ice: `!layout.abi.is_uninhabited()`

[matthiaskrgr]

Code

fn test_questionmark() -> Result<(), ()> {
    { 
    Ok(Ok(())) }??;
    Ok(())
}

fn main() {
    test_questionmark().unwrap();
}

Meta

rustc --version --verbose:

rustc 1.77.0-nightly (039d88792 2024-01-25)
binary: rustc
commit-hash: 039d887928361df98ca530471b609378be93983a
commit-date: 2024-01-25
host: x86_64-unknown-linux-gnu
release: 1.77.0-nightly
LLVM version: 17.0.6

Error output

rustc --edition=2021 -Zvalidate-mir -Zmir-opt-level=5 -Zunsound-mir-opts treereduce.out

<output>

Backtrace

thread 'rustc' panicked at /rustc/039d887928361df98ca530471b609378be93983a/compiler/rustc_const_eval/src/interpret/projection.rs:222:9:
assertion failed: !layout.abi.is_uninhabited()
stack backtrace:
   0:     0x7f5446c60e86 - std::backtrace_rs::backtrace::libunwind::trace::h6cfe1dadce630036
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f5446c60e86 - std::backtrace_rs::backtrace::trace_unsynchronized::h5abdc3a3af169812
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f5446c60e86 - std::sys_common::backtrace::_print_fmt::hcccf5f4ed8ac28ec
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f5446c60e86 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h0cd6b2504011a18d
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f5446cb3740 - core::fmt::rt::Argument::fmt::hebc7f15d5b5e154a
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/core/src/fmt/rt.rs:142:9
   5:     0x7f5446cb3740 - core::fmt::write::h78ef4d880a3b55e6
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f5446c5484f - std::io::Write::write_fmt::h75a99451377d7b6f
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/io/mod.rs:1810:15
   7:     0x7f5446c60c64 - std::sys_common::backtrace::_print::h8a38d616c1aebba6
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f5446c60c64 - std::sys_common::backtrace::print::h79c60f2fb75766d0
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f5446c639f7 - std::panicking::default_hook::{{closure}}::h813367f17128fa78
  10:     0x7f5446c63759 - std::panicking::default_hook::h9a25a86054ecacab
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/panicking.rs:292:9
  11:     0x7f544395b54c - std[2d71ddef07c6339c]::panicking::update_hook::<alloc[562726949fe228d0]::boxed::Box<rustc_driver_impl[b5150a49514b53ca]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f5446c64146 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hcf7035261c2dc2f4
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/alloc/src/boxed.rs:2030:9
  13:     0x7f5446c64146 - std::panicking::rust_panic_with_hook::h4227801d760693f2
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/panicking.rs:785:13
  14:     0x7f5446c63e59 - std::panicking::begin_panic_handler::{{closure}}::h27ae2df27d1bb7d2
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/panicking.rs:651:13
  15:     0x7f5446c61386 - std::sys_common::backtrace::__rust_end_short_backtrace::h08fba0b4aacd23ed
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7f5446c63be4 - rust_begin_unwind
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/panicking.rs:647:5
  17:     0x7f5446cafe45 - core::panicking::panic_fmt::haba40cee92bb0ca8
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/core/src/panicking.rs:72:14
  18:     0x7f5446caff03 - core::panicking::panic::h7ad960fca41cf254
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/core/src/panicking.rs:144:5
  19:     0x7f54461d9dbc - <rustc_const_eval[ed1a705a637fd062]::interpret::eval_context::InterpCx<rustc_mir_transform[963d0b588447d95f]::dataflow_const_prop::DummyMachine>>::project_downcast::<rustc_const_eval[ed1a705a637fd062]::interpret::operand::OpTy>.cold.0
  20:     0x7f5443f9d12f - <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#0}
  21:     0x7f5443ee8acb - <rustc_mir_dataflow[c9588bf85862e893]::value_analysis::Map>::for_each_projection_value::<rustc_const_eval[ed1a705a637fd062]::interpret::operand::OpTy, <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#0}, <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#1}>
  22:     0x7f5443ee8b06 - <rustc_mir_dataflow[c9588bf85862e893]::value_analysis::Map>::for_each_projection_value::<rustc_const_eval[ed1a705a637fd062]::interpret::operand::OpTy, <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#0}, <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#1}>
  23:     0x7f5443ee8b06 - <rustc_mir_dataflow[c9588bf85862e893]::value_analysis::Map>::for_each_projection_value::<rustc_const_eval[ed1a705a637fd062]::interpret::operand::OpTy, <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#0}, <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_constant::{closure#1}>
  24:     0x7f5443f9d732 - <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::process_operand
  25:     0x7f5443f9ca01 - <rustc_mir_transform[963d0b588447d95f]::jump_threading::TOFinder>::find_opportunity
  26:     0x7f5443f9b459 - <rustc_mir_transform[963d0b588447d95f]::jump_threading::JumpThreading as rustc_middle[4fa995cc45e7b4f0]::mir::MirPass>::run_pass
  27:     0x7f5444cc0a6e - rustc_mir_transform[963d0b588447d95f]::pass_manager::run_passes_inner
  28:     0x7f5444df8789 - rustc_mir_transform[963d0b588447d95f]::optimized_mir
  29:     0x7f5444c5e975 - rustc_query_impl[9793c2de2b9a9b0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9793c2de2b9a9b0]::query_impl::optimized_mir::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 8usize]>>
  30:     0x7f5444c5ef61 - rustc_query_system[822af879e6e17ac5]::query::plumbing::try_execute_query::<rustc_query_impl[9793c2de2b9a9b0]::DynamicConfig<rustc_query_system[822af879e6e17ac5]::query::caches::DefIdCache<rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[9793c2de2b9a9b0]::plumbing::QueryCtxt, false>
  31:     0x7f5444c5e79e - rustc_query_impl[9793c2de2b9a9b0]::query_impl::optimized_mir::get_query_non_incr::__rust_end_short_backtrace
  32:     0x7f5444dca77c - rustc_middle[4fa995cc45e7b4f0]::query::plumbing::query_get_at::<rustc_query_system[822af879e6e17ac5]::query::caches::DefIdCache<rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 8usize]>>>
  33:     0x7f5444dc9b34 - rustc_mir_transform[963d0b588447d95f]::cross_crate_inline::cross_crate_inlinable
