README

Karsk is direct port of ASM "a very small and fast Java bytecode manipulation framework".

This is highly experimental and very much work in progress at this moment. Any help is welcome!

Install

Preferred way to install framework is with composer:

composer require kambo/karsk

Basic usage

public class Helloworld {
    public static void main (String[] args) {
        System.out.println("Hello world!");
    }
}

<?php
use Kambo\Karsk\ClassWriter;
use Kambo\Karsk\Opcodes;

$cw = new ClassWriter(0);
$cw->visit(
    Opcodes::V1_8,
    Opcodes::ACC_PUBLIC,
    "Helloworld",
    null,
    "java/lang/Object",
    null
);

$mw = $cw->visitMethod(Opcodes::ACC_PUBLIC, "<init>", "()V", null, null);
$mw->visitVarInsn(Opcodes::ALOAD, 0);

$mw->visitMethodInsn(Opcodes::INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
$mw->visitInsn(Opcodes::RETURN_);
$mw->visitMaxs(1, 1);
$mw->visitEnd();

$mainMethod = $cw->visitMethod(
    (Opcodes::ACC_PUBLIC + Opcodes::ACC_STATIC),
    "main",
    "([Ljava/lang/String;)V",
    null,
    null
);
$mainMethod->visitFieldInsn(Opcodes::GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
$mainMethod->visitLdcInsn("Hello world!");

$mainMethod->visitMethodInsn(
    Opcodes::INVOKEVIRTUAL,
    "java/io/PrintStream",
    "println",
    "(Ljava/lang/String;)V",
    false
);
$mainMethod->visitInsn(Opcodes::RETURN_);
$mainMethod->visitMaxs(2, 2);
$mainMethod->visitEnd();

$code = $cw->toByteArray();

License

3-Clause BSD, https://opensource.org/licenses/BSD-3-Clause