have_const.c

/*
 * have_const - Determine if we want or can support ANSI const
 *
 * Copyright (C) 1999,2021  Landon Curt Noll
 *
 * Calc is open software; you can redistribute it and/or modify it under
 * the terms of the version 2.1 of the GNU Lesser General Public License
 * as published by the Free Software Foundation.
 *
 * Calc 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 Lesser General
 * Public License for more details.
 *
 * A copy of version 2.1 of the GNU Lesser General Public License is
 * distributed with calc under the filename COPYING-LGPL.  You should have
 * received a copy with calc; if not, write to Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Under source code control:   1995/04/22 13:18:44
 * File existed as early as:    1995
 *
 * chongo <was here> /\oo/\     http://www.isthe.com/chongo/
 * Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
 */

/*
 * usage:
 *      have_const
 *
 * Not all compilers support const, so this may not compile on your system.
 *
 * This prog outputs several defines:
 *
 *      HAVE_CONST
 *              defined ==> OK to use const
 *              undefined ==> do not use const
 *
 *      CONST
 *              const ==> use const
 *              (nothing) ==> const not used
 */

#include <stdio.h>


#include "banned.h"     /* include after system header <> includes */


int
main(void)
{
#if defined(HAVE_NO_CONST)

        printf("#undef HAVE_CONST /* no */\n");
        printf("#undef CONST\n");
        printf("#define CONST /* no */\n");

#else /* HAVE_NO_CONST */

        const char * const str = "const";

        printf("#define HAVE_CONST /* yes */\n");
        printf("#undef CONST\n");
        printf("#define CONST %s /* yes */\n", str);

#endif /* HAVE_NO_CONST */

        /* exit(0); */
        return 0;
}