sysdeps/unix/sysv/linux/sys/sysmacros.h

   1 /* Definitions of macros to access `dev_t' values.
   2    Copyright (C) 1996-2013 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 /* If the compiler does not know long long it is out of luck.  We are
  25    not going to hack weird hacks to support the dev_t representation
  26    they need.  */
  27 #ifdef __GLIBC_HAVE_LONG_LONG
  28 __BEGIN_DECLS
  29
  30 __extension__
  31 extern unsigned int gnu_dev_major (unsigned long long int __dev)
  32      __THROW __attribute_const__;
  33 __extension__
  34 extern unsigned int gnu_dev_minor (unsigned long long int __dev)
  35      __THROW __attribute_const__;
  36 __extension__
  37 extern unsigned long long int gnu_dev_makedev (unsigned int __major,
  38                                                unsigned int __minor)
  39      __THROW __attribute_const__;
  40
  41 # if defined __GNUC__ && __GNUC__ >= 2 && defined __USE_EXTERN_INLINES
  42 __extension__ __extern_inline __attribute_const__ unsigned int
  43 __NTH (gnu_dev_major (unsigned long long int __dev))
  44 {
  45   return ((__dev >> 8) & 0xfff) | ((unsigned int) (__dev >> 32) & ~0xfff);
  46 }
  47
  48 __extension__ __extern_inline __attribute_const__ unsigned int
  49 __NTH (gnu_dev_minor (unsigned long long int __dev))
  50 {
  51   return (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff);
  52 }
  53
  54 __extension__ __extern_inline __attribute_const__ unsigned long long int
  55 __NTH (gnu_dev_makedev (unsigned int __major, unsigned int __minor))
  56 {
  57   return ((__minor & 0xff) | ((__major & 0xfff) << 8)
  58           | (((unsigned long long int) (__minor & ~0xff)) << 12)
  59           | (((unsigned long long int) (__major & ~0xfff)) << 32));
  60 }
  61 # endif
  62 __END_DECLS
  63
  64 /* Access the functions with their traditional names.  */
  65 # define major(dev) gnu_dev_major (dev)
  66 # define minor(dev) gnu_dev_minor (dev)
  67 # define makedev(maj, min) gnu_dev_makedev (maj, min)
  68 #endif
  69
  70 #endif /* sys/sysmacros.h */