Re: [PATCH] kbuild: support W=c and W=e shorthands for Kconfig

Nathan Chancellor
2023-11-30T00:15:26Z

On Thu, Nov 23, 2023 at 06:05:40PM +0900, Masahiro Yamada wrote:
> KCONFIG_WARN_UNKNOWN_SYMBOLS=1 and KCONFIG_WERROR=1 are descriptive
> and suitable in scripting, but it is tedious to type them from the
> command line.
>
> Associate them with KBUILD_EXTRA_WARN (and the W= shorthand).
>
> Support a new letter 'c' for KBUILD_EXTRA_WARN to enable extra checks
> in Kconfig. You can still manage compiler warnings (W=1) and Kconfig
> warnings (W=c) independently.
>
> Reuse the letter 'e' to turn Kconfig warnings into errors.
>
> As usual, you can combine multiple letters in KCONFIG_EXTRA_WARN.
>
> $ KCONFIG_WARN_UNKNOWN_SYMBOLS=1 KCONFIG_WERROR=1 make defconfig
>
> can be shortened to:
>
> $ KBUILD_EXTRA_WARN=ce make defconfig
>
> or, even shorter:
>
> $ make W=ce defconfig
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Seems reasonable to me.

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>
> Makefile | 10 ++++++++++
> scripts/Makefile.extrawarn | 9 ---------
> scripts/kconfig/Makefile | 8 ++++++++
> 3 files changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index f128a1a1b1a0..91947f722b77 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -155,6 +155,15 @@ endif
>
> export KBUILD_EXTMOD
>
> +# backward compatibility
> +KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
> +
> +ifeq ("$(origin W)", "command line")
> + KBUILD_EXTRA_WARN := $(W)
> +endif
> +
> +export KBUILD_EXTRA_WARN
> +
> # Kbuild will save output files in the current working directory.
> # This does not need to match to the root of the kernel source tree.
> #
> @@ -1659,6 +1668,7 @@ help:
> @echo ' 1: warnings which may be relevant and do not occur too often'
> @echo ' 2: warnings which occur quite often but may still be relevant'
> @echo ' 3: more obscure warnings, can most likely be ignored'
> + @echo ' c: extra checks in the configuration stage (Kconfig)'
> @echo ' e: warnings are being treated as errors'
> @echo ' Multiple levels can be combined with W=12 or W=123'
> @$(if $(dtstree), \
> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> index 2fe6f2828d37..3f94915fab37 100644
> --- a/scripts/Makefile.extrawarn
> +++ b/scripts/Makefile.extrawarn
> @@ -80,15 +80,6 @@ KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
> # Warn if there is an enum types mismatch
> KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion)
>
> -# backward compatibility
> -KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
> -
> -ifeq ("$(origin W)", "command line")
> - KBUILD_EXTRA_WARN := $(W)
> -endif
> -
> -export KBUILD_EXTRA_WARN
> -
> #
> # W=1 - warnings which may be relevant and do not occur too often
> #
> diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
> index 4eee155121a8..322c061b464d 100644
> --- a/scripts/kconfig/Makefile
> +++ b/scripts/kconfig/Makefile
> @@ -27,6 +27,14 @@ KCONFIG_DEFCONFIG_LIST += \
> endif
> KCONFIG_DEFCONFIG_LIST += arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)
>
> +ifneq ($(findstring c, $(KBUILD_EXTRA_WARN)),)
> +export KCONFIG_WARN_UNKNOWN_SYMBOLS=1
> +endif
> +
> +ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
> +export KCONFIG_WERROR=1
> +endif
> +
> # We need this, in case the user has it in its environment
> unexport CONFIG_
>
> --
> 2.40.1
>