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 #define NOMINMAX
14 #include <windows.h>
15 #else
16 #include <dirent.h>
17 #endif
18 #include <errno.h>
19
20 #include "filesystem_common.h"
21
22 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
23
24 namespace detail {
25 namespace {
26
27 #if !defined(_LIBCPP_WIN32API)
28
29 #if defined(DT_BLK)
30 template <class DirEntT, class = decltype(DirEntT::d_type)>
get_file_type(DirEntT * ent,int)31 static file_type get_file_type(DirEntT* ent, int) {
32 switch (ent->d_type) {
33 case DT_BLK:
34 return file_type::block;
35 case DT_CHR:
36 return file_type::character;
37 case DT_DIR:
38 return file_type::directory;
39 case DT_FIFO:
40 return file_type::fifo;
41 case DT_LNK:
42 return file_type::symlink;
43 case DT_REG:
44 return file_type::regular;
45 case DT_SOCK:
46 return file_type::socket;
47 // Unlike in lstat, hitting "unknown" here simply means that the underlying
48 // filesystem doesn't support d_type. Report is as 'none' so we correctly
49 // set the cache to empty.
50 case DT_UNKNOWN:
51 break;
52 }
53 return file_type::none;
54 }
55 #endif // defined(DT_BLK)
56
57 template <class DirEntT>
get_file_type(DirEntT * ent,long)58 static file_type get_file_type(DirEntT* ent, long) {
59 return file_type::none;
60 }
61
posix_readdir(DIR * dir_stream,error_code & ec)62 static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
63 error_code& ec) {
64 struct dirent* dir_entry_ptr = nullptr;
65 errno = 0; // zero errno in order to detect errors
66 ec.clear();
67 if ((dir_entry_ptr = ::readdir(dir_stream)) == nullptr) {
68 if (errno)
69 ec = capture_errno();
70 return {};
71 } else {
72 return {dir_entry_ptr->d_name, get_file_type(dir_entry_ptr, 0)};
73 }
74 }
75 #else
76 // defined(_LIBCPP_WIN32API)
77
78 static file_type get_file_type(const WIN32_FIND_DATAW& data) {
79 if (data.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT &&
80 data.dwReserved0 == IO_REPARSE_TAG_SYMLINK)
81 return file_type::symlink;
82 if (data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
83 return file_type::directory;
84 return file_type::regular;
85 }
86 static uintmax_t get_file_size(const WIN32_FIND_DATAW& data) {
87 return (static_cast<uint64_t>(data.nFileSizeHigh) << 32) + data.nFileSizeLow;
88 }
89 static file_time_type get_write_time(const WIN32_FIND_DATAW& data) {
90 ULARGE_INTEGER tmp;
91 const FILETIME& time = data.ftLastWriteTime;
92 tmp.u.LowPart = time.dwLowDateTime;
93 tmp.u.HighPart = time.dwHighDateTime;
94 return file_time_type(file_time_type::duration(tmp.QuadPart));
95 }
96
97 #endif
98
99 } // namespace
100 } // namespace detail
101
102 using detail::ErrorHandler;
103
104 #if defined(_LIBCPP_WIN32API)
105 class __dir_stream {
106 public:
107 __dir_stream() = delete;
108 __dir_stream& operator=(const __dir_stream&) = delete;
109
__dir_stream(__dir_stream && __ds)110 __dir_stream(__dir_stream&& __ds) noexcept : __stream_(__ds.__stream_),
111 __root_(move(__ds.__root_)),
112 __entry_(move(__ds.__entry_)) {
113 __ds.__stream_ = INVALID_HANDLE_VALUE;
114 }
115
__dir_stream(const path & root,directory_options opts,error_code & ec)116 __dir_stream(const path& root, directory_options opts, error_code& ec)
117 : __stream_(INVALID_HANDLE_VALUE), __root_(root) {
118 if (root.native().empty()) {
119 ec = make_error_code(errc::no_such_file_or_directory);
120 return;
121 }
122 __stream_ = ::FindFirstFileW((root / "*").c_str(), &__data_);
123 if (__stream_ == INVALID_HANDLE_VALUE) {
124 ec = detail::make_windows_error(GetLastError());
125 const bool ignore_permission_denied =
126 bool(opts & directory_options::skip_permission_denied);
127 if (ignore_permission_denied &&
128 ec.value() == static_cast<int>(errc::permission_denied))
129 ec.clear();
130 return;
131 }
132 if (!assign())
133 advance(ec);
134 }
135
~__dir_stream()136 ~__dir_stream() noexcept {
137 if (__stream_ == INVALID_HANDLE_VALUE)
138 return;
139 close();
140 }
141
good() const142 bool good() const noexcept { return __stream_ != INVALID_HANDLE_VALUE; }
143
advance(error_code & ec)144 bool advance(error_code& ec) {
145 while (::FindNextFileW(__stream_, &__data_)) {
146 if (assign())
147 return true;
148 }
149 close();
150 return false;
151 }
152
assign()153 bool assign() {
154 if (!wcscmp(__data_.cFileName, L".") || !wcscmp(__data_.cFileName, L".."))
