Reland of "Remove ExternalArray, derived types, and element kinds"

src/objects.h

 // Copyright 2012 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 75 matching lines @@
 //           - OrderedHashSet
 //           - OrderedHashMap
 //         - Context
 //         - TypeFeedbackVector
 //         - JSFunctionResultCache
 //         - ScopeInfo
 //         - TransitionArray
 //         - ScriptContextTable
 //         - WeakFixedArray
 //       - FixedDoubleArray
-//       - ExternalArray
-//         - ExternalUint8ClampedArray
-//         - ExternalInt8Array
-//         - ExternalUint8Array
-//         - ExternalInt16Array
-//         - ExternalUint16Array
-//         - ExternalInt32Array
-//         - ExternalUint32Array
-//         - ExternalFloat32Array
 //     - Name
 //       - String
 //         - SeqString
 //           - SeqOneByteString
 //           - SeqTwoByteString
 //         - SlicedString
 //         - ConsString
 //         - ExternalString
 //           - ExternalOneByteString
 //           - ExternalTwoByteString
@@ skipping 270 matching lines @@
   V(ODDBALL_TYPE)                                               \
   V(CELL_TYPE)                                                  \
   V(PROPERTY_CELL_TYPE)                                         \
                                                                 \
   V(HEAP_NUMBER_TYPE)                                           \
   V(MUTABLE_HEAP_NUMBER_TYPE)                                   \
   V(FOREIGN_TYPE)                                               \
   V(BYTE_ARRAY_TYPE)                                            \
   V(BYTECODE_ARRAY_TYPE)                                        \
   V(FREE_SPACE_TYPE)                                            \
-  /* Note: the order of these external array */                 \
-  /* types is relied upon in */                                 \
-  /* Object::IsExternalArray(). */                              \
-  V(EXTERNAL_INT8_ARRAY_TYPE)                                   \
-  V(EXTERNAL_UINT8_ARRAY_TYPE)                                  \
-  V(EXTERNAL_INT16_ARRAY_TYPE)                                  \
-  V(EXTERNAL_UINT16_ARRAY_TYPE)                                 \
-  V(EXTERNAL_INT32_ARRAY_TYPE)                                  \
-  V(EXTERNAL_UINT32_ARRAY_TYPE)                                 \
-  V(EXTERNAL_FLOAT32_ARRAY_TYPE)                                \
-  V(EXTERNAL_FLOAT64_ARRAY_TYPE)                                \
-  V(EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE)                          \
                                                                 \
   V(FIXED_INT8_ARRAY_TYPE)                                      \
   V(FIXED_UINT8_ARRAY_TYPE)                                     \
   V(FIXED_INT16_ARRAY_TYPE)                                     \
   V(FIXED_UINT16_ARRAY_TYPE)                                    \
   V(FIXED_INT32_ARRAY_TYPE)                                     \
   V(FIXED_UINT32_ARRAY_TYPE)                                    \
   V(FIXED_FLOAT32_ARRAY_TYPE)                                   \
   V(FIXED_FLOAT64_ARRAY_TYPE)                                   \
   V(FIXED_UINT8_CLAMPED_ARRAY_TYPE)                             \
@@ skipping 265 matching lines @@
 
