ICE: tcx: index out of bounds

[matthiaskrgr]

auto-reduced (treereduce-rust):

struct Foo<T>([T; 2]);

impl<T: Default + Copy> Default for Foo<T> {
    fn default(&mut self) -> Self {
        Foo([Default::default(); 2])
    }
}

fn field_array() {
    let a: i32;
    let b;
    Foo([a, b]) = Default::default();
}

original code

original:

#![allow(unused_variables)]

use std::array::TryFromSliceError;
use std::convert::TryInto;

struct Zeroes;
impl Into<[usize; 2]> for Zeroes {
    fn into(self) -> [usize; 2] {
        [0; 2]
    }
}
impl Into<[usize; 3]> for Zeroes {
    fn into(self) -> [usize; 3] {
        [0; 3]
    }
}
impl Into<[Option<Box<u8>>; 48]> for Zeroes {
    fn into(self) -> [usize; 4] {
        [0; 4]
    }
}

fn zeroes_into() {
    let [a, b, c] = Zeroes.into();
    let [d, e, f]: [_; 3] = Zeroes.into();
}

fn array_try_from(x: &[usize]) -> Result<usize, TryFromSliceError> {
    let [a, b] = d.succ().isoweekdate().1()?;
    Ok(a + b)
}

fn destructuring_assignment() {
    let a: i32;
    let b;
    [a, b] = Default::default();
}

fn test_nested_array() {
    let a: [_; 3];
    let b;
    //~^ ERROR type annotations needed
    [a, b] = Default::default();
}

fn test_nested_array_type_hint() {
    let a: [_; 3];
    let b;
    [a, b] = Default::default();
    let _: i32 = b[1];
}

fn test_working_nested_array() {
    let a: i32;
    [[a, _, _], _, _] = Default::default();
}

struct Foo<T>([T; 2]);

impl<T: Default + Copy> Default for Foo<T> {
    fn default(&mut self, (_,): (T,)) -> Self {
        Foo([Default::default(); 2])
    }
}

fn field_array() {
    let a: i32;
    let b;
    Foo([a, b]) = Default::default();
}

fn main() {}

Version information

rustc 1.82.0-nightly (e5b3e68ab 2024-08-13)
binary: rustc
commit-hash: e5b3e68abf170556b9d56c6f9028318e53c9f06b
commit-date: 2024-08-13
host: x86_64-unknown-linux-gnu
release: 1.82.0-nightly
LLVM version: 19.1.0

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zvalidate-mir -Zinline-mir=yes

Program output

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs:13:2
   |
13 | }
   |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs`

error[E0185]: method `default` has a `&mut self` declaration in the impl, but not in the trait
 --> /tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs:4:5
  |
4 |     fn default(&mut self) -> Self {
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&mut self` used in impl
  |
  = note: `default` from trait: `fn() -> Self`

warning: variable `a` is assigned to, but never used
  --> /tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs:10:9
   |
10 |     let a: i32;
   |         ^
   |
   = note: consider using `_a` instead
   = note: `#[warn(unused_variables)]` on by default

warning: variable `b` is assigned to, but never used
  --> /tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs:11:9
   |
11 |     let b;
   |         ^
   |
   = note: consider using `_b` instead

warning: value assigned to `a` is never read
  --> /tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs:12:10
   |
12 |     Foo([a, b]) = Default::default();
   |          ^
   |
   = help: maybe it is overwritten before being read?
   = note: `#[warn(unused_assignments)]` on by default

warning: value assigned to `b` is never read
  --> /tmp/icemaker_global_tempdir.ufzSPaPZx9Up/rustc_testrunner_tmpdir_reporting.doFpl6Nkk2VR/mvce.rs:12:13
   |
12 |     Foo([a, b]) = Default::default();
   |             ^
   |
   = help: maybe it is overwritten before being read?

