Update to SpiderMonkey 66.

2025-06-06 16:45:39 +00:00 · 2019-05-06 11:38:34 -04:00 · 2019-05-06 11:38:34 -04:00 · 4328713f71
commit 4328713f71
parent d0d3401361
31 changed files with 150 additions and 144 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -2803,21 +2803,21 @@ dependencies = [

 [[package]]
 name = "mozjs"
-version = "0.10.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+version = "0.11.0"
+source = "git+https://github.com/servo/rust-mozjs?rev=357d1db91e4e49c3f148fe05fdfae5f8f0834ca8#357d1db91e4e49c3f148fe05fdfae5f8f0834ca8"
 dependencies = [
 "cc 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.44 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "mozjs_sys 0.61.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mozjs_sys 0.66.0 (git+https://github.com/servo/mozjs?rev=e21c05b415dfc246175ff8d5fc48b0e8c5b4e9e9)",
 "num-traits 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
 name = "mozjs_sys"
-version = "0.61.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+version = "0.66.0"
+source = "git+https://github.com/servo/mozjs?rev=e21c05b415dfc246175ff8d5fc48b0e8c5b4e9e9#e21c05b415dfc246175ff8d5fc48b0e8c5b4e9e9"
 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)",
@ -3593,7 +3593,7 @@ 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 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "mozjs 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "mozjs 0.11.0 (git+https://github.com/servo/rust-mozjs?rev=357d1db91e4e49c3f148fe05fdfae5f8f0834ca8)",
 "msg 0.0.1",
 "net_traits 0.0.1",
 "num-traits 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
@ -5593,8 +5593,8 @@ dependencies = [
 "checksum miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c1f2f3b1cf331de6896aabf6e9d55dca90356cc9960cca7eaaf408a355ae919"
 "checksum mitochondria 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9de3eca27871df31c33b807f834b94ef7d000956f57aa25c5aed9c5f0aae8f6f"
 "checksum mozangle 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c9ba1ce5212fd56a71cfbc463aedd4ece76090d98b96d5122f84dedffa0cc508"
-"checksum mozjs 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "622108d35f4fdd68b3aa39bfe9bedaee5fa9efd19711d046e1d56ff607c0a36f"
-"checksum mozjs_sys 0.61.13 (registry+https://github.com/rust-lang/crates.io-index)" = "c7d35502544cf3e70b305e028c6ca9e4c3d5a48264af220f8341598f54d189ba"
+"checksum mozjs 0.11.0 (git+https://github.com/servo/rust-mozjs?rev=357d1db91e4e49c3f148fe05fdfae5f8f0834ca8)" = "<none>"
+"checksum mozjs_sys 0.66.0 (git+https://github.com/servo/mozjs?rev=e21c05b415dfc246175ff8d5fc48b0e8c5b4e9e9)" = "<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"
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@ -65,7 +65,7 @@ indexmap = "1.0.2"
 ipc-channel = "0.11"
 itertools = "0.8"
 jstraceable_derive = {path = "../jstraceable_derive"}
-js = {package = "mozjs", version = "0.10.1"}
+js = {package = "mozjs", git = "https://github.com/servo/rust-mozjs", rev = "357d1db91e4e49c3f148fe05fdfae5f8f0834ca8"}
 keyboard-types = "0.4.4"
 lazy_static = "1"
 libc = "0.2"
--- a/components/script/compartments.rs
+++ b/components/script/compartments.rs
@ -3,7 +3,7 @@
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

 use crate::dom::globalscope::GlobalScope;
-use js::jsapi::{GetCurrentRealmOrNull, JSAutoCompartment};
+use js::jsapi::{GetCurrentRealmOrNull, JSAutoRealm};

 pub struct AlreadyInCompartment(());

@ -20,7 +20,7 @@ impl AlreadyInCompartment {
 #[derive(Clone, Copy)]
 pub enum InCompartment<'a> {
    Already(&'a AlreadyInCompartment),
-    Entered(&'a JSAutoCompartment),
+    Entered(&'a JSAutoRealm),
 }

 impl<'a> InCompartment<'a> {
@ -28,7 +28,7 @@ impl<'a> InCompartment<'a> {
        InCompartment::Already(token)
    }

-    pub fn entered(token: &JSAutoCompartment) -> InCompartment {
+    pub fn entered(token: &JSAutoRealm) -> InCompartment {
        InCompartment::Entered(token)
    }
 }
--- a/components/script/devtools.rs
+++ b/components/script/devtools.rs
@ -23,7 +23,7 @@ use devtools_traits::{AutoMargins, CachedConsoleMessage, CachedConsoleMessageTyp
 use devtools_traits::{ComputedNodeLayout, ConsoleAPI, PageError};
 use devtools_traits::{EvaluateJSReply, Modification, NodeInfo, TimelineMarker};
 use ipc_channel::ipc::IpcSender;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use js::jsval::UndefinedValue;
 use js::rust::wrappers::ObjectClassName;
 use msg::constellation_msg::PipelineId;
@ -37,7 +37,7 @@ pub fn handle_evaluate_js(global: &GlobalScope, eval: String, reply: IpcSender<E
    let result = unsafe {
        let cx = global.get_cx();
        let globalhandle = global.reflector().get_jsobject();
-        let _ac = JSAutoCompartment::new(cx, globalhandle.get());
+        let _ac = JSAutoRealm::new(cx, globalhandle.get());
        rooted!(in(cx) let mut rval = UndefinedValue());
        global.evaluate_js_on_global_with_result(&eval, rval.handle_mut());

