Introduce class TypeRef in the VM to fully support recursive types.

runtime/vm/class_finalizer.h

 // 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.
 
 #ifndef VM_CLASS_FINALIZER_H_
 #define VM_CLASS_FINALIZER_H_
 
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
 
@@ skipping 15 matching lines @@
 
 // Traverses all pending, unfinalized classes, validates and marks them as
 // finalized.
 class ClassFinalizer : public AllStatic {
  public:
   // Modes for type resolution and finalization. The ordering is relevant.
   enum FinalizationKind {
     kIgnore,                   // Type is ignored and replaced by dynamic.
     kDoNotResolve,             // Type resolution is postponed.
     kResolveTypeParameters,    // Resolve type parameters only.
-    kFinalize,                 // Type resolution and type finalization are
-                               // required; replace a malformed type by dynamic.
+    kFinalize,                 // Type resolution and finalization are required.
     kCanonicalize,             // Same as kFinalize, but with canonicalization.
     kCanonicalizeWellFormed    // Error-free resolution, finalization, and
-                               // canonicalization are required; a malformed
-                               // type is marked as such.
+                               // canonicalization are required.
   };
 
   // Finalize given type while parsing class cls.
   // Also canonicalize type if applicable.
-  static RawAbstractType* FinalizeType(const Class& cls,
-                                       const AbstractType& type,
-                                       FinalizationKind finalization);
+  static RawAbstractType* FinalizeType(
+      const Class& cls,
+      const AbstractType& type,
+      FinalizationKind finalization,
+      GrowableObjectArray* pending_types = NULL);
 
   // Allocate, finalize, and return a new malformed type as if it was declared
   // in class cls at the given token position.
   // If not null, prepend prev_error to the error message built from the format
   // string and its arguments.
   static RawType* NewFinalizedMalformedType(const Error& prev_error,
                                             const Script& script,
                                             intptr_t type_pos,
                                             const char* format, ...)
        PRINTF_ATTRIBUTE(4, 5);
@@ skipping 36 matching lines @@
 
   // Verify that the classes have been properly prefinalized. This is
   // needed during bootstrapping where the classes have been preloaded.
   static void VerifyBootstrapClasses();
 
   // Resolve the type and target of the redirecting factory.
   static void ResolveRedirectingFactory(const Class& cls,
                                         const Function& factory);
 
   // Apply the mixin type to the mixin application class.
-  static void ApplyMixinType(const Class& mixin_app_class);
+  static void ApplyMixinType(const Class& mixin_app_class,
+                             GrowableObjectArray* pending_types = NULL);
 
  private:
   static bool IsSuperCycleFree(const Class& cls);
   static bool IsTypeCycleFree(const Class& cls,
                               const AbstractType& type,
                               GrowableArray<intptr_t>* visited);
   static bool IsAliasCycleFree(const Class& cls,
                                GrowableArray<intptr_t>* visited);
   static bool IsMixinCycleFree(const Class& cls,
                                GrowableArray<intptr_t>* visited);
@@ skipping 10 matching lines @@
   static void CreateForwardingConstructors(
       const Class& mixin_app,
       const GrowableObjectArray& cloned_funcs);
   static void CollectTypeArguments(const Class& cls,
                                    const Type& type,
                                    const GrowableObjectArray& collected_args);
   static RawType* ResolveMixinAppType(const Class& cls,
                                       const MixinAppType& mixin_app_type);
   static void ResolveSuperTypeAndInterfaces(const Class& cls,
                                             GrowableArray<intptr_t>* visited);
-  static void FinalizeTypeParameters(const Class& cls);
+  static void FinalizeTypeParameters(const Class& cls,
+                                     GrowableObjectArray* pending_types = NULL);
   static void FinalizeTypeArguments(const Class& cls,
                                     const AbstractTypeArguments& arguments,
                                     intptr_t num_uninitialized_arguments,
-                                    FinalizationKind finalization,
-                                    Error* bound_error);
+                                    Error* bound_error,
+                                    GrowableObjectArray* pending_types);
+  static void CheckTypeBounds(const Class& cls, const Type& type);
   static void CheckTypeArgumentBounds(const Class& cls,
                                       const AbstractTypeArguments& arguments,
                                       Error* bound_error);
   static void ResolveType(const Class& cls,
                           const AbstractType& type,
                           FinalizationKind finalization);
   static void ResolveUpperBounds(const Class& cls);
   static void FinalizeUpperBounds(const Class& cls);
   static void ResolveAndFinalizeSignature(const Class& cls,
                                           const Function& function);
@@ skipping 13 matching lines @@
                           const char* format, ...) PRINTF_ATTRIBUTE(4, 5);
 
   // Verify implicit offsets recorded in the VM for direct access to fields of
   // Dart instances (e.g: _TypedListView, _ByteDataView).
   static void VerifyImplicitFieldOffsets();
 };
 
 }  // namespace dart
 
 #endif  // VM_CLASS_FINALIZER_H_