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
38namespace 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 Callee,
62 ArgumentCount,
63 CallFrameHeaderSize,
64
65 // The following entries are not part of the CallFrameHeader but are provided here as a convenience:
66 ThisArgument = CallFrameHeaderSize,
67 FirstArgument,
68 };
69
70 // Allow 8k of excess registers before we start trying to reap the stack
71 static const ptrdiff_t maxExcessCapacity = 8 * 1024;
72
73 JSStack(VM&);
74
75 bool ensureCapacityFor(Register* newTopOfStack);
76
77 bool containsAddress(Register* address) { return (lowAddress() <= address && address < highAddress()); }
78 static size_t committedByteCount();
79
80#if ENABLE(JIT)
81 void gatherConservativeRoots(ConservativeRoots&, JITStubRoutineSet&, CodeBlockSet&) { }
82 void sanitizeStack() { }
83#else
84 ~JSStack();
85
86 void gatherConservativeRoots(ConservativeRoots&, JITStubRoutineSet&, CodeBlockSet&);
87 void sanitizeStack();
88
89 Register* baseOfStack() const
90 {
91 return highAddress() - 1;
92 }
93
94 size_t size() const { return highAddress() - lowAddress(); }
95
96 void setReservedZoneSize(size_t);
97
98 inline Register* topOfStack();
99#endif // ENABLE(JIT)
100
101 private:
102
103#if !ENABLE(JIT)
104 Register* lowAddress() const
105 {
106 return m_end + 1;
107 }
108
109 Register* highAddress() const
110 {
111 return reinterpret_cast_ptr<Register*>(static_cast<char*>(m_reservation.base()) + m_reservation.size());
112 }
113#else
114 Register* lowAddress() const;
115 Register* highAddress() const;
116#endif // !ENABLE(JIT)
117
118#if !ENABLE(JIT)
119 inline Register* topOfFrameFor(CallFrame*);
120
121 Register* reservationTop() const
122 {
123 char* reservationTop = static_cast<char*>(m_reservation.base());
124 return reinterpret_cast_ptr<Register*>(reservationTop);
125 }
126
127 bool grow(Register* newTopOfStack);
128 bool growSlowCase(Register* newTopOfStack);
129 void shrink(Register* newTopOfStack);
130 void releaseExcessCapacity();
131 void addToCommittedByteCount(long);
132
133 void setStackLimit(Register* newTopOfStack);
134#endif // !ENABLE(JIT)
135
136 VM& m_vm;
137 CallFrame*& m_topCallFrame;
138#if !ENABLE(JIT)
139 Register* m_end;
140 Register* m_commitTop;
141 PageReservation m_reservation;
142 Register* m_lastStackTop;
143 ptrdiff_t m_reservedZoneSizeInRegisters;
144#endif // !ENABLE(JIT)
145
146 friend class LLIntOffsetsExtractor;
147 };
148
149} // namespace JSC
150
151#endif // JSStack_h
152