| /* 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 2.1 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/>. |
| */ |
| |
| /* |
| * 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/. |
| */ |
| |
| /** |
| * SECTION:error_reporting |
| * @Title: Error Reporting |
| * @Short_description: a system for reporting errors |
| * |
| * GLib provides a standard method of reporting errors from a called |
| * function to the calling code. (This is the same problem solved by |
| * exceptions in other languages.) It's important to understand that |
| * this method is both a data type (the #GError struct) and a [set of |
| * rules][gerror-rules]. If you use #GError incorrectly, then your code will not |
| * properly interoperate with other code that uses #GError, and users |
| * of your API will probably get confused. In most cases, [using #GError is |
| * preferred over numeric error codes][gerror-comparison], but there are |
| * situations where numeric error codes are useful for performance. |
| * |
| * First and foremost: #GError should only be used to report recoverable |
| * runtime errors, never to report programming errors. If the programmer |
| * has screwed up, then you should use g_warning(), g_return_if_fail(), |
| * g_assert(), g_error(), or some similar facility. (Incidentally, |
| * remember that the g_error() function should only be used for |
| * programming errors, it should not be used to print any error |
| * reportable via #GError.) |
| * |
| * Examples of recoverable runtime errors are "file not found" or |
| * "failed to parse input." Examples of programming errors are "NULL |
| * passed to strcmp()" or "attempted to free the same pointer twice." |
| * These two kinds of errors are fundamentally different: runtime errors |
| * should be handled or reported to the user, programming errors should |
| * be eliminated by fixing the bug in the program. This is why most |
| * functions in GLib and GTK+ do not use the #GError facility. |
| * |
| * Functions that can fail take a return location for a #GError as their |
| * last argument. On error, a new #GError instance will be allocated and |
| * returned to the caller via this argument. For example: |
| * |[<!-- language="C" --> |
| * gboolean g_file_get_contents (const gchar *filename, |
| * gchar **contents, |
| * gsize *length, |
| * GError **error); |
| * ]| |
| * If you pass a non-%NULL value for the `error` argument, it should |
| * point to a location where an error can be placed. For example: |
| * |[<!-- language="C" --> |
| * gchar *contents; |
| * GError *err = NULL; |
| * |
| * g_file_get_contents ("foo.txt", &contents, NULL, &err); |
| * g_assert ((contents == NULL && err != NULL) || (contents != NULL && err == NULL)); |
| * if (err != NULL) |
| * { |
| * // Report error to user, and free error |
| * g_assert (contents == NULL); |
| * fprintf (stderr, "Unable to read file: %s\n", err->message); |
| * g_error_free (err); |
| * } |
| * else |
| * { |
| * // Use file contents |
| * g_assert (contents != NULL); |
| * } |
| * ]| |
| * Note that `err != NULL` in this example is a reliable indicator |
| * of whether g_file_get_contents() failed. Additionally, |
| * g_file_get_contents() returns a boolean which |
| * indicates whether it was successful. |
| * |
| * Because g_file_get_contents() returns %FALSE on failure, if you |
| * are only interested in whether it failed and don't need to display |
| * an error message, you can pass %NULL for the @error argument: |
| * |[<!-- language="C" --> |
| * if (g_file_get_contents ("foo.txt", &contents, NULL, NULL)) // ignore errors |
| * // no error occurred |
| * ; |
| * else |
| * // error |
| * ; |
| * ]| |
| * |
| * The #GError object contains three fields: @domain indicates the module |
| * the error-reporting function is located in, @code indicates the specific |
| * error that occurred, and @message is a user-readable error message with |
| * as many details as possible. Several functions are provided to deal |
| * with an error received from a called function: g_error_matches() |
| * returns %TRUE if the error matches a given domain and code, |
