On Thu, Jul 20, 2017 at 04:57:29PM +0200, Eduardo Otubo wrote: > Compilation breaks on GCC 7.1.1 20170622 (Fedora 26), thus adding > -Wno-format-truncation to QEMU_CFLAGS on configure script is neecssary. > > hw/usb/bus.c: In function ‘usb_port_location’: > hw/usb/bus.c:410:66: error: ‘%d’ directive output may be truncated > writing between 1 and 11 bytes into a region of size between 0 and 15 > [-Werror=format-truncation=] > snprintf(downstream->path, sizeof(downstream->path), "%s.%d", > ^~ > In file included from /usr/include/stdio.h:939:0, > from > /home/otubo/develop/qemu/otubo/include/qemu/osdep.h:68, > from hw/usb/bus.c:1: > /usr/include/bits/stdio2.h:64:10: note: ‘__builtin___snprintf_chk’ output > between 3 and 28 bytes into a destination of size 16 > return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > __bos (__s), __fmt, __va_arg_pack ()); > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > make: *** [/home/otubo/develop/qemu/otubo/rules.mak:66: hw/usb/bus.o] > Error 1 > make: *** Waiting for unfinished jobs.... > > Signed-off-by: Eduardo Otubo <ot...@redhat.com> > --- > This warning looks pretty much bogus to me. Since building with -Werror is > essential, we should add this flag to configure. If someone thinks this > warning > is not a false positive, feel free to drop this patch.
This particular case of the warning may be a false positive, but the -Wformat-truncation warning *can* detect serious real bugs so turning it off is not appropriate. In any case there's a patch this problem queued for merge already: https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg06455.html Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|