https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119388
--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> --- It would be better if you have an example of a false positive from the system headers rather than the current one you showed of a true positive. Yes there are a few in gcc bug system already dealing with -Wdangling-pointer, -Warray-bounds, and -Wstringop-overflow (and a few others) and many showed up in GCC 11 too. So it is not just one issue with -isystem and some of been there since the warning shows up.
