[libcxx] r337960 - [libc++] Use __int128_t to represent file_time_type.

Alex L via cfe-commits cfe-commits at lists.llvm.org
Wed Jul 25 14:22:08 PDT 2018


On 25 July 2018 at 13:51, Eric Fiselier via cfe-commits <
cfe-commits at lists.llvm.org> wrote:

> Author: ericwf
> Date: Wed Jul 25 13:51:49 2018
> New Revision: 337960
>
> URL: http://llvm.org/viewvc/llvm-project?rev=337960&view=rev
> Log:
> [libc++] Use __int128_t to represent file_time_type.
>
> Summary:
> The ``file_time_type`` time point is used to represent the write times for
> files.
> Its job is to act as part of a C++ wrapper for less ideal system
> interfaces. The
> underlying filesystem uses the ``timespec`` struct for the same purpose.
>
> However, the initial implementation of ``file_time_type`` could not
> represent
> either the range or resolution of ``timespec``, making it unsuitable.
> Fixing
> this requires an implementation which uses more than 64 bits to store the
> time point.
>
> I primarily considered two solutions: Using ``__int128_t`` and using a
> arithmetic emulation of ``timespec``. Each has its pros and cons, and both
> come with more than one complication.
>
> However, after a lot of consideration, I decided on using `__int128_t`.
> This patch implements that change.
>
> Please see the [FileTimeType Design Document](http://libcxx.llvm.
> org/docs/DesignDocs/FileTimeType.html) for more information.
>
> Reviewers: mclow.lists, ldionne, joerg, arthur.j.odwyer, EricWF
>
> Reviewed By: EricWF
>
> Subscribers: christof, K-ballo, cfe-commits, BillyONeal
>
> Differential Revision: https://reviews.llvm.org/D49774
>
> Added:
>     libcxx/trunk/src/include/apple_availability.h
> Modified:
>     libcxx/trunk/include/experimental/filesystem
>     libcxx/trunk/src/chrono.cpp
>     libcxx/trunk/src/experimental/filesystem/filesystem_common.h
>     libcxx/trunk/src/experimental/filesystem/operations.cpp
>     libcxx/trunk/test/libcxx/experimental/filesystem/class.
> directory_entry/directory_entry.mods/last_write_time.sh.cpp
>     libcxx/trunk/test/libcxx/experimental/filesystem/
> convert_file_time.sh.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.
> filesystem.synopsis/file_time_type.pass.cpp
>     libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp
>
> Modified: libcxx/trunk/include/experimental/filesystem
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/
> experimental/filesystem?rev=337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/include/experimental/filesystem (original)
> +++ libcxx/trunk/include/experimental/filesystem Wed Jul 25 13:51:49 2018
> @@ -260,7 +260,37 @@ _LIBCPP_PUSH_MACROS
>
>  _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM
>
> -typedef chrono::time_point<std::chrono::system_clock>  file_time_type;
> +struct _FilesystemClock {
> +#if !defined(_LIBCPP_HAS_NO_INT128)
> +  typedef __int128_t rep;
> +  typedef nano period;
> +#else
> +  typedef long long rep;
> +  typedef nano period;
> +#endif
> +
> +  typedef chrono::duration<rep, period> duration;
> +  typedef chrono::time_point<_FilesystemClock> time_point;
> +
> +  static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
> +
> +  _LIBCPP_FUNC_VIS static time_point now() noexcept;
> +
> +  _LIBCPP_INLINE_VISIBILITY
> +  static time_t to_time_t(const time_point& __t) noexcept {
> +    typedef chrono::duration<rep> __secs;
> +    return time_t(
> +        chrono::duration_cast<__secs>(__t.time_since_epoch()).count());
> +  }
> +
> +  _LIBCPP_INLINE_VISIBILITY
> +  static time_point from_time_t(time_t __t) noexcept {
> +    typedef chrono::duration<rep> __secs;
> +    return time_point(__secs(__t));
> +  }
> +};
> +
> +typedef chrono::time_point<_FilesystemClock> file_time_type;
>
>  struct _LIBCPP_TYPE_VIS space_info
>  {
>
> Modified: libcxx/trunk/src/chrono.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/
> chrono.cpp?rev=337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/src/chrono.cpp (original)
> +++ libcxx/trunk/src/chrono.cpp Wed Jul 25 13:51:49 2018
> @@ -11,27 +11,10 @@
>  #include "cerrno"        // errno
>  #include "system_error"  // __throw_system_error
>  #include <time.h>        // clock_gettime, CLOCK_MONOTONIC and
> CLOCK_REALTIME
> +#include "include/apple_availability.h"
>
> -#if (__APPLE__)
> -#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101200
> -#define _LIBCXX_USE_CLOCK_GETTIME
> -#endif
> -#elif defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 100000
> -#define _LIBCXX_USE_CLOCK_GETTIME
> -#endif
> -#elif defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ >= 100000
> -#define _LIBCXX_USE_CLOCK_GETTIME
> -#endif
> -#elif defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 30000
> -#define _LIBCXX_USE_CLOCK_GETTIME
> -#endif
> -#endif // __ENVIRONMENT_.*_VERSION_MIN_REQUIRED__
> -#else
> -#define _LIBCXX_USE_CLOCK_GETTIME
> +#if !defined(__APPLE__)
> +#define _LIBCPP_USE_CLOCK_GETTIME
>  #endif // __APPLE__
>
>  #if defined(_LIBCPP_WIN32API)
> @@ -42,7 +25,7 @@
>  #include <winapifamily.h>
>  #endif
>  #else
> -#if !defined(CLOCK_REALTIME) || !defined(_LIBCXX_USE_CLOCK_GETTIME)
> +#if !defined(CLOCK_REALTIME) || !defined(_LIBCPP_USE_CLOCK_GETTIME)
>  #include <sys/time.h>        // for gettimeofday and timeval
>  #endif // !defined(CLOCK_REALTIME)
>  #endif // defined(_LIBCPP_WIN32API)
> @@ -92,16 +75,16 @@ system_clock::now() _NOEXCEPT
>                         static_cast<__int64>(ft.dwLowDateTime)};
>    return time_point(duration_cast<duration>(d - nt_to_unix_epoch));
>  #else
> -#if defined(_LIBCXX_USE_CLOCK_GETTIME) && defined(CLOCK_REALTIME)
> -    struct timespec tp;
> -    if (0 != clock_gettime(CLOCK_REALTIME, &tp))
> -        __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME)
> failed");
> -    return time_point(seconds(tp.tv_sec) + microseconds(tp.tv_nsec /
> 1000));
> +#if defined(_LIBCPP_USE_CLOCK_GETTIME) && defined(CLOCK_REALTIME)
> +  struct timespec tp;
> +  if (0 != clock_gettime(CLOCK_REALTIME, &tp))
> +    __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
> +  return time_point(seconds(tp.tv_sec) + microseconds(tp.tv_nsec / 1000));
>  #else
>      timeval tv;
>      gettimeofday(&tv, 0);
>      return time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec));
> -#endif // _LIBCXX_USE_CLOCK_GETTIME && CLOCK_REALTIME
> +#endif // _LIBCPP_USE_CLOCK_GETTIME && CLOCK_REALTIME
>  #endif
>  }
>
> @@ -129,7 +112,7 @@ const bool steady_clock::is_steady;
>  #if defined(__APPLE__)
>
>  // Darwin libc versions >= 1133 provide ns precision via CLOCK_UPTIME_RAW
> -#if defined(_LIBCXX_USE_CLOCK_GETTIME) && defined(CLOCK_UPTIME_RAW)
> +#if defined(_LIBCPP_USE_CLOCK_GETTIME) && defined(CLOCK_UPTIME_RAW)
>  steady_clock::time_point
>  steady_clock::now() _NOEXCEPT
>  {
> @@ -191,7 +174,7 @@ steady_clock::now() _NOEXCEPT
>      static FP fp = init_steady_clock();
>      return time_point(duration(fp()));
>  }
> -#endif // defined(_LIBCXX_USE_CLOCK_GETTIME) && defined(CLOCK_UPTIME_RAW)
> +#endif // defined(_LIBCPP_USE_CLOCK_GETTIME) && defined(CLOCK_UPTIME_RAW)
>
>  #elif defined(_LIBCPP_WIN32API)
>
>
> Modified: libcxx/trunk/src/experimental/filesystem/filesystem_common.h
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/
> experimental/filesystem/filesystem_common.h?rev=
> 337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/src/experimental/filesystem/filesystem_common.h
> (original)
> +++ libcxx/trunk/src/experimental/filesystem/filesystem_common.h Wed Jul
> 25 13:51:49 2018
> @@ -23,33 +23,17 @@
>
>  #include <experimental/filesystem>
>
> -#if (__APPLE__)
> -#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101300
> -#define _LIBCXX_USE_UTIMENSAT
> -#endif
> -#elif defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 110000
> -#define _LIBCXX_USE_UTIMENSAT
> -#endif
> -#elif defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ >= 110000
> -#define _LIBCXX_USE_UTIMENSAT
> -#endif
> -#elif defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__)
> -#if __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 40000
> -#define _LIBCXX_USE_UTIMENSAT
> -#endif
> -#endif // __ENVIRONMENT_.*_VERSION_MIN_REQUIRED__
> -#else
> +#include "../../include/apple_availability.h"
> +
> +#if !defined(__APPLE__)
>  // We can use the presence of UTIME_OMIT to detect platforms that provide
>  // utimensat.
>  #if defined(UTIME_OMIT)
> -#define _LIBCXX_USE_UTIMENSAT
> +#define _LIBCPP_USE_UTIMENSAT
> +#endif
>  #endif
> -#endif // __APPLE__
>
> -#if !defined(_LIBCXX_USE_UTIMENSAT)
> +#if !defined(_LIBCPP_USE_UTIMENSAT)
>  #include <sys/time.h> // for ::utimes as used in __last_write_time
>  #endif
>
> @@ -212,76 +196,119 @@ private:
>    ErrorHandler& operator=(ErrorHandler const&) = delete;
>  };
>
> -namespace time_util {
> +using chrono::duration;
> +using chrono::duration_cast;
>
> -using namespace chrono;
> +using TimeSpec = struct ::timespec;
> +using StatT = struct ::stat;
>
> -template <class FileTimeT,
> +template <class FileTimeT, class TimeT,
>            bool IsFloat = is_floating_point<typename
> FileTimeT::rep>::value>
> -struct fs_time_util_base {
> -  static constexpr seconds::rep max_seconds =
> -      duration_cast<seconds>(FileTimeT::duration::max()).count();
> -
> -  static constexpr nanoseconds::rep max_nsec =
> -      duration_cast<nanoseconds>(FileTimeT::duration::max() -
> -                                 seconds(max_seconds))
> +struct time_util_base {
> +  using rep = typename FileTimeT::rep;
> +  using fs_duration = typename FileTimeT::duration;
> +  using fs_seconds = duration<rep>;
> +  using fs_nanoseconds = duration<rep, nano>;
> +  using fs_microseconds = duration<rep, micro>;
> +
> +  static constexpr rep max_seconds =
> +      duration_cast<fs_seconds>(FileTimeT::duration::max()).count();
> +
> +  static constexpr rep max_nsec =
> +      duration_cast<fs_nanoseconds>(FileTimeT::duration::max() -
> +                                    fs_seconds(max_seconds))
>            .count();
>
> -  static constexpr seconds::rep min_seconds =
> -      duration_cast<seconds>(FileTimeT::duration::min()).count();
> +  static constexpr rep min_seconds =
> +      duration_cast<fs_seconds>(FileTimeT::duration::min()).count();
>
> -  static constexpr nanoseconds::rep min_nsec_timespec =
> -      duration_cast<nanoseconds>(
> -          (FileTimeT::duration::min() - seconds(min_seconds)) +
> seconds(1))
> +  static constexpr rep min_nsec_timespec =
> +      duration_cast<fs_nanoseconds>(
> +          (FileTimeT::duration::min() - fs_seconds(min_seconds)) +
> +          fs_seconds(1))
>            .count();
>
> +private:
> +#if _LIBCPP_STD_VER > 11
> +  static constexpr fs_duration get_min_nsecs() {
> +    return duration_cast<fs_duration>(
> +        fs_nanoseconds(min_nsec_timespec) -
> +        duration_cast<fs_nanoseconds>(fs_seconds(1)));
> +  }
>    // Static assert that these values properly round trip.
> -  static_assert((seconds(min_seconds) +
> -                 duration_cast<microseconds>(
> nanoseconds(min_nsec_timespec))) -
> -                        duration_cast<microseconds>(seconds(1)) ==
> +  static_assert(fs_seconds(min_seconds) + get_min_nsecs() ==
>                      FileTimeT::duration::min(),
> -                "");
> +                "value doesn't roundtrip");
> +
> +  static constexpr bool check_range() {
> +    // This kinda sucks, but it's what happens when we don't have
> __int128_t.
> +    if (sizeof(TimeT) == sizeof(rep)) {
> +      typedef duration<long long, ratio<3600 * 24 * 365> > Years;
> +      return duration_cast<Years>(fs_seconds(max_seconds)) > Years(250)
> &&
> +             duration_cast<Years>(fs_seconds(min_seconds)) < Years(-250);
> +    }
> +    return max_seconds >= numeric_limits<TimeT>::max() &&
> +           min_seconds <= numeric_limits<TimeT>::min();
> +  }
> +  static_assert(check_range(), "the representable range is unacceptable
> small");
> +#endif
>  };
>
> -template <class FileTimeT>
> -struct fs_time_util_base<FileTimeT, true> {
> -  static const long long max_seconds;
> -  static const long long max_nsec;
> -  static const long long min_seconds;
> -  static const long long min_nsec_timespec;
> +template <class FileTimeT, class TimeT>
> +struct time_util_base<FileTimeT, TimeT, true> {
> +  using rep = typename FileTimeT::rep;
> +  using fs_duration = typename FileTimeT::duration;
> +  using fs_seconds = duration<rep>;
> +  using fs_nanoseconds = duration<rep, nano>;
> +  using fs_microseconds = duration<rep, micro>;
> +
> +  static const rep max_seconds;
> +  static const rep max_nsec;
> +  static const rep min_seconds;
> +  static const rep min_nsec_timespec;
>  };
>
> -template <class FileTimeT>
> -const long long fs_time_util_base<FileTimeT, true>::max_seconds =
> -    duration_cast<seconds>(FileTimeT::duration::max()).count();
> -
> -template <class FileTimeT>
> -const long long fs_time_util_base<FileTimeT, true>::max_nsec =
> -    duration_cast<nanoseconds>(FileTimeT::duration::max() -
> -                               seconds(max_seconds))
> +template <class FileTimeT, class TimeT>
> +const typename FileTimeT::rep
> +    time_util_base<FileTimeT, TimeT, true>::max_seconds =
> +        duration_cast<fs_seconds>(FileTimeT::duration::max()).count();
> +
> +template <class FileTimeT, class TimeT>
> +const typename FileTimeT::rep time_util_base<FileTimeT, TimeT,
> true>::max_nsec =
> +    duration_cast<fs_nanoseconds>(FileTimeT::duration::max() -
> +                                  fs_seconds(max_seconds))
>          .count();
>
> -template <class FileTimeT>
> -const long long fs_time_util_base<FileTimeT, true>::min_seconds =
> -    duration_cast<seconds>(FileTimeT::duration::min()).count();
> -
> -template <class FileTimeT>
> -const long long fs_time_util_base<FileTimeT, true>::min_nsec_timespec =
> -    duration_cast<nanoseconds>(
> -        (FileTimeT::duration::min() - seconds(min_seconds)) + seconds(1))
> -        .count();
> +template <class FileTimeT, class TimeT>
> +const typename FileTimeT::rep
> +    time_util_base<FileTimeT, TimeT, true>::min_seconds =
> +        duration_cast<fs_seconds>(FileTimeT::duration::min()).count();
> +
> +template <class FileTimeT, class TimeT>
> +const typename FileTimeT::rep
> +    time_util_base<FileTimeT, TimeT, true>::min_nsec_timespec =
> +        duration_cast<fs_nanoseconds>((FileTimeT::duration::min() -
> +                                       fs_seconds(min_seconds)) +
> +                                      fs_seconds(1))
> +            .count();
>
>  template <class FileTimeT, class TimeT, class TimeSpecT>
> -struct fs_time_util : fs_time_util_base<FileTimeT> {
> -  using Base = fs_time_util_base<FileTimeT>;
> +struct time_util : time_util_base<FileTimeT, TimeT> {
> +  using Base = time_util_base<FileTimeT, TimeT>;
>    using Base::max_nsec;
>    using Base::max_seconds;
>    using Base::min_nsec_timespec;
>    using Base::min_seconds;
>
> +  using typename Base::fs_duration;
> +  using typename Base::fs_microseconds;
> +  using typename Base::fs_nanoseconds;
> +  using typename Base::fs_seconds;
> +
>  public:
>    template <class CType, class ChronoType>
> -  static bool checked_set(CType* out, ChronoType time) {
> +  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool checked_set(CType* out,
> +                                                        ChronoType time) {
>      using Lim = numeric_limits<CType>;
>      if (time > Lim::max() || time < Lim::min())
>        return false;
> @@ -291,21 +318,21 @@ public:
>
>    static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool is_representable(TimeSpecT
> tm) {
>      if (tm.tv_sec >= 0) {
> -      return (tm.tv_sec < max_seconds) ||
> +      return tm.tv_sec < max_seconds ||
>               (tm.tv_sec == max_seconds && tm.tv_nsec <= max_nsec);
>      } else if (tm.tv_sec == (min_seconds - 1)) {
>        return tm.tv_nsec >= min_nsec_timespec;
>      } else {
> -      return (tm.tv_sec >= min_seconds);
> +      return tm.tv_sec >= min_seconds;
>      }
>    }
>
>    static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool is_representable(FileTimeT
> tm) {
> -    auto secs = duration_cast<seconds>(tm.time_since_epoch());
> -    auto nsecs = duration_cast<nanoseconds>(tm.time_since_epoch() -
> secs);
> +    auto secs = duration_cast<fs_seconds>(tm.time_since_epoch());
> +    auto nsecs = duration_cast<fs_nanoseconds>(tm.time_since_epoch() -
> secs);
>      if (nsecs.count() < 0) {
> -      secs = secs + seconds(1);
> -      nsecs = nsecs + seconds(1);
> +      secs = secs + fs_seconds(1);
> +      nsecs = nsecs + fs_seconds(1);
>      }
>      using TLim = numeric_limits<TimeT>;
>      if (secs.count() >= 0)
> @@ -314,49 +341,45 @@ public:
>    }
>
>    static _LIBCPP_CONSTEXPR_AFTER_CXX11 FileTimeT
> -  convert_timespec(TimeSpecT tm) {
> -    auto adj_msec = duration_cast<microseconds>(nanoseconds(tm.tv_nsec));
> -    if (tm.tv_sec >= 0) {
> -      auto Dur = seconds(tm.tv_sec) + microseconds(adj_msec);
> -      return FileTimeT(Dur);
> -    } else if (duration_cast<microseconds>(nanoseconds(tm.tv_nsec)).count()
> ==
> -               0) {
> -      return FileTimeT(seconds(tm.tv_sec));
> +  convert_from_timespec(TimeSpecT tm) {
> +    if (tm.tv_sec >= 0 || tm.tv_nsec == 0) {
> +      return FileTimeT(fs_seconds(tm.tv_sec) +
> +                       duration_cast<fs_duration>(fs_
> nanoseconds(tm.tv_nsec)));
>      } else { // tm.tv_sec < 0
> -      auto adj_subsec =
> -          duration_cast<microseconds>(seconds(1) -
> nanoseconds(tm.tv_nsec));
> -      auto Dur = seconds(tm.tv_sec + 1) - adj_subsec;
> +      auto adj_subsec = duration_cast<fs_duration>(fs_seconds(1) -
> +
>  fs_nanoseconds(tm.tv_nsec));
> +      auto Dur = fs_seconds(tm.tv_sec + 1) - adj_subsec;
>        return FileTimeT(Dur);
>      }
>    }
>
> -  template <class SubSecDurT, class SubSecT>
> -  static bool set_times_checked(TimeT* sec_out, SubSecT* subsec_out,
> -                                FileTimeT tp) {
