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From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Sun, 11 Nov 2018 23:03:33 +0900
Message-ID: <CAK7LNAR32=QWy4jss3M3VSNj0XY=tvgWWTG5ajVEpyYD2J+Z1Q@mail.gmail.com>
Subject: Re: [PATCH v2 2/2] kbuild: consolidate Clang compiler flags
To:     Greg Hackmann <ghackmann@google.com>,
        Joel Stanley <joel@jms.id.au>,
        Nick Desaulniers <ndesaulniers@google.com>
Cc:     Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Stefan Agner <stefan@agner.ch>,
        Matthias Kaehlcke <mka@chromium.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Michal Marek <michal.lkml@markovi.net>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Nathan Chancellor <natechancellor@gmail.com>
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On Sat, Nov 10, 2018 at 3:35 AM Greg Hackmann <ghackmann@google.com> wrote:
>
> On 11/09/2018 10:29 AM, Nick Desaulniers wrote:
> > On Mon, Nov 5, 2018 at 7:05 PM Masahiro Yamada
> > <yamada.masahiro@socionext.com> wrote:
> >>
> >> Collect basic Clang options such as --target, --prefix, --gcc-toolchain,
> >> -no-integrated-as into a single variable CLANG_FLAGS so that it can be
> >> easily reused in other parts of Makefile.
> >>
> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> >> ---
> >>
> >> Changes in v2:
> >>   - Use := flavor instead of = because $(CLANG_FLAGS) is expanded soon anyway
> >>
> >>   Makefile | 13 ++++++-------
> >>   1 file changed, 6 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/Makefile b/Makefile
> >> index da11700..e173a73 100644
> >> --- a/Makefile
> >> +++ b/Makefile
> >> @@ -487,18 +487,17 @@ endif
> >>
> >>   ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
> >>   ifneq ($(CROSS_COMPILE),)
> >> -CLANG_TARGET   := --target=$(notdir $(CROSS_COMPILE:%-=%))
> >> +CLANG_FLAGS    := --target=$(notdir $(CROSS_COMPILE:%-=%))
> >>   GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
> >> -CLANG_PREFIX   := --prefix=$(GCC_TOOLCHAIN_DIR)
> >> +CLANG_FLAGS    += --prefix=$(GCC_TOOLCHAIN_DIR)
> >>   GCC_TOOLCHAIN  := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
> >>   endif
> >>   ifneq ($(GCC_TOOLCHAIN),)
> >> -CLANG_GCC_TC   := --gcc-toolchain=$(GCC_TOOLCHAIN)
> >> +CLANG_FLAGS    += --gcc-toolchain=$(GCC_TOOLCHAIN)
> >>   endif
> >> -KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
> >> -KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
> >> -KBUILD_CFLAGS += -no-integrated-as
> >> -KBUILD_AFLAGS += -no-integrated-as
> >> +CLANG_FLAGS    += -no-integrated-as
> >> +KBUILD_CFLAGS  += $(CLANG_FLAGS)
> >> +KBUILD_AFLAGS  += $(CLANG_FLAGS)
> >>   endif
> >>
> >>   RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
> >> --
> >> 2.7.4
> >>
> >
> > Thanks for this patch, Masahiro, it's a good simplification.
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> >
> > Would you mind waiting for a tested-by from Stefan, and maybe an ack
> > from Greg (added to cc)?
> >
>
> Acked-by: Greg Hackmann <ghackmann@google.com>


Thanks for your review!


So, how to organize this series, and Joel's one together?

I'd like Joel to use this series as a base for his work.
(https://lore.kernel.org/patchwork/patch/1006696/)

It will be much cleaner.


Shall I merge all the patches to kbuild tree, or
maybe will they go through powerpc tree?


--
Best Regards
Masahiro Yamada