Implement <filesystem>
This patch implements the <filesystem> header and uses that
to provide <experimental/filesystem>.
Unlike other standard headers, the symbols needed for <filesystem>
have not yet been placed in libc++.so. Instead they live in the
new libc++fs.a library. Users of filesystem are required to link this
library. (Also note that libc++experimental no longer contains the
definition of <experimental/filesystem>, which now requires linking libc++fs).
The reason for keeping <filesystem> out of the dylib for now is that
it's still somewhat experimental, and the possibility of requiring an
ABI breaking change is very real. In the future the symbols will likely
be moved into the dylib, or the dylib will be made to link libc++fs automagically).
Note that moving the symbols out of libc++experimental may break user builds
until they update to -lc++fs. This should be OK, because the experimental
library provides no stability guarantees. However, I plan on looking into
ways we can force libc++experimental to automagically link libc++fs.
In order to use a single implementation and set of tests for <filesystem>, it
has been placed in a special `__fs` namespace. This namespace is inline in
C++17 onward, but not before that. As such implementation is available
in C++11 onward, but no filesystem namespace is present "directly", and
as such name conflicts shouldn't occur in C++11 or C++14.
llvm-svn: 338093
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 998a5c88312066fcc2b2de1358edc76587611354
diff --git a/src/filesystem/operations.cpp b/src/filesystem/operations.cpp
new file mode 100644
index 0000000..65a4b31
--- /dev/null
+++ b/src/filesystem/operations.cpp
@@ -0,0 +1,1686 @@
+//===--------------------- filesystem/ops.cpp -----------------------------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "filesystem"
+#include "array"
+#include "iterator"
+#include "fstream"
+#include "random" /* for unique_path */
+#include "string_view"
+#include "type_traits"
+#include "vector"
+#include "cstdlib"
+#include "climits"
+
+#include "filesystem_common.h"
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <time.h>
+#include <fcntl.h> /* values for fchmodat */
+
+#if defined(__linux__)
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 33)
+#include <sys/sendfile.h>
+#define _LIBCPP_USE_SENDFILE
+#endif
+#elif defined(__APPLE__) || __has_include(<copyfile.h>)
+#include <copyfile.h>
+#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"
+#endif
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
+
+namespace {
+namespace parser {
+
+using string_view_t = path::__string_view;
+using string_view_pair = pair<string_view_t, string_view_t>;
+using PosPtr = path::value_type const*;
+
+struct PathParser {
+ enum ParserState : unsigned char {
+ // Zero is a special sentinel value used by default constructed iterators.
+ PS_BeforeBegin = path::iterator::_BeforeBegin,
+ PS_InRootName = path::iterator::_InRootName,
+ PS_InRootDir = path::iterator::_InRootDir,
+ PS_InFilenames = path::iterator::_InFilenames,
+ PS_InTrailingSep = path::iterator::_InTrailingSep,
+ PS_AtEnd = path::iterator::_AtEnd
+ };
+
+ const string_view_t Path;
+ string_view_t RawEntry;
+ ParserState State;
+
+private:
+ PathParser(string_view_t P, ParserState State) noexcept : Path(P),
+ State(State) {}
+
+public:
+ PathParser(string_view_t P, string_view_t E, unsigned char S)
+ : Path(P), RawEntry(E), State(static_cast<ParserState>(S)) {
+ // S cannot be '0' or PS_BeforeBegin.
+ }
+
+ static PathParser CreateBegin(string_view_t P) noexcept {
+ PathParser PP(P, PS_BeforeBegin);
+ PP.increment();
+ return PP;
+ }
+
+ static PathParser CreateEnd(string_view_t P) noexcept {
+ PathParser PP(P, PS_AtEnd);
+ return PP;
+ }
+
+ PosPtr peek() const noexcept {
+ auto TkEnd = getNextTokenStartPos();
+ auto End = getAfterBack();
+ return TkEnd == End ? nullptr : TkEnd;
+ }
+
+ void increment() noexcept {
+ const PosPtr End = getAfterBack();
+ const PosPtr Start = getNextTokenStartPos();
+ if (Start == End)
+ return makeState(PS_AtEnd);
+
+ switch (State) {
+ case PS_BeforeBegin: {
+ PosPtr TkEnd = consumeSeparator(Start, End);
+ if (TkEnd)
+ return makeState(PS_InRootDir, Start, TkEnd);
+ else
+ return makeState(PS_InFilenames, Start, consumeName(Start, End));
+ }
+ case PS_InRootDir:
+ return makeState(PS_InFilenames, Start, consumeName(Start, End));
+
+ case PS_InFilenames: {
+ PosPtr SepEnd = consumeSeparator(Start, End);
+ if (SepEnd != End) {
+ PosPtr TkEnd = consumeName(SepEnd, End);
+ if (TkEnd)
+ return makeState(PS_InFilenames, SepEnd, TkEnd);
+ }
+ return makeState(PS_InTrailingSep, Start, SepEnd);
+ }
+
+ case PS_InTrailingSep:
+ return makeState(PS_AtEnd);
+
+ case PS_InRootName:
+ case PS_AtEnd:
+ _LIBCPP_UNREACHABLE();
+ }
+ }
+
+ void decrement() noexcept {
+ const PosPtr REnd = getBeforeFront();
+ const PosPtr RStart = getCurrentTokenStartPos() - 1;
+ if (RStart == REnd) // we're decrementing the begin
+ return makeState(PS_BeforeBegin);
+
+ switch (State) {
+ case PS_AtEnd: {
+ // Try to consume a trailing separator or root directory first.
+ if (PosPtr SepEnd = consumeSeparator(RStart, REnd)) {
+ if (SepEnd == REnd)
+ return makeState(PS_InRootDir, Path.data(), RStart + 1);
+ return makeState(PS_InTrailingSep, SepEnd + 1, RStart + 1);
+ } else {
+ PosPtr TkStart = consumeName(RStart, REnd);
+ return makeState(PS_InFilenames, TkStart + 1, RStart + 1);
+ }
+ }
+ case PS_InTrailingSep:
+ return makeState(PS_InFilenames, consumeName(RStart, REnd) + 1,
+ RStart + 1);
+ case PS_InFilenames: {
+ PosPtr SepEnd = consumeSeparator(RStart, REnd);
+ if (SepEnd == REnd)
+ return makeState(PS_InRootDir, Path.data(), RStart + 1);
+ PosPtr TkEnd = consumeName(SepEnd, REnd);
+ return makeState(PS_InFilenames, TkEnd + 1, SepEnd + 1);
+ }
+ case PS_InRootDir:
+ // return makeState(PS_InRootName, Path.data(), RStart + 1);
+ case PS_InRootName:
+ case PS_BeforeBegin:
+ _LIBCPP_UNREACHABLE();
+ }
+ }
+
+ /// \brief Return a view with the "preferred representation" of the current
+ /// element. For example trailing separators are represented as a '.'
