X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:subject:to:message-id:date:mime-version
	:content-type:content-transfer-encoding; q=dns; s=default; b=pBe
	e++TeeYM6j8P42spF594HKpzNiPLXwy5JtePzZ3YKkeE13riLiShoXjW4FoIIbsW
	SYRynIzOpDp0tBuse5L4aHRbIQ3lwE5s1E3AabQAfTPqv3CSX0F4r/QqT5SIiB1s
	ukK78kTeHriI2vVBPqIPk259G/rEByHWIU0vvfRw=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:subject:to:message-id:date:mime-version
	:content-type:content-transfer-encoding; s=default; bh=6k/DN6dfT
	7Z2Fzri3PraQxJ9K4c=; b=tSQQs6DvvvCcGXulV6OgKVaQEKIP4p8d0sWPnPfoG
	OoBWKM/uTk0MJFCXBxnZfU1xPsXZTwqNVcUU/eWhvoBhPt2BC+Dl+qIpyjdfGRSJ
	1F6JOKqlqUesZW3Vg61BWdHgRU9wNlf8X+rS+77vKZIfBJ913r3nqmRw/zBkM7Mo
	Uo=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-3.6 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=H*MI:online, H*M:online, upgrading
X-HELO: mailout09.t-online.de
From: Christian Franke <Christian DOT Franke AT t-online DOT de>
Subject: gcc-6.3.0-1 regression: libstdc++6 DLL breaks exception handling
To: cygwin AT cygwin DOT com
Message-ID: <6a80a46a-8de9-5d28-f7ef-897a53159603@t-online.de>
Date: Thu, 26 Jan 2017 11:30:43 +0100
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0 SeaMonkey/2.47
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
X-IsSubscribed: yes

After upgrading to gcc test version 6.3.0-1, C++ exception handling is 
broken if DLL version of new libstdc++6 is used.

Testcase:

$ uname -srvmo
CYGWIN_NT-10.0-WOW 2.6.1(0.305/5/3) 2016-12-16 11:50 i686 Cygwin
or:
CYGWIN_NT-10.0 2.6.1(0.305/5/3) 2016-12-16 11:55 x86_64 Cygwin

$ cygcheck -f /bin/g++
gcc-g++-6.3.0-1

$ cygcheck -f /bin/cygstdc++-6.dll
libstdc++6-6.3.0-1

$ cat exc.cc
int main()
{
   try {
     throw 42;
   }
   catch (int i) {
     return i;
   }
   return 0;
}

$ g++ -o exc exc.cc

$ ./exc
Segmentation fault (core dumped)


Workaround: Use statically linked version of new libstdc++6:

$ g++ -static -o exc-static exc.cc

$ ./exc-static

$ echo $?
42


Or: Downgrade cygstdc++6.dll:

$ cygcheck -f /bin/cygstdc++-6.dll
libstdc++6-5.4.0-1

$ ./exc

$ echo $?
42


This also affects existing packages compiled with older g++, for example:

$ /usr/sbin/smartctl -V
smartctl 6.5 2016-05-07 r4318 [x86_64-unknown-cygwin-win10] (cygwin-6.5-1)
...
smartmontools build with: C++98, GCC 5.3.0
...
Segmentation fault (core dumped)


Regards,
Christian


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple