/*
  Copyright 2014 Red Hat, Inc.

  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; see the file COPYING.  If not, write to the
  Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  MA 02110-1301 USA
*/

#ifndef CONFIG_H
#define CONFIG_H

/* heavily inspired from
   http://gustedt.wordpress.com/2010/06/08/detect-empty-macro-arguments/
 */
#define _HAS_COMMA(_0, _1, _2, ...) _2
#define HAS_COMMA(...)              _HAS_COMMA(__VA_ARGS__, 1, 0)
#define _TRIGGER_PAREN(...)         ,
#define IS_EMPTY(...)                HAS_COMMA(_TRIGGER_PAREN __VA_ARGS__ ())

/* https://gcc.gnu.org/onlinedocs/cpp/Stringification.html */
#define _STRINGIFY(arg)             #arg
#define STRINGIFY(arg)              _STRINGIFY(arg)


/* following constructions say: define macro iff not defined yet + non-empty */

#ifndef RA_METADATA_DIR
#  define RA_METADATA_DIR_DEF       @RA_METADATA_DIR@
#  if !IS_EMPTY(RA_METADATA_DIR_DEF)
#    define RA_METADATA_DIR         STRINGIFY(RA_METADATA_DIR_DEF)
#  endif
#endif

#ifndef RA_METADATA_EXT
#  define RA_METADATA_EXT_DEF       @RA_METADATA_EXT@
#  if !IS_EMPTY(RA_METADATA_EXT_DEF)
#    define RA_METADATA_EXT         STRINGIFY(RA_METADATA_EXT_DEF)
#  endif
#endif

#endif