libcxx/src/filesystem/directory_iterator.cpp

   1 //===------------------ directory_iterator.cpp ----------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "filesystem"
  10 #include "__config"
  11 #if defined(_LIBCPP_WIN32API)
  12 #define WIN32_LEAN_AND_MEAN
  13 #include <windows.h>
  14 #else
  15 #include <dirent.h>
  16 #endif
  17 #include <errno.h>
  18
  19 #include "filesystem_common.h"
  20
  21 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
  22
  23 namespace detail {
  24 namespace {
  25
  26 #if !defined(_LIBCPP_WIN32API)
  27
  28 #if defined(DT_BLK)
  29 template <class DirEntT, class = decltype(DirEntT::d_type)>
  30 static file_type get_file_type(DirEntT* ent, int) {
  31   switch (ent->d_type) {
  32   case DT_BLK:
  33     return file_type::block;
  34   case DT_CHR:
  35     return file_type::character;
  36   case DT_DIR:
  37     return file_type::directory;
  38   case DT_FIFO:
  39     return file_type::fifo;
  40   case DT_LNK:
  41     return file_type::symlink;
  42   case DT_REG:
  43     return file_type::regular;
  44   case DT_SOCK:
  45     return file_type::socket;
  46   // Unlike in lstat, hitting "unknown" here simply means that the underlying
  47   // filesystem doesn't support d_type. Report is as 'none' so we correctly
  48   // set the cache to empty.
  49   case DT_UNKNOWN:
  50     break;
  51   }
  52   return file_type::none;
  53 }
  54 #endif // defined(DT_BLK)
  55
  56 template <class DirEntT>
  57 static file_type get_file_type(DirEntT* ent, long) {
  58   return file_type::none;
  59 }
  60
  61 static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
  62                                                   error_code& ec) {
  63   struct dirent* dir_entry_ptr = nullptr;
  64   errno = 0; // zero errno in order to detect errors
  65   ec.clear();
  66   if ((dir_entry_ptr = ::readdir(dir_stream)) == nullptr) {
  67     if (errno)
  68       ec = capture_errno();
  69     return {};
  70   } else {
  71     return {dir_entry_ptr->d_name, get_file_type(dir_entry_ptr, 0)};
  72   }
  73 }
  74 #else
  75
  76 static file_type get_file_type(const WIN32_FIND_DATA& data) {
  77   //auto attrs = data.dwFileAttributes;
  78   // FIXME(EricWF)
  79   return file_type::unknown;
  80 }
  81 static uintmax_t get_file_size(const WIN32_FIND_DATA& data) {
  82   return (data.nFileSizeHigh * (MAXDWORD + 1)) + data.nFileSizeLow;
  83 }
  84 static file_time_type get_write_time(const WIN32_FIND_DATA& data) {
  85   ULARGE_INTEGER tmp;
  86   const FILETIME& time = data.ftLastWriteTime;
  87   tmp.u.LowPart = time.dwLowDateTime;
  88   tmp.u.HighPart = time.dwHighDateTime;
  89   return file_time_type(file_time_type::duration(tmp.QuadPart));
  90 }
  91
  92 #endif
  93
  94 } // namespace
  95 } // namespace detail
  96
  97 using detail::ErrorHandler;
  98
  99 #if defined(_LIBCPP_WIN32API)
 100 class __dir_stream {
 101 public:
 102   __dir_stream() = delete;
 103   __dir_stream& operator=(const __dir_stream&) = delete;
 104
 105   __dir_stream(__dir_stream&& __ds) noexcept : __stream_(__ds.__stream_),
 106                                                __root_(move(__ds.__root_)),
 107                                                __entry_(move(__ds.__entry_)) {
 108     __ds.__stream_ = INVALID_HANDLE_VALUE;
 109   }
 110
 111   __dir_stream(const path& root, directory_options opts, error_code& ec)
 112       : __stream_(INVALID_HANDLE_VALUE), __root_(root) {
 113     __stream_ = ::FindFirstFile(root.c_str(), &__data_);
 114     if (__stream_ == INVALID_HANDLE_VALUE) {
 115       ec = error_code(::GetLastError(), generic_category());
 116       const bool ignore_permission_denied =
 117           bool(opts & directory_options::skip_permission_denied);
 118       if (ignore_permission_denied && ec.value() == ERROR_ACCESS_DENIED)
 119         ec.clear();
 120       return;
 121     }
 122   }
 123
 124   ~__dir_stream() noexcept {
 125     if (__stream_ == INVALID_HANDLE_VALUE)
 126       return;
 127     close();
 128   }
 129
 130   bool good() const noexcept { return __stream_ != INVALID_HANDLE_VALUE; }
 131
 132   bool advance(error_code& ec) {
 133     while (::FindNextFile(__stream_, &__data_)) {
 134       if (!strcmp(__data_.cFileName, ".") || strcmp(__data_.cFileName, ".."))
