[Qemu-devel] [PATCH v8 10/17] qapi: Simplify visiting of alternate types

[Eric Blake]

Previously, working with alternates required two enums, and
some indirection: for type Foo, we created Foo_qtypes[] which
maps each qtype to a member of FooKind_lookup[], then use
FooKind_lookup[] like we do for other union types.

This has a subtle bug: since the values of FooKind_lookup
start at zero, all entries of Foo_qtypes that were not
explicitly initialized map to the same branch of the union as
the first member of the alternate, rather than triggering a
failure in visit_get_next_type().  Fortunately, the bug
seldom bites; the very next thing the input visitor does is
try to parse the incoming JSON with the wrong parser, which
fails; the output visitor is not used with a C struct in that
state, and the dealloc visitor has nothing to clean up (so
there is no leak).

However, it IS observable in one case: the behavior of an
alternate that contains a 'number' member but no 'int' member
differs according to whether the 'number' was first in the
qapi definition, and when the input being parsed is an integer;
this is because the 'number' parser accepts QTYPE_QINT in
addition to the expected QTYPE_QFLOAT.  A later patch will worry
about fixing alternates to parse all inputs that a non-alternate
'number' would accept, for now it is still marked FIXME.

This patch fixes the validation bug by deleting the indirection,
and modifying get_next_type() to directly return a qtype code.
There is no longer a need to generate an implicit FooKind array
associated with the alternate type (since the QMP wire format
never uses the stringized counterparts of the C union member
names); that also means we no longer have a collision with an
alternate branch named 'max'.  Next, the generated visitor is
fixed to properly detect unexpected qtypes in the switch
statement.  This is done via the use of a new
QAPISchemaAlternateTypeTag subclass and the use of a new
member.c_type() method when producing qapi-types.  The new
subtype also allows us to clean up a TODO left in the previous
commit.

Callers now have to know the QTYPE_* mapping when looking at the
discriminator; but so far, only the testsuite was even using the
C struct of an alternate types.  If that gets too confusing, we
could reintroduce FooKind, but initialize it differently than
most generated arrays, as in:
  typedef enum FooKind {
      FOO_KIND_A = QTYPE_QDICT,
      FOO_KIND_B = QTYPE_QINT,
  } FooKind;
to create nicer aliases for knowing when to use foo->a or foo->b
when inspecting foo->type.  But without a current client, I
didn't see the point of doing it now.

There is a user-visible side effect to this change, but I
consider it to be an improvement. Previously,
the invalid QMP command:
  {"execute":"blockdev-add", "arguments":{"options":
    {"driver":"raw", "id":"a", "file":true}}}
failed with:
  {"error": {"class": "GenericError",
    "desc": "Invalid parameter type for 'file', expected: QDict"}}
Now it fails with:
  {"error": {"class": "GenericError",
    "desc": "Invalid parameter type for 'file', expected: BlockdevRef"}}

Signed-off-by: Eric Blake <address@hidden>

---
v8: no change
v7: rebase onto earlier changes, rework how subtype makes things work
v6: rebase onto tag_member subclass, testsuite, gen_err_check(),
and info improvements
---
 docs/qapi-code-gen.txt                  |  3 ---
 include/qapi/visitor-impl.h             |  3 ++-
 include/qapi/visitor.h                  |  8 +++++-
 qapi/qapi-visit-core.c                  |  4 +--
 qapi/qmp-input-visitor.c                |  4 +--
 scripts/qapi-types.py                   | 36 +--------------------------
 scripts/qapi-visit.py                   | 12 +++++----
 scripts/qapi.py                         | 43 ++++++++++++++++++++++-----------
 tests/qapi-schema/alternate-empty.out   |  1 -
 tests/qapi-schema/qapi-schema-test.json |  2 +-
 tests/qapi-schema/qapi-schema-test.out  | 10 +-------
 tests/test-qmp-input-visitor.c          | 33 +++++++++++++------------
 tests/test-qmp-output-visitor.c         | 21 ++++++++++++----
 13 files changed, 86 insertions(+), 94 deletions(-)

diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index 163f547..0c1bd36 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -383,9 +383,6 @@ where each branch of the union names a QAPI type.  For 
example:
    'data': { 'definition': 'BlockdevOptions',
              'reference': 'str' } }

