linuxdebug/include/linux/container_of.h

41 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_CONTAINER_OF_H
#define _LINUX_CONTAINER_OF_H
#include <linux/build_bug.h>
#include <linux/err.h>
#define typeof_member(T, m) typeof(((T*)0)->m)
/**
* container_of - cast a member of a structure out to the containing structure
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
*/
#define container_of(ptr, type, member) ({ \
void *__mptr = (void *)(ptr); \
static_assert(__same_type(*(ptr), ((type *)0)->member) || \
__same_type(*(ptr), void), \
"pointer type mismatch in container_of()"); \
((type *)(__mptr - offsetof(type, member))); })
/**
* container_of_safe - cast a member of a structure out to the containing structure
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
* If IS_ERR_OR_NULL(ptr), ptr is returned unchanged.
*/
#define container_of_safe(ptr, type, member) ({ \
void *__mptr = (void *)(ptr); \
static_assert(__same_type(*(ptr), ((type *)0)->member) || \
__same_type(*(ptr), void), \
"pointer type mismatch in container_of_safe()"); \
IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \
((type *)(__mptr - offsetof(type, member))); })
#endif /* _LINUX_CONTAINER_OF_H */