Unexpected type for constructor `Struct`

[Naserume]

Code

(reduced)

#![feature(box_patterns)]

use std::ops::{ Deref };

struct X(dyn Iterator<Item = &'a ()>);

impl Deref for X {
    type Target = isize;

    fn deref(&self) -> &isize {
        let &X(box ref x) = self;
        x
    }
}

fn main() { }

(original)

//@ run-pass
#![feature(box_patterns)]

use std::ops::{Deref, DerefMut};

struct X(Iterator<Item = &'a ()>);

static mut DESTRUCTOR_RAN: bool = false;

impl Drop for X {
    fn drop(&mut self) {
        unsafe {
            assert!(!DESTRUCTOR_RAN);
            DESTRUCTOR_RAN = true;
        }
    }
}

impl Deref for X {
    type Target = isize;

    fn deref(&self) -> &isize {
        let &X(box ref x) = self;
        x
    }
}

impl DerefMut for X {
    fn deref_mut(&mut self) -> &mut isize {
        let &mut X(box ref mut x) = self
        x
    }
}

fn main() {
    {
        let mut test = X(Box::new(5));
        {
            let mut change = || { *test = 10 };
            change();
        }
        assert_eq!(*test, 10);
    }
    assert!(unsafe { DESTRUCTOR_RAN });
}

Meta

rustc --version --verbose:

rustc 1.79.0-nightly (0d8b3346a 2024-04-14)
binary: rustc
commit-hash: 0d8b3346a3992ab11ea35ff0fb95a6864b91f797
commit-date: 2024-04-14
host: x86_64-unknown-linux-gnu
release: 1.79.0-nightly
LLVM version: 18.1.3

Error output

error[E0261]: use of undeclared lifetime name `'a`
 --> ./42014B0E5BEE51773962BDC66C19A687BF2BCA268F20494CFBF764F616612328.rs:5:31
  |
5 | struct X(dyn Iterator<Item = &'a ()>);
  |                               ^^ undeclared lifetime
  |
  = note: for more information on higher-ranked polymorphism, visit https://doc.rust-lang.org/nomicon/hrtb.html
help: consider making the bound lifetime-generic with a new `'a` lifetime
  |
5 | struct X(dyn for<'a> Iterator<Item = &'a ()>);
  |              +++++++
help: consider introducing lifetime `'a` here
  |
5 | struct X<'a>(dyn Iterator<Item = &'a ()>);
  |         ++++

Backtrace

error: internal compiler error: compiler/rustc_pattern_analysis/src/rustc.rs:235:22: Unexpected type for constructor `Struct`: dyn [Binder(Trait(std::iter::Iterator), []), Binder(Projection(ExistentialProjection { def_id: DefId(2:8346 ~ core[5d06]::iter::traits::iterator::Iterator::Item), args: [], term: Term::Ty(&'{erased} ()) }), [])] + '{erased}

