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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 93BFCC43331 for ; Thu, 26 Mar 2020 09:51:06 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 6D9AE2070A for ; Thu, 26 Mar 2020 09:51:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D9AE2070A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHPA4-0001v0-H9; Thu, 26 Mar 2020 09:50:52 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHPA2-0001uv-Uh for xen-devel@lists.xenproject.org; Thu, 26 Mar 2020 09:50:50 +0000 X-Inumbo-ID: 462da72e-6f47-11ea-bec1-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 462da72e-6f47-11ea-bec1-bc764e2007e4; Thu, 26 Mar 2020 09:50:50 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 96AADAD0B; Thu, 26 Mar 2020 09:50:49 +0000 (UTC) To: Andrew Cooper References: <6fa81b4d-528d-5c33-50c5-a18396b4383a@suse.com> <2c83b876-6fd8-1315-3b28-b45e877187aa@suse.com> <7147e3a1-b237-7a2b-d623-b364704d0096@citrix.com> From: Jan Beulich Message-ID: Date: Thu, 26 Mar 2020 10:50:48 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <7147e3a1-b237-7a2b-d623-b364704d0096@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Xen-devel] [PATCH v5 03/10] x86: determine HAVE_AS_* just once X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Ian Jackson , George Dunlap , Anthony PERARD , "xen-devel@lists.xenproject.org" , Roger Pau Monne Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 25.03.2020 22:12, Andrew Cooper wrote: > On 24/03/2020 12:33, Jan Beulich wrote: >> With the exception of HAVE_AS_QUOTED_SYM, populate the results into a >> generated header instead of (at least once per [sub]directory) into >> CFLAGS. This results in proper rebuilds (via make dependencies) in case >> the compiler used changes between builds. It additionally eases >> inspection of which assembler features were actually found usable. >> >> Some trickery is needed to avoid header generation itself to try to >> include the to-be/not-yet-generated header. >> >> Since the definitions in generated/config.h, previously having been >> command line options, might even affect xen/config.h or its descendants, >> move adding of the -include option for the latter after inclusion of the >> per-arch Rules.mk. Use the occasion to also move the most general -I >> option to the common Rules.mk. >> >> Signed-off-by: Jan Beulich > > Given the work of Anthony's which is already committed in staging, I'd > really prefer this patch to look something like > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=WIP.x86/asm&id=95ef9f80ed6359e89f988121521c421b7e9528de > > That avoids all fragile games with includes, and is the position we want > to be in, longterm. Ah, so they already have something going in that direction. Looks okay to me, albeit ... > All the requisite infrastructure looks to be already present. ... there's the one open prereq question of what happens upon tool chain updates. It's not clear to me if/how kconfig would get invoked despite none of the recorded dependencies having changed in such a case. (I'm sure you realize there's no issue with this when the determination occurs out of a makefile.) Jan