Never return a Dart_Handle on a dart::Class from the embedding API.

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
@@ skipping 62 matching lines @@
       return instance.raw();
     }
   }
   return Instance::null();
 }
 
 
 Dart_Handle Api::NewHandle(Isolate* isolate, RawObject* raw) {
   LocalHandles* local_handles = Api::TopScope(isolate)->local_handles();
   ASSERT(local_handles != NULL);
+  ASSERT(!raw->IsRawClass());
   LocalHandle* ref = local_handles->AllocateHandle();
   ref->set_raw(raw);
   return reinterpret_cast<Dart_Handle>(ref);
 }
 
 
 RawObject* Api::UnwrapHandle(Dart_Handle object) {
 #if defined(DEBUG)
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate != NULL);
@@ skipping 1204 matching lines @@
   return Api::ClassId(object) == kLibraryCid;
 }
 
 
 DART_EXPORT bool Dart_IsType(Dart_Handle handle) {
   TRACE_API_CALL(CURRENT_FUNC);
   return Api::ClassId(handle) == kTypeCid;
 }
 
 
-DART_EXPORT bool Dart_IsClass(Dart_Handle handle) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(handle));
-  return obj.IsClass();
-}
-
-
 DART_EXPORT bool Dart_IsFunction(Dart_Handle handle) {
   TRACE_API_CALL(CURRENT_FUNC);
   return Api::ClassId(handle) == kFunctionCid;
 }
 
 
 DART_EXPORT bool Dart_IsVariable(Dart_Handle handle) {
   TRACE_API_CALL(CURRENT_FUNC);
   return Api::ClassId(handle) == kFieldCid;
 }
@@ skipping 24 matching lines @@
   if (obj.IsNull()) {
     return Api::NewHandle(isolate, isolate->object_store()->null_type());
   }
   if (!obj.IsInstance()) {
     RETURN_TYPE_ERROR(isolate, instance, Instance);
   }
   const Type& type = Type::Handle(Instance::Cast(obj).GetType());
   return Api::NewHandle(isolate, type.Canonicalize());
 }
 
-// TODO(asiva): Deprecate this method.
-DART_EXPORT Dart_Handle Dart_InstanceGetClass(Dart_Handle instance) {
-  Isolate* isolate = Isolate::Current();
-  DARTSCOPE(isolate);
-  const Instance& obj = Api::UnwrapInstanceHandle(isolate, instance);
-  if (obj.IsNull()) {
-    RETURN_TYPE_ERROR(isolate, instance, Instance);
-  }
-  return Api::NewHandle(isolate, obj.clazz());
-}
-
 
 // --- Numbers, Integers and Doubles ----
 
 DART_EXPORT Dart_Handle Dart_IntegerFitsIntoInt64(Dart_Handle integer,
                                                   bool* fits) {
   // Fast path for Smis and Mints.
   Isolate* isolate = Isolate::Current();
   CHECK_ISOLATE(isolate);
   intptr_t class_id = Api::ClassId(integer);
   if (class_id == kSmiCid || class_id == kMintCid) {
@@ skipping 1454 matching lines @@
   CHECK_CALLBACK_STATE(isolate);
   Object& result = Object::Handle(isolate);
 
   if (number_of_arguments < 0) {
     return Api::NewError(
         "%s expects argument 'number_of_arguments' to be non-negative.",
         CURRENT_FUNC);
   }
 
   // Get the class to instantiate.
   result = Api::UnwrapHandle(type);

[siva, 2013/09/19 03:16:58]

You should be able to use 
const Type& type_obj = Api::UnwrapTypeHandle(type);
(this will return a NULL if the object is not a type and the subsequent check
will report the error. You don't have to then again do the check
if (result.IsType()) further down.

   if (result.IsNull()) {
     RETURN_TYPE_ERROR(isolate, type, Type);
   }
   Class& cls = Class::Handle(isolate);
   AbstractTypeArguments& type_arguments =
       AbstractTypeArguments::Handle(isolate);
 
   if (result.IsType()) {
     cls = Type::Cast(result).type_class();

[siva, 2013/09/19 03:16:58]

cls = type_obj.type_class();

     type_arguments = Type::Cast(result).arguments();
-  } else if (result.IsClass()) {
-    // For backwards compatibility we allow class objects to be passed in
-    // for now. This needs to be removed once all code that uses class
-    // objects to invoke Dart_New is removed.
-    cls ^= result.raw();
-    type_arguments = Type::Handle(cls.RareType()).arguments();
   } else {
     RETURN_TYPE_ERROR(isolate, type, Type);
   }
 
