summaryrefslogtreecommitdiff
path: root/glib/gerror.h
blob: 1aebfbeb9250215fc06f005edc6906d5fafe861d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
/* gerror.h - Error reporting system
 *
 *  Copyright 2000 Red Hat, Inc.
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __G_ERROR_H__
#define __G_ERROR_H__

#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
#error "Only <glib.h> can be included directly."
#endif

#include <stdarg.h>

#include <glib/gquark.h>

G_BEGIN_DECLS

/**
 * GError:
 * @domain: error domain, e.g. %G_FILE_ERROR
 * @code: error code, e.g. %G_FILE_ERROR_NOENT
 * @message: human-readable informative error message
 *
 * The `GError` structure contains information about
 * an error that has occurred.
 */
typedef struct _GError GError;

struct _GError
{
  GQuark       domain;
  gint         code;
  gchar       *message;
};

/**
 * G_DEFINE_EXTENDED_ERROR:
 * @ErrorType: name to return a #GQuark for
 * @error_type: prefix for the function name
 *
 * A convenience macro which defines two functions. First, returning
 * the #GQuark for the extended error type @ErrorType; it is called
 * `error_type_quark()`. Second, returning the private data from a
 * passed #GError; it is called `error_type_get_private()`.
 *
 * For this macro to work, a type named `ErrorTypePrivate` should be
 * defined, `error_type_private_init()`, `error_type_private_copy()`
 * and `error_type_private_clear()` functions need to be either
 * declared or defined. The functions should be similar to
 * #GErrorInitFunc, #GErrorCopyFunc and #GErrorClearFunc,
 * respectively, but they should receive the private data type instead
 * of #GError.
 *
 * See [Extended #GError Domains][gerror-extended-domains] for an example.
 *
 * Since: 2.68
 */
#define G_DEFINE_EXTENDED_ERROR(ErrorType, error_type)                  \
static inline ErrorType ## Private *                                    \
error_type ## _get_private (const GError *error)                        \
{                                                                       \
  /* Copied from gtype.c (STRUCT_ALIGNMENT and ALIGN_STRUCT macros). */ \
  const gsize sa = 2 * sizeof (gsize);                                  \
  const gsize as = (sizeof (ErrorType ## Private) + (sa - 1)) & -sa;    \
  g_return_val_if_fail (error != NULL, NULL);                           \
  g_return_val_if_fail (error->domain == error_type ## _quark (), NULL); \
  return (ErrorType ## Private *) (((guint8 *)error) - as); \
}                                                                       \
                                                                        \
static void                                                             \
g_error_with_ ## error_type ## _private_init (GError *error)            \
{                                                                       \
  ErrorType ## Private *priv = error_type ## _get_private (error);      \
  error_type ## _private_init (priv);                                   \
}                                                                       \
                                                                        \
static void                                                             \
g_error_with_ ## error_type ## _private_copy (const GError *src_error,  \
                                              GError       *dest_error) \
{                                                                       \
  const ErrorType ## Private *src_priv = error_type ## _get_private (src_error);  \
  ErrorType ## Private *dest_priv = error_type ## _get_private (dest_error); \
  error_type ## _private_copy (src_priv, dest_priv);                    \
}                                                                       \
                                                                        \
static void                                                             \
g_error_with_ ## error_type ## _private_clear (GError *error)           \
{                                                                       \
  ErrorType ## Private *priv = error_type ## _get_private (error);      \
  error_type ## _private_clear (priv);                                  \
}                                                                       \
                                                                        \
GQuark                                                                  \
error_type ## _quark (void)                                             \
{                                                                       \
  static GQuark q;                                                      \
  static gsize initialized = 0;                                         \
                                                                        \
  if (g_once_init_enter (&initialized))                                 \
    {                                                                   \
      q = g_error_domain_register_static (#ErrorType,                   \
                                          sizeof (ErrorType ## Private), \
                                          g_error_with_ ## error_type ## _private_init, \
                                          g_error_with_ ## error_type ## _private_copy, \
                                          g_error_with_ ## error_type ## _private_clear); \
      g_once_init_leave (&initialized, 1);                              \
    }                                                                   \
                                                                        \
  return q;                                                             \
}

/**
 * GErrorInitFunc:
 * @error: extended error
 *
 * Specifies the type of function which is called just after an
 * extended error instance is created and its fields filled. It should
 * only initialize the fields in the private data, which can be
 * received with the generated `*_get_private()` function.
 *
 * Normally, it is better to use G_DEFINE_EXTENDED_ERROR(), as it
 * already takes care of getting the private data from @error.
 *
 * Since: 2.68
 */
typedef void (*GErrorInitFunc) (GError *error);