  34:     0x7f5444dc571b - rustc_query_impl[9793c2de2b9a9b0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9793c2de2b9a9b0]::query_impl::cross_crate_inlinable::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 1usize]>>
  35:     0x7f5444dc59f4 - rustc_query_system[822af879e6e17ac5]::query::plumbing::try_execute_query::<rustc_query_impl[9793c2de2b9a9b0]::DynamicConfig<rustc_query_system[822af879e6e17ac5]::query::caches::DefIdCache<rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[9793c2de2b9a9b0]::plumbing::QueryCtxt, false>
  36:     0x7f5444dc544d - rustc_query_impl[9793c2de2b9a9b0]::query_impl::cross_crate_inlinable::get_query_non_incr::__rust_end_short_backtrace
  37:     0x7f544556e2c3 - <rustc_mir_transform[963d0b588447d95f]::inline::Inliner>::try_inlining
  38:     0x7f5445572c91 - <rustc_mir_transform[963d0b588447d95f]::inline::Inliner>::process_blocks
  39:     0x7f5444dca38b - <rustc_mir_transform[963d0b588447d95f]::inline::Inline as rustc_middle[4fa995cc45e7b4f0]::mir::MirPass>::run_pass
  40:     0x7f5444cc0a6e - rustc_mir_transform[963d0b588447d95f]::pass_manager::run_passes_inner
  41:     0x7f5444df8789 - rustc_mir_transform[963d0b588447d95f]::optimized_mir
  42:     0x7f5444c5e975 - rustc_query_impl[9793c2de2b9a9b0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9793c2de2b9a9b0]::query_impl::optimized_mir::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 8usize]>>
  43:     0x7f5444c5ef61 - rustc_query_system[822af879e6e17ac5]::query::plumbing::try_execute_query::<rustc_query_impl[9793c2de2b9a9b0]::DynamicConfig<rustc_query_system[822af879e6e17ac5]::query::caches::DefIdCache<rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[9793c2de2b9a9b0]::plumbing::QueryCtxt, false>
  44:     0x7f5444c5e79e - rustc_query_impl[9793c2de2b9a9b0]::query_impl::optimized_mir::get_query_non_incr::__rust_end_short_backtrace
  45:     0x7f5441be32fa - <rustc_middle[4fa995cc45e7b4f0]::ty::context::TyCtxt>::instance_mir
  46:     0x7f544292a6c1 - rustc_monomorphize[48429395c8d43f8f]::collector::collect_items_rec::{closure#0}
  47:     0x7f5445a98aa7 - rustc_monomorphize[48429395c8d43f8f]::collector::collect_items_rec
  48:     0x7f5445a9457b - rustc_monomorphize[48429395c8d43f8f]::partitioning::collect_and_partition_mono_items
  49:     0x7f5445a93bd6 - rustc_query_impl[9793c2de2b9a9b0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9793c2de2b9a9b0]::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2}::{closure#0}, rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 24usize]>>
  50:     0x7f5445a93ba5 - <rustc_query_impl[9793c2de2b9a9b0]::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2} as core[240f245c4852827c]::ops::function::FnOnce<(rustc_middle[4fa995cc45e7b4f0]::ty::context::TyCtxt, ())>>::call_once
  51:     0x7f5445a92f47 - rustc_query_system[822af879e6e17ac5]::query::plumbing::try_execute_query::<rustc_query_impl[9793c2de2b9a9b0]::DynamicConfig<rustc_query_system[822af879e6e17ac5]::query::caches::SingleCache<rustc_middle[4fa995cc45e7b4f0]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[9793c2de2b9a9b0]::plumbing::QueryCtxt, false>
  52:     0x7f5445a92c49 - rustc_query_impl[9793c2de2b9a9b0]::query_impl::collect_and_partition_mono_items::get_query_non_incr::__rust_end_short_backtrace
  53:     0x7f54456a12d6 - rustc_codegen_ssa[c09e93a0fed8f3a3]::base::codegen_crate::<rustc_codegen_llvm[f9a1bb7d58de6587]::LlvmCodegenBackend>
  54:     0x7f54456a0f75 - <rustc_codegen_llvm[f9a1bb7d58de6587]::LlvmCodegenBackend as rustc_codegen_ssa[c09e93a0fed8f3a3]::traits::backend::CodegenBackend>::codegen_crate
  55:     0x7f544569f370 - rustc_interface[1f676e8d56904132]::passes::start_codegen
  56:     0x7f544569eab4 - <rustc_interface[1f676e8d56904132]::queries::Queries>::codegen_and_build_linker
  57:     0x7f544598d74a - rustc_interface[1f676e8d56904132]::interface::run_compiler::<core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>, rustc_driver_impl[b5150a49514b53ca]::run_compiler::{closure#0}>::{closure#0}
  58:     0x7f5445bddb06 - std[2d71ddef07c6339c]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[1f676e8d56904132]::util::run_in_thread_with_globals<rustc_interface[1f676e8d56904132]::util::run_in_thread_pool_with_globals<rustc_interface[1f676e8d56904132]::interface::run_compiler<core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>, rustc_driver_impl[b5150a49514b53ca]::run_compiler::{closure#0}>::{closure#0}, core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>>::{closure#0}, core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>>
  59:     0x7f5445bdd933 - <<std[2d71ddef07c6339c]::thread::Builder>::spawn_unchecked_<rustc_interface[1f676e8d56904132]::util::run_in_thread_with_globals<rustc_interface[1f676e8d56904132]::util::run_in_thread_pool_with_globals<rustc_interface[1f676e8d56904132]::interface::run_compiler<core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>, rustc_driver_impl[b5150a49514b53ca]::run_compiler::{closure#0}>::{closure#0}, core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>>::{closure#0}, core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[240f245c4852827c]::result::Result<(), rustc_span[6ce47fc6caf6b4a2]::ErrorGuaranteed>>::{closure#1} as core[240f245c4852827c]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  60:     0x7f5446c6d735 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hce32de47adeb9ab6
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/alloc/src/boxed.rs:2016:9
  61:     0x7f5446c6d735 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h22cf91fbafc72b5d
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/alloc/src/boxed.rs:2016:9
  62:     0x7f5446c6d735 - std::sys::pal::unix::thread::Thread::new::thread_start::h4f77d8ca10599a35
                               at /rustc/039d887928361df98ca530471b609378be93983a/library/std/src/sys/pal/unix/thread.rs:108:17
  63:     0x7f5440aaa9eb - <unknown>
  64:     0x7f5440b2e7cc - <unknown>
  65:                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 attach the file at `/tmp/im/rustc-ice-2024-01-25T11_27_00-1814810.txt` to your bug report

