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+------------------------------------------------------------------------------
+-- --
+-- GNAT COMPILER COMPONENTS --
+-- --
+-- S E M _ C H 3 --
+-- --
+-- B o d y --
+-- --
+-- Copyright (C) 1992-2013, 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 3, 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 COPYING3. If not, go to --
+-- http://www.gnu.org/licenses for a complete copy of the license. --
+-- --
+-- GNAT was originally developed by the GNAT team at New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc. --
+-- --
+------------------------------------------------------------------------------
+
+with Aspects; use Aspects;
+with Atree; use Atree;
+with Checks; use Checks;
+with Debug; use Debug;
+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_Ch9; use Exp_Ch9;
+with Exp_Disp; use Exp_Disp;
+with Exp_Dist; use Exp_Dist;
+with Exp_Tss; use Exp_Tss;
+with Exp_Util; use Exp_Util;
+with Fname; use Fname;
+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_Aux; use Sem_Aux;
+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_Dim; use Sem_Dim;
+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_Prag; use Sem_Prag;
+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 Sinput; use Sinput;
+with Snames; use Snames;
+with Targparm; use Targparm;
+with Tbuild; use Tbuild;
+with Ttypes; use Ttypes;
+with Uintp; use Uintp;
+with Urealp; use Urealp;
+
+package body Sem_Ch3 is
+
+ -----------------------
+ -- Local Subprograms --
+ -----------------------
+
+ procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id);
+ -- Ada 2005 (AI-251): Add the tag components corresponding to all the
+ -- abstract interface types implemented by a record type or a derived
+ -- record type.
+
+ procedure Build_Derived_Type
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id;
+ Is_Completion : Boolean;
+ Derive_Subps : Boolean := True);
+ -- Create and decorate a Derived_Type given the Parent_Type entity. N is
+ -- the N_Full_Type_Declaration node containing the derived type definition.
+ -- Parent_Type is the entity for the parent type in the derived type
+ -- definition and Derived_Type the actual derived type. Is_Completion must
+ -- be set to False if Derived_Type is the N_Defining_Identifier node in N
+ -- (i.e. 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
+ -- protected 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_]Wide_Character are special-cased.
+
+ procedure Build_Derived_Numeric_Type
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id);
+ -- Subsidiary procedure to Build_Derived_Type. For numeric types, create
+ -- an anonymous base type, and propagate constraint to subtype if needed.
+
+ procedure Build_Derived_Private_Type
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id;
+ Is_Completion : Boolean;
+ Derive_Subps : Boolean := True);
+ -- Subsidiary procedure to Build_Derived_Type. This procedure is complex
+ -- because the parent may or may not have a completion, and the derivation
+ -- may itself be a completion.
+
+ procedure Build_Derived_Record_Type
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id;
+ Derive_Subps : Boolean := True);
+ -- Subsidiary procedure for Build_Derived_Type and
+ -- Analyze_Private_Extension_Declaration used for tagged and untagged
+ -- record types. All parameters are as in Build_Derived_Type except that
+ -- N, in addition to being an N_Full_Type_Declaration node, can also be an
+ -- N_Private_Extension_Declaration node. See the definition of this routine
+ -- for much more info. Derive_Subps indicates whether subprograms should
+ -- be derived from the parent type. The only case where Derive_Subps is
+ -- False is for an implicit derived full type for a type derived from a
+ -- private type (see Build_Derived_Type).
+
+ procedure 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, where 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
+ -- when 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_Anonymous_Access_Components
+ (Typ_Decl : Node_Id;
+ Typ : Entity_Id;
+ Prev : Entity_Id;
+ Comp_List : Node_Id);
+ -- Ada 2005 AI-382: an access component in a record definition can refer to
+ -- the enclosing record, in which case it denotes the type itself, and not
+ -- the current instance of the type. We create an anonymous access type for
+ -- the component, and flag it as an access to a component, so accessibility
+ -- checks are properly performed on it. The declaration of the access type
+ -- is placed ahead of that of the record to prevent order-of-elaboration
+ -- circularity issues in Gigi. We create an incomplete type for the record
+ -- declaration, which is the designated type of the anonymous access.
+
+ 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_Interfaces (N : Node_Id; Def : Node_Id);
+ -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
+
+ procedure Check_Or_Process_Discriminants
+ (N : Node_Id;
+ T : Entity_Id;
+ Prev : Entity_Id := Empty);
+ -- If N is the full declaration of the completion T of an incomplete or
+ -- private type, check its discriminants (which are already known to be
+ -- conformant with those of the partial view, see Find_Type_Name),
+ -- 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.
+
+ function Contain_Interface
+ (Iface : Entity_Id;
+ Ifaces : Elist_Id) return Boolean;
+ -- Ada 2005: Determine whether Iface is present in the list Ifaces
+
+ procedure Convert_Scalar_Bounds
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id;
+ Loc : Source_Ptr);
+ -- For derived scalar types, convert the bounds in the type definition to
+ -- the derived type, and complete their analysis. Given a constraint of the
+ -- form ".. new T range Lo .. Hi", Lo and Hi are analyzed and resolved with
+ -- T'Base, the parent_type. The bounds of the derived type (the anonymous
+ -- base) are copies of Lo and Hi. Finally, the bounds of the derived
+ -- subtype are conversions of those bounds to the derived_type, so that
+ -- their typing is consistent.
+
+ procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
+ -- Copies attributes from array base type T2 to array base type T1. Copies
+ -- only attributes that apply to base types, but not subtypes.
+
+ procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
+ -- Copies attributes from array subtype T2 to array subtype T1. Copies
+ -- attributes that apply to both subtypes and base types.
+
+ procedure Create_Constrained_Components
+ (Subt : Entity_Id;
+ Decl_Node : Node_Id;
+ Typ : Entity_Id;
+ Constraints : Elist_Id);
+ -- Build the list of entities for a constrained discriminated record
+ -- subtype. If a component depends on a discriminant, replace its subtype
+ -- using the discriminant values in the discriminant constraint. Subt
+ -- is the defining identifier for the subtype whose list of constrained
+ -- entities we will create. Decl_Node is the type declaration node where
+ -- we will attach all the itypes created. Typ is the base discriminated
+ -- type for the subtype Subt. Constraints is the list of discriminant
+ -- constraints for Typ.
+
+ function Constrain_Component_Type
+ (Comp : Entity_Id;
+ Constrained_Typ : Entity_Id;
+ Related_Node : Node_Id;
+ Typ : Entity_Id;
+ Constraints : Elist_Id) return Entity_Id;
+ -- Given a discriminated base type Typ, a list of discriminant constraint
+ -- Constraints for Typ and a component of Typ, with type Compon_Type,
+ -- create and return the type corresponding to Compon_type where all
+ -- discriminant references are replaced with the corresponding constraint.
+ -- If no discriminant references occur in Compon_Typ then return it as is.
+ -- Constrained_Typ is the final constrained subtype to which the
+ -- constrained Compon_Type belongs. Related_Node is the node where we will
+ -- attach all the itypes created.
+ --
+ -- Above description is confused, what is Compon_Type???
+
+ 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 S in a constrained array declaration. The
+ -- constraint can be a subtype name, or a range with or without an explicit
+ -- subtype mark. The index is the corresponding index of the unconstrained
+ -- array. The Related_Id and Suffix parameters are used to build the
+ -- associated Implicit type name.
+
+ procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
+ -- Build subtype of a signed or modular integer type
+
+ procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
+ -- Constrain an ordinary fixed point type with a range constraint, and
+ -- build an E_Ordinary_Fixed_Point_Subtype entity.
+
+ procedure Copy_And_Swap (Priv, Full : Entity_Id);
+ -- Copy the Priv entity into the entity of its full declaration then swap
+ -- the two entities in such a manner that the former private type is now
+ -- seen as a full type.
+
+ procedure Decimal_Fixed_Point_Type_Declaration
+ (T : Entity_Id;
+ Def : Node_Id);
+ -- Create a new decimal fixed point type, and apply the constraint to
+ -- obtain a subtype of this new type.
+
+ procedure Complete_Private_Subtype
+ (Priv : Entity_Id;
+ Full : Entity_Id;
+ Full_Base : Entity_Id;
+ Related_Nod : Node_Id);
+ -- Complete the implicit full view of a private subtype by setting the
+ -- appropriate semantic fields. If the full view of the parent is a record
+ -- type, build constrained components of subtype.
+
+ procedure Derive_Progenitor_Subprograms
+ (Parent_Type : Entity_Id;
+ Tagged_Type : Entity_Id);
+ -- Ada 2005 (AI-251): To complete type derivation, collect the primitive
+ -- operations of progenitors of Tagged_Type, and replace the subsidiary
+ -- subtypes with Tagged_Type, to build the specs of the inherited interface
+ -- primitives. The derived primitives are aliased to those of the
+ -- interface. This routine takes care also of transferring to the full view
+ -- subprograms associated with the partial view of Tagged_Type that cover
+ -- interface primitives.
+
+ 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. Build_Derived_Type is invoked
+ -- to process the actual derived type definition. Parameters N and
+ -- Is_Completion have the same meaning as in Build_Derived_Type.
+ -- T is the N_Defining_Identifier for the entity defined in the
+ -- N_Full_Type_Declaration node N, that is T is the derived type.
+
+ procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
+ -- Insert each literal in symbol table, as an overloadable identifier. Each
+ -- enumeration type is mapped into a sequence of integers, and each literal
+ -- is defined as a constant with integer value. If any of the literals are
+ -- character literals, the type is a character type, which means that
+ -- strings are legal aggregates for arrays of components of the type.
+
+ function Expand_To_Stored_Constraint
+ (Typ : Entity_Id;
+ Constraint : Elist_Id) return Elist_Id;
+ -- Given a constraint (i.e. a list of expressions) on the discriminants of
+ -- Typ, expand it into a constraint on the stored discriminants and return
+ -- the new list of expressions constraining the stored discriminants.
+
+ function Find_Type_Of_Object
+ (Obj_Def : Node_Id;
+ Related_Nod : Node_Id) return Entity_Id;
+ -- Get type entity for object referenced by Obj_Def, attaching the
+ -- implicit types generated to Related_Nod
+
+ procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
+ -- Create a new float and apply the constraint to obtain subtype of it
+
+ function Has_Range_Constraint (N : Node_Id) return Boolean;
+ -- Given an N_Subtype_Indication node N, return True if a range constraint
+ -- is present, either directly, or as part of a digits or delta constraint.
+ -- In addition, a digits constraint in the decimal case returns True, since
+ -- it establishes a default range if no explicit range is present.
+
+ function 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.
+
+ 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
+
+ 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.
+
+ procedure Diagnose_Interface (N : Node_Id; E : Entity_Id);
+ -- Check that an entity in a list of progenitors is an interface,
+ -- emit error otherwise.
+
+ -----------------------
+ -- Access_Definition --
+ -----------------------
+
+ function Access_Definition
+ (Related_Nod : Node_Id;
+ N : Node_Id) return Entity_Id
+ is
+ Anon_Type : Entity_Id;
+ Anon_Scope : Entity_Id;
+ Desig_Type : Entity_Id;
+ Enclosing_Prot_Type : Entity_Id := Empty;
+
+ begin
+ Check_SPARK_Restriction ("access type is not allowed", N);
+
+ 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);
+ return Empty;
+ end if;
+
+ -- Ada 2005: for an object declaration the corresponding anonymous
+ -- type is declared in the current scope.
+
+ -- If the access definition is the return type of another access to
+ -- function, scope is the current one, because it is the one of the
+ -- current type declaration, except for the pathological case below.
+
+ if Nkind_In (Related_Nod, N_Object_Declaration,
+ N_Access_Function_Definition)
+ then
+ Anon_Scope := Current_Scope;
+
+ -- A pathological case: function returning access functions that
+ -- return access functions, etc. Each anonymous access type created
+ -- is in the enclosing scope of the outermost function.
+
+ declare
+ Par : Node_Id;
+
+ begin
+ Par := Related_Nod;
+ while Nkind_In (Par, N_Access_Function_Definition,
+ N_Access_Definition)
+ loop
+ Par := Parent (Par);
+ end loop;
+
+ if Nkind (Par) = N_Function_Specification then
+ Anon_Scope := Scope (Defining_Entity (Par));
+ end if;
+ end;
+
+ -- For the anonymous function result case, retrieve the scope of the
+ -- function specification's associated entity rather than using the
+ -- current scope. The current scope will be the function itself if the
+ -- formal part is currently being analyzed, but will be the parent scope
+ -- in the case of a parameterless function, and we always want to use
+ -- the function's parent scope. Finally, if the function is a child
+ -- unit, we must traverse the tree to retrieve the proper entity.
+
+ elsif Nkind (Related_Nod) = N_Function_Specification
+ and then Nkind (Parent (N)) /= N_Parameter_Specification
+ then
+ -- If the current scope is a protected type, the anonymous access
+ -- is associated with one of the protected operations, and must
+ -- be available in the scope that encloses the protected declaration.
+ -- Otherwise the type is in the scope enclosing the subprogram.
+
+ -- If the function has formals, The return type of a subprogram
+ -- declaration is analyzed in the scope of the subprogram (see
+ -- Process_Formals) and thus the protected type, if present, is
+ -- the scope of the current function scope.
+
+ if Ekind (Current_Scope) = E_Protected_Type then
+ Enclosing_Prot_Type := Current_Scope;
+
+ elsif Ekind (Current_Scope) = E_Function
+ and then Ekind (Scope (Current_Scope)) = E_Protected_Type
+ then
+ Enclosing_Prot_Type := Scope (Current_Scope);
+ end if;
+
+ if Present (Enclosing_Prot_Type) then
+ Anon_Scope := Scope (Enclosing_Prot_Type);
+
+ else
+ Anon_Scope := Scope (Defining_Entity (Related_Nod));
+ end if;
+
+ -- For an access type definition, if the current scope is a child
+ -- unit it is the scope of the type.
+
+ elsif Is_Compilation_Unit (Current_Scope) then
+ Anon_Scope := Current_Scope;
+
+ -- For access formals, access components, and access discriminants, the
+ -- scope is that of the enclosing declaration,
+
+ else
+ Anon_Scope := Scope (Current_Scope);
+ end if;
+
+ Anon_Type :=
+ Create_Itype
+ (E_Anonymous_Access_Type, Related_Nod, Scope_Id => Anon_Scope);
+
+ if All_Present (N)
+ and then Ada_Version >= Ada_2005
+ then
+ Error_Msg_N ("ALL is not permitted for anonymous access types", N);
+ end if;
+
+ -- Ada 2005 (AI-254): In case of anonymous access to subprograms call
+ -- the corresponding semantic routine
+
+ if Present (Access_To_Subprogram_Definition (N)) then
+
+ -- Compiler runtime units are compiled in Ada 2005 mode when building
+ -- the runtime library but must also be compilable in Ada 95 mode
+ -- (when bootstrapping the compiler).
+
+ Check_Compiler_Unit (N);
+
+ 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;
+
+ Set_Can_Use_Internal_Rep
+ (Anon_Type, not Always_Compatible_Rep_On_Target);
+
+ -- If the anonymous access is associated with a protected operation,
+ -- create a reference to it after the enclosing protected definition
+ -- because the itype will be used in the subsequent bodies.
+
+ if Ekind (Current_Scope) = E_Protected_Type then
+ Build_Itype_Reference (Anon_Type, Parent (Current_Scope));
+ 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);
+
+ -- Make sure the anonymous access type has size and alignment fields
+ -- set, as required by gigi. This is necessary in the case of the
+ -- Task_Body_Procedure.
+
+ if not Has_Private_Component (Desig_Type) then
+ Layout_Type (Anon_Type);
+ end if;
+
+ -- 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_2005 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-231): Propagate the access-constant attribute
+
+ Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
+
+ -- The context is either a subprogram declaration, object declaration,
+ -- or an access discriminant, in a private or a full type declaration.
+ -- In the case of a subprogram, if the designated type is incomplete,
+ -- the operation will be a primitive operation of the full type, to be
+ -- updated subsequently. If the type is imported through a limited_with
+ -- clause, the subprogram is not a primitive operation of the type
+ -- (which is declared elsewhere in some other scope).
+
+ if Ekind (Desig_Type) = E_Incomplete_Type
+ and then not From_With_Type (Desig_Type)
+ and then Is_Overloadable (Current_Scope)
+ then
+ Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
+ Set_Has_Delayed_Freeze (Current_Scope);
+ end if;
+
+ -- Ada 2005: if the designated type is an interface that may contain
+ -- tasks, create a Master entity for the declaration. This must be done
+ -- before expansion of the full declaration, because the declaration may
+ -- include an expression that is an allocator, whose expansion needs the
+ -- proper Master for the created tasks.
+
+ if Nkind (Related_Nod) = N_Object_Declaration
+ and then Expander_Active
+ then
+ if Is_Interface (Desig_Type)
+ and then Is_Limited_Record (Desig_Type)
+ then
+ Build_Class_Wide_Master (Anon_Type);
+
+ -- Similarly, if the type is an anonymous access that designates
+ -- tasks, create a master entity for it in the current context.
+
+ elsif Has_Task (Desig_Type)
+ and then Comes_From_Source (Related_Nod)
+ then
+ Build_Master_Entity (Defining_Identifier (Related_Nod));
+ Build_Master_Renaming (Anon_Type);
+ end if;
+ end if;
+
+ -- For a private component of a protected type, it is imperative that
+ -- the back-end elaborate the type immediately after the protected
+ -- declaration, because this type will be used in the declarations
+ -- created for the component within each protected body, so we must
+ -- create an itype reference for it now.
+
+ if Nkind (Parent (Related_Nod)) = N_Protected_Definition then
+ Build_Itype_Reference (Anon_Type, Parent (Parent (Related_Nod)));
+
+ -- Similarly, if the access definition is the return result of a
+ -- function, create an itype reference for it because it will be used
+ -- within the function body. For a regular function that is not a
+ -- compilation unit, insert reference after the declaration. For a
+ -- protected operation, insert it after the enclosing protected type
+ -- declaration. In either case, do not create a reference for a type
+ -- obtained through a limited_with clause, because this would introduce
+ -- semantic dependencies.
+
+ -- Similarly, do not create a reference if the designated type is a
+ -- generic formal, because no use of it will reach the backend.
+
+ elsif Nkind (Related_Nod) = N_Function_Specification
+ and then not From_With_Type (Desig_Type)
+ and then not Is_Generic_Type (Desig_Type)
+ then
+ if Present (Enclosing_Prot_Type) then
+ Build_Itype_Reference (Anon_Type, Parent (Enclosing_Prot_Type));
+
+ elsif Is_List_Member (Parent (Related_Nod))
+ and then Nkind (Parent (N)) /= N_Parameter_Specification
+ then
+ Build_Itype_Reference (Anon_Type, Parent (Related_Nod));
+ end if;
+
+ -- Finally, create an itype reference for an object declaration of an
+ -- anonymous access type. This is strictly necessary only for deferred
+ -- constants, but in any case will avoid out-of-scope problems in the
+ -- back-end.
+
+ elsif Nkind (Related_Nod) = N_Object_Declaration then
+ Build_Itype_Reference (Anon_Type, Related_Nod);
+ end if;
+
+ return Anon_Type;
+ end Access_Definition;
+
+ -----------------------------------
+ -- Access_Subprogram_Declaration --
+ -----------------------------------
+
+ procedure Access_Subprogram_Declaration
+ (T_Name : Entity_Id;
+ T_Def : Node_Id)
+ is
+
+ procedure Check_For_Premature_Usage (Def : Node_Id);
+ -- Check that type T_Name is not used, directly or recursively, as a
+ -- parameter or a return type in Def. Def is either a subtype, an
+ -- access_definition, or an access_to_subprogram_definition.
+
+ -------------------------------
+ -- Check_For_Premature_Usage --
+ -------------------------------
+
+ procedure Check_For_Premature_Usage (Def : Node_Id) is
+ Param : Node_Id;
+
+ begin
+ -- Check for a subtype mark
+
+ if Nkind (Def) in N_Has_Etype then
+ if Etype (Def) = T_Name then
+ Error_Msg_N
+ ("type& cannot be used before end of its declaration", Def);
+ end if;
+
+ -- If this is not a subtype, then this is an access_definition
+
+ elsif Nkind (Def) = N_Access_Definition then
+ if Present (Access_To_Subprogram_Definition (Def)) then
+ Check_For_Premature_Usage
+ (Access_To_Subprogram_Definition (Def));
+ else
+ Check_For_Premature_Usage (Subtype_Mark (Def));
+ end if;
+
+ -- The only cases left are N_Access_Function_Definition and
+ -- N_Access_Procedure_Definition.
+
+ else
+ if Present (Parameter_Specifications (Def)) then
+ Param := First (Parameter_Specifications (Def));
+ while Present (Param) loop
+ Check_For_Premature_Usage (Parameter_Type (Param));
+ Param := Next (Param);
+ end loop;
+ end if;
+
+ if Nkind (Def) = N_Access_Function_Definition then
+ Check_For_Premature_Usage (Result_Definition (Def));
+ end if;
+ end if;
+ end Check_For_Premature_Usage;
+
+ -- Local variables
+
+ Formals : constant List_Id := Parameter_Specifications (T_Def);
+ Formal : Entity_Id;
+ D_Ityp : Node_Id;
+ Desig_Type : constant Entity_Id :=
+ Create_Itype (E_Subprogram_Type, Parent (T_Def));
+
+ -- Start of processing for Access_Subprogram_Declaration
+
+ begin
+ Check_SPARK_Restriction ("access type is not allowed", T_Def);
+
+ -- Associate the Itype node with the inner full-type declaration or
+ -- subprogram spec or entry body. This is required to handle nested
+ -- anonymous declarations. For example:
+
+ -- procedure P
+ -- (X : access procedure
+ -- (Y : access procedure
+ -- (Z : access T)))
+
+ D_Ityp := Associated_Node_For_Itype (Desig_Type);
+ while not (Nkind_In (D_Ityp, N_Full_Type_Declaration,
+ N_Private_Type_Declaration,
+ N_Private_Extension_Declaration,
+ N_Procedure_Specification,
+ N_Function_Specification,
+ N_Entry_Body)
+
+ or else
+ Nkind_In (D_Ityp, N_Object_Declaration,
+ N_Object_Renaming_Declaration,
+ N_Formal_Object_Declaration,
+ N_Formal_Type_Declaration,
+ N_Task_Type_Declaration,
+ N_Protected_Type_Declaration))
+ loop
+ D_Ityp := Parent (D_Ityp);
+ pragma Assert (D_Ityp /= Empty);
+ end loop;
+
+ Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
+
+ if Nkind_In (D_Ityp, N_Procedure_Specification,
+ N_Function_Specification)
+ then
+ Set_Scope (Desig_Type, Scope (Defining_Entity (D_Ityp)));
+
+ elsif Nkind_In (D_Ityp, N_Full_Type_Declaration,
+ N_Object_Declaration,
+ N_Object_Renaming_Declaration,
+ N_Formal_Type_Declaration)
+ then
+ Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
+ end if;
+
+ if Nkind (T_Def) = N_Access_Function_Definition then
+ if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
+ declare
+ Acc : constant Node_Id := Result_Definition (T_Def);
+
+ begin
+ if Present (Access_To_Subprogram_Definition (Acc))
+ and then
+ Protected_Present (Access_To_Subprogram_Definition (Acc))
+ then
+ Set_Etype
+ (Desig_Type,
+ Replace_Anonymous_Access_To_Protected_Subprogram
+ (T_Def));
+
+ else
+ Set_Etype
+ (Desig_Type,
+ Access_Definition (T_Def, Result_Definition (T_Def)));
+ end if;
+ end;
+
+ else
+ Analyze (Result_Definition (T_Def));
+
+ declare
+ Typ : constant Entity_Id := Entity (Result_Definition (T_Def));
+
+ begin
+ -- If a null exclusion is imposed on the result type, then
+ -- create a null-excluding itype (an access subtype) and use
+ -- it as the function's Etype.
+
+ if Is_Access_Type (Typ)
+ and then Null_Exclusion_In_Return_Present (T_Def)
+ then
+ Set_Etype (Desig_Type,
+ Create_Null_Excluding_Itype
+ (T => Typ,
+ Related_Nod => T_Def,
+ Scope_Id => Current_Scope));
+
+ else
+ if From_With_Type (Typ) then
+
+ -- AI05-151: Incomplete types are allowed in all basic
+ -- declarations, including access to subprograms.
+
+ if Ada_Version >= Ada_2012 then
+ null;
+
+ else
+ Error_Msg_NE
+ ("illegal use of incomplete type&",
+ Result_Definition (T_Def), Typ);
+ end if;
+
+ elsif Ekind (Current_Scope) = E_Package
+ and then In_Private_Part (Current_Scope)
+ then
+ if Ekind (Typ) = E_Incomplete_Type then
+ Append_Elmt (Desig_Type, Private_Dependents (Typ));
+
+ elsif Is_Class_Wide_Type (Typ)
+ and then Ekind (Etype (Typ)) = E_Incomplete_Type
+ then
+ Append_Elmt
+ (Desig_Type, Private_Dependents (Etype (Typ)));
+ end if;
+ end if;
+
+ Set_Etype (Desig_Type, Typ);
+ end if;
+ end;
+ end if;
+
+ if not (Is_Type (Etype (Desig_Type))) then
+ Error_Msg_N
+ ("expect type in function specification",
+ Result_Definition (T_Def));
+ end if;
+
+ else
+ Set_Etype (Desig_Type, Standard_Void_Type);
+ end if;
+
+ if Present (Formals) then
+ Push_Scope (Desig_Type);
+
+ -- A bit of a kludge here. These kludges will be removed when Itypes
+ -- have proper parent pointers to their declarations???
+
+ -- Kludge 1) Link defining_identifier of formals. Required by
+ -- First_Formal to provide its functionality.
+
+ declare
+ F : Node_Id;
+
+ begin
+ F := First (Formals);
+
+ -- In ASIS mode, the access_to_subprogram may be analyzed twice,
+ -- when it is part of an unconstrained type and subtype expansion
+ -- is disabled. To avoid back-end problems with shared profiles,
+ -- use previous subprogram type as the designated type, and then
+ -- remove scope added above.
+
+ if ASIS_Mode
+ and then Present (Scope (Defining_Identifier (F)))
+ then
+ Set_Etype (T_Name, T_Name);
+ Init_Size_Align (T_Name);
+ Set_Directly_Designated_Type (T_Name,
+ Scope (Defining_Identifier (F)));
+ End_Scope;
+ return;
+ end if;
+
+ while Present (F) loop
+ if No (Parent (Defining_Identifier (F))) then
+ Set_Parent (Defining_Identifier (F), F);
+ end if;
+
+ Next (F);
+ end loop;
+ end;
+
+ Process_Formals (Formals, Parent (T_Def));
+
+ -- Kludge 2) 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 ???
+
+ Set_Parent (Desig_Type, T_Name);
+ End_Scope;
+ Set_Parent (Desig_Type, Empty);
+ end if;
+
+ -- Check for premature usage of the type being defined
+
+ Check_For_Premature_Usage (T_Def);
+
+ -- 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. This
+ -- only applies to incomplete types declared in some enclosing scope,
+ -- not to limited views from other packages.
+
+ 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
+ and then In_Open_Scopes (Scope (Etype (Formal)))
+ 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 the return type is incomplete, this is legal as long as the
+ -- type is declared in the current scope and will be completed in
+ -- it (rather than being part of limited view).
+
+ if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
+ and then not Has_Delayed_Freeze (Desig_Type)
+ and then In_Open_Scopes (Scope (Etype (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_Can_Use_Internal_Rep (T_Name, not Always_Compatible_Rep_On_Target);
+
+ 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
+ P : constant Node_Id := Parent (Def);
+ S : constant Node_Id := Subtype_Indication (Def);
+
+ Full_Desig : Entity_Id;
+
+ begin
+ Check_SPARK_Restriction ("access type is not allowed", Def);
+
+ -- 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;
+
+ Full_Desig := Designated_Type (T);
+
+ if Base_Type (Full_Desig) = T then
+ Error_Msg_N ("access type cannot designate itself", S);
+
+ -- In Ada 2005, the type may have a limited view through some unit
+ -- in its own context, allowing the following circularity that cannot
+ -- be detected earlier
+
+ elsif Is_Class_Wide_Type (Full_Desig)
+ and then Etype (Full_Desig) = T
+ then
+ Error_Msg_N
+ ("access type cannot designate its own classwide type", S);
+
+ -- Clean up indication of tagged status to prevent cascaded errors
+
+ Set_Is_Tagged_Type (T, False);
+ end if;
+
+ Set_Etype (T, T);
+
+ -- If the type has appeared already in a with_type clause, it is
+ -- frozen and the pointer size is already set. Else, initialize.
+
+ if not From_With_Type (T) then
+ Init_Size_Align (T);
+ end if;
+
+ -- 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);
+
+ -- Initialize field Finalization_Master explicitly to Empty, to avoid
+ -- problems where an incomplete view of this entity has been previously
+ -- established by a limited with and an overlaid version of this field
+ -- (Stored_Constraint) was initialized for the incomplete view.
+
+ -- This reset is performed in most cases except where the access type
+ -- has been created for the purposes of allocating or deallocating a
+ -- build-in-place object. Such access types have explicitly set pools
+ -- and finalization masters.
+
+ if No (Associated_Storage_Pool (T)) then
+ Set_Finalization_Master (T, Empty);
+ end if;
+
+ -- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
+ -- attributes
+
+ Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
+ Set_Is_Access_Constant (T, Constant_Present (Def));
+ end Access_Type_Declaration;
+
+ ----------------------------------
+ -- Add_Interface_Tag_Components --
+ ----------------------------------
+
+ procedure Add_Interface_Tag_Components (N : Node_Id; Typ : Entity_Id) is
+ Loc : constant Source_Ptr := Sloc (N);
+ L : List_Id;
+ Last_Tag : Node_Id;
+
+ procedure Add_Tag (Iface : Entity_Id);
+ -- Add tag for one of the progenitor interfaces
+
+ -------------
+ -- Add_Tag --
+ -------------
+
+ procedure Add_Tag (Iface : Entity_Id) is
+ Decl : Node_Id;
+ Def : Node_Id;
+ Tag : Entity_Id;
+ Offset : Entity_Id;
+
+ begin
+ pragma Assert (Is_Tagged_Type (Iface) and then Is_Interface (Iface));
+
+ -- This is a reasonable place to propagate predicates
+
+ if Has_Predicates (Iface) then
+ Set_Has_Predicates (Typ);
+ end if;
+
+ Def :=
+ Make_Component_Definition (Loc,
+ Aliased_Present => True,
+ Subtype_Indication =>
+ New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
+
+ Tag := Make_Temporary (Loc, 'V');
+
+ Decl :=
+ Make_Component_Declaration (Loc,
+ Defining_Identifier => Tag,
+ Component_Definition => Def);
+
+ Analyze_Component_Declaration (Decl);
+
+ Set_Analyzed (Decl);
+ Set_Ekind (Tag, E_Component);
+ Set_Is_Tag (Tag);
+ Set_Is_Aliased (Tag);
+ Set_Related_Type (Tag, Iface);
+ Init_Component_Location (Tag);
+
+ pragma Assert (Is_Frozen (Iface));
+
+ Set_DT_Entry_Count (Tag,
+ DT_Entry_Count (First_Entity (Iface)));
+
+ if No (Last_Tag) then
+ Prepend (Decl, L);
+ else
+ Insert_After (Last_Tag, Decl);
+ end if;
+
+ Last_Tag := Decl;
+
+ -- If the ancestor has discriminants we need to give special support
+ -- to store the offset_to_top value of the secondary dispatch tables.
+ -- For this purpose we add a supplementary component just after the
+ -- field that contains the tag associated with each secondary DT.
+
+ if Typ /= Etype (Typ) and then Has_Discriminants (Etype (Typ)) then
+ Def :=
+ Make_Component_Definition (Loc,
+ Subtype_Indication =>
+ New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
+
+ Offset := Make_Temporary (Loc, 'V');
+
+ Decl :=
+ Make_Component_Declaration (Loc,
+ Defining_Identifier => Offset,
+ Component_Definition => Def);
+
+ Analyze_Component_Declaration (Decl);
+
+ Set_Analyzed (Decl);
+ Set_Ekind (Offset, E_Component);
+ Set_Is_Aliased (Offset);
+ Set_Related_Type (Offset, Iface);
+ Init_Component_Location (Offset);
+ Insert_After (Last_Tag, Decl);
+ Last_Tag := Decl;
+ end if;
+ end Add_Tag;
+
+ -- Local variables
+
+ Elmt : Elmt_Id;
+ Ext : Node_Id;
+ Comp : Node_Id;
+
+ -- Start of processing for Add_Interface_Tag_Components
+
+ begin
+ if not RTE_Available (RE_Interface_Tag) then
+ Error_Msg
+ ("(Ada 2005) interface types not supported by this run-time!",
+ Sloc (N));
+ return;
+ end if;
+
+ if Ekind (Typ) /= E_Record_Type
+ or else (Is_Concurrent_Record_Type (Typ)
+ and then Is_Empty_List (Abstract_Interface_List (Typ)))
+ or else (not Is_Concurrent_Record_Type (Typ)
+ and then No (Interfaces (Typ))
+ and then Is_Empty_Elmt_List (Interfaces (Typ)))
+ then
+ return;
+ end if;
+
+ -- Find the current last tag
+
+ if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
+ Ext := Record_Extension_Part (Type_Definition (N));
+ else
+ pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
+ Ext := Type_Definition (N);
+ end if;
+
+ Last_Tag := Empty;
+
+ if not (Present (Component_List (Ext))) then
+ Set_Null_Present (Ext, False);
+ L := New_List;
+ Set_Component_List (Ext,
+ Make_Component_List (Loc,
+ Component_Items => L,
+ Null_Present => False));
+ else
+ if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
+ L := Component_Items
+ (Component_List
+ (Record_Extension_Part
+ (Type_Definition (N))));
+ else
+ L := Component_Items
+ (Component_List
+ (Type_Definition (N)));
+ end if;
+
+ -- Find the last tag component
+
+ Comp := First (L);
+ while Present (Comp) loop
+ if Nkind (Comp) = N_Component_Declaration
+ and then Is_Tag (Defining_Identifier (Comp))
+ then
+ Last_Tag := Comp;
+ end if;
+
+ Next (Comp);
+ end loop;
+ end if;
+
+ -- At this point L references the list of components and Last_Tag
+ -- references the current last tag (if any). Now we add the tag
+ -- corresponding with all the interfaces that are not implemented
+ -- by the parent.
+
+ if Present (Interfaces (Typ)) then
+ Elmt := First_Elmt (Interfaces (Typ));
+ while Present (Elmt) loop
+ Add_Tag (Node (Elmt));
+ Next_Elmt (Elmt);
+ end loop;
+ end if;
+ end Add_Interface_Tag_Components;
+
+ -------------------------------------
+ -- Add_Internal_Interface_Entities --
+ -------------------------------------
+
+ procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id) is
+ Elmt : Elmt_Id;
+ Iface : Entity_Id;
+ Iface_Elmt : Elmt_Id;
+ Iface_Prim : Entity_Id;
+ Ifaces_List : Elist_Id;
+ New_Subp : Entity_Id := Empty;
+ Prim : Entity_Id;
+ Restore_Scope : Boolean := False;
+
+ begin
+ pragma Assert (Ada_Version >= Ada_2005
+ and then Is_Record_Type (Tagged_Type)
+ and then Is_Tagged_Type (Tagged_Type)
+ and then Has_Interfaces (Tagged_Type)
+ and then not Is_Interface (Tagged_Type));
+
+ -- Ensure that the internal entities are added to the scope of the type
+
+ if Scope (Tagged_Type) /= Current_Scope then
+ Push_Scope (Scope (Tagged_Type));
+ Restore_Scope := True;
+ end if;
+
+ Collect_Interfaces (Tagged_Type, Ifaces_List);
+
+ Iface_Elmt := First_Elmt (Ifaces_List);
+ while Present (Iface_Elmt) loop
+ Iface := Node (Iface_Elmt);
+
+ -- Originally we excluded here from this processing interfaces that
+ -- are parents of Tagged_Type because their primitives are located
+ -- in the primary dispatch table (and hence no auxiliary internal
+ -- entities are required to handle secondary dispatch tables in such
+ -- case). However, these auxiliary entities are also required to
+ -- handle derivations of interfaces in formals of generics (see
+ -- Derive_Subprograms).
+
+ Elmt := First_Elmt (Primitive_Operations (Iface));
+ while Present (Elmt) loop
+ Iface_Prim := Node (Elmt);
+
+ if not Is_Predefined_Dispatching_Operation (Iface_Prim) then
+ Prim :=
+ Find_Primitive_Covering_Interface
+ (Tagged_Type => Tagged_Type,
+ Iface_Prim => Iface_Prim);
+
+ if No (Prim) and then Serious_Errors_Detected > 0 then
+ goto Continue;
+ end if;
+
+ pragma Assert (Present (Prim));
+
+ -- Ada 2012 (AI05-0197): If the name of the covering primitive
+ -- differs from the name of the interface primitive then it is
+ -- a private primitive inherited from a parent type. In such
+ -- case, given that Tagged_Type covers the interface, the
+ -- inherited private primitive becomes visible. For such
+ -- purpose we add a new entity that renames the inherited
+ -- private primitive.
+
+ if Chars (Prim) /= Chars (Iface_Prim) then
+ pragma Assert (Has_Suffix (Prim, 'P'));
+ Derive_Subprogram
+ (New_Subp => New_Subp,
+ Parent_Subp => Iface_Prim,
+ Derived_Type => Tagged_Type,
+ Parent_Type => Iface);
+ Set_Alias (New_Subp, Prim);
+ Set_Is_Abstract_Subprogram
+ (New_Subp, Is_Abstract_Subprogram (Prim));
+ end if;
+
+ Derive_Subprogram
+ (New_Subp => New_Subp,
+ Parent_Subp => Iface_Prim,
+ Derived_Type => Tagged_Type,
+ Parent_Type => Iface);
+
+ -- Ada 2005 (AI-251): Decorate internal entity Iface_Subp
+ -- associated with interface types. These entities are
+ -- only registered in the list of primitives of its
+ -- corresponding tagged type because they are only used
+ -- to fill the contents of the secondary dispatch tables.
+ -- Therefore they are removed from the homonym chains.
+
+ Set_Is_Hidden (New_Subp);
+ Set_Is_Internal (New_Subp);
+ Set_Alias (New_Subp, Prim);
+ Set_Is_Abstract_Subprogram
+ (New_Subp, Is_Abstract_Subprogram (Prim));
+ Set_Interface_Alias (New_Subp, Iface_Prim);
+
+ -- Internal entities associated with interface types are
+ -- only registered in the list of primitives of the tagged
+ -- type. They are only used to fill the contents of the
+ -- secondary dispatch tables. Therefore they are not needed
+ -- in the homonym chains.
+
+ Remove_Homonym (New_Subp);
+
+ -- Hidden entities associated with interfaces must have set
+ -- the Has_Delay_Freeze attribute to ensure that, in case of
+ -- locally defined tagged types (or compiling with static
+ -- dispatch tables generation disabled) the corresponding
+ -- entry of the secondary dispatch table is filled when
+ -- such an entity is frozen.
+
+ Set_Has_Delayed_Freeze (New_Subp);
+ end if;
+
+ <<Continue>>
+ Next_Elmt (Elmt);
+ end loop;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+
+ if Restore_Scope then
+ Pop_Scope;
+ end if;
+ end Add_Internal_Interface_Entities;
+
+ -----------------------------------
+ -- Analyze_Component_Declaration --
+ -----------------------------------
+
+ procedure Analyze_Component_Declaration (N : Node_Id) is
+ Id : constant Entity_Id := Defining_Identifier (N);
+ E : constant Node_Id := Expression (N);
+ Typ : constant Node_Id :=
+ Subtype_Indication (Component_Definition (N));
+ T : Entity_Id;
+ P : Entity_Id;
+
+ function Contains_POC (Constr : Node_Id) return Boolean;
+ -- Determines whether a constraint uses the discriminant of a record
+ -- type thus becoming a per-object constraint (POC).
+
+ function Is_Known_Limited (Typ : Entity_Id) return Boolean;
+ -- Typ is the type of the current component, check whether this type is
+ -- a limited type. Used to validate declaration against that of
+ -- enclosing record.
+
+ ------------------
+ -- Contains_POC --
+ ------------------
+
+ function Contains_POC (Constr : Node_Id) return Boolean is
+ begin
+ -- Prevent cascaded errors
+
+ if Error_Posted (Constr) then
+ return False;
+ end if;
+
+ case Nkind (Constr) is
+ when N_Attribute_Reference =>
+ return
+ Attribute_Name (Constr) = Name_Access
+ and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
+
+ when N_Discriminant_Association =>
+ return Denotes_Discriminant (Expression (Constr));
+
+ when N_Identifier =>
+ return Denotes_Discriminant (Constr);
+
+ when N_Index_Or_Discriminant_Constraint =>
+ declare
+ IDC : Node_Id;
+
+ begin
+ IDC := First (Constraints (Constr));
+ while Present (IDC) loop
+
+ -- One per-object constraint is sufficient
+
+ if Contains_POC (IDC) then
+ return True;
+ end if;
+
+ Next (IDC);
+ end loop;
+
+ return False;
+ end;
+
+ when N_Range =>
+ return Denotes_Discriminant (Low_Bound (Constr))
+ or else
+ Denotes_Discriminant (High_Bound (Constr));
+
+ when N_Range_Constraint =>
+ return Denotes_Discriminant (Range_Expression (Constr));
+
+ when others =>
+ return False;
+
+ end case;
+ end Contains_POC;
+
+ ----------------------
+ -- Is_Known_Limited --
+ ----------------------
+
+ function Is_Known_Limited (Typ : Entity_Id) return Boolean is
+ P : constant Entity_Id := Etype (Typ);
+ R : constant Entity_Id := Root_Type (Typ);
+
+ begin
+ if Is_Limited_Record (Typ) then
+ return True;
+
+ -- If the root type is limited (and not a limited interface)
+ -- so is the current type
+
+ elsif Is_Limited_Record (R)
+ and then (not Is_Interface (R) or else not Is_Limited_Interface (R))
+ then
+ return True;
+
+ -- Else the type may have a limited interface progenitor, but a
+ -- limited record parent.
+
+ elsif R /= P and then Is_Limited_Record (P) then
+ return True;
+
+ else
+ return False;
+ end if;
+ end Is_Known_Limited;
+
+ -- Start of processing for Analyze_Component_Declaration
+
+ begin
+ Generate_Definition (Id);
+ Enter_Name (Id);
+
+ if Present (Typ) then
+ T := Find_Type_Of_Object
+ (Subtype_Indication (Component_Definition (N)), N);
+
+ if not Nkind_In (Typ, N_Identifier, N_Expanded_Name) then
+ Check_SPARK_Restriction ("subtype mark required", Typ);
+ end if;
+
+ -- Ada 2005 (AI-230): Access Definition case
+
+ else
+ pragma Assert (Present
+ (Access_Definition (Component_Definition (N))));
+
+ T := Access_Definition
+ (Related_Nod => N,
+ N => Access_Definition (Component_Definition (N)));
+ Set_Is_Local_Anonymous_Access (T);
+
+ -- Ada 2005 (AI-254)
+
+ if Present (Access_To_Subprogram_Definition
+ (Access_Definition (Component_Definition (N))))
+ and then Protected_Present (Access_To_Subprogram_Definition
+ (Access_Definition
+ (Component_Definition (N))))
+ then
+ T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
+ end if;
+ end if;
+
+ -- If the subtype is a constrained subtype of the enclosing record,
+ -- (which must have a partial view) the back-end does not properly
+ -- handle the recursion. Rewrite the component declaration with an
+ -- explicit subtype indication, which is acceptable to Gigi. We can copy
+ -- the tree directly because side effects have already been removed from
+ -- discriminant constraints.
+
+ if Ekind (T) = E_Access_Subtype
+ and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
+ and then Comes_From_Source (T)
+ and then Nkind (Parent (T)) = N_Subtype_Declaration
+ and then Etype (Directly_Designated_Type (T)) = Current_Scope
+ then
+ Rewrite
+ (Subtype_Indication (Component_Definition (N)),
+ New_Copy_Tree (Subtype_Indication (Parent (T))));
+ T := Find_Type_Of_Object
+ (Subtype_Indication (Component_Definition (N)), N);
+ end if;
+
+ -- If the component declaration includes a default expression, then we
+ -- check that the component is not of a limited type (RM 3.7(5)),
+ -- and do the special preanalysis of the expression (see section on
+ -- "Handling of Default and Per-Object Expressions" in the spec of
+ -- package Sem).
+
+ if Present (E) then
+ Check_SPARK_Restriction ("default expression is not allowed", E);
+ Preanalyze_Spec_Expression (E, T);
+ Check_Initialization (T, E);
+
+ if Ada_Version >= Ada_2005
+ and then Ekind (T) = E_Anonymous_Access_Type
+ and then Etype (E) /= Any_Type
+ then
+ -- Check RM 3.9.2(9): "if the expected type for an expression is
+ -- an anonymous access-to-specific tagged type, then the object
+ -- designated by the expression shall not be dynamically tagged
+ -- unless it is a controlling operand in a call on a dispatching
+ -- operation"
+
+ if Is_Tagged_Type (Directly_Designated_Type (T))
+ and then
+ Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
+ and then
+ Ekind (Directly_Designated_Type (Etype (E))) =
+ E_Class_Wide_Type
+ then
+ Error_Msg_N
+ ("access to specific tagged type required (RM 3.9.2(9))", E);
+ end if;
+
+ -- (Ada 2005: AI-230): Accessibility check for anonymous
+ -- components
+
+ if Type_Access_Level (Etype (E)) >
+ Deepest_Type_Access_Level (T)
+ then
+ Error_Msg_N
+ ("expression has deeper access level than component " &
+ "(RM 3.10.2 (12.2))", E);
+ end if;
+
+ -- The initialization expression is a reference to an access
+ -- discriminant. The type of the discriminant is always deeper
+ -- than any access type.
+
+ if Ekind (Etype (E)) = E_Anonymous_Access_Type
+ and then Is_Entity_Name (E)
+ and then Ekind (Entity (E)) = E_In_Parameter
+ and then Present (Discriminal_Link (Entity (E)))
+ then
+ Error_Msg_N
+ ("discriminant has deeper accessibility level than target",
+ E);
+ end if;
+ end if;
+ end if;
+
+ -- The parent type may be a private view with unknown discriminants,
+ -- and thus unconstrained. Regular components must be constrained.
+
+ if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
+ if Is_Class_Wide_Type (T) then
+ Error_Msg_N
+ ("class-wide subtype with unknown discriminants" &
+ " in component declaration",
+ Subtype_Indication (Component_Definition (N)));
+ else
+ Error_Msg_N
+ ("unconstrained subtype in component declaration",
+ Subtype_Indication (Component_Definition (N)));
+ end if;
+
+ -- Components cannot be abstract, except for the special case of
+ -- the _Parent field (case of extending an abstract tagged type)
+
+ elsif Is_Abstract_Type (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_2005 and then Can_Never_Be_Null (T) then
+ Null_Exclusion_Static_Checks (N);
+ end if;
+
+ -- If this component is private (or depends on a private type), flag the
+ -- record type to indicate that some operations are not available.
+
+ P := Private_Component (T);
+
+ if Present (P) then
+
+ -- Check for circular definitions
+
+ if P = Any_Type then
+ Set_Etype (Id, Any_Type);
+
+ -- There is a gap in the visibility of operations only if the
+ -- component type is not defined in the scope of the record type.
+
+ elsif Scope (P) = Scope (Current_Scope) then
+ null;
+
+ elsif Is_Limited_Type (P) then
+ Set_Is_Limited_Composite (Current_Scope);
+
+ else
+ Set_Is_Private_Composite (Current_Scope);
+ end if;
+ end if;
+
+ if P /= Any_Type
+ and then Is_Limited_Type (T)
+ and then Chars (Id) /= Name_uParent
+ and then Is_Tagged_Type (Current_Scope)
+ then
+ if Is_Derived_Type (Current_Scope)
+ and then not Is_Known_Limited (Current_Scope)
+ then
+ Error_Msg_N
+ ("extension of nonlimited type cannot have limited components",
+ N);
+
+ if Is_Interface (Root_Type (Current_Scope)) then
+ Error_Msg_N
+ ("\limitedness is not inherited from limited interface", N);
+ Error_Msg_N ("\add LIMITED to type indication", N);
+ end if;
+
+ Explain_Limited_Type (T, N);
+ Set_Etype (Id, Any_Type);
+ Set_Is_Limited_Composite (Current_Scope, False);
+
+ elsif not Is_Derived_Type (Current_Scope)
+ and then not Is_Limited_Record (Current_Scope)
+ and then not Is_Concurrent_Type (Current_Scope)
+ then
+ Error_Msg_N
+ ("nonlimited tagged type cannot have limited components", N);
+ Explain_Limited_Type (T, N);
+ Set_Etype (Id, Any_Type);
+ Set_Is_Limited_Composite (Current_Scope, False);
+ end if;
+ end if;
+
+ Set_Original_Record_Component (Id, Id);
+
+ if Has_Aspects (N) then
+ Analyze_Aspect_Specifications (N, Id);
+ end if;
+
+ Analyze_Dimension (N);
+ end Analyze_Component_Declaration;
+
+ --------------------------
+ -- Analyze_Declarations --
+ --------------------------
+
+ procedure Analyze_Declarations (L : List_Id) is
+ D : Node_Id;
+ Freeze_From : Entity_Id := Empty;
+ Next_Node : Node_Id;
+
+ 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
+ if Restriction_Check_Required (SPARK) then
+ Check_Later_Vs_Basic_Declarations (L, During_Parsing => False);
+ end if;
+
+ D := First (L);
+ while Present (D) loop
+
+ -- Package spec cannot contain a package declaration in SPARK
+
+ if Nkind (D) = N_Package_Declaration
+ and then Nkind (Parent (L)) = N_Package_Specification
+ then
+ Check_SPARK_Restriction
+ ("package specification cannot contain a package declaration",
+ D);
+ end if;
+
+ -- 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_In (Parent (L), N_Component_List,
+ N_Task_Definition,
+ 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 some expander-generated bodies. If these
+ -- are generated at places where in general language rules would not
+ -- allow a freeze point, then we assume that the expander has
+ -- explicitly checked that all required types are properly frozen,
+ -- and we do not cause general freezing here. This special circuit
+ -- is used when the encountered body is marked as having already
+ -- been analyzed.
+
+ -- In all other cases (bodies that come from source, and expander
+ -- generated bodies that have not been analyzed yet), freeze all
+ -- types now. Note that in the latter case, the expander must take
+ -- care to attach the bodies at a proper place in the tree so as to
+ -- not cause unwanted freezing at that point.
+
+ elsif not Analyzed (Next_Node)
+ and then (Nkind_In (Next_Node, N_Subprogram_Body,
+ N_Entry_Body,
+ N_Package_Body,
+ N_Protected_Body,
+ 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;
+
+ -- One more thing to do, we need to scan the declarations to check
+ -- for any precondition/postcondition pragmas (Pre/Post aspects have
+ -- by this stage been converted into corresponding pragmas). It is
+ -- at this point that we analyze the expressions in such pragmas,
+ -- to implement the delayed visibility requirement.