+ string_view_t operator*() const noexcept {
+ switch (State) {
+ case PS_BeforeBegin:
+ case PS_AtEnd:
+ return "";
+ case PS_InRootDir:
+ return "/";
+ case PS_InTrailingSep:
+ return "";
+ case PS_InRootName:
+ case PS_InFilenames:
+ return RawEntry;
+ }
+ _LIBCPP_UNREACHABLE();
+ }
+
+ explicit operator bool() const noexcept {
+ return State != PS_BeforeBegin && State != PS_AtEnd;
+ }
+
+ PathParser& operator++() noexcept {
+ increment();
+ return *this;
+ }
+
+ PathParser& operator--() noexcept {
+ decrement();
+ return *this;
+ }
+
+ bool inRootPath() const noexcept {
+ return State == PS_InRootDir || State == PS_InRootName;
+ }
+
+private:
+ void makeState(ParserState NewState, PosPtr Start, PosPtr End) noexcept {
+ State = NewState;
+ RawEntry = string_view_t(Start, End - Start);
+ }
+ void makeState(ParserState NewState) noexcept {
+ State = NewState;
+ RawEntry = {};
+ }
+
+ PosPtr getAfterBack() const noexcept { return Path.data() + Path.size(); }
+
+ PosPtr getBeforeFront() const noexcept { return Path.data() - 1; }
+
+ /// \brief Return a pointer to the first character after the currently
+ /// lexed element.
+ PosPtr getNextTokenStartPos() const noexcept {
+ switch (State) {
+ case PS_BeforeBegin:
+ return Path.data();
+ case PS_InRootName:
+ case PS_InRootDir:
+ case PS_InFilenames:
+ return &RawEntry.back() + 1;
+ case PS_InTrailingSep:
+ case PS_AtEnd:
+ return getAfterBack();
+ }
+ _LIBCPP_UNREACHABLE();
+ }
+
+ /// \brief Return a pointer to the first character in the currently lexed
+ /// element.
+ PosPtr getCurrentTokenStartPos() const noexcept {
+ switch (State) {
+ case PS_BeforeBegin:
+ case PS_InRootName:
+ return &Path.front();
+ case PS_InRootDir:
+ case PS_InFilenames:
+ case PS_InTrailingSep:
+ return &RawEntry.front();
+ case PS_AtEnd:
+ return &Path.back() + 1;
+ }
+ _LIBCPP_UNREACHABLE();
+ }
+
+ PosPtr consumeSeparator(PosPtr P, PosPtr End) const noexcept {
+ if (P == End || *P != '/')
+ return nullptr;
+ const int Inc = P < End ? 1 : -1;
+ P += Inc;
+ while (P != End && *P == '/')
+ P += Inc;
+ return P;
+ }
+
+ PosPtr consumeName(PosPtr P, PosPtr End) const noexcept {
+ if (P == End || *P == '/')
+ return nullptr;
+ const int Inc = P < End ? 1 : -1;
+ P += Inc;
+ while (P != End && *P != '/')
+ P += Inc;
+ return P;
+ }
+};
+
+string_view_pair separate_filename(string_view_t const& s) {
+ if (s == "." || s == ".." || s.empty())
+ return string_view_pair{s, ""};
+ auto pos = s.find_last_of('.');
+ if (pos == string_view_t::npos || pos == 0)
+ return string_view_pair{s, string_view_t{}};
+ return string_view_pair{s.substr(0, pos), s.substr(pos)};
+}
+
+string_view_t createView(PosPtr S, PosPtr E) noexcept {
+ return {S, static_cast<size_t>(E - S) + 1};
+}
+
+} // namespace parser
+} // namespace
+
+// POSIX HELPERS
+
+namespace detail {
+namespace {
+
+using value_type = path::value_type;
+using string_type = path::string_type;
+
+struct FileDescriptor {
+ const path& name;
+ int fd = -1;
+ StatT m_stat;
+ file_status m_status;
+
+ template <class... Args>
+ static FileDescriptor create(const path* p, error_code& ec, Args... args) {
+ ec.clear();
+ int fd;
+ if ((fd = ::open(p->c_str(), args...)) == -1) {
+ ec = capture_errno();
+ return FileDescriptor{p};
+ }
+ return FileDescriptor(p, fd);
+ }
+
+ template <class... Args>
+ static FileDescriptor create_with_status(const path* p, error_code& ec,
+ Args... args) {
+ FileDescriptor fd = create(p, ec, args...);
+ if (!ec)
+ fd.refresh_status(ec);
+
+ return fd;
+ }
+
+ file_status get_status() const { return m_status; }
+ StatT const& get_stat() const { return m_stat; }
+
+ bool status_known() const { return _VSTD_FS::status_known(m_status); }
+
+ file_status refresh_status(error_code& ec);
+
+ void close() noexcept {
+ if (fd != -1)
+ ::close(fd);
+ fd = -1;
+ }
+
+ FileDescriptor(FileDescriptor&& other)
+ : name(other.name), fd(other.fd), m_stat(other.m_stat),
+ m_status(other.m_status) {
+ other.fd = -1;
+ other.m_status = file_status{};
+ }
+
+ ~FileDescriptor() { close(); }
+
+ FileDescriptor() = default;
+ FileDescriptor(FileDescriptor const&) = delete;
+ FileDescriptor& operator=(FileDescriptor const&) = delete;
+
+private:
+ explicit FileDescriptor(const path* p, int fd = -1) : name(*p), fd(fd) {}
+};
+
+perms posix_get_perms(const StatT& st) noexcept {
+ return static_cast<perms>(st.st_mode) & perms::mask;
+}
+
+::mode_t posix_convert_perms(perms prms) {
+ return static_cast< ::mode_t>(prms & perms::mask);
+}
+
+file_status create_file_status(error_code& m_ec, path const& p,
+ const StatT& path_stat, error_code* ec) {
+ if (ec)
+ *ec = m_ec;
+ if (m_ec && (m_ec.value() == ENOENT || m_ec.value() == ENOTDIR)) {
+ return file_status(file_type::not_found);
+ } else if (m_ec) {
+ ErrorHandler<void> err("posix_stat", ec, &p);
+ err.report(m_ec, "failed to determine attributes for the specified path");
+ return file_status(file_type::none);
+ }
+ // else
+
+ file_status fs_tmp;
+ auto const mode = path_stat.st_mode;
+ if (S_ISLNK(mode))
+ fs_tmp.type(file_type::symlink);
+ else if (S_ISREG(mode))
+ fs_tmp.type(file_type::regular);
+ else if (S_ISDIR(mode))
+ fs_tmp.type(file_type::directory);
+ else if (S_ISBLK(mode))
+ fs_tmp.type(file_type::block);
+ else if (S_ISCHR(mode))
+ fs_tmp.type(file_type::character);
+ else if (S_ISFIFO(mode))
+ fs_tmp.type(file_type::fifo);
+ else if (S_ISSOCK(mode))
+ fs_tmp.type(file_type::socket);
+ else
+ fs_tmp.type(file_type::unknown);
+
+ fs_tmp.permissions(detail::posix_get_perms(path_stat));
+ return fs_tmp;
+}
+
+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();
+ return create_file_status(m_ec, p, path_stat, ec);
+}
+
+file_status posix_stat(path const& p, error_code* ec) {
+ StatT path_stat;
+ return posix_stat(p, path_stat, 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();
+ return create_file_status(m_ec, p, path_stat, ec);
+}
+
+file_status posix_lstat(path const& p, error_code* ec) {
+ StatT path_stat;
+ return posix_lstat(p, path_stat, ec);
+}
+
+bool posix_ftruncate(const FileDescriptor& fd, size_t to_size, error_code& ec) {
+ if (::ftruncate(fd.fd, to_size) == -1) {
+ ec = capture_errno();
+ return true;
+ }
+ ec.clear();
+ return false;
+}
+
+bool posix_fchmod(const FileDescriptor& fd, const StatT& st, error_code& ec) {
+ if (::fchmod(fd.fd, st.st_mode) == -1) {
+ ec = capture_errno();
+ return true;
+ }
+ ec.clear();
+ return false;
+}
+
+bool stat_equivalent(const StatT& st1, const StatT& st2) {
+ return (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino);
+}
+
+file_status FileDescriptor::refresh_status(error_code& ec) {
+ // FD must be open and good.
