Merge tag 'pull-qapi-2024-05-06' of https://repo.or.cz/qemu/armbru into staging

QAPI patches patches for 2024-05-06

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# gpg: Signature made Mon 06 May 2024 04:01:20 AM PDT
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]

* tag 'pull-qapi-2024-05-06' of https://repo.or.cz/qemu/armbru:
  qapi: Simplify QAPISchemaVariants @tag_member
  qapi: Move conditional code from QAPISchemaVariants to its subtypes
  qapi: Rename QAPISchemaAlternateType.variants to .alternatives
  qapi: Rename QAPISchemaObjectType.variants to .branches
  qapi: Rename visitor parameter @variants to @alternatives
  qapi: Rename visitor parameter @variants to @branches
  qapi: New QAPISchemaBranches, QAPISchemaAlternatives

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

9 files changed, 164 insertions, 148 deletions

diff --git a/docs/sphinx/qapidoc.py b/docs/sphinx/qapidoc.py
index 8d428c6..f270b49 100644
--- a/docs/sphinx/qapidoc.py
+++ b/docs/sphinx/qapidoc.py
@@ -145,22 +145,22 @@ class QAPISchemaGenRSTVisitor(QAPISchemaVisitor):
             term.extend(self._nodes_for_ifcond(member.ifcond))
         return term
 
-    def _nodes_for_variant_when(self, variants, variant):
+    def _nodes_for_variant_when(self, branches, variant):
         """Return list of Text, literal nodes for variant 'when' clause
 
         Return a list of doctree nodes which give text like
         'when tagname is variant (If: ...)' suitable for use in
-        the 'variants' part of a definition list.
+        the 'branches' part of a definition list.
         """
         term = [nodes.Text(' when '),
-                nodes.literal('', variants.tag_member.name),
+                nodes.literal('', branches.tag_member.name),
                 nodes.Text(' is '),
                 nodes.literal('', '"%s"' % variant.name)]
         if variant.ifcond.is_present():
             term.extend(self._nodes_for_ifcond(variant.ifcond))
         return term
 
-    def _nodes_for_members(self, doc, what, base=None, variants=None):
+    def _nodes_for_members(self, doc, what, base=None, branches=None):
         """Return list of doctree nodes for the table of members"""
         dlnode = nodes.definition_list()
         for section in doc.args.values():
@@ -178,14 +178,14 @@ class QAPISchemaGenRSTVisitor(QAPISchemaVisitor):
                                          nodes.literal('', base.doc_type())],
                                         None)
 
-        if variants:
-            for v in variants.variants:
+        if branches:
+            for v in branches.variants:
                 if v.type.name == 'q_empty':
                     continue
                 assert not v.type.is_implicit()
                 term = [nodes.Text('The members of '),
                         nodes.literal('', v.type.doc_type())]
-                term.extend(self._nodes_for_variant_when(variants, v))
+                term.extend(self._nodes_for_variant_when(branches, v))
                 dlnode += self._make_dlitem(term, None)
 
         if not dlnode.children:
@@ -308,17 +308,18 @@ class QAPISchemaGenRSTVisitor(QAPISchemaVisitor):
                       + self._nodes_for_if_section(ifcond))
 
     def visit_object_type(self, name, info, ifcond, features,
-                          base, members, variants):
+                          base, members, branches):
         doc = self._cur_doc
         if base and base.is_implicit():
             base = None
         self._add_doc('Object',
-                      self._nodes_for_members(doc, 'Members', base, variants)
+                      self._nodes_for_members(doc, 'Members', base, branches)
                       + self._nodes_for_features(doc)
                       + self._nodes_for_sections(doc)
                       + self._nodes_for_if_section(ifcond))
 
-    def visit_alternate_type(self, name, info, ifcond, features, variants):
+    def visit_alternate_type(self, name, info, ifcond, features,
+                             alternatives):
         doc = self._cur_doc
         self._add_doc('Alternate',
                       self._nodes_for_members(doc, 'Members')
diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index d1fdf41..79951a8 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -64,7 +64,7 @@ def gen_call(name: str,
         assert arg_type
         argstr = '&arg, '
     elif arg_type:
-        assert not arg_type.variants
+        assert not arg_type.branches
         for memb in arg_type.members:
             assert not memb.ifcond.is_present()
             if memb.need_has():
diff --git a/scripts/qapi/events.py b/scripts/qapi/events.py
index 3cf01e9..d1f6399 100644
--- a/scripts/qapi/events.py
+++ b/scripts/qapi/events.py
@@ -51,7 +51,7 @@ def gen_param_var(typ: QAPISchemaObjectType) -> str:
 
