Introduce [Abstract] to mark non-leaf interfaces

Some interfaces like Node, CharacterData and HTMLTableCellElement are never
instantiated directly, only their descendant interfaces are. Those are marked
with [Abstract] to set their type_id to None instead of having dummy values
in the TypeId enums.

components/layout/construct.rs

@@ -1430,8 +1430,6 @@ impl<'a> PostorderNodeMutTraversal for FlowConstructor<'a> {
             Some(NodeTypeId::Document) => {
                 (display::T::none, float::T::none, position::T::static_)
             }
-            Some(NodeTypeId::Node) => unreachable!(),
-            Some(NodeTypeId::CharacterData(CharacterDataTypeId::CharacterData)) => unreachable!(),
         };
 
         debug!("building flow for node: {:?} {:?} {:?} {:?}", display, float, positioning, node.type_id());
@@ -1587,7 +1585,6 @@ impl<'ln> NodeUtils for ThreadSafeLayoutNode<'ln> {
             Some(NodeTypeId::Element(ElementTypeId::HTMLElement(
                         HTMLElementTypeId::HTMLObjectElement))) => self.has_object_data(),
             Some(NodeTypeId::Element(_)) => false,
-            Some(NodeTypeId::Node) => unreachable!(),
         }
     }
 

components/script/dom/bindings/codegen/CodegenRust.py

@@ -1724,7 +1724,7 @@ class CGNamespace(CGWrapper):
 
 def EventTargetEnum(desc):
     protochain = desc.prototypeChain
-    if protochain[0] != "EventTarget":
+    if protochain[0] != "EventTarget" or desc.interface.getExtendedAttribute("Abstract"):
         return "None"
 
     inner = ""

components/script/dom/bindings/codegen/parser/WebIDL.py

@@ -1357,7 +1357,8 @@ class IDLInterface(IDLObjectWithScope, IDLExposureMixins):
                   identifier == "ChromeOnly" or
                   identifier == "Unforgeable" or
                   identifier == "UnsafeInPrerendering" or
-                  identifier == "LegacyEventInit"):
+                  identifier == "LegacyEventInit" or
+                  identifier == "Abstract"):
                 # Known extended attributes that do not take values
                 if not attr.noArguments():
                     raise WebIDLError("[%s] must take no arguments" % identifier,

components/script/dom/bindings/codegen/parser/abstract.patch

@@ -0,0 +1,12 @@
+--- WebIDL.py
++++ WebIDL.py
+@@ -1357,7 +1357,8 @@ class IDLInterface(IDLObjectWithScope, IDLExposureMixins):
+                   identifier == "ChromeOnly" or
+                   identifier == "Unforgeable" or
+                   identifier == "UnsafeInPrerendering" or
+-                  identifier == "LegacyEventInit"):
++                  identifier == "LegacyEventInit" or
++                  identifier == "Abstract"):
+                 # Known extended attributes that do not take values
+                 if not attr.noArguments():
+                     raise WebIDLError("[%s] must take no arguments" % identifier,

components/script/dom/bindings/codegen/parser/update.sh

@@ -1,3 +1,4 @@
 wget https://mxr.mozilla.org/mozilla-central/source/dom/bindings/parser/WebIDL.py?raw=1 -O WebIDL.py
 patch < external.patch
 patch < module.patch
+patch < abstract.patch

components/script/dom/characterdata.rs

@@ -160,8 +160,6 @@ impl CharacterDataMethods for CharacterData {
 /// The different types of CharacterData.
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum CharacterDataTypeId {
-    CharacterData,
-
     Comment,
     Text,
     ProcessingInstruction,

components/script/dom/eventtarget.rs

@@ -48,8 +48,6 @@ pub enum ListenerPhase {
 
 #[derive(Copy, Clone)]
 pub enum EventTargetTypeId {
-    EventTarget,
-
     Node(NodeTypeId),
     WebSocket,
     Window,

components/script/dom/htmlmediaelement.rs

@@ -43,8 +43,6 @@ impl HTMLMediaElement {
 
 #[derive(Copy, Clone, Debug)]
 pub enum HTMLMediaElementTypeId {
-    HTMLMediaElement = -1,
-
     HTMLAudioElement = 0,
     HTMLVideoElement = 1,
 }

components/script/dom/htmltablecellelement.rs

@@ -24,8 +24,6 @@ const DEFAULT_COLSPAN: u32 = 1;
 
 #[derive(Copy, Clone, Debug)]
 pub enum HTMLTableCellElementTypeId {
-    HTMLTableCellElement = -1,
-
     HTMLTableDataCellElement = 0,
     HTMLTableHeaderCellElement = 1,
 }

components/script/dom/node.rs

@@ -283,8 +283,6 @@ impl LayoutDataRef {
 /// The different types of nodes.
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum NodeTypeId {
-    Node,
-
     CharacterData(CharacterDataTypeId),
     DocumentType,
     DocumentFragment,
@@ -1456,8 +1454,6 @@ impl Node {
 
