GError implementation

[Havoc Pennington <hp redhat com>]

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/* gerror.h - Error reporting system
 *
 *  Copyright 2000 Red Hat, Inc.
 *
 * The Gnome Library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * The Gnome 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with the Gnome Library; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 *   Boston, MA 02111-1307, USA.
 */

#ifndef __GERROR_H__
#define __GERROR_H__

#ifdef __cplusplus
extern "C"
{
#endif

typedef struct _GError GError;

struct _GError
{
  GQuark       module;
  gint         code;
  const gchar *str;
  gpointer     data;
};

#define g_error_matches(error,mod,num) (error && error->module == (mod) && error->code == (num))

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


GError*  g_error_new_with_data (GQuark         module,
                                gint           code,
                                gpointer       data,
                                GDestroyNotify dnotify,
                                GDataCopyFunc  copyfunc,
                                const gchar   *format,
                                ...) G_GNUC_PRINTF (6, 7);

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

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

void     g_error_set_with_data (GError       **err,
                                GQuark         module,
                                gint           code,
                                gpointer       data,
                                GDestroyNotify dnotify,
                                GDataCopyFunc  copyfunc,
                                const gchar   *format,
                                ...) G_GNUC_PRINTF (7, 8);

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


#ifdef __cplusplus
}
#endif

#endif /* GERROR_H */

/* 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 Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library 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 1997-1999.  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 "glib.h"

typedef struct _GRealError GRealError;

struct _GRealError
{
  GQuark         module;
  gint           code;
  gchar         *str;
  gpointer       data;
  GDestroyNotify dnotify;
  GDataCopyFunc  copyfunc;
};

static GError* 
g_error_new_valist(GQuark         module,
                   gint           code,
                   gpointer       data,
                   GDestroyNotify dnotify,
                   GDataCopyFunc  copyfunc,
                   const gchar   *fmt,
                   va_list        args)
{
  GRealError *real;
  
  real = g_new (GRealError, 1);

  real->module = module;
  real->code = code;

  if (fmt)
    real->str = g_strdup_vprintf (fmt, args);
  else
    real->str = NULL;
  
  real->data = data;
  real->dnotify = dnotify;
  real->copyfunc = copyfunc;
  
  return (GError *) real;
}

GError*
g_error_new (GQuark       module,
             gint         code,
             const gchar *format,
             ...)
{
  GError* error;
  va_list args;
  
  va_start (args, format);
  error = g_error_new_valist (module, code, NULL, NULL, NULL, format, args);
  va_end (args);

  return error;
}


GError*
g_error_new_with_data (GQuark         module,
                       gint           code,
                       gpointer       data,
                       GDestroyNotify dnotify,
                       GDataCopyFunc  copyfunc,
                       const gchar   *format,
                       ...)
{
  GError* error;
  va_list args;
  
  va_start (args, format);
  error = g_error_new_valist (module, code, data, dnotify, copyfunc, format, args);
  va_end (args);

  return error;
}

void
g_error_free (GError *error)
{
  GRealError *real;

  g_return_if_fail (error != NULL);
  
  real = (GRealError *) error;

  if (real->dnotify)
    (* real->dnotify) (real->data);

  g_free (real->str);

  g_free (real);
}

GError*
g_error_copy (const GError *error)
{
  GRealError *real;
  GRealError *copy;
  
  g_return_val_if_fail (error != NULL, NULL);

  real = (GRealError *) error;
  copy = g_new (GRealError, 1);

  *copy = *real;

  /* If we have a copyfunc, use it, otherwise we copy by value
   * and hope it makes sense.
   */
  if (real->copyfunc)
    copy->data = (* real->copyfunc) (real->data);

  copy->str = g_strdup (real->str);

  return (GError *) copy;
}

static void
g_error_set_valist (GError       **err,
                    GQuark         module,
                    gint           code,
                    gpointer       data,
                    GDestroyNotify dnotify,
                    GDataCopyFunc  copyfunc,
                    const gchar   *format,
                    va_list        args)
{
  GError* obj;

  if (err == NULL)
    return;
  
  if (*err != NULL)
    g_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.");
  
  obj = g_error_new_valist (module, code, data, dnotify, copyfunc, format, args);

  *err = obj;
}

void
g_error_set (GError     **err,
             GQuark       module,
             gint         code,
             const gchar *format,
             ...)
{
  va_list args;

  if (err == NULL) /* optimization, duplicates code in set_valist */
    return;
  
  va_start (args, format);
  g_error_set_valist (err, module, code, NULL, NULL, NULL, format, args);
  va_end (args);
}

void
g_error_set_with_data (GError       **err,
                       GQuark         module,
                       gint           code,
                       gpointer       data,
                       GDestroyNotify dnotify,
                       GDataCopyFunc  copyfunc,
                       const gchar   *format,
                       ...)
{
  va_list args;

  if (err == NULL) /* optimization, duplicates code in set_valist */
    return;
  
  va_start (args, format);
  g_error_set_valist (err, module, code, data, dnotify, copyfunc, format, args);
  va_end (args);
}


void
g_error_clear (GError **err)
{
  if (err && *err)
    {
      g_error_free (*err);
      *err = NULL;
    }
}