-Just like for a simple union, an implicit C enum 'NameKind' is created
-to enumerate the branches for the alternate 'Name'.
-
 Unlike a union, the discriminator string is never passed on the wire
 for the Client JSON Protocol.  Instead, the value's JSON type serves
 as an implicit discriminator, which in turn means that an alternate
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 8c0ba57..6d95b36 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -32,7 +32,8 @@ struct Visitor

     void (*type_enum)(Visitor *v, int *obj, const char * const strings[],
                       const char *kind, const char *name, Error **errp);
-    void (*get_next_type)(Visitor *v, int *kind, const int *qobjects,
+    /* May be NULL; most useful for input visitors. */
+    void (*get_next_type)(Visitor *v, qtype_code *type,
                           const char *name, Error **errp);

     void (*type_int)(Visitor *v, int64_t *obj, const char *name, Error **errp);
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index cfc19a6..b765993 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -41,7 +41,13 @@ GenericList *visit_next_list(Visitor *v, GenericList **list, 
Error **errp);
 void visit_end_list(Visitor *v, Error **errp);
 void visit_optional(Visitor *v, bool *present, const char *name,
                     Error **errp);
-void visit_get_next_type(Visitor *v, int *obj, const int *qtypes,
+
+/**
+ * Determine the qtype of the item @name in the current object visit.
+ * For input visitors, set address@hidden to the correct qtype of a qapi
+ * alternate type; for other visitors, leave address@hidden unchanged.
+ */
+void visit_get_next_type(Visitor *v, qtype_code *type,
                          const char *name, Error **errp);
 void visit_type_enum(Visitor *v, int *obj, const char * const strings[],
                      const char *kind, const char *name, Error **errp);
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 59ed506..3f24daa 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -81,11 +81,11 @@ void visit_optional(Visitor *v, bool *present, const char 
*name,
     }
 }

-void visit_get_next_type(Visitor *v, int *obj, const int *qtypes,
+void visit_get_next_type(Visitor *v, qtype_code *type,
                          const char *name, Error **errp)
 {
     if (v->get_next_type) {
-        v->get_next_type(v, obj, qtypes, name, errp);
+        v->get_next_type(v, type, name, errp);
     }
 }

diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index 5dd9ed5..803ffad 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -208,7 +208,7 @@ static void qmp_input_end_list(Visitor *v, Error **errp)
     qmp_input_pop(qiv, errp);
 }

-static void qmp_input_get_next_type(Visitor *v, int *kind, const int *qobjects,
+static void qmp_input_get_next_type(Visitor *v, qtype_code *type,
                                     const char *name, Error **errp)
 {
     QmpInputVisitor *qiv = to_qiv(v);
@@ -218,7 +218,7 @@ static void qmp_input_get_next_type(Visitor *v, int *kind, 
const int *qobjects,
         error_setg(errp, QERR_MISSING_PARAMETER, name ? name : "null");
         return;
     }
-    *kind = qobjects[qobject_type(qobj)];
+    *type = qobject_type(qobj);
 }

 static void qmp_input_type_int(Visitor *v, int64_t *obj, const char *name,
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index 403768b..3fd07fd 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -47,7 +47,7 @@ def gen_struct_field(member):
     ret += mcgen('''
     %(c_type)s %(c_name)s;
 ''',
-                 c_type=member.type.c_type(), c_name=c_name(member.name))
+                 c_type=member.c_type(), c_name=c_name(member.name))
     return ret


@@ -111,38 +111,6 @@ static inline %(base)s *qapi_%(c_name)s_base(const 
%(c_name)s *obj)
                  c_name=c_name(name), base=base.c_name())


-def gen_alternate_qtypes_decl(name):
-    return mcgen('''
-
-extern const int %(c_name)s_qtypes[];
-''',
-                 c_name=c_name(name))
-
-
-def gen_alternate_qtypes(name, variants):
-    ret = mcgen('''
-
-const int %(c_name)s_qtypes[QTYPE_MAX] = {
-''',
-                c_name=c_name(name))
-
-    for var in variants.variants:
-        qtype = var.type.alternate_qtype()
-        assert qtype
-
-        ret += mcgen('''
-    [%(qtype)s] = %(enum_const)s,
-''',
-                     qtype=qtype,
-                     enum_const=c_enum_const(variants.tag_member.type.name,
-                                             var.name))
-
-    ret += mcgen('''
-};
-''')
-    return ret
-
-
 def gen_variants(variants):
     # FIXME: What purpose does data serve, besides preventing a union that
     # has a branch named 'data'? We use it in qapi-visit.py to decide
@@ -267,9 +235,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):

     def visit_alternate_type(self, name, info, variants):
         self._fwdecl += gen_fwd_object_or_array(name)
-        self._fwdefn += gen_alternate_qtypes(name, variants)
         self.decl += gen_object(name, None, [variants.tag_member], variants)
-        self.decl += gen_alternate_qtypes_decl(name)
         self._gen_type_cleanup(name)

