Source/JavaScriptCore/runtime/JSGlobalObjectInlines.h

/*
 * Copyright (C) 2016 Apple 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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. 
 */

#pragma once

#include "JSGlobalObject.h"

#include "ArrayConstructor.h"
#include "ArrayPrototype.h"
#include "JSCustomGetterFunction.h"
#include "JSCustomSetterFunction.h"
#include "JSFunction.h"
#include "LinkTimeConstant.h"
#include "ObjectPrototype.h"

namespace JSC {

ALWAYS_INLINE bool JSGlobalObject::objectPrototypeIsSaneConcurrently(Structure* objectPrototypeStructure)
{
    return !hasIndexedProperties(objectPrototypeStructure->indexingType())
        && objectPrototypeStructure->hasMonoProto()
        && objectPrototypeStructure->storedPrototype().isNull();
}

ALWAYS_INLINE bool JSGlobalObject::arrayPrototypeChainIsSaneConcurrently(Structure* arrayPrototypeStructure, Structure* objectPrototypeStructure)
{
    return !hasIndexedProperties(arrayPrototypeStructure->indexingType())
        && arrayPrototypeStructure->hasMonoProto()
        && arrayPrototypeStructure->storedPrototype() == objectPrototype()
        && objectPrototypeIsSaneConcurrently(objectPrototypeStructure);
}

ALWAYS_INLINE bool JSGlobalObject::stringPrototypeChainIsSaneConcurrently(Structure* stringPrototypeStructure, Structure* objectPrototypeStructure)
{
    return !hasIndexedProperties(stringPrototypeStructure->indexingType())
        && stringPrototypeStructure->hasMonoProto()
        && stringPrototypeStructure->storedPrototype() == objectPrototype()
        && objectPrototypeIsSaneConcurrently(objectPrototypeStructure);
}

ALWAYS_INLINE bool JSGlobalObject::arrayPrototypeChainIsSane()
{
    VM& vm = this->vm();
    ASSERT(!isCompilationThread() && !Thread::mayBeGCThread());
    Structure* arrayPrototypeStructure = arrayPrototype()->structure(vm);
    Structure* objectPrototypeStructure = objectPrototype()->structure(vm);
    return arrayPrototypeChainIsSaneConcurrently(arrayPrototypeStructure, objectPrototypeStructure);
}

ALWAYS_INLINE bool JSGlobalObject::stringPrototypeChainIsSane()
{
    VM& vm = this->vm();
    ASSERT(!isCompilationThread() && !Thread::mayBeGCThread());
    Structure* stringPrototypeStructure = stringPrototype()->structure(vm);
    Structure* objectPrototypeStructure = objectPrototype()->structure(vm);
    return stringPrototypeChainIsSaneConcurrently(stringPrototypeStructure, objectPrototypeStructure);
}

ALWAYS_INLINE bool JSGlobalObject::isArrayPrototypeIteratorProtocolFastAndNonObservable()
{
    // We're fast if we don't have any indexed properties on the prototype.
    // We're non-observable if the iteration protocol hasn't changed.
    //
    // Note: it only makes sense to call this from the main thread. If you're
    // trying to prove this behavior on the compiler thread, you'll want to
    // carefully set up watchpoints to have correct ordering while JS code is
    // executing concurrently.

    return arrayIteratorProtocolWatchpointSet().isStillValid() && !isHavingABadTime() && arrayPrototypeChainIsSane();
}

// We're non-observable if the iteration protocol hasn't changed.
//
// Note: it only makes sense to call this from the main thread. If you're
// trying to prove this behavior on the compiler thread, you'll want to
// carefully set up watchpoints to have correct ordering while JS code is
// executing concurrently.
ALWAYS_INLINE bool JSGlobalObject::isMapPrototypeIteratorProtocolFastAndNonObservable()
{
    return mapIteratorProtocolWatchpointSet().isStillValid();
}

ALWAYS_INLINE bool JSGlobalObject::isSetPrototypeIteratorProtocolFastAndNonObservable()
{
    return setIteratorProtocolWatchpointSet().isStillValid();
}

ALWAYS_INLINE bool JSGlobalObject::isStringPrototypeIteratorProtocolFastAndNonObservable()
{
    return stringIteratorProtocolWatchpointSet().isStillValid();
}

ALWAYS_INLINE bool JSGlobalObject::isMapPrototypeSetFastAndNonObservable()
{
    return mapSetWatchpointSet().isStillValid();
}

ALWAYS_INLINE bool JSGlobalObject::isSetPrototypeAddFastAndNonObservable()
{
    return setAddWatchpointSet().isStillValid();
}

ALWAYS_INLINE Structure* JSGlobalObject::arrayStructureForIndexingTypeDuringAllocation(JSGlobalObject* globalObject, IndexingType indexingType, JSValue newTarget) const
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);
    if (!newTarget || newTarget == globalObject->arrayConstructor())
        return globalObject->arrayStructureForIndexingTypeDuringAllocation(indexingType);
    auto* functionGlobalObject = getFunctionRealm(globalObject, asObject(newTarget));
    RETURN_IF_EXCEPTION(scope, nullptr);
    RELEASE_AND_RETURN(scope, InternalFunction::createSubclassStructure(globalObject, asObject(newTarget), functionGlobalObject->arrayStructureForIndexingTypeDuringAllocation(indexingType)));
}

inline JSFunction* JSGlobalObject::throwTypeErrorFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::throwTypeErrorFunction)); }
inline JSFunction* JSGlobalObject::newPromiseCapabilityFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::newPromiseCapability)); }
inline JSFunction* JSGlobalObject::resolvePromiseFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::resolvePromise)); }
inline JSFunction* JSGlobalObject::rejectPromiseFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::rejectPromise)); }
inline JSFunction* JSGlobalObject::promiseProtoThenFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::defaultPromiseThen)); }
inline JSFunction* JSGlobalObject::performPromiseThenFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::performPromiseThen)); }
inline JSFunction* JSGlobalObject::regExpProtoExecFunction() const { return jsCast<JSFunction*>(linkTimeConstant(LinkTimeConstant::regExpBuiltinExec)); }
inline GetterSetter* JSGlobalObject::regExpProtoGlobalGetter() const { return bitwise_cast<GetterSetter*>(linkTimeConstant(LinkTimeConstant::regExpProtoGlobalGetter)); }
inline GetterSetter* JSGlobalObject::regExpProtoUnicodeGetter() const { return bitwise_cast<GetterSetter*>(linkTimeConstant(LinkTimeConstant::regExpProtoUnicodeGetter)); }

ALWAYS_INLINE VM& getVM(JSGlobalObject* globalObject)
{
    return globalObject->vm();
}

template<typename T>
inline unsigned JSGlobalObject::WeakCustomGetterOrSetterHash<T>::hash(const Weak<T>& value)
{
    if (!value)
        return 0;
    return hash(value->propertyName(), value->customFunctionPointer());
}

template<typename T>
inline bool JSGlobalObject::WeakCustomGetterOrSetterHash<T>::equal(const Weak<T>& a, const Weak<T>& b)
{
    if (!a || !b)
        return false;
    return a == b;
}

template<typename T>
inline unsigned JSGlobalObject::WeakCustomGetterOrSetterHash<T>::hash(const PropertyName& propertyName, typename T::CustomFunctionPointer functionPointer)
{
    unsigned hash = DefaultHash<typename T::CustomFunctionPointer>::hash(functionPointer);
    if (!propertyName.isNull())
        hash = WTF::pairIntHash(hash, propertyName.uid()->existingSymbolAwareHash());
    return hash;
}

} // namespace JSC