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.commons.compress.harmony.pack200;
20
21 import org.objectweb.asm.ClassReader;
22
23 /**
24 * Wrapper for ClassReader that enables pack200 to obtain extra class file information
25 */
26 public class Pack200ClassReader extends ClassReader {
27
28 private boolean lastConstantHadWideIndex;
29 private int lastUnsignedShort;
30 private boolean anySyntheticAttributes;
31 private String fileName;
32
33 /**
34 * @param b the contents of class file in the format of bytes
35 */
36 public Pack200ClassReader(final byte[] b) {
37 super(b);
38 }
39
40 public String getFileName() {
41 return fileName;
42 }
43
44 public boolean hasSyntheticAttributes() {
45 return anySyntheticAttributes;
46 }
47
48 public boolean lastConstantHadWideIndex() {
49 return lastConstantHadWideIndex;
50 }
51
52 @Override
53 public Object readConst(final int item, final char[] buf) {
54 lastConstantHadWideIndex = item == lastUnsignedShort;
55 return super.readConst(item, buf);
56 }
57
58 @Override
59 public int readUnsignedShort(final int index) {
60 // Doing this to check whether last load-constant instruction was ldc (18) or ldc_w (19)
61 // TODO: Assess whether this impacts on performance
62 final int unsignedShort = super.readUnsignedShort(index);
63 if (index > 0 && b[index - 1] == 19) {
64 lastUnsignedShort = unsignedShort;
65 } else {
66 lastUnsignedShort = Short.MIN_VALUE;
67 }
68 return unsignedShort;
69 }
70
71 @Override
72 public String readUTF8(final int arg0, final char[] arg1) {
73 final String utf8 = super.readUTF8(arg0, arg1);
74 if (!anySyntheticAttributes && "Synthetic".equals(utf8)) {
75 anySyntheticAttributes = true;
76 }
77 return utf8;
78 }
79
80 public void setFileName(final String name) {
81 this.fileName = name;
82 }
83
84 }