ICE: broken mir in AsyncDropGlue, place has deref as a later projection (it is only permitted as the first projection)

[matthiaskrgr]

Code

//@ compile-flags --edition=2021 --crate-type lib -Zvalidate-mir
#![feature(async_drop)]
use std::{future::AsyncDrop, pin::Pin};
struct a {
    b: usize,
}
struct c {
    d: a,
    e: a,
    f: a,
}
impl c {
    fn i(b: usize) -> Self {
        let d = a::i(b);
        let e = a::i(1);
        let f = a::i(2);
        c { d, e, f }
    }
}
impl a {
    fn i(b: usize) -> Self {
        let g = a { b };
        g
    }
}
impl Drop for a {
    fn drop(&mut self) {}
}
impl AsyncDrop for a {
    async fn drop(self: Pin<&mut Self>) {}
}
async fn bar(h: usize) {
    c::i(h);
}

Meta

rustc --version --verbose:

rustc 1.89.0-nightly (8405332bd 2025-05-12)
binary: rustc
commit-hash: 8405332bdf09b153e475f83b8b8ebf8d4e8eb81f
commit-date: 2025-05-12
host: x86_64-unknown-linux-gnu
release: 1.89.0-nightly
LLVM version: 20.1.4

Error output

<output>

Backtrace

thread 'rustc' panicked at compiler/rustc_mir_transform/src/validate.rs:80:25:
broken MIR in AsyncDropGlue(DefId(2:15267 ~ core[844c]::future::async_drop::async_drop_in_place::{closure#0}), Coroutine(DefId(2:15267 ~ core[844c]::future::async_drop::async_drop_in_place::{closure#0}), [c, (), std::future::ResumeTy, (), (), CoroutineWitness(DefId(2:15267 ~ core[844c]::future::async_drop::async_drop_in_place::{closure#0}), [c]), (*mut c,)])) (after pass MentionedItems) at bb9[0]:
place (*(_6.0: &mut a)) has deref as a later projection (it is only permitted as the first projection)
stack backtrace:
   0:     0x7da4d31596c3 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hee27e289fa80eeb0
   1:     0x7da4d3805987 - core::fmt::write::hcb7a95a553d927d7
   2:     0x7da4d48d3411 - std::io::Write::write_fmt::h5f19ce2ac2f30773
   3:     0x7da4d3159522 - std::sys::backtrace::BacktraceLock::print::h967e6c26dabf5676
   4:     0x7da4d315d11a - std::panicking::default_hook::{{closure}}::h4c9e43e4d632c501
   5:     0x7da4d315cc9f - std::panicking::default_hook::ha3c41200eaedb148
   6:     0x7da4d218ac13 - std[a3033ab4cf040dbc]::panicking::update_hook::<alloc[2b9f1e9988cc0e0]::boxed::Box<rustc_driver_impl[2b29d548aa47efe8]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x7da4d315d993 - std::panicking::rust_panic_with_hook::h614c9e3cb602169a
   8:     0x7da4d315d68a - std::panicking::begin_panic_handler::{{closure}}::h7175c42c4098b33c
   9:     0x7da4d3159b89 - std::sys::backtrace::__rust_end_short_backtrace::hb28ab4ef577ce3dd
  10:     0x7da4d315d34d - __rustc[9e838b297ad6583e]::rust_begin_unwind
  11:     0x7da4cfa86220 - core::panicking::panic_fmt::hee3e8e41a6e23382
  12:     0x7da4d0d38bd2 - <rustc_mir_transform[86a227439405b463]::validate::CfgChecker>::fail::<alloc[2b9f1e9988cc0e0]::string::String>
  13:     0x7da4d493af6b - <rustc_mir_transform[86a227439405b463]::validate::Validator as rustc_mir_transform[86a227439405b463]::pass_manager::MirPass>::run_pass
  14:     0x7da4d19db165 - rustc_mir_transform[86a227439405b463]::pass_manager::validate_body
  15:     0x7da4d3803d91 - rustc_mir_transform[86a227439405b463]::pass_manager::run_passes_inner
  16:     0x7da4d4345d85 - rustc_mir_transform[86a227439405b463]::shim::make_shim
  17:     0x7da4d4343cef - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::mir_shims::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 8usize]>>
  18:     0x7da4d4343ca3 - <rustc_query_impl[c99fb05ce5425a5b]::query_impl::mir_shims::dynamic_query::{closure#2} as core[844c48195e089da5]::ops::function::FnOnce<(rustc_middle[c35c93541fbaf6fb]::ty::context::TyCtxt, rustc_middle[c35c93541fbaf6fb]::ty::instance::InstanceKind)>>::call_once
  19:     0x7da4d40115c8 - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::DefaultCache<rustc_middle[c35c93541fbaf6fb]::ty::instance::InstanceKind, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  20:     0x7da4d40112e6 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::mir_shims::get_query_non_incr::__rust_end_short_backtrace
  21:     0x7da4d283af24 - <rustc_middle[c35c93541fbaf6fb]::ty::context::TyCtxt>::coroutine_layout
  22:     0x7da4d3f2fc5b - rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached
  23:     0x7da4d3f22b4e - rustc_ty_utils[c2f95faedb959599]::layout::layout_of
  24:     0x7da4d3f22aaa - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>