| * g_propagate_error() copies an error into an error location (so the |
| * calling function will receive it), and g_clear_error() clears an |
| * error location by freeing the error and resetting the location to |
| * %NULL. To display an error to the user, simply display the @message, |
| * perhaps along with additional context known only to the calling |
| * function (the file being opened, or whatever - though in the |
| * g_file_get_contents() case, the @message already contains a filename). |
| * |
| * Since error messages may be displayed to the user, they need to be valid |
| * UTF-8 (all GTK widgets expect text to be UTF-8). Keep this in mind in |
| * particular when formatting error messages with filenames, which are in |
| * the 'filename encoding', and need to be turned into UTF-8 using |
| * g_filename_to_utf8(), g_filename_display_name() or g_utf8_make_valid(). |
| * |
| * Note, however, that many error messages are too technical to display to the |
| * user in an application, so prefer to use g_error_matches() to categorize errors |
| * from called functions, and build an appropriate error message for the context |
| * within your application. Error messages from a #GError are more appropriate |
| * to be printed in system logs or on the command line. They are typically |
| * translated. |
| * |
| * When implementing a function that can report errors, the basic |
| * tool is g_set_error(). Typically, if a fatal error occurs you |
| * want to g_set_error(), then return immediately. g_set_error() |
| * does nothing if the error location passed to it is %NULL. |
| * Here's an example: |
| * |[<!-- language="C" --> |
| * gint |
| * foo_open_file (GError **error) |
| * { |
| * gint fd; |
| * int saved_errno; |
| * |
| * g_return_val_if_fail (error == NULL || *error == NULL, -1); |
| * |
| * fd = open ("file.txt", O_RDONLY); |
| * saved_errno = errno; |
| * |
| * if (fd < 0) |
| * { |
| * g_set_error (error, |
| * FOO_ERROR, // error domain |
| * FOO_ERROR_BLAH, // error code |
| * "Failed to open file: %s", // error message format string |
| * g_strerror (saved_errno)); |
| * return -1; |
| * } |
| * else |
| * return fd; |
| * } |
| * ]| |
| * |
| * Things are somewhat more complicated if you yourself call another |
| * function that can report a #GError. If the sub-function indicates |
| * fatal errors in some way other than reporting a #GError, such as |
| * by returning %TRUE on success, you can simply do the following: |
| * |[<!-- language="C" --> |
| * gboolean |
| * my_function_that_can_fail (GError **err) |
| * { |
| * g_return_val_if_fail (err == NULL || *err == NULL, FALSE); |
| * |
| * if (!sub_function_that_can_fail (err)) |
| * { |
| * // assert that error was set by the sub-function |
| * g_assert (err == NULL || *err != NULL); |
| * return FALSE; |
| * } |
| * |
| * // otherwise continue, no error occurred |
| * g_assert (err == NULL || *err == NULL); |
| * } |
| * ]| |
| * |
| * If the sub-function does not indicate errors other than by |
| * reporting a #GError (or if its return value does not reliably indicate |
| * errors) you need to create a temporary #GError |
| * since the passed-in one may be %NULL. g_propagate_error() is |
| * intended for use in this case. |
| * |[<!-- language="C" --> |
| * gboolean |
| * my_function_that_can_fail (GError **err) |
| * { |
| * GError *tmp_error; |
| * |
| * g_return_val_if_fail (err == NULL || *err == NULL, FALSE); |
| * |
| * tmp_error = NULL; |
| * sub_function_that_can_fail (&tmp_error); |
| * |
| * if (tmp_error != NULL) |
| * { |
| * // store tmp_error in err, if err != NULL, |
| * // otherwise call g_error_free() on tmp_error |
| * g_propagate_error (err, tmp_error); |
| * return FALSE; |
| * } |
| * |
| * // otherwise continue, no error occurred |
| * } |
| * ]| |
| * |
| * Error pileups are always a bug. For example, this code is incorrect: |
| * |[<!-- language="C" --> |
| * gboolean |
| * my_function_that_can_fail (GError **err) |
| * { |
| * GError *tmp_error; |
| * |
| * g_return_val_if_fail (err == NULL || *err == NULL, FALSE); |
| * |
| * tmp_error = NULL; |
| * sub_function_that_can_fail (&tmp_error); |
| * other_function_that_can_fail (&tmp_error); |
| * |
| * if (tmp_error != NULL) |
| * { |
| * g_propagate_error (err, tmp_error); |
| * return FALSE; |
| * } |
| * } |
| * ]| |
| * @tmp_error should be checked immediately after sub_function_that_can_fail(), |
| * and either cleared or propagated upward. The rule is: after each error, |
| * you must either handle the error, or return it to the calling function. |
| * |
| * Note that passing %NULL for the error location is the equivalent |
| * of handling an error by always doing nothing about it. So the |
| * following code is fine, assuming errors in sub_function_that_can_fail() |
| * are not fatal to my_function_that_can_fail(): |
| * |[<!-- language="C" --> |
| * gboolean |
| * my_function_that_can_fail (GError **err) |
| * { |
| * GError *tmp_error; |
| * |
| * g_return_val_if_fail (err == NULL || *err == NULL, FALSE); |
| * |
| * sub_function_that_can_fail (NULL); // ignore errors |
| * |
| * tmp_error = NULL; |
| * other_function_that_can_fail (&tmp_error); |
| * |
| * if (tmp_error != NULL) |
| * { |
| * g_propagate_error (err, tmp_error); |
| * return FALSE; |
| * } |
| * } |
| * ]| |
| * |
| * Note that passing %NULL for the error location ignores errors; |
| * it's equivalent to |
| * `try { sub_function_that_can_fail (); } catch (...) {}` |
| * in C++. It does not mean to leave errors unhandled; it means |
| * to handle them by doing nothing. |
| * |
| * Error domains and codes are conventionally named as follows: |
| * |
| * - The error domain is called <NAMESPACE>_<MODULE>_ERROR, |
| * for example %G_SPAWN_ERROR or %G_THREAD_ERROR: |
| * |[<!-- language="C" --> |
| * #define G_SPAWN_ERROR g_spawn_error_quark () |
| * |
| * G_DEFINE_QUARK (g-spawn-error-quark, g_spawn_error) |
| * ]| |
| * |
| * - The quark function for the error domain is called |
| * <namespace>_<module>_error_quark, |
| * for example g_spawn_error_quark() or g_thread_error_quark(). |
| * |
| * - The error codes are in an enumeration called |
| * <Namespace><Module>Error; |
| * for example, #GThreadError or #GSpawnError. |
| * |
| * - Members of the error code enumeration are called |
| * <NAMESPACE>_<MODULE>_ERROR_<CODE>, |
| * for example %G_SPAWN_ERROR_FORK or %G_THREAD_ERROR_AGAIN. |
| * |
| * - If there's a "generic" or "unknown" error code for unrecoverable |
| * errors it doesn't make sense to distinguish with specific codes, |
| * it should be called <NAMESPACE>_<MODULE>_ERROR_FAILED, |
| * for example %G_SPAWN_ERROR_FAILED. In the case of error code |
| * enumerations that may be extended in future releases, you should |
| * generally not handle this error code explicitly, but should |
| * instead treat any unrecognized error code as equivalent to |
| * FAILED. |
| * |
| * ## Comparison of #GError and traditional error handling # {#gerror-comparison} |
| * |
| * #GError has several advantages over traditional numeric error codes: |
| * importantly, tools like |
| * [gobject-introspection](https://developer.gnome.org/gi/stable/) understand |
| * #GErrors and convert them to exceptions in bindings; the message includes |
| * more information than just a code; and use of a domain helps prevent |
| * misinterpretation of error codes. |
| * |
| * #GError has disadvantages though: it requires a memory allocation, and |
| * formatting the error message string has a performance overhead. This makes it |
| * unsuitable for use in retry loops where errors are a common case, rather than |
| * being unusual. For example, using %G_IO_ERROR_WOULD_BLOCK means hitting these |
| * overheads in the normal control flow. String formatting overhead can be |
| * eliminated by using g_set_error_literal() in some cases. |
| * |
| * These performance issues can be compounded if a function wraps the #GErrors |
| * returned by the functions it calls: this multiplies the number of allocations |
| * and string formatting operations. This can be partially mitigated by using |
| * g_prefix_error(). |
| * |
| * ## Rules for use of #GError # {#gerror-rules} |
| * |
| * Summary of rules for use of #GError: |
| * |
| * - Do not report programming errors via #GError. |
| * |
