ICE when attempting to explicitly type function pointer variable

[maghoff]

I get an internal compiler error on the input detailed below.

I tried this code:

struct B;

impl B {
    fn func(&self) { }
}

fn main() {
    let x:&fn(&B) = &B::func;
}

I expected to see this happen: Maybe it should work like let x = &B::func, but I'm guessing that I have some error here. I get an error message when I try a variant of the above;

fn main() {
    let y = &B::func;
    let z:&fn(&B) = y;
}

This gives me the compile time error:

bug.rs:10:18: 10:19 error: mismatched types:
 expected `&fn(&B)`,
    found `&fn(&B) {B::func}`
(expected fn pointer,
    found fn item) [E0308]
bug.rs:10       let z:&fn(&B) = y;
                                ^
error: aborting due to previous error

Instead, this happened:

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 'path not fully resolved: PathResolution { base_def: DefTy(DefId { krate: 0, node: 4 }, false), last_private: LastMod(AllPublic), depth: 1 }', /build/buildd/rust-nightly-201504110408~93f7fe3~utopic/src/librustc/middle/def.rs:80

Meta

rustc --version --verbose:

rustc 1.0.0-dev (built 2015-04-11)
binary: rustc
commit-hash: unknown
commit-date: unknown
build-date: 2015-04-11
host: x86_64-unknown-linux-gnu
release: 1.0.0-dev

From the rust-nightly package here: https://launchpad.net/~hansjorg/+archive/ubuntu/rust

Backtrace:

Running RUST_BACKTRACE=1 rustc bug.rs gives me only this output:

Illegal instruction

[maghoff]

I attempted a small search for similar issues, but didn't quite know what to look for. In any event, I was unable to identify a duplicate :)

I am currently trying to build rustc from source to see if I will be able to get a backtrace that way.

[maghoff]

I have now been able to try with a locally compiled rustc:

rustc --version --verbose:

rustc 1.0.0-dev (3a8275397 2015-04-11) (built 2015-04-11)
binary: rustc
commit-hash: 3a8275397a156b17331e16393e5e1ba89ab4de3f
commit-date: 2015-04-11
build-date: 2015-04-11
host: x86_64-unknown-linux-gnu
release: 1.0.0-dev

Backtrace:

stack backtrace:
   1:     0x7fe588440779 - sys::backtrace::write::h1fb912b6242676e13JC
   2:     0x7fe588465067 - panicking::on_panic::h49b58f19dee2b6499aJ
   3:     0x7fe5883aefb2 - rt::unwind::begin_unwind_inner::h954a8c2d8b458b8ehQI
   4:     0x7fe5883af27f - rt::unwind::begin_unwind_fmt::h8142be88e287f416VOI
   5:     0x7fe5863bcfe0 - middle::ty::resolve_expr::h468519011c7f5a2dsB6
   6:     0x7fe58650e2b1 - middle::ty::expr_kind::h13d00213be0997d6yD6
   7:     0x7fe58650e07a - middle::ty::expr_is_lval::he8576d1b1ffb6fb6vC6
   8:     0x7fe587245c60 - check::check_expr_with_unifier::h1234167007494092036
   9:     0x7fe58726c89b - check::check_decl_local::h66808f8a0a45231fHjs
  10:     0x7fe5872125b1 - check::check_block_with_expected::h8460ca5f594c8570Nps
  11:     0x7fe5871f6196 - check::check_fn::hd5196d54a6852698Abo
  12:     0x7fe58720df97 - check::check_bare_fn::h0073eb2d0e87712990n
  13:     0x7fe587207b58 - check::check_item::hef34ffea35346370Ujo
  14:     0x7fe5872cefb6 - check_crate::closure.36498
  15:     0x7fe5872ca3f0 - check_crate::h679eb3dc01c34e66zxC
  16:     0x7fe588ab8938 - driver::phase_3_run_analysis_passes::h7b112f16caf4f0fcpGa
  17:     0x7fe588a99a05 - driver::compile_input::hb07383d8b05653e9Qba
  18:     0x7fe588b586e1 - run_compiler::hd11be756ecff4a4dL4b
  19:     0x7fe588b56332 - boxed::F.FnBox<A>::call_box::h9743051768958258733
  20:     0x7fe588b55869 - rt::unwind::try::try_fn::h3770862294174962809
  21:     0x7fe5884e55f8 - rust_try_inner
  22:     0x7fe5884e55e5 - rust_try
  23:     0x7fe588b55b18 - boxed::F.FnBox<A>::call_box::h17316511360530184554
  24:     0x7fe5884529e1 - sys::thread::create::thread_start::h14fabfa97526362frLH
  25:     0x7fe582ddd0a4 - start_thread
  26:     0x7fe588018cfc - __clone
  27:                0x0 - <unknown>

[maghoff]

This issue may be related to a similar issue I also bumped into: https://github.com/rust-lang/rust/issues/24327