1 /*
2 A C++ interface to POSIX functions.
3
4 Copyright (c) 2012 - 2016, Victor Zverovich
5 All rights reserved.
6
7 For the license information refer to format.h.
8 */
9
10 // Disable bogus MSVC warnings.
11 #ifndef _CRT_SECURE_NO_WARNINGS
12 # define _CRT_SECURE_NO_WARNINGS
13 #endif
14
15 #include "posix.h"
16
17 #include <limits.h>
18 #include <sys/types.h>
19 #include <sys/stat.h>
20
21 #ifndef _WIN32
22 # include <unistd.h>
23 #else
24 # include <windows.h>
25 # include <io.h>
26
27 # define O_CREAT _O_CREAT
28 # define O_TRUNC _O_TRUNC
29
30 # ifndef S_IRUSR
31 # define S_IRUSR _S_IREAD
32 # endif
33
34 # ifndef S_IWUSR
35 # define S_IWUSR _S_IWRITE
36 # endif
37
38 # ifdef __MINGW32__
39 # define _SH_DENYNO 0x40
40 # endif
41
42 #endif // _WIN32
43
44 #ifdef fileno
45 # undef fileno
46 #endif
47
48 namespace {
49 #ifdef _WIN32
50 // Return type of read and write functions.
51 typedef int RWResult;
52
53 // On Windows the count argument to read and write is unsigned, so convert
54 // it from size_t preventing integer overflow.
convert_rwcount(std::size_t count)55 inline unsigned convert_rwcount(std::size_t count) {
56 return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
57 }
58 #else
59 // Return type of read and write functions.
60 typedef ssize_t RWResult;
61
62 inline std::size_t convert_rwcount(std::size_t count) { return count; }
63 #endif
64 }
65
~BufferedFile()66 fmt::BufferedFile::~BufferedFile() FMT_NOEXCEPT {
67 if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
68 fmt::report_system_error(errno, "cannot close file");
69 }
70
BufferedFile(fmt::CStringRef filename,fmt::CStringRef mode)71 fmt::BufferedFile::BufferedFile(
72 fmt::CStringRef filename, fmt::CStringRef mode) {
73 FMT_RETRY_VAL(file_, FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())), 0);
74 if (!file_)
75 FMT_THROW(SystemError(errno, "cannot open file {}", filename));
76 }
77
close()78 void fmt::BufferedFile::close() {
79 if (!file_)
80 return;
81 int result = FMT_SYSTEM(fclose(file_));
82 file_ = FMT_NULL;
83 if (result != 0)
84 FMT_THROW(SystemError(errno, "cannot close file"));
85 }
86
87 // A macro used to prevent expansion of fileno on broken versions of MinGW.
88 #define FMT_ARGS
89
fileno() const90 int fmt::BufferedFile::fileno() const {
91 int fd = FMT_POSIX_CALL(fileno FMT_ARGS(file_));
92 if (fd == -1)
93 FMT_THROW(SystemError(errno, "cannot get file descriptor"));
94 return fd;
95 }
96
File(fmt::CStringRef path,int oflag)97 fmt::File::File(fmt::CStringRef path, int oflag) {
98 int mode = S_IRUSR | S_IWUSR;
99 #if defined(_WIN32) && !defined(__MINGW32__)
100 fd_ = -1;
101 FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
102 #else
103 FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
104 #endif
105 if (fd_ == -1)
106 FMT_THROW(SystemError(errno, "cannot open file {}", path));
107 }
108
~File()109 fmt::File::~File() FMT_NOEXCEPT {
110 // Don't retry close in case of EINTR!
111 // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
112 if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
113 fmt::report_system_error(errno, "cannot close file");
114 }
115
close()116 void fmt::File::close() {
117 if (fd_ == -1)
118 return;
119 // Don't retry close in case of EINTR!
120 // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
121 int result = FMT_POSIX_CALL(close(fd_));
122 fd_ = -1;
123 if (result != 0)
124 FMT_THROW(SystemError(errno, "cannot close file"));
125 }
126
size() const127 fmt::LongLong fmt::File::size() const {
128 #ifdef _WIN32
129 // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
130 // is less than 0x0500 as is the case with some default MinGW builds.
