typecheck.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef TYPECHECK_H_INCLUDED
 3#define TYPECHECK_H_INCLUDED
 4
 5/*
 6 * Check at compile time that something is of a particular type.
 7 * Always evaluates to 1 so you may use it easily in comparisons.
 8 */
 9#define typecheck(type,x) \
10({	type __dummy; \
11	typeof(x) __dummy2; \
12	(void)(&__dummy == &__dummy2); \
13	1; \
14})
15
16/*
17 * Check at compile time that 'function' is a certain type, or is a pointer
18 * to that type (needs to use typedef for the function type.)
19 */
20#define typecheck_fn(type,function) \
21({	typeof(type) __tmp = function; \
22	(void)__tmp; \
23})
24
25/*
26 * Check at compile time that something is a pointer type.
27 */
28#define typecheck_pointer(x) \
29({	typeof(x) __dummy; \
30	(void)sizeof(*__dummy); \
31	1; \
32})
33
34#endif		/* TYPECHECK_H_INCLUDED */