thread 'rustc' panicked at /rustc/e5b3e68abf170556b9d56c6f9028318e53c9f06b/compiler/rustc_middle/src/mir/tcx.rs:131:61:
index out of bounds: the len is 11 but the index is 11
stack backtrace:
   0:     0x71a82a9be6ad - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hd8cddadc2f1356ba
   1:     0x71a82b2049ef - core::fmt::write::hf4a4be5c7aa55e78
   2:     0x71a82c1c5511 - std::io::Write::write_fmt::h937572d76c9c7a9b
   3:     0x71a82a9c0d8b - std::panicking::default_hook::{{closure}}::h663ce340916a5919
   4:     0x71a82a9c09fe - std::panicking::default_hook::h5cb270171c609139
   5:     0x71a829b4b6c9 - std[c898dee7a900a719]::panicking::update_hook::<alloc[f79bb38400b26b08]::boxed::Box<rustc_driver_impl[7bc6674bbf855457]::install_ice_hook::{closure#0}>>::{closure#0}
   6:     0x71a82a9c16a7 - std::panicking::rust_panic_with_hook::h527dcb0b253a1e21
   7:     0x71a82a9c1367 - std::panicking::begin_panic_handler::{{closure}}::hbc0a646a011dd19f
   8:     0x71a82a9beb69 - std::sys::backtrace::__rust_end_short_backtrace::h44802a1bb26a785a
   9:     0x71a82a9c1034 - rust_begin_unwind
  10:     0x71a827f50563 - core::panicking::panic_fmt::hb546fe36be3a0f24
  11:     0x71a828efc287 - core::panicking::panic_bounds_check::h90b5d213a1bed1e4
  12:     0x71a82bb52baa - <rustc_mir_transform[9616e0e93931520b]::inline::Inliner>::try_inlining
  13:     0x71a82bb4fc89 - <rustc_mir_transform[9616e0e93931520b]::inline::Inliner>::process_blocks
  14:     0x71a82bb4fd09 - <rustc_mir_transform[9616e0e93931520b]::inline::Inliner>::process_blocks
  15:     0x71a82bb4f126 - <rustc_mir_transform[9616e0e93931520b]::inline::Inline as rustc_middle[2e745f839ecdcb12]::mir::MirPass>::run_pass
  16:     0x71a82b201cd1 - rustc_mir_transform[9616e0e93931520b]::pass_manager::run_passes_inner
  17:     0x71a82b7a1df2 - rustc_mir_transform[9616e0e93931520b]::optimized_mir
  18:     0x71a82c143ddb - rustc_query_impl[52474172086763ba]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[52474172086763ba]::query_impl::optimized_mir::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2e745f839ecdcb12]::query::erase::Erased<[u8; 8usize]>>
  19:     0x71a82b228434 - rustc_query_system[1f2263bc77e8d28d]::query::plumbing::try_execute_query::<rustc_query_impl[52474172086763ba]::DynamicConfig<rustc_query_system[1f2263bc77e8d28d]::query::caches::DefIdCache<rustc_middle[2e745f839ecdcb12]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[52474172086763ba]::plumbing::QueryCtxt, false>
  20:     0x71a82b2279df - rustc_query_impl[52474172086763ba]::query_impl::optimized_mir::get_query_non_incr::__rust_end_short_backtrace
  21:     0x71a827f13204 - <rustc_middle[2e745f839ecdcb12]::ty::context::TyCtxt>::instance_mir
  22:     0x71a82b9af306 - rustc_interface[922598e417aca69f]::passes::run_required_analyses
  23:     0x71a82bd3611e - rustc_interface[922598e417aca69f]::passes::analysis
  24:     0x71a82bd360f1 - rustc_query_impl[52474172086763ba]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[52474172086763ba]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[2e745f839ecdcb12]::query::erase::Erased<[u8; 1usize]>>
  25:     0x71a82c18efae - rustc_query_system[1f2263bc77e8d28d]::query::plumbing::try_execute_query::<rustc_query_impl[52474172086763ba]::DynamicConfig<rustc_query_system[1f2263bc77e8d28d]::query::caches::SingleCache<rustc_middle[2e745f839ecdcb12]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[52474172086763ba]::plumbing::QueryCtxt, false>
  26:     0x71a82c18ed0f - rustc_query_impl[52474172086763ba]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  27:     0x71a82bfced29 - rustc_interface[922598e417aca69f]::interface::run_compiler::<core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>, rustc_driver_impl[7bc6674bbf855457]::run_compiler::{closure#0}>::{closure#1}
  28:     0x71a82bfb6690 - std[c898dee7a900a719]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[922598e417aca69f]::util::run_in_thread_with_globals<rustc_interface[922598e417aca69f]::util::run_in_thread_pool_with_globals<rustc_interface[922598e417aca69f]::interface::run_compiler<core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>, rustc_driver_impl[7bc6674bbf855457]::run_compiler::{closure#0}>::{closure#1}, core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>>::{closure#0}, core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>>
  29:     0x71a82bfb6cfa - <<std[c898dee7a900a719]::thread::Builder>::spawn_unchecked_<rustc_interface[922598e417aca69f]::util::run_in_thread_with_globals<rustc_interface[922598e417aca69f]::util::run_in_thread_pool_with_globals<rustc_interface[922598e417aca69f]::interface::run_compiler<core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>, rustc_driver_impl[7bc6674bbf855457]::run_compiler::{closure#0}>::{closure#1}, core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>>::{closure#0}, core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[57139b9ad86af3c3]::result::Result<(), rustc_span[6e02c34e35948369]::ErrorGuaranteed>>::{closure#1} as core[57139b9ad86af3c3]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  30:     0x71a82bfb706b - std::sys::pal::unix::thread::Thread::new::thread_start::h2b4f313cc68cf720
  31:     0x71a82d72139d - <unknown>
  32:     0x71a82d7a649c - <unknown>
  33:                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 1.82.0-nightly (e5b3e68ab 2024-08-13) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z validate-mir -Z inline-mir=yes -Z dump-mir-dir=dir

query stack during panic:
#0 [optimized_mir] optimizing MIR for `field_array`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors; 4 warnings emitted

Some errors have detailed explanations: E0185, E0601.
For more information about an error, try `rustc --explain E0185`.

[matthiaskrgr]

#128612 :/

[matthiaskrgr]

auto-reduced (treereduce-rust):

//@compile-flags: -Zvalidate-mir -Cdebuginfo=2 -Copt-level=3
trait Meow {
    fn poll(&self) {}
}
impl<T> Meow for T {
    fn poll(&self, _ctx: &mut core::task::Context<'_>) {}
}
fn main() {
    ().poll();
}

original:

//@ revisions: e2021 e2024
//@[e2021] edition: 2021
//@[e2024] edition: 2024
//@[e2024] compile-flags: -Zunstable-options
//@ check-pass

#![deny(rust_2024_prelude_collisions)]
trait Meow {
    fn poll(&self) {}
}
impl<T> Meow for T {
    fn poll(&self, _ctx: &mut core::task::Context<'_>) {}
}
fn main() {
    // As the self type here is not `Pin<&mut _>`, the lint does not fire.
    ().poll();
}

Version information

rustc 1.84.0-nightly (4d215e242 2024-11-06)
binary: rustc
commit-hash: 4d215e2426d52ca8d1af166d5f6b5e172afbff67
commit-date: 2024-11-06
host: x86_64-unknown-linux-gnu
release: 1.84.0-nightly
LLVM version: 19.1.3

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zvalidate-mir -Cdebuginfo=2 -Copt-level=3

Program output

error[E0050]: method `poll` has 2 parameters but the declaration in trait `Meow::poll` has 1
 --> /tmp/icemaker_global_tempdir.KRNINZP9vLon/rustc_testrunner_tmpdir_reporting.cSioY6bOaXzL/mvce.rs:5:13
  |
2 |     fn poll(&self) {}
  |             ----- trait requires 1 parameter
...
5 |     fn poll(&self, _ctx: &mut core::task::Context<'_>) {}
  |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected 1 parameter, found 2

