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.

2 files changed, 5 insertions, 5 deletions

diff --git a/src/resolve/resolved-bus.c b/src/resolve/resolved-bus.c
index 62bb08a2e8..f86c4ceb05 100644
--- a/src/resolve/resolved-bus.c
+++ b/src/resolve/resolved-bus.c
@@ -61,7 +61,7 @@ static int reply_query_state(DnsQuery *q) {
                 return sd_bus_reply_method_errorf(q->request, BUS_ERROR_ABORTED, "Query aborted");
 
         case DNS_TRANSACTION_FAILURE: {
-                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 
                 if (q->answer_rcode == DNS_RCODE_NXDOMAIN)
                         sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", name);
@@ -132,7 +132,7 @@ static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifin
 
 static void bus_method_resolve_hostname_complete(DnsQuery *q) {
         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *canonical = NULL;
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         unsigned added = 0;
         int r;
 
@@ -286,7 +286,7 @@ fail:
 }
 
 static void bus_method_resolve_address_complete(DnsQuery *q) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         DnsResourceRecord *rr;
         unsigned added = 0;
         int ifindex, r;
@@ -461,7 +461,7 @@ static int bus_message_append_rr(sd_bus_message *m, DnsResourceRecord *rr, int i
 }
 
 static void bus_method_resolve_record_complete(DnsQuery *q) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         unsigned added = 0;
         int r;
 
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index f1f454c786..62562f0d24 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -193,7 +193,7 @@ fail:
 }
 
 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;