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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44465104950E for ; Wed, 11 Mar 2026 09:32:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w0FvF-0006lo-LE; Wed, 11 Mar 2026 05:32:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w0Fv3-0006lD-6C for qemu-devel@nongnu.org; Wed, 11 Mar 2026 05:31:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w0Fv1-0002oe-4a for qemu-devel@nongnu.org; Wed, 11 Mar 2026 05:31:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1773221514; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=jkvx31t9gR5JlTmGPN0dtXMZryBIOqOv+dGCKIDCz/Y=; b=SV4eyZGf82Vaik+UJqy4rWd78uPbkk9KWXUuDZYkSKoJ6minTeO8NGDr9UrSznCKcDG6nh ZRJMGgEm962Wo0wppujKooV74dLEx2V5ZVcNMsadYdindrUGhywi2VUq2zFgc3EO5Na0VR pdh+jVe/r47Xbho6l8csGnBFESslDAo= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-253-ESnZQ-JZNy-6dCiixXBElQ-1; Wed, 11 Mar 2026 05:31:50 -0400 X-MC-Unique: ESnZQ-JZNy-6dCiixXBElQ-1 X-Mimecast-MFC-AGG-ID: ESnZQ-JZNy-6dCiixXBElQ_1773221509 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7765E18002CF; Wed, 11 Mar 2026 09:31:49 +0000 (UTC) Received: from redhat.com (unknown [10.44.33.160]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A15BF180066F; Wed, 11 Mar 2026 09:31:46 +0000 (UTC) Date: Wed, 11 Mar 2026 09:31:42 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Thomas Huth Cc: nia , Peter Maydell , Fabiano Rosas , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Paolo Bonzini Subject: Re: Minimal GCC version for QEMU Message-ID: References: <20260309155219.62400-1-philmd@linaro.org> <20260309155219.62400-28-philmd@linaro.org> <87h5qn23v5.fsf@suse.de> <6660d0a8-c5f8-4f4c-a097-9aa1fb1501b6@redhat.com> <1c26bf07-1d19-4764-9f6f-28b47a7f0f8b@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1c26bf07-1d19-4764-9f6f-28b47a7f0f8b@redhat.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.819, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.903, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Mar 11, 2026 at 08:28:01AM +0100, Thomas Huth wrote: > On 11/03/2026 00.06, nia wrote: > > On Tue, Mar 10, 2026 at 04:47:30PM +0100, Thomas Huth wrote: > > > According to that URL from NetBSD that I posted above, they are still using > > > LLVM 10.0 in NetBSD 10 ... which is also our current minimum version of > > > Clang, so I assume we're still stuck with Clang v10 for a while? > > > > Since I was CCed in this discussion - can I ask why qemu is targeting > > compiler versions instead of C standard revisions? > > Hi! > > QEMU already uses std=gnu11. The problem is that different compiler versions > emit different warnings, and with older compilers, there are often warnings > that are false positives (see e.g. > https://lore.kernel.org/qemu-devel/87h5qn23v5.fsf@suse.de/ that just has > been posted to the mailing list recently). The QEMU project tries to avoid > supporting operating systems / build environments that are too old (see > https://www.qemu.org/docs/master/about/build-platforms.html), we often just > don't have the capacity in the developer community to handle that, so that's > why we put compiler checks into place to avoid wrong expectations for the > users. Furthermore, the minimum GCC + CLang versions are what we use to determine what GNU C standard revision we can set as our baseline. For example see this previous commit: commit 8a9d3d564093dbd5a7339085406e840893944d21 Author: Richard Henderson Date: Mon Jun 14 16:31:36 2021 -0700 configure: Use -std=gnu11 Now that the minimum gcc version is 7.5, we can use C11. This will allow lots of cleanups to the code, currently hidden behind macros in include/qemu/compiler.h. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|