NetBSDのcontainer_of()マクロでvoid *を特別扱いする

container_of.h

#if defined(__COVERITY__) || defined(__LGTM_BOT__)
#define __validate_container_of(PTR, TYPE, FIELD) 0
#define __validate_const_container_of(PTR, TYPE, FIELD) 0
#else
#define __validate_container_of(PTR, TYPE, FIELD)			\
    (0 * sizeof(__builtin_choose_expr(					\
    __builtin_types_compatible_p(typeof(PTR), void *),			\
    (const char *)(PTR), (PTR)) -					\
    __builtin_choose_expr(__builtin_types_compatible_p(typeof(PTR),	\
    void *), (const char *)&(((TYPE *)(((char *)(PTR)) -		\
    offsetof(TYPE, FIELD)))->FIELD),					\
    &(((TYPE *)(((char *)(PTR)) - offsetof(TYPE, FIELD)))->FIELD))))
#define __validate_const_container_of(PTR, TYPE, FIELD)			\
    (0 * sizeof(__builtin_choose_expr(					\
    __builtin_types_compatible_p(typeof(PTR), void *),			\
    (const char *)(PTR), (PTR)) -					\
    __builtin_choose_expr(__builtin_types_compatible_p(typeof(PTR),	\
    void *), (const char *)&(((const TYPE *)(((const char *)(PTR)) -	\
    offsetof(TYPE, FIELD)))->FIELD),					\
    &(((const TYPE *)(((const char *)(PTR)) - offsetof(TYPE, FIELD)))->FIELD))))
#endif

#define container_of(PTR, TYPE, FIELD)					\
    ((TYPE *)(((char *)(PTR)) - offsetof(TYPE, FIELD))			\
	+ __validate_container_of(PTR, TYPE, FIELD))
#define const_container_of(PTR, TYPE, FIELD)				\
    ((const TYPE *)(((const char *)(PTR)) - offsetof(TYPE, FIELD))	\
	+ __validate_const_container_of(PTR, TYPE, FIELD))