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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 3 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Elists; use Elists;
with Einfo; use Einfo;
with Errout; use Errout;
with Eval_Fat; use Eval_Fat;
with Exp_Ch3; use Exp_Ch3;
with Exp_Dist; use Exp_Dist;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Itypes; use Itypes;
with Layout; use Layout;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Nmake; use Nmake;
with Opt; use Opt;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Case; use Sem_Case;
with Sem_Cat; use Sem_Cat;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Elim; use Sem_Elim;
with Sem_Eval; use Sem_Eval;
with Sem_Mech; use Sem_Mech;
with Sem_Res; use Sem_Res;
with Sem_Smem; use Sem_Smem;
with Sem_Type; use Sem_Type;
with Sem_Util; use Sem_Util;
with Sem_Warn; use Sem_Warn;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Ttypes; use Ttypes;
with Uintp; use Uintp;
with Urealp; use Urealp;
package body Sem_Ch3 is
-----------------------
-- Local Subprograms --
-----------------------
procedure Add_Interface_Tag_Components
(N : Node_Id; Typ : Entity_Id);
-- Ada 2005 (AI-251): Add the tag components corresponding to all the
-- abstract interface types implemented by a record type or a derived
-- record type.
procedure Build_Derived_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True);
-- Create and decorate a Derived_Type given the Parent_Type entity. N is
-- the N_Full_Type_Declaration node containing the derived type definition.
-- Parent_Type is the entity for the parent type in the derived type
-- definition and Derived_Type the actual derived type. Is_Completion must
-- be set to False if Derived_Type is the N_Defining_Identifier node in N
-- (ie Derived_Type = Defining_Identifier (N)). In this case N is not the
-- completion of a private type declaration. If Is_Completion is set to
-- True, N is the completion of a private type declaration and Derived_Type
-- is different from the defining identifier inside N (i.e. Derived_Type /=
-- Defining_Identifier (N)). Derive_Subps indicates whether the parent
-- subprograms should be derived. The only case where this parameter is
-- False is when Build_Derived_Type is recursively called to process an
-- implicit derived full type for a type derived from a private type (in
-- that case the subprograms must only be derived for the private view of
-- the type).
-- ??? These flags need a bit of re-examination and re-documentation:
-- ??? are they both necessary (both seem related to the recursion)?
procedure Build_Derived_Access_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived access type,
-- create an implicit base if the parent type is constrained or if the
-- subtype indication has a constraint.
procedure Build_Derived_Array_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived array type,
-- create an implicit base if the parent type is constrained or if the
-- subtype indication has a constraint.
procedure Build_Derived_Concurrent_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived task or pro-
-- tected type, inherit entries and protected subprograms, check legality
-- of discriminant constraints if any.
procedure Build_Derived_Enumeration_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For a derived enumeration
-- type, we must create a new list of literals. Types derived from
-- Character and Wide_Character are special-cased.
procedure Build_Derived_Numeric_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Type. For numeric types, create
-- an anonymous base type, and propagate constraint to subtype if needed.
procedure Build_Derived_Private_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True);
-- Subsidiary procedure to Build_Derived_Type. This procedure is complex
-- because the parent may or may not have a completion, and the derivation
-- may itself be a completion.
procedure Build_Derived_Record_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Derive_Subps : Boolean := True);
-- Subsidiary procedure for Build_Derived_Type and
-- Analyze_Private_Extension_Declaration used for tagged and untagged
-- record types. All parameters are as in Build_Derived_Type except that
-- N, in addition to being an N_Full_Type_Declaration node, can also be an
-- N_Private_Extension_Declaration node. See the definition of this routine
-- for much more info. Derive_Subps indicates whether subprograms should
-- be derived from the parent type. The only case where Derive_Subps is
-- False is for an implicit derived full type for a type derived from a
-- private type (see Build_Derived_Type).
procedure Complete_Subprograms_Derivation
(Partial_View : Entity_Id;
Derived_Type : Entity_Id);
-- Ada 2005 (AI-251): Used to complete type derivation of private tagged
-- types implementing interfaces. In this case some interface primitives
-- may have been overriden with the partial-view and, instead of
-- re-calculating them, they are included in the list of primitive
-- operations of the full-view.
function Inherit_Components
(N : Node_Id;
Parent_Base : Entity_Id;
Derived_Base : Entity_Id;
Is_Tagged : Boolean;
Inherit_Discr : Boolean;
Discs : Elist_Id) return Elist_Id;
-- Called from Build_Derived_Record_Type to inherit the components of
-- Parent_Base (a base type) into the Derived_Base (the derived base type).
-- For more information on derived types and component inheritance please
-- consult the comment above the body of Build_Derived_Record_Type.
--
-- N is the original derived type declaration
--
-- Is_Tagged is set if we are dealing with tagged types
--
-- If Inherit_Discr is set, Derived_Base inherits its discriminants
-- from Parent_Base, otherwise no discriminants are inherited.
--
-- Discs gives the list of constraints that apply to Parent_Base in the
-- derived type declaration. If Discs is set to No_Elist, then we have
-- the following situation:
--
-- type Parent (D1..Dn : ..) is [tagged] record ...;
-- type Derived is new Parent [with ...];
--
-- which gets treated as
--
-- type Derived (D1..Dn : ..) is new Parent (D1,..,Dn) [with ...];
--
-- For untagged types the returned value is an association list. The list
-- starts from the association (Parent_Base => Derived_Base), and then it
-- contains a sequence of the associations of the form
--
-- (Old_Component => New_Component),
--
-- where Old_Component is the Entity_Id of a component in Parent_Base
-- and New_Component is the Entity_Id of the corresponding component
-- in Derived_Base. For untagged records, this association list is
-- needed when copying the record declaration for the derived base.
-- In the tagged case the value returned is irrelevant.
procedure Build_Discriminal (Discrim : Entity_Id);
-- Create the discriminal corresponding to discriminant Discrim, that is
-- the parameter corresponding to Discrim to be used in initialization
-- procedures for the type where Discrim is a discriminant. Discriminals
-- are not used during semantic analysis, and are not fully defined
-- entities until expansion. Thus they are not given a scope until
-- initialization procedures are built.
function Build_Discriminant_Constraints
(T : Entity_Id;
Def : Node_Id;
Derived_Def : Boolean := False) return Elist_Id;
-- Validate discriminant constraints, and return the list of the
-- constraints in order of discriminant declarations. T is the
-- discriminated unconstrained type. Def is the N_Subtype_Indication node
-- where the discriminants constraints for T are specified. Derived_Def is
-- True if we are building the discriminant constraints in a derived type
-- definition of the form "type D (...) is new T (xxx)". In this case T is
-- the parent type and Def is the constraint "(xxx)" on T and this routine
-- sets the Corresponding_Discriminant field of the discriminants in the
-- derived type D to point to the corresponding discriminants in the parent
-- type T.
procedure Build_Discriminated_Subtype
(T : Entity_Id;
Def_Id : Entity_Id;
Elist : Elist_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False);
-- Subsidiary procedure to Constrain_Discriminated_Type and to
-- Process_Incomplete_Dependents. Given
--
-- T (a possibly discriminated base type)
-- Def_Id (a very partially built subtype for T),
--
-- the call completes Def_Id to be the appropriate E_*_Subtype.
--
-- The Elist is the list of discriminant constraints if any (it is set to
-- No_Elist if T is not a discriminated type, and to an empty list if
-- T has discriminants but there are no discriminant constraints). The
-- Related_Nod is the same as Decl_Node in Create_Constrained_Components.
-- The For_Access says whether or not this subtype is really constraining
-- an access type. That is its sole purpose is the designated type of an
-- access type -- in which case a Private_Subtype Is_For_Access_Subtype
-- is built to avoid freezing T when the access subtype is frozen.
function Build_Scalar_Bound
(Bound : Node_Id;
Par_T : Entity_Id;
Der_T : Entity_Id) return Node_Id;
-- The bounds of a derived scalar type are conversions of the bounds of
-- the parent type. Optimize the representation if the bounds are literals.
-- Needs a more complete spec--what are the parameters exactly, and what
-- exactly is the returned value, and how is Bound affected???
procedure Build_Underlying_Full_View
(N : Node_Id;
Typ : Entity_Id;
Par : Entity_Id);
-- If the completion of a private type is itself derived from a private
-- type, or if the full view of a private subtype is itself private, the
-- back-end has no way to compute the actual size of this type. We build
-- an internal subtype declaration of the proper parent type to convey
-- this information. This extra mechanism is needed because a full
-- view cannot itself have a full view (it would get clobbered during
-- view exchanges).
procedure Check_Access_Discriminant_Requires_Limited
(D : Node_Id;
Loc : Node_Id);
-- Check the restriction that the type to which an access discriminant
-- belongs must be a concurrent type or a descendant of a type with
-- the reserved word 'limited' in its declaration.
procedure Check_Delta_Expression (E : Node_Id);
-- Check that the expression represented by E is suitable for use
-- as a delta expression, i.e. it is of real type and is static.
procedure Check_Digits_Expression (E : Node_Id);
-- Check that the expression represented by E is suitable for use as
-- a digits expression, i.e. it is of integer type, positive and static.
procedure Check_Initialization (T : Entity_Id; Exp : Node_Id);
-- Validate the initialization of an object declaration. T is the
-- required type, and Exp is the initialization expression.
procedure Check_Or_Process_Discriminants
(N : Node_Id;
T : Entity_Id;
Prev : Entity_Id := Empty);
-- If T is the full declaration of an incomplete or private type, check
-- the conformance of the discriminants, otherwise process them. Prev
-- is the entity of the partial declaration, if any.
procedure Check_Real_Bound (Bound : Node_Id);
-- Check given bound for being of real type and static. If not, post an
-- appropriate message, and rewrite the bound with the real literal zero.
procedure Constant_Redeclaration
(Id : Entity_Id;
N : Node_Id;
T : out Entity_Id);
-- Various checks on legality of full declaration of deferred constant.
-- Id is the entity for the redeclaration, N is the N_Object_Declaration,
-- node. The caller has not yet set any attributes of this entity.
procedure Convert_Scalar_Bounds
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Loc : Source_Ptr);
-- For derived scalar types, convert the bounds in the type definition
-- to the derived type, and complete their analysis. Given a constraint
-- of the form:
-- .. new T range Lo .. Hi;
-- Lo and Hi are analyzed and resolved with T'Base, the parent_type.
-- The bounds of the derived type (the anonymous base) are copies of
-- Lo and Hi. Finally, the bounds of the derived subtype are conversions
-- of those bounds to the derived_type, so that their typing is
-- consistent.
procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id);
-- Copies attributes from array base type T2 to array base type T1.
-- Copies only attributes that apply to base types, but not subtypes.
procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id);
-- Copies attributes from array subtype T2 to array subtype T1. Copies
-- attributes that apply to both subtypes and base types.
procedure Create_Constrained_Components
(Subt : Entity_Id;
Decl_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id);
-- Build the list of entities for a constrained discriminated record
-- subtype. If a component depends on a discriminant, replace its subtype
-- using the discriminant values in the discriminant constraint.
-- Subt is the defining identifier for the subtype whose list of
-- constrained entities we will create. Decl_Node is the type declaration
-- node where we will attach all the itypes created. Typ is the base
-- discriminated type for the subtype Subt. Constraints is the list of
-- discriminant constraints for Typ.
function Constrain_Component_Type
(Comp : Entity_Id;
Constrained_Typ : Entity_Id;
Related_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id) return Entity_Id;
-- Given a discriminated base type Typ, a list of discriminant constraint
-- Constraints for Typ and a component of Typ, with type Compon_Type,
-- create and return the type corresponding to Compon_type where all
-- discriminant references are replaced with the corresponding
-- constraint. If no discriminant references occur in Compon_Typ then
-- return it as is. Constrained_Typ is the final constrained subtype to
-- which the constrained Compon_Type belongs. Related_Node is the node
-- where we will attach all the itypes created.
procedure Constrain_Access
(Def_Id : in out Entity_Id;
S : Node_Id;
Related_Nod : Node_Id);
-- Apply a list of constraints to an access type. If Def_Id is empty, it is
-- an anonymous type created for a subtype indication. In that case it is
-- created in the procedure and attached to Related_Nod.
procedure Constrain_Array
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character);
-- Apply a list of index constraints to an unconstrained array type. The
-- first parameter is the entity for the resulting subtype. A value of
-- Empty for Def_Id indicates that an implicit type must be created, but
-- creation is delayed (and must be done by this procedure) because other
-- subsidiary implicit types must be created first (which is why Def_Id
-- is an in/out parameter). The second parameter is a subtype indication
-- node for the constrained array to be created (e.g. something of the
-- form string (1 .. 10)). Related_Nod gives the place where this type
-- has to be inserted in the tree. The Related_Id and Suffix parameters
-- are used to build the associated Implicit type name.
procedure Constrain_Concurrent
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character);
-- Apply list of discriminant constraints to an unconstrained concurrent
-- type.
--
-- SI is the N_Subtype_Indication node containing the constraint and
-- the unconstrained type to constrain.
--
-- Def_Id is the entity for the resulting constrained subtype. A value
-- of Empty for Def_Id indicates that an implicit type must be created,
-- but creation is delayed (and must be done by this procedure) because
-- other subsidiary implicit types must be created first (which is why
-- Def_Id is an in/out parameter).
--
-- Related_Nod gives the place where this type has to be inserted
-- in the tree
--
-- The last two arguments are used to create its external name if needed.
function Constrain_Corresponding_Record
(Prot_Subt : Entity_Id;
Corr_Rec : Entity_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id) return Entity_Id;
-- When constraining a protected type or task type with discriminants,
-- constrain the corresponding record with the same discriminant values.
procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id);
-- Constrain a decimal fixed point type with a digits constraint and/or a
-- range constraint, and build E_Decimal_Fixed_Point_Subtype entity.
procedure Constrain_Discriminated_Type
(Def_Id : Entity_Id;
S : Node_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False);
-- Process discriminant constraints of composite type. Verify that values
-- have been provided for all discriminants, that the original type is
-- unconstrained, and that the types of the supplied expressions match
-- the discriminant types. The first three parameters are like in routine
-- Constrain_Concurrent. See Build_Discriminated_Subtype for an explanation
-- of For_Access.
procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id);
-- Constrain an enumeration type with a range constraint. This is identical
-- to Constrain_Integer, but for the Ekind of the resulting subtype.
procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id);
-- Constrain a floating point type with either a digits constraint
-- and/or a range constraint, building a E_Floating_Point_Subtype.
procedure Constrain_Index
(Index : Node_Id;
S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character;
Suffix_Index : Nat);
-- Process an index constraint in a constrained array declaration. The
-- constraint can be a subtype name, or a range with or without an
-- explicit subtype mark. The index is the corresponding index of the
-- unconstrained array. The Related_Id and Suffix parameters are used to
-- build the associated Implicit type name.
procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id);
-- Build subtype of a signed or modular integer type
procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id);
-- Constrain an ordinary fixed point type with a range constraint, and
-- build an E_Ordinary_Fixed_Point_Subtype entity.
procedure Copy_And_Swap (Priv, Full : Entity_Id);
-- Copy the Priv entity into the entity of its full declaration
-- then swap the two entities in such a manner that the former private
-- type is now seen as a full type.
procedure Decimal_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id);
-- Create a new decimal fixed point type, and apply the constraint to
-- obtain a subtype of this new type.
procedure Complete_Private_Subtype
(Priv : Entity_Id;
Full : Entity_Id;
Full_Base : Entity_Id;
Related_Nod : Node_Id);
-- Complete the implicit full view of a private subtype by setting the
-- appropriate semantic fields. If the full view of the parent is a record
-- type, build constrained components of subtype.
procedure Derive_Interface_Subprograms
(Derived_Type : Entity_Id);
-- Ada 2005 (AI-251): Subsidiary procedure to Build_Derived_Record_Type.
-- Traverse the list of implemented interfaces and derive all their
-- subprograms.
procedure Derived_Standard_Character
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id);
-- Subsidiary procedure to Build_Derived_Enumeration_Type which handles
-- derivations from types Standard.Character and Standard.Wide_Character.
procedure Derived_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Is_Completion : Boolean);
-- Process a derived type declaration. This routine will invoke
-- Build_Derived_Type to process the actual derived type definition.
-- Parameters N and Is_Completion have the same meaning as in
-- Build_Derived_Type. T is the N_Defining_Identifier for the entity
-- defined in the N_Full_Type_Declaration node N, that is T is the derived
-- type.
procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Insert each literal in symbol table, as an overloadable identifier. Each
-- enumeration type is mapped into a sequence of integers, and each literal
-- is defined as a constant with integer value. If any of the literals are
-- character literals, the type is a character type, which means that
-- strings are legal aggregates for arrays of components of the type.
function Expand_To_Stored_Constraint
(Typ : Entity_Id;
Constraint : Elist_Id) return Elist_Id;
-- Given a Constraint (i.e. a list of expressions) on the discriminants of
-- Typ, expand it into a constraint on the stored discriminants and return
-- the new list of expressions constraining the stored discriminants.
function Find_Type_Of_Object
(Obj_Def : Node_Id;
Related_Nod : Node_Id) return Entity_Id;
-- Get type entity for object referenced by Obj_Def, attaching the
-- implicit types generated to Related_Nod
procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Create a new float, and apply the constraint to obtain subtype of it
function Has_Range_Constraint (N : Node_Id) return Boolean;
-- Given an N_Subtype_Indication node N, return True if a range constraint
-- is present, either directly, or as part of a digits or delta constraint.
-- In addition, a digits constraint in the decimal case returns True, since
-- it establishes a default range if no explicit range is present.
function Is_Valid_Constraint_Kind
(T_Kind : Type_Kind;
Constraint_Kind : Node_Kind) return Boolean;
-- Returns True if it is legal to apply the given kind of constraint to the
-- given kind of type (index constraint to an array type, for example).
procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Create new modular type. Verify that modulus is in bounds and is
-- a power of two (implementation restriction).
procedure New_Concatenation_Op (Typ : Entity_Id);
-- Create an abbreviated declaration for an operator in order to
-- materialize concatenation on array types.
procedure Ordinary_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id);
-- Create a new ordinary fixed point type, and apply the constraint to
-- obtain subtype of it.
procedure Prepare_Private_Subtype_Completion
(Id : Entity_Id;
Related_Nod : Node_Id);
-- Id is a subtype of some private type. Creates the full declaration
-- associated with Id whenever possible, i.e. when the full declaration
-- of the base type is already known. Records each subtype into
-- Private_Dependents of the base type.
procedure Process_Incomplete_Dependents
(N : Node_Id;
Full_T : Entity_Id;
Inc_T : Entity_Id);
-- Process all entities that depend on an incomplete type. There include
-- subtypes, subprogram types that mention the incomplete type in their
-- profiles, and subprogram with access parameters that designate the
-- incomplete type.
-- Inc_T is the defining identifier of an incomplete type declaration, its
-- Ekind is E_Incomplete_Type.
--
-- N is the corresponding N_Full_Type_Declaration for Inc_T.
--
-- Full_T is N's defining identifier.
--
-- Subtypes of incomplete types with discriminants are completed when the
-- parent type is. This is simpler than private subtypes, because they can
-- only appear in the same scope, and there is no need to exchange views.
-- Similarly, access_to_subprogram types may have a parameter or a return
-- type that is an incomplete type, and that must be replaced with the
-- full type.
-- If the full type is tagged, subprogram with access parameters that
-- designated the incomplete may be primitive operations of the full type,
-- and have to be processed accordingly.
procedure Process_Real_Range_Specification (Def : Node_Id);
-- Given the type definition for a real type, this procedure processes
-- and checks the real range specification of this type definition if
-- one is present. If errors are found, error messages are posted, and
-- the Real_Range_Specification of Def is reset to Empty.
procedure Record_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Prev : Entity_Id);
-- Process a record type declaration (for both untagged and tagged
-- records). Parameters T and N are exactly like in procedure
-- Derived_Type_Declaration, except that no flag Is_Completion is needed
-- for this routine. If this is the completion of an incomplete type
-- declaration, Prev is the entity of the incomplete declaration, used for
-- cross-referencing. Otherwise Prev = T.
procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id);
-- This routine is used to process the actual record type definition
-- (both for untagged and tagged records). Def is a record type
-- definition node. This procedure analyzes the components in this
-- record type definition. Prev_T is the entity for the enclosing record
-- type. It is provided so that its Has_Task flag can be set if any of
-- the component have Has_Task set. If the declaration is the completion
-- of an incomplete type declaration, Prev_T is the original incomplete
-- type, whose full view is the record type.
procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id);
-- Subsidiary to Build_Derived_Record_Type. For untagged records, we
-- build a copy of the declaration tree of the parent, and we create
-- independently the list of components for the derived type. Semantic
-- information uses the component entities, but record representation
-- clauses are validated on the declaration tree. This procedure replaces
-- discriminants and components in the declaration with those that have
-- been created by Inherit_Components.
procedure Set_Fixed_Range
(E : Entity_Id;
Loc : Source_Ptr;
Lo : Ureal;
Hi : Ureal);
-- Build a range node with the given bounds and set it as the Scalar_Range
-- of the given fixed-point type entity. Loc is the source location used
-- for the constructed range. See body for further details.
procedure Set_Scalar_Range_For_Subtype
(Def_Id : Entity_Id;
R : Node_Id;
Subt : Entity_Id);
-- This routine is used to set the scalar range field for a subtype given
-- Def_Id, the entity for the subtype, and R, the range expression for the
-- scalar range. Subt provides the parent subtype to be used to analyze,
-- resolve, and check the given range.
procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Create a new signed integer entity, and apply the constraint to obtain
-- the required first named subtype of this type.
procedure Set_Stored_Constraint_From_Discriminant_Constraint
(E : Entity_Id);
-- E is some record type. This routine computes E's Stored_Constraint
-- from its Discriminant_Constraint.
-----------------------
-- Access_Definition --
-----------------------
function Access_Definition
(Related_Nod : Node_Id;
N : Node_Id) return Entity_Id
is
Anon_Type : Entity_Id;
Desig_Type : Entity_Id;
begin
if Is_Entry (Current_Scope)
and then Is_Task_Type (Etype (Scope (Current_Scope)))
then
Error_Msg_N ("task entries cannot have access parameters", N);
end if;
-- Ada 2005: for an object declaration the corresponding anonymous
-- type is declared in the current scope.
if Nkind (Related_Nod) = N_Object_Declaration then
Anon_Type :=
Create_Itype
(E_Anonymous_Access_Type, Related_Nod,
Scope_Id => Current_Scope);
-- For the anonymous function result case, retrieve the scope of
-- the function specification's associated entity rather than using
-- the current scope. The current scope will be the function itself
-- if the formal part is currently being analyzed, but will be the
-- parent scope in the case of a parameterless function, and we
-- always want to use the function's parent scope.
elsif Nkind (Related_Nod) = N_Function_Specification
and then Nkind (Parent (N)) /= N_Parameter_Specification
then
Anon_Type :=
Create_Itype
(E_Anonymous_Access_Type, Related_Nod,
Scope_Id => Scope (Defining_Unit_Name (Related_Nod)));
else
-- For access formals, access components, and access
-- discriminants, the scope is that of the enclosing declaration,
Anon_Type :=
Create_Itype
(E_Anonymous_Access_Type, Related_Nod,
Scope_Id => Scope (Current_Scope));
end if;
if All_Present (N)
and then Ada_Version >= Ada_05
then
Error_Msg_N ("ALL is not permitted for anonymous access types", N);
end if;
-- Ada 2005 (AI-254): In case of anonymous access to subprograms
-- call the corresponding semantic routine
if Present (Access_To_Subprogram_Definition (N)) then
Access_Subprogram_Declaration
(T_Name => Anon_Type,
T_Def => Access_To_Subprogram_Definition (N));
if Ekind (Anon_Type) = E_Access_Protected_Subprogram_Type then
Set_Ekind
(Anon_Type, E_Anonymous_Access_Protected_Subprogram_Type);
else
Set_Ekind
(Anon_Type, E_Anonymous_Access_Subprogram_Type);
end if;
return Anon_Type;
end if;
Find_Type (Subtype_Mark (N));
Desig_Type := Entity (Subtype_Mark (N));
Set_Directly_Designated_Type
(Anon_Type, Desig_Type);
Set_Etype (Anon_Type, Anon_Type);
Init_Size_Align (Anon_Type);
Set_Depends_On_Private (Anon_Type, Has_Private_Component (Anon_Type));
-- Ada 2005 (AI-231): Ada 2005 semantics for anonymous access differs
-- from Ada 95 semantics. In Ada 2005, anonymous access must specify
-- if the null value is allowed. In Ada 95 the null value is never
-- allowed.
if Ada_Version >= Ada_05 then
Set_Can_Never_Be_Null (Anon_Type, Null_Exclusion_Present (N));
else
Set_Can_Never_Be_Null (Anon_Type, True);
end if;
-- The anonymous access type is as public as the discriminated type or
-- subprogram that defines it. It is imported (for back-end purposes)
-- if the designated type is.
Set_Is_Public (Anon_Type, Is_Public (Scope (Anon_Type)));
-- Ada 2005 (AI-50217): Propagate the attribute that indicates that the
-- designated type comes from the limited view (for back-end purposes).
Set_From_With_Type (Anon_Type, From_With_Type (Desig_Type));
-- Ada 2005 (AI-231): Propagate the access-constant attribute
Set_Is_Access_Constant (Anon_Type, Constant_Present (N));
-- The context is either a subprogram declaration, object declaration,
-- or an access discriminant, in a private or a full type declaration.
-- In the case of a subprogram, if the designated type is incomplete,
-- the operation will be a primitive operation of the full type, to be
-- updated subsequently. If the type is imported through a limited_with
-- clause, the subprogram is not a primitive operation of the type
-- (which is declared elsewhere in some other scope).
if Ekind (Desig_Type) = E_Incomplete_Type
and then not From_With_Type (Desig_Type)
and then Is_Overloadable (Current_Scope)
then
Append_Elmt (Current_Scope, Private_Dependents (Desig_Type));
Set_Has_Delayed_Freeze (Current_Scope);
end if;
-- Ada 2005: if the designated type is an interface that may contain
-- tasks, create a Master entity for the declaration. This must be done
-- before expansion of the full declaration, because the declaration
-- may include an expression that is an allocator, whose expansion needs
-- the proper Master for the created tasks.
if Nkind (Related_Nod) = N_Object_Declaration
and then Expander_Active
and then Is_Interface (Desig_Type)
and then Is_Limited_Record (Desig_Type)
then
Build_Class_Wide_Master (Anon_Type);
end if;
return Anon_Type;
end Access_Definition;
-----------------------------------
-- Access_Subprogram_Declaration --
-----------------------------------
procedure Access_Subprogram_Declaration
(T_Name : Entity_Id;
T_Def : Node_Id)
is
Formals : constant List_Id := Parameter_Specifications (T_Def);
Formal : Entity_Id;
D_Ityp : Node_Id;
Desig_Type : constant Entity_Id :=
Create_Itype (E_Subprogram_Type, Parent (T_Def));
begin
-- Associate the Itype node with the inner full-type declaration
-- or subprogram spec. This is required to handle nested anonymous
-- declarations. For example:
-- procedure P
-- (X : access procedure
-- (Y : access procedure
-- (Z : access T)))
D_Ityp := Associated_Node_For_Itype (Desig_Type);
while Nkind (D_Ityp) /= N_Full_Type_Declaration
and then Nkind (D_Ityp) /= N_Procedure_Specification
and then Nkind (D_Ityp) /= N_Function_Specification
and then Nkind (D_Ityp) /= N_Object_Declaration
and then Nkind (D_Ityp) /= N_Object_Renaming_Declaration
and then Nkind (D_Ityp) /= N_Formal_Type_Declaration
loop
D_Ityp := Parent (D_Ityp);
pragma Assert (D_Ityp /= Empty);
end loop;
Set_Associated_Node_For_Itype (Desig_Type, D_Ityp);
if Nkind (D_Ityp) = N_Procedure_Specification
or else Nkind (D_Ityp) = N_Function_Specification
then
Set_Scope (Desig_Type, Scope (Defining_Unit_Name (D_Ityp)));
elsif Nkind (D_Ityp) = N_Full_Type_Declaration
or else Nkind (D_Ityp) = N_Object_Declaration
or else Nkind (D_Ityp) = N_Object_Renaming_Declaration
or else Nkind (D_Ityp) = N_Formal_Type_Declaration
then
Set_Scope (Desig_Type, Scope (Defining_Identifier (D_Ityp)));
end if;
if Nkind (T_Def) = N_Access_Function_Definition then
if Nkind (Result_Definition (T_Def)) = N_Access_Definition then
Set_Etype
(Desig_Type,
Access_Definition (T_Def, Result_Definition (T_Def)));
else
Analyze (Result_Definition (T_Def));
Set_Etype (Desig_Type, Entity (Result_Definition (T_Def)));
end if;
if not (Is_Type (Etype (Desig_Type))) then
Error_Msg_N
("expect type in function specification",
Result_Definition (T_Def));
end if;
else
Set_Etype (Desig_Type, Standard_Void_Type);
end if;
if Present (Formals) then
New_Scope (Desig_Type);
Process_Formals (Formals, Parent (T_Def));
-- A bit of a kludge here, End_Scope requires that the parent
-- pointer be set to something reasonable, but Itypes don't have
-- parent pointers. So we set it and then unset it ??? If and when
-- Itypes have proper parent pointers to their declarations, this
-- kludge can be removed.
Set_Parent (Desig_Type, T_Name);
End_Scope;
Set_Parent (Desig_Type, Empty);
end if;
-- The return type and/or any parameter type may be incomplete. Mark
-- the subprogram_type as depending on the incomplete type, so that
-- it can be updated when the full type declaration is seen.
if Present (Formals) then
Formal := First_Formal (Desig_Type);
while Present (Formal) loop
if Ekind (Formal) /= E_In_Parameter
and then Nkind (T_Def) = N_Access_Function_Definition
then
Error_Msg_N ("functions can only have IN parameters", Formal);
end if;
if Ekind (Etype (Formal)) = E_Incomplete_Type then
Append_Elmt (Desig_Type, Private_Dependents (Etype (Formal)));
Set_Has_Delayed_Freeze (Desig_Type);
end if;
Next_Formal (Formal);
end loop;
end if;
if Ekind (Etype (Desig_Type)) = E_Incomplete_Type
and then not Has_Delayed_Freeze (Desig_Type)
then
Append_Elmt (Desig_Type, Private_Dependents (Etype (Desig_Type)));
Set_Has_Delayed_Freeze (Desig_Type);
end if;
Check_Delayed_Subprogram (Desig_Type);
if Protected_Present (T_Def) then
Set_Ekind (T_Name, E_Access_Protected_Subprogram_Type);
Set_Convention (Desig_Type, Convention_Protected);
else
Set_Ekind (T_Name, E_Access_Subprogram_Type);
end if;
Set_Etype (T_Name, T_Name);
Init_Size_Align (T_Name);
Set_Directly_Designated_Type (T_Name, Desig_Type);
-- Ada 2005 (AI-231): Propagate the null-excluding attribute
Set_Can_Never_Be_Null (T_Name, Null_Exclusion_Present (T_Def));
Check_Restriction (No_Access_Subprograms, T_Def);
end Access_Subprogram_Declaration;
----------------------------
-- Access_Type_Declaration --
----------------------------
procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id) is
S : constant Node_Id := Subtype_Indication (Def);
P : constant Node_Id := Parent (Def);
Desig : Entity_Id;
-- Designated type
begin
-- Check for permissible use of incomplete type
if Nkind (S) /= N_Subtype_Indication then
Analyze (S);
if Ekind (Root_Type (Entity (S))) = E_Incomplete_Type then
Set_Directly_Designated_Type (T, Entity (S));
else
Set_Directly_Designated_Type (T,
Process_Subtype (S, P, T, 'P'));
end if;
else
Set_Directly_Designated_Type (T,
Process_Subtype (S, P, T, 'P'));
end if;
if All_Present (Def) or Constant_Present (Def) then
Set_Ekind (T, E_General_Access_Type);
else
Set_Ekind (T, E_Access_Type);
end if;
if Base_Type (Designated_Type (T)) = T then
Error_Msg_N ("access type cannot designate itself", S);
-- In Ada 2005, the type may have a limited view through some unit
-- in its own context, allowing the following circularity that cannot
-- be detected earlier
elsif Is_Class_Wide_Type (Designated_Type (T))
and then Etype (Designated_Type (T)) = T
then
Error_Msg_N
("access type cannot designate its own classwide type", S);
-- Clean up indication of tagged status to prevent cascaded errors
Set_Is_Tagged_Type (T, False);
end if;
Set_Etype (T, T);
-- If the type has appeared already in a with_type clause, it is
-- frozen and the pointer size is already set. Else, initialize.
if not From_With_Type (T) then
Init_Size_Align (T);
end if;
Set_Is_Access_Constant (T, Constant_Present (Def));
Desig := Designated_Type (T);
-- If designated type is an imported tagged type, indicate that the
-- access type is also imported, and therefore restricted in its use.
-- The access type may already be imported, so keep setting otherwise.
-- Ada 2005 (AI-50217): If the non-limited view of the designated type
-- is available, use it as the designated type of the access type, so
-- that the back-end gets a usable entity.
declare
N_Desig : Entity_Id;
begin
if From_With_Type (Desig)
and then Ekind (Desig) /= E_Access_Type
then
Set_From_With_Type (T);
if Ekind (Desig) = E_Incomplete_Type then
N_Desig := Non_Limited_View (Desig);
else pragma Assert (Ekind (Desig) = E_Class_Wide_Type);
if From_With_Type (Etype (Desig)) then
N_Desig := Non_Limited_View (Etype (Desig));
else
N_Desig := Etype (Desig);
end if;
end if;
pragma Assert (Present (N_Desig));
Set_Directly_Designated_Type (T, N_Desig);
end if;
end;
-- Note that Has_Task is always false, since the access type itself
-- is not a task type. See Einfo for more description on this point.
-- Exactly the same consideration applies to Has_Controlled_Component.
Set_Has_Task (T, False);
Set_Has_Controlled_Component (T, False);
-- Ada 2005 (AI-231): Propagate the null-excluding and access-constant
-- attributes
Set_Can_Never_Be_Null (T, Null_Exclusion_Present (Def));
Set_Is_Access_Constant (T, Constant_Present (Def));
end Access_Type_Declaration;
----------------------------------
-- Add_Interface_Tag_Components --
----------------------------------
procedure Add_Interface_Tag_Components
(N : Node_Id;
Typ : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Elmt : Elmt_Id;
Ext : Node_Id;
L : List_Id;
Last_Tag : Node_Id;
Comp : Node_Id;
procedure Add_Tag (Iface : Entity_Id);
-- Comment required ???
-------------
-- Add_Tag --
-------------
procedure Add_Tag (Iface : Entity_Id) is
Decl : Node_Id;
Def : Node_Id;
Tag : Entity_Id;
Offset : Entity_Id;
begin
pragma Assert (Is_Tagged_Type (Iface)
and then Is_Interface (Iface));
Def :=
Make_Component_Definition (Loc,
Aliased_Present => True,
Subtype_Indication =>
New_Occurrence_Of (RTE (RE_Interface_Tag), Loc));
Tag := Make_Defining_Identifier (Loc, New_Internal_Name ('V'));
Decl :=
Make_Component_Declaration (Loc,
Defining_Identifier => Tag,
Component_Definition => Def);
Analyze_Component_Declaration (Decl);
Set_Analyzed (Decl);
Set_Ekind (Tag, E_Component);
Set_Is_Limited_Record (Tag);
Set_Is_Tag (Tag);
Init_Component_Location (Tag);
pragma Assert (Is_Frozen (Iface));
Set_DT_Entry_Count (Tag,
DT_Entry_Count (First_Entity (Iface)));
if No (Last_Tag) then
Prepend (Decl, L);
else
Insert_After (Last_Tag, Decl);
end if;
Last_Tag := Decl;
-- If the ancestor has discriminants we need to give special support
-- to store the offset_to_top value of the secondary dispatch tables.
-- For this purpose we add a supplementary component just after the
-- field that contains the tag associated with each secondary DT.
if Typ /= Etype (Typ)
and then Has_Discriminants (Etype (Typ))
then
Def :=
Make_Component_Definition (Loc,
Subtype_Indication =>
New_Occurrence_Of (RTE (RE_Storage_Offset), Loc));
Offset :=
Make_Defining_Identifier (Loc, New_Internal_Name ('V'));
Decl :=
Make_Component_Declaration (Loc,
Defining_Identifier => Offset,
Component_Definition => Def);
Analyze_Component_Declaration (Decl);
Set_Analyzed (Decl);
Set_Ekind (Offset, E_Component);
Init_Component_Location (Offset);
Insert_After (Last_Tag, Decl);
Last_Tag := Decl;
end if;
end Add_Tag;
-- Start of processing for Add_Interface_Tag_Components
begin
if Ekind (Typ) /= E_Record_Type
or else No (Abstract_Interfaces (Typ))
or else Is_Empty_Elmt_List (Abstract_Interfaces (Typ))
or else not RTE_Available (RE_Interface_Tag)
then
return;
end if;
if Present (Abstract_Interfaces (Typ)) then
-- Find the current last tag
if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
Ext := Record_Extension_Part (Type_Definition (N));
else
pragma Assert (Nkind (Type_Definition (N)) = N_Record_Definition);
Ext := Type_Definition (N);
end if;
Last_Tag := Empty;
if not (Present (Component_List (Ext))) then
Set_Null_Present (Ext, False);
L := New_List;
Set_Component_List (Ext,
Make_Component_List (Loc,
Component_Items => L,
Null_Present => False));
else
if Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
L := Component_Items
(Component_List
(Record_Extension_Part
(Type_Definition (N))));
else
L := Component_Items
(Component_List
(Type_Definition (N)));
end if;
-- Find the last tag component
Comp := First (L);
while Present (Comp) loop
if Is_Tag (Defining_Identifier (Comp)) then
Last_Tag := Comp;
end if;
Next (Comp);
end loop;
end if;
-- At this point L references the list of components and Last_Tag
-- references the current last tag (if any). Now we add the tag
-- corresponding with all the interfaces that are not implemented
-- by the parent.
pragma Assert (Present
(First_Elmt (Abstract_Interfaces (Typ))));
Elmt := First_Elmt (Abstract_Interfaces (Typ));
while Present (Elmt) loop
Add_Tag (Node (Elmt));
Next_Elmt (Elmt);
end loop;
end if;
end Add_Interface_Tag_Components;
-----------------------------------
-- Analyze_Component_Declaration --
-----------------------------------
procedure Analyze_Component_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
P : Entity_Id;
function Contains_POC (Constr : Node_Id) return Boolean;
-- Determines whether a constraint uses the discriminant of a record
-- type thus becoming a per-object constraint (POC).
function Is_Known_Limited (Typ : Entity_Id) return Boolean;
-- Check whether enclosing record is limited, to validate declaration
-- of components with limited types.
-- This seems a wrong description to me???
-- What is Typ? For sure it can return a result without checking
-- the enclosing record (enclosing what???)
------------------
-- Contains_POC --
------------------
function Contains_POC (Constr : Node_Id) return Boolean is
begin
case Nkind (Constr) is
when N_Attribute_Reference =>
return Attribute_Name (Constr) = Name_Access
and
Prefix (Constr) = Scope (Entity (Prefix (Constr)));
when N_Discriminant_Association =>
return Denotes_Discriminant (Expression (Constr));
when N_Identifier =>
return Denotes_Discriminant (Constr);
when N_Index_Or_Discriminant_Constraint =>
declare
IDC : Node_Id;
begin
IDC := First (Constraints (Constr));
while Present (IDC) loop
-- One per-object constraint is sufficient
if Contains_POC (IDC) then
return True;
end if;
Next (IDC);
end loop;
return False;
end;
when N_Range =>
return Denotes_Discriminant (Low_Bound (Constr))
or else
Denotes_Discriminant (High_Bound (Constr));
when N_Range_Constraint =>
return Denotes_Discriminant (Range_Expression (Constr));
when others =>
return False;
end case;
end Contains_POC;
----------------------
-- Is_Known_Limited --
----------------------
function Is_Known_Limited (Typ : Entity_Id) return Boolean is
P : constant Entity_Id := Etype (Typ);
R : constant Entity_Id := Root_Type (Typ);
begin
if Is_Limited_Record (Typ) then
return True;
-- If the root type is limited (and not a limited interface)
-- so is the current type
elsif Is_Limited_Record (R)
and then
(not Is_Interface (R)
or else not Is_Limited_Interface (R))
then
return True;
-- Else the type may have a limited interface progenitor, but a
-- limited record parent.
elsif R /= P
and then Is_Limited_Record (P)
then
return True;
else
return False;
end if;
end Is_Known_Limited;
-- Start of processing for Analyze_Component_Declaration
begin
Generate_Definition (Id);
Enter_Name (Id);
if Present (Subtype_Indication (Component_Definition (N))) then
T := Find_Type_Of_Object
(Subtype_Indication (Component_Definition (N)), N);
-- Ada 2005 (AI-230): Access Definition case
else
pragma Assert (Present
(Access_Definition (Component_Definition (N))));
T := Access_Definition
(Related_Nod => N,
N => Access_Definition (Component_Definition (N)));
Set_Is_Local_Anonymous_Access (T);
-- Ada 2005 (AI-254)
if Present (Access_To_Subprogram_Definition
(Access_Definition (Component_Definition (N))))
and then Protected_Present (Access_To_Subprogram_Definition
(Access_Definition
(Component_Definition (N))))
then
T := Replace_Anonymous_Access_To_Protected_Subprogram (N, T);
end if;
end if;
-- If the subtype is a constrained subtype of the enclosing record,
-- (which must have a partial view) the back-end does not properly
-- handle the recursion. Rewrite the component declaration with an
-- explicit subtype indication, which is acceptable to Gigi. We can copy
-- the tree directly because side effects have already been removed from
-- discriminant constraints.
if Ekind (T) = E_Access_Subtype
and then Is_Entity_Name (Subtype_Indication (Component_Definition (N)))
and then Comes_From_Source (T)
and then Nkind (Parent (T)) = N_Subtype_Declaration
and then Etype (Directly_Designated_Type (T)) = Current_Scope
then
Rewrite
(Subtype_Indication (Component_Definition (N)),
New_Copy_Tree (Subtype_Indication (Parent (T))));
T := Find_Type_Of_Object
(Subtype_Indication (Component_Definition (N)), N);
end if;
-- If the component declaration includes a default expression, then we
-- check that the component is not of a limited type (RM 3.7(5)),
-- and do the special preanalysis of the expression (see section on
-- "Handling of Default and Per-Object Expressions" in the spec of
-- package Sem).
if Present (Expression (N)) then
Analyze_Per_Use_Expression (Expression (N), T);
Check_Initialization (T, Expression (N));
if Ada_Version >= Ada_05
and then Is_Access_Type (T)
and then Ekind (T) = E_Anonymous_Access_Type
then
-- Check RM 3.9.2(9): "if the expected type for an expression is
-- an anonymous access-to-specific tagged type, then the object
-- designated by the expression shall not be dynamically tagged
-- unless it is a controlling operand in a call on a dispatching
-- operation"
if Is_Tagged_Type (Directly_Designated_Type (T))
and then
Ekind (Directly_Designated_Type (T)) /= E_Class_Wide_Type
and then
Ekind (Directly_Designated_Type (Etype (Expression (N)))) =
E_Class_Wide_Type
then
Error_Msg_N
("access to specific tagged type required ('R'M 3.9.2(9))",
Expression (N));
end if;
-- (Ada 2005: AI-230): Accessibility check for anonymous
-- components
if Type_Access_Level (Etype (Expression (N))) >
Type_Access_Level (T)
then
Error_Msg_N
("expression has deeper access level than component " &
"('R'M 3.10.2 (12.2))", Expression (N));
end if;
end if;
end if;
-- The parent type may be a private view with unknown discriminants,
-- and thus unconstrained. Regular components must be constrained.
if Is_Indefinite_Subtype (T) and then Chars (Id) /= Name_uParent then
if Is_Class_Wide_Type (T) then
Error_Msg_N
("class-wide subtype with unknown discriminants" &
" in component declaration",
Subtype_Indication (Component_Definition (N)));
else
Error_Msg_N
("unconstrained subtype in component declaration",
Subtype_Indication (Component_Definition (N)));
end if;
-- Components cannot be abstract, except for the special case of
-- the _Parent field (case of extending an abstract tagged type)
elsif Is_Abstract (T) and then Chars (Id) /= Name_uParent then
Error_Msg_N ("type of a component cannot be abstract", N);
end if;
Set_Etype (Id, T);
Set_Is_Aliased (Id, Aliased_Present (Component_Definition (N)));
-- The component declaration may have a per-object constraint, set
-- the appropriate flag in the defining identifier of the subtype.
if Present (Subtype_Indication (Component_Definition (N))) then
declare
Sindic : constant Node_Id :=
Subtype_Indication (Component_Definition (N));
begin
if Nkind (Sindic) = N_Subtype_Indication
and then Present (Constraint (Sindic))
and then Contains_POC (Constraint (Sindic))
then
Set_Has_Per_Object_Constraint (Id);
end if;
end;
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
-- out some static checks.
if Ada_Version >= Ada_05
and then Can_Never_Be_Null (T)
then
Null_Exclusion_Static_Checks (N);
end if;
-- If this component is private (or depends on a private type), flag the
-- record type to indicate that some operations are not available.
P := Private_Component (T);
if Present (P) then
-- Check for circular definitions
if P = Any_Type then
Set_Etype (Id, Any_Type);
-- There is a gap in the visibility of operations only if the
-- component type is not defined in the scope of the record type.
elsif Scope (P) = Scope (Current_Scope) then
null;
elsif Is_Limited_Type (P) then
Set_Is_Limited_Composite (Current_Scope);
else
Set_Is_Private_Composite (Current_Scope);
end if;
end if;
if P /= Any_Type
and then Is_Limited_Type (T)
and then Chars (Id) /= Name_uParent
and then Is_Tagged_Type (Current_Scope)
then
if Is_Derived_Type (Current_Scope)
and then not Is_Known_Limited (Current_Scope)
then
Error_Msg_N
("extension of nonlimited type cannot have limited components",
N);
if Is_Interface (Root_Type (Current_Scope)) then
Error_Msg_N
("\limitedness is not inherited from limited interface", N);
Error_Msg_N
("\add LIMITED to type indication", N);
end if;
Explain_Limited_Type (T, N);
Set_Etype (Id, Any_Type);
Set_Is_Limited_Composite (Current_Scope, False);
elsif not Is_Derived_Type (Current_Scope)
and then not Is_Limited_Record (Current_Scope)
and then not Is_Concurrent_Type (Current_Scope)
then
Error_Msg_N
("nonlimited tagged type cannot have limited components", N);
Explain_Limited_Type (T, N);
Set_Etype (Id, Any_Type);
Set_Is_Limited_Composite (Current_Scope, False);
end if;
end if;
Set_Original_Record_Component (Id, Id);
end Analyze_Component_Declaration;
--------------------------
-- Analyze_Declarations --
--------------------------
procedure Analyze_Declarations (L : List_Id) is
D : Node_Id;
Next_Node : Node_Id;
Freeze_From : Entity_Id := Empty;
procedure Adjust_D;
-- Adjust D not to include implicit label declarations, since these
-- have strange Sloc values that result in elaboration check problems.
-- (They have the sloc of the label as found in the source, and that
-- is ahead of the current declarative part).
--------------
-- Adjust_D --
--------------
procedure Adjust_D is
begin
while Present (Prev (D))
and then Nkind (D) = N_Implicit_Label_Declaration
loop
Prev (D);
end loop;
end Adjust_D;
-- Start of processing for Analyze_Declarations
begin
D := First (L);
while Present (D) loop
-- Complete analysis of declaration
Analyze (D);
Next_Node := Next (D);
if No (Freeze_From) then
Freeze_From := First_Entity (Current_Scope);
end if;
-- At the end of a declarative part, freeze remaining entities
-- declared in it. The end of the visible declarations of package
-- specification is not the end of a declarative part if private
-- declarations are present. The end of a package declaration is a
-- freezing point only if it a library package. A task definition or
-- protected type definition is not a freeze point either. Finally,
-- we do not freeze entities in generic scopes, because there is no
-- code generated for them and freeze nodes will be generated for
-- the instance.
-- The end of a package instantiation is not a freeze point, but
-- for now we make it one, because the generic body is inserted
-- (currently) immediately after. Generic instantiations will not
-- be a freeze point once delayed freezing of bodies is implemented.
-- (This is needed in any case for early instantiations ???).
if No (Next_Node) then
if Nkind (Parent (L)) = N_Component_List
or else Nkind (Parent (L)) = N_Task_Definition
or else Nkind (Parent (L)) = N_Protected_Definition
then
null;
elsif Nkind (Parent (L)) /= N_Package_Specification then
if Nkind (Parent (L)) = N_Package_Body then
Freeze_From := First_Entity (Current_Scope);
end if;
Adjust_D;
Freeze_All (Freeze_From, D);
Freeze_From := Last_Entity (Current_Scope);
elsif Scope (Current_Scope) /= Standard_Standard
and then not Is_Child_Unit (Current_Scope)
and then No (Generic_Parent (Parent (L)))
then
null;
elsif L /= Visible_Declarations (Parent (L))
or else No (Private_Declarations (Parent (L)))
or else Is_Empty_List (Private_Declarations (Parent (L)))
then
Adjust_D;
Freeze_All (Freeze_From, D);
Freeze_From := Last_Entity (Current_Scope);
end if;
-- If next node is a body then freeze all types before the body.
-- An exception occurs for expander generated bodies, which can
-- be recognized by their already being analyzed. The expander
-- ensures that all types needed by these bodies have been frozen
-- but it is not necessary to freeze all types (and would be wrong
-- since it would not correspond to an RM defined freeze point).
elsif not Analyzed (Next_Node)
and then (Nkind (Next_Node) = N_Subprogram_Body
or else Nkind (Next_Node) = N_Entry_Body
or else Nkind (Next_Node) = N_Package_Body
or else Nkind (Next_Node) = N_Protected_Body
or else Nkind (Next_Node) = N_Task_Body
or else Nkind (Next_Node) in N_Body_Stub)
then
Adjust_D;
Freeze_All (Freeze_From, D);
Freeze_From := Last_Entity (Current_Scope);
end if;
D := Next_Node;
end loop;
end Analyze_Declarations;
----------------------------------
-- Analyze_Incomplete_Type_Decl --
----------------------------------
procedure Analyze_Incomplete_Type_Decl (N : Node_Id) is
F : constant Boolean := Is_Pure (Current_Scope);
T : Entity_Id;
begin
Generate_Definition (Defining_Identifier (N));
-- Process an incomplete declaration. The identifier must not have been
-- declared already in the scope. However, an incomplete declaration may
-- appear in the private part of a package, for a private type that has
-- already been declared.
-- In this case, the discriminants (if any) must match
T := Find_Type_Name (N);
Set_Ekind (T, E_Incomplete_Type);
Init_Size_Align (T);
Set_Is_First_Subtype (T, True);
Set_Etype (T, T);
-- Ada 2005 (AI-326): Minimum decoration to give support to tagged
-- incomplete types.
if Tagged_Present (N) then
Set_Is_Tagged_Type (T);
Make_Class_Wide_Type (T);
Set_Primitive_Operations (T, New_Elmt_List);
end if;
New_Scope (T);
Set_Stored_Constraint (T, No_Elist);
if Present (Discriminant_Specifications (N)) then
Process_Discriminants (N);
end if;
End_Scope;
-- If the type has discriminants, non-trivial subtypes may be be
-- declared before the full view of the type. The full views of those
-- subtypes will be built after the full view of the type.
Set_Private_Dependents (T, New_Elmt_List);
Set_Is_Pure (T, F);
end Analyze_Incomplete_Type_Decl;
-----------------------------------
-- Analyze_Interface_Declaration --
-----------------------------------
procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id) is
begin
Set_Is_Tagged_Type (T);
Set_Is_Limited_Record (T, Limited_Present (Def)
or else Task_Present (Def)
or else Protected_Present (Def)
or else Synchronized_Present (Def));
-- Type is abstract if full declaration carries keyword, or if
-- previous partial view did.
Set_Is_Abstract (T);
Set_Is_Interface (T);
Set_Is_Limited_Interface (T, Limited_Present (Def));
Set_Is_Protected_Interface (T, Protected_Present (Def));
Set_Is_Synchronized_Interface (T, Synchronized_Present (Def));
Set_Is_Task_Interface (T, Task_Present (Def));
Set_Abstract_Interfaces (T, New_Elmt_List);
Set_Primitive_Operations (T, New_Elmt_List);
end Analyze_Interface_Declaration;
-----------------------------
-- Analyze_Itype_Reference --
-----------------------------
-- Nothing to do. This node is placed in the tree only for the benefit of
-- back end processing, and has no effect on the semantic processing.
procedure Analyze_Itype_Reference (N : Node_Id) is
begin
pragma Assert (Is_Itype (Itype (N)));
null;
end Analyze_Itype_Reference;
--------------------------------
-- Analyze_Number_Declaration --
--------------------------------
procedure Analyze_Number_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
E : constant Node_Id := Expression (N);
T : Entity_Id;
Index : Interp_Index;
It : Interp;
begin
Generate_Definition (Id);
Enter_Name (Id);
-- This is an optimization of a common case of an integer literal
if Nkind (E) = N_Integer_Literal then
Set_Is_Static_Expression (E, True);
Set_Etype (E, Universal_Integer);
Set_Etype (Id, Universal_Integer);
Set_Ekind (Id, E_Named_Integer);
Set_Is_Frozen (Id, True);
return;
end if;
Set_Is_Pure (Id, Is_Pure (Current_Scope));
-- Process expression, replacing error by integer zero, to avoid
-- cascaded errors or aborts further along in the processing
-- Replace Error by integer zero, which seems least likely to
-- cause cascaded errors.
if E = Error then
Rewrite (E, Make_Integer_Literal (Sloc (E), Uint_0));
Set_Error_Posted (E);
end if;
Analyze (E);
-- Verify that the expression is static and numeric. If
-- the expression is overloaded, we apply the preference
-- rule that favors root numeric types.
if not Is_Overloaded (E) then
T := Etype (E);
else
T := Any_Type;
Get_First_Interp (E, Index, It);
while Present (It.Typ) loop
if (Is_Integer_Type (It.Typ)
or else Is_Real_Type (It.Typ))
and then (Scope (Base_Type (It.Typ))) = Standard_Standard
then
if T = Any_Type then
T := It.Typ;
elsif It.Typ = Universal_Real
or else It.Typ = Universal_Integer
then
-- Choose universal interpretation over any other
T := It.Typ;
exit;
end if;
end if;
Get_Next_Interp (Index, It);
end loop;
end if;
if Is_Integer_Type (T) then
Resolve (E, T);
Set_Etype (Id, Universal_Integer);
Set_Ekind (Id, E_Named_Integer);
elsif Is_Real_Type (T) then
-- Because the real value is converted to universal_real, this is a
-- legal context for a universal fixed expression.
if T = Universal_Fixed then
declare
Loc : constant Source_Ptr := Sloc (N);
Conv : constant Node_Id := Make_Type_Conversion (Loc,
Subtype_Mark =>
New_Occurrence_Of (Universal_Real, Loc),
Expression => Relocate_Node (E));
begin
Rewrite (E, Conv);
Analyze (E);
end;
elsif T = Any_Fixed then
Error_Msg_N ("illegal context for mixed mode operation", E);
-- Expression is of the form : universal_fixed * integer. Try to
-- resolve as universal_real.
