how to inhibit specific warnings ?

[leibowitzn]

I'd like to disable a specific warning in gcc. The man page suggests
using -Wno-#warning where #warning is the name of the warning you'd
like to inhibit.

Now, my problem is mapping the warning gcc spits out to the flag I need
to give gcc. This page:
http://gcc.gnu.org/onlinedocs/gcc-3.2.3/gcc/Warning-Options.html
lists a bunch of flags but I can't seem to find the one that coresponds
to my warning. Is there a simple way to map between gcc output and the
flag?

In this particular case the warning I'd like to inhibit is:
warning: converting to non-pointer type 'int' from NULL

thanks