tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy

GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.

With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.

The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).

This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.

Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:

       #define _cleanup_(function) __attribute__((cleanup(function)))

Or similar, to make the gcc feature easier to use.

Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.

See #2008.

4 files changed, 20 insertions, 21 deletions

diff --git a/src/nspawn/nspawn-expose-ports.c b/src/nspawn/nspawn-expose-ports.c
index 38245434da..89e5c57db3 100644
--- a/src/nspawn/nspawn-expose-ports.c
+++ b/src/nspawn/nspawn-expose-ports.c
@@ -211,7 +211,7 @@ int expose_port_watch_rtnl(
                 sd_netlink_message_handler_t handler,
                 union in_addr_union *exposed,
                 sd_netlink **ret) {
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         int fd, r;
 
         assert(event);
diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c
index 8f74c41c71..3104c8e953 100644
--- a/src/nspawn/nspawn-network.c
+++ b/src/nspawn/nspawn-network.c
@@ -94,7 +94,7 @@ static int add_veth(
                 const char *ifname_container,
                 const struct ether_addr *mac_container) {
 
-        _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
         int r;
 
         assert(rtnl);
@@ -163,7 +163,7 @@ int setup_veth(const char *machine_name,
                char iface_name[IFNAMSIZ],
                bool bridge) {
 
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         struct ether_addr mac_host, mac_container;
         int r, i;
 
@@ -204,7 +204,7 @@ int setup_veth_extra(
                 pid_t pid,
                 char **pairs) {
 
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         uint64_t idx = 0;
         char **a, **b;
         int r;
@@ -241,8 +241,8 @@ int setup_veth_extra(
 }
 
 int setup_bridge(const char *veth_name, const char *bridge_name) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         int r, bridge_ifi;
 
         assert(veth_name);
@@ -303,7 +303,7 @@ static int parse_interface(struct udev *udev, const char *name) {
 
 int move_network_interfaces(pid_t pid, char **ifaces) {
         _cleanup_udev_unref_ struct udev *udev = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         char **i;
         int r;
 
@@ -321,7 +321,7 @@ int move_network_interfaces(pid_t pid, char **ifaces) {
         }
 
         STRV_FOREACH(i, ifaces) {
-                _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
                 int ifi;
 
                 ifi = parse_interface(udev, *i);
@@ -346,7 +346,7 @@ int move_network_interfaces(pid_t pid, char **ifaces) {
 
 int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces) {
         _cleanup_udev_unref_ struct udev *udev = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         unsigned idx = 0;
         char **i;
         int r;
@@ -365,7 +365,7 @@ int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces) {
         }
 
         STRV_FOREACH(i, ifaces) {
-                _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
                 _cleanup_free_ char *n = NULL;
                 struct ether_addr mac;
                 int ifi;
@@ -434,7 +434,7 @@ int setup_macvlan(const char *machine_name, pid_t pid, char **ifaces) {
 
 int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces) {
         _cleanup_udev_unref_ struct udev *udev = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         char **i;
         int r;
 
@@ -452,7 +452,7 @@ int setup_ipvlan(const char *machine_name, pid_t pid, char **ifaces) {
         }
 
         STRV_FOREACH(i, ifaces) {
-                _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
                 _cleanup_free_ char *n = NULL;
                 int ifi;
 
diff --git a/src/nspawn/nspawn-register.c b/src/nspawn/nspawn-register.c
index 50871464c5..d6c0200c0c 100644
--- a/src/nspawn/nspawn-register.c
+++ b/src/nspawn/nspawn-register.c
@@ -42,8 +42,8 @@ int register_machine(
                 bool keep_unit,
                 const char *service) {
 
-        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
         int r;
 
         r = sd_bus_default_system(&bus);
@@ -68,7 +68,7 @@ int register_machine(
                                 strempty(directory),
                                 local_ifindex > 0 ? 1 : 0, local_ifindex);
         } else {
-                _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
                 char **i;
                 unsigned j;
 
@@ -199,9 +199,9 @@ int register_machine(
 }
 
 int terminate_machine(pid_t pid) {
-        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
-        _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
         const char *path;
         int r;
 
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index f6a2c0386e..a4e13bd6aa 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -57,7 +57,6 @@
 #include "copy.h"
 #include "dev-setup.h"
 #include "env-util.h"
-#include "event-util.h"
 #include "fd-util.h"
 #include "fdset.h"
 #include "fileio.h"
@@ -3259,9 +3258,9 @@ int main(int argc, char *argv[]) {
                 };
                 int ifi = 0;
                 ssize_t l;
-                _cleanup_event_unref_ sd_event *event = NULL;
+                _cleanup_(sd_event_unrefp) sd_event *event = NULL;
                 _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
-                _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+                _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
                 char last_char = 0;
 
                 r = barrier_create(&barrier);