Duel reloaded: Duel.py (and a PrettyPrinter decorator)

Hi,

If you've never heard about Duel - it's an insanely cool data
exploration language for gdb. Specifically designed to print out complex
data structures in one command. Created as a public domain patch for gdb
in 1993, but never got accepted for licensing reasons.

Still, Duel is super-convenient, for example, to print the whole linked
list one writes just

  (gdb) dl head-->next->val

and to print field 'name' of every element in an array of structures,
one writes

  (gdb) dl arr[..100].name

I've recently rewritten it in Python, so it doesn't need to be compiled
with gdb anymore, one can load it run-time (e.g. from .gdbinit).

Here it is: https://github.com/vuvova/gdb-tools

This repository also includes a helper to simplify writing pretty
printers. It removes all the boilerplate code that gdb requires, you
only need to write the value-to-string function itself.

Enjoy!

Regards,
Sergei