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.javaflow.bytecode.transformation.asm;
18
19 import java.io.IOException;
20 import java.io.InputStream;
21
22 import org.apache.commons.javaflow.bytecode.transformation.ResourceTransformer;
23 import org.objectweb.asm.ClassReader;
24 import org.objectweb.asm.ClassWriter;
25 import org.objectweb.asm.util.CheckClassAdapter;
26
27
28 /**
29 * AsmClassTransformer
30 *
31 * @author Eugene Kuleshov
32 */
33 public final class AsmClassTransformer implements ResourceTransformer {
34
35 public byte[] transform(InputStream is) throws IOException {
36 return transform(new ClassReader(is));
37 }
38
39 public byte[] transform(final byte[] original) {
40 return transform(new ClassReader(original));
41 }
42
43 private byte[] transform(ClassReader cr) {
44 // final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
45 final ClassWriter cw = new ClassWriter(true, false);
46
47 // print bytecode before transformation
48 // cr.accept(new TraceClassVisitor(new ContinuationClassAdapter(this, cw), new PrintWriter(System.out)), false);
49
50 // prints bytecode after transformation
51 // cr.accept(new ContinuationClassAdapter(this, new TraceClassVisitor(cw, new PrintWriter(System.err))), 0);
52 // cr.accept(new ContinuationClassAdapter(this, new TraceClassVisitor(cw, new PrintWriter(System.err))), false);
53
54 cr.accept(new ContinuationClassAdapter(new CheckClassAdapter(cw)), false);
55
56 byte[] bytecode = cw.toByteArray();
57
58 // CheckClassAdapter.verify(new ClassReader(bytecode), true);
59 // new ClassReader(bytecode).accept(new ASMifierClassVisitor(new PrintWriter(System.err)), false);
60
61 // ClassWriter cww = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
62 // new ClassReader(bytecode).accept(cww, ClassReader.SKIP_DEBUG);
63 // new ClassReader(cww.toByteArray()).accept(new TraceClassVisitor(new PrintWriter(System.err)), 0);
64
65 return bytecode;
66 }
67
68 }
69