+ m_status = file_status{};
+ m_stat = {};
+ error_code m_ec;
+ if (::fstat(fd, &m_stat) == -1)
+ m_ec = capture_errno();
+ m_status = create_file_status(m_ec, name, m_stat, &ec);
+ return m_status;
+}
+} // namespace
+} // end namespace detail
+
+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 {
+ const char* p1 = path1().native().empty() ? "\"\"" : path1().c_str();
+ const char* p2 = path2().native().empty() ? "\"\"" : path2().c_str();
+ switch (__num_paths) {
+ default:
+ return detail::format_string("filesystem error: %s", derived_what);
+ case 1:
+ return detail::format_string("filesystem error: %s [%s]", derived_what,
+ p1);
+ case 2:
+ return detail::format_string("filesystem error: %s [%s] [%s]",
+ derived_what, p1, p2);
+ }
+ }();
+}
+
+static path __do_absolute(const path& p, path* cwd, error_code* ec) {
+ if (ec)
+ ec->clear();
+ if (p.is_absolute())
+ return p;
+ *cwd = __current_path(ec);
+ if (ec && *ec)
+ return {};
+ return (*cwd) / p;
+}
+
+path __absolute(const path& p, error_code* ec) {
+ path cwd;
+ return __do_absolute(p, &cwd, ec);
+}
+
+path __canonical(path const& orig_p, error_code* ec) {
+ path cwd;
+ ErrorHandler<path> err("canonical", ec, &orig_p, &cwd);
+
+ path p = __do_absolute(orig_p, &cwd, ec);
+ char buff[PATH_MAX + 1];
+ char* ret;
+ if ((ret = ::realpath(p.c_str(), buff)) == nullptr)
+ return err.report(capture_errno());
+ return {ret};
+}
+
+void __copy(const path& from, const path& to, copy_options options,
+ error_code* ec) {
+ ErrorHandler<void> err("copy", ec, &from, &to);
+
+ const bool sym_status = bool(
+ options & (copy_options::create_symlinks | copy_options::skip_symlinks));
+
+ const bool sym_status2 = bool(options & copy_options::copy_symlinks);
+
+ error_code m_ec1;
+ 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);
+
+ 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);
+
+ if (not status_known(t))
+ return err.report(m_ec1);
+
+ if (!exists(f) || is_other(f) || is_other(t) ||
+ (is_directory(f) && is_regular_file(t)) ||
+ detail::stat_equivalent(f_st, t_st)) {
+ return err.report(errc::function_not_supported);
+ }
+
+ if (ec)
+ ec->clear();
+
+ if (is_symlink(f)) {
+ if (bool(copy_options::skip_symlinks & options)) {
+ // do nothing
+ } else if (not exists(t)) {
+ __copy_symlink(from, to, ec);
+ } else {
+ return err.report(errc::file_exists);
+ }
+ return;
+ } else if (is_regular_file(f)) {
+ if (bool(copy_options::directories_only & options)) {
+ // do nothing
+ } else if (bool(copy_options::create_symlinks & options)) {
+ __create_symlink(from, to, ec);
+ } else if (bool(copy_options::create_hard_links & options)) {
+ __create_hard_link(from, to, ec);
+ } else if (is_directory(t)) {
+ __copy_file(from, to / from.filename(), options, ec);
+ } else {
+ __copy_file(from, to, options, ec);
+ }
+ return;
+ } else if (is_directory(f) && bool(copy_options::create_symlinks & options)) {
+ return err.report(errc::is_a_directory);
+ } else if (is_directory(f) && (bool(copy_options::recursive & options) ||
+ copy_options::none == options)) {
+
+ if (!exists(t)) {
+ // create directory to with attributes from 'from'.
+ __create_directory(to, from, ec);
+ if (ec && *ec) {
+ return;
+ }
+ }
+ directory_iterator it =
+ ec ? directory_iterator(from, *ec) : directory_iterator(from);
+ if (ec && *ec) {
+ return;
+ }
+ error_code m_ec2;
+ for (; it != directory_iterator(); it.increment(m_ec2)) {
+ if (m_ec2) {
+ return err.report(m_ec2);
+ }
+ __copy(it->path(), to / it->path().filename(),
+ options | copy_options::__in_recursive_copy, ec);
+ if (ec && *ec) {
+ return;
+ }
+ }
+ }
+}
+
+namespace detail {
+namespace {
+
+#ifdef _LIBCPP_USE_SENDFILE
+bool copy_file_impl_sendfile(FileDescriptor& read_fd, FileDescriptor& write_fd,
+ error_code& ec) {
+
+ size_t count = read_fd.get_stat().st_size;
+ do {
+ ssize_t res;
+ if ((res = ::sendfile(write_fd.fd, read_fd.fd, nullptr, count)) == -1) {
+ ec = capture_errno();
+ return false;
+ }
+ count -= res;
+ } while (count > 0);
+
+ ec.clear();
+
+ return true;
+}
+#elif defined(_LIBCPP_USE_COPYFILE)
+bool copy_file_impl_copyfile(FileDescriptor& read_fd, FileDescriptor& write_fd,
+ error_code& ec) {
+ struct CopyFileState {
+ copyfile_state_t state;
+ CopyFileState() { state = copyfile_state_alloc(); }
+ ~CopyFileState() { copyfile_state_free(state); }
+
+ private:
+ CopyFileState(CopyFileState const&) = delete;
+ CopyFileState& operator=(CopyFileState const&) = delete;
+ };
+
+ CopyFileState cfs;
+ if (fcopyfile(read_fd.fd, write_fd.fd, cfs.state, COPYFILE_DATA) < 0) {
+ ec = capture_errno();
+ return false;
+ }
+
+ ec.clear();
+ return true;
+}
+#endif
+
+// Note: This function isn't guarded by ifdef's even though it may be unused
+// in order to assure it still compiles.
+__attribute__((unused)) bool copy_file_impl_default(FileDescriptor& read_fd,
+ FileDescriptor& write_fd,
+ error_code& ec) {
+ ifstream in;
+ in.__open(read_fd.fd, ios::binary);
+ if (!in.is_open()) {
+ // This assumes that __open didn't reset the error code.
+ ec = capture_errno();
+ return false;
+ }
+ ofstream out;
+ out.__open(write_fd.fd, ios::binary);
+ if (!out.is_open()) {
+ ec = capture_errno();
+ return false;
+ }
+
+ if (in.good() && out.good()) {
+ using InIt = istreambuf_iterator<char>;
+ using OutIt = ostreambuf_iterator<char>;
+ InIt bin(in);
+ InIt ein;
+ OutIt bout(out);
+ copy(bin, ein, bout);
+ }
+ if (out.fail() || in.fail()) {
+ ec = make_error_code(errc::io_error);
+ return false;
+ }
+
+ ec.clear();
+ return true;
+}
+
+bool copy_file_impl(FileDescriptor& from, FileDescriptor& to, error_code& ec) {
+#if defined(_LIBCPP_USE_SENDFILE)
+ return copy_file_impl_sendfile(from, to, ec);
+#elif defined(_LIBCPP_USE_COPYFILE)
+ return copy_file_impl_copyfile(from, to, ec);
+#else
+ return copy_file_impl_default(from, to, ec);
+#endif
+}
+
+} // namespace
+} // namespace detail
+
+bool __copy_file(const path& from, const path& to, copy_options options,
+ error_code* ec) {
+ using detail::FileDescriptor;
+ ErrorHandler<bool> err("copy_file", ec, &to, &from);
+
+ error_code m_ec;
+ FileDescriptor from_fd =
+ FileDescriptor::create_with_status(&from, m_ec, O_RDONLY | O_NONBLOCK);
+ if (m_ec)
+ return err.report(m_ec);
+
+ auto from_st = from_fd.get_status();
+ StatT const& from_stat = from_fd.get_stat();
+ if (!is_regular_file(from_st)) {
+ if (not m_ec)
+ m_ec = make_error_code(errc::not_supported);
+ return err.report(m_ec);
+ }
+
+ const bool skip_existing = bool(copy_options::skip_existing & options);
+ const bool update_existing = bool(copy_options::update_existing & options);
+ const bool overwrite_existing =
+ bool(copy_options::overwrite_existing & options);
+
+ StatT to_stat_path;
+ file_status to_st = detail::posix_stat(to, to_stat_path, &m_ec);
+ if (!status_known(to_st))
+ return err.report(m_ec);
+
+ const bool to_exists = exists(to_st);
+ if (to_exists && !is_regular_file(to_st))
+ return err.report(errc::not_supported);
+
+ if (to_exists && detail::stat_equivalent(from_stat, to_stat_path))
+ return err.report(errc::file_exists);
+
+ if (to_exists && skip_existing)
+ return false;
+
+ bool ShouldCopy = [&]() {
+ if (to_exists && update_existing) {
+ auto from_time = detail::extract_mtime(from_stat);
+ auto to_time = detail::extract_mtime(to_stat_path);
+ if (from_time.tv_sec < to_time.tv_sec)
+ return false;
+ if (from_time.tv_sec == to_time.tv_sec &&
+ from_time.tv_nsec <= to_time.tv_nsec)
+ return false;
+ return true;
+ }
+ if (!to_exists || overwrite_existing)
+ return true;
+ return err.report(errc::file_exists);
+ }();
+ if (!ShouldCopy)
+ return false;
+
+ // Don't truncate right away. We may not be opening the file we originally
+ // looked at; we'll check this later.
+ int to_open_flags = O_WRONLY;
+ if (!to_exists)
+ to_open_flags |= O_CREAT;
+ FileDescriptor to_fd = FileDescriptor::create_with_status(
+ &to, m_ec, to_open_flags, from_stat.st_mode);
+ if (m_ec)
+ return err.report(m_ec);
+
+ if (to_exists) {
+ // Check that the file we initially stat'ed is equivalent to the one
+ // we opened.
+ // FIXME: report this better.
+ if (!detail::stat_equivalent(to_stat_path, to_fd.get_stat()))
+ return err.report(errc::bad_file_descriptor);
+
+ // Set the permissions and truncate the file we opened.
+ if (detail::posix_fchmod(to_fd, from_stat, m_ec))
+ return err.report(m_ec);
+ if (detail::posix_ftruncate(to_fd, 0, m_ec))
+ return err.report(m_ec);
+ }
+
+ if (!copy_file_impl(from_fd, to_fd, m_ec)) {
+ // FIXME: Remove the dest file if we failed, and it didn't exist previously.
+ return err.report(m_ec);
+ }
+
+ return true;
+}
+
+void __copy_symlink(const path& existing_symlink, const path& new_symlink,
+ error_code* ec) {
+ const path real_path(__read_symlink(existing_symlink, ec));
+ if (ec && *ec) {
+ return;
+ }
+ // NOTE: proposal says you should detect if you should call
+ // create_symlink or create_directory_symlink. I don't think this
+ // is needed with POSIX
+ __create_symlink(real_path, new_symlink, ec);
+}
+
+bool __create_directories(const path& p, error_code* ec) {
+ ErrorHandler<bool> err("create_directories", ec, &p);
+
+ error_code m_ec;
+ auto const st = detail::posix_stat(p, &m_ec);
+ if (!status_known(st))
+ return err.report(m_ec);
+ else if (is_directory(st))
+ return false;
+ else if (exists(st))
+ return err.report(errc::file_exists);
+
+ const path parent = p.parent_path();
+ if (!parent.empty()) {
+ const file_status parent_st = status(parent, m_ec);
+ if (not status_known(parent_st))
+ return err.report(m_ec);
+ if (not exists(parent_st)) {
+ __create_directories(parent, ec);
+ if (ec && *ec) {
+ return false;
+ }
+ }
+ }
+ return __create_directory(p, ec);
+}
+
+bool __create_directory(const path& p, error_code* ec) {
+ ErrorHandler<bool> err("create_directory", ec, &p);
+
+ if (::mkdir(p.c_str(), static_cast<int>(perms::all)) == 0)
+ return true;
+ if (errno != EEXIST)
+ err.report(capture_errno());
+ return false;
+}
+
+bool __create_directory(path const& p, path const& attributes, error_code* ec) {
+ ErrorHandler<bool> err("create_directory", ec, &p, &attributes);
+
+ StatT attr_stat;
+ error_code mec;
+ auto st = detail::posix_stat(attributes, attr_stat, &mec);
+ if (!status_known(st))
+ return err.report(mec);
+ if (!is_directory(st))
+ return err.report(errc::not_a_directory,
+ "the specified attribute path is invalid");
+
+ if (::mkdir(p.c_str(), attr_stat.st_mode) == 0)
+ return true;
+ if (errno != EEXIST)
+ err.report(capture_errno());
+ return false;
+}
+
+void __create_directory_symlink(path const& from, path const& to,
+ error_code* ec) {
+ ErrorHandler<void> err("create_directory_symlink", ec, &from, &to);
+ if (::symlink(from.c_str(), to.c_str()) != 0)
+ return err.report(capture_errno());
