interpreter/JSStackInlines.h

   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
  34 namespace JSC {
  35
  36 inline 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
  48 inline Register* JSStack::topOfFrameFor(CallFrame* frame)
  49 {
  50     if (UNLIKELY(!frame))
  51         return baseOfStack();
  52     return frame->topOfFrame() - 1;
  53 }
  54
  55 inline Register* JSStack::topOfStack()
  56 {
  57     return topOfFrameFor(m_topCallFrame);
  58 }
  59
  60 inline 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
  75 inline 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
  83 inline 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