From 1bf1084f2b10c3b47fd1a588d85d21ed0eb41d0c Mon Sep 17 00:00:00 2001
From: Lorry Tar Creator <lorry-tar-importer@lorry>
Date: Tue, 27 Jun 2017 06:07:23 +0000
Subject: webkitgtk-2.16.5

---
 Source/WTF/wtf/StdLibExtras.h | 286 +++++++++++++++++++++++++++---------------
 1 file changed, 188 insertions(+), 98 deletions(-)

(limited to 'Source/WTF/wtf/StdLibExtras.h')

diff --git a/Source/WTF/wtf/StdLibExtras.h b/Source/WTF/wtf/StdLibExtras.h
index 2e35031da..716661fad 100644
--- a/Source/WTF/wtf/StdLibExtras.h
+++ b/Source/WTF/wtf/StdLibExtras.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ * Copyright (C) 2008, 2016 Apple Inc. All Rights Reserved.
  * Copyright (C) 2013 Patrick Gansterer <paroga@paroga.com>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -28,35 +28,33 @@
 #define WTF_StdLibExtras_h
 
 #include <chrono>
+#include <cstring>
 #include <memory>
 #include <wtf/Assertions.h>
 #include <wtf/CheckedArithmetic.h>
+#include <wtf/Compiler.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) \
+// This was used to declare and define a static local variable (static T;) so that
+//  it was leaked so that its destructors were not called at exit.
+// Newly written code should use static NeverDestroyed<T> instead.
+#ifndef DEPRECATED_DEFINE_STATIC_LOCAL
+#define DEPRECATED_DEFINE_STATIC_LOCAL(type, name, arguments) \
     static type& name = *new type arguments
 #endif
-#endif
 
 // Use this macro to declare and define a debug-only global variable that may have a
 // non-trivial constructor and destructor. When building with clang, this will suppress
 // warnings about global constructors and exit-time destructors.
-#ifndef NDEBUG
-#if COMPILER(CLANG)
-#define DEFINE_DEBUG_ONLY_GLOBAL(type, name, arguments) \
+#define DEFINE_GLOBAL_FOR_LOGGING(type, name, arguments) \
     _Pragma("clang diagnostic push") \
     _Pragma("clang diagnostic ignored \"-Wglobal-constructors\"") \
     _Pragma("clang diagnostic ignored \"-Wexit-time-destructors\"") \
     static type name arguments; \
     _Pragma("clang diagnostic pop")
+
+#ifndef NDEBUG
+#if COMPILER(CLANG)
+#define DEFINE_DEBUG_ONLY_GLOBAL(type, name, arguments) DEFINE_GLOBAL_FOR_LOGGING(type, name, arguments)
 #else
 #define DEFINE_DEBUG_ONLY_GLOBAL(type, name, arguments) \
     static type name arguments;
@@ -70,10 +68,17 @@
 // 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)
 
+#define CAST_OFFSET(from, to) (reinterpret_cast<uintptr_t>(static_cast<to>((reinterpret_cast<from>(0x4000)))) - 0x4000)
+
 // STRINGIZE: Can convert any value to quoted string, even expandable macros
 #define STRINGIZE(exp) #exp
 #define STRINGIZE_VALUE_OF(exp) STRINGIZE(exp)
 
+// WTF_CONCAT: concatenate two symbols into one, even expandable macros
+#define WTF_CONCAT_INTERNAL_DONT_USE(a, b) a ## b
+#define WTF_CONCAT(a, b) WTF_CONCAT_INTERNAL_DONT_USE(a, b)
+
+
 /*
  * The reinterpret_cast<Type1*>([pointer to Type2]) expressions - where
  * sizeof(Type1) > sizeof(Type2) - cause the following warning on ARM with GCC:
@@ -84,7 +89,7 @@
  * - 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)
+#if (CPU(ARM) || CPU(MIPS)) && COMPILER(GCC_OR_CLANG)
 template<typename Type>
 inline bool isPointerTypeAlignmentOkay(Type* ptr)
 {
@@ -115,8 +120,11 @@ inline bool isPointerTypeAlignmentOkay(Type*)
 
