qapi: Use 'alternate' to replace anonymous union

Previous patches have led up to the point where I create the
new meta-type "'alternate':'Foo'".  See the previous patches
for documentation; I intentionally split as much work into
earlier patches to minimize the size of this patch, but a lot
of it is churn due to testsuite fallout after updating to the
new 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, 11 insertions, 6 deletions

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 6bd2b6b..9222671 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -256,7 +256,7 @@ void visit_type_%(name)s(Visitor *m, %(name)s **obj, const char *name, Error **e
 ''',
     name=name)
 
-    # For anon union, always use the default enum type automatically generated
+    # For alternate, always use the default enum type automatically generated
     # as "'%sKind' % (name)"
     disc_type = '%sKind' % (name)
 
@@ -264,7 +264,7 @@ void visit_type_%(name)s(Visitor *m, %(name)s **obj, const char *name, Error **e
         assert (members[key] in builtin_types.keys()
             or find_struct(members[key])
             or find_union(members[key])
-            or find_enum(members[key])), "Invalid anonymous union member"
+            or find_enum(members[key])), "Invalid alternate member"
 
         enum_full_value = generate_enum_full_value(disc_type, key)
         ret += mcgen('''
@@ -300,10 +300,6 @@ def generate_visit_union(expr):
     base = expr.get('base')
     discriminator = expr.get('discriminator')
 
-    if discriminator == {}:
-        assert not base
-        return generate_visit_alternate(name, members)
-
     enum_define = discriminator_find_enum_define(expr)
     if enum_define:
         # Use the enum type as discriminator
@@ -568,6 +564,15 @@ for expr in exprs:
                                      expr['data'].keys())
         ret += generate_declaration(expr['union'], expr['data'])
         fdecl.write(ret)
+    elif expr.has_key('alternate'):
+        ret = generate_visit_alternate(expr['alternate'], expr['data'])
+        ret += generate_visit_list(expr['alternate'], expr['data'])
+        fdef.write(ret)
+
+        ret = generate_decl_enum('%sKind' % expr['alternate'],
+                                 expr['data'].keys())
+        ret += generate_declaration(expr['alternate'], expr['data'])
+        fdecl.write(ret)
     elif expr.has_key('enum'):
         ret = generate_visit_list(expr['enum'], expr['data'])
         ret += generate_visit_enum(expr['enum'], expr['data'])