+}
+
+void __create_hard_link(const path& from, const path& to, error_code* ec) {
+ ErrorHandler<void> err("create_hard_link", ec, &from, &to);
+ if (::link(from.c_str(), to.c_str()) == -1)
+ return err.report(capture_errno());
+}
+
+void __create_symlink(path const& from, path const& to, error_code* ec) {
+ ErrorHandler<void> err("create_symlink", ec, &from, &to);
+ if (::symlink(from.c_str(), to.c_str()) == -1)
+ return err.report(capture_errno());
+}
+
+path __current_path(error_code* ec) {
+ ErrorHandler<path> err("current_path", ec);
+
+ auto size = ::pathconf(".", _PC_PATH_MAX);
+ _LIBCPP_ASSERT(size >= 0, "pathconf returned a 0 as max size");
+
+ auto buff = unique_ptr<char[]>(new char[size + 1]);
+ char* ret;
+ if ((ret = ::getcwd(buff.get(), static_cast<size_t>(size))) == nullptr)
+ return err.report(capture_errno(), "call to getcwd failed");
+
+ return {buff.get()};
+}
+
+void __current_path(const path& p, error_code* ec) {
+ ErrorHandler<void> err("current_path", ec, &p);
+ if (::chdir(p.c_str()) == -1)
+ err.report(capture_errno());
+}
+
+bool __equivalent(const path& p1, const path& p2, error_code* ec) {
+ ErrorHandler<bool> err("equivalent", ec, &p1, &p2);
+
+ error_code ec1, ec2;
+ StatT st1 = {}, st2 = {};
+ auto s1 = detail::posix_stat(p1.native(), st1, &ec1);
+ if (!exists(s1))
+ return err.report(errc::not_supported);
+ auto s2 = detail::posix_stat(p2.native(), st2, &ec2);
+ if (!exists(s2))
+ return err.report(errc::not_supported);
+
+ return detail::stat_equivalent(st1, st2);
+}
+
+uintmax_t __file_size(const path& p, error_code* ec) {
+ ErrorHandler<uintmax_t> err("file_size", ec, &p);
+
+ error_code m_ec;
+ StatT st;
+ file_status fst = detail::posix_stat(p, st, &m_ec);
+ if (!exists(fst) || !is_regular_file(fst)) {
+ errc error_kind =
+ is_directory(fst) ? errc::is_a_directory : errc::not_supported;
+ if (!m_ec)
+ m_ec = make_error_code(error_kind);
+ return err.report(m_ec);
+ }
+ // is_regular_file(p) == true
+ return static_cast<uintmax_t>(st.st_size);
+}
+
+uintmax_t __hard_link_count(const path& p, error_code* ec) {
+ ErrorHandler<uintmax_t> err("hard_link_count", ec, &p);
+
+ error_code m_ec;
+ StatT st;
+ detail::posix_stat(p, st, &m_ec);
+ if (m_ec)
+ return err.report(m_ec);
+ return static_cast<uintmax_t>(st.st_nlink);
+}
+
+bool __fs_is_empty(const path& p, error_code* ec) {
+ ErrorHandler<bool> err("is_empty", ec, &p);
+
+ error_code m_ec;
+ StatT pst;
+ auto st = detail::posix_stat(p, pst, &m_ec);
+ if (m_ec)
+ return err.report(m_ec);
+ else if (!is_directory(st) && !is_regular_file(st))
+ return err.report(errc::not_supported);
+ else if (is_directory(st)) {
+ auto it = ec ? directory_iterator(p, *ec) : directory_iterator(p);
+ if (ec && *ec)
+ return false;
+ return it == directory_iterator{};
+ } else if (is_regular_file(st))
+ return static_cast<uintmax_t>(pst.st_size) == 0;
+
+ _LIBCPP_UNREACHABLE();
+}
+
+static file_time_type __extract_last_write_time(const path& p, const StatT& st,
+ error_code* ec) {
+ using detail::fs_time;
+ ErrorHandler<file_time_type> err("last_write_time", ec, &p);
+
+ auto ts = detail::extract_mtime(st);
+ if (!fs_time::is_representable(ts))
+ return err.report(errc::value_too_large);
+
+ return fs_time::convert_from_timespec(ts);
+}
+
+file_time_type __last_write_time(const path& p, error_code* ec) {
+ using namespace chrono;
+ ErrorHandler<file_time_type> err("last_write_time", ec, &p);
+
+ error_code m_ec;
+ StatT st;
+ detail::posix_stat(p, st, &m_ec);
+ if (m_ec)
+ return err.report(m_ec);
+ return __extract_last_write_time(p, st, ec);
+}
+
+void __last_write_time(const path& p, file_time_type new_time, error_code* ec) {
+ using detail::fs_time;
+ ErrorHandler<void> err("last_write_time", ec, &p);
+
+ error_code m_ec;
+ 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
+ StatT st;
+ file_status fst = detail::posix_stat(p, st, &m_ec);
+ if (m_ec)
+ return err.report(m_ec);
+ tbuf[0] = detail::extract_atime(st);
+#else
+ tbuf[0].tv_sec = 0;
+ tbuf[0].tv_nsec = UTIME_OMIT;
+#endif
+ if (!fs_time::convert_to_timespec(tbuf[1], new_time))
+ return err.report(errc::value_too_large);
+
+ detail::set_file_times(p, tbuf, m_ec);
+ if (m_ec)
+ return err.report(m_ec);
+}
+
+void __permissions(const path& p, perms prms, perm_options opts,
+ error_code* ec) {
+ ErrorHandler<void> err("permissions", ec, &p);
+
+ auto has_opt = [&](perm_options o) { return bool(o & opts); };
+ const bool resolve_symlinks = !has_opt(perm_options::nofollow);
+ const bool add_perms = has_opt(perm_options::add);
+ const bool remove_perms = has_opt(perm_options::remove);
+ _LIBCPP_ASSERT(
+ (add_perms + remove_perms + has_opt(perm_options::replace)) == 1,
+ "One and only one of the perm_options constants replace, add, or remove "
+ "is present in opts");
+
+ bool set_sym_perms = false;
+ prms &= perms::mask;
+ if (!resolve_symlinks || (add_perms || remove_perms)) {
+ error_code m_ec;
+ file_status st = resolve_symlinks ? detail::posix_stat(p, &m_ec)
+ : detail::posix_lstat(p, &m_ec);
+ set_sym_perms = is_symlink(st);
+ if (m_ec)
+ return err.report(m_ec);
+ _LIBCPP_ASSERT(st.permissions() != perms::unknown,
+ "Permissions unexpectedly unknown");
+ if (add_perms)
+ prms |= st.permissions();
+ else if (remove_perms)
+ prms = st.permissions() & ~prms;
+ }
+ const auto real_perms = detail::posix_convert_perms(prms);
+
+#if defined(AT_SYMLINK_NOFOLLOW) && defined(AT_FDCWD)
+ const int flags = set_sym_perms ? AT_SYMLINK_NOFOLLOW : 0;
+ if (::fchmodat(AT_FDCWD, p.c_str(), real_perms, flags) == -1) {
+ return err.report(capture_errno());
+ }
+#else
+ if (set_sym_perms)
+ return err.report(errc::operation_not_supported);
+ if (::chmod(p.c_str(), real_perms) == -1) {
+ return err.report(capture_errno());
+ }
+#endif
+}
+
+path __read_symlink(const path& p, error_code* ec) {
+ ErrorHandler<path> err("read_symlink", ec, &p);
+
+ char buff[PATH_MAX + 1];
+ error_code m_ec;
+ ::ssize_t ret;
