Failed to compile current kernel with llvm/clang

Hi all,

I am trying to build world and kernel with llvm according to
instructions on wiki:

http://wiki.freebsd.org/BuildingFreeBSDWithClang

buildworld is fine, but when building GENERIC kernel it failed on hpt27xx:

===> hpt27xx (all)
/usr/src/sys/modules/hpt27xx/../../dev/hpt27xx/osm_bsd.c:1180:25:
error: format string is not a string literal (potentially insecure)
[-Werror,-Wformat-security]
            S_IRUSR | S_IWUSR, driver_name);
                               ^~~~~~~~~~~
_at_/dev/hpt27xx/hpt27xx_config.h:46:21: note: expanded from:
#define driver_name hpt27xx_driver_name
                    ^~~~~~~~~~~~~~~~~~~

I cannot find symbol hpt27xx_driver_name in that directory. Is it
expanded from some macros I am not aware of?


BTW clang does generate much friendly and useful warnings so far as I saw.


Regards,
Jia-Shiun