   // "Data", objects that cannot contain non-map-word pointers to heap
   // objects.
   HEAP_NUMBER_TYPE,
   MUTABLE_HEAP_NUMBER_TYPE,
   FLOAT32X4_TYPE,  // FIRST_SIMD_TYPE, LAST_SIMD_TYPE
   FOREIGN_TYPE,
   BYTE_ARRAY_TYPE,
   BYTECODE_ARRAY_TYPE,
   FREE_SPACE_TYPE,
-  EXTERNAL_INT8_ARRAY_TYPE,  // FIRST_EXTERNAL_ARRAY_TYPE
-  EXTERNAL_UINT8_ARRAY_TYPE,
-  EXTERNAL_INT16_ARRAY_TYPE,
-  EXTERNAL_UINT16_ARRAY_TYPE,
-  EXTERNAL_INT32_ARRAY_TYPE,
-  EXTERNAL_UINT32_ARRAY_TYPE,
-  EXTERNAL_FLOAT32_ARRAY_TYPE,
-  EXTERNAL_FLOAT64_ARRAY_TYPE,
-  EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE,  // LAST_EXTERNAL_ARRAY_TYPE
   FIXED_INT8_ARRAY_TYPE,              // FIRST_FIXED_TYPED_ARRAY_TYPE
   FIXED_UINT8_ARRAY_TYPE,
   FIXED_INT16_ARRAY_TYPE,
   FIXED_UINT16_ARRAY_TYPE,
   FIXED_INT32_ARRAY_TYPE,
   FIXED_UINT32_ARRAY_TYPE,
   FIXED_FLOAT32_ARRAY_TYPE,
   FIXED_FLOAT64_ARRAY_TYPE,
   FIXED_UINT8_CLAMPED_ARRAY_TYPE,  // LAST_FIXED_TYPED_ARRAY_TYPE
   FIXED_DOUBLE_ARRAY_TYPE,
@@ skipping 62 matching lines @@
   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,
   FIRST_NONSTRING_TYPE = SYMBOL_TYPE,
   // Boundaries for testing for a SIMD type.
   FIRST_SIMD_TYPE = FLOAT32X4_TYPE,
   LAST_SIMD_TYPE = FLOAT32X4_TYPE,
-  // Boundaries for testing for an external array.
-  FIRST_EXTERNAL_ARRAY_TYPE = EXTERNAL_INT8_ARRAY_TYPE,
-  LAST_EXTERNAL_ARRAY_TYPE = EXTERNAL_UINT8_CLAMPED_ARRAY_TYPE,
   // Boundaries for testing for a fixed typed array.
   FIRST_FIXED_TYPED_ARRAY_TYPE = FIXED_INT8_ARRAY_TYPE,
   LAST_FIXED_TYPED_ARRAY_TYPE = FIXED_UINT8_CLAMPED_ARRAY_TYPE,
   // Boundary for promotion to old space.
   LAST_DATA_TYPE = FILLER_TYPE,
   // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy).
   // Note that there is no range for JSObject or JSProxy, since their subtypes
   // are not continuous in this enum! The enum ranges instead reflect the
   // external class names, where proxies are treated as either ordinary objects,
   // or functions.
   FIRST_JS_RECEIVER_TYPE = JS_FUNCTION_PROXY_TYPE,
   LAST_JS_RECEIVER_TYPE = LAST_TYPE,
   // Boundaries for testing the types represented as JSObject
   FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE,
   LAST_JS_OBJECT_TYPE = LAST_TYPE,
   // Boundaries for testing the types represented as JSProxy
   FIRST_JS_PROXY_TYPE = JS_FUNCTION_PROXY_TYPE,
   LAST_JS_PROXY_TYPE = JS_PROXY_TYPE,
   // Boundaries for testing whether the type is a JavaScript object.
   FIRST_SPEC_OBJECT_TYPE = FIRST_JS_RECEIVER_TYPE,
   LAST_SPEC_OBJECT_TYPE = LAST_JS_RECEIVER_TYPE,
   // Boundaries for testing the types for which typeof is "object".
   FIRST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_PROXY_TYPE,
   LAST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_REGEXP_TYPE,
   // Note that the types for which typeof is "function" are not continuous.
   // Define this so that we can put assertions on discrete checks.
   NUM_OF_CALLABLE_SPEC_OBJECT_TYPES = 2
 };
 
-const int kExternalArrayTypeCount =
-    LAST_EXTERNAL_ARRAY_TYPE - FIRST_EXTERNAL_ARRAY_TYPE + 1;
-
 STATIC_ASSERT(JS_OBJECT_TYPE == Internals::kJSObjectType);
 STATIC_ASSERT(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType);
 STATIC_ASSERT(ODDBALL_TYPE == Internals::kOddballType);
 STATIC_ASSERT(FOREIGN_TYPE == Internals::kForeignType);
 
