src/filesystem/directory_iterator.cpp - third_party/libcxx - Git at Google

 //===------------------ directory_iterator.cpp ----------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #include "filesystem"
 #include "__config"
 #if defined(_LIBCPP_WIN32API)
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #else
 #include <dirent.h>
 #endif
 #include <errno.h>

 #include "filesystem_common.h"

 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM

 namespace detail {
 namespace {

 #if !defined(_LIBCPP_WIN32API)

 #if defined(DT_BLK)
 template <class DirEntT, class = decltype(DirEntT::d_type)>
 static file_type get_file_type(DirEntT* ent, int) {
   switch (ent->d_type) {
   case DT_BLK:
     return file_type::block;
   case DT_CHR:
     return file_type::character;
   case DT_DIR:
     return file_type::directory;
   case DT_FIFO:
     return file_type::fifo;
   case DT_LNK:
     return file_type::symlink;
   case DT_REG:
     return file_type::regular;
   case DT_SOCK:
     return file_type::socket;
   // Unlike in lstat, hitting "unknown" here simply means that the underlying
   // filesystem doesn't support d_type. Report is as 'none' so we correctly
   // set the cache to empty.
   case DT_UNKNOWN:
     break;
   }
   return file_type::none;
 }
 #endif // defined(DT_BLK)

 template <class DirEntT>
 static file_type get_file_type(DirEntT* ent, long) {
   return file_type::none;
 }

 static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
                                                   error_code& ec) {
   struct dirent* dir_entry_ptr = nullptr;
   errno = 0; // zero errno in order to detect errors
   ec.clear();
   if ((dir_entry_ptr = ::readdir(dir_stream)) == nullptr) {
     if (errno)
       ec = capture_errno();
     return {};
   } else {
     return {dir_entry_ptr->d_name, get_file_type(dir_entry_ptr, 0)};
   }
 }
 #else

 static file_type get_file_type(const WIN32_FIND_DATA& data) {
   //auto attrs = data.dwFileAttributes;
   // FIXME(EricWF)
   return file_type::unknown;
 }
 static uintmax_t get_file_size(const WIN32_FIND_DATA& data) {
   return (data.nFileSizeHigh * (MAXDWORD + 1)) + data.nFileSizeLow;
 }
 static file_time_type get_write_time(const WIN32_FIND_DATA& data) {
   ULARGE_INTEGER tmp;
   const FILETIME& time = data.ftLastWriteTime;
   tmp.u.LowPart = time.dwLowDateTime;
   tmp.u.HighPart = time.dwHighDateTime;
   return file_time_type(file_time_type::duration(tmp.QuadPart));
 }

 #endif

 } // namespace
 } // namespace detail

 using detail::ErrorHandler;

 #if defined(_LIBCPP_WIN32API)
 class __dir_stream {
 public:
   __dir_stream() = delete;
   __dir_stream& operator=(const __dir_stream&) = delete;

   __dir_stream(__dir_stream&& __ds) noexcept : __stream_(__ds.__stream_),
                                                __root_(move(__ds.__root_)),
                                                __entry_(move(__ds.__entry_)) {
     __ds.__stream_ = INVALID_HANDLE_VALUE;
   }

   __dir_stream(const path& root, directory_options opts, error_code& ec)
       : __stream_(INVALID_HANDLE_VALUE), __root_(root) {
     __stream_ = ::FindFirstFile(root.c_str(), &__data_);
     if (__stream_ == INVALID_HANDLE_VALUE) {
       ec = error_code(::GetLastError(), generic_category());
       const bool ignore_permission_denied =
           bool(opts & directory_options::skip_permission_denied);
       if (ignore_permission_denied && ec.value() == ERROR_ACCESS_DENIED)
         ec.clear();
       return;
     }
   }

