Two years ago I convinced my institute to use Phabricator to develop our FEM solver and all related software projects mostly written in FORTRAN.
We are using more and more features coming with Phabricator and currently want to improve our craft. Therefore we want to use the linting feature coming with Arcanist to lint our FORTRAN code.
My approach would use gfortran, as a colleague and I wrote a tool to clean up our code and I used gfortran as a linter already:
https://github.com/rscircus/fortress/blob/master/fortress/lib/fortress_linter.py
To be honest, I already started to implement this solution into arcanist. However, I read the Phabricator Contributing Code guideline, thus start a discussion here. I'm willing to throw my current solution into the trash, if you can convince me of a better solution. :-)
Adding lints is on hold for now; I'm merging this into T10038 which discusses the issue.
You can implement your linter as an extension - Community Resources has some examples of external linters you can copy.