 135         continue;
 136       // FIXME: Cache more of this
 137       //directory_entry::__cached_data cdata;
 138       //cdata.__type_ = get_file_type(__data_);
 139       //cdata.__size_ = get_file_size(__data_);
 140       //cdata.__write_time_ = get_write_time(__data_);
 141       __entry_.__assign_iter_entry(
 142           __root_ / __data_.cFileName,
 143           directory_entry::__create_iter_result(detail::get_file_type(__data)));
 144       return true;
 145     }
 146     ec = error_code(::GetLastError(), generic_category());
 147     close();
 148     return false;
 149   }
 150
 151 private:
 152   error_code close() noexcept {
 153     error_code ec;
 154     if (!::FindClose(__stream_))
 155       ec = error_code(::GetLastError(), generic_category());
 156     __stream_ = INVALID_HANDLE_VALUE;
 157     return ec;
 158   }
 159
 160   HANDLE __stream_{INVALID_HANDLE_VALUE};
 161   WIN32_FIND_DATA __data_;
 162
 163 public:
 164   path __root_;
 165   directory_entry __entry_;
 166 };
 167 #else
 168 class __dir_stream {
 169 public:
 170   __dir_stream() = delete;
 171   __dir_stream& operator=(const __dir_stream&) = delete;
 172
 173   __dir_stream(__dir_stream&& other) noexcept : __stream_(other.__stream_),
 174                                                 __root_(move(other.__root_)),
 175                                                 __entry_(move(other.__entry_)) {
 176     other.__stream_ = nullptr;
 177   }
 178
 179   __dir_stream(const path& root, directory_options opts, error_code& ec)
 180       : __stream_(nullptr), __root_(root) {
 181     if ((__stream_ = ::opendir(root.c_str())) == nullptr) {
 182       ec = detail::capture_errno();
 183       const bool allow_eacess =
 184           bool(opts & directory_options::skip_permission_denied);
 185       if (allow_eacess && ec.value() == EACCES)
 186         ec.clear();
 187       return;
 188     }
 189     advance(ec);
 190   }
 191
 192   ~__dir_stream() noexcept {
 193     if (__stream_)
 194       close();
 195   }
 196
 197   bool good() const noexcept { return __stream_ != nullptr; }
 198
 199   bool advance(error_code& ec) {
 200     while (true) {
 201       auto str_type_pair = detail::posix_readdir(__stream_, ec);
 202       auto& str = str_type_pair.first;
 203       if (str == "." || str == "..") {
 204         continue;
 205       } else if (ec || str.empty()) {
 206         close();
 207         return false;
 208       } else {
 209         __entry_.__assign_iter_entry(
 210             __root_ / str,
 211             directory_entry::__create_iter_result(str_type_pair.second));
 212         return true;
 213       }
 214     }
 215   }
 216
 217 private:
 218   error_code close() noexcept {
 219     error_code m_ec;
 220     if (::closedir(__stream_) == -1)
 221       m_ec = detail::capture_errno();
 222     __stream_ = nullptr;
 223     return m_ec;
 224   }
 225
 226   DIR* __stream_{nullptr};
 227
 228 public:
 229   path __root_;
 230   directory_entry __entry_;
 231 };
 232 #endif
 233
 234 // directory_iterator
 235
 236 directory_iterator::directory_iterator(const path& p, error_code* ec,
 237                                        directory_options opts) {
 238   ErrorHandler<void> err("directory_iterator::directory_iterator(...)", ec, &p);
 239
 240   error_code m_ec;
 241   __imp_ = make_shared<__dir_stream>(p, opts, m_ec);
 242   if (ec)
 243     *ec = m_ec;
 244   if (!__imp_->good()) {
 245     __imp_.reset();
 246     if (m_ec)
 247       err.report(m_ec);
 248   }
 249 }
 250
 251 directory_iterator& directory_iterator::__increment(error_code* ec) {
 252   _LIBCPP_ASSERT(__imp_, "Attempting to increment an invalid iterator");
 253   ErrorHandler<void> err("directory_iterator::operator++()", ec);
 254
 255   error_code m_ec;
 256   if (!__imp_->advance(m_ec)) {
 257     path root = move(__imp_->__root_);
 258     __imp_.reset();
 259     if (m_ec)
 260       err.report(m_ec, "at root \"%s\"", root);
 261   }
 262   return *this;
 263 }
 264
