discouraged-function

Flag a call to a function on a configurable deny-list. The built-in set covers Base functions with process-wide or memory-unsafe effects — exit, cd, redirect_stdout, redirect_stderr, and the unsafe_*/pointer conversions — each reported with the alternative to reach for.

Configure it under [lint.rules.discouraged-function]: functions replaces the built-in set, extend-functions adds to it (an entry there also rewords a built-in), and functions = {} silences the rule without ignoring it. Both are tables mapping a function name to the suggestion shown in the diagnostic.

A call carrying a do block is never reported, since for cd and the redirect_* functions that form is the recommended alternative. A qualified callee (Base.exit) is a different name and does not match. A built-in name is only reported once it is confirmed to be Base’s, so a local of the same name — or a file whose imports cannot be resolved — reports nothing; a name the project configured is reported unless a definition in the same file shadows it. No fix is offered, since the rewrite is a judgment call.

exit ends the process and cd leaves the working directory changed:

function cleanup()
    cd("/tmp")
    exit(1)
end

warning: discouraged-function
 --> example.jl:2:5
  |
2 |     cd("/tmp")
  |     ^^ `cd` is discouraged: use the `cd(f, dir)` do-block form so the working directory is restored
warning: discouraged-function
 --> example.jl:3:5
  |
3 |     exit(1)
  |     ^^^^ `exit` is discouraged: let the caller decide when the process ends