# Now source each add-on's configure fragment.
  # The fragments can use $srcdir/$libc_add_on to find themselves,
  # and test $add_ons_automatic to see if they were explicitly requested.
  # A fragment can clear (or even change) $libc_add_on to affect
  # whether it goes into the list to be actually used in the build.
  use_add_ons=
  for libc_add_on in $add_ons; do
    # Test whether such a directory really exists.
    # It can be absolute, or relative to $srcdir, or relative to the build dir.
    case "$libc_add_on" in
    /*)
      libc_add_on_srcdir=$libc_add_on
      ;;
    *)
      test -d "$srcdir/$libc_add_on" || {
	if test -d "$libc_add_on"; then
	  libc_add_on="`pwd`/$libc_add_on"
	else
	  as_fn_error $? "add-on directory \"$libc_add_on\" does not exist" "$LINENO" 5
	fi
      }
      libc_add_on_srcdir=$srcdir/$libc_add_on
      ;;
    esac

    libc_add_on_frag=$libc_add_on_srcdir/configure 
    libc_add_on_canonical=
    libc_add_on_config_subdirs=
    if test -r "$libc_add_on_frag"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: running configure fragment for add-on $libc_add_on" >&5
$as_echo "$as_me: running configure fragment for add-on $libc_add_on" >&6;}
      libc_add_on_canonical=unknown
      libc_add_on_subdirs=
      . "$libc_add_on_frag"
      test -z "$libc_add_on" || {
	configured_add_ons="$configured_add_ons $libc_add_on"
	if test "x$libc_add_on_canonical" = xunknown; then
	  as_fn_error $? "fragment must set \$libc_add_on_canonical" "$LINENO" 5
	fi
	for d in $libc_add_on_subdirs; do
	  case "$libc_add_on" in
	  /*) subdir_srcdir="$libc_add_on" ;;
	  *) subdir_srcdir="\$(..)$libc_add_on" ;;
	  esac
	  case "$d" in
	  .)
	    d="${libc_add_on_canonical:-$libc_add_on}"
	    ;;
	  /*)
	    subdir_srcdir="$d"
	    ;;
	  *)
	    subdir_srcdir="$subdir_srcdir/$d"
	    ;;
	  esac
	  d=`echo "$d" | sed 's@/*$@@;s@^.*/@@'`
	  add_on_subdirs="$add_on_subdirs $d"
	  test "$subdir_srcdir" = "\$(..)$d" || config_vars="$config_vars
$d-srcdir = $subdir_srcdir"
	done
	for d in $libc_add_on_config_subdirs; do
	  case "$d" in
	  /*) as_fn_error $? "fragment uses absolute path in \$libc_add_on_config_subdirs" "$LINENO" 5 ;;
	  esac
	  if test ! -d "$libc_add_on_srcdir/$d"; then
	    as_fn_error $? "fragment wants to configure missing directory $d" "$LINENO" 5
	  fi
	  case "$libc_add_on" in
	  /*) as_fn_error $? "relative path required for add-on using \$libc_add_on_config_subdirs" "$LINENO" 5 ;;
	  esac
	  subdirs="$subdirs $libc_add_on/$d"
	done
      }
    fi
    if test -n "$libc_add_on"; then
      if frags=`ls -d $libc_add_on_srcdir/sysdeps/*/preconfigure 2> /dev/null`
then
  { $as_echo "$as_me:${as_lineno-$LINENO}: checking add-on $libc_add_on for preconfigure fragments" >&5
$as_echo_n "checking add-on $libc_add_on for preconfigure fragments... " >&6; }
  for frag in $frags; do
    name=`echo "$frag" | sed 's@/[^/]*$@@;s@^.*/@@'`
    echo $ECHO_N "$name $ECHO_C" >&6
    . "$frag"
  done
  { $as_echo "$as_me:${as_lineno-$LINENO}: result: " >&5
$as_echo "" >&6; }
fi
      use_add_ons="$use_add_ons $libc_add_on"
      add_ons_pfx="$add_ons_pfx $libc_add_on/"
      test -z "$libc_add_on_canonical" ||
      add_ons_sfx="$add_ons_sfx /$libc_add_on_canonical"
    fi
  done
  # Use echo to strip excess whitespace.
  add_ons="`echo $use_add_ons`"
fi