Upgrade to Spidermonkey 67.

Cargo.lock

@@ -2827,21 +2827,21 @@ dependencies = [
 
 [[package]]
 name = "mozjs"
-version = "0.11.0"
+version = "0.12.0"
-source = "git+https://github.com/servo/rust-mozjs#bea7b5cca9448ca10f8f710b7ad75567424f73b4"
+source = "git+https://github.com/servo/rust-mozjs#124e5243a02ddaa879f2988313cee738c435f8b1"
 dependencies = [
  "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.53 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mozjs_sys 0.66.1 (git+https://github.com/servo/mozjs?rev=05c7d307811f88ca263f1861ccca0a81ffb0b58d)",
+ "mozjs_sys 0.67.0 (git+https://github.com/servo/mozjs?rev=b2f83932fe9d361face14efd03f2465b9262e687)",
  "num-traits 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "mozjs_sys"
-version = "0.66.1"
+version = "0.67.0"
-source = "git+https://github.com/servo/mozjs?rev=05c7d307811f88ca263f1861ccca0a81ffb0b58d#05c7d307811f88ca263f1861ccca0a81ffb0b58d"
+source = "git+https://github.com/servo/mozjs?rev=b2f83932fe9d361face14efd03f2465b9262e687#b2f83932fe9d361face14efd03f2465b9262e687"
 dependencies = [
  "bindgen 0.49.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3755,7 +3755,7 @@ dependencies = [
  "mime_guess 2.0.0-alpha.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "mitochondria 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "mozangle 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "mozjs 0.11.0 (git+https://github.com/servo/rust-mozjs)",
+ "mozjs 0.12.0 (git+https://github.com/servo/rust-mozjs)",
  "msg 0.0.1",
  "net_traits 0.0.1",
  "num-traits 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5771,8 +5771,8 @@ dependencies = [
 "checksum miow 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "396aa0f2003d7df8395cb93e09871561ccc3e785f0acb369170e8cc74ddf9226"
 "checksum mitochondria 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9de3eca27871df31c33b807f834b94ef7d000956f57aa25c5aed9c5f0aae8f6f"
 "checksum mozangle 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1dc10080cc8b83bfb5580de720f00c768ec1b365c75fbc4c57324118a38a618d"
-"checksum mozjs 0.11.0 (git+https://github.com/servo/rust-mozjs)" = "<none>"
+"checksum mozjs 0.12.0 (git+https://github.com/servo/rust-mozjs)" = "<none>"
-"checksum mozjs_sys 0.66.1 (git+https://github.com/servo/mozjs?rev=05c7d307811f88ca263f1861ccca0a81ffb0b58d)" = "<none>"
+"checksum mozjs_sys 0.67.0 (git+https://github.com/servo/mozjs?rev=b2f83932fe9d361face14efd03f2465b9262e687)" = "<none>"
 "checksum msdos_time 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "aad9dfe950c057b1bfe9c1f2aa51583a8468ef2a5baba2ebbe06d775efeb7729"
 "checksum muldiv 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "451a9a05d2a32c566c897835e0ea95cf79ed2fdfe957924045a1721a36c9980f"
 "checksum net2 0.2.33 (registry+https://github.com/rust-lang/crates.io-index)" = "42550d9fb7b6684a6d404d9fa7250c2eb2646df731d1c06afc06dcee9e1bcf88"

components/script/dom/audiobuffer.rs

@@ -15,7 +15,7 @@ use crate::dom::window::Window;
 use dom_struct::dom_struct;
 use js::jsapi::JS_GetArrayBufferViewBuffer;
 use js::jsapi::{Heap, JSAutoRealm, JSContext, JSObject};
-use js::rust::wrappers::JS_DetachArrayBuffer;
+use js::rust::wrappers::DetachArrayBuffer;
 use js::rust::CustomAutoRooterGuard;
 use js::typedarray::{CreateWith, Float32Array};
 use servo_media::audio::buffer_source_node::AudioBuffer as ServoMediaAudioBuffer;
@@ -180,7 +180,7 @@ impl AudioBuffer {
                         JS_GetArrayBufferViewBuffer(cx, channel.handle(), &mut is_shared));
                     // This buffer is always created unshared
                     debug_assert!(!is_shared);
-                    let _ = JS_DetachArrayBuffer(cx, view_buffer.handle());
+                    let _ = DetachArrayBuffer(cx, view_buffer.handle());
                     data
                 } else {
                     return None;

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

@@ -466,7 +466,7 @@ class CGMethodCall(CGThing):
 
             # Check for vanilla JS objects
             # XXXbz Do we need to worry about security wrappers?
-            pickFirstSignature("%s.get().is_object() && !is_platform_object(%s.get().to_object())" %
+            pickFirstSignature("%s.get().is_object() && !is_platform_object(%s.get().to_object(), cx)" %
                                (distinguishingArg, distinguishingArg),
                                lambda s: (s[1][distinguishingIndex].type.isCallback() or
                                           s[1][distinguishingIndex].type.isCallbackInterface() or
@@ -798,7 +798,7 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
             { // Scope for our JSAutoRealm.
 
                 rooted!(in(cx) let globalObj = CurrentGlobalOrNull(cx));
-                let promiseGlobal = GlobalScope::from_object_maybe_wrapped(globalObj.handle().get());
+                let promiseGlobal = GlobalScope::from_object_maybe_wrapped(globalObj.handle().get(), cx);
 
                 rooted!(in(cx) let mut valueToResolve = $${val}.get());
                 if !JS_WrapValue(cx, valueToResolve.handle_mut()) {
@@ -866,7 +866,7 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
 
         templateBody = fill(
             """
-            match ${function}($${val}) {
+            match ${function}($${val}, cx) {
                 Ok(val) => val,
                 Err(()) => {
                     $*{failureCode}
@@ -2158,8 +2158,8 @@ class CGDOMJSClass(CGThing):
 static CLASS_OPS: js::jsapi::JSClassOps = js::jsapi::JSClassOps {
     addProperty: None,
     delProperty: None,
-    enumerate: %(enumerateHook)s,
+    enumerate: None,
-    newEnumerate: None,
+    newEnumerate: %(enumerateHook)s,
     resolve: %(resolveHook)s,
     mayResolve: None,
     finalize: Some(%(finalizeHook)s),
@@ -3223,7 +3223,6 @@ let traps = ProxyTraps {
     set: None,
     call: None,
     construct: None,
-    getPropertyDescriptor: Some(get_property_descriptor),
     hasOwn: Some(hasOwn),
     getOwnEnumerablePropertyKeys: Some(%(getOwnEnumerablePropertyKeys)s),
     nativeCall: None,
@@ -4980,10 +4979,6 @@ class CGProxyUnwrap(CGAbstractMethod):
 