  25:     0x7da4d3f2189c - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::DefaultCache<rustc_middle[c35c93541fbaf6fb]::ty::PseudoCanonicalInput<rustc_middle[c35c93541fbaf6fb]::ty::Ty>, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  26:     0x7da4d3f214e7 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::get_query_non_incr::__rust_end_short_backtrace
  27:     0x7da4d3f2039a - <core[844c48195e089da5]::iter::adapters::GenericShunt<core[844c48195e089da5]::iter::adapters::by_ref_sized::ByRefSized<core[844c48195e089da5]::iter::adapters::map::Map<core[844c48195e089da5]::slice::iter::Iter<rustc_middle[c35c93541fbaf6fb]::ty::VariantDef>, rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached::{closure#20}>>, core[844c48195e089da5]::result::Result<core[844c48195e089da5]::convert::Infallible, &rustc_middle[c35c93541fbaf6fb]::ty::layout::LayoutError>> as core[844c48195e089da5]::iter::traits::iterator::Iterator>::next
  28:     0x7da4d3f27e44 - rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached
  29:     0x7da4d3f22b4e - rustc_ty_utils[c2f95faedb959599]::layout::layout_of
  30:     0x7da4d3f22aaa - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>
  31:     0x7da4d3f2189c - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::DefaultCache<rustc_middle[c35c93541fbaf6fb]::ty::PseudoCanonicalInput<rustc_middle[c35c93541fbaf6fb]::ty::Ty>, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  32:     0x7da4d3f214e7 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::get_query_non_incr::__rust_end_short_backtrace
  33:     0x7da4d3f2074a - <core[844c48195e089da5]::iter::adapters::GenericShunt<core[844c48195e089da5]::iter::adapters::by_ref_sized::ByRefSized<core[844c48195e089da5]::iter::adapters::map::Map<core[844c48195e089da5]::slice::iter::Iter<rustc_middle[c35c93541fbaf6fb]::ty::VariantDef>, rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached::{closure#20}>>, core[844c48195e089da5]::result::Result<core[844c48195e089da5]::convert::Infallible, &rustc_middle[c35c93541fbaf6fb]::ty::layout::LayoutError>> as core[844c48195e089da5]::iter::traits::iterator::Iterator>::next
  34:     0x7da4d3f27e44 - rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached
  35:     0x7da4d3f22b4e - rustc_ty_utils[c2f95faedb959599]::layout::layout_of
  36:     0x7da4d3f22aaa - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>
  37:     0x7da4d3f2189c - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::DefaultCache<rustc_middle[c35c93541fbaf6fb]::ty::PseudoCanonicalInput<rustc_middle[c35c93541fbaf6fb]::ty::Ty>, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  38:     0x7da4d3f214e7 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::get_query_non_incr::__rust_end_short_backtrace
  39:     0x7da4d3f235c0 - rustc_ty_utils[c2f95faedb959599]::layout::layout_of
  40:     0x7da4d3f22aaa - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>
  41:     0x7da4d3f2189c - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::DefaultCache<rustc_middle[c35c93541fbaf6fb]::ty::PseudoCanonicalInput<rustc_middle[c35c93541fbaf6fb]::ty::Ty>, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  42:     0x7da4d3f214e7 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::get_query_non_incr::__rust_end_short_backtrace
  43:     0x7da4d3f33349 - <rustc_middle[c35c93541fbaf6fb]::ty::layout::LayoutCx as rustc_middle[c35c93541fbaf6fb]::ty::layout::LayoutOf>::spanned_layout_of
  44:     0x7da4d30c4e30 - <core[844c48195e089da5]::iter::adapters::GenericShunt<core[844c48195e089da5]::iter::adapters::by_ref_sized::ByRefSized<core[844c48195e089da5]::iter::adapters::map::Map<core[844c48195e089da5]::slice::iter::Iter<rustc_middle[c35c93541fbaf6fb]::mir::query::CoroutineSavedTy>, rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached::{closure#12}>>, core[844c48195e089da5]::result::Result<core[844c48195e089da5]::convert::Infallible, &rustc_middle[c35c93541fbaf6fb]::ty::layout::LayoutError>> as core[844c48195e089da5]::iter::traits::iterator::Iterator>::next
  45:     0x7da4d30aec1a - core[844c48195e089da5]::iter::adapters::try_process::<core[844c48195e089da5]::iter::adapters::by_ref_sized::ByRefSized<core[844c48195e089da5]::iter::adapters::map::Map<core[844c48195e089da5]::slice::iter::Iter<rustc_middle[c35c93541fbaf6fb]::mir::query::CoroutineSavedTy>, rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached::{closure#12}>>, rustc_abi[a261153e5dfc86cc]::layout::ty::TyAndLayout<rustc_middle[c35c93541fbaf6fb]::ty::Ty>, core[844c48195e089da5]::result::Result<core[844c48195e089da5]::convert::Infallible, &rustc_middle[c35c93541fbaf6fb]::ty::layout::LayoutError>, <core[844c48195e089da5]::iter::adapters::map::Map<core[844c48195e089da5]::slice::iter::Iter<rustc_middle[c35c93541fbaf6fb]::mir::query::CoroutineSavedTy>, rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached::{closure#12}> as core[844c48195e089da5]::iter::traits::iterator::Iterator>::try_collect<rustc_index[731be7b9208c99a6]::vec::IndexVec<rustc_middle[c35c93541fbaf6fb]::mir::query::CoroutineSavedLocal, rustc_abi[a261153e5dfc86cc]::layout::ty::TyAndLayout<rustc_middle[c35c93541fbaf6fb]::ty::Ty>>>::{closure#0}, rustc_index[731be7b9208c99a6]::vec::IndexVec<rustc_middle[c35c93541fbaf6fb]::mir::query::CoroutineSavedLocal, rustc_abi[a261153e5dfc86cc]::layout::ty::TyAndLayout<rustc_middle[c35c93541fbaf6fb]::ty::Ty>>>
  46:     0x7da4d3f3027b - rustc_ty_utils[c2f95faedb959599]::layout::layout_of_uncached
  47:     0x7da4d3f22b4e - rustc_ty_utils[c2f95faedb959599]::layout::layout_of
  48:     0x7da4d3f22aaa - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>
  49:     0x7da4d3f2189c - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::DefaultCache<rustc_middle[c35c93541fbaf6fb]::ty::PseudoCanonicalInput<rustc_middle[c35c93541fbaf6fb]::ty::Ty>, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  50:     0x7da4d3f214e7 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::layout_of::get_query_non_incr::__rust_end_short_backtrace
  51:     0x7da4d461d766 - <rustc_mir_transform[86a227439405b463]::known_panics_lint::KnownPanicsLint as rustc_mir_transform[86a227439405b463]::pass_manager::MirLint>::run_lint
  52:     0x7da4d380bea7 - rustc_mir_transform[86a227439405b463]::run_analysis_to_runtime_passes
  53:     0x7da4d3cbb625 - rustc_mir_transform[86a227439405b463]::mir_drops_elaborated_and_const_checked
  54:     0x7da4d3cbaff7 - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 8usize]>>
  55:     0x7da4d3adc4e6 - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_data_structures[8c4d114b892fc81f]::vec_cache::VecCache<rustc_span[767accb19bf8aef3]::def_id::LocalDefId, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[13fd671b9de95920]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  56:     0x7da4d3adbdd2 - rustc_query_impl[c99fb05ce5425a5b]::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
  57:     0x7da4d3d12210 - rustc_interface[b13b618c5853daff]::passes::run_required_analyses
  58:     0x7da4d47db39e - rustc_interface[b13b618c5853daff]::passes::analysis
  59:     0x7da4d47db375 - rustc_query_impl[c99fb05ce5425a5b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[c99fb05ce5425a5b]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 0usize]>>
  60:     0x7da4d475363a - rustc_query_system[13fd671b9de95920]::query::plumbing::try_execute_query::<rustc_query_impl[c99fb05ce5425a5b]::DynamicConfig<rustc_query_system[13fd671b9de95920]::query::caches::SingleCache<rustc_middle[c35c93541fbaf6fb]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[c99fb05ce5425a5b]::plumbing::QueryCtxt, false>
  61:     0x7da4d475330f - rustc_query_impl[c99fb05ce5425a5b]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  62:     0x7da4d4a1f0c7 - rustc_interface[b13b618c5853daff]::passes::create_and_enter_global_ctxt::<core[844c48195e089da5]::option::Option<rustc_interface[b13b618c5853daff]::queries::Linker>, rustc_driver_impl[2b29d548aa47efe8]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  63:     0x7da4d48f50a6 - rustc_interface[b13b618c5853daff]::interface::run_compiler::<(), rustc_driver_impl[2b29d548aa47efe8]::run_compiler::{closure#0}>::{closure#1}
  64:     0x7da4d48ca07e - std[a3033ab4cf040dbc]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[b13b618c5853daff]::util::run_in_thread_with_globals<rustc_interface[b13b618c5853daff]::util::run_in_thread_pool_with_globals<rustc_interface[b13b618c5853daff]::interface::run_compiler<(), rustc_driver_impl[2b29d548aa47efe8]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  65:     0x7da4d48ca4eb - <<std[a3033ab4cf040dbc]::thread::Builder>::spawn_unchecked_<rustc_interface[b13b618c5853daff]::util::run_in_thread_with_globals<rustc_interface[b13b618c5853daff]::util::run_in_thread_pool_with_globals<rustc_interface[b13b618c5853daff]::interface::run_compiler<(), rustc_driver_impl[2b29d548aa47efe8]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[844c48195e089da5]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  66:     0x7da4d48cb8eb - std::sys::pal::unix::thread::Thread::new::thread_start::hcb4e67cfc7257238
  67:     0x7da4ce6a370a - <unknown>
  68:     0x7da4ce727aac - <unknown>
  69:                0x0 - <unknown>

