ICE: error performing operation: fully_perform

[cushionbadak]

Code

(reduced)

trait Trait {
    type Type;
}

impl<T> Trait for T {
    type Type = ();
}

fn f(_: <&Copy as Trait>::Type) {}

fn main() {
    f(());
}

Original Code

//@ check-fail

trait Trait {
    type Type;
}

impl<T> Trait for T {
    type Type = ();
}

fn f<'a, 'b>(_: <&'a Copy as Trait>::Type)
where
    'a: 'a,
    'b: 'b,
{
}

fn g<'a, 'b>() {
    f::<'a, 'b>(());
    //~^ ERROR lifetime may not live long enough
}

fn main() {}

Meta

rustc --version --verbose:

rustc 1.79.0-nightly (f9b161492 2024-04-19)
binary: rustc
commit-hash: f9b16149208c8a8a349c32813312716f6603eb6f
commit-date: 2024-04-19
host: aarch64-apple-darwin
release: 1.79.0-nightly
LLVM version: 18.1.4

Command

rustc

Error output

warning: trait objects without an explicit `dyn` are deprecated
 --> r_crushed_497411.rs:9:11
  |
9 | fn f(_: <&Copy as Trait>::Type) {}
  |           ^^^^
  |
  = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
  = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
  = note: `#[warn(bare_trait_objects)]` on by default
help: if this is an object-safe trait, use `dyn`
  |
9 | fn f(_: <&dyn Copy as Trait>::Type) {}
  |           +++

warning: 1 warning emitted

note: no errors encountered even though delayed bugs were created

note: those delayed bugs will now be shown as internal compiler errors

Backtrace

error: internal compiler error: error performing operation: fully_perform
  --> r_crushed_497411.rs:12:5
   |
12 |     f(());
   |     ^^^^^
   |
note: delayed at /rustc/f9b16149208c8a8a349c32813312716f6603eb6f/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:85:25
         0: std::backtrace::Backtrace::create
         1: <rustc_errors::DiagCtxtInner>::emit_diagnostic
         2: <rustc_errors::DiagCtxt>::emit_diagnostic
         3: <rustc_errors::diagnostic::Diag>::emit_producing_error_guaranteed
         4: rustc_trait_selection::traits::query::type_op::custom::scrape_region_constraints::<rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate>, (), <rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate> as rustc_trait_selection::traits::query::type_op::TypeOp>::fully_perform::{closure#1}>
         5: <rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate> as rustc_trait_selection::traits::query::type_op::TypeOp>::fully_perform
         6: <rustc_borrowck::type_check::TypeChecker>::fully_perform_op::<(), rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate>>
         7: <rustc_borrowck::type_check::TypeChecker>::typeck_mir
         8: rustc_borrowck::type_check::type_check
         9: rustc_borrowck::nll::compute_regions
        10: rustc_borrowck::do_mir_borrowck
        11: rustc_borrowck::mir_borrowck
        12: rustc_query_impl::plumbing::__rust_begin_short_backtrace::<rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure#2}::{closure#0}, rustc_middle::query::erase::Erased<[u8; 8]>>
        13: <rustc_query_impl::query_impl::mir_borrowck::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId)>>::call_once
        14: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::VecCache<rustc_span::def_id::LocalDefId, rustc_middle::query::erase::Erased<[u8; 8]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
        15: rustc_query_impl::query_impl::mir_borrowck::get_query_non_incr::__rust_end_short_backtrace
        16: <rustc_middle::hir::map::Map>::par_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
        17: <rustc_data_structures::sync::parallel::ParallelGuard>::run::<(), rustc_data_structures::sync::parallel::enabled::par_for_each_in<&rustc_span::def_id::LocalDefId, &[rustc_span::def_id::LocalDefId], <rustc_middle::hir::map::Map>::par_body_owners<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}>::{closure#0}::{closure#1}::{closure#0}>
        18: <rustc_session::session::Session>::time::<(), rustc_interface::passes::run_required_analyses::{closure#1}>
        19: rustc_interface::passes::analysis
        20: 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; 1]>>
        21: <rustc_query_impl::query_impl::analysis::dynamic_query::{closure#2} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, ())>>::call_once
        22: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::DynamicConfig<rustc_query_system::query::caches::SingleCache<rustc_middle::query::erase::Erased<[u8; 1]>>, false, false, false>, rustc_query_impl::plumbing::QueryCtxt, false>
        23: rustc_query_impl::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
        24: <rustc_middle::ty::context::GlobalCtxt>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}::{closure#3}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
        25: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>>
        26: std::sys_common::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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
        27: <<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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#2} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
        28: std::sys::pal::unix::thread::Thread::new::thread_start
        29: __pthread_joiner_wake
  --> r_crushed_497411.rs:12:5
   |
12 |     f(());
   |     ^^^^^

