Empty super::{} and self::{} imports gives an error.

[JeanCASPAR]

Code

mod foo {
    use super::{};
}

Current output

error[E0432]: unresolved import `super`
 --> src/lib.rs:2:9
  |
2 |     use super::{};
  |         ^^^^^^^^^ no `super` in the root

warning: unused import: `super::{}`
 --> src/lib.rs:2:9
  |
2 |     use super::{};
  |         ^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

Desired output

warning: unused import: `super::{}`
 --> src/lib.rs:2:9
  |
2 |     use super::{};
  |         ^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

Rationale and extra context

The same problem exists with an empty use self::{}; import.

There is no reason for empty self and super imports gives an error when empty crate::{}, some_crate::{} and path::to::a::module::{} imports are perfectly valid. The compiler should of course emit a warning.

If they should be forbidden nonetheless, the error message could be clearer.

It should be noted that the following code if perfectly valid:

mod bar {}
mod foo {
    use super::bar::{};
}
use self::bar::{};

I obtained such a code with empty super imports with macros.

Other cases

No response

Rust Version

rustc 1.75.0 (82e1608df 2023-12-21)
binary: rustc
commit-hash: 82e1608dfa6e0b5569232559e3d385fea5a93112
commit-date: 2023-12-21
host: x86_64-unknown-linux-gnu
release: 1.75.0
LLVM version: 17.0.6

Anything else?

No response

[Noratrieb]

@petrochenkov

[petrochenkov]

The relevant code is messy, I have a bunch of similar issues assigned to me (#29036, #35612, #37156, #39401) but never got to fixing them due to low priority.

[mj10021]

Is this a good issue if I'll need some help/mentoring or would that be too annoying?