--- a/components/script/dom/audiobuffer.rs
+++ b/components/script/dom/audiobuffer.rs
@ -14,7 +14,7 @@ use crate::dom::bindings::root::DomRoot;
 use crate::dom::window::Window;
 use dom_struct::dom_struct;
 use js::jsapi::JS_GetArrayBufferViewBuffer;
-use js::jsapi::{Heap, JSAutoCompartment, JSContext, JSObject};
+use js::jsapi::{Heap, JSAutoRealm, JSContext, JSObject};
 use js::rust::wrappers::JS_DetachArrayBuffer;
 use js::rust::CustomAutoRooterGuard;
 use js::typedarray::{CreateWith, Float32Array};
@ -127,7 +127,7 @@ impl AudioBuffer {
    #[allow(unsafe_code)]
    unsafe fn restore_js_channel_data(&self, cx: *mut JSContext) -> bool {
        let global = self.global();
-        let _ac = JSAutoCompartment::new(cx, global.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, global.reflector().get_jsobject().get());
        for (i, channel) in self.js_channels.borrow_mut().iter().enumerate() {
            if !channel.get().is_null() {
                // Already have data in JS array.
--- a/components/script/dom/bindings/callback.rs
+++ b/components/script/dom/bindings/callback.rs
@ -14,9 +14,9 @@ use crate::dom::bindings::utils::AsCCharPtrPtr;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::window::Window;
 use js::jsapi::Heap;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use js::jsapi::{AddRawValueRoot, IsCallable, JSContext, JSObject};
-use js::jsapi::{JSCompartment, JS_EnterCompartment, JS_LeaveCompartment, RemoveRawValueRoot};
+use js::jsapi::{EnterRealm, LeaveRealm, Realm, RemoveRawValueRoot};
 use js::jsval::{JSVal, ObjectValue, UndefinedValue};
 use js::rust::wrappers::{JS_GetProperty, JS_WrapObject};
 use js::rust::{MutableHandleObject, Runtime};
@ -229,7 +229,7 @@ pub struct CallSetup {
    /// The `JSContext` used for the call.
    cx: *mut JSContext,
    /// The compartment we were in before the call.
-    old_compartment: *mut JSCompartment,
+    old_realm: *mut Realm,
    /// The exception handling used for the call.
    handling: ExceptionHandling,
    /// <https://heycam.github.io/webidl/#es-invoking-callback-functions>
@ -255,7 +255,7 @@ impl CallSetup {
        CallSetup {
            exception_global: global,
            cx: cx,
-            old_compartment: unsafe { JS_EnterCompartment(cx, callback.callback()) },
+            old_realm: unsafe { EnterRealm(cx, callback.callback()) },
            handling: handling,
            entry_script: Some(aes),
            incumbent_script: ais,
@ -271,9 +271,9 @@ impl CallSetup {
 impl Drop for CallSetup {
    fn drop(&mut self) {
        unsafe {
-            JS_LeaveCompartment(self.cx, self.old_compartment);
+            LeaveRealm(self.cx, self.old_realm);
            if self.handling == ExceptionHandling::Report {
-                let _ac = JSAutoCompartment::new(
+                let _ac = JSAutoRealm::new(
                    self.cx,
                    self.exception_global.reflector().get_jsobject().get(),
                );
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@ -458,7 +458,7 @@ class CGMethodCall(CGThing):
            pickFirstSignature("%s.get().is_object() && "
                               "{ rooted!(in(cx) let obj = %s.get().to_object()); "
                               "let mut is_date = false; "
-                               "assert!(JS_ObjectIsDate(cx, obj.handle(), &mut is_date)); "
+                               "assert!(ObjectIsDate(cx, obj.handle(), &mut is_date)); "
                               "is_date }" %
                               (distinguishingArg, distinguishingArg),
                               lambda s: (s[1][distinguishingIndex].type.isDate() or
@ -795,7 +795,7 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
        #    our own implementation code.
        templateBody = fill(
            """
-            { // Scope for our JSAutoCompartment.
+            { // Scope for our JSAutoRealm.

                rooted!(in(cx) let globalObj = CurrentGlobalOrNull(cx));
                let promiseGlobal = GlobalScope::from_object_maybe_wrapped(globalObj.handle().get());
@ -2709,7 +2709,7 @@ assert!(!scope.get().is_null());
 assert!(((*get_object_class(scope.get())).flags & JSCLASS_IS_GLOBAL) != 0);

 rooted!(in(cx) let mut proto = ptr::null_mut::<JSObject>());
-let _ac = JSAutoCompartment::new(cx, scope.get());
+let _ac = JSAutoRealm::new(cx, scope.get());
 GetProtoObject(cx, scope, proto.handle_mut());
 assert!(!proto.is_null());

@ -2764,7 +2764,7 @@ assert!(!obj.is_null());

 (*raw).init_reflector(obj.get());

-let _ac = JSAutoCompartment::new(cx, obj.get());
+let _ac = JSAutoRealm::new(cx, obj.get());
 rooted!(in(cx) let mut proto = ptr::null_mut::<JSObject>());
 GetProtoObject(cx, obj.handle(), proto.handle_mut());
 assert!(JS_SplicePrototype(cx, obj.handle(), proto.handle()));
@ -2883,7 +2883,7 @@ class CGCreateInterfaceObjectsMethod(CGAbstractMethod):
        name = self.descriptor.interface.identifier.name
        if self.descriptor.interface.isNamespace():
            if self.descriptor.interface.getExtendedAttribute("ProtoObjectHack"):
-                proto = "JS_GetObjectPrototype(cx, global)"
+                proto = "GetRealmObjectPrototype(cx)"
            else:
                proto = "JS_NewPlainObject(cx)"
            if self.properties.static_methods.length():
@ -2919,11 +2919,12 @@ assert!((*cache)[PrototypeList::Constructor::%(id)s as usize].is_null());
        parentName = self.descriptor.getParentName()
        if not parentName:
            if self.descriptor.interface.getExtendedAttribute("ExceptionClass"):
-                getPrototypeProto = "prototype_proto.set(JS_GetErrorPrototype(cx))"
+                protoGetter = "GetRealmErrorPrototype"
            elif self.descriptor.interface.isIteratorInterface():
-                getPrototypeProto = "prototype_proto.set(JS_GetIteratorPrototype(cx))"
+                protoGetter = "GetRealmIteratorPrototype"
            else:
-                getPrototypeProto = "prototype_proto.set(JS_GetObjectPrototype(cx, global))"
+                protoGetter = "GetRealmObjectPrototype"
+            getPrototypeProto = "prototype_proto.set(%s(cx))" % protoGetter
        else:
            getPrototypeProto = ("%s::GetProtoObject(cx, global, prototype_proto.handle_mut())" %
                                 toBindingNamespace(parentName))
@ -2981,14 +2982,13 @@ assert!((*cache)[PrototypeList::ID::%(id)s as usize].is_null());
            else:
                properties["length"] = 0
            parentName = self.descriptor.getParentName()
+            code.append(CGGeneric("rooted!(in(cx) let mut interface_proto = ptr::null_mut::<JSObject>());"))
            if parentName:
                parentName = toBindingNamespace(parentName)
                code.append(CGGeneric("""
-rooted!(in(cx) let mut interface_proto = ptr::null_mut::<JSObject>());
 %s::GetConstructorObject(cx, global, interface_proto.handle_mut());""" % parentName))
            else:
-                code.append(CGGeneric("""
-rooted!(in(cx) let interface_proto = JS_GetFunctionPrototype(cx, global));"""))
+                code.append(CGGeneric("interface_proto.set(GetRealmFunctionPrototype(cx));"))
            code.append(CGGeneric("""\
 assert!(!interface_proto.is_null());