     def definition_body(self):
         return CGGeneric("""\
-/*if (xpc::WrapperFactory::IsXrayWrapper(obj)) {
-    obj = js::UnwrapObject(obj);
-}*/
-//MOZ_ASSERT(IsProxy(obj));
         let mut slot = UndefinedValue();
         GetProxyReservedSlot(obj.get(), 0, &mut slot);
         let box_ = slot.to_private() as *const %s;
@@ -5430,7 +5425,7 @@ class CGAbstractClassHook(CGAbstractExternMethod):
 
     def definition_body_prologue(self):
         return CGGeneric("""
-let this = native_from_object::<%s>(obj).unwrap();
+let this = native_from_object_static::<%s>(obj).unwrap();
 """ % self.descriptor.concreteType)
 
     def definition_body(self):
@@ -5530,7 +5525,7 @@ let global = DomRoot::downcast::<dom::types::%s>(global).unwrap();
 
 // The new_target might be a cross-compartment wrapper. Get the underlying object
 // so we can do the spec's object-identity checks.
-rooted!(in(cx) let new_target = UnwrapObject(args.new_target().to_object(), 1));
+rooted!(in(cx) let new_target = UnwrapObjectDynamic(args.new_target().to_object(), cx, 1));
 if new_target.is_null() {
     throw_dom_exception(cx, global.upcast::<GlobalScope>(), Error::Type("new.target is null".to_owned()));
     return false;
@@ -5877,7 +5872,7 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         'js::glue::RUST_JSID_IS_STRING',
         'js::glue::RUST_SYMBOL_TO_JSID',
         'js::glue::int_to_jsid',
-        'js::glue::UnwrapObject',
+        'js::glue::UnwrapObjectDynamic',
         'js::panic::maybe_resume_unwind',
         'js::panic::wrap_panic',
         'js::rust::GCMethods',
@@ -5959,6 +5954,7 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         'crate::dom::bindings::conversions::is_array_like',
         'crate::dom::bindings::conversions::native_from_handlevalue',
         'crate::dom::bindings::conversions::native_from_object',
+        'crate::dom::bindings::conversions::native_from_object_static',
         'crate::dom::bindings::conversions::private_from_object',
         'crate::dom::bindings::conversions::root_from_handleobject',
         'crate::dom::bindings::conversions::root_from_handlevalue',
@@ -5979,7 +5975,6 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
         'crate::dom::bindings::proxyhandler::ensure_expando_object',
         'crate::dom::bindings::proxyhandler::fill_property_descriptor',
         'crate::dom::bindings::proxyhandler::get_expando_object',
-        'crate::dom::bindings::proxyhandler::get_property_descriptor',
         'crate::dom::bindings::mozmap::MozMap',
         'std::ptr::NonNull',
         'crate::dom::bindings::num::Finite',

components/script/dom/bindings/conversions.rs

@@ -46,7 +46,7 @@ pub use js::conversions::{ConversionResult, FromJSValConvertible, ToJSValConvert
 use js::error::throw_type_error;
 use js::glue::GetProxyReservedSlot;
 use js::glue::JS_GetReservedSlot;
-use js::glue::{IsWrapper, UnwrapObject};
+use js::glue::{IsWrapper, UnwrapObjectDynamic};
 use js::glue::{RUST_JSID_IS_INT, RUST_JSID_TO_INT};
 use js::glue::{RUST_JSID_IS_STRING, RUST_JSID_TO_STRING};
 use js::jsapi::{Heap, JSContext, JSObject, JSString};
@@ -113,11 +113,11 @@ impl<T: DomObject + IDLInterface> FromJSValConvertible for DomRoot<T> {
     type Config = ();
 
     unsafe fn from_jsval(
-        _cx: *mut JSContext,
+        cx: *mut JSContext,
         value: HandleValue,
         _config: Self::Config,
     ) -> Result<ConversionResult<DomRoot<T>>, ()> {
-        Ok(match root_from_handlevalue(value) {
+        Ok(match root_from_handlevalue(value, cx) {
             Ok(result) => ConversionResult::Success(result),
             Err(()) => ConversionResult::Failure("value is not an object".into()),
         })
@@ -411,6 +411,7 @@ pub unsafe fn get_dom_class(obj: *mut JSObject) -> Result<&'static DOMClass, ()>
 #[inline]
 pub unsafe fn private_from_proto_check<F>(
     mut obj: *mut JSObject,
+    cx: *mut JSContext,
     proto_check: F,
 ) -> Result<*const libc::c_void, ()>
 where
@@ -419,7 +420,7 @@ where
     let dom_class = get_dom_class(obj).or_else(|_| {
         if IsWrapper(obj) {
             trace!("found wrapper");
-            obj = UnwrapObject(obj, /* stopAtWindowProxy = */ 0);
+            obj = UnwrapObjectDynamic(obj, cx, /* stopAtWindowProxy = */ 0);
             if obj.is_null() {
                 trace!("unwrapping security wrapper failed");
                 Err(())
@@ -443,12 +444,44 @@ where
     }
 }
 
