------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 3 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2005, 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, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, 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 Tbuild; use Tbuild; with Ttypes; use Ttypes; with Uintp; use Uintp; with Urealp; use Urealp; package body Sem_Ch3 is ----------------------- -- Local Subprograms -- ----------------------- 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 to 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). 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 (Compon_Type : 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 the type of a component of Typ, 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 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. function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id; -- Given a subtype indication S (which is really an N_Subtype_Indication -- node or a plain N_Identifier), find the type of the subtype mark. 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 (ie 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 : constant Entity_Id := Create_Itype (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Scope (Current_Scope)); 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 (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 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, -- it 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; 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; Desig_Type : constant Entity_Id := Create_Itype (E_Subprogram_Type, Parent (T_Def)); begin if Nkind (T_Def) = N_Access_Function_Definition then Analyze (Subtype_Mark (T_Def)); Set_Etype (Desig_Type, Entity (Subtype_Mark (T_Def))); if not (Is_Type (Etype (Desig_Type))) then Error_Msg_N ("expect type in function specification", Subtype_Mark (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); 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) 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; ----------------------------------- -- 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). ------------------ -- 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 := First (Constraints (Constr)); begin while Present (IDC) loop -- One per-object constraint is sufficent 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; -- 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))); -- 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 (T, Current_Scope); -- Ada 2005 (AI-230) -- 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 handle -- properly 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)); 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 (Null_Exclusion_Present (Component_Definition (N)) or else Can_Never_Be_Null (T)) then Set_Can_Never_Be_Null (Id); 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_Limited_Record (Root_Type (Current_Scope)) then Error_Msg_N ("extension of nonlimited type cannot have limited components", N); 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) 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); 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_Itype_Reference -- ----------------------------- -- Nothing to do. This node is placed in the tree only for the benefit -- of Gigi 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 -- worthile 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 (Null_Exclusion_Present (N) or else Can_Never_Be_Null (T)) then Set_Can_Never_Be_Null (Id); Null_Exclusion_Static_Checks (N); 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 (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 if Has_Interrupt_Handler (T) 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 not Present (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 Act_T := Build_Default_Subtype; Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc)); elsif not Is_Constrained (T) and then Has_Discriminants (T) and then Constant_Present (N) and then Nkind (E) = N_Function_Call 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 a -- 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 about, it is 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 -- don't try to add a warning since we do not have access -- 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 (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 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 (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); 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)); -- 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)); -- Ada 2005 (AI-231): Propagate the null-excluding attribute -- and carry out some static checks if Null_Exclusion_Present (N) or else Can_Never_Be_Null (T) then Set_Can_Never_Be_Null (Id); if Null_Exclusion_Present (N) and then Can_Never_Be_Null (T) then Error_Msg_N ("(Ada 2005) null exclusion not allowed if parent " & "is already non-null", Subtype_Indication (N)); end if; end if; -- 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)); 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)); -- 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)); -- 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 to ensure that objects of this type are initialized. if Ada_Version >= Ada_05 and then (Null_Exclusion_Present (Component_Definition (Def)) or else 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) 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 := Parent (N); 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 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 rewriten 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 the parent type is not a derived type itself, and is -- declared in a closed scope (e.g., a subprogram), then we -- need to 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 (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 -- the old ones. Old_Disc := First_Discriminant (Parent_Type); New_Disc := First_Discriminant (Derived_Type); Disc_Spec := First (Discriminant_Specifications (N)); D_Constraint := First (Constraints (Constraint (Subtype_Indication (Type_Definition (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 overriden 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); 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 Build_Derived_Record_Type (Full_Decl, Parent_Type, Full_Der, False); 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; Inherit_Discrims : Boolean := False; 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; if 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; -- 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. Set_Is_Tagged_Type (Derived_Type, Is_Tagged); Set_Is_Limited_Record (Derived_Type, Is_Limited_Record (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 not Present (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); -- 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)); 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; 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); -- 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 Derive_Subprograms (Parent_Type, Derived_Type); 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 := First_Rep_Item (Derived_Type); Found : Boolean := False; begin 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_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 Set_Primitive_Operations (Def_Id, Primitive_Operations (T)); 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; 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); -- Special exception, do not complain about failure to override the -- stream routines _Input and _Output, since we always provide -- automatic overridings for these subprograms. if Is_Abstract (Subp) and then not Is_TSS (Subp, TSS_Stream_Input) and then not Is_TSS (Subp, TSS_Stream_Output) and then not Is_Abstract (T) 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). Type_Def := Type_Definition (Parent (T)); if Nkind (Type_Def) = N_Derived_Type_Definition and then Present (Record_Extension_Part (Type_Def)) then Error_Msg_NE ("type must be declared abstract or & 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). 