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   1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
   2 /*
   3  * Copyright (c) 1993, 1994, 1995, 1996, 1997
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the Computer Systems
  17  *      Engineering Group at Lawrence Berkeley Laboratory.
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  19  *    to endorse or promote products derived from this software without
  20  *    specific prior written permission.
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  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef varattrs_h
  36 #define varattrs_h
  37
  38 #include "compiler-tests.h"
  39
  40 /*
  41  * Attributes to apply to variables, using various compiler-specific
  42  * extensions.
  43  */
  44
  45 #if __has_attribute(unused) \
  46     || ND_IS_AT_LEAST_GNUC_VERSION(2,0)
  47   /*
  48    * Compiler with support for __attribute__((unused)), or GCC 2.0 and
  49    * later, so it supports __attribute__((unused)).
  50    */
  51   #define _U_ __attribute__((unused))
  52 #else
  53   /*
  54    * We don't know of any way to mark a variable as unused.
  55    */
  56   #define _U_
  57 #endif
  58
  59 #endif