The discriminator for anonymous unions is the data type. This allows to
have a union type that allows both of these:
{ 'file': 'my_existing_block_device_id' }
{ 'file': { 'filename': '/tmp/mydisk.qcow2', 'read-only': true } }
Unions like this are specified in the schema with an empty dict as
discriminator. For this example you could take:
{ 'union': 'BlockRef',
'discriminator': {},
'data': { 'definition': 'BlockOptions',
'reference': 'str' } }
{ 'type': 'ExampleObject',
'data: { 'file': 'BlockRef' } }
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
These can be used when an embedded struct is parsed and members not
belonging to the struct may be present in the input (e.g. parsing a
flat namespace QMP union, where fields from both the base and one
of the alternative types are mixed in the JSON object)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
With the introduction of native list types, we now have types such as
int64List where the 'value' field is not a pointer, but the actual
64-bit value.
On 32-bit architectures, this can lead to situations where 'next' field
offset in GenericList does not correspond to the 'next' field in the
types that we cast to GenericList when using the visit_next_list()
interface, causing issues when we attempt to traverse linked list
structures of these types.
To fix this, pad the 'value' field of GenericList and other
schema-defined/native *List types out to 64-bits.
This is less memory-efficient for 32-bit architectures, but allows us to
continue to rely on list-handling interfaces that target GenericList to
simply visitor implementations.
In the future we can improve efficiency by defaulting to using native C
array backends to handle list of non-pointer types, which would be more
memory efficient in itself and allow us to roll back this change.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
