qapi: Use generated TestStruct machinery in tests

Commit d88f5fd and friends first introduced the various test-qmp-*
tests in 2011, with duplicated hand-rolled TestStruct machinery,
to make sure the qapi visitor interface was tested.  Later, commit
4f193e3 in 2013 added a .json file for further testing use by the
files, but without consolidating any of the existing hand-rolled
visitors.  And with four copies, subtle differences have crept in,
between the tests themselves (mainly whitespace differences, but
also a question of whether to use NULL or "TestStruct" when
calling visit_start_struct()) and from what the generator produces
(the hand-rolled versions did not cater to partially-allocated
objects, because they did not have a deallocation usage).

Of course, just because the visitor interface is tested does not
mean it is a sane interface; and future patches will be changing
some of the visitor contracts.  Rather than having to duplicate
the cleanup work in each copy of the TestStruct visitor, and keep
each hand-rolled copy in sync with what the generator supplies, we
might as well just test what the generator should give us in the
first place.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1446791754-23823-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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

@@ -3,6 +3,9 @@
 # This file is a stress test of supported qapi constructs that must
 # parse and compile correctly.
 
+{ 'struct': 'TestStruct',
+  'data': { 'integer': 'int', 'boolean': 'bool', 'string': 'str' } }
+
 # for testing enums
 { 'struct': 'NestedEnumsOne',
   'data': { 'enum1': 'EnumOne',   # Intentional forward reference
@@ -46,7 +49,8 @@
 
 # dummy struct to force generation of array types not otherwise mentioned
 { 'struct': 'ForceArrays',
-  'data': { 'unused1':['UserDefOne'], 'unused2':['UserDefTwo'] } }
+  'data': { 'unused1':['UserDefOne'], 'unused2':['UserDefTwo'],
+            'unused3':['TestStruct'] } }
 
 # for testing unions
 # Among other things, test that a name collision between branches does

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

@@ -92,6 +92,7 @@ object EventStructOne
 object ForceArrays
     member unused1: UserDefOneList optional=False
     member unused2: UserDefTwoList optional=False
+    member unused3: TestStructList optional=False
 enum MyEnum []
 object NestedEnumsOne
     member enum1: EnumOne optional=False
@@ -100,6 +101,10 @@ object NestedEnumsOne
     member enum4: EnumOne optional=True
 enum QEnumTwo ['value1', 'value2']
     prefix QENUM_TWO
+object TestStruct
+    member integer: int optional=False
+    member boolean: bool optional=False
+    member string: str optional=False
 object UserDefA
     member boolean: bool optional=False
     member a_b: int optional=True