| * - The last argument of a function that returns an error should |
| * be a location where a #GError can be placed (i.e. `GError **error`). |
| * If #GError is used with varargs, the `GError**` should be the last |
| * argument before the `...`. |
| * |
| * - The caller may pass %NULL for the `GError**` if they are not interested |
| * in details of the exact error that occurred. |
| * |
| * - If %NULL is passed for the `GError**` argument, then errors should |
| * not be returned to the caller, but your function should still |
| * abort and return if an error occurs. That is, control flow should |
| * not be affected by whether the caller wants to get a #GError. |
| * |
| * - If a #GError is reported, then your function by definition had a |
| * fatal failure and did not complete whatever it was supposed to do. |
| * If the failure was not fatal, then you handled it and you should not |
| * report it. If it was fatal, then you must report it and discontinue |
| * whatever you were doing immediately. |
| * |
| * - If a #GError is reported, out parameters are not guaranteed to |
| * be set to any defined value. |
| * |
| * - A `GError*` must be initialized to %NULL before passing its address |
| * to a function that can report errors. |
| * |
| * - #GError structs must not be stack-allocated. |
| * |
| * - "Piling up" errors is always a bug. That is, if you assign a |
| * new #GError to a `GError*` that is non-%NULL, thus overwriting |
| * the previous error, it indicates that you should have aborted |
| * the operation instead of continuing. If you were able to continue, |
| * you should have cleared the previous error with g_clear_error(). |
| * g_set_error() will complain if you pile up errors. |
| * |
| * - By convention, if you return a boolean value indicating success |
| * then %TRUE means success and %FALSE means failure. Avoid creating |
| * functions which have a boolean return value and a #GError parameter, |
| * but where the boolean does something other than signal whether the |
| * #GError is set. Among other problems, it requires C callers to allocate |
| * a temporary error. Instead, provide a `gboolean *` out parameter. |
| * There are functions in GLib itself such as g_key_file_has_key() that |
| * are hard to use because of this. If %FALSE is returned, the error must |
| * be set to a non-%NULL value. One exception to this is that in situations |
| * that are already considered to be undefined behaviour (such as when a |
| * g_return_val_if_fail() check fails), the error need not be set. |
| * Instead of checking separately whether the error is set, callers |
| * should ensure that they do not provoke undefined behaviour, then |
| * assume that the error will be set on failure. |
| * |
| * - A %NULL return value is also frequently used to mean that an error |
| * occurred. You should make clear in your documentation whether %NULL |
| * is a valid return value in non-error cases; if %NULL is a valid value, |
| * then users must check whether an error was returned to see if the |
| * function succeeded. |
| * |
| * - When implementing a function that can report errors, you may want |
| * to add a check at the top of your function that the error return |
| * location is either %NULL or contains a %NULL error (e.g. |
| * `g_return_if_fail (error == NULL || *error == NULL);`). |
| * |
| * ## Extended #GError Domains # {#gerror-extended-domains} |
| * |
| * Since GLib 2.68 it is possible to extend the #GError type. This is |
| * done with the G_DEFINE_EXTENDED_ERROR() macro. To create an |
| * extended #GError type do something like this in the header file: |
| * |[<!-- language="C" --> |
| * typedef enum |
| * { |
| * MY_ERROR_BAD_REQUEST, |
| * } MyError; |
| * #define MY_ERROR (my_error_quark ()) |
| * GQuark my_error_quark (void); |
| * int |
| * my_error_get_parse_error_id (GError *error); |
| * const char * |
| * my_error_get_bad_request_details (GError *error); |
| * ]| |
| * and in implementation: |
| * |[<!-- language="C" --> |
| * typedef struct |
| * { |
| * int parse_error_id; |
| * char *bad_request_details; |
| * } MyErrorPrivate; |
| * |
| * static void |
