Oilpan: Forbid adoptRef(X*) where X is RefCountedGarbageCollected

Source/wtf/PassRefPtr.h

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 165 matching lines @@
     template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const RawPtr<U>& b)
     {
         return a.get() != b.get();
     }
 
     template<typename T, typename U> inline bool operator!=(const RawPtr<T>& a, const PassRefPtr<U>& b)
     {
         return a.get() != b.get();
     }
 
+    template<typename T> class RefCountedGarbageCollected;

[haraken, 2014/10/12 15:16:45]

I'm not sure if this forward declaration is allowed (RefCountedGarbageCollected
is defined in platform/).

[sof, 2014/10/13 12:11:30]

It doesn't quite set a precedent, TypeTraits.h already brings a blink name into
scope like this.

A compile-time name "use" entirely, so it seems reasonable to allow&enable
checks such as this.

[sof, 2014/10/13 12:11:30]

Don't think there is a "using" for it (or in scope), so move the forward decl up
a bit and wrap it in "namespace blink { ... }" (and refer to it as
blink::RefCountedGarbageCollected<> below)? 

     template<typename T> PassRefPtr<T> adoptRef(T* p)
     {
+        static const bool notRefCountedGarbageCollected = !WTF::IsSubclassOfTemplate<typename WTF::RemoveConst<T>::Type, RefCountedGarbageCollected>::value;
+        COMPILE_ASSERT(notRefCountedGarbageCollected, adoptRefIsNotAllowedForRefCountedGarbageCollected);
         adopted(p);
         return PassRefPtr<T>(p, PassRefPtr<T>::AdoptRef);
     }
 
     template<typename T, typename U> inline PassRefPtr<T> static_pointer_cast(const PassRefPtr<U>& p)
     {
         return adoptRef(static_cast<T*>(p.leakRef()));
     }
 
     template<typename T> inline T* getPtr(const PassRefPtr<T>& p)
     {
         return p.get();
     }
 
 } // namespace WTF
 
 using WTF::PassRefPtr;
 using WTF::adoptRef;
 using WTF::static_pointer_cast;
 
 #endif // WTF_PassRefPtr_h