On Oct 22 2013, Jeff Hammond wrote:

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However, I have always felt that the original C approach was a horrible hack, just as having C's argument list (and arguments) writable is. There were good reasons at the time but, given that Fortran has done without it with little to no trouble for so long, I agree with Bill.

I do not see how Fortran has any power to fix this any more than C does. The perceived superiority of Fortran over C is not a valid argument within the MPI Forum. The MPI Forum only addressed the C case because Fortran did not have a standard way to access argc/argv until the 2003 specification.

That's not my point. It didn't have to (ab)use it. MPI_Init could have returned an integer saying how many arguments it had used, and not updated the list at all. I know that the C standard permits the argument list and arguments to be written to, but that was because adding const would have broken K&R codes. Some people on WG14 wanted that to be explicitly undefined, and it was (is?) a seriously bad idea in some implementations. Inter alia, it is on any system where the run-time system uses related tricks. Implementing it on any system where the arguments are provided as read-only (as read-only data should be), or when any library call needs to access them, or on any system which passes references to the same arguments to all processes started by mpiexec/mpirun, is a real pain. All can be kludged up (I have), but it's totally unnecessary and horrible hackery.

I do not understand your apparent argument that argc/argv are not useful. Do you assume that Fortran applications always use the exact same input filename? I know many Fortran codes that do this and it's really sad to see how they contort to provide a general workflow.

I never said that, nor did I imply it. It's the hackery that I dislike. In addition to the above, MPI_Init(int *argc, char ***argv) was NOT compatible with the normative wording of C90, nor does it say that MPI_Init MUST change argc and argv. And, lastly, MPI 3.0 already defines a way of getting this that is the same in both Fortran and C - using MPI_INFO_ENV. Regards, Nick Maclaren.