interpreter/JSStack.h

   1 /*
   2  * Copyright (C) 2008, 2009, 2013, 2014 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef JSStack_h
  30 #define JSStack_h
  31
  32 #include "ExecutableAllocator.h"
  33 #include "Register.h"
  34 #include <wtf/Noncopyable.h>
  35 #include <wtf/PageReservation.h>
  36 #include <wtf/VMTags.h>
  37
  38 namespace JSC {
  39
  40     class CodeBlockSet;
  41     class ConservativeRoots;
  42     class ExecState;
  43     class JITStubRoutineSet;
  44     class VM;
  45     class LLIntOffsetsExtractor;
  46
  47     struct Instruction;
  48     typedef ExecState CallFrame;
  49
  50     struct CallerFrameAndPC {
  51         CallFrame* callerFrame;
  52         Instruction* pc;
  53     };
  54
  55     class JSStack {
  56         WTF_MAKE_NONCOPYABLE(JSStack);
  57     public:
  58         enum CallFrameHeaderEntry {
  59             CallerFrameAndPCSize = sizeof(CallerFrameAndPC) / sizeof(Register),
  60             CodeBlock = CallerFrameAndPCSize,
  61             ScopeChain,
  62             Callee,
  63             ArgumentCount,
  64             CallFrameHeaderSize,
  65
  66             // The following entries are not part of the CallFrameHeader but are provided here as a convenience:
  67             ThisArgument = CallFrameHeaderSize,
  68             FirstArgument,
  69         };
  70
  71         static const size_t commitSize = 16 * 1024;
  72         // Allow 8k of excess registers before we start trying to reap the stack
  73         static const ptrdiff_t maxExcessCapacity = 8 * 1024;
  74
  75         JSStack(VM&);
  76
  77         bool ensureCapacityFor(Register* newTopOfStack);
  78
  79         bool containsAddress(Register* address) { return (lowAddress() <= address && address < highAddress()); }
  80         static size_t committedByteCount();
  81
  82 #if ENABLE(JIT)
  83         void gatherConservativeRoots(ConservativeRoots&) { }
  84         void gatherConservativeRoots(ConservativeRoots&, JITStubRoutineSet&, CodeBlockSet&) { }
  85         void sanitizeStack() { }
  86         static void initializeThreading() { }
  87 #else
  88         ~JSStack();
  89
  90         void gatherConservativeRoots(ConservativeRoots&);
  91         void gatherConservativeRoots(ConservativeRoots&, JITStubRoutineSet&, CodeBlockSet&);
  92         void sanitizeStack();
  93
  94         Register* baseOfStack() const
  95         {
  96             return highAddress() - 1;
  97         }
  98
  99         size_t size() const { return highAddress() - lowAddress(); }
 100
 101         static void initializeThreading();
 102
 103         void setReservedZoneSize(size_t);
 104
 105         inline Register* topOfStack();
 106 #endif // ENABLE(JIT)
 107
 108     private:
 109
 110 #if !ENABLE(JIT)
 111         Register* lowAddress() const
 112         {
 113             return m_end + 1;
 114         }
 115
 116         Register* highAddress() const
 117         {
 118             return reinterpret_cast_ptr<Register*>(static_cast<char*>(m_reservation.base()) + m_reservation.size());
 119         }
 120 #else
 121         Register* lowAddress() const;
 122         Register* highAddress() const;
 123 #endif // !ENABLE(JIT)
 124
 125 #if !ENABLE(JIT)
 126         inline Register* topOfFrameFor(CallFrame*);
 127
 128         Register* reservationTop() const
 129         {
 130             char* reservationTop = static_cast<char*>(m_reservation.base());
 131             return reinterpret_cast_ptr<Register*>(reservationTop);
 132         }
 133
 134         bool grow(Register* newTopOfStack);
 135         bool growSlowCase(Register* newTopOfStack);
 136         void shrink(Register* newTopOfStack);
 137         void releaseExcessCapacity();
 138         void addToCommittedByteCount(long);
 139
 140         void setStackLimit(Register* newTopOfStack);
 141 #endif // !ENABLE(JIT)
 142
 143         VM& m_vm;
 144         CallFrame*& m_topCallFrame;
 145 #if !ENABLE(JIT)
 146         Register* m_end;
 147         Register* m_commitTop;
 148         PageReservation m_reservation;
 149         Register* m_lastStackTop;
 150         ptrdiff_t m_reservedZoneSizeInRegisters;
 151 #endif // !ENABLE(JIT)
 152
 153         friend class LLIntOffsetsExtractor;
 154     };
 155
 156 } // namespace JSC
 157
 158 #endif // JSStack_h