1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
20 * file for a list of people on the GLib Team. See the ChangeLog
21 * files for a list of changes. These files are distributed with
22 * GLib at ftp://ftp.gtk.org/pub/gtk/.
25 #ifndef __G_MESSAGES_H__
26 #define __G_MESSAGES_H__
28 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
29 #error "Only <glib.h> can be included directly."
33 #include <glib/gatomic.h>
34 #include <glib/gtypes.h>
35 #include <glib/gmacros.h>
36 #include <glib/gvariant.h>
40 /* calculate a string size, guaranteed to fit format + args.
43 gsize g_printf_string_upper_bound (const gchar* format,
44 va_list args) G_GNUC_PRINTF(1, 0);
46 /* Log level shift offset for user defined
47 * log levels (0-7 are used by GLib).
49 #define G_LOG_LEVEL_USER_SHIFT (8)
51 /* Glib log levels and flags.
56 G_LOG_FLAG_RECURSION = 1 << 0,
57 G_LOG_FLAG_FATAL = 1 << 1,
60 G_LOG_LEVEL_ERROR = 1 << 2, /* always fatal */
61 G_LOG_LEVEL_CRITICAL = 1 << 3,
62 G_LOG_LEVEL_WARNING = 1 << 4,
63 G_LOG_LEVEL_MESSAGE = 1 << 5,
64 G_LOG_LEVEL_INFO = 1 << 6,
65 G_LOG_LEVEL_DEBUG = 1 << 7,
67 G_LOG_LEVEL_MASK = ~(G_LOG_FLAG_RECURSION | G_LOG_FLAG_FATAL)
70 /* GLib log levels that are considered fatal by default */
71 #define G_LOG_FATAL_MASK (G_LOG_FLAG_RECURSION | G_LOG_LEVEL_ERROR)
73 typedef void (*GLogFunc) (const gchar *log_domain,
74 GLogLevelFlags log_level,
81 guint g_log_set_handler (const gchar *log_domain,
82 GLogLevelFlags log_levels,
85 GLIB_AVAILABLE_IN_2_46
86 guint g_log_set_handler_full (const gchar *log_domain,
87 GLogLevelFlags log_levels,
90 GDestroyNotify destroy);
92 void g_log_remove_handler (const gchar *log_domain,
95 void g_log_default_handler (const gchar *log_domain,
96 GLogLevelFlags log_level,
98 gpointer unused_data);
100 GLogFunc g_log_set_default_handler (GLogFunc log_func,
102 GLIB_AVAILABLE_IN_ALL
103 void g_log (const gchar *log_domain,
104 GLogLevelFlags log_level,
106 ...) G_GNUC_PRINTF (3, 4);
107 GLIB_AVAILABLE_IN_ALL
108 void g_logv (const gchar *log_domain,
109 GLogLevelFlags log_level,
111 va_list args) G_GNUC_PRINTF(3, 0);
112 GLIB_AVAILABLE_IN_ALL
113 GLogLevelFlags g_log_set_fatal_mask (const gchar *log_domain,
114 GLogLevelFlags fatal_mask);
115 GLIB_AVAILABLE_IN_ALL
116 GLogLevelFlags g_log_set_always_fatal (GLogLevelFlags fatal_mask);
118 /* Structured logging mechanism. */
122 * @G_LOG_WRITER_HANDLED: Log writer has handled the log entry.
123 * @G_LOG_WRITER_UNHANDLED: Log writer could not handle the log entry.
125 * Return values from #GLogWriterFuncs to indicate whether the given log entry
126 * was successfully handled by the writer, or whether there was an error in
127 * handling it (and hence a fallback writer should be used).
129 * If a #GLogWriterFunc ignores a log entry, it should return
130 * %G_LOG_WRITER_HANDLED.
136 G_LOG_WRITER_HANDLED = 1,
137 G_LOG_WRITER_UNHANDLED = 0,
142 * @key: field name (UTF-8 string)
143 * @value: field value (arbitrary bytes)
144 * @length: length of @value, in bytes, or -1 if it is nul-terminated
146 * Structure representing a single field in a structured log entry. See
147 * g_log_structured() for details.
149 * Log fields may contain arbitrary values, including binary with embedded nul
150 * bytes. If the field contains a string, the string must be UTF-8 encoded and
151 * have a trailing nul byte. Otherwise, @length must be set to a non-negative
156 typedef struct _GLogField GLogField;
166 * @log_level: log level of the message
167 * @fields: (array length=n_fields): fields forming the message
168 * @n_fields: number of @fields
169 * @user_data: user data passed to g_log_set_writer_func()
171 * Writer function for log entries. A log entry is a collection of one or more
172 * #GLogFields, using the standard [field names from journal
173 * specification](https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html).
174 * See g_log_structured() for more information.
176 * Writer functions must ignore fields which they do not recognise, unless they
177 * can write arbitrary binary output, as field values may be arbitrary binary.
179 * @log_level is guaranteed to be included in @fields as the `PRIORITY` field,
180 * but is provided separately for convenience of deciding whether or where to
181 * output the log entry.
183 * Writer functions should return %G_LOG_WRITER_HANDLED if they handled the log
184 * message successfully or if they deliberately ignored it. If there was an
185 * error handling the message (for example, if the writer function is meant to
186 * send messages to a remote logging server and there is a network error), it
187 * should return %G_LOG_WRITER_UNHANDLED. This allows writer functions to be
188 * chained and fall back to simpler handlers in case of failure.
190 * Returns: %G_LOG_WRITER_HANDLED if the log entry was handled successfully;
191 * %G_LOG_WRITER_UNHANDLED otherwise
194 typedef GLogWriterOutput (*GLogWriterFunc) (GLogLevelFlags log_level,
195 const GLogField *fields,
199 GLIB_AVAILABLE_IN_2_50
200 void g_log_structured (const gchar *log_domain,
201 GLogLevelFlags log_level,
203 GLIB_AVAILABLE_IN_2_50
204 void g_log_structured_array (GLogLevelFlags log_level,
205 const GLogField *fields,
208 GLIB_AVAILABLE_IN_2_50
209 void g_log_variant (const gchar *log_domain,
210 GLogLevelFlags log_level,
213 GLIB_AVAILABLE_IN_2_50
214 void g_log_set_writer_func (GLogWriterFunc func,
216 GDestroyNotify user_data_free);
218 GLIB_AVAILABLE_IN_2_50
219 gboolean g_log_writer_supports_color (gint output_fd);
220 GLIB_AVAILABLE_IN_2_50
221 gboolean g_log_writer_is_journald (gint output_fd);
223 GLIB_AVAILABLE_IN_2_50
224 gchar *g_log_writer_format_fields (GLogLevelFlags log_level,
225 const GLogField *fields,
229 GLIB_AVAILABLE_IN_2_50
230 GLogWriterOutput g_log_writer_journald (GLogLevelFlags log_level,
231 const GLogField *fields,
234 GLIB_AVAILABLE_IN_2_50
235 GLogWriterOutput g_log_writer_standard_streams (GLogLevelFlags log_level,
236 const GLogField *fields,
239 GLIB_AVAILABLE_IN_2_50
240 GLogWriterOutput g_log_writer_default (GLogLevelFlags log_level,
241 const GLogField *fields,
245 GLIB_AVAILABLE_IN_2_68
246 void g_log_writer_default_set_use_stderr (gboolean use_stderr);
247 GLIB_AVAILABLE_IN_2_68
248 gboolean g_log_writer_default_would_drop (GLogLevelFlags log_level,
249 const char *log_domain);
254 * A convenience form of g_log_structured(), recommended to be added to
255 * functions when debugging. It prints the current monotonic time and the code
256 * location using %G_STRLOC.
