ICE: compiler/rustc_typeck/src/check/check.rs:108:25: Item being checked wasn't a function/closure:

[chengniansun]

Code

trait Tr {
    extern "rust-call" fn dm4() {}
}

Meta

rustc --version --verbose:

rustc 1.50.0-nightly (5be3f9f10 2020-12-03)
binary: rustc
commit-hash: 5be3f9f10e9fd59ea03816840a6051413fbdefae
commit-date: 2020-12-03
host: x86_64-unknown-linux-gnu
release: 1.50.0-nightly

Error output

error[E0658]: rust-call ABI is subject to change
 --> perses_node_priority_with_dfs_delta_reduced_mutant.rs:2:12
  |
2 |     extern "rust-call" fn dm4() {}
  |            ^^^^^^^^^^^
  |
  = note: see issue #29625 <https://github.com/rust-lang/rust/issues/29625> for more information
  = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable

error[E0601]: `main` function not found in crate `perses_node_priority_with_dfs_delta_reduced_mutant`
 --> perses_node_priority_with_dfs_delta_reduced_mutant.rs:1:1
  |
1 | / trait Tr {
2 | |     extern "rust-call" fn dm4() {}
3 | | }
  | |_^ consider adding a `main` function to `perses_node_priority_with_dfs_delta_reduced_mutant.rs`

error: internal compiler error: compiler/rustc_typeck/src/check/check.rs:108:25: Item being checked wasn't a function/closure: TraitItem(TraitItem { ident: dm4#0, hir_id: HirId { owner: DefId(0:4 ~ perses_node_priority_with_dfs_delta_reduced_mutant[317d]::Tr::dm4), local_id: 0 }, attrs: [], generics: Generics { params: [], where_clause: WhereClause { predicates: [], span: perses_node_priority_with_dfs_delta_reduced_mutant.rs:2:32: 2:32 (#0) }, span: perses_node_priority_with_dfs_delta_reduced_mutant.rs:2:30: 2:30 (#0) }, kind: Fn(FnSig { header: FnHeader { unsafety: Normal, constness: NotConst, asyncness: NotAsync, abi: RustCall }, decl: FnDecl { inputs: [], output: DefaultReturn(perses_node_priority_with_dfs_delta_reduced_mutant.rs:2:33: 2:33 (#0)), c_variadic: false, implicit_self: None }, span: perses_node_priority_with_dfs_delta_reduced_mutant.rs:2:5: 2:32 (#0) }, Provided(BodyId { hir_id: HirId { owner: DefId(0:4 ~ perses_node_priority_with_dfs_delta_reduced_mutant[317d]::Tr::dm4), local_id: 2 } })), span: perses_node_priority_with_dfs_delta_reduced_mutant.rs:2:5: 2:35 (#0) })

thread 'rustc' panicked at 'Box<Any>', compiler/rustc_errors/src/lib.rs:958:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.50.0-nightly (5be3f9f10 2020-12-03) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [typeck] type-checking `Tr::dm4`
#1 [typeck_item_bodies] type-checking all item bodies
end of query stack
error: aborting due to 3 previous errors

Some errors have detailed explanations: E0601, E0658.
For more information about an error, try `rustc --explain E0601`.

Backtrace

thread 'rustc' panicked at 'Box<Any>', compiler/rustc_errors/src/lib.rs:958:9
stack backtrace:
   0: std::panicking::begin_panic
   1: rustc_errors::HandlerInner::bug
   2: rustc_errors::Handler::bug
   3: rustc_middle::util::bug::opt_span_bug_fmt::{{closure}}
   4: rustc_middle::ty::context::tls::with_opt::{{closure}}
   5: rustc_middle::ty::context::tls::with_opt
   6: rustc_middle::util::bug::opt_span_bug_fmt
   7: rustc_middle::util::bug::bug_fmt
   8: rustc_typeck::check::check::check_fn
   9: rustc_infer::infer::InferCtxtBuilder::enter
  10: rustc_typeck::check::typeck
  11: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck>::compute
  12: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task
  13: rustc_data_structures::stack::ensure_sufficient_stack
  14: rustc_query_system::query::plumbing::get_query_impl
  15: rustc_query_system::query::plumbing::ensure_query_impl
  16: rustc_typeck::check::typeck_item_bodies
  17: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::typeck_item_bodies>::compute
  18: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task
  19: rustc_data_structures::stack::ensure_sufficient_stack
  20: rustc_query_system::query::plumbing::get_query_impl
  21: rustc_typeck::check_crate
  22: rustc_interface::passes::analysis
  23: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::analysis>::compute
  24: rustc_query_system::dep_graph::graph::DepGraph<K>::with_eval_always_task
  25: rustc_data_structures::stack::ensure_sufficient_stack
  26: rustc_query_system::query::plumbing::get_query_impl
  27: rustc_interface::passes::QueryContext::enter
  28: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  29: rustc_span::with_source_map
  30: scoped_tls::ScopedKey<T>::set
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[camelid]

Duplicate of #79669.