Merge from emacs--devo--0

Revision: emacs@sv.gnu.org/emacs--unicode--0--patch-294

1 files changed, 817 insertions, 0 deletions

diff --git a/src/dbusbind.c b/src/dbusbind.c
new file mode 100644
index 00000000000..07fc24243d7
--- /dev/null
+++ b/src/dbusbind.c
@@ -0,0 +1,817 @@
+/* Elisp bindings for D-Bus.
+   Copyright (C) 2007 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GNU Emacs 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+#include "config.h"
+
+#ifdef HAVE_DBUS
+#include <stdlib.h>
+#include <dbus/dbus.h>
+#include "lisp.h"
+#include "frame.h"
+#include "termhooks.h"
+#include "keyboard.h"
+
+
+/* Subroutines.  */
+Lisp_Object Qdbus_get_unique_name;
+Lisp_Object Qdbus_call_method;
+Lisp_Object Qdbus_send_signal;
+Lisp_Object Qdbus_register_signal;
+Lisp_Object Qdbus_unregister_signal;
+
+/* D-Bus error symbol.  */
+Lisp_Object Qdbus_error;
+
+/* Lisp symbols of the system and session buses.  */
+Lisp_Object QCdbus_system_bus, QCdbus_session_bus;
+
+/* Hash table which keeps function definitions.  */
+Lisp_Object Vdbus_registered_functions_table;
+
+/* Whether to debug D-Bus.  */
+Lisp_Object Vdbus_debug;
+
+
+/* We use "xd_" and "XD_" as prefix for all internal symbols, because
+   we don't want to poison other namespaces with "dbus_".  */
+
+/* Raise a Lisp error from a D-Bus error.  */
+#define XD_ERROR(error)                                                 \
+  {                                                                     \
+    char s[1024];                                                       \
+    strcpy (s, error.message);                                          \
+    dbus_error_free (&error);                                           \
+    /* Remove the trailing newline.  */                                 \
+    if (strchr (s, '\n') != NULL)                                       \
+      s[strlen (s) - 1] = '\0';                                         \
+    xsignal1 (Qdbus_error, build_string (s));                           \
+  }
+
+/* Macros for debugging.  In order to enable them, build with
+   "make MYCPPFLAGS='-DDBUS_DEBUG'".  */
+#ifdef DBUS_DEBUG
+#define XD_DEBUG_MESSAGE(...)           \
+  {                                     \
+    char s[1024];                       \
+    sprintf (s, __VA_ARGS__);           \
+    printf ("%s: %s\n", __func__, s);   \
+    message ("%s: %s", __func__, s);    \
+  }
+#define XD_DEBUG_VALID_LISP_OBJECT_P(object)                            \
+  if (!valid_lisp_object_p (object))                                    \
+    {                                                                   \
+      XD_DEBUG_MESSAGE ("%s Assertion failure", __LINE__);              \
+      xsignal1 (Qdbus_error, build_string ("Assertion failure"));       \
+    }
+
+#else /* !DBUS_DEBUG */
+#define XD_DEBUG_MESSAGE(...)           \
+  if (!NILP (Vdbus_debug))              \
+    {                                   \
+      char s[1024];                     \
+      sprintf (s, __VA_ARGS__);         \
+      message ("%s: %s", __func__, s);  \
+    }
+#define XD_DEBUG_VALID_LISP_OBJECT_P(object)
+#endif
+
+/* Determine the DBusType of a given Lisp object.  It is used to
+   convert Lisp objects, being arguments of `dbus-call-method' or
+   `dbus-send-signal', into corresponding C values appended as
+   arguments to a D-Bus message.  */
