinities + (Scalar_Range (Full), Has_Infinities (Full_Base)); + end if; + end if; + + -- ??? It seems that a lot of fields are missing that should be copied + -- from Full_Base to Full. Here are some that are introduced in a + -- non-disruptive way but a cleanup is necessary. + + if Is_Tagged_Type (Full_Base) then + Set_Is_Tagged_Type (Full); + Set_Primitive_Operations (Full, Primitive_Operations (Full_Base)); + Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base)); + + -- If this is a subtype of a protected or task type, constrain its + -- corresponding record, unless this is a subtype without constraints, + -- i.e. a simple renaming as with an actual subtype in an instance. + + elsif Is_Concurrent_Type (Full_Base) then + if Has_Discriminants (Full) + and then Present (Corresponding_Record_Type (Full_Base)) + and then + not Is_Empty_Elmt_List (Discriminant_Constraint (Full)) + then + Set_Corresponding_Record_Type (Full, + Constrain_Corresponding_Record + (Full, Corresponding_Record_Type (Full_Base), + Related_Nod, Full_Base)); + + else + Set_Corresponding_Record_Type (Full, + Corresponding_Record_Type (Full_Base)); + end if; + end if; + end Complete_Private_Subtype; + + ------------------------------------- + -- Complete_Subprograms_Derivation -- + ------------------------------------- + + procedure Complete_Subprograms_Derivation + (Partial_View : Entity_Id; + Derived_Type : Entity_Id) + is + Result : constant Elist_Id := New_Elmt_List; + Elmt_P : Elmt_Id; + Elmt_D : Elmt_Id; + Found : Boolean; + Prim_Op : Entity_Id; + E : Entity_Id; + + begin + -- Handle the case in which the full-view is a transitive + -- derivation of the ancestor of the partial view. + + -- type I is interface; + -- type T is new I with ... + + -- package H is + -- type DT is new I with private; + -- private + -- type DT is new T with ... + -- end; + + if Etype (Partial_View) /= Etype (Derived_Type) + and then Is_Interface (Etype (Partial_View)) + and then Is_Ancestor (Etype (Partial_View), Etype (Derived_Type)) + then + return; + end if; + + if Is_Tagged_Type (Partial_View) then + Elmt_P := First_Elmt (Primitive_Operations (Partial_View)); + else + Elmt_P := No_Elmt; + end if; + + -- Inherit primitives declared with the partial-view + + while Present (Elmt_P) loop + Prim_Op := Node (Elmt_P); + Found := False; + Elmt_D := First_Elmt (Primitive_Operations (Derived_Type)); + while Present (Elmt_D) loop + if Node (Elmt_D) = Prim_Op then + Found := True; + exit; + end if; + + Next_Elmt (Elmt_D); + end loop; + + if not Found then + Append_Elmt (Prim_Op, Result); + + -- Search for entries associated with abstract interfaces that + -- have been covered by this primitive + + Elmt_D := First_Elmt (Primitive_Operations (Derived_Type)); + while Present (Elmt_D) loop + E := Node (Elmt_D); + + if Chars (E) = Chars (Prim_Op) + and then Is_Abstract (E) + and then Present (Alias (E)) + and then Present (DTC_Entity (Alias (E))) + and then Is_Interface (Scope (DTC_Entity (Alias (E)))) + then + Remove_Elmt (Primitive_Operations (Derived_Type), Elmt_D); + end if; + + Next_Elmt (Elmt_D); + end loop; + end if; + + Next_Elmt (Elmt_P); + end loop; + + -- Append the entities of the full-view to the list of primitives + -- of derived_type. + + Elmt_D := First_Elmt (Result); + while Present (Elmt_D) loop + Append_Elmt (Node (Elmt_D), Primitive_Operations (Derived_Type)); + Next_Elmt (Elmt_D); + end loop; + end Complete_Subprograms_Derivation; + + ---------------------------- + -- Constant_Redeclaration -- + ---------------------------- + + procedure Constant_Redeclaration + (Id : Entity_Id; + N : Node_Id; + T : out Entity_Id) + is + Prev : constant Entity_Id := Current_Entity_In_Scope (Id); + Obj_Def : constant Node_Id := Object_Definition (N); + New_T : Entity_Id; + + procedure Check_Possible_Deferred_Completion + (Prev_Id : Entity_Id; + Prev_Obj_Def : Node_Id; + Curr_Obj_Def : Node_Id); + -- Determine whether the two object definitions describe the partial + -- and the full view of a constrained deferred constant. Generate + -- a subtype for the full view and verify that it statically matches + -- the subtype of the partial view. + + procedure Check_Recursive_Declaration (Typ : Entity_Id); + -- If deferred constant is an access type initialized with an allocator, + -- check whether there is an illegal recursion in the definition, + -- through a default value of some record subcomponent. This is normally + -- detected when generating init procs, but requires this additional + -- mechanism when expansion is disabled. + + ---------------------------------------- + -- Check_Possible_Deferred_Completion -- + ---------------------------------------- + + procedure Check_Possible_Deferred_Completion + (Prev_Id : Entity_Id; + Prev_Obj_Def : Node_Id; + Curr_Obj_Def : Node_Id) + is + begin + if Nkind (Prev_Obj_Def) = N_Subtype_Indication + and then Present (Constraint (Prev_Obj_Def)) + and then Nkind (Curr_Obj_Def) = N_Subtype_Indication + and then Present (Constraint (Curr_Obj_Def)) + then + declare + Loc : constant Source_Ptr := Sloc (N); + Def_Id : constant Entity_Id := + Make_Defining_Identifier (Loc, + New_Internal_Name ('S')); + Decl : constant Node_Id := + Make_Subtype_Declaration (Loc, + Defining_Identifier => + Def_Id, + Subtype_Indication => + Relocate_Node (Curr_Obj_Def)); + + begin + Insert_Before_And_Analyze (N, Decl); + Set_Etype (Id, Def_Id); + + if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then + Error_Msg_Sloc := Sloc (Prev_Id); + Error_Msg_N ("subtype does not statically match deferred " & + "declaration#", N); + end if; + end; + end if; + end Check_Possible_Deferred_Completion; + + --------------------------------- + -- Check_Recursive_Declaration -- + --------------------------------- + + procedure Check_Recursive_Declaration (Typ : Entity_Id) is + Comp : Entity_Id; + + begin + if Is_Record_Type (Typ) then + Comp := First_Component (Typ); + while Present (Comp) loop + if Comes_From_Source (Comp) then + if Present (Expression (Parent (Comp))) + and then Is_Entity_Name (Expression (Parent (Comp))) + and then Entity (Expression (Parent (Comp))) = Prev + then + Error_Msg_Sloc := Sloc (Parent (Comp)); + Error_Msg_NE + ("illegal circularity with declaration for&#", + N, Comp); + return; + + elsif Is_Record_Type (Etype (Comp)) then + Check_Recursive_Declaration (Etype (Comp)); + end if; + end if; + + Next_Component (Comp); + end loop; + end if; + end Check_Recursive_Declaration; + + -- Start of processing for Constant_Redeclaration + + begin + if Nkind (Parent (Prev)) = N_Object_Declaration then + if Nkind (Object_Definition + (Parent (Prev))) = N_Subtype_Indication + then + -- Find type of new declaration. The constraints of the two + -- views must match statically, but there is no point in + -- creating an itype for the full view. + + if Nkind (Obj_Def) = N_Subtype_Indication then + Find_Type (Subtype_Mark (Obj_Def)); + New_T := Entity (Subtype_Mark (Obj_Def)); + + else + Find_Type (Obj_Def); + New_T := Entity (Obj_Def); + end if; + + T := Etype (Prev); + + else + -- The full view may impose a constraint, even if the partial + -- view does not, so construct the subtype. + + New_T := Find_Type_Of_Object (Obj_Def, N); + T := New_T; + end if; + + else + -- Current declaration is illegal, diagnosed below in Enter_Name + + T := Empty; + New_T := Any_Type; + end if; + + -- If previous full declaration exists, or if a homograph is present, + -- let Enter_Name handle it, either with an error, or with the removal + -- of an overridden implicit subprogram. + + if Ekind (Prev) /= E_Constant + or else Present (Expression (Parent (Prev))) + or else Present (Full_View (Prev)) + then + Enter_Name (Id); + + -- Verify that types of both declarations match, or else that both types + -- are anonymous access types whose designated subtypes statically match + -- (as allowed in Ada 2005 by AI-385). + + elsif Base_Type (Etype (Prev)) /= Base_Type (New_T) + and then + (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type + or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type + or else not Subtypes_Statically_Match + (Designated_Type (Etype (Prev)), + Designated_Type (Etype (New_T)))) + then + Error_Msg_Sloc := Sloc (Prev); + Error_Msg_N ("type does not match declaration#", N); + Set_Full_View (Prev, Id); + Set_Etype (Id, Any_Type); + + -- If so, process the full constant declaration + + else + -- RM 7.4 (6): If the subtype defined by the subtype_indication in + -- the deferred declaration is constrained, then the subtype defined + -- by the subtype_indication in the full declaration shall match it + -- statically. + + Check_Possible_Deferred_Completion + (Prev_Id => Prev, + Prev_Obj_Def => Object_Definition (Parent (Prev)), + Curr_Obj_Def => Obj_Def); + + Set_Full_View (Prev, Id); + Set_Is_Public (Id, Is_Public (Prev)); + Set_Is_Internal (Id); + Append_Entity (Id, Current_Scope); + + -- Check ALIASED present if present before (RM 7.4(7)) + + if Is_Aliased (Prev) + and then not Aliased_Present (N) + then + Error_Msg_Sloc := Sloc (Prev); + Error_Msg_N ("ALIASED required (see declaration#)", N); + end if; + + -- Check that placement is in private part and that the incomplete + -- declaration appeared in the visible part. + + if Ekind (Current_Scope) = E_Package + and then not In_Private_Part (Current_Scope) + then + Error_Msg_Sloc := Sloc (Prev); + Error_Msg_N ("full constant for declaration#" + & " must be in private part", N); + + elsif Ekind (Current_Scope) = E_Package + and then List_Containing (Parent (Prev)) + /= Visible_Declarations + (Specification (Unit_Declaration_Node (Current_Scope))) + then + Error_Msg_N + ("deferred constant must be declared in visible part", + Parent (Prev)); + end if; + + if Is_Access_Type (T) + and then Nkind (Expression (N)) = N_Allocator + then + Check_Recursive_Declaration (Designated_Type (T)); + end if; + end if; + end Constant_Redeclaration; + + ---------------------- + -- Constrain_Access -- + ---------------------- + + procedure Constrain_Access + (Def_Id : in out Entity_Id; + S : Node_Id; + Related_Nod : Node_Id) + is + T : constant Entity_Id := Entity (Subtype_Mark (S)); + Desig_Type : constant Entity_Id := Designated_Type (T); + Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod); + Constraint_OK : Boolean := True; + + function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean; + -- Simple predicate to test for defaulted discriminants + -- Shouldn't this be in sem_util??? + + --------------------------------- + -- Has_Defaulted_Discriminants -- + --------------------------------- + + function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean is + begin + return Has_Discriminants (Typ) + and then Present (First_Discriminant (Typ)) + and then Present + (Discriminant_Default_Value (First_Discriminant (Typ))); + end Has_Defaulted_Discriminants; + + -- Start of processing for Constrain_Access + + begin + if Is_Array_Type (Desig_Type) then + Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P'); + + elsif (Is_Record_Type (Desig_Type) + or else Is_Incomplete_Or_Private_Type (Desig_Type)) + and then not Is_Constrained (Desig_Type) + then + -- ??? The following code is a temporary kludge to ignore a + -- discriminant constraint on access type if it is constraining + -- the current record. Avoid creating the implicit subtype of the + -- record we are currently compiling since right now, we cannot + -- handle these. For now, just return the access type itself. + + if Desig_Type = Current_Scope + and then No (Def_Id) + then + Set_Ekind (Desig_Subtype, E_Record_Subtype); + Def_Id := Entity (Subtype_Mark (S)); + + -- This call added to ensure that the constraint is analyzed + -- (needed for a B test). Note that we still return early from + -- this procedure to avoid recursive processing. ??? + + Constrain_Discriminated_Type + (Desig_Subtype, S, Related_Nod, For_Access => True); + return; + end if; + + if Ekind (T) = E_General_Access_Type + and then Has_Private_Declaration (Desig_Type) + and then In_Open_Scopes (Scope (Desig_Type)) + then + -- Enforce rule that the constraint is illegal if there is + -- an unconstrained view of the designated type. This means + -- that the partial view (either a private type declaration or + -- a derivation from a private type) has no discriminants. + -- (Defect Report 8652/0008, Technical Corrigendum 1, checked + -- by ACATS B371001). + -- Rule updated for Ada 2005: the private type is said to have + -- a constrained partial view, given that objects of the type + -- can be declared. + + declare + Pack : constant Node_Id := + Unit_Declaration_Node (Scope (Desig_Type)); + Decls : List_Id; + Decl : Node_Id; + + begin + if Nkind (Pack) = N_Package_Declaration then + Decls := Visible_Declarations (Specification (Pack)); + Decl := First (Decls); + while Present (Decl) loop + if (Nkind (Decl) = N_Private_Type_Declaration + and then + Chars (Defining_Identifier (Decl)) = + Chars (Desig_Type)) + + or else + (Nkind (Decl) = N_Full_Type_Declaration + and then + Chars (Defining_Identifier (Decl)) = + Chars (Desig_Type) + and then Is_Derived_Type (Desig_Type) + and then + Has_Private_Declaration (Etype (Desig_Type))) + then + if No (Discriminant_Specifications (Decl)) then + Error_Msg_N + ("cannot constrain general access type if " & + "designated type has constrained partial view", + S); + end if; + + exit; + end if; + + Next (Decl); + end loop; + end if; + end; + end if; + + Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod, + For_Access => True); + + elsif (Is_Task_Type (Desig_Type) + or else Is_Protected_Type (Desig_Type)) + and then not Is_Constrained (Desig_Type) + then + Constrain_Concurrent + (Desig_Subtype, S, Related_Nod, Desig_Type, ' '); + + else + Error_Msg_N ("invalid constraint on access type", S); + Desig_Subtype := Desig_Type; -- Ignore invalid constraint. + Constraint_OK := False; + end if; + + if No (Def_Id) then + Def_Id := Create_Itype (E_Access_Subtype, Related_Nod); + else + Set_Ekind (Def_Id, E_Access_Subtype); + end if; + + if Constraint_OK then + Set_Etype (Def_Id, Base_Type (T)); + + if Is_Private_Type (Desig_Type) then + Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod); + end if; + else + Set_Etype (Def_Id, Any_Type); + end if; + + Set_Size_Info (Def_Id, T); + Set_Is_Constrained (Def_Id, Constraint_OK); + Set_Directly_Designated_Type (Def_Id, Desig_Subtype); + Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id)); + Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T)); + + Conditional_Delay (Def_Id, T); + + -- AI-363 : Subtypes of general access types whose designated types have + -- default discriminants are disallowed. In instances, the rule has to + -- be checked against the actual, of which T is the subtype. In a + -- generic body, the rule is checked assuming that the actual type has + -- defaulted discriminants. + + if Ada_Version >= Ada_05 then + if Ekind (Base_Type (T)) = E_General_Access_Type + and then Has_Defaulted_Discriminants (Desig_Type) + then + Error_Msg_N + ("access subype of general access type not allowed", S); + Error_Msg_N ("\ when discriminants have defaults", S); + + elsif Is_Access_Type (T) + and then Is_Generic_Type (Desig_Type) + and then Has_Discriminants (Desig_Type) + and then In_Package_Body (Current_Scope) + then + Error_Msg_N ("access subtype not allowed in generic body", S); + Error_Msg_N + ("\ wben designated type is a discriminated formal", S); + end if; + end if; + end Constrain_Access; + + --------------------- + -- Constrain_Array -- + --------------------- + + procedure Constrain_Array + (Def_Id : in out Entity_Id; + SI : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id; + Suffix : Character) + is + C : constant Node_Id := Constraint (SI); + Number_Of_Constraints : Nat := 0; + Index : Node_Id; + S, T : Entity_Id; + Constraint_OK : Boolean := True; + + begin + T := Entity (Subtype_Mark (SI)); + + if Ekind (T) in Access_Kind then + T := Designated_Type (T); + end if; + + -- If an index constraint follows a subtype mark in a subtype indication + -- then the type or subtype denoted by the subtype mark must not already + -- impose an index constraint. The subtype mark must denote either an + -- unconstrained array type or an access type whose designated type + -- is such an array type... (RM 3.6.1) + + if Is_Constrained (T) then + Error_Msg_N + ("array type is already constrained", Subtype_Mark (SI)); + Constraint_OK := False; + + else + S := First (Constraints (C)); + while Present (S) loop + Number_Of_Constraints := Number_Of_Constraints + 1; + Next (S); + end loop; + + -- In either case, the index constraint must provide a discrete + -- range for each index of the array type and the type of each + -- discrete range must be the same as that of the corresponding + -- index. (RM 3.6.1) + + if Number_Of_Constraints /= Number_Dimensions (T) then + Error_Msg_NE ("incorrect number of index constraints for }", C, T); + Constraint_OK := False; + + else + S := First (Constraints (C)); + Index := First_Index (T); + Analyze (Index); + + -- Apply constraints to each index type + + for J in 1 .. Number_Of_Constraints loop + Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J); + Next (Index); + Next (S); + end loop; + + end if; + end if; + + if No (Def_Id) then + Def_Id := + Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix); + Set_Parent (Def_Id, Related_Nod); + + else + Set_Ekind (Def_Id, E_Array_Subtype); + end if; + + Set_Size_Info (Def_Id, (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + Set_Etype (Def_Id, Base_Type (T)); + + if Constraint_OK then + Set_First_Index (Def_Id, First (Constraints (C))); + else + Set_First_Index (Def_Id, First_Index (T)); + end if; + + Set_Is_Constrained (Def_Id, True); + Set_Is_Aliased (Def_Id, Is_Aliased (T)); + Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id)); + + Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T)); + Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T)); + + -- Build a freeze node if parent still needs one. Also, make sure + -- that the Depends_On_Private status is set (explanation ???) + -- and also that a conditional delay is set. + + Set_Depends_On_Private (Def_Id, Depends_On_Private (T)); + Conditional_Delay (Def_Id, T); + + end Constrain_Array; + + ------------------------------ + -- Constrain_Component_Type -- + ------------------------------ + + function Constrain_Component_Type + (Comp : Entity_Id; + Constrained_Typ : Entity_Id; + Related_Node : Node_Id; + Typ : Entity_Id; + Constraints : Elist_Id) return Entity_Id + is + Loc : constant Source_Ptr := Sloc (Constrained_Typ); + Compon_Type : constant Entity_Id := Etype (Comp); + + function Build_Constrained_Array_Type + (Old_Type : Entity_Id) return Entity_Id; + -- If Old_Type is an array type, one of whose indices is constrained + -- by a discriminant, build an Itype whose constraint replaces the + -- discriminant with its value in the constraint. + + function Build_Constrained_Discriminated_Type + (Old_Type : Entity_Id) return Entity_Id; + -- Ditto for record components + + function Build_Constrained_Access_Type + (Old_Type : Entity_Id) return Entity_Id; + -- Ditto for access types. Makes use of previous two functions, to + -- constrain designated type. + + function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id; + -- T is an array or discriminated type, C is a list of constraints + -- that apply to T. This routine builds the constrained subtype. + + function Is_Discriminant (Expr : Node_Id) return Boolean; + -- Returns True if Expr is a discriminant + + function Get_Discr_Value (Discrim : Entity_Id) return Node_Id; + -- Find the value of discriminant Discrim in Constraint + + ----------------------------------- + -- Build_Constrained_Access_Type -- + ----------------------------------- + + function Build_Constrained_Access_Type + (Old_Type : Entity_Id) return Entity_Id + is + Desig_Type : constant Entity_Id := Designated_Type (Old_Type); + Itype : Entity_Id; + Desig_Subtype : Entity_Id; + Scop : Entity_Id; + + begin + -- if the original access type was not embedded in the enclosing + -- type definition, there is no need to produce a new access + -- subtype. In fact every access type with an explicit constraint + -- generates an itype whose scope is the enclosing record. + + if not Is_Type (Scope (Old_Type)) then + return Old_Type; + + elsif Is_Array_Type (Desig_Type) then + Desig_Subtype := Build_Constrained_Array_Type (Desig_Type); + + elsif Has_Discriminants (Desig_Type) then + + -- This may be an access type to an enclosing record type for + -- which we are constructing the constrained components. Return + -- the enclosing record subtype. This is not always correct, + -- but avoids infinite recursion. ??? + + Desig_Subtype := Any_Type; + + for J in reverse 0 .. Scope_Stack.Last loop + Scop := Scope_Stack.Table (J).Entity; + + if Is_Type (Scop) + and then Base_Type (Scop) = Base_Type (Desig_Type) + then + Desig_Subtype := Scop; + end if; + + exit when not Is_Type (Scop); + end loop; + + if Desig_Subtype = Any_Type then + Desig_Subtype := + Build_Constrained_Discriminated_Type (Desig_Type); + end if; + + else + return Old_Type; + end if; + + if Desig_Subtype /= Desig_Type then + + -- The Related_Node better be here or else we won't be able + -- to attach new itypes to a node in the tree. + + pragma Assert (Present (Related_Node)); + + Itype := Create_Itype (E_Access_Subtype, Related_Node); + + Set_Etype (Itype, Base_Type (Old_Type)); + Set_Size_Info (Itype, (Old_Type)); + Set_Directly_Designated_Type (Itype, Desig_Subtype); + Set_Depends_On_Private (Itype, Has_Private_Component + (Old_Type)); + Set_Is_Access_Constant (Itype, Is_Access_Constant + (Old_Type)); + + -- The new itype needs freezing when it depends on a not frozen + -- type and the enclosing subtype needs freezing. + + if Has_Delayed_Freeze (Constrained_Typ) + and then not Is_Frozen (Constrained_Typ) + then + Conditional_Delay (Itype, Base_Type (Old_Type)); + end if; + + return Itype; + + else + return Old_Type; + end if; + end Build_Constrained_Access_Type; + + ---------------------------------- + -- Build_Constrained_Array_Type -- + ---------------------------------- + + function Build_Constrained_Array_Type + (Old_Type : Entity_Id) return Entity_Id + is + Lo_Expr : Node_Id; + Hi_Expr : Node_Id; + Old_Index : Node_Id; + Range_Node : Node_Id; + Constr_List : List_Id; + + Need_To_Create_Itype : Boolean := False; + + begin + Old_Index := First_Index (Old_Type); + while Present (Old_Index) loop + Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr); + + if Is_Discriminant (Lo_Expr) + or else Is_Discriminant (Hi_Expr) + then + Need_To_Create_Itype := True; + end if; + + Next_Index (Old_Index); + end loop; + + if Need_To_Create_Itype then + Constr_List := New_List; + + Old_Index := First_Index (Old_Type); + while Present (Old_Index) loop + Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr); + + if Is_Discriminant (Lo_Expr) then + Lo_Expr := Get_Discr_Value (Lo_Expr); + end if; + + if Is_Discriminant (Hi_Expr) then + Hi_Expr := Get_Discr_Value (Hi_Expr); + end if; + + Range_Node := + Make_Range + (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr)); + + Append (Range_Node, To => Constr_List); + + Next_Index (Old_Index); + end loop; + + return Build_Subtype (Old_Type, Constr_List); + + else + return Old_Type; + end if; + end Build_Constrained_Array_Type; + + ------------------------------------------ + -- Build_Constrained_Discriminated_Type -- + ------------------------------------------ + + function Build_Constrained_Discriminated_Type + (Old_Type : Entity_Id) return Entity_Id + is + Expr : Node_Id; + Constr_List : List_Id; + Old_Constraint : Elmt_Id; + + Need_To_Create_Itype : Boolean := False; + + begin + Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type)); + while Present (Old_Constraint) loop + Expr := Node (Old_Constraint); + + if Is_Discriminant (Expr) then + Need_To_Create_Itype := True; + end if; + + Next_Elmt (Old_Constraint); + end loop; + + if Need_To_Create_Itype then + Constr_List := New_List; + + Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type)); + while Present (Old_Constraint) loop + Expr := Node (Old_Constraint); + + if Is_Discriminant (Expr) then + Expr := Get_Discr_Value (Expr); + end if; + + Append (New_Copy_Tree (Expr), To => Constr_List); + + Next_Elmt (Old_Constraint); + end loop; + + return Build_Subtype (Old_Type, Constr_List); + + else + return Old_Type; + end if; + end Build_Constrained_Discriminated_Type; + + ------------------- + -- Build_Subtype -- + ------------------- + + function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is + Indic : Node_Id; + Subtyp_Decl : Node_Id; + Def_Id : Entity_Id; + Btyp : Entity_Id := Base_Type (T); + + begin + -- The Related_Node better be here or else we won't be able to + -- attach new itypes to a node in the tree. + + pragma Assert (Present (Related_Node)); + + -- If the view of the component's type is incomplete or private + -- with unknown discriminants, then the constraint must be applied + -- to the full type. + + if Has_Unknown_Discriminants (Btyp) + and then Present (Underlying_Type (Btyp)) + then + Btyp := Underlying_Type (Btyp); + end if; + + Indic := + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Occurrence_Of (Btyp, Loc), + Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C)); + + Def_Id := Create_Itype (Ekind (T), Related_Node); + + Subtyp_Decl := + Make_Subtype_Declaration (Loc, + Defining_Identifier => Def_Id, + Subtype_Indication => Indic); + + Set_Parent (Subtyp_Decl, Parent (Related_Node)); + + -- Itypes must be analyzed with checks off (see package Itypes) + + Analyze (Subtyp_Decl, Suppress => All_Checks); + + return Def_Id; + end Build_Subtype; + + --------------------- + -- Get_Discr_Value -- + --------------------- + + function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is + D : Entity_Id; + E : Elmt_Id; + G : Elmt_Id; + + begin + -- The discriminant may be declared for the type, in which case we + -- find it by iterating over the list of discriminants. If the + -- discriminant is inherited from a parent type, it appears as the + -- corresponding discriminant of the current type. This will be the + -- case when constraining an inherited component whose constraint is + -- given by a discriminant of the parent. + + D := First_Discriminant (Typ); + E := First_Elmt (Constraints); + while Present (D) loop + if D = Entity (Discrim) + or else Corresponding_Discriminant (D) = Entity (Discrim) + then + return Node (E); + end if; + + Next_Discriminant (D); + Next_Elmt (E); + end loop; + + -- The corresponding_Discriminant mechanism is incomplete, because + -- the correspondence between new and old discriminants is not one + -- to one: one new discriminant can constrain several old ones. In + -- that case, scan sequentially the stored_constraint, the list of + -- discriminants of the parents, and the constraints. + + if Is_Derived_Type (Typ) + and then Present (Stored_Constraint (Typ)) + and then Scope (Entity (Discrim)) = Etype (Typ) + then + D := First_Discriminant (Etype (Typ)); + E := First_Elmt (Constraints); + G := First_Elmt (Stored_Constraint (Typ)); + while Present (D) loop + if D = Entity (Discrim) then + return Node (E); + end if; + + Next_Discriminant (D); + Next_Elmt (E); + Next_Elmt (G); + end loop; + end if; + + -- Something is