glib/glib/gerror.c

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * 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 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, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
 * file for a list of people on the GLib Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GLib at ftp://ftp.gtk.org/pub/gtk/.
 */

#include "config.h"

#include "glib.h"
#include "galias.h"


/**
 * g_error_new_valist:
 * @domain: error domain
 * @code: error code
 * @format: printf()-style format for error message
 * @args: #va_list of parameters for the message format
 *
 * Creates a new #GError with the given @domain and @code,
 * and a message formatted with @format.
 *
 * Returns: a new #GError
 *
 * Since: 2.22
 */
GError*
g_error_new_valist (GQuark       domain,
                    gint         code,
                    const gchar *format,
                    va_list      args)
{
  GError *error;

  error = g_slice_new (GError);

  error->domain = domain;
  error->code = code;
  error->message = g_strdup_vprintf (format, args);

  return error;
}

/**
 * g_error_new:
 * @domain: error domain
 * @code: error code
 * @format: printf()-style format for error message
 * @Varargs: parameters for message format
 *
 * Creates a new #GError with the given @domain and @code,
 * and a message formatted with @format.
 *
 * Return value: a new #GError
 */
GError*
g_error_new (GQuark       domain,
             gint         code,
             const gchar *format,
             ...)
{
  GError* error;
  va_list args;

  g_return_val_if_fail (format != NULL, NULL);
  g_return_val_if_fail (domain != 0, NULL);

  va_start (args, format);
  error = g_error_new_valist (domain, code, format, args);
  va_end (args);

  return error;
}

/**
 * g_error_new_literal:
 * @domain: error domain
 * @code: error code
 * @message: error message
 *
 * Creates a new #GError; unlike g_error_new(), @message is
 * not a printf()-style format string. Use this function if
 * @message contains text you don't have control over,
 * that could include printf() escape sequences.
 *
 * Return value: a new #GError
 **/
GError*
g_error_new_literal (GQuark         domain,
                     gint           code,
                     const gchar   *message)
{
  GError* err;

  g_return_val_if_fail (message != NULL, NULL);
  g_return_val_if_fail (domain != 0, NULL);

  err = g_slice_new (GError);

  err->domain = domain;
  err->code = code;
  err->message = g_strdup (message);

  return err;
}

/**
 * g_error_free:
 * @error: a #GError
 *
 * Frees a #GError and associated resources.
 */
void
g_error_free (GError *error)
{
  g_return_if_fail (error != NULL);

  g_free (error->message);

  g_slice_free (GError, error);
}

/**
 * g_error_copy:
 * @error: a #GError
 *
 * Makes a copy of @error.
 *
 * Return value: a new #GError
 */
GError*
g_error_copy (const GError *error)
{
  GError *copy;
 
  g_return_val_if_fail (error != NULL, NULL);

  copy = g_slice_new (GError);

  *copy = *error;

  copy->message = g_strdup (error->message);

  return copy;
}

/**
 * g_error_matches:
 * @error: a #GError or %NULL
 * @domain: an error domain
 * @code: an error code
 *
 * Returns %TRUE if @error matches @domain and @code, %FALSE
 * otherwise. In particular, when @error is %NULL, %FALSE will
 * be returned.
 *
 * Return value: whether @error has @domain and @code
 */
gboolean
g_error_matches (const GError *error,
                 GQuark        domain,
                 gint          code)
{
  return error &&
    error->domain == domain &&
    error->code == code;
}

#define ERROR_OVERWRITTEN_WARNING "GError set over the top of a previous GError or uninitialized memory.\n" \
               "This indicates a bug in someone's code. You must ensure an error is NULL before it's set.\n" \
               "The overwriting error message was: %s"

/**
 * g_set_error:
 * @err: a return location for a #GError, or %NULL
 * @domain: error domain
 * @code: error code
 * @format: printf()-style format
 * @Varargs: args for @format
 *
 * Does nothing if @err is %NULL; if @err is non-%NULL, then *@err
 * must be %NULL. A new #GError is created and assigned to *@err.
 */
void
g_set_error (GError      **err,
             GQuark        domain,
             gint          code,
             const gchar  *format,
             ...)
{
  GError *new;

  va_list args;

  if (err == NULL)
    return;

  va_start (args, format);
  new = g_error_new_valist (domain, code, format, args);
  va_end (args);

  if (*err == NULL)
    *err = new;
  else
    g_warning (ERROR_OVERWRITTEN_WARNING, new->message); 
}

