qapi script: do not allow string discriminator
Since enum based discriminators provide better type-safety and
ensure that future qapi additions do not forget to adjust dependent
unions, forbid using string as discriminator from now on.
Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 2b43ad2..bd00d01 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -239,6 +239,11 @@
"type '%s'"
% (discriminator, base))
enum_define = find_enum(discriminator_type)
+ # Do not allow string discriminator
+ if not enum_define:
+ raise QAPIExprError(expr_info,
+ "Discriminator '%s' must be of enumeration "
+ "type" % discriminator)
# Check every branch
for (key, value) in members.items():