glib/gerror.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   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 of the License, or (at your option) any later version.
   8  *
   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.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #include "config.h"
  28
  29 #include "glib.h"
  30 #include "galias.h"
  31
  32
  33 /**
  34  * g_error_new_valist:
  35  * @domain: error domain
  36  * @code: error code
  37  * @format: printf()-style format for error message
  38  * @args: #va_list of parameters for the message format
  39  *
  40  * Creates a new #GError with the given @domain and @code,
  41  * and a message formatted with @format.
  42  *
  43  * Returns: a new #GError
  44  *
  45  * Since: 2.22
  46  */
  47 GError*
  48 g_error_new_valist (GQuark       domain,
  49                     gint         code,
  50                     const gchar *format,
  51                     va_list      args)
  52 {
  53   GError *error;
  54
  55   error = g_slice_new (GError);
  56
  57   error->domain = domain;
  58   error->code = code;
  59   error->message = g_strdup_vprintf (format, args);
  60
  61   return error;
  62 }
  63
  64 /**
  65  * g_error_new:
  66  * @domain: error domain
  67  * @code: error code
  68  * @format: printf()-style format for error message
  69  * @Varargs: parameters for message format
  70  *
  71  * Creates a new #GError with the given @domain and @code,
  72  * and a message formatted with @format.
  73  *
  74  * Return value: a new #GError
  75  */
  76 GError*
  77 g_error_new (GQuark       domain,
  78              gint         code,
  79              const gchar *format,
  80              ...)
  81 {
  82   GError* error;
  83   va_list args;
  84
  85   g_return_val_if_fail (format != NULL, NULL);
  86   g_return_val_if_fail (domain != 0, NULL);
  87
  88   va_start (args, format);
  89   error = g_error_new_valist (domain, code, format, args);
  90   va_end (args);
  91
  92   return error;
  93 }
  94
  95 /**
  96  * g_error_new_literal:
  97  * @domain: error domain
  98  * @code: error code
  99  * @message: error message
 100  *
 101  * Creates a new #GError; unlike g_error_new(), @message is
 102  * not a printf()-style format string. Use this function if
 103  * @message contains text you don't have control over,
 104  * that could include printf() escape sequences.
 105  *
 106  * Return value: a new #GError
 107  **/
 108 GError*
 109 g_error_new_literal (GQuark         domain,
 110                      gint           code,
 111                      const gchar   *message)
 112 {
 113   GError* err;
 114
 115   g_return_val_if_fail (message != NULL, NULL);
 116   g_return_val_if_fail (domain != 0, NULL);
 117
 118   err = g_slice_new (GError);
 119
 120   err->domain = domain;
 121   err->code = code;
 122   err->message = g_strdup (message);
 123
 124   return err;
 125 }
 126
 127 /**
 128  * g_error_free:
 129  * @error: a #GError
 130  *
 131  * Frees a #GError and associated resources.
 132  */
 133 void
 134 g_error_free (GError *error)
 135 {
 136   g_return_if_fail (error != NULL);
 137
 138   g_free (error->message);
 139
 140   g_slice_free (GError, error);
 141 }
 142
 143 /**
 144  * g_error_copy:
 145  * @error: a #GError
 146  *
 147  * Makes a copy of @error.
 148  *
 149  * Return value: a new #GError
 150  */
 151 GError*
 152 g_error_copy (const GError *error)
 153 {
 154   GError *copy;
 155
 156   g_return_val_if_fail (error != NULL, NULL);
 157
 158   copy = g_slice_new (GError);
 159
 160   *copy = *error;
 161
 162   copy->message = g_strdup (error->message);
 163
 164   return copy;
 165 }
 166
 167 /**
 168  * g_error_matches:
 169  * @error: a #GError or %NULL
 170  * @domain: an error domain
 171  * @code: an error code
 172  *
 173  * Returns %TRUE if @error matches @domain and @code, %FALSE
 174  * otherwise. In particular, when @error is %NULL, %FALSE will
 175  * be returned.
 176  *
 177  * Return value: whether @error has @domain and @code
 178  */
 179 gboolean
 180 g_error_matches (const GError *error,
 181                  GQuark        domain,
 182                  gint          code)
 183 {
 184   return error &&
 185     error->domain == domain &&
 186     error->code == code;
 187 }
 188
 189 #define ERROR_OVERWRITTEN_WARNING "GError set over the top of a previous GError or uninitialized memory.\n" \
 190                "This indicates a bug in someone's code. You must ensure an error is NULL before it's set.\n" \
 191                "The overwriting error message was: %s"
 192
 193 /**
 194  * g_set_error:
 195  * @err: a return location for a #GError, or %NULL
 196  * @domain: error domain
 197  * @code: error code
 198  * @format: printf()-style format
 199  * @Varargs: args for @format
 200  *
 201  * Does nothing if @err is %NULL; if @err is non-%NULL, then *@err
 202  * must be %NULL. A new #GError is created and assigned to *@err.
 203  */
 204 void
 205 g_set_error (GError      **err,
 206              GQuark        domain,
 207              gint          code,
 208              const gchar  *format,
 209              ...)
 210 {
 211   GError *new;
 212
 213   va_list args;
 214
 215   if (err == NULL)
 216     return;
 217
 218   va_start (args, format);
 219   new = g_error_new_valist (domain, code, format, args);
 220   va_end (args);
 221
 222   if (*err == NULL)
 223     *err = new;
 224   else
 225     g_warning (ERROR_OVERWRITTEN_WARNING, new->message);
 226 }
 227
 228 /**
 229  * g_set_error_literal:
 230  * @err: a return location for a #GError, or %NULL
 231  * @domain: error domain
 232  * @code: error code
 233  * @message: error message
 234  *
 235  * Does nothing if @err is %NULL; if @err is non-%NULL, then *@err
 236  * must be %NULL. A new #GError is created and assigned to *@err.
 237  * Unlike g_set_error(), @message is not a printf()-style format string.
 238  * Use this function if @message contains text you don't have control over,
 239  * that could include printf() escape sequences.
 240  *
 241  * Since: 2.18
 242  */
 243 void
 244 g_set_error_literal (GError      **err,
 245                      GQuark        domain,
 246                      gint          code,
 247                      const gchar  *message)
 248 {
 249   GError *new;
 250
 251   if (err == NULL)
 252     return;
 253
 254   new = g_error_new_literal (domain, code, message);
 255   if (*err == NULL)
 256     *err = new;
 257   else
 258     g_warning (ERROR_OVERWRITTEN_WARNING, new->message);
 259 }
 260
 261 /**
 262  * g_propagate_error:
 263  * @dest: error return location
 264  * @src: error to move into the return location
 265  *
 266  * If @dest is %NULL, free @src; otherwise, moves @src into *@dest.
 267  * The error variable @dest points to must be %NULL.
 268  */
 269 void
 270 g_propagate_error (GError **dest,
 271                    GError  *src)
 272 {
 273   g_return_if_fail (src != NULL);
 274
 275   if (dest == NULL)
 276     {
 277       if (src)
 278         g_error_free (src);
 279       return;
 280     }
 281   else
 282     {
 283       if (*dest != NULL)
 284         g_warning (ERROR_OVERWRITTEN_WARNING, src->message);
 285       else
 286         *dest = src;
 287     }
 288 }
 289
 290 /**
 291  * g_clear_error:
 292  * @err: a #GError return location
 293  *
 294  * If @err is %NULL, does nothing. If @err is non-%NULL,
 295  * calls g_error_free() on *@err and sets *@err to %NULL.
 296  */
 297 void
 298 g_clear_error (GError **err)
 299 {
 300   if (err && *err)
 301     {
 302       g_error_free (*err);
 303       *err = NULL;
 304     }
 305 }
 306
 307 static void
 308 g_error_add_prefix (gchar       **string,
 309                     const gchar  *format,
 310                     va_list       ap)
 311 {
 312   gchar *oldstring;
 313   gchar *prefix;
 314
 315   prefix = g_strdup_vprintf (format, ap);
 316   oldstring = *string;
 317   *string = g_strconcat (prefix, oldstring, NULL);
 318   g_free (oldstring);
 319   g_free (prefix);
 320 }
 321
 322 /**
 323  * g_prefix_error:
 324  * @err: a return location for a #GError, or %NULL
 325  * @format: printf()-style format string
 326  * @...: arguments to @format
 327  *
 328  * Formats a string according to @format and
 329  * prefix it to an existing error message.  If
 330  * @err is %NULL (ie: no error variable) then do
 331  * nothing.
 332  *
 333  * If *@err is %NULL (ie: an error variable is
 334  * present but there is no error condition) then
 335  * also do nothing.  Whether or not it makes
 336  * sense to take advantage of this feature is up
 337  * to you.
 338  *
 339  * Since: 2.16
 340  */
 341 void
 342 g_prefix_error (GError      **err,
 343                 const gchar  *format,
 344                 ...)
 345 {
 346   if (err && *err)
 347     {
 348       va_list ap;
 349
 350       va_start (ap, format);
 351       g_error_add_prefix (&(*err)->message, format, ap);
 352       va_end (ap);
 353     }
 354 }
 355
 356 /**
 357  * g_propagate_prefixed_error:
 358  * @dest: error return location
 359  * @src: error to move into the return location
 360  * @format: printf()-style format string
 361  * @...: arguments to @format
 362  *
 363  * If @dest is %NULL, free @src; otherwise,
 364  * moves @src into *@dest. *@dest must be %NULL.
 365  * After the move, add a prefix as with
 366  * g_prefix_error().
 367  *
 368  * Since: 2.16
 369  **/
 370 void
 371 g_propagate_prefixed_error (GError      **dest,
 372                             GError       *src,
 373                             const gchar  *format,
 374                             ...)
 375 {
 376   g_propagate_error (dest, src);
 377
 378   if (dest && *dest)
 379     {
 380       va_list ap;
 381
 382       va_start (ap, format);
 383       g_error_add_prefix (&(*dest)->message, format, ap);
 384       va_end (ap);
 385     }
 386 }
 387
 388 #define __G_ERROR_C__
 389 #include "galiasdef.c"