ICE calling method on `auto` trait

[jruderman]

Found with a modified fuzz-rustc

Code

#![feature(auto_traits)]

auto trait Foo {
    fn g(&self);
}

trait Bar {
    fn f(&self) {
        self.g();
    }
}

fn main() {}

Error output

error[E0380]: auto traits cannot have associated items

thread 'rustc' panicked at 'internal error: entered unreachable code', compiler/rustc_hir_typeck/src/method/suggest.rs:691

Full output including backtrace

error[E0380]: auto traits cannot have associated items
 --> f2db.rs:4:8
  |
3 | auto trait Foo {
  |            --- auto trait cannot have associated items
4 |     fn g(&self);
  |     ---^-------- help: remove these associated items

thread 'rustc' panicked at 'internal error: entered unreachable code', compiler/rustc_hir_typeck/src/method/suggest.rs:691:40
stack backtrace:
   0:        0x1060ad731 - ___fixunssfsi
   1:        0x106138b08 - core::fmt::write::hed31846cddb4e13c
   2:        0x106084b28 - std::io::Write::write_fmt::hf6e0f2914bebea98
   3:        0x1060ad522 - std::sys_common::backtrace::print::h905a3d11750ea1e9
   4:        0x1060bdd35 - std::panicking::default_hook::{{closure}}::he83c590da184b003
   5:        0x1060bdb1e - std::panicking::default_hook::hd8c8acc029e0c8cd
   6:        0x112ca3ae8 - rustc_driver[75b940a0d44b1efd]::DEFAULT_HOOK::{closure#0}::{closure#0}
   7:        0x1060be526 - std::panicking::rust_panic_with_hook::h0cf82b3605a8081f
   8:        0x1060aca52 - std::panicking::begin_panic_handler::{{closure}}::h7d24d0bcbcd0c8c3
   9:        0x1060ac9c8 - std::sys_common::backtrace::__rust_end_short_backtrace::h584365ffa1be1317
  10:        0x1060bde08 - _rust_begin_unwind
  11:        0x10615d483 - core::panicking::panic_fmt::h7ec57a9a63e6db71
  12:        0x10615d557 - core::panicking::panic::h604eaa4391462ac9
  13:        0x115694776 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::report_method_error
  14:        0x1156bcb23 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_expr_kind
  15:        0x115663617 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  16:        0x1156babd4 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_expr_with_expectation
  17:        0x11567ea8c - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_stmt
  18:        0x1155b6a96 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::with_breakable_ctxt::<<rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_block_with_expected::{closure#0}, ()>
  19:        0x11567ed4d - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_block_with_expected
  20:        0x1156bbf9f - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_expr_kind
  21:        0x115663617 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  22:        0x1156babd4 - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_expr_with_expectation
  23:        0x1156652df - <rustc_hir_typeck[b7aa618f0b708977]::fn_ctxt::FnCtxt>::check_return_expr
  24:        0x1156425c2 - rustc_hir_typeck[b7aa618f0b708977]::check::check_fn
  25:        0x115567200 - <rustc_hir_typeck[b7aa618f0b708977]::inherited::InheritedBuilder>::enter::<rustc_hir_typeck[b7aa618f0b708977]::typeck_with_fallback<rustc_hir_typeck[b7aa618f0b708977]::typeck::{closure#0}>::{closure#0}::{closure#1}, &rustc_middle[2716ddfd79b0a8a6]::ty::context::TypeckResults>
  26:        0x11561aef5 - rustc_hir_typeck[b7aa618f0b708977]::typeck_with_fallback::<rustc_hir_typeck[b7aa618f0b708977]::typeck::{closure#0}>
  27:        0x11564c46f - rustc_hir_typeck[b7aa618f0b708977]::typeck
  28:        0x116d59d6b - rustc_query_system[47b5c57ee62d79cf]::query::plumbing::try_execute_query::<rustc_query_impl[6353a2785d754f42]::plumbing::QueryCtxt, rustc_query_system[47b5c57ee62d79cf]::query::caches::VecCache<rustc_span[c887fc7c2a0a81b]::def_id::LocalDefId, &rustc_middle[2716ddfd79b0a8a6]::ty::context::TypeckResults>>
  29:        0x116e5862e - rustc_query_system[47b5c57ee62d79cf]::query::plumbing::get_query::<rustc_query_impl[6353a2785d754f42]::queries::typeck, rustc_query_impl[6353a2785d754f42]::plumbing::QueryCtxt>
  30:        0x116ade03f - <rustc_query_impl[6353a2785d754f42]::Queries as rustc_middle[2716ddfd79b0a8a6]::ty::query::QueryEngine>::typeck
  31:        0x115626b13 - <core[95bb6d661b676f4d]::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures[49afb3d772895c69]::sync::par_for_each_in<&[rustc_span[c887fc7c2a0a81b]::def_id::LocalDefId], <rustc_middle[2716ddfd79b0a8a6]::hir::map::Map>::par_body_owners<rustc_hir_typeck[b7aa618f0b708977]::typeck_item_bodies::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}> as core[95bb6d661b676f4d]::ops::function::FnOnce<()>>::call_once
  32:        0x11564aad0 - std[150eb488e385df0f]::panicking::try::<(), core[95bb6d661b676f4d]::panic::unwind_safe::AssertUnwindSafe<rustc_data_structures[49afb3d772895c69]::sync::par_for_each_in<&[rustc_span[c887fc7c2a0a81b]::def_id::LocalDefId], <rustc_middle[2716ddfd79b0a8a6]::hir::map::Map>::par_body_owners<rustc_hir_typeck[b7aa618f0b708977]::typeck_item_bodies::{closure#0}>::{closure#0}>::{closure#0}::{closure#0}>>
  33:        0x115722153 - rustc_data_structures[49afb3d772895c69]::sync::par_for_each_in::<&[rustc_span[c887fc7c2a0a81b]::def_id::LocalDefId], <rustc_middle[2716ddfd79b0a8a6]::hir::map::Map>::par_body_owners<rustc_hir_typeck[b7aa618f0b708977]::typeck_item_bodies::{closure#0}>::{closure#0}>
  34:        0x11564c22a - rustc_hir_typeck[b7aa618f0b708977]::typeck_item_bodies
  35:        0x116d38427 - rustc_query_system[47b5c57ee62d79cf]::query::plumbing::try_execute_query::<rustc_query_impl[6353a2785d754f42]::plumbing::QueryCtxt, rustc_query_system[47b5c57ee62d79cf]::query::caches::DefaultCache<(), ()>>
  36:        0x116e1145d - rustc_query_system[47b5c57ee62d79cf]::query::plumbing::get_query::<rustc_query_impl[6353a2785d754f42]::queries::typeck_item_bodies, rustc_query_impl[6353a2785d754f42]::plumbing::QueryCtxt>
  37:        0x116add9d7 - <rustc_query_impl[6353a2785d754f42]::Queries as rustc_middle[2716ddfd79b0a8a6]::ty::query::QueryEngine>::typeck_item_bodies
  38:        0x1158c9245 - <rustc_session[9e89c47467305ea5]::session::Session>::time::<(), rustc_hir_analysis[39115411e53478da]::check_crate::{closure#7}>
  39:        0x1158a97ee - rustc_hir_analysis[39115411e53478da]::check_crate
  40:        0x112e423ea - rustc_interface[3c94b850180ed4ea]::passes::analysis
  41:        0x116d28658 - rustc_query_system[47b5c57ee62d79cf]::query::plumbing::try_execute_query::<rustc_query_impl[6353a2785d754f42]::plumbing::QueryCtxt, rustc_query_system[47b5c57ee62d79cf]::query::caches::DefaultCache<(), core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>>
  42:        0x116e589dd - rustc_query_system[47b5c57ee62d79cf]::query::plumbing::get_query::<rustc_query_impl[6353a2785d754f42]::queries::analysis, rustc_query_impl[6353a2785d754f42]::plumbing::QueryCtxt>
  43:        0x116aba127 - <rustc_query_impl[6353a2785d754f42]::Queries as rustc_middle[2716ddfd79b0a8a6]::ty::query::QueryEngine>::analysis
  44:        0x112cb2ff4 - <rustc_interface[3c94b850180ed4ea]::passes::QueryContext>::enter::<rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}::{closure#2}::{closure#2}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>
  45:        0x112c93b3d - <rustc_interface[3c94b850180ed4ea]::interface::Compiler>::enter::<rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}::{closure#2}, core[95bb6d661b676f4d]::result::Result<core[95bb6d661b676f4d]::option::Option<rustc_interface[3c94b850180ed4ea]::queries::Linker>, rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>
  46:        0x112c91241 - rustc_span[c887fc7c2a0a81b]::with_source_map::<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, rustc_interface[3c94b850180ed4ea]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  47:        0x112cdef0a - <scoped_tls[c451c38e2ed76225]::ScopedKey<rustc_span[c887fc7c2a0a81b]::SessionGlobals>>::set::<rustc_interface[3c94b850180ed4ea]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>
  48:        0x112cae0a0 - std[150eb488e385df0f]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[3c94b850180ed4ea]::util::run_in_thread_pool_with_globals<rustc_interface[3c94b850180ed4ea]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>
  49:        0x112cd1810 - std[150eb488e385df0f]::panicking::try::<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, core[95bb6d661b676f4d]::panic::unwind_safe::AssertUnwindSafe<<std[150eb488e385df0f]::thread::Builder>::spawn_unchecked_<rustc_interface[3c94b850180ed4ea]::util::run_in_thread_pool_with_globals<rustc_interface[3c94b850180ed4ea]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>::{closure#1}::{closure#0}>>
  50:        0x112cce071 - <<std[150eb488e385df0f]::thread::Builder>::spawn_unchecked_<rustc_interface[3c94b850180ed4ea]::util::run_in_thread_pool_with_globals<rustc_interface[3c94b850180ed4ea]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>, rustc_driver[75b940a0d44b1efd]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[dcd2348bee1b0385]::ErrorGuaranteed>>::{closure#1} as core[95bb6d661b676f4d]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  51:        0x10608107b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h363a7f79aa0064c8
  52:        0x1060b889f - std::sys::unix::thread::Thread::new::thread_start::hee5a1e4745806fcc
  53:     0x7ff80c3874e1 - __pthread_start

error: internal compiler error: unexpected panic

note: 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: rustc 1.68.0-dev running on x86_64-apple-darwin

query stack during panic:
#0 [typeck] type-checking `Bar::f`
#1 [typeck_item_bodies] type-checking all item bodies
#2 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error

For more information about this error, try `rustc --explain E0380`.

Regression

Regression in nightly-2022-11-05, somewhere in rollup 0950848, likely #103937 (CC @BoxyUwU)

Version

2022-12-14 fbf8b93

@rustbot label +F-auto_traits

[chenyukang]

@rustbot claim

[chenyukang]

Fixed the ICE, the error message now is:

cat@LAPTOP-V6U0QKD4:~/code/rust$ j dev         src/test/ui/methods/issues/issue-105732.rs
rustc +dev src/test/ui/methods/issues/issue-105732.rs
error[E0380]: auto traits cannot have associated items
 --> src/test/ui/methods/issues/issue-105732.rs:4:8
  |
3 | auto trait Foo {
  |            --- auto trait cannot have associated items
4 |     fn g(&self); //~ ERROR auto traits cannot have associated items
  |     ---^-------- help: remove these associated items

error[E0599]: the method `g` exists for reference `&Self`, but its trait bounds were not satisfied
 --> src/test/ui/methods/issues/issue-105732.rs:9:14
  |
9 |         self.g();
  |              ^
  |
  = note: the following trait bounds were not satisfied:
          `Self: Foo`
          which is required by `&Self: Foo`
          `&Self: Foo`
  = help: items from traits can only be used if the type parameter is bounded by the trait
help: the following trait defines an item `g`, perhaps you need to add a supertrait for it:
  |
7 | trait Bar: Foo {
  |          +++++

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0380, E0599.
For more information about an error, try `rustc --explain E0380`.

I think the second error message should not come out, considering the Foo is an auto trait.