diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index dfadc96e9d63..2f4079175afb 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -29,6 +29,7 @@ the kernel context */ #define __cold __attribute__((__cold__)) +#define __linktime_error(message) __attribute__((__error__(message))) #if __GNUC_MINOR__ >= 5 /* diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 320d6c94ff84..4a243546d142 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -293,7 +293,9 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); #ifndef __compiletime_error # define __compiletime_error(message) #endif - +#ifndef __linktime_error +# define __linktime_error(message) +#endif /* * Prevent the compiler from merging or refetching accesses. The compiler * is also forbidden from reordering successive instances of ACCESS_ONCE(), diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e8b1597b5cf2..f48e8a528544 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -665,6 +665,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #define BUILD_BUG_ON_ZERO(e) (0) #define BUILD_BUG_ON_NULL(e) ((void*)0) #define BUILD_BUG_ON(condition) +#define BUILD_BUG() (0) #else /* __CHECKER__ */ /* Force a compilation error if a constant expression is not a power of 2 */ @@ -703,6 +704,21 @@ extern int __build_bug_on_failed; if (condition) __build_bug_on_failed = 1; \ } while(0) #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() \ + do { \ + extern void __build_bug_failed(void) \ + __linktime_error("BUILD_BUG failed"); \ + __build_bug_failed(); \ + } while (0) + #endif /* __CHECKER__ */ /* Trap pasters of __FUNCTION__ at compile-time */