     Initialize it with the function arguments defined in `gen_event_send`.
     """
-    assert not typ.variants
+    assert not typ.branches
     ret = mcgen('''
     %(c_name)s param = {
 ''',
diff --git a/scripts/qapi/gen.py b/scripts/qapi/gen.py
index 5412716..6a8abe0 100644
--- a/scripts/qapi/gen.py
+++ b/scripts/qapi/gen.py
@@ -118,7 +118,7 @@ def build_params(arg_type: Optional[QAPISchemaObjectType],
         ret += '%s arg' % arg_type.c_param_type()
         sep = ', '
     elif arg_type:
-        assert not arg_type.variants
+        assert not arg_type.branches
         for memb in arg_type.members:
             assert not memb.ifcond.is_present()
             ret += sep
diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 4679b1b..86c075a 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -26,6 +26,8 @@ from .common import c_name, mcgen
 from .gen import QAPISchemaMonolithicCVisitor
 from .schema import (
     QAPISchema,
+    QAPISchemaAlternatives,
+    QAPISchemaBranches,
     QAPISchemaArrayType,
     QAPISchemaBuiltinType,
     QAPISchemaEntity,
@@ -36,7 +38,6 @@ from .schema import (
     QAPISchemaObjectTypeMember,
     QAPISchemaType,
     QAPISchemaVariant,
-    QAPISchemaVariants,
 )
 from .source import QAPISourceInfo
 
@@ -335,24 +336,24 @@ const QLitObject %(c_name)s = %(c_string)s;
                                ifcond: QAPISchemaIfCond,
                                features: List[QAPISchemaFeature],
                                members: List[QAPISchemaObjectTypeMember],
-                               variants: Optional[QAPISchemaVariants]) -> None:
+                               branches: Optional[QAPISchemaBranches]) -> None:
         obj: SchemaInfoObject = {
             'members': [self._gen_object_member(m) for m in members]
         }
-        if variants:
-            obj['tag'] = variants.tag_member.name
-            obj['variants'] = [self._gen_variant(v) for v in variants.variants]
+        if branches:
+            obj['tag'] = branches.tag_member.name
+            obj['variants'] = [self._gen_variant(v) for v in branches.variants]
         self._gen_tree(name, 'object', obj, ifcond, features)
 
     def visit_alternate_type(self, name: str, info: Optional[QAPISourceInfo],
                              ifcond: QAPISchemaIfCond,
                              features: List[QAPISchemaFeature],
-                             variants: QAPISchemaVariants) -> None:
+                             alternatives: QAPISchemaAlternatives) -> None:
         self._gen_tree(
             name, 'alternate',
             {'members': [Annotated({'type': self._use_type(m.type)},
                                    m.ifcond)
-                         for m in variants.variants]},
+                         for m in alternatives.variants]},
             ifcond, features
         )
 
diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
index 5924947..721c470 100644
--- a/scripts/qapi/schema.py
+++ b/scripts/qapi/schema.py
@@ -215,7 +215,7 @@ class QAPISchemaVisitor:
         features: List[QAPISchemaFeature],
         base: Optional[QAPISchemaObjectType],
         members: List[QAPISchemaObjectTypeMember],
-        variants: Optional[QAPISchemaVariants],
+        branches: Optional[QAPISchemaBranches],
     ) -> None:
         pass
 
@@ -226,7 +226,7 @@ class QAPISchemaVisitor:
         ifcond: QAPISchemaIfCond,
         features: List[QAPISchemaFeature],
         members: List[QAPISchemaObjectTypeMember],
-        variants: Optional[QAPISchemaVariants],
+        branches: Optional[QAPISchemaBranches],
     ) -> None:
         pass
 
@@ -236,7 +236,7 @@ class QAPISchemaVisitor:
         info: Optional[QAPISourceInfo],
         ifcond: QAPISchemaIfCond,
         features: List[QAPISchemaFeature],
-        variants: QAPISchemaVariants,
+        alternatives: QAPISchemaAlternatives,
     ) -> None:
         pass
 
