tree-wide: add SD_ID128_MAKE_STR, remove LOG_MESSAGE_ID

Embedding sd_id128_t's in constant strings was rather cumbersome. We had
SD_ID128_CONST_STR which returned a const char[], but it had two problems:
- it wasn't possible to statically concatanate this array with a normal string
- gcc wasn't really able to optimize this, and generated code to perform the
  "conversion" at runtime.
Because of this, even our own code in coredumpctl wasn't using
SD_ID128_CONST_STR.

Add a new macro to generate a constant string: SD_ID128_MAKE_STR.
It is not as elegant as SD_ID128_CONST_STR, because it requires a repetition
of the numbers, but in practice it is more convenient to use, and allows gcc
to generate smarter code:

$ size .libs/elogind{,-logind,-journald}{.old,}
   text	   data	    bss	    dec	    hex	filename
1265204	 149564	   4808	1419576	 15a938	.libs/elogind.old
1260268	 149564	   4808	1414640	 1595f0	.libs/elogind
 246805	  13852	    209	 260866	  3fb02	.libs/elogind-logind.old
 240973	  13852	    209	 255034	  3e43a	.libs/elogind-logind
 146839	   4984	     34	 151857	  25131	.libs/elogind-journald.old
 146391	   4984	     34	 151409	  24f71	.libs/elogind-journald

It is also much easier to check if a certain binary uses a certain MESSAGE_ID:

$ strings .libs/elogind.old|grep MESSAGE_ID
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x

$ strings .libs/elogind|grep MESSAGE_ID
MESSAGE_ID=c7a787079b354eaaa9e77b371893cd27
MESSAGE_ID=b07a249cd024414a82dd00cd181378ff
MESSAGE_ID=641257651c1b4ec9a8624d7a40a9e1e7
MESSAGE_ID=de5b426a63be47a7b6ac3eaac82e2f6f
MESSAGE_ID=d34d037fff1847e6ae669a370e694725
MESSAGE_ID=7d4958e842da4a758f6c1cdc7b36dcc5
MESSAGE_ID=1dee0369c7fc4736b7099b38ecb46ee7
MESSAGE_ID=39f53479d3a045ac8e11786248231fbf
MESSAGE_ID=be02cf6855d2428ba40df7e9d022f03d
MESSAGE_ID=7b05ebc668384222baa8881179cfda54
MESSAGE_ID=9d1aaa27d60140bd96365438aad20286

1 files changed, 6 insertions, 11 deletions

diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index 26b6c3a92..971b447a7 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -34,7 +34,7 @@
 #include "escape.h"
 #include "fd-util.h"
 #include "fileio-label.h"
-#include "formats-util.h"
+#include "format-util.h"
 #include "fs-util.h"
 #include "logind.h"
 #include "mkdir.h"
@@ -1301,8 +1301,7 @@ static int flush_devices(Manager *m) {
         } else {
                 struct dirent *de;
 
-                while ((de = readdir(d))) {
-
+                FOREACH_DIRENT_ALL(de, d, break) {
                         if (!dirent_is_file(de))
                                 continue;
 
@@ -1447,7 +1446,7 @@ static int bus_manager_log_shutdown(
                 p = strjoina(p, " (", m->wall_message, ").");
 
         return log_struct(LOG_NOTICE,
-                          LOG_MESSAGE_ID(SD_MESSAGE_SHUTDOWN),
+                          "MESSAGE_ID=" SD_MESSAGE_SHUTDOWN_STR,
                           p,
                           q,
                           NULL);
@@ -2465,13 +2464,9 @@ static int method_set_wall_message(
                 return 1; /* Will call us back */
 #endif // 0
 
-        if (isempty(wall_message))
-                m->wall_message = mfree(m->wall_message);
-        else {
-                r = free_and_strdup(&m->wall_message, wall_message);
-                if (r < 0)
-                        return log_oom();
-        }
+        r = free_and_strdup(&m->wall_message, empty_to_null(wall_message));
+        if (r < 0)
+                return log_oom();
 
         m->enable_wall_messages = enable_wall_messages;