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

[Paolo Bonzini]

On 10/19/2009 06:50 PM, Hollis Blanchard wrote:
> On Sun, 2009-10-18 at 14:17 +0200, Paolo Bonzini wrote:
> > On 10/18/2009 06:25 AM, Jamie Lokier wrote:
> > > The manual for GNU gettext explains quite well why gettext takes a
> > > message string as argument, instead of a "message code".  Imho, a
> > > similar case can be made for error messages at call sites.
> >
> > That's true.  However here we have the case of having errors consumed by
> > programs as well as users, so we want something that can be easily made
> > into language bindings.
> >
> > In other words, this situation is much more similar to errno/strerror,
> > than to a compiler error message (which will often be used by other
> > programs, but where the actual error text will be read by a person; this
> > can and should use gettext).
>
> So to extend your analogy, I think we're reaching the conclusion that
> both errno *and* string should be returned to the client, right?

I'd say so, yes.  And any parameters too, all as JSON.  I think errno is 
just one kind of data that can be in an exception, and you want 
different exceptions for not opening a sound device or not opening an 
image file (even if both may fail with EACCES or ENOENT).

Paolo