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VirgileHenry opened this issue May 30, 2025 · 2 comments
Open

ICE on feature generic_const_exprs when trying to create comp time arrays #141801

VirgileHenry opened this issue May 30, 2025 · 2 comments
Labels
C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

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@VirgileHenry
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Code

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]

const fn arr_insert<const N: usize, T: Copy>(arr: [T; N], elem: T, index: usize) -> [T; N + 1] {
    assert!(index <= N);

    // Since we have T: Copy, we can dummy init the result
    let mut out = [elem; N + 1];
    let mut i = 0;

    while i < index {
        out[i] = arr[i];
        i += 1;
    }

    out[i] = elem;

    while i < N {
        out[i + 1] = arr[i];
        i += 1;
    }

    out
}

const MY_ARR: [i32; 3] = arr_insert([0, 2], 1, 1);

fn main() {
    assert_eq!(MY_ARR, [0, 1, 2]);
}

Meta

rustc --version --verbose:

rustc 1.89.0-nightly (1bbd62e54 2025-05-29)
binary: rustc
commit-hash: 1bbd62e547ba5cc08ccb44c27def3d33195d2dd5
commit-date: 2025-05-29
host: x86_64-unknown-linux-gnu
release: 1.89.0-nightly
LLVM version: 20.1.5

Error output

Compiling playground v0.0.1 (/playground)
error: internal compiler error: compiler/rustc_const_eval/src/check_consts/qualifs.rs:359:13: expected ConstKind::Param or ConstKind::Value here, found UnevaluatedConst { def: DefId(0:8 ~ playground[ab6f]::arr_insert::{constant#2}), args: [N/#0, T/#1] }


