Silence -Wcast-function-type with gcc 8

Casting via void (*)(void) is the documented way to suppress this
warning. This is required because the CPython API treats function
pointers as generic, with flags to indicate different calling
conventions.

Signed-off-by: Simon McVittie <smcv@collabora.com>

8 files changed, 50 insertions, 47 deletions

diff --git a/dbus_bindings/conn-methods.c b/dbus_bindings/conn-methods.c
index 8ae053a..62bdf86 100644
--- a/dbus_bindings/conn-methods.c
+++ b/dbus_bindings/conn-methods.c
@@ -1035,7 +1035,10 @@ PyDoc_STRVAR(set_unique_name__doc__,
 "already been set.\n");
 
 struct PyMethodDef DBusPyConnection_tp_methods[] = {
-#define ENTRY(name, flags) {#name, (PyCFunction)Connection_##name, flags, Connection_##name##__doc__}
+#define ENTRY(name, flags) {\
+    #name, (PyCFunction) (void (*)(void)) Connection_##name, \
+    flags, Connection_##name##__doc__ \
+}
     ENTRY(_require_main_loop, METH_NOARGS),
     ENTRY(close, METH_NOARGS),
     ENTRY(flush, METH_NOARGS),
@@ -1053,13 +1056,13 @@ struct PyMethodDef DBusPyConnection_tp_methods[] = {
     ENTRY(send_message_with_reply_and_block, METH_VARARGS),
     ENTRY(_unregister_object_path, METH_VARARGS|METH_KEYWORDS),
     ENTRY(list_exported_child_objects, METH_VARARGS|METH_KEYWORDS),
-    {"_new_for_bus", (PyCFunction)DBusPyConnection_NewForBus,
+    {"_new_for_bus", (PyCFunction) (void (*)(void)) DBusPyConnection_NewForBus,
         METH_CLASS|METH_VARARGS|METH_KEYWORDS,
         new_for_bus__doc__},
-    {"get_unique_name", (PyCFunction)DBusPyConnection_GetUniqueName,
+    {"get_unique_name", (PyCFunction) (void (*)(void)) DBusPyConnection_GetUniqueName,
         METH_NOARGS,
         get_unique_name__doc__},
-    {"set_unique_name", (PyCFunction)DBusPyConnection_SetUniqueName,
+    {"set_unique_name", (PyCFunction) (void (*)(void)) DBusPyConnection_SetUniqueName,
         METH_VARARGS,
         set_unique_name__doc__},
     ENTRY(set_allow_anonymous, METH_VARARGS),
diff --git a/dbus_bindings/message.c b/dbus_bindings/message.c
index 602a3fb..7c0c192 100644
--- a/dbus_bindings/message.c
+++ b/dbus_bindings/message.c
@@ -783,77 +783,77 @@ Message_set_error_name(Message *self, PyObject *args)
 }
 
 static PyMethodDef Message_tp_methods[] = {
-    {"copy", (PyCFunction)Message_copy,
+    {"copy", (PyCFunction) (void (*)(void)) Message_copy,
       METH_NOARGS, Message_copy__doc__},
-    {"is_method_call", (PyCFunction)Message_is_method_call,
+    {"is_method_call", (PyCFunction) (void (*)(void)) Message_is_method_call,
       METH_VARARGS, Message_is_method_call__doc__},
-    {"is_signal", (PyCFunction)Message_is_signal,
+    {"is_signal", (PyCFunction) (void (*)(void)) Message_is_signal,
       METH_VARARGS, Message_is_signal__doc__},
-    {"is_error", (PyCFunction)Message_is_error,
+    {"is_error", (PyCFunction) (void (*)(void)) Message_is_error,
       METH_VARARGS, Message_is_error__doc__},
 