> +  template <class SubSecT>
> +  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool
> +  set_times_checked(TimeT* sec_out, SubSecT* subsec_out, FileTimeT tp) {
>      auto dur = tp.time_since_epoch();
> -    auto sec_dur = duration_cast<seconds>(dur);
> -    auto subsec_dur = duration_cast<SubSecDurT>(dur - sec_dur);
> +    auto sec_dur = duration_cast<fs_seconds>(dur);
> +    auto subsec_dur = duration_cast<fs_nanoseconds>(dur - sec_dur);
>      // The tv_nsec and tv_usec fields must not be negative so adjust
> accordingly
>      if (subsec_dur.count() < 0) {
>        if (sec_dur.count() > min_seconds) {
> -        sec_dur -= seconds(1);
> -        subsec_dur += seconds(1);
> +        sec_dur -= fs_seconds(1);
> +        subsec_dur += fs_seconds(1);
>        } else {
> -        subsec_dur = SubSecDurT::zero();
> +        subsec_dur = fs_nanoseconds::zero();
>        }
>      }
>      return checked_set(sec_out, sec_dur.count()) &&
>             checked_set(subsec_out, subsec_dur.count());
>    }
> +  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool
> convert_to_timespec(TimeSpecT& dest,
> +                                                                FileTimeT
> tp) {
> +    if (!is_representable(tp))
> +      return false;
> +    return set_times_checked(&dest.tv_sec, &dest.tv_nsec, tp);
> +  }
>  };
>
> -} // namespace time_util
> -
> -
> -using TimeSpec = struct ::timespec;
> -using StatT = struct ::stat;
> -
> -using FSTime = time_util::fs_time_util<file_time_type, time_t, struct
> timespec>;
> +using fs_time = time_util<file_time_type, time_t, TimeSpec>;
>
>  #if defined(__APPLE__)
>  TimeSpec extract_mtime(StatT const& st) { return st.st_mtimespec; }
> @@ -366,20 +389,18 @@ TimeSpec extract_mtime(StatT const& st)
>  TimeSpec extract_atime(StatT const& st) { return st.st_atim; }
>  #endif
>
> -#if !defined(_LIBCXX_USE_UTIMENSAT)
> -using TimeStruct = struct ::timeval;
> -using TimeStructArray = TimeStruct[2];
> -#else
> -using TimeStruct = TimeSpec;
> -using TimeStructArray = TimeStruct[2];
> -#endif
> -
> -bool SetFileTimes(const path& p, TimeStructArray const& TS,
> -                  error_code& ec) {
> -#if !defined(_LIBCXX_USE_UTIMENSAT)
> -  if (::utimes(p.c_str(), TS) == -1)
> +bool set_file_times(const path& p, std::array<TimeSpec, 2> const& TS,
> +                    error_code& ec) {
> +#if !defined(_LIBCPP_USE_UTIMENSAT)
> +  using namespace chrono;
> +  auto Convert = [](long nsec) {
> +    return duration_cast<microseconds>(nanoseconds(nsec)).count();
> +  };
> +  struct ::timeval ConvertedTS[2] = {{TS[0].tv_sec,
> Convert(TS[0].tv_nsec)},
> +                                     {TS[1].tv_sec,
> Convert(TS[1].tv_nsec)}};
>

This causes the '-Wc++11-narrowing' warning on Darwin:

filesystem_common.h:399:53: error: non-constant-expression cannot be
narrowed from type 'long long' to '__darwin_suseconds_t' (aka 'int') in
initializer list [-Wc++11-narrowing] struct ::timeval ConvertedTS[2] =
{{TS[0].tv_sec, Convert(TS[0].tv_nsec)}, ^~~~~~~~~~~~~~~~~~~~~~
I'll work on a fix commit.


> +  if (::utimes(p.c_str(), ConvertedTS) == -1)
>  #else
> -  if (::utimensat(AT_FDCWD, p.c_str(), TS, 0) == -1)
> +  if (::utimensat(AT_FDCWD, p.c_str(), TS.data(), 0) == -1)
>  #endif
>    {
>      ec = capture_errno();
> @@ -388,25 +409,9 @@ bool SetFileTimes(const path& p, TimeStr
>    return false;
>  }
>
> -void SetTimeStructTo(TimeStruct& TS, TimeSpec ToTS) {
> -  using namespace chrono;
> -  TS.tv_sec = ToTS.tv_sec;
> -#if !defined(_LIBCXX_USE_UTIMENSAT)
> -  TS.tv_usec = duration_cast<microseconds>(nanoseconds(ToTS.tv_nsec)).
> count();
> -#else
> -  TS.tv_nsec = ToTS.tv_nsec;
> -#endif
> -}
> -
> -bool SetTimeStructTo(TimeStruct& TS, file_time_type NewTime) {
> -  using namespace chrono;
> -#if !defined(_LIBCXX_USE_UTIMENSAT)
> -  return !FSTime::set_times_checked<microseconds>(&TS.tv_sec,
> &TS.tv_usec,
> -                                                  NewTime);
> -#else
> -  return !FSTime::set_times_checked<nanoseconds>(&TS.tv_sec, &TS.tv_nsec,
> -                                                 NewTime);
> -#endif
> +bool set_time_spec_to(TimeSpec& TS, file_time_type NewTime) {
> +  return !fs_time::set_times_checked(
> +      &TS.tv_sec, &TS.tv_nsec, NewTime);
>  }
>
>  } // namespace
>
> Modified: libcxx/trunk/src/experimental/filesystem/operations.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/
> experimental/filesystem/operations.cpp?rev=337960&r1=
> 337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/src/experimental/filesystem/operations.cpp (original)
> +++ libcxx/trunk/src/experimental/filesystem/operations.cpp Wed Jul 25
> 13:51:49 2018
> @@ -23,6 +23,7 @@
>  #include <unistd.h>
>  #include <sys/stat.h>
>  #include <sys/statvfs.h>
> +#include <time.h>
>  #include <fcntl.h>  /* values for fchmodat */
>
>  #if defined(__linux__)
> @@ -36,6 +37,14 @@
>  # define _LIBCPP_USE_COPYFILE
>  #endif
>
> +#if !defined(__APPLE__)
> +#define _LIBCPP_USE_CLOCK_GETTIME
> +#endif
> +
> +#if !defined(CLOCK_REALTIME) || !defined(_LIBCPP_USE_CLOCK_GETTIME)
> +#include <sys/time.h> // for gettimeofday and timeval
> +#endif                // !defined(CLOCK_REALTIME)
> +
>  #if defined(_LIBCPP_COMPILER_GCC)
>  #if _GNUC_VER < 500
>  #pragma GCC diagnostic ignored "-Wmissing-field-initializers"
> @@ -44,9 +53,6 @@
>
>  _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM
>
> -filesystem_error::~filesystem_error() {}
> -
> -
>  namespace { namespace parser
>  {
>
> @@ -355,7 +361,7 @@ private:
>    explicit FileDescriptor(const path* p, int fd = -1) : name(*p), fd(fd)
> {}
>  };
>
> -perms posix_get_perms(const struct ::stat& st) noexcept {
> +perms posix_get_perms(const StatT& st) noexcept {
>    return static_cast<perms>(st.st_mode) & perms::mask;
>  }
>
> @@ -364,8 +370,7 @@ perms posix_get_perms(const struct ::sta
>  }
>
>  file_status create_file_status(error_code& m_ec, path const& p,
> -                               const struct ::stat& path_stat,
> -                               error_code* ec) {
> +                               const StatT& path_stat, error_code* ec) {
>    if (ec)
>      *ec = m_ec;
>    if (m_ec && (m_ec.value() == ENOENT || m_ec.value() == ENOTDIR)) {
> @@ -400,8 +405,7 @@ file_status create_file_status(error_cod
>    return fs_tmp;
>  }
>
> -file_status posix_stat(path const& p, struct ::stat& path_stat,
> -                       error_code* ec) {
> +file_status posix_stat(path const& p, StatT& path_stat, error_code* ec) {
>    error_code m_ec;
>    if (::stat(p.c_str(), &path_stat) == -1)
>      m_ec = detail::capture_errno();
> @@ -409,12 +413,11 @@ file_status posix_stat(path const& p, st
>  }
>
>  file_status posix_stat(path const& p, error_code* ec) {
> -  struct ::stat path_stat;
> +  StatT path_stat;
>    return posix_stat(p, path_stat, ec);
>  }
>
> -file_status posix_lstat(path const& p, struct ::stat& path_stat,
> -                        error_code* ec) {
> +file_status posix_lstat(path const& p, StatT& path_stat, error_code* ec) {
>    error_code m_ec;
>    if (::lstat(p.c_str(), &path_stat) == -1)
>      m_ec = detail::capture_errno();
> @@ -422,7 +425,7 @@ file_status posix_lstat(path const& p, s
>  }
>
>  file_status posix_lstat(path const& p, error_code* ec) {
> -  struct ::stat path_stat;
> +  StatT path_stat;
>    return posix_lstat(p, path_stat, ec);
>  }
>
> @@ -464,10 +467,32 @@ file_status FileDescriptor::refresh_stat
>  using detail::capture_errno;
>  using detail::ErrorHandler;
>  using detail::StatT;
> +using detail::TimeSpec;
>  using parser::createView;
>  using parser::PathParser;
>  using parser::string_view_t;
>
> +const bool _FilesystemClock::is_steady;
> +
> +_FilesystemClock::time_point _FilesystemClock::now() noexcept {
> +  typedef chrono::duration<rep> __secs;
> +#if defined(_LIBCPP_USE_CLOCK_GETTIME) && defined(CLOCK_REALTIME)
> +  typedef chrono::duration<rep, nano> __nsecs;
> +  struct timespec tp;
> +  if (0 != clock_gettime(CLOCK_REALTIME, &tp))
> +    __throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
> +  return time_point(__secs(tp.tv_sec) +
> +                    chrono::duration_cast<duration>(__nsecs(tp.tv_nsec))
> );
> +#else
> +  typedef chrono::duration<rep, micro> __microsecs;
> +  timeval tv;
> +  gettimeofday(&tv, 0);
> +  return time_point(__secs(tv.tv_sec) + __microsecs(tv.tv_usec));
> +#endif // _LIBCPP_USE_CLOCK_GETTIME && CLOCK_REALTIME
> +}
> +
> +filesystem_error::~filesystem_error() {}
> +
>  void filesystem_error::__create_what(int __num_paths) {
>    const char* derived_what = system_error::what();
>    __storage_->__what_ = [&]() -> string {
> @@ -525,14 +550,14 @@ void __copy(const path& from, const path
>    const bool sym_status2 = bool(options & copy_options::copy_symlinks);
>
>    error_code m_ec1;
> -  struct ::stat f_st = {};
> +  StatT f_st = {};
>    const file_status f = sym_status || sym_status2
>                              ? detail::posix_lstat(from, f_st, &m_ec1)
>                              : detail::posix_stat(from, f_st, &m_ec1);
>    if (m_ec1)
>      return err.report(m_ec1);
>
> -  struct ::stat t_st = {};
> +  StatT t_st = {};
>    const file_status t = sym_status ? detail::posix_lstat(to, t_st, &m_ec1)
>                                     : detail::posix_stat(to, t_st, &m_ec1);
>
> @@ -916,7 +941,7 @@ uintmax_t __file_size(const path& p, err
>    ErrorHandler<uintmax_t> err("file_size", ec, &p);
>
>    error_code m_ec;
> -  struct ::stat st;
> +  StatT st;
>    file_status fst = detail::posix_stat(p, st, &m_ec);
>    if (!exists(fst) || !is_regular_file(fst)) {
>      errc error_kind =
> @@ -966,14 +991,14 @@ bool __fs_is_empty(const path& p, error_
>
>  static file_time_type __extract_last_write_time(const path& p, const
> StatT& st,
>                                                  error_code* ec) {
> -  using detail::FSTime;
> +  using detail::fs_time;
>    ErrorHandler<file_time_type> err("last_write_time", ec, &p);
>
>    auto ts = detail::extract_mtime(st);
> -  if (!FSTime::is_representable(ts))
> +  if (!fs_time::is_representable(ts))
>      return err.report(errc::value_too_large);
>
> -  return FSTime::convert_timespec(ts);
> +  return fs_time::convert_from_timespec(ts);
>  }
>
>  file_time_type __last_write_time(const path& p, error_code *ec)
> @@ -992,30 +1017,27 @@ file_time_type __last_write_time(const p
>  void __last_write_time(const path& p, file_time_type new_time,
>                         error_code *ec)
>  {
> -    using namespace chrono;
> -    using namespace detail;
> -
>      ErrorHandler<void> err("last_write_time", ec, &p);
>
>      error_code m_ec;
> -    TimeStructArray tbuf;
> -#if !defined(_LIBCXX_USE_UTIMENSAT)
> +    array<TimeSpec, 2> tbuf;
> +#if !defined(_LIBCPP_USE_UTIMENSAT)
>      // This implementation has a race condition between determining the
>      // last access time and attempting to set it to the same value using
>      // ::utimes
> -    struct ::stat st;
> +    StatT st;
>      file_status fst = detail::posix_stat(p, st, &m_ec);
> -    if (m_ec && !status_known(fst))
> +    if (m_ec)
>        return err.report(m_ec);
> -    SetTimeStructTo(tbuf[0], detail::extract_atime(st));
> +    tbuf[0] = detail::extract_atime(st);
>  #else
>      tbuf[0].tv_sec = 0;
>      tbuf[0].tv_nsec = UTIME_OMIT;
>  #endif
> -    if (SetTimeStructTo(tbuf[1], new_time))
> -      return err.report(errc::invalid_argument);
> +    if (detail::set_time_spec_to(tbuf[1], new_time))
> +      return err.report(errc::value_too_large);
>
> -    SetFileTimes(p, tbuf, m_ec);
> +    detail::set_file_times(p, tbuf, m_ec);
>      if (m_ec)
>        return err.report(m_ec);
>  }
> @@ -1591,7 +1613,7 @@ error_code directory_entry::__do_refresh
>    __data_.__reset();
>    error_code failure_ec;
>
> -  struct ::stat full_st;
> +  StatT full_st;
>    file_status st = detail::posix_lstat(__p_, full_st, &failure_ec);
>    if (!status_known(st)) {
>      __data_.__reset();
>
> Added: libcxx/trunk/src/include/apple_availability.h
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/src/
> include/apple_availability.h?rev=337960&view=auto
> ============================================================
> ==================
> --- libcxx/trunk/src/include/apple_availability.h (added)
> +++ libcxx/trunk/src/include/apple_availability.h Wed Jul 25 13:51:49 2018
> @@ -0,0 +1,52 @@
> +//===------------------------ apple_availability.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_SRC_INCLUDE_APPLE_AVAILABILITY_H
> +#define _LIBCPP_SRC_INCLUDE_APPLE_AVAILABILITY_H
> +
> +#if defined(__APPLE__)
> +
> +#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101300
> +#define _LIBCPP_USE_UTIMENSAT
> +#endif
> +#elif defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 110000
> +#define _LIBCPP_USE_UTIMENSAT
> +#endif
> +#elif defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ >= 110000
> +#define _LIBCPP_USE_UTIMENSAT
> +#endif
> +#elif defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 40000
> +#define _LIBCPP_USE_UTIMENSAT
> +#endif
> +#endif // __ENVIRONMENT_.*_VERSION_MIN_REQUIRED__
> +
> +#if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101200
> +#define _LIBCPP_USE_CLOCK_GETTIME
> +#endif
> +#elif defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ >= 100000
> +#define _LIBCPP_USE_CLOCK_GETTIME
> +#endif
> +#elif defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ >= 100000
> +#define _LIBCPP_USE_CLOCK_GETTIME
> +#endif
> +#elif defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__)
> +#if __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 30000
> +#define _LIBCPP_USE_CLOCK_GETTIME
> +#endif
> +#endif // __ENVIRONMENT_.*_VERSION_MIN_REQUIRED__
> +
> +#endif // __APPLE__
> +
> +#endif // _LIBCPP_SRC_INCLUDE_APPLE_AVAILABILITY_H
>
> Modified: libcxx/trunk/test/libcxx/experimental/filesystem/class.
> directory_entry/directory_entry.mods/last_write_time.sh.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/
> libcxx/experimental/filesystem/class.directory_entry/directory_entry.mods/
> last_write_time.sh.cpp?rev=337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/libcxx/experimental/filesystem/class.
> directory_entry/directory_entry.mods/last_write_time.sh.cpp (original)
> +++ libcxx/trunk/test/libcxx/experimental/filesystem/class.
> directory_entry/directory_entry.mods/last_write_time.sh.cpp Wed Jul 25
> 13:51:49 2018
> @@ -41,9 +41,7 @@ TEST_CASE(last_write_time_not_representa
>    ToTime.tv_sec = std::numeric_limits<decltype(ToTime.tv_sec)>::max();
>    ToTime.tv_nsec = duration_cast<nanoseconds>(seconds(1)).count() - 1;
>
> -  TimeStructArray TS;
> -  SetTimeStructTo(TS[0], ToTime);
> -  SetTimeStructTo(TS[1], ToTime);
> +  std::array<TimeSpec, 2> TS = {ToTime, ToTime};
>
>    file_time_type old_time = last_write_time(file);
>    directory_entry ent(file);
> @@ -57,9 +55,7 @@ TEST_CASE(last_write_time_not_representa
>    file_time_type rep_value;
>    {
>      std::error_code ec;
> -    if (SetFileTimes(file, TS, ec)) {
> -      TEST_REQUIRE(false && "unsupported");
> -    }
> +    TEST_REQUIRE(!set_file_times(file, TS, ec));
>      ec.clear();
>      rep_value = last_write_time(file, ec);
>      IsRepresentable = !bool(ec);
> @@ -82,7 +78,7 @@ TEST_CASE(last_write_time_not_representa
>
>      ExceptionChecker CheckExcept(file, expected_err,
>                                   "directory_entry::last_write_time");
> -    TEST_CHECK_THROW_RESULT(fs::filesystem_error, CheckExcept,
> +    TEST_CHECK_THROW_RESULT(filesystem_error, CheckExcept,
>                              ent.last_write_time());
>
>    } else {
>
> Modified: libcxx/trunk/test/libcxx/experimental/filesystem/
> convert_file_time.sh.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/
> libcxx/experimental/filesystem/convert_file_time.
> sh.cpp?rev=337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/libcxx/experimental/filesystem/convert_file_time.sh.cpp
> (original)
> +++ libcxx/trunk/test/libcxx/experimental/filesystem/convert_file_time.sh.cpp
> Wed Jul 25 13:51:49 2018
> @@ -25,15 +25,23 @@
>
>  #include "filesystem_common.h"
>
> +#ifndef __SIZEOF_INT128__
> +#define TEST_HAS_NO_INT128_T
> +#endif
> +
>  using namespace std::chrono;
>  namespace fs = std::experimental::filesystem;
>  using fs::file_time_type;
> -using fs::detail::time_util::fs_time_util;
> +using fs::detail::time_util;
> +
> +#ifdef TEST_HAS_NO_INT128_T
> +static_assert(sizeof(fs::file_time_type::rep) <= 8, "");
> +#endif
>
> -enum TestKind { TK_64Bit, TK_32Bit, TK_FloatingPoint };
> +enum TestKind { TK_128Bit, TK_64Bit, TK_32Bit, TK_FloatingPoint };
>
> -template <class FileTimeT, class TimeT, class TimeSpec>
> -constexpr TestKind getTestKind() {
> +template <class TimeT>
> +constexpr TestKind getTimeTTestKind() {
>    if (sizeof(TimeT) == 8 && !std::is_floating_point<TimeT>::value)
>      return TK_64Bit;
>    else if (sizeof(TimeT) == 4 && !std::is_floating_point<TimeT>::value)
> @@ -43,17 +51,99 @@ constexpr TestKind getTestKind() {
>    else
>      assert(false && "test kind not supported");
>  }
> +template <class FileTimeT>
> +constexpr TestKind getFileTimeTestKind() {
> +  using Rep = typename FileTimeT::rep;
> +  if (std::is_floating_point<Rep>::value)
> +    return TK_FloatingPoint;
> +  if (sizeof(Rep) == 16)
> +    return TK_128Bit;
> +  if (sizeof(Rep) == 8)
> +    return TK_64Bit;
> +  assert(false && "test kind not supported");
> +}
>
>  template <class FileTimeT, class TimeT, class TimeSpecT,
> -          class Base = fs_time_util<FileTimeT, TimeT, TimeSpecT>,
> -          TestKind = getTestKind<FileTimeT, TimeT, TimeSpecT>()>
> -struct check_is_representable;
> +          class Base = time_util<FileTimeT, TimeT, TimeSpecT>,
> +          TestKind = getTimeTTestKind<TimeT>(),
> +          TestKind = getFileTimeTestKind<FileTimeT>()>
> +struct test_case;
>
>  template <class FileTimeT, class TimeT, class TimeSpecT, class Base>
> -struct check_is_representable<FileTimeT, TimeT, TimeSpecT, Base,
> TK_64Bit>
> +struct test_case<FileTimeT, TimeT, TimeSpecT, Base, TK_64Bit, TK_128Bit>
>      : public Base {
>
> -  using Base::convert_timespec;
> +  using Base::convert_from_timespec;
> +  using Base::convert_to_timespec;
> +  using Base::is_representable;
> +  using Base::max_nsec;
> +  using Base::max_seconds;
> +  using Base::min_nsec_timespec;
> +  using Base::min_seconds;
> +
> +  static constexpr auto max_time_t = std::numeric_limits<TimeT>::max();
> +  static constexpr auto min_time_t = std::numeric_limits<TimeT>::min();
> +
> +  static constexpr bool test_timespec() {
> +    static_assert(is_representable(TimeSpecT{max_time_t, 0}), "");
> +    static_assert(is_representable(TimeSpecT{max_time_t, 999999999}),
> "");
> +    static_assert(is_representable(TimeSpecT{max_time_t, 1000000000}),
> "");
> +    static_assert(is_representable(TimeSpecT{max_time_t, max_nsec}), "");
> +
> +    static_assert(is_representable(TimeSpecT{min_time_t, 0}), "");
> +    static_assert(is_representable(TimeSpecT{min_time_t, 999999999}),
> "");
> +    static_assert(is_representable(TimeSpecT{min_time_t, 1000000000}),
> "");
> +    static_assert(is_representable(TimeSpecT{min_time_t,
> min_nsec_timespec}),
> +                  "");
> +
> +    return true;
> +  }
> +
> +  static constexpr bool test_file_time_type() {
> +    // This kinda sucks. Oh well.
> +    static_assert(!Base::is_representable(FileTimeT::max()), "");
> +    static_assert(!Base::is_representable(FileTimeT::min()), "");
> +    return true;
> +  }
> +
> +  static constexpr bool check_round_trip(TimeSpecT orig) {
> +    TimeSpecT new_ts = {};
> +    FileTimeT out = convert_from_timespec(orig);
> +    assert(convert_to_timespec(new_ts, out));
> +    return new_ts.tv_sec == orig.tv_sec && new_ts.tv_nsec == orig.tv_nsec;
> +  }
> +
> +  static constexpr bool test_convert_timespec() {
> +    static_assert(check_round_trip({0, 0}), "");
> +    static_assert(check_round_trip({0, 1}), "");
> +    static_assert(check_round_trip({1, 1}), "");
> +    static_assert(check_round_trip({-1, 1}), "");
> +    static_assert(check_round_trip({max_time_t, max_nsec}), "");
> +    static_assert(check_round_trip({max_time_t, 123}), "");
> +    static_assert(check_round_trip({min_time_t, min_nsec_timespec}), "");
> +    static_assert(check_round_trip({min_time_t, 123}), "");
> +    return true;
> +  }
> +
> +  static bool test() {
> +    static_assert(test_timespec(), "");
> +    static_assert(test_file_time_type(), "");
> +    static_assert(test_convert_timespec(), "");
> +    return true;
> +  }
> +};
> +
> +template <class FileTimeT, class TimeT, class TimeSpecT, class Base>
> +struct test_case<FileTimeT, TimeT, TimeSpecT, Base, TK_32Bit, TK_128Bit>
> +    : public test_case<FileTimeT, TimeT, TimeSpecT, Base, TK_64Bit,
> TK_128Bit> {
> +
> +};
> +
> +template <class FileTimeT, class TimeT, class TimeSpecT, class Base>
> +struct test_case<FileTimeT, TimeT, TimeSpecT, Base, TK_64Bit, TK_64Bit>
> +    : public Base {
> +
> +  using Base::convert_from_timespec;
>    using Base::is_representable;
>    using Base::max_nsec;
>    using Base::max_seconds;
> @@ -88,24 +178,25 @@ struct check_is_representable<FileTimeT,
>    }
>
>    static constexpr bool test_convert_timespec() {
> -    static_assert(convert_timespec(TimeSpecT{max_seconds, max_nsec}) ==
> +    static_assert(convert_from_timespec(TimeSpecT{max_seconds,
> max_nsec}) ==
>                        FileTimeT::max(),
>                    "");
> -    static_assert(convert_timespec(TimeSpecT{max_seconds, max_nsec - 1})
> <
> +    static_assert(convert_from_timespec(TimeSpecT{max_seconds, max_nsec
> - 1}) <
>                        FileTimeT::max(),
>                    "");
> -    static_assert(convert_timespec(TimeSpecT{max_seconds - 1,
> 999999999}) <
> +    static_assert(convert_from_timespec(TimeSpecT{max_seconds - 1,
> 999999999}) <
>                        FileTimeT::max(),
>                    "");
> -    static_assert(convert_timespec(TimeSpecT{
> +    static_assert(convert_from_timespec(TimeSpecT{
>                        min_seconds - 1, min_nsec_timespec}) ==
> FileTimeT::min(),
>                    "");
> -    static_assert(
> -        convert_timespec(TimeSpecT{min_seconds - 1, min_nsec_timespec +
> 1}) >
> -            FileTimeT::min(),
> -        "");
> -    static_assert(
> -        convert_timespec(TimeSpecT{min_seconds, 0}) > FileTimeT::min(),
> "");
> +    static_assert(convert_from_timespec(
> +                      TimeSpecT{min_seconds - 1, min_nsec_timespec + 1}) >
> +                      FileTimeT::min(),
> +                  "");
> +    static_assert(convert_from_timespec(TimeSpecT{min_seconds, 0}) >
> +                      FileTimeT::min(),
> +                  "");
>      return true;
>    }
>
> @@ -118,12 +209,12 @@ struct check_is_representable<FileTimeT,
>  };
>
>  template <class FileTimeT, class TimeT, class TimeSpecT, class Base>
> -struct check_is_representable<FileTimeT, TimeT, TimeSpecT, Base,
> TK_32Bit>
> +struct test_case<FileTimeT, TimeT, TimeSpecT, Base, TK_32Bit, TK_64Bit>
>      : public Base {
>    static constexpr auto max_time_t = std::numeric_limits<TimeT>::max();
>    static constexpr auto min_time_t = std::numeric_limits<TimeT>::min();
>
> -  using Base::convert_timespec;
> +  using Base::convert_from_timespec;
>    using Base::is_representable;
>    using Base::max_nsec;
>    using Base::max_seconds;
> @@ -158,9 +249,10 @@ struct check_is_representable<FileTimeT,
>    }
>  };
>
> -template <class FileTimeT, class TimeT, class TimeSpec, class Base>
> -struct check_is_representable<FileTimeT, TimeT, TimeSpec, Base,
> -                              TK_FloatingPoint> : public Base {
> +template <class FileTimeT, class TimeT, class TimeSpec, class Base,
> +          TestKind FileTimeTKind>
> +struct test_case<FileTimeT, TimeT, TimeSpec, Base, TK_FloatingPoint,
> +                 FileTimeTKind> : public Base {
>
>    static bool test() { return true; }
>  };
> @@ -182,19 +274,33 @@ struct TestClock {
>    static time_point now() noexcept { return {}; }
>  };
>
> -template <class IntType, class Dur = duration<IntType, std::micro> >
> -using TestFileTimeT = time_point<TestClock<Dur> >;
> +template <class IntType, class Period = std::micro>
> +using TestFileTimeT = time_point<TestClock<duration<IntType, Period> > >;
>
>  int main() {
> -  assert((
> -      check_is_representable<file_time_type, time_t, struct
> timespec>::test()));
> -  assert((check_is_representable<TestFileTimeT<int64_t>, int64_t,
> -                                 TestTimeSpec<int64_t, long> >::test()));
> -  assert((check_is_representable<TestFileTimeT<long long>, int32_t,
> -                                 TestTimeSpec<int32_t, int32_t>
> >::test()));
> -
> -  // Test that insane platforms like ppc64 linux, which use long double
> as time_t,
> -  // at least compile.
> -  assert((check_is_representable<TestFileTimeT<long double>, double,
> -                                 TestTimeSpec<long double, long>
> >::test()));
> +  { assert((test_case<file_time_type, time_t, struct
> timespec>::test())); }
> +  {
> +    assert((test_case<TestFileTimeT<int64_t>, int64_t,
> +                      TestTimeSpec<int64_t, long> >::test()));
> +  }
> +  {
> +    assert((test_case<TestFileTimeT<long long>, int32_t,
> +                      TestTimeSpec<int32_t, int32_t> >::test()));
> +  }
> +  {
> +    // Test that insane platforms like ppc64 linux, which use long double
> as time_t,
> +    // at least compile.
> +    assert((test_case<TestFileTimeT<long double>, double,
> +                      TestTimeSpec<long double, long> >::test()));
> +  }
> +#ifndef TEST_HAS_NO_INT128_T
> +  {
> +    assert((test_case<TestFileTimeT<__int128_t, std::nano>, int64_t,
> +                      TestTimeSpec<int64_t, long> >::test()));
> +  }
> +  {
> +    assert((test_case<TestFileTimeT<__int128_t, std::nano>, int32_t,
> +                      TestTimeSpec<int32_t, int32_t> >::test()));
> +  }
> +#endif
>  }
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/fs.
> filesystem.synopsis/file_time_type.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.filesystem.synopsis/file_time_
> type.pass.cpp?rev=337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.
> filesystem.synopsis/file_time_type.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.
> filesystem.synopsis/file_time_type.pass.cpp Wed Jul 25 13:51:49 2018
> @@ -17,15 +17,30 @@
>  #include <chrono>
>  #include <type_traits>
>
> +#include "test_macros.h"
> +
>  // system_clock is used because it meets the requirements of TrivialClock,
>  // and the resolution and range of system_clock should match the operating
>  // system's file time type.
> -typedef std::chrono::system_clock              ExpectedClock;
> -typedef std::chrono::time_point<ExpectedClock> ExpectedTimePoint;
> +
> +void test_trivial_clock() {
> +  using namespace fs;
> +  using Clock = file_time_type::clock;
> +  ASSERT_NOEXCEPT(Clock::now());
> +  ASSERT_SAME_TYPE(decltype(Clock::now()), file_time_type);
> +  ASSERT_SAME_TYPE(Clock::time_point, file_time_type);
> +  volatile auto* odr_use = &Clock::is_steady;
> +  ((void)odr_use);
> +}
> +
> +void test_time_point_resolution_and_range() {
> +  using namespace fs;
> +  using Dur = file_time_type::duration;
> +  using Period = Dur::period;
> +  ASSERT_SAME_TYPE(Period, std::nano);
> +}
>
>  int main() {
> -  static_assert(std::is_same<
> -          fs::file_time_type,
> -          ExpectedTimePoint
> -      >::value, "");
> +  test_trivial_clock();
> +  test_time_point_resolution_and_range();
>  }
>
> Modified: libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp
> URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/
> experimental/filesystem/fs.op.funcs/fs.op.last_write_time/
> last_write_time.pass.cpp?rev=337960&r1=337959&r2=337960&view=diff
> ============================================================
> ==================
> --- libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp (original)
> +++ libcxx/trunk/test/std/experimental/filesystem/fs.op.
> funcs/fs.op.last_write_time/last_write_time.pass.cpp Wed Jul 25 13:51:49
> 2018
> @@ -30,13 +30,86 @@
>  #include <sys/stat.h>
>  #include <iostream>
>
> +#include <fcntl.h>
> +#include <sys/time.h>
> +
>  using namespace fs;
>
> -struct Times { std::time_t access, write; };
> +using TimeSpec = struct ::timespec;
> +using StatT = struct ::stat;
> +
> +using Sec = std::chrono::duration<file_time_type::rep>;
> +using Hours = std::chrono::hours;
> +using Minutes = std::chrono::minutes;
> +using MicroSec = std::chrono::duration<file_time_type::rep, std::micro>;
> +using NanoSec = std::chrono::duration<file_time_type::rep, std::nano>;
> +using std::chrono::duration_cast;
> +
> +#if defined(__APPLE__)
> +TimeSpec extract_mtime(StatT const& st) { return st.st_mtimespec; }
> +TimeSpec extract_atime(StatT const& st) { return st.st_atimespec; }
> +#else
> +TimeSpec extract_mtime(StatT const& st) { return st.st_mtim; }
> +TimeSpec extract_atime(StatT const& st) { return st.st_atim; }
> +#endif
> +
> +bool ConvertToTimeSpec(TimeSpec& ts, file_time_type ft) {
> +  using SecFieldT = decltype(TimeSpec::tv_sec);
> +  using NSecFieldT = decltype(TimeSpec::tv_nsec);
> +  using SecLim = std::numeric_limits<SecFieldT>;
> +  using NSecLim = std::numeric_limits<NSecFieldT>;
> +
> +  auto secs = duration_cast<Sec>(ft.time_since_epoch());
> +  auto nsecs = duration_cast<NanoSec>(ft.time_since_epoch() - secs);
> +  if (nsecs.count() < 0) {
> +    if (Sec::min().count() > SecLim::min()) {
> +      secs += Sec(1);
> +      nsecs -= Sec(1);
> +    } else {
> +      nsecs = NanoSec(0);
> +    }
> +  }
> +  if (SecLim::max() < secs.count() || SecLim::min() > secs.count())
> +    return false;
> +  if (NSecLim::max() < nsecs.count() || NSecLim::min() > nsecs.count())
> +    return false;
> +  ts.tv_sec = secs.count();
> +  ts.tv_nsec = nsecs.count();
> +  return true;
> +}
> +
> +bool ConvertFromTimeSpec(file_time_type& ft, TimeSpec ts) {
> +  auto secs_part = duration_cast<file_time_type::
> duration>(Sec(ts.tv_sec));
> +  if (duration_cast<Sec>(secs_part).count() != ts.tv_sec)
> +    return false;
> +  auto subsecs = duration_cast<file_time_type::
> duration>(NanoSec(ts.tv_nsec));
> +  auto dur = secs_part + subsecs;
> +  if (dur < secs_part && subsecs.count() >= 0)
> +    return false;
> +  ft = file_time_type(dur);
> +  return true;
> +}
> +
> +bool CompareTimeExact(TimeSpec ts, TimeSpec ts2) {
> +  return ts2.tv_sec == ts.tv_sec && ts2.tv_nsec == ts.tv_nsec;
> +}
> +bool CompareTimeExact(file_time_type ft, TimeSpec ts) {
> +  TimeSpec ts2 = {};
> +  if (!ConvertToTimeSpec(ts2, ft))
> +    return false;
> +  return CompareTimeExact(ts, ts2);
> +}
> +bool CompareTimeExact(TimeSpec ts, file_time_type ft) {
> +  return CompareTimeExact(ft, ts);
> +}
> +
> +struct Times {
> +  TimeSpec access, write;
> +};
>
>  Times GetTimes(path const& p) {
>      using Clock = file_time_type::clock;
> -    struct ::stat st;
> +    StatT st;
>      if (::stat(p.c_str(), &st) == -1) {
>          std::error_code ec(errno, std::generic_category());
>  #ifndef TEST_HAS_NO_EXCEPTIONS
> @@ -46,22 +119,18 @@ Times GetTimes(path const& p) {
>          std::exit(EXIT_FAILURE);
>  #endif
>      }
> -    return {st.st_atime, st.st_mtime};
> +    return {extract_atime(st), extract_mtime(st)};
>  }
>
> -std::time_t LastAccessTime(path const& p) {
> -    return GetTimes(p).access;
> -}
> +TimeSpec LastAccessTime(path const& p) { return GetTimes(p).access; }
>
> -std::time_t LastWriteTime(path const& p) {
> -    return GetTimes(p).write;
> -}
> +TimeSpec LastWriteTime(path const& p) { return GetTimes(p).write; }
>
> -std::pair<std::time_t, std::time_t> GetSymlinkTimes(path const& p) {
> -    using Clock = file_time_type::clock;
> -    struct ::stat st;
> -    if (::lstat(p.c_str(), &st) == -1) {
> -        std::error_code ec(errno, std::generic_category());
> +std::pair<TimeSpec, TimeSpec> GetSymlinkTimes(path const& p) {
> +  using Clock = file_time_type::clock;
> +  StatT st;
> +  if (::lstat(p.c_str(), &st) == -1) {
> +    std::error_code ec(errno, std::generic_category());
>  #ifndef TEST_HAS_NO_EXCEPTIONS
>          throw ec;
>  #else
> @@ -69,24 +138,10 @@ std::pair<std::time_t, std::time_t> GetS
>          std::exit(EXIT_FAILURE);
>  #endif
>      }
> -    return {st.st_atime, st.st_mtime};
> +    return {extract_atime(st), extract_mtime(st)};
>  }
>
>  namespace {
> -bool TestSupportsNegativeTimes() {
> -    using namespace std::chrono;
> -    std::error_code ec;
> -    std::time_t old_write_time, new_write_time;
> -    { // WARNING: Do not assert in this scope.
> -        scoped_test_env env;
> -        const path file = env.create_file("file", 42);
> -        old_write_time = LastWriteTime(file);
> -        file_time_type tp(seconds(-5));
> -        fs::last_write_time(file, tp, ec);
> -        new_write_time = LastWriteTime(file);
> -    }
> -    return !ec && new_write_time <= -5;
> -}
>
>  // In some configurations, the comparison is tautological and the test is
> valid.
>  // We disable the warning so that we can actually test it regardless.
> Also, that
> @@ -98,61 +153,131 @@ bool TestSupportsNegativeTimes() {
>  #pragma clang diagnostic ignored "-Wtautological-constant-compare"
>  #endif
>
> -bool TestSupportsMaxTime() {
> -    using namespace std::chrono;
> -    using Lim = std::numeric_limits<std::time_t>;
> -    auto max_sec = duration_cast<seconds>(file_
> time_type::max().time_since_epoch()).count();
> -    if (max_sec > Lim::max()) return false;
> -    std::error_code ec;
> -    std::time_t old_write_time, new_write_time;
> -    { // WARNING: Do not assert in this scope.
> -        scoped_test_env env;
> -        const path file = env.create_file("file", 42);
> -        old_write_time = LastWriteTime(file);
> -        file_time_type tp = file_time_type::max();
> -        fs::last_write_time(file, tp, ec);
> -        new_write_time = LastWriteTime(file);
> -    }
> -    return !ec && new_write_time > max_sec - 1;
> -}
> -
> -bool TestSupportsMinTime() {
> -    using namespace std::chrono;
> -    using Lim = std::numeric_limits<std::time_t>;
> -    auto min_sec = duration_cast<seconds>(file_
> time_type::min().time_since_epoch()).count();
> -    if (min_sec < Lim::min()) return false;
> -    std::error_code ec;
> -    std::time_t old_write_time, new_write_time;
> -    { // WARNING: Do not assert in this scope.
> -      scoped_test_env env;
> -      const path file = env.create_file("file", 42);
> -      old_write_time = LastWriteTime(file);
> -      file_time_type tp = file_time_type::min();
> -      fs::last_write_time(file, tp, ec);
> -      new_write_time = LastWriteTime(file);
> -    }
> -    return !ec && new_write_time < min_sec + 1;
> -}
> -
> -#if defined(__clang__)
> -#pragma clang diagnostic pop
> -#endif
> -
> -static const bool SupportsNegativeTimes = TestSupportsNegativeTimes();
> -static const bool SupportsMaxTime = TestSupportsMaxTime();
> -static const bool SupportsMinTime = TestSupportsMinTime();
> +static const bool SupportsNegativeTimes = [] {
> +  using namespace std::chrono;
> +  std::error_code ec;
> +  TimeSpec old_write_time, new_write_time;
> +  { // WARNING: Do not assert in this scope.
> +    scoped_test_env env;
> +    const path file = env.create_file("file", 42);
> +    old_write_time = LastWriteTime(file);
> +    file_time_type tp(seconds(-5));
> +    fs::last_write_time(file, tp, ec);
> +    new_write_time = LastWriteTime(file);
> +  }
> +
> +  return !ec && new_write_time.tv_sec < 0;
> +}();
> +
> +static const bool SupportsMaxTime = [] {
> +  using namespace std::chrono;
> +  TimeSpec max_ts = {};
> +  if (!ConvertToTimeSpec(max_ts, file_time_type::max()))
> +    return false;
> +
> +  std::error_code ec;
> +  TimeSpec old_write_time, new_write_time;
> +  { // WARNING: Do not assert in this scope.
> +    scoped_test_env env;
> +    const path file = env.create_file("file", 42);
> +    old_write_time = LastWriteTime(file);
> +    file_time_type tp = file_time_type::max();
> +    fs::last_write_time(file, tp, ec);
> +    new_write_time = LastWriteTime(file);
> +  }
> +  return !ec && new_write_time.tv_sec > max_ts.tv_sec - 1;
> +}();
> +
> +static const bool SupportsMinTime = [] {
> +  using namespace std::chrono;
> +  TimeSpec min_ts = {};
> +  if (!ConvertToTimeSpec(min_ts, file_time_type::min()))
> +    return false;
> +  std::error_code ec;
> +  TimeSpec old_write_time, new_write_time;
> +  { // WARNING: Do not assert in this scope.
> +    scoped_test_env env;
> +    const path file = env.create_file("file", 42);
> +    old_write_time = LastWriteTime(file);
> +    file_time_type tp = file_time_type::min();
> +    fs::last_write_time(file, tp, ec);
> +    new_write_time = LastWriteTime(file);
> +  }
> +  return !ec && new_write_time.tv_sec < min_ts.tv_sec + 1;
> +}();
> +
> +static const bool SupportsNanosecondRoundTrip = [] {
> +  NanoSec ns(3);
> +
> +  // Test if the file_time_type period is less than that of nanoseconds.
> +  auto ft_dur = duration_cast<file_time_type::duration>(ns);
> +  if (duration_cast<NanoSec>(ft_dur) != ns)
> +    return false;
> +
> +  // Test that the system call we use to set the times also supports
> nanosecond
> +  // resolution. (utimes does not)
> +  file_time_type ft(ft_dur);
> +  {
> +    scoped_test_env env;
> +    const path p = env.create_file("file", 42);
> +    last_write_time(p, ft);
> +    return last_write_time(p) == ft;
> +  }
> +}();
> +
> +static const bool SupportsMinRoundTrip = [] {
> +  TimeSpec ts = {};
> +  if (!ConvertToTimeSpec(ts, file_time_type::min()))
> +    return false;
> +  file_time_type min_val = {};
> +  if (!ConvertFromTimeSpec(min_val, ts))
> +    return false;
> +  return min_val == file_time_type::min();
> +}();
>
>  } // end namespace
>
> -// In some configurations, the comparison is tautological and the test is
> valid.
> -// We disable the warning so that we can actually test it regardless.
> Also, that
> -// diagnostic is pretty new, so also don't fail if old clang does not
> support it
> -#if defined(__clang__)
> -#pragma clang diagnostic push
> -#pragma clang diagnostic ignored "-Wunknown-warning-option"
> -#pragma clang diagnostic ignored "-Wunknown-pragmas"
> -#pragma clang diagnostic ignored "-Wtautological-constant-compare"
> -#endif
> +static bool CompareTime(TimeSpec t1, TimeSpec t2) {
> +  if (SupportsNanosecondRoundTrip)
> +    return CompareTimeExact(t1, t2);
> +  if (t1.tv_sec != t2.tv_sec)
> +    return false;
> +
> +  auto diff = std::abs(t1.tv_nsec - t2.tv_nsec);
> +
> +  return diff < duration_cast<NanoSec>(MicroSec(1)).count();
> +}
> +
> +static bool CompareTime(file_time_type t1, TimeSpec t2) {
> +  TimeSpec ts1 = {};
> +  if (!ConvertToTimeSpec(ts1, t1))
> +    return false;
> +  return CompareTime(ts1, t2);
> +}
> +
> +static bool CompareTime(TimeSpec t1, file_time_type t2) {
> +  return CompareTime(t2, t1);
> +}
> +
> +static bool CompareTime(file_time_type t1, file_time_type t2) {
> +  auto min_secs = duration_cast<Sec>(file_time_
> type::min().time_since_epoch());
> +  bool IsMin =
> +      t1.time_since_epoch() < min_secs || t2.time_since_epoch() <
> min_secs;
> +
> +  if (SupportsNanosecondRoundTrip && (!IsMin || SupportsMinRoundTrip))
> +    return t1 == t2;
> +  if (IsMin) {
> +    return duration_cast<Sec>(t1.time_since_epoch()) ==
> +           duration_cast<Sec>(t2.time_since_epoch());
> +  }
> +  file_time_type::duration dur;
> +  if (t1 > t2)
> +    dur = t1 - t2;
> +  else
> +    dur = t2 - t1;
> +
> +  return duration_cast<MicroSec>(dur).count() < 1;
> +}
>
>  // Check if a time point is representable on a given filesystem. Check
> that:
>  // (A) 'tp' is representable as a time_t
> @@ -162,22 +287,33 @@ static const bool SupportsMinTime = Test
>  // (D) 'tp' is not 'file_time_type::min()' or the filesystem supports the
> min
>  //     value.
>  inline bool TimeIsRepresentableByFilesystem(file_time_type tp) {
> -    using namespace std::chrono;
> -    using Lim = std::numeric_limits<std::time_t>;
> -    auto sec = duration_cast<seconds>(tp.time_since_epoch()).count();
> -    auto microsec = duration_cast<microseconds>(
> tp.time_since_epoch()).count();
> -    if (sec < Lim::min() || sec > Lim::max())   return false;
> -    else if (microsec < 0 && !SupportsNegativeTimes) return false;
> -    else if (tp == file_time_type::max() && !SupportsMaxTime) return
> false;
> -    else if (tp == file_time_type::min() && !SupportsMinTime) return
> false;
> -    return true;
> +  TimeSpec ts = {};
> +  if (!ConvertToTimeSpec(ts, tp))
> +    return false;
> +  else if (tp.time_since_epoch().count() < 0 && !SupportsNegativeTimes)
> +    return false;
> +  else if (tp == file_time_type::max() && !SupportsMaxTime)
> +    return false;
> +  else if (tp == file_time_type::min() && !SupportsMinTime)
> +    return false;
> +  return true;
>  }
>
>  #if defined(__clang__)
>  #pragma clang diagnostic pop
>  #endif
>
> -TEST_SUITE(exists_test_suite)
> +// Create a sub-second duration using the smallest period the filesystem
> supports.
> +file_time_type::duration SubSec(long long val) {
> +  using SubSecT = file_time_type::duration;
> +  if (SupportsNanosecondRoundTrip) {
> +    return duration_cast<SubSecT>(NanoSec(val));
> +  } else {
> +    return duration_cast<SubSecT>(MicroSec(val));
> +  }
> +}
> +
> +TEST_SUITE(last_write_time_test_suite)
>
>  TEST_CASE(signature_test)
>  {
> @@ -202,21 +338,21 @@ TEST_CASE(read_last_write_time_static_en
>          file_time_type ret = last_write_time(StaticEnv::File);
>          TEST_CHECK(ret != min);
>          TEST_CHECK(ret < C::now());
> -        TEST_CHECK(C::to_time_t(ret) == LastWriteTime(StaticEnv::File));
> +        TEST_CHECK(CompareTime(ret, LastWriteTime(StaticEnv::File)));
>
>          file_time_type ret2 = last_write_time(StaticEnv::SymlinkToFile);
> -        TEST_CHECK(ret == ret2);
> -        TEST_CHECK(C::to_time_t(ret2) == LastWriteTime(StaticEnv::
> SymlinkToFile));
> +        TEST_CHECK(CompareTime(ret, ret2));
> +        TEST_CHECK(CompareTime(ret2, LastWriteTime(StaticEnv::
> SymlinkToFile)));
>      }
>      {
>          file_time_type ret = last_write_time(StaticEnv::Dir);
>          TEST_CHECK(ret != min);
>          TEST_CHECK(ret < C::now());
> -        TEST_CHECK(C::to_time_t(ret) == LastWriteTime(StaticEnv::Dir));
> +        TEST_CHECK(CompareTime(ret, LastWriteTime(StaticEnv::Dir)));
>
>          file_time_type ret2 = last_write_time(StaticEnv::SymlinkToDir);
> -        TEST_CHECK(ret == ret2);
> -        TEST_CHECK(C::to_time_t(ret2) == LastWriteTime(StaticEnv::
> SymlinkToDir));
> +        TEST_CHECK(CompareTime(ret, ret2));
> +        TEST_CHECK(CompareTime(ret2, LastWriteTime(StaticEnv::
> SymlinkToDir)));
>      }
>  }
>
> @@ -230,15 +366,17 @@ TEST_CASE(get_last_write_time_dynamic_en
>      const path dir = env.create_dir("dir");
>
>      const auto file_times = GetTimes(file);
> -    const std::time_t file_write_time = file_times.write;
> +    const TimeSpec file_write_time = file_times.write;
>      const auto dir_times = GetTimes(dir);
> -    const std::time_t dir_write_time = dir_times.write;
> +    const TimeSpec dir_write_time = dir_times.write;
>
>      file_time_type ftime = last_write_time(file);
> -    TEST_CHECK(Clock::to_time_t(ftime) == file_write_time);
> +    TEST_CHECK(Clock::to_time_t(ftime) == file_write_time.tv_sec);
> +    TEST_CHECK(CompareTime(ftime, file_write_time));
>
>      file_time_type dtime = last_write_time(dir);
> -    TEST_CHECK(Clock::to_time_t(dtime) == dir_write_time);
> +    TEST_CHECK(Clock::to_time_t(dtime) == dir_write_time.tv_sec);
> +    TEST_CHECK(CompareTime(dtime, dir_write_time));
>
>      SleepFor(Sec(2));
>
> @@ -253,18 +391,15 @@ TEST_CASE(get_last_write_time_dynamic_en
>
>      TEST_CHECK(ftime2 > ftime);
>      TEST_CHECK(dtime2 > dtime);
> -    TEST_CHECK(LastWriteTime(file) == Clock::to_time_t(ftime2));
> -    TEST_CHECK(LastWriteTime(dir) == Clock::to_time_t(dtime2));
> +    TEST_CHECK(CompareTime(LastWriteTime(file), ftime2));
> +    TEST_CHECK(CompareTime(LastWriteTime(dir), dtime2));
>  }
>
>
>  TEST_CASE(set_last_write_time_dynamic_env_test)
>  {
>      using Clock = file_time_type::clock;
> -    using Sec = std::chrono::seconds;
> -    using Hours = std::chrono::hours;
> -    using Minutes = std::chrono::minutes;
> -    using MicroSec = std::chrono::microseconds;
> +    using SubSecT = file_time_type::duration;
>      scoped_test_env env;
>
>      const path file = env.create_file("file", 42);
> @@ -272,15 +407,17 @@ TEST_CASE(set_last_write_time_dynamic_en
>      const auto now = Clock::now();
>      const file_time_type epoch_time = now - now.time_since_epoch();
>
> -    const file_time_type future_time = now + Hours(3) + Sec(42) +
> MicroSec(17);
> -    const file_time_type past_time = now - Minutes(3) - Sec(42) -
> MicroSec(17);
> -    const file_time_type before_epoch_time = epoch_time - Minutes(3) -
> Sec(42) - MicroSec(17);
> +    const file_time_type future_time = now + Hours(3) + Sec(42) +
> SubSec(17);
> +    const file_time_type past_time = now - Minutes(3) - Sec(42) -
> SubSec(17);
> +    const file_time_type before_epoch_time =
> +        epoch_time - Minutes(3) - Sec(42) - SubSec(17);
>      // FreeBSD has a bug in their utimes implementation where the time is
> not update
>      // when the number of seconds is '-1'.