| * my_error_private_init (MyErrorPrivate *priv) |
| * { |
| * priv->parse_error_id = -1; |
| * // No need to set priv->bad_request_details to NULL, |
| * // the struct is initialized with zeros. |
| * } |
| * |
| * static void |
| * my_error_private_copy (const MyErrorPrivate *src_priv, MyErrorPrivate *dest_priv) |
| * { |
| * dest_priv->parse_error_id = src_priv->parse_error_id; |
| * dest_priv->bad_request_details = g_strdup (src_priv->bad_request_details); |
| * } |
| * |
| * static void |
| * my_error_private_clear (MyErrorPrivate *priv) |
| * { |
| * g_free (priv->bad_request_details); |
| * } |
| * |
| * // This defines the my_error_get_private and my_error_quark functions. |
| * G_DEFINE_EXTENDED_ERROR (MyError, my_error) |
| * |
| * int |
| * my_error_get_parse_error_id (GError *error) |
| * { |
| * MyErrorPrivate *priv = my_error_get_private (error); |
| * g_return_val_if_fail (priv != NULL, -1); |
| * return priv->parse_error_id; |
| * } |
| * |
| * const char * |
| * my_error_get_bad_request_details (GError *error) |
| * { |
| * MyErrorPrivate *priv = my_error_get_private (error); |
| * g_return_val_if_fail (priv != NULL, NULL); |
| * g_return_val_if_fail (error->code != MY_ERROR_BAD_REQUEST, NULL); |
| * return priv->bad_request_details; |
| * } |
| * |
| * static void |
| * my_error_set_bad_request (GError **error, |
| * const char *reason, |
| * int error_id, |
| * const char *details) |
| * { |
| * MyErrorPrivate *priv; |
| * g_set_error (error, MY_ERROR, MY_ERROR_BAD_REQUEST, "Invalid request: %s", reason); |
| * if (error != NULL && *error != NULL) |
| * { |
| * priv = my_error_get_private (error); |
| * g_return_val_if_fail (priv != NULL, NULL); |
| * priv->parse_error_id = error_id; |
| * priv->bad_request_details = g_strdup (details); |
| * } |
| * } |
| * ]| |
| * An example of use of the error could be: |
| * |[<!-- language="C" --> |
| * gboolean |
| * send_request (GBytes *request, GError **error) |
| * { |
| * ParseFailedStatus *failure = validate_request (request); |
| * if (failure != NULL) |
| * { |
| * my_error_set_bad_request (error, failure->reason, failure->error_id, failure->details); |
| * parse_failed_status_free (failure); |
| * return FALSE; |
| * } |
| * |
| * return send_one (request, error); |
| * } |
| * ]| |
| * |
| * Please note that if you are a library author and your library |
| * exposes an existing error domain, then you can't make this error |
| * domain an extended one without breaking ABI. This is because |
| * earlier it was possible to create an error with this error domain |
| * on the stack and then copy it with g_error_copy(). If the new |
| * version of your library makes the error domain an extended one, |
| * then g_error_copy() called by code that allocated the error on the |
| * stack will try to copy more data than it used to, which will lead |
| * to undefined behavior. You must not stack-allocate errors with an |
| * extended error domain, and it is bad practice to stack-allocate any |
| * other #GErrors. |
| * |
| * Extended error domains in unloadable plugins/modules are not |
| * supported. |
| */ |
| |
| #include "config.h" |
| |
| #include "gvalgrind.h" |
| #include <string.h> |
| |
| #include "gerror.h" |
| |
| #include "ghash.h" |
| #include "glib-init.h" |
| #include "gslice.h" |
| #include "gstrfuncs.h" |
| #include "gtestutils.h" |
| #include "gthread.h" |
| |
| static GRWLock error_domain_global; |
| /* error_domain_ht must be accessed with error_domain_global |
| * locked. |
| */ |
| static GHashTable *error_domain_ht = NULL; |
| |
| void |
| g_error_init (void) |
| { |
| error_domain_ht = g_hash_table_new (NULL, NULL); |
| } |
| |
| typedef struct |
| { |
| /* private_size is already aligned. */ |
| gsize private_size; |
| GErrorInitFunc init; |
| GErrorCopyFunc copy; |
| GErrorClearFunc clear; |
| } ErrorDomainInfo; |
| |
| /* Must be called with error_domain_global locked. |
| */ |
| static inline ErrorDomainInfo * |
| error_domain_lookup (GQuark domain) |
| { |
| return g_hash_table_lookup (error_domain_ht, |
| GUINT_TO_POINTER (domain)); |
| } |
| |
| /* Copied from gtype.c. */ |
| #define STRUCT_ALIGNMENT (2 * sizeof (gsize)) |