260 #define G_DEBUG_HERE() \
261 g_log_structured (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
262 "CODE_FILE", __FILE__, \
263 "CODE_LINE", G_STRINGIFY (__LINE__), \
264 "CODE_FUNC", G_STRFUNC, \
265 "MESSAGE", "%" G_GINT64_FORMAT ": %s", \
266 g_get_monotonic_time (), G_STRLOC)
269 void _g_log_fallback_handler (const gchar *log_domain,
270 GLogLevelFlags log_level,
271 const gchar *message,
272 gpointer unused_data);
274 /* Internal functions, used to implement the following macros */
275 GLIB_AVAILABLE_IN_ALL
276 void g_return_if_fail_warning (const char *log_domain,
277 const char *pretty_function,
278 const char *expression) G_ANALYZER_NORETURN;
279 GLIB_AVAILABLE_IN_ALL
280 void g_warn_message (const char *domain,
284 const char *warnexpr) G_ANALYZER_NORETURN;
286 void g_assert_warning (const char *log_domain,
289 const char *pretty_function,
290 const char *expression) G_GNUC_NORETURN;
292 GLIB_AVAILABLE_IN_2_56
293 void g_log_structured_standard (const gchar *log_domain,
294 GLogLevelFlags log_level,
298 const gchar *message_format,
299 ...) G_GNUC_PRINTF (6, 7);
302 #define G_LOG_DOMAIN ((gchar*) 0)
303 #endif /* G_LOG_DOMAIN */
305 #if defined(G_HAVE_ISO_VARARGS) && !G_ANALYZER_ANALYZING
306 #if defined(G_LOG_USE_STRUCTURED) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_56
307 #define g_error(...) G_STMT_START { \
308 g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_ERROR, \
309 __FILE__, G_STRINGIFY (__LINE__), \
310 G_STRFUNC, __VA_ARGS__); \
313 #define g_message(...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, \
314 __FILE__, G_STRINGIFY (__LINE__), \
315 G_STRFUNC, __VA_ARGS__)
316 #define g_critical(...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL, \
317 __FILE__, G_STRINGIFY (__LINE__), \
318 G_STRFUNC, __VA_ARGS__)
319 #define g_warning(...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING, \
320 __FILE__, G_STRINGIFY (__LINE__), \
321 G_STRFUNC, __VA_ARGS__)
322 #define g_info(...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, \
323 __FILE__, G_STRINGIFY (__LINE__), \
324 G_STRFUNC, __VA_ARGS__)
325 #define g_debug(...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
326 __FILE__, G_STRINGIFY (__LINE__), \
327 G_STRFUNC, __VA_ARGS__)
329 /* for(;;) ; so that GCC knows that control doesn't go past g_error().
330 * Put space before ending semicolon to avoid C++ build warnings.
332 #define g_error(...) G_STMT_START { \
333 g_log (G_LOG_DOMAIN, \
338 #define g_message(...) g_log (G_LOG_DOMAIN, \
339 G_LOG_LEVEL_MESSAGE, \
341 #define g_critical(...) g_log (G_LOG_DOMAIN, \
342 G_LOG_LEVEL_CRITICAL, \
344 #define g_warning(...) g_log (G_LOG_DOMAIN, \
345 G_LOG_LEVEL_WARNING, \
347 #define g_info(...) g_log (G_LOG_DOMAIN, \
350 #define g_debug(...) g_log (G_LOG_DOMAIN, \
354 #elif defined(G_HAVE_GNUC_VARARGS) && !G_ANALYZER_ANALYZING
355 #if defined(G_LOG_USE_STRUCTURED) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_56
356 #define g_error(format...) G_STMT_START { \
357 g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_ERROR, \
358 __FILE__, G_STRINGIFY (__LINE__), \
359 G_STRFUNC, format); \
362 #define g_message(format...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, \
363 __FILE__, G_STRINGIFY (__LINE__), \
365 #define g_critical(format...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL, \
366 __FILE__, G_STRINGIFY (__LINE__), \
368 #define g_warning(format...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING, \
369 __FILE__, G_STRINGIFY (__LINE__), \
371 #define g_info(format...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, \
372 __FILE__, G_STRINGIFY (__LINE__), \
374 #define g_debug(format...) g_log_structured_standard (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
375 __FILE__, G_STRINGIFY (__LINE__), \
378 #define g_error(format...) G_STMT_START { \
379 g_log (G_LOG_DOMAIN, \
385 #define g_message(format...) g_log (G_LOG_DOMAIN, \
386 G_LOG_LEVEL_MESSAGE, \
388 #define g_critical(format...) g_log (G_LOG_DOMAIN, \
389 G_LOG_LEVEL_CRITICAL, \
391 #define g_warning(format...) g_log (G_LOG_DOMAIN, \
392 G_LOG_LEVEL_WARNING, \
394 #define g_info(format...) g_log (G_LOG_DOMAIN, \
397 #define g_debug(format...) g_log (G_LOG_DOMAIN, \
401 #else /* no varargs macros */
402 static void g_error (const gchar *format, ...) G_GNUC_NORETURN G_ANALYZER_NORETURN;
403 static void g_critical (const gchar *format, ...) G_ANALYZER_NORETURN;
406 g_error (const gchar *format,
410 va_start (args, format);
411 g_logv (G_LOG_DOMAIN, G_LOG_LEVEL_ERROR, format, args);
417 g_message (const gchar *format,
421 va_start (args, format);
422 g_logv (G_LOG_DOMAIN, G_LOG_LEVEL_MESSAGE, format, args);
426 g_critical (const gchar *format,
430 va_start (args, format);
431 g_logv (G_LOG_DOMAIN, G_LOG_LEVEL_CRITICAL, format, args);
435 g_warning (const gchar *format,
439 va_start (args, format);
440 g_logv (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING, format, args);
444 g_info (const gchar *format,
448 va_start (args, format);
449 g_logv (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, format, args);
453 g_debug (const gchar *format,
457 va_start (args, format);
458 g_logv (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, format, args);
461 #endif /* !__GNUC__ */
465 * @...: format string, followed by parameters to insert
466 * into the format string (as with printf())
468 * Logs a warning only once.
470 * g_warning_once() calls g_warning() with the passed message the first time
471 * the statement is executed; subsequent times it is a no-op.
473 * Note! On platforms where the compiler doesn't support variadic macros, the
474 * warning is printed each time instead of only once.
478 #if defined(G_HAVE_ISO_VARARGS) && !G_ANALYZER_ANALYZING
479 #define g_warning_once(...) \
481 static volatile int G_PASTE (_GWarningOnceBoolean, __LINE__) = 0; \
482 if (g_atomic_int_compare_and_exchange (&G_PASTE (_GWarningOnceBoolean, __LINE__), \
484 g_warning (__VA_ARGS__); \
486 GLIB_AVAILABLE_MACRO_IN_2_64
487 #elif defined(G_HAVE_GNUC_VARARGS) && !G_ANALYZER_ANALYZING
488 #define g_warning_once(format...) \
490 static volatile int G_PASTE (_GWarningOnceBoolean, __LINE__) = 0; \
491 if (g_atomic_int_compare_and_exchange (&G_PASTE (_GWarningOnceBoolean, __LINE__), \
493 g_warning (format); \
495 GLIB_AVAILABLE_MACRO_IN_2_64
497 #define g_warning_once g_warning
502 * @string: the message to output
504 * Specifies the type of the print handler functions.
505 * These are called with the complete formatted string to output.
507 typedef void (*GPrintFunc) (const gchar *string);
508 GLIB_AVAILABLE_IN_ALL
509 void g_print (const gchar *format,
510 ...) G_GNUC_PRINTF (1, 2);
511 GLIB_AVAILABLE_IN_ALL
512 GPrintFunc g_set_print_handler (GPrintFunc func);
513 GLIB_AVAILABLE_IN_ALL
514 void g_printerr (const gchar *format,
515 ...) G_GNUC_PRINTF (1, 2);
516 GLIB_AVAILABLE_IN_ALL
517 GPrintFunc g_set_printerr_handler (GPrintFunc func);
526 #define g_warn_if_reached() \
528 g_warn_message (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, NULL); \
533 * @expr: the expression to check
535 * Logs a warning if the expression is not true.
