dnl From Gordon Matzigkeit.
dnl Test for the GNU C Library.
dnl FIXME: this should migrate into libit.

AC_DEFUN(AM_GLIBC,
  [
    AC_CACHE_CHECK(whether we are using the GNU C Library,
      ac_cv_gnu_library,
      [AC_EGREP_CPP([Thanks for using GNU],
	[
#include <features.h>
#ifdef __GNU_LIBRARY__
  Thanks for using GNU
#endif
	],
	ac_cv_gnu_library=yes,
	ac_cv_gnu_library=no)
      ]
    )
    AC_CACHE_CHECK(for version 2 of the GNU C Library,
      ac_cv_glibc,
      [AC_EGREP_CPP([Thanks for using GNU too],
	[
#include <features.h>
#ifdef __GLIBC__
  Thanks for using GNU too
#endif
	],
	ac_cv_glibc=yes, ac_cv_glibc=no)
      ]
    )
  ]
)