/**
 * GErrorCopyFunc:
 * @src_error: source extended error
 * @dest_error: destination extended error
 *
 * Specifies the type of function which is called when an extended
 * error instance is copied. It is passed the pointer to the
 * destination error and source error, and should copy only the fields
 * of the private data from @src_error to @dest_error.
 *
 * Normally, it is better to use G_DEFINE_EXTENDED_ERROR(), as it
 * already takes care of getting the private data from @src_error and
 * @dest_error.
 *
 * Since: 2.68
 */
typedef void (*GErrorCopyFunc) (const GError *src_error, GError *dest_error);

/**
 * GErrorClearFunc:
 * @error: extended error to clear
 *
 * Specifies the type of function which is called when an extended
 * error instance is freed. It is passed the error pointer about to be
 * freed, and should free the error's private data fields.
 *
 * Normally, it is better to use G_DEFINE_EXTENDED_ERROR(), as it
 * already takes care of getting the private data from @error.
 *
 * Since: 2.68
 */
typedef void (*GErrorClearFunc) (GError *error);

GLIB_AVAILABLE_IN_2_68
GQuark   g_error_domain_register_static (const char        *error_type_name,
                                         gsize              error_type_private_size,
                                         GErrorInitFunc     error_type_init,
                                         GErrorCopyFunc     error_type_copy,
                                         GErrorClearFunc    error_type_clear);

GLIB_AVAILABLE_IN_2_68
GQuark   g_error_domain_register (const char        *error_type_name,
                                  gsize              error_type_private_size,
                                  GErrorInitFunc     error_type_init,
                                  GErrorCopyFunc     error_type_copy,
                                  GErrorClearFunc    error_type_clear);

GLIB_AVAILABLE_IN_ALL
GError*  g_error_new           (GQuark         domain,
                                gint           code,
                                const gchar   *format,
                                ...) G_GNUC_PRINTF (3, 4);

GLIB_AVAILABLE_IN_ALL
GError*  g_error_new_literal   (GQuark         domain,
                                gint           code,
                                const gchar   *message);
GLIB_AVAILABLE_IN_ALL
GError*  g_error_new_valist    (GQuark         domain,
                                gint           code,
                                const gchar   *format,
                                va_list        args) G_GNUC_PRINTF(3, 0);

GLIB_AVAILABLE_IN_ALL
void     g_error_free          (GError        *error);
GLIB_AVAILABLE_IN_ALL
GError*  g_error_copy          (const GError  *error);

GLIB_AVAILABLE_IN_ALL
gboolean g_error_matches       (const GError  *error,
                                GQuark         domain,
                                gint           code);

/* if (err) *err = g_error_new(domain, code, format, ...), also has
 * some sanity checks.
 */
GLIB_AVAILABLE_IN_ALL
void     g_set_error           (GError       **err,
                                GQuark         domain,
                                gint           code,
                                const gchar   *format,
                                ...) G_GNUC_PRINTF (4, 5);

GLIB_AVAILABLE_IN_ALL
void     g_set_error_literal   (GError       **err,
                                GQuark         domain,
                                gint           code,
                                const gchar   *message);

/* if (dest) *dest = src; also has some sanity checks.
 */
GLIB_AVAILABLE_IN_ALL
void     g_propagate_error     (GError       **dest,
				GError        *src);

/* if (err && *err) { g_error_free(*err); *err = NULL; } */
GLIB_AVAILABLE_IN_ALL
void     g_clear_error         (GError       **err);

/* if (err) prefix the formatted string to the ->message */
GLIB_AVAILABLE_IN_ALL
void     g_prefix_error               (GError       **err,
                                       const gchar   *format,
                                       ...) G_GNUC_PRINTF (2, 3);

/* if (err) prefix the string to the ->message */
GLIB_AVAILABLE_IN_2_70
void     g_prefix_error_literal       (GError       **err,
                                       const gchar   *prefix);

/* g_propagate_error then g_error_prefix on dest */
GLIB_AVAILABLE_IN_ALL
void     g_propagate_prefixed_error   (GError       **dest,
                                       GError        *src,
                                       const gchar   *format,
                                       ...) G_GNUC_PRINTF (3, 4);

G_END_DECLS

#endif /* __G_ERROR_H__ */