Re: [Qemu-devel] [PATCH 2/4] Silence compiler warning in json test case

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 22 Oct 2010 19:15:07 +0200
Markus Armbruster <armbru@redhat.com> wrote:

> Luiz Capitulino <lcapitulino@redhat.com> writes:
> 
> > From: Jan Kiszka <jan.kiszka@web.de>
> >
> > This avoids
> >
> >     error: zero-length gnu_printf format string
> >
> > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > ---
> >  check-qjson.c |    4 +++-
> >  1 files changed, 3 insertions(+), 1 deletions(-)
> >
> > diff --git a/check-qjson.c b/check-qjson.c
> > index 0b60e45..64fcdcb 100644
> > --- a/check-qjson.c
> > +++ b/check-qjson.c
> > @@ -639,7 +639,9 @@ END_TEST
> >  
> >  START_TEST(empty_input)
> >  {
> > -    QObject *obj = qobject_from_json("");
> > +    const char *empty = "";
> > +
> > +    QObject *obj = qobject_from_json(empty);
> >      fail_unless(obj == NULL);
> >  }
> >  END_TEST
> 
> The warning is silly.  Printing nothing is unlikely to happen
> unintentionally, and is perfectly well-defined and portable.
> 
> Why make the code ugly to avoid a useless warning, when we can disable
> the warning?

You mean, disable it only for this specific case or QEMU wide?

If it's the former, please, submit a patch. Otherwise, this has been
discussed already and the conclusion was that the warning is
useful:

 http://www.mail-archive.com/qemu-devel@nongnu.org/msg44072.html

Honestly speaking, no matter what the conclusion is, what can not
happen is having code that doesn't compile in the tree. Either: we apply
this patch or revert the patch that broke the build.