https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53769
--- Comment #17 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- (In reply to Jonathan Wakely from comment #16) > As explained above, this is not something that can be fixed in GCC. I'm wondering why this bug was marked as FIXED, then. This is misleading. > The macro depends on whether or not your C library provides <threads.h> which > GCC doesn't know. GCC could try to load it, just as if "#include <threads.h>" were used.