thread 'rustc' panicked at compiler/rustc_pattern_analysis/src/rustc.rs:235:22:
Box<dyn Any>
stack backtrace:
   0:        0x10d2abc33 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h64c2afb309c31778
   1:        0x10d2f76eb - core::fmt::write::hc23fab116e688c5a
   2:        0x10d2a1d7e - std::io::Write::write_fmt::hc554712574aee1b1
   3:        0x10d2aba21 - std::sys_common::backtrace::print::h8d045d1d6d8eda73
   4:        0x10d2ae719 - std::panicking::default_hook::{{closure}}::h65ac21535f58ee0a
   5:        0x10d2ae460 - std::panicking::default_hook::h24915649deb9e4fc
   6:        0x115f1d56c - std[28e242a172f62cc5]::panicking::update_hook::<alloc[d18bf54b8bbef4a6]::boxed::Box<rustc_driver_impl[a82bc910fff4ad06]::install_ice_hook::{closure#0}>>::{closure#0}
   7:        0x10d2af23c - std::panicking::rust_panic_with_hook::hfb2063d444201996
   8:        0x115f8418a - std[28e242a172f62cc5]::panicking::begin_panic::<rustc_errors[748ffab8893d222]::ExplicitBug>::{closure#0}
   9:        0x115f7c6b9 - std[28e242a172f62cc5]::sys_common::backtrace::__rust_end_short_backtrace::<std[28e242a172f62cc5]::panicking::begin_panic<rustc_errors[748ffab8893d222]::ExplicitBug>::{closure#0}, !>
  10:        0x11a6b3f19 - std[28e242a172f62cc5]::panicking::begin_panic::<rustc_errors[748ffab8893d222]::ExplicitBug>
  11:        0x115f978d6 - <rustc_errors[748ffab8893d222]::diagnostic::BugAbort as rustc_errors[748ffab8893d222]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:        0x116a7275e - rustc_middle[e34a00149b4583d7]::util::bug::opt_span_bug_fmt::<rustc_span[708ae0672d259dca]::span_encoding::Span>::{closure#0}
  13:        0x116a23417 - rustc_middle[e34a00149b4583d7]::ty::context::tls::with_opt::<rustc_middle[e34a00149b4583d7]::util::bug::opt_span_bug_fmt<rustc_span[708ae0672d259dca]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:        0x116a22f25 - rustc_middle[e34a00149b4583d7]::ty::context::tls::with_context_opt::<rustc_middle[e34a00149b4583d7]::ty::context::tls::with_opt<rustc_middle[e34a00149b4583d7]::util::bug::opt_span_bug_fmt<rustc_span[708ae0672d259dca]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:        0x11a772a0b - rustc_middle[e34a00149b4583d7]::util::bug::bug_fmt
  16:        0x117087998 - <rustc_pattern_analysis[44ef45dd33bf8897]::rustc::RustcPatCtxt as rustc_pattern_analysis[44ef45dd33bf8897]::PatCx>::ctor_sub_tys
  17:        0x1170912d9 - rustc_pattern_analysis[44ef45dd33bf8897]::usefulness::compute_exhaustiveness_and_usefulness::<rustc_pattern_analysis[44ef45dd33bf8897]::rustc::RustcPatCtxt>
  18:        0x117091c87 - rustc_pattern_analysis[44ef45dd33bf8897]::usefulness::compute_exhaustiveness_and_usefulness::<rustc_pattern_analysis[44ef45dd33bf8897]::rustc::RustcPatCtxt>
  19:        0x117091c87 - rustc_pattern_analysis[44ef45dd33bf8897]::usefulness::compute_exhaustiveness_and_usefulness::<rustc_pattern_analysis[44ef45dd33bf8897]::rustc::RustcPatCtxt>
  20:        0x11708c477 - rustc_pattern_analysis[44ef45dd33bf8897]::analyze_match
  21:        0x116b6e783 - <rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::MatchVisitor>::analyze_patterns
  22:        0x116ba23c5 - <rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::MatchVisitor>::check_binding_is_irrefutable
  23:        0x116ba2275 - <rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::MatchVisitor>::check_let
  24:        0x116ae4bc3 - rustc_middle[e34a00149b4583d7]::thir::visit::walk_block::<rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::MatchVisitor>
  25:        0x116ba1a9d - <rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::MatchVisitor as rustc_middle[e34a00149b4583d7]::thir::visit::Visitor>::visit_expr
  26:        0x116ba151c - <rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::MatchVisitor as rustc_middle[e34a00149b4583d7]::thir::visit::Visitor>::visit_expr
  27:        0x116b6da69 - rustc_mir_build[f8655712974bcade]::thir::pattern::check_match::check_match
  28:        0x11736aeba - rustc_query_impl[1cf588037da06ac4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1cf588037da06ac4]::query_impl::check_match::dynamic_query::{closure#2}::{closure#0}, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 1usize]>>
  29:        0x1171f1afc - rustc_query_system[98688be416762701]::query::plumbing::try_execute_query::<rustc_query_impl[1cf588037da06ac4]::DynamicConfig<rustc_query_system[98688be416762701]::query::caches::VecCache<rustc_span[708ae0672d259dca]::def_id::LocalDefId, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1cf588037da06ac4]::plumbing::QueryCtxt, false>
  30:        0x11739da90 - rustc_query_impl[1cf588037da06ac4]::query_impl::check_match::get_query_non_incr::__rust_end_short_backtrace
  31:        0x116b227d2 - rustc_mir_build[f8655712974bcade]::build::mir_build
  32:        0x116dbd63f - rustc_mir_transform[f6c980be58df0e21]::mir_built
  33:        0x11736fa5a - rustc_query_impl[1cf588037da06ac4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1cf588037da06ac4]::query_impl::mir_built::dynamic_query::{closure#2}::{closure#0}, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 8usize]>>
  34:        0x1171fa517 - rustc_query_system[98688be416762701]::query::plumbing::try_execute_query::<rustc_query_impl[1cf588037da06ac4]::DynamicConfig<rustc_query_system[98688be416762701]::query::caches::VecCache<rustc_span[708ae0672d259dca]::def_id::LocalDefId, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1cf588037da06ac4]::plumbing::QueryCtxt, false>
  35:        0x11738004b - rustc_query_impl[1cf588037da06ac4]::query_impl::mir_built::get_query_non_incr::__rust_end_short_backtrace
  36:        0x116b66eff - rustc_mir_build[f8655712974bcade]::check_unsafety::check_unsafety
  37:        0x11736b53a - rustc_query_impl[1cf588037da06ac4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1cf588037da06ac4]::query_impl::check_unsafety::dynamic_query::{closure#2}::{closure#0}, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 0usize]>>
  38:        0x1171eaacb - rustc_query_system[98688be416762701]::query::plumbing::try_execute_query::<rustc_query_impl[1cf588037da06ac4]::DynamicConfig<rustc_query_system[98688be416762701]::query::caches::VecCache<rustc_span[708ae0672d259dca]::def_id::LocalDefId, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[1cf588037da06ac4]::plumbing::QueryCtxt, false>
  39:        0x11738e830 - rustc_query_impl[1cf588037da06ac4]::query_impl::check_unsafety::get_query_non_incr::__rust_end_short_backtrace
  40:        0x116684db2 - <rustc_middle[e34a00149b4583d7]::hir::map::Map>::par_body_owners::<rustc_interface[2cf32266391f9a3e]::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
  41:        0x1166d728c - rustc_interface[2cf32266391f9a3e]::passes::run_required_analyses
  42:        0x1166d9770 - rustc_interface[2cf32266391f9a3e]::passes::analysis
  43:        0x11736f74a - rustc_query_impl[1cf588037da06ac4]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1cf588037da06ac4]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 1usize]>>
  44:        0x11715141e - rustc_query_system[98688be416762701]::query::plumbing::try_execute_query::<rustc_query_impl[1cf588037da06ac4]::DynamicConfig<rustc_query_system[98688be416762701]::query::caches::SingleCache<rustc_middle[e34a00149b4583d7]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1cf588037da06ac4]::plumbing::QueryCtxt, false>
  45:        0x117379b17 - rustc_query_impl[1cf588037da06ac4]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  46:        0x115eca3a7 - <rustc_interface[2cf32266391f9a3e]::queries::QueryResult<&rustc_middle[e34a00149b4583d7]::ty::context::GlobalCtxt>>::enter::<core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>, rustc_driver_impl[a82bc910fff4ad06]::run_compiler::{closure#0}::{closure#1}::{closure#3}>
  47:        0x115f1bbdf - rustc_interface[2cf32266391f9a3e]::interface::run_compiler::<core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>, rustc_driver_impl[a82bc910fff4ad06]::run_compiler::{closure#0}>::{closure#0}
  48:        0x115f0bdad - std[28e242a172f62cc5]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[2cf32266391f9a3e]::util::run_in_thread_with_globals<rustc_interface[2cf32266391f9a3e]::util::run_in_thread_pool_with_globals<rustc_interface[2cf32266391f9a3e]::interface::run_compiler<core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>, rustc_driver_impl[a82bc910fff4ad06]::run_compiler::{closure#0}>::{closure#0}, core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>>::{closure#0}, core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>>
  49:        0x115f254d6 - <<std[28e242a172f62cc5]::thread::Builder>::spawn_unchecked_<rustc_interface[2cf32266391f9a3e]::util::run_in_thread_with_globals<rustc_interface[2cf32266391f9a3e]::util::run_in_thread_pool_with_globals<rustc_interface[2cf32266391f9a3e]::interface::run_compiler<core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>, rustc_driver_impl[a82bc910fff4ad06]::run_compiler::{closure#0}>::{closure#0}, core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>>::{closure#0}, core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5d06e84208279116]::result::Result<(), rustc_span[708ae0672d259dca]::ErrorGuaranteed>>::{closure#2} as core[5d06e84208279116]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  50:        0x10d2b895b - std::sys::pal::unix::thread::Thread::new::thread_start::h46ddcf9131ad2508
  51:     0x7ff818270202 - __pthread_start

