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

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

[Sergei Golubchik]

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

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

[Simon Marchi]

On 2017-06-19 11:03, Sergei Golubchik wrote:
> 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

That's indeed very nice, I didn't know about it.  The alternative of 
these lines using only built-in gdb features would be to write a small 
while loop, I guess.  So I can see how this can be convenient.

> 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.

I really like using an annotation for declaring a pretty printer.  I 
wonder if we could (legally-wise and technically-wise) steal that idea 
:).

Simon

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

[Sergei Golubchik]

Hi, Simon!

> > 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.
> 
> I really like using an annotation for declaring a pretty printer.  I 
> wonder if we could (legally-wise and technically-wise) steal that idea 
> :).

For upstream gdb? As far as I'm concerned - yes, on both points :)

Regards,
Sergei
Chief Architect MariaDB
and security@mariadb.org