Add Dart_GetSupertype to the dart debugger API so that the dartium

runtime/vm/debugger_api_impl.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 "include/dart_debugger_api.h"
 
+#include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/debugger.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 #define UNWRAP_AND_CHECK_PARAM(type, var, param)                               \
@@ skipping 481 matching lines @@
 
 
 DART_EXPORT Dart_Handle Dart_GetSuperclass(Dart_Handle cls_in) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   UNWRAP_AND_CHECK_PARAM(Class, cls, cls_in);
   return Api::NewHandle(isolate, cls.SuperClass());
 }
 
 
+DART_EXPORT Dart_Handle Dart_GetSupertype(Dart_Handle type_in) {
+  Isolate* isolate = Isolate::Current();
+  DARTSCOPE(isolate);
+
+  UNWRAP_AND_CHECK_PARAM(Type, type, type_in);
+  const Class& cls= Class::Handle(type.type_class());
+  intptr_t num_expected_type_arguments = cls.NumTypeParameters();
+  if (num_expected_type_arguments == 0) {
+    // The super type has no type parameters or it is already instantiated
+    // just return it.
+    const AbstractType& type = AbstractType::Handle(cls.super_type());
+    if (type.IsNull()) {
+      return Dart_Null();
+    }
+    return Api::NewHandle(isolate, type.Canonicalize());
+  }
+  // Set up the type arguments array for the super class type.
+  const Class& super_cls = Class::Handle(cls.SuperClass());
+  num_expected_type_arguments = super_cls.NumTypeParameters();
+  const AbstractTypeArguments& type_args_array =
+      AbstractTypeArguments::Handle(type.arguments());
+  const TypeArguments& super_type_args_array =
+      TypeArguments::Handle(TypeArguments::New(num_expected_type_arguments));
+  AbstractType& type_arg = AbstractType::Handle();
+  for (intptr_t i = 0; i < num_expected_type_arguments; i++) {

[regis, 2013/07/01 16:29:27]

It is not correct to start at index 0. Since you call FinalizeType below, you
only want the type parameters of super_cls, but not those of its own super type.
You should start at index super_cls.NumTypeArguments() -
super_cls.NumTypeParameters(). It will be 0 if super_cls has no super class, but
larger than 0 if super_cls has a type parameterized super class.

Another, maybe simpler, approach would be to truncate the type argument vector
of cls to length super_cls.NumTypeArguments() and canonicalize the new type
(without finalization).  

[siva, 2013/07/01 18:45:15]

As discussed offline I went with the adjustment to start index method as the
more simpler approach to truncate the type argument vector causes issues with
the type not being finalized.

Added a test for this condition to the test case.

On 2013/07/01 16:29:27, regis wrote:

+    type_arg ^= type_args_array.TypeAt(i);
+    super_type_args_array.SetTypeAt(i, type_arg);
+  }
+
+  // Construct the super type object, canonicalize it and return.
+  Type& instantiated_type = Type::Handle(
+      Type::New(super_cls, super_type_args_array, Scanner::kDummyTokenIndex));
+  ASSERT(!instantiated_type.IsNull());
+  instantiated_type ^= ClassFinalizer::FinalizeType(
+      super_cls, instantiated_type, ClassFinalizer::kCanonicalize);
+  return Api::NewHandle(isolate, instantiated_type.raw());
+}
+
+
 DART_EXPORT Dart_Handle Dart_GetClassInfo(
                             intptr_t cls_id,
                             Dart_Handle* class_name,
                             intptr_t* library_id,
                             intptr_t* super_class_id,
                             Dart_Handle* static_fields) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   if (!isolate->class_table()->IsValidIndex(cls_id)) {
     return Api::NewError("%s: %"Pd" is not a valid class id",
@@ skipping 255 matching lines @@
 
 
 DART_EXPORT char* Dart_GetVmStatus(const char* request) {
   if (strncmp(request, "/isolate/", 9) == 0) {
     return Isolate::GetStatus(request);
   }
   return NULL;
 }
 
 }  // namespace dart