feature.h allows to define some preferences for vim. In order to change these preferences, it should be changed before compiling vim. VIMRC_FILE
GVIMRC_FILE
EXREC_FILE
USR_VIMRC_FILE
USR_VIMRC_FILE2
USR_VIMRC_FILE3 RUNTIME_DIRNAME is used in vim_version_dir(). os_dos.h.