[libcxx] Emulation of atomic builtins for MSVC

[K-ballo]

Summary

MSVC does not implement the GCC atomic builtins. This patch emulates those needed by libc++ by forwarding to MS's interlocked intrinsic functions.

[K-ballo]

Use _LIBCPP_ALWAYS_INLINE as it seems a better choice.

[K-ballo]

Waiting for VS2015RTM

include/__refstring

 #define _LIBCPP___REFSTRING
 
 #include <__config>
 #include <cstddef>
 #include <cstring>
 #if __APPLE__
 #include <dlfcn.h>
 #include <mach-o/dyld.h>
+#elif defined(_LIBCPP_MSVC)
+#include <support/win32/sync_win32.h>
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_HIDDEN __libcpp_refstring
 {
 private:
     const char* str_;

include/support/win32/sync_win32.h

+// -*- C++ -*-
+//===--------------------- support/win32/sync_win32.h ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_SUPPORT_WIN32_SYNC_WIN32_H
+#define _LIBCPP_SUPPORT_WIN32_SYNC_WIN32_H
+
+#if !defined(_LIBCPP_MSVC)
+#error "This header complements Microsoft's Visual C++, and should not be included otherwise."
+#else
+
+#include <intrin.h>
+
+template <bool, class _Tp> struct __sync_win32_enable_if {};
+template <class _Tp> struct __sync_win32_enable_if<true, _Tp> {typedef _Tp type;};
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE _Tp __sync_add_and_fetch(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(long), _Tp>::type __val)
+{
+    return (_Tp)(_InterlockedExchangeAdd((long*)(__ptr), (long)(__val))) + __val;
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE _Tp __sync_add_and_fetch(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(__int64), _Tp>::type __val)
+{
+    return (_Tp)(_InterlockedExchangeAdd64((__int64*)(__ptr), (__int64)(__val))) + __val;
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE _Tp __sync_fetch_and_add(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(long), _Tp>::type __val)
+{
+    return (_Tp)(_InterlockedExchangeAdd((long*)(__ptr), (long)(__val)));
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE _Tp __sync_fetch_and_add(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(__int64), _Tp>::type __val)
+{
+    return (_Tp)(_InterlockedExchangeAdd64((__int64*)(__ptr), (__int64)(__val)));
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE _Tp __sync_lock_test_and_set(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(long), _Tp>::type __val)
+{
+    return (_Tp)(_InterlockedExchange((long*)(__ptr), (long)(__val)));
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE _Tp __sync_lock_test_and_set(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(__int64), _Tp>::type __val)
+{
+    return (_Tp)(_InterlockedExchange64((__int64*)(__ptr), (__int64)(__val)));
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE bool __sync_bool_compare_and_swap(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(long), _Tp>::type __old_val,
+    typename __sync_win32_enable_if<true, _Tp>::type __new_val)
+{
+    return _InterlockedCompareExchange((long*)(__ptr), (long)(__new_val),
+                                       (long)(__old_val)) == (long)(__old_val);
+}
+
+template <class _Tp>
+_LIBCPP_ALWAYS_INLINE bool __sync_bool_compare_and_swap(
+    _Tp *__ptr,
+    typename __sync_win32_enable_if<sizeof(_Tp) == sizeof(__int64), _Tp>::type __old_val,
+    typename __sync_win32_enable_if<true, _Tp>::type __new_val)
+{
+    return _InterlockedCompareExchange64((__int64*)(__ptr), (__int64)(__new_val),
+                                         (__int64)(__old_val)) == (__int64)(__old_val);
+}
+
+#endif // _LIBCPP_MSVCRT
+
+#endif // _LIBCPP_SUPPORT_WIN32_SYNC_WIN32_H

src/exception.cpp

 //===------------------------ exception.cpp -------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 #include <stdlib.h>
 #include <stdio.h>
 
 #include "exception"
 #include "new"
+#if defined(_LIBCPP_MSVC)
+#include <support/win32/sync_win32.h>
+#endif
 
 #ifndef __has_include
 #define __has_include(inc) 0
 #endif
 
 #ifdef __APPLE__
   #include <cxxabi.h>
 

src/locale.cpp

 #include "typeinfo"
 #ifndef _LIBCPP_NO_EXCEPTIONS
 #  include "type_traits"
 #endif
 #include "clocale"
 #include "cstring"
 #include "cwctype"
 #include "__sso_allocator"
+#if defined(_LIBCPP_MSVC)
+#include <support/win32/sync_win32.h>
+#endif
 #if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
 #include <support/win32/locale_win32.h>
 #elif !defined(__ANDROID__)
 #include <langinfo.h>
 #endif
 #include <stdlib.h>
 #include <stdio.h>
 

src/memory.cpp

 //===------------------------ memory.cpp ----------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #define _LIBCPP_BUILDING_MEMORY
 #include "memory"
 #include "mutex"
 #include "thread"
+#if defined(_LIBCPP_MSVC)
+#include <support/win32/sync_win32.h>
+#endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace
 {
 
 template <class T>
 inline T

src/new.cpp

 //===--------------------------- new.cpp ----------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is dual licensed under the MIT and the University of Illinois Open
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #define _LIBCPP_BUILDING_NEW
 
 #include <stdlib.h>
 
 #include "new"
+#if defined(_LIBCPP_MSVC)
+#include <support/win32/sync_win32.h>
+#endif
 
 #ifndef __has_include
 #define __has_include(inc) 0
 #endif
 
 #ifdef __APPLE__
     #include <cxxabi.h>