include/linux/typecheck.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef TYPECHECK_H_INCLUDED
0003 #define TYPECHECK_H_INCLUDED
0004
0005 /*
0006  * Check at compile time that something is of a particular type.
0007  * Always evaluates to 1 so you may use it easily in comparisons.
0008  */
0009 #define typecheck(type,x) \
0010 ({  type __dummy; \
0011     typeof(x) __dummy2; \
0012     (void)(&__dummy == &__dummy2); \
0013     1; \
0014 })
0015
0016 /*
0017  * Check at compile time that 'function' is a certain type, or is a pointer
0018  * to that type (needs to use typedef for the function type.)
0019  */
0020 #define typecheck_fn(type,function) \
0021 ({  typeof(type) __tmp = function; \
0022     (void)__tmp; \
0023 })
0024
0025 /*
0026  * Check at compile time that something is a pointer type.
0027  */
0028 #define typecheck_pointer(x) \
0029 ({  typeof(x) __dummy; \
0030     (void)sizeof(*__dummy); \
0031     1; \
0032 })
0033
0034 #endif      /* TYPECHECK_H_INCLUDED */