3 # this file set the sub dir in src code.
4 # while a large number of src file to be compiled, it cost much more memory resource with loading them once a time.
5 # different src-dir compiled to one object file, link those code by one object file, instead of many object files.
6 # it also let the long compile list to be several parts. compile step seperated into several steps.
7 # the specified sub dir contains a dir named 'build', it stores c-src-file.list as the src pkg it be. sometimes,
8 # it can set different compile paramter for all src code in a dir.