Open
Description
auto-reduced (treereduce-rust):
//@compile-flags: -Zlint-mir
#![feature(loop_match)]
fn main() {}
fn helper() -> u8 {
let mut state = 0u8;
#[loop_match]
'a: loop {
state = 'blk: {
match state {
_ => break 'blk state,
}
}
}
}original:
#![feature(loop_match)]
fn main() {
assert_eq!(helper(), 1);
}
fn helper() -> u8 {
let mut state = 0u8;
#[loop_match]
'a: loop {
state = 'blk: {
match state {
0 => break 'blk 1,
_ => break 'blk state,
}
}
}
}Version information
rustc 1.90.0-nightly (855e0fe46 2025-07-11)
binary: rustc
commit-hash: 855e0fe46e68d94e9f6147531b75ac2d488c548e
commit-date: 2025-07-11
host: x86_64-unknown-linux-gnu
release: 1.90.0-nightly
LLVM version: 20.1.7
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zlint-mir
Program output
warning: the feature `loop_match` is incomplete and may not be safe to use and/or cause compiler crashes
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:1:12
|
1 | #![feature(loop_match)]
| ^^^^^^^^^^
|
= note: see issue #132306 <https://github.com/rust-lang/rust/issues/132306> for more information
= note: `#[warn(incomplete_features)]` on by default
warning: unused label
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:8:5
|
8 | 'a: loop {
| ^^
|
= note: `#[warn(unused_labels)]` on by default
warning: function `helper` is never used
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:5:4
|
5 | fn helper() -> u8 {
| ^^^^^^
|
= note: `#[warn(dead_code)]` on by default
warning: 3 warnings emitted
note: no errors encountered even though delayed bugs were created
note: those delayed bugs will now be shown as internal compiler errors
error: internal compiler error: broken MIR in Item(DefId(0:4 ~ mvce[77c1]::helper)) (after pass CheckForceInline) at bb2[0]:
encountered `Assign` statement with overlapping memory
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
|
note: delayed at compiler/rustc_mir_transform/src/lint.rs:86:30
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, alloc::string::String>
4: <rustc_mir_transform::lint::Lint>::fail::<&str>
5: <rustc_mir_transform::lint::Lint as rustc_middle::mir::visit::Visitor>::visit_statement
6: rustc_mir_transform::lint::lint_body
7: rustc_mir_transform::mir_built
8: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>>
9: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
10: rustc_query_impl::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
11: rustc_mir_build::check_unsafety::check_unsafety
12: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
13: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
14: rustc_query_impl::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
15: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
16: rustc_interface::passes::analysis
17: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
18: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
19: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
20: 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}
21: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
22: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
23: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
24: std::sys::pal::unix::thread::Thread::new::thread_start
25: <unknown>
26: <unknown>
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
error: internal compiler error: broken MIR in Item(DefId(0:4 ~ mvce[77c1]::helper)) (after pass CheckCallRecursion) at bb2[0]:
encountered `Assign` statement with overlapping memory
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
|
note: delayed at compiler/rustc_mir_transform/src/lint.rs:86:30
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, alloc::string::String>
4: <rustc_mir_transform::lint::Lint>::fail::<&str>
5: <rustc_mir_transform::lint::Lint as rustc_middle::mir::visit::Visitor>::visit_statement
6: rustc_mir_transform::lint::lint_body
7: rustc_mir_transform::mir_built
8: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>>
9: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
10: rustc_query_impl::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
11: rustc_mir_build::check_unsafety::check_unsafety
12: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
13: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
14: rustc_query_impl::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
15: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
16: rustc_interface::passes::analysis
17: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
18: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
19: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
20: 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}
21: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
22: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
23: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
24: std::sys::pal::unix::thread::Thread::new::thread_start
25: <unknown>
26: <unknown>
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
error: internal compiler error: broken MIR in Item(DefId(0:4 ~ mvce[77c1]::helper)) (after pass CheckPackedRef) at bb2[0]:
encountered `Assign` statement with overlapping memory
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
|
note: delayed at compiler/rustc_mir_transform/src/lint.rs:86:30
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, alloc::string::String>
4: <rustc_mir_transform::lint::Lint>::fail::<&str>
5: <rustc_mir_transform::lint::Lint as rustc_middle::mir::visit::Visitor>::visit_statement
6: rustc_mir_transform::lint::lint_body
7: rustc_mir_transform::mir_built
8: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>>
9: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
10: rustc_query_impl::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
11: rustc_mir_build::check_unsafety::check_unsafety
12: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
13: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 0]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
14: rustc_query_impl::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
15: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
16: rustc_interface::passes::analysis
17: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
18: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
19: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
20: 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}
21: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
22: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
23: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
24: std::sys::pal::unix::thread::Thread::new::thread_start
25: <unknown>
26: <unknown>
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
< snip >
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
error: internal compiler error: broken MIR in Item(DefId(0:4 ~ mvce[77c1]::helper)) (after phase change to runtime-post-cleanup) at bb1[0]:
encountered `Assign` statement with overlapping memory
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
|
note: delayed at compiler/rustc_mir_transform/src/lint.rs:86:30
0: <rustc_errors::DiagCtxtInner>::emit_diagnostic
1: <rustc_errors::DiagCtxtHandle>::emit_diagnostic
2: <rustc_span::ErrorGuaranteed as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
3: <rustc_errors::DiagCtxtHandle>::span_delayed_bug::<rustc_span::span_encoding::Span, alloc::string::String>
4: <rustc_mir_transform::lint::Lint>::fail::<&str>
5: <rustc_mir_transform::lint::Lint as rustc_middle::mir::visit::Visitor>::visit_statement
6: rustc_mir_transform::lint::lint_body
7: rustc_mir_transform::run_analysis_to_runtime_passes
8: rustc_mir_transform::mir_drops_elaborated_and_const_checked
9: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>>
10: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_data_structures::vec_cache::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>, rustc_query_system::dep_graph::graph::DepNodeIndex>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
11: rustc_query_impl::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
12: <rustc_middle::ty::context::TyCtxt>::par_hir_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
13: rustc_interface::passes::analysis
14: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 0]>>
15: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 0]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
16: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
17: 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}
18: rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
19: std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
20: <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
21: std::sys::pal::unix::thread::Thread::new::thread_start
22: <unknown>
23: <unknown>
--> /tmp/icemaker_global_tempdir.7LzmHSjvI9Dm/rustc_testrunner_tmpdir_reporting.0dtkccEbh5V9/mvce.rs:11:33
|
11 | _ => break 'blk state,
| ^^^^^
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 1.90.0-nightly (855e0fe46 2025-07-11) running on x86_64-unknown-linux-gnu
note: compiler flags: -Z lint-mir -Z dump-mir-dir=dir
query stack during panic:
end of query stack
@rustbot label +F-loop_match
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Category: This is a bug.when you match up with someone and they really throw you for a loopIssue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️Relevant to the compiler team, which will review and decide on the PR/issue.This issue may need triage. Remove it if it has been sufficiently triaged.