+/// Get a `*const libc::c_void` for the given DOM object, unless it is a DOM
+/// wrapper, and checking if the object is of the correct type.
+///
+/// Returns Err(()) if `obj` is a wrapper or if the object is not an object
+/// for a DOM object of the given type (as defined by the proto_id and proto_depth).
+#[inline]
+pub unsafe fn private_from_proto_check_static<F>(
+    obj: *mut JSObject,
+    proto_check: F,
+) -> Result<*const libc::c_void, ()>
+where
+    F: Fn(&'static DOMClass) -> bool,
+{
+    let dom_class = get_dom_class(obj).map_err(|_| ())?;
+    if proto_check(dom_class) {
+        trace!("good prototype");
+        Ok(private_from_object(obj))
+    } else {
+        trace!("bad prototype");
+        Err(())
+    }
+}
+
 /// Get a `*const T` for a DOM object accessible from a `JSObject`.
-pub fn native_from_object<T>(obj: *mut JSObject) -> Result<*const T, ()>
+pub fn native_from_object<T>(obj: *mut JSObject, cx: *mut JSContext) -> Result<*const T, ()>
 where
     T: DomObject + IDLInterface,
 {
-    unsafe { private_from_proto_check(obj, T::derives).map(|ptr| ptr as *const T) }
+    unsafe { private_from_proto_check(obj, cx, T::derives).map(|ptr| ptr as *const T) }
+}
+
+/// Get a `*const T` for a DOM object accessible from a `JSObject`, where the DOM object
+/// is guaranteed not to be a wrapper.
+pub fn native_from_object_static<T>(obj: *mut JSObject) -> Result<*const T, ()>
+where
+    T: DomObject + IDLInterface,
+{
+    unsafe { private_from_proto_check_static(obj, T::derives).map(|ptr| ptr as *const T) }
 }
 
 /// Get a `DomRoot<T>` for the given DOM object, unwrapping any wrapper
@@ -457,43 +490,56 @@ where
 /// Returns Err(()) if `obj` is an opaque security wrapper or if the object is
 /// not a reflector for a DOM object of the given type (as defined by the
 /// proto_id and proto_depth).
-pub fn root_from_object<T>(obj: *mut JSObject) -> Result<DomRoot<T>, ()>
+pub fn root_from_object<T>(obj: *mut JSObject, cx: *mut JSContext) -> Result<DomRoot<T>, ()>
 where
     T: DomObject + IDLInterface,
 {
-    native_from_object(obj).map(|ptr| unsafe { DomRoot::from_ref(&*ptr) })
+    native_from_object(obj, cx).map(|ptr| unsafe { DomRoot::from_ref(&*ptr) })
+}
+
+/// Get a `DomRoot<T>` for the given DOM object, unwrapping any wrapper
+/// around it first, and checking if the object is of the correct type.
+///
+/// Returns Err(()) if `obj` is an opaque security wrapper or if the object is
+/// not a reflector for a DOM object of the given type (as defined by the
+/// proto_id and proto_depth).
+pub fn root_from_object_static<T>(obj: *mut JSObject) -> Result<DomRoot<T>, ()>
+where
+    T: DomObject + IDLInterface,
+{
+    native_from_object_static(obj).map(|ptr| unsafe { DomRoot::from_ref(&*ptr) })
 }
 
 /// Get a `*const T` for a DOM object accessible from a `HandleValue`.
 /// Caller is responsible for throwing a JS exception if needed in case of error.
-pub fn native_from_handlevalue<T>(v: HandleValue) -> Result<*const T, ()>
+pub fn native_from_handlevalue<T>(v: HandleValue, cx: *mut JSContext) -> Result<*const T, ()>
 where
     T: DomObject + IDLInterface,
 {
     if !v.get().is_object() {
         return Err(());
     }
-    native_from_object(v.get().to_object())
+    native_from_object(v.get().to_object(), cx)
 }
 
 /// Get a `DomRoot<T>` for a DOM object accessible from a `HandleValue`.
 /// Caller is responsible for throwing a JS exception if needed in case of error.
-pub fn root_from_handlevalue<T>(v: HandleValue) -> Result<DomRoot<T>, ()>
+pub fn root_from_handlevalue<T>(v: HandleValue, cx: *mut JSContext) -> Result<DomRoot<T>, ()>
 where
     T: DomObject + IDLInterface,
 {
     if !v.get().is_object() {
         return Err(());
     }
-    root_from_object(v.get().to_object())
+    root_from_object(v.get().to_object(), cx)
 }
 
 /// Get a `DomRoot<T>` for a DOM object accessible from a `HandleObject`.
-pub fn root_from_handleobject<T>(obj: HandleObject) -> Result<DomRoot<T>, ()>
+pub fn root_from_handleobject<T>(obj: HandleObject, cx: *mut JSContext) -> Result<DomRoot<T>, ()>
 where
     T: DomObject + IDLInterface,
 {
-    root_from_object(obj.get())
+    root_from_object(obj.get(), cx)
 }
 
 impl<T: DomObject> ToJSValConvertible for DomRoot<T> {

components/script/dom/bindings/error.rs

@@ -207,8 +207,8 @@ impl ErrorInfo {
         })
     }
 
-    fn from_dom_exception(object: HandleObject) -> Option<ErrorInfo> {
+    fn from_dom_exception(object: HandleObject, cx: *mut JSContext) -> Option<ErrorInfo> {
-        let exception = match root_from_object::<DOMException>(object.get()) {
+        let exception = match root_from_object::<DOMException>(object.get(), cx) {
             Ok(exception) => exception,
             Err(_) => return None,
         };
@@ -242,7 +242,7 @@ pub unsafe fn report_pending_exception(cx: *mut JSContext, dispatch_event: bool)
     let error_info = if value.is_object() {
         rooted!(in(cx) let object = value.to_object());
         ErrorInfo::from_native_error(cx, object.handle())
-            .or_else(|| ErrorInfo::from_dom_exception(object.handle()))
+            .or_else(|| ErrorInfo::from_dom_exception(object.handle(), cx))
             .unwrap_or_else(|| ErrorInfo {
                 message: format!("uncaught exception: unknown (can't convert to string)"),
                 filename: String::new(),

components/script/dom/bindings/htmlconstructor.rs

@@ -79,7 +79,7 @@ use crate::dom::window::Window;
 use crate::script_thread::ScriptThread;
 use html5ever::interface::QualName;
 use html5ever::LocalName;
-use js::glue::UnwrapObject;
+use js::glue::UnwrapObjectStatic;
 use js::jsapi::{CallArgs, CurrentGlobalOrNull};
 use js::jsapi::{JSAutoRealm, JSContext, JSObject};
 use js::rust::HandleObject;
@@ -109,7 +109,7 @@ where
         },
     };
 