T := Universal_Real;
Set_Etype (E, T);
end if;
Resolve (E, T);
Set_Etype (Id, Universal_Real);
Set_Ekind (Id, E_Named_Real);
else
Wrong_Type (E, Any_Numeric);
Resolve (E, T);
Set_Etype (Id, T);
Set_Ekind (Id, E_Constant);
Set_Never_Set_In_Source (Id, True);
Set_Is_True_Constant (Id, True);
return;
end if;
if Nkind (E) = N_Integer_Literal
or else Nkind (E) = N_Real_Literal
then
Set_Etype (E, Etype (Id));
end if;
if not Is_OK_Static_Expression (E) then
Flag_Non_Static_Expr
("non-static expression used in number declaration!", E);
Rewrite (E, Make_Integer_Literal (Sloc (N), 1));
Set_Etype (E, Any_Type);
end if;
end Analyze_Number_Declaration;
--------------------------------
-- Analyze_Object_Declaration --
--------------------------------
procedure Analyze_Object_Declaration (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
Act_T : Entity_Id;
E : Node_Id := Expression (N);
-- E is set to Expression (N) throughout this routine. When
-- Expression (N) is modified, E is changed accordingly.
Prev_Entity : Entity_Id := Empty;
function Build_Default_Subtype return Entity_Id;
-- If the object is limited or aliased, and if the type is unconstrained
-- and there is no expression, the discriminants cannot be modified and
-- the subtype of the object is constrained by the defaults, so it is
-- worthwhile building the corresponding subtype.
function Count_Tasks (T : Entity_Id) return Uint;
-- This function is called when a library level object of type is
-- declared. It's function is to count the static number of tasks
-- declared within the type (it is only called if Has_Tasks is set for
-- T). As a side effect, if an array of tasks with non-static bounds or
-- a variant record type is encountered, Check_Restrictions is called
-- indicating the count is unknown.
---------------------------
-- Build_Default_Subtype --
---------------------------
function Build_Default_Subtype return Entity_Id is
Constraints : constant List_Id := New_List;
Act : Entity_Id;
Decl : Node_Id;
Disc : Entity_Id;
begin
Disc := First_Discriminant (T);
if No (Discriminant_Default_Value (Disc)) then
return T; -- previous error.
end if;
Act := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
while Present (Disc) loop
Append (
New_Copy_Tree (
Discriminant_Default_Value (Disc)), Constraints);
Next_Discriminant (Disc);
end loop;
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Act,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (T, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint
(Loc, Constraints)));
Insert_Before (N, Decl);
Analyze (Decl);
return Act;
end Build_Default_Subtype;
-----------------
-- Count_Tasks --
-----------------
function Count_Tasks (T : Entity_Id) return Uint is
C : Entity_Id;
X : Node_Id;
V : Uint;
begin
if Is_Task_Type (T) then
return Uint_1;
elsif Is_Record_Type (T) then
if Has_Discriminants (T) then
Check_Restriction (Max_Tasks, N);
return Uint_0;
else
V := Uint_0;
C := First_Component (T);
while Present (C) loop
V := V + Count_Tasks (Etype (C));
Next_Component (C);
end loop;
return V;
end if;
elsif Is_Array_Type (T) then
X := First_Index (T);
V := Count_Tasks (Component_Type (T));
while Present (X) loop
C := Etype (X);
if not Is_Static_Subtype (C) then
Check_Restriction (Max_Tasks, N);
return Uint_0;
else
V := V * (UI_Max (Uint_0,
Expr_Value (Type_High_Bound (C)) -
Expr_Value (Type_Low_Bound (C)) + Uint_1));
end if;
Next_Index (X);
end loop;
return V;
else
return Uint_0;
end if;
end Count_Tasks;
-- Start of processing for Analyze_Object_Declaration
begin
-- There are three kinds of implicit types generated by an
-- object declaration:
-- 1. Those for generated by the original Object Definition
-- 2. Those generated by the Expression
-- 3. Those used to constrained the Object Definition with the
-- expression constraints when it is unconstrained
-- They must be generated in this order to avoid order of elaboration
-- issues. Thus the first step (after entering the name) is to analyze
-- the object definition.
if Constant_Present (N) then
Prev_Entity := Current_Entity_In_Scope (Id);
-- If homograph is an implicit subprogram, it is overridden by the
-- current declaration.
if Present (Prev_Entity)
and then Is_Overloadable (Prev_Entity)
and then Is_Inherited_Operation (Prev_Entity)
then
Prev_Entity := Empty;
end if;
end if;
if Present (Prev_Entity) then
Constant_Redeclaration (Id, N, T);
Generate_Reference (Prev_Entity, Id, 'c');
Set_Completion_Referenced (Id);
if Error_Posted (N) then
-- Type mismatch or illegal redeclaration, Do not analyze
-- expression to avoid cascaded errors.
T := Find_Type_Of_Object (Object_Definition (N), N);
Set_Etype (Id, T);
Set_Ekind (Id, E_Variable);
return;
end if;
-- In the normal case, enter identifier at the start to catch premature
-- usage in the initialization expression.
else
Generate_Definition (Id);
Enter_Name (Id);
T := Find_Type_Of_Object (Object_Definition (N), N);
if Error_Posted (Id) then
Set_Etype (Id, T);
Set_Ekind (Id, E_Variable);
return;
end if;
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding attribute and carry
-- out some static checks
if Ada_Version >= Ada_05
and then Can_Never_Be_Null (T)
then
-- In case of aggregates we must also take care of the correct
-- initialization of nested aggregates bug this is done at the
-- point of the analysis of the aggregate (see sem_aggr.adb)
if Present (Expression (N))
and then Nkind (Expression (N)) = N_Aggregate
then
null;
else
declare
Save_Typ : constant Entity_Id := Etype (Id);
begin
Set_Etype (Id, T); -- Temp. decoration for static checks
Null_Exclusion_Static_Checks (N);
Set_Etype (Id, Save_Typ);
end;
end if;
end if;
Set_Is_Pure (Id, Is_Pure (Current_Scope));
-- If deferred constant, make sure context is appropriate. We detect
-- a deferred constant as a constant declaration with no expression.
-- A deferred constant can appear in a package body if its completion
-- is by means of an interface pragma.
if Constant_Present (N)
and then No (E)
then
if not Is_Package_Or_Generic_Package (Current_Scope) then
Error_Msg_N
("invalid context for deferred constant declaration ('R'M 7.4)",
N);
Error_Msg_N
("\declaration requires an initialization expression",
N);
Set_Constant_Present (N, False);
-- In Ada 83, deferred constant must be of private type
elsif not Is_Private_Type (T) then
if Ada_Version = Ada_83 and then Comes_From_Source (N) then
Error_Msg_N
("(Ada 83) deferred constant must be private type", N);
end if;
end if;
-- If not a deferred constant, then object declaration freezes its type
else
Check_Fully_Declared (T, N);
Freeze_Before (N, T);
end if;
-- If the object was created by a constrained array definition, then
-- set the link in both the anonymous base type and anonymous subtype
-- that are built to represent the array type to point to the object.
if Nkind (Object_Definition (Declaration_Node (Id))) =
N_Constrained_Array_Definition
then
Set_Related_Array_Object (T, Id);
Set_Related_Array_Object (Base_Type (T), Id);
end if;
-- Special checks for protected objects not at library level
if Is_Protected_Type (T)
and then not Is_Library_Level_Entity (Id)
then
Check_Restriction (No_Local_Protected_Objects, Id);
-- Protected objects with interrupt handlers must be at library level
-- Ada 2005: this test is not needed (and the corresponding clause
-- in the RM is removed) because accessibility checks are sufficient
-- to make handlers not at the library level illegal.
if Has_Interrupt_Handler (T)
and then Ada_Version < Ada_05
then
Error_Msg_N
("interrupt object can only be declared at library level", Id);
end if;
end if;
-- The actual subtype of the object is the nominal subtype, unless
-- the nominal one is unconstrained and obtained from the expression.
Act_T := T;
-- Process initialization expression if present and not in error
if Present (E) and then E /= Error then
Analyze (E);
-- In case of errors detected in the analysis of the expression,
-- decorate it with the expected type to avoid cascade errors
if No (Etype (E)) then
Set_Etype (E, T);
end if;
-- If an initialization expression is present, then we set the
-- Is_True_Constant flag. It will be reset if this is a variable
-- and it is indeed modified.
Set_Is_True_Constant (Id, True);
-- If we are analyzing a constant declaration, set its completion
-- flag after analyzing the expression.
if Constant_Present (N) then
Set_Has_Completion (Id);
end if;
if not Assignment_OK (N) then
Check_Initialization (T, E);
end if;
Set_Etype (Id, T); -- may be overridden later on
Resolve (E, T);
Check_Unset_Reference (E);
if Compile_Time_Known_Value (E) then
Set_Current_Value (Id, E);
end if;
-- Check incorrect use of dynamically tagged expressions. Note
-- the use of Is_Tagged_Type (T) which seems redundant but is in
-- fact important to avoid spurious errors due to expanded code
-- for dispatching functions over an anonymous access type
if (Is_Class_Wide_Type (Etype (E)) or else Is_Dynamically_Tagged (E))
and then Is_Tagged_Type (T)
and then not Is_Class_Wide_Type (T)
then
Error_Msg_N ("dynamically tagged expression not allowed!", E);
end if;
Apply_Scalar_Range_Check (E, T);
Apply_Static_Length_Check (E, T);
end if;
-- If the No_Streams restriction is set, check that the type of the
-- object is not, and does not contain, any subtype derived from
-- Ada.Streams.Root_Stream_Type. Note that we guard the call to
-- Has_Stream just for efficiency reasons. There is no point in
-- spending time on a Has_Stream check if the restriction is not set.
if Restrictions.Set (No_Streams) then
if Has_Stream (T) then
Check_Restriction (No_Streams, N);
end if;
end if;
-- Abstract type is never permitted for a variable or constant.
-- Note: we inhibit this check for objects that do not come from
-- source because there is at least one case (the expansion of
-- x'class'input where x is abstract) where we legitimately
-- generate an abstract object.
if Is_Abstract (T) and then Comes_From_Source (N) then
Error_Msg_N ("type of object cannot be abstract",
Object_Definition (N));
if Is_CPP_Class (T) then
Error_Msg_NE ("\} may need a cpp_constructor",
Object_Definition (N), T);
end if;
-- Case of unconstrained type
elsif Is_Indefinite_Subtype (T) then
-- Nothing to do in deferred constant case
if Constant_Present (N) and then No (E) then
null;
-- Case of no initialization present
elsif No (E) then
if No_Initialization (N) then
null;
elsif Is_Class_Wide_Type (T) then
Error_Msg_N
("initialization required in class-wide declaration ", N);
else
Error_Msg_N
("unconstrained subtype not allowed (need initialization)",
Object_Definition (N));
end if;
-- Case of initialization present but in error. Set initial
-- expression as absent (but do not make above complaints)
elsif E = Error then
Set_Expression (N, Empty);
E := Empty;
-- Case of initialization present
else
-- Not allowed in Ada 83
if not Constant_Present (N) then
if Ada_Version = Ada_83
and then Comes_From_Source (Object_Definition (N))
then
Error_Msg_N
("(Ada 83) unconstrained variable not allowed",
Object_Definition (N));
end if;
end if;
-- Now we constrain the variable from the initializing expression
-- If the expression is an aggregate, it has been expanded into
-- individual assignments. Retrieve the actual type from the
-- expanded construct.
if Is_Array_Type (T)
and then No_Initialization (N)
and then Nkind (Original_Node (E)) = N_Aggregate
then
Act_T := Etype (E);
else
Expand_Subtype_From_Expr (N, T, Object_Definition (N), E);
Act_T := Find_Type_Of_Object (Object_Definition (N), N);
end if;
Set_Is_Constr_Subt_For_U_Nominal (Act_T);
if Aliased_Present (N) then
Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
end if;
Freeze_Before (N, Act_T);
Freeze_Before (N, T);
end if;
elsif Is_Array_Type (T)
and then No_Initialization (N)
and then Nkind (Original_Node (E)) = N_Aggregate
then
if not Is_Entity_Name (Object_Definition (N)) then
Act_T := Etype (E);
Check_Compile_Time_Size (Act_T);
if Aliased_Present (N) then
Set_Is_Constr_Subt_For_UN_Aliased (Act_T);
end if;
end if;
-- When the given object definition and the aggregate are specified
-- independently, and their lengths might differ do a length check.
-- This cannot happen if the aggregate is of the form (others =>...)
if not Is_Constrained (T) then
null;
elsif Nkind (E) = N_Raise_Constraint_Error then
-- Aggregate is statically illegal. Place back in declaration
Set_Expression (N, E);
Set_No_Initialization (N, False);
elsif T = Etype (E) then
null;
elsif Nkind (E) = N_Aggregate
and then Present (Component_Associations (E))
and then Present (Choices (First (Component_Associations (E))))
and then Nkind (First
(Choices (First (Component_Associations (E))))) = N_Others_Choice
then
null;
else
Apply_Length_Check (E, T);
end if;
elsif (Is_Limited_Record (T)
or else Is_Concurrent_Type (T))
and then not Is_Constrained (T)
and then Has_Discriminants (T)
then
if No (E) then
Act_T := Build_Default_Subtype;
else
-- Ada 2005: a limited object may be initialized by means of an
-- aggregate. If the type has default discriminants it has an
-- unconstrained nominal type, Its actual subtype will be obtained
-- from the aggregate, and not from the default discriminants.
Act_T := Etype (E);
end if;
Rewrite (Object_Definition (N), New_Occurrence_Of (Act_T, Loc));
elsif Present (Underlying_Type (T))
and then not Is_Constrained (Underlying_Type (T))
and then Has_Discriminants (Underlying_Type (T))
and then Nkind (E) = N_Function_Call
and then Constant_Present (N)
then
-- The back-end has problems with constants of a discriminated type
-- with defaults, if the initial value is a function call. We
-- generate an intermediate temporary for the result of the call.
-- It is unclear why this should make it acceptable to gcc. ???
Remove_Side_Effects (E);
end if;
if T = Standard_Wide_Character or else T = Standard_Wide_Wide_Character
or else Root_Type (T) = Standard_Wide_String
or else Root_Type (T) = Standard_Wide_Wide_String
then
Check_Restriction (No_Wide_Characters, Object_Definition (N));
end if;
-- Now establish the proper kind and type of the object
if Constant_Present (N) then
Set_Ekind (Id, E_Constant);
Set_Never_Set_In_Source (Id, True);
Set_Is_True_Constant (Id, True);
else
Set_Ekind (Id, E_Variable);
-- A variable is set as shared passive if it appears in a shared
-- passive package, and is at the outer level. This is not done
-- for entities generated during expansion, because those are
-- always manipulated locally.
if Is_Shared_Passive (Current_Scope)
and then Is_Library_Level_Entity (Id)
and then Comes_From_Source (Id)
then
Set_Is_Shared_Passive (Id);
Check_Shared_Var (Id, T, N);
end if;
-- Case of no initializing expression present. If the type is not
-- fully initialized, then we set Never_Set_In_Source, since this
-- is a case of a potentially uninitialized object. Note that we
-- do not consider access variables to be fully initialized for
-- this purpose, since it still seems dubious if someone declares
-- Note that we only do this for source declarations. If the object
-- is declared by a generated declaration, we assume that it is not
-- appropriate to generate warnings in that case.
if No (E) then
if (Is_Access_Type (T)
or else not Is_Fully_Initialized_Type (T))
and then Comes_From_Source (N)
then
Set_Never_Set_In_Source (Id);
end if;
end if;
end if;
Init_Alignment (Id);
Init_Esize (Id);
if Aliased_Present (N) then
Set_Is_Aliased (Id);
if No (E)
and then Is_Record_Type (T)
and then not Is_Constrained (T)
and then Has_Discriminants (T)
then
Set_Actual_Subtype (Id, Build_Default_Subtype);
end if;
end if;
Set_Etype (Id, Act_T);
if Has_Controlled_Component (Etype (Id))
or else Is_Controlled (Etype (Id))
then
if not Is_Library_Level_Entity (Id) then
Check_Restriction (No_Nested_Finalization, N);
else
Validate_Controlled_Object (Id);
end if;
-- Generate a warning when an initialization causes an obvious ABE
-- violation. If the init expression is a simple aggregate there
-- shouldn't be any initialize/adjust call generated. This will be
-- true as soon as aggregates are built in place when possible.
-- ??? at the moment we do not generate warnings for temporaries
-- created for those aggregates although Program_Error might be
-- generated if compiled with -gnato.
if Is_Controlled (Etype (Id))
and then Comes_From_Source (Id)
then
declare
BT : constant Entity_Id := Base_Type (Etype (Id));
Implicit_Call : Entity_Id;
pragma Warnings (Off, Implicit_Call);
-- ??? what is this for (never referenced!)
function Is_Aggr (N : Node_Id) return Boolean;
-- Check that N is an aggregate
-------------
-- Is_Aggr --
-------------
function Is_Aggr (N : Node_Id) return Boolean is
begin
case Nkind (Original_Node (N)) is
when N_Aggregate | N_Extension_Aggregate =>
return True;
when N_Qualified_Expression |
N_Type_Conversion |
N_Unchecked_Type_Conversion =>
return Is_Aggr (Expression (Original_Node (N)));
when others =>
return False;
end case;
end Is_Aggr;
begin
-- If no underlying type, we already are in an error situation.
-- Do not try to add a warning since we do not have access to
-- prim-op list.
if No (Underlying_Type (BT)) then
Implicit_Call := Empty;
-- A generic type does not have usable primitive operators.
-- Initialization calls are built for instances.
elsif Is_Generic_Type (BT) then
Implicit_Call := Empty;
-- If the init expression is not an aggregate, an adjust call
-- will be generated
elsif Present (E) and then not Is_Aggr (E) then
Implicit_Call := Find_Prim_Op (BT, Name_Adjust);
-- If no init expression and we are not in the deferred
-- constant case, an Initialize call will be generated
elsif No (E) and then not Constant_Present (N) then
Implicit_Call := Find_Prim_Op (BT, Name_Initialize);
else
Implicit_Call := Empty;
end if;
end;
end if;
end if;
if Has_Task (Etype (Id)) then
Check_Restriction (No_Tasking, N);
if Is_Library_Level_Entity (Id) then
Check_Restriction (Max_Tasks, N, Count_Tasks (Etype (Id)));
else
Check_Restriction (Max_Tasks, N);
Check_Restriction (No_Task_Hierarchy, N);
Check_Potentially_Blocking_Operation (N);
end if;
-- A rather specialized test. If we see two tasks being declared
-- of the same type in the same object declaration, and the task
-- has an entry with an address clause, we know that program error
-- will be raised at run-time since we can't have two tasks with
-- entries at the same address.
if Is_Task_Type (Etype (Id)) and then More_Ids (N) then
declare
E : Entity_Id;
begin
E := First_Entity (Etype (Id));
while Present (E) loop
if Ekind (E) = E_Entry
and then Present (Get_Attribute_Definition_Clause
(E, Attribute_Address))
then
Error_Msg_N
("?more than one task with same entry address", N);
Error_Msg_N
("\?Program_Error will be raised at run time", N);
Insert_Action (N,
Make_Raise_Program_Error (Loc,
Reason => PE_Duplicated_Entry_Address));
exit;
end if;
Next_Entity (E);
end loop;
end;
end if;
end if;
-- Some simple constant-propagation: if the expression is a constant
-- string initialized with a literal, share the literal. This avoids
-- a run-time copy.
if Present (E)
and then Is_Entity_Name (E)
and then Ekind (Entity (E)) = E_Constant
and then Base_Type (Etype (E)) = Standard_String
then
declare
Val : constant Node_Id := Constant_Value (Entity (E));
begin
if Present (Val)
and then Nkind (Val) = N_String_Literal
then
Rewrite (E, New_Copy (Val));
end if;
end;
end if;
-- Another optimization: if the nominal subtype is unconstrained and
-- the expression is a function call that returns an unconstrained
-- type, rewrite the declaration as a renaming of the result of the
-- call. The exceptions below are cases where the copy is expected,
-- either by the back end (Aliased case) or by the semantics, as for
-- initializing controlled types or copying tags for classwide types.
if Present (E)
and then Nkind (E) = N_Explicit_Dereference
and then Nkind (Original_Node (E)) = N_Function_Call
and then not Is_Library_Level_Entity (Id)
and then not Is_Constrained (Underlying_Type (T))
and then not Is_Aliased (Id)
and then not Is_Class_Wide_Type (T)
and then not Is_Controlled (T)
and then not Has_Controlled_Component (Base_Type (T))
and then Expander_Active
then
Rewrite (N,
Make_Object_Renaming_Declaration (Loc,
Defining_Identifier => Id,
Access_Definition => Empty,
Subtype_Mark => New_Occurrence_Of
(Base_Type (Etype (Id)), Loc),
Name => E));
Set_Renamed_Object (Id, E);
-- Force generation of debugging information for the constant and for
-- the renamed function call.
Set_Needs_Debug_Info (Id);
Set_Needs_Debug_Info (Entity (Prefix (E)));
end if;
if Present (Prev_Entity)
and then Is_Frozen (Prev_Entity)
and then not Error_Posted (Id)
then
Error_Msg_N ("full constant declaration appears too late", N);
end if;
Check_Eliminated (Id);
end Analyze_Object_Declaration;
---------------------------
-- Analyze_Others_Choice --
---------------------------
-- Nothing to do for the others choice node itself, the semantic analysis
-- of the others choice will occur as part of the processing of the parent
procedure Analyze_Others_Choice (N : Node_Id) is
pragma Warnings (Off, N);
begin
null;
end Analyze_Others_Choice;
--------------------------------
-- Analyze_Per_Use_Expression --
--------------------------------
procedure Analyze_Per_Use_Expression (N : Node_Id; T : Entity_Id) is
Save_In_Default_Expression : constant Boolean := In_Default_Expression;
begin
In_Default_Expression := True;
Pre_Analyze_And_Resolve (N, T);
In_Default_Expression := Save_In_Default_Expression;
end Analyze_Per_Use_Expression;
-------------------------------------------
-- Analyze_Private_Extension_Declaration --
-------------------------------------------
procedure Analyze_Private_Extension_Declaration (N : Node_Id) is
T : constant Entity_Id := Defining_Identifier (N);
Indic : constant Node_Id := Subtype_Indication (N);
Parent_Type : Entity_Id;
Parent_Base : Entity_Id;
begin
-- Ada 2005 (AI-251): Decorate all names in list of ancestor interfaces
if Is_Non_Empty_List (Interface_List (N)) then
declare
Intf : Node_Id;
T : Entity_Id;
begin
Intf := First (Interface_List (N));
while Present (Intf) loop
T := Find_Type_Of_Subtype_Indic (Intf);
if not Is_Interface (T) then
Error_Msg_NE ("(Ada 2005) & must be an interface", Intf, T);
end if;
Next (Intf);
end loop;
end;
end if;
Generate_Definition (T);
Enter_Name (T);
Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
Parent_Base := Base_Type (Parent_Type);
if Parent_Type = Any_Type
or else Etype (Parent_Type) = Any_Type
then
Set_Ekind (T, Ekind (Parent_Type));
Set_Etype (T, Any_Type);
return;
elsif not Is_Tagged_Type (Parent_Type) then
Error_Msg_N
("parent of type extension must be a tagged type ", Indic);
return;
elsif Ekind (Parent_Type) = E_Void
or else Ekind (Parent_Type) = E_Incomplete_Type
then
Error_Msg_N ("premature derivation of incomplete type", Indic);
return;
end if;
-- Perhaps the parent type should be changed to the class-wide type's
-- specific type in this case to prevent cascading errors ???
if Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N
("parent of type extension must not be a class-wide type", Indic);
return;
end if;
if (not Is_Package_Or_Generic_Package (Current_Scope)
and then Nkind (Parent (N)) /= N_Generic_Subprogram_Declaration)
or else In_Private_Part (Current_Scope)
then
Error_Msg_N ("invalid context for private extension", N);
end if;
-- Set common attributes
Set_Is_Pure (T, Is_Pure (Current_Scope));
Set_Scope (T, Current_Scope);
Set_Ekind (T, E_Record_Type_With_Private);
Init_Size_Align (T);
Set_Etype (T, Parent_Base);
Set_Has_Task (T, Has_Task (Parent_Base));
Set_Convention (T, Convention (Parent_Type));
Set_First_Rep_Item (T, First_Rep_Item (Parent_Type));
Set_Is_First_Subtype (T);
Make_Class_Wide_Type (T);
if Unknown_Discriminants_Present (N) then
Set_Discriminant_Constraint (T, No_Elist);
end if;
Build_Derived_Record_Type (N, Parent_Type, T);
if Limited_Present (N) then
Set_Is_Limited_Record (T);
if not Is_Limited_Type (Parent_Type)
and then
(not Is_Interface (Parent_Type)
or else not Is_Limited_Interface (Parent_Type))
then
Error_Msg_NE ("parent type& of limited extension must be limited",
N, Parent_Type);
end if;
end if;
end Analyze_Private_Extension_Declaration;
---------------------------------
-- Analyze_Subtype_Declaration --
---------------------------------
procedure Analyze_Subtype_Declaration (N : Node_Id) is
Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
R_Checks : Check_Result;
begin
Generate_Definition (Id);
Set_Is_Pure (Id, Is_Pure (Current_Scope));
Init_Size_Align (Id);
-- The following guard condition on Enter_Name is to handle cases where
-- the defining identifier has already been entered into the scope but
-- the declaration as a whole needs to be analyzed.
-- This case in particular happens for derived enumeration types. The
-- derived enumeration type is processed as an inserted enumeration type
-- declaration followed by a rewritten subtype declaration. The defining
-- identifier, however, is entered into the name scope very early in the
-- processing of the original type declaration and therefore needs to be
-- avoided here, when the created subtype declaration is analyzed. (See
-- Build_Derived_Types)
-- This also happens when the full view of a private type is derived
-- type with constraints. In this case the entity has been introduced
-- in the private declaration.
if Present (Etype (Id))
and then (Is_Private_Type (Etype (Id))
or else Is_Task_Type (Etype (Id))
or else Is_Rewrite_Substitution (N))
then
null;
else
Enter_Name (Id);
end if;
T := Process_Subtype (Subtype_Indication (N), N, Id, 'P');
-- Inherit common attributes
Set_Is_Generic_Type (Id, Is_Generic_Type (Base_Type (T)));
Set_Is_Volatile (Id, Is_Volatile (T));
Set_Treat_As_Volatile (Id, Treat_As_Volatile (T));
Set_Is_Atomic (Id, Is_Atomic (T));
Set_Is_Ada_2005 (Id, Is_Ada_2005 (T));
-- In the case where there is no constraint given in the subtype
-- indication, Process_Subtype just returns the Subtype_Mark, so its
-- semantic attributes must be established here.
if Nkind (Subtype_Indication (N)) /= N_Subtype_Indication then
Set_Etype (Id, Base_Type (T));
case Ekind (T) is
when Array_Kind =>
Set_Ekind (Id, E_Array_Subtype);
Copy_Array_Subtype_Attributes (Id, T);
when Decimal_Fixed_Point_Kind =>
Set_Ekind (Id, E_Decimal_Fixed_Point_Subtype);
Set_Digits_Value (Id, Digits_Value (T));
Set_Delta_Value (Id, Delta_Value (T));
Set_Scale_Value (Id, Scale_Value (T));
Set_Small_Value (Id, Small_Value (T));
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Machine_Radix_10 (Id, Machine_Radix_10 (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Enumeration_Kind =>
Set_Ekind (Id, E_Enumeration_Subtype);
Set_First_Literal (Id, First_Literal (Base_Type (T)));
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Character_Type (Id, Is_Character_Type (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Ordinary_Fixed_Point_Kind =>
Set_Ekind (Id, E_Ordinary_Fixed_Point_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Small_Value (Id, Small_Value (T));
Set_Delta_Value (Id, Delta_Value (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Float_Kind =>
Set_Ekind (Id, E_Floating_Point_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Digits_Value (Id, Digits_Value (T));
Set_Is_Constrained (Id, Is_Constrained (T));
when Signed_Integer_Kind =>
Set_Ekind (Id, E_Signed_Integer_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Modular_Integer_Kind =>
Set_Ekind (Id, E_Modular_Integer_Subtype);
Set_Scalar_Range (Id, Scalar_Range (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_RM_Size (Id, RM_Size (T));
when Class_Wide_Kind =>
Set_Ekind (Id, E_Class_Wide_Subtype);
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
Set_Cloned_Subtype (Id, T);
Set_Is_Tagged_Type (Id, True);
Set_Has_Unknown_Discriminants
(Id, True);
if Ekind (T) = E_Class_Wide_Subtype then
Set_Equivalent_Type (Id, Equivalent_Type (T));
end if;
when E_Record_Type | E_Record_Subtype =>
Set_Ekind (Id, E_Record_Subtype);
if Ekind (T) = E_Record_Subtype
and then Present (Cloned_Subtype (T))
then
Set_Cloned_Subtype (Id, Cloned_Subtype (T));
else
Set_Cloned_Subtype (Id, T);
end if;
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Unknown_Discriminants
(Id, Has_Unknown_Discriminants (T));
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
elsif Has_Unknown_Discriminants (Id) then
Set_Discriminant_Constraint (Id, No_Elist);
end if;
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Id);
Set_Is_Abstract (Id, Is_Abstract (T));
Set_Primitive_Operations
(Id, Primitive_Operations (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
end if;
when Private_Kind =>
Set_Ekind (Id, Subtype_Kind (Ekind (T)));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_First_Entity (Id, First_Entity (T));
Set_Last_Entity (Id, Last_Entity (T));
Set_Private_Dependents (Id, New_Elmt_List);
Set_Is_Limited_Record (Id, Is_Limited_Record (T));
Set_Has_Unknown_Discriminants
(Id, Has_Unknown_Discriminants (T));
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Id);
Set_Is_Abstract (Id, Is_Abstract (T));
Set_Primitive_Operations
(Id, Primitive_Operations (T));
Set_Class_Wide_Type (Id, Class_Wide_Type (T));
end if;
-- In general the attributes of the subtype of a private type
-- are the attributes of the partial view of parent. However,
-- the full view may be a discriminated type, and the subtype
-- must share the discriminant constraint to generate correct
-- calls to initialization procedures.
if Has_Discriminants (T) then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (T));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
elsif Present (Full_View (T))
and then Has_Discriminants (Full_View (T))
then
Set_Discriminant_Constraint
(Id, Discriminant_Constraint (Full_View (T)));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
-- This would seem semantically correct, but apparently
-- confuses the back-end (4412-009). To be explained ???
-- Set_Has_Discriminants (Id);
end if;
Prepare_Private_Subtype_Completion (Id, N);
when Access_Kind =>
Set_Ekind (Id, E_Access_Subtype);
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Is_Access_Constant
(Id, Is_Access_Constant (T));
Set_Directly_Designated_Type
(Id, Designated_Type (T));
Set_Can_Never_Be_Null (Id, Can_Never_Be_Null (T));
-- A Pure library_item must not contain the declaration of a
-- named access type, except within a subprogram, generic
-- subprogram, task unit, or protected unit (RM 10.2.1(16)).
if Comes_From_Source (Id)
and then In_Pure_Unit
and then not In_Subprogram_Task_Protected_Unit
then
Error_Msg_N
("named access types not allowed in pure unit", N);
end if;
when Concurrent_Kind =>
Set_Ekind (Id, Subtype_Kind (Ekind (T)));
Set_Corresponding_Record_Type (Id,
Corresponding_Record_Type (T));
Set_First_Entity (Id, First_Entity (T));
Set_First_Private_Entity (Id, First_Private_Entity (T));
Set_Has_Discriminants (Id, Has_Discriminants (T));
Set_Is_Constrained (Id, Is_Constrained (T));
Set_Last_Entity (Id, Last_Entity (T));
if Has_Discriminants (T) then
Set_Discriminant_Constraint (Id,
Discriminant_Constraint (T));
Set_Stored_Constraint_From_Discriminant_Constraint (Id);
end if;
-- If the subtype name denotes an incomplete type an error was
-- already reported by Process_Subtype.
when E_Incomplete_Type =>
Set_Etype (Id, Any_Type);
when others =>
raise Program_Error;
end case;
end if;
if Etype (Id) = Any_Type then
return;
end if;
-- Some common processing on all types
Set_Size_Info (Id, T);
Set_First_Rep_Item (Id, First_Rep_Item (T));
T := Etype (Id);
Set_Is_Immediately_Visible (Id, True);
Set_Depends_On_Private (Id, Has_Private_Component (T));
if Present (Generic_Parent_Type (N))
and then
(Nkind
(Parent (Generic_Parent_Type (N))) /= N_Formal_Type_Declaration
or else Nkind
(Formal_Type_Definition (Parent (Generic_Parent_Type (N))))
/= N_Formal_Private_Type_Definition)
then
if Is_Tagged_Type (Id) then
if Is_Class_Wide_Type (Id) then
Derive_Subprograms (Generic_Parent_Type (N), Id, Etype (T));
else
Derive_Subprograms (Generic_Parent_Type (N), Id, T);
end if;
elsif Scope (Etype (Id)) /= Standard_Standard then
Derive_Subprograms (Generic_Parent_Type (N), Id);
end if;
end if;
if Is_Private_Type (T)
and then Present (Full_View (T))
then
Conditional_Delay (Id, Full_View (T));
-- The subtypes of components or subcomponents of protected types
-- do not need freeze nodes, which would otherwise appear in the
-- wrong scope (before the freeze node for the protected type). The
-- proper subtypes are those of the subcomponents of the corresponding
-- record.
elsif Ekind (Scope (Id)) /= E_Protected_Type
and then Present (Scope (Scope (Id))) -- error defense!
and then Ekind (Scope (Scope (Id))) /= E_Protected_Type
then
Conditional_Delay (Id, T);
end if;
-- Check that constraint_error is raised for a scalar subtype
-- indication when the lower or upper bound of a non-null range
-- lies outside the range of the type mark.
if Nkind (Subtype_Indication (N)) = N_Subtype_Indication then
if Is_Scalar_Type (Etype (Id))
and then Scalar_Range (Id) /=
Scalar_Range (Etype (Subtype_Mark
(Subtype_Indication (N))))
then
Apply_Range_Check
(Scalar_Range (Id),
Etype (Subtype_Mark (Subtype_Indication (N))));
elsif Is_Array_Type (Etype (Id))
and then Present (First_Index (Id))
then
-- This really should be a subprogram that finds the indications
-- to check???
if ((Nkind (First_Index (Id)) = N_Identifier
and then Ekind (Entity (First_Index (Id))) in Scalar_Kind)
or else Nkind (First_Index (Id)) = N_Subtype_Indication)
and then
Nkind (Scalar_Range (Etype (First_Index (Id)))) = N_Range
then
declare
Target_Typ : constant Entity_Id :=
Etype
(First_Index (Etype
(Subtype_Mark (Subtype_Indication (N)))));
begin
R_Checks :=
Range_Check
(Scalar_Range (Etype (First_Index (Id))),
Target_Typ,
Etype (First_Index (Id)),
Defining_Identifier (N));
Insert_Range_Checks
(R_Checks,
N,
Target_Typ,
Sloc (Defining_Identifier (N)));
end;
end if;
end if;
end if;
Check_Eliminated (Id);
end Analyze_Subtype_Declaration;
--------------------------------
-- Analyze_Subtype_Indication --
--------------------------------
procedure Analyze_Subtype_Indication (N : Node_Id) is
T : constant Entity_Id := Subtype_Mark (N);
R : constant Node_Id := Range_Expression (Constraint (N));
begin
Analyze (T);
if R /= Error then
Analyze (R);
Set_Etype (N, Etype (R));
else
Set_Error_Posted (R);
Set_Error_Posted (T);
end if;
end Analyze_Subtype_Indication;
------------------------------
-- Analyze_Type_Declaration --
------------------------------
procedure Analyze_Type_Declaration (N : Node_Id) is
Def : constant Node_Id := Type_Definition (N);
Def_Id : constant Entity_Id := Defining_Identifier (N);
T : Entity_Id;
Prev : Entity_Id;
Is_Remote : constant Boolean :=
(Is_Remote_Types (Current_Scope)
or else Is_Remote_Call_Interface (Current_Scope))
and then not (In_Private_Part (Current_Scope)
or else
In_Package_Body (Current_Scope));
procedure Check_Ops_From_Incomplete_Type;
-- If there is a tagged incomplete partial view of the type, transfer
-- its operations to the full view, and indicate that the type of the
-- controlling parameter (s) is this full view.
------------------------------------
-- Check_Ops_From_Incomplete_Type --
------------------------------------
procedure Check_Ops_From_Incomplete_Type is
Elmt : Elmt_Id;
Formal : Entity_Id;
Op : Entity_Id;
begin
if Prev /= T
and then Ekind (Prev) = E_Incomplete_Type
and then Is_Tagged_Type (Prev)
and then Is_Tagged_Type (T)
then
Elmt := First_Elmt (Primitive_Operations (Prev));
while Present (Elmt) loop
Op := Node (Elmt);
Prepend_Elmt (Op, Primitive_Operations (T));
Formal := First_Formal (Op);
while Present (Formal) loop
if Etype (Formal) = Prev then
Set_Etype (Formal, T);
end if;
Next_Formal (Formal);
end loop;
if Etype (Op) = Prev then
Set_Etype (Op, T);
end if;
Next_Elmt (Elmt);
end loop;
end if;
end Check_Ops_From_Incomplete_Type;
-- Start of processing for Analyze_Type_Declaration
begin
Prev := Find_Type_Name (N);
-- The full view, if present, now points to the current type
-- Ada 2005 (AI-50217): If the type was previously decorated when
-- imported through a LIMITED WITH clause, it appears as incomplete
-- but has no full view.
if Ekind (Prev) = E_Incomplete_Type
and then Present (Full_View (Prev))
then
T := Full_View (Prev);
else
T := Prev;
end if;
Set_Is_Pure (T, Is_Pure (Current_Scope));
-- We set the flag Is_First_Subtype here. It is needed to set the
-- corresponding flag for the Implicit class-wide-type created
-- during tagged types processing.
Set_Is_First_Subtype (T, True);
-- Only composite types other than array types are allowed to have
-- discriminants.
case Nkind (Def) is
-- For derived types, the rule will be checked once we've figured
-- out the parent type.
when N_Derived_Type_Definition =>
null;
-- For record types, discriminants are allowed
when N_Record_Definition =>
null;
when others =>
if Present (Discriminant_Specifications (N)) then
Error_Msg_N
("elementary or array type cannot have discriminants",
Defining_Identifier
(First (Discriminant_Specifications (N))));
end if;
end case;
-- Elaborate the type definition according to kind, and generate
-- subsidiary (implicit) subtypes where needed. We skip this if
-- it was already done (this happens during the reanalysis that
-- follows a call to the high level optimizer).
if not Analyzed (T) then
Set_Analyzed (T);
case Nkind (Def) is
when N_Access_To_Subprogram_Definition =>
Access_Subprogram_Declaration (T, Def);
-- If this is a remote access to subprogram, we must create
-- the equivalent fat pointer type, and related subprograms.
if Is_Remote then
Process_Remote_AST_Declaration (N);
end if;
-- Validate categorization rule against access type declaration
-- usually a violation in Pure unit, Shared_Passive unit.
Validate_Access_Type_Declaration (T, N);
when N_Access_To_Object_Definition =>
Access_Type_Declaration (T, Def);
-- Validate categorization rule against access type declaration
-- usually a violation in Pure unit, Shared_Passive unit.
Validate_Access_Type_Declaration (T, N);
-- If we are in a Remote_Call_Interface package and define
-- a RACW, Read and Write attribute must be added.
if Is_Remote
and then Is_Remote_Access_To_Class_Wide_Type (Def_Id)
then
Add_RACW_Features (Def_Id);
end if;
-- Set no strict aliasing flag if config pragma seen
if Opt.No_Strict_Aliasing then
Set_No_Strict_Aliasing (Base_Type (Def_Id));
end if;
when N_Array_Type_Definition =>
Array_Type_Declaration (T, Def);
when N_Derived_Type_Definition =>
Derived_Type_Declaration (T, N, T /= Def_Id);
when N_Enumeration_Type_Definition =>
Enumeration_Type_Declaration (T, Def);
when N_Floating_Point_Definition =>
Floating_Point_Type_Declaration (T, Def);
when N_Decimal_Fixed_Point_Definition =>
Decimal_Fixed_Point_Type_Declaration (T, Def);
when N_Ordinary_Fixed_Point_Definition =>
Ordinary_Fixed_Point_Type_Declaration (T, Def);
when N_Signed_Integer_Type_Definition =>
Signed_Integer_Type_Declaration (T, Def);
when N_Modular_Type_Definition =>
Modular_Type_Declaration (T, Def);
when N_Record_Definition =>
Record_Type_Declaration (T, N, Prev);
when others =>
raise Program_Error;
end case;
end if;
if Etype (T) = Any_Type then
return;
end if;
-- Some common processing for all types
Set_Depends_On_Private (T, Has_Private_Component (T));
Check_Ops_From_Incomplete_Type;
-- Both the declared entity, and its anonymous base type if one
-- was created, need freeze nodes allocated.
declare
B : constant Entity_Id := Base_Type (T);
begin
-- In the case where the base type is different from the first
-- subtype, we pre-allocate a freeze node, and set the proper link
-- to the first subtype. Freeze_Entity will use this preallocated
-- freeze node when it freezes the entity.
if B /= T then
Ensure_Freeze_Node (B);
Set_First_Subtype_Link (Freeze_Node (B), T);
end if;
if not From_With_Type (T) then
Set_Has_Delayed_Freeze (T);
end if;
end;
-- Case of T is the full declaration of some private type which has
-- been swapped in Defining_Identifier (N).
if T /= Def_Id and then Is_Private_Type (Def_Id) then
Process_Full_View (N, T, Def_Id);
-- Record the reference. The form of this is a little strange,
-- since the full declaration has been swapped in. So the first
-- parameter here represents the entity to which a reference is
-- made which is the "real" entity, i.e. the one swapped in,
-- and the second parameter provides the reference location.
Generate_Reference (T, T, 'c');
Set_Completion_Referenced (Def_Id);
-- For completion of incomplete type, process incomplete dependents
-- and always mark the full type as referenced (it is the incomplete
-- type that we get for any real reference).
elsif Ekind (Prev) = E_Incomplete_Type then
Process_Incomplete_Dependents (N, T, Prev);
Generate_Reference (Prev, Def_Id, 'c');
Set_Completion_Referenced (Def_Id);
-- If not private type or incomplete type completion, this is a real
-- definition of a new entity, so record it.
else
Generate_Definition (Def_Id);
end if;
Check_Eliminated (Def_Id);
end Analyze_Type_Declaration;
--------------------------
-- Analyze_Variant_Part --
--------------------------
procedure Analyze_Variant_Part (N : Node_Id) is
procedure Non_Static_Choice_Error (Choice : Node_Id);
-- Error routine invoked by the generic instantiation below when
-- the variant part has a non static choice.
procedure Process_Declarations (Variant : Node_Id);
-- Analyzes all the declarations associated with a Variant.
-- Needed by the generic instantiation below.
package Variant_Choices_Processing is new
Generic_Choices_Processing
(Get_Alternatives => Variants,
Get_Choices => Discrete_Choices,
Process_Empty_Choice => No_OP,
Process_Non_Static_Choice => Non_Static_Choice_Error,
Process_Associated_Node => Process_Declarations);
use Variant_Choices_Processing;
-- Instantiation of the generic choice processing package
-----------------------------
-- Non_Static_Choice_Error --
-----------------------------
procedure Non_Static_Choice_Error (Choice : Node_Id) is
begin
Flag_Non_Static_Expr
("choice given in variant part is not static!", Choice);
end Non_Static_Choice_Error;
--------------------------
-- Process_Declarations --
--------------------------
procedure Process_Declarations (Variant : Node_Id) is
begin
if not Null_Present (Component_List (Variant)) then
Analyze_Declarations (Component_Items (Component_List (Variant)));
if Present (Variant_Part (Component_List (Variant))) then
Analyze (Variant_Part (Component_List (Variant)));
end if;
end if;
end Process_Declarations;
-- Variables local to Analyze_Case_Statement
Discr_Name : Node_Id;
Discr_Type : Entity_Id;
Case_Table : Choice_Table_Type (1 .. Number_Of_Choices (N));
Last_Choice : Nat;
Dont_Care : Boolean;
Others_Present : Boolean := False;
-- Start of processing for Analyze_Variant_Part
begin
Discr_Name := Name (N);
Analyze (Discr_Name);
if Ekind (Entity (Discr_Name)) /= E_Discriminant then
Error_Msg_N ("invalid discriminant name in variant part", Discr_Name);
end if;
Discr_Type := Etype (Entity (Discr_Name));
if not Is_Discrete_Type (Discr_Type) then
Error_Msg_N
("discriminant in a variant part must be of a discrete type",
Name (N));
return;
end if;
-- Call the instantiated Analyze_Choices which does the rest of the work
Analyze_Choices
(N, Discr_Type, Case_Table, Last_Choice, Dont_Care, Others_Present);
end Analyze_Variant_Part;
----------------------------
-- Array_Type_Declaration --
----------------------------
procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id) is
Component_Def : constant Node_Id := Component_Definition (Def);
Element_Type : Entity_Id;
Implicit_Base : Entity_Id;
Index : Node_Id;
Related_Id : Entity_Id := Empty;
Nb_Index : Nat;
P : constant Node_Id := Parent (Def);
Priv : Entity_Id;
begin
if Nkind (Def) = N_Constrained_Array_Definition then
Index := First (Discrete_Subtype_Definitions (Def));
else
Index := First (Subtype_Marks (Def));
end if;
-- Find proper names for the implicit types which may be public.
-- in case of anonymous arrays we use the name of the first object
-- of that type as prefix.
if No (T) then
Related_Id := Defining_Identifier (P);
else
Related_Id := T;
end if;
Nb_Index := 1;
while Present (Index) loop
Analyze (Index);
Make_Index (Index, P, Related_Id, Nb_Index);
Next_Index (Index);
Nb_Index := Nb_Index + 1;
end loop;
if Present (Subtype_Indication (Component_Def)) then
Element_Type := Process_Subtype (Subtype_Indication (Component_Def),
P, Related_Id, 'C');
-- Ada 2005 (AI-230): Access Definition case
else pragma Assert (Present (Access_Definition (Component_Def)));
Element_Type := Access_Definition
(Related_Nod => Related_Id,
N => Access_Definition (Component_Def));
Set_Is_Local_Anonymous_Access (Element_Type);
-- Ada 2005 (AI-230): In case of components that are anonymous
-- access types the level of accessibility depends on the enclosing
-- type declaration
Set_Scope (Element_Type, Current_Scope); -- Ada 2005 (AI-230)
-- Ada 2005 (AI-254)
declare
CD : constant Node_Id :=
Access_To_Subprogram_Definition
(Access_Definition (Component_Def));
begin
if Present (CD) and then Protected_Present (CD) then
Element_Type :=
Replace_Anonymous_Access_To_Protected_Subprogram
(Def, Element_Type);
end if;
end;
end if;
-- Constrained array case
if No (T) then
T := Create_Itype (E_Void, P, Related_Id, 'T');
end if;
if Nkind (Def) = N_Constrained_Array_Definition then
-- Establish Implicit_Base as unconstrained base type
Implicit_Base := Create_Itype (E_Array_Type, P, Related_Id, 'B');
Init_Size_Align (Implicit_Base);
Set_Etype (Implicit_Base, Implicit_Base);
Set_Scope (Implicit_Base, Current_Scope);
Set_Has_Delayed_Freeze (Implicit_Base);
-- The constrained array type is a subtype of the unconstrained one
Set_Ekind (T, E_Array_Subtype);
Init_Size_Align (T);
Set_Etype (T, Implicit_Base);
Set_Scope (T, Current_Scope);
Set_Is_Constrained (T, True);
Set_First_Index (T, First (Discrete_Subtype_Definitions (Def)));
Set_Has_Delayed_Freeze (T);
-- Complete setup of implicit base type
Set_First_Index (Implicit_Base, First_Index (T));
Set_Component_Type (Implicit_Base, Element_Type);
Set_Has_Task (Implicit_Base, Has_Task (Element_Type));
Set_Component_Size (Implicit_Base, Uint_0);
Set_Has_Controlled_Component
(Implicit_Base, Has_Controlled_Component
(Element_Type)
or else
Is_Controlled (Element_Type));
Set_Finalize_Storage_Only
(Implicit_Base, Finalize_Storage_Only
(Element_Type));
-- Unconstrained array case
else
Set_Ekind (T, E_Array_Type);
Init_Size_Align (T);
Set_Etype (T, T);
Set_Scope (T, Current_Scope);
Set_Component_Size (T, Uint_0);
Set_Is_Constrained (T, False);
Set_First_Index (T, First (Subtype_Marks (Def)));
Set_Has_Delayed_Freeze (T, True);
Set_Has_Task (T, Has_Task (Element_Type));
Set_Has_Controlled_Component (T, Has_Controlled_Component
(Element_Type)
or else
Is_Controlled (Element_Type));
Set_Finalize_Storage_Only (T, Finalize_Storage_Only
(Element_Type));
end if;
Set_Component_Type (Base_Type (T), Element_Type);
if Aliased_Present (Component_Definition (Def)) then
Set_Has_Aliased_Components (Etype (T));
end if;
-- Ada 2005 (AI-231): Propagate the null-excluding attribute to the
-- array type to ensure that objects of this type are initialized.
if Ada_Version >= Ada_05
and then Can_Never_Be_Null (Element_Type)
then
Set_Can_Never_Be_Null (T);
if Null_Exclusion_Present (Component_Definition (Def))
and then Can_Never_Be_Null (Element_Type)
-- No need to check itypes because in their case this check
-- was done at their point of creation
and then not Is_Itype (Element_Type)
then
Error_Msg_N
("(Ada 2005) already a null-excluding type",
Subtype_Indication (Component_Definition (Def)));
end if;
end if;
Priv := Private_Component (Element_Type);
if Present (Priv) then
-- Check for circular definitions
if Priv = Any_Type then
Set_Component_Type (Etype (T), Any_Type);
-- There is a gap in the visibility of operations on the composite
-- type only if the component type is defined in a different scope.
elsif Scope (Priv) = Current_Scope then
null;
elsif Is_Limited_Type (Priv) then
Set_Is_Limited_Composite (Etype (T));
Set_Is_Limited_Composite (T);
else
Set_Is_Private_Composite (Etype (T));
Set_Is_Private_Composite (T);
end if;
end if;
-- Create a concatenation operator for the new type. Internal
-- array types created for packed entities do not need such, they
-- are compatible with the user-defined type.
if Number_Dimensions (T) = 1
and then not Is_Packed_Array_Type (T)
then
New_Concatenation_Op (T);
end if;
-- In the case of an unconstrained array the parser has already
-- verified that all the indices are unconstrained but we still
-- need to make sure that the element type is constrained.
if Is_Indefinite_Subtype (Element_Type) then
Error_Msg_N
("unconstrained element type in array declaration",
Subtype_Indication (Component_Def));
elsif Is_Abstract (Element_Type) then
Error_Msg_N
("the type of a component cannot be abstract",
Subtype_Indication (Component_Def));
end if;
end Array_Type_Declaration;
------------------------------------------------------
-- Replace_Anonymous_Access_To_Protected_Subprogram --
------------------------------------------------------
function Replace_Anonymous_Access_To_Protected_Subprogram
(N : Node_Id;
Prev_E : Entity_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (N);
Curr_Scope : constant Scope_Stack_Entry :=
Scope_Stack.Table (Scope_Stack.Last);
Anon : constant Entity_Id :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('S'));
Acc : Node_Id;
Comp : Node_Id;
Decl : Node_Id;
P : Node_Id;
begin
Set_Is_Internal (Anon);
case Nkind (N) is
when N_Component_Declaration |
N_Unconstrained_Array_Definition |
N_Constrained_Array_Definition =>
Comp := Component_Definition (N);
Acc := Access_Definition (Component_Definition (N));
when N_Discriminant_Specification =>
Comp := Discriminant_Type (N);
Acc := Discriminant_Type (N);
when N_Parameter_Specification =>
Comp := Parameter_Type (N);
Acc := Parameter_Type (N);
when others =>
raise Program_Error;
end case;
Decl := Make_Full_Type_Declaration (Loc,
Defining_Identifier => Anon,
Type_Definition =>
Copy_Separate_Tree (Access_To_Subprogram_Definition (Acc)));
Mark_Rewrite_Insertion (Decl);
-- Insert the new declaration in the nearest enclosing scope
P := Parent (N);
while Present (P) and then not Has_Declarations (P) loop
P := Parent (P);
end loop;
pragma Assert (Present (P));
if Nkind (P) = N_Package_Specification then
Prepend (Decl, Visible_Declarations (P));
else
Prepend (Decl, Declarations (P));
end if;
-- Replace the anonymous type with an occurrence of the new declaration.
-- In all cases the rewritten node does not have the null-exclusion
-- attribute because (if present) it was already inherited by the
-- anonymous entity (Anon). Thus, in case of components we do not
-- inherit this attribute.
if Nkind (N) = N_Parameter_Specification then
Rewrite (Comp, New_Occurrence_Of (Anon, Loc));
Set_Etype (Defining_Identifier (N), Anon);
Set_Null_Exclusion_Present (N, False);
else
Rewrite (Comp,
Make_Component_Definition (Loc,
Subtype_Indication => New_Occurrence_Of (Anon, Loc)));
end if;
Mark_Rewrite_Insertion (Comp);
-- Temporarily remove the current scope from the stack to add the new
-- declarations to the enclosing scope
Scope_Stack.Decrement_Last;
Analyze (Decl);
Scope_Stack.Append (Curr_Scope);
Set_Original_Access_Type (Anon, Prev_E);
return Anon;
end Replace_Anonymous_Access_To_Protected_Subprogram;
-------------------------------
-- Build_Derived_Access_Type --
-------------------------------
procedure Build_Derived_Access_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
S : constant Node_Id := Subtype_Indication (Type_Definition (N));
Desig_Type : Entity_Id;
Discr : Entity_Id;
Discr_Con_Elist : Elist_Id;
Discr_Con_El : Elmt_Id;
Subt : Entity_Id;
begin
-- Set the designated type so it is available in case this is
-- an access to a self-referential type, e.g. a standard list
-- type with a next pointer. Will be reset after subtype is built.
Set_Directly_Designated_Type
(Derived_Type, Designated_Type (Parent_Type));
Subt := Process_Subtype (S, N);
if Nkind (S) /= N_Subtype_Indication
and then Subt /= Base_Type (Subt)
then
Set_Ekind (Derived_Type, E_Access_Subtype);
end if;
if Ekind (Derived_Type) = E_Access_Subtype then
declare
Pbase : constant Entity_Id := Base_Type (Parent_Type);
Ibase : constant Entity_Id :=
Create_Itype (Ekind (Pbase), N, Derived_Type, 'B');
Svg_Chars : constant Name_Id := Chars (Ibase);
Svg_Next_E : constant Entity_Id := Next_Entity (Ibase);
begin
Copy_Node (Pbase, Ibase);
Set_Chars (Ibase, Svg_Chars);
Set_Next_Entity (Ibase, Svg_Next_E);
Set_Sloc (Ibase, Sloc (Derived_Type));
Set_Scope (Ibase, Scope (Derived_Type));
Set_Freeze_Node (Ibase, Empty);
Set_Is_Frozen (Ibase, False);
Set_Comes_From_Source (Ibase, False);
Set_Is_First_Subtype (Ibase, False);
Set_Etype (Ibase, Pbase);
Set_Etype (Derived_Type, Ibase);
end;
end if;
Set_Directly_Designated_Type
(Derived_Type, Designated_Type (Subt));
Set_Is_Constrained (Derived_Type, Is_Constrained (Subt));
Set_Is_Access_Constant (Derived_Type, Is_Access_Constant (Parent_Type));
Set_Size_Info (Derived_Type, Parent_Type);
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
Set_Depends_On_Private (Derived_Type,
Has_Private_Component (Derived_Type));
Conditional_Delay (Derived_Type, Subt);
-- Ada 2005 (AI-231). Set the null-exclusion attribute
if Null_Exclusion_Present (Type_Definition (N))
or else Can_Never_Be_Null (Parent_Type)
then
Set_Can_Never_Be_Null (Derived_Type);
end if;
-- Note: we do not copy the Storage_Size_Variable, since
-- we always go to the root type for this information.
-- Apply range checks to discriminants for derived record case
-- ??? THIS CODE SHOULD NOT BE HERE REALLY.
