Re: [Qemu-devel] [RFC PATCH v2 21/21] ui/vnc: silent unuseful OSX clang warning

[Gerd Hoffmann <kraxel@redhat.com>]

On Thu, 2017-06-22 at 08:35 +0100, Peter Maydell wrote:
> On 22 June 2017 at 08:33, Gerd Hoffmann <kraxel@redhat.com> wrote:
> > diff --git a/ui/Makefile.objs b/ui/Makefile.objs
> > > index 3369451285..08fb573a48 100644
> > > --- a/ui/Makefile.objs
> > > +++ b/ui/Makefile.objs
> > > @@ -6,6 +6,14 @@ vnc-obj-y += vnc-auth-vencrypt.o
> > >  vnc-obj-$(CONFIG_VNC_SASL) += vnc-auth-sasl.o
> > >  vnc-obj-y += vnc-ws.o
> > >  vnc-obj-y += vnc-jobs.o
> > > +ifeq ($(CONFIG_VNC_SASL),y)
> > > +# silent OSX SASL warnings (from https://stackoverflow.com/a/740
> > > 6994
> > > ):
> > > +# because OpenSSL doesn’t offer API compatibility between
> > > versions,
> > > [...] Apple
> > > +# can't provide security updates without breaking existing apps,
> > > so
> > > is migrating
> > > +# from OpenSSL to Common Crypto.
> > > +vnc.o-cflags := -Wno-deprecated-declarations
> > > +vnc-auth-sasl.o-cflags := -Wno-deprecated-declarations
> > > +endif
> > 
> > Hmm, does clang understand "#pragma GCC diagnostic" ?
> > 
> > If so, then this can be done in in the code not the makefiles, and
> > also
> > selectively for osx only.
> 
> It does have some diagnostic pragma support. The awkward part is
> that it has to  be in force at the point where the deprecated
> function is used, not where it's declared. So you can't just wrap
> the #include of the ssl header in pragmas, you'd have to either
> do it at every callsite or else over the whole .c file.

Do it on the whole file on osx only is still better because we continue
to get the warnings on non-osx then, which should be enough to avoid
the code bitroting unnoticed.

cheers,
  Gerd