Fix dartbug.com/17261

runtime/vm/object.cc

 // Copyright (c) 2012, 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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 2000 matching lines @@
 void Class::set_library(const Library& value) const {
   StorePointer(&raw_ptr()->library_, value.raw());
 }
 
 
 void Class::set_type_parameters(const TypeArguments& value) const {
   StorePointer(&raw_ptr()->type_parameters_, value.raw());
 }
 
 
-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();
 }
 
 
 intptr_t Class::NumOwnTypeArguments() const {
   // Return cached value if already calculated.
   if (num_own_type_arguments() != kUnknownNumTypeArguments) {
     return num_own_type_arguments();
   }
   Isolate* isolate = Isolate::Current();
@@ skipping 10787 matching lines @@
   }
   if (type_class() != other_type.type_class()) {
     return false;
   }
   if (!IsFinalized() || !other_type.IsFinalized()) {
     return false;
   }
   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;
   }
   const intptr_t num_type_args = cls.NumTypeArguments();
   const intptr_t from_index = num_type_args - num_type_params;
   const TypeArguments& type_args = TypeArguments::Handle(arguments());
   const TypeArguments& other_type_args = TypeArguments::Handle(
       other_type.arguments());
   if (type_args.IsNull()) {
@@ skipping 3458 matching lines @@
     obj = source.At(i);
     result.SetAt(i, obj);
   }
   return result.raw();
 }
 
 
 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;
 
   // Update the size in the header field and length of the array object.
   uword tags = array.raw_ptr()->tags_;
   ASSERT(kArrayCid == RawObject::ClassIdTag::decode(tags));
   tags = RawObject::SizeTag::update(used_size, tags);
   array.raw_ptr()->tags_ = tags;
   array.SetLength(used_len);
@@ skipping 1141 matching lines @@
   return "_MirrorReference";
 }
 
 
 void MirrorReference::PrintToJSONStream(JSONStream* stream, bool ref) const {
   Instance::PrintToJSONStream(stream, ref);
 }
 
 
 }  // namespace dart