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_INVALID(e) (0) 19 #define BUILD_BUG_ON(condition) 20 #define BUILD_BUG() (0) 21 #else /* __CHECKER__ */ 22 23 /* Force a compilation error if a constant expression is not a power of 2 */ 24 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 25 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 26 27 /* Force a compilation error if condition is true, but also produce a 28 result (of value 0 and type size_t), so the expression can be used 29 e.g. in a structure initializer (or where-ever else comma expressions 30 aren't permitted). */ 31 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 32 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 33 34 /* 35 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the 36 * expression but avoids the generation of any code, even if that expression 37 * has side-effects. 38 */ 39 #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) 40 41 /** 42 * BUILD_BUG_ON - break compile if a condition is true. 43 * @condition: the condition which the compiler should know is false. 44 * 45 * If you have some code which relies on certain constants being equal, or 46 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to 47 * detect if someone changes it. 48 * 49 * The implementation uses gcc's reluctance to create a negative array, but 50 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments 51 * to inline functions). So as a fallback we use the optimizer; if it can't 52 * prove the condition is false, it will cause a link error on the undefined 53 * "__build_bug_on_failed". This error message can be harder to track down 54 * though, hence the two different methods. 55 */ 56 #ifndef __OPTIMIZE__ 57 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 58 #else 59 extern int __build_bug_on_failed; 60 #define BUILD_BUG_ON(condition) \ 61 do { \ 62 ((void)sizeof(char[1 - 2*!!(condition)])); \ 63 if (condition) __build_bug_on_failed = 1; \ 64 } while(0) 65 #endif 66 67 /** 68 * BUILD_BUG - break compile if used. 69 * 70 * If you have some code that you expect the compiler to eliminate at 71 * build time, you should use BUILD_BUG to detect if it is 72 * unexpectedly used. 73 */ 74 #define BUILD_BUG() \ 75 do { \ 76 extern void __build_bug_failed(void) \ 77 __linktime_error("BUILD_BUG failed"); \ 78 __build_bug_failed(); \ 79 } while (0) 80 81 #endif /* __CHECKER__ */ 82 83 #ifdef CONFIG_GENERIC_BUG 84 #include <asm-generic/bug.h> 85 86 static inline int is_warning_bug(const struct bug_entry *bug) 87 { 88 return bug->flags & BUGFLAG_WARNING; 89 } 90 91 const struct bug_entry *find_bug(unsigned long bugaddr); 92 93 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); 94 95 /* These are defined by the architecture */ 96 int is_valid_bugaddr(unsigned long addr); 97 98 #else /* !CONFIG_GENERIC_BUG */ 99 100 static inline enum bug_trap_type report_bug(unsigned long bug_addr, 101 struct pt_regs *regs) 102 { 103 return BUG_TRAP_TYPE_BUG; 104 } 105 106 #endif /* CONFIG_GENERIC_BUG */ 107 #endif /* _LINUX_BUG_H */ 108