27.5.1 gdb/mi Result Records
In addition to a number of out-of-band notifications, the response to a
gdb/mi command includes one of the following result indications:
     
"^done" [ "," results ]- The synchronous operation was successful, results are the return
values.
     
 "^running"- This result record is equivalent to `^done'.  Historically, it
was output instead of `^done' if the command has resumed the
target.  This behaviour is maintained for backward compatibility, but
all frontends should treat `^done' and `^running'
identically and rely on the `*running' output record to determine
which threads are resumed.
     
 "^connected"- gdb has connected to a remote target.
     
 "^error" "," c-string- The operation failed.  The c-string contains the corresponding
error message.
     
 "^exit"- gdb has terminated.