Desig_Type := Designated_Type (Derived_Type);
if Is_Composite_Type (Desig_Type)
and then (not Is_Array_Type (Desig_Type))
and then Has_Discriminants (Desig_Type)
and then Base_Type (Desig_Type) /= Desig_Type
then
Discr_Con_Elist := Discriminant_Constraint (Desig_Type);
Discr_Con_El := First_Elmt (Discr_Con_Elist);
Discr := First_Discriminant (Base_Type (Desig_Type));
while Present (Discr_Con_El) loop
Apply_Range_Check (Node (Discr_Con_El), Etype (Discr));
Next_Elmt (Discr_Con_El);
Next_Discriminant (Discr);
end loop;
end if;
end Build_Derived_Access_Type;
------------------------------
-- Build_Derived_Array_Type --
------------------------------
procedure Build_Derived_Array_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Tdef : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Tdef);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
Implicit_Base : Entity_Id;
New_Indic : Node_Id;
procedure Make_Implicit_Base;
-- If the parent subtype is constrained, the derived type is a
-- subtype of an implicit base type derived from the parent base.
------------------------
-- Make_Implicit_Base --
------------------------
procedure Make_Implicit_Base is
begin
Implicit_Base :=
Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
Set_Ekind (Implicit_Base, Ekind (Parent_Base));
Set_Etype (Implicit_Base, Parent_Base);
Copy_Array_Subtype_Attributes (Implicit_Base, Parent_Base);
Copy_Array_Base_Type_Attributes (Implicit_Base, Parent_Base);
Set_Has_Delayed_Freeze (Implicit_Base, True);
end Make_Implicit_Base;
-- Start of processing for Build_Derived_Array_Type
begin
if not Is_Constrained (Parent_Type) then
if Nkind (Indic) /= N_Subtype_Indication then
Set_Ekind (Derived_Type, E_Array_Type);
Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
Copy_Array_Base_Type_Attributes (Derived_Type, Parent_Type);
Set_Has_Delayed_Freeze (Derived_Type, True);
else
Make_Implicit_Base;
Set_Etype (Derived_Type, Implicit_Base);
New_Indic :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Implicit_Base, Loc),
Constraint => Constraint (Indic)));
Rewrite (N, New_Indic);
Analyze (N);
end if;
else
if Nkind (Indic) /= N_Subtype_Indication then
Make_Implicit_Base;
Set_Ekind (Derived_Type, Ekind (Parent_Type));
Set_Etype (Derived_Type, Implicit_Base);
Copy_Array_Subtype_Attributes (Derived_Type, Parent_Type);
else
Error_Msg_N ("illegal constraint on constrained type", Indic);
end if;
end if;
-- If parent type is not a derived type itself, and is declared in
-- closed scope (e.g. a subprogram), then we must explicitly introduce
-- the new type's concatenation operator since Derive_Subprograms
-- will not inherit the parent's operator. If the parent type is
-- unconstrained, the operator is of the unconstrained base type.
if Number_Dimensions (Parent_Type) = 1
and then not Is_Limited_Type (Parent_Type)
and then not Is_Derived_Type (Parent_Type)
and then not Is_Package_Or_Generic_Package
(Scope (Base_Type (Parent_Type)))
then
if not Is_Constrained (Parent_Type)
and then Is_Constrained (Derived_Type)
then
New_Concatenation_Op (Implicit_Base);
else
New_Concatenation_Op (Derived_Type);
end if;
end if;
end Build_Derived_Array_Type;
-----------------------------------
-- Build_Derived_Concurrent_Type --
-----------------------------------
procedure Build_Derived_Concurrent_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
D_Constraint : Node_Id;
Disc_Spec : Node_Id;
Old_Disc : Entity_Id;
New_Disc : Entity_Id;
Constraint_Present : constant Boolean :=
Nkind (Subtype_Indication (Type_Definition (N)))
= N_Subtype_Indication;
begin
Set_Stored_Constraint (Derived_Type, No_Elist);
if Is_Task_Type (Parent_Type) then
Set_Storage_Size_Variable (Derived_Type,
Storage_Size_Variable (Parent_Type));
end if;
if Present (Discriminant_Specifications (N)) then
New_Scope (Derived_Type);
Check_Or_Process_Discriminants (N, Derived_Type);
End_Scope;
elsif Constraint_Present then
-- Build constrained subtype and derive from it
declare
Loc : constant Source_Ptr := Sloc (N);
Anon : constant Entity_Id :=
Make_Defining_Identifier (Loc,
New_External_Name (Chars (Derived_Type), 'T'));
Decl : Node_Id;
begin
Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Anon,
Subtype_Indication =>
New_Copy_Tree (Subtype_Indication (Type_Definition (N))));
Insert_Before (N, Decl);
Rewrite (Subtype_Indication (Type_Definition (N)),
New_Occurrence_Of (Anon, Loc));
Analyze (Decl);
Set_Analyzed (Derived_Type, False);
Analyze (N);
return;
end;
end if;
-- All attributes are inherited from parent. In particular,
-- entries and the corresponding record type are the same.
-- Discriminants may be renamed, and must be treated separately.
Set_Has_Discriminants
(Derived_Type, Has_Discriminants (Parent_Type));
Set_Corresponding_Record_Type
(Derived_Type, Corresponding_Record_Type (Parent_Type));
if Constraint_Present then
if not Has_Discriminants (Parent_Type) then
Error_Msg_N ("untagged parent must have discriminants", N);
elsif Present (Discriminant_Specifications (N)) then
-- Verify that new discriminants are used to constrain old ones
D_Constraint :=
First
(Constraints
(Constraint (Subtype_Indication (Type_Definition (N)))));
Old_Disc := First_Discriminant (Parent_Type);
New_Disc := First_Discriminant (Derived_Type);
Disc_Spec := First (Discriminant_Specifications (N));
while Present (Old_Disc) and then Present (Disc_Spec) loop
if Nkind (Discriminant_Type (Disc_Spec)) /=
N_Access_Definition
then
Analyze (Discriminant_Type (Disc_Spec));
if not Subtypes_Statically_Compatible (
Etype (Discriminant_Type (Disc_Spec)),
Etype (Old_Disc))
then
Error_Msg_N
("not statically compatible with parent discriminant",
Discriminant_Type (Disc_Spec));
end if;
end if;
if Nkind (D_Constraint) = N_Identifier
and then Chars (D_Constraint) /=
Chars (Defining_Identifier (Disc_Spec))
then
Error_Msg_N ("new discriminants must constrain old ones",
D_Constraint);
else
Set_Corresponding_Discriminant (New_Disc, Old_Disc);
end if;
Next_Discriminant (Old_Disc);
Next_Discriminant (New_Disc);
Next (Disc_Spec);
end loop;
if Present (Old_Disc) or else Present (Disc_Spec) then
Error_Msg_N ("discriminant mismatch in derivation", N);
end if;
end if;
elsif Present (Discriminant_Specifications (N)) then
Error_Msg_N
("missing discriminant constraint in untagged derivation",
N);
end if;
if Present (Discriminant_Specifications (N)) then
Old_Disc := First_Discriminant (Parent_Type);
while Present (Old_Disc) loop
if No (Next_Entity (Old_Disc))
or else Ekind (Next_Entity (Old_Disc)) /= E_Discriminant
then
Set_Next_Entity (Last_Entity (Derived_Type),
Next_Entity (Old_Disc));
exit;
end if;
Next_Discriminant (Old_Disc);
end loop;
else
Set_First_Entity (Derived_Type, First_Entity (Parent_Type));
if Has_Discriminants (Parent_Type) then
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
Set_Discriminant_Constraint (
Derived_Type, Discriminant_Constraint (Parent_Type));
end if;
end if;
Set_Last_Entity (Derived_Type, Last_Entity (Parent_Type));
Set_Has_Completion (Derived_Type);
end Build_Derived_Concurrent_Type;
------------------------------------
-- Build_Derived_Enumeration_Type --
------------------------------------
procedure Build_Derived_Enumeration_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Implicit_Base : Entity_Id;
Literal : Entity_Id;
New_Lit : Entity_Id;
Literals_List : List_Id;
Type_Decl : Node_Id;
Hi, Lo : Node_Id;
Rang_Expr : Node_Id;
begin
-- Since types Standard.Character and Standard.Wide_Character do
-- not have explicit literals lists we need to process types derived
-- from them specially. This is handled by Derived_Standard_Character.
-- If the parent type is a generic type, there are no literals either,
-- and we construct the same skeletal representation as for the generic
-- parent type.
if Root_Type (Parent_Type) = Standard_Character
or else Root_Type (Parent_Type) = Standard_Wide_Character
or else Root_Type (Parent_Type) = Standard_Wide_Wide_Character
then
Derived_Standard_Character (N, Parent_Type, Derived_Type);
elsif Is_Generic_Type (Root_Type (Parent_Type)) then
declare
Lo : Node_Id;
Hi : Node_Id;
begin
Lo :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix => New_Reference_To (Derived_Type, Loc));
Set_Etype (Lo, Derived_Type);
Hi :=
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix => New_Reference_To (Derived_Type, Loc));
Set_Etype (Hi, Derived_Type);
Set_Scalar_Range (Derived_Type,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
end;
else
-- If a constraint is present, analyze the bounds to catch
-- premature usage of the derived literals.
if Nkind (Indic) = N_Subtype_Indication
and then Nkind (Range_Expression (Constraint (Indic))) = N_Range
then
Analyze (Low_Bound (Range_Expression (Constraint (Indic))));
Analyze (High_Bound (Range_Expression (Constraint (Indic))));
end if;
-- Introduce an implicit base type for the derived type even
-- if there is no constraint attached to it, since this seems
-- closer to the Ada semantics. Build a full type declaration
-- tree for the derived type using the implicit base type as
-- the defining identifier. The build a subtype declaration
-- tree which applies the constraint (if any) have it replace
-- the derived type declaration.
Literal := First_Literal (Parent_Type);
Literals_List := New_List;
while Present (Literal)
and then Ekind (Literal) = E_Enumeration_Literal
loop
-- Literals of the derived type have the same representation as
-- those of the parent type, but this representation can be
-- overridden by an explicit representation clause. Indicate
-- that there is no explicit representation given yet. These
-- derived literals are implicit operations of the new type,
-- and can be overridden by explicit ones.
if Nkind (Literal) = N_Defining_Character_Literal then
New_Lit :=
Make_Defining_Character_Literal (Loc, Chars (Literal));
else
New_Lit := Make_Defining_Identifier (Loc, Chars (Literal));
end if;
Set_Ekind (New_Lit, E_Enumeration_Literal);
Set_Enumeration_Pos (New_Lit, Enumeration_Pos (Literal));
Set_Enumeration_Rep (New_Lit, Enumeration_Rep (Literal));
Set_Enumeration_Rep_Expr (New_Lit, Empty);
Set_Alias (New_Lit, Literal);
Set_Is_Known_Valid (New_Lit, True);
Append (New_Lit, Literals_List);
Next_Literal (Literal);
end loop;
Implicit_Base :=
Make_Defining_Identifier (Sloc (Derived_Type),
New_External_Name (Chars (Derived_Type), 'B'));
-- Indicate the proper nature of the derived type. This must
-- be done before analysis of the literals, to recognize cases
-- when a literal may be hidden by a previous explicit function
-- definition (cf. c83031a).
Set_Ekind (Derived_Type, E_Enumeration_Subtype);
Set_Etype (Derived_Type, Implicit_Base);
Type_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => Implicit_Base,
Discriminant_Specifications => No_List,
Type_Definition =>
Make_Enumeration_Type_Definition (Loc, Literals_List));
Mark_Rewrite_Insertion (Type_Decl);
Insert_Before (N, Type_Decl);
Analyze (Type_Decl);
-- After the implicit base is analyzed its Etype needs to be changed
-- to reflect the fact that it is derived from the parent type which
-- was ignored during analysis. We also set the size at this point.
Set_Etype (Implicit_Base, Parent_Type);
Set_Size_Info (Implicit_Base, Parent_Type);
Set_RM_Size (Implicit_Base, RM_Size (Parent_Type));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Type));
Set_Has_Non_Standard_Rep
(Implicit_Base, Has_Non_Standard_Rep
(Parent_Type));
Set_Has_Delayed_Freeze (Implicit_Base);
-- Process the subtype indication including a validation check
-- on the constraint, if any. If a constraint is given, its bounds
-- must be implicitly converted to the new type.
if Nkind (Indic) = N_Subtype_Indication then
declare
R : constant Node_Id :=
Range_Expression (Constraint (Indic));
begin
if Nkind (R) = N_Range then
Hi := Build_Scalar_Bound
(High_Bound (R), Parent_Type, Implicit_Base);
Lo := Build_Scalar_Bound
(Low_Bound (R), Parent_Type, Implicit_Base);
else
-- Constraint is a Range attribute. Replace with the
-- explicit mention of the bounds of the prefix, which must
-- be a subtype.
Analyze (Prefix (R));
Hi :=
Convert_To (Implicit_Base,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Last,
Prefix =>
New_Occurrence_Of (Entity (Prefix (R)), Loc)));
Lo :=
Convert_To (Implicit_Base,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_First,
Prefix =>
New_Occurrence_Of (Entity (Prefix (R)), Loc)));
end if;
end;
else
Hi :=
Build_Scalar_Bound
(Type_High_Bound (Parent_Type),
Parent_Type, Implicit_Base);
Lo :=
Build_Scalar_Bound
(Type_Low_Bound (Parent_Type),
Parent_Type, Implicit_Base);
end if;
Rang_Expr :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
-- If we constructed a default range for the case where no range
-- was given, then the expressions in the range must not freeze
-- since they do not correspond to expressions in the source.
if Nkind (Indic) /= N_Subtype_Indication then
Set_Must_Not_Freeze (Lo);
Set_Must_Not_Freeze (Hi);
Set_Must_Not_Freeze (Rang_Expr);
end if;
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Implicit_Base, Loc),
Constraint =>
Make_Range_Constraint (Loc,
Range_Expression => Rang_Expr))));
Analyze (N);
-- If pragma Discard_Names applies on the first subtype of the
-- parent type, then it must be applied on this subtype as well.
if Einfo.Discard_Names (First_Subtype (Parent_Type)) then
Set_Discard_Names (Derived_Type);
end if;
-- Apply a range check. Since this range expression doesn't have an
-- Etype, we have to specifically pass the Source_Typ parameter. Is
-- this right???
if Nkind (Indic) = N_Subtype_Indication then
Apply_Range_Check (Range_Expression (Constraint (Indic)),
Parent_Type,
Source_Typ => Entity (Subtype_Mark (Indic)));
end if;
end if;
end Build_Derived_Enumeration_Type;
--------------------------------
-- Build_Derived_Numeric_Type --
--------------------------------
procedure Build_Derived_Numeric_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Tdef : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Tdef);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
No_Constraint : constant Boolean := Nkind (Indic) /=
N_Subtype_Indication;
Implicit_Base : Entity_Id;
Lo : Node_Id;
Hi : Node_Id;
begin
-- Process the subtype indication including a validation check on
-- the constraint if any.
Discard_Node (Process_Subtype (Indic, N));
-- Introduce an implicit base type for the derived type even if there
-- is no constraint attached to it, since this seems closer to the Ada
-- semantics.
Implicit_Base :=
Create_Itype (Ekind (Parent_Base), N, Derived_Type, 'B');
Set_Etype (Implicit_Base, Parent_Base);
Set_Ekind (Implicit_Base, Ekind (Parent_Base));
Set_Size_Info (Implicit_Base, Parent_Base);
Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Parent_Base));
Set_Parent (Implicit_Base, Parent (Derived_Type));
if Is_Discrete_Or_Fixed_Point_Type (Parent_Base) then
Set_RM_Size (Implicit_Base, RM_Size (Parent_Base));
end if;
Set_Has_Delayed_Freeze (Implicit_Base);
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
Set_Scalar_Range (Implicit_Base,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
if Has_Infinities (Parent_Base) then
Set_Includes_Infinities (Scalar_Range (Implicit_Base));
end if;
-- The Derived_Type, which is the entity of the declaration, is a
-- subtype of the implicit base. Its Ekind is a subtype, even in the
-- absence of an explicit constraint.
Set_Etype (Derived_Type, Implicit_Base);
-- If we did not have a constraint, then the Ekind is set from the
-- parent type (otherwise Process_Subtype has set the bounds)
if No_Constraint then
Set_Ekind (Derived_Type, Subtype_Kind (Ekind (Parent_Type)));
end if;
-- If we did not have a range constraint, then set the range from the
-- parent type. Otherwise, the call to Process_Subtype has set the
-- bounds.
if No_Constraint
or else not Has_Range_Constraint (Indic)
then
Set_Scalar_Range (Derived_Type,
Make_Range (Loc,
Low_Bound => New_Copy_Tree (Type_Low_Bound (Parent_Type)),
High_Bound => New_Copy_Tree (Type_High_Bound (Parent_Type))));
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
if Has_Infinities (Parent_Type) then
Set_Includes_Infinities (Scalar_Range (Derived_Type));
end if;
end if;
-- Set remaining type-specific fields, depending on numeric type
if Is_Modular_Integer_Type (Parent_Type) then
Set_Modulus (Implicit_Base, Modulus (Parent_Base));
Set_Non_Binary_Modulus
(Implicit_Base, Non_Binary_Modulus (Parent_Base));
elsif Is_Floating_Point_Type (Parent_Type) then
-- Digits of base type is always copied from the digits value of
-- the parent base type, but the digits of the derived type will
-- already have been set if there was a constraint present.
Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
Set_Vax_Float (Implicit_Base, Vax_Float (Parent_Base));
if No_Constraint then
Set_Digits_Value (Derived_Type, Digits_Value (Parent_Type));
end if;
elsif Is_Fixed_Point_Type (Parent_Type) then
-- Small of base type and derived type are always copied from the
-- parent base type, since smalls never change. The delta of the
-- base type is also copied from the parent base type. However the
-- delta of the derived type will have been set already if a
-- constraint was present.
Set_Small_Value (Derived_Type, Small_Value (Parent_Base));
Set_Small_Value (Implicit_Base, Small_Value (Parent_Base));
Set_Delta_Value (Implicit_Base, Delta_Value (Parent_Base));
if No_Constraint then
Set_Delta_Value (Derived_Type, Delta_Value (Parent_Type));
end if;
-- The scale and machine radix in the decimal case are always
-- copied from the parent base type.
if Is_Decimal_Fixed_Point_Type (Parent_Type) then
Set_Scale_Value (Derived_Type, Scale_Value (Parent_Base));
Set_Scale_Value (Implicit_Base, Scale_Value (Parent_Base));
Set_Machine_Radix_10
(Derived_Type, Machine_Radix_10 (Parent_Base));
Set_Machine_Radix_10
(Implicit_Base, Machine_Radix_10 (Parent_Base));
Set_Digits_Value (Implicit_Base, Digits_Value (Parent_Base));
if No_Constraint then
Set_Digits_Value (Derived_Type, Digits_Value (Parent_Base));
else
-- the analysis of the subtype_indication sets the
-- digits value of the derived type.
null;
end if;
end if;
end if;
-- The type of the bounds is that of the parent type, and they
-- must be converted to the derived type.
Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
-- The implicit_base should be frozen when the derived type is frozen,
-- but note that it is used in the conversions of the bounds. For fixed
-- types we delay the determination of the bounds until the proper
-- freezing point. For other numeric types this is rejected by GCC, for
-- reasons that are currently unclear (???), so we choose to freeze the
-- implicit base now. In the case of integers and floating point types
-- this is harmless because subsequent representation clauses cannot
-- affect anything, but it is still baffling that we cannot use the
-- same mechanism for all derived numeric types.
if Is_Fixed_Point_Type (Parent_Type) then
Conditional_Delay (Implicit_Base, Parent_Type);
else
Freeze_Before (N, Implicit_Base);
end if;
end Build_Derived_Numeric_Type;
--------------------------------
-- Build_Derived_Private_Type --
--------------------------------
procedure Build_Derived_Private_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True)
is
Der_Base : Entity_Id;
Discr : Entity_Id;
Full_Decl : Node_Id := Empty;
Full_Der : Entity_Id;
Full_P : Entity_Id;
Last_Discr : Entity_Id;
Par_Scope : constant Entity_Id := Scope (Base_Type (Parent_Type));
Swapped : Boolean := False;
procedure Copy_And_Build;
-- Copy derived type declaration, replace parent with its full view,
-- and analyze new declaration.
--------------------
-- Copy_And_Build --
--------------------
procedure Copy_And_Build is
Full_N : Node_Id;
begin
if Ekind (Parent_Type) in Record_Kind
or else
(Ekind (Parent_Type) in Enumeration_Kind
and then Root_Type (Parent_Type) /= Standard_Character
and then Root_Type (Parent_Type) /= Standard_Wide_Character
and then Root_Type (Parent_Type) /= Standard_Wide_Wide_Character
and then not Is_Generic_Type (Root_Type (Parent_Type)))
then
Full_N := New_Copy_Tree (N);
Insert_After (N, Full_N);
Build_Derived_Type (
Full_N, Parent_Type, Full_Der, True, Derive_Subps => False);
else
Build_Derived_Type (
N, Parent_Type, Full_Der, True, Derive_Subps => False);
end if;
end Copy_And_Build;
-- Start of processing for Build_Derived_Private_Type
begin
if Is_Tagged_Type (Parent_Type) then
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
return;
elsif Has_Discriminants (Parent_Type) then
if Present (Full_View (Parent_Type)) then
if not Is_Completion then
-- Copy declaration for subsequent analysis, to provide a
-- completion for what is a private declaration. Indicate that
-- the full type is internally generated.
Full_Decl := New_Copy_Tree (N);
Full_Der := New_Copy (Derived_Type);
Set_Comes_From_Source (Full_Decl, False);
Set_Comes_From_Source (Full_Der, False);
Insert_After (N, Full_Decl);
else
-- If this is a completion, the full view being built is
-- itself private. We build a subtype of the parent with
-- the same constraints as this full view, to convey to the
-- back end the constrained components and the size of this
-- subtype. If the parent is constrained, its full view can
-- serve as the underlying full view of the derived type.
if No (Discriminant_Specifications (N)) then
if Nkind (Subtype_Indication (Type_Definition (N))) =
N_Subtype_Indication
then
Build_Underlying_Full_View (N, Derived_Type, Parent_Type);
elsif Is_Constrained (Full_View (Parent_Type)) then
Set_Underlying_Full_View (Derived_Type,
Full_View (Parent_Type));
end if;
else
-- If there are new discriminants, the parent subtype is
-- constrained by them, but it is not clear how to build
-- the underlying_full_view in this case ???
null;
end if;
end if;
end if;
-- Build partial view of derived type from partial view of parent
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
if Present (Full_View (Parent_Type))
and then not Is_Completion
then
if not In_Open_Scopes (Par_Scope)
or else not In_Same_Source_Unit (N, Parent_Type)
then
-- Swap partial and full views temporarily
Install_Private_Declarations (Par_Scope);
Install_Visible_Declarations (Par_Scope);
Swapped := True;
end if;
-- Build full view of derived type from full view of parent which
-- is now installed. Subprograms have been derived on the partial
-- view, the completion does not derive them anew.
if not Is_Tagged_Type (Parent_Type) then
-- If the parent is itself derived from another private type,
-- installing the private declarations has not affected its
-- privacy status, so use its own full view explicitly.
if Is_Private_Type (Parent_Type) then
Build_Derived_Record_Type
(Full_Decl, Full_View (Parent_Type), Full_Der, False);
else
Build_Derived_Record_Type
(Full_Decl, Parent_Type, Full_Der, False);
end if;
else
-- If full view of parent is tagged, the completion
-- inherits the proper primitive operations.
Set_Defining_Identifier (Full_Decl, Full_Der);
Build_Derived_Record_Type
(Full_Decl, Parent_Type, Full_Der, Derive_Subps);
Set_Analyzed (Full_Decl);
end if;
if Swapped then
Uninstall_Declarations (Par_Scope);
if In_Open_Scopes (Par_Scope) then
Install_Visible_Declarations (Par_Scope);
end if;
end if;
Der_Base := Base_Type (Derived_Type);
Set_Full_View (Derived_Type, Full_Der);
Set_Full_View (Der_Base, Base_Type (Full_Der));
-- Copy the discriminant list from full view to the partial views
-- (base type and its subtype). Gigi requires that the partial
-- and full views have the same discriminants.
-- Note that since the partial view is pointing to discriminants
-- in the full view, their scope will be that of the full view.
-- This might cause some front end problems and need
-- adjustment???
Discr := First_Discriminant (Base_Type (Full_Der));
Set_First_Entity (Der_Base, Discr);
loop
Last_Discr := Discr;
Next_Discriminant (Discr);
exit when No (Discr);
end loop;
Set_Last_Entity (Der_Base, Last_Discr);
Set_First_Entity (Derived_Type, First_Entity (Der_Base));
Set_Last_Entity (Derived_Type, Last_Entity (Der_Base));
Set_Stored_Constraint (Full_Der, Stored_Constraint (Derived_Type));
else
-- If this is a completion, the derived type stays private
-- and there is no need to create a further full view, except
-- in the unusual case when the derivation is nested within a
-- child unit, see below.
null;
end if;
elsif Present (Full_View (Parent_Type))
and then Has_Discriminants (Full_View (Parent_Type))
then
if Has_Unknown_Discriminants (Parent_Type)
and then Nkind (Subtype_Indication (Type_Definition (N)))
= N_Subtype_Indication
then
Error_Msg_N
("cannot constrain type with unknown discriminants",
Subtype_Indication (Type_Definition (N)));
return;
end if;
-- If full view of parent is a record type, Build full view as
-- a derivation from the parent's full view. Partial view remains
-- private. For code generation and linking, the full view must
-- have the same public status as the partial one. This full view
-- is only needed if the parent type is in an enclosing scope, so
-- that the full view may actually become visible, e.g. in a child
-- unit. This is both more efficient, and avoids order of freezing
-- problems with the added entities.
if not Is_Private_Type (Full_View (Parent_Type))
and then (In_Open_Scopes (Scope (Parent_Type)))
then
Full_Der := Make_Defining_Identifier (Sloc (Derived_Type),
Chars (Derived_Type));
Set_Is_Itype (Full_Der);
Set_Has_Private_Declaration (Full_Der);
Set_Has_Private_Declaration (Derived_Type);
Set_Associated_Node_For_Itype (Full_Der, N);
Set_Parent (Full_Der, Parent (Derived_Type));
Set_Full_View (Derived_Type, Full_Der);
Set_Is_Public (Full_Der, Is_Public (Derived_Type));
Full_P := Full_View (Parent_Type);
Exchange_Declarations (Parent_Type);
Copy_And_Build;
Exchange_Declarations (Full_P);
else
Build_Derived_Record_Type
(N, Full_View (Parent_Type), Derived_Type,
Derive_Subps => False);
end if;
-- In any case, the primitive operations are inherited from
-- the parent type, not from the internal full view.
Set_Etype (Base_Type (Derived_Type), Base_Type (Parent_Type));
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
else
-- Untagged type, No discriminants on either view
if Nkind (Subtype_Indication (Type_Definition (N))) =
N_Subtype_Indication
then
Error_Msg_N
("illegal constraint on type without discriminants", N);
end if;
if Present (Discriminant_Specifications (N))
and then Present (Full_View (Parent_Type))
and then not Is_Tagged_Type (Full_View (Parent_Type))
then
Error_Msg_N
("cannot add discriminants to untagged type", N);
end if;
Set_Stored_Constraint (Derived_Type, No_Elist);
Set_Is_Constrained (Derived_Type, Is_Constrained (Parent_Type));
Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
Set_Has_Controlled_Component
(Derived_Type, Has_Controlled_Component
(Parent_Type));
-- Direct controlled types do not inherit Finalize_Storage_Only flag
if not Is_Controlled (Parent_Type) then
Set_Finalize_Storage_Only
(Base_Type (Derived_Type), Finalize_Storage_Only (Parent_Type));
end if;
-- Construct the implicit full view by deriving from full view of
-- the parent type. In order to get proper visibility, we install
-- the parent scope and its declarations.
-- ??? if the parent is untagged private and its completion is
-- tagged, this mechanism will not work because we cannot derive
-- from the tagged full view unless we have an extension
if Present (Full_View (Parent_Type))
and then not Is_Tagged_Type (Full_View (Parent_Type))
and then not Is_Completion
then
Full_Der :=
Make_Defining_Identifier (Sloc (Derived_Type),
Chars => Chars (Derived_Type));
Set_Is_Itype (Full_Der);
Set_Has_Private_Declaration (Full_Der);
Set_Has_Private_Declaration (Derived_Type);
Set_Associated_Node_For_Itype (Full_Der, N);
Set_Parent (Full_Der, Parent (Derived_Type));
Set_Full_View (Derived_Type, Full_Der);
if not In_Open_Scopes (Par_Scope) then
Install_Private_Declarations (Par_Scope);
Install_Visible_Declarations (Par_Scope);
Copy_And_Build;
Uninstall_Declarations (Par_Scope);
-- If parent scope is open and in another unit, and parent has a
-- completion, then the derivation is taking place in the visible
-- part of a child unit. In that case retrieve the full view of
-- the parent momentarily.
elsif not In_Same_Source_Unit (N, Parent_Type) then
Full_P := Full_View (Parent_Type);
Exchange_Declarations (Parent_Type);
Copy_And_Build;
Exchange_Declarations (Full_P);
-- Otherwise it is a local derivation
else
Copy_And_Build;
end if;
Set_Scope (Full_Der, Current_Scope);
Set_Is_First_Subtype (Full_Der,
Is_First_Subtype (Derived_Type));
Set_Has_Size_Clause (Full_Der, False);
Set_Has_Alignment_Clause (Full_Der, False);
Set_Next_Entity (Full_Der, Empty);
Set_Has_Delayed_Freeze (Full_Der);
Set_Is_Frozen (Full_Der, False);
Set_Freeze_Node (Full_Der, Empty);
Set_Depends_On_Private (Full_Der,
Has_Private_Component (Full_Der));
Set_Public_Status (Full_Der);
end if;
end if;
Set_Has_Unknown_Discriminants (Derived_Type,
Has_Unknown_Discriminants (Parent_Type));
if Is_Private_Type (Derived_Type) then
Set_Private_Dependents (Derived_Type, New_Elmt_List);
end if;
if Is_Private_Type (Parent_Type)
and then Base_Type (Parent_Type) = Parent_Type
and then In_Open_Scopes (Scope (Parent_Type))
then
Append_Elmt (Derived_Type, Private_Dependents (Parent_Type));
if Is_Child_Unit (Scope (Current_Scope))
and then Is_Completion
and then In_Private_Part (Current_Scope)
and then Scope (Parent_Type) /= Current_Scope
then
-- This is the unusual case where a type completed by a private
-- derivation occurs within a package nested in a child unit,
-- and the parent is declared in an ancestor. In this case, the
-- full view of the parent type will become visible in the body
-- of the enclosing child, and only then will the current type
-- be possibly non-private. We build a underlying full view that
-- will be installed when the enclosing child body is compiled.
declare
IR : constant Node_Id := Make_Itype_Reference (Sloc (N));
begin
Full_Der :=
Make_Defining_Identifier (Sloc (Derived_Type),
Chars (Derived_Type));
Set_Is_Itype (Full_Der);
Set_Itype (IR, Full_Der);
Insert_After (N, IR);
-- The full view will be used to swap entities on entry/exit
-- to the body, and must appear in the entity list for the
-- package.
Append_Entity (Full_Der, Scope (Derived_Type));
Set_Has_Private_Declaration (Full_Der);
Set_Has_Private_Declaration (Derived_Type);
Set_Associated_Node_For_Itype (Full_Der, N);
Set_Parent (Full_Der, Parent (Derived_Type));
Full_P := Full_View (Parent_Type);
Exchange_Declarations (Parent_Type);
Copy_And_Build;
Exchange_Declarations (Full_P);
Set_Underlying_Full_View (Derived_Type, Full_Der);
end;
end if;
end if;
end Build_Derived_Private_Type;
-------------------------------
-- Build_Derived_Record_Type --
-------------------------------
-- 1. INTRODUCTION
-- Ideally we would like to use the same model of type derivation for
-- tagged and untagged record types. Unfortunately this is not quite
-- possible because the semantics of representation clauses is different
-- for tagged and untagged records under inheritance. Consider the
-- following:
-- type R (...) is [tagged] record ... end record;
-- type T (...) is new R (...) [with ...];
-- The representation clauses of T can specify a completely different
-- record layout from R's. Hence the same component can be placed in
-- two very different positions in objects of type T and R. If R and T
-- are tagged types, representation clauses for T can only specify the
-- layout of non inherited components, thus components that are common
-- in R and T have the same position in objects of type R and T.
-- This has two implications. The first is that the entire tree for R's
-- declaration needs to be copied for T in the untagged case, so that T
-- can be viewed as a record type of its own with its own representation
-- clauses. The second implication is the way we handle discriminants.
-- Specifically, in the untagged case we need a way to communicate to Gigi
-- what are the real discriminants in the record, while for the semantics
-- we need to consider those introduced by the user to rename the
-- discriminants in the parent type. This is handled by introducing the
-- notion of stored discriminants. See below for more.
-- Fortunately the way regular components are inherited can be handled in
-- the same way in tagged and untagged types.
-- To complicate things a bit more the private view of a private extension
-- cannot be handled in the same way as the full view (for one thing the
-- semantic rules are somewhat different). We will explain what differs
-- below.
-- 2. DISCRIMINANTS UNDER INHERITANCE
-- The semantic rules governing the discriminants of derived types are
-- quite subtle.
-- type Derived_Type_Name [KNOWN_DISCRIMINANT_PART] is new
-- [abstract] Parent_Type_Name [CONSTRAINT] [RECORD_EXTENSION_PART]
-- If parent type has discriminants, then the discriminants that are
-- declared in the derived type are [3.4 (11)]:
-- o The discriminants specified by a new KNOWN_DISCRIMINANT_PART, if
-- there is one;
-- o Otherwise, each discriminant of the parent type (implicitly declared
-- in the same order with the same specifications). In this case, the
-- discriminants are said to be "inherited", or if unknown in the parent
-- are also unknown in the derived type.
-- Furthermore if a KNOWN_DISCRIMINANT_PART is provided, then [3.7(13-18)]:
-- o The parent subtype shall be constrained;
-- o If the parent type is not a tagged type, then each discriminant of
-- the derived type shall be used in the constraint defining a parent
-- subtype [Implementation note: this ensures that the new discriminant
-- can share storage with an existing discriminant.].
-- For the derived type each discriminant of the parent type is either
-- inherited, constrained to equal some new discriminant of the derived
-- type, or constrained to the value of an expression.
-- When inherited or constrained to equal some new discriminant, the
-- parent discriminant and the discriminant of the derived type are said
-- to "correspond".
-- If a discriminant of the parent type is constrained to a specific value
-- in the derived type definition, then the discriminant is said to be
-- "specified" by that derived type definition.
-- 3. DISCRIMINANTS IN DERIVED UNTAGGED RECORD TYPES
-- We have spoken about stored discriminants in point 1 (introduction)
-- above. There are two sort of stored discriminants: implicit and
-- explicit. As long as the derived type inherits the same discriminants as
-- the root record type, stored discriminants are the same as regular
-- discriminants, and are said to be implicit. However, if any discriminant
-- in the root type was renamed in the derived type, then the derived
-- type will contain explicit stored discriminants. Explicit stored
-- discriminants are discriminants in addition to the semantically visible
-- discriminants defined for the derived type. Stored discriminants are
-- used by Gigi to figure out what are the physical discriminants in
-- objects of the derived type (see precise definition in einfo.ads).
-- As an example, consider the following:
-- type R (D1, D2, D3 : Int) is record ... end record;
-- type T1 is new R;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1);
-- type T3 is new T2;
-- type T4 (Y : Int) is new T3 (Y, 99);
-- The following table summarizes the discriminants and stored
-- discriminants in R and T1 through T4.
-- Type Discrim Stored Discrim Comment
-- R (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in R
-- T1 (D1, D2, D3) (D1, D2, D3) Girder discrims implicit in T1
-- T2 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T2
-- T3 (X1, X2) (D1, D2, D3) Girder discrims EXPLICIT in T3
-- T4 (Y) (D1, D2, D3) Girder discrims EXPLICIT in T4
-- Field Corresponding_Discriminant (abbreviated CD below) allows us to
-- find the corresponding discriminant in the parent type, while
-- Original_Record_Component (abbreviated ORC below), the actual physical
-- component that is renamed. Finally the field Is_Completely_Hidden
-- (abbreviated ICH below) is set for all explicit stored discriminants
-- (see einfo.ads for more info). For the above example this gives:
-- Discrim CD ORC ICH
-- ^^^^^^^ ^^ ^^^ ^^^
-- D1 in R empty itself no
-- D2 in R empty itself no
-- D3 in R empty itself no
-- D1 in T1 D1 in R itself no
-- D2 in T1 D2 in R itself no
-- D3 in T1 D3 in R itself no
-- X1 in T2 D3 in T1 D3 in T2 no
-- X2 in T2 D1 in T1 D1 in T2 no
-- D1 in T2 empty itself yes
-- D2 in T2 empty itself yes
-- D3 in T2 empty itself yes
-- X1 in T3 X1 in T2 D3 in T3 no
-- X2 in T3 X2 in T2 D1 in T3 no
-- D1 in T3 empty itself yes
-- D2 in T3 empty itself yes
-- D3 in T3 empty itself yes
-- Y in T4 X1 in T3 D3 in T3 no
-- D1 in T3 empty itself yes
-- D2 in T3 empty itself yes
-- D3 in T3 empty itself yes
-- 4. DISCRIMINANTS IN DERIVED TAGGED RECORD TYPES
-- Type derivation for tagged types is fairly straightforward. if no
-- discriminants are specified by the derived type, these are inherited
-- from the parent. No explicit stored discriminants are ever necessary.
-- The only manipulation that is done to the tree is that of adding a
-- _parent field with parent type and constrained to the same constraint
-- specified for the parent in the derived type definition. For instance:
-- type R (D1, D2, D3 : Int) is tagged record ... end record;
-- type T1 is new R with null record;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with null record;
-- are changed into:
-- type T1 (D1, D2, D3 : Int) is new R (D1, D2, D3) with record
-- _parent : R (D1, D2, D3);
-- end record;
-- type T2 (X1, X2: Int) is new T1 (X2, 88, X1) with record
-- _parent : T1 (X2, 88, X1);
-- end record;
-- The discriminants actually present in R, T1 and T2 as well as their CD,
-- ORC and ICH fields are:
-- Discrim CD ORC ICH
-- ^^^^^^^ ^^ ^^^ ^^^
-- D1 in R empty itself no
-- D2 in R empty itself no
-- D3 in R empty itself no
-- D1 in T1 D1 in R D1 in R no
-- D2 in T1 D2 in R D2 in R no
-- D3 in T1 D3 in R D3 in R no
-- X1 in T2 D3 in T1 D3 in R no
-- X2 in T2 D1 in T1 D1 in R no
-- 5. FIRST TRANSFORMATION FOR DERIVED RECORDS
--
-- Regardless of whether we dealing with a tagged or untagged type
-- we will transform all derived type declarations of the form
--
-- type T is new R (...) [with ...];
-- or
-- subtype S is R (...);
-- type T is new S [with ...];
-- into
-- type BT is new R [with ...];
-- subtype T is BT (...);
--
-- That is, the base derived type is constrained only if it has no
-- discriminants. The reason for doing this is that GNAT's semantic model
-- assumes that a base type with discriminants is unconstrained.
--
-- Note that, strictly speaking, the above transformation is not always
-- correct. Consider for instance the following excerpt from ACVC b34011a:
--
-- procedure B34011A is
-- type REC (D : integer := 0) is record
-- I : Integer;
-- end record;
-- package P is
-- type T6 is new Rec;
-- function F return T6;
-- end P;
-- use P;
-- package Q6 is
-- type U is new T6 (Q6.F.I); -- ERROR: Q6.F.
-- end Q6;
--
-- The definition of Q6.U is illegal. However transforming Q6.U into
-- type BaseU is new T6;
-- subtype U is BaseU (Q6.F.I)
-- turns U into a legal subtype, which is incorrect. To avoid this problem
-- we always analyze the constraint (in this case (Q6.F.I)) before applying
-- the transformation described above.
-- There is another instance where the above transformation is incorrect.
-- Consider:
-- package Pack is
-- type Base (D : Integer) is tagged null record;
-- procedure P (X : Base);
-- type Der is new Base (2) with null record;
-- procedure P (X : Der);
-- end Pack;
-- Then the above transformation turns this into
-- type Der_Base is new Base with null record;
-- -- procedure P (X : Base) is implicitly inherited here
-- -- as procedure P (X : Der_Base).
-- subtype Der is Der_Base (2);
-- procedure P (X : Der);
-- -- The overriding of P (X : Der_Base) is illegal since we
-- -- have a parameter conformance problem.
-- To get around this problem, after having semantically processed Der_Base
-- and the rewritten subtype declaration for Der, we copy Der_Base field
-- Discriminant_Constraint from Der so that when parameter conformance is
-- checked when P is overridden, no semantic errors are flagged.
-- 6. SECOND TRANSFORMATION FOR DERIVED RECORDS
-- Regardless of whether we are dealing with a tagged or untagged type
-- we will transform all derived type declarations of the form
-- type R (D1, .., Dn : ...) is [tagged] record ...;
-- type T is new R [with ...];
-- into
-- type T (D1, .., Dn : ...) is new R (D1, .., Dn) [with ...];
-- The reason for such transformation is that it allows us to implement a
-- very clean form of component inheritance as explained below.
-- Note that this transformation is not achieved by direct tree rewriting
-- and manipulation, but rather by redoing the semantic actions that the
-- above transformation will entail. This is done directly in routine
-- Inherit_Components.
-- 7. TYPE DERIVATION AND COMPONENT INHERITANCE
-- In both tagged and untagged derived types, regular non discriminant
-- components are inherited in the derived type from the parent type. In
-- the absence of discriminants component, inheritance is straightforward
-- as components can simply be copied from the parent.
-- If the parent has discriminants, inheriting components constrained with
-- these discriminants requires caution. Consider the following example:
-- type R (D1, D2 : Positive) is [tagged] record
-- S : String (D1 .. D2);
-- end record;
-- type T1 is new R [with null record];
-- type T2 (X : positive) is new R (1, X) [with null record];
-- As explained in 6. above, T1 is rewritten as
-- type T1 (D1, D2 : Positive) is new R (D1, D2) [with null record];
-- which makes the treatment for T1 and T2 identical.
-- What we want when inheriting S, is that references to D1 and D2 in R are
-- replaced with references to their correct constraints, ie D1 and D2 in
-- T1 and 1 and X in T2. So all R's discriminant references are replaced
-- with either discriminant references in the derived type or expressions.
-- This replacement is achieved as follows: before inheriting R's
-- components, a subtype R (D1, D2) for T1 (resp. R (1, X) for T2) is
-- created in the scope of T1 (resp. scope of T2) so that discriminants D1
-- and D2 of T1 are visible (resp. discriminant X of T2 is visible).
-- For T2, for instance, this has the effect of replacing String (D1 .. D2)
-- by String (1 .. X).
-- 8. TYPE DERIVATION IN PRIVATE TYPE EXTENSIONS
-- We explain here the rules governing private type extensions relevant to
-- type derivation. These rules are explained on the following example:
-- type D [(...)] is new A [(...)] with private; <-- partial view
-- type D [(...)] is new P [(...)] with null record; <-- full view
-- Type A is called the ancestor subtype of the private extension.
-- Type P is the parent type of the full view of the private extension. It
-- must be A or a type derived from A.
-- The rules concerning the discriminants of private type extensions are
-- [7.3(10-13)]:
-- o If a private extension inherits known discriminants from the ancestor
-- subtype, then the full view shall also inherit its discriminants from
-- the ancestor subtype and the parent subtype of the full view shall be
-- constrained if and only if the ancestor subtype is constrained.
-- o If a partial view has unknown discriminants, then the full view may
-- define a definite or an indefinite subtype, with or without
-- discriminants.
-- o If a partial view has neither known nor unknown discriminants, then
-- the full view shall define a definite subtype.
-- o If the ancestor subtype of a private extension has constrained
-- discriminants, then the parent subtype of the full view shall impose a
-- statically matching constraint on those discriminants.
-- This means that only the following forms of private extensions are
-- allowed:
-- type D is new A with private; <-- partial view
-- type D is new P with null record; <-- full view
-- If A has no discriminants than P has no discriminants, otherwise P must
-- inherit A's discriminants.
-- type D is new A (...) with private; <-- partial view
-- type D is new P (:::) with null record; <-- full view
-- P must inherit A's discriminants and (...) and (:::) must statically
-- match.
-- subtype A is R (...);
-- type D is new A with private; <-- partial view
-- type D is new P with null record; <-- full view
-- P must have inherited R's discriminants and must be derived from A or
-- any of its subtypes.
-- type D (..) is new A with private; <-- partial view
-- type D (..) is new P [(:::)] with null record; <-- full view
-- No specific constraints on P's discriminants or constraint (:::).
-- Note that A can be unconstrained, but the parent subtype P must either
-- be constrained or (:::) must be present.
-- type D (..) is new A [(...)] with private; <-- partial view
-- type D (..) is new P [(:::)] with null record; <-- full view
-- P's constraints on A's discriminants must statically match those
-- imposed by (...).
-- 9. IMPLEMENTATION OF TYPE DERIVATION FOR PRIVATE EXTENSIONS
-- The full view of a private extension is handled exactly as described
-- above. The model chose for the private view of a private extension is
-- the same for what concerns discriminants (ie they receive the same
-- treatment as in the tagged case). However, the private view of the
-- private extension always inherits the components of the parent base,
-- without replacing any discriminant reference. Strictly speaking this is
-- incorrect. However, Gigi never uses this view to generate code so this
-- is a purely semantic issue. In theory, a set of transformations similar
-- to those given in 5. and 6. above could be applied to private views of
-- private extensions to have the same model of component inheritance as
-- for non private extensions. However, this is not done because it would
-- further complicate private type processing. Semantically speaking, this
-- leaves us in an uncomfortable situation. As an example consider:
-- package Pack is
-- type R (D : integer) is tagged record
-- S : String (1 .. D);
-- end record;
-- procedure P (X : R);
-- type T is new R (1) with private;
-- private
-- type T is new R (1) with null record;
-- end;
-- This is transformed into:
-- package Pack is
-- type R (D : integer) is tagged record
-- S : String (1 .. D);
-- end record;
-- procedure P (X : R);
-- type T is new R (1) with private;
-- private
-- type BaseT is new R with null record;
-- subtype T is BaseT (1);
-- end;
-- (strictly speaking the above is incorrect Ada)
-- From the semantic standpoint the private view of private extension T
-- should be flagged as constrained since one can clearly have
--
-- Obj : T;
--
-- in a unit withing Pack. However, when deriving subprograms for the
-- private view of private extension T, T must be seen as unconstrained
-- since T has discriminants (this is a constraint of the current
-- subprogram derivation model). Thus, when processing the private view of
-- a private extension such as T, we first mark T as unconstrained, we
-- process it, we perform program derivation and just before returning from
-- Build_Derived_Record_Type we mark T as constrained.
-- ??? Are there are other uncomfortable cases that we will have to
-- deal with.
-- 10. RECORD_TYPE_WITH_PRIVATE complications
-- Types that are derived from a visible record type and have a private
-- extension present other peculiarities. They behave mostly like private
-- types, but if they have primitive operations defined, these will not
-- have the proper signatures for further inheritance, because other
-- primitive operations will use the implicit base that we define for
-- private derivations below. This affect subprogram inheritance (see
-- Derive_Subprograms for details). We also derive the implicit base from
-- the base type of the full view, so that the implicit base is a record
-- type and not another private type, This avoids infinite loops.
procedure Build_Derived_Record_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Derive_Subps : Boolean := True)
is
Loc : constant Source_Ptr := Sloc (N);
Parent_Base : Entity_Id;
Type_Def : Node_Id;
Indic : Node_Id;
Discrim : Entity_Id;
Last_Discrim : Entity_Id;
Constrs : Elist_Id;
Discs : Elist_Id := New_Elmt_List;
-- An empty Discs list means that there were no constraints in the
-- subtype indication or that there was an error processing it.
Assoc_List : Elist_Id;
New_Discrs : Elist_Id;
New_Base : Entity_Id;
New_Decl : Node_Id;
New_Indic : Node_Id;
Is_Tagged : constant Boolean := Is_Tagged_Type (Parent_Type);
Discriminant_Specs : constant Boolean :=
Present (Discriminant_Specifications (N));
Private_Extension : constant Boolean :=
(Nkind (N) = N_Private_Extension_Declaration);
Constraint_Present : Boolean;
Has_Interfaces : Boolean := False;
Inherit_Discrims : Boolean := False;
Tagged_Partial_View : Entity_Id;
Save_Etype : Entity_Id;
Save_Discr_Constr : Elist_Id;
Save_Next_Entity : Entity_Id;
begin
if Ekind (Parent_Type) = E_Record_Type_With_Private
and then Present (Full_View (Parent_Type))
and then Has_Discriminants (Parent_Type)
then
Parent_Base := Base_Type (Full_View (Parent_Type));
else
Parent_Base := Base_Type (Parent_Type);
end if;
-- Before we start the previously documented transformations, here is
-- a little fix for size and alignment of tagged types. Normally when
-- we derive type D from type P, we copy the size and alignment of P
-- as the default for D, and in the absence of explicit representation
-- clauses for D, the size and alignment are indeed the same as the
-- parent.
-- But this is wrong for tagged types, since fields may be added,
-- and the default size may need to be larger, and the default
-- alignment may need to be larger.
-- We therefore reset the size and alignment fields in the tagged
-- case. Note that the size and alignment will in any case be at
-- least as large as the parent type (since the derived type has
-- a copy of the parent type in the _parent field)
if Is_Tagged then
Init_Size_Align (Derived_Type);
end if;
-- STEP 0a: figure out what kind of derived type declaration we have
if Private_Extension then
Type_Def := N;
Set_Ekind (Derived_Type, E_Record_Type_With_Private);
else
Type_Def := Type_Definition (N);
-- Ekind (Parent_Base) in not necessarily E_Record_Type since
-- Parent_Base can be a private type or private extension. However,
-- for tagged types with an extension the newly added fields are
-- visible and hence the Derived_Type is always an E_Record_Type.
-- (except that the parent may have its own private fields).
-- For untagged types we preserve the Ekind of the Parent_Base.
if Present (Record_Extension_Part (Type_Def)) then
Set_Ekind (Derived_Type, E_Record_Type);
else
Set_Ekind (Derived_Type, Ekind (Parent_Base));
end if;
end if;
-- Indic can either be an N_Identifier if the subtype indication
-- contains no constraint or an N_Subtype_Indication if the subtype
-- indication has a constraint.
Indic := Subtype_Indication (Type_Def);
Constraint_Present := (Nkind (Indic) = N_Subtype_Indication);
-- Check that the type has visible discriminants. The type may be
-- a private type with unknown discriminants whose full view has
-- discriminants which are invisible.
if Constraint_Present then
if not Has_Discriminants (Parent_Base)
or else
(Has_Unknown_Discriminants (Parent_Base)
and then Is_Private_Type (Parent_Base))
then
Error_Msg_N
("invalid constraint: type has no discriminant",
Constraint (Indic));
Constraint_Present := False;
Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
elsif Is_Constrained (Parent_Type) then
Error_Msg_N
("invalid constraint: parent type is already constrained",
Constraint (Indic));
Constraint_Present := False;
Rewrite (Indic, New_Copy_Tree (Subtype_Mark (Indic)));
end if;
end if;
-- STEP 0b: If needed, apply transformation given in point 5. above
if not Private_Extension
and then Has_Discriminants (Parent_Type)
and then not Discriminant_Specs
and then (Is_Constrained (Parent_Type) or else Constraint_Present)
then
-- First, we must analyze the constraint (see comment in point 5.)
if Constraint_Present then
New_Discrs := Build_Discriminant_Constraints (Parent_Type, Indic);
if Has_Discriminants (Derived_Type)
and then Has_Private_Declaration (Derived_Type)
and then Present (Discriminant_Constraint (Derived_Type))
then
-- Verify that constraints of the full view conform to those
-- given in partial view.
declare
C1, C2 : Elmt_Id;
begin
C1 := First_Elmt (New_Discrs);
C2 := First_Elmt (Discriminant_Constraint (Derived_Type));
while Present (C1) and then Present (C2) loop
if not
Fully_Conformant_Expressions (Node (C1), Node (C2))
then
Error_Msg_N (
"constraint not conformant to previous declaration",
Node (C1));
end if;
Next_Elmt (C1);
Next_Elmt (C2);
end loop;
end;
end if;
end if;
-- Insert and analyze the declaration for the unconstrained base type
New_Base := Create_Itype (Ekind (Derived_Type), N, Derived_Type, 'B');
New_Decl :=
Make_Full_Type_Declaration (Loc,
Defining_Identifier => New_Base,
Type_Definition =>
Make_Derived_Type_Definition (Loc,
Abstract_Present => Abstract_Present (Type_Def),
Subtype_Indication =>
New_Occurrence_Of (Parent_Base, Loc),
Record_Extension_Part =>
Relocate_Node (Record_Extension_Part (Type_Def))));
Set_Parent (New_Decl, Parent (N));
Mark_Rewrite_Insertion (New_Decl);
Insert_Before (N, New_Decl);
-- Note that this call passes False for the Derive_Subps parameter
-- because subprogram derivation is deferred until after creating
-- the subtype (see below).
Build_Derived_Type
(New_Decl, Parent_Base, New_Base,
Is_Completion => True, Derive_Subps => False);
-- ??? This needs re-examination to determine whether the
-- above call can simply be replaced by a call to Analyze.
Set_Analyzed (New_Decl);
-- Insert and analyze the declaration for the constrained subtype
if Constraint_Present then
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint => Relocate_Node (Constraint (Indic)));
else
declare
Constr_List : constant List_Id := New_List;
C : Elmt_Id;
Expr : Node_Id;
begin
C := First_Elmt (Discriminant_Constraint (Parent_Type));
while Present (C) loop
Expr := Node (C);
-- It is safe here to call New_Copy_Tree since
-- Force_Evaluation was called on each constraint in
-- Build_Discriminant_Constraints.
Append (New_Copy_Tree (Expr), To => Constr_List);
Next_Elmt (C);
end loop;
New_Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (New_Base, Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc, Constr_List));
end;
end if;
Rewrite (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Derived_Type,
Subtype_Indication => New_Indic));
Analyze (N);
-- Derivation of subprograms must be delayed until the full subtype
-- has been established to ensure proper overriding of subprograms
-- inherited by full types. If the derivations occurred as part of
-- the call to Build_Derived_Type above, then the check for type
-- conformance would fail because earlier primitive subprograms
-- could still refer to the full type prior the change to the new
-- subtype and hence would not match the new base type created here.
Derive_Subprograms (Parent_Type, Derived_Type);
-- For tagged types the Discriminant_Constraint of the new base itype
-- is inherited from the first subtype so that no subtype conformance
-- problem arise when the first subtype overrides primitive
-- operations inherited by the implicit base type.
if Is_Tagged then
Set_Discriminant_Constraint
(New_Base, Discriminant_Constraint (Derived_Type));
end if;
return;
end if;
-- If we get here Derived_Type will have no discriminants or it will be
-- a discriminated unconstrained base type.
-- STEP 1a: perform preliminary actions/checks for derived tagged types
if Is_Tagged then
-- The parent type is frozen for non-private extensions (RM 13.14(7))
if not Private_Extension then
Freeze_Before (N, Parent_Type);
end if;
-- In Ada 2005 (AI-344), the restriction that a derived tagged type
-- cannot be declared at a deeper level than its parent type is
-- removed. The check on derivation within a generic body is also
-- relaxed, but there's a restriction that a derived tagged type
-- cannot be declared in a generic body if it's derived directly
-- or indirectly from a formal type of that generic.
if Ada_Version >= Ada_05 then
if Present (Enclosing_Generic_Body (Derived_Type)) then
declare
Ancestor_Type : Entity_Id;
begin
-- Check to see if any ancestor of the derived type is a
-- formal type.
