Skip over unfinalized interface types during a compile-time subtype check in

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 2493 matching lines @@
   }
   // Check for 'direct super type' specified in the implements clause
   // and check for transitivity at the same time.
   Array& interfaces = Array::Handle(this->interfaces());
   AbstractType& interface = AbstractType::Handle();
   Class& interface_class = Class::Handle();
   AbstractTypeArguments& interface_args = AbstractTypeArguments::Handle();
   Error& args_malformed_error = Error::Handle();
   for (intptr_t i = 0; i < interfaces.Length(); i++) {
     interface ^= interfaces.At(i);
+    if (!interface.IsFinalized()) {
+      // We may be checking bounds at finalization time. Skipping this
+      // unfinalized interface will postpone bound checking to run time.
+      continue;
+    }
     interface_class = interface.type_class();
     interface_args = interface.arguments();
     if (!interface_args.IsNull() && !interface_args.IsInstantiated()) {
       // This type class implements an interface that is parameterized with
       // generic type(s), e.g. it implements List<T>.
       // The uninstantiated type T must be instantiated using the type
       // parameters of this type before performing the type test.
       // The type arguments of this type that are referred to by the type
       // parameters of the interface are at the end of the type vector,
       // after the type arguments of the super type of this type.
       // The index of the type parameters is adjusted upon finalization.
-      ASSERT(interface.IsFinalized());
       args_malformed_error = Error::null();
       interface_args = interface_args.InstantiateFrom(type_arguments,
                                                       &args_malformed_error);
       if (!args_malformed_error.IsNull()) {
         // Return the first malformed error to the caller if it requests it.
         if ((malformed_error != NULL) && malformed_error->IsNull()) {
           *malformed_error = args_malformed_error.raw();
         }
         continue;  // Another interface may work better.
       }
@@ skipping 12121 matching lines @@
 }
 
 
 void MirrorReference::PrintToJSONStream(JSONStream* stream, bool ref) const {
   stream->OpenObject();
   stream->CloseObject();
 }
 
 
 }  // namespace dart