diff mbox

[v6,16/36] qapi: Use 'alternate' to replace anonymous union

Message ID 1428206887-7921-17-git-send-email-eblake@redhat.com
State New
Headers show

Commit Message

Eric Blake April 5, 2015, 4:07 a.m. UTC
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>

---

v6: split out doc patches, rebase onto fixes earlier in series,
hoist several unrelated minor bug fixes earlier into series,
fix some more instances of 'anonymous union'.
---
 qapi/block-core.json                               |  6 ++--
 scripts/qapi-types.py                              | 26 ++++++++++++------
 scripts/qapi-visit.py                              | 17 ++++++++----
 scripts/qapi.py                                    | 32 ++++++++++------------
 tests/qapi-schema/alternate-array.err              |  2 +-
 tests/qapi-schema/alternate-array.json             |  5 ++--
 tests/qapi-schema/alternate-base.err               |  2 +-
 tests/qapi-schema/alternate-base.json              |  5 ++--
 tests/qapi-schema/alternate-clash.err              |  2 +-
 tests/qapi-schema/alternate-clash.json             |  5 ++--
 tests/qapi-schema/alternate-conflict-dict.err      |  2 +-
 tests/qapi-schema/alternate-conflict-dict.json     |  5 ++--
 tests/qapi-schema/alternate-conflict-string.err    |  2 +-
 tests/qapi-schema/alternate-conflict-string.json   |  5 ++--
 tests/qapi-schema/alternate-good.json              |  5 ++--
 tests/qapi-schema/alternate-good.out               |  4 +--
 tests/qapi-schema/alternate-nested.err             |  2 +-
 tests/qapi-schema/alternate-nested.json            | 10 +++----
 tests/qapi-schema/alternate-unknown.err            |  2 +-
 tests/qapi-schema/alternate-unknown.json           |  5 ++--
 tests/qapi-schema/flat-union-bad-discriminator.err |  2 +-
 .../qapi-schema/flat-union-bad-discriminator.json  |  3 +-
 tests/qapi-schema/flat-union-base-union.json       |  2 +-
 tests/qapi-schema/qapi-schema-test.json            |  3 +-
 tests/qapi-schema/qapi-schema-test.out             |  2 +-
 25 files changed, 78 insertions(+), 78 deletions(-)

Comments

Markus Armbruster April 28, 2015, 8:41 a.m. UTC | #1
Eric Blake <eblake@redhat.com> writes:

> 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>
[...]
> diff --git a/tests/qapi-schema/flat-union-base-union.json b/tests/qapi-schema/flat-union-base-union.json
> index 838986c..0ba6e28 100644
> --- a/tests/qapi-schema/flat-union-base-union.json
> +++ b/tests/qapi-schema/flat-union-base-union.json
> @@ -1,4 +1,4 @@
> -# FIXME: the error message needs help: we require the base to be a struct
> +# we require the base to be a struct
>  { 'enum': 'TestEnum',
>    'data': [ 'value1', 'value2' ] }
>  { 'type': 'TestTypeA',

This looks unrelated.  Does it belong to PATCH 25?

[...]

Regardless,
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Eric Blake April 28, 2015, 5:29 p.m. UTC | #2
On 04/28/2015 02:41 AM, Markus Armbruster wrote:
> Eric Blake <eblake@redhat.com> writes:
> 
>> 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>
> [...]
>> diff --git a/tests/qapi-schema/flat-union-base-union.json b/tests/qapi-schema/flat-union-base-union.json
>> index 838986c..0ba6e28 100644
>> --- a/tests/qapi-schema/flat-union-base-union.json
>> +++ b/tests/qapi-schema/flat-union-base-union.json
>> @@ -1,4 +1,4 @@
>> -# FIXME: the error message needs help: we require the base to be a struct
>> +# we require the base to be a struct
>>  { 'enum': 'TestEnum',
>>    'data': [ 'value1', 'value2' ] }
>>  { 'type': 'TestTypeA',
> 
> This looks unrelated.  Does it belong to PATCH 25?

Uggh - more evidence of botched hunk motion across rebase.

