Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1840 insertions, 0 deletions

diff --git a/js/src/builtin/MapObject.cpp b/js/src/builtin/MapObject.cpp
new file mode 100644
index 0000000000..f7a7807778
--- /dev/null
+++ b/js/src/builtin/MapObject.cpp
@@ -0,0 +1,1840 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "builtin/MapObject.h"
+
+#include "ds/OrderedHashTable.h"
+#include "gc/FreeOp.h"
+#include "js/PropertySpec.h"
+#include "js/Utility.h"
+#include "vm/BigIntType.h"
+#include "vm/EqualityOperations.h"  // js::SameValue
+#include "vm/GlobalObject.h"
+#include "vm/Interpreter.h"
+#include "vm/Iteration.h"
+#include "vm/JSContext.h"
+#include "vm/JSObject.h"
+#include "vm/SelfHosting.h"
+#include "vm/SymbolType.h"
+
+#include "gc/Marking-inl.h"
+#include "vm/Interpreter-inl.h"
+#include "vm/NativeObject-inl.h"
+
+using namespace js;
+
+using mozilla::IsNaN;
+using mozilla::NumberEqualsInt32;
+
+/*** HashableValue **********************************************************/
+
+bool HashableValue::setValue(JSContext* cx, HandleValue v) {
+  if (v.isString()) {
+    // Atomize so that hash() and operator==() are fast and infallible.
+    JSString* str = AtomizeString(cx, v.toString(), DoNotPinAtom);
+    if (!str) {
+      return false;
+    }
+    value = StringValue(str);
+  } else if (v.isDouble()) {
+    double d = v.toDouble();
+    int32_t i;
+    if (NumberEqualsInt32(d, &i)) {
+      // Normalize int32_t-valued doubles to int32_t for faster hashing and
+      // testing. Note: we use NumberEqualsInt32 here instead of NumberIsInt32
+      // because we want -0 and 0 to be normalized to the same thing.
+      value = Int32Value(i);
+    } else {
+      // Normalize the sign bit of a NaN.
+      value = JS::CanonicalizedDoubleValue(d);
+    }
+  } else {
+    value = v;
+  }
+
+  MOZ_ASSERT(value.isUndefined() || value.isNull() || value.isBoolean() ||
+             value.isNumber() || value.isString() || value.isSymbol() ||
+             value.isObject() || value.isBigInt());
+  return true;
+}
+
+static HashNumber HashValue(const Value& v,
+                            const mozilla::HashCodeScrambler& hcs) {
+  // HashableValue::setValue normalizes values so that the SameValue relation
+  // on HashableValues is the same as the == relationship on
+  // value.asRawBits(). So why not just return that? Security.
+  //
+  // To avoid revealing GC of atoms, string-based hash codes are computed
+  // from the string contents rather than any pointer; to avoid revealing
+  // addresses, pointer-based hash codes are computed using the
+  // HashCodeScrambler.
+
+  if (v.isString()) {
+    return v.toString()->asAtom().hash();
+  }
+  if (v.isSymbol()) {
+    return v.toSymbol()->hash();
+  }
+  if (v.isBigInt()) {
+    return MaybeForwarded(v.toBigInt())->hash();
+  }
+  if (v.isObject()) {
+    return hcs.scramble(v.asRawBits());
+  }
+
+  MOZ_ASSERT(!v.isGCThing(), "do not reveal pointers via hash codes");
+  return mozilla::HashGeneric(v.asRawBits());
+}
+
+HashNumber HashableValue::hash(const mozilla::HashCodeScrambler& hcs) const {
+  return HashValue(value, hcs);
+}
+
+bool HashableValue::operator==(const HashableValue& other) const {
+  // Two HashableValues are equal if they have equal bits.
+  bool b = (value.asRawBits() == other.value.asRawBits());
+
+  // BigInt values are considered equal if they represent the same
+  // mathematical value.
+  if (!b && (value.isBigInt() && other.value.isBigInt())) {
+    b = BigInt::equal(value.toBigInt(), other.value.toBigInt());
+  }
+
+#ifdef DEBUG
+  bool same;
+  JSContext* cx = TlsContext.get();
+  RootedValue valueRoot(cx, value);
+  RootedValue otherRoot(cx, other.value);
+  MOZ_ASSERT(SameValue(cx, valueRoot, otherRoot, &same));
+  MOZ_ASSERT(same == b);
+#endif
+  return b;
+}
+
+HashableValue HashableValue::trace(JSTracer* trc) const {
+  HashableValue hv(*this);
+  TraceEdge(trc, &hv.value, "key");
+  return hv;
+}
+
+/*** MapIterator ************************************************************/
+
+namespace {} /* anonymous namespace */
+
+static const JSClassOps MapIteratorObjectClassOps = {
+    nullptr,                      // addProperty
+    nullptr,                      // delProperty
+    nullptr,                      // enumerate
+    nullptr,                      // newEnumerate
+    nullptr,                      // resolve
+    nullptr,                      // mayResolve
+    MapIteratorObject::finalize,  // finalize
+    nullptr,                      // call
+    nullptr,                      // hasInstance
+    nullptr,                      // construct
+    nullptr,                      // trace
+};
+
+static const ClassExtension MapIteratorObjectClassExtension = {
+    MapIteratorObject::objectMoved,  // objectMovedOp
+};
+
+const JSClass MapIteratorObject::class_ = {
+    "Map Iterator",
+    JSCLASS_HAS_RESERVED_SLOTS(MapIteratorObject::SlotCount) |
+        JSCLASS_FOREGROUND_FINALIZE | JSCLASS_SKIP_NURSERY_FINALIZE,
+    &MapIteratorObjectClassOps, JS_NULL_CLASS_SPEC,
+    &MapIteratorObjectClassExtension};
+
+const JSFunctionSpec MapIteratorObject::methods[] = {
+    JS_SELF_HOSTED_FN("next", "MapIteratorNext", 0, 0), JS_FS_END};
+
+static inline ValueMap::Range* MapIteratorObjectRange(NativeObject* obj) {
+  MOZ_ASSERT(obj->is<MapIteratorObject>());
+  Value value = obj->getSlot(MapIteratorObject::RangeSlot);
+  if (value.isUndefined()) {
+    return nullptr;
+  }
+
+  return static_cast<ValueMap::Range*>(value.toPrivate());
+}
+
+inline MapObject::IteratorKind MapIteratorObject::kind() const {
+  int32_t i = getSlot(KindSlot).toInt32();
+  MOZ_ASSERT(i == MapObject::Keys || i == MapObject::Values ||
+             i == MapObject::Entries);
+  return MapObject::IteratorKind(i);
+}
+
+/* static */
+bool GlobalObject::initMapIteratorProto(JSContext* cx,
+                                        Handle<GlobalObject*> global) {
+  Rooted<JSObject*> base(
+      cx, GlobalObject::getOrCreateIteratorPrototype(cx, global));
+  if (!base) {
+    return false;
+  }
+  RootedPlainObject proto(
+      cx, GlobalObject::createBlankPrototypeInheriting<PlainObject>(cx, base));
+  if (!proto) {
+    return false;
+  }
+  if (!JS_DefineFunctions(cx, proto, MapIteratorObject::methods) ||
+      !DefineToStringTag(cx, proto, cx->names().MapIterator)) {
+    return false;
+  }
+  global->setReservedSlot(MAP_ITERATOR_PROTO, ObjectValue(*proto));
+  return true;
+}
+
+template <typename TableObject>
+static inline bool HasNurseryMemory(TableObject* t) {
+  return t->getReservedSlot(TableObject::HasNurseryMemorySlot).toBoolean();
+}
+
+template <typename TableObject>
+static inline void SetHasNurseryMemory(TableObject* t, bool b) {
+  t->setReservedSlot(TableObject::HasNurseryMemorySlot, JS::BooleanValue(b));
+}
+
+MapIteratorObject* MapIteratorObject::create(JSContext* cx, HandleObject obj,
+                                             ValueMap* data,
+                                             MapObject::IteratorKind kind) {
+  Handle<MapObject*> mapobj(obj.as<MapObject>());
+  Rooted<GlobalObject*> global(cx, &mapobj->global());
+  Rooted<JSObject*> proto(
+      cx, GlobalObject::getOrCreateMapIteratorPrototype(cx, global));
+  if (!proto) {
+    return nullptr;
+  }
+
+  MapIteratorObject* iterobj =
+      NewObjectWithGivenProto<MapIteratorObject>(cx, proto);
+  if (!iterobj) {
+    return nullptr;
+  }
+
+  iterobj->init(mapobj, kind);
+
+  constexpr size_t BufferSize =
+      RoundUp(sizeof(ValueMap::Range), gc::CellAlignBytes);
+
+  Nursery& nursery = cx->nursery();
+  void* buffer = nursery.allocateBufferSameLocation(iterobj, BufferSize);
+  if (!buffer) {
+    // Retry with |iterobj| and |buffer| forcibly tenured.