wrong if we did not find the value + + raise Program_Error; + end Get_Discr_Value; + + --------------------- + -- Is_Discriminant -- + --------------------- + + function Is_Discriminant (Expr : Node_Id) return Boolean is + Discrim_Scope : Entity_Id; + + begin + if Denotes_Discriminant (Expr) then + Discrim_Scope := Scope (Entity (Expr)); + + -- Either we have a reference to one of Typ's discriminants, + + pragma Assert (Discrim_Scope = Typ + + -- or to the discriminants of the parent type, in the case + -- of a derivation of a tagged type with variants. + + or else Discrim_Scope = Etype (Typ) + or else Full_View (Discrim_Scope) = Etype (Typ) + + -- or same as above for the case where the discriminants + -- were declared in Typ's private view. + + or else (Is_Private_Type (Discrim_Scope) + and then Chars (Discrim_Scope) = Chars (Typ)) + + -- or else we are deriving from the full view and the + -- discriminant is declared in the private entity. + + or else (Is_Private_Type (Typ) + and then Chars (Discrim_Scope) = Chars (Typ)) + + -- or we have a class-wide type, in which case make sure the + -- discriminant found belongs to the root type. + + or else (Is_Class_Wide_Type (Typ) + and then Etype (Typ) = Discrim_Scope)); + + return True; + end if; + + -- In all other cases we have something wrong + + return False; + end Is_Discriminant; + + -- Start of processing for Constrain_Component_Type + + begin + if Nkind (Parent (Comp)) = N_Component_Declaration + and then Comes_From_Source (Parent (Comp)) + and then Comes_From_Source + (Subtype_Indication (Component_Definition (Parent (Comp)))) + and then + Is_Entity_Name + (Subtype_Indication (Component_Definition (Parent (Comp)))) + then + return Compon_Type; + + elsif Is_Array_Type (Compon_Type) then + return Build_Constrained_Array_Type (Compon_Type); + + elsif Has_Discriminants (Compon_Type) then + return Build_Constrained_Discriminated_Type (Compon_Type); + + elsif Is_Access_Type (Compon_Type) then + return Build_Constrained_Access_Type (Compon_Type); + + else + return Compon_Type; + end if; + end Constrain_Component_Type; + + -------------------------- + -- Constrain_Concurrent -- + -------------------------- + + -- For concurrent types, the associated record value type carries the same + -- discriminants, so when we constrain a concurrent type, we must constrain + -- the corresponding record type as well. + + procedure Constrain_Concurrent + (Def_Id : in out Entity_Id; + SI : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id; + Suffix : Character) + is + T_Ent : Entity_Id := Entity (Subtype_Mark (SI)); + T_Val : Entity_Id; + + begin + if Ekind (T_Ent) in Access_Kind then + T_Ent := Designated_Type (T_Ent); + end if; + + T_Val := Corresponding_Record_Type (T_Ent); + + if Present (T_Val) then + + if No (Def_Id) then + Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); + end if; + + Constrain_Discriminated_Type (Def_Id, SI, Related_Nod); + + Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id)); + Set_Corresponding_Record_Type (Def_Id, + Constrain_Corresponding_Record + (Def_Id, T_Val, Related_Nod, Related_Id)); + + else + -- If there is no associated record, expansion is disabled and this + -- is a generic context. Create a subtype in any case, so that + -- semantic analysis can proceed. + + if No (Def_Id) then + Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); + end if; + + Constrain_Discriminated_Type (Def_Id, SI, Related_Nod); + end if; + end Constrain_Concurrent; + + ------------------------------------ + -- Constrain_Corresponding_Record -- + ------------------------------------ + + function Constrain_Corresponding_Record + (Prot_Subt : Entity_Id; + Corr_Rec : Entity_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id) return Entity_Id + is + T_Sub : constant Entity_Id := + Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V'); + + begin + Set_Etype (T_Sub, Corr_Rec); + Init_Size_Align (T_Sub); + Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt)); + Set_Is_Constrained (T_Sub, True); + Set_First_Entity (T_Sub, First_Entity (Corr_Rec)); + Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec)); + + Conditional_Delay (T_Sub, Corr_Rec); + + if Has_Discriminants (Prot_Subt) then -- False only if errors. + Set_Discriminant_Constraint + (T_Sub, Discriminant_Constraint (Prot_Subt)); + Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub); + Create_Constrained_Components + (T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub)); + end if; + + Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub)); + + return T_Sub; + end Constrain_Corresponding_Record; + + ----------------------- + -- Constrain_Decimal -- + ----------------------- + + procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is + T : constant Entity_Id := Entity (Subtype_Mark (S)); + C : constant Node_Id := Constraint (S); + Loc : constant Source_Ptr := Sloc (C); + Range_Expr : Node_Id; + Digits_Expr : Node_Id; + Digits_Val : Uint; + Bound_Val : Ureal; + + begin + Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype); + + if Nkind (C) = N_Range_Constraint then + Range_Expr := Range_Expression (C); + Digits_Val := Digits_Value (T); + + else + pragma Assert (Nkind (C) = N_Digits_Constraint); + Digits_Expr := Digits_Expression (C); + Analyze_And_Resolve (Digits_Expr, Any_Integer); + + Check_Digits_Expression (Digits_Expr); + Digits_Val := Expr_Value (Digits_Expr); + + if Digits_Val > Digits_Value (T) then + Error_Msg_N + ("digits expression is incompatible with subtype", C); + Digits_Val := Digits_Value (T); + end if; + + if Present (Range_Constraint (C)) then + Range_Expr := Range_Expression (Range_Constraint (C)); + else + Range_Expr := Empty; + end if; + end if; + + Set_Etype (Def_Id, Base_Type (T)); + Set_Size_Info (Def_Id, (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + Set_Delta_Value (Def_Id, Delta_Value (T)); + Set_Scale_Value (Def_Id, Scale_Value (T)); + Set_Small_Value (Def_Id, Small_Value (T)); + Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T)); + Set_Digits_Value (Def_Id, Digits_Val); + + -- Manufacture range from given digits value if no range present + + if No (Range_Expr) then + Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T); + Range_Expr := + Make_Range (Loc, + Low_Bound => + Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))), + High_Bound => + Convert_To (T, Make_Real_Literal (Loc, Bound_Val))); + end if; + + Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T); + Set_Discrete_RM_Size (Def_Id); + + -- Unconditionally delay the freeze, since we cannot set size + -- information in all cases correctly until the freeze point. + + Set_Has_Delayed_Freeze (Def_Id); + end Constrain_Decimal; + + ---------------------------------- + -- Constrain_Discriminated_Type -- + ---------------------------------- + + procedure Constrain_Discriminated_Type + (Def_Id : Entity_Id; + S : Node_Id; + Related_Nod : Node_Id; + For_Access : Boolean := False) + is + E : constant Entity_Id := Entity (Subtype_Mark (S)); + T : Entity_Id; + C : Node_Id; + Elist : Elist_Id := New_Elmt_List; + + procedure Fixup_Bad_Constraint; + -- This is called after finding a bad constraint, and after having + -- posted an appropriate error message. The mission is to leave the + -- entity T in as reasonable state as possible! + + -------------------------- + -- Fixup_Bad_Constraint -- + -------------------------- + + procedure Fixup_Bad_Constraint is + begin + -- Set a reasonable Ekind for the entity. For an incomplete type, + -- we can't do much, but for other types, we can set the proper + -- corresponding subtype kind. + + if Ekind (T) = E_Incomplete_Type then + Set_Ekind (Def_Id, Ekind (T)); + else + Set_Ekind (Def_Id, Subtype_Kind (Ekind (T))); + end if; + + Set_Etype (Def_Id, Any_Type); + Set_Error_Posted (Def_Id); + end Fixup_Bad_Constraint; + + -- Start of processing for Constrain_Discriminated_Type + + begin + C := Constraint (S); + + -- A discriminant constraint is only allowed in a subtype indication, + -- after a subtype mark. This subtype mark must denote either a type + -- with discriminants, or an access type whose designated type is a + -- type with discriminants. A discriminant constraint specifies the + -- values of these discriminants (RM 3.7.2(5)). + + T := Base_Type (Entity (Subtype_Mark (S))); + + if Ekind (T) in Access_Kind then + T := Designated_Type (T); + end if; + + -- Check that the type has visible discriminants. The type may be + -- a private type with unknown discriminants whose full view has + -- discriminants which are invisible. + + if not Has_Discriminants (T) + or else + (Has_Unknown_Discriminants (T) + and then Is_Private_Type (T)) + then + Error_Msg_N ("invalid constraint: type has no discriminant", C); + Fixup_Bad_Constraint; + return; + + elsif Is_Constrained (E) + or else (Ekind (E) = E_Class_Wide_Subtype + and then Present (Discriminant_Constraint (E))) + then + Error_Msg_N ("type is already constrained", Subtype_Mark (S)); + Fixup_Bad_Constraint; + return; + end if; + + -- T may be an unconstrained subtype (e.g. a generic actual). + -- Constraint applies to the base type. + + T := Base_Type (T); + + Elist := Build_Discriminant_Constraints (T, S); + + -- If the list returned was empty we had an error in building the + -- discriminant constraint. We have also already signalled an error + -- in the incomplete type case + + if Is_Empty_Elmt_List (Elist) then + Fixup_Bad_Constraint; + return; + end if; + + Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access); + end Constrain_Discriminated_Type; + + --------------------------- + -- Constrain_Enumeration -- + --------------------------- + + procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is + T : constant Entity_Id := Entity (Subtype_Mark (S)); + C : constant Node_Id := Constraint (S); + + begin + Set_Ekind (Def_Id, E_Enumeration_Subtype); + + Set_First_Literal (Def_Id, First_Literal (Base_Type (T))); + + Set_Etype (Def_Id, Base_Type (T)); + Set_Size_Info (Def_Id, (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + Set_Is_Character_Type (Def_Id, Is_Character_Type (T)); + + Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); + + Set_Discrete_RM_Size (Def_Id); + end Constrain_Enumeration; + + ---------------------- + -- Constrain_Float -- + ---------------------- + + procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is + T : constant Entity_Id := Entity (Subtype_Mark (S)); + C : Node_Id; + D : Node_Id; + Rais : Node_Id; + + begin + Set_Ekind (Def_Id, E_Floating_Point_Subtype); + + Set_Etype (Def_Id, Base_Type (T)); + Set_Size_Info (Def_Id, (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + + -- Process the constraint + + C := Constraint (S); + + -- Digits constraint present + + if Nkind (C) = N_Digits_Constraint then + Check_Restriction (No_Obsolescent_Features, C); + + if Warn_On_Obsolescent_Feature then + Error_Msg_N + ("subtype digits constraint is an " & + "obsolescent feature ('R'M 'J.3(8))?", C); + end if; + + D := Digits_Expression (C); + Analyze_And_Resolve (D, Any_Integer); + Check_Digits_Expression (D); + Set_Digits_Value (Def_Id, Expr_Value (D)); + + -- Check that digits value is in range. Obviously we can do this + -- at compile time, but it is strictly a runtime check, and of + -- course there is an ACVC test that checks this! + + if Digits_Value (Def_Id) > Digits_Value (T) then + Error_Msg_Uint_1 := Digits_Value (T); + Error_Msg_N ("?digits value is too large, maximum is ^", D); + Rais := + Make_Raise_Constraint_Error (Sloc (D), + Reason => CE_Range_Check_Failed); + Insert_Action (Declaration_Node (Def_Id), Rais); + end if; + + C := Range_Constraint (C); + + -- No digits constraint present + + else + Set_Digits_Value (Def_Id, Digits_Value (T)); + end if; + + -- Range constraint present + + if Nkind (C) = N_Range_Constraint then + Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); + + -- No range constraint present + + else + pragma Assert (No (C)); + Set_Scalar_Range (Def_Id, Scalar_Range (T)); + end if; + + Set_Is_Constrained (Def_Id); + end Constrain_Float; + + --------------------- + -- Constrain_Index -- + --------------------- + + procedure Constrain_Index + (Index : Node_Id; + S : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id; + Suffix : Character; + Suffix_Index : Nat) + is + Def_Id : Entity_Id; + R : Node_Id := Empty; + T : constant Entity_Id := Etype (Index); + + begin + if Nkind (S) = N_Range + or else + (Nkind (S) = N_Attribute_Reference + and then Attribute_Name (S) = Name_Range) + then + -- A Range attribute will transformed into N_Range by Resolve + + Analyze (S); + Set_Etype (S, T); + R := S; + + Process_Range_Expr_In_Decl (R, T, Empty_List); + + if not Error_Posted (S) + and then + (Nkind (S) /= N_Range + or else not Covers (T, (Etype (Low_Bound (S)))) + or else not Covers (T, (Etype (High_Bound (S))))) + then + if Base_Type (T) /= Any_Type + and then Etype (Low_Bound (S)) /= Any_Type + and then Etype (High_Bound (S)) /= Any_Type + then + Error_Msg_N ("range expected", S); + end if; + end if; + + elsif Nkind (S) = N_Subtype_Indication then + + -- The parser has verified that this is a discrete indication + + Resolve_Discrete_Subtype_Indication (S, T); + R := Range_Expression (Constraint (S)); + + elsif Nkind (S) = N_Discriminant_Association then + + -- Syntactically valid in subtype indication + + Error_Msg_N ("invalid index constraint", S); + Rewrite (S, New_Occurrence_Of (T, Sloc (S))); + return; + + -- Subtype_Mark case, no anonymous subtypes to construct + + else + Analyze (S); + + if Is_Entity_Name (S) then + if not Is_Type (Entity (S)) then + Error_Msg_N ("expect subtype mark for index constraint", S); + + elsif Base_Type (Entity (S)) /= Base_Type (T) then + Wrong_Type (S, Base_Type (T)); + end if; + + return; + + else + Error_Msg_N ("invalid index constraint", S); + Rewrite (S, New_Occurrence_Of (T, Sloc (S))); + return; + end if; + end if; + + Def_Id := + Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index); + + Set_Etype (Def_Id, Base_Type (T)); + + if Is_Modular_Integer_Type (T) then + Set_Ekind (Def_Id, E_Modular_Integer_Subtype); + + elsif Is_Integer_Type (T) then + Set_Ekind (Def_Id, E_Signed_Integer_Subtype); + + else + Set_Ekind (Def_Id, E_Enumeration_Subtype); + Set_Is_Character_Type (Def_Id, Is_Character_Type (T)); + end if; + + Set_Size_Info (Def_Id, (T)); + Set_RM_Size (Def_Id, RM_Size (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + + Set_Scalar_Range (Def_Id, R); + + Set_Etype (S, Def_Id); + Set_Discrete_RM_Size (Def_Id); + end Constrain_Index; + + ----------------------- + -- Constrain_Integer -- + ----------------------- + + procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is + T : constant Entity_Id := Entity (Subtype_Mark (S)); + C : constant Node_Id := Constraint (S); + + begin + Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); + + if Is_Modular_Integer_Type (T) then + Set_Ekind (Def_Id, E_Modular_Integer_Subtype); + else + Set_Ekind (Def_Id, E_Signed_Integer_Subtype); + end if; + + Set_Etype (Def_Id, Base_Type (T)); + Set_Size_Info (Def_Id, (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + Set_Discrete_RM_Size (Def_Id); + end Constrain_Integer; + + ------------------------------ + -- Constrain_Ordinary_Fixed -- + ------------------------------ + + procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is + T : constant Entity_Id := Entity (Subtype_Mark (S)); + C : Node_Id; + D : Node_Id; + Rais : Node_Id; + + begin + Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype); + Set_Etype (Def_Id, Base_Type (T)); + Set_Size_Info (Def_Id, (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + Set_Small_Value (Def_Id, Small_Value (T)); + + -- Process the constraint + + C := Constraint (S); + + -- Delta constraint present + + if Nkind (C) = N_Delta_Constraint then + Check_Restriction (No_Obsolescent_Features, C); + + if Warn_On_Obsolescent_Feature then + Error_Msg_S + ("subtype delta constraint is an " & + "obsolescent feature ('R'M 'J.3(7))?"); + end if; + + D := Delta_Expression (C); + Analyze_And_Resolve (D, Any_Real); + Check_Delta_Expression (D); + Set_Delta_Value (Def_Id, Expr_Value_R (D)); + + -- Check that delta value is in range. Obviously we can do this + -- at compile time, but it is strictly a runtime check, and of + -- course there is an ACVC test that checks this! + + if Delta_Value (Def_Id) < Delta_Value (T) then + Error_Msg_N ("?delta value is too small", D); + Rais := + Make_Raise_Constraint_Error (Sloc (D), + Reason => CE_Range_Check_Failed); + Insert_Action (Declaration_Node (Def_Id), Rais); + end if; + + C := Range_Constraint (C); + + -- No delta constraint present + + else + Set_Delta_Value (Def_Id, Delta_Value (T)); + end if; + + -- Range constraint present + + if Nkind (C) = N_Range_Constraint then + Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T); + + -- No range constraint present + + else + pragma Assert (No (C)); + Set_Scalar_Range (Def_Id, Scalar_Range (T)); + + end if; + + Set_Discrete_RM_Size (Def_Id); + + -- Unconditionally delay the freeze, since we cannot set size + -- information in all cases correctly until the freeze point. + + Set_Has_Delayed_Freeze (Def_Id); + end Constrain_Ordinary_Fixed; + + --------------------------- + -- Convert_Scalar_Bounds -- + --------------------------- + + procedure Convert_Scalar_Bounds + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Loc : Source_Ptr) + is + Implicit_Base : constant Entity_Id := Base_Type (Derived_Type); + + Lo : Node_Id; + Hi : Node_Id; + Rng : Node_Id; + + begin + Lo := Build_Scalar_Bound + (Type_Low_Bound (Derived_Type), + Parent_Type, Implicit_Base); + + Hi := Build_Scalar_Bound + (Type_High_Bound (Derived_Type), + Parent_Type, Implicit_Base); + + Rng := + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi); + + Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type)); + + Set_Parent (Rng, N); + Set_Scalar_Range (Derived_Type, Rng); + + -- Analyze the bounds + + Analyze_And_Resolve (Lo, Implicit_Base); + Analyze_And_Resolve (Hi, Implicit_Base); + + -- Analyze the range itself, except that we do not analyze it if + -- the bounds are real literals, and we have a fixed-point type. + -- The reason for this is that we delay setting the bounds in this + -- case till we know the final Small and Size values (see circuit + -- in Freeze.Freeze_Fixed_Point_Type for further details). + + if Is_Fixed_Point_Type (Parent_Type) + and then Nkind (Lo) = N_Real_Literal + and then Nkind (Hi) = N_Real_Literal + then + return; + + -- Here we do the analysis of the range + + -- Note: we do this manually, since if we do a normal Analyze and + -- Resolve call, there are problems with the conversions used for + -- the derived type range. + + else + Set_Etype (Rng, Implicit_Base); + Set_Analyzed (Rng, True); + end if; + end Convert_Scalar_Bounds; + + ------------------- + -- Copy_And_Swap -- + ------------------- + + procedure Copy_And_Swap (Priv, Full : Entity_Id) is + begin + -- Initialize new full declaration entity by copying the pertinent + -- fields of the corresponding private declaration entity. + + -- We temporarily set Ekind to a value appropriate for a type to + -- avoid assert failures in Einfo from checking for setting type + -- attributes on something that is not a type. Ekind (Priv) is an + -- appropriate choice, since it allowed the attributes to be set + -- in the first place. This Ekind value will be modified later. + + Set_Ekind (Full, Ekind (Priv)); + + -- Also set Etype temporarily to Any_Type, again, in the absence + -- of errors, it will be properly reset, and if there are errors, + -- then we want a value of Any_Type to remain. + + Set_Etype (Full, Any_Type); + + -- Now start copying attributes + + Set_Has_Discriminants (Full, Has_Discriminants (Priv)); + + if Has_Discriminants (Full) then + Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv)); + Set_Stored_Constraint (Full, Stored_Constraint (Priv)); + end if; + + Set_First_Rep_Item (Full, First_Rep_Item (Priv)); + Set_Homonym (Full, Homonym (Priv)); + Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv)); + Set_Is_Public (Full, Is_Public (Priv)); + Set_Is_Pure (Full, Is_Pure (Priv)); + Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv)); + + Conditional_Delay (Full, Priv); + + if Is_Tagged_Type (Full) then + Set_Primitive_Operations (Full, Primitive_Operations (Priv)); + + if Priv = Base_Type (Priv) then + Set_Class_Wide_Type (Full, Class_Wide_Type (Priv)); + end if; + end if; + + Set_Is_Volatile (Full, Is_Volatile (Priv)); + Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv)); + Set_Scope (Full, Scope (Priv)); + Set_Next_Entity (Full, Next_Entity (Priv)); + Set_First_Entity (Full, First_Entity (Priv)); + Set_Last_Entity (Full, Last_Entity (Priv)); + + -- If access types have been recorded for later handling, keep them in + -- the full view so that they get handled when the full view freeze + -- node is expanded. + + if Present (Freeze_Node (Priv)) + and then Present (Access_Types_To_Process (Freeze_Node (Priv))) + then + Ensure_Freeze_Node (Full); + Set_Access_Types_To_Process + (Freeze_Node (Full), + Access_Types_To_Process (Freeze_Node (Priv))); + end if; + + -- Swap the two entities. Now Privat is the full type entity and + -- Full is the private one. They will be swapped back at the end + -- of the private part. This swapping ensures that the entity that + -- is visible in the private part is the full declaration. + + Exchange_Entities (Priv, Full); + Append_Entity (Full, Scope (Full)); + end Copy_And_Swap; + + ------------------------------------- + -- Copy_Array_Base_Type_Attributes -- + ------------------------------------- + + procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is + begin + Set_Component_Alignment (T1, Component_Alignment (T2)); + Set_Component_Type (T1, Component_Type (T2)); + Set_Component_Size (T1, Component_Size (T2)); + Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2)); + Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2)); + Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2)); + Set_Has_Task (T1, Has_Task (T2)); + Set_Is_Packed (T1, Is_Packed (T2)); + Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2)); + Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2)); + Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2)); + end Copy_Array_Base_Type_Attributes; + + ----------------------------------- + -- Copy_Array_Subtype_Attributes -- + ----------------------------------- + + procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is + begin + Set_Size_Info (T1, T2); + + Set_First_Index (T1, First_Index (T2)); + Set_Is_Aliased (T1, Is_Aliased (T2)); + Set_Is_Atomic (T1, Is_Atomic (T2)); + Set_Is_Volatile (T1, Is_Volatile (T2)); + Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2)); + Set_Is_Constrained (T1, Is_Constrained (T2)); + Set_Depends_On_Private (T1, Has_Private_Component (T2)); + Set_First_Rep_Item (T1, First_Rep_Item (T2)); + Set_Convention (T1, Convention (T2)); + Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2)); + Set_Is_Private_Composite (T1, Is_Private_Composite (T2)); + end Copy_Array_Subtype_Attributes; + + ----------------------------------- + -- Create_Constrained_Components -- + ----------------------------------- + + procedure Create_Constrained_Components + (Subt : Entity_Id; + Decl_Node : Node_Id; + Typ : Entity_Id; + Constraints : Elist_Id) + is + Loc : constant Source_Ptr := Sloc (Subt); + Comp_List : constant Elist_Id := New_Elmt_List; + Parent_Type : constant Entity_Id := Etype (Typ); + Assoc_List : constant List_Id := New_List; + Discr_Val : Elmt_Id; + Errors : Boolean; + New_C : Entity_Id; + Old_C : Entity_Id; + Is_Static : Boolean := True; + + procedure Collect_Fixed_Components (Typ : Entity_Id); + -- Collect parent type components that do not appear in a variant part + + procedure Create_All_Components; + -- Iterate over Comp_List to create the components of the subtype + + function Create_Component (Old_Compon : Entity_Id) return Entity_Id; + -- Creates a new component from Old_Compon, copying all the fields from + -- it, including its Etype, inserts the new component in the Subt entity + -- chain and returns the new component. + + function Is_Variant_Record (T : Entity_Id) return Boolean; + -- If true, and discriminants are static, collect only components from + -- variants selected by discriminant values. + + ------------------------------ + -- Collect_Fixed_Components -- + ------------------------------ + + procedure Collect_Fixed_Components (Typ : Entity_Id) is + begin + -- Build association list for discriminants, and find components of the + -- variant part selected by the values of the discriminants. + + Old_C := First_Discriminant (Typ); + Discr_Val := First_Elmt (Constraints); + while Present (Old_C) loop + Append_To (Assoc_List, + Make_Component_Association (Loc, + Choices => New_List (New_Occurrence_Of (Old_C, Loc)), + Expression => New_Copy (Node (Discr_Val)))); + + Next_Elmt (Discr_Val); + Next_Discriminant (Old_C); + end loop; + + -- The tag, and the possible parent and controller components + -- are unconditionally in the subtype. + + if Is_Tagged_Type (Typ) + or else Has_Controlled_Component (Typ) + then + Old_C := First_Component (Typ); + while Present (Old_C) loop + if Chars ((Old_C)) = Name_uTag + or else Chars ((Old_C)) = Name_uParent + or else Chars ((Old_C)) = Name_uController + then + Append_Elmt (Old_C, Comp_List); + end if; + + Next_Component (Old_C); + end loop; + end if; + end Collect_Fixed_Components; + + --------------------------- + -- Create_All_Components -- + --------------------------- + + procedure Create_All_Components is + Comp : Elmt_Id; + + begin + Comp := First_Elmt (Comp_List); + while Present (Comp) loop + Old_C := Node (Comp); + New_C := Create_Component (Old_C); + + Set_Etype + (New_C, + Constrain_Component_Type + (Old_C, Subt, Decl_Node, Typ, Constraints)); + Set_Is_Public (New_C, Is_Public (Subt)); + + Next_Elmt (Comp); + end loop; + end Create_All_Components; + + ---------------------- + -- Create_Component -- + ---------------------- + + function Create_Component (Old_Compon : Entity_Id) return Entity_Id is + New_Compon : constant Entity_Id := New_Copy (Old_Compon); + + begin + if Ekind (Old_Compon) = E_Discriminant + and then Is_Completely_Hidden (Old_Compon) + then + + -- This is a shadow discriminant created for a discriminant of + -- the parent type that is one of several renamed by the same + -- new discriminant. Give the shadow discriminant an internal + -- name that cannot conflict with that of visible components. + + Set_Chars (New_Compon, New_Internal_Name ('C')); + end if; + + -- Set the parent so we have a proper link for freezing etc. This is + -- not a real parent pointer, since of course our parent does not own + -- up to us and reference us, we are an illegitimate child of the + -- original parent! + + Set_Parent (New_Compon, Parent (Old_Compon)); + + -- If the old component's Esize was already determined and is a + -- static value, then the new component simply inherits it. Otherwise + -- the old component's size may require run-time determination, but + -- the new component's size still might be statically determinable + -- (if, for example it has a static constraint). In that case we want + -- Layout_Type to recompute the component's size, so we reset its + -- size and positional fields. + + if Frontend_Layout_On_Target + and then not Known_Static_Esize (Old_Compon) + then + Set_Esize (New_Compon, Uint_0); + Init_Normalized_First_Bit (New_Compon); + Init_Normalized_Position (New_Compon); + Init_Normalized_Position_Max (New_Compon); + end if; + + -- We do not want this node marked as Comes_From_Source, since + -- otherwise it would get first class status and a separate cross- + -- reference line would be generated. Illegitimate children do not + -- rate such recognition. + + Set_Comes_From_Source (New_Compon, False); + + -- But it is a real entity, and a birth certificate must be properly + -- registered by entering it into the entity list. + + Enter_Name (New_Compon); + + return New_Compon; + end Create_Component; + + ----------------------- + -- Is_Variant_Record -- + ----------------------- + + function Is_Variant_Record (T : Entity_Id) return Boolean is + begin + return Nkind (Parent (T)) = N_Full_Type_Declaration + and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition + and then Present (Component_List (Type_Definition (Parent (T)))) + and then Present ( + Variant_Part (Component_List (Type_Definition (Parent (T))))); + end Is_Variant_Record; + + -- Start of processing for Create_Constrained_Components + + begin + pragma Assert (Subt /= Base_Type (Subt)); + pragma Assert (Typ = Base_Type (Typ)); + + Set_First_Entity (Subt, Empty); + Set_Last_Entity (Subt, Empty); + + -- Check whether constraint is fully static, in which case we can + -- optimize the list of components. + + Discr_Val := First_Elmt (Constraints); + while Present (Discr_Val) loop + if not Is_OK_Static_Expression (Node (Discr_Val)) then + Is_Static := False; + exit; + end if; + + Next_Elmt (Discr_Val); + end loop; + + New_Scope (Subt); + + -- Inherit the discriminants of the parent type + + Add_Discriminants : declare + Num_Disc : Int; + Num_Gird : Int; + + begin + Num_Disc := 0; + Old_C := First_Discriminant (Typ); + + while Present (Old_C) loop + Num_Disc := Num_Disc + 1; + New_C := Create_Component (Old_C); + Set_Is_Public (New_C, Is_Public (Subt)); + Next_Discriminant (Old_C); + end loop; + + -- For an untagged derived subtype, the number of discriminants may + -- be smaller than the number of inherited discriminants, because + -- several of them may be renamed by a single new discriminant. + -- In this case, add the hidden discriminants back into the subtype, + -- because otherwise the size of the subtype is computed incorrectly + -- in GCC 4.1. + + Num_Gird := 0; + + if Is_Derived_Type (Typ) + and then not Is_Tagged_Type (Typ) + then + Old_C := First_Stored_Discriminant (Typ); + + while Present (Old_C) loop + Num_Gird := Num_Gird + 1; + Next_Stored_Discriminant (Old_C); + end loop; + end if; + + if Num_Gird > Num_Disc then + + -- Find out multiple uses of new discriminants, and add hidden + -- components for the extra renamed discriminants. We recognize + -- multiple uses through the Corresponding_Discriminant of a + -- new discriminant: if it constrains several old discriminants, + -- this field points to the last one in the parent type. The + -- stored discriminants of the derived type have the same name + -- as those of the parent. + + declare + Constr : Elmt_Id; + New_Discr : Entity_Id; + Old_Discr : Entity_Id; + + begin + Constr := First_Elmt (Stored_Constraint (Typ)); + Old_Discr := First_Stored_Discriminant (Typ); + + while Present (Constr) loop + if Is_Entity_Name (Node (Constr)) + and then Ekind (Entity (Node (Constr))) = E_Discriminant + then + New_Discr := Entity (Node (Constr)); + + if Chars (Corresponding_Discriminant (New_Discr)) + /= Chars (Old_Discr) + then + + -- The new discriminant has been used to rename + -- a subsequent old discriminant. Introduce a shadow + -- component for the current old discriminant. + + New_C := Create_Component (Old_Discr); + Set_Original_Record_Component (New_C, Old_Discr); + end if; + end if; + + Next_Elmt (Constr); + Next_Stored_Discriminant (Old_Discr); + end loop; + end; + end if; + end Add_Discriminants; + + if Is_Static + and then Is_Variant_Record (Typ) + then + Collect_Fixed_Components (Typ); + + Gather_Components ( + Typ, + Component_List (Type_Definition (Parent (Typ))), + Governed_By => Assoc_List, + Into => Comp_List, + Report_Errors => Errors); + pragma Assert (not Errors); + + Create_All_Components; + + -- If the subtype declaration is created for a tagged type derivation + -- with constraints, we retrieve the record definition of the parent + -- type to select the components of the proper variant. + + elsif Is_Static + and then Is_Tagged_Type (Typ) + and then Nkind (Parent (Typ)) = N_Full_Type_Declaration + and then + Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition + and then Is_Variant_Record (Parent_Type) + then + Collect_Fixed_Components (Typ); + + Gather_Components ( + Typ, + Component_List (Type_Definition (Parent (Parent_Type))), + Governed_By => Assoc_List, + Into => Comp_List, + Report_Errors => Errors); + pragma Assert (not Errors); + + -- If the tagged derivation has a type extension, collect all the + -- new components therein. + + if Present + (Record_Extension_Part (Type_Definition (Parent (Typ)))) + then + Old_C := First_Component (Typ); + while Present (Old_C) loop + if Original_Record_Component (Old_C) = Old_C + and then Chars (Old_C) /= Name_uTag + and then Chars (Old_C) /= Name_uParent + and then Chars (Old_C) /= Name_uController + then + Append_Elmt (Old_C, Comp_List); + end if; + + Next_Component (Old_C); + end loop; + end if; + + Create_All_Components; + + else + -- If discriminants are not static, or if this is a multi-level type + -- extension, we have to include all components of the parent type. + + Old_C := First_Component (Typ); + while Present (Old_C) loop + New_C := Create_Component (Old_C); + + Set_Etype + (New_C, + Constrain_Component_Type + (Old_C, Subt, Decl_Node, Typ, Constraints)); + Set_Is_Public (New_C, Is_Public (Subt)); + + Next_Component (Old_C); + end loop; + end if; + + End_Scope; + end Create_Constrained_Components; + + ------------------------------------------ + -- Decimal_Fixed_Point_Type_Declaration -- + ------------------------------------------ + + procedure Decimal_Fixed_Point_Type_Declaration + (T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + Digs_Expr : constant Node_Id := Digits_Expression (Def); + Delta_Expr : constant Node_Id := Delta_Expression (Def); + Implicit_Base : Entity_Id; + Digs_Val : Uint; + Delta_Val : Ureal; + Scale_Val : Uint; + Bound_Val : Ureal; + + -- Start of processing for Decimal_Fixed_Point_Type_Declaration + + begin + Check_Restriction (No_Fixed_Point, Def); + + -- Create implicit base type + + Implicit_Base := + Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B'); + Set_Etype (Implicit_Base, Implicit_Base); + + -- Analyze and process delta expression + + Analyze_And_Resolve (Delta_Expr, Universal_Real); + + Check_Delta_Expression (Delta_Expr); + Delta_Val := Expr_Value_R (Delta_Expr); + + -- Check delta is power of 10, and determine scale value from it + + declare + Val : Ureal; + + begin + Scale_Val := Uint_0; + Val := Delta_Val; + + if Val < Ureal_1 then + while Val < Ureal_1 loop + Val := Val * Ureal_10; + Scale_Val := Scale_Val + 1; + end loop; + + if Scale_Val > 18 then + Error_Msg_N ("scale exceeds maximum value of 18", Def); + Scale_Val := UI_From_Int (+18); + end if; + + else + while Val > Ureal_1 loop + Val := Val / Ureal_10; + Scale_Val := Scale_Val - 1; + end loop; + + if Scale_Val < -18 then + Error_Msg_N ("scale is less than minimum value of -18", Def); + Scale_Val := UI_From_Int (-18); + end if; + end if; + + if Val /= Ureal_1 then + Error_Msg_N ("delta expression must be a power of 10", Def); + Delta_Val := Ureal_10 ** (-Scale_Val); + end if; + end; + + -- Set delta, scale and small (small = delta for decimal type) + + Set_Delta_Value (Implicit_Base, Delta_Val); + Set_Scale_Value (Implicit_Base, Scale_Val); + Set_Small_Value (Implicit_Base, Delta_Val); + + -- Analyze and process digits expression + + Analyze_And_Resolve (Digs_Expr, Any_Integer); + Check_Digits_Expression (Digs_Expr); + Digs_Val := Expr_Value (Digs_Expr); + + if Digs_Val > 18 then + Digs_Val := UI_From_Int (+18); + Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr); + end if; + + Set_Digits_Value (Implicit_Base, Digs_Val); + Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val; + + -- Set range of base type from digits value for now. This will be + -- expanded to represent the true underlying base range by Freeze. + + Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val); + + -- Set size to zero for now, size will be set at freeze time. We have + -- to do this for ordinary fixed-point, because the size depends on + -- the specified small, and we might as well do the same for decimal + -- fixed-point. + + Init_Size_Align (Implicit_Base); + + -- If there are bounds given in the declaration use them as the + -- bounds of the first named subtype. + + if Present (Real_Range_Specification (Def)) then + declare + RRS : constant Node_Id := Real_Range_Specification (Def); + Low : constant Node_Id := Low_Bound (RRS); + High : constant Node_Id := High_Bound (RRS); + Low_Val : Ureal; + High_Val : Ureal; + + begin + Analyze_And_Resolve (Low, Any_Real); + Analyze_And_Resolve (High, Any_Real); + Check_Real_Bound (Low); + Check_Real_Bound (High); + Low_Val := Expr_Value_R (Low); + High_Val := Expr_Value_R (High); + + if Low_Val < (-Bound_Val) then + Error_Msg_N + ("range low bound too small for digits value", Low); + Low_Val := -Bound_Val; + end if; + + if High_Val > Bound_Val then + Error_Msg_N + ("range high bound too large for digits value", High); + High_Val := Bound_Val; + end if; + + Set_Fixed_Range (T, Loc, Low_Val, High_Val); + end; + + -- If no explicit range, use range that corresponds to given + -- digits value. This will end up as the final range for the + -- first subtype. + + else + Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val); + end if; + + -- Complete entity for first subtype + + Set_Ekind (T, E_Decimal_Fixed_Point_Subtype); + Set_Etype (T, Implicit_Base); + Set_Size_Info (T, Implicit_Base); + Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base)); + Set_Digits_Value (T, Digs_Val); + Set_Delta_Value (T, Delta_Val); + Set_Small_Value (T, Delta_Val); + Set_Scale_Value (T, Scale_Val); + Set_Is_Constrained (T); + end Decimal_Fixed_Point_Type_Declaration; + + --------------------------------- + -- Derive_Interface_Subprogram -- + --------------------------------- + + procedure Derive_Interface_Subprograms (Derived_Type : Entity_Id) is + + procedure Do_Derivation (T : Entity_Id); + -- This inner subprograms is used to climb to the ancestors. + -- It is needed to add the derivations to the Derived_Type. + + procedure Do_Derivation (T : Entity_Id) is + Etyp : constant Entity_Id := Etype (T); + AI : Elmt_Id; + + begin + if Etyp /= T + and then Is_Interface (Etyp) + then + Do_Derivation (Etyp); + end if; + + if Present (Abstract_Interfaces (T)) + and then not Is_Empty_Elmt_List (Abstract_Interfaces (T)) + then + AI := First_Elmt (Abstract_Interfaces (T)); + while Present (AI) loop + if not Is_Ancestor (Node (AI), Derived_Type) then + Derive_Subprograms + (Parent_Type => Node (AI), + Derived_Type => Derived_Type, + No_Predefined_Prims => True); + end if; + + Next_Elmt (AI); + end loop; + end if; + end Do_Derivation; + + begin + Do_Derivation (Derived_Type); + + -- At this point the list of primitive operations of Derived_Type + -- contains the entities corresponding to all the subprograms of all the + -- implemented interfaces. If N interfaces have subprograms with the + -- same profile we have N entities in this list because each one must be + -- allocated in its corresponding virtual table. + + -- Its alias attribute references its original interface subprogram. + -- When overridden, the alias attribute is later saved in the + -- Abstract_Interface_Alias attribute. + + end Derive_Interface_Subprograms; + + ----------------------- + -- Derive_Subprogram -- + ----------------------- + + procedure Derive_Subprogram + (New_Subp : in out Entity_Id; + Parent_Subp : Entity_Id; + Derived_Type : Entity_Id; + Parent_Type : Entity_Id; + Actual_Subp : Entity_Id := Empty) + is + Formal : Entity_Id; + New_Formal : Entity_Id; + Visible_Subp : Entity_Id := Parent_Subp; + + function Is_Private_Overriding return Boolean; + -- If Subp is a private overriding of a visible operation, the in- + -- herited operation derives from the overridden op (even though + -- its body is the overriding one) and the inherited operation is + -- visible now. See sem_disp to see the details of the handling of + -- the overridden subprogram, which is removed from the list of + -- primitive operations of the type. The overridden subprogram is + -- saved locally in Visible_Subp, and used to diagnose abstract + -- operations that need overriding in the derived type. + + procedure Replace_Type (Id, New_Id : Entity_Id); + -- When the type is an anonymous access type, create a new access type + -- designating the derived type. + + procedure Set_Derived_Name; + -- This procedure sets the appropriate Chars name for New_Subp. This + -- is normally just a copy of the parent name. An exception arises for + -- type support subprograms, where the name is changed to reflect the + -- name of the derived type, e.g. if type foo is derived from type bar, + -- then a procedure barDA is derived with a name fooDA. + + --------------------------- + -- Is_Private_Overriding -- + --------------------------- + + function Is_Private_Overriding return Boolean is + Prev : Entity_Id; + + begin + -- The visible operation that is overridden is a homonym of the + -- parent subprogram. We scan the homonym chain to find the one + -- whose alias is the subprogram we are deriving. + + Prev := Current_Entity (Parent_Subp); + while Present (Prev) loop + if Is_Dispatching_Operation (Parent_Subp) + and then Present (Prev) + and then Ekind (Prev) = Ekind (Parent_Subp) + and then Alias (Prev) = Parent_Subp + and then Scope (Parent_Subp) = Scope (Prev) + and then + (not Is_Hidden (Prev) + or else + + -- Ada 2005 (AI-251): Entities associated with overridden + -- interface subprograms are always marked as hidden; in + -- this case the field abstract_interface_alias references + -- the original entity (cf. override_dispatching_operation). + + (Atree.Present (Abstract_Interface_Alias (Prev)) + and then not Is_Hidden (Abstract_Interface_Alias (Prev)))) + then + Visible_Subp := Prev; + return True; + end if; + + Prev := Homonym (Prev); + end loop; + + return False; + end Is_Private_Overriding; + + ------------------ + -- Replace_Type -- + ------------------ + + procedure Replace_Type (Id, New_Id : Entity_Id) is + Acc_Type : Entity_Id; + IR : Node_Id; + Par : constant Node_Id := Parent (Derived_Type); + + begin + -- When the type is an anonymous access type, create a new access + -- type designating the derived type. This itype must be elaborated + -- at the point of the derivation, not on subsequent calls that may + -- be out of the proper scope for Gigi, so we insert a reference to + -- it after the derivation. + + if Ekind (Etype (Id)) = E_Anonymous_Access_Type then + declare + Desig_Typ : Entity_Id := Designated_Type (Etype (Id)); + + begin + if Ekind (Desig_Typ) = E_Record_Type_With_Private + and then Present (Full_View (Desig_Typ)) + and then not Is_Private_Type (Parent_Type) + then + Desig_Typ := Full_View (Desig_Typ); + end if; + + if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then + Acc_Type := New_Copy (Etype (Id)); + Set_Etype (Acc_Type, Acc_Type); + Set_Scope (Acc_Type, New_Subp); + + -- Compute size of anonymous access type + + if Is_Array_Type (Desig_Typ) + and then not Is_Constrained (Desig_Typ) + then + Init_Size (Acc_Type, 2 * System_Address_Size); + else + Init_Size (Acc_Type, System_Address_Size); + end if; + + Init_Alignment (Acc_Type); + Set_Directly_Designated_Type (Acc_Type, Derived_Type); + + Set_Etype (New_Id, Acc_Type); + Set_Scope (New_Id, New_Subp); + + -- Create a reference to it + + IR := Make_Itype_Reference (Sloc (Parent (Derived_Type))); + Set_Itype (IR, Acc_Type); + Insert_After (Parent (Derived_Type), IR); + + else + Set_Etype (New_Id, Etype (Id)); + end if; + end; + + elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type) + or else + (Ekind (Etype (Id)) = E_Record_Type_With_Private + and then Present (Full_View (Etype (Id))) + and then + Base_Type (Full_View (Etype (Id))) = Base_Type (Parent_Type)) + then + -- Constraint checks on formals are generated during expansion, + -- based on the signature of the original subprogram. The bounds + -- of the derived type are not relevant, and thus we can use + -- the base type for the formals. However, the return type may be + -- used in a context that requires that the proper static bounds + -- be used (a case statement, for example) and for those cases + -- we must use the derived type (first subtype), not its base. + + -- If the derived_type_definition has no constraints, we know that + -- the derived type has the same constraints as the first subtype + -- of the parent, and we can also use it rather than its base, + -- which can lead to more efficient code. + + if Etype (Id) = Parent_Type then + if Is_Scalar_Type (Parent_Type) + and then + Subtypes_Statically_Compatible (Parent_Type, Derived_Type) + then + Set_Etype (New_Id, Derived_Type); + + elsif Nkind (Par) = N_Full_Type_Declaration + and then + Nkind (Type_Definition (Par)) = N_Derived_Type_Definition + and then + Is_Entity_Name + (Subtype_Indication (Type_Definition (Par))) + then + Set_Etype (New_Id, Derived_Type); + + else + Set_Etype (New_Id, Base_Type (Derived_Type)); + end if; + + else + Set_Etype (New_Id, Base_Type (Derived_Type)); + end if; + + else + Set_Etype (New_Id, Etype (Id)); + end if; + end Replace_Type; + + ---------------------- + -- Set_Derived_Name -- + ---------------------- + + procedure Set_Derived_Name is + Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp); + begin + if Nm = TSS_Null then + Set_Chars (New_Subp, Chars (Parent_Subp)); + else + Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm)); + end if; + end Set_Derived_Name; + + -- Start of processing for Derive_Subprogram + + begin + New_Subp := + New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type)); + Set_Ekind (New_Subp, Ekind (Parent_Subp)); + + -- Check whether the inherited subprogram is a private operation that + -- should be inherited but not yet made visible. Such subprograms can + -- become visible at a later point (e.g., the private part of a public + -- child unit) via Declare_Inherited_Private_Subprograms. If the + -- following predicate is true, then this is not such a private + -- operation and the subprogram simply inherits the name of the parent + -- subprogram. Note the special check for the names of controlled + -- operations, which are currently exempted from being inherited with + -- a hidden name because they must be findable for generation of + -- implicit run-time calls. + + if not Is_Hidden (Parent_Subp) + or else Is_Internal (Parent_Subp) + or else Is_Private_Overriding + or else Is_Internal_Name (Chars (Parent_Subp)) + or else Chars (Parent_Subp) = Name_Initialize + or else Chars (Parent_Subp) = Name_Adjust + or else Chars (Parent_Subp) = Name_Finalize + then + Set_Derived_Name; + + -- If parent is hidden, this can be a regular derivation if the + -- parent is immediately visible in a non-instantiating context, + -- or if we are in the private part of an instance. This test + -- should still be refined ??? + + -- The test for In_Instance_Not_Visible avoids inheriting the derived + -- operation as a non-visible operation in cases where the parent + -- subprogram might not be visible now, but was visible within the + -- original generic, so it would be wrong to make the inherited + -- subprogram non-visible now. (Not clear if this test is fully + -- correct; are there any cases where we should declare the inherited + -- operation as not visible to avoid it being overridden, e.g., when + -- the parent type is a generic actual with private primitives ???) + + -- (they should be treated the same as other private inherited + -- subprograms, but it's not clear how to do this cleanly). ??? + + elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type))) + and then Is_Immediately_Visible (Parent_Subp) + and then not In_Instance) + or else In_Instance_Not_Visible + then + Set_Derived_Name; + + -- The type is inheriting a private operation, so enter + -- it with a special name so it can't be overridden. + + else + Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P')); + end if; + + Set_Parent (New_Subp, Parent (Derived_Type)); + Replace_Type (Parent_Subp, New_Subp); + Conditional_Delay (New_Subp, Parent_Subp); + + Formal := First_Formal (Parent_Subp); + while Present (Formal) loop + New_Formal := New_Copy (Formal); + + -- Normally we do not go copying parents, but in the case of + -- formals, we need to link up to the declaration (which is the + -- parameter specification), and it is fine to link up to the + -- original formal's parameter specification in this case. + + Set_Parent (New_Formal, Parent (Formal)); + + Append_Entity (New_Formal, New_Subp); + + Replace_Type (Formal, New_Formal); + Next_Formal (Formal); + end loop; + + -- If this derivation corresponds to a tagged generic actual, then + -- primitive operations rename those of the actual. Otherwise the + -- primitive operations rename those of the parent type, If the + -- parent renames an intrinsic operator, so does the new subprogram. + -- We except concatenation, which is always properly typed, and does + -- not get expanded as other intrinsic operations. + + if No (Actual_Subp) then + if Is_Intrinsic_Subprogram (Parent_Subp) then + Set_Is_Intrinsic_Subprogram (New_Subp); + + if Present (Alias (Parent_Subp)) + and then Chars (Parent_Subp) /= Name_Op_Concat + then + Set_Alias (New_Subp, Alias (Parent_Subp)); + else + Set_Alias (New_Subp, Parent_Subp); + end if; + + else + Set_Alias (New_Subp, Parent_Subp); + end if; + + else + Set_Alias (New_Subp, Actual_Subp); + end if; + + -- Derived subprograms of a tagged type must inherit the convention + -- of the parent subprogram (a requirement of AI-117). Derived + -- subprograms of untagged types simply get convention Ada by default. + + if Is_Tagged_Type (Derived_Type) then + Set_Convention (New_Subp, Convention (Parent_Subp)); + end if; + + Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp)); + Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp)); + + if Ekind (Parent_Subp) = E_Procedure then + Set_Is_Valued_Procedure + (New_Subp, Is_Valued_Procedure (Parent_Subp)); + end if; + + -- No_Return must be inherited properly. If this is overridden in the + -- case of a dispatching operation, then a check is made in Sem_Disp + -- that the overriding operation is also No_Return (no such check is + -- required for the case of non-dispatching operation. + + Set_No_Return (New_Subp, No_Return (Parent_Subp)); + + -- A derived function with a controlling result is abstract. If the + -- Derived_Type is a nonabstract formal generic derived type, then + -- inherited operations are not abstract: the required check is done at + -- instantiation time. If the derivation is for a generic actual, the + -- function is not abstract unless the actual is. + + if Is_Generic_Type (Derived_Type) + and then not Is_Abstract (Derived_Type) + then + null; + + elsif Is_Abstract (Alias (New_Subp)) + or else (Is_Tagged_Type (Derived_Type) + and then Etype (New_Subp) = Derived_Type + and then No (Actual_Subp)) + then + Set_Is_Abstract (New_Subp); + + -- Finally, if the parent type is abstract we must verify that all + -- inherited operations are either non-abstract or overridden, or + -- that the derived type itself is abstract (this check is performed + -- at the end of a package declaration, in Check_Abstract_Overriding). + -- A private overriding in the parent type will not be visible in the + -- derivation if we are not in an inner package or in a child unit of + -- the parent type, in which case the abstractness of the inherited + -- operation is carried to the new subprogram. + + elsif Is_Abstract (Parent_Type) + and then not In_Open_Scopes (Scope (Parent_Type)) + and then Is_Private_Overriding + and then Is_Abstract (Visible_Subp) + then + Set_Alias (New_Subp, Visible_Subp); + Set_Is_Abstract (New_Subp); + end if; + + New_Overloaded_Entity (New_Subp, Derived_Type); + + -- Check for case of a derived subprogram for the instantiation of a + -- formal derived tagged type, if so mark the subprogram as dispatching + -- and inherit the dispatching attributes of the parent subprogram. The + -- derived subprogram is effectively renaming of the actual subprogram, + -- so it needs to have the same attributes as the actual. + + if Present (Actual_Subp) + and then Is_Dispatching_Operation (Parent_Subp) + then + Set_Is_Dispatching_Operation (New_Subp); + if Present (DTC_Entity (Parent_Subp)) then + Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp)); + Set_DT_Position (New_Subp, DT_Position (Parent_Subp)); + end if; + end if; + + -- Indicate that a derived subprogram does not require a body and that + -- it does not require processing of default expressions. + + Set_Has_Completion (New_Subp); + Set_Default_Expressions_Processed (New_Subp); + + if Ekind (New_Subp) = E_Function then + Set_Mechanism (New_Subp, Mechanism (Parent_Subp)); + end if; + end Derive_Subprogram; + + ------------------------ + -- Derive_Subprograms -- + ------------------------ + + procedure Derive_Subprograms + (Parent_Type : Entity_Id; + Derived_Type : Entity_Id; + Generic_Actual : Entity_Id := Empty; + No_Predefined_Prims : Boolean := False) + is + Op_List : constant Elist_Id := + Collect_Primitive_Operations (Parent_Type); + Act_List : Elist_Id; + Act_Elmt : Elmt_Id; + Elmt : Elmt_Id; + Is_Predef : Boolean; + Subp : Entity_Id; + New_Subp : Entity_Id := Empty; + Parent_Base : Entity_Id; + + begin + if Ekind (Parent_Type) = E_Record_Type_With_Private + and then Has_Discriminants (Parent_Type) + and then Present (Full_View (Parent_Type)) + then + Parent_Base := Full_View (Parent_Type); + else + Parent_Base := Parent_Type; + end if; + + if Present (Generic_Actual) then + Act_List := Collect_Primitive_Operations (Generic_Actual); + Act_Elmt := First_Elmt (Act_List); + else + Act_Elmt := No_Elmt; + end if; + + -- Literals are derived earlier in the process of building the derived + -- type, and are skipped here. + + Elmt := First_Elmt (Op_List); + while Present (Elmt) loop + Subp := Node (Elmt); + + if Ekind (Subp) /= E_Enumeration_Literal then + Is_Predef := + Is_Dispatching_Operation (Subp) + and then Is_Predefined_Dispatching_Operation (Subp); + + if No_Predefined_Prims and then Is_Predef then + null; + + -- We don't need to derive alias entities associated with + -- abstract interfaces + + elsif Is_Dispatching_Operation (Subp) + and then Present (Alias (Subp)) + and then Present (Abstract_Interface_Alias (Subp)) + then + null; + + elsif No (Generic_Actual) then + Derive_Subprogram + (New_Subp, Subp, Derived_Type, Parent_Base); + + else + Derive_Subprogram (New_Subp, Subp, + Derived_Type, Parent_Base, Node (Act_Elmt)); + Next_Elmt (Act_Elmt); + end if; + end if; + + Next_Elmt (Elmt); + end