Rename GET_NATIVE_ARGUMENT macro to GET_NON_NULL_NATIVE_ARGUMENT.

runtime/vm/native_entry.h

Index: runtime/vm/native_entry.h
===================================================================
--- runtime/vm/native_entry.h	(revision 15830)
+++ runtime/vm/native_entry.h	(working copy)
@@ -51,9 +51,9 @@
                                     NativeArguments* arguments)
 
 
-// Natives should throw an exception if an illegal argument is passed.
+// Natives should throw an exception if an illegal argument or null is passed.
 // type name = value.
-#define GET_NATIVE_ARGUMENT(type, name, value)                                 \
+#define GET_NON_NULL_NATIVE_ARGUMENT(type, name, value)                        \
   const Instance& __##name##_instance__ =                                      \
       Instance::CheckedHandle(isolate, value);                                 \
   if (!__##name##_instance__.Is##type()) {                                     \
@@ -64,7 +64,22 @@
   const type& name = type::Cast(__##name##_instance__);
 
 
+// Natives should throw an exception if an illegal argument is passed.
+// type name = value.
+#define GET_NATIVE_ARGUMENT(type, name, value)                                 \
+  const Instance& __##name##_instance__ =                                      \
+      Instance::CheckedHandle(isolate, value);                                 \
+  type& name = type::Handle(isolate);                                          \
+  if (!__##name##_instance__.IsNull()) {                                       \
+    if (!__##name##_instance__.Is##type()) {                                   \
+      GrowableArray<const Object*> __args__;                                   \
+      __args__.Add(&__##name##_instance__);                                    \
+      Exceptions::ThrowByType(Exceptions::kArgument, __args__);                \
+    }                                                                          \
+    name ^= value;                                                             \

[siva, 2012/12/07 02:28:40]

Shouldn't the assignment above be done irrespective of whether it is NULL or non
NULL.

Otherwise the vtable entry in the NULL case would still point
to  Instance and if the native code did an Is<type> call for whatever reason it
would return false.

[regis, 2012/12/10 17:58:42]

Done.

+  }
 
+
 // Helper class for resolving and handling native functions.
 class NativeEntry : public AllStatic {
  public: