Re: [PATCH 2/2] Add warn_unused_result attr to AUD_register_card

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Nov 10, 2023 at 11:18:39AM +0000, Peter Maydell wrote:
> On Fri, 10 Nov 2023 at 11:02, Manos Pitsidianakis
> <manos.pitsidianakis@linaro.org> wrote:
> >
> > On Fri, 10 Nov 2023 12:21, Peter Maydell <peter.maydell@linaro.org> wrote:
> > >This kind of thing is why Coverity's unused-result warning has a
> > >lot of false positives. We shouldn't introduce extra code like
> > >this to work around the fact that the tooling doesn't understand
> > >our error-handling convention (i.e. error_fatal, and the way
> > >that some functions report errors both via the return value and
> > >also via the Error** argument).
> >
> > I respect that :). But I personally believe that clinging to C's
> > inadequacies, instead of preventing bugs statically just because it adds
> > some lines of code, is misguided. Proper code should strive to make bugs
> > impossible in the first place.
> 
> I generally agree. The problem here really is that we've ended
> up with this odd API convention that reports errors in two
> ways. In an ideal world we'd tidy up our APIs to report errors
> exactly in one way (presumably via the Error).

The compelling thing about our slightly odd &error_fatal/error_abort
approach is that we can directly get stack traces showing exactly
where the error happened.

If we just propagate the error up the stack to finally exit/abort,
the origin context is essentially lost, and when it does abort, we
don't get a snapshot of all threads at the time the error hit, as
we've moved on in time.


With 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 :|