@ -5544,7 +5544,7 @@ if args.callee() == new_target.get() {
 rooted!(in(cx) let mut prototype = ptr::null_mut::<JSObject>());
 {
    rooted!(in(cx) let mut proto_val = UndefinedValue());
-    let _ac = JSAutoCompartment::new(cx, new_target.get());
+    let _ac = JSAutoRealm::new(cx, new_target.get());
    if !JS_GetProperty(cx, new_target.handle(), b"prototype\\0".as_ptr() as *const _, proto_val.handle_mut()) {
        return false;
    }
@ -5765,7 +5765,7 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
        'js::jsapi::Heap',
        'js::jsapi::INTERNED_STRING_TO_JSID',
        'js::jsapi::IsCallable',
-        'js::jsapi::JSAutoCompartment',
+        'js::jsapi::JSAutoRealm',
        'js::jsapi::JSCLASS_FOREGROUND_FINALIZE',
        'js::jsapi::JSCLASS_RESERVED_SLOTS_SHIFT',
        'js::jsapi::JSClass',
@ -5804,11 +5804,10 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
        'js::rust::wrappers::JS_DefineProperty',
        'js::rust::wrappers::JS_DefinePropertyById2',
        'js::jsapi::JS_ForwardGetPropertyTo',
-        'js::jsapi::JS_GetErrorPrototype',
-        'js::rust::wrappers::JS_GetFunctionPrototype',
-        'js::jsapi::JS_GetGlobalForObject',
-        'js::jsapi::JS_GetIteratorPrototype',
-        'js::rust::wrappers::JS_GetObjectPrototype',
+        'js::jsapi::GetRealmErrorPrototype',
+        'js::jsapi::GetRealmFunctionPrototype',
+        'js::jsapi::GetRealmIteratorPrototype',
+        'js::jsapi::GetRealmObjectPrototype',
        'js::rust::wrappers::JS_GetProperty',
        'js::jsapi::JS_GetPropertyById',
        'js::jsapi::JS_GetPropertyDescriptorById',
@ -5819,7 +5818,7 @@ def generate_imports(config, cgthings, descriptors, callbacks=None, dictionaries
        'js::jsapi::JS_NewObject',
        'js::rust::wrappers::JS_NewObjectWithGivenProto',
        'js::rust::wrappers::JS_NewObjectWithoutMetadata',
-        'js::rust::wrappers::JS_ObjectIsDate',
+        'js::rust::wrappers::ObjectIsDate',
        'js::rust::wrappers::JS_SetImmutablePrototype',
        'js::rust::wrappers::JS_SetProperty',
        'js::rust::wrappers::JS_SetPrototype',
--- a/components/script/dom/bindings/htmlconstructor.rs
+++ b/components/script/dom/bindings/htmlconstructor.rs
@ -81,7 +81,7 @@ use html5ever::interface::QualName;
 use html5ever::LocalName;
 use js::glue::UnwrapObject;
 use js::jsapi::{CallArgs, CurrentGlobalOrNull};
-use js::jsapi::{JSAutoCompartment, JSContext, JSObject};
+use js::jsapi::{JSAutoRealm, JSContext, JSObject};
 use js::rust::HandleObject;
 use js::rust::MutableHandleObject;
 use std::ptr;
@ -115,7 +115,7 @@ where
    }

    {
-        let _ac = JSAutoCompartment::new(window.get_cx(), callee.get());
+        let _ac = JSAutoRealm::new(window.get_cx(), callee.get());
        rooted!(in(window.get_cx()) let mut constructor = ptr::null_mut::<JSObject>());
        rooted!(in(window.get_cx()) let global_object = CurrentGlobalOrNull(window.get_cx()));

--- a/components/script/dom/bindings/interface.rs
+++ b/components/script/dom/bindings/interface.rs
@ -16,11 +16,9 @@ use js::error::throw_type_error;
 use js::glue::{UncheckedUnwrapObject, RUST_SYMBOL_TO_JSID};
 use js::jsapi::HandleObject as RawHandleObject;
 use js::jsapi::MutableHandleValue as RawMutableHandleValue;
-use js::jsapi::{Class, ClassOps, CompartmentOptions};
-use js::jsapi::{GetGlobalForObjectCrossCompartment, GetWellKnownSymbol};
-use js::jsapi::{
-    JSAutoCompartment, JSClass, JSContext, JSFunctionSpec, JSObject, JSFUN_CONSTRUCTOR,
-};
+use js::jsapi::{Class, ClassOps, RealmOptions};
+use js::jsapi::{GetNonCCWObjectGlobal, GetWellKnownSymbol};
+use js::jsapi::{JSAutoRealm, JSClass, JSContext, JSFunctionSpec, JSObject, JSFUN_CONSTRUCTOR};
 use js::jsapi::{JSPropertySpec, JSString, JSTracer, JS_AtomizeAndPinString};
 use js::jsapi::{JS_GetFunctionObject, JS_NewFunction, JS_NewGlobalObject};
 use js::jsapi::{JS_NewObject, JS_NewPlainObject};
@ -29,8 +27,8 @@ use js::jsapi::{ObjectOps, OnNewGlobalHookOption, SymbolCode};
 use js::jsapi::{TrueHandleValue, Value};
 use js::jsapi::{JSPROP_PERMANENT, JSPROP_READONLY, JSPROP_RESOLVING};
 use js::jsval::{JSVal, PrivateValue};
-use js::rust::wrappers::{JS_DefineProperty, JS_DefineProperty2};
-use js::rust::wrappers::{JS_DefineProperty3, JS_DefineProperty4, JS_DefinePropertyById4};
+use js::rust::wrappers::{JS_DefineProperty, JS_DefineProperty5};
+use js::rust::wrappers::{JS_DefineProperty3, JS_DefineProperty4, JS_DefinePropertyById5};
 use js::rust::wrappers::{JS_FireOnNewGlobalObject, JS_GetPrototype};
 use js::rust::wrappers::{JS_LinkConstructorAndPrototype, JS_NewObjectWithUniqueType};
 use js::rust::{define_methods, define_properties, get_object_class};
@ -138,7 +136,7 @@ pub unsafe fn create_global_object(
 ) {
    assert!(rval.is_null());

-    let mut options = CompartmentOptions::default();
+    let mut options = RealmOptions::default();
    options.creationOptions_.traceGlobal_ = Some(trace);
    options.creationOptions_.sharedMemoryAndAtomics_ = true;

@ -160,7 +158,7 @@ pub unsafe fn create_global_object(
    let val = PrivateValue(Box::into_raw(proto_array) as *const libc::c_void);
    JS_SetReservedSlot(rval.get(), DOM_PROTOTYPE_SLOT, &val);

-    let _ac = JSAutoCompartment::new(cx, rval.get());
+    let _ac = JSAutoRealm::new(cx, rval.get());
    JS_FireOnNewGlobalObject(cx, rval.handle());
 }

@ -209,7 +207,7 @@ pub unsafe fn create_interface_prototype_object(
        assert!(!unscopable_symbol.is_null());

        rooted!(in(cx) let unscopable_id = RUST_SYMBOL_TO_JSID(unscopable_symbol));
-        assert!(JS_DefinePropertyById4(
+        assert!(JS_DefinePropertyById5(
            cx,
            rval.handle(),
            unscopable_id.handle(),
@ -275,7 +273,7 @@ pub unsafe fn create_named_constructors(
        constructor.set(JS_GetFunctionObject(fun));
        assert!(!constructor.is_null());

-        assert!(JS_DefineProperty2(
+        assert!(JS_DefineProperty3(
            cx,
            constructor.handle(),
            b"prototype\0".as_ptr() as *const libc::c_char,
@ -360,7 +358,7 @@ pub unsafe fn define_on_global_object(
    obj: HandleObject,
 ) {
    assert_eq!(*name.last().unwrap(), b'\0');
-    assert!(JS_DefineProperty2(
+    assert!(JS_DefineProperty3(
        cx,
        global,
        name.as_ptr() as *const libc::c_char,
@ -442,7 +440,7 @@ unsafe fn has_instance(
    }