         // Step 4-5.
         match node.type_id() {
-            NodeTypeId::Node => unreachable!(),
-            NodeTypeId::CharacterData(CharacterDataTypeId::CharacterData) => unreachable!(),
             NodeTypeId::CharacterData(CharacterDataTypeId::Text) => {
                 if parent.is_document() {
                     return Err(HierarchyRequest);
@@ -1540,7 +1536,7 @@ impl Node {
                     }
                 },
                 NodeTypeId::CharacterData(_) => (),
-                NodeTypeId::Document | NodeTypeId::Node => unreachable!(),
+                NodeTypeId::Document => unreachable!(),
             }
         }
         Ok(())
@@ -1700,8 +1696,6 @@ impl Node {
         // Step 2.
         // XXXabinader: clone() for each node as trait?
         let copy: Root<Node> = match node.type_id() {
-            NodeTypeId::Node => unreachable!(),
-            NodeTypeId::CharacterData(CharacterDataTypeId::CharacterData) => unreachable!(),
             NodeTypeId::DocumentType => {
                 let doctype: &DocumentType = DocumentTypeCast::to_ref(node).unwrap();
                 let doctype = DocumentType::new(doctype.name().clone(),
@@ -1894,8 +1888,6 @@ impl NodeMethods for Node {
     // https://dom.spec.whatwg.org/#dom-node-nodetype
     fn NodeType(&self) -> u16 {
         match self.type_id() {
-            NodeTypeId::Node => unreachable!(),
-            NodeTypeId::CharacterData(CharacterDataTypeId::CharacterData) => unreachable!(),
             NodeTypeId::CharacterData(CharacterDataTypeId::Text) =>
                 NodeConstants::TEXT_NODE,
             NodeTypeId::CharacterData(CharacterDataTypeId::ProcessingInstruction) =>
@@ -1916,12 +1908,10 @@ impl NodeMethods for Node {
     // https://dom.spec.whatwg.org/#dom-node-nodename
     fn NodeName(&self) -> DOMString {
         match self.type_id() {
-            NodeTypeId::Node => unreachable!(),
             NodeTypeId::Element(..) => {
                 let elem: &Element = ElementCast::to_ref(self).unwrap();
                 elem.TagName()
             }
-            NodeTypeId::CharacterData(CharacterDataTypeId::CharacterData) => unreachable!(),
             NodeTypeId::CharacterData(CharacterDataTypeId::Text) => "#text".to_owned(),
             NodeTypeId::CharacterData(CharacterDataTypeId::ProcessingInstruction) => {
                 let processing_instruction: &ProcessingInstruction =
@@ -1946,7 +1936,6 @@ impl NodeMethods for Node {
     // https://dom.spec.whatwg.org/#dom-node-ownerdocument
     fn GetOwnerDocument(&self) -> Option<Root<Document>> {
         match self.type_id() {
-            NodeTypeId::Node => unreachable!(),
             NodeTypeId::CharacterData(..) |
             NodeTypeId::Element(..) |
             NodeTypeId::DocumentType |
@@ -2025,7 +2014,6 @@ impl NodeMethods for Node {
     // https://dom.spec.whatwg.org/#dom-node-textcontent
     fn GetTextContent(&self) -> Option<DOMString> {
         match self.type_id() {
-            NodeTypeId::Node => unreachable!(),
             NodeTypeId::DocumentFragment |
             NodeTypeId::Element(..) => {
                 let content = Node::collect_text_contents(self.traverse_preorder());
@@ -2046,7 +2034,6 @@ impl NodeMethods for Node {
     fn SetTextContent(&self, value: Option<DOMString>) {
         let value = value.unwrap_or(String::new());
         match self.type_id() {
-            NodeTypeId::Node => unreachable!(),
             NodeTypeId::DocumentFragment |
             NodeTypeId::Element(..) => {
                 // Step 1-2.
@@ -2106,7 +2093,6 @@ impl NodeMethods for Node {
 
         // Step 4-5.
         match node.type_id() {
-            NodeTypeId::Node => unreachable!(),
             NodeTypeId::CharacterData(CharacterDataTypeId::Text) if self.is_document() =>
                 return Err(HierarchyRequest),
             NodeTypeId::DocumentType if !self.is_document() => return Err(HierarchyRequest),
@@ -2170,7 +2156,7 @@ impl NodeMethods for Node {
                     }
                 },
                 NodeTypeId::CharacterData(..) => (),
-                NodeTypeId::Document | NodeTypeId::Node => unreachable!()
+                NodeTypeId::Document => unreachable!(),
             }
         }
 

components/script/dom/webidls/CharacterData.webidl

@@ -10,6 +10,7 @@
  * liability, trademark and document use rules apply.
  */
 
+[Abstract]
 interface CharacterData : Node {
   [TreatNullAs=EmptyString] attribute DOMString data;
   readonly attribute unsigned long length;

components/script/dom/webidls/EventTarget.webidl

@@ -6,6 +6,7 @@
  * https://dom.spec.whatwg.org/#interface-eventtarget
  */
 
+[Abstract]
 interface EventTarget {
   void addEventListener(DOMString type,
                         EventListener? listener,

components/script/dom/webidls/HTMLMediaElement.webidl

@@ -5,6 +5,7 @@
 
 // https://www.whatwg.org/html/#htmlmediaelement
 //enum CanPlayTypeResult { "" /* empty string */, "maybe", "probably" };
+[Abstract]
 interface HTMLMediaElement : HTMLElement {
 