@@ -524,20 +524,20 @@ class QAPISchemaObjectType(QAPISchemaType):
         features: Optional[List[QAPISchemaFeature]],
         base: Optional[str],
         local_members: List[QAPISchemaObjectTypeMember],
-        variants: Optional[QAPISchemaVariants],
+        branches: Optional[QAPISchemaBranches],
     ):
-        # struct has local_members, optional base, and no variants
-        # union has base, variants, and no local_members
+        # struct has local_members, optional base, and no branches
+        # union has base, branches, and no local_members
         super().__init__(name, info, doc, ifcond, features)
-        self.meta = 'union' if variants else 'struct'
+        self.meta = 'union' if branches else 'struct'
         for m in local_members:
             m.set_defined_in(name)
-        if variants is not None:
-            variants.set_defined_in(name)
+        if branches is not None:
+            branches.set_defined_in(name)
         self._base_name = base
         self.base = None
         self.local_members = local_members
-        self.variants = variants
+        self.branches = branches
         self.members: List[QAPISchemaObjectTypeMember]
         self._check_complete = False
 
@@ -561,7 +561,7 @@ class QAPISchemaObjectType(QAPISchemaType):
             self.base = schema.resolve_type(self._base_name, self.info,
                                             "'base'")
             if (not isinstance(self.base, QAPISchemaObjectType)
-                    or self.base.variants):
+                    or self.base.branches):
                 raise QAPISemError(
                     self.info,
                     "'base' requires a struct type, %s isn't"
@@ -577,9 +577,9 @@ class QAPISchemaObjectType(QAPISchemaType):
         # Cast down to the subtype.
         members = cast(List[QAPISchemaObjectTypeMember], list(seen.values()))
 
-        if self.variants:
-            self.variants.check(schema, seen)
-            self.variants.check_clash(self.info, seen)
+        if self.branches:
+            self.branches.check(schema, seen)
+            self.branches.check_clash(self.info, seen)
 
         self.members = members
         self._check_complete = True  # mark completed
@@ -595,8 +595,8 @@ class QAPISchemaObjectType(QAPISchemaType):
         assert self._checked
         for m in self.members:
             m.check_clash(info, seen)
-        if self.variants:
-            self.variants.check_clash(info, seen)
+        if self.branches:
+            self.branches.check_clash(info, seen)
 
     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
         super().connect_doc(doc)
@@ -612,7 +612,7 @@ class QAPISchemaObjectType(QAPISchemaType):
         return self.name.startswith('q_')
 
     def is_empty(self) -> bool:
-        return not self.members and not self.variants
+        return not self.members and not self.branches
 
     def has_conditional_members(self) -> bool:
         return any(m.ifcond.is_present() for m in self.members)
@@ -635,10 +635,10 @@ class QAPISchemaObjectType(QAPISchemaType):
         super().visit(visitor)
         visitor.visit_object_type(
             self.name, self.info, self.ifcond, self.features,
-            self.base, self.local_members, self.variants)
+            self.base, self.local_members, self.branches)
         visitor.visit_object_type_flat(
             self.name, self.info, self.ifcond, self.features,
-            self.members, self.variants)
+            self.members, self.branches)
 
 
 class QAPISchemaAlternateType(QAPISchemaType):
@@ -651,25 +651,25 @@ class QAPISchemaAlternateType(QAPISchemaType):
         doc: Optional[QAPIDoc],
         ifcond: Optional[QAPISchemaIfCond],
         features: List[QAPISchemaFeature],
-        variants: QAPISchemaVariants,
+        alternatives: QAPISchemaAlternatives,
     ):
         super().__init__(name, info, doc, ifcond, features)
-        assert variants.tag_member
-        variants.set_defined_in(name)
-        variants.tag_member.set_defined_in(self.name)
-        self.variants = variants
+        assert alternatives.tag_member
+        alternatives.set_defined_in(name)
+        alternatives.tag_member.set_defined_in(self.name)
+        self.alternatives = alternatives
 
