ICE: compute_type_of_item: unexpected item type: Trait

[matthiaskrgr]

snippet:

//@compile-flags: -Clink-dead-code=true
trait SelfStruct<'x, 's, T>
where
    [T; (|| {}, 1).1]: Copy,
{
}

pub fn main() {}

Version information

rustc 1.86.0-nightly (627513a76 2025-01-12)
binary: rustc
commit-hash: 627513a764a696b59bb2679cc1731a197a088a1d
commit-date: 2025-01-12
host: x86_64-unknown-linux-gnu
release: 1.86.0-nightly
LLVM version: 19.1.6

Possibly related line of code:

rust/compiler/rustc_hir_analysis/src/collect/type_of.rs

Lines 308 to 320 in 627513a

	| ItemKind::Macro(..)
	| ItemKind::Mod(..)
	| ItemKind::ForeignMod { .. }
	| ItemKind::GlobalAsm(..)
	| ItemKind::ExternCrate(..)
	| ItemKind::Use(..) => {
	span_bug!(item.span, "compute_type_of_item: unexpected item type: {:?}", item.kind);
	}
	},
	Node::OpaqueTy(..) => tcx.type_of_opaque(def_id).map_or_else(
	|CyclePlaceholder(guar)| Ty::new_error(tcx, guar),
	|ty| ty.instantiate_identity(),

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Clink-dead-code=true

Program output

warning: trait `SelfStruct` is never used
 --> /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:1:7
  |
1 | trait SelfStruct<'x, 's, T>
  |       ^^^^^^^^^^
  |
  = note: `#[warn(dead_code)]` on by default

error: internal compiler error: compiler/rustc_hir_analysis/src/collect/type_of.rs:314:17: compute_type_of_item: unexpected item type: Trait(No, Safe, Generics { params: [GenericParam { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).15), def_id: DefId(0:4 ~ mvce[0784]::SelfStruct::'x), name: Plain('x#0), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:1:18: 1:20 (#0), pure_wrt_drop: false, kind: Lifetime { kind: Explicit }, colon_span: None, source: Generics }, GenericParam { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).16), def_id: DefId(0:5 ~ mvce[0784]::SelfStruct::'s), name: Plain('s#0), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:1:22: 1:24 (#0), pure_wrt_drop: false, kind: Lifetime { kind: Explicit }, colon_span: None, source: Generics }, GenericParam { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).17), def_id: DefId(0:6 ~ mvce[0784]::SelfStruct::T), name: Plain(T#0), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:1:26: 1:27 (#0), pure_wrt_drop: false, kind: Type { default: None, synthetic: false }, colon_span: None, source: Generics }], predicates: [WherePredicate { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).1), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:5: 3:28 (#0), kind: BoundPredicate(WhereBoundPredicate { origin: WhereClause, bound_generic_params: [], bounded_ty: Ty { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).12), kind: Array(Ty { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).2), kind: Path(Resolved(None, Path { span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:6: 3:7 (#0), res: Def(TyParam, DefId(0:6 ~ mvce[0784]::SelfStruct::T)), segments: [PathSegment { ident: T#0, hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).3), res: Def(TyParam, DefId(0:6 ~ mvce[0784]::SelfStruct::T)), args: None, infer_args: false }] })), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:6: 3:7 (#0) }, ConstArg { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).11), kind: Anon(AnonConst { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).4), def_id: DefId(0:7 ~ mvce[0784]::SelfStruct::{constant#0}), body: BodyId { hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).5) }, span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:9: 3:21 (#0) }) }), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:5: 3:22 (#0) }, bounds: [Trait(PolyTraitRef { bound_generic_params: [], modifiers: TraitBoundModifiers { constness: Never, polarity: Positive }, trait_ref: TraitRef { path: Path { span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:24: 3:28 (#0), res: Def(Trait, DefId(2:3495 ~ core[0a3a]::marker::Copy)), segments: [PathSegment { ident: Copy#0, hir_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).13), res: Def(Trait, DefId(2:3495 ~ core[0a3a]::marker::Copy)), args: None, infer_args: false }] }, hir_ref_id: HirId(DefId(0:3 ~ mvce[0784]::SelfStruct).14) }, span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:3:24: 3:28 (#0) })] }) }], has_where_clause_predicates: true, where_clause_span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:2:1: 3:29 (#0), span: /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:1:17: 1:28 (#0) }, [], [])
 --> /tmp/icemaker_global_tempdir.DEnKVgcGaF35/rustc_testrunner_tmpdir_reporting.wm567l8VVNDr/mvce.rs:1:1
  |
1 | / trait SelfStruct<'x, 's, T>
2 | | where
3 | |     [T; (|| {}, 1).1]: Copy,
4 | | {
5 | | }
  | |_^


