[libvirt] API break from the VMware player driver

[Matthias Bolte]

2010/12/21 Eric Blake <eblake at redhat.com>:
> On 12/21/2010 11:34 AM, Chris Lalancette wrote:
>> All,
>>      I'll preface this by saying that I'm not 100% sure I'm correct.  But I
>> still think there may be an API break that was introduced with the VMware
>> player driver.  In include/libvirt/virterror.h, VIR_FROM_VMWARE was added to
>> the *middle* of the enum for virErrorDomain.  If any clients of libvirt happen
>> to be using hardcoded numbers, then they will now have the wrong number for
>> everything after VIR_FROM_VMWARE.
>
> virterror.h is public, we should fix it now before the next release,
> because these values are passed over the wire in RPC calls, and if the
> server on one machine uses different values than the client on another
> machine, then the client can misinterpret the error values.
>

We might explicit write out all values of the enum members. That'll
make it more obvious that adding in the middle is a bad idea.

Can we add a make syntax-check rule to avoid future breakage, like we
have for the XDR protocol?

PS: Sorry, for not noticing this during review of the VMware driver.

Matthias