1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dbus-errors.c Error reporting
4 * Copyright (C) 2002, 2004 Red Hat Inc.
5 * Copyright (C) 2003 CodeFactory AB
7 * Licensed under the Academic Free License version 2.1
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include "dbus-errors.h"
25 #include "dbus-internals.h"
26 #include "dbus-string.h"
27 #include "dbus-protocol.h"
32 * @defgroup DBusErrorInternals Error reporting internals
33 * @ingroup DBusInternals
34 * @brief Error reporting internals
39 * Internals of DBusError
43 char *name; /**< error name */
44 char *message; /**< error message */
46 unsigned int const_message : 1; /**< Message is not owned by DBusError */
48 unsigned int dummy2 : 1; /**< placeholder */
49 unsigned int dummy3 : 1; /**< placeholder */
50 unsigned int dummy4 : 1; /**< placeholder */
51 unsigned int dummy5 : 1; /**< placeholder */
53 void *padding1; /**< placeholder */
58 * Returns a longer message describing an error name.
59 * If the error name is unknown, returns the name
62 * @param error the error to describe
63 * @returns a constant string describing the error.
66 message_from_error (const char *error)
68 if (strcmp (error, DBUS_ERROR_FAILED) == 0)
69 return "Unknown error";
70 else if (strcmp (error, DBUS_ERROR_NO_MEMORY) == 0)
71 return "Not enough memory available";
72 else if (strcmp (error, DBUS_ERROR_IO_ERROR) == 0)
73 return "Error reading or writing data";
74 else if (strcmp (error, DBUS_ERROR_BAD_ADDRESS) == 0)
75 return "Could not parse address";
76 else if (strcmp (error, DBUS_ERROR_NOT_SUPPORTED) == 0)
77 return "Feature not supported";
78 else if (strcmp (error, DBUS_ERROR_LIMITS_EXCEEDED) == 0)
79 return "Resource limits exceeded";
80 else if (strcmp (error, DBUS_ERROR_ACCESS_DENIED) == 0)
81 return "Permission denied";
82 else if (strcmp (error, DBUS_ERROR_AUTH_FAILED) == 0)
83 return "Could not authenticate to server";
84 else if (strcmp (error, DBUS_ERROR_NO_SERVER) == 0)
85 return "No server available at address";
86 else if (strcmp (error, DBUS_ERROR_TIMEOUT) == 0)
87 return "Connection timed out";
88 else if (strcmp (error, DBUS_ERROR_NO_NETWORK) == 0)
89 return "Network unavailable";
90 else if (strcmp (error, DBUS_ERROR_ADDRESS_IN_USE) == 0)
91 return "Address already in use";
92 else if (strcmp (error, DBUS_ERROR_DISCONNECTED) == 0)
93 return "Disconnected.";
94 else if (strcmp (error, DBUS_ERROR_INVALID_ARGS) == 0)
95 return "Invalid arguments.";
96 else if (strcmp (error, DBUS_ERROR_NO_REPLY) == 0)
97 return "Did not get a reply message.";
98 else if (strcmp (error, DBUS_ERROR_FILE_NOT_FOUND) == 0)
99 return "File doesn't exist.";
104 /** @} */ /* End of internals */
107 * @defgroup DBusErrors Error reporting
109 * @brief Error reporting
111 * Types and functions related to reporting errors.
114 * In essence D-Bus error reporting works as follows:
118 * dbus_error_init (&error);
119 * dbus_some_function (arg1, arg2, &error);
120 * if (dbus_error_is_set (&error))
122 * fprintf (stderr, "an error occurred: %s\n", error.message);
123 * dbus_error_free (&error);
127 * By convention, all functions allow #NULL instead of a DBusError*,
128 * so callers who don't care about the error can ignore it.
130 * There are some rules. An error passed to a D-Bus function must
131 * always be unset; you can't pass in an error that's already set. If
132 * a function has a return code indicating whether an error occurred,
133 * and also a #DBusError parameter, then the error will always be set
134 * if and only if the return code indicates an error occurred. i.e.
135 * the return code and the error are never going to disagree.
137 * An error only needs to be freed if it's been set, not if
138 * it's merely been initialized.
140 * You can check the specific error that occurred using
141 * dbus_error_has_name().
143 * Errors will not be set for programming errors, such as passing
144 * invalid arguments to the libdbus API. Instead, libdbus will print
145 * warnings, exit on a failed assertion, or even crash in those cases
146 * (in other words, incorrect use of the API results in undefined
147 * behavior, possibly accompanied by helpful debugging output if
154 * Initializes a DBusError structure. Does not allocate any memory;
155 * the error only needs to be freed if it is set at some point.
157 * @param error the DBusError.
