ICE: mir build: scope: `index out of bounds: the len is 0 but the index is 0` #125670

matthiaskrgr · 2024-05-28T16:49:30Z

auto-reduced (treereduce-rust):

pub fn std() -> _ {
    return const {
        ({
            return ();
        })
    };
}

original:

#[non_exhaustive]
// run-pass

pub fn std() ->  _  { return  const {({ return  (
); }
)}; }

Version information

rustc 1.80.0-nightly (7717a306b 2024-05-28)
binary: rustc
commit-hash: 7717a306b2678ba9ece19b723c76a6b3a89ba931
commit-date: 2024-05-28
host: x86_64-unknown-linux-gnu
release: 1.80.0-nightly
LLVM version: 18.1.6

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

Program output

warning: unnecessary parentheses around block return value
 --> /tmp/icemaker_global_tempdir.JYB2yZP8eq2z/rustc_testrunner_tmpdir_reporting.ZJFueSdJhgaC/mvce.rs:3:9
  |
3 |         ({
  |         ^
4 |             return ();
5 |         })
  |          ^
  |
  = note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
  |
3 ~         {
4 |             return ();
5 ~         }
  |

error[E0601]: `main` function not found in crate `mvce`
 --> /tmp/icemaker_global_tempdir.JYB2yZP8eq2z/rustc_testrunner_tmpdir_reporting.ZJFueSdJhgaC/mvce.rs:7:2
  |
7 | }
  |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.JYB2yZP8eq2z/rustc_testrunner_tmpdir_reporting.ZJFueSdJhgaC/mvce.rs`

warning: unreachable expression
 --> /tmp/icemaker_global_tempdir.JYB2yZP8eq2z/rustc_testrunner_tmpdir_reporting.ZJFueSdJhgaC/mvce.rs:2:12
  |
2 |       return const {
  |  ____________^
3 | |         ({
4 | |             return ();
  | |             --------- any code following this expression is unreachable
5 | |         })
6 | |     };
  | |_____^ unreachable expression
  |
  = note: `#[warn(unreachable_code)]` on by default

error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
 --> /tmp/icemaker_global_tempdir.JYB2yZP8eq2z/rustc_testrunner_tmpdir_reporting.ZJFueSdJhgaC/mvce.rs:1:17
  |
1 | pub fn std() -> _ {
  |                 ^
  |                 |
  |                 not allowed in type signatures
  |                 help: replace with the correct return type: `()`