 # If you link code generated from multiple schemata, you want only one
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 318b8e6..2091a0f 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -189,7 +189,7 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, 
const char *name, Error
     if (err) {
         goto out;
     }
-    visit_get_next_type(v, (int*) &(*obj)->type, %(c_name)s_qtypes, name, 
&err);
+    visit_get_next_type(v, &(*obj)->type, name, &err);
     if (err) {
         goto out_obj;
     }
@@ -203,14 +203,14 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, 
const char *name, Error
         visit_type_%(c_type)s(v, &(*obj)->u.%(c_name)s, name, &err);
         break;
 ''',
-                     case=c_enum_const(variants.tag_member.type.name,
-                                       var.name),
+                     case=var.type.alternate_qtype(),
                      c_type=var.type.c_name(),
                      c_name=c_name(var.name))

     ret += mcgen('''
     default:
-        abort();
+        error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
+                   "%(name)s");
     }
 out_obj:
     error_propagate(errp, err);
@@ -219,7 +219,8 @@ out_obj:
 out:
     error_propagate(errp, err);
 }
-''')
+''',
+                 name=name)

     return ret

@@ -425,6 +426,7 @@ fdef.write(mcgen('''

 fdecl.write(mcgen('''
 #include "qapi/visitor.h"
+#include "qapi/qmp/qerror.h"
 #include "%(prefix)sqapi-types.h"

 ''',
diff --git a/scripts/qapi.py b/scripts/qapi.py
index a0639e4..bd74470 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -627,15 +627,15 @@ def check_union(expr, expr_info):
 def check_alternate(expr, expr_info):
     name = expr['alternate']
     members = expr['data']
-    values = {'MAX': '(automatic)'}
+    values = {}
     types_seen = {}

     # Check every branch
     for (key, value) in members.items():
         check_name(expr_info, "Member of alternate '%s'" % name, key)

-        # Check for conflicts in the generated enum
-        c_key = camel_to_upper(key)
+        # Check for conflicts in the branch names
+        c_key = c_name(key)
         if c_key in values:
             raise QAPIExprError(expr_info,
                                 "Alternate '%s' member '%s' clashes with '%s'"
@@ -1029,13 +1029,17 @@ class QAPISchemaObjectTypeMember(object):
         assert self.type
         seen[self.name] = self

+    def c_type(self):
+        return self.type.c_type()
+

 class QAPISchemaObjectTypeVariants(object):
     def __init__(self, tag_name, tag_member, variants):
         # Flat unions pass tag_name but not tag_member.
         # Simple unions and alternates pass tag_member but not tag_name.
         # After check(), tag_member is always set, and tag_name remains
-        # a reliable witness of being used by a flat union.
+        # a reliable witness of being used by a flat union, and
+        # tag_member.type being None is a reliable witness of an alternate.
         assert bool(tag_member) != bool(tag_name)
         assert (isinstance(tag_name, str) or
                 isinstance(tag_member, QAPISchemaObjectTypeMember))
@@ -1045,8 +1049,7 @@ class QAPISchemaObjectTypeVariants(object):
         self.tag_member = tag_member
         self.variants = variants