   ~__dir_stream() noexcept {
     if (__stream_ == INVALID_HANDLE_VALUE)
       return;
     close();
   }

   bool good() const noexcept { return __stream_ != INVALID_HANDLE_VALUE; }

   bool advance(error_code& ec) {
     while (::FindNextFile(__stream_, &__data_)) {
       if (!strcmp(__data_.cFileName, ".") || strcmp(__data_.cFileName, ".."))
         continue;
       // FIXME: Cache more of this
       //directory_entry::__cached_data cdata;
       //cdata.__type_ = get_file_type(__data_);
       //cdata.__size_ = get_file_size(__data_);
       //cdata.__write_time_ = get_write_time(__data_);
       __entry_.__assign_iter_entry(
           __root_ / __data_.cFileName,
           directory_entry::__create_iter_result(detail::get_file_type(__data)));
       return true;
     }
     ec = error_code(::GetLastError(), generic_category());
     close();
     return false;
   }

 private:
   error_code close() noexcept {
     error_code ec;
     if (!::FindClose(__stream_))
       ec = error_code(::GetLastError(), generic_category());
     __stream_ = INVALID_HANDLE_VALUE;
     return ec;
   }

   HANDLE __stream_{INVALID_HANDLE_VALUE};
   WIN32_FIND_DATA __data_;

 public:
   path __root_;
   directory_entry __entry_;
 };
 #else
 class __dir_stream {
 public:
   __dir_stream() = delete;
   __dir_stream& operator=(const __dir_stream&) = delete;

   __dir_stream(__dir_stream&& other) noexcept : __stream_(other.__stream_),
                                                 __root_(move(other.__root_)),
                                                 __entry_(move(other.__entry_)) {
     other.__stream_ = nullptr;
   }

   __dir_stream(const path& root, directory_options opts, error_code& ec)
       : __stream_(nullptr), __root_(root) {
     if ((__stream_ = ::opendir(root.c_str())) == nullptr) {
       ec = detail::capture_errno();
       const bool allow_eacess =
           bool(opts & directory_options::skip_permission_denied);
       if (allow_eacess && ec.value() == EACCES)
         ec.clear();
       return;
     }
     advance(ec);
   }

   ~__dir_stream() noexcept {
     if (__stream_)
       close();
   }

   bool good() const noexcept { return __stream_ != nullptr; }

   bool advance(error_code& ec) {
     while (true) {
       auto str_type_pair = detail::posix_readdir(__stream_, ec);
       auto& str = str_type_pair.first;
       if (str == "." || str == "..") {
         continue;
       } else if (ec || str.empty()) {
         close();
         return false;
       } else {
         __entry_.__assign_iter_entry(
             __root_ / str,
             directory_entry::__create_iter_result(str_type_pair.second));
         return true;
       }
     }
   }

 private:
   error_code close() noexcept {
     error_code m_ec;
     if (::closedir(__stream_) == -1)
       m_ec = detail::capture_errno();
     __stream_ = nullptr;
     return m_ec;
   }

   DIR* __stream_{nullptr};

 public:
   path __root_;
   directory_entry __entry_;
 };
 #endif

 // directory_iterator

 directory_iterator::directory_iterator(const path& p, error_code* ec,
                                        directory_options opts) {
   ErrorHandler<void> err("directory_iterator::directory_iterator(...)", ec, &p);

   error_code m_ec;
   __imp_ = make_shared<__dir_stream>(p, opts, m_ec);
   if (ec)
     *ec = m_ec;
   if (!__imp_->good()) {
     __imp_.reset();
     if (m_ec)
       err.report(m_ec);
   }
 }

 directory_iterator& directory_iterator::__increment(error_code* ec) {
   _LIBCPP_ASSERT(__imp_, "Attempting to increment an invalid iterator");
   ErrorHandler<void> err("directory_iterator::operator++()", ec);

   error_code m_ec;
   if (!__imp_->advance(m_ec)) {
     path root = move(__imp_->__root_);
     __imp_.reset();
     if (m_ec)
       err.report(m_ec, "at root \"%s\"", root);
   }
   return *this;
 }

 directory_entry const& directory_iterator::__dereference() const {
   _LIBCPP_ASSERT(__imp_, "Attempting to dereference an invalid iterator");
   return __imp_->__entry_;
 }

