Import libc++ 10.0.1 release.

1 files changed, 435 insertions, 0 deletions

diff --git a/gnu/llvm/libcxx/src/filesystem/filesystem_common.h b/gnu/llvm/libcxx/src/filesystem/filesystem_common.h
new file mode 100644
index 00000000000..fe5c42f5e6d
--- /dev/null
+++ b/gnu/llvm/libcxx/src/filesystem/filesystem_common.h
@@ -0,0 +1,435 @@
+//===----------------------------------------------------------------------===////
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===////
+
+#ifndef FILESYSTEM_COMMON_H
+#define FILESYSTEM_COMMON_H
+
+#include "__config"
+#include "filesystem"
+#include "array"
+#include "chrono"
+#include "cstdlib"
+#include "climits"
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <sys/time.h> // for ::utimes as used in __last_write_time
+#include <fcntl.h>    /* values for fchmodat */
+
+#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 _LIBCPP_USE_UTIMENSAT
+#endif
+#endif
+
+#if defined(__GNUC__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
+
+namespace detail {
+namespace {
+
+static string format_string_imp(const char* msg, ...) {
+  // we might need a second shot at this, so pre-emptivly make a copy
+  struct GuardVAList {
+    va_list& target;
+    bool active = true;
+    GuardVAList(va_list& target) : target(target), active(true) {}
+    void clear() {
+      if (active)
+        va_end(target);
+      active = false;
+    }
+    ~GuardVAList() {
+      if (active)
+        va_end(target);
+    }
+  };
+  va_list args;
+  va_start(args, msg);
+  GuardVAList args_guard(args);
+
+  va_list args_cp;
+  va_copy(args_cp, args);
+  GuardVAList args_copy_guard(args_cp);
+
+  std::string result;
+
+  array<char, 256> local_buff;
+  size_t size_with_null = local_buff.size();
+  auto ret = ::vsnprintf(local_buff.data(), size_with_null, msg, args_cp);
+
+  args_copy_guard.clear();
+
+  // handle empty expansion
+  if (ret == 0)
+    return result;
+  if (static_cast<size_t>(ret) < size_with_null) {
+    result.assign(local_buff.data(), static_cast<size_t>(ret));
+    return result;
+  }
+
+  // we did not provide a long enough buffer on our first attempt. The
+  // return value is the number of bytes (excluding the null byte) that are
+  // needed for formatting.
+  size_with_null = static_cast<size_t>(ret) + 1;
+  result.__resize_default_init(size_with_null - 1);
+  ret = ::vsnprintf(&result[0], size_with_null, msg, args);
+  _LIBCPP_ASSERT(static_cast<size_t>(ret) == (size_with_null - 1), "TODO");
+
+  return result;
+}
+
+const char* unwrap(string const& s) { return s.c_str(); }
+const char* unwrap(path const& p) { return p.native().c_str(); }
+template <class Arg>
+Arg const& unwrap(Arg const& a) {
+  static_assert(!is_class<Arg>::value, "cannot pass class here");
+  return a;
+}
+
+template <class... Args>
+string format_string(const char* fmt, Args const&... args) {
+  return format_string_imp(fmt, unwrap(args)...);
+}
+
+error_code capture_errno() {
+  _LIBCPP_ASSERT(errno, "Expected errno to be non-zero");
+  return error_code(errno, generic_category());
+}
+
+template <class T>
+T error_value();
+template <>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 void error_value<void>() {}
+template <>
+bool error_value<bool>() {
+  return false;
+}
+template <>
+uintmax_t error_value<uintmax_t>() {
+  return uintmax_t(-1);
+}
+template <>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 file_time_type error_value<file_time_type>() {
+  return file_time_type::min();
+}
+template <>
+path error_value<path>() {
+  return {};
+}
+
+template <class T>
+struct ErrorHandler {
+  const char* func_name;
+  error_code* ec = nullptr;
+  const path* p1 = nullptr;
+  const path* p2 = nullptr;
+
+  ErrorHandler(const char* fname, error_code* ec, const path* p1 = nullptr,
+               const path* p2 = nullptr)
+      : func_name(fname), ec(ec), p1(p1), p2(p2) {
+    if (ec)
+      ec->clear();
+  }
+
+  T report(const error_code& m_ec) const {
+    if (ec) {
+      *ec = m_ec;
+      return error_value<T>();
+    }
+    string what = string("in ") + func_name;
+    switch (bool(p1) + bool(p2)) {
+    case 0:
+      __throw_filesystem_error(what, m_ec);
+    case 1:
+      __throw_filesystem_error(what, *p1, m_ec);
+    case 2:
+      __throw_filesystem_error(what, *p1, *p2, m_ec);
+    }
+    _LIBCPP_UNREACHABLE();
+  }
