//===--------------------- 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 atEnd() const noexcept { return State == PS_AtEnd; } bool inRootDir() const noexcept { return State == PS_InRootDir; } bool inRootName() const noexcept { return State == PS_InRootName; } bool inRootPath() const noexcept { return inRootName() || inRootDir(); } 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(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 ConsumeRootName(PathParser *PP) { static_assert(PathParser::PS_BeforeBegin == 1 && PathParser::PS_InRootName == 2, "Values for enums are incorrect"); while (PP->State <= PathParser::PS_InRootName) ++(*PP); return PP->State == PathParser::PS_AtEnd; } static bool ConsumeRootDir(PathParser* PP) { static_assert(PathParser::PS_BeforeBegin == 1 && PathParser::PS_InRootName == 2 && PathParser::PS_InRootDir == 3, "Values for enums are incorrect"); 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 != "." && 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.inRootName() && PPBase.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 {}; // if n == 0 and (a == end() || a->empty()), returns path("."); otherwise if (ElemCount == 0 && (PP.atEnd() || *PP == "")) 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 static int CompareRootName(PathParser *LHS, PathParser *RHS) { if (!LHS->inRootName() && !RHS->inRootName()) return 0; auto GetRootName = [](PathParser *Parser) -> string_view_t { return Parser->inRootName() ? **Parser : ""; }; int res = GetRootName(LHS).compare(GetRootName(RHS)); ConsumeRootName(LHS); ConsumeRootName(RHS); return res; } static int CompareRootDir(PathParser *LHS, PathParser *RHS) { if (!LHS->inRootDir() && RHS->inRootDir()) return -1; else if (LHS->inRootDir() && !RHS->inRootDir()) return 1; else { ConsumeRootDir(LHS); ConsumeRootDir(RHS); return 0; } } static int CompareRelative(PathParser *LHSPtr, PathParser *RHSPtr) { auto &LHS = *LHSPtr; auto &RHS = *RHSPtr; int res; while (LHS && RHS) { if ((res = (*LHS).compare(*RHS)) != 0) return res; ++LHS; ++RHS; } return 0; } static int CompareEndState(PathParser *LHS, PathParser *RHS) { if (LHS->atEnd() && !RHS->atEnd()) return -1; else if (!LHS->atEnd() && RHS->atEnd()) return 1; return 0; } int path::__compare(string_view_t __s) const { auto LHS = PathParser::CreateBegin(__pn_); auto RHS = PathParser::CreateBegin(__s); int res; if ((res = CompareRootName(&LHS, &RHS)) != 0) return res; if ((res = CompareRootDir(&LHS, &RHS)) != 0) return res; if ((res = CompareRelative(&LHS, &RHS)) != 0) return res; return CompareEndState(&LHS, &RHS); } //////////////////////////////////////////////////////////////////////////// // 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