Warn when using `link_name` in exported items ?

[gnzlbg]

In this context:

#[link_name = "foo"]
pub static mut FOO: i32 = 4;

what does link_name do? Chances are that the user actually meant to export FOO and that

#[export_name = "foo"]
pub static mut FOO: i32 = 4;

was intended instead.

Should we warn/error about this?

cc @alexcrichton

[Centril]

cc @japaric

[alexcrichton]

Yes here #[link_name] has no effect, so it should ideally provide an unused attribute warning

[Enselic]

Since a while (I think since #73461 which added bunch of tests for this) this is now fixed.

$ rustc src/lib.rs --crate-type lib
warning: attribute should be applied to a foreign function or static
 --> src/lib.rs:1:1
  |
1 | #[link_name = "foo"]
  | ^^^^^^^^^^^^^^^^^^^^
2 | pub static mut FOO: i32 = 4;
  | ---------------------------- not a foreign function or static
  |
  = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
  = note: `#[warn(unused_attributes)]` on by default

warning: 1 warning emitted

[Enselic]

Closing since this has been fixed and tests have been added.