Provided by: libglib2.0-dev-bin_2.58.1-2_amd64 bug

NAME

       gdbus-codegen - D-Bus code and documentation generator

SYNOPSIS

       gdbus-codegen [-h, --help] [--interface-prefix org.project.Prefix]
                     [--generate-c-code OUTFILES] [--c-namespace YourProject]
                     [--c-generate-object-manager] [--c-generate-autocleanup none|objects|all]
                     [--output-directory OUTDIR] [--generate-docbook OUTFILES] [--pragma-once]
                     [--xml-files FILE] [--header] [--body] [--interface-info-header]
                     [--interface-info-body] [--output OUTFILE] [--annotate ELEMENT KEY VALUE]...
                     FILE [FILE...]

DESCRIPTION

       gdbus-codegen is used to generate code and/or documentation for one or more D-Bus
       interfaces.

       gdbus-codegen reads D-Bus Introspection XML[1] from files passed as additional arguments
       on the command line and generates output files. It currently supports generating C source
       code (via --body) or header (via --header) and Docbook XML (via --generate-docbook).
       Alternatively, more restricted C source code and headers can be generated, which just
       contain the interface information (as GDBusInterfaceInfo structures) using
       --interface-info-body and --interface-info-header.

GENERATING C CODE

       When generating C code, a #GInterface -derived type is generated for each D-Bus interface.
       Additionally, for every generated type, FooBar, two concrete instantiable types,
       FooBarProxy and FooBarSkeleton, implementing said interface are also generated. The former
       is derived from #GDBusProxy and intended for use on the client side while the latter is
       derived from the #GDBusInterfaceSkeleton type making it easy to export on a
       #GDBusConnection either directly or via a #GDBusObjectManagerServer instance.

       For C code generation either --body that generates source code, --header that generates
       headers, --interface-info-body that generates interface information source code, or
       --interface-info-header that generates interface information headers, can be used. These
       options must be used along with --output, which is used to specify the file to output to.

       Both files can be generated at the same time by using --generate-c-code, but this option
       is deprecated. In this case --output cannot be used due to the generation of multiple
       files. Instead pass --output-directory to specify the directory to put the output files
       in. By default the current directory will be used.

       The name of each generated C type is derived from the D-Bus interface name stripped with
       the prefix given with --interface-prefix and with the dots removed and initial characters
       capitalized. For example, for the D-Bus interface com.acme.Coyote the name used is
       ComAcmeCoyote. For the D-Bus interface org.project.Bar.Frobnicator with --interface-prefix
       org.project., the name used is BarFrobnicator.

       For methods, signals and properties, if not specified, the name defaults to the name of
       the method, signal or property.

       Two forms of the name are used - the CamelCase form and the lower-case form. The CamelCase
       form is used for the #GType and struct name, while lower-case form is used in function
       names. The lower-case form is calculated by converting from CamelCase to lower-case and
       inserting underscores at word boundaries (using certain heuristics).

       If the value given by the org.gtk.GDBus.C.Name annotation or the --c-namespace option
       contains an underscore (sometimes called Ugly_Case), then the camel-case name is derived
       by removing all underscores, and the lower-case name is derived by lower-casing the
       string. This is useful in some situations where abbreviations are used. For example, if
       the annotation is used on the interface net.MyCorp.MyApp.iSCSITarget with the value
       iSCSI_Target the CamelCase form is iSCSITarget while the lower-case form is iscsi_target.
       If the annotation is used on the method EjectTheiPod with the value Eject_The_iPod, the
       lower-case form is eject_the_ipod.

GENERATING DOCBOOK DOCUMENTATION

       Each generated Docbook XML file (see the --generate-docbook option for details) is a
       RefEntry[2] article describing the D-Bus interface.

OPTIONS

       The following options are supported:

       -h, --help
           Show help and exit.

       --xml-files FILE
           This option is deprecated; use positional arguments instead. The D-Bus introspection
           XML file.

       --interface-prefix org.project.Prefix.
           A prefix to strip from all D-Bus interface names when calculating the typename for the
           C binding and the Docbook sortas attribute[3].

