include/sys/sysmacros.h

   1 /* Definitions of macros to access `dev_t' values.
   2    Copyright (C) 1996, 1997, 1999, 2003, 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _SYS_SYSMACROS_H
  20 #define _SYS_SYSMACROS_H        1
  21
  22 #include <features.h>
  23
  24 __BEGIN_DECLS
  25
  26 /* If the compiler does not know long long it is out of luck.  We are
  27    not going to hack weird hacks to support the dev_t representation
  28    they need.  */
  29
  30 __extension__
  31 extern unsigned int gnu_dev_major (unsigned long long int __dev)
  32      __THROW __attribute__ ((__const__));
  33 libc_hidden_proto(gnu_dev_major)
  34 __extension__
  35 extern unsigned int gnu_dev_minor (unsigned long long int __dev)
  36      __THROW __attribute__ ((__const__));
  37 libc_hidden_proto(gnu_dev_minor)
  38 __extension__
  39 extern unsigned long long int gnu_dev_makedev (unsigned int __major,
  40                                                         unsigned int __minor)
  41      __THROW __attribute__ ((__const__));
  42
  43 # ifdef __USE_EXTERN_INLINES
  44 __extension__ __extern_inline __attribute__ ((__const__)) unsigned int
  45 __NTH (gnu_dev_major (unsigned long long int __dev))
  46 {
  47   return ((__dev >> 8) & 0xfff) | ((unsigned int) (__dev >> 32) & ~0xfff);
  48 }
  49
  50 __extension__ __extern_inline __attribute__ ((__const__)) unsigned int
  51 __NTH (gnu_dev_minor (unsigned long long int __dev))
  52 {
  53   return (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff);
  54 }
  55
  56 __extension__ __extern_inline __attribute__ ((__const__)) unsigned long long int
  57 __NTH (gnu_dev_makedev (unsigned int __major, unsigned int __minor))
  58 {
  59   return ((__minor & 0xff) | ((__major & 0xfff) << 8)
  60           | (((unsigned long long int) (__minor & ~0xff)) << 12)
  61           | (((unsigned long long int) (__major & ~0xfff)) << 32));
  62 }
  63 # endif
  64 __END_DECLS
  65
  66 /* Access the functions with their traditional names.  */
  67 # define major(dev) gnu_dev_major (dev)
  68 # define minor(dev) gnu_dev_minor (dev)
  69 # define makedev(maj, min) gnu_dev_makedev (maj, min)
  70
  71 #endif /* sys/sysmacros.h */