--- /dev/null
+dnl Special Autoconf macros for GNU Tar -*- autoconf -*-
+dnl Copyright (C) 2009 Free Software Foundation, Inc.
+dnl
+dnl GNU tar is free software; you can redistribute it and/or modify
+dnl it under the terms of the GNU General Public License as published by
+dnl the Free Software Foundation; either version 3, or (at your option)
+dnl any later version.
+dnl
+dnl GNU tar is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+dnl GNU General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License along
+dnl with GNU tar. If not, see <http://www.gnu.org/licenses/>.
+
+AC_DEFUN([TAR_COMPR_PROGRAM],[
+ m4_pushdef([tar_compr_define],translit($1,[a-z+-],[A-ZX_])[_PROGRAM])
+ m4_pushdef([tar_compr_var],[tar_cv_compressor_]translit($1,[+-],[x_]))
+ AC_ARG_WITH($1,
+ AC_HELP_STRING([--with-]$1[=PROG],
+ [use PROG as ]$1[ compressor program]),
+ [tar_compr_var=${withval}],
+ [tar_compr_var=m4_if($2,,$1,$2)])
+ AC_DEFINE_UNQUOTED(tar_compr_define, "$tar_compr_var",
+ [Define to the program name of ]$1[ compressor program])])