     def check(self, schema: QAPISchema) -> None:
         super().check(schema)
-        self.variants.tag_member.check(schema)
-        # Not calling self.variants.check_clash(), because there's nothing
-        # to clash with
-        self.variants.check(schema, {})
+        self.alternatives.tag_member.check(schema)
+        # Not calling self.alternatives.check_clash(), because there's
+        # nothing to clash with
+        self.alternatives.check(schema, {})
         # Alternate branch names have no relation to the tag enum values;
         # so we have to check for potential name collisions ourselves.
         seen: Dict[str, QAPISchemaMember] = {}
         types_seen: Dict[str, str] = {}
-        for v in self.variants.variants:
+        for v in self.alternatives.variants:
             v.check_clash(self.info, seen)
             qtype = v.type.alternate_qtype()
             if not qtype:
@@ -700,7 +700,7 @@ class QAPISchemaAlternateType(QAPISchemaType):
     def connect_doc(self, doc: Optional[QAPIDoc] = None) -> None:
         super().connect_doc(doc)
         doc = doc or self.doc
-        for v in self.variants.variants:
+        for v in self.alternatives.variants:
             v.connect_doc(doc)
 
     def c_type(self) -> str:
@@ -712,94 +712,86 @@ class QAPISchemaAlternateType(QAPISchemaType):
     def visit(self, visitor: QAPISchemaVisitor) -> None:
         super().visit(visitor)
         visitor.visit_alternate_type(
-            self.name, self.info, self.ifcond, self.features, self.variants)
+            self.name, self.info, self.ifcond, self.features,
+            self.alternatives)
 
 
 class QAPISchemaVariants:
     def __init__(
         self,
-        tag_name: Optional[str],
         info: QAPISourceInfo,
-        tag_member: Optional[QAPISchemaObjectTypeMember],
         variants: List[QAPISchemaVariant],
     ):
-        # Unions pass tag_name but not tag_member.
-        # Alternates pass tag_member but not tag_name.
-        # After check(), tag_member is always set.
-        assert bool(tag_member) != bool(tag_name)
-        assert (isinstance(tag_name, str) or
-                isinstance(tag_member, QAPISchemaObjectTypeMember))
-        self._tag_name = tag_name
         self.info = info
-        self._tag_member = tag_member
+        self.tag_member: QAPISchemaObjectTypeMember
         self.variants = variants
 
-    @property
-    def tag_member(self) -> QAPISchemaObjectTypeMember:
-        if self._tag_member is None:
-            raise RuntimeError(
-                "QAPISchemaVariants has no tag_member property until "
-                "after check() has been run."
-            )
-        return self._tag_member
-
     def set_defined_in(self, name: str) -> None:
         for v in self.variants:
             v.set_defined_in(name)
 
