Replace :erlang.exit with :erlang.nif_error to suppress Dialyzer warnings

[japhib]

Currently when you run Dialyzer on a project that depends on libsalty2, you get a warning that every function calling a libsalty2 function will never return. This is because Dialyzer just sees the :erlang.exit in the placeholder implementation and thinks that's the real implementation. The way around this is to use :erlang.nif_error in its place: https://www.erlang.org/doc/man/erlang.html#nif_error-1

From the docs:

Works exactly like error/1, but Dialyzer thinks that this BIF will return an arbitrary term. When used in a stub function for a NIF to generate an exception when the NIF library is not loaded, Dialyzer does not generate false warnings.

The only functional difference is that it'll raise an error instead of just immediately exiting. I'm assuming that's fine though?

[andrew-lewin]

@Ianleeclark Just bumping this since it's been a year and I'm also running into the same issue.

[hazen]

Thank you so much for this @japhib! I spent much time trying to figure out why Dialyzer was failing for me.