 namespace WTF {
 
+enum CheckMoveParameterTag { CheckMoveParameter };
+
 static const size_t KB = 1024;
 static const size_t MB = 1024 * 1024;
+static const size_t GB = 1024 * 1024 * 1024;
 
 inline bool isPointerAligned(void* p)
 {
@@ -135,18 +143,20 @@ template<typename ToType, typename FromType>
 inline ToType bitwise_cast(FromType from)
 {
     static_assert(sizeof(FromType) == sizeof(ToType), "bitwise_cast size of FromType and ToType must be equal!");
-    union {
-        FromType from;
-        ToType to;
-    } u;
-    u.from = from;
-    return u.to;
+#if COMPILER_SUPPORTS(BUILTIN_IS_TRIVIALLY_COPYABLE)
+    // Not all recent STL implementations support the std::is_trivially_copyable type trait. Work around this by only checking on toolchains which have the equivalent compiler intrinsic.
+    static_assert(__is_trivially_copyable(ToType), "bitwise_cast of non-trivially-copyable type!");
+    static_assert(__is_trivially_copyable(FromType), "bitwise_cast of non-trivially-copyable type!");
+#endif
+    typename std::remove_const<ToType>::type to { };
+    std::memcpy(&to, &from, sizeof(to));
+    return to;
 }
 
 template<typename ToType, typename FromType>
 inline ToType safeCast(FromType value)
 {
-    ASSERT(isInBounds<ToType>(value));
+    RELEASE_ASSERT(isInBounds<ToType>(value));
     return static_cast<ToType>(value);
 }
 
@@ -166,23 +176,32 @@ inline size_t bitCount(uint64_t bits)
 // 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];
 // GCC needs some help to deduce a 0 length array.
-#if COMPILER(GCC)
+#if COMPILER(GCC_OR_CLANG)
 template<typename T> char (&ArrayLengthHelperFunction(T (&)[0]))[0];
 #endif
 #define WTF_ARRAY_LENGTH(array) sizeof(::WTF::ArrayLengthHelperFunction(array))
 
+ALWAYS_INLINE constexpr size_t roundUpToMultipleOfImpl0(size_t remainderMask, size_t x)
+{
+    return (x + remainderMask) & ~remainderMask;
+}
+
+ALWAYS_INLINE constexpr size_t roundUpToMultipleOfImpl(size_t divisor, size_t x)
+{
+    return roundUpToMultipleOfImpl0(divisor - 1, x);
+}
+
 // Efficient implementation that takes advantage of powers of two.
 inline size_t roundUpToMultipleOf(size_t divisor, size_t x)
 {
     ASSERT(divisor && !(divisor & (divisor - 1)));
-    size_t remainderMask = divisor - 1;
-    return (x + remainderMask) & ~remainderMask;
+    return roundUpToMultipleOfImpl(divisor, x);
 }
 
-template<size_t divisor> inline size_t roundUpToMultipleOf(size_t x)
+template<size_t divisor> inline constexpr size_t roundUpToMultipleOf(size_t x)
 {
     static_assert(divisor && !(divisor & (divisor - 1)), "divisor must be a power of two!");
-    return roundUpToMultipleOf(divisor, x);
+    return roundUpToMultipleOfImpl(divisor, x);
 }
 
 enum BinarySearchMode {
@@ -276,32 +295,120 @@ inline void insertIntoBoundedVector(VectorType& vector, size_t size, const Eleme
     vector[index] = element;
 }
 
-} // namespace WTF
+// This is here instead of CompilationThread.h to prevent that header from being included
+// everywhere. The fact that this method, and that header, exist outside of JSC is a bug.
+// https://bugs.webkit.org/show_bug.cgi?id=131815
+WTF_EXPORT_PRIVATE bool isCompilationThread();
+
+template<typename Func>
+bool isStatelessLambda()
+{
+    return std::is_empty<Func>::value;
+}
 