-    rooted!(in(window.get_cx()) let callee = UnwrapObject(call_args.callee(), 1));
+    rooted!(in(window.get_cx()) let callee = UnwrapObjectStatic(call_args.callee()));
     if callee.is_null() {
         return Err(Error::Security);
     }

components/script/dom/bindings/proxyhandler.rs

@@ -8,17 +8,13 @@
 
 use crate::dom::bindings::conversions::is_dom_proxy;
 use crate::dom::bindings::utils::delete_property_by_id;
-use js::glue::InvokeGetOwnPropertyDescriptor;
+use js::glue::GetProxyHandlerFamily;
-use js::glue::{GetProxyHandler, GetProxyHandlerFamily};
 use js::glue::{GetProxyPrivate, SetProxyPrivate};
-use js::jsapi::GetObjectProto;
 use js::jsapi::GetStaticPrototype;
 use js::jsapi::Handle as RawHandle;
 use js::jsapi::HandleId as RawHandleId;
 use js::jsapi::HandleObject as RawHandleObject;
 use js::jsapi::JS_DefinePropertyById;
-use js::jsapi::JS_GetPropertyDescriptorById;
-use js::jsapi::MutableHandle as RawMutableHandle;
 use js::jsapi::MutableHandleObject as RawMutableHandleObject;
 use js::jsapi::ObjectOpResult;
 use js::jsapi::{DOMProxyShadowsResult, JSContext, JSObject, PropertyDescriptor};
@@ -62,34 +58,6 @@ pub unsafe fn init() {
     SetDOMProxyInformation(GetProxyHandlerFamily(), Some(shadow_check_callback));
 }
 
-/// Invoke the [[GetOwnProperty]] trap (`getOwnPropertyDescriptor`) on `proxy`,
-/// with argument `id` and return the result, if it is not `undefined`.
-/// Otherwise, walk along the prototype chain to find a property with that
-/// name.
-pub unsafe extern "C" fn get_property_descriptor(
-    cx: *mut JSContext,
-    proxy: RawHandleObject,
-    id: RawHandleId,
-    desc: RawMutableHandle<PropertyDescriptor>,
-) -> bool {
-    let handler = GetProxyHandler(proxy.get());
-    if !InvokeGetOwnPropertyDescriptor(handler, cx, proxy, id, desc) {
-        return false;
-    }
-    if !desc.obj.is_null() {
-        return true;
-    }
-
-    rooted!(in(cx) let mut proto = ptr::null_mut::<JSObject>());
-    if !GetObjectProto(cx, proxy, proto.handle_mut().into()) {
-        // FIXME(#11868) Should assign to desc.obj, desc.get() is a copy.
-        desc.get().obj = ptr::null_mut();
-        return true;
-    }
-
-    JS_GetPropertyDescriptorById(cx, proto.handle().into(), id, desc)
-}
-
 /// Defines an expando on the given `proxy`.
 pub unsafe extern "C" fn define_property(
     cx: *mut JSContext,

components/script/dom/bindings/structuredclone.rs

@@ -176,12 +176,12 @@ unsafe extern "C" fn read_callback(
 }
 
 unsafe extern "C" fn write_callback(
-    _cx: *mut JSContext,
+    cx: *mut JSContext,
     w: *mut JSStructuredCloneWriter,
     obj: RawHandleObject,
     _closure: *mut raw::c_void,
 ) -> bool {
-    if let Ok(blob) = root_from_handleobject::<Blob>(Handle::from_raw(obj)) {
+    if let Ok(blob) = root_from_handleobject::<Blob>(Handle::from_raw(obj), cx) {
         return write_blob(blob, w).is_ok();
     }
     return false;

components/script/dom/bindings/trace.rs

@@ -68,7 +68,7 @@ use hyper::StatusCode;
 use indexmap::IndexMap;
 use ipc_channel::ipc::{IpcReceiver, IpcSender};
 use js::glue::{CallObjectTracer, CallValueTracer};
-use js::jsapi::{GCTraceKindToAscii, Heap, JSObject, JSTracer, TraceKind};
+use js::jsapi::{GCTraceKindToAscii, Heap, JSObject, JSTracer, JobQueue, TraceKind};
 use js::jsval::JSVal;
 use js::rust::{GCMethods, Handle, Runtime};
 use js::typedarray::TypedArray;
@@ -162,6 +162,8 @@ unsafe_no_jsmanaged_fields!(Duration);
 
 unsafe_no_jsmanaged_fields!(TexDataType, TexFormat);
 
+unsafe_no_jsmanaged_fields!(*mut JobQueue);
+
 /// Trace a `JSVal`.
 pub fn trace_jsval(tracer: *mut JSTracer, description: &str, val: &Heap<JSVal>) {
     unsafe {

components/script/dom/bindings/utils.rs

@@ -15,12 +15,12 @@ use crate::dom::bindings::trace::trace_object;
 use crate::dom::windowproxy;
 use js::glue::{CallJitGetterOp, CallJitMethodOp, CallJitSetterOp, IsWrapper};
 use js::glue::{GetCrossCompartmentWrapper, JS_GetReservedSlot, WrapperNew};
-use js::glue::{UnwrapObject, RUST_JSID_TO_INT, RUST_JSID_TO_STRING};
+use js::glue::{UnwrapObjectDynamic, RUST_JSID_TO_INT, RUST_JSID_TO_STRING};
 use js::glue::{RUST_FUNCTION_VALUE_TO_JITINFO, RUST_JSID_IS_INT, RUST_JSID_IS_STRING};
 use js::jsapi::HandleId as RawHandleId;
 use js::jsapi::HandleObject as RawHandleObject;
 use js::jsapi::MutableHandleObject as RawMutableHandleObject;
-use js::jsapi::{CallArgs, DOMCallbacks, GetNonCCWObjectGlobal};
+use js::jsapi::{AutoIdVector, CallArgs, DOMCallbacks, GetNonCCWObjectGlobal};
 use js::jsapi::{Heap, JSAutoRealm, JSContext};
 use js::jsapi::{JSJitInfo, JSObject, JSTracer, JSWrapObjectCallbacks};
 use js::jsapi::{JS_EnumerateStandardClasses, JS_GetLatin1StringCharsAndLength};
@@ -210,7 +210,7 @@ pub unsafe fn find_enum_value<'a, T>(
 