> 
> [...]
> 
> Regardless,
> Reviewed-by: Markus Armbruster <armbru@redhat.com>

End result is the same, so unless I need to rebase on top of all the
other patches going in right now, I won't bother to respin.
diff mbox

Patch

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 7873084..a76be74 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1419,8 +1419,7 @@ 
 #
 # Since: 2.2
 ##
-{ 'union': 'Qcow2OverlapChecks',
-  'discriminator': {},
+{ 'alternate': 'Qcow2OverlapChecks',
   'data': { 'flags': 'Qcow2OverlapCheckFlags',
             'mode':  'Qcow2OverlapCheckMode' } }

@@ -1711,8 +1710,7 @@ 
 #
 # Since: 1.7
 ##
-{ 'union': 'BlockdevRef',
-  'discriminator': {},
+{ 'alternate': 'BlockdevRef',
   'data': { 'definition': 'BlockdevOptions',
             'reference': 'str' } }

diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index c9e0201..9c8d68c 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -172,7 +172,7 @@  typedef enum %(name)s

 def generate_alternate_qtypes(expr):

-    name = expr['union']
+    name = expr['alternate']
     members = expr['data']

     ret = mcgen('''
@@ -182,7 +182,7 @@  const int %(name)s_qtypes[QTYPE_MAX] = {

     for key in members:
         qtype = find_alternate_member_qtype(members[key])
-        assert qtype, "Invalid anonymous union member"
+        assert qtype, "Invalid alternate member"

         ret += mcgen('''
     [ %(qtype)s ] = %(abbrev)s_KIND_%(enum)s,
@@ -197,9 +197,9 @@  const int %(name)s_qtypes[QTYPE_MAX] = {
     return ret


-def generate_union(expr):
+def generate_union(expr, meta):

-    name = expr['union']
+    name = expr[meta]
     typeinfo = expr['data']

     base = expr.get('base')
@@ -243,7 +243,7 @@  struct %(name)s
     ret += mcgen('''
 };
 ''')
-    if discriminator == {}:
+    if meta == 'alternate':
         ret += mcgen('''
 extern const int %(name)s_qtypes[];
 ''',
@@ -407,8 +407,12 @@  for expr in exprs:
             ret += generate_enum('%sKind' % expr['union'], expr['data'].keys())
             fdef.write(generate_enum_lookup('%sKind' % expr['union'],
                                             expr['data'].keys()))
-        if expr.get('discriminator') == {}:
-            fdef.write(generate_alternate_qtypes(expr))
+    elif expr.has_key('alternate'):
+        ret += generate_fwd_struct(expr['alternate'], expr['data']) + "\n"
+        ret += generate_enum('%sKind' % expr['alternate'], expr['data'].keys())
+        fdef.write(generate_enum_lookup('%sKind' % expr['alternate'],
+                                        expr['data'].keys()))
+        fdef.write(generate_alternate_qtypes(expr))
     else:
         continue
     fdecl.write(ret)
@@ -438,11 +442,17 @@  for expr in exprs:
         ret += generate_type_cleanup_decl(expr['type'])
         fdef.write(generate_type_cleanup(expr['type']) + "\n")
     elif expr.has_key('union'):
-        ret += generate_union(expr)
+        ret += generate_union(expr, 'union')
         ret += generate_type_cleanup_decl(expr['union'] + "List")
         fdef.write(generate_type_cleanup(expr['union'] + "List") + "\n")
         ret += generate_type_cleanup_decl(expr['union'])
         fdef.write(generate_type_cleanup(expr['union']) + "\n")
+    elif expr.has_key('alternate'):
+        ret += generate_union(expr, 'alternate')
+        ret += generate_type_cleanup_decl(expr['alternate'] + "List")
+        fdef.write(generate_type_cleanup(expr['alternate'] + "List") + "\n")
+        ret += generate_type_cleanup_decl(expr['alternate'])
+        fdef.write(generate_type_cleanup(expr['alternate']) + "\n")
     elif expr.has_key('enum'):
         ret += generate_type_cleanup_decl(expr['enum'] + "List")
         fdef.write(generate_type_cleanup(expr['enum'] + "List") + "\n")
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 77b0a1f..3e11089 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
@@ -572,6 +568,15 @@  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'])
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 0b88325..05c38c5 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -281,7 +281,6 @@  def check_union(expr, expr_info):
                                 "along with base" %name)

     # Two types of unions, determined by discriminator.
-    assert discriminator != {}

     # With no discriminator it is a simple union.
     if discriminator is None:
@@ -344,17 +343,14 @@  def check_union(expr, expr_info):
             values[c_key] = key

 def check_alternate(expr, expr_info):
-    name = expr['union']
-    base = expr.get('base')
-    discriminator = expr.get('discriminator')
+    name = expr['alternate']
     members = expr['data']
     values = { 'MAX': '(automatic)' }
     types_seen = {}

-    assert discriminator == {}
-    if base is not None:
+    if expr.get('base') is not None:
         raise QAPIExprError(expr_info,
-                            "Anonymous union '%s' must not have a base"
+                            "Alternate '%s' must not have a base"
                             % name)

     # Check every branch
@@ -363,23 +359,23 @@  def check_alternate(expr, expr_info):
         c_key = _generate_enum_string(key)
         if c_key in values:
             raise QAPIExprError(expr_info,
-                                "Anonymous union '%s' member '%s' clashes "
-                                "with '%s'" % (name, key, values[c_key]))
+                                "Alternate '%s' member '%s' clashes with '%s'"
+                                % (name, key, values[c_key]))
         values[c_key] = key

         # Ensure alternates have no type conflicts.
         if isinstance(value, list):
             raise QAPIExprError(expr_info,
-                                "Anonymous union '%s' member '%s' must "
+                                "Alternate '%s' member '%s' must "
                                 "not be array type" % (name, key))
         qtype = find_alternate_member_qtype(value)
         if not qtype:
             raise QAPIExprError(expr_info,
-                                "Anonymous union '%s' member '%s' has "
+                                "Alternate '%s' member '%s' has "
                                 "invalid type '%s'" % (name, key, value))
         if qtype in types_seen:
             raise QAPIExprError(expr_info,
-                                "Anonymous union '%s' member '%s' can't "
+                                "Alternate '%s' member '%s' can't "
                                 "be distinguished from member '%s'"
                                 % (name, key, types_seen[qtype]))
         types_seen[qtype] = key
@@ -412,10 +408,9 @@  def check_exprs(schema):
         if expr.has_key('enum'):
             check_enum(expr, info)
         elif expr.has_key('union'):
-            if expr.get('discriminator') == {}:
-                check_alternate(expr, info)
-            else:
-                check_union(expr, info)
+            check_union(expr, info)
+        elif expr.has_key('alternate'):
+            check_alternate(expr, info)
         elif expr.has_key('event'):
             check_event(expr, info)

@@ -447,6 +442,8 @@  def parse_schema(input_file):
             if expr.has_key('union'):
                 if not discriminator_find_enum_define(expr):
                     add_enum('%sKind' % expr['union'])
+            elif expr.has_key('alternate'):
+                add_enum('%sKind' % expr['alternate'])

         # Final pass - validate that exprs make sense
         check_exprs(schema)
@@ -557,8 +554,7 @@  def find_struct(name):

 def add_union(definition):
     global union_types
-    if definition.get('discriminator') != {}:
-        union_types.append(definition)
+    union_types.append(definition)