   String& base_constructor_name = String::Handle();
   base_constructor_name = cls.Name();
 
   // And get the name of the constructor to invoke.
   String& dot_name = String::Handle(isolate);
   result = Api::UnwrapHandle(constructor_name);
@@ skipping 87 matching lines @@
     new_object ^= result.raw();
   }
   return Api::NewHandle(isolate, new_object.raw());
 }
 
 
 DART_EXPORT Dart_Handle Dart_Allocate(Dart_Handle type) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   CHECK_CALLBACK_STATE(isolate);
   const Object& result = Object::Handle(isolate, Api::UnwrapHandle(type));

[siva, 2013/09/19 03:16:58]

Ditto comment about
const Type& result = Api::UnwrapTypeHandle(type);

 
   // Get the class to instantiate.
   if (result.IsNull()) {
     RETURN_TYPE_ERROR(isolate, type, Type);
   }
   Class& cls = Class::Handle(isolate);
   if (result.IsType()) {
     cls = Type::Cast(result).type_class();

[siva, 2013/09/19 03:16:58]

const Class& cls = Class::Handle(isolate, result.type_class());

-  } else if (result.IsClass()) {
-    // For backwards compatibility we allow class objects to be passed in
-    // for now. This needs to be removed once all code that uses class
-    // objects to invoke Dart_New is removed.
-    cls ^= result.raw();
   } else {
     RETURN_TYPE_ERROR(isolate, type, Type);
   }
 
   // Allocate an object for the given class.
   return Api::NewHandle(isolate, Instance::New(cls));
 }
 
 
 DART_EXPORT Dart_Handle Dart_Invoke(Dart_Handle target,
@@ skipping 31 matching lines @@
         return Api::NewHandle(isolate, arg.raw());
       } else {
         return Api::NewError(
             "%s expects arguments[%d] to be an Instance handle.",
             CURRENT_FUNC, i);
       }
     }
     args.SetAt((i + num_receiver), arg);
   }
 
-  if (obj.IsType() || obj.IsClass()) {
+  if (obj.IsType()) {
     // Finalize all classes.
     Dart_Handle state = Api::CheckIsolateState(isolate);
     if (::Dart_IsError(state)) {
       return state;
     }
 
-    // For backwards compatibility we allow class objects to be passed in
-    // for now. This needs to be removed once all code that uses class
-    // objects to invoke Dart_Invoke is removed.
-    Class& cls = Class::Handle();
-    if (obj.IsType()) {
-      cls = Type::Cast(obj).type_class();
-    } else {
-      cls = Class::Cast(obj).raw();
-    }
+    const Class& cls = Class::Handle(isolate, Type::Cast(obj).type_class());
     const Function& function = Function::Handle(
         isolate,
         Resolver::ResolveStatic(cls,
                                 function_name,
                                 number_of_arguments,
                                 Object::empty_array(),
                                 Resolver::kIsQualified));
     if (function.IsNull()) {
       const String& cls_name = String::Handle(isolate, cls.Name());
       return Api::NewError("%s: did not find static method '%s.%s'.",
@@ skipping 26 matching lines @@
   } else if (obj.IsLibrary()) {
     // Check whether class finalization is needed.
     const Library& lib = Library::Cast(obj);
 
     // Finalize all classes if needed.
     Dart_Handle state = Api::CheckIsolateState(isolate);
     if (::Dart_IsError(state)) {
       return state;
     }
 
-    Function& function = Function::Handle(isolate);
-    function = lib.LookupFunctionAllowPrivate(function_name);
+    const Function& function =
+        Function::Handle(isolate,
+                         lib.LookupFunctionAllowPrivate(function_name));
     if (function.IsNull()) {
       return Api::NewError("%s: did not find top-level function '%s'.",
                            CURRENT_FUNC,
                            function_name.ToCString());
     }
     // LookupFunctionAllowPrivate does not check argument arity, so we
     // do it here.
     String& error_message = String::Handle();
     if (!function.AreValidArgumentCounts(number_of_arguments,
                                          0,
@@ skipping 74 matching lines @@
   if (::Dart_IsError(state)) {
     return state;
   }
 
