| 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 | |