    // Step 2.
-    let global = GetGlobalForObjectCrossCompartment(interface_object.get());
+    let global = GetNonCCWObjectGlobal(interface_object.get());
    assert!(!global.is_null());
    let proto_or_iface_array = get_proto_or_iface_array(global);
    rooted!(in(cx) let prototype = (*proto_or_iface_array)[object_class.proto_id as usize]);
@ -488,7 +486,7 @@ unsafe fn define_name(cx: *mut JSContext, obj: HandleObject, name: &[u8]) {
    assert_eq!(*name.last().unwrap(), b'\0');
    rooted!(in(cx) let name = JS_AtomizeAndPinString(cx, name.as_ptr() as *const libc::c_char));
    assert!(!name.is_null());
-    assert!(JS_DefineProperty3(
+    assert!(JS_DefineProperty4(
        cx,
        obj,
        b"name\0".as_ptr() as *const libc::c_char,
@ -498,7 +496,7 @@ unsafe fn define_name(cx: *mut JSContext, obj: HandleObject, name: &[u8]) {
 }

 unsafe fn define_length(cx: *mut JSContext, obj: HandleObject, length: i32) {
-    assert!(JS_DefineProperty4(
+    assert!(JS_DefineProperty5(
        cx,
        obj,
        b"length\0".as_ptr() as *const libc::c_char,
--- a/components/script/dom/bindings/structuredclone.rs
+++ b/components/script/dom/bindings/structuredclone.rs
@ -22,7 +22,7 @@ use js::jsapi::MutableHandleObject as RawMutableHandleObject;
 use js::jsapi::StructuredCloneScope;
 use js::jsapi::TransferableOwnership;
 use js::jsapi::JS_STRUCTURED_CLONE_VERSION;
-use js::jsapi::{JSAutoCompartment, JSContext};
+use js::jsapi::{JSAutoRealm, JSContext};
 use js::jsapi::{JSObject, JS_ClearPendingException};
 use js::jsapi::{JSStructuredCloneCallbacks, JSStructuredCloneReader, JSStructuredCloneWriter};
 use js::jsapi::{JS_ReadBytes, JS_WriteBytes};
@ -220,6 +220,14 @@ unsafe extern "C" fn free_transfer_callback(
 ) {
 }

+unsafe extern "C" fn can_transfer_callback(
+    _cx: *mut JSContext,
+    _obj: RawHandleObject,
+    _closure: *mut raw::c_void,
+) -> bool {
+    false
+}
+
 unsafe extern "C" fn report_error_callback(_cx: *mut JSContext, _errorid: u32) {}

 static STRUCTURED_CLONE_CALLBACKS: JSStructuredCloneCallbacks = JSStructuredCloneCallbacks {
@ -229,6 +237,7 @@ static STRUCTURED_CLONE_CALLBACKS: JSStructuredCloneCallbacks = JSStructuredClon
    readTransfer: Some(read_transfer_callback),
    writeTransfer: Some(write_transfer_callback),
    freeTransfer: Some(free_transfer_callback),
+    canTransfer: Some(can_transfer_callback),
 };

 struct StructuredCloneHolder {
@ -299,7 +308,7 @@ impl StructuredCloneData {
    fn read_clone(global: &GlobalScope, data: *mut u64, nbytes: size_t, rval: MutableHandleValue) {
        let cx = global.get_cx();
        let globalhandle = global.reflector().get_jsobject();
-        let _ac = JSAutoCompartment::new(cx, globalhandle.get());
+        let _ac = JSAutoRealm::new(cx, globalhandle.get());
        let mut sc_holder = StructuredCloneHolder { blob: None };
        let sc_holder_ptr = &mut sc_holder as *mut _;
        unsafe {
--- a/components/script/dom/bindings/utils.rs
+++ b/components/script/dom/bindings/utils.rs
@ -20,8 +20,8 @@ use js::glue::{RUST_FUNCTION_VALUE_TO_JITINFO, RUST_JSID_IS_INT, RUST_JSID_IS_ST
 use js::jsapi::HandleId as RawHandleId;
 use js::jsapi::HandleObject as RawHandleObject;
 use js::jsapi::MutableHandleObject as RawMutableHandleObject;
-use js::jsapi::{CallArgs, DOMCallbacks, GetGlobalForObjectCrossCompartment};
-use js::jsapi::{Heap, JSAutoCompartment, JSContext};
+use js::jsapi::{CallArgs, DOMCallbacks, GetNonCCWObjectGlobal};
+use js::jsapi::{Heap, JSAutoRealm, JSContext};
 use js::jsapi::{JSJitInfo, JSObject, JSTracer, JSWrapObjectCallbacks};
 use js::jsapi::{JS_EnumerateStandardClasses, JS_GetLatin1StringCharsAndLength};
 use js::jsapi::{JS_IsExceptionPending, JS_IsGlobalObject};
@ -408,7 +408,7 @@ unsafe extern "C" fn pre_wrap(
    _object_passed_to_wrap: RawHandleObject,
    rval: RawMutableHandleObject,
 ) {
-    let _ac = JSAutoCompartment::new(cx, obj.get());
+    let _ac = JSAutoRealm::new(cx, obj.get());
    let obj = ToWindowProxyIfWindow(obj.get());
    assert!(!obj.is_null());
    rval.set(obj)
@ -455,12 +455,11 @@ unsafe fn generic_call(
        return false;
    }

-    let obj = if thisobj.get().is_object() {
+    rooted!(in(cx) let obj = if thisobj.get().is_object() {
        thisobj.get().to_object()
    } else {
-        GetGlobalForObjectCrossCompartment(JS_CALLEE(cx, vp).to_object_or_null())
-    };
-    rooted!(in(cx) let obj = obj);
+        GetNonCCWObjectGlobal(JS_CALLEE(cx, vp).to_object_or_null())
+    });
    let depth = (*info).depth;
    let proto_check =
        |class: &'static DOMClass| class.interface_chain[depth as usize] as u16 == proto_id;
--- a/components/script/dom/bluetooth.rs
+++ b/components/script/dom/bluetooth.rs
@ -116,7 +116,7 @@ where
    fn response(&mut self, response: BluetoothResponseResult) {
        let promise = self.promise.take().expect("bt promise is missing").root();

-        // JSAutoCompartment needs to be manually made.
+        // JSAutoRealm needs to be manually made.
        // Otherwise, Servo will crash.
        match response {
            Ok(response) => self.receiver.root().handle_response(response, &promise),
--- a/components/script/dom/create.rs
+++ b/components/script/dom/create.rs
@ -82,7 +82,7 @@ use crate::dom::htmlvideoelement::HTMLVideoElement;
 use crate::dom::svgsvgelement::SVGSVGElement;
 use crate::script_thread::ScriptThread;
 use html5ever::{LocalName, Prefix, QualName};
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use servo_config::pref;