thread 'rustc' panicked at compiler/rustc_hir_analysis/src/collect/type_of.rs:314:17:
Box<dyn Any>
stack backtrace:
   0:     0x74cf6b6f6cba - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hb6d52abf03d3c762
   1:     0x74cf6be12d66 - core::fmt::write::ha1f096bf27753534
   2:     0x74cf6cda72d1 - std::io::Write::write_fmt::h7b63b7192c8b84e8
   3:     0x74cf6b6f6b12 - std::sys::backtrace::BacktraceLock::print::he1317dcd3671a83c
   4:     0x74cf6b6f90b7 - std::panicking::default_hook::{{closure}}::h5104547d98fde4b9
   5:     0x74cf6b6f8ea0 - std::panicking::default_hook::h00c5a74868336544
   6:     0x74cf6a85ef68 - std[66958f67114116ef]::panicking::update_hook::<alloc[73a44396601e81ad]::boxed::Box<rustc_driver_impl[c9f89440d3758e47]::install_ice_hook::{closure#1}>>::{closure#0}
   7:     0x74cf6b6f9903 - std::panicking::rust_panic_with_hook::hffe642292ec7a3ed
   8:     0x74cf6a897db1 - std[66958f67114116ef]::panicking::begin_panic::<rustc_errors[2c74e16010a12992]::ExplicitBug>::{closure#0}
   9:     0x74cf6a88ccb6 - std[66958f67114116ef]::sys::backtrace::__rust_end_short_backtrace::<std[66958f67114116ef]::panicking::begin_panic<rustc_errors[2c74e16010a12992]::ExplicitBug>::{closure#0}, !>
  10:     0x74cf6a8897c9 - std[66958f67114116ef]::panicking::begin_panic::<rustc_errors[2c74e16010a12992]::ExplicitBug>
  11:     0x74cf6a8a1ce1 - <rustc_errors[2c74e16010a12992]::diagnostic::BugAbort as rustc_errors[2c74e16010a12992]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x74cf6adf886c - <rustc_errors[2c74e16010a12992]::DiagCtxtHandle>::span_bug::<rustc_span[d3aaf222917fc9d0]::span_encoding::Span, alloc[73a44396601e81ad]::string::String>
  13:     0x74cf6ae7d5d7 - rustc_middle[3aac817982ce6052]::util::bug::opt_span_bug_fmt::<rustc_span[d3aaf222917fc9d0]::span_encoding::Span>::{closure#0}
  14:     0x74cf6ae62f1a - rustc_middle[3aac817982ce6052]::ty::context::tls::with_opt::<rustc_middle[3aac817982ce6052]::util::bug::opt_span_bug_fmt<rustc_span[d3aaf222917fc9d0]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  15:     0x74cf6ae62dab - rustc_middle[3aac817982ce6052]::ty::context::tls::with_context_opt::<rustc_middle[3aac817982ce6052]::ty::context::tls::with_opt<rustc_middle[3aac817982ce6052]::util::bug::opt_span_bug_fmt<rustc_span[d3aaf222917fc9d0]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  16:     0x74cf69846017 - rustc_middle[3aac817982ce6052]::util::bug::span_bug_fmt::<rustc_span[d3aaf222917fc9d0]::span_encoding::Span>
  17:     0x74cf6bed600a - rustc_hir_analysis[6ef5ea017ebe40aa]::collect::type_of::type_of
  18:     0x74cf6becf7f8 - rustc_query_impl[dddd50ae2b86f84d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[dddd50ae2b86f84d]::query_impl::type_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3aac817982ce6052]::query::erase::Erased<[u8; 8usize]>>
  19:     0x74cf6bece59f - rustc_query_system[6587ccb57284e1c7]::query::plumbing::try_execute_query::<rustc_query_impl[dddd50ae2b86f84d]::DynamicConfig<rustc_query_system[6587ccb57284e1c7]::query::caches::DefIdCache<rustc_middle[3aac817982ce6052]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[dddd50ae2b86f84d]::plumbing::QueryCtxt, false>
  20:     0x74cf6bece12b - rustc_query_impl[dddd50ae2b86f84d]::query_impl::type_of::get_query_non_incr::__rust_end_short_backtrace
  21:     0x74cf6c945630 - rustc_symbol_mangling[cd10110488156193]::legacy::mangle
  22:     0x74cf6c941187 - rustc_symbol_mangling[cd10110488156193]::symbol_name_provider
  23:     0x74cf6c94092a - rustc_query_impl[dddd50ae2b86f84d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[dddd50ae2b86f84d]::query_impl::symbol_name::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3aac817982ce6052]::query::erase::Erased<[u8; 16usize]>>
  24:     0x74cf6c93f8b7 - rustc_query_system[6587ccb57284e1c7]::query::plumbing::try_execute_query::<rustc_query_impl[dddd50ae2b86f84d]::DynamicConfig<rustc_query_system[6587ccb57284e1c7]::query::caches::DefaultCache<rustc_middle[3aac817982ce6052]::ty::instance::Instance, rustc_middle[3aac817982ce6052]::query::erase::Erased<[u8; 16usize]>>, false, false, false>, rustc_query_impl[dddd50ae2b86f84d]::plumbing::QueryCtxt, false>
