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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Tue, 21 Aug 2018 09:35:31 -0700
Message-ID: <CAKwvOdmFqz6M+dPbYBMdOVMkDyLD568zNFOyva+20GK66h3Qrg@mail.gmail.com>
Subject: Re: [PATCH] compiler-gcc: get back Clang build
To:     joe@perches.com
Cc:     Masahiro Yamada <yamada.masahiro@socionext.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Arnd Bergmann <arnd@arndb.de>, dwmw@amazon.co.uk,
        LKML <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <will.deacon@arm.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
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On Tue, Aug 21, 2018 at 3:39 AM Joe Perches <joe@perches.com> wrote:
>
> On Tue, 2018-08-21 at 15:48 +0900, Masahiro Yamada wrote:
> > Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
> > missed the fact that <linux/compiler-gcc.h> is included by Clang
> > as well as by GCC.
> >
> > Clang actually defines __GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__
> > and it looks like GCC 4.2.1.
> >
> >   $ scripts/gcc-version.sh -p clang
> >   040201
>
> Perhaps this would work, but I can't test it as
> my clang version doesn't otherwise build a defconfig
> and errors out with
>
> $ make CC=clang
> arch/x86/Makefile:179: *** Compiler lacks asm-goto support..  Stop.

Sorry, we're working on implementing this in clang and llvm for x86.
I recently reviewed the design doc, and am trying to see how I can
actively help push this along.  It's not a small/quick change to llvm,
but we're working on it.

-- 
Thanks,
~Nick Desaulniers