+    iterobj = NewTenuredObjectWithGivenProto<MapIteratorObject>(cx, proto);
+    if (!iterobj) {
+      return nullptr;
+    }
+
+    iterobj->init(mapobj, kind);
+
+    buffer = nursery.allocateBufferSameLocation(iterobj, BufferSize);
+    if (!buffer) {
+      ReportOutOfMemory(cx);
+      return nullptr;
+    }
+  }
+
+  bool insideNursery = IsInsideNursery(iterobj);
+  MOZ_ASSERT(insideNursery == nursery.isInside(buffer));
+
+  if (insideNursery && !HasNurseryMemory(mapobj.get())) {
+    if (!cx->nursery().addMapWithNurseryMemory(mapobj)) {
+      ReportOutOfMemory(cx);
+      return nullptr;
+    }
+    SetHasNurseryMemory(mapobj.get(), true);
+  }
+
+  auto range = data->createRange(buffer, insideNursery);
+  iterobj->setSlot(RangeSlot, PrivateValue(range));
+
+  return iterobj;
+}
+
+void MapIteratorObject::finalize(JSFreeOp* fop, JSObject* obj) {
+  MOZ_ASSERT(fop->onMainThread());
+  MOZ_ASSERT(!IsInsideNursery(obj));
+
+  auto range = MapIteratorObjectRange(&obj->as<NativeObject>());
+  MOZ_ASSERT(!fop->runtime()->gc.nursery().isInside(range));
+
+  // Bug 1560019: Malloc memory associated with MapIteratorObjects is not
+  // currently tracked.
+  fop->deleteUntracked(range);
+}
+
+size_t MapIteratorObject::objectMoved(JSObject* obj, JSObject* old) {
+  if (!IsInsideNursery(old)) {
+    return 0;
+  }
+
+  MapIteratorObject* iter = &obj->as<MapIteratorObject>();
+  ValueMap::Range* range = MapIteratorObjectRange(iter);
+  if (!range) {
+    return 0;
+  }
+
+  Nursery& nursery = iter->runtimeFromMainThread()->gc.nursery();
+  if (!nursery.isInside(range)) {
+    nursery.removeMallocedBufferDuringMinorGC(range);
+    return 0;
+  }
+
+  AutoEnterOOMUnsafeRegion oomUnsafe;
+  auto newRange = iter->zone()->new_<ValueMap::Range>(*range);
+  if (!newRange) {
+    oomUnsafe.crash(
+        "MapIteratorObject failed to allocate Range data while tenuring.");
+  }
+
+  range->~Range();
+  iter->setReservedSlot(MapIteratorObject::RangeSlot, PrivateValue(newRange));
+  return sizeof(ValueMap::Range);
+}
+
+template <typename Range>
+static void DestroyRange(JSObject* iterator, Range* range) {
+  range->~Range();
+  if (!IsInsideNursery(iterator)) {
+    js_free(range);
+  }
+}
+
+bool MapIteratorObject::next(MapIteratorObject* mapIterator,
+                             ArrayObject* resultPairObj) {
+  // IC code calls this directly.
+  AutoUnsafeCallWithABI unsafe;
+
+  // Check invariants for inlined _GetNextMapEntryForIterator.
+
+  // The array should be tenured, so that post-barrier can be done simply.
+  MOZ_ASSERT(resultPairObj->isTenured());
+
+  // The array elements should be fixed.
+  MOZ_ASSERT(resultPairObj->hasFixedElements());
+  MOZ_ASSERT(resultPairObj->getDenseInitializedLength() == 2);
+  MOZ_ASSERT(resultPairObj->getDenseCapacity() >= 2);
+
+  ValueMap::Range* range = MapIteratorObjectRange(mapIterator);
+  if (!range) {
+    return true;
+  }
+
+  if (range->empty()) {
+    DestroyRange<ValueMap::Range>(mapIterator, range);
+    mapIterator->setReservedSlot(RangeSlot, PrivateValue(nullptr));
+    return true;
+  }
+
+  switch (mapIterator->kind()) {
+    case MapObject::Keys:
+      resultPairObj->setDenseElement(0, range->front().key.get());
+      break;
+
+    case MapObject::Values:
+      resultPairObj->setDenseElement(1, range->front().value);
+      break;
+
+    case MapObject::Entries: {
+      resultPairObj->setDenseElement(0, range->front().key.get());
+      resultPairObj->setDenseElement(1, range->front().value);
+      break;
+    }
+  }
+  range->popFront();
+  return false;
+}
+
+/* static */
+JSObject* MapIteratorObject::createResultPair(JSContext* cx) {
+  RootedArrayObject resultPairObj(
+      cx, NewDenseFullyAllocatedArray(cx, 2, nullptr, TenuredObject));
+  if (!resultPairObj) {
+    return nullptr;
+  }
+
+  resultPairObj->setDenseInitializedLength(2);
+  resultPairObj->initDenseElement(0, NullValue());
+  resultPairObj->initDenseElement(1, NullValue());
+
+  return resultPairObj;
+}
+
+/*** Map ********************************************************************/
+
+const JSClassOps MapObject::classOps_ = {
+    nullptr,   // addProperty
+    nullptr,   // delProperty
+    nullptr,   // enumerate
+    nullptr,   // newEnumerate
+    nullptr,   // resolve
+    nullptr,   // mayResolve
+    finalize,  // finalize
+    nullptr,   // call
+    nullptr,   // hasInstance
+    nullptr,   // construct
+    trace,     // trace
+};
+
+const ClassSpec MapObject::classSpec_ = {
+    GenericCreateConstructor<MapObject::construct, 0, gc::AllocKind::FUNCTION>,
+    GenericCreatePrototype<MapObject>,
+    nullptr,
+    MapObject::staticProperties,
+    MapObject::methods,
+    MapObject::properties,
+    MapObject::finishInit};
+
+const JSClass MapObject::class_ = {
+    "Map",
+    JSCLASS_HAS_PRIVATE | JSCLASS_HAS_RESERVED_SLOTS(MapObject::SlotCount) |
+        JSCLASS_HAS_CACHED_PROTO(JSProto_Map) | JSCLASS_FOREGROUND_FINALIZE |
+        JSCLASS_SKIP_NURSERY_FINALIZE,
+    &MapObject::classOps_, &MapObject::classSpec_};
+
+const JSClass MapObject::protoClass_ = {
+    "Map.prototype", JSCLASS_HAS_CACHED_PROTO(JSProto_Map), JS_NULL_CLASS_OPS,
+    &MapObject::classSpec_};
+
+const JSPropertySpec MapObject::properties[] = {
+    JS_PSG("size", size, 0),
+    JS_STRING_SYM_PS(toStringTag, "Map", JSPROP_READONLY), JS_PS_END};
+
+// clang-format off
+const JSFunctionSpec MapObject::methods[] = {
+    JS_FN("get", get, 1, 0),
+    JS_FN("has", has, 1, 0),
+    JS_FN("set", set, 2, 0),
+    JS_FN("delete", delete_, 1, 0),
+    JS_FN("keys", keys, 0, 0),
+    JS_FN("values", values, 0, 0),
+    JS_FN("clear", clear, 0, 0),
+    JS_SELF_HOSTED_FN("forEach", "MapForEach", 2, 0),
+    JS_FN("entries", entries, 0, 0),
+    // @@iterator is re-defined in finishInit so that it has the
+    // same identity as |entries|.
+    JS_SYM_FN(iterator, entries, 0, 0),
+    JS_FS_END
+};
+// clang-format on
+
+const JSPropertySpec MapObject::staticProperties[] = {
+    JS_SELF_HOSTED_SYM_GET(species, "$MapSpecies", 0), JS_PS_END};
+
+/* static */ bool MapObject::finishInit(JSContext* cx, HandleObject ctor,
+                                        HandleObject proto) {
+  HandleNativeObject nativeProto = proto.as<NativeObject>();
+
+  RootedValue entriesFn(cx);
+  RootedId entriesId(cx, NameToId(cx->names().entries));
+  if (!NativeGetProperty(cx, nativeProto, entriesId, &entriesFn)) {
+    return false;
+  }
+
+  // 23.1.3.12 Map.prototype[@@iterator]()
+  // The initial value of the @@iterator property is the same function object
+  // as the initial value of the "entries" property.