thread 'rustc' panicked at compiler/rustc_const_eval/src/check_consts/qualifs.rs:359:13:
Box<dyn Any>
stack backtrace:
   0:     0x7eb3f64a5273 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h05e9f29e57dbb2e9
   1:     0x7eb3f6c02af7 - core::fmt::write::hd2dec42d1c7eed2b
   2:     0x7eb3f649b0f3 - std::io::Write::write_fmt::he35f7ccd30502a06
   3:     0x7eb3f64a50d2 - std::sys::backtrace::BacktraceLock::print::h0f7594efff5cfc74
   4:     0x7eb3f64a8cca - std::panicking::default_hook::{{closure}}::h8c1a12024f8172d5
   5:     0x7eb3f64a884f - std::panicking::default_hook::h9b1e5be56a49e97f
   6:     0x7eb3f550d693 - std[aebe2beb07d4602e]::panicking::update_hook::<alloc[afc79f7023c726bc]::boxed::Box<rustc_driver_impl[fce054646584467]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x7eb3f64a9543 - std::panicking::rust_panic_with_hook::h466604244439fd1e
   8:     0x7eb3f5549d31 - std[aebe2beb07d4602e]::panicking::begin_panic::<rustc_errors[fd968897a4afc233]::ExplicitBug>::{closure#0}
   9:     0x7eb3f553ebe6 - std[aebe2beb07d4602e]::sys::backtrace::__rust_end_short_backtrace::<std[aebe2beb07d4602e]::panicking::begin_panic<rustc_errors[fd968897a4afc233]::ExplicitBug>::{closure#0}, !>
  10:     0x7eb3f553e8c7 - std[aebe2beb07d4602e]::panicking::begin_panic::<rustc_errors[fd968897a4afc233]::ExplicitBug>
  11:     0x7eb3f55537c1 - <rustc_errors[fd968897a4afc233]::diagnostic::BugAbort as rustc_errors[fd968897a4afc233]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7eb3f5b9b32a - rustc_middle[f62d8e2871d7ed5a]::util::bug::opt_span_bug_fmt::<rustc_span[674833ee7b2aca12]::span_encoding::Span>::{closure#0}
  13:     0x7eb3f5b78b2a - rustc_middle[f62d8e2871d7ed5a]::ty::context::tls::with_opt::<rustc_middle[f62d8e2871d7ed5a]::util::bug::opt_span_bug_fmt<rustc_span[674833ee7b2aca12]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x7eb3f5b7899b - rustc_middle[f62d8e2871d7ed5a]::ty::context::tls::with_context_opt::<rustc_middle[f62d8e2871d7ed5a]::ty::context::tls::with_opt<rustc_middle[f62d8e2871d7ed5a]::util::bug::opt_span_bug_fmt<rustc_span[674833ee7b2aca12]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7eb3f2ca9330 - rustc_middle[f62d8e2871d7ed5a]::util::bug::bug_fmt
  16:     0x7eb3f88e53a3 - rustc_const_eval[225f976b6d84e0d4]::check_consts::qualifs::in_operand::<rustc_const_eval[225f976b6d84e0d4]::check_consts::qualifs::HasMutInterior, <rustc_const_eval[225f976b6d84e0d4]::check_consts::resolver::TransferFunction<rustc_const_eval[225f976b6d84e0d4]::check_consts::qualifs::HasMutInterior> as rustc_middle[f62d8e2871d7ed5a]::mir::visit::Visitor>::visit_assign::{closure#0}>.cold
  17:     0x7eb3f7872de5 - <rustc_const_eval[225f976b6d84e0d4]::check_consts::resolver::FlowSensitiveAnalysis<rustc_const_eval[225f976b6d84e0d4]::check_consts::qualifs::HasMutInterior> as rustc_mir_dataflow[27782b7c2b798f03]::framework::Analysis>::apply_primary_statement_effect
  18:     0x7eb3f7874dd1 - <rustc_const_eval[225f976b6d84e0d4]::check_consts::check::Qualifs>::has_mut_interior
  19:     0x7eb3f78748ad - <rustc_const_eval[225f976b6d84e0d4]::check_consts::check::Checker>::qualifs_in_return_place
  20:     0x7eb3f7874195 - rustc_mir_transform[8802a7a466bf19d]::mir_const_qualif
  21:     0x7eb3f7873fe5 - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_const_qualif::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 4usize]>>
  22:     0x7eb3f7873473 - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_query_system[e527f3fe7b1ba41c]::query::caches::DefIdCache<rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 4usize]>>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  23:     0x7eb3f78731cf - rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_const_qualif::get_query_non_incr::__rust_end_short_backtrace
  24:     0x7eb3f3f8b030 - rustc_mir_transform[8802a7a466bf19d]::mir_promoted
  25:     0x7eb3f72a4a5a - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_promoted::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 16usize]>>
  26:     0x7eb3f72a4d08 - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_data_structures[63644864ec52dfbb]::vec_cache::VecCache<rustc_span[674833ee7b2aca12]::def_id::LocalDefId, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 16usize]>, rustc_query_system[e527f3fe7b1ba41c]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  27:     0x7eb3f72a4964 - rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_promoted::get_query_non_incr::__rust_end_short_backtrace
  28:     0x7eb3f6edb68a - rustc_borrowck[16831c75c4923d8d]::mir_borrowck
  29:     0x7eb3f6edb519 - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 8usize]>>
  30:     0x7eb3f6eda2e6 - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_data_structures[63644864ec52dfbb]::vec_cache::VecCache<rustc_span[674833ee7b2aca12]::def_id::LocalDefId, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[e527f3fe7b1ba41c]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  31:     0x7eb3f6ed9bd2 - rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
  32:     0x7eb3f773095b - rustc_mir_transform[8802a7a466bf19d]::mir_drops_elaborated_and_const_checked
