ICE: `region variables should not be hashed`

[matthiaskrgr]

Code

rustc l.rs -Cincremental=.

fn main() {
    unsafe { std::mem::transmute::<usize, extern "C-cmse-nonsecure-call" fn(&'a ())>(5); }
}

Meta

rustc --version --verbose:

rustc 1.83.0-nightly (6b9676b45 2024-10-12)
binary: rustc
commit-hash: 6b9676b45431a1e531b9c5f7bd289fc36a312749
commit-date: 2024-10-12
host: x86_64-unknown-linux-gnu
release: 1.83.0-nightly
LLVM version: 19.1.1

Error output

error[E0261]: use of undeclared lifetime name `'a`
 --> l.rs:3:78
  |
3 |     unsafe { std::mem::transmute::<usize, extern "C-cmse-nonsecure-call" fn(&'a ())>(5); }
  |                                                                              ^^ undeclared lifetime
  |
  = note: for more information on higher-ranked polymorphism, visit https://doc.rust-lang.org/nomicon/hrtb.html
help: consider making the type lifetime-generic with a new `'a` lifetime
  |
3 |     unsafe { std::mem::transmute::<usize, for<'a> extern "C-cmse-nonsecure-call" fn(&'a ())>(5); }
  |                                           +++++++
help: consider introducing lifetime `'a` here
  |
2 | fn main<'a>() {
  |        ++++

error[E0658]: C-cmse-nonsecure-call ABI is experimental and subject to change
 --> l.rs:3:50
  |
3 |     unsafe { std::mem::transmute::<usize, extern "C-cmse-nonsecure-call" fn(&'a ())>(5); }
  |                                                  ^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #81391 <https://github.com/rust-lang/rust/issues/81391> for more information
  = help: add `#![feature(abi_c_cmse_nonsecure_call)]` to the crate attributes to enable
  = note: this compiler was built on 2024-10-12; consider upgrading it if it is out of date

