deps: update V8 to 8.6.395

PR-URL: https://github.com/nodejs/node/pull/35415
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/deps/v8/src/builtins/weak-ref.tq b/deps/v8/src/builtins/weak-ref.tq
new file mode 100644
index 0000000000..18385e52db
--- /dev/null
+++ b/deps/v8/src/builtins/weak-ref.tq
@@ -0,0 +1,59 @@
+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+namespace runtime {
+
+extern runtime JSWeakRefAddToKeptObjects(implicit context: Context)(JSReceiver);
+
+}  // namespace runtime
+
+namespace weakref {
+
+transitioning javascript builtin
+WeakRefConstructor(
+    js-implicit context: NativeContext, receiver: JSAny, newTarget: JSAny,
+    target: JSFunction)(weakTarget: JSAny): JSWeakRef {
+  // 1. If NewTarget is undefined, throw a TypeError exception.
+  if (newTarget == Undefined) {
+    ThrowTypeError(MessageTemplate::kConstructorNotFunction, 'WeakRef');
+  }
+  // 2. If Type(target) is not Object, throw a TypeError exception.
+  const weakTarget = Cast<JSReceiver>(weakTarget) otherwise
+  ThrowTypeError(
+      MessageTemplate::kWeakRefsWeakRefConstructorTargetMustBeObject);
+  // 3. Let weakRef be ? OrdinaryCreateFromConstructor(NewTarget,
+  // "%WeakRefPrototype%", « [[WeakRefTarget]] »).
+  const map = GetDerivedMap(target, UnsafeCast<JSReceiver>(newTarget));
+  const weakRef = UnsafeCast<JSWeakRef>(AllocateFastOrSlowJSObjectFromMap(map));
+  // 4. Perfom ! AddToKeptObjects(target).
+  runtime::JSWeakRefAddToKeptObjects(weakTarget);
+  // 5. Set weakRef.[[WeakRefTarget]] to target.
+  weakRef.target = weakTarget;
+  // 6. Return weakRef.
+  return weakRef;
+}
+
+transitioning javascript builtin
+WeakRefDeref(js-implicit context: NativeContext, receiver: JSAny)(): JSAny {
+  // 1. Let weakRef be the this value.
+  // 2. Perform ? RequireInternalSlot(weakRef, [[WeakRefTarget]]).
+  const weakRef = Cast<JSWeakRef>(receiver) otherwise
+  ThrowTypeError(
+      MessageTemplate::kIncompatibleMethodReceiver, 'WeakRef.prototype.deref',
+      receiver);
+  // 3. Let target be the value of weakRef.[[WeakRefTarget]].
+  const target = weakRef.target;
+  // 4. If target is not empty,
+  //   a. Perform ! AddToKeptObjects(target).
+  //   b. Return target.
+  // 5. Return undefined.
+  if (target != Undefined) {
+    // JSWeakRefAddToKeptObjects might allocate and cause a GC, but it
+    // won't clear `target` since we hold it here on the stack.
+    runtime::JSWeakRefAddToKeptObjects(UnsafeCast<JSReceiver>(target));
+  }
+  return target;
+}
+
+}  // namespace weakrefs