   Field& field = Field::Handle(isolate);
   Function& getter = Function::Handle(isolate);
   const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(container));
   if (obj.IsNull()) {
     return Api::NewError("%s expects argument 'container' to be non-null.",
                          CURRENT_FUNC);
-  } else if (obj.IsType() || obj.IsClass()) {
+  } else if (obj.IsType()) {
     // To access a static field we may need to use the Field or the
     // getter Function.
-    // For backwards compatibility we allow class objects to be passed in
-    // for now. This needs to be removed once all code that uses class
-    // objects to invoke Dart_GetField is removed.
-    Class& cls = Class::Handle();
-    if (obj.IsType()) {
-      cls = Type::Cast(obj).type_class();
-    } else {
-      cls = Class::Cast(obj).raw();
-    }
+    Class& cls = Class::Handle(isolate, Type::Cast(obj).type_class());
+
     field = cls.LookupStaticField(field_name);
     if (field.IsNull() || FieldIsUninitialized(isolate, field)) {
       const String& getter_name =
           String::Handle(isolate, Field::GetterName(field_name));
       getter = cls.LookupStaticFunctionAllowPrivate(getter_name);
     }
 
     if (!getter.IsNull()) {
       // Invoke the getter and return the result.
       return Api::NewHandle(
@@ skipping 100 matching lines @@
   Dart_Handle state = Api::CheckIsolateState(isolate);
   if (::Dart_IsError(state)) {
     return state;
   }
   Field& field = Field::Handle(isolate);
   Function& setter = Function::Handle(isolate);
   const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(container));
   if (obj.IsNull()) {
     return Api::NewError("%s expects argument 'container' to be non-null.",
                          CURRENT_FUNC);
-  } else if (obj.IsType() || obj.IsClass()) {
+  } else if (obj.IsType()) {
     // To access a static field we may need to use the Field or the
     // setter Function.
-    // For backwards compatibility we allow class objects to be passed in
-    // for now. This needs to be removed once all code that uses class
-    // objects to invoke Dart_SetField is removed.
-    Class& cls = Class::Handle();
-    if (obj.IsType()) {
-      cls = Type::Cast(obj).type_class();
-    } else {
-      cls = Class::Cast(obj).raw();
-    }
+    Class& cls = Class::Handle(isolate, Type::Cast(obj).type_class());
+
     field = cls.LookupStaticField(field_name);
     if (field.IsNull()) {
       String& setter_name =
           String::Handle(isolate, Field::SetterName(field_name));
       setter = cls.LookupStaticFunctionAllowPrivate(setter_name);
     }
 
     if (!setter.IsNull()) {
       // Invoke the setter and return the result.
       const int kNumArgs = 1;
@@ skipping 198 matching lines @@
   }
   CHECK_CALLBACK_STATE(isolate);
 
   String& cls_symbol = String::Handle(isolate, Symbols::New(cls_name));
   const Class& cls = Class::Handle(
       isolate, Class::NewNativeWrapper(lib, cls_symbol, field_count));
   if (cls.IsNull()) {
     return Api::NewError(
         "Unable to create native wrapper class : already exists");
   }
-  return Api::NewHandle(isolate, cls.raw());
+  return Api::NewHandle(isolate, cls.RareType());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetNativeInstanceFieldCount(Dart_Handle obj,
                                                          int* count) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   const Instance& instance = Api::UnwrapInstanceHandle(isolate, obj);
   if (instance.IsNull()) {
     RETURN_TYPE_ERROR(isolate, obj, Instance);
@@ skipping 463 matching lines @@
     RETURN_TYPE_ERROR(isolate, class_name, String);
   }
   const Class& cls = Class::Handle(
       isolate, lib.LookupClassAllowPrivate(cls_name));
   if (cls.IsNull()) {
     // TODO(turnidge): Return null or error in this case?
     const String& lib_name = String::Handle(isolate, lib.name());
     return Api::NewError("Class '%s' not found in library '%s'.",
                          cls_name.ToCString(), lib_name.ToCString());
   }
-  return Api::NewHandle(isolate, cls.raw());
+  return Api::NewHandle(isolate, cls.RareType());
 }
 
 
 DART_EXPORT Dart_Handle Dart_GetType(Dart_Handle library,
                                      Dart_Handle class_name,
                                      intptr_t number_of_type_arguments,
                                      Dart_Handle* type_arguments) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
 
@@ skipping 289 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success();
 }
 
 }  // namespace dart