       --generate-docbook OUTFILES
           Generate Docbook Documentation for each D-Bus interface and put it in
           OUTFILES-NAME.xml where NAME is a place-holder for the interface name, e.g.
           net.Corp.FooBar and so on.

           Pass --output-directory to specify the directory to put the output files in. By
           default the current directory will be used.

       --generate-c-code OUTFILES
           Generate C code for all D-Bus interfaces and put it in OUTFILES.c and OUTFILES.h
           including any sub-directories. If you want the files to be output in a different
           location use --output-directory as OUTFILES.h including sub-directories will be
           referenced from OUTFILES.c.

           The full paths would then be $(OUTDIR)/$(dirname $OUTFILES)/$(basename
           $OUTFILES).{c,h}.

       --c-namespace YourProject
           The namespace to use for generated C code. This is expected to be in CamelCase[4] or
           Ugly_Case (see above).

       --pragma-once
           If this option is passed, the #pragma once[5] preprocessor directive is used instead
           of include guards.

       --c-generate-object-manager
           If this option is passed, suitable #GDBusObject, #GDBusObjectProxy,
           #GDBusObjectSkeleton and #GDBusObjectManagerClient subclasses are generated.

       --c-generate-autocleanup none|objects|all
           This option influences what types autocleanup functions are generated for. 'none'
           means to not generate any autocleanup functions. 'objects' means to generate them for
           object types, and 'all' means to generate them for object types and interfaces. The
           default is 'objects' due to a corner case in backwards compatibility with a few
           projects, but you should likely switch your project to use 'all'. This option was
           added in GLib 2.50.

       --output-directory OUTDIR
           Directory to output generated source to. Equivalent to changing directory before
           generation.

           This option cannot be used with --body, --header, --interface-info-body or
           --interface-info-header; and --output must be used.

       --header
           If this option is passed, it will generate the header code and write it to the disk by
           using the path and file name provided by --output.

           Using --generate-c-code, --generate-docbook or --output-directory are not allowed to
           be used along with --header and --body options, because these options are used to
           generate only one file.

       --body
           If this option is passed, it will generate the source code and write it to the disk by
           using the path and file name provided by --output.

           Using --generate-c-code, --generate-docbook or --output-directory are not allowed to
           be used along with --header and --body options, because these options are used to
           generate only one file.

       --interface-info-header
           If this option is passed, it will generate the header code for the GDBusInterfaceInfo
           structures only and will write it to the disk by using the path and file name provided
           by --output.

           Using --generate-c-code, --generate-docbook or --output-directory are not allowed to
           be used along with the --interface-info-header and --interface-info-body options,
           because these options are used to generate only one file.

       --interface-info-body
           If this option is passed, it will generate the source code for the GDBusInterfaceInfo
           structures only and will write it to the disk by using the path and file name provided
           by --output.

           Using --generate-c-code, --generate-docbook or --output-directory are not allowed to
           be used along with the --interface-info-header and --interface-info-body options,
           because these options are used to generate only one file.

       --output OUTFILE
           The full path where the header (--header, --interface-info-header) or the source code
           (--body, --interface-info-body) will be written, using the path and filename provided
           by --output. The full path could be something like $($OUTFILE).{c,h}.

           Using --generate-c-code, --generate-docbook or --output-directory is not allowed along
           with --output, because the latter is used to generate only one file.

       --annotate ELEMENT KEY VALUE
           Used to inject D-Bus annotations into the given XML files. It can be used with
           interfaces, methods, signals, properties and arguments in the following way:

               gdbus-codegen --c-namespace MyApp                           \
                 --generate-c-code myapp-generated                         \
                 --annotate "org.project.InterfaceName"                    \
                   org.gtk.GDBus.C.Name MyFrobnicator                      \
                 --annotate "org.project.InterfaceName:Property"           \
                   bar bat                                                 \
                 --annotate "org.project.InterfaceName.Method()"           \
                   org.freedesktop.DBus.Deprecated true                    \
                 --annotate "org.project.InterfaceName.Method()[arg_name]" \
                   snake hiss                                              \
                 --annotate "org.project.InterfaceName::Signal"            \
                   cat meow                                                \
                 --annotate "org.project.InterfaceName::Signal[arg_name]"  \
                   dog wuff                                                \
                 myapp-dbus-interfaces.xml
           Any UTF-8 string can be used for KEY and VALUE.

