Fix typedef cycle check (fixes #25620).

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 15691 matching lines @@
   // If the type is still being finalized, we may be reporting an error about
   // a malformed type, so proceed with caution.
   const TypeArguments& args = TypeArguments::Handle(zone, arguments());
   const intptr_t num_args = args.IsNull() ? 0 : args.Length();
   String& class_name = String::Handle(zone);
   intptr_t first_type_param_index;
   intptr_t num_type_params;  // Number of type parameters to print.
   Class& cls = Class::Handle(zone);
   if (IsFunctionType()) {
     cls = type_class();
-    if (!cls.IsTypedefClass()) {
-      const Function& signature_function = Function::Handle(
-          zone, FunctionType::Cast(*this).signature());
+    const Function& signature_function = Function::Handle(
+        zone, FunctionType::Cast(*this).signature());
+    if (!cls.IsTypedefClass() ||
+        (cls.signature_function() != signature_function.raw())) {
       if (!IsFinalized() || IsBeingFinalized() || IsMalformed()) {
         return signature_function.UserVisibleSignature();
       }
       return signature_function.InstantiatedSignatureFrom(args,
                                                           name_visibility);
     }
     class_name = cls.Name();  // Typedef name.
     // We may be reporting an error about a malformed function type. In that
     // case, avoid instantiating the signature, since it may cause divergence.
     if (!IsFinalized() || IsBeingFinalized() || IsMalformed()) {
@@ skipping 1409 matching lines @@
          (state <= RawFunctionType::kFinalizedUninstantiated));
   StoreNonPointer(&raw_ptr()->type_state_, state);
 }
 
 
 const char* FunctionType::ToCString() const {
   const char* unresolved = IsResolved() ? "" : "Unresolved ";
   const Class& scope_cls = Class::Handle(scope_class());
   const TypeArguments& type_arguments = TypeArguments::Handle(arguments());
   const Function& signature_function = Function::Handle(signature());
-  const String& signature_string = String::Handle(
-      signature_function.InstantiatedSignatureFrom(type_arguments,
-                                                   kInternalName));
+  const String& signature_string = IsFinalized() ?
+      String::Handle(
+          signature_function.InstantiatedSignatureFrom(type_arguments,
+                                                       kInternalName)) :
+      String::Handle(signature_function.Signature());
   if (scope_cls.IsClosureClass()) {
     ASSERT(arguments() == TypeArguments::null());
     return OS::SCreate(
         Thread::Current()->zone(),
         "%sFunctionType: %s", unresolved, signature_string.ToCString());
   }
   const char* class_name = String::Handle(scope_cls.Name()).ToCString();
   const char* args_cstr =
       type_arguments.IsNull() ? "null" : type_arguments.ToCString();
   return OS::SCreate(
@@ skipping 5682 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart