Hi Nick,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on hnaz-linux-mm/master]
[also build test ERROR on kees/for-next/pstore linus/master v5.8 next-20200814]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Nick-Desaulniers/lib-string-c-implement-stpcpy/20200816-090542
base:   https://github.com/hnaz/linux-mm master
config: ia64-defconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "stpcpy" [sound/pci/ac97/snd-ac97-codec.ko] undefined!

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org