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/*
* Copyright (C) 2008-2022 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 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.
*/
#pragma once
#if ENABLE(C_LOOP)
#include "Register.h"
#include <wtf/Noncopyable.h>
#include <wtf/PageReservation.h>
namespace JSC {
class CodeBlockSet;
class ConservativeRoots;
class JITStubRoutineSet;
class VM;
class LLIntOffsetsExtractor;
class CLoopStack {
WTF_MAKE_NONCOPYABLE(CLoopStack);
public:
// Allow 8k of excess registers before we start trying to reap the stack
static constexpr ptrdiff_t maxExcessCapacity = 8 * 1024;
CLoopStack(VM&);
~CLoopStack();
bool ensureCapacityFor(Register* newTopOfStack);
bool containsAddress(Register* address) { return (lowAddress() <= address && address < highAddress()); }
static size_t committedByteCount();
void gatherConservativeRoots(ConservativeRoots&, JITStubRoutineSet&, CodeBlockSet&);
void sanitizeStack();
inline void* currentStackPointer() const;
void setCurrentStackPointer(void* sp) { m_currentStackPointer = sp; }
size_t size() const { return highAddress() - lowAddress(); }
void setSoftReservedZoneSize(size_t);
bool isSafeToRecurse() const;
private:
Register* lowAddress() const
{
return m_end;
}
WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
Register* highAddress() const
{
return reinterpret_cast_ptr<Register*>(static_cast<char*>(m_reservation.base()) + m_reservation.size());
}
WTF_ALLOW_UNSAFE_BUFFER_USAGE_END
Register* reservationTop() const
{
char* reservationTop = static_cast<char*>(m_reservation.base());
return reinterpret_cast_ptr<Register*>(reservationTop);
}
bool grow(Register* newTopOfStack);
void releaseExcessCapacity();
void addToCommittedByteCount(long);
void setCLoopStackLimit(Register* newTopOfStack);
VM& m_vm;
CallFrame*& m_topCallFrame;
// The following is always true:
// reservationTop() <= m_commitTop <= m_end <= m_currentStackPointer <= highAddress()
Register* m_end; // lowest address of JS allocatable stack memory.
Register* m_commitTop; // lowest address of committed memory.
PageReservation m_reservation;
void* m_lastStackPointer;
void* m_currentStackPointer;
ptrdiff_t m_softReservedZoneSizeInRegisters;
friend class LLIntOffsetsExtractor;
};
} // namespace JSC
#endif // ENABLE(C_LOOP)
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