DEFINE_STATIC_LOCAL(): assert against illegal use of GCed types.

third_party/WebKit/Source/platform/heap/Handle.h

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
 #include "wtf/RawPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/TypeTraits.h"
 
 #if defined(LEAK_SANITIZER)
 #include "wtf/LeakAnnotations.h"
 #endif
 
 namespace blink {
 
+// Marker used to annotate persistent objects and collections with,
+// so as to enable reliable testing for persistent references via
+// a type trait (see TypeTraits.h's IsPersistentReferenceType<>.)
+#define IS_PERSISTENT_REFERENCE_TYPE()               \
+    public:                                          \
+        using IsPersistentReferenceTypeMarker = int; \
+    private:
+
 enum WeaknessPersistentConfiguration {
     NonWeakPersistentConfiguration,
     WeakPersistentConfiguration
 };
 
 enum CrossThreadnessPersistentConfiguration {
     SingleThreadPersistentConfiguration,
     CrossThreadPersistentConfiguration
 };
 
 template<typename T, WeaknessPersistentConfiguration weaknessConfiguration, CrossThreadnessPersistentConfiguration crossThreadnessConfiguration>
 class PersistentBase {
+    IS_PERSISTENT_REFERENCE_TYPE();
 public:
     PersistentBase() : m_raw(nullptr)
     {
         initialize();
     }
 
     PersistentBase(std::nullptr_t) : m_raw(nullptr)
     {
         initialize();
     }
@@ skipping 447 matching lines @@
         return *this;
     }
 };
 
 template<typename Collection>
 class PersistentHeapCollectionBase : public Collection {
     // We overload the various new and delete operators with using the WTF PartitionAllocator to ensure persistent
     // heap collections are always allocated off-heap. This allows persistent collections to be used in
     // DEFINE_STATIC_LOCAL et. al.
     WTF_USE_ALLOCATOR(PersistentHeapCollectionBase, WTF::PartitionAllocator);
+    IS_PERSISTENT_REFERENCE_TYPE();
 public:
     PersistentHeapCollectionBase()
     {
         initialize();
     }
 
     PersistentHeapCollectionBase(const PersistentHeapCollectionBase& other) : Collection(other)
     {
         initialize();
     }
@@ skipping 1025 matching lines @@
     // TODO(sof): extend WTF::FunctionWrapper call overloading to also handle (CrossThread)WeakPersistent.
     static T* unwrap(const StorageType& value) { return value.get(); }
 };
 
 template<typename T>
 PassRefPtr<T> adoptRef(blink::RefCountedGarbageCollected<T>*) = delete;
 
 } // namespace WTF
 
 #endif