UCL ARC Fortran Tooling Recommendations and Examples

This repository aims to improve Fortran best practices within UCL and the wider Fortran community by documenting a growing list of Fortran tools recommended by UCL ARC.

Topics covered

• benchmarking
• building
• compiling
• debugging
• documentation
• formatting
• interfaces
• libraries
• package management
• profiling and tracing
• testing

ARC Fortran projects

Name	Start	End	Repo	Opportunity	Tools	Lessons
LFRic	Sept 2024	March 2025	GitHub	#594	Rose, Cylc
CONQUEST	May 2023	May 2024	GitHub	#781	Make, VTune, Advisor
ALPS	Aug 2022	Jul 2023	GitHub	#691	Autotools, Ford
FruitDemand	Apr 2021	Mar 2023		#382	Make, Ford, PFUnit
Trove	Jan 2021	Aug 2021	GitHub	#404	Make, pFUnit (see the PR)
Zacros	Jan 2021	Sep 2022		#349 & older	CMake, CTest

src code

There are two src codes within this repository mesh_generator and poisson. These are designed to work together.

• mesh_generator generates a basic square 2D triangular mesh (see mesh_generator.f90 for more details).
• poisson is a solver which finds the solution of the steady-state heat conduction equation represented by the Poisson equation over a 2D triangular mesh (see poisson.f90 for more details).

Building

A bash script is provided for building (build.sh). However, there are some instructions below for building without this script.

CMake

Note: we have some pFUnit tests which require a local version of pFUnit to be pre-built on your device. Once built, the path to the pFUnit installed dir will need to be passed via -DCMAKE_PREFIX_PATH.

One build system we are utilising is cmake (see CMakeLists.txt). Therefore, to build this repository, please run the following

cmake -DCMAKE_PREFIX_PATH=/path/to/pfunit/installed/dir -B build-cmake 

This will create a build directory from within which the project can be compiled...

cmake --build build-cmake

This will produce executables for the two src codes, fortran-tooling-mesh-generator and fortran-tooling-poisson.

FPM

To build the project using FPM, from the root of the repo, run

fpm build

Running the src

Mesh generator

If you have built using CMake, you can run the mesh generator by directly calling the executable

./build/fortran-tooling-mesh-generator <box_size> <edge_size>

If you have built using FPM, you can also run the mesh generator via FPM

fpm run mesh_generator -- <box_size> <edge_size>

Poisson solver

If you have built using CMake, you can also run the poisson solver by directly calling the executable

./build/fortran-tooling-poisson <path_to_mesh_file>

If you have built using FPM, you can also run the mesh generator via FPM

fpm run poisson -- <path_to_mesh_file>

Running the tests

If you have built using CMake, you can run the tests by running the following from within the build-cmake directory.

ctest

If you have built using FPM, you can run the tests by running the following from the root of the repo

fpm test

pre-commit

pre-commit is utilised within this repo. pre-commit is a tool to help enforce formatting standards as early as possible. pre-commit works by running a provided set of checks every time a git commit is attempted.

To utilise pre-commit, it must be installed locally. This can be done in several ways but the easiest is to use the provided pyproject.toml via...

python3 -m venv .venv
source .venv/bin/activate
python -m pip install -e .

Then, from the root of the repo, you start using pre-commit by running

pre-commit install