Ancestor_Type := Parent_Type;
while not Is_Generic_Type (Ancestor_Type)
and then Etype (Ancestor_Type) /= Ancestor_Type
loop
Ancestor_Type := Etype (Ancestor_Type);
end loop;
-- If the derived type does have a formal type as an
-- ancestor, then it's an error if the derived type is
-- declared within the body of the generic unit that
-- declares the formal type in its generic formal part. It's
-- sufficient to check whether the ancestor type is declared
-- inside the same generic body as the derived type (such as
-- within a nested generic spec), in which case the
-- derivation is legal. If the formal type is declared
-- outside of that generic body, then it's guaranteed that
-- the derived type is declared within the generic body of
-- the generic unit declaring the formal type.
if Is_Generic_Type (Ancestor_Type)
and then Enclosing_Generic_Body (Ancestor_Type) /=
Enclosing_Generic_Body (Derived_Type)
then
Error_Msg_NE
("parent type of& must not be descendant of formal type"
& " of an enclosing generic body",
Indic, Derived_Type);
end if;
end;
end if;
elsif Type_Access_Level (Derived_Type) /=
Type_Access_Level (Parent_Type)
and then not Is_Generic_Type (Derived_Type)
then
if Is_Controlled (Parent_Type) then
Error_Msg_N
("controlled type must be declared at the library level",
Indic);
else
Error_Msg_N
("type extension at deeper accessibility level than parent",
Indic);
end if;
else
declare
GB : constant Node_Id := Enclosing_Generic_Body (Derived_Type);
begin
if Present (GB)
and then GB /= Enclosing_Generic_Body (Parent_Base)
then
Error_Msg_NE
("parent type of& must not be outside generic body"
& " ('R'M 3.9.1(4))",
Indic, Derived_Type);
end if;
end;
end if;
end if;
-- Ada 2005 (AI-251)
if Ada_Version = Ada_05
and then Is_Tagged
then
-- "The declaration of a specific descendant of an interface type
-- freezes the interface type" (RM 13.14).
declare
Iface : Node_Id;
begin
if Is_Non_Empty_List (Interface_List (Type_Def)) then
Iface := First (Interface_List (Type_Def));
while Present (Iface) loop
Freeze_Before (N, Etype (Iface));
Next (Iface);
end loop;
end if;
end;
end if;
-- STEP 1b : preliminary cleanup of the full view of private types
-- If the type is already marked as having discriminants, then it's the
-- completion of a private type or private extension and we need to
-- retain the discriminants from the partial view if the current
-- declaration has Discriminant_Specifications so that we can verify
-- conformance. However, we must remove any existing components that
-- were inherited from the parent (and attached in Copy_And_Swap)
-- because the full type inherits all appropriate components anyway, and
-- we do not want the partial view's components interfering.
if Has_Discriminants (Derived_Type) and then Discriminant_Specs then
Discrim := First_Discriminant (Derived_Type);
loop
Last_Discrim := Discrim;
Next_Discriminant (Discrim);
exit when No (Discrim);
end loop;
Set_Last_Entity (Derived_Type, Last_Discrim);
-- In all other cases wipe out the list of inherited components (even
-- inherited discriminants), it will be properly rebuilt here.
else
Set_First_Entity (Derived_Type, Empty);
Set_Last_Entity (Derived_Type, Empty);
end if;
-- STEP 1c: Initialize some flags for the Derived_Type
-- The following flags must be initialized here so that
-- Process_Discriminants can check that discriminants of tagged types
-- do not have a default initial value and that access discriminants
-- are only specified for limited records. For completeness, these
-- flags are also initialized along with all the other flags below.
-- AI-419: limitedness is not inherited from an interface parent
Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
Set_Is_Limited_Record (Derived_Type,
Is_Limited_Record (Parent_Type)
and then not Is_Interface (Parent_Type));
-- STEP 2a: process discriminants of derived type if any
New_Scope (Derived_Type);
if Discriminant_Specs then
Set_Has_Unknown_Discriminants (Derived_Type, False);
-- The following call initializes fields Has_Discriminants and
-- Discriminant_Constraint, unless we are processing the completion
-- of a private type declaration.
Check_Or_Process_Discriminants (N, Derived_Type);
-- For non-tagged types the constraint on the Parent_Type must be
-- present and is used to rename the discriminants.
if not Is_Tagged and then not Has_Discriminants (Parent_Type) then
Error_Msg_N ("untagged parent must have discriminants", Indic);
elsif not Is_Tagged and then not Constraint_Present then
Error_Msg_N
("discriminant constraint needed for derived untagged records",
Indic);
-- Otherwise the parent subtype must be constrained unless we have a
-- private extension.
elsif not Constraint_Present
and then not Private_Extension
and then not Is_Constrained (Parent_Type)
then
Error_Msg_N
("unconstrained type not allowed in this context", Indic);
elsif Constraint_Present then
-- The following call sets the field Corresponding_Discriminant
-- for the discriminants in the Derived_Type.
Discs := Build_Discriminant_Constraints (Parent_Type, Indic, True);
-- For untagged types all new discriminants must rename
-- discriminants in the parent. For private extensions new
-- discriminants cannot rename old ones (implied by [7.3(13)]).
Discrim := First_Discriminant (Derived_Type);
while Present (Discrim) loop
if not Is_Tagged
and then No (Corresponding_Discriminant (Discrim))
then
Error_Msg_N
("new discriminants must constrain old ones", Discrim);
elsif Private_Extension
and then Present (Corresponding_Discriminant (Discrim))
then
Error_Msg_N
("only static constraints allowed for parent"
& " discriminants in the partial view", Indic);
exit;
end if;
-- If a new discriminant is used in the constraint, then its
-- subtype must be statically compatible with the parent
-- discriminant's subtype (3.7(15)).
if Present (Corresponding_Discriminant (Discrim))
and then
not Subtypes_Statically_Compatible
(Etype (Discrim),
Etype (Corresponding_Discriminant (Discrim)))
then
Error_Msg_N
("subtype must be compatible with parent discriminant",
Discrim);
end if;
Next_Discriminant (Discrim);
end loop;
-- Check whether the constraints of the full view statically
-- match those imposed by the parent subtype [7.3(13)].
if Present (Stored_Constraint (Derived_Type)) then
declare
C1, C2 : Elmt_Id;
begin
C1 := First_Elmt (Discs);
C2 := First_Elmt (Stored_Constraint (Derived_Type));
while Present (C1) and then Present (C2) loop
if not
Fully_Conformant_Expressions (Node (C1), Node (C2))
then
Error_Msg_N (
"not conformant with previous declaration",
Node (C1));
end if;
Next_Elmt (C1);
Next_Elmt (C2);
end loop;
end;
end if;
end if;
-- STEP 2b: No new discriminants, inherit discriminants if any
else
if Private_Extension then
Set_Has_Unknown_Discriminants
(Derived_Type,
Has_Unknown_Discriminants (Parent_Type)
or else Unknown_Discriminants_Present (N));
-- The partial view of the parent may have unknown discriminants,
-- but if the full view has discriminants and the parent type is
-- in scope they must be inherited.
elsif Has_Unknown_Discriminants (Parent_Type)
and then
(not Has_Discriminants (Parent_Type)
or else not In_Open_Scopes (Scope (Parent_Type)))
then
Set_Has_Unknown_Discriminants (Derived_Type);
end if;
if not Has_Unknown_Discriminants (Derived_Type)
and then not Has_Unknown_Discriminants (Parent_Base)
and then Has_Discriminants (Parent_Type)
then
Inherit_Discrims := True;
Set_Has_Discriminants
(Derived_Type, True);
Set_Discriminant_Constraint
(Derived_Type, Discriminant_Constraint (Parent_Base));
end if;
-- The following test is true for private types (remember
-- transformation 5. is not applied to those) and in an error
-- situation.
if Constraint_Present then
Discs := Build_Discriminant_Constraints (Parent_Type, Indic);
end if;
-- For now mark a new derived type as constrained only if it has no
-- discriminants. At the end of Build_Derived_Record_Type we properly
-- set this flag in the case of private extensions. See comments in
-- point 9. just before body of Build_Derived_Record_Type.
Set_Is_Constrained
(Derived_Type,
not (Inherit_Discrims
or else Has_Unknown_Discriminants (Derived_Type)));
end if;
-- STEP 3: initialize fields of derived type
Set_Is_Tagged_Type (Derived_Type, Is_Tagged);
Set_Stored_Constraint (Derived_Type, No_Elist);
-- Ada 2005 (AI-251): Private type-declarations can implement interfaces
-- but cannot be interfaces
if not Private_Extension
and then Ekind (Derived_Type) /= E_Private_Type
and then Ekind (Derived_Type) /= E_Limited_Private_Type
then
Set_Is_Interface (Derived_Type, Interface_Present (Type_Def));
Set_Abstract_Interfaces (Derived_Type, No_Elist);
end if;
-- Fields inherited from the Parent_Type
Set_Discard_Names
(Derived_Type, Einfo.Discard_Names (Parent_Type));
Set_Has_Specified_Layout
(Derived_Type, Has_Specified_Layout (Parent_Type));
Set_Is_Limited_Composite
(Derived_Type, Is_Limited_Composite (Parent_Type));
Set_Is_Limited_Record
(Derived_Type,
Is_Limited_Record (Parent_Type)
and then not Is_Interface (Parent_Type));
Set_Is_Private_Composite
(Derived_Type, Is_Private_Composite (Parent_Type));
-- Fields inherited from the Parent_Base
Set_Has_Controlled_Component
(Derived_Type, Has_Controlled_Component (Parent_Base));
Set_Has_Non_Standard_Rep
(Derived_Type, Has_Non_Standard_Rep (Parent_Base));
Set_Has_Primitive_Operations
(Derived_Type, Has_Primitive_Operations (Parent_Base));
-- Direct controlled types do not inherit Finalize_Storage_Only flag
if not Is_Controlled (Parent_Type) then
Set_Finalize_Storage_Only
(Derived_Type, Finalize_Storage_Only (Parent_Type));
end if;
-- Set fields for private derived types
if Is_Private_Type (Derived_Type) then
Set_Depends_On_Private (Derived_Type, True);
Set_Private_Dependents (Derived_Type, New_Elmt_List);
-- Inherit fields from non private record types. If this is the
-- completion of a derivation from a private type, the parent itself
-- is private, and the attributes come from its full view, which must
-- be present.
else
if Is_Private_Type (Parent_Base)
and then not Is_Record_Type (Parent_Base)
then
Set_Component_Alignment
(Derived_Type, Component_Alignment (Full_View (Parent_Base)));
Set_C_Pass_By_Copy
(Derived_Type, C_Pass_By_Copy (Full_View (Parent_Base)));
else
Set_Component_Alignment
(Derived_Type, Component_Alignment (Parent_Base));
Set_C_Pass_By_Copy
(Derived_Type, C_Pass_By_Copy (Parent_Base));
end if;
end if;
-- Set fields for tagged types
if Is_Tagged then
Set_Primitive_Operations (Derived_Type, New_Elmt_List);
-- All tagged types defined in Ada.Finalization are controlled
if Chars (Scope (Derived_Type)) = Name_Finalization
and then Chars (Scope (Scope (Derived_Type))) = Name_Ada
and then Scope (Scope (Scope (Derived_Type))) = Standard_Standard
then
Set_Is_Controlled (Derived_Type);
else
Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Base));
end if;
Make_Class_Wide_Type (Derived_Type);
Set_Is_Abstract (Derived_Type, Abstract_Present (Type_Def));
if Has_Discriminants (Derived_Type)
and then Constraint_Present
then
Set_Stored_Constraint
(Derived_Type, Expand_To_Stored_Constraint (Parent_Base, Discs));
end if;
-- Ada 2005 (AI-251): Look for the partial view of tagged types
-- declared in the private part. This will be used 1) to check that
-- the set of interfaces in both views is equal, and 2) to complete
-- the derivation of subprograms covering interfaces.
Tagged_Partial_View := Empty;
if Has_Private_Declaration (Derived_Type) then
Tagged_Partial_View := Next_Entity (Derived_Type);
loop
exit when Has_Private_Declaration (Tagged_Partial_View)
and then Full_View (Tagged_Partial_View) = Derived_Type;
Next_Entity (Tagged_Partial_View);
end loop;
end if;
-- Ada 2005 (AI-251): Collect the whole list of implemented
-- interfaces.
if Ada_Version >= Ada_05 then
Set_Abstract_Interfaces (Derived_Type, New_Elmt_List);
if Nkind (N) = N_Private_Extension_Declaration then
Collect_Interfaces (N, Derived_Type);
else
Collect_Interfaces (Type_Definition (N), Derived_Type);
end if;
end if;
else
Set_Is_Packed (Derived_Type, Is_Packed (Parent_Base));
Set_Has_Non_Standard_Rep
(Derived_Type, Has_Non_Standard_Rep (Parent_Base));
end if;
-- STEP 4: Inherit components from the parent base and constrain them.
-- Apply the second transformation described in point 6. above.
if (not Is_Empty_Elmt_List (Discs) or else Inherit_Discrims)
or else not Has_Discriminants (Parent_Type)
or else not Is_Constrained (Parent_Type)
then
Constrs := Discs;
else
Constrs := Discriminant_Constraint (Parent_Type);
end if;
Assoc_List :=
Inherit_Components
(N, Parent_Base, Derived_Type, Is_Tagged, Inherit_Discrims, Constrs);
-- STEP 5a: Copy the parent record declaration for untagged types
if not Is_Tagged then
-- Discriminant_Constraint (Derived_Type) has been properly
-- constructed. Save it and temporarily set it to Empty because we
-- do not want the call to New_Copy_Tree below to mess this list.
if Has_Discriminants (Derived_Type) then
Save_Discr_Constr := Discriminant_Constraint (Derived_Type);
Set_Discriminant_Constraint (Derived_Type, No_Elist);
else
Save_Discr_Constr := No_Elist;
end if;
-- Save the Etype field of Derived_Type. It is correctly set now,
-- but the call to New_Copy tree may remap it to point to itself,
-- which is not what we want. Ditto for the Next_Entity field.
Save_Etype := Etype (Derived_Type);
Save_Next_Entity := Next_Entity (Derived_Type);
-- Assoc_List maps all stored discriminants in the Parent_Base to
-- stored discriminants in the Derived_Type. It is fundamental that
-- no types or itypes with discriminants other than the stored
-- discriminants appear in the entities declared inside
-- Derived_Type, since the back end cannot deal with it.
New_Decl :=
New_Copy_Tree
(Parent (Parent_Base), Map => Assoc_List, New_Sloc => Loc);
-- Restore the fields saved prior to the New_Copy_Tree call
-- and compute the stored constraint.
Set_Etype (Derived_Type, Save_Etype);
Set_Next_Entity (Derived_Type, Save_Next_Entity);
if Has_Discriminants (Derived_Type) then
Set_Discriminant_Constraint
(Derived_Type, Save_Discr_Constr);
Set_Stored_Constraint
(Derived_Type, Expand_To_Stored_Constraint (Parent_Type, Discs));
Replace_Components (Derived_Type, New_Decl);
end if;
-- Insert the new derived type declaration
Rewrite (N, New_Decl);
-- STEP 5b: Complete the processing for record extensions in generics
-- There is no completion for record extensions declared in the
-- parameter part of a generic, so we need to complete processing for
-- these generic record extensions here. The Record_Type_Definition call
-- will change the Ekind of the components from E_Void to E_Component.
elsif Private_Extension and then Is_Generic_Type (Derived_Type) then
Record_Type_Definition (Empty, Derived_Type);
-- STEP 5c: Process the record extension for non private tagged types
elsif not Private_Extension then
-- Add the _parent field in the derived type
Expand_Record_Extension (Derived_Type, Type_Def);
-- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
-- implemented interfaces if we are in expansion mode
if Expander_Active then
Add_Interface_Tag_Components (N, Derived_Type);
end if;
-- Analyze the record extension
Record_Type_Definition
(Record_Extension_Part (Type_Def), Derived_Type);
end if;
End_Scope;
if Etype (Derived_Type) = Any_Type then
return;
end if;
-- Set delayed freeze and then derive subprograms, we need to do
-- this in this order so that derived subprograms inherit the
-- derived freeze if necessary.
Set_Has_Delayed_Freeze (Derived_Type);
if Derive_Subps then
-- Ada 2005 (AI-251): Check if this tagged type implements abstract
-- interfaces
Has_Interfaces := False;
if Is_Tagged_Type (Derived_Type) then
declare
E : Entity_Id;
begin
-- Handle private types
if Present (Full_View (Derived_Type)) then
E := Full_View (Derived_Type);
else
E := Derived_Type;
end if;
loop
if Is_Interface (E)
or else (Present (Abstract_Interfaces (E))
and then
not Is_Empty_Elmt_List (Abstract_Interfaces (E)))
then
Has_Interfaces := True;
exit;
end if;
exit when Etype (E) = E
-- Handle private types
or else (Present (Full_View (Etype (E)))
and then Full_View (Etype (E)) = E)
-- Protect the frontend against wrong source
or else Etype (E) = Derived_Type;
-- Climb to the ancestor type handling private types
if Present (Full_View (Etype (E))) then
E := Full_View (Etype (E));
else
E := Etype (E);
end if;
end loop;
end;
end if;
Derive_Subprograms (Parent_Type, Derived_Type);
-- Ada 2005 (AI-251): Handle tagged types implementing interfaces
if Is_Tagged_Type (Derived_Type)
and then Has_Interfaces
then
-- Ada 2005 (AI-251): If we are analyzing a full view that has
-- no partial view we derive the abstract interface Subprograms
if No (Tagged_Partial_View) then
Derive_Interface_Subprograms (Derived_Type);
-- Ada 2005 (AI-251): if we are analyzing a full view that has
-- a partial view we complete the derivation of the subprograms
else
Complete_Subprograms_Derivation
(Partial_View => Tagged_Partial_View,
Derived_Type => Derived_Type);
end if;
-- Ada 2005 (AI-251): In both cases we check if some of the
-- inherited subprograms cover interface primitives.
declare
Iface_Subp : Entity_Id;
Iface_Subp_Elmt : Elmt_Id;
Prev_Alias : Entity_Id;
Subp : Entity_Id;
Subp_Elmt : Elmt_Id;
begin
Iface_Subp_Elmt :=
First_Elmt (Primitive_Operations (Derived_Type));
while Present (Iface_Subp_Elmt) loop
Iface_Subp := Node (Iface_Subp_Elmt);
-- Look for an abstract interface subprogram
if Is_Abstract (Iface_Subp)
and then Present (Alias (Iface_Subp))
and then Present (DTC_Entity (Alias (Iface_Subp)))
and then Is_Interface
(Scope (DTC_Entity (Alias (Iface_Subp))))
then
-- Look for candidate primitive subprograms of the tagged
-- type that can cover this interface subprogram.
Subp_Elmt :=
First_Elmt (Primitive_Operations (Derived_Type));
while Present (Subp_Elmt) loop
Subp := Node (Subp_Elmt);
if not Is_Abstract (Subp)
and then Chars (Subp) = Chars (Iface_Subp)
and then Type_Conformant (Iface_Subp, Subp)
then
Prev_Alias := Alias (Iface_Subp);
Check_Dispatching_Operation
(Subp => Subp,
Old_Subp => Iface_Subp);
pragma Assert
(Alias (Iface_Subp) = Subp);
pragma Assert
(Abstract_Interface_Alias (Iface_Subp)
= Prev_Alias);
-- Traverse the list of aliased subprograms to link
-- subp with its ultimate aliased subprogram. This
-- avoids problems with the backend.
declare
E : Entity_Id;
begin
E := Alias (Subp);
while Present (Alias (E)) loop
E := Alias (E);
end loop;
Set_Alias (Subp, E);
end;
Set_Has_Delayed_Freeze (Subp);
exit;
end if;
Next_Elmt (Subp_Elmt);
end loop;
end if;
Next_Elmt (Iface_Subp_Elmt);
end loop;
end;
end if;
end if;
-- If we have a private extension which defines a constrained derived
-- type mark as constrained here after we have derived subprograms. See
-- comment on point 9. just above the body of Build_Derived_Record_Type.
if Private_Extension and then Inherit_Discrims then
if Constraint_Present and then not Is_Empty_Elmt_List (Discs) then
Set_Is_Constrained (Derived_Type, True);
Set_Discriminant_Constraint (Derived_Type, Discs);
elsif Is_Constrained (Parent_Type) then
Set_Is_Constrained
(Derived_Type, True);
Set_Discriminant_Constraint
(Derived_Type, Discriminant_Constraint (Parent_Type));
end if;
end if;
-- Update the class_wide type, which shares the now-completed
-- entity list with its specific type.
if Is_Tagged then
Set_First_Entity
(Class_Wide_Type (Derived_Type), First_Entity (Derived_Type));
Set_Last_Entity
(Class_Wide_Type (Derived_Type), Last_Entity (Derived_Type));
end if;
end Build_Derived_Record_Type;
------------------------
-- Build_Derived_Type --
------------------------
procedure Build_Derived_Type
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Is_Completion : Boolean;
Derive_Subps : Boolean := True)
is
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
begin
-- Set common attributes
Set_Scope (Derived_Type, Current_Scope);
Set_Ekind (Derived_Type, Ekind (Parent_Base));
Set_Etype (Derived_Type, Parent_Base);
Set_Has_Task (Derived_Type, Has_Task (Parent_Base));
Set_Size_Info (Derived_Type, Parent_Type);
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
Set_Convention (Derived_Type, Convention (Parent_Type));
Set_Is_Controlled (Derived_Type, Is_Controlled (Parent_Type));
-- The derived type inherits the representation clauses of the parent.
-- However, for a private type that is completed by a derivation, there
-- may be operation attributes that have been specified already (stream
-- attributes and External_Tag) and those must be provided. Finally,
-- if the partial view is a private extension, the representation items
-- of the parent have been inherited already, and should not be chained
-- twice to the derived type.
if Is_Tagged_Type (Parent_Type)
and then Present (First_Rep_Item (Derived_Type))
then
-- The existing items are either operational items or items inherited
-- from a private extension declaration.
declare
Rep : Node_Id;
Found : Boolean := False;
begin
Rep := First_Rep_Item (Derived_Type);
while Present (Rep) loop
if Rep = First_Rep_Item (Parent_Type) then
Found := True;
exit;
else
Rep := Next_Rep_Item (Rep);
end if;
end loop;
if not Found then
Set_Next_Rep_Item
(First_Rep_Item (Derived_Type), First_Rep_Item (Parent_Type));
end if;
end;
else
Set_First_Rep_Item (Derived_Type, First_Rep_Item (Parent_Type));
end if;
case Ekind (Parent_Type) is
when Numeric_Kind =>
Build_Derived_Numeric_Type (N, Parent_Type, Derived_Type);
when Array_Kind =>
Build_Derived_Array_Type (N, Parent_Type, Derived_Type);
when E_Record_Type
| E_Record_Subtype
| Class_Wide_Kind =>
Build_Derived_Record_Type
(N, Parent_Type, Derived_Type, Derive_Subps);
return;
when Enumeration_Kind =>
Build_Derived_Enumeration_Type (N, Parent_Type, Derived_Type);
when Access_Kind =>
Build_Derived_Access_Type (N, Parent_Type, Derived_Type);
when Incomplete_Or_Private_Kind =>
Build_Derived_Private_Type
(N, Parent_Type, Derived_Type, Is_Completion, Derive_Subps);
-- For discriminated types, the derivation includes deriving
-- primitive operations. For others it is done below.
if Is_Tagged_Type (Parent_Type)
or else Has_Discriminants (Parent_Type)
or else (Present (Full_View (Parent_Type))
and then Has_Discriminants (Full_View (Parent_Type)))
then
return;
end if;
when Concurrent_Kind =>
Build_Derived_Concurrent_Type (N, Parent_Type, Derived_Type);
when others =>
raise Program_Error;
end case;
if Etype (Derived_Type) = Any_Type then
return;
end if;
-- Set delayed freeze and then derive subprograms, we need to do this
-- in this order so that derived subprograms inherit the derived freeze
-- if necessary.
Set_Has_Delayed_Freeze (Derived_Type);
if Derive_Subps then
Derive_Subprograms (Parent_Type, Derived_Type);
end if;
Set_Has_Primitive_Operations
(Base_Type (Derived_Type), Has_Primitive_Operations (Parent_Type));
end Build_Derived_Type;
-----------------------
-- Build_Discriminal --
-----------------------
procedure Build_Discriminal (Discrim : Entity_Id) is
D_Minal : Entity_Id;
CR_Disc : Entity_Id;
begin
-- A discriminal has the same name as the discriminant
D_Minal :=
Make_Defining_Identifier (Sloc (Discrim),
Chars => Chars (Discrim));
Set_Ekind (D_Minal, E_In_Parameter);
Set_Mechanism (D_Minal, Default_Mechanism);
Set_Etype (D_Minal, Etype (Discrim));
Set_Discriminal (Discrim, D_Minal);
Set_Discriminal_Link (D_Minal, Discrim);
-- For task types, build at once the discriminants of the corresponding
-- record, which are needed if discriminants are used in entry defaults
-- and in family bounds.
if Is_Concurrent_Type (Current_Scope)
or else Is_Limited_Type (Current_Scope)
then
CR_Disc := Make_Defining_Identifier (Sloc (Discrim), Chars (Discrim));
Set_Ekind (CR_Disc, E_In_Parameter);
Set_Mechanism (CR_Disc, Default_Mechanism);
Set_Etype (CR_Disc, Etype (Discrim));
Set_Discriminal_Link (CR_Disc, Discrim);
Set_CR_Discriminant (Discrim, CR_Disc);
end if;
end Build_Discriminal;
------------------------------------
-- Build_Discriminant_Constraints --
------------------------------------
function Build_Discriminant_Constraints
(T : Entity_Id;
Def : Node_Id;
Derived_Def : Boolean := False) return Elist_Id
is
C : constant Node_Id := Constraint (Def);
Nb_Discr : constant Nat := Number_Discriminants (T);
Discr_Expr : array (1 .. Nb_Discr) of Node_Id := (others => Empty);
-- Saves the expression corresponding to a given discriminant in T
function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat;
-- Return the Position number within array Discr_Expr of a discriminant
-- D within the discriminant list of the discriminated type T.
------------------
-- Pos_Of_Discr --
------------------
function Pos_Of_Discr (T : Entity_Id; D : Entity_Id) return Nat is
Disc : Entity_Id;
begin
Disc := First_Discriminant (T);
for J in Discr_Expr'Range loop
if Disc = D then
return J;
end if;
Next_Discriminant (Disc);
end loop;
-- Note: Since this function is called on discriminants that are
-- known to belong to the discriminated type, falling through the
-- loop with no match signals an internal compiler error.
raise Program_Error;
end Pos_Of_Discr;
-- Declarations local to Build_Discriminant_Constraints
Discr : Entity_Id;
E : Entity_Id;
Elist : constant Elist_Id := New_Elmt_List;
Constr : Node_Id;
Expr : Node_Id;
Id : Node_Id;
Position : Nat;
Found : Boolean;
Discrim_Present : Boolean := False;
-- Start of processing for Build_Discriminant_Constraints
begin
-- The following loop will process positional associations only.
-- For a positional association, the (single) discriminant is
-- implicitly specified by position, in textual order (RM 3.7.2).
Discr := First_Discriminant (T);
Constr := First (Constraints (C));
for D in Discr_Expr'Range loop
exit when Nkind (Constr) = N_Discriminant_Association;
if No (Constr) then
Error_Msg_N ("too few discriminants given in constraint", C);
return New_Elmt_List;
elsif Nkind (Constr) = N_Range
or else (Nkind (Constr) = N_Attribute_Reference
and then
Attribute_Name (Constr) = Name_Range)
then
Error_Msg_N
("a range is not a valid discriminant constraint", Constr);
Discr_Expr (D) := Error;
else
Analyze_And_Resolve (Constr, Base_Type (Etype (Discr)));
Discr_Expr (D) := Constr;
end if;
Next_Discriminant (Discr);
Next (Constr);
end loop;
if No (Discr) and then Present (Constr) then
Error_Msg_N ("too many discriminants given in constraint", Constr);
return New_Elmt_List;
end if;
-- Named associations can be given in any order, but if both positional
-- and named associations are used in the same discriminant constraint,
-- then positional associations must occur first, at their normal
-- position. Hence once a named association is used, the rest of the
-- discriminant constraint must use only named associations.
while Present (Constr) loop
-- Positional association forbidden after a named association
if Nkind (Constr) /= N_Discriminant_Association then
Error_Msg_N ("positional association follows named one", Constr);
return New_Elmt_List;
-- Otherwise it is a named association
else
-- E records the type of the discriminants in the named
-- association. All the discriminants specified in the same name
-- association must have the same type.
E := Empty;
-- Search the list of discriminants in T to see if the simple name
-- given in the constraint matches any of them.
Id := First (Selector_Names (Constr));
while Present (Id) loop
Found := False;
-- If Original_Discriminant is present, we are processing a
-- generic instantiation and this is an instance node. We need
-- to find the name of the corresponding discriminant in the
-- actual record type T and not the name of the discriminant in
-- the generic formal. Example:
--
-- generic
-- type G (D : int) is private;
-- package P is
-- subtype W is G (D => 1);
-- end package;
-- type Rec (X : int) is record ... end record;
-- package Q is new P (G => Rec);
--
-- At the point of the instantiation, formal type G is Rec
-- and therefore when reanalyzing "subtype W is G (D => 1);"
-- which really looks like "subtype W is Rec (D => 1);" at
-- the point of instantiation, we want to find the discriminant
-- that corresponds to D in Rec, ie X.
if Present (Original_Discriminant (Id)) then
Discr := Find_Corresponding_Discriminant (Id, T);
Found := True;
else
Discr := First_Discriminant (T);
while Present (Discr) loop
if Chars (Discr) = Chars (Id) then
Found := True;
exit;
end if;
Next_Discriminant (Discr);
end loop;
if not Found then
Error_Msg_N ("& does not match any discriminant", Id);
return New_Elmt_List;
-- The following is only useful for the benefit of generic
-- instances but it does not interfere with other
-- processing for the non-generic case so we do it in all
-- cases (for generics this statement is executed when
-- processing the generic definition, see comment at the
-- beginning of this if statement).
else
Set_Original_Discriminant (Id, Discr);
end if;
end if;
Position := Pos_Of_Discr (T, Discr);
if Present (Discr_Expr (Position)) then
Error_Msg_N ("duplicate constraint for discriminant&", Id);
else
-- Each discriminant specified in the same named association
-- must be associated with a separate copy of the
-- corresponding expression.
if Present (Next (Id)) then
Expr := New_Copy_Tree (Expression (Constr));
Set_Parent (Expr, Parent (Expression (Constr)));
else
Expr := Expression (Constr);
end if;
Discr_Expr (Position) := Expr;
Analyze_And_Resolve (Expr, Base_Type (Etype (Discr)));
end if;
-- A discriminant association with more than one discriminant
-- name is only allowed if the named discriminants are all of
-- the same type (RM 3.7.1(8)).
if E = Empty then
E := Base_Type (Etype (Discr));
elsif Base_Type (Etype (Discr)) /= E then
Error_Msg_N
("all discriminants in an association " &
"must have the same type", Id);
end if;
Next (Id);
end loop;
end if;
Next (Constr);
end loop;
-- A discriminant constraint must provide exactly one value for each
-- discriminant of the type (RM 3.7.1(8)).
for J in Discr_Expr'Range loop
if No (Discr_Expr (J)) then
Error_Msg_N ("too few discriminants given in constraint", C);
return New_Elmt_List;
end if;
end loop;
-- Determine if there are discriminant expressions in the constraint
for J in Discr_Expr'Range loop
if Denotes_Discriminant (Discr_Expr (J), Check_Protected => True) then
Discrim_Present := True;
end if;
end loop;
-- Build an element list consisting of the expressions given in the
-- discriminant constraint and apply the appropriate checks. The list
-- is constructed after resolving any named discriminant associations
-- and therefore the expressions appear in the textual order of the
-- discriminants.
Discr := First_Discriminant (T);
for J in Discr_Expr'Range loop
if Discr_Expr (J) /= Error then
Append_Elmt (Discr_Expr (J), Elist);
-- If any of the discriminant constraints is given by a
-- discriminant and we are in a derived type declaration we
-- have a discriminant renaming. Establish link between new
-- and old discriminant.
if Denotes_Discriminant (Discr_Expr (J)) then
if Derived_Def then
Set_Corresponding_Discriminant
(Entity (Discr_Expr (J)), Discr);
end if;
-- Force the evaluation of non-discriminant expressions.
-- If we have found a discriminant in the constraint 3.4(26)
-- and 3.8(18) demand that no range checks are performed are
-- after evaluation. If the constraint is for a component
-- definition that has a per-object constraint, expressions are
-- evaluated but not checked either. In all other cases perform
-- a range check.
else
if Discrim_Present then
null;
elsif Nkind (Parent (Parent (Def))) = N_Component_Declaration
and then
Has_Per_Object_Constraint
(Defining_Identifier (Parent (Parent (Def))))
then
null;
elsif Is_Access_Type (Etype (Discr)) then
Apply_Constraint_Check (Discr_Expr (J), Etype (Discr));
else
Apply_Range_Check (Discr_Expr (J), Etype (Discr));
end if;
Force_Evaluation (Discr_Expr (J));
end if;
-- Check that the designated type of an access discriminant's
-- expression is not a class-wide type unless the discriminant's
-- designated type is also class-wide.
if Ekind (Etype (Discr)) = E_Anonymous_Access_Type
and then not Is_Class_Wide_Type
(Designated_Type (Etype (Discr)))
and then Etype (Discr_Expr (J)) /= Any_Type
and then Is_Class_Wide_Type
(Designated_Type (Etype (Discr_Expr (J))))
then
Wrong_Type (Discr_Expr (J), Etype (Discr));
end if;
end if;
Next_Discriminant (Discr);
end loop;
return Elist;
end Build_Discriminant_Constraints;
---------------------------------
-- Build_Discriminated_Subtype --
---------------------------------
procedure Build_Discriminated_Subtype
(T : Entity_Id;
Def_Id : Entity_Id;
Elist : Elist_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False)
is
Has_Discrs : constant Boolean := Has_Discriminants (T);
Constrained : constant Boolean
:= (Has_Discrs
and then not Is_Empty_Elmt_List (Elist)
and then not Is_Class_Wide_Type (T))
or else Is_Constrained (T);
begin
if Ekind (T) = E_Record_Type then
if For_Access then
Set_Ekind (Def_Id, E_Private_Subtype);
Set_Is_For_Access_Subtype (Def_Id, True);
else
Set_Ekind (Def_Id, E_Record_Subtype);
end if;
elsif Ekind (T) = E_Task_Type then
Set_Ekind (Def_Id, E_Task_Subtype);
elsif Ekind (T) = E_Protected_Type then
Set_Ekind (Def_Id, E_Protected_Subtype);
elsif Is_Private_Type (T) then
Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
elsif Is_Class_Wide_Type (T) then
Set_Ekind (Def_Id, E_Class_Wide_Subtype);
else
-- Incomplete type. attach subtype to list of dependents, to be
-- completed with full view of parent type, unless is it the
-- designated subtype of a record component within an init_proc.
-- This last case arises for a component of an access type whose
-- designated type is incomplete (e.g. a Taft Amendment type).
-- The designated subtype is within an inner scope, and needs no
-- elaboration, because only the access type is needed in the
-- initialization procedure.
Set_Ekind (Def_Id, Ekind (T));
if For_Access and then Within_Init_Proc then
null;
else
Append_Elmt (Def_Id, Private_Dependents (T));
end if;
end if;
Set_Etype (Def_Id, T);
Init_Size_Align (Def_Id);
Set_Has_Discriminants (Def_Id, Has_Discrs);
Set_Is_Constrained (Def_Id, Constrained);
Set_First_Entity (Def_Id, First_Entity (T));
Set_Last_Entity (Def_Id, Last_Entity (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
if Is_Tagged_Type (T) then
Set_Is_Tagged_Type (Def_Id);
Make_Class_Wide_Type (Def_Id);
end if;
Set_Stored_Constraint (Def_Id, No_Elist);
if Has_Discrs then
Set_Discriminant_Constraint (Def_Id, Elist);
Set_Stored_Constraint_From_Discriminant_Constraint (Def_Id);
end if;
if Is_Tagged_Type (T) then
-- Ada 2005 (AI-251): In case of concurrent types we inherit the
-- concurrent record type (which has the list of primitive
-- operations).
if Ada_Version >= Ada_05
and then Is_Concurrent_Type (T)
then
Set_Corresponding_Record_Type (Def_Id,
Corresponding_Record_Type (T));
else
Set_Primitive_Operations (Def_Id, Primitive_Operations (T));
end if;
Set_Is_Abstract (Def_Id, Is_Abstract (T));
end if;
-- Subtypes introduced by component declarations do not need to be
-- marked as delayed, and do not get freeze nodes, because the semantics
-- verifies that the parents of the subtypes are frozen before the
-- enclosing record is frozen.
if not Is_Type (Scope (Def_Id)) then
Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
if Is_Private_Type (T)
and then Present (Full_View (T))
then
Conditional_Delay (Def_Id, Full_View (T));
else
Conditional_Delay (Def_Id, T);
end if;
end if;
if Is_Record_Type (T) then
Set_Is_Limited_Record (Def_Id, Is_Limited_Record (T));
if Has_Discrs
and then not Is_Empty_Elmt_List (Elist)
and then not For_Access
then
Create_Constrained_Components (Def_Id, Related_Nod, T, Elist);
elsif not For_Access then
Set_Cloned_Subtype (Def_Id, T);
end if;
end if;
end Build_Discriminated_Subtype;
------------------------
-- Build_Scalar_Bound --
------------------------
function Build_Scalar_Bound
(Bound : Node_Id;
Par_T : Entity_Id;
Der_T : Entity_Id) return Node_Id
is
New_Bound : Entity_Id;
begin
-- Note: not clear why this is needed, how can the original bound
-- be unanalyzed at this point? and if it is, what business do we
-- have messing around with it? and why is the base type of the
-- parent type the right type for the resolution. It probably is
-- not! It is OK for the new bound we are creating, but not for
-- the old one??? Still if it never happens, no problem!
Analyze_And_Resolve (Bound, Base_Type (Par_T));
if Nkind (Bound) = N_Integer_Literal
or else Nkind (Bound) = N_Real_Literal
then
New_Bound := New_Copy (Bound);
Set_Etype (New_Bound, Der_T);
Set_Analyzed (New_Bound);
elsif Is_Entity_Name (Bound) then
New_Bound := OK_Convert_To (Der_T, New_Copy (Bound));
-- The following is almost certainly wrong. What business do we have
-- relocating a node (Bound) that is presumably still attached to
-- the tree elsewhere???
else
New_Bound := OK_Convert_To (Der_T, Relocate_Node (Bound));
end if;
Set_Etype (New_Bound, Der_T);
return New_Bound;
end Build_Scalar_Bound;
--------------------------------
-- Build_Underlying_Full_View --
--------------------------------
procedure Build_Underlying_Full_View
(N : Node_Id;
Typ : Entity_Id;
Par : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Subt : constant Entity_Id :=
Make_Defining_Identifier
(Loc, New_External_Name (Chars (Typ), 'S'));
Constr : Node_Id;
Indic : Node_Id;
C : Node_Id;
Id : Node_Id;
procedure Set_Discriminant_Name (Id : Node_Id);
-- If the derived type has discriminants, they may rename discriminants
-- of the parent. When building the full view of the parent, we need to
-- recover the names of the original discriminants if the constraint is
-- given by named associations.
---------------------------
-- Set_Discriminant_Name --
---------------------------
procedure Set_Discriminant_Name (Id : Node_Id) is
Disc : Entity_Id;
begin
Set_Original_Discriminant (Id, Empty);
if Has_Discriminants (Typ) then
Disc := First_Discriminant (Typ);
while Present (Disc) loop
if Chars (Disc) = Chars (Id)
and then Present (Corresponding_Discriminant (Disc))
then
Set_Chars (Id, Chars (Corresponding_Discriminant (Disc)));
end if;
Next_Discriminant (Disc);
end loop;
end if;
end Set_Discriminant_Name;
-- Start of processing for Build_Underlying_Full_View
begin
if Nkind (N) = N_Full_Type_Declaration then
Constr := Constraint (Subtype_Indication (Type_Definition (N)));
elsif Nkind (N) = N_Subtype_Declaration then
Constr := New_Copy_Tree (Constraint (Subtype_Indication (N)));
elsif Nkind (N) = N_Component_Declaration then
Constr :=
New_Copy_Tree
(Constraint (Subtype_Indication (Component_Definition (N))));
else
raise Program_Error;
end if;
C := First (Constraints (Constr));
while Present (C) loop
if Nkind (C) = N_Discriminant_Association then
Id := First (Selector_Names (C));
while Present (Id) loop
Set_Discriminant_Name (Id);
Next (Id);
end loop;
end if;
Next (C);
end loop;
Indic :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Subt,
Subtype_Indication =>
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Reference_To (Par, Loc),
Constraint => New_Copy_Tree (Constr)));
-- If this is a component subtype for an outer itype, it is not
-- a list member, so simply set the parent link for analysis: if
-- the enclosing type does not need to be in a declarative list,
-- neither do the components.
if Is_List_Member (N)
and then Nkind (N) /= N_Component_Declaration
then
Insert_Before (N, Indic);
else
Set_Parent (Indic, Parent (N));
end if;
Analyze (Indic);
Set_Underlying_Full_View (Typ, Full_View (Subt));
end Build_Underlying_Full_View;
-------------------------------
-- Check_Abstract_Overriding --
-------------------------------
procedure Check_Abstract_Overriding (T : Entity_Id) is
Op_List : Elist_Id;
Elmt : Elmt_Id;
Subp : Entity_Id;
Alias_Subp : Entity_Id;
Type_Def : Node_Id;
begin
Op_List := Primitive_Operations (T);
-- Loop to check primitive operations
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
Alias_Subp := Alias (Subp);
-- Inherited subprograms are identified by the fact that they do not
-- come from source, and the associated source location is the
-- location of the first subtype of the derived type.
-- Special exception, do not complain about failure to override the
-- stream routines _Input and _Output, as well as the primitive
-- operations used in dispatching selects since we always provide
-- automatic overridings for these subprograms.
if (Is_Abstract (Subp)
or else (Has_Controlling_Result (Subp)
and then Present (Alias_Subp)
and then not Comes_From_Source (Subp)
and then Sloc (Subp) = Sloc (First_Subtype (T))))
and then not Is_TSS (Subp, TSS_Stream_Input)
and then not Is_TSS (Subp, TSS_Stream_Output)
and then not Is_Abstract (T)
and then Chars (Subp) /= Name_uDisp_Asynchronous_Select
and then Chars (Subp) /= Name_uDisp_Conditional_Select
and then Chars (Subp) /= Name_uDisp_Get_Prim_Op_Kind
and then Chars (Subp) /= Name_uDisp_Timed_Select
then
if Present (Alias_Subp) then
-- Only perform the check for a derived subprogram when the
-- type has an explicit record extension. This avoids
-- incorrectly flagging abstract subprograms for the case of a
-- type without an extension derived from a formal type with a
-- tagged actual (can occur within a private part).
-- Ada 2005 (AI-391): In the case of an inherited function with
-- a controlling result of the type, the rule does not apply if
-- the type is a null extension (unless the parent function
-- itself is abstract, in which case the function must still be
-- be overridden). The expander will generate an overriding
-- wrapper function calling the parent subprogram (see
-- Exp_Ch3.Make_Controlling_Wrapper_Functions).
Type_Def := Type_Definition (Parent (T));
if Nkind (Type_Def) = N_Derived_Type_Definition
and then Present (Record_Extension_Part (Type_Def))
and then
(Ada_Version < Ada_05
or else not Is_Null_Extension (T)
or else Ekind (Subp) = E_Procedure
or else not Has_Controlling_Result (Subp)
or else Is_Abstract (Alias_Subp)
or else Is_Access_Type (Etype (Subp)))
then
Error_Msg_NE
("type must be declared abstract or & overridden",
T, Subp);
-- Traverse the whole chain of aliased subprograms to
-- complete the error notification. This is especially
-- useful for traceability of the chain of entities when the
-- subprogram corresponds with an interface subprogram
-- (which might be defined in another package)
if Present (Alias_Subp) then
declare
E : Entity_Id;
begin
E := Subp;
while Present (Alias (E)) loop
Error_Msg_Sloc := Sloc (E);
Error_Msg_NE ("\& has been inherited #", T, Subp);
E := Alias (E);
end loop;
Error_Msg_Sloc := Sloc (E);
Error_Msg_NE
("\& has been inherited from subprogram #", T, Subp);
end;
end if;
-- Ada 2005 (AI-345): Protected or task type implementing
-- abstract interfaces.
elsif Is_Concurrent_Record_Type (T)
and then Present (Abstract_Interfaces (T))
then
Error_Msg_NE
("interface subprogram & must be overridden",
T, Subp);
end if;
else
Error_Msg_NE
("abstract subprogram not allowed for type&",
Subp, T);
Error_Msg_NE
("nonabstract type has abstract subprogram&",
T, Subp);
end if;
end if;
Next_Elmt (Elmt);
end loop;
end Check_Abstract_Overriding;
------------------------------------------------
-- Check_Access_Discriminant_Requires_Limited --
------------------------------------------------
procedure Check_Access_Discriminant_Requires_Limited
(D : Node_Id;
Loc : Node_Id)
is
begin
-- A discriminant_specification for an access discriminant shall appear
-- only in the declaration for a task or protected type, or for a type
-- with the reserved word 'limited' in its definition or in one of its
-- ancestors. (RM 3.7(10))
if Nkind (Discriminant_Type (D)) = N_Access_Definition
and then not Is_Concurrent_Type (Current_Scope)
and then not Is_Concurrent_Record_Type (Current_Scope)
and then not Is_Limited_Record (Current_Scope)
and then Ekind (Current_Scope) /= E_Limited_Private_Type
then
Error_Msg_N
("access discriminants allowed only for limited types", Loc);
end if;
end Check_Access_Discriminant_Requires_Limited;
-----------------------------------
-- Check_Aliased_Component_Types --
-----------------------------------
procedure Check_Aliased_Component_Types (T : Entity_Id) is
C : Entity_Id;
begin
-- ??? Also need to check components of record extensions, but not
-- components of protected types (which are always limited).
-- Ada 2005: AI-363 relaxes this rule, to allow heap objects of such
-- types to be unconstrained. This is safe because it is illegal to
-- create access subtypes to such types with explicit discriminant
-- constraints.
if not Is_Limited_Type (T) then
if Ekind (T) = E_Record_Type then
C := First_Component (T);
while Present (C) loop
if Is_Aliased (C)
and then Has_Discriminants (Etype (C))
and then not Is_Constrained (Etype (C))
and then not In_Instance_Body
and then Ada_Version < Ada_05
then
Error_Msg_N
("aliased component must be constrained ('R'M 3.6(11))",
C);
end if;
Next_Component (C);
end loop;
elsif Ekind (T) = E_Array_Type then
if Has_Aliased_Components (T)
and then Has_Discriminants (Component_Type (T))
and then not Is_Constrained (Component_Type (T))
and then not In_Instance_Body
and then Ada_Version < Ada_05
then
Error_Msg_N
("aliased component type must be constrained ('R'M 3.6(11))",
T);
end if;
end if;
end if;
end Check_Aliased_Component_Types;
----------------------
-- Check_Completion --
----------------------
procedure Check_Completion (Body_Id : Node_Id := Empty) is
E : Entity_Id;
procedure Post_Error;
-- Post error message for lack of completion for entity E
----------------
-- Post_Error --
----------------
procedure Post_Error is
begin
if not Comes_From_Source (E) then
if Ekind (E) = E_Task_Type
or else Ekind (E) = E_Protected_Type
then
-- It may be an anonymous protected type created for a
-- single variable. Post error on variable, if present.
declare
Var : Entity_Id;
begin
Var := First_Entity (Current_Scope);
while Present (Var) loop
exit when Etype (Var) = E
and then Comes_From_Source (Var);
Next_Entity (Var);
end loop;
if Present (Var) then
E := Var;
end if;
end;
end if;
end if;
-- If a generated entity has no completion, then either previous
-- semantic errors have disabled the expansion phase, or else we had
-- missing subunits, or else we are compiling without expan- sion,
-- or else something is very wrong.
if not Comes_From_Source (E) then
pragma Assert
(Serious_Errors_Detected > 0
or else Configurable_Run_Time_Violations > 0
or else Subunits_Missing
or else not Expander_Active);
return;
-- Here for source entity
else
-- Here if no body to post the error message, so we post the error
-- on the declaration that has no completion. This is not really
-- the right place to post it, think about this later ???
if No (Body_Id) then
if Is_Type (E) then
Error_Msg_NE
("missing full declaration for }", Parent (E), E);
else
Error_Msg_NE
("missing body for &", Parent (E), E);
end if;
-- Package body has no completion for a declaration that appears
-- in the corresponding spec. Post error on the body, with a
-- reference to the non-completed declaration.
else
Error_Msg_Sloc := Sloc (E);
if Is_Type (E) then
Error_Msg_NE
("missing full declaration for }!", Body_Id, E);
elsif Is_Overloadable (E)
and then Current_Entity_In_Scope (E) /= E
then
-- It may be that the completion is mistyped and appears
-- as a distinct overloading of the entity.
declare
Candidate : constant Entity_Id :=
Current_Entity_In_Scope (E);
Decl : constant Node_Id :=
Unit_Declaration_Node (Candidate);
begin
if Is_Overloadable (Candidate)
and then Ekind (Candidate) = Ekind (E)
and then Nkind (Decl) = N_Subprogram_Body
and then Acts_As_Spec (Decl)
then
Check_Type_Conformant (Candidate, E);
else
Error_Msg_NE ("missing body for & declared#!",
Body_Id, E);
end if;
end;
else
Error_Msg_NE ("missing body for & declared#!",
Body_Id, E);
end if;
end if;
end if;
end Post_Error;
-- Start processing for Check_Completion
begin
E := First_Entity (Current_Scope);
while Present (E) loop
if Is_Intrinsic_Subprogram (E) then
null;
-- The following situation requires special handling: a child
-- unit that appears in the context clause of the body of its
-- parent:
-- procedure Parent.Child (...);
-- with Parent.Child;
-- package body Parent is
-- Here Parent.Child appears as a local entity, but should not
-- be flagged as requiring completion, because it is a
-- compilation unit.
elsif Ekind (E) = E_Function
or else Ekind (E) = E_Procedure
or else Ekind (E) = E_Generic_Function
or else Ekind (E) = E_Generic_Procedure
then
if not Has_Completion (E)
and then not Is_Abstract (E)
and then Nkind (Parent (Unit_Declaration_Node (E))) /=
N_Compilation_Unit
and then Chars (E) /= Name_uSize
then
Post_Error;
end if;
elsif Is_Entry (E) then
if not Has_Completion (E) and then
(Ekind (Scope (E)) = E_Protected_Object
or else Ekind (Scope (E)) = E_Protected_Type)
then
Post_Error;
end if;
elsif Is_Package_Or_Generic_Package (E) then
if Unit_Requires_Body (E) then
if not Has_Completion (E)
and then Nkind (Parent (Unit_Declaration_Node (E))) /=
N_Compilation_Unit
then
Post_Error;
end if;
elsif not Is_Child_Unit (E) then
May_Need_Implicit_Body (E);
end if;
elsif Ekind (E) = E_Incomplete_Type
and then No (Underlying_Type (E))
then
Post_Error;
elsif (Ekind (E) = E_Task_Type or else
Ekind (E) = E_Protected_Type)
and then not Has_Completion (E)
then
Post_Error;
-- A single task declared in the current scope is a constant, verify
-- that the body of its anonymous type is in the same scope. If the
-- task is defined elsewhere, this may be a renaming declaration for
-- which no completion is needed.
elsif Ekind (E) = E_Constant
and then Ekind (Etype (E)) = E_Task_Type
and then not Has_Completion (Etype (E))
and then Scope (Etype (E)) = Current_Scope
then
Post_Error;
elsif Ekind (E) = E_Protected_Object
and then not Has_Completion (Etype (E))
then
Post_Error;
elsif Ekind (E) = E_Record_Type then
if Is_Tagged_Type (E) then
Check_Abstract_Overriding (E);
end if;
Check_Aliased_Component_Types (E);
elsif Ekind (E) = E_Array_Type then
Check_Aliased_Component_Types (E);
end if;
Next_Entity (E);
end loop;
end Check_Completion;
----------------------------
-- Check_Delta_Expression --
----------------------------
procedure Check_Delta_Expression (E : Node_Id) is
begin
if not (Is_Real_Type (Etype (E))) then
Wrong_Type (E, Any_Real);
elsif not Is_OK_Static_Expression (E) then
Flag_Non_Static_Expr
("non-static expression used for delta value!", E);
elsif not UR_Is_Positive (Expr_Value_R (E)) then
Error_Msg_N ("delta expression must be positive", E);
else
return;
end if;
-- If any of above errors occurred, then replace the incorrect
-- expression by the real 0.1, which should prevent further errors.
Rewrite (E,
Make_Real_Literal (Sloc (E), Ureal_Tenth));
Analyze_And_Resolve (E, Standard_Float);
end Check_Delta_Expression;
-----------------------------
-- Check_Digits_Expression --
-----------------------------
procedure Check_Digits_Expression (E : Node_Id) is
begin
if not (Is_Integer_Type (Etype (E))) then
Wrong_Type (E, Any_Integer);
elsif not Is_OK_Static_Expression (E) then
Flag_Non_Static_Expr
("non-static expression used for digits value!", E);
elsif Expr_Value (E) <= 0 then
Error_Msg_N ("digits value must be greater than zero", E);
else
return;
end if;
-- If any of above errors occurred, then replace the incorrect
-- expression by the integer 1, which should prevent further errors.
Rewrite (E, Make_Integer_Literal (Sloc (E), 1));
Analyze_And_Resolve (E, Standard_Integer);
end Check_Digits_Expression;
--------------------------
-- Check_Initialization --
--------------------------
procedure Check_Initialization (T : Entity_Id; Exp : Node_Id) is
begin
if (Is_Limited_Type (T)
or else Is_Limited_Composite (T))
and then not In_Instance
and then not In_Inlined_Body
then
-- Ada 2005 (AI-287): Relax the strictness of the front-end in
-- case of limited aggregates and extension aggregates.
if Ada_Version >= Ada_05
and then (Nkind (Exp) = N_Aggregate
or else Nkind (Exp) = N_Extension_Aggregate)
then
null;
else
Error_Msg_N
("cannot initialize entities of limited type", Exp);
Explain_Limited_Type (T, Exp);
end if;
end if;
end Check_Initialization;
------------------------------------
-- Check_Or_Process_Discriminants --
------------------------------------
-- If an incomplete or private type declaration was already given for the
-- type, the discriminants may have already been processed if they were
-- present on the incomplete declaration. In this case a full conformance
-- check is performed otherwise just process them.
procedure Check_Or_Process_Discriminants
(N : Node_Id;
T : Entity_Id;
Prev : Entity_Id := Empty)
is
begin
if Has_Discriminants (T) then
-- Make the discriminants visible to component declarations
declare
D : Entity_Id;
Prev : Entity_Id;
begin
D := First_Discriminant (T);
while Present (D) loop
Prev := Current_Entity (D);
Set_Current_Entity (D);
Set_Is_Immediately_Visible (D);
Set_Homonym (D, Prev);
-- Ada 2005 (AI-230): Access discriminant allowed in
-- non-limited record types.
if Ada_Version < Ada_05 then
-- This restriction gets applied to the full type here. It
-- has already been applied earlier to the partial view.