     def check(
-        self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
+            self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
     ) -> None:
-        if self._tag_name:      # union
-            # We need to narrow the member type:
-            tmp = seen.get(c_name(self._tag_name))
-            assert tmp is None or isinstance(tmp, QAPISchemaObjectTypeMember)
-            self._tag_member = tmp
-
-            base = "'base'"
-            # Pointing to the base type when not implicit would be
-            # nice, but we don't know it here
-            if not self._tag_member or self._tag_name != self._tag_member.name:
-                raise QAPISemError(
-                    self.info,
-                    "discriminator '%s' is not a member of %s"
-                    % (self._tag_name, base))
-            # Here we do:
-            assert self.tag_member.defined_in
-            base_type = schema.lookup_type(self.tag_member.defined_in)
-            assert base_type
-            if not base_type.is_implicit():
-                base = "base type '%s'" % self.tag_member.defined_in
-            if not isinstance(self.tag_member.type, QAPISchemaEnumType):
-                raise QAPISemError(
-                    self.info,
-                    "discriminator member '%s' of %s must be of enum type"
-                    % (self._tag_name, base))
-            if self.tag_member.optional:
-                raise QAPISemError(
-                    self.info,
-                    "discriminator member '%s' of %s must not be optional"
-                    % (self._tag_name, base))
-            if self.tag_member.ifcond.is_present():
-                raise QAPISemError(
-                    self.info,
-                    "discriminator member '%s' of %s must not be conditional"
-                    % (self._tag_name, base))
-        else:                   # alternate
-            assert self._tag_member
-            assert isinstance(self.tag_member.type, QAPISchemaEnumType)
-            assert not self.tag_member.optional
-            assert not self.tag_member.ifcond.is_present()
-        if self._tag_name:      # union
-            # branches that are not explicitly covered get an empty type
-            assert self.tag_member.defined_in
-            cases = {v.name for v in self.variants}
-            for m in self.tag_member.type.members:
-                if m.name not in cases:
-                    v = QAPISchemaVariant(m.name, self.info,
-                                          'q_empty', m.ifcond)
-                    v.set_defined_in(self.tag_member.defined_in)
-                    self.variants.append(v)
+        for v in self.variants:
+            v.check(schema)
+
+
+class QAPISchemaBranches(QAPISchemaVariants):
+    def __init__(self,
+                 info: QAPISourceInfo,
+                 variants: List[QAPISchemaVariant],
+                 tag_name: str):
+        super().__init__(info, variants)
+        self._tag_name = tag_name
+
+    def check(
+            self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
+    ) -> None:
+        # We need to narrow the member type:
+        tag_member = seen.get(c_name(self._tag_name))
+        assert (tag_member is None
+                or isinstance(tag_member, QAPISchemaObjectTypeMember))
+
+        base = "'base'"
+        # Pointing to the base type when not implicit would be
+        # nice, but we don't know it here
+        if not tag_member or self._tag_name != tag_member.name:
+            raise QAPISemError(
+                self.info,
+                "discriminator '%s' is not a member of %s"
+                % (self._tag_name, base))
+        self.tag_member = tag_member
+        # Here we do:
+        assert tag_member.defined_in
+        base_type = schema.lookup_type(tag_member.defined_in)
+        assert base_type
+        if not base_type.is_implicit():
+            base = "base type '%s'" % tag_member.defined_in
+        if not isinstance(tag_member.type, QAPISchemaEnumType):
+            raise QAPISemError(
+                self.info,
+                "discriminator member '%s' of %s must be of enum type"
+                % (self._tag_name, base))
+        if tag_member.optional:
+            raise QAPISemError(
+                self.info,
+                "discriminator member '%s' of %s must not be optional"
+                % (self._tag_name, base))
+        if tag_member.ifcond.is_present():
+            raise QAPISemError(
+                self.info,
+                "discriminator member '%s' of %s must not be conditional"
+                % (self._tag_name, base))
+        # branches that are not explicitly covered get an empty type
+        assert tag_member.defined_in
+        cases = {v.name for v in self.variants}
+        for m in tag_member.type.members:
+            if m.name not in cases:
+                v = QAPISchemaVariant(m.name, self.info,
+                                      'q_empty', m.ifcond)
+                v.set_defined_in(tag_member.defined_in)
+                self.variants.append(v)
         if not self.variants:
             raise QAPISemError(self.info, "union has no branches")
         for v in self.variants:
@@ -807,11 +799,11 @@ class QAPISchemaVariants:
             # Union names must match enum values; alternate names are
             # checked separately. Use 'seen' to tell the two apart.
             if seen:
-                if v.name not in self.tag_member.type.member_names():
+                if v.name not in tag_member.type.member_names():
                     raise QAPISemError(
                         self.info,
                         "branch '%s' is not a value of %s"
-                        % (v.name, self.tag_member.type.describe()))
+                        % (v.name, tag_member.type.describe()))
                 if not isinstance(v.type, QAPISchemaObjectType):
                     raise QAPISemError(
                         self.info,
@@ -833,6 +825,23 @@ class QAPISchemaVariants:
             v.type.check_clash(info, dict(seen))
 
 
+class QAPISchemaAlternatives(QAPISchemaVariants):
+    def __init__(self,
+                 info: QAPISourceInfo,
+                 variants: List[QAPISchemaVariant],
+                 tag_member: QAPISchemaObjectTypeMember):
+        super().__init__(info, variants)
+        self.tag_member = tag_member
+
+    def check(
+            self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
+    ) -> None:
+        super().check(schema, seen)
+        assert isinstance(self.tag_member.type, QAPISchemaEnumType)
+        assert not self.tag_member.optional
+        assert not self.tag_member.ifcond.is_present()
+
+
 class QAPISchemaMember:
     """ Represents object members, enum members and features """
     role = 'member'
@@ -1019,7 +1028,7 @@ class QAPISchemaCommand(QAPISchemaDefinition):
                     "command's 'data' cannot take %s"
                     % arg_type.describe())
             self.arg_type = arg_type
-            if self.arg_type.variants and not self.boxed:
+            if self.arg_type.branches and not self.boxed:
                 raise QAPISemError(
                     self.info,
                     "command's 'data' can take %s only with 'boxed': true"
@@ -1087,7 +1096,7 @@ class QAPISchemaEvent(QAPISchemaDefinition):
                     "event's 'data' cannot take %s"
                     % typ.describe())
             self.arg_type = typ
-            if self.arg_type.variants and not self.boxed:
+            if self.arg_type.branches and not self.boxed:
                 raise QAPISemError(
                     self.info,
                     "event's 'data' can take %s only with 'boxed': true"
@@ -1388,8 +1397,8 @@ class QAPISchema:
         self._def_definition(
             QAPISchemaObjectType(name, info, expr.doc, ifcond, features,
                                  base, members,
-                                 QAPISchemaVariants(
-                                     tag_name, info, None, variants)))
+                                 QAPISchemaBranches(
+                                     info, variants, tag_name)))
 
