qapi: Add feature flags to remaining definitions

In v4.1.0, we added feature flags just to struct types (commit
6a8c0b5102^..f3ed93d545), to satisfy an immediate need (commit
c9d4070991 "file-posix: Add dynamic-auto-read-only QAPI feature").  In
v4.2.0, we added them to commands (commit 23394b4c39 "qapi: Add
feature flags to commands") to satisfy another immediate need (commit
d76744e65e "qapi: Allow introspecting fix for savevm's cooperation
with blockdev").

Add them to the remaining definitions: enumeration types, union types,
alternate types, and events.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-13-armbru@redhat.com>

7 files changed, 80 insertions, 74 deletions

diff --git a/scripts/qapi/doc.py b/scripts/qapi/doc.py
index 1787a53d91..36e823338b 100644
--- a/scripts/qapi/doc.py
+++ b/scripts/qapi/doc.py
@@ -243,7 +243,7 @@ class QAPISchemaGenDocVisitor(QAPISchemaVisitor):
     def write(self, output_dir):
         self._gen.write(output_dir)
 
-    def visit_enum_type(self, name, info, ifcond, members, prefix):
+    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
         doc = self.cur_doc
         self._gen.add(texi_type('Enum', doc, ifcond,
                                 texi_members(doc, 'Values',
@@ -257,7 +257,7 @@ class QAPISchemaGenDocVisitor(QAPISchemaVisitor):
         self._gen.add(texi_type('Object', doc, ifcond,
                                 texi_members(doc, 'Members', base, variants)))
 
-    def visit_alternate_type(self, name, info, ifcond, variants):
+    def visit_alternate_type(self, name, info, ifcond, features, variants):
         doc = self.cur_doc
         self._gen.add(texi_type('Alternate', doc, ifcond,
                                 texi_members(doc, 'Members')))
@@ -270,7 +270,7 @@ class QAPISchemaGenDocVisitor(QAPISchemaVisitor):
                                texi_arguments(doc,
                                               arg_type if boxed else None)))
 
-    def visit_event(self, name, info, ifcond, arg_type, boxed):
+    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
         doc = self.cur_doc
         self._gen.add(texi_msg('Event', doc, ifcond,
                                texi_arguments(doc,
diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py
index a98b9f5099..b544af5a1c 100644
--- a/scripts/qapi/events.py
+++ b/scripts/qapi/events.py
@@ -189,7 +189,7 @@ void %(event_emit)s(%(event_enum)s event, QDict *qdict);
                              event_emit=self._event_emit_name,
                              event_enum=self._event_enum_name))
 
-    def visit_event(self, name, info, ifcond, arg_type, boxed):
+    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
         with ifcontext(ifcond, self._genh, self._genc):
             self._genh.add(gen_event_send_decl(name, arg_type, boxed))
             self._genc.add(gen_event_send(name, arg_type, boxed,
diff --git a/scripts/qapi/expr.py b/scripts/qapi/expr.py
index fecf466fa7..f9c4448980 100644
--- a/scripts/qapi/expr.py
+++ b/scripts/qapi/expr.py
@@ -219,7 +219,6 @@ def check_struct(expr, info):
 
     check_type(members, info, "'data'", allow_dict=name)
     check_type(expr.get('base'), info, "'base'")
-    check_features(expr.get('features'), info)
 
 
 def check_union(expr, info):
@@ -267,7 +266,6 @@ def check_command(expr, info):
         raise QAPISemError(info, "'boxed': true requires 'data'")
     check_type(args, info, "'data'", allow_dict=not boxed)
     check_type(rets, info, "'returns'", allow_array=True)
-    check_features(expr.get('features'), info)
 
 
 def check_event(expr, info):
@@ -319,18 +317,18 @@ def check_exprs(exprs):
 
