Re: [PATCH v2 2/2] kbuild: consolidate Clang compiler flags

[Greg Hackmann]

On 11/09/2018 10:29 AM, Nick Desaulniers wrote:
> On Mon, Nov 5, 2018 at 7:05 PM Masahiro Yamada
> <yamada.masahiro@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> > ---
> >
> > 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@xxxxxxxxxx>
> Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>
> Would you mind waiting for a tested-by from Stefan, and maybe an ack
> from Greg (added to cc)?

Acked-by: Greg Hackmann <ghackmann@xxxxxxxxxx>