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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 525E6C43331 for ; Tue, 31 Mar 2020 15:13:22 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 19F6420781 for ; Tue, 31 Mar 2020 15:13:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LAvDw/cQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 19F6420781 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39920 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJIZt-00089G-7e for qemu-devel@archiver.kernel.org; Tue, 31 Mar 2020 11:13:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58318) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJIVF-0000fz-3T for qemu-devel@nongnu.org; Tue, 31 Mar 2020 11:08:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jJIVD-00009U-TH for qemu-devel@nongnu.org; Tue, 31 Mar 2020 11:08:33 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:27268 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jJIVD-00009G-OW for qemu-devel@nongnu.org; Tue, 31 Mar 2020 11:08:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585667311; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/LNpoz8aWTCoVmYrAr/sG2mvzTcv0QTP8Wo8cAzE0Ts=; b=LAvDw/cQ3wP0OdYxJho72wWsIJ6AX7SIgtOnxrCqN/6WD8XJ5jpdozB/7xiNrWOvMC9oyt i6h/s4TcNKlBhxfQ45mR3gV96XY9Ryyd+EF9fi0VTXxG9clnKkY7LpTkwZQo+ixkg1Qi1f CxF+o95vb4xp149F50PpLbFBGOQhCQ4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-263-VHlxT52xPLObpVJM72fh3A-1; Tue, 31 Mar 2020 11:08:29 -0400 X-MC-Unique: VHlxT52xPLObpVJM72fh3A-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 70D3F8024D8; Tue, 31 Mar 2020 15:08:28 +0000 (UTC) Received: from [10.3.113.246] (ovpn-113-246.phx2.redhat.com [10.3.113.246]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E43B6118F49; Tue, 31 Mar 2020 15:08:27 +0000 (UTC) Subject: Re: deprecation of in-tree builds To: Kevin Wolf , Paolo Bonzini References: <87v9mmug73.fsf@dusky.pond.sub.org> <20200330134212.GO236854@redhat.com> <20200330143759.GD6139@linux.fritz.box> <20200331120220.GA7030@linux.fritz.box> From: Eric Blake Organization: Red Hat, Inc. Message-ID: Date: Tue, 31 Mar 2020 10:08:27 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200331120220.GA7030@linux.fritz.box> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= , Markus Armbruster , QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/31/20 7:02 AM, Kevin Wolf wrote: > Am 31.03.2020 um 09:48 hat Paolo Bonzini geschrieben: >> On 30/03/20 16:37, Kevin Wolf wrote: >>> If manually dealing with separate build directories is inconvenient >>> today, it will still be inconvenient with Meson, so this would mean >>> introducing the automatic directly creation together with the other >>> changes to enable Meson. Which is fine by me, as long as it is really >>> done when the external directory becomes mandatory, so that people won't >>> have to switch back and forth between directories. >> >> Serious question: why is automatic directly creation more convenient for >> developers? Even if "./configure" generates a "build" directory for >> you, you would still have to invoke the QEMU binary as >> "build/x86_64-softmmu/qemu-system-x86_64". That is less convenient than >> doing "mkdir build" in the first place. > > Mainly because it allows me to start everything (most importantly: my > editor, git and make) from the same directory. > > I guess the automatic directory creation is the less important part > compared to a Makefile in the source tree that calls the Makefile in the > build directory, because creation the directory is a one-time thing, but > I call make all the time. If we make in-tree ./configure create a GNUmakefile shim that auto-forwards to build/, it would also be possible to create symlinks to the various targets that will live in build. I recently switched my qemu playground to use VPATH builds, but with symlinks such as qemu-img -> build/qemu-img, I can still use my muscle memory of an in-tree build for normal development. > > Creating it automatically is nice especially for those who build QEMU > for the first time and expect that the ./configure; make; make install > sequence they are used to just works. > > Prefixing build/ when using the binaries is a change, too, but I guess > tab completion means that it's not much worse than prefixing ./ With symlinks, it is possible to give much more than 'make' the illusion of working in-tree. It then boils down to a question of how many symlinks are worth creating. > >> I can see why it's more convenient for packaging, as they just invoke >> "make" and "make install", but as far as developers are concerned it >> seems to add complexity for little or no gain. > > I often use the same terminal for building/testing and git, or sometimes > even a second editor for source code. > > Kevin > > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org