         if meta == 'enum':
             check_keys(expr, info, meta,
-                       ['enum', 'data'], ['if', 'prefix'])
+                       ['enum', 'data'], ['if', 'features', 'prefix'])
             check_enum(expr, info)
         elif meta == 'union':
             check_keys(expr, info, meta,
                        ['union', 'data'],
-                       ['base', 'discriminator', 'if'])
+                       ['base', 'discriminator', 'if', 'features'])
             normalize_members(expr.get('base'))
             normalize_members(expr['data'])
             check_union(expr, info)
         elif meta == 'alternate':
             check_keys(expr, info, meta,
-                       ['alternate', 'data'], ['if'])
+                       ['alternate', 'data'], ['if', 'features'])
             normalize_members(expr['data'])
             check_alternate(expr, info)
         elif meta == 'struct':
@@ -348,13 +346,14 @@ def check_exprs(exprs):
             check_command(expr, info)
         elif meta == 'event':
             check_keys(expr, info, meta,
-                       ['event'], ['data', 'boxed', 'if'])
+                       ['event'], ['data', 'boxed', 'if', 'features'])
             normalize_members(expr.get('data'))
             check_event(expr, info)
         else:
             assert False, 'unexpected meta type'
 
         check_if(expr, info, meta)
+        check_features(expr.get('features'), info)
         check_flags(expr, info)
 
     return exprs
diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index b5537eddc0..2e9e00aa1f 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -144,7 +144,7 @@ const QLitObject %(c_name)s = %(c_string)s;
             return '[' + self._use_type(typ.element_type) + ']'
         return self._name(typ.name)
 
-    def _gen_qlit(self, name, mtype, obj, ifcond):
+    def _gen_qlit(self, name, mtype, obj, ifcond, features):
         extra = {}
         if mtype not in ('command', 'event', 'builtin', 'array'):
             if not self._unmask:
@@ -154,6 +154,8 @@ const QLitObject %(c_name)s = %(c_string)s;
             name = self._name(name)
         obj['name'] = name
         obj['meta-type'] = mtype
+        if features:
+            obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
         if ifcond:
             extra['if'] = ifcond
         if extra:
@@ -178,18 +180,18 @@ const QLitObject %(c_name)s = %(c_string)s;
                 {'if': variant.ifcond})
 
     def visit_builtin_type(self, name, info, json_type):
-        self._gen_qlit(name, 'builtin', {'json-type': json_type}, [])
+        self._gen_qlit(name, 'builtin', {'json-type': json_type}, [], None)
 
-    def visit_enum_type(self, name, info, ifcond, members, prefix):
+    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
         self._gen_qlit(name, 'enum',
                        {'values':
                         [(m.name, {'if': m.ifcond}) for m in members]},
-                       ifcond)
+                       ifcond, features)
 
     def visit_array_type(self, name, info, ifcond, element_type):
         element = self._use_type(element_type)
         self._gen_qlit('[' + element + ']', 'array', {'element-type': element},
-                       ifcond)
+                       ifcond, None)
 
     def visit_object_type_flat(self, name, info, ifcond, members, variants,
                                features):
@@ -197,16 +199,15 @@ const QLitObject %(c_name)s = %(c_string)s;
         if variants:
             obj.update(self._gen_variants(variants.tag_member.name,
                                           variants.variants))
-        if features:
-            obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
 
-        self._gen_qlit(name, 'object', obj, ifcond)
+        self._gen_qlit(name, 'object', obj, ifcond, features)
 
-    def visit_alternate_type(self, name, info, ifcond, variants):
+    def visit_alternate_type(self, name, info, ifcond, features, variants):
         self._gen_qlit(name, 'alternate',
                        {'members': [
                            ({'type': self._use_type(m.type)}, {'if': m.ifcond})
-                           for m in variants.variants]}, ifcond)
+                           for m in variants.variants]},
+                       ifcond, features)
 
     def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
                       success_response, boxed, allow_oob, allow_preconfig,
@@ -217,16 +218,12 @@ const QLitObject %(c_name)s = %(c_string)s;
                'ret-type': self._use_type(ret_type)}
         if allow_oob:
             obj['allow-oob'] = allow_oob
+        self._gen_qlit(name, 'command', obj, ifcond, features)
 
-        if features:
-            obj['features'] = [(f.name, {'if': f.ifcond}) for f in features]
-
-        self._gen_qlit(name, 'command', obj, ifcond)
-
-    def visit_event(self, name, info, ifcond, arg_type, boxed):
+    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
         arg_type = arg_type or self._schema.the_empty_object_type
         self._gen_qlit(name, 'event', {'arg-type': self._use_type(arg_type)},
-                       ifcond)
+                       ifcond, features)
 
 
 def gen_introspect(schema, output_dir, prefix, opt_unmask):
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 2a2b495987..22238005ff 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -109,7 +109,7 @@ class QAPISchemaVisitor:
     def visit_builtin_type(self, name, info, json_type):
         pass
 
-    def visit_enum_type(self, name, info, ifcond, members, prefix):
+    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
         pass
 
     def visit_array_type(self, name, info, ifcond, element_type):
@@ -123,7 +123,7 @@ class QAPISchemaVisitor:
                                features):
         pass
 
-    def visit_alternate_type(self, name, info, ifcond, variants):
+    def visit_alternate_type(self, name, info, ifcond, features, variants):
         pass
 
     def visit_command(self, name, info, ifcond, arg_type, ret_type, gen,
@@ -131,7 +131,7 @@ class QAPISchemaVisitor:
                       features):
         pass
 
-    def visit_event(self, name, info, ifcond, arg_type, boxed):
+    def visit_event(self, name, info, ifcond, features, arg_type, boxed):
         pass
 
 
@@ -234,8 +234,8 @@ class QAPISchemaBuiltinType(QAPISchemaType):
 class QAPISchemaEnumType(QAPISchemaType):
     meta = 'enum'
 
-    def __init__(self, name, info, doc, ifcond, members, prefix):
-        super().__init__(name, info, doc, ifcond)
+    def __init__(self, name, info, doc, ifcond, features, members, prefix):
+        super().__init__(name, info, doc, ifcond, features)
         for m in members:
             assert isinstance(m, QAPISchemaEnumMember)
             m.set_defined_in(name)
@@ -271,15 +271,16 @@ class QAPISchemaEnumType(QAPISchemaType):
 
     def visit(self, visitor):
         super().visit(visitor)
-        visitor.visit_enum_type(self.name, self.info, self.ifcond,
-                                self.members, self.prefix)
+        visitor.visit_enum_type(
+            self.name, self.info, self.ifcond, self.features,
+            self.members, self.prefix)
 
 
 class QAPISchemaArrayType(QAPISchemaType):
     meta = 'array'
 
     def __init__(self, name, info, element_type):
-        super().__init__(name, info, None, None)
+        super().__init__(name, info, None)
         assert isinstance(element_type, str)
         self._element_type_name = element_type
         self.element_type = None
@@ -325,8 +326,8 @@ class QAPISchemaArrayType(QAPISchemaType):
 
 
 class QAPISchemaObjectType(QAPISchemaType):
-    def __init__(self, name, info, doc, ifcond,
-                 base, local_members, variants, features):
+    def __init__(self, name, info, doc, ifcond, features,
+                 base, local_members, variants):
         # 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
@@ -622,8 +623,8 @@ class QAPISchemaObjectTypeVariant(QAPISchemaObjectTypeMember):
 class QAPISchemaAlternateType(QAPISchemaType):
     meta = 'alternate'
 
-    def __init__(self, name, info, doc, ifcond, variants):
-        super().__init__(name, info, doc, ifcond)
+    def __init__(self, name, info, doc, ifcond, features, variants):
+        super().__init__(name, info, doc, ifcond, features)
         assert isinstance(variants, QAPISchemaObjectTypeVariants)
         assert variants.tag_member
         variants.set_defined_in(name)
@@ -683,16 +684,16 @@ class QAPISchemaAlternateType(QAPISchemaType):
 
     def visit(self, visitor):
         super().visit(visitor)
-        visitor.visit_alternate_type(self.name, self.info, self.ifcond,
-                                     self.variants)
+        visitor.visit_alternate_type(
+            self.name, self.info, self.ifcond, self.features, self.variants)
 
 
 class QAPISchemaCommand(QAPISchemaEntity):
     meta = 'command'
 
-    def __init__(self, name, info, doc, ifcond, arg_type, ret_type,
-                 gen, success_response, boxed, allow_oob, allow_preconfig,
-                 features):
+    def __init__(self, name, info, doc, ifcond, features,
+                 arg_type, ret_type,
+                 gen, success_response, boxed, allow_oob, allow_preconfig):
         super().__init__(name, info, doc, ifcond, features)
         assert not arg_type or isinstance(arg_type, str)
         assert not ret_type or isinstance(ret_type, str)
@@ -755,8 +756,8 @@ class QAPISchemaCommand(QAPISchemaEntity):
 class QAPISchemaEvent(QAPISchemaEntity):
     meta = 'event'
 
