https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81081
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- The thing is that for backtrace_pcinfo the callback can be called multiple times. And IMNSHO the hack you want to do (fill in file/line in the backtrace_pcinfo call and function during backtrace_syminfo) is something you want to do only if backtrace_pcinfo calls the callback just once.