     def _def_alternate_type(self, expr: QAPIExpression) -> None:
         name = expr['alternate']
@@ -1407,7 +1416,7 @@ class QAPISchema:
         self._def_definition(
             QAPISchemaAlternateType(
                 name, info, expr.doc, ifcond, features,
-                QAPISchemaVariants(None, info, tag_member, variants)))
+                QAPISchemaAlternatives(info, variants, tag_member)))
 
     def _def_command(self, expr: QAPIExpression) -> None:
         name = expr['command']
diff --git a/scripts/qapi/types.py b/scripts/qapi/types.py
index c39d054..0dd0b00 100644
--- a/scripts/qapi/types.py
+++ b/scripts/qapi/types.py
@@ -23,6 +23,8 @@ from .gen import (
 )
 from .schema import (
     QAPISchema,
+    QAPISchemaAlternatives,
+    QAPISchemaBranches,
     QAPISchemaEnumMember,
     QAPISchemaFeature,
     QAPISchemaIfCond,
@@ -169,7 +171,7 @@ def gen_object(name: str, ifcond: QAPISchemaIfCond,
         if not isinstance(obj, QAPISchemaObjectType):
             continue
         ret += gen_object(obj.name, obj.ifcond, obj.base,
-                          obj.local_members, obj.variants)
+                          obj.local_members, obj.branches)
 
     ret += mcgen('''
 
@@ -348,13 +350,13 @@ class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
                           features: List[QAPISchemaFeature],
                           base: Optional[QAPISchemaObjectType],
                           members: List[QAPISchemaObjectTypeMember],
-                          variants: Optional[QAPISchemaVariants]) -> None:
+                          branches: Optional[QAPISchemaBranches]) -> None:
         # Nothing to do for the special empty builtin
         if name == 'q_empty':
             return
         with ifcontext(ifcond, self._genh):
             self._genh.preamble_add(gen_fwd_object_or_array(name))
-        self._genh.add(gen_object(name, ifcond, base, members, variants))
+        self._genh.add(gen_object(name, ifcond, base, members, branches))
         with ifcontext(ifcond, self._genh, self._genc):
             if base and not base.is_implicit():
                 self._genh.add(gen_upcast(name, base))
@@ -369,11 +371,11 @@ class QAPISchemaGenTypeVisitor(QAPISchemaModularCVisitor):
                              info: Optional[QAPISourceInfo],
                              ifcond: QAPISchemaIfCond,
                              features: List[QAPISchemaFeature],
-                             variants: QAPISchemaVariants) -> None:
+                             alternatives: QAPISchemaAlternatives) -> None:
         with ifcontext(ifcond, self._genh):
             self._genh.preamble_add(gen_fwd_object_or_array(name))
         self._genh.add(gen_object(name, ifcond, None,
-                                  [variants.tag_member], variants))
+                                  [alternatives.tag_member], alternatives))
         with ifcontext(ifcond, self._genh, self._genc):
             self._gen_type_cleanup(name)
 
diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py
index a21b7b1..e766aca 100644
--- a/scripts/qapi/visit.py
+++ b/scripts/qapi/visit.py
@@ -28,6 +28,8 @@ from .gen import (
 )
 from .schema import (
     QAPISchema,
+    QAPISchemaAlternatives,
+    QAPISchemaBranches,
     QAPISchemaEnumMember,
     QAPISchemaEnumType,
     QAPISchemaFeature,
@@ -35,7 +37,6 @@ from .schema import (
     QAPISchemaObjectType,
     QAPISchemaObjectTypeMember,
     QAPISchemaType,
-    QAPISchemaVariants,
 )
 from .source import QAPISourceInfo
 
