qapi: Lift features into QAPISchemaEntity

Commit 6a8c0b5102 "qapi: Add feature flags to struct types" added
features to QAPISchemaObjectType.  Commit a95daa5093 "qapi: Add
feature flags to commands in qapi" added them to QAPISchemaCommand,
duplicating the code.  Tolerable, but the duplication will only get
worse as we add features to more definitions.

To de-duplicate, lift features from QAPISchemaObjectType and
QAPISchemaCommand into QAPISchemaEntity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191024110237.30963-18-armbru@redhat.com>

scripts/qapi/schema.py

@@ -27,8 +27,11 @@ from qapi.parser import QAPISchemaParser
 class QAPISchemaEntity(object):
     meta = None
 
-    def __init__(self, name, info, doc, ifcond=None):
+    def __init__(self, name, info, doc, ifcond=None, features=None):
         assert name is None or isinstance(name, str)
+        for f in features or []:
+            assert isinstance(f, QAPISchemaFeature)
+            f.set_defined_in(name)
         self.name = name
         self._module = None
         # For explicitly defined entities, info points to the (explicit)
@@ -39,6 +42,7 @@ class QAPISchemaEntity(object):
         self.info = info
         self.doc = doc
         self._ifcond = ifcond or []
+        self.features = features or []
         self._checked = False
 
     def c_name(self):
@@ -49,6 +53,10 @@ class QAPISchemaEntity(object):
         if self.info:
             self._module = os.path.relpath(self.info.fname,
                                            os.path.dirname(schema.fname))
+        seen = {}
+        for f in self.features:
+            f.check_clash(self.info, seen)
+
         self._checked = True
 
     def connect_doc(self, doc=None):
@@ -307,7 +315,7 @@ class QAPISchemaObjectType(QAPISchemaType):
         # struct has local_members, optional base, and no variants
         # flat union has base, variants, and no local_members
         # simple union has local_members, variants, and no base
-        QAPISchemaType.__init__(self, name, info, doc, ifcond)
+        QAPISchemaType.__init__(self, name, info, doc, ifcond, features)
         self.meta = 'union' if variants else 'struct'
         assert base is None or isinstance(base, str)
         for m in local_members:
@@ -316,15 +324,11 @@ class QAPISchemaObjectType(QAPISchemaType):
         if variants is not None:
             assert isinstance(variants, QAPISchemaObjectTypeVariants)
             variants.set_defined_in(name)
-        for f in features:
-            assert isinstance(f, QAPISchemaFeature)
-            f.set_defined_in(name)
         self._base_name = base
         self.base = None
         self.local_members = local_members
         self.variants = variants
         self.members = None
-        self.features = features
 
     def check(self, schema):
         # This calls another type T's .check() exactly when the C
@@ -362,11 +366,6 @@ class QAPISchemaObjectType(QAPISchemaType):
             self.variants.check(schema, seen)
             self.variants.check_clash(self.info, seen)
 
-        # Features are in a name space separate from members
-        seen = {}
-        for f in self.features:
-            f.check_clash(self.info, seen)
-
         self.members = members  # mark completed
 
     # Check that the members of this type do not cause duplicate JSON members,
@@ -678,12 +677,9 @@ class QAPISchemaCommand(QAPISchemaEntity):
     def __init__(self, name, info, doc, ifcond, arg_type, ret_type,
                  gen, success_response, boxed, allow_oob, allow_preconfig,
                  features):
-        QAPISchemaEntity.__init__(self, name, info, doc, ifcond)
+        QAPISchemaEntity.__init__(self, name, info, doc, ifcond, features)
         assert not arg_type or isinstance(arg_type, str)
         assert not ret_type or isinstance(ret_type, str)
-        for f in features:
-            assert isinstance(f, QAPISchemaFeature)
-            f.set_defined_in(name)
         self._arg_type_name = arg_type
         self.arg_type = None
         self._ret_type_name = ret_type
@@ -693,7 +689,6 @@ class QAPISchemaCommand(QAPISchemaEntity):
         self.boxed = boxed
         self.allow_oob = allow_oob
         self.allow_preconfig = allow_preconfig
-        self.features = features
 
     def check(self, schema):
         QAPISchemaEntity.check(self, schema)
@@ -723,11 +718,6 @@ class QAPISchemaCommand(QAPISchemaEntity):
                         "command's 'returns' cannot take %s"
                         % self.ret_type.describe())
 
-        # Features are in a name space separate from members
-        seen = {}
-        for f in self.features:
-            f.check_clash(self.info, seen)
-
     def connect_doc(self, doc=None):
         doc = doc or self.doc
         if doc: