linux-stable/include/linux/container_of.h
Andy Shevchenko 2b8e353376 container_of: Update header inclusions
The commit 848dba781f ("container_of: remove container_of_safe()")
removed the code that uses err.h. Replace the inclusion by stddef.h
which provides offsetof() definition which is still in use.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230130111746.59830-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-31 12:44:20 +01:00

38 lines
1.3 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/stddef.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.
*
* WARNING: any const qualifier of @ptr is lost.
*/
#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_const - cast a member of a structure out to the containing
* structure and preserve the const-ness of the pointer
* @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_const(ptr, type, member) \
_Generic(ptr, \
const typeof(*(ptr)) *: ((const type *)container_of(ptr, type, member)),\
default: ((type *)container_of(ptr, type, member)) \
)
#endif /* _LINUX_CONTAINER_OF_H */