http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54487
--- Comment #23 from Markus Trippelsdorf <markus at trippelsdorf dot de> 2012-09-11 18:14:52 UTC --- gcc/gcov-io.h has: #if defined (HOST_HAS_F_SETLKW) #define GCOV_LOCKED 1 #else #define GCOV_LOCKED 0 #endif But HOST_HAS_F_SETLKW isn't defined anywhere else AFAICS: gcc % git grep HOST_HAS_F_SETLKW gcc/gcov-io.h:#if defined (HOST_HAS_F_SETLKW) gcc %