/* 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_NOT_POWER_OF_2(n) (0)#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)#define BUILD_BUG_ON_ZERO(e) (0)#define BUILD_BUG_ON_INVALID(e) (0)#define BUILD_BUG_ON_MSG(cond, msg) (0)#define BUILD_BUG_ON(condition) (0)#define BUILD_BUG() (0)#else /* __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)) /* * 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)); })) /* * 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. * * The implementation uses gcc's reluctance to create a negative array, but gcc * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to * inline functions).  Luckily, in 4.3 they added the "error" function * attribute just for this type of case.  Thus, we use a negative sized array * (should always create an error on gcc versions older than 4.4) and then call * an undefined function with the error attribute (should always create an * error on gcc 4.3 and later).  If for some reason, neither creates a * compile-time error, we'll still have a link-time error, which is harder to * track down. */#ifndef __OPTIMIZE__#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))#else#define BUILD_BUG_ON(condition) \	BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)#endif /** * 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	/* __CHECKER__ */ #endif	/* _LINUX_BUILD_BUG_H */