1/*
2 * Copyright (C) 2012, 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 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef JSStackInlines_h
27#define JSStackInlines_h
28
29#include "CallFrame.h"
30#include "CodeBlock.h"
31#include "JSStack.h"
32#include "VM.h"
33
34namespace JSC {
35
36inline bool JSStack::ensureCapacityFor(Register* newTopOfStack)
37{
38#if !ENABLE(JIT)
39 return grow(newTopOfStack);
40#else
41 ASSERT(wtfThreadData().stack().isGrowingDownward());
42 return newTopOfStack >= m_vm.stackLimit();
43#endif
44}
45
46#if !ENABLE(JIT)
47
48inline Register* JSStack::topOfFrameFor(CallFrame* frame)
49{
50 if (UNLIKELY(!frame))
51 return baseOfStack();
52 return frame->topOfFrame() - 1;
53}
54
55inline Register* JSStack::topOfStack()
56{
57 return topOfFrameFor(m_topCallFrame);
58}
59
60inline void JSStack::shrink(Register* newTopOfStack)
61{
62 Register* newEnd = newTopOfStack - 1;
63 if (newEnd >= m_end)
64 return;
65 setStackLimit(newTopOfStack);
66 // Note: Clang complains of an unresolved linkage to maxExcessCapacity if
67 // invoke std::max() with it as an argument. To work around this, we first
68 // assign the constant to a local variable, and use the local instead.
69 ptrdiff_t maxExcessCapacity = JSStack::maxExcessCapacity;
70 ptrdiff_t maxExcessInRegisters = std::max(maxExcessCapacity, m_reservedZoneSizeInRegisters);
71 if (m_end == baseOfStack() && (highAddress() - m_commitTop) >= maxExcessInRegisters)
72 releaseExcessCapacity();
73}
74
75inline bool JSStack::grow(Register* newTopOfStack)
76{
77 Register* newEnd = newTopOfStack - 1;
78 if (newEnd >= m_end)
79 return true;
80 return growSlowCase(newTopOfStack);
81}
82
83inline void JSStack::setStackLimit(Register* newTopOfStack)
84{
85 Register* newEnd = newTopOfStack - 1;
86 m_end = newEnd;
87 m_vm.setJSStackLimit(newTopOfStack);
88}
89
90#endif // !ENABLE(JIT)
91
92} // namespace JSC
93
94#endif // JSStackInlines_h
95