# Re: g++-cris - multiple call to virtual thunk across shared library causes SEGV

> Date: Sun, 21 Dec 2003 16:35:27 +0100
> From: owner-dev-etrax@xxxxxxx.com
(actually Tobias Schütte)
\begin{rant} Stupid mailing-list-from-munging removes original
email address and replaces it with owner-dev-etrax@xxxxxxx.
Painful and even worse than reply-to. \end{rant}

> some calls to virtual
> member functions causes a user programm to segfault, cuz execution jumps
> into the middle of nowhere. first of all, I thought that the libraries
> were too big for the devboard but after debugging with gdb-cris and
> analysing the member functions that causes the segfault, I noticed that
> a sequence of calls to virtual thunks is the problem.

Thank you very much for the very useful test-case and sorry for
the long delay.  It is indeed a thunk-related problem.  It will
be fixed in cris-dist-1.56.  I'll also track this as
<URL:http://gcc.gnu.org/PR14346> (with a simpler test-case),
aiming to fix it in the official gcc-3.3.4 too.  FWIW, generic
thunk code is rewritten in to-be-gcc-3.4 and to-be-gcc-3.5 to
use a slightly different construct that doesn't have this bug.

> mfg/regards
> Tobias

brgds, H-P