| #define ALIGN_STRUCT(offset) \ |
| ((offset + (STRUCT_ALIGNMENT - 1)) & -STRUCT_ALIGNMENT) |
| |
| static void |
| error_domain_register (GQuark error_quark, |
| gsize error_type_private_size, |
| GErrorInitFunc error_type_init, |
| GErrorCopyFunc error_type_copy, |
| GErrorClearFunc error_type_clear) |
| { |
| g_rw_lock_writer_lock (&error_domain_global); |
| if (error_domain_lookup (error_quark) == NULL) |
| { |
| ErrorDomainInfo *info = g_new (ErrorDomainInfo, 1); |
| info->private_size = ALIGN_STRUCT (error_type_private_size); |
| info->init = error_type_init; |
| info->copy = error_type_copy; |
| info->clear = error_type_clear; |
| |
| g_hash_table_insert (error_domain_ht, |
| GUINT_TO_POINTER (error_quark), |
| info); |
| } |
| else |
| { |
| const char *name = g_quark_to_string (error_quark); |
| |
| g_critical ("Attempted to register an extended error domain for %s more than once", name); |
| } |
| g_rw_lock_writer_unlock (&error_domain_global); |
| } |
| |
| /** |
| * g_error_domain_register_static: |
| * @error_type_name: static string to create a #GQuark from |
| * @error_type_private_size: size of the private error data in bytes |
| * @error_type_init: function initializing fields of the private error data |
| * @error_type_copy: function copying fields of the private error data |
| * @error_type_clear: function freeing fields of the private error data |
| * |
| * This function registers an extended #GError domain. |
| * |
| * @error_type_name should not be freed. @error_type_private_size must |
| * be greater than 0. |
| * |
| * @error_type_init receives an initialized #GError and should then initialize |
| * the private data. |
| * |
| * @error_type_copy is a function that receives both original and a copy |
| * #GError and should copy the fields of the private error data. The standard |
| * #GError fields are already handled. |
| * |
| * @error_type_clear receives the pointer to the error, and it should free the |
| * fields of the private error data. It should not free the struct itself though. |
| * |
| * Normally, it is better to use G_DEFINE_EXTENDED_ERROR(), as it |
| * already takes care of passing valid information to this function. |
| * |
| * Returns: #GQuark representing the error domain |
| * Since: 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) |
| { |
| GQuark error_quark; |
| |
| g_return_val_if_fail (error_type_name != NULL, 0); |
| g_return_val_if_fail (error_type_private_size > 0, 0); |
| g_return_val_if_fail (error_type_init != NULL, 0); |
| g_return_val_if_fail (error_type_copy != NULL, 0); |
| g_return_val_if_fail (error_type_clear != NULL, 0); |
| |
| error_quark = g_quark_from_static_string (error_type_name); |
| error_domain_register (error_quark, |
| error_type_private_size, |
| error_type_init, |
| error_type_copy, |
| error_type_clear); |
| return error_quark; |
| } |
| |
| /** |
| * g_error_domain_register: |
| * @error_type_name: string to create a #GQuark from |
| * @error_type_private_size: size of the private error data in bytes |
| * @error_type_init: function initializing fields of the private error data |
| * @error_type_copy: function copying fields of the private error data |
| * @error_type_clear: function freeing fields of the private error data |
| * |
| * This function registers an extended #GError domain. |
| * @error_type_name will be duplicated. Otherwise does the same as |
| * g_error_domain_register_static(). |
| * |
| * Returns: #GQuark representing the error domain |
| * Since: 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) |
| { |
| GQuark error_quark; |
| |
| g_return_val_if_fail (error_type_name != NULL, 0); |
| g_return_val_if_fail (error_type_private_size > 0, 0); |
| g_return_val_if_fail (error_type_init != NULL, 0); |
| g_return_val_if_fail (error_type_copy != NULL, 0); |
| g_return_val_if_fail (error_type_clear != NULL, 0); |
| |
| error_quark = g_quark_from_string (error_type_name); |
| error_domain_register (error_quark, |
| error_type_private_size, |
| error_type_init, |
| error_type_copy, |
| error_type_clear); |
| return error_quark; |
| } |
| |
| static GError * |