query stack during panic:
#0 [check_match] match-checking `<impl at ./42014B0E5BEE51773962BDC66C19A687BF2BCA268F20494CFBF764F616612328.rs:7:1: 7:17>::deref`
#1 [mir_built] building MIR for `<impl at ./42014B0E5BEE51773962BDC66C19A687BF2BCA268F20494CFBF764F616612328.rs:7:1: 7:17>::deref`
#2 [check_unsafety] unsafety-checking `<impl at ./42014B0E5BEE51773962BDC66C19A687BF2BCA268F20494CFBF764F616612328.rs:7:1: 7:17>::deref`
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0261`.

### Tasks

[cushionbadak]

searched nightlies: from nightly-2024-01-01 to nightly-2024-04-04
regressed nightly: nightly-2024-03-22
searched commit range: 1388d7a...0ad927c
regressed commit: 6a6cd65

bisected with cargo-bisect-rustc v0.6.8

Host triple: x86_64-apple-darwin
Reproduce with:

cargo bisect-rustc --start=2024-01-01 --end=2024-04-04 --preserve --regress=ice

[matthiaskrgr]

might be #122749

[saethlin]

This still ICEs, so I don't think so.

[matthiaskrgr]

@saethlin huh, what do you mean?

[matthiaskrgr]

#122749 is a PR, not a different issue 😅

[saethlin]

Oh you meant the cause not that this is a duplicate 🤦

[matthiaskrgr]

yeh :D