ICE when putting a println! after non-break infinite loop in a library's function

[allan-simon]

The minimal code to reproduce the bug

#![crate_name = "xmpp"]
#![crate_type = "lib"]

pub fn handle() {
    loop { }
    println!("we close");
}

the stack trace i got

https://gist.github.com/allan-simon/5a689088c8c46e2843d0

Note:

• it does compile correctly if we replace the function by "main" and compile it as a normal software
• it does compile correctly if we replace the println! by a let a = 42u

[lifthrasiir]

An expand-minimalized example:

#![crate_type = "lib"]

pub fn handle() {
    fail!();
    match () { // this match is mandatory, curiously.
        _ => {
            static FOO: () = (); 
        }
    }
}

Sounds like that the symbol for the static item (and possibly others) gets eliminated when the item is placed in the unreachable block. Normally this is not a bad thing, but it breaks down when the item has to be placed in the metadata anyhow.

[ghost]

Seems like this'd have been fixed in #16452.

[alexcrichton]

Flagging as needstest (one wasn't checked in with that PR)