Backtrace

thread 'rustc' panicked at /rustc/6b9676b45431a1e531b9c5f7bd289fc36a312749/compiler/rustc_type_ir/src/region_kind.rs:238:17:
region variables should not be hashed: '?0
stack backtrace:
   0:     0x724fa79ca41a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h8b2043b14ab05304
   1:     0x724fa82034a6 - core::fmt::write::hf9887d457cdbc966
   2:     0x724fa941e951 - std::io::Write::write_fmt::ha659b10ba83556c4
   3:     0x724fa79ca272 - std::sys::backtrace::BacktraceLock::print::hf85affc2cf4419f7
   4:     0x724fa79cc746 - std::panicking::default_hook::{{closure}}::hde5089a7c4039350
   5:     0x724fa79cc590 - std::panicking::default_hook::hf6b38aee6b14f9c5
   6:     0x724fa6a249ff - std[b9c4ef606f74e7a3]::panicking::update_hook::<alloc[8572a0bce597bd99]::boxed::Box<rustc_driver_impl[e627dad8a5ad147c]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x724fa79cce58 - std::panicking::rust_panic_with_hook::hafbd7f0e47ba5b9a
   8:     0x724fa79ccc2a - std::panicking::begin_panic_handler::{{closure}}::heb41764772c3697f
   9:     0x724fa79ca8c9 - std::sys::backtrace::__rust_end_short_backtrace::hcc198f67593013e0
  10:     0x724fa79cc8ec - rust_begin_unwind
  11:     0x724fa53758b0 - core::panicking::panic_fmt::hd2428fc03641ffed
  12:     0x724fa83b3e87 - <rustc_type_ir[b367b32ea2ea77f7]::ty_info::WithCachedTypeInfo<rustc_type_ir[b367b32ea2ea77f7]::ty_kind::TyKind<rustc_middle[3e2c59a537b514a7]::ty::context::TyCtxt>> as rustc_data_structures[d65d6190c281c564]::stable_hasher::HashStable<rustc_query_system[2162b26b9e1c67a3]::ich::hcx::StableHashingContext>>::hash_stable
  13:     0x724fa87ca803 - rustc_query_system[2162b26b9e1c67a3]::query::plumbing::try_execute_query::<rustc_query_impl[5ae70715c347e1a5]::DynamicConfig<rustc_query_system[2162b26b9e1c67a3]::query::caches::DefaultCache<rustc_middle[3e2c59a537b514a7]::ty::ParamEnvAnd<rustc_middle[3e2c59a537b514a7]::ty::Ty>, rustc_middle[3e2c59a537b514a7]::query::erase::Erased<[u8; 16usize]>>, false, true, false>, rustc_query_impl[5ae70715c347e1a5]::plumbing::QueryCtxt, true>
  14:     0x724fa87c9b29 - rustc_query_impl[5ae70715c347e1a5]::query_impl::layout_of::get_query_incr::__rust_end_short_backtrace
  15:     0x724fa911295e - rustc_middle[3e2c59a537b514a7]::query::plumbing::query_get_at::<rustc_query_system[2162b26b9e1c67a3]::query::caches::DefaultCache<rustc_middle[3e2c59a537b514a7]::ty::ParamEnvAnd<rustc_middle[3e2c59a537b514a7]::ty::Ty>, rustc_middle[3e2c59a537b514a7]::query::erase::Erased<[u8; 16usize]>>>
  16:     0x724fa8b042e0 - <dyn rustc_hir_analysis[b8eef9b6240b8e77]::hir_ty_lowering::HirTyLowerer>::lower_fn_ty
  17:     0x724fa8b0a4bf - <dyn rustc_hir_analysis[b8eef9b6240b8e77]::hir_ty_lowering::HirTyLowerer>::lower_ty
  18:     0x724fa82b539e - <<rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::instantiate_value_path::CtorGenericArgsCtxt as rustc_hir_analysis[b8eef9b6240b8e77]::hir_ty_lowering::GenericArgsLowerer>::provided_kind
  19:     0x724fa82ad3e1 - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::instantiate_value_path
  20:     0x724fa82a16d0 - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_expr_path
  21:     0x724fa8e74092 - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  22:     0x724fa8e75d77 - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  23:     0x724fa8e6f6aa - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_block_with_expected
  24:     0x724fa8e76923 - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  25:     0x724fa8e6f78a - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_block_with_expected
  26:     0x724fa8e76923 - <rustc_hir_typeck[fded10133472f41e]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  27:     0x724fa8b91a26 - rustc_hir_typeck[fded10133472f41e]::check::check_fn
  28:     0x724fa8b86761 - rustc_hir_typeck[fded10133472f41e]::typeck
  29:     0x724fa8b860cf - rustc_query_impl[5ae70715c347e1a5]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[5ae70715c347e1a5]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3e2c59a537b514a7]::query::erase::Erased<[u8; 8usize]>>
  30:     0x724fa85ffbd7 - rustc_query_system[2162b26b9e1c67a3]::query::plumbing::try_execute_query::<rustc_query_impl[5ae70715c347e1a5]::DynamicConfig<rustc_query_system[2162b26b9e1c67a3]::query::caches::VecCache<rustc_span[6af807c565a72bbf]::def_id::LocalDefId, rustc_middle[3e2c59a537b514a7]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[5ae70715c347e1a5]::plumbing::QueryCtxt, true>
  31:     0x724fa85da854 - rustc_query_impl[5ae70715c347e1a5]::query_impl::typeck::get_query_incr::__rust_end_short_backtrace
  32:     0x724fa85fbb61 - <rustc_middle[3e2c59a537b514a7]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[b8eef9b6240b8e77]::check_crate::{closure#4}>::{closure#0}
  33:     0x724fa85f9a9b - rustc_hir_analysis[b8eef9b6240b8e77]::check_crate
  34:     0x724fa85f64d7 - rustc_interface[a3bf963724784d96]::passes::run_required_analyses
  35:     0x724fa8f6a65e - rustc_interface[a3bf963724784d96]::passes::analysis
  36:     0x724fa8f6a631 - rustc_query_impl[5ae70715c347e1a5]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[5ae70715c347e1a5]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3e2c59a537b514a7]::query::erase::Erased<[u8; 1usize]>>
  37:     0x724fa92d530d - rustc_query_system[2162b26b9e1c67a3]::query::plumbing::try_execute_query::<rustc_query_impl[5ae70715c347e1a5]::DynamicConfig<rustc_query_system[2162b26b9e1c67a3]::query::caches::SingleCache<rustc_middle[3e2c59a537b514a7]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[5ae70715c347e1a5]::plumbing::QueryCtxt, true>
  38:     0x724fa92d4dfa - rustc_query_impl[5ae70715c347e1a5]::query_impl::analysis::get_query_incr::__rust_end_short_backtrace
  39:     0x724fa8f7b0de - rustc_interface[a3bf963724784d96]::interface::run_compiler::<core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>, rustc_driver_impl[e627dad8a5ad147c]::run_compiler::{closure#0}>::{closure#1}
  40:     0x724fa90244d4 - std[b9c4ef606f74e7a3]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[a3bf963724784d96]::util::run_in_thread_with_globals<rustc_interface[a3bf963724784d96]::util::run_in_thread_pool_with_globals<rustc_interface[a3bf963724784d96]::interface::run_compiler<core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>, rustc_driver_impl[e627dad8a5ad147c]::run_compiler::{closure#0}>::{closure#1}, core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>>::{closure#0}, core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>>
  41:     0x724fa90248e8 - <<std[b9c4ef606f74e7a3]::thread::Builder>::spawn_unchecked_<rustc_interface[a3bf963724784d96]::util::run_in_thread_with_globals<rustc_interface[a3bf963724784d96]::util::run_in_thread_pool_with_globals<rustc_interface[a3bf963724784d96]::interface::run_compiler<core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>, rustc_driver_impl[e627dad8a5ad147c]::run_compiler::{closure#0}>::{closure#1}, core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>>::{closure#0}, core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[208fe08024603fa1]::result::Result<(), rustc_span[6af807c565a72bbf]::ErrorGuaranteed>>::{closure#1} as core[208fe08024603fa1]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  42:     0x724fa90253ab - std::sys::pal::unix::thread::Thread::new::thread_start::h0e0386f9f8272e66
  43:     0x724faa67739d - <unknown>
  44:     0x724faa6fc49c - <unknown>
  45:                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 `/tmp/im/rustc-ice-2024-10-13T07_13_22-625025.txt` to your bug report

note: compiler flags: -C incremental=[REDACTED]

query stack during panic:
panicked at /rustc/6b9676b45431a1e531b9c5f7bd289fc36a312749/compiler/rustc_type_ir/src/region_kind.rs:238:17:

thread panicked while processing panic. aborting.
[2]    625025 IOT instruction  rustc l.rs -Cincremental=.

[matthiaskrgr]

bisects to #127814

[jieyouxu]

cc @folkertdev

[folkertdev]

yeah, basically the validation works great for correct types, but fails in various ways for types that already have other errors. I've asked around whether there is some way to run the analysis a bit later (after erroneous types have been weeded out, but haven't really heard anything back. So I don't know how to fix this other than in an ad-hoc way.