| 1 | /* | 
| 2 |  * Copyright (C) 2009 Google 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 are | 
| 6 |  * met: | 
| 7 |  * | 
| 8 |  *     * Redistributions of source code must retain the above copyright | 
| 9 |  * notice, this list of conditions and the following disclaimer. | 
| 10 |  *     * Redistributions in binary form must reproduce the above | 
| 11 |  * copyright notice, this list of conditions and the following disclaimer | 
| 12 |  * in the documentation and/or other materials provided with the | 
| 13 |  * distribution. | 
| 14 |  *     * Neither the name of Google Inc. nor the names of its | 
| 15 |  * contributors may be used to endorse or promote products derived from | 
| 16 |  * this software without specific prior written permission. | 
| 17 |  * | 
| 18 |  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
| 19 |  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
| 20 |  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 
| 21 |  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | 
| 22 |  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | 
| 23 |  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | 
| 24 |  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | 
| 25 |  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | 
| 26 |  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
| 27 |  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 
| 28 |  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
| 29 |  */ | 
| 30 |  | 
| 31 | #ifndef PtrAndFlags_h | 
| 32 | #define PtrAndFlags_h | 
| 33 |  | 
| 34 | #include <wtf/Assertions.h> | 
| 35 |  | 
| 36 | namespace WTF { | 
| 37 |     template<class T, typename FlagEnum> class PtrAndFlagsBase { | 
| 38 |     public: | 
| 39 |         bool isFlagSet(FlagEnum flagNumber) const { ASSERT(flagNumber < 2); return m_ptrAndFlags & (1 << flagNumber); } | 
| 40 |         void setFlag(FlagEnum flagNumber) { ASSERT(flagNumber < 2); m_ptrAndFlags |= (1 << flagNumber);} | 
| 41 |         void clearFlag(FlagEnum flagNumber) { ASSERT(flagNumber < 2); m_ptrAndFlags &= ~(1 << flagNumber);} | 
| 42 |         T* get() const { return reinterpret_cast<T*>(m_ptrAndFlags & ~3); } | 
| 43 |         void set(T* ptr) | 
| 44 |         { | 
| 45 |             ASSERT(!(reinterpret_cast<intptr_t>(ptr) & 3)); | 
| 46 |             m_ptrAndFlags = reinterpret_cast<intptr_t>(ptr) | (m_ptrAndFlags & 3); | 
| 47 | #ifndef NDEBUG | 
| 48 |             m_leaksPtr = ptr; | 
| 49 | #endif | 
| 50 |         } | 
| 51 |  | 
| 52 |         bool operator!() const { return !get(); } | 
| 53 |         T* operator->() const { return reinterpret_cast<T*>(m_ptrAndFlags & ~3); } | 
| 54 |  | 
| 55 |     protected: | 
| 56 |         intptr_t m_ptrAndFlags; | 
| 57 | #ifndef NDEBUG | 
| 58 |         void* m_leaksPtr; // Only used to allow tools like leaks on OSX to detect that the memory is referenced. | 
| 59 | #endif | 
| 60 |     }; | 
| 61 |  | 
| 62 |     template<class T, typename FlagEnum> class PtrAndFlags : public PtrAndFlagsBase<T, FlagEnum> { | 
| 63 |     public: | 
| 64 |         PtrAndFlags() | 
| 65 |         { | 
| 66 |             PtrAndFlagsBase<T, FlagEnum>::m_ptrAndFlags = 0; | 
| 67 |         } | 
| 68 |         PtrAndFlags(T* ptr) | 
| 69 |         { | 
| 70 |             PtrAndFlagsBase<T, FlagEnum>::m_ptrAndFlags = 0; | 
| 71 |             PtrAndFlagsBase<T, FlagEnum>::set(ptr); | 
| 72 |         } | 
| 73 |     }; | 
| 74 | } // namespace WTF | 
| 75 |  | 
| 76 | using WTF::PtrAndFlagsBase; | 
| 77 | using WTF::PtrAndFlags; | 
| 78 |  | 
| 79 | #endif // PtrAndFlags_h | 
| 80 |  |