-#if OS(WINCE)
-// Windows CE CRT has does not implement bsearch().
-inline void* wtf_bsearch(const void* key, const void* base, size_t count, size_t size, int (*compare)(const void *, const void *))
-{
-    const char* first = static_cast<const char*>(base);
-
-    while (count) {
-        size_t pos = (count - 1) >> 1;
-        const char* item = first + pos * size;
-        int compareResult = compare(item, key);
-        if (!compareResult)
-            return const_cast<char*>(item);
-        if (compareResult < 0) {
-            count -= (pos + 1);
-            first += (pos + 1) * size;
-        } else
-            count = pos;
+template<typename ResultType, typename Func, typename... ArgumentTypes>
+ResultType callStatelessLambda(ArgumentTypes&&... arguments)
+{
+    uint64_t data[(sizeof(Func) + sizeof(uint64_t) - 1) / sizeof(uint64_t)];
+    memset(data, 0, sizeof(data));
+    return (*bitwise_cast<Func*>(data))(std::forward<ArgumentTypes>(arguments)...);
+}
+
+template<typename T, typename U>
+bool checkAndSet(T& left, U right)
+{
+    if (left == right)
+        return false;
+    left = right;
+    return true;
+}
+
+template<typename T>
+bool findBitInWord(T word, size_t& index, size_t endIndex, bool value)
+{
+    static_assert(std::is_unsigned<T>::value, "Type used in findBitInWord must be unsigned");
+    
+    word >>= index;
+    
+    while (index < endIndex) {
+        if ((word & 1) == static_cast<T>(value))
+            return true;
+        index++;
+        word >>= 1;
+    }
+    
+    index = endIndex;
+    return false;
+}
+
+// Visitor adapted from http://stackoverflow.com/questions/25338795/is-there-a-name-for-this-tuple-creation-idiom
+
+template <class A, class... B>
+struct Visitor : Visitor<A>, Visitor<B...> {
+    Visitor(A a, B... b)
+        : Visitor<A>(a)
+        , Visitor<B...>(b...)
+    {
+    }
+
+    using Visitor<A>::operator ();
+    using Visitor<B...>::operator ();
+};
+  
+template <class A>
+struct Visitor<A> : A {
+    Visitor(A a)
+        : A(a)
+    {
     }
 
-    return 0;
+    using A::operator();
+};
+ 
+template <class... F>
+Visitor<F...> makeVisitor(F... f)
+{
+    return Visitor<F...>(f...);
 }
 
-#define bsearch(key, base, count, size, compare) wtf_bsearch(key, base, count, size, compare)
-#endif
+namespace Detail
+{
+    template <typename, template <typename...> class>
+    struct IsTemplate_ : std::false_type
+    {
+    };
+
+    template <typename... Ts, template <typename...> class C>
+    struct IsTemplate_<C<Ts...>, C> : std::true_type
+    {
+    };
+}
+
+template <typename T, template <typename...> class Template>
+struct IsTemplate : public std::integral_constant<bool, Detail::IsTemplate_<T, Template>::value> {};
+
+namespace Detail
+{
+    template <template <typename...> class Base, typename Derived>
+    struct IsBaseOfTemplateImpl
+    {
+        template <typename... Args>
+        static std::true_type test(Base<Args...>*);
+        static std::false_type test(void*);
+
+        static constexpr const bool value = decltype(test(std::declval<typename std::remove_cv<Derived>::type*>()))::value;
+    };
+}
+
+template <template <typename...> class Base, typename Derived>
+struct IsBaseOfTemplate : public std::integral_constant<bool, Detail::IsBaseOfTemplateImpl<Base, Derived>::value> {};
+
+template <class T>
+struct RemoveCVAndReference  {
+    typedef typename std::remove_cv<typename std::remove_reference<T>::type>::type type;
+};
+
+} // namespace WTF
 
 // This version of placement new omits a 0 check.
 enum NotNullTag { NotNull };
@@ -311,20 +418,9 @@ inline void* operator new(size_t, NotNullTag, void* location)
     return location;
 }
 