 /// Returns wether `obj` is a platform object
 /// <https://heycam.github.io/webidl/#dfn-platform-object>
-pub fn is_platform_object(obj: *mut JSObject) -> bool {
+pub fn is_platform_object(obj: *mut JSObject, cx: *mut JSContext) -> bool {
     unsafe {
         // Fast-path the common case
         let mut clasp = get_object_class(obj);
@@ -219,7 +219,7 @@ pub fn is_platform_object(obj: *mut JSObject) -> bool {
         }
         // Now for simplicity check for security wrappers before anything else
         if IsWrapper(obj) {
-            let unwrapped_obj = UnwrapObject(obj, /* stopAtWindowProxy = */ 0);
+            let unwrapped_obj = UnwrapObjectDynamic(obj, cx, /* stopAtWindowProxy = */ 0);
             if unwrapped_obj.is_null() {
                 return false;
             }
@@ -342,7 +342,12 @@ pub unsafe fn trace_global(tracer: *mut JSTracer, obj: *mut JSObject) {
 }
 
 /// Enumerate lazy properties of a global object.
-pub unsafe extern "C" fn enumerate_global(cx: *mut JSContext, obj: RawHandleObject) -> bool {
+pub unsafe extern "C" fn enumerate_global(
+    cx: *mut JSContext,
+    obj: RawHandleObject,
+    _props: *mut AutoIdVector,
+    _enumerable_only: bool,
+) -> bool {
     assert!(JS_IsGlobalObject(obj.get()));
     if !JS_EnumerateStandardClasses(cx, obj) {
         return false;
@@ -463,7 +468,7 @@ unsafe fn generic_call(
     let depth = (*info).depth;
     let proto_check =
         |class: &'static DOMClass| class.interface_chain[depth as usize] as u16 == proto_id;
-    let this = match private_from_proto_check(obj.get(), proto_check) {
+    let this = match private_from_proto_check(obj.get(), cx, proto_check) {
         Ok(val) => val,
         Err(()) => {
             if is_lenient {

components/script/dom/customelementregistry.rs

@@ -35,7 +35,7 @@ use crate::script_thread::ScriptThread;
 use dom_struct::dom_struct;
 use html5ever::{LocalName, Namespace, Prefix};
 use js::conversions::ToJSValConvertible;
-use js::glue::UnwrapObject;
+use js::glue::UnwrapObjectStatic;
 use js::jsapi::{HandleValueArray, Heap, IsCallable, IsConstructor};
 use js::jsapi::{JSAutoRealm, JSContext, JSObject};
 use js::jsval::{JSVal, NullValue, ObjectValue, UndefinedValue};
@@ -259,7 +259,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
 
         // Step 1
         // We must unwrap the constructor as all wrappers are constructable if they are callable.
-        rooted!(in(cx) let unwrapped_constructor = unsafe { UnwrapObject(constructor.get(), 1) });
+        rooted!(in(cx) let unwrapped_constructor = unsafe { UnwrapObjectStatic(constructor.get()) });
 
         if unwrapped_constructor.is_null() {
             // We do not have permission to access the unwrapped constructor.

components/script/dom/globalscope.rs

@@ -6,7 +6,7 @@ use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::EventSourceBinding::EventSourceBinding::EventSourceMethods;
 use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
 use crate::dom::bindings::codegen::Bindings::WorkerGlobalScopeBinding::WorkerGlobalScopeMethods;
-use crate::dom::bindings::conversions::root_from_object;
+use crate::dom::bindings::conversions::{root_from_object, root_from_object_static};
 use crate::dom::bindings::error::{report_pending_exception, ErrorInfo};
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::DomObject;
@@ -41,7 +41,7 @@ use crate::timers::{OneshotTimers, TimerCallback};
 use devtools_traits::{ScriptToDevtoolsControlMsg, WorkerId};
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
-use js::glue::{IsWrapper, UnwrapObject};
+use js::glue::{IsWrapper, UnwrapObjectDynamic};
 use js::jsapi::JSObject;
 use js::jsapi::{CurrentGlobalOrNull, GetNonCCWObjectGlobal};
 use js::jsapi::{HandleObject, Heap};
@@ -233,22 +233,25 @@ impl GlobalScope {
     pub unsafe fn from_object(obj: *mut JSObject) -> DomRoot<Self> {
         assert!(!obj.is_null());
         let global = GetNonCCWObjectGlobal(obj);
-        global_scope_from_global(global)
+        global_scope_from_global_static(global)
     }
 
     /// Returns the global scope for the given JSContext
     #[allow(unsafe_code)]
     pub unsafe fn from_context(cx: *mut JSContext) -> DomRoot<Self> {
         let global = CurrentGlobalOrNull(cx);
-        global_scope_from_global(global)
+        global_scope_from_global(global, cx)
     }
 
     /// Returns the global object of the realm that the given JS object
     /// was created in, after unwrapping any wrappers.
     #[allow(unsafe_code)]
-    pub unsafe fn from_object_maybe_wrapped(mut obj: *mut JSObject) -> DomRoot<Self> {
+    pub unsafe fn from_object_maybe_wrapped(
+        mut obj: *mut JSObject,
+        cx: *mut JSContext,
+    ) -> DomRoot<Self> {
         if IsWrapper(obj) {
-            obj = UnwrapObject(obj, /* stopAtWindowProxy = */ 0);
+            obj = UnwrapObjectDynamic(obj, cx, /* stopAtWindowProxy = */ 0);
             assert!(!obj.is_null());
         }
         GlobalScope::from_object(obj)
@@ -663,16 +666,23 @@ impl GlobalScope {
     }
 
     /// Perform a microtask checkpoint.
+    #[allow(unsafe_code)]
     pub fn perform_a_microtask_checkpoint(&self) {
+        unsafe {
             self.microtask_queue.checkpoint(
+                self.get_cx(),
                 |_| Some(DomRoot::from_ref(self)),
                 vec![DomRoot::from_ref(self)],
             );
         }
+    }
 
