jaxp/src/java.xml/share/classes/com/sun/org/apache/xalan/internal/xsltc/compiler/PositionCall.java

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/*
 * 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,
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package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.ILOAD;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.CompareGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TestGenerator;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
final class PositionCall extends FunctionCall {

    public PositionCall(QName fname) {
        super(fname);
    }

    public boolean hasPositionCall() {
        return true;
    }

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

        if (methodGen instanceof CompareGenerator) {
            il.append(((CompareGenerator)methodGen).loadCurrentNode());
        }
        else if (methodGen instanceof TestGenerator) {
            il.append(new ILOAD(POSITION_INDEX));
        }
        else {
            final ConstantPoolGen cpg = classGen.getConstantPool();
            final int index = cpg.addInterfaceMethodref(NODE_ITERATOR,
                                                       "getPosition",
                                                       "()I");

            il.append(methodGen.loadIterator());
            il.append(new INVOKEINTERFACE(index,1));
        }
    }
}