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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 2 Aug 2021 14:14:55 -0700
Message-ID: <CAKwvOdkSzuMpjwP=_vPfs0QFAytA9=fZ00Aw4dn8fk7=P5WhLA@mail.gmail.com>
Subject: Re: [PATCH v6 1/3] Makefile: move initial clang flag handling into scripts/Makefile.clang
To:     =?UTF-8?B?RsSBbmctcnXDrCBTw7JuZw==?= <maskray@google.com>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Arnd Bergmann <arnd@kernel.org>, linux-kernel@vger.kernel.org,
        linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Christoph Hellwig <hch@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Nathan Chancellor <nathan@kernel.org>
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On Mon, Aug 2, 2021 at 2:06 PM F=C4=81ng-ru=C3=AC S=C3=B2ng <maskray@google=
.com> wrote:
>
> On Mon, Aug 2, 2021 at 11:39 AM Nick Desaulniers
> <ndesaulniers@google.com> wrote:
> > diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang
> > new file mode 100644
> > index 000000000000..297932e973d4
> > --- /dev/null
> > +++ b/scripts/Makefile.clang
> > @@ -0,0 +1,14 @@
> > +ifneq ($(CROSS_COMPILE),)
> > +CLANG_FLAGS    +=3D --target=3D$(notdir $(CROSS_COMPILE:%-=3D%))
> > +endif
> > +ifeq ($(LLVM_IAS),1)
> > +CLANG_FLAGS    +=3D -integrated-as
>
> -i* options are for includes. -fintegrated-as is the canonical spelling.
> Since -fintegrated-as is the default (for most llvm/lib/Target/
> targets and the ones clang builds actually support),
> it can even be deleted.

It was made explicit by Masahiro in
git.kernel.org/linus/ba64beb17493a4bfec563100c86a462a15926f24
So I don't think we need to go back to the implicit default.

It's definitely nicer to use groupings rather than these raw prefixed
flags IMO.  If you sent a patch for that I would approve of it.
Otherwise we don't really need to change this as this is how it's
worked in LLVM for as long as we've been able to build the kernel with
LLVM.
--=20
Thanks,
~Nick Desaulniers