>  #if defined(__FreeBSD__)
> -    const file_time_type just_before_epoch_time = epoch_time - Sec(2) -
> MicroSec(17);
> +    const file_time_type just_before_epoch_time =
> +        epoch_time - Sec(2) - SubSec(17);
>  #else
> -    const file_time_type just_before_epoch_time = epoch_time -
> MicroSec(17);
> +    const file_time_type just_before_epoch_time = epoch_time - SubSec(17);
>  #endif
>
>      struct TestCase {
> @@ -300,7 +437,8 @@ TEST_CASE(set_last_write_time_dynamic_en
>      };
>      for (const auto& TC : cases) {
>          const auto old_times = GetTimes(TC.p);
> -        file_time_type old_time(Sec(old_times.write));
> +        file_time_type old_time;
> +        TEST_REQUIRE(ConvertFromTimeSpec(old_time, old_times.write));
>
>          std::error_code ec = GetTestEC();
>          last_write_time(TC.p, TC.new_time, ec);
> @@ -310,14 +448,8 @@ TEST_CASE(set_last_write_time_dynamic_en
>
>          if (TimeIsRepresentableByFilesystem(TC.new_time)) {
>              TEST_CHECK(got_time != old_time);
> -            if (TC.new_time < epoch_time) {
> -                TEST_CHECK(got_time <= TC.new_time);
> -                TEST_CHECK(got_time > TC.new_time - Sec(1));
> -            } else {
> -                TEST_CHECK(got_time <= TC.new_time + Sec(1));
> -                TEST_CHECK(got_time >= TC.new_time - Sec(1));
> -            }
> -            TEST_CHECK(LastAccessTime(TC.p) == old_times.access);
> +            TEST_CHECK(CompareTime(got_time, TC.new_time));
> +            TEST_CHECK(CompareTime(LastAccessTime(TC.p),
> old_times.access));
>          }
>      }
>  }
> @@ -325,9 +457,6 @@ TEST_CASE(set_last_write_time_dynamic_en
>  TEST_CASE(last_write_time_symlink_test)
>  {
>      using Clock = file_time_type::clock;
> -    using Sec = std::chrono::seconds;
> -    using Hours = std::chrono::hours;
> -    using Minutes = std::chrono::minutes;
>
>      scoped_test_env env;
>
> @@ -343,77 +472,75 @@ TEST_CASE(last_write_time_symlink_test)
>      last_write_time(sym, new_time, ec);
>      TEST_CHECK(!ec);
>
> -    const std::time_t new_time_t = Clock::to_time_t(new_time);
>      file_time_type  got_time = last_write_time(sym);
> -    std::time_t got_time_t = Clock::to_time_t(got_time);
> +    TEST_CHECK(!CompareTime(got_time, old_times.write));
> +    TEST_CHECK(got_time == new_time);
>
> -    TEST_CHECK(got_time_t != old_times.write);
> -    TEST_CHECK(got_time_t == new_time_t);
> -    TEST_CHECK(LastWriteTime(file) == new_time_t);
> -    TEST_CHECK(LastAccessTime(sym) == old_times.access);
> -    TEST_CHECK(GetSymlinkTimes(sym) == old_sym_times);
> +    TEST_CHECK(CompareTime(LastWriteTime(file), new_time));
> +    TEST_CHECK(CompareTime(LastAccessTime(sym), old_times.access));
> +    std::pair<TimeSpec, TimeSpec> sym_times = GetSymlinkTimes(sym);
> +    TEST_CHECK(CompareTime(sym_times.first, old_sym_times.first));
> +    TEST_CHECK(CompareTime(sym_times.second, old_sym_times.second));
>  }
>
>
>  TEST_CASE(test_write_min_time)
>  {
>      using Clock = file_time_type::clock;
> -    using Sec = std::chrono::seconds;
> -    using MicroSec = std::chrono::microseconds;
> -    using Lim = std::numeric_limits<std::time_t>;
>      scoped_test_env env;
>      const path p = env.create_file("file", 42);
> -
> -    std::error_code ec = GetTestEC();
> +    const file_time_type old_time = last_write_time(p);
>      file_time_type new_time = file_time_type::min();
>
> +    std::error_code ec = GetTestEC();
>      last_write_time(p, new_time, ec);
>      file_time_type tt = last_write_time(p);
>
>      if (TimeIsRepresentableByFilesystem(new_time)) {
>          TEST_CHECK(!ec);
> -        TEST_CHECK(tt >= new_time);
> -        TEST_CHECK(tt < new_time + Sec(1));
> -
> -        ec = GetTestEC();
> -        last_write_time(p, Clock::now());
> +        TEST_CHECK(CompareTime(tt, new_time));
>
> -        new_time = file_time_type::min() + MicroSec(1);
> +        last_write_time(p, old_time);
> +        new_time = file_time_type::min() + SubSec(1);
>
> +        ec = GetTestEC();
>          last_write_time(p, new_time, ec);
>          tt = last_write_time(p);
>
>          if (TimeIsRepresentableByFilesystem(new_time)) {
>              TEST_CHECK(!ec);
> -            TEST_CHECK(tt >= new_time);
> -            TEST_CHECK(tt < new_time + Sec(1));
> +            TEST_CHECK(CompareTime(tt, new_time));
> +        } else {
> +          TEST_CHECK(ErrorIs(ec, std::errc::value_too_large));
> +          TEST_CHECK(tt == old_time);
>          }
> +    } else {
> +      TEST_CHECK(ErrorIs(ec, std::errc::value_too_large));
> +      TEST_CHECK(tt == old_time);
>      }
>  }
>
> +TEST_CASE(test_write_max_time) {
> +  using Clock = file_time_type::clock;
> +  using Sec = std::chrono::seconds;
> +  using Hours = std::chrono::hours;
> +
> +  scoped_test_env env;
> +  const path p = env.create_file("file", 42);
> +  const file_time_type old_time = last_write_time(p);
> +  file_time_type new_time = file_time_type::max();
> +
> +  std::error_code ec = GetTestEC();
> +  last_write_time(p, new_time, ec);
> +  file_time_type tt = last_write_time(p);
>
> -
> -TEST_CASE(test_write_min_max_time)
> -{
> -    using Clock = file_time_type::clock;
> -    using Sec = std::chrono::seconds;
> -    using Hours = std::chrono::hours;
> -    using Lim = std::numeric_limits<std::time_t>;
> -    scoped_test_env env;
> -    const path p = env.create_file("file", 42);
> -
> -    std::error_code ec = GetTestEC();
> -    file_time_type new_time = file_time_type::max();
> -
> -    ec = GetTestEC();
> -    last_write_time(p, new_time, ec);
> -    file_time_type tt = last_write_time(p);
> -
> -    if (TimeIsRepresentableByFilesystem(new_time)) {
> -        TEST_CHECK(!ec);
> -        TEST_CHECK(tt > new_time - Sec(1));
> -        TEST_CHECK(tt <= new_time);
> -    }
> +  if (TimeIsRepresentableByFilesystem(new_time)) {
> +    TEST_CHECK(!ec);
> +    TEST_CHECK(CompareTime(tt, new_time));
> +  } else {
> +    TEST_CHECK(ErrorIs(ec, std::errc::value_too_large));
> +    TEST_CHECK(tt == old_time);
> +  }
>  }
>
>  TEST_CASE(test_value_on_failure)
> @@ -421,8 +548,7 @@ TEST_CASE(test_value_on_failure)
>      const path p = StaticEnv::DNE;
>      std::error_code ec = GetTestEC();
>      TEST_CHECK(last_write_time(p, ec) == file_time_type::min());
> -    TEST_CHECK(ec);
> -    TEST_CHECK(ec != GetTestEC());
> +    TEST_CHECK(ErrorIs(ec, std::errc::no_such_file_or_directory));
>  }
>
>  TEST_CASE(test_exists_fails)
> @@ -434,10 +560,30 @@ TEST_CASE(test_exists_fails)
>
>      std::error_code ec = GetTestEC();
>      TEST_CHECK(last_write_time(file, ec) == file_time_type::min());
> -    TEST_CHECK(ec);
> -    TEST_CHECK(ec != GetTestEC());
> +    TEST_CHECK(ErrorIs(ec, std::errc::permission_denied));
>
> -    TEST_CHECK_THROW(filesystem_error, last_write_time(file));
> +    ExceptionChecker Checker(file, std::errc::permission_denied,
> +                             "last_write_time");
> +    TEST_CHECK_THROW_RESULT(filesystem_error, Checker,
> last_write_time(file));
> +}
> +
> +TEST_CASE(my_test) {
> +  scoped_test_env env;
> +  const path p = env.create_file("file", 42);
> +  using namespace std::chrono;
> +  using TimeSpec = struct ::timespec;
> +  TimeSpec ts[2];
> +  ts[0].tv_sec = 0;
> +  ts[0].tv_nsec = UTIME_OMIT;
> +  ts[1].tv_sec = -1;
> +  ts[1].tv_nsec =
> +      duration_cast<nanoseconds>(seconds(1) - nanoseconds(13)).count();
> +  if (::utimensat(AT_FDCWD, p.c_str(), ts, 0) == -1) {
> +    TEST_CHECK(false);
> +  }
> +  TimeSpec new_ts = LastWriteTime(p);
> +  TEST_CHECK(ts[1].tv_sec == new_ts.tv_sec);
> +  TEST_CHECK(ts[1].tv_nsec == new_ts.tv_nsec);
>  }
>
>  TEST_SUITE_END()
>
>
> _______________________________________________
> cfe-commits mailing list
> cfe-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
>
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