LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: Nathan Chancellor <natechancellor@gmail.com>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Arnd Bergmann <arnd@arndb.de>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Michal Marek <michal.lkml@markovi.net>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kbuild: add most of Clang-specific flags unconditionally
Date: Thu, 9 May 2019 20:35:05 +0900	[thread overview]
Message-ID: <CAK7LNASpsid7_sh4rdRNSTwZ1YtW_+uH2eoarJNNUttntQZ-kg@mail.gmail.com> (raw)
In-Reply-To: <20190509111534.GA32696@archlinux-i9>

Hi.

On Thu, May 9, 2019 at 8:15 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Thu, May 09, 2019 at 03:44:55PM +0900, Masahiro Yamada wrote:
> > We do not support old Clang versions. Upgrade your clang version
> > if any of these flags is unsupported.
> >
> > Let's add flags within ifdef CONFIG_CC_IS_CLANG unconditionally,
> > except -fcatch-undefined-behavior.
> >
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> > ---
> >
> >  Makefile                   | 10 +++++-----
> >  scripts/Makefile.extrawarn | 12 ++++++------
> >  2 files changed, 11 insertions(+), 11 deletions(-)
> >
> > diff --git a/Makefile b/Makefile
> > index bd7ae11947cb..c71ffb6f55b5 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
> >  KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
>
> I think we should just remove this, I'm fairly confident the kernel
> can't be reliably compiled with anything earlier than Clang 4 (Pixel 2
> was shipped with it but had some hacks, this commit is from Clang 3.5):
>
> https://github.com/llvm/llvm-project/commit/cb3f812b6b9fab8f3b41414f24e90222170417b4


Oh, I did not know this was deprecated.

Could you send a patch to remove it
with filling the commit log ?


Thanks.



-- 
Best Regards
Masahiro Yamada

  reply	other threads:[~2019-05-09 11:36 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-09  6:44 Masahiro Yamada
2019-05-09  7:06 ` Sedat Dilek
2019-05-10 13:53   ` Masahiro Yamada
2019-05-10 17:57     ` Nick Desaulniers
2019-05-09 11:15 ` Nathan Chancellor
2019-05-09 11:35   ` Masahiro Yamada [this message]
2019-05-09 11:40     ` Nathan Chancellor
2019-05-09 11:48     ` [PATCH] Makefile: Don't try to add '-fcatch-undefined-behavior' flag Nathan Chancellor
2019-05-09 13:33       ` Masahiro Yamada
2019-05-09 13:49       ` Sedat Dilek
2019-05-09 17:01         ` Nick Desaulniers
2019-05-13  2:23       ` Masahiro Yamada
2019-05-09 17:17   ` [PATCH] kbuild: add most of Clang-specific flags unconditionally Nick Desaulniers

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAK7LNASpsid7_sh4rdRNSTwZ1YtW_+uH2eoarJNNUttntQZ-kg@mail.gmail.com \
    --to=yamada.masahiro@socionext.com \
    --cc=arnd@arndb.de \
    --cc=clang-built-linux@googlegroups.com \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=michal.lkml@markovi.net \
    --cc=natechancellor@gmail.com \
    --cc=ndesaulniers@google.com \
    --subject='Re: [PATCH] kbuild: add most of Clang-specific flags unconditionally' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).