Re: dlmopen and core dumps

[Carlos O'Donell <carlos at systemhalted dot org>]

On 12/19/2012 01:05 PM, Jan Kratochvil wrote:
> On Sat, 15 Dec 2012 01:20:03 +0100, Carlos O'Donell wrote:
> > Why not just run a generic program, or rather a python script?
>
> Python is needlessly expensive.  There does not exist only GDB, there exist
> other smaller tools examining external programs which can for example run on
> embedded targets.

Do you have examples of such tools that I can go look at?

> Python also has various compatibility issues, I doubt it is compatible with
> every platform GDB and other debugging tools are compatible with.

Could you please explain in more detail what you mean by python 
compatibility issues?

Note that it was not stated in the original requirements that the 
solution must be usable on every host that GDB and other tools support. 
Such a requirement is pretty broad and doesn't lend itself well to an 
initial implementation.

Even if that were the case I'm pretty sure I've seen python support for 
all GNU/Linux targets (and other non-Linux ones too) that gdb supports. 
Should we consider embedded systems there is the ability to use PyMite 
and Tiny Python on those systems. We might need to limit ourselves to 
Python 2.5.

> Why not to use DWARF expression code?

That's an interesting option, and if someone wants to flesh out a design 
for that *or* a python-based solution I'd be more than willing to review 
it and discuss it.

At present there appear to be three solutions:

(1) Investigate r_debug solution, it's incremental, and ugly, but we 
know it works.

(2) Investigate a python based solution, usable by gdb or other tools 
via a python interpreter.

(3) Investigate a DWARF based declarative solution.

We know (1) is not appealing.

At this point I think someone needs to investigate (2) and (3) in more 
detail. That someone is probably Gary Benson :-)

Does that make sense?

Cheers,
Carlos.