+ if ((ret = ::readlink(p.c_str(), buff, PATH_MAX)) == -1) {
+ return err.report(capture_errno());
+ }
+ _LIBCPP_ASSERT(ret <= PATH_MAX, "TODO");
+ _LIBCPP_ASSERT(ret > 0, "TODO");
+ buff[ret] = 0;
+ return {buff};
+}
+
+bool __remove(const path& p, error_code* ec) {
+ ErrorHandler<bool> err("remove", ec, &p);
+ if (::remove(p.c_str()) == -1) {
+ if (errno != ENOENT)
+ err.report(capture_errno());
+ return false;
+ }
+ return true;
+}
+
+namespace {
+
+uintmax_t remove_all_impl(path const& p, error_code& ec) {
+ const auto npos = static_cast<uintmax_t>(-1);
+ const file_status st = __symlink_status(p, &ec);
+ if (ec)
+ return npos;
+ uintmax_t count = 1;
+ if (is_directory(st)) {
+ for (directory_iterator it(p, ec); !ec && it != directory_iterator();
+ it.increment(ec)) {
+ auto other_count = remove_all_impl(it->path(), ec);
+ if (ec)
+ return npos;
+ count += other_count;
+ }
+ if (ec)
+ return npos;
+ }
+ if (!__remove(p, &ec))
+ return npos;
+ return count;
+}
+
+} // end namespace
+
+uintmax_t __remove_all(const path& p, error_code* ec) {
+ ErrorHandler<uintmax_t> err("remove_all", ec, &p);
+
+ error_code mec;
+ auto count = remove_all_impl(p, mec);
+ if (mec) {
+ if (mec == errc::no_such_file_or_directory)
+ return 0;
+ return err.report(mec);
+ }
+ return count;
+}
+
+void __rename(const path& from, const path& to, error_code* ec) {
+ ErrorHandler<void> err("rename", ec, &from, &to);
+ if (::rename(from.c_str(), to.c_str()) == -1)
+ err.report(capture_errno());
+}
+
+void __resize_file(const path& p, uintmax_t size, error_code* ec) {
+ ErrorHandler<void> err("resize_file", ec, &p);
+ if (::truncate(p.c_str(), static_cast< ::off_t>(size)) == -1)
+ return err.report(capture_errno());
+}
+
+space_info __space(const path& p, error_code* ec) {
+ ErrorHandler<void> err("space", ec, &p);
+ space_info si;
+ struct statvfs m_svfs = {};
+ if (::statvfs(p.c_str(), &m_svfs) == -1) {
+ err.report(capture_errno());
+ si.capacity = si.free = si.available = static_cast<uintmax_t>(-1);
+ return si;
+ }
+ // Multiply with overflow checking.
+ auto do_mult = [&](uintmax_t& out, uintmax_t other) {
+ out = other * m_svfs.f_frsize;
+ if (other == 0 || out / other != m_svfs.f_frsize)
+ out = static_cast<uintmax_t>(-1);
+ };
+ do_mult(si.capacity, m_svfs.f_blocks);
+ do_mult(si.free, m_svfs.f_bfree);
+ do_mult(si.available, m_svfs.f_bavail);
+ return si;
+}
+
+file_status __status(const path& p, error_code* ec) {
+ return detail::posix_stat(p, ec);
+}
+
+file_status __symlink_status(const path& p, error_code* ec) {
+ return detail::posix_lstat(p, ec);
+}
+
+path __temp_directory_path(error_code* ec) {
+ ErrorHandler<path> err("temp_directory_path", ec);
+
+ const char* env_paths[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
+ const char* ret = nullptr;
+
+ for (auto& ep : env_paths)
+ if ((ret = getenv(ep)))
+ break;
+ if (ret == nullptr)
+ ret = "/tmp";
+
+ path p(ret);
+ error_code m_ec;
+ file_status st = detail::posix_stat(p, &m_ec);
+ if (!status_known(st))
+ return err.report(m_ec, "cannot access path \"%s\"", p);
+
+ if (!exists(st) || !is_directory(st))
+ return err.report(errc::not_a_directory, "path \"%s\" is not a directory",
+ p);
+
+ return p;
+}
+
+path __weakly_canonical(const path& p, error_code* ec) {
+ ErrorHandler<path> err("weakly_canonical", ec, &p);
+
+ if (p.empty())
+ return __canonical("", ec);
+
+ path result;
+ path tmp;
+ tmp.__reserve(p.native().size());
+ auto PP = PathParser::CreateEnd(p.native());
+ --PP;
+ vector<string_view_t> DNEParts;
+
+ while (PP.State != PathParser::PS_BeforeBegin) {
+ tmp.assign(createView(p.native().data(), &PP.RawEntry.back()));
+ error_code m_ec;
+ file_status st = __status(tmp, &m_ec);
+ if (!status_known(st)) {
+ return err.report(m_ec);
+ } else if (exists(st)) {
+ result = __canonical(tmp, ec);
+ break;
+ }
+ DNEParts.push_back(*PP);
+ --PP;
+ }
+ if (PP.State == PathParser::PS_BeforeBegin)
+ result = __canonical("", ec);
+ if (ec)
+ ec->clear();
+ if (DNEParts.empty())
+ return result;
+ for (auto It = DNEParts.rbegin(); It != DNEParts.rend(); ++It)
+ result /= *It;
+ return result.lexically_normal();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// path definitions
+///////////////////////////////////////////////////////////////////////////////
+
+constexpr path::value_type path::preferred_separator;
+
+path& path::replace_extension(path const& replacement) {
+ path p = extension();
+ if (not p.empty()) {
+ __pn_.erase(__pn_.size() - p.native().size());
+ }
+ if (!replacement.empty()) {
+ if (replacement.native()[0] != '.') {
+ __pn_ += ".";
+ }
+ __pn_.append(replacement.__pn_);
+ }
+ return *this;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// path.decompose
+
+string_view_t path::__root_name() const {
+ auto PP = PathParser::CreateBegin(__pn_);
+ if (PP.State == PathParser::PS_InRootName)
+ return *PP;
+ return {};
+}
+
+string_view_t path::__root_directory() const {
+ auto PP = PathParser::CreateBegin(__pn_);
+ if (PP.State == PathParser::PS_InRootName)
+ ++PP;
+ if (PP.State == PathParser::PS_InRootDir)
+ return *PP;
+ return {};
+}
+
+string_view_t path::__root_path_raw() const {
+ auto PP = PathParser::CreateBegin(__pn_);
+ if (PP.State == PathParser::PS_InRootName) {
+ auto NextCh = PP.peek();
+ if (NextCh && *NextCh == '/') {
+ ++PP;
+ return createView(__pn_.data(), &PP.RawEntry.back());
+ }
+ return PP.RawEntry;
+ }
+ if (PP.State == PathParser::PS_InRootDir)
+ return *PP;
+ return {};
+}
+
+static bool ConsumeRootDir(PathParser* PP) {
+ while (PP->State <= PathParser::PS_InRootDir)
+ ++(*PP);
+ return PP->State == PathParser::PS_AtEnd;
+}
+
+string_view_t path::__relative_path() const {
+ auto PP = PathParser::CreateBegin(__pn_);
+ if (ConsumeRootDir(&PP))
+ return {};
+ return createView(PP.RawEntry.data(), &__pn_.back());
+}
+
+string_view_t path::__parent_path() const {
+ if (empty())
+ return {};
+ // Determine if we have a root path but not a relative path. In that case
+ // return *this.
