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.

1 files changed, 10 insertions, 10 deletions

diff --git a/src/libsystemd/sd-bus/bus-control.c b/src/libsystemd/sd-bus/bus-control.c
index 94251fe87c..ff628cfe72 100644
--- a/src/libsystemd/sd-bus/bus-control.c
+++ b/src/libsystemd/sd-bus/bus-control.c
@@ -91,7 +91,7 @@ static int bus_request_name_kernel(sd_bus *bus, const char *name, uint64_t flags
 }
 
 static int bus_request_name_dbus1(sd_bus *bus, const char *name, uint64_t flags) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         uint32_t ret, param = 0;
         int r;
 
@@ -187,7 +187,7 @@ static int bus_release_name_kernel(sd_bus *bus, const char *name) {
 }
 
 static int bus_release_name_dbus1(sd_bus *bus, const char *name) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         uint32_t ret;
         int r;
 
@@ -326,7 +326,7 @@ static int bus_list_names_kernel(sd_bus *bus, char ***acquired, char ***activata
 }
 
 static int bus_list_names_dbus1(sd_bus *bus, char ***acquired, char ***activatable) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         _cleanup_strv_free_ char **x = NULL, **y = NULL;
         int r;
 
@@ -647,7 +647,7 @@ int bus_get_name_creds_kdbus(
                 bool allow_activator,
                 sd_bus_creds **creds) {
 
-        _cleanup_bus_creds_unref_ sd_bus_creds *c = NULL;
+        _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *c = NULL;
         struct kdbus_cmd_info *cmd;
         struct kdbus_info *conn_info;
         size_t size, l;
@@ -753,8 +753,8 @@ static int bus_get_name_creds_dbus1(
                 uint64_t mask,
                 sd_bus_creds **creds) {
 
-        _cleanup_bus_message_unref_ sd_bus_message *reply_unique = NULL, *reply = NULL;
-        _cleanup_bus_creds_unref_ sd_bus_creds *c = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply_unique = NULL, *reply = NULL;
+        _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *c = NULL;
         const char *unique = NULL;
         pid_t pid = 0;
         int r;
@@ -858,7 +858,7 @@ static int bus_get_name_creds_dbus1(
                 }
 
                 if (mask & SD_BUS_CREDS_SELINUX_CONTEXT) {
-                        _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;
                         const void *p = NULL;
                         size_t sz = 0;
 
@@ -930,7 +930,7 @@ _public_ int sd_bus_get_name_creds(
 }
 
 static int bus_get_owner_creds_kdbus(sd_bus *bus, uint64_t mask, sd_bus_creds **ret) {
-        _cleanup_bus_creds_unref_ sd_bus_creds *c = NULL;
+        _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *c = NULL;
         struct kdbus_cmd_info cmd = {
                 .size = sizeof(struct kdbus_cmd_info),
         };
@@ -979,7 +979,7 @@ static int bus_get_owner_creds_kdbus(sd_bus *bus, uint64_t mask, sd_bus_creds **
 }
 
 static int bus_get_owner_creds_dbus1(sd_bus *bus, uint64_t mask, sd_bus_creds **ret) {
-        _cleanup_bus_creds_unref_ sd_bus_creds *c = NULL;
+        _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *c = NULL;
         pid_t pid = 0;
         bool do_label;
         int r;
@@ -1543,7 +1543,7 @@ int bus_remove_match_internal(
 }
 
 _public_ int sd_bus_get_name_machine_id(sd_bus *bus, const char *name, sd_id128_t *machine) {
-        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL, *m = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL, *m = NULL;
         const char *mid;
         int r;