Import Dart bindings as of Blink r188698. This merely copies the files over and does not attach any…

sky/engine/bindings-dart/common/ScriptWrappable.h

Index: sky/engine/bindings-dart/common/ScriptWrappable.h
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+/*
+ * 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
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef ScriptWrappable_h
+#define ScriptWrappable_h
+
+#include "platform/ScriptForbiddenScope.h"
+#include "platform/heap/Handle.h"
+#include <v8.h>
+#include "wtf/Assertions.h"
+
+// Helper to call webCoreInitializeScriptWrappableForInterface in the global namespace.
+template <class C> inline void initializeScriptWrappableHelper(C* object)
+{
+    void webCoreInitializeScriptWrappableForInterface(C*);
+    webCoreInitializeScriptWrappableForInterface(object);
+}
+
+namespace blink {
+
+// Forward declarations.
+class DartWrapperInfo;
+class DartMultiWrapperInfo;
+struct WrapperTypeInfo;
+
+/**
+ * The base class of all wrappable objects.
+ *
+ * This class provides the internal pointer to be stored in the wrapper objects,
+ * and its conversions from / to the DOM instances.
+ *
+ * Note that this class must not have vtbl (any virtual function) or any member
+ * variable which increase the size of instances.  Some of the classes sensitive
+ * to the size inherit from this class.  So this class must be zero size.
+ */
+class ScriptWrappableBase {
+public:
+    template <class T> static T* fromInternalPointer(ScriptWrappableBase* internalPointer)
+    {
+        // Check if T* is castable to ScriptWrappableBase*, which means T
+        // doesn't have two or more ScriptWrappableBase as superclasses.
+        // If T has two ScriptWrappableBase as superclasses, conversions
+        // from T* to ScriptWrappableBase* are ambiguous.
+        ASSERT(static_cast<ScriptWrappableBase*>(static_cast<T*>(internalPointer)));
+        return static_cast<T*>(internalPointer);
+    }
+    ScriptWrappableBase* toInternalPointer() { return this; }
+};
+
+// An optimization to avoid in the common case the cost of map lookups when
+// finding the V8 or Dart wrapper for a Blink object and to quickly find the
+// most specific V8 or Dart wrapper type for a Blink object.
+class ScriptWrappable : public ScriptWrappableBase {
+public:
+    class TaggedPointer {
+    private:
+        enum {
+            kTypeInfoTag = 0x0,
+            kV8WrapperTag = 0x1,
+            kDartWrapperTag = 0x2,
+            kMultiWrapperTag = 0x3
+        };
+        static const intptr_t kWrappableBitMask = 0x3;
+
+        uintptr_t m_ptr;
+
+    public:
+        TaggedPointer() : m_ptr(0) { }
+
+        explicit TaggedPointer(const WrapperTypeInfo* info) : m_ptr(reinterpret_cast<uintptr_t>(info) | kTypeInfoTag)
+        {
+            // Assert incoming pointer is non-null and 4-byte aligned.
+            ASSERT(info && ((reinterpret_cast<uintptr_t>(info) & kWrappableBitMask) == 0));
+        }
+
+        explicit TaggedPointer(v8::Object* info) : m_ptr(reinterpret_cast<uintptr_t>(info) | kV8WrapperTag)
+        {
+            // Assert incoming pointer is non-null and 4-byte aligned.
+            ASSERT(info && ((reinterpret_cast<uintptr_t>(info) & kWrappableBitMask) == 0));
+        }
+
+        explicit TaggedPointer(DartWrapperInfo* info) : m_ptr(reinterpret_cast<uintptr_t>(info) | kDartWrapperTag)
+        {
+            // Assert incoming pointer is non-null and 4-byte aligned.
+            ASSERT(info && ((reinterpret_cast<uintptr_t>(info) & kWrappableBitMask) == 0));
+        }
+
+        explicit TaggedPointer(DartMultiWrapperInfo* info) : m_ptr(reinterpret_cast<uintptr_t>(info) | kMultiWrapperTag)
+        {
+            // Assert incoming pointer is non-null and 4-byte aligned.
