#ifndef HandleStack_h
#define HandleStack_h
#include <wtf/Assertions.h>
#include <wtf/BlockStack.h>
#include "Handle.h"
namespace JSC {
class LocalScope;
class HeapRootVisitor;
class HandleStack {
public:
class Frame {
public:
HandleSlot m_next;
HandleSlot m_end;
};
HandleStack();
void enterScope(Frame&);
void leaveScope(Frame&);
HandleSlot push();
void visit(HeapRootVisitor&);
private:
JS_EXPORT_PRIVATE void grow();
void zapTo(Frame&);
HandleSlot findFirstAfter(HandleSlot);
#ifndef NDEBUG
size_t m_scopeDepth;
#endif
BlockStack<JSValue> m_blockStack;
Frame m_frame;
};
inline void HandleStack::enterScope(Frame& lastFrame)
{
#ifndef NDEBUG
++m_scopeDepth;
#endif
lastFrame = m_frame;
}
inline void HandleStack::zapTo(Frame& lastFrame)
{
#ifdef NDEBUG
UNUSED_PARAM(lastFrame);
#else
const Vector<HandleSlot>& blocks = m_blockStack.blocks();
if (lastFrame.m_end != m_frame.m_end) { int i = blocks.size() - 1;
for ( ; blocks[i] + m_blockStack.blockLength != lastFrame.m_end; --i) {
for (int j = m_blockStack.blockLength - 1; j >= 0; --j)
blocks[i][j] = JSValue();
}
for (HandleSlot it = blocks[i] + m_blockStack.blockLength - 1; it != lastFrame.m_next - 1; --it)
*it = JSValue();
return;
}
for (HandleSlot it = m_frame.m_next - 1; it != lastFrame.m_next - 1; --it)
*it = JSValue();
#endif
}
inline void HandleStack::leaveScope(Frame& lastFrame)
{
#ifndef NDEBUG
--m_scopeDepth;
#endif
zapTo(lastFrame);
if (lastFrame.m_end != m_frame.m_end) m_blockStack.shrink(lastFrame.m_end);
m_frame = lastFrame;
}
inline HandleSlot HandleStack::push()
{
ASSERT(m_scopeDepth); if (m_frame.m_next == m_frame.m_end)
grow();
return m_frame.m_next++;
}
}
#endif