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 AE478C61DB3 for ; Thu, 12 Jan 2023 17:46:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pG1dN-0002Oz-3a; Thu, 12 Jan 2023 12:45:03 -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 1pG1dC-0002Jj-Fd for qemu-devel@nongnu.org; Thu, 12 Jan 2023 12:44:51 -0500 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 1pG1dA-00037T-A5 for qemu-devel@nongnu.org; Thu, 12 Jan 2023 12:44:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673545486; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NtwoKh/3iAKB2XE/31DuEYgAr//oVfLpFtkMDcaEqpE=; b=HzXJ3B3y56sYVbuA0BiG1VKDZbtnp1Pf9urWetbgB7vo+dA+DapgVBdGBUzMbDhnRkL6Mm GZNxQkuwABmttKUoNzw7rdRsJElm2CI5+3PMwKjHeqYcKV5kGYSvguU5MnPabb5uKxQ7jc h452GpdgZPgWJpK2Vg6deRuPtu1Uhcc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-215-TbksA1BdNsefWnC0nIvYDQ-1; Thu, 12 Jan 2023 12:44:42 -0500 X-MC-Unique: TbksA1BdNsefWnC0nIvYDQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 924543813F35; Thu, 12 Jan 2023 17:44:40 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.222]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9F13D4085720; Thu, 12 Jan 2023 17:44:34 +0000 (UTC) Date: Thu, 12 Jan 2023 17:44:31 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: "Michael S. Tsirkin" Cc: Markus Armbruster , qemu-devel@nongnu.org, imp@bsdimp.com, kevans@freebsd.org, ben.widawsky@intel.com, jonathan.cameron@huawei.com, kbastian@mail.uni-paderborn.de, jasowang@redhat.com, michael.roth@amd.com, kkostiuk@redhat.com, tsimpson@quicinc.com, palmer@dabbelt.com, alistair.francis@wdc.com, bin.meng@windriver.com, qemu-riscv@nongnu.org, philmd@linaro.org, Bin Meng Subject: Re: [PATCH v3 1/1] include: Don't include qemu/osdep.h Message-ID: References: <20230112115005.1504812-1-armbru@redhat.com> <20230112115005.1504812-2-armbru@redhat.com> <20230112082537-mutt-send-email-mst@kernel.org> <20230112085520-mutt-send-email-mst@kernel.org> <87zgan4xoo.fsf@pond.sub.org> <20230112123434-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230112123434-mutt-send-email-mst@kernel.org> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_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: 2.1.29 Precedence: list List-Id: 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 Thu, Jan 12, 2023 at 12:37:46PM -0500, Michael S. Tsirkin wrote: > On Thu, Jan 12, 2023 at 03:47:19PM +0100, Markus Armbruster wrote: > > "Michael S. Tsirkin" writes: > > > > > On Thu, Jan 12, 2023 at 08:51:32AM -0500, Michael S. Tsirkin wrote: > > >> On Thu, Jan 12, 2023 at 12:50:05PM +0100, Markus Armbruster wrote: > > >> > docs/devel/style.rst mandates: > > >> > > > >> > The "qemu/osdep.h" header contains preprocessor macros that affect > > >> > the behavior of core system headers like . It must be > > >> > the first include so that core system headers included by external > > >> > libraries get the preprocessor macros that QEMU depends on. > > >> > > > >> > Do not include "qemu/osdep.h" from header files since the .c file > > >> > will have already included it. > > >> > > > >> > A few violations have crept in. Fix them. > > >> > > > >> > Signed-off-by: Markus Armbruster > > >> > Reviewed-by: Philippe Mathieu-Daudé > > >> > Reviewed-by: Bin Meng > > >> > Reviewed-by: Taylor Simpson > > >> > Reviewed-by: Alistair Francis > > >> > > >> With my awesome grep skillz I found one more: > > >> $ grep -r --include='*.h' qemu/osdep.h > > >> include/block/graph-lock.h:#include "qemu/osdep.h" > > > > Crept in after I prepared my v1. I neglected to re-check. > > > > > Also: > > > $ grep -r --include='*.inc' qemu/osdep.h > > > ui/vnc-enc-zrle.c.inc:#include "qemu/osdep.h" > > > crypto/akcipher-nettle.c.inc:#include "qemu/osdep.h" > > > crypto/akcipher-gcrypt.c.inc:#include "qemu/osdep.h" > > > crypto/rsakey-nettle.c.inc:#include "qemu/osdep.h" > > > crypto/cipher-gnutls.c.inc:#include "qemu/osdep.h" > > > target/xtensa/core-dc233c/xtensa-modules.c.inc:#include "qemu/osdep.h" > > > target/xtensa/core-sample_controller/xtensa-modules.c.inc:#include "qemu/osdep.h" > > > target/xtensa/core-de212/xtensa-modules.c.inc:#include "qemu/osdep.h" > > > target/xtensa/core-dc232b/xtensa-modules.c.inc:#include "qemu/osdep.h" > > > target/xtensa/core-fsf/xtensa-modules.c.inc:#include "qemu/osdep.h" > > > target/cris/translate_v10.c.inc:#include "qemu/osdep.h" > > > > Good point. Looks like I successfully supressed all memory of .inc. > > > > >> Looks like all C files must include qemu/osdep.h, no? > > > > I remember there are a few exceptions, but I don't remember which .c > > they are. Hmm... see commit 4bd802b209cff612d1a99674a91895b735be8630. > > > > >> How about > > >> > > >> 1- add -include qemu/osdep.h on compile command line > > >> drop #include "qemu/osdep.h" from C files > > > > Then you need to encode the exceptions in the build system. Which might > > not be a bad thing. > > > > >> 2- drop double include guards, replace with a warning. > > >> > > >> following patch implements part 2: > > >> > > >> > > >> qemu/osdep: don't include it from headers > > >> > > >> doing so will lead to trouble eventually - instead of > > >> working around such cases make it more likely it will fail. > > >> > > >> Signed-off-by: Michael S. Tsirkin > > >> > > >> --- > > >> > > >> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h > > >> index 7d059ad526..e4a60f911c 100644 > > >> --- a/include/qemu/osdep.h > > >> +++ b/include/qemu/osdep.h > > >> @@ -24,7 +24,12 @@ > > >> * This work is licensed under the terms of the GNU GPL, version 2 or later. > > >> * See the COPYING file in the top-level directory. > > >> */ > > >> -#ifndef QEMU_OSDEP_H > > >> +#ifdef QEMU_OSDEP_H > > >> +#warning "Never include qemu/osdep.h from a header!" > > >> +#endif > > >> + > > >> +static inline void qemu_osdep_never_include_from_header(void) {} > > >> + > > > > Why do you need the function, too? > > This seems to give a bit more info if header does get included > twice: instead of just a warning on the second include compiler says > definition is duplicated and then shows where the first definition was. > OTOH first one was almost for sure from the proper first include so > maybe we don't care. Let me drop this. FWIW, if we want to simplify our header guards, we could replace the #ifndef FOO_H #define FOO_H .... #endif /* FOO_H */ with merely #pragma once at the top of each header. With 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 :|