PolyProtoAccessChain.cpp [plain text]
#include "config.h"
#include "PolyProtoAccessChain.h"
#include "JSObject.h"
namespace JSC {
std::unique_ptr<PolyProtoAccessChain> PolyProtoAccessChain::create(JSGlobalObject* globalObject, JSCell* base, const PropertySlot& slot, bool& usesPolyProto)
{
JSObject* target = slot.isUnset() ? nullptr : slot.slotBase();
return create(globalObject, base, target, usesPolyProto);
}
std::unique_ptr<PolyProtoAccessChain> PolyProtoAccessChain::create(JSGlobalObject* globalObject, JSCell* base, JSObject* target, bool& usesPolyProto)
{
JSCell* current = base;
VM& vm = *base->vm();
bool found = false;
usesPolyProto = false;
std::unique_ptr<PolyProtoAccessChain> result(new PolyProtoAccessChain());
for (unsigned iterationNumber = 0; true; ++iterationNumber) {
Structure* structure = current->structure(vm);
if (!structure->propertyAccessesAreCacheable())
return nullptr;
if (structure->isProxy())
return nullptr;
if (structure->isDictionary()) {
ASSERT(structure->isObject());
if (structure->hasBeenFlattenedBefore())
return nullptr;
structure->flattenDictionaryStructure(vm, asObject(current));
}
if (iterationNumber)
result->m_chain.append(structure);
else
RELEASE_ASSERT(current == base);
if (current == target) {
found = true;
break;
}
usesPolyProto |= structure->hasPolyProto();
JSValue prototype = structure->prototypeForLookup(globalObject, current);
if (prototype.isNull())
break;
current = asObject(prototype);
}
if (!found && !!target)
return nullptr;
return result;
}
bool PolyProtoAccessChain::needImpurePropertyWatchpoint() const
{
for (Structure* structure : m_chain) {
if (structure->needImpurePropertyWatchpoint())
return true;
}
return false;
}
bool PolyProtoAccessChain::operator==(const PolyProtoAccessChain& other) const
{
return m_chain == other.m_chain;
}
void PolyProtoAccessChain::dump(Structure* baseStructure, PrintStream& out) const
{
out.print("PolyPolyProtoAccessChain: [\n");
forEach(baseStructure, [&] (Structure* structure, bool) {
out.print("\t");
structure->dump(out);
out.print("\n");
});
}
}