SUPPORTED D-BUS ANNOTATIONS

       The following D-Bus annotations are supported by gdbus-codegen:

       org.freedesktop.DBus.Deprecated
           Can be used on any <interface>, <method>, <signal> and <property> element to specify
           that the element is deprecated if its value is true. Note that this annotation is
           defined in the D-Bus specification[1] and can only assume the values true and false.
           In particular, you cannot specify the version that the element was deprecated in nor
           any helpful deprecation message. Such information should be added to the element
           documentation instead.

           When generating C code, this annotation is used to add #G_GNUC_DEPRECATED to generated
           functions for the element.

           When generating Docbook XML, a deprecation warning will appear along the documentation
           for the element.

       org.gtk.GDBus.Since
           Can be used on any <interface>, <method>, <signal> and <property> element to specify
           the version (any free-form string but compared using a version-aware sort function)
           the element appeared in.

           When generating C code, this field is used to ensure function pointer order for
           preserving ABI/API, see the section called “STABILITY GUARANTEES”.

           When generating Docbook XML, the value of this tag appears in the documentation.

       org.gtk.GDBus.DocString
           A string with Docbook content for documentation. This annotation can be used on
           <interface>, <method>, <signal>, <property> and <arg> elements.

       org.gtk.GDBus.DocString.Short
           A string with Docbook content for short/brief documentation. This annotation can only
           be used on <interface> elements.

       org.gtk.GDBus.C.Name
           Can be used on any <interface>, <method>, <signal> and <property> element to specify
           the name to use when generating C code. The value is expected to be in CamelCase[4] or
           Ugly_Case (see above).

       org.gtk.GDBus.C.ForceGVariant
           If set to a non-empty string, a #GVariant instance will be used instead of the natural
           C type. This annotation can be used on any <arg> and <property> element.

       org.gtk.GDBus.C.UnixFD
           If set to a non-empty string, the generated code will include parameters to exchange
           file descriptors using the #GUnixFDList type. This annotation can be used on <method>
           elements.

       As an easier alternative to using the org.gtk.GDBus.DocString annotation, note that parser
       used by gdbus-codegen parses XML comments in a way similar to gtk-doc[6]:

       Note that @since can be used in any inline documentation bit (e.g. for interfaces,
       methods, signals and properties) to set the org.gtk.GDBus.Since annotation. For the
       org.gtk.GDBus.DocString annotation (and inline comments), note that substrings of the form
       #net.Corp.Bar, net.Corp.Bar.FooMethod(), #net.Corp.Bar::BarSignal and
       #net.Corp.InlineDocs:BazProperty are all expanded to links to the respective interface,
       method, signal and property. Additionally, substrings starting with @ and % characters are
       rendered as parameter[7] and constant[8] respectively.

       If both XML comments and org.gtk.GDBus.DocString or org.gtk.GDBus.DocString.Short
       annotations are present, the latter wins.

EXAMPLE

       Consider the following D-Bus Introspection XML.

           <node>
             <interface name="net.Corp.MyApp.Frobber">
               <method name="HelloWorld">
                 <arg name="greeting" direction="in" type="s"/>
                 <arg name="response" direction="out" type="s"/>
               </method>

               <signal name="Notification">
                 <arg name="icon_blob" type="ay"/>
                 <arg name="height" type="i"/>
                 <arg name="messages" type="as"/>
               </signal>

               <property name="Verbose" type="b" access="readwrite"/>
             </interface>
           </node>

       If gdbus-codegen is used on this file like this:

           gdbus-codegen --generate-c-code myapp-generated       \
                         --c-namespace MyApp                     \
                         --interface-prefix net.corp.MyApp.      \
                         net.Corp.MyApp.Frobber.xml

       two files called myapp-generated.[ch] are generated. The files provide an abstract
       #GTypeInterface -derived type called MyAppFrobber as well as two instantiable types with
       the same name but suffixed with Proxy and Skeleton. The generated file, roughly, contains
       the following facilities:

