001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: MatchGenerator.java 468649 2006-10-28 07:00:55Z minchau $
020     */
021    
022    package org.apache.xalan.xsltc.compiler.util;
023    
024    import org.apache.bcel.generic.ALOAD;
025    import org.apache.bcel.generic.ConstantPoolGen;
026    import org.apache.bcel.generic.ILOAD;
027    import org.apache.bcel.generic.ISTORE;
028    import org.apache.bcel.generic.Instruction;
029    import org.apache.bcel.generic.InstructionList;
030    import org.apache.bcel.generic.Type;
031    
032    /**
033     * @author Jacek Ambroziak
034     * @author Santiago Pericas-Geertsen
035     */
036    public final class MatchGenerator extends MethodGenerator {
037        private static int CURRENT_INDEX = 1;
038    
039        private int _iteratorIndex = INVALID_INDEX;
040    
041        private final Instruction _iloadCurrent;
042        private final Instruction _istoreCurrent;
043        private Instruction _aloadDom;
044        
045        public MatchGenerator(int access_flags, Type return_type, 
046                              Type[] arg_types, String[] arg_names, 
047                              String method_name, String class_name,
048                              InstructionList il, ConstantPoolGen cp) {
049            super(access_flags, return_type, arg_types, arg_names, method_name, 
050                  class_name, il, cp);
051            
052            _iloadCurrent = new ILOAD(CURRENT_INDEX);
053            _istoreCurrent = new ISTORE(CURRENT_INDEX);
054        }
055    
056        public Instruction loadCurrentNode() {
057            return _iloadCurrent;
058        }
059    
060        public Instruction storeCurrentNode() {
061            return _istoreCurrent;
062        }
063        
064        public int getHandlerIndex() {
065            return INVALID_INDEX;           // not available
066        }
067    
068        /**
069         * Get index of the register where the DOM is stored.
070         */
071        public Instruction loadDOM() {
072            return _aloadDom;
073        }
074    
075        /**
076         * Set index where the reference to the DOM is stored.
077         */
078        public void setDomIndex(int domIndex) {
079            _aloadDom = new ALOAD(domIndex);
080        }
081    
082        /**
083         * Get index of the register where the current iterator is stored.
084         */
085        public int getIteratorIndex() {
086            return _iteratorIndex;
087        }
088    
089        /**
090         * Set index of the register where the current iterator is stored.
091         */
092        public void setIteratorIndex(int iteratorIndex) {
093            _iteratorIndex = iteratorIndex;
094        }
095    
096        public int getLocalIndex(String name) {
097            if (name.equals("current")) {
098                return CURRENT_INDEX;
099            }
100            return super.getLocalIndex(name);
101        }
102    }