Re: [Qemu-block] [Qemu-devel] [RFC v2 for-2.9 07/10] sockets: New helper socket_address_crumple()

[Eric Blake]

On 03/30/2017 10:03 AM, Markus Armbruster wrote:

>>> +SocketAddress *socket_address_crumple(SocketAddressFlat *addr_flat)
>>> +{
>>> +    SocketAddress *addr = g_new(SocketAddress, 1);
>>> +
>>> +    addr->type = addr_flat->type;
>>
>> Works only because our enum is defined in the same order as the simple
>> union's members.  A bit fragile, so maybe we want to comment in the
>> .json file that we can't reorder members of either the enum or the
>> simple union's 'data'?  Or it might even tickle a picky compiler to warn
>> about assignment between incompatible enum types.  Another option would
>> be making it robust by instead doing switch(addr_flat->type) and
>> assigning to addr->type in each branch of the switch.
> 
> Sold.
> 

> Now looks like this:
> 
> SocketAddress *socket_address_crumple(SocketAddressFlat *addr_flat)
> {
>     SocketAddress *addr = g_new(SocketAddress, 1);
> 
>     switch (addr_flat->type) {
>     case SOCKET_ADDRESS_FLAT_TYPE_INET:
>         addr->type = SOCKET_ADDRESS_KIND_INET;
>         addr->u.inet.data = QAPI_CLONE(InetSocketAddress,
>                                        &addr_flat->u.inet);
>         break;

Yes, that's better, and no tweaks to the .json file needed.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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