From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38682) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZGVb-00086J-MQ for qemu-devel@nongnu.org; Tue, 18 Dec 2018 09:38:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZGVZ-0005ud-SS for qemu-devel@nongnu.org; Tue, 18 Dec 2018 09:38:07 -0500 Date: Tue, 18 Dec 2018 14:36:48 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20181218143648.GA4807@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20181218110333.22558-1-philmd@redhat.com> <20181218092648-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181218092648-mutt-send-email-mst@kernel.org> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 0/3] Fix strncpy() warnings for GCC8 new -Wstringop-truncation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Ben Pye , Stefan Weil , Howard Spoelstra , Jeff Cody , =?utf-8?Q?C=C3=A9dric?= Le Goater , Thomas Huth , Liu Yuan , Igor Mammedov , Max Reitz , Kevin Wolf , Eric Blake , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , David Hildenbrand , David Gibson , Markus Armbruster , qemu-block@nongnu.org, "Dr. David Alan Gilbert" , 1803872@bugs.launchpad.net, Juan Quintela , Paolo Bonzini On Tue, Dec 18, 2018 at 09:31:00AM -0500, Michael S. Tsirkin wrote: > On Tue, Dec 18, 2018 at 12:03:30PM +0100, Philippe Mathieu-Daud=C3=A9 w= rote: > > GCC 8 new warning prevents builds to success since quite some time. > > First report on the mailing list is in July 2018: > > https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg03723.html > >=20 > > Various intents has been sent to fix this: > > - Incorrectly using g_strlcpy() > > https://lists.gnu.org/archive/html/qemu-devel/2018-08/msg03705.html > > https://lists.gnu.org/archive/html/qemu-devel/2018-08/msg03706.html > > - Using assert() and strpadcpy() > > https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg03938.html > > - Use #pragma GCC diagnostic ignored "-Wstringop-truncation" > > https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg04261.html > > - adding an inline wrapper with said pragma in there > > https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg04261.html > > - -Wno-stringop-truncation is the makefile > > https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg04261.html > >=20 > > This series replace the strncpy() calls by strpadcpy() which seemed > > to me the saniest option. > >=20 > > Regards, > >=20 > > Phil. >=20 > Do you happen to know why does it build fine with > Gcc 8.2.1? >=20 > Reading the GCC manual it seems that > there is a "nostring" attribute that means typo - its "nonstring" > "might not be 0 terminated". > I think we should switch to that which fixes the warning > but also warns if someone tries to misuse these > as C-strings. >=20 > Seems to be a better option, does it not? Yes, it does look best as gcc manual explicitly suggests "nonstring" as the way to stop this strncpy warning. Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|