ICE: `expected bits of isize, got Ty(3_isize,)`

[cushionbadak]

Code

(hand-reduced)

trait Trait<T> {
    type Assoc;
}

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

impl Trait<u8> for Vec<u8> {}

const BAR: <Vec<u8> as Trait<u8>>::Assoc = 3;

pub fn main() {
    let x: isize = 3;
    let _ = match x {
        BAR => 2,
        _ => 3,
    };
}

(original)

use inner_private_module::*;

mod inner_private_module {
    pub struct Unnameable1;
    pub struct Unnameable2;
    #[derive(Clone, Copy)]
    pub struct Unnameable3;
    pub struct Unnameable4;
    pub struct Unnameable5;
    pub struct Unnameable6;
    pub struct Unnameable7;
    #[derive(Default)]
    pub struct Unnameable8;
    pub enum UnnameableEnum {
        NameableVariant
    }
    pub trait UnnameableTrait {
        type Alias: Default;
    }

    impl Unnameable1 {
        pub fn method_of_unnameable_type1(&self) -> &'static str {
            "Hello1"
        }
    }
    impl Unnameable2 {
        pub fn method_of_unnameable_type2(&self) -> &'static str {
            "Hello2"
        }
    }
    impl Unnameable3 {
        pub fn method_of_unnameable_type3(&self) -> &'static str {
            "Hello3"
        }
    }
    impl Unnameable4 {
        pub fn method_of_unnameable_type4(&self) -> &'static str {
            "Hello4"
        }
    }
    impl Unnameable5 {
        pub fn method_of_unnameable_type5(&self) -> &'static str {
            "Hello5"
        }
    }
    impl Unnameable6 {
        pub fn method_of_unnameable_type6(&self) -> &'static str {
            "Hello6"
        }
    }
    impl Unnameable7 {
        pub fn method_of_unnameable_type7(&self) -> &'static str {
            "Hello7"
        }
    }
    impl Unnameable8 {
        pub fn method_of_unnameable_type8(&self) -> &'static str {
            "Hello8"
        }
    }
    impl UnnameableEnum {
        pub fn method_of_unnameable_enum(&self) -> &'static str {
            "HelloEnum"
        }
    }
}

pub fn function_returning_unnameable_type() -> Unnameable1 {
    Unnameable1
}

pub const CONSTANT_OF_UNNAMEABLE_TYPE: Unnameable2 =
                                            Unnameable2;

pub fn function_accepting_unnameable_type(_: Option<Unnameable3>) {}

pub type AliasOfUnnameableType = Unnameable4;

impl Unnameable1 {
    pub fn inherent_method_returning_unnameable_type(&self) -> Unnameable5 {
        Unnameable5
    }
}

pub trait Tr {
    fn trait_method_returning_unnameable_type(&self) -> Unnameable6 {
        Unnameable6
    }
}
impl Tr for Unnameable1 {}

pub use inner_private_module::UnnameableEnum::NameableVariant;

pub struct Struct {
    pub field_of_unnameable_type: Unnameable7
}

pub static STATIC: Struct = Struct { field_of_unnameable_type: Unnameable7 } ;

impl UnnameableTrait for AliasOfUnnameableType {
    type Alias = Unnameable8;
}

pub fn generic_function<T: UnnameableTrait>() -> T::Alias {
    Default::default()
}


// Formerly this ICEd with the following message:
// Tried to project an inherited associated type during coherence checking,
// which is currently not supported.
//
// No we expect to run into a more user-friendly cycle error instead.
#![feature(specialization)]
//~^ WARN the feature `specialization` is incomplete

trait Trait<T> { type Assoc; }
//~^ ERROR E0391

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

impl Trait<u8> for Vec<u8> {}

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

impl Trait<<Vec<u8> as T::Alias<u8>>::Assoc> for String {}

fn main() {}


//@ run-pass

const FOO: isize = 10;
const BAR: <Vec<u8> as Trait<u8>>::Assoc = 3;
const ZST: &() = unsafe { std::mem::transmute(1usize) };
const ZST_ARR: &[u8; 0] = unsafe { std::mem::transmute(1usize) };

const fn foo() -> isize { 4 }
const BOO: isize = foo();

pub fn main() {
    let x: isize = 3;
    let y = match x {
        FOO => 1,
        BAR => 2,
        BOO => 4,
        _ => 3
    };
    assert_eq!(y, 2);
    let z = match &() {
        ZST => 9,
    };
    assert_eq!(z, 9);
    let z = match b"" {
        ZST_ARR => 10,
    };
    assert_eq!(z, 10);
}

Meta

rustc --version --verbose:

rustc 1.80.0-nightly (6f3df08aa 2024-05-30)
binary: rustc
commit-hash: 6f3df08aadf71e8d4bf7e49f5dc10dfa6f254cb4
commit-date: 2024-05-30
host: x86_64-apple-darwin
release: 1.80.0-nightly
LLVM version: 18.1.6

Error output

Command: rustc

error[E0119]: conflicting implementations of trait `Trait<u8>` for type `Vec<u8>`
 --> r_consts_17666C.rs:9:1
  |
5 | impl<T> Trait<T> for Vec<T> {
  | --------------------------- first implementation here
...
9 | impl Trait<u8> for Vec<u8> {}
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Vec<u8>`

Backtrace

error: internal compiler error: /rustc/6f3df08aadf71e8d4bf7e49f5dc10dfa6f254cb4/compiler/rustc_middle/src/mir/consts.rs:374:32: expected bits of isize, got Ty(
                                    3_isize,
                                )

thread 'rustc' panicked at /rustc/6f3df08aadf71e8d4bf7e49f5dc10dfa6f254cb4/compiler/rustc_middle/src/mir/consts.rs:374:32:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   3: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   4: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   5: rustc_middle::util::bug::bug_fmt
   6: <rustc_middle::mir::consts::Const>::eval_bits::{closure#0}
   7: <rustc_mir_build::build::Builder>::test_candidates_with_or
   8: <rustc_mir_build::build::Builder>::match_candidates::{closure#0}
   9: <rustc_mir_build::build::Builder>::match_candidates
  10: <rustc_mir_build::build::Builder>::lower_match_tree
  11: <rustc_mir_build::build::Builder>::expr_into_dest
  12: <rustc_mir_build::build::Builder>::as_temp_inner
  13: <rustc_mir_build::build::Builder>::expr_as_place
  14: <rustc_mir_build::build::Builder>::expr_as_place
  15: <rustc_mir_build::build::Builder>::lower_scrutinee
  16: <rustc_mir_build::build::Builder>::ast_block_stmts
  17: <rustc_mir_build::build::Builder>::expr_into_dest
  18: <rustc_mir_build::build::Builder>::expr_into_dest::{closure#0}
  19: <rustc_mir_build::build::Builder>::expr_into_dest
  20: rustc_mir_build::build::construct_fn
  21: rustc_mir_build::build::mir_build
  22: rustc_mir_transform::mir_built
      [... omitted 1 frame ...]
  23: rustc_mir_build::check_unsafety::check_unsafety
      [... omitted 1 frame ...]
  24: <rustc_middle::hir::map::Map>::par_body_owners::<rustc_interface::passes::run_required_analyses::{closure#1}::{closure#0}>::{closure#0}
  25: rustc_interface::passes::run_required_analyses
  26: rustc_interface::passes::analysis
      [... omitted 1 frame ...]
  27: <rustc_interface::queries::QueryResult<&rustc_middle::ty::context::GlobalCtxt>>::enter::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}::{closure#1}::{closure#3}>
  28: rustc_interface::interface::run_compiler::<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 `/Volumes/T7/workspace/240530_100chaos_tree_combine_typ/icefiles/rustc-ice-2024-05-31T07_39_02-97364.txt` to your bug report

query stack during panic:
#0 [mir_built] building MIR for `main`
#1 [check_unsafety] unsafety-checking `main`
#2 [analysis] running analysis passes on this crate
end of query stack
error[E0282]: type annotations needed
  --> r_consts_17666C.rs:11:12
   |
11 | const BAR: <Vec<u8> as Trait<u8>>::Assoc = 3;
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0119, E0282.
For more information about an error, try `rustc --explain E0119`.

Note

• ICE location: rustc_middle/src/mir/consts.rs L374
  

  rust/compiler/rustc_middle/src/mir/consts.rs

  Lines 370 to 375 in 6f3df08

  	/// Panics if the value cannot be evaluated or doesn't contain a valid integer of the given type.
  	#[inline]
  	pub fn eval_bits(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> u128 {
  	self.try_eval_bits(tcx, param_env)
  	.unwrap_or_else(|| bug!("expected bits of {:#?}, got {:#?}", self.ty(), self))
  	}

• A solved ICE issue ICE: expected bits of u8, got Ty(10_u32,) #123092 has identical ICE location.

[cushionbadak]

searched nightlies: from nightly-2023-01-01 to nightly-2024-05-30
regressed nightly: nightly-2024-02-15
searched commit range: a84bb95...ee9c7c9
regressed commit: ee9c7c9

bisected with cargo-bisect-rustc v0.6.8

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo bisect-rustc --start=2023-01-01 --end=2024-05-30 --regress=ice --script=rustc --preserve -- 125799.rs