Check_Access_Discriminant_Requires_Limited (Parent (D), N);
end if;
Next_Discriminant (D);
end loop;
end;
elsif Present (Discriminant_Specifications (N)) then
Process_Discriminants (N, Prev);
end if;
end Check_Or_Process_Discriminants;
----------------------
-- Check_Real_Bound --
----------------------
procedure Check_Real_Bound (Bound : Node_Id) is
begin
if not Is_Real_Type (Etype (Bound)) then
Error_Msg_N
("bound in real type definition must be of real type", Bound);
elsif not Is_OK_Static_Expression (Bound) then
Flag_Non_Static_Expr
("non-static expression used for real type bound!", Bound);
else
return;
end if;
Rewrite
(Bound, Make_Real_Literal (Sloc (Bound), Ureal_0));
Analyze (Bound);
Resolve (Bound, Standard_Float);
end Check_Real_Bound;
------------------------
-- Collect_Interfaces --
------------------------
procedure Collect_Interfaces (N : Node_Id; Derived_Type : Entity_Id) is
Intf : Node_Id;
procedure Add_Interface (Iface : Entity_Id);
-- Add one interface
-------------------
-- Add_Interface --
-------------------
procedure Add_Interface (Iface : Entity_Id) is
Elmt : Elmt_Id;
begin
Elmt := First_Elmt (Abstract_Interfaces (Derived_Type));
while Present (Elmt) and then Node (Elmt) /= Iface loop
Next_Elmt (Elmt);
end loop;
if No (Elmt) then
Append_Elmt (Node => Iface,
To => Abstract_Interfaces (Derived_Type));
end if;
end Add_Interface;
-- Start of processing for Collect_Interfaces
begin
pragma Assert (False
or else Nkind (N) = N_Derived_Type_Definition
or else Nkind (N) = N_Record_Definition
or else Nkind (N) = N_Private_Extension_Declaration);
-- Traverse the graph of ancestor interfaces
if Is_Non_Empty_List (Interface_List (N)) then
Intf := First (Interface_List (N));
while Present (Intf) loop
-- Protect against wrong uses. For example:
-- type I is interface;
-- type O is tagged null record;
-- type Wrong is new I and O with null record; -- ERROR
if Is_Interface (Etype (Intf)) then
-- Do not add the interface when the derived type already
-- implements this interface
if not Interface_Present_In_Ancestor (Derived_Type,
Etype (Intf))
then
Collect_Interfaces
(Type_Definition (Parent (Etype (Intf))),
Derived_Type);
Add_Interface (Etype (Intf));
end if;
end if;
Next (Intf);
end loop;
end if;
end Collect_Interfaces;
------------------------------
-- Complete_Private_Subtype --
------------------------------
procedure Complete_Private_Subtype
(Priv : Entity_Id;
Full : Entity_Id;
Full_Base : Entity_Id;
Related_Nod : Node_Id)
is
Save_Next_Entity : Entity_Id;
Save_Homonym : Entity_Id;
begin
-- Set semantic attributes for (implicit) private subtype completion.
-- If the full type has no discriminants, then it is a copy of the full
-- view of the base. Otherwise, it is a subtype of the base with a
-- possible discriminant constraint. Save and restore the original
-- Next_Entity field of full to ensure that the calls to Copy_Node
-- do not corrupt the entity chain.
-- Note that the type of the full view is the same entity as the type of
-- the partial view. In this fashion, the subtype has access to the
-- correct view of the parent.
Save_Next_Entity := Next_Entity (Full);
Save_Homonym := Homonym (Priv);
case Ekind (Full_Base) is
when E_Record_Type |
E_Record_Subtype |
Class_Wide_Kind |
Private_Kind |
Task_Kind |
Protected_Kind =>
Copy_Node (Priv, Full);
Set_Has_Discriminants (Full, Has_Discriminants (Full_Base));
Set_First_Entity (Full, First_Entity (Full_Base));
Set_Last_Entity (Full, Last_Entity (Full_Base));
when others =>
Copy_Node (Full_Base, Full);
Set_Chars (Full, Chars (Priv));
Conditional_Delay (Full, Priv);
Set_Sloc (Full, Sloc (Priv));
end case;
Set_Next_Entity (Full, Save_Next_Entity);
Set_Homonym (Full, Save_Homonym);
Set_Associated_Node_For_Itype (Full, Related_Nod);
-- Set common attributes for all subtypes
Set_Ekind (Full, Subtype_Kind (Ekind (Full_Base)));
-- The Etype of the full view is inconsistent. Gigi needs to see the
-- structural full view, which is what the current scheme gives:
-- the Etype of the full view is the etype of the full base. However,
-- if the full base is a derived type, the full view then looks like
-- a subtype of the parent, not a subtype of the full base. If instead
-- we write:
-- Set_Etype (Full, Full_Base);
-- then we get inconsistencies in the front-end (confusion between
-- views). Several outstanding bugs are related to this ???
Set_Is_First_Subtype (Full, False);
Set_Scope (Full, Scope (Priv));
Set_Size_Info (Full, Full_Base);
Set_RM_Size (Full, RM_Size (Full_Base));
Set_Is_Itype (Full);
-- A subtype of a private-type-without-discriminants, whose full-view
-- has discriminants with default expressions, is not constrained!
if not Has_Discriminants (Priv) then
Set_Is_Constrained (Full, Is_Constrained (Full_Base));
if Has_Discriminants (Full_Base) then
Set_Discriminant_Constraint
(Full, Discriminant_Constraint (Full_Base));
-- The partial view may have been indefinite, the full view
-- might not be.
Set_Has_Unknown_Discriminants
(Full, Has_Unknown_Discriminants (Full_Base));
end if;
end if;
Set_First_Rep_Item (Full, First_Rep_Item (Full_Base));
Set_Depends_On_Private (Full, Has_Private_Component (Full));
-- Freeze the private subtype entity if its parent is delayed, and not
-- already frozen. We skip this processing if the type is an anonymous
-- subtype of a record component, or is the corresponding record of a
-- protected type, since ???
if not Is_Type (Scope (Full)) then
Set_Has_Delayed_Freeze (Full,
Has_Delayed_Freeze (Full_Base)
and then (not Is_Frozen (Full_Base)));
end if;
Set_Freeze_Node (Full, Empty);
Set_Is_Frozen (Full, False);
Set_Full_View (Priv, Full);
if Has_Discriminants (Full) then
Set_Stored_Constraint_From_Discriminant_Constraint (Full);
Set_Stored_Constraint (Priv, Stored_Constraint (Full));
if Has_Unknown_Discriminants (Full) then
Set_Discriminant_Constraint (Full, No_Elist);
end if;
end if;
if Ekind (Full_Base) = E_Record_Type
and then Has_Discriminants (Full_Base)
and then Has_Discriminants (Priv) -- might not, if errors
and then not Has_Unknown_Discriminants (Priv)
and then not Is_Empty_Elmt_List (Discriminant_Constraint (Priv))
then
Create_Constrained_Components
(Full, Related_Nod, Full_Base, Discriminant_Constraint (Priv));
-- If the full base is itself derived from private, build a congruent
-- subtype of its underlying type, for use by the back end. For a
-- constrained record component, the declaration cannot be placed on
-- the component list, but it must nevertheless be built an analyzed, to
-- supply enough information for Gigi to compute the size of component.
elsif Ekind (Full_Base) in Private_Kind
and then Is_Derived_Type (Full_Base)
and then Has_Discriminants (Full_Base)
and then (Ekind (Current_Scope) /= E_Record_Subtype)
then
if not Is_Itype (Priv)
and then
Nkind (Subtype_Indication (Parent (Priv))) = N_Subtype_Indication
then
Build_Underlying_Full_View
(Parent (Priv), Full, Etype (Full_Base));
elsif Nkind (Related_Nod) = N_Component_Declaration then
Build_Underlying_Full_View (Related_Nod, Full, Etype (Full_Base));
end if;
elsif Is_Record_Type (Full_Base) then
-- Show Full is simply a renaming of Full_Base
Set_Cloned_Subtype (Full, Full_Base);
end if;
-- It is unsafe to share to bounds of a scalar type, because the Itype
-- is elaborated on demand, and if a bound is non-static then different
-- orders of elaboration in different units will lead to different
-- external symbols.
if Is_Scalar_Type (Full_Base) then
Set_Scalar_Range (Full,
Make_Range (Sloc (Related_Nod),
Low_Bound =>
Duplicate_Subexpr_No_Checks (Type_Low_Bound (Full_Base)),
High_Bound =>
Duplicate_Subexpr_No_Checks (Type_High_Bound (Full_Base))));
-- This completion inherits the bounds of the full parent, but if
-- the parent is an unconstrained floating point type, so is the
-- completion.
if Is_Floating_Point_Type (Full_Base) then
Set_Includes_Infinities
(Scalar_Range (Full), Has_Infinities (Full_Base));
end if;
end if;
-- ??? It seems that a lot of fields are missing that should be copied
-- from Full_Base to Full. Here are some that are introduced in a
-- non-disruptive way but a cleanup is necessary.
if Is_Tagged_Type (Full_Base) then
Set_Is_Tagged_Type (Full);
Set_Primitive_Operations (Full, Primitive_Operations (Full_Base));
Set_Class_Wide_Type (Full, Class_Wide_Type (Full_Base));
-- If this is a subtype of a protected or task type, constrain its
-- corresponding record, unless this is a subtype without constraints,
-- i.e. a simple renaming as with an actual subtype in an instance.
elsif Is_Concurrent_Type (Full_Base) then
if Has_Discriminants (Full)
and then Present (Corresponding_Record_Type (Full_Base))
and then
not Is_Empty_Elmt_List (Discriminant_Constraint (Full))
then
Set_Corresponding_Record_Type (Full,
Constrain_Corresponding_Record
(Full, Corresponding_Record_Type (Full_Base),
Related_Nod, Full_Base));
else
Set_Corresponding_Record_Type (Full,
Corresponding_Record_Type (Full_Base));
end if;
end if;
end Complete_Private_Subtype;
-------------------------------------
-- Complete_Subprograms_Derivation --
-------------------------------------
procedure Complete_Subprograms_Derivation
(Partial_View : Entity_Id;
Derived_Type : Entity_Id)
is
Result : constant Elist_Id := New_Elmt_List;
Elmt_P : Elmt_Id;
Elmt_D : Elmt_Id;
Found : Boolean;
Prim_Op : Entity_Id;
E : Entity_Id;
begin
-- Handle the case in which the full-view is a transitive
-- derivation of the ancestor of the partial view.
-- type I is interface;
-- type T is new I with ...
-- package H is
-- type DT is new I with private;
-- private
-- type DT is new T with ...
-- end;
if Etype (Partial_View) /= Etype (Derived_Type)
and then Is_Interface (Etype (Partial_View))
and then Is_Ancestor (Etype (Partial_View), Etype (Derived_Type))
then
return;
end if;
if Is_Tagged_Type (Partial_View) then
Elmt_P := First_Elmt (Primitive_Operations (Partial_View));
else
Elmt_P := No_Elmt;
end if;
-- Inherit primitives declared with the partial-view
while Present (Elmt_P) loop
Prim_Op := Node (Elmt_P);
Found := False;
Elmt_D := First_Elmt (Primitive_Operations (Derived_Type));
while Present (Elmt_D) loop
if Node (Elmt_D) = Prim_Op then
Found := True;
exit;
end if;
Next_Elmt (Elmt_D);
end loop;
if not Found then
Append_Elmt (Prim_Op, Result);
-- Search for entries associated with abstract interfaces that
-- have been covered by this primitive
Elmt_D := First_Elmt (Primitive_Operations (Derived_Type));
while Present (Elmt_D) loop
E := Node (Elmt_D);
if Chars (E) = Chars (Prim_Op)
and then Is_Abstract (E)
and then Present (Alias (E))
and then Present (DTC_Entity (Alias (E)))
and then Is_Interface (Scope (DTC_Entity (Alias (E))))
then
Remove_Elmt (Primitive_Operations (Derived_Type), Elmt_D);
end if;
Next_Elmt (Elmt_D);
end loop;
end if;
Next_Elmt (Elmt_P);
end loop;
-- Append the entities of the full-view to the list of primitives
-- of derived_type.
Elmt_D := First_Elmt (Result);
while Present (Elmt_D) loop
Append_Elmt (Node (Elmt_D), Primitive_Operations (Derived_Type));
Next_Elmt (Elmt_D);
end loop;
end Complete_Subprograms_Derivation;
----------------------------
-- Constant_Redeclaration --
----------------------------
procedure Constant_Redeclaration
(Id : Entity_Id;
N : Node_Id;
T : out Entity_Id)
is
Prev : constant Entity_Id := Current_Entity_In_Scope (Id);
Obj_Def : constant Node_Id := Object_Definition (N);
New_T : Entity_Id;
procedure Check_Possible_Deferred_Completion
(Prev_Id : Entity_Id;
Prev_Obj_Def : Node_Id;
Curr_Obj_Def : Node_Id);
-- Determine whether the two object definitions describe the partial
-- and the full view of a constrained deferred constant. Generate
-- a subtype for the full view and verify that it statically matches
-- the subtype of the partial view.
procedure Check_Recursive_Declaration (Typ : Entity_Id);
-- If deferred constant is an access type initialized with an allocator,
-- check whether there is an illegal recursion in the definition,
-- through a default value of some record subcomponent. This is normally
-- detected when generating init procs, but requires this additional
-- mechanism when expansion is disabled.
----------------------------------------
-- Check_Possible_Deferred_Completion --
----------------------------------------
procedure Check_Possible_Deferred_Completion
(Prev_Id : Entity_Id;
Prev_Obj_Def : Node_Id;
Curr_Obj_Def : Node_Id)
is
begin
if Nkind (Prev_Obj_Def) = N_Subtype_Indication
and then Present (Constraint (Prev_Obj_Def))
and then Nkind (Curr_Obj_Def) = N_Subtype_Indication
and then Present (Constraint (Curr_Obj_Def))
then
declare
Loc : constant Source_Ptr := Sloc (N);
Def_Id : constant Entity_Id :=
Make_Defining_Identifier (Loc,
New_Internal_Name ('S'));
Decl : constant Node_Id :=
Make_Subtype_Declaration (Loc,
Defining_Identifier =>
Def_Id,
Subtype_Indication =>
Relocate_Node (Curr_Obj_Def));
begin
Insert_Before_And_Analyze (N, Decl);
Set_Etype (Id, Def_Id);
if not Subtypes_Statically_Match (Etype (Prev_Id), Def_Id) then
Error_Msg_Sloc := Sloc (Prev_Id);
Error_Msg_N ("subtype does not statically match deferred " &
"declaration#", N);
end if;
end;
end if;
end Check_Possible_Deferred_Completion;
---------------------------------
-- Check_Recursive_Declaration --
---------------------------------
procedure Check_Recursive_Declaration (Typ : Entity_Id) is
Comp : Entity_Id;
begin
if Is_Record_Type (Typ) then
Comp := First_Component (Typ);
while Present (Comp) loop
if Comes_From_Source (Comp) then
if Present (Expression (Parent (Comp)))
and then Is_Entity_Name (Expression (Parent (Comp)))
and then Entity (Expression (Parent (Comp))) = Prev
then
Error_Msg_Sloc := Sloc (Parent (Comp));
Error_Msg_NE
("illegal circularity with declaration for&#",
N, Comp);
return;
elsif Is_Record_Type (Etype (Comp)) then
Check_Recursive_Declaration (Etype (Comp));
end if;
end if;
Next_Component (Comp);
end loop;
end if;
end Check_Recursive_Declaration;
-- Start of processing for Constant_Redeclaration
begin
if Nkind (Parent (Prev)) = N_Object_Declaration then
if Nkind (Object_Definition
(Parent (Prev))) = N_Subtype_Indication
then
-- Find type of new declaration. The constraints of the two
-- views must match statically, but there is no point in
-- creating an itype for the full view.
if Nkind (Obj_Def) = N_Subtype_Indication then
Find_Type (Subtype_Mark (Obj_Def));
New_T := Entity (Subtype_Mark (Obj_Def));
else
Find_Type (Obj_Def);
New_T := Entity (Obj_Def);
end if;
T := Etype (Prev);
else
-- The full view may impose a constraint, even if the partial
-- view does not, so construct the subtype.
New_T := Find_Type_Of_Object (Obj_Def, N);
T := New_T;
end if;
else
-- Current declaration is illegal, diagnosed below in Enter_Name
T := Empty;
New_T := Any_Type;
end if;
-- If previous full declaration exists, or if a homograph is present,
-- let Enter_Name handle it, either with an error, or with the removal
-- of an overridden implicit subprogram.
if Ekind (Prev) /= E_Constant
or else Present (Expression (Parent (Prev)))
or else Present (Full_View (Prev))
then
Enter_Name (Id);
-- Verify that types of both declarations match, or else that both types
-- are anonymous access types whose designated subtypes statically match
-- (as allowed in Ada 2005 by AI-385).
elsif Base_Type (Etype (Prev)) /= Base_Type (New_T)
and then
(Ekind (Etype (Prev)) /= E_Anonymous_Access_Type
or else Ekind (Etype (New_T)) /= E_Anonymous_Access_Type
or else not Subtypes_Statically_Match
(Designated_Type (Etype (Prev)),
Designated_Type (Etype (New_T))))
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("type does not match declaration#", N);
Set_Full_View (Prev, Id);
Set_Etype (Id, Any_Type);
-- If so, process the full constant declaration
else
-- RM 7.4 (6): If the subtype defined by the subtype_indication in
-- the deferred declaration is constrained, then the subtype defined
-- by the subtype_indication in the full declaration shall match it
-- statically.
Check_Possible_Deferred_Completion
(Prev_Id => Prev,
Prev_Obj_Def => Object_Definition (Parent (Prev)),
Curr_Obj_Def => Obj_Def);
Set_Full_View (Prev, Id);
Set_Is_Public (Id, Is_Public (Prev));
Set_Is_Internal (Id);
Append_Entity (Id, Current_Scope);
-- Check ALIASED present if present before (RM 7.4(7))
if Is_Aliased (Prev)
and then not Aliased_Present (N)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("ALIASED required (see declaration#)", N);
end if;
-- Check that placement is in private part and that the incomplete
-- declaration appeared in the visible part.
if Ekind (Current_Scope) = E_Package
and then not In_Private_Part (Current_Scope)
then
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_N ("full constant for declaration#"
& " must be in private part", N);
elsif Ekind (Current_Scope) = E_Package
and then List_Containing (Parent (Prev))
/= Visible_Declarations
(Specification (Unit_Declaration_Node (Current_Scope)))
then
Error_Msg_N
("deferred constant must be declared in visible part",
Parent (Prev));
end if;
if Is_Access_Type (T)
and then Nkind (Expression (N)) = N_Allocator
then
Check_Recursive_Declaration (Designated_Type (T));
end if;
end if;
end Constant_Redeclaration;
----------------------
-- Constrain_Access --
----------------------
procedure Constrain_Access
(Def_Id : in out Entity_Id;
S : Node_Id;
Related_Nod : Node_Id)
is
T : constant Entity_Id := Entity (Subtype_Mark (S));
Desig_Type : constant Entity_Id := Designated_Type (T);
Desig_Subtype : Entity_Id := Create_Itype (E_Void, Related_Nod);
Constraint_OK : Boolean := True;
function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean;
-- Simple predicate to test for defaulted discriminants
-- Shouldn't this be in sem_util???
---------------------------------
-- Has_Defaulted_Discriminants --
---------------------------------
function Has_Defaulted_Discriminants (Typ : Entity_Id) return Boolean is
begin
return Has_Discriminants (Typ)
and then Present (First_Discriminant (Typ))
and then Present
(Discriminant_Default_Value (First_Discriminant (Typ)));
end Has_Defaulted_Discriminants;
-- Start of processing for Constrain_Access
begin
if Is_Array_Type (Desig_Type) then
Constrain_Array (Desig_Subtype, S, Related_Nod, Def_Id, 'P');
elsif (Is_Record_Type (Desig_Type)
or else Is_Incomplete_Or_Private_Type (Desig_Type))
and then not Is_Constrained (Desig_Type)
then
-- ??? The following code is a temporary kludge to ignore a
-- discriminant constraint on access type if it is constraining
-- the current record. Avoid creating the implicit subtype of the
-- record we are currently compiling since right now, we cannot
-- handle these. For now, just return the access type itself.
if Desig_Type = Current_Scope
and then No (Def_Id)
then
Set_Ekind (Desig_Subtype, E_Record_Subtype);
Def_Id := Entity (Subtype_Mark (S));
-- This call added to ensure that the constraint is analyzed
-- (needed for a B test). Note that we still return early from
-- this procedure to avoid recursive processing. ???
Constrain_Discriminated_Type
(Desig_Subtype, S, Related_Nod, For_Access => True);
return;
end if;
if Ekind (T) = E_General_Access_Type
and then Has_Private_Declaration (Desig_Type)
and then In_Open_Scopes (Scope (Desig_Type))
then
-- Enforce rule that the constraint is illegal if there is
-- an unconstrained view of the designated type. This means
-- that the partial view (either a private type declaration or
-- a derivation from a private type) has no discriminants.
-- (Defect Report 8652/0008, Technical Corrigendum 1, checked
-- by ACATS B371001).
-- Rule updated for Ada 2005: the private type is said to have
-- a constrained partial view, given that objects of the type
-- can be declared.
declare
Pack : constant Node_Id :=
Unit_Declaration_Node (Scope (Desig_Type));
Decls : List_Id;
Decl : Node_Id;
begin
if Nkind (Pack) = N_Package_Declaration then
Decls := Visible_Declarations (Specification (Pack));
Decl := First (Decls);
while Present (Decl) loop
if (Nkind (Decl) = N_Private_Type_Declaration
and then
Chars (Defining_Identifier (Decl)) =
Chars (Desig_Type))
or else
(Nkind (Decl) = N_Full_Type_Declaration
and then
Chars (Defining_Identifier (Decl)) =
Chars (Desig_Type)
and then Is_Derived_Type (Desig_Type)
and then
Has_Private_Declaration (Etype (Desig_Type)))
then
if No (Discriminant_Specifications (Decl)) then
Error_Msg_N
("cannot constrain general access type if " &
"designated type has constrained partial view",
S);
end if;
exit;
end if;
Next (Decl);
end loop;
end if;
end;
end if;
Constrain_Discriminated_Type (Desig_Subtype, S, Related_Nod,
For_Access => True);
elsif (Is_Task_Type (Desig_Type)
or else Is_Protected_Type (Desig_Type))
and then not Is_Constrained (Desig_Type)
then
Constrain_Concurrent
(Desig_Subtype, S, Related_Nod, Desig_Type, ' ');
else
Error_Msg_N ("invalid constraint on access type", S);
Desig_Subtype := Desig_Type; -- Ignore invalid constraint.
Constraint_OK := False;
end if;
if No (Def_Id) then
Def_Id := Create_Itype (E_Access_Subtype, Related_Nod);
else
Set_Ekind (Def_Id, E_Access_Subtype);
end if;
if Constraint_OK then
Set_Etype (Def_Id, Base_Type (T));
if Is_Private_Type (Desig_Type) then
Prepare_Private_Subtype_Completion (Desig_Subtype, Related_Nod);
end if;
else
Set_Etype (Def_Id, Any_Type);
end if;
Set_Size_Info (Def_Id, T);
Set_Is_Constrained (Def_Id, Constraint_OK);
Set_Directly_Designated_Type (Def_Id, Desig_Subtype);
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Is_Access_Constant (Def_Id, Is_Access_Constant (T));
Conditional_Delay (Def_Id, T);
-- AI-363 : Subtypes of general access types whose designated types have
-- default discriminants are disallowed. In instances, the rule has to
-- be checked against the actual, of which T is the subtype. In a
-- generic body, the rule is checked assuming that the actual type has
-- defaulted discriminants.
if Ada_Version >= Ada_05 then
if Ekind (Base_Type (T)) = E_General_Access_Type
and then Has_Defaulted_Discriminants (Desig_Type)
then
Error_Msg_N
("access subype of general access type not allowed", S);
Error_Msg_N ("\ when discriminants have defaults", S);
elsif Is_Access_Type (T)
and then Is_Generic_Type (Desig_Type)
and then Has_Discriminants (Desig_Type)
and then In_Package_Body (Current_Scope)
then
Error_Msg_N ("access subtype not allowed in generic body", S);
Error_Msg_N
("\ wben designated type is a discriminated formal", S);
end if;
end if;
end Constrain_Access;
---------------------
-- Constrain_Array --
---------------------
procedure Constrain_Array
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character)
is
C : constant Node_Id := Constraint (SI);
Number_Of_Constraints : Nat := 0;
Index : Node_Id;
S, T : Entity_Id;
Constraint_OK : Boolean := True;
begin
T := Entity (Subtype_Mark (SI));
if Ekind (T) in Access_Kind then
T := Designated_Type (T);
end if;
-- If an index constraint follows a subtype mark in a subtype indication
-- then the type or subtype denoted by the subtype mark must not already
-- impose an index constraint. The subtype mark must denote either an
-- unconstrained array type or an access type whose designated type
-- is such an array type... (RM 3.6.1)
if Is_Constrained (T) then
Error_Msg_N
("array type is already constrained", Subtype_Mark (SI));
Constraint_OK := False;
else
S := First (Constraints (C));
while Present (S) loop
Number_Of_Constraints := Number_Of_Constraints + 1;
Next (S);
end loop;
-- In either case, the index constraint must provide a discrete
-- range for each index of the array type and the type of each
-- discrete range must be the same as that of the corresponding
-- index. (RM 3.6.1)
if Number_Of_Constraints /= Number_Dimensions (T) then
Error_Msg_NE ("incorrect number of index constraints for }", C, T);
Constraint_OK := False;
else
S := First (Constraints (C));
Index := First_Index (T);
Analyze (Index);
-- Apply constraints to each index type
for J in 1 .. Number_Of_Constraints loop
Constrain_Index (Index, S, Related_Nod, Related_Id, Suffix, J);
Next (Index);
Next (S);
end loop;
end if;
end if;
if No (Def_Id) then
Def_Id :=
Create_Itype (E_Array_Subtype, Related_Nod, Related_Id, Suffix);
Set_Parent (Def_Id, Related_Nod);
else
Set_Ekind (Def_Id, E_Array_Subtype);
end if;
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Etype (Def_Id, Base_Type (T));
if Constraint_OK then
Set_First_Index (Def_Id, First (Constraints (C)));
else
Set_First_Index (Def_Id, First_Index (T));
end if;
Set_Is_Constrained (Def_Id, True);
Set_Is_Aliased (Def_Id, Is_Aliased (T));
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Is_Private_Composite (Def_Id, Is_Private_Composite (T));
Set_Is_Limited_Composite (Def_Id, Is_Limited_Composite (T));
-- Build a freeze node if parent still needs one. Also, make sure
-- that the Depends_On_Private status is set (explanation ???)
-- and also that a conditional delay is set.
Set_Depends_On_Private (Def_Id, Depends_On_Private (T));
Conditional_Delay (Def_Id, T);
end Constrain_Array;
------------------------------
-- Constrain_Component_Type --
------------------------------
function Constrain_Component_Type
(Comp : Entity_Id;
Constrained_Typ : Entity_Id;
Related_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id) return Entity_Id
is
Loc : constant Source_Ptr := Sloc (Constrained_Typ);
Compon_Type : constant Entity_Id := Etype (Comp);
function Build_Constrained_Array_Type
(Old_Type : Entity_Id) return Entity_Id;
-- If Old_Type is an array type, one of whose indices is constrained
-- by a discriminant, build an Itype whose constraint replaces the
-- discriminant with its value in the constraint.
function Build_Constrained_Discriminated_Type
(Old_Type : Entity_Id) return Entity_Id;
-- Ditto for record components
function Build_Constrained_Access_Type
(Old_Type : Entity_Id) return Entity_Id;
-- Ditto for access types. Makes use of previous two functions, to
-- constrain designated type.
function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id;
-- T is an array or discriminated type, C is a list of constraints
-- that apply to T. This routine builds the constrained subtype.
function Is_Discriminant (Expr : Node_Id) return Boolean;
-- Returns True if Expr is a discriminant
function Get_Discr_Value (Discrim : Entity_Id) return Node_Id;
-- Find the value of discriminant Discrim in Constraint
-----------------------------------
-- Build_Constrained_Access_Type --
-----------------------------------
function Build_Constrained_Access_Type
(Old_Type : Entity_Id) return Entity_Id
is
Desig_Type : constant Entity_Id := Designated_Type (Old_Type);
Itype : Entity_Id;
Desig_Subtype : Entity_Id;
Scop : Entity_Id;
begin
-- if the original access type was not embedded in the enclosing
-- type definition, there is no need to produce a new access
-- subtype. In fact every access type with an explicit constraint
-- generates an itype whose scope is the enclosing record.
if not Is_Type (Scope (Old_Type)) then
return Old_Type;
elsif Is_Array_Type (Desig_Type) then
Desig_Subtype := Build_Constrained_Array_Type (Desig_Type);
elsif Has_Discriminants (Desig_Type) then
-- This may be an access type to an enclosing record type for
-- which we are constructing the constrained components. Return
-- the enclosing record subtype. This is not always correct,
-- but avoids infinite recursion. ???
Desig_Subtype := Any_Type;
for J in reverse 0 .. Scope_Stack.Last loop
Scop := Scope_Stack.Table (J).Entity;
if Is_Type (Scop)
and then Base_Type (Scop) = Base_Type (Desig_Type)
then
Desig_Subtype := Scop;
end if;
exit when not Is_Type (Scop);
end loop;
if Desig_Subtype = Any_Type then
Desig_Subtype :=
Build_Constrained_Discriminated_Type (Desig_Type);
end if;
else
return Old_Type;
end if;
if Desig_Subtype /= Desig_Type then
-- The Related_Node better be here or else we won't be able
-- to attach new itypes to a node in the tree.
pragma Assert (Present (Related_Node));
Itype := Create_Itype (E_Access_Subtype, Related_Node);
Set_Etype (Itype, Base_Type (Old_Type));
Set_Size_Info (Itype, (Old_Type));
Set_Directly_Designated_Type (Itype, Desig_Subtype);
Set_Depends_On_Private (Itype, Has_Private_Component
(Old_Type));
Set_Is_Access_Constant (Itype, Is_Access_Constant
(Old_Type));
-- The new itype needs freezing when it depends on a not frozen
-- type and the enclosing subtype needs freezing.
if Has_Delayed_Freeze (Constrained_Typ)
and then not Is_Frozen (Constrained_Typ)
then
Conditional_Delay (Itype, Base_Type (Old_Type));
end if;
return Itype;
else
return Old_Type;
end if;
end Build_Constrained_Access_Type;
----------------------------------
-- Build_Constrained_Array_Type --
----------------------------------
function Build_Constrained_Array_Type
(Old_Type : Entity_Id) return Entity_Id
is
Lo_Expr : Node_Id;
Hi_Expr : Node_Id;
Old_Index : Node_Id;
Range_Node : Node_Id;
Constr_List : List_Id;
Need_To_Create_Itype : Boolean := False;
begin
Old_Index := First_Index (Old_Type);
while Present (Old_Index) loop
Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
if Is_Discriminant (Lo_Expr)
or else Is_Discriminant (Hi_Expr)
then
Need_To_Create_Itype := True;
end if;
Next_Index (Old_Index);
end loop;
if Need_To_Create_Itype then
Constr_List := New_List;
Old_Index := First_Index (Old_Type);
while Present (Old_Index) loop
Get_Index_Bounds (Old_Index, Lo_Expr, Hi_Expr);
if Is_Discriminant (Lo_Expr) then
Lo_Expr := Get_Discr_Value (Lo_Expr);
end if;
if Is_Discriminant (Hi_Expr) then
Hi_Expr := Get_Discr_Value (Hi_Expr);
end if;
Range_Node :=
Make_Range
(Loc, New_Copy_Tree (Lo_Expr), New_Copy_Tree (Hi_Expr));
Append (Range_Node, To => Constr_List);
Next_Index (Old_Index);
end loop;
return Build_Subtype (Old_Type, Constr_List);
else
return Old_Type;
end if;
end Build_Constrained_Array_Type;
------------------------------------------
-- Build_Constrained_Discriminated_Type --
------------------------------------------
function Build_Constrained_Discriminated_Type
(Old_Type : Entity_Id) return Entity_Id
is
Expr : Node_Id;
Constr_List : List_Id;
Old_Constraint : Elmt_Id;
Need_To_Create_Itype : Boolean := False;
begin
Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
while Present (Old_Constraint) loop
Expr := Node (Old_Constraint);
if Is_Discriminant (Expr) then
Need_To_Create_Itype := True;
end if;
Next_Elmt (Old_Constraint);
end loop;
if Need_To_Create_Itype then
Constr_List := New_List;
Old_Constraint := First_Elmt (Discriminant_Constraint (Old_Type));
while Present (Old_Constraint) loop
Expr := Node (Old_Constraint);
if Is_Discriminant (Expr) then
Expr := Get_Discr_Value (Expr);
end if;
Append (New_Copy_Tree (Expr), To => Constr_List);
Next_Elmt (Old_Constraint);
end loop;
return Build_Subtype (Old_Type, Constr_List);
else
return Old_Type;
end if;
end Build_Constrained_Discriminated_Type;
-------------------
-- Build_Subtype --
-------------------
function Build_Subtype (T : Entity_Id; C : List_Id) return Entity_Id is
Indic : Node_Id;
Subtyp_Decl : Node_Id;
Def_Id : Entity_Id;
Btyp : Entity_Id := Base_Type (T);
begin
-- The Related_Node better be here or else we won't be able to
-- attach new itypes to a node in the tree.
pragma Assert (Present (Related_Node));
-- If the view of the component's type is incomplete or private
-- with unknown discriminants, then the constraint must be applied
-- to the full type.
if Has_Unknown_Discriminants (Btyp)
and then Present (Underlying_Type (Btyp))
then
Btyp := Underlying_Type (Btyp);
end if;
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
Def_Id := Create_Itype (Ekind (T), Related_Node);
Subtyp_Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication => Indic);
Set_Parent (Subtyp_Decl, Parent (Related_Node));
-- Itypes must be analyzed with checks off (see package Itypes)
Analyze (Subtyp_Decl, Suppress => All_Checks);
return Def_Id;
end Build_Subtype;
---------------------
-- Get_Discr_Value --
---------------------
function Get_Discr_Value (Discrim : Entity_Id) return Node_Id is
D : Entity_Id;
E : Elmt_Id;
G : Elmt_Id;
begin
-- The discriminant may be declared for the type, in which case we
-- find it by iterating over the list of discriminants. If the
-- discriminant is inherited from a parent type, it appears as the
-- corresponding discriminant of the current type. This will be the
-- case when constraining an inherited component whose constraint is
-- given by a discriminant of the parent.
D := First_Discriminant (Typ);
E := First_Elmt (Constraints);
while Present (D) loop
if D = Entity (Discrim)
or else Corresponding_Discriminant (D) = Entity (Discrim)
then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
-- The corresponding_Discriminant mechanism is incomplete, because
-- the correspondence between new and old discriminants is not one
-- to one: one new discriminant can constrain several old ones. In
-- that case, scan sequentially the stored_constraint, the list of
-- discriminants of the parents, and the constraints.
if Is_Derived_Type (Typ)
and then Present (Stored_Constraint (Typ))
and then Scope (Entity (Discrim)) = Etype (Typ)
then
D := First_Discriminant (Etype (Typ));
E := First_Elmt (Constraints);
G := First_Elmt (Stored_Constraint (Typ));
while Present (D) loop
if D = Entity (Discrim) then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
Next_Elmt (G);
end loop;
end if;
-- Something is wrong if we did not find the value
raise Program_Error;
end Get_Discr_Value;
---------------------
-- Is_Discriminant --
---------------------
function Is_Discriminant (Expr : Node_Id) return Boolean is
Discrim_Scope : Entity_Id;
begin
if Denotes_Discriminant (Expr) then
Discrim_Scope := Scope (Entity (Expr));
-- Either we have a reference to one of Typ's discriminants,
pragma Assert (Discrim_Scope = Typ
-- or to the discriminants of the parent type, in the case
-- of a derivation of a tagged type with variants.
or else Discrim_Scope = Etype (Typ)
or else Full_View (Discrim_Scope) = Etype (Typ)
-- or same as above for the case where the discriminants
-- were declared in Typ's private view.
or else (Is_Private_Type (Discrim_Scope)
and then Chars (Discrim_Scope) = Chars (Typ))
-- or else we are deriving from the full view and the
-- discriminant is declared in the private entity.
or else (Is_Private_Type (Typ)
and then Chars (Discrim_Scope) = Chars (Typ))
-- or we have a class-wide type, in which case make sure the
-- discriminant found belongs to the root type.
or else (Is_Class_Wide_Type (Typ)
and then Etype (Typ) = Discrim_Scope));
return True;
end if;
-- In all other cases we have something wrong
return False;
end Is_Discriminant;
-- Start of processing for Constrain_Component_Type
begin
if Nkind (Parent (Comp)) = N_Component_Declaration
and then Comes_From_Source (Parent (Comp))
and then Comes_From_Source
(Subtype_Indication (Component_Definition (Parent (Comp))))
and then
Is_Entity_Name
(Subtype_Indication (Component_Definition (Parent (Comp))))
then
return Compon_Type;
elsif Is_Array_Type (Compon_Type) then
return Build_Constrained_Array_Type (Compon_Type);
elsif Has_Discriminants (Compon_Type) then
return Build_Constrained_Discriminated_Type (Compon_Type);
elsif Is_Access_Type (Compon_Type) then
return Build_Constrained_Access_Type (Compon_Type);
else
return Compon_Type;
end if;
end Constrain_Component_Type;
--------------------------
-- Constrain_Concurrent --
--------------------------
-- For concurrent types, the associated record value type carries the same
-- discriminants, so when we constrain a concurrent type, we must constrain
-- the corresponding record type as well.
procedure Constrain_Concurrent
(Def_Id : in out Entity_Id;
SI : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character)
is
T_Ent : Entity_Id := Entity (Subtype_Mark (SI));
T_Val : Entity_Id;
begin
if Ekind (T_Ent) in Access_Kind then
T_Ent := Designated_Type (T_Ent);
end if;
T_Val := Corresponding_Record_Type (T_Ent);
if Present (T_Val) then
if No (Def_Id) then
Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
Set_Depends_On_Private (Def_Id, Has_Private_Component (Def_Id));
Set_Corresponding_Record_Type (Def_Id,
Constrain_Corresponding_Record
(Def_Id, T_Val, Related_Nod, Related_Id));
else
-- If there is no associated record, expansion is disabled and this
-- is a generic context. Create a subtype in any case, so that
-- semantic analysis can proceed.
if No (Def_Id) then
Def_Id := Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
Constrain_Discriminated_Type (Def_Id, SI, Related_Nod);
end if;
end Constrain_Concurrent;
------------------------------------
-- Constrain_Corresponding_Record --
------------------------------------
function Constrain_Corresponding_Record
(Prot_Subt : Entity_Id;
Corr_Rec : Entity_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id) return Entity_Id
is
T_Sub : constant Entity_Id :=
Create_Itype (E_Record_Subtype, Related_Nod, Related_Id, 'V');
begin
Set_Etype (T_Sub, Corr_Rec);
Init_Size_Align (T_Sub);
Set_Has_Discriminants (T_Sub, Has_Discriminants (Prot_Subt));
Set_Is_Constrained (T_Sub, True);
Set_First_Entity (T_Sub, First_Entity (Corr_Rec));
Set_Last_Entity (T_Sub, Last_Entity (Corr_Rec));
Conditional_Delay (T_Sub, Corr_Rec);
if Has_Discriminants (Prot_Subt) then -- False only if errors.
Set_Discriminant_Constraint
(T_Sub, Discriminant_Constraint (Prot_Subt));
Set_Stored_Constraint_From_Discriminant_Constraint (T_Sub);
Create_Constrained_Components
(T_Sub, Related_Nod, Corr_Rec, Discriminant_Constraint (T_Sub));
end if;
Set_Depends_On_Private (T_Sub, Has_Private_Component (T_Sub));
return T_Sub;
end Constrain_Corresponding_Record;
-----------------------
-- Constrain_Decimal --
-----------------------
procedure Constrain_Decimal (Def_Id : Node_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
Loc : constant Source_Ptr := Sloc (C);
Range_Expr : Node_Id;
Digits_Expr : Node_Id;
Digits_Val : Uint;
Bound_Val : Ureal;
begin
Set_Ekind (Def_Id, E_Decimal_Fixed_Point_Subtype);
if Nkind (C) = N_Range_Constraint then
Range_Expr := Range_Expression (C);
Digits_Val := Digits_Value (T);
else
pragma Assert (Nkind (C) = N_Digits_Constraint);
Digits_Expr := Digits_Expression (C);
Analyze_And_Resolve (Digits_Expr, Any_Integer);
Check_Digits_Expression (Digits_Expr);
Digits_Val := Expr_Value (Digits_Expr);
if Digits_Val > Digits_Value (T) then
Error_Msg_N
("digits expression is incompatible with subtype", C);
Digits_Val := Digits_Value (T);
end if;
if Present (Range_Constraint (C)) then
Range_Expr := Range_Expression (Range_Constraint (C));
else
Range_Expr := Empty;
end if;
end if;
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Delta_Value (Def_Id, Delta_Value (T));
Set_Scale_Value (Def_Id, Scale_Value (T));
Set_Small_Value (Def_Id, Small_Value (T));
Set_Machine_Radix_10 (Def_Id, Machine_Radix_10 (T));
Set_Digits_Value (Def_Id, Digits_Val);
-- Manufacture range from given digits value if no range present
if No (Range_Expr) then
Bound_Val := (Ureal_10 ** Digits_Val - Ureal_1) * Small_Value (T);
Range_Expr :=
Make_Range (Loc,
Low_Bound =>
Convert_To (T, Make_Real_Literal (Loc, (-Bound_Val))),
High_Bound =>
Convert_To (T, Make_Real_Literal (Loc, Bound_Val)));
end if;
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expr, T);
Set_Discrete_RM_Size (Def_Id);
-- Unconditionally delay the freeze, since we cannot set size
-- information in all cases correctly until the freeze point.
Set_Has_Delayed_Freeze (Def_Id);
end Constrain_Decimal;
----------------------------------
-- Constrain_Discriminated_Type --
----------------------------------
procedure Constrain_Discriminated_Type
(Def_Id : Entity_Id;
S : Node_Id;
Related_Nod : Node_Id;
For_Access : Boolean := False)
is
E : constant Entity_Id := Entity (Subtype_Mark (S));
T : Entity_Id;
C : Node_Id;
Elist : Elist_Id := New_Elmt_List;
procedure Fixup_Bad_Constraint;
-- This is called after finding a bad constraint, and after having
-- posted an appropriate error message. The mission is to leave the
-- entity T in as reasonable state as possible!
--------------------------
-- Fixup_Bad_Constraint --
--------------------------
procedure Fixup_Bad_Constraint is
begin
-- Set a reasonable Ekind for the entity. For an incomplete type,
-- we can't do much, but for other types, we can set the proper
-- corresponding subtype kind.
if Ekind (T) = E_Incomplete_Type then
Set_Ekind (Def_Id, Ekind (T));
else
Set_Ekind (Def_Id, Subtype_Kind (Ekind (T)));
end if;
Set_Etype (Def_Id, Any_Type);
Set_Error_Posted (Def_Id);
end Fixup_Bad_Constraint;
-- Start of processing for Constrain_Discriminated_Type
begin
C := Constraint (S);
-- A discriminant constraint is only allowed in a subtype indication,
-- after a subtype mark. This subtype mark must denote either a type
-- with discriminants, or an access type whose designated type is a
-- type with discriminants. A discriminant constraint specifies the
-- values of these discriminants (RM 3.7.2(5)).
T := Base_Type (Entity (Subtype_Mark (S)));
if Ekind (T) in Access_Kind then
T := Designated_Type (T);
end if;
-- Check that the type has visible discriminants. The type may be
-- a private type with unknown discriminants whose full view has
-- discriminants which are invisible.
if not Has_Discriminants (T)
or else
(Has_Unknown_Discriminants (T)
and then Is_Private_Type (T))
then
Error_Msg_N ("invalid constraint: type has no discriminant", C);
Fixup_Bad_Constraint;
return;
elsif Is_Constrained (E)
or else (Ekind (E) = E_Class_Wide_Subtype
and then Present (Discriminant_Constraint (E)))
then
Error_Msg_N ("type is already constrained", Subtype_Mark (S));
Fixup_Bad_Constraint;
return;
end if;
-- T may be an unconstrained subtype (e.g. a generic actual).
-- Constraint applies to the base type.
T := Base_Type (T);
Elist := Build_Discriminant_Constraints (T, S);
-- If the list returned was empty we had an error in building the
-- discriminant constraint. We have also already signalled an error
-- in the incomplete type case
if Is_Empty_Elmt_List (Elist) then
Fixup_Bad_Constraint;
return;
end if;
Build_Discriminated_Subtype (T, Def_Id, Elist, Related_Nod, For_Access);
end Constrain_Discriminated_Type;
---------------------------
-- Constrain_Enumeration --
---------------------------
procedure Constrain_Enumeration (Def_Id : Node_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
begin
Set_Ekind (Def_Id, E_Enumeration_Subtype);
Set_First_Literal (Def_Id, First_Literal (Base_Type (T)));
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
Set_Discrete_RM_Size (Def_Id);
end Constrain_Enumeration;
----------------------
-- Constrain_Float --
----------------------
procedure Constrain_Float (Def_Id : Node_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : Node_Id;
D : Node_Id;
Rais : Node_Id;
begin
Set_Ekind (Def_Id, E_Floating_Point_Subtype);
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
-- Process the constraint
C := Constraint (S);
-- Digits constraint present
if Nkind (C) = N_Digits_Constraint then
Check_Restriction (No_Obsolescent_Features, C);
if Warn_On_Obsolescent_Feature then
Error_Msg_N
("subtype digits constraint is an " &
"obsolescent feature ('R'M 'J.3(8))?", C);
end if;
D := Digits_Expression (C);
Analyze_And_Resolve (D, Any_Integer);
Check_Digits_Expression (D);
Set_Digits_Value (Def_Id, Expr_Value (D));
-- Check that digits value is in range. Obviously we can do this
-- at compile time, but it is strictly a runtime check, and of
-- course there is an ACVC test that checks this!
if Digits_Value (Def_Id) > Digits_Value (T) then
Error_Msg_Uint_1 := Digits_Value (T);
Error_Msg_N ("?digits value is too large, maximum is ^", D);
Rais :=
Make_Raise_Constraint_Error (Sloc (D),
Reason => CE_Range_Check_Failed);
Insert_Action (Declaration_Node (Def_Id), Rais);
end if;
C := Range_Constraint (C);
-- No digits constraint present
else
Set_Digits_Value (Def_Id, Digits_Value (T));
end if;
-- Range constraint present
if Nkind (C) = N_Range_Constraint then
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
-- No range constraint present
else
pragma Assert (No (C));
Set_Scalar_Range (Def_Id, Scalar_Range (T));
end if;
Set_Is_Constrained (Def_Id);
end Constrain_Float;
---------------------
-- Constrain_Index --
---------------------
procedure Constrain_Index
(Index : Node_Id;
S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id;
Suffix : Character;
Suffix_Index : Nat)
is
Def_Id : Entity_Id;
R : Node_Id := Empty;
T : constant Entity_Id := Etype (Index);
begin
if Nkind (S) = N_Range
or else
(Nkind (S) = N_Attribute_Reference
and then Attribute_Name (S) = Name_Range)
then
-- A Range attribute will transformed into N_Range by Resolve
Analyze (S);
Set_Etype (S, T);
R := S;
Process_Range_Expr_In_Decl (R, T, Empty_List);
if not Error_Posted (S)
and then
(Nkind (S) /= N_Range
or else not Covers (T, (Etype (Low_Bound (S))))
or else not Covers (T, (Etype (High_Bound (S)))))
then
if Base_Type (T) /= Any_Type
and then Etype (Low_Bound (S)) /= Any_Type
and then Etype (High_Bound (S)) /= Any_Type
then
Error_Msg_N ("range expected", S);
end if;
end if;
elsif Nkind (S) = N_Subtype_Indication then
-- The parser has verified that this is a discrete indication
Resolve_Discrete_Subtype_Indication (S, T);
R := Range_Expression (Constraint (S));
elsif Nkind (S) = N_Discriminant_Association then
-- Syntactically valid in subtype indication
Error_Msg_N ("invalid index constraint", S);
Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
return;
-- Subtype_Mark case, no anonymous subtypes to construct
else
Analyze (S);
if Is_Entity_Name (S) then
if not Is_Type (Entity (S)) then
Error_Msg_N ("expect subtype mark for index constraint", S);
elsif Base_Type (Entity (S)) /= Base_Type (T) then
Wrong_Type (S, Base_Type (T));
end if;
return;
else
Error_Msg_N ("invalid index constraint", S);
Rewrite (S, New_Occurrence_Of (T, Sloc (S)));
return;
end if;
end if;
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix, Suffix_Index);
Set_Etype (Def_Id, Base_Type (T));
if Is_Modular_Integer_Type (T) then
Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
elsif Is_Integer_Type (T) then
Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
else
Set_Ekind (Def_Id, E_Enumeration_Subtype);
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
end if;
Set_Size_Info (Def_Id, (T));
Set_RM_Size (Def_Id, RM_Size (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Scalar_Range (Def_Id, R);
Set_Etype (S, Def_Id);
Set_Discrete_RM_Size (Def_Id);
end Constrain_Index;
-----------------------
-- Constrain_Integer --
-----------------------
procedure Constrain_Integer (Def_Id : Node_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : constant Node_Id := Constraint (S);
begin
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
if Is_Modular_Integer_Type (T) then
Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
else
Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
end if;
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Discrete_RM_Size (Def_Id);
end Constrain_Integer;
------------------------------
-- Constrain_Ordinary_Fixed --
------------------------------
procedure Constrain_Ordinary_Fixed (Def_Id : Node_Id; S : Node_Id) is
T : constant Entity_Id := Entity (Subtype_Mark (S));
C : Node_Id;
D : Node_Id;
Rais : Node_Id;
begin
Set_Ekind (Def_Id, E_Ordinary_Fixed_Point_Subtype);
Set_Etype (Def_Id, Base_Type (T));
Set_Size_Info (Def_Id, (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Small_Value (Def_Id, Small_Value (T));
-- Process the constraint
C := Constraint (S);
-- Delta constraint present
if Nkind (C) = N_Delta_Constraint then
Check_Restriction (No_Obsolescent_Features, C);
if Warn_On_Obsolescent_Feature then
Error_Msg_S
("subtype delta constraint is an " &
"obsolescent feature ('R'M 'J.3(7))?");
end if;
D := Delta_Expression (C);
Analyze_And_Resolve (D, Any_Real);
Check_Delta_Expression (D);
Set_Delta_Value (Def_Id, Expr_Value_R (D));
-- Check that delta value is in range. Obviously we can do this
-- at compile time, but it is strictly a runtime check, and of
-- course there is an ACVC test that checks this!
if Delta_Value (Def_Id) < Delta_Value (T) then
Error_Msg_N ("?delta value is too small", D);
Rais :=
Make_Raise_Constraint_Error (Sloc (D),
Reason => CE_Range_Check_Failed);
Insert_Action (Declaration_Node (Def_Id), Rais);
end if;
C := Range_Constraint (C);
-- No delta constraint present
else
Set_Delta_Value (Def_Id, Delta_Value (T));
end if;
-- Range constraint present
if Nkind (C) = N_Range_Constraint then
Set_Scalar_Range_For_Subtype (Def_Id, Range_Expression (C), T);
-- No range constraint present
else
pragma Assert (No (C));
Set_Scalar_Range (Def_Id, Scalar_Range (T));
end if;
Set_Discrete_RM_Size (Def_Id);
-- Unconditionally delay the freeze, since we cannot set size
-- information in all cases correctly until the freeze point.
Set_Has_Delayed_Freeze (Def_Id);
end Constrain_Ordinary_Fixed;
---------------------------
-- Convert_Scalar_Bounds --
---------------------------
procedure Convert_Scalar_Bounds
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Loc : Source_Ptr)
is
Implicit_Base : constant Entity_Id := Base_Type (Derived_Type);
Lo : Node_Id;
Hi : Node_Id;
Rng : Node_Id;
begin
Lo := Build_Scalar_Bound
(Type_Low_Bound (Derived_Type),
Parent_Type, Implicit_Base);
Hi := Build_Scalar_Bound
(Type_High_Bound (Derived_Type),
Parent_Type, Implicit_Base);
Rng :=
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi);
Set_Includes_Infinities (Rng, Has_Infinities (Derived_Type));
Set_Parent (Rng, N);
Set_Scalar_Range (Derived_Type, Rng);
-- Analyze the bounds
Analyze_And_Resolve (Lo, Implicit_Base);
Analyze_And_Resolve (Hi, Implicit_Base);
-- Analyze the range itself, except that we do not analyze it if
-- the bounds are real literals, and we have a fixed-point type.
-- The reason for this is that we delay setting the bounds in this
-- case till we know the final Small and Size values (see circuit
-- in Freeze.Freeze_Fixed_Point_Type for further details).
if Is_Fixed_Point_Type (Parent_Type)
and then Nkind (Lo) = N_Real_Literal
and then Nkind (Hi) = N_Real_Literal
then
return;
-- Here we do the analysis of the range
-- Note: we do this manually, since if we do a normal Analyze and
-- Resolve call, there are problems with the conversions used for
-- the derived type range.
else
Set_Etype (Rng, Implicit_Base);
Set_Analyzed (Rng, True);
end if;
end Convert_Scalar_Bounds;
-------------------
-- Copy_And_Swap --
-------------------
procedure Copy_And_Swap (Priv, Full : Entity_Id) is
begin
-- Initialize new full declaration entity by copying the pertinent
-- fields of the corresponding private declaration entity.
-- We temporarily set Ekind to a value appropriate for a type to
-- avoid assert failures in Einfo from checking for setting type
-- attributes on something that is not a type. Ekind (Priv) is an
-- appropriate choice, since it allowed the attributes to be set
-- in the first place. This Ekind value will be modified later.
Set_Ekind (Full, Ekind (Priv));
-- Also set Etype temporarily to Any_Type, again, in the absence
-- of errors, it will be properly reset, and if there are errors,
-- then we want a value of Any_Type to remain.
Set_Etype (Full, Any_Type);
-- Now start copying attributes
Set_Has_Discriminants (Full, Has_Discriminants (Priv));
if Has_Discriminants (Full) then
Set_Discriminant_Constraint (Full, Discriminant_Constraint (Priv));
Set_Stored_Constraint (Full, Stored_Constraint (Priv));
end if;
Set_First_Rep_Item (Full, First_Rep_Item (Priv));
Set_Homonym (Full, Homonym (Priv));
Set_Is_Immediately_Visible (Full, Is_Immediately_Visible (Priv));
Set_Is_Public (Full, Is_Public (Priv));
Set_Is_Pure (Full, Is_Pure (Priv));
Set_Is_Tagged_Type (Full, Is_Tagged_Type (Priv));
Conditional_Delay (Full, Priv);
if Is_Tagged_Type (Full) then
Set_Primitive_Operations (Full, Primitive_Operations (Priv));
if Priv = Base_Type (Priv) then
Set_Class_Wide_Type (Full, Class_Wide_Type (Priv));
end if;
end if;
Set_Is_Volatile (Full, Is_Volatile (Priv));
Set_Treat_As_Volatile (Full, Treat_As_Volatile (Priv));
Set_Scope (Full, Scope (Priv));
Set_Next_Entity (Full, Next_Entity (Priv));
Set_First_Entity (Full, First_Entity (Priv));
Set_Last_Entity (Full, Last_Entity (Priv));
-- If access types have been recorded for later handling, keep them in
-- the full view so that they get handled when the full view freeze
-- node is expanded.
if Present (Freeze_Node (Priv))
and then Present (Access_Types_To_Process (Freeze_Node (Priv)))
then
Ensure_Freeze_Node (Full);
Set_Access_Types_To_Process
(Freeze_Node (Full),
Access_Types_To_Process (Freeze_Node (Priv)));
end if;
-- Swap the two entities. Now Privat is the full type entity and
-- Full is the private one. They will be swapped back at the end
-- of the private part. This swapping ensures that the entity that
-- is visible in the private part is the full declaration.
