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.

9 files changed, 33 insertions, 35 deletions

diff --git a/src/network/networkctl.c b/src/network/networkctl.c
index 6fcb3050c7..0234825adb 100644
--- a/src/network/networkctl.c
+++ b/src/network/networkctl.c
@@ -196,8 +196,8 @@ static void setup_state_to_color(const char *state, const char **on, const char
 }
 
 static int list_links(int argc, char *argv[], void *userdata) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         _cleanup_free_ LinkInfo *links = NULL;
         int r, c, i;
 
@@ -228,7 +228,7 @@ static int list_links(int argc, char *argv[], void *userdata) {
 
         for (i = 0; i < c; i++) {
                 _cleanup_free_ char *setup_state = NULL, *operational_state = NULL;
-                _cleanup_device_unref_ sd_device *d = NULL;
+                _cleanup_(sd_device_unrefp) sd_device *d = NULL;
                 const char *on_color_operational, *off_color_operational,
                            *on_color_setup, *off_color_setup;
                 char devid[2 + DECIMAL_STR_MAX(int)];
@@ -297,7 +297,7 @@ static int get_gateway_description(
                 int family,
                 union in_addr_union *gateway,
                 char **gateway_description) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
         sd_netlink_message *m;
         int r;
 
@@ -502,8 +502,8 @@ static int link_status_one(
                 const char *name) {
         _cleanup_strv_free_ char **dns = NULL, **ntp = NULL, **domains = NULL;
         _cleanup_free_ char *setup_state = NULL, *operational_state = NULL, *tz = NULL;
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
-        _cleanup_device_unref_ sd_device *d = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_device_unrefp) sd_device *d = NULL;
         char devid[2 + DECIMAL_STR_MAX(int)];
         _cleanup_free_ char *t = NULL, *network = NULL;
         const char *driver = NULL, *path = NULL, *vendor = NULL, *model = NULL, *link = NULL;
@@ -674,8 +674,8 @@ static int link_status_one(
 }
 
 static int link_status(int argc, char *argv[], void *userdata) {
-        _cleanup_hwdb_unref_ sd_hwdb *hwdb = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_hwdb_unrefp) sd_hwdb *hwdb = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         char **name;
         int r;
 
@@ -720,7 +720,7 @@ static int link_status(int argc, char *argv[], void *userdata) {
         pager_open_if_enabled();
 
         if (arg_all) {
-                _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
                 _cleanup_free_ LinkInfo *links = NULL;
                 int c, i;
 
@@ -906,8 +906,8 @@ static char *lldp_system_caps(uint16_t cap) {
 }
 
 static int link_lldp_status(int argc, char *argv[], void *userdata) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
-        _cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         _cleanup_free_ LinkInfo *links = NULL;
         double ttl = -1;
         uint32_t capability;
diff --git a/src/network/networkd-address.c b/src/network/networkd-address.c
index 1ce1f4d8d6..2d475d6ccc 100644
--- a/src/network/networkd-address.c
+++ b/src/network/networkd-address.c
@@ -408,7 +408,7 @@ int address_get(Link *link, int family, const union in_addr_union *in_addr, unsi
 
 int address_remove(Address *address, Link *link,
                  sd_netlink_message_handler_t callback) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(address);
@@ -503,7 +503,7 @@ static int address_acquire(Link *link, Address *original, Address **ret) {
 }
 
 int address_configure(Address *address, Link *link, sd_netlink_message_handler_t callback, bool update) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(address);
diff --git a/src/network/networkd-fdb.c b/src/network/networkd-fdb.c
index 6e5480ee22..6d819e245b 100644
--- a/src/network/networkd-fdb.c
+++ b/src/network/networkd-fdb.c
@@ -97,7 +97,7 @@ static int set_fdb_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userda
 
 /* send a request to the kernel to add a FDB entry in its static MAC table. */
 int fdb_entry_configure(Link *const link, FdbEntry *const fdb_entry) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         sd_netlink *rtnl;
         int r;
 
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index a9d91b07f6..9811526c6d 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -26,7 +26,6 @@
 #include "alloc-util.h"
 #include "bus-util.h"
 #include "dhcp-lease-internal.h"
-#include "event-util.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "netlink-util.h"
@@ -404,7 +403,7 @@ static void link_free(Link *link) {
 
         free(link->lease_file);
 
-        sd_lldp_free(link->lldp);
+        sd_lldp_unref(link->lldp);
 
         free(link->lldp_file);
 
@@ -1149,7 +1148,7 @@ static int set_mtu_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userda
 }
 
 int link_set_mtu(Link *link, uint32_t mtu) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(link);
@@ -1176,7 +1175,7 @@ int link_set_mtu(Link *link, uint32_t mtu) {
 }
 
 static int link_set_bridge(Link *link) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(link);
@@ -1360,7 +1359,7 @@ static int link_up_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userda
 }
 
 static int link_up(Link *link) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         uint8_t ipv6ll_mode;
         int r;
 
@@ -1447,7 +1446,7 @@ static int link_down_handler(sd_netlink *rtnl, sd_netlink_message *m, void *user
 }
 
 static int link_down(Link *link) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(link);
@@ -2201,7 +2200,7 @@ static int link_initialized_and_synced(sd_netlink *rtnl, sd_netlink_message *m,
 }
 
 int link_initialized(Link *link, struct udev_device *device) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(link);
@@ -2336,7 +2335,7 @@ network_file_fail:
                 for (;;) {
                         Route *route;
                         _cleanup_free_ char *route_str = NULL;
-                        _cleanup_event_source_unref_ sd_event_source *expire = NULL;
+                        _cleanup_(sd_event_source_unrefp) sd_event_source *expire = NULL;
                         usec_t lifetime;
                         char *prefixlen_str;
                         int family;
diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
index 42f58fed19..aeb6e34c52 100644
--- a/src/network/networkd-manager.c
+++ b/src/network/networkd-manager.c
@@ -1151,7 +1151,7 @@ bool manager_should_reload(Manager *m) {
 }
 
 int manager_rtnl_enumerate_links(Manager *m) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
         sd_netlink_message *link;
         int r;
 
@@ -1186,7 +1186,7 @@ int manager_rtnl_enumerate_links(Manager *m) {
 }
 
 int manager_rtnl_enumerate_addresses(Manager *m) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
         sd_netlink_message *addr;
         int r;
 
@@ -1221,7 +1221,7 @@ int manager_rtnl_enumerate_addresses(Manager *m) {
 }
 
 int manager_rtnl_enumerate_routes(Manager *m) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
         sd_netlink_message *route;
         int r;
 
diff --git a/src/network/networkd-netdev-bridge.c b/src/network/networkd-netdev-bridge.c
index a991bdb5fb..e2a099c833 100644
--- a/src/network/networkd-netdev-bridge.c
+++ b/src/network/networkd-netdev-bridge.c
@@ -46,7 +46,7 @@ static int netdev_bridge_set_handler(sd_netlink *rtnl, sd_netlink_message *m, vo
 }
 
 static int netdev_bridge_post_create(NetDev *netdev, Link *link, sd_netlink_message *m) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         Bridge *b;
         int r;
 
diff --git a/src/network/networkd-netdev.c b/src/network/networkd-netdev.c
index a86a6383da..795f24ae4f 100644
--- a/src/network/networkd-netdev.c
+++ b/src/network/networkd-netdev.c
@@ -86,7 +86,7 @@ DEFINE_STRING_TABLE_LOOKUP(netdev_kind, NetDevKind);
 DEFINE_CONFIG_PARSE_ENUM(config_parse_netdev_kind, netdev_kind, NetDevKind, "Failed to parse netdev kind");
 
 static void netdev_cancel_callbacks(NetDev *netdev) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
         netdev_join_callback *callback;
 
         if (!netdev)
@@ -193,7 +193,7 @@ static int netdev_enter_failed(NetDev *netdev) {
 }
 
 static int netdev_enslave_ready(NetDev *netdev, Link* link, sd_netlink_message_handler_t callback) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(netdev);
@@ -290,7 +290,7 @@ int netdev_enslave(NetDev *netdev, Link *link, sd_netlink_message_handler_t call
                 if (r < 0)
                         return r;
         } else if (IN_SET(netdev->state, NETDEV_STATE_LINGER, NETDEV_STATE_FAILED)) {
-                _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 
                 r = rtnl_message_new_synthetic_error(-ENODEV, 0, &m);
                 if (r >= 0)
@@ -470,7 +470,7 @@ static int netdev_create(NetDev *netdev, Link *link,
 
                 log_netdev_debug(netdev, "Created");
         } else {
-                _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
 
                 r = sd_rtnl_message_new_link(netdev->manager->rtnl, &m, RTM_NEWLINK, 0);
                 if (r < 0)
diff --git a/src/network/networkd-route.c b/src/network/networkd-route.c
index ed06c21160..798fe3f647 100644
--- a/src/network/networkd-route.c
+++ b/src/network/networkd-route.c
@@ -21,7 +21,6 @@
 
 #include "alloc-util.h"
 #include "conf-parser.h"
-#include "event-util.h"
 #include "in-addr-util.h"
 #include "netlink-util.h"
 #include "networkd-route.h"
@@ -334,7 +333,7 @@ void route_drop(Route *route) {
 
 int route_remove(Route *route, Link *link,
                sd_netlink_message_handler_t callback) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         int r;
 
         assert(link);
@@ -429,8 +428,8 @@ int route_expire_handler(sd_event_source *s, uint64_t usec, void *userdata) {
 
 int route_configure(Route *route, Link *link,
                     sd_netlink_message_handler_t callback) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
-        _cleanup_event_source_unref_ sd_event_source *expire = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
+        _cleanup_(sd_event_source_unrefp) sd_event_source *expire = NULL;
         usec_t lifetime;
         int r;
 
diff --git a/src/network/networkd-wait-online-manager.c b/src/network/networkd-wait-online-manager.c
index 0c40ab2bb8..c70b370012 100644
--- a/src/network/networkd-wait-online-manager.c
+++ b/src/network/networkd-wait-online-manager.c
@@ -175,7 +175,7 @@ static int on_rtnl_event(sd_netlink *rtnl, sd_netlink_message *mm, void *userdat
 }
 
 static int manager_rtnl_listen(Manager *m) {
-        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
         sd_netlink_message *i;
         int r;