Re: [PATCH 2/2] kbuild: move -Wundef from KBUILD_CFLAGS to KBUILD_CPPFLAGS

[kernel test robot]

Hi Masahiro,

I love your patch! Perhaps something to improve:

[auto build test WARNING on masahiroy-kbuild/for-next]
[also build test WARNING on linus/master v6.0-rc4]
[cannot apply to next-20220901]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Masahiro-Yamada/kbuild-move-Werror-from-KBUILD_CFLAGS-to-KBUILD_CPPFLAGS/20220905-164209
base:   https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next
config: riscv-randconfig-r042-20220905 (https://download.01.org/0day-ci/archive/20220905/202209052329.sY4Fx2fi-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c55b41d5199d2394dd6cdb8f52180d8b81d809d4)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/2f8ee1865d7d00ad27460d94056c7752cad8481f
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Masahiro-Yamada/kbuild-move-Werror-from-KBUILD_CFLAGS-to-KBUILD_CPPFLAGS/20220905-164209
        git checkout 2f8ee1865d7d00ad27460d94056c7752cad8481f
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/

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

All warnings (new ones prefixed by >>):

>> arch/riscv/kernel/head.S:329:5: warning: 'CONFIG_RISCV_BOOT_SPINWAIT' is not defined, evaluates to 0 [-Wundef]
   #if CONFIG_RISCV_BOOT_SPINWAIT
       ^
   1 warning generated.


vim +/CONFIG_RISCV_BOOT_SPINWAIT +329 arch/riscv/kernel/head.S

76d2a0493a17d4 Palmer Dabbelt    2017-07-10  316  
76d4467a97bd8c Qiu Wenbo         2020-08-13  317  	call setup_trap_vector
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  318  	/* Restore C environment */
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  319  	la tp, init_task
c637b911e06697 Christoph Hellwig 2019-04-15  320  	la sp, init_thread_union + THREAD_SIZE
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  321  
8ad8b72721d0f0 Nick Hu           2020-01-06  322  #ifdef CONFIG_KASAN
8ad8b72721d0f0 Nick Hu           2020-01-06  323  	call kasan_early_init
8ad8b72721d0f0 Nick Hu           2020-01-06  324  #endif
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  325  	/* Start the kernel */
335b139057ef79 Damien Le Moal    2020-03-16  326  	call soc_early_init
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  327  	tail start_kernel
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  328  
2ffc48fc7071da Atish Patra       2022-01-20 @329  #if CONFIG_RISCV_BOOT_SPINWAIT
0b39eb38f85908 Atish Patra       2022-01-20  330  .Lsecondary_start:
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  331  	/* Set trap vector to spin forever to help debug */
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  332  	la a3, .Lsecondary_park
a4c3733d32a72f Christoph Hellwig 2019-10-28  333  	csrw CSR_TVEC, a3
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  334  
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  335  	slli a3, a0, LGREG
c78f94f35cf648 Atish Patra       2022-01-20  336  	la a1, __cpu_spinwait_stack_pointer
44c922572952d8 Vitaly Wool       2021-04-13  337  	XIP_FIXUP_OFFSET a1
c78f94f35cf648 Atish Patra       2022-01-20  338  	la a2, __cpu_spinwait_task_pointer
44c922572952d8 Vitaly Wool       2021-04-13  339  	XIP_FIXUP_OFFSET a2
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  340  	add a1, a3, a1
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  341  	add a2, a3, a2
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  342  
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  343  	/*
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  344  	 * This hart didn't win the lottery, so we wait for the winning hart to
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  345  	 * get far enough along the boot process that it should continue.
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  346  	 */
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  347  .Lwait_for_cpu_up:
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  348  	/* FIXME: We should WFI to save some energy here. */
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  349  	REG_L sp, (a1)
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  350  	REG_L tp, (a2)
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  351  	beqz sp, .Lwait_for_cpu_up
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  352  	beqz tp, .Lwait_for_cpu_up
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  353  	fence
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  354  
153c46faf6ae49 Jisheng Zhang     2021-11-29  355  	tail .Lsecondary_start_common
2ffc48fc7071da Atish Patra       2022-01-20  356  #endif /* CONFIG_RISCV_BOOT_SPINWAIT */
76d2a0493a17d4 Palmer Dabbelt    2017-07-10  357  

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