/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 *

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 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

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 */

// Usage: jjs disassemble.js -- <.class-file-path>

// Simple .class disassembler that uses bundled ObjectWeb ASM

// classes in jdk8. WARNING: Bundled ObjectWeb ASM classes are

// not part of official jdk8 API. It can be changed/removed

// without notice. So, this script is brittle by design!

// This example demonstrates passing arguments to script

// from jjs command line, nio and ASM usage.

// classes used

var FileSystems = Java.type("java.nio.file.FileSystems");

var Files = Java.type("java.nio.file.Files");

var System = Java.type("java.lang.System");

var PrintWriter = Java.type("java.io.PrintWriter");

// WARNING: uses non-API classes of jdk8!

var ClassReader = Java.type("jdk.internal.org.objectweb.asm.ClassReader");

var TraceClassVisitor = Java.type("jdk.internal.org.objectweb.asm.util.TraceClassVisitor");

// convert file name to Path instance

function path(file) {

    return FileSystems.default.getPath(file);

}

// read all file content as a byte[]

function readAllBytes(file) {

    return Files.readAllBytes(path(file));

}

// disassemble .class byte[] and prints output to stdout

function disassemble(bytecode) {

    var pw = new PrintWriter(System.out);

    new ClassReader(bytecode).accept(new TraceClassVisitor(pw), 0);

}

// check for command line arg (for .class file name)

if (arguments.length == 0 || !arguments[0].endsWith('.class')) {

    print("Usage: jjs disassemble -- <.class file>");

    exit(1);

}

// disassemble the given .class file

disassemble(readAllBytes(arguments[0]));