thread 'rustc' panicked at /rustc/4d215e2426d52ca8d1af166d5f6b5e172afbff67/compiler/rustc_middle/src/mir/tcx.rs:132:61:
index out of bounds: the len is 5 but the index is 5
stack backtrace:
   0:     0x75a3aa85231a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h2a62aef6790d7b15
   1:     0x75a3ab0043e6 - core::fmt::write::he06f597458bb9ff6
   2:     0x75a3ac3c0411 - std::io::Write::write_fmt::hd5df7cc41b85167f
   3:     0x75a3aa852172 - std::sys::backtrace::BacktraceLock::print::he947fb17670d9eba
   4:     0x75a3aa854676 - std::panicking::default_hook::{{closure}}::haee5081958228d5d
   5:     0x75a3aa8544c0 - std::panicking::default_hook::h9d9b924f5ca1a141
   6:     0x75a3a98d1e09 - std[fb7db6bd1f14c888]::panicking::update_hook::<alloc[42726f5bb67657ba]::boxed::Box<rustc_driver_impl[ececb8dd003d922]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x75a3aa854d88 - std::panicking::rust_panic_with_hook::hc489d1df4ff5f803
   8:     0x75a3aa854b5a - std::panicking::begin_panic_handler::{{closure}}::h26c53975a9f23f9b
   9:     0x75a3aa8527c9 - std::sys::backtrace::__rust_end_short_backtrace::h7f0b59d4cc0ea272
  10:     0x75a3aa85481c - rust_begin_unwind
  11:     0x75a3a72c9fe0 - core::panicking::panic_fmt::h16669a85d00adb4b
  12:     0x75a3a8fce7bb - core::panicking::panic_bounds_check::h56c3e34a596e7297
  13:     0x75a3a7ccbc8f - rustc_mir_transform[ae42b71eeaa5b7a0]::validate::validate_types
  14:     0x75a3ac012797 - <rustc_mir_transform[ae42b71eeaa5b7a0]::validate::Validator as rustc_mir_transform[ae42b71eeaa5b7a0]::pass_manager::MirPass>::run_pass
  15:     0x75a3a91c174f - rustc_mir_transform[ae42b71eeaa5b7a0]::pass_manager::validate_body
  16:     0x75a3ab006205 - rustc_mir_transform[ae42b71eeaa5b7a0]::pass_manager::run_passes_inner
  17:     0x75a3ab3a724a - rustc_mir_transform[ae42b71eeaa5b7a0]::optimized_mir
  18:     0x75a3ab3a5b1d - rustc_query_impl[3c80e39ee43abf73]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[3c80e39ee43abf73]::query_impl::optimized_mir::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3d70962cb5f21973]::query::erase::Erased<[u8; 8usize]>>
  19:     0x75a3ab02216a - rustc_query_system[ddfcc40078111d3b]::query::plumbing::try_execute_query::<rustc_query_impl[3c80e39ee43abf73]::DynamicConfig<rustc_query_system[ddfcc40078111d3b]::query::caches::DefIdCache<rustc_middle[3d70962cb5f21973]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[3c80e39ee43abf73]::plumbing::QueryCtxt, false>
  20:     0x75a3ab02171f - rustc_query_impl[3c80e39ee43abf73]::query_impl::optimized_mir::get_query_non_incr::__rust_end_short_backtrace
  21:     0x75a3a83abddf - <rustc_middle[3d70962cb5f21973]::ty::context::TyCtxt>::instance_mir
  22:     0x75a3ab836f24 - rustc_interface[bead3511298ef818]::passes::run_required_analyses
  23:     0x75a3abe06e5e - rustc_interface[bead3511298ef818]::passes::analysis
  24:     0x75a3abe06e2f - rustc_query_impl[3c80e39ee43abf73]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[3c80e39ee43abf73]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[3d70962cb5f21973]::query::erase::Erased<[u8; 1usize]>>
  25:     0x75a3abf7876e - rustc_query_system[ddfcc40078111d3b]::query::plumbing::try_execute_query::<rustc_query_impl[3c80e39ee43abf73]::DynamicConfig<rustc_query_system[ddfcc40078111d3b]::query::caches::SingleCache<rustc_middle[3d70962cb5f21973]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[3c80e39ee43abf73]::plumbing::QueryCtxt, false>
  26:     0x75a3abf7844e - rustc_query_impl[3c80e39ee43abf73]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  27:     0x75a3abe89cba - rustc_interface[bead3511298ef818]::interface::run_compiler::<core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>, rustc_driver_impl[ececb8dd003d922]::run_compiler::{closure#0}>::{closure#1}
  28:     0x75a3abf296d0 - std[fb7db6bd1f14c888]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[bead3511298ef818]::util::run_in_thread_with_globals<rustc_interface[bead3511298ef818]::util::run_in_thread_pool_with_globals<rustc_interface[bead3511298ef818]::interface::run_compiler<core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>, rustc_driver_impl[ececb8dd003d922]::run_compiler::{closure#0}>::{closure#1}, core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>>::{closure#0}, core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>>
  29:     0x75a3abf29aeb - <<std[fb7db6bd1f14c888]::thread::Builder>::spawn_unchecked_<rustc_interface[bead3511298ef818]::util::run_in_thread_with_globals<rustc_interface[bead3511298ef818]::util::run_in_thread_pool_with_globals<rustc_interface[bead3511298ef818]::interface::run_compiler<core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>, rustc_driver_impl[ececb8dd003d922]::run_compiler::{closure#0}>::{closure#1}, core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>>::{closure#0}, core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[8f4b167961bfb5e8]::result::Result<(), rustc_span[7b0df660ef271586]::ErrorGuaranteed>>::{closure#1} as core[8f4b167961bfb5e8]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  30:     0x75a3abf2a5b9 - std::sys::pal::unix::thread::Thread::new::thread_start::h820907c63bc21811
  31:     0x75a3ad7f539d - <unknown>
  32:     0x75a3ad87a49c - <unknown>
  33:                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 1.84.0-nightly (4d215e242 2024-11-06) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z validate-mir -C debuginfo=2 -C opt-level=3 -Z dump-mir-dir=dir

query stack during panic:
#0 [optimized_mir] optimizing MIR for `main`
#1 [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 E0050`.