new target ./setup plain_source?

Hi. What about adding another target ./setup plain_source which should preprocess everything (including cpp) and output the files to an extra directory? Why? This could be used for haddock documentation generation (Not sure how this is done) and perhaps to be read by future IDE's to provide compiler independent completion etc? eg ./setup haddock on haddock sources itself fails on line #if defined(mingw32_HOST_OS) ... What do you think? Marc Weber