http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55465
--- Comment #13 from Juno Krahn <juno.krahn at nih dot gov> 2012-11-30 17:21:08 UTC --- This issue was once discussed by members of the Fortran standards committee. I don't recall if that was on usenet or somewhere in the committee meeting notes. The conclusion was that it is useful to allow for multiple explicit interfaces in order to interface correctly with C libraries, and that the standards allow for it. The standards state that the defined interface must be compatible with the C routine, but there are multiple ways to define a single interface. For example, a pointer argument can be a pass-by-reference or just a C pointer. It might make sense to validate that each interface spec does in fact have the same binary call signature. Depending on compiler internals, that may be difficult to implement. In any case, it might be good to keep this as an optional warning because it is not that common and could in fact be an error. As for previous comments, yes someone should report this problem to NAG and IBM.