-    {"get_args_list", (PyCFunction)dbus_py_Message_get_args_list,
+    {"get_args_list", (PyCFunction) (void (*)(void)) dbus_py_Message_get_args_list,
       METH_VARARGS|METH_KEYWORDS, dbus_py_Message_get_args_list__doc__},
-    {"guess_signature", (PyCFunction)dbus_py_Message_guess_signature,
+    {"guess_signature", (PyCFunction) (void (*)(void)) dbus_py_Message_guess_signature,
       METH_VARARGS|METH_STATIC, dbus_py_Message_guess_signature__doc__},
-    {"append", (PyCFunction)dbus_py_Message_append,
+    {"append", (PyCFunction) (void (*)(void)) dbus_py_Message_append,
       METH_VARARGS|METH_KEYWORDS, dbus_py_Message_append__doc__},
 
-    {"get_auto_start", (PyCFunction)Message_get_auto_start,
+    {"get_auto_start", (PyCFunction) (void (*)(void)) Message_get_auto_start,
       METH_NOARGS, Message_get_auto_start__doc__},
-    {"set_auto_start", (PyCFunction)Message_set_auto_start,
+    {"set_auto_start", (PyCFunction) (void (*)(void)) Message_set_auto_start,
       METH_VARARGS, Message_set_auto_start__doc__},
-    {"get_destination", (PyCFunction)Message_get_destination,
+    {"get_destination", (PyCFunction) (void (*)(void)) Message_get_destination,
       METH_NOARGS, Message_get_destination__doc__},
-    {"set_destination", (PyCFunction)Message_set_destination,
+    {"set_destination", (PyCFunction) (void (*)(void)) Message_set_destination,
       METH_VARARGS, Message_set_destination__doc__},
-    {"has_destination", (PyCFunction)Message_has_destination,
+    {"has_destination", (PyCFunction) (void (*)(void)) Message_has_destination,
       METH_VARARGS, Message_has_destination__doc__},
-    {"get_error_name", (PyCFunction)Message_get_error_name,
+    {"get_error_name", (PyCFunction) (void (*)(void)) Message_get_error_name,
       METH_NOARGS, Message_get_error_name__doc__},
-    {"set_error_name", (PyCFunction)Message_set_error_name,
+    {"set_error_name", (PyCFunction) (void (*)(void)) Message_set_error_name,
       METH_VARARGS, Message_set_error_name__doc__},
-    {"get_interface", (PyCFunction)Message_get_interface,
+    {"get_interface", (PyCFunction) (void (*)(void)) Message_get_interface,
       METH_NOARGS, Message_get_interface__doc__},
-    {"set_interface", (PyCFunction)Message_set_interface,
+    {"set_interface", (PyCFunction) (void (*)(void))Message_set_interface,
       METH_VARARGS, Message_set_interface__doc__},
-    {"has_interface", (PyCFunction)Message_has_interface,
+    {"has_interface", (PyCFunction) (void (*)(void))Message_has_interface,
       METH_VARARGS, Message_has_interface__doc__},
-    {"get_member", (PyCFunction)Message_get_member,
+    {"get_member", (PyCFunction) (void (*)(void))Message_get_member,
       METH_NOARGS, Message_get_member__doc__},
-    {"set_member", (PyCFunction)Message_set_member,
+    {"set_member", (PyCFunction) (void (*)(void))Message_set_member,
       METH_VARARGS, Message_set_member__doc__},
-    {"has_member", (PyCFunction)Message_has_member,
+    {"has_member", (PyCFunction) (void (*)(void))Message_has_member,
