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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef CONTAINER_OF
#define CONTAINER_OF
#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
#define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#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
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