1/*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5/*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements.  See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License.  You may obtain a copy of the License at
12 *
13 *      http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22package com.sun.org.apache.bcel.internal.generic;
23
24
25import com.sun.org.apache.bcel.internal.classfile.*;
26
27/**
28 * This class represents a line number within a method, i.e., give an instruction
29 * a line number corresponding to the source code line.
30 *
31 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
32 * @see     LineNumber
33 * @see     MethodGen
34 */
35public class LineNumberGen
36  implements InstructionTargeter, Cloneable, java.io.Serializable
37{
38  private InstructionHandle ih;
39  private int               src_line;
40
41  /**
42   * Create a line number.
43   *
44   * @param ih instruction handle to reference
45   */
46  public LineNumberGen(InstructionHandle ih, int src_line) {
47    setInstruction(ih);
48    setSourceLine(src_line);
49  }
50
51  /**
52   * @return true, if ih is target of this line number
53   */
54  @Override
55  public boolean containsTarget(InstructionHandle ih) {
56    return this.ih == ih;
57  }
58
59  /**
60   * @param old_ih old target
61   * @param new_ih new target
62   */
63  @Override
64  public void updateTarget(InstructionHandle old_ih, InstructionHandle new_ih) {
65    if(old_ih != ih)
66      throw new ClassGenException("Not targeting " + old_ih + ", but " + ih + "}");
67    else
68      setInstruction(new_ih);
69  }
70
71  /**
72   * Get LineNumber attribute .
73   *
74   * This relies on that the instruction list has already been dumped to byte code or
75   * or that the `setPositions' methods has been called for the instruction list.
76   */
77  public LineNumber getLineNumber() {
78    return new LineNumber(ih.getPosition(), src_line);
79  }
80
81  public final void setInstruction(InstructionHandle ih) {
82    BranchInstruction.notifyTargetChanging(this.ih, this);
83    this.ih = ih;
84    BranchInstruction.notifyTargetChanged(this.ih, this);
85  }
86
87  @Override
88  public Object clone() {
89    try {
90      return super.clone();
91    } catch(CloneNotSupportedException e) {
92      System.err.println(e);
93      return null;
94    }
95  }
96
97  public InstructionHandle getInstruction()               { return ih; }
98  public void              setSourceLine(int src_line)    { this.src_line = src_line; }
99  public int               getSourceLine()                { return src_line; }
100}
101