qapi: allow unions to contain further unions

This extends the QAPI schema validation to permit unions inside unions,
provided the checks for clashing fields pass.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230420102619.348173-4-berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

9 files changed, 126 insertions, 0 deletions

diff --git a/tests/qapi-schema/meson.build b/tests/qapi-schema/meson.build
index a06515ca17..af085f745d 100644
--- a/tests/qapi-schema/meson.build
+++ b/tests/qapi-schema/meson.build
@@ -197,6 +197,8 @@ schemas = [
   'union-invalid-data.json',
   'union-invalid-discriminator.json',
   'union-invalid-if-discriminator.json',
+  'union-invalid-union-subfield.json',
+  'union-invalid-union-subtype.json',
   'union-no-base.json',
   'union-optional-discriminator.json',
   'union-string-discriminator.json',
diff --git a/tests/qapi-schema/qapi-schema-test.json b/tests/qapi-schema/qapi-schema-test.json
index 8bbf94834a..8ca977c49d 100644
--- a/tests/qapi-schema/qapi-schema-test.json
+++ b/tests/qapi-schema/qapi-schema-test.json
@@ -114,6 +114,38 @@
 { 'struct': 'UserDefC',
   'data': { 'string1': 'str', 'string2': 'str' } }
 
+# this tests that unions can contain other unions in their branches
+{ 'enum': 'TestUnionEnum',
+  'data': [ 'value-a', 'value-b' ] }
+
+{ 'enum': 'TestUnionEnumA',
+  'data': [ 'value-a1', 'value-a2' ] }
+
+{ 'struct': 'TestUnionTypeA1',
+  'data': { 'integer': 'int',
+            'name': 'str'} }
+
+{ 'struct': 'TestUnionTypeA2',
+  'data': { 'integer': 'int',
+            'size': 'int' } }
+
+{ 'union': 'TestUnionTypeA',
+  'base': { 'type-a': 'TestUnionEnumA' },
+  'discriminator': 'type-a',
+  'data': { 'value-a1': 'TestUnionTypeA1',
+            'value-a2': 'TestUnionTypeA2' } }
+
+{ 'struct': 'TestUnionTypeB',
+  'data': { 'integer': 'int',
+            'onoff': 'bool' } }
+
+{ 'union': 'TestUnionInUnion',
+  'base': { 'type': 'TestUnionEnum' },
+  'discriminator': 'type',
+  'data': { 'value-a': 'TestUnionTypeA',
+            'value-b': 'TestUnionTypeB' } }
+
+
 # for testing use of 'number' within alternates
 { 'alternate': 'AltEnumBool', 'data': { 'e': 'EnumOne', 'b': 'bool' } }
 { 'alternate': 'AltEnumNum', 'data': { 'e': 'EnumOne', 'n': 'number' } }
diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out
index cc34b422e6..e2f0981348 100644
--- a/tests/qapi-schema/qapi-schema-test.out
+++ b/tests/qapi-schema/qapi-schema-test.out
@@ -105,6 +105,35 @@ alternate UserDefAlternate
 object UserDefC
     member string1: str optional=False
     member string2: str optional=False
+enum TestUnionEnum
+    member value-a
+    member value-b
+enum TestUnionEnumA
+    member value-a1
+    member value-a2
+object TestUnionTypeA1
+    member integer: int optional=False
+    member name: str optional=False
+object TestUnionTypeA2
+    member integer: int optional=False
+    member size: int optional=False
+object q_obj_TestUnionTypeA-base
+    member type-a: TestUnionEnumA optional=False
+object TestUnionTypeA
+    base q_obj_TestUnionTypeA-base
+    tag type-a
+    case value-a1: TestUnionTypeA1
+    case value-a2: TestUnionTypeA2
+object TestUnionTypeB
+    member integer: int optional=False
+    member onoff: bool optional=False
+object q_obj_TestUnionInUnion-base
+    member type: TestUnionEnum optional=False
+object TestUnionInUnion
+    base q_obj_TestUnionInUnion-base
+    tag type
+    case value-a: TestUnionTypeA
+    case value-b: TestUnionTypeB
