[Haskell-beginners] Handling cpp and hsc2hs with Distribution.Simple

[Maurí­cio]

Cabal package manual says those tools are handled
automatically using extensions in file names, i.e.,
'.hsc' for hsc2hs and '.cpphs' for haskell cpp.

What should I do if I want both, i.e., I would
like my file to be processed first by cpp and then
by hsc2hs?

Thanks,
Maurício