ICE: `b.index() < self.live_nodes`

[matthiaskrgr]

auto-reduced (treereduce-rust):

fn main() {
    match () {
        _ => 'b: {
            continue 'b;
        }
    }
}

original:

fn main() {
    struct Foo { x: isize }
    match (Foo { x: 10 }) {
        Foo { ref x: ref x } => {}, //~ ERROR expected `,`
        _ => {
    'b: {
        continue 'b; //~ ERROR `continue` pointing to a labeled block
    }
}
    }
}

Version information

rustc 1.78.0-nightly (26cd5d862 2024-02-25)
binary: rustc
commit-hash: 26cd5d862e22c013ecb3396b177d3af80e95c836
commit-date: 2024-02-25
host: x86_64-unknown-linux-gnu
release: 1.78.0-nightly
LLVM version: 18.1.0

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error[E0696]: `continue` pointing to a labeled block
 --> /tmp/icemaker_global_tempdir.5rkJyKlhWneU/rustc_testrunner_tmpdir_reporting.DS0B2iBa0Zdm/mvce.rs:4:13
  |
3 |           _ => 'b: {
  |  ______________-
4 | |             continue 'b;
  | |             ^^^^^^^^^^^ labeled blocks cannot be `continue`'d
5 | |         }
  | |_________- labeled block the `continue` points to