 fn create_svg_element(
@ -156,10 +156,8 @@ fn create_html_element(

                            // Step 6.1.1
                            unsafe {
-                                let _ac = JSAutoCompartment::new(
-                                    cx,
-                                    global.reflector().get_jsobject().get(),
-                                );
+                                let _ac =
+                                    JSAutoRealm::new(cx, global.reflector().get_jsobject().get());
                                throw_dom_exception(cx, &global, error);
                                report_pending_exception(cx, true);
                            }
--- a/components/script/dom/customelementregistry.rs
+++ b/components/script/dom/customelementregistry.rs
@ -37,9 +37,9 @@ use html5ever::{LocalName, Namespace, Prefix};
 use js::conversions::ToJSValConvertible;
 use js::glue::UnwrapObject;
 use js::jsapi::{HandleValueArray, Heap, IsCallable, IsConstructor};
-use js::jsapi::{JSAutoCompartment, JSContext, JSObject};
+use js::jsapi::{JSAutoRealm, JSContext, JSObject};
 use js::jsval::{JSVal, NullValue, ObjectValue, UndefinedValue};
-use js::rust::wrappers::{Construct1, JS_GetProperty, JS_SameValue};
+use js::rust::wrappers::{Construct1, JS_GetProperty, SameValue};
 use js::rust::{HandleObject, HandleValue, MutableHandleValue};
 use std::cell::Cell;
 use std::collections::{HashMap, VecDeque};
@ -324,7 +324,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
        // Steps 10.1 - 10.2
        rooted!(in(cx) let mut prototype = UndefinedValue());
        {
-            let _ac = JSAutoCompartment::new(cx, constructor.get());
+            let _ac = JSAutoRealm::new(cx, constructor.get());
            if let Err(error) = self.check_prototype(constructor.handle(), prototype.handle_mut()) {
                self.element_definition_is_running.set(false);
                return Err(error);
@ -334,7 +334,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
        // Steps 10.3 - 10.4
        rooted!(in(cx) let proto_object = prototype.to_object());
        let callbacks = {
-            let _ac = JSAutoCompartment::new(cx, proto_object.get());
+            let _ac = JSAutoRealm::new(cx, proto_object.get());
            match unsafe { self.get_callbacks(proto_object.handle()) } {
                Ok(callbacks) => callbacks,
                Err(error) => {
@ -346,7 +346,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {

        // Step 10.5 - 10.6
        let observed_attributes = if callbacks.attribute_changed_callback.is_some() {
-            let _ac = JSAutoCompartment::new(cx, constructor.get());
+            let _ac = JSAutoRealm::new(cx, constructor.get());
            match self.get_observed_attributes(constructor.handle()) {
                Ok(attributes) => attributes,
                Err(error) => {
@ -535,7 +535,7 @@ impl CustomElementDefinition {
        rooted!(in(cx) let mut element = ptr::null_mut::<JSObject>());
        {
            // Go into the constructor's compartment
-            let _ac = JSAutoCompartment::new(cx, self.constructor.callback());
+            let _ac = JSAutoRealm::new(cx, self.constructor.callback());
            let args = HandleValueArray::new();
            if unsafe { !Construct1(cx, constructor.handle(), &args, element.handle_mut()) } {
                return Err(Error::JSFailed);
@ -665,7 +665,7 @@ fn run_upgrade_constructor(
    rooted!(in(cx) let mut construct_result = ptr::null_mut::<JSObject>());
    {
        // Go into the constructor's compartment
-        let _ac = JSAutoCompartment::new(cx, constructor.callback());
+        let _ac = JSAutoRealm::new(cx, constructor.callback());
        let args = HandleValueArray::new();
        // Step 7.1
        if unsafe {
@ -682,7 +682,7 @@ fn run_upgrade_constructor(
        let mut same = false;
        rooted!(in(cx) let construct_result_val = ObjectValue(construct_result.get()));
        if unsafe {
-            !JS_SameValue(
+            !SameValue(
                cx,
                construct_result_val.handle(),
                element_val.handle(),
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@ -33,7 +33,7 @@ use dom_struct::dom_struct;
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
 use ipc_channel::router::ROUTER;
 use js::jsapi::JS_AddInterruptCallback;
-use js::jsapi::{JSAutoCompartment, JSContext};
+use js::jsapi::{JSAutoRealm, JSContext};
 use js::jsval::UndefinedValue;
 use js::rust::HandleValue;
 use msg::constellation_msg::{PipelineId, TopLevelBrowsingContextId};
@ -433,8 +433,7 @@ impl DedicatedWorkerGlobalScope {
            WorkerScriptMsg::DOMMessage(data) => {
                let scope = self.upcast::<WorkerGlobalScope>();
                let target = self.upcast();
-                let _ac =
-                    JSAutoCompartment::new(scope.get_cx(), scope.reflector().get_jsobject().get());
+                let _ac = JSAutoRealm::new(scope.get_cx(), scope.reflector().get_jsobject().get());
                rooted!(in(scope.get_cx()) let mut message = UndefinedValue());
                data.read(scope.upcast(), message.handle_mut());
                MessageEvent::dispatch_jsval(target, scope.upcast(), message.handle(), None, None);
--- a/components/script/dom/eventsource.rs
+++ b/components/script/dom/eventsource.rs
@ -28,7 +28,7 @@ use http::header::{self, HeaderName, HeaderValue};
 use ipc_channel::ipc;
 use ipc_channel::router::ROUTER;
 use js::conversions::ToJSValConvertible;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use js::jsval::UndefinedValue;
 use mime::{self, Mime};
 use net_traits::request::{CacheMode, CorsSettings, CredentialsMode};
@ -222,7 +222,7 @@ impl EventSourceContext {
        };
        // Steps 4-5
        let event = {
-            let _ac = JSAutoCompartment::new(
+            let _ac = JSAutoRealm::new(
                event_source.global().get_cx(),
                event_source.reflector().get_jsobject().get(),
            );
--- a/components/script/dom/eventtarget.rs
+++ b/components/script/dom/eventtarget.rs
@ -34,10 +34,10 @@ use crate::dom::virtualmethods::VirtualMethods;
 use crate::dom::window::Window;
 use dom_struct::dom_struct;
 use fnv::FnvHasher;
-use js::jsapi::{JSAutoCompartment, JSFunction, JS_GetFunctionObject};
+use js::jsapi::{JSAutoRealm, JSFunction, JS_GetFunctionObject, SourceText};
 use js::rust::wrappers::CompileFunction;
 use js::rust::{AutoObjectVectorWrapper, CompileOptionsWrapper};
-use libc::{c_char, size_t};
+use libc::c_char;
 use servo_atoms::Atom;
 use servo_url::ServoUrl;
 use std::collections::hash_map::Entry::{Occupied, Vacant};
@ -45,6 +45,7 @@ use std::collections::HashMap;
 use std::default::Default;
 use std::ffi::CString;
 use std::hash::BuildHasherDefault;
+use std::marker::PhantomData;
 use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::ptr;
@ -505,7 +506,7 @@ impl EventTarget {

        let scopechain = AutoObjectVectorWrapper::new(cx);

