@@ -123,11 +123,9 @@ And it looks like this on the wire:
Flat union types avoid the nesting on the wire. They are used whenever a
specific field of the base type is declared as the discriminator ('type' is
-then no longer generated). The discriminator can be a string field or a
-predefined enum field. If it is a string field, a hidden enum type will be
-generated as "[UNION_NAME]Kind". If it is an enum field, a compile time check
-will be done to verify the correctness. It is recommended to use an enum field.
-The above example can then be modified as follows:
+then no longer generated). The discriminator should be a predefined enum field,
+and a compile time check will be done to verify the correctness. The above
+example can then be modified as follows:
{ 'enum': 'BlockdevDriver', 'data': [ 'raw', 'qcow2' ] }
{ 'type': 'BlockdevCommonOptions',
@@ -280,6 +280,12 @@ def generate_visit_union(expr):
# Use the predefined enum type as discriminator
ret = ""
discriminator_type_name = enum_define['enum_name']
+ elif discriminator:
+ # Do not allow string discriminator
+ sys.stderr.write("Discriminator '%s' is not a pre-defined enum "
+ "type\n" %
+ discriminator)
+ sys.exit(1)
else:
# There will always be a discriminator in the C switch code, by default it
# is an enum type generated silently as "'%sKind' % (name)"
Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> --- docs/qapi-code-gen.txt | 8 +++----- scripts/qapi-visit.py | 6 ++++++ 2 files changed, 9 insertions(+), 5 deletions(-)