Re: [Patch, Fortran] Add caf_runtime_error to libgfortran/caf/single.c

[Tobias Burnus <burnus@net-b.de>]

Janne Blomqvist wrote:
>         * caf/mpi.c (caf_runtime_error): Remove "error" parameter.
>         Return EXIT_FAILURE instead.
> > From the patch:
>
>   /* FIXME: Shutdown the Fortran RTL to flush the buffer.  PR 43849.  */
>
> This is unnecessary, as the call to exit() will call the libgfortran
> destructor which will close all units, as explained in comment #3 in
> the PR.

While I think it should be sufficient for single-processor usage, I am 
not sure that that way all I/O buffers gets written before one calls 
MPI_Finalize - nor am I sure how one would handle ERROR STOP with 
regards to I/O.

In terms of I/O, there are three kinds of I/O, which might need to be 
treated differently:
* I/O to stdout (OUTPUT_UNIT): Here, all output should be collected by 
MPI - I am not sure whether it will come to later in a destructor
* I/O to (local) files
* I/O via the communication library: Here, I see the greatest problems, 
but that's not in F2008's coarrays, but might well be added with the 
Technical Report.

I somehow would feel better if I could ensure that the buffers are 
flushed and the files closed before I pull the MPI plug (MPI_Finalize, 
MPI_Abort).

For reference, the comment Janne is referring to is the one at the 
bottom (comment 3) of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43849

Tobias