qapi: Support downstream flat unions

Enhance the testsuite to cover downstream flat unions, including
the base type, discriminator name and type, and branch name and
type.  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

@@ -213,7 +213,7 @@ struct %(name)s
         void *data;
 ''',
                 name=name,
-                discriminator_type_name=discriminator_type_name)
+                discriminator_type_name=c_name(discriminator_type_name))
 
     for key in typeinfo:
         ret += mcgen('''

scripts/qapi-visit.py

@@ -252,7 +252,7 @@ def generate_visit_union(expr):
     if enum_define:
         # Use the enum type as discriminator
         ret = ""
-        disc_type = enum_define['enum_name']
+        disc_type = c_name(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
@@ -290,7 +290,7 @@ void visit_type_%(name)s(Visitor *m, %(name)s **obj, const char *name, Error **e
             goto out_obj;
         }
 ''',
-            name=name)
+                     name=c_name(name))
 
     if not discriminator:
         disc_key = "type"

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

@@ -115,3 +115,8 @@
 { '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' } }
+{ 'struct': '__org.qemu_x-Struct2',
+  'data': { 'array': ['__org.qemu_x-Union1'] } }
+{ 'union': '__org.qemu_x-Union2', 'base': '__org.qemu_x-Base',
+  'discriminator': '__org.qemu_x-member1',
+  'data': { '__org.qemu_x-value': '__org.qemu_x-Struct2' } }

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

@@ -26,7 +26,9 @@
  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([('union', '__org.qemu_x-Union1'), ('data', OrderedDict([('__org.qemu_x-branch', 'str')]))])]
+ OrderedDict([('union', '__org.qemu_x-Union1'), ('data', OrderedDict([('__org.qemu_x-branch', 'str')]))]),
+ OrderedDict([('struct', '__org.qemu_x-Struct2'), ('data', OrderedDict([('array', ['__org.qemu_x-Union1'])]))]),
+ OrderedDict([('union', '__org.qemu_x-Union2'), ('base', '__org.qemu_x-Base'), ('discriminator', '__org.qemu_x-member1'), ('data', OrderedDict([('__org.qemu_x-value', '__org.qemu_x-Struct2')]))])]
 [{'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},
@@ -45,4 +47,5 @@
  OrderedDict([('struct', 'UserDefOptions'), ('data', OrderedDict([('*i64', ['int']), ('*u64', ['uint64']), ('*u16', ['uint16']), ('*i64x', 'int'), ('*u64x', 'uint64')]))]),
  OrderedDict([('struct', 'EventStructOne'), ('data', OrderedDict([('struct1', 'UserDefOne'), ('string', 'str'), ('*enum2', 'EnumOne')]))]),
  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([('struct', '__org.qemu_x-Struct2'), ('data', OrderedDict([('array', ['__org.qemu_x-Union1'])]))])]