+ {
+ auto PP = PathParser::CreateBegin(__pn_);
+ if (ConsumeRootDir(&PP))
+ return __pn_;
+ }
+ // Otherwise remove a single element from the end of the path, and return
+ // a string representing that path
+ {
+ auto PP = PathParser::CreateEnd(__pn_);
+ --PP;
+ if (PP.RawEntry.data() == __pn_.data())
+ return {};
+ --PP;
+ return createView(__pn_.data(), &PP.RawEntry.back());
+ }
+}
+
+string_view_t path::__filename() const {
+ if (empty())
+ return {};
+ {
+ PathParser PP = PathParser::CreateBegin(__pn_);
+ if (ConsumeRootDir(&PP))
+ return {};
+ }
+ return *(--PathParser::CreateEnd(__pn_));
+}
+
+string_view_t path::__stem() const {
+ return parser::separate_filename(__filename()).first;
+}
+
+string_view_t path::__extension() const {
+ return parser::separate_filename(__filename()).second;
+}
+
+////////////////////////////////////////////////////////////////////////////
+// path.gen
+
+enum PathPartKind : unsigned char {
+ PK_None,
+ PK_RootSep,
+ PK_Filename,
+ PK_Dot,
+ PK_DotDot,
+ PK_TrailingSep
+};
+
+static PathPartKind ClassifyPathPart(string_view_t Part) {
+ if (Part.empty())
+ return PK_TrailingSep;
+ if (Part == ".")
+ return PK_Dot;
+ if (Part == "..")
+ return PK_DotDot;
+ if (Part == "/")
+ return PK_RootSep;
+ return PK_Filename;
+}
+
+path path::lexically_normal() const {
+ if (__pn_.empty())
+ return *this;
+
+ using PartKindPair = pair<string_view_t, PathPartKind>;
+ vector<PartKindPair> Parts;
+ // Guess as to how many elements the path has to avoid reallocating.
+ Parts.reserve(32);
+
+ // Track the total size of the parts as we collect them. This allows the
+ // resulting path to reserve the correct amount of memory.
+ size_t NewPathSize = 0;
+ auto AddPart = [&](PathPartKind K, string_view_t P) {
+ NewPathSize += P.size();
+ Parts.emplace_back(P, K);
+ };
+ auto LastPartKind = [&]() {
+ if (Parts.empty())
+ return PK_None;
+ return Parts.back().second;
+ };
+
+ bool MaybeNeedTrailingSep = false;
+ // Build a stack containing the remaining elements of the path, popping off
+ // elements which occur before a '..' entry.
+ for (auto PP = PathParser::CreateBegin(__pn_); PP; ++PP) {
+ auto Part = *PP;
+ PathPartKind Kind = ClassifyPathPart(Part);
+ switch (Kind) {
+ case PK_Filename:
+ case PK_RootSep: {
+ // Add all non-dot and non-dot-dot elements to the stack of elements.
+ AddPart(Kind, Part);
+ MaybeNeedTrailingSep = false;
+ break;
+ }
+ case PK_DotDot: {
+ // Only push a ".." element if there are no elements preceding the "..",
+ // or if the preceding element is itself "..".
+ auto LastKind = LastPartKind();
+ if (LastKind == PK_Filename) {
+ NewPathSize -= Parts.back().first.size();
+ Parts.pop_back();
+ } else if (LastKind != PK_RootSep)
+ AddPart(PK_DotDot, "..");
+ MaybeNeedTrailingSep = LastKind == PK_Filename;
+ break;
+ }
+ case PK_Dot:
+ case PK_TrailingSep: {
+ MaybeNeedTrailingSep = true;
+ break;
+ }
+ case PK_None:
+ _LIBCPP_UNREACHABLE();
+ }
+ }
+ // [fs.path.generic]p6.8: If the path is empty, add a dot.
+ if (Parts.empty())
+ return ".";
+
+ // [fs.path.generic]p6.7: If the last filename is dot-dot, remove any
+ // trailing directory-separator.
+ bool NeedTrailingSep = MaybeNeedTrailingSep && LastPartKind() == PK_Filename;
+
+ path Result;
+ Result.__pn_.reserve(Parts.size() + NewPathSize + NeedTrailingSep);
+ for (auto& PK : Parts)
+ Result /= PK.first;
+
+ if (NeedTrailingSep)
+ Result /= "";
+
+ return Result;
+}
+
+static int DetermineLexicalElementCount(PathParser PP) {
+ int Count = 0;
+ for (; PP; ++PP) {
+ auto Elem = *PP;
+ if (Elem == "..")
+ --Count;
+ else if (Elem != ".")
+ ++Count;
+ }
+ return Count;
+}
+
+path path::lexically_relative(const path& base) const {
+ { // perform root-name/root-directory mismatch checks
+ auto PP = PathParser::CreateBegin(__pn_);
+ auto PPBase = PathParser::CreateBegin(base.__pn_);
+ auto CheckIterMismatchAtBase = [&]() {
+ return PP.State != PPBase.State &&
+ (PP.inRootPath() || PPBase.inRootPath());
+ };
+ if (PP.State == PathParser::PS_InRootName &&
+ PPBase.State == PathParser::PS_InRootName) {
+ if (*PP != *PPBase)
+ return {};
+ } else if (CheckIterMismatchAtBase())
+ return {};
+
+ if (PP.inRootPath())
+ ++PP;
+ if (PPBase.inRootPath())
+ ++PPBase;
+ if (CheckIterMismatchAtBase())
+ return {};
+ }
+
+ // Find the first mismatching element
+ auto PP = PathParser::CreateBegin(__pn_);
+ auto PPBase = PathParser::CreateBegin(base.__pn_);
+ while (PP && PPBase && PP.State == PPBase.State && *PP == *PPBase) {
+ ++PP;
+ ++PPBase;
+ }
+
+ // If there is no mismatch, return ".".
