JavaScriptCore/runtime/JSTypeInfo.h

   1 // -*- mode: c++; c-basic-offset: 4 -*-
   2 /*
   3  * Copyright (C) 2008 Apple Inc. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   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  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef JSTypeInfo_h
  28 #define JSTypeInfo_h
  29
  30 // This file would be called TypeInfo.h, but that conflicts with <typeinfo.h>
  31 // in the STL on systems without case-sensitive file systems.
  32
  33 #include "JSType.h"
  34
  35 namespace JSC {
  36
  37     // WebCore uses MasqueradesAsUndefined to make document.all and style.filter undetectable.
  38     static const unsigned MasqueradesAsUndefined = 1;
  39     static const unsigned ImplementsHasInstance = 1 << 1;
  40     static const unsigned OverridesHasInstance = 1 << 2;
  41     static const unsigned ImplementsDefaultHasInstance = 1 << 3;
  42     static const unsigned NeedsThisConversion = 1 << 4;
  43     static const unsigned OverridesGetOwnPropertySlot = 1 << 5;
  44     static const unsigned OverridesMarkChildren = 1 << 6;
  45     static const unsigned OverridesGetPropertyNames = 1 << 7;
  46
  47     class TypeInfo {
  48         friend class JIT;
  49     public:
  50         TypeInfo(JSType type, unsigned flags = 0)
  51             : m_type(type)
  52         {
  53             // ImplementsDefaultHasInstance means (ImplementsHasInstance & !OverridesHasInstance)
  54             if ((flags & (ImplementsHasInstance | OverridesHasInstance)) == ImplementsHasInstance)
  55                 m_flags = flags | ImplementsDefaultHasInstance;
  56             else
  57                 m_flags = flags;
  58         }
  59
  60         JSType type() const { return m_type; }
  61
  62         bool masqueradesAsUndefined() const { return m_flags & MasqueradesAsUndefined; }
  63         bool implementsHasInstance() const { return m_flags & ImplementsHasInstance; }
  64         bool overridesHasInstance() const { return m_flags & OverridesHasInstance; }
  65         bool needsThisConversion() const { return m_flags & NeedsThisConversion; }
  66         bool overridesGetOwnPropertySlot() const { return m_flags & OverridesGetOwnPropertySlot; }
  67         bool overridesMarkChildren() const { return m_flags & OverridesMarkChildren; }
  68         bool overridesGetPropertyNames() const { return m_flags & OverridesGetPropertyNames; }
  69         unsigned flags() const { return m_flags; }
  70
  71     private:
  72         JSType m_type;
  73         unsigned m_flags;
  74     };
  75
  76 }
  77
  78 #endif // JSTypeInfo_h