Re: [Qemu-devel] [RFC] Fixing the error failure

[Anthony Liguori]

On 06/26/2012 06:21 AM, Markus Armbruster wrote:
> "Daniel P. Berrange"<address@hidden>  writes:
>
> > On Tue, Jun 26, 2012 at 09:54:21AM +0200, Markus Armbruster wrote:
> > > Luiz Capitulino<address@hidden>  writes:
> > >
> > > > On Thu, 21 Jun 2012 13:42:19 +0100
> > > > "Daniel P. Berrange"<address@hidden>  wrote:
> [...]
> > > > > In libvirt we have always reserved the right to change the error
> > > > > code reported for particular scenarios. So, for example, alot of
> > > > > our errors started out as "InternalError" (equiv to UndefinedError)
> > > > > but over time we have changed some to more specialized values
> > > > > eg "InvalidOperation", "ConfigNotSupported" and so on.
> > >
> > > Do you reserve the right to make changes other than from InternalError
> > > to a more specific one?
> >
> > If I'm perfectly honest, then yes. We have tried not to gratuitouslyy
> > change errors being reported, but they have definitely evolved over
> > time, so more distinct error scenarios are reported, where previously
> > many things would have been lumped under one code.
>
> Pragmatic co-evolution of errors with their actual use.  Makes sense to
> me, and I'd recommend we do the same in QEMU.

Just to be clear, what we're discussing is:

> diff --git a/qerror.c b/qerror.c
> index 92c4eff..ebe2eb0 100644
> --- a/qerror.c
> +++ b/qerror.c
> @@ -328,6 +328,10 @@ static const QErrorStringTable qerror_table[] = {
>          .error_fmt = QERR_SOCKET_CREATE_FAILED,
>          .desc      = "Failed to create socket",
>      },
> +    {
> +        .error_fmt = QERR_UNDEFINED_ERROR,
> +        .desc      = "Undefined Error: %(message)",
> +    },
>      {}
>  };
>
> diff --git a/qerror.h b/qerror.h
> index b4c8758..da8f086 100644
> --- a/qerror.h
> +++ b/qerror.h
> @@ -266,4 +266,7 @@ QError *qobject_to_qerror(const QObject *obj);
>  #define QERR_SOCKET_CREATE_FAILED \
>      "{ 'class': 'SockCreateFailed', 'data': {} }"
>
> +#define QERR_UNDEFINED_ERROR \
> +    "{ 'class': 'UndefinedError', 'data': { 'message': %s } }"
> +
>  #endif /* QERROR_H */

Nothing more, nothing less.  No changes to wire protocol, no changes to existing 
error uses, etc.

Regards,

Anthony Liguori

> [...]