  33:     0x7eb3f772ffef - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 8usize]>>
  34:     0x7eb3f6eda2e6 - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_data_structures[63644864ec52dfbb]::vec_cache::VecCache<rustc_span[674833ee7b2aca12]::def_id::LocalDefId, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 8usize]>, rustc_query_system[e527f3fe7b1ba41c]::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  35:     0x7eb3f6ed9b1a - rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
  36:     0x7eb3f7817e91 - rustc_mir_transform[8802a7a466bf19d]::mir_for_ctfe
  37:     0x7eb3f7817d0b - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_for_ctfe::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 8usize]>>
  38:     0x7eb3f6c249bd - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_query_system[e527f3fe7b1ba41c]::query::caches::DefIdCache<rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  39:     0x7eb3f7b1aa22 - rustc_query_impl[b8ddf5711aeae68a]::query_impl::mir_for_ctfe::get_query_non_incr::__rust_end_short_backtrace
  40:     0x7eb3f7addf97 - <rustc_const_eval[225f976b6d84e0d4]::interpret::eval_context::InterpCx<rustc_const_eval[225f976b6d84e0d4]::const_eval::machine::CompileTimeMachine>>::init_fn_call
  41:     0x7eb3f7b1c58f - rustc_const_eval[225f976b6d84e0d4]::const_eval::eval_queries::eval_to_allocation_raw_provider
  42:     0x7eb3f7b1b298 - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::eval_to_allocation_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 24usize]>>
  43:     0x7eb3f78f6f41 - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_query_system[e527f3fe7b1ba41c]::query::caches::DefaultCache<rustc_middle[f62d8e2871d7ed5a]::ty::PseudoCanonicalInput<rustc_middle[f62d8e2871d7ed5a]::mir::interpret::GlobalId>, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  44:     0x7eb3f78f6afb - rustc_query_impl[b8ddf5711aeae68a]::query_impl::eval_to_allocation_raw::get_query_non_incr::__rust_end_short_backtrace
  45:     0x7eb3f78f3ffd - rustc_const_eval[225f976b6d84e0d4]::const_eval::eval_queries::eval_to_const_value_raw_provider
  46:     0x7eb3f78f3e00 - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::eval_to_const_value_raw::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 24usize]>>
  47:     0x7eb3f78f27b8 - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_query_system[e527f3fe7b1ba41c]::query::caches::DefaultCache<rustc_middle[f62d8e2871d7ed5a]::ty::PseudoCanonicalInput<rustc_middle[f62d8e2871d7ed5a]::mir::interpret::GlobalId>, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 24usize]>>, false, true, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  48:     0x7eb3f78f2355 - rustc_query_impl[b8ddf5711aeae68a]::query_impl::eval_to_const_value_raw::get_query_non_incr::__rust_end_short_backtrace
  49:     0x7eb3f6ed8c75 - rustc_hir_analysis[a4b8650fa8fb028e]::check_crate
  50:     0x7eb3f6ed4577 - rustc_interface[82c1fd2543dc0997]::passes::run_required_analyses
  51:     0x7eb3f789249e - rustc_interface[82c1fd2543dc0997]::passes::analysis
  52:     0x7eb3f7892471 - rustc_query_impl[b8ddf5711aeae68a]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[b8ddf5711aeae68a]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 0usize]>>
  53:     0x7eb3f78954ba - rustc_query_system[e527f3fe7b1ba41c]::query::plumbing::try_execute_query::<rustc_query_impl[b8ddf5711aeae68a]::DynamicConfig<rustc_query_system[e527f3fe7b1ba41c]::query::caches::SingleCache<rustc_middle[f62d8e2871d7ed5a]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[b8ddf5711aeae68a]::plumbing::QueryCtxt, false>
  54:     0x7eb3f789507b - rustc_query_impl[b8ddf5711aeae68a]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  55:     0x7eb3f7e09cbf - rustc_interface[82c1fd2543dc0997]::passes::create_and_enter_global_ctxt::<core[50b5a8f5e07183b8]::option::Option<rustc_interface[82c1fd2543dc0997]::queries::Linker>, rustc_driver_impl[fce054646584467]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  56:     0x7eb3f7df9681 - rustc_interface[82c1fd2543dc0997]::interface::run_compiler::<(), rustc_driver_impl[fce054646584467]::run_compiler::{closure#0}>::{closure#1}
  57:     0x7eb3f7db9c06 - std[aebe2beb07d4602e]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[82c1fd2543dc0997]::util::run_in_thread_with_globals<rustc_interface[82c1fd2543dc0997]::util::run_in_thread_pool_with_globals<rustc_interface[82c1fd2543dc0997]::interface::run_compiler<(), rustc_driver_impl[fce054646584467]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  58:     0x7eb3f7db98ef - <<std[aebe2beb07d4602e]::thread::Builder>::spawn_unchecked_<rustc_interface[82c1fd2543dc0997]::util::run_in_thread_with_globals<rustc_interface[82c1fd2543dc0997]::util::run_in_thread_pool_with_globals<rustc_interface[82c1fd2543dc0997]::interface::run_compiler<(), rustc_driver_impl[fce054646584467]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[50b5a8f5e07183b8]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  59:     0x7eb3f7dbaebd - std::sys::pal::unix::thread::Thread::new::thread_start::h45be790786894548
  60:     0x7eb3f188aaa4 - <unknown>
  61:     0x7eb3f1917a34 - clone
  62:                0x0 - <unknown>
Backtrace 

