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-rw-r--r--include/linux/bug.h74
1 files changed, 1 insertions, 73 deletions
diff --git a/include/linux/bug.h b/include/linux/bug.h
index 483207cb99fb..5d5554c874fd 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -3,6 +3,7 @@
3 3
4#include <asm/bug.h> 4#include <asm/bug.h>
5#include <linux/compiler.h> 5#include <linux/compiler.h>
6#include <linux/build_bug.h>
6 7
7enum bug_trap_type { 8enum bug_trap_type {
8 BUG_TRAP_TYPE_NONE = 0, 9 BUG_TRAP_TYPE_NONE = 0,
@@ -13,82 +14,9 @@ enum bug_trap_type {
13struct pt_regs; 14struct pt_regs;
14 15
15#ifdef __CHECKER__ 16#ifdef __CHECKER__
16#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
17#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
18#define BUILD_BUG_ON_ZERO(e) (0)
19#define BUILD_BUG_ON_NULL(e) ((void *)0)
20#define BUILD_BUG_ON_INVALID(e) (0)
21#define BUILD_BUG_ON_MSG(cond, msg) (0)
22#define BUILD_BUG_ON(condition) (0)
23#define BUILD_BUG() (0)
24#define MAYBE_BUILD_BUG_ON(cond) (0) 17#define MAYBE_BUILD_BUG_ON(cond) (0)
25#else /* __CHECKER__ */ 18#else /* __CHECKER__ */
26 19
27/* Force a compilation error if a constant expression is not a power of 2 */
28#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \
29 BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
30#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
31 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
32
33/*
34 * Force a compilation error if condition is true, but also produce a
35 * result (of value 0 and type size_t), so the expression can be used
36 * e.g. in a structure initializer (or where-ever else comma expressions
37 * aren't permitted).
38 */
39#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
40#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:(-!!(e)); }))
41
42/*
43 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
44 * expression but avoids the generation of any code, even if that expression
45 * has side-effects.
46 */
47#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
48
49/**
50 * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
51 * error message.
52 * @condition: the condition which the compiler should know is false.
53 *
54 * See BUILD_BUG_ON for description.
55 */
56#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
57
58/**
59 * BUILD_BUG_ON - break compile if a condition is true.
60 * @condition: the condition which the compiler should know is false.
61 *
62 * If you have some code which relies on certain constants being equal, or
63 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
64 * detect if someone changes it.
65 *
66 * The implementation uses gcc's reluctance to create a negative array, but gcc
67 * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
68 * inline functions). Luckily, in 4.3 they added the "error" function
69 * attribute just for this type of case. Thus, we use a negative sized array
70 * (should always create an error on gcc versions older than 4.4) and then call
71 * an undefined function with the error attribute (should always create an
72 * error on gcc 4.3 and later). If for some reason, neither creates a
73 * compile-time error, we'll still have a link-time error, which is harder to
74 * track down.
75 */
76#ifndef __OPTIMIZE__
77#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
78#else
79#define BUILD_BUG_ON(condition) \
80 BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
81#endif
82
83/**
84 * BUILD_BUG - break compile if used.
85 *
86 * If you have some code that you expect the compiler to eliminate at
87 * build time, you should use BUILD_BUG to detect if it is
88 * unexpectedly used.
89 */
90#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
91
92#define MAYBE_BUILD_BUG_ON(cond) \ 20#define MAYBE_BUILD_BUG_ON(cond) \
93 do { \ 21 do { \
94 if (__builtin_constant_p((cond))) \ 22 if (__builtin_constant_p((cond))) \