Re: [libvirt] API break from the VMware player driver
On Tue, Dec 21, 2010 at 08:50:04PM +0100, Matthias Bolte wrote:
2010/12/21 Eric Blake <eblake(a)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,
Absolutely !
BTW I will send a mail about next release suggestion later today, now that
my move is over and I'm back online.
> 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.
agreed too,
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.
Well it happens, but yes an automated extra check for all enums in
the public APIs would be good, I think this could be also managed with
libvirt-api.xml extracted values, assuming we put the numbers in.
Daniel
--
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