From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id C45E7A046B for ; Tue, 23 Jul 2019 15:18:41 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 3DEB01C01F; Tue, 23 Jul 2019 15:18:41 +0200 (CEST) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id DFD561C01E for ; Tue, 23 Jul 2019 15:18:39 +0200 (CEST) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Jul 2019 06:18:39 -0700 X-IronPort-AV: E=Sophos;i="5.64,299,1559545200"; d="scan'208";a="344737446" Received: from bricha3-mobl.ger.corp.intel.com ([10.237.221.51]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 Jul 2019 06:18:37 -0700 Date: Tue, 23 Jul 2019 14:18:34 +0100 From: Bruce Richardson To: Krzysztof Kanas Cc: "dev@dpdk.org" , Thomas Monjalon , "reshma.pattan@intel.com" Message-ID: <20190723131834.GB1603@bricha3-MOBL.ger.corp.intel.com> References: <20190722123959.29703-1-kkanas@marvell.com> <20190722134416.GB289@bricha3-MOBL.ger.corp.intel.com> <20190723090548.GA32530@kk-box-0> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190723090548.GA32530@kk-box-0> User-Agent: Mutt/1.11.4 (2019-03-13) Subject: Re: [dpdk-dev] [EXT] Re: [PATCH] mk: disable flag for no packet member warning X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Jul 23, 2019 at 09:05:50AM +0000, Krzysztof Kanas wrote: > On 19-07-22 14:44, Bruce Richardson wrote: > > External Email > > > > ---------------------------------------------------------------------- > > On Mon, Jul 22, 2019 at 02:39:59PM +0200, kkanas@marvell.com wrote: > > > From: Krzysztof Kanas > > > > > > gcc prior 9 don't will add additional warning for unrecognized command > > > line option, but only when there is some other warning in the code, e.g > > > unused variable. > > > > > I don't think this behaviour has changed in gcc 9. I just did a test > > compile with gcc 9.1, and no warning was printed for flag > > "-Wno-random-warnings". The online docs also make no mention of this > > behaviour being conditional on GCC version [1]. > GCC changelog show that from 9.0 -Waddress-of-packed-member was added > [1]. > > Test shows me that GCC prior to 9.0 won't complain about this flag, but > in case of other warnings in file GCC will complain, e.g., > > cat > a.c > int main(int argc, char **argv) > { > int a; > return 0; > } > > # gcc -Wall -Wno-address-of-packed-member a.c > > a.c: In function ‘main’: > a.c:3:6: warning: unused variable ‘a’ [-Wunused-variable] > int a; > ^ > a.c: At top level: > cc1: warning: unrecognized command line option ‘-Wno-address-of-packed-member’ > > But when line `int a;' is removed then no warning is issued. > > Also I detected this, due to difference with meson build. Meson checks > if compiler supports this flag and will not issue > -Wno-address-of-packed-member to compiler. > Yes, all that is correct, but there is no behaviour change in GCC 9. This does not require a fix IMHO. /Bruce