Fix wrong detection of duplicate definition of function types (issue 187).

runtime/vm/object.h

 // Copyright (c) 2011, 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_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "vm/assert.h"
 #include "vm/dart.h"
 #include "vm/globals.h"
@@ skipping 463 matching lines @@
   bool IsVoidClass() const { return raw() == Object::void_class(); }
 
   // Check if this class represents the 'Object' class.
   bool IsObjectClass() const;
 
   // Check if this class represents a signature class.
   bool IsSignatureClass() const {
     return signature_function() != Object::null();
   }
 
+  // Check if this class represents a canonical signature class, i.e. not an
+  // alias as defined in a typedef.
+  bool IsCanonicalSignatureClass() const;
+
   // Check the "more specific than" relationship.
   bool IsMoreSpecificThan(const TypeArguments& type_arguments,
                           const Class& other,
                           const TypeArguments& other_type_arguments) const;
 
   // Check the subtype relationship.
   bool IsSubtypeOf(const TypeArguments& type_arguments,
                    const Class& other,
                    const TypeArguments& other_type_arguments) const {
     return TestType(kIsSubtypeOf,
@@ skipping 88 matching lines @@
                                     int num_fields);
 
   // Allocate a class representing a function signature described by
   // signature_function, which must be a closure function or a signature
   // function.
   // The class may be type parameterized unless the signature_function is in a
   // static scope. In that case, the type parameters are copied from the owner
   // class of signature_function.
   static RawClass* NewSignatureClass(const String& name,
                                      const Function& signature_function,
-                                     const Script& script,
-                                     intptr_t token_index);
+                                     const Script& script);
 
   // Return a class object corresponding to the specified kind. If
   // a canonicalized version of it exists then that object is returned
   // otherwise a new object is allocated and returned.
   static RawClass* GetClass(ObjectKind kind);
 
  private:
   void set_name(const String& value) const;
   void set_script(const Script& value) const;
   void set_signature_function(const Function& value) const;
@@ skipping 2353 matching lines @@
 }
 
 
 void Context::SetAt(intptr_t index, const Instance& value) const {
   StorePointer(InstanceAddr(index), value.raw());
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_