qapi: Segregate anonymous unions into alternates in generator

Special-casing 'discriminator == {}' for handling anonymous unions
is getting awkward; since this particular type is not always a
dictionary on the wire, it is easier to treat it as a completely
different class of type, "alternate", so that if a type is listed
in the union_types array, we know it is not an anonymous union.

This patch just further segregates union handling, to make sure that
anonymous unions are not stored in union_types, and splitting up
check_union() into separate functions.  A future patch will change
the qapi grammar, and having the segregation already in place will
make it easier to deal with the distinct meta-type.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index dbf0101..6bd2b6b 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -237,7 +237,7 @@ void visit_type_%(name)s(Visitor *m, %(name)s *obj, const char *name, Error **er
 ''',
                  name=name)
 
-def generate_visit_anon_union(name, members):
+def generate_visit_alternate(name, members):
     ret = mcgen('''
 
 void visit_type_%(name)s(Visitor *m, %(name)s **obj, const char *name, Error **errp)
@@ -302,7 +302,7 @@ def generate_visit_union(expr):
 
     if discriminator == {}:
         assert not base
-        return generate_visit_anon_union(name, members)
+        return generate_visit_alternate(name, members)
 
     enum_define = discriminator_find_enum_define(expr)
     if enum_define: