Improve the CallSite constructor

src/messages.cc

 // Copyright 2011 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 "src/messages.h"
 
 #include "src/api.h"
 #include "src/execution.h"
 #include "src/isolate-inl.h"
 #include "src/string-builder.h"
@@ skipping 133 matching lines @@
 
 CallSite::CallSite(Isolate* isolate, Handle<JSObject> call_site_obj)
     : isolate_(isolate) {
   Handle<Object> maybe_function = JSObject::GetDataProperty(
       call_site_obj, isolate->factory()->call_site_function_symbol());
   if (!maybe_function->IsJSFunction()) return;
 
   fun_ = Handle<JSFunction>::cast(maybe_function);
   receiver_ = JSObject::GetDataProperty(
       call_site_obj, isolate->factory()->call_site_receiver_symbol());
-  pos_ = Handle<Smi>::cast(JSObject::GetDataProperty(
-                               call_site_obj,
-                               isolate->factory()->call_site_position_symbol()))
-             ->value();
+  CHECK(JSObject::GetDataProperty(
+            call_site_obj, isolate->factory()->call_site_position_symbol())
+            ->ToInt32(&pos_));
 }
 
 
 Handle<Object> CallSite::GetFileName() {
   Handle<Object> script(fun_->shared()->script(), isolate_);
   if (script->IsScript()) {
     return Handle<Object>(Handle<Script>::cast(script)->name(), isolate_);
   }
   return isolate_->factory()->null_value();
 }
@@ skipping 218 matching lines @@
       builder.AppendCharacter(*c);
     }
   }
 
   return builder.Finish();
 }
 
 
 }  // namespace internal
 }  // namespace v8