 alternate AltEnumBool
     tag type
     case e: EnumOne
diff --git a/tests/qapi-schema/union-invalid-union-subfield.err b/tests/qapi-schema/union-invalid-union-subfield.err
new file mode 100644
index 0000000000..91aa87bcd8
--- /dev/null
+++ b/tests/qapi-schema/union-invalid-union-subfield.err
@@ -0,0 +1,2 @@
+union-invalid-union-subfield.json: In union 'TestUnion':
+union-invalid-union-subfield.json:25: member 'teeth' of type 'TestTypeFish' collides with base member 'teeth'
diff --git a/tests/qapi-schema/union-invalid-union-subfield.json b/tests/qapi-schema/union-invalid-union-subfield.json
new file mode 100644
index 0000000000..e1639d3a96
--- /dev/null
+++ b/tests/qapi-schema/union-invalid-union-subfield.json
@@ -0,0 +1,30 @@
+# Clash between common member and union variant's variant member
+# Base's member 'teeth' clashes with TestTypeFish's
+
+{ 'enum': 'TestEnum',
+  'data': [ 'animals', 'plants' ] }
+
+{ 'enum': 'TestAnimals',
+  'data': [ 'fish', 'birds'] }
+
+{ 'struct': 'TestTypeFish',
+  'data': { 'scales': 'int', 'teeth': 'int' } }
+
+{ 'struct': 'TestTypeBirds',
+  'data': { 'feathers': 'int' } }
+
+{ 'union': 'TestTypeAnimals',
+  'base': { 'atype': 'TestAnimals' },
+  'discriminator': 'atype',
+  'data': { 'fish': 'TestTypeFish',
+            'birds': 'TestTypeBirds' } }
+
+{ 'struct': 'TestTypePlants',
+  'data': { 'integer': 'int' } }
+
+{ 'union': 'TestUnion',
+  'base': { 'type': 'TestEnum',
+            'teeth': 'int' },
+  'discriminator': 'type',
+  'data': { 'animals': 'TestTypeAnimals',
+            'plants': 'TestTypePlants' } }
diff --git a/tests/qapi-schema/union-invalid-union-subfield.out b/tests/qapi-schema/union-invalid-union-subfield.out
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/qapi-schema/union-invalid-union-subfield.out
diff --git a/tests/qapi-schema/union-invalid-union-subtype.err b/tests/qapi-schema/union-invalid-union-subtype.err
new file mode 100644
index 0000000000..3538dc2e70
--- /dev/null
+++ b/tests/qapi-schema/union-invalid-union-subtype.err
@@ -0,0 +1,2 @@
+union-invalid-union-subtype.json: In union 'TestUnion':
+union-invalid-union-subtype.json:25: base member 'type' of type 'TestTypeA' collides with base member 'type'
diff --git a/tests/qapi-schema/union-invalid-union-subtype.json b/tests/qapi-schema/union-invalid-union-subtype.json
new file mode 100644
index 0000000000..ce1de51d8d
--- /dev/null
+++ b/tests/qapi-schema/union-invalid-union-subtype.json
@@ -0,0 +1,29 @@
+# Clash between common member and union variant's common member
+# Base's member 'type' clashes with TestTypeA's
+
+{ 'enum': 'TestEnum',
+  'data': [ 'value-a', 'value-b' ] }
+
+{ 'enum': 'TestEnumA',
+  'data': [ 'value-a1', 'value-a2' ] }
+
+{ 'struct': 'TestTypeA1',
+  'data': { 'integer': 'int' } }
+
+{ 'struct': 'TestTypeA2',
+  'data': { 'integer': 'int' } }
+
+{ 'union': 'TestTypeA',
+  'base': { 'type': 'TestEnumA' },
+  'discriminator': 'type',
+  'data': { 'value-a1': 'TestTypeA1',
+            'value-a2': 'TestTypeA2' } }
+
+{ 'struct': 'TestTypeB',
+  'data': { 'integer': 'int' } }
+
+{ 'union': 'TestUnion',
+  'base': { 'type': 'TestEnum' },
+  'discriminator': 'type',
+  'data': { 'value-a': 'TestTypeA',
+            'value-b': 'TestTypeB' } }
diff --git a/tests/qapi-schema/union-invalid-union-subtype.out b/tests/qapi-schema/union-invalid-union-subtype.out
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/qapi-schema/union-invalid-union-subtype.out