SerialBox doesn't seem to understand "module function" or "module subroutine" syntax

[christopherwharrop-noaa]

When pre-processing a Fortran code with pp_ser.py I get this error:

[ 20%] Preprocessing for serialization
cd /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/build/src/fortran && /home/Christopher.W.Harrop/miniconda3/bin/python /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/serialbox2/src/serialbox-python/pp_ser/pp_ser.py --verbose --ignore-identical --output-dir=/scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/build/src/fortran/serialbox_pp /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_netcdf_utils.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_kind.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_geometry_config.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_model_config.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_geometry.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_state.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_model.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_tl.f90 /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_adj.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_netcdf_utils.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_kind.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_geometry_config.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_model_config.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_geometry.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_state.f90
Processing file /scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_model.f90
File: "/scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/src/fortran/module_shallow_water_model.f90", line 72
Message: Unexpected module statement
Line 72:     module function constructor_tl(config, geometry) result(this)

make[2]: *** [src/fortran/serialbox_pp/module_netcdf_utils.f90] Error 1
make[2]: *** Deleting file `src/fortran/serialbox_pp/module_netcdf_utils.f90'
make[2]: Leaving directory `/scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/build'
make[1]: *** [src/fortran/CMakeFiles/shallow_water_ser.dir/all] Error 2
make[1]: Leaving directory `/scratch2/BMC/gsd-hpcs/Christopher.W.Harrop/GT4Py/SENA-shallow-water/build'
make: *** [all] Error 2
[Christopher.W.Harrop@Hera:hfe09 build]$ 

The offending line is a declaration of a module function in a module interface block. This code uses Fortran Submodules, which is why "module function" is used here. See line 72 here.

This code is valid Fortran and builds fine with gfortran and Intel. Is this a known limitation of SerialBox? Or a bug?

[havogt]

Thanks for your report and sorry for my late reply.

I would classify this as a bug. Unfortunately, we cannot easily invest resources to fix problems appearing in codes outside of our collaborations.

However, this is an open source project and we happily take contributions to improve Serialbox (after signing the contributor agreement).

Alternatively, it might increase the chance to get a fix if you provide a minimal standalone example that reproduces the issue (stackoverflow style https://stackoverflow.com/help/minimal-reproducible-example).