 def find_union(name):
     global union_types
diff --git a/tests/qapi-schema/alternate-array.err b/tests/qapi-schema/alternate-array.err
index 8d6ccc7..e2a5fc2 100644
--- a/tests/qapi-schema/alternate-array.err
+++ b/tests/qapi-schema/alternate-array.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-array.json:5: Anonymous union 'MyUnion' member 'two' must not be array type
+tests/qapi-schema/alternate-array.json:5: Alternate 'Alt' member 'two' must not be array type
diff --git a/tests/qapi-schema/alternate-array.json b/tests/qapi-schema/alternate-array.json
index 77970d9..043c0fb 100644
--- a/tests/qapi-schema/alternate-array.json
+++ b/tests/qapi-schema/alternate-array.json
@@ -1,8 +1,7 @@ 
-# we do not support array branches of anonymous unions yet
+# we do not support array branches of alternates yet
 # TODO: should we support this?
 { 'type': 'One',
   'data': { 'name': 'str' } }
-{ 'union': 'MyUnion',
-  'discriminator': {},
+{ 'alternate': 'Alt',
   'data': { 'one': 'One',
             'two': [ 'int' ] } }
diff --git a/tests/qapi-schema/alternate-base.err b/tests/qapi-schema/alternate-base.err
index a2486b8..4a2566e 100644
--- a/tests/qapi-schema/alternate-base.err
+++ b/tests/qapi-schema/alternate-base.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-base.json:4: Anonymous union 'MyUnion' must not have a base
+tests/qapi-schema/alternate-base.json:4: Alternate 'Alt' must not have a base
diff --git a/tests/qapi-schema/alternate-base.json b/tests/qapi-schema/alternate-base.json
index dad7f02..66edc89 100644
--- a/tests/qapi-schema/alternate-base.json
+++ b/tests/qapi-schema/alternate-base.json
@@ -1,7 +1,6 @@ 
-# we reject anonymous union with base type
+# we reject alternate with base type
 { 'type': 'Base',
   'data': { 'string': 'str' } }
-{ 'union': 'MyUnion',
+{ 'alternate': 'Alt',
   'base': 'Base',
-  'discriminator': {},
   'data': { 'number': 'int' } }
diff --git a/tests/qapi-schema/alternate-clash.err b/tests/qapi-schema/alternate-clash.err
index 8949f52..51bea3e 100644
--- a/tests/qapi-schema/alternate-clash.err
+++ b/tests/qapi-schema/alternate-clash.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-clash.json:2: Anonymous union 'Union1' member 'ONE' clashes with 'one'
+tests/qapi-schema/alternate-clash.json:2: Alternate 'Alt1' member 'ONE' clashes with 'one'
diff --git a/tests/qapi-schema/alternate-clash.json b/tests/qapi-schema/alternate-clash.json
index fa2d27e..3947935 100644
--- a/tests/qapi-schema/alternate-clash.json
+++ b/tests/qapi-schema/alternate-clash.json
@@ -1,4 +1,3 @@ 
-# we detect C enum collisions in an anonymous union
-{ 'union': 'Union1',
-  'discriminator': {},
+# we detect C enum collisions in an alternate
+{ 'alternate': 'Alt1',
   'data': { 'one': 'str', 'ONE': 'int' } }
diff --git a/tests/qapi-schema/alternate-conflict-dict.err b/tests/qapi-schema/alternate-conflict-dict.err
index 2d4550c..0f411f4 100644
--- a/tests/qapi-schema/alternate-conflict-dict.err
+++ b/tests/qapi-schema/alternate-conflict-dict.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-conflict-dict.json:6: Anonymous union 'MyUnion' member 'two' can't be distinguished from member 'one'
+tests/qapi-schema/alternate-conflict-dict.json:6: Alternate 'Alt' member 'two' can't be distinguished from member 'one'
diff --git a/tests/qapi-schema/alternate-conflict-dict.json b/tests/qapi-schema/alternate-conflict-dict.json
index ded302e..fcb3e36 100644
--- a/tests/qapi-schema/alternate-conflict-dict.json
+++ b/tests/qapi-schema/alternate-conflict-dict.json
@@ -1,9 +1,8 @@ 
-# we reject anonymous unions with multiple object branches
+# we reject alternates with multiple object branches
 { 'type': 'One',
   'data': { 'name': 'str' } }
 { 'type': 'Two',
   'data': { 'value': 'int' } }
-{ 'union': 'MyUnion',
-  'discriminator': {},
+{ 'alternate': 'Alt',
   'data': { 'one': 'One',
             'two': 'Two' } }
diff --git a/tests/qapi-schema/alternate-conflict-string.err b/tests/qapi-schema/alternate-conflict-string.err
index 271ddcd..fc523b0 100644
--- a/tests/qapi-schema/alternate-conflict-string.err
+++ b/tests/qapi-schema/alternate-conflict-string.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-conflict-string.json:4: Anonymous union 'MyUnion' member 'two' can't be distinguished from member 'one'
+tests/qapi-schema/alternate-conflict-string.json:4: Alternate 'Alt' member 'two' can't be distinguished from member 'one'
diff --git a/tests/qapi-schema/alternate-conflict-string.json b/tests/qapi-schema/alternate-conflict-string.json
index 3834a3d..72f04a8 100644
--- a/tests/qapi-schema/alternate-conflict-string.json
+++ b/tests/qapi-schema/alternate-conflict-string.json
@@ -1,7 +1,6 @@ 
-# we reject anonymous unions with multiple string-like branches
+# we reject alternates with multiple string-like branches
 { 'enum': 'Enum',
   'data': [ 'hello', 'world' ] }
-{ 'union': 'MyUnion',
-  'discriminator': {},
+{ 'alternate': 'Alt',
   'data': { 'one': 'str',
             'two': 'Enum' } }
diff --git a/tests/qapi-schema/alternate-good.json b/tests/qapi-schema/alternate-good.json
index 73d0993..99d614f 100644
--- a/tests/qapi-schema/alternate-good.json
+++ b/tests/qapi-schema/alternate-good.json
