JavaScriptCore/bytecompiler/RegisterID.h

   1 /*
   2  * Copyright (C) 2008 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 Computer, 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 RegisterID_h
  30 #define RegisterID_h
  31
  32 #include <wtf/Assertions.h>
  33 #include <wtf/Noncopyable.h>
  34 #include <wtf/VectorTraits.h>
  35
  36 namespace JSC {
  37
  38     class RegisterID : public Noncopyable {
  39     public:
  40         RegisterID()
  41             : m_refCount(0)
  42             , m_isTemporary(false)
  43 #ifndef NDEBUG
  44             , m_didSetIndex(false)
  45 #endif
  46         {
  47         }
  48
  49         explicit RegisterID(int index)
  50             : m_refCount(0)
  51             , m_index(index)
  52             , m_isTemporary(false)
  53 #ifndef NDEBUG
  54             , m_didSetIndex(true)
  55 #endif
  56         {
  57         }
  58
  59         void setIndex(int index)
  60         {
  61             ASSERT(!m_refCount);
  62 #ifndef NDEBUG
  63             m_didSetIndex = true;
  64 #endif
  65             m_index = index;
  66         }
  67
  68         void setTemporary()
  69         {
  70             m_isTemporary = true;
  71         }
  72
  73         int index() const
  74         {
  75             ASSERT(m_didSetIndex);
  76             return m_index;
  77         }
  78
  79         bool isTemporary()
  80         {
  81             return m_isTemporary;
  82         }
  83
  84         void ref()
  85         {
  86             ++m_refCount;
  87         }
  88
  89         void deref()
  90         {
  91             --m_refCount;
  92             ASSERT(m_refCount >= 0);
  93         }
  94
  95         int refCount() const
  96         {
  97             return m_refCount;
  98         }
  99
 100     private:
 101
 102         int m_refCount;
 103         int m_index;
 104         bool m_isTemporary;
 105 #ifndef NDEBUG
 106         bool m_didSetIndex;
 107 #endif
 108     };
 109
 110 } // namespace JSC
 111
 112 namespace WTF {
 113
 114     template<> struct VectorTraits<JSC::RegisterID> : VectorTraitsBase<true, JSC::RegisterID> {
 115         static const bool needsInitialization = true;
 116         static const bool canInitializeWithMemset = true; // Default initialization just sets everything to 0 or false, so this is safe.
 117     };
 118
 119 } // namespace WTF
 120
 121 #endif // RegisterID_h