Associated types Order can cause ICE

[mitsuhiko]

Not sure how to properly describe the bug, but this causes an ICE:

#![feature(associated_types)]

struct SimulationInfo;

impl SimulationInfo {
    fn add_state<T: HasState>(&mut self, op: || -> <T as HasState>::State)
        -> Option<&mut <T as HasState>::State> {
        None
    }
}

trait HasState {
    type State;
}

Whereas this compiles:

#![feature(associated_types)]

struct SimulationInfo;

trait HasState {
    type State;
}

impl SimulationInfo {
    fn add_state<T: HasState>(&mut self, op: || -> <T as HasState>::State)
        -> Option<&mut <T as HasState>::State> {
        None
    }
}

Failure:

error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'No def'n found for DefId { krate: 0, node: 33 } in tcx.impl_or_trait_items', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/librustc/middle/ty.rs:4066

stack backtrace:
   1:        0x10d45a619 - rt::backtrace::imp::write::h03fee16d4a0b6b41moq
   2:        0x10d45d85c - failure::on_fail::h3e0f6b3c6c4bbcc3VEq
   3:        0x10d6bcf05 - unwind::begin_unwind_inner::h6c7f4532e72658d7SJd
   4:        0x10d6bcb9f - unwind::begin_unwind_fmt::h9863b25c438d6314kHd
   5:        0x10a408d50 - middle::ty::impl_or_trait_item::h8676078de6338b03J2J
   6:        0x10a7fe51e - middle::typeck::collect::convert_methods::ty_of_method::h1b65fc29f839dd39kEi
   7:        0x10a7a4b84 - middle::typeck::collect::convert::hf5d19782a9342fbfL7i
   8:        0x10a79c993 - middle::typeck::collect::collect_item_types::h2af040048993f98298h
   9:        0x10a1bb556 - util::common::time::h11920059333862041717
  10:        0x10a965478 - middle::typeck::check_crate::h50fcc5c8b39993f4LVn
  11:        0x10a9cdbcf - driver::driver::phase_3_run_analysis_passes::h1425a4ca465c7b097DA
  12:        0x10a9c82b8 - driver::driver::compile_input::h60bc42ef7fabbfd4SkA
  13:        0x10aa45ca8 - driver::run_compiler::h4031243f49082a9fw7D
  14:        0x10aa43ece - driver::run::closure.145349
  15:        0x10a1d381b - task::TaskBuilder<S>::try_future::closure.103709
  16:        0x10a1d3713 - task::TaskBuilder<S>::spawn_internal::closure.103680
  17:        0x10a15398d - task::NativeSpawner.Spawner::spawn::closure.8526
  18:        0x10d72320c - rust_try_inner
  19:        0x10d7231f6 - rust_try
  20:        0x10d6ba677 - unwind::try::hab84862d0081b274cyd
  21:        0x10d6ba50c - task::Task::run::h39093ecd59554b49ZJc
  22:        0x10a1537b3 - task::NativeSpawner.Spawner::spawn::closure.8463
  23:        0x10d6bbd37 - thread::thread_start::h589be8c0a398d299e5c
  24:     0x7fff9260c2fc - _pthread_body
  25:     0x7fff9260c279 - _pthread_body

[ghost]

cc https://github.com/rust-lang/rust/issues/18389

[huonw]

Simpler example with the same error message:

#![feature(associated_types)]

fn add_state(op: <int as HasState>::State) {}

trait HasState {
    type State;
}

[kstep]

I just stubled upon this bug (or very similar to this one) with latest nightly build (rustc 0.13.0-nightly (5ba610265 2014-12-25 18:01:36 +0000):

