Peter Maydell <peter.mayd...@linaro.org> writes: > On Sun, 7 Jul 2019 at 21:26, Stefan Weil <s...@weilnetz.de> wrote: >> This is a general problem all over the QEMU code. I usually compile with >> nearly all warnings enabled and get now lots of errors with the latest >> code and after updating to gcc-8.3.0 (Debian buster). It should be >> reproducible by enabling -Werror=implicit-fallthrough. > > Coverity warns about implicit fallthroughs, and we are > currently warning-free in that department, so I think > our remaining problems are largely down to perhaps > using idioms which the compiler doesn't spot. > Being able to enable gcc implicit-fallthrough errors would > definitely be better than spotting them only after the > fact with Coverity. > >> I suggest to enable -Werror=implicit-fallthrough by default and add a >> new macro to mark all fallthrough locations which are correct, but not >> accepted by the compiler. > > I'm not sure why we need a macro. Our standard way to > mark fallthrough is /* fall through */, which has hundreds > of uses in the codebase. -Wimplicit-fallthrough=2 will match this, > so it seems simpler to just use that rather than to rework > how we mark fallthroughs. > > Since vixl is 3rd-party code it might be easier to just > add -Wno-implicit-fallthrough to the cflags that > disas/libvixl/Makefile.objs sets up for building those files. > (We should check also for newer libvixl and/or suggest > something upstream that works with gcc.)
Concur.
