uncompyle6 2.6.0

Python cross-version byte-code deparser

uncompyle6

A native Python cross-version Decompiler and Fragment Decompiler. Follows in the tradition of decompyle, uncompyle, and uncompyle2.

Introduction

uncompyle6 translates Python bytecode back into equivalent Python source code. It accepts bytecodes from Python version 2.5 to 3.5 or so. The code requires Python 2.6 or later and has been tested on Python running versions 2.6, 2.7, 3.2, 3.3, 3.4 and 3.5.

Why this?

There were a number of decompyle, uncompile, uncompyle2, uncompyle3 forks around. All of them come basically from the same code base, and almost all of them not maintained very well. This code pulls these together and addresses a number of open issues in those.

What makes this different from other CPython bytecode decompilers? Its ability to deparse just fragments and give source-code information around a given bytecode offset.

I use this to deparse fragments of code inside my trepan debuggers. For that, I need to record text fragments for all bytecode offsets (of interest). This purpose although largely compatible with the original intention is yet a little bit different. See this for more information.

The idea of Python fragment deparsing given an instruction offset can be used in showing stack traces or any program that wants to show a location in more detail than just a line number. It can be also used when source-code information does not exist and there is just bytecode information.

Installation

This uses setup.py, so it follows the standard Python routine:

pip install -r requirements.txt
pip install -r requirements-dev.txt
python setup.py install # may need sudo
# or if you have pyenv:
python setup.py develop

A GNU makefile is also provided so make install (possibly as root or sudo) will do the steps above.

Testing

make check

A GNU makefile has been added to smooth over setting running the right command, and running tests from fastest to slowest.

If you have remake installed, you can see the list of all tasks including tests via remake --tasks

Usage

Run

./bin/uncompyle6 -h

for usage help.

Known Bugs/Restrictions

Python 2 deparsing decompiles each and all the Python 2.7.10 and 2.7.11 installed packages I have on my system, more than 90% verify ok. Some of these failures may be bugs in the verification process. So as such, it is probably a little better than uncompyle2. Python 2.6 is catching up the versions of uncompyle2 that support 2.6 but is currently worse. Even less good is Python 2.5 bytecodes.

All of the Python 3.2-3.5 Python standard lib packages that I have installed on my system deparse. Each Python version has about 200 bytecode files. I’m not sure how well these verify though.

There are a few constructs that still need to be added to Python 3.5 Python 3.6 changes things drastically by using word codes rather than byte codes. So that will be yet another challenge

There is lots to do, so please dig in and help.

See Also

• https://github.com/zrax/pycdc : supports all versions of Python and is written in C++

• https://code.google.com/archive/p/unpyc3/ : supports Python 3.2 only

The above projects use a different decompiling technique what is used here.

The HISTORY file.