| g_error_allocate (GQuark domain, ErrorDomainInfo *out_info) |
| { |
| guint8 *allocated; |
| GError *error; |
| ErrorDomainInfo *info; |
| gsize private_size; |
| |
| g_rw_lock_reader_lock (&error_domain_global); |
| info = error_domain_lookup (domain); |
| if (info != NULL) |
| { |
| if (out_info != NULL) |
| *out_info = *info; |
| private_size = info->private_size; |
| g_rw_lock_reader_unlock (&error_domain_global); |
| } |
| else |
| { |
| g_rw_lock_reader_unlock (&error_domain_global); |
| if (out_info != NULL) |
| memset (out_info, 0, sizeof (*out_info)); |
| private_size = 0; |
| } |
| /* See comments in g_type_create_instance in gtype.c to see what |
| * this magic is about. |
| */ |
| #ifdef ENABLE_VALGRIND |
| if (private_size > 0 && RUNNING_ON_VALGRIND) |
| { |
| private_size += ALIGN_STRUCT (1); |
| allocated = g_slice_alloc0 (private_size + sizeof (GError) + sizeof (gpointer)); |
| *(gpointer *) (allocated + private_size + sizeof (GError)) = allocated + ALIGN_STRUCT (1); |
| VALGRIND_MALLOCLIKE_BLOCK (allocated + private_size, sizeof (GError) + sizeof (gpointer), 0, TRUE); |
| VALGRIND_MALLOCLIKE_BLOCK (allocated + ALIGN_STRUCT (1), private_size - ALIGN_STRUCT (1), 0, TRUE); |
| } |
| else |
| #endif |
| allocated = g_slice_alloc0 (private_size + sizeof (GError)); |
| |
| error = (GError *) (allocated + private_size); |
| return error; |
| } |
| |
| /* This function takes ownership of @message. */ |
| static GError * |
| g_error_new_steal (GQuark domain, |
| gint code, |
| gchar *message, |
| ErrorDomainInfo *out_info) |
| { |
| ErrorDomainInfo info; |
| GError *error = g_error_allocate (domain, &info); |
| |
| error->domain = domain; |
| error->code = code; |
| error->message = message; |
| |
| if (info.init != NULL) |
| info.init (error); |
| if (out_info != NULL) |
| *out_info = info; |
| |
| return error; |
| } |
| |
| /** |
| * 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) |
| { |
| /* Historically, GError allowed this (although it was never meant to work), |
| * and it has significant use in the wild, which g_return_val_if_fail |
| * would break. It should maybe g_return_val_if_fail in GLib 4. |
| * (GNOME#660371, GNOME#560482) |
| */ |
| g_warn_if_fail (domain != 0); |
| g_warn_if_fail (format != NULL); |
| |
| return g_error_new_steal (domain, code, g_strdup_vprintf (format, args), NULL); |
| } |
| |
| /** |
| * g_error_new: |
| * @domain: error domain |
| * @code: error code |
| * @format: printf()-style format for error message |
| * @...: parameters for message format |
| * |
| * Creates a new #GError with the given @domain and @code, |
| * and a message formatted with @format. |
| * |
| * Returns: 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. |
| * |
| * Returns: a new #GError |
| **/ |
| GError* |
| g_error_new_literal (GQuark domain, |
| gint code, |
| const gchar *message) |
| { |
| g_return_val_if_fail (message != NULL, NULL); |
| g_return_val_if_fail (domain != 0, NULL); |
| |
| return g_error_new_steal (domain, code, g_strdup (message), NULL); |
| } |
| |
| /** |
| * g_error_free: |
| * @error: a #GError |
| * |
| * Frees a #GError and associated resources. |
| */ |
| void |
| g_error_free (GError *error) |
| { |
| gsize private_size; |
| ErrorDomainInfo *info; |
| guint8 *allocated; |
| |
| g_return_if_fail (error != NULL); |
| |
| g_rw_lock_reader_lock (&error_domain_global); |
| info = error_domain_lookup (error->domain); |
| if (info != NULL) |
| { |
| GErrorClearFunc clear = info->clear; |
| |
| private_size = info->private_size; |
| g_rw_lock_reader_unlock (&error_domain_global); |
| clear (error); |
| } |
| else |
| { |
| g_rw_lock_reader_unlock (&error_domain_global); |
| private_size = 0; |
| } |
| |
| g_free (error->message); |
| allocated = ((guint8 *) error) - private_size; |
| /* See comments in g_type_free_instance in gtype.c to see what this |
| * magic is about. |
| */ |
| #ifdef ENABLE_VALGRIND |
| if (private_size > 0 && RUNNING_ON_VALGRIND) |
| { |
| private_size += ALIGN_STRUCT (1); |
| allocated -= ALIGN_STRUCT (1); |
| *(gpointer *) (allocated + private_size + sizeof (GError)) = NULL; |
