Mark maps having a hidden prototype rather than maps of hidden prototypes.

src/objects.h

 // Copyright 2015 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 1284 matching lines @@
       ShouldThrow should_throw);
 
   MUST_USE_RESULT static inline MaybeHandle<Object> GetElement(
       Isolate* isolate, Handle<Object> object, uint32_t index,
       LanguageMode language_mode = SLOPPY);
 
   MUST_USE_RESULT static inline MaybeHandle<Object> SetElement(
       Isolate* isolate, Handle<Object> object, uint32_t index,
       Handle<Object> value, LanguageMode language_mode);
 
-  // Get the first non-hidden prototype.
-  static inline MaybeHandle<Object> GetPrototype(Isolate* isolate,
-                                                 Handle<Object> receiver);
-
-  MUST_USE_RESULT static Maybe<bool> HasInPrototypeChain(Isolate* isolate,
-                                                         Handle<Object> object,
-                                                         Handle<Object> proto);
-
   // Returns the permanent hash code associated with this object. May return
   // undefined if not yet created.
   Object* GetHash();
 
   // Returns undefined for JSObjects, but returns the hash code for simple
   // objects.  This avoids a double lookup in the cases where we know we will
   // add the hash to the JSObject if it does not already exist.
   Object* GetSimpleHash();
 
   // Returns the permanent hash code associated with this object depending on
@@ skipping 56 matching lines @@
 
   // Prints this object with details.
   void Print(std::ostream& os);  // NOLINT
 #else
   void Print() { ShortPrint(); }
   void Print(std::ostream& os) { ShortPrint(os); }  // NOLINT
 #endif
 
  private:
   friend class LookupIterator;
-  friend class PrototypeIterator;
+  friend class StringStream;
 
   // Return the map of the root of object's prototype chain.
   Map* GetRootMap(Isolate* isolate);
 
   // Helper for SetProperty and SetSuperProperty.
   // Return value is only meaningful if [found] is set to true on return.
   MUST_USE_RESULT static Maybe<bool> SetPropertyInternal(
       LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
       StoreFromKeyed store_mode, bool* found);
 
@@ skipping 405 matching lines @@
 
   // ES6 section 7.1.1 ToPrimitive
   MUST_USE_RESULT static MaybeHandle<Object> ToPrimitive(
       Handle<JSReceiver> receiver,
       ToPrimitiveHint hint = ToPrimitiveHint::kDefault);
   MUST_USE_RESULT static MaybeHandle<Object> OrdinaryToPrimitive(
       Handle<JSReceiver> receiver, OrdinaryToPrimitiveHint hint);
 
   static MaybeHandle<Context> GetFunctionRealm(Handle<JSReceiver> receiver);
 
+  // Get the first non-hidden prototype.
+  static inline MaybeHandle<Object> GetPrototype(Isolate* isolate,
+                                                 Handle<JSReceiver> receiver);
+
+  MUST_USE_RESULT static Maybe<bool> HasInPrototypeChain(
+      Isolate* isolate, Handle<JSReceiver> object, Handle<Object> proto);
+
   // Implementation of [[HasProperty]], ECMA-262 5th edition, section 8.12.6.
   MUST_USE_RESULT static Maybe<bool> HasProperty(LookupIterator* it);
   MUST_USE_RESULT static inline Maybe<bool> HasProperty(
       Handle<JSReceiver> object, Handle<Name> name);
   MUST_USE_RESULT static inline Maybe<bool> HasElement(
       Handle<JSReceiver> object, uint32_t index);
 
   MUST_USE_RESULT static inline Maybe<bool> HasOwnProperty(
       Handle<JSReceiver> object, Handle<Name> name);
 
@@ skipping 3730 matching lines @@
   inline uint32_t bit_field3() const;
   inline void set_bit_field3(uint32_t bits);
 
   class EnumLengthBits:             public BitField<int,
       0, kDescriptorIndexBitCount> {};  // NOLINT
   class NumberOfOwnDescriptorsBits: public BitField<int,
       kDescriptorIndexBitCount, kDescriptorIndexBitCount> {};  // NOLINT
   STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
   class DictionaryMap : public BitField<bool, 20, 1> {};
   class OwnsDescriptors : public BitField<bool, 21, 1> {};
-  class IsHiddenPrototype : public BitField<bool, 22, 1> {};
+  class HasHiddenPrototype : public BitField<bool, 22, 1> {};
   class Deprecated : public BitField<bool, 23, 1> {};
   class IsUnstable : public BitField<bool, 24, 1> {};
   class IsMigrationTarget : public BitField<bool, 25, 1> {};
   class IsStrong : public BitField<bool, 26, 1> {};
   class NewTargetIsBase : public BitField<bool, 27, 1> {};
   // Bit 28 is free.
 
   // Keep this bit field at the very end for better code in
   // Builtins::kJSConstructStubGeneric stub.
   // This counter is used for in-object slack tracking.
@@ skipping 58 matching lines @@
   // property will not be used to create instances of the function.
   // See ECMA-262, 13.2.2.
   inline void set_non_instance_prototype(bool value);
   inline bool has_non_instance_prototype();
 
   // Tells whether the instance has a [[Construct]] internal method.
   // This property is implemented according to ES6, section 7.2.4.
   inline void set_is_constructor(bool value);
   inline bool is_constructor() const;
 
-  // Tells whether the instance with this map should be ignored by the
-  // Object.getPrototypeOf() function and the __proto__ accessor.
-  inline void set_is_hidden_prototype();
-  inline bool is_hidden_prototype() const;
+  // Tells whether the instance with this map has a hidden prototype.
+  inline void set_has_hidden_prototype(bool value);
+  inline bool has_hidden_prototype() const;
 
   // Records and queries whether the instance has a named interceptor.
   inline void set_has_named_interceptor();
   inline bool has_named_interceptor();
 
   // Records and queries whether the instance has an indexed interceptor.
   inline void set_has_indexed_interceptor();
   inline bool has_indexed_interceptor();
 
   // Tells whether the instance is undetectable.
@@ skipping 5136 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_