I believe that the name of this attribute was intentionally chosen so it could never be written down. This attribute allows a module to entirely bypass all privacy restrictions which is a little worrisome to allow on a general basis.

That being said, I would very much like to say --test --pretty expanded and have it "just work". I'm not entirely sure how to do it without breaking privacy, though...

Hm, I didn't realize that's what it was doing. Having an attribute that does that feels a little icky. Is that mainly so we can write:

#[test]
fn test_foo() { ... }

Instead of:

#[test]
pub fn test_foo() { ... }

? If so, i don't think adding pub is that painful, so I question the worth of #[!resolve_unexported]. However, if there is a case I'm not thinking of, I suppose we could put some warning flags around it, with something like #[__unsafe_unstable_resolve_unexported] or something.

@erickt the whole module path has to be pub, not just the #[test] fn itself.

Another possible solution to this problem would be to just not print the module with --pretty expanded --test. That would require passing --test both times, but it would make the expanded source equivalent?

Yet another possible approach: rename !resolve_unexported into test.
rustc strips #[test]/#[bench] codes if --test is not given, so the expanded code will be valid.
(Or conversely, we may add resolve_unexported to rustc::front::strip_test_functions.)

@klutzy's idea of adding resolve_unexported to rustc::front::strip_test_functions seems pretty reasonable to me. How do the rest of you feel about this solution?

This seems isolated to pretty printing, and I would rather just not print the #![resolve_unexported] module during pretty printing.

If pretty printing succeeds, then you'll have two top-level modules for running the test harness, and likely two #[main] functions, so you may want to verify that #[resolve_unexported] works before printing it?

This PR is obsoleted by #15847, which removes the need for #[!resolve_unexported].

Closing in favor of #15847.