loop; + end Derive_Subprograms; + + -------------------------------- + -- Derived_Standard_Character -- + -------------------------------- + + procedure Derived_Standard_Character + (N : Node_Id; + Parent_Type : Entity_Id; + Derived_Type : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Def : constant Node_Id := Type_Definition (N); + Indic : constant Node_Id := Subtype_Indication (Def); + Parent_Base : constant Entity_Id := Base_Type (Parent_Type); + Implicit_Base : constant Entity_Id := + Create_Itype + (E_Enumeration_Type, N, Derived_Type, 'B'); + + Lo : Node_Id; + Hi : Node_Id; + + begin + Discard_Node (Process_Subtype (Indic, N)); + + Set_Etype (Implicit_Base, Parent_Base); + Set_Size_Info (Implicit_Base, Root_Type (Parent_Type)); + Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type))); + + Set_Is_Character_Type (Implicit_Base, True); + Set_Has_Delayed_Freeze (Implicit_Base); + + -- The bounds of the implicit base are the bounds of the parent base. + -- Note that their type is the parent base. + + Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base)); + Hi := New_Copy_Tree (Type_High_Bound (Parent_Base)); + + Set_Scalar_Range (Implicit_Base, + Make_Range (Loc, + Low_Bound => Lo, + High_Bound => Hi)); + + Conditional_Delay (Derived_Type, Parent_Type); + + Set_Ekind (Derived_Type, E_Enumeration_Subtype); + Set_Etype (Derived_Type, Implicit_Base); + Set_Size_Info (Derived_Type, Parent_Type); + + if Unknown_RM_Size (Derived_Type) then + Set_RM_Size (Derived_Type, RM_Size (Parent_Type)); + end if; + + Set_Is_Character_Type (Derived_Type, True); + + if Nkind (Indic) /= N_Subtype_Indication then + + -- If no explicit constraint, the bounds are those + -- of the parent type. + + Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type)); + Hi := New_Copy_Tree (Type_High_Bound (Parent_Type)); + Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi)); + end if; + + Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc); + + -- Because the implicit base is used in the conversion of the bounds, + -- we have to freeze it now. This is similar to what is done for + -- numeric types, and it equally suspicious, but otherwise a non- + -- static bound will have a reference to an unfrozen type, which is + -- rejected by Gigi (???). + + Freeze_Before (N, Implicit_Base); + end Derived_Standard_Character; + + ------------------------------ + -- Derived_Type_Declaration -- + ------------------------------ + + procedure Derived_Type_Declaration + (T : Entity_Id; + N : Node_Id; + Is_Completion : Boolean) + is + Def : constant Node_Id := Type_Definition (N); + Iface_Def : Node_Id; + Indic : constant Node_Id := Subtype_Indication (Def); + Extension : constant Node_Id := Record_Extension_Part (Def); + Parent_Type : Entity_Id; + Parent_Scope : Entity_Id; + Taggd : Boolean; + + function Comes_From_Generic (Typ : Entity_Id) return Boolean; + -- Check whether the parent type is a generic formal, or derives + -- directly or indirectly from one. + + ------------------------ + -- Comes_From_Generic -- + ------------------------ + + function Comes_From_Generic (Typ : Entity_Id) return Boolean is + begin + if Is_Generic_Type (Typ) then + return True; + + elsif Is_Generic_Type (Root_Type (Parent_Type)) then + return True; + + elsif Is_Private_Type (Typ) + and then Present (Full_View (Typ)) + and then Is_Generic_Type (Root_Type (Full_View (Typ))) + then + return True; + + elsif Is_Generic_Actual_Type (Typ) then + return True; + + else + return False; + end if; + end Comes_From_Generic; + + -- Start of processing for Derived_Type_Declaration + + begin + Parent_Type := Find_Type_Of_Subtype_Indic (Indic); + + -- Ada 2005 (AI-251): In case of interface derivation check that the + -- parent is also an interface. + + if Interface_Present (Def) then + if not Is_Interface (Parent_Type) then + Error_Msg_NE ("(Ada 2005) & must be an interface", + Indic, Parent_Type); + + else + Iface_Def := Type_Definition (Parent (Parent_Type)); + + -- Ada 2005 (AI-251): Limited interfaces can only inherit from + -- other limited interfaces. + + if Limited_Present (Def) then + if Limited_Present (Iface_Def) then + null; + + elsif Protected_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) limited interface cannot" & + " inherit from protected interface", Indic); + + elsif Synchronized_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) limited interface cannot" & + " inherit from synchronized interface", Indic); + + elsif Task_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) limited interface cannot" & + " inherit from task interface", Indic); + + else + Error_Msg_N ("(Ada 2005) limited interface cannot" & + " inherit from non-limited interface", Indic); + end if; + + -- Ada 2005 (AI-345): Non-limited interfaces can only inherit + -- from non-limited or limited interfaces. + + elsif not Protected_Present (Def) + and then not Synchronized_Present (Def) + and then not Task_Present (Def) + then + if Limited_Present (Iface_Def) then + null; + + elsif Protected_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) non-limited interface cannot" & + " inherit from protected interface", Indic); + + elsif Synchronized_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) non-limited interface cannot" & + " inherit from synchronized interface", Indic); + + elsif Task_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) non-limited interface cannot" & + " inherit from task interface", Indic); + + else + null; + end if; + end if; + end if; + end if; + + -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor + -- interfaces + + if Is_Tagged_Type (Parent_Type) + and then Is_Non_Empty_List (Interface_List (Def)) + then + declare + Intf : Node_Id; + T : Entity_Id; + + begin + Intf := First (Interface_List (Def)); + while Present (Intf) loop + T := Find_Type_Of_Subtype_Indic (Intf); + + if not Is_Interface (T) then + Error_Msg_NE ("(Ada 2005) & must be an interface", Intf, T); + + elsif Limited_Present (Def) + and then not Is_Limited_Interface (T) + then + Error_Msg_NE + ("progenitor interface& of limited type must be limited", + N, T); + end if; + + Next (Intf); + end loop; + end; + end if; + + if Parent_Type = Any_Type + or else Etype (Parent_Type) = Any_Type + or else (Is_Class_Wide_Type (Parent_Type) + and then Etype (Parent_Type) = T) + then + -- If Parent_Type is undefined or illegal, make new type into a + -- subtype of Any_Type, and set a few attributes to prevent cascaded + -- errors. If this is a self-definition, emit error now. + + if T = Parent_Type + or else T = Etype (Parent_Type) + then + Error_Msg_N ("type cannot be used in its own definition", Indic); + end if; + + Set_Ekind (T, Ekind (Parent_Type)); + Set_Etype (T, Any_Type); + Set_Scalar_Range (T, Scalar_Range (Any_Type)); + + if Is_Tagged_Type (T) then + Set_Primitive_Operations (T, New_Elmt_List); + end if; + + return; + end if; + + -- Ada 2005 (AI-251): The case in which the parent of the full-view is + -- an interface is special because the list of interfaces in the full + -- view can be given in any order. For example: + + -- type A is interface; + -- type B is interface and A; + -- type D is new B with private; + -- private + -- type D is new A and B with null record; -- 1 -- + + -- In this case we perform the following transformation of -1-: + + -- type D is new B and A with null record; + + -- If the parent of the full-view covers the parent of the partial-view + -- we have two possible cases: + + -- 1) They have the same parent + -- 2) The parent of the full-view implements some further interfaces + + -- In both cases we do not need to perform the transformation. In the + -- first case the source program is correct and the transformation is + -- not needed; in the second case the source program does not fulfill + -- the no-hidden interfaces rule (AI-396) and the error will be reported + -- later. + + -- This transformation not only simplifies the rest of the analysis of + -- this type declaration but also simplifies the correct generation of + -- the object layout to the expander. + + if In_Private_Part (Current_Scope) + and then Is_Interface (Parent_Type) + then + declare + Iface : Node_Id; + Partial_View : Entity_Id; + Partial_View_Parent : Entity_Id; + New_Iface : Node_Id; + + begin + -- Look for the associated private type declaration + + Partial_View := First_Entity (Current_Scope); + loop + exit when No (Partial_View) + or else (Has_Private_Declaration (Partial_View) + and then Full_View (Partial_View) = T); + + Next_Entity (Partial_View); + end loop; + + -- If the partial view was not found then the source code has + -- errors and the transformation is not needed. + + if Present (Partial_View) then + Partial_View_Parent := Etype (Partial_View); + + -- If the parent of the full-view covers the parent of the + -- partial-view we have nothing else to do. + + if Interface_Present_In_Ancestor + (Parent_Type, Partial_View_Parent) + then + null; + + -- Traverse the list of interfaces of the full-view to look + -- for the parent of the partial-view and perform the tree + -- transformation. + + else + Iface := First (Interface_List (Def)); + while Present (Iface) loop + if Etype (Iface) = Etype (Partial_View) then + Rewrite (Subtype_Indication (Def), + New_Copy (Subtype_Indication + (Parent (Partial_View)))); + + New_Iface := Make_Identifier (Sloc (N), + Chars (Parent_Type)); + Append (New_Iface, Interface_List (Def)); + + -- Analyze the transformed code + + Derived_Type_Declaration (T, N, Is_Completion); + return; + end if; + + Next (Iface); + end loop; + end if; + end if; + end; + end if; + + -- Only composite types other than array types are allowed to have + -- discriminants. + + if Present (Discriminant_Specifications (N)) + and then (Is_Elementary_Type (Parent_Type) + or else Is_Array_Type (Parent_Type)) + and then not Error_Posted (N) + then + Error_Msg_N + ("elementary or array type cannot have discriminants", + Defining_Identifier (First (Discriminant_Specifications (N)))); + Set_Has_Discriminants (T, False); + end if; + + -- In Ada 83, a derived type defined in a package specification cannot + -- be used for further derivation until the end of its visible part. + -- Note that derivation in the private part of the package is allowed. + + if Ada_Version = Ada_83 + and then Is_Derived_Type (Parent_Type) + and then In_Visible_Part (Scope (Parent_Type)) + then + if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then + Error_Msg_N + ("(Ada 83): premature use of type for derivation", Indic); + end if; + end if; + + -- Check for early use of incomplete or private type + + if Ekind (Parent_Type) = E_Void + or else Ekind (Parent_Type) = E_Incomplete_Type + then + Error_Msg_N ("premature derivation of incomplete type", Indic); + return; + + elsif (Is_Incomplete_Or_Private_Type (Parent_Type) + and then not Comes_From_Generic (Parent_Type)) + or else Has_Private_Component (Parent_Type) + then + -- The ancestor type of a formal type can be incomplete, in which + -- case only the operations of the partial view are available in + -- the generic. Subsequent checks may be required when the full + -- view is analyzed, to verify that derivation from a tagged type + -- has an extension. + + if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then + null; + + elsif No (Underlying_Type (Parent_Type)) + or else Has_Private_Component (Parent_Type) + then + Error_Msg_N + ("premature derivation of derived or private type", Indic); + + -- Flag the type itself as being in error, this prevents some + -- nasty problems with subsequent uses of the malformed type. + + Set_Error_Posted (T); + + -- Check that within the immediate scope of an untagged partial + -- view it's illegal to derive from the partial view if the + -- full view is tagged. (7.3(7)) + + -- We verify that the Parent_Type is a partial view by checking + -- that it is not a Full_Type_Declaration (i.e. a private type or + -- private extension declaration), to distinguish a partial view + -- from a derivation from a private type which also appears as + -- E_Private_Type. + + elsif Present (Full_View (Parent_Type)) + and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration + and then not Is_Tagged_Type (Parent_Type) + and then Is_Tagged_Type (Full_View (Parent_Type)) + then + Parent_Scope := Scope (T); + while Present (Parent_Scope) + and then Parent_Scope /= Standard_Standard + loop + if Parent_Scope = Scope (Parent_Type) then + Error_Msg_N + ("premature derivation from type with tagged full view", + Indic); + end if; + + Parent_Scope := Scope (Parent_Scope); + end loop; + end if; + end if; + + -- Check that form of derivation is appropriate + + Taggd := Is_Tagged_Type (Parent_Type); + + -- Perhaps the parent type should be changed to the class-wide type's + -- specific type in this case to prevent cascading errors ??? + + if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then + Error_Msg_N ("parent type must not be a class-wide type", Indic); + return; + end if; + + if Present (Extension) and then not Taggd then + Error_Msg_N + ("type derived from untagged type cannot have extension", Indic); + + elsif No (Extension) and then Taggd then + + -- If this declaration is within a private part (or body) of a + -- generic instantiation then the derivation is allowed (the parent + -- type can only appear tagged in this case if it's a generic actual + -- type, since it would otherwise have been rejected in the analysis + -- of the generic template). + + if not Is_Generic_Actual_Type (Parent_Type) + or else In_Visible_Part (Scope (Parent_Type)) + then + Error_Msg_N + ("type derived from tagged type must have extension", Indic); + end if; + end if; + + Build_Derived_Type (N, Parent_Type, T, Is_Completion); + + -- AI-419: the parent type of an explicitly limited derived type must + -- be a limited type or a limited interface. + + if Limited_Present (Def) then + Set_Is_Limited_Record (T); + + if Is_Interface (T) then + Set_Is_Limited_Interface (T); + end if; + + if not Is_Limited_Type (Parent_Type) + and then + (not Is_Interface (Parent_Type) + or else not Is_Limited_Interface (Parent_Type)) + then + Error_Msg_NE ("parent type& of limited type must be limited", + N, Parent_Type); + end if; + end if; + end Derived_Type_Declaration; + + ---------------------------------- + -- Enumeration_Type_Declaration -- + ---------------------------------- + + procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is + Ev : Uint; + L : Node_Id; + R_Node : Node_Id; + B_Node : Node_Id; + + begin + -- Create identifier node representing lower bound + + B_Node := New_Node (N_Identifier, Sloc (Def)); + L := First (Literals (Def)); + Set_Chars (B_Node, Chars (L)); + Set_Entity (B_Node, L); + Set_Etype (B_Node, T); + Set_Is_Static_Expression (B_Node, True); + + R_Node := New_Node (N_Range, Sloc (Def)); + Set_Low_Bound (R_Node, B_Node); + + Set_Ekind (T, E_Enumeration_Type); + Set_First_Literal (T, L); + Set_Etype (T, T); + Set_Is_Constrained (T); + + Ev := Uint_0; + + -- Loop through literals of enumeration type setting pos and rep values + -- except that if the Ekind is already set, then it means that the + -- literal was already constructed (case of a derived type declaration + -- and we should not disturb the Pos and Rep values. + + while Present (L) loop + if Ekind (L) /= E_Enumeration_Literal then + Set_Ekind (L, E_Enumeration_Literal); + Set_Enumeration_Pos (L, Ev); + Set_Enumeration_Rep (L, Ev); + Set_Is_Known_Valid (L, True); + end if; + + Set_Etype (L, T); + New_Overloaded_Entity (L); + Generate_Definition (L); + Set_Convention (L, Convention_Intrinsic); + + if Nkind (L) = N_Defining_Character_Literal then + Set_Is_Character_Type (T, True); + end if; + + Ev := Ev + 1; + Next (L); + end loop; + + -- Now create a node representing upper bound + + B_Node := New_Node (N_Identifier, Sloc (Def)); + Set_Chars (B_Node, Chars (Last (Literals (Def)))); + Set_Entity (B_Node, Last (Literals (Def))); + Set_Etype (B_Node, T); + Set_Is_Static_Expression (B_Node, True); + + Set_High_Bound (R_Node, B_Node); + Set_Scalar_Range (T, R_Node); + Set_RM_Size (T, UI_From_Int (Minimum_Size (T))); + Set_Enum_Esize (T); + + -- Set Discard_Names if configuration pragma set, or if there is + -- a parameterless pragma in the current declarative region + + if Global_Discard_Names + or else Discard_Names (Scope (T)) + then + Set_Discard_Names (T); + end if; + + -- Process end label if there is one + + if Present (Def) then + Process_End_Label (Def, 'e', T); + end if; + end Enumeration_Type_Declaration; + + --------------------------------- + -- Expand_To_Stored_Constraint -- + --------------------------------- + + function Expand_To_Stored_Constraint + (Typ : Entity_Id; + Constraint : Elist_Id) return Elist_Id + is + Explicitly_Discriminated_Type : Entity_Id; + Expansion : Elist_Id; + Discriminant : Entity_Id; + + function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id; + -- Find the nearest type that actually specifies discriminants + + --------------------------------- + -- Type_With_Explicit_Discrims -- + --------------------------------- + + function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is + Typ : constant E := Base_Type (Id); + + begin + if Ekind (Typ) in Incomplete_Or_Private_Kind then + if Present (Full_View (Typ)) then + return Type_With_Explicit_Discrims (Full_View (Typ)); + end if; + + else + if Has_Discriminants (Typ) then + return Typ; + end if; + end if; + + if Etype (Typ) = Typ then + return Empty; + elsif Has_Discriminants (Typ) then + return Typ; + else + return Type_With_Explicit_Discrims (Etype (Typ)); + end if; + + end Type_With_Explicit_Discrims; + + -- Start of processing for Expand_To_Stored_Constraint + + begin + if No (Constraint) + or else Is_Empty_Elmt_List (Constraint) + then + return No_Elist; + end if; + + Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ); + + if No (Explicitly_Discriminated_Type) then + return No_Elist; + end if; + + Expansion := New_Elmt_List; + + Discriminant := + First_Stored_Discriminant (Explicitly_Discriminated_Type); + while Present (Discriminant) loop + Append_Elmt ( + Get_Discriminant_Value ( + Discriminant, Explicitly_Discriminated_Type, Constraint), + Expansion); + Next_Stored_Discriminant (Discriminant); + end loop; + + return Expansion; + end Expand_To_Stored_Constraint; + + -------------------- + -- Find_Type_Name -- + -------------------- + + function Find_Type_Name (N : Node_Id) return Entity_Id is + Id : constant Entity_Id := Defining_Identifier (N); + Prev : Entity_Id; + New_Id : Entity_Id; + Prev_Par : Node_Id; + + begin + -- Find incomplete declaration, if one was given + + Prev := Current_Entity_In_Scope (Id); + + if Present (Prev) then + + -- Previous declaration exists. Error if not incomplete/private case + -- except if previous declaration is implicit, etc. Enter_Name will + -- emit error if appropriate. + + Prev_Par := Parent (Prev); + + if not Is_Incomplete_Or_Private_Type (Prev) then + Enter_Name (Id); + New_Id := Id; + + elsif Nkind (N) /= N_Full_Type_Declaration + and then Nkind (N) /= N_Task_Type_Declaration + and then Nkind (N) /= N_Protected_Type_Declaration + then + -- Completion must be a full type declarations (RM 7.3(4)) + + Error_Msg_Sloc := Sloc (Prev); + Error_Msg_NE ("invalid completion of }", Id, Prev); + + -- Set scope of Id to avoid cascaded errors. Entity is never + -- examined again, except when saving globals in generics. + + Set_Scope (Id, Current_Scope); + New_Id := Id; + + -- Case of full declaration of incomplete type + + elsif Ekind (Prev) = E_Incomplete_Type then + + -- Indicate that the incomplete declaration has a matching full + -- declaration. The defining occurrence of the incomplete + -- declaration remains the visible one, and the procedure + -- Get_Full_View dereferences it whenever the type is used. + + if Present (Full_View (Prev)) then + Error_Msg_NE ("invalid redeclaration of }", Id, Prev); + end if; + + Set_Full_View (Prev, Id); + Append_Entity (Id, Current_Scope); + Set_Is_Public (Id, Is_Public (Prev)); + Set_Is_Internal (Id); + New_Id := Prev; + + -- Case of full declaration of private type + + else + if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then + if Etype (Prev) /= Prev then + + -- Prev is a private subtype or a derived type, and needs + -- no completion. + + Error_Msg_NE ("invalid redeclaration of }", Id, Prev); + New_Id := Id; + + elsif Ekind (Prev) = E_Private_Type + and then + (Nkind (N) = N_Task_Type_Declaration + or else Nkind (N) = N_Protected_Type_Declaration) + then + Error_Msg_N + ("completion of nonlimited type cannot be limited", N); + + elsif Ekind (Prev) = E_Record_Type_With_Private + and then + (Nkind (N) = N_Task_Type_Declaration + or else Nkind (N) = N_Protected_Type_Declaration) + then + if not Is_Limited_Record (Prev) then + Error_Msg_N + ("completion of nonlimited type cannot be limited", N); + + elsif No (Interface_List (N)) then + Error_Msg_N + ("completion of tagged private type must be tagged", + N); + end if; + end if; + + -- Ada 2005 (AI-251): Private extension declaration of a + -- task type. This case arises with tasks implementing interfaces + + elsif Nkind (N) = N_Task_Type_Declaration + or else Nkind (N) = N_Protected_Type_Declaration + then + null; + + elsif Nkind (N) /= N_Full_Type_Declaration + or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition + then + Error_Msg_N + ("full view of private extension must be an extension", N); + + elsif not (Abstract_Present (Parent (Prev))) + and then Abstract_Present (Type_Definition (N)) + then + Error_Msg_N + ("full view of non-abstract extension cannot be abstract", N); + end if; + + if not In_Private_Part (Current_Scope) then + Error_Msg_N + ("declaration of full view must appear in private part", N); + end if; + + Copy_And_Swap (Prev, Id); + Set_Has_Private_Declaration (Prev); + Set_Has_Private_Declaration (Id); + + -- If no error, propagate freeze_node from private to full view. + -- It may have been generated for an early operational item. + + if Present (Freeze_Node (Id)) + and then Serious_Errors_Detected = 0 + and then No (Full_View (Id)) + then + Set_Freeze_Node (Prev, Freeze_Node (Id)); + Set_Freeze_Node (Id, Empty); + Set_First_Rep_Item (Prev, First_Rep_Item (Id)); + end if; + + Set_Full_View (Id, Prev); + New_Id := Prev; + end if; + + -- Verify that full declaration conforms to incomplete one + + if Is_Incomplete_Or_Private_Type (Prev) + and then Present (Discriminant_Specifications (Prev_Par)) + then + if Present (Discriminant_Specifications (N)) then + if Ekind (Prev) = E_Incomplete_Type then + Check_Discriminant_Conformance (N, Prev, Prev); + else + Check_Discriminant_Conformance (N, Prev, Id); + end if; + + else + Error_Msg_N + ("missing discriminants in full type declaration", N); + + -- To avoid cascaded errors on subsequent use, share the + -- discriminants of the partial view. + + Set_Discriminant_Specifications (N, + Discriminant_Specifications (Prev_Par)); + end if; + end if; + + -- A prior untagged private type can have an associated class-wide + -- type due to use of the class attribute, and in this case also the + -- full type is required to be tagged. + + if Is_Type (Prev) + and then (Is_Tagged_Type (Prev) + or else Present (Class_Wide_Type (Prev))) + and then (Nkind (N) /= N_Task_Type_Declaration + and then Nkind (N) /= N_Protected_Type_Declaration) + then + -- The full declaration is either a tagged record or an + -- extension otherwise this is an error + + if Nkind (Type_Definition (N)) = N_Record_Definition then + if not Tagged_Present (Type_Definition (N)) then + Error_Msg_NE + ("full declaration of } must be tagged", Prev, Id); + Set_Is_Tagged_Type (Id); + Set_Primitive_Operations (Id, New_Elmt_List); + end if; + + elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then + if No (Record_Extension_Part (Type_Definition (N))) then + Error_Msg_NE ( + "full declaration of } must be a record extension", + Prev, Id); + Set_Is_Tagged_Type (Id); + Set_Primitive_Operations (Id, New_Elmt_List); + end if; + + else + Error_Msg_NE + ("full declaration of } must be a tagged type", Prev, Id); + + end if; + end if; + + return New_Id; + + else + -- New type declaration + + Enter_Name (Id); + return Id; + end if; + end Find_Type_Name; + + ------------------------- + -- Find_Type_Of_Object -- + ------------------------- + + function Find_Type_Of_Object + (Obj_Def : Node_Id; + Related_Nod : Node_Id) return Entity_Id + is + Def_Kind : constant Node_Kind := Nkind (Obj_Def); + P : Node_Id := Parent (Obj_Def); + T : Entity_Id; + Nam : Name_Id; + + begin + -- If the parent is a component_definition node we climb to the + -- component_declaration node + + if Nkind (P) = N_Component_Definition then + P := Parent (P); + end if; + + -- Case of an anonymous array subtype + + if Def_Kind = N_Constrained_Array_Definition + or else Def_Kind = N_Unconstrained_Array_Definition + then + T := Empty; + Array_Type_Declaration (T, Obj_Def); + + -- Create an explicit subtype whenever possible + + elsif Nkind (P) /= N_Component_Declaration + and then Def_Kind = N_Subtype_Indication + then + -- Base name of subtype on object name, which will be unique in + -- the current scope. + + -- If this is a duplicate declaration, return base type, to avoid + -- generating duplicate anonymous types. + + if Error_Posted (P) then + Analyze (Subtype_Mark (Obj_Def)); + return Entity (Subtype_Mark (Obj_Def)); + end if; + + Nam := + New_External_Name + (Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T'); + + T := Make_Defining_Identifier (Sloc (P), Nam); + + Insert_Action (Obj_Def, + Make_Subtype_Declaration (Sloc (P), + Defining_Identifier => T, + Subtype_Indication => Relocate_Node (Obj_Def))); + + -- This subtype may need freezing, and this will not be done + -- automatically if the object declaration is not in declarative + -- part. Since this is an object declaration, the type cannot always + -- be frozen here. Deferred constants do not freeze their type + -- (which often enough will be private). + + if Nkind (P) = N_Object_Declaration + and then Constant_Present (P) + and then No (Expression (P)) + then + null; + else + Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P))); + end if; + + -- Ada 2005 AI-406: the object definition in an object declaration + -- can be an access definition. + + elsif Def_Kind = N_Access_Definition then + T := Access_Definition (Related_Nod, Obj_Def); + Set_Is_Local_Anonymous_Access (T); + + -- comment here, what cases ??? + + else + T := Process_Subtype (Obj_Def, Related_Nod); + end if; + + return T; + end Find_Type_Of_Object; + + -------------------------------- + -- Find_Type_Of_Subtype_Indic -- + -------------------------------- + + function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is + Typ : Entity_Id; + + begin + -- Case of subtype mark with a constraint + + if Nkind (S) = N_Subtype_Indication then + Find_Type (Subtype_Mark (S)); + Typ := Entity (Subtype_Mark (S)); + + if not + Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S))) + then + Error_Msg_N + ("incorrect constraint for this kind of type", Constraint (S)); + Rewrite (S, New_Copy_Tree (Subtype_Mark (S))); + end if; + + -- Otherwise we have a subtype mark without a constraint + + elsif Error_Posted (S) then + Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S))); + return Any_Type; + + else + Find_Type (S); + Typ := Entity (S); + end if; + + if Typ = Standard_Wide_Character + or else Typ = Standard_Wide_Wide_Character + or else Typ = Standard_Wide_String + or else Typ = Standard_Wide_Wide_String + then + Check_Restriction (No_Wide_Characters, S); + end if; + + return Typ; + end Find_Type_Of_Subtype_Indic; + + ------------------------------------- + -- Floating_Point_Type_Declaration -- + ------------------------------------- + + procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is + Digs : constant Node_Id := Digits_Expression (Def); + Digs_Val : Uint; + Base_Typ : Entity_Id; + Implicit_Base : Entity_Id; + Bound : Node_Id; + + function Can_Derive_From (E : Entity_Id) return Boolean; + -- Find if given digits value allows derivation from specified type + + --------------------- + -- Can_Derive_From -- + --------------------- + + function Can_Derive_From (E : Entity_Id) return Boolean is + Spec : constant Entity_Id := Real_Range_Specification (Def); + + begin + if Digs_Val > Digits_Value (E) then + return False; + end if; + + if Present (Spec) then + if Expr_Value_R (Type_Low_Bound (E)) > + Expr_Value_R (Low_Bound (Spec)) + then + return False; + end if; + + if Expr_Value_R (Type_High_Bound (E)) < + Expr_Value_R (High_Bound (Spec)) + then + return False; + end if; + end if; + + return True; + end Can_Derive_From; + + -- Start of processing for Floating_Point_Type_Declaration + + begin + Check_Restriction (No_Floating_Point, Def); + + -- Create an implicit base type + + Implicit_Base := + Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B'); + + -- Analyze and verify digits value + + Analyze_And_Resolve (Digs, Any_Integer); + Check_Digits_Expression (Digs); + Digs_Val := Expr_Value (Digs); + + -- Process possible range spec and find correct type to derive from + + Process_Real_Range_Specification (Def); + + if Can_Derive_From (Standard_Short_Float) then + Base_Typ := Standard_Short_Float; + elsif Can_Derive_From (Standard_Float) then + Base_Typ := Standard_Float; + elsif Can_Derive_From (Standard_Long_Float) then + Base_Typ := Standard_Long_Float; + elsif Can_Derive_From (Standard_Long_Long_Float) then + Base_Typ := Standard_Long_Long_Float; + + -- If we can't derive from any existing type, use long_long_float + -- and give appropriate message explaining the problem. + + else + Base_Typ := Standard_Long_Long_Float; + + if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then + Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float); + Error_Msg_N ("digits value out of range, maximum is ^", Digs); + + else + Error_Msg_N + ("range too large for any predefined type", + Real_Range_Specification (Def)); + end if; + end if; + + -- If there are bounds given in the declaration use them as the bounds + -- of the type, otherwise use the bounds of the predefined base type + -- that was chosen based on the Digits value. + + if Present (Real_Range_Specification (Def)) then + Set_Scalar_Range (T, Real_Range_Specification (Def)); + Set_Is_Constrained (T); + + -- The bounds of this range must be converted to machine numbers + -- in accordance with RM 4.9(38). + + Bound := Type_Low_Bound (T); + + if Nkind (Bound) = N_Real_Literal then + Set_Realval + (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound)); + Set_Is_Machine_Number (Bound); + end if; + + Bound := Type_High_Bound (T); + + if Nkind (Bound) = N_Real_Literal then + Set_Realval + (Bound, Machine (Base_Typ, Realval (Bound), Round, Bound)); + Set_Is_Machine_Number (Bound); + end if; + + else + Set_Scalar_Range (T, Scalar_Range (Base_Typ)); + end if; + + -- Complete definition of implicit base and declared first subtype + + Set_Etype (Implicit_Base, Base_Typ); + + Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ)); + Set_Size_Info (Implicit_Base, (Base_Typ)); + Set_RM_Size (Implicit_Base, RM_Size (Base_Typ)); + Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ)); + Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ)); + Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ)); + + Set_Ekind (T, E_Floating_Point_Subtype); + Set_Etype (T, Implicit_Base); + + Set_Size_Info (T, (Implicit_Base)); + Set_RM_Size (T, RM_Size (Implicit_Base)); + Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base)); + Set_Digits_Value (T, Digs_Val); + end Floating_Point_Type_Declaration; + + ---------------------------- + -- Get_Discriminant_Value -- + ---------------------------- + + -- This is the situation: + + -- There is a non-derived type + + -- type T0 (Dx, Dy, Dz...) + + -- There are zero or more levels of derivation, with each derivation + -- either purely inheriting the discriminants, or defining its own. + + -- type Ti is new Ti-1 + -- or + -- type Ti (Dw) is new Ti-1(Dw, 1, X+Y) + -- or + -- subtype Ti is ... + + -- The subtype issue is avoided by the use of Original_Record_Component, + -- and the fact that derived subtypes also derive the constraints. + + -- This chain leads back from + + -- Typ_For_Constraint + + -- Typ_For_Constraint has discriminants, and the value for each + -- discriminant is given by its corresponding Elmt of Constraints. + + -- Discriminant is some discriminant in this hierarchy + + -- We need to return its value + + -- We do this by recursively searching each level, and looking for + -- Discriminant. Once we get to the bottom, we start backing up + -- returning the value for it which may in turn be a discriminant + -- further up, so on the backup we continue the substitution. + + function Get_Discriminant_Value + (Discriminant : Entity_Id; + Typ_For_Constraint : Entity_Id; + Constraint : Elist_Id) return Node_Id + is + function Search_Derivation_Levels + (Ti : Entity_Id; + Discrim_Values : Elist_Id; + Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id; + -- This is the routine that performs the recursive search of levels + -- as described above. + + ------------------------------ + -- Search_Derivation_Levels -- + ------------------------------ + + function Search_Derivation_Levels + (Ti : Entity_Id; + Discrim_Values : Elist_Id; + Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id + is + Assoc : Elmt_Id; + Disc : Entity_Id; + Result : Node_Or_Entity_Id; + Result_Entity : Node_Id; + + begin + -- If inappropriate type, return Error, this happens only in + -- cascaded error situations, and we want to avoid a blow up. + + if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then + return Error; + end if; + + -- Look deeper if possible. Use Stored_Constraints only for + -- untagged types. For tagged types use the given constraint. + -- This asymmetry needs explanation??? + + if not Stored_Discrim_Values + and then Present (Stored_Constraint (Ti)) + and then not Is_Tagged_Type (Ti) + then + Result := + Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True); + else + declare + Td : constant Entity_Id := Etype (Ti); + + begin + if Td = Ti then + Result := Discriminant; + + else + if Present (Stored_Constraint (Ti)) then + Result := + Search_Derivation_Levels + (Td, Stored_Constraint (Ti), True); + else + Result := + Search_Derivation_Levels + (Td, Discrim_Values, Stored_Discrim_Values); + end if; + end if; + end; + end if; + + -- Extra underlying places to search, if not found above. For + -- concurrent types, the relevant discriminant appears in the + -- corresponding record. For a type derived from a private type + -- without discriminant, the full view inherits the discriminants + -- of the full view of the parent. + + if Result = Discriminant then + if Is_Concurrent_Type (Ti) + and then Present (Corresponding_Record_Type (Ti)) + then + Result := + Search_Derivation_Levels ( + Corresponding_Record_Type (Ti), + Discrim_Values, + Stored_Discrim_Values); + + elsif Is_Private_Type (Ti) + and then not Has_Discriminants (Ti) + and then Present (Full_View (Ti)) + and then Etype (Full_View (Ti)) /= Ti + then + Result := + Search_Derivation_Levels ( + Full_View (Ti), + Discrim_Values, + Stored_Discrim_Values); + end if; + end if; + + -- If Result is not a (reference to a) discriminant, return it, + -- otherwise set Result_Entity to the discriminant. + + if Nkind (Result) = N_Defining_Identifier then + pragma Assert (Result = Discriminant); + Result_Entity := Result; + + else + if not Denotes_Discriminant (Result) then + return Result; + end if; + + Result_Entity := Entity (Result); + end if; + + -- See if this level of derivation actually has discriminants + -- because tagged derivations can add them, hence the lower + -- levels need not have any. + + if not Has_Discriminants (Ti) then + return Result; + end if; + + -- Scan Ti's discriminants for Result_Entity, + -- and return its corresponding value, if any. + + Result_Entity := Original_Record_Component (Result_Entity); + + Assoc := First_Elmt (Discrim_Values); + + if Stored_Discrim_Values then + Disc := First_Stored_Discriminant (Ti); + else + Disc := First_Discriminant (Ti); + end if; + + while Present (Disc) loop + pragma Assert (Present (Assoc)); + + if Original_Record_Component (Disc) = Result_Entity then + return Node (Assoc); + end if; + + Next_Elmt (Assoc); + + if Stored_Discrim_Values then + Next_Stored_Discriminant (Disc); + else + Next_Discriminant (Disc); + end if; + end loop; + + -- Could not find it + -- + return Result; + end Search_Derivation_Levels; + + Result : Node_Or_Entity_Id; + + -- Start of processing for Get_Discriminant_Value + + begin + -- ??? This routine is a gigantic mess and will be deleted. For the + -- time being just test for the trivial case before calling recurse. + + if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then + declare + D : Entity_Id; + E : Elmt_Id; + + begin + D := First_Discriminant (Typ_For_Constraint); + E := First_Elmt (Constraint); + while Present (D) loop + if Chars (D) = Chars (Discriminant) then + return Node (E); + end if; + + Next_Discriminant (D); + Next_Elmt (E); + end loop; + end; + end if; + + Result := Search_Derivation_Levels + (Typ_For_Constraint, Constraint, False); + + -- ??? hack to disappear when this routine is gone + + if Nkind (Result) = N_Defining_Identifier then + declare + D : Entity_Id; + E : Elmt_Id; + + begin + D := First_Discriminant (Typ_For_Constraint); + E := First_Elmt (Constraint); + while Present (D) loop + if Corresponding_Discriminant (D) = Discriminant then + return Node (E); + end if; + + Next_Discriminant (D); + Next_Elmt (E); + end loop; + end; + end if; + + pragma Assert (Nkind (Result) /= N_Defining_Identifier); + return Result; + end Get_Discriminant_Value; + + -------------------------- + -- Has_Range_Constraint -- + -------------------------- + + function Has_Range_Constraint (N : Node_Id) return Boolean is + C : constant Node_Id := Constraint (N); + + begin + if Nkind (C) = N_Range_Constraint then + return True; + + elsif Nkind (C) = N_Digits_Constraint then + return + Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N))) + or else + Present (Range_Constraint (C)); + + elsif Nkind (C) = N_Delta_Constraint then + return Present (Range_Constraint (C)); + + else + return False; + end if; + end Has_Range_Constraint; + + ------------------------ + -- Inherit_Components -- + ------------------------ + + function Inherit_Components + (N : Node_Id; + Parent_Base : Entity_Id; + Derived_Base : Entity_Id; + Is_Tagged : Boolean; + Inherit_Discr : Boolean; + Discs : Elist_Id) return Elist_Id + is + Assoc_List : constant Elist_Id := New_Elmt_List; + + procedure Inherit_Component + (Old_C : Entity_Id; + Plain_Discrim : Boolean := False; + Stored_Discrim : Boolean := False); + -- Inherits component Old_C from Parent_Base to the Derived_Base. If + -- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is + -- True, Old_C is a stored discriminant. If they are both false then + -- Old_C is a regular component. + + ----------------------- + -- Inherit_Component -- + ----------------------- + + procedure Inherit_Component + (Old_C : Entity_Id; + Plain_Discrim : Boolean := False; + Stored_Discrim : Boolean := False) + is + New_C : constant Entity_Id := New_Copy (Old_C); + + Discrim : Entity_Id; + Corr_Discrim : Entity_Id; + + begin + pragma Assert (not Is_Tagged or else not Stored_Discrim); + + Set_Parent (New_C, Parent (Old_C)); + + -- Regular discriminants and components must be inserted + -- in the scope of the Derived_Base. Do it here. + + if not Stored_Discrim then + Enter_Name (New_C); + end if; + + -- For tagged types the Original_Record_Component must point to + -- whatever this field was pointing to in the parent type. This has + -- already been achieved by the call to New_Copy above. + + if not Is_Tagged then + Set_Original_Record_Component (New_C, New_C); + end if; + + -- If we have inherited a component then see if its Etype contains + -- references to Parent_Base discriminants. In this case, replace + -- these references with the constraints given in Discs. We do not + -- do this for the partial view of private types because this is + -- not needed (only the components of the full view will be used + -- for code generation) and cause problem. We also avoid this + -- transformation in some error situations. + + if Ekind (New_C) = E_Component then + if (Is_Private_Type (Derived_Base) + and then not Is_Generic_Type (Derived_Base)) + or else (Is_Empty_Elmt_List (Discs) + and then not Expander_Active) + then + Set_Etype (New_C, Etype (Old_C)); + else + Set_Etype + (New_C, + Constrain_Component_Type + (Old_C, Derived_Base, N, Parent_Base, Discs)); + end if; + end if; + + -- In derived tagged types it is illegal to reference a non + -- discriminant component in the parent type. To catch this, mark + -- these components with an Ekind of E_Void. This will be reset in + -- Record_Type_Definition after processing the record extension of + -- the derived type. + + if Is_Tagged and then Ekind (New_C) = E_Component then + Set_Ekind (New_C, E_Void); + end if; + + if Plain_Discrim then + Set_Corresponding_Discriminant (New_C, Old_C); + Build_Discriminal (New_C); + + -- If we are explicitly inheriting a stored discriminant it will be + -- completely hidden. + + elsif Stored_Discrim then + Set_Corresponding_Discriminant (New_C, Empty); + Set_Discriminal (New_C, Empty); + Set_Is_Completely_Hidden (New_C); + + -- Set the Original_Record_Component of each discriminant in the + -- derived base to point to the corresponding stored that we just + -- created. + + Discrim := First_Discriminant (Derived_Base); + while Present (Discrim) loop + Corr_Discrim := Corresponding_Discriminant (Discrim); + + -- Corr_Discrim could be missing in an error situation + + if Present (Corr_Discrim) + and then Original_Record_Component (Corr_Discrim) = Old_C + then + Set_Original_Record_Component (Discrim, New_C); + end if; + + Next_Discriminant (Discrim); + end loop; + + Append_Entity (New_C, Derived_Base); + end if; + + if not Is_Tagged then + Append_Elmt (Old_C, Assoc_List); + Append_Elmt (New_C, Assoc_List); + end if; + end Inherit_Component; + + -- Variables local to Inherit_Component + + Loc : constant Source_Ptr := Sloc (N); + + Parent_Discrim : Entity_Id; + Stored_Discrim : Entity_Id; + D : Entity_Id; + Component : Entity_Id; + + -- Start of processing for Inherit_Components + + begin + if not Is_Tagged then + Append_Elmt (Parent_Base, Assoc_List); + Append_Elmt (Derived_Base, Assoc_List); + end if; + + -- Inherit parent discriminants if needed + + if Inherit_Discr then + Parent_Discrim := First_Discriminant (Parent_Base); + while Present (Parent_Discrim) loop + Inherit_Component (Parent_Discrim, Plain_Discrim => True); + Next_Discriminant (Parent_Discrim); + end loop; + end if; + + -- Create explicit stored discrims for untagged types when necessary + + if not Has_Unknown_Discriminants (Derived_Base) + and then Has_Discriminants (Parent_Base) + and then not Is_Tagged + and then + (not Inherit_Discr + or else First_Discriminant (Parent_Base) /= + First_Stored_Discriminant (Parent_Base)) + then + Stored_Discrim := First_Stored_Discriminant (Parent_Base); + while Present (Stored_Discrim) loop + Inherit_Component (Stored_Discrim, Stored_Discrim => True); + Next_Stored_Discriminant (Stored_Discrim); + end loop; + end if; + + -- See if we can apply the second transformation for derived types, as + -- explained in point 6. in the comments above Build_Derived_Record_Type + -- This is achieved by appending Derived_Base discriminants into Discs, + -- which has the side effect of returning a non empty Discs list to the + -- caller of Inherit_Components, which is what we want. This must be + -- done for private derived types if there are explicit stored + -- discriminants, to ensure that we can retrieve the values of the + -- constraints provided in the ancestors. + + if Inherit_Discr + and then Is_Empty_Elmt_List (Discs) + and then Present (First_Discriminant (Derived_Base)) + and then + (not Is_Private_Type (Derived_Base) + or else Is_Completely_Hidden + (First_Stored_Discriminant (Derived_Base)) + or else Is_Generic_Type (Derived_Base)) + then + D := First_Discriminant (Derived_Base); + while Present (D) loop + Append_Elmt (New_Reference_To (D, Loc), Discs); + Next_Discriminant (D); + end loop; + end if; + + -- Finally, inherit non-discriminant components unless they are not + -- visible because defined or inherited from the full view of the + -- parent. Don't inherit the _parent field of the parent type. + + Component := First_Entity (Parent_Base); + while Present (Component) loop + + -- Ada 2005 (AI-251): Do not inherit tags corresponding with the + -- interfaces of the parent + + if Ekind (Component) = E_Component + and then Is_Tag (Component) + and then RTE_Available (RE_Interface_Tag) + and then Etype (Component) = RTE (RE_Interface_Tag) + then + null; + + elsif Ekind (Component) /= E_Component + or else Chars (Component) = Name_uParent + then + null; + + -- If the derived type is within the parent type's declarative + -- region, then the components can still be inherited even though + -- they aren't visible at this point. This can occur for cases + -- such as within public child units where the components must + -- become visible upon entering the child unit's private part. + + elsif not Is_Visible_Component (Component) + and then not In_Open_Scopes (Scope (Parent_Base)) + then + null; + + elsif Ekind (Derived_Base) = E_Private_Type + or else Ekind (Derived_Base) = E_Limited_Private_Type + then + null; + + else + Inherit_Component (Component); + end if; + + Next_Entity (Component); + end loop; + + -- For tagged derived types, inherited discriminants cannot be used in + -- component declarations of the record extension part. To achieve this + -- we mark the inherited discriminants as not visible. + + if Is_Tagged and then Inherit_Discr then + D := First_Discriminant (Derived_Base); + while Present (D) loop + Set_Is_Immediately_Visible (D, False); + Next_Discriminant (D); + end loop; + end if; + + return Assoc_List; + end Inherit_Components; + + ----------------------- + -- Is_Null_Extension -- + ----------------------- + + function Is_Null_Extension (T : Entity_Id) return Boolean is + Full_Type_Decl : constant Node_Id := Parent (T); + Full_Type_Defn : constant Node_Id := Type_Definition (Full_Type_Decl); + Comp_List : Node_Id; + First_Comp : Node_Id; + + begin + if not Is_Tagged_Type (T) + or else Nkind (Full_Type_Defn) /= N_Derived_Type_Definition + then + return False; + end if; + + Comp_List := Component_List (Record_Extension_Part (Full_Type_Defn)); + + if Present (Discriminant_Specifications (Full_Type_Decl)) then + return False; + + elsif Present (Comp_List) + and then Is_Non_Empty_List (Component_Items (Comp_List)) + then + First_Comp := First (Component_Items (Comp_List)); + + return Chars (Defining_Identifier (First_Comp)) = Name_uParent + and then No (Next (First_Comp)); + + else + return True; + end if; + end Is_Null_Extension; + + ------------------------------ + -- Is_Valid_Constraint_Kind -- + ------------------------------ + + function Is_Valid_Constraint_Kind + (T_Kind : Type_Kind; + Constraint_Kind : Node_Kind) return Boolean + is + begin + case T_Kind is + when Enumeration_Kind | + Integer_Kind => + return Constraint_Kind = N_Range_Constraint; + + when Decimal_Fixed_Point_Kind => + return + Constraint_Kind = N_Digits_Constraint + or else + Constraint_Kind = N_Range_Constraint; + + when Ordinary_Fixed_Point_Kind => + return + Constraint_Kind = N_Delta_Constraint + or else + Constraint_Kind = N_Range_Constraint; + + when Float_Kind => + return + Constraint_Kind = N_Digits_Constraint + or else + Constraint_Kind = N_Range_Constraint; + + when Access_Kind | + Array_Kind | + E_Record_Type | + E_Record_Subtype | + Class_Wide_Kind | + E_Incomplete_Type | + Private_Kind | + Concurrent_Kind => + return Constraint_Kind = N_Index_Or_Discriminant_Constraint; + + when others => + return True; -- Error will be detected later + end case; + end Is_Valid_Constraint_Kind; + + -------------------------- + -- Is_Visible_Component -- + -------------------------- + + function Is_Visible_Component (C : Entity_Id) return Boolean is + Original_Comp : Entity_Id := Empty; + Original_Scope : Entity_Id; + Type_Scope : Entity_Id; + + function Is_Local_Type (Typ : Entity_Id) return Boolean; + -- Check whether parent type of inherited component is declared locally, + -- possibly within a nested package or instance. The current scope is + -- the derived record itself. + + ------------------- + -- Is_Local_Type -- + ------------------- + + function Is_Local_Type (Typ : Entity_Id) return Boolean is + Scop : Entity_Id; + + begin + Scop := Scope (Typ); + while Present (Scop) + and then Scop /= Standard_Standard + loop + if Scop = Scope (Current_Scope) then + return True; + end if; + + Scop := Scope (Scop); + end loop; + + return False; + end Is_Local_Type; + + -- Start of processing for Is_Visible_Component + + begin + if Ekind (C) = E_Component + or else Ekind (C) = E_Discriminant + then + Original_Comp := Original_Record_Component (C); + end if; + + if No (Original_Comp) then + + -- Premature usage, or previous error + + return False; + + else + Original_Scope := Scope (Original_Comp); + Type_Scope := Scope (Base_Type (Scope (C))); + end if; + + -- This test only concerns tagged types + + if not Is_Tagged_Type (Original_Scope) then + return True; + + -- If it is _Parent or _Tag, there is no visibility issue + + elsif not Comes_From_Source (Original_Comp) then + return True; + + -- If we are in the body of an instantiation, the component is visible + -- even when the parent type (possibly defined in an enclosing unit or + -- in a parent unit) might not. + + elsif In_Instance_Body then + return True; + + -- Discriminants are always visible + + elsif Ekind (Original_Comp) = E_Discriminant + and then not Has_Unknown_Discriminants (Original_Scope) + then + return True; + + -- If the component has been declared in an ancestor which is currently + -- a private type, then it is not visible. The same applies if the + -- component's containing type is not in an open scope and the original + -- component's enclosing type is a visible full type of a private type + -- (which can occur in cases where an attempt is being made to reference + -- a component in a sibling package that is inherited from a visible + -- component of a type in an ancestor package; the component in the + -- sibling package should not be visible even though the component it + -- inherited from is visible). This does not apply however in the case + -- where the scope of the type is a private child unit, or when the + -- parent comes from a local package in which the ancestor is currently + -- visible. The latter suppression of visibility is needed for cases + -- that are tested in B730006. + + elsif Is_Private_Type (Original_Scope) + or else + (not Is_Private_Descendant (Type_Scope) + and then not In_Open_Scopes (Type_Scope) + and then Has_Private_Declaration (Original_Scope)) + then + -- If the type derives from an entity in a formal package, there + -- are no additional visible components. + + if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) = + N_Formal_Package_Declaration + then + return False; + + -- if we are not in the private part of the current package, there + -- are no additional visible components. + + elsif Ekind (Scope (Current_Scope)) = E_Package + and then not In_Private_Part (Scope (Current_Scope)) + then + return False; + else + return + Is_Child_Unit (Cunit_Entity (Current_Sem_Unit)) + and then Is_Local_Type (Type_Scope); + end if; + + -- There is another weird way in which a component may be invisible + -- when the private and the full view are not derived from the same + -- ancestor. Here is an example : + + -- type A1 is tagged record F1 : integer; end record; + -- type A2 is new A1 with record F2 : integer; end record; + -- type T is new A1 with private; + -- private + -- type T is new A2 with null record; + + -- In this case, the full view of T inherits F1 and F2 but the private + -- view inherits only F1 + + else + declare + Ancestor : Entity_Id := Scope (C); + + begin + loop + if Ancestor = Original_Scope then + return True; + elsif Ancestor = Etype (Ancestor) then + return False; + end if; + + Ancestor := Etype (Ancestor); + end loop; + + return True; + end; + end if; + end Is_Visible_Component; + + -------------------------- + -- Make_Class_Wide_Type -- + -------------------------- + + procedure Make_Class_Wide_Type (T : Entity_Id) is + CW_Type : Entity_Id; + CW_Name : Name_Id; + Next_E : Entity_Id; + + begin + -- The class wide type can have been defined by the partial view in + -- which case everything is already done + + if Present (Class_Wide_Type (T)) then + return; + end if; + + CW_Type := + New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T'); + + -- Inherit root type characteristics + + CW_Name := Chars (CW_Type); + Next_E := Next_Entity (CW_Type); + Copy_Node (T, CW_Type); + Set_Comes_From_Source (CW_Type, False); + Set_Chars (CW_Type, CW_Name); + Set_Parent (CW_Type, Parent (T)); + Set_Next_Entity (CW_Type, Next_E); + Set_Has_Delayed_Freeze (CW_Type); + + -- Customize the class-wide type: It has no prim. op., it cannot be + -- abstract and its Etype points back to the specific root type. + + Set_Ekind (CW_Type, E_Class_Wide_Type); + Set_Is_Tagged_Type (CW_Type, True); + Set_Primitive_Operations (CW_Type, New_Elmt_List); + Set_Is_Abstract (CW_Type, False); + Set_Is_Constrained (CW_Type, False); + Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T)); + Init_Size_Align (CW_Type); + + if Ekind (T) = E_Class_Wide_Subtype then + Set_Etype (CW_Type, Etype (Base_Type (T))); + else + Set_Etype (CW_Type, T); + end if; + + -- If this is the class_wide type of a constrained subtype, it does + -- not have discriminants. + + Set_Has_Discriminants (CW_Type, + Has_Discriminants (T) and then not Is_Constrained (T)); + + Set_Has_Unknown_Discriminants (CW_Type, True); + Set_Class_Wide_Type (T, CW_Type); + Set_Equivalent_Type (CW_Type, Empty); + + -- The class-wide type of a class-wide type is itself (RM 3.9(14)) + + Set_Class_Wide_Type (CW_Type, CW_Type); + end Make_Class_Wide_Type; + + ---------------- + -- Make_Index -- + ---------------- + + procedure Make_Index + (I : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id := Empty; + Suffix_Index : Nat := 1) + is + R : Node_Id; + T : Entity_Id; + Def_Id : Entity_Id := Empty; + Found : Boolean := False; + + begin + -- For a discrete range