note: compiler flags: -Z validate-mir -Z mir-opt-level=5 -Z unsound-mir-opts

query stack during panic:
#0 [optimized_mir] optimizing MIR for `test_questionmark`
#1 [cross_crate_inlinable] whether the item should be made inlinable across crates
#2 [optimized_mir] optimizing MIR for `main`
#3 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack

[compiler-errors]

-Zunsound-mir-opts + -Zvalidate-mir seem like options that when paired together would cause issues... At first glance, I'm actually not sure why this is filed as a bug.

[saethlin]

I agree. Nobody should be testing -Zunsound-mir-opts, I don't know why those passes are even in the codebase.

But this is a bug. I've found this in real code with a much smaller set of flags:

-Zmir-enable-passes=+JumpThreading

And this bisects to #119627 Bisected by hand, there's no nightly with that PR yet. Don't know where Matthias got that toolchain.

[compiler-errors]

Afaict @matthiaskrgr likes to do ICE testing against master 😺

[djkoloski]

We just hit this on Fuchsia as well. I think we should revert the PR until we fix this issue and reland it.

[matthiaskrgr]

Another one with --crate-type lib --emit=mir

pub enum HiddenType {}

pub trait HiddenTrait {}

pub enum MyLibType {}


impl From<HiddenType> for MyLibType {
    fn from(it: HiddenType) -> MyLibType {
        match it {}
    }
}

pub struct T<T>(T);

impl From<T<T<T<T<HiddenType>>>>> for MyLibType {
    fn from(it: T<T<T<T<HiddenType>>>>) -> MyLibType {
        todo!()
    }
}