 // recursive_directory_iterator

 struct recursive_directory_iterator::__shared_imp {
   stack<__dir_stream> __stack_;
   directory_options __options_;
 };

 recursive_directory_iterator::recursive_directory_iterator(
     const path& p, directory_options opt, error_code* ec)
     : __imp_(nullptr), __rec_(true) {
   ErrorHandler<void> err("recursive_directory_iterator", ec, &p);

   error_code m_ec;
   __dir_stream new_s(p, opt, m_ec);
   if (m_ec)
     err.report(m_ec);
   if (m_ec || !new_s.good())
     return;

   __imp_ = make_shared<__shared_imp>();
   __imp_->__options_ = opt;
   __imp_->__stack_.push(move(new_s));
 }

 void recursive_directory_iterator::__pop(error_code* ec) {
   _LIBCPP_ASSERT(__imp_, "Popping the end iterator");
   if (ec)
     ec->clear();
   __imp_->__stack_.pop();
   if (__imp_->__stack_.size() == 0)
     __imp_.reset();
   else
     __advance(ec);
 }

 directory_options recursive_directory_iterator::options() const {
   return __imp_->__options_;
 }

 int recursive_directory_iterator::depth() const {
   return __imp_->__stack_.size() - 1;
 }

 const directory_entry& recursive_directory_iterator::__dereference() const {
   return __imp_->__stack_.top().__entry_;
 }

 recursive_directory_iterator&
 recursive_directory_iterator::__increment(error_code* ec) {
   if (ec)
     ec->clear();
   if (recursion_pending()) {
     if (__try_recursion(ec) || (ec && *ec))
       return *this;
   }
   __rec_ = true;
   __advance(ec);
   return *this;
 }

 void recursive_directory_iterator::__advance(error_code* ec) {
   ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);

   const directory_iterator end_it;
   auto& stack = __imp_->__stack_;
   error_code m_ec;
   while (stack.size() > 0) {
     if (stack.top().advance(m_ec))
       return;
     if (m_ec)
       break;
     stack.pop();
   }

   if (m_ec) {
     path root = move(stack.top().__root_);
     __imp_.reset();
     err.report(m_ec, "at root \"%s\"", root);
   } else {
     __imp_.reset();
   }
 }

 bool recursive_directory_iterator::__try_recursion(error_code* ec) {
   ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);

   bool rec_sym = bool(options() & directory_options::follow_directory_symlink);

   auto& curr_it = __imp_->__stack_.top();

   bool skip_rec = false;
   error_code m_ec;
   if (!rec_sym) {
     file_status st(curr_it.__entry_.__get_sym_ft(&m_ec));
     if (m_ec && status_known(st))
       m_ec.clear();
     if (m_ec || is_symlink(st) || !is_directory(st))
       skip_rec = true;
   } else {
     file_status st(curr_it.__entry_.__get_ft(&m_ec));
     if (m_ec && status_known(st))
       m_ec.clear();
     if (m_ec || !is_directory(st))
       skip_rec = true;
   }

   if (!skip_rec) {
     __dir_stream new_it(curr_it.__entry_.path(), __imp_->__options_, m_ec);
     if (new_it.good()) {
       __imp_->__stack_.push(move(new_it));
       return true;
     }
   }
   if (m_ec) {
     const bool allow_eacess =
         bool(__imp_->__options_ & directory_options::skip_permission_denied);
     if (m_ec.value() == EACCES && allow_eacess) {
       if (ec)
         ec->clear();
     } else {
       path at_ent = move(curr_it.__entry_.__p_);
       __imp_.reset();
       err.report(m_ec, "attempting recursion into \"%s\"", at_ent);
     }
   }
   return false;
 }

