Add optional arguments to NullPointerException so that it can report more information (make it simi…

runtime/lib/object.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 
 namespace dart {
 
 DEFINE_NATIVE_ENTRY(Object_toString, 1) {
   const Instance& instance = Instance::CheckedHandle(arguments->At(0));
   const char* c_str = instance.ToCString();
   arguments->SetReturn(String::Handle(String::New(c_str)));
 }
 
 
 DEFINE_NATIVE_ENTRY(Object_noSuchMethod, 3) {
   const Instance& instance = Instance::CheckedHandle(arguments->At(0));
+  GET_NATIVE_ARGUMENT(String, function_name, arguments->At(1));
+  GET_NATIVE_ARGUMENT(Array, func_args, arguments->At(2));
   if (instance.IsNull()) {
     GrowableArray<const Object*> args;
+    args.Add(&function_name);
+    args.Add(&func_args);
     Exceptions::ThrowByType(Exceptions::kNullPointer, args);
   }
-  GET_NATIVE_ARGUMENT(String, function_name, arguments->At(1));
-  GET_NATIVE_ARGUMENT(Array, func_args, arguments->At(2));
   GrowableArray<const Object*> dart_arguments(3);
   dart_arguments.Add(&instance);
   dart_arguments.Add(&function_name);
   dart_arguments.Add(&func_args);
+
   // Report if a function with same name (but different arguments) has been
   // found.
   Class& instance_class = Class::Handle(instance.clazz());
   Function& function =
       Function::Handle(instance_class.LookupDynamicFunction(function_name));
   while (function.IsNull()) {
     instance_class = instance_class.SuperClass();
     if (instance_class.IsNull()) break;
     function = instance_class.LookupDynamicFunction(function_name);
   }
   if (!function.IsNull()) {
     const int total_num_parameters =
         function.num_fixed_parameters() + function.num_optional_parameters();
     const Array& array = Array::Handle(Array::New(total_num_parameters - 1));
     // Skip receiver.
     for (int i = 1; i < total_num_parameters; i++) {
       array.SetAt(i - 1, String::Handle(function.ParameterNameAt(i)));
     }
     dart_arguments.Add(&array);
   }
   Exceptions::ThrowByType(Exceptions::kNoSuchMethod, dart_arguments);
 }
 
 }  // namespace dart