TAIT: "open drop from non-ADT"

[kpreid]

Note: this only reproduces with cargo build (or rust-analyzer builds), not cargo check.

Code

#![feature(type_alias_impl_trait)]

pub struct Foo {
    /// This type must have nontrivial drop glue
    field: String,
}

pub type Tait = impl Sized;

pub fn ice_cold(beverage: Tait) {
    // Must destructure at least one field of `Foo`
    let Foo { field } = beverage;
    _ = field;
}

Meta

rustc --version --verbose:

rustc 1.73.0-nightly (8ca44ef9c 2023-07-10)
binary: rustc
commit-hash: 8ca44ef9caa4049d584fbbce218c219cdca33a2f
commit-date: 2023-07-10
host: x86_64-apple-darwin
release: 1.73.0-nightly
LLVM version: 16.0.5

Error output

error: internal compiler error: /rustc/8ca44ef9caa4049d584fbbce218c219cdca33a2f/compiler/rustc_mir_dataflow/src/elaborate_drops.rs:882:18: open drop from non-ADT `Tait`
  --> all-is-cubes/src/lib.rs:13:1
   |
13 | }
   | ^

Backtrace

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/8ca44ef9caa4049d584fbbce218c219cdca33a2f/compiler/rustc_errors/src/lib.rs:995:33
stack backtrace:
   0:        0x1051c8823 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h46846cd25c27bb61
   1:        0x1052283eb - core::fmt::write::h8648cc21db836a22
   2:        0x1051bcfee - std::io::Write::write_fmt::h160d847e0b1e27d8
   3:        0x1051c861a - std::sys_common::backtrace::print::hd8610d3c2137a0c7
   4:        0x1051cb925 - std::panicking::default_hook::{{closure}}::hcdf8e8a2236a8a17
   5:        0x1051cb6cf - std::panicking::default_hook::h16b4d863c7e88d79
   6:        0x1113be2de - rustc_driver_impl[b1ad63243822c31d]::install_ice_hook::{closure#0}
   7:        0x1051cc0be - std::panicking::rust_panic_with_hook::hfa873bf608bcb536
   8:        0x11232a6a7 - std[8a8250c921f3e24c]::panicking::begin_panic::<rustc_errors[5cb010bceef86e73]::ExplicitBug>::{closure#0}
   9:        0x11231ff19 - std[8a8250c921f3e24c]::sys_common::backtrace::__rust_end_short_backtrace::<std[8a8250c921f3e24c]::panicking::begin_panic<rustc_errors[5cb010bceef86e73]::ExplicitBug>::{closure#0}, !>
  10:        0x11585b8e9 - std[8a8250c921f3e24c]::panicking::begin_panic::<rustc_errors[5cb010bceef86e73]::ExplicitBug>
  11:        0x1123aa316 - <rustc_errors[5cb010bceef86e73]::HandlerInner>::span_bug::<rustc_span[8808993aab5b8002]::span_encoding::Span, alloc[b9ce9f367082534]::string::String>
  12:        0x1123aa01b - <rustc_errors[5cb010bceef86e73]::Handler>::span_bug::<rustc_span[8808993aab5b8002]::span_encoding::Span, alloc[b9ce9f367082534]::string::String>
  13:        0x11229aad9 - rustc_middle[fe685cc1f47f288d]::util::bug::opt_span_bug_fmt::<rustc_span[8808993aab5b8002]::span_encoding::Span>::{closure#0}
  14:        0x11229ab17 - rustc_middle[fe685cc1f47f288d]::ty::context::tls::with_opt::<rustc_middle[fe685cc1f47f288d]::util::bug::opt_span_bug_fmt<rustc_span[8808993aab5b8002]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  15:        0x112294f0f - rustc_middle[fe685cc1f47f288d]::ty::context::tls::with_context_opt::<rustc_middle[fe685cc1f47f288d]::ty::context::tls::with_opt<rustc_middle[fe685cc1f47f288d]::util::bug::opt_span_bug_fmt<rustc_span[8808993aab5b8002]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  16:        0x11585b99f - rustc_middle[fe685cc1f47f288d]::util::bug::span_bug_fmt::<rustc_span[8808993aab5b8002]::span_encoding::Span>
  17:        0x1123468e8 - <rustc_mir_dataflow[81a8b0cec5d58857]::elaborate_drops::DropCtxt<rustc_mir_transform[9430bfac33e5f97a]::elaborate_drops::Elaborator>>::elaborate_drop
  18:        0x1123fd6f0 - <rustc_mir_transform[9430bfac33e5f97a]::elaborate_drops::ElaborateDrops as rustc_middle[fe685cc1f47f288d]::mir::MirPass>::run_pass
  19:        0x112283586 - rustc_mir_transform[9430bfac33e5f97a]::pass_manager::run_passes_inner
  20:        0x1122ef856 - rustc_mir_transform[9430bfac33e5f97a]::run_analysis_to_runtime_passes
  21:        0x1122ef388 - rustc_mir_transform[9430bfac33e5f97a]::mir_drops_elaborated_and_const_checked
  22:        0x11279206f - rustc_query_impl[69bc60a40b6cadc3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[69bc60a40b6cadc3]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[fe685cc1f47f288d]::query::erase::Erased<[u8; 8usize]>>
  23:        0x11293c3fc - <rustc_query_impl[69bc60a40b6cadc3]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2} as core[73a651594a9ef86f]::ops::function::FnOnce<(rustc_middle[fe685cc1f47f288d]::ty::context::TyCtxt, rustc_span[8808993aab5b8002]::def_id::LocalDefId)>>::call_once
  24:        0x112754443 - rustc_query_system[9bc60c1c102f4eb6]::query::plumbing::try_execute_query::<rustc_query_impl[69bc60a40b6cadc3]::DynamicConfig<rustc_query_system[9bc60c1c102f4eb6]::query::caches::VecCache<rustc_span[8808993aab5b8002]::def_id::LocalDefId, rustc_middle[fe685cc1f47f288d]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[69bc60a40b6cadc3]::plumbing::QueryCtxt, true>
  25:        0x11291b30c - rustc_query_impl[69bc60a40b6cadc3]::query_impl::mir_drops_elaborated_and_const_checked::get_query_incr::__rust_end_short_backtrace
  26:        0x111bb22c5 - <rustc_session[4ad9f1f8d356ed64]::session::Session>::time::<(), rustc_interface[64cb6972a1b5747c]::passes::analysis::{closure#2}>
  27:        0x111c217ce - rustc_interface[64cb6972a1b5747c]::passes::analysis
  28:        0x11279254d - rustc_query_impl[69bc60a40b6cadc3]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[69bc60a40b6cadc3]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[fe685cc1f47f288d]::query::erase::Erased<[u8; 1usize]>>
  29:        0x1128ef5b9 - <rustc_query_impl[69bc60a40b6cadc3]::query_impl::analysis::dynamic_query::{closure#2} as core[73a651594a9ef86f]::ops::function::FnOnce<(rustc_middle[fe685cc1f47f288d]::ty::context::TyCtxt, ())>>::call_once
  30:        0x1126e5afd - rustc_query_system[9bc60c1c102f4eb6]::query::plumbing::try_execute_query::<rustc_query_impl[69bc60a40b6cadc3]::DynamicConfig<rustc_query_system[9bc60c1c102f4eb6]::query::caches::SingleCache<rustc_middle[fe685cc1f47f288d]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[69bc60a40b6cadc3]::plumbing::QueryCtxt, true>
  31:        0x1128aa3ad - rustc_query_impl[69bc60a40b6cadc3]::query_impl::analysis::get_query_incr::__rust_end_short_backtrace
  32:        0x111410654 - <rustc_middle[fe685cc1f47f288d]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[b1ad63243822c31d]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>>
  33:        0x1113c993c - <rustc_interface[64cb6972a1b5747c]::interface::Compiler>::enter::<rustc_driver_impl[b1ad63243822c31d]::run_compiler::{closure#1}::{closure#2}, core[73a651594a9ef86f]::result::Result<core[73a651594a9ef86f]::option::Option<rustc_interface[64cb6972a1b5747c]::queries::Linker>, rustc_span[8808993aab5b8002]::ErrorGuaranteed>>
  34:        0x111406d4b - rustc_span[8808993aab5b8002]::set_source_map::<core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>, rustc_interface[64cb6972a1b5747c]::interface::run_compiler<core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>, rustc_driver_impl[b1ad63243822c31d]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  35:        0x1113f53d4 - <scoped_tls[2b2dba828880094e]::ScopedKey<rustc_span[8808993aab5b8002]::SessionGlobals>>::set::<rustc_interface[64cb6972a1b5747c]::interface::run_compiler<core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>, rustc_driver_impl[b1ad63243822c31d]::run_compiler::{closure#1}>::{closure#0}, core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>>
  36:        0x111413157 - std[8a8250c921f3e24c]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[64cb6972a1b5747c]::util::run_in_thread_pool_with_globals<rustc_interface[64cb6972a1b5747c]::interface::run_compiler<core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>, rustc_driver_impl[b1ad63243822c31d]::run_compiler::{closure#1}>::{closure#0}, core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>>
  37:        0x111413ce9 - <<std[8a8250c921f3e24c]::thread::Builder>::spawn_unchecked_<rustc_interface[64cb6972a1b5747c]::util::run_in_thread_pool_with_globals<rustc_interface[64cb6972a1b5747c]::interface::run_compiler<core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>, rustc_driver_impl[b1ad63243822c31d]::run_compiler::{closure#1}>::{closure#0}, core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[73a651594a9ef86f]::result::Result<(), rustc_span[8808993aab5b8002]::ErrorGuaranteed>>::{closure#1} as core[73a651594a9ef86f]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  38:        0x1051d5aa9 - std::sys::unix::thread::Thread::new::thread_start::h5f50da5e904389eb
  39:     0x7ff80e7634e1 - __pthread_start

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 1.73.0-nightly (8ca44ef9c 2023-07-10) running on x86_64-apple-darwin

note: compiler flags: --crate-type lib -C opt-level=2 -C embed-bitcode=no -C debuginfo=2 -C split-debuginfo=unpacked -C debug-assertions=on -C incremental=[REDACTED]

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [mir_drops_elaborated_and_const_checked] elaborating drops for `ice_cold`
#1 [analysis] running analysis passes on this crate
end of query stack

[kpreid]

@rustbot label +A-impl-trait +F-type_alias_impl_trait