ERROR:rbml::reader: failed to find block with tag 1
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
thread 'rustc' panicked at 'explicit panic', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/librbml/lib.rs:253
stack backtrace:
   1:     0x7fe80c6489f0 - sys::backtrace::write::hce8e882332e546a7JGt
   2:     0x7fe80c669820 - failure::on_fail::h588dafd90e82b74cj7z
   3:     0x7fe80c5d9ff0 - rt::unwind::begin_unwind_inner::h80ab16382fe3341ajLz
   4:     0x7fe8063243e0 - rt::unwind::begin_unwind::h1631746081972254121
   5:     0x7fe806322b60 - reader::get_doc::h2922d64c0e3fa9de0La
   6:     0x7fe80a99e5c0 - metadata::decoder::item_name::h342ac23f34c6fc45aDg
   7:     0x7fe80a9aa970 - metadata::decoder::get_trait_item_name_and_kind::hc85cab121b9bcebaAfh
   8:     0x7fe80a9ca310 - metadata::csearch::get_trait_item_name_and_kind::h5e523f8f26b802252yj
   9:     0x7fe80b84bff0 - Resolver<$u{27}a$GT$::build_reduced_graph_for_external_crate_def::he6103e3a99036d22gTc
  10:     0x7fe80b8517d0 - Resolver<$u{27}a$GT$::populate_external_module::unboxed_closure.13677
  11:     0x7fe80b81c260 - Resolver<$u{27}a$GT$::populate_module_if_necessary::h13429a2c5fef87d3i7c
  12:     0x7fe80b8598e0 - Resolver<$u{27}a$GT$::resolve_single_import::h617f6a0cbefe0c03zzd
  13:     0x7fe80b854d40 - Resolver<$u{27}a$GT$::resolve_imports_for_module::h21760343ab6f5d103ld
  14:     0x7fe80b853f90 - Resolver<$u{27}a$GT$::resolve_imports_for_module_subtree::hcf21ceb4110b82efjjd
  15:     0x7fe80b889db0 - resolve_crate::h5275b8fb523748b5Zxi
  16:     0x7fe80cba6d70 - driver::phase_3_run_analysis_passes::hdab79b3989f72249Jta
  17:     0x7fe80cb890b0 - driver::compile_input::h136bd835ef2474a0wba
  18:     0x7fe80cd55df0 - thunk::F.Invoke<A,$u{20}R$GT$::invoke::h3869597535200102526
  19:     0x7fe80cd54500 - rt::unwind::try::try_fn::h14290739184301814176
  20:     0x7fe80c6ce4e0 - rust_try_inner
  21:     0x7fe80c6ce4d0 - rust_try
  22:     0x7fe80cd54810 - thunk::F.Invoke<A,$u{20}R$GT$::invoke::h14740898037462295535
  23:     0x7fe80c658d40 - sys::thread::thread_start::h208082a168773e0ahFw
  24:     0x7fe806e87250 - start_thread
  25:     0x7fe80c28e589 - clone
  26:                0x0 - <unknown>
Could not compile `pb`.
Caused by:
  Process didn't exit successfully: `rustc /home/kstep/git/rust-pb/src/bin/trans-done-pb.rs --crate-name trans-done-pb --crate-type bin -g --out-dir /home/kste
p/git/rust-pb/target --emit=dep-info,link -L /home/kstep/git/rust-pb/target -L /home/kstep/git/rust-pb/target/deps --extern url=/home/kstep/git/rust-pb/target/
deps/liburl-d8534f0d463d0fed.rlib --extern http=/home/kstep/git/rust-pb/target/deps/libhttp-cdd1854d276fc158.rlib --extern rustc-serialize=/home/kstep/git/rust
-pb/target/deps/librustc-serialize-bd3e38505da47309.rlib --extern pb=/home/kstep/git/rust-pb/target/libpb-6571e72a68dae90d.rlib -L /usr/lib -L /home/kstep/git/
rust-pb/target/build/time-2f77139443a72f65/out` (status=101)

I have the following code in one of my modules:

pub trait PbMsg {
  type Obj;
}

// ....

impl PushMsg for PbMsg {
  type Obj = super::objects::Push;
}
// ...and a lot of very similar definitions

When I comment out this code, my module compiles OK.

If this is another bug, I will post it separately.