1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.bcel.generic;
20
21 import java.util.Objects;
22
23 import org.apache.bcel.classfile.LineNumber;
24
25 /**
26 * This class represents a line number within a method, that is, give an instruction a line number corresponding to the
27 * source code line.
28 *
29 * @see LineNumber
30 * @see MethodGen
31 */
32 public class LineNumberGen implements InstructionTargeter, Cloneable {
33
34 static final LineNumberGen[] EMPTY_ARRAY = {};
35
36 private InstructionHandle ih;
37 private int srcLine;
38
39 /**
40 * Create a line number.
41 *
42 * @param ih instruction handle to reference.
43 * @param srcLine source line number.
44 */
45 public LineNumberGen(final InstructionHandle ih, final int srcLine) {
46 setInstruction(ih);
47 setSourceLine(srcLine);
48 }
49
50 @Override
51 public Object clone() {
52 try {
53 return super.clone();
54 } catch (final CloneNotSupportedException e) {
55 throw new UnsupportedOperationException("Clone Not Supported", e); // never happens
56 }
57 }
58
59 /**
60 * @return true, if ih is target of this line number.
61 */
62 @Override
63 public boolean containsTarget(final InstructionHandle ih) {
64 return this.ih == ih;
65 }
66
67 /**
68 * Gets the instruction handle.
69 *
70 * @return The instruction handle.
71 */
72 public InstructionHandle getInstruction() {
73 return ih;
74 }
75
76 /**
77 * Gets LineNumber attribute.
78 *
79 * This relies on that the instruction list has already been dumped to byte code or that the 'setPositions' methods
80 * has been called for the instruction list.
81 *
82 * @return The line number attribute.
83 */
84 public LineNumber getLineNumber() {
85 return new LineNumber(ih.getPosition(), srcLine);
86 }
87
88 /**
89 * Gets the source line number.
90 *
91 * @return The source line number.
92 */
93 public int getSourceLine() {
94 return srcLine;
95 }
96
97 /**
98 * Sets the instruction handle.
99 *
100 * @param instructionHandle The instruction handle to set.
101 */
102 public void setInstruction(final InstructionHandle instructionHandle) { // TODO could be package-protected?
103 Objects.requireNonNull(instructionHandle, "instructionHandle");
104 BranchInstruction.notifyTarget(this.ih, instructionHandle, this);
105 this.ih = instructionHandle;
106 }
107
108 /**
109 * Sets the source line number.
110 *
111 * @param srcLine The source line number to set.
112 */
113 public void setSourceLine(final int srcLine) { // TODO could be package-protected?
114 this.srcLine = srcLine;
115 }
116
117 /**
118 * @param oldIh old target.
119 * @param newIh new target.
120 */
121 @Override
122 public void updateTarget(final InstructionHandle oldIh, final InstructionHandle newIh) {
123 if (oldIh != ih) {
124 throw new ClassGenException("Not targeting " + oldIh + ", but " + ih + "}");
125 }
126 setInstruction(newIh);
127 }
128 }