-    def __init__(self, name, info, doc, ifcond, arg_type, boxed):
-        super().__init__(name, info, doc, ifcond)
+    def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
+        super().__init__(name, info, doc, ifcond, features)
         assert not arg_type or isinstance(arg_type, str)
         self._arg_type_name = arg_type
         self.arg_type = None
@@ -787,8 +788,9 @@ class QAPISchemaEvent(QAPISchemaEntity):
 
     def visit(self, visitor):
         super().visit(visitor)
-        visitor.visit_event(self.name, self.info, self.ifcond,
-                            self.arg_type, self.boxed)
+        visitor.visit_event(
+            self.name, self.info, self.ifcond, self.features,
+            self.arg_type, self.boxed)
 
 
 class QAPISchema:
@@ -893,7 +895,7 @@ class QAPISchema:
                   ('null',   'null',    'QNull' + pointer_suffix)]:
             self._def_builtin_type(*t)
         self.the_empty_object_type = QAPISchemaObjectType(
-            'q_empty', None, None, None, None, [], None, [])
+            'q_empty', None, None, None, None, None, [], None)
         self._def_entity(self.the_empty_object_type)
 
         qtypes = ['none', 'qnull', 'qnum', 'qstring', 'qdict', 'qlist',
@@ -901,10 +903,11 @@ class QAPISchema:
         qtype_values = self._make_enum_members(
             [{'name': n} for n in qtypes], None)
 
-        self._def_entity(QAPISchemaEnumType('QType', None, None, None,
+        self._def_entity(QAPISchemaEnumType('QType', None, None, None, None,
                                             qtype_values, 'QTYPE'))
 
-    def _make_features(self, features, info):
+    def _make_features(self, expr, info):
+        features = expr.get('features', [])
         return [QAPISchemaFeature(f['name'], info, f.get('if'))
                 for f in features]
 
@@ -916,7 +919,8 @@ class QAPISchema:
         # See also QAPISchemaObjectTypeMember.describe()
         name = name + 'Kind'    # reserved by check_defn_name_str()
         self._def_entity(QAPISchemaEnumType(
-            name, info, None, ifcond, self._make_enum_members(values, info),
+            name, info, None, ifcond, None,
+            self._make_enum_members(values, info),
             None))
         return name
 
@@ -944,8 +948,8 @@ class QAPISchema:
             # TODO kill simple unions or implement the disjunction
             assert (ifcond or []) == typ._ifcond # pylint: disable=protected-access
         else:
-            self._def_entity(QAPISchemaObjectType(name, info, None, ifcond,
-                                                  None, members, None, []))
+            self._def_entity(QAPISchemaObjectType(
+                name, info, None, ifcond, None, None, members, None))
         return name
 
     def _def_enum_type(self, expr, info, doc):
@@ -953,8 +957,9 @@ class QAPISchema:
         data = expr['data']
         prefix = expr.get('prefix')
         ifcond = expr.get('if')
+        features = self._make_features(expr, info)
         self._def_entity(QAPISchemaEnumType(
-            name, info, doc, ifcond,
+            name, info, doc, ifcond, features,
             self._make_enum_members(data, info), prefix))
 
     def _make_member(self, name, typ, ifcond, info):
@@ -976,12 +981,11 @@ class QAPISchema:
         base = expr.get('base')
         data = expr['data']
         ifcond = expr.get('if')
-        features = expr.get('features', [])
+        features = self._make_features(expr, info)
         self._def_entity(QAPISchemaObjectType(
-            name, info, doc, ifcond, base,
+            name, info, doc, ifcond, features, base,
             self._make_members(data, info),
-            None,
-            self._make_features(features, info)))
+            None))
 
     def _make_variant(self, case, typ, ifcond, info):
         return QAPISchemaObjectTypeVariant(case, info, typ, ifcond)
@@ -1000,6 +1004,7 @@ class QAPISchema:
         data = expr['data']
         base = expr.get('base')
         ifcond = expr.get('if')
+        features = self._make_features(expr, info)
         tag_name = expr.get('discriminator')
         tag_member = None
         if isinstance(base, dict):
@@ -1020,21 +1025,22 @@ class QAPISchema:
             tag_member = QAPISchemaObjectTypeMember('type', info, typ, False)
             members = [tag_member]
         self._def_entity(
-            QAPISchemaObjectType(name, info, doc, ifcond, base, members,
+            QAPISchemaObjectType(name, info, doc, ifcond, features,
+                                 base, members,
                                  QAPISchemaObjectTypeVariants(
-                                     tag_name, info, tag_member, variants),
-                                 []))
+                                     tag_name, info, tag_member, variants)))
 
