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 95F9E21B458; Fri, 8 Nov 2024 17:46:41 +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=1731088001; cv=none; b=uLKFvcbVy2APetz4FpwkhyrX3DWBU+KgylaikdS/epGLxcgGOKLikxqZKUEsV2GQya3WcgrZfdhTj3ztTV5VlyFYvzvmjVKSJyA73AfnyEBSW5fjCvo9Gldwe/gP70mbDAc+kym7atopoGefqUClbJJO/e6zsNj8ToGTu4DA1wI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731088001; c=relaxed/simple; bh=v6CMakwqFx7aJagpFs1cS1sDWNqmR4HwbpiSyjF0JjI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hQUjqbYbBD32Oa/7ENHzbJu6jmdQE0xyjbJDItDM2Ok6TVwNBnJbl4M84i41WZqW3kgNNnnncCHaUoKGXQTaoPXMQjkAHarhv5arS7wtE8L+LZ/Q2QXCsCYgUZGoerDmHwW02sdTZy6i1/x2PDcj4Mut9lxQRinCaAKSy2WxZ2M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TzoWCT0k; 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="TzoWCT0k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D023C4CECD; Fri, 8 Nov 2024 17:46:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731088001; bh=v6CMakwqFx7aJagpFs1cS1sDWNqmR4HwbpiSyjF0JjI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TzoWCT0km7qIjw6wL3OQkxyzDX0V9ucpTetlaamJ9ckgAU38Z9fLuOVnzv4AlDvCg 9spSlI7s5sY68DEpeZU6kS4yCQ0Nd03kJDWqLxJJ92HtF1KVbTzYwICdBgl3tbevsA rTHxnrdXb2uWxrt9SpkCooT2WbBTay8FoA1Vwpohti1nCZ/SAua3oLJqYtDqHbAopu V4Y//A82tSDQwwHOxjL9O4Cn1r9TOTp7I2LcWl00oXrKLYPIi083zMJD78lkNASHeB urKvx5ZfAq/7qeZT8kibjd8hh841efdPtqAqG7WpBE7uHT+oXkByZqA+NHbHlPRpnF O5uFOfViW09gg== Date: Fri, 8 Nov 2024 10:46:38 -0700 From: Nathan Chancellor To: Rong Xu Cc: Masahiro Yamada , Nicolas Schier , Han Shen , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH] kbuild: Fix Propeller build option Message-ID: <20241108174638.GC2564051@thelio-3990X> References: <20241108051030.2918950-1-xur@google.com> Precedence: bulk X-Mailing-List: linux-kbuild@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: <20241108051030.2918950-1-xur@google.com> Hi Rong, Thanks for the quick patch! On Thu, Nov 07, 2024 at 09:10:30PM -0800, Rong Xu wrote: > The '-fbasic-block-sections=labels' option has been deprecated with > the following llvm patch: > https://github.com/llvm/llvm-project/pull/110039 > > The old option still works, but with a warning like > clang: warning: argument '-fbasic-block-sections=labels' \ > is deprecated, use '-fbasic-block-address-map' instead [-Wdeprecated] > > Currently, the option change is only in the ToT clang (v20) and not yet > released in v19. I think this whole block could be a little easier to read and understand with some more standard kernel commit message practices. I would combine the first and third block into one sentence and I would unwrap the warning text (it is okay to be long for a little clarity). Perhaps something like this? | The '-fbasic-block-sections=labels' option has been deprecated in tip of | tree clang (20.0.0) [1]. While the option still works, a warning is | emitted: | | clang: warning: argument '-fbasic-block-sections=labels' is deprecated, use '-fbasic-block-address-map' instead [-Wdeprecated] then putting: | Link: https://github.com/llvm/llvm-project/pull/110039 [1] right above your Signoff. > This patch adds a check to the Makefile to set the proper option. Try to avoid saying "this patch" in kernel commit messages, it is implicit. It would be cleaner to say something like: | Add a version check to set the proper option. You can see some more commit message tips in sections 4.2.3 to 4.2.6 in the tip documentation: https://docs.kernel.org/process/maintainer-tip.html#changelog > If the option change is later integrated in v19.x, we need to update the > check accordingly. I think it is worth dropping this sentence entirely, as I would argue that it is pretty unlikely that this option gets backported to release/19.x, since it would basically accelerate the deprecation timeline, which seems unreasonable to do in a stable release. > Signed-off-by: Rong Xu > Reported-by: Nathan Chancellor > --- > scripts/Makefile.propeller | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/scripts/Makefile.propeller b/scripts/Makefile.propeller > index 344190717e47..1a68ea0d1fe4 100644 > --- a/scripts/Makefile.propeller > +++ b/scripts/Makefile.propeller > @@ -5,7 +5,13 @@ ifdef CLANG_PROPELLER_PROFILE_PREFIX > CFLAGS_PROPELLER_CLANG := -fbasic-block-sections=list=$(CLANG_PROPELLER_PROFILE_PREFIX)_cc_profile.txt -ffunction-sections > KBUILD_LDFLAGS += --symbol-ordering-file=$(CLANG_PROPELLER_PROFILE_PREFIX)_ld_profile.txt --no-warn-symbol-ordering > else > - CFLAGS_PROPELLER_CLANG := -fbasic-block-sections=labels > + # Staring with clang v20, the '-fbasic-block-sections=labels' option is > + # deprecated. Use the recommended '-fbasic-block-address-map' option. Might be worth linking the specific change here for archeology sake. > + ifeq ($(call clang-min-version, 200000),y) > + CFLAGS_PROPELLER_CLANG := -fbasic-block-address-map > + else > + CFLAGS_PROPELLER_CLANG := -fbasic-block-sections=labels > + endif > endif > > # Propeller requires debug information to embed module names in the profiles. > @@ -21,7 +27,11 @@ ifdef CONFIG_LTO_CLANG_THIN > ifdef CLANG_PROPELLER_PROFILE_PREFIX > KBUILD_LDFLAGS += --lto-basic-block-sections=$(CLANG_PROPELLER_PROFILE_PREFIX)_cc_profile.txt > else > - KBUILD_LDFLAGS += --lto-basic-block-sections=labels > + ifeq ($(call clang-min-version, 200000),y) Would it be better/more accurate to check the LLD version here? I doubt it would really happen but it is possible for someone to have LLVM=1 (using their system wide ld.lld and LLVM tools) and CC=clang-20 to just use an updated clang. Perhaps: ifeq ($(call test-ge, $(CONFIG_LLD_VERSION), 200000),y) here? > + KBUILD_LDFLAGS += --lto-basic-block-address-map > + else > + KBUILD_LDFLAGS += --lto-basic-block-sections=labels > + endif > endif > endif > > > base-commit: 0dcc2d1066150787017a71f035145c566597dec7 > -- > 2.47.0.277.g8800431eea-goog >