qapi: Forbid base without discriminator in unions

None of the existing QMP or QGA interfaces uses a union with a
base type but no discriminator; it is easier to avoid this in the
generator to save room for other future extensions more likely to
be useful.  An earlier commit added a union-base-no-discriminator
test to ensure that we eventually give a decent error message;
likewise, removing UserDefUnion outright is okay, because we moved
all the tests we wish to keep into the tests of the simple union
UserDefNativeListUnion in the previous commit.  Now is the time to
actually forbid simple union with base, and remove the last
vestiges from the testsuite.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

6 files changed, 3 insertions, 16 deletions

diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index 84f0f07637..b134f3fa29 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -36,10 +36,6 @@
 { 'type': 'UserDefC',
   'data': { 'string1': 'str', 'string2': 'str' } }
 
-{ 'union': 'UserDefUnion',
-  'base': 'UserDefZero',
-  'data': { 'a' : 'UserDefA', 'b' : 'UserDefB' } }
-
 { 'type': 'UserDefUnionBase',
   'data': { 'string': 'str', 'enum1': 'EnumOne' } }
 
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index 915a61bcd1..664ae7b4b3 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -7,7 +7,6 @@
  OrderedDict([('type', 'UserDefA'), ('data', OrderedDict([('boolean', 'bool')]))]),
  OrderedDict([('type', 'UserDefB'), ('data', OrderedDict([('integer', 'int')]))]),
  OrderedDict([('type', 'UserDefC'), ('data', OrderedDict([('string1', 'str'), ('string2', 'str')]))]),
- OrderedDict([('union', 'UserDefUnion'), ('base', 'UserDefZero'), ('data', OrderedDict([('a', 'UserDefA'), ('b', 'UserDefB')]))]),
  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')]))]),
@@ -24,7 +23,6 @@
  OrderedDict([('event', 'EVENT_C'), ('data', OrderedDict([('*a', 'int'), ('*b', 'UserDefOne'), ('c', 'str')]))]),
  OrderedDict([('event', 'EVENT_D'), ('data', OrderedDict([('a', 'EventStructOne'), ('b', 'str'), ('*c', 'str'), ('*enum3', 'EnumOne')]))])]
 [{'enum_name': 'EnumOne', 'enum_values': ['value1', 'value2', 'value3']},
- {'enum_name': 'UserDefUnionKind', 'enum_values': None},
  {'enum_name': 'UserDefAnonUnionKind', 'enum_values': None},
  {'enum_name': 'UserDefNativeListUnionKind', 'enum_values': None}]
 [OrderedDict([('type', 'NestedEnumsOne'), ('data', OrderedDict([('enum1', 'EnumOne'), ('*enum2', 'EnumOne'), ('enum3', 'EnumOne'), ('*enum4', 'EnumOne')]))]),
diff --git a/tests/qapi-schema/union-base-no-discriminator.err b/tests/qapi-schema/union-base-no-discriminator.err
index e69de29bb2..fc8b79c459 100644
--- a/tests/qapi-schema/union-base-no-discriminator.err
+++ b/tests/qapi-schema/union-base-no-discriminator.err
@@ -0,0 +1 @@
+tests/qapi-schema/union-base-no-discriminator.json:11: Union 'TestUnion' requires a discriminator to go along with base
diff --git a/tests/qapi-schema/union-base-no-discriminator.exit b/tests/qapi-schema/union-base-no-discriminator.exit
index 573541ac97..d00491fd7e 100644
--- a/tests/qapi-schema/union-base-no-discriminator.exit
+++ b/tests/qapi-schema/union-base-no-discriminator.exit
@@ -1 +1 @@
-0
+1
diff --git a/tests/qapi-schema/union-base-no-discriminator.json b/tests/qapi-schema/union-base-no-discriminator.json
index c8cba3ad7c..052596c46e 100644
--- a/tests/qapi-schema/union-base-no-discriminator.json
+++ b/tests/qapi-schema/union-base-no-discriminator.json
@@ -1,4 +1,4 @@
-# FIXME: we should reject simple unions with a base
+# we reject simple unions with a base (or flat unions without discriminator)
 { 'type': 'TestTypeA',
   'data': { 'string': 'str' } }
 
diff --git a/tests/qapi-schema/union-base-no-discriminator.out b/tests/qapi-schema/union-base-no-discriminator.out
index 505fd57dc0..e69de29bb2 100644
--- a/tests/qapi-schema/union-base-no-discriminator.out
+++ b/tests/qapi-schema/union-base-no-discriminator.out
@@ -1,8 +0,0 @@
-[OrderedDict([('type', 'TestTypeA'), ('data', OrderedDict([('string', 'str')]))]),
- OrderedDict([('type', 'TestTypeB'), ('data', OrderedDict([('integer', 'int')]))]),
- OrderedDict([('type', 'Base'), ('data', OrderedDict([('string', 'str')]))]),
- OrderedDict([('union', 'TestUnion'), ('base', 'Base'), ('data', OrderedDict([('value1', 'TestTypeA'), ('value2', 'TestTypeB')]))])]
-[{'enum_name': 'TestUnionKind', 'enum_values': None}]
-[OrderedDict([('type', 'TestTypeA'), ('data', OrderedDict([('string', 'str')]))]),
- OrderedDict([('type', 'TestTypeB'), ('data', OrderedDict([('integer', 'int')]))]),
- OrderedDict([('type', 'Base'), ('data', OrderedDict([('string', 'str')]))])]