 
 #define FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(V) \
   V(FAST_ELEMENTS_SUB_TYPE)                   \
   V(DICTIONARY_ELEMENTS_SUB_TYPE)             \
   V(FAST_PROPERTIES_SUB_TYPE)                 \
@@ skipping 98 matching lines @@
   V(ExternalString)                \
   V(ConsString)                    \
   V(SlicedString)                  \
   V(ExternalTwoByteString)         \
   V(ExternalOneByteString)         \
   V(SeqTwoByteString)              \
   V(SeqOneByteString)              \
   V(InternalizedString)            \
   V(Symbol)                        \
                                    \
-  V(ExternalArray)                 \
-  V(ExternalInt8Array)             \
-  V(ExternalUint8Array)            \
-  V(ExternalInt16Array)            \
-  V(ExternalUint16Array)           \
-  V(ExternalInt32Array)            \
-  V(ExternalUint32Array)           \
-  V(ExternalFloat32Array)          \
-  V(ExternalFloat64Array)          \
-  V(ExternalUint8ClampedArray)     \
   V(FixedTypedArrayBase)           \
   V(FixedUint8Array)               \
   V(FixedInt8Array)                \
   V(FixedUint16Array)              \
   V(FixedInt16Array)               \
   V(FixedUint32Array)              \
   V(FixedInt32Array)               \
   V(FixedFloat32Array)             \
   V(FixedFloat64Array)             \
   V(FixedUint8ClampedArray)        \
@@ skipping 809 matching lines @@
   //
   // In the fast mode elements is a FixedArray and so each element can
   // be quickly accessed. This fact is used in the generated code. The
   // elements array can have one of three maps in this mode:
   // fixed_array_map, sloppy_arguments_elements_map or
   // fixed_cow_array_map (for copy-on-write arrays). In the latter case
   // the elements array may be shared by a few objects and so before
   // writing to any element the array must be copied. Use
   // EnsureWritableFastElements in this case.
   //
-  // In the slow mode the elements is either a NumberDictionary, an
-  // ExternalArray, or a FixedArray parameter map for a (sloppy)
-  // arguments object.
+  // In the slow mode the elements is either a NumberDictionary, a
+  // FixedArray parameter map for a (sloppy) arguments object.
   DECL_ACCESSORS(elements, FixedArrayBase)
   inline void initialize_elements();
   static void ResetElements(Handle<JSObject> object);
   static inline void SetMapAndElements(Handle<JSObject> object,
                                        Handle<Map> map,
                                        Handle<FixedArrayBase> elements);
   inline ElementsKind GetElementsKind();
   ElementsAccessor* GetElementsAccessor();
   // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
   inline bool HasFastSmiElements();
   // Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
   inline bool HasFastObjectElements();
   // Returns true if an object has elements of FAST_ELEMENTS or
   // FAST_SMI_ONLY_ELEMENTS.
   inline bool HasFastSmiOrObjectElements();
   // Returns true if an object has any of the fast elements kinds.
   inline bool HasFastElements();
   // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
   // ElementsKind.
   inline bool HasFastDoubleElements();
   // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
   // ElementsKind.
   inline bool HasFastHoleyElements();
   inline bool HasSloppyArgumentsElements();
   inline bool HasDictionaryElements();
 
-  inline bool HasExternalUint8ClampedElements();
-  inline bool HasExternalArrayElements();
-  inline bool HasExternalInt8Elements();
-  inline bool HasExternalUint8Elements();
-  inline bool HasExternalInt16Elements();
-  inline bool HasExternalUint16Elements();
-  inline bool HasExternalInt32Elements();
-  inline bool HasExternalUint32Elements();
-  inline bool HasExternalFloat32Elements();
-  inline bool HasExternalFloat64Elements();
-
   inline bool HasFixedTypedArrayElements();
 
   inline bool HasFixedUint8ClampedElements();
   inline bool HasFixedArrayElements();
   inline bool HasFixedInt8Elements();
   inline bool HasFixedUint8Elements();
   inline bool HasFixedInt16Elements();
   inline bool HasFixedUint16Elements();
   inline bool HasFixedInt32Elements();
   inline bool HasFixedUint32Elements();
@@ skipping 2502 matching lines @@
   V(Int8, int8, INT8, int8_t, 1)                                               \
   V(Uint16, uint16, UINT16, uint16_t, 2)                                       \
   V(Int16, int16, INT16, int16_t, 2)                                           \
   V(Uint32, uint32, UINT32, uint32_t, 4)                                       \
   V(Int32, int32, INT32, int32_t, 4)                                           \
   V(Float32, float32, FLOAT32, float, 4)                                       \
   V(Float64, float64, FLOAT64, double, 8)                                      \
   V(Uint8Clamped, uint8_clamped, UINT8_CLAMPED, uint8_t, 1)
 