+#define XD_LISP_OBJECT_TO_DBUS_TYPE(object)                             \
+  (EQ (object, Qt) || EQ (object, Qnil)) ? DBUS_TYPE_BOOLEAN :          \
+  (NATNUMP (object)) ? DBUS_TYPE_UINT32 :                               \
+  (INTEGERP (object)) ? DBUS_TYPE_INT32 :                               \
+  (FLOATP (object)) ? DBUS_TYPE_DOUBLE :                                \
+  (STRINGP (object)) ? DBUS_TYPE_STRING :                               \
+  DBUS_TYPE_INVALID
+
+/* Extract C value from Lisp OBJECT.  DTYPE must be a valid DBusType,
+   as detected by XD_LISP_OBJECT_TO_DBUS_TYPE.  Compound types are not
+   supported (yet).  It is used to convert Lisp objects, being
+   arguments of `dbus-call-method' or `dbus-send-signal', into
+   corresponding C values appended as arguments to a D-Bus
+   message.  */
+char *
+xd_retrieve_value (dtype, object)
+     uint dtype;
+     Lisp_Object object;
+{
+
+  XD_DEBUG_VALID_LISP_OBJECT_P (object);
+  switch (dtype)
+    {
+    case DBUS_TYPE_BOOLEAN:
+      XD_DEBUG_MESSAGE ("%d %s", dtype, (NILP (object)) ? "false" : "true");
+      return (NILP (object)) ? (char *) FALSE : (char *) TRUE;
+    case DBUS_TYPE_UINT32:
+      XD_DEBUG_MESSAGE ("%d %d", dtype, XUINT (object));
+      return (char *) XUINT (object);
+    case DBUS_TYPE_INT32:
+      XD_DEBUG_MESSAGE ("%d %d", dtype, XINT (object));
+      return (char *) XINT (object);
+    case DBUS_TYPE_DOUBLE:
+      XD_DEBUG_MESSAGE ("%d %d", dtype, XFLOAT (object));
+      return (char *) XFLOAT (object);
+    case DBUS_TYPE_STRING:
+      XD_DEBUG_MESSAGE ("%d %s", dtype, SDATA (object));
+      return SDATA (object);
+    default:
+      XD_DEBUG_MESSAGE ("DBus-Type %d not supported", dtype);
+      return NULL;
+    }
+}
+
+/* Retrieve C value from a DBusMessageIter structure ITER, and return
+   a converted Lisp object.  The type DTYPE of the argument of the
+   D-Bus message must be a valid DBusType.  Compound D-Bus types are
+   partly supported; they result always in a Lisp list.  */
+Lisp_Object
+xd_retrieve_arg (dtype, iter)
+     uint dtype;
+     DBusMessageIter *iter;
+{
+
+  switch (dtype)
+    {
+    case DBUS_TYPE_BOOLEAN:
+      {
+        dbus_bool_t val;
+        dbus_message_iter_get_basic (iter, &val);
+        XD_DEBUG_MESSAGE ("%d %s", dtype, (val == FALSE) ? "false" : "true");
+        return (val == FALSE) ? Qnil : Qt;
+      }
+    case DBUS_TYPE_INT32:
+    case DBUS_TYPE_UINT32:
+      {
+        dbus_uint32_t val;
+        dbus_message_iter_get_basic (iter, &val);
+        XD_DEBUG_MESSAGE ("%d %d", dtype, val);
+        return make_number (val);
+      }
+    case DBUS_TYPE_STRING:
+    case DBUS_TYPE_OBJECT_PATH:
+      {
+        char *val;
+        dbus_message_iter_get_basic (iter, &val);
+        XD_DEBUG_MESSAGE ("%d %s", dtype, val);
+        return build_string (val);
+      }
+    case DBUS_TYPE_ARRAY:
+    case DBUS_TYPE_VARIANT:
+    case DBUS_TYPE_STRUCT:
+    case DBUS_TYPE_DICT_ENTRY:
+      {
+        Lisp_Object result;
+        struct gcpro gcpro1;
+        result = Qnil;
+        GCPRO1 (result);
+        DBusMessageIter subiter;
+        int subtype;
+        dbus_message_iter_recurse (iter, &subiter);
+        while ((subtype = dbus_message_iter_get_arg_type (&subiter))
+               != DBUS_TYPE_INVALID)
+          {