-        let _ac = JSAutoCompartment::new(cx, window.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, window.reflector().get_jsobject().get());
        rooted!(in(cx) let mut handler = ptr::null_mut::<JSFunction>());
        let rv = unsafe {
            CompileFunction(
@ -515,15 +516,19 @@ impl EventTarget {
                name.as_ptr(),
                args.len() as u32,
                args.as_ptr(),
-                body.as_ptr(),
-                body.len() as size_t,
+                &mut SourceText {
+                    units_: body.as_ptr() as *const _,
+                    length_: body.len() as u32,
+                    ownsUnits_: false,
+                    _phantom_0: PhantomData,
+                },
                handler.handle_mut().into(),
            )
        };
        if !rv || handler.get().is_null() {
            // Step 1.8.2
            unsafe {
-                let _ac = JSAutoCompartment::new(cx, self.reflector().get_jsobject().get());
+                let _ac = JSAutoRealm::new(cx, self.reflector().get_jsobject().get());
                // FIXME(#13152): dispatch error event.
                report_pending_exception(cx, false);
            }
--- a/components/script/dom/filereader.rs
+++ b/components/script/dom/filereader.rs
@ -28,7 +28,7 @@ use base64;
 use dom_struct::dom_struct;
 use encoding_rs::{Encoding, UTF_8};
 use js::jsapi::Heap;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use js::jsapi::JSContext;
 use js::jsapi::JSObject;
 use js::jsval::{self, JSVal};
@ -262,8 +262,7 @@ impl FileReader {
                FileReader::perform_readastext(&fr.result, data, &blob_contents)
            },
            FileReaderFunction::ReadAsArrayBuffer => {
-                let _ac =
-                    JSAutoCompartment::new(fr.global().get_cx(), *fr.reflector().get_jsobject());
+                let _ac = JSAutoRealm::new(fr.global().get_cx(), *fr.reflector().get_jsobject());
                FileReader::perform_readasarraybuffer(
                    &fr.result,
                    fr.global().get_cx(),
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@ -42,11 +42,11 @@ use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
 use js::glue::{IsWrapper, UnwrapObject};
 use js::jsapi::JSObject;
-use js::jsapi::{CurrentGlobalOrNull, GetGlobalForObjectCrossCompartment};
+use js::jsapi::{CurrentGlobalOrNull, GetNonCCWObjectGlobal};
 use js::jsapi::{HandleObject, Heap};
-use js::jsapi::{JSAutoCompartment, JSContext};
+use js::jsapi::{JSAutoRealm, JSContext};
 use js::panic::maybe_resume_unwind;
-use js::rust::wrappers::Evaluate2;
+use js::rust::wrappers::EvaluateUtf8;
 use js::rust::{get_object_class, CompileOptionsWrapper, ParentRuntime, Runtime};
 use js::rust::{HandleValue, MutableHandleValue};
 use js::{JSCLASS_IS_DOMJSCLASS, JSCLASS_IS_GLOBAL};
@ -230,7 +230,7 @@ impl GlobalScope {
    #[allow(unsafe_code)]
    pub unsafe fn from_object(obj: *mut JSObject) -> DomRoot<Self> {
        assert!(!obj.is_null());
-        let global = GetGlobalForObjectCrossCompartment(obj);
+        let global = GetNonCCWObjectGlobal(obj);
        global_scope_from_global(global)
    }

@ -540,19 +540,18 @@ impl GlobalScope {
            || {
                let cx = self.get_cx();
                let globalhandle = self.reflector().get_jsobject();
-                let code: Vec<u16> = code.encode_utf16().collect();
                let filename = CString::new(filename).unwrap();

-                let _ac = JSAutoCompartment::new(cx, globalhandle.get());
+                let _ac = JSAutoRealm::new(cx, globalhandle.get());
                let _aes = AutoEntryScript::new(self);
                let options = CompileOptionsWrapper::new(cx, filename.as_ptr(), line_number);

                debug!("evaluating Dom string");
                let result = unsafe {
-                    Evaluate2(
+                    EvaluateUtf8(
                        cx,
                        options.ptr,
-                        code.as_ptr(),
+                        code.as_ptr() as *const _,
                        code.len() as libc::size_t,
                        rval,
                    )
--- a/components/script/dom/paintworkletglobalscope.rs
+++ b/components/script/dom/paintworkletglobalscope.rs
@ -31,7 +31,7 @@ use js::jsapi::HandleValueArray;
 use js::jsapi::Heap;
 use js::jsapi::IsCallable;
 use js::jsapi::IsConstructor;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use js::jsapi::JSObject;
 use js::jsapi::JS_ClearPendingException;
 use js::jsapi::JS_IsExceptionPending;
@ -252,7 +252,7 @@ impl PaintWorkletGlobalScope {
        );

        let cx = self.worklet_global.get_cx();
-        let _ac = JSAutoCompartment::new(cx, self.worklet_global.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, self.worklet_global.reflector().get_jsobject().get());

        // TODO: Steps 1-2.1.
        // Step 2.2-5.1.
--- a/components/script/dom/promise.rs
+++ b/components/script/dom/promise.rs
@ -22,7 +22,7 @@ use dom_struct::dom_struct;
 use js::conversions::ToJSValConvertible;
 use js::jsapi::{AddRawValueRoot, CallArgs, GetFunctionNativeReserved};
 use js::jsapi::{Heap, JS_ClearPendingException};
-use js::jsapi::{JSAutoCompartment, JSContext, JSObject, JS_GetFunctionObject};
+use js::jsapi::{JSAutoRealm, JSContext, JSObject, JS_GetFunctionObject};
 use js::jsapi::{JS_NewFunction, NewFunctionWithReserved, PromiseState};
 use js::jsapi::{RemoveRawValueRoot, SetFunctionNativeReserved};
 use js::jsval::{Int32Value, JSVal, ObjectValue, UndefinedValue};
@ -82,7 +82,7 @@ impl Drop for Promise {
 impl Promise {
    pub fn new(global: &GlobalScope) -> Rc<Promise> {
        let compartment =
-            JSAutoCompartment::new(global.get_cx(), global.reflector().get_jsobject().get());
+            JSAutoRealm::new(global.get_cx(), global.reflector().get_jsobject().get());
        let comp = InCompartment::Entered(&compartment);
        Promise::new_in_current_compartment(global, comp)
    }
@ -142,7 +142,7 @@ impl Promise {
        cx: *mut JSContext,
        value: HandleValue,
    ) -> Fallible<Rc<Promise>> {
-        let _ac = JSAutoCompartment::new(cx, global.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, global.reflector().get_jsobject().get());
        rooted!(in(cx) let p = CallOriginalPromiseResolve(cx, value));
        assert!(!p.handle().is_null());
        Ok(Promise::new_with_js_promise(p.handle(), cx))
@ -154,7 +154,7 @@ impl Promise {
        cx: *mut JSContext,
        value: HandleValue,
    ) -> Fallible<Rc<Promise>> {
-        let _ac = JSAutoCompartment::new(cx, global.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, global.reflector().get_jsobject().get());
        rooted!(in(cx) let p = CallOriginalPromiseReject(cx, value));
        assert!(!p.handle().is_null());
        Ok(Promise::new_with_js_promise(p.handle(), cx))
@ -166,7 +166,7 @@ impl Promise {
        T: ToJSValConvertible,
    {
        let cx = self.global().get_cx();
-        let _ac = JSAutoCompartment::new(cx, self.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, self.reflector().get_jsobject().get());
        rooted!(in(cx) let mut v = UndefinedValue());
        unsafe {
            val.to_jsval(cx, v.handle_mut());
@ -187,7 +187,7 @@ impl Promise {
        T: ToJSValConvertible,
    {
        let cx = self.global().get_cx();
-        let _ac = JSAutoCompartment::new(cx, self.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, self.reflector().get_jsobject().get());
        rooted!(in(cx) let mut v = UndefinedValue());
        unsafe {
            val.to_jsval(cx, v.handle_mut());
@ -198,7 +198,7 @@ impl Promise {
    #[allow(unsafe_code)]
    pub fn reject_error(&self, error: Error) {
        let cx = self.global().get_cx();
-        let _ac = JSAutoCompartment::new(cx, self.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, self.reflector().get_jsobject().get());
        rooted!(in(cx) let mut v = UndefinedValue());
        unsafe {
            error.to_jsval(cx, &self.global(), v.handle_mut());
--- a/components/script/dom/serviceworkerglobalscope.rs
+++ b/components/script/dom/serviceworkerglobalscope.rs
@ -28,7 +28,7 @@ use devtools_traits::DevtoolScriptControlMsg;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
 use ipc_channel::router::ROUTER;
-use js::jsapi::{JSAutoCompartment, JSContext, JS_AddInterruptCallback};
+use js::jsapi::{JSAutoRealm, JSContext, JS_AddInterruptCallback};
 use js::jsval::UndefinedValue;
 use msg::constellation_msg::PipelineId;
 use net_traits::request::{CredentialsMode, Destination, Referrer, RequestBuilder};
@ -406,8 +406,7 @@ impl ServiceWorkerGlobalScope {
            CommonWorker(WorkerScriptMsg::DOMMessage(data)) => {
                let scope = self.upcast::<WorkerGlobalScope>();
                let target = self.upcast();
-                let _ac =
-                    JSAutoCompartment::new(scope.get_cx(), scope.reflector().get_jsobject().get());
+                let _ac = JSAutoRealm::new(scope.get_cx(), scope.reflector().get_jsobject().get());
                rooted!(in(scope.get_cx()) let mut message = UndefinedValue());
                data.read(scope.upcast(), message.handle_mut());
                ExtendableMessageEvent::dispatch_jsval(target, scope.upcast(), message.handle());
--- a/components/script/dom/websocket.rs
+++ b/components/script/dom/websocket.rs
@ -27,7 +27,7 @@ use crate::task_source::websocket::WebsocketTaskSource;
 use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
-use js::jsapi::{JSAutoCompartment, JSObject};
+use js::jsapi::{JSAutoRealm, JSObject};
 use js::jsval::UndefinedValue;
 use js::rust::CustomAutoRooterGuard;
 use js::typedarray::{ArrayBuffer, ArrayBufferView, CreateWith};
@ -570,7 +570,7 @@ impl TaskOnce for MessageReceivedTask {
        // global.get_cx() returns a valid `JSContext` pointer, so this is safe.
        unsafe {
            let cx = global.get_cx();
-            let _ac = JSAutoCompartment::new(cx, ws.reflector().get_jsobject().get());
+            let _ac = JSAutoRealm::new(cx, ws.reflector().get_jsobject().get());
            rooted!(in(cx) let mut message = UndefinedValue());
            match self.message {
                MessageData::Text(text) => text.to_jsval(cx, message.handle_mut()),
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@ -76,10 +76,10 @@ use embedder_traits::EmbedderMsg;
 use euclid::{Point2D, Rect, Size2D, TypedPoint2D, TypedScale, TypedSize2D, Vector2D};
 use ipc_channel::ipc::{channel, IpcSender};
 use ipc_channel::router::ROUTER;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use js::jsapi::JSContext;
 use js::jsapi::JSPROP_ENUMERATE;
-use js::jsapi::JS_GC;
+use js::jsapi::{GCReason, JS_GC};
 use js::jsval::JSVal;
 use js::jsval::UndefinedValue;
 use js::rust::wrappers::JS_DefineProperty;
@ -901,7 +901,7 @@ impl WindowMethods for Window {
    #[allow(unsafe_code)]
    fn Gc(&self) {
        unsafe {
-            JS_GC(self.get_cx());
+            JS_GC(self.get_cx(), GCReason::API);
        }
    }

