https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65467
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> --- This is indeed just a big hammer approach. The OpenMP standard only supports C up to C99 and C++ up to C++98 at this point, for _Atomic it is non-trivial to figure out how it should behave with different clauses etc. But indeed, it would be better to just complain only if _Atomic is somehow used in OpenMP regions, but that would require first writing testcases for all the different possibilities where _Atomic could appear.