   Compiling playground v0.0.1 (/playground)
error: internal compiler error: compiler/rustc_const_eval/src/check_consts/qualifs.rs:359:13: expected ConstKind::Param or ConstKind::Value here, found UnevaluatedConst { def: DefId(0:8 ~ playground[ab6f]::arr_insert::{constant#2}), args: [N/#0, T/#1] }


thread 'rustc' panicked at compiler/rustc_const_eval/src/check_consts/qualifs.rs:359:13:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   3: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   4: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   5: rustc_middle::util::bug::bug_fmt
   6: rustc_const_eval::check_consts::qualifs::in_operand::<rustc_const_eval::check_consts::qualifs::HasMutInterior, <rustc_const_eval::check_consts::resolver::TransferFunction<rustc_const_eval::check_consts::qualifs::HasMutInterior> as rustc_middle::mir::visit::Visitor>::visit_assign::{closure#0}>.cold
   7: <rustc_const_eval::check_consts::resolver::FlowSensitiveAnalysis<rustc_const_eval::check_consts::qualifs::HasMutInterior> as rustc_mir_dataflow::framework::Analysis>::apply_primary_statement_effect
   8: <rustc_const_eval::check_consts::check::Qualifs>::has_mut_interior
   9: <rustc_const_eval::check_consts::check::Checker>::qualifs_in_return_place
  10: rustc_mir_transform::mir_const_qualif
      [... omitted 1 frame ...]
  11: rustc_mir_transform::mir_promoted
      [... omitted 1 frame ...]
  12: rustc_borrowck::mir_borrowck
      [... omitted 1 frame ...]
  13: rustc_mir_transform::mir_drops_elaborated_and_const_checked
      [... omitted 1 frame ...]
  14: rustc_mir_transform::mir_for_ctfe
      [... omitted 1 frame ...]
  15: <rustc_const_eval::interpret::eval_context::InterpCx<rustc_const_eval::const_eval::machine::CompileTimeMachine>>::init_fn_call
  16: rustc_const_eval::const_eval::eval_queries::eval_to_allocation_raw_provider
      [... omitted 1 frame ...]
  17: rustc_const_eval::const_eval::eval_queries::eval_to_const_value_raw_provider
      [... omitted 1 frame ...]
  18: rustc_hir_analysis::check_crate
  19: rustc_interface::passes::run_required_analyses
  20: rustc_interface::passes::analysis
      [... omitted 1 frame ...]
  21: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  22: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 `/playground/rustc-ice-2025-05-30T23_04_02-26.txt` to your bug report

note: compiler flags: --crate-type bin -C embed-bitcode=no -C codegen-units=1 -C debuginfo=2

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

query stack during panic:
#0 [mir_const_qualif] const checking `arr_insert`
#1 [mir_promoted] promoting constants in MIR for `arr_insert`
#2 [mir_borrowck] borrow-checking `arr_insert`
#3 [mir_drops_elaborated_and_const_checked] elaborating drops for `arr_insert`
#4 [mir_for_ctfe] caching mir of `arr_insert` for CTFE
#5 [eval_to_allocation_raw] const-evaluating + checking `MY_ARR`
#6 [eval_to_const_value_raw] simplifying constant for the type system `MY_ARR`
#7 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `playground` (bin "playground")

This is using the feature #![feature(generic_const_exprs)] !
@VirgileHenry VirgileHenry added I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. C-bug Category: This is a bug. labels May 30, 2025
@rustbot rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label May 30, 2025
@cushionbadak
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searched nightlies: from nightly-2025-01-01 to nightly-2025-05-30
regressed nightly: nightly-2025-01-29
searched commit range: 2f348cb...bf1b174
regressed commit: fdd1a3b

bisected with cargo-bisect-rustc v0.6.9

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --end=2025-05-30 --regress ice --preserve --script rustc -- 141801.rs
********************************************************************************
Regression in fdd1a3b02687817cea41f6bacae3d5fbed2b2cd0
********************************************************************************

Attempting to search unrolled perf builds
Found commits ["93c2c039", "a88bb5b0", "cfb91884", "b1ba7742", "28363945", "1f424b2f", "5fa0022a", "3b0743e7"]
installing 93c2c03916d98677da55d6befdebea7557c18c7a
rust-std-nightly-x86_64-unknown-linux-gnu: 30.21 MB / 30.21 MB [==================================] 100.00 % 12.68 MB/s testing...
RESULT: 93c2c03916d98677da55d6befdebea7557c18c7a, ===> Script did not ICE

installing a88bb5b0c4c03e32ba76f172bdf7152b029bf3b1
rust-std-nightly-x86_64-unknown-linux-gnu: 30.18 MB / 30.18 MB [==================================] 100.00 % 12.07 MB/s testing...
RESULT: a88bb5b0c4c03e32ba76f172bdf7152b029bf3b1, ===> Script did not ICE

installing cfb91884481dfe04e596629bb4754f3f50608a8a
rust-std-nightly-x86_64-unknown-linux-gnu: 30.20 MB / 30.20 MB [==================================] 100.00 % 12.36 MB/s testing...
RESULT: cfb91884481dfe04e596629bb4754f3f50608a8a, ===> Script did not ICE

installing b1ba7742813297d6f858eca03b84d41e6d67c6b4
rust-std-nightly-x86_64-unknown-linux-gnu: 30.16 MB / 30.16 MB [==================================] 100.00 % 11.81 MB/s testing...
RESULT: b1ba7742813297d6f858eca03b84d41e6d67c6b4, ===> Script found ICE

