[linux-2.6-block.git] / include / linux / build_bug.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BUILD_BUG_H
#define _LINUX_BUILD_BUG_H

#include <linux/compiler.h>

#ifdef __CHECKER__
#define BUILD_BUG_ON_ZERO(e) (0)
#else /* __CHECKER__ */
/*
 * Force a compilation error if condition is true, but also produce a
 * result (of value 0 and type size_t), so the expression can be used
 * e.g. in a structure initializer (or where-ever else comma expressions
 * aren't permitted).
 */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
#endif /* __CHECKER__ */

/* Force a compilation error if a constant expression is not a power of 2 */
#define __BUILD_BUG_ON_NOT_POWER_OF_2(n)	\
	BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
#define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))

/*
 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
 * expression but avoids the generation of any code, even if that expression
 * has side-effects.
 */
#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))

/**
 * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
 *		      error message.
 * @condition: the condition which the compiler should know is false.
 *
 * See BUILD_BUG_ON for description.
 */
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)

/**
 * BUILD_BUG_ON - break compile if a condition is true.
 * @condition: the condition which the compiler should know is false.
 *
 * If you have some code which relies on certain constants being equal, or
 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
 * detect if someone changes it.
 */
#define BUILD_BUG_ON(condition) \
	BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)

/**
 * BUILD_BUG - break compile if used.
 *
 * If you have some code that you expect the compiler to eliminate at
 * build time, you should use BUILD_BUG to detect if it is
 * unexpectedly used.
 */
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")

#endif	/* _LINUX_BUILD_BUG_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
bc6245e5 IA	2	#ifndef _LINUX_BUILD_BUG_H
	3	#define _LINUX_BUILD_BUG_H
	4
	5	#include <linux/compiler.h>
	6
	7	#ifdef __CHECKER__
bc6245e5	8	#define BUILD_BUG_ON_ZERO(e) (0)
bc6245e5	9	#else /* __CHECKER__ */
bc6245e5 IA	10	/*
	11	* Force a compilation error if condition is true, but also produce a
	12	* result (of value 0 and type size_t), so the expression can be used
	13	* e.g. in a structure initializer (or where-ever else comma expressions
	14	* aren't permitted).
	15	*/
	16	#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
527edbc1 MY	17	#endif /* __CHECKER__ */
	18
	19	/* Force a compilation error if a constant expression is not a power of 2 */
	20	#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \
	21	BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
	22	#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
	23	BUILD_BUG_ON((n) == 0 \|\| (((n) & ((n) - 1)) != 0))
bc6245e5 IA	24
	25	/*
	26	* BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
	27	* expression but avoids the generation of any code, even if that expression
	28	* has side-effects.
	29	*/
	30	#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
	31
	32	/**
	33	* BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
	34	* error message.
	35	* @condition: the condition which the compiler should know is false.
	36	*
	37	* See BUILD_BUG_ON for description.
	38	*/
	39	#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
	40
	41	/**
	42	* BUILD_BUG_ON - break compile if a condition is true.
	43	* @condition: the condition which the compiler should know is false.
	44	*
	45	* If you have some code which relies on certain constants being equal, or
	46	* some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
	47	* detect if someone changes it.
bc6245e5	48	*/
bc6245e5 IA	49	#define BUILD_BUG_ON(condition) \
bc6245e5 IA	50	BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
bc6245e5 IA	51
	52	/**
	53	* BUILD_BUG - break compile if used.
	54	*
	55	* If you have some code that you expect the compiler to eliminate at
	56	* build time, you should use BUILD_BUG to detect if it is
	57	* unexpectedly used.
	58	*/
	59	#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
	60
bc6245e5	61	#endif /* _LINUX_BUILD_BUG_H */