Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread Markus Armbruster
Paolo Bonzini writes: > On 02/02/2016 22:59, Eric Blake wrote: >> I'd be okay with this patch, if you want to make it a formal >> submission, and if no one else chimes in with any opinion other >> than disgust at clang's shenanigans. > > I'm not okay with the patch. What's wrong with > -fno-sani

Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread Markus Armbruster
Laszlo Ersek writes: > On 02/02/16 21:03, John Snow wrote: >> Recently, qemu iotest 013 has started to fail for me: >> >> Fedora release 22 (Twenty Two) >> >> 3.5.0-9.fc22 >> clang version 3.5.0 (tags/RELEASE_350/final) >> Target: x86_64-redhat-linux-gnu >> Thread model: posix >> >> >> +4 KiB

Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread Paolo Bonzini
On 02/02/2016 22:59, Eric Blake wrote: > I'd be okay with this patch, if you want to make it a formal > submission, and if no one else chimes in with any opinion other > than disgust at clang's shenanigans. I'm not okay with the patch. What's wrong with -fno-sanitize=float-divide-by-zero? GCC

Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread Laszlo Ersek
On 02/02/16 23:00, John Snow wrote: > > > On 02/02/2016 04:47 PM, Laszlo Ersek wrote: >> On 02/02/16 21:03, John Snow wrote: >>> Recently, qemu iotest 013 has started to fail for me: >>> >>> Fedora release 22 (Twenty Two) >>> >>> 3.5.0-9.fc22 >>> clang version 3.5.0 (tags/RELEASE_350/final) >>> T

Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread John Snow
On 02/02/2016 04:47 PM, Laszlo Ersek wrote: > On 02/02/16 21:03, John Snow wrote: >> Recently, qemu iotest 013 has started to fail for me: >> >> Fedora release 22 (Twenty Two) >> >> 3.5.0-9.fc22 >> clang version 3.5.0 (tags/RELEASE_350/final) >> Target: x86_64-redhat-linux-gnu >> Thread model: po

Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread Eric Blake
On 02/02/2016 01:03 PM, John Snow wrote: > The problem is that in the print report for read_f, t2 and t1 can > actually be the same exact timestamp, and tdiv will try to divide by 0.0. > > Normally this is not a problem as this is defined to be INFINITY in C99 > Annex F. > > Clang, however, has

Re: [Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread Laszlo Ersek
On 02/02/16 21:03, John Snow wrote: > Recently, qemu iotest 013 has started to fail for me: > > Fedora release 22 (Twenty Two) > > 3.5.0-9.fc22 > clang version 3.5.0 (tags/RELEASE_350/final) > Target: x86_64-redhat-linux-gnu > Thread model: posix > > > +4 KiB/home/jsnow/src/qemu/qemu-io-cmds.c:

[Qemu-devel] iotest 013 failure under clang -fsanitize=undefined

2016-02-02 Thread John Snow
Recently, qemu iotest 013 has started to fail for me: Fedora release 22 (Twenty Two) 3.5.0-9.fc22 clang version 3.5.0 (tags/RELEASE_350/final) Target: x86_64-redhat-linux-gnu Thread model: posix +4 KiB/home/jsnow/src/qemu/qemu-io-cmds.c:230:18: runtime error: division by zero The problem is t