84 строки
2.9 KiB
C
84 строки
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_BUILD_BUG_H
|
|
#define _LINUX_BUILD_BUG_H
|
|
|
|
#include <linux/compiler.h>
|
|
|
|
#ifdef __CHECKER__
|
|
#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
|
|
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
|
|
#define BUILD_BUG_ON_ZERO(e) (0)
|
|
#define BUILD_BUG_ON_INVALID(e) (0)
|
|
#define BUILD_BUG_ON_MSG(cond, msg) (0)
|
|
#define BUILD_BUG_ON(condition) (0)
|
|
#define BUILD_BUG() (0)
|
|
#else /* __CHECKER__ */
|
|
|
|
/* Force a compilation error if a constant expression is not a power of 2 */
|
|
#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \
|
|
BUILD_BUG_ON(((n) & ((n) - 1)) != 0)
|
|
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
|
|
BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
|
|
|
|
/*
|
|
* Force a compilation error if condition is true, but also produce a
|
|
* result (of value 0 and type size_t), so the expression can be used
|
|
* e.g. in a structure initializer (or where-ever else comma expressions
|
|
* aren't permitted).
|
|
*/
|
|
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); }))
|
|
|
|
/*
|
|
* BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
|
|
* expression but avoids the generation of any code, even if that expression
|
|
* has side-effects.
|
|
*/
|
|
#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))
|
|
|
|
/**
|
|
* BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
|
|
* error message.
|
|
* @condition: the condition which the compiler should know is false.
|
|
*
|
|
* See BUILD_BUG_ON for description.
|
|
*/
|
|
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
|
|
|
|
/**
|
|
* BUILD_BUG_ON - break compile if a condition is true.
|
|
* @condition: the condition which the compiler should know is false.
|
|
*
|
|
* If you have some code which relies on certain constants being equal, or
|
|
* some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
|
|
* detect if someone changes it.
|
|
*
|
|
* The implementation uses gcc's reluctance to create a negative array, but gcc
|
|
* (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
|
|
* inline functions). Luckily, in 4.3 they added the "error" function
|
|
* attribute just for this type of case. Thus, we use a negative sized array
|
|
* (should always create an error on gcc versions older than 4.4) and then call
|
|
* an undefined function with the error attribute (should always create an
|
|
* error on gcc 4.3 and later). If for some reason, neither creates a
|
|
* compile-time error, we'll still have a link-time error, which is harder to
|
|
* track down.
|
|
*/
|
|
#ifndef __OPTIMIZE__
|
|
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
|
|
#else
|
|
#define BUILD_BUG_ON(condition) \
|
|
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
|
|
#endif
|
|
|
|
/**
|
|
* BUILD_BUG - break compile if used.
|
|
*
|
|
* If you have some code that you expect the compiler to eliminate at
|
|
* build time, you should use BUILD_BUG to detect if it is
|
|
* unexpectedly used.
|
|
*/
|
|
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
|
|
|
|
#endif /* __CHECKER__ */
|
|
|
|
#endif /* _LINUX_BUILD_BUG_H */
|