used in a constrained array definition and + -- defined by a range, an implicit conversion to the predefined type + -- INTEGER is assumed if each bound is either a numeric literal, a named + -- number, or an attribute, and the type of both bounds (prior to the + -- implicit conversion) is the type universal_integer. Otherwise, both + -- bounds must be of the same discrete type, other than universal + -- integer; this type must be determinable independently of the + -- context, but using the fact that the type must be discrete and that + -- both bounds must have the same type. + + -- Character literals also have a universal type in the absence of + -- of additional context, and are resolved to Standard_Character. + + if Nkind (I) = N_Range then + + -- The index is given by a range constraint. The bounds are known + -- to be of a consistent type. + + if not Is_Overloaded (I) then + T := Etype (I); + + -- If the bounds are universal, choose the specific predefined + -- type. + + if T = Universal_Integer then + T := Standard_Integer; + + elsif T = Any_Character then + + if Ada_Version >= Ada_95 then + Error_Msg_N + ("ambiguous character literals (could be Wide_Character)", + I); + end if; + + T := Standard_Character; + end if; + + else + T := Any_Type; + + declare + Ind : Interp_Index; + It : Interp; + + begin + Get_First_Interp (I, Ind, It); + while Present (It.Typ) loop + if Is_Discrete_Type (It.Typ) then + + if Found + and then not Covers (It.Typ, T) + and then not Covers (T, It.Typ) + then + Error_Msg_N ("ambiguous bounds in discrete range", I); + exit; + else + T := It.Typ; + Found := True; + end if; + end if; + + Get_Next_Interp (Ind, It); + end loop; + + if T = Any_Type then + Error_Msg_N ("discrete type required for range", I); + Set_Etype (I, Any_Type); + return; + + elsif T = Universal_Integer then + T := Standard_Integer; + end if; + end; + end if; + + if not Is_Discrete_Type (T) then + Error_Msg_N ("discrete type required for range", I); + Set_Etype (I, Any_Type); + return; + end if; + + if Nkind (Low_Bound (I)) = N_Attribute_Reference + and then Attribute_Name (Low_Bound (I)) = Name_First + and then Is_Entity_Name (Prefix (Low_Bound (I))) + and then Is_Type (Entity (Prefix (Low_Bound (I)))) + and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I)))) + then + -- The type of the index will be the type of the prefix, as long + -- as the upper bound is 'Last of the same type. + + Def_Id := Entity (Prefix (Low_Bound (I))); + + if Nkind (High_Bound (I)) /= N_Attribute_Reference + or else Attribute_Name (High_Bound (I)) /= Name_Last + or else not Is_Entity_Name (Prefix (High_Bound (I))) + or else Entity (Prefix (High_Bound (I))) /= Def_Id + then + Def_Id := Empty; + end if; + end if; + + R := I; + Process_Range_Expr_In_Decl (R, T); + + elsif Nkind (I) = N_Subtype_Indication then + + -- The index is given by a subtype with a range constraint + + T := Base_Type (Entity (Subtype_Mark (I))); + + if not Is_Discrete_Type (T) then + Error_Msg_N ("discrete type required for range", I); + Set_Etype (I, Any_Type); + return; + end if; + + R := Range_Expression (Constraint (I)); + + Resolve (R, T); + Process_Range_Expr_In_Decl (R, Entity (Subtype_Mark (I))); + + elsif Nkind (I) = N_Attribute_Reference then + + -- The parser guarantees that the attribute is a RANGE attribute + + -- If the node denotes the range of a type mark, that is also the + -- resulting type, and we do no need to create an Itype for it. + + if Is_Entity_Name (Prefix (I)) + and then Comes_From_Source (I) + and then Is_Type (Entity (Prefix (I))) + and then Is_Discrete_Type (Entity (Prefix (I))) + then + Def_Id := Entity (Prefix (I)); + end if; + + Analyze_And_Resolve (I); + T := Etype (I); + R := I; + + -- If none of the above, must be a subtype. We convert this to a + -- range attribute reference because in the case of declared first + -- named subtypes, the types in the range reference can be different + -- from the type of the entity. A range attribute normalizes the + -- reference and obtains the correct types for the bounds. + + -- This transformation is in the nature of an expansion, is only + -- done if expansion is active. In particular, it is not done on + -- formal generic types, because we need to retain the name of the + -- original index for instantiation purposes. + + else + if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then + Error_Msg_N ("invalid subtype mark in discrete range ", I); + Set_Etype (I, Any_Integer); + return; + + else + -- The type mark may be that of an incomplete type. It is only + -- now that we can get the full view, previous analysis does + -- not look specifically for a type mark. + + Set_Entity (I, Get_Full_View (Entity (I))); + Set_Etype (I, Entity (I)); + Def_Id := Entity (I); + + if not Is_Discrete_Type (Def_Id) then + Error_Msg_N ("discrete type required for index", I); + Set_Etype (I, Any_Type); + return; + end if; + end if; + + if Expander_Active then + Rewrite (I, + Make_Attribute_Reference (Sloc (I), + Attribute_Name => Name_Range, + Prefix => Relocate_Node (I))); + + -- The original was a subtype mark that does not freeze. This + -- means that the rewritten version must not freeze either. + + Set_Must_Not_Freeze (I); + Set_Must_Not_Freeze (Prefix (I)); + + -- Is order critical??? if so, document why, if not + -- use Analyze_And_Resolve + + Analyze (I); + T := Etype (I); + Resolve (I); + R := I; + + -- If expander is inactive, type is legal, nothing else to construct + + else + return; + end if; + end if; + + if not Is_Discrete_Type (T) then + Error_Msg_N ("discrete type required for range", I); + Set_Etype (I, Any_Type); + return; + + elsif T = Any_Type then + Set_Etype (I, Any_Type); + return; + end if; + + -- We will now create the appropriate Itype to describe the range, but + -- first a check. If we originally had a subtype, then we just label + -- the range with this subtype. Not only is there no need to construct + -- a new subtype, but it is wrong to do so for two reasons: + + -- 1. A legality concern, if we have a subtype, it must not freeze, + -- and the Itype would cause freezing incorrectly + + -- 2. An efficiency concern, if we created an Itype, it would not be + -- recognized as the same type for the purposes of eliminating + -- checks in some circumstances. + + -- We signal this case by setting the subtype entity in Def_Id + + if No (Def_Id) then + Def_Id := + Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index); + Set_Etype (Def_Id, Base_Type (T)); + + if Is_Signed_Integer_Type (T) then + Set_Ekind (Def_Id, E_Signed_Integer_Subtype); + + elsif Is_Modular_Integer_Type (T) then + Set_Ekind (Def_Id, E_Modular_Integer_Subtype); + + else + Set_Ekind (Def_Id, E_Enumeration_Subtype); + Set_Is_Character_Type (Def_Id, Is_Character_Type (T)); + Set_First_Literal (Def_Id, First_Literal (T)); + end if; + + Set_Size_Info (Def_Id, (T)); + Set_RM_Size (Def_Id, RM_Size (T)); + Set_First_Rep_Item (Def_Id, First_Rep_Item (T)); + + Set_Scalar_Range (Def_Id, R); + Conditional_Delay (Def_Id, T); + + -- In the subtype indication case, if the immediate parent of the + -- new subtype is non-static, then the subtype we create is non- + -- static, even if its bounds are static. + + if Nkind (I) = N_Subtype_Indication + and then not Is_Static_Subtype (Entity (Subtype_Mark (I))) + then + Set_Is_Non_Static_Subtype (Def_Id); + end if; + end if; + + -- Final step is to label the index with this constructed type + + Set_Etype (I, Def_Id); + end Make_Index; + + ------------------------------ + -- Modular_Type_Declaration -- + ------------------------------ + + procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is + Mod_Expr : constant Node_Id := Expression (Def); + M_Val : Uint; + + procedure Set_Modular_Size (Bits : Int); + -- Sets RM_Size to Bits, and Esize to normal word size above this + + ---------------------- + -- Set_Modular_Size -- + ---------------------- + + procedure Set_Modular_Size (Bits : Int) is + begin + Set_RM_Size (T, UI_From_Int (Bits)); + + if Bits <= 8 then + Init_Esize (T, 8); + + elsif Bits <= 16 then + Init_Esize (T, 16); + + elsif Bits <= 32 then + Init_Esize (T, 32); + + else + Init_Esize (T, System_Max_Binary_Modulus_Power); + end if; + end Set_Modular_Size; + + -- Start of processing for Modular_Type_Declaration + + begin + Analyze_And_Resolve (Mod_Expr, Any_Integer); + Set_Etype (T, T); + Set_Ekind (T, E_Modular_Integer_Type); + Init_Alignment (T); + Set_Is_Constrained (T); + + if not Is_OK_Static_Expression (Mod_Expr) then + Flag_Non_Static_Expr + ("non-static expression used for modular type bound!", Mod_Expr); + M_Val := 2 ** System_Max_Binary_Modulus_Power; + else + M_Val := Expr_Value (Mod_Expr); + end if; + + if M_Val < 1 then + Error_Msg_N ("modulus value must be positive", Mod_Expr); + M_Val := 2 ** System_Max_Binary_Modulus_Power; + end if; + + Set_Modulus (T, M_Val); + + -- Create bounds for the modular type based on the modulus given in + -- the type declaration and then analyze and resolve those bounds. + + Set_Scalar_Range (T, + Make_Range (Sloc (Mod_Expr), + Low_Bound => + Make_Integer_Literal (Sloc (Mod_Expr), 0), + High_Bound => + Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1))); + + -- Properly analyze the literals for the range. We do this manually + -- because we can't go calling Resolve, since we are resolving these + -- bounds with the type, and this type is certainly not complete yet! + + Set_Etype (Low_Bound (Scalar_Range (T)), T); + Set_Etype (High_Bound (Scalar_Range (T)), T); + Set_Is_Static_Expression (Low_Bound (Scalar_Range (T))); + Set_Is_Static_Expression (High_Bound (Scalar_Range (T))); + + -- Loop through powers of two to find number of bits required + + for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop + + -- Binary case + + if M_Val = 2 ** Bits then + Set_Modular_Size (Bits); + return; + + -- Non-binary case + + elsif M_Val < 2 ** Bits then + Set_Non_Binary_Modulus (T); + + if Bits > System_Max_Nonbinary_Modulus_Power then + Error_Msg_Uint_1 := + UI_From_Int (System_Max_Nonbinary_Modulus_Power); + Error_Msg_N + ("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr); + Set_Modular_Size (System_Max_Binary_Modulus_Power); + return; + + else + -- In the non-binary case, set size as per RM 13.3(55) + + Set_Modular_Size (Bits); + return; + end if; + end if; + + end loop; + + -- If we fall through, then the size exceed System.Max_Binary_Modulus + -- so we just signal an error and set the maximum size. + + Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power); + Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr); + + Set_Modular_Size (System_Max_Binary_Modulus_Power); + Init_Alignment (T); + + end Modular_Type_Declaration; + + -------------------------- + -- New_Concatenation_Op -- + -------------------------- + + procedure New_Concatenation_Op (Typ : Entity_Id) is + Loc : constant Source_Ptr := Sloc (Typ); + Op : Entity_Id; + + function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id; + -- Create abbreviated declaration for the formal of a predefined + -- Operator 'Op' of type 'Typ' + + -------------------- + -- Make_Op_Formal -- + -------------------- + + function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is + Formal : Entity_Id; + begin + Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P'); + Set_Etype (Formal, Typ); + Set_Mechanism (Formal, Default_Mechanism); + return Formal; + end Make_Op_Formal; + + -- Start of processing for New_Concatenation_Op + + begin + Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat); + + Set_Ekind (Op, E_Operator); + Set_Scope (Op, Current_Scope); + Set_Etype (Op, Typ); + Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat)); + Set_Is_Immediately_Visible (Op); + Set_Is_Intrinsic_Subprogram (Op); + Set_Has_Completion (Op); + Append_Entity (Op, Current_Scope); + + Set_Name_Entity_Id (Name_Op_Concat, Op); + + Append_Entity (Make_Op_Formal (Typ, Op), Op); + Append_Entity (Make_Op_Formal (Typ, Op), Op); + end New_Concatenation_Op; + + ------------------------------------------- + -- Ordinary_Fixed_Point_Type_Declaration -- + ------------------------------------------- + + procedure Ordinary_Fixed_Point_Type_Declaration + (T : Entity_Id; + Def : Node_Id) + is + Loc : constant Source_Ptr := Sloc (Def); + Delta_Expr : constant Node_Id := Delta_Expression (Def); + RRS : constant Node_Id := Real_Range_Specification (Def); + Implicit_Base : Entity_Id; + Delta_Val : Ureal; + Small_Val : Ureal; + Low_Val : Ureal; + High_Val : Ureal; + + begin + Check_Restriction (No_Fixed_Point, Def); + + -- Create implicit base type + + Implicit_Base := + Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B'); + Set_Etype (Implicit_Base, Implicit_Base); + + -- Analyze and process delta expression + + Analyze_And_Resolve (Delta_Expr, Any_Real); + + Check_Delta_Expression (Delta_Expr); + Delta_Val := Expr_Value_R (Delta_Expr); + + Set_Delta_Value (Implicit_Base, Delta_Val); + + -- Compute default small from given delta, which is the largest power + -- of two that does not exceed the given delta value. + + declare + Tmp : Ureal; + Scale : Int; + + begin + Tmp := Ureal_1; + Scale := 0; + + if Delta_Val < Ureal_1 then + while Delta_Val < Tmp loop + Tmp := Tmp / Ureal_2; + Scale := Scale + 1; + end loop; + + else + loop + Tmp := Tmp * Ureal_2; + exit when Tmp > Delta_Val; + Scale := Scale - 1; + end loop; + end if; + + Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2); + end; + + Set_Small_Value (Implicit_Base, Small_Val); + + -- If no range was given, set a dummy range + + if RRS <= Empty_Or_Error then + Low_Val := -Small_Val; + High_Val := Small_Val; + + -- Otherwise analyze and process given range + + else + declare + Low : constant Node_Id := Low_Bound (RRS); + High : constant Node_Id := High_Bound (RRS); + + begin + Analyze_And_Resolve (Low, Any_Real); + Analyze_And_Resolve (High, Any_Real); + Check_Real_Bound (Low); + Check_Real_Bound (High); + + -- Obtain and set the range + + Low_Val := Expr_Value_R (Low); + High_Val := Expr_Value_R (High); + + if Low_Val > High_Val then + Error_Msg_NE ("?fixed point type& has null range", Def, T); + end if; + end; + end if; + + -- The range for both the implicit base and the declared first subtype + -- cannot be set yet, so we use the special routine Set_Fixed_Range to + -- set a temporary range in place. Note that the bounds of the base + -- type will be widened to be symmetrical and to fill the available + -- bits when the type is frozen. + + -- We could do this with all discrete types, and probably should, but + -- we absolutely have to do it for fixed-point, since the end-points + -- of the range and the size are determined by the small value, which + -- could be reset before the freeze point. + + Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val); + Set_Fixed_Range (T, Loc, Low_Val, High_Val); + + Init_Size_Align (Implicit_Base); + + -- Complete definition of first subtype + + Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype); + Set_Etype (T, Implicit_Base); + Init_Size_Align (T); + Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base)); + Set_Small_Value (T, Small_Val); + Set_Delta_Value (T, Delta_Val); + Set_Is_Constrained (T); + + end Ordinary_Fixed_Point_Type_Declaration; + + ---------------------------------------- + -- Prepare_Private_Subtype_Completion -- + ---------------------------------------- + + procedure Prepare_Private_Subtype_Completion + (Id : Entity_Id; + Related_Nod : Node_Id) + is + Id_B : constant Entity_Id := Base_Type (Id); + Full_B : constant Entity_Id := Full_View (Id_B); + Full : Entity_Id; + + begin + if Present (Full_B) then + + -- The Base_Type is already completed, we can complete the subtype + -- now. We have to create a new entity with the same name, Thus we + -- can't use Create_Itype. + + -- This is messy, should be fixed ??? + + Full := Make_Defining_Identifier (Sloc (Id), Chars (Id)); + Set_Is_Itype (Full); + Set_Associated_Node_For_Itype (Full, Related_Nod); + Complete_Private_Subtype (Id, Full, Full_B, Related_Nod); + end if; + + -- The parent subtype may be private, but the base might not, in some + -- nested instances. In that case, the subtype does not need to be + -- exchanged. It would still be nice to make private subtypes and their + -- bases consistent at all times ??? + + if Is_Private_Type (Id_B) then + Append_Elmt (Id, Private_Dependents (Id_B)); + end if; + + end Prepare_Private_Subtype_Completion; + + --------------------------- + -- Process_Discriminants -- + --------------------------- + + procedure Process_Discriminants + (N : Node_Id; + Prev : Entity_Id := Empty) + is + Elist : constant Elist_Id := New_Elmt_List; + Id : Node_Id; + Discr : Node_Id; + Discr_Number : Uint; + Discr_Type : Entity_Id; + Default_Present : Boolean := False; + Default_Not_Present : Boolean := False; + + begin + -- A composite type other than an array type can have discriminants. + -- Discriminants of non-limited types must have a discrete type. + -- On entry, the current scope is the composite type. + + -- The discriminants are initially entered into the scope of the type + -- via Enter_Name with the default Ekind of E_Void to prevent premature + -- use, as explained at the end of this procedure. + + Discr := First (Discriminant_Specifications (N)); + while Present (Discr) loop + Enter_Name (Defining_Identifier (Discr)); + + -- For navigation purposes we add a reference to the discriminant + -- in the entity for the type. If the current declaration is a + -- completion, place references on the partial view. Otherwise the + -- type is the current scope. + + if Present (Prev) then + + -- The references go on the partial view, if present. If the + -- partial view has discriminants, the references have been + -- generated already. + + if not Has_Discriminants (Prev) then + Generate_Reference (Prev, Defining_Identifier (Discr), 'd'); + end if; + else + Generate_Reference + (Current_Scope, Defining_Identifier (Discr), 'd'); + end if; + + if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then + Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr)); + + -- Ada 2005 (AI-230): Access discriminants are now allowed for + -- nonlimited types, and are treated like other components of + -- anonymous access types in terms of accessibility. + + if not Is_Concurrent_Type (Current_Scope) + and then not Is_Concurrent_Record_Type (Current_Scope) + and then not Is_Limited_Record (Current_Scope) + and then Ekind (Current_Scope) /= E_Limited_Private_Type + then + Set_Is_Local_Anonymous_Access (Discr_Type); + end if; + + -- Ada 2005 (AI-254) + + if Present (Access_To_Subprogram_Definition + (Discriminant_Type (Discr))) + and then Protected_Present (Access_To_Subprogram_Definition + (Discriminant_Type (Discr))) + then + Discr_Type := + Replace_Anonymous_Access_To_Protected_Subprogram + (Discr, Discr_Type); + end if; + + else + Find_Type (Discriminant_Type (Discr)); + Discr_Type := Etype (Discriminant_Type (Discr)); + + if Error_Posted (Discriminant_Type (Discr)) then + Discr_Type := Any_Type; + end if; + end if; + + if Is_Access_Type (Discr_Type) then + + -- Ada 2005 (AI-230): Access discriminant allowed in non-limited + -- record types + + if Ada_Version < Ada_05 then + Check_Access_Discriminant_Requires_Limited + (Discr, Discriminant_Type (Discr)); + end if; + + if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then + Error_Msg_N + ("(Ada 83) access discriminant not allowed", Discr); + end if; + + elsif not Is_Discrete_Type (Discr_Type) then + Error_Msg_N ("discriminants must have a discrete or access type", + Discriminant_Type (Discr)); + end if; + + Set_Etype (Defining_Identifier (Discr), Discr_Type); + + -- If a discriminant specification includes the assignment compound + -- delimiter followed by an expression, the expression is the default + -- expression of the discriminant; the default expression must be of + -- the type of the discriminant. (RM 3.7.1) Since this expression is + -- a default expression, we do the special preanalysis, since this + -- expression does not freeze (see "Handling of Default and Per- + -- Object Expressions" in spec of package Sem). + + if Present (Expression (Discr)) then + Analyze_Per_Use_Expression (Expression (Discr), Discr_Type); + + if Nkind (N) = N_Formal_Type_Declaration then + Error_Msg_N + ("discriminant defaults not allowed for formal type", + Expression (Discr)); + + -- Tagged types cannot have defaulted discriminants, but a + -- non-tagged private type with defaulted discriminants + -- can have a tagged completion. + + elsif Is_Tagged_Type (Current_Scope) + and then Comes_From_Source (N) + then + Error_Msg_N + ("discriminants of tagged type cannot have defaults", + Expression (Discr)); + + else + Default_Present := True; + Append_Elmt (Expression (Discr), Elist); + + -- Tag the defining identifiers for the discriminants with + -- their corresponding default expressions from the tree. + + Set_Discriminant_Default_Value + (Defining_Identifier (Discr), Expression (Discr)); + end if; + + else + Default_Not_Present := True; + end if; + + -- Ada 2005 (AI-231): Create an Itype that is a duplicate of + -- Discr_Type but with the null-exclusion attribute + + if Ada_Version >= Ada_05 then + + -- Ada 2005 (AI-231): Static checks + + if Can_Never_Be_Null (Discr_Type) then + Null_Exclusion_Static_Checks (Discr); + + elsif Is_Access_Type (Discr_Type) + and then Null_Exclusion_Present (Discr) + + -- No need to check itypes because in their case this check + -- was done at their point of creation + + and then not Is_Itype (Discr_Type) + then + if Can_Never_Be_Null (Discr_Type) then + Error_Msg_N + ("(Ada 2005) already a null-excluding type", Discr); + end if; + + Set_Etype (Defining_Identifier (Discr), + Create_Null_Excluding_Itype + (T => Discr_Type, + Related_Nod => Discr)); + end if; + + end if; + + Next (Discr); + end loop; + + -- An element list consisting of the default expressions of the + -- discriminants is constructed in the above loop and used to set + -- the Discriminant_Constraint attribute for the type. If an object + -- is declared of this (record or task) type without any explicit + -- discriminant constraint given, this element list will form the + -- actual parameters for the corresponding initialization procedure + -- for the type. + + Set_Discriminant_Constraint (Current_Scope, Elist); + Set_Stored_Constraint (Current_Scope, No_Elist); + + -- Default expressions must be provided either for all or for none + -- of the discriminants of a discriminant part. (RM 3.7.1) + + if Default_Present and then Default_Not_Present then + Error_Msg_N + ("incomplete specification of defaults for discriminants", N); + end if; + + -- The use of the name of a discriminant is not allowed in default + -- expressions of a discriminant part if the specification of the + -- discriminant is itself given in the discriminant part. (RM 3.7.1) + + -- To detect this, the discriminant names are entered initially with an + -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any + -- attempt to use a void entity (for example in an expression that is + -- type-checked) produces the error message: premature usage. Now after + -- completing the semantic analysis of the discriminant part, we can set + -- the Ekind of all the discriminants appropriately. + + Discr := First (Discriminant_Specifications (N)); + Discr_Number := Uint_1; + while Present (Discr) loop + Id := Defining_Identifier (Discr); + Set_Ekind (Id, E_Discriminant); + Init_Component_Location (Id); + Init_Esize (Id); + Set_Discriminant_Number (Id, Discr_Number); + + -- Make sure this is always set, even in illegal programs + + Set_Corresponding_Discriminant (Id, Empty); + + -- Initialize the Original_Record_Component to the entity itself. + -- Inherit_Components will propagate the right value to + -- discriminants in derived record types. + + Set_Original_Record_Component (Id, Id); + + -- Create the discriminal for the discriminant + + Build_Discriminal (Id); + + Next (Discr); + Discr_Number := Discr_Number + 1; + end loop; + + Set_Has_Discriminants (Current_Scope); + end Process_Discriminants; + + ----------------------- + -- Process_Full_View -- + ----------------------- + + procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is + Priv_Parent : Entity_Id; + Full_Parent : Entity_Id; + Full_Indic : Node_Id; + + procedure Collect_Implemented_Interfaces + (Typ : Entity_Id; + Ifaces : Elist_Id); + -- Ada 2005: Gather all the interfaces that Typ directly or + -- inherently implements. Duplicate entries are not added to + -- the list Ifaces. + + function Contain_Interface + (Iface : Entity_Id; + Ifaces : Elist_Id) return Boolean; + -- Ada 2005: Determine whether Iface is present in the list Ifaces + + function Find_Hidden_Interface + (Src : Elist_Id; + Dest : Elist_Id) return Entity_Id; + -- Ada 2005: Determine whether the interfaces in list Src are all + -- present in the list Dest. Return the first differing interface, + -- or Empty otherwise. + + ------------------------------------ + -- Collect_Implemented_Interfaces -- + ------------------------------------ + + procedure Collect_Implemented_Interfaces + (Typ : Entity_Id; + Ifaces : Elist_Id) + is + Iface : Entity_Id; + Iface_Elmt : Elmt_Id; + + begin + -- Abstract interfaces are only associated with tagged record types + + if not Is_Tagged_Type (Typ) + or else not Is_Record_Type (Typ) + then + return; + end if; + + -- Implementations of the form: + -- type Typ is new Iface ... + + if Is_Interface (Etype (Typ)) + and then not Contain_Interface (Etype (Typ), Ifaces) + then + Append_Elmt (Etype (Typ), Ifaces); + end if; + + -- Implementations of the form: + -- type Typ is ... and Iface ... + + if Present (Abstract_Interfaces (Typ)) then + Iface_Elmt := First_Elmt (Abstract_Interfaces (Typ)); + while Present (Iface_Elmt) loop + Iface := Node (Iface_Elmt); + + pragma Assert (Is_Interface (Iface)); + + if not Contain_Interface (Iface, Ifaces) then + Append_Elmt (Iface, Ifaces); + Collect_Implemented_Interfaces (Iface, Ifaces); + end if; + + Next_Elmt (Iface_Elmt); + end loop; + end if; + + -- Implementations of the form: + -- type Typ is new Parent_Typ and ... + + if Ekind (Typ) = E_Record_Type + and then Present (Parent_Subtype (Typ)) + then + Collect_Implemented_Interfaces (Parent_Subtype (Typ), Ifaces); + + -- Implementations of the form: + -- type Typ is ... with private; + + elsif Ekind (Typ) = E_Record_Type_With_Private + and then Present (Full_View (Typ)) + and then Etype (Typ) /= Full_View (Typ) + and then Etype (Typ) /= Typ + then + Collect_Implemented_Interfaces (Etype (Typ), Ifaces); + end if; + end Collect_Implemented_Interfaces; + + ----------------------- + -- Contain_Interface -- + ----------------------- + + function Contain_Interface + (Iface : Entity_Id; + Ifaces : Elist_Id) return Boolean + is + Iface_Elmt : Elmt_Id; + + begin + if Present (Ifaces) then + Iface_Elmt := First_Elmt (Ifaces); + while Present (Iface_Elmt) loop + if Node (Iface_Elmt) = Iface then + return True; + end if; + + Next_Elmt (Iface_Elmt); + end loop; + end if; + + return False; + end Contain_Interface; + + --------------------------- + -- Find_Hidden_Interface -- + --------------------------- + + function Find_Hidden_Interface + (Src : Elist_Id; + Dest : Elist_Id) return Entity_Id + is + Iface : Entity_Id; + Iface_Elmt : Elmt_Id; + + begin + if