+  RootedId iteratorId(
+      cx, SYMBOL_TO_JSID(JS::GetWellKnownSymbol(cx, JS::SymbolCode::iterator)));
+  return NativeDefineDataProperty(cx, nativeProto, iteratorId, entriesFn, 0);
+}
+
+template <class Range>
+static void TraceKey(Range& r, const HashableValue& key, JSTracer* trc) {
+  HashableValue newKey = key.trace(trc);
+
+  if (newKey.get() != key.get()) {
+    // The hash function must take account of the fact that the thing being
+    // hashed may have been moved by GC. This is only an issue for BigInt as for
+    // other types the hash function only uses the bits of the Value.
+    r.rekeyFront(newKey);
+  }
+
+  // Clear newKey to avoid the barrier in ~PreBarriered.
+  newKey.unbarrieredClear();
+}
+
+void MapObject::trace(JSTracer* trc, JSObject* obj) {
+  if (ValueMap* map = obj->as<MapObject>().getData()) {
+    for (ValueMap::Range r = map->all(); !r.empty(); r.popFront()) {
+      TraceKey(r, r.front().key, trc);
+      TraceEdge(trc, &r.front().value, "value");
+    }
+  }
+}
+
+struct js::UnbarrieredHashPolicy {
+  using Lookup = Value;
+  static HashNumber hash(const Lookup& v,
+                         const mozilla::HashCodeScrambler& hcs) {
+    return HashValue(v, hcs);
+  }
+  static bool match(const Value& k, const Lookup& l) { return k == l; }
+  static bool isEmpty(const Value& v) { return v.isMagic(JS_HASH_KEY_EMPTY); }
+  static void makeEmpty(Value* vp) { vp->setMagic(JS_HASH_KEY_EMPTY); }
+};
+
+using NurseryKeysVector = mozilla::Vector<Value, 0, SystemAllocPolicy>;
+
+template <typename TableObject>
+static NurseryKeysVector* GetNurseryKeys(TableObject* t) {
+  Value value = t->getReservedSlot(TableObject::NurseryKeysSlot);
+  return reinterpret_cast<NurseryKeysVector*>(value.toPrivate());
+}
+
+template <typename TableObject>
+static NurseryKeysVector* AllocNurseryKeys(TableObject* t) {
+  MOZ_ASSERT(!GetNurseryKeys(t));
+  auto keys = js_new<NurseryKeysVector>();
+  if (!keys) {
+    return nullptr;
+  }
+
+  t->setReservedSlot(TableObject::NurseryKeysSlot, PrivateValue(keys));
+  return keys;
+}
+
+template <typename TableObject>
+static void DeleteNurseryKeys(TableObject* t) {
+  auto keys = GetNurseryKeys(t);
+  MOZ_ASSERT(keys);
+  js_delete(keys);
+  t->setReservedSlot(TableObject::NurseryKeysSlot, PrivateValue(nullptr));
+}
+
+// A generic store buffer entry that traces all nursery keys for an ordered hash
+// map or set.
+template <typename ObjectT>
+class js::OrderedHashTableRef : public gc::BufferableRef {
+  ObjectT* object;
+
+ public:
+  explicit OrderedHashTableRef(ObjectT* obj) : object(obj) {}
+
+  void trace(JSTracer* trc) override {
+    MOZ_ASSERT(!IsInsideNursery(object));
+    auto realTable = object->getData();
+    auto unbarrieredTable =
+        reinterpret_cast<typename ObjectT::UnbarrieredTable*>(realTable);
+    NurseryKeysVector* keys = GetNurseryKeys(object);
+    MOZ_ASSERT(keys);
+    for (Value& key : *keys) {
+      Value prior = key;
+      MOZ_ASSERT(unbarrieredTable->hash(key) ==
+                 realTable->hash(*reinterpret_cast<HashableValue*>(&key)));
+      TraceManuallyBarrieredEdge(trc, &key, "ordered hash table key");
+      unbarrieredTable->rekeyOneEntry(prior, key);
+    }
+    DeleteNurseryKeys(object);
+  }
+};
+
+template <typename ObjectT>
+inline static MOZ_MUST_USE bool PostWriteBarrierImpl(ObjectT* obj,
+                                                     const Value& keyValue) {
+  if (MOZ_LIKELY(!keyValue.isObject() && !keyValue.isBigInt())) {
+    MOZ_ASSERT_IF(keyValue.isGCThing(), !IsInsideNursery(keyValue.toGCThing()));
+    return true;
+  }
+
+  if (IsInsideNursery(obj)) {
+    return true;
+  }
+
+  if (!IsInsideNursery(keyValue.toGCThing())) {
+    return true;
+  }
+
+  NurseryKeysVector* keys = GetNurseryKeys(obj);
+  if (!keys) {
+    keys = AllocNurseryKeys(obj);
+    if (!keys) {
+      return false;
+    }
+
+    keyValue.toGCThing()->storeBuffer()->putGeneric(
+        OrderedHashTableRef<ObjectT>(obj));
+  }
+
+  return keys->append(keyValue);
+}
+
+inline static MOZ_MUST_USE bool PostWriteBarrier(MapObject* map,
+                                                 const Value& key) {
+  return PostWriteBarrierImpl(map, key);
+}
+
+inline static MOZ_MUST_USE bool PostWriteBarrier(SetObject* set,
+                                                 const Value& key) {
+  return PostWriteBarrierImpl(set, key);
+}
+
+bool MapObject::getKeysAndValuesInterleaved(
+    HandleObject obj, JS::MutableHandle<GCVector<JS::Value>> entries) {
+  ValueMap* map = obj->as<MapObject>().getData();
+  if (!map) {
+    return false;
+  }
+
+  for (ValueMap::Range r = map->all(); !r.empty(); r.popFront()) {
+    if (!entries.append(r.front().key.get()) ||
+        !entries.append(r.front().value)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool MapObject::set(JSContext* cx, HandleObject obj, HandleValue k,
+                    HandleValue v) {
+  ValueMap* map = obj->as<MapObject>().getData();
+  if (!map) {
+    return false;
+  }
+
+  Rooted<HashableValue> key(cx);
+  if (!key.setValue(cx, k)) {
+    return false;
+  }
+
+  if (!PostWriteBarrier(&obj->as<MapObject>(), key.value()) ||
+      !map->put(key, v)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+
+  return true;
+}
+
+MapObject* MapObject::create(JSContext* cx,
+                             HandleObject proto /* = nullptr */) {
+  auto map = cx->make_unique<ValueMap>(cx->zone(),
+                                       cx->realm()->randomHashCodeScrambler());
+  if (!map) {
+    return nullptr;
+  }
+
+  if (!map->init()) {
+    ReportOutOfMemory(cx);
+    return nullptr;
+  }
+
+  MapObject* mapObj = NewObjectWithClassProto<MapObject>(cx, proto);
+  if (!mapObj) {
+    return nullptr;
+  }
+
+  bool insideNursery = IsInsideNursery(mapObj);
+  if (insideNursery && !cx->nursery().addMapWithNurseryMemory(mapObj)) {
+    ReportOutOfMemory(cx);