 265 directory_entry const& directory_iterator::__dereference() const {
 266   _LIBCPP_ASSERT(__imp_, "Attempting to dereference an invalid iterator");
 267   return __imp_->__entry_;
 268 }
 269
 270 // recursive_directory_iterator
 271
 272 struct recursive_directory_iterator::__shared_imp {
 273   stack<__dir_stream> __stack_;
 274   directory_options __options_;
 275 };
 276
 277 recursive_directory_iterator::recursive_directory_iterator(
 278     const path& p, directory_options opt, error_code* ec)
 279     : __imp_(nullptr), __rec_(true) {
 280   ErrorHandler<void> err("recursive_directory_iterator", ec, &p);
 281
 282   error_code m_ec;
 283   __dir_stream new_s(p, opt, m_ec);
 284   if (m_ec)
 285     err.report(m_ec);
 286   if (m_ec || !new_s.good())
 287     return;
 288
 289   __imp_ = make_shared<__shared_imp>();
 290   __imp_->__options_ = opt;
 291   __imp_->__stack_.push(move(new_s));
 292 }
 293
 294 void recursive_directory_iterator::__pop(error_code* ec) {
 295   _LIBCPP_ASSERT(__imp_, "Popping the end iterator");
 296   if (ec)
 297     ec->clear();
 298   __imp_->__stack_.pop();
 299   if (__imp_->__stack_.size() == 0)
 300     __imp_.reset();
 301   else
 302     __advance(ec);
 303 }
 304
 305 directory_options recursive_directory_iterator::options() const {
 306   return __imp_->__options_;
 307 }
 308
 309 int recursive_directory_iterator::depth() const {
 310   return __imp_->__stack_.size() - 1;
 311 }
 312
 313 const directory_entry& recursive_directory_iterator::__dereference() const {
 314   return __imp_->__stack_.top().__entry_;
 315 }
 316
 317 recursive_directory_iterator&
 318 recursive_directory_iterator::__increment(error_code* ec) {
 319   if (ec)
 320     ec->clear();
 321   if (recursion_pending()) {
 322     if (__try_recursion(ec) || (ec && *ec))
 323       return *this;
 324   }
 325   __rec_ = true;
 326   __advance(ec);
 327   return *this;
 328 }
 329
 330 void recursive_directory_iterator::__advance(error_code* ec) {
 331   ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
 332
 333   const directory_iterator end_it;
 334   auto& stack = __imp_->__stack_;
 335   error_code m_ec;
 336   while (stack.size() > 0) {
 337     if (stack.top().advance(m_ec))
 338       return;
 339     if (m_ec)
 340       break;
 341     stack.pop();
 342   }
 343
 344   if (m_ec) {
 345     path root = move(stack.top().__root_);
 346     __imp_.reset();
 347     err.report(m_ec, "at root \"%s\"", root);
 348   } else {
 349     __imp_.reset();
 350   }
 351 }
 352
 353 bool recursive_directory_iterator::__try_recursion(error_code* ec) {
 354   ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
 355
 356   bool rec_sym = bool(options() & directory_options::follow_directory_symlink);
 357
 358   auto& curr_it = __imp_->__stack_.top();
 359
 360   bool skip_rec = false;
 361   error_code m_ec;
 362   if (!rec_sym) {
 363     file_status st(curr_it.__entry_.__get_sym_ft(&m_ec));
 364     if (m_ec && status_known(st))
 365       m_ec.clear();
 366     if (m_ec || is_symlink(st) || !is_directory(st))
 367       skip_rec = true;
 368   } else {
 369     file_status st(curr_it.__entry_.__get_ft(&m_ec));
 370     if (m_ec && status_known(st))
 371       m_ec.clear();
 372     if (m_ec || !is_directory(st))
 373       skip_rec = true;
 374   }
 375
 376   if (!skip_rec) {
 377     __dir_stream new_it(curr_it.__entry_.path(), __imp_->__options_, m_ec);
 378     if (new_it.good()) {
 379       __imp_->__stack_.push(move(new_it));
 380       return true;
 381     }
 382   }
 383   if (m_ec) {
 384     const bool allow_eacess =
 385         bool(__imp_->__options_ & directory_options::skip_permission_denied);
 386     if (m_ec.value() == EACCES && allow_eacess) {
 387       if (ec)
 388         ec->clear();
 389     } else {
 390       path at_ent = move(curr_it.__entry_.__p_);
 391       __imp_.reset();
 392       err.report(m_ec, "attempting recursion into \"%s\"", at_ent);
 393     }
 394   }
 395   return false;
 396 }
 397
 398 _LIBCPP_END_NAMESPACE_FILESYSTEM