thread 'rustc' panicked at compiler/rustc_mir_build/src/build/scope.rs:639:58:
index out of bounds: the len is 0 but the index is 0
stack backtrace:
   0:     0x7e0919f7bae5 - std::backtrace_rs::backtrace::libunwind::trace::h8e3ec5065424d28b
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/../../backtrace/src/backtrace/libunwind.rs:116:5
   1:     0x7e0919f7bae5 - std::backtrace_rs::backtrace::trace_unsynchronized::h882cf49e59475dbc
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7e0919f7bae5 - std::sys_common::backtrace::_print_fmt::h2c337a2c4b83dc01
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7e0919f7bae5 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h5fad958b7140a660
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7e0919fcc5db - core::fmt::rt::Argument::fmt::h9f1efa968e340ff7
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/core/src/fmt/rt.rs:165:63
   5:     0x7e0919fcc5db - core::fmt::write::hc4341e028d4aa04e
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/core/src/fmt/mod.rs:1168:21
   6:     0x7e0919f7086f - std::io::Write::write_fmt::hf3dd4197197b5730
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/io/mod.rs:1835:15
   7:     0x7e0919f7b8be - std::sys_common::backtrace::_print::hee589e8f95e333af
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7e0919f7b8be - std::sys_common::backtrace::print::hc6a85e053c1c7334
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7e0919f7e2e9 - std::panicking::default_hook::{{closure}}::he62a1676f96fee54
  10:     0x7e0919f7e08a - std::panicking::default_hook::h2ceb904f12dea8be
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/panicking.rs:298:9
  11:     0x7e091678e6a0 - std[d6c1f98fb4e95ff7]::panicking::update_hook::<alloc[78b6f7e6bd40c475]::boxed::Box<rustc_driver_impl[c511ea10b869fcf7]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7e0919f7ea1b - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hc5b72f85a4688529
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/alloc/src/boxed.rs:2077:9
  13:     0x7e0919f7ea1b - std::panicking::rust_panic_with_hook::h0a690364d46daaac
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/panicking.rs:799:13
  14:     0x7e0919f7e794 - std::panicking::begin_panic_handler::{{closure}}::h9c10c03249dd0030
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/panicking.rs:664:13
  15:     0x7e0919f7bfa9 - std::sys_common::backtrace::__rust_end_short_backtrace::h599802efea5774a9
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/sys_common/backtrace.rs:171:18
  16:     0x7e0919f7e4c7 - rust_begin_unwind
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/panicking.rs:652:5
  17:     0x7e0919fc8b73 - core::panicking::panic_fmt::h16f8f3f4aae78ff5
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/core/src/panicking.rs:72:14
  18:     0x7e0919fc8d87 - core::panicking::panic_bounds_check::h601b2b36c2e3745d
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/core/src/panicking.rs:274:5
  19:     0x7e0917e79f75 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::break_scope
  20:     0x7e0917e8c214 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::stmt_expr
  21:     0x7e0917e8c1c1 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::stmt_expr
  22:     0x7e09186f5a41 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::ast_block_stmts
  23:     0x7e09186f507b - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::ast_block
  24:     0x7e0917e9e558 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::expr_into_dest
  25:     0x7e0917e961ea - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::as_temp::{closure#0}
  26:     0x7e0917e9f6fb - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::expr_into_dest
  27:     0x7e0917e9f972 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::expr_into_dest
  28:     0x7e09186f615c - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::ast_block_stmts
  29:     0x7e09186f507b - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::ast_block
  30:     0x7e0917e9e558 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::expr_into_dest
  31:     0x7e0917e9f972 - <rustc_mir_build[9415bcb3f6b13a09]::build::Builder>::expr_into_dest
  32:     0x7e0917e7481e - rustc_mir_build[9415bcb3f6b13a09]::build::mir_build
  33:     0x7e0917e712ce - rustc_query_impl[a43b8a3fae63a645]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a43b8a3fae63a645]::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle[b8101328ceeb956a]::query::erase::Erased<[u8; 8usize]>>
  34:     0x7e0917dc212e - rustc_query_system[ef4de90281b6d444]::query::plumbing::try_execute_query::<rustc_query_impl[a43b8a3fae63a645]::DynamicConfig<rustc_query_system[ef4de90281b6d444]::query::caches::VecCache<rustc_span[8ae10af61471f323]::def_id::LocalDefId, rustc_middle[b8101328ceeb956a]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[a43b8a3fae63a645]::plumbing::QueryCtxt, false>