     def _def_alternate_type(self, expr, info, doc):
         name = expr['alternate']
         data = expr['data']
         ifcond = expr.get('if')
+        features = self._make_features(expr, info)
         variants = [self._make_variant(key, value['type'], value.get('if'),
                                        info)
                     for (key, value) in data.items()]
         tag_member = QAPISchemaObjectTypeMember('type', info, 'QType', False)
         self._def_entity(
-            QAPISchemaAlternateType(name, info, doc, ifcond,
+            QAPISchemaAlternateType(name, info, doc, ifcond, features,
                                     QAPISchemaObjectTypeVariants(
                                         None, info, tag_member, variants)))
 
@@ -1048,27 +1054,31 @@ class QAPISchema:
         allow_oob = expr.get('allow-oob', False)
         allow_preconfig = expr.get('allow-preconfig', False)
         ifcond = expr.get('if')
-        features = expr.get('features', [])
+        features = self._make_features(expr, info)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
-                name, info, ifcond, 'arg', self._make_members(data, info))
+                name, info, ifcond,
+                'arg', self._make_members(data, info))
         if isinstance(rets, list):
             assert len(rets) == 1
             rets = self._make_array_type(rets[0], info)
-        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, data, rets,
+        self._def_entity(QAPISchemaCommand(name, info, doc, ifcond, features,
+                                           data, rets,
                                            gen, success_response,
-                                           boxed, allow_oob, allow_preconfig,
-                                           self._make_features(features, info)))
+                                           boxed, allow_oob, allow_preconfig))
 
     def _def_event(self, expr, info, doc):
         name = expr['event']
         data = expr.get('data')
         boxed = expr.get('boxed', False)
         ifcond = expr.get('if')
+        features = self._make_features(expr, info)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
-                name, info, ifcond, 'arg', self._make_members(data, info))
-        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, data, boxed))
+                name, info, ifcond,
+                'arg', self._make_members(data, info))
+        self._def_entity(QAPISchemaEvent(name, info, doc, ifcond, features,
+                                         data, boxed))
 
     def _def_exprs(self, exprs):
         for expr_elem in exprs:
diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index 3c83b6e4be..d0d5c03646 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -278,7 +278,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
         self._genh.add(gen_type_cleanup_decl(name))
         self._genc.add(gen_type_cleanup(name))
 
-    def visit_enum_type(self, name, info, ifcond, members, prefix):
+    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
         with ifcontext(ifcond, self._genh, self._genc):
             self._genh.preamble_add(gen_enum(name, members, prefix))
             self._genc.add(gen_enum_lookup(name, members, prefix))
@@ -306,7 +306,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
                 # implicit types won't be directly allocated/freed
                 self._gen_type_cleanup(name)
 
-    def visit_alternate_type(self, name, info, ifcond, variants):
+    def visit_alternate_type(self, name, info, ifcond, features, variants):
         with ifcontext(ifcond, self._genh):
             self._genh.preamble_add(gen_fwd_object_or_array(name))
         self._genh.add(gen_object(name, ifcond, None,
diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py
index 421e5bd8cd..6e5ed781d7 100644
--- a/scripts/qapi/visit.py
+++ b/scripts/qapi/visit.py
@@ -316,7 +316,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
 ''',
                                       types=types))
 
-    def visit_enum_type(self, name, info, ifcond, members, prefix):
+    def visit_enum_type(self, name, info, ifcond, features, members, prefix):
         with ifcontext(ifcond, self._genh, self._genc):
             self._genh.add(gen_visit_decl(name, scalar=True))
             self._genc.add(gen_visit_enum(name))
@@ -342,7 +342,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
                 self._genh.add(gen_visit_decl(name))
                 self._genc.add(gen_visit_object(name, base, members, variants))
 
-    def visit_alternate_type(self, name, info, ifcond, variants):
+    def visit_alternate_type(self, name, info, ifcond, features, variants):
         with ifcontext(ifcond, self._genh, self._genc):
             self._genh.add(gen_visit_decl(name))
             self._genc.add(gen_visit_alternate(name, variants))