Re: [PATCH v2] kbuild: add all Clang-specific flags unconditionally

From: Nick Desaulniers
Date: Fri May 10 2019 - 13:55:46 EST


On Fri, May 10, 2019 at 7:10 AM Masahiro Yamada
<yamada.masahiro@xxxxxxxxxxxxx> wrote:
>
> We do not support old Clang versions. Upgrade your clang version
> if any of these flags is unsupported.
>
> Let's add all flags within ifdef CONFIG_CC_IS_CLANG unconditionally.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> Reviewed-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

Ack

> ---
>
> Changes in v2:
> - Rebase on top of Nathan's patch
> https://patchwork.kernel.org/patch/10937055/
>
> Makefile | 10 +++++-----
> scripts/Makefile.extrawarn | 12 ++++++------
> 2 files changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index 914a3ad..1152fc4 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -731,15 +731,15 @@ stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
> KBUILD_CFLAGS += $(stackp-flags-y)
>
> ifdef CONFIG_CC_IS_CLANG
> -KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
> -KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
> -KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
> +KBUILD_CPPFLAGS += -Qunused-arguments
> +KBUILD_CFLAGS += -Wno-format-invalid-specifier
> +KBUILD_CFLAGS += -Wno-gnu
> # Quiet clang warning: comparison of unsigned expression < 0 is always false
> -KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
> +KBUILD_CFLAGS += -Wno-tautological-compare
> # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
> # source of a reference will be _MergedGlobals and not on of the whitelisted names.
> # See modpost pattern 2
> -KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
> +KBUILD_CFLAGS += -mno-global-merge
> else
>
> # These warnings generated too much noise in a regular build.
> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> index 768306a..523c4ca 100644
> --- a/scripts/Makefile.extrawarn
> +++ b/scripts/Makefile.extrawarn
> @@ -66,11 +66,11 @@ KBUILD_CFLAGS += $(warning)
> else
>
> ifdef CONFIG_CC_IS_CLANG
> -KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)
> -KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)
> -KBUILD_CFLAGS += $(call cc-disable-warning, format)
> -KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
> -KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
> -KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)
> +KBUILD_CFLAGS += -Wno-initializer-overrides
> +KBUILD_CFLAGS += -Wno-unused-value
> +KBUILD_CFLAGS += -Wno-format
> +KBUILD_CFLAGS += -Wno-sign-compare
> +KBUILD_CFLAGS += -Wno-format-zero-length
> +KBUILD_CFLAGS += -Wno-uninitialized
> endif
> endif
> --
> 2.7.4
>


--
Thanks,
~Nick Desaulniers