Harden %SetIsObserved with RUNTIME_ASSERTs

src/runtime.cc

 // 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.
 
 #include <stdlib.h>
 #include <limits>
 
 #include "v8.h"
 
 #include "accessors.h"
@@ skipping 14837 matching lines @@
   CONVERT_ARG_CHECKED(JSReceiver, obj, 0);
   ASSERT(!obj->IsJSGlobalProxy() || !obj->map()->is_observed());
   return isolate->heap()->ToBoolean(obj->map()->is_observed());
 }
 
 
 RUNTIME_FUNCTION(Runtime_SetIsObserved) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, obj, 0);
-  ASSERT(!obj->IsJSGlobalProxy());
-  if (obj->IsJSProxy())
-    return isolate->heap()->undefined_value();
+  RUNTIME_ASSERT(!obj->IsJSGlobalProxy());
+  if (obj->IsJSProxy()) return isolate->heap()->undefined_value();
+  RUNTIME_ASSERT(!obj->map()->is_observed());
 
   ASSERT(obj->IsJSObject());
   JSObject::SetObserved(Handle<JSObject>::cast(obj));
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_SetMicrotaskPending) {
   SealHandleScope shs(isolate);
   ASSERT(args.length() == 1);
@@ skipping 344 matching lines @@
   }
   return NULL;
 }
 
 
 const Runtime::Function* Runtime::FunctionForId(Runtime::FunctionId id) {
   return &(kIntrinsicFunctions[static_cast<int>(id)]);
 }
 
 } }  // namespace v8::internal