1 #ifndef _LINUX_BUG_H 2 #define _LINUX_BUG_H 3 4 #include <asm/bug.h> 5 6 enum bug_trap_type { 7 BUG_TRAP_TYPE_NONE = 0, 8 BUG_TRAP_TYPE_WARN = 1, 9 BUG_TRAP_TYPE_BUG = 2, 10 }; 11 12 struct pt_regs; 13 14 #ifdef __CHECKER__ 15 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) 16 #define BUILD_BUG_ON_ZERO(e) (0) 17 #define BUILD_BUG_ON_NULL(e) ((void*)0) 18 #define BUILD_BUG_ON(condition) 19 #define BUILD_BUG() (0) 20 #else /* __CHECKER__ */ 21 22 /* Force a compilation error if a constant expression is not a power of 2 */ 23 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 24 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 25 26 /* Force a compilation error if condition is true, but also produce a 27 result (of value 0 and type size_t), so the expression can be used 28 e.g. in a structure initializer (or where-ever else comma expressions 29 aren't permitted). */ 30 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 31 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 32 33 /** 34 * BUILD_BUG_ON - break compile if a condition is true. 35 * @condition: the condition which the compiler should know is false. 36 * 37 * If you have some code which relies on certain constants being equal, or 38 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 39 * detect if someone changes it. 40 * 41 * The implementation uses gcc's reluctance to create a negative array, but 42 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 43 * to inline functions). So as a fallback we use the optimizer; if it can't 44 * prove the condition is false, it will cause a link error on the undefined 45 * "__build_bug_on_failed". This error message can be harder to track down 46 * though, hence the two different methods. 47 */ 48 #ifndef __OPTIMIZE__ 49 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 50 #else 51 extern int __build_bug_on_failed; 52 #define BUILD_BUG_ON(condition) \ 53 do { \ 54 ((void)sizeof(char[1 - 2*!!(condition)])); \ 55 if (condition) __build_bug_on_failed = 1; \ 56 } while(0) 57 #endif 58 59 /** 60 * BUILD_BUG - break compile if used. 61 * 62 * If you have some code that you expect the compiler to eliminate at 63 * build time, you should use BUILD_BUG to detect if it is 64 * unexpectedly used. 65 */ 66 #define BUILD_BUG() \ 67 do { \ 68 extern void __build_bug_failed(void) \ 69 __linktime_error("BUILD_BUG failed"); \ 70 __build_bug_failed(); \ 71 } while (0) 72 73 #endif /* __CHECKER__ */ 74 75 #ifdef CONFIG_GENERIC_BUG 76 #include <asm-generic/bug.h> 77 78 static inline int is_warning_bug(const struct bug_entry *bug) 79 { 80 return bug->flags & BUGFLAG_WARNING; 81 } 82 83 const struct bug_entry *find_bug(unsigned long bugaddr); 84 85 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); 86 87 /* These are defined by the architecture */ 88 int is_valid_bugaddr(unsigned long addr); 89 90 #else /* !CONFIG_GENERIC_BUG */ 91 92 static inline enum bug_trap_type report_bug(unsigned long bug_addr, 93 struct pt_regs *regs) 94 { 95 return BUG_TRAP_TYPE_BUG; 96 } 97 98 #endif /* CONFIG_GENERIC_BUG */ 99 #endif /* _LINUX_BUG_H */ 100