Exchange_Entities (Priv, Full);
Append_Entity (Full, Scope (Full));
end Copy_And_Swap;
-------------------------------------
-- Copy_Array_Base_Type_Attributes --
-------------------------------------
procedure Copy_Array_Base_Type_Attributes (T1, T2 : Entity_Id) is
begin
Set_Component_Alignment (T1, Component_Alignment (T2));
Set_Component_Type (T1, Component_Type (T2));
Set_Component_Size (T1, Component_Size (T2));
Set_Has_Controlled_Component (T1, Has_Controlled_Component (T2));
Set_Finalize_Storage_Only (T1, Finalize_Storage_Only (T2));
Set_Has_Non_Standard_Rep (T1, Has_Non_Standard_Rep (T2));
Set_Has_Task (T1, Has_Task (T2));
Set_Is_Packed (T1, Is_Packed (T2));
Set_Has_Aliased_Components (T1, Has_Aliased_Components (T2));
Set_Has_Atomic_Components (T1, Has_Atomic_Components (T2));
Set_Has_Volatile_Components (T1, Has_Volatile_Components (T2));
end Copy_Array_Base_Type_Attributes;
-----------------------------------
-- Copy_Array_Subtype_Attributes --
-----------------------------------
procedure Copy_Array_Subtype_Attributes (T1, T2 : Entity_Id) is
begin
Set_Size_Info (T1, T2);
Set_First_Index (T1, First_Index (T2));
Set_Is_Aliased (T1, Is_Aliased (T2));
Set_Is_Atomic (T1, Is_Atomic (T2));
Set_Is_Volatile (T1, Is_Volatile (T2));
Set_Treat_As_Volatile (T1, Treat_As_Volatile (T2));
Set_Is_Constrained (T1, Is_Constrained (T2));
Set_Depends_On_Private (T1, Has_Private_Component (T2));
Set_First_Rep_Item (T1, First_Rep_Item (T2));
Set_Convention (T1, Convention (T2));
Set_Is_Limited_Composite (T1, Is_Limited_Composite (T2));
Set_Is_Private_Composite (T1, Is_Private_Composite (T2));
end Copy_Array_Subtype_Attributes;
-----------------------------------
-- Create_Constrained_Components --
-----------------------------------
procedure Create_Constrained_Components
(Subt : Entity_Id;
Decl_Node : Node_Id;
Typ : Entity_Id;
Constraints : Elist_Id)
is
Loc : constant Source_Ptr := Sloc (Subt);
Comp_List : constant Elist_Id := New_Elmt_List;
Parent_Type : constant Entity_Id := Etype (Typ);
Assoc_List : constant List_Id := New_List;
Discr_Val : Elmt_Id;
Errors : Boolean;
New_C : Entity_Id;
Old_C : Entity_Id;
Is_Static : Boolean := True;
procedure Collect_Fixed_Components (Typ : Entity_Id);
-- Collect parent type components that do not appear in a variant part
procedure Create_All_Components;
-- Iterate over Comp_List to create the components of the subtype
function Create_Component (Old_Compon : Entity_Id) return Entity_Id;
-- Creates a new component from Old_Compon, copying all the fields from
-- it, including its Etype, inserts the new component in the Subt entity
-- chain and returns the new component.
function Is_Variant_Record (T : Entity_Id) return Boolean;
-- If true, and discriminants are static, collect only components from
-- variants selected by discriminant values.
------------------------------
-- Collect_Fixed_Components --
------------------------------
procedure Collect_Fixed_Components (Typ : Entity_Id) is
begin
-- Build association list for discriminants, and find components of the
-- variant part selected by the values of the discriminants.
Old_C := First_Discriminant (Typ);
Discr_Val := First_Elmt (Constraints);
while Present (Old_C) loop
Append_To (Assoc_List,
Make_Component_Association (Loc,
Choices => New_List (New_Occurrence_Of (Old_C, Loc)),
Expression => New_Copy (Node (Discr_Val))));
Next_Elmt (Discr_Val);
Next_Discriminant (Old_C);
end loop;
-- The tag, and the possible parent and controller components
-- are unconditionally in the subtype.
if Is_Tagged_Type (Typ)
or else Has_Controlled_Component (Typ)
then
Old_C := First_Component (Typ);
while Present (Old_C) loop
if Chars ((Old_C)) = Name_uTag
or else Chars ((Old_C)) = Name_uParent
or else Chars ((Old_C)) = Name_uController
then
Append_Elmt (Old_C, Comp_List);
end if;
Next_Component (Old_C);
end loop;
end if;
end Collect_Fixed_Components;
---------------------------
-- Create_All_Components --
---------------------------
procedure Create_All_Components is
Comp : Elmt_Id;
begin
Comp := First_Elmt (Comp_List);
while Present (Comp) loop
Old_C := Node (Comp);
New_C := Create_Component (Old_C);
Set_Etype
(New_C,
Constrain_Component_Type
(Old_C, Subt, Decl_Node, Typ, Constraints));
Set_Is_Public (New_C, Is_Public (Subt));
Next_Elmt (Comp);
end loop;
end Create_All_Components;
----------------------
-- Create_Component --
----------------------
function Create_Component (Old_Compon : Entity_Id) return Entity_Id is
New_Compon : constant Entity_Id := New_Copy (Old_Compon);
begin
if Ekind (Old_Compon) = E_Discriminant
and then Is_Completely_Hidden (Old_Compon)
then
-- This is a shadow discriminant created for a discriminant of
-- the parent type that is one of several renamed by the same
-- new discriminant. Give the shadow discriminant an internal
-- name that cannot conflict with that of visible components.
Set_Chars (New_Compon, New_Internal_Name ('C'));
end if;
-- Set the parent so we have a proper link for freezing etc. This is
-- not a real parent pointer, since of course our parent does not own
-- up to us and reference us, we are an illegitimate child of the
-- original parent!
Set_Parent (New_Compon, Parent (Old_Compon));
-- If the old component's Esize was already determined and is a
-- static value, then the new component simply inherits it. Otherwise
-- the old component's size may require run-time determination, but
-- the new component's size still might be statically determinable
-- (if, for example it has a static constraint). In that case we want
-- Layout_Type to recompute the component's size, so we reset its
-- size and positional fields.
if Frontend_Layout_On_Target
and then not Known_Static_Esize (Old_Compon)
then
Set_Esize (New_Compon, Uint_0);
Init_Normalized_First_Bit (New_Compon);
Init_Normalized_Position (New_Compon);
Init_Normalized_Position_Max (New_Compon);
end if;
-- We do not want this node marked as Comes_From_Source, since
-- otherwise it would get first class status and a separate cross-
-- reference line would be generated. Illegitimate children do not
-- rate such recognition.
Set_Comes_From_Source (New_Compon, False);
-- But it is a real entity, and a birth certificate must be properly
-- registered by entering it into the entity list.
Enter_Name (New_Compon);
return New_Compon;
end Create_Component;
-----------------------
-- Is_Variant_Record --
-----------------------
function Is_Variant_Record (T : Entity_Id) return Boolean is
begin
return Nkind (Parent (T)) = N_Full_Type_Declaration
and then Nkind (Type_Definition (Parent (T))) = N_Record_Definition
and then Present (Component_List (Type_Definition (Parent (T))))
and then Present (
Variant_Part (Component_List (Type_Definition (Parent (T)))));
end Is_Variant_Record;
-- Start of processing for Create_Constrained_Components
begin
pragma Assert (Subt /= Base_Type (Subt));
pragma Assert (Typ = Base_Type (Typ));
Set_First_Entity (Subt, Empty);
Set_Last_Entity (Subt, Empty);
-- Check whether constraint is fully static, in which case we can
-- optimize the list of components.
Discr_Val := First_Elmt (Constraints);
while Present (Discr_Val) loop
if not Is_OK_Static_Expression (Node (Discr_Val)) then
Is_Static := False;
exit;
end if;
Next_Elmt (Discr_Val);
end loop;
New_Scope (Subt);
-- Inherit the discriminants of the parent type
Add_Discriminants : declare
Num_Disc : Int;
Num_Gird : Int;
begin
Num_Disc := 0;
Old_C := First_Discriminant (Typ);
while Present (Old_C) loop
Num_Disc := Num_Disc + 1;
New_C := Create_Component (Old_C);
Set_Is_Public (New_C, Is_Public (Subt));
Next_Discriminant (Old_C);
end loop;
-- For an untagged derived subtype, the number of discriminants may
-- be smaller than the number of inherited discriminants, because
-- several of them may be renamed by a single new discriminant.
-- In this case, add the hidden discriminants back into the subtype,
-- because otherwise the size of the subtype is computed incorrectly
-- in GCC 4.1.
Num_Gird := 0;
if Is_Derived_Type (Typ)
and then not Is_Tagged_Type (Typ)
then
Old_C := First_Stored_Discriminant (Typ);
while Present (Old_C) loop
Num_Gird := Num_Gird + 1;
Next_Stored_Discriminant (Old_C);
end loop;
end if;
if Num_Gird > Num_Disc then
-- Find out multiple uses of new discriminants, and add hidden
-- components for the extra renamed discriminants. We recognize
-- multiple uses through the Corresponding_Discriminant of a
-- new discriminant: if it constrains several old discriminants,
-- this field points to the last one in the parent type. The
-- stored discriminants of the derived type have the same name
-- as those of the parent.
declare
Constr : Elmt_Id;
New_Discr : Entity_Id;
Old_Discr : Entity_Id;
begin
Constr := First_Elmt (Stored_Constraint (Typ));
Old_Discr := First_Stored_Discriminant (Typ);
while Present (Constr) loop
if Is_Entity_Name (Node (Constr))
and then Ekind (Entity (Node (Constr))) = E_Discriminant
then
New_Discr := Entity (Node (Constr));
if Chars (Corresponding_Discriminant (New_Discr))
/= Chars (Old_Discr)
then
-- The new discriminant has been used to rename
-- a subsequent old discriminant. Introduce a shadow
-- component for the current old discriminant.
New_C := Create_Component (Old_Discr);
Set_Original_Record_Component (New_C, Old_Discr);
end if;
end if;
Next_Elmt (Constr);
Next_Stored_Discriminant (Old_Discr);
end loop;
end;
end if;
end Add_Discriminants;
if Is_Static
and then Is_Variant_Record (Typ)
then
Collect_Fixed_Components (Typ);
Gather_Components (
Typ,
Component_List (Type_Definition (Parent (Typ))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors);
pragma Assert (not Errors);
Create_All_Components;
-- If the subtype declaration is created for a tagged type derivation
-- with constraints, we retrieve the record definition of the parent
-- type to select the components of the proper variant.
elsif Is_Static
and then Is_Tagged_Type (Typ)
and then Nkind (Parent (Typ)) = N_Full_Type_Declaration
and then
Nkind (Type_Definition (Parent (Typ))) = N_Derived_Type_Definition
and then Is_Variant_Record (Parent_Type)
then
Collect_Fixed_Components (Typ);
Gather_Components (
Typ,
Component_List (Type_Definition (Parent (Parent_Type))),
Governed_By => Assoc_List,
Into => Comp_List,
Report_Errors => Errors);
pragma Assert (not Errors);
-- If the tagged derivation has a type extension, collect all the
-- new components therein.
if Present
(Record_Extension_Part (Type_Definition (Parent (Typ))))
then
Old_C := First_Component (Typ);
while Present (Old_C) loop
if Original_Record_Component (Old_C) = Old_C
and then Chars (Old_C) /= Name_uTag
and then Chars (Old_C) /= Name_uParent
and then Chars (Old_C) /= Name_uController
then
Append_Elmt (Old_C, Comp_List);
end if;
Next_Component (Old_C);
end loop;
end if;
Create_All_Components;
else
-- If discriminants are not static, or if this is a multi-level type
-- extension, we have to include all components of the parent type.
Old_C := First_Component (Typ);
while Present (Old_C) loop
New_C := Create_Component (Old_C);
Set_Etype
(New_C,
Constrain_Component_Type
(Old_C, Subt, Decl_Node, Typ, Constraints));
Set_Is_Public (New_C, Is_Public (Subt));
Next_Component (Old_C);
end loop;
end if;
End_Scope;
end Create_Constrained_Components;
------------------------------------------
-- Decimal_Fixed_Point_Type_Declaration --
------------------------------------------
procedure Decimal_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Def);
Digs_Expr : constant Node_Id := Digits_Expression (Def);
Delta_Expr : constant Node_Id := Delta_Expression (Def);
Implicit_Base : Entity_Id;
Digs_Val : Uint;
Delta_Val : Ureal;
Scale_Val : Uint;
Bound_Val : Ureal;
-- Start of processing for Decimal_Fixed_Point_Type_Declaration
begin
Check_Restriction (No_Fixed_Point, Def);
-- Create implicit base type
Implicit_Base :=
Create_Itype (E_Decimal_Fixed_Point_Type, Parent (Def), T, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
-- Analyze and process delta expression
Analyze_And_Resolve (Delta_Expr, Universal_Real);
Check_Delta_Expression (Delta_Expr);
Delta_Val := Expr_Value_R (Delta_Expr);
-- Check delta is power of 10, and determine scale value from it
declare
Val : Ureal;
begin
Scale_Val := Uint_0;
Val := Delta_Val;
if Val < Ureal_1 then
while Val < Ureal_1 loop
Val := Val * Ureal_10;
Scale_Val := Scale_Val + 1;
end loop;
if Scale_Val > 18 then
Error_Msg_N ("scale exceeds maximum value of 18", Def);
Scale_Val := UI_From_Int (+18);
end if;
else
while Val > Ureal_1 loop
Val := Val / Ureal_10;
Scale_Val := Scale_Val - 1;
end loop;
if Scale_Val < -18 then
Error_Msg_N ("scale is less than minimum value of -18", Def);
Scale_Val := UI_From_Int (-18);
end if;
end if;
if Val /= Ureal_1 then
Error_Msg_N ("delta expression must be a power of 10", Def);
Delta_Val := Ureal_10 ** (-Scale_Val);
end if;
end;
-- Set delta, scale and small (small = delta for decimal type)
Set_Delta_Value (Implicit_Base, Delta_Val);
Set_Scale_Value (Implicit_Base, Scale_Val);
Set_Small_Value (Implicit_Base, Delta_Val);
-- Analyze and process digits expression
Analyze_And_Resolve (Digs_Expr, Any_Integer);
Check_Digits_Expression (Digs_Expr);
Digs_Val := Expr_Value (Digs_Expr);
if Digs_Val > 18 then
Digs_Val := UI_From_Int (+18);
Error_Msg_N ("digits value out of range, maximum is 18", Digs_Expr);
end if;
Set_Digits_Value (Implicit_Base, Digs_Val);
Bound_Val := UR_From_Uint (10 ** Digs_Val - 1) * Delta_Val;
-- Set range of base type from digits value for now. This will be
-- expanded to represent the true underlying base range by Freeze.
Set_Fixed_Range (Implicit_Base, Loc, -Bound_Val, Bound_Val);
-- Set size to zero for now, size will be set at freeze time. We have
-- to do this for ordinary fixed-point, because the size depends on
-- the specified small, and we might as well do the same for decimal
-- fixed-point.
Init_Size_Align (Implicit_Base);
-- If there are bounds given in the declaration use them as the
-- bounds of the first named subtype.
if Present (Real_Range_Specification (Def)) then
declare
RRS : constant Node_Id := Real_Range_Specification (Def);
Low : constant Node_Id := Low_Bound (RRS);
High : constant Node_Id := High_Bound (RRS);
Low_Val : Ureal;
High_Val : Ureal;
begin
Analyze_And_Resolve (Low, Any_Real);
Analyze_And_Resolve (High, Any_Real);
Check_Real_Bound (Low);
Check_Real_Bound (High);
Low_Val := Expr_Value_R (Low);
High_Val := Expr_Value_R (High);
if Low_Val < (-Bound_Val) then
Error_Msg_N
("range low bound too small for digits value", Low);
Low_Val := -Bound_Val;
end if;
if High_Val > Bound_Val then
Error_Msg_N
("range high bound too large for digits value", High);
High_Val := Bound_Val;
end if;
Set_Fixed_Range (T, Loc, Low_Val, High_Val);
end;
-- If no explicit range, use range that corresponds to given
-- digits value. This will end up as the final range for the
-- first subtype.
else
Set_Fixed_Range (T, Loc, -Bound_Val, Bound_Val);
end if;
-- Complete entity for first subtype
Set_Ekind (T, E_Decimal_Fixed_Point_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, Implicit_Base);
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Digits_Value (T, Digs_Val);
Set_Delta_Value (T, Delta_Val);
Set_Small_Value (T, Delta_Val);
Set_Scale_Value (T, Scale_Val);
Set_Is_Constrained (T);
end Decimal_Fixed_Point_Type_Declaration;
---------------------------------
-- Derive_Interface_Subprogram --
---------------------------------
procedure Derive_Interface_Subprograms (Derived_Type : Entity_Id) is
procedure Do_Derivation (T : Entity_Id);
-- This inner subprograms is used to climb to the ancestors.
-- It is needed to add the derivations to the Derived_Type.
procedure Do_Derivation (T : Entity_Id) is
Etyp : constant Entity_Id := Etype (T);
AI : Elmt_Id;
begin
if Etyp /= T
and then Is_Interface (Etyp)
then
Do_Derivation (Etyp);
end if;
if Present (Abstract_Interfaces (T))
and then not Is_Empty_Elmt_List (Abstract_Interfaces (T))
then
AI := First_Elmt (Abstract_Interfaces (T));
while Present (AI) loop
if not Is_Ancestor (Node (AI), Derived_Type) then
Derive_Subprograms
(Parent_Type => Node (AI),
Derived_Type => Derived_Type,
No_Predefined_Prims => True);
end if;
Next_Elmt (AI);
end loop;
end if;
end Do_Derivation;
begin
Do_Derivation (Derived_Type);
-- At this point the list of primitive operations of Derived_Type
-- contains the entities corresponding to all the subprograms of all the
-- implemented interfaces. If N interfaces have subprograms with the
-- same profile we have N entities in this list because each one must be
-- allocated in its corresponding virtual table.
-- Its alias attribute references its original interface subprogram.
-- When overridden, the alias attribute is later saved in the
-- Abstract_Interface_Alias attribute.
end Derive_Interface_Subprograms;
-----------------------
-- Derive_Subprogram --
-----------------------
procedure Derive_Subprogram
(New_Subp : in out Entity_Id;
Parent_Subp : Entity_Id;
Derived_Type : Entity_Id;
Parent_Type : Entity_Id;
Actual_Subp : Entity_Id := Empty)
is
Formal : Entity_Id;
New_Formal : Entity_Id;
Visible_Subp : Entity_Id := Parent_Subp;
function Is_Private_Overriding return Boolean;
-- If Subp is a private overriding of a visible operation, the in-
-- herited operation derives from the overridden op (even though
-- its body is the overriding one) and the inherited operation is
-- visible now. See sem_disp to see the details of the handling of
-- the overridden subprogram, which is removed from the list of
-- primitive operations of the type. The overridden subprogram is
-- saved locally in Visible_Subp, and used to diagnose abstract
-- operations that need overriding in the derived type.
procedure Replace_Type (Id, New_Id : Entity_Id);
-- When the type is an anonymous access type, create a new access type
-- designating the derived type.
procedure Set_Derived_Name;
-- This procedure sets the appropriate Chars name for New_Subp. This
-- is normally just a copy of the parent name. An exception arises for
-- type support subprograms, where the name is changed to reflect the
-- name of the derived type, e.g. if type foo is derived from type bar,
-- then a procedure barDA is derived with a name fooDA.
---------------------------
-- Is_Private_Overriding --
---------------------------
function Is_Private_Overriding return Boolean is
Prev : Entity_Id;
begin
-- The visible operation that is overridden is a homonym of the
-- parent subprogram. We scan the homonym chain to find the one
-- whose alias is the subprogram we are deriving.
Prev := Current_Entity (Parent_Subp);
while Present (Prev) loop
if Is_Dispatching_Operation (Parent_Subp)
and then Present (Prev)
and then Ekind (Prev) = Ekind (Parent_Subp)
and then Alias (Prev) = Parent_Subp
and then Scope (Parent_Subp) = Scope (Prev)
and then
(not Is_Hidden (Prev)
or else
-- Ada 2005 (AI-251): Entities associated with overridden
-- interface subprograms are always marked as hidden; in
-- this case the field abstract_interface_alias references
-- the original entity (cf. override_dispatching_operation).
(Atree.Present (Abstract_Interface_Alias (Prev))
and then not Is_Hidden (Abstract_Interface_Alias (Prev))))
then
Visible_Subp := Prev;
return True;
end if;
Prev := Homonym (Prev);
end loop;
return False;
end Is_Private_Overriding;
------------------
-- Replace_Type --
------------------
procedure Replace_Type (Id, New_Id : Entity_Id) is
Acc_Type : Entity_Id;
IR : Node_Id;
Par : constant Node_Id := Parent (Derived_Type);
begin
-- When the type is an anonymous access type, create a new access
-- type designating the derived type. This itype must be elaborated
-- at the point of the derivation, not on subsequent calls that may
-- be out of the proper scope for Gigi, so we insert a reference to
-- it after the derivation.
if Ekind (Etype (Id)) = E_Anonymous_Access_Type then
declare
Desig_Typ : Entity_Id := Designated_Type (Etype (Id));
begin
if Ekind (Desig_Typ) = E_Record_Type_With_Private
and then Present (Full_View (Desig_Typ))
and then not Is_Private_Type (Parent_Type)
then
Desig_Typ := Full_View (Desig_Typ);
end if;
if Base_Type (Desig_Typ) = Base_Type (Parent_Type) then
Acc_Type := New_Copy (Etype (Id));
Set_Etype (Acc_Type, Acc_Type);
Set_Scope (Acc_Type, New_Subp);
-- Compute size of anonymous access type
if Is_Array_Type (Desig_Typ)
and then not Is_Constrained (Desig_Typ)
then
Init_Size (Acc_Type, 2 * System_Address_Size);
else
Init_Size (Acc_Type, System_Address_Size);
end if;
Init_Alignment (Acc_Type);
Set_Directly_Designated_Type (Acc_Type, Derived_Type);
Set_Etype (New_Id, Acc_Type);
Set_Scope (New_Id, New_Subp);
-- Create a reference to it
IR := Make_Itype_Reference (Sloc (Parent (Derived_Type)));
Set_Itype (IR, Acc_Type);
Insert_After (Parent (Derived_Type), IR);
else
Set_Etype (New_Id, Etype (Id));
end if;
end;
elsif Base_Type (Etype (Id)) = Base_Type (Parent_Type)
or else
(Ekind (Etype (Id)) = E_Record_Type_With_Private
and then Present (Full_View (Etype (Id)))
and then
Base_Type (Full_View (Etype (Id))) = Base_Type (Parent_Type))
then
-- Constraint checks on formals are generated during expansion,
-- based on the signature of the original subprogram. The bounds
-- of the derived type are not relevant, and thus we can use
-- the base type for the formals. However, the return type may be
-- used in a context that requires that the proper static bounds
-- be used (a case statement, for example) and for those cases
-- we must use the derived type (first subtype), not its base.
-- If the derived_type_definition has no constraints, we know that
-- the derived type has the same constraints as the first subtype
-- of the parent, and we can also use it rather than its base,
-- which can lead to more efficient code.
if Etype (Id) = Parent_Type then
if Is_Scalar_Type (Parent_Type)
and then
Subtypes_Statically_Compatible (Parent_Type, Derived_Type)
then
Set_Etype (New_Id, Derived_Type);
elsif Nkind (Par) = N_Full_Type_Declaration
and then
Nkind (Type_Definition (Par)) = N_Derived_Type_Definition
and then
Is_Entity_Name
(Subtype_Indication (Type_Definition (Par)))
then
Set_Etype (New_Id, Derived_Type);
else
Set_Etype (New_Id, Base_Type (Derived_Type));
end if;
else
Set_Etype (New_Id, Base_Type (Derived_Type));
end if;
else
Set_Etype (New_Id, Etype (Id));
end if;
end Replace_Type;
----------------------
-- Set_Derived_Name --
----------------------
procedure Set_Derived_Name is
Nm : constant TSS_Name_Type := Get_TSS_Name (Parent_Subp);
begin
if Nm = TSS_Null then
Set_Chars (New_Subp, Chars (Parent_Subp));
else
Set_Chars (New_Subp, Make_TSS_Name (Base_Type (Derived_Type), Nm));
end if;
end Set_Derived_Name;
-- Start of processing for Derive_Subprogram
begin
New_Subp :=
New_Entity (Nkind (Parent_Subp), Sloc (Derived_Type));
Set_Ekind (New_Subp, Ekind (Parent_Subp));
-- Check whether the inherited subprogram is a private operation that
-- should be inherited but not yet made visible. Such subprograms can
-- become visible at a later point (e.g., the private part of a public
-- child unit) via Declare_Inherited_Private_Subprograms. If the
-- following predicate is true, then this is not such a private
-- operation and the subprogram simply inherits the name of the parent
-- subprogram. Note the special check for the names of controlled
-- operations, which are currently exempted from being inherited with
-- a hidden name because they must be findable for generation of
-- implicit run-time calls.
if not Is_Hidden (Parent_Subp)
or else Is_Internal (Parent_Subp)
or else Is_Private_Overriding
or else Is_Internal_Name (Chars (Parent_Subp))
or else Chars (Parent_Subp) = Name_Initialize
or else Chars (Parent_Subp) = Name_Adjust
or else Chars (Parent_Subp) = Name_Finalize
then
Set_Derived_Name;
-- If parent is hidden, this can be a regular derivation if the
-- parent is immediately visible in a non-instantiating context,
-- or if we are in the private part of an instance. This test
-- should still be refined ???
-- The test for In_Instance_Not_Visible avoids inheriting the derived
-- operation as a non-visible operation in cases where the parent
-- subprogram might not be visible now, but was visible within the
-- original generic, so it would be wrong to make the inherited
-- subprogram non-visible now. (Not clear if this test is fully
-- correct; are there any cases where we should declare the inherited
-- operation as not visible to avoid it being overridden, e.g., when
-- the parent type is a generic actual with private primitives ???)
-- (they should be treated the same as other private inherited
-- subprograms, but it's not clear how to do this cleanly). ???
elsif (In_Open_Scopes (Scope (Base_Type (Parent_Type)))
and then Is_Immediately_Visible (Parent_Subp)
and then not In_Instance)
or else In_Instance_Not_Visible
then
Set_Derived_Name;
-- The type is inheriting a private operation, so enter
-- it with a special name so it can't be overridden.
else
Set_Chars (New_Subp, New_External_Name (Chars (Parent_Subp), 'P'));
end if;
Set_Parent (New_Subp, Parent (Derived_Type));
Replace_Type (Parent_Subp, New_Subp);
Conditional_Delay (New_Subp, Parent_Subp);
Formal := First_Formal (Parent_Subp);
while Present (Formal) loop
New_Formal := New_Copy (Formal);
-- Normally we do not go copying parents, but in the case of
-- formals, we need to link up to the declaration (which is the
-- parameter specification), and it is fine to link up to the
-- original formal's parameter specification in this case.
Set_Parent (New_Formal, Parent (Formal));
Append_Entity (New_Formal, New_Subp);
Replace_Type (Formal, New_Formal);
Next_Formal (Formal);
end loop;
-- If this derivation corresponds to a tagged generic actual, then
-- primitive operations rename those of the actual. Otherwise the
-- primitive operations rename those of the parent type, If the
-- parent renames an intrinsic operator, so does the new subprogram.
-- We except concatenation, which is always properly typed, and does
-- not get expanded as other intrinsic operations.
if No (Actual_Subp) then
if Is_Intrinsic_Subprogram (Parent_Subp) then
Set_Is_Intrinsic_Subprogram (New_Subp);
if Present (Alias (Parent_Subp))
and then Chars (Parent_Subp) /= Name_Op_Concat
then
Set_Alias (New_Subp, Alias (Parent_Subp));
else
Set_Alias (New_Subp, Parent_Subp);
end if;
else
Set_Alias (New_Subp, Parent_Subp);
end if;
else
Set_Alias (New_Subp, Actual_Subp);
end if;
-- Derived subprograms of a tagged type must inherit the convention
-- of the parent subprogram (a requirement of AI-117). Derived
-- subprograms of untagged types simply get convention Ada by default.
if Is_Tagged_Type (Derived_Type) then
Set_Convention (New_Subp, Convention (Parent_Subp));
end if;
Set_Is_Imported (New_Subp, Is_Imported (Parent_Subp));
Set_Is_Exported (New_Subp, Is_Exported (Parent_Subp));
if Ekind (Parent_Subp) = E_Procedure then
Set_Is_Valued_Procedure
(New_Subp, Is_Valued_Procedure (Parent_Subp));
end if;
-- No_Return must be inherited properly. If this is overridden in the
-- case of a dispatching operation, then a check is made in Sem_Disp
-- that the overriding operation is also No_Return (no such check is
-- required for the case of non-dispatching operation.
Set_No_Return (New_Subp, No_Return (Parent_Subp));
-- A derived function with a controlling result is abstract. If the
-- Derived_Type is a nonabstract formal generic derived type, then
-- inherited operations are not abstract: the required check is done at
-- instantiation time. If the derivation is for a generic actual, the
-- function is not abstract unless the actual is.
if Is_Generic_Type (Derived_Type)
and then not Is_Abstract (Derived_Type)
then
null;
elsif Is_Abstract (Alias (New_Subp))
or else (Is_Tagged_Type (Derived_Type)
and then Etype (New_Subp) = Derived_Type
and then No (Actual_Subp))
then
Set_Is_Abstract (New_Subp);
-- Finally, if the parent type is abstract we must verify that all
-- inherited operations are either non-abstract or overridden, or
-- that the derived type itself is abstract (this check is performed
-- at the end of a package declaration, in Check_Abstract_Overriding).
-- A private overriding in the parent type will not be visible in the
-- derivation if we are not in an inner package or in a child unit of
-- the parent type, in which case the abstractness of the inherited
-- operation is carried to the new subprogram.
elsif Is_Abstract (Parent_Type)
and then not In_Open_Scopes (Scope (Parent_Type))
and then Is_Private_Overriding
and then Is_Abstract (Visible_Subp)
then
Set_Alias (New_Subp, Visible_Subp);
Set_Is_Abstract (New_Subp);
end if;
New_Overloaded_Entity (New_Subp, Derived_Type);
-- Check for case of a derived subprogram for the instantiation of a
-- formal derived tagged type, if so mark the subprogram as dispatching
-- and inherit the dispatching attributes of the parent subprogram. The
-- derived subprogram is effectively renaming of the actual subprogram,
-- so it needs to have the same attributes as the actual.
if Present (Actual_Subp)
and then Is_Dispatching_Operation (Parent_Subp)
then
Set_Is_Dispatching_Operation (New_Subp);
if Present (DTC_Entity (Parent_Subp)) then
Set_DTC_Entity (New_Subp, DTC_Entity (Parent_Subp));
Set_DT_Position (New_Subp, DT_Position (Parent_Subp));
end if;
end if;
-- Indicate that a derived subprogram does not require a body and that
-- it does not require processing of default expressions.
Set_Has_Completion (New_Subp);
Set_Default_Expressions_Processed (New_Subp);
if Ekind (New_Subp) = E_Function then
Set_Mechanism (New_Subp, Mechanism (Parent_Subp));
end if;
end Derive_Subprogram;
------------------------
-- Derive_Subprograms --
------------------------
procedure Derive_Subprograms
(Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Generic_Actual : Entity_Id := Empty;
No_Predefined_Prims : Boolean := False)
is
Op_List : constant Elist_Id :=
Collect_Primitive_Operations (Parent_Type);
Act_List : Elist_Id;
Act_Elmt : Elmt_Id;
Elmt : Elmt_Id;
Is_Predef : Boolean;
Subp : Entity_Id;
New_Subp : Entity_Id := Empty;
Parent_Base : Entity_Id;
begin
if Ekind (Parent_Type) = E_Record_Type_With_Private
and then Has_Discriminants (Parent_Type)
and then Present (Full_View (Parent_Type))
then
Parent_Base := Full_View (Parent_Type);
else
Parent_Base := Parent_Type;
end if;
if Present (Generic_Actual) then
Act_List := Collect_Primitive_Operations (Generic_Actual);
Act_Elmt := First_Elmt (Act_List);
else
Act_Elmt := No_Elmt;
end if;
-- Literals are derived earlier in the process of building the derived
-- type, and are skipped here.
Elmt := First_Elmt (Op_List);
while Present (Elmt) loop
Subp := Node (Elmt);
if Ekind (Subp) /= E_Enumeration_Literal then
Is_Predef :=
Is_Dispatching_Operation (Subp)
and then Is_Predefined_Dispatching_Operation (Subp);
if No_Predefined_Prims and then Is_Predef then
null;
-- We don't need to derive alias entities associated with
-- abstract interfaces
elsif Is_Dispatching_Operation (Subp)
and then Present (Alias (Subp))
and then Present (Abstract_Interface_Alias (Subp))
then
null;
elsif No (Generic_Actual) then
Derive_Subprogram
(New_Subp, Subp, Derived_Type, Parent_Base);
else
Derive_Subprogram (New_Subp, Subp,
Derived_Type, Parent_Base, Node (Act_Elmt));
Next_Elmt (Act_Elmt);
end if;
end if;
Next_Elmt (Elmt);
end loop;
end Derive_Subprograms;
--------------------------------
-- Derived_Standard_Character --
--------------------------------
procedure Derived_Standard_Character
(N : Node_Id;
Parent_Type : Entity_Id;
Derived_Type : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Indic : constant Node_Id := Subtype_Indication (Def);
Parent_Base : constant Entity_Id := Base_Type (Parent_Type);
Implicit_Base : constant Entity_Id :=
Create_Itype
(E_Enumeration_Type, N, Derived_Type, 'B');
Lo : Node_Id;
Hi : Node_Id;
begin
Discard_Node (Process_Subtype (Indic, N));
Set_Etype (Implicit_Base, Parent_Base);
Set_Size_Info (Implicit_Base, Root_Type (Parent_Type));
Set_RM_Size (Implicit_Base, RM_Size (Root_Type (Parent_Type)));
Set_Is_Character_Type (Implicit_Base, True);
Set_Has_Delayed_Freeze (Implicit_Base);
-- The bounds of the implicit base are the bounds of the parent base.
-- Note that their type is the parent base.
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Base));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Base));
Set_Scalar_Range (Implicit_Base,
Make_Range (Loc,
Low_Bound => Lo,
High_Bound => Hi));
Conditional_Delay (Derived_Type, Parent_Type);
Set_Ekind (Derived_Type, E_Enumeration_Subtype);
Set_Etype (Derived_Type, Implicit_Base);
Set_Size_Info (Derived_Type, Parent_Type);
if Unknown_RM_Size (Derived_Type) then
Set_RM_Size (Derived_Type, RM_Size (Parent_Type));
end if;
Set_Is_Character_Type (Derived_Type, True);
if Nkind (Indic) /= N_Subtype_Indication then
-- If no explicit constraint, the bounds are those
-- of the parent type.
Lo := New_Copy_Tree (Type_Low_Bound (Parent_Type));
Hi := New_Copy_Tree (Type_High_Bound (Parent_Type));
Set_Scalar_Range (Derived_Type, Make_Range (Loc, Lo, Hi));
end if;
Convert_Scalar_Bounds (N, Parent_Type, Derived_Type, Loc);
-- Because the implicit base is used in the conversion of the bounds,
-- we have to freeze it now. This is similar to what is done for
-- numeric types, and it equally suspicious, but otherwise a non-
-- static bound will have a reference to an unfrozen type, which is
-- rejected by Gigi (???).
Freeze_Before (N, Implicit_Base);
end Derived_Standard_Character;
------------------------------
-- Derived_Type_Declaration --
------------------------------
procedure Derived_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Is_Completion : Boolean)
is
Def : constant Node_Id := Type_Definition (N);
Iface_Def : Node_Id;
Indic : constant Node_Id := Subtype_Indication (Def);
Extension : constant Node_Id := Record_Extension_Part (Def);
Parent_Type : Entity_Id;
Parent_Scope : Entity_Id;
Taggd : Boolean;
function Comes_From_Generic (Typ : Entity_Id) return Boolean;
-- Check whether the parent type is a generic formal, or derives
-- directly or indirectly from one.
------------------------
-- Comes_From_Generic --
------------------------
function Comes_From_Generic (Typ : Entity_Id) return Boolean is
begin
if Is_Generic_Type (Typ) then
return True;
elsif Is_Generic_Type (Root_Type (Parent_Type)) then
return True;
elsif Is_Private_Type (Typ)
and then Present (Full_View (Typ))
and then Is_Generic_Type (Root_Type (Full_View (Typ)))
then
return True;
elsif Is_Generic_Actual_Type (Typ) then
return True;
else
return False;
end if;
end Comes_From_Generic;
-- Start of processing for Derived_Type_Declaration
begin
Parent_Type := Find_Type_Of_Subtype_Indic (Indic);
-- Ada 2005 (AI-251): In case of interface derivation check that the
-- parent is also an interface.
if Interface_Present (Def) then
if not Is_Interface (Parent_Type) then
Error_Msg_NE ("(Ada 2005) & must be an interface",
Indic, Parent_Type);
else
Iface_Def := Type_Definition (Parent (Parent_Type));
-- Ada 2005 (AI-251): Limited interfaces can only inherit from
-- other limited interfaces.
if Limited_Present (Def) then
if Limited_Present (Iface_Def) then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) limited interface cannot" &
" inherit from protected interface", Indic);
elsif Synchronized_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) limited interface cannot" &
" inherit from synchronized interface", Indic);
elsif Task_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) limited interface cannot" &
" inherit from task interface", Indic);
else
Error_Msg_N ("(Ada 2005) limited interface cannot" &
" inherit from non-limited interface", Indic);
end if;
-- Ada 2005 (AI-345): Non-limited interfaces can only inherit
-- from non-limited or limited interfaces.
elsif not Protected_Present (Def)
and then not Synchronized_Present (Def)
and then not Task_Present (Def)
then
if Limited_Present (Iface_Def) then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) non-limited interface cannot" &
" inherit from protected interface", Indic);
elsif Synchronized_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) non-limited interface cannot" &
" inherit from synchronized interface", Indic);
elsif Task_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) non-limited interface cannot" &
" inherit from task interface", Indic);
else
null;
end if;
end if;
end if;
end if;
-- Ada 2005 (AI-251): Decorate all the names in the list of ancestor
-- interfaces
if Is_Tagged_Type (Parent_Type)
and then Is_Non_Empty_List (Interface_List (Def))
then
declare
Intf : Node_Id;
T : Entity_Id;
begin
Intf := First (Interface_List (Def));
while Present (Intf) loop
T := Find_Type_Of_Subtype_Indic (Intf);
if not Is_Interface (T) then
Error_Msg_NE ("(Ada 2005) & must be an interface", Intf, T);
elsif Limited_Present (Def)
and then not Is_Limited_Interface (T)
then
Error_Msg_NE
("progenitor interface& of limited type must be limited",
N, T);
end if;
Next (Intf);
end loop;
end;
end if;
if Parent_Type = Any_Type
or else Etype (Parent_Type) = Any_Type
or else (Is_Class_Wide_Type (Parent_Type)
and then Etype (Parent_Type) = T)
then
-- If Parent_Type is undefined or illegal, make new type into a
-- subtype of Any_Type, and set a few attributes to prevent cascaded
-- errors. If this is a self-definition, emit error now.
if T = Parent_Type
or else T = Etype (Parent_Type)
then
Error_Msg_N ("type cannot be used in its own definition", Indic);
end if;
Set_Ekind (T, Ekind (Parent_Type));
Set_Etype (T, Any_Type);
Set_Scalar_Range (T, Scalar_Range (Any_Type));
if Is_Tagged_Type (T) then
Set_Primitive_Operations (T, New_Elmt_List);
end if;
return;
end if;
-- Ada 2005 (AI-251): The case in which the parent of the full-view is
-- an interface is special because the list of interfaces in the full
-- view can be given in any order. For example:
-- type A is interface;
-- type B is interface and A;
-- type D is new B with private;
-- private
-- type D is new A and B with null record; -- 1 --
-- In this case we perform the following transformation of -1-:
-- type D is new B and A with null record;
-- If the parent of the full-view covers the parent of the partial-view
-- we have two possible cases:
-- 1) They have the same parent
-- 2) The parent of the full-view implements some further interfaces
-- In both cases we do not need to perform the transformation. In the
-- first case the source program is correct and the transformation is
-- not needed; in the second case the source program does not fulfill
-- the no-hidden interfaces rule (AI-396) and the error will be reported
-- later.
-- This transformation not only simplifies the rest of the analysis of
-- this type declaration but also simplifies the correct generation of
-- the object layout to the expander.
if In_Private_Part (Current_Scope)
and then Is_Interface (Parent_Type)
then
declare
Iface : Node_Id;
Partial_View : Entity_Id;
Partial_View_Parent : Entity_Id;
New_Iface : Node_Id;
begin
-- Look for the associated private type declaration
Partial_View := First_Entity (Current_Scope);
loop
exit when No (Partial_View)
or else (Has_Private_Declaration (Partial_View)
and then Full_View (Partial_View) = T);
Next_Entity (Partial_View);
end loop;
-- If the partial view was not found then the source code has
-- errors and the transformation is not needed.
if Present (Partial_View) then
Partial_View_Parent := Etype (Partial_View);
-- If the parent of the full-view covers the parent of the
-- partial-view we have nothing else to do.
if Interface_Present_In_Ancestor
(Parent_Type, Partial_View_Parent)
then
null;
-- Traverse the list of interfaces of the full-view to look
-- for the parent of the partial-view and perform the tree
-- transformation.
else
Iface := First (Interface_List (Def));
while Present (Iface) loop
if Etype (Iface) = Etype (Partial_View) then
Rewrite (Subtype_Indication (Def),
New_Copy (Subtype_Indication
(Parent (Partial_View))));
New_Iface := Make_Identifier (Sloc (N),
Chars (Parent_Type));
Append (New_Iface, Interface_List (Def));
-- Analyze the transformed code
Derived_Type_Declaration (T, N, Is_Completion);
return;
end if;
Next (Iface);
end loop;
end if;
end if;
end;
end if;
-- Only composite types other than array types are allowed to have
-- discriminants.
if Present (Discriminant_Specifications (N))
and then (Is_Elementary_Type (Parent_Type)
or else Is_Array_Type (Parent_Type))
and then not Error_Posted (N)
then
Error_Msg_N
("elementary or array type cannot have discriminants",
Defining_Identifier (First (Discriminant_Specifications (N))));
Set_Has_Discriminants (T, False);
end if;
-- In Ada 83, a derived type defined in a package specification cannot
-- be used for further derivation until the end of its visible part.
-- Note that derivation in the private part of the package is allowed.
if Ada_Version = Ada_83
and then Is_Derived_Type (Parent_Type)
and then In_Visible_Part (Scope (Parent_Type))
then
if Ada_Version = Ada_83 and then Comes_From_Source (Indic) then
Error_Msg_N
("(Ada 83): premature use of type for derivation", Indic);
end if;
end if;
-- Check for early use of incomplete or private type
if Ekind (Parent_Type) = E_Void
or else Ekind (Parent_Type) = E_Incomplete_Type
then
Error_Msg_N ("premature derivation of incomplete type", Indic);
return;
elsif (Is_Incomplete_Or_Private_Type (Parent_Type)
and then not Comes_From_Generic (Parent_Type))
or else Has_Private_Component (Parent_Type)
then
-- The ancestor type of a formal type can be incomplete, in which
-- case only the operations of the partial view are available in
-- the generic. Subsequent checks may be required when the full
-- view is analyzed, to verify that derivation from a tagged type
-- has an extension.
if Nkind (Original_Node (N)) = N_Formal_Type_Declaration then
null;
elsif No (Underlying_Type (Parent_Type))
or else Has_Private_Component (Parent_Type)
then
Error_Msg_N
("premature derivation of derived or private type", Indic);
-- Flag the type itself as being in error, this prevents some
-- nasty problems with subsequent uses of the malformed type.
Set_Error_Posted (T);
-- Check that within the immediate scope of an untagged partial
-- view it's illegal to derive from the partial view if the
-- full view is tagged. (7.3(7))
-- We verify that the Parent_Type is a partial view by checking
-- that it is not a Full_Type_Declaration (i.e. a private type or
-- private extension declaration), to distinguish a partial view
-- from a derivation from a private type which also appears as
-- E_Private_Type.
elsif Present (Full_View (Parent_Type))
and then Nkind (Parent (Parent_Type)) /= N_Full_Type_Declaration
and then not Is_Tagged_Type (Parent_Type)
and then Is_Tagged_Type (Full_View (Parent_Type))
then
Parent_Scope := Scope (T);
while Present (Parent_Scope)
and then Parent_Scope /= Standard_Standard
loop
if Parent_Scope = Scope (Parent_Type) then
Error_Msg_N
("premature derivation from type with tagged full view",
Indic);
end if;
Parent_Scope := Scope (Parent_Scope);
end loop;
end if;
end if;
-- Check that form of derivation is appropriate
Taggd := Is_Tagged_Type (Parent_Type);
-- Perhaps the parent type should be changed to the class-wide type's
-- specific type in this case to prevent cascading errors ???
if Present (Extension) and then Is_Class_Wide_Type (Parent_Type) then
Error_Msg_N ("parent type must not be a class-wide type", Indic);
return;
end if;
if Present (Extension) and then not Taggd then
Error_Msg_N
("type derived from untagged type cannot have extension", Indic);
elsif No (Extension) and then Taggd then
-- If this declaration is within a private part (or body) of a
-- generic instantiation then the derivation is allowed (the parent
-- type can only appear tagged in this case if it's a generic actual
-- type, since it would otherwise have been rejected in the analysis
-- of the generic template).
if not Is_Generic_Actual_Type (Parent_Type)
or else In_Visible_Part (Scope (Parent_Type))
then
Error_Msg_N
("type derived from tagged type must have extension", Indic);
end if;
end if;
Build_Derived_Type (N, Parent_Type, T, Is_Completion);
-- AI-419: the parent type of an explicitly limited derived type must
-- be a limited type or a limited interface.
if Limited_Present (Def) then
Set_Is_Limited_Record (T);
if Is_Interface (T) then
Set_Is_Limited_Interface (T);
end if;
if not Is_Limited_Type (Parent_Type)
and then
(not Is_Interface (Parent_Type)
or else not Is_Limited_Interface (Parent_Type))
then
Error_Msg_NE ("parent type& of limited type must be limited",
N, Parent_Type);
end if;
end if;
end Derived_Type_Declaration;
----------------------------------
-- Enumeration_Type_Declaration --
----------------------------------
procedure Enumeration_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Ev : Uint;
L : Node_Id;
R_Node : Node_Id;
B_Node : Node_Id;
begin
-- Create identifier node representing lower bound
B_Node := New_Node (N_Identifier, Sloc (Def));
L := First (Literals (Def));
Set_Chars (B_Node, Chars (L));
Set_Entity (B_Node, L);
Set_Etype (B_Node, T);
Set_Is_Static_Expression (B_Node, True);
R_Node := New_Node (N_Range, Sloc (Def));
Set_Low_Bound (R_Node, B_Node);
Set_Ekind (T, E_Enumeration_Type);
Set_First_Literal (T, L);
Set_Etype (T, T);
Set_Is_Constrained (T);
Ev := Uint_0;
-- Loop through literals of enumeration type setting pos and rep values
-- except that if the Ekind is already set, then it means that the
-- literal was already constructed (case of a derived type declaration
-- and we should not disturb the Pos and Rep values.
while Present (L) loop
if Ekind (L) /= E_Enumeration_Literal then
Set_Ekind (L, E_Enumeration_Literal);
Set_Enumeration_Pos (L, Ev);
Set_Enumeration_Rep (L, Ev);
Set_Is_Known_Valid (L, True);
end if;
Set_Etype (L, T);
New_Overloaded_Entity (L);
Generate_Definition (L);
Set_Convention (L, Convention_Intrinsic);
if Nkind (L) = N_Defining_Character_Literal then
Set_Is_Character_Type (T, True);
end if;
Ev := Ev + 1;
Next (L);
end loop;
-- Now create a node representing upper bound
B_Node := New_Node (N_Identifier, Sloc (Def));
Set_Chars (B_Node, Chars (Last (Literals (Def))));
Set_Entity (B_Node, Last (Literals (Def)));
Set_Etype (B_Node, T);
Set_Is_Static_Expression (B_Node, True);
Set_High_Bound (R_Node, B_Node);
Set_Scalar_Range (T, R_Node);
Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
Set_Enum_Esize (T);
-- Set Discard_Names if configuration pragma set, or if there is
-- a parameterless pragma in the current declarative region
if Global_Discard_Names
or else Discard_Names (Scope (T))
then
Set_Discard_Names (T);
end if;
-- Process end label if there is one
if Present (Def) then
Process_End_Label (Def, 'e', T);
end if;
end Enumeration_Type_Declaration;
---------------------------------
-- Expand_To_Stored_Constraint --
---------------------------------
function Expand_To_Stored_Constraint
(Typ : Entity_Id;
Constraint : Elist_Id) return Elist_Id
is
Explicitly_Discriminated_Type : Entity_Id;
Expansion : Elist_Id;
Discriminant : Entity_Id;
function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id;
-- Find the nearest type that actually specifies discriminants
---------------------------------
-- Type_With_Explicit_Discrims --
---------------------------------
function Type_With_Explicit_Discrims (Id : Entity_Id) return Entity_Id is
Typ : constant E := Base_Type (Id);
begin
if Ekind (Typ) in Incomplete_Or_Private_Kind then
if Present (Full_View (Typ)) then
return Type_With_Explicit_Discrims (Full_View (Typ));
end if;
else
if Has_Discriminants (Typ) then
return Typ;
end if;
end if;
if Etype (Typ) = Typ then
return Empty;
elsif Has_Discriminants (Typ) then
return Typ;
else
return Type_With_Explicit_Discrims (Etype (Typ));
end if;
end Type_With_Explicit_Discrims;
-- Start of processing for Expand_To_Stored_Constraint
begin
if No (Constraint)
or else Is_Empty_Elmt_List (Constraint)
then
return No_Elist;
end if;
Explicitly_Discriminated_Type := Type_With_Explicit_Discrims (Typ);
if No (Explicitly_Discriminated_Type) then
return No_Elist;
end if;
Expansion := New_Elmt_List;
Discriminant :=
First_Stored_Discriminant (Explicitly_Discriminated_Type);
while Present (Discriminant) loop
Append_Elmt (
Get_Discriminant_Value (
Discriminant, Explicitly_Discriminated_Type, Constraint),
Expansion);
Next_Stored_Discriminant (Discriminant);
end loop;
return Expansion;
end Expand_To_Stored_Constraint;
--------------------
-- Find_Type_Name --
--------------------
function Find_Type_Name (N : Node_Id) return Entity_Id is
Id : constant Entity_Id := Defining_Identifier (N);
Prev : Entity_Id;
New_Id : Entity_Id;
Prev_Par : Node_Id;
begin
-- Find incomplete declaration, if one was given
Prev := Current_Entity_In_Scope (Id);
if Present (Prev) then
-- Previous declaration exists. Error if not incomplete/private case
-- except if previous declaration is implicit, etc. Enter_Name will
-- emit error if appropriate.
Prev_Par := Parent (Prev);
if not Is_Incomplete_Or_Private_Type (Prev) then
Enter_Name (Id);
New_Id := Id;
elsif Nkind (N) /= N_Full_Type_Declaration
and then Nkind (N) /= N_Task_Type_Declaration
and then Nkind (N) /= N_Protected_Type_Declaration
then
-- Completion must be a full type declarations (RM 7.3(4))
Error_Msg_Sloc := Sloc (Prev);
Error_Msg_NE ("invalid completion of }", Id, Prev);
-- Set scope of Id to avoid cascaded errors. Entity is never
-- examined again, except when saving globals in generics.
Set_Scope (Id, Current_Scope);
New_Id := Id;
-- Case of full declaration of incomplete type
elsif Ekind (Prev) = E_Incomplete_Type then
-- Indicate that the incomplete declaration has a matching full
-- declaration. The defining occurrence of the incomplete
-- declaration remains the visible one, and the procedure
-- Get_Full_View dereferences it whenever the type is used.
if Present (Full_View (Prev)) then
Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
end if;
Set_Full_View (Prev, Id);
Append_Entity (Id, Current_Scope);
Set_Is_Public (Id, Is_Public (Prev));
Set_Is_Internal (Id);
New_Id := Prev;
-- Case of full declaration of private type
else
if Nkind (Parent (Prev)) /= N_Private_Extension_Declaration then
if Etype (Prev) /= Prev then
-- Prev is a private subtype or a derived type, and needs
-- no completion.
Error_Msg_NE ("invalid redeclaration of }", Id, Prev);
New_Id := Id;
elsif Ekind (Prev) = E_Private_Type
and then
(Nkind (N) = N_Task_Type_Declaration
or else Nkind (N) = N_Protected_Type_Declaration)
then
Error_Msg_N
("completion of nonlimited type cannot be limited", N);
elsif Ekind (Prev) = E_Record_Type_With_Private
and then
(Nkind (N) = N_Task_Type_Declaration
or else Nkind (N) = N_Protected_Type_Declaration)
then
if not Is_Limited_Record (Prev) then
Error_Msg_N
("completion of nonlimited type cannot be limited", N);
elsif No (Interface_List (N)) then
Error_Msg_N
("completion of tagged private type must be tagged",
N);
end if;
end if;
-- Ada 2005 (AI-251): Private extension declaration of a
-- task type. This case arises with tasks implementing interfaces
elsif Nkind (N) = N_Task_Type_Declaration
or else Nkind (N) = N_Protected_Type_Declaration
then
null;
elsif Nkind (N) /= N_Full_Type_Declaration
or else Nkind (Type_Definition (N)) /= N_Derived_Type_Definition
then
Error_Msg_N
("full view of private extension must be an extension", N);
elsif not (Abstract_Present (Parent (Prev)))
and then Abstract_Present (Type_Definition (N))
then
Error_Msg_N
("full view of non-abstract extension cannot be abstract", N);
end if;
if not In_Private_Part (Current_Scope) then
Error_Msg_N
("declaration of full view must appear in private part", N);
end if;
Copy_And_Swap (Prev, Id);
Set_Has_Private_Declaration (Prev);
Set_Has_Private_Declaration (Id);
-- If no error, propagate freeze_node from private to full view.
-- It may have been generated for an early operational item.
if Present (Freeze_Node (Id))
and then Serious_Errors_Detected = 0
and then No (Full_View (Id))
then
Set_Freeze_Node (Prev, Freeze_Node (Id));
Set_Freeze_Node (Id, Empty);
Set_First_Rep_Item (Prev, First_Rep_Item (Id));
end if;
Set_Full_View (Id, Prev);
New_Id := Prev;
end if;
-- Verify that full declaration conforms to incomplete one
if Is_Incomplete_Or_Private_Type (Prev)
and then Present (Discriminant_Specifications (Prev_Par))
then
if Present (Discriminant_Specifications (N)) then
if Ekind (Prev) = E_Incomplete_Type then
Check_Discriminant_Conformance (N, Prev, Prev);
else
Check_Discriminant_Conformance (N, Prev, Id);
end if;
else
Error_Msg_N
("missing discriminants in full type declaration", N);
-- To avoid cascaded errors on subsequent use, share the
-- discriminants of the partial view.