     /// Enqueue a microtask for subsequent execution.
+    #[allow(unsafe_code)]
     pub fn enqueue_microtask(&self, job: Microtask) {
-        self.microtask_queue.enqueue(job);
+        unsafe {
+            self.microtask_queue.enqueue(job, self.get_cx());
+        }
     }
 
     /// Create a new sender/receiver pair that can be used to implement an on-demand
@@ -749,7 +759,7 @@ impl GlobalScope {
             if global.is_null() {
                 None
             } else {
-                Some(global_scope_from_global(global))
+                Some(global_scope_from_global(global, cx))
             }
         }
     }
@@ -797,12 +807,27 @@ fn timestamp_in_ms(time: Timespec) -> u64 {
 
 /// Returns the Rust global scope from a JS global object.
 #[allow(unsafe_code)]
-unsafe fn global_scope_from_global(global: *mut JSObject) -> DomRoot<GlobalScope> {
+unsafe fn global_scope_from_global(
+    global: *mut JSObject,
+    cx: *mut JSContext,
+) -> DomRoot<GlobalScope> {
     assert!(!global.is_null());
     let clasp = get_object_class(global);
     assert_ne!(
         ((*clasp).flags & (JSCLASS_IS_DOMJSCLASS | JSCLASS_IS_GLOBAL)),
         0
     );
-    root_from_object(global).unwrap()
+    root_from_object(global, cx).unwrap()
+}
+
+/// Returns the Rust global scope from a JS global object.
+#[allow(unsafe_code)]
+unsafe fn global_scope_from_global_static(global: *mut JSObject) -> DomRoot<GlobalScope> {
+    assert!(!global.is_null());
+    let clasp = get_object_class(global);
+    assert_ne!(
+        ((*clasp).flags & (JSCLASS_IS_DOMJSCLASS | JSCLASS_IS_GLOBAL)),
+        0
+    );
+    root_from_object_static(global).unwrap()
 }

components/script/dom/promise.rs

@@ -286,7 +286,7 @@ unsafe extern "C" fn native_handler_callback(
     rooted!(in(cx) let v = *GetFunctionNativeReserved(args.callee(), SLOT_NATIVEHANDLER));
     assert!(v.get().is_object());
 
-    let handler = root_from_object::<PromiseNativeHandler>(v.to_object())
+    let handler = root_from_object::<PromiseNativeHandler>(v.to_object(), cx)
         .expect("unexpected value for native handler in promise native handler callback");
 
     rooted!(in(cx) let v = *GetFunctionNativeReserved(args.callee(), SLOT_NATIVEHANDLER_TASK));

components/script/dom/windowproxy.rs

@@ -6,7 +6,7 @@ use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::conversions::{root_from_handleobject, ToJSValConvertible};
 use crate::dom::bindings::error::{throw_dom_exception, Error};
 use crate::dom::bindings::inheritance::Castable;
-use crate::dom::bindings::proxyhandler::{fill_property_descriptor, get_property_descriptor};
+use crate::dom::bindings::proxyhandler::fill_property_descriptor;
 use crate::dom::bindings::reflector::{DomObject, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::bindings::str::DOMString;
@@ -712,7 +712,7 @@ unsafe fn GetSubframeWindowProxy(
         let mut slot = UndefinedValue();
         GetProxyPrivate(*proxy, &mut slot);
         rooted!(in(cx) let target = slot.to_object());
-        if let Ok(win) = root_from_handleobject::<Window>(target.handle()) {
+        if let Ok(win) = root_from_handleobject::<Window>(target.handle(), cx) {
             let browsing_context_id = win.window_proxy().browsing_context_id();
             let (result_sender, result_receiver) = ipc::channel().unwrap();
 
@@ -730,7 +730,9 @@ unsafe fn GetSubframeWindowProxy(
                 .and_then(|maybe_bcid| maybe_bcid)
                 .and_then(ScriptThread::find_window_proxy)
                 .map(|proxy| (proxy, (JSPROP_ENUMERATE | JSPROP_READONLY) as u32));
-        } else if let Ok(win) = root_from_handleobject::<DissimilarOriginWindow>(target.handle()) {
+        } else if let Ok(win) =
+            root_from_handleobject::<DissimilarOriginWindow>(target.handle(), cx)
+        {
             let browsing_context_id = win.window_proxy().browsing_context_id();
             let (result_sender, result_receiver) = ipc::channel().unwrap();
 
@@ -912,7 +914,6 @@ static PROXY_HANDLER: ProxyTraps = ProxyTraps {
     set: Some(set),
     call: None,
     construct: None,
-    getPropertyDescriptor: Some(get_property_descriptor),
     hasOwn: None,
     getOwnEnumerablePropertyKeys: None,
     nativeCall: None,
@@ -1049,7 +1050,6 @@ static XORIGIN_PROXY_HANDLER: ProxyTraps = ProxyTraps {
     set: Some(set_xorigin),
     call: None,
     construct: None,
-    getPropertyDescriptor: Some(getOwnPropertyDescriptor_xorigin),
     hasOwn: Some(has_xorigin),
     getOwnEnumerablePropertyKeys: None,
     nativeCall: None,

components/script/dom/workerglobalscope.rs

@@ -131,7 +131,7 @@ impl WorkerGlobalScope {
                 init.resource_threads,
                 timer_event_chan,
                 MutableOrigin::new(init.origin),
-                Default::default(),
+                runtime.microtask_queue.clone(),
             ),
             worker_id: init.worker_id,
             worker_name,

components/script/microtask.rs

@@ -16,6 +16,7 @@ use crate::dom::htmlmediaelement::MediaElementMicrotask;
 use crate::dom::mutationobserver::MutationObserver;
 use crate::script_runtime::notify_about_rejected_promises;
 use crate::script_thread::ScriptThread;
+use js::jsapi::{JSContext, JobQueueIsEmpty, JobQueueMayNotBeEmpty};
 use msg::constellation_msg::PipelineId;
 use std::cell::Cell;
 use std::mem;
@@ -54,14 +55,21 @@ pub struct EnqueuedPromiseCallback {
 impl MicrotaskQueue {
     /// Add a new microtask to this queue. It will be invoked as part of the next
     /// microtask checkpoint.
-    pub fn enqueue(&self, job: Microtask) {
+    #[allow(unsafe_code)]
+    pub unsafe fn enqueue(&self, job: Microtask, cx: *mut JSContext) {
         self.microtask_queue.borrow_mut().push(job);
+        JobQueueMayNotBeEmpty(cx);
     }
 
