musl/include/sys/sysmacros.h
Rich Felker 9b732fe51b fix shifts possibly larger than type in major() macro
in theory this should not be an issue, since major() should only be
applied to type dev_t, which is 64-bit. however, it appears some
applications are not using dev_t but a smaller integer type (which
works on Linux because the kernel's dev_t is really only 32-bit). to
avoid the undefined behavior, do it as two shifts.
2013-06-29 13:57:13 -04:00

16 lines
394 B
C

#ifndef _SYS_SYSMACROS_H
#define _SYS_SYSMACROS_H
#define major(x) \
((unsigned)( (((x)>>31>>1) & 0xfffff000) | (((x)>>8) & 0x00000fff) ))
#define minor(x) \
((unsigned)( (((x)>>12) & 0xffffff00) | ((x) & 0x000000ff) ))
#define makedev(x,y) ( \
(((x)&0xfffff000ULL) << 32) | \
(((x)&0x00000fffULL) << 8) | \
(((y)&0xffffff00ULL) << 12) | \
(((y)&0x000000ffULL)) )
#endif