Implement [Unforgeable]

This is mostly stolen from Gecko. As there, we define the unforgeable members
on an object stored in the slots of the prototype object. They are then copied
onto instance objects when they are instantiated. It should be noted that
proxy objects see their unforgeable memebers defined on their expando object.

Unforgeable attributes aren't properly inherited in codegen (in a similar
fashion as getters and setters as filed in #5875) and require to be redefined
in derived interfaces. Fortunately, there are currently no such interfaces.

No unforgeable members can be included into the TestBinding interfaces for good
measure because they are not compatible with setters.

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

@@ -139,6 +139,13 @@ def getDescriptor(self, interfaceName):
         return self.config.getDescriptor(interfaceName)
 
 
+def MemberIsUnforgeable(member, descriptor):
+    return ((member.isAttr() or member.isMethod()) and
+            not member.isStatic() and
+            (member.isUnforgeable() or
+             bool(descriptor.interface.getExtendedAttribute("Unforgeable"))))
+
+
 class Descriptor(DescriptorProvider):
     """
     Represents a single descriptor for an interface. See Bindings.conf.
@@ -175,6 +182,9 @@ def __init__(self, config, interface, desc):
         # them as having a concrete descendant.
         self.concrete = (not self.interface.isCallback() and
                          desc.get('concrete', True))
+        self.hasUnforgeableMembers = (self.concrete and
+                                      any(MemberIsUnforgeable(m, self) for m in
+                                          self.interface.members))
 
         self.operations = {
             'IndexedGetter': None,

components/script/dom/bindings/utils.rs

@@ -93,6 +93,10 @@ impl GlobalStaticData {
 // changes.
 const DOM_PROTO_INSTANCE_CLASS_SLOT: u32 = 0;
 
+/// The index of the slot where the object holder of that interface's
+/// unforgeable members are defined.
+pub const DOM_PROTO_UNFORGEABLE_HOLDER_SLOT: u32 = 1;
+
 /// The index of the slot that contains a reference to the ProtoOrIfaceArray.
 // All DOM globals must have a slot at DOM_PROTOTYPE_SLOT.
 pub const DOM_PROTOTYPE_SLOT: u32 = js::JSCLASS_GLOBAL_SLOT_COUNT;
@@ -191,8 +195,12 @@ pub fn get_proto_or_iface_array(global: *mut JSObject) -> *mut ProtoOrIfaceArray
 pub struct NativeProperties {
     /// Instance methods for the interface.
     pub methods: Option<&'static [JSFunctionSpec]>,
+    /// Unforgeable instance methods for the interface.
+    pub unforgeable_methods: Option<&'static [JSFunctionSpec]>,
     /// Instance attributes for the interface.
     pub attrs: Option<&'static [JSPropertySpec]>,
+    /// Unforgeable instance attributes for the interface.
+    pub unforgeable_attrs: Option<&'static [JSPropertySpec]>,
     /// Constants for the interface.
     pub consts: Option<&'static [ConstantSpec]>,
     /// Static methods for the interface.
@@ -342,8 +350,8 @@ fn define_constants(cx: *mut JSContext, obj: HandleObject,
 /// Defines methods on `obj`. The last entry of `methods` must contain zeroed
 /// memory.
 /// Fails on JSAPI failure.
-fn define_methods(cx: *mut JSContext, obj: HandleObject,
-                  methods: &'static [JSFunctionSpec]) {
+pub fn define_methods(cx: *mut JSContext, obj: HandleObject,
+                      methods: &'static [JSFunctionSpec]) {
     unsafe {
         assert!(JS_DefineFunctions(cx, obj, methods.as_ptr(), PropertyDefinitionBehavior::DefineAllProperties) != 0);
     }
@@ -352,8 +360,8 @@ fn define_methods(cx: *mut JSContext, obj: HandleObject,
 /// Defines attributes on `obj`. The last entry of `properties` must contain
 /// zeroed memory.
 /// Fails on JSAPI failure.
-fn define_properties(cx: *mut JSContext, obj: HandleObject,
-                     properties: &'static [JSPropertySpec]) {
+pub fn define_properties(cx: *mut JSContext, obj: HandleObject,
+                         properties: &'static [JSPropertySpec]) {
     unsafe {
         assert!(JS_DefineProperties(cx, obj, properties.as_ptr()) != 0);
     }

components/script/dom/testbindingproxy.rs

@@ -28,5 +28,4 @@ impl TestBindingProxyMethods for TestBindingProxy {
     fn IndexedSetter(&self, _: u32, _: DOMString) -> () {}
     fn NamedSetter(&self, _: DOMString, _: DOMString) -> () {}
     fn NamedGetter(&self, _: DOMString, _: &mut bool) -> DOMString { "".to_owned() }
-
 }

components/script/dom/webidls/Document.webidl

@@ -79,7 +79,7 @@ enum DocumentReadyState { "loading", "interactive", "complete" };
 // [OverrideBuiltins]
 partial /*sealed*/ interface Document {
   // resource metadata management
-  // [PutForwards=href, Unforgeable]
+  [/*PutForwards=href, */Unforgeable]
   readonly attribute Location/*?*/ location;
   // attribute DOMString domain;
   // readonly attribute DOMString referrer;

components/script/dom/webidls/Location.webidl

@@ -4,7 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // https://html.spec.whatwg.org/multipage/#location
-/*[Unforgeable]*/ interface Location {
+[Unforgeable] interface Location {
   void assign(DOMString url);
   //void replace(DOMString url);
   void reload();

components/script/dom/webidls/Window.webidl

@@ -11,9 +11,9 @@
   //[Replaceable] readonly attribute WindowProxy self;
   readonly attribute Window window;
   [BinaryName="Self_"] readonly attribute Window self;
-  /*[Unforgeable]*/ readonly attribute Document document;
+  [Unforgeable] readonly attribute Document document;
   //         attribute DOMString name;
-  /*[PutForwards=href, Unforgeable]*/ readonly attribute Location location;
+  [/*PutForwards=href, */Unforgeable] readonly attribute Location location;
   //readonly attribute History history;
   //[Replaceable] readonly attribute BarProp locationbar;
   //[Replaceable] readonly attribute BarProp menubar;

tests/wpt/metadata/html/dom/interfaces.html.ini

@@ -7029,9 +7029,6 @@
   [Window interface: window must inherit property "self" with the proper type (1)]
     expected: FAIL
 
-  [Window interface: window must have own property "document"]
-    expected: FAIL
-
   [Window interface: window must inherit property "name" with the proper type (3)]
     expected: FAIL
 
@@ -8667,18 +8664,9 @@
   [Window interface: window must inherit property "localStorage" with the proper type (124)]
     expected: FAIL
 
-  [Location interface: window.location must have own property "assign"]
-    expected: FAIL
-
-  [Location interface: calling assign(DOMString) on window.location with too few arguments must throw TypeError]
-    expected: FAIL
-
   [Location interface: window.location must have own property "replace"]
     expected: FAIL
 
-  [Location interface: window.location must have own property "reload"]
-    expected: FAIL
-
   [HTMLOptionElement must be primary interface of new Option()]
     expected: FAIL