Report NullPointerException when we try to construct a regular expression

vm/code_generator.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/code_generator.h"
 
 #include "vm/code_index_table.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
@@ skipping 584 matching lines @@
   }
   if (!result.IsSmi()) {
     const Class& cls = Class::Handle(result.clazz());
     ASSERT(!cls.IsNull());
     function = cls.signature_function();
     if (!function.IsNull()) {
       arguments.SetReturn(result);
       return;  // Return closure object.
     }
   }
-  Exceptions::ThrowByType(Exceptions::kObjectNotClosure, invoke_arguments);
+  Exceptions::ThrowByType(
+      result.IsNull() ? Exceptions::kNullPointer :
+                        Exceptions::kObjectNotClosure,
+      invoke_arguments);
 }
 
 
 // Invoke Implicit Closure function.
 // Arg0: closure object.
 // Arg1: arguments descriptor (originally passed as dart instance invocation).
 // Arg2: arguments array (originally passed to dart instance invocation).
 DEFINE_RUNTIME_ENTRY(InvokeImplicitClosureFunction, 3) {
   ASSERT(arguments.Count() ==
          kInvokeImplicitClosureFunctionRuntimeEntry.argument_count());
@@ skipping 103 matching lines @@
 }
 
 
 // Report that an object is not a closure.
 // Arg0: non-closure object.
 // Arg1: arguments array.
 DEFINE_RUNTIME_ENTRY(ReportObjectNotClosure, 2) {
   ASSERT(arguments.Count() ==
          kReportObjectNotClosureRuntimeEntry.argument_count());
   const Instance& bad_closure = Instance::CheckedHandle(arguments.At(0));
+  if (bad_closure.IsNull()) {
+    GrowableArray<const Object*> args;
+    Exceptions::ThrowByType(Exceptions::kNullPointer, args);
+  }
   // const Array& arguments = Array::CheckedHandle(arguments.At(1));
   OS::PrintErr("object '%s' is not a closure\n", bad_closure.ToCString());
   GrowableArray<const Object*> args;
   Exceptions::ThrowByType(Exceptions::kObjectNotClosure, args);
 }
 
 
 DEFINE_RUNTIME_ENTRY(ClosureArgumentMismatch, 0) {
   ASSERT(arguments.Count() ==
          kClosureArgumentMismatchRuntimeEntry.argument_count());
@@ skipping 204 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart