Add libcxx filesystem modules

Makefile

@@ -142,13 +142,10 @@ include libc/thread/thread.mk			# │  You can finally call malloc()
 include libc/zipos/zipos.mk			# │
 include libc/stdio/stdio.mk			# │
 include libc/time/time.mk			# │
-include third_party/libcxx/libcxx.mk		# │
 include net/net.mk				# │
 include third_party/vqsort/vqsort.mk		# │
 include libc/log/log.mk				# │
 include third_party/getopt/getopt.mk		# │
-include third_party/ggml/ggml.mk		# │
-include third_party/radpajama/radpajama.mk	# │
 include third_party/bzip2/bzip2.mk		# │
 include dsp/core/core.mk			# │
 include libc/x/x.mk				# │
@@ -166,6 +163,9 @@ include dsp/tty/tty.mk				# ├──ONLINE RUNTIME
 include libc/dns/dns.mk				# │  You can communicate with the network
 include net/http/http.mk			# │
 include third_party/mbedtls/mbedtls.mk		# │
+include third_party/libcxx/libcxx.mk		# │
+include third_party/ggml/ggml.mk		# │
+include third_party/radpajama/radpajama.mk	# │
 include net/https/https.mk			# │
 include third_party/regex/regex.mk		#─┘
 include third_party/tidy/tidy.mk

build/config.mk

@@ -8,16 +8,17 @@
 #   - Backtraces
 #   - Syscall tracing
 #   - Function tracing
-#   - No GDB debugging
 #
 ifeq ($(MODE),)
 ENABLE_FTRACE = 1
+CONFIG_OFLAGS ?= -g
 CONFIG_CCFLAGS += -O2 $(BACKTRACES)
 CONFIG_CPPFLAGS += -DSYSDEBUG
 TARGET_ARCH ?= -msse3
 endif
 ifeq ($(MODE), aarch64)
 ENABLE_FTRACE = 1
+CONFIG_OFLAGS ?= -g
 CONFIG_CCFLAGS += -O2 $(BACKTRACES)
 CONFIG_CPPFLAGS += -DSYSDEBUG
 endif

third_party/libcxx/directory_iterator.cc

@@ -0,0 +1,393 @@
+// clang-format off
+//===------------------ directory_iterator.cpp ----------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "third_party/libcxx/filesystem"
+#include "third_party/libcxx/__config"
+#include "libc/calls/struct/dirent.h"
+#include "libc/sysv/consts/dt.h"
+#include "third_party/libcxx/filesystem_common.hh"
+
+_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
+
+namespace detail {
+namespace {
+
+#if !defined(_LIBCPP_WIN32API)
+
+#if defined(DT_BLK)
+template <class DirEntT, class = decltype(DirEntT::d_type)>
+static file_type get_file_type(DirEntT* ent, int) {
+  switch (ent->d_type) {
+  case DT_BLK:
+    return file_type::block;
+  case DT_CHR:
+    return file_type::character;
+  case DT_DIR:
+    return file_type::directory;
+  case DT_FIFO:
+    return file_type::fifo;
+  case DT_LNK:
+    return file_type::symlink;
+  case DT_REG:
+    return file_type::regular;
+  case DT_SOCK:
+    return file_type::socket;
+  // Unlike in lstat, hitting "unknown" here simply means that the underlying
+  // filesystem doesn't support d_type. Report is as 'none' so we correctly
+  // set the cache to empty.
+  case DT_UNKNOWN:
+    break;
+  }
+  return file_type::none;
+}
+#endif // defined(DT_BLK)
+
+template <class DirEntT>
+static file_type get_file_type(DirEntT* ent, long) {
+  return file_type::none;
+}
+
+static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
+                                                  error_code& ec) {
+  struct dirent* dir_entry_ptr = nullptr;
+  errno = 0; // zero errno in order to detect errors
+  ec.clear();
+  if ((dir_entry_ptr = ::readdir(dir_stream)) == nullptr) {
+    if (errno)
+      ec = capture_errno();
+    return {};
+  } else {
+    return {dir_entry_ptr->d_name, get_file_type(dir_entry_ptr, 0)};
+  }
+}
+#else
+
+static file_type get_file_type(const WIN32_FIND_DATA& data) {
+  //auto attrs = data.dwFileAttributes;
+  // FIXME(EricWF)
+  return file_type::unknown;
+}
+static uintmax_t get_file_size(const WIN32_FIND_DATA& data) {
+  return (data.nFileSizeHigh * (MAXDWORD + 1)) + data.nFileSizeLow;
+}
+static file_time_type get_write_time(const WIN32_FIND_DATA& data) {
+  ULARGE_INTEGER tmp;
+  const FILETIME& time = data.ftLastWriteTime;
+  tmp.u.LowPart = time.dwLowDateTime;
+  tmp.u.HighPart = time.dwHighDateTime;
+  return file_time_type(file_time_type::duration(tmp.QuadPart));
+}
+
+#endif
+
+} // namespace
+} // namespace detail
+
+using detail::ErrorHandler;
+
+#if defined(_LIBCPP_WIN32API)
+class __dir_stream {
+public:
+  __dir_stream() = delete;
+  __dir_stream& operator=(const __dir_stream&) = delete;
+
+  __dir_stream(__dir_stream&& __ds) noexcept : __stream_(__ds.__stream_),
+                                               __root_(move(__ds.__root_)),
+                                               __entry_(move(__ds.__entry_)) {
+    __ds.__stream_ = INVALID_HANDLE_VALUE;
+  }
+
+  __dir_stream(const path& root, directory_options opts, error_code& ec)
+      : __stream_(INVALID_HANDLE_VALUE), __root_(root) {
+    __stream_ = ::FindFirstFile(root.c_str(), &__data_);
+    if (__stream_ == INVALID_HANDLE_VALUE) {
+      ec = error_code(::GetLastError(), generic_category());
+      const bool ignore_permission_denied =
+          bool(opts & directory_options::skip_permission_denied);
+      if (ignore_permission_denied && ec.value() == ERROR_ACCESS_DENIED)
+        ec.clear();
+      return;
+    }
+  }
+
+  ~__dir_stream() noexcept {
+    if (__stream_ == INVALID_HANDLE_VALUE)
+      return;
+    close();
+  }
+
+  bool good() const noexcept { return __stream_ != INVALID_HANDLE_VALUE; }
+
+  bool advance(error_code& ec) {
+    while (::FindNextFile(__stream_, &__data_)) {
+      if (!strcmp(__data_.cFileName, ".") || strcmp(__data_.cFileName, ".."))
+        continue;
+      // FIXME: Cache more of this
+      //directory_entry::__cached_data cdata;
+      //cdata.__type_ = get_file_type(__data_);
+      //cdata.__size_ = get_file_size(__data_);
+      //cdata.__write_time_ = get_write_time(__data_);
+      __entry_.__assign_iter_entry(
+          __root_ / __data_.cFileName,
+          directory_entry::__create_iter_result(detail::get_file_type(__data)));
+      return true;
+    }
+    ec = error_code(::GetLastError(), generic_category());
+    close();
+    return false;
+  }
+
+private:
+  error_code close() noexcept {
+    error_code ec;
+    if (!::FindClose(__stream_))
+      ec = error_code(::GetLastError(), generic_category());
+    __stream_ = INVALID_HANDLE_VALUE;
+    return ec;
+  }
+
+  HANDLE __stream_{INVALID_HANDLE_VALUE};
+  WIN32_FIND_DATA __data_;
+
+public:
+  path __root_;
+  directory_entry __entry_;
+};
+#else
+class __dir_stream {
+public:
+  __dir_stream() = delete;
+  __dir_stream& operator=(const __dir_stream&) = delete;
+
+  __dir_stream(__dir_stream&& other) noexcept : __stream_(other.__stream_),
+                                                __root_(move(other.__root_)),
+                                                __entry_(move(other.__entry_)) {
+    other.__stream_ = nullptr;
+  }
+
+  __dir_stream(const path& root, directory_options opts, error_code& ec)
+      : __stream_(nullptr), __root_(root) {
+    if ((__stream_ = ::opendir(root.c_str())) == nullptr) {
+      ec = detail::capture_errno();
+      const bool allow_eacess =
+          bool(opts & directory_options::skip_permission_denied);
+      if (allow_eacess && ec.value() == EACCES)
+        ec.clear();
+      return;
+    }
+    advance(ec);
+  }
+
+  ~__dir_stream() noexcept {
+    if (__stream_)
+      close();
+  }
+
+  bool good() const noexcept { return __stream_ != nullptr; }
+
+  bool advance(error_code& ec) {
+    while (true) {
+      auto str_type_pair = detail::posix_readdir(__stream_, ec);
+      auto& str = str_type_pair.first;
+      if (str == "." || str == "..") {
+        continue;
+      } else if (ec || str.empty()) {
+        close();
+        return false;
+      } else {
+        __entry_.__assign_iter_entry(
+            __root_ / str,
+            directory_entry::__create_iter_result(str_type_pair.second));
+        return true;
+      }
+    }
+  }
+
+private:
+  error_code close() noexcept {
+    error_code m_ec;
+    if (::closedir(__stream_) == -1)
+      m_ec = detail::capture_errno();
+    __stream_ = nullptr;
+    return m_ec;
+  }
+
+  DIR* __stream_{nullptr};
+
+public:
+  path __root_;
+  directory_entry __entry_;
+};
+#endif
+
+// directory_iterator
+
+directory_iterator::directory_iterator(const path& p, error_code* ec,
+                                       directory_options opts) {
+  ErrorHandler<void> err("directory_iterator::directory_iterator(...)", ec, &p);
+
+  error_code m_ec;
+  __imp_ = make_shared<__dir_stream>(p, opts, m_ec);
+  if (ec)
+    *ec = m_ec;
+  if (!__imp_->good()) {
+    __imp_.reset();
+    if (m_ec)
+      err.report(m_ec);
+  }
+}
+
+directory_iterator& directory_iterator::__increment(error_code* ec) {
+  _LIBCPP_ASSERT(__imp_, "Attempting to increment an invalid iterator");
+  ErrorHandler<void> err("directory_iterator::operator++()", ec);
+
+  error_code m_ec;
+  if (!__imp_->advance(m_ec)) {
+    path root = move(__imp_->__root_);
+    __imp_.reset();
+    if (m_ec)
+      err.report(m_ec, "at root \"%s\"", root);
+  }
+  return *this;
+}
+
+directory_entry const& directory_iterator::__dereference() const {
+  _LIBCPP_ASSERT(__imp_, "Attempting to dereference an invalid iterator");
+  return __imp_->__entry_;
+}
+
+// recursive_directory_iterator
+
+struct recursive_directory_iterator::__shared_imp {
+  stack<__dir_stream> __stack_;
+  directory_options __options_;
+};
+
+recursive_directory_iterator::recursive_directory_iterator(
+    const path& p, directory_options opt, error_code* ec)
+    : __imp_(nullptr), __rec_(true) {
+  ErrorHandler<void> err("recursive_directory_iterator", ec, &p);
+
+  error_code m_ec;
+  __dir_stream new_s(p, opt, m_ec);
+  if (m_ec)
+    err.report(m_ec);
+  if (m_ec || !new_s.good())
+    return;
+
+  __imp_ = make_shared<__shared_imp>();
+  __imp_->__options_ = opt;
+  __imp_->__stack_.push(move(new_s));
+}
+
+void recursive_directory_iterator::__pop(error_code* ec) {
+  _LIBCPP_ASSERT(__imp_, "Popping the end iterator");
+  if (ec)
+    ec->clear();
+  __imp_->__stack_.pop();
+  if (__imp_->__stack_.size() == 0)
+    __imp_.reset();
+  else
+    __advance(ec);
+}
+
+directory_options recursive_directory_iterator::options() const {
+  return __imp_->__options_;
+}
+
+int recursive_directory_iterator::depth() const {
+  return __imp_->__stack_.size() - 1;
+}
+
+const directory_entry& recursive_directory_iterator::__dereference() const {
+  return __imp_->__stack_.top().__entry_;
+}
+
+recursive_directory_iterator&
+recursive_directory_iterator::__increment(error_code* ec) {
+  if (ec)
+    ec->clear();
+  if (recursion_pending()) {
+    if (__try_recursion(ec) || (ec && *ec))
+      return *this;
+  }
+  __rec_ = true;
+  __advance(ec);
+  return *this;
+}
+
+void recursive_directory_iterator::__advance(error_code* ec) {
+  ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
+
+  const directory_iterator end_it;
+  auto& stack = __imp_->__stack_;
+  error_code m_ec;
+  while (stack.size() > 0) {
+    if (stack.top().advance(m_ec))
+      return;
+    if (m_ec)
+      break;
+    stack.pop();
+  }
+
+  if (m_ec) {
+    path root = move(stack.top().__root_);
+    __imp_.reset();
+    err.report(m_ec, "at root \"%s\"", root);
+  } else {
+    __imp_.reset();
+  }
+}
+
+bool recursive_directory_iterator::__try_recursion(error_code* ec) {
+  ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
+
+  bool rec_sym = bool(options() & directory_options::follow_directory_symlink);
+
+  auto& curr_it = __imp_->__stack_.top();
+
+  bool skip_rec = false;
+  error_code m_ec;
+  if (!rec_sym) {
+    file_status st(curr_it.__entry_.__get_sym_ft(&m_ec));
+    if (m_ec && status_known(st))
+      m_ec.clear();
+    if (m_ec || is_symlink(st) || !is_directory(st))
+      skip_rec = true;
+  } else {
+    file_status st(curr_it.__entry_.__get_ft(&m_ec));
+    if (m_ec && status_known(st))
+      m_ec.clear();
+    if (m_ec || !is_directory(st))
+      skip_rec = true;
+  }
+
+  if (!skip_rec) {
+    __dir_stream new_it(curr_it.__entry_.path(), __imp_->__options_, m_ec);
+    if (new_it.good()) {
+      __imp_->__stack_.push(move(new_it));
+      return true;
+    }
+  }
+  if (m_ec) {
+    const bool allow_eacess =
+        bool(__imp_->__options_ & directory_options::skip_permission_denied);
+    if (m_ec.value() == EACCES && allow_eacess) {
+      if (ec)
+        ec->clear();
+    } else {
+      path at_ent = move(curr_it.__entry_.__p_);
+      __imp_.reset();
+      err.report(m_ec, "attempting recursion into \"%s\"", at_ent);
+    }
+  }
+  return false;
+}
+
+_LIBCPP_END_NAMESPACE_FILESYSTEM

third_party/libcxx/filesystem_common.hh

@@ -0,0 +1,425 @@
+// clang-format off
+//===----------------------------------------------------------------------===////
+//
+// 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 "third_party/libcxx/__config"
+#include "third_party/libcxx/filesystem"
+#include "third_party/libcxx/filesystem_common.hh"
+#include "third_party/libcxx/array"
+#include "third_party/libcxx/chrono"
+#include "third_party/libcxx/cstdlib"
+#include "libc/calls/struct/stat.h"
+#include "libc/sysv/consts/at.h"
+#include "third_party/libcxx/climits"
+
+#define _LIBCPP_USE_UTIMENSAT
+
+#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

third_party/libcxx/libcxx.mk

@@ -75,6 +75,7 @@ THIRD_PARTY_LIBCXX_A_HDRS =					\
 	third_party/libcxx/execution				\
 	third_party/libcxx/experimental/__config		\
 	third_party/libcxx/filesystem				\
+	third_party/libcxx/filesystem_common.hh			\
 	third_party/libcxx/forward_list				\
 	third_party/libcxx/fstream				\
 	third_party/libcxx/functional				\
@@ -144,6 +145,7 @@ THIRD_PARTY_LIBCXX_A_SRCS_CC =					\
 	third_party/libcxx/chrono.cc				\
 	third_party/libcxx/condition_variable.cc		\
 	third_party/libcxx/condition_variable_destructor.cc	\
+	third_party/libcxx/directory_iterator.cc		\
 	third_party/libcxx/exception.cc				\
 	third_party/libcxx/functional.cc			\
 	third_party/libcxx/future.cc				\
@@ -157,6 +159,7 @@ THIRD_PARTY_LIBCXX_A_SRCS_CC =					\
 	third_party/libcxx/memory.cc				\
 	third_party/libcxx/mutex.cc				\
 	third_party/libcxx/new.cc				\
+	third_party/libcxx/operations.cc			\
 	third_party/libcxx/optional.cc				\
 	third_party/libcxx/random.cc				\
 	third_party/libcxx/regex.cc				\
@@ -188,6 +191,7 @@ THIRD_PARTY_LIBCXX_A_DIRECTDEPS =				\
 	LIBC_NEXGEN32E						\
 	LIBC_RUNTIME						\
 	LIBC_STDIO						\
+	LIBC_SOCK						\
 	LIBC_STR						\
 	LIBC_SYSV						\
 	LIBC_TIME						\