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7664c5a1 JF |
1 | #ifndef _LINUX_BUG_H |
2 | #define _LINUX_BUG_H | |
3 | ||
7664c5a1 | 4 | #include <asm/bug.h> |
a3ccc497 | 5 | #include <linux/compiler.h> |
7664c5a1 JF |
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 | ||
608e2619 HC |
13 | struct pt_regs; |
14 | ||
35edd910 | 15 | #ifdef __CHECKER__ |
ca623c91 | 16 | #define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0) |
35edd910 PG |
17 | #define BUILD_BUG_ON_ZERO(e) (0) |
18 | #define BUILD_BUG_ON_NULL(e) ((void*)0) | |
c5782e9f | 19 | #define BUILD_BUG_ON_INVALID(e) (0) |
9a8ab1c3 | 20 | #define BUILD_BUG_ON_MSG(cond, msg) (0) |
ca623c91 | 21 | #define BUILD_BUG_ON(condition) (0) |
35edd910 | 22 | #define BUILD_BUG() (0) |
ff20c2e0 | 23 | #define MAYBE_BUILD_BUG_ON(cond) (0) |
35edd910 PG |
24 | #else /* __CHECKER__ */ |
25 | ||
26 | /* Force a compilation error if a constant expression is not a power of 2 */ | |
27 | #define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ | |
28 | BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) | |
29 | ||
30 | /* Force a compilation error if condition is true, but also produce a | |
31 | result (of value 0 and type size_t), so the expression can be used | |
32 | e.g. in a structure initializer (or where-ever else comma expressions | |
33 | aren't permitted). */ | |
34 | #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) | |
35 | #define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) | |
36 | ||
baf05aa9 KK |
37 | /* |
38 | * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the | |
39 | * expression but avoids the generation of any code, even if that expression | |
40 | * has side-effects. | |
41 | */ | |
42 | #define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e)))) | |
43 | ||
9a8ab1c3 DS |
44 | /** |
45 | * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied | |
46 | * error message. | |
47 | * @condition: the condition which the compiler should know is false. | |
48 | * | |
49 | * See BUILD_BUG_ON for description. | |
50 | */ | |
51 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | |
52 | ||
35edd910 PG |
53 | /** |
54 | * BUILD_BUG_ON - break compile if a condition is true. | |
55 | * @condition: the condition which the compiler should know is false. | |
56 | * | |
57 | * If you have some code which relies on certain constants being equal, or | |
a3ccc497 | 58 | * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to |
35edd910 PG |
59 | * detect if someone changes it. |
60 | * | |
a3ccc497 DS |
61 | * The implementation uses gcc's reluctance to create a negative array, but gcc |
62 | * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to | |
63 | * inline functions). Luckily, in 4.3 they added the "error" function | |
64 | * attribute just for this type of case. Thus, we use a negative sized array | |
65 | * (should always create an error on gcc versions older than 4.4) and then call | |
66 | * an undefined function with the error attribute (should always create an | |
67 | * error on gcc 4.3 and later). If for some reason, neither creates a | |
68 | * compile-time error, we'll still have a link-time error, which is harder to | |
69 | * track down. | |
35edd910 PG |
70 | */ |
71 | #ifndef __OPTIMIZE__ | |
72 | #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) | |
73 | #else | |
9a8ab1c3 DS |
74 | #define BUILD_BUG_ON(condition) \ |
75 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | |
35edd910 PG |
76 | #endif |
77 | ||
78 | /** | |
79 | * BUILD_BUG - break compile if used. | |
80 | * | |
81 | * If you have some code that you expect the compiler to eliminate at | |
82 | * build time, you should use BUILD_BUG to detect if it is | |
83 | * unexpectedly used. | |
84 | */ | |
9a8ab1c3 | 85 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") |
35edd910 | 86 | |
ff20c2e0 KS |
87 | #define MAYBE_BUILD_BUG_ON(cond) \ |
88 | do { \ | |
89 | if (__builtin_constant_p((cond))) \ | |
90 | BUILD_BUG_ON(cond); \ | |
91 | else \ | |
92 | BUG_ON(cond); \ | |
93 | } while (0) | |
94 | ||
35edd910 PG |
95 | #endif /* __CHECKER__ */ |
96 | ||
7664c5a1 JF |
97 | #ifdef CONFIG_GENERIC_BUG |
98 | #include <asm-generic/bug.h> | |
99 | ||
100 | static inline int is_warning_bug(const struct bug_entry *bug) | |
101 | { | |
102 | return bug->flags & BUGFLAG_WARNING; | |
103 | } | |
104 | ||
105 | const struct bug_entry *find_bug(unsigned long bugaddr); | |
106 | ||
608e2619 | 107 | enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); |
7664c5a1 | 108 | |
7664c5a1 JF |
109 | /* These are defined by the architecture */ |
110 | int is_valid_bugaddr(unsigned long addr); | |
111 | ||
112 | #else /* !CONFIG_GENERIC_BUG */ | |
113 | ||
608e2619 HC |
114 | static inline enum bug_trap_type report_bug(unsigned long bug_addr, |
115 | struct pt_regs *regs) | |
7664c5a1 JF |
116 | { |
117 | return BUG_TRAP_TYPE_BUG; | |
118 | } | |
7664c5a1 JF |
119 | |
120 | #endif /* CONFIG_GENERIC_BUG */ | |
121 | #endif /* _LINUX_BUG_H */ |