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 1BEC2C3DA7D for ; Tue, 3 Jan 2023 16:12:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pCjtU-0005sW-No; Tue, 03 Jan 2023 11:12:04 -0500 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 1pCjtP-0005s0-Uv for qemu-devel@nongnu.org; Tue, 03 Jan 2023 11:12:00 -0500 Received: from rev.ng ([5.9.113.41]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pCjtN-0008Uk-NJ for qemu-devel@nongnu.org; Tue, 03 Jan 2023 11:11:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=rev.ng; s=dkim; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References: In-Reply-To:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=4SFNX5uuRS5FmewEVzBo6cpE8IUY6ZrNEIxOMqe8Gt0=; b=BQQvgPUko5gUqWlA+Cb1BUpEUn j9wJdCvvUo3dLFgpgQuv/BfGueBP1b/aFgReb4Pn18xB+53UpD0Yuhl5wGKO6DqgWiCekHe2vE8ja a784ehj+aldVPyYu+p5G7XOJkadoh6OPR3Yfk52x9bC5ekWYhPUg8iKhGXKPEAG8VsLY=; Date: Tue, 3 Jan 2023 17:11:49 +0100 To: Stefan Hajnoczi Cc: qemu-devel@nongnu.org, Thomas Huth , Taylor Simpson , Anton Johansson , philmd@linaro.org, peter.maydell@linaro.org, bcain@quicinc.com, quic_mathbern@quicinc.com, stefanha@redhat.com, Paolo Bonzini Subject: Re: [PATCH] Update scripts/meson-buildoptions.sh Message-ID: <20230103171149.3bcf0526@orange> In-Reply-To: References: <20230102104113.3438895-1-ale@rev.ng> <20230103162603.74f631aa@orange> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=5.9.113.41; envelope-from=ale@rev.ng; helo=rev.ng X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Alessandro Di Federico From: Alessandro Di Federico via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, 3 Jan 2023 10:51:36 -0500 Stefan Hajnoczi wrote: > QEMU's Makefile used to a use a technique where it generated > "timestamp" files and used cmp(1) to check if rebuilding was > necessary: > 1. Always generate meson-buildoptions.sh-timestamp. `meson-buildoptions.sh-timestamp` would be the full expected output, right? It's not just a date or something. AFAIU that would make sure that if nothing changed in the output you don't trigger other targets depending on `meson-buildoptions.sh`. It's a solution for a different problem. The problem with always rebuilding `meson-buildoptions.sh` is that we spend 1 extra second on every build, even those that doesn't need to rebuild anything else. Not unacceptable, but I think we should strive not to commit generated files and move the file to the build directory, unless there's a reason why this is not viable that I'm not seeing. -- Alessandro Di Federico rev.ng Labs