[PATCH v3 39/47] qapi/introspect.py: add _gen_features helper

[John Snow <jsnow@redhat.com>]

_make_tree might receive a dict or some other type. Adding features
information should arguably be performed by the caller at such a time
when we know the type of the object and don't have to re-interrogate it.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 scripts/qapi/introspect.py | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 7d4dc3f8ee..08b3783ba7 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -51,16 +51,12 @@
 
 
 def _make_tree(obj: Union[_DObject, str], ifcond: List[str],
-               features: List[QAPISchemaFeature],
                extra: Optional[Extra] = None
                ) -> Union[TreeNode, AnnotatedNode]:
     if extra is None:
         extra = {}
     if ifcond:
         extra['if'] = ifcond
-    if features:
-        assert isinstance(obj, dict)
-        obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
     if extra:
         return (obj, extra)
     return obj
@@ -196,6 +192,11 @@ def _use_type(self, typ: QAPISchemaType) -> str:
             return '[' + self._use_type(typ.element_type) + ']'
         return self._name(typ.name)
 
+    @classmethod
+    def _gen_features(cls,
+                      features: List[QAPISchemaFeature]) -> List[TreeNode]:
+        return [_make_tree(f.name, f.ifcond) for f in features]
+
     def _gen_tree(self, name: str, mtype: str, obj: _DObject,
                   ifcond: List[str],
                   features: Optional[List[QAPISchemaFeature]]) -> None:
@@ -208,7 +209,9 @@ def _gen_tree(self, name: str, mtype: str, obj: _DObject,
             name = self._name(name)
         obj['name'] = name
         obj['meta-type'] = mtype
-        self._trees.append(_make_tree(obj, ifcond, features, extra))
+        if features:
+            obj['features'] = self._gen_features(features)
+        self._trees.append(_make_tree(obj, ifcond, extra))
 
     def _gen_member(self,
                     member: QAPISchemaObjectTypeMember) -> TreeNode:
@@ -218,7 +221,9 @@ def _gen_member(self,
         }
         if member.optional:
             obj['default'] = None
-        return _make_tree(obj, member.ifcond, member.features)
+        if member.features:
+            obj['features'] = self._gen_features(member.features)
+        return _make_tree(obj, member.ifcond)
 
     def _gen_variants(self, tag_name: str,
                       variants: List[QAPISchemaVariant]) -> _DObject:
@@ -230,7 +235,7 @@ def _gen_variant(self, variant: QAPISchemaVariant) -> TreeNode:
             'case': variant.name,
             'type': self._use_type(variant.type)
         }
-        return _make_tree(obj, variant.ifcond, None)
+        return _make_tree(obj, variant.ifcond)
 
     def visit_builtin_type(self, name: str, info: Optional[QAPISourceInfo],
                            json_type: str) -> None:
-- 
2.26.2