From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by sourceware.org (Postfix) with ESMTPS id 34255384A026 for ; Wed, 22 Apr 2020 21:17:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 34255384A026 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 03MLCPEM015070; Wed, 22 Apr 2020 17:17:21 -0400 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0a-001b2d01.pphosted.com with ESMTP id 30jrj621kd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 22 Apr 2020 17:17:21 -0400 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id 03MLFLPa028387; Wed, 22 Apr 2020 21:17:20 GMT Received: from b01cxnp23033.gho.pok.ibm.com (b01cxnp23033.gho.pok.ibm.com [9.57.198.28]) by ppma02dal.us.ibm.com with ESMTP id 30fs675j12-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 22 Apr 2020 21:17:20 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 03MLHKEH50332020 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 22 Apr 2020 21:17:20 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 08A09AE05F; Wed, 22 Apr 2020 21:17:20 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C1F89AE05C; Wed, 22 Apr 2020 21:17:19 +0000 (GMT) Received: from [9.85.144.164] (unknown [9.85.144.164]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 22 Apr 2020 21:17:19 +0000 (GMT) Subject: Re: [PATCH v3 1/6] ldbl-128ibm-compat: workaround GCC 9 C++ BZ 90731 To: Florian Weimer , "Paul E. Murphy via Libc-alpha" References: <87zhb3imh4.fsf@mid.deneb.enyo.de> From: Paul E Murphy Message-ID: <4f8dcbea-1485-3d3c-b896-8da95a90de4e@linux.ibm.com> Date: Wed, 22 Apr 2020 16:17:19 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <87zhb3imh4.fsf@mid.deneb.enyo.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.676 definitions=2020-04-22_06:2020-04-22, 2020-04-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 spamscore=0 malwarescore=0 mlxscore=0 lowpriorityscore=0 priorityscore=1501 adultscore=0 mlxlogscore=999 phishscore=0 suspectscore=0 clxscore=1015 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004220156 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_NUMSUBJECT, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Apr 2020 21:17:25 -0000 On 4/22/20 10:11 AM, Florian Weimer wrote: > * Paul E. Murphy via Libc-alpha: > >> GCC 9 has a bug (BZ 90731) whereby __typeof does not correctly copy >> exception specifiers[1]. Surprisingly, this can be quieted by declaring >> "#pragma system_header", or if the headers are installed in a system >> directory. > > I think GCC developers prefer “PR90731” to their bugs. This occurs > multiple times in the commit message and throughout the patch. Ack. Will fix here and in the subsequent patches too. > > This change will still cause errors with -Wsystem-headers in the build > flags, right? I think we should mention this somewhere, maybe on the > release wiki? > Unfortunately, ppc64le glibc will fail to build with GCC 9.2.0 with this option irrespective of this feature. Though, you are correct the redirects will generate additional warnings when used with such toolchains. Likewise, --disable-werror does avoid breaking things when using -Wsystem-headers. The warnings are not fatal. I suspect the -Wsystem-headers will cause some noise for most users with GCC 8/9 and likely others. I can add a note, but I suspect I will need to be granted wiki editing privileges.