  35:     0x7e0917dc1c4d - rustc_query_impl[a43b8a3fae63a645]::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
  36:     0x7e0917e657b0 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor>::visit_inner_body
  37:     0x7e09150a0d44 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_expr
  38:     0x7e09150a0fd3 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_expr
  39:     0x7e09150a0d44 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_expr
  40:     0x7e09183ea835 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_block
  41:     0x7e09150a2054 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_expr
  42:     0x7e09150a0fd3 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_expr
  43:     0x7e09150a0d44 - <rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::UnsafetyVisitor as rustc_middle[b8101328ceeb956a]::thir::visit::Visitor>::visit_expr
  44:     0x7e0917e62a24 - rustc_mir_build[9415bcb3f6b13a09]::check_unsafety::check_unsafety
  45:     0x7e0917e624c7 - rustc_query_impl[a43b8a3fae63a645]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a43b8a3fae63a645]::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle[b8101328ceeb956a]::query::erase::Erased<[u8; 0usize]>>
  46:     0x7e0917e615d4 - rustc_query_system[ef4de90281b6d444]::query::plumbing::try_execute_query::<rustc_query_impl[a43b8a3fae63a645]::DynamicConfig<rustc_query_system[ef4de90281b6d444]::query::caches::VecCache<rustc_span[8ae10af61471f323]::def_id::LocalDefId, rustc_middle[b8101328ceeb956a]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[a43b8a3fae63a645]::plumbing::QueryCtxt, false>
  47:     0x7e0917e61207 - rustc_query_impl[a43b8a3fae63a645]::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
  48:     0x7e0918568e5b - rustc_interface[3320d9bec8b3433a]::passes::analysis
  49:     0x7e0918567f5b - rustc_query_impl[a43b8a3fae63a645]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a43b8a3fae63a645]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[b8101328ceeb956a]::query::erase::Erased<[u8; 1usize]>>
  50:     0x7e091899c225 - rustc_query_system[ef4de90281b6d444]::query::plumbing::try_execute_query::<rustc_query_impl[a43b8a3fae63a645]::DynamicConfig<rustc_query_system[ef4de90281b6d444]::query::caches::SingleCache<rustc_middle[b8101328ceeb956a]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a43b8a3fae63a645]::plumbing::QueryCtxt, false>
  51:     0x7e091899bf8f - rustc_query_impl[a43b8a3fae63a645]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  52:     0x7e09187f9f5c - rustc_interface[3320d9bec8b3433a]::interface::run_compiler::<core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>, rustc_driver_impl[c511ea10b869fcf7]::run_compiler::{closure#0}>::{closure#1}
  53:     0x7e09187c0609 - std[d6c1f98fb4e95ff7]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[3320d9bec8b3433a]::util::run_in_thread_with_globals<rustc_interface[3320d9bec8b3433a]::util::run_in_thread_pool_with_globals<rustc_interface[3320d9bec8b3433a]::interface::run_compiler<core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>, rustc_driver_impl[c511ea10b869fcf7]::run_compiler::{closure#0}>::{closure#1}, core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>>::{closure#0}, core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>>
  54:     0x7e09187c03b2 - <<std[d6c1f98fb4e95ff7]::thread::Builder>::spawn_unchecked_<rustc_interface[3320d9bec8b3433a]::util::run_in_thread_with_globals<rustc_interface[3320d9bec8b3433a]::util::run_in_thread_pool_with_globals<rustc_interface[3320d9bec8b3433a]::interface::run_compiler<core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>, rustc_driver_impl[c511ea10b869fcf7]::run_compiler::{closure#0}>::{closure#1}, core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>>::{closure#0}, core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5e8023d66ded8339]::result::Result<(), rustc_span[8ae10af61471f323]::ErrorGuaranteed>>::{closure#2} as core[5e8023d66ded8339]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  55:     0x7e0919f889eb - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::ha3f12f701ab217ba
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/alloc/src/boxed.rs:2063:9
  56:     0x7e0919f889eb - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hbabc732018734ba3
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/alloc/src/boxed.rs:2063:9
  57:     0x7e0919f889eb - std::sys::pal::unix::thread::Thread::new::thread_start::h25b845304e0b166b
                               at /rustc/7717a306b2678ba9ece19b723c76a6b3a89ba931/library/std/src/sys/pal/unix/thread.rs:108:17
  58:     0x7e09134aa1cf - <unknown>
  59:     0x7e091352b6ec - <unknown>
  60:                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: please make sure that you have updated to the latest nightly

