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
23namespace detail {
24namespace {
25
26#if !defined(_LIBCPP_WIN32API)
27
28#if defined(DT_BLK)
29template <class DirEntT, class = decltype(DirEntT::d_type)>
30static 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
56template <class DirEntT>
57static file_type get_file_type(DirEntT* ent, long) {
58  return file_type::none;
59}
60
61static 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
76static file_type get_file_type(const WIN32_FIND_DATA& data) {
77  //auto attrs = data.dwFileAttributes;
78  // FIXME(EricWF)
79  return file_type::unknown;
80}
81static uintmax_t get_file_size(const WIN32_FIND_DATA& data) {
82  return (data.nFileSizeHigh * (MAXDWORD + 1)) + data.nFileSizeLow;
83}
84static 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
97using detail::ErrorHandler;
98
99#if defined(_LIBCPP_WIN32API)
100class __dir_stream {
101public:
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
151private:
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
163public:
164  path __root_;
165  directory_entry __entry_;
166};
167#else
168class __dir_stream {
169public:
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
217private:
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
228public:
229  path __root_;
230  directory_entry __entry_;
231};
232#endif
233
234// directory_iterator
235
236directory_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
251directory_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
265directory_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
272struct recursive_directory_iterator::__shared_imp {
273  stack<__dir_stream> __stack_;
274  directory_options __options_;
275};
276
277recursive_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
294void 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
305directory_options recursive_directory_iterator::options() const {
306  return __imp_->__options_;
307}
308
309int recursive_directory_iterator::depth() const {
310  return __imp_->__stack_.size() - 1;
311}
312
313const directory_entry& recursive_directory_iterator::__dereference() const {
314  return __imp_->__stack_.top().__entry_;
315}
316
317recursive_directory_iterator&
318recursive_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
330void 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
353bool 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
399