+++ /dev/null
-/*
- * Copyright (C) 2008 Apple Inc. All Rights Reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef WTF_StdLibExtras_h
-#define WTF_StdLibExtras_h
-
-#include <wtf/Assertions.h>
-
-// Use these to declare and define a static local variable (static T;) so that
-// it is leaked so that its destructors are not called at exit. Using this
-// macro also allows workarounds a compiler bug present in Apple's version of GCC 4.0.1.
-#ifndef DEFINE_STATIC_LOCAL
-#if COMPILER(GCC) && defined(__APPLE_CC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 0 && __GNUC_PATCHLEVEL__ == 1
-#define DEFINE_STATIC_LOCAL(type, name, arguments) \
- static type* name##Ptr = new type arguments; \
- type& name = *name##Ptr
-#else
-#define DEFINE_STATIC_LOCAL(type, name, arguments) \
- static type& name = *new type arguments
-#endif
-#endif
-
-// OBJECT_OFFSETOF: Like the C++ offsetof macro, but you can use it with classes.
-// The magic number 0x4000 is insignificant. We use it to avoid using NULL, since
-// NULL can cause compiler problems, especially in cases of multiple inheritance.
-#define OBJECT_OFFSETOF(class, field) (reinterpret_cast<ptrdiff_t>(&(reinterpret_cast<class*>(0x4000)->field)) - 0x4000)
-
-// STRINGIZE: Can convert any value to quoted string, even expandable macros
-#define STRINGIZE(exp) #exp
-#define STRINGIZE_VALUE_OF(exp) STRINGIZE(exp)
-
-/*
- * The reinterpret_cast<Type1*>([pointer to Type2]) expressions - where
- * sizeof(Type1) > sizeof(Type2) - cause the following warning on ARM with GCC:
- * increases required alignment of target type.
- *
- * An implicit or an extra static_cast<void*> bypasses the warning.
- * For more info see the following bugzilla entries:
- * - https://bugs.webkit.org/show_bug.cgi?id=38045
- * - http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43976
- */
-#if (CPU(ARM) || CPU(MIPS)) && COMPILER(GCC)
-template<typename Type>
-bool isPointerTypeAlignmentOkay(Type* ptr)
-{
- return !(reinterpret_cast<intptr_t>(ptr) % __alignof__(Type));
-}
-
-template<typename TypePtr>
-TypePtr reinterpret_cast_ptr(void* ptr)
-{
- ASSERT(isPointerTypeAlignmentOkay(reinterpret_cast<TypePtr>(ptr)));
- return reinterpret_cast<TypePtr>(ptr);
-}
-
-template<typename TypePtr>
-TypePtr reinterpret_cast_ptr(const void* ptr)
-{
- ASSERT(isPointerTypeAlignmentOkay(reinterpret_cast<TypePtr>(ptr)));
- return reinterpret_cast<TypePtr>(ptr);
-}
-#else
-#define reinterpret_cast_ptr reinterpret_cast
-#endif
-
-namespace WTF {
-
-/*
- * C++'s idea of a reinterpret_cast lacks sufficient cojones.
- */
-template<typename TO, typename FROM>
-inline TO bitwise_cast(FROM from)
-{
- COMPILE_ASSERT(sizeof(TO) == sizeof(FROM), WTF_bitwise_cast_sizeof_casted_types_is_equal);
- union {
- FROM from;
- TO to;
- } u;
- u.from = from;
- return u.to;
-}
-
-// Returns a count of the number of bits set in 'bits'.
-inline size_t bitCount(unsigned bits)
-{
- bits = bits - ((bits >> 1) & 0x55555555);
- bits = (bits & 0x33333333) + ((bits >> 2) & 0x33333333);
- return (((bits + (bits >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
-}
-
-// Macro that returns a compile time constant with the length of an array, but gives an error if passed a non-array.
-template<typename T, size_t Size> char (&ArrayLengthHelperFunction(T (&)[Size]))[Size];
-#define WTF_ARRAY_LENGTH(array) sizeof(::WTF::ArrayLengthHelperFunction(array))
-
-// Efficient implementation that takes advantage of powers of two.
-template<size_t divisor> inline size_t roundUpToMultipleOf(size_t x)
-{
- COMPILE_ASSERT(divisor && !(divisor & (divisor - 1)), divisor_is_a_power_of_two);
-
- size_t remainderMask = divisor - 1;
- return (x + remainderMask) & ~remainderMask;
-}
-
-// Binary search algorithm, calls extractKey on pre-sorted elements in array,
-// compares result with key (KeyTypes should be comparable with '--', '<', '>').
-// Optimized for cases where the array contains the key, checked by assertions.
-template<typename ArrayType, typename KeyType, KeyType(*extractKey)(ArrayType*)>
-inline ArrayType* binarySearch(ArrayType* array, size_t size, KeyType key)
-{
- // The array must contain at least one element (pre-condition, array does conatin key).
- // If the array only contains one element, no need to do the comparison.
- while (size > 1) {
- // Pick an element to check, half way through the array, and read the value.
- int pos = (size - 1) >> 1;
- KeyType val = extractKey(&array[pos]);
-
- // If the key matches, success!
- if (val == key)
- return &array[pos];
- // The item we are looking for is smaller than the item being check; reduce the value of 'size',
- // chopping off the right hand half of the array.
- else if (key < val)
- size = pos;
- // Discard all values in the left hand half of the array, up to and including the item at pos.
- else {
- size -= (pos + 1);
- array += (pos + 1);
- }
-
- // 'size' should never reach zero.
- ASSERT(size);
- }
-
- // If we reach this point we've chopped down to one element, no need to check it matches
- ASSERT(size == 1);
- ASSERT(key == extractKey(&array[0]));
- return &array[0];
-}
-
-} // namespace WTF
-
-using WTF::binarySearch;
-using WTF::bitwise_cast;
-
-#endif // WTF_StdLibExtras_h
projects / apple / javascriptcore.git / blobdiff