Re-enable Object.observe and add enforcement for security invariants.

src/objects.cc

 // Copyright 2013 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.
 
 #include "v8.h"
 
 #include "accessors.h"
 #include "allocation-site-scopes.h"
 #include "api.h"
 #include "arguments.h"
@@ skipping 1939 matching lines @@
   if (object->map()->is_observed() &&
       *name != isolate->heap()->hidden_string()) {
     Handle<Object> old_value = isolate->factory()->the_hole_value();
     EnqueueChangeRecord(object, "add", name, old_value);
   }
 
   return value;
 }
 
 
+Context* JSObject::GetCreationContext() {
+  Object* constructor = this->map()->constructor();
+  JSFunction* function;
+  if (!constructor->IsJSFunction()) {
+    // Functions have null as a constructor,
+    // but any JSFunction knows its context immediately.
+    ASSERT(this->IsJSFunction());

[Toon Verwaest, 2014/05/02 13:48:00]

This assert is done already by JSFunction::cast so is superfluous.

+    function = JSFunction::cast(this);
+  } else {
+    function = JSFunction::cast(constructor);
+  }
+
+  return function->context()->native_context();
+}
+
+
 void JSObject::EnqueueChangeRecord(Handle<JSObject> object,
                                    const char* type_str,
                                    Handle<Name> name,
                                    Handle<Object> old_value) {
   Isolate* isolate = object->GetIsolate();
   HandleScope scope(isolate);
   Handle<String> type = isolate->factory()->InternalizeUtf8String(type_str);
   if (object->IsJSGlobalObject()) {
     object = handle(JSGlobalObject::cast(*object)->global_receiver(), isolate);
   }
@@ skipping 15253 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal