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 #ifndef FMT_POSIX_H_
11 #define FMT_POSIX_H_
12
13 #if defined(__MINGW32__) || defined(__CYGWIN__)
14 // Workaround MinGW bug https://sourceforge.net/p/mingw/bugs/2024/.
15 # undef __STRICT_ANSI__
16 #endif
17
18 #include <errno.h>
19 #include <fcntl.h> // for O_RDONLY
20 #include <locale.h> // for locale_t
21 #include <stdio.h>
22 #include <stdlib.h> // for strtod_l
23
24 #include <cstddef>
25
26 #if defined __APPLE__ || defined(__FreeBSD__)
27 # include <xlocale.h> // for LC_NUMERIC_MASK on OS X
28 #endif
29
30 #include "format.h"
31
32 #ifndef FMT_POSIX
33 # if defined(_WIN32) && !defined(__MINGW32__)
34 // Fix warnings about deprecated symbols.
35 # define FMT_POSIX(call) _##call
36 # else
37 # define FMT_POSIX(call) call
38 # endif
39 #endif
40
41 // Calls to system functions are wrapped in FMT_SYSTEM for testability.
42 #ifdef FMT_SYSTEM
43 # define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
44 #else
45 # define FMT_SYSTEM(call) call
46 # ifdef _WIN32
47 // Fix warnings about deprecated symbols.
48 # define FMT_POSIX_CALL(call) ::_##call
49 # else
50 # define FMT_POSIX_CALL(call) ::call
51 # endif
52 #endif
53
54 // Retries the expression while it evaluates to error_result and errno
55 // equals to EINTR.
56 #ifndef _WIN32
57 # define FMT_RETRY_VAL(result, expression, error_result) \
58 do { \
59 result = (expression); \
60 } while (result == error_result && errno == EINTR)
61 #else
62 # define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
63 #endif
64
65 #define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
66
67 namespace fmt {
68
69 // An error code.
70 class ErrorCode {
71 private:
72 int value_;
73
74 public:
value_(value)75 explicit ErrorCode(int value = 0) FMT_NOEXCEPT : value_(value) {}
76
get()77 int get() const FMT_NOEXCEPT { return value_; }
78 };
79
80 // A buffered file.
81 class BufferedFile {
82 private:
83 FILE *file_;
84
85 friend class File;
86
BufferedFile(FILE * f)87 explicit BufferedFile(FILE *f) : file_(f) {}
88
89 public:
90 // Constructs a BufferedFile object which doesn't represent any file.
BufferedFile()91 BufferedFile() FMT_NOEXCEPT : file_(FMT_NULL) {}
92
93 // Destroys the object closing the file it represents if any.
94 ~BufferedFile() FMT_NOEXCEPT;
95
96 #if !FMT_USE_RVALUE_REFERENCES
97 // Emulate a move constructor and a move assignment operator if rvalue
98 // references are not supported.
99
100 private:
101 // A proxy object to emulate a move constructor.
102 // It is private to make it impossible call operator Proxy directly.
103 struct Proxy {
104 FILE *file;
105 };
106
107 public:
108 // A "move constructor" for moving from a temporary.
BufferedFile(Proxy p)109 BufferedFile(Proxy p) FMT_NOEXCEPT : file_(p.file) {}
110
111 // A "move constructor" for moving from an lvalue.
BufferedFile(BufferedFile & f)112 BufferedFile(BufferedFile &f) FMT_NOEXCEPT : file_(f.file_) {
113 f.file_ = FMT_NULL;
114 }
115
116 // A "move assignment operator" for moving from a temporary.
117 BufferedFile &operator=(Proxy p) {
118 close();
119 file_ = p.file;
120 return *this;
121 }
122
123 // A "move assignment operator" for moving from an lvalue.
124 BufferedFile &operator=(BufferedFile &other) {
125 close();
126 file_ = other.file_;
127 other.file_ = FMT_NULL;
128 return *this;
129 }
130
131 // Returns a proxy object for moving from a temporary:
132 // BufferedFile file = BufferedFile(...);
Proxy()133 operator Proxy() FMT_NOEXCEPT {
134 Proxy p = {file_};
135 file_ = FMT_NULL;
136 return p;
137 }
138
139 #else
140 private:
141 FMT_DISALLOW_COPY_AND_ASSIGN(BufferedFile);
142
143 public:
BufferedFile(BufferedFile && other)144 BufferedFile(BufferedFile &&other) FMT_NOEXCEPT : file_(other.file_) {
145 other.file_ = FMT_NULL;
146 }
147
148 BufferedFile& operator=(BufferedFile &&other) {
149 close();
150 file_ = other.file_;
151 other.file_ = FMT_NULL;
152 return *this;
153 }
154 #endif
155
156 // Opens a file.
157 BufferedFile(CStringRef filename, CStringRef mode);
158
159 // Closes the file.
160 void close();
161
162 // Returns the pointer to a FILE object representing this file.
get()163 FILE *get() const FMT_NOEXCEPT { return file_; }
164
165 // We place parentheses around fileno to workaround a bug in some versions
166 // of MinGW that define fileno as a macro.
167 int (fileno)() const;
168
print(CStringRef format_str,const ArgList & args)169 void print(CStringRef format_str, const ArgList &args) {
170 fmt::print(file_, format_str, args);
171 }
172 FMT_VARIADIC(void, print, CStringRef)
173 };
174
175 // A file. Closed file is represented by a File object with descriptor -1.
176 // Methods that are not declared with FMT_NOEXCEPT may throw
177 // fmt::SystemError in case of failure. Note that some errors such as
178 // closing the file multiple times will cause a crash on Windows rather
179 // than an exception. You can get standard behavior by overriding the
180 // invalid parameter handler with _set_invalid_parameter_handler.
181 class File {
182 private:
183 int fd_; // File descriptor.
184
185 // Constructs a File object with a given descriptor.
File(int fd)186 explicit File(int fd) : fd_(fd) {}
187
188 public:
189 // Possible values for the oflag argument to the constructor.
190 enum {
191 RDONLY = FMT_POSIX(O_RDONLY), // Open for reading only.
192 WRONLY = FMT_POSIX(O_WRONLY), // Open for writing only.
193 RDWR = FMT_POSIX(O_RDWR) // Open for reading and writing.
194 };
195
196 // Constructs a File object which doesn't represent any file.
File()197 File() FMT_NOEXCEPT : fd_(-1) {}
198
199 // Opens a file and constructs a File object representing this file.
200 File(CStringRef path, int oflag);
201
202 #if !FMT_USE_RVALUE_REFERENCES
203 // Emulate a move constructor and a move assignment operator if rvalue
204 // references are not supported.
205
206 private:
207 // A proxy object to emulate a move constructor.
208 // It is private to make it impossible call operator Proxy directly.
209 struct Proxy {
210 int fd;
211 };
212
213 public:
214 // A "move constructor" for moving from a temporary.
File(Proxy p)215 File(Proxy p) FMT_NOEXCEPT : fd_(p.fd) {}
216
217 // A "move constructor" for moving from an lvalue.
File(File & other)218 File(File &other) FMT_NOEXCEPT : fd_(other.fd_) {
219 other.fd_ = -1;
220 }
221
222 // A "move assignment operator" for moving from a temporary.
223 File &operator=(Proxy p) {
224 close();
225 fd_ = p.fd;
226 return *this;
227 }
228
229 // A "move assignment operator" for moving from an lvalue.
230 File &operator=(File &other) {
231 close();
232 fd_ = other.fd_;
233 other.fd_ = -1;
234 return *this;
235 }
236
237 // Returns a proxy object for moving from a temporary:
238 // File file = File(...);
Proxy()239 operator Proxy() FMT_NOEXCEPT {
240 Proxy p = {fd_};
241 fd_ = -1;
242 return p;
243 }
244
245 #else
246 private:
247 FMT_DISALLOW_COPY_AND_ASSIGN(File);
248
249 public:
File(File && other)250 File(File &&other) FMT_NOEXCEPT : fd_(other.fd_) {
251 other.fd_ = -1;
252 }
253
254 File& operator=(File &&other) {
255 close();
256 fd_ = other.fd_;
257 other.fd_ = -1;
258 return *this;
259 }
260 #endif
261
262 // Destroys the object closing the file it represents if any.
263 ~File() FMT_NOEXCEPT;
264
265 // Returns the file descriptor.
descriptor()266 int descriptor() const FMT_NOEXCEPT { return fd_; }
267
268 // Closes the file.
269 void close();
270
271 // Returns the file size. The size has signed type for consistency with
272 // stat::st_size.
273 LongLong size() const;
274
275 // Attempts to read count bytes from the file into the specified buffer.
276 std::size_t read(void *buffer, std::size_t count);
277
278 // Attempts to write count bytes from the specified buffer to the file.
279 std::size_t write(const void *buffer, std::size_t count);
280
281 // Duplicates a file descriptor with the dup function and returns
282 // the duplicate as a file object.
283 static File dup(int fd);
284
285 // Makes fd be the copy of this file descriptor, closing fd first if
286 // necessary.
287 void dup2(int fd);
288
289 // Makes fd be the copy of this file descriptor, closing fd first if
290 // necessary.
291 void dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT;
292
293 // Creates a pipe setting up read_end and write_end file objects for reading
294 // and writing respectively.
295 static void pipe(File &read_end, File &write_end);
296
297 // Creates a BufferedFile object associated with this file and detaches
298 // this File object from the file.
299 BufferedFile fdopen(const char *mode);
300 };
301
302 // Returns the memory page size.
303 long getpagesize();
304
305 #if (defined(LC_NUMERIC_MASK) || defined(_MSC_VER)) && \
306 !defined(__ANDROID__) && !defined(__CYGWIN__)
307 # define FMT_LOCALE
308 #endif
309
310 #ifdef FMT_LOCALE
311 // A "C" numeric locale.
312 class Locale {
313 private:
314 # ifdef _MSC_VER
315 typedef _locale_t locale_t;
316
317 enum { LC_NUMERIC_MASK = LC_NUMERIC };
318
newlocale(int category_mask,const char * locale,locale_t)319 static locale_t newlocale(int category_mask, const char *locale, locale_t) {
320 return _create_locale(category_mask, locale);
321 }
322
freelocale(locale_t locale)323 static void freelocale(locale_t locale) {
324 _free_locale(locale);
325 }
326
strtod_l(const char * nptr,char ** endptr,_locale_t locale)327 static double strtod_l(const char *nptr, char **endptr, _locale_t locale) {
328 return _strtod_l(nptr, endptr, locale);
329 }
330 # endif
331
332 locale_t locale_;
333
334 FMT_DISALLOW_COPY_AND_ASSIGN(Locale);
335
336 public:
337 typedef locale_t Type;
338
Locale()339 Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", FMT_NULL)) {
340 if (!locale_)
341 FMT_THROW(fmt::SystemError(errno, "cannot create locale"));
342 }
~Locale()343 ~Locale() { freelocale(locale_); }
344
get()345 Type get() const { return locale_; }
346
347 // Converts string to floating-point number and advances str past the end
348 // of the parsed input.
strtod(const char * & str)349 double strtod(const char *&str) const {
350 char *end = FMT_NULL;
351 double result = strtod_l(str, &end, locale_);
352 str = end;
353 return result;
354 }
355 };
356 #endif // FMT_LOCALE
357 } // namespace fmt
358
359 #if !FMT_USE_RVALUE_REFERENCES
360 namespace std {
361 // For compatibility with C++98.
move(fmt::BufferedFile & f)362 inline fmt::BufferedFile &move(fmt::BufferedFile &f) { return f; }
move(fmt::File & f)363 inline fmt::File &move(fmt::File &f) { return f; }
364 }
365 #endif
366
367 #endif // FMT_POSIX_H_
368