[ICE]: panicked at compiler/rustc_mir_build/src/build/expr/as_rvalue.rs:210:65

[wxie7]

Code

#![allow(dead_code)]
#![allow(non_camel_case_types)]
pub fn main() {
    #[repr(simd)]
    enum x {
        foo,
    }
    impl ::std::cmp::PartialEq for x {
        fn eq(&self, other: &x) -> bool {
            (*self) as isize == (*other) as isize
        }
        fn ne(&self, other: &x) -> bool {
            !(*self).eq(other)
        }
    }
}

Meta

rustc --version --verbose:

rustc 1.84.0-nightly (b91a3a056 2024-11-07)
binary: rustc
commit-hash: b91a3a05609a46f73d23e0995ae7ebb4a4f429a5
commit-date: 2024-11-07
host: x86_64-unknown-linux-gnu
release: 1.84.0-nightly
LLVM version: 19.1.3

Error output

error[E0517]: attribute should be applied to a struct
 --> mutant.rs:4:12
  |
4 |       #[repr(simd)]
  |              ^^^^
5 | /     enum x {
6 | |         foo,
7 | |     }
  | |_____- not a struct

thread 'rustc' panicked at compiler/rustc_mir_build/src/build/expr/as_rvalue.rs:210:65:
called `Result::unwrap()` on an `Err` value: Unknown(main::x)
stack backtrace:
...
note: compiler flags: --crate-type staticlib -C link-dead-code -C debuginfo=2 -C opt-level=3 -Z mir-opt-level=3

query stack during panic:
#0 [mir_built] building MIR for `main::<impl at mutant.rs:8:5: 8:37>::eq`
#1 [check_unsafety] unsafety-checking `main::<impl at mutant.rs:8:5: 8:37>::eq`
end of query stack
error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0517`.

Backtrace

stack backtrace:
   0:     0x7f2e77c5517a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hfadad24fb33e3d1a
   1:     0x7f2e784040a6 - core::fmt::write::h42d25fbda60cd99f
   2:     0x7f2e797c3351 - std::io::Write::write_fmt::hc2819193e80b365e
   3:     0x7f2e77c54fd2 - std::sys::backtrace::BacktraceLock::print::h9450230402d77664
   4:     0x7f2e77c574d6 - std::panicking::default_hook::{{closure}}::h739047d4d787c596
   5:     0x7f2e77c57320 - std::panicking::default_hook::h203d1229480f37a5
   6:     0x7f2e76cd2269 - std[56fe22ad9ea837fd]::panicking::update_hook::<alloc[b5641001d343df5f]::boxed::Box<rustc_driver_impl[945e9afaf49c7d35]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x7f2e77c57be8 - std::panicking::rust_panic_with_hook::h657fdcc17f7e2546
   8:     0x7f2e77c579ba - std::panicking::begin_panic_handler::{{closure}}::h6c1a7592f2611ed5
   9:     0x7f2e77c55629 - std::sys::backtrace::__rust_end_short_backtrace::h3e1efd1ff0b15465
  10:     0x7f2e77c5767c - rust_begin_unwind
  11:     0x7f2e746cd320 - core::panicking::panic_fmt::h41647251c9f15c53
  12:     0x7f2e74b86b06 - core::result::unwrap_failed::h54d537d424da3d7e
  13:     0x7f2e78815917 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::as_rvalue
  14:     0x7f2e78823575 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::expr_into_dest
  15:     0x7f2e7881b509 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::as_temp::{closure#0}
  16:     0x7f2e78817c09 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::as_operand
  17:     0x7f2e788178f6 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::as_operand
  18:     0x7f2e78813e78 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::as_rvalue
  19:     0x7f2e78823575 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::expr_into_dest
  20:     0x7f2e78826a42 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::expr_into_dest
  21:     0x7f2e7906682b - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::ast_block_stmts
  22:     0x7f2e7906578c - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::ast_block
  23:     0x7f2e788248f0 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::expr_into_dest
  24:     0x7f2e78826a42 - <rustc_mir_build[cc4ad6006833d10]::build::Builder>::expr_into_dest
  25:     0x7f2e787ff369 - rustc_mir_build[cc4ad6006833d10]::build::mir_build
  26:     0x7f2e78407544 - rustc_mir_transform[c62e463fc59f8bd1]::mir_built
  27:     0x7f2e78407507 - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  28:     0x7f2e78b23681 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  29:     0x7f2e78b2324d - rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
  30:     0x7f2e74868ce1 - rustc_mir_build[cc4ad6006833d10]::check_unsafety::check_unsafety
  31:     0x7f2e78e2357d - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 0usize]>>
  32:     0x7f2e78e2380f - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  33:     0x7f2e78e234c1 - rustc_query_impl[1357963d8dd30e8b]::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
  34:     0x7f2e78c6912c - rustc_interface[5fea8bf9cd0b71b5]::passes::run_required_analyses
  35:     0x7f2e7920861e - rustc_interface[5fea8bf9cd0b71b5]::passes::analysis
  36:     0x7f2e792085ef - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  37:     0x7f2e79392cee - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::SingleCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  38:     0x7f2e793929ce - rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  39:     0x7f2e7928707a - rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler::<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}
  40:     0x7f2e792cd5d0 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>
  41:     0x7f2e792cd9eb - <<std[56fe22ad9ea837fd]::thread::Builder>::spawn_unchecked_<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#1} as core[5ba82ee3405aa490]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  42:     0x7f2e792ce4b9 - std::sys::pal::unix::thread::Thread::new::thread_start::hb3d6392adeea417c
  43:     0x7f2e7346bac3 - start_thread
                               at ./nptl/pthread_create.c:442:8
  44:     0x7f2e734fd850 - __GI___clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  45:                0x0 - <unknown>

Anything else

Could this be related to #121097 ?

[cyrgani]

Reduced:

#[repr(simd)]
enum X {
    Foo,
}
fn eq(x: X) {
    x as isize;
}

So this is indeed the same as #121097.

[matthiaskrgr]

thanks @cyrgani , closing as duplicate..