539 #define g_warn_if_fail(expr) \
541 if G_LIKELY (expr) ; \
542 else g_warn_message (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, #expr); \
545 #ifdef G_DISABLE_CHECKS
549 * @expr: the expression to check
551 * Verifies that the expression @expr, usually representing a precondition,
552 * evaluates to %TRUE. If the function returns a value, use
553 * g_return_val_if_fail() instead.
555 * If @expr evaluates to %FALSE, the current function should be considered to
556 * have undefined behaviour (a programmer error). The only correct solution
557 * to such an error is to change the module that is calling the current
558 * function, so that it avoids this incorrect call.
560 * To make this undefined behaviour visible, if @expr evaluates to %FALSE,
561 * the result is usually that a critical message is logged and the current
564 * If `G_DISABLE_CHECKS` is defined then the check is not performed. You
565 * should therefore not depend on any side effects of @expr.
567 * To debug failure of a g_return_if_fail() check, run the code under a debugger
568 * with `G_DEBUG=fatal-criticals` or `G_DEBUG=fatal-warnings` defined in the
569 * environment (see [Running GLib Applications](glib-running.html)):
572 * G_DEBUG=fatal-warnings gdb ./my-program
575 * Any unrelated failures can be skipped over in
576 * [gdb](https://www.gnu.org/software/gdb/) using the `continue` command.
578 #define g_return_if_fail(expr) G_STMT_START{ (void)0; }G_STMT_END
581 * g_return_val_if_fail:
582 * @expr: the expression to check
583 * @val: the value to return from the current function
584 * if the expression is not true
586 * Verifies that the expression @expr, usually representing a precondition,
587 * evaluates to %TRUE. If the function does not return a value, use
588 * g_return_if_fail() instead.
590 * If @expr evaluates to %FALSE, the current function should be considered to
591 * have undefined behaviour (a programmer error). The only correct solution
592 * to such an error is to change the module that is calling the current
593 * function, so that it avoids this incorrect call.
595 * To make this undefined behaviour visible, if @expr evaluates to %FALSE,
596 * the result is usually that a critical message is logged and @val is
597 * returned from the current function.
599 * If `G_DISABLE_CHECKS` is defined then the check is not performed. You
600 * should therefore not depend on any side effects of @expr.
602 * See g_return_if_fail() for guidance on how to debug failure of this check.
604 #define g_return_val_if_fail(expr,val) G_STMT_START{ (void)0; }G_STMT_END
607 * g_return_if_reached:
609 * Logs a critical message and returns from the current function.
610 * This can only be used in functions which do not return a value.
612 * See g_return_if_fail() for guidance on how to debug failure of this check.
614 #define g_return_if_reached() G_STMT_START{ return; }G_STMT_END
617 * g_return_val_if_reached:
618 * @val: the value to return from the current function
620 * Logs a critical message and returns @val.
622 * See g_return_if_fail() for guidance on how to debug failure of this check.
624 #define g_return_val_if_reached(val) G_STMT_START{ return (val); }G_STMT_END
626 #else /* !G_DISABLE_CHECKS */
628 #define g_return_if_fail(expr) \
630 if (G_LIKELY (expr)) \
634 g_return_if_fail_warning (G_LOG_DOMAIN, \
641 #define g_return_val_if_fail(expr, val) \
643 if (G_LIKELY (expr)) \
647 g_return_if_fail_warning (G_LOG_DOMAIN, \
654 #define g_return_if_reached() \
656 g_log (G_LOG_DOMAIN, \
657 G_LOG_LEVEL_CRITICAL, \
658 "file %s: line %d (%s): should not be reached", \
665 #define g_return_val_if_reached(val) \
667 g_log (G_LOG_DOMAIN, \
668 G_LOG_LEVEL_CRITICAL, \
669 "file %s: line %d (%s): should not be reached", \
676 #endif /* !G_DISABLE_CHECKS */
680 #endif /* __G_MESSAGES_H__ */