       METH_VARARGS, Message_has_member__doc__},
-    {"get_path", (PyCFunction)Message_get_path,
+    {"get_path", (PyCFunction) (void (*)(void))Message_get_path,
       METH_NOARGS, Message_get_path__doc__},
-    {"get_path_decomposed", (PyCFunction)Message_get_path_decomposed,
+    {"get_path_decomposed", (PyCFunction) (void (*)(void))Message_get_path_decomposed,
       METH_NOARGS, Message_get_path_decomposed__doc__},
-    {"set_path", (PyCFunction)Message_set_path,
+    {"set_path", (PyCFunction) (void (*)(void))Message_set_path,
       METH_VARARGS, Message_set_path__doc__},
-    {"has_path", (PyCFunction)Message_has_path,
+    {"has_path", (PyCFunction) (void (*)(void))Message_has_path,
       METH_VARARGS, Message_has_path__doc__},
-    {"get_no_reply", (PyCFunction)Message_get_no_reply,
+    {"get_no_reply", (PyCFunction) (void (*)(void))Message_get_no_reply,
       METH_NOARGS, Message_get_no_reply__doc__},
-    {"set_no_reply", (PyCFunction)Message_set_no_reply,
+    {"set_no_reply", (PyCFunction) (void (*)(void))Message_set_no_reply,
       METH_VARARGS, Message_set_no_reply__doc__},
-    {"get_reply_serial", (PyCFunction)Message_get_reply_serial,
+    {"get_reply_serial", (PyCFunction) (void (*)(void))Message_get_reply_serial,
       METH_NOARGS, Message_get_reply_serial__doc__},
-    {"set_reply_serial", (PyCFunction)Message_set_reply_serial,
+    {"set_reply_serial", (PyCFunction) (void (*)(void))Message_set_reply_serial,
       METH_VARARGS, Message_set_reply_serial__doc__},
-    {"get_sender", (PyCFunction)Message_get_sender,
+    {"get_sender", (PyCFunction) (void (*)(void))Message_get_sender,
       METH_NOARGS, Message_get_sender__doc__},
-    {"set_sender", (PyCFunction)Message_set_sender,
+    {"set_sender", (PyCFunction) (void (*)(void))Message_set_sender,
       METH_VARARGS, Message_set_sender__doc__},
-    {"has_sender", (PyCFunction)Message_has_sender,
+    {"has_sender", (PyCFunction) (void (*)(void))Message_has_sender,
       METH_VARARGS, Message_has_sender__doc__},
-    {"get_serial", (PyCFunction)Message_get_serial,
+    {"get_serial", (PyCFunction) (void (*)(void))Message_get_serial,
       METH_NOARGS, Message_get_serial__doc__},
-    {"get_signature", (PyCFunction)Message_get_signature,
+    {"get_signature", (PyCFunction) (void (*)(void))Message_get_signature,
       METH_NOARGS, Message_get_signature__doc__},
-    {"has_signature", (PyCFunction)Message_has_signature,
+    {"has_signature", (PyCFunction) (void (*)(void))Message_has_signature,
       METH_VARARGS, Message_has_signature__doc__},
-    {"get_type", (PyCFunction)Message_get_type,
+    {"get_type", (PyCFunction) (void (*)(void))Message_get_type,
       METH_NOARGS, Message_get_type__doc__},
     {NULL, NULL, 0, NULL}
 };
diff --git a/dbus_bindings/module.c b/dbus_bindings/module.c
index 559d12c..2779bfa 100644
--- a/dbus_bindings/module.c
+++ b/dbus_bindings/module.c
@@ -220,7 +220,7 @@ set_default_main_loop(PyObject *always_null UNUSED,
 }
 
