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![Paul Gortmaker](/assets/img/avatar_default.png)
The support for BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h -- with this chunk off separate, you can run into situations where a person gets a compile fail even when they've included linux/bug.h, like this: CC lib/string.o lib/string.c: In function 'strlcat': lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON' make[2]: *** [lib/string.o] Error 1 $ $ grep linux/bug.h lib/string.c #include <linux/bug.h> $ Since the above violates the principle of least surprise, move the BUG chunks from kernel.h to bug.h so it is all together. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
99 lines
2.9 KiB
C
99 lines
2.9 KiB
C
#ifndef _LINUX_BUG_H
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#define _LINUX_BUG_H
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#include <asm/bug.h>
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enum bug_trap_type {
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BUG_TRAP_TYPE_NONE = 0,
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BUG_TRAP_TYPE_WARN = 1,
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BUG_TRAP_TYPE_BUG = 2,
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};
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struct pt_regs;
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#ifdef __CHECKER__
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#define BUILD_BUG_ON_NOT_POWER_OF_2(n)
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#define BUILD_BUG_ON_ZERO(e) (0)
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#define BUILD_BUG_ON_NULL(e) ((void*)0)
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#define BUILD_BUG_ON(condition)
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#define BUILD_BUG() (0)
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#else /* __CHECKER__ */
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/* Force a compilation error if a constant expression is not a power of 2 */
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#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
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BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
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/* Force a compilation error if condition is true, but also produce a
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result (of value 0 and type size_t), so the expression can be used
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e.g. in a structure initializer (or where-ever else comma expressions
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aren't permitted). */
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#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
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#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
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/**
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* BUILD_BUG_ON - break compile if a condition is true.
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* @condition: the condition which the compiler should know is false.
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*
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* If you have some code which relies on certain constants being equal, or
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* other compile-time-evaluated condition, you should use BUILD_BUG_ON to
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* detect if someone changes it.
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*
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* The implementation uses gcc's reluctance to create a negative array, but
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* gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
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* to inline functions). So as a fallback we use the optimizer; if it can't
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* prove the condition is false, it will cause a link error on the undefined
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* "__build_bug_on_failed". This error message can be harder to track down
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* though, hence the two different methods.
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*/
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#ifndef __OPTIMIZE__
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#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
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#else
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extern int __build_bug_on_failed;
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#define BUILD_BUG_ON(condition) \
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do { \
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((void)sizeof(char[1 - 2*!!(condition)])); \
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if (condition) __build_bug_on_failed = 1; \
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} while(0)
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#endif
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/**
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* BUILD_BUG - break compile if used.
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*
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* If you have some code that you expect the compiler to eliminate at
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* build time, you should use BUILD_BUG to detect if it is
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* unexpectedly used.
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*/
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#define BUILD_BUG() \
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do { \
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extern void __build_bug_failed(void) \
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__linktime_error("BUILD_BUG failed"); \
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__build_bug_failed(); \
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} while (0)
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#endif /* __CHECKER__ */
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#ifdef CONFIG_GENERIC_BUG
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#include <asm-generic/bug.h>
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static inline int is_warning_bug(const struct bug_entry *bug)
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{
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return bug->flags & BUGFLAG_WARNING;
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}
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const struct bug_entry *find_bug(unsigned long bugaddr);
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enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
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/* These are defined by the architecture */
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int is_valid_bugaddr(unsigned long addr);
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#else /* !CONFIG_GENERIC_BUG */
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static inline enum bug_trap_type report_bug(unsigned long bug_addr,
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struct pt_regs *regs)
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{
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return BUG_TRAP_TYPE_BUG;
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}
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#endif /* CONFIG_GENERIC_BUG */
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#endif /* _LINUX_BUG_H */
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