Current File : //usr/include/x86_64-linux-gnu/bits/sysmacros.h
/* Definitions of macros to access `dev_t' values.
Copyright (C) 1996-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _BITS_SYSMACROS_H
#define _BITS_SYSMACROS_H 1
#ifndef _SYS_SYSMACROS_H
# error "Never include <bits/sysmacros.h> directly; use <sys/sysmacros.h> instead."
#endif
/* dev_t in glibc is a 64-bit quantity, with 32-bit major and minor numbers.
Our default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of
the major number and m is a hex digit of the minor number. This is
downward compatible with legacy systems where dev_t is 16 bits wide,
encoded as MMmm. It is also downward compatible with the Linux kernel,
which (as of 2016) uses 32-bit dev_t, encoded as mmmM MMmm.
Systems that use an incompatible encoding for dev_t should override this
file in the appropriate sysdeps subdirectory. */
#define __SYSMACROS_DECLARE_MAJOR(DECL_TEMPL) \
DECL_TEMPL(unsigned int, major, (__dev_t __dev))
#define __SYSMACROS_DEFINE_MAJOR(DECL_TEMPL) \
__SYSMACROS_DECLARE_MAJOR (DECL_TEMPL) \
{ \
unsigned int __major; \
__major = ((__dev & (__dev_t) 0x00000000000fff00u) >> 8); \
__major |= ((__dev & (__dev_t) 0xfffff00000000000u) >> 32); \
return __major; \
}
#define __SYSMACROS_DECLARE_MINOR(DECL_TEMPL) \
DECL_TEMPL(unsigned int, minor, (__dev_t __dev))
#define __SYSMACROS_DEFINE_MINOR(DECL_TEMPL) \
__SYSMACROS_DECLARE_MINOR (DECL_TEMPL) \
{ \
unsigned int __minor; \
__minor = ((__dev & (__dev_t) 0x00000000000000ffu) >> 0); \
__minor |= ((__dev & (__dev_t) 0x00000ffffff00000u) >> 12); \
return __minor; \
}
#define __SYSMACROS_DECLARE_MAKEDEV(DECL_TEMPL) \
DECL_TEMPL(__dev_t, makedev, (unsigned int __major, unsigned int __minor))
#define __SYSMACROS_DEFINE_MAKEDEV(DECL_TEMPL) \
__SYSMACROS_DECLARE_MAKEDEV (DECL_TEMPL) \
{ \
__dev_t __dev; \
__dev = (((__dev_t) (__major & 0x00000fffu)) << 8); \
__dev |= (((__dev_t) (__major & 0xfffff000u)) << 32); \
__dev |= (((__dev_t) (__minor & 0x000000ffu)) << 0); \
__dev |= (((__dev_t) (__minor & 0xffffff00u)) << 12); \
return __dev; \
}
#endif /* bits/sysmacros.h */
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