160 dbus_error_init (DBusError *error)
164 _dbus_return_if_fail (error != NULL);
166 _dbus_assert (sizeof (DBusError) == sizeof (DBusRealError));
168 real = (DBusRealError *)error;
171 real->message = NULL;
173 real->const_message = TRUE;
177 * Frees an error that's been set (or just initialized),
178 * then reinitializes the error as in dbus_error_init().
180 * @param error memory where the error is stored.
183 dbus_error_free (DBusError *error)
187 _dbus_return_if_fail (error != NULL);
189 real = (DBusRealError *)error;
191 if (!real->const_message)
193 dbus_free (real->name);
194 dbus_free (real->message);
197 dbus_error_init (error);
201 * Assigns an error name and message to a DBusError. Does nothing if
202 * error is #NULL. The message may be #NULL, which means a default
203 * message will be deduced from the name. The default message will be
204 * totally useless, though, so using a #NULL message is not recommended.
206 * Because this function does not copy the error name or message, you
207 * must ensure the name and message are global data that won't be
208 * freed. You probably want dbus_set_error() instead, in most cases.
210 * @param error the error.or #NULL
211 * @param name the error name (not copied!!!)
212 * @param message the error message (not copied!!!)
215 dbus_set_error_const (DBusError *error,
221 _dbus_return_if_error_is_set (error);
222 _dbus_return_if_fail (name != NULL);
227 _dbus_assert (error->name == NULL);
228 _dbus_assert (error->message == NULL);
231 message = message_from_error (name);
233 real = (DBusRealError *)error;
235 real->name = (char*) name;
236 real->message = (char *)message;
237 real->const_message = TRUE;
241 * Moves an error src into dest, freeing src and
242 * overwriting dest. Both src and dest must be initialized.
243 * src is reinitialized to an empty error. dest may not
244 * contain an existing error. If the destination is
245 * #NULL, just frees and reinits the source error.
247 * @param src the source error
248 * @param dest the destination error or #NULL
251 dbus_move_error (DBusError *src,
254 _dbus_return_if_error_is_set (dest);
258 dbus_error_free (dest);
260 dbus_error_init (src);
263 dbus_error_free (src);
267 * Checks whether the error is set and has the given
269 * @param error the error
270 * @param name the name
271 * @returns #TRUE if the given named error occurred
274 dbus_error_has_name (const DBusError *error,
277 _dbus_return_val_if_fail (error != NULL, FALSE);
278 _dbus_return_val_if_fail (name != NULL, FALSE);
280 _dbus_assert ((error->name != NULL && error->message != NULL) ||
281 (error->name == NULL && error->message == NULL));
283 if (error->name != NULL)
285 DBusString str1, str2;
286 _dbus_string_init_const (&str1, error->name);
287 _dbus_string_init_const (&str2, name);
288 return _dbus_string_equal (&str1, &str2);
295 * Checks whether an error occurred (the error is set).
297 * @param error the error object
298 * @returns #TRUE if an error occurred
301 dbus_error_is_set (const DBusError *error)
303 _dbus_return_val_if_fail (error != NULL, FALSE);
304 _dbus_assert ((error->name != NULL && error->message != NULL) ||
305 (error->name == NULL && error->message == NULL));
306 return error->name != NULL;
310 * Assigns an error name and message to a DBusError.
311 * Does nothing if error is #NULL.
313 * The format may be #NULL, which means a (pretty much useless)
314 * default message will be deduced from the name. This is not a good
315 * idea, just go ahead and provide a useful error message. It won't
318 * If no memory can be allocated for the error message,
319 * an out-of-memory error message will be set instead.
321 * @param error the error.or #NULL
322 * @param name the error name
323 * @param format printf-style format string.
326 dbus_set_error (DBusError *error,
338 /* it's a bug to pile up errors */
339 _dbus_return_if_error_is_set (error);
340 _dbus_return_if_fail (name != NULL);
342 _dbus_assert (error->name == NULL);
343 _dbus_assert (error->message == NULL);
345 if (!_dbus_string_init (&str))
350 if (!_dbus_string_append (&str,
351 message_from_error (name)))
353 _dbus_string_free (&str);
359 va_start (args, format);
360 if (!_dbus_string_append_printf_valist (&str, format, args))
362 _dbus_string_free (&str);
368 real = (DBusRealError *)error;
370 if (!_dbus_string_steal_data (&str, &real->message))
372 _dbus_string_free (&str);
375 _dbus_string_free (&str);
377 real->name = _dbus_strdup (name);
378 if (real->name == NULL)
380 dbus_free (real->message);
381 real->message = NULL;
384 real->const_message = FALSE;
389 _DBUS_SET_OOM (error);
392 /** @} */ /* End public API */