1 /*
2 * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package jdk.incubator.code.bytecode.impl;
26
27 import java.lang.classfile.ClassFile;
28 import java.lang.classfile.ClassTransform;
29
30 /**
31 * Applies bytecode compaction passes to a generated class file.
32 * <p>
33 * The generated bytes are parsed first so all compactors work from the final
34 * class-file model, including complete code attributes, stack maps and
35 * exception tables.
36 */
37 public class BytecodeCompactor {
38
39 /**
40 * Parses and compacts generated class bytes.
41 *
42 * @param classBytes generated class bytes
43 * @return compacted class bytes
44 */
45 public static byte[] transform(byte[] classBytes) {
46 return ClassFile.of().transformClass(ClassFile.of().parse(classBytes),
47 LocalsCompactor.instance().andThen(ClassTransform.transformingMethodBodies(
48 new ExceptionTableCompactor().andThen(
49 new BranchCompactor()))));
50 }
51
52 }