155 return false;
156 // FIXME: Cache more of this
157 //directory_entry::__cached_data cdata;
158 //cdata.__type_ = get_file_type(__data_);
159 //cdata.__size_ = get_file_size(__data_);
160 //cdata.__write_time_ = get_write_time(__data_);
161 __entry_.__assign_iter_entry(
162 __root_ / __data_.cFileName,
163 directory_entry::__create_iter_result(detail::get_file_type(__data_)));
164 return true;
165 }
166
167 private:
close()168 error_code close() noexcept {
169 error_code ec;
170 if (!::FindClose(__stream_))
171 ec = detail::make_windows_error(GetLastError());
172 __stream_ = INVALID_HANDLE_VALUE;
173 return ec;
174 }
175
176 HANDLE __stream_{INVALID_HANDLE_VALUE};
177 WIN32_FIND_DATAW __data_;
178
179 public:
180 path __root_;
181 directory_entry __entry_;
182 };
183 #else
184 class __dir_stream {
185 public:
186 __dir_stream() = delete;
187 __dir_stream& operator=(const __dir_stream&) = delete;
188
__dir_stream(__dir_stream && other)189 __dir_stream(__dir_stream&& other) noexcept : __stream_(other.__stream_),
190 __root_(move(other.__root_)),
191 __entry_(move(other.__entry_)) {
192 other.__stream_ = nullptr;
193 }
194
__dir_stream(const path & root,directory_options opts,error_code & ec)195 __dir_stream(const path& root, directory_options opts, error_code& ec)
196 : __stream_(nullptr), __root_(root) {
197 if ((__stream_ = ::opendir(root.c_str())) == nullptr) {
198 ec = detail::capture_errno();
199 const bool allow_eacess =
200 bool(opts & directory_options::skip_permission_denied);
201 if (allow_eacess && ec.value() == EACCES)
202 ec.clear();
203 return;
204 }
205 advance(ec);
206 }
207
~__dir_stream()208 ~__dir_stream() noexcept {
209 if (__stream_)
210 close();
211 }
212
good() const213 bool good() const noexcept { return __stream_ != nullptr; }
214
advance(error_code & ec)215 bool advance(error_code& ec) {
216 while (true) {
217 auto str_type_pair = detail::posix_readdir(__stream_, ec);
218 auto& str = str_type_pair.first;
219 if (str == "." || str == "..") {
220 continue;
221 } else if (ec || str.empty()) {
222 close();
223 return false;
224 } else {
225 __entry_.__assign_iter_entry(
226 __root_ / str,
227 directory_entry::__create_iter_result(str_type_pair.second));
228 return true;
229 }
230 }
231 }
232
233 private:
close()234 error_code close() noexcept {
235 error_code m_ec;
236 if (::closedir(__stream_) == -1)
237 m_ec = detail::capture_errno();
238 __stream_ = nullptr;
239 return m_ec;
240 }
241
242 DIR* __stream_{nullptr};
243
244 public:
245 path __root_;
246 directory_entry __entry_;
247 };
248 #endif
249
250 // directory_iterator
251
directory_iterator(const path & p,error_code * ec,directory_options opts)252 directory_iterator::directory_iterator(const path& p, error_code* ec,
253 directory_options opts) {
254 ErrorHandler<void> err("directory_iterator::directory_iterator(...)", ec, &p);
255
256 error_code m_ec;
257 __imp_ = make_shared<__dir_stream>(p, opts, m_ec);
258 if (ec)
259 *ec = m_ec;
260 if (!__imp_->good()) {
261 __imp_.reset();
262 if (m_ec)
263 err.report(m_ec);
264 }
265 }
266
__increment(error_code * ec)267 directory_iterator& directory_iterator::__increment(error_code* ec) {
268 _LIBCPP_ASSERT(__imp_, "Attempting to increment an invalid iterator");
269 ErrorHandler<void> err("directory_iterator::operator++()", ec);
270
271 error_code m_ec;
272 if (!__imp_->advance(m_ec)) {
273 path root = move(__imp_->__root_);
274 __imp_.reset();
275 if (m_ec)
276 err.report(m_ec, "at root " PATH_CSTR_FMT, root.c_str());
277 }
278 return *this;
279 }
280
__dereference() const281 directory_entry const& directory_iterator::__dereference() const {
282 _LIBCPP_ASSERT(__imp_, "Attempting to dereference an invalid iterator");
283 return __imp_->__entry_;
