I can never find this man page and I keep forgetting to add the onbld tools man pages to the search path.. so..
http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/tools/cw/cw.1
cw basically converts the sun cc compile options over to something gcc will understand and does the behind the scenes shadow compiling. Outside of onnv-gate this has a lot of uses, but is probably pretty unknown. I'd say if you are building or porting a lot of applications you should take a look. If nothing else you learn how to turn off shadow compiling and shave a few minutes off your nightly onnv-gate build.