qapi/schema: assert inner type of QAPISchemaVariants in check_clash()

QAPISchemaVariant's "variants" field is typed as
List[QAPISchemaVariant], where the typing for QAPISchemaVariant allows
its type field to be any QAPISchemaType.

However, QAPISchemaVariant expects that all of its variants contain the
narrower QAPISchemaObjectType. This relationship is enforced at runtime
in QAPISchemaVariants.check(). This relationship is not embedded in the
type system though, so QAPISchemaVariants.check_clash() needs to
re-assert this property in order to call
QAPISchemaVariant.type.check_clash().

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-19-armbru@redhat.com>

diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 9c138badb030a65e9630dc61e620191bb6812c80..177bfa0d1163431cc2dfe47b449180d734081c4b 100644 (file)
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -716,7 +716,10 @@ class QAPISchemaVariants:
     def check_clash(self, info, seen):
         for v in self.variants:
             # Reset seen map for each variant, since qapi names from one
-            # branch do not affect another branch
+            # branch do not affect another branch.
+            #
+            # v.type's typing is enforced in check() above.
+            assert isinstance(v.type, QAPISchemaObjectType)
             v.type.check_clash(info, dict(seen))