 static PyMethodDef module_functions[] = {
-#define ENTRY(name,flags) {#name, (PyCFunction)name, flags, name##__doc__}
+#define ENTRY(name,flags) {#name, (PyCFunction) (void (*)(void))name, flags, name##__doc__}
     ENTRY(validate_interface_name, METH_VARARGS),
     ENTRY(validate_member_name, METH_VARARGS),
     ENTRY(validate_bus_name, METH_VARARGS|METH_KEYWORDS),
diff --git a/dbus_bindings/pending-call.c b/dbus_bindings/pending-call.c
index d5092db..636095f 100644
--- a/dbus_bindings/pending-call.c
+++ b/dbus_bindings/pending-call.c
@@ -225,11 +225,11 @@ PendingCall_tp_dealloc (PendingCall *self)
 }
 
 static PyMethodDef PendingCall_tp_methods[] = {
-    {"block", (PyCFunction)PendingCall_block, METH_NOARGS,
+    {"block", (PyCFunction) (void (*)(void))PendingCall_block, METH_NOARGS,
      PendingCall_block__doc__},
-    {"cancel", (PyCFunction)PendingCall_cancel, METH_NOARGS,
+    {"cancel", (PyCFunction) (void (*)(void))PendingCall_cancel, METH_NOARGS,
      PendingCall_cancel__doc__},
-    {"get_completed", (PyCFunction)PendingCall_get_completed, METH_NOARGS,
+    {"get_completed", (PyCFunction) (void (*)(void))PendingCall_get_completed, METH_NOARGS,
      PendingCall_get_completed__doc__},
     {NULL, NULL, 0, NULL}
 };
diff --git a/dbus_bindings/server.c b/dbus_bindings/server.c
index 3f2819d..dfbfa53 100644
--- a/dbus_bindings/server.c
+++ b/dbus_bindings/server.c
@@ -535,7 +535,7 @@ Server_get_is_connected (Server *self, PyObject *args UNUSED)
 /* Server type object =============================================== */
 
 struct PyMethodDef DBusPyServer_tp_methods[] = {
-#define ENTRY(name, flags) {#name, (PyCFunction)Server_##name, flags, Server_##name##__doc__}
+#define ENTRY(name, flags) {#name, (PyCFunction) (void (*)(void))Server_##name, flags, Server_##name##__doc__}
     ENTRY(disconnect,       METH_NOARGS),
     ENTRY(get_address,      METH_NOARGS),
     ENTRY(get_id,           METH_NOARGS),
diff --git a/dbus_bindings/unixfd.c b/dbus_bindings/unixfd.c
index 79b513c..8ca6771 100644
--- a/dbus_bindings/unixfd.c
+++ b/dbus_bindings/unixfd.c
@@ -189,7 +189,7 @@ dbus_py_unix_fd_get_fd(PyObject *self)
 }
 
 static PyMethodDef UnixFd_methods[] = {
-    {"take", (PyCFunction) UnixFd_take, METH_NOARGS, UnixFd_take__doc__ },
+    {"take", (PyCFunction) (void (*)(void)) UnixFd_take, METH_NOARGS, UnixFd_take__doc__ },
     {NULL}
 };
 
diff --git a/dbus_glib_bindings/module.c b/dbus_glib_bindings/module.c
index e3e61bc..6614394 100644
--- a/dbus_glib_bindings/module.c
+++ b/dbus_glib_bindings/module.c
@@ -170,7 +170,7 @@ static PyMethodDef module_functions[] = {
     {"setup_with_g_main", setup_with_g_main, METH_VARARGS,
      setup_with_g_main__doc__},
     {"gthreads_init", gthreads_init, METH_NOARGS, gthreads_init__doc__},
-    {"DBusGMainLoop", (PyCFunction)DBusGMainLoop,
+    {"DBusGMainLoop", (PyCFunction) (void (*)(void))DBusGMainLoop,
      METH_VARARGS|METH_KEYWORDS, DBusGMainLoop__doc__},
     {NULL, NULL, 0, NULL}
 };
diff --git a/test/dbus_py_test.c b/test/dbus_py_test.c
index f44b2ff..7f8f996 100644
--- a/test/dbus_py_test.c
+++ b/test/dbus_py_test.c
@@ -114,7 +114,7 @@ UnusableMainLoop (PyObject *always_null UNUSED, PyObject *args, PyObject *kwargs
 }
 
 static PyMethodDef module_functions[] = {
-    {"UnusableMainLoop", (PyCFunction)UnusableMainLoop,
+    {"UnusableMainLoop", (PyCFunction) (void (*)(void))UnusableMainLoop,
      METH_VARARGS|METH_KEYWORDS, "Return a main loop that fails to attach"},
     {NULL, NULL, 0, NULL}
 };