Re: [Qemu-devel] [PATCH v16 02/24] qapi: Guarantee NULL obj on input visitor callback error

[Eric Blake]

On 04/29/2016 02:28 AM, Markus Armbruster wrote:
> Eric Blake <address@hidden> writes:
> 
>> Our existing input visitors were not very consistent on errors
>> in a function taking 'TYPE **obj' (that is, start_struct(),
>> start_alternate(), type_str(), and type_any(). next_list() is
>> similar, except that since commit 08f9541, it can't fail).
> 
> Multiple sentences in a parenthesis, ugh :)
> 
>     Our existing input visitors were not very consistent on errors in a
>     function taking 'TYPE **obj'.  These are start_struct(),
>     start_alternate(), type_str(), and type_any().  next_list() is
>     similar, but can't fail (see commit since 08f9541).
> 
> Can touch up on commit.
> 

Yes, sounds better.


>> @@ -51,10 +57,16 @@ void visit_start_alternate(Visitor *v, const char *name,
>>                             GenericAlternate **obj, size_t size,
>>                             bool promote_int, Error **errp)
>>  {
>> +    Error *err = NULL;
>> +
>>      assert(obj && size >= sizeof(GenericAlternate));
>>      if (v->start_alternate) {
>> -        v->start_alternate(v, name, obj, size, promote_int, errp);
>> +        v->start_alternate(v, name, obj, size, promote_int, &err);
>>      }
>> +    if (v->type == VISITOR_INPUT) {
>> +        assert(!err != !*obj);
> 
> Could assert(v->start_alternate && !err != !*obj), to preempt "what if
> !v->start_alternate" worries.  If you like that, I can do it on commit.

Can't hurt :)

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

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