(j3.2006) (SC22WG5.4126) Problems created by some compiler extended size options
Fri Nov 13 15:05:49 EST 2009
Craig Rasmussen wrote:
> There was a discussion at the MPI forum regarding the use of extended
> size compiler options. It appears that there some options on some
> compilers that promote integers even if the kind parameter is specified.
> The problem with this is that it breaks the C interoperability
> standard. For example, the code,
> integer(C_INT) :: i
> call bindc_function(i)
> appears to be broken as the variable i will get promoted.
I would hope not, assuming the dummy is declared integer(c_int). Such
'promotion' is really 'convert to the KIND of the dummy'. Since bind(c)
procedures must have explicit interfaces, the KIND of the dummy is
visible. If a compiler blindly converts integers to a particular KIND
even when it is obvious that it would result in a kind mismatch, then
that is indeed evil, and grounds for filing a big.
> Is this a common compiler option? I've been told that users most
> often chose the compiler option that promotes everything, even if an
> explicit kind is provided.
> I think this practice is evil!
> J3 mailing list
> J3 at j3-fortran.org
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