On Mon, May 20, 2013 at 08:43:06AM -0700, Ian Lance Taylor wrote: > On Mon, May 20, 2013 at 7:31 AM, Basile Starynkevitch > <bas...@starynkevitch.net> wrote: > > > > Currently (for GCC 4.8 at least) when a plugin crashes (ie. SIGSEGV) > > libbacktrace is apparently not able > > to show backtrace information inside the plugin[s]. > > > > I believe that, at least on GNU/Linux wich has dladdr, it would be nice to > > extend libbacktrace > > to show backtrace information inside plugins (at least those compiled with > > -g). > > > > Is is reasonably feasible? I'm not familiar with libbacktrace, but (since > > MELT would be very happy with that) > > I might perhaps help.... > > That is actually supposed to work already. The code is in > libbacktrace/elf.c. It calls dl_iterate_phdr to find all the shared > libraries loaded into the process. I never tested it with dlopen so I > can certainly believe that it doesn't work, but I don't know why it > doesn't work.
Maybe I am wrong (I did not make any testcase for that). I very rarely have a SIGSEGV in MELT (because usually my own backtrace machinery works well), and when it happens it usually happens inside MELT generated C code which is dlopened (and not always compiled with -g) by the melt.so plugin. (so it is not a direct GCC plugin). Sorry for the noise. Cheers. -- Basile STARYNKEVITCH http://starynkevitch.net/Basile/ email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359 8, rue de la Faiencerie, 92340 Bourg La Reine, France *** opinions {are only mines, sont seulement les miennes} ***
