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