+
+ declare
+ Decl : Node_Id;
+ Spec : Node_Id;
+ Sent : Entity_Id;
+ Prag : Node_Id;
+
+ begin
+ Decl := First (L);
+ while Present (Decl) loop
+ if Nkind (Original_Node (Decl)) = N_Subprogram_Declaration then
+ Spec := Specification (Original_Node (Decl));
+ Sent := Defining_Unit_Name (Spec);
+
+ -- Analyze preconditions and postconditions
+
+ Prag := Spec_PPC_List (Contract (Sent));
+ while Present (Prag) loop
+ Analyze_PPC_In_Decl_Part (Prag, Sent);
+ Prag := Next_Pragma (Prag);
+ end loop;
+
+ -- Analyze contract-cases and test-cases
+
+ Prag := Spec_CTC_List (Contract (Sent));
+ while Present (Prag) loop
+ Analyze_CTC_In_Decl_Part (Prag, Sent);
+ Prag := Next_Pragma (Prag);
+ end loop;
+
+ -- At this point, entities have been attached to identifiers.
+ -- This is required to be able to detect suspicious contracts.
+
+ Check_Subprogram_Contract (Sent);
+ end if;
+
+ Next (Decl);
+ end loop;
+ end;
+ end Analyze_Declarations;
+
+ -----------------------------------
+ -- Analyze_Full_Type_Declaration --
+ -----------------------------------
+
+ procedure Analyze_Full_Type_Declaration (N : Node_Id) is
+ Def : constant Node_Id := Type_Definition (N);
+ Def_Id : constant Entity_Id := Defining_Identifier (N);
+ T : Entity_Id;
+ Prev : Entity_Id;
+
+ Is_Remote : constant Boolean :=
+ (Is_Remote_Types (Current_Scope)
+ or else Is_Remote_Call_Interface (Current_Scope))
+ and then not (In_Private_Part (Current_Scope)
+ or else In_Package_Body (Current_Scope));
+
+ procedure Check_Ops_From_Incomplete_Type;
+ -- If there is a tagged incomplete partial view of the type, traverse
+ -- the primitives of the incomplete view and change the type of any
+ -- controlling formals and result to indicate the full view. The
+ -- primitives will be added to the full type's primitive operations
+ -- list later in Sem_Disp.Check_Operation_From_Incomplete_Type (which
+ -- is called from Process_Incomplete_Dependents).
+
+ ------------------------------------
+ -- Check_Ops_From_Incomplete_Type --
+ ------------------------------------
+
+ procedure Check_Ops_From_Incomplete_Type is
+ Elmt : Elmt_Id;
+ Formal : Entity_Id;
+ Op : Entity_Id;
+
+ begin
+ if Prev /= T
+ and then Ekind (Prev) = E_Incomplete_Type
+ and then Is_Tagged_Type (Prev)
+ and then Is_Tagged_Type (T)
+ then
+ Elmt := First_Elmt (Primitive_Operations (Prev));
+ while Present (Elmt) loop
+ Op := Node (Elmt);
+
+ Formal := First_Formal (Op);
+ while Present (Formal) loop
+ if Etype (Formal) = Prev then
+ Set_Etype (Formal, T);
+ end if;
+
+ Next_Formal (Formal);
+ end loop;
+
+ if Etype (Op) = Prev then
+ Set_Etype (Op, T);
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+ end if;
+ end Check_Ops_From_Incomplete_Type;
+
+ -- Start of processing for Analyze_Full_Type_Declaration
+
+ begin
+ Prev := Find_Type_Name (N);
+
+ -- The full view, if present, now points to the current type
+
+ -- Ada 2005 (AI-50217): If the type was previously decorated when
+ -- imported through a LIMITED WITH clause, it appears as incomplete
+ -- but has no full view.
+
+ if Ekind (Prev) = E_Incomplete_Type
+ and then Present (Full_View (Prev))
+ then
+ T := Full_View (Prev);
+ else
+ T := Prev;
+ end if;
+
+ Set_Is_Pure (T, Is_Pure (Current_Scope));
+
+ -- We set the flag Is_First_Subtype here. It is needed to set the
+ -- corresponding flag for the Implicit class-wide-type created
+ -- during tagged types processing.
+
+ Set_Is_First_Subtype (T, True);
+
+ -- Only composite types other than array types are allowed to have
+ -- discriminants.
+
+ case Nkind (Def) is
+
+ -- For derived types, the rule will be checked once we've figured
+ -- out the parent type.
+
+ when N_Derived_Type_Definition =>
+ null;
+
+ -- For record types, discriminants are allowed, unless we are in
+ -- SPARK.
+
+ when N_Record_Definition =>
+ if Present (Discriminant_Specifications (N)) then
+ Check_SPARK_Restriction
+ ("discriminant type is not allowed",
+ Defining_Identifier
+ (First (Discriminant_Specifications (N))));
+ end if;
+
+ 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, then calling stubs and specific stream attributes
+ -- 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);
+
+ -- If declaration has a parse error, nothing to elaborate.
+
+ when N_Error =>
+ null;
+
+ when others =>
+ raise Program_Error;
+
+ end case;
+ end if;
+
+ if Etype (T) = Any_Type then
+ return;
+ end if;
+
+ -- Controlled type is not allowed in SPARK
+
+ if Is_Visibly_Controlled (T) then
+ Check_SPARK_Restriction ("controlled type is not allowed", N);
+ end if;
+
+ -- Some common processing for all types
+
+ Set_Depends_On_Private (T, Has_Private_Component (T));
+ Check_Ops_From_Incomplete_Type;
+
+ -- Both the declared entity, and its anonymous base type if one
+ -- was created, need freeze nodes allocated.
+
+ declare
+ B : constant Entity_Id := Base_Type (T);
+
+ begin
+ -- In the case where the base type differs 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.
+
+ -- This does not apply if the base type is a generic type, whose
+ -- declaration is independent of the current derived definition.
+
+ if B /= T and then not Is_Generic_Type (B) then
+ Ensure_Freeze_Node (B);
+ Set_First_Subtype_Link (Freeze_Node (B), T);
+ end if;
+
+ -- A type that is imported through a limited_with clause cannot
+ -- generate any code, and thus need not be frozen. However, an access
+ -- type with an imported designated type needs a finalization list,
+ -- which may be referenced in some other package that has non-limited
+ -- visibility on the designated type. Thus we must create the
+ -- finalization list at the point the access type is frozen, to
+ -- prevent unsatisfied references at link time.
+
+ if not From_With_Type (T) or else Is_Access_Type (T) then
+ Set_Has_Delayed_Freeze (T);
+ end if;
+ end;
+
+ -- Case where 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.
+
+ -- Also, we want to kill Has_Pragma_Unreferenced temporarily here
+ -- since we don't want a complaint about the full type being an
+ -- unwanted reference to the private type
+
+ declare
+ B : constant Boolean := Has_Pragma_Unreferenced (T);
+ begin
+ Set_Has_Pragma_Unreferenced (T, False);
+ Generate_Reference (T, T, 'c');
+ Set_Has_Pragma_Unreferenced (T, B);
+ end;
+
+ 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;
+
+ if Chars (Scope (Def_Id)) = Name_System
+ and then Chars (Def_Id) = Name_Address
+ and then Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N)))
+ then
+ Set_Is_Descendent_Of_Address (Def_Id);
+ Set_Is_Descendent_Of_Address (Base_Type (Def_Id));
+ Set_Is_Descendent_Of_Address (Prev);
+ end if;
+
+ Set_Optimize_Alignment_Flags (Def_Id);
+ Check_Eliminated (Def_Id);
+
+ -- If the declaration is a completion and aspects are present, apply
+ -- them to the entity for the type which is currently the partial
+ -- view, but which is the one that will be frozen.
+
+ if Has_Aspects (N) then
+ if Prev /= Def_Id then
+ Analyze_Aspect_Specifications (N, Prev);
+ else
+ Analyze_Aspect_Specifications (N, Def_Id);
+ end if;
+ end if;
+ end Analyze_Full_Type_Declaration;
+
+ ----------------------------------
+ -- Analyze_Incomplete_Type_Decl --
+ ----------------------------------
+
+ procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
+ F : constant Boolean := Is_Pure (Current_Scope);
+ T : Entity_Id;
+
+ begin
+ Check_SPARK_Restriction ("incomplete type is not allowed", N);
+
+ Generate_Definition (Defining_Identifier (N));
+
+ -- Process an incomplete declaration. The identifier must not have been
+ -- declared already in the scope. However, an incomplete declaration may
+ -- appear in the private part of a package, for a private type that has
+ -- already been declared.
+
+ -- In this case, the discriminants (if any) must match
+
+ T := Find_Type_Name (N);
+
+ Set_Ekind (T, E_Incomplete_Type);
+ Init_Size_Align (T);
+ Set_Is_First_Subtype (T, True);
+ Set_Etype (T, T);
+
+ -- Ada 2005 (AI-326): Minimum decoration to give support to tagged
+ -- incomplete types.
+
+ if Tagged_Present (N) then
+ Set_Is_Tagged_Type (T);
+ Make_Class_Wide_Type (T);
+ Set_Direct_Primitive_Operations (T, New_Elmt_List);
+ end if;
+
+ Push_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
+ -- declared before the full view of the type. The full views of those
+ -- subtypes will be built after the full view of the type.
+
+ Set_Private_Dependents (T, New_Elmt_List);
+ Set_Is_Pure (T, F);
+ end Analyze_Incomplete_Type_Decl;
+
+ -----------------------------------
+ -- Analyze_Interface_Declaration --
+ -----------------------------------
+
+ procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
+ CW : constant Entity_Id := Class_Wide_Type (T);
+
+ begin
+ Set_Is_Tagged_Type (T);
+
+ Set_Is_Limited_Record (T, Limited_Present (Def)
+ or else Task_Present (Def)
+ or else Protected_Present (Def)
+ or else Synchronized_Present (Def));
+
+ -- Type is abstract if full declaration carries keyword, or if previous
+ -- partial view did.
+
+ Set_Is_Abstract_Type (T);
+ Set_Is_Interface (T);
+
+ -- Type is a limited interface if it includes the keyword limited, task,
+ -- protected, or synchronized.
+
+ Set_Is_Limited_Interface
+ (T, Limited_Present (Def)
+ or else Protected_Present (Def)
+ or else Synchronized_Present (Def)
+ or else Task_Present (Def));
+
+ Set_Interfaces (T, New_Elmt_List);
+ Set_Direct_Primitive_Operations (T, New_Elmt_List);
+
+ -- Complete the decoration of the class-wide entity if it was already
+ -- built (i.e. during the creation of the limited view)
+
+ if Present (CW) then
+ Set_Is_Interface (CW);
+ Set_Is_Limited_Interface (CW, Is_Limited_Interface (T));
+ end if;
+
+ -- Check runtime support for synchronized interfaces
+
+ if VM_Target = No_VM
+ and then (Is_Task_Interface (T)
+ or else Is_Protected_Interface (T)
+ or else Is_Synchronized_Interface (T))
+ and then not RTE_Available (RE_Select_Specific_Data)
+ then
+ Error_Msg_CRT ("synchronized interfaces", T);
+ end if;
+ end Analyze_Interface_Declaration;
+
+ -----------------------------
+ -- Analyze_Itype_Reference --
+ -----------------------------
+
+ -- Nothing to do. This node is placed in the tree only for the benefit of
+ -- back end processing, and has no effect on the semantic processing.
+
+ procedure Analyze_Itype_Reference (N : Node_Id) is
+ begin
+ pragma Assert (Is_Itype (Itype (N)));
+ null;
+ end Analyze_Itype_Reference;
+
+ --------------------------------
+ -- Analyze_Number_Declaration --
+ --------------------------------
+
+ procedure Analyze_Number_Declaration (N : Node_Id) is
+ Id : constant Entity_Id := Defining_Identifier (N);
+ E : constant Node_Id := Expression (N);
+ T : Entity_Id;
+ Index : Interp_Index;
+ It : Interp;
+
+ begin
+ Generate_Definition (Id);
+ Enter_Name (Id);
+
+ -- This is an optimization of a common case of an integer literal
+
+ if Nkind (E) = N_Integer_Literal then
+ Set_Is_Static_Expression (E, True);
+ Set_Etype (E, Universal_Integer);
+
+ Set_Etype (Id, Universal_Integer);
+ Set_Ekind (Id, E_Named_Integer);
+ Set_Is_Frozen (Id, True);
+ return;
+ end if;
+
+ Set_Is_Pure (Id, Is_Pure (Current_Scope));
+
+ -- Process expression, replacing error by integer zero, to avoid
+ -- cascaded errors or aborts further along in the processing
+
+ -- Replace Error by integer zero, which seems least likely to cause
+ -- cascaded errors.
+
+ if E = Error then
+ Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
+ Set_Error_Posted (E);
+ end if;
+
+ Analyze (E);
+
+ -- Verify that the expression is static and numeric. If
+ -- the expression is overloaded, we apply the preference
+ -- rule that favors root numeric types.
+
+ if not Is_Overloaded (E) then
+ T := Etype (E);
+
+ else
+ T := Any_Type;
+
+ Get_First_Interp (E, Index, It);
+ while Present (It.Typ) loop
+ if (Is_Integer_Type (It.Typ) or else Is_Real_Type (It.Typ))
+ and then (Scope (Base_Type (It.Typ))) = Standard_Standard
+ then
+ if T = Any_Type then
+ T := It.Typ;
+
+ elsif It.Typ = Universal_Real
+ or else It.Typ = Universal_Integer
+ then
+ -- Choose universal interpretation over any other
+
+ T := It.Typ;
+ exit;
+ end if;
+ end if;
+
+ Get_Next_Interp (Index, It);
+ end loop;
+ end if;
+
+ if Is_Integer_Type (T) then
+ Resolve (E, T);
+ Set_Etype (Id, Universal_Integer);
+ Set_Ekind (Id, E_Named_Integer);
+
+ elsif Is_Real_Type (T) then
+
+ -- Because the real value is converted to universal_real, this is a
+ -- legal context for a universal fixed expression.
+
+ if T = Universal_Fixed then
+ declare
+ Loc : constant Source_Ptr := Sloc (N);
+ Conv : constant Node_Id := Make_Type_Conversion (Loc,
+ Subtype_Mark =>
+ New_Occurrence_Of (Universal_Real, Loc),
+ Expression => Relocate_Node (E));
+
+ begin
+ Rewrite (E, Conv);
+ Analyze (E);
+ end;
+
+ elsif T = Any_Fixed then
+ Error_Msg_N ("illegal context for mixed mode operation", E);
+
+ -- Expression is of the form : universal_fixed * integer. Try to
+ -- resolve as universal_real.
+
+ T := Universal_Real;
+ Set_Etype (E, T);
+ end if;
+
+ Resolve (E, T);
+ Set_Etype (Id, Universal_Real);
+ Set_Ekind (Id, E_Named_Real);
+
+ else
+ Wrong_Type (E, Any_Numeric);
+ Resolve (E, T);
+
+ Set_Etype (Id, T);
+ Set_Ekind (Id, E_Constant);
+ Set_Never_Set_In_Source (Id, True);
+ Set_Is_True_Constant (Id, True);
+ return;
+ end if;
+
+ if Nkind_In (E, N_Integer_Literal, 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 Count_Tasks (T : Entity_Id) return Uint;
+ -- This function is called when a non-generic library level object of a
+ -- task type is declared. Its 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.
+
+ -----------------
+ -- 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 generated by the original Object Definition
+
+ -- 2. Those generated by the Expression
+
+ -- 3. Those used to constrain the Object Definition with the
+ -- expression constraints when the definition 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 Present (Prev_Entity)
+ and then
+
+ -- If the homograph is an implicit subprogram, it is overridden
+ -- by the current declaration.
+
+ ((Is_Overloadable (Prev_Entity)
+ and then Is_Inherited_Operation (Prev_Entity))
+
+ -- The current object is a discriminal generated for an entry
+ -- family index. Even though the index is a constant, in this
+ -- particular context there is no true constant redeclaration.
+ -- Enter_Name will handle the visibility.
+
+ or else
+ (Is_Discriminal (Id)
+ and then Ekind (Discriminal_Link (Id)) =
+ E_Entry_Index_Parameter)
+
+ -- The current object is the renaming for a generic declared
+ -- within the instance.
+
+ or else
+ (Ekind (Prev_Entity) = E_Package
+ and then Nkind (Parent (Prev_Entity)) =
+ N_Package_Renaming_Declaration
+ and then not Comes_From_Source (Prev_Entity)
+ and then Is_Generic_Instance (Renamed_Entity (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);
+ goto Leave;
+ 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);
+
+ Mark_Coextensions (N, Object_Definition (N));
+
+ T := Find_Type_Of_Object (Object_Definition (N), N);
+
+ if Nkind (Object_Definition (N)) = N_Access_Definition
+ and then Present
+ (Access_To_Subprogram_Definition (Object_Definition (N)))
+ and then Protected_Present
+ (Access_To_Subprogram_Definition (Object_Definition (N)))
+ then
+ T := Replace_Anonymous_Access_To_Protected_Subprogram (N);
+ end if;
+
+ if Error_Posted (Id) then
+ Set_Etype (Id, T);
+ Set_Ekind (Id, E_Variable);
+ goto Leave;
+ end if;
+ end if;
+
+ -- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
+ -- out some static checks
+
+ if Ada_Version >= Ada_2005
+ and then Can_Never_Be_Null (T)
+ then
+ -- In case of aggregates we must also take care of the correct
+ -- initialization of nested aggregates bug this is done at the
+ -- point of the analysis of the aggregate (see sem_aggr.adb)
+
+ if Present (Expression (N))
+ and then Nkind (Expression (N)) = N_Aggregate
+ then
+ null;
+
+ else
+ declare
+ Save_Typ : constant Entity_Id := Etype (Id);
+ begin
+ Set_Etype (Id, T); -- Temp. decoration for static checks
+ Null_Exclusion_Static_Checks (N);
+ Set_Etype (Id, Save_Typ);
+ end;
+ end if;
+ end if;
+
+ -- Object is marked pure if it is in a pure scope
+
+ 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
+
+ -- A deferred constant may appear in the declarative part of the
+ -- following constructs:
+
+ -- blocks
+ -- entry bodies
+ -- extended return statements
+ -- package specs
+ -- package bodies
+ -- subprogram bodies
+ -- task bodies
+
+ -- When declared inside a package spec, a deferred constant must be
+ -- completed by a full constant declaration or pragma Import. In all
+ -- other cases, the only proper completion is pragma Import. Extended
+ -- return statements are flagged as invalid contexts because they do
+ -- not have a declarative part and so cannot accommodate the pragma.
+
+ if Ekind (Current_Scope) = E_Return_Statement then
+ Error_Msg_N
+ ("invalid context for deferred constant declaration (RM 7.4)",
+ N);
+ Error_Msg_N
+ ("\declaration requires an initialization expression",
+ N);
+ Set_Constant_Present (N, False);
+
+ -- In Ada 83, deferred constant must be of private type
+
+ elsif not Is_Private_Type (T) then
+ if Ada_Version = Ada_83 and then Comes_From_Source (N) then
+ Error_Msg_N
+ ("(Ada 83) deferred constant must be private type", N);
+ end if;
+ end if;
+
+ -- If not a deferred constant, then object declaration freezes its type
+
+ else
+ Check_Fully_Declared (T, N);
+ Freeze_Before (N, T);
+ end if;
+
+ -- If the object was created by a constrained array definition, then
+ -- set the link in both the anonymous base type and anonymous subtype
+ -- that are built to represent the array type to point to the object.
+
+ if Nkind (Object_Definition (Declaration_Node (Id))) =
+ N_Constrained_Array_Definition
+ then
+ Set_Related_Array_Object (T, Id);
+ Set_Related_Array_Object (Base_Type (T), Id);
+ end if;
+
+ -- Special checks for protected objects not at library level
+
+ if Is_Protected_Type (T)
+ and then not Is_Library_Level_Entity (Id)
+ then
+ Check_Restriction (No_Local_Protected_Objects, Id);
+
+ -- Protected objects with interrupt handlers must be at library level
+
+ -- Ada 2005: this test is not needed (and the corresponding clause
+ -- in the RM is removed) because accessibility checks are sufficient
+ -- to make handlers not at the library level illegal.
+
+ -- AI05-0303: the AI is in fact a binding interpretation, and thus
+ -- applies to the '95 version of the language as well.
+
+ if Has_Interrupt_Handler (T) and then Ada_Version < Ada_95 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;
+
+ -- These checks should be performed before the initialization expression
+ -- is considered, so that the Object_Definition node is still the same
+ -- as in source code.
+
+ -- In SPARK, the nominal subtype shall be given by a subtype mark and
+ -- shall not be unconstrained. (The only exception to this is the
+ -- admission of declarations of constants of type String.)
+
+ if not
+ Nkind_In (Object_Definition (N), N_Identifier, N_Expanded_Name)
+ then
+ Check_SPARK_Restriction
+ ("subtype mark required", Object_Definition (N));
+
+ elsif Is_Array_Type (T)
+ and then not Is_Constrained (T)
+ and then T /= Standard_String
+ then
+ Check_SPARK_Restriction
+ ("subtype mark of constrained type expected",
+ Object_Definition (N));
+ end if;
+
+ -- There are no aliased objects in SPARK
+
+ if Aliased_Present (N) then
+ Check_SPARK_Restriction ("aliased object is not allowed", N);
+ end if;
+
+ -- Process initialization expression if present and not in error
+
+ if Present (E) and then E /= Error then
+
+ -- Generate an error in case of CPP class-wide object initialization.
+ -- Required because otherwise the expansion of the class-wide
+ -- assignment would try to use 'size to initialize the object
+ -- (primitive that is not available in CPP tagged types).
+
+ if Is_Class_Wide_Type (Act_T)
+ and then
+ (Is_CPP_Class (Root_Type (Etype (Act_T)))
+ or else
+ (Present (Full_View (Root_Type (Etype (Act_T))))
+ and then
+ Is_CPP_Class (Full_View (Root_Type (Etype (Act_T))))))
+ then
+ Error_Msg_N
+ ("predefined assignment not available for 'C'P'P tagged types",
+ E);
+ end if;
+
+ Mark_Coextensions (N, E);
+ Analyze (E);
+
+ -- In case of errors detected in the analysis of the expression,
+ -- decorate it with the expected type to avoid cascaded errors
+
+ if No (Etype (E)) then
+ Set_Etype (E, T);
+ end if;
+
+ -- If an initialization expression is present, then we set the
+ -- Is_True_Constant flag. It will be reset if this is a variable
+ -- and it is indeed modified.
+
+ Set_Is_True_Constant (Id, True);
+
+ -- If we are analyzing a constant declaration, set its completion
+ -- flag after analyzing and resolving the expression.
+
+ if Constant_Present (N) then
+ Set_Has_Completion (Id);
+ end if;
+
+ -- Set type and resolve (type may be overridden later on). Note:
+ -- Ekind (Id) must still be E_Void at this point so that incorrect
+ -- early usage within E is properly diagnosed.
+
+ Set_Etype (Id, T);
+ Resolve (E, T);
+
+ -- No further action needed if E is a call to an inlined function
+ -- which returns an unconstrained type and it has been expanded into
+ -- a procedure call. In that case N has been replaced by an object
+ -- declaration without initializing expression and it has been
+ -- analyzed (see Expand_Inlined_Call).
+
+ if Debug_Flag_Dot_K
+ and then Expander_Active
+ and then Nkind (E) = N_Function_Call
+ and then Nkind (Name (E)) in N_Has_Entity
+ and then Is_Inlined (Entity (Name (E)))
+ and then not Is_Constrained (Etype (E))
+ and then Analyzed (N)
+ and then No (Expression (N))
+ then
+ return;
+ end if;
+
+ -- If E is null and has been replaced by an N_Raise_Constraint_Error
+ -- node (which was marked already-analyzed), we need to set the type
+ -- to something other than Any_Access in order to keep gigi happy.
+
+ if Etype (E) = Any_Access then
+ Set_Etype (E, T);
+ end if;
+
+ -- If the object is an access to variable, the initialization
+ -- expression cannot be an access to constant.
+
+ if Is_Access_Type (T)
+ and then not Is_Access_Constant (T)
+ and then Is_Access_Type (Etype (E))
+ and then Is_Access_Constant (Etype (E))
+ then
+ Error_Msg_N
+ ("access to variable cannot be initialized "
+ & "with an access-to-constant expression", E);
+ end if;
+
+ if not Assignment_OK (N) then
+ Check_Initialization (T, E);
+ end if;
+
+ Check_Unset_Reference (E);
+
+ -- If this is a variable, then set current value. If this is a
+ -- declared constant of a scalar type with a static expression,
+ -- indicate that it is always valid.
+
+ if not Constant_Present (N) then
+ if Compile_Time_Known_Value (E) then
+ Set_Current_Value (Id, E);
+ end if;
+
+ elsif Is_Scalar_Type (T)
+ and then Is_OK_Static_Expression (E)
+ then
+ Set_Is_Known_Valid (Id);
+ end if;
+
+ -- Deal with setting of null flags
+
+ if Is_Access_Type (T) then
+ if Known_Non_Null (E) then
+ Set_Is_Known_Non_Null (Id, True);
+ elsif Known_Null (E)
+ and then not Can_Never_Be_Null (Id)
+ then
+ Set_Is_Known_Null (Id, True);
+ end if;
+ end if;
+
+ -- Check incorrect use of dynamically tagged expressions.
+
+ if Is_Tagged_Type (T) then
+ Check_Dynamically_Tagged_Expression
+ (Expr => E,
+ Typ => T,
+ Related_Nod => N);
+ end if;
+
+ Apply_Scalar_Range_Check (E, T);
+ Apply_Static_Length_Check (E, T);
+
+ if Nkind (Original_Node (N)) = N_Object_Declaration
+ and then Comes_From_Source (Original_Node (N))
+
+ -- Only call test if needed
+
+ and then Restriction_Check_Required (SPARK)
+ and then not Is_SPARK_Initialization_Expr (E)
+ then
+ Check_SPARK_Restriction
+ ("initialization expression is not appropriate", E);
+ end if;
+ 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 Restriction_Check_Required (No_Streams) then
+ if Has_Stream (T) then
+ Check_Restriction (No_Streams, N);
+ end if;
+ end if;
+
+ -- Deal with predicate check before we start to do major rewriting.
+ -- it is OK to initialize and then check the initialized value, since
+ -- the object goes out of scope if we get a predicate failure. Note
+ -- that we do this in the analyzer and not the expander because the
+ -- analyzer does some substantial rewriting in some cases.
+
+ -- We need a predicate check if the type has predicates, and if either
+ -- there is an initializing expression, or for default initialization
+ -- when we have at least one case of an explicit default initial value.
+
+ if not Suppress_Assignment_Checks (N)
+ and then Present (Predicate_Function (T))
+ and then
+ (Present (E)
+ or else
+ Is_Partially_Initialized_Type (T, Include_Implicit => False))
+ then
+ Insert_After (N,
+ Make_Predicate_Check (T, New_Occurrence_Of (Id, Loc)));
+ end if;
+
+ -- Case of unconstrained type
+
+ if Is_Indefinite_Subtype (T) then
+
+ -- In SPARK, a declaration of unconstrained type is allowed
+ -- only for constants of type string.
+
+ if Is_String_Type (T) and then not Constant_Present (N) then
+ Check_SPARK_Restriction
+ ("declaration of object of unconstrained type not allowed",
+ N);
+ end if;
+
+ -- 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));
+
+ if Is_Record_Type (T) and then Has_Discriminants (T) then
+ Error_Msg_N
+ ("\provide initial value or explicit discriminant values",
+ Object_Definition (N));
+
+ Error_Msg_NE
+ ("\or give default discriminant values for type&",
+ Object_Definition (N), T);
+
+ elsif Is_Array_Type (T) then
+ Error_Msg_N
+ ("\provide initial value or explicit array bounds",
+ Object_Definition (N));
+ end if;
+ 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
+ -- Check restrictions in Ada 83
+
+ if not Constant_Present (N) then
+
+ -- Unconstrained variables not allowed in Ada 83 mode
+
+ 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);
+
+ -- In case of class-wide interface object declarations we delay
+ -- the generation of the equivalent record type declarations until
+ -- its expansion because there are cases in they are not required.
+
+ elsif Is_Interface (T) then
+ null;
+
+ 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;
+
+ -- If the type is limited unconstrained with defaulted discriminants and
+ -- there is no expression, then the object is constrained by the
+ -- defaults, so it is worthwhile building the corresponding subtype.
+
+ elsif (Is_Limited_Record (T) or else Is_Concurrent_Type (T))
+ and then not Is_Constrained (T)
+ and then Has_Discriminants (T)
+ then
+ if No (E) then
+ Act_T := Build_Default_Subtype (T, N);
+ else
+ -- Ada 2005: a limited object may be initialized by means of an
+ -- aggregate. If the type has default discriminants it has an
+ -- unconstrained nominal type, Its actual subtype will be obtained
+ -- from the aggregate, and not from the default discriminants.
+
+ Act_T := Etype (E);
+ end if;
+
+ Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
+
+ elsif Present (Underlying_Type (T))
+ and then not Is_Constrained (Underlying_Type (T))
+ and then Has_Discriminants (Underlying_Type (T))
+ and then Nkind (E) = N_Function_Call
+ and then Constant_Present (N)
+ then
+ -- The back-end has problems with constants of a discriminated type
+ -- with defaults, if the initial value is a function call. We
+ -- generate an intermediate temporary for the result of the call.
+ -- It is unclear why this should make it acceptable to gcc. ???
+
+ Remove_Side_Effects (E);
+
+ -- If this is a constant declaration of an unconstrained type and
+ -- the initialization is an aggregate, we can use the subtype of the
+ -- aggregate for the declared entity because it is immutable.
+
+ elsif not Is_Constrained (T)
+ and then Has_Discriminants (T)
+ and then Constant_Present (N)
+ and then not Has_Unchecked_Union (T)
+ and then Nkind (E) = N_Aggregate
+ then
+ Act_T := Etype (E);
+ end if;
+
+ -- Check No_Wide_Characters restriction
+
+ Check_Wide_Character_Restriction (T, Object_Definition (N));
+
+ -- Indicate this is not set in source. Certainly true for constants, and
+ -- true for variables so far (will be reset for a variable if and when
+ -- we encounter a modification in the source).
+
+ Set_Never_Set_In_Source (Id, True);
+
+ -- Now establish the proper kind and type of the object
+
+ if Constant_Present (N) then
+ Set_Ekind (Id, E_Constant);
+ 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;
+
+ -- Set Has_Initial_Value if initializing expression present. Note
+ -- that if there is no initializing expression, we leave the state
+ -- of this flag unchanged (usually it will be False, but notably in
+ -- the case of exception choice variables, it will already be true).
+
+ if Present (E) then
+ Set_Has_Initial_Value (Id, True);
+ end if;
+ end if;
+
+ -- Initialize alignment and size and capture alignment setting
+
+ Init_Alignment (Id);
+ Init_Esize (Id);
+ Set_Optimize_Alignment_Flags (Id);
+
+ -- Deal with aliased case
+
+ if Aliased_Present (N) then
+ Set_Is_Aliased (Id);
+
+ -- If the object is aliased and the type is unconstrained with
+ -- defaulted discriminants and there is no expression, then the
+ -- object is constrained by the defaults, so it is worthwhile
+ -- building the corresponding subtype.
+
+ -- Ada 2005 (AI-363): If the aliased object is discriminated and
+ -- unconstrained, then only establish an actual subtype if the
+ -- nominal subtype is indefinite. In definite cases the object is
+ -- unconstrained in Ada 2005.
+
+ if No (E)
+ and then Is_Record_Type (T)
+ and then not Is_Constrained (T)
+ and then Has_Discriminants (T)
+ and then (Ada_Version < Ada_2005 or else Is_Indefinite_Subtype (T))
+ then
+ Set_Actual_Subtype (Id, Build_Default_Subtype (T, N));
+ end if;
+ end if;
+
+ -- Now we can set the type of the object
+
+ Set_Etype (Id, Act_T);
+
+ -- Object is marked to be treated as volatile if type is volatile and
+ -- we clear the Current_Value setting that may have been set above.
+
+ if Treat_As_Volatile (Etype (Id)) then
+ Set_Treat_As_Volatile (Id);
+ Set_Current_Value (Id, Empty);
+ end if;
+
+ -- Deal with controlled types
+
+ 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;
+ end if;
+
+ if Has_Task (Etype (Id)) then
+ Check_Restriction (No_Tasking, N);
+
+ -- Deal with counting max tasks
+
+ -- Nothing to do if inside a generic
+
+ if Inside_A_Generic then
+ null;
+
+ -- If library level entity, then count tasks
+
+ elsif Is_Library_Level_Entity (Id) then
+ Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
+
+ -- If not library level entity, then indicate we don't know max
+ -- tasks and also check task hierarchy restriction and blocking
+ -- operation (since starting a task is definitely blocking!)
+
+ else
+ Check_Restriction (Max_Tasks, N);
+ Check_Restriction (No_Task_Hierarchy, N);
+ Check_Potentially_Blocking_Operation (N);
+ end if;
+
+ -- A rather specialized test. If we see two tasks being declared
+ -- of the same type in the same object declaration, and the task
+ -- has an entry with an address clause, we know that program error
+ -- will be raised at run time since we can't have two tasks with
+ -- entries at the same address.
+
+ if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
+ declare
+ E : Entity_Id;
+
+ begin
+ E := First_Entity (Etype (Id));
+ while Present (E) loop
+ if Ekind (E) = E_Entry
+ and then Present (Get_Attribute_Definition_Clause
+ (E, Attribute_Address))
+ then
+ Error_Msg_N
+ ("??more than one task with same entry address", N);
+ Error_Msg_N
+ ("\??Program_Error will be raised at run time", N);
+ Insert_Action (N,
+ Make_Raise_Program_Error (Loc,
+ Reason => PE_Duplicated_Entry_Address));
+ exit;
+ end if;
+
+ Next_Entity (E);
+ end loop;
+ end;
+ end if;
+ end if;
+
+ -- Some simple constant-propagation: if the expression is a constant
+ -- string initialized with a literal, share the literal. This avoids
+ -- a run-time copy.
+
+ if Present (E)
+ and then Is_Entity_Name (E)
+ and then Ekind (Entity (E)) = E_Constant
+ and then Base_Type (Etype (E)) = Standard_String
+ then
+ declare
+ Val : constant Node_Id := Constant_Value (Entity (E));
+ begin
+ if Present (Val)
+ and then Nkind (Val) = N_String_Literal
+ then
+ Rewrite (E, New_Copy (Val));
+ end if;
+ end;
+ end if;
+
+ -- Another optimization: if the nominal subtype is unconstrained and
+ -- the expression is a function call that returns an unconstrained
+ -- type, rewrite the declaration as a renaming of the result of the
+ -- call. The exceptions below are cases where the copy is expected,
+ -- either by the back end (Aliased case) or by the semantics, as for
+ -- initializing controlled types or copying tags for classwide types.
+
+ if Present (E)
+ and then Nkind (E) = N_Explicit_Dereference
+ and then Nkind (Original_Node (E)) = N_Function_Call
+ and then not Is_Library_Level_Entity (Id)
+ and then not Is_Constrained (Underlying_Type (T))
+ and then not Is_Aliased (Id)
+ and then not Is_Class_Wide_Type (T)
+ and then not Is_Controlled (T)
+ and then not Has_Controlled_Component (Base_Type (T))
+ and then Expander_Active
+ then
+ Rewrite (N,
+ Make_Object_Renaming_Declaration (Loc,
+ Defining_Identifier => Id,
+ Access_Definition => Empty,
+ Subtype_Mark => New_Occurrence_Of
+ (Base_Type (Etype (Id)), Loc),
+ Name => E));
+
+ Set_Renamed_Object (Id, E);
+
+ -- Force generation of debugging information for the constant and for
+ -- the renamed function call.
+
+ Set_Debug_Info_Needed (Id);
+ Set_Debug_Info_Needed (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);
+
+ -- Deal with setting In_Private_Part flag if in private part
+
+ if Ekind (Scope (Id)) = E_Package
+ and then In_Private_Part (Scope (Id))
+ then
+ Set_In_Private_Part (Id);
+ end if;
+
+ -- Check for violation of No_Local_Timing_Events
+
+ if Restriction_Check_Required (No_Local_Timing_Events)
+ and then not Is_Library_Level_Entity (Id)
+ and then Is_RTE (Etype (Id), RE_Timing_Event)
+ then
+ Check_Restriction (No_Local_Timing_Events, N);
+ end if;
+
+ <<Leave>>
+ if Has_Aspects (N) then
+ Analyze_Aspect_Specifications (N, Id);
+ end if;
+
+ Analyze_Dimension (N);
+ 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_Private_Extension_Declaration --
+ -------------------------------------------
+
+ procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
+ T : constant Entity_Id := Defining_Identifier (N);
+ Indic : constant Node_Id := Subtype_Indication (N);
+ Parent_Type : Entity_Id;
+ Parent_Base : Entity_Id;
+
+ begin
+ -- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
+
+ if Is_Non_Empty_List (Interface_List (N)) then
+ declare
+ Intf : Node_Id;
+ T : Entity_Id;
+
+ begin
+ Intf := First (Interface_List (N));
+ while Present (Intf) loop
+ T := Find_Type_Of_Subtype_Indic (Intf);
+
+ Diagnose_Interface (Intf, T);
+ Next (Intf);
+ end loop;
+ end;
+ end if;
+
+ Generate_Definition (T);
+
+ -- For other than Ada 2012, just enter the name in the current scope
+
+ if Ada_Version < Ada_2012 then
+ Enter_Name (T);
+
+ -- Ada 2012 (AI05-0162): Enter the name in the current scope handling
+ -- case of private type that completes an incomplete type.
+
+ else
+ declare
+ Prev : Entity_Id;
+
+ begin
+ Prev := Find_Type_Name (N);
+
+ pragma Assert (Prev = T
+ or else (Ekind (Prev) = E_Incomplete_Type
+ and then Present (Full_View (Prev))
+ and then Full_View (Prev) = T));
+ end;
+ end if;
+
+ 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);
+ goto Leave;
+
+ elsif not Is_Tagged_Type (Parent_Type) then
+ Error_Msg_N
+ ("parent of type extension must be a tagged type ", Indic);
+ goto Leave;
+
+ elsif Ekind_In (Parent_Type, E_Void, E_Incomplete_Type) then
+ Error_Msg_N ("premature derivation of incomplete type", Indic);
+ goto Leave;
+
+ elsif Is_Concurrent_Type (Parent_Type) then
+ Error_Msg_N
+ ("parent type of a private extension cannot be "
+ & "a synchronized tagged type (RM 3.9.1 (3/1))", N);
+
+ Set_Etype (T, Any_Type);
+ Set_Ekind (T, E_Limited_Private_Type);
+ Set_Private_Dependents (T, New_Elmt_List);
+ Set_Error_Posted (T);
+ goto Leave;
+ 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);
+ goto Leave;
+ end if;
+
+ if (not Is_Package_Or_Generic_Package (Current_Scope)
+ and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
+ or else In_Private_Part (Current_Scope)
+
+ then
+ Error_Msg_N ("invalid context for private extension", N);
+ end if;
+
+ -- Set common attributes
+
+ Set_Is_Pure (T, Is_Pure (Current_Scope));
+ Set_Scope (T, Current_Scope);
+ Set_Ekind (T, E_Record_Type_With_Private);
+ Init_Size_Align (T);
+
+ Set_Etype (T, Parent_Base);
+ Set_Has_Task (T, Has_Task (Parent_Base));
+
+ Set_Convention (T, Convention (Parent_Type));
+ Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
+ Set_Is_First_Subtype (T);
+ Make_Class_Wide_Type (T);
+
+ if Unknown_Discriminants_Present (N) then
+ Set_Discriminant_Constraint (T, No_Elist);
+ end if;
+
+ Build_Derived_Record_Type (N, Parent_Type, T);
+
+ -- Propagate inherited invariant information. The new type has
+ -- invariants, if the parent type has inheritable invariants,
+ -- and these invariants can in turn be inherited.
+
+ if Has_Inheritable_Invariants (Parent_Type) then
+ Set_Has_Inheritable_Invariants (T);
+ Set_Has_Invariants (T);
+ end if;
+
+ -- Ada 2005 (AI-443): Synchronized private extension or a rewritten
+ -- synchronized formal derived type.
+
+ if Ada_Version >= Ada_2005
+ and then Synchronized_Present (N)
+ then
+ Set_Is_Limited_Record (T);
+
+ -- Formal derived type case
+
+ if Is_Generic_Type (T) then
+
+ -- The parent must be a tagged limited type or a synchronized
+ -- interface.
+
+ if (not Is_Tagged_Type (Parent_Type)
+ or else not Is_Limited_Type (Parent_Type))
+ and then
+ (not Is_Interface (Parent_Type)
+ or else not Is_Synchronized_Interface (Parent_Type))
+ then
+ Error_Msg_NE ("parent type of & must be tagged limited " &
+ "or synchronized", N, T);
+ end if;
+
+ -- The progenitors (if any) must be limited or synchronized
+ -- interfaces.
+
+ if Present (Interfaces (T)) then
+ declare
+ Iface : Entity_Id;
+ Iface_Elmt : Elmt_Id;
+
+ begin
+ Iface_Elmt := First_Elmt (Interfaces (T));
+ while Present (Iface_Elmt) loop
+ Iface := Node (Iface_Elmt);
+
+ if not Is_Limited_Interface (Iface)
+ and then not Is_Synchronized_Interface (Iface)
+ then
+ Error_Msg_NE ("progenitor & must be limited " &
+ "or synchronized", N, Iface);
+ end if;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end;
+ end if;
+
+ -- Regular derived extension, the parent must be a limited or
+ -- synchronized interface.
+
+ else
+ if not Is_Interface (Parent_Type)
+ or else (not Is_Limited_Interface (Parent_Type)
+ and then
+ not Is_Synchronized_Interface (Parent_Type))
+ then
+ Error_Msg_NE
+ ("parent type of & must be limited interface", N, T);
+ end if;
+ end if;
+
+ -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
+ -- extension with a synchronized parent must be explicitly declared
+ -- synchronized, because the full view will be a synchronized type.
+ -- This must be checked before the check for limited types below,
+ -- to ensure that types declared limited are not allowed to extend
+ -- synchronized interfaces.
+
+ elsif Is_Interface (Parent_Type)
+ and then Is_Synchronized_Interface (Parent_Type)
+ and then not Synchronized_Present (N)
+ then
+ Error_Msg_NE
+ ("private extension of& must be explicitly synchronized",
+ N, Parent_Type);
+
+ elsif Limited_Present (N) then
+ Set_Is_Limited_Record (T);
+
+ if not Is_Limited_Type (Parent_Type)
+ and then
+ (not Is_Interface (Parent_Type)
+ or else not Is_Limited_Interface (Parent_Type))
+ then
+ Error_Msg_NE ("parent type& of limited extension must be limited",
+ N, Parent_Type);
+ end if;
+ end if;
+
+ <<Leave>>
+ if Has_Aspects (N) then
+ Analyze_Aspect_Specifications (N, T);
+ end if;
+ end Analyze_Private_Extension_Declaration;
+
+ ---------------------------------
+ -- Analyze_Subtype_Declaration --
+ ---------------------------------
+
+ procedure Analyze_Subtype_Declaration
+ (N : Node_Id;
+ Skip : Boolean := False)
+ 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 Skip
+ or else (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');
+
+ -- Class-wide equivalent types of records with unknown discriminants
+ -- involve the generation of an itype which serves as the private view
+ -- of a constrained record subtype. In such cases the base type of the
+ -- current subtype we are processing is the private itype. Use the full
+ -- of the private itype when decorating various attributes.
+
+ if Is_Itype (T)
+ and then Is_Private_Type (T)
+ and then Present (Full_View (T))
+ then
+ T := Full_View (T);
+ end if;
+
+ -- Inherit common attributes
+
+ Set_Is_Volatile (Id, Is_Volatile (T));
+ Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
+ Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
+ Set_Convention (Id, Convention (T));
+
+ -- If ancestor has predicates then so does the subtype, and in addition
+ -- we must delay the freeze to properly arrange predicate inheritance.
+
+ -- The Ancestor_Type test is a big kludge, there seem to be cases in
+ -- which T = ID, so the above tests and assignments do nothing???
+
+ if Has_Predicates (T)
+ or else (Present (Ancestor_Subtype (T))
+ and then Has_Predicates (Ancestor_Subtype (T)))
+ then
+ Set_Has_Predicates (Id);
+ Set_Has_Delayed_Freeze (Id);
+ end if;
+
+ -- Subtype of Boolean cannot have a constraint in SPARK
+
+ if Is_Boolean_Type (T)
+ and then Nkind (Subtype_Indication (N)) = N_Subtype_Indication
+ then
+ Check_SPARK_Restriction
+ ("subtype of Boolean cannot have constraint", N);
+ end if;
+
+ if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
+ declare
+ Cstr : constant Node_Id := Constraint (Subtype_Indication (N));
+ One_Cstr : Node_Id;
+ Low : Node_Id;
+ High : Node_Id;
+
+ begin
+ if Nkind (Cstr) = N_Index_Or_Discriminant_Constraint then
+ One_Cstr := First (Constraints (Cstr));
+ while Present (One_Cstr) loop
+
+ -- Index or discriminant constraint in SPARK must be a
+ -- subtype mark.
+
+ if not
+ Nkind_In (One_Cstr, N_Identifier, N_Expanded_Name)
+ then
+ Check_SPARK_Restriction
+ ("subtype mark required", One_Cstr);
+
+ -- String subtype must have a lower bound of 1 in SPARK.
+ -- Note that we do not need to test for the non-static case
+ -- here, since that was already taken care of in
+ -- Process_Range_Expr_In_Decl.
+
+ elsif Base_Type (T) = Standard_String then
+ Get_Index_Bounds (One_Cstr, Low, High);
+
+ if Is_OK_Static_Expression (Low)
+ and then Expr_Value (Low) /= 1
+ then
+ Check_SPARK_Restriction
+ ("String subtype must have lower bound of 1", N);
+ end if;
+ end if;
+
+ Next (One_Cstr);
+ end loop;
+ end if;
+ end;
+ end if;
+
+ -- 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));
+
+ -- Subtype of unconstrained array without constraint is not allowed
+ -- in SPARK.
+
+ if Is_Array_Type (T)
+ and then not Is_Constrained (T)
+ then
+ Check_SPARK_Restriction
+ ("subtype of unconstrained array must have constraint", N);
+ end if;
+
+ 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_Is_Known_Valid (Id, Is_Known_Valid (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_Is_Known_Valid (Id, Is_Known_Valid (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_Is_Known_Valid (Id, Is_Known_Valid (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_Is_Known_Valid (Id, Is_Known_Valid (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_Is_Known_Valid (Id, Is_Known_Valid (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_Implicit_Dereference
+ (Id, Has_Implicit_Dereference (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_Type (Id, Is_Abstract_Type (T));
+ Set_Direct_Primitive_Operations
+ (Id, Direct_Primitive_Operations (T));
+ Set_Class_Wide_Type (Id, Class_Wide_Type (T));
+
+ if Is_Interface (T) then
+ Set_Is_Interface (Id);
+ Set_Is_Limited_Interface (Id, Is_Limited_Interface (T));
+ end if;
+ 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_Implicit_Dereference
+ (Id, Has_Implicit_Dereference (T));
+ Set_Has_Unknown_Discriminants
+ (Id, Has_Unknown_Discriminants (T));
+ Set_Known_To_Have_Preelab_Init
+ (Id, Known_To_Have_Preelab_Init (T));
+
+ if Is_Tagged_Type (T) then
+ Set_Is_Tagged_Type (Id);
+ Set_Is_Abstract_Type (Id, Is_Abstract_Type (T));
+ Set_Class_Wide_Type (Id, Class_Wide_Type (T));
+ Set_Direct_Primitive_Operations (Id,
+ Direct_Primitive_Operations (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
+ -- generates spurious errors about missing components ???
+
+ -- Set_Has_Discriminants (Id);
+ end if;
+
+ Prepare_Private_Subtype_Completion (Id, N);
+
+ -- If this is the subtype of a constrained private type with
+ -- discriminants that has got a full view and we also have
+ -- built a completion just above, show that the completion
+ -- is a clone of the full view to the back-end.
+
+ if Has_Discriminants (T)
+ and then not Has_Unknown_Discriminants (T)
+ and then not Is_Empty_Elmt_List (Discriminant_Constraint (T))
+ and then Present (Full_View (T))
+ and then Present (Full_View (Id))
+ then
+ Set_Cloned_Subtype (Full_View (Id), Full_View (T));
+ end if;
+
+ when Access_Kind =>
+ Set_Ekind (Id, E_Access_Subtype);
+ Set_Is_Constrained (Id, Is_Constrained (T));
+ Set_Is_Access_Constant
+ (Id, Is_Access_Constant (T));
+ Set_Directly_Designated_Type
+ (Id, Designated_Type (T));
+ Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
+
+ -- A Pure library_item must not contain the declaration of a
+ -- named access type, except within a subprogram, generic
+ -- subprogram, task unit, or protected unit, or if it has
+ -- a specified Storage_Size of zero (RM05-10.2.1(15.4-15.5)).
+
+ if Comes_From_Source (Id)
+ and then In_Pure_Unit
+ and then not In_Subprogram_Task_Protected_Unit
+ and then not No_Pool_Assigned (Id)
+ 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_Is_Tagged_Type (Id, Is_Tagged_Type (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;
+
+ when E_Incomplete_Type =>
+ if Ada_Version >= Ada_2005 then
+
+ -- In Ada 2005 an incomplete type can be explicitly tagged:
+ -- propagate indication.
+
+ Set_Ekind (Id, E_Incomplete_Subtype);
+ Set_Is_Tagged_Type (Id, Is_Tagged_Type (T));
+ Set_Private_Dependents (Id, New_Elmt_List);
+
+ -- Ada 2005 (AI-412): Decorate an incomplete subtype of an
+ -- incomplete type visible through a limited with clause.
+
+ if From_With_Type (T)
+ and then Present (Non_Limited_View (T))
+ then
+ Set_From_With_Type (Id);
+ Set_Non_Limited_View (Id, Non_Limited_View (T));
+
+ -- Ada 2005 (AI-412): Add the regular incomplete subtype
+ -- to the private dependents of the original incomplete
+ -- type for future transformation.
+
+ else
+ Append_Elmt (Id, Private_Dependents (T));
+ end if;
+
+ -- If the subtype name denotes an incomplete type an error
+ -- was already reported by Process_Subtype.
+
+ else
+ Set_Etype (Id, Any_Type);
+ end if;
+
+ when others =>
+ raise Program_Error;
+ end case;
+ end if;
+
+ if Etype (Id) = Any_Type then
+ goto Leave;
+ end if;
+
+ -- Some common processing on all types
+
+ Set_Size_Info (Id, T);
+ Set_First_Rep_Item (Id, First_Rep_Item (T));
+
+ -- If the parent type is a generic actual, so is the subtype. This may
+ -- happen in a nested instance. Why Comes_From_Source test???
