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	/*
	* reserved comment block
	* DO NOT REMOVE OR ALTER!
	*/
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.sun.org.apache.xalan.internal.xsltc.compiler;

	import com.sun.org.apache.bcel.internal.classfile.Field;
	import com.sun.org.apache.bcel.internal.generic.ACONST_NULL;
	import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
	import com.sun.org.apache.bcel.internal.generic.DCONST;
	import com.sun.org.apache.bcel.internal.generic.ICONST;
	import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
	import com.sun.org.apache.bcel.internal.generic.InstructionList;
	import com.sun.org.apache.bcel.internal.generic.PUTFIELD;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.BooleanType;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.IntType;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.NodeType;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.RealType;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
	import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

	final class Variable extends VariableBase {

	public int getIndex() {
	return (_local != null) ? _local.getIndex() : -1;
	}

	/**
	* Parse the contents of the variable
	*/
	public void parseContents(Parser parser) {
	// Parse 'name' and 'select' attributes plus parameter contents
	super.parseContents(parser);

	// Add a ref to this var to its enclosing construct
	SyntaxTreeNode parent = getParent();
	if (parent instanceof Stylesheet) {
	// Mark this as a global variable
	_isLocal = false;
	// Check if a global variable with this name already exists...
	Variable var = parser.getSymbolTable().lookupVariable(_name);
	// ...and if it does we need to check import precedence
	if (var != null) {
	final int us = this.getImportPrecedence();
	final int them = var.getImportPrecedence();
	// It is an error if the two have the same import precedence
	if (us == them) {
	final String name = _name.toString();
	reportError(this, parser, ErrorMsg.VARIABLE_REDEF_ERR,name);
	}
	// Ignore this if previous definition has higher precedence
	else if (them > us) {
	_ignore = true;
	copyReferences(var);
	return;
	}
	else {
	var.copyReferences(this);
	var.disable();
	}
	// Add this variable if we have higher precedence
	}
	((Stylesheet)parent).addVariable(this);
	parser.getSymbolTable().addVariable(this);
	}
	else {
	_isLocal = true;
	}
	}

	/**
	* Runs a type check on either the variable element body or the
	* expression in the 'select' attribute
	*/
	public Type typeCheck(SymbolTable stable) throws TypeCheckError {

	// Type check the 'select' expression if present
	if (_select != null) {
	_type = _select.typeCheck(stable);
	}
	// Type check the element contents otherwise
	else if (hasContents()) {
	typeCheckContents(stable);
	_type = Type.ResultTree;
	}
	else {
	_type = Type.Reference;
	}
	// The return type is void as the variable element does not leave
	// anything on the JVM's stack. The '_type' global will be returned
	// by the references to this variable, and not by the variable itself.
	return Type.Void;
	}

	/**
	* This method is part of a little trick that is needed to use local
	* variables inside nested for-each loops. See the initializeVariables()
	* method in the ForEach class for an explanation
	*/
	public void initialize(ClassGenerator classGen, MethodGenerator methodGen) {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

	// This is only done for local variables that are actually used
	if (isLocal() && !_refs.isEmpty()) {
	// Create a variable slot if none is allocated
	if (_local == null) {
	_local = methodGen.addLocalVariable2(getEscapedName(),
	_type.toJCType(),
	null);
	}
	// Push the default value on the JVM's stack
	if ((_type instanceof IntType) \|\|
	(_type instanceof NodeType) \|\|
	(_type instanceof BooleanType))
	il.append(new ICONST(0)); // 0 for node-id, integer and boolean
	else if (_type instanceof RealType)
	il.append(new DCONST(0)); // 0.0 for floating point numbers
	else
	il.append(new ACONST_NULL()); // and 'null' for anything else

	// Mark the store as the start of the live range of the variable
	_local.setStart(il.append(_type.STORE(_local.getIndex())));

	}
	}

	public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
	final ConstantPoolGen cpg = classGen.getConstantPool();
	final InstructionList il = methodGen.getInstructionList();

	// Don't generate code for unreferenced variables
	if (_refs.isEmpty()) {
	_ignore = true;
	}

	// Make sure that a variable instance is only compiled once
	if (_ignore) return;
	_ignore = true;

	final String name = getEscapedName();

	if (isLocal()) {
	// Compile variable value computation
	translateValue(classGen, methodGen);

	// Add a new local variable and store value
	boolean createLocal = _local == null;
	if (createLocal) {
	mapRegister(methodGen);
	}
	InstructionHandle storeInst =
	il.append(_type.STORE(_local.getIndex()));

	// If the local is just being created, mark the store as the start
	// of its live range. Note that it might have been created by
	// initializeVariables already, which would have set the start of
	// the live range already.
	if (createLocal) {
	_local.setStart(storeInst);
	}
	}
	else {
	String signature = _type.toSignature();

	// Global variables are store in class fields
	if (classGen.containsField(name) == null) {
	classGen.addField(new Field(ACC_PUBLIC,
	cpg.addUtf8(name),
	cpg.addUtf8(signature),
	null, cpg.getConstantPool()));

	// Push a reference to "this" for putfield
	il.append(classGen.loadTranslet());
	// Compile variable value computation
	translateValue(classGen, methodGen);
	// Store the variable in the allocated field
	il.append(new PUTFIELD(cpg.addFieldref(classGen.getClassName(),
	name, signature)));
	}
	}
	}
	}

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