 _LIBCPP_END_NAMESPACE_FILESYSTEM
	//===------------------ directory_iterator.cpp ----------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#include "filesystem"
	#include "__config"
	#if defined(_LIBCPP_WIN32API)
	#define WIN32_LEAN_AND_MEAN
	#include <windows.h>
	#else
	#include <dirent.h>
	#endif
	#include <errno.h>

	#include "filesystem_common.h"

	_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM

	namespace detail {
	namespace {

	#if !defined(_LIBCPP_WIN32API)

	#if defined(DT_BLK)
	template <class DirEntT, class = decltype(DirEntT::d_type)>
	static file_type get_file_type(DirEntT* ent, int) {
	switch (ent->d_type) {
	case DT_BLK:
	return file_type::block;
	case DT_CHR:
	return file_type::character;
	case DT_DIR:
	return file_type::directory;
	case DT_FIFO:
	return file_type::fifo;
	case DT_LNK:
	return file_type::symlink;
	case DT_REG:
	return file_type::regular;
	case DT_SOCK:
	return file_type::socket;
	// Unlike in lstat, hitting "unknown" here simply means that the underlying
	// filesystem doesn't support d_type. Report is as 'none' so we correctly
	// set the cache to empty.
	case DT_UNKNOWN:
	break;
	}
	return file_type::none;
	}
	#endif // defined(DT_BLK)

	template <class DirEntT>
	static file_type get_file_type(DirEntT* ent, long) {
	return file_type::none;
	}

	static pair<string_view, file_type> posix_readdir(DIR* dir_stream,
	error_code& ec) {
	struct dirent* dir_entry_ptr = nullptr;
	errno = 0; // zero errno in order to detect errors
	ec.clear();
	if ((dir_entry_ptr = ::readdir(dir_stream)) == nullptr) {
	if (errno)
	ec = capture_errno();
	return {};
	} else {
	return {dir_entry_ptr->d_name, get_file_type(dir_entry_ptr, 0)};
	}
	}
	#else

	static file_type get_file_type(const WIN32_FIND_DATA& data) {
	//auto attrs = data.dwFileAttributes;
	// FIXME(EricWF)
	return file_type::unknown;
	}
	static uintmax_t get_file_size(const WIN32_FIND_DATA& data) {
	return (data.nFileSizeHigh * (MAXDWORD + 1)) + data.nFileSizeLow;
	}
	static file_time_type get_write_time(const WIN32_FIND_DATA& data) {
	ULARGE_INTEGER tmp;
	const FILETIME& time = data.ftLastWriteTime;
	tmp.u.LowPart = time.dwLowDateTime;
	tmp.u.HighPart = time.dwHighDateTime;
	return file_time_type(file_time_type::duration(tmp.QuadPart));
	}

	#endif

	} // namespace
	} // namespace detail

	using detail::ErrorHandler;

	#if defined(_LIBCPP_WIN32API)
	class __dir_stream {
	public:
	__dir_stream() = delete;
	__dir_stream& operator=(const __dir_stream&) = delete;

	__dir_stream(__dir_stream&& __ds) noexcept : __stream_(__ds.__stream_),
	__root_(move(__ds.__root_)),
	__entry_(move(__ds.__entry_)) {
	__ds.__stream_ = INVALID_HANDLE_VALUE;
	}

	__dir_stream(const path& root, directory_options opts, error_code& ec)
	: __stream_(INVALID_HANDLE_VALUE), __root_(root) {
	__stream_ = ::FindFirstFile(root.c_str(), &__data_);
	if (__stream_ == INVALID_HANDLE_VALUE) {
	ec = error_code(::GetLastError(), generic_category());
	const bool ignore_permission_denied =
	bool(opts & directory_options::skip_permission_denied);
	if (ignore_permission_denied && ec.value() == ERROR_ACCESS_DENIED)
	ec.clear();
	return;
	}
	}

	~__dir_stream() noexcept {
	if (__stream_ == INVALID_HANDLE_VALUE)
	return;
	close();
	}

	bool good() const noexcept { return __stream_ != INVALID_HANDLE_VALUE; }

	bool advance(error_code& ec) {
	while (::FindNextFile(__stream_, &__data_)) {
	if (!strcmp(__data_.cFileName, ".") \|\| strcmp(__data_.cFileName, ".."))
	continue;
	// FIXME: Cache more of this
	//directory_entry::__cached_data cdata;
	//cdata.__type_ = get_file_type(__data_);
	//cdata.__size_ = get_file_size(__data_);
	//cdata.__write_time_ = get_write_time(__data_);
	__entry_.__assign_iter_entry(
	__root_ / __data_.cFileName,
	directory_entry::__create_iter_result(detail::get_file_type(__data)));
	return true;
	}
	ec = error_code(::GetLastError(), generic_category());
	close();
	return false;
	}

	private:
	error_code close() noexcept {
	error_code ec;
	if (!::FindClose(__stream_))
	ec = error_code(::GetLastError(), generic_category());
	__stream_ = INVALID_HANDLE_VALUE;
	return ec;
	}

	HANDLE __stream_{INVALID_HANDLE_VALUE};
	WIN32_FIND_DATA __data_;

	public:
	path __root_;
	directory_entry __entry_;
	};
	#else
	class __dir_stream {
	public:
	__dir_stream() = delete;
	__dir_stream& operator=(const __dir_stream&) = delete;

	__dir_stream(__dir_stream&& other) noexcept : __stream_(other.__stream_),
	__root_(move(other.__root_)),
	__entry_(move(other.__entry_)) {
	other.__stream_ = nullptr;
	}

	__dir_stream(const path& root, directory_options opts, error_code& ec)
	: __stream_(nullptr), __root_(root) {
	if ((__stream_ = ::opendir(root.c_str())) == nullptr) {
	ec = detail::capture_errno();
	const bool allow_eacess =
	bool(opts & directory_options::skip_permission_denied);
	if (allow_eacess && ec.value() == EACCES)
	ec.clear();
	return;
	}
	advance(ec);
	}

	~__dir_stream() noexcept {
	if (__stream_)
	close();
	}

	bool good() const noexcept { return __stream_ != nullptr; }

	bool advance(error_code& ec) {
	while (true) {
	auto str_type_pair = detail::posix_readdir(__stream_, ec);
	auto& str = str_type_pair.first;
	if (str == "." \|\| str == "..") {
	continue;
	} else if (ec \|\| str.empty()) {
	close();
	return false;
	} else {
	__entry_.__assign_iter_entry(
	__root_ / str,
	directory_entry::__create_iter_result(str_type_pair.second));
	return true;
	}
	}
	}

	private:
	error_code close() noexcept {
	error_code m_ec;
	if (::closedir(__stream_) == -1)
	m_ec = detail::capture_errno();
	__stream_ = nullptr;
	return m_ec;
	}

	DIR* __stream_{nullptr};

	public:
	path __root_;
	directory_entry __entry_;
	};
	#endif

	// directory_iterator

	directory_iterator::directory_iterator(const path& p, error_code* ec,
	directory_options opts) {
	ErrorHandler<void> err("directory_iterator::directory_iterator(...)", ec, &p);

	error_code m_ec;
	__imp_ = make_shared<__dir_stream>(p, opts, m_ec);
	if (ec)
	*ec = m_ec;
	if (!__imp_->good()) {
	__imp_.reset();
	if (m_ec)
	err.report(m_ec);
	}
	}

	directory_iterator& directory_iterator::__increment(error_code* ec) {
	_LIBCPP_ASSERT(__imp_, "Attempting to increment an invalid iterator");
	ErrorHandler<void> err("directory_iterator::operator++()", ec);

	error_code m_ec;
	if (!__imp_->advance(m_ec)) {
	path root = move(__imp_->__root_);
	__imp_.reset();
	if (m_ec)
	err.report(m_ec, "at root \"%s\"", root);
	}
	return *this;
	}

	directory_entry const& directory_iterator::__dereference() const {
	_LIBCPP_ASSERT(__imp_, "Attempting to dereference an invalid iterator");
	return __imp_->__entry_;
	}

