dnl CF_CHECK_EXTERN_DATA version: 3 updated: 2001/12/30 18:03:23
dnl --------------------
dnl Check for existence of external data in the current set of libraries.  If
dnl we can modify it, it's real enough.
dnl $1 = the name to check
dnl $2 = its type
AC_DEFUN([CF_CHECK_EXTERN_DATA],
[
AC_CACHE_CHECK(if external $1 exists, cf_cv_have_$1,[
    AC_TRY_LINK([
#undef $1
extern $2 $1;
],
    [$1 = 2],
    [cf_cv_have_$1=yes],
    [cf_cv_have_$1=no])
])

if test "$cf_cv_have_$1" = yes ; then
    CF_UPPER(cf_result,have_$1)
    AC_DEFINE_UNQUOTED($cf_result)
fi

])dnl