284 }
285
286 // recursive_directory_iterator
287
288 struct recursive_directory_iterator::__shared_imp {
289 stack<__dir_stream> __stack_;
290 directory_options __options_;
291 };
292
recursive_directory_iterator(const path & p,directory_options opt,error_code * ec)293 recursive_directory_iterator::recursive_directory_iterator(
294 const path& p, directory_options opt, error_code* ec)
295 : __imp_(nullptr), __rec_(true) {
296 ErrorHandler<void> err("recursive_directory_iterator", ec, &p);
297
298 error_code m_ec;
299 __dir_stream new_s(p, opt, m_ec);
300 if (m_ec)
301 err.report(m_ec);
302 if (m_ec || !new_s.good())
303 return;
304
305 __imp_ = make_shared<__shared_imp>();
306 __imp_->__options_ = opt;
307 __imp_->__stack_.push(move(new_s));
308 }
309
__pop(error_code * ec)310 void recursive_directory_iterator::__pop(error_code* ec) {
311 _LIBCPP_ASSERT(__imp_, "Popping the end iterator");
312 if (ec)
313 ec->clear();
314 __imp_->__stack_.pop();
315 if (__imp_->__stack_.size() == 0)
316 __imp_.reset();
317 else
318 __advance(ec);
319 }
320
options() const321 directory_options recursive_directory_iterator::options() const {
322 return __imp_->__options_;
323 }
324
depth() const325 int recursive_directory_iterator::depth() const {
326 return __imp_->__stack_.size() - 1;
327 }
328
__dereference() const329 const directory_entry& recursive_directory_iterator::__dereference() const {
330 return __imp_->__stack_.top().__entry_;
331 }
332
333 recursive_directory_iterator&
__increment(error_code * ec)334 recursive_directory_iterator::__increment(error_code* ec) {
335 if (ec)
336 ec->clear();
337 if (recursion_pending()) {
338 if (__try_recursion(ec) || (ec && *ec))
339 return *this;
340 }
341 __rec_ = true;
342 __advance(ec);
343 return *this;
344 }
345
__advance(error_code * ec)346 void recursive_directory_iterator::__advance(error_code* ec) {
347 ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
348
349 const directory_iterator end_it;
350 auto& stack = __imp_->__stack_;
351 error_code m_ec;
352 while (stack.size() > 0) {
353 if (stack.top().advance(m_ec))
354 return;
355 if (m_ec)
356 break;
357 stack.pop();
358 }
359
360 if (m_ec) {
361 path root = move(stack.top().__root_);
362 __imp_.reset();
363 err.report(m_ec, "at root " PATH_CSTR_FMT, root.c_str());
364 } else {
365 __imp_.reset();
366 }
367 }
368
__try_recursion(error_code * ec)369 bool recursive_directory_iterator::__try_recursion(error_code* ec) {
370 ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);
371
372 bool rec_sym = bool(options() & directory_options::follow_directory_symlink);
373
374 auto& curr_it = __imp_->__stack_.top();
375
376 bool skip_rec = false;
377 error_code m_ec;
378 if (!rec_sym) {
379 file_status st(curr_it.__entry_.__get_sym_ft(&m_ec));
380 if (m_ec && status_known(st))
381 m_ec.clear();
382 if (m_ec || is_symlink(st) || !is_directory(st))
383 skip_rec = true;
384 } else {
385 file_status st(curr_it.__entry_.__get_ft(&m_ec));
386 if (m_ec && status_known(st))
387 m_ec.clear();
388 if (m_ec || !is_directory(st))
389 skip_rec = true;
390 }
391
392 if (!skip_rec) {
393 __dir_stream new_it(curr_it.__entry_.path(), __imp_->__options_, m_ec);
394 if (new_it.good()) {
395 __imp_->__stack_.push(move(new_it));
396 return true;
397 }
398 }
399 if (m_ec) {
400 const bool allow_eacess =
401 bool(__imp_->__options_ & directory_options::skip_permission_denied);
402 if (m_ec.value() == EACCES && allow_eacess) {
403 if (ec)
404 ec->clear();
405 } else {
406 path at_ent = move(curr_it.__entry_.__p_);
407 __imp_.reset();
408 err.report(m_ec, "attempting recursion into " PATH_CSTR_FMT,
409 at_ent.c_str());
410 }
411 }
412 return false;
413 }
414
415 _LIBCPP_END_NAMESPACE_FILESYSTEM
416