Regression in https://github.com/rust-lang-ci/rust/commit/b1ba7742813297d6f858eca03b84d41e6d67c6b4
The PR introducing the regression in this rollup is #135748: Lower index bounds checking to `PtrMetadata`, this time wit…

@cushionbadak
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Below short code shows the same ICE location:

#![allow(incomplete_features)]
#![feature(generic_const_exprs)]

trait Trait1 {
    const ASSOC_CONST: usize;
}

const fn generic_arr<Z: Trait1, T: Copy>(t: [T; Z::ASSOC_CONST]) -> T {
    t[0]
}

fn main() {}
Output 

error: internal compiler error: compiler/rustc_const_eval/src/check_consts/qualifs.rs:359:13: expected ConstKind::Param or ConstKind::Value here, found UnevaluatedConst { def: DefId(0:8 ~ gce_1[4332]::generic_arr::{constant#0}), args: [Z/#0, T/#1] }


thread 'rustc' panicked at compiler/rustc_const_eval/src/check_consts/qualifs.rs:359:13:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   3: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   4: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   5: rustc_middle::util::bug::bug_fmt
   6: rustc_const_eval::check_consts::qualifs::in_operand::<rustc_const_eval::check_consts::qualifs::HasMutInterior, <rustc_const_eval::check_consts::resolver::TransferFunction<rustc_const_eval::check_consts::qualifs::HasMutInterior> as rustc_middle::mir::visit::Visitor>::visit_assign::{closure#0}>
   7: <rustc_const_eval::check_consts::resolver::FlowSensitiveAnalysis<rustc_const_eval::check_consts::qualifs::HasMutInterior> as rustc_mir_dataflow::framework::Analysis>::apply_primary_statement_effect
   8: <rustc_const_eval::check_consts::check::Qualifs>::has_mut_interior
   9: <rustc_const_eval::check_consts::check::Checker>::qualifs_in_return_place
  10: rustc_mir_transform::mir_const_qualif
      [... omitted 1 frame ...]
  11: rustc_mir_transform::mir_promoted
      [... omitted 1 frame ...]
  12: rustc_borrowck::mir_borrowck
      [... omitted 1 frame ...]
  13: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#2}::{closure#0}>::{closure#0}
  14: rustc_interface::passes::run_required_analyses
  15: rustc_interface::passes::analysis
      [... omitted 1 frame ...]
  16: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>
  17: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 `/Users/jisukbyun/workspace/250203 scratch/rustc-ice-2025-05-31T02_19_47-32434.txt` to your bug report

query stack during panic:
#0 [mir_const_qualif] const checking `generic_arr`
#1 [mir_promoted] promoting constants in MIR for `generic_arr`
#2 [mir_borrowck] borrow-checking `generic_arr`
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 1 previous error

Notes

  • ICE location: compiler/rustc_const_eval/src/check_consts/qualifs.rs Line-359

    rust/compiler/rustc_const_eval/src/check_consts/qualifs.rs

    Lines 349 to 363 in 1bbd62e

    let uneval = match constant.const_ {
    Const::Ty(_, ct)
    if matches!(
    ct.kind(),
    ty::ConstKind::Param(_) | ty::ConstKind::Error(_) | ty::ConstKind::Value(_)
    ) =>
    {
    None
    }
    Const::Ty(_, c) => {
    bug!("expected ConstKind::Param or ConstKind::Value here, found {:?}", c)
    }
    Const::Unevaluated(uv, _) => Some(uv),
    Const::Val(..) => None,
    };

  • Originally, I found above code with min_generic_const_args, as a mutant of tests/ui/consts/const-fn.rs

    #![allow(incomplete_features)]
#![feature(min_generic_const_args)]

trait Trait1 {
    #[type_const]
    const ASSOC_CONST: usize;
}

const fn generic_arr<Z: Trait1, T: Copy>(t: [T; Z::ASSOC_CONST]) -> T {
    t[0]
}

fn main() {}

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C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
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@cushionbadak @VirgileHenry @rustbot