     /// <https://html.spec.whatwg.org/multipage/#perform-a-microtask-checkpoint>
     /// Perform a microtask checkpoint, executing all queued microtasks until the queue is empty.
-    pub fn checkpoint<F>(&self, target_provider: F, globalscopes: Vec<DomRoot<GlobalScope>>)
+    #[allow(unsafe_code)]
-    where
+    pub unsafe fn checkpoint<F>(
+        &self,
+        cx: *mut JSContext,
+        target_provider: F,
+        globalscopes: Vec<DomRoot<GlobalScope>>,
+    ) where
         F: Fn(PipelineId) -> Option<DomRoot<GlobalScope>>,
     {
         if self.performing_a_microtask_checkpoint.get() {
@@ -76,7 +84,11 @@ impl MicrotaskQueue {
             rooted_vec!(let mut pending_queue);
             mem::swap(&mut *pending_queue, &mut *self.microtask_queue.borrow_mut());
 
-            for job in pending_queue.iter() {
+            for (idx, job) in pending_queue.iter().enumerate() {
+                if idx == pending_queue.len() - 1 && self.microtask_queue.borrow().is_empty() {
+                    JobQueueIsEmpty(cx);
+                }
+
                 match *job {
                     Microtask::Promise(ref job) => {
                         if let Some(target) = target_provider(job.pipeline) {
@@ -109,4 +121,8 @@ impl MicrotaskQueue {
         // Step 5
         self.performing_a_microtask_checkpoint.set(false);
     }
+
+    pub fn empty(&self) -> bool {
+        self.microtask_queue.borrow().is_empty()
+    }
 }

components/script/script_runtime.rs

@@ -21,15 +21,14 @@ use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::dom::promiserejectionevent::PromiseRejectionEvent;
-use crate::microtask::{EnqueuedPromiseCallback, Microtask};
+use crate::microtask::{EnqueuedPromiseCallback, Microtask, MicrotaskQueue};
 use crate::script_thread::trace_thread;
 use crate::task::TaskBox;
 use crate::task_source::{TaskSource, TaskSourceName};
-use js::glue::CollectServoSizes;
+use js::glue::{CollectServoSizes, CreateJobQueue, DeleteJobQueue, JobQueueTraps, SetBuildId};
-use js::glue::SetBuildId;
 use js::jsapi::ContextOptionsRef;
 use js::jsapi::{BuildIdCharVector, DisableIncrementalGC, GCDescription, GCProgress};
-use js::jsapi::{HandleObject, Heap};
+use js::jsapi::{HandleObject, Heap, JobQueue};
 use js::jsapi::{JSContext, JSTracer, SetDOMCallbacks, SetGCSliceCallback};
 use js::jsapi::{JSGCInvocationKind, JSGCStatus, JS_AddExtraGCRootsTracer, JS_SetGCCallback};
 use js::jsapi::{JSGCMode, JSGCParamKey, JS_SetGCParameter, JS_SetGlobalJitCompilerOption};
@@ -37,9 +36,7 @@ use js::jsapi::{
     JSJitCompilerOption, JS_SetOffthreadIonCompilationEnabled, JS_SetParallelParsingEnabled,
 };
 use js::jsapi::{JSObject, PromiseRejectionHandlingState, SetPreserveWrapperCallback};
-use js::jsapi::{
+use js::jsapi::{SetJobQueue, SetProcessBuildIdOp, SetPromiseRejectionTrackerCallback};
-    SetEnqueuePromiseJobCallback, SetProcessBuildIdOp, SetPromiseRejectionTrackerCallback,
-};
 use js::panic::wrap_panic;
 use js::rust::wrappers::{GetPromiseIsHandled, GetPromiseResult};
 use js::rust::Handle;
@@ -60,10 +57,17 @@ use std::os;
 use std::os::raw::c_void;
 use std::panic::AssertUnwindSafe;
 use std::ptr;
+use std::rc::Rc;
 use std::sync::Arc;
 use style::thread_state::{self, ThreadState};
 use time::{now, Tm};
 
+static JOB_QUEUE_TRAPS: JobQueueTraps = JobQueueTraps {
+    getIncumbentGlobal: Some(get_incumbent_global),
+    enqueuePromiseJob: Some(enqueue_promise_job),
+    empty: Some(empty),
+};
+
 /// Common messages used to control the event loops in both the script and the worker
 pub enum CommonScriptMsg {
     /// Requests that the script thread measure its memory usage. The results are sent back via the
@@ -134,25 +138,52 @@ pub trait ScriptPort {
     fn recv(&self) -> Result<CommonScriptMsg, ()>;
 }
 
+#[allow(unsafe_code)]
+unsafe extern "C" fn get_incumbent_global(_: *const c_void, _: *mut JSContext) -> *mut JSObject {
+    wrap_panic(
+        AssertUnwindSafe(|| {
+            GlobalScope::incumbent()
+                .map(|g| g.reflector().get_jsobject().get())
+                .unwrap_or(ptr::null_mut())
+        }),
+        ptr::null_mut(),
+    )
+}
+
+#[allow(unsafe_code)]
+unsafe extern "C" fn empty(extra: *const c_void) -> bool {
+    wrap_panic(
+        AssertUnwindSafe(|| {
+            let microtask_queue = &*(extra as *const MicrotaskQueue);
+            microtask_queue.empty()
+        }),
+        false,
+    )
+}
+
 /// SM callback for promise job resolution. Adds a promise callback to the current
 /// global's microtask queue.
 #[allow(unsafe_code)]
-unsafe extern "C" fn enqueue_job(
+unsafe extern "C" fn enqueue_promise_job(
+    extra: *const c_void,
     cx: *mut JSContext,
     _promise: HandleObject,
     job: HandleObject,
     _allocation_site: HandleObject,
     incumbent_global: HandleObject,
-    _data: *mut c_void,
 ) -> bool {
     wrap_panic(
         AssertUnwindSafe(|| {
+            let microtask_queue = &*(extra as *const MicrotaskQueue);
             let global = GlobalScope::from_object(incumbent_global.get());
             let pipeline = global.pipeline_id();
-            global.enqueue_microtask(Microtask::Promise(EnqueuedPromiseCallback {
+            microtask_queue.enqueue(
+                Microtask::Promise(EnqueuedPromiseCallback {
                     callback: PromiseJobCallback::new(cx, job.get()),
-                pipeline: pipeline,
+                    pipeline,
-            }));
+                }),
+                cx,
+            );
             true
         }),
         false,
@@ -309,10 +340,18 @@ pub fn notify_about_rejected_promises(global: &GlobalScope) {
 }
 
