First, I probably couldn't even do a well written version of the rule in any language. :) Not exactly my strength.
Second, sometimes the best trick you can do to make a build system cleaner, is to change the system it is building.
Though, as I stated elsewhere in this chain. I don't necessary mean to dismiss this effort. Just showing me gymnastics that are required to do something that most people just don't care to do, doesn't endear me to the ill suitability of the context. (Fun metaphor, actually. The fact that my house isn't designed to allow easy gynmastic practices in the living room is not a criticism of the house or of gymnastics. Showing me that a cartwheel will get you hurt there is not really showing me anything relevant.)