@@ -1,10 +1,9 @@ 
-# Working example of anonymous union
+# Working example of alternate
 { 'type': 'Data',
   'data': { '*number': 'int', '*name': 'str' } }
 { 'enum': 'Enum',
   'data': [ 'hello', 'world' ] }
-{ 'union': 'MyUnion',
-  'discriminator': {},
+{ 'alternate': 'Alt',
   'data': { 'value': 'int',
             'string': 'Enum',
             'struct': 'Data' } }
diff --git a/tests/qapi-schema/alternate-good.out b/tests/qapi-schema/alternate-good.out
index b5117d1..c3a6b77 100644
--- a/tests/qapi-schema/alternate-good.out
+++ b/tests/qapi-schema/alternate-good.out
@@ -1,6 +1,6 @@ 
 [OrderedDict([('type', 'Data'), ('data', OrderedDict([('*number', 'int'), ('*name', 'str')]))]),
  OrderedDict([('enum', 'Enum'), ('data', ['hello', 'world'])]),
- OrderedDict([('union', 'MyUnion'), ('discriminator', OrderedDict()), ('data', OrderedDict([('value', 'int'), ('string', 'Enum'), ('struct', 'Data')]))])]
+ OrderedDict([('alternate', 'Alt'), ('data', OrderedDict([('value', 'int'), ('string', 'Enum'), ('struct', 'Data')]))])]
 [{'enum_name': 'Enum', 'enum_values': ['hello', 'world']},
- {'enum_name': 'MyUnionKind', 'enum_values': None}]
+ {'enum_name': 'AltKind', 'enum_values': None}]
 [OrderedDict([('type', 'Data'), ('data', OrderedDict([('*number', 'int'), ('*name', 'str')]))])]
diff --git a/tests/qapi-schema/alternate-nested.err b/tests/qapi-schema/alternate-nested.err
index 59df96e..00b05c6 100644
--- a/tests/qapi-schema/alternate-nested.err
+++ b/tests/qapi-schema/alternate-nested.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-nested.json:5: Anonymous union 'Union2' member 'nested' has invalid type 'Union1'
+tests/qapi-schema/alternate-nested.json:4: Alternate 'Alt2' member 'nested' has invalid type 'Alt1'
diff --git a/tests/qapi-schema/alternate-nested.json b/tests/qapi-schema/alternate-nested.json
index ed2b6b7..c4233b9 100644
--- a/tests/qapi-schema/alternate-nested.json
+++ b/tests/qapi-schema/alternate-nested.json
@@ -1,7 +1,5 @@ 
-# we reject a nested anonymous union branch
-{ 'union': 'Union1',
-  'discriminator': {},
+# we reject a nested alternate branch
+{ 'alternate': 'Alt1',
   'data': { 'name': 'str', 'value': 'int' } }
-{ 'union': 'Union2',
-  'discriminator': {},
-  'data': { 'nested': 'Union1' } }
+{ 'alternate': 'Alt2',
+  'data': { 'nested': 'Alt1' } }
diff --git a/tests/qapi-schema/alternate-unknown.err b/tests/qapi-schema/alternate-unknown.err
index bf8e9ae..7af1b4c 100644
--- a/tests/qapi-schema/alternate-unknown.err
+++ b/tests/qapi-schema/alternate-unknown.err
@@ -1 +1 @@ 
-tests/qapi-schema/alternate-unknown.json:2: Anonymous union 'Union' member 'unknown' has invalid type 'MissingType'
+tests/qapi-schema/alternate-unknown.json:2: Alternate 'Alt' member 'unknown' has invalid type 'MissingType'
diff --git a/tests/qapi-schema/alternate-unknown.json b/tests/qapi-schema/alternate-unknown.json
index 0c305c2..ad5c103 100644
--- a/tests/qapi-schema/alternate-unknown.json
+++ b/tests/qapi-schema/alternate-unknown.json
@@ -1,4 +1,3 @@ 
-# we reject an anonymous union with unknown type in branch
-{ 'union': 'Union',
-  'discriminator': {},
+# we reject an alternate with unknown type in branch
+{ 'alternate': 'Alt',
   'data': { 'unknown': 'MissingType' } }
diff --git a/tests/qapi-schema/flat-union-bad-discriminator.err b/tests/qapi-schema/flat-union-bad-discriminator.err
index 1661c52..507e2ba 100644
--- a/tests/qapi-schema/flat-union-bad-discriminator.err
+++ b/tests/qapi-schema/flat-union-bad-discriminator.err
@@ -1 +1 @@ 
-tests/qapi-schema/flat-union-bad-discriminator.json:10: Flat union 'TestUnion' discriminator must be a string
+tests/qapi-schema/flat-union-bad-discriminator.json:11: Flat union 'TestUnion' discriminator must be a string
diff --git a/tests/qapi-schema/flat-union-bad-discriminator.json b/tests/qapi-schema/flat-union-bad-discriminator.json
index 3ce43e8..982f072 100644
--- a/tests/qapi-schema/flat-union-bad-discriminator.json
+++ b/tests/qapi-schema/flat-union-bad-discriminator.json
@@ -1,4 +1,5 @@ 
 # we require the discriminator to be a string naming a base-type member
+# this tests the old syntax for anonymous unions before we added alternates
 { 'enum': 'TestEnum',
   'data': [ 'value1', 'value2' ] }
 { 'type': 'TestBase',
@@ -9,6 +10,6 @@ 
   'data': { 'integer': 'int' } }
 { 'union': 'TestUnion',
   'base': 'TestBase',
-  'discriminator': [],
+  'discriminator': {},
   'data': { 'kind1': 'TestTypeA',
             'kind2': 'TestTypeB' } }
diff --git a/tests/qapi-schema/flat-union-base-union.json b/tests/qapi-schema/flat-union-base-union.json
index 838986c..0ba6e28 100644
--- a/tests/qapi-schema/flat-union-base-union.json
+++ b/tests/qapi-schema/flat-union-base-union.json
@@ -1,4 +1,4 @@ 
-# FIXME: the error message needs help: we require the base to be a struct
+# we require the base to be a struct
 { 'enum': 'TestEnum',
   'data': [ 'value1', 'value2' ] }
 { 'type': 'TestTypeA',
diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index e1d35e1..dec8a7c 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -53,8 +53,7 @@ 
   'discriminator': 'enum1',
   'data': { 'value1' : 'UserDefC', 'value2' : 'UserDefB', 'value3' : 'UserDefA' } }