           /* GType macros for the three generated types */
           #define MY_APP_TYPE_FROBBER (my_app_frobber_get_type ())
           #define MY_APP_TYPE_FROBBER_SKELETON (my_app_frobber_skeleton_get_type ())
           #define MY_APP_TYPE_FROBBER_PROXY (my_app_frobber_proxy_get_type ())

           typedef struct _MyAppFrobber MyAppFrobber; /* Dummy typedef */

           typedef struct
           {
             GTypeInterface parent_iface;

             /* Signal handler for the ::notification signal */
             void (*notification) (MyAppFrobber *proxy,
                                   GVariant *icon_blob,
                                   gint height,
                                   const gchar* const *messages);

             /* Signal handler for the ::handle-hello-world signal */
             gboolean (*handle_hello_world) (MyAppFrobber *proxy,
                                             GDBusMethodInvocation *invocation,
                                             const gchar *greeting);
           } MyAppFrobberIface;

           /* Asynchronously calls HelloWorld() */
           void
           my_app_frobber_call_hello_world (MyAppFrobber *proxy,
                                            const gchar *greeting,
                                            GCancellable *cancellable,
                                            GAsyncReadyCallback callback,
                                            gpointer user_data);
           gboolean
           my_app_frobber_call_hello_world_finish (MyAppFrobber *proxy,
                                                   gchar **out_response,
                                                   GAsyncResult *res,
                                                   GError **error);

           /* Synchronously calls HelloWorld(). Blocks calling thread. */
           gboolean
           my_app_frobber_call_hello_world_sync (MyAppFrobber *proxy,
                                                 const gchar *greeting,
                                                 gchar **out_response,
                                                 GCancellable *cancellable,
                                                 GError **error);

           /* Completes handling the HelloWorld() method call */
           void
           my_app_frobber_complete_hello_world (MyAppFrobber *object,
                                                GDBusMethodInvocation *invocation,
                                                const gchar *response);

           /* Emits the ::notification signal / Notification() D-Bus signal */
           void
           my_app_frobber_emit_notification (MyAppFrobber *object,
                                             GVariant *icon_blob,
                                             gint height,
                                             const gchar* const *messages);

           /* Gets the :verbose GObject property / Verbose D-Bus property.
            * Does no blocking I/O.
            */
           gboolean my_app_frobber_get_verbose (MyAppFrobber *object);

           /* Sets the :verbose GObject property / Verbose D-Bus property.
            * Does no blocking I/O.
            */
           void my_app_frobber_set_verbose (MyAppFrobber *object,
                                            gboolean      value);

           /* Gets the interface info */
           GDBusInterfaceInfo *my_app_frobber_interface_info (void);

           /* Creates a new skeleton object, ready to be exported */
           MyAppFrobber *my_app_frobber_skeleton_new (void);

           /* Client-side proxy constructors.
            *
            * Additionally, _new_for_bus(), _new_for_bus_finish() and
            * _new_for_bus_sync() proxy constructors are also generated.
            */
           void
           my_app_frobber_proxy_new        (GDBusConnection     *connection,
                                            GDBusProxyFlags      flags,
                                            const gchar         *name,
                                            const gchar         *object_path,
                                            GCancellable        *cancellable,
                                            GAsyncReadyCallback  callback,
                                            gpointer             user_data);
           MyAppFrobber *
           my_app_frobber_proxy_new_finish (GAsyncResult        *res,
                                            GError             **error);
           MyAppFrobber *
           my_app_frobber_proxy_new_sync   (GDBusConnection     *connection,
                                            GDBusProxyFlags      flags,
                                            const gchar         *name,
                                            const gchar         *object_path,
                                            GCancellable        *cancellable,
                                            GError             **error);

       Thus, for every D-Bus method, there will be three C functions for calling the method, one
       #GObject signal for handling an incoming call and one C function for completing an
       incoming call. For every D-Bus signal, there's one #GObject signal and one C function for
       emitting it. For every D-Bus property, two C functions are generated (one setter, one
       getter) and one #GObject property. The following table summarizes the generated facilities
       and where they are applicable:

