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

Eric Fiselier via cfe-commits cfe-commits at lists.llvm.org
Wed Jul 25 14:27:02 PDT 2018


Thanks. let me know if you want me to take over

On Wed, Jul 25, 2018, 3:22 PM Alex L, <arphaman at gmail.com> wrote:

>
>
> 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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