GC plugin: improve error reporting when tracing illegal fields.

tools/clang/blink_gc_plugin/tests/heap/stubs.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEAP_STUBS_H_
 #define HEAP_STUBS_H_
 
 #include "stddef.h"
 
 #define WTF_MAKE_FAST_ALLOCATED                 \
@@ skipping 100 matching lines @@
     typename KeyArg,
     typename MappedArg,
     typename HashArg = void,
     typename KeyTraitsArg = void,
     typename MappedTraitsArg = void,
     typename Allocator = DefaultAllocator>
 class HashMap {};
 
 }
 
+// Empty namespace declaration to exercise internal
+// handling of namespace equality.
+namespace std {
+  /* empty */
+}
+
+namespace std {
+
+template<typename T> class unique_ptr {
+public:
+    ~unique_ptr() { }
+    operator T*() const { return 0; }
+    T* operator->() { return 0; }
+};
+
+}
+
 namespace blink {
 
 using namespace WTF;
 
 #define DISALLOW_ALLOCATION()                   \
     private:                                    \
     void* operator new(size_t) = delete;        \
     void* operator new(size_t, void*) = delete;
 
 #define STACK_ALLOCATED()                                   \
@@ skipping 40 matching lines @@
     bool operator!() const { return false; }
 };
 
 template<typename T> class Persistent {
 public:
     operator T*() const { return 0; }
     T* operator->() { return 0; }
     bool operator!() const { return false; }
 };
 
+template<typename T> class WeakPersistent {
+public:
+    operator T*() const { return 0; }
+    T* operator->() { return 0; }
+    bool operator!() const { return false; }
+};
+
+template<typename T> class CrossThreadPersistent {
+public:
+    operator T*() const { return 0; }
+    T* operator->() { return 0; }
+    bool operator!() const { return false; }
+};
+
+template<typename T> class CrossThreadWeakPersistent {
+public:
+    operator T*() const { return 0; }
+    T* operator->() { return 0; }
+    bool operator!() const { return false; }
+};
+
 class HeapAllocator {
 public:
     static const bool isGarbageCollected = true;
 };
 
 template<typename T, size_t inlineCapacity = 0>
 class HeapVector : public Vector<T, inlineCapacity, HeapAllocator> { };
 
 template<typename T, size_t inlineCapacity = 0>
 class HeapDeque : public Vector<T, inlineCapacity, HeapAllocator> { };
@@ skipping 57 matching lines @@
 namespace WTF {
 
 template<typename T>
 struct VectorTraits<blink::Member<T> > {
     static const bool needsDestruction = false;
 };
 
 }
 
 #endif