/* | |
* 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 Label { | |
public: | |
explicit Label(CodeBlock* codeBlock) | |
: m_refCount(0) | |
, m_location(invalidLocation) | |
, m_codeBlock(codeBlock) | |
{ | |
} | |
void setLocation(unsigned location) | |
{ | |
m_location = location; | |
unsigned size = m_unresolvedJumps.size(); | |
for (unsigned i = 0; i < size; ++i) | |
m_codeBlock->instructions()[m_unresolvedJumps[i].second].u.operand = m_location - m_unresolvedJumps[i].first; | |
} | |
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; } | |
private: | |
typedef Vector<std::pair<int, int>, 8> JumpVector; | |
static const unsigned invalidLocation = UINT_MAX; | |
int m_refCount; | |
unsigned m_location; | |
CodeBlock* m_codeBlock; | |
mutable JumpVector m_unresolvedJumps; | |
}; | |
} // namespace JSC | |
#endif // Label_h |