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	/*
	* Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.tools.tree;

	import sun.tools.java.*;
	import sun.tools.tree.*;
	import java.util.Vector;

	/**
	* A local Field
	*
	* WARNING: The contents of this source file are not part of any
	* supported API. Code that depends on them does so at its own risk:
	* they are subject to change or removal without notice.
	*/

	public
	class LocalMember extends MemberDefinition {
	/**
	* The number of the variable
	*/
	int number = -1;

	/**
	* Some statistics
	*/
	int readcount;
	int writecount;

	/**
	* An indication of which block the variable comes from.
	* Helps identify uplevel references.
	*/
	int scopeNumber;

	/**
	* Return current nesting level, i.e., the value of 'scopeNumber'.
	* Made public for the benefit of 'ClassDefinition.resolveName'.
	*/
	public int getScopeNumber() {
	return scopeNumber;
	}

	/**
	* Used by copyInline to record the original of this copy.
	*/
	LocalMember originalOfCopy;

	/**
	* The previous local variable, this list is used to build a nested
	* context of local variables.
	*/
	LocalMember prev;

	/**
	* Constructor
	*/
	public LocalMember(long where, ClassDefinition clazz, int modifiers, Type type,
	Identifier name) {
	super(where, clazz, modifiers, type, name, null, null);
	}

	/**
	* Constructor for a block-inner class.
	*/
	public LocalMember(ClassDefinition innerClass) {
	super(innerClass);

	// The class's "real" name is something like "foo$1$bar", but locally:
	name = innerClass.getLocalName();
	}

	/**
	* Constructor for a proxy to an instance or class variable.
	*/
	LocalMember(MemberDefinition field) {
	this(0, null, 0, field.getType(), idClass);
	// use this random slot to store the info:
	accessPeer = field;
	}

	/**
	* Is this a proxy for the given field?
	*/
	final MemberDefinition getMember() {
	return (name == idClass) ? accessPeer : null;
	}

	/**
	* Special checks
	*/
	public boolean isLocal() {
	return true;
	}

	/**
	* Make a copy of this field, which is an argument to a method
	* or constructor. Arrange so that when occurrences of the field
	* are encountered in an immediately following copyInline() operation,
	* the expression nodes will replace the original argument by the
	* fresh copy.
	*/
	public LocalMember copyInline(Context ctx) {
	LocalMember copy = new LocalMember(where, clazz, modifiers, type, name);
	copy.readcount = this.readcount;
	copy.writecount = this.writecount;

	copy.originalOfCopy = this;

	// Make a temporary link from the original.
	// It only stays valid through the next call to copyInline().
	// (This means that recursive inlining won't work.)
	// To stay honest, we mark these inline copies:
	copy.addModifiers(M_LOCAL);
	if (this.accessPeer != null
	&& (this.accessPeer.getModifiers() & M_LOCAL) == 0) {
	throw new CompilerError("local copyInline");
	}
	this.accessPeer = copy;

	return copy;
	}

	/**
	* Returns the previous result of copyInline(ctx).
	* Must be called in the course of an Expression.copyInline()
	* operation that immediately follows the LocalMember.copyInline().
	* Return "this" if there is no such copy.
	*/
	public LocalMember getCurrentInlineCopy(Context ctx) {
	MemberDefinition accessPeer = this.accessPeer;
	if (accessPeer != null && (accessPeer.getModifiers() & M_LOCAL) != 0) {
	LocalMember copy = (LocalMember)accessPeer;
	return copy;
	}
	return this;
	}

	/**
	* May inline copies of all the arguments of the given method.
	*/
	static public LocalMember[] copyArguments(Context ctx, MemberDefinition field) {
	Vector v = field.getArguments();
	LocalMember res[] = new LocalMember[v.size()];
	v.copyInto(res);
	for (int i = 0; i < res.length; i++) {
	res[i] = res[i].copyInline(ctx);
	}
	return res;
	}

	/**
	* Call this when finished with the result of a copyArguments() call.
	*/
	static public void doneWithArguments(Context ctx, LocalMember res[]) {
	for (int i = 0; i < res.length; i++) {
	if (res[i].originalOfCopy.accessPeer == res[i]) {
	res[i].originalOfCopy.accessPeer = null;
	}
	}
	}

	/**
	* Is this local variable's value stable and simple enough to be directly
	* substituted for occurrences of the variable itself?
	* (This decision is made by VarDeclarationStatement.inline().)
	*/
	public boolean isInlineable(Environment env, boolean fromFinal) {
	return (getModifiers() & M_INLINEABLE) != 0;
	}

	/**
	* Check if used
	*/
	public boolean isUsed() {
	return (readcount != 0) \|\| (writecount != 0);
	}

	// Used by class Context, only on members of MemberDefinition.available:
	LocalMember getAccessVar() {
	return (LocalMember)accessPeer;
	}
	void setAccessVar(LocalMember f) {
	accessPeer = f;
	}
	// Used by class Context, only on "AccessVar" constructor args
	MemberDefinition getAccessVarMember() {
	return accessPeer;
	}
	void setAccessVarMember(MemberDefinition f) {
	accessPeer = f;
	}


	/**
	* Return value
	*/
	public Node getValue(Environment env) {
	return (Expression)getValue();
	}

	/**
	* Value number for vsets, or -1 if none.
	*/
	public int getNumber(Context ctx) {
	return number;
	}
	}

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