+    return nullptr;
+  }
+
+  InitObjectPrivate(mapObj, map.release(), MemoryUse::MapObjectTable);
+  mapObj->initReservedSlot(NurseryKeysSlot, PrivateValue(nullptr));
+  mapObj->initReservedSlot(HasNurseryMemorySlot,
+                           JS::BooleanValue(insideNursery));
+  return mapObj;
+}
+
+void MapObject::finalize(JSFreeOp* fop, JSObject* obj) {
+  MOZ_ASSERT(fop->onMainThread());
+  if (ValueMap* map = obj->as<MapObject>().getData()) {
+    fop->delete_(obj, map, MemoryUse::MapObjectTable);
+  }
+}
+
+/* static */
+void MapObject::sweepAfterMinorGC(JSFreeOp* fop, MapObject* mapobj) {
+  bool wasInsideNursery = IsInsideNursery(mapobj);
+  if (wasInsideNursery && !IsForwarded(mapobj)) {
+    finalize(fop, mapobj);
+    return;
+  }
+
+  mapobj = MaybeForwarded(mapobj);
+  mapobj->getData()->destroyNurseryRanges();
+  SetHasNurseryMemory(mapobj, false);
+
+  if (wasInsideNursery) {
+    AddCellMemory(mapobj, sizeof(ValueMap), MemoryUse::MapObjectTable);
+  }
+}
+
+bool MapObject::construct(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (!ThrowIfNotConstructing(cx, args, "Map")) {
+    return false;
+  }
+
+  RootedObject proto(cx);
+  if (!GetPrototypeFromBuiltinConstructor(cx, args, JSProto_Map, &proto)) {
+    return false;
+  }
+
+  Rooted<MapObject*> obj(cx, MapObject::create(cx, proto));
+  if (!obj) {
+    return false;
+  }
+
+  if (!args.get(0).isNullOrUndefined()) {
+    FixedInvokeArgs<1> args2(cx);
+    args2[0].set(args[0]);
+
+    RootedValue thisv(cx, ObjectValue(*obj));
+    if (!CallSelfHostedFunction(cx, cx->names().MapConstructorInit, thisv,
+                                args2, args2.rval())) {
+      return false;
+    }
+  }
+
+  args.rval().setObject(*obj);
+  return true;
+}
+
+bool MapObject::is(HandleValue v) {
+  return v.isObject() && v.toObject().hasClass(&class_) &&
+         v.toObject().as<MapObject>().getPrivate();
+}
+
+bool MapObject::is(HandleObject o) {
+  return o->hasClass(&class_) && o->as<MapObject>().getPrivate();
+}
+
+#define ARG0_KEY(cx, args, key)  \
+  Rooted<HashableValue> key(cx); \
+  if (args.length() > 0 && !key.setValue(cx, args[0])) return false
+
+ValueMap& MapObject::extract(HandleObject o) {
+  MOZ_ASSERT(o->hasClass(&MapObject::class_));
+  return *o->as<MapObject>().getData();
+}
+
+ValueMap& MapObject::extract(const CallArgs& args) {
+  MOZ_ASSERT(args.thisv().isObject());
+  MOZ_ASSERT(args.thisv().toObject().hasClass(&MapObject::class_));
+  return *args.thisv().toObject().as<MapObject>().getData();
+}
+
+uint32_t MapObject::size(JSContext* cx, HandleObject obj) {
+  ValueMap& map = extract(obj);
+  static_assert(sizeof(map.count()) <= sizeof(uint32_t),
+                "map count must be precisely representable as a JS number");
+  return map.count();
+}
+
+bool MapObject::size_impl(JSContext* cx, const CallArgs& args) {
+  RootedObject obj(cx, &args.thisv().toObject());
+  args.rval().setNumber(size(cx, obj));
+  return true;
+}
+
+bool MapObject::size(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<MapObject::is, MapObject::size_impl>(cx, args);
+}
+
+bool MapObject::get(JSContext* cx, HandleObject obj, HandleValue key,
+                    MutableHandleValue rval) {
+  ValueMap& map = extract(obj);
+  Rooted<HashableValue> k(cx);
+
+  if (!k.setValue(cx, key)) {
+    return false;
+  }
+
+  if (ValueMap::Entry* p = map.get(k)) {
+    rval.set(p->value);
+  } else {
+    rval.setUndefined();
+  }
+
+  return true;
+}
+
+bool MapObject::get_impl(JSContext* cx, const CallArgs& args) {
+  RootedObject obj(cx, &args.thisv().toObject());
+  return get(cx, obj, args.get(0), args.rval());
+}
+
+bool MapObject::get(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<MapObject::is, MapObject::get_impl>(cx, args);
+}
+
+bool MapObject::has(JSContext* cx, HandleObject obj, HandleValue key,
+                    bool* rval) {
+  ValueMap& map = extract(obj);
+  Rooted<HashableValue> k(cx);
+
+  if (!k.setValue(cx, key)) {
+    return false;
+  }
+
+  *rval = map.has(k);
+  return true;
+}
+
+bool MapObject::has_impl(JSContext* cx, const CallArgs& args) {
+  bool found;
+  RootedObject obj(cx, &args.thisv().toObject());
+  if (has(cx, obj, args.get(0), &found)) {
+    args.rval().setBoolean(found);
+    return true;
+  }
+  return false;
+}
+
+bool MapObject::has(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<MapObject::is, MapObject::has_impl>(cx, args);
+}
+
+bool MapObject::set_impl(JSContext* cx, const CallArgs& args) {
+  MOZ_ASSERT(MapObject::is(args.thisv()));
+
+  ValueMap& map = extract(args);
+  ARG0_KEY(cx, args, key);
+  if (!PostWriteBarrier(&args.thisv().toObject().as<MapObject>(),
+                        key.value()) ||
+      !map.put(key, args.get(1))) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+
+  args.rval().set(args.thisv());
+  return true;
+}
+
+bool MapObject::set(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<MapObject::is, MapObject::set_impl>(cx, args);
+}
+
+bool MapObject::delete_(JSContext* cx, HandleObject obj, HandleValue key,
+                        bool* rval) {
+  ValueMap& map = extract(obj);
+  Rooted<HashableValue> k(cx);
+
+  if (!k.setValue(cx, key)) {
+    return false;
+  }
+
+  if (!map.remove(k, rval)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  return true;
+}
+
+bool MapObject::delete_impl(JSContext* cx, const CallArgs& args) {
+  // MapObject::trace does not trace deleted entries. Incremental GC therefore
+  // requires that no HeapPtr<Value> objects pointing to heap values be left
+  // alive in the ValueMap.
+  //
+  // OrderedHashMap::remove() doesn't destroy the removed entry. It merely
+  // calls OrderedHashMap::MapOps::makeEmpty. But that is sufficient, because
+  // makeEmpty clears the value by doing e->value = Value(), and in the case
+  // of a ValueMap, Value() means HeapPtr<Value>(), which is the same as
+  // HeapPtr<Value>(UndefinedValue()).