-    # TODO drop union once alternates can be distinguished by tag_member
-    def check(self, schema, seen, union=True):
+    def check(self, schema, seen):
         if self.tag_name:    # flat union
             self.tag_member = seen[self.tag_name]
             assert self.tag_member
@@ -1054,25 +1057,25 @@ class QAPISchemaObjectTypeVariants(object):
             assert self.tag_member in seen.itervalues()
         else:                # alternate
             self.tag_member.check(schema, seen)
-        assert isinstance(self.tag_member.type, QAPISchemaEnumType)
+        if not isinstance(self.tag_member, QAPISchemaAlternateTypeTag):
+            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
         cases = OrderedDict()
         for v in self.variants:
             # Reset seen array for each variant, since QMP names from one
             # branch do not affect another branch, nor add to all_members
-            v.check(schema, self.tag_member.type, dict(seen), cases, union)
+            v.check(schema, self.tag_member.type, dict(seen), cases)


 class QAPISchemaObjectTypeVariant(QAPISchemaObjectTypeMember):
     def __init__(self, name, typ):
         QAPISchemaObjectTypeMember.__init__(self, name, typ, False)

-    # TODO drop union once alternates can be distinguished by tag_type
-    def check(self, schema, tag_type, seen, cases, union):
+    def check(self, schema, tag_type, seen, cases):
         # cases is case names we must not collide with
         QAPISchemaObjectTypeMember.check(self, schema, cases)
-        assert self.name in tag_type.values
-        if union:
+        if tag_type:
             # seen is QMP names our members must not collide with
+            assert self.name in tag_type.values
             self.type.check_qmp(schema, seen)

     # This function exists to support ugly simple union special cases
@@ -1094,7 +1097,7 @@ class QAPISchemaAlternateType(QAPISchemaType):
         self.variants = variants

     def check(self, schema):
-        self.variants.check(schema, {}, False)
+        self.variants.check(schema, {})

     def json_type(self):
         return 'value'
@@ -1103,6 +1106,18 @@ class QAPISchemaAlternateType(QAPISchemaType):
         visitor.visit_alternate_type(self.name, self.info, self.variants)


+class QAPISchemaAlternateTypeTag(QAPISchemaObjectTypeMember):
+    def __init__(self):
+        QAPISchemaObjectTypeMember.__init__(self, 'type', '', False)
+
+    def check(self, schema, seen):
+        assert len(seen) == 0
+        seen[self.name] = self
+
+    def c_type(self):
+        return 'qtype_code'
+
+
 class QAPISchemaCommand(QAPISchemaEntity):
     def __init__(self, name, info, arg_type, ret_type, gen, success_response):
         QAPISchemaEntity.__init__(self, name, info)
@@ -1296,7 +1311,7 @@ class QAPISchema(object):
         data = expr['data']
         variants = [self._make_variant(key, value)
                     for (key, value) in data.iteritems()]
-        tag_member = self._make_implicit_tag(name, info, variants)
+        tag_member = QAPISchemaAlternateTypeTag()
         self._def_entity(
             QAPISchemaAlternateType(name, info,
                                     QAPISchemaObjectTypeVariants(None,
diff --git a/tests/qapi-schema/alternate-empty.out 
b/tests/qapi-schema/alternate-empty.out
index 0f153b6..9b010d8 100644
--- a/tests/qapi-schema/alternate-empty.out
+++ b/tests/qapi-schema/alternate-empty.out
@@ -1,4 +1,3 @@
 object :empty
 alternate Alt
     case i: int
-enum AltKind ['i']
diff --git a/tests/qapi-schema/qapi-schema-test.json 
b/tests/qapi-schema/qapi-schema-test.json
index 4354604..4513d94 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -131,7 +131,7 @@
   'data': { 'value1': 'UserDefZero', 'has_a': 'UserDefZero',
             'u': 'UserDefZero', 'type': 'UserDefZero' } }
 { 'alternate': 'AltName', 'data': { 'type': 'int', 'u': 'bool',
-                                    'myKind': 'has_a' } }
+                                    'myKind': 'has_a', 'max': 'str' } }