error: 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: please make sure that you have updated to the latest nightly

note: please attach the file at `/home/matthias/vcs/github/CRED/rustc-ice-2025-05-13T19_11_20-2230674.txt` to your bug report

note: compiler flags: --crate-type lib -Z validate-mir

query stack during panic:
#0 [mir_shims] generating MIR shim for `core::future::async_drop::async_drop_in_place::{closure#0}`, instance=AsyncDropGlue(DefId(2:15267 ~ core[844c]::future::async_drop::async_drop_in_place::{closure#0}), Coroutine(DefId(2:15267 ~ core[844c]::future::async_drop::async_drop_in_place::{closure#0}), [c, (), core::future::ResumeTy, (), (), CoroutineWitness(DefId(2:15267 ~ core[844c]::future::async_drop::async_drop_in_place::{closure#0}), [c]), (*mut c,)]))
#1 [layout_of] computing layout of `{async fn body of core::future::async_drop::async_drop_in_place<c>()}`
#2 [layout_of] computing layout of `core::mem::manually_drop::ManuallyDrop<{async fn body of core::future::async_drop::async_drop_in_place<c>()}>`
#3 [layout_of] computing layout of `core::mem::maybe_uninit::MaybeUninit<{async fn body of core::future::async_drop::async_drop_in_place<c>()}>`
#4 [layout_of] computing layout of `core::mem::maybe_uninit::MaybeUninit<core::future::async_drop::async_drop_in_place::{opaque#0}>`
#5 [layout_of] computing layout of `{async fn body of bar()}`
#6 [mir_drops_elaborated_and_const_checked] elaborating drops for `bar`
#7 [analysis] running analysis passes on this crate
end of query stack
warning: 3 warnings emitted

[moxian]

smaller:

//@ compile-flags --edition=2021 --crate-type lib -Zvalidate-mir
#![feature(async_drop)]
use std::{future::AsyncDrop, pin::Pin};

struct HasAsyncDrop ;
impl Drop for HasAsyncDrop {
    fn drop(&mut self) {}
}
impl AsyncDrop for HasAsyncDrop {
    async fn drop(self: Pin<&mut Self>) {}
}

struct Holder {
    inner: HasAsyncDrop,
}
async fn bar() {
    Holder {
        inner: HasAsyncDrop
   };
}

Bisects to initial async drop codegen PR 7d65abf

@rustbot label: +S-has-mcve +S-has-bisection +-Zvalidate-mir +requires-incomplete-features -needs-triage