__glibc_clang_prereq  153 lib/cdefs.h    # if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0)		      \
__glibc_clang_prereq  644 lib/cdefs.h    #if __GNUC_PREREQ (4,8) || __glibc_clang_prereq (3,5)
__glibc_clang_prereq   59 lib/libc-config.h #ifndef __glibc_clang_prereq