Fix dartbug.com/17261

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 33253)
+++ runtime/vm/object.cc	(working copy)
@@ -2018,14 +2018,16 @@
 }
 
 
-intptr_t Class::NumTypeParameters() const {
+intptr_t Class::NumTypeParameters(Isolate* isolate) const {
   if (IsMixinApplication() && !is_mixin_type_applied()) {
     ClassFinalizer::ApplyMixinType(*this);
   }
   if (type_parameters() == TypeArguments::null()) {
     return 0;
   }
-  const TypeArguments& type_params = TypeArguments::Handle(type_parameters());
+  ReusableHandleScope reused_handles(isolate);
+  TypeArguments& type_params = reused_handles.TypeArgumentsHandle();
+  type_params = type_parameters();
   return type_params.Length();
 }
 
@@ -12833,8 +12835,9 @@
   if (arguments() == other_type.arguments()) {
     return true;
   }
-  const Class& cls = Class::Handle(type_class());
-  const intptr_t num_type_params = cls.NumTypeParameters();
+  Isolate* isolate = Isolate::Current();

[srdjan, 2014/03/04 17:57:07]

Why not move this up and use it for all handles?

[siva, 2014/03/04 18:02:10]

I would not move it up as there seem to be number of escapes from the function
in the code above which do not need an Isolate and by moving this up we would
unnecessarily get the isolate in those cases.


On 2014/03/04 17:57:07, srdjan wrote:

[Ivan Posva, 2014/03/04 18:08:59]

As Siva says, but added it to the handle allocations below.

+  const Class& cls = Class::Handle(isolate, type_class());
+  const intptr_t num_type_params = cls.NumTypeParameters(isolate);

[regis, 2014/03/04 17:41:41]

Passing the isolate looks really strange to me. Why only here and not everywhere
else? Did it show on the profile?

[Ivan Posva, 2014/03/04 18:08:59]

Yes.

   if (num_type_params == 0) {
     // Shortcut unnecessary handle allocation below.
     return true;
@@ -16313,12 +16316,18 @@
 RawArray* Array::MakeArray(const GrowableObjectArray& growable_array) {
   ASSERT(!growable_array.IsNull());
   intptr_t used_len = growable_array.Length();
-  if (used_len == 0) {
+  // Get the type arguments and prepare to copy them.
+  const TypeArguments& type_arguments =
+      TypeArguments::Handle(growable_array.GetTypeArguments());
+  if ((used_len == 0) && (type_arguments.IsNull())) {
+    // This is a raw List (as in no type arguments), so we can return the
+    // simple empty array.
     return Object::empty_array().raw();
   }
   intptr_t capacity_len = growable_array.Capacity();
   Isolate* isolate = Isolate::Current();
   const Array& array = Array::Handle(isolate, growable_array.data());
+  array.SetTypeArguments(type_arguments);
   intptr_t capacity_size = Array::InstanceSize(capacity_len);
   intptr_t used_size = Array::InstanceSize(used_len);
   NoGCScope no_gc;