1 files changed, 37 insertions, 8 deletions

diff --git a/deps/v8/src/objects/map-inl.h b/deps/v8/src/objects/map-inl.h
index 05d24169966..59f061dc050 100644
--- a/deps/v8/src/objects/map-inl.h
+++ b/deps/v8/src/objects/map-inl.h
@@ -6,7 +6,6 @@
 #define V8_OBJECTS_MAP_INL_H_
 
 #include "src/objects/map.h"
-
 #include "src/field-type.h"
 #include "src/objects-inl.h"
 #include "src/objects/api-callbacks-inl.h"
@@ -298,6 +297,17 @@ int Map::UnusedPropertyFields() const {
   return unused;
 }
 
+int Map::UnusedInObjectProperties() const {
+  // Like Map::UnusedPropertyFields(), but returns 0 for out of object
+  // properties.
+  int value = used_or_unused_instance_size_in_words();
+  DCHECK_IMPLIES(!IsJSObjectMap(), value == 0);
+  if (value >= JSObject::kFieldsAdded) {
+    return instance_size_in_words() - value;
+  }
+  return 0;
+}
+
 int Map::used_or_unused_instance_size_in_words() const {
   return RELAXED_READ_BYTE_FIELD(this, kUsedOrUnusedInstanceSizeInWordsOffset);
 }
@@ -349,6 +359,17 @@ void Map::CopyUnusedPropertyFields(Map* map) {
   DCHECK_EQ(UnusedPropertyFields(), map->UnusedPropertyFields());
 }
 
+void Map::CopyUnusedPropertyFieldsAdjustedForInstanceSize(Map* map) {
+  int value = map->used_or_unused_instance_size_in_words();
+  if (value >= JSValue::kFieldsAdded) {
+    // Unused in-object fields. Adjust the offset from the object’s start
+    // so it matches the distance to the object’s end.
+    value += instance_size_in_words() - map->instance_size_in_words();
+  }
+  set_used_or_unused_instance_size_in_words(value);
+  DCHECK_EQ(UnusedPropertyFields(), map->UnusedPropertyFields());
+}
+
 void Map::AccountAddedPropertyField() {
   // Update used instance size and unused property fields number.
   STATIC_ASSERT(JSObject::kFieldsAdded == JSObject::kHeaderSize / kPointerSize);
@@ -503,6 +524,17 @@ bool Map::CanTransition() const {
 bool Map::IsBooleanMap() const {
   return this == GetReadOnlyRoots().boolean_map();
 }
+
+bool Map::IsNullMap() const { return this == GetReadOnlyRoots().null_map(); }
+
+bool Map::IsUndefinedMap() const {
+  return this == GetReadOnlyRoots().undefined_map();
+}
+
+bool Map::IsNullOrUndefinedMap() const {
+  return IsNullMap() || IsUndefinedMap();
+}
+
 bool Map::IsPrimitiveMap() const {
   return instance_type() <= LAST_PRIMITIVE_TYPE;
 }
@@ -536,8 +568,7 @@ Object* Map::prototype() const { return READ_FIELD(this, kPrototypeOffset); }
 void Map::set_prototype(Object* value, WriteBarrierMode mode) {
   DCHECK(value->IsNull() || value->IsJSReceiver());
   WRITE_FIELD(this, kPrototypeOffset, value);
-  CONDITIONAL_WRITE_BARRIER(Heap::FromWritableHeapObject(this), this,
-                            kPrototypeOffset, value, mode);
+  CONDITIONAL_WRITE_BARRIER(this, kPrototypeOffset, value, mode);
 }
 
 LayoutDescriptor* Map::layout_descriptor_gc_safe() const {
@@ -657,8 +688,7 @@ Object* Map::prototype_info() const {
 void Map::set_prototype_info(Object* value, WriteBarrierMode mode) {
   CHECK(is_prototype_map());
   WRITE_FIELD(this, Map::kTransitionsOrPrototypeInfoOffset, value);
-  CONDITIONAL_WRITE_BARRIER(Heap::FromWritableHeapObject(this), this,
-                            Map::kTransitionsOrPrototypeInfoOffset, value,
+  CONDITIONAL_WRITE_BARRIER(this, Map::kTransitionsOrPrototypeInfoOffset, value,
                             mode);
 }
 
@@ -672,7 +702,6 @@ void Map::SetBackPointer(Object* value, WriteBarrierMode mode) {
 }
 
 ACCESSORS(Map, dependent_code, DependentCode, kDependentCodeOffset)
-ACCESSORS(Map, weak_cell_cache, Object, kWeakCellCacheOffset)
 ACCESSORS(Map, prototype_validity_cell, Object, kPrototypeValidityCellOffset)
 ACCESSORS(Map, constructor_or_backpointer, Object,
           kConstructorOrBackPointerOffset)
@@ -746,8 +775,8 @@ int NormalizedMapCache::GetIndex(Handle<Map> map) {
 }
 
 bool NormalizedMapCache::IsNormalizedMapCache(const HeapObject* obj) {
-  if (!obj->IsFixedArray()) return false;
-  if (FixedArray::cast(obj)->length() != NormalizedMapCache::kEntries) {
+  if (!obj->IsWeakFixedArray()) return false;
+  if (WeakFixedArray::cast(obj)->length() != NormalizedMapCache::kEntries) {
     return false;
   }
 #ifdef VERIFY_HEAP