[Bug fortran/57711] Accepts non-matching invalid dummy procedure as actual argument

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57711

--- Comment #6 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Patch for PR40276 and this PR:
http://gcc.gnu.org/ml/fortran/2013-06/msg00132.html (approved).

It fails for the test case http://gcc.gnu.org/ml/fortran/2013-07/msg00017.html
(-> PR39290 and PR20896). In that test case, "s1" and "s2" are ambiguous in
F2003/F2008.

However, I fear that the check in the patch above will give a bogus error for
  interface gen
    subroutine s1(x)
      real, external :: x
    end subroutine s1
    subroutine s1(x)
      integer, external :: x
    end subroutine s1
  end interface
which is valid since F2008 ("both data objects or known to be functions, and
neither is TKR compatible with the other,", 12.4.3.4.5). The issue does not
occur yet, as the feature is not yet implemented.