Problem with fortran compilation of source in github

[Charles Brooks]

Dear Peter,

I pulled the github repository to build from this for testing/development of the OpenMM/CHARMM interface and find that (differing from the 6.2 release code) that there are two function names that exceed the maximum allowed in length of a function/subroutine name in fortran2003 of 63 characters, these are the functions:

OpenMM_MonteCarloAnisotropicBarostat_usesPeriodicBoundaryConditions 67 char
OpenMM_MonteCarloMembraneBarostat_usesPeriodicBoundaryConditions 64 char


This inhibits builds of any of the fortran code, because the fortran compiler chokes on OpenMMFortranModule.f90.

Is it straightforward to shorten these names?

Thanks,

Charlie

[Michael Sherman]

Hi, Charlie. A possible workaround -- your Fortran compiler may permit use of longer identifiers (though non-standard). For example, gfortran has a command line flag -fmax-identifier-length=n.

Regards,
Sherm

[Peter Eastman]

Fortran makes me sad.

How about if the Fortran wrapper just truncated the names to 63 characters? Those particular functions aren't even ones that users are likely to call.

Peter

[Charles Brooks]

Dear Michael and Peter,

Unfortunately, even though the option to increase the identifier length exists, it cannot go beyond 62:

Fatal Error: Maximum supported identifier length is 63

Thus, this isn't a solution. I have simply commented out those two functions in the fortran wrapper as a temporary fix, but it may be the case that the MCBarostat for membranes (which is related to what we did here, I think) will be used and needed in the future. Thus truncating the names, or commenting out the routines isn't a longer term fix. Also, as I think I noted, one cannot build the f90 examples because of this as well.

Finally, the reason I compiled this was to be able to take advantage of Peter's bug fix to the issue with the CustomCOmpoundBondForce, however, as demonstrated with the attached tar file providing a simple test that if I either of the two CustomCoumpoundBondForces I get a result (which I've verified is correct), but if I apply both at once, only one of them is computed (it happens to be the first one). I think this too is a bug, and that the two forces should be additive. Can you let me know?

Thanks,

Charlie

[Peter Eastman]

Truncating the names wouldn't prevent you from calling them. It would just make it a little less convenient. But like I said, these aren't methods that users are actually expected to call. They exist primarily for internal use.

Peter

[Peter Eastman]

I merged the change so it truncates function names to 63 characters. I verified that the Fortran examples now compile.

Peter