From: Chris Lattner
$ opt < a.bc > /dev/null -mypass
<no output>
$ opt < a.bc > /dev/null -mypass -debug
I am here!
$
Using the DEBUG() macro instead of a home-brewed solution -allows you to now have to create "yet another" command line option for +allows you to not have to create "yet another" command line option for the debug output for your pass. Note that DEBUG() macros are disabled for optimized builds, so they do not cause a performance impact at all (for the same reason, they should also not contain