131 // Both functions support large file sizes.
132 DWORD size_upper = 0;
133 HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
134 DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
135 if (size_lower == INVALID_FILE_SIZE) {
136 DWORD error = GetLastError();
137 if (error != NO_ERROR)
138 FMT_THROW(WindowsError(GetLastError(), "cannot get file size"));
139 }
140 fmt::ULongLong long_size = size_upper;
141 return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
142 #else
143 typedef struct stat Stat;
144 Stat file_stat = Stat();
145 if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
146 FMT_THROW(SystemError(errno, "cannot get file attributes"));
147 FMT_STATIC_ASSERT(sizeof(fmt::LongLong) >= sizeof(file_stat.st_size),
148 "return type of File::size is not large enough");
149 return file_stat.st_size;
150 #endif
151 }
152
read(void * buffer,std::size_t count)153 std::size_t fmt::File::read(void *buffer, std::size_t count) {
154 RWResult result = 0;
155 FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, convert_rwcount(count))));
156 if (result < 0)
157 FMT_THROW(SystemError(errno, "cannot read from file"));
158 return internal::to_unsigned(result);
159 }
160
write(const void * buffer,std::size_t count)161 std::size_t fmt::File::write(const void *buffer, std::size_t count) {
162 RWResult result = 0;
163 FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, convert_rwcount(count))));
164 if (result < 0)
165 FMT_THROW(SystemError(errno, "cannot write to file"));
166 return internal::to_unsigned(result);
167 }
168
dup(int fd)169 fmt::File fmt::File::dup(int fd) {
170 // Don't retry as dup doesn't return EINTR.
171 // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
172 int new_fd = FMT_POSIX_CALL(dup(fd));
173 if (new_fd == -1)
174 FMT_THROW(SystemError(errno, "cannot duplicate file descriptor {}", fd));
175 return File(new_fd);
176 }
177
dup2(int fd)178 void fmt::File::dup2(int fd) {
179 int result = 0;
180 FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
181 if (result == -1) {
182 FMT_THROW(SystemError(errno,
183 "cannot duplicate file descriptor {} to {}", fd_, fd));
184 }
185 }
186
dup2(int fd,ErrorCode & ec)187 void fmt::File::dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT {
188 int result = 0;
189 FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
190 if (result == -1)
191 ec = ErrorCode(errno);
192 }
193
pipe(File & read_end,File & write_end)194 void fmt::File::pipe(File &read_end, File &write_end) {
195 // Close the descriptors first to make sure that assignments don't throw
196 // and there are no leaks.
197 read_end.close();
198 write_end.close();
199 int fds[2] = {};
200 #ifdef _WIN32
201 // Make the default pipe capacity same as on Linux 2.6.11+.
202 enum { DEFAULT_CAPACITY = 65536 };
203 int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
204 #else
205 // Don't retry as the pipe function doesn't return EINTR.
206 // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
207 int result = FMT_POSIX_CALL(pipe(fds));
208 #endif
209 if (result != 0)
210 FMT_THROW(SystemError(errno, "cannot create pipe"));
211 // The following assignments don't throw because read_fd and write_fd
212 // are closed.
213 read_end = File(fds[0]);
214 write_end = File(fds[1]);
215 }
216
fdopen(const char * mode)217 fmt::BufferedFile fmt::File::fdopen(const char *mode) {
218 // Don't retry as fdopen doesn't return EINTR.
219 FILE *f = FMT_POSIX_CALL(fdopen(fd_, mode));
220 if (!f)
221 FMT_THROW(SystemError(errno, "cannot associate stream with file descriptor"));
222 BufferedFile file(f);
223 fd_ = -1;
224 return file;
225 }
226
getpagesize()227 long fmt::getpagesize() {
228 #ifdef _WIN32
229 SYSTEM_INFO si;
230 GetSystemInfo(&si);
231 return si.dwPageSize;
232 #else
233 long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
234 if (size < 0)
235 FMT_THROW(SystemError(errno, "cannot get memory page size"));
236 return size;
237 #endif
238 }
239