+            result = Fcons (xd_retrieve_arg (subtype, &subiter), result);
+            dbus_message_iter_next (&subiter);
+          }
+        RETURN_UNGCPRO (Fnreverse (result));
+      }
+    default:
+      XD_DEBUG_MESSAGE ("DBusType %d not supported", dtype);
+      return Qnil;
+    }
+}
+
+
+/* Initialize D-Bus connection.  BUS is a Lisp symbol, either :system
+   or :session.  It tells which D-Bus to be initialized.  */
+DBusConnection *
+xd_initialize (bus)
+     Lisp_Object bus;
+{
+  DBusConnection *connection;
+  DBusError derror;
+
+  /* Parameter check.  */
+  CHECK_SYMBOL (bus);
+  if (!((EQ (bus, QCdbus_system_bus)) || (EQ (bus, QCdbus_session_bus))))
+    xsignal2 (Qdbus_error, build_string ("Wrong bus name"), bus);
+
+  /* Open a connection to the bus.  */
+  dbus_error_init (&derror);
+
+  if (EQ (bus, QCdbus_system_bus))
+    connection = dbus_bus_get (DBUS_BUS_SYSTEM, &derror);
+  else
+    connection = dbus_bus_get (DBUS_BUS_SESSION, &derror);
+
+  if (dbus_error_is_set (&derror))
+    XD_ERROR (derror);
+
+  if (connection == NULL)
+    xsignal2 (Qdbus_error, build_string ("No connection"), bus);
+
+  /* Return the result.  */
+  return connection;
+}
+
+DEFUN ("dbus-get-unique-name", Fdbus_get_unique_name, Sdbus_get_unique_name,
+       1, 1, 0,
+       doc: /* Return the unique name of Emacs registered at D-Bus BUS as string.  */)
+     (bus)
+     Lisp_Object bus;
+{
+  DBusConnection *connection;
+  char name[1024];
+
+  /* Check parameters.  */
+  CHECK_SYMBOL (bus);
+
+  /* Open a connection to the bus.  */
+  connection = xd_initialize (bus);
+
+  /* Request the name.  */
+  strcpy (name, dbus_bus_get_unique_name (connection));
+  if (name == NULL)
+    xsignal1 (Qdbus_error, build_string ("No unique name available"));
+
+  /* Return.  */
+  return build_string (name);
+}
+
+DEFUN ("dbus-call-method", Fdbus_call_method, Sdbus_call_method, 5, MANY, 0,
+       doc: /* Call METHOD on the D-Bus BUS.
+
+BUS is either the symbol `:system' or the symbol `:session'.
+
+SERVICE is the D-Bus service name to be used.  PATH is the D-Bus
+object path SERVICE is registered at.  INTERFACE is an interface
+offered by SERVICE.  It must provide METHOD.
+
+All other arguments ARGS are passed to METHOD as arguments.  They are
+converted into D-Bus types via the following rules:
+
+  t and nil => DBUS_TYPE_BOOLEAN
+  number    => DBUS_TYPE_UINT32
+  integer   => DBUS_TYPE_INT32
+  float     => DBUS_TYPE_DOUBLE
+  string    => DBUS_TYPE_STRING
+
+Other Lisp objects are not supported as input arguments of METHOD.
+
+`dbus-call-method' returns the resulting values of METHOD as a list of
+Lisp objects.  The type conversion happens the other direction as for
+input arguments.  Additionally to the types supported for input
+arguments, the D-Bus compound types DBUS_TYPE_ARRAY, DBUS_TYPE_VARIANT,
+DBUS_TYPE_STRUCT and DBUS_TYPE_DICT_ENTRY are accepted.  All of them
+are converted into a list of Lisp objects which correspond to the
+elements of the D-Bus container.  Example:
+
+\(dbus-call-method
+  :session "GetKeyField" "org.gnome.seahorse"
+  "/org/gnome/seahorse/keys/openpgp" "org.gnome.seahorse.Keys"
+  "openpgp:657984B8C7A966DD" "simple-name")
+
+  => (t ("Philip R. Zimmermann"))
+
+If the result of the METHOD call is just one value, the converted Lisp
+object is returned instead of a list containing this single Lisp object.
+
+\(dbus-call-method
+  :system "GetPropertyString" "org.freedesktop.Hal"
+  "/org/freedesktop/Hal/devices/computer" "org.freedesktop.Hal.Device"
+  "system.kernel.machine")
+
+  => "i686"
+
+usage: (dbus-call-method BUS METHOD SERVICE PATH INTERFACE &rest ARGS)  */)
+     (nargs, args)
+     int nargs;
+     register Lisp_Object *args;
+{
+  Lisp_Object bus, method, service, path, interface;
+  Lisp_Object result;
+  struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
+  DBusConnection *connection;
+  DBusMessage *dmessage;
+  DBusMessage *reply;
+  DBusMessageIter iter;
+  DBusError derror;
+  uint dtype;
+  int i;
+  char *value;
+
+  /* Check parameters.  */
+  bus = args[0];
+  method = args[1];
+  service = args[2];
+  path = args[3];
+  interface = args[4];
+
+  CHECK_SYMBOL (bus);
+  CHECK_STRING (method);
+  CHECK_STRING (service);
+  CHECK_STRING (path);
+  CHECK_STRING (interface);
+  GCPRO5 (bus, method, service, path, interface);
+
+  XD_DEBUG_MESSAGE ("%s %s %s %s",
+                    SDATA (method),
+                    SDATA (service),
+                    SDATA (path),
+                    SDATA (interface));
+
+  /* Open a connection to the bus.  */
+  connection = xd_initialize (bus);
+
+  /* Create the message.  */
+  dmessage = dbus_message_new_method_call (SDATA (service),
+                                           SDATA (path),
+                                           SDATA (interface),
+                                           SDATA (method));
+  if (dmessage == NULL)
+    {
+      UNGCPRO;
+      xsignal1 (Qdbus_error, build_string ("Unable to create a new message"));
+    }
+
+  UNGCPRO;
+
+  /* Append parameters to the message.  */
+  for (i = 5; i < nargs; ++i)
+    {
+
+      XD_DEBUG_VALID_LISP_OBJECT_P (args[i]);
+      XD_DEBUG_MESSAGE ("Parameter%d %s",
+                        i-4,
+                        SDATA (format2 ("%s", args[i], Qnil)));
+
+      dtype = XD_LISP_OBJECT_TO_DBUS_TYPE (args[i]);
+      if (dtype == DBUS_TYPE_INVALID)
+        xsignal2 (Qdbus_error, build_string ("Not a valid argument"), args[i]);
+
+      value = (char *) xd_retrieve_value (dtype, args[i]);
+
+      if (!dbus_message_append_args (dmessage,
+                                     dtype,
+                                     &value,
+                                     DBUS_TYPE_INVALID))
+        xsignal2 (Qdbus_error,
+                  build_string ("Unable to append argument"), args[i]);
+    }
+
+  /* Send the message.  */
+  dbus_error_init (&derror);
+  reply = dbus_connection_send_with_reply_and_block (connection,
+                                                     dmessage,
+                                                     -1,
+                                                     &derror);
+
+  if (dbus_error_is_set (&derror))
+    XD_ERROR (derror);
+
+  if (reply == NULL)
+    xsignal1 (Qdbus_error, build_string ("No reply"));
+
+  XD_DEBUG_MESSAGE ("Message sent");
+
+  /* Collect the results.  */
+  result = Qnil;
+  GCPRO1 (result);
+
+  if (!dbus_message_iter_init (reply, &iter))
+    {
+      UNGCPRO;
+      xsignal1 (Qdbus_error, build_string ("Cannot read reply"));
+    }
+
+  /* Loop over the parameters of the D-Bus reply message.  Construct a
+     Lisp list, which is returned by `dbus-call-method'.  */
+  while ((dtype = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID)
+    {
+      result = Fcons (xd_retrieve_arg (dtype, &iter), result);
+      dbus_message_iter_next (&iter);
+    }
+
+  /* Cleanup.  */
+  dbus_message_unref (dmessage);
+  dbus_message_unref (reply);
+
+  /* Return the result.  If there is only one single Lisp object,
+     return it as-it-is, otherwise return the reversed list.  */
+  if (XUINT (Flength (result)) == 1)
+    RETURN_UNGCPRO (XCAR (result));
+  else
+    RETURN_UNGCPRO (Fnreverse (result));
+}
+
+DEFUN ("dbus-send-signal", Fdbus_send_signal, Sdbus_send_signal, 5, MANY, 0,
+       doc: /* Send signal SIGNAL on the D-Bus BUS.
+
+BUS is either the symbol `:system' or the symbol `:session'.
+
+SERVICE is the D-Bus service name SIGNAL is sent from.  PATH is the
+D-Bus object path SERVICE is registered at.  INTERFACE is an interface
+offered by SERVICE.  It must provide signal SIGNAL.
+
+All other arguments ARGS are passed to SIGNAL as arguments.  They are
+converted into D-Bus types via the following rules:
+
+  t and nil => DBUS_TYPE_BOOLEAN
+  number    => DBUS_TYPE_UINT32
+  integer   => DBUS_TYPE_INT32
+  float     => DBUS_TYPE_DOUBLE
+  string    => DBUS_TYPE_STRING
+
+Other Lisp objects are not supported as arguments of SIGNAL.
+
+Example:
+
+\(dbus-send-signal
+  :session "Started" "org.gnu.emacs" "/org/gnu/emacs" "org.gnu.emacs")))
+
+usage: (dbus-send-signal BUS SIGNAL SERVICE PATH INTERFACE &rest ARGS)  */)
+     (nargs, args)
+     int nargs;
+     register Lisp_Object *args;
+{
+  Lisp_Object bus, signal, service, path, interface;
+  struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
+  DBusConnection *connection;
+  DBusMessage *dmessage;
+  uint dtype;
+  int i;
+  char *value;
+
+  /* Check parameters.  */
+  bus = args[0];
+  signal = args[1];
+  service = args[2];
+  path = args[3];
+  interface = args[4];
+
+  CHECK_SYMBOL (bus);
+  CHECK_STRING (signal);
+  CHECK_STRING (service);
+  CHECK_STRING (path);
+  CHECK_STRING (interface);
+  GCPRO5 (bus, signal, service, path, interface);
+
+  XD_DEBUG_MESSAGE ("%s %s %s %s",
+                    SDATA (signal),
+                    SDATA (service),
+                    SDATA (path),
+                    SDATA (interface));
+
+  /* Open a connection to the bus.  */
+  connection = xd_initialize (bus);
+
+  /* Create the message.  */
+  dmessage = dbus_message_new_signal (SDATA (path),
+                                      SDATA (interface),
+                                      SDATA (signal));
+  if (dmessage == NULL)
+    {
+      UNGCPRO;
+      xsignal1 (Qdbus_error, build_string ("Unable to create a new message"));
+    }
+
+  UNGCPRO;
+
+  /* Append parameters to the message.  */
+  for (i = 5; i < nargs; ++i)
+    {
+      XD_DEBUG_VALID_LISP_OBJECT_P (args[i]);
+      XD_DEBUG_MESSAGE ("Parameter%d %s",
+                        i-4,
+                        SDATA (format2 ("%s", args[i], Qnil)));
+
+      dtype = XD_LISP_OBJECT_TO_DBUS_TYPE (args[i]);
+      if (dtype == DBUS_TYPE_INVALID)
+        xsignal2 (Qdbus_error, build_string ("Not a valid argument"), args[i]);
+
+      value = (char *) xd_retrieve_value (dtype, args[i]);
+
+      if (!dbus_message_append_args (dmessage,
+                                     dtype,
+                                     &value,
+                                     DBUS_TYPE_INVALID))
+        xsignal2 (Qdbus_error,
+                  build_string ("Unable to append argument"), args[i]);
+    }
+
+  /* Send the message.  The message is just added to the outgoing
+     message queue.  */
+  if (!dbus_connection_send (connection, dmessage, NULL))
+    xsignal1 (Qdbus_error, build_string ("Cannot send message"));
+
+  /* Flush connection to ensure the message is handled.  */
+  dbus_connection_flush (connection);
+
+  XD_DEBUG_MESSAGE ("Signal sent");
+
+  /* Cleanup.  */
+  dbus_message_unref (dmessage);
+
+  /* Return.  */
+  return Qt;
+}
+
+/* Read queued incoming message of the D-Bus BUS.  BUS is a Lisp
+   symbol, either :system or :session.  */
+Lisp_Object
+xd_read_message (bus)
+     Lisp_Object bus;
+{
+  Lisp_Object key;
+  struct gcpro gcpro1;
