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_INVALID() permits the compiler to check the validity of the 35 * expression but avoids the generation of any code, even if that expression 36 * has side-effects. 37 */ 38 #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) 39 40 /** 41 * BUILD_BUG_ON - break compile if a condition is true. 42 * @condition: the condition which the compiler should know is false. 43 * 44 * If you have some code which relies on certain constants being equal, or 45 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 46 * detect if someone changes it. 47 * 48 * The implementation uses gcc's reluctance to create a negative array, but 49 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 50 * to inline functions). So as a fallback we use the optimizer; if it can't 51 * prove the condition is false, it will cause a link error on the undefined 52 * "__build_bug_on_failed". This error message can be harder to track down 53 * though, hence the two different methods. 54 */ 55 #ifndef __OPTIMIZE__ 56 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 57 #else 58 extern int __build_bug_on_failed; 59 #define BUILD_BUG_ON(condition) \ 60 do { \ 61 ((void)sizeof(char[1 - 2*!!(condition)])); \ 62 if (condition) __build_bug_on_failed = 1; \ 63 } while(0) 64 #endif 65 66 /** 67 * BUILD_BUG - break compile if used. 68 * 69 * If you have some code that you expect the compiler to eliminate at 70 * build time, you should use BUILD_BUG to detect if it is 71 * unexpectedly used. 72 */ 73 #define BUILD_BUG() \ 74 do { \ 75 extern void __build_bug_failed(void) \ 76 __linktime_error("BUILD_BUG failed"); \ 77 __build_bug_failed(); \ 78 } while (0) 79 80 #endif /* __CHECKER__ */ 81 82 #ifdef CONFIG_GENERIC_BUG 83 #include <asm-generic/bug.h> 84 85 static inline int is_warning_bug(const struct bug_entry *bug) 86 { 87 return bug->flags & BUGFLAG_WARNING; 88 } 89 90 const struct bug_entry *find_bug(unsigned long bugaddr); 91 92 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); 93 94 /* These are defined by the architecture */ 95 int is_valid_bugaddr(unsigned long addr); 96 97 #else /* !CONFIG_GENERIC_BUG */ 98 99 static inline enum bug_trap_type report_bug(unsigned long bug_addr, 100 struct pt_regs *regs) 101 { 102 return BUG_TRAP_TYPE_BUG; 103 } 104 105 #endif /* CONFIG_GENERIC_BUG */ 106 #endif /* _LINUX_BUG_H */ 107