+  MOZ_ASSERT(MapObject::is(args.thisv()));
+
+  ValueMap& map = extract(args);
+  ARG0_KEY(cx, args, key);
+  bool found;
+  if (!map.remove(key, &found)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  args.rval().setBoolean(found);
+  return true;
+}
+
+bool MapObject::delete_(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<MapObject::is, MapObject::delete_impl>(cx, args);
+}
+
+bool MapObject::iterator(JSContext* cx, IteratorKind kind, HandleObject obj,
+                         MutableHandleValue iter) {
+  ValueMap& map = extract(obj);
+  Rooted<JSObject*> iterobj(cx, MapIteratorObject::create(cx, obj, &map, kind));
+  if (!iterobj) {
+    return false;
+  }
+  iter.setObject(*iterobj);
+  return true;
+}
+
+bool MapObject::iterator_impl(JSContext* cx, const CallArgs& args,
+                              IteratorKind kind) {
+  RootedObject obj(cx, &args.thisv().toObject());
+  return iterator(cx, kind, obj, args.rval());
+}
+
+bool MapObject::keys_impl(JSContext* cx, const CallArgs& args) {
+  return iterator_impl(cx, args, Keys);
+}
+
+bool MapObject::keys(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, keys_impl, args);
+}
+
+bool MapObject::values_impl(JSContext* cx, const CallArgs& args) {
+  return iterator_impl(cx, args, Values);
+}
+
+bool MapObject::values(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, values_impl, args);
+}
+
+bool MapObject::entries_impl(JSContext* cx, const CallArgs& args) {
+  return iterator_impl(cx, args, Entries);
+}
+
+bool MapObject::entries(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, entries_impl, args);
+}
+
+bool MapObject::clear_impl(JSContext* cx, const CallArgs& args) {
+  RootedObject obj(cx, &args.thisv().toObject());
+  args.rval().setUndefined();
+  return clear(cx, obj);
+}
+
+bool MapObject::clear(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, clear_impl, args);
+}
+
+bool MapObject::clear(JSContext* cx, HandleObject obj) {
+  ValueMap& map = extract(obj);
+  if (!map.clear()) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  return true;
+}
+
+/*** SetIterator ************************************************************/
+
+static const JSClassOps SetIteratorObjectClassOps = {
+    nullptr,                      // addProperty
+    nullptr,                      // delProperty
+    nullptr,                      // enumerate
+    nullptr,                      // newEnumerate
+    nullptr,                      // resolve
+    nullptr,                      // mayResolve
+    SetIteratorObject::finalize,  // finalize
+    nullptr,                      // call
+    nullptr,                      // hasInstance
+    nullptr,                      // construct
+    nullptr,                      // trace
+};
+
+static const ClassExtension SetIteratorObjectClassExtension = {
+    SetIteratorObject::objectMoved,  // objectMovedOp
+};
+
+const JSClass SetIteratorObject::class_ = {
+    "Set Iterator",
+    JSCLASS_HAS_RESERVED_SLOTS(SetIteratorObject::SlotCount) |
+        JSCLASS_FOREGROUND_FINALIZE | JSCLASS_SKIP_NURSERY_FINALIZE,
+    &SetIteratorObjectClassOps, JS_NULL_CLASS_SPEC,
+    &SetIteratorObjectClassExtension};
+
+const JSFunctionSpec SetIteratorObject::methods[] = {
+    JS_SELF_HOSTED_FN("next", "SetIteratorNext", 0, 0), JS_FS_END};
+
+static inline ValueSet::Range* SetIteratorObjectRange(NativeObject* obj) {
+  MOZ_ASSERT(obj->is<SetIteratorObject>());
+  Value value = obj->getSlot(SetIteratorObject::RangeSlot);
+  if (value.isUndefined()) {
+    return nullptr;
+  }
+
+  return static_cast<ValueSet::Range*>(value.toPrivate());
+}
+
+inline SetObject::IteratorKind SetIteratorObject::kind() const {
+  int32_t i = getSlot(KindSlot).toInt32();
+  MOZ_ASSERT(i == SetObject::Values || i == SetObject::Entries);
+  return SetObject::IteratorKind(i);
+}
+
+/* static */
+bool GlobalObject::initSetIteratorProto(JSContext* cx,
+                                        Handle<GlobalObject*> global) {
+  Rooted<JSObject*> base(
+      cx, GlobalObject::getOrCreateIteratorPrototype(cx, global));
+  if (!base) {
+    return false;
+  }
+  RootedPlainObject proto(
+      cx, GlobalObject::createBlankPrototypeInheriting<PlainObject>(cx, base));
+  if (!proto) {
+    return false;
+  }
+  if (!JS_DefineFunctions(cx, proto, SetIteratorObject::methods) ||
+      !DefineToStringTag(cx, proto, cx->names().SetIterator)) {
+    return false;
+  }
+  global->setReservedSlot(SET_ITERATOR_PROTO, ObjectValue(*proto));
+  return true;
+}
+
+SetIteratorObject* SetIteratorObject::create(JSContext* cx, HandleObject obj,
+                                             ValueSet* data,
+                                             SetObject::IteratorKind kind) {
+  MOZ_ASSERT(kind != SetObject::Keys);
+
+  Handle<SetObject*> setobj(obj.as<SetObject>());
+  Rooted<GlobalObject*> global(cx, &setobj->global());
+  Rooted<JSObject*> proto(
+      cx, GlobalObject::getOrCreateSetIteratorPrototype(cx, global));
+  if (!proto) {
+    return nullptr;
+  }
+
+  SetIteratorObject* iterobj =
+      NewObjectWithGivenProto<SetIteratorObject>(cx, proto);
+  if (!iterobj) {
+    return nullptr;
+  }
+
+  iterobj->init(setobj, kind);
+
+  constexpr size_t BufferSize =
+      RoundUp(sizeof(ValueSet::Range), gc::CellAlignBytes);
+
+  Nursery& nursery = cx->nursery();
+  void* buffer = nursery.allocateBufferSameLocation(iterobj, BufferSize);
+  if (!buffer) {
+    // Retry with |iterobj| and |buffer| forcibly tenured.
+    iterobj = NewTenuredObjectWithGivenProto<SetIteratorObject>(cx, proto);
+    if (!iterobj) {
+      return nullptr;
+    }
+
+    iterobj->init(setobj, kind);
+
+    buffer = nursery.allocateBufferSameLocation(iterobj, BufferSize);
+    if (!buffer) {
+      ReportOutOfMemory(cx);
+      return nullptr;
+    }
+  }
+
+  bool insideNursery = IsInsideNursery(iterobj);
+  MOZ_ASSERT(insideNursery == nursery.isInside(buffer));
+
+  if (insideNursery && !HasNurseryMemory(setobj.get())) {
+    if (!cx->nursery().addSetWithNurseryMemory(setobj)) {
+      ReportOutOfMemory(cx);
+      return nullptr;
+    }
+    SetHasNurseryMemory(setobj.get(), true);
+  }
+
+  auto range = data->createRange(buffer, insideNursery);
+  iterobj->setSlot(RangeSlot, PrivateValue(range));
+
+  return iterobj;
+}
+
+void SetIteratorObject::finalize(JSFreeOp* fop, JSObject* obj) {
+  MOZ_ASSERT(fop->onMainThread());
+  MOZ_ASSERT(!IsInsideNursery(obj));
+
+  auto range = SetIteratorObjectRange(&obj->as<NativeObject>());
+  MOZ_ASSERT(!fop->runtime()->gc.nursery().isInside(range));
+
+  // Bug 1560019: Malloc memory associated with SetIteratorObjects is not
+  // currently tracked.
+  fop->deleteUntracked(range);
+}
+
+size_t SetIteratorObject::objectMoved(JSObject* obj, JSObject* old) {
+  if (!IsInsideNursery(old)) {
+    return 0;
+  }
+
+  SetIteratorObject* iter = &obj->as<SetIteratorObject>();
+  ValueSet::Range* range = SetIteratorObjectRange(iter);
+  if (!range) {
+    return 0;
+  }
+
+  Nursery& nursery = iter->runtimeFromMainThread()->gc.nursery();
+  if (!nursery.isInside(range)) {
+    nursery.removeMallocedBufferDuringMinorGC(range);
+    return 0;
+  }
+
+  AutoEnterOOMUnsafeRegion oomUnsafe;
+  auto newRange = iter->zone()->new_<ValueSet::Range>(*range);
+  if (!newRange) {
+    oomUnsafe.crash(
+        "SetIteratorObject failed to allocate Range data while tenuring.");
+  }
+
+  range->~Range();
+  iter->setReservedSlot(SetIteratorObject::RangeSlot, PrivateValue(newRange));
+  return sizeof(ValueSet::Range);
+}
+
+bool SetIteratorObject::next(SetIteratorObject* setIterator,
+                             ArrayObject* resultObj) {
+  // IC code calls this directly.
+  AutoUnsafeCallWithABI unsafe;
+
+  // Check invariants for inlined _GetNextSetEntryForIterator.
+
+  // The array should be tenured, so that post-barrier can be done simply.
+  MOZ_ASSERT(resultObj->isTenured());
+
+  // The array elements should be fixed.
+  MOZ_ASSERT(resultObj->hasFixedElements());
+  MOZ_ASSERT(resultObj->getDenseInitializedLength() == 1);
+  MOZ_ASSERT(resultObj->getDenseCapacity() >= 1);
+
+  ValueSet::Range* range = SetIteratorObjectRange(setIterator);
+  if (!range) {
+    return true;
+  }
+
+  if (range->empty()) {
+    DestroyRange<ValueSet::Range>(setIterator, range);
+    setIterator->setReservedSlot(RangeSlot, PrivateValue(nullptr));
+    return true;
+  }
+
+  resultObj->setDenseElement(0, range->front().get());
+  range->popFront();
+  return false;
+}
+
+/* static */
+JSObject* SetIteratorObject::createResult(JSContext* cx) {
+  RootedArrayObject resultObj(
+      cx, NewDenseFullyAllocatedArray(cx, 1, nullptr, TenuredObject));
+  if (!resultObj) {
+    return nullptr;
+  }
+
+  resultObj->setDenseInitializedLength(1);
+  resultObj->initDenseElement(0, NullValue());
+
+  return resultObj;
+}
+
+/*** Set ********************************************************************/
+
+const JSClassOps SetObject::classOps_ = {
+    nullptr,   // addProperty
+    nullptr,   // delProperty
+    nullptr,   // enumerate
+    nullptr,   // newEnumerate
+    nullptr,   // resolve
+    nullptr,   // mayResolve
+    finalize,  // finalize
+    nullptr,   // call
+    nullptr,   // hasInstance
+    nullptr,   // construct
+    trace,     // trace
+};
+
+const ClassSpec SetObject::classSpec_ = {
+    GenericCreateConstructor<SetObject::construct, 0, gc::AllocKind::FUNCTION>,
+    GenericCreatePrototype<SetObject>,
+    nullptr,
+    SetObject::staticProperties,
+    SetObject::methods,
+    SetObject::properties,
+    SetObject::finishInit};
+
+const JSClass SetObject::class_ = {
+    "Set",
+    JSCLASS_HAS_PRIVATE | JSCLASS_HAS_RESERVED_SLOTS(SetObject::SlotCount) |
+        JSCLASS_HAS_CACHED_PROTO(JSProto_Set) | JSCLASS_FOREGROUND_FINALIZE |
+        JSCLASS_SKIP_NURSERY_FINALIZE,
+    &SetObject::classOps_,
+    &SetObject::classSpec_,
+};
+
+const JSClass SetObject::protoClass_ = {
+    "Set.prototype", JSCLASS_HAS_CACHED_PROTO(JSProto_Set), JS_NULL_CLASS_OPS,
+    &SetObject::classSpec_};
+
+const JSPropertySpec SetObject::properties[] = {
+    JS_PSG("size", size, 0),
+    JS_STRING_SYM_PS(toStringTag, "Set", JSPROP_READONLY), JS_PS_END};
+
+// clang-format off
+const JSFunctionSpec SetObject::methods[] = {
+    JS_FN("has", has, 1, 0),
+    JS_FN("add", add, 1, 0),
+    JS_FN("delete", delete_, 1, 0),
+    JS_FN("entries", entries, 0, 0),
+    JS_FN("clear", clear, 0, 0),
+    JS_SELF_HOSTED_FN("forEach", "SetForEach", 2, 0),
+    JS_FN("values", values, 0, 0),
+    // @@iterator and |keys| re-defined in finishInit so that they have the
+    // same identity as |values|.
+    JS_FN("keys", values, 0, 0),
+    JS_SYM_FN(iterator, values, 0, 0),
+    JS_FS_END
+};
+// clang-format on
+
+const JSPropertySpec SetObject::staticProperties[] = {
+    JS_SELF_HOSTED_SYM_GET(species, "$SetSpecies", 0), JS_PS_END};
+
+/* static */ bool SetObject::finishInit(JSContext* cx, HandleObject ctor,
+                                        HandleObject proto) {
+  HandleNativeObject nativeProto = proto.as<NativeObject>();
+
+  RootedValue valuesFn(cx);
+  RootedId valuesId(cx, NameToId(cx->names().values));
+  if (!NativeGetProperty(cx, nativeProto, valuesId, &valuesFn)) {
+    return false;
+  }
+
+  // 23.2.3.8 Set.prototype.keys()
+  // The initial value of the "keys" property is the same function object
+  // as the initial value of the "values" property.
+  RootedId keysId(cx, NameToId(cx->names().keys));
+  if (!NativeDefineDataProperty(cx, nativeProto, keysId, valuesFn, 0)) {
+    return false;
+  }
+
+  // 23.2.3.11 Set.prototype[@@iterator]()
+  // See above.
+  RootedId iteratorId(
+      cx, SYMBOL_TO_JSID(JS::GetWellKnownSymbol(cx, JS::SymbolCode::iterator)));
+  return NativeDefineDataProperty(cx, nativeProto, iteratorId, valuesFn, 0);
+}
+
+bool SetObject::keys(JSContext* cx, HandleObject obj,
+                     JS::MutableHandle<GCVector<JS::Value>> keys) {
+  ValueSet* set = obj->as<SetObject>().getData();
+  if (!set) {
+    return false;
+  }
+
+  for (ValueSet::Range r = set->all(); !r.empty(); r.popFront()) {
+    if (!keys.append(r.front().get())) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool SetObject::add(JSContext* cx, HandleObject obj, HandleValue k) {
+  ValueSet* set = obj->as<SetObject>().getData();
+  if (!set) {
+    return false;
+  }
+
+  Rooted<HashableValue> key(cx);
+  if (!key.setValue(cx, k)) {
+    return false;
+  }
+
+  if (!PostWriteBarrier(&obj->as<SetObject>(), key.value()) || !set->put(key)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  return true;
+}
+
+SetObject* SetObject::create(JSContext* cx,
+                             HandleObject proto /* = nullptr */) {
+  auto set = cx->make_unique<ValueSet>(cx->zone(),
+                                       cx->realm()->randomHashCodeScrambler());
+  if (!set) {
+    return nullptr;
+  }
+
+  if (!set->init()) {
+    ReportOutOfMemory(cx);
+    return nullptr;
+  }
+
+  SetObject* obj = NewObjectWithClassProto<SetObject>(cx, proto);
+  if (!obj) {
+    return nullptr;
+  }
+
+  bool insideNursery = IsInsideNursery(obj);
+  if (insideNursery && !cx->nursery().addSetWithNurseryMemory(obj)) {
+    ReportOutOfMemory(cx);
+    return nullptr;
+  }
+
+  InitObjectPrivate(obj, set.release(), MemoryUse::MapObjectTable);
+  obj->initReservedSlot(NurseryKeysSlot, PrivateValue(nullptr));
+  obj->initReservedSlot(HasNurseryMemorySlot, JS::BooleanValue(insideNursery));
+  return obj;
+}
+
+void SetObject::trace(JSTracer* trc, JSObject* obj) {
+  SetObject* setobj = static_cast<SetObject*>(obj);
+  if (ValueSet* set = setobj->getData()) {
+    for (ValueSet::Range r = set->all(); !r.empty(); r.popFront()) {
+      TraceKey(r, r.front(), trc);
+    }
+  }
+}
+
+void SetObject::finalize(JSFreeOp* fop, JSObject* obj) {
+  MOZ_ASSERT(fop->onMainThread());
+  SetObject* setobj = static_cast<SetObject*>(obj);
+  if (ValueSet* set = setobj->getData()) {
+    fop->delete_(obj, set, MemoryUse::MapObjectTable);
+  }
+}
+
+/* static */
+void SetObject::sweepAfterMinorGC(JSFreeOp* fop, SetObject* setobj) {
+  bool wasInsideNursery = IsInsideNursery(setobj);
+  if (wasInsideNursery && !IsForwarded(setobj)) {
+    finalize(fop, setobj);
+    return;
+  }
+
+  setobj = MaybeForwarded(setobj);
+  setobj->getData()->destroyNurseryRanges();
+  SetHasNurseryMemory(setobj, false);
+
+  if (wasInsideNursery) {
+    AddCellMemory(setobj, sizeof(ValueSet), MemoryUse::MapObjectTable);
+  }
+}
+
+bool SetObject::isBuiltinAdd(HandleValue add) {
+  return IsNativeFunction(add, SetObject::add);
+}
+
+bool SetObject::construct(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (!ThrowIfNotConstructing(cx, args, "Set")) {
+    return false;
+  }
+
+  RootedObject proto(cx);
+  if (!GetPrototypeFromBuiltinConstructor(cx, args, JSProto_Set, &proto)) {
+    return false;
+  }
+
+  Rooted<SetObject*> obj(cx, SetObject::create(cx, proto));
+  if (!obj) {
+    return false;
+  }
+
+  if (!args.get(0).isNullOrUndefined()) {
+    RootedValue iterable(cx, args[0]);
+    bool optimized = false;
+    if (!IsOptimizableInitForSet<GlobalObject::getOrCreateSetPrototype,
+                                 isBuiltinAdd>(cx, obj, iterable, &optimized)) {
+      return false;
+    }
+
+    if (optimized) {
+      RootedValue keyVal(cx);
+      Rooted<HashableValue> key(cx);
+      ValueSet* set = obj->getData();
+      RootedArrayObject array(cx, &iterable.toObject().as<ArrayObject>());
+      for (uint32_t index = 0; index < array->getDenseInitializedLength();
+           ++index) {
+        keyVal.set(array->getDenseElement(index));