-#if (COMPILER(GCC) && !COMPILER(CLANG) && !GCC_VERSION_AT_LEAST(4, 8, 1))
-
-// Work-around for Pre-C++11 syntax in MSVC 2010, and prior as well as GCC < 4.8.1.
-namespace std {
-    template<class T> struct is_trivially_destructible {
-        static const bool value = std::has_trivial_destructor<T>::value;
-    };
-}
-#endif
-
 // This adds various C++14 features for versions of the STL that may not yet have them.
 namespace std {
-// MSVC 2013 supports std::make_unique already.
-#if !defined(_MSC_VER) || _MSC_VER < 1800
+#if COMPILER(CLANG) && __cplusplus < 201400L
 template<class T> struct _Unique_if {
     typedef unique_ptr<T> _Single_object;
 };
@@ -352,58 +448,52 @@ make_unique(size_t n)
 
 template<class T, class... Args> typename _Unique_if<T>::_Known_bound
 make_unique(Args&&...) = delete;
-#endif
 
-// Compile-time integer sequences
-// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3658.html
-// (Note that we only implement index_sequence, and not the more generic integer_sequence).
-template<size_t... indexes> struct index_sequence {
-    static size_t size() { return sizeof...(indexes); }
-};
+// std::exchange
+template<class T, class U = T>
+T exchange(T& t, U&& newValue)
+{
+    T oldValue = std::move(t);
+    t = std::forward<U>(newValue);
 
-template<size_t currentIndex, size_t...indexes> struct make_index_sequence_helper;
+    return oldValue;
+}
+#endif
 
-template<size_t...indexes> struct make_index_sequence_helper<0, indexes...> {
-    typedef std::index_sequence<indexes...> type;
-};
+template<WTF::CheckMoveParameterTag, typename T>
+ALWAYS_INLINE constexpr typename remove_reference<T>::type&& move(T&& value)
+{
+    static_assert(is_lvalue_reference<T>::value, "T is not an lvalue reference; move() is unnecessary.");
 
-template<size_t currentIndex, size_t...indexes> struct make_index_sequence_helper {
-    typedef typename make_index_sequence_helper<currentIndex - 1, currentIndex - 1, indexes...>::type type;
-};
+    using NonRefQualifiedType = typename remove_reference<T>::type;
+    static_assert(!is_const<NonRefQualifiedType>::value, "T is const qualified.");
 
-template<size_t length> struct make_index_sequence : public make_index_sequence_helper<length>::type { };
+    return move(forward<T>(value));
+}
 
-#if COMPILER_SUPPORTS(CXX_USER_LITERALS)
-// These literals are available in C++14, so once we require C++14 compilers we can get rid of them here.
-// (User-literals need to have a leading underscore so we add it here - the "real" literals don't have underscores).
-namespace literals {
-namespace chrono_literals {
-    CONSTEXPR inline chrono::seconds operator"" _s(unsigned long long s)
-    {
-        return chrono::seconds(static_cast<chrono::seconds::rep>(s));
-    }
+} // namespace std
 
-    CONSTEXPR chrono::milliseconds operator"" _ms(unsigned long long ms)
-    {
-        return chrono::milliseconds(static_cast<chrono::milliseconds::rep>(ms));
-    }
-}
-}
-#endif
-}
+#define WTFMove(value) std::move<WTF::CheckMoveParameter>(value)
 
 using WTF::KB;
 using WTF::MB;
+using WTF::GB;
+using WTF::approximateBinarySearch;
+using WTF::binarySearch;
+using WTF::bitwise_cast;
+using WTF::callStatelessLambda;
+using WTF::checkAndSet;
+using WTF::findBitInWord;
 using WTF::insertIntoBoundedVector;
+using WTF::isCompilationThread;
 using WTF::isPointerAligned;
+using WTF::isStatelessLambda;
 using WTF::is8ByteAligned;
-using WTF::binarySearch;
-using WTF::tryBinarySearch;
-using WTF::approximateBinarySearch;
-using WTF::bitwise_cast;
+using WTF::roundUpToMultipleOf;
 using WTF::safeCast;
+using WTF::tryBinarySearch;
 
-#if COMPILER_SUPPORTS(CXX_USER_LITERALS)
+#if !COMPILER(CLANG) || __cplusplus >= 201400L
 // We normally don't want to bring in entire std namespaces, but literals are an exception.
 using namespace std::literals::chrono_literals;
 #endif
-- 
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