@@ -63,7 +64,7 @@ bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp);
 def gen_visit_object_members(name: str,
                              base: Optional[QAPISchemaObjectType],
                              members: List[QAPISchemaObjectTypeMember],
-                             variants: Optional[QAPISchemaVariants]) -> str:
+                             branches: Optional[QAPISchemaBranches]) -> str:
     ret = mcgen('''
 
 bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
@@ -131,8 +132,8 @@ bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
 ''')
         ret += memb.ifcond.gen_endif()
 
-    if variants:
-        tag_member = variants.tag_member
+    if branches:
+        tag_member = branches.tag_member
         assert isinstance(tag_member.type, QAPISchemaEnumType)
 
         ret += mcgen('''
@@ -140,7 +141,7 @@ bool visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
 ''',
                      c_name=c_name(tag_member.name))
 
-        for var in variants.variants:
+        for var in branches.variants:
             case_str = c_enum_const(tag_member.type.name, var.name,
                                     tag_member.type.prefix)
             ret += var.ifcond.gen_if()
@@ -222,7 +223,8 @@ bool visit_type_%(c_name)s(Visitor *v, const char *name,
                  c_name=c_name(name))
 
 
-def gen_visit_alternate(name: str, variants: QAPISchemaVariants) -> str:
+def gen_visit_alternate(name: str,
+                        alternatives: QAPISchemaAlternatives) -> str:
     ret = mcgen('''
 
 bool visit_type_%(c_name)s(Visitor *v, const char *name,
@@ -244,7 +246,7 @@ bool visit_type_%(c_name)s(Visitor *v, const char *name,
 ''',
                 c_name=c_name(name))
 
-    for var in variants.variants:
+    for var in alternatives.variants:
         ret += var.ifcond.gen_if()
         ret += mcgen('''
     case %(case)s:
@@ -393,14 +395,14 @@ class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
                           features: List[QAPISchemaFeature],
                           base: Optional[QAPISchemaObjectType],
                           members: List[QAPISchemaObjectTypeMember],
-                          variants: Optional[QAPISchemaVariants]) -> None:
+                          branches: Optional[QAPISchemaBranches]) -> None:
         # Nothing to do for the special empty builtin
         if name == 'q_empty':
             return
         with ifcontext(ifcond, self._genh, self._genc):
             self._genh.add(gen_visit_members_decl(name))
             self._genc.add(gen_visit_object_members(name, base,
-                                                    members, variants))
+                                                    members, branches))
             # TODO Worth changing the visitor signature, so we could
             # directly use rather than repeat type.is_implicit()?
             if not name.startswith('q_'):
@@ -413,10 +415,10 @@ class QAPISchemaGenVisitVisitor(QAPISchemaModularCVisitor):
                              info: Optional[QAPISourceInfo],
                              ifcond: QAPISchemaIfCond,
                              features: List[QAPISchemaFeature],
-                             variants: QAPISchemaVariants) -> None:
+                             alternatives: QAPISchemaAlternatives) -> None:
         with ifcontext(ifcond, self._genh, self._genc):
             self._genh.add(gen_visit_decl(name))
-            self._genc.add(gen_visit_alternate(name, variants))
+            self._genc.add(gen_visit_alternate(name, alternatives))
 
 
 def gen_visit(schema: QAPISchema,
diff --git a/tests/qapi-schema/test-qapi.py b/tests/qapi-schema/test-qapi.py
index 4009543..7e3f9f4 100755
--- a/tests/qapi-schema/test-qapi.py
+++ b/tests/qapi-schema/test-qapi.py
@@ -48,7 +48,7 @@ class QAPISchemaTestVisitor(QAPISchemaVisitor):
         self._print_if(ifcond)
 
     def visit_object_type(self, name, info, ifcond, features,
-                          base, members, variants):
+                          base, members, branches):
         print('object %s' % name)
         if base:
             print('    base %s' % base.name)
@@ -57,13 +57,14 @@ class QAPISchemaTestVisitor(QAPISchemaVisitor):
                   % (m.name, m.type.name, m.optional))
             self._print_if(m.ifcond, 8)
             self._print_features(m.features, indent=8)
-        self._print_variants(variants)
+        self._print_variants(branches)
         self._print_if(ifcond)
         self._print_features(features)
 
-    def visit_alternate_type(self, name, info, ifcond, features, variants):
+    def visit_alternate_type(self, name, info, ifcond, features,
+                             alternatives):
         print('alternate %s' % name)
-        self._print_variants(variants)
+        self._print_variants(alternatives)
         self._print_if(ifcond)
         self._print_features(features)