5 #include <linux/compiler.h>
8 BUG_TRAP_TYPE_NONE = 0,
9 BUG_TRAP_TYPE_WARN = 1,
10 BUG_TRAP_TYPE_BUG = 2,
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__ */
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))
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
32 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
33 #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
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
40 #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
43 * BUILD_BUG_ON - break compile if a condition is true.
44 * @condition: the condition which the compiler should know is false.
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.
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
61 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
63 #define BUILD_BUG_ON(condition) \
65 bool __cond = !!(condition); \
66 extern void __build_bug_on_failed(void) \
67 __compiletime_error("BUILD_BUG_ON failed"); \
69 __build_bug_on_failed(); \
70 __compiletime_error_fallback(__cond); \
75 * BUILD_BUG - break compile if used.
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
83 extern void __build_bug_failed(void) \
84 __compiletime_error("BUILD_BUG failed");\
85 __build_bug_failed(); \
88 #endif /* __CHECKER__ */
90 #ifdef CONFIG_GENERIC_BUG
91 #include <asm-generic/bug.h>
93 static inline int is_warning_bug(const struct bug_entry *bug)
95 return bug->flags & BUGFLAG_WARNING;
98 const struct bug_entry *find_bug(unsigned long bugaddr);
100 enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
102 /* These are defined by the architecture */
103 int is_valid_bugaddr(unsigned long addr);
105 #else /* !CONFIG_GENERIC_BUG */
107 static inline enum bug_trap_type report_bug(unsigned long bug_addr,
108 struct pt_regs *regs)
110 return BUG_TRAP_TYPE_BUG;
113 #endif /* CONFIG_GENERIC_BUG */
114 #endif /* _LINUX_BUG_H */