       ┌─────────────────────┬─────────────────────────┬──────────────────────────────┐
       │                     │ ClientServer                       │
       ├─────────────────────┼─────────────────────────┼──────────────────────────────┤
       │Types                │ Use MyAppFrobberProxy   │ Any type implementing        │
       │                     │                         │ the MyAppFrobber             │
       │                     │                         │ interface                    │
       ├─────────────────────┼─────────────────────────┼──────────────────────────────┤
       │Methods              │ Use m_a_f_hello_world() │ Receive via the              │
       │                     │ to call.                │ handle_hello_world()         │
       │                     │                         │ signal handler. Complete     │
       │                     │                         │ the call with                │
       │                     │                         │ m_a_f_complete_hello_world() │
       ├─────────────────────┼─────────────────────────┼──────────────────────────────┤
       │Signals              │ Connect to the          │ Use                          │
       │                     │ ::notification GObject  │ m_a_f_emit_notification() to │
       │                     │ signal.                 │ emit signal.                 │
       ├─────────────────────┼─────────────────────────┼──────────────────────────────┤
       │Properties (Reading) │ Use m_a_f_get_verbose() │ Implement #GObject's         │
       │                     │ or :verbose.            │ get_property() vfunc.        │
       ├─────────────────────┼─────────────────────────┼──────────────────────────────┤
       │Properties (writing) │ Use m_a_f_set_verbose() │ Implement #GObject's         │
       │                     │ or :verbose.            │ set_property() vfunc.        │
       └─────────────────────┴─────────────────────────┴──────────────────────────────┘

   Client-side usage
       You can use the generated proxy type with the generated constructors:

               MyAppFrobber *proxy;
               GError *error;

               error = NULL;
               proxy = my_app_frobber_proxy_new_for_bus_sync (
                           G_BUS_TYPE_SESSION,
                           G_DBUS_PROXY_FLAGS_NONE,
                           "net.Corp.MyApp",              /* bus name */
                           "/net/Corp/MyApp/SomeFrobber", /* object */
                           NULL,                          /* GCancellable* */
                           &error);
               /* do stuff with proxy */
               g_object_unref (proxy);

       Instead of using the generic #GDBusProxy facilities, one can use the generated methods
       such as my_app_frobber_call_hello_world() to invoke the
       net.Corp.MyApp.Frobber.HelloWorld() D-Bus method, connect to the ::notification GObject
       signal to receive the net.Corp.MyApp.Frobber::Notication D-Bus signal and get/set the
       net.Corp.MyApp.Frobber:Verbose D-Bus Property using either the GObject property :verbose
       or the my_app_get_verbose() and my_app_set_verbose() methods. Use the standard
       #GObject::notify signal to listen to property changes.

       Note that all property access is via #GDBusProxy 's property cache so no I/O is ever done
       when reading properties. Also note that setting a property will cause the
       org.freedesktop.DBus.Properties.Set[9] method to be called on the remote object. This
       call, however, is asynchronous so setting a property won't block. Further, the change is
       delayed and no error checking is possible.

   Server-side usage
       The generated MyAppFrobber interface is designed so it is easy to implement it in a
       #GObject subclass. For example, to handle HelloWorld() method invocations, set the vfunc
       for handle_hello_hello_world() in the MyAppFrobberIface structure. Similary, to handle the
       net.Corp.MyApp.Frobber:Verbose property override the :verbose #GObject property from the
       subclass. To emit a signal, use e.g.  my_app_emit_signal() or g_signal_emit_by_name().

       Instead of subclassing, it is often easier to use the generated MyAppFrobberSkeleton
       subclass. To handle incoming method calls, use g_signal_connect() with the ::handle-*
       signals and instead of overriding #GObject 's get_property() and set_property() vfuncs,
       use g_object_get() and g_object_set() or the generated property getters and setters (the
       generated class has an internal property bag implementation).

           static gboolean
           on_handle_hello_world (MyAppFrobber           *interface,
                                  GDBusMethodInvocation  *invocation,
                                  const gchar            *greeting,
                                  gpointer                user_data)
           {
             if (g_strcmp0 (greeting, "Boo") != 0)
               {
                 gchar *response;
                 response = g_strdup_printf ("Word! You said `%s'.", greeting);
                 my_app_complete_hello_world (interface, invocation, response);
                 g_free (response);
               }
             else
               {
                 g_dbus_method_invocation_return_error (invocation,
                            MY_APP_ERROR,
                            MY_APP_ERROR_NO_WHINING,
                            "Hey, %s, there will be no whining!",
                            g_dbus_method_invocation_get_sender (invocation));
               }
             return TRUE;
           }

