qapi: Support downstream simple unions

Enhance the testsuite to cover downstream simple unions, including
when a union branch is a downstream name.  Update the generator to
mangle the union names in the appropriate places.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

scripts/qapi-types.py

@@ -193,7 +193,7 @@ const int %(name)s_qtypes[QTYPE_MAX] = {
 
 def generate_union(expr, meta):
 
-    name = expr[meta]
+    name = c_name(expr[meta])
     typeinfo = expr['data']
 
     base = expr.get('base')

scripts/qapi-visit.py

@@ -255,9 +255,9 @@ def generate_visit_union(expr):
         disc_type = enum_define['enum_name']
     else:
         # There will always be a discriminator in the C switch code, by default
-        # it is an enum type generated silently as "'%sKind' % (name)"
-        ret = generate_visit_enum('%sKind' % name, members.keys())
-        disc_type = '%sKind' % (name)
+        # it is an enum type generated silently
+        ret = generate_visit_enum(name + 'Kind', members.keys())
+        disc_type = c_name(name) + 'Kind'
 
     if base:
         assert discriminator
@@ -281,7 +281,7 @@ void visit_type_%(name)s(Visitor *m, %(name)s **obj, const char *name, Error **e
     }
     if (*obj) {
 ''',
-                 name=name)
+                 name=c_name(name))
 
     if base:
         ret += mcgen('''

tests/qapi-schema/qapi-schema-test.json

@@ -114,3 +114,4 @@
   'data': { '__org.qemu_x-member1': '__org.qemu_x-Enum' } }
 { 'struct': '__org.qemu_x-Struct', 'base': '__org.qemu_x-Base',
   'data': { '__org.qemu_x-member2': 'str' } }
+{ 'union': '__org.qemu_x-Union1', 'data': { '__org.qemu_x-branch': 'str' } }

tests/qapi-schema/qapi-schema-test.out

@@ -25,11 +25,13 @@
  OrderedDict([('event', 'EVENT_D'), ('data', OrderedDict([('a', 'EventStructOne'), ('b', 'str'), ('*c', 'str'), ('*enum3', 'EnumOne')]))]),
  OrderedDict([('enum', '__org.qemu_x-Enum'), ('data', ['__org.qemu_x-value'])]),
  OrderedDict([('struct', '__org.qemu_x-Base'), ('data', OrderedDict([('__org.qemu_x-member1', '__org.qemu_x-Enum')]))]),
- OrderedDict([('struct', '__org.qemu_x-Struct'), ('base', '__org.qemu_x-Base'), ('data', OrderedDict([('__org.qemu_x-member2', 'str')]))])]
+ OrderedDict([('struct', '__org.qemu_x-Struct'), ('base', '__org.qemu_x-Base'), ('data', OrderedDict([('__org.qemu_x-member2', 'str')]))]),
+ OrderedDict([('union', '__org.qemu_x-Union1'), ('data', OrderedDict([('__org.qemu_x-branch', 'str')]))])]
 [{'enum_name': 'EnumOne', 'enum_values': ['value1', 'value2', 'value3']},
  {'enum_name': '__org.qemu_x-Enum', 'enum_values': ['__org.qemu_x-value']},
  {'enum_name': 'UserDefAlternateKind', 'enum_values': None},
- {'enum_name': 'UserDefNativeListUnionKind', 'enum_values': None}]
+ {'enum_name': 'UserDefNativeListUnionKind', 'enum_values': None},
+ {'enum_name': '__org.qemu_x-Union1Kind', 'enum_values': None}]
 [OrderedDict([('struct', 'NestedEnumsOne'), ('data', OrderedDict([('enum1', 'EnumOne'), ('*enum2', 'EnumOne'), ('enum3', 'EnumOne'), ('*enum4', 'EnumOne')]))]),
  OrderedDict([('struct', 'UserDefZero'), ('data', OrderedDict([('integer', 'int')]))]),
  OrderedDict([('struct', 'UserDefOne'), ('base', 'UserDefZero'), ('data', OrderedDict([('string', 'str'), ('*enum1', 'EnumOne')]))]),