| 1 | /*
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| 2 | * Copyright (C) 2008 Apple Inc. All Rights Reserved.
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| 3 | *
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| 4 | * Redistribution and use in source and binary forms, with or without
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| 5 | * modification, are permitted provided that the following conditions
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| 6 | * are met:
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| 7 | * 1. Redistributions of source code must retain the above copyright
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| 8 | * notice, this list of conditions and the following disclaimer.
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| 9 | * 2. Redistributions in binary form must reproduce the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer in the
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| 11 | * documentation and/or other materials provided with the distribution.
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| 12 | *
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| 13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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| 14 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 15 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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| 16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
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| 17 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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| 18 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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| 19 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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| 20 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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| 21 | * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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| 23 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 24 | */
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| 25 |
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| 26 | #ifndef WTF_StdLibExtras_h
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| 27 | #define WTF_StdLibExtras_h
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| 28 |
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| 29 | #include <wtf/Platform.h>
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| 30 | #include <wtf/Assertions.h>
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| 31 |
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| 32 | // Use these to declare and define a static local variable (static T;) so that
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| 33 | // it is leaked so that its destructors are not called at exit. Using this
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| 34 | // macro also allows workarounds a compiler bug present in Apple's version of GCC 4.0.1.
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| 35 | #if COMPILER(GCC) && defined(__APPLE_CC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 0 && __GNUC_PATCHLEVEL__ == 1
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| 36 | #define DEFINE_STATIC_LOCAL(type, name, arguments) \
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| 37 | static type* name##Ptr = new type arguments; \
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| 38 | type& name = *name##Ptr
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| 39 | #else
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| 40 | #define DEFINE_STATIC_LOCAL(type, name, arguments) \
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| 41 | static type& name = *new type arguments
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| 42 | #endif
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| 43 |
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| 44 | // OBJECT_OFFSETOF: Like the C++ offsetof macro, but you can use it with classes.
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| 45 | // The magic number 0x4000 is insignificant. We use it to avoid using NULL, since
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| 46 | // NULL can cause compiler problems, especially in cases of multiple inheritance.
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| 47 | #define OBJECT_OFFSETOF(class, field) (reinterpret_cast<ptrdiff_t>(&(reinterpret_cast<class*>(0x4000)->field)) - 0x4000)
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| 48 |
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| 49 | namespace WTF {
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| 50 |
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| 51 | /*
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| 52 | * C++'s idea of a reinterpret_cast lacks sufficient cojones.
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| 53 | */
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| 54 | template<typename TO, typename FROM>
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| 55 | TO bitwise_cast(FROM from)
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| 56 | {
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| 57 | COMPILE_ASSERT(sizeof(TO) == sizeof(FROM), WTF_bitwise_cast_sizeof_casted_types_is_equal);
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| 58 | union {
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| 59 | FROM from;
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| 60 | TO to;
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| 61 | } u;
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| 62 | u.from = from;
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| 63 | return u.to;
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| 64 | }
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| 65 |
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| 66 | } // namespace WTF
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| 67 |
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| 68 | #endif
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