 #[derive(JSTraceable)]
-pub struct Runtime(RustRuntime);
+pub struct Runtime {
+    rt: RustRuntime,
+    pub microtask_queue: Rc<MicrotaskQueue>,
+    job_queue: *mut JobQueue,
+}
 
 impl Drop for Runtime {
+    #[allow(unsafe_code)]
     fn drop(&mut self) {
+        unsafe {
+            DeleteJobQueue(self.job_queue);
+        }
         THREAD_ACTIVE.with(|t| {
             LiveDOMReferences::destruct();
             t.set(false);
@@ -323,7 +362,7 @@ impl Drop for Runtime {
 impl Deref for Runtime {
     type Target = RustRuntime;
     fn deref(&self) -> &RustRuntime {
-        &self.0
+        &self.rt
     }
 }
 
@@ -370,7 +409,12 @@ unsafe fn new_rt_and_cx_with_parent(parent: Option<ParentRuntime>) -> Runtime {
     // Pre barriers aren't working correctly at the moment
     DisableIncrementalGC(cx);
 
-    SetEnqueuePromiseJobCallback(cx, Some(enqueue_job), ptr::null_mut());
+    let microtask_queue = Rc::new(MicrotaskQueue::default());
+    let job_queue = CreateJobQueue(
+        &JOB_QUEUE_TRAPS,
+        &*microtask_queue as *const _ as *const c_void,
+    );
+    SetJobQueue(cx, job_queue);
     SetPromiseRejectionTrackerCallback(cx, Some(promise_rejection_tracker), ptr::null_mut());
 
     set_gc_zeal_options(cx);
@@ -407,7 +451,7 @@ unsafe fn new_rt_and_cx_with_parent(parent: Option<ParentRuntime>) -> Runtime {
     );
     JS_SetGlobalJitCompilerOption(
         cx,
-        JSJitCompilerOption::JSJITCOMPILER_ION_WARMUP_TRIGGER,
+        JSJitCompilerOption::JSJITCOMPILER_ION_NORMAL_WARMUP_TRIGGER,
         if pref!(js.ion.unsafe_eager_compilation.enabled) {
             0
         } else {
@@ -511,7 +555,11 @@ unsafe fn new_rt_and_cx_with_parent(parent: Option<ParentRuntime>) -> Runtime {
         JS_SetGCParameter(cx, JSGCParamKey::JSGC_MAX_EMPTY_CHUNK_COUNT, val as u32);
     }
 
-    Runtime(runtime)
+    Runtime {
+        rt: runtime,
+        microtask_queue,
+        job_queue,
+    }
 }
 
 fn in_range<T: PartialOrd + Copy>(val: T, min: T, max: T) -> Option<T> {

components/script/script_thread.rs

@@ -845,11 +845,16 @@ impl ScriptThread {
     }
 
     // https://html.spec.whatwg.org/multipage/#await-a-stable-state
+    #[allow(unsafe_code)]
     pub fn await_stable_state(task: Microtask) {
         SCRIPT_THREAD_ROOT.with(|root| {
             if let Some(script_thread) = root.get() {
-                let script_thread = unsafe { &*script_thread };
+                unsafe {
-                script_thread.microtask_queue.enqueue(task);
+                    let script_thread = &*script_thread;
+                    script_thread
+                        .microtask_queue
+                        .enqueue(task, script_thread.get_cx());
+                }
             }
         });
     }
@@ -1123,6 +1128,8 @@ impl ScriptThread {
             devtools_port: devtools_port,
             devtools_sender: ipc_devtools_sender,
 
+            microtask_queue: runtime.microtask_queue.clone(),
+
             js_runtime: Rc::new(runtime),
             topmost_mouse_over_target: MutNullableDom::new(Default::default()),
             closed_pipelines: DomRefCell::new(HashSet::new()),
@@ -1133,8 +1140,6 @@ impl ScriptThread {
 
             content_process_shutdown_chan: state.content_process_shutdown_chan,
 
-            microtask_queue: Default::default(),
-
             mutation_observer_microtask_queued: Default::default(),
 
             mutation_observers: Default::default(),
@@ -3541,13 +3546,17 @@ impl ScriptThread {
         }
     }
 
+    #[allow(unsafe_code)]
     pub fn enqueue_microtask(job: Microtask) {
-        SCRIPT_THREAD_ROOT.with(|root| {
+        SCRIPT_THREAD_ROOT.with(|root| unsafe {
-            let script_thread = unsafe { &*root.get().unwrap() };
+            let script_thread = &*root.get().unwrap();
-            script_thread.microtask_queue.enqueue(job);
+            script_thread
+                .microtask_queue
+                .enqueue(job, script_thread.get_cx());
         });
     }
 
+    #[allow(unsafe_code)]
     fn perform_a_microtask_checkpoint(&self) {
         let globals = self
             .documents
@@ -3556,8 +3565,13 @@ impl ScriptThread {
             .map(|(_id, document)| document.global())
             .collect();
 
-        self.microtask_queue
+        unsafe {
-            .checkpoint(|id| self.documents.borrow().find_global(id), globals)
+            self.microtask_queue.checkpoint(
+                self.get_cx(),
+                |id| self.documents.borrow().find_global(id),
+                globals,
+            )
+        }
     }
 }
 

etc/taskcluster/docker/build.dockerfile

@@ -19,6 +19,8 @@ RUN \
         #
         # Bindgen (for SpiderMonkey bindings)
         clang \
+        llvm \
+        llvm-dev \
         #
         # GStreamer
         libgstreamer-plugins-bad1.0-dev \