void StructureRareData::setObjectToStringValue(ExecState* exec, VM& vm, Structure* ownStructure, JSString* value, PropertySlot toStringTagSymbolSlot)
{
if (m_giveUpOnObjectToStringValueCache)
return;
ObjectPropertyConditionSet conditionSet;
if (toStringTagSymbolSlot.isValue()) {
// We don't handle the own property case of Symbol.toStringTag because we would never know if a new
// object transitioning to the same structure had the same value stored in Symbol.toStringTag.
// Additionally, this is a super unlikely case anyway.
if (!toStringTagSymbolSlot.isCacheable() || toStringTagSymbolSlot.slotBase()->structure(vm) == ownStructure)
return;
// This will not create a condition for the current structure but that is good because we know the Symbol.toStringTag
// is not on the ownStructure so we will transisition if one is added and this cache will no longer be used.
conditionSet = generateConditionsForPrototypePropertyHit(vm, this, exec, ownStructure, toStringTagSymbolSlot.slotBase(), vm.propertyNames->toStringTagSymbol.impl());
ASSERT(!conditionSet.isValid() || conditionSet.hasOneSlotBaseCondition());
} else if (toStringTagSymbolSlot.isUnset())
conditionSet = generateConditionsForPropertyMiss(vm, this, exec, ownStructure, vm.propertyNames->toStringTagSymbol.impl());
else
return;
if (!conditionSet.isValid()) {
m_giveUpOnObjectToStringValueCache = true;
return;
}
ObjectPropertyCondition equivCondition;
for (const ObjectPropertyCondition& condition : conditionSet) {
if (condition.condition().kind() == PropertyCondition::Presence) {
ASSERT(isValidOffset(condition.offset()));
condition.object()->structure(vm)->startWatchingPropertyForReplacements(vm, condition.offset());
equivCondition = condition.attemptToMakeEquivalenceWithoutBarrier();
// The equivalence condition won't be watchable if we have already seen a replacement.
if (!equivCondition.isWatchable()) {
m_giveUpOnObjectToStringValueCache = true;
return;
}
} else if (!condition.isWatchable()) {
m_giveUpOnObjectToStringValueCache = true;
return;
}
}
ASSERT(conditionSet.structuresEnsureValidity());
for (ObjectPropertyCondition condition : conditionSet) {
if (condition.condition().kind() == PropertyCondition::Presence) {
m_objectToStringAdaptiveInferredValueWatchpoint = std::make_unique<ObjectToStringAdaptiveInferredPropertyValueWatchpoint>(equivCondition, this);
m_objectToStringAdaptiveInferredValueWatchpoint->install();
} else
m_objectToStringAdaptiveWatchpointSet.add(condition, this)->install();
}
m_objectToStringValue.set(vm, this, value);
}
PutByIdStatus PutByIdStatus::computeForStubInfo(
const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
UniquedStringImpl* uid, CallLinkStatus::ExitSiteData callExitSiteData)
{
if (!stubInfo || !stubInfo->everConsidered)
return PutByIdStatus();
if (stubInfo->tookSlowPath)
return PutByIdStatus(TakesSlowPath);
switch (stubInfo->cacheType) {
case CacheType::Unset:
// This means that we attempted to cache but failed for some reason.
return PutByIdStatus(TakesSlowPath);
case CacheType::PutByIdReplace: {
PropertyOffset offset =
stubInfo->u.byIdSelf.baseObjectStructure->getConcurrently(uid);
if (isValidOffset(offset)) {
return PutByIdVariant::replace(
stubInfo->u.byIdSelf.baseObjectStructure.get(), offset, InferredType::Top);
}
return PutByIdStatus(TakesSlowPath);
}
case CacheType::Stub: {
PolymorphicAccess* list = stubInfo->u.stub;
PutByIdStatus result;
result.m_state = Simple;
State slowPathState = TakesSlowPath;
for (unsigned i = 0; i < list->size(); ++i) {
const AccessCase& access = list->at(i);
if (access.doesCalls())
slowPathState = MakesCalls;
}
for (unsigned i = 0; i < list->size(); ++i) {
const AccessCase& access = list->at(i);
if (access.viaProxy())
return PutByIdStatus(slowPathState);
PutByIdVariant variant;
switch (access.type()) {
case AccessCase::Replace: {
Structure* structure = access.structure();
PropertyOffset offset = structure->getConcurrently(uid);
if (!isValidOffset(offset))
return PutByIdStatus(slowPathState);
variant = PutByIdVariant::replace(
structure, offset, structure->inferredTypeDescriptorFor(uid));
break;
}
case AccessCase::Transition: {
PropertyOffset offset =
access.newStructure()->getConcurrently(uid);
if (!isValidOffset(offset))
return PutByIdStatus(slowPathState);
ObjectPropertyConditionSet conditionSet = access.conditionSet();
if (!conditionSet.structuresEnsureValidity())
return PutByIdStatus(slowPathState);
variant = PutByIdVariant::transition(
access.structure(), access.newStructure(), conditionSet, offset,
access.newStructure()->inferredTypeDescriptorFor(uid));
break;
}
case AccessCase::Setter: {
Structure* structure = access.structure();
ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
structure, access.conditionSet(), uid);
switch (complexGetStatus.kind()) {
case ComplexGetStatus::ShouldSkip:
continue;
case ComplexGetStatus::TakesSlowPath:
return PutByIdStatus(slowPathState);
case ComplexGetStatus::Inlineable: {
CallLinkInfo* callLinkInfo = access.callLinkInfo();
ASSERT(callLinkInfo);
std::unique_ptr<CallLinkStatus> callLinkStatus =
std::make_unique<CallLinkStatus>(
CallLinkStatus::computeFor(
locker, profiledBlock, *callLinkInfo, callExitSiteData));
variant = PutByIdVariant::setter(
structure, complexGetStatus.offset(), complexGetStatus.conditionSet(),
WTFMove(callLinkStatus));
} }
break;
}
case AccessCase::CustomSetter:
return PutByIdStatus(MakesCalls);
default:
return PutByIdStatus(slowPathState);
}
if (!result.appendVariant(variant))
return PutByIdStatus(slowPathState);
}
return result;
}
default:
return PutByIdStatus(TakesSlowPath);
}
}