Support for non binary target

[dolanor]

My code depend on some cpp file that must be generated. Since a cpp file is a source too, it cannot treat it as a TARGET.
And when I put some custom rule for that cpp to be generated like

mygeneratedfile.cpp : whateverInterfaceHeader.h
@generateFileFromHeader -i whateverInterfaceHeader.h

It will generate a mygeneratedfile.cpp rule, but with nothing under it.

I diagnosed that by doing :
make -p | vi -