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/*
* Copyright (C) 2010 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 "bindings/v8/UnsafePersistent.h"
#include "bindings/v8/V8Utilities.h"
#include "bindings/v8/WrapperTypeInfo.h"
#include <v8.h>
// Helper to call webCoreInitializeScriptWrappableForInterface in the global namespace.
template <class C> inline void initializeScriptWrappableHelper(C* object)
{
void webCoreInitializeScriptWrappableForInterface(C*);
webCoreInitializeScriptWrappableForInterface(object);
}
namespace WebCore {
class ScriptWrappable {
public:
ScriptWrappable() : m_wrapperOrTypeInfo(0) { }
// Wrappables need to be initialized with their most derrived 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.
template <class C> static void init(C* object)
{
initializeScriptWrappableHelper(object);
}
void setWrapper(v8::Handle<v8::Object> wrapper, v8::Isolate* isolate, const WrapperConfiguration& configuration)
{
ASSERT(!containsWrapper());
if (!*wrapper) {
m_wrapperOrTypeInfo = 0;
return;
}
v8::Persistent<v8::Object> persistent(isolate, wrapper);
configuration.configureWrapper(&persistent);
persistent.SetWeak(this, &setWeakCallback);
m_wrapperOrTypeInfo = reinterpret_cast<uintptr_t>(persistent.ClearAndLeak()) | 1;
ASSERT(containsWrapper());
}
v8::Local<v8::Object> newLocalWrapper(v8::Isolate* isolate) const
{
return unsafePersistent().newLocal(isolate);
}
const WrapperTypeInfo* typeInfo()
{
if (containsTypeInfo())
return reinterpret_cast<const WrapperTypeInfo*>(m_wrapperOrTypeInfo);
if (containsWrapper())
return toWrapperTypeInfo(*(unsafePersistent().persistent()));
return 0;
}
void setTypeInfo(const WrapperTypeInfo* info)
{
m_wrapperOrTypeInfo = reinterpret_cast<uintptr_t>(info);
ASSERT(containsTypeInfo());
}
static bool wrapperCanBeStoredInObject(const void*) { return false; }
static bool wrapperCanBeStoredInObject(const ScriptWrappable*) { return true; }
static void setWrapperInObject(void*, v8::Handle<v8::Object>, v8::Isolate*, const WrapperConfiguration&)
{
ASSERT_NOT_REACHED();
}
static void setWrapperInObject(ScriptWrappable* object, v8::Handle<v8::Object> wrapper, v8::Isolate* isolate, const WrapperConfiguration& configuration)
{
object->setWrapper(wrapper, isolate, configuration);
}
static const WrapperTypeInfo* getTypeInfoFromObject(void* object)
{
ASSERT_NOT_REACHED();
return 0;
}
static const WrapperTypeInfo* getTypeInfoFromObject(ScriptWrappable* object)
{
return object->typeInfo();
}
static void setTypeInfoInObject(void* object, const WrapperTypeInfo* info)
{
ASSERT_NOT_REACHED();
}
static void setTypeInfoInObject(ScriptWrappable* object, const WrapperTypeInfo* info)
{
object->setTypeInfo(info);
}
template<typename V8T, typename T>
static bool setReturnValueWithSecurityCheck(v8::ReturnValue<v8::Value> returnValue, T* object)
{
return ScriptWrappable::getUnsafeWrapperFromObject(object).template setReturnValueWithSecurityCheck<V8T>(returnValue, object);
}
template<typename T>
static bool setReturnValue(v8::ReturnValue<v8::Value> returnValue, T* object)
{
return ScriptWrappable::getUnsafeWrapperFromObject(object).setReturnValue(returnValue);
}
protected:
~ScriptWrappable()
{
ASSERT(m_wrapperOrTypeInfo); // Assert initialization via init() even if not subsequently wrapped.
m_wrapperOrTypeInfo = 0; // Break UAF attempts to wrap.
}
private:
// For calling unsafePersistent and getWrapperFromObject.
friend class MinorGCWrapperVisitor;
friend class DOMDataStore;
UnsafePersistent<v8::Object> unsafePersistent() const
{
v8::Object* object = containsWrapper() ? reinterpret_cast<v8::Object*>(m_wrapperOrTypeInfo & ~1) : 0;
return UnsafePersistent<v8::Object>(object);
}
static UnsafePersistent<v8::Object> getUnsafeWrapperFromObject(void*)
{
ASSERT_NOT_REACHED();
return UnsafePersistent<v8::Object>();
}
static UnsafePersistent<v8::Object> getUnsafeWrapperFromObject(ScriptWrappable* object)
{
return object->unsafePersistent();
}
inline bool containsWrapper() const { return (m_wrapperOrTypeInfo & 1) == 1; }
inline bool containsTypeInfo() const { return m_wrapperOrTypeInfo && (m_wrapperOrTypeInfo & 1) == 0; }
inline void disposeWrapper(v8::Local<v8::Object> value, const WrapperTypeInfo* info)
{
ASSERT(containsWrapper());
ASSERT(value == *unsafePersistent().persistent());
unsafePersistent().dispose();
setTypeInfo(info);
}
// If zero, then this contains nothing, otherwise:
// If the bottom bit it set, then this contains a pointer to a wrapper object in the remainging bits.
// If the bottom bit is clear, then this contains a pointer to the wrapper type info in the remaining bits.
uintptr_t m_wrapperOrTypeInfo;
static void setWeakCallback(const v8::WeakCallbackData<v8::Object, ScriptWrappable>& data)
{
ASSERT(*data.GetParameter()->unsafePersistent().persistent() == data.GetValue());
// Note: |object| might not be equal to |data|.GetParameter(), e.g., if ScriptWrappable isn't a left-most base class.
void* object = toNative(data.GetValue());
const WrapperTypeInfo* info = toWrapperTypeInfo(data.GetValue());
ASSERT(info->derefObjectFunction);
data.GetParameter()->disposeWrapper(data.GetValue(), info);
// FIXME: I noticed that 50%~ of minor GC cycle times can be consumed
// inside data.GetParameter()->deref(), which causes Node destructions. We should
// make Node destructions incremental.
info->derefObject(object);
}
};
} // namespace WebCore
#endif // ScriptWrappable_h
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