On 9/4/07, Jose Flavio Aguilar Paulino <[EMAIL PROTECTED]> wrote:
>
> Well David, I think that this would be very important.
> Let's say your are building some kind of debugger (e.g. frysk) using
> libunwind. This raises a problem that in a x86_64 system you have
> several processes that are only x86, and your debugger would not be able
> to unwind this processes, so you would need to use to different compiled
> debuggers.
>
> I'm raising this problem because I'm working now in powerpc32 support,
> and that's very important because in a ppc64 server several processes
> are ppc32, and this will not change for a while, because they are
> intentionally 32 bits, in some cases, ppc32 binaries can be faster than
> ppc64. So it would be very important to libunwind64 be able to debug
> both ppc32 and ppc64, not only libunwind-ppc32 debug ppc32. And ppc32
> and ppc54 have different ABIs, but linux for ppc63 is able to deal with
> both.



Hi Jose, from your description above, the ppc situation is very similar to
x86.
So if we come up with a solution for x86, it should apply to ppc as well.

What do you all think of it?


A unit test (a variant of Gtest-bt.c ?) that shows the problem would be an
excellent starting point.

>From your description (and from what other frysk folks posted to the list),
it looks like you want to use:

* frysk64 to debug both 32 and 64 bit processes.

Current status is:

* fryst64 linked with libunwind works for 64 bit targets
* frysk64 linked with libunwind-xxx32 works for 32 bit targets
* frysk32 linked with libunwind works for 32 bit targets

But you want a single 64 bit debugger to link with two copies of libunwind
to
debug two different ABIs. Did I state the problem correctly?

I think the patches to make this case work should be broken into:

* patches needed (if any) to link 2 copies of libunwind (each with a
different ABI) into a binary
* patches to do cross ABI dwarf unwind info parsing. I expect these patches
to help with parsing unwind info for statically linked binaries as well.

Building libunwind twice with two different targets shouldn't be too
difficult?

 -Arun
_______________________________________________
Libunwind-devel mailing list
[email protected]
http://lists.nongnu.org/mailman/listinfo/libunwind-devel

Reply via email to