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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E0DDC433EF for ; Fri, 1 Oct 2021 15:18:09 +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 D645C61A40 for ; Fri, 1 Oct 2021 15:18:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D645C61A40 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:50696 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mWKIZ-0005pA-Ie for qemu-devel@archiver.kernel.org; Fri, 01 Oct 2021 11:18:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57622) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mWKHX-00057R-Ey for qemu-devel@nongnu.org; Fri, 01 Oct 2021 11:17:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28658) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mWKHT-0001TX-EM for qemu-devel@nongnu.org; Fri, 01 Oct 2021 11:17:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633101417; 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=Xiq9JZW3Z0ko76hWys98cF+zfkB35WXJn3lS564i/TM=; b=ZL8momtoGuzz650cztrAi8GO6ki8Wt8XoeIa25seANLZGPJKXt0BDdlcC/CN7m8+20qv4C 1oJ9kc7cBks87LT5OoGYS2sLz6ieYu5wBpGeIY0lmNDzjK8qg5ZB8D3d+kcNX32EiW5vOP y4lh3OlHvx+KnftGQT73ApObuGjHk1I= 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-433-ZEeUPmwKO429PjEe1K8UYQ-1; Fri, 01 Oct 2021 11:16:52 -0400 X-MC-Unique: ZEeUPmwKO429PjEe1K8UYQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1780C8010ED; Fri, 1 Oct 2021 15:16:51 +0000 (UTC) Received: from redhat.com (unknown [10.39.195.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EA5B65F4E1; Fri, 1 Oct 2021 15:16:49 +0000 (UTC) Date: Fri, 1 Oct 2021 16:16:47 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Christian Schoenebeck Subject: Re: [PATCH 1/5] 9pfs: introduce P9Array Message-ID: References: MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Richard Henderson , qemu-devel@nongnu.org, Greg Kurz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Oct 01, 2021 at 04:26:17PM +0200, Christian Schoenebeck wrote: > Implements deep auto free of arrays while retaining common C-style > squared bracket access. Main purpose of this API is to get rid of > error prone individual array deallocation pathes in user code, i.e. > turning something like this: > > void doSomething(size_t n) { > Foo *foos = malloc(n * sizeof(Foo)); > for (...) { > foos[i].s = malloc(...); > if (...) { > goto out; > } > } > out: > if (...) { > for (...) { > /* deep deallocation */ > free(foos[i].s); > } > /* array deallocation */ > free(foos); > } > } > > into something more simple and safer like: > > void doSomething(size_t n) { > P9ARRAY_REF(Foo) foos = NULL; > P9ARRAY_NEW(Foo, foos, n); > for (...) { > foos[i].s = malloc(...); > if (...) { > return; /* array auto freed here */ > } > } > /* array auto freed here */ > } As explained before, I'm against the idea of introducing new ways to automatically free local variables that are not using g_auto* functionality. It is not following the QEMU wide coding style that is documented. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|