+  static struct input_event event;
+  DBusConnection *connection;
+  DBusMessage *dmessage;
+  DBusMessageIter iter;
+  uint dtype;
+  char service[1024], path[1024], interface[1024], member[1024];
+
+  /* Open a connection to the bus.  */
+  connection = xd_initialize (bus);
+
+  /* Non blocking read of the next available message.  */
+  dbus_connection_read_write (connection, 0);
+  dmessage = dbus_connection_pop_message (connection);
+
+  /* Return if there is no queued message.  */
+  if (dmessage == NULL)
+    return;
+
+  /* There is a message in the queue.  Construct the D-Bus event.  */
+  XD_DEBUG_MESSAGE ("Event received");
+  EVENT_INIT (event);
+
+  event.kind = DBUS_EVENT;
+  event.frame_or_window = Qnil;
+
+  /* Collect the parameters.  */
+  event.arg = Qnil;
+  GCPRO1 (event.arg);
+
+  if (!dbus_message_iter_init (dmessage, &iter))
+    {
+      UNGCPRO;
+      XD_DEBUG_MESSAGE ("Cannot read event");
+      return;
+    }
+
+  /* Loop over the resulting parameters.  Construct a list.  */
+  while ((dtype = dbus_message_iter_get_arg_type (&iter)) != DBUS_TYPE_INVALID)
+    {
+      event.arg = Fcons (xd_retrieve_arg (dtype, &iter), event.arg);
+      dbus_message_iter_next (&iter);
+    }
+
+  /* The arguments are stored in reverse order.  Reorder them.  */
+  event.arg = Fnreverse (event.arg);
+
+  /* Read service, object path interface and member from the
+     message.  */
+  strcpy (service,   dbus_message_get_sender (dmessage));
+  strcpy (path,      dbus_message_get_path (dmessage));
+  strcpy (interface, dbus_message_get_interface (dmessage));
+  strcpy (member,    dbus_message_get_member (dmessage));
+
+  /* Add them to the event.  */
+  event.arg = Fcons ((member == NULL ? Qnil : build_string (member)),
+                     event.arg);
+  event.arg = Fcons ((interface == NULL ? Qnil : build_string (interface)),
+                     event.arg);
+  event.arg = Fcons ((path == NULL ? Qnil : build_string (path)),
+                     event.arg);
+  event.arg = Fcons ((service == NULL ? Qnil : build_string (service)),
+                     event.arg);
+
+  /* Add the bus symbol to the event.  */
+  event.arg = Fcons (bus, event.arg);
+
+  /* Add the registered function of the message.  */
+  key = list3 (bus,
+               (interface == NULL ? Qnil : build_string (interface)),
+               (member == NULL ? Qnil : build_string (member)));
+  event.arg = Fcons (Fgethash (key, Vdbus_registered_functions_table, Qnil),
+                     event.arg);
+
+  /* Store it into the input event queue.  */
+  kbd_buffer_store_event (&event);
+
+  /* Cleanup.  */
+  dbus_message_unref (dmessage);
+  UNGCPRO;
+}
+
+/* Read queued incoming messages from the system and session buses.  */
+void
+xd_read_queued_messages ()
+{
+
+  /* Vdbus_registered_functions_table will be made as hash table in
+     dbus.el.  When it isn't loaded yet, it doesn't make sense to
+     handle D-Bus messages.  Furthermore, we ignore all Lisp errors
+     during the call.  */
+  if (HASH_TABLE_P (Vdbus_registered_functions_table))
+    {
+      internal_condition_case_1 (xd_read_message, QCdbus_system_bus,
+                                 Qerror, Fidentity);
+      internal_condition_case_1 (xd_read_message, QCdbus_session_bus,
+                                 Qerror, Fidentity);
+    }
+}
+
+DEFUN ("dbus-register-signal", Fdbus_register_signal, Sdbus_register_signal,
+       6, 6, 0,
+       doc: /* Register for signal SIGNAL on the D-Bus BUS.