+ if (!PP && !PPBase)
+ return ".";
+
+ // Otherwise, determine the number of elements, 'n', which are not dot or
+ // dot-dot minus the number of dot-dot elements.
+ int ElemCount = DetermineLexicalElementCount(PPBase);
+ if (ElemCount < 0)
+ return {};
+
+ // return a path constructed with 'n' dot-dot elements, followed by the the
+ // elements of '*this' after the mismatch.
+ path Result;
+ // FIXME: Reserve enough room in Result that it won't have to re-allocate.
+ while (ElemCount--)
+ Result /= "..";
+ for (; PP; ++PP)
+ Result /= *PP;
+ return Result;
+}
+
+////////////////////////////////////////////////////////////////////////////
+// path.comparisons
+int path::__compare(string_view_t __s) const {
+ auto PP = PathParser::CreateBegin(__pn_);
+ auto PP2 = PathParser::CreateBegin(__s);
+ while (PP && PP2) {
+ int res = (*PP).compare(*PP2);
+ if (res != 0)
+ return res;
+ ++PP;
+ ++PP2;
+ }
+ if (PP.State == PP2.State && !PP)
+ return 0;
+ if (!PP)
+ return -1;
+ return 1;
+}
+
+////////////////////////////////////////////////////////////////////////////
+// path.nonmembers
+size_t hash_value(const path& __p) noexcept {
+ auto PP = PathParser::CreateBegin(__p.native());
+ size_t hash_value = 0;
+ hash<string_view_t> hasher;
+ while (PP) {
+ hash_value = __hash_combine(hash_value, hasher(*PP));
+ ++PP;
+ }
+ return hash_value;
+}
+
+////////////////////////////////////////////////////////////////////////////
+// path.itr
+path::iterator path::begin() const {
+ auto PP = PathParser::CreateBegin(__pn_);
+ iterator it;
+ it.__path_ptr_ = this;
+ it.__state_ = static_cast<path::iterator::_ParserState>(PP.State);
+ it.__entry_ = PP.RawEntry;
+ it.__stashed_elem_.__assign_view(*PP);
+ return it;
+}
+
+path::iterator path::end() const {
+ iterator it{};
+ it.__state_ = path::iterator::_AtEnd;
+ it.__path_ptr_ = this;
+ return it;
+}
+
+path::iterator& path::iterator::__increment() {
+ PathParser PP(__path_ptr_->native(), __entry_, __state_);
+ ++PP;
+ __state_ = static_cast<_ParserState>(PP.State);
+ __entry_ = PP.RawEntry;
+ __stashed_elem_.__assign_view(*PP);
+ return *this;
+}
+
+path::iterator& path::iterator::__decrement() {
+ PathParser PP(__path_ptr_->native(), __entry_, __state_);
+ --PP;
+ __state_ = static_cast<_ParserState>(PP.State);
+ __entry_ = PP.RawEntry;
+ __stashed_elem_.__assign_view(*PP);
+ return *this;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// directory entry definitions
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _LIBCPP_WIN32API
+error_code directory_entry::__do_refresh() noexcept {
+ __data_.__reset();
+ error_code failure_ec;
+
+ StatT full_st;
+ file_status st = detail::posix_lstat(__p_, full_st, &failure_ec);
+ if (!status_known(st)) {
+ __data_.__reset();
+ return failure_ec;
+ }
+
+ if (!_VSTD_FS::exists(st) || !_VSTD_FS::is_symlink(st)) {
+ __data_.__cache_type_ = directory_entry::_RefreshNonSymlink;
+ __data_.__type_ = st.type();
+ __data_.__non_sym_perms_ = st.permissions();
+ } else { // we have a symlink
+ __data_.__sym_perms_ = st.permissions();
+ // Get the information about the linked entity.
+ // Ignore errors from stat, since we don't want errors regarding symlink
+ // resolution to be reported to the user.
+ error_code ignored_ec;
+ st = detail::posix_stat(__p_, full_st, &ignored_ec);
+
+ __data_.__type_ = st.type();
+ __data_.__non_sym_perms_ = st.permissions();
+
+ // If we failed to resolve the link, then only partially populate the
+ // cache.
+ if (!status_known(st)) {
+ __data_.__cache_type_ = directory_entry::_RefreshSymlinkUnresolved;
+ return error_code{};
+ }
+ // Otherwise, we resolved the link, potentially as not existing.
+ // That's OK.
+ __data_.__cache_type_ = directory_entry::_RefreshSymlink;
+ }
+
+ if (_VSTD_FS::is_regular_file(st))
+ __data_.__size_ = static_cast<uintmax_t>(full_st.st_size);
+
+ if (_VSTD_FS::exists(st)) {
+ __data_.__nlink_ = static_cast<uintmax_t>(full_st.st_nlink);
+
+ // Attempt to extract the mtime, and fail if it's not representable using
+ // file_time_type. For now we ignore the error, as we'll report it when
+ // the value is actually used.
+ error_code ignored_ec;
+ __data_.__write_time_ =
+ __extract_last_write_time(__p_, full_st, &ignored_ec);
+ }
+
+ return failure_ec;
+}
+#else
+error_code directory_entry::__do_refresh() noexcept {
+ __data_.__reset();
+ error_code failure_ec;
+
+ file_status st = _VSTD_FS::symlink_status(__p_, failure_ec);
+ if (!status_known(st)) {
+ __data_.__reset();
+ return failure_ec;
+ }
+
+ if (!_VSTD_FS::exists(st) || !_VSTD_FS::is_symlink(st)) {
+ __data_.__cache_type_ = directory_entry::_RefreshNonSymlink;
+ __data_.__type_ = st.type();
+ __data_.__non_sym_perms_ = st.permissions();
+ } else { // we have a symlink
+ __data_.__sym_perms_ = st.permissions();
+ // Get the information about the linked entity.
+ // Ignore errors from stat, since we don't want errors regarding symlink
+ // resolution to be reported to the user.
+ error_code ignored_ec;
+ st = _VSTD_FS::status(__p_, ignored_ec);
+
+ __data_.__type_ = st.type();
+ __data_.__non_sym_perms_ = st.permissions();
+
+ // If we failed to resolve the link, then only partially populate the
+ // cache.
+ if (!status_known(st)) {
+ __data_.__cache_type_ = directory_entry::_RefreshSymlinkUnresolved;
+ return error_code{};
+ }
+ __data_.__cache_type_ = directory_entry::_RefreshSymlink;
+ }
+
+ // FIXME: This is currently broken, and the implementation only a placeholder.
+ // We need to cache last_write_time, file_size, and hard_link_count here before
+ // the implementation actually works.
+
+ return failure_ec;
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_FILESYSTEM