Ensure a class is finalized before attempting any reflective invocation on it.

runtime/lib/mirrors.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 "lib/invocation_mirror.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
@@ skipping 314 matching lines @@
   if (cls.IsSignatureClass()) {
     if (cls.IsCanonicalSignatureClass()) {
       // We represent function types as canonical signature classes.
       return CreateFunctionTypeMirror(cls, type);
     } else {
       // We represent typedefs as non-canonical signature classes.
       return CreateTypedefMirror(cls, type, is_declaration, owner_mirror);
     }
   }
 
+  const Error& error = Error::Handle(cls.EnsureIsFinalized(Isolate::Current()));
+  if (!error.IsNull()) {
+    ThrowInvokeError(error);

[zra, 2014/01/08 23:02:54]

After many other calls to ThrowInvokeError() there is an UNREACHABLE() assert.
Maybe add one for consistency's sake.

[rmacnak, 2014/01/09 00:17:58]

Done.

+  }
+
   const Bool& is_generic = Bool::Get(cls.NumTypeParameters() != 0);
   const Bool& is_mixin_app_alias = Bool::Get(cls.is_mixin_app_alias());
 
   const Array& args = Array::Handle(Array::New(7));
   args.SetAt(0, MirrorReference::Handle(MirrorReference::New(cls)));
   args.SetAt(1, type);
   // We do not set the names of anonymous mixin applications because the mirrors
   // use a different naming convention than the VM (lib.S with lib.M and S&M
   // respectively).
   if (!cls.IsAnonymousMixinApplication()) {
@@ skipping 1701 matching lines @@
 
 DEFINE_NATIVE_ENTRY(VariableMirror_type, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Field& field = Field::Handle(ref.GetFieldReferent());
   GET_NATIVE_ARGUMENT(AbstractType, instantiator, arguments->NativeArgAt(1));
   const AbstractType& type = AbstractType::Handle(field.type());
   return InstantiateType(type, instantiator);
 }
 
 }  // namespace dart