I've updated my GNAT/Emacs Ada path utilities gnatpmake and adapath.el
at <http://www.pogner.demon.co.uk/gnatpmake/>.

gnatpmake automates the management of GNAT Ada program libraries (in a
simple way) by the use of a special file (.adapath) which is
optionally present in each program library directory. Each .adapath
file specifies the paths used for compilation of the library directory
in which it is found.

adapath.el contains an Emacs function adapath which manages the
directory search lists used to find files from Ada and compilation

Both are now available under the GPL.