1 files changed, 21 insertions, 14 deletions
diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index 7c6b2fe3718..4ea45ef9ded 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1984,15 +1984,15 @@ def DOMClassTypeId(desc):
     inner = ""
     if desc.hasDescendants():
         if desc.interface.getExtendedAttribute("Abstract"):
-            return "::dom::bindings::codegen::InheritTypes::TopTypeId::Abstract"
+            return "::dom::bindings::codegen::InheritTypes::TopTypeId { abstract_: () }"
         name = desc.interface.identifier.name
         inner = "(::dom::bindings::codegen::InheritTypes::%sTypeId::%s)" % (name, name)
     elif len(protochain) == 1:
-        return "::dom::bindings::codegen::InheritTypes::TopTypeId::Alone"
+        return "::dom::bindings::codegen::InheritTypes::TopTypeId { alone: () }"
     reversed_protochain = list(reversed(protochain))
     for (child, parent) in zip(reversed_protochain, reversed_protochain[1:]):
         inner = "(::dom::bindings::codegen::InheritTypes::%sTypeId::%s%s)" % (parent, child, inner)
-    return "::dom::bindings::codegen::InheritTypes::TopTypeId::%s%s" % (protochain[0], inner)
+    return "::dom::bindings::codegen::InheritTypes::TopTypeId { %s: %s }" % (protochain[0].lower(), inner)
 
 
 def DOMClass(descriptor):
@@ -6931,18 +6931,26 @@ class GlobalGenRoots():
 
         typeIdCode = []
         topTypeVariants = [
-            ("ID used by abstract interfaces.", "Abstract"),
-            ("ID used by interfaces that are not castable.", "Alone"),
+            ("ID used by abstract interfaces.", "pub abstract_: ()"),
+            ("ID used by interfaces that are not castable.", "pub alone: ()"),
         ]
         topTypeVariants += [
-            ("ID used by interfaces that derive from %s." % typeName, "%s(%sTypeId)" % (typeName, typeName))
+            ("ID used by interfaces that derive from %s." % typeName,
+             "pub %s: %sTypeId" % (typeName.lower(), typeName))
             for typeName in topTypes
         ]
         topTypeVariantsAsStrings = [CGGeneric("/// %s\n%s," % variant) for variant in topTypeVariants]
         typeIdCode.append(CGWrapper(CGIndenter(CGList(topTypeVariantsAsStrings, "\n"), 4),
-                                    pre="#[derive(Clone, Copy, Debug)]\npub enum TopTypeId {\n",
+                                    pre="#[derive(Copy)]\npub union TopTypeId {\n",
                                     post="\n}\n\n"))
 
+        typeIdCode.append(CGGeneric("""\
+impl Clone for TopTypeId {
+    fn clone(&self) -> Self { *self }
+}
+
+"""))
+
         def type_id_variant(name):
             # If `name` is present in the hierarchy keys', that means some other interfaces
             # derive from it and this enum variant should have an argument with its own
@@ -6962,17 +6970,16 @@ class GlobalGenRoots():
                 typeIdCode.append(CGGeneric("""\
 impl %(base)s {
     pub fn type_id(&self) -> &'static %(base)sTypeId {
-        let domclass = unsafe {
-            get_dom_class(self.reflector().get_jsobject().get()).unwrap()
-        };
-        match domclass.type_id {
-            TopTypeId::%(base)s(ref type_id) => type_id,
-            _ => unreachable!(),
+        unsafe {
+            &get_dom_class(self.reflector().get_jsobject().get())
+                .unwrap()
+                .type_id
+                .%(field)s
         }
     }
 }
 
-""" % {'base': base}))
+""" % {'base': base, 'field': base.lower()}))
 
         curr = CGList(imports + typeIdCode + allprotos)
         curr = CGWrapper(curr, pre=AUTOGENERATED_WARNING_COMMENT)