There is a technical report (TR 29113) in preparation to allow "Further Interoperability of Fortran with C".
Last draft is:
One thing one presumably needs to change is the way ALLOCATBLE,INTENT(OUT) variables are auto-deallocated: Currently, it happens in the caller. I think for the TR one needs to make it happen in the callee.
Note: The draft N1761 is the result of the subgroup. Not all WG5/J3 members are happy with the proposal. At the February 2009 meeting it will be discussed with all members (cf. ftp://ftp.nag.co.uk/sc22wg5/N1751-N1800/N1794.txt).
See also http://gcc.gnu.org/wiki/ArrayDescriptorUpdate
Latest draft: ftp://ftp.nag.co.uk/sc22wg5/N1801-N1850/N1808.pdf
Time line: ftp://ftp.nag.co.uk/sc22wg5/N1801-N1850/N1812.txt (-> 2nd draft: 2010-10)