Break with Value causes ICE

[CasualX]

In reply to a comment on /r/rust I tried to write a macro to simulate for ... else and this causes an ICE

I tried this code: playground

macro_rules! for_else {
    ($i:ident in $iter:expr; $body:tt else $e:expr) => {
        'outer: loop {
            for $i in $iter $body
            break 'outer $e;
        }
    };
}

fn main() {
    let result = for_else!(i in 0..10; {
        break 'outer 2.71828;
    }
    else {
        3.141592
    });
    println!("Hello, {}!", result);
}

I expected to see this happen: This was a first attempt at a for_else macro, so I'm not sure what I expected! Certainly not an ICE however

Instead, this happened:

   Compiling playground v0.0.1 (file:///playground)
error[E0426]: use of undeclared label `'outer`
  --> src/main.rs:12:15
   |
12 |         break 'outer 2.71828;
   |               ^^^^^^ undeclared label `'outer`

error: internal compiler error: /checkout/src/librustc_typeck/check/mod.rs:1984: no type for node 16: expr 2.71828 (id=16) in fcx 0x7fe29eff3670

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.20.0 (f3d6973f4 2017-08-27) running on x86_64-unknown-linux-gnu

thread 'rustc' panicked at 'Box<Any>', /checkout/src/librustc_errors/lib.rs:489:8
note: Run with `RUST_BACKTRACE=1` for a backtrace.

error: Could not compile `playground`.

To learn more, run the command again with --verbose.

Meta

Whatever's running today on the playground.

[est31]

This is fixed on nightly + beta. This is a dupe of #43162 and was likely fixed by #43745.

[CasualX]

Ah, my bad. I admittedly didn't look very far for existing issues...

The fact that this is an ICE in Stable Rust is of no concern?

[est31]

The fact that this is an ICE in Stable Rust is of no concern?

An ICE in stable Rust obviously has a higher priority but an ICE is a bug regardless of whether its in stable or nightly.