Re: [Qemu-devel] [PATCH 6/9] QError: Add qdev not found error

[Hollis Blanchard <hollisb@us.ibm.com>]

On Thu, 2009-10-15 at 10:34 -0300, Luiz Capitulino wrote:
> On Wed, 14 Oct 2009 16:02:10 -0700
> Hollis Blanchard <hollisb@us.ibm.com> wrote:
> 
> > On Tue, 2009-10-13 at 13:57 -0300, Luiz Capitulino wrote:
> > > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> > > ---
> > >  qerror.c |   12 ++++++++++++
> > >  qerror.h |    1 +
> > >  2 files changed, 13 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/qerror.c b/qerror.c
> > > index bbea770..88a8208 100644
> > > --- a/qerror.c
> > > +++ b/qerror.c
> > > @@ -24,11 +24,23 @@ static const QType qerror_type = {
> > >      .destroy = qerror_destroy_obj,
> > >  };
> > > 
> > > +static void qemu_err_qdev_nodev(const QError *qerror)
> > > +{
> > > +    QDict *qdict = qobject_to_qdict(qerror->data);
> > > +    qemu_error("Device \"%s\" not found.  Try -device '?' for a list.\n",
> > > +               qdict_get_str(qdict, "name"));
> > > +}
> > > +
> > >  static QErrorTable qerror_table[] = {
> > >      {
> > >          .code   = QERR_UNKNOWN,
> > >          .desc   = "unknown error",
> > >      },
> > > +    {
> > > +        .code   = QERR_QDEV_NFOUND,
> > > +        .desc   = "device not found",
> > > +        .user_print = qemu_err_qdev_nodev,
> > > +    },
> > >  };
> > > 
> > >  /**
> > > diff --git a/qerror.h b/qerror.h
> > > index ed25ef1..820f25e 100644
> > > --- a/qerror.h
> > > +++ b/qerror.h
> > > @@ -21,6 +21,7 @@
> > >   */
> > >  typedef enum QErrorCode {
> > >      QERR_UNKNOWN,
> > > +    QERR_QDEV_NFOUND,
> > >      QERR_MAX,
> > >  } QErrorCode;
> > 
> > I'm not really seeing the point: what is gained by moving the error text
> > from the original site into this function-inside-a-structure?
> 
>  Compatibility and a way of having pretty printing functions w/o
> breaking the machine protocol.

Huh? Compatibility with what? I don't understand this "pretty printing"
comment either.

You could easily have
	qemu_error(code, "device not found");
throughout the code, and transmit that as
	{ "error": { "code": code, "desc": "device not found" } }

-- 
Hollis Blanchard
IBM Linux Technology Center