dnl Copied from Audacity 1.3.10 which itself is licensed under the GPL v2 or

dnl any later version

dnl Function to configure a sub-library now, because we need to know the result

dnl of the configuration now in order to take decisions.

dnl We don't worry about whether the configuration worked or not - it is

dnl assumed that the next thing after this will be a package-specific check to

dnl see if the package is actually available. (Hint: use pkg-config and

dnl -uninstalled.pc files if available).

dnl code based on a simplification of _AC_OUTPUT_SUBDIRS in 

dnl /usr/share/autoconf/autoconf/status.m4 which implements part of 

dnl AC_CONFIG_SUBDIRS

AC_DEFUN([AX_CONFIG_DIR],

[AC_REQUIRE([AC_DISABLE_OPTION_CHECKING])]

[m4_append([_AC_LIST_SUBDIRS], [$1], [])]

[

  # Remove --cache-file and --srcdir arguments so they do not pile up.

  ax_sub_configure_args=

  ax_prev=

  eval "set x $ac_configure_args"

  shift

  for ax_arg

  do

    if test -n "$ax_prev"; then

      ax_prev=

      continue

    fi

    case $ax_arg in

    -cache-file | --cache-file | --cache-fil | --cache-fi \

    | --cache-f | --cache- | --cache | --cach | --cac | --ca | --c)

      ax_prev=cache_file ;;

    -cache-file=* | --cache-file=* | --cache-fil=* | --cache-fi=* \

    | --cache-f=* | --cache-=* | --cache=* | --cach=* | --cac=* | --ca=* \

    | --c=*)

      ;;

    --config-cache | -C)

      ;;

    -srcdir | --srcdir | --srcdi | --srcd | --src | --sr)

      ax_prev=srcdir ;;

    -srcdir=* | --srcdir=* | --srcdi=* | --srcd=* | --src=* | --sr=*)

      ;;

    -prefix | --prefix | --prefi | --pref | --pre | --pr | --p)

      ax_prev=prefix ;;

    -prefix=* | --prefix=* | --prefi=* | --pref=* | --pre=* | --pr=* | --p=*)

      ;;

    *)

      case $ax_arg in

      *\'*) ax_arg=`echo "$ax_arg" | sed "s/'/'\\\\\\\\''/g"` ;;

      esac

      ax_sub_configure_args="$ax_sub_configure_args '$ax_arg'" ;;

    esac

  done

  # Always prepend --prefix to ensure using the same prefix

  # in subdir configurations.

  ax_arg="--prefix=$prefix"

  case $ax_arg in

  *\'*) ax_arg=`echo "$ax_arg" | sed "s/'/'\\\\\\\\''/g"` ;;

  esac

  ax_sub_configure_args="'$ax_arg' $ax_sub_configure_args"

  # Pass --silent

  if test "$silent" = yes; then

    ax_sub_configure_args="--silent $ax_sub_configure_args"

  fi

  ax_popdir=`pwd`

  AC_MSG_NOTICE([Configuring sources in $1])

  dnl for out-of-place builds srcdir and builddir will be different, and

  dnl builddir may not exist, so we must create it

  AS_MKDIR_P(["$1"])

  dnl and also set the variables. As this isn't autoconf, the following may be

  dnl risky:

  _AC_SRCDIRS(["$1"])

  cd "$1"

  # Check for guested configure; otherwise get Cygnus style configure.

  if test -f "configure.gnu"; then

    ax_sub_configure=$ac_srcdir/configure.gnu

  elif test -f "$ac_srcdir/configure"; then

    ax_sub_configure=$ac_srcdir/configure

  elif test -f "$ac_srcdir/configure.in"; then

    # This should be Cygnus configure.

	ax_sub_configure=$ac_aux_dir/configure

  else

    AC_MSG_WARN([no configuration information is in $1])

    ax_sub_configure=

  fi

  # The recursion is here.

  if test -n "$ax_sub_configure"; then

    # Make the cache file name correct relative to the subdirectory.

    case $cache_file in

    [[\\/]]* | ?:[[\\/]]* ) ax_sub_cache_file=$cache_file ;;

    *) # Relative name.

	ax_sub_cache_file=$ac_top_build_prefix$cache_file ;;

    esac

    AC_MSG_NOTICE([running $SHELL $ax_sub_configure $ax_sub_configure_args --cache-file=$ax_sub_cache_file --srcdir=$ac_srcdir])

    # The eval makes quoting arguments work.

    eval "\$SHELL \"\$ax_sub_configure\" $ax_sub_configure_args \

	   --cache-file=\"\$ax_sub_cache_file\" --srcdir=\"\$ax_srcdir\""

  fi

  cd "$ax_popdir"

  AC_MSG_NOTICE([Done configuring in $1])

])