thread 'rustc' panicked at compiler/rustc_passes/src/liveness/rwu_table.rs:62:9:
assertion failed: b.index() < self.live_nodes
stack backtrace:
   0:     0x7f1597b8ca06 - std::backtrace_rs::backtrace::libunwind::trace::h2b754d54d1bde505
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f1597b8ca06 - std::backtrace_rs::backtrace::trace_unsynchronized::h543e1ca101948fd5
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f1597b8ca06 - std::sys_common::backtrace::_print_fmt::h530a113cbf476cc2
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f1597b8ca06 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hdaaebae0c7e457dd
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f1597bdd98c - core::fmt::rt::Argument::fmt::h986a5c541218a991
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/core/src/fmt/rt.rs:142:9
   5:     0x7f1597bdd98c - core::fmt::write::h0480b093981ac277
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f1597b813cf - std::io::Write::write_fmt::he3dd140cfd4aef89
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/io/mod.rs:1846:15
   7:     0x7f1597b8c7b4 - std::sys_common::backtrace::_print::hdac374456098a97e
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f1597b8c7b4 - std::sys_common::backtrace::print::ha7f20ab884506926
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f1597b8f4fb - std::panicking::default_hook::{{closure}}::h300a405277525f5d
  10:     0x7f1597b8f249 - std::panicking::default_hook::hde1c193b2da6a81c
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/panicking.rs:292:9
  11:     0x7f159aa8892c - std[555420183d371a7f]::panicking::update_hook::<alloc[b9bf11d30073d6dd]::boxed::Box<rustc_driver_impl[633500a3532990b7]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f1597b8fc60 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h68a9e4d741c266fd
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/alloc/src/boxed.rs:2030:9
  13:     0x7f1597b8fc60 - std::panicking::rust_panic_with_hook::h8ba518db0741b55a
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/panicking.rs:783:13
  14:     0x7f1597b8f969 - std::panicking::begin_panic_handler::{{closure}}::ha55fc9dde68cbcf7
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/panicking.rs:649:13
  15:     0x7f1597b8cee6 - std::sys_common::backtrace::__rust_end_short_backtrace::h6838138199d9ac3e
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7f1597b8f6d4 - rust_begin_unwind
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/panicking.rs:645:5
  17:     0x7f1597bd9ea5 - core::panicking::panic_fmt::hb9e36ea683b16cf8
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/core/src/panicking.rs:72:14
  18:     0x7f1597bd9f63 - core::panicking::panic::h7d14ca7420fbd005
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/core/src/panicking.rs:144:5
  19:     0x7f159c6ea24a - <rustc_passes[c523e52c217c408]::liveness::Liveness>::propagate_through_expr
  20:     0x7f159c6e710b - <rustc_passes[c523e52c217c408]::liveness::Liveness>::propagate_through_block
  21:     0x7f159c64cfe6 - rustc_passes[c523e52c217c408]::liveness::check_liveness
  22:     0x7f159c64c727 - rustc_query_impl[2c9e1b0525c9d953]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2c9e1b0525c9d953]::query_impl::check_liveness::dynamic_query::{closure#2}::{closure#0}, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 0usize]>>
  23:     0x7f159c64b888 - rustc_query_system[dfd6c8aac03f3724]::query::plumbing::try_execute_query::<rustc_query_impl[2c9e1b0525c9d953]::DynamicConfig<rustc_query_system[dfd6c8aac03f3724]::query::caches::VecCache<rustc_span[dc6b5ece0d38defd]::def_id::LocalDefId, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[2c9e1b0525c9d953]::plumbing::QueryCtxt, false>
  24:     0x7f159c64b4bf - rustc_query_impl[2c9e1b0525c9d953]::query_impl::check_liveness::get_query_non_incr::__rust_end_short_backtrace
  25:     0x7f159c49ba5a - rustc_mir_build[e37b6b80862e17d9]::build::mir_built
  26:     0x7f159c49b7ab - rustc_query_impl[2c9e1b0525c9d953]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2c9e1b0525c9d953]::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 8usize]>>
  27:     0x7f159c10e570 - rustc_query_system[dfd6c8aac03f3724]::query::plumbing::try_execute_query::<rustc_query_impl[2c9e1b0525c9d953]::DynamicConfig<rustc_query_system[dfd6c8aac03f3724]::query::caches::VecCache<rustc_span[dc6b5ece0d38defd]::def_id::LocalDefId, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[2c9e1b0525c9d953]::plumbing::QueryCtxt, false>
  28:     0x7f159c10dfcc - rustc_query_impl[2c9e1b0525c9d953]::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
  29:     0x7f159c291b5b - rustc_mir_build[e37b6b80862e17d9]::check_unsafety::check_unsafety
  30:     0x7f159c291977 - rustc_query_impl[2c9e1b0525c9d953]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2c9e1b0525c9d953]::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 0usize]>>
  31:     0x7f159c64b80a - rustc_query_system[dfd6c8aac03f3724]::query::plumbing::try_execute_query::<rustc_query_impl[2c9e1b0525c9d953]::DynamicConfig<rustc_query_system[dfd6c8aac03f3724]::query::caches::VecCache<rustc_span[dc6b5ece0d38defd]::def_id::LocalDefId, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[2c9e1b0525c9d953]::plumbing::QueryCtxt, false>
  32:     0x7f159c64b54f - rustc_query_impl[2c9e1b0525c9d953]::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
  33:     0x7f159ca05bab - rustc_interface[27abfdff6e6b27c2]::passes::analysis
  34:     0x7f159ca05619 - rustc_query_impl[2c9e1b0525c9d953]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[2c9e1b0525c9d953]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 1usize]>>
  35:     0x7f159cb1f8e5 - rustc_query_system[dfd6c8aac03f3724]::query::plumbing::try_execute_query::<rustc_query_impl[2c9e1b0525c9d953]::DynamicConfig<rustc_query_system[dfd6c8aac03f3724]::query::caches::SingleCache<rustc_middle[73325823477bd615]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[2c9e1b0525c9d953]::plumbing::QueryCtxt, false>
  36:     0x7f159cb1f649 - rustc_query_impl[2c9e1b0525c9d953]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  37:     0x7f159cb2eb16 - rustc_interface[27abfdff6e6b27c2]::interface::run_compiler::<core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>, rustc_driver_impl[633500a3532990b7]::run_compiler::{closure#0}>::{closure#0}
  38:     0x7f159cdc8cc5 - std[555420183d371a7f]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[27abfdff6e6b27c2]::util::run_in_thread_with_globals<rustc_interface[27abfdff6e6b27c2]::util::run_in_thread_pool_with_globals<rustc_interface[27abfdff6e6b27c2]::interface::run_compiler<core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>, rustc_driver_impl[633500a3532990b7]::run_compiler::{closure#0}>::{closure#0}, core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>>::{closure#0}, core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>>
  39:     0x7f159cdc8af2 - <<std[555420183d371a7f]::thread::Builder>::spawn_unchecked_<rustc_interface[27abfdff6e6b27c2]::util::run_in_thread_with_globals<rustc_interface[27abfdff6e6b27c2]::util::run_in_thread_pool_with_globals<rustc_interface[27abfdff6e6b27c2]::interface::run_compiler<core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>, rustc_driver_impl[633500a3532990b7]::run_compiler::{closure#0}>::{closure#0}, core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>>::{closure#0}, core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[421030ac42e8f54b]::result::Result<(), rustc_span[dc6b5ece0d38defd]::ErrorGuaranteed>>::{closure#1} as core[421030ac42e8f54b]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  40:     0x7f1597b99635 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h176656733d324092
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/alloc/src/boxed.rs:2016:9
  41:     0x7f1597b99635 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h2cb067df8c4b40c7
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/alloc/src/boxed.rs:2016:9
  42:     0x7f1597b99635 - std::sys::pal::unix::thread::Thread::new::thread_start::h9c4fa792b58c770f
                               at /rustc/26cd5d862e22c013ecb3396b177d3af80e95c836/library/std/src/sys/pal/unix/thread.rs:108:17
  43:     0x7f159798155a - <unknown>
  44:     0x7f15979fea3c - <unknown>
  45:                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: rustc 1.78.0-nightly (26cd5d862 2024-02-25) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [check_liveness] checking liveness of variables in `main`
#1 [mir_built] building MIR for `main`
#2 [check_unsafety] unsafety-checking `main`
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0696`.

[What42Pizza]

I've also gotten this error, and I've found another way to get it:

fn main() {
    'a: {
        for _ in 0..0 {
            continue 'a;
        }
    }
}

[dotjpg3141]

Got the same panic for this code:

fn main() {
    let i = 5;
    'a: {
        continue 'a;
    }
}

[jieyouxu]

Looks like improper error tainting

[jieyouxu]

AAnother case: #127362.