Implement ArrayBuffer.isView.

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 783 matching lines @@
   if (target_length == 0) return isolate->heap()->undefined_value();
 
   ASSERT(NumberToSize(isolate, source->byte_length()) - target_length >= start);
   uint8_t* source_data = reinterpret_cast<uint8_t*>(source->backing_store());
   uint8_t* target_data = reinterpret_cast<uint8_t*>(target->backing_store());
   CopyBytes(target_data, source_data + start, target_length);
   return isolate->heap()->undefined_value();
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_ArrayBufferIsView) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, object, 0);
+  return object->IsJSArrayBufferView()
+    ? isolate->heap()->true_value()
+    : isolate->heap()->false_value();
+}
+
+
 enum TypedArrayId {
   // arrayIds below should be synchromized with typedarray.js natives.
   ARRAY_ID_UINT8 = 1,
   ARRAY_ID_INT8 = 2,
   ARRAY_ID_UINT16 = 3,
   ARRAY_ID_INT16 = 4,
   ARRAY_ID_UINT32 = 5,
   ARRAY_ID_INT32 = 6,
   ARRAY_ID_FLOAT32 = 7,
   ARRAY_ID_FLOAT64 = 8,
@@ skipping 13995 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal