Closed
Description
Affects stable and nightly, with and without #![feature(nll)].
use std::marker::PhantomData;
trait DistributedIterator {
fn reduce(self)
where
Self: Sized,
{
unreachable!()
}
}
trait DistributedIteratorMulti<Source> {
type Item;
}
struct Connect<I>(PhantomData<fn(I)>);
impl<I: for<'a> DistributedIteratorMulti<&'a ()>> DistributedIterator for Connect<I> where {}
struct Cloned<Source>(PhantomData<fn(Source)>);
impl<'a, Source> DistributedIteratorMulti<&'a Source> for Cloned<&'a Source> {
type Item = ();
}
struct Map<I, F> {
i: I,
f: F,
}
impl<I: DistributedIteratorMulti<Source>, F, Source> DistributedIteratorMulti<Source> for Map<I, F>
where
F: A<<I as DistributedIteratorMulti<Source>>::Item>,
{
type Item = ();
}
trait A<B> {}
struct X;
impl A<()> for X {}
fn multi<I>(_reducer: I)
where
I: for<'a> DistributedIteratorMulti<&'a ()>,
{
DistributedIterator::reduce(Connect::<I>(PhantomData))
}
fn main() {
multi(Map {
i: Cloned(PhantomData),
f: X,
});
}thread 'main' panicked at 'leak-check would have us replace ReErased with BrNamed(crate0:DefIndex(1:14), 'a)', librustc/infer/higher_ranked/mod.rs:507:21
stack backtrace:
0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
1: std::sys_common::backtrace::_print
at libstd/sys_common/backtrace.rs:71
2: std::panicking::default_hook::{{closure}}
at libstd/sys_common/backtrace.rs:59
at libstd/panicking.rs:211
3: std::panicking::default_hook
at libstd/panicking.rs:227
4: rustc::util::common::panic_hook
5: std::panicking::rust_panic_with_hook
at libstd/panicking.rs:480
6: std::panicking::continue_panic_fmt
at libstd/panicking.rs:390
7: std::panicking::begin_panic_fmt
at libstd/panicking.rs:345
8: rustc::infer::higher_ranked::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::plug_leaks::{{closure}}
9: rustc::ty::fold::TypeFolder::fold_ty
10: <smallvec::SmallVec<A> as core::iter::traits::FromIterator<<A as smallvec::Array>::Item>>::from_iter
11: rustc::ty::fold::TypeFoldable::fold_with
12: rustc::ty::fold::TypeFolder::fold_ty
13: <smallvec::SmallVec<A> as core::iter::traits::FromIterator<<A as smallvec::Array>::Item>>::from_iter
14: rustc::ty::fold::TypeFoldable::fold_with
15: rustc::ty::fold::TypeFoldable::fold_with
16: <core::iter::Map<I, F> as core::iter::iterator::Iterator>::fold
17: rustc::ty::fold::TypeFoldable::fold_with
18: rustc::infer::higher_ranked::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::plug_leaks
19: rustc::traits::select::SelectionContext::impl_or_trait_obligations
20: rustc::traits::select::SelectionContext::vtable_impl
21: rustc::infer::InferCtxt::in_snapshot
22: rustc::traits::select::SelectionContext::confirm_candidate
23: rustc::infer::InferCtxt::probe
24: rustc::traits::select::SelectionContext::evaluate_stack
25: rustc::dep_graph::graph::DepGraph::with_anon_task
26: rustc::traits::select::SelectionContext::evaluate_predicate_recursively
27: rustc::traits::select::SelectionContext::evaluate_obligation_recursively
28: rustc::ty::context::tls::with_related_context
29: rustc::infer::InferCtxtBuilder::enter_with_canonical
30: rustc_traits::evaluate_obligation::evaluate_obligation
31: rustc::ty::query::__query_compute::evaluate_obligation
32: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::evaluate_obligation<'tcx>>::compute
33: rustc::dep_graph::graph::DepGraph::with_task_impl
34: rustc::ty::context::tls::with_related_context
35: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
36: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query
37: rustc::traits::query::evaluate_obligation::<impl rustc::infer::InferCtxt<'cx, 'gcx, 'tcx>>::evaluate_obligation
