Add MESG as a new log domain.

doc/tor.1.txt

@@ -679,7 +679,7 @@ GENERAL OPTIONS
     The currently recognized domains are: general, crypto, net, config, fs,
     protocol, mm, http, app, control, circ, rend, bug, dir, dirserv, or, edge,
     acct, hist, handshake, heartbeat, channel, sched, guard, consdiff, dos,
-    process, pt, and btrack.
+    process, pt, btrack, and mesg.
     Domain names are case-insensitive. +
  +
     For example, "`Log [handshake]debug [~net,~mm]info notice stdout`" sends

src/lib/log/log.c

@@ -49,6 +49,7 @@
 #include "lib/wallclock/approx_time.h"
 #include "lib/wallclock/time_to_tm.h"
 #include "lib/fdio/fdio.h"
+#include "lib/cc/ctassert.h"
 
 #ifdef HAVE_ANDROID_LOG_H
 #include <android/log.h>
@@ -1268,9 +1269,12 @@ static const char *domain_list[] = {
   "GENERAL", "CRYPTO", "NET", "CONFIG", "FS", "PROTOCOL", "MM",
   "HTTP", "APP", "CONTROL", "CIRC", "REND", "BUG", "DIR", "DIRSERV",
   "OR", "EDGE", "ACCT", "HIST", "HANDSHAKE", "HEARTBEAT", "CHANNEL",
-  "SCHED", "GUARD", "CONSDIFF", "DOS", "PROCESS", "PT", "BTRACK", NULL
+  "SCHED", "GUARD", "CONSDIFF", "DOS", "PROCESS", "PT", "BTRACK", "MESG",
+  NULL
 };
 
+CTASSERT(ARRAY_LENGTH(domain_list) == N_LOGGING_DOMAINS + 1);
+
 /** Return a bitmask for the log domain for which <b>domain</b> is the name,
  * or 0 if there is no such name. */
 static log_domain_mask_t

src/lib/log/log.h

@@ -113,8 +113,9 @@
 #define LD_PT        (1u<<27)
 /** Bootstrap tracker. */
 #define LD_BTRACK    (1u<<28)
-/** Number of logging domains in the code. */
-#define N_LOGGING_DOMAINS 29
+/** Message-passing backend. */
+#define LD_MESG      (1u<<29)
+#define N_LOGGING_DOMAINS 30
 
 /** This log message is not safe to send to a callback-based logger
  * immediately.  Used as a flag, not a log domain. */