clippy::unimplemented doesn't detect unimplemented!() with message

[ExoticMatter]

When a message is given to unimplemented!() (rust-lang/rust@f517719), the unimplemented lint doesn't detect it.

#[allow(unreachable_code)]
#[warn(clippy::unimplemented)]
fn main() {
    unimplemented!("a()"); // case 1, not detected
    unimplemented!();      // case 2
}

warning: `unimplemented` should not be present in production code
 --> src/main.rs:5:5
  |
5 |     unimplemented!();      // case 2
  |     ^^^^^^^^^^^^^^^^^
  |
note: lint level defined here
 --> src/main.rs:2:8
  |
2 | #[warn(clippy::unimplemented)]
  |        ^^^^^^^^^^^^^^^^^^^^^
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unimplemented

clippy: 29bf75c (2018-12-05)

[oli-obk]

We should move

rust-clippy/clippy_lints/src/panic_unimplemented.rs

Line 62 in f583152

impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {

to a PreExpansionPass and just check for calls to macros named unimplemented

[maxencefrenette]

I'd like to try this one !

[phansch]

@maxencefrenette awesome! Feel free to post here or open a work-in-progress PR if you have any questions.

[maxencefrenette]

Opened a WIP PR #4186 . I need some guidance.

[ebroto]

Fixed in #5811