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

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 22 Oct 2010 22:49:10 +0200
Stefan Weil <weil@mail.berlios.de> wrote:

> Am 22.10.2010 19:33, schrieb Luiz Capitulino:
> > 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.
> >    
> 
> 
> If needed, commit 8b7968f7c4ac8c07cad6a1a0891d38cf239a2839
> can be reverted partially (only for qjson.h).
> 
> Tell me if you would prefer that solution, then I can send a patch.

Well, the warning seems useful to me. It's the error checking test suite
that's triggering it.

Jan's fix looks file to me.