 
-
-// An ExternalArray represents a fixed-size array of primitive values
-// which live outside the JavaScript heap. Its subclasses are used to
-// implement the CanvasArray types being defined in the WebGL
-// specification. As of this writing the first public draft is not yet
-// available, but Khronos members can access the draft at:
-//   https://cvs.khronos.org/svn/repos/3dweb/trunk/doc/spec/WebGL-spec.html
-//
-// The semantics of these arrays differ from CanvasPixelArray.
-// Out-of-range values passed to the setter are converted via a C
-// cast, not clamping. Out-of-range indices cause exceptions to be
-// raised rather than being silently ignored.
-class ExternalArray: public FixedArrayBase {
- public:
-  inline bool is_the_hole(int index) { return false; }
-
-  // [external_pointer]: The pointer to the external memory area backing this
-  // external array.
-  DECL_ACCESSORS(external_pointer, void)  // Pointer to the data store.
-
-  DECLARE_CAST(ExternalArray)
-
-  // Maximal acceptable length for an external array.
-  static const int kMaxLength = 0x3fffffff;
-
-  // ExternalArray headers are not quadword aligned.
-  static const int kExternalPointerOffset =
-      POINTER_SIZE_ALIGN(FixedArrayBase::kLengthOffset + kPointerSize);
-  static const int kSize = kExternalPointerOffset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalArray);
-};
-
-
-// A ExternalUint8ClampedArray represents a fixed-size byte array with special
-// semantics used for implementing the CanvasPixelArray object. Please see the
-// specification at:
-
-// http://www.whatwg.org/specs/web-apps/current-work/
-//                      multipage/the-canvas-element.html#canvaspixelarray
-// In particular, write access clamps the value written to 0 or 255 if the
-// value written is outside this range.
-class ExternalUint8ClampedArray: public ExternalArray {
- public:
-  inline uint8_t* external_uint8_clamped_pointer();
-
-  // Setter and getter.
-  inline uint8_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalUint8ClampedArray> array,
-                                   int index);
-  inline void set(int index, uint8_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined and clamps the converted value between 0 and 255.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalUint8ClampedArray)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalUint8ClampedArray)
-  DECLARE_VERIFIER(ExternalUint8ClampedArray)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint8ClampedArray);
-};
-
-
-class ExternalInt8Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline int8_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalInt8Array> array, int index);
-  inline void set(int index, int8_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalInt8Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalInt8Array)
-  DECLARE_VERIFIER(ExternalInt8Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt8Array);
-};
-
-
-class ExternalUint8Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline uint8_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalUint8Array> array, int index);
-  inline void set(int index, uint8_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalUint8Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalUint8Array)
-  DECLARE_VERIFIER(ExternalUint8Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint8Array);
-};
-
-
-class ExternalInt16Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline int16_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalInt16Array> array, int index);
-  inline void set(int index, int16_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalInt16Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalInt16Array)
-  DECLARE_VERIFIER(ExternalInt16Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt16Array);
-};
-
-
-class ExternalUint16Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline uint16_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalUint16Array> array,
-                                   int index);
-  inline void set(int index, uint16_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalUint16Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalUint16Array)
-  DECLARE_VERIFIER(ExternalUint16Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint16Array);
-};
-
-
-class ExternalInt32Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline int32_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalInt32Array> array, int index);
-  inline void set(int index, int32_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalInt32Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalInt32Array)
-  DECLARE_VERIFIER(ExternalInt32Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalInt32Array);
-};
-
-
-class ExternalUint32Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline uint32_t get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalUint32Array> array,
-                                   int index);
-  inline void set(int index, uint32_t value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalUint32Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalUint32Array)
-  DECLARE_VERIFIER(ExternalUint32Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUint32Array);
-};
-
-
-class ExternalFloat32Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline float get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalFloat32Array> array,
-                                   int index);
-  inline void set(int index, float value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalFloat32Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalFloat32Array)
-  DECLARE_VERIFIER(ExternalFloat32Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloat32Array);
-};
-
-
-class ExternalFloat64Array: public ExternalArray {
- public:
-  // Setter and getter.
-  inline double get_scalar(int index);
-  static inline Handle<Object> get(Handle<ExternalFloat64Array> array,
-                                   int index);
-  inline void set(int index, double value);
-
-  // This accessor applies the correct conversion from Smi, HeapNumber
-  // and undefined.
-  void SetValue(uint32_t index, Object* value);
-
-  DECLARE_CAST(ExternalFloat64Array)
-
-  // Dispatched behavior.
-  DECLARE_PRINTER(ExternalFloat64Array)
-  DECLARE_VERIFIER(ExternalFloat64Array)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloat64Array);
-};
-
-
 class FixedTypedArrayBase: public FixedArrayBase {
  public:
-  // [base_pointer]: For now, points to the FixedTypedArrayBase itself.
+  // [base_pointer]: Either points to the FixedTypedArrayBase itself or nullptr.
   DECL_ACCESSORS(base_pointer, Object)
 
-  // [external_pointer]: For now, contains the offset between base_pointer and
-  // the start of the data.
+  // [external_pointer]: Contains the offset between base_pointer and the start
+  // of the data. If the base_pointer is a nullptr, the external_pointer
+  // therefore points to the actual backing store.
   DECL_ACCESSORS(external_pointer, void)
 
   // Dispatched behavior.
   inline void FixedTypedArrayBaseIterateBody(ObjectVisitor* v);
 
   template <typename StaticVisitor>
   inline void FixedTypedArrayBaseIterateBody();
 
   DECLARE_CAST(FixedTypedArrayBase)
 
@@ skipping 1130 matching lines @@
   }
 
   inline bool has_fast_elements() {
     return IsFastElementsKind(elements_kind());
   }
 
   inline bool has_sloppy_arguments_elements() {
     return IsSloppyArgumentsElements(elements_kind());
   }
 
-  inline bool has_external_array_elements() {
-    return IsExternalArrayElementsKind(elements_kind());
-  }
-
   inline bool has_fixed_typed_array_elements() {
     return IsFixedTypedArrayElementsKind(elements_kind());
   }
 
   inline bool has_dictionary_elements() {
     return IsDictionaryElementsKind(elements_kind());
   }
 
   static bool IsValidElementsTransition(ElementsKind from_kind,
                                         ElementsKind to_kind);
@@ skipping 5094 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_