#ifdef okay for now - but surely (for this one) we can get round the need for this by modifying the files names in the offline/coupled codebases to be the same.

[JhanSrbinovsky]

          `#ifdef` okay for now - but surely (for this one) we can get round the need for this by modifying the files names in the offline/coupled codebases to be the same.

Originally posted by @har917 in #430 (comment)

I thought I had raised an issue about this, but at a glance it doesnt look like it. Yes change names, as first step, ultimately read surface_types from namelist as in JAC, but as with other use as well - offline doesnt have access to same JULES checks/balances, as well as other stuff. Should at least combine *2 coupled versions and sit with a coupled and an offline version of namelist reader.

[JhanSrbinovsky]

Some further background - title reflect issue raised by @har917 in review of AM3 - CABLE reconciliation. AM3 (partially at least) follows JAC, reading surface_types from a namelist. surface types (note not Fortran TYPEs - integer indexes) are declared in cable_surface_types.F90. AM3/JAC has its own version of this file and hence USEs cable_surface_types throughout. offline does/did not have this and so USEs a hard-wired version in grid_constants_cbl. From memory Ramzi just added one for offline. In porting back AM3 version of CABLE, there were several instances where it USEd cable_surface_types for even more surface types. i.e. EGBL (EverGreen BroadLeaf), EGNL etc. The quickest work-arounds was to just add hard-wired versions alongside the others in grid_constants. Even without these extra types, we still have an IF AM3 - get the type index from cable_surface_types, else if offline get the type index from grid_constants. Being in the header we have to use FPP directives (#ifdef). FPP directives are not popular with the UKMO and possibly not even legal in LFRic. Hence Ians "objection" is a valid concern.

The same module name can indeed be USEd as there are seperate versions picked up by coupled/offline apps. However some additional plumbing needs to be tweaked offline.

I'll submit the PR so you have time to look at it. I dont expect any difference at all, there are no science changes, however a 5-site benchcab test follows: