Re: C++ exceptions catching through GDB-patched .eh_frame

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Wed, 17 Dec 2008 02:20:07 +0100, Tom Tromey wrote:
> Could we modify the personality functions to check a global, which we
> would then set before "next" (and clear after it)?  This global could
> refer to the frame we are "next"ing in, so the exception machinery
> could ignore uninteresting exceptions.  For interesting ones, it could
> call a function where we could put a breakpoint.  That would avoid the
> context switch per exception.
> 
> It wouldn't work with older versions of the compiler.  I'm not sure
> how much that matters.

Just that I fully agree it is a better choice - to patch __gxx_personality_v0.
A hook only for debugging - conditionalized something like _dl_debug_state().


> It would have some performance cost on all thrown exceptions.

Whole unwinding and __gxx_personality_v0() is already not a trivial task.


Thanks,
Jan