#ifndef _LINUX_BUILD_BUG_H #define _LINUX_BUILD_BUG_H #include #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 int), 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) ((int)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") /** * static_assert - check integer constant expression at build time * * static_assert() is a wrapper for the C11 _Static_assert, with a * little macro magic to make the message optional (defaulting to the * stringification of the tested expression). * * Contrary to BUILD_BUG_ON(), static_assert() can be used at global * scope, but requires the expression to be an integer constant * expression (i.e., it is not enough that __builtin_constant_p() is * true for expr). * * Also note that BUILD_BUG_ON() fails the build if the condition is * true, while static_assert() fails the build if the expression is * false. */ #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) #define __static_assert(expr, msg, ...) _Static_assert(expr, msg) #endif /* _LINUX_BUILD_BUG_H */