1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.compress.harmony.pack200;
18
19 import org.objectweb.asm.ClassReader;
20
21 /**
22 * Wrapper for ClassReader that enables pack200 to obtain extra class file information
23 */
24 public class Pack200ClassReader extends ClassReader {
25
26 private boolean lastConstantHadWideIndex;
27 private int lastUnsignedShort;
28 private boolean anySyntheticAttributes;
29 private String fileName;
30
31 /**
32 * @param b the contents of class file in the format of bytes
33 */
34 public Pack200ClassReader(final byte[] b) {
35 super(b);
36 }
37
38 public String getFileName() {
39 return fileName;
40 }
41
42 public boolean hasSyntheticAttributes() {
43 return anySyntheticAttributes;
44 }
45
46 public boolean lastConstantHadWideIndex() {
47 return lastConstantHadWideIndex;
48 }
49
50 @Override
51 public Object readConst(final int item, final char[] buf) {
52 lastConstantHadWideIndex = item == lastUnsignedShort;
53 return super.readConst(item, buf);
54 }
55
56 @Override
57 public int readUnsignedShort(final int index) {
58 // Doing this to check whether last load-constant instruction was ldc (18) or ldc_w (19)
59 // TODO: Assess whether this impacts on performance
60 final int unsignedShort = super.readUnsignedShort(index);
61 if (index > 0 && b[index - 1] == 19) {
62 lastUnsignedShort = unsignedShort;
63 } else {
64 lastUnsignedShort = Short.MIN_VALUE;
65 }
66 return unsignedShort;
67 }
68
69 @Override
70 public String readUTF8(final int arg0, final char[] arg1) {
71 final String utf8 = super.readUTF8(arg0, arg1);
72 if (!anySyntheticAttributes && "Synthetic".equals(utf8)) {
73 anySyntheticAttributes = true;
74 }
75 return utf8;
76 }
77
78 public void setFileName(final String name) {
79 this.fileName = name;
80 }
81
82 }