Unexpected Panic in Compiler When Referencing Function in const Initializer

[zrneely]

When I tried to compile my project, rustc panicked.

I put together a playpen that reproduces the issue (on stable, beta, or nightly, in debug or release mode), but I'm not sure where exactly the issue stems from. Side note - I was experimenting with macros for the first time, so the code is probably pretty bad anyway.

http://is.gd/EsBJsA

Here's the backtrace from my actual project:

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: 1986 }, false), last_private: LastMod(All
Public), depth: 1 }', /home/rustbuild/src/rust-buildbot/slave/stable-dist-rustc-linux/build/src/librustc/middle/def.rs:80

stack backtrace:
   1:     0x7f7c27880449 - sys::backtrace::write::hbc46dc0cfb3b9537d4r
   2:     0x7f7c27888156 - panicking::on_panic::h74d3c14d86c58ac8jrw
   3:     0x7f7c2784b462 - rt::unwind::begin_unwind_inner::h382cea404b11eb00t6v
   4:     0x7f7c2784c10c - rt::unwind::begin_unwind_fmt::h5c14cfc30901d9d274v
   5:     0x7f7c2587c710 - middle::ty::resolve_expr::h624bd395eab0f46apA6
   6:     0x7f7c259dba24 - middle::ty::expr_kind::h42a59d6cf4de6fb1vC6
   7:     0x7f7c259db7ea - middle::ty::expr_is_lval::hf75f64ec2e4f01a7sB6
   8:     0x7f7c266ff7e0 - check::check_expr_with_unifier::h16758040784423113870
   9:     0x7f7c26703595 - check::check_expr_with_unifier::h14796100913847929148
  10:     0x7f7c267232da - check::check_const_with_ty::hd1e9965599ee588c70r
  11:     0x7f7c266c17d2 - check::check_item_type::hf5c3369181584636ePn
  12:     0x7f7c266c5c02 - visit::walk_item::h932162154766316786
  13:     0x7f7c2678b652 - check_crate::closure.38028
  14:     0x7f7c26786a30 - check_crate::h22dcd95e17a2d96dXcC
  15:     0x7f7c27dc4cc8 - driver::phase_3_run_analysis_passes::h43926ceca86caa9fnGa
  16:     0x7f7c27da5dc5 - driver::compile_input::hb78754f2f33c01efQba
  17:     0x7f7c27e674d1 - run_compiler::h258d36d5501c1cdfz4b
  18:     0x7f7c27e65122 - boxed::F.FnBox<A>::call_box::h7239693171334256553
  19:     0x7f7c27e64659 - rt::unwind::try::try_fn::h14329119008520845439
  20:     0x7f7c278faac8 - rust_try_inner
  21:     0x7f7c278faab5 - rust_try
  22:     0x7f7c27e64908 - boxed::F.FnBox<A>::call_box::h17332056298259451807
  23:     0x7f7c27887041 - sys::thread::create::thread_start::h490278b5c3c0b49faqv
  24:     0x7f7c221036a9 - start_thread
  25:     0x7f7c274d8eec - clone
  26:                0x0 - <unknown>

[shepmaster]

Inlining the code so it doesn't get lost

macro_rules! get_method {
    ( $x: ident ) => {
        &Foo::$x
    };
}

struct Foo {
    a: u32
}

impl Foo {
    fn x(&mut self) {
        self.a = 5;
    }
}

const FUNC: &'static FnMut(&mut Foo) -> () = get_method!(x);

fn main() {}

[zrneely]

Update: it appears this bug is unrelated to macros, as it still occurs in the following code:

struct Foo {
    a: u32
}

impl Foo {
    fn x(&mut self) {
        self.a = 5;
    }
}

const FUNC: &'static FnMut(&mut Foo) -> () = &Foo::x;

fn main() {}

Is this intended to be possible?