+
+ if not Comes_From_Source (N) then
+ Set_Is_Generic_Actual_Type (Id, Is_Generic_Actual_Type (T));
+ end if;
+
+ T := Etype (Id);
+
+ Set_Is_Immediately_Visible (Id, True);
+ Set_Depends_On_Private (Id, Has_Private_Component (T));
+ Set_Is_Descendent_Of_Address (Id, Is_Descendent_Of_Address (T));
+
+ if Is_Interface (T) then
+ Set_Is_Interface (Id);
+ end if;
+
+ 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 this is a generic actual subtype for a synchronized type,
+ -- the primitive operations are those of the corresponding record
+ -- for which there is a separate subtype declaration.
+
+ if Is_Concurrent_Type (Id) then
+ null;
+ elsif 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))));
+
+ -- In the array case, check compatibility for each index
+
+ 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???
+
+ declare
+ Subt_Index : Node_Id := First_Index (Id);
+ Target_Index : Node_Id :=
+ First_Index (Etype
+ (Subtype_Mark (Subtype_Indication (N))));
+ Has_Dyn_Chk : Boolean := Has_Dynamic_Range_Check (N);
+
+ begin
+ while Present (Subt_Index) loop
+ if ((Nkind (Subt_Index) = N_Identifier
+ and then Ekind (Entity (Subt_Index)) in Scalar_Kind)
+ or else Nkind (Subt_Index) = N_Subtype_Indication)
+ and then
+ Nkind (Scalar_Range (Etype (Subt_Index))) = N_Range
+ then
+ declare
+ Target_Typ : constant Entity_Id :=
+ Etype (Target_Index);
+ begin
+ R_Checks :=
+ Get_Range_Checks
+ (Scalar_Range (Etype (Subt_Index)),
+ Target_Typ,
+ Etype (Subt_Index),
+ Defining_Identifier (N));
+
+ -- Reset Has_Dynamic_Range_Check on the subtype to
+ -- prevent elision of the index check due to a dynamic
+ -- check generated for a preceding index (needed since
+ -- Insert_Range_Checks tries to avoid generating
+ -- redundant checks on a given declaration).
+
+ Set_Has_Dynamic_Range_Check (N, False);
+
+ Insert_Range_Checks
+ (R_Checks,
+ N,
+ Target_Typ,
+ Sloc (Defining_Identifier (N)));
+
+ -- Record whether this index involved a dynamic check
+
+ Has_Dyn_Chk :=
+ Has_Dyn_Chk or else Has_Dynamic_Range_Check (N);
+ end;
+ end if;
+
+ Next_Index (Subt_Index);
+ Next_Index (Target_Index);
+ end loop;
+
+ -- Finally, mark whether the subtype involves dynamic checks
+
+ Set_Has_Dynamic_Range_Check (N, Has_Dyn_Chk);
+ end;
+ end if;
+ end if;
+
+ -- Make sure that generic actual types are properly frozen. The subtype
+ -- is marked as a generic actual type when the enclosing instance is
+ -- analyzed, so here we identify the subtype from the tree structure.
+
+ if Expander_Active
+ and then Is_Generic_Actual_Type (Id)
+ and then In_Instance
+ and then not Comes_From_Source (N)
+ and then Nkind (Subtype_Indication (N)) /= N_Subtype_Indication
+ and then Is_Frozen (T)
+ then
+ Freeze_Before (N, Id);
+ end if;
+
+ Set_Optimize_Alignment_Flags (Id);
+ Check_Eliminated (Id);
+
+ <<Leave>>
+ if Has_Aspects (N) then
+ Analyze_Aspect_Specifications (N, Id);
+ end if;
+
+ Analyze_Dimension (N);
+ 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));
+ Resolve (R, Entity (T));
+ else
+ Set_Error_Posted (R);
+ Set_Error_Posted (T);
+ end if;
+ end Analyze_Subtype_Indication;
+
+ --------------------------
+ -- 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;
+
+ -- Local Variables
+
+ Discr_Name : Node_Id;
+ Discr_Type : Entity_Id;
+
+ Dont_Care : Boolean;
+ Others_Present : Boolean := False;
+
+ pragma Warnings (Off, Dont_Care);
+ pragma Warnings (Off, Others_Present);
+ -- We don't care about the assigned values of any of these
+
+ -- Start of processing for Analyze_Variant_Part
+
+ begin
+ Discr_Name := Name (N);
+ Analyze (Discr_Name);
+
+ -- If Discr_Name bad, get out (prevent cascaded errors)
+
+ if Etype (Discr_Name) = Any_Type then
+ return;
+ end if;
+
+ -- Check invalid discriminant in variant part
+
+ 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, 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);
+ Component_Typ : constant Node_Id := Subtype_Indication (Component_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);
+
+ if not Nkind_In (Index, N_Identifier, N_Expanded_Name) then
+ Check_SPARK_Restriction ("subtype mark required", Index);
+ end if;
+
+ -- Add a subtype declaration for each index of private array type
+ -- declaration whose etype is also private. For example:
+
+ -- package Pkg is
+ -- type Index is private;
+ -- private
+ -- type Table is array (Index) of ...
+ -- end;
+
+ -- This is currently required by the expander for the internally
+ -- generated equality subprogram of records with variant parts in
+ -- which the etype of some component is such private type.
+
+ if Ekind (Current_Scope) = E_Package
+ and then In_Private_Part (Current_Scope)
+ and then Has_Private_Declaration (Etype (Index))
+ then
+ declare
+ Loc : constant Source_Ptr := Sloc (Def);
+ New_E : Entity_Id;
+ Decl : Entity_Id;
+
+ begin
+ New_E := Make_Temporary (Loc, 'T');
+ Set_Is_Internal (New_E);
+
+ Decl :=
+ Make_Subtype_Declaration (Loc,
+ Defining_Identifier => New_E,
+ Subtype_Indication =>
+ New_Occurrence_Of (Etype (Index), Loc));
+
+ Insert_Before (Parent (Def), Decl);
+ Analyze (Decl);
+ Set_Etype (Index, New_E);
+
+ -- If the index is a range the Entity attribute is not
+ -- available. Example:
+
+ -- package Pkg is
+ -- type T is private;
+ -- private
+ -- type T is new Natural;
+ -- Table : array (T(1) .. T(10)) of Boolean;
+ -- end Pkg;
+
+ if Nkind (Index) /= N_Range then
+ Set_Entity (Index, New_E);
+ end if;
+ end;
+ end if;
+
+ Make_Index (Index, P, Related_Id, Nb_Index);
+
+ -- Check error of subtype with predicate for index type
+
+ Bad_Predicated_Subtype_Use
+ ("subtype& has predicate, not allowed as index subtype",
+ Index, Etype (Index));
+
+ -- Move to next index
+
+ Next_Index (Index);
+ Nb_Index := Nb_Index + 1;
+ end loop;
+
+ -- Process subtype indication if one is present
+
+ if Present (Component_Typ) then
+ Element_Type := Process_Subtype (Component_Typ, P, Related_Id, 'C');
+
+ Set_Etype (Component_Typ, Element_Type);
+
+ if not Nkind_In (Component_Typ, N_Identifier, N_Expanded_Name) then
+ Check_SPARK_Restriction ("subtype mark required", Component_Typ);
+ end if;
+
+ -- Ada 2005 (AI-230): Access Definition case
+
+ else pragma Assert (Present (Access_Definition (Component_Def)));
+
+ -- Indicate that the anonymous access type is created by the
+ -- array type declaration.
+
+ Element_Type := Access_Definition
+ (Related_Nod => P,
+ N => Access_Definition (Component_Def));
+ Set_Is_Local_Anonymous_Access (Element_Type);
+
+ -- Propagate the parent. This field is needed if we have to generate
+ -- the master_id associated with an anonymous access to task type
+ -- component (see Expand_N_Full_Type_Declaration.Build_Master)
+
+ Set_Parent (Element_Type, Parent (T));
+
+ -- 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);
+ 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');
+
+ 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_Packed_Array_Type (Implicit_Base, Empty);
+ 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;
+
+ -- Common attributes for both cases
+
+ Set_Component_Type (Base_Type (T), Element_Type);
+ Set_Packed_Array_Type (T, Empty);
+
+ if Aliased_Present (Component_Definition (Def)) then
+ Check_SPARK_Restriction
+ ("aliased is not allowed", Component_Definition (Def));
+ Set_Has_Aliased_Components (Etype (T));
+ end if;
+
+ -- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
+ -- array type to ensure that objects of this type are initialized.
+
+ if Ada_Version >= Ada_2005
+ and then Can_Never_Be_Null (Element_Type)
+ then
+ Set_Can_Never_Be_Null (T);
+
+ if Null_Exclusion_Present (Component_Definition (Def))
+
+ -- No need to check itypes because in their case this check was
+ -- done at their point of creation
+
+ and then not Is_Itype (Element_Type)
+ then
+ Error_Msg_N
+ ("`NOT NULL` not allowed (null already excluded)",
+ 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;
+
+ -- A syntax error in the declaration itself may lead to an empty index
+ -- list, in which case do a minimal patch.
+
+ if No (First_Index (T)) then
+ Error_Msg_N ("missing index definition in array type declaration", T);
+
+ declare
+ Indexes : constant List_Id :=
+ New_List (New_Occurrence_Of (Any_Id, Sloc (T)));
+ begin
+ Set_Discrete_Subtype_Definitions (Def, Indexes);
+ Set_First_Index (T, First (Indexes));
+ return;
+ end;
+ 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 indexes 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_Type (Element_Type) then
+ Error_Msg_N
+ ("the type of a component cannot be abstract",
+ Subtype_Indication (Component_Def));
+ end if;
+
+ -- There may be an invariant declared for the component type, but
+ -- the construction of the component invariant checking procedure
+ -- takes place during expansion.
+ end Array_Type_Declaration;
+
+ ------------------------------------------------------
+ -- Replace_Anonymous_Access_To_Protected_Subprogram --
+ ------------------------------------------------------
+
+ function Replace_Anonymous_Access_To_Protected_Subprogram
+ (N : Node_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_Temporary (Loc, 'S');
+
+ Acc : Node_Id;
+ -- Access definition in declaration
+
+ Comp : Node_Id;
+ -- Object definition or formal definition with an access definition
+
+ Decl : Node_Id;
+ -- Declaration of anonymous access to subprogram type
+
+ Spec : Node_Id;
+ -- Original specification in access to subprogram
+
+ P : Node_Id;
+
+ begin
+ Set_Is_Internal (Anon);
+
+ case Nkind (N) is
+ when N_Component_Declaration |
+ N_Unconstrained_Array_Definition |
+ N_Constrained_Array_Definition =>
+ Comp := Component_Definition (N);
+ Acc := Access_Definition (Comp);
+
+ when N_Discriminant_Specification =>
+ Comp := Discriminant_Type (N);
+ Acc := Comp;
+
+ when N_Parameter_Specification =>
+ Comp := Parameter_Type (N);
+ Acc := Comp;
+
+ when N_Access_Function_Definition =>
+ Comp := Result_Definition (N);
+ Acc := Comp;
+
+ when N_Object_Declaration =>
+ Comp := Object_Definition (N);
+ Acc := Comp;
+
+ when N_Function_Specification =>
+ Comp := Result_Definition (N);
+ Acc := Comp;
+
+ when others =>
+ raise Program_Error;
+ end case;
+
+ Spec := Access_To_Subprogram_Definition (Acc);
+
+ Decl :=
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Anon,
+ Type_Definition => Copy_Separate_Tree (Spec));
+
+ Mark_Rewrite_Insertion (Decl);
+
+ -- In ASIS mode, analyze the profile on the original node, because
+ -- the separate copy does not provide enough links to recover the
+ -- original tree. Analysis is limited to type annotations, within
+ -- a temporary scope that serves as an anonymous subprogram to collect
+ -- otherwise useless temporaries and itypes.
+
+ if ASIS_Mode then
+ declare
+ Typ : constant Entity_Id := Make_Temporary (Loc, 'S');
+
+ begin
+ if Nkind (Spec) = N_Access_Function_Definition then
+ Set_Ekind (Typ, E_Function);
+ else
+ Set_Ekind (Typ, E_Procedure);
+ end if;
+
+ Set_Parent (Typ, N);
+ Set_Scope (Typ, Current_Scope);
+ Push_Scope (Typ);
+
+ Process_Formals (Parameter_Specifications (Spec), Spec);
+
+ if Nkind (Spec) = N_Access_Function_Definition then
+ if Nkind (Result_Definition (Spec)) = N_Access_Definition then
+ Find_Type (Subtype_Mark (Result_Definition (Spec)));
+ else
+ Find_Type (Result_Definition (Spec));
+ end if;
+ end if;
+
+ End_Scope;
+ end;
+ end if;
+
+ -- Insert the new declaration in the nearest enclosing scope. If the
+ -- node is a body and N is its return type, the declaration belongs in
+ -- the enclosing scope.
+
+ P := Parent (N);
+
+ if Nkind (P) = N_Subprogram_Body
+ and then Nkind (N) = N_Function_Specification
+ then
+ P := Parent (P);
+ end if;
+
+ while Present (P) and then not Has_Declarations (P) loop
+ P := Parent (P);
+ end loop;
+
+ pragma Assert (Present (P));
+
+ if Nkind (P) = N_Package_Specification then
+ Prepend (Decl, Visible_Declarations (P));
+ else
+ Prepend (Decl, Declarations (P));
+ end if;
+
+ -- Replace the anonymous type with an occurrence of the new declaration.
+ -- In all cases the rewritten node does not have the null-exclusion
+ -- attribute because (if present) it was already inherited by the
+ -- anonymous entity (Anon). Thus, in case of components we do not
+ -- inherit this attribute.
+
+ if Nkind (N) = N_Parameter_Specification then
+ Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
+ Set_Etype (Defining_Identifier (N), Anon);
+ Set_Null_Exclusion_Present (N, False);
+
+ elsif Nkind (N) = N_Object_Declaration then
+ Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
+ Set_Etype (Defining_Identifier (N), Anon);
+
+ elsif Nkind (N) = N_Access_Function_Definition then
+ Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
+
+ elsif Nkind (N) = N_Function_Specification then
+ Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
+ Set_Etype (Defining_Unit_Name (N), Anon);
+
+ else
+ Rewrite (Comp,
+ Make_Component_Definition (Loc,
+ Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
+ end if;
+
+ Mark_Rewrite_Insertion (Comp);
+
+ if Nkind_In (N, N_Object_Declaration, N_Access_Function_Definition) then
+ Analyze (Decl);
+
+ else
+ -- Temporarily remove the current scope (record or subprogram) from
+ -- the stack to add the new declarations to the enclosing scope.
+
+ Scope_Stack.Decrement_Last;
+ Analyze (Decl);
+ Set_Is_Itype (Anon);
+ Scope_Stack.Append (Curr_Scope);
+ end if;
+
+ Set_Ekind (Anon, E_Anonymous_Access_Protected_Subprogram_Type);
+ Set_Can_Use_Internal_Rep (Anon, not Always_Compatible_Rep_On_Target);
+ 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, and verify
+ -- that it is not redundant.
+
+ if Null_Exclusion_Present (Type_Definition (N)) then
+ Set_Can_Never_Be_Null (Derived_Type);
+
+ if Can_Never_Be_Null (Parent_Type)
+ and then False
+ then
+ Error_Msg_NE
+ ("`NOT NULL` not allowed (& already excludes null)",
+ N, Parent_Type);
+ end if;
+
+ elsif Can_Never_Be_Null (Parent_Type) then
+ Set_Can_Never_Be_Null (Derived_Type);
+ end if;
+
+ -- Note: we do not copy the Storage_Size_Variable, since we always go to
+ -- the root type for this information.
+
+ -- Apply range checks to discriminants for derived record case
+ -- ??? THIS CODE SHOULD NOT BE HERE REALLY.
+
+ Desig_Type := Designated_Type (Derived_Type);
+ if Is_Composite_Type (Desig_Type)
+ and then (not Is_Array_Type (Desig_Type))
+ and then Has_Discriminants (Desig_Type)
+ and then Base_Type (Desig_Type) /= Desig_Type
+ then
+ Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
+ Discr_Con_El := First_Elmt (Discr_Con_Elist);
+
+ Discr := First_Discriminant (Base_Type (Desig_Type));
+ while Present (Discr_Con_El) loop
+ Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
+ Next_Elmt (Discr_Con_El);
+ Next_Discriminant (Discr);
+ end loop;
+ end if;
+ end Build_Derived_Access_Type;
+
+ ------------------------------
+ -- Build_Derived_Array_Type --
+ ------------------------------
+
+ procedure Build_Derived_Array_Type
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id)
+ is
+ Loc : constant Source_Ptr := Sloc (N);
+ Tdef : constant Node_Id := Type_Definition (N);
+ Indic : constant Node_Id := Subtype_Indication (Tdef);
+ Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
+ Implicit_Base : Entity_Id;
+ New_Indic : Node_Id;
+
+ procedure Make_Implicit_Base;
+ -- If the parent subtype is constrained, the derived type is a subtype
+ -- of an implicit base type derived from the parent base.
+
+ ------------------------
+ -- Make_Implicit_Base --
+ ------------------------
+
+ procedure Make_Implicit_Base is
+ begin
+ Implicit_Base :=
+ Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
+
+ Set_Ekind (Implicit_Base, Ekind (Parent_Base));
+ Set_Etype (Implicit_Base, Parent_Base);
+
+ Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
+ Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
+
+ Set_Has_Delayed_Freeze (Implicit_Base, True);
+ end Make_Implicit_Base;
+
+ -- Start of processing for Build_Derived_Array_Type
+
+ begin
+ if not Is_Constrained (Parent_Type) then
+ if Nkind (Indic) /= N_Subtype_Indication then
+ Set_Ekind (Derived_Type, E_Array_Type);
+
+ Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
+ Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
+
+ Set_Has_Delayed_Freeze (Derived_Type, True);
+
+ else
+ Make_Implicit_Base;
+ Set_Etype (Derived_Type, Implicit_Base);
+
+ New_Indic :=
+ Make_Subtype_Declaration (Loc,
+ Defining_Identifier => Derived_Type,
+ Subtype_Indication =>
+ Make_Subtype_Indication (Loc,
+ Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
+ Constraint => Constraint (Indic)));
+
+ Rewrite (N, New_Indic);
+ Analyze (N);
+ end if;
+
+ else
+ if Nkind (Indic) /= N_Subtype_Indication then
+ Make_Implicit_Base;
+
+ Set_Ekind (Derived_Type, Ekind (Parent_Type));
+ Set_Etype (Derived_Type, Implicit_Base);
+ Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
+
+ else
+ Error_Msg_N ("illegal constraint on constrained type", Indic);
+ end if;
+ end if;
+
+ -- If parent type is not a derived type itself, and is declared in
+ -- closed scope (e.g. a subprogram), then we must explicitly introduce
+ -- the new type's concatenation operator since Derive_Subprograms
+ -- will not inherit the parent's operator. If the parent type is
+ -- unconstrained, the operator is of the unconstrained base type.
+
+ if Number_Dimensions (Parent_Type) = 1
+ and then not Is_Limited_Type (Parent_Type)
+ and then not Is_Derived_Type (Parent_Type)
+ and then not Is_Package_Or_Generic_Package
+ (Scope (Base_Type (Parent_Type)))
+ then
+ if not Is_Constrained (Parent_Type)
+ and then Is_Constrained (Derived_Type)
+ then
+ New_Concatenation_Op (Implicit_Base);
+ else
+ New_Concatenation_Op (Derived_Type);
+ end if;
+ end if;
+ end Build_Derived_Array_Type;
+
+ -----------------------------------
+ -- Build_Derived_Concurrent_Type --
+ -----------------------------------
+
+ procedure Build_Derived_Concurrent_Type
+ (N : Node_Id;
+ Parent_Type : Entity_Id;
+ Derived_Type : Entity_Id)
+ is
+ Loc : constant Source_Ptr := Sloc (N);
+
+ Corr_Record : constant Entity_Id := Make_Temporary (Loc, 'C');
+ Corr_Decl : Node_Id;
+ Corr_Decl_Needed : Boolean;
+ -- If the derived type has fewer discriminants than its parent, the
+ -- corresponding record is also a derived type, in order to account for
+ -- the bound discriminants. We create a full type declaration for it in
+ -- this case.
+
+ Constraint_Present : constant Boolean :=
+ Nkind (Subtype_Indication (Type_Definition (N))) =
+ N_Subtype_Indication;
+
+ D_Constraint : Node_Id;
+ New_Constraint : Elist_Id;
+ Old_Disc : Entity_Id;
+ New_Disc : Entity_Id;
+ New_N : Node_Id;
+
+ begin
+ Set_Stored_Constraint (Derived_Type, No_Elist);
+ Corr_Decl_Needed := False;
+ Old_Disc := Empty;
+
+ if Present (Discriminant_Specifications (N))
+ and then Constraint_Present
+ then
+ Old_Disc := First_Discriminant (Parent_Type);
+ New_Disc := First (Discriminant_Specifications (N));
+ while Present (New_Disc) and then Present (Old_Disc) loop
+ Next_Discriminant (Old_Disc);
+ Next (New_Disc);
+ end loop;
+ end if;
+
+ if Present (Old_Disc) and then Expander_Active then
+
+ -- The new type has fewer discriminants, so we need to create a new
+ -- corresponding record, which is derived from the corresponding
+ -- record of the parent, and has a stored constraint that captures
+ -- the values of the discriminant constraints. The corresponding
+ -- record is needed only if expander is active and code generation is
+ -- enabled.
+
+ -- The type declaration for the derived corresponding record has the
+ -- same discriminant part and constraints as the current declaration.
+ -- Copy the unanalyzed tree to build declaration.
+
+ Corr_Decl_Needed := True;
+ New_N := Copy_Separate_Tree (N);
+
+ Corr_Decl :=
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Corr_Record,
+ Discriminant_Specifications =>
+ Discriminant_Specifications (New_N),
+ Type_Definition =>
+ Make_Derived_Type_Definition (Loc,
+ Subtype_Indication =>
+ Make_Subtype_Indication (Loc,
+ Subtype_Mark =>
+ New_Occurrence_Of
+ (Corresponding_Record_Type (Parent_Type), Loc),
+ Constraint =>
+ Constraint
+ (Subtype_Indication (Type_Definition (New_N))))));
+ end if;
+
+ -- Copy Storage_Size and Relative_Deadline variables if task case
+
+ if Is_Task_Type (Parent_Type) then
+ Set_Storage_Size_Variable (Derived_Type,
+ Storage_Size_Variable (Parent_Type));
+ Set_Relative_Deadline_Variable (Derived_Type,
+ Relative_Deadline_Variable (Parent_Type));
+ end if;
+
+ if Present (Discriminant_Specifications (N)) then
+ Push_Scope (Derived_Type);
+ Check_Or_Process_Discriminants (N, Derived_Type);
+
+ if Constraint_Present then
+ New_Constraint :=
+ Expand_To_Stored_Constraint
+ (Parent_Type,
+ Build_Discriminant_Constraints
+ (Parent_Type,
+ Subtype_Indication (Type_Definition (N)), True));
+ end if;
+
+ End_Scope;
+
+ elsif Constraint_Present then
+
+ -- Build constrained subtype, copying the constraint, and derive
+ -- from it to create a derived constrained type.
+
+ declare
+ Loc : constant Source_Ptr := Sloc (N);
+ Anon : constant Entity_Id :=
+ Make_Defining_Identifier (Loc,
+ Chars => 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);
+ Analyze (Decl);
+
+ Rewrite (Subtype_Indication (Type_Definition (N)),
+ New_Occurrence_Of (Anon, Loc));
+ Set_Analyzed (Derived_Type, False);
+ Analyze (N);
+ return;
+ end;
+ end if;
+
+ -- By default, operations and private data are inherited from parent.
+ -- However, in the presence of bound discriminants, a new corresponding
+ -- record will be created, see below.
+
+ Set_Has_Discriminants
+ (Derived_Type, Has_Discriminants (Parent_Type));
+ Set_Corresponding_Record_Type
+ (Derived_Type, Corresponding_Record_Type (Parent_Type));
+
+ -- Is_Constrained is set according the parent subtype, but is set to
+ -- False if the derived type is declared with new discriminants.
+
+ Set_Is_Constrained
+ (Derived_Type,
+ (Is_Constrained (Parent_Type) or else Constraint_Present)
+ and then not Present (Discriminant_Specifications (N)));
+
+ if Constraint_Present then
+ if not Has_Discriminants (Parent_Type) then
+ Error_Msg_N ("untagged parent must have discriminants", N);
+
+ elsif Present (Discriminant_Specifications (N)) then
+
+ -- Verify that new discriminants are used to constrain old ones
+
+ D_Constraint :=
+ First
+ (Constraints
+ (Constraint (Subtype_Indication (Type_Definition (N)))));
+
+ Old_Disc := First_Discriminant (Parent_Type);
+
+ while Present (D_Constraint) loop
+ if Nkind (D_Constraint) /= N_Discriminant_Association then
+
+ -- Positional constraint. If it is a reference to a new
+ -- discriminant, it constrains the corresponding old one.
+
+ if Nkind (D_Constraint) = N_Identifier then
+ New_Disc := First_Discriminant (Derived_Type);
+ while Present (New_Disc) loop
+ exit when Chars (New_Disc) = Chars (D_Constraint);
+ Next_Discriminant (New_Disc);
+ end loop;
+
+ if Present (New_Disc) then
+ Set_Corresponding_Discriminant (New_Disc, Old_Disc);
+ end if;
+ end if;
+
+ Next_Discriminant (Old_Disc);
+
+ -- if this is a named constraint, search by name for the old
+ -- discriminants constrained by the new one.
+
+ elsif Nkind (Expression (D_Constraint)) = N_Identifier then
+
+ -- Find new discriminant with that name
+
+ New_Disc := First_Discriminant (Derived_Type);
+ while Present (New_Disc) loop
+ exit when
+ Chars (New_Disc) = Chars (Expression (D_Constraint));
+ Next_Discriminant (New_Disc);
+ end loop;
+
+ if Present (New_Disc) then
+
+ -- Verify that new discriminant renames some discriminant
+ -- of the parent type, and associate the new discriminant
+ -- with one or more old ones that it renames.
+
+ declare
+ Selector : Node_Id;
+
+ begin
+ Selector := First (Selector_Names (D_Constraint));
+ while Present (Selector) loop
+ Old_Disc := First_Discriminant (Parent_Type);
+ while Present (Old_Disc) loop
+ exit when Chars (Old_Disc) = Chars (Selector);
+ Next_Discriminant (Old_Disc);
+ end loop;
+
+ if Present (Old_Disc) then
+ Set_Corresponding_Discriminant
+ (New_Disc, Old_Disc);
+ end if;
+
+ Next (Selector);
+ end loop;
+ end;
+ end if;
+ end if;
+
+ Next (D_Constraint);
+ end loop;
+
+ New_Disc := First_Discriminant (Derived_Type);
+ while Present (New_Disc) loop
+ if No (Corresponding_Discriminant (New_Disc)) then
+ Error_Msg_NE
+ ("new discriminant& must constrain old one", N, New_Disc);
+
+ elsif not
+ Subtypes_Statically_Compatible
+ (Etype (New_Disc),
+ Etype (Corresponding_Discriminant (New_Disc)))
+ then
+ Error_Msg_NE
+ ("& not statically compatible with parent discriminant",
+ N, New_Disc);
+ end if;
+
+ Next_Discriminant (New_Disc);
+ end loop;
+ end if;
+
+ elsif Present (Discriminant_Specifications (N)) then
+ Error_Msg_N
+ ("missing discriminant constraint in untagged derivation", N);
+ end if;
+
+ -- The entity chain of the derived type includes the new discriminants
+ -- but shares operations with the parent.
+
+ 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);
+
+ if Corr_Decl_Needed then
+ Set_Stored_Constraint (Derived_Type, New_Constraint);
+ Insert_After (N, Corr_Decl);
+ Analyze (Corr_Decl);
+ Set_Corresponding_Record_Type (Derived_Type, Corr_Record);
+ end if;
+ 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_]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 Is_Standard_Character_Type (Parent_Type) 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
+ if Nkind (Indic) /= N_Subtype_Indication then
+ 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));
+ else
+
+ -- Analyze subtype indication and verify compatibility
+ -- with parent type.
+
+ if Base_Type (Process_Subtype (Indic, N)) /=
+ Base_Type (Parent_Type)
+ then
+ Error_Msg_N
+ ("illegal constraint for formal discrete type", N);
+ end if;
+ end if;
+ end;
+
+ else
+ -- If a constraint is present, analyze the bounds to catch
+ -- premature usage of the derived literals.
+
+ if Nkind (Indic) = N_Subtype_Indication
+ and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
+ then
+ Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
+ Analyze (High_Bound (Range_Expression (Constraint (Indic))));
+ end if;
+
+ -- Introduce an implicit base type for the derived type even if there
+ -- is no constraint attached to it, since this seems closer to the
+ -- Ada semantics. Build a full type declaration tree for the derived
+ -- type using the implicit base type as the defining identifier. The
+ -- build a subtype declaration tree which applies the constraint (if
+ -- any) have it replace the derived type declaration.
+
+ Literal := First_Literal (Parent_Type);
+ Literals_List := New_List;
+ while Present (Literal)
+ and then Ekind (Literal) = E_Enumeration_Literal
+ loop
+ -- Literals of the derived type have the same representation as
+ -- those of the parent type, but this representation can be
+ -- overridden by an explicit representation clause. Indicate
+ -- that there is no explicit representation given yet. These
+ -- derived literals are implicit operations of the new type,
+ -- and can be overridden by explicit ones.
+
+ if Nkind (Literal) = N_Defining_Character_Literal then
+ New_Lit :=
+ Make_Defining_Character_Literal (Loc, Chars (Literal));
+ else
+ New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
+ end if;
+
+ Set_Ekind (New_Lit, E_Enumeration_Literal);
+ Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
+ Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
+ Set_Enumeration_Rep_Expr (New_Lit, Empty);
+ Set_Alias (New_Lit, Literal);
+ Set_Is_Known_Valid (New_Lit, True);
+
+ Append (New_Lit, Literals_List);
+ Next_Literal (Literal);
+ end loop;
+
+ Implicit_Base :=
+ Make_Defining_Identifier (Sloc (Derived_Type),
+ Chars => 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));
+
+ -- Copy other flags from parent type
+
+ Set_Has_Non_Standard_Rep
+ (Implicit_Base, Has_Non_Standard_Rep
+ (Parent_Type));
+ Set_Has_Pragma_Ordered
+ (Implicit_Base, Has_Pragma_Ordered
+ (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 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);
+
+ -- 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_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
+ Set_Parent (Implicit_Base, Parent (Derived_Type));
+ Set_Is_Known_Valid (Implicit_Base, Is_Known_Valid (Parent_Base));
+
+ -- Set RM Size for discrete type or decimal fixed-point type
+ -- Ordinary fixed-point is excluded, why???
+
+ if Is_Discrete_Type (Parent_Base)
+ or else Is_Decimal_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 Process_Subtype call 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;
+
+ Set_Is_Known_Valid (Derived_Type, Is_Known_Valid (Parent_Type));
+ end if;
+
+ Set_Is_Descendent_Of_Address (Derived_Type,
+ Is_Descendent_Of_Address (Parent_Type));
+ Set_Is_Descendent_Of_Address (Implicit_Base,
+ Is_Descendent_Of_Address (Parent_Type));
+
+ -- 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));
+
+ Set_Is_Known_Valid
+ (Implicit_Base, Is_Known_Valid (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_Float_Rep (Implicit_Base, Float_Rep (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.
+
+ -- There is a further complication: actually *some* representation
+ -- clauses can affect the implicit base type. Namely, attribute
+ -- definition clauses for stream-oriented attributes need to set the
+ -- corresponding TSS entries on the base type, and this normally cannot
+ -- be done after the base type is frozen, so the circuitry in
+ -- Sem_Ch13.New_Stream_Subprogram must account for this possibility and
+ -- not use Set_TSS in this case.
+
+ 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
+ Loc : constant Source_Ptr := Sloc (N);
+ 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 not Is_Standard_Character_Type (Parent_Type)
+ 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
+ Full_P := Full_View (Parent_Type);
+
+ -- A type extension of a type with unknown discriminants is an
+ -- indefinite type that the back-end cannot handle directly.
+ -- We treat it as a private type, and build a completion that is
+ -- derived from the full view of the parent, and hopefully has
+ -- known discriminants.
+
+ -- If the full view of the parent type has an underlying record view,
+ -- use it to generate the underlying record view of this derived type
+ -- (required for chains of derivations with unknown discriminants).
+
+ -- Minor optimization: we avoid the generation of useless underlying
+ -- record view entities if the private type declaration has unknown
+ -- discriminants but its corresponding full view has no
+ -- discriminants.
+
+ if Has_Unknown_Discriminants (Parent_Type)
+ and then Present (Full_P)
+ and then (Has_Discriminants (Full_P)
+ or else Present (Underlying_Record_View (Full_P)))
+ and then not In_Open_Scopes (Par_Scope)
+ and then Expander_Active
+ then
+ declare
+ Full_Der : constant Entity_Id := Make_Temporary (Loc, 'T');
+ New_Ext : constant Node_Id :=
+ Copy_Separate_Tree
+ (Record_Extension_Part (Type_Definition (N)));
+ Decl : Node_Id;
+
+ begin
+ Build_Derived_Record_Type
+ (N, Parent_Type, Derived_Type, Derive_Subps);
+
+ -- Build anonymous completion, as a derivation from the full
+ -- view of the parent. This is not a completion in the usual
+ -- sense, because the current type is not private.
+
+ Decl :=
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Full_Der,
+ Type_Definition =>
+ Make_Derived_Type_Definition (Loc,
+ Subtype_Indication =>
+ New_Copy_Tree
+ (Subtype_Indication (Type_Definition (N))),
+ Record_Extension_Part => New_Ext));
+
+ -- If the parent type has an underlying record view, use it
+ -- here to build the new underlying record view.
+
+ if Present (Underlying_Record_View (Full_P)) then
+ pragma Assert
+ (Nkind (Subtype_Indication (Type_Definition (Decl)))
+ = N_Identifier);
+ Set_Entity (Subtype_Indication (Type_Definition (Decl)),
+ Underlying_Record_View (Full_P));
+ end if;
+
+ Install_Private_Declarations (Par_Scope);
+ Install_Visible_Declarations (Par_Scope);
+ Insert_Before (N, Decl);
+
+ -- Mark entity as an underlying record view before analysis,
+ -- to avoid generating the list of its primitive operations
+ -- (which is not really required for this entity) and thus
+ -- prevent spurious errors associated with missing overriding
+ -- of abstract primitives (overridden only for Derived_Type).
+
+ Set_Ekind (Full_Der, E_Record_Type);
+ Set_Is_Underlying_Record_View (Full_Der);
+
+ Analyze (Decl);
+
+ pragma Assert (Has_Discriminants (Full_Der)
+ and then not Has_Unknown_Discriminants (Full_Der));
+
+ Uninstall_Declarations (Par_Scope);
+
+ -- Freeze the underlying record view, to prevent generation of
+ -- useless dispatching information, which is simply shared with
+ -- the real derived type.
+
+ Set_Is_Frozen (Full_Der);
+
+ -- Set up links between real entity and underlying record view
+
+ Set_Underlying_Record_View (Derived_Type, Base_Type (Full_Der));
+ Set_Underlying_Record_View (Base_Type (Full_Der), Derived_Type);
+ end;
+
+ -- If discriminants are known, build derived record
+
+ else
+ Build_Derived_Record_Type
+ (N, Parent_Type, Derived_Type, Derive_Subps);
+ end if;
+
+ return;
+
+ elsif Has_Discriminants (Parent_Type) then
+ if Present (Full_View (Parent_Type)) then
+ if not Is_Completion then
+
+ -- Copy declaration for subsequent analysis, to provide a
+ -- completion for what is a private declaration. Indicate that
+ -- the full type is internally generated.
+
+ Full_Decl := New_Copy_Tree (N);
+ Full_Der := New_Copy (Derived_Type);
+ Set_Comes_From_Source (Full_Decl, False);
+ Set_Comes_From_Source (Full_Der, False);
+ Set_Parent (Full_Der, Full_Decl);
+
+ Insert_After (N, Full_Decl);
+
+ else
+ -- If this is a completion, the full view being built is itself
+ -- private. We build a subtype of the parent with the same
+ -- constraints as this full view, to convey to the back end the
+ -- constrained components and the size of this subtype. If the
+ -- parent is constrained, its full view can serve as the
+ -- underlying full view of the derived type.
+
+ if No (Discriminant_Specifications (N)) then
+ if Nkind (Subtype_Indication (Type_Definition (N))) =
+ N_Subtype_Indication
+ then
+ Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
+
+ elsif Is_Constrained (Full_View (Parent_Type)) then
+ Set_Underlying_Full_View
+ (Derived_Type, Full_View (Parent_Type));
+ end if;
+
+ else
+ -- If there are new discriminants, the parent subtype is
+ -- constrained by them, but it is not clear how to build
+ -- the Underlying_Full_View in this case???
+
+ null;
+ end if;
+ end if;
+ end if;
+
+ -- Build partial view of derived type from partial view of parent
+
+ Build_Derived_Record_Type
+ (N, Parent_Type, Derived_Type, Derive_Subps);
+
+ if Present (Full_View (Parent_Type)) and then not Is_Completion then
+ if not In_Open_Scopes (Par_Scope)
+ or else not In_Same_Source_Unit (N, Parent_Type)
+ then
+ -- Swap partial and full views temporarily
+
+ Install_Private_Declarations (Par_Scope);
+ Install_Visible_Declarations (Par_Scope);
+ Swapped := True;
+ end if;
+
+ -- Build full view of derived type from full view of parent which
+ -- is now installed. Subprograms have been derived on the partial
+ -- view, the completion does not derive them anew.
+
+ if not Is_Tagged_Type (Parent_Type) then
+
+ -- If the parent is itself derived from another private type,
+ -- installing the private declarations has not affected its
+ -- privacy status, so use its own full view explicitly.
+
+ if Is_Private_Type (Parent_Type) then
+ Build_Derived_Record_Type
+ (Full_Decl, Full_View (Parent_Type), Full_Der, False);
+ else
+ Build_Derived_Record_Type
+ (Full_Decl, Parent_Type, Full_Der, False);
+ end if;
+
+ else
+ -- If full view of parent is tagged, the completion inherits
+ -- the proper primitive operations.
+
+ Set_Defining_Identifier (Full_Decl, Full_Der);
+ Build_Derived_Record_Type
+ (Full_Decl, Parent_Type, Full_Der, Derive_Subps);
+ end if;
+
+ -- The full declaration has been introduced into the tree and
+ -- processed in the step above. It should not be analyzed again
+ -- (when encountered later in the current list of declarations)
+ -- to prevent spurious name conflicts. The full entity remains
+ -- invisible.
+
+ Set_Analyzed (Full_Decl);
+
+ 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 => 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);
+
+ -- Except in the context of the full view of the parent, there
+ -- are no non-extension aggregates for the derived type.
+
+ Set_Has_Private_Ancestor (Derived_Type);
+ 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 (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));
+
+ -- Check for 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.
+
+ 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
+
+ -- Note that if the parent has a completion in the private part,
+ -- (which is itself a derivation from some other private type)
+ -- it is that completion that is visible, there is no full view
+ -- available, and no special processing is needed.
+
+ and then Present (Full_View (Parent_Type))
+ then
+ -- 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 an
+ -- underlying full view that will be installed when the enclosing
+ -- child body is compiled.
+
+ Full_Der :=
+ Make_Defining_Identifier
+ (Sloc (Derived_Type), Chars (Derived_Type));
+ Set_Is_Itype (Full_Der);
+ Build_Itype_Reference (Full_Der, N);
+
+ -- 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 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 for 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, i.e. 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 (i.e. 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
+ Discriminant_Specs : constant Boolean :=
+ Present (Discriminant_Specifications (N));
+ Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
+ Loc : constant Source_Ptr := Sloc (N);
+ Private_Extension : constant Boolean :=
+ Nkind (N) = N_Private_Extension_Declaration;
+ Assoc_List : Elist_Id;
+ Constraint_Present : Boolean;
+ Constrs : Elist_Id;
+ Discrim : Entity_Id;
+ Indic : Node_Id;
+ Inherit_Discrims : Boolean := False;
+ Last_Discrim : Entity_Id;
+ New_Base : Entity_Id;
+ New_Decl : Node_Id;
+ New_Discrs : Elist_Id;
+ New_Indic : Node_Id;
+ Parent_Base : Entity_Id;
+ Save_Etype : Entity_Id;
+ Save_Discr_Constr : Elist_Id;
+ Save_Next_Entity : Entity_Id;
+ Type_Def : Node_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.
+
+ 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;
+
+ -- AI05-0115 : if this is a derivation from a private type in some
+ -- other scope that may lead to invisible components for the derived
+ -- type, mark it accordingly.
+
+ if Is_Private_Type (Parent_Type) then
+ if Scope (Parent_Type) = Scope (Derived_Type) then
+ null;
+
+ elsif In_Open_Scopes (Scope (Parent_Type))
+ and then In_Private_Part (Scope (Parent_Type))
+ then
+ null;
+
+ else
+ Set_Has_Private_Ancestor (Derived_Type);
+ end if;
+
+ else
+ Set_Has_Private_Ancestor
+ (Derived_Type, Has_Private_Ancestor (Parent_Type));
+ end if;
+
+ -- Before we start the previously documented transformations, here is
+ -- 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)
+
+ -- The type is also marked as being tagged here, which is needed when
+ -- processing components with a self-referential anonymous access type
+ -- in the call to Check_Anonymous_Access_Components below. Note that
+ -- this flag is also set later on for completeness.
+
+ if Is_Tagged then
+ Set_Is_Tagged_Type (Derived_Type);
+ 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) is 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);
+
+ -- Create internal access types for components with anonymous
+ -- access types.
+
+ if Ada_Version >= Ada_2005 then
+ Check_Anonymous_Access_Components
+ (N, Derived_Type, Derived_Type,
+ Component_List (Record_Extension_Part (Type_Def)));
+ end if;
+
+ 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 statically match
+ -- those given in the 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 Fully_Conformant_Expressions (Node (C1), Node (C2))
+ or else
+ (Is_OK_Static_Expression (Node (C1))
+ and then
+ Is_OK_Static_Expression (Node (C2))
+ and then
+ Expr_Value (Node (C1)) = Expr_Value (Node (C2)))
+ then
+ null;
+
+ else
+ 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),
+ Limited_Present => Limited_Present (Type_Def),
+ Subtype_Indication =>
+ New_Occurrence_Of (Parent_Base, Loc),
+ Record_Extension_Part =>
+ Relocate_Node (Record_Extension_Part (Type_Def)),
+ Interface_List => Interface_List (Type_Def)));
+
+ Set_Parent (New_Decl, Parent (N));
+ Mark_Rewrite_Insertion (New_Decl);
+ Insert_Before (N, New_Decl);
+
+ -- In the extension case, make sure ancestor is frozen appropriately
+ -- (see also non-discriminated case below).
+
+ if Present (Record_Extension_Part (Type_Def))
+ or else Is_Interface (Parent_Base)
+ then
+ Freeze_Before (New_Decl, Parent_Type);
+ end if;
+
+ -- 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.
+ -- Subprograms are not derived, however, when Derive_Subps is False
+ -- (since otherwise there could be redundant derivations).
+
+ if Derive_Subps then
+ Derive_Subprograms (Parent_Type, Derived_Type);
+ end if;
+
+ -- 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))
+ -- The declaration of a specific descendant of an interface type
+ -- freezes the interface type (RM 13.14).
+
+ if not Private_Extension or else Is_Interface (Parent_Base) then
+ Freeze_Before (N, Parent_Type);
+ end if;
+
+ -- In Ada 2005 (AI-344), the restriction that a derived tagged type
+ -- cannot be declared at a deeper level than its parent type is
+ -- removed. The check on derivation within a generic body is also
+ -- relaxed, but there's a restriction that a derived tagged type
+ -- cannot be declared in a generic body if it's derived directly
+ -- or indirectly from a formal type of that generic.
+
+ if Ada_Version >= Ada_2005 then
+ if Present (Enclosing_Generic_Body (Derived_Type)) then
+ declare
+ Ancestor_Type : Entity_Id;
+
+ begin
+ -- Check to see if any ancestor of the derived type is a
+ -- formal type.
+
+ Ancestor_Type := Parent_Type;
+ while not Is_Generic_Type (Ancestor_Type)
+ and then Etype (Ancestor_Type) /= Ancestor_Type
+ loop
+ Ancestor_Type := Etype (Ancestor_Type);
+ end loop;
+
+ -- If the derived type does have a formal type as an
+ -- ancestor, then it's an error if the derived type is
+ -- declared within the body of the generic unit that
+ -- declares the formal type in its generic formal part. It's
+ -- sufficient to check whether the ancestor type is declared
+ -- inside the same generic body as the derived type (such as
+ -- within a nested generic spec), in which case the
+ -- derivation is legal. If the formal type is declared
+ -- outside of that generic body, then it's guaranteed that
+ -- the derived type is declared within the generic body of
+ -- the generic unit declaring the formal type.
+
+ if Is_Generic_Type (Ancestor_Type)
+ and then Enclosing_Generic_Body (Ancestor_Type) /=
+ Enclosing_Generic_Body (Derived_Type)
+ then
+ Error_Msg_NE
+ ("parent type of& must not be descendant of formal type"
+ & " of an enclosing generic body",
+ Indic, Derived_Type);
+ end if;
+ end;
+ end if;
+
+ elsif Type_Access_Level (Derived_Type) /=
+ Type_Access_Level (Parent_Type)
+ and then not Is_Generic_Type (Derived_Type)
+ then
+ if Is_Controlled (Parent_Type) then
+ Error_Msg_N
+ ("controlled type must be declared at the library level",
+ Indic);
+ else
+ Error_Msg_N
+ ("type extension at deeper accessibility level than parent",
+ Indic);
+ end if;
+
+ else
+ declare
+ GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
+
+ begin
+ if Present (GB)
+ and then GB /= Enclosing_Generic_Body (Parent_Base)
+ then
+ Error_Msg_NE
+ ("parent type of& must not be outside generic body"
+ & " (RM 3.9.1(4))",
+ Indic, Derived_Type);
+ end if;
+ end;
+ end if;
+ end if;
+
+ -- Ada 2005 (AI-251)
+
+ if Ada_Version >= Ada_2005 and then Is_Tagged then
+
+ -- "The declaration of a specific descendant of an interface type
+ -- freezes the interface type" (RM 13.14).
+
+ declare
+ Iface : Node_Id;
+ begin
+ if Is_Non_Empty_List (Interface_List (Type_Def)) then
+ Iface := First (Interface_List (Type_Def));
+ while Present (Iface) loop
+ Freeze_Before (N, Etype (Iface));
+ Next (Iface);
+ end loop;
+ end if;
+ end;
+ end if;
+
+ -- STEP 1b : preliminary cleanup of the full view of private types
+
+ -- If the type is already marked as having discriminants, then it's the
+ -- completion of a private type or private extension and we need to
+ -- retain the discriminants from the partial view if the current
+ -- declaration has Discriminant_Specifications so that we can verify
+ -- conformance. However, we must remove any existing components that
+ -- were inherited from the parent (and attached in Copy_And_Swap)
+ -- because the full type inherits all appropriate components anyway, and
+ -- we do not want the partial view's components interfering.
+
+ if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
+ Discrim := First_Discriminant (Derived_Type);
+ loop
+ Last_Discrim := Discrim;
+ Next_Discriminant (Discrim);
+ exit when No (Discrim);
+ end loop;
+
+ Set_Last_Entity (Derived_Type, Last_Discrim);
+
+ -- In all other cases wipe out the list of inherited components (even
+ -- inherited discriminants), it will be properly rebuilt here.
+
+ else
+ Set_First_Entity (Derived_Type, Empty);
+ Set_Last_Entity (Derived_Type, Empty);
+ end if;
+
+ -- STEP 1c: Initialize some flags for the Derived_Type
+
+ -- The following flags must be initialized here so that
+ -- Process_Discriminants can check that discriminants of tagged types do
+ -- not have a default initial value and that access discriminants are
+ -- only specified for limited records. For completeness, these flags are
+ -- also initialized along with all the other flags below.
+
+ -- AI-419: Limitedness is not inherited from an interface parent, so to
+ -- be limited in that case the type must be explicitly declared as
+ -- limited. However, task and protected interfaces are always limited.
+
+ if Limited_Present (Type_Def) then
+ Set_Is_Limited_Record (Derived_Type);
+
+ elsif Is_Limited_Record (Parent_Type)
+ or else (Present (Full_View (Parent_Type))
+ and then Is_Limited_Record (Full_View (Parent_Type)))
+ then
+ if not Is_Interface (Parent_Type)
+ or else Is_Synchronized_Interface (Parent_Type)
+ or else Is_Protected_Interface (Parent_Type)
+ or else Is_Task_Interface (Parent_Type)
+ then
+ Set_Is_Limited_Record (Derived_Type);
+ end if;
+ end if;
+
+ -- STEP 2a: process discriminants of derived type if any
+
+ Push_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 untagged types, the constraint on the Parent_Type must be
+ -- present and is used to rename the discriminants.
+
+ if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
+ Error_Msg_N ("untagged parent must have discriminants", Indic);
+
+ elsif not Is_Tagged and then not Constraint_Present then
+ Error_Msg_N
+ ("discriminant constraint needed for derived untagged records",
+ Indic);
+
+ -- Otherwise the parent subtype must be constrained unless we have a
+ -- private extension.
+
+ elsif not Constraint_Present
+ and then not Private_Extension
+ and then not Is_Constrained (Parent_Type)
+ then
+ Error_Msg_N
+ ("unconstrained type not allowed in this context", Indic);
+
+ elsif Constraint_Present then
+ -- The following call sets the field Corresponding_Discriminant
+ -- for the discriminants in the Derived_Type.
+
+ Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
+
+ -- For untagged types all new discriminants must rename
+ -- discriminants in the parent. For private extensions new
+ -- discriminants cannot rename old ones (implied by [7.3(13)]).
+
+ Discrim := First_Discriminant (Derived_Type);
+ while Present (Discrim) loop
+ if not Is_Tagged
+ and then No (Corresponding_Discriminant (Discrim))
+ then
+ Error_Msg_N
+ ("new discriminants must constrain old ones", Discrim);
+
+ elsif Private_Extension
+ and then Present (Corresponding_Discriminant (Discrim))
+ then
+ Error_Msg_N
+ ("only static constraints allowed for parent"
+ & " discriminants in the partial view", Indic);
+ exit;
+ end if;
+
+ -- If a new discriminant is used in the constraint, then its
+ -- subtype must be statically compatible with the parent
+ -- discriminant's subtype (3.7(15)).
+
+ -- However, if the record contains an array constrained by
+ -- the discriminant but with some different bound, the compiler
+ -- attemps to create a smaller range for the discriminant type.
+ -- (See exp_ch3.Adjust_Discriminants). In this case, where
+ -- the discriminant type is a scalar type, the check must use
+ -- the original discriminant type in the parent declaration.
+
+ declare
+ Corr_Disc : constant Entity_Id :=
+ Corresponding_Discriminant (Discrim);
+ Disc_Type : constant Entity_Id := Etype (Discrim);
+ Corr_Type : Entity_Id;
+
+ begin
+ if Present (Corr_Disc) then
+ if Is_Scalar_Type (Disc_Type) then
+ Corr_Type :=
+ Entity (Discriminant_Type (Parent (Corr_Disc)));
+ else
+ Corr_Type := Etype (Corr_Disc);
+ end if;
+
+ if not
+ Subtypes_Statically_Compatible (Disc_Type, Corr_Type)
+ then
+ Error_Msg_N
+ ("subtype must be compatible "
+ & "with parent discriminant",
+ Discrim);
+ end if;
+ end if;
+ end;
+
+ Next_Discriminant (Discrim);
+ end loop;
+
+ -- Check whether the constraints of the full view statically
+ -- match those imposed by the parent subtype [7.3(13)].
