_GNU_SOURCE      4464 ext/ripper/ripper.c #  if defined __GLIBC__ && defined _STRING_H && defined _GNU_SOURCE
_GNU_SOURCE        47 ext/tk/tkutil/tkutil.c #if defined(HAVE_STRNDUP) && !defined(_GNU_SOURCE)
_GNU_SOURCE      4467 parse.c        #  if defined __GLIBC__ && defined _STRING_H && defined _GNU_SOURCE