/**
 * g_set_error_literal:
 * @err: a return location for a #GError, or %NULL
 * @domain: error domain
 * @code: error code
 * @message: error message
 *
 * Does nothing if @err is %NULL; if @err is non-%NULL, then *@err
 * must be %NULL. A new #GError is created and assigned to *@err.
 * Unlike g_set_error(), @message is not a printf()-style format string.
 * Use this function if @message contains text you don't have control over,
 * that could include printf() escape sequences.
 *
 * Since: 2.18
 */
void
g_set_error_literal (GError      **err,
                     GQuark        domain,
                     gint          code,
                     const gchar  *message)
{
  GError *new;

  if (err == NULL)
    return;

  new = g_error_new_literal (domain, code, message);
  if (*err == NULL)
    *err = new;
  else
    g_warning (ERROR_OVERWRITTEN_WARNING, new->message); 
}

/**
 * g_propagate_error:
 * @dest: error return location
 * @src: error to move into the return location
 *
 * If @dest is %NULL, free @src; otherwise, moves @src into *@dest.
 * The error variable @dest points to must be %NULL.
 */
void
g_propagate_error (GError **dest,
		   GError  *src)
{
  g_return_if_fail (src != NULL);
 
  if (dest == NULL)
    {
      if (src)
        g_error_free (src);
      return;
    }
  else
    {
      if (*dest != NULL)
        g_warning (ERROR_OVERWRITTEN_WARNING, src->message);
      else
        *dest = src;
    }
}

/**
 * g_clear_error:
 * @err: a #GError return location
 *
 * If @err is %NULL, does nothing. If @err is non-%NULL,
 * calls g_error_free() on *@err and sets *@err to %NULL.
 */
void
g_clear_error (GError **err)
{
  if (err && *err)
    {
      g_error_free (*err);
      *err = NULL;
    }
}

static void
g_error_add_prefix (gchar       **string,
                    const gchar  *format,
                    va_list       ap)
{
  gchar *oldstring;
  gchar *prefix;

  prefix = g_strdup_vprintf (format, ap);
  oldstring = *string;
  *string = g_strconcat (prefix, oldstring, NULL);
  g_free (oldstring);
  g_free (prefix);
}

/**
 * g_prefix_error:
 * @err: a return location for a #GError, or %NULL
 * @format: printf()-style format string
 * @...: arguments to @format
 *
 * Formats a string according to @format and
 * prefix it to an existing error message.  If
 * @err is %NULL (ie: no error variable) then do
 * nothing.
 *
 * If *@err is %NULL (ie: an error variable is
 * present but there is no error condition) then
 * also do nothing.  Whether or not it makes
 * sense to take advantage of this feature is up
 * to you.
 *
 * Since: 2.16
 */
void
g_prefix_error (GError      **err,
                const gchar  *format,
                ...)
{
  if (err && *err)
    {
      va_list ap;

      va_start (ap, format);
      g_error_add_prefix (&(*err)->message, format, ap);
      va_end (ap);
    }
}

/**
 * g_propagate_prefixed_error:
 * @dest: error return location
 * @src: error to move into the return location
 * @format: printf()-style format string
 * @...: arguments to @format
 *
 * If @dest is %NULL, free @src; otherwise,
 * moves @src into *@dest. *@dest must be %NULL.
 * After the move, add a prefix as with
 * g_prefix_error().
 *
 * Since: 2.16
 **/
void
g_propagate_prefixed_error (GError      **dest,
                            GError       *src,
                            const gchar  *format,
                            ...)
{
  g_propagate_error (dest, src);

  if (dest && *dest)
    {
      va_list ap;

      va_start (ap, format);
      g_error_add_prefix (&(*dest)->message, format, ap);
      va_end (ap);
    }
}

#define __G_ERROR_C__
#include "galiasdef.c"