+
+ if Present (Stored_Constraint (Derived_Type)) then
+ declare
+ C1, C2 : Elmt_Id;
+
+ begin
+ C1 := First_Elmt (Discs);
+ C2 := First_Elmt (Stored_Constraint (Derived_Type));
+ while Present (C1) and then Present (C2) loop
+ if not
+ Fully_Conformant_Expressions (Node (C1), Node (C2))
+ then
+ Error_Msg_N
+ ("not conformant with previous declaration",
+ Node (C1));
+ end if;
+
+ Next_Elmt (C1);
+ Next_Elmt (C2);
+ end loop;
+ end;
+ end if;
+ end if;
+
+ -- STEP 2b: No new discriminants, inherit discriminants if any
+
+ else
+ if Private_Extension then
+ Set_Has_Unknown_Discriminants
+ (Derived_Type,
+ Has_Unknown_Discriminants (Parent_Type)
+ or else Unknown_Discriminants_Present (N));
+
+ -- The partial view of the parent may have unknown discriminants,
+ -- but if the full view has discriminants and the parent type is
+ -- in scope they must be inherited.
+
+ elsif Has_Unknown_Discriminants (Parent_Type)
+ and then
+ (not Has_Discriminants (Parent_Type)
+ or else not In_Open_Scopes (Scope (Parent_Type)))
+ then
+ Set_Has_Unknown_Discriminants (Derived_Type);
+ end if;
+
+ if not Has_Unknown_Discriminants (Derived_Type)
+ and then not Has_Unknown_Discriminants (Parent_Base)
+ and then Has_Discriminants (Parent_Type)
+ then
+ Inherit_Discrims := True;
+ Set_Has_Discriminants
+ (Derived_Type, True);
+ Set_Discriminant_Constraint
+ (Derived_Type, Discriminant_Constraint (Parent_Base));
+ end if;
+
+ -- The following test is true for private types (remember
+ -- transformation 5. is not applied to those) and in an error
+ -- situation.
+
+ if Constraint_Present then
+ Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
+ end if;
+
+ -- For now mark a new derived type as constrained only if it has no
+ -- discriminants. At the end of Build_Derived_Record_Type we properly
+ -- set this flag in the case of private extensions. See comments in
+ -- point 9. just before body of Build_Derived_Record_Type.
+
+ Set_Is_Constrained
+ (Derived_Type,
+ not (Inherit_Discrims
+ or else Has_Unknown_Discriminants (Derived_Type)));
+ end if;
+
+ -- STEP 3: initialize fields of derived type
+
+ Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
+ Set_Stored_Constraint (Derived_Type, No_Elist);
+
+ -- Ada 2005 (AI-251): Private type-declarations can implement interfaces
+ -- but cannot be interfaces
+
+ if not Private_Extension
+ and then Ekind (Derived_Type) /= E_Private_Type
+ and then Ekind (Derived_Type) /= E_Limited_Private_Type
+ then
+ if Interface_Present (Type_Def) then
+ Analyze_Interface_Declaration (Derived_Type, Type_Def);
+ end if;
+
+ Set_Interfaces (Derived_Type, No_Elist);
+ end if;
+
+ -- Fields inherited from the 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_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));
+
+ -- Fields inherited from the Parent_Base in the non-private case
+
+ if Ekind (Derived_Type) = E_Record_Type then
+ Set_Has_Complex_Representation
+ (Derived_Type, Has_Complex_Representation (Parent_Base));
+ end if;
+
+ -- Fields inherited from the Parent_Base for record types
+
+ if Is_Record_Type (Derived_Type) then
+
+ declare
+ Parent_Full : Entity_Id;
+
+ begin
+ -- Ekind (Parent_Base) is not necessarily E_Record_Type since
+ -- Parent_Base can be a private type or private extension. Go
+ -- to the full view here to get the E_Record_Type specific flags.
+
+ if Present (Full_View (Parent_Base)) then
+ Parent_Full := Full_View (Parent_Base);
+ else
+ Parent_Full := Parent_Base;
+ end if;
+
+ Set_OK_To_Reorder_Components
+ (Derived_Type, OK_To_Reorder_Components (Parent_Full));
+ end;
+ 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_Direct_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;
+
+ -- Minor optimization: there is no need to generate the class-wide
+ -- entity associated with an underlying record view.
+
+ if not Is_Underlying_Record_View (Derived_Type) then
+ Make_Class_Wide_Type (Derived_Type);
+ end if;
+
+ Set_Is_Abstract_Type (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;
+
+ if Ada_Version >= Ada_2005 then
+ declare
+ Ifaces_List : Elist_Id;
+
+ begin
+ -- Checks rules 3.9.4 (13/2 and 14/2)
+
+ if Comes_From_Source (Derived_Type)
+ and then not Is_Private_Type (Derived_Type)
+ and then Is_Interface (Parent_Type)
+ and then not Is_Interface (Derived_Type)
+ then
+ if Is_Task_Interface (Parent_Type) then
+ Error_Msg_N
+ ("(Ada 2005) task type required (RM 3.9.4 (13.2))",
+ Derived_Type);
+
+ elsif Is_Protected_Interface (Parent_Type) then
+ Error_Msg_N
+ ("(Ada 2005) protected type required (RM 3.9.4 (14.2))",
+ Derived_Type);
+ end if;
+ end if;
+
+ -- Check ARM rules 3.9.4 (15/2), 9.1 (9.d/2) and 9.4 (11.d/2)
+
+ Check_Interfaces (N, Type_Def);
+
+ -- Ada 2005 (AI-251): Collect the list of progenitors that are
+ -- not already in the parents.
+
+ Collect_Interfaces
+ (T => Derived_Type,
+ Ifaces_List => Ifaces_List,
+ Exclude_Parents => True);
+
+ Set_Interfaces (Derived_Type, Ifaces_List);
+
+ -- If the derived type is the anonymous type created for
+ -- a declaration whose parent has a constraint, propagate
+ -- the interface list to the source type. This must be done
+ -- prior to the completion of the analysis of the source type
+ -- because the components in the extension may contain current
+ -- instances whose legality depends on some ancestor.
+
+ if Is_Itype (Derived_Type) then
+ declare
+ Def : constant Node_Id :=
+ Associated_Node_For_Itype (Derived_Type);
+ begin
+ if Present (Def)
+ and then Nkind (Def) = N_Full_Type_Declaration
+ then
+ Set_Interfaces
+ (Defining_Identifier (Def), Ifaces_List);
+ end if;
+ end;
+ end if;
+ end;
+ 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);
+ Set_Has_Implicit_Dereference
+ (Derived_Type, Has_Implicit_Dereference (Parent_Type));
+ end if;
+
+ -- Insert the new derived type declaration
+
+ Rewrite (N, New_Decl);
+
+ -- STEP 5b: Complete the processing for record extensions in generics
+
+ -- There is no completion for record extensions declared in the
+ -- parameter part of a generic, so we need to complete processing for
+ -- these generic record extensions here. The Record_Type_Definition call
+ -- will change the Ekind of the components from E_Void to E_Component.
+
+ elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
+ Record_Type_Definition (Empty, Derived_Type);
+
+ -- STEP 5c: Process the record extension for non private tagged types
+
+ elsif not Private_Extension then
+
+ -- Add the _parent field in the derived type
+
+ Expand_Record_Extension (Derived_Type, Type_Def);
+
+ -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
+ -- implemented interfaces if we are in expansion mode
+
+ if Expander_Active
+ and then Has_Interfaces (Derived_Type)
+ then
+ Add_Interface_Tag_Components (N, Derived_Type);
+ end if;
+
+ -- Analyze the record extension
+
+ Record_Type_Definition
+ (Record_Extension_Part (Type_Def), Derived_Type);
+ end if;
+
+ End_Scope;
+
+ -- Nothing else to do if there is an error in the derivation.
+ -- An unusual case: the full view may be derived from a type in an
+ -- instance, when the partial view was used illegally as an actual
+ -- in that instance, leading to a circular definition.
+
+ if Etype (Derived_Type) = Any_Type
+ or else Etype (Parent_Type) = Derived_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. In case of underlying record views,
+ -- we do not generate the corresponding class wide entity.
+
+ if Is_Tagged
+ and then not Is_Underlying_Record_View (Derived_Type)
+ 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;
+
+ Check_Function_Writable_Actuals (N);
+ 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_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
+ Set_Is_Tagged_Type (Derived_Type, Is_Tagged_Type (Parent_Type));
+
+ -- If the parent type is a private subtype, the convention on the base
+ -- type may be set in the private part, and not propagated to the
+ -- subtype until later, so we obtain the convention from the base type.
+
+ Set_Convention (Derived_Type, Convention (Parent_Base));
+
+ -- Propagate invariant information. The new type has invariants if
+ -- they are inherited from the parent type, and these invariants can
+ -- be further inherited, so both flags are set.
+
+ -- We similarly inherit predicates
+
+ if Has_Predicates (Parent_Type) then
+ Set_Has_Predicates (Derived_Type);
+ end if;
+
+ -- 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;
+ -- Used to iterate over representation items of the derived type
+
+ Last_Rep : Node_Id;
+ -- Last representation item of the (non-empty) representation
+ -- item list of the derived type.
+
+ Found : Boolean := False;
+
+ begin
+ Rep := First_Rep_Item (Derived_Type);
+ Last_Rep := Rep;
+ while Present (Rep) loop
+ if Rep = First_Rep_Item (Parent_Type) then
+ Found := True;
+ exit;
+
+ else
+ Rep := Next_Rep_Item (Rep);
+
+ if Present (Rep) then
+ Last_Rep := Rep;
+ end if;
+ end if;
+ end loop;
+
+ -- Here if we either encountered the parent type's first rep
+ -- item on the derived type's rep item list (in which case
+ -- Found is True, and we have nothing else to do), or if we
+ -- reached the last rep item of the derived type, which is
+ -- Last_Rep, in which case we further chain the parent type's
+ -- rep items to those of the derived type.
+
+ if not Found then
+ Set_Next_Rep_Item (Last_Rep, 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 (Discrim));
+
+ Set_Ekind (D_Minal, E_In_Parameter);
+ Set_Mechanism (D_Minal, Default_Mechanism);
+ Set_Etype (D_Minal, Etype (Discrim));
+ Set_Scope (D_Minal, Current_Scope);
+
+ 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_Scope (CR_Disc, Current_Scope);
+ Set_Discriminal_Link (CR_Disc, Discrim);
+ Set_CR_Discriminant (Discrim, CR_Disc);
+ end if;
+ end Build_Discriminal;
+
+ ------------------------------------
+ -- Build_Discriminant_Constraints --
+ ------------------------------------
+
+ function Build_Discriminant_Constraints
+ (T : Entity_Id;
+ Def : Node_Id;
+ Derived_Def : Boolean := False) return Elist_Id
+ is
+ C : constant Node_Id := Constraint (Def);
+ Nb_Discr : constant Nat := Number_Discriminants (T);
+
+ Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
+ -- Saves the expression corresponding to a given discriminant in T
+
+ function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
+ -- Return the Position number within array Discr_Expr of a discriminant
+ -- D within the discriminant list of the discriminated type T.
+
+ procedure Process_Discriminant_Expression
+ (Expr : Node_Id;
+ D : Entity_Id);
+ -- If this is a discriminant constraint on a partial view, do not
+ -- generate an overflow check on the discriminant expression. The check
+ -- will be generated when constraining the full view. Otherwise the
+ -- backend creates duplicate symbols for the temporaries corresponding
+ -- to the expressions to be checked, causing spurious assembler errors.
+
+ ------------------
+ -- 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;
+
+ -------------------------------------
+ -- Process_Discriminant_Expression --
+ -------------------------------------
+
+ procedure Process_Discriminant_Expression
+ (Expr : Node_Id;
+ D : Entity_Id)
+ is
+ BDT : constant Entity_Id := Base_Type (Etype (D));
+
+ begin
+ -- If this is a discriminant constraint on a partial view, do
+ -- not generate an overflow on the discriminant expression. The
+ -- check will be generated when constraining the full view.
+
+ if Is_Private_Type (T)
+ and then Present (Full_View (T))
+ then
+ Analyze_And_Resolve (Expr, BDT, Suppress => Overflow_Check);
+
+ else
+ Analyze_And_Resolve (Expr, BDT);
+ end if;
+ end Process_Discriminant_Expression;
+
+ -- 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
+ Process_Discriminant_Expression (Constr, 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, i.e. X.
+
+ if Present (Original_Discriminant (Id))
+ and then In_Instance
+ 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;
+
+ -- If the parent type is a generic formal, preserve the
+ -- name of the discriminant for subsequent instances.
+ -- see comment at the beginning of this if statement.
+
+ elsif Is_Generic_Type (Root_Type (T)) then
+ 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;
+ Process_Discriminant_Expression (Expr, 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_Concurrent => 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));
+
+ elsif Is_Access_Type (Etype (Discr))
+ and then not Is_Access_Constant (Etype (Discr))
+ and then Is_Access_Type (Etype (Discr_Expr (J)))
+ and then Is_Access_Constant (Etype (Discr_Expr (J)))
+ then
+ Error_Msg_NE
+ ("constraint for discriminant& must be access to variable",
+ Def, 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;
+
+ -- Inherit preelaboration flag from base, for types for which it
+ -- may have been set: records, private types, protected types.
+
+ Set_Known_To_Have_Preelab_Init
+ (Def_Id, Known_To_Have_Preelab_Init (T));
+
+ 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);
+ Set_Known_To_Have_Preelab_Init
+ (Def_Id, Known_To_Have_Preelab_Init (T));
+
+ elsif Is_Private_Type (T) then
+ Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
+ Set_Known_To_Have_Preelab_Init
+ (Def_Id, Known_To_Have_Preelab_Init (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_Has_Implicit_Dereference
+ (Def_Id, Has_Implicit_Dereference (T));
+
+ -- If the subtype is the completion of a private declaration, there may
+ -- have been representation clauses for the partial view, and they must
+ -- be preserved. Build_Derived_Type chains the inherited clauses with
+ -- the ones appearing on the extension. If this comes from a subtype
+ -- declaration, all clauses are inherited.
+
+ if No (First_Rep_Item (Def_Id)) then
+ Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
+ end if;
+
+ if Is_Tagged_Type (T) then
+ Set_Is_Tagged_Type (Def_Id);
+ Make_Class_Wide_Type (Def_Id);
+ end if;
+
+ Set_Stored_Constraint (Def_Id, No_Elist);
+
+ if Has_Discrs then
+ Set_Discriminant_Constraint (Def_Id, Elist);
+ Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
+ end if;
+
+ if Is_Tagged_Type (T) then
+
+ -- Ada 2005 (AI-251): In case of concurrent types we inherit the
+ -- concurrent record type (which has the list of primitive
+ -- operations).
+
+ if Ada_Version >= Ada_2005
+ and then Is_Concurrent_Type (T)
+ then
+ Set_Corresponding_Record_Type (Def_Id,
+ Corresponding_Record_Type (T));
+ else
+ Set_Direct_Primitive_Operations (Def_Id,
+ Direct_Primitive_Operations (T));
+ end if;
+
+ Set_Is_Abstract_Type (Def_Id, Is_Abstract_Type (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_Itype_Reference --
+ ---------------------------
+
+ procedure Build_Itype_Reference
+ (Ityp : Entity_Id;
+ Nod : Node_Id)
+ is
+ IR : constant Node_Id := Make_Itype_Reference (Sloc (Nod));
+ begin
+
+ -- Itype references are only created for use by the back-end
+
+ if Inside_A_Generic then
+ return;
+ else
+ Set_Itype (IR, Ityp);
+ Insert_After (Nod, IR);
+ end if;
+ end Build_Itype_Reference;
+
+ ------------------------
+ -- 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_In (Bound, N_Integer_Literal, 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
+ Alias_Subp : Entity_Id;
+ Elmt : Elmt_Id;
+ Op_List : Elist_Id;
+ Subp : Entity_Id;
+ Type_Def : Node_Id;
+
+ procedure Check_Pragma_Implemented (Subp : Entity_Id);
+ -- Ada 2012 (AI05-0030): Subprogram Subp overrides an interface routine
+ -- which has pragma Implemented already set. Check whether Subp's entity
+ -- kind conforms to the implementation kind of the overridden routine.
+
+ procedure Check_Pragma_Implemented
+ (Subp : Entity_Id;
+ Iface_Subp : Entity_Id);
+ -- Ada 2012 (AI05-0030): Subprogram Subp overrides interface routine
+ -- Iface_Subp and both entities have pragma Implemented already set on
+ -- them. Check whether the two implementation kinds are conforming.
+
+ procedure Inherit_Pragma_Implemented
+ (Subp : Entity_Id;
+ Iface_Subp : Entity_Id);
+ -- Ada 2012 (AI05-0030): Interface primitive Subp overrides interface
+ -- subprogram Iface_Subp which has been marked by pragma Implemented.
+ -- Propagate the implementation kind of Iface_Subp to Subp.
+
+ ------------------------------
+ -- Check_Pragma_Implemented --
+ ------------------------------
+
+ procedure Check_Pragma_Implemented (Subp : Entity_Id) is
+ Iface_Alias : constant Entity_Id := Interface_Alias (Subp);
+ Impl_Kind : constant Name_Id := Implementation_Kind (Iface_Alias);
+ Subp_Alias : constant Entity_Id := Alias (Subp);
+ Contr_Typ : Entity_Id;
+ Impl_Subp : Entity_Id;
+
+ begin
+ -- Subp must have an alias since it is a hidden entity used to link
+ -- an interface subprogram to its overriding counterpart.
+
+ pragma Assert (Present (Subp_Alias));
+
+ -- Handle aliases to synchronized wrappers
+
+ Impl_Subp := Subp_Alias;
+
+ if Is_Primitive_Wrapper (Impl_Subp) then
+ Impl_Subp := Wrapped_Entity (Impl_Subp);
+ end if;
+
+ -- Extract the type of the controlling formal
+
+ Contr_Typ := Etype (First_Formal (Subp_Alias));
+
+ if Is_Concurrent_Record_Type (Contr_Typ) then
+ Contr_Typ := Corresponding_Concurrent_Type (Contr_Typ);
+ end if;
+
+ -- An interface subprogram whose implementation kind is By_Entry must
+ -- be implemented by an entry.
+
+ if Impl_Kind = Name_By_Entry
+ and then Ekind (Impl_Subp) /= E_Entry
+ then
+ Error_Msg_Node_2 := Iface_Alias;
+ Error_Msg_NE
+ ("type & must implement abstract subprogram & with an entry",
+ Subp_Alias, Contr_Typ);
+
+ elsif Impl_Kind = Name_By_Protected_Procedure then
+
+ -- An interface subprogram whose implementation kind is By_
+ -- Protected_Procedure cannot be implemented by a primitive
+ -- procedure of a task type.
+
+ if Ekind (Contr_Typ) /= E_Protected_Type then
+ Error_Msg_Node_2 := Contr_Typ;
+ Error_Msg_NE
+ ("interface subprogram & cannot be implemented by a " &
+ "primitive procedure of task type &", Subp_Alias,
+ Iface_Alias);
+
+ -- An interface subprogram whose implementation kind is By_
+ -- Protected_Procedure must be implemented by a procedure.
+
+ elsif Ekind (Impl_Subp) /= E_Procedure then
+ Error_Msg_Node_2 := Iface_Alias;
+ Error_Msg_NE
+ ("type & must implement abstract subprogram & with a " &
+ "procedure", Subp_Alias, Contr_Typ);
+ end if;
+ end if;
+ end Check_Pragma_Implemented;
+
+ ------------------------------
+ -- Check_Pragma_Implemented --
+ ------------------------------
+
+ procedure Check_Pragma_Implemented
+ (Subp : Entity_Id;
+ Iface_Subp : Entity_Id)
+ is
+ Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
+ Subp_Kind : constant Name_Id := Implementation_Kind (Subp);
+
+ begin
+ -- Ada 2012 (AI05-0030): The implementation kinds of an overridden
+ -- and overriding subprogram are different. In general this is an
+ -- error except when the implementation kind of the overridden
+ -- subprograms is By_Any or Optional.
+
+ if Iface_Kind /= Subp_Kind
+ and then Iface_Kind /= Name_By_Any
+ and then Iface_Kind /= Name_Optional
+ then
+ if Iface_Kind = Name_By_Entry then
+ Error_Msg_N
+ ("incompatible implementation kind, overridden subprogram " &
+ "is marked By_Entry", Subp);
+ else
+ Error_Msg_N
+ ("incompatible implementation kind, overridden subprogram " &
+ "is marked By_Protected_Procedure", Subp);
+ end if;
+ end if;
+ end Check_Pragma_Implemented;
+
+ --------------------------------
+ -- Inherit_Pragma_Implemented --
+ --------------------------------
+
+ procedure Inherit_Pragma_Implemented
+ (Subp : Entity_Id;
+ Iface_Subp : Entity_Id)
+ is
+ Iface_Kind : constant Name_Id := Implementation_Kind (Iface_Subp);
+ Loc : constant Source_Ptr := Sloc (Subp);
+ Impl_Prag : Node_Id;
+
+ begin
+ -- Since the implementation kind is stored as a representation item
+ -- rather than a flag, create a pragma node.
+
+ Impl_Prag :=
+ Make_Pragma (Loc,
+ Chars => Name_Implemented,
+ Pragma_Argument_Associations => New_List (
+ Make_Pragma_Argument_Association (Loc,
+ Expression => New_Reference_To (Subp, Loc)),
+
+ Make_Pragma_Argument_Association (Loc,
+ Expression => Make_Identifier (Loc, Iface_Kind))));
+
+ -- The pragma doesn't need to be analyzed because it is internally
+ -- built. It is safe to directly register it as a rep item since we
+ -- are only interested in the characters of the implementation kind.
+
+ Record_Rep_Item (Subp, Impl_Prag);
+ end Inherit_Pragma_Implemented;
+
+ -- Start of processing for Check_Abstract_Overriding
+
+ begin
+ Op_List := Primitive_Operations (T);
+
+ -- Loop to check primitive operations
+
+ Elmt := First_Elmt (Op_List);
+ while Present (Elmt) loop
+ Subp := Node (Elmt);
+ Alias_Subp := Alias (Subp);
+
+ -- Inherited subprograms are identified by the fact that they do not
+ -- come from source, and the associated source location is the
+ -- location of the first subtype of the derived type.
+
+ -- Ada 2005 (AI-228): Apply the rules of RM-3.9.3(6/2) for
+ -- subprograms that "require overriding".
+
+ -- Special exception, do not complain about failure to override the
+ -- stream routines _Input and _Output, as well as the primitive
+ -- operations used in dispatching selects since we always provide
+ -- automatic overridings for these subprograms.
+
+ -- Also ignore this rule for convention CIL since .NET libraries
+ -- do bizarre things with interfaces???
+
+ -- The partial view of T may have been a private extension, for
+ -- which inherited functions dispatching on result are abstract.
+ -- If the full view is a null extension, there is no need for
+ -- overriding in Ada 2005, but wrappers need to be built for them
+ -- (see exp_ch3, Build_Controlling_Function_Wrappers).
+
+ if Is_Null_Extension (T)
+ and then Has_Controlling_Result (Subp)
+ and then Ada_Version >= Ada_2005
+ and then Present (Alias_Subp)
+ and then not Comes_From_Source (Subp)
+ and then not Is_Abstract_Subprogram (Alias_Subp)
+ and then not Is_Access_Type (Etype (Subp))
+ then
+ null;
+
+ -- Ada 2005 (AI-251): Internal entities of interfaces need no
+ -- processing because this check is done with the aliased
+ -- entity
+
+ elsif Present (Interface_Alias (Subp)) then
+ null;
+
+ elsif (Is_Abstract_Subprogram (Subp)
+ or else Requires_Overriding (Subp)
+ or else
+ (Has_Controlling_Result (Subp)
+ and then Present (Alias_Subp)
+ and then not Comes_From_Source (Subp)
+ and then Sloc (Subp) = Sloc (First_Subtype (T))))
+ and then not Is_TSS (Subp, TSS_Stream_Input)
+ and then not Is_TSS (Subp, TSS_Stream_Output)
+ and then not Is_Abstract_Type (T)
+ and then Convention (T) /= Convention_CIL
+ and then not Is_Predefined_Interface_Primitive (Subp)
+
+ -- Ada 2005 (AI-251): Do not consider hidden entities associated
+ -- with abstract interface types because the check will be done
+ -- with the aliased entity (otherwise we generate a duplicated
+ -- error message).
+
+ and then not Present (Interface_Alias (Subp))
+ then
+ if Present (Alias_Subp) then
+
+ -- Only perform the check for a derived subprogram when the
+ -- type has an explicit record extension. This avoids incorrect
+ -- flagging of abstract subprograms for the case of a type
+ -- without an extension that is derived from a formal type
+ -- with a tagged actual (can occur within a private part).
+
+ -- Ada 2005 (AI-391): In the case of an inherited function with
+ -- a controlling result of the type, the rule does not apply if
+ -- the type is a null extension (unless the parent function
+ -- itself is abstract, in which case the function must still be
+ -- be overridden). The expander will generate an overriding
+ -- wrapper function calling the parent subprogram (see
+ -- Exp_Ch3.Make_Controlling_Wrapper_Functions).
+
+ Type_Def := Type_Definition (Parent (T));
+
+ if Nkind (Type_Def) = N_Derived_Type_Definition
+ and then Present (Record_Extension_Part (Type_Def))
+ and then
+ (Ada_Version < Ada_2005
+ or else not Is_Null_Extension (T)
+ or else Ekind (Subp) = E_Procedure
+ or else not Has_Controlling_Result (Subp)
+ or else Is_Abstract_Subprogram (Alias_Subp)
+ or else Requires_Overriding (Subp)
+ or else Is_Access_Type (Etype (Subp)))
+ then
+ -- Avoid reporting error in case of abstract predefined
+ -- primitive inherited from interface type because the
+ -- body of internally generated predefined primitives
+ -- of tagged types are generated later by Freeze_Type
+
+ if Is_Interface (Root_Type (T))
+ and then Is_Abstract_Subprogram (Subp)
+ and then Is_Predefined_Dispatching_Operation (Subp)
+ and then not Comes_From_Source (Ultimate_Alias (Subp))
+ then
+ null;
+
+ else
+ Error_Msg_NE
+ ("type must be declared abstract or & overridden",
+ T, Subp);
+
+ -- Traverse the whole chain of aliased subprograms to
+ -- complete the error notification. This is especially
+ -- useful for traceability of the chain of entities when
+ -- the subprogram corresponds with an interface
+ -- subprogram (which may be defined in another package).
+
+ if Present (Alias_Subp) then
+ declare
+ E : Entity_Id;
+
+ begin
+ E := Subp;
+ while Present (Alias (E)) loop
+
+ -- Avoid reporting redundant errors on entities
+ -- inherited from interfaces
+
+ if Sloc (E) /= Sloc (T) then
+ Error_Msg_Sloc := Sloc (E);
+ Error_Msg_NE
+ ("\& has been inherited #", T, Subp);
+ end if;
+
+ E := Alias (E);
+ end loop;
+
+ Error_Msg_Sloc := Sloc (E);
+
+ -- AI05-0068: report if there is an overriding
+ -- non-abstract subprogram that is invisible.
+
+ if Is_Hidden (E)
+ and then not Is_Abstract_Subprogram (E)
+ then
+ Error_Msg_NE
+ ("\& subprogram# is not visible",
+ T, Subp);
+
+ else
+ Error_Msg_NE
+ ("\& has been inherited from subprogram #",
+ T, Subp);
+ end if;
+ end;
+ end if;
+ end if;
+
+ -- Ada 2005 (AI-345): Protected or task type implementing
+ -- abstract interfaces.
+
+ elsif Is_Concurrent_Record_Type (T)
+ and then Present (Interfaces (T))
+ then
+ -- The controlling formal of Subp must be of mode "out",
+ -- "in out" or an access-to-variable to be overridden.
+
+ if Ekind (First_Formal (Subp)) = E_In_Parameter
+ and then Ekind (Subp) /= E_Function
+ then
+ if not Is_Predefined_Dispatching_Operation (Subp)
+ and then Is_Protected_Type
+ (Corresponding_Concurrent_Type (T))
+ then
+ Error_Msg_PT (T, Subp);
+ end if;
+
+ -- Some other kind of overriding failure
+
+ else
+ Error_Msg_NE
+ ("interface subprogram & must be overridden",
+ T, Subp);
+
+ -- Examine primitive operations of synchronized type,
+ -- to find homonyms that have the wrong profile.
+
+ declare
+ Prim : Entity_Id;
+
+ begin
+ Prim :=
+ First_Entity (Corresponding_Concurrent_Type (T));
+ while Present (Prim) loop
+ if Chars (Prim) = Chars (Subp) then
+ Error_Msg_NE
+ ("profile is not type conformant with "
+ & "prefixed view profile of "
+ & "inherited operation&", Prim, Subp);
+ end if;
+
+ Next_Entity (Prim);
+ end loop;
+ end;
+ end if;
+ end if;
+
+ else
+ Error_Msg_Node_2 := T;
+ Error_Msg_N
+ ("abstract subprogram& not allowed for type&", Subp);
+
+ -- Also post unconditional warning on the type (unconditional
+ -- so that if there are more than one of these cases, we get
+ -- them all, and not just the first one).
+
+ Error_Msg_Node_2 := Subp;
+ Error_Msg_N ("nonabstract type& has abstract subprogram&!", T);
+ end if;
+ end if;
+
+ -- Ada 2012 (AI05-0030): Perform some checks related to pragma
+ -- Implemented
+
+ -- Subp is an expander-generated procedure which maps an interface
+ -- alias to a protected wrapper. The interface alias is flagged by
+ -- pragma Implemented. Ensure that Subp is a procedure when the
+ -- implementation kind is By_Protected_Procedure or an entry when
+ -- By_Entry.
+
+ if Ada_Version >= Ada_2012
+ and then Is_Hidden (Subp)
+ and then Present (Interface_Alias (Subp))
+ and then Has_Rep_Pragma (Interface_Alias (Subp), Name_Implemented)
+ then
+ Check_Pragma_Implemented (Subp);
+ end if;
+
+ -- Subp is an interface primitive which overrides another interface
+ -- primitive marked with pragma Implemented.
+
+ if Ada_Version >= Ada_2012
+ and then Present (Overridden_Operation (Subp))
+ and then Has_Rep_Pragma
+ (Overridden_Operation (Subp), Name_Implemented)
+ then
+ -- If the overriding routine is also marked by Implemented, check
+ -- that the two implementation kinds are conforming.
+
+ if Has_Rep_Pragma (Subp, Name_Implemented) then
+ Check_Pragma_Implemented
+ (Subp => Subp,
+ Iface_Subp => Overridden_Operation (Subp));
+
+ -- Otherwise the overriding routine inherits the implementation
+ -- kind from the overridden subprogram.
+
+ else
+ Inherit_Pragma_Implemented
+ (Subp => Subp,
+ Iface_Subp => Overridden_Operation (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)).
+
+ -- AI-0063: The proper condition is that type must be immutably limited,
+ -- or else be a partial view.
+
+ if Nkind (Discriminant_Type (D)) = N_Access_Definition then
+ if Is_Immutably_Limited_Type (Current_Scope)
+ or else
+ (Nkind (Parent (Current_Scope)) = N_Private_Type_Declaration
+ and then Limited_Present (Parent (Current_Scope)))
+ then
+ null;
+
+ else
+ Error_Msg_N
+ ("access discriminants allowed only for limited types", Loc);
+ end if;
+ end if;
+ end Check_Access_Discriminant_Requires_Limited;
+
+ -----------------------------------
+ -- Check_Aliased_Component_Types --
+ -----------------------------------
+
+ procedure Check_Aliased_Component_Types (T : Entity_Id) is
+ C : Entity_Id;
+
+ begin
+ -- ??? Also need to check components of record extensions, but not
+ -- components of protected types (which are always limited).
+
+ -- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
+ -- types to be unconstrained. This is safe because it is illegal to
+ -- create access subtypes to such types with explicit discriminant
+ -- constraints.
+
+ if not Is_Limited_Type (T) then
+ if Ekind (T) = E_Record_Type then
+ C := First_Component (T);
+ while Present (C) loop
+ if Is_Aliased (C)
+ and then Has_Discriminants (Etype (C))
+ and then not Is_Constrained (Etype (C))
+ and then not In_Instance_Body
+ and then Ada_Version < Ada_2005
+ then
+ Error_Msg_N
+ ("aliased component must be constrained (RM 3.6(11))",
+ C);
+ end if;
+
+ Next_Component (C);
+ end loop;
+
+ elsif Ekind (T) = E_Array_Type then
+ if Has_Aliased_Components (T)
+ and then Has_Discriminants (Component_Type (T))
+ and then not Is_Constrained (Component_Type (T))
+ and then not In_Instance_Body
+ and then Ada_Version < Ada_2005
+ then
+ Error_Msg_N
+ ("aliased component type must be constrained (RM 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
+
+ procedure Missing_Body;
+ -- Output missing body message
+
+ ------------------
+ -- Missing_Body --
+ ------------------
+
+ procedure Missing_Body is
+ begin
+ -- Spec is in same unit, so we can post on spec
+
+ if In_Same_Source_Unit (Body_Id, E) then
+ Error_Msg_N ("missing body for &", E);
+
+ -- Spec is in a separate unit, so we have to post on the body
+
+ else
+ Error_Msg_NE ("missing body for & declared#!", Body_Id, E);
+ end if;
+ end Missing_Body;
+
+ -- Start of processing for Post_Error
+
+ begin
+ if not Comes_From_Source (E) then
+
+ if Ekind_In (E, E_Task_Type, 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 expansion,
+ -- 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
+ Missing_Body;
+ end if;
+ end;
+
+ else
+ Missing_Body;
+ end if;
+ end if;
+ end if;
+ end Post_Error;
+
+ -- Start of 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.
+
+ -- Ignore missing completion for a subprogram that does not come from
+ -- source (including the _Call primitive operation of RAS types,
+ -- which has to have the flag Comes_From_Source for other purposes):
+ -- we assume that the expander will provide the missing completion.
+ -- In case of previous errors, other expansion actions that provide
+ -- bodies for null procedures with not be invoked, so inhibit message
+ -- in those cases.
+
+ -- Note that E_Operator is not in the list that follows, because
+ -- this kind is reserved for predefined operators, that are
+ -- intrinsic and do not need completion.
+
+ 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 Has_Completion (E) then
+ null;
+
+ elsif Is_Subprogram (E) and then Is_Abstract_Subprogram (E) then
+ null;
+
+ elsif Is_Subprogram (E)
+ and then (not Comes_From_Source (E)
+ or else Chars (E) = Name_uCall)
+ then
+ null;
+
+ elsif
+ Nkind (Parent (Unit_Declaration_Node (E))) = N_Compilation_Unit
+ then
+ null;
+
+ elsif Nkind (Parent (E)) = N_Procedure_Specification
+ and then Null_Present (Parent (E))
+ and then Serious_Errors_Detected > 0
+ then
+ null;
+
+ else
+ Post_Error;
+ end if;
+
+ elsif Is_Entry (E) then
+ if not Has_Completion (E) and then
+ (Ekind (Scope (E)) = E_Protected_Object
+ or else Ekind (Scope (E)) = E_Protected_Type)
+ then
+ Post_Error;
+ end if;
+
+ elsif Is_Package_Or_Generic_Package (E) then
+ if Unit_Requires_Body (E) then
+ if not Has_Completion (E)
+ and then Nkind (Parent (Unit_Declaration_Node (E))) /=
+ N_Compilation_Unit
+ then
+ Post_Error;
+ end if;
+
+ elsif not Is_Child_Unit (E) then
+ May_Need_Implicit_Body (E);
+ end if;
+
+ -- A formal incomplete type (Ada 2012) does not require a completion;
+ -- other incomplete type declarations do.
+
+ elsif Ekind (E) = E_Incomplete_Type
+ and then No (Underlying_Type (E))
+ and then not Is_Generic_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);
+ Check_Conventions (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_CPP_Type_Has_No_Defaults --
+ ------------------------------------
+
+ procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id) is
+ Tdef : constant Node_Id := Type_Definition (Declaration_Node (T));
+ Clist : Node_Id;
+ Comp : Node_Id;
+
+ begin
+ -- Obtain the component list
+
+ if Nkind (Tdef) = N_Record_Definition then
+ Clist := Component_List (Tdef);
+ else pragma Assert (Nkind (Tdef) = N_Derived_Type_Definition);
+ Clist := Component_List (Record_Extension_Part (Tdef));
+ end if;
+
+ -- Check all components to ensure no default expressions
+
+ if Present (Clist) then
+ Comp := First (Component_Items (Clist));
+ while Present (Comp) loop
+ if Present (Expression (Comp)) then
+ Error_Msg_N
+ ("component of imported 'C'P'P type cannot have "
+ & "default expression", Expression (Comp));
+ end if;
+
+ Next (Comp);
+ end loop;
+ end if;
+ end Check_CPP_Type_Has_No_Defaults;
+
+ ----------------------------
+ -- 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)
+ and then not In_Instance
+ and then not In_Inlined_Body
+ then
+ if not OK_For_Limited_Init (T, Exp) then
+
+ -- In GNAT mode, this is just a warning, to allow it to be evilly
+ -- turned off. Otherwise it is a real error.
+
+ if GNAT_Mode then
+ Error_Msg_N
+ ("?cannot initialize entities of limited type!", Exp);
+
+ elsif Ada_Version < Ada_2005 then
+
+ -- The side effect removal machinery may generate illegal Ada
+ -- code to avoid the usage of access types and 'reference in
+ -- Alfa mode. Since this is legal code with respect to theorem
+ -- proving, do not emit the error.
+
+ if Alfa_Mode
+ and then Nkind (Exp) = N_Function_Call
+ and then Nkind (Parent (Exp)) = N_Object_Declaration
+ and then not Comes_From_Source
+ (Defining_Identifier (Parent (Exp)))
+ then
+ null;
+
+ else
+ Error_Msg_N
+ ("cannot initialize entities of limited type", Exp);
+ Explain_Limited_Type (T, Exp);
+ end if;
+
+ else
+ -- Specialize error message according to kind of illegal
+ -- initial expression.
+
+ if Nkind (Exp) = N_Type_Conversion
+ and then Nkind (Expression (Exp)) = N_Function_Call
+ then
+ Error_Msg_N
+ ("illegal context for call"
+ & " to function with limited result", Exp);
+
+ else
+ Error_Msg_N
+ ("initialization of limited object requires aggregate "
+ & "or function call", Exp);
+ end if;
+ end if;
+ end if;
+ end if;
+ end Check_Initialization;
+
+ ----------------------
+ -- Check_Interfaces --
+ ----------------------
+
+ procedure Check_Interfaces (N : Node_Id; Def : Node_Id) is
+ Parent_Type : constant Entity_Id := Etype (Defining_Identifier (N));
+
+ Iface : Node_Id;
+ Iface_Def : Node_Id;
+ Iface_Typ : Entity_Id;
+ Parent_Node : Node_Id;
+
+ Is_Task : Boolean := False;
+ -- Set True if parent type or any progenitor is a task interface
+
+ Is_Protected : Boolean := False;
+ -- Set True if parent type or any progenitor is a protected interface
+
+ procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id);
+ -- Check that a progenitor is compatible with declaration.
+ -- Error is posted on Error_Node.
+
+ ------------------
+ -- Check_Ifaces --
+ ------------------
+
+ procedure Check_Ifaces (Iface_Def : Node_Id; Error_Node : Node_Id) is
+ Iface_Id : constant Entity_Id :=
+ Defining_Identifier (Parent (Iface_Def));
+ Type_Def : Node_Id;
+
+ begin
+ if Nkind (N) = N_Private_Extension_Declaration then
+ Type_Def := N;
+ else
+ Type_Def := Type_Definition (N);
+ end if;
+
+ if Is_Task_Interface (Iface_Id) then
+ Is_Task := True;
+
+ elsif Is_Protected_Interface (Iface_Id) then
+ Is_Protected := True;
+ end if;
+
+ if Is_Synchronized_Interface (Iface_Id) then
+
+ -- A consequence of 3.9.4 (6/2) and 7.3 (7.2/2) is that a private
+ -- extension derived from a synchronized interface must explicitly
+ -- be declared synchronized, because the full view will be a
+ -- synchronized type.
+
+ if Nkind (N) = N_Private_Extension_Declaration then
+ if not Synchronized_Present (N) then
+ Error_Msg_NE
+ ("private extension of& must be explicitly synchronized",
+ N, Iface_Id);
+ end if;
+
+ -- However, by 3.9.4(16/2), a full type that is a record extension
+ -- is never allowed to derive from a synchronized interface (note
+ -- that interfaces must be excluded from this check, because those
+ -- are represented by derived type definitions in some cases).
+
+ elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition
+ and then not Interface_Present (Type_Definition (N))
+ then
+ Error_Msg_N ("record extension cannot derive from synchronized"
+ & " interface", Error_Node);
+ end if;
+ end if;
+
+ -- Check that the characteristics of the progenitor are compatible
+ -- with the explicit qualifier in the declaration.
+ -- The check only applies to qualifiers that come from source.
+ -- Limited_Present also appears in the declaration of corresponding
+ -- records, and the check does not apply to them.
+
+ if Limited_Present (Type_Def)
+ and then not
+ Is_Concurrent_Record_Type (Defining_Identifier (N))
+ then
+ if Is_Limited_Interface (Parent_Type)
+ and then not Is_Limited_Interface (Iface_Id)
+ then
+ Error_Msg_NE
+ ("progenitor& must be limited interface",
+ Error_Node, Iface_Id);
+
+ elsif
+ (Task_Present (Iface_Def)
+ or else Protected_Present (Iface_Def)
+ or else Synchronized_Present (Iface_Def))
+ and then Nkind (N) /= N_Private_Extension_Declaration
+ and then not Error_Posted (N)
+ then
+ Error_Msg_NE
+ ("progenitor& must be limited interface",
+ Error_Node, Iface_Id);
+ end if;
+
+ -- Protected interfaces can only inherit from limited, synchronized
+ -- or protected interfaces.
+
+ elsif Nkind (N) = N_Full_Type_Declaration
+ and then Protected_Present (Type_Def)
+ then
+ if Limited_Present (Iface_Def)
+ or else Synchronized_Present (Iface_Def)
+ or else Protected_Present (Iface_Def)
+ then
+ null;
+
+ elsif Task_Present (Iface_Def) then
+ Error_Msg_N ("(Ada 2005) protected interface cannot inherit"
+ & " from task interface", Error_Node);
+
+ else
+ Error_Msg_N ("(Ada 2005) protected interface cannot inherit"
+ & " from non-limited interface", Error_Node);
+ end if;
+
+ -- Ada 2005 (AI-345): Synchronized interfaces can only inherit from
+ -- limited and synchronized.
+
+ elsif Synchronized_Present (Type_Def) then
+ if Limited_Present (Iface_Def)
+ or else Synchronized_Present (Iface_Def)
+ then
+ null;
+
+ elsif Protected_Present (Iface_Def)
+ and then Nkind (N) /= N_Private_Extension_Declaration
+ then
+ Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
+ & " from protected interface", Error_Node);
+
+ elsif Task_Present (Iface_Def)
+ and then Nkind (N) /= N_Private_Extension_Declaration
+ then
+ Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
+ & " from task interface", Error_Node);
+
+ elsif not Is_Limited_Interface (Iface_Id) then
+ Error_Msg_N ("(Ada 2005) synchronized interface cannot inherit"
+ & " from non-limited interface", Error_Node);
+ end if;
+
+ -- Ada 2005 (AI-345): Task interfaces can only inherit from limited,
+ -- synchronized or task interfaces.
+
+ elsif Nkind (N) = N_Full_Type_Declaration
+ and then Task_Present (Type_Def)
+ then
+ if Limited_Present (Iface_Def)
+ or else Synchronized_Present (Iface_Def)
+ or else Task_Present (Iface_Def)
+ then
+ null;
+
+ elsif Protected_Present (Iface_Def) then
+ Error_Msg_N ("(Ada 2005) task interface cannot inherit from"
+ & " protected interface", Error_Node);
+
+ else
+ Error_Msg_N ("(Ada 2005) task interface cannot inherit from"
+ & " non-limited interface", Error_Node);
+ end if;
+ end if;
+ end Check_Ifaces;
+
+ -- Start of processing for Check_Interfaces
+
+ begin
+ if Is_Interface (Parent_Type) then
+ if Is_Task_Interface (Parent_Type) then
+ Is_Task := True;
+
+ elsif Is_Protected_Interface (Parent_Type) then
+ Is_Protected := True;
+ end if;
+ end if;
+
+ if Nkind (N) = N_Private_Extension_Declaration then
+
+ -- Check that progenitors are compatible with declaration
+
+ Iface := First (Interface_List (Def));
+ while Present (Iface) loop
+ Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
+
+ Parent_Node := Parent (Base_Type (Iface_Typ));
+ Iface_Def := Type_Definition (Parent_Node);
+
+ if not Is_Interface (Iface_Typ) then
+ Diagnose_Interface (Iface, Iface_Typ);
+
+ else
+ Check_Ifaces (Iface_Def, Iface);
+ end if;
+
+ Next (Iface);
+ end loop;
+
+ if Is_Task and Is_Protected then
+ Error_Msg_N
+ ("type cannot derive from task and protected interface", N);
+ end if;
+
+ return;
+ end if;
+
+ -- Full type declaration of derived type.
+ -- Check compatibility with parent if it is interface type
+
+ if Nkind (Type_Definition (N)) = N_Derived_Type_Definition
+ and then Is_Interface (Parent_Type)
+ then
+ Parent_Node := Parent (Parent_Type);
+
+ -- More detailed checks for interface varieties
+
+ Check_Ifaces
+ (Iface_Def => Type_Definition (Parent_Node),
+ Error_Node => Subtype_Indication (Type_Definition (N)));
+ end if;
+
+ Iface := First (Interface_List (Def));
+ while Present (Iface) loop
+ Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
+
+ Parent_Node := Parent (Base_Type (Iface_Typ));
+ Iface_Def := Type_Definition (Parent_Node);
+
+ if not Is_Interface (Iface_Typ) then
+ Diagnose_Interface (Iface, Iface_Typ);
+
+ else
+ -- "The declaration of a specific descendant of an interface
+ -- type freezes the interface type" RM 13.14
+
+ Freeze_Before (N, Iface_Typ);
+ Check_Ifaces (Iface_Def, Error_Node => Iface);
+ end if;
+
+ Next (Iface);
+ end loop;
+
+ if Is_Task and Is_Protected then
+ Error_Msg_N
+ ("type cannot derive from task and protected interface", N);
+ end if;
+ end Check_Interfaces;
+
+ ------------------------------------
+ -- 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 has been performed in Find_Type_Name, and we then recheck here
+ -- some properties that can't be checked on the partial view alone.
+ -- Otherwise we call Process_Discriminants.
+
+ procedure Check_Or_Process_Discriminants
+ (N : Node_Id;
+ T : Entity_Id;
+ Prev : Entity_Id := Empty)
+ is
+ begin
+ if Has_Discriminants (T) then
+
+ -- Discriminants are already set on T if they were already present
+ -- on the partial view. Make them visible to component declarations.
+
+ declare
+ D : Entity_Id;
+ -- Discriminant on T (full view) referencing expr on partial view
+
+ Prev_D : Entity_Id;
+ -- Entity of corresponding discriminant on partial view
+
+ New_D : Node_Id;
+ -- Discriminant specification for full view, expression is the
+ -- syntactic copy on full view (which has been checked for
+ -- conformance with partial view), only used here to post error
+ -- message.
+
+ begin
+ D := First_Discriminant (T);
+ New_D := First (Discriminant_Specifications (N));
+ while Present (D) loop
+ Prev_D := Current_Entity (D);
+ Set_Current_Entity (D);
+ Set_Is_Immediately_Visible (D);
+ Set_Homonym (D, Prev_D);
+
+ -- Handle the case where there is an untagged partial view and
+ -- the full view is tagged: must disallow discriminants with
+ -- defaults, unless compiling for Ada 2012, which allows a
+ -- limited tagged type to have defaulted discriminants (see
+ -- AI05-0214). However, suppress the error here if it was
+ -- already reported on the default expression of the partial
+ -- view.
+
+ if Is_Tagged_Type (T)
+ and then Present (Expression (Parent (D)))
+ and then (not Is_Limited_Type (Current_Scope)
+ or else Ada_Version < Ada_2012)
+ and then not Error_Posted (Expression (Parent (D)))
+ then
+ if Ada_Version >= Ada_2012 then
+ Error_Msg_N
+ ("discriminants of nonlimited tagged type cannot have"
+ & " defaults",
+ Expression (New_D));
+ else
+ Error_Msg_N
+ ("discriminants of tagged type cannot have defaults",
+ Expression (New_D));
+ end if;
+ end if;
+
+ -- Ada 2005 (AI-230): Access discriminant allowed in
+ -- non-limited record types.
+
+ if Ada_Version < Ada_2005 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);
+ Next (New_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_Has_Unknown_Discriminants
+ (Full, Has_Unknown_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: kind, convention, etc.
+
+ Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
+ Set_Convention (Full, Convention (Full_Base));
+
+ -- The Etype of the full view is inconsistent. Gigi needs to see the
+ -- structural full view, which is what the current scheme gives:
+ -- the Etype of the full view is the etype of the full base. However,
+ -- if the full base is a derived type, the full view then looks like
+ -- a subtype of the parent, not a subtype of the full base. If instead
+ -- we write:
+
+ -- Set_Etype (Full, Full_Base);
+
+ -- then we get inconsistencies in the front-end (confusion between
+ -- views). Several outstanding bugs are related to this ???
+
+ Set_Is_First_Subtype (Full, False);
+ Set_Scope (Full, Scope (Priv));
+ Set_Size_Info (Full, Full_Base);
+ Set_RM_Size (Full, RM_Size (Full_Base));
+ Set_Is_Itype (Full);
+
+ -- A subtype of a private-type-without-discriminants, whose full-view
+ -- has discriminants with default expressions, is not constrained!
+
+ if not Has_Discriminants (Priv) then
+ Set_Is_Constrained (Full, Is_Constrained (Full_Base));
+
+ if Has_Discriminants (Full_Base) then
+ Set_Discriminant_Constraint
+ (Full, Discriminant_Constraint (Full_Base));
+
+ -- The partial view may have been indefinite, the full view
+ -- might not be.
+
+ Set_Has_Unknown_Discriminants
+ (Full, Has_Unknown_Discriminants (Full_Base));
+ end if;
+ end if;
+
+ Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
+ Set_Depends_On_Private (Full, Has_Private_Component (Full));
+
+ -- Freeze the private subtype entity if its parent is delayed, and not
+ -- already frozen. We skip this processing if the type is an anonymous
+ -- subtype of a record component, or is the corresponding record of a
+ -- protected type, since ???
+
+ if not Is_Type (Scope (Full)) then
+ Set_Has_Delayed_Freeze (Full,
+ Has_Delayed_Freeze (Full_Base)
+ and then (not Is_Frozen (Full_Base)));
+ end if;
+
+ Set_Freeze_Node (Full, Empty);
+ Set_Is_Frozen (Full, False);
+ Set_Full_View (Priv, Full);
+
+ if Has_Discriminants (Full) then
+ Set_Stored_Constraint_From_Discriminant_Constraint (Full);
+ Set_Stored_Constraint (Priv, Stored_Constraint (Full));
+
+ if Has_Unknown_Discriminants (Full) then
+ Set_Discriminant_Constraint (Full, No_Elist);
+ end if;
+ end if;
+
+ if Ekind (Full_Base) = E_Record_Type
+ and then Has_Discriminants (Full_Base)
+ and then Has_Discriminants (Priv) -- might not, if errors
+ and then not Has_Unknown_Discriminants (Priv)
+ and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
+ then
+ Create_Constrained_Components
+ (Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
+
+ -- If the full base is itself derived from private, build a congruent
+ -- subtype of its underlying type, for use by the back end. For a
+ -- constrained record component, the declaration cannot be placed on
+ -- the component list, but it must nevertheless be built an analyzed, to
+ -- supply enough information for Gigi to compute the size of component.
+
+ elsif Ekind (Full_Base) in Private_Kind
+ and then Is_Derived_Type (Full_Base)
+ and then Has_Discriminants (Full_Base)
+ and then (Ekind (Current_Scope) /= E_Record_Subtype)
+ then
+ if not Is_Itype (Priv)
+ and then
+ Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
+ then
+ Build_Underlying_Full_View
+ (Parent (Priv), Full, Etype (Full_Base));
+
+ elsif Nkind (Related_Nod) = N_Component_Declaration then
+ Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
+ end if;
+
+ elsif Is_Record_Type (Full_Base) then
+
+ -- Show Full is simply a renaming of Full_Base
+
+ Set_Cloned_Subtype (Full, Full_Base);
+ end if;
+
+ -- It is unsafe to share the 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_Direct_Primitive_Operations (Full,
+ Direct_Primitive_Operations (Full_Base));
+
+ -- Inherit class_wide type of full_base in case the partial view was
+ -- not tagged. Otherwise it has already been created when the private
+ -- subtype was analyzed.
+
+ if No (Class_Wide_Type (Full)) then
+ Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
+ end if;
+
+ -- 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;
+
+ -- Link rep item chain, and also setting of Has_Predicates from private
+ -- subtype to full subtype, since we will need these on the full subtype
+ -- to create the predicate function. Note that the full subtype may
+ -- already have rep items, inherited from the full view of the base
+ -- type, so we must be sure not to overwrite these entries.
+
+ declare
+ Append : Boolean;
+ Item : Node_Id;
+ Next_Item : Node_Id;
+
+ begin
+ Item := First_Rep_Item (Full);
+
+ -- If no existing rep items on full type, we can just link directly
+ -- to the list of items on the private type.
+
+ if No (Item) then
+ Set_First_Rep_Item (Full, First_Rep_Item (Priv));
+
+ -- Otherwise, search to the end of items currently linked to the full
+ -- subtype and append the private items to the end. However, if Priv
+ -- and Full already have the same list of rep items, then the append
+ -- is not done, as that would create a circularity.
+
+ elsif Item /= First_Rep_Item (Priv) then
+ Append := True;
+
+ loop
+ Next_Item := Next_Rep_Item (Item);
+ exit when No (Next_Item);
+ Item := Next_Item;
+
+ -- If the private view has aspect specifications, the full view
+ -- inherits them. Since these aspects may already have been
+ -- attached to the full view during derivation, do not append
+ -- them if already present.
+
+ if Item = First_Rep_Item (Priv) then
+ Append := False;
+ exit;
+ end if;
+ end loop;
+
+ -- And link the private type items at the end of the chain
+
+ if Append then
+ Set_Next_Rep_Item (Item, First_Rep_Item (Priv));
+ end if;
+ end if;
+ end;
+
+ -- Make sure Has_Predicates is set on full type if it is set on the
+ -- private type. Note that it may already be set on the full type and
+ -- if so, we don't want to unset it.
+
+ if Has_Predicates (Priv) then
+ Set_Has_Predicates (Full);
+ 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_Possible_Deferred_Completion
+ (Prev_Id : Entity_Id;
+ Prev_Obj_Def : Node_Id;
+ Curr_Obj_Def : Node_Id);
+ -- Determine whether the two object definitions describe the partial
+ -- and the full view of a constrained deferred constant. Generate
+ -- a subtype for the full view and verify that it statically matches
+ -- the subtype of the partial view.
+
+ procedure Check_Recursive_Declaration (Typ : Entity_Id);
+ -- If deferred constant is an access type initialized with an allocator,
+ -- check whether there is an illegal recursion in the definition,
+ -- through a default value of some record subcomponent. This is normally
+ -- detected when generating init procs, but requires this additional
+ -- mechanism when expansion is disabled.
+
+ ----------------------------------------
+ -- Check_Possible_Deferred_Completion --
+ ----------------------------------------
+
+ procedure Check_Possible_Deferred_Completion
+ (Prev_Id : Entity_Id;
+ Prev_Obj_Def : Node_Id;
+ Curr_Obj_Def : Node_Id)
+ is
+ begin
+ if Nkind (Prev_Obj_Def) = N_Subtype_Indication
+ and then Present (Constraint (Prev_Obj_Def))
+ and then Nkind (Curr_Obj_Def) = N_Subtype_Indication
+ and then Present (Constraint (Curr_Obj_Def))
+ then
+ declare
+ Loc : constant Source_Ptr := Sloc (N);
+ Def_Id : constant Entity_Id := Make_Temporary (Loc, 'S');
+ Decl : constant Node_Id :=
+ Make_Subtype_Declaration (Loc,
+ Defining_Identifier => Def_Id,
+ Subtype_Indication =>
+ Relocate_Node (Curr_Obj_Def));
+
+ begin
+ Insert_Before_And_Analyze (N, Decl);
+ Set_Etype (Id, Def_Id);
+
+ if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then
+ Error_Msg_Sloc := Sloc (Prev_Id);
+ Error_Msg_N ("subtype does not statically match deferred " &
+ "declaration#", N);
+ end if;
+ end;
+ end if;
+ end Check_Possible_Deferred_Completion;
+
+ ---------------------------------
+ -- Check_Recursive_Declaration --
+ ---------------------------------
+
+ procedure Check_Recursive_Declaration (Typ : Entity_Id) is
+ Comp : Entity_Id;
+
+ begin
+ if Is_Record_Type (Typ) then
+ Comp := First_Component (Typ);
+ while Present (Comp) loop
+ if Comes_From_Source (Comp) then
+ if Present (Expression (Parent (Comp)))
+ and then Is_Entity_Name (Expression (Parent (Comp)))
+ and then Entity (Expression (Parent (Comp))) = Prev
+ then
+ Error_Msg_Sloc := Sloc (Parent (Comp));
+ Error_Msg_NE
+ ("illegal circularity with declaration for&#",
+ N, Comp);
+ return;
+
+ elsif Is_Record_Type (Etype (Comp)) then
+ Check_Recursive_Declaration (Etype (Comp));
+ end if;
+ end if;
+
+ Next_Component (Comp);
+ end loop;
+ end if;
+ end Check_Recursive_Declaration;
+
+ -- Start of processing for Constant_Redeclaration
+
+ begin
+ if Nkind (Parent (Prev)) = N_Object_Declaration then
+ if Nkind (Object_Definition
+ (Parent (Prev))) = N_Subtype_Indication
+ then
+ -- Find type of new declaration. The constraints of the two
+ -- views must match statically, but there is no point in
+ -- creating an itype for the full view.
+
+ if Nkind (Obj_Def) = N_Subtype_Indication then
+ Find_Type (Subtype_Mark (Obj_Def));
+ New_T := Entity (Subtype_Mark (Obj_Def));
+
+ else
+ Find_Type (Obj_Def);
+ New_T := Entity (Obj_Def);
+ end if;
+
+ T := Etype (Prev);
+
+ else
+ -- The full view may impose a constraint, even if the partial
+ -- view does not, so construct the subtype.
+
+ New_T := Find_Type_Of_Object (Obj_Def, N);
+ T := New_T;
+ end if;
+
+ else
+ -- Current declaration is illegal, diagnosed below in Enter_Name
+
+ T := Empty;
+ New_T := Any_Type;
+ end if;
+
+ -- If previous full declaration or a renaming 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 Nkind (Parent (Prev)) = N_Object_Renaming_Declaration
+ or else Present (Expression (Parent (Prev)))
+ or else Present (Full_View (Prev))
+ then
+ Enter_Name (Id);
+
+ -- Verify that types of both declarations match, or else that both types
+ -- are anonymous access types whose designated subtypes statically match
+ -- (as allowed in Ada 2005 by AI-385).
+
+ elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
+ and then
+ (Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
+ or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
+ or else Is_Access_Constant (Etype (New_T)) /=
+ Is_Access_Constant (Etype (Prev))
+ or else Can_Never_Be_Null (Etype (New_T)) /=
+ Can_Never_Be_Null (Etype (Prev))
+ or else Null_Exclusion_Present (Parent (Prev)) /=
+ Null_Exclusion_Present (Parent (Id))
+ or else not Subtypes_Statically_Match
+ (Designated_Type (Etype (Prev)),
+ Designated_Type (Etype (New_T))))
+ then
+ Error_Msg_Sloc := Sloc (Prev);
+ Error_Msg_N ("type does not match declaration#", N);
+ Set_Full_View (Prev, Id);
+ Set_Etype (Id, Any_Type);
+
+ elsif
+ Null_Exclusion_Present (Parent (Prev))
+ and then not Null_Exclusion_Present (N)
+ then
+ Error_Msg_Sloc := Sloc (Prev);
+ Error_Msg_N ("null-exclusion does not match declaration#", N);
+ Set_Full_View (Prev, Id);
+ Set_Etype (Id, Any_Type);
+
+ -- If so, process the full constant declaration
+
+ else
+ -- RM 7.4 (6): If the subtype defined by the subtype_indication in
+ -- the deferred declaration is constrained, then the subtype defined
+ -- by the subtype_indication in the full declaration shall match it
+ -- statically.
+
+ Check_Possible_Deferred_Completion
+ (Prev_Id => Prev,
+ Prev_Obj_Def => Object_Definition (Parent (Prev)),
+ Curr_Obj_Def => Obj_Def);
+
+ Set_Full_View (Prev, Id);
+ Set_Is_Public (Id, Is_Public (Prev));
+ Set_Is_Internal (Id);
+ Append_Entity (Id, Current_Scope);
+
+ -- Check ALIASED present if present before (RM 7.4(7))
+
+ if Is_Aliased (Prev)
+ and then not Aliased_Present (N)
+ then
+ Error_Msg_Sloc := Sloc (Prev);
+ Error_Msg_N ("ALIASED required (see declaration#)", N);
+ end if;
+
+ -- Check that placement is in private part and that the incomplete
+ -- declaration appeared in the visible part.
+
+ if Ekind (Current_Scope) = E_Package
+ and then not In_Private_Part (Current_Scope)
+ then
+ Error_Msg_Sloc := Sloc (Prev);
+ Error_Msg_N
+ ("full constant for declaration#"
+ & " must be in private part", N);
+
+ elsif Ekind (Current_Scope) = E_Package
+ and then
+ List_Containing (Parent (Prev)) /=
+ Visible_Declarations
+ (Specification (Unit_Declaration_Node (Current_Scope)))
+ then
+ Error_Msg_N
+ ("deferred constant must be declared in visible part",
+ Parent (Prev));
+ end if;
+
+ if Is_Access_Type (T)
+ and then Nkind (Expression (N)) = N_Allocator
+ then
+ Check_Recursive_Declaration (Designated_Type (T));
+ end if;
+
+ -- A deferred constant is a visible entity. If type has invariants,
+ -- verify that the initial value satisfies them.
+
+ if Expander_Active and then Has_Invariants (T) then
+ declare
+ Call : constant Node_Id :=
+ Make_Invariant_Call (New_Occurrence_Of (Prev, Sloc (N)));
+ begin
+ Insert_After (N, Call);
+ end;
+ end if;
+ end if;
+ end Constant_Redeclaration;
+
+ ----------------------
+ -- Constrain_Access --
+ ----------------------
+
+ procedure Constrain_Access
+ (Def_Id : in out Entity_Id;
+ S : Node_Id;
+ Related_Nod : Node_Id)
+ is
+ T : constant Entity_Id := Entity (Subtype_Mark (S));
+ Desig_Type : constant Entity_Id := Designated_Type (T);
+ Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
+ Constraint_OK : Boolean := True;
+
+ function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean;
+ -- Simple predicate to test for defaulted discriminants
+ -- Shouldn't this be in sem_util???
+
+ ---------------------------------
+ -- Has_Defaulted_Discriminants --
+ ---------------------------------
+
+ function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean is
+ begin
+ return Has_Discriminants (Typ)
+ and then Present (First_Discriminant (Typ))
+ and then Present
+ (Discriminant_Default_Value (First_Discriminant (Typ)));
+ end Has_Defaulted_Discriminants;
+
+ -- Start of processing for Constrain_Access
+
+ begin
+ if Is_Array_Type (Desig_Type) then
+ Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
+
+ elsif (Is_Record_Type (Desig_Type)
+ or else Is_Incomplete_Or_Private_Type (Desig_Type))
+ and then not Is_Constrained (Desig_Type)
+ then
+ -- ??? The following code is a temporary kludge to ignore a
+ -- discriminant constraint on access type if it is constraining
+ -- the current record. Avoid creating the implicit subtype of the
+ -- record we are currently compiling since right now, we cannot
+ -- handle these. For now, just return the access type itself.
+
+ if Desig_Type = Current_Scope
+ and then No (Def_Id)
+ then
+ Set_Ekind (Desig_Subtype, E_Record_Subtype);
+ Def_Id := Entity (Subtype_Mark (S));
+
+ -- This call added to ensure that the constraint is analyzed
+ -- (needed for a B test). Note that we still return early from
+ -- this procedure to avoid recursive processing. ???
+
+ Constrain_Discriminated_Type
+ (Desig_Subtype, S, Related_Nod, For_Access => True);
+ return;
+ end if;
+
+ -- Enforce rule that the constraint is illegal if there is an
+ -- unconstrained view of the designated type. This means that the
+ -- partial view (either a private type declaration or a derivation
+ -- from a private type) has no discriminants. (Defect Report
+ -- 8652/0008, Technical Corrigendum 1, checked by ACATS B371001).
+
+ -- Rule updated for Ada 2005: the private type is said to have
+ -- a constrained partial view, given that objects of the type
+ -- can be declared. Furthermore, the rule applies to all access
+ -- types, unlike the rule concerning default discriminants (see
+ -- RM 3.7.1(7/3))
+
+ if (Ekind (T) = E_General_Access_Type
+ or else Ada_Version >= Ada_2005)
+ and then Has_Private_Declaration (Desig_Type)
+ and then In_Open_Scopes (Scope (Desig_Type))
+ and then Has_Discriminants (Desig_Type)
+ then
+ 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 access type if designated " &
+ "type has constrained partial view", S);
+ end if;
+
+ exit;
+ end if;
+
+ Next (Decl);
+ end loop;
+ end if;
+ end;
+ end if;
+
+ Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
+ For_Access => True);
+
+ elsif (Is_Task_Type (Desig_Type)
+ or else Is_Protected_Type (Desig_Type))
+ and then not Is_Constrained (Desig_Type)
+ then
+ Constrain_Concurrent
+ (Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
+
+ else
+ Error_Msg_N ("invalid constraint on access type", S);
+ Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
+ Constraint_OK := False;
+ end if;
+
+ if No (Def_Id) then
+ Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
+ else
+ Set_Ekind (Def_Id, E_Access_Subtype);
+ end if;
+
+ if Constraint_OK then
+ Set_Etype (Def_Id, Base_Type (T));
+
+ if Is_Private_Type (Desig_Type) then
+ Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
+ end if;
+ else
+ Set_Etype (Def_Id, Any_Type);
+ end if;
+
+ Set_Size_Info (Def_Id, T);
+ Set_Is_Constrained (Def_Id, Constraint_OK);
+ Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
+ Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
+ Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
+
+ Conditional_Delay (Def_Id, T);
+
+ -- AI-363 : Subtypes of general access types whose designated types have
+ -- default discriminants are disallowed. In instances, the rule has to
+ -- be checked against the actual, of which T is the subtype. In a
+ -- generic body, the rule is checked assuming that the actual type has
+ -- defaulted discriminants.
+
+ if Ada_Version >= Ada_2005 or else Warn_On_Ada_2005_Compatibility then
+ if Ekind (Base_Type (T)) = E_General_Access_Type
+ and then Has_Defaulted_Discriminants (Desig_Type)
+ then
+ if Ada_Version < Ada_2005 then
+ Error_Msg_N
+ ("access subtype of general access type would not " &
+ "be allowed in Ada 2005?y?", S);
+ else
+ Error_Msg_N
+ ("access subtype of general access type not allowed", S);
+ end if;
+
+ Error_Msg_N ("\discriminants have defaults", S);
+
+ elsif Is_Access_Type (T)
+ and then Is_Generic_Type (Desig_Type)
+ and then Has_Discriminants (Desig_Type)
+ and then In_Package_Body (Current_Scope)
+ then
+ if Ada_Version < Ada_2005 then
+ Error_Msg_N
+ ("access subtype would not be allowed in generic body " &
+ "in Ada 2005?y?", S);
+ else
+ Error_Msg_N
+ ("access subtype not allowed in generic body", S);
+ end if;
+
+ Error_Msg_N
+ ("\designated type is a discriminated formal", S);
+ end if;
+ end if;
+ end Constrain_Access;
+
+ ---------------------
+ -- Constrain_Array --
+ ---------------------
+
+ procedure Constrain_Array
+ (Def_Id : in out Entity_Id;
+ SI : Node_Id;
+ Related_Nod : Node_Id;
+ Related_Id : Entity_Id;
+ Suffix : Character)
+ is
+ C : constant Node_Id := Constraint (SI);
+ Number_Of_Constraints : Nat := 0;
+ Index : Node_Id;
+ S, T : Entity_Id;
+ Constraint_OK : Boolean := True;
+
+ begin
+ T := Entity (Subtype_Mark (SI));
+
+ if Ekind (T) in Access_Kind then
+ T := Designated_Type (T);
+ end if;
+
+ -- If an index constraint follows a subtype mark in a subtype indication
+ -- then the type or subtype denoted by the subtype mark must not already
+ -- impose an index constraint. The subtype mark must denote either an
+ -- unconstrained array type or an access type whose designated type
+ -- is such an array type... (RM 3.6.1)
+
+ if Is_Constrained (T) then
+ Error_Msg_N ("array type is already constrained", Subtype_Mark (SI));
+ Constraint_OK := False;
+
+ else
+ S := First (Constraints (C));
+ while Present (S) loop
+ Number_Of_Constraints := Number_Of_Constraints + 1;
+ Next (S);
+ end loop;
+
+ -- In either case, the index constraint must provide a discrete
+ -- range for each index of the array type and the type of each
+ -- discrete range must be the same as that of the corresponding
+ -- index. (RM 3.6.1)
+
+ if Number_Of_Constraints /= Number_Dimensions (T) then
+ Error_Msg_NE ("incorrect number of index constraints for }", C, T);
+ Constraint_OK := False;
+
+ else
+ S := First (Constraints (C));
+ Index := First_Index (T);
+ Analyze (Index);
+
+ -- Apply constraints to each index type
+
+ for J in 1 .. Number_Of_Constraints loop
+ Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
+ Next (Index);
+ Next (S);
+ end loop;
+
+ end if;
+ end if;
+
+ if No (Def_Id) then
+ Def_Id :=
+ Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
+ Set_Parent (Def_Id, Related_Nod);
+
+ else
+ Set_Ekind (Def_Id, E_Array_Subtype);
+ end if;
+
+ Set_Size_Info (Def_Id, (T));
+ Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
+ Set_Etype (Def_Id, Base_Type (T));
+
+ if Constraint_OK then
+ Set_First_Index (Def_Id, First (Constraints (C)));
+ else
+ Set_First_Index (Def_Id, First_Index (T));
+ end if;
+
+ Set_Is_Constrained (Def_Id, True);
+ Set_Is_Aliased (Def_Id, Is_Aliased (T));
+ Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
+
+ Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
+ Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
+
+ -- A subtype does not inherit the packed_array_type of is parent. We
+ -- need to initialize the attribute because if Def_Id is previously
+ -- analyzed through a limited_with clause, it will have the attributes
+ -- of an incomplete type, one of which is an Elist that overlaps the
+ -- Packed_Array_Type field.
+
+ Set_Packed_Array_Type (Def_Id, Empty);
+
+ -- Build a freeze node if parent still needs one. Also make sure that
+ -- the Depends_On_Private status is set because the subtype will need
+ -- reprocessing at the time the base type does, and also we must set a
+ -- conditional delay.
+
+ Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
+ Conditional_Delay (Def_Id, T);
+ end Constrain_Array;
+
+ ------------------------------
+ -- Constrain_Component_Type --
+ ------------------------------
+
+ function Constrain_Component_Type
+ (Comp : Entity_Id;
+ Constrained_Typ : Entity_Id;
+ Related_Node : Node_Id;
+ Typ : Entity_Id;
+ Constraints : Elist_Id) return Entity_Id
+ is
+ Loc : constant Source_Ptr := Sloc (Constrained_Typ);
+ Compon_Type : constant Entity_Id := Etype (Comp);
+
+ function Build_Constrained_Array_Type
+ (Old_Type : Entity_Id) return Entity_Id;
+ -- If Old_Type is an array type, one of whose indexes is constrained
+ -- by a discriminant, build an Itype whose constraint replaces the
+ -- discriminant with its value in the constraint.
+
+ function Build_Constrained_Discriminated_Type
+ (Old_Type : Entity_Id) return Entity_Id;
+ -- Ditto for record components
+
+ function Build_Constrained_Access_Type
+ (Old_Type : Entity_Id) return Entity_Id;
+ -- Ditto for access types. Makes use of previous two functions, to
+ -- constrain designated type.
+
+ function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
+ -- T is an array or discriminated type, C is a list of constraints
+ -- that apply to T. This routine builds the constrained subtype.
+
+ function Is_Discriminant (Expr : Node_Id) return Boolean;
+ -- Returns True if Expr is a discriminant
+
+ function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
+ -- Find the value of discriminant Discrim in Constraint
+
+ -----------------------------------
+ -- Build_Constrained_Access_Type --
+ -----------------------------------
+
+ function Build_Constrained_Access_Type
+ (Old_Type : Entity_Id) return Entity_Id
+ is
+ Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
+ Itype : Entity_Id;
+ Desig_Subtype : Entity_Id;
+ Scop : Entity_Id;
+
+ begin
+ -- if the original access type was not embedded in the enclosing
+ -- type definition, there is no need to produce a new access
+ -- subtype. In fact every access type with an explicit constraint
+ -- generates an itype whose scope is the enclosing record.
+
+ if not Is_Type (Scope (Old_Type)) then
+ return Old_Type;
+
+ elsif Is_Array_Type (Desig_Type) then
+ Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
+
+ elsif Has_Discriminants (Desig_Type) then
+
+ -- This may be an access type to an enclosing record type for
+ -- which we are constructing the constrained components. Return
+ -- the enclosing record subtype. This is not always correct,
+ -- but avoids infinite recursion. ???
+
+ Desig_Subtype := Any_Type;
+
+ for J in reverse 0 .. Scope_Stack.Last loop
+ Scop := Scope_Stack.Table (J).Entity;
+
+ if Is_Type (Scop)
+ and then Base_Type (Scop) = Base_Type (Desig_Type)
+ then
+ Desig_Subtype := Scop;
+ end if;
+
+ exit when not Is_Type (Scop);
+ end loop;
+
+ if Desig_Subtype = Any_Type then
+ Desig_Subtype :=
+ Build_Constrained_Discriminated_Type (Desig_Type);
+ end if;
+
+ else
+ return Old_Type;
+ end if;
+
+ if Desig_Subtype /= Desig_Type then
+
+ -- The Related_Node better be here or else we won't be able
+ -- to attach new itypes to a node in the tree.
+
+ pragma Assert (Present (Related_Node));
+
+ Itype := Create_Itype (E_Access_Subtype, Related_Node);
+
+ Set_Etype (Itype, Base_Type (Old_Type));
+ Set_Size_Info (Itype, (Old_Type));
+ Set_Directly_Designated_Type (Itype, Desig_Subtype);
+ Set_Depends_On_Private (Itype, Has_Private_Component
+ (Old_Type));
+ Set_Is_Access_Constant (Itype, Is_Access_Constant
+ (Old_Type));
+
+ -- The new itype needs freezing when it depends on a not frozen
+ -- type and the enclosing subtype needs freezing.
+
+ if Has_Delayed_Freeze (Constrained_Typ)
+ and then not Is_Frozen (Constrained_Typ)
+ then
+ Conditional_Delay (Itype, Base_Type (Old_Type));
+ end if;
+
+ return Itype;
+
+ else
+ return Old_Type;
+ end if;
+ end Build_Constrained_Access_Type;
+
+ ----------------------------------
+ -- Build_Constrained_Array_Type --
+ ----------------------------------
+
+ function Build_Constrained_Array_Type
+ (Old_Type : Entity_Id) return Entity_Id
+ is
+ Lo_Expr : Node_Id;
+ Hi_Expr : Node_Id;
+ Old_Index : Node_Id;
+ Range_Node : Node_Id;
+ Constr_List : List_Id;
+
+ Need_To_Create_Itype : Boolean := False;
+
+ begin
+ Old_Index := First_Index (Old_Type);
+ while Present (Old_Index) loop
+ Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
+
+ if Is_Discriminant (Lo_Expr)
+ or else Is_Discriminant (Hi_Expr)
+ then
+ Need_To_Create_Itype := True;
+ end if;
+
+ Next_Index (Old_Index);
+ end loop;
+
+ if Need_To_Create_Itype then
+ Constr_List := New_List;
+
+ Old_Index := First_Index (Old_Type);
+ while Present (Old_Index) loop
+ Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
+
+ if Is_Discriminant (Lo_Expr) then
+ Lo_Expr := Get_Discr_Value (Lo_Expr);
+ end if;
+
+ if Is_Discriminant (Hi_Expr) then
+ Hi_Expr := Get_Discr_Value (Hi_Expr);
+ end if;
+
+ Range_Node :=
+ Make_Range
+ (Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
+
+ Append (Range_Node, To => Constr_List);
+
+ Next_Index (Old_Index);
+ end loop;
+
+ return Build_Subtype (Old_Type, Constr_List);
+
+ else
+ return Old_Type;
+ end if;
+ end Build_Constrained_Array_Type;
+
+ ------------------------------------------
+ -- Build_Constrained_Discriminated_Type --
+ ------------------------------------------
+
+ function Build_Constrained_Discriminated_Type
+ (Old_Type : Entity_Id) return Entity_Id
+ is
+ Expr : Node_Id;
+ Constr_List : List_Id;
+ Old_Constraint : Elmt_Id;
+
+ Need_To_Create_Itype : Boolean := False;
+
+ begin
+ Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
+ while Present (Old_Constraint) loop
+ Expr := Node (Old_Constraint);
+
+ if Is_Discriminant (Expr) then
+ Need_To_Create_Itype := True;
+ end if;
+
+ Next_Elmt (Old_Constraint);
+ end loop;
+
+ if Need_To_Create_Itype then
+ Constr_List := New_List;
+
+ Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
+ while Present (Old_Constraint) loop
+ Expr := Node (Old_Constraint);
+
+ if Is_Discriminant (Expr) then
+ Expr := Get_Discr_Value (Expr);
+ end if;
+
+ Append (New_Copy_Tree (Expr), To => Constr_List);
+
+ Next_Elmt (Old_Constraint);
+ end loop;
+
+ return Build_Subtype (Old_Type, Constr_List);
+
+ else
+ return Old_Type;
+ end if;
+ end Build_Constrained_Discriminated_Type;
+
+ -------------------
+ -- Build_Subtype --
+ -------------------
+
+ function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
+ Indic : Node_Id;
+ Subtyp_Decl : Node_Id;
+ Def_Id : Entity_Id;
+ Btyp : Entity_Id := Base_Type (T);
+
+ begin
+ -- The Related_Node better be here or else we won't be able to
+ -- attach new itypes to a node in the tree.
+
+ pragma Assert (Present (Related_Node));
+
+ -- If the view of the component's type is incomplete or private
+ -- with unknown discriminants, then the constraint must be applied
+ -- to the full type.
+
+ if Has_Unknown_Discriminants (Btyp)
+ and then Present (Underlying_Type (Btyp))
+ then
+ Btyp := Underlying_Type (Btyp);
+ end if;
+
+ Indic :=
+ Make_Subtype_Indication (Loc,
+ Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
+ Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
+
+ Def_Id := Create_Itype (Ekind (T), Related_Node);
+
+ Subtyp_Decl :=
+ Make_Subtype_Declaration (Loc,
+ Defining_Identifier => Def_Id,
+ Subtype_Indication => Indic);
+
+ Set_Parent (Subtyp_Decl, Parent (Related_Node));
+
+ -- Itypes must be analyzed with checks off (see package Itypes)
+
+ Analyze (Subtyp_Decl, Suppress => All_Checks);
+
+ return Def_Id;
+ end Build_Subtype;
+
+ ---------------------
+ -- Get_Discr_Value --
+ ---------------------
+
+ function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
+ D : Entity_Id;
+ E : Elmt_Id;
+
+ begin
+ -- The discriminant may be declared for the type, in which case we
+ -- find it by iterating over the list of discriminants. If the
+ -- discriminant is inherited from a parent type, it appears as the
+ -- corresponding discriminant of the current type. This will be the
+ -- case when constraining an inherited component whose constraint is
+ -- given by a discriminant of the parent.
+
+ D := First_Discriminant (Typ);
+ E := First_Elmt (Constraints);
+
+ while Present (D) loop
+ if D = Entity (Discrim)
+ or else D = CR_Discriminant (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.
+
+ -- Previous code checked for the present of the Stored_Constraint
+ -- list for the derived type, but did not use it at all. Should it
+ -- be present when the component is a discriminated task type?
+
+ if Is_Derived_Type (Typ)
+ and then Scope (Entity (Discrim)) = Etype (Typ)
+ then
+ D := First_Discriminant (Etype (Typ));
+ E := First_Elmt (Constraints);
+ while Present (D) loop
+ if D = Entity (Discrim) then
+ return Node (E);
+ end if;
+
+ Next_Discriminant (D);
+ Next_Elmt (E);
+ 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 are constrained the corresponding record of a
+ -- synchronized type that completes a private declaration.
+
+ or else (Is_Concurrent_Record_Type (Typ)
+ and then
+ Corresponding_Concurrent_Type (Typ) = Discrim_Scope)
+
+ -- or we have a class-wide type, in which case make sure the
+ -- discriminant found belongs to the root type.
+
+ or else (Is_Class_Wide_Type (Typ)
+ and then Etype (Typ) = Discrim_Scope));
+
+ return True;
+ end if;
+
+ -- In all other cases we have something wrong
+
+ return False;
+ end Is_Discriminant;
+
+ -- Start of processing for Constrain_Component_Type
+
+ begin
+ if Nkind (Parent (Comp)) = N_Component_Declaration
+ and then Comes_From_Source (Parent (Comp))
+ and then Comes_From_Source
+ (Subtype_Indication (Component_Definition (Parent (Comp))))
+ and then
+ Is_Entity_Name
+ (Subtype_Indication (Component_Definition (Parent (Comp))))
+ then
+ return Compon_Type;
+
+ elsif Is_Array_Type (Compon_Type) then
+ return Build_Constrained_Array_Type (Compon_Type);
+
+ elsif Has_Discriminants (Compon_Type) then
+ return Build_Constrained_Discriminated_Type (Compon_Type);
+
+ elsif Is_Access_Type (Compon_Type) then
+ return Build_Constrained_Access_Type (Compon_Type);
+
+ else
+ return Compon_Type;
+ end if;
+ end Constrain_Component_Type;
+
+ --------------------------
+ -- Constrain_Concurrent --
+ --------------------------
+
+ -- For concurrent types, the associated record value type carries the same
+ -- discriminants, so when we constrain a concurrent type, we must constrain
+ -- the corresponding record type as well.
+
+ procedure Constrain_Concurrent
+ (Def_Id : in out Entity_Id;
+ SI : Node_Id;
+ Related_Nod : Node_Id;
+ Related_Id : Entity_Id;
+ Suffix : Character)
+ is
+ -- Retrieve Base_Type to ensure getting to the concurrent type in the
+ -- case of a private subtype (needed when only doing semantic analysis).
+
+ T_Ent : Entity_Id := Base_Type (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);
+ 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));
+
+ -- As elsewhere, we do not want to create a freeze node for this itype
+ -- if it is created for a constrained component of an enclosing record
+ -- because references to outer discriminants will appear out of scope.
+
+ if Ekind (Scope (Prot_Subt)) /= E_Record_Type then
+ Conditional_Delay (T_Sub, Corr_Rec);
+ else
+ Set_Is_Frozen (T_Sub);
+ end if;
+
+ 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);
+
+ Check_SPARK_Restriction ("digits constraint is not allowed", S);
+
+ 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 to the known type, to reduce chances of cascaded errors
+
+ Set_Etype (Def_Id, E);
+ 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;
+
+ -- Ada 2005 (AI-412): Constrained incomplete subtypes are illegal.
+ -- Avoid generating an error for access-to-incomplete subtypes.
+
+ if Ada_Version >= Ada_2005
+ and then Ekind (T) = E_Incomplete_Type
+ and then Nkind (Parent (S)) = N_Subtype_Declaration
+ and then not Is_Itype (Def_Id)
+ then
+ -- A little sanity check, emit an error message if the type
+ -- has discriminants to begin with. Type T may be a regular
+ -- incomplete type or imported via a limited with clause.
+
+ if Has_Discriminants (T)
+ or else
+ (From_With_Type (T)
+ and then Present (Non_Limited_View (T))
+ and then Nkind (Parent (Non_Limited_View (T))) =
+ N_Full_Type_Declaration
+ and then Present (Discriminant_Specifications
+ (Parent (Non_Limited_View (T)))))
+ then
+ Error_Msg_N
+ ("(Ada 2005) incomplete subtype may not be constrained", C);
+ else
+ Error_Msg_N ("invalid constraint: type has no discriminant", C);
+ end if;
+
+ Fixup_Bad_Constraint;
+ return;
+
+ -- 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.
+
+ elsif 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_SPARK_Restriction ("digits constraint is not allowed", S);
+ Check_Restriction (No_Obsolescent_Features, C);
+
+ if Warn_On_Obsolescent_Feature then
+ Error_Msg_N
+ ("subtype digits constraint is an " &
+ "obsolescent feature (RM J.3(8))?j?", 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 be 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));
+
+ -- Capture values of bounds and generate temporaries for them if
+ -- needed, since checks may cause duplication of the expressions
+ -- which must not be reevaluated.
+
+ -- The forced evaluation removes side effects from expressions,
+ -- which should occur also in Alfa mode. Otherwise, we end up with
+ -- unexpected insertions of actions at places where this is not
+ -- supposed to occur, e.g. on default parameters of a call.
+
+ if Expander_Active then
+ Force_Evaluation (Low_Bound (R));
+ Force_Evaluation (High_Bound (R));
+ end if;
+
+ 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));
+
+ -- Check error of subtype with predicate in index constraint
+
+ else
+ Bad_Predicated_Subtype_Use
+ ("subtype& has predicate, not allowed in index constraint",
+ S, Entity (S));
+ 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));
+ 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);
+
+ 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_SPARK_Restriction ("delta constraint is not allowed", S);
+ Check_Restriction (No_Obsolescent_Features, C);
+
+ if Warn_On_Obsolescent_Feature then
+ Error_Msg_S
+ ("subtype delta constraint is an " &
+ "obsolescent feature (RM J.3(7))?j?");
+ 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;
+
+ -----------------------
+ -- Contain_Interface --
+ -----------------------
+
+ function Contain_Interface
+ (Iface : Entity_Id;
+ Ifaces : Elist_Id) return Boolean
+ is
+ Iface_Elmt : Elmt_Id;
+
+ begin
+ if Present (Ifaces) then
+ Iface_Elmt := First_Elmt (Ifaces);
+ while Present (Iface_Elmt) loop
+ if Node (Iface_Elmt) = Iface then
+ return True;
+ end if;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end if;
+
+ return False;
+ end Contain_Interface;
+
+ ---------------------------
+ -- 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
+ -- Defend against previous errors
+
+ if No (Scalar_Range (Derived_Type)) then
+ Check_Error_Detected;
+ return;
+ end if;
+
+ 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));
+ Set_Has_Pragma_Unmodified (Full, Has_Pragma_Unmodified (Priv));
+ Set_Has_Pragma_Unreferenced (Full, Has_Pragma_Unreferenced (Priv));
+ Set_Has_Pragma_Unreferenced_Objects
+ (Full, Has_Pragma_Unreferenced_Objects
+ (Priv));
+
+ Conditional_Delay (Full, Priv);
+
+ if Is_Tagged_Type (Full) then
+ Set_Direct_Primitive_Operations (Full,
+ Direct_Primitive_Operations (Priv));
+
+ if Is_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 Private 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_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_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));
+ Set_Packed_Array_Type (T1, Packed_Array_Type (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 component 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
+ then
+ Append_Elmt (Old_C, Comp_List);
+ end if;
+
+ Next_Component (Old_C);
+ end loop;
+ end if;
+ end Collect_Fixed_Components;
+
+ ---------------------------
+ -- Create_All_Components --
+ ---------------------------
+
+ procedure Create_All_Components is
+ Comp : Elmt_Id;
+
+ begin
+ Comp := First_Elmt (Comp_List);
+ while Present (Comp) loop
+ Old_C := Node (Comp);
+ New_C := Create_Component (Old_C);
+
+ Set_Etype
+ (New_C,
+ Constrain_Component_Type
+ (Old_C, Subt, Decl_Node, Typ, Constraints));
+ Set_Is_Public (New_C, Is_Public (Subt));
+
+ Next_Elmt (Comp);
+ end loop;
+ end Create_All_Components;
+
+ ----------------------
+ -- Create_Component --
+ ----------------------
+
+ function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
+ New_Compon : constant Entity_Id := New_Copy (Old_Compon);
+
+ begin
+ if Ekind (Old_Compon) = E_Discriminant
+ and then Is_Completely_Hidden (Old_Compon)
+ then
+ -- This is a shadow discriminant created for a discriminant of
+ -- the parent type, which needs to be present in the subtype.
+ -- Give the shadow discriminant an internal name that cannot
+ -- conflict with that of visible components.
+
+ Set_Chars (New_Compon, New_Internal_Name ('C'));
+ end if;
+
+ -- Set the parent so we have a proper link for freezing etc. This is
+ -- not a real parent pointer, since of course our parent does not own
+ -- up to us and reference us, we are an illegitimate child of the
+ -- original parent!
+
+ Set_Parent (New_Compon, Parent (Old_Compon));
+
+ -- If the old component's Esize was already determined and is a
+ -- static value, then the new component simply inherits it. Otherwise
+ -- the old component's size may require run-time determination, but
+ -- the new component's size still might be statically determinable
+ -- (if, for example it has a static constraint). In that case we want
+ -- Layout_Type to recompute the component's size, so we reset its
+ -- size and positional fields.
+
+ if Frontend_Layout_On_Target
+ and then not Known_Static_Esize (Old_Compon)
+ then
+ Set_Esize (New_Compon, Uint_0);
+ Init_Normalized_First_Bit (New_Compon);
+ Init_Normalized_Position (New_Compon);
+ Init_Normalized_Position_Max (New_Compon);
+ end if;
+
+ -- We do not want this node marked as Comes_From_Source, since
+ -- otherwise it would get first class status and a separate cross-
+ -- reference line would be generated. Illegitimate children do not
+ -- rate such recognition.
+
+ Set_Comes_From_Source (New_Compon, False);
+
+ -- But it is a real entity, and a birth certificate must be properly
+ -- registered by entering it into the entity list.
+
+ Enter_Name (New_Compon);
+
+ return New_Compon;
+ end Create_Component;
+
+ -----------------------
+ -- Is_Variant_Record --
+ -----------------------
+
+ function Is_Variant_Record (T : Entity_Id) return Boolean is
+ begin
+ return Nkind (Parent (T)) = N_Full_Type_Declaration
+ and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
+ and then Present (Component_List (Type_Definition (Parent (T))))
+ and then
+ Present
+ (Variant_Part (Component_List (Type_Definition (Parent (T)))));
+ end Is_Variant_Record;
+
+ -- Start of processing for Create_Constrained_Components
+
+ begin
+ pragma Assert (Subt /= Base_Type (Subt));
+ pragma Assert (Typ = Base_Type (Typ));
+
+ Set_First_Entity (Subt, Empty);
+ Set_Last_Entity (Subt, Empty);
+
+ -- Check whether constraint is fully static, in which case we can
+ -- optimize the list of components.
+
+ Discr_Val := First_Elmt (Constraints);
+ while Present (Discr_Val) loop
+ if not Is_OK_Static_Expression (Node (Discr_Val)) then
+ Is_Static := False;
+ exit;
+ end if;
+
+ Next_Elmt (Discr_Val);
+ end loop;
+
+ Set_Has_Static_Discriminants (Subt, Is_Static);
+
+ Push_Scope (Subt);
+
+ -- Inherit the discriminants of the parent type
+
+ Add_Discriminants : declare
+ Num_Disc : Int;
+ Num_Gird : Int;
+
+ begin
+ Num_Disc := 0;
+ Old_C := First_Discriminant (Typ);
+
+ while Present (Old_C) loop
+ Num_Disc := Num_Disc + 1;
+ New_C := Create_Component (Old_C);
+ Set_Is_Public (New_C, Is_Public (Subt));
+ Next_Discriminant (Old_C);
+ end loop;
+
+ -- For an untagged derived subtype, the number of discriminants may
+ -- be smaller than the number of inherited discriminants, because
+ -- several of them may be renamed by a single new discriminant or
+ -- constrained. In this case, add the hidden discriminants back into
+ -- the subtype, because they need to be present if the optimizer of
+ -- the GCC 4.x back-end decides to break apart assignments between
+ -- objects using the parent view into member-wise assignments.
+
+ Num_Gird := 0;
+
+ if Is_Derived_Type (Typ)
+ and then not Is_Tagged_Type (Typ)
+ then
+ Old_C := First_Stored_Discriminant (Typ);
+
+ while Present (Old_C) loop
+ Num_Gird := Num_Gird + 1;
+ Next_Stored_Discriminant (Old_C);
+ end loop;
+ end if;
+
+ if Num_Gird > Num_Disc then
+
+ -- Find out multiple uses of new discriminants, and add hidden
+ -- components for the extra renamed discriminants. We recognize
+ -- multiple uses through the Corresponding_Discriminant of a
+ -- new discriminant: if it constrains several old discriminants,
+ -- this field points to the last one in the parent type. The
+ -- stored discriminants of the derived type have the same name
+ -- as those of the parent.
+
+ declare
+ Constr : Elmt_Id;
+ New_Discr : Entity_Id;
+ Old_Discr : Entity_Id;
+
+ begin
+ Constr := First_Elmt (Stored_Constraint (Typ));
+ Old_Discr := First_Stored_Discriminant (Typ);
+ while Present (Constr) loop
+ if Is_Entity_Name (Node (Constr))
+ and then Ekind (Entity (Node (Constr))) = E_Discriminant
+ then
+ New_Discr := Entity (Node (Constr));
+
+ if Chars (Corresponding_Discriminant (New_Discr)) /=
+ Chars (Old_Discr)
+ then
+ -- The new discriminant has been used to rename a
+ -- subsequent old discriminant. Introduce a shadow
+ -- component for the current old discriminant.
+
+ New_C := Create_Component (Old_Discr);
+ Set_Original_Record_Component (New_C, Old_Discr);
+ end if;
+
+ else
+ -- The constraint has eliminated the old discriminant.
+ -- Introduce a shadow component.
+
+ New_C := Create_Component (Old_Discr);
+ Set_Original_Record_Component (New_C, Old_Discr);
+ end if;
+
+ Next_Elmt (Constr);
+ Next_Stored_Discriminant (Old_Discr);
+ end loop;
+ end;
+ end if;
+ end Add_Discriminants;
+
+ if Is_Static
+ and then Is_Variant_Record (Typ)
+ then
+ Collect_Fixed_Components (Typ);
+
+ Gather_Components (
+ Typ,
+ Component_List (Type_Definition (Parent (Typ))),
+ Governed_By => Assoc_List,
+ Into => Comp_List,
+ Report_Errors => Errors);
+ pragma Assert (not Errors);
+
+ Create_All_Components;
+
+ -- If the subtype declaration is created for a tagged type derivation
+ -- with constraints, we retrieve the record definition of the parent
+ -- type to select the components of the proper variant.
+
+ elsif Is_Static
+ and then Is_Tagged_Type (Typ)
+ and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
+ and then
+ Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
+ and then Is_Variant_Record (Parent_Type)
+ then
+ Collect_Fixed_Components (Typ);
+
+ Gather_Components (
+ Typ,
+ Component_List (Type_Definition (Parent (Parent_Type))),
+ Governed_By => Assoc_List,
+ Into => Comp_List,
+ Report_Errors => Errors);
+ pragma Assert (not Errors);
+
+ -- If the tagged derivation has a type extension, collect all the
+ -- new components therein.
+
+ if Present
+ (Record_Extension_Part (Type_Definition (Parent (Typ))))
+ then
+ Old_C := First_Component (Typ);
+ while Present (Old_C) loop
+ if Original_Record_Component (Old_C) = Old_C
+ and then Chars (Old_C) /= Name_uTag
+ and then Chars (Old_C) /= Name_uParent
+ then
+ Append_Elmt (Old_C, Comp_List);
+ end if;
+
+ Next_Component (Old_C);
+ end loop;
+ end if;
+
+ Create_All_Components;
+
+ else
+ -- If discriminants are not static, or if this is a multi-level type
+ -- extension, we have to include all components of the parent type.
+
+ Old_C := First_Component (Typ);
+ while Present (Old_C) loop
+ New_C := Create_Component (Old_C);
+
+ Set_Etype
+ (New_C,
+ Constrain_Component_Type
+ (Old_C, Subt, Decl_Node, Typ, Constraints));
+ Set_Is_Public (New_C, Is_Public (Subt));
+
+ Next_Component (Old_C);
+ end loop;
+ end if;
+
+ End_Scope;
+ end Create_Constrained_Components;
+
+ ------------------------------------------
+ -- Decimal_Fixed_Point_Type_Declaration --
+ ------------------------------------------
+
+ procedure Decimal_Fixed_Point_Type_Declaration
+ (T : Entity_Id;
+ Def : Node_Id)
+ is
+ Loc : constant Source_Ptr := Sloc (Def);
+ Digs_Expr : constant Node_Id := Digits_Expression (Def);
+ Delta_Expr : constant Node_Id := Delta_Expression (Def);
+ Implicit_Base : Entity_Id;
+ Digs_Val : Uint;
+ Delta_Val : Ureal;
+ Scale_Val : Uint;
+ Bound_Val : Ureal;
+
+ begin
+ Check_SPARK_Restriction
+ ("decimal fixed point type is not allowed", Def);
+ Check_Restriction (No_Fixed_Point, Def);
+
+ -- Create implicit base type
+
+ Implicit_Base :=
+ Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
+ Set_Etype (Implicit_Base, Implicit_Base);
+
+ -- Analyze and process delta expression
+
+ Analyze_And_Resolve (Delta_Expr, Universal_Real);
+
+ Check_Delta_Expression (Delta_Expr);
+ Delta_Val := Expr_Value_R (Delta_Expr);
+
+ -- Check delta is power of 10, and determine scale value from it
+
+ declare
+ Val : Ureal;
+
+ begin
+ Scale_Val := Uint_0;
+ Val := Delta_Val;
+
+ if Val < Ureal_1 then
+ while Val < Ureal_1 loop
+ Val := Val * Ureal_10;
+ Scale_Val := Scale_Val + 1;
+ end loop;
+
+ if Scale_Val > 18 then
+ Error_Msg_N ("scale exceeds maximum value of 18", Def);
+ Scale_Val := UI_From_Int (+18);
+ end if;
+
+ else
+ while Val > Ureal_1 loop
+ Val := Val / Ureal_10;
+ Scale_Val := Scale_Val - 1;
+ end loop;
+
+ if Scale_Val < -18 then
+ Error_Msg_N ("scale is less than minimum value of -18", Def);
+ Scale_Val := UI_From_Int (-18);
+ end if;
+ end if;
+
+ if Val /= Ureal_1 then
+ Error_Msg_N ("delta expression must be a power of 10", Def);
+ Delta_Val := Ureal_10 ** (-Scale_Val);
+ end if;
+ end;
+
+ -- Set delta, scale and small (small = delta for decimal type)
+
+ Set_Delta_Value (Implicit_Base, Delta_Val);
+ Set_Scale_Value (Implicit_Base, Scale_Val);
+ Set_Small_Value (Implicit_Base, Delta_Val);
+
+ -- Analyze and process digits expression
+
+ Analyze_And_Resolve (Digs_Expr, Any_Integer);
+ Check_Digits_Expression (Digs_Expr);
+ Digs_Val := Expr_Value (Digs_Expr);
+
+ if Digs_Val > 18 then
+ Digs_Val := UI_From_Int (+18);
+ Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
+ end if;
+
+ Set_Digits_Value (Implicit_Base, Digs_Val);
+ Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
+
+ -- Set range of base type from digits value for now. This will be
+ -- expanded to represent the true underlying base range by Freeze.
+
+ Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
+
+ -- Note: We leave size as 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.
+
+ pragma Assert (Esize (Implicit_Base) = Uint_0);
+
+ -- 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_Progenitor_Subprograms --
+ -----------------------------------
+
+ procedure Derive_Progenitor_Subprograms
+ (Parent_Type : Entity_Id;
+ Tagged_Type : Entity_Id)
+ is
+ E : Entity_Id;
+ Elmt : Elmt_Id;
+ Iface : Entity_Id;
+ Iface_Elmt : Elmt_Id;
+ Iface_Subp : Entity_Id;
+ New_Subp : Entity_Id := Empty;
+ Prim_Elmt : Elmt_Id;
+ Subp : Entity_Id;
+ Typ : Entity_Id;
+
+ begin
+ pragma Assert (Ada_Version >= Ada_2005
+ and then Is_Record_Type (Tagged_Type)
+ and then Is_Tagged_Type (Tagged_Type)
+ and then Has_Interfaces (Tagged_Type));
+
+ -- Step 1: Transfer to the full-view primitives associated with the
+ -- partial-view that cover interface primitives. Conceptually this
+ -- work should be done later by Process_Full_View; done here to
+ -- simplify its implementation at later stages. It can be safely
+ -- done here because interfaces must be visible in the partial and
+ -- private view (RM 7.3(7.3/2)).
+
+ -- Small optimization: This work is only required if the parent may
+ -- have entities whose Alias attribute reference an interface primitive.
+ -- Such a situation may occur if the parent is an abstract type and the
+ -- primitive has not been yet overridden or if the parent is a generic
+ -- formal type covering interfaces.
+
+ -- If the tagged type is not abstract, it cannot have abstract
+ -- primitives (the only entities in the list of primitives of
+ -- non-abstract tagged types that can reference abstract primitives
+ -- through its Alias attribute are the internal entities that have
+ -- attribute Interface_Alias, and these entities are generated later
+ -- by Add_Internal_Interface_Entities).