	// recursive_directory_iterator

	struct recursive_directory_iterator::__shared_imp {
	stack<__dir_stream> __stack_;
	directory_options __options_;
	};

	recursive_directory_iterator::recursive_directory_iterator(
	const path& p, directory_options opt, error_code* ec)
	: __imp_(nullptr), __rec_(true) {
	ErrorHandler<void> err("recursive_directory_iterator", ec, &p);

	error_code m_ec;
	__dir_stream new_s(p, opt, m_ec);
	if (m_ec)
	err.report(m_ec);
	if (m_ec \|\| !new_s.good())
	return;

	__imp_ = make_shared<__shared_imp>();
	__imp_->__options_ = opt;
	__imp_->__stack_.push(move(new_s));
	}

	void recursive_directory_iterator::__pop(error_code* ec) {
	_LIBCPP_ASSERT(__imp_, "Popping the end iterator");
	if (ec)
	ec->clear();
	__imp_->__stack_.pop();
	if (__imp_->__stack_.size() == 0)
	__imp_.reset();
	else
	__advance(ec);
	}

	directory_options recursive_directory_iterator::options() const {
	return __imp_->__options_;
	}

	int recursive_directory_iterator::depth() const {
	return __imp_->__stack_.size() - 1;
	}

	const directory_entry& recursive_directory_iterator::__dereference() const {
	return __imp_->__stack_.top().__entry_;
	}

	recursive_directory_iterator&
	recursive_directory_iterator::__increment(error_code* ec) {
	if (ec)
	ec->clear();
	if (recursion_pending()) {
	if (__try_recursion(ec) \|\| (ec && *ec))
	return *this;
	}
	__rec_ = true;
	__advance(ec);
	return *this;
	}

	void recursive_directory_iterator::__advance(error_code* ec) {
	ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);

	const directory_iterator end_it;
	auto& stack = __imp_->__stack_;
	error_code m_ec;
	while (stack.size() > 0) {
	if (stack.top().advance(m_ec))
	return;
	if (m_ec)
	break;
	stack.pop();
	}

	if (m_ec) {
	path root = move(stack.top().__root_);
	__imp_.reset();
	err.report(m_ec, "at root \"%s\"", root);
	} else {
	__imp_.reset();
	}
	}

	bool recursive_directory_iterator::__try_recursion(error_code* ec) {
	ErrorHandler<void> err("recursive_directory_iterator::operator++()", ec);

	bool rec_sym = bool(options() & directory_options::follow_directory_symlink);

	auto& curr_it = __imp_->__stack_.top();

	bool skip_rec = false;
	error_code m_ec;
	if (!rec_sym) {
	file_status st(curr_it.__entry_.__get_sym_ft(&m_ec));
	if (m_ec && status_known(st))
	m_ec.clear();
	if (m_ec \|\| is_symlink(st) \|\| !is_directory(st))
	skip_rec = true;
	} else {
	file_status st(curr_it.__entry_.__get_ft(&m_ec));
	if (m_ec && status_known(st))
	m_ec.clear();
	if (m_ec \|\| !is_directory(st))
	skip_rec = true;
	}

	if (!skip_rec) {
	__dir_stream new_it(curr_it.__entry_.path(), __imp_->__options_, m_ec);
	if (new_it.good()) {
	__imp_->__stack_.push(move(new_it));
	return true;
	}
	}
	if (m_ec) {
	const bool allow_eacess =
	bool(__imp_->__options_ & directory_options::skip_permission_denied);
	if (m_ec.value() == EACCES && allow_eacess) {
	if (ec)
	ec->clear();
	} else {
	path at_ent = move(curr_it.__entry_.__p_);
	__imp_.reset();
	err.report(m_ec, "attempting recursion into \"%s\"", at_ent);
	}
	}
	return false;
	}

	_LIBCPP_END_NAMESPACE_FILESYSTEM