Allow String.fromCharCodes to work directly on a GrowableObjectArray.

runtime/lib/string.cc

Index: runtime/lib/string.cc
diff --git a/runtime/lib/string.cc b/runtime/lib/string.cc
index 48b81e96fb72e94bebc075241071b3fb7dc97098..df06206e64fb41b55a4ddd10f182322a2342c6fd 100644
--- a/runtime/lib/string.cc
+++ b/runtime/lib/string.cc
@@ -13,10 +13,21 @@
 namespace dart {
 
 DEFINE_NATIVE_ENTRY(StringBase_createFromCodePoints, 1) {
-  GET_NON_NULL_NATIVE_ARGUMENT(Array, a, arguments->NativeArgAt(0));
+  GET_NON_NULL_NATIVE_ARGUMENT(Instance, list, arguments->NativeArgAt(0));
+  bool is_growable = list.IsGrowableObjectArray();
+  if (!is_growable && !list.IsArray()) {
+    const Array& args = Array::Handle(Array::New(1));
+    args.SetAt(0, list);
+    Exceptions::ThrowByType(Exceptions::kArgument, args);
+  }
   // TODO(srdjan): Check that parameterized type is an int.
+  Array& a = Array::Handle(
+      is_growable ? GrowableObjectArray::Cast(list).data()
+                 : Array::Cast(list).raw());
+  intptr_t array_len = is_growable ? GrowableObjectArray::Cast(list).Length()
+                                   : a.Length();

[siva, 2013/03/14 15:56:02]

I would structure this code as:
if (!list.IsGrowableObjectArray() && ! list.IsArray()) {
  ...
  ...
}
Array& a = Array::Handle();
intptr_t array_len = 0;
if (list.IsGrowableObjectArray()) {
  const GrowableObjectArray& ga = GrowableObjectArray::Cast(list);
  a ^= ga.data();
  array_len = ga.Length();
} else {
  a ^= Array::Cast(list).raw();
  array_length = a.Length();
}
....
....

[Lasse Reichstein Nielsen, 2013/03/15 06:58:40]

Much better. Done!

+
   Zone* zone = isolate->current_zone();
-  intptr_t array_len = a.Length();
 
   // Unbox the array and determine the maximum element width.
   bool is_one_byte_string = true;
@@ -49,7 +60,6 @@ DEFINE_NATIVE_ENTRY(StringBase_createFromCodePoints, 1) {
   return TwoByteString::New(utf16_len, utf32_array, array_len, Heap::kNew);
 }
 

[siva, 2013/03/14 15:56:02]

Why remove the blank line here, we normally have 2 blank lines after a function.

[Lasse Reichstein Nielsen, 2013/03/15 06:58:40]

No reason. I moved the body of the method into a helper function at some point,
and then back again. Must have lost a line along the way.

-
 DEFINE_NATIVE_ENTRY(StringBase_substringUnchecked, 3) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_obj, arguments->NativeArgAt(1));