Set_Discriminant_Specifications (N,
Discriminant_Specifications (Prev_Par));
end if;
end if;
-- A prior untagged private type can have an associated class-wide
-- type due to use of the class attribute, and in this case also the
-- full type is required to be tagged.
if Is_Type (Prev)
and then (Is_Tagged_Type (Prev)
or else Present (Class_Wide_Type (Prev)))
and then (Nkind (N) /= N_Task_Type_Declaration
and then Nkind (N) /= N_Protected_Type_Declaration)
then
-- The full declaration is either a tagged record or an
-- extension otherwise this is an error
if Nkind (Type_Definition (N)) = N_Record_Definition then
if not Tagged_Present (Type_Definition (N)) then
Error_Msg_NE
("full declaration of } must be tagged", Prev, Id);
Set_Is_Tagged_Type (Id);
Set_Primitive_Operations (Id, New_Elmt_List);
end if;
elsif Nkind (Type_Definition (N)) = N_Derived_Type_Definition then
if No (Record_Extension_Part (Type_Definition (N))) then
Error_Msg_NE (
"full declaration of } must be a record extension",
Prev, Id);
Set_Is_Tagged_Type (Id);
Set_Primitive_Operations (Id, New_Elmt_List);
end if;
else
Error_Msg_NE
("full declaration of } must be a tagged type", Prev, Id);
end if;
end if;
return New_Id;
else
-- New type declaration
Enter_Name (Id);
return Id;
end if;
end Find_Type_Name;
-------------------------
-- Find_Type_Of_Object --
-------------------------
function Find_Type_Of_Object
(Obj_Def : Node_Id;
Related_Nod : Node_Id) return Entity_Id
is
Def_Kind : constant Node_Kind := Nkind (Obj_Def);
P : Node_Id := Parent (Obj_Def);
T : Entity_Id;
Nam : Name_Id;
begin
-- If the parent is a component_definition node we climb to the
-- component_declaration node
if Nkind (P) = N_Component_Definition then
P := Parent (P);
end if;
-- Case of an anonymous array subtype
if Def_Kind = N_Constrained_Array_Definition
or else Def_Kind = N_Unconstrained_Array_Definition
then
T := Empty;
Array_Type_Declaration (T, Obj_Def);
-- Create an explicit subtype whenever possible
elsif Nkind (P) /= N_Component_Declaration
and then Def_Kind = N_Subtype_Indication
then
-- Base name of subtype on object name, which will be unique in
-- the current scope.
-- If this is a duplicate declaration, return base type, to avoid
-- generating duplicate anonymous types.
if Error_Posted (P) then
Analyze (Subtype_Mark (Obj_Def));
return Entity (Subtype_Mark (Obj_Def));
end if;
Nam :=
New_External_Name
(Chars (Defining_Identifier (Related_Nod)), 'S', 0, 'T');
T := Make_Defining_Identifier (Sloc (P), Nam);
Insert_Action (Obj_Def,
Make_Subtype_Declaration (Sloc (P),
Defining_Identifier => T,
Subtype_Indication => Relocate_Node (Obj_Def)));
-- This subtype may need freezing, and this will not be done
-- automatically if the object declaration is not in declarative
-- part. Since this is an object declaration, the type cannot always
-- be frozen here. Deferred constants do not freeze their type
-- (which often enough will be private).
if Nkind (P) = N_Object_Declaration
and then Constant_Present (P)
and then No (Expression (P))
then
null;
else
Insert_Actions (Obj_Def, Freeze_Entity (T, Sloc (P)));
end if;
-- Ada 2005 AI-406: the object definition in an object declaration
-- can be an access definition.
elsif Def_Kind = N_Access_Definition then
T := Access_Definition (Related_Nod, Obj_Def);
Set_Is_Local_Anonymous_Access (T);
-- comment here, what cases ???
else
T := Process_Subtype (Obj_Def, Related_Nod);
end if;
return T;
end Find_Type_Of_Object;
--------------------------------
-- Find_Type_Of_Subtype_Indic --
--------------------------------
function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id is
Typ : Entity_Id;
begin
-- Case of subtype mark with a constraint
if Nkind (S) = N_Subtype_Indication then
Find_Type (Subtype_Mark (S));
Typ := Entity (Subtype_Mark (S));
if not
Is_Valid_Constraint_Kind (Ekind (Typ), Nkind (Constraint (S)))
then
Error_Msg_N
("incorrect constraint for this kind of type", Constraint (S));
Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
end if;
-- Otherwise we have a subtype mark without a constraint
elsif Error_Posted (S) then
Rewrite (S, New_Occurrence_Of (Any_Id, Sloc (S)));
return Any_Type;
else
Find_Type (S);
Typ := Entity (S);
end if;
if Typ = Standard_Wide_Character
or else Typ = Standard_Wide_Wide_Character
or else Typ = Standard_Wide_String
or else Typ = Standard_Wide_Wide_String
then
Check_Restriction (No_Wide_Characters, S);
end if;
return Typ;
end Find_Type_Of_Subtype_Indic;
-------------------------------------
-- Floating_Point_Type_Declaration --
-------------------------------------
procedure Floating_Point_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Digs : constant Node_Id := Digits_Expression (Def);
Digs_Val : Uint;
Base_Typ : Entity_Id;
Implicit_Base : Entity_Id;
Bound : Node_Id;
function Can_Derive_From (E : Entity_Id) return Boolean;
-- Find if given digits value allows derivation from specified type
---------------------
-- Can_Derive_From --
---------------------
function Can_Derive_From (E : Entity_Id) return Boolean is
Spec : constant Entity_Id := Real_Range_Specification (Def);
begin
if Digs_Val > Digits_Value (E) then
return False;
end if;
if Present (Spec) then
if Expr_Value_R (Type_Low_Bound (E)) >
Expr_Value_R (Low_Bound (Spec))
then
return False;
end if;
if Expr_Value_R (Type_High_Bound (E)) <
Expr_Value_R (High_Bound (Spec))
then
return False;
end if;
end if;
return True;
end Can_Derive_From;
-- Start of processing for Floating_Point_Type_Declaration
begin
Check_Restriction (No_Floating_Point, Def);
-- Create an implicit base type
Implicit_Base :=
Create_Itype (E_Floating_Point_Type, Parent (Def), T, 'B');
-- Analyze and verify digits value
Analyze_And_Resolve (Digs, Any_Integer);
Check_Digits_Expression (Digs);
Digs_Val := Expr_Value (Digs);
-- Process possible range spec and find correct type to derive from
Process_Real_Range_Specification (Def);
if Can_Derive_From (Standard_Short_Float) then
Base_Typ := Standard_Short_Float;
elsif Can_Derive_From (Standard_Float) then
Base_Typ := Standard_Float;
elsif Can_Derive_From (Standard_Long_Float) then
Base_Typ := Standard_Long_Float;
elsif Can_Derive_From (Standard_Long_Long_Float) then
Base_Typ := Standard_Long_Long_Float;
-- If we can't derive from any existing type, use long_long_float
-- and give appropriate message explaining the problem.
else
Base_Typ := Standard_Long_Long_Float;
if Digs_Val >= Digits_Value (Standard_Long_Long_Float) then
Error_Msg_Uint_1 := Digits_Value (Standard_Long_Long_Float);
Error_Msg_N ("digits value out of range, maximum is ^", Digs);
else
Error_Msg_N
("range too large for any predefined type",
Real_Range_Specification (Def));
end if;
end if;
-- If there are bounds given in the declaration use them as the bounds
-- of the type, otherwise use the bounds of the predefined base type
-- that was chosen based on the Digits value.
if Present (Real_Range_Specification (Def)) then
Set_Scalar_Range (T, Real_Range_Specification (Def));
Set_Is_Constrained (T);
-- The bounds of this range must be converted to machine numbers
-- in accordance with RM 4.9(38).
Bound := Type_Low_Bound (T);
if Nkind (Bound) = N_Real_Literal then
Set_Realval
(Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
Set_Is_Machine_Number (Bound);
end if;
Bound := Type_High_Bound (T);
if Nkind (Bound) = N_Real_Literal then
Set_Realval
(Bound, Machine (Base_Typ, Realval (Bound), Round, Bound));
Set_Is_Machine_Number (Bound);
end if;
else
Set_Scalar_Range (T, Scalar_Range (Base_Typ));
end if;
-- Complete definition of implicit base and declared first subtype
Set_Etype (Implicit_Base, Base_Typ);
Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
Set_Size_Info (Implicit_Base, (Base_Typ));
Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
Set_Digits_Value (Implicit_Base, Digits_Value (Base_Typ));
Set_Vax_Float (Implicit_Base, Vax_Float (Base_Typ));
Set_Ekind (T, E_Floating_Point_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, (Implicit_Base));
Set_RM_Size (T, RM_Size (Implicit_Base));
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Digits_Value (T, Digs_Val);
end Floating_Point_Type_Declaration;
----------------------------
-- Get_Discriminant_Value --
----------------------------
-- This is the situation:
-- There is a non-derived type
-- type T0 (Dx, Dy, Dz...)
-- There are zero or more levels of derivation, with each derivation
-- either purely inheriting the discriminants, or defining its own.
-- type Ti is new Ti-1
-- or
-- type Ti (Dw) is new Ti-1(Dw, 1, X+Y)
-- or
-- subtype Ti is ...
-- The subtype issue is avoided by the use of Original_Record_Component,
-- and the fact that derived subtypes also derive the constraints.
-- This chain leads back from
-- Typ_For_Constraint
-- Typ_For_Constraint has discriminants, and the value for each
-- discriminant is given by its corresponding Elmt of Constraints.
-- Discriminant is some discriminant in this hierarchy
-- We need to return its value
-- We do this by recursively searching each level, and looking for
-- Discriminant. Once we get to the bottom, we start backing up
-- returning the value for it which may in turn be a discriminant
-- further up, so on the backup we continue the substitution.
function Get_Discriminant_Value
(Discriminant : Entity_Id;
Typ_For_Constraint : Entity_Id;
Constraint : Elist_Id) return Node_Id
is
function Search_Derivation_Levels
(Ti : Entity_Id;
Discrim_Values : Elist_Id;
Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id;
-- This is the routine that performs the recursive search of levels
-- as described above.
------------------------------
-- Search_Derivation_Levels --
------------------------------
function Search_Derivation_Levels
(Ti : Entity_Id;
Discrim_Values : Elist_Id;
Stored_Discrim_Values : Boolean) return Node_Or_Entity_Id
is
Assoc : Elmt_Id;
Disc : Entity_Id;
Result : Node_Or_Entity_Id;
Result_Entity : Node_Id;
begin
-- If inappropriate type, return Error, this happens only in
-- cascaded error situations, and we want to avoid a blow up.
if not Is_Composite_Type (Ti) or else Is_Array_Type (Ti) then
return Error;
end if;
-- Look deeper if possible. Use Stored_Constraints only for
-- untagged types. For tagged types use the given constraint.
-- This asymmetry needs explanation???
if not Stored_Discrim_Values
and then Present (Stored_Constraint (Ti))
and then not Is_Tagged_Type (Ti)
then
Result :=
Search_Derivation_Levels (Ti, Stored_Constraint (Ti), True);
else
declare
Td : constant Entity_Id := Etype (Ti);
begin
if Td = Ti then
Result := Discriminant;
else
if Present (Stored_Constraint (Ti)) then
Result :=
Search_Derivation_Levels
(Td, Stored_Constraint (Ti), True);
else
Result :=
Search_Derivation_Levels
(Td, Discrim_Values, Stored_Discrim_Values);
end if;
end if;
end;
end if;
-- Extra underlying places to search, if not found above. For
-- concurrent types, the relevant discriminant appears in the
-- corresponding record. For a type derived from a private type
-- without discriminant, the full view inherits the discriminants
-- of the full view of the parent.
if Result = Discriminant then
if Is_Concurrent_Type (Ti)
and then Present (Corresponding_Record_Type (Ti))
then
Result :=
Search_Derivation_Levels (
Corresponding_Record_Type (Ti),
Discrim_Values,
Stored_Discrim_Values);
elsif Is_Private_Type (Ti)
and then not Has_Discriminants (Ti)
and then Present (Full_View (Ti))
and then Etype (Full_View (Ti)) /= Ti
then
Result :=
Search_Derivation_Levels (
Full_View (Ti),
Discrim_Values,
Stored_Discrim_Values);
end if;
end if;
-- If Result is not a (reference to a) discriminant, return it,
-- otherwise set Result_Entity to the discriminant.
if Nkind (Result) = N_Defining_Identifier then
pragma Assert (Result = Discriminant);
Result_Entity := Result;
else
if not Denotes_Discriminant (Result) then
return Result;
end if;
Result_Entity := Entity (Result);
end if;
-- See if this level of derivation actually has discriminants
-- because tagged derivations can add them, hence the lower
-- levels need not have any.
if not Has_Discriminants (Ti) then
return Result;
end if;
-- Scan Ti's discriminants for Result_Entity,
-- and return its corresponding value, if any.
Result_Entity := Original_Record_Component (Result_Entity);
Assoc := First_Elmt (Discrim_Values);
if Stored_Discrim_Values then
Disc := First_Stored_Discriminant (Ti);
else
Disc := First_Discriminant (Ti);
end if;
while Present (Disc) loop
pragma Assert (Present (Assoc));
if Original_Record_Component (Disc) = Result_Entity then
return Node (Assoc);
end if;
Next_Elmt (Assoc);
if Stored_Discrim_Values then
Next_Stored_Discriminant (Disc);
else
Next_Discriminant (Disc);
end if;
end loop;
-- Could not find it
--
return Result;
end Search_Derivation_Levels;
Result : Node_Or_Entity_Id;
-- Start of processing for Get_Discriminant_Value
begin
-- ??? This routine is a gigantic mess and will be deleted. For the
-- time being just test for the trivial case before calling recurse.
if Base_Type (Scope (Discriminant)) = Base_Type (Typ_For_Constraint) then
declare
D : Entity_Id;
E : Elmt_Id;
begin
D := First_Discriminant (Typ_For_Constraint);
E := First_Elmt (Constraint);
while Present (D) loop
if Chars (D) = Chars (Discriminant) then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end;
end if;
Result := Search_Derivation_Levels
(Typ_For_Constraint, Constraint, False);
-- ??? hack to disappear when this routine is gone
if Nkind (Result) = N_Defining_Identifier then
declare
D : Entity_Id;
E : Elmt_Id;
begin
D := First_Discriminant (Typ_For_Constraint);
E := First_Elmt (Constraint);
while Present (D) loop
if Corresponding_Discriminant (D) = Discriminant then
return Node (E);
end if;
Next_Discriminant (D);
Next_Elmt (E);
end loop;
end;
end if;
pragma Assert (Nkind (Result) /= N_Defining_Identifier);
return Result;
end Get_Discriminant_Value;
--------------------------
-- Has_Range_Constraint --
--------------------------
function Has_Range_Constraint (N : Node_Id) return Boolean is
C : constant Node_Id := Constraint (N);
begin
if Nkind (C) = N_Range_Constraint then
return True;
elsif Nkind (C) = N_Digits_Constraint then
return
Is_Decimal_Fixed_Point_Type (Entity (Subtype_Mark (N)))
or else
Present (Range_Constraint (C));
elsif Nkind (C) = N_Delta_Constraint then
return Present (Range_Constraint (C));
else
return False;
end if;
end Has_Range_Constraint;
------------------------
-- Inherit_Components --
------------------------
function Inherit_Components
(N : Node_Id;
Parent_Base : Entity_Id;
Derived_Base : Entity_Id;
Is_Tagged : Boolean;
Inherit_Discr : Boolean;
Discs : Elist_Id) return Elist_Id
is
Assoc_List : constant Elist_Id := New_Elmt_List;
procedure Inherit_Component
(Old_C : Entity_Id;
Plain_Discrim : Boolean := False;
Stored_Discrim : Boolean := False);
-- Inherits component Old_C from Parent_Base to the Derived_Base. If
-- Plain_Discrim is True, Old_C is a discriminant. If Stored_Discrim is
-- True, Old_C is a stored discriminant. If they are both false then
-- Old_C is a regular component.
-----------------------
-- Inherit_Component --
-----------------------
procedure Inherit_Component
(Old_C : Entity_Id;
Plain_Discrim : Boolean := False;
Stored_Discrim : Boolean := False)
is
New_C : constant Entity_Id := New_Copy (Old_C);
Discrim : Entity_Id;
Corr_Discrim : Entity_Id;
begin
pragma Assert (not Is_Tagged or else not Stored_Discrim);
Set_Parent (New_C, Parent (Old_C));
-- Regular discriminants and components must be inserted
-- in the scope of the Derived_Base. Do it here.
if not Stored_Discrim then
Enter_Name (New_C);
end if;
-- For tagged types the Original_Record_Component must point to
-- whatever this field was pointing to in the parent type. This has
-- already been achieved by the call to New_Copy above.
if not Is_Tagged then
Set_Original_Record_Component (New_C, New_C);
end if;
-- If we have inherited a component then see if its Etype contains
-- references to Parent_Base discriminants. In this case, replace
-- these references with the constraints given in Discs. We do not
-- do this for the partial view of private types because this is
-- not needed (only the components of the full view will be used
-- for code generation) and cause problem. We also avoid this
-- transformation in some error situations.
if Ekind (New_C) = E_Component then
if (Is_Private_Type (Derived_Base)
and then not Is_Generic_Type (Derived_Base))
or else (Is_Empty_Elmt_List (Discs)
and then not Expander_Active)
then
Set_Etype (New_C, Etype (Old_C));
else
Set_Etype
(New_C,
Constrain_Component_Type
(Old_C, Derived_Base, N, Parent_Base, Discs));
end if;
end if;
-- In derived tagged types it is illegal to reference a non
-- discriminant component in the parent type. To catch this, mark
-- these components with an Ekind of E_Void. This will be reset in
-- Record_Type_Definition after processing the record extension of
-- the derived type.
if Is_Tagged and then Ekind (New_C) = E_Component then
Set_Ekind (New_C, E_Void);
end if;
if Plain_Discrim then
Set_Corresponding_Discriminant (New_C, Old_C);
Build_Discriminal (New_C);
-- If we are explicitly inheriting a stored discriminant it will be
-- completely hidden.
elsif Stored_Discrim then
Set_Corresponding_Discriminant (New_C, Empty);
Set_Discriminal (New_C, Empty);
Set_Is_Completely_Hidden (New_C);
-- Set the Original_Record_Component of each discriminant in the
-- derived base to point to the corresponding stored that we just
-- created.
Discrim := First_Discriminant (Derived_Base);
while Present (Discrim) loop
Corr_Discrim := Corresponding_Discriminant (Discrim);
-- Corr_Discrim could be missing in an error situation
if Present (Corr_Discrim)
and then Original_Record_Component (Corr_Discrim) = Old_C
then
Set_Original_Record_Component (Discrim, New_C);
end if;
Next_Discriminant (Discrim);
end loop;
Append_Entity (New_C, Derived_Base);
end if;
if not Is_Tagged then
Append_Elmt (Old_C, Assoc_List);
Append_Elmt (New_C, Assoc_List);
end if;
end Inherit_Component;
-- Variables local to Inherit_Component
Loc : constant Source_Ptr := Sloc (N);
Parent_Discrim : Entity_Id;
Stored_Discrim : Entity_Id;
D : Entity_Id;
Component : Entity_Id;
-- Start of processing for Inherit_Components
begin
if not Is_Tagged then
Append_Elmt (Parent_Base, Assoc_List);
Append_Elmt (Derived_Base, Assoc_List);
end if;
-- Inherit parent discriminants if needed
if Inherit_Discr then
Parent_Discrim := First_Discriminant (Parent_Base);
while Present (Parent_Discrim) loop
Inherit_Component (Parent_Discrim, Plain_Discrim => True);
Next_Discriminant (Parent_Discrim);
end loop;
end if;
-- Create explicit stored discrims for untagged types when necessary
if not Has_Unknown_Discriminants (Derived_Base)
and then Has_Discriminants (Parent_Base)
and then not Is_Tagged
and then
(not Inherit_Discr
or else First_Discriminant (Parent_Base) /=
First_Stored_Discriminant (Parent_Base))
then
Stored_Discrim := First_Stored_Discriminant (Parent_Base);
while Present (Stored_Discrim) loop
Inherit_Component (Stored_Discrim, Stored_Discrim => True);
Next_Stored_Discriminant (Stored_Discrim);
end loop;
end if;
-- See if we can apply the second transformation for derived types, as
-- explained in point 6. in the comments above Build_Derived_Record_Type
-- This is achieved by appending Derived_Base discriminants into Discs,
-- which has the side effect of returning a non empty Discs list to the
-- caller of Inherit_Components, which is what we want. This must be
-- done for private derived types if there are explicit stored
-- discriminants, to ensure that we can retrieve the values of the
-- constraints provided in the ancestors.
if Inherit_Discr
and then Is_Empty_Elmt_List (Discs)
and then Present (First_Discriminant (Derived_Base))
and then
(not Is_Private_Type (Derived_Base)
or else Is_Completely_Hidden
(First_Stored_Discriminant (Derived_Base))
or else Is_Generic_Type (Derived_Base))
then
D := First_Discriminant (Derived_Base);
while Present (D) loop
Append_Elmt (New_Reference_To (D, Loc), Discs);
Next_Discriminant (D);
end loop;
end if;
-- Finally, inherit non-discriminant components unless they are not
-- visible because defined or inherited from the full view of the
-- parent. Don't inherit the _parent field of the parent type.
Component := First_Entity (Parent_Base);
while Present (Component) loop
-- Ada 2005 (AI-251): Do not inherit tags corresponding with the
-- interfaces of the parent
if Ekind (Component) = E_Component
and then Is_Tag (Component)
and then RTE_Available (RE_Interface_Tag)
and then Etype (Component) = RTE (RE_Interface_Tag)
then
null;
elsif Ekind (Component) /= E_Component
or else Chars (Component) = Name_uParent
then
null;
-- If the derived type is within the parent type's declarative
-- region, then the components can still be inherited even though
-- they aren't visible at this point. This can occur for cases
-- such as within public child units where the components must
-- become visible upon entering the child unit's private part.
elsif not Is_Visible_Component (Component)
and then not In_Open_Scopes (Scope (Parent_Base))
then
null;
elsif Ekind (Derived_Base) = E_Private_Type
or else Ekind (Derived_Base) = E_Limited_Private_Type
then
null;
else
Inherit_Component (Component);
end if;
Next_Entity (Component);
end loop;
-- For tagged derived types, inherited discriminants cannot be used in
-- component declarations of the record extension part. To achieve this
-- we mark the inherited discriminants as not visible.
if Is_Tagged and then Inherit_Discr then
D := First_Discriminant (Derived_Base);
while Present (D) loop
Set_Is_Immediately_Visible (D, False);
Next_Discriminant (D);
end loop;
end if;
return Assoc_List;
end Inherit_Components;
-----------------------
-- Is_Null_Extension --
-----------------------
function Is_Null_Extension (T : Entity_Id) return Boolean is
Full_Type_Decl : constant Node_Id := Parent (T);
Full_Type_Defn : constant Node_Id := Type_Definition (Full_Type_Decl);
Comp_List : Node_Id;
First_Comp : Node_Id;
begin
if not Is_Tagged_Type (T)
or else Nkind (Full_Type_Defn) /= N_Derived_Type_Definition
then
return False;
end if;
Comp_List := Component_List (Record_Extension_Part (Full_Type_Defn));
if Present (Discriminant_Specifications (Full_Type_Decl)) then
return False;
elsif Present (Comp_List)
and then Is_Non_Empty_List (Component_Items (Comp_List))
then
First_Comp := First (Component_Items (Comp_List));
return Chars (Defining_Identifier (First_Comp)) = Name_uParent
and then No (Next (First_Comp));
else
return True;
end if;
end Is_Null_Extension;
------------------------------
-- Is_Valid_Constraint_Kind --
------------------------------
function Is_Valid_Constraint_Kind
(T_Kind : Type_Kind;
Constraint_Kind : Node_Kind) return Boolean
is
begin
case T_Kind is
when Enumeration_Kind |
Integer_Kind =>
return Constraint_Kind = N_Range_Constraint;
when Decimal_Fixed_Point_Kind =>
return
Constraint_Kind = N_Digits_Constraint
or else
Constraint_Kind = N_Range_Constraint;
when Ordinary_Fixed_Point_Kind =>
return
Constraint_Kind = N_Delta_Constraint
or else
Constraint_Kind = N_Range_Constraint;
when Float_Kind =>
return
Constraint_Kind = N_Digits_Constraint
or else
Constraint_Kind = N_Range_Constraint;
when Access_Kind |
Array_Kind |
E_Record_Type |
E_Record_Subtype |
Class_Wide_Kind |
E_Incomplete_Type |
Private_Kind |
Concurrent_Kind =>
return Constraint_Kind = N_Index_Or_Discriminant_Constraint;
when others =>
return True; -- Error will be detected later
end case;
end Is_Valid_Constraint_Kind;
--------------------------
-- Is_Visible_Component --
--------------------------
function Is_Visible_Component (C : Entity_Id) return Boolean is
Original_Comp : Entity_Id := Empty;
Original_Scope : Entity_Id;
Type_Scope : Entity_Id;
function Is_Local_Type (Typ : Entity_Id) return Boolean;
-- Check whether parent type of inherited component is declared locally,
-- possibly within a nested package or instance. The current scope is
-- the derived record itself.
-------------------
-- Is_Local_Type --
-------------------
function Is_Local_Type (Typ : Entity_Id) return Boolean is
Scop : Entity_Id;
begin
Scop := Scope (Typ);
while Present (Scop)
and then Scop /= Standard_Standard
loop
if Scop = Scope (Current_Scope) then
return True;
end if;
Scop := Scope (Scop);
end loop;
return False;
end Is_Local_Type;
-- Start of processing for Is_Visible_Component
begin
if Ekind (C) = E_Component
or else Ekind (C) = E_Discriminant
then
Original_Comp := Original_Record_Component (C);
end if;
if No (Original_Comp) then
-- Premature usage, or previous error
return False;
else
Original_Scope := Scope (Original_Comp);
Type_Scope := Scope (Base_Type (Scope (C)));
end if;
-- This test only concerns tagged types
if not Is_Tagged_Type (Original_Scope) then
return True;
-- If it is _Parent or _Tag, there is no visibility issue
elsif not Comes_From_Source (Original_Comp) then
return True;
-- If we are in the body of an instantiation, the component is visible
-- even when the parent type (possibly defined in an enclosing unit or
-- in a parent unit) might not.
elsif In_Instance_Body then
return True;
-- Discriminants are always visible
elsif Ekind (Original_Comp) = E_Discriminant
and then not Has_Unknown_Discriminants (Original_Scope)
then
return True;
-- If the component has been declared in an ancestor which is currently
-- a private type, then it is not visible. The same applies if the
-- component's containing type is not in an open scope and the original
-- component's enclosing type is a visible full type of a private type
-- (which can occur in cases where an attempt is being made to reference
-- a component in a sibling package that is inherited from a visible
-- component of a type in an ancestor package; the component in the
-- sibling package should not be visible even though the component it
-- inherited from is visible). This does not apply however in the case
-- where the scope of the type is a private child unit, or when the
-- parent comes from a local package in which the ancestor is currently
-- visible. The latter suppression of visibility is needed for cases
-- that are tested in B730006.
elsif Is_Private_Type (Original_Scope)
or else
(not Is_Private_Descendant (Type_Scope)
and then not In_Open_Scopes (Type_Scope)
and then Has_Private_Declaration (Original_Scope))
then
-- If the type derives from an entity in a formal package, there
-- are no additional visible components.
if Nkind (Original_Node (Unit_Declaration_Node (Type_Scope))) =
N_Formal_Package_Declaration
then
return False;
-- if we are not in the private part of the current package, there
-- are no additional visible components.
elsif Ekind (Scope (Current_Scope)) = E_Package
and then not In_Private_Part (Scope (Current_Scope))
then
return False;
else
return
Is_Child_Unit (Cunit_Entity (Current_Sem_Unit))
and then Is_Local_Type (Type_Scope);
end if;
-- There is another weird way in which a component may be invisible
-- when the private and the full view are not derived from the same
-- ancestor. Here is an example :
-- type A1 is tagged record F1 : integer; end record;
-- type A2 is new A1 with record F2 : integer; end record;
-- type T is new A1 with private;
-- private
-- type T is new A2 with null record;
-- In this case, the full view of T inherits F1 and F2 but the private
-- view inherits only F1
else
declare
Ancestor : Entity_Id := Scope (C);
begin
loop
if Ancestor = Original_Scope then
return True;
elsif Ancestor = Etype (Ancestor) then
return False;
end if;
Ancestor := Etype (Ancestor);
end loop;
-- LLVM local deleted unreachable line
end;
end if;
end Is_Visible_Component;
--------------------------
-- Make_Class_Wide_Type --
--------------------------
procedure Make_Class_Wide_Type (T : Entity_Id) is
CW_Type : Entity_Id;
CW_Name : Name_Id;
Next_E : Entity_Id;
begin
-- The class wide type can have been defined by the partial view in
-- which case everything is already done
if Present (Class_Wide_Type (T)) then
return;
end if;
CW_Type :=
New_External_Entity (E_Void, Scope (T), Sloc (T), T, 'C', 0, 'T');
-- Inherit root type characteristics
CW_Name := Chars (CW_Type);
Next_E := Next_Entity (CW_Type);
Copy_Node (T, CW_Type);
Set_Comes_From_Source (CW_Type, False);
Set_Chars (CW_Type, CW_Name);
Set_Parent (CW_Type, Parent (T));
Set_Next_Entity (CW_Type, Next_E);
Set_Has_Delayed_Freeze (CW_Type);
-- Customize the class-wide type: It has no prim. op., it cannot be
-- abstract and its Etype points back to the specific root type.
Set_Ekind (CW_Type, E_Class_Wide_Type);
Set_Is_Tagged_Type (CW_Type, True);
Set_Primitive_Operations (CW_Type, New_Elmt_List);
Set_Is_Abstract (CW_Type, False);
Set_Is_Constrained (CW_Type, False);
Set_Is_First_Subtype (CW_Type, Is_First_Subtype (T));
Init_Size_Align (CW_Type);
if Ekind (T) = E_Class_Wide_Subtype then
Set_Etype (CW_Type, Etype (Base_Type (T)));
else
Set_Etype (CW_Type, T);
end if;
-- If this is the class_wide type of a constrained subtype, it does
-- not have discriminants.
Set_Has_Discriminants (CW_Type,
Has_Discriminants (T) and then not Is_Constrained (T));
Set_Has_Unknown_Discriminants (CW_Type, True);
Set_Class_Wide_Type (T, CW_Type);
Set_Equivalent_Type (CW_Type, Empty);
-- The class-wide type of a class-wide type is itself (RM 3.9(14))
Set_Class_Wide_Type (CW_Type, CW_Type);
end Make_Class_Wide_Type;
----------------
-- Make_Index --
----------------
procedure Make_Index
(I : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix_Index : Nat := 1)
is
R : Node_Id;
T : Entity_Id;
Def_Id : Entity_Id := Empty;
Found : Boolean := False;
begin
-- For a discrete range used in a constrained array definition and
-- defined by a range, an implicit conversion to the predefined type
-- INTEGER is assumed if each bound is either a numeric literal, a named
-- number, or an attribute, and the type of both bounds (prior to the
-- implicit conversion) is the type universal_integer. Otherwise, both
-- bounds must be of the same discrete type, other than universal
-- integer; this type must be determinable independently of the
-- context, but using the fact that the type must be discrete and that
-- both bounds must have the same type.
-- Character literals also have a universal type in the absence of
-- of additional context, and are resolved to Standard_Character.
if Nkind (I) = N_Range then
-- The index is given by a range constraint. The bounds are known
-- to be of a consistent type.
if not Is_Overloaded (I) then
T := Etype (I);
-- If the bounds are universal, choose the specific predefined
-- type.
if T = Universal_Integer then
T := Standard_Integer;
elsif T = Any_Character then
if Ada_Version >= Ada_95 then
Error_Msg_N
("ambiguous character literals (could be Wide_Character)",
I);
end if;
T := Standard_Character;
end if;
else
T := Any_Type;
declare
Ind : Interp_Index;
It : Interp;
begin
Get_First_Interp (I, Ind, It);
while Present (It.Typ) loop
if Is_Discrete_Type (It.Typ) then
if Found
and then not Covers (It.Typ, T)
and then not Covers (T, It.Typ)
then
Error_Msg_N ("ambiguous bounds in discrete range", I);
exit;
else
T := It.Typ;
Found := True;
end if;
end if;
Get_Next_Interp (Ind, It);
end loop;
if T = Any_Type then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
elsif T = Universal_Integer then
T := Standard_Integer;
end if;
end;
end if;
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
end if;
if Nkind (Low_Bound (I)) = N_Attribute_Reference
and then Attribute_Name (Low_Bound (I)) = Name_First
and then Is_Entity_Name (Prefix (Low_Bound (I)))
and then Is_Type (Entity (Prefix (Low_Bound (I))))
and then Is_Discrete_Type (Entity (Prefix (Low_Bound (I))))
then
-- The type of the index will be the type of the prefix, as long
-- as the upper bound is 'Last of the same type.
Def_Id := Entity (Prefix (Low_Bound (I)));
if Nkind (High_Bound (I)) /= N_Attribute_Reference
or else Attribute_Name (High_Bound (I)) /= Name_Last
or else not Is_Entity_Name (Prefix (High_Bound (I)))
or else Entity (Prefix (High_Bound (I))) /= Def_Id
then
Def_Id := Empty;
end if;
end if;
R := I;
Process_Range_Expr_In_Decl (R, T);
elsif Nkind (I) = N_Subtype_Indication then
-- The index is given by a subtype with a range constraint
T := Base_Type (Entity (Subtype_Mark (I)));
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
end if;
R := Range_Expression (Constraint (I));
Resolve (R, T);
Process_Range_Expr_In_Decl (R, Entity (Subtype_Mark (I)));
elsif Nkind (I) = N_Attribute_Reference then
-- The parser guarantees that the attribute is a RANGE attribute
-- If the node denotes the range of a type mark, that is also the
-- resulting type, and we do no need to create an Itype for it.
if Is_Entity_Name (Prefix (I))
and then Comes_From_Source (I)
and then Is_Type (Entity (Prefix (I)))
and then Is_Discrete_Type (Entity (Prefix (I)))
then
Def_Id := Entity (Prefix (I));
end if;
Analyze_And_Resolve (I);
T := Etype (I);
R := I;
-- If none of the above, must be a subtype. We convert this to a
-- range attribute reference because in the case of declared first
-- named subtypes, the types in the range reference can be different
-- from the type of the entity. A range attribute normalizes the
-- reference and obtains the correct types for the bounds.
-- This transformation is in the nature of an expansion, is only
-- done if expansion is active. In particular, it is not done on
-- formal generic types, because we need to retain the name of the
-- original index for instantiation purposes.
else
if not Is_Entity_Name (I) or else not Is_Type (Entity (I)) then
Error_Msg_N ("invalid subtype mark in discrete range ", I);
Set_Etype (I, Any_Integer);
return;
else
-- The type mark may be that of an incomplete type. It is only
-- now that we can get the full view, previous analysis does
-- not look specifically for a type mark.
Set_Entity (I, Get_Full_View (Entity (I)));
Set_Etype (I, Entity (I));
Def_Id := Entity (I);
if not Is_Discrete_Type (Def_Id) then
Error_Msg_N ("discrete type required for index", I);
Set_Etype (I, Any_Type);
return;
end if;
end if;
if Expander_Active then
Rewrite (I,
Make_Attribute_Reference (Sloc (I),
Attribute_Name => Name_Range,
Prefix => Relocate_Node (I)));
-- The original was a subtype mark that does not freeze. This
-- means that the rewritten version must not freeze either.
Set_Must_Not_Freeze (I);
Set_Must_Not_Freeze (Prefix (I));
-- Is order critical??? if so, document why, if not
-- use Analyze_And_Resolve
Analyze (I);
T := Etype (I);
Resolve (I);
R := I;
-- If expander is inactive, type is legal, nothing else to construct
else
return;
end if;
end if;
if not Is_Discrete_Type (T) then
Error_Msg_N ("discrete type required for range", I);
Set_Etype (I, Any_Type);
return;
elsif T = Any_Type then
Set_Etype (I, Any_Type);
return;
end if;
-- We will now create the appropriate Itype to describe the range, but
-- first a check. If we originally had a subtype, then we just label
-- the range with this subtype. Not only is there no need to construct
-- a new subtype, but it is wrong to do so for two reasons:
-- 1. A legality concern, if we have a subtype, it must not freeze,
-- and the Itype would cause freezing incorrectly
-- 2. An efficiency concern, if we created an Itype, it would not be
-- recognized as the same type for the purposes of eliminating
-- checks in some circumstances.
-- We signal this case by setting the subtype entity in Def_Id
if No (Def_Id) then
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, 'D', Suffix_Index);
Set_Etype (Def_Id, Base_Type (T));
if Is_Signed_Integer_Type (T) then
Set_Ekind (Def_Id, E_Signed_Integer_Subtype);
elsif Is_Modular_Integer_Type (T) then
Set_Ekind (Def_Id, E_Modular_Integer_Subtype);
else
Set_Ekind (Def_Id, E_Enumeration_Subtype);
Set_Is_Character_Type (Def_Id, Is_Character_Type (T));
Set_First_Literal (Def_Id, First_Literal (T));
end if;
Set_Size_Info (Def_Id, (T));
Set_RM_Size (Def_Id, RM_Size (T));
Set_First_Rep_Item (Def_Id, First_Rep_Item (T));
Set_Scalar_Range (Def_Id, R);
Conditional_Delay (Def_Id, T);
-- In the subtype indication case, if the immediate parent of the
-- new subtype is non-static, then the subtype we create is non-
-- static, even if its bounds are static.
if Nkind (I) = N_Subtype_Indication
and then not Is_Static_Subtype (Entity (Subtype_Mark (I)))
then
Set_Is_Non_Static_Subtype (Def_Id);
end if;
end if;
-- Final step is to label the index with this constructed type
Set_Etype (I, Def_Id);
end Make_Index;
------------------------------
-- Modular_Type_Declaration --
------------------------------
procedure Modular_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Mod_Expr : constant Node_Id := Expression (Def);
M_Val : Uint;
procedure Set_Modular_Size (Bits : Int);
-- Sets RM_Size to Bits, and Esize to normal word size above this
----------------------
-- Set_Modular_Size --
----------------------
procedure Set_Modular_Size (Bits : Int) is
begin
Set_RM_Size (T, UI_From_Int (Bits));
if Bits <= 8 then
Init_Esize (T, 8);
elsif Bits <= 16 then
Init_Esize (T, 16);
elsif Bits <= 32 then
Init_Esize (T, 32);
else
Init_Esize (T, System_Max_Binary_Modulus_Power);
end if;
end Set_Modular_Size;
-- Start of processing for Modular_Type_Declaration
begin
Analyze_And_Resolve (Mod_Expr, Any_Integer);
Set_Etype (T, T);
Set_Ekind (T, E_Modular_Integer_Type);
Init_Alignment (T);
Set_Is_Constrained (T);
if not Is_OK_Static_Expression (Mod_Expr) then
Flag_Non_Static_Expr
("non-static expression used for modular type bound!", Mod_Expr);
M_Val := 2 ** System_Max_Binary_Modulus_Power;
else
M_Val := Expr_Value (Mod_Expr);
end if;
if M_Val < 1 then
Error_Msg_N ("modulus value must be positive", Mod_Expr);
M_Val := 2 ** System_Max_Binary_Modulus_Power;
end if;
Set_Modulus (T, M_Val);
-- Create bounds for the modular type based on the modulus given in
-- the type declaration and then analyze and resolve those bounds.
Set_Scalar_Range (T,
Make_Range (Sloc (Mod_Expr),
Low_Bound =>
Make_Integer_Literal (Sloc (Mod_Expr), 0),
High_Bound =>
Make_Integer_Literal (Sloc (Mod_Expr), M_Val - 1)));
-- Properly analyze the literals for the range. We do this manually
-- because we can't go calling Resolve, since we are resolving these
-- bounds with the type, and this type is certainly not complete yet!
Set_Etype (Low_Bound (Scalar_Range (T)), T);
Set_Etype (High_Bound (Scalar_Range (T)), T);
Set_Is_Static_Expression (Low_Bound (Scalar_Range (T)));
Set_Is_Static_Expression (High_Bound (Scalar_Range (T)));
-- Loop through powers of two to find number of bits required
for Bits in Int range 0 .. System_Max_Binary_Modulus_Power loop
-- Binary case
if M_Val = 2 ** Bits then
Set_Modular_Size (Bits);
return;
-- Non-binary case
elsif M_Val < 2 ** Bits then
Set_Non_Binary_Modulus (T);
if Bits > System_Max_Nonbinary_Modulus_Power then
Error_Msg_Uint_1 :=
UI_From_Int (System_Max_Nonbinary_Modulus_Power);
Error_Msg_N
("nonbinary modulus exceeds limit (2 '*'*^ - 1)", Mod_Expr);
Set_Modular_Size (System_Max_Binary_Modulus_Power);
return;
else
-- In the non-binary case, set size as per RM 13.3(55)
Set_Modular_Size (Bits);
return;
end if;
end if;
end loop;
-- If we fall through, then the size exceed System.Max_Binary_Modulus
-- so we just signal an error and set the maximum size.
Error_Msg_Uint_1 := UI_From_Int (System_Max_Binary_Modulus_Power);
Error_Msg_N ("modulus exceeds limit (2 '*'*^)", Mod_Expr);
Set_Modular_Size (System_Max_Binary_Modulus_Power);
Init_Alignment (T);
end Modular_Type_Declaration;
--------------------------
-- New_Concatenation_Op --
--------------------------
procedure New_Concatenation_Op (Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (Typ);
Op : Entity_Id;
function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id;
-- Create abbreviated declaration for the formal of a predefined
-- Operator 'Op' of type 'Typ'
--------------------
-- Make_Op_Formal --
--------------------
function Make_Op_Formal (Typ, Op : Entity_Id) return Entity_Id is
Formal : Entity_Id;
begin
Formal := New_Internal_Entity (E_In_Parameter, Op, Loc, 'P');
Set_Etype (Formal, Typ);
Set_Mechanism (Formal, Default_Mechanism);
return Formal;
end Make_Op_Formal;
-- Start of processing for New_Concatenation_Op
begin
Op := Make_Defining_Operator_Symbol (Loc, Name_Op_Concat);
Set_Ekind (Op, E_Operator);
Set_Scope (Op, Current_Scope);
Set_Etype (Op, Typ);
Set_Homonym (Op, Get_Name_Entity_Id (Name_Op_Concat));
Set_Is_Immediately_Visible (Op);
Set_Is_Intrinsic_Subprogram (Op);
Set_Has_Completion (Op);
Append_Entity (Op, Current_Scope);
Set_Name_Entity_Id (Name_Op_Concat, Op);
Append_Entity (Make_Op_Formal (Typ, Op), Op);
Append_Entity (Make_Op_Formal (Typ, Op), Op);
end New_Concatenation_Op;
-------------------------------------------
-- Ordinary_Fixed_Point_Type_Declaration --
-------------------------------------------
procedure Ordinary_Fixed_Point_Type_Declaration
(T : Entity_Id;
Def : Node_Id)
is
Loc : constant Source_Ptr := Sloc (Def);
Delta_Expr : constant Node_Id := Delta_Expression (Def);
RRS : constant Node_Id := Real_Range_Specification (Def);
Implicit_Base : Entity_Id;
Delta_Val : Ureal;
Small_Val : Ureal;
Low_Val : Ureal;
High_Val : Ureal;
begin
Check_Restriction (No_Fixed_Point, Def);
-- Create implicit base type
Implicit_Base :=
Create_Itype (E_Ordinary_Fixed_Point_Type, Parent (Def), T, 'B');
Set_Etype (Implicit_Base, Implicit_Base);
-- Analyze and process delta expression
Analyze_And_Resolve (Delta_Expr, Any_Real);
Check_Delta_Expression (Delta_Expr);
Delta_Val := Expr_Value_R (Delta_Expr);
Set_Delta_Value (Implicit_Base, Delta_Val);
-- Compute default small from given delta, which is the largest power
-- of two that does not exceed the given delta value.
declare
Tmp : Ureal;
Scale : Int;
begin
Tmp := Ureal_1;
Scale := 0;
if Delta_Val < Ureal_1 then
while Delta_Val < Tmp loop
Tmp := Tmp / Ureal_2;
Scale := Scale + 1;
end loop;
else
loop
Tmp := Tmp * Ureal_2;
exit when Tmp > Delta_Val;
Scale := Scale - 1;
end loop;
end if;
Small_Val := UR_From_Components (Uint_1, UI_From_Int (Scale), 2);
end;
Set_Small_Value (Implicit_Base, Small_Val);
-- If no range was given, set a dummy range
if RRS <= Empty_Or_Error then
Low_Val := -Small_Val;
High_Val := Small_Val;
-- Otherwise analyze and process given range
else
declare
Low : constant Node_Id := Low_Bound (RRS);
High : constant Node_Id := High_Bound (RRS);
begin
Analyze_And_Resolve (Low, Any_Real);
Analyze_And_Resolve (High, Any_Real);
Check_Real_Bound (Low);
Check_Real_Bound (High);
-- Obtain and set the range
Low_Val := Expr_Value_R (Low);
High_Val := Expr_Value_R (High);
if Low_Val > High_Val then
Error_Msg_NE ("?fixed point type& has null range", Def, T);
end if;
end;
end if;
-- The range for both the implicit base and the declared first subtype
-- cannot be set yet, so we use the special routine Set_Fixed_Range to
-- set a temporary range in place. Note that the bounds of the base
-- type will be widened to be symmetrical and to fill the available
-- bits when the type is frozen.
-- We could do this with all discrete types, and probably should, but
-- we absolutely have to do it for fixed-point, since the end-points
-- of the range and the size are determined by the small value, which
-- could be reset before the freeze point.
Set_Fixed_Range (Implicit_Base, Loc, Low_Val, High_Val);
Set_Fixed_Range (T, Loc, Low_Val, High_Val);
Init_Size_Align (Implicit_Base);
-- Complete definition of first subtype
Set_Ekind (T, E_Ordinary_Fixed_Point_Subtype);
Set_Etype (T, Implicit_Base);
Init_Size_Align (T);
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Small_Value (T, Small_Val);
Set_Delta_Value (T, Delta_Val);
Set_Is_Constrained (T);
end Ordinary_Fixed_Point_Type_Declaration;
----------------------------------------
-- Prepare_Private_Subtype_Completion --
----------------------------------------
procedure Prepare_Private_Subtype_Completion
(Id : Entity_Id;
Related_Nod : Node_Id)
is
Id_B : constant Entity_Id := Base_Type (Id);
Full_B : constant Entity_Id := Full_View (Id_B);
Full : Entity_Id;
begin
if Present (Full_B) then
-- The Base_Type is already completed, we can complete the subtype
-- now. We have to create a new entity with the same name, Thus we
-- can't use Create_Itype.
-- This is messy, should be fixed ???
Full := Make_Defining_Identifier (Sloc (Id), Chars (Id));
Set_Is_Itype (Full);
Set_Associated_Node_For_Itype (Full, Related_Nod);
Complete_Private_Subtype (Id, Full, Full_B, Related_Nod);
end if;
-- The parent subtype may be private, but the base might not, in some
-- nested instances. In that case, the subtype does not need to be
-- exchanged. It would still be nice to make private subtypes and their
-- bases consistent at all times ???
if Is_Private_Type (Id_B) then
Append_Elmt (Id, Private_Dependents (Id_B));
end if;
end Prepare_Private_Subtype_Completion;
---------------------------
-- Process_Discriminants --
---------------------------
procedure Process_Discriminants
(N : Node_Id;
Prev : Entity_Id := Empty)
is
Elist : constant Elist_Id := New_Elmt_List;
Id : Node_Id;
Discr : Node_Id;
Discr_Number : Uint;
Discr_Type : Entity_Id;
Default_Present : Boolean := False;
Default_Not_Present : Boolean := False;
begin
-- A composite type other than an array type can have discriminants.
-- Discriminants of non-limited types must have a discrete type.
-- On entry, the current scope is the composite type.
-- The discriminants are initially entered into the scope of the type
-- via Enter_Name with the default Ekind of E_Void to prevent premature
-- use, as explained at the end of this procedure.
Discr := First (Discriminant_Specifications (N));
while Present (Discr) loop
Enter_Name (Defining_Identifier (Discr));
-- For navigation purposes we add a reference to the discriminant
-- in the entity for the type. If the current declaration is a
-- completion, place references on the partial view. Otherwise the
-- type is the current scope.
if Present (Prev) then
-- The references go on the partial view, if present. If the
-- partial view has discriminants, the references have been
-- generated already.
if not Has_Discriminants (Prev) then
Generate_Reference (Prev, Defining_Identifier (Discr), 'd');
end if;
else
Generate_Reference
(Current_Scope, Defining_Identifier (Discr), 'd');
end if;
if Nkind (Discriminant_Type (Discr)) = N_Access_Definition then
Discr_Type := Access_Definition (Discr, Discriminant_Type (Discr));
-- Ada 2005 (AI-230): Access discriminants are now allowed for
-- nonlimited types, and are treated like other components of
-- anonymous access types in terms of accessibility.
if not Is_Concurrent_Type (Current_Scope)
and then not Is_Concurrent_Record_Type (Current_Scope)
and then not Is_Limited_Record (Current_Scope)
and then Ekind (Current_Scope) /= E_Limited_Private_Type
then
Set_Is_Local_Anonymous_Access (Discr_Type);
end if;
-- Ada 2005 (AI-254)
if Present (Access_To_Subprogram_Definition
(Discriminant_Type (Discr)))
and then Protected_Present (Access_To_Subprogram_Definition
(Discriminant_Type (Discr)))
then
Discr_Type :=
Replace_Anonymous_Access_To_Protected_Subprogram
(Discr, Discr_Type);
end if;
else
Find_Type (Discriminant_Type (Discr));
Discr_Type := Etype (Discriminant_Type (Discr));
if Error_Posted (Discriminant_Type (Discr)) then
Discr_Type := Any_Type;
end if;
end if;
if Is_Access_Type (Discr_Type) then
-- Ada 2005 (AI-230): Access discriminant allowed in non-limited
-- record types
if Ada_Version < Ada_05 then
Check_Access_Discriminant_Requires_Limited
(Discr, Discriminant_Type (Discr));
end if;
if Ada_Version = Ada_83 and then Comes_From_Source (Discr) then
Error_Msg_N
("(Ada 83) access discriminant not allowed", Discr);
end if;
elsif not Is_Discrete_Type (Discr_Type) then
Error_Msg_N ("discriminants must have a discrete or access type",
Discriminant_Type (Discr));
end if;
Set_Etype (Defining_Identifier (Discr), Discr_Type);
-- If a discriminant specification includes the assignment compound
-- delimiter followed by an expression, the expression is the default
-- expression of the discriminant; the default expression must be of
-- the type of the discriminant. (RM 3.7.1) Since this expression is
-- a default expression, we do the special preanalysis, since this
-- expression does not freeze (see "Handling of Default and Per-
-- Object Expressions" in spec of package Sem).
if Present (Expression (Discr)) then
Analyze_Per_Use_Expression (Expression (Discr), Discr_Type);
if Nkind (N) = N_Formal_Type_Declaration then
Error_Msg_N
("discriminant defaults not allowed for formal type",
Expression (Discr));
-- Tagged types cannot have defaulted discriminants, but a
-- non-tagged private type with defaulted discriminants
-- can have a tagged completion.
elsif Is_Tagged_Type (Current_Scope)
and then Comes_From_Source (N)
then
Error_Msg_N
("discriminants of tagged type cannot have defaults",
Expression (Discr));
else
Default_Present := True;
Append_Elmt (Expression (Discr), Elist);
-- Tag the defining identifiers for the discriminants with
-- their corresponding default expressions from the tree.
Set_Discriminant_Default_Value
(Defining_Identifier (Discr), Expression (Discr));
end if;
else
Default_Not_Present := True;
end if;
-- Ada 2005 (AI-231): Create an Itype that is a duplicate of
-- Discr_Type but with the null-exclusion attribute
if Ada_Version >= Ada_05 then
-- Ada 2005 (AI-231): Static checks
if Can_Never_Be_Null (Discr_Type) then
Null_Exclusion_Static_Checks (Discr);
elsif Is_Access_Type (Discr_Type)
and then Null_Exclusion_Present (Discr)
-- No need to check itypes because in their case this check
-- was done at their point of creation
and then not Is_Itype (Discr_Type)
then
if Can_Never_Be_Null (Discr_Type) then
Error_Msg_N
("(Ada 2005) already a null-excluding type", Discr);
end if;
Set_Etype (Defining_Identifier (Discr),
Create_Null_Excluding_Itype
(T => Discr_Type,
Related_Nod => Discr));
end if;
end if;
Next (Discr);
end loop;
-- An element list consisting of the default expressions of the
-- discriminants is constructed in the above loop and used to set
-- the Discriminant_Constraint attribute for the type. If an object
-- is declared of this (record or task) type without any explicit
-- discriminant constraint given, this element list will form the
-- actual parameters for the corresponding initialization procedure
-- for the type.
Set_Discriminant_Constraint (Current_Scope, Elist);
Set_Stored_Constraint (Current_Scope, No_Elist);
-- Default expressions must be provided either for all or for none
-- of the discriminants of a discriminant part. (RM 3.7.1)
if Default_Present and then Default_Not_Present then
Error_Msg_N
("incomplete specification of defaults for discriminants", N);
end if;
-- The use of the name of a discriminant is not allowed in default
-- expressions of a discriminant part if the specification of the
-- discriminant is itself given in the discriminant part. (RM 3.7.1)
-- To detect this, the discriminant names are entered initially with an
-- Ekind of E_Void (which is the default Ekind given by Enter_Name). Any
-- attempt to use a void entity (for example in an expression that is
-- type-checked) produces the error message: premature usage. Now after
-- completing the semantic analysis of the discriminant part, we can set
-- the Ekind of all the discriminants appropriately.
Discr := First (Discriminant_Specifications (N));
Discr_Number := Uint_1;
while Present (Discr) loop
Id := Defining_Identifier (Discr);
Set_Ekind (Id, E_Discriminant);
Init_Component_Location (Id);
Init_Esize (Id);
Set_Discriminant_Number (Id, Discr_Number);
-- Make sure this is always set, even in illegal programs
Set_Corresponding_Discriminant (Id, Empty);
-- Initialize the Original_Record_Component to the entity itself.
-- Inherit_Components will propagate the right value to
-- discriminants in derived record types.
Set_Original_Record_Component (Id, Id);
-- Create the discriminal for the discriminant
Build_Discriminal (Id);
Next (Discr);
Discr_Number := Discr_Number + 1;
end loop;
Set_Has_Discriminants (Current_Scope);
end Process_Discriminants;
-----------------------
-- Process_Full_View --
-----------------------
procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id) is
Priv_Parent : Entity_Id;
Full_Parent : Entity_Id;
Full_Indic : Node_Id;
procedure Collect_Implemented_Interfaces
(Typ : Entity_Id;
Ifaces : Elist_Id);
-- Ada 2005: Gather all the interfaces that Typ directly or
-- inherently implements. Duplicate entries are not added to
-- the list Ifaces.
function Contain_Interface
(Iface : Entity_Id;
Ifaces : Elist_Id) return Boolean;
-- Ada 2005: Determine whether Iface is present in the list Ifaces
function Find_Hidden_Interface
(Src : Elist_Id;
Dest : Elist_Id) return Entity_Id;
-- Ada 2005: Determine whether the interfaces in list Src are all
-- present in the list Dest. Return the first differing interface,
-- or Empty otherwise.
