CPython is the implementation of Python in C. It’s the first implementation, and still the main one that people mean when they talk about Python. It compiles .py files to .pyc files. .pyc files contain bytecodes. The CPython implementation also interprets those bytecodes. CPython is not written in C++, it is C. The compilation from … Read more
It looks like LuaDec itself was last updated for Lua 5.0.2. A new version targeting Lua 5.1.x bytecode has been released as LuaDec51. The wiki is always a good place to start looking for resources as mentioned by f3lix. The mailing list is also a good place to ask. Do note that it is relatively … Read more
If you run javap -v on the class file, you will see the debug information that is present in the file. It is worth compiling a simple test class with different -g option settings and looking at the results with javap. If, you need to know exactly how javap presents the information, it is it … Read more
In the java language, inner classes can access private members of their enclosing class. However, in Java bytecode, the concept of inner classes does not exist, and the private members are not accessible. To work around this, the compiler creates synthetic accessor methods in the outer class. I believe that is what you are seeing … Read more
Use the ord function http://ca.php.net/ord eg. <?php $var = “nÖ§9q1Fª£ˆæÓ§Œ_»—Ló]j”; for($i = 0; $i < strlen($var); $i++) { echo ord($var[$i]).”<br/>”; } ?>
Nothing decent with a UI, but you can use the Eclipse Bytecode Outline plugin to turn any Java class into ASM code, edit it, and produce the changed class. It’s probably the most painless way at the moment. http://asm.ow2.org/eclipse/index.html
Update: For sundry reasons I have started writing a Cross-Python-version assembler. See https://github.com/rocky/python-xasm. It is still in very early beta. See also bytecode. As far as I know there is no other currently-maintained Python assembler. PEAK’s Bytecode Disassembler was developed for Python 2.6, and later modified to support early Python 2.7. It is pretty cool … Read more
There are a lot of similarities between both implementations (and in my opinion: yes, they’re both “virtual machines”). For one thing, they’re both stack-based VM’s, with no notion of “registers” like we’re used to seeing in a modern CPU like the x86 or PowerPC. The evaluation of all expressions ((1 + 1) / 2) is … Read more
Here is a working “hello world” made with ObjectWeb ASM (a library which I recommend): package hello; import java.lang.reflect.Method; import org.objectweb.asm.ClassWriter; import org.objectweb.asm.Label; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; public class HelloWorldASM implements Opcodes { public static byte[] compile(String name) { ClassWriter cw = new ClassWriter(0); MethodVisitor mv; cw.visit(V1_6, ACC_PUBLIC + ACC_SUPER, “hello/HelloWorld”, null, “java/lang/Object”, null); cw.visitSource(“HelloWorld.java”, … Read more
The JVM (Java Virtual Machine) has an instruction set just like a real machine. The name given to this instruction set is Java Bytecode. It is described in the Java Virtual Machine Specification. Other languages are translated into a bytecode before execution, for example ruby and python. Java’s bytecode is at a fairly low level … Read more