Option explanation:

-a  class name
-f  file name
-m  function name
-n  line number
-x  exception
--  expression


Different breakpoint types:
- line: on a file/line combination (req: -f and -n)
- call: on function entrance (req: -m; opt: -a)
- return: on function exit (req: -m; opt: -a)
- exception: on exception of given name (req: -x)
- conditional: when condition is met (req: -- and -f; opt: -n)


Extra options:

-o  hit condition (>=, == or %)
-g  hit value