Index: libcxx/src/filesystem/filesystem_common.h
===================================================================
--- libcxx/src/filesystem/filesystem_common.h
+++ libcxx/src/filesystem/filesystem_common.h
@@ -340,6 +340,8 @@
 #define S_ISLNK(m)      (((m) & _S_IFMT) == _S_IFLNK)
 #define S_ISSOCK(m)     (((m) & _S_IFMT) == _S_IFSOCK)
 
+#define O_NONBLOCK 0
+
 #else
 using TimeSpec = timespec;
 using StatT = struct stat;
Index: libcxx/src/filesystem/operations.cpp
===================================================================
--- libcxx/src/filesystem/operations.cpp
+++ libcxx/src/filesystem/operations.cpp
@@ -431,10 +431,102 @@
   return stat_handle(h, buf);
 }
 
+int mkdir(const wchar_t *path, int permissions) {
+  (void)permissions;
+  return _wmkdir(path);
+}
+
+int symlink_file_dir(const wchar_t *oldname, const wchar_t *newname,
+                     bool is_dir) {
+  DWORD flags = is_dir ? SYMBOLIC_LINK_FLAG_DIRECTORY : 0;
+  if (CreateSymbolicLinkW(newname, oldname,
+                          flags | SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE))
+    return 0;
+  if (GetLastError() != ERROR_INVALID_PARAMETER)
+    return set_errno();
+  if (CreateSymbolicLinkW(newname, oldname, flags))
+    return 0;
+  return set_errno();
+}
+
+int symlink_file(const wchar_t *oldname, const wchar_t *newname) {
+  return symlink_file_dir(oldname, newname, false);
+}
+
+int symlink_dir(const wchar_t *oldname, const wchar_t *newname) {
+  return symlink_file_dir(oldname, newname, true);
+}
+
+int link(const wchar_t *oldname, const wchar_t *newname) {
+  if (CreateHardLinkW(newname, oldname, nullptr))
+    return 0;
+  return set_errno();
+}
+
+int remove(const wchar_t *path) {
+  detail::WinHandle h(path, DELETE, FILE_FLAG_OPEN_REPARSE_POINT);
+  if (!h)
+    return set_errno();
+  FILE_DISPOSITION_INFO info;
+  info.DeleteFile = TRUE;
+  if (!SetFileInformationByHandle(h, FileDispositionInfo, &info, sizeof(info)))
+    return set_errno();
+  return 0;
+}
+
+int truncate_handle(HANDLE h, off_t length) {
+  LARGE_INTEGER size_param;
+  size_param.QuadPart = length;
+  if (!SetFilePointerEx(h, size_param, 0, FILE_BEGIN))
+    return set_errno();
+  if (!SetEndOfFile(h))
+    return set_errno();
+  return 0;
+}
+
+int ftruncate(int fd, off_t length) {
+  HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
+  return truncate_handle(h, length);
+}
+
+int truncate(const wchar_t *path, off_t length) {
+  detail::WinHandle h(path, GENERIC_WRITE, 0);
+  if (!h)
+    return set_errno();
+  return truncate_handle(h, length);
+}
+
+int rename(const wchar_t *from, const wchar_t *to) {
+  if (!(MoveFileExW(from, to,
+                    MOVEFILE_COPY_ALLOWED | MOVEFILE_REPLACE_EXISTING)))
+    return set_errno();
+  return 0;
+}
+
+template <class... Args> int open(const wchar_t *filename, Args... args) {
+  return _wopen(filename, args...);
+}
+int close(int fd) { return _close(fd); }
+int chdir(const wchar_t *path) { return _wchdir(path); }
 #else
+int symlink_file(const char *oldname, const char *newname) {
+  return ::symlink(oldname, newname);
+}
+int symlink_dir(const char *oldname, const char *newname) {
+  return ::symlink(oldname, newname);
+}
+using ::chdir;
+using ::close;
 using ::fstat;
+using ::ftruncate;
+using ::link;
 using ::lstat;
+using ::mkdir;
+using ::open;
+using ::remove;
+using ::rename;
 using ::stat;
+using ::truncate;
 #endif
 