------------------------------------
-- Collect_Implemented_Interfaces --
------------------------------------
procedure Collect_Implemented_Interfaces
(Typ : Entity_Id;
Ifaces : Elist_Id)
is
Iface : Entity_Id;
Iface_Elmt : Elmt_Id;
begin
-- Abstract interfaces are only associated with tagged record types
if not Is_Tagged_Type (Typ)
or else not Is_Record_Type (Typ)
then
return;
end if;
-- Implementations of the form:
-- type Typ is new Iface ...
if Is_Interface (Etype (Typ))
and then not Contain_Interface (Etype (Typ), Ifaces)
then
Append_Elmt (Etype (Typ), Ifaces);
end if;
-- Implementations of the form:
-- type Typ is ... and Iface ...
if Present (Abstract_Interfaces (Typ)) then
Iface_Elmt := First_Elmt (Abstract_Interfaces (Typ));
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
pragma Assert (Is_Interface (Iface));
if not Contain_Interface (Iface, Ifaces) then
Append_Elmt (Iface, Ifaces);
Collect_Implemented_Interfaces (Iface, Ifaces);
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
-- Implementations of the form:
-- type Typ is new Parent_Typ and ...
if Ekind (Typ) = E_Record_Type
and then Present (Parent_Subtype (Typ))
then
Collect_Implemented_Interfaces (Parent_Subtype (Typ), Ifaces);
-- Implementations of the form:
-- type Typ is ... with private;
elsif Ekind (Typ) = E_Record_Type_With_Private
and then Present (Full_View (Typ))
and then Etype (Typ) /= Full_View (Typ)
and then Etype (Typ) /= Typ
then
Collect_Implemented_Interfaces (Etype (Typ), Ifaces);
end if;
end Collect_Implemented_Interfaces;
-----------------------
-- Contain_Interface --
-----------------------
function Contain_Interface
(Iface : Entity_Id;
Ifaces : Elist_Id) return Boolean
is
Iface_Elmt : Elmt_Id;
begin
if Present (Ifaces) then
Iface_Elmt := First_Elmt (Ifaces);
while Present (Iface_Elmt) loop
if Node (Iface_Elmt) = Iface then
return True;
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
return False;
end Contain_Interface;
---------------------------
-- Find_Hidden_Interface --
---------------------------
function Find_Hidden_Interface
(Src : Elist_Id;
Dest : Elist_Id) return Entity_Id
is
Iface : Entity_Id;
Iface_Elmt : Elmt_Id;
begin
if Present (Src) and then Present (Dest) then
Iface_Elmt := First_Elmt (Src);
while Present (Iface_Elmt) loop
Iface := Node (Iface_Elmt);
if not Contain_Interface (Iface, Dest) then
return Iface;
end if;
Next_Elmt (Iface_Elmt);
end loop;
end if;
return Empty;
end Find_Hidden_Interface;
-- Start of processing for Process_Full_View
begin
-- First some sanity checks that must be done after semantic
-- decoration of the full view and thus cannot be placed with other
-- similar checks in Find_Type_Name
if not Is_Limited_Type (Priv_T)
and then (Is_Limited_Type (Full_T)
or else Is_Limited_Composite (Full_T))
then
Error_Msg_N
("completion of nonlimited type cannot be limited", Full_T);
Explain_Limited_Type (Full_T, Full_T);
elsif Is_Abstract (Full_T) and then not Is_Abstract (Priv_T) then
Error_Msg_N
("completion of nonabstract type cannot be abstract", Full_T);
elsif Is_Tagged_Type (Priv_T)
and then Is_Limited_Type (Priv_T)
and then not Is_Limited_Type (Full_T)
then
-- GNAT allow its own definition of Limited_Controlled to disobey
-- this rule in order in ease the implementation. The next test is
-- safe because Root_Controlled is defined in a private system child
if Etype (Full_T) = Full_View (RTE (RE_Root_Controlled)) then
Set_Is_Limited_Composite (Full_T);
else
Error_Msg_N
("completion of limited tagged type must be limited", Full_T);
end if;
elsif Is_Generic_Type (Priv_T) then
Error_Msg_N ("generic type cannot have a completion", Full_T);
end if;
if Ada_Version >= Ada_05
and then Is_Tagged_Type (Priv_T)
and then Is_Tagged_Type (Full_T)
then
declare
Iface : Entity_Id;
Priv_T_Ifaces : constant Elist_Id := New_Elmt_List;
Full_T_Ifaces : constant Elist_Id := New_Elmt_List;
begin
Collect_Implemented_Interfaces (Priv_T, Priv_T_Ifaces);
Collect_Implemented_Interfaces (Full_T, Full_T_Ifaces);
-- Ada 2005 (AI-251): The partial view shall be a descendant of
-- an interface type if and only if the full type is descendant
-- of the interface type (AARM 7.3 (7.3/2).
Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
if Present (Iface) then
Error_Msg_NE ("interface & not implemented by full type " &
"('R'M'-2005 7.3 (7.3/2))", Priv_T, Iface);
end if;
Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
if Present (Iface) then
Error_Msg_NE ("interface & not implemented by partial view " &
"('R'M'-2005 7.3 (7.3/2))", Full_T, Iface);
end if;
end;
end if;
if Is_Tagged_Type (Priv_T)
and then Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
and then Is_Derived_Type (Full_T)
then
Priv_Parent := Etype (Priv_T);
-- The full view of a private extension may have been transformed
-- into an unconstrained derived type declaration and a subtype
-- declaration (see build_derived_record_type for details).
if Nkind (N) = N_Subtype_Declaration then
Full_Indic := Subtype_Indication (N);
Full_Parent := Etype (Base_Type (Full_T));
else
Full_Indic := Subtype_Indication (Type_Definition (N));
Full_Parent := Etype (Full_T);
end if;
-- Check that the parent type of the full type is a descendant of
-- the ancestor subtype given in the private extension. If either
-- entity has an Etype equal to Any_Type then we had some previous
-- error situation [7.3(8)].
if Priv_Parent = Any_Type or else Full_Parent = Any_Type then
return;
-- Ada 2005 (AI-251): Interfaces in the full-typ can be given in
-- any order. Therefore we don't have to check that its parent must
-- be a descendant of the parent of the private type declaration.
elsif Is_Interface (Priv_Parent)
and then Is_Interface (Full_Parent)
then
null;
-- Ada 2005 (AI-251): If the parent of the private type declaration
-- is an interface there is no need to check that it is an ancestor
-- of the associated full type declaration. The required tests for
-- this case case are performed by Build_Derived_Record_Type.
elsif not Is_Interface (Base_Type (Priv_Parent))
and then not Is_Ancestor (Base_Type (Priv_Parent), Full_Parent)
then
Error_Msg_N
("parent of full type must descend from parent"
& " of private extension", Full_Indic);
-- Check the rules of 7.3(10): if the private extension inherits
-- known discriminants, then the full type must also inherit those
-- discriminants from the same (ancestor) type, and the parent
-- subtype of the full type must be constrained if and only if
-- the ancestor subtype of the private extension is constrained.
elsif No (Discriminant_Specifications (Parent (Priv_T)))
and then not Has_Unknown_Discriminants (Priv_T)
and then Has_Discriminants (Base_Type (Priv_Parent))
then
declare
Priv_Indic : constant Node_Id :=
Subtype_Indication (Parent (Priv_T));
Priv_Constr : constant Boolean :=
Is_Constrained (Priv_Parent)
or else
Nkind (Priv_Indic) = N_Subtype_Indication
or else Is_Constrained (Entity (Priv_Indic));
Full_Constr : constant Boolean :=
Is_Constrained (Full_Parent)
or else
Nkind (Full_Indic) = N_Subtype_Indication
or else Is_Constrained (Entity (Full_Indic));
Priv_Discr : Entity_Id;
Full_Discr : Entity_Id;
begin
Priv_Discr := First_Discriminant (Priv_Parent);
Full_Discr := First_Discriminant (Full_Parent);
while Present (Priv_Discr) and then Present (Full_Discr) loop
if Original_Record_Component (Priv_Discr) =
Original_Record_Component (Full_Discr)
or else
Corresponding_Discriminant (Priv_Discr) =
Corresponding_Discriminant (Full_Discr)
then
null;
else
exit;
end if;
Next_Discriminant (Priv_Discr);
Next_Discriminant (Full_Discr);
end loop;
if Present (Priv_Discr) or else Present (Full_Discr) then
Error_Msg_N
("full view must inherit discriminants of the parent type"
& " used in the private extension", Full_Indic);
elsif Priv_Constr and then not Full_Constr then
Error_Msg_N
("parent subtype of full type must be constrained",
Full_Indic);
elsif Full_Constr and then not Priv_Constr then
Error_Msg_N
("parent subtype of full type must be unconstrained",
Full_Indic);
end if;
end;
-- Check the rules of 7.3(12): if a partial view has neither known
-- or unknown discriminants, then the full type declaration shall
-- define a definite subtype.
elsif not Has_Unknown_Discriminants (Priv_T)
and then not Has_Discriminants (Priv_T)
and then not Is_Constrained (Full_T)
then
Error_Msg_N
("full view must define a constrained type if partial view"
& " has no discriminants", Full_T);
end if;
-- ??????? Do we implement the following properly ?????
-- If the ancestor subtype of a private extension has constrained
-- discriminants, then the parent subtype of the full view shall
-- impose a statically matching constraint on those discriminants
-- [7.3(13)].
else
-- For untagged types, verify that a type without discriminants
-- is not completed with an unconstrained type.
if not Is_Indefinite_Subtype (Priv_T)
and then Is_Indefinite_Subtype (Full_T)
then
Error_Msg_N ("full view of type must be definite subtype", Full_T);
end if;
end if;
-- AI-419: verify that the use of "limited" is consistent
declare
Orig_Decl : constant Node_Id := Original_Node (N);
begin
if Nkind (Parent (Priv_T)) = N_Private_Extension_Declaration
and then not Limited_Present (Parent (Priv_T))
and then Nkind (Orig_Decl) = N_Full_Type_Declaration
and then Nkind
(Type_Definition (Orig_Decl)) = N_Derived_Type_Definition
and then Limited_Present (Type_Definition (Orig_Decl))
then
Error_Msg_N
("full view of non-limited extension cannot be limited", N);
end if;
end;
-- Ada 2005 AI-363: if the full view has discriminants with
-- defaults, it is illegal to declare constrained access subtypes
-- whose designated type is the current type. This allows objects
-- of the type that are declared in the heap to be unconstrained.
if not Has_Unknown_Discriminants (Priv_T)
and then not Has_Discriminants (Priv_T)
and then Has_Discriminants (Full_T)
and then
Present
(Discriminant_Default_Value (First_Discriminant (Full_T)))
then
Set_Has_Constrained_Partial_View (Full_T);
Set_Has_Constrained_Partial_View (Priv_T);
end if;
-- Create a full declaration for all its subtypes recorded in
-- Private_Dependents and swap them similarly to the base type. These
-- are subtypes that have been define before the full declaration of
-- the private type. We also swap the entry in Private_Dependents list
-- so we can properly restore the private view on exit from the scope.
declare
Priv_Elmt : Elmt_Id;
Priv : Entity_Id;
Full : Entity_Id;
begin
Priv_Elmt := First_Elmt (Private_Dependents (Priv_T));
while Present (Priv_Elmt) loop
Priv := Node (Priv_Elmt);
if Ekind (Priv) = E_Private_Subtype
or else Ekind (Priv) = E_Limited_Private_Subtype
or else Ekind (Priv) = E_Record_Subtype_With_Private
then
Full := Make_Defining_Identifier (Sloc (Priv), Chars (Priv));
Set_Is_Itype (Full);
Set_Parent (Full, Parent (Priv));
Set_Associated_Node_For_Itype (Full, N);
-- Now we need to complete the private subtype, but since the
-- base type has already been swapped, we must also swap the
-- subtypes (and thus, reverse the arguments in the call to
-- Complete_Private_Subtype).
Copy_And_Swap (Priv, Full);
Complete_Private_Subtype (Full, Priv, Full_T, N);
Replace_Elmt (Priv_Elmt, Full);
end if;
Next_Elmt (Priv_Elmt);
end loop;
end;
-- If the private view was tagged, copy the new Primitive
-- operations from the private view to the full view.
if Is_Tagged_Type (Full_T) then
declare
Priv_List : Elist_Id;
Full_List : constant Elist_Id := Primitive_Operations (Full_T);
P1, P2 : Elmt_Id;
Prim : Entity_Id;
D_Type : Entity_Id;
begin
if Is_Tagged_Type (Priv_T) then
Priv_List := Primitive_Operations (Priv_T);
P1 := First_Elmt (Priv_List);
while Present (P1) loop
Prim := Node (P1);
-- Transfer explicit primitives, not those inherited from
-- parent of partial view, which will be re-inherited on
-- the full view.
if Comes_From_Source (Prim) then
P2 := First_Elmt (Full_List);
while Present (P2) and then Node (P2) /= Prim loop
Next_Elmt (P2);
end loop;
-- If not found, that is a new one
if No (P2) then
Append_Elmt (Prim, Full_List);
end if;
end if;
Next_Elmt (P1);
end loop;
else
-- In this case the partial view is untagged, so here we
-- locate all of the earlier primitives that need to be
-- treated as dispatching (those that appear between the two
-- views). Note that these additional operations must all be
-- new operations (any earlier operations that override
-- inherited operations of the full view will already have
-- been inserted in the primitives list and marked as
-- dispatching by Check_Operation_From_Private_View. Note that
-- implicit "/=" operators are excluded from being added to
-- the primitives list since they shouldn't be treated as
-- dispatching (tagged "/=" is handled specially).
Prim := Next_Entity (Full_T);
while Present (Prim) and then Prim /= Priv_T loop
if Ekind (Prim) = E_Procedure
or else
Ekind (Prim) = E_Function
then
D_Type := Find_Dispatching_Type (Prim);
if D_Type = Full_T
and then (Chars (Prim) /= Name_Op_Ne
or else Comes_From_Source (Prim))
then
Check_Controlling_Formals (Full_T, Prim);
if not Is_Dispatching_Operation (Prim) then
Append_Elmt (Prim, Full_List);
Set_Is_Dispatching_Operation (Prim, True);
Set_DT_Position (Prim, No_Uint);
end if;
elsif Is_Dispatching_Operation (Prim)
and then D_Type /= Full_T
then
-- Verify that it is not otherwise controlled by
-- a formal or a return value of type T.
Check_Controlling_Formals (D_Type, Prim);
end if;
end if;
Next_Entity (Prim);
end loop;
end if;
-- For the tagged case, the two views can share the same
-- Primitive Operation list and the same class wide type.
-- Update attributes of the class-wide type which depend on
-- the full declaration.
if Is_Tagged_Type (Priv_T) then
Set_Primitive_Operations (Priv_T, Full_List);
Set_Class_Wide_Type
(Base_Type (Full_T), Class_Wide_Type (Priv_T));
-- Any other attributes should be propagated to C_W ???
Set_Has_Task (Class_Wide_Type (Priv_T), Has_Task (Full_T));
end if;
end;
end if;
end Process_Full_View;
-----------------------------------
-- Process_Incomplete_Dependents --
-----------------------------------
procedure Process_Incomplete_Dependents
(N : Node_Id;
Full_T : Entity_Id;
Inc_T : Entity_Id)
is
Inc_Elmt : Elmt_Id;
Priv_Dep : Entity_Id;
New_Subt : Entity_Id;
Disc_Constraint : Elist_Id;
begin
if No (Private_Dependents (Inc_T)) then
return;
end if;
-- Itypes that may be generated by the completion of an incomplete
-- subtype are not used by the back-end and not attached to the tree.
-- They are created only for constraint-checking purposes.
Inc_Elmt := First_Elmt (Private_Dependents (Inc_T));
while Present (Inc_Elmt) loop
Priv_Dep := Node (Inc_Elmt);
if Ekind (Priv_Dep) = E_Subprogram_Type then
-- An Access_To_Subprogram type may have a return type or a
-- parameter type that is incomplete. Replace with the full view.
if Etype (Priv_Dep) = Inc_T then
Set_Etype (Priv_Dep, Full_T);
end if;
declare
Formal : Entity_Id;
begin
Formal := First_Formal (Priv_Dep);
while Present (Formal) loop
if Etype (Formal) = Inc_T then
Set_Etype (Formal, Full_T);
end if;
Next_Formal (Formal);
end loop;
end;
elsif Is_Overloadable (Priv_Dep) then
-- A protected operation is never dispatching: only its
-- wrapper operation (which has convention Ada) is.
if Is_Tagged_Type (Full_T)
and then Convention (Priv_Dep) /= Convention_Protected
then
-- Subprogram has an access parameter whose designated type
-- was incomplete. Reexamine declaration now, because it may
-- be a primitive operation of the full type.
Check_Operation_From_Incomplete_Type (Priv_Dep, Inc_T);
Set_Is_Dispatching_Operation (Priv_Dep);
Check_Controlling_Formals (Full_T, Priv_Dep);
end if;
elsif Ekind (Priv_Dep) = E_Subprogram_Body then
-- Can happen during processing of a body before the completion
-- of a TA type. Ignore, because spec is also on dependent list.
return;
-- Dependent is a subtype
else
-- We build a new subtype indication using the full view of the
-- incomplete parent. The discriminant constraints have been
-- elaborated already at the point of the subtype declaration.
New_Subt := Create_Itype (E_Void, N);
if Has_Discriminants (Full_T) then
Disc_Constraint := Discriminant_Constraint (Priv_Dep);
else
Disc_Constraint := No_Elist;
end if;
Build_Discriminated_Subtype (Full_T, New_Subt, Disc_Constraint, N);
Set_Full_View (Priv_Dep, New_Subt);
end if;
Next_Elmt (Inc_Elmt);
end loop;
end Process_Incomplete_Dependents;
--------------------------------
-- Process_Range_Expr_In_Decl --
--------------------------------
procedure Process_Range_Expr_In_Decl
(R : Node_Id;
T : Entity_Id;
Check_List : List_Id := Empty_List;
R_Check_Off : Boolean := False)
is
Lo, Hi : Node_Id;
R_Checks : Check_Result;
Type_Decl : Node_Id;
Def_Id : Entity_Id;
begin
Analyze_And_Resolve (R, Base_Type (T));
if Nkind (R) = N_Range then
Lo := Low_Bound (R);
Hi := High_Bound (R);
-- If there were errors in the declaration, try and patch up some
-- common mistakes in the bounds. The cases handled are literals
-- which are Integer where the expected type is Real and vice versa.
-- These corrections allow the compilation process to proceed further
-- along since some basic assumptions of the format of the bounds
-- are guaranteed.
if Etype (R) = Any_Type then
if Nkind (Lo) = N_Integer_Literal and then Is_Real_Type (T) then
Rewrite (Lo,
Make_Real_Literal (Sloc (Lo), UR_From_Uint (Intval (Lo))));
elsif Nkind (Hi) = N_Integer_Literal and then Is_Real_Type (T) then
Rewrite (Hi,
Make_Real_Literal (Sloc (Hi), UR_From_Uint (Intval (Hi))));
elsif Nkind (Lo) = N_Real_Literal and then Is_Integer_Type (T) then
Rewrite (Lo,
Make_Integer_Literal (Sloc (Lo), UR_To_Uint (Realval (Lo))));
elsif Nkind (Hi) = N_Real_Literal and then Is_Integer_Type (T) then
Rewrite (Hi,
Make_Integer_Literal (Sloc (Hi), UR_To_Uint (Realval (Hi))));
end if;
Set_Etype (Lo, T);
Set_Etype (Hi, T);
end if;
-- If the bounds of the range have been mistakenly given as string
-- literals (perhaps in place of character literals), then an error
-- has already been reported, but we rewrite the string literal as a
-- bound of the range's type to avoid blowups in later processing
-- that looks at static values.
if Nkind (Lo) = N_String_Literal then
Rewrite (Lo,
Make_Attribute_Reference (Sloc (Lo),
Attribute_Name => Name_First,
Prefix => New_Reference_To (T, Sloc (Lo))));
Analyze_And_Resolve (Lo);
end if;
if Nkind (Hi) = N_String_Literal then
Rewrite (Hi,
Make_Attribute_Reference (Sloc (Hi),
Attribute_Name => Name_First,
Prefix => New_Reference_To (T, Sloc (Hi))));
Analyze_And_Resolve (Hi);
end if;
-- If bounds aren't scalar at this point then exit, avoiding
-- problems with further processing of the range in this procedure.
if not Is_Scalar_Type (Etype (Lo)) then
return;
end if;
-- Resolve (actually Sem_Eval) has checked that the bounds are in
-- then range of the base type. Here we check whether the bounds
-- are in the range of the subtype itself. Note that if the bounds
-- represent the null range the Constraint_Error exception should
-- not be raised.
-- ??? The following code should be cleaned up as follows
-- 1. The Is_Null_Range (Lo, Hi) test should disappear since it
-- is done in the call to Range_Check (R, T); below
-- 2. The use of R_Check_Off should be investigated and possibly
-- removed, this would clean up things a bit.
if Is_Null_Range (Lo, Hi) then
null;
else
-- Capture values of bounds and generate temporaries for them
-- if needed, before applying checks, since checks may cause
-- duplication of the expression without forcing evaluation.
if Expander_Active then
Force_Evaluation (Lo);
Force_Evaluation (Hi);
end if;
-- We use a flag here instead of suppressing checks on the
-- type because the type we check against isn't necessarily
-- the place where we put the check.
if not R_Check_Off then
R_Checks := Range_Check (R, T);
-- Look up tree to find an appropriate insertion point.
-- This seems really junk code, and very brittle, couldn't
-- we just use an insert actions call of some kind ???
Type_Decl := Parent (R);
while Present (Type_Decl) and then not
(Nkind (Type_Decl) = N_Full_Type_Declaration
or else
Nkind (Type_Decl) = N_Subtype_Declaration
or else
Nkind (Type_Decl) = N_Loop_Statement
or else
Nkind (Type_Decl) = N_Task_Type_Declaration
or else
Nkind (Type_Decl) = N_Single_Task_Declaration
or else
Nkind (Type_Decl) = N_Protected_Type_Declaration
or else
Nkind (Type_Decl) = N_Single_Protected_Declaration)
loop
Type_Decl := Parent (Type_Decl);
end loop;
-- Why would Type_Decl not be present??? Without this test,
-- short regression tests fail.
if Present (Type_Decl) then
-- Case of loop statement (more comments ???)
if Nkind (Type_Decl) = N_Loop_Statement then
declare
Indic : Node_Id;
begin
Indic := Parent (R);
while Present (Indic) and then not
(Nkind (Indic) = N_Subtype_Indication)
loop
Indic := Parent (Indic);
end loop;
if Present (Indic) then
Def_Id := Etype (Subtype_Mark (Indic));
Insert_Range_Checks
(R_Checks,
Type_Decl,
Def_Id,
Sloc (Type_Decl),
R,
Do_Before => True);
end if;
end;
-- All other cases (more comments ???)
else
Def_Id := Defining_Identifier (Type_Decl);
if (Ekind (Def_Id) = E_Record_Type
and then Depends_On_Discriminant (R))
or else
(Ekind (Def_Id) = E_Protected_Type
and then Has_Discriminants (Def_Id))
then
Append_Range_Checks
(R_Checks, Check_List, Def_Id, Sloc (Type_Decl), R);
else
Insert_Range_Checks
(R_Checks, Type_Decl, Def_Id, Sloc (Type_Decl), R);
end if;
end if;
end if;
end if;
end if;
elsif Expander_Active then
Get_Index_Bounds (R, Lo, Hi);
Force_Evaluation (Lo);
Force_Evaluation (Hi);
end if;
end Process_Range_Expr_In_Decl;
--------------------------------------
-- Process_Real_Range_Specification --
--------------------------------------
procedure Process_Real_Range_Specification (Def : Node_Id) is
Spec : constant Node_Id := Real_Range_Specification (Def);
Lo : Node_Id;
Hi : Node_Id;
Err : Boolean := False;
procedure Analyze_Bound (N : Node_Id);
-- Analyze and check one bound
-------------------
-- Analyze_Bound --
-------------------
procedure Analyze_Bound (N : Node_Id) is
begin
Analyze_And_Resolve (N, Any_Real);
if not Is_OK_Static_Expression (N) then
Flag_Non_Static_Expr
("bound in real type definition is not static!", N);
Err := True;
end if;
end Analyze_Bound;
-- Start of processing for Process_Real_Range_Specification
begin
if Present (Spec) then
Lo := Low_Bound (Spec);
Hi := High_Bound (Spec);
Analyze_Bound (Lo);
Analyze_Bound (Hi);
-- If error, clear away junk range specification
if Err then
Set_Real_Range_Specification (Def, Empty);
end if;
end if;
end Process_Real_Range_Specification;
---------------------
-- Process_Subtype --
---------------------
function Process_Subtype
(S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix : Character := ' ') return Entity_Id
is
P : Node_Id;
Def_Id : Entity_Id;
Error_Node : Node_Id;
Full_View_Id : Entity_Id;
Subtype_Mark_Id : Entity_Id;
May_Have_Null_Exclusion : Boolean;
procedure Check_Incomplete (T : Entity_Id);
-- Called to verify that an incomplete type is not used prematurely
----------------------
-- Check_Incomplete --
----------------------
procedure Check_Incomplete (T : Entity_Id) is
begin
if Ekind (Root_Type (Entity (T))) = E_Incomplete_Type then
Error_Msg_N ("invalid use of type before its full declaration", T);
end if;
end Check_Incomplete;
-- Start of processing for Process_Subtype
begin
-- Case of no constraints present
if Nkind (S) /= N_Subtype_Indication then
Find_Type (S);
Check_Incomplete (S);
P := Parent (S);
-- Ada 2005 (AI-231): Static check
if Ada_Version >= Ada_05
and then Present (P)
and then Null_Exclusion_Present (P)
and then Nkind (P) /= N_Access_To_Object_Definition
and then not Is_Access_Type (Entity (S))
then
Error_Msg_N
("(Ada 2005) the null-exclusion part requires an access type",
S);
end if;
May_Have_Null_Exclusion :=
Nkind (P) = N_Access_Definition
or else Nkind (P) = N_Access_Function_Definition
or else Nkind (P) = N_Access_Procedure_Definition
or else Nkind (P) = N_Access_To_Object_Definition
or else Nkind (P) = N_Allocator
or else Nkind (P) = N_Component_Definition
or else Nkind (P) = N_Derived_Type_Definition
or else Nkind (P) = N_Discriminant_Specification
or else Nkind (P) = N_Object_Declaration
or else Nkind (P) = N_Parameter_Specification
or else Nkind (P) = N_Subtype_Declaration;
-- Create an Itype that is a duplicate of Entity (S) but with the
-- null-exclusion attribute
if May_Have_Null_Exclusion
and then Is_Access_Type (Entity (S))
and then Null_Exclusion_Present (P)
-- No need to check the case of an access to object definition.
-- It is correct to define double not-null pointers.
-- Example:
-- type Not_Null_Int_Ptr is not null access Integer;
-- type Acc is not null access Not_Null_Int_Ptr;
and then Nkind (P) /= N_Access_To_Object_Definition
then
if Can_Never_Be_Null (Entity (S)) then
case Nkind (Related_Nod) is
when N_Full_Type_Declaration =>
if Nkind (Type_Definition (Related_Nod))
in N_Array_Type_Definition
then
Error_Node :=
Subtype_Indication
(Component_Definition
(Type_Definition (Related_Nod)));
else
Error_Node :=
Subtype_Indication (Type_Definition (Related_Nod));
end if;
when N_Subtype_Declaration =>
Error_Node := Subtype_Indication (Related_Nod);
when N_Object_Declaration =>
Error_Node := Object_Definition (Related_Nod);
when N_Component_Declaration =>
Error_Node :=
Subtype_Indication (Component_Definition (Related_Nod));
when others =>
pragma Assert (False);
Error_Node := Related_Nod;
end case;
Error_Msg_N
("(Ada 2005) already a null-excluding type", Error_Node);
end if;
Set_Etype (S,
Create_Null_Excluding_Itype
(T => Entity (S),
Related_Nod => P));
Set_Entity (S, Etype (S));
end if;
return Entity (S);
-- Case of constraint present, so that we have an N_Subtype_Indication
-- node (this node is created only if constraints are present).
else
Find_Type (Subtype_Mark (S));
if Nkind (Parent (S)) /= N_Access_To_Object_Definition
and then not
(Nkind (Parent (S)) = N_Subtype_Declaration
and then Is_Itype (Defining_Identifier (Parent (S))))
then
Check_Incomplete (Subtype_Mark (S));
end if;
P := Parent (S);
Subtype_Mark_Id := Entity (Subtype_Mark (S));
-- Explicit subtype declaration case
if Nkind (P) = N_Subtype_Declaration then
Def_Id := Defining_Identifier (P);
-- Explicit derived type definition case
elsif Nkind (P) = N_Derived_Type_Definition then
Def_Id := Defining_Identifier (Parent (P));
-- Implicit case, the Def_Id must be created as an implicit type.
-- The one exception arises in the case of concurrent types, array
-- and access types, where other subsidiary implicit types may be
-- created and must appear before the main implicit type. In these
-- cases we leave Def_Id set to Empty as a signal that Create_Itype
-- has not yet been called to create Def_Id.
else
if Is_Array_Type (Subtype_Mark_Id)
or else Is_Concurrent_Type (Subtype_Mark_Id)
or else Is_Access_Type (Subtype_Mark_Id)
then
Def_Id := Empty;
-- For the other cases, we create a new unattached Itype,
-- and set the indication to ensure it gets attached later.
else
Def_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
end if;
end if;
-- If the kind of constraint is invalid for this kind of type,
-- then give an error, and then pretend no constraint was given.
if not Is_Valid_Constraint_Kind
(Ekind (Subtype_Mark_Id), Nkind (Constraint (S)))
then
Error_Msg_N
("incorrect constraint for this kind of type", Constraint (S));
Rewrite (S, New_Copy_Tree (Subtype_Mark (S)));
-- Set Ekind of orphan itype, to prevent cascaded errors
if Present (Def_Id) then
Set_Ekind (Def_Id, Ekind (Any_Type));
end if;
-- Make recursive call, having got rid of the bogus constraint
return Process_Subtype (S, Related_Nod, Related_Id, Suffix);
end if;
-- Remaining processing depends on type
case Ekind (Subtype_Mark_Id) is
when Access_Kind =>
Constrain_Access (Def_Id, S, Related_Nod);
when Array_Kind =>
Constrain_Array (Def_Id, S, Related_Nod, Related_Id, Suffix);
when Decimal_Fixed_Point_Kind =>
Constrain_Decimal (Def_Id, S);
when Enumeration_Kind =>
Constrain_Enumeration (Def_Id, S);
when Ordinary_Fixed_Point_Kind =>
Constrain_Ordinary_Fixed (Def_Id, S);
when Float_Kind =>
Constrain_Float (Def_Id, S);
when Integer_Kind =>
Constrain_Integer (Def_Id, S);
when E_Record_Type |
E_Record_Subtype |
Class_Wide_Kind |
E_Incomplete_Type =>
Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
when Private_Kind =>
Constrain_Discriminated_Type (Def_Id, S, Related_Nod);
Set_Private_Dependents (Def_Id, New_Elmt_List);
-- In case of an invalid constraint prevent further processing
-- since the type constructed is missing expected fields.
if Etype (Def_Id) = Any_Type then
return Def_Id;
end if;
-- If the full view is that of a task with discriminants,
-- we must constrain both the concurrent type and its
-- corresponding record type. Otherwise we will just propagate
-- the constraint to the full view, if available.
if Present (Full_View (Subtype_Mark_Id))
and then Has_Discriminants (Subtype_Mark_Id)
and then Is_Concurrent_Type (Full_View (Subtype_Mark_Id))
then
Full_View_Id :=
Create_Itype (E_Void, Related_Nod, Related_Id, Suffix);
Set_Entity (Subtype_Mark (S), Full_View (Subtype_Mark_Id));
Constrain_Concurrent (Full_View_Id, S,
Related_Nod, Related_Id, Suffix);
Set_Entity (Subtype_Mark (S), Subtype_Mark_Id);
Set_Full_View (Def_Id, Full_View_Id);
else
Prepare_Private_Subtype_Completion (Def_Id, Related_Nod);
end if;
when Concurrent_Kind =>
Constrain_Concurrent (Def_Id, S,
Related_Nod, Related_Id, Suffix);
when others =>
Error_Msg_N ("invalid subtype mark in subtype indication", S);
end case;
-- Size and Convention are always inherited from the base type
Set_Size_Info (Def_Id, (Subtype_Mark_Id));
Set_Convention (Def_Id, Convention (Subtype_Mark_Id));
return Def_Id;
end if;
end Process_Subtype;
-----------------------------
-- Record_Type_Declaration --
-----------------------------
procedure Record_Type_Declaration
(T : Entity_Id;
N : Node_Id;
Prev : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Def : constant Node_Id := Type_Definition (N);
Inc_T : Entity_Id := Empty;
Is_Tagged : Boolean;
Tag_Comp : Entity_Id;
procedure Check_Anonymous_Access_Types (Comp_List : Node_Id);
-- Ada 2005 AI-382: an access component in a record declaration can
-- refer to the enclosing record, in which case it denotes the type
-- itself, and not the current instance of the type. We create an
-- anonymous access type for the component, and flag it as an access
-- to a component, so that accessibility checks are properly performed
-- on it. The declaration of the access type is placed ahead of that
-- of the record, to prevent circular order-of-elaboration issues in
-- Gigi. We create an incomplete type for the record declaration, which
-- is the designated type of the anonymous access.
procedure Make_Incomplete_Type_Declaration;
-- If the record type contains components that include an access to the
-- current record, create an incomplete type declaration for the record,
-- to be used as the designated type of the anonymous access. This is
-- done only once, and only if there is no previous partial view of the
-- type.
----------------------------------
-- Check_Anonymous_Access_Types --
----------------------------------
procedure Check_Anonymous_Access_Types (Comp_List : Node_Id) is
Anon_Access : Entity_Id;
Acc_Def : Node_Id;
Comp : Node_Id;
Decl : Node_Id;
Type_Def : Node_Id;
function Mentions_T (Acc_Def : Node_Id) return Boolean;
-- Check whether an access definition includes a reference to
-- the enclosing record type. The reference can be a subtype
-- mark in the access definition itself, or a 'Class attribute
-- reference, or recursively a reference appearing in a parameter
-- type in an access_to_subprogram definition.
----------------
-- Mentions_T --
----------------
function Mentions_T (Acc_Def : Node_Id) return Boolean is
Subt : Node_Id;
begin
if No (Access_To_Subprogram_Definition (Acc_Def)) then
Subt := Subtype_Mark (Acc_Def);
if Nkind (Subt) = N_Identifier then
return Chars (Subt) = Chars (T);
-- A reference to the current type may appear as the prefix
-- of a 'Class attribute.
elsif Nkind (Subt) = N_Attribute_Reference
and then Attribute_Name (Subt) = Name_Class
and then Is_Entity_Name (Prefix (Subt))
then
return (Chars (Prefix (Subt))) = Chars (T);
else
return False;
end if;
else
-- Component is an access_to_subprogram: examine its formals
declare
Param_Spec : Node_Id;
begin
Param_Spec :=
First
(Parameter_Specifications
(Access_To_Subprogram_Definition (Acc_Def)));
while Present (Param_Spec) loop
if Nkind (Parameter_Type (Param_Spec))
= N_Access_Definition
and then Mentions_T (Parameter_Type (Param_Spec))
then
return True;
end if;
Next (Param_Spec);
end loop;
return False;
end;
end if;
end Mentions_T;
-- Start of processing for Check_Anonymous_Access_Types
begin
if No (Comp_List) then
return;
end if;
Comp := First (Component_Items (Comp_List));
while Present (Comp) loop
if Nkind (Comp) = N_Component_Declaration
and then
Present (Access_Definition (Component_Definition (Comp)))
and then
Mentions_T (Access_Definition (Component_Definition (Comp)))
then
Acc_Def :=
Access_To_Subprogram_Definition
(Access_Definition (Component_Definition (Comp)));
Make_Incomplete_Type_Declaration;
Anon_Access :=
Make_Defining_Identifier (Loc,
Chars => New_Internal_Name ('S'));
-- Create a declaration for the anonymous access type: either
-- an access_to_object or an access_to_subprogram.
if Present (Acc_Def) then
if Nkind (Acc_Def) = N_Access_Function_Definition then
Type_Def :=
Make_Access_Function_Definition (Loc,
Parameter_Specifications =>
Parameter_Specifications (Acc_Def),
Result_Definition => Result_Definition (Acc_Def));
else
Type_Def :=
Make_Access_Procedure_Definition (Loc,
Parameter_Specifications =>
Parameter_Specifications (Acc_Def));
end if;
else
Type_Def :=
Make_Access_To_Object_Definition (Loc,
Subtype_Indication =>
Relocate_Node
(Subtype_Mark
(Access_Definition
(Component_Definition (Comp)))));
end if;
Decl := Make_Full_Type_Declaration (Loc,
Defining_Identifier => Anon_Access,
Type_Definition => Type_Def);
Insert_Before (N, Decl);
Analyze (Decl);
Rewrite (Component_Definition (Comp),
Make_Component_Definition (Loc,
Subtype_Indication =>
New_Occurrence_Of (Anon_Access, Loc)));
Set_Ekind (Anon_Access, E_Anonymous_Access_Type);
Set_Is_Local_Anonymous_Access (Anon_Access);
end if;
Next (Comp);
end loop;
if Present (Variant_Part (Comp_List)) then
declare
V : Node_Id;
begin
V := First_Non_Pragma (Variants (Variant_Part (Comp_List)));
while Present (V) loop
Check_Anonymous_Access_Types (Component_List (V));
Next_Non_Pragma (V);
end loop;
end;
end if;
end Check_Anonymous_Access_Types;
--------------------------------------
-- Make_Incomplete_Type_Declaration --
--------------------------------------
procedure Make_Incomplete_Type_Declaration is
Decl : Node_Id;
H : Entity_Id;
begin
-- If there is a previous partial view, no need to create a new one
-- If the partial view is incomplete, it is given by Prev. If it is
-- a private declaration, full declaration is flagged accordingly.
if Prev /= T
or else Has_Private_Declaration (T)
then
return;
elsif No (Inc_T) then
Inc_T := Make_Defining_Identifier (Loc, Chars (T));
Decl := Make_Incomplete_Type_Declaration (Loc, Inc_T);
-- Type has already been inserted into the current scope.
-- Remove it, and add incomplete declaration for type, so
-- that subsequent anonymous access types can use it.
H := Current_Entity (T);
if H = T then
Set_Name_Entity_Id (Chars (T), Empty);
else
while Present (H)
and then Homonym (H) /= T
loop
H := Homonym (T);
end loop;
Set_Homonym (H, Homonym (T));
end if;
Insert_Before (N, Decl);
Analyze (Decl);
Set_Full_View (Inc_T, T);
if Tagged_Present (Def) then
Make_Class_Wide_Type (Inc_T);
Set_Class_Wide_Type (T, Class_Wide_Type (Inc_T));
Set_Etype (Class_Wide_Type (T), T);
end if;
end if;
end Make_Incomplete_Type_Declaration;
-- Start of processing for Record_Type_Declaration
begin
-- These flags must be initialized before calling Process_Discriminants
-- because this routine makes use of them.
Set_Ekind (T, E_Record_Type);
Set_Etype (T, T);
Init_Size_Align (T);
Set_Abstract_Interfaces (T, No_Elist);
Set_Stored_Constraint (T, No_Elist);
-- Normal case
if Ada_Version < Ada_05
or else not Interface_Present (Def)
then
-- The flag Is_Tagged_Type might have already been set by
-- Find_Type_Name if it detected an error for declaration T. This
-- arises in the case of private tagged types where the full view
-- omits the word tagged.
Is_Tagged :=
Tagged_Present (Def)
or else (Serious_Errors_Detected > 0 and then Is_Tagged_Type (T));
Set_Is_Tagged_Type (T, Is_Tagged);
Set_Is_Limited_Record (T, Limited_Present (Def));
-- Type is abstract if full declaration carries keyword, or if
-- previous partial view did.
Set_Is_Abstract (T, Is_Abstract (T)
or else Abstract_Present (Def));
else
Is_Tagged := True;
Analyze_Interface_Declaration (T, Def);
end if;
-- First pass: if there are self-referential access components,
-- create the required anonymous access type declarations, and if
-- need be an incomplete type declaration for T itself.
Check_Anonymous_Access_Types (Component_List (Def));
if Ada_Version >= Ada_05
and then Present (Interface_List (Def))
then
declare
Iface : Node_Id;
Iface_Def : Node_Id;
Iface_Typ : Entity_Id;
begin
Iface := First (Interface_List (Def));
while Present (Iface) loop
Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
Iface_Def := Type_Definition (Parent (Iface_Typ));
if not Is_Interface (Iface_Typ) then
Error_Msg_NE ("(Ada 2005) & must be an interface",
Iface, Iface_Typ);
else
-- "The declaration of a specific descendant of an
-- interface type freezes the interface type" RM 13.14
Freeze_Before (N, Iface_Typ);
-- Ada 2005 (AI-345): Protected interfaces can only
-- inherit from limited, synchronized or protected
-- interfaces.
if Protected_Present (Def) then
if Limited_Present (Iface_Def)
or else Synchronized_Present (Iface_Def)
or else Protected_Present (Iface_Def)
then
null;
elsif Task_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) protected interface cannot"
& " inherit from task interface", Iface);
else
Error_Msg_N ("(Ada 2005) protected interface cannot"
& " inherit from non-limited interface", Iface);
end if;
-- Ada 2005 (AI-345): Synchronized interfaces can only
-- inherit from limited and synchronized.
elsif Synchronized_Present (Def) then
if Limited_Present (Iface_Def)
or else Synchronized_Present (Iface_Def)
then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) synchronized interface " &
"cannot inherit from protected interface", Iface);
elsif Task_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) synchronized interface " &
"cannot inherit from task interface", Iface);
else
Error_Msg_N ("(Ada 2005) synchronized interface " &
"cannot inherit from non-limited interface",
Iface);
end if;
-- Ada 2005 (AI-345): Task interfaces can only inherit
-- from limited, synchronized or task interfaces.
elsif Task_Present (Def) then
if Limited_Present (Iface_Def)
or else Synchronized_Present (Iface_Def)
or else Task_Present (Iface_Def)
then
null;
elsif Protected_Present (Iface_Def) then
Error_Msg_N ("(Ada 2005) task interface cannot" &
" inherit from protected interface", Iface);
else
Error_Msg_N ("(Ada 2005) task interface cannot" &
" inherit from non-limited interface", Iface);
end if;
end if;
end if;
Next (Iface);
end loop;
Set_Abstract_Interfaces (T, New_Elmt_List);
Collect_Interfaces (Def, T);
end;
end if;
-- Records constitute a scope for the component declarations within.
-- The scope is created prior to the processing of these declarations.
-- Discriminants are processed first, so that they are visible when
-- processing the other components. The Ekind of the record type itself
-- is set to E_Record_Type (subtypes appear as E_Record_Subtype).
-- Enter record scope
New_Scope (T);
-- If an incomplete or private type declaration was already given for
-- the type, then this scope already exists, and the discriminants have
-- been declared within. We must verify that the full declaration
-- matches the incomplete one.
Check_Or_Process_Discriminants (N, T, Prev);
Set_Is_Constrained (T, not Has_Discriminants (T));
Set_Has_Delayed_Freeze (T, True);
-- For tagged types add a manually analyzed component corresponding
-- to the component _tag, the corresponding piece of tree will be
-- expanded as part of the freezing actions if it is not a CPP_Class.
if Is_Tagged then
-- Do not add the tag unless we are in expansion mode
if Expander_Active then
Tag_Comp := Make_Defining_Identifier (Sloc (Def), Name_uTag);
Enter_Name (Tag_Comp);
Set_Is_Tag (Tag_Comp);
Set_Is_Aliased (Tag_Comp);
Set_Ekind (Tag_Comp, E_Component);
Set_Etype (Tag_Comp, RTE (RE_Tag));
Set_DT_Entry_Count (Tag_Comp, No_Uint);
Set_Original_Record_Component (Tag_Comp, Tag_Comp);
Init_Component_Location (Tag_Comp);
-- Ada 2005 (AI-251): Addition of the Tag corresponding to all the
-- implemented interfaces
Add_Interface_Tag_Components (N, T);
end if;
Make_Class_Wide_Type (T);
Set_Primitive_Operations (T, New_Elmt_List);
end if;
-- We must suppress range checks when processing the components
-- of a record in the presence of discriminants, since we don't
-- want spurious checks to be generated during their analysis, but
-- must reset the Suppress_Range_Checks flags after having processed
-- the record definition.
if Has_Discriminants (T) and then not Range_Checks_Suppressed (T) then
Set_Kill_Range_Checks (T, True);
Record_Type_Definition (Def, Prev);
Set_Kill_Range_Checks (T, False);
else
Record_Type_Definition (Def, Prev);
end if;
-- Exit from record scope
End_Scope;
if Expander_Active
and then Is_Tagged
and then not Is_Empty_List (Interface_List (Def))
then
-- Ada 2005 (AI-251): Derive the interface subprograms of all the
-- implemented interfaces and check if some of the subprograms
-- inherited from the ancestor cover some interface subprogram.
Derive_Interface_Subprograms (T);
end if;
end Record_Type_Declaration;
----------------------------
-- Record_Type_Definition --
----------------------------
procedure Record_Type_Definition (Def : Node_Id; Prev_T : Entity_Id) is
Component : Entity_Id;
Ctrl_Components : Boolean := False;
Final_Storage_Only : Boolean;
T : Entity_Id;
begin
if Ekind (Prev_T) = E_Incomplete_Type then
T := Full_View (Prev_T);
else
T := Prev_T;
end if;
Final_Storage_Only := not Is_Controlled (T);
-- Ada 2005: check whether an explicit Limited is present in a derived
-- type declaration.
if Nkind (Parent (Def)) = N_Derived_Type_Definition
and then Limited_Present (Parent (Def))
then
Set_Is_Limited_Record (T);
end if;
-- If the component list of a record type is defined by the reserved
-- word null and there is no discriminant part, then the record type has
-- no components and all records of the type are null records (RM 3.7)
-- This procedure is also called to process the extension part of a
-- record extension, in which case the current scope may have inherited
-- components.
if No (Def)
or else No (Component_List (Def))
or else Null_Present (Component_List (Def))
then
null;
else
Analyze_Declarations (Component_Items (Component_List (Def)));
if Present (Variant_Part (Component_List (Def))) then
Analyze (Variant_Part (Component_List (Def)));
end if;
end if;
-- After completing the semantic analysis of the record definition,
-- record components, both new and inherited, are accessible. Set
-- their kind accordingly.
Component := First_Entity (Current_Scope);
while Present (Component) loop
if Ekind (Component) = E_Void then
Set_Ekind (Component, E_Component);
Init_Component_Location (Component);
end if;
if Has_Task (Etype (Component)) then
Set_Has_Task (T);
end if;
if Ekind (Component) /= E_Component then
null;
elsif Has_Controlled_Component (Etype (Component))
or else (Chars (Component) /= Name_uParent
and then Is_Controlled (Etype (Component)))
then
Set_Has_Controlled_Component (T, True);
Final_Storage_Only := Final_Storage_Only
and then Finalize_Storage_Only (Etype (Component));
Ctrl_Components := True;
end if;
Next_Entity (Component);
end loop;
-- A type is Finalize_Storage_Only only if all its controlled
-- components are so.
if Ctrl_Components then
Set_Finalize_Storage_Only (T, Final_Storage_Only);
end if;
-- Place reference to end record on the proper entity, which may
-- be a partial view.
if Present (Def) then
Process_End_Label (Def, 'e', Prev_T);
end if;
end Record_Type_Definition;
------------------------
-- Replace_Components --
------------------------
procedure Replace_Components (Typ : Entity_Id; Decl : Node_Id) is
function Process (N : Node_Id) return Traverse_Result;
-------------
-- Process --
-------------
function Process (N : Node_Id) return Traverse_Result is
Comp : Entity_Id;
begin
if Nkind (N) = N_Discriminant_Specification then
Comp := First_Discriminant (Typ);
while Present (Comp) loop
if Chars (Comp) = Chars (Defining_Identifier (N)) then
Set_Defining_Identifier (N, Comp);
exit;
end if;
Next_Discriminant (Comp);
end loop;
elsif Nkind (N) = N_Component_Declaration then
Comp := First_Component (Typ);
while Present (Comp) loop
if Chars (Comp) = Chars (Defining_Identifier (N)) then
Set_Defining_Identifier (N, Comp);
exit;
end if;
Next_Component (Comp);
end loop;
end if;
return OK;
end Process;
procedure Replace is new Traverse_Proc (Process);
-- Start of processing for Replace_Components
begin
Replace (Decl);
end Replace_Components;
-------------------------------
-- Set_Completion_Referenced --
-------------------------------
procedure Set_Completion_Referenced (E : Entity_Id) is
begin
-- If in main unit, mark entity that is a completion as referenced,
-- warnings go on the partial view when needed.
if In_Extended_Main_Source_Unit (E) then
Set_Referenced (E);
end if;
end Set_Completion_Referenced;
---------------------
-- Set_Fixed_Range --
---------------------
-- The range for fixed-point types is complicated by the fact that we
-- do not know the exact end points at the time of the declaration. This
-- is true for three reasons:
-- A size clause may affect the fudging of the end-points
-- A small clause may affect the values of the end-points
-- We try to include the end-points if it does not affect the size
-- This means that the actual end-points must be established at the point
-- when the type is frozen. Meanwhile, we first narrow the range as
-- permitted (so that it will fit if necessary in a small specified size),
-- and then build a range subtree with these narrowed bounds.
-- Set_Fixed_Range constructs the range from real literal values, and sets
-- the range as the Scalar_Range of the given fixed-point type entity.
-- The parent of this range is set to point to the entity so that it is
-- properly hooked into the tree (unlike normal Scalar_Range entries for
-- other scalar types, which are just pointers to the range in the
-- original tree, this would otherwise be an orphan).
-- The tree is left unanalyzed. When the type is frozen, the processing
-- in Freeze.Freeze_Fixed_Point_Type notices that the range is not
-- analyzed, and uses this as an indication that it should complete
-- work on the range (it will know the final small and size values).
procedure Set_Fixed_Range
(E : Entity_Id;
Loc : Source_Ptr;
Lo : Ureal;
Hi : Ureal)
is
S : constant Node_Id :=
Make_Range (Loc,
Low_Bound => Make_Real_Literal (Loc, Lo),
High_Bound => Make_Real_Literal (Loc, Hi));
begin
Set_Scalar_Range (E, S);
Set_Parent (S, E);
end Set_Fixed_Range;
----------------------------------
-- Set_Scalar_Range_For_Subtype --
----------------------------------
procedure Set_Scalar_Range_For_Subtype
(Def_Id : Entity_Id;
R : Node_Id;
Subt : Entity_Id)
is
Kind : constant Entity_Kind := Ekind (Def_Id);
begin
Set_Scalar_Range (Def_Id, R);
-- We need to link the range into the tree before resolving it so
-- that types that are referenced, including importantly the subtype
-- itself, are properly frozen (Freeze_Expression requires that the
-- expression be properly linked into the tree). Of course if it is
-- already linked in, then we do not disturb the current link.
if No (Parent (R)) then
Set_Parent (R, Def_Id);
end if;
-- Reset the kind of the subtype during analysis of the range, to
-- catch possible premature use in the bounds themselves.
Set_Ekind (Def_Id, E_Void);
Process_Range_Expr_In_Decl (R, Subt);
Set_Ekind (Def_Id, Kind);
end Set_Scalar_Range_For_Subtype;
--------------------------------------------------------
-- Set_Stored_Constraint_From_Discriminant_Constraint --
--------------------------------------------------------
procedure Set_Stored_Constraint_From_Discriminant_Constraint
(E : Entity_Id)
is
begin
-- Make sure set if encountered during Expand_To_Stored_Constraint
Set_Stored_Constraint (E, No_Elist);
-- Give it the right value
if Is_Constrained (E) and then Has_Discriminants (E) then
Set_Stored_Constraint (E,
Expand_To_Stored_Constraint (E, Discriminant_Constraint (E)));
end if;
end Set_Stored_Constraint_From_Discriminant_Constraint;
-------------------------------------
-- Signed_Integer_Type_Declaration --
-------------------------------------
procedure Signed_Integer_Type_Declaration (T : Entity_Id; Def : Node_Id) is
Implicit_Base : Entity_Id;
Base_Typ : Entity_Id;
Lo_Val : Uint;
Hi_Val : Uint;
Errs : Boolean := False;
Lo : Node_Id;
Hi : Node_Id;
function Can_Derive_From (E : Entity_Id) return Boolean;
-- Determine whether given bounds allow derivation from specified type
procedure Check_Bound (Expr : Node_Id);
-- Check bound to make sure it is integral and static. If not, post
-- appropriate error message and set Errs flag
---------------------
-- Can_Derive_From --
---------------------
-- Note we check both bounds against both end values, to deal with
-- strange types like ones with a range of 0 .. -12341234.
function Can_Derive_From (E : Entity_Id) return Boolean is
Lo : constant Uint := Expr_Value (Type_Low_Bound (E));
Hi : constant Uint := Expr_Value (Type_High_Bound (E));
begin
return Lo <= Lo_Val and then Lo_Val <= Hi
and then
Lo <= Hi_Val and then Hi_Val <= Hi;
end Can_Derive_From;
-----------------
-- Check_Bound --
-----------------
procedure Check_Bound (Expr : Node_Id) is
begin
-- If a range constraint is used as an integer type definition, each
-- bound of the range must be defined by a static expression of some
-- integer type, but the two bounds need not have the same integer
-- type (Negative bounds are allowed.) (RM 3.5.4)
if not Is_Integer_Type (Etype (Expr)) then
Error_Msg_N
("integer type definition bounds must be of integer type", Expr);
Errs := True;
elsif not Is_OK_Static_Expression (Expr) then
Flag_Non_Static_Expr
("non-static expression used for integer type bound!", Expr);
Errs := True;
-- The bounds are folded into literals, and we set their type to be
-- universal, to avoid typing difficulties: we cannot set the type
-- of the literal to the new type, because this would be a forward
-- reference for the back end, and if the original type is user-
-- defined this can lead to spurious semantic errors (e.g. 2928-003).
else
if Is_Entity_Name (Expr) then
Fold_Uint (Expr, Expr_Value (Expr), True);
end if;
Set_Etype (Expr, Universal_Integer);
end if;
end Check_Bound;
-- Start of processing for Signed_Integer_Type_Declaration
begin
-- Create an anonymous base type
Implicit_Base :=
Create_Itype (E_Signed_Integer_Type, Parent (Def), T, 'B');
-- Analyze and check the bounds, they can be of any integer type
Lo := Low_Bound (Def);
Hi := High_Bound (Def);
-- Arbitrarily use Integer as the type if either bound had an error
if Hi = Error or else Lo = Error then
Base_Typ := Any_Integer;
Set_Error_Posted (T, True);
-- Here both bounds are OK expressions
else
Analyze_And_Resolve (Lo, Any_Integer);
Analyze_And_Resolve (Hi, Any_Integer);
Check_Bound (Lo);
Check_Bound (Hi);
if Errs then
Hi := Type_High_Bound (Standard_Long_Long_Integer);
Lo := Type_Low_Bound (Standard_Long_Long_Integer);
end if;
-- Find type to derive from
Lo_Val := Expr_Value (Lo);
Hi_Val := Expr_Value (Hi);
if Can_Derive_From (Standard_Short_Short_Integer) then
Base_Typ := Base_Type (Standard_Short_Short_Integer);
elsif Can_Derive_From (Standard_Short_Integer) then
Base_Typ := Base_Type (Standard_Short_Integer);
elsif Can_Derive_From (Standard_Integer) then
Base_Typ := Base_Type (Standard_Integer);
elsif Can_Derive_From (Standard_Long_Integer) then
Base_Typ := Base_Type (Standard_Long_Integer);
elsif Can_Derive_From (Standard_Long_Long_Integer) then
Base_Typ := Base_Type (Standard_Long_Long_Integer);
else
Base_Typ := Base_Type (Standard_Long_Long_Integer);
Error_Msg_N ("integer type definition bounds out of range", Def);
Hi := Type_High_Bound (Standard_Long_Long_Integer);
Lo := Type_Low_Bound (Standard_Long_Long_Integer);
end if;
end if;
-- Complete both implicit base and declared first subtype entities
Set_Etype (Implicit_Base, Base_Typ);
Set_Scalar_Range (Implicit_Base, Scalar_Range (Base_Typ));
Set_Size_Info (Implicit_Base, (Base_Typ));
Set_RM_Size (Implicit_Base, RM_Size (Base_Typ));
Set_First_Rep_Item (Implicit_Base, First_Rep_Item (Base_Typ));
Set_Ekind (T, E_Signed_Integer_Subtype);
Set_Etype (T, Implicit_Base);
Set_Size_Info (T, (Implicit_Base));
Set_First_Rep_Item (T, First_Rep_Item (Implicit_Base));
Set_Scalar_Range (T, Def);
Set_RM_Size (T, UI_From_Int (Minimum_Size (T)));
Set_Is_Constrained (T);
end Signed_Integer_Type_Declaration;
end Sem_Ch3;