IntendedStructureChain.cpp [plain text]
#include "config.h"
#include "IntendedStructureChain.h"
#include "CodeBlock.h"
#include "JSCInlines.h"
#include "StructureChain.h"
#include <wtf/CommaPrinter.h>
namespace JSC {
IntendedStructureChain::IntendedStructureChain(JSGlobalObject* globalObject, Structure* head)
: m_globalObject(globalObject)
, m_head(head)
{
JSValue prototype = head->prototypeForLookup(globalObject);
if (prototype.isNull())
return;
for (Structure* current = asObject(prototype)->structure(); current; current = current->storedPrototypeStructure())
m_vector.append(current);
}
IntendedStructureChain::IntendedStructureChain(CodeBlock* codeBlock, Structure* head, Structure* prototypeStructure)
: m_globalObject(codeBlock->globalObject())
, m_head(head)
{
m_vector.append(prototypeStructure);
}
IntendedStructureChain::IntendedStructureChain(CodeBlock* codeBlock, Structure* head, StructureChain* chain)
: m_globalObject(codeBlock->globalObject())
, m_head(head)
{
for (unsigned i = 0; chain->head()[i]; ++i)
m_vector.append(chain->head()[i].get());
}
IntendedStructureChain::IntendedStructureChain(CodeBlock* codeBlock, Structure* head, StructureChain* chain, unsigned count)
: m_globalObject(codeBlock->globalObject())
, m_head(head)
{
for (unsigned i = 0; i < count; ++i)
m_vector.append(chain->head()[i].get());
}
IntendedStructureChain::~IntendedStructureChain()
{
}
bool IntendedStructureChain::isStillValid() const
{
JSValue currentPrototype = m_head->prototypeForLookup(m_globalObject);
for (unsigned i = 0; i < m_vector.size(); ++i) {
if (asObject(currentPrototype)->structure() != m_vector[i])
return false;
currentPrototype = m_vector[i]->storedPrototype();
}
return true;
}
bool IntendedStructureChain::matches(StructureChain* chain) const
{
for (unsigned i = 0; i < m_vector.size(); ++i) {
if (m_vector[i] != chain->head()[i].get())
return false;
}
if (chain->head()[m_vector.size()])
return false;
return true;
}
StructureChain* IntendedStructureChain::chain(VM& vm) const
{
ASSERT(isStillValid());
StructureChain* result = StructureChain::create(vm, m_head);
ASSERT(matches(result));
return result;
}
bool IntendedStructureChain::mayInterceptStoreTo(VM& vm, StringImpl* uid)
{
for (unsigned i = 0; i < m_vector.size(); ++i) {
unsigned attributes;
JSCell* specificValue;
PropertyOffset offset = m_vector[i]->getConcurrently(vm, uid, attributes, specificValue);
if (!isValidOffset(offset))
continue;
if (attributes & (ReadOnly | Accessor))
return true;
return false;
}
return false;
}
bool IntendedStructureChain::isNormalized()
{
if (m_head->isProxy())
return false;
for (unsigned i = 0; i < m_vector.size(); ++i) {
Structure* structure = m_vector[i];
if (structure->isProxy())
return false;
if (structure->isDictionary())
return false;
}
return true;
}
JSObject* IntendedStructureChain::terminalPrototype() const
{
ASSERT(!m_vector.isEmpty());
if (m_vector.size() == 1)
return asObject(m_head->prototypeForLookup(m_globalObject));
return asObject(m_vector[m_vector.size() - 2]->storedPrototype());
}
void IntendedStructureChain::visitChildren(SlotVisitor& visitor)
{
visitor.appendUnbarrieredPointer(&m_globalObject);
visitor.appendUnbarrieredPointer(&m_head);
for (unsigned i = m_vector.size(); i--;)
visitor.appendUnbarrieredPointer(&m_vector[i]);
}
void IntendedStructureChain::dump(PrintStream& out) const
{
dumpInContext(out, 0);
}
void IntendedStructureChain::dumpInContext(PrintStream& out, DumpContext* context) const
{
out.print(
"(global = ", RawPointer(m_globalObject), ", head = ",
pointerDumpInContext(m_head, context), ", vector = [");
CommaPrinter comma;
for (unsigned i = 0; i < m_vector.size(); ++i)
out.print(comma, pointerDumpInContext(m_vector[i], context));
out.print("])");
}
}