@ -2213,7 +2213,7 @@ impl Window {
            // Steps 7.2.-7.5.
            let cx = this.get_cx();
            let obj = this.reflector().get_jsobject();
-            let _ac = JSAutoCompartment::new(cx, obj.get());
+            let _ac = JSAutoRealm::new(cx, obj.get());
            rooted!(in(cx) let mut message_clone = UndefinedValue());
            serialize_with_transfer_result.read(
                this.upcast(),
--- a/components/script/dom/windowproxy.rs
+++ b/components/script/dom/windowproxy.rs
@ -31,7 +31,7 @@ use js::jsapi::HandleValue as RawHandleValue;
 use js::jsapi::MutableHandle as RawMutableHandle;
 use js::jsapi::MutableHandleObject as RawMutableHandleObject;
 use js::jsapi::MutableHandleValue as RawMutableHandleValue;
-use js::jsapi::{JSAutoCompartment, JSContext, JSErrNum, JSFreeOp, JSObject};
+use js::jsapi::{JSAutoRealm, JSContext, JSErrNum, JSFreeOp, JSObject};
 use js::jsapi::{JSTracer, JS_DefinePropertyById, JSPROP_ENUMERATE, JSPROP_READONLY};
 use js::jsapi::{JS_ForwardGetPropertyTo, JS_ForwardSetPropertyTo};
 use js::jsapi::{JS_GetOwnPropertyDescriptorById, JS_IsExceptionPending};
@ -148,7 +148,7 @@ impl WindowProxy {
                ((*get_object_class(window_jsobject.get())).flags & JSCLASS_IS_GLOBAL),
                0
            );
-            let _ac = JSAutoCompartment::new(cx, window_jsobject.get());
+            let _ac = JSAutoRealm::new(cx, window_jsobject.get());

            // Create a new window proxy.
            rooted!(in(cx) let js_proxy = NewWindowProxy(cx, window_jsobject, handler));
@ -219,7 +219,7 @@ impl WindowProxy {
                ((*get_object_class(window_jsobject.get())).flags & JSCLASS_IS_GLOBAL),
                0
            );
-            let _ac = JSAutoCompartment::new(cx, window_jsobject.get());
+            let _ac = JSAutoRealm::new(cx, window_jsobject.get());

            // Create a new window proxy.
            rooted!(in(cx) let js_proxy = NewWindowProxy(cx, window_jsobject, handler));
@ -548,7 +548,7 @@ impl WindowProxy {
                ((*get_object_class(window_jsobject.get())).flags & JSCLASS_IS_GLOBAL),
                0
            );
-            let _ac = JSAutoCompartment::new(cx, window_jsobject.get());
+            let _ac = JSAutoRealm::new(cx, window_jsobject.get());

            // The old window proxy no longer owns this browsing context.
            SetProxyReservedSlot(old_js_proxy.get(), 0, &PrivateValue(ptr::null_mut()));
--- a/components/script/dom/worker.rs
+++ b/components/script/dom/worker.rs
@ -25,7 +25,7 @@ use crossbeam_channel::{unbounded, Sender};
 use devtools_traits::{DevtoolsPageInfo, ScriptToDevtoolsControlMsg};
 use dom_struct::dom_struct;
 use ipc_channel::ipc;
-use js::jsapi::{JSAutoCompartment, JSContext, JS_RequestInterruptCallback};
+use js::jsapi::{JSAutoRealm, JSContext, JS_RequestInterruptCallback};
 use js::jsval::UndefinedValue;
 use js::rust::HandleValue;
 use script_traits::WorkerScriptLoadOrigin;
@ -137,7 +137,7 @@ impl Worker {