38: rustc::traits::query::evaluate_obligation::<impl rustc::infer::InferCtxt<'cx, 'gcx, 'tcx>>::evaluate_obligation_no_overflow
39: <rustc_data_structures::obligation_forest::ObligationForest<O>>::process_obligations
40: <rustc::traits::fulfill::FulfillmentContext<'tcx> as rustc::traits::engine::TraitEngine<'tcx>>::select_where_possible
41: <rustc::traits::fulfill::FulfillmentContext<'tcx> as rustc::traits::engine::TraitEngine<'tcx>>::select_all_or_error
42: rustc::traits::codegen::<impl rustc::infer::InferCtxt<'a, 'gcx, 'tcx>>::drain_fulfillment_cx_or_panic
43: rustc::ty::context::tls::with_related_context
44: rustc::infer::InferCtxtBuilder::enter
45: rustc::traits::codegen::codegen_fulfill_obligation
46: rustc::ty::query::__query_compute::codegen_fulfill_obligation
47: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::codegen_fulfill_obligation<'tcx>>::compute
48: rustc::dep_graph::graph::DepGraph::with_task_impl
49: rustc::ty::context::tls::with_related_context
50: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
51: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query
52: rustc::ty::instance::Instance::resolve
53: rustc_mir::monomorphize::collector::visit_fn_use
54: <rustc_mir::monomorphize::collector::MirNeighborCollector<'a, 'tcx> as rustc::mir::visit::Visitor<'tcx>>::visit_terminator_kind
55: rustc_mir::monomorphize::collector::collect_items_rec
56: rustc_mir::monomorphize::collector::collect_items_rec
57: rustc_mir::monomorphize::collector::collect_crate_mono_items::{{closure}}
58: rustc::util::common::time
59: rustc_mir::monomorphize::collector::collect_crate_mono_items
60: rustc::util::common::time
61: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items
62: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors<'tcx> for rustc::ty::query::queries::collect_and_partition_mono_items<'tcx>>::compute
63: rustc::dep_graph::graph::DepGraph::with_task_impl
64: rustc::ty::context::tls::with_related_context
65: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::force_query_with_job
66: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt<'a, 'gcx, 'tcx>>::get_query
67: rustc_codegen_llvm::base::codegen_crate
68: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_utils::codegen_backend::CodegenBackend>::codegen_crate
69: rustc::util::common::time
70: rustc_driver::driver::phase_4_codegen
71: rustc_driver::driver::compile_input::{{closure}}
72: rustc::ty::context::tls::enter_context
73: <std::thread::local::LocalKey<T>>::with
74: rustc::ty::context::TyCtxt::create_and_enter
75: rustc_driver::driver::compile_input
76: rustc_driver::run_compiler_with_pool
77: rustc_driver::driver::spawn_thread_pool
78: rustc_driver::run_compiler
79: <scoped_tls::ScopedKey<T>>::set
80: syntax::with_globals
81: __rust_maybe_catch_panic
at libpanic_unwind/lib.rs:102
82: rustc_driver::run
83: rustc_driver::main
84: std::rt::lang_start::{{closure}}
85: std::panicking::try::do_call
at libstd/rt.rs:59
at libstd/panicking.rs:310
86: __rust_maybe_catch_panic
at libpanic_unwind/lib.rs:102
87: std::rt::lang_start_internal
at libstd/panicking.rs:289
at libstd/panic.rs:398
at libstd/rt.rs:58
88: main
89: __libc_start_main
90: <unknown>
query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `for<'a> Map<Cloned<&()>, X>: DistributedIteratorMulti<&'a ()>`
#1 [codegen_fulfill_obligation] checking if `DistributedIterator` fulfills its obligations
#2 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
error: internal compiler error: unexpected panic
note: rustc 1.32.0-nightly (13dab66a6 2018-11-05) running on x86_64-unknown-linux-gnu
note: compiler flags: -C codegen-units=1 -C debuginfo=2 --crate-type bin