drivers/firmware/efi/libstub/skip_spaces.c:6:7: warning: no previous prototype for 'skip_spaces'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   623f6dc593eaf98b91916836785278eddddaacf8
commit: 91d150c0cc637b9d9d6394936add7cd2b7ccc410 efi/libstub: Clean up command line parsing routine
date:   4 months ago
config: arm-randconfig-r002-20200611 (attached as .config)
compiler: arm-linux-gnueabi-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
        git checkout 91d150c0cc637b9d9d6394936add7cd2b7ccc410
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 

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

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

>> drivers/firmware/efi/libstub/skip_spaces.c:6:7: warning: no previous prototype for 'skip_spaces' [-Wmissing-prototypes]
6 | char *skip_spaces(const char *str)
|       ^~~~~~~~~~~
--
>> drivers/firmware/efi/libstub/string.c:83:20: warning: no previous prototype for 'simple_strtoull' [-Wmissing-prototypes]
83 | unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
|                    ^~~~~~~~~~~~~~~
>> drivers/firmware/efi/libstub/string.c:108:6: warning: no previous prototype for 'simple_strtol' [-Wmissing-prototypes]
108 | long simple_strtol(const char *cp, char **endp, unsigned int base)
|      ^~~~~~~~~~~~~

vim +/skip_spaces +6 drivers/firmware/efi/libstub/skip_spaces.c

     5	
   > 6	char *skip_spaces(const char *str)

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

Attachment: .config.gz
Description: application/gzip