+
+BUS is either the symbol `:system' or the symbol `:session'.
+
+SERVICE is the D-Bus service name used by the sending D-Bus object.
+It can be either a known name or the unique name of the D-Bus object
+sending the signal.  When SERVICE is nil, related signals from all
+D-Bus objects shall be accepted.
+
+PATH is the D-Bus object path SERVICE is registered.  It can also be
+nil if the path name of incoming signals shall not be checked.
+
+INTERFACE is an interface offered by SERVICE.  It must provide SIGNAL.
+HANDLER is a Lisp function to be called when the signal is received.
+It must accept as arguments the values SIGNAL is sending.  INTERFACE,
+SIGNAL and HANDLER must not be nil.  Example:
+
+\(defun my-signal-handler (device)
+  (message "Device %s added" device))
+
+\(dbus-register-signal
+  :system "DeviceAdded"
+  (dbus-get-name-owner :system "org.freedesktop.Hal")
+  "/org/freedesktop/Hal/Manager" "org.freedesktop.Hal.Manager"
+  'my-signal-handler)
+
+  => (:system "org.freedesktop.Hal.Manager" "DeviceAdded")
+
+`dbus-register-signal' returns an object, which can be used in
+`dbus-unregister-signal' for removing the registration.  */)
+     (bus, signal, service, path, interface, handler)
+     Lisp_Object bus, signal, service, path, interface, handler;
+{
+  Lisp_Object key;
+  DBusConnection *connection;
+  char rule[1024];
+  DBusError derror;
+
+  /* Check parameters.  */
+  CHECK_SYMBOL (bus);
+  CHECK_STRING (signal);
+  if (!NILP (service)) CHECK_STRING (service);
+  if (!NILP (path)) CHECK_STRING (path);
+  CHECK_STRING (interface);
+  CHECK_SYMBOL (handler);
+
+  /* Open a connection to the bus.  */
+  connection = xd_initialize (bus);
+
+  /* Create a rule to receive related signals.  */
+  sprintf (rule,
+           "type='signal',interface='%s',member=%s%",
+           SDATA (interface),
+           SDATA (signal));
+
+  /* Add service and path to the rule if they are non-nil.  */
+  if (!NILP (service))
+    sprintf (rule, "%s,sender='%s'%", rule, SDATA (service));
+
+  if (!NILP (path))
+    sprintf (rule, "%s,path='%s'", rule, SDATA (path));
+
+  /* Add the rule to the bus.  */
+  dbus_error_init (&derror);
+  dbus_bus_add_match (connection, rule, &derror);
+  if (dbus_error_is_set (&derror))
+    XD_ERROR (derror);
+
+  XD_DEBUG_MESSAGE ("Matching rule \"%s\" created", rule);
+
+  /* Create a hash table entry.  */
+  key = list3 (bus, interface, signal);
+  Fputhash (key, handler, Vdbus_registered_functions_table);
+  XD_DEBUG_MESSAGE ("\"%s\" registered with handler \"%s\"",
+                    SDATA (format2 ("%s", key, Qnil)),
+                    SDATA (format2 ("%s", handler, Qnil)));
+
+  /* Return key.  */
+  return key;
+}
+
+DEFUN ("dbus-unregister-signal", Fdbus_unregister_signal, Sdbus_unregister_signal,
+       1, 1, 0,
+       doc: /* Unregister OBJECT from the D-Bus.
