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 * 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 WTF_StdLibExtras_h 27 #define WTF_StdLibExtras_h 28 29 #include <wtf/Platform.h> 30 #include <wtf/Assertions.h> 31 32 // Use these to declare and define a static local variable (static T;) so that 33 // it is leaked so that its destructors are not called at exit. Using this 34 // macro also allows workarounds a compiler bug present in Apple's version of GCC 4.0.1. 35 #if COMPILER(GCC) && defined(__APPLE_CC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 0 && __GNUC_PATCHLEVEL__ == 1 36 #define DEFINE_STATIC_LOCAL(type, name, arguments) \ 37 static type* name##Ptr = new type arguments; \ 38 type& name = *name##Ptr 39 #else 40 #define DEFINE_STATIC_LOCAL(type, name, arguments) \ 41 static type& name = *new type arguments 42 #endif 43 44 // OBJECT_OFFSETOF: Like the C++ offsetof macro, but you can use it with classes. 45 // The magic number 0x4000 is insignificant. We use it to avoid using NULL, since 46 // NULL can cause compiler problems, especially in cases of multiple inheritance. 47 #define OBJECT_OFFSETOF(class, field) (reinterpret_cast<ptrdiff_t>(&(reinterpret_cast<class*>(0x4000)->field)) - 0x4000) 48 49 namespace WTF { 50 51 /* 52 * C++'s idea of a reinterpret_cast lacks sufficient cojones. 53 */ 54 template<typename TO, typename FROM> bitwise_cast(FROM from)55 TO bitwise_cast(FROM from) 56 { 57 COMPILE_ASSERT(sizeof(TO) == sizeof(FROM), WTF_bitwise_cast_sizeof_casted_types_is_equal); 58 union { 59 FROM from; 60 TO to; 61 } u; 62 u.from = from; 63 return u.to; 64 } 65 66 } // namespace WTF 67 68 #endif 69