glib/glib/gerror.h
Krzesimir Nowak ae72f9de35 gerror: Add support for extended errors
This commit adds a G_DEFINE_EXTENDED_ERROR macro and
g_error_domain_register() functions to register extended error
domains.
2021-01-06 15:44:59 +00:00

255 lines
11 KiB
C

/* gerror.h - Error reporting system
*
* Copyright 2000 Red Hat, Inc.
*
* 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.
*
* 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);
/* 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__ */