 
@@ -448,7 +540,7 @@
   static FileDescriptor create(const path* p, error_code& ec, Args... args) {
     ec.clear();
     int fd;
-    if ((fd = ::open(p->c_str(), args...)) == -1) {
+    if ((fd = detail::open(p->c_str(), args...)) == -1) {
       ec = capture_errno();
       return FileDescriptor{p};
     }
@@ -474,7 +566,7 @@
 
   void close() noexcept {
     if (fd != -1)
-      ::close(fd);
+      detail::close(fd);
     fd = -1;
   }
 
@@ -564,7 +656,7 @@
 
 // http://pubs.opengroup.org/onlinepubs/9699919799/functions/ftruncate.html
 bool posix_ftruncate(const FileDescriptor& fd, off_t to_size, error_code& ec) {
-  if (::ftruncate(fd.fd, to_size) == -1) {
+  if (detail::ftruncate(fd.fd, to_size) == -1) {
     ec = capture_errno();
     return true;
   }
@@ -992,7 +1084,7 @@
 bool __create_directory(const path& p, error_code* ec) {
   ErrorHandler<bool> err("create_directory", ec, &p);
 
-  if (::mkdir(p.c_str(), static_cast<int>(perms::all)) == 0)
+  if (detail::mkdir(p.c_str(), static_cast<int>(perms::all)) == 0)
     return true;
   if (errno != EEXIST)
     err.report(capture_errno());
@@ -1011,7 +1103,7 @@
     return err.report(errc::not_a_directory,
                       "the specified attribute path is invalid");
 
-  if (::mkdir(p.c_str(), attr_stat.st_mode) == 0)
+  if (detail::mkdir(p.c_str(), attr_stat.st_mode) == 0)
     return true;
   if (errno != EEXIST)
     err.report(capture_errno());
@@ -1021,19 +1113,19 @@
 void __create_directory_symlink(path const& from, path const& to,
                                 error_code* ec) {
   ErrorHandler<void> err("create_directory_symlink", ec, &from, &to);
-  if (::symlink(from.c_str(), to.c_str()) != 0)
+  if (detail::symlink_dir(from.c_str(), to.c_str()) == -1)
     return err.report(capture_errno());
 }
 
 void __create_hard_link(const path& from, const path& to, error_code* ec) {
   ErrorHandler<void> err("create_hard_link", ec, &from, &to);
-  if (::link(from.c_str(), to.c_str()) == -1)
+  if (detail::link(from.c_str(), to.c_str()) == -1)
     return err.report(capture_errno());
 }
 
 void __create_symlink(path const& from, path const& to, error_code* ec) {
   ErrorHandler<void> err("create_symlink", ec, &from, &to);
-  if (::symlink(from.c_str(), to.c_str()) == -1)
+  if (detail::symlink_file(from.c_str(), to.c_str()) == -1)
     return err.report(capture_errno());
 }
 
@@ -1053,7 +1145,7 @@
 
 void __current_path(const path& p, error_code* ec) {
   ErrorHandler<void> err("current_path", ec, &p);
-  if (::chdir(p.c_str()) == -1)
+  if (detail::chdir(p.c_str()) == -1)
     err.report(capture_errno());
 }
 
@@ -1258,7 +1350,7 @@
 
 bool __remove(const path& p, error_code* ec) {
   ErrorHandler<bool> err("remove", ec, &p);
-  if (::remove(p.c_str()) == -1) {
+  if (detail::remove(p.c_str()) == -1) {
     if (errno != ENOENT)
       err.report(capture_errno());
     return false;
@@ -1307,13 +1399,13 @@
 
 void __rename(const path& from, const path& to, error_code* ec) {
   ErrorHandler<void> err("rename", ec, &from, &to);
-  if (::rename(from.c_str(), to.c_str()) == -1)
+  if (detail::rename(from.c_str(), to.c_str()) == -1)
     err.report(capture_errno());
 }
 
 void __resize_file(const path& p, uintmax_t size, error_code* ec) {
   ErrorHandler<void> err("resize_file", ec, &p);
-  if (::truncate(p.c_str(), static_cast< ::off_t>(size)) == -1)
+  if (detail::truncate(p.c_str(), static_cast< ::off_t>(size)) == -1)
     return err.report(capture_errno());
 }