Hi Josh,

I love your patch! Yet something to improve:

[auto build test ERROR on tip/master]
[also build test ERROR on linus/master v5.11-rc3 next-20210115]
[cannot apply to xen-tip/linux-next tip/x86/core]
[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/Josh-Poimboeuf/objtool-vmlinux-o-and-CLANG-LTO-support/20210115-125439
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 2c2adbc40b7276518921864053f3c02034b2290f
config: x86_64-randconfig-r021-20210115 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 5b42fd8dd4e7e29125a09a41a33af7c9cb57d144)
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
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/f06729b24980b0cdff19419510b17f5b493dc756
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Josh-Poimboeuf/objtool-vmlinux-o-and-CLANG-LTO-support/20210115-125439
        git checkout f06729b24980b0cdff19419510b17f5b493dc756
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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 >>):

>> elf.c:409:8: error: unused variable 'coldstr' [-Werror,-Wunused-variable]
           char *coldstr;
                 ^
   1 error generated.
   make[4]: *** [tools/build/Makefile.build:96: tools/objtool/elf.o] Error 1
   make[3]: *** [Makefile:59: tools/objtool/objtool-in.o] Error 2
--
>> elf.c:409:8: error: unused variable 'coldstr' [-Werror,-Wunused-variable]
           char *coldstr;
                 ^
   1 error generated.
   make[4]: *** [tools/build/Makefile.build:96: tools/objtool/elf.o] Error 1
   make[3]: *** [Makefile:59: tools/objtool/objtool-in.o] Error 2
   make[2]: *** [Makefile:68: objtool] Error 2
   make[1]: *** [Makefile:1931: tools/objtool] Error 2
   make[1]: Target 'modules_prepare' not remade because of errors.
   make: *** [Makefile:185: __sub-make] Error 2
   make: Target 'modules_prepare' not remade because of errors.
--
>> elf.c:409:8: error: unused variable 'coldstr' [-Werror,-Wunused-variable]
           char *coldstr;
                 ^
   1 error generated.
   make[4]: *** [tools/build/Makefile.build:96: tools/objtool/elf.o] Error 1
   make[4]: *** Waiting for unfinished jobs....
   make[3]: *** [Makefile:59: tools/objtool/objtool-in.o] Error 2
   make[2]: *** [Makefile:68: objtool] Error 2
   make[1]: *** [Makefile:1931: tools/objtool] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:185: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.

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