| g_slice_free1 (private_size + sizeof (GError) + sizeof (gpointer), allocated); |
| VALGRIND_FREELIKE_BLOCK (allocated + ALIGN_STRUCT (1), 0); |
| VALGRIND_FREELIKE_BLOCK (error, 0); |
| } |
| else |
| #endif |
| g_slice_free1 (private_size + sizeof (GError), allocated); |
| } |
| |
| /** |
| * g_error_copy: |
| * @error: a #GError |
| * |
| * Makes a copy of @error. |
| * |
| * Returns: a new #GError |
| */ |
| GError* |
| g_error_copy (const GError *error) |
| { |
| GError *copy; |
| ErrorDomainInfo info; |
| |
| g_return_val_if_fail (error != NULL, NULL); |
| /* See g_error_new_valist for why these don't return */ |
| g_warn_if_fail (error->domain != 0); |
| g_warn_if_fail (error->message != NULL); |
| |
| copy = g_error_new_steal (error->domain, |
| error->code, |
| g_strdup (error->message), |
| &info); |
| if (info.copy != NULL) |
| info.copy (error, copy); |
| |
| return copy; |
| } |
| |
| /** |
| * g_error_matches: |
| * @error: (nullable): a #GError |
| * @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. |
| * |
| * If @domain contains a `FAILED` (or otherwise generic) error code, |
| * you should generally not check for it explicitly, but should |
| * instead treat any not-explicitly-recognized error code as being |
| * equivalent to the `FAILED` code. This way, if the domain is |
| * extended in the future to provide a more specific error code for |
| * a certain case, your code will still work. |
| * |
| * Returns: 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: (out callee-allocates) (optional): a return location for a #GError |
| * @domain: error domain |
| * @code: error code |
| * @format: printf()-style format |
| * @...: 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_error_free (new); |
| } |
| } |
| |
| /** |
| * g_set_error_literal: |
| * @err: (out callee-allocates) (optional): a return location for a #GError |
| * @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) |
| { |
| if (err == NULL) |
| return; |
| |
| if (*err == NULL) |
| *err = g_error_new_literal (domain, code, message); |
| else |
| g_warning (ERROR_OVERWRITTEN_WARNING, message); |
| } |
| |
| /** |
| * g_propagate_error: |
| * @dest: (out callee-allocates) (optional) (nullable): error return location |
| * @src: (transfer full): 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. |
| * |
| * @src must be non-%NULL. |
| * |
| * Note that @src is no longer valid after this call. If you want |
| * to keep using the same GError*, you need to set it to %NULL |
| * after calling this function on it. |
| */ |
| void |
| g_propagate_error (GError **dest, |
| GError *src) |
| { |
| g_return_if_fail (src != NULL); |
| |
| if (dest == NULL) |
| { |
| g_error_free (src); |
| return; |
| } |
| else |
| { |
| if (*dest != NULL) |
| { |
| g_warning (ERROR_OVERWRITTEN_WARNING, src->message); |
| g_error_free (src); |
| } |
| else |
| *dest = src; |
| } |
| } |
| |
| /** |
| * g_clear_error: |
| * @err: a #GError return location |
| * |
| * If @err or *@err is %NULL, does nothing. Otherwise, |
| * 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; |
| } |
| } |
| |
| G_GNUC_PRINTF(2, 0) |
| 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: (inout) (optional) (nullable): a return location for a #GError |
| * @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. |
| * |
| * 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_prefix_error_literal: |
| * @err: (allow-none): a return location for a #GError, or %NULL |
| * @prefix: string to prefix @err with |
| * |
| * Prefixes @prefix to an existing error message. If @err or *@err is |
| * %NULL (i.e.: no error variable) then do nothing. |
| * |
| * Since: 2.70 |
| */ |
| void |
| g_prefix_error_literal (GError **err, |
| const gchar *prefix) |
| { |
| if (err && *err) |
| { |
| gchar *oldstring; |
| |
| oldstring = (*err)->message; |
| (*err)->message = g_strconcat (prefix, oldstring, NULL); |
| g_free (oldstring); |
| } |
| } |
| |
| /** |
| * 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) |
| { |
| va_list ap; |
| |
| g_assert (*dest != NULL); |
| va_start (ap, format); |
| g_error_add_prefix (&(*dest)->message, format, ap); |
| va_end (ap); |
| } |
| } |