   // error state

components/script/dom/webidls/HTMLTableCellElement.webidl

@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // https://www.whatwg.org/html/#htmltablecellelement
+[Abstract]
 interface HTMLTableCellElement : HTMLElement {
              attribute unsigned long colSpan;
   //         attribute unsigned long rowSpan;

components/script/dom/webidls/Node.webidl

@@ -7,6 +7,7 @@
  * https://dom.spec.whatwg.org/#interface-node
  */
 
+[Abstract]
 interface Node : EventTarget {
   const unsigned short ELEMENT_NODE = 1;
   const unsigned short ATTRIBUTE_NODE = 2; // historical

components/script/dom/webidls/WorkerGlobalScope.webidl

@@ -2,8 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// https://www.whatwg.org/html/#workerglobalscope
+// https://html.spec.whatwg.org/multipage/#workerglobalscope
-//[Exposed=Worker]
+[Abstract/*, Exposed=Worker*/]
 interface WorkerGlobalScope : EventTarget {
   [BinaryName="Self_"] readonly attribute WorkerGlobalScope self;
   readonly attribute WorkerLocation location;

components/script/dom/webidls/XMLHttpRequestEventTarget.webidl

@@ -13,7 +13,7 @@
  * http://www.openwebfoundation.org/legal/the-owf-1-0-agreements/owfa-1-0.
  */
 
-//[Exposed=(Window,Worker)]
+[Abstract/*, Exposed=(Window,Worker)*/]
 interface XMLHttpRequestEventTarget : EventTarget {
   // event handlers
   attribute EventHandler onloadstart;

components/script/dom/workerglobalscope.rs

@@ -38,8 +38,6 @@ use std::sync::mpsc::Receiver;
 
 #[derive(Copy, Clone, PartialEq)]
 pub enum WorkerGlobalScopeTypeId {
-    WorkerGlobalScope,
-
     DedicatedWorkerGlobalScope,
 }
 

components/script/dom/xmlhttprequesteventtarget.rs

@@ -10,8 +10,6 @@ use dom::eventtarget::{EventTarget, EventTargetTypeId};
 
 #[derive(Copy, Clone, PartialEq)]
 pub enum XMLHttpRequestEventTargetTypeId {
-    XMLHttpRequestEventTarget,
-
     XMLHttpRequest,
     XMLHttpRequestUpload,
 }

components/script/mem.rs

@@ -9,9 +9,7 @@ use dom::element::ElementTypeId;
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
 use dom::htmlelement::HTMLElementTypeId;
 use dom::htmlmediaelement::HTMLMediaElementTypeId::HTMLAudioElement;
-use dom::htmlmediaelement::HTMLMediaElementTypeId::HTMLMediaElement;
 use dom::htmlmediaelement::HTMLMediaElementTypeId::HTMLVideoElement;
-use dom::htmltablecellelement::HTMLTableCellElementTypeId::HTMLTableCellElement;
 use dom::htmltablecellelement::HTMLTableCellElementTypeId::HTMLTableDataCellElement;
 use dom::htmltablecellelement::HTMLTableCellElementTypeId::HTMLTableHeaderCellElement;
 use dom::node::NodeTypeId;
@@ -249,13 +247,5 @@ pub fn heap_size_of_eventtarget(target: &EventTarget) -> usize {
             heap_size_of_self_and_children(DocumentTypeCast::to_ref(target).unwrap()),
         &EventTargetTypeId::Node(NodeTypeId::DocumentFragment) =>
             heap_size_of_self_and_children(DocumentFragmentCast::to_ref(target).unwrap()),
-        &EventTargetTypeId::EventTarget |
-        &EventTargetTypeId::Node(NodeTypeId::Node) |
-        &EventTargetTypeId::Node(NodeTypeId::Element(ElementTypeId::HTMLElement(
-                HTMLElementTypeId::HTMLMediaElement(HTMLMediaElement)))) |
-        &EventTargetTypeId::Node(NodeTypeId::Element(ElementTypeId::HTMLElement(
-                HTMLElementTypeId::HTMLTableCellElement(HTMLTableCellElement)))) => {
-            unreachable!()
-        },
     }
 }

components/script/parse/html.rs

@@ -184,8 +184,6 @@ impl<'a> Serializable for &'a Node {
                                  traversal_scope: TraversalScope) -> io::Result<()> {
         let node = *self;
         match (traversal_scope, node.type_id()) {
-            (_, NodeTypeId::Node) => unreachable!(),
-            (_, NodeTypeId::CharacterData(CharacterDataTypeId::CharacterData)) => unreachable!(),
             (_, NodeTypeId::Element(..)) => {
                 let elem = ElementCast::to_ref(node).unwrap();
                 let name = QualName::new(elem.namespace().clone(),