  25:     0x74cf6c93f522 - rustc_query_impl[dddd50ae2b86f84d]::query_impl::symbol_name::get_query_non_incr::__rust_end_short_backtrace
  26:     0x74cf6c93b302 - <rustc_middle[3aac817982ce6052]::mir::mono::MonoItem>::symbol_name
  27:     0x74cf6c93adfd - rustc_monomorphize[1c1f6e9040afc7a4]::partitioning::assert_symbols_are_distinct::<core[a3a276ad4f05d2a]::slice::iter::Iter<rustc_middle[3aac817982ce6052]::mir::mono::MonoItem>>
  28:     0x74cf6c869579 - rustc_monomorphize[1c1f6e9040afc7a4]::partitioning::collect_and_partition_mono_items
  29:     0x74cf6cdcc9d6 - rustc_query_impl[dddd50ae2b86f84d]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[dddd50ae2b86f84d]::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3aac817982ce6052]::query::erase::Erased<[u8; 24usize]>>
  30:     0x74cf6cdcc9b7 - <rustc_query_impl[dddd50ae2b86f84d]::query_impl::collect_and_partition_mono_items::dynamic_query::{closure#2} as core[a3a276ad4f05d2a]::ops::function::FnOnce<(rustc_middle[3aac817982ce6052]::ty::context::TyCtxt, ())>>::call_once
  31:     0x74cf6cdcc53c - rustc_query_system[6587ccb57284e1c7]::query::plumbing::try_execute_query::<rustc_query_impl[dddd50ae2b86f84d]::DynamicConfig<rustc_query_system[6587ccb57284e1c7]::query::caches::SingleCache<rustc_middle[3aac817982ce6052]::query::erase::Erased<[u8; 24usize]>>, false, false, false>, rustc_query_impl[dddd50ae2b86f84d]::plumbing::QueryCtxt, false>
  32:     0x74cf6cdcc234 - rustc_query_impl[dddd50ae2b86f84d]::query_impl::collect_and_partition_mono_items::get_query_non_incr::__rust_end_short_backtrace
  33:     0x74cf6ce8daa0 - <rustc_codegen_llvm[d754e186fb816fa0]::LlvmCodegenBackend as rustc_codegen_ssa[89dde8d707ccbd3c]::traits::backend::CodegenBackend>::codegen_crate
  34:     0x74cf6ce42ee4 - <rustc_interface[9c0c46cd854ea960]::queries::Linker>::codegen_and_build_linker
  35:     0x74cf6ce38852 - rustc_interface[9c0c46cd854ea960]::passes::create_and_enter_global_ctxt::<core[a3a276ad4f05d2a]::option::Option<rustc_interface[9c0c46cd854ea960]::queries::Linker>, rustc_driver_impl[c9f89440d3758e47]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
  36:     0x74cf6ce1af96 - rustc_interface[9c0c46cd854ea960]::interface::run_compiler::<(), rustc_driver_impl[c9f89440d3758e47]::run_compiler::{closure#0}>::{closure#1}
  37:     0x74cf6cc7c511 - std[66958f67114116ef]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[9c0c46cd854ea960]::util::run_in_thread_with_globals<rustc_interface[9c0c46cd854ea960]::util::run_in_thread_pool_with_globals<rustc_interface[9c0c46cd854ea960]::interface::run_compiler<(), rustc_driver_impl[c9f89440d3758e47]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
  38:     0x74cf6cc7c9c4 - <<std[66958f67114116ef]::thread::Builder>::spawn_unchecked_<rustc_interface[9c0c46cd854ea960]::util::run_in_thread_with_globals<rustc_interface[9c0c46cd854ea960]::util::run_in_thread_pool_with_globals<rustc_interface[9c0c46cd854ea960]::interface::run_compiler<(), rustc_driver_impl[c9f89440d3758e47]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[a3a276ad4f05d2a]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  39:     0x74cf6cc7df6f - std::sys::pal::unix::thread::Thread::new::thread_start::h11552343380d0134
  40:     0x74cf6705f39d - <unknown>
  41:     0x74cf670e449c - <unknown>
  42:                0x0 - <unknown>

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: rustc 1.86.0-nightly (627513a76 2025-01-12) running on x86_64-unknown-linux-gnu

note: compiler flags: -C link-dead-code=true -Z dump-mir-dir=dir

query stack during panic:
#0 [type_of] computing type of `SelfStruct`
#1 [symbol_name] computing the symbol for `SelfStruct::{constant#0}::{closure#0}`
#2 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
error: aborting due to 1 previous error; 1 warning emitted

[matthiaskrgr]

this compiled before
regression in #135314 cc @compiler-errors

[matthiaskrgr]

smaller

trait A<T>
where
    [T; (|| {}, 1).1]: Sized,
{
}