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 84f0f07..b134f3f 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 915a61b..664ae7b 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 e69de29..fc8b79c 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 573541a..d00491f 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 c8cba3a..052596c 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 505fd57..e69de29 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')]))])]