Present (Src) and then Present (Dest) then + Iface_Elmt := First_Elmt (Src); + while Present (Iface_Elmt) loop + Iface := Node (Iface_Elmt); + + if not Contain_Interface (Iface, Dest) then + return Iface; + end if; + + Next_Elmt (Iface_Elmt); + end loop; + end if; + + return Empty; + end Find_Hidden_Interface; + + -- Start of processing for Process_Full_View + + begin + -- First some sanity checks that must be done after semantic + -- decoration of the full view and thus cannot be placed with other + -- similar checks in Find_Type_Name + + if not Is_Limited_Type (Priv_T) + and then (Is_Limited_Type (Full_T) + or else Is_Limited_Composite (Full_T)) + then + Error_Msg_N + ("completion of nonlimited type cannot be limited", Full_T); + Explain_Limited_Type (Full_T, Full_T); + + elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then + Error_Msg_N + ("completion of nonabstract type cannot be abstract", Full_T); + + elsif Is_Tagged_Type (Priv_T) + and then Is_Limited_Type (Priv_T) + and then not Is_Limited_Type (Full_T) + then + -- GNAT allow its own definition of Limited_Controlled to disobey + -- this rule in order in ease the implementation. The next test is + -- safe because Root_Controlled is defined in a private system child + + if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then + Set_Is_Limited_Composite (Full_T); + else + Error_Msg_N + ("completion of limited tagged type must be limited", Full_T); + end if; + + elsif Is_Generic_Type (Priv_T) then + Error_Msg_N ("generic type cannot have a completion", Full_T); + end if; + + if Ada_Version >= Ada_05 + and then Is_Tagged_Type (Priv_T) + and then Is_Tagged_Type (Full_T) + then + declare + Iface : Entity_Id; + Priv_T_Ifaces : constant Elist_Id := New_Elmt_List; + Full_T_Ifaces : constant Elist_Id := New_Elmt_List; + + begin + Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces); + Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces); + + -- Ada 2005 (AI-251): The partial view shall be a descendant of + -- an interface type if and only if the full type is descendant + -- of the interface type (AARM 7.3 (7.3/2). + + Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces); + + if Present (Iface) then + Error_Msg_NE ("interface & not implemented by full type " & + "('R'M'-2005 7.3 (7.3/2))", Priv_T, Iface); + end if; + + Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces); + + if Present (Iface) then + Error_Msg_NE ("interface & not implemented by partial view " & + "('R'M'-2005 7.3 (7.3/2))", Full_T, Iface); + end if; + end; + end if; + + if Is_Tagged_Type (Priv_T) + and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration + and then Is_Derived_Type (Full_T) + then + Priv_Parent := Etype (Priv_T); + + -- The full view of a private extension may have been transformed + -- into an unconstrained derived type declaration and a subtype + -- declaration (see build_derived_record_type for details). + + if Nkind (N) = N_Subtype_Declaration then + Full_Indic := Subtype_Indication (N); + Full_Parent := Etype (Base_Type (Full_T)); + else + Full_Indic := Subtype_Indication (Type_Definition (N)); + Full_Parent := Etype (Full_T); + end if; + + -- Check that the parent type of the full type is a descendant of + -- the ancestor subtype given in the private extension. If either + -- entity has an Etype equal to Any_Type then we had some previous + -- error situation [7.3(8)]. + + if Priv_Parent = Any_Type or else Full_Parent = Any_Type then + return; + + -- Ada 2005 (AI-251): Interfaces in the full-typ can be given in + -- any order. Therefore we don't have to check that its parent must + -- be a descendant of the parent of the private type declaration. + + elsif Is_Interface (Priv_Parent) + and then Is_Interface (Full_Parent) + then + null; + + -- Ada 2005 (AI-251): If the parent of the private type declaration + -- is an interface there is no need to check that it is an ancestor + -- of the associated full type declaration. The required tests for + -- this case case are performed by Build_Derived_Record_Type. + + elsif not Is_Interface (Base_Type (Priv_Parent)) + and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent) + then + Error_Msg_N + ("parent of full type must descend from parent" + & " of private extension", Full_Indic); + + -- Check the rules of 7.3(10): if the private extension inherits + -- known discriminants, then the full type must also inherit those + -- discriminants from the same (ancestor) type, and the parent + -- subtype of the full type must be constrained if and only if + -- the ancestor subtype of the private extension is constrained. + + elsif No (Discriminant_Specifications (Parent (Priv_T))) + and then not Has_Unknown_Discriminants (Priv_T) + and then Has_Discriminants (Base_Type (Priv_Parent)) + then + declare + Priv_Indic : constant Node_Id := + Subtype_Indication (Parent (Priv_T)); + + Priv_Constr : constant Boolean := + Is_Constrained (Priv_Parent) + or else + Nkind (Priv_Indic) = N_Subtype_Indication + or else Is_Constrained (Entity (Priv_Indic)); + + Full_Constr : constant Boolean := + Is_Constrained (Full_Parent) + or else + Nkind (Full_Indic) = N_Subtype_Indication + or else Is_Constrained (Entity (Full_Indic)); + + Priv_Discr : Entity_Id; + Full_Discr : Entity_Id; + + begin + Priv_Discr := First_Discriminant (Priv_Parent); + Full_Discr := First_Discriminant (Full_Parent); + while Present (Priv_Discr) and then Present (Full_Discr) loop + if Original_Record_Component (Priv_Discr) = + Original_Record_Component (Full_Discr) + or else + Corresponding_Discriminant (Priv_Discr) = + Corresponding_Discriminant (Full_Discr) + then + null; + else + exit; + end if; + + Next_Discriminant (Priv_Discr); + Next_Discriminant (Full_Discr); + end loop; + + if Present (Priv_Discr) or else Present (Full_Discr) then + Error_Msg_N + ("full view must inherit discriminants of the parent type" + & " used in the private extension", Full_Indic); + + elsif Priv_Constr and then not Full_Constr then + Error_Msg_N + ("parent subtype of full type must be constrained", + Full_Indic); + + elsif Full_Constr and then not Priv_Constr then + Error_Msg_N + ("parent subtype of full type must be unconstrained", + Full_Indic); + end if; + end; + + -- Check the rules of 7.3(12): if a partial view has neither known + -- or unknown discriminants, then the full type declaration shall + -- define a definite subtype. + + elsif not Has_Unknown_Discriminants (Priv_T) + and then not Has_Discriminants (Priv_T) + and then not Is_Constrained (Full_T) + then + Error_Msg_N + ("full view must define a constrained type if partial view" + & " has no discriminants", Full_T); + end if; + + -- ??????? Do we implement the following properly ????? + -- If the ancestor subtype of a private extension has constrained + -- discriminants, then the parent subtype of the full view shall + -- impose a statically matching constraint on those discriminants + -- [7.3(13)]. + + else + -- For untagged types, verify that a type without discriminants + -- is not completed with an unconstrained type. + + if not Is_Indefinite_Subtype (Priv_T) + and then Is_Indefinite_Subtype (Full_T) + then + Error_Msg_N ("full view of type must be definite subtype", Full_T); + end if; + end if; + + -- AI-419: verify that the use of "limited" is consistent + + declare + Orig_Decl : constant Node_Id := Original_Node (N); + begin + if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration + and then not Limited_Present (Parent (Priv_T)) + and then Nkind (Orig_Decl) = N_Full_Type_Declaration + and then Nkind + (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition + and then Limited_Present (Type_Definition (Orig_Decl)) + then + Error_Msg_N + ("full view of non-limited extension cannot be limited", N); + end if; + end; + + -- Ada 2005 AI-363: if the full view has discriminants with + -- defaults, it is illegal to declare constrained access subtypes + -- whose designated type is the current type. This allows objects + -- of the type that are declared in the heap to be unconstrained. + + if not Has_Unknown_Discriminants (Priv_T) + and then not Has_Discriminants (Priv_T) + and then Has_Discriminants (Full_T) + and then + Present + (Discriminant_Default_Value (First_Discriminant (Full_T))) + then + Set_Has_Constrained_Partial_View (Full_T); + Set_Has_Constrained_Partial_View (Priv_T); + end if; + + -- Create a full declaration for all its subtypes recorded in + -- Private_Dependents and swap them similarly to the base type. These + -- are subtypes that have been define before the full declaration of + -- the private type. We also swap the entry in Private_Dependents list + -- so we can properly restore the private view on exit from the scope. + + declare + Priv_Elmt : Elmt_Id; + Priv : Entity_Id; + Full : Entity_Id; + + begin + Priv_Elmt := First_Elmt (Private_Dependents (Priv_T)); + while Present (Priv_Elmt) loop + Priv := Node (Priv_Elmt); + + if Ekind (Priv) = E_Private_Subtype + or else Ekind (Priv) = E_Limited_Private_Subtype + or else Ekind (Priv) = E_Record_Subtype_With_Private + then + Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv)); + Set_Is_Itype (Full); + Set_Parent (Full, Parent (Priv)); + Set_Associated_Node_For_Itype (Full, N); + + -- Now we need to complete the private subtype, but since the + -- base type has already been swapped, we must also swap the + -- subtypes (and thus, reverse the arguments in the call to + -- Complete_Private_Subtype). + + Copy_And_Swap (Priv, Full); + Complete_Private_Subtype (Full, Priv, Full_T, N); + Replace_Elmt (Priv_Elmt, Full); + end if; + + Next_Elmt (Priv_Elmt); + end loop; + end; + + -- If the private view was tagged, copy the new Primitive + -- operations from the private view to the full view. + + if Is_Tagged_Type (Full_T) then + declare + Priv_List : Elist_Id; + Full_List : constant Elist_Id := Primitive_Operations (Full_T); + P1, P2 : Elmt_Id; + Prim : Entity_Id; + D_Type : Entity_Id; + + begin + if Is_Tagged_Type (Priv_T) then + Priv_List := Primitive_Operations (Priv_T); + + P1 := First_Elmt (Priv_List); + while Present (P1) loop + Prim := Node (P1); + + -- Transfer explicit primitives, not those inherited from + -- parent of partial view, which will be re-inherited on + -- the full view. + + if Comes_From_Source (Prim) then + P2 := First_Elmt (Full_List); + while Present (P2) and then Node (P2) /= Prim loop + Next_Elmt (P2); + end loop; + + -- If not found, that is a new one + + if No (P2) then + Append_Elmt (Prim, Full_List); + end if; + end if; + + Next_Elmt (P1); + end loop; + + else + -- In this case the partial view is untagged, so here we + -- locate all of the earlier primitives that need to be + -- treated as dispatching (those that appear between the two + -- views). Note that these additional operations must all be + -- new operations (any earlier operations that override + -- inherited operations of the full view will already have + -- been inserted in the primitives list and marked as + -- dispatching by Check_Operation_From_Private_View. Note that + -- implicit "/=" operators are excluded from being added to + -- the primitives list since they shouldn't be treated as + -- dispatching (tagged "/=" is handled specially). + + Prim := Next_Entity (Full_T); + while Present (Prim) and then Prim /= Priv_T loop + if Ekind (Prim) = E_Procedure + or else + Ekind (Prim) = E_Function + then + + D_Type := Find_Dispatching_Type (Prim); + + if D_Type = Full_T + and then (Chars (Prim) /= Name_Op_Ne + or else Comes_From_Source (Prim)) + then + Check_Controlling_Formals (Full_T, Prim); + + if not Is_Dispatching_Operation (Prim) then + Append_Elmt (Prim, Full_List); + Set_Is_Dispatching_Operation (Prim, True); + Set_DT_Position (Prim, No_Uint); + end if; + + elsif Is_Dispatching_Operation (Prim) + and then D_Type /= Full_T + then + + -- Verify that it is not otherwise controlled by + -- a formal or a return value of type T. + + Check_Controlling_Formals (D_Type, Prim); + end if; + end if; + + Next_Entity (Prim); + end loop; + end if; + + -- For the tagged case, the two views can share the same + -- Primitive Operation list and the same class wide type. + -- Update attributes of the class-wide type which depend on + -- the full declaration. + + if Is_Tagged_Type (Priv_T) then + Set_Primitive_Operations (Priv_T, Full_List); + Set_Class_Wide_Type + (Base_Type (Full_T), Class_Wide_Type (Priv_T)); + + -- Any other attributes should be propagated to C_W ??? + + Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T)); + + end if; + end; + end if; + end Process_Full_View; + + ----------------------------------- + -- Process_Incomplete_Dependents -- + ----------------------------------- + + procedure Process_Incomplete_Dependents + (N : Node_Id; + Full_T : Entity_Id; + Inc_T : Entity_Id) + is + Inc_Elmt : Elmt_Id; + Priv_Dep : Entity_Id; + New_Subt : Entity_Id; + + Disc_Constraint : Elist_Id; + + begin + if No (Private_Dependents (Inc_T)) then + return; + end if; + + -- Itypes that may be generated by the completion of an incomplete + -- subtype are not used by the back-end and not attached to the tree. + -- They are created only for constraint-checking purposes. + + Inc_Elmt := First_Elmt (Private_Dependents (Inc_T)); + while Present (Inc_Elmt) loop + Priv_Dep := Node (Inc_Elmt); + + if Ekind (Priv_Dep) = E_Subprogram_Type then + + -- An Access_To_Subprogram type may have a return type or a + -- parameter type that is incomplete. Replace with the full view. + + if Etype (Priv_Dep) = Inc_T then + Set_Etype (Priv_Dep, Full_T); + end if; + + declare + Formal : Entity_Id; + + begin + Formal := First_Formal (Priv_Dep); + while Present (Formal) loop + if Etype (Formal) = Inc_T then + Set_Etype (Formal, Full_T); + end if; + + Next_Formal (Formal); + end loop; + end; + + elsif Is_Overloadable (Priv_Dep) then + + -- A protected operation is never dispatching: only its + -- wrapper operation (which has convention Ada) is. + + if Is_Tagged_Type (Full_T) + and then Convention (Priv_Dep) /= Convention_Protected + then + + -- Subprogram has an access parameter whose designated type + -- was incomplete. Reexamine declaration now, because it may + -- be a primitive operation of the full type. + + Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T); + Set_Is_Dispatching_Operation (Priv_Dep); + Check_Controlling_Formals (Full_T, Priv_Dep); + end if; + + elsif Ekind (Priv_Dep) = E_Subprogram_Body then + + -- Can happen during processing of a body before the completion + -- of a TA type. Ignore, because spec is also on dependent list. + + return; + + -- Dependent is a subtype + + else + -- We build a new subtype indication using the full view of the + -- incomplete parent. The discriminant constraints have been + -- elaborated already at the point of the subtype declaration. + + New_Subt := Create_Itype (E_Void, N); + + if Has_Discriminants (Full_T) then + Disc_Constraint := Discriminant_Constraint (Priv_Dep); + else + Disc_Constraint := No_Elist; + end if; + + Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N); + Set_Full_View (Priv_Dep, New_Subt); + end if; + + Next_Elmt (Inc_Elmt); + end loop; + end Process_Incomplete_Dependents; + + -------------------------------- + -- Process_Range_Expr_In_Decl -- + -------------------------------- + + procedure Process_Range_Expr_In_Decl + (R : Node_Id; + T : Entity_Id; + Check_List : List_Id := Empty_List; + R_Check_Off : Boolean := False) + is + Lo, Hi : Node_Id; + R_Checks : Check_Result; + Type_Decl : Node_Id; + Def_Id : Entity_Id; + + begin + Analyze_And_Resolve (R, Base_Type (T)); + + if Nkind (R) = N_Range then + Lo := Low_Bound (R); + Hi := High_Bound (R); + + -- If there were errors in the declaration, try and patch up some + -- common mistakes in the bounds. The cases handled are literals + -- which are Integer where the expected type is Real and vice versa. + -- These corrections allow the compilation process to proceed further + -- along since some basic assumptions of the format of the bounds + -- are guaranteed. + + if Etype (R) = Any_Type then + + if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then + Rewrite (Lo, + Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo)))); + + elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then + Rewrite (Hi, + Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi)))); + + elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then + Rewrite (Lo, + Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo)))); + + elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then + Rewrite (Hi, + Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi)))); + end if; + + Set_Etype (Lo, T); + Set_Etype (Hi, T); + end if; + + -- If the bounds of the range have been mistakenly given as string + -- literals (perhaps in place of character literals), then an error + -- has already been reported, but we rewrite the string literal as a + -- bound of the range's type to avoid blowups in later processing + -- that looks at static values. + + if Nkind (Lo) = N_String_Literal then + Rewrite (Lo, + Make_Attribute_Reference (Sloc (Lo), + Attribute_Name => Name_First, + Prefix => New_Reference_To (T, Sloc (Lo)))); + Analyze_And_Resolve (Lo); + end if; + + if Nkind (Hi) = N_String_Literal then + Rewrite (Hi, + Make_Attribute_Reference (Sloc (Hi), + Attribute_Name => Name_First, + Prefix => New_Reference_To (T, Sloc (Hi)))); + Analyze_And_Resolve (Hi); + end if; + + -- If bounds aren't scalar at this point then exit, avoiding + -- problems with further processing of the range in this procedure. + + if not Is_Scalar_Type (Etype (Lo)) then + return; + end if; + + -- Resolve (actually Sem_Eval) has checked that the bounds are in + -- then range of the base type. Here we check whether the bounds + -- are in the range of the subtype itself. Note that if the bounds + -- represent the null range the Constraint_Error exception should + -- not be raised. + + -- ??? The following code should be cleaned up as follows + + -- 1. The Is_Null_Range (Lo, Hi) test should disappear since it + -- is done in the call to Range_Check (R, T); below + + -- 2. The use of R_Check_Off should be investigated and possibly + -- removed, this would clean up things a bit. + + if Is_Null_Range (Lo, Hi) then + null; + + else + -- Capture values of bounds and generate temporaries for them + -- if needed, before applying checks, since checks may cause + -- duplication of the expression without forcing evaluation. + + if Expander_Active then + Force_Evaluation (Lo); + Force_Evaluation (Hi); + end if; + + -- We use a flag here instead of suppressing checks on the + -- type because the type we check against isn't necessarily + -- the place where we put the check. + + if not R_Check_Off then + R_Checks := Range_Check (R, T); + + -- Look up tree to find an appropriate insertion point. + -- This seems really junk code, and very brittle, couldn't + -- we just use an insert actions call of some kind ??? + + Type_Decl := Parent (R); + while Present (Type_Decl) and then not + (Nkind (Type_Decl) = N_Full_Type_Declaration + or else + Nkind (Type_Decl) = N_Subtype_Declaration + or else + Nkind (Type_Decl) = N_Loop_Statement + or else + Nkind (Type_Decl) = N_Task_Type_Declaration + or else + Nkind (Type_Decl) = N_Single_Task_Declaration + or else + Nkind (Type_Decl) = N_Protected_Type_Declaration + or else + Nkind (Type_Decl) = N_Single_Protected_Declaration) + loop + Type_Decl := Parent (Type_Decl); + end loop; + + -- Why would Type_Decl not be present??? Without this test, + -- short regression tests fail. + + if Present (Type_Decl) then + + -- Case of loop statement (more comments ???) + + if Nkind (Type_Decl) = N_Loop_Statement then + declare + Indic : Node_Id; + + begin + Indic := Parent (R); + while Present (Indic) and then not + (Nkind (Indic) = N_Subtype_Indication) + loop + Indic := Parent (Indic); + end loop; + + if Present (Indic) then + Def_Id := Etype (Subtype_Mark (Indic)); + + Insert_Range_Checks + (R_Checks, + Type_Decl, + Def_Id, + Sloc (Type_Decl), + R, + Do_Before => True); + end if; + end; + + -- All other cases (more comments ???) + + else + Def_Id := Defining_Identifier (Type_Decl); + + if (Ekind (Def_Id) = E_Record_Type + and then Depends_On_Discriminant (R)) + or else + (Ekind (Def_Id) = E_Protected_Type + and then Has_Discriminants (Def_Id)) + then + Append_Range_Checks + (R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R); + + else + Insert_Range_Checks + (R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R); + + end if; + end if; + end if; + end if; + end if; + + elsif Expander_Active then + Get_Index_Bounds (R, Lo, Hi); + Force_Evaluation (Lo); + Force_Evaluation (Hi); + end if; + end Process_Range_Expr_In_Decl; + + -------------------------------------- + -- Process_Real_Range_Specification -- + -------------------------------------- + + procedure Process_Real_Range_Specification (Def : Node_Id) is + Spec : constant Node_Id := Real_Range_Specification (Def); + Lo : Node_Id; + Hi : Node_Id; + Err : Boolean := False; + + procedure Analyze_Bound (N : Node_Id); + -- Analyze and check one bound + + ------------------- + -- Analyze_Bound -- + ------------------- + + procedure Analyze_Bound (N : Node_Id) is + begin + Analyze_And_Resolve (N, Any_Real); + + if not Is_OK_Static_Expression (N) then + Flag_Non_Static_Expr + ("bound in real type definition is not static!", N); + Err := True; + end if; + end Analyze_Bound; + + -- Start of processing for Process_Real_Range_Specification + + begin + if Present (Spec) then + Lo := Low_Bound (Spec); + Hi := High_Bound (Spec); + Analyze_Bound (Lo); + Analyze_Bound (Hi); + + -- If error, clear away junk range specification + + if Err then + Set_Real_Range_Specification (Def, Empty); + end if; + end if; + end Process_Real_Range_Specification; + + --------------------- + -- Process_Subtype -- + --------------------- + + function Process_Subtype + (S : Node_Id; + Related_Nod : Node_Id; + Related_Id : Entity_Id := Empty; + Suffix : Character := ' ') return Entity_Id + is + P : Node_Id; + Def_Id : Entity_Id; + Error_Node : Node_Id; + Full_View_Id : Entity_Id; + Subtype_Mark_Id : Entity_Id; + + May_Have_Null_Exclusion : Boolean; + + procedure Check_Incomplete (T : Entity_Id); + -- Called to verify that an incomplete type is not used prematurely + + ---------------------- + -- Check_Incomplete -- + ---------------------- + + procedure Check_Incomplete (T : Entity_Id) is + begin + if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then + Error_Msg_N ("invalid use of type before its full declaration", T); + end if; + end Check_Incomplete; + + -- Start of processing for Process_Subtype + + begin + -- Case of no constraints present + + if Nkind (S) /= N_Subtype_Indication then + + Find_Type (S); + Check_Incomplete (S); + P := Parent (S); + + -- Ada 2005 (AI-231): Static check + + if Ada_Version >= Ada_05 + and then Present (P) + and then Null_Exclusion_Present (P) + and then Nkind (P) /= N_Access_To_Object_Definition + and then not Is_Access_Type (Entity (S)) + then + Error_Msg_N + ("(Ada 2005) the null-exclusion part requires an access type", + S); + end if; + + May_Have_Null_Exclusion := + Nkind (P) = N_Access_Definition + or else Nkind (P) = N_Access_Function_Definition + or else Nkind (P) = N_Access_Procedure_Definition + or else Nkind (P) = N_Access_To_Object_Definition + or else Nkind (P) = N_Allocator + or else Nkind (P) = N_Component_Definition + or else Nkind (P) = N_Derived_Type_Definition + or else Nkind (P) = N_Discriminant_Specification + or else Nkind (P) = N_Object_Declaration + or else Nkind (P) = N_Parameter_Specification + or else Nkind (P) = N_Subtype_Declaration; + + -- Create an Itype that is a duplicate of Entity (S) but with the + -- null-exclusion attribute + + if May_Have_Null_Exclusion + and then Is_Access_Type (Entity (S)) + and then Null_Exclusion_Present (P) + + -- No need to check the case of an access to object definition. + -- It is correct to define double not-null pointers. + -- Example: + -- type Not_Null_Int_Ptr is not null access Integer; + -- type Acc is not null access Not_Null_Int_Ptr; + + and then Nkind (P) /= N_Access_To_Object_Definition + then + if Can_Never_Be_Null (Entity (S)) then + case Nkind (Related_Nod) is + when N_Full_Type_Declaration => + if Nkind (Type_Definition (Related_Nod)) + in N_Array_Type_Definition + then + Error_Node := + Subtype_Indication + (Component_Definition + (Type_Definition (Related_Nod))); + else + Error_Node := + Subtype_Indication (Type_Definition (Related_Nod)); + end if; + + when N_Subtype_Declaration => + Error_Node := Subtype_Indication (Related_Nod); + + when N_Object_Declaration => + Error_Node := Object_Definition (Related_Nod); + + when N_Component_Declaration => + Error_Node := + Subtype_Indication (Component_Definition (Related_Nod)); + + when others => + pragma Assert (False); + Error_Node := Related_Nod; + end case; + + Error_Msg_N + ("(Ada 2005) already a null-excluding type", Error_Node); + end if; + + Set_Etype (S, + Create_Null_Excluding_Itype + (T => Entity (S), + Related_Nod => P)); + Set_Entity (S, Etype (S)); + end if; + + return Entity (S); + + -- Case of constraint present, so that we have an N_Subtype_Indication + -- node (this node is created only if constraints are present). + + else + + Find_Type (Subtype_Mark (S)); + + if Nkind (Parent (S)) /= N_Access_To_Object_Definition + and then not + (Nkind (Parent (S)) = N_Subtype_Declaration + and then Is_Itype (Defining_Identifier (Parent (S)))) + then + Check_Incomplete (Subtype_Mark (S)); + end if; + + P := Parent (S); + Subtype_Mark_Id := Entity (Subtype_Mark (S)); + + -- Explicit subtype declaration case + + if Nkind (P) = N_Subtype_Declaration then + Def_Id := Defining_Identifier (P); + + -- Explicit derived type definition case + + elsif Nkind (P) = N_Derived_Type_Definition then + Def_Id := Defining_Identifier (Parent (P)); + + -- Implicit case, the Def_Id must be created as an implicit type. + -- The one exception arises in the case of concurrent types, array + -- and access types, where other subsidiary implicit types may be + -- created and must appear before the main implicit type. In these + -- cases we leave Def_Id set to Empty as a signal that Create_Itype + -- has not yet been called to create Def_Id. + + else + if Is_Array_Type (Subtype_Mark_Id) + or else Is_Concurrent_Type (Subtype_Mark_Id) + or else Is_Access_Type (Subtype_Mark_Id) + then + Def_Id := Empty; + + -- For the other cases, we create a new unattached Itype, + -- and set the indication to ensure it gets attached later. + + else + Def_Id := + Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); + end if; + end if; + + -- If the kind of constraint is invalid for this kind of type, + -- then give an error, and then pretend no constraint was given. + + if not Is_Valid_Constraint_Kind + (Ekind (Subtype_Mark_Id), Nkind (Constraint (S))) + then + Error_Msg_N + ("incorrect constraint for this kind of type", Constraint (S)); + + Rewrite (S, New_Copy_Tree (Subtype_Mark (S))); + + -- Set Ekind of orphan itype, to prevent cascaded errors + + if Present (Def_Id) then + Set_Ekind (Def_Id, Ekind (Any_Type)); + end if; + + -- Make recursive call, having got rid of the bogus constraint + + return Process_Subtype (S, Related_Nod, Related_Id, Suffix); + end if; + + -- Remaining processing depends on type + + case Ekind (Subtype_Mark_Id) is + when Access_Kind => + Constrain_Access (Def_Id, S, Related_Nod); + + when Array_Kind => + Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix); + + when Decimal_Fixed_Point_Kind => + Constrain_Decimal (Def_Id, S); + + when Enumeration_Kind => + Constrain_Enumeration (Def_Id, S); + + when Ordinary_Fixed_Point_Kind => + Constrain_Ordinary_Fixed (Def_Id, S); + + when Float_Kind => + Constrain_Float (Def_Id, S); + + when Integer_Kind => + Constrain_Integer (Def_Id, S); + + when E_Record_Type | + E_Record_Subtype | + Class_Wide_Kind | + E_Incomplete_Type => + Constrain_Discriminated_Type (Def_Id, S, Related_Nod); + + when Private_Kind => + Constrain_Discriminated_Type (Def_Id, S, Related_Nod); + Set_Private_Dependents (Def_Id, New_Elmt_List); + + -- In case of an invalid constraint prevent further processing + -- since the type constructed is missing expected fields. + + if Etype (Def_Id) = Any_Type then + return Def_Id; + end if; + + -- If the full view is that of a task with discriminants, + -- we must constrain both the concurrent type and its + -- corresponding record type. Otherwise we will just propagate + -- the constraint to the full view, if available. + + if Present (Full_View (Subtype_Mark_Id)) + and then Has_Discriminants (Subtype_Mark_Id) + and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id)) + then + Full_View_Id := + Create_Itype (E_Void, Related_Nod, Related_Id, Suffix); + + Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id)); + Constrain_Concurrent (Full_View_Id, S, + Related_Nod, Related_Id, Suffix); + Set_Entity (Subtype_Mark (S), Subtype_Mark_Id); + Set_Full_View (Def_Id, Full_View_Id); + + else + Prepare_Private_Subtype_Completion (Def_Id, Related_Nod); + end if; + + when Concurrent_Kind => + Constrain_Concurrent (Def_Id, S, + Related_Nod, Related_Id, Suffix); + + when others => + Error_Msg_N ("invalid subtype mark in subtype indication", S); + end case; + + -- Size and Convention are always inherited from the base type + + Set_Size_Info (Def_Id, (Subtype_Mark_Id)); + Set_Convention (Def_Id, Convention (Subtype_Mark_Id)); + + return Def_Id; + end if; + end Process_Subtype; + + ----------------------------- + -- Record_Type_Declaration -- + ----------------------------- + + procedure Record_Type_Declaration + (T : Entity_Id; + N : Node_Id; + Prev : Entity_Id) + is + Loc : constant Source_Ptr := Sloc (N); + Def : constant Node_Id := Type_Definition (N); + Inc_T : Entity_Id := Empty; + + Is_Tagged : Boolean; + Tag_Comp : Entity_Id; + + procedure Check_Anonymous_Access_Types (Comp_List : Node_Id); + -- Ada 2005 AI-382: an access component in a record declaration can + -- refer to the enclosing record, in which case it denotes the type + -- itself, and not the current instance of the type. We create an + -- anonymous access type for the component, and flag it as an access + -- to a component, so that accessibility checks are properly performed + -- on it. The declaration of the access type is placed ahead of that + -- of the record, to prevent circular order-of-elaboration issues in + -- Gigi. We create an incomplete type for the record declaration, which + -- is the designated type of the anonymous access. + + procedure Make_Incomplete_Type_Declaration; + -- If the record type contains components that include an access to the + -- current record, create an incomplete type declaration for the record, + -- to be used as the designated type of the anonymous access. This is + -- done only once, and only if there is no previous partial view of the + -- type. + + ---------------------------------- + -- Check_Anonymous_Access_Types -- + ---------------------------------- + + procedure Check_Anonymous_Access_Types (Comp_List : Node_Id) is + Anon_Access : Entity_Id; + Acc_Def : Node_Id; + Comp : Node_Id; + Decl : Node_Id; + Type_Def : Node_Id; + + function Mentions_T (Acc_Def : Node_Id) return Boolean; + -- Check whether an access definition includes a reference to + -- the enclosing record type. The reference can be a subtype + -- mark in the access definition itself, or a 'Class attribute + -- reference, or recursively a reference appearing in a parameter + -- type in an access_to_subprogram definition. + + ---------------- + -- Mentions_T -- + ---------------- + + function Mentions_T (Acc_Def : Node_Id) return Boolean is + Subt : Node_Id; + + begin + if No (Access_To_Subprogram_Definition (Acc_Def)) then + Subt := Subtype_Mark (Acc_Def); + + if Nkind (Subt) = N_Identifier then + return Chars (Subt) = Chars (T); + + -- A reference to the current type may appear as the prefix + -- of a 'Class attribute. + + elsif Nkind (Subt) = N_Attribute_Reference + and then Attribute_Name (Subt) = Name_Class + and then Is_Entity_Name (Prefix (Subt)) + then + return (Chars (Prefix (Subt))) = Chars (T); + else + return False; + end if; + + else + -- Component is an access_to_subprogram: examine its formals + + declare + Param_Spec : Node_Id; + + begin + Param_Spec := + First + (Parameter_Specifications + (Access_To_Subprogram_Definition (Acc_Def))); + while Present (Param_Spec) loop + if Nkind (Parameter_Type (Param_Spec)) + = N_Access_Definition + and then Mentions_T (Parameter_Type (Param_Spec)) + then + return True; + end if; + + Next (Param_Spec); + end loop; + + return False; + end; + end if; + end Mentions_T; + + -- Start of processing for Check_Anonymous_Access_Types + + begin + if No (Comp_List) then + return; + end if; + + Comp := First (Component_Items (Comp_List)); + while Present (Comp) loop + if Nkind (Comp) = N_Component_Declaration + and then + Present (Access_Definition (Component_Definition (Comp))) + and then + Mentions_T (Access_Definition (Component_Definition (Comp))) + then + Acc_Def := + Access_To_Subprogram_Definition + (Access_Definition (Component_Definition (Comp))); + + Make_Incomplete_Type_Declaration; + Anon_Access := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('S')); + + -- Create a declaration for the anonymous access type: either + -- an access_to_object or an access_to_subprogram. + + if Present (Acc_Def) then + if Nkind (Acc_Def) = N_Access_Function_Definition then + Type_Def := + Make_Access_Function_Definition (Loc, + Parameter_Specifications => + Parameter_Specifications (Acc_Def), + Result_Definition => Result_Definition (Acc_Def)); + else + Type_Def := + Make_Access_Procedure_Definition (Loc, + Parameter_Specifications => + Parameter_Specifications (Acc_Def)); + end if; + + else + Type_Def := + Make_Access_To_Object_Definition (Loc, + Subtype_Indication => + Relocate_Node + (Subtype_Mark + (Access_Definition + (Component_Definition (Comp))))); + end if; + + Decl := Make_Full_Type_Declaration (Loc, + Defining_Identifier => Anon_Access, + Type_Definition => Type_Def); + + Insert_Before (N, Decl); + Analyze (Decl); + + Rewrite (Component_Definition (Comp), + Make_Component_Definition (Loc, + Subtype_Indication => + New_Occurrence_Of (Anon_Access, Loc))); + Set_Ekind (Anon_Access, E_Anonymous_Access_Type); + Set_Is_Local_Anonymous_Access (Anon_Access); + end if; + + Next (Comp); + end loop; + + if Present (Variant_Part (Comp_List)) then + declare + V : Node_Id; + begin + V := First_Non_Pragma (Variants (Variant_Part (Comp_List))); + while Present (V) loop + Check_Anonymous_Access_Types (Component_List (V)); + Next_Non_Pragma (V); + end loop; + end; + end if; + end Check_Anonymous_Access_Types; + + -------------------------------------- + -- Make_Incomplete_Type_Declaration -- + -------------------------------------- + + procedure Make_Incomplete_Type_Declaration is + Decl : Node_Id; + H : Entity_Id; + + begin + -- If there is a previous partial view, no need to create a new one + -- If the partial view is incomplete, it is given by Prev. If it is + -- a private declaration, full declaration is flagged accordingly. + + if Prev /= T + or else Has_Private_Declaration (T) + then + return; + + elsif No (Inc_T) then + Inc_T := Make_Defining_Identifier (Loc, Chars (T)); + Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T); + + -- Type has already been inserted into the current scope. + -- Remove it, and add incomplete declaration for type, so + -- that subsequent anonymous access types can use it. + + H := Current_Entity (T); + + if H = T then + Set_Name_Entity_Id (Chars (T), Empty); + else + while Present (H) + and then Homonym (H) /= T + loop + H := Homonym (T); + end loop; + + Set_Homonym (H, Homonym (T)); + end if; + + Insert_Before (N, Decl); + Analyze (Decl); + Set_Full_View (Inc_T, T); + + if Tagged_Present (Def) then + Make_Class_Wide_Type (Inc_T); + Set_Class_Wide_Type (T, Class_Wide_Type (Inc_T)); + Set_Etype (Class_Wide_Type (T), T); + end if; + end if; + end Make_Incomplete_Type_Declaration; + + -- Start of processing for Record_Type_Declaration + + begin + -- These flags must be initialized before calling Process_Discriminants + -- because this routine makes use of them. + + Set_Ekind (T, E_Record_Type); + Set_Etype (T, T); + Init_Size_Align (T); + Set_Abstract_Interfaces (T, No_Elist); + Set_Stored_Constraint (T, No_Elist); + + -- Normal case + + if Ada_Version < Ada_05 + or else not Interface_Present (Def) + then + -- The flag Is_Tagged_Type might have already been set by + -- Find_Type_Name if it detected an error for declaration T. This + -- arises in the case of private tagged types where the full view + -- omits the word tagged. + + Is_Tagged := + Tagged_Present (Def) + or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T)); + + Set_Is_Tagged_Type (T, Is_Tagged); + Set_Is_Limited_Record (T, Limited_Present (Def)); + + -- Type is abstract if full declaration carries keyword, or if + -- previous partial view did. + + Set_Is_Abstract (T, Is_Abstract (T) + or else Abstract_Present (Def)); + + else + Is_Tagged := True; + Analyze_Interface_Declaration (T, Def); + end if; + + -- First pass: if there are self-referential access components, + -- create the required anonymous access type declarations, and if + -- need be an incomplete type declaration for T itself. + + Check_Anonymous_Access_Types (Component_List (Def)); + + if Ada_Version >= Ada_05 + and then Present (Interface_List (Def)) + then + declare + Iface : Node_Id; + Iface_Def : Node_Id; + Iface_Typ : Entity_Id; + + begin + Iface := First (Interface_List (Def)); + while Present (Iface) loop + Iface_Typ := Find_Type_Of_Subtype_Indic (Iface); + Iface_Def := Type_Definition (Parent (Iface_Typ)); + + if not Is_Interface (Iface_Typ) then + Error_Msg_NE ("(Ada 2005) & must be an interface", + Iface, Iface_Typ); + + else + -- "The declaration of a specific descendant of an + -- interface type freezes the interface type" RM 13.14 + + Freeze_Before (N, Iface_Typ); + + -- Ada 2005 (AI-345): Protected interfaces can only + -- inherit from limited, synchronized or protected + -- interfaces. + + if Protected_Present (Def) then + if Limited_Present (Iface_Def) + or else Synchronized_Present (Iface_Def) + or else Protected_Present (Iface_Def) + then + null; + + elsif Task_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) protected interface cannot" + & " inherit from task interface", Iface); + + else + Error_Msg_N ("(Ada 2005) protected interface cannot" + & " inherit from non-limited interface", Iface); + end if; + + -- Ada 2005 (AI-345): Synchronized interfaces can only + -- inherit from limited and synchronized. + + elsif Synchronized_Present (Def) then + if Limited_Present (Iface_Def) + or else Synchronized_Present (Iface_Def) + then + null; + + elsif Protected_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) synchronized interface " & + "cannot inherit from protected interface", Iface); + + elsif Task_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) synchronized interface " & + "cannot inherit from task interface", Iface); + + else + Error_Msg_N ("(Ada 2005) synchronized interface " & + "cannot inherit from non-limited interface", + Iface); + end if; + + -- Ada 2005 (AI-345): Task interfaces can only inherit + -- from limited, synchronized or task interfaces. + + elsif Task_Present (Def) then + if Limited_Present (Iface_Def) + or else Synchronized_Present (Iface_Def) + or else Task_Present (Iface_Def) + then + null; + + elsif Protected_Present (Iface_Def) then + Error_Msg_N ("(Ada 2005) task interface cannot" & + " inherit from protected interface", Iface); + + else + Error_Msg_N ("(Ada 2005) task interface cannot" & + " inherit from non-limited interface", Iface); + end if; + end if; + end if; + + Next (Iface); + end loop; + Set_Abstract_Interfaces (T, New_Elmt_List); + Collect_Interfaces (Def, T); + end; + end if; + + -- Records constitute a scope for the component declarations within. + -- The scope is created prior to the processing of these declarations. + -- Discriminants are processed first, so that they are visible when + -- processing the other components. The Ekind of the record type itself + -- is set to E_Record_Type (subtypes appear as E_Record_Subtype). + + -- Enter record scope + + New_Scope (T); + + -- If an incomplete or private type declaration was already given for + -- the type, then this scope already exists, and the discriminants have + -- been declared within. We must verify that the full declaration + -- matches the incomplete one. + + Check_Or_Process_Discriminants (N, T, Prev); + + Set_Is_Constrained (T, not Has_Discriminants (T)); + Set_Has_Delayed_Freeze (T, True); + + -- For tagged types add a manually analyzed component corresponding + -- to the component _tag, the corresponding piece of tree will be + -- expanded as part of the freezing actions if it is not a CPP_Class. + + if Is_Tagged then + + -- Do not add the tag unless we are in expansion mode + + if Expander_Active then + Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag); + Enter_Name (Tag_Comp); + + Set_Is_Tag (Tag_Comp); + Set_Is_Aliased (Tag_Comp); + Set_Ekind (Tag_Comp, E_Component); + Set_Etype (Tag_Comp, RTE (RE_Tag)); + Set_DT_Entry_Count (Tag_Comp, No_Uint); + Set_Original_Record_Component (Tag_Comp, Tag_Comp); + Init_Component_Location (Tag_Comp); + + -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the + -- implemented interfaces + + Add_Interface_Tag_Components (N, T); + end if; + + Make_Class_Wide_Type (T); + Set_Primitive_Operations (T, New_Elmt_List); + end if; + + -- We must suppress range checks when processing the components + -- of a record in the presence of discriminants, since we don't + -- want spurious checks to be generated during their analysis, but + -- must reset the Suppress_Range_Checks flags after having processed + -- the record definition. + + if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then + Set_Kill_Range_Checks (T, True); + Record_Type_Definition (Def, Prev); + Set_Kill_Range_Checks (T, False); + else + Record_Type_Definition (Def, Prev); + end if; + + -- Exit from record scope + + End_Scope; + + if Expander_Active + and then Is_Tagged + and then not Is_Empty_List (Interface_List (Def)) + then + -- Ada 2005 (AI-251): Derive the interface subprograms of all the + -- implemented interfaces and check if some of the subprograms + -- inherited from the ancestor cover some interface subprogram. + + Derive_Interface_Subprograms (T); + end if; + end Record_Type_Declaration; + + ---------------------------- + -- Record_Type_Definition -- + ---------------------------- + + procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is + Component : Entity_Id; + Ctrl_Components : Boolean := False; + Final_Storage_Only : Boolean; + T : Entity_Id; + + begin + if Ekind (Prev_T) = E_Incomplete_Type then + T := Full_View (Prev_T); + else + T := Prev_T; + end if; + + Final_Storage_Only := not Is_Controlled (T); + + -- Ada 2005: check whether an explicit Limited is present in a derived + -- type declaration. + + if Nkind (Parent (Def)) = N_Derived_Type_Definition + and then Limited_Present (Parent (Def)) + then + Set_Is_Limited_Record (T); + end if; + + -- If the component list of a record type is defined by the reserved + -- word null and there is no discriminant part, then the record type has + -- no components and all records of the type are null records (RM 3.7) + -- This procedure is also called to process the extension part of a + -- record extension, in which case the current scope may have inherited + -- components. + + if No (Def) + or else No (Component_List (Def)) + or else Null_Present (Component_List (Def)) + then + null; + + else + Analyze_Declarations (Component_Items (Component_List (Def))); + + if Present (Variant_Part (Component_List (Def))) then + Analyze (Variant_Part (Component_List (Def))); + end if; + end if; + + -- After completing the semantic analysis of the record definition, + -- record components, both new and inherited, are accessible. Set + -- their kind accordingly. + + Component := First_Entity (Current_Scope); + while Present (Component) loop + if Ekind (Component) = E_Void then + Set_Ekind (Component, E_Component); + Init_Component_Location (Component); + end if; + + if Has_Task (Etype (Component)) then + Set_Has_Task (T); + end if; + + if Ekind (Component) /= E_Component then + null; + + elsif Has_Controlled_Component (Etype (Component)) + or else (Chars (Component) /= Name_uParent + and then Is_Controlled (Etype (Component))) + then + Set_Has_Controlled_Component (T, True); + Final_Storage_Only := Final_Storage_Only + and then Finalize_Storage_Only (Etype (Component)); + Ctrl_Components := True; + end if; + + Next_Entity (Component); + end loop; + + -- A type is Finalize_Storage_Only only if all its controlled + -- components are so. + + if Ctrl_Components then + Set_Finalize_Storage_Only (T, Final_Storage_Only); + end if; + + -- Place reference to end record on the proper entity, which may + -- be a partial view. + + if Present (Def) then + Process_End_Label (Def, 'e', Prev_T); + end if; + end Record_Type_Definition; + + ------------------------ + -- Replace_Components -- + ------------------------ + + procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is + function Process (N : Node_Id) return Traverse_Result; + + ------------- + -- Process -- + ------------- + + function Process (N : Node_Id) return Traverse_Result is + Comp : Entity_Id; + + begin + if Nkind (N) = N_Discriminant_Specification then + Comp := First_Discriminant (Typ); + while Present (Comp) loop + if Chars (Comp) = Chars (Defining_Identifier (N)) then + Set_Defining_Identifier (N, Comp); + exit; + end if; + + Next_Discriminant (Comp); + end loop; + + elsif Nkind (N) = N_Component_Declaration then + Comp := First_Component (Typ); + while Present (Comp) loop + if Chars (Comp) = Chars (Defining_Identifier (N)) then + Set_Defining_Identifier (N, Comp); + exit; + end if; + + Next_Component (Comp); + end loop; + end if; + + return OK; + end Process; + + procedure Replace is new Traverse_Proc (Process); + + -- Start of processing for Replace_Components + + begin + Replace (Decl); + end Replace_Components; + + ------------------------------- + -- Set_Completion_Referenced -- + ------------------------------- + + procedure Set_Completion_Referenced (E : Entity_Id) is + begin + -- If in main unit, mark entity that is a completion as referenced, + -- warnings go on the partial view when needed. + + if In_Extended_Main_Source_Unit (E) then + Set_Referenced (E); + end if; + end Set_Completion_Referenced; + + --------------------- + -- Set_Fixed_Range -- + --------------------- + + -- The range for fixed-point types is complicated by the fact that we + -- do not know the exact end points at the time of the declaration. This + -- is true for three reasons: + + -- A size clause may affect the fudging of the end-points + -- A small clause may affect the values of the end-points + -- We try to include the end-points if it does not affect the size + + -- This means that the actual end-points must be established at the point + -- when the type is frozen. Meanwhile, we first narrow the range as + -- permitted (so that it will fit if necessary in a small specified size), + -- and then build a range subtree with these narrowed bounds. + + -- Set_Fixed_Range constructs the range from real literal values, and sets + -- the range as the Scalar_Range of the given fixed-point type entity. + + -- The parent of this range is set to point to the entity so that it is + -- properly hooked into the tree (unlike normal Scalar_Range entries for + -- other scalar types, which are just pointers to the range in the + -- original tree, this would otherwise be an orphan). + + -- The tree is left unanalyzed. When the type is frozen, the processing + -- in Freeze.Freeze_Fixed_Point_Type notices that the range is not + -- analyzed, and uses this as an indication that it should complete + -- work on the range (it will know the final small and size values). + + procedure Set_Fixed_Range + (E : Entity_Id; + Loc : Source_Ptr; + Lo : Ureal; + Hi : Ureal) + is + S : constant Node_Id := + Make_Range (Loc, + Low_Bound => Make_Real_Literal (Loc, Lo), + High_Bound => Make_Real_Literal (Loc, Hi)); + + begin + Set_Scalar_Range (E, S); + Set_Parent (S, E); + end Set_Fixed_Range; + + ---------------------------------- + -- Set_Scalar_Range_For_Subtype -- + ---------------------------------- + + procedure Set_Scalar_Range_For_Subtype + (Def_Id : Entity_Id; + R : Node_Id; + Subt : Entity_Id) + is + Kind : constant Entity_Kind := Ekind (Def_Id); + + begin + Set_Scalar_Range (Def_Id, R); + + -- We need to link the range into the tree before resolving it so + -- that types that are referenced, including importantly the subtype + -- itself, are properly frozen (Freeze_Expression requires that the + -- expression be properly linked into the tree). Of course if it is + -- already linked in, then we do not disturb the current link. + + if No (Parent (R)) then + Set_Parent (R, Def_Id); + end if; + + -- Reset the kind of the subtype during analysis of the range, to + -- catch possible premature use in the bounds themselves. + + Set_Ekind (Def_Id, E_Void); + Process_Range_Expr_In_Decl (R, Subt); + Set_Ekind (Def_Id, Kind); + + end Set_Scalar_Range_For_Subtype; + + -------------------------------------------------------- + -- Set_Stored_Constraint_From_Discriminant_Constraint -- + -------------------------------------------------------- + + procedure Set_Stored_Constraint_From_Discriminant_Constraint + (E : Entity_Id) + is + begin + -- Make sure set if encountered during Expand_To_Stored_Constraint + + Set_Stored_Constraint (E, No_Elist); + + -- Give it the right value + + if Is_Constrained (E) and then Has_Discriminants (E) then + Set_Stored_Constraint (E, + Expand_To_Stored_Constraint (E, Discriminant_Constraint (E))); + end if; + end Set_Stored_Constraint_From_Discriminant_Constraint; + + ------------------------------------- + -- Signed_Integer_Type_Declaration -- + ------------------------------------- + + procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is + Implicit_Base : Entity_Id; + Base_Typ : Entity_Id; + Lo_Val : Uint; + Hi_Val : Uint; + Errs : Boolean := False; + Lo : Node_Id; + Hi : Node_Id; + + function Can_Derive_From (E : Entity_Id) return Boolean; + -- Determine whether given bounds allow derivation from specified type + + procedure Check_Bound (Expr : Node_Id); + -- Check bound to make sure it is integral and static. If not, post + -- appropriate error message and set Errs flag + + --------------------- + -- Can_Derive_From -- + --------------------- + + -- Note we check both bounds against both end values, to deal with + -- strange types like ones with a range of 0 .. -12341234. + + function Can_Derive_From (E : Entity_Id) return Boolean is + Lo : constant Uint := Expr_Value (Type_Low_Bound (E)); + Hi : constant Uint := Expr_Value (Type_High_Bound (E)); + begin + return Lo <= Lo_Val and then Lo_Val <= Hi + and then + Lo <= Hi_Val and then Hi_Val <= Hi; + end Can_Derive_From; + + ----------------- + -- Check_Bound -- + ----------------- + + procedure Check_Bound (Expr : Node_Id) is + begin + -- If a range constraint is used as an integer type definition, each + -- bound of the range must be defined by a static expression of some + -- integer type, but the two bounds need not have the same integer + -- type (Negative bounds are allowed.) (RM 3.5.4) + + if not Is_Integer_Type (Etype (Expr)) then + Error_Msg_N + ("integer type definition bounds must be of integer type", Expr); + Errs := True; + + elsif not Is_OK_Static_Expression (Expr) then + Flag_Non_Static_Expr + ("non-static expression used for integer type bound!", Expr); + Errs := True; + + -- The bounds are folded into literals, and we set their type to be + -- universal, to avoid typing difficulties: we cannot set the type + -- of the literal to the new type, because this would be a forward + -- reference for the back end, and if the original type is user- + -- defined this can lead to spurious semantic errors (e.g. 2928-003). + + else + if Is_Entity_Name (Expr) then + Fold_Uint (Expr, Expr_Value (Expr), True); + end if; + + Set_Etype (Expr, Universal_Integer); + end if; + end Check_Bound; + + -- Start of processing for Signed_Integer_Type_Declaration + + begin + -- Create an anonymous base type + + Implicit_Base := + Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B'); + + -- Analyze and check the bounds, they can be of any integer type + + Lo := Low_Bound (Def); + Hi := High_Bound (Def); + + -- Arbitrarily use Integer as the type if either bound had an error + + if Hi = Error or else Lo = Error then + Base_Typ := Any_Integer; + Set_Error_Posted (T, True); + + -- Here both bounds are OK expressions + + else + Analyze_And_Resolve (Lo, Any_Integer); + Analyze_And_Resolve (Hi, Any_Integer); + + Check_Bound (Lo); + Check_Bound (Hi); + + if Errs then + Hi := Type_High_Bound (Standard_Long_Long_Integer); + Lo := Type_Low_Bound (Standard_Long_Long_Integer); + end if; + + -- Find type to derive from + + Lo_Val := Expr_Value (Lo); + Hi_Val := Expr_Value (Hi); + + if Can_Derive_From (Standard_Short_Short_Integer) then + Base_Typ := Base_Type (Standard_Short_Short_Integer); + + elsif Can_Derive_From (Standard_Short_Integer) then + Base_Typ := Base_Type (Standard_Short_Integer); + + elsif Can_Derive_From (Standard_Integer) then + Base_Typ := Base_Type (Standard_Integer); + + elsif Can_Derive_From (Standard_Long_Integer) then + Base_Typ := Base_Type (Standard_Long_Integer); + + elsif Can_Derive_From (Standard_Long_Long_Integer) then + Base_Typ := Base_Type (Standard_Long_Long_Integer); + + else + Base_Typ := Base_Type (Standard_Long_Long_Integer); + Error_Msg_N ("integer type definition bounds out of range", Def); + Hi := Type_High_Bound (Standard_Long_Long_Integer); + Lo := Type_Low_Bound (Standard_Long_Long_Integer); + end if; + end if; + + -- Complete both implicit base and declared first subtype entities + + Set_Etype (Implicit_Base, Base_Typ); + Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ)); + Set_Size_Info (Implicit_Base, (Base_Typ)); + Set_RM_Size (Implicit_Base, RM_Size (Base_Typ)); + Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ)); + + Set_Ekind (T, E_Signed_Integer_Subtype); + Set_Etype (T, Implicit_Base); + + Set_Size_Info (T, (Implicit_Base)); + Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base)); + Set_Scalar_Range (T, Def); + Set_RM_Size (T, UI_From_Int (Minimum_Size (T))); + Set_Is_Constrained (T); + end Signed_Integer_Type_Declaration; + +end Sem_Ch3; |