1 // Filesystem directory iterator utilities -*- C++ -*-
2
3 // Copyright (C) 2014-2019 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24
25 #ifndef _GLIBCXX_DIR_COMMON_H
26 #define _GLIBCXX_DIR_COMMON_H 1
27
28 #include <string.h> // strcmp
29 #include <errno.h>
30 #if _GLIBCXX_FILESYSTEM_IS_WINDOWS
31 #include <wchar.h> // wcscmp
32 #endif
33 #ifdef _GLIBCXX_HAVE_DIRENT_H
34 # ifdef _GLIBCXX_HAVE_SYS_TYPES_H
35 # include <sys/types.h>
36 # endif
37 # include <dirent.h>
38 #endif
39
_GLIBCXX_VISIBILITY(default)40 namespace std _GLIBCXX_VISIBILITY(default)
41 {
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
43 namespace filesystem
44 {
45 namespace __gnu_posix
46 {
47 #if _GLIBCXX_FILESYSTEM_IS_WINDOWS
48 // Adapt the Windows _wxxx functions to look like POSIX xxx, but for wchar_t*.
49 using char_type = wchar_t;
50 using DIR = ::_WDIR;
51 using dirent = _wdirent;
52 inline DIR* opendir(const wchar_t* path) { return ::_wopendir(path); }
53 inline dirent* readdir(DIR* dir) { return ::_wreaddir(dir); }
54 inline int closedir(DIR* dir) { return ::_wclosedir(dir); }
55 #elif defined _GLIBCXX_HAVE_DIRENT_H
56 using char_type = char;
57 using DIR = ::DIR;
58 typedef struct ::dirent dirent;
59 using ::opendir;
60 using ::readdir;
61 using ::closedir;
62 #else
63 using char_type = char;
64 struct dirent { const char* d_name; };
65 struct DIR { };
66 inline DIR* opendir(const char*) { return nullptr; }
67 inline dirent* readdir(DIR*) { return nullptr; }
68 inline int closedir(DIR*) { return -1; }
69 #endif
70 } // namespace __gnu_posix
71
72 namespace posix = __gnu_posix;
73
74 struct _Dir_base
75 {
76 _Dir_base(posix::DIR* dirp = nullptr) : dirp(dirp) { }
77
78 // If no error occurs then dirp is non-null,
79 // otherwise null (whether error ignored or not).
80 _Dir_base(const posix::char_type* pathname, bool skip_permission_denied,
81 error_code& ec) noexcept
82 : dirp(posix::opendir(pathname))
83 {
84 if (dirp)
85 ec.clear();
86 else
87 {
88 const int err = errno;
89 if (err == EACCES && skip_permission_denied)
90 ec.clear();
91 else
92 ec.assign(err, std::generic_category());
93 }
94 }
95
96 _Dir_base(_Dir_base&& d) : dirp(std::exchange(d.dirp, nullptr)) { }
97
98 _Dir_base& operator=(_Dir_base&&) = delete;
99
100 ~_Dir_base() { if (dirp) posix::closedir(dirp); }
101
102 const posix::dirent*
103 advance(bool skip_permission_denied, error_code& ec) noexcept
104 {
105 ec.clear();
106
107 int err = std::exchange(errno, 0);
108 const posix::dirent* entp = posix::readdir(dirp);
109 // std::swap cannot be used with Bionic's errno
110 err = std::exchange(errno, err);
111
112 if (entp)
113 {
114 // skip past dot and dot-dot
115 if (is_dot_or_dotdot(entp->d_name))
116 return advance(skip_permission_denied, ec);
117 return entp;
118 }
119 else if (err)
120 {
121 if (err == EACCES && skip_permission_denied)
122 return nullptr;
123 ec.assign(err, std::generic_category());
124 return nullptr;
125 }
126 else
127 {
128 // reached the end
129 return nullptr;
130 }
131 }
132
133 static bool is_dot_or_dotdot(const char* s) noexcept
134 { return !strcmp(s, ".") || !strcmp(s, ".."); }
135
136 #if _GLIBCXX_FILESYSTEM_IS_WINDOWS
137 static bool is_dot_or_dotdot(const wchar_t* s) noexcept
138 { return !wcscmp(s, L".") || !wcscmp(s, L".."); }
139 #endif
140
141 posix::DIR* dirp;
142 };
143
144 inline bool
145 is_permission_denied_error(int e)
146 {
147 if (e == EACCES)
148 return true;
149 #ifdef __APPLE__
150 if (e == EPERM) // See PR 99533
151 return true;
152 #endif
153 return false;
154 }
155
156 } // namespace filesystem
157
158 // BEGIN/END macros must be defined before including this file.
159 _GLIBCXX_BEGIN_NAMESPACE_FILESYSTEM
160
161 inline file_type
162 get_file_type(const std::filesystem::__gnu_posix::dirent& d [[gnu::unused]])
163 {
164 #ifdef _GLIBCXX_HAVE_STRUCT_DIRENT_D_TYPE
165 switch (d.d_type)
166 {
167 case DT_BLK:
168 return file_type::block;
169 case DT_CHR:
170 return file_type::character;
171 case DT_DIR:
172 return file_type::directory;
173 case DT_FIFO:
174 return file_type::fifo;
175 case DT_LNK:
176 return file_type::symlink;
177 case DT_REG:
178 return file_type::regular;
179 case DT_SOCK:
180 return file_type::socket;
181 case DT_UNKNOWN:
182 return file_type::unknown;
183 default:
184 return file_type::none;
185 }
186 #else
187 return file_type::none;
188 #endif
189 }
190 _GLIBCXX_END_NAMESPACE_FILESYSTEM
191
192 _GLIBCXX_END_NAMESPACE_VERSION
193 } // namespace std
194
195 #endif // _GLIBCXX_DIR_COMMON_H
196