Pitfalls of using chatgpt to generate Fortran code

[Beliavsky]

In April I gave a list of eight common errors made by LLMs in their Fortran code, which included the issues mentioned here: forgetting that Fortran is case-insensitive and that declarations must precede executable statements unless block is used.

Cursor rules for Fortran

By default some LLMs will produce Fortran code with default reals. To avoid this, I often instruct them to Declare real variables as real(kind=dp) with dp a kind constant imported from module kind_mod, which I will provide I tell them to put procedures in modules, and in my Fortran agents I tell them to iterate until the code compiles with the gfortran options -O0 -fmax-errors=1 -Wall -Werror=unused-parameter -Werror=unused-variable -Werror=unused-function -Wno-maybe-uninitialized -Wno-su…