Panic in cyclomatic complexity lint

[shahn]

The following reduced code produces a panic:

#![feature(plugin)]
#![plugin(clippy)]

#[allow(dead_code)]
enum Baz {
    Baz1,
    Baz2,
}

struct Test {
    t: Option<usize>,
    b: Baz,
}

fn main() {
    use Baz::*;
    let x = Test { t: Some(0), b: Baz1 };

    match x {
        Test { t: Some(a), b: Baz1 } => unreachable!(),
        Test { t: None, .. } => unreachable!(),
        Test { .. } => unreachable!(),

    }
}

[Manishearth]

$ rustc panic.rs -L target/debug
cc = 0, arms = 1
Block { stmts: [Spanned { node: stmt(19: ), span: panic.rs:16:5: 16:16 }, Spanned { node: stmt(21: let x = Test{t: Some(0), b: Baz1,};), span: panic.rs:17:5: 17:42 }], expr: Some(expr(29: match x {
    Test { t: Some(a), b: Baz1 } => {
        {
            ::std::rt::begin_unwind("internal error: entered unreachable code",
                                    { &_FILE_LINE })
        }
    }
    Test { t: None, .. } => {
        {
            ::std::rt::begin_unwind("internal error: entered unreachable code",
                                    { &_FILE_LINE })
        }
    }
    Test { .. } => {
        {
            ::std::rt::begin_unwind("internal error: entered unreachable code",
                                    { &_FILE_LINE })
        }
    }
})), id: 18, rules: DefaultBlock, span: panic.rs:15:11: 25:2 }
panic.rs:15:1: 25:2
error: internal compiler error: unexpected panic
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: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'cc = 0, arms = 1', src/cyclomatic_complexity.rs:51

cc @oli-obk

[Manishearth]

Made it stop crashing via Manishearth@dc414e6

[oli-obk]

oh... i never considered SEME code...