 # testing commands
 { 'command': 'user_def_cmd', 'data': {} }
diff --git a/tests/qapi-schema/qapi-schema-test.out 
b/tests/qapi-schema/qapi-schema-test.out
index 29c46da..eda71b9 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -60,32 +60,26 @@ object :obj-user_def_cmd2-arg
 alternate AltIntNum
     case i: int
     case n: number
-enum AltIntNumKind ['i', 'n']
 alternate AltName
     case type: int
     case u: bool
     case myKind: has_a
-enum AltNameKind ['type', 'u', 'myKind']
+    case max: str
 alternate AltNumInt
     case n: number
     case i: int
-enum AltNumIntKind ['n', 'i']
 alternate AltNumStr
     case n: number
     case s: str
-enum AltNumStrKind ['n', 's']
 alternate AltStrBool
     case s: str
     case b: bool
-enum AltStrBoolKind ['s', 'b']
 alternate AltStrInt
     case s: str
     case i: int
-enum AltStrIntKind ['s', 'i']
 alternate AltStrNum
     case s: str
     case n: number
-enum AltStrNumKind ['s', 'n']
 event EVENT_A None
 event EVENT_B None
 event EVENT_C :obj-EVENT_C-arg
@@ -129,7 +123,6 @@ alternate UserDefAlternate
     case uda: UserDefA
     case s: str
     case i: int
-enum UserDefAlternateKind ['uda', 's', 'i']
 object UserDefB
     member intb: int optional=False
     member a-b: bool optional=True
@@ -198,7 +191,6 @@ event __ORG.QEMU_X-EVENT __org.qemu_x-Struct
 alternate __org.qemu_x-Alt
     case __org.qemu_x-branch: str
     case b: __org.qemu_x-Base
-enum __org.qemu_x-AltKind ['__org.qemu_x-branch', 'b']
 object __org.qemu_x-Base
     member __org.qemu_x-member1: __org.qemu_x-Enum optional=False
 enum __org.qemu_x-Enum ['__org.qemu_x-value']
diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c
index 3f6bc4d..552fc74 100644
--- a/tests/test-qmp-input-visitor.c
+++ b/tests/test-qmp-input-visitor.c
@@ -343,14 +343,14 @@ static void 
test_visitor_in_alternate(TestInputVisitorData *data,

     v = visitor_input_test_init(data, "42");
     visit_type_UserDefAlternate(v, &tmp, NULL, &error_abort);
-    g_assert_cmpint(tmp->type, ==, USER_DEF_ALTERNATE_KIND_I);
+    g_assert_cmpint(tmp->type, ==, QTYPE_QINT);
     g_assert_cmpint(tmp->u.i, ==, 42);
     qapi_free_UserDefAlternate(tmp);
     visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "'string'");
     visit_type_UserDefAlternate(v, &tmp, NULL, &error_abort);
-    g_assert_cmpint(tmp->type, ==, USER_DEF_ALTERNATE_KIND_S);
+    g_assert_cmpint(tmp->type, ==, QTYPE_QSTRING);
     g_assert_cmpstr(tmp->u.s, ==, "string");
     qapi_free_UserDefAlternate(tmp);
     visitor_input_teardown(data, NULL);
@@ -386,11 +386,10 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,
     qapi_free_AltStrBool(asb);
     visitor_input_teardown(data, NULL);

-    /* FIXME: Order of alternate should not affect semantics; asn should
-     * parse the same as ans */
+    /* FIXME: integer should parse as number */
     v = visitor_input_test_init(data, "42");
     visit_type_AltStrNum(v, &asn, NULL, &err);
-    /* FIXME g_assert_cmpint(asn->type, == ALT_STR_NUM_KIND_N); */
+    /* FIXME g_assert_cmpint(asn->type, ==, QTYPE_QFLOAT); */
     /* FIXME g_assert_cmpfloat(asn->u.n, ==, 42); */
     g_assert(err);
     error_free(err);
@@ -398,30 +397,34 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,
     qapi_free_AltStrNum(asn);
     visitor_input_teardown(data, NULL);

+    /* FIXME: integer should parse as number */
     v = visitor_input_test_init(data, "42");
-    visit_type_AltNumStr(v, &ans, NULL, &error_abort);
-    g_assert_cmpint(ans->type, ==, ALT_NUM_STR_KIND_N);
-    g_assert_cmpfloat(ans->u.n, ==, 42);
+    visit_type_AltNumStr(v, &ans, NULL, &err);
+    /* FIXME g_assert_cmpint(ans->type, ==, QTYPE_QFLOAT); */
+    /* FIXME g_assert_cmpfloat(ans->u.n, ==, 42); */
+    g_assert(err);
+    error_free(err);
+    err = NULL;
     qapi_free_AltNumStr(ans);
     visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltStrInt(v, &asi, NULL, &error_abort);
-    g_assert_cmpint(asi->type, ==, ALT_STR_INT_KIND_I);
+    g_assert_cmpint(asi->type, ==, QTYPE_QINT);
     g_assert_cmpint(asi->u.i, ==, 42);
     qapi_free_AltStrInt(asi);
     visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltIntNum(v, &ain, NULL, &error_abort);
-    g_assert_cmpint(ain->type, ==, ALT_INT_NUM_KIND_I);
+    g_assert_cmpint(ain->type, ==, QTYPE_QINT);
     g_assert_cmpint(ain->u.i, ==, 42);
     qapi_free_AltIntNum(ain);
     visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltNumInt(v, &ani, NULL, &error_abort);
-    g_assert_cmpint(ani->type, ==, ALT_NUM_INT_KIND_I);
+    g_assert_cmpint(ani->type, ==, QTYPE_QINT);
     g_assert_cmpint(ani->u.i, ==, 42);
     qapi_free_AltNumInt(ani);
     visitor_input_teardown(data, NULL);
@@ -438,14 +441,14 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltStrNum(v, &asn, NULL, &error_abort);
-    g_assert_cmpint(asn->type, ==, ALT_STR_NUM_KIND_N);
+    g_assert_cmpint(asn->type, ==, QTYPE_QFLOAT);
     g_assert_cmpfloat(asn->u.n, ==, 42.5);
     qapi_free_AltStrNum(asn);
     visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltNumStr(v, &ans, NULL, &error_abort);
-    g_assert_cmpint(ans->type, ==, ALT_NUM_STR_KIND_N);
+    g_assert_cmpint(ans->type, ==, QTYPE_QFLOAT);
     g_assert_cmpfloat(ans->u.n, ==, 42.5);
     qapi_free_AltNumStr(ans);
     visitor_input_teardown(data, NULL);
@@ -460,14 +463,14 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltIntNum(v, &ain, NULL, &error_abort);
-    g_assert_cmpint(ain->type, ==, ALT_INT_NUM_KIND_N);
+    g_assert_cmpint(ain->type, ==, QTYPE_QFLOAT);
     g_assert_cmpfloat(ain->u.n, ==, 42.5);
     qapi_free_AltIntNum(ain);
     visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltNumInt(v, &ani, NULL, &error_abort);
-    g_assert_cmpint(ani->type, ==, ALT_NUM_INT_KIND_N);
+    g_assert_cmpint(ani->type, ==, QTYPE_QFLOAT);
     g_assert_cmpfloat(ani->u.n, ==, 42.5);
     qapi_free_AltNumInt(ani);
     visitor_input_teardown(data, NULL);
diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c
index 9364843..695db32 100644
--- a/tests/test-qmp-output-visitor.c
+++ b/tests/test-qmp-output-visitor.c
@@ -449,20 +449,31 @@ static void 
test_visitor_out_alternate(TestOutputVisitorData *data,
                                        const void *unused)
 {
     QObject *arg;
-    Error *err = NULL;
+    UserDefAlternate *tmp;

-    UserDefAlternate *tmp = g_malloc0(sizeof(UserDefAlternate));
-    tmp->type = USER_DEF_ALTERNATE_KIND_I;
+    tmp = g_new0(UserDefAlternate, 1);
+    tmp->type = QTYPE_QINT;
     tmp->u.i = 42;

-    visit_type_UserDefAlternate(data->ov, &tmp, NULL, &err);
-    g_assert(err == NULL);
+    visit_type_UserDefAlternate(data->ov, &tmp, NULL, &error_abort);
     arg = qmp_output_get_qobject(data->qov);

     g_assert(qobject_type(arg) == QTYPE_QINT);
     g_assert_cmpint(qint_get_int(qobject_to_qint(arg)), ==, 42);

     qapi_free_UserDefAlternate(tmp);
+
+    tmp = g_malloc0(sizeof(UserDefAlternate));
+    tmp->type = QTYPE_QSTRING;
+    tmp->u.s = g_strdup("hello");
+
+    visit_type_UserDefAlternate(data->ov, &tmp, NULL, &error_abort);
+    arg = qmp_output_get_qobject(data->qov);
+
+    g_assert(qobject_type(arg) == QTYPE_QSTRING);
+    g_assert_cmpstr(qstring_get_str(qobject_to_qstring(arg)), ==, "hello");
+
+    qapi_free_UserDefAlternate(tmp);
 }

 static void test_visitor_out_empty(TestOutputVisitorData *data,
-- 
2.4.3