Re: [Qemu-devel] What's IOMMUMemoryRegion's super?

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> On 03/07/19 07:05, Markus Armbruster wrote:
>>     static const TypeInfo iommu_memory_region_info = {
>>         .parent             = TYPE_MEMORY_REGION,
>>         .name               = TYPE_IOMMU_MEMORY_REGION,
>>         .class_size         = sizeof(IOMMUMemoryRegionClass),
>>         .instance_size      = sizeof(IOMMUMemoryRegion),
>>         .instance_init      = iommu_memory_region_initfn,
>>         .abstract           = true,
>>     };
>> 
>>     typedef struct IOMMUMemoryRegionClass {
>>         /* private */
>> --->    struct DeviceClass parent_class;
>>         [...]
>>     };
>> 
>>     struct IOMMUMemoryRegion {
>>         MemoryRegion parent_obj;
>>         [...]
>>     };
>> 
>> The parent is TYPE_MEMORY_REGION, and the instance struct's first member is
>> TYPE_MEMORY_REGION's instance struct as I expect, but the class struct's
>> first member is something else entirely.
>
> Cut-and-paste error.  MemoryRegion adds no methods so that could be

I wonder whether there's anything we could do to catch such errors
automatically.

> either ObjectClass or better
>
>     typedef struct MemoryRegionClass {
>         /* private */
>         ObjectClass parent_class;
>     } ObjectClass;

I'll prepare the patch.  Thanks!