http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61106
--- Comment #3 from Matthias Klose <doko at gcc dot gnu.org> --- this leads to: if (!opts_set->x_warn_unused_but_set_variable) handle_generated_option (opts, opts_set, OPT_Wunused_but_set_variable, NULL, (), lang_mask, kind, loc, handlers, dc); and lets the compiler complain about: options.c:11506:71: error: expected primary-expression before ')' token OPT_Wunused_but_set_variable, NULL, (), ^