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: please attach the file at `/Users/jisukbyun/workspace/placeholder/240420_rustexec/rustc-ice-2024-04-20T05_47_07-83822.txt` to your bug report

query stack during panic:
end of query stack

Note

• ICE-loc: compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs:85:25
  

  rust/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs

  Lines 82 to 86 in f9b1614

  	let value = infcx.commit_if_ok(|_| {
  	let ocx = ObligationCtxt::new(infcx);
  	let value = op(&ocx).map_err(|_| {
  	infcx.dcx().span_delayed_bug(span, format!("error performing operation: {name}"))
  	})?;

• Original ICE-triggering code is mutated from test-file implied-bounds-unnorm-associated-type-2.rs
  

  rust/tests/ui/fn/implied-bounds-unnorm-associated-type-2.rs

  Lines 11 to 16 in c8d19a9

  	fn f<'a, 'b>(_: <&'a &'b () as Trait>::Type)
  	where
  	'a: 'a,
  	'b: 'b,
  	{
  	}

[cushionbadak]

The ICE indeed appeared at rustc command (at nightly-2024-04-20 as reported),
but I cannot reproduce it with cargo-bisect-rustc.

❯ cargo bisect-rustc --version                                        
cargo-bisect-rustc-bisect-rustc 0.6.8

2024-01-01 ~ 2024-04-20 Log

❯ cargo bisect-rustc --start=2024-01-01 --end=2024-04-20 --preserve --regress=ice
checking the start range to find a passing nightly
installing nightly-2024-01-01
testing...
RESULT: nightly-2024-01-01, ===> No

checking the end range to verify it does not pass
installing nightly-2024-04-20
testing...
RESULT: nightly-2024-04-20, ===> No
uninstalling nightly-2024-04-20

ERROR: the end of the range (nightly-2024-04-20) does not reproduce the regression

Stack backtrace:
   0: __mh_execute_header
   1: __mh_execute_header
   2: __mh_execute_header
   3: __mh_execute_header
   4: __mh_execute_header
   5: __mh_execute_header

2024-01-01 ~ 2024-04-19 Log

❯ cargo bisect-rustc --start=2024-01-01 --end=2024-04-19 --preserve --regress=ice
checking the start range to find a passing nightly
installing nightly-2024-01-01
testing...
RESULT: nightly-2024-01-01, ===> No

checking the end range to verify it does not pass
installing nightly-2024-04-19
testing...
RESULT: nightly-2024-04-19, ===> No

ERROR: the end of the range (nightly-2024-04-19) does not reproduce the regression

Stack backtrace:
   0: __mh_execute_header
   1: __mh_execute_header
   2: __mh_execute_header
   3: __mh_execute_header
   4: __mh_execute_header
   5: __mh_execute_header

[matthiaskrgr]

This is probably a duplicate of #103899

[lqd]

Ah I see, it only ICEs on older editions. If you're using a new cargo project to bisect, it will be set to edition=2021 by cargo new.

With that, an ICE bisects to nightly-2022-08-10: broken MIR in DefId(0:9 ~ issue_124189[40d2]::main) (NoSolution): could not prove Binder(WellFormed(<&dyn std::marker::Copy as Trait>::Type), []).

Yeah it looks related to #103899, and both are in very close pieces of code -- although the repro there seems older, so maybe not an exact duplicate per se, but seemingly share some common WF-related cause. That one ICEs in liveness (one of the steps in MIR typeck, <rustc_borrowck::type_check::liveness::trace::LivenessContext>::compute_drop_data) while this one in MIR typeck directly (<rustc_borrowck::type_check::TypeChecker>::fully_perform_op::<(), rustc_middle::ty::ParamEnvAnd<rustc_middle::traits::query::type_op::ProvePredicate>>).