             [...]

             interface = my_app_frobber_skeleton_new ();
             my_app_frobber_set_verbose (interface, TRUE);

             g_signal_connect (interface,
                               "handle-hello-world",
                               G_CALLBACK (on_handle_hello_world),
                               some_user_data);

             [...]

             error = NULL;
             if (!g_dbus_interface_skeleton_export (G_DBUS_INTERFACE_SKELETON (interface),
                                                    connection,
                                                    "/path/of/dbus_object",
                                                    &error))
               {
                 /* handle error */
               }

       To facilitate atomic changesets (multiple properties changing at the same time),
       #GObject::notify signals are queued up when received. The queue is drained in an idle
       handler (which is called from the thread-default main loop of the thread where the
       skeleton object was contructed) and will cause emissions of the
       org.freedesktop.DBus.Properties::PropertiesChanged[9] signal with all the properties that
       have changed. Use g_dbus_interface_skeleton_flush() or g_dbus_object_skeleton_flush() to
       empty the queue immediately. Use g_object_freeze_notify() and g_object_thaw_notify() for
       atomic changesets if on a different thread.

C TYPE MAPPING

       Scalar types (type-strings 'b', 'y', 'n', 'q', 'i', 'u', 'x', 't' and 'd') ), strings
       (type-strings 's', 'ay', 'o' and 'g') and arrays of string (type-strings 'as', 'ao' and
       'aay') are mapped to the natural types, e.g. #gboolean, #gdouble, #gint, gchar*, gchar**
       and so on. Everything else is mapped to the #GVariant type.

       This automatic mapping can be turned off by using the annotation
       org.gtk.GDBus.C.ForceGVariant - if used then a #GVariant is always exchanged instead of
       the corresponding native C type. This annotation may be convenient to use when using
       bytestrings (type-string 'ay') for data that could have embedded NUL bytes.

STABILITY GUARANTEES

       The generated C functions are guaranteed to not change their ABI that is, if a method,
       signal or property does not change its signature in the introspection XML, the generated C
       functions will not change its C ABI either. The ABI of the generated instance and class
       structures will be preserved as well.

       The ABI of the generated #GType s will be preserved only if the org.gtk.GDBus.Since
       annotation is used judiciously — this is because the VTable for the #GInterface relies on
       functions pointers for signal handlers. Specifically, if a D-Bus method, property or
       signal or is added to a D-Bus interface, then ABI of the generated #GInterface type is
       preserved if, and only if, each added method, property signal is annotated with they
       org.gtk.GDBus.Since annotation using a greater version number than previous versions.

       The generated C code currently happens to be annotated with gtk-doc[6] / GObject
       Introspection[10] comments / annotations. The layout and contents might change in the
       future so no guarantees about e.g.  SECTION usage etc. is given.

       While the generated Docbook for D-Bus interfaces isn't expected to change, no guarantees
       are given at this point.

       It is important to note that the generated code should not be checked into revision
       control systems, nor it should be included in distributed source archives.

BUGS

       Please send bug reports to either the distribution bug tracker or the upstream bug tracker
       at https://gitlab.gnome.org/GNOME/glib/issues/new.

SEE ALSO

       gdbus(1)

NOTES

        1. D-Bus Introspection XML
           http://dbus.freedesktop.org/doc/dbus-specification.html#introspection-format

        2. RefEntry
           http://www.docbook.org/tdg/en/html/refentry.html

        3. sortas attribute
           http://www.docbook.org/tdg/en/html/primary.html

        4. CamelCase
           http://en.wikipedia.org/wiki/CamelCase

        5. #pragma once
           https://en.wikipedia.org/wiki/Pragma_once

        6. gtk-doc
           http://www.gtk.org/gtk-doc/

        7. parameter
           http://www.docbook.org/tdg/en/html/parameter.html

        8. constant
           http://www.docbook.org/tdg/en/html/constant.html

        9. org.freedesktop.DBus.Properties.Set
           http://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-properties

       10. GObject Introspection
           https://wiki.gnome.org/Projects/GObjectIntrospection