+
+ if In_Private_Part (Current_Scope)
+ and then (Is_Abstract_Type (Parent_Type)
+ or else
+ Is_Generic_Type (Parent_Type))
+ then
+ Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
+ while Present (Elmt) loop
+ Subp := Node (Elmt);
+
+ -- At this stage it is not possible to have entities in the list
+ -- of primitives that have attribute Interface_Alias.
+
+ pragma Assert (No (Interface_Alias (Subp)));
+
+ Typ := Find_Dispatching_Type (Ultimate_Alias (Subp));
+
+ if Is_Interface (Typ) then
+ E := Find_Primitive_Covering_Interface
+ (Tagged_Type => Tagged_Type,
+ Iface_Prim => Subp);
+
+ if Present (E)
+ and then Find_Dispatching_Type (Ultimate_Alias (E)) /= Typ
+ then
+ Replace_Elmt (Elmt, E);
+ Remove_Homonym (Subp);
+ end if;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+ end if;
+
+ -- Step 2: Add primitives of progenitors that are not implemented by
+ -- parents of Tagged_Type.
+
+ if Present (Interfaces (Base_Type (Tagged_Type))) then
+ Iface_Elmt := First_Elmt (Interfaces (Base_Type (Tagged_Type)));
+ while Present (Iface_Elmt) loop
+ Iface := Node (Iface_Elmt);
+
+ Prim_Elmt := First_Elmt (Primitive_Operations (Iface));
+ while Present (Prim_Elmt) loop
+ Iface_Subp := Node (Prim_Elmt);
+
+ -- Exclude derivation of predefined primitives except those
+ -- that come from source, or are inherited from one that comes
+ -- from source. Required to catch declarations of equality
+ -- operators of interfaces. For example:
+
+ -- type Iface is interface;
+ -- function "=" (Left, Right : Iface) return Boolean;
+
+ if not Is_Predefined_Dispatching_Operation (Iface_Subp)
+ or else Comes_From_Source (Ultimate_Alias (Iface_Subp))
+ then
+ E := Find_Primitive_Covering_Interface
+ (Tagged_Type => Tagged_Type,
+ Iface_Prim => Iface_Subp);
+
+ -- If not found we derive a new primitive leaving its alias
+ -- attribute referencing the interface primitive.
+
+ if No (E) then
+ Derive_Subprogram
+ (New_Subp, Iface_Subp, Tagged_Type, Iface);
+
+ -- Ada 2012 (AI05-0197): If the covering primitive's name
+ -- differs from the name of the interface primitive then it
+ -- is a private primitive inherited from a parent type. In
+ -- such case, given that Tagged_Type covers the interface,
+ -- the inherited private primitive becomes visible. For such
+ -- purpose we add a new entity that renames the inherited
+ -- private primitive.
+
+ elsif Chars (E) /= Chars (Iface_Subp) then
+ pragma Assert (Has_Suffix (E, 'P'));
+ Derive_Subprogram
+ (New_Subp, Iface_Subp, Tagged_Type, Iface);
+ Set_Alias (New_Subp, E);
+ Set_Is_Abstract_Subprogram (New_Subp,
+ Is_Abstract_Subprogram (E));
+
+ -- Propagate to the full view interface entities associated
+ -- with the partial view.
+
+ elsif In_Private_Part (Current_Scope)
+ and then Present (Alias (E))
+ and then Alias (E) = Iface_Subp
+ and then
+ List_Containing (Parent (E)) /=
+ Private_Declarations
+ (Specification
+ (Unit_Declaration_Node (Current_Scope)))
+ then
+ Append_Elmt (E, Primitive_Operations (Tagged_Type));
+ end if;
+ end if;
+
+ Next_Elmt (Prim_Elmt);
+ end loop;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end if;
+ end Derive_Progenitor_Subprograms;
+
+ -----------------------
+ -- Derive_Subprogram --
+ -----------------------
+
+ procedure Derive_Subprogram
+ (New_Subp : in out Entity_Id;
+ Parent_Subp : Entity_Id;
+ Derived_Type : Entity_Id;
+ Parent_Type : Entity_Id;
+ Actual_Subp : Entity_Id := Empty)
+ is
+ Formal : Entity_Id;
+ -- Formal parameter of parent primitive operation
+
+ Formal_Of_Actual : Entity_Id;
+ -- Formal parameter of actual operation, when the derivation is to
+ -- create a renaming for a primitive operation of an actual in an
+ -- instantiation.
+
+ New_Formal : Entity_Id;
+ -- Formal of inherited operation
+
+ Visible_Subp : Entity_Id := Parent_Subp;
+
+ function Is_Private_Overriding return Boolean;
+ -- If Subp is a private overriding of a visible operation, the inherited
+ -- 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 full 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
+ -- If the parent is not a dispatching operation there is no
+ -- need to investigate overridings
+
+ if not Is_Dispatching_Operation (Parent_Subp) then
+ return False;
+ end if;
+
+ -- The visible operation that is overridden is a homonym of the
+ -- parent subprogram. We scan the homonym chain to find the one
+ -- whose alias is the subprogram we are deriving.
+
+ Prev := Current_Entity (Parent_Subp);
+ while Present (Prev) loop
+ if 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;
+ 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)
+
+ -- Ada 2005 (AI-251): Handle also derivations of abstract
+ -- interface primitives.
+
+ or else (Is_Interface (Desig_Typ)
+ and then not Is_Class_Wide_Type (Desig_Typ))
+ 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
+ Build_Itype_Reference (Acc_Type, Parent (Derived_Type));
+
+ 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));
+ Set_Contract (New_Subp, Make_Contract (Sloc (New_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;
+
+ -- An inherited dispatching equality will be overridden by an internally
+ -- generated one, or by an explicit one, so preserve its name and thus
+ -- its entry in the dispatch table. Otherwise, if Parent_Subp is a
+ -- private operation it may become invisible if the full view has
+ -- progenitors, and the dispatch table will be malformed.
+ -- We check that the type is limited to handle the anomalous declaration
+ -- of Limited_Controlled, which is derived from a non-limited type, and
+ -- which is handled specially elsewhere as well.
+
+ elsif Chars (Parent_Subp) = Name_Op_Eq
+ and then Is_Dispatching_Operation (Parent_Subp)
+ and then Etype (Parent_Subp) = Standard_Boolean
+ and then not Is_Limited_Type (Etype (First_Formal (Parent_Subp)))
+ and then
+ Etype (First_Formal (Parent_Subp)) =
+ Etype (Next_Formal (First_Formal (Parent_Subp)))
+ 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;
+
+ -- Ada 2005 (AI-251): Regular derivation if the parent subprogram
+ -- overrides an interface primitive because interface primitives
+ -- must be visible in the partial view of the parent (RM 7.3 (7.3/2))
+
+ elsif Ada_Version >= Ada_2005
+ and then Is_Dispatching_Operation (Parent_Subp)
+ and then Covers_Some_Interface (Parent_Subp)
+ then
+ Set_Derived_Name;
+
+ -- Otherwise, 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));
+
+ if Present (Actual_Subp) then
+ Replace_Type (Actual_Subp, New_Subp);
+ else
+ Replace_Type (Parent_Subp, New_Subp);
+ end if;
+
+ Conditional_Delay (New_Subp, Parent_Subp);
+
+ -- If we are creating a renaming for a primitive operation of an
+ -- actual of a generic derived type, we must examine the signature
+ -- of the actual primitive, not that of the generic formal, which for
+ -- example may be an interface. However the name and initial value
+ -- of the inherited operation are those of the formal primitive.
+
+ Formal := First_Formal (Parent_Subp);
+
+ if Present (Actual_Subp) then
+ Formal_Of_Actual := First_Formal (Actual_Subp);
+ else
+ Formal_Of_Actual := Empty;
+ end if;
+
+ 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);
+
+ if Present (Formal_Of_Actual) then
+ Replace_Type (Formal_Of_Actual, New_Formal);
+ Next_Formal (Formal_Of_Actual);
+ else
+ Replace_Type (Formal, New_Formal);
+ end if;
+
+ 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 the derived type is a tagged generic formal type with unknown
+ -- discriminants, its convention is intrinsic (RM 6.3.1 (8)).
+
+ -- However, if the type is derived from a generic formal, the further
+ -- inherited subprogram has the convention of the non-generic ancestor.
+ -- Otherwise there would be no way to override the operation.
+ -- (This is subject to forthcoming ARG discussions).
+
+ if Is_Tagged_Type (Derived_Type) then
+ if Is_Generic_Type (Derived_Type)
+ and then Has_Unknown_Discriminants (Derived_Type)
+ then
+ Set_Convention (New_Subp, Convention_Intrinsic);
+
+ else
+ if Is_Generic_Type (Parent_Type)
+ and then Has_Unknown_Discriminants (Parent_Type)
+ then
+ Set_Convention (New_Subp, Convention (Alias (Parent_Subp)));
+ else
+ Set_Convention (New_Subp, Convention (Parent_Subp));
+ end if;
+ end if;
+ end if;
+
+ -- Predefined controlled operations retain their name even if the parent
+ -- is hidden (see above), but they are not primitive operations if the
+ -- ancestor is not visible, for example if the parent is a private
+ -- extension completed with a controlled extension. Note that a full
+ -- type that is controlled can break privacy: the flag Is_Controlled is
+ -- set on both views of the type.
+
+ if Is_Controlled (Parent_Type)
+ and then
+ (Chars (Parent_Subp) = Name_Initialize or else
+ Chars (Parent_Subp) = Name_Adjust or else
+ Chars (Parent_Subp) = Name_Finalize)
+ and then Is_Hidden (Parent_Subp)
+ and then not Is_Visibly_Controlled (Parent_Type)
+ then
+ Set_Is_Hidden (New_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));
+ else
+ Set_Has_Controlling_Result
+ (New_Subp, Has_Controlling_Result (Parent_Subp));
+ end if;
+
+ -- No_Return must be inherited properly. If this is overridden in the
+ -- case of a dispatching operation, then a check is made in Sem_Disp
+ -- that the overriding operation is also No_Return (no such check is
+ -- required for the case of non-dispatching operation.
+
+ Set_No_Return (New_Subp, No_Return (Parent_Subp));
+
+ -- A derived function with a controlling result is abstract. If the
+ -- Derived_Type is a nonabstract formal generic derived type, then
+ -- inherited operations are not abstract: the required check is done at
+ -- instantiation time. If the derivation is for a generic actual, the
+ -- function is not abstract unless the actual is.
+
+ if Is_Generic_Type (Derived_Type)
+ and then not Is_Abstract_Type (Derived_Type)
+ then
+ null;
+
+ -- Ada 2005 (AI-228): Calculate the "require overriding" and "abstract"
+ -- properties of the subprogram, as defined in RM-3.9.3(4/2-6/2).
+
+ elsif Ada_Version >= Ada_2005
+ and then (Is_Abstract_Subprogram (Alias (New_Subp))
+ or else (Is_Tagged_Type (Derived_Type)
+ and then Etype (New_Subp) = Derived_Type
+ and then not Is_Null_Extension (Derived_Type))
+ or else (Is_Tagged_Type (Derived_Type)
+ and then Ekind (Etype (New_Subp)) =
+ E_Anonymous_Access_Type
+ and then Designated_Type (Etype (New_Subp)) =
+ Derived_Type
+ and then not Is_Null_Extension (Derived_Type)))
+ and then No (Actual_Subp)
+ then
+ if not Is_Tagged_Type (Derived_Type)
+ or else Is_Abstract_Type (Derived_Type)
+ or else Is_Abstract_Subprogram (Alias (New_Subp))
+ then
+ Set_Is_Abstract_Subprogram (New_Subp);
+ else
+ Set_Requires_Overriding (New_Subp);
+ end if;
+
+ elsif Ada_Version < Ada_2005
+ and then (Is_Abstract_Subprogram (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_Subprogram (New_Subp);
+
+ -- AI05-0097 : an inherited operation that dispatches on result is
+ -- abstract if the derived type is abstract, even if the parent type
+ -- is concrete and the derived type is a null extension.
+
+ elsif Has_Controlling_Result (Alias (New_Subp))
+ and then Is_Abstract_Type (Etype (New_Subp))
+ then
+ Set_Is_Abstract_Subprogram (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_Type (Parent_Type)
+ and then not In_Open_Scopes (Scope (Parent_Type))
+ and then Is_Private_Overriding
+ and then Is_Abstract_Subprogram (Visible_Subp)
+ then
+ if No (Actual_Subp) then
+ Set_Alias (New_Subp, Visible_Subp);
+ Set_Is_Abstract_Subprogram (New_Subp, True);
+
+ else
+ -- If this is a derivation for an instance of a formal derived
+ -- type, abstractness comes from the primitive operation of the
+ -- actual, not from the operation inherited from the ancestor.
+
+ Set_Is_Abstract_Subprogram
+ (New_Subp, Is_Abstract_Subprogram (Actual_Subp));
+ end if;
+ 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 actual 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 (Actual_Subp)
+ then
+ Set_Is_Dispatching_Operation (New_Subp);
+
+ if Present (DTC_Entity (Actual_Subp)) then
+ Set_DTC_Entity (New_Subp, DTC_Entity (Actual_Subp));
+ Set_DT_Position (New_Subp, DT_Position (Actual_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);
+
+ function Check_Derived_Type return Boolean;
+ -- Check that all the entities derived from Parent_Type are found in
+ -- the list of primitives of Derived_Type exactly in the same order.
+
+ procedure Derive_Interface_Subprogram
+ (New_Subp : in out Entity_Id;
+ Subp : Entity_Id;
+ Actual_Subp : Entity_Id);
+ -- Derive New_Subp from the ultimate alias of the parent subprogram Subp
+ -- (which is an interface primitive). If Generic_Actual is present then
+ -- Actual_Subp is the actual subprogram corresponding with the generic
+ -- subprogram Subp.
+
+ function Check_Derived_Type return Boolean is
+ E : Entity_Id;
+ Elmt : Elmt_Id;
+ List : Elist_Id;
+ New_Subp : Entity_Id;
+ Op_Elmt : Elmt_Id;
+ Subp : Entity_Id;
+
+ begin
+ -- Traverse list of entities in the current scope searching for
+ -- an incomplete type whose full-view is derived type
+
+ E := First_Entity (Scope (Derived_Type));
+ while Present (E) and then E /= Derived_Type loop
+ if Ekind (E) = E_Incomplete_Type
+ and then Present (Full_View (E))
+ and then Full_View (E) = Derived_Type
+ then
+ -- Disable this test if Derived_Type completes an incomplete
+ -- type because in such case more primitives can be added
+ -- later to the list of primitives of Derived_Type by routine
+ -- Process_Incomplete_Dependents
+
+ return True;
+ end if;
+
+ E := Next_Entity (E);
+ end loop;
+
+ List := Collect_Primitive_Operations (Derived_Type);
+ Elmt := First_Elmt (List);
+
+ Op_Elmt := First_Elmt (Op_List);
+ while Present (Op_Elmt) loop
+ Subp := Node (Op_Elmt);
+ New_Subp := Node (Elmt);
+
+ -- At this early stage Derived_Type has no entities with attribute
+ -- Interface_Alias. In addition, such primitives are always
+ -- located at the end of the list of primitives of Parent_Type.
+ -- Therefore, if found we can safely stop processing pending
+ -- entities.
+
+ exit when Present (Interface_Alias (Subp));
+
+ -- Handle hidden entities
+
+ if not Is_Predefined_Dispatching_Operation (Subp)
+ and then Is_Hidden (Subp)
+ then
+ if Present (New_Subp)
+ and then Primitive_Names_Match (Subp, New_Subp)
+ then
+ Next_Elmt (Elmt);
+ end if;
+
+ else
+ if not Present (New_Subp)
+ or else Ekind (Subp) /= Ekind (New_Subp)
+ or else not Primitive_Names_Match (Subp, New_Subp)
+ then
+ return False;
+ end if;
+
+ Next_Elmt (Elmt);
+ end if;
+
+ Next_Elmt (Op_Elmt);
+ end loop;
+
+ return True;
+ end Check_Derived_Type;
+
+ ---------------------------------
+ -- Derive_Interface_Subprogram --
+ ---------------------------------
+
+ procedure Derive_Interface_Subprogram
+ (New_Subp : in out Entity_Id;
+ Subp : Entity_Id;
+ Actual_Subp : Entity_Id)
+ is
+ Iface_Subp : constant Entity_Id := Ultimate_Alias (Subp);
+ Iface_Type : constant Entity_Id := Find_Dispatching_Type (Iface_Subp);
+
+ begin
+ pragma Assert (Is_Interface (Iface_Type));
+
+ Derive_Subprogram
+ (New_Subp => New_Subp,
+ Parent_Subp => Iface_Subp,
+ Derived_Type => Derived_Type,
+ Parent_Type => Iface_Type,
+ Actual_Subp => Actual_Subp);
+
+ -- Given that this new interface entity corresponds with a primitive
+ -- of the parent that was not overridden we must leave it associated
+ -- with its parent primitive to ensure that it will share the same
+ -- dispatch table slot when overridden.
+
+ if No (Actual_Subp) then
+ Set_Alias (New_Subp, Subp);
+
+ -- For instantiations this is not needed since the previous call to
+ -- Derive_Subprogram leaves the entity well decorated.
+
+ else
+ pragma Assert (Alias (New_Subp) = Actual_Subp);
+ null;
+ end if;
+ end Derive_Interface_Subprogram;
+
+ -- Local variables
+
+ Alias_Subp : Entity_Id;
+ Act_List : Elist_Id;
+ Act_Elmt : Elmt_Id;
+ Act_Subp : Entity_Id := Empty;
+ Elmt : Elmt_Id;
+ Need_Search : Boolean := False;
+ New_Subp : Entity_Id := Empty;
+ Parent_Base : Entity_Id;
+ Subp : Entity_Id;
+
+ -- Start of processing for Derive_Subprograms
+
+ 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_List := No_Elist;
+ Act_Elmt := No_Elmt;
+ end if;
+
+ -- Derive primitives inherited from the parent. Note that if the generic
+ -- actual is present, this is not really a type derivation, it is a
+ -- completion within an instance.
+
+ -- Case 1: Derived_Type does not implement interfaces
+
+ if not Is_Tagged_Type (Derived_Type)
+ or else (not Has_Interfaces (Derived_Type)
+ and then not (Present (Generic_Actual)
+ and then Has_Interfaces (Generic_Actual)))
+ then
+ Elmt := First_Elmt (Op_List);
+ while Present (Elmt) loop
+ Subp := Node (Elmt);
+
+ -- Literals are derived earlier in the process of building the
+ -- derived type, and are skipped here.
+
+ if Ekind (Subp) = E_Enumeration_Literal then
+ null;
+
+ -- The actual is a direct descendant and the common primitive
+ -- operations appear in the same order.
+
+ -- If the generic parent type is present, the derived type is an
+ -- instance of a formal derived type, and within the instance its
+ -- operations are those of the actual. We derive from the formal
+ -- type but make the inherited operations aliases of the
+ -- corresponding operations of the actual.
+
+ else
+ pragma Assert (No (Node (Act_Elmt))
+ or else (Primitive_Names_Match (Subp, Node (Act_Elmt))
+ and then
+ Type_Conformant
+ (Subp, Node (Act_Elmt),
+ Skip_Controlling_Formals => True)));
+
+ Derive_Subprogram
+ (New_Subp, Subp, Derived_Type, Parent_Base, Node (Act_Elmt));
+
+ if Present (Act_Elmt) then
+ Next_Elmt (Act_Elmt);
+ end if;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ -- Case 2: Derived_Type implements interfaces
+
+ else
+ -- If the parent type has no predefined primitives we remove
+ -- predefined primitives from the list of primitives of generic
+ -- actual to simplify the complexity of this algorithm.
+
+ if Present (Generic_Actual) then
+ declare
+ Has_Predefined_Primitives : Boolean := False;
+
+ begin
+ -- Check if the parent type has predefined primitives
+
+ Elmt := First_Elmt (Op_List);
+ while Present (Elmt) loop
+ Subp := Node (Elmt);
+
+ if Is_Predefined_Dispatching_Operation (Subp)
+ and then not Comes_From_Source (Ultimate_Alias (Subp))
+ then
+ Has_Predefined_Primitives := True;
+ exit;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ -- Remove predefined primitives of Generic_Actual. We must use
+ -- an auxiliary list because in case of tagged types the value
+ -- returned by Collect_Primitive_Operations is the value stored
+ -- in its Primitive_Operations attribute (and we don't want to
+ -- modify its current contents).
+
+ if not Has_Predefined_Primitives then
+ declare
+ Aux_List : constant Elist_Id := New_Elmt_List;
+
+ begin
+ Elmt := First_Elmt (Act_List);
+ while Present (Elmt) loop
+ Subp := Node (Elmt);
+
+ if not Is_Predefined_Dispatching_Operation (Subp)
+ or else Comes_From_Source (Subp)
+ then
+ Append_Elmt (Subp, Aux_List);
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ Act_List := Aux_List;
+ end;
+ end if;
+
+ Act_Elmt := First_Elmt (Act_List);
+ Act_Subp := Node (Act_Elmt);
+ end;
+ end if;
+
+ -- Stage 1: If the generic actual is not present we derive the
+ -- primitives inherited from the parent type. If the generic parent
+ -- type is present, the derived type is an instance of a formal
+ -- derived type, and within the instance its operations are those of
+ -- the actual. We derive from the formal type but make the inherited
+ -- operations aliases of the corresponding operations of the actual.
+
+ Elmt := First_Elmt (Op_List);
+ while Present (Elmt) loop
+ Subp := Node (Elmt);
+ Alias_Subp := Ultimate_Alias (Subp);
+
+ -- Do not derive internal entities of the parent that link
+ -- interface primitives with their covering primitive. These
+ -- entities will be added to this type when frozen.
+
+ if Present (Interface_Alias (Subp)) then
+ goto Continue;
+ end if;
+
+ -- If the generic actual is present find the corresponding
+ -- operation in the generic actual. If the parent type is a
+ -- direct ancestor of the derived type then, even if it is an
+ -- interface, the operations are inherited from the primary
+ -- dispatch table and are in the proper order. If we detect here
+ -- that primitives are not in the same order we traverse the list
+ -- of primitive operations of the actual to find the one that
+ -- implements the interface primitive.
+
+ if Need_Search
+ or else
+ (Present (Generic_Actual)
+ and then Present (Act_Subp)
+ and then not
+ (Primitive_Names_Match (Subp, Act_Subp)
+ and then
+ Type_Conformant (Subp, Act_Subp,
+ Skip_Controlling_Formals => True)))
+ then
+ pragma Assert (not Is_Ancestor (Parent_Base, Generic_Actual,
+ Use_Full_View => True));
+
+ -- Remember that we need searching for all pending primitives
+
+ Need_Search := True;
+
+ -- Handle entities associated with interface primitives
+
+ if Present (Alias_Subp)
+ and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
+ and then not Is_Predefined_Dispatching_Operation (Subp)
+ then
+ -- Search for the primitive in the homonym chain
+
+ Act_Subp :=
+ Find_Primitive_Covering_Interface
+ (Tagged_Type => Generic_Actual,
+ Iface_Prim => Alias_Subp);
+
+ -- Previous search may not locate primitives covering
+ -- interfaces defined in generics units or instantiations.
+ -- (it fails if the covering primitive has formals whose
+ -- type is also defined in generics or instantiations).
+ -- In such case we search in the list of primitives of the
+ -- generic actual for the internal entity that links the
+ -- interface primitive and the covering primitive.
+
+ if No (Act_Subp)
+ and then Is_Generic_Type (Parent_Type)
+ then
+ -- This code has been designed to handle only generic
+ -- formals that implement interfaces that are defined
+ -- in a generic unit or instantiation. If this code is
+ -- needed for other cases we must review it because
+ -- (given that it relies on Original_Location to locate
+ -- the primitive of Generic_Actual that covers the
+ -- interface) it could leave linked through attribute
+ -- Alias entities of unrelated instantiations).
+
+ pragma Assert
+ (Is_Generic_Unit
+ (Scope (Find_Dispatching_Type (Alias_Subp)))
+ or else
+ Instantiation_Depth
+ (Sloc (Find_Dispatching_Type (Alias_Subp))) > 0);
+
+ declare
+ Iface_Prim_Loc : constant Source_Ptr :=
+ Original_Location (Sloc (Alias_Subp));
+
+ Elmt : Elmt_Id;
+ Prim : Entity_Id;
+
+ begin
+ Elmt :=
+ First_Elmt (Primitive_Operations (Generic_Actual));
+
+ Search : while Present (Elmt) loop
+ Prim := Node (Elmt);
+
+ if Present (Interface_Alias (Prim))
+ and then Original_Location
+ (Sloc (Interface_Alias (Prim))) =
+ Iface_Prim_Loc
+ then
+ Act_Subp := Alias (Prim);
+ exit Search;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop Search;
+ end;
+ end if;
+
+ pragma Assert (Present (Act_Subp)
+ or else Is_Abstract_Type (Generic_Actual)
+ or else Serious_Errors_Detected > 0);
+
+ -- Handle predefined primitives plus the rest of user-defined
+ -- primitives
+
+ else
+ Act_Elmt := First_Elmt (Act_List);
+ while Present (Act_Elmt) loop
+ Act_Subp := Node (Act_Elmt);
+
+ exit when Primitive_Names_Match (Subp, Act_Subp)
+ and then Type_Conformant
+ (Subp, Act_Subp,
+ Skip_Controlling_Formals => True)
+ and then No (Interface_Alias (Act_Subp));
+
+ Next_Elmt (Act_Elmt);
+ end loop;
+
+ if No (Act_Elmt) then
+ Act_Subp := Empty;
+ end if;
+ end if;
+ end if;
+
+ -- Case 1: If the parent is a limited interface then it has the
+ -- predefined primitives of synchronized interfaces. However, the
+ -- actual type may be a non-limited type and hence it does not
+ -- have such primitives.
+
+ if Present (Generic_Actual)
+ and then not Present (Act_Subp)
+ and then Is_Limited_Interface (Parent_Base)
+ and then Is_Predefined_Interface_Primitive (Subp)
+ then
+ null;
+
+ -- Case 2: Inherit entities associated with interfaces that were
+ -- not covered by the parent type. We exclude here null interface
+ -- primitives because they do not need special management.
+
+ -- We also exclude interface operations that are renamings. If the
+ -- subprogram is an explicit renaming of an interface primitive,
+ -- it is a regular primitive operation, and the presence of its
+ -- alias is not relevant: it has to be derived like any other
+ -- primitive.
+
+ elsif Present (Alias (Subp))
+ and then Nkind (Unit_Declaration_Node (Subp)) /=
+ N_Subprogram_Renaming_Declaration
+ and then Is_Interface (Find_Dispatching_Type (Alias_Subp))
+ and then not
+ (Nkind (Parent (Alias_Subp)) = N_Procedure_Specification
+ and then Null_Present (Parent (Alias_Subp)))
+ then
+ -- If this is an abstract private type then we transfer the
+ -- derivation of the interface primitive from the partial view
+ -- to the full view. This is safe because all the interfaces
+ -- must be visible in the partial view. Done to avoid adding
+ -- a new interface derivation to the private part of the
+ -- enclosing package; otherwise this new derivation would be
+ -- decorated as hidden when the analysis of the enclosing
+ -- package completes.
+
+ if Is_Abstract_Type (Derived_Type)
+ and then In_Private_Part (Current_Scope)
+ and then Has_Private_Declaration (Derived_Type)
+ then
+ declare
+ Partial_View : Entity_Id;
+ Elmt : Elmt_Id;
+ Ent : Entity_Id;
+
+ begin
+ Partial_View := First_Entity (Current_Scope);
+ loop
+ exit when No (Partial_View)
+ or else (Has_Private_Declaration (Partial_View)
+ and then
+ Full_View (Partial_View) = Derived_Type);
+
+ Next_Entity (Partial_View);
+ end loop;
+
+ -- If the partial view was not found then the source code
+ -- has errors and the derivation is not needed.
+
+ if Present (Partial_View) then
+ Elmt :=
+ First_Elmt (Primitive_Operations (Partial_View));
+ while Present (Elmt) loop
+ Ent := Node (Elmt);
+
+ if Present (Alias (Ent))
+ and then Ultimate_Alias (Ent) = Alias (Subp)
+ then
+ Append_Elmt
+ (Ent, Primitive_Operations (Derived_Type));
+ exit;
+ end if;
+
+ Next_Elmt (Elmt);
+ end loop;
+
+ -- If the interface primitive was not found in the
+ -- partial view then this interface primitive was
+ -- overridden. We add a derivation to activate in
+ -- Derive_Progenitor_Subprograms the machinery to
+ -- search for it.
+
+ if No (Elmt) then
+ Derive_Interface_Subprogram
+ (New_Subp => New_Subp,
+ Subp => Subp,
+ Actual_Subp => Act_Subp);
+ end if;
+ end if;
+ end;
+ else
+ Derive_Interface_Subprogram
+ (New_Subp => New_Subp,
+ Subp => Subp,
+ Actual_Subp => Act_Subp);
+ end if;
+
+ -- Case 3: Common derivation
+
+ else
+ Derive_Subprogram
+ (New_Subp => New_Subp,
+ Parent_Subp => Subp,
+ Derived_Type => Derived_Type,
+ Parent_Type => Parent_Base,
+ Actual_Subp => Act_Subp);
+ end if;
+
+ -- No need to update Act_Elm if we must search for the
+ -- corresponding operation in the generic actual
+
+ if not Need_Search
+ and then Present (Act_Elmt)
+ then
+ Next_Elmt (Act_Elmt);
+ Act_Subp := Node (Act_Elmt);
+ end if;
+
+ <<Continue>>
+ Next_Elmt (Elmt);
+ end loop;
+
+ -- Inherit additional operations from progenitors. If the derived
+ -- type is a generic actual, there are not new primitive operations
+ -- for the type because it has those of the actual, and therefore
+ -- nothing needs to be done. The renamings generated above are not
+ -- primitive operations, and their purpose is simply to make the
+ -- proper operations visible within an instantiation.
+
+ if No (Generic_Actual) then
+ Derive_Progenitor_Subprograms (Parent_Base, Derived_Type);
+ end if;
+ end if;
+
+ -- Final check: Direct descendants must have their primitives in the
+ -- same order. We exclude from this test untagged types and instances
+ -- of formal derived types. We skip this test if we have already
+ -- reported serious errors in the sources.
+
+ pragma Assert (not Is_Tagged_Type (Derived_Type)
+ or else Present (Generic_Actual)
+ or else Serious_Errors_Detected > 0
+ or else Check_Derived_Type);
+ 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
+ -- (???). This requires specific care for definition of stream
+ -- attributes. For details, see comments at the end of
+ -- Build_Derived_Numeric_Type.
+
+ 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
+ Parent_Type : Entity_Id;
+
+ function Comes_From_Generic (Typ : Entity_Id) return Boolean;
+ -- Check whether the parent type is a generic formal, or derives
+ -- directly or indirectly from one.
+
+ ------------------------
+ -- Comes_From_Generic --
+ ------------------------
+
+ function Comes_From_Generic (Typ : Entity_Id) return Boolean is
+ begin
+ if Is_Generic_Type (Typ) then
+ return True;
+
+ elsif Is_Generic_Type (Root_Type (Parent_Type)) then
+ return True;
+
+ elsif Is_Private_Type (Typ)
+ and then Present (Full_View (Typ))
+ and then Is_Generic_Type (Root_Type (Full_View (Typ)))
+ then
+ return True;
+
+ elsif Is_Generic_Actual_Type (Typ) then
+ return True;
+
+ else
+ return False;
+ end if;
+ end Comes_From_Generic;
+
+ -- Local variables
+
+ Def : constant Node_Id := Type_Definition (N);
+ Iface_Def : Node_Id;
+ Indic : constant Node_Id := Subtype_Indication (Def);
+ Extension : constant Node_Id := Record_Extension_Part (Def);
+ Parent_Node : Node_Id;
+ Taggd : Boolean;
+
+ -- Start of processing for Derived_Type_Declaration
+
+ begin
+ Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
+
+ -- Ada 2005 (AI-251): In case of interface derivation check that the
+ -- parent is also an interface.
+
+ if Interface_Present (Def) then
+ Check_SPARK_Restriction ("interface is not allowed", Def);
+
+ if not Is_Interface (Parent_Type) then
+ Diagnose_Interface (Indic, Parent_Type);
+
+ else
+ Parent_Node := Parent (Base_Type (Parent_Type));
+ Iface_Def := Type_Definition (Parent_Node);
+
+ -- Ada 2005 (AI-251): Limited interfaces can only inherit from
+ -- other limited interfaces.
+
+ if Limited_Present (Def) then
+ if Limited_Present (Iface_Def) then
+ null;
+
+ elsif Protected_Present (Iface_Def) then
+ Error_Msg_NE
+ ("descendant of& must be declared"
+ & " as a protected interface",
+ N, Parent_Type);
+
+ elsif Synchronized_Present (Iface_Def) then
+ Error_Msg_NE
+ ("descendant of& must be declared"
+ & " as a synchronized interface",
+ N, Parent_Type);
+
+ elsif Task_Present (Iface_Def) then
+ Error_Msg_NE
+ ("descendant of& must be declared as a task interface",
+ N, Parent_Type);
+
+ else
+ Error_Msg_N
+ ("(Ada 2005) limited interface cannot "
+ & "inherit from non-limited interface", Indic);
+ end if;
+
+ -- Ada 2005 (AI-345): Non-limited interfaces can only inherit
+ -- from non-limited or limited interfaces.
+
+ elsif not Protected_Present (Def)
+ and then not Synchronized_Present (Def)
+ and then not Task_Present (Def)
+ then
+ if Limited_Present (Iface_Def) then
+ null;
+
+ elsif Protected_Present (Iface_Def) then
+ Error_Msg_NE
+ ("descendant of& must be declared"
+ & " as a protected interface",
+ N, Parent_Type);
+
+ elsif Synchronized_Present (Iface_Def) then
+ Error_Msg_NE
+ ("descendant of& must be declared"
+ & " as a synchronized interface",
+ N, Parent_Type);
+
+ elsif Task_Present (Iface_Def) then
+ Error_Msg_NE
+ ("descendant of& must be declared as a task interface",
+ N, Parent_Type);
+ else
+ null;
+ end if;
+ end if;
+ end if;
+ end if;
+
+ if Is_Tagged_Type (Parent_Type)
+ and then Is_Concurrent_Type (Parent_Type)
+ and then not Is_Interface (Parent_Type)
+ then
+ Error_Msg_N
+ ("parent type of a record extension cannot be "
+ & "a synchronized tagged type (RM 3.9.1 (3/1))", N);
+ Set_Etype (T, Any_Type);
+ return;
+ end if;
+
+ -- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
+ -- interfaces
+
+ if Is_Tagged_Type (Parent_Type)
+ and then Is_Non_Empty_List (Interface_List (Def))
+ then
+ declare
+ Intf : Node_Id;
+ T : Entity_Id;
+
+ begin
+ Intf := First (Interface_List (Def));
+ while Present (Intf) loop
+ T := Find_Type_Of_Subtype_Indic (Intf);
+
+ if not Is_Interface (T) then
+ Diagnose_Interface (Intf, T);
+
+ -- Check the rules of 3.9.4(12/2) and 7.5(2/2) that disallow
+ -- a limited type from having a nonlimited progenitor.
+
+ elsif (Limited_Present (Def)
+ or else (not Is_Interface (Parent_Type)
+ and then Is_Limited_Type (Parent_Type)))
+ and then not Is_Limited_Interface (T)
+ then
+ Error_Msg_NE
+ ("progenitor interface& of limited type must be limited",
+ N, T);
+ end if;
+
+ Next (Intf);
+ end loop;
+ end;
+ end if;
+
+ if Parent_Type = Any_Type
+ or else Etype (Parent_Type) = Any_Type
+ or else (Is_Class_Wide_Type (Parent_Type)
+ and then Etype (Parent_Type) = T)
+ then
+ -- If Parent_Type is undefined or illegal, make new type into a
+ -- subtype of Any_Type, and set a few attributes to prevent cascaded
+ -- errors. If this is a self-definition, emit error now.
+
+ if T = Parent_Type
+ or else T = Etype (Parent_Type)
+ then
+ Error_Msg_N ("type cannot be used in its own definition", Indic);
+ end if;
+
+ Set_Ekind (T, Ekind (Parent_Type));
+ Set_Etype (T, Any_Type);
+ Set_Scalar_Range (T, Scalar_Range (Any_Type));
+
+ if Is_Tagged_Type (T)
+ and then Is_Record_Type (T)
+ then
+ Set_Direct_Primitive_Operations (T, New_Elmt_List);
+ end if;
+
+ return;
+ end if;
+
+ -- Ada 2005 (AI-251): The case in which the parent of the full-view is
+ -- an interface is special because the list of interfaces in the full
+ -- view can be given in any order. For example:
+
+ -- type A is interface;
+ -- type B is interface and A;
+ -- type D is new B with private;
+ -- private
+ -- type D is new A and B with null record; -- 1 --
+
+ -- In this case we perform the following transformation of -1-:
+
+ -- type D is new B and A with null record;
+
+ -- If the parent of the full-view covers the parent of the partial-view
+ -- we have two possible cases:
+
+ -- 1) They have the same parent
+ -- 2) The parent of the full-view implements some further interfaces
+
+ -- In both cases we do not need to perform the transformation. In the
+ -- first case the source program is correct and the transformation is
+ -- not needed; in the second case the source program does not fulfill
+ -- the no-hidden interfaces rule (AI-396) and the error will be reported
+ -- later.
+
+ -- This transformation not only simplifies the rest of the analysis of
+ -- this type declaration but also simplifies the correct generation of
+ -- the object layout to the expander.
+
+ if In_Private_Part (Current_Scope)
+ and then Is_Interface (Parent_Type)
+ then
+ declare
+ Iface : Node_Id;
+ Partial_View : Entity_Id;
+ Partial_View_Parent : Entity_Id;
+ New_Iface : Node_Id;
+
+ begin
+ -- Look for the associated private type declaration
+
+ Partial_View := First_Entity (Current_Scope);
+ loop
+ exit when No (Partial_View)
+ or else (Has_Private_Declaration (Partial_View)
+ and then Full_View (Partial_View) = T);
+
+ Next_Entity (Partial_View);
+ end loop;
+
+ -- If the partial view was not found then the source code has
+ -- errors and the transformation is not needed.
+
+ if Present (Partial_View) then
+ Partial_View_Parent := Etype (Partial_View);
+
+ -- If the parent of the full-view covers the parent of the
+ -- partial-view we have nothing else to do.
+
+ if Interface_Present_In_Ancestor
+ (Parent_Type, Partial_View_Parent)
+ then
+ null;
+
+ -- Traverse the list of interfaces of the full-view to look
+ -- for the parent of the partial-view and perform the tree
+ -- transformation.
+
+ else
+ Iface := First (Interface_List (Def));
+ while Present (Iface) loop
+ if Etype (Iface) = Etype (Partial_View) then
+ Rewrite (Subtype_Indication (Def),
+ New_Copy (Subtype_Indication
+ (Parent (Partial_View))));
+
+ New_Iface :=
+ Make_Identifier (Sloc (N), Chars (Parent_Type));
+ Append (New_Iface, Interface_List (Def));
+
+ -- Analyze the transformed code
+
+ Derived_Type_Declaration (T, N, Is_Completion);
+ return;
+ end if;
+
+ Next (Iface);
+ end loop;
+ end if;
+ end if;
+ end;
+ end if;
+
+ -- Only composite types other than array types are allowed to have
+ -- discriminants. In SPARK, no types are allowed to have discriminants.
+
+ if Present (Discriminant_Specifications (N)) then
+ if (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);
+ else
+ Check_SPARK_Restriction ("discriminant type is not allowed", N);
+ end if;
+ 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_In (Parent_Type, E_Void, E_Incomplete_Type) then
+ Error_Msg_N ("premature derivation of incomplete type", Indic);
+ return;
+
+ elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
+ and then not Comes_From_Generic (Parent_Type))
+ or else Has_Private_Component (Parent_Type)
+ then
+ -- The ancestor type of a formal type can be incomplete, in which
+ -- case only the operations of the partial view are available in the
+ -- generic. Subsequent checks may be required when the full view is
+ -- analyzed to verify that a derivation from a tagged type has an
+ -- extension.
+
+ if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
+ null;
+
+ elsif No (Underlying_Type (Parent_Type))
+ or else Has_Private_Component (Parent_Type)
+ then
+ Error_Msg_N
+ ("premature derivation of derived or private type", Indic);
+
+ -- Flag the type itself as being in error, this prevents some
+ -- nasty problems with subsequent uses of the malformed type.
+
+ Set_Error_Posted (T);
+
+ -- Check that within the immediate scope of an untagged partial
+ -- view it's illegal to derive from the partial view if the
+ -- full view is tagged. (7.3(7))
+
+ -- We verify that the Parent_Type is a partial view by checking
+ -- that it is not a Full_Type_Declaration (i.e. a private type or
+ -- private extension declaration), to distinguish a partial view
+ -- from a derivation from a private type which also appears as
+ -- E_Private_Type. If the parent base type is not declared in an
+ -- enclosing scope there is no need to check.
+
+ 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))
+ and then In_Open_Scopes (Scope (Base_Type (Parent_Type)))
+ then
+ Error_Msg_N
+ ("premature derivation from type with tagged full view",
+ Indic);
+ 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
+ if Is_Class_Wide_Type (Parent_Type) then
+ Error_Msg_N
+ ("parent type must not be a class-wide type", Indic);
+
+ -- Use specific type to prevent cascaded errors.
+
+ Parent_Type := Etype (Parent_Type);
+
+ else
+ Error_Msg_N
+ ("type derived from tagged type must have extension", Indic);
+ end if;
+ end if;
+ end if;
+
+ -- AI-443: Synchronized formal derived types require a private
+ -- extension. There is no point in checking the ancestor type or
+ -- the progenitors since the construct is wrong to begin with.
+
+ if Ada_Version >= Ada_2005
+ and then Is_Generic_Type (T)
+ and then Present (Original_Node (N))
+ then
+ declare
+ Decl : constant Node_Id := Original_Node (N);
+
+ begin
+ if Nkind (Decl) = N_Formal_Type_Declaration
+ and then Nkind (Formal_Type_Definition (Decl)) =
+ N_Formal_Derived_Type_Definition
+ and then Synchronized_Present (Formal_Type_Definition (Decl))
+ and then No (Extension)
+
+ -- Avoid emitting a duplicate error message
+
+ and then not Error_Posted (Indic)
+ then
+ Error_Msg_N
+ ("synchronized derived type must have extension", N);
+ end if;
+ end;
+ end if;
+
+ if Null_Exclusion_Present (Def)
+ and then not Is_Access_Type (Parent_Type)
+ then
+ Error_Msg_N ("null exclusion can only apply to an access type", N);
+ end if;
+
+ -- Avoid deriving parent primitives of underlying record views
+
+ Build_Derived_Type (N, Parent_Type, T, Is_Completion,
+ Derive_Subps => not Is_Underlying_Record_View (T));
+
+ -- AI-419: The parent type of an explicitly limited derived type must
+ -- be a limited type or a limited interface.
+
+ if Limited_Present (Def) then
+ Set_Is_Limited_Record (T);
+
+ if Is_Interface (T) then
+ Set_Is_Limited_Interface (T);
+ end if;
+
+ if not Is_Limited_Type (Parent_Type)
+ and then
+ (not Is_Interface (Parent_Type)
+ or else not Is_Limited_Interface (Parent_Type))
+ then
+ -- AI05-0096: a derivation in the private part of an instance is
+ -- legal if the generic formal is untagged limited, and the actual
+ -- is non-limited.
+
+ if Is_Generic_Actual_Type (Parent_Type)
+ and then In_Private_Part (Current_Scope)
+ and then
+ not Is_Tagged_Type
+ (Generic_Parent_Type (Parent (Parent_Type)))
+ then
+ null;
+
+ else
+ Error_Msg_NE
+ ("parent type& of limited type must be limited",
+ N, Parent_Type);
+ end if;
+ end if;
+ end if;
+
+ -- In SPARK, there are no derived type definitions other than type
+ -- extensions of tagged record types.
+
+ if No (Extension) then
+ Check_SPARK_Restriction ("derived type is not allowed", N);
+ end if;
+ end Derived_Type_Declaration;
+
+ ------------------------
+ -- Diagnose_Interface --
+ ------------------------
+
+ procedure Diagnose_Interface (N : Node_Id; E : Entity_Id) is
+ begin
+ if not Is_Interface (E)
+ and then E /= Any_Type
+ then
+ Error_Msg_NE ("(Ada 2005) & must be an interface", N, E);
+ end if;
+ end Diagnose_Interface;
+
+ ----------------------------------
+ -- 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 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);
+
+ -- Case of character literal
+
+ if Nkind (L) = N_Defining_Character_Literal then
+ Set_Is_Character_Type (T, True);
+
+ -- Check violation of No_Wide_Characters
+
+ if Restriction_Check_Required (No_Wide_Characters) then
+ Get_Name_String (Chars (L));
+
+ if Name_Len >= 3 and then Name_Buffer (1 .. 2) = "QW" then
+ Check_Restriction (No_Wide_Characters, L);
+ end if;
+ end if;
+ 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);
+
+ -- Initialize various fields of the type. Some of this information
+ -- may be overwritten later through rep.clauses.
+
+ Set_Scalar_Range (T, R_Node);
+ Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
+ Set_Enum_Esize (T);
+ Set_Enum_Pos_To_Rep (T, Empty);
+
+ -- 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_Hidden_Interface --
+ ---------------------------
+
+ function Find_Hidden_Interface
+ (Src : Elist_Id;
+ Dest : Elist_Id) return Entity_Id
+ is
+ Iface : Entity_Id;
+ Iface_Elmt : Elmt_Id;
+
+ begin
+ if Present (Src) and then Present (Dest) then
+ Iface_Elmt := First_Elmt (Src);
+ while Present (Iface_Elmt) loop
+ Iface := Node (Iface_Elmt);
+
+ if Is_Interface (Iface)
+ and then not Contain_Interface (Iface, Dest)
+ then
+ return Iface;
+ end if;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end if;
+
+ return Empty;
+ end Find_Hidden_Interface;
+
+ --------------------
+ -- 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;
+
+ procedure Check_Duplicate_Aspects;
+ -- Check that aspects specified in a completion have not been specified
+ -- already in the partial view. Type_Invariant and others can be
+ -- specified on either view but never on both.
+
+ procedure Tag_Mismatch;
+ -- Diagnose a tagged partial view whose full view is untagged.
+ -- We post the message on the full view, with a reference to
+ -- the previous partial view. The partial view can be private
+ -- or incomplete, and these are handled in a different manner,
+ -- so we determine the position of the error message from the
+ -- respective slocs of both.
+
+ -----------------------------
+ -- Check_Duplicate_Aspects --
+ -----------------------------
+ procedure Check_Duplicate_Aspects is
+ Prev_Aspects : constant List_Id := Aspect_Specifications (Prev_Par);
+ Full_Aspects : constant List_Id := Aspect_Specifications (N);
+ F_Spec, P_Spec : Node_Id;
+
+ begin
+ if Present (Prev_Aspects) and then Present (Full_Aspects) then
+ F_Spec := First (Full_Aspects);
+ while Present (F_Spec) loop
+ P_Spec := First (Prev_Aspects);
+ while Present (P_Spec) loop
+ if
+ Chars (Identifier (P_Spec)) = Chars (Identifier (F_Spec))
+ then
+ Error_Msg_N
+ ("aspect already specified in private declaration",
+ F_Spec);
+ Remove (F_Spec);
+ return;
+ end if;
+
+ Next (P_Spec);
+ end loop;
+
+ Next (F_Spec);
+ end loop;
+ end if;
+ end Check_Duplicate_Aspects;
+
+ ------------------
+ -- Tag_Mismatch --
+ ------------------
+
+ procedure Tag_Mismatch is
+ begin
+ if Sloc (Prev) < Sloc (Id) then
+ if Ada_Version >= Ada_2012
+ and then Nkind (N) = N_Private_Type_Declaration
+ then
+ Error_Msg_NE
+ ("declaration of private } must be a tagged type ", Id, Prev);
+ else
+ Error_Msg_NE
+ ("full declaration of } must be a tagged type ", Id, Prev);
+ end if;
+ else
+ if Ada_Version >= Ada_2012
+ and then Nkind (N) = N_Private_Type_Declaration
+ then
+ Error_Msg_NE
+ ("declaration of private } must be a tagged type ", Prev, Id);
+ else
+ Error_Msg_NE
+ ("full declaration of } must be a tagged type ", Prev, Id);
+ end if;
+ end if;
+ end Tag_Mismatch;
+
+ -- Start of processing for Find_Type_Name
+
+ begin
+ -- Find incomplete declaration, if one was given
+
+ Prev := Current_Entity_In_Scope (Id);
+
+ -- New type declaration
+
+ if No (Prev) then
+ Enter_Name (Id);
+ return Id;
+
+ -- Previous declaration exists
+
+ else
+ Prev_Par := Parent (Prev);
+
+ -- Error if not incomplete/private case except if previous
+ -- declaration is implicit, etc. Enter_Name will emit error if
+ -- appropriate.
+
+ if not Is_Incomplete_Or_Private_Type (Prev) then
+ Enter_Name (Id);
+ New_Id := Id;
+
+ -- Check invalid completion of private or incomplete type
+
+ elsif not Nkind_In (N, N_Full_Type_Declaration,
+ N_Task_Type_Declaration,
+ N_Protected_Type_Declaration)
+ and then
+ (Ada_Version < Ada_2012
+ or else not Is_Incomplete_Type (Prev)
+ or else not Nkind_In (N, N_Private_Type_Declaration,
+ N_Private_Extension_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;
+
+ -- If this is a repeated incomplete declaration, no further
+ -- checks are possible.
+
+ if Nkind (N) = N_Incomplete_Type_Declaration then
+ return Prev;
+ end if;
+
+ -- Case of full declaration of incomplete type
+
+ elsif Ekind (Prev) = E_Incomplete_Type
+ and then (Ada_Version < Ada_2012
+ or else No (Full_View (Prev))
+ or else not Is_Private_Type (Full_View (Prev)))
+ 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;
+
+ -- If the incomplete view is tagged, a class_wide type has been
+ -- created already. Use it for the private type as well, in order
+ -- to prevent multiple incompatible class-wide types that may be
+ -- created for self-referential anonymous access components.
+
+ if Is_Tagged_Type (Prev)
+ and then Present (Class_Wide_Type (Prev))
+ then
+ Set_Ekind (Id, Ekind (Prev)); -- will be reset later
+ Set_Class_Wide_Type (Id, Class_Wide_Type (Prev));
+
+ -- If the incomplete type is completed by a private declaration
+ -- the class-wide type remains associated with the incomplete
+ -- type, to prevent order-of-elaboration issues in gigi, else
+ -- we associate the class-wide type with the known full view.