-{ 'union': 'UserDefAlternate',
-  'discriminator': {},
+{ 'alternate': 'UserDefAlternate',
   'data': { 'uda': 'UserDefA', 's': 'str', 'i': 'int' } }

 # for testing native lists
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index b55ab8d..313ecf3 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -10,7 +10,7 @@ 
  OrderedDict([('type', 'UserDefUnionBase'), ('data', OrderedDict([('string', 'str'), ('enum1', 'EnumOne')]))]),
  OrderedDict([('union', 'UserDefFlatUnion'), ('base', 'UserDefUnionBase'), ('discriminator', 'enum1'), ('data', OrderedDict([('value1', 'UserDefA'), ('value2', 'UserDefB'), ('value3', 'UserDefB')]))]),
  OrderedDict([('union', 'UserDefFlatUnion2'), ('base', 'UserDefUnionBase'), ('discriminator', 'enum1'), ('data', OrderedDict([('value1', 'UserDefC'), ('value2', 'UserDefB'), ('value3', 'UserDefA')]))]),
- OrderedDict([('union', 'UserDefAlternate'), ('discriminator', OrderedDict()), ('data', OrderedDict([('uda', 'UserDefA'), ('s', 'str'), ('i', 'int')]))]),
+ OrderedDict([('alternate', 'UserDefAlternate'), ('data', OrderedDict([('uda', 'UserDefA'), ('s', 'str'), ('i', 'int')]))]),
  OrderedDict([('union', 'UserDefNativeListUnion'), ('data', OrderedDict([('integer', ['int']), ('s8', ['int8']), ('s16', ['int16']), ('s32', ['int32']), ('s64', ['int64']), ('u8', ['uint8']), ('u16', ['uint16']), ('u32', ['uint32']), ('u64', ['uint64']), ('number', ['number']), ('boolean', ['bool']), ('string', ['str']), ('sizes', ['size'])]))]),
  OrderedDict([('command', 'user_def_cmd'), ('data', OrderedDict())]),
  OrderedDict([('command', 'user_def_cmd1'), ('data', OrderedDict([('ud1a', 'UserDefOne')]))]),