Object.observe: implement map bit and functions to access it.

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 13204 matching lines @@
 #undef ELEMENTS_KIND_CHECK_RUNTIME_FUNCTION
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HaveSameMap) {
   ASSERT(args.length() == 2);
   CONVERT_ARG_CHECKED(JSObject, obj1, 0);
   CONVERT_ARG_CHECKED(JSObject, obj2, 1);
   return isolate->heap()->ToBoolean(obj1->map() == obj2->map());
 }
 
+
+RUNTIME_FUNCTION(MaybeObject*, Runtime_IsObserved) {
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSReceiver, obj, 0);
+  return isolate->heap()->ToBoolean(obj->map()->is_observed());
+}
+
+
+RUNTIME_FUNCTION(MaybeObject*, Runtime_SetIsObserved) {
+  ASSERT(args.length() == 2);
+  CONVERT_ARG_CHECKED(JSReceiver, obj, 0);
+  CONVERT_BOOLEAN_ARG_CHECKED(is_observed, 1);
+  if (obj->map()->is_observed() != is_observed) {
+    MaybeObject* maybe = obj->map()->Copy();
+    Map* map;
+    if (!maybe->To<Map>(&map)) return maybe;
+    map->set_is_observed(is_observed);
+    obj->set_map(map);
+  }
+  return isolate->heap()->undefined_value();
+}
+
+
 // ----------------------------------------------------------------------------
 // Implementation of Runtime
 
 #define F(name, number_of_args, result_size)                             \
   { Runtime::k##name, Runtime::RUNTIME, #name,   \
     FUNCTION_ADDR(Runtime_##name), number_of_args, result_size },
 
 
 #define I(name, number_of_args, result_size)                             \
   { Runtime::kInline##name, Runtime::INLINE,     \
@@ skipping 66 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