[builtins] move String.prototype[@@iterator] to C++ builtin

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 <memory>
 
@@ skipping 414 matching lines @@
   V(JS_PROXY_TYPE)                                              \
   V(JS_SET_TYPE)                                                \
   V(JS_MAP_TYPE)                                                \
   V(JS_SET_ITERATOR_TYPE)                                       \
   V(JS_MAP_ITERATOR_TYPE)                                       \
   V(JS_WEAK_MAP_TYPE)                                           \
   V(JS_WEAK_SET_TYPE)                                           \
   V(JS_PROMISE_TYPE)                                            \
   V(JS_REGEXP_TYPE)                                             \
   V(JS_ERROR_TYPE)                                              \
+  V(JS_STRING_ITERATOR_TYPE)                                    \
                                                                 \
   V(JS_BOUND_FUNCTION_TYPE)                                     \
   V(JS_FUNCTION_TYPE)                                           \
   V(DEBUG_INFO_TYPE)                                            \
   V(BREAK_POINT_INFO_TYPE)
 
 // Since string types are not consecutive, this macro is used to
 // iterate over them.
 #define STRING_TYPE_LIST(V)                                                   \
   V(STRING_TYPE, kVariableSizeSentinel, string, String)                       \
@@ skipping 272 matching lines @@
   JS_DATA_VIEW_TYPE,
   JS_SET_TYPE,
   JS_MAP_TYPE,
   JS_SET_ITERATOR_TYPE,
   JS_MAP_ITERATOR_TYPE,
   JS_WEAK_MAP_TYPE,
   JS_WEAK_SET_TYPE,
   JS_PROMISE_TYPE,
   JS_REGEXP_TYPE,
   JS_ERROR_TYPE,
+  JS_STRING_ITERATOR_TYPE,
   JS_BOUND_FUNCTION_TYPE,
   JS_FUNCTION_TYPE,  // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE
 
   // Pseudo-types
   FIRST_TYPE = 0x0,
   LAST_TYPE = JS_FUNCTION_TYPE,
   FIRST_NAME_TYPE = FIRST_TYPE,
   LAST_NAME_TYPE = SYMBOL_TYPE,
   FIRST_UNIQUE_NAME_TYPE = INTERNALIZED_STRING_TYPE,
   LAST_UNIQUE_NAME_TYPE = SYMBOL_TYPE,
@@ skipping 262 matching lines @@
   V(Boolean)                     \
   V(JSArray)                     \
   V(JSArrayBuffer)               \
   V(JSArrayBufferView)           \
   V(JSCollection)                \
   V(JSTypedArray)                \
   V(JSDataView)                  \
   V(JSProxy)                     \
   V(JSError)                     \
   V(JSPromise)                   \
+  V(JSStringIterator)            \
   V(JSSet)                       \
   V(JSMap)                       \
   V(JSSetIterator)               \
   V(JSMapIterator)               \
   V(JSWeakCollection)            \
   V(JSWeakMap)                   \
   V(JSWeakSet)                   \
   V(JSRegExp)                    \
   V(HashTable)                   \
   V(Dictionary)                  \
@@ skipping 1586 matching lines @@
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataPropertyDescriptor);
 };
 
 
 // JSIteratorResult is just a JSObject with a specific initial map.
 // This initial map adds in-object properties for "done" and "value",
 // as specified by ES6 section 25.1.1.3 The IteratorResult Interface
 class JSIteratorResult: public JSObject {
  public:
+  DECL_ACCESSORS(value, Object)
+
+  DECL_ACCESSORS(done, Object)
+
   // Offsets of object fields.
   static const int kValueOffset = JSObject::kHeaderSize;
   static const int kDoneOffset = kValueOffset + kPointerSize;
   static const int kSize = kDoneOffset + kPointerSize;
   // Indices of in-object properties.
   static const int kValueIndex = 0;
   static const int kDoneIndex = 1;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSIteratorResult);
@@ skipping 7608 matching lines @@
   static void Clear(Handle<JSMap> map);
 
   // Dispatched behavior.
   DECLARE_PRINTER(JSMap)
   DECLARE_VERIFIER(JSMap)
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap);
 };
 
+class JSStringIterator : public JSObject {
+ public:
+  // Dispatched behavior.
+  DECLARE_PRINTER(JSStringIterator)
+  DECLARE_VERIFIER(JSStringIterator)
+
+  DECLARE_CAST(JSStringIterator)
+
+  // [string]: the [[IteratedString]] internal field.
+  DECL_ACCESSORS(string, String)
+
+  // [index]: The [[StringIteratorNextIndex]] internal field.
+  inline int index() const;
+  inline void set_index(int value);
+
+  static const int kStringOffset = JSObject::kHeaderSize;
+  static const int kNextIndexOffset = kStringOffset + kPointerSize;
+  static const int kSize = kNextIndexOffset + kPointerSize;
+
+ private:
+  // Used by verifier
+  DECL_ACCESSORS(index_object, Object)

[Benedikt Meurer, 2016/09/19 04:05:18]

You don't need this, the index() accessor does Smi checking internally. See
comment in objects-debug.cc

[caitp, 2016/09/19 16:03:05]

Done.

+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(JSStringIterator);
+};
 
 // OrderedHashTableIterator is an iterator that iterates over the keys and
 // values of an OrderedHashTable.
 //
 // The iterator has a reference to the underlying OrderedHashTable data,
 // [table], as well as the current [index] the iterator is at.
 //
 // When the OrderedHashTable is rehashed it adds a reference from the old table
 // to the new table as well as storing enough data about the changes so that the
 // iterator [index] can be adjusted accordingly.
@@ skipping 1029 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_