+
+ if Nkind (N) /= N_Private_Type_Declaration then
+ Set_Etype (Class_Wide_Type (Id), Id);
+ end if;
+ end if;
+
+ -- Case of full declaration of private type
+
+ else
+ -- If the private type was a completion of an incomplete type then
+ -- update Prev to reference the private type
+
+ if Ada_Version >= Ada_2012
+ and then Ekind (Prev) = E_Incomplete_Type
+ and then Present (Full_View (Prev))
+ and then Is_Private_Type (Full_View (Prev))
+ then
+ Prev := Full_View (Prev);
+ Prev_Par := Parent (Prev);
+ end if;
+
+ 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_In (N, N_Task_Type_Declaration,
+ N_Protected_Type_Declaration)
+ then
+ Error_Msg_N
+ ("completion of nonlimited type cannot be limited", N);
+
+ elsif Ekind (Prev) = E_Record_Type_With_Private
+ and then Nkind_In (N, N_Task_Type_Declaration,
+ N_Protected_Type_Declaration)
+ then
+ if not Is_Limited_Record (Prev) then
+ Error_Msg_N
+ ("completion of nonlimited type cannot be limited", N);
+
+ elsif No (Interface_List (N)) then
+ Error_Msg_N
+ ("completion of tagged private type must be tagged",
+ N);
+ end if;
+
+ elsif Nkind (N) = N_Full_Type_Declaration
+ and then
+ Nkind (Type_Definition (N)) = N_Record_Definition
+ and then Interface_Present (Type_Definition (N))
+ then
+ Error_Msg_N
+ ("completion of private type cannot be an interface", N);
+ end if;
+
+ -- Ada 2005 (AI-251): Private extension declaration of a task
+ -- type or a protected type. This case arises when covering
+ -- interface types.
+
+ elsif Nkind_In (N, N_Task_Type_Declaration,
+ N_Protected_Type_Declaration)
+ then
+ null;
+
+ elsif Nkind (N) /= N_Full_Type_Declaration
+ or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
+ then
+ Error_Msg_N
+ ("full view of private extension must be an extension", N);
+
+ elsif not (Abstract_Present (Parent (Prev)))
+ and then Abstract_Present (Type_Definition (N))
+ then
+ Error_Msg_N
+ ("full view of non-abstract extension cannot be abstract", N);
+ end if;
+
+ if not In_Private_Part (Current_Scope) then
+ Error_Msg_N
+ ("declaration of full view must appear in private part", N);
+ end if;
+
+ if Ada_Version >= Ada_2012 then
+ Check_Duplicate_Aspects;
+ end if;
+
+ Copy_And_Swap (Prev, Id);
+ Set_Has_Private_Declaration (Prev);
+ Set_Has_Private_Declaration (Id);
+
+ -- Preserve aspect and iterator flags that may have been set on
+ -- the partial view.
+
+ Set_Has_Delayed_Aspects (Prev, Has_Delayed_Aspects (Id));
+ Set_Has_Implicit_Dereference (Prev, Has_Implicit_Dereference (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 partial 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 partial view can have an associated class-wide
+ -- type due to use of the class attribute, and in this case the full
+ -- type must also be tagged. This Ada 95 usage is deprecated in favor
+ -- of incomplete tagged declarations, but we check for it.
+
+ if Is_Type (Prev)
+ and then (Is_Tagged_Type (Prev)
+ or else Present (Class_Wide_Type (Prev)))
+ then
+ -- Ada 2012 (AI05-0162): A private type may be the completion of
+ -- an incomplete type
+
+ if Ada_Version >= Ada_2012
+ and then Is_Incomplete_Type (Prev)
+ and then Nkind_In (N, N_Private_Type_Declaration,
+ N_Private_Extension_Declaration)
+ then
+ -- No need to check private extensions since they are tagged
+
+ if Nkind (N) = N_Private_Type_Declaration
+ and then not Tagged_Present (N)
+ then
+ Tag_Mismatch;
+ end if;
+
+ -- The full declaration is either a tagged type (including
+ -- a synchronized type that implements interfaces) or a
+ -- type extension, otherwise this is an error.
+
+ elsif Nkind_In (N, N_Task_Type_Declaration,
+ N_Protected_Type_Declaration)
+ then
+ if No (Interface_List (N))
+ and then not Error_Posted (N)
+ then
+ Tag_Mismatch;
+ end if;
+
+ elsif Nkind (Type_Definition (N)) = N_Record_Definition then
+
+ -- Indicate that the previous declaration (tagged incomplete
+ -- or private declaration) requires the same on the full one.
+
+ if not Tagged_Present (Type_Definition (N)) then
+ Tag_Mismatch;
+ Set_Is_Tagged_Type (Id);
+ 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 some attributes to produce a usable full view
+
+ Set_Is_Tagged_Type (Id);
+ end if;
+
+ else
+ Tag_Mismatch;
+ end if;
+ end if;
+
+ if Present (Prev)
+ and then Nkind (Parent (Prev)) = N_Incomplete_Type_Declaration
+ and then Present (Premature_Use (Parent (Prev)))
+ then
+ Error_Msg_Sloc := Sloc (N);
+ Error_Msg_N
+ ("\full declaration #", Premature_Use (Parent (Prev)));
+ end if;
+
+ return New_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 Nkind_In (Def_Kind, N_Constrained_Array_Definition,
+ 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, P));
+ end if;
+
+ -- Ada 2005 AI-406: the object definition in an object declaration
+ -- can be an access definition.
+
+ elsif Def_Kind = N_Access_Definition then
+ T := Access_Definition (Related_Nod, Obj_Def);
+
+ Set_Is_Local_Anonymous_Access
+ (T,
+ V => (Ada_Version < Ada_2012)
+ or else (Nkind (P) /= N_Object_Declaration)
+ or else Is_Library_Level_Entity (Defining_Identifier (P)));
+
+ -- Otherwise, the object definition is just a subtype_mark
+
+ else
+ T := Process_Subtype (Obj_Def, Related_Nod);
+
+ -- If expansion is disabled an object definition that is an aggregate
+ -- will not get expanded and may lead to scoping problems in the back
+ -- end, if the object is referenced in an inner scope. In that case
+ -- create an itype reference for the object definition now. This
+ -- may be redundant in some cases, but harmless.
+
+ if Is_Itype (T)
+ and then Nkind (Related_Nod) = N_Object_Declaration
+ and then ASIS_Mode
+ then
+ Build_Itype_Reference (T, Related_Nod);
+ end if;
+ 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;
+
+ -- Check No_Wide_Characters restriction
+
+ Check_Wide_Character_Restriction (Typ, S);
+
+ 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);
+ Max_Digs_Val : constant Uint := Digits_Value (Standard_Long_Long_Float);
+ 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, and possibly a specified range, allows
+ -- derivation from specified type
+
+ function Find_Base_Type return Entity_Id;
+ -- Find a predefined base type that Def can derive from, or generate
+ -- an error and substitute Long_Long_Float if none exists.
+
+ ---------------------
+ -- Can_Derive_From --
+ ---------------------
+
+ function Can_Derive_From (E : Entity_Id) return Boolean is
+ Spec : constant Entity_Id := Real_Range_Specification (Def);
+
+ begin
+ -- Check specified "digits" constraint
+
+ if Digs_Val > Digits_Value (E) then
+ return False;
+ end if;
+
+ -- Avoid types not matching pragma Float_Representation, if present
+
+ if (Opt.Float_Format = 'I' and then Float_Rep (E) /= IEEE_Binary)
+ or else
+ (Opt.Float_Format = 'V' and then Float_Rep (E) /= VAX_Native)
+ then
+ return False;
+ end if;
+
+ -- Check for matching range, if specified
+
+ 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;
+
+ --------------------
+ -- Find_Base_Type --
+ --------------------
+
+ function Find_Base_Type return Entity_Id is
+ Choice : Elmt_Id := First_Elmt (Predefined_Float_Types);
+
+ begin
+ -- Iterate over the predefined types in order, returning the first
+ -- one that Def can derive from.
+
+ while Present (Choice) loop
+ if Can_Derive_From (Node (Choice)) then
+ return Node (Choice);
+ end if;
+
+ Next_Elmt (Choice);
+ end loop;
+
+ -- If we can't derive from any existing type, use Long_Long_Float
+ -- and give appropriate message explaining the problem.
+
+ if Digs_Val > Max_Digs_Val then
+ -- It might be the case that there is a type with the requested
+ -- range, just not the combination of digits and range.
+
+ Error_Msg_N
+ ("no predefined type has requested range and precision",
+ Real_Range_Specification (Def));
+
+ else
+ Error_Msg_N
+ ("range too large for any predefined type",
+ Real_Range_Specification (Def));
+ end if;
+
+ return Standard_Long_Long_Float;
+ end Find_Base_Type;
+
+ -- 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);
+
+ -- Check that requested number of digits is not too high.
+
+ if Digs_Val > Max_Digs_Val then
+ -- The check for Max_Base_Digits may be somewhat expensive, as it
+ -- requires reading System, so only do it when necessary.
+
+ declare
+ Max_Base_Digits : constant Uint :=
+ Expr_Value
+ (Expression
+ (Parent (RTE (RE_Max_Base_Digits))));
+
+ begin
+ if Digs_Val > Max_Base_Digits then
+ Error_Msg_Uint_1 := Max_Base_Digits;
+ Error_Msg_N ("digits value out of range, maximum is ^", Digs);
+
+ elsif No (Real_Range_Specification (Def)) then
+ Error_Msg_Uint_1 := Max_Digs_Val;
+ Error_Msg_N ("types with more than ^ digits need range spec "
+ & "(RM 3.5.7(6))", Digs);
+ end if;
+ end;
+ end if;
+
+ -- Find a suitable type to derive from or complain and use a substitute
+
+ Base_Typ := Find_Base_Type;
+
+ -- 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_Float_Rep (Implicit_Base, Float_Rep (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 Root_Corresponding_Discriminant
+ (Discr : Entity_Id) return Entity_Id;
+ -- Given a discriminant, traverse the chain of inherited discriminants
+ -- and return the topmost discriminant.
+
+ 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.
+
+ -------------------------------------
+ -- Root_Corresponding_Discriminant --
+ -------------------------------------
+
+ function Root_Corresponding_Discriminant
+ (Discr : Entity_Id) return Entity_Id
+ is
+ D : Entity_Id;
+
+ begin
+ D := Discr;
+ while Present (Corresponding_Discriminant (D)) loop
+ D := Corresponding_Discriminant (D);
+ end loop;
+
+ return D;
+ end Root_Corresponding_Discriminant;
+
+ ------------------------------
+ -- 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;
+
+ -- Local Variables
+
+ Result : Node_Or_Entity_Id;
+
+ -- Start of processing for Get_Discriminant_Value
+
+ begin
+ -- ??? This routine is a gigantic mess and will be deleted. For the
+ -- time being just test for the trivial case before calling recurse.
+
+ if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
+ declare
+ D : Entity_Id;
+ E : Elmt_Id;
+
+ begin
+ D := First_Discriminant (Typ_For_Constraint);
+ E := First_Elmt (Constraint);
+ while Present (D) loop
+ if Chars (D) = Chars (Discriminant) then
+ return Node (E);
+ end if;
+
+ Next_Discriminant (D);
+ Next_Elmt (E);
+ end loop;
+ end;
+ end if;
+
+ Result := Search_Derivation_Levels
+ (Typ_For_Constraint, Constraint, False);
+
+ -- ??? hack to disappear when this routine is gone
+
+ if Nkind (Result) = N_Defining_Identifier then
+ declare
+ D : Entity_Id;
+ E : Elmt_Id;
+
+ begin
+ D := First_Discriminant (Typ_For_Constraint);
+ E := First_Elmt (Constraint);
+ while Present (D) loop
+ if Root_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
+ procedure Set_Anonymous_Type (Id : Entity_Id);
+ -- Id denotes the entity of an access discriminant or anonymous
+ -- access component. Set the type of Id to either the same type of
+ -- Old_C or create a new one depending on whether the parent and
+ -- the child types are in the same scope.
+
+ ------------------------
+ -- Set_Anonymous_Type --
+ ------------------------
+
+ procedure Set_Anonymous_Type (Id : Entity_Id) is
+ Old_Typ : constant Entity_Id := Etype (Old_C);
+
+ begin
+ if Scope (Parent_Base) = Scope (Derived_Base) then
+ Set_Etype (Id, Old_Typ);
+
+ -- The parent and the derived type are in two different scopes.
+ -- Reuse the type of the original discriminant / component by
+ -- copying it in order to preserve all attributes.
+
+ else
+ declare
+ Typ : constant Entity_Id := New_Copy (Old_Typ);
+
+ begin
+ Set_Etype (Id, Typ);
+
+ -- Since we do not generate component declarations for
+ -- inherited components, associate the itype with the
+ -- derived type.
+
+ Set_Associated_Node_For_Itype (Typ, Parent (Derived_Base));
+ Set_Scope (Typ, Derived_Base);
+ end;
+ end if;
+ end Set_Anonymous_Type;
+
+ -- Local variables and constants
+
+ New_C : constant Entity_Id := New_Copy (Old_C);
+
+ Corr_Discrim : Entity_Id;
+ Discrim : Entity_Id;
+
+ -- Start of processing for Inherit_Component
+
+ 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;
+
+ -- Set the proper type of an access discriminant
+
+ if Ekind (New_C) = E_Discriminant
+ and then Ekind (Etype (New_C)) = E_Anonymous_Access_Type
+ then
+ Set_Anonymous_Type (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
+
+ -- Set the proper type of an anonymous access component
+
+ if Ekind (Etype (New_C)) = E_Anonymous_Access_Type then
+ Set_Anonymous_Type (New_C);
+
+ elsif (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
+ -- The current component introduces a circularity of the
+ -- following kind:
+
+ -- limited with Pack_2;
+ -- package Pack_1 is
+ -- type T_1 is tagged record
+ -- Comp : access Pack_2.T_2;
+ -- ...
+ -- end record;
+ -- end Pack_1;
+
+ -- with Pack_1;
+ -- package Pack_2 is
+ -- type T_2 is new Pack_1.T_1 with ...;
+ -- end Pack_2;
+
+ Set_Etype
+ (New_C,
+ Constrain_Component_Type
+ (Old_C, Derived_Base, N, Parent_Base, Discs));
+ end if;
+ end if;
+
+ -- In derived tagged types it is illegal to reference a non
+ -- discriminant component in the parent type. To catch this, mark
+ -- these components with an Ekind of E_Void. This will be reset in
+ -- Record_Type_Definition after processing the record extension of
+ -- the derived type.
+
+ -- If the declaration is a private extension, there is no further
+ -- record extension to process, and the components retain their
+ -- current kind, because they are visible at this point.
+
+ if Is_Tagged and then Ekind (New_C) = E_Component
+ and then Nkind (N) /= N_Private_Extension_Declaration
+ then
+ Set_Ekind (New_C, E_Void);
+ end if;
+
+ if Plain_Discrim then
+ Set_Corresponding_Discriminant (New_C, Old_C);
+ Build_Discriminal (New_C);
+
+ -- If we are explicitly inheriting a stored discriminant it will be
+ -- completely hidden.
+
+ elsif Stored_Discrim then
+ Set_Corresponding_Discriminant (New_C, Empty);
+ Set_Discriminal (New_C, Empty);
+ Set_Is_Completely_Hidden (New_C);
+
+ -- Set the Original_Record_Component of each discriminant in the
+ -- derived base to point to the corresponding stored that we just
+ -- created.
+
+ Discrim := First_Discriminant (Derived_Base);
+ while Present (Discrim) loop
+ Corr_Discrim := Corresponding_Discriminant (Discrim);
+
+ -- Corr_Discrim could be missing in an error situation
+
+ if Present (Corr_Discrim)
+ and then Original_Record_Component (Corr_Discrim) = Old_C
+ then
+ Set_Original_Record_Component (Discrim, New_C);
+ end if;
+
+ Next_Discriminant (Discrim);
+ end loop;
+
+ Append_Entity (New_C, Derived_Base);
+ end if;
+
+ if not Is_Tagged then
+ Append_Elmt (Old_C, Assoc_List);
+ Append_Elmt (New_C, Assoc_List);
+ end if;
+ end Inherit_Component;
+
+ -- Variables local to Inherit_Component
+
+ Loc : constant Source_Ptr := Sloc (N);
+
+ Parent_Discrim : Entity_Id;
+ Stored_Discrim : Entity_Id;
+ D : Entity_Id;
+ Component : Entity_Id;
+
+ -- Start of processing for Inherit_Components
+
+ begin
+ if not Is_Tagged then
+ Append_Elmt (Parent_Base, Assoc_List);
+ Append_Elmt (Derived_Base, Assoc_List);
+ end if;
+
+ -- Inherit parent discriminants if needed
+
+ if Inherit_Discr then
+ Parent_Discrim := First_Discriminant (Parent_Base);
+ while Present (Parent_Discrim) loop
+ Inherit_Component (Parent_Discrim, Plain_Discrim => True);
+ Next_Discriminant (Parent_Discrim);
+ end loop;
+ end if;
+
+ -- Create explicit stored discrims for untagged types when necessary
+
+ if not Has_Unknown_Discriminants (Derived_Base)
+ and then Has_Discriminants (Parent_Base)
+ and then not Is_Tagged
+ and then
+ (not Inherit_Discr
+ or else First_Discriminant (Parent_Base) /=
+ First_Stored_Discriminant (Parent_Base))
+ then
+ Stored_Discrim := First_Stored_Discriminant (Parent_Base);
+ while Present (Stored_Discrim) loop
+ Inherit_Component (Stored_Discrim, Stored_Discrim => True);
+ Next_Stored_Discriminant (Stored_Discrim);
+ end loop;
+ end if;
+
+ -- See if we can apply the second transformation for derived types, as
+ -- explained in point 6. in the comments above Build_Derived_Record_Type
+ -- This is achieved by appending Derived_Base discriminants into Discs,
+ -- which has the side effect of returning a non empty Discs list to the
+ -- caller of Inherit_Components, which is what we want. This must be
+ -- done for private derived types if there are explicit stored
+ -- discriminants, to ensure that we can retrieve the values of the
+ -- constraints provided in the ancestors.
+
+ if Inherit_Discr
+ and then Is_Empty_Elmt_List (Discs)
+ and then Present (First_Discriminant (Derived_Base))
+ and then
+ (not Is_Private_Type (Derived_Base)
+ or else Is_Completely_Hidden
+ (First_Stored_Discriminant (Derived_Base))
+ or else Is_Generic_Type (Derived_Base))
+ then
+ D := First_Discriminant (Derived_Base);
+ while Present (D) loop
+ Append_Elmt (New_Reference_To (D, Loc), Discs);
+ Next_Discriminant (D);
+ end loop;
+ end if;
+
+ -- Finally, inherit non-discriminant components unless they are not
+ -- visible because defined or inherited from the full view of the
+ -- parent. Don't inherit the _parent field of the parent type.
+
+ Component := First_Entity (Parent_Base);
+ while Present (Component) loop
+
+ -- Ada 2005 (AI-251): Do not inherit components associated with
+ -- secondary tags of the parent.
+
+ if Ekind (Component) = E_Component
+ and then Present (Related_Type (Component))
+ then
+ null;
+
+ elsif Ekind (Component) /= E_Component
+ or else Chars (Component) = Name_uParent
+ then
+ null;
+
+ -- If the derived type is within the parent type's declarative
+ -- region, then the components can still be inherited even though
+ -- they aren't visible at this point. This can occur for cases
+ -- such as within public child units where the components must
+ -- become visible upon entering the child unit's private part.
+
+ elsif not Is_Visible_Component (Component)
+ and then not In_Open_Scopes (Scope (Parent_Base))
+ then
+ null;
+
+ elsif Ekind_In (Derived_Base, E_Private_Type,
+ 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_Constant_Bound --
+ -----------------------
+
+ function Is_Constant_Bound (Exp : Node_Id) return Boolean is
+ begin
+ if Compile_Time_Known_Value (Exp) then
+ return True;
+
+ elsif Is_Entity_Name (Exp)
+ and then Present (Entity (Exp))
+ then
+ return Is_Constant_Object (Entity (Exp))
+ or else Ekind (Entity (Exp)) = E_Enumeration_Literal;
+
+ elsif Nkind (Exp) in N_Binary_Op then
+ return Is_Constant_Bound (Left_Opnd (Exp))
+ and then Is_Constant_Bound (Right_Opnd (Exp))
+ and then Scope (Entity (Exp)) = Standard_Standard;
+
+ else
+ return False;
+ end if;
+ end Is_Constant_Bound;
+
+ -----------------------
+ -- Is_Null_Extension --
+ -----------------------
+
+ function Is_Null_Extension (T : Entity_Id) return Boolean is
+ Type_Decl : constant Node_Id := Parent (Base_Type (T));
+ Comp_List : Node_Id;
+ Comp : Node_Id;
+
+ begin
+ if Nkind (Type_Decl) /= N_Full_Type_Declaration
+ or else not Is_Tagged_Type (T)
+ or else Nkind (Type_Definition (Type_Decl)) /=
+ N_Derived_Type_Definition
+ or else No (Record_Extension_Part (Type_Definition (Type_Decl)))
+ then
+ return False;
+ end if;
+
+ Comp_List :=
+ Component_List (Record_Extension_Part (Type_Definition (Type_Decl)));
+
+ if Present (Discriminant_Specifications (Type_Decl)) then
+ return False;
+
+ elsif Present (Comp_List)
+ and then Is_Non_Empty_List (Component_Items (Comp_List))
+ then
+ Comp := First (Component_Items (Comp_List));
+
+ -- Only user-defined components are relevant. The component list
+ -- may also contain a parent component and internal components
+ -- corresponding to secondary tags, but these do not determine
+ -- whether this is a null extension.
+
+ while Present (Comp) loop
+ if Comes_From_Source (Comp) then
+ return False;
+ end if;
+
+ Next (Comp);
+ end loop;
+
+ return True;
+ else
+ return True;
+ end if;
+ end Is_Null_Extension;
+
+ ------------------------------
+ -- Is_Valid_Constraint_Kind --
+ ------------------------------
+
+ function Is_Valid_Constraint_Kind
+ (T_Kind : Type_Kind;
+ Constraint_Kind : Node_Kind) return Boolean
+ is
+ begin
+ case T_Kind is
+ when Enumeration_Kind |
+ Integer_Kind =>
+ return Constraint_Kind = N_Range_Constraint;
+
+ when Decimal_Fixed_Point_Kind =>
+ return Nkind_In (Constraint_Kind, N_Digits_Constraint,
+ N_Range_Constraint);
+
+ when Ordinary_Fixed_Point_Kind =>
+ return Nkind_In (Constraint_Kind, N_Delta_Constraint,
+ N_Range_Constraint);
+
+ when Float_Kind =>
+ return Nkind_In (Constraint_Kind, N_Digits_Constraint,
+ 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;
+ N : Node_Id := Empty) return Boolean
+ is
+ Original_Comp : Entity_Id := Empty;
+ Original_Scope : Entity_Id;
+ Type_Scope : Entity_Id;
+
+ function Is_Local_Type (Typ : Entity_Id) return Boolean;
+ -- Check whether parent type of inherited component is declared locally,
+ -- possibly within a nested package or instance. The current scope is
+ -- the derived record itself.
+
+ -------------------
+ -- Is_Local_Type --
+ -------------------
+
+ function Is_Local_Type (Typ : Entity_Id) return Boolean is
+ Scop : Entity_Id;
+
+ begin
+ Scop := Scope (Typ);
+ while Present (Scop)
+ and then Scop /= Standard_Standard
+ loop
+ if Scop = Scope (Current_Scope) then
+ return True;
+ end if;
+
+ Scop := Scope (Scop);
+ end loop;
+
+ return False;
+ end Is_Local_Type;
+
+ -- Start of processing for Is_Visible_Component
+
+ begin
+ if Ekind_In (C, E_Component, 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;
+
+ -- Discriminants are visible unless the (private) type has unknown
+ -- discriminants. If the discriminant reference is inserted for a
+ -- discriminant check on a full view it is also visible.
+
+ elsif Ekind (Original_Comp) = E_Discriminant
+ and then
+ (not Has_Unknown_Discriminants (Original_Scope)
+ or else (Present (N)
+ and then Nkind (N) = N_Selected_Component
+ and then Nkind (Prefix (N)) = N_Type_Conversion
+ and then not Comes_From_Source (Prefix (N))))
+ then
+ return True;
+
+ -- In the body of an instantiation, no need to check for the visibility
+ -- of a component.
+
+ elsif In_Instance_Body 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 view 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 In_Open_Scopes (Scope (Original_Scope))
+ 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;
+ 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
+ if Present (Class_Wide_Type (T)) then
+
+ -- The class-wide type is a partially decorated entity created for a
+ -- unanalyzed tagged type referenced through a limited with clause.
+ -- When the tagged type is analyzed, its class-wide type needs to be
+ -- redecorated. Note that we reuse the entity created by Decorate_
+ -- Tagged_Type in order to preserve all links.
+
+ if Materialize_Entity (Class_Wide_Type (T)) then
+ CW_Type := Class_Wide_Type (T);
+ Set_Materialize_Entity (CW_Type, False);
+
+ -- The class wide type can have been defined by the partial view, in
+ -- which case everything is already done.
+
+ else
+ return;
+ end if;
+
+ -- Default case, we need to create a new class-wide type
+
+ else
+ CW_Type :=
+ New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
+ end if;
+
+ -- 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);
+
+ -- Ensure we have a new freeze node for the class-wide type. The partial
+ -- view may have freeze action of its own, requiring a proper freeze
+ -- node, and the same freeze node cannot be shared between the two
+ -- types.
+
+ Set_Has_Delayed_Freeze (CW_Type);
+ Set_Freeze_Node (CW_Type, Empty);
+
+ -- 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_Direct_Primitive_Operations (CW_Type, New_Elmt_List);
+ Set_Is_Abstract_Type (CW_Type, False);
+ Set_Is_Constrained (CW_Type, False);
+ Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
+
+ 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;
+ In_Iter_Schm : Boolean := False)
+ 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);
+
+ -- For universal bounds, choose the specific predefined type
+
+ if T = Universal_Integer then
+ T := Standard_Integer;
+
+ elsif T = Any_Character then
+ Ambiguous_Character (Low_Bound (I));
+
+ T := Standard_Character;
+ end if;
+
+ -- The node may be overloaded because some user-defined operators
+ -- are available, but if a universal interpretation exists it is
+ -- also the selected one.
+
+ elsif Universal_Interpretation (I) = Universal_Integer then
+ T := Standard_Integer;
+
+ 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, In_Iter_Schm => In_Iter_Schm);
+
+ 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)), In_Iter_Schm => In_Iter_Schm);
+
+ 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));
+ Analyze_And_Resolve (I);
+ T := Etype (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;
+
+ if not Non_Binary_Modulus (T)
+ and then Esize (T) = RM_Size (T)
+ then
+ Set_Is_Known_Valid (T);
+ end if;
+ end Set_Modular_Size;
+
+ -- Start of processing for Modular_Type_Declaration
+
+ begin
+ -- If the mod expression is (exactly) 2 * literal, where literal is
+ -- 64 or less,then almost certainly the * was meant to be **. Warn!
+
+ if Warn_On_Suspicious_Modulus_Value
+ and then Nkind (Mod_Expr) = N_Op_Multiply
+ and then Nkind (Left_Opnd (Mod_Expr)) = N_Integer_Literal
+ and then Intval (Left_Opnd (Mod_Expr)) = Uint_2
+ and then Nkind (Right_Opnd (Mod_Expr)) = N_Integer_Literal
+ and then Intval (Right_Opnd (Mod_Expr)) <= Uint_64
+ then
+ Error_Msg_N
+ ("suspicious MOD value, was '*'* intended'??M?", Mod_Expr);
+ end if;
+
+ -- Proceed with analysis of mod expression
+
+ 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
+ Check_SPARK_Restriction ("modulus should be a power of 2", T);
+ 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_F
+ ("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_F ("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;
+
+ -------------------------
+ -- OK_For_Limited_Init --
+ -------------------------
+
+ -- ???Check all calls of this, and compare the conditions under which it's
+ -- called.
+
+ function OK_For_Limited_Init
+ (Typ : Entity_Id;
+ Exp : Node_Id) return Boolean
+ is
+ begin
+ return Is_CPP_Constructor_Call (Exp)
+ or else (Ada_Version >= Ada_2005
+ and then not Debug_Flag_Dot_L
+ and then OK_For_Limited_Init_In_05 (Typ, Exp));
+ end OK_For_Limited_Init;
+
+ -------------------------------
+ -- OK_For_Limited_Init_In_05 --
+ -------------------------------
+
+ function OK_For_Limited_Init_In_05
+ (Typ : Entity_Id;
+ Exp : Node_Id) return Boolean
+ is
+ begin
+ -- An object of a limited interface type can be initialized with any
+ -- expression of a nonlimited descendant type.
+
+ if Is_Class_Wide_Type (Typ)
+ and then Is_Limited_Interface (Typ)
+ and then not Is_Limited_Type (Etype (Exp))
+ then
+ return True;
+ end if;
+
+ -- Ada 2005 (AI-287, AI-318): Relax the strictness of the front end in
+ -- case of limited aggregates (including extension aggregates), and
+ -- function calls. The function call may have been given in prefixed
+ -- notation, in which case the original node is an indexed component.
+ -- If the function is parameterless, the original node was an explicit
+ -- dereference. The function may also be parameterless, in which case
+ -- the source node is just an identifier.
+
+ case Nkind (Original_Node (Exp)) is
+ when N_Aggregate | N_Extension_Aggregate | N_Function_Call | N_Op =>
+ return True;
+
+ when N_Identifier =>
+ return Present (Entity (Original_Node (Exp)))
+ and then Ekind (Entity (Original_Node (Exp))) = E_Function;
+
+ when N_Qualified_Expression =>
+ return
+ OK_For_Limited_Init_In_05
+ (Typ, Expression (Original_Node (Exp)));
+
+ -- Ada 2005 (AI-251): If a class-wide interface object is initialized
+ -- with a function call, the expander has rewritten the call into an
+ -- N_Type_Conversion node to force displacement of the pointer to
+ -- reference the component containing the secondary dispatch table.
+ -- Otherwise a type conversion is not a legal context.
+ -- A return statement for a build-in-place function returning a
+ -- synchronized type also introduces an unchecked conversion.
+
+ when N_Type_Conversion |
+ N_Unchecked_Type_Conversion =>
+ return not Comes_From_Source (Exp)
+ and then
+ OK_For_Limited_Init_In_05
+ (Typ, Expression (Original_Node (Exp)));
+
+ when N_Indexed_Component |
+ N_Selected_Component |
+ N_Explicit_Dereference =>
+ return Nkind (Exp) = N_Function_Call;
+
+ -- A use of 'Input is a function call, hence allowed. Normally the
+ -- attribute will be changed to a call, but the attribute by itself
+ -- can occur with -gnatc.
+
+ when N_Attribute_Reference =>
+ return Attribute_Name (Original_Node (Exp)) = Name_Input;
+
+ -- For a case expression, all dependent expressions must be legal
+
+ when N_Case_Expression =>
+ declare
+ Alt : Node_Id;
+
+ begin
+ Alt := First (Alternatives (Original_Node (Exp)));
+ while Present (Alt) loop
+ if not OK_For_Limited_Init_In_05 (Typ, Expression (Alt)) then
+ return False;
+ end if;
+
+ Next (Alt);
+ end loop;
+
+ return True;
+ end;
+
+ -- For an if expression, all dependent expressions must be legal
+
+ when N_If_Expression =>
+ declare
+ Then_Expr : constant Node_Id :=
+ Next (First (Expressions (Original_Node (Exp))));
+ Else_Expr : constant Node_Id := Next (Then_Expr);
+ begin
+ return OK_For_Limited_Init_In_05 (Typ, Then_Expr)
+ and then
+ OK_For_Limited_Init_In_05 (Typ, Else_Expr);
+ end;
+
+ when others =>
+ return False;
+ end case;
+ end OK_For_Limited_Init_In_05;
+
+ -------------------------------------------
+ -- Ordinary_Fixed_Point_Type_Declaration --
+ -------------------------------------------
+
+ procedure Ordinary_Fixed_Point_Type_Declaration
+ (T : Entity_Id;
+ Def : Node_Id)
+ is
+ Loc : constant Source_Ptr := Sloc (Def);
+ Delta_Expr : constant Node_Id := Delta_Expression (Def);
+ RRS : constant Node_Id := Real_Range_Specification (Def);
+ Implicit_Base : Entity_Id;
+ Delta_Val : Ureal;
+ Small_Val : Ureal;
+ Low_Val : Ureal;
+ High_Val : Ureal;
+
+ begin
+ Check_Restriction (No_Fixed_Point, Def);
+
+ -- Create implicit base type
+
+ Implicit_Base :=
+ Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
+ Set_Etype (Implicit_Base, Implicit_Base);
+
+ -- Analyze and process delta expression
+
+ Analyze_And_Resolve (Delta_Expr, Any_Real);
+
+ Check_Delta_Expression (Delta_Expr);
+ Delta_Val := Expr_Value_R (Delta_Expr);
+
+ Set_Delta_Value (Implicit_Base, Delta_Val);
+
+ -- Compute default small from given delta, which is the largest power
+ -- of two that does not exceed the given delta value.
+
+ declare
+ Tmp : Ureal;
+ Scale : Int;
+
+ begin
+ Tmp := Ureal_1;
+ Scale := 0;
+
+ if Delta_Val < Ureal_1 then
+ while Delta_Val < Tmp loop
+ Tmp := Tmp / Ureal_2;
+ Scale := Scale + 1;
+ end loop;
+
+ else
+ loop
+ Tmp := Tmp * Ureal_2;
+ exit when Tmp > Delta_Val;
+ Scale := Scale - 1;
+ end loop;
+ end if;
+
+ Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
+ end;
+
+ Set_Small_Value (Implicit_Base, Small_Val);
+
+ -- If no range was given, set a dummy range
+
+ if RRS <= Empty_Or_Error then
+ Low_Val := -Small_Val;
+ High_Val := Small_Val;
+
+ -- Otherwise analyze and process given range
+
+ else
+ declare
+ Low : constant Node_Id := Low_Bound (RRS);
+ High : constant Node_Id := High_Bound (RRS);
+
+ begin
+ Analyze_And_Resolve (Low, Any_Real);
+ Analyze_And_Resolve (High, Any_Real);
+ Check_Real_Bound (Low);
+ Check_Real_Bound (High);
+
+ -- Obtain and set the range
+
+ Low_Val := Expr_Value_R (Low);
+ High_Val := Expr_Value_R (High);
+
+ if Low_Val > High_Val then
+ Error_Msg_NE ("??fixed point type& has null range", Def, T);
+ end if;
+ end;
+ end if;
+
+ -- The range for both the implicit base and the declared first subtype
+ -- cannot be set yet, so we use the special routine Set_Fixed_Range to
+ -- set a temporary range in place. Note that the bounds of the base
+ -- type will be widened to be symmetrical and to fill the available
+ -- bits when the type is frozen.
+
+ -- We could do this with all discrete types, and probably should, but
+ -- we absolutely have to do it for fixed-point, since the end-points
+ -- of the range and the size are determined by the small value, which
+ -- could be reset before the freeze point.
+
+ Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
+ Set_Fixed_Range (T, Loc, Low_Val, High_Val);
+
+ -- 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.
+ -- On entry, the current scope is the composite type.
+
+ -- The discriminants are initially entered into the scope of the type
+ -- via Enter_Name with the default Ekind of E_Void to prevent premature
+ -- use, as explained at the end of this procedure.
+
+ Discr := First (Discriminant_Specifications (N));
+ while Present (Discr) loop
+ Enter_Name (Defining_Identifier (Discr));
+
+ -- For navigation purposes we add a reference to the discriminant
+ -- in the entity for the type. If the current declaration is a
+ -- completion, place references on the partial view. Otherwise the
+ -- type is the current scope.
+
+ if Present (Prev) then
+
+ -- The references go on the partial view, if present. If the
+ -- partial view has discriminants, the references have been
+ -- generated already.
+
+ if not Has_Discriminants (Prev) then
+ Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
+ end if;
+ else
+ Generate_Reference
+ (Current_Scope, Defining_Identifier (Discr), 'd');
+ end if;
+
+ if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
+ Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr));
+
+ -- Ada 2005 (AI-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);
+ 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_2005 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
+ Preanalyze_Spec_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));
+
+ -- Flag an error for a tagged type with defaulted discriminants,
+ -- excluding limited tagged types when compiling for Ada 2012
+ -- (see AI05-0214).
+
+ elsif Is_Tagged_Type (Current_Scope)
+ and then (not Is_Limited_Type (Current_Scope)
+ or else Ada_Version < Ada_2012)
+ and then Comes_From_Source (N)
+ then
+ -- Note: see similar test in Check_Or_Process_Discriminants, to
+ -- handle the (illegal) case of the completion of an untagged
+ -- view with discriminants with defaults by a tagged full view.
+ -- We skip the check if Discr does not come from source, to
+ -- account for the case of an untagged derived type providing
+ -- defaults for a renamed discriminant from a private untagged
+ -- ancestor with a tagged full view (ACATS B460006).
+
+ if Ada_Version >= Ada_2012 then
+ Error_Msg_N
+ ("discriminants of nonlimited tagged type cannot have"
+ & " defaults",
+ Expression (Discr));
+ else
+ Error_Msg_N
+ ("discriminants of tagged type cannot have defaults",
+ Expression (Discr));
+ end if;
+
+ else
+ Default_Present := True;
+ Append_Elmt (Expression (Discr), Elist);
+
+ -- Tag the defining identifiers for the discriminants with
+ -- their corresponding default expressions from the tree.
+
+ Set_Discriminant_Default_Value
+ (Defining_Identifier (Discr), Expression (Discr));
+ end if;
+
+ else
+ Default_Not_Present := True;
+ end if;
+
+ -- Ada 2005 (AI-231): Create an Itype that is a duplicate of
+ -- Discr_Type but with the null-exclusion attribute
+
+ if Ada_Version >= Ada_2005 then
+
+ -- Ada 2005 (AI-231): Static checks
+
+ if Can_Never_Be_Null (Discr_Type) then
+ Null_Exclusion_Static_Checks (Discr);
+
+ elsif Is_Access_Type (Discr_Type)
+ and then Null_Exclusion_Present (Discr)
+
+ -- No need to check itypes because in their case this check
+ -- was done at their point of creation
+
+ and then not Is_Itype (Discr_Type)
+ then
+ if Can_Never_Be_Null (Discr_Type) then
+ Error_Msg_NE
+ ("`NOT NULL` not allowed (& already excludes null)",
+ Discr,
+ Discr_Type);
+ end if;
+
+ Set_Etype (Defining_Identifier (Discr),
+ Create_Null_Excluding_Itype
+ (T => Discr_Type,
+ Related_Nod => Discr));
+
+ -- Check for improper null exclusion if the type is otherwise
+ -- legal for a discriminant.
+
+ elsif Null_Exclusion_Present (Discr)
+ and then Is_Discrete_Type (Discr_Type)
+ then
+ Error_Msg_N
+ ("null exclusion can only apply to an access type", Discr);
+ end if;
+
+ -- Ada 2005 (AI-402): access discriminants of nonlimited types
+ -- can't have defaults. Synchronized types, or types that are
+ -- explicitly limited are fine, but special tests apply to derived
+ -- types in generics: in a generic body we have to assume the
+ -- worst, and therefore defaults are not allowed if the parent is
+ -- a generic formal private type (see ACATS B370001).
+
+ if Is_Access_Type (Discr_Type) and then Default_Present then
+ if Ekind (Discr_Type) /= E_Anonymous_Access_Type
+ or else Is_Limited_Record (Current_Scope)
+ or else Is_Concurrent_Type (Current_Scope)
+ or else Is_Concurrent_Record_Type (Current_Scope)
+ or else Ekind (Current_Scope) = E_Limited_Private_Type
+ then
+ if not Is_Derived_Type (Current_Scope)
+ or else not Is_Generic_Type (Etype (Current_Scope))
+ or else not In_Package_Body (Scope (Etype (Current_Scope)))
+ or else Limited_Present
+ (Type_Definition (Parent (Current_Scope)))
+ then
+ null;
+
+ else
+ Error_Msg_N ("access discriminants of nonlimited types",
+ Expression (Discr));
+ Error_Msg_N ("\cannot have defaults", Expression (Discr));
+ end if;
+
+ elsif Present (Expression (Discr)) then
+ Error_Msg_N
+ ("(Ada 2005) access discriminants of nonlimited types",
+ Expression (Discr));
+ Error_Msg_N ("\cannot have defaults", Expression (Discr));
+ end if;
+ end if;
+ end if;
+
+ Next (Discr);
+ end loop;
+
+ -- An element list consisting of the default expressions of the
+ -- discriminants is constructed in the above loop and used to set
+ -- the Discriminant_Constraint attribute for the type. If an object
+ -- is declared of this (record or task) type without any explicit
+ -- discriminant constraint given, this element list will form the
+ -- actual parameters for the corresponding initialization procedure
+ -- for the type.
+
+ Set_Discriminant_Constraint (Current_Scope, Elist);
+ Set_Stored_Constraint (Current_Scope, No_Elist);
+
+ -- Default expressions must be provided either for all or for none
+ -- of the discriminants of a discriminant part. (RM 3.7.1)
+
+ if Default_Present and then Default_Not_Present then
+ Error_Msg_N
+ ("incomplete specification of defaults for discriminants", N);
+ end if;
+
+ -- The use of the name of a discriminant is not allowed in default
+ -- expressions of a discriminant part if the specification of the
+ -- discriminant is itself given in the discriminant part. (RM 3.7.1)
+
+ -- To detect this, the discriminant names are entered initially with an
+ -- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
+ -- attempt to use a void entity (for example in an expression that is
+ -- type-checked) produces the error message: premature usage. Now after
+ -- completing the semantic analysis of the discriminant part, we can set
+ -- the Ekind of all the discriminants appropriately.
+
+ Discr := First (Discriminant_Specifications (N));
+ Discr_Number := Uint_1;
+ while Present (Discr) loop
+ Id := Defining_Identifier (Discr);
+ Set_Ekind (Id, E_Discriminant);
+ Init_Component_Location (Id);
+ Init_Esize (Id);
+ Set_Discriminant_Number (Id, Discr_Number);
+
+ -- Make sure this is always set, even in illegal programs
+
+ Set_Corresponding_Discriminant (Id, Empty);
+
+ -- Initialize the Original_Record_Component to the entity itself.
+ -- Inherit_Components will propagate the right value to
+ -- discriminants in derived record types.
+
+ Set_Original_Record_Component (Id, Id);
+
+ -- Create the discriminal for the discriminant
+
+ Build_Discriminal (Id);
+
+ Next (Discr);
+ Discr_Number := Discr_Number + 1;
+ end loop;
+
+ Set_Has_Discriminants (Current_Scope);
+ end Process_Discriminants;
+
+ -----------------------
+ -- Process_Full_View --
+ -----------------------
+
+ procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
+ Priv_Parent : Entity_Id;
+ Full_Parent : Entity_Id;
+ Full_Indic : Node_Id;
+
+ procedure Collect_Implemented_Interfaces
+ (Typ : Entity_Id;
+ Ifaces : Elist_Id);
+ -- Ada 2005: Gather all the interfaces that Typ directly or
+ -- inherently implements. Duplicate entries are not added to
+ -- the list Ifaces.
+
+ ------------------------------------
+ -- Collect_Implemented_Interfaces --
+ ------------------------------------
+
+ procedure Collect_Implemented_Interfaces
+ (Typ : Entity_Id;
+ Ifaces : Elist_Id)
+ is
+ Iface : Entity_Id;
+ Iface_Elmt : Elmt_Id;
+
+ begin
+ -- Abstract interfaces are only associated with tagged record types
+
+ if not Is_Tagged_Type (Typ)
+ or else not Is_Record_Type (Typ)
+ then
+ return;
+ end if;
+
+ -- Recursively climb to the ancestors
+
+ if Etype (Typ) /= Typ
+
+ -- Protect the frontend against wrong cyclic declarations like:
+
+ -- type B is new A with private;
+ -- type C is new A with private;
+ -- private
+ -- type B is new C with null record;
+ -- type C is new B with null record;
+
+ and then Etype (Typ) /= Priv_T
+ and then Etype (Typ) /= Full_T
+ then
+ -- Keep separate the management of private type declarations
+
+ if Ekind (Typ) = E_Record_Type_With_Private then
+
+ -- Handle the following erroneous case:
+ -- type Private_Type is tagged private;
+ -- private
+ -- type Private_Type is new Type_Implementing_Iface;
+
+ if Present (Full_View (Typ))
+ and then Etype (Typ) /= Full_View (Typ)
+ then
+ if Is_Interface (Etype (Typ)) then
+ Append_Unique_Elmt (Etype (Typ), Ifaces);
+ end if;
+
+ Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
+ end if;
+
+ -- Non-private types
+
+ else
+ if Is_Interface (Etype (Typ)) then
+ Append_Unique_Elmt (Etype (Typ), Ifaces);
+ end if;
+
+ Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
+ end if;
+ end if;
+
+ -- Handle entities in the list of abstract interfaces
+
+ if Present (Interfaces (Typ)) then
+ Iface_Elmt := First_Elmt (Interfaces (Typ));
+ while Present (Iface_Elmt) loop
+ Iface := Node (Iface_Elmt);
+
+ pragma Assert (Is_Interface (Iface));
+
+ if not Contain_Interface (Iface, Ifaces) then
+ Append_Elmt (Iface, Ifaces);
+ Collect_Implemented_Interfaces (Iface, Ifaces);
+ end if;
+
+ Next_Elmt (Iface_Elmt);
+ end loop;
+ end if;
+ end Collect_Implemented_Interfaces;
+
+ -- Start of processing for Process_Full_View
+
+ begin
+ -- First some sanity checks that must be done after semantic
+ -- decoration of the full view and thus cannot be placed with other
+ -- similar checks in Find_Type_Name
+
+ if not Is_Limited_Type (Priv_T)
+ and then (Is_Limited_Type (Full_T)
+ or else Is_Limited_Composite (Full_T))
+ then
+ if In_Instance then
+ null;
+ else
+ Error_Msg_N
+ ("completion of nonlimited type cannot be limited", Full_T);
+ Explain_Limited_Type (Full_T, Full_T);
+ end if;
+
+ elsif Is_Abstract_Type (Full_T)
+ and then not Is_Abstract_Type (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
+ -- If pragma CPP_Class was applied to the private declaration
+ -- propagate the limitedness to the full-view
+
+ if Is_CPP_Class (Priv_T) then
+ Set_Is_Limited_Record (Full_T);
+
+ -- GNAT allow its own definition of Limited_Controlled to disobey
+ -- this rule in order in ease the implementation. This test is safe
+ -- because Root_Controlled is defined in a child of System that
+ -- normal programs are not supposed to use.
+
+ elsif Is_RTE (Etype (Full_T), 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;
+
+ -- Check that ancestor interfaces of private and full views are
+ -- consistent. We omit this check for synchronized types because
+ -- they are performed on the corresponding record type when frozen.
+
+ if Ada_Version >= Ada_2005
+ and then Is_Tagged_Type (Priv_T)
+ and then Is_Tagged_Type (Full_T)
+ and then not Is_Concurrent_Type (Full_T)
+ then
+ declare
+ Iface : Entity_Id;
+ Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
+ Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
+
+ begin
+ Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
+ Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
+
+ -- Ada 2005 (AI-251): The partial view shall be a descendant of
+ -- an interface type if and only if the full type is descendant
+ -- of the interface type (AARM 7.3 (7.3/2)).
+
+ Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
+
+ if Present (Iface) then
+ Error_Msg_NE
+ ("interface & not implemented by full type " &
+ "(RM-2005 7.3 (7.3/2))", Priv_T, Iface);
+ end if;
+
+ Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
+
+ if Present (Iface) then
+ Error_Msg_NE
+ ("interface & not implemented by partial view " &
+ "(RM-2005 7.3 (7.3/2))", Full_T, Iface);
+ end if;
+ end;
+ end if;
+
+ if Is_Tagged_Type (Priv_T)
+ and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
+ and then Is_Derived_Type (Full_T)
+ then
+ Priv_Parent := Etype (Priv_T);
+
+ -- The full view of a private extension may have been transformed
+ -- into an unconstrained derived type declaration and a subtype
+ -- declaration (see build_derived_record_type for details).
+
+ if Nkind (N) = N_Subtype_Declaration then
+ Full_Indic := Subtype_Indication (N);
+ Full_Parent := Etype (Base_Type (Full_T));
+ else
+ Full_Indic := Subtype_Indication (Type_Definition (N));
+ Full_Parent := Etype (Full_T);
+ end if;
+
+ -- Check that the parent type of the full type is a descendant of
+ -- the ancestor subtype given in the private extension. If either
+ -- entity has an Etype equal to Any_Type then we had some previous
+ -- error situation [7.3(8)].
+
+ if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
+ return;
+
+ -- Ada 2005 (AI-251): Interfaces in the full-typ can be given in
+ -- any order. Therefore we don't have to check that its parent must
+ -- be a descendant of the parent of the private type declaration.
+
+ elsif Is_Interface (Priv_Parent)
+ and then Is_Interface (Full_Parent)
+ then
+ null;
+
+ -- Ada 2005 (AI-251): If the parent of the private type declaration
+ -- is an interface there is no need to check that it is an ancestor
+ -- of the associated full type declaration. The required tests for
+ -- this case are performed by Build_Derived_Record_Type.
+
+ elsif not Is_Interface (Base_Type (Priv_Parent))
+ and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
+ then
+ Error_Msg_N
+ ("parent of full type must descend from parent"
+ & " of private extension", Full_Indic);
+
+ -- First check a formal restriction, and then proceed with checking
+ -- Ada rules. Since the formal restriction is not a serious error, we
+ -- don't prevent further error detection for this check, hence the
+ -- ELSE.
+
+ else
+
+ -- In formal mode, when completing a private extension the type
+ -- named in the private part must be exactly the same as that
+ -- named in the visible part.
+
+ if Priv_Parent /= Full_Parent then
+ Error_Msg_Name_1 := Chars (Priv_Parent);
+ Check_SPARK_Restriction ("% expected", Full_Indic);
+ end if;
+
+ -- 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.
+
+ if No (Discriminant_Specifications (Parent (Priv_T)))
+ and then not Has_Unknown_Discriminants (Priv_T)
+ and then Has_Discriminants (Base_Type (Priv_Parent))
+ then
+ declare
+ Priv_Indic : constant Node_Id :=
+ Subtype_Indication (Parent (Priv_T));
+
+ Priv_Constr : constant Boolean :=
+ Is_Constrained (Priv_Parent)
+ or else
+ Nkind (Priv_Indic) = N_Subtype_Indication
+ or else
+ Is_Constrained (Entity (Priv_Indic));
+
+ Full_Constr : constant Boolean :=
+ Is_Constrained (Full_Parent)
+ or else
+ Nkind (Full_Indic) = N_Subtype_Indication
+ or else
+ Is_Constrained (Entity (Full_Indic));
+
+ Priv_Discr : Entity_Id;
+ Full_Discr : Entity_Id;
+
+ begin
+ Priv_Discr := First_Discriminant (Priv_Parent);
+ Full_Discr := First_Discriminant (Full_Parent);
+ while Present (Priv_Discr) and then Present (Full_Discr) loop
+ if Original_Record_Component (Priv_Discr) =
+ Original_Record_Component (Full_Discr)
+ or else
+ Corresponding_Discriminant (Priv_Discr) =
+ Corresponding_Discriminant (Full_Discr)
+ then
+ null;
+ else
+ exit;
+ end if;
+
+ Next_Discriminant (Priv_Discr);
+ Next_Discriminant (Full_Discr);
+ end loop;
+
+ if Present (Priv_Discr) or else Present (Full_Discr) then
+ Error_Msg_N
+ ("full view must inherit discriminants of the parent"
+ & " type used in the private extension", Full_Indic);
+
+ elsif Priv_Constr and then not Full_Constr then
+ Error_Msg_N
+ ("parent subtype of full type must be constrained",
+ Full_Indic);
+
+ elsif Full_Constr and then not Priv_Constr then
+ Error_Msg_N
+ ("parent subtype of full type must be unconstrained",
+ Full_Indic);
+ end if;
+ end;
+
+ -- Check the rules of 7.3(12): if a partial view has neither
+ -- known or unknown discriminants, then the full type
+ -- declaration shall define a definite subtype.
