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/*
* Copyright (C) 2014, 2015 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.
*/
#include "config.h"
#include "PutByIdVariant.h"
#include "CallLinkStatus.h"
#include "JSCInlines.h"
#include <wtf/ListDump.h>
namespace JSC {
PutByIdVariant::PutByIdVariant(const PutByIdVariant& other)
: PutByIdVariant()
{
*this = other;
}
PutByIdVariant& PutByIdVariant::operator=(const PutByIdVariant& other)
{
m_kind = other.m_kind;
m_oldStructure = other.m_oldStructure;
m_newStructure = other.m_newStructure;
m_conditionSet = other.m_conditionSet;
m_offset = other.m_offset;
m_requiredType = other.m_requiredType;
if (other.m_callLinkStatus)
m_callLinkStatus = std::make_unique<CallLinkStatus>(*other.m_callLinkStatus);
else
m_callLinkStatus = nullptr;
return *this;
}
PutByIdVariant PutByIdVariant::replace(
const StructureSet& structure, PropertyOffset offset, const InferredType::Descriptor& requiredType)
{
PutByIdVariant result;
result.m_kind = Replace;
result.m_oldStructure = structure;
result.m_offset = offset;
result.m_requiredType = requiredType;
return result;
}
PutByIdVariant PutByIdVariant::transition(
const StructureSet& oldStructure, Structure* newStructure,
const ObjectPropertyConditionSet& conditionSet, PropertyOffset offset,
const InferredType::Descriptor& requiredType)
{
PutByIdVariant result;
result.m_kind = Transition;
result.m_oldStructure = oldStructure;
result.m_newStructure = newStructure;
result.m_conditionSet = conditionSet;
result.m_offset = offset;
result.m_requiredType = requiredType;
return result;
}
PutByIdVariant PutByIdVariant::setter(
const StructureSet& structure, PropertyOffset offset,
const ObjectPropertyConditionSet& conditionSet,
std::unique_ptr<CallLinkStatus> callLinkStatus)
{
PutByIdVariant result;
result.m_kind = Setter;
result.m_oldStructure = structure;
result.m_conditionSet = conditionSet;
result.m_offset = offset;
result.m_callLinkStatus = WTFMove(callLinkStatus);
result.m_requiredType = InferredType::Top;
return result;
}
Structure* PutByIdVariant::oldStructureForTransition() const
{
ASSERT(kind() == Transition);
ASSERT(m_oldStructure.size() <= 2);
for (unsigned i = m_oldStructure.size(); i--;) {
Structure* structure = m_oldStructure[i];
if (structure != m_newStructure)
return structure;
}
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
bool PutByIdVariant::writesStructures() const
{
switch (kind()) {
case Transition:
case Setter:
return true;
default:
return false;
}
}
bool PutByIdVariant::reallocatesStorage() const
{
switch (kind()) {
case Transition:
return oldStructureForTransition()->outOfLineCapacity() != newStructure()->outOfLineCapacity();
case Setter:
return true;
default:
return false;
}
}
bool PutByIdVariant::makesCalls() const
{
return kind() == Setter;
}
bool PutByIdVariant::attemptToMerge(const PutByIdVariant& other)
{
if (m_offset != other.m_offset)
return false;
if (m_requiredType != other.m_requiredType)
return false;
switch (m_kind) {
case Replace: {
switch (other.m_kind) {
case Replace: {
ASSERT(m_conditionSet.isEmpty());
ASSERT(other.m_conditionSet.isEmpty());
m_oldStructure.merge(other.m_oldStructure);
return true;
}
case Transition: {
PutByIdVariant newVariant = other;
if (newVariant.attemptToMergeTransitionWithReplace(*this)) {
*this = newVariant;
return true;
}
return false;
}
default:
return false;
}
}
case Transition:
switch (other.m_kind) {
case Replace:
return attemptToMergeTransitionWithReplace(other);
default:
return false;
}
default:
return false;
}
}
bool PutByIdVariant::attemptToMergeTransitionWithReplace(const PutByIdVariant& replace)
{
ASSERT(m_kind == Transition);
ASSERT(replace.m_kind == Replace);
ASSERT(m_offset == replace.m_offset);
ASSERT(!replace.writesStructures());
ASSERT(!replace.reallocatesStorage());
ASSERT(replace.conditionSet().isEmpty());
// This sort of merging only works when we have one path along which we add a new field which
// transitions to structure S while the other path was already on structure S. This doesn't
// work if we need to reallocate anything or if the replace path is polymorphic.
if (reallocatesStorage())
return false;
if (replace.m_oldStructure.onlyStructure() != m_newStructure)
return false;
m_oldStructure.merge(m_newStructure);
return true;
}
void PutByIdVariant::dump(PrintStream& out) const
{
dumpInContext(out, 0);
}
void PutByIdVariant::dumpInContext(PrintStream& out, DumpContext* context) const
{
switch (kind()) {
case NotSet:
out.print("<empty>");
return;
case Replace:
out.print(
"<Replace: ", inContext(structure(), context), ", offset = ", offset(), ", ",
inContext(requiredType(), context), ">");
return;
case Transition:
out.print(
"<Transition: ", inContext(oldStructure(), context), " -> ",
pointerDumpInContext(newStructure(), context), ", [",
inContext(m_conditionSet, context), "], offset = ", offset(), ", ",
inContext(requiredType(), context), ">");
return;
case Setter:
out.print(
"<Setter: ", inContext(structure(), context), ", [",
inContext(m_conditionSet, context), "]");
out.print(", offset = ", m_offset);
out.print(", call = ", *m_callLinkStatus);
out.print(">");
return;
}
RELEASE_ASSERT_NOT_REACHED();
}
} // namespace JSC