+        MOZ_ASSERT(!keyVal.isMagic(JS_ELEMENTS_HOLE));
+
+        if (!key.setValue(cx, keyVal)) {
+          return false;
+        }
+        if (!PostWriteBarrier(obj, key.value()) || !set->put(key)) {
+          ReportOutOfMemory(cx);
+          return false;
+        }
+      }
+    } else {
+      FixedInvokeArgs<1> args2(cx);
+      args2[0].set(args[0]);
+
+      RootedValue thisv(cx, ObjectValue(*obj));
+      if (!CallSelfHostedFunction(cx, cx->names().SetConstructorInit, thisv,
+                                  args2, args2.rval())) {
+        return false;
+      }
+    }
+  }
+
+  args.rval().setObject(*obj);
+  return true;
+}
+
+bool SetObject::is(HandleValue v) {
+  return v.isObject() && v.toObject().hasClass(&class_) &&
+         v.toObject().as<SetObject>().getPrivate();
+}
+
+bool SetObject::is(HandleObject o) {
+  return o->hasClass(&class_) && o->as<SetObject>().getPrivate();
+}
+
+ValueSet& SetObject::extract(HandleObject o) {
+  MOZ_ASSERT(o->hasClass(&SetObject::class_));
+  return *o->as<SetObject>().getData();
+}
+
+ValueSet& SetObject::extract(const CallArgs& args) {
+  MOZ_ASSERT(args.thisv().isObject());
+  MOZ_ASSERT(args.thisv().toObject().hasClass(&SetObject::class_));
+  return *static_cast<SetObject&>(args.thisv().toObject()).getData();
+}
+
+uint32_t SetObject::size(JSContext* cx, HandleObject obj) {
+  MOZ_ASSERT(SetObject::is(obj));
+  ValueSet& set = extract(obj);
+  static_assert(sizeof(set.count()) <= sizeof(uint32_t),
+                "set count must be precisely representable as a JS number");
+  return set.count();
+}
+
+bool SetObject::size_impl(JSContext* cx, const CallArgs& args) {
+  MOZ_ASSERT(is(args.thisv()));
+
+  ValueSet& set = extract(args);
+  static_assert(sizeof(set.count()) <= sizeof(uint32_t),
+                "set count must be precisely representable as a JS number");
+  args.rval().setNumber(set.count());
+  return true;
+}
+
+bool SetObject::size(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<SetObject::is, SetObject::size_impl>(cx, args);
+}
+
+bool SetObject::has_impl(JSContext* cx, const CallArgs& args) {
+  MOZ_ASSERT(is(args.thisv()));
+
+  ValueSet& set = extract(args);
+  ARG0_KEY(cx, args, key);
+  args.rval().setBoolean(set.has(key));
+  return true;
+}
+
+bool SetObject::has(JSContext* cx, HandleObject obj, HandleValue key,
+                    bool* rval) {
+  MOZ_ASSERT(SetObject::is(obj));
+
+  ValueSet& set = extract(obj);
+  Rooted<HashableValue> k(cx);
+
+  if (!k.setValue(cx, key)) {
+    return false;
+  }
+
+  *rval = set.has(k);
+  return true;
+}
+
+bool SetObject::has(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<SetObject::is, SetObject::has_impl>(cx, args);
+}
+
+bool SetObject::add_impl(JSContext* cx, const CallArgs& args) {
+  MOZ_ASSERT(is(args.thisv()));
+
+  ValueSet& set = extract(args);
+  ARG0_KEY(cx, args, key);
+  if (!PostWriteBarrier(&args.thisv().toObject().as<SetObject>(),
+                        key.value()) ||
+      !set.put(key)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  args.rval().set(args.thisv());
+  return true;
+}
+
+bool SetObject::add(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<SetObject::is, SetObject::add_impl>(cx, args);
+}
+
+bool SetObject::delete_(JSContext* cx, HandleObject obj, HandleValue key,
+                        bool* rval) {
+  MOZ_ASSERT(SetObject::is(obj));
+
+  ValueSet& set = extract(obj);
+  Rooted<HashableValue> k(cx);
+
+  if (!k.setValue(cx, key)) {
+    return false;
+  }
+
+  if (!set.remove(k, rval)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  return true;
+}
+
+bool SetObject::delete_impl(JSContext* cx, const CallArgs& args) {
+  MOZ_ASSERT(is(args.thisv()));
+
+  ValueSet& set = extract(args);
+  ARG0_KEY(cx, args, key);
+  bool found;
+  if (!set.remove(key, &found)) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  args.rval().setBoolean(found);
+  return true;
+}
+
+bool SetObject::delete_(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod<SetObject::is, SetObject::delete_impl>(cx, args);
+}
+
+bool SetObject::iterator(JSContext* cx, IteratorKind kind, HandleObject obj,
+                         MutableHandleValue iter) {
+  MOZ_ASSERT(SetObject::is(obj));
+  ValueSet& set = extract(obj);
+  Rooted<JSObject*> iterobj(cx, SetIteratorObject::create(cx, obj, &set, kind));
+  if (!iterobj) {
+    return false;
+  }
+  iter.setObject(*iterobj);
+  return true;
+}
+
+bool SetObject::iterator_impl(JSContext* cx, const CallArgs& args,
+                              IteratorKind kind) {
+  Rooted<SetObject*> setobj(cx, &args.thisv().toObject().as<SetObject>());
+  ValueSet& set = *setobj->getData();
+  Rooted<JSObject*> iterobj(cx,
+                            SetIteratorObject::create(cx, setobj, &set, kind));
+  if (!iterobj) {
+    return false;
+  }
+  args.rval().setObject(*iterobj);
+  return true;
+}
+
+bool SetObject::values_impl(JSContext* cx, const CallArgs& args) {
+  return iterator_impl(cx, args, Values);
+}
+
+bool SetObject::values(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, values_impl, args);
+}
+
+bool SetObject::entries_impl(JSContext* cx, const CallArgs& args) {
+  return iterator_impl(cx, args, Entries);
+}
+
+bool SetObject::entries(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, entries_impl, args);
+}
+
+bool SetObject::clear(JSContext* cx, HandleObject obj) {
+  MOZ_ASSERT(SetObject::is(obj));
+  ValueSet& set = extract(obj);
+  if (!set.clear()) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  return true;
+}
+
+bool SetObject::clear_impl(JSContext* cx, const CallArgs& args) {
+  Rooted<SetObject*> setobj(cx, &args.thisv().toObject().as<SetObject>());
+  if (!setobj->getData()->clear()) {
+    ReportOutOfMemory(cx);
+    return false;
+  }
+  args.rval().setUndefined();
+  return true;
+}
+
+bool SetObject::clear(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+  return CallNonGenericMethod(cx, is, clear_impl, args);
+}
+
+/*** JS static utility functions ********************************************/
+
+static bool forEach(const char* funcName, JSContext* cx, HandleObject obj,
+                    HandleValue callbackFn, HandleValue thisArg) {
+  CHECK_THREAD(cx);
+
+  RootedId forEachId(cx, NameToId(cx->names().forEach));
+  RootedFunction forEachFunc(
+      cx, JS::GetSelfHostedFunction(cx, funcName, forEachId, 2));
+  if (!forEachFunc) {
+    return false;
+  }
+
+  RootedValue fval(cx, ObjectValue(*forEachFunc));
+  return Call(cx, fval, obj, callbackFn, thisArg, &fval);
+}
+
+// Handles Clear/Size for public jsapi map/set access
+template <typename RetT>
+RetT CallObjFunc(RetT (*ObjFunc)(JSContext*, HandleObject), JSContext* cx,
+                 HandleObject obj) {
+  CHECK_THREAD(cx);
+  cx->check(obj);
+
+  // Always unwrap, in case this is an xray or cross-compartment wrapper.
+  RootedObject unwrappedObj(cx);
+  unwrappedObj = UncheckedUnwrap(obj);
+
+  // Enter the realm of the backing object before calling functions on
+  // it.
+  JSAutoRealm ar(cx, unwrappedObj);
+  return ObjFunc(cx, unwrappedObj);
+}
+
+// Handles Has/Delete for public jsapi map/set access
+bool CallObjFunc(bool (*ObjFunc)(JSContext* cx, HandleObject obj,
+                                 HandleValue key, bool* rval),
+                 JSContext* cx, HandleObject obj, HandleValue key, bool* rval) {
+  CHECK_THREAD(cx);
+  cx->check(obj, key);
+
+  // Always unwrap, in case this is an xray or cross-compartment wrapper.
+  RootedObject unwrappedObj(cx);
+  unwrappedObj = UncheckedUnwrap(obj);
+  JSAutoRealm ar(cx, unwrappedObj);
+
+  // If we're working with a wrapped map/set, rewrap the key into the
+  // compartment of the unwrapped map/set.
+  RootedValue wrappedKey(cx, key);
+  if (obj != unwrappedObj) {
+    if (!JS_WrapValue(cx, &wrappedKey)) {
+      return false;
+    }
+  }
+  return ObjFunc(cx, unwrappedObj, wrappedKey, rval);
+}
+
+// Handles iterator generation for public jsapi map/set access
+template <typename Iter>
+bool CallObjFunc(bool (*ObjFunc)(JSContext* cx, Iter kind, HandleObject obj,
+                                 MutableHandleValue iter),
+                 JSContext* cx, Iter iterType, HandleObject obj,
+                 MutableHandleValue rval) {
+  CHECK_THREAD(cx);
+  cx->check(obj);
+
+  // Always unwrap, in case this is an xray or cross-compartment wrapper.
+  RootedObject unwrappedObj(cx);
+  unwrappedObj = UncheckedUnwrap(obj);
+  {
+    // Retrieve the iterator while in the unwrapped map/set's compartment,
+    // otherwise we'll crash on a compartment assert.
+    JSAutoRealm ar(cx, unwrappedObj);
+    if (!ObjFunc(cx, iterType, unwrappedObj, rval)) {
+      return false;
+    }
+  }
+
+  // If the caller is in a different compartment than the map/set, rewrap the
+  // iterator object into the caller's compartment.
+  if (obj != unwrappedObj) {
+    if (!JS_WrapValue(cx, rval)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+/*** JS public APIs *********************************************************/
+
+JS_PUBLIC_API JSObject* JS::NewMapObject(JSContext* cx) {
+  return MapObject::create(cx);
+}
+
+JS_PUBLIC_API uint32_t JS::MapSize(JSContext* cx, HandleObject obj) {
+  return CallObjFunc<uint32_t>(&MapObject::size, cx, obj);
+}
+
+JS_PUBLIC_API bool JS::MapGet(JSContext* cx, HandleObject obj, HandleValue key,
+                              MutableHandleValue rval) {
+  CHECK_THREAD(cx);
+  cx->check(obj, key, rval);
+
+  // Unwrap the object, and enter its realm. If object isn't wrapped,
+  // this is essentially a noop.
+  RootedObject unwrappedObj(cx);
+  unwrappedObj = UncheckedUnwrap(obj);
+  {
+    JSAutoRealm ar(cx, unwrappedObj);
+    RootedValue wrappedKey(cx, key);
+
+    // If we passed in a wrapper, wrap our key into its compartment now.
+    if (obj != unwrappedObj) {
+      if (!JS_WrapValue(cx, &wrappedKey)) {
+        return false;
+      }
+    }
+    if (!MapObject::get(cx, unwrappedObj, wrappedKey, rval)) {
+      return false;
+    }
+  }
+
+  // If we passed in a wrapper, wrap our return value on the way out.
+  if (obj != unwrappedObj) {
+    if (!JS_WrapValue(cx, rval)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+JS_PUBLIC_API bool JS::MapSet(JSContext* cx, HandleObject obj, HandleValue key,
+                              HandleValue val) {
+  CHECK_THREAD(cx);
+  cx->check(obj, key, val);
+
+  // Unwrap the object, and enter its compartment. If object isn't wrapped,
+  // this is essentially a noop.
+  RootedObject unwrappedObj(cx);
+  unwrappedObj = UncheckedUnwrap(obj);
+  {
+    JSAutoRealm ar(cx, unwrappedObj);
+
+    // If we passed in a wrapper, wrap both key and value before adding to
+    // the map
+    RootedValue wrappedKey(cx, key);
+    RootedValue wrappedValue(cx, val);
+    if (obj != unwrappedObj) {
+      if (!JS_WrapValue(cx, &wrappedKey) || !JS_WrapValue(cx, &wrappedValue)) {
+        return false;
+      }
+    }
+    return MapObject::set(cx, unwrappedObj, wrappedKey, wrappedValue);
+  }
+}
+
+JS_PUBLIC_API bool JS::MapHas(JSContext* cx, HandleObject obj, HandleValue key,
+                              bool* rval) {
+  return CallObjFunc(MapObject::has, cx, obj, key, rval);
+}
+
+JS_PUBLIC_API bool JS::MapDelete(JSContext* cx, HandleObject obj,
+                                 HandleValue key, bool* rval) {
+  return CallObjFunc(MapObject::delete_, cx, obj, key, rval);
+}
+
+JS_PUBLIC_API bool JS::MapClear(JSContext* cx, HandleObject obj) {
+  return CallObjFunc(&MapObject::clear, cx, obj);
+}
+
+JS_PUBLIC_API bool JS::MapKeys(JSContext* cx, HandleObject obj,
+                               MutableHandleValue rval) {
+  return CallObjFunc(&MapObject::iterator, cx, MapObject::Keys, obj, rval);
+}
+
+JS_PUBLIC_API bool JS::MapValues(JSContext* cx, HandleObject obj,
+                                 MutableHandleValue rval) {
+  return CallObjFunc(&MapObject::iterator, cx, MapObject::Values, obj, rval);
+}
+
+JS_PUBLIC_API bool JS::MapEntries(JSContext* cx, HandleObject obj,
+                                  MutableHandleValue rval) {
+  return CallObjFunc(&MapObject::iterator, cx, MapObject::Entries, obj, rval);
+}
+
+JS_PUBLIC_API bool JS::MapForEach(JSContext* cx, HandleObject obj,
+                                  HandleValue callbackFn, HandleValue thisVal) {
+  return forEach("MapForEach", cx, obj, callbackFn, thisVal);
+}
+
+JS_PUBLIC_API JSObject* JS::NewSetObject(JSContext* cx) {
+  return SetObject::create(cx);
+}
+
+JS_PUBLIC_API uint32_t JS::SetSize(JSContext* cx, HandleObject obj) {
+  return CallObjFunc<uint32_t>(&SetObject::size, cx, obj);
+}
+
+JS_PUBLIC_API bool JS::SetAdd(JSContext* cx, HandleObject obj,
+                              HandleValue key) {
+  CHECK_THREAD(cx);
+  cx->check(obj, key);
+
+  // Unwrap the object, and enter its compartment. If object isn't wrapped,
+  // this is essentially a noop.
+  RootedObject unwrappedObj(cx);
+  unwrappedObj = UncheckedUnwrap(obj);
+  {
+    JSAutoRealm ar(cx, unwrappedObj);
+
+    // If we passed in a wrapper, wrap key before adding to the set
+    RootedValue wrappedKey(cx, key);
+    if (obj != unwrappedObj) {
+      if (!JS_WrapValue(cx, &wrappedKey)) {
+        return false;
+      }
+    }
+    return SetObject::add(cx, unwrappedObj, wrappedKey);
+  }
+}
+
+JS_PUBLIC_API bool JS::SetHas(JSContext* cx, HandleObject obj, HandleValue key,
+                              bool* rval) {
+  return CallObjFunc(SetObject::has, cx, obj, key, rval);
+}
+
+JS_PUBLIC_API bool JS::SetDelete(JSContext* cx, HandleObject obj,
+                                 HandleValue key, bool* rval) {
+  return CallObjFunc(SetObject::delete_, cx, obj, key, rval);
+}
+
+JS_PUBLIC_API bool JS::SetClear(JSContext* cx, HandleObject obj) {
+  return CallObjFunc(&SetObject::clear, cx, obj);
+}
+
+JS_PUBLIC_API bool JS::SetKeys(JSContext* cx, HandleObject obj,
+                               MutableHandleValue rval) {
+  return SetValues(cx, obj, rval);
+}
+
+JS_PUBLIC_API bool JS::SetValues(JSContext* cx, HandleObject obj,
+                                 MutableHandleValue rval) {
+  return CallObjFunc(&SetObject::iterator, cx, SetObject::Values, obj, rval);
+}
+
+JS_PUBLIC_API bool JS::SetEntries(JSContext* cx, HandleObject obj,
+                                  MutableHandleValue rval) {
+  return CallObjFunc(&SetObject::iterator, cx, SetObject::Entries, obj, rval);
+}
+
+JS_PUBLIC_API bool JS::SetForEach(JSContext* cx, HandleObject obj,
+                                  HandleValue callbackFn, HandleValue thisVal) {
+  return forEach("SetForEach", cx, obj, callbackFn, thisVal);
+}