Files
scoutfs/utils/src/util.h
Zach Brown f86ce74ffd Add BITS_PER_LONG define
Signed-off-by: Zach Brown <zab@versity.com>
2017-04-18 14:20:43 -07:00

79 lines
1.7 KiB
C

#ifndef _UTIL_H_
#define _UTIL_H_
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
/*
* Generate build warnings if the condition is false but generate no
* code at run time if it's true.
*/
#define build_assert(cond) ((void)sizeof(char[1 - 2*!(cond)]))
#define min(a, b) \
({ \
__typeof__(a) _a = (a); \
__typeof__(b) _b = (b); \
\
_a < _b ? _a : _b; \
})
#define max(a, b) \
({ \
__typeof__(a) _a = (a); \
__typeof__(b) _b = (b); \
\
_a > _b ? _a : _b; \
})
#define swap(a, b) \
do { \
__typeof__(a) _t = (a); \
(a) = (b); \
(b) = (_t); \
} while (0)
#define array_size(arr) (sizeof(arr) / sizeof(arr[0]))
#define __packed __attribute__((packed))
/*
* Round the 'a' value up to the next 'b' power of two boundary. It
* casts the mask to the value type before masking to avoid truncation
* problems.
*/
#define round_up(a, b) \
({ \
__typeof__(a) _b = (b); \
\
((a) + _b - 1) & ~(_b - 1); \
})
#define DIV_ROUND_UP(x, y) (((x) + (y) - 1) / (y))
#define ALIGN(x, y) (((x) + (y) - 1) & ~((y) - 1))
#ifndef offsetof
#define offsetof(type, memb) ((unsigned long)&((type *)0)->memb)
#endif
#define container_of(ptr, type, memb) \
((type *)((void *)(ptr) - offsetof(type, memb)))
#define BITS_PER_LONG (sizeof(long) * 8)
/*
* return -1,0,+1 based on the memcmp comparison of the minimum of their
* two lengths. If their min shared bytes are equal but the lengths
* are not then the larger length is considered greater.
*/
static inline int memcmp_lens(const void *a, int a_len,
const void *b, int b_len)
{
unsigned int len = min(a_len, b_len);
return memcmp(a, b, len) ?: a_len - b_len;
}
#endif