https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89864
--- Comment #26 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Erik Schnetter from comment #25) > > On Thu, Apr 4, 2019 at 5:43 AM iains at gcc dot gnu.org < > > gcc-bugzi...@gcc.gnu.org> wrote: > > _Atomic is used only in a single struct, which is marked "this structure > > should not be used outside the kernel", and protected by a "#ifdef > > __APPLE_API_UNSTABLE" (which unfortunately defaults to being defined). To > > my knowledge, no part of GCC will use this structure. Perhaps this provides an easier fix route: a) what causes __APPLE_API_UNSTABLE to be defined? b) what uses __APPLE_API_UNSTABLE? c) could we undef it locally to solve the issue? - GCC is not currently claiming to be capable of building the kernel (I've not tried building any kernel > darwin9 with GCC).