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 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 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 (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 := First_Discriminant (T); Prev : Entity_Id; begin 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; ------------------------------ -- 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 neverthess 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; ---------------------------- -- 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_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_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 elsif Base_Type (Etype (Prev)) /= Base_Type (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 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; 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). 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 unconstrained 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); 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))); 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 (Compon_Type : 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); 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 := First_Discriminant (Typ); E : Elmt_Id := First_Elmt (Constraints); 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. 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 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); end if; return Compon_Type; 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 value 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 (Etype (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 -- 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)); -- 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 Old_C := First_Discriminant (Typ); while Present (Old_C) loop New_C := Create_Component (Old_C); Set_Is_Public (New_C, Is_Public (Subt)); Next_Discriminant (Old_C); end loop; 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 the discriminants are not static, or if this is a multi-level -- type extension, we have to include all the 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 (Etype (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 := Delta_Val; begin Scale_Val := Uint_0; 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_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 overriden 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 := Homonym (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) 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; -- 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) is Op_List : constant Elist_Id := Collect_Primitive_Operations (Parent_Type); Act_List : Elist_Id; Act_Elmt : Elmt_Id; Elmt : Elmt_Id; 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 if 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); 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; begin Parent_Type := Find_Type_Of_Subtype_Indic (Indic); 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; -- Ada 2005 (AI-231): Static check elsif Is_Access_Type (Parent_Type) and then Null_Exclusion_Present (Type_Definition (N)) and then Can_Never_Be_Null (Parent_Type) then Error_Msg_N ("(Ada 2005) null exclusion not allowed if parent is " & "already non-null", Type_Definition (N)); 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 Is_Generic_Type (Parent_Type) and then not Is_Generic_Type (Root_Type (Parent_Type)) and then not Is_Generic_Actual_Type (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 people looking at 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); 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); end if; 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))) 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; 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 := First_Discriminant (Typ_For_Constraint); E : Elmt_Id := First_Elmt (Constraint); begin 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 := First_Discriminant (Typ_For_Constraint); E : Elmt_Id := First_Elmt (Constraint); begin 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 (Etype (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_Discrimm 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 if 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_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 := Scope (Typ); begin 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 := Ureal_1; Scale : Int := 0; begin 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 (N, Discriminant_Type (Discr)); -- 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): Set the null-excluding attribute and carry -- out some static checks. if Ada_Version >= Ada_05 and then (Null_Exclusion_Present (Discr) or else Can_Never_Be_Null (Discr_Type)) then Set_Can_Never_Be_Null (Defining_Identifier (Discr)); Null_Exclusion_Static_Checks (Discr); 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; 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 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; elsif 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 not Present (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; -- 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 ot 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; else Inc_Elmt := First_Elmt (Private_Dependents (Inc_T)); -- 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. end if; 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 if Is_Tagged_Type (Full_T) 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); Type_Decl := Parent (R); -- 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 ??? 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 := Parent (R); begin 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; Full_View_Id : Entity_Id; Subtype_Mark_Id : Entity_Id; 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); -- Ada 2005 (AI-231): Static check if Ada_Version >= Ada_05 and then Present (Parent (S)) and then Null_Exclusion_Present (Parent (S)) and then Nkind (Parent (S)) /= N_Access_To_Object_Definition and then not Is_Access_Type (Entity (S)) then Error_Msg_N ("(Ada 2005) null-exclusion part requires an access type", 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 Def : constant Node_Id := Type_Definition (N); Is_Tagged : Boolean; Tag_Comp : Entity_Id; begin -- 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)); -- 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); -- These flags must be initialized before calling Process_Discriminants -- because this routine makes use of them. 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)); Set_Ekind (T, E_Record_Type); Set_Etype (T, T); Init_Size_Align (T); Set_Stored_Constraint (T, No_Elist); -- 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_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); 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; 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); -- 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;