+            ASSERT(info && ((reinterpret_cast<uintptr_t>(info) & kWrappableBitMask) == 0));
+        }
+
+        inline bool isEmpty() const
+        {
+            return !m_ptr;
+        }
+
+        inline bool isWrapperTypeInfo() const
+        {
+            return (m_ptr & kWrappableBitMask) == kTypeInfoTag;
+        }
+
+        inline bool isV8Wrapper() const
+        {
+            return (m_ptr & kWrappableBitMask) == kV8WrapperTag;
+        }
+
+        inline bool isDartWrapperInfo() const
+        {
+            return (m_ptr & kWrappableBitMask) == kDartWrapperTag;
+        }
+
+        inline bool isDartMultiWrapperInfo() const
+        {
+            return (m_ptr & kWrappableBitMask) == kMultiWrapperTag;
+        }
+
+        inline const WrapperTypeInfo* wrapperTypeInfo() const
+        {
+            return reinterpret_cast<const WrapperTypeInfo*>(m_ptr & ~kWrappableBitMask);
+        }
+
+        inline v8::Object* v8Wrapper() const
+        {
+            return reinterpret_cast<v8::Object*>(m_ptr & ~kWrappableBitMask);
+        }
+
+        inline DartWrapperInfo* dartWrapperInfo() const
+        {
+            return reinterpret_cast<DartWrapperInfo*>(m_ptr & ~kWrappableBitMask);
+        }
+
+        inline DartMultiWrapperInfo* dartMultiWrapperInfo() const
+        {
+            return reinterpret_cast<DartMultiWrapperInfo*>(m_ptr & ~kWrappableBitMask);
+        }
+
+        inline void clear()
+        {
+            m_ptr = 0;
+        }
+    };
+
+    COMPILE_ASSERT(sizeof(TaggedPointer) == sizeof(void*), taggedPointerIsNotOneWord);
+
+public:
+    ScriptWrappable() : m_v8WrapperOrTypeInfo(), m_dartWrapperInfo() { }
+
+    // Wrappables need to be initialized with their most derived type for which
+    // bindings exist, in much the same way that certain other types need to be
+    // adopted and so forth. The overloaded initializeScriptWrappableForInterface()
+    // functions are implemented by the generated V8 bindings code. Declaring the
+    // extern function in the template avoids making a centralized header of all
+    // the bindings in the universe. C++11's extern template feature may provide
+    // a cleaner solution someday.
+    // FIXME: Also initialize Dart type info.
+    template <class C> static void init(C* object)
+    {
+        initializeScriptWrappableHelper(object);
+    }
+
+    inline const WrapperTypeInfo* getTypeInfo() const;
+    inline void setTypeInfo(const WrapperTypeInfo* info);
+
+    inline bool containsV8Wrapper() const;
+    inline void setV8Wrapper(v8::Object* wrapper);
+    inline v8::Object* getV8Wrapper() const;
+    inline void clearV8Wrapper(v8::Local<v8::Object> wrapper, v8::Persistent<v8::Object>* persistent);
+
+    inline void setDartWrapper(void* domData, void* wrapper);
+    inline void* getDartWrapper(void * domData) const;
+    inline void clearDartWrapper(void* domData);
+
+    static bool wrapperCanBeStoredInObject(const void*) { return false; }
+    static bool wrapperCanBeStoredInObject(const ScriptWrappable*) { return true; }
+
+    static ScriptWrappable* fromObject(const void*)
+    {
+        ASSERT_NOT_REACHED();
+        return 0;
+    }
+
+    static ScriptWrappable* fromObject(ScriptWrappable* object)
+    {
+        return object;
+    }
+
+#if !ENABLE(OILPAN)
+protected:
+    virtual ~ScriptWrappable()
+    {
+        // We must not get deleted as long as we contain a wrapper. If this happens, we screwed up ref
+        // counting somewhere. Crash here instead of crashing during a later gc cycle.
+        RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(m_v8WrapperOrTypeInfo.isWrapperTypeInfo());
+        RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(m_dartWrapperInfo.isEmpty());
+        // Assert initialization via init() even if not subsequently wrapped.
+        ASSERT(!m_v8WrapperOrTypeInfo.isEmpty());
+        // Break UAF attempts to wrap.
+        m_v8WrapperOrTypeInfo.clear();
+    }
+#endif
+    // With Oilpan we don't need a ScriptWrappable destructor.
+    //
+    // - 'RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!containsWrapper())' is not needed
+    // because Oilpan is not using reference counting at all. If containsWrapper() is true,
+    // it means that ScriptWrappable still has a wrapper. In this case, the destructor
+    // must not be called since the wrapper has a persistent handle back to this ScriptWrappable object.
+    // Assuming that Oilpan's GC is correct (If we cannot assume this, a lot of more things are
+    // already broken), we must not hit the RELEASE_ASSERT.
+    //
+    // - 'm_wrapperOrTypeInfo = 0' is not needed because Oilpan's GC zeroes out memory when
+    // the memory is collected and added to a free list.
+
+private:
+    // A tagged pointer to this object's V8 or Dart peer. It may contain:
+    // -- nothing, transiently during construction/destruction
+    // -- WrapperTypeInfo, if this object has no peers
+    // -- v8::Object, if this object has a V8 peer in the main world and no Dart
+    //    peer
+    // -- DartWrapperInfo, if this object has one Dart peer and possibly a V8
+    //    peer in the main world
+    // -- DartMultiWrapperInfo, if this object has more than one Dart peer and
+    //    possibly a V8 peer in the main world
+    TaggedPointer m_v8WrapperOrTypeInfo;
+    TaggedPointer m_dartWrapperInfo;
+};
+
+} // namespace blink
+
+#include "bindings/core/dart/DartScriptWrappable.h"
+#include "bindings/core/v8/V8ScriptWrappable.h"
+
+#endif // ScriptWrappable_h