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/*
* Copyright (C) 2008 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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.
*/
#ifndef Label_h
#define Label_h
#include "CodeBlock.h"
#include "Instruction.h"
#include <wtf/Assertions.h>
#include <wtf/Vector.h>
#include <limits.h>
namespace JSC {
class BytecodeGenerator;
class Label {
public:
explicit Label(BytecodeGenerator* generator)
: m_refCount(0)
, m_location(invalidLocation)
, m_generator(generator)
{
}
void setLocation(unsigned);
int bind(int opcode, int offset) const
{
if (m_location == invalidLocation) {
m_unresolvedJumps.append(std::make_pair(opcode, offset));
return 0;
}
return m_location - opcode;
}
void ref() { ++m_refCount; }
void deref()
{
--m_refCount;
ASSERT(m_refCount >= 0);
}
int refCount() const { return m_refCount; }
bool isForward() const { return m_location == invalidLocation; }
int bind()
{
ASSERT(!isForward());
return bind(0, 0);
}
private:
typedef Vector<std::pair<int, int>, 8> JumpVector;
static const unsigned invalidLocation = UINT_MAX;
int m_refCount;
unsigned m_location;
BytecodeGenerator* m_generator;
mutable JumpVector m_unresolvedJumps;
};
} // namespace JSC
#endif // Label_h
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