+
+ elsif not Has_Unknown_Discriminants (Priv_T)
+ and then not Has_Discriminants (Priv_T)
+ and then not Is_Constrained (Full_T)
+ then
+ Error_Msg_N
+ ("full view must define a constrained type if partial view"
+ & " has no discriminants", Full_T);
+ end if;
+
+ -- ??????? Do we implement the following properly ?????
+ -- If the ancestor subtype of a private extension has constrained
+ -- discriminants, then the parent subtype of the full view shall
+ -- impose a statically matching constraint on those discriminants
+ -- [7.3(13)].
+ end if;
+
+ else
+ -- For untagged types, verify that a type without discriminants
+ -- is not completed with an unconstrained type.
+
+ if not Is_Indefinite_Subtype (Priv_T)
+ and then Is_Indefinite_Subtype (Full_T)
+ then
+ Error_Msg_N ("full view of type must be definite subtype", Full_T);
+ end if;
+ end if;
+
+ -- AI-419: verify that the use of "limited" is consistent
+
+ declare
+ Orig_Decl : constant Node_Id := Original_Node (N);
+
+ begin
+ if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
+ and then not Limited_Present (Parent (Priv_T))
+ and then not Synchronized_Present (Parent (Priv_T))
+ and then Nkind (Orig_Decl) = N_Full_Type_Declaration
+ and then Nkind
+ (Type_Definition (Orig_Decl)) = N_Derived_Type_Definition
+ and then Limited_Present (Type_Definition (Orig_Decl))
+ then
+ Error_Msg_N
+ ("full view of non-limited extension cannot be limited", N);
+ end if;
+ end;
+
+ -- Ada 2005 (AI-443): A synchronized private extension must be
+ -- completed by a task or protected type.
+
+ if Ada_Version >= Ada_2005
+ and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
+ and then Synchronized_Present (Parent (Priv_T))
+ and then not Is_Concurrent_Type (Full_T)
+ then
+ Error_Msg_N ("full view of synchronized extension must " &
+ "be synchronized type", N);
+ end if;
+
+ -- Ada 2005 AI-363: if the full view has discriminants with
+ -- defaults, it is illegal to declare constrained access subtypes
+ -- whose designated type is the current type. This allows objects
+ -- of the type that are declared in the heap to be unconstrained.
+
+ if not Has_Unknown_Discriminants (Priv_T)
+ and then not Has_Discriminants (Priv_T)
+ and then Has_Discriminants (Full_T)
+ and then
+ Present (Discriminant_Default_Value (First_Discriminant (Full_T)))
+ then
+ Set_Has_Constrained_Partial_View (Full_T);
+ Set_Has_Constrained_Partial_View (Priv_T);
+ end if;
+
+ -- Create a full declaration for all its subtypes recorded in
+ -- Private_Dependents and swap them similarly to the base type. These
+ -- are subtypes that have been define before the full declaration of
+ -- the private type. We also swap the entry in Private_Dependents list
+ -- so we can properly restore the private view on exit from the scope.
+
+ declare
+ Priv_Elmt : Elmt_Id;
+ Priv : Entity_Id;
+ Full : Entity_Id;
+
+ begin
+ Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
+ while Present (Priv_Elmt) loop
+ Priv := Node (Priv_Elmt);
+
+ if Ekind_In (Priv, E_Private_Subtype,
+ E_Limited_Private_Subtype,
+ 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
+ Disp_Typ : Entity_Id;
+ Full_List : Elist_Id;
+ Prim : Entity_Id;
+ Prim_Elmt : Elmt_Id;
+ Priv_List : Elist_Id;
+
+ function Contains
+ (E : Entity_Id;
+ L : Elist_Id) return Boolean;
+ -- Determine whether list L contains element E
+
+ --------------
+ -- Contains --
+ --------------
+
+ function Contains
+ (E : Entity_Id;
+ L : Elist_Id) return Boolean
+ is
+ List_Elmt : Elmt_Id;
+
+ begin
+ List_Elmt := First_Elmt (L);
+ while Present (List_Elmt) loop
+ if Node (List_Elmt) = E then
+ return True;
+ end if;
+
+ Next_Elmt (List_Elmt);
+ end loop;
+
+ return False;
+ end Contains;
+
+ -- Start of processing
+
+ begin
+ if Is_Tagged_Type (Priv_T) then
+ Priv_List := Primitive_Operations (Priv_T);
+ Prim_Elmt := First_Elmt (Priv_List);
+
+ -- In the case of a concurrent type completing a private tagged
+ -- type, primitives may have been declared in between the two
+ -- views. These subprograms need to be wrapped the same way
+ -- entries and protected procedures are handled because they
+ -- cannot be directly shared by the two views.
+
+ if Is_Concurrent_Type (Full_T) then
+ declare
+ Conc_Typ : constant Entity_Id :=
+ Corresponding_Record_Type (Full_T);
+ Curr_Nod : Node_Id := Parent (Conc_Typ);
+ Wrap_Spec : Node_Id;
+
+ begin
+ while Present (Prim_Elmt) loop
+ Prim := Node (Prim_Elmt);
+
+ if Comes_From_Source (Prim)
+ and then not Is_Abstract_Subprogram (Prim)
+ then
+ Wrap_Spec :=
+ Make_Subprogram_Declaration (Sloc (Prim),
+ Specification =>
+ Build_Wrapper_Spec
+ (Subp_Id => Prim,
+ Obj_Typ => Conc_Typ,
+ Formals =>
+ Parameter_Specifications (
+ Parent (Prim))));
+
+ Insert_After (Curr_Nod, Wrap_Spec);
+ Curr_Nod := Wrap_Spec;
+
+ Analyze (Wrap_Spec);
+ end if;
+
+ Next_Elmt (Prim_Elmt);
+ end loop;
+
+ return;
+ end;
+
+ -- For non-concurrent types, transfer explicit primitives, but
+ -- omit those inherited from the parent of the private view
+ -- since they will be re-inherited later on.
+
+ else
+ Full_List := Primitive_Operations (Full_T);
+
+ while Present (Prim_Elmt) loop
+ Prim := Node (Prim_Elmt);
+
+ if Comes_From_Source (Prim)
+ and then not Contains (Prim, Full_List)
+ then
+ Append_Elmt (Prim, Full_List);
+ end if;
+
+ Next_Elmt (Prim_Elmt);
+ end loop;
+ end if;
+
+ -- Untagged private view
+
+ else
+ Full_List := Primitive_Operations (Full_T);
+
+ -- 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, marked by Check_Operation_From_Private_View
+ -- as dispatching. 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_In (Prim, E_Procedure, E_Function) then
+ Disp_Typ := Find_Dispatching_Type (Prim);
+
+ if Disp_Typ = 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 Disp_Typ /= Full_T
+ then
+
+ -- Verify that it is not otherwise controlled by a
+ -- formal or a return value of type T.
+
+ Check_Controlling_Formals (Disp_Typ, Prim);
+ end if;
+ end if;
+
+ Next_Entity (Prim);
+ end loop;
+ end if;
+
+ -- For the tagged case, the two views can share the same primitive
+ -- operations 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_Direct_Primitive_Operations (Priv_T, Full_List);
+ Set_Class_Wide_Type
+ (Base_Type (Full_T), Class_Wide_Type (Priv_T));
+
+ Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
+ end if;
+ end;
+ end if;
+
+ -- Ada 2005 AI 161: Check preelaboratable initialization consistency
+
+ if Known_To_Have_Preelab_Init (Priv_T) then
+
+ -- Case where there is a pragma Preelaborable_Initialization. We
+ -- always allow this in predefined units, which is a bit of a kludge,
+ -- but it means we don't have to struggle to meet the requirements in
+ -- the RM for having Preelaborable Initialization. Otherwise we
+ -- require that the type meets the RM rules. But we can't check that
+ -- yet, because of the rule about overriding Initialize, so we simply
+ -- set a flag that will be checked at freeze time.
+
+ if not In_Predefined_Unit (Full_T) then
+ Set_Must_Have_Preelab_Init (Full_T);
+ end if;
+ end if;
+
+ -- If pragma CPP_Class was applied to the private type declaration,
+ -- propagate it now to the full type declaration.
+
+ if Is_CPP_Class (Priv_T) then
+ Set_Is_CPP_Class (Full_T);
+ Set_Convention (Full_T, Convention_CPP);
+
+ -- Check that components of imported CPP types do not have default
+ -- expressions.
+
+ Check_CPP_Type_Has_No_Defaults (Full_T);
+ end if;
+
+ -- If the private view has user specified stream attributes, then so has
+ -- the full view.
+
+ -- Why the test, how could these flags be already set in Full_T ???
+
+ if Has_Specified_Stream_Read (Priv_T) then
+ Set_Has_Specified_Stream_Read (Full_T);
+ end if;
+
+ if Has_Specified_Stream_Write (Priv_T) then
+ Set_Has_Specified_Stream_Write (Full_T);
+ end if;
+
+ if Has_Specified_Stream_Input (Priv_T) then
+ Set_Has_Specified_Stream_Input (Full_T);
+ end if;
+
+ if Has_Specified_Stream_Output (Priv_T) then
+ Set_Has_Specified_Stream_Output (Full_T);
+ end if;
+
+ -- Propagate invariants to full type
+
+ if Has_Invariants (Priv_T) then
+ Set_Has_Invariants (Full_T);
+ Set_Invariant_Procedure (Full_T, Invariant_Procedure (Priv_T));
+ end if;
+
+ if Has_Inheritable_Invariants (Priv_T) then
+ Set_Has_Inheritable_Invariants (Full_T);
+ end if;
+
+ -- Propagate predicates to full type
+
+ if Has_Predicates (Priv_T) then
+ Set_Predicate_Function (Priv_T, Predicate_Function (Full_T));
+ Set_Has_Predicates (Full_T);
+ end if;
+ end Process_Full_View;
+
+ -----------------------------------
+ -- Process_Incomplete_Dependents --
+ -----------------------------------
+
+ procedure Process_Incomplete_Dependents
+ (N : Node_Id;
+ Full_T : Entity_Id;
+ Inc_T : Entity_Id)
+ is
+ Inc_Elmt : Elmt_Id;
+ Priv_Dep : Entity_Id;
+ New_Subt : Entity_Id;
+
+ Disc_Constraint : Elist_Id;
+
+ begin
+ if No (Private_Dependents (Inc_T)) then
+ return;
+ end if;
+
+ -- Itypes that may be generated by the completion of an incomplete
+ -- subtype are not used by the back-end and not attached to the tree.
+ -- They are created only for constraint-checking purposes.
+
+ Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
+ while Present (Inc_Elmt) loop
+ Priv_Dep := Node (Inc_Elmt);
+
+ if Ekind (Priv_Dep) = E_Subprogram_Type then
+
+ -- An Access_To_Subprogram type may have a return type or a
+ -- parameter type that is incomplete. Replace with the full view.
+
+ if Etype (Priv_Dep) = Inc_T then
+ Set_Etype (Priv_Dep, Full_T);
+ end if;
+
+ declare
+ Formal : Entity_Id;
+
+ begin
+ Formal := First_Formal (Priv_Dep);
+ while Present (Formal) loop
+ if Etype (Formal) = Inc_T then
+ Set_Etype (Formal, Full_T);
+ end if;
+
+ Next_Formal (Formal);
+ end loop;
+ end;
+
+ elsif Is_Overloadable (Priv_Dep) then
+
+ -- If a subprogram in the incomplete dependents list is primitive
+ -- for a tagged full type then mark it as a dispatching operation,
+ -- check whether it overrides an inherited subprogram, and check
+ -- restrictions on its controlling formals. Note that a protected
+ -- operation is never dispatching: only its wrapper operation
+ -- (which has convention Ada) is.
+
+ if Is_Tagged_Type (Full_T)
+ and then Is_Primitive (Priv_Dep)
+ and then Convention (Priv_Dep) /= Convention_Protected
+ then
+ 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;
+
+ -- Ada 2005 (AI-412): Transform a regular incomplete subtype into a
+ -- corresponding subtype of the full view.
+
+ elsif Ekind (Priv_Dep) = E_Incomplete_Subtype then
+ Set_Subtype_Indication
+ (Parent (Priv_Dep), New_Reference_To (Full_T, Sloc (Priv_Dep)));
+ Set_Etype (Priv_Dep, Full_T);
+ Set_Ekind (Priv_Dep, Subtype_Kind (Ekind (Full_T)));
+ Set_Analyzed (Parent (Priv_Dep), False);
+
+ -- Reanalyze the declaration, suppressing the call to
+ -- Enter_Name to avoid duplicate names.
+
+ Analyze_Subtype_Declaration
+ (N => Parent (Priv_Dep),
+ Skip => True);
+
+ -- 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;
+ In_Iter_Schm : Boolean := False)
+ is
+ Lo, Hi : Node_Id;
+ R_Checks : Check_Result;
+ Insert_Node : Node_Id;
+ Def_Id : Entity_Id;
+
+ begin
+ Analyze_And_Resolve (R, Base_Type (T));
+
+ if Nkind (R) = N_Range then
+
+ -- In SPARK, all ranges should be static, with the exception of the
+ -- discrete type definition of a loop parameter specification.
+
+ if not In_Iter_Schm
+ and then not Is_Static_Range (R)
+ then
+ Check_SPARK_Restriction ("range should be static", R);
+ end if;
+
+ Lo := Low_Bound (R);
+ Hi := High_Bound (R);
+
+ -- We need to ensure validity of the bounds here, because if we
+ -- go ahead and do the expansion, then the expanded code will get
+ -- analyzed with range checks suppressed and we miss the check.
+
+ Validity_Check_Range (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.
+
+ -- The forced evaluation removes side effects from expressions,
+ -- which should occur also in Alfa mode. Otherwise, we end up with
+ -- unexpected insertions of actions at places where this is not
+ -- supposed to occur, e.g. on default parameters of a call.
+
+ 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 := Get_Range_Checks (R, T);
+
+ -- Look up tree to find an appropriate insertion point. We
+ -- can't just use insert_actions because later processing
+ -- depends on the insertion node. Prior to Ada 2012 the
+ -- insertion point could only be a declaration or a loop, but
+ -- quantified expressions can appear within any context in an
+ -- expression, and the insertion point can be any statement,
+ -- pragma, or declaration.
+
+ Insert_Node := Parent (R);
+ while Present (Insert_Node) loop
+ exit when
+ Nkind (Insert_Node) in N_Declaration
+ and then
+ not Nkind_In
+ (Insert_Node, N_Component_Declaration,
+ N_Loop_Parameter_Specification,
+ N_Function_Specification,
+ N_Procedure_Specification);
+
+ exit when Nkind (Insert_Node) in N_Later_Decl_Item
+ or else Nkind (Insert_Node) in
+ N_Statement_Other_Than_Procedure_Call
+ or else Nkind_In (Insert_Node, N_Procedure_Call_Statement,
+ N_Pragma);
+
+ Insert_Node := Parent (Insert_Node);
+ end loop;
+
+ -- Why would Type_Decl not be present??? Without this test,
+ -- short regression tests fail.
+
+ if Present (Insert_Node) then
+
+ -- Case of loop statement. Verify that the range is part
+ -- of the subtype indication of the iteration scheme.
+
+ if Nkind (Insert_Node) = N_Loop_Statement then
+ declare
+ Indic : Node_Id;
+
+ begin
+ Indic := Parent (R);
+ while Present (Indic)
+ and then 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,
+ Insert_Node,
+ Def_Id,
+ Sloc (Insert_Node),
+ R,
+ Do_Before => True);
+ end if;
+ end;
+
+ -- Insertion before a declaration. If the declaration
+ -- includes discriminants, the list of applicable checks
+ -- is given by the caller.
+
+ elsif Nkind (Insert_Node) in N_Declaration then
+ Def_Id := Defining_Identifier (Insert_Node);
+
+ 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 (Insert_Node), R);
+
+ else
+ Insert_Range_Checks
+ (R_Checks,
+ Insert_Node, Def_Id, Sloc (Insert_Node), R);
+
+ end if;
+
+ -- Insertion before a statement. Range appears in the
+ -- context of a quantified expression. Insertion will
+ -- take place when expression is expanded.
+
+ else
+ null;
+ end if;
+ end if;
+ end if;
+ end if;
+
+ -- Case of other than an explicit N_Range node
+
+ -- The forced evaluation removes side effects from expressions, which
+ -- should occur also in Alfa mode. Otherwise, we end up with unexpected
+ -- insertions of actions at places where this is not supposed to occur,
+ -- e.g. on default parameters of a call.
+
+ elsif Expander_Active then
+ Get_Index_Bounds (R, Lo, Hi);
+ Force_Evaluation (Lo);
+ Force_Evaluation (Hi);
+ end if;
+ end Process_Range_Expr_In_Decl;
+
+ --------------------------------------
+ -- Process_Real_Range_Specification --
+ --------------------------------------
+
+ procedure Process_Real_Range_Specification (Def : Node_Id) is
+ Spec : constant Node_Id := Real_Range_Specification (Def);
+ Lo : Node_Id;
+ Hi : Node_Id;
+ Err : Boolean := False;
+
+ procedure Analyze_Bound (N : Node_Id);
+ -- Analyze and check one bound
+
+ -------------------
+ -- Analyze_Bound --
+ -------------------
+
+ procedure Analyze_Bound (N : Node_Id) is
+ begin
+ Analyze_And_Resolve (N, Any_Real);
+
+ if not Is_OK_Static_Expression (N) then
+ Flag_Non_Static_Expr
+ ("bound in real type definition is not static!", N);
+ Err := True;
+ end if;
+ end Analyze_Bound;
+
+ -- Start of processing for Process_Real_Range_Specification
+
+ begin
+ if Present (Spec) then
+ Lo := Low_Bound (Spec);
+ Hi := High_Bound (Spec);
+ Analyze_Bound (Lo);
+ Analyze_Bound (Hi);
+
+ -- If error, clear away junk range specification
+
+ if Err then
+ Set_Real_Range_Specification (Def, Empty);
+ end if;
+ end if;
+ end Process_Real_Range_Specification;
+
+ ---------------------
+ -- Process_Subtype --
+ ---------------------
+
+ function Process_Subtype
+ (S : Node_Id;
+ Related_Nod : Node_Id;
+ Related_Id : Entity_Id := Empty;
+ Suffix : Character := ' ') return Entity_Id
+ is
+ P : Node_Id;
+ Def_Id : Entity_Id;
+ Error_Node : Node_Id;
+ Full_View_Id : Entity_Id;
+ Subtype_Mark_Id : Entity_Id;
+
+ May_Have_Null_Exclusion : Boolean;
+
+ procedure Check_Incomplete (T : Entity_Id);
+ -- Called to verify that an incomplete type is not used prematurely
+
+ ----------------------
+ -- Check_Incomplete --
+ ----------------------
+
+ procedure Check_Incomplete (T : Entity_Id) is
+ begin
+ -- Ada 2005 (AI-412): Incomplete subtypes are legal
+
+ if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type
+ and then
+ not (Ada_Version >= Ada_2005
+ and then
+ (Nkind (Parent (T)) = N_Subtype_Declaration
+ or else
+ (Nkind (Parent (T)) = N_Subtype_Indication
+ and then Nkind (Parent (Parent (T))) =
+ N_Subtype_Declaration)))
+ then
+ Error_Msg_N ("invalid use of type before its full declaration", T);
+ end if;
+ end Check_Incomplete;
+
+ -- Start of processing for Process_Subtype
+
+ begin
+ -- Case of no constraints present
+
+ if Nkind (S) /= N_Subtype_Indication then
+ Find_Type (S);
+ Check_Incomplete (S);
+ P := Parent (S);
+
+ -- Ada 2005 (AI-231): Static check
+
+ if Ada_Version >= Ada_2005
+ and then Present (P)
+ and then Null_Exclusion_Present (P)
+ and then Nkind (P) /= N_Access_To_Object_Definition
+ and then not Is_Access_Type (Entity (S))
+ then
+ Error_Msg_N ("`NOT NULL` only allowed for an access type", S);
+ end if;
+
+ -- The following is ugly, can't we have a range or even a flag???
+
+ May_Have_Null_Exclusion :=
+ Nkind_In (P, N_Access_Definition,
+ N_Access_Function_Definition,
+ N_Access_Procedure_Definition,
+ N_Access_To_Object_Definition,
+ N_Allocator,
+ N_Component_Definition)
+ or else
+ Nkind_In (P, N_Derived_Type_Definition,
+ N_Discriminant_Specification,
+ N_Formal_Object_Declaration,
+ N_Object_Declaration,
+ N_Object_Renaming_Declaration,
+ N_Parameter_Specification,
+ N_Subtype_Declaration);
+
+ -- Create an Itype that is a duplicate of Entity (S) but with the
+ -- null-exclusion attribute.
+
+ if May_Have_Null_Exclusion
+ and then Is_Access_Type (Entity (S))
+ and then Null_Exclusion_Present (P)
+
+ -- No need to check the case of an access to object definition.
+ -- It is correct to define double not-null pointers.
+
+ -- Example:
+ -- type Not_Null_Int_Ptr is not null access Integer;
+ -- type Acc is not null access Not_Null_Int_Ptr;
+
+ and then Nkind (P) /= N_Access_To_Object_Definition
+ then
+ if Can_Never_Be_Null (Entity (S)) then
+ case Nkind (Related_Nod) is
+ when N_Full_Type_Declaration =>
+ if Nkind (Type_Definition (Related_Nod))
+ in N_Array_Type_Definition
+ then
+ Error_Node :=
+ Subtype_Indication
+ (Component_Definition
+ (Type_Definition (Related_Nod)));
+ else
+ Error_Node :=
+ Subtype_Indication (Type_Definition (Related_Nod));
+ end if;
+
+ when N_Subtype_Declaration =>
+ Error_Node := Subtype_Indication (Related_Nod);
+
+ when N_Object_Declaration =>
+ Error_Node := Object_Definition (Related_Nod);
+
+ when N_Component_Declaration =>
+ Error_Node :=
+ Subtype_Indication (Component_Definition (Related_Nod));
+
+ when N_Allocator =>
+ Error_Node := Expression (Related_Nod);
+
+ when others =>
+ pragma Assert (False);
+ Error_Node := Related_Nod;
+ end case;
+
+ Error_Msg_NE
+ ("`NOT NULL` not allowed (& already excludes null)",
+ Error_Node,
+ Entity (S));
+ end if;
+
+ Set_Etype (S,
+ Create_Null_Excluding_Itype
+ (T => Entity (S),
+ Related_Nod => P));
+ Set_Entity (S, Etype (S));
+ end if;
+
+ return Entity (S);
+
+ -- Case of constraint present, so that we have an N_Subtype_Indication
+ -- node (this node is created only if constraints are present).
+
+ else
+ Find_Type (Subtype_Mark (S));
+
+ if Nkind (Parent (S)) /= N_Access_To_Object_Definition
+ and then not
+ (Nkind (Parent (S)) = N_Subtype_Declaration
+ and then Is_Itype (Defining_Identifier (Parent (S))))
+ then
+ Check_Incomplete (Subtype_Mark (S));
+ end if;
+
+ P := Parent (S);
+ Subtype_Mark_Id := Entity (Subtype_Mark (S));
+
+ -- Explicit subtype declaration case
+
+ if Nkind (P) = N_Subtype_Declaration then
+ Def_Id := Defining_Identifier (P);
+
+ -- Explicit derived type definition case
+
+ elsif Nkind (P) = N_Derived_Type_Definition then
+ Def_Id := Defining_Identifier (Parent (P));
+
+ -- Implicit case, the Def_Id must be created as an implicit type.
+ -- The one exception arises in the case of concurrent types, array
+ -- and access types, where other subsidiary implicit types may be
+ -- created and must appear before the main implicit type. In these
+ -- cases we leave Def_Id set to Empty as a signal that Create_Itype
+ -- has not yet been called to create Def_Id.
+
+ else
+ if Is_Array_Type (Subtype_Mark_Id)
+ or else Is_Concurrent_Type (Subtype_Mark_Id)
+ or else Is_Access_Type (Subtype_Mark_Id)
+ then
+ Def_Id := Empty;
+
+ -- For the other cases, we create a new unattached Itype,
+ -- and set the indication to ensure it gets attached later.
+
+ else
+ Def_Id :=
+ Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
+ end if;
+ end if;
+
+ -- If the kind of constraint is invalid for this kind of type,
+ -- then give an error, and then pretend no constraint was given.
+
+ if not Is_Valid_Constraint_Kind
+ (Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
+ then
+ Error_Msg_N
+ ("incorrect constraint for this kind of type", Constraint (S));
+
+ Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
+
+ -- Set Ekind of orphan itype, to prevent cascaded errors
+
+ if Present (Def_Id) then
+ Set_Ekind (Def_Id, Ekind (Any_Type));
+ end if;
+
+ -- Make recursive call, having got rid of the bogus constraint
+
+ return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
+ end if;
+
+ -- Remaining processing depends on type. Select on Base_Type kind to
+ -- ensure getting to the concrete type kind in the case of a private
+ -- subtype (needed when only doing semantic analysis).
+
+ case Ekind (Base_Type (Subtype_Mark_Id)) is
+ when Access_Kind =>
+ Constrain_Access (Def_Id, S, Related_Nod);
+
+ if Expander_Active
+ and then Is_Itype (Designated_Type (Def_Id))
+ and then Nkind (Related_Nod) = N_Subtype_Declaration
+ and then not Is_Incomplete_Type (Designated_Type (Def_Id))
+ then
+ Build_Itype_Reference
+ (Designated_Type (Def_Id), Related_Nod);
+ end if;
+
+ 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);
+
+ if Ekind (Def_Id) = E_Incomplete_Type then
+ Set_Private_Dependents (Def_Id, New_Elmt_List);
+ end if;
+
+ 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);
+
+ -- Introduce an explicit reference to the private subtype,
+ -- to prevent scope anomalies in gigi if first use appears
+ -- in a nested context, e.g. a later function body.
+ -- Should this be generated in other contexts than a full
+ -- type declaration?
+
+ if Is_Itype (Def_Id)
+ and then
+ Nkind (Parent (P)) = N_Full_Type_Declaration
+ then
+ Build_Itype_Reference (Def_Id, Parent (P));
+ end if;
+
+ 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;
+
+ ---------------------------------------
+ -- Check_Anonymous_Access_Components --
+ ---------------------------------------
+
+ procedure Check_Anonymous_Access_Components
+ (Typ_Decl : Node_Id;
+ Typ : Entity_Id;
+ Prev : Entity_Id;
+ Comp_List : Node_Id)
+ is
+ Loc : constant Source_Ptr := Sloc (Typ_Decl);
+ Anon_Access : Entity_Id;
+ Acc_Def : Node_Id;
+ Comp : Node_Id;
+ Comp_Def : Node_Id;
+ Decl : Node_Id;
+ Type_Def : Node_Id;
+
+ procedure Build_Incomplete_Type_Declaration;
+ -- If the record type contains components that include an access to the
+ -- current record, then create an incomplete type declaration for the
+ -- record, to be used as the designated type of the anonymous access.
+ -- This is done only once, and only if there is no previous partial
+ -- view of the type.
+
+ function Designates_T (Subt : Node_Id) return Boolean;
+ -- Check whether a node designates the enclosing record type, or 'Class
+ -- of that type
+
+ function Mentions_T (Acc_Def : Node_Id) return Boolean;
+ -- Check whether an access definition includes a reference to
+ -- the enclosing record type. The reference can be a subtype mark
+ -- in the access definition itself, a 'Class attribute reference, or
+ -- recursively a reference appearing in a parameter specification
+ -- or result definition of an access_to_subprogram definition.
+
+ --------------------------------------
+ -- Build_Incomplete_Type_Declaration --
+ --------------------------------------
+
+ procedure Build_Incomplete_Type_Declaration is
+ Decl : Node_Id;
+ Inc_T : Entity_Id;
+ H : Entity_Id;
+
+ -- Is_Tagged indicates whether the type is tagged. It is tagged if
+ -- it's "is new ... with record" or else "is tagged record ...".
+
+ Is_Tagged : constant Boolean :=
+ (Nkind (Type_Definition (Typ_Decl)) = N_Derived_Type_Definition
+ and then
+ Present
+ (Record_Extension_Part (Type_Definition (Typ_Decl))))
+ or else
+ (Nkind (Type_Definition (Typ_Decl)) = N_Record_Definition
+ and then Tagged_Present (Type_Definition (Typ_Decl)));
+
+ begin
+ -- If there is a previous partial view, no need to create a new one
+ -- If the partial view, given by Prev, is incomplete, If Prev is
+ -- a private declaration, full declaration is flagged accordingly.
+
+ if Prev /= Typ then
+ if Is_Tagged then
+ Make_Class_Wide_Type (Prev);
+ Set_Class_Wide_Type (Typ, Class_Wide_Type (Prev));
+ Set_Etype (Class_Wide_Type (Typ), Typ);
+ end if;
+
+ return;
+
+ elsif Has_Private_Declaration (Typ) then
+
+ -- If we refer to T'Class inside T, and T is the completion of a
+ -- private type, then we need to make sure the class-wide type
+ -- exists.
+
+ if Is_Tagged then
+ Make_Class_Wide_Type (Typ);
+ end if;
+
+ return;
+
+ -- If there was a previous anonymous access type, the incomplete
+ -- type declaration will have been created already.
+
+ elsif Present (Current_Entity (Typ))
+ and then Ekind (Current_Entity (Typ)) = E_Incomplete_Type
+ and then Full_View (Current_Entity (Typ)) = Typ
+ then
+ if Is_Tagged
+ and then Comes_From_Source (Current_Entity (Typ))
+ and then not Is_Tagged_Type (Current_Entity (Typ))
+ then
+ Make_Class_Wide_Type (Typ);
+ Error_Msg_N
+ ("incomplete view of tagged type should be declared tagged??",
+ Parent (Current_Entity (Typ)));
+ end if;
+ return;
+
+ else
+ Inc_T := Make_Defining_Identifier (Loc, Chars (Typ));
+ Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
+
+ -- Type has already been inserted into the current scope. Remove
+ -- it, and add incomplete declaration for type, so that subsequent
+ -- anonymous access types can use it. The entity is unchained from
+ -- the homonym list and from immediate visibility. After analysis,
+ -- the entity in the incomplete declaration becomes immediately
+ -- visible in the record declaration that follows.
+
+ H := Current_Entity (Typ);
+
+ if H = Typ then
+ Set_Name_Entity_Id (Chars (Typ), Homonym (Typ));
+ else
+ while Present (H)
+ and then Homonym (H) /= Typ
+ loop
+ H := Homonym (Typ);
+ end loop;
+
+ Set_Homonym (H, Homonym (Typ));
+ end if;
+
+ Insert_Before (Typ_Decl, Decl);
+ Analyze (Decl);
+ Set_Full_View (Inc_T, Typ);
+
+ if Is_Tagged then
+
+ -- Create a common class-wide type for both views, and set the
+ -- Etype of the class-wide type to the full view.
+
+ Make_Class_Wide_Type (Inc_T);
+ Set_Class_Wide_Type (Typ, Class_Wide_Type (Inc_T));
+ Set_Etype (Class_Wide_Type (Typ), Typ);
+ end if;
+ end if;
+ end Build_Incomplete_Type_Declaration;
+
+ ------------------
+ -- Designates_T --
+ ------------------
+
+ function Designates_T (Subt : Node_Id) return Boolean is
+ Type_Id : constant Name_Id := Chars (Typ);
+
+ function Names_T (Nam : Node_Id) return Boolean;
+ -- The record type has not been introduced in the current scope
+ -- yet, so we must examine the name of the type itself, either
+ -- an identifier T, or an expanded name of the form P.T, where
+ -- P denotes the current scope.
+
+ -------------
+ -- Names_T --
+ -------------
+
+ function Names_T (Nam : Node_Id) return Boolean is
+ begin
+ if Nkind (Nam) = N_Identifier then
+ return Chars (Nam) = Type_Id;
+
+ elsif Nkind (Nam) = N_Selected_Component then
+ if Chars (Selector_Name (Nam)) = Type_Id then
+ if Nkind (Prefix (Nam)) = N_Identifier then
+ return Chars (Prefix (Nam)) = Chars (Current_Scope);
+
+ elsif Nkind (Prefix (Nam)) = N_Selected_Component then
+ return Chars (Selector_Name (Prefix (Nam))) =
+ Chars (Current_Scope);
+ else
+ return False;
+ end if;
+
+ else
+ return False;
+ end if;
+
+ else
+ return False;
+ end if;
+ end Names_T;
+
+ -- Start of processing for Designates_T
+
+ begin
+ if Nkind (Subt) = N_Identifier then
+ return Chars (Subt) = Type_Id;
+
+ -- Reference can be through an expanded name which has not been
+ -- analyzed yet, and which designates enclosing scopes.
+
+ elsif Nkind (Subt) = N_Selected_Component then
+ if Names_T (Subt) then
+ return True;
+
+ -- Otherwise it must denote an entity that is already visible.
+ -- The access definition may name a subtype of the enclosing
+ -- type, if there is a previous incomplete declaration for it.
+
+ else
+ Find_Selected_Component (Subt);
+ return
+ Is_Entity_Name (Subt)
+ and then Scope (Entity (Subt)) = Current_Scope
+ and then
+ (Chars (Base_Type (Entity (Subt))) = Type_Id
+ or else
+ (Is_Class_Wide_Type (Entity (Subt))
+ and then
+ Chars (Etype (Base_Type (Entity (Subt)))) =
+ Type_Id));
+ end if;
+
+ -- A reference to the current type may appear as the prefix of
+ -- a 'Class attribute.
+
+ elsif Nkind (Subt) = N_Attribute_Reference
+ and then Attribute_Name (Subt) = Name_Class
+ then
+ return Names_T (Prefix (Subt));
+
+ else
+ return False;
+ end if;
+ end Designates_T;
+
+ ----------------
+ -- Mentions_T --
+ ----------------
+
+ function Mentions_T (Acc_Def : Node_Id) return Boolean is
+ Param_Spec : Node_Id;
+
+ Acc_Subprg : constant Node_Id :=
+ Access_To_Subprogram_Definition (Acc_Def);
+
+ begin
+ if No (Acc_Subprg) then
+ return Designates_T (Subtype_Mark (Acc_Def));
+ end if;
+
+ -- Component is an access_to_subprogram: examine its formals,
+ -- and result definition in the case of an access_to_function.
+
+ Param_Spec := First (Parameter_Specifications (Acc_Subprg));
+ while Present (Param_Spec) loop
+ if Nkind (Parameter_Type (Param_Spec)) = N_Access_Definition
+ and then Mentions_T (Parameter_Type (Param_Spec))
+ then
+ return True;
+
+ elsif Designates_T (Parameter_Type (Param_Spec)) then
+ return True;
+ end if;
+
+ Next (Param_Spec);
+ end loop;
+
+ if Nkind (Acc_Subprg) = N_Access_Function_Definition then
+ if Nkind (Result_Definition (Acc_Subprg)) =
+ N_Access_Definition
+ then
+ return Mentions_T (Result_Definition (Acc_Subprg));
+ else
+ return Designates_T (Result_Definition (Acc_Subprg));
+ end if;
+ end if;
+
+ return False;
+ end Mentions_T;
+
+ -- Start of processing for Check_Anonymous_Access_Components
+
+ begin
+ if No (Comp_List) then
+ return;
+ end if;
+
+ Comp := First (Component_Items (Comp_List));
+ while Present (Comp) loop
+ if Nkind (Comp) = N_Component_Declaration
+ and then Present
+ (Access_Definition (Component_Definition (Comp)))
+ and then
+ Mentions_T (Access_Definition (Component_Definition (Comp)))
+ then
+ Comp_Def := Component_Definition (Comp);
+ Acc_Def :=
+ Access_To_Subprogram_Definition
+ (Access_Definition (Comp_Def));
+
+ Build_Incomplete_Type_Declaration;
+ Anon_Access := Make_Temporary (Loc, 'S');
+
+ -- Create a declaration for the anonymous access type: either
+ -- an access_to_object or an access_to_subprogram.
+
+ if Present (Acc_Def) then
+ if Nkind (Acc_Def) = N_Access_Function_Definition then
+ Type_Def :=
+ Make_Access_Function_Definition (Loc,
+ Parameter_Specifications =>
+ Parameter_Specifications (Acc_Def),
+ Result_Definition => Result_Definition (Acc_Def));
+ else
+ Type_Def :=
+ Make_Access_Procedure_Definition (Loc,
+ Parameter_Specifications =>
+ Parameter_Specifications (Acc_Def));
+ end if;
+
+ else
+ Type_Def :=
+ Make_Access_To_Object_Definition (Loc,
+ Subtype_Indication =>
+ Relocate_Node
+ (Subtype_Mark
+ (Access_Definition (Comp_Def))));
+
+ Set_Constant_Present
+ (Type_Def, Constant_Present (Access_Definition (Comp_Def)));
+ Set_All_Present
+ (Type_Def, All_Present (Access_Definition (Comp_Def)));
+ end if;
+
+ Set_Null_Exclusion_Present
+ (Type_Def,
+ Null_Exclusion_Present (Access_Definition (Comp_Def)));
+
+ Decl :=
+ Make_Full_Type_Declaration (Loc,
+ Defining_Identifier => Anon_Access,
+ Type_Definition => Type_Def);
+
+ Insert_Before (Typ_Decl, Decl);
+ Analyze (Decl);
+
+ -- If an access to subprogram, create the extra formals
+
+ if Present (Acc_Def) then
+ Create_Extra_Formals (Designated_Type (Anon_Access));
+
+ -- If an access to object, preserve entity of designated type,
+ -- for ASIS use, before rewriting the component definition.
+
+ else
+ declare
+ Desig : Entity_Id;
+
+ begin
+ Desig := Entity (Subtype_Indication (Type_Def));
+
+ -- If the access definition is to the current record,
+ -- the visible entity at this point is an incomplete
+ -- type. Retrieve the full view to simplify ASIS queries
+
+ if Ekind (Desig) = E_Incomplete_Type then
+ Desig := Full_View (Desig);
+ end if;
+
+ Set_Entity
+ (Subtype_Mark (Access_Definition (Comp_Def)), Desig);
+ end;
+ end if;
+
+ Rewrite (Comp_Def,
+ Make_Component_Definition (Loc,
+ Subtype_Indication =>
+ New_Occurrence_Of (Anon_Access, Loc)));
+
+ if Ekind (Designated_Type (Anon_Access)) = E_Subprogram_Type then
+ Set_Ekind (Anon_Access, E_Anonymous_Access_Subprogram_Type);
+ else
+ Set_Ekind (Anon_Access, E_Anonymous_Access_Type);
+ end if;
+
+ Set_Is_Local_Anonymous_Access (Anon_Access);
+ end if;
+
+ Next (Comp);
+ end loop;
+
+ if Present (Variant_Part (Comp_List)) then
+ declare
+ V : Node_Id;
+ begin
+ V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
+ while Present (V) loop
+ Check_Anonymous_Access_Components
+ (Typ_Decl, Typ, Prev, Component_List (V));
+ Next_Non_Pragma (V);
+ end loop;
+ end;
+ end if;
+ end Check_Anonymous_Access_Components;
+
+ ----------------------------------
+ -- Preanalyze_Assert_Expression --
+ ----------------------------------
+
+ procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id) is
+ begin
+ In_Assertion_Expr := In_Assertion_Expr + 1;
+ Preanalyze_Spec_Expression (N, T);
+ In_Assertion_Expr := In_Assertion_Expr - 1;
+ end Preanalyze_Assert_Expression;
+
+ --------------------------------
+ -- Preanalyze_Spec_Expression --
+ --------------------------------
+
+ procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id) is
+ Save_In_Spec_Expression : constant Boolean := In_Spec_Expression;
+ begin
+ In_Spec_Expression := True;
+ Preanalyze_And_Resolve (N, T);
+ In_Spec_Expression := Save_In_Spec_Expression;
+ end Preanalyze_Spec_Expression;
+
+ -----------------------------
+ -- 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
+ -- These flags must be initialized before calling Process_Discriminants
+ -- because this routine makes use of them.
+
+ Set_Ekind (T, E_Record_Type);
+ Set_Etype (T, T);
+ Init_Size_Align (T);
+ Set_Interfaces (T, No_Elist);
+ Set_Stored_Constraint (T, No_Elist);
+
+ -- Normal case
+
+ if Ada_Version < Ada_2005
+ or else not Interface_Present (Def)
+ then
+ if Limited_Present (Def) then
+ Check_SPARK_Restriction ("limited is not allowed", N);
+ end if;
+
+ if Abstract_Present (Def) then
+ Check_SPARK_Restriction ("abstract is not allowed", N);
+ end if;
+
+ -- The flag Is_Tagged_Type might have already been set by
+ -- Find_Type_Name if it detected an error for declaration T. This
+ -- arises in the case of private tagged types where the full view
+ -- omits the word tagged.
+
+ Is_Tagged :=
+ Tagged_Present (Def)
+ or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
+
+ Set_Is_Tagged_Type (T, Is_Tagged);
+ Set_Is_Limited_Record (T, Limited_Present (Def));
+
+ -- Type is abstract if full declaration carries keyword, or if
+ -- previous partial view did.
+
+ Set_Is_Abstract_Type (T, Is_Abstract_Type (T)
+ or else Abstract_Present (Def));
+
+ else
+ Check_SPARK_Restriction ("interface is not allowed", N);
+
+ Is_Tagged := True;
+ Analyze_Interface_Declaration (T, Def);
+
+ if Present (Discriminant_Specifications (N)) then
+ Error_Msg_N
+ ("interface types cannot have discriminants",
+ Defining_Identifier
+ (First (Discriminant_Specifications (N))));
+ end if;
+ end if;
+
+ -- First pass: if there are self-referential access components,
+ -- create the required anonymous access type declarations, and if
+ -- need be an incomplete type declaration for T itself.
+
+ Check_Anonymous_Access_Components (N, T, Prev, Component_List (Def));
+
+ if Ada_Version >= Ada_2005
+ and then Present (Interface_List (Def))
+ then
+ Check_Interfaces (N, Def);
+
+ declare
+ Ifaces_List : Elist_Id;
+
+ begin
+ -- Ada 2005 (AI-251): Collect the list of progenitors that are not
+ -- already in the parents.
+
+ Collect_Interfaces
+ (T => T,
+ Ifaces_List => Ifaces_List,
+ Exclude_Parents => True);
+
+ Set_Interfaces (T, Ifaces_List);
+ end;
+ end if;
+
+ -- Records constitute a scope for the component declarations within.
+ -- The scope is created prior to the processing of these declarations.
+ -- Discriminants are processed first, so that they are visible when
+ -- processing the other components. The Ekind of the record type itself
+ -- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
+
+ -- Enter record scope
+
+ Push_Scope (T);
+
+ -- If an incomplete or private type declaration was already given for
+ -- the type, then this scope already exists, and the discriminants have
+ -- been declared within. We must verify that the full declaration
+ -- matches the incomplete one.
+
+ Check_Or_Process_Discriminants (N, T, Prev);
+
+ Set_Is_Constrained (T, not Has_Discriminants (T));
+ Set_Has_Delayed_Freeze (T, True);
+
+ -- For tagged types add a manually analyzed component corresponding
+ -- to the component _tag, the corresponding piece of tree will be
+ -- expanded as part of the freezing actions if it is not a CPP_Class.
+
+ if Is_Tagged then
+
+ -- Do not add the tag unless we are in expansion mode
+
+ if Expander_Active then
+ Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
+ Enter_Name (Tag_Comp);
+
+ Set_Ekind (Tag_Comp, E_Component);
+ Set_Is_Tag (Tag_Comp);
+ Set_Is_Aliased (Tag_Comp);
+ Set_Etype (Tag_Comp, RTE (RE_Tag));
+ Set_DT_Entry_Count (Tag_Comp, No_Uint);
+ Set_Original_Record_Component (Tag_Comp, Tag_Comp);
+ Init_Component_Location (Tag_Comp);
+
+ -- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
+ -- implemented interfaces.
+
+ if Has_Interfaces (T) then
+ Add_Interface_Tag_Components (N, T);
+ end if;
+ end if;
+
+ Make_Class_Wide_Type (T);
+ Set_Direct_Primitive_Operations (T, New_Elmt_List);
+ end if;
+
+ -- We must suppress range checks when processing record components in
+ -- the presence of discriminants, since we don't want spurious checks to
+ -- be generated during their analysis, but Suppress_Range_Checks flags
+ -- must be reset the after processing the record definition.
+
+ -- Note: this is the only use of Kill_Range_Checks, and is a bit odd,
+ -- couldn't we just use the normal range check suppression method here.
+ -- That would seem cleaner ???
+
+ 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;
+
+ -- Ada 2005 (AI-251 and AI-345): Derive the interface subprograms of all
+ -- the implemented interfaces and associate them an aliased entity.
+
+ if Is_Tagged
+ and then not Is_Empty_List (Interface_List (Def))
+ then
+ Derive_Progenitor_Subprograms (T, T);
+ end if;
+
+ Check_Function_Writable_Actuals (N);
+ 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;
+
+ -- In SPARK, tagged types and type extensions may only be declared in
+ -- the specification of library unit packages.
+
+ if Present (Def) and then Is_Tagged_Type (T) then
+ declare
+ Typ : Node_Id;
+ Ctxt : Node_Id;
+
+ begin
+ if Nkind (Parent (Def)) = N_Full_Type_Declaration then
+ Typ := Parent (Def);
+ else
+ pragma Assert
+ (Nkind (Parent (Def)) = N_Derived_Type_Definition);
+ Typ := Parent (Parent (Def));
+ end if;
+
+ Ctxt := Parent (Typ);
+
+ if Nkind (Ctxt) = N_Package_Body
+ and then Nkind (Parent (Ctxt)) = N_Compilation_Unit
+ then
+ Check_SPARK_Restriction
+ ("type should be defined in package specification", Typ);
+
+ elsif Nkind (Ctxt) /= N_Package_Specification
+ or else Nkind (Parent (Parent (Ctxt))) /= N_Compilation_Unit
+ then
+ Check_SPARK_Restriction
+ ("type should be defined in library unit package", Typ);
+ end if;
+ end;
+ end if;
+
+ Final_Storage_Only := not Is_Controlled (T);
+
+ -- Ada 2005: check whether an explicit Limited is present in a derived
+ -- type declaration.
+
+ if Nkind (Parent (Def)) = N_Derived_Type_Definition
+ and then Limited_Present (Parent (Def))
+ then
+ Set_Is_Limited_Record (T);
+ end if;
+
+ -- If the component list of a record type is defined by the reserved
+ -- word null and there is no discriminant part, then the record type has
+ -- no components and all records of the type are null records (RM 3.7)
+ -- This procedure is also called to process the extension part of a
+ -- record extension, in which case the current scope may have inherited
+ -- components.
+
+ if No (Def)
+ or else No (Component_List (Def))
+ or else Null_Present (Component_List (Def))
+ then
+ if not Is_Tagged_Type (T) then
+ Check_SPARK_Restriction ("non-tagged record cannot be null", Def);
+ end if;
+
+ else
+ Analyze_Declarations (Component_Items (Component_List (Def)));
+
+ if Present (Variant_Part (Component_List (Def))) then
+ Check_SPARK_Restriction ("variant part is not allowed", Def);
+ 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. Exclude malformed itypes from illegal declarations,
+ -- whose Ekind may be void.
+
+ Component := First_Entity (Current_Scope);
+ while Present (Component) loop
+ if Ekind (Component) = E_Void
+ and then not Is_Itype (Component)
+ 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;
+
+ -- Do not set Has_Controlled_Component on a class-wide equivalent
+ -- type. See Make_CW_Equivalent_Type.
+
+ elsif not Is_Class_Wide_Equivalent_Type (T)
+ and then (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 also.
+
+ 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);
+
+ -- Before the freeze point, the bounds of a fixed point are universal
+ -- and carry the corresponding type.
+
+ Set_Etype (Low_Bound (S), Universal_Real);
+ Set_Etype (High_Bound (S), Universal_Real);
+ 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
+ -- Defend against previous error
+
+ if Nkind (R) = N_Error then
+ return;
+ end if;
+
+ 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_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);
+
+ -- In formal verification mode, restrict the base type's range to the
+ -- minimum allowed by RM 3.5.4, namely the smallest symmetric range
+ -- around zero with a possible extra negative value that contains the
+ -- subtype range. Keep Size, RM_Size and First_Rep_Item info, which
+ -- should not be relied upon in formal verification.
+
+ if Strict_Alfa_Mode then
+ declare
+ Sym_Hi_Val : Uint;
+ Sym_Lo_Val : Uint;
+ Dloc : constant Source_Ptr := Sloc (Def);
+ Lbound : Node_Id;
+ Ubound : Node_Id;
+ Bounds : Node_Id;
+
+ begin
+ -- If the subtype range is empty, the smallest base type range
+ -- is the symmetric range around zero containing Lo_Val and
+ -- Hi_Val.
+
+ if UI_Gt (Lo_Val, Hi_Val) then
+ Sym_Hi_Val := UI_Max (UI_Abs (Lo_Val), UI_Abs (Hi_Val));
+ Sym_Lo_Val := UI_Negate (Sym_Hi_Val);
+
+ -- Otherwise, if the subtype range is not empty and Hi_Val has
+ -- the largest absolute value, Hi_Val is non negative and the
+ -- smallest base type range is the symmetric range around zero
+ -- containing Hi_Val.
+
+ elsif UI_Le (UI_Abs (Lo_Val), UI_Abs (Hi_Val)) then
+ Sym_Hi_Val := Hi_Val;
+ Sym_Lo_Val := UI_Negate (Hi_Val);
+
+ -- Otherwise, the subtype range is not empty, Lo_Val has the
+ -- strictly largest absolute value, Lo_Val is negative and the
+ -- smallest base type range is the symmetric range around zero
+ -- with an extra negative value Lo_Val.
+
+ else
+ Sym_Lo_Val := Lo_Val;
+ Sym_Hi_Val := UI_Sub (UI_Negate (Lo_Val), Uint_1);
+ end if;
+
+ Lbound := Make_Integer_Literal (Dloc, Sym_Lo_Val);
+ Ubound := Make_Integer_Literal (Dloc, Sym_Hi_Val);
+ Set_Is_Static_Expression (Lbound);
+ Set_Is_Static_Expression (Ubound);
+ Analyze_And_Resolve (Lbound, Any_Integer);
+ Analyze_And_Resolve (Ubound, Any_Integer);
+
+ Bounds := Make_Range (Dloc, Lbound, Ubound);
+ Set_Etype (Bounds, Base_Typ);
+
+ Set_Scalar_Range (Implicit_Base, Bounds);
+ end;
+
+ else
+ Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
+ end if;
+
+ 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;