001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License. 
016     *
017     */
018    package org.apache.bcel.generic;
019    
020    import org.apache.bcel.classfile.LineNumber;
021    
022    /** 
023     * This class represents a line number within a method, i.e., give an instruction
024     * a line number corresponding to the source code line.
025     *
026     * @version $Id: LineNumberGen.java 1152072 2011-07-29 01:54:05Z dbrosius $
027     * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
028     * @see     LineNumber
029     * @see     MethodGen
030     */
031    public class LineNumberGen implements InstructionTargeter, Cloneable, java.io.Serializable {
032    
033        private static final long serialVersionUID = 4939965573936108738L;
034        private InstructionHandle ih;
035        private int src_line;
036    
037    
038        /**
039         * Create a line number.
040         *
041         * @param ih instruction handle to reference
042         */
043        public LineNumberGen(InstructionHandle ih, int src_line) {
044            setInstruction(ih);
045            setSourceLine(src_line);
046        }
047    
048    
049        /**
050         * @return true, if ih is target of this line number
051         */
052        public boolean containsTarget( InstructionHandle ih ) {
053            return this.ih == ih;
054        }
055    
056    
057        /**
058         * @param old_ih old target
059         * @param new_ih new target
060         */
061        public void updateTarget( InstructionHandle old_ih, InstructionHandle new_ih ) {
062            if (old_ih != ih) {
063                throw new ClassGenException("Not targeting " + old_ih + ", but " + ih + "}");
064            } else {
065                setInstruction(new_ih);
066            }
067        }
068    
069    
070        /**
071         * Get LineNumber attribute .
072         *
073         * This relies on that the instruction list has already been dumped to byte code or
074         * or that the `setPositions' methods has been called for the instruction list.
075         */
076        public LineNumber getLineNumber() {
077            return new LineNumber(ih.getPosition(), src_line);
078        }
079    
080    
081        public void setInstruction( InstructionHandle ih ) {
082            BranchInstruction.notifyTarget(this.ih, ih, this);
083            this.ih = ih;
084        }
085    
086    
087        @Override
088        public Object clone() {
089            try {
090                return super.clone();
091            } catch (CloneNotSupportedException e) {
092                System.err.println(e);
093                return null;
094            }
095        }
096    
097    
098        public InstructionHandle getInstruction() {
099            return ih;
100        }
101    
102    
103        public void setSourceLine( int src_line ) {
104            this.src_line = src_line;
105        }
106    
107    
108        public int getSourceLine() {
109            return src_line;
110        }
111    }