modernc.org/cc@v1.0.1/v2/headers/linux_386/usr/include/i386-linux-gnu/bits/sysmacros.h (about)

     1  /* Definitions of macros to access `dev_t' values.
     2     Copyright (C) 1996-2018 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 _BITS_SYSMACROS_H
    20  #define _BITS_SYSMACROS_H 1
    21  
    22  #ifndef _SYS_SYSMACROS_H
    23  # error "Never include <bits/sysmacros.h> directly; use <sys/sysmacros.h> instead."
    24  #endif
    25  
    26  /* dev_t in glibc is a 64-bit quantity, with 32-bit major and minor numbers.
    27     Our default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of
    28     the major number and m is a hex digit of the minor number.  This is
    29     downward compatible with legacy systems where dev_t is 16 bits wide,
    30     encoded as MMmm.  It is also downward compatible with the Linux kernel,
    31     which (as of 2016) uses 32-bit dev_t, encoded as mmmM MMmm.
    32  
    33     Systems that use an incompatible encoding for dev_t should override this
    34     file in the appropriate sysdeps subdirectory.  */
    35  
    36  #define __SYSMACROS_DECLARE_MAJOR(DECL_TEMPL)			\
    37    DECL_TEMPL(unsigned int, major, (__dev_t __dev))
    38  
    39  #define __SYSMACROS_DEFINE_MAJOR(DECL_TEMPL)			\
    40    __SYSMACROS_DECLARE_MAJOR (DECL_TEMPL)			\
    41    {								\
    42      unsigned int __major;					\
    43      __major  = ((__dev & (__dev_t) 0x00000000000fff00u) >>  8); \
    44      __major |= ((__dev & (__dev_t) 0xfffff00000000000u) >> 32); \
    45      return __major;						\
    46    }
    47  
    48  #define __SYSMACROS_DECLARE_MINOR(DECL_TEMPL)			\
    49    DECL_TEMPL(unsigned int, minor, (__dev_t __dev))
    50  
    51  #define __SYSMACROS_DEFINE_MINOR(DECL_TEMPL)			\
    52    __SYSMACROS_DECLARE_MINOR (DECL_TEMPL)			\
    53    {								\
    54      unsigned int __minor;					\
    55      __minor  = ((__dev & (__dev_t) 0x00000000000000ffu) >>  0); \
    56      __minor |= ((__dev & (__dev_t) 0x00000ffffff00000u) >> 12); \
    57      return __minor;						\
    58    }
    59  
    60  #define __SYSMACROS_DECLARE_MAKEDEV(DECL_TEMPL)			\
    61    DECL_TEMPL(__dev_t, makedev, (unsigned int __major, unsigned int __minor))
    62  
    63  #define __SYSMACROS_DEFINE_MAKEDEV(DECL_TEMPL)			\
    64    __SYSMACROS_DECLARE_MAKEDEV (DECL_TEMPL)			\
    65    {								\
    66      __dev_t __dev;						\
    67      __dev  = (((__dev_t) (__major & 0x00000fffu)) <<  8);	\
    68      __dev |= (((__dev_t) (__major & 0xfffff000u)) << 32);	\
    69      __dev |= (((__dev_t) (__minor & 0x000000ffu)) <<  0);	\
    70      __dev |= (((__dev_t) (__minor & 0xffffff00u)) << 12);	\
    71      return __dev;						\
    72    }
    73  
    74  #endif				/* bits/sysmacros.h */