$ cc -O2 -Wall -o leaksendmsg leaksendmsg.c
$ echo BUILD_OK; wc -c leaksendmsg leaksendmsg.c
BUILD_OK
    9200 leaksendmsg
    3083 leaksendmsg.c
   12283 total
(no warnings, no errors — gcc 8.3 [DragonFly] Release/2019-02-22, DragonFly 6.5-DEVELOPMENT guest)