The branch main has been updated by bz: URL: https://cgit.FreeBSD.org/src/commit/?id=1082490cd867a4d443862523c37ce947735342d0
commit 1082490cd867a4d443862523c37ce947735342d0 Author: Bjoern A. Zeeb <[email protected]> AuthorDate: 2021-05-24 18:26:41 +0000 Commit: Bjoern A. Zeeb <[email protected]> CommitDate: 2021-05-25 18:01:47 +0000 LinuxKPI: change BUILD_BUG_ON() BUILD_BUG_ON() can be used inside functions where the definition to CTASSERT() (_Static_assert()) seems to not work. Go back to an old-style CTASSERT() implementation but also add a variable dclaration to avoid "unsued typedef" errors and dummy-use the variable to avoid "unusued variable" errors. Given it is all self-contained in a block and not used outside this should be optimised away. Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Reviewed by: hselasky Differential Revision: https://reviews.freebsd.org/D30431 --- sys/compat/linuxkpi/common/include/linux/kernel.h | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/sys/compat/linuxkpi/common/include/linux/kernel.h b/sys/compat/linuxkpi/common/include/linux/kernel.h index b30fa8ba5729..807138334fdd 100644 --- a/sys/compat/linuxkpi/common/include/linux/kernel.h +++ b/sys/compat/linuxkpi/common/include/linux/kernel.h @@ -89,8 +89,23 @@ #define S64_C(x) x ## LL #define U64_C(x) x ## ULL +/* + * BUILD_BUG_ON() can happen inside functions where _Static_assert() does not + * seem to work. Use old-schoold-ish CTASSERT from before commit + * a3085588a88fa58eb5b1eaae471999e1995a29cf but also make sure we do not + * end up with an unused typedef or variable. The compiler should optimise + * it away entirely. + */ +#define _O_CTASSERT(x) _O__CTASSERT(x, __LINE__) +#define _O__CTASSERT(x, y) _O___CTASSERT(x, y) +#define _O___CTASSERT(x, y) while (0) { \ + typedef char __assert_line_ ## y[(x) ? 1 : -1]; \ + __assert_line_ ## y _x; \ + _x[0] = '\0'; \ +} + #define BUILD_BUG() do { CTASSERT(0); } while (0) -#define BUILD_BUG_ON(x) CTASSERT(!(x)) +#define BUILD_BUG_ON(x) _O_CTASSERT(!(x)) #define BUILD_BUG_ON_MSG(x, msg) BUILD_BUG_ON(x) #define BUILD_BUG_ON_NOT_POWER_OF_2(x) BUILD_BUG_ON(!powerof2(x)) #define BUILD_BUG_ON_INVALID(expr) while (0) { (void)(expr); } _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/dev-commits-src-all To unsubscribe, send any mail to "[email protected]"
