From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 421E3C3A589 for ; Tue, 20 Aug 2019 13:54:40 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C08BB22CF7 for ; Tue, 20 Aug 2019 13:54:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C08BB22CF7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46CXND5CHYzDqQd for ; Tue, 20 Aug 2019 23:54:36 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=permerror (mailfrom) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46CVl90xPBzDqRj for ; Tue, 20 Aug 2019 22:40:52 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x7KCeYgc030746; Tue, 20 Aug 2019 07:40:34 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x7KCeXYY030745; Tue, 20 Aug 2019 07:40:33 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Tue, 20 Aug 2019 07:40:33 -0500 From: Segher Boessenkool To: Nathan Chancellor Subject: Re: [PATCH] powerpc: Don't add -mabi= flags when building with Clang Message-ID: <20190820124033.GQ31406@gate.crashing.org> References: <20190818191321.58185-1-natechancellor@gmail.com> <20190819091930.GZ31406@gate.crashing.org> <20190820031538.GC30221@archlinux-threadripper> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190820031538.GC30221@archlinux-threadripper> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Paul Mackerras , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Aug 19, 2019 at 08:15:38PM -0700, Nathan Chancellor wrote: > On Mon, Aug 19, 2019 at 04:19:31AM -0500, Segher Boessenkool wrote: > > On Sun, Aug 18, 2019 at 12:13:21PM -0700, Nathan Chancellor wrote: > > > When building pseries_defconfig, building vdso32 errors out: > > > > > > error: unknown target ABI 'elfv1' > > > > > > Commit 4dc831aa8813 ("powerpc: Fix compiling a BE kernel with a > > > powerpc64le toolchain") added these flags to fix building GCC but > > > clang is multitargeted and does not need these flags. The ABI is > > > properly set based on the target triple, which is derived from > > > CROSS_COMPILE. > > > > You mean that LLVM does not *allow* you to select a different ABI, or > > different ABI options, you always have to use the default. (Everything > > else you say is true for GCC as well). > > I need to improve the wording of the commit message as it is really that > clang does not allow a different ABI to be selected for 32-bit PowerPC, > as the setABI function is not overridden and it defaults to false. > GCC appears to just silently ignores this flag (I think it is the > SUBSUBTARGET_OVERRIDE_OPTIONS macro in gcc/config/rs6000/linux64.h). What flag? -mabi=elfv[12]? (Only irrelevant things are ever ignored; otherwise, please do a bug report). > It can be changed for 64-bit PowerPC it seems but it doesn't need to be > with clang because everything is set properly internally (I'll find a > better way to clearly word that as I am sure I'm not quite getting that > subtlety right). You can have elfv2 on BE, and e.g. the sysv ABI on LE. Neither of those is tested a lot. > > (-mabi= does not set a "target ABI", fwiw, it is more subtle; please see > > the documentation. Unless LLVM is incompatible in that respect as well?) > > Are you referring to the error message? Yup. > I suppose I could file an LLVM > bug report on that but that message applies to all of the '-mabi=' > options, which may refer to a target ABI. That depends on what you call "an ABI", I guess. You can call any ABI variant a separate ABI: you'll have to rebuild all of userland. You can also says ELFv1 and ELFv2 are pretty much the same thing, which is true as well. The way -mabi= is defined is the latter: '-mabi=ABI-TYPE' Extend the current ABI with a particular extension, or remove such extension. Valid values are 'altivec', 'no-altivec', 'ibmlongdouble', 'ieeelongdouble', 'elfv1', 'elfv2'. Segher