1 #ifndef _LINUX_BUG_H 2 #define _LINUX_BUG_H 3 4 #include <asm/bug.h> 5 #include <linux/compiler.h> 6 7 enum bug_trap_type { 8 BUG_TRAP_TYPE_NONE = 0, 9 BUG_TRAP_TYPE_WARN = 1, 10 BUG_TRAP_TYPE_BUG = 2, 11 }; 12 13 struct pt_regs; 14 15 #ifdef __CHECKER__ 16 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) 17 #define BUILD_BUG_ON_ZERO(e) (0) 18 #define BUILD_BUG_ON_NULL(e) ((void*)0) 19 #define BUILD_BUG_ON_INVALID(e) (0) 20 #define BUILD_BUG_ON(condition) (0) 21 #define BUILD_BUG() (0) 22 #else /* __CHECKER__ */ 23 24 /* Force a compilation error if a constant expression is not a power of 2 */ 25 #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ 26 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) 27 28 /* Force a compilation error if condition is true, but also produce a 29 result (of value 0 and type size_t), so the expression can be used 30 e.g. in a structure initializer (or where-ever else comma expressions 31 aren't permitted). */ 32 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) 33 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) 34 35 /* 36 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the 37 * expression but avoids the generation of any code, even if that expression 38 * has side-effects. 39 */ 40 #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) 41 42 /** 43 * BUILD_BUG_ON - break compile if a condition is true. 44 * @condition: the condition which the compiler should know is false. 45 * 46 * If you have some code which relies on certain constants being equal, or 47 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to 48 * detect if someone changes it. 49 * 50 * The implementation uses gcc's reluctance to create a negative array, but gcc 51 * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to 52 * inline functions). Luckily, in 4.3 they added the "error" function 53 * attribute just for this type of case. Thus, we use a negative sized array 54 * (should always create an error on gcc versions older than 4.4) and then call 55 * an undefined function with the error attribute (should always create an 56 * error on gcc 4.3 and later). If for some reason, neither creates a 57 * compile-time error, we'll still have a link-time error, which is harder to 58 * track down. 59 */ 60 #ifndef __OPTIMIZE__ 61 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) 62 #else 63 #define BUILD_BUG_ON(condition) \ 64 do { \ 65 bool __cond = !!(condition); \ 66 extern void __build_bug_on_failed(void) \ 67 __compiletime_error("BUILD_BUG_ON failed"); \ 68 if (__cond) \ 69 __build_bug_on_failed(); \ 70 ((void)sizeof(char[1 - 2 * __cond])); \ 71 } while (0) 72 #endif 73 74 /** 75 * BUILD_BUG - break compile if used. 76 * 77 * If you have some code that you expect the compiler to eliminate at 78 * build time, you should use BUILD_BUG to detect if it is 79 * unexpectedly used. 80 */ 81 #define BUILD_BUG() \ 82 do { \ 83 extern void __build_bug_failed(void) \ 84 __compiletime_error("BUILD_BUG failed");\ 85 __build_bug_failed(); \ 86 } while (0) 87 88 #endif /* __CHECKER__ */ 89 90 #ifdef CONFIG_GENERIC_BUG 91 #include <asm-generic/bug.h> 92 93 static inline int is_warning_bug(const struct bug_entry *bug) 94 { 95 return bug->flags & BUGFLAG_WARNING; 96 } 97 98 const struct bug_entry *find_bug(unsigned long bugaddr); 99 100 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); 101 102 /* These are defined by the architecture */ 103 int is_valid_bugaddr(unsigned long addr); 104 105 #else /* !CONFIG_GENERIC_BUG */ 106 107 static inline enum bug_trap_type report_bug(unsigned long bug_addr, 108 struct pt_regs *regs) 109 { 110 return BUG_TRAP_TYPE_BUG; 111 } 112 113 #endif /* CONFIG_GENERIC_BUG */ 114 #endif /* _LINUX_BUG_H */ 115