+OBJECT must be the result of a preceding `dbus-register-signal' call.  */)
+     (object)
+     Lisp_Object object;
+{
+
+  /* Check parameters.  */
+  CHECK_SYMBOL (object);
+
+  XD_DEBUG_MESSAGE ("\"%s\" unregistered with handler \"%s\"",
+                    SDATA (format2 ("%s", object, Qnil)),
+                    SDATA (format2 ("%s", Fsymbol_function (object), Qnil)));
+
+  /* Unintern the signal symbol.  */
+  Fremhash (object, Vdbus_registered_functions_table);
+
+  /* Return.  */
+  return Qnil;
+}
+
+
+void
+syms_of_dbusbind ()
+{
+
+  Qdbus_get_unique_name = intern ("dbus-get-unique-name");
+  staticpro (&Qdbus_get_unique_name);
+  defsubr (&Sdbus_get_unique_name);
+
+  Qdbus_call_method = intern ("dbus-call-method");
+  staticpro (&Qdbus_call_method);
+  defsubr (&Sdbus_call_method);
+
+  Qdbus_send_signal = intern ("dbus-send-signal");
+  staticpro (&Qdbus_send_signal);
+  defsubr (&Sdbus_send_signal);
+
+  Qdbus_register_signal = intern ("dbus-register-signal");
+  staticpro (&Qdbus_register_signal);
+  defsubr (&Sdbus_register_signal);
+
+  Qdbus_unregister_signal = intern ("dbus-unregister-signal");
+  staticpro (&Qdbus_unregister_signal);
+  defsubr (&Sdbus_unregister_signal);
+
+  Qdbus_error = intern ("dbus-error");
+  staticpro (&Qdbus_error);
+  Fput (Qdbus_error, Qerror_conditions,
+        list2 (Qdbus_error, Qerror));
+  Fput (Qdbus_error, Qerror_message,
+        build_string ("D-Bus error"));
+
+  QCdbus_system_bus = intern (":system");
+  staticpro (&QCdbus_system_bus);
+
+  QCdbus_session_bus = intern (":session");
+  staticpro (&QCdbus_session_bus);
+
+  DEFVAR_LISP ("dbus-registered-functions-table", &Vdbus_registered_functions_table,
+    doc: /* Hash table of registered functions for D-Bus.
+The key in the hash table is the list (BUS INTERFACE MEMBER).  BUS is
+either the symbol `:system' or the symbol `:session'.  INTERFACE is a
+string which denotes a D-Bus interface, and MEMBER, also a string, is
+either a method or a signal INTERFACE is offering.
+
+The value in the hash table a the function to be called when a D-Bus
+message, which matches the key criteria, arrives.  */);
+  /* We initialize Vdbus_registered_functions_table in dbus.el,
+     because we need to define a hash table function first.  */
+  Vdbus_registered_functions_table = Qnil;
+
+  DEFVAR_LISP ("dbus-debug", &Vdbus_debug,
+    doc: /* If non-nil, debug messages of D-Bus bindings are raised.  */);
+#ifdef DBUS_DEBUG
+  Vdbus_debug = Qt;
+#else
+  Vdbus_debug = Qnil;
+#endif
+
+  Fprovide (intern ("dbusbind"), Qnil);
+
+}
+
+#endif /* HAVE_DBUS */
+
+/* arch-tag: 0e828477-b571-4fe4-b559-5c9211bc14b8
+   (do not change this comment) */