+
+  template <class... Args>
+  T report(const error_code& m_ec, const char* msg, Args const&... args) const {
+    if (ec) {
+      *ec = m_ec;
+      return error_value<T>();
+    }
+    string what =
+        string("in ") + func_name + ": " + format_string(msg, args...);
+    switch (bool(p1) + bool(p2)) {
+    case 0:
+      __throw_filesystem_error(what, m_ec);
+    case 1:
+      __throw_filesystem_error(what, *p1, m_ec);
+    case 2:
+      __throw_filesystem_error(what, *p1, *p2, m_ec);
+    }
+    _LIBCPP_UNREACHABLE();
+  }
+
+  T report(errc const& err) const { return report(make_error_code(err)); }
+
+  template <class... Args>
+  T report(errc const& err, const char* msg, Args const&... args) const {
+    return report(make_error_code(err), msg, args...);
+  }
+
+private:
+  ErrorHandler(ErrorHandler const&) = delete;
+  ErrorHandler& operator=(ErrorHandler const&) = delete;
+};
+
+using chrono::duration;
+using chrono::duration_cast;
+
+using TimeSpec = struct ::timespec;
+using StatT = struct ::stat;
+
+template <class FileTimeT, class TimeT,
+          bool IsFloat = is_floating_point<typename FileTimeT::rep>::value>
+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 rep min_seconds =
+      duration_cast<fs_seconds>(FileTimeT::duration::min()).count();
+
+  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 && !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
+  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(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, 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, 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, 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 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 _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;
+    *out = static_cast<CType>(time);
+    return true;
+  }
+
+  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool is_representable(TimeSpecT tm) {
+    if (tm.tv_sec >= 0) {
+      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;
+    }
+  }
+
+  static _LIBCPP_CONSTEXPR_AFTER_CXX11 bool is_representable(FileTimeT tm) {
+    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 + fs_seconds(1);
+      nsecs = nsecs + fs_seconds(1);
+    }
+    using TLim = numeric_limits<TimeT>;
+    if (secs.count() >= 0)
+      return secs.count() <= TLim::max();
+    return secs.count() >= TLim::min();
+  }
+
+  static _LIBCPP_CONSTEXPR_AFTER_CXX11 FileTimeT
+  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<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 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<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 = sec_dur - fs_seconds(1);
+        subsec_dur = subsec_dur + fs_seconds(1);
+      } else {
+        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);
+  }
+};
+
+using fs_time = time_util<file_time_type, time_t, TimeSpec>;
+
+#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
+
+// allow the utimes implementation to compile even it we're not going
+// to use it.
+
+bool posix_utimes(const path& p, std::array<TimeSpec, 2> const& TS,
+                  error_code& ec) {
+  using namespace chrono;
+  auto Convert = [](long nsec) {
+    using int_type = decltype(std::declval< ::timeval>().tv_usec);
+    auto dur = duration_cast<microseconds>(nanoseconds(nsec)).count();
+    return static_cast<int_type>(dur);
+  };
+  struct ::timeval ConvertedTS[2] = {{TS[0].tv_sec, Convert(TS[0].tv_nsec)},
+                                     {TS[1].tv_sec, Convert(TS[1].tv_nsec)}};
+  if (::utimes(p.c_str(), ConvertedTS) == -1) {
+    ec = capture_errno();
+    return true;
+  }
+  return false;
+}
+
+#if defined(_LIBCPP_USE_UTIMENSAT)
+bool posix_utimensat(const path& p, std::array<TimeSpec, 2> const& TS,
+                     error_code& ec) {
+  if (::utimensat(AT_FDCWD, p.c_str(), TS.data(), 0) == -1) {
+    ec = capture_errno();
+    return true;
+  }
+  return false;
+}
+#endif
+
+bool set_file_times(const path& p, std::array<TimeSpec, 2> const& TS,
+                    error_code& ec) {
+#if !defined(_LIBCPP_USE_UTIMENSAT)
+  return posix_utimes(p, TS, ec);
+#else
+  return posix_utimensat(p, TS, ec);
+#endif
+}
+
+} // namespace
+} // end namespace detail
+
+_LIBCPP_END_NAMESPACE_FILESYSTEM
+
+#endif // FILESYSTEM_COMMON_H