libsystemd: introduce _sd_destroy_t

src/systemd/_sd-common.h

@@ -23,6 +23,8 @@
 #  error "Do not include _sd-common.h directly; it is a private header."
 #endif
 
+typedef void (*_sd_destroy_t)(void *userdata);
+
 #ifndef _sd_printf_
 #  if __GNUC__ >= 4
 #    define _sd_printf_(a,b) __attribute__ ((__format__(printf, a, b)))

src/systemd/sd-bus.h

@@ -107,7 +107,7 @@ typedef int (*sd_bus_property_set_t) (sd_bus *bus, const char *path, const char
 typedef int (*sd_bus_object_find_t) (sd_bus *bus, const char *path, const char *interface, void *userdata, void **ret_found, sd_bus_error *ret_error);
 typedef int (*sd_bus_node_enumerator_t) (sd_bus *bus, const char *prefix, void *userdata, char ***ret_nodes, sd_bus_error *ret_error);
 typedef int (*sd_bus_track_handler_t) (sd_bus_track *track, void *userdata);
-typedef void (*sd_bus_destroy_t)(void *userdata);
+typedef _sd_destroy_t sd_bus_destroy_t;
 
 #include "sd-bus-protocol.h"
 #include "sd-bus-vtable.h"

src/systemd/sd-event.h

@@ -77,7 +77,7 @@ typedef int (*sd_event_child_handler_t)(sd_event_source *s, const siginfo_t *si,
 typedef void* sd_event_child_handler_t;
 #endif
 typedef int (*sd_event_inotify_handler_t)(sd_event_source *s, const struct inotify_event *event, void *userdata);
-typedef void (*sd_event_destroy_t)(void *userdata);
+typedef _sd_destroy_t sd_event_destroy_t;
 
 int sd_event_default(sd_event **e);
 

src/systemd/sd-netlink.h

@@ -39,7 +39,7 @@ typedef enum {SD_GENL_ID_CTRL, SD_GENL_WIREGUARD, SD_GENL_FOU} sd_genl_family;
 /* callback */
 
 typedef int (*sd_netlink_message_handler_t)(sd_netlink *nl, sd_netlink_message *m, void *userdata);
-typedef void (*sd_netlink_destroy_t)(void *userdata);
+typedef _sd_destroy_t sd_netlink_destroy_t;
 
 /* bus */
 int sd_netlink_new_from_netlink(sd_netlink **nl, int fd);

src/systemd/sd-resolve.h

@@ -42,7 +42,7 @@ typedef struct sd_resolve_query sd_resolve_query;
 /* A callback on completion */
 typedef int (*sd_resolve_getaddrinfo_handler_t)(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata);
 typedef int (*sd_resolve_getnameinfo_handler_t)(sd_resolve_query *q, int ret, const char *host, const char *serv, void *userdata);
-typedef void (*sd_resolve_destroy_t)(void *userdata);
+typedef _sd_destroy_t sd_resolve_destroy_t;
 
 enum {
         SD_RESOLVE_GET_HOST    = 1 << 0,