1 /* Definitions of macros to access `dev_t' values.
2 Copyright (C) 1996, 1997, 1999, 2003, 2004, 2007
3 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
20
21 #ifndef _SYS_SYSMACROS_H
22 #define _SYS_SYSMACROS_H 1
23
24 #include <features.h>
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 #ifdef __GLIBC_HAVE_LONG_LONG
30 __extension__
31 extern unsigned int gnu_dev_major (unsigned long long int __dev)
32 __THROW;
33 __extension__
34 extern unsigned int gnu_dev_minor (unsigned long long int __dev)
35 __THROW;
36 __extension__
37 extern unsigned long long int gnu_dev_makedev (unsigned int __major,
38 unsigned int __minor)
39 __THROW;
40
41 # if defined __GNUC__ && __GNUC__ >= 2 && defined __USE_EXTERN_INLINES
42 __extension__ __extern_inline 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 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 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
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 */
71