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