        let global = worker.global();
        let target = worker.upcast();
-        let _ac = JSAutoCompartment::new(global.get_cx(), target.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(global.get_cx(), target.reflector().get_jsobject().get());
        rooted!(in(global.get_cx()) let mut message = UndefinedValue());
        data.read(&global, message.handle_mut());
        MessageEvent::dispatch_jsval(target, &global, message.handle(), None, None);
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@ -37,7 +37,7 @@ use crossbeam_channel::Receiver;
 use devtools_traits::{DevtoolScriptControlMsg, WorkerId};
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
-use js::jsapi::{JSAutoCompartment, JSContext};
+use js::jsapi::{JSAutoRealm, JSContext};
 use js::jsval::UndefinedValue;
 use js::panic::maybe_resume_unwind;
 use js::rust::{HandleValue, ParentRuntime};
@ -401,7 +401,7 @@ impl WorkerGlobalScope {
                    // https://github.com/servo/servo/issues/6422
                    println!("evaluate_script failed");
                    unsafe {
-                        let _ac = JSAutoCompartment::new(
+                        let _ac = JSAutoRealm::new(
                            self.runtime.cx(),
                            self.reflector().get_jsobject().get(),
                        );
--- a/components/script/dom/worklet.rs
+++ b/components/script/dom/worklet.rs
@ -46,7 +46,7 @@ use dom_struct::dom_struct;
 use js::jsapi::JSGCParamKey;
 use js::jsapi::JSTracer;
 use js::jsapi::JS_GetGCParameter;
-use js::jsapi::JS_GC;
+use js::jsapi::{GCReason, JS_GC};
 use msg::constellation_msg::PipelineId;
 use net_traits::request::Destination;
 use net_traits::request::RequestBuilder;
@ -568,7 +568,7 @@ impl WorkletThread {
            self.current_memory_usage(),
            self.gc_threshold
        );
-        unsafe { JS_GC(self.runtime.cx()) };
+        unsafe { JS_GC(self.runtime.cx(), GCReason::API) };
        self.gc_threshold = max(MIN_GC_THRESHOLD, self.current_memory_usage() * 2);
        debug!(
            "END GC (usage = {}, threshold = {}).",
--- a/components/script/fetch.rs
+++ b/components/script/fetch.rs
@ -26,7 +26,7 @@ use crate::network_listener::{
 use crate::task_source::TaskSourceName;
 use ipc_channel::ipc;
 use ipc_channel::router::ROUTER;
-use js::jsapi::JSAutoCompartment;
+use js::jsapi::JSAutoRealm;
 use net_traits::request::RequestBuilder;
 use net_traits::request::{Request as NetTraitsRequest, ServiceWorkersMode};
 use net_traits::CoreResourceMsg::Fetch as NetTraitsFetch;
@ -210,10 +210,10 @@ impl FetchResponseListener for FetchContext {
            .expect("fetch promise is missing")
            .root();

-        // JSAutoCompartment needs to be manually made.
+        // JSAutoRealm needs to be manually made.
        // Otherwise, Servo will crash.
        let promise_cx = promise.global().get_cx();
-        let _ac = JSAutoCompartment::new(promise_cx, promise.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(promise_cx, promise.reflector().get_jsobject().get());
        match fetch_metadata {
            // Step 4.1
            Err(_) => {
@ -263,7 +263,7 @@ impl FetchResponseListener for FetchContext {
        let response = self.response_object.root();
        let global = response.global();
        let cx = global.get_cx();
-        let _ac = JSAutoCompartment::new(cx, global.reflector().get_jsobject().get());
+        let _ac = JSAutoRealm::new(cx, global.reflector().get_jsobject().get());
        response.finish(mem::replace(&mut self.body, vec![]));
        // TODO
        // ... trailerObject is not supported in Servo yet.
--- a/components/script/script_runtime.rs
+++ b/components/script/script_runtime.rs
@ -37,7 +37,9 @@ use js::jsapi::{
    JSJitCompilerOption, JS_SetOffthreadIonCompilationEnabled, JS_SetParallelParsingEnabled,
 };
 use js::jsapi::{JSObject, PromiseRejectionHandlingState, SetPreserveWrapperCallback};
-use js::jsapi::{SetBuildIdOp, SetEnqueuePromiseJobCallback, SetPromiseRejectionTrackerCallback};
+use js::jsapi::{
+    SetEnqueuePromiseJobCallback, SetProcessBuildIdOp, SetPromiseRejectionTrackerCallback,
+};
 use js::panic::wrap_panic;
 use js::rust::wrappers::{GetPromiseIsHandled, GetPromiseResult};
 use js::rust::Handle;
@ -137,15 +139,15 @@ pub trait ScriptPort {
 #[allow(unsafe_code)]
 unsafe extern "C" fn enqueue_job(
    cx: *mut JSContext,
+    _promise: HandleObject,
    job: HandleObject,
    _allocation_site: HandleObject,
-    _incumbent_global: HandleObject,
+    incumbent_global: HandleObject,
    _data: *mut c_void,
 ) -> bool {
    wrap_panic(
        AssertUnwindSafe(|| {
-            //XXXjdm - use a different global now?
-            let global = GlobalScope::from_object(job.get());
+            let global = GlobalScope::from_object(incumbent_global.get());
            let pipeline = global.pipeline_id();
            global.enqueue_microtask(Microtask::Promise(EnqueuedPromiseCallback {
                callback: PromiseJobCallback::new(cx, job.get()),
@ -360,7 +362,7 @@ unsafe fn new_rt_and_cx_with_parent(parent: Option<ParentRuntime>) -> Runtime {
        SetGCSliceCallback(cx, Some(gc_slice_callback));
    }

-    unsafe extern "C" fn empty_wrapper_callback(_: *mut JSContext, _: *mut JSObject) -> bool {
+    unsafe extern "C" fn empty_wrapper_callback(_: *mut JSContext, _: HandleObject) -> bool {
        true
    }
    SetDOMCallbacks(cx, &DOM_CALLBACKS);
@ -384,7 +386,7 @@ unsafe fn new_rt_and_cx_with_parent(parent: Option<ParentRuntime>) -> Runtime {
        // If WASM is enabled without setting the buildIdOp,
        // initializing a module will report an out of memory error.
        // https://dxr.mozilla.org/mozilla-central/source/js/src/wasm/WasmTypes.cpp#458
-        SetBuildIdOp(cx, Some(servo_build_id));
+        SetProcessBuildIdOp(Some(servo_build_id));
    }
    cx_opts.set_wasmBaseline_(pref!(js.wasm.baseline.enabled));
    cx_opts.set_wasmIon_(pref!(js.wasm.ion.enabled));
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@ -99,7 +99,7 @@ use hyper_serde::Serde;
 use ipc_channel::ipc::{self, IpcSender};
 use ipc_channel::router::ROUTER;
 use js::glue::GetWindowProxyClass;
-use js::jsapi::{JSAutoCompartment, JSContext, JS_SetWrapObjectCallbacks};
+use js::jsapi::{JSAutoRealm, JSContext, JS_SetWrapObjectCallbacks};
 use js::jsapi::{JSTracer, SetWindowProxyClass};
 use js::jsval::UndefinedValue;
 use js::rust::ParentRuntime;
@ -1971,7 +1971,7 @@ impl ScriptThread {
    fn handle_exit_fullscreen(&self, id: PipelineId) {
        let document = self.documents.borrow().find_document(id);
        if let Some(document) = document {
-            let _ac = JSAutoCompartment::new(
+            let _ac = JSAutoRealm::new(
                document.global().get_cx(),
                document.reflector().get_jsobject().get(),
            );
@ -3278,7 +3278,7 @@ impl ScriptThread {
        let script_source = percent_decode(encoded.as_bytes()).decode_utf8_lossy();

        // Script source is ready to be evaluated (11.)
-        let _ac = JSAutoCompartment::new(
+        let _ac = JSAutoRealm::new(
            global_scope.get_cx(),
            global_scope.reflector().get_jsobject().get(),
        );