From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 62F75AD51; Mon, 2 Dec 2024 16:16:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733156173; cv=none; b=NDfjiCF4ZU8yKKzFqGVDr17zKpR/85FWTRhh6nZVvAiTBa0BMqCJCc6bbXVbyv5Sy+bkb891qxpOB9+zxi8zVejiHguNFVG0wUD/aRtoUzjbL6fIPnr/+FtCtlCa7tiuCDpmqzGGmh+v/CK2+M8f7/BZqYioBFhcaaTDCdzpc9Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733156173; c=relaxed/simple; bh=xlQywIlZNQT5qCo7G3nLeY962rjjbO5Mq7s9hOqzSTg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ot4eBzmD8mZ+3Q8KbdXoVR0Cifc3qHC4N6G4FBjzE7GGelK1JMlwCLrZrlN1VuNUpGGMC+a7y7S/DQbu8eyOoCbHkahMfHIb/0ewlDQO8ksg/oA1FLOxAv8zcCj5hldnrjeItdxgAWEvf4Cr90ZVjTnptN/OXhwjWe9pTAnTjuY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AM3jWJZp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AM3jWJZp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41270C4CED1; Mon, 2 Dec 2024 16:16:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733156172; bh=xlQywIlZNQT5qCo7G3nLeY962rjjbO5Mq7s9hOqzSTg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AM3jWJZp/CgkhVFK3t4ZwOl6h+mOxDJCQGTmx11N/Hf/ImgkXc1kb1eUP5yFTTFkj C542BBLgdoRljc3cFThdDsZ72G6r/Wt+ZH1IQ0idZd/D9REB3bX7SWEpc9Sd/kIzHD 9LAH3oMX8fddnzb7a9+AAFjcVrMUX2A3zUUUo4ec8CCiOjAH/qlsIEPn+5yPXSFXDH ub4vRhdTZyhfDZGdmUIwXyWBgmFF1qIMNm2zk0nzZkXpRvLQyz13Re+7H5HqORoTMg wTfKHqx+3iafT5IrwnauhRgnYebgSmavAeFUPCkVaOr1VCOuP/iXxvcwW4NGGRMm6H inpEPVj9t2ItQ== Date: Mon, 2 Dec 2024 09:16:10 -0700 From: Nathan Chancellor To: Masahiro Yamada Cc: Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Arnd Bergmann , Aleksei Vetrov , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, stable@vger.kernel.org Subject: Re: [PATCH v2] kbuild: Move -Wenum-enum-conversion to W=2 Message-ID: <20241202161610.GA2845796@thelio-3990X> References: <20241017-disable-two-clang-enum-warnings-v2-1-163ac04346ae@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241017-disable-two-clang-enum-warnings-v2-1-163ac04346ae@kernel.org> Masahiro, could you please pick this up? The lore link is below in case it is no longer in your inbox (or I can resend). https://lore.kernel.org/20241017-disable-two-clang-enum-warnings-v2-1-163ac04346ae@kernel.org/ On Thu, Oct 17, 2024 at 10:09:22AM -0700, Nathan Chancellor wrote: > -Wenum-enum-conversion was strengthened in clang-19 to warn for C, which > caused the kernel to move it to W=1 in commit 75b5ab134bb5 ("kbuild: > Move -Wenum-{compare-conditional,enum-conversion} into W=1") because > there were numerous instances that would break builds with -Werror. > Unfortunately, this is not a full solution, as more and more developers, > subsystems, and distributors are building with W=1 as well, so they > continue to see the numerous instances of this warning. > > Since the move to W=1, there have not been many new instances that have > appeared through various build reports and the ones that have appeared > seem to be following similar existing patterns, suggesting that most > instances of this warning will not be real issues. The only alternatives > for silencing this warning are adding casts (which is generally seen as > an ugly practice) or refactoring the enums to macro defines or a unified > enum (which may be undesirable because of type safety in other parts of > the code). > > Move the warning to W=2, where warnings that occur frequently but may be > relevant should reside. > > Cc: stable@vger.kernel.org > Fixes: 75b5ab134bb5 ("kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1") > Link: https://lore.kernel.org/ZwRA9SOcOjjLJcpi@google.com/ > Signed-off-by: Nathan Chancellor > --- > Changes in v2: > - Move -Wenum-enum-conversion to W=2, instead of disabling it > outright (Arnd) > - Leave -Wenum-compare-conditional in W=1, as there are not that > many instances, so it can be turned on fully at some point (Arnd) > - Link to v1: https://lore.kernel.org/r/20241016-disable-two-clang-enum-warnings-v1-1-ae886d7a0269@kernel.org > --- > scripts/Makefile.extrawarn | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn > index 1d13cecc7cc7808610e635ddc03476cf92b3a8c1..04faf15ed316a9c291dc952b6cc40fb6c8c330cf 100644 > --- a/scripts/Makefile.extrawarn > +++ b/scripts/Makefile.extrawarn > @@ -130,7 +130,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast) > KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare > KBUILD_CFLAGS += $(call cc-disable-warning, unaligned-access) > KBUILD_CFLAGS += -Wno-enum-compare-conditional > -KBUILD_CFLAGS += -Wno-enum-enum-conversion > endif > > endif > @@ -154,6 +153,10 @@ KBUILD_CFLAGS += -Wno-missing-field-initializers > KBUILD_CFLAGS += -Wno-type-limits > KBUILD_CFLAGS += -Wno-shift-negative-value > > +ifdef CONFIG_CC_IS_CLANG > +KBUILD_CFLAGS += -Wno-enum-enum-conversion > +endif > + > ifdef CONFIG_CC_IS_GCC > KBUILD_CFLAGS += -Wno-maybe-uninitialized > endif > > --- > base-commit: 8e929cb546ee42c9a61d24fae60605e9e3192354 > change-id: 20241016-disable-two-clang-enum-warnings-e7994d44f948 > > Best regards, > -- > Nathan Chancellor >