note: rustc 1.80.0-nightly (7717a306b 2024-05-28) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [mir_built] building MIR for `std::{constant#0}`
#1 [check_unsafety] unsafety-checking `std`
end of query stack
error: aborting due to 2 previous errors; 2 warnings emitted

Some errors have detailed explanations: E0121, E0601.
For more information about an error, try `rustc --explain E0121`.

The text was updated successfully, but these errors were encountered:

theemathas · 2024-05-29T09:57:26Z

Minimized:

fn foo() {
    const { return }
}

Variations that also cause ICEs of varying kinds:

fn foo() {
    'a: {
        const { break 'a }
    }
}

fn foo() {
    loop {
        const { break }
    }
}

fn foo() {
    'a: {
        const { continue 'a }
    }
}

fn foo() {
    loop {
        const { continue }
    }
}

async fn foo() {
    const { async {}.await }
}

fn foo() {
    let x = 1;
    const { &x };
}

Noratrieb · 2024-05-29T10:59:45Z

cc @nbdd0121 that's pretty bad... the fix for that should probably be backported or maybe even delaying the stabilization for one release? no strong opinion.

nbdd0121 · 2024-05-29T11:04:40Z

These examples all generate correct errors on beta (which contains inline const stablisation) but ICE on nightly. Looks like something else breaks these?

nbdd0121 · 2024-05-29T11:07:54Z

@rustbot label: +E-needs-bisection

apiraino · 2024-05-29T15:27:49Z

I've tried bisecting a couple of them and they all both point to 7717a30 cc @oli-obk @nnethercote

@rustbot label -E-needs-bisection

apiraino · 2024-05-29T15:34:43Z

WG-prioritization assigning priority (Zulip discussion).

Being easy to be triggered even if for now only on nightly.

@rustbot label -I-prioritize +P-high

matthiaskrgr 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 28, 2024

rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label May 28, 2024

rustbot added the E-needs-bisection Call for participation: This issue needs bisection: https://github.com/rust-lang/cargo-bisect-rustc label May 29, 2024

rustbot removed the E-needs-bisection Call for participation: This issue needs bisection: https://github.com/rust-lang/cargo-bisect-rustc label May 29, 2024

rustbot added P-high High priority and removed I-prioritize Issue: Indicates that prioritization has been requested for this issue. labels May 29, 2024

Noratrieb mentioned this issue May 29, 2024

Reintroduce name resolution check for trying to access locals from an inline const #125705

Merged

oli-obk self-assigned this May 29, 2024

workingjubilee added the S-has-mcve Status: A Minimal Complete and Verifiable Example has been found for this issue label May 31, 2024

oli-obk mentioned this issue May 31, 2024

Create const blocks on the fly during typeck instead of waiting until writeback. #125806

Closed

matthiaskrgr mentioned this issue Jun 1, 2024

ICE: mir_const_qualif: index out of bounds: the len is 0 but the index is 0 #125837

Closed

matthiaskrgr added the E-needs-test Call for participation: An issue has been fixed and does not reproduce, but no test has been added. label Jun 8, 2024

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ICE: mir build: scope: `index out of bounds: the len is 0 but the index is 0` #125670

ICE: mir build: scope: `index out of bounds: the len is 0 but the index is 0` #125670

matthiaskrgr commented May 28, 2024

theemathas commented May 29, 2024 •

edited

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Noratrieb commented May 29, 2024

nbdd0121 commented May 29, 2024 •

edited

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nbdd0121 commented May 29, 2024

apiraino commented May 29, 2024

apiraino commented May 29, 2024

ICE: mir build: scope: index out of bounds: the len is 0 but the index is 0 #125670

ICE: mir build: scope: index out of bounds: the len is 0 but the index is 0 #125670

Comments

matthiaskrgr commented May 28, 2024

theemathas commented May 29, 2024 • edited Loading

Noratrieb commented May 29, 2024

nbdd0121 commented May 29, 2024 • edited Loading

nbdd0121 commented May 29, 2024

apiraino commented May 29, 2024

apiraino commented May 29, 2024

ICE: mir build: scope: `index out of bounds: the len is 0 but the index is 0` #125670

ICE: mir build: scope: `index out of bounds: the len is 0 but the index is 0` #125670

theemathas commented May 29, 2024 •

edited

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nbdd0121 commented May 29, 2024 •

edited

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