ICE "only ConstKind::Param should be encountered here"

[jruderman]

Found with a modified fuzz-rustc

Code

fn f() -> impl {
    2E
}
fn main() {}

Error output

error: expected at least one digit in exponent
error: at least one trait must be specified
error: internal compiler error: compiler/rustc_mir_transform/src/required_consts.rs:21:22: only ConstKind::Param should be encountered here, got Const { ty: f64, kind: Error(ErrorGuaranteed(())) }

Full output including backtrace

error: expected at least one digit in exponent
 --> a.rs:2:5
  |
2 |     2E
  |     ^^

error: at least one trait must be specified
 --> a.rs:1:11
  |
1 | fn f() -> impl {
  |           ^^^^

error: internal compiler error: compiler/rustc_mir_transform/src/required_consts.rs:21:22: only ConstKind::Param should be encountered here, got Const { ty: f64, kind: Error(ErrorGuaranteed(())) }

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/7eef946fc0e0eff40e588eab77b09b287accbec3/compiler/rustc_errors/src/lib.rs:1551:9
stack backtrace:
   0:        0x10db287a2 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hde9930b8710af522
   1:        0x10db805ea - core::fmt::write::hd25ec0bfc1849a2f
   2:        0x10db1a87c - std::io::Write::write_fmt::hca36d7396c5dc18b
   3:        0x10db2856a - std::sys_common::backtrace::print::hc155979e9e33e658
   4:        0x10db2b946 - std::panicking::default_hook::{{closure}}::h03db778ae686f347
   5:        0x10db2b697 - std::panicking::default_hook::h0d9e8bcb55be071f
   6:        0x11ccc17dd - rustc_driver[77a613ab63d15aac]::DEFAULT_HOOK::{closure#0}::{closure#0}
   7:        0x10db2c145 - std::panicking::rust_panic_with_hook::h758520931cfdfde5
   8:        0x121447b87 - std[11391ffec397fd56]::panicking::begin_panic::<rustc_errors[ec87cacb996b1da1]::ExplicitBug>::{closure#0}
   9:        0x1214472f9 - std[11391ffec397fd56]::sys_common::backtrace::__rust_end_short_backtrace::<std[11391ffec397fd56]::panicking::begin_panic<rustc_errors[ec87cacb996b1da1]::ExplicitBug>::{closure#0}, !>
  10:        0x121aefdf9 - std[11391ffec397fd56]::panicking::begin_panic::<rustc_errors[ec87cacb996b1da1]::ExplicitBug>
  11:        0x12143fee9 - std[11391ffec397fd56]::panic::panic_any::<rustc_errors[ec87cacb996b1da1]::ExplicitBug>
  12:        0x12143fc4d - <rustc_errors[ec87cacb996b1da1]::HandlerInner>::bug::<&alloc[a05f3e7fdaf4d80f]::string::String>
  13:        0x12143f717 - <rustc_errors[ec87cacb996b1da1]::Handler>::bug::<&alloc[a05f3e7fdaf4d80f]::string::String>
  14:        0x12159b3d2 - rustc_middle[b315a0ebd84f913d]::ty::context::tls::with_context_opt::<rustc_middle[b315a0ebd84f913d]::ty::context::tls::with_opt<rustc_middle[b315a0ebd84f913d]::util::bug::opt_span_bug_fmt<rustc_span[48482e0f8f724117]::span_encoding::Span>::{closure#0}, ()>::{closure#0}, ()>
  15:        0x12159c331 - rustc_middle[b315a0ebd84f913d]::util::bug::opt_span_bug_fmt::<rustc_span[48482e0f8f724117]::span_encoding::Span>
  16:        0x121af17ae - rustc_middle[b315a0ebd84f913d]::util::bug::bug_fmt
  17:        0x11fa9438a - <rustc_mir_transform[908f959bb72ad5af]::required_consts::RequiredConstsVisitor as rustc_middle[b315a0ebd84f913d]::mir::visit::Visitor>::visit_operand
  18:        0x11fa946eb - <rustc_mir_transform[908f959bb72ad5af]::required_consts::RequiredConstsVisitor as rustc_middle[b315a0ebd84f913d]::mir::visit::Visitor>::visit_basic_block_data
  19:        0x11f9ffb29 - rustc_mir_transform[908f959bb72ad5af]::mir_promoted
  20:        0x1205020e0 - rustc_query_system[69ea88315c8057f7]::query::plumbing::try_execute_query::<rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt, rustc_query_system[69ea88315c8057f7]::query::caches::DefaultCache<rustc_middle[b315a0ebd84f913d]::ty::WithOptConstParam<rustc_span[48482e0f8f724117]::def_id::LocalDefId>, (&rustc_data_structures[d9a04b93d3448b55]::steal::Steal<rustc_middle[b315a0ebd84f913d]::mir::Body>, &rustc_data_structures[d9a04b93d3448b55]::steal::Steal<rustc_index[975aea96e92c3aa6]::vec::IndexVec<rustc_middle[b315a0ebd84f913d]::mir::Promoted, rustc_middle[b315a0ebd84f913d]::mir::Body>>)>>
  21:        0x1206188c8 - rustc_query_system[69ea88315c8057f7]::query::plumbing::get_query::<rustc_query_impl[44c1f9c305efea75]::queries::mir_promoted, rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt>
  22:        0x1206d2e87 - <rustc_query_impl[44c1f9c305efea75]::Queries as rustc_middle[b315a0ebd84f913d]::ty::query::QueryEngine>::mir_promoted
  23:        0x1200a9996 - rustc_borrowck[92a4f20c78c2d7a9]::mir_borrowck
  24:        0x12008a685 - <rustc_borrowck[92a4f20c78c2d7a9]::provide::{closure#0} as core[cfd2f0869b685cd6]::ops::function::FnOnce<(rustc_middle[b315a0ebd84f913d]::ty::context::TyCtxt, rustc_span[48482e0f8f724117]::def_id::LocalDefId)>>::call_once
  25:        0x1205307c9 - rustc_query_system[69ea88315c8057f7]::query::plumbing::try_execute_query::<rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt, rustc_query_system[69ea88315c8057f7]::query::caches::DefaultCache<rustc_span[48482e0f8f724117]::def_id::LocalDefId, &rustc_middle[b315a0ebd84f913d]::mir::query::BorrowCheckResult>>
  26:        0x120618633 - rustc_query_system[69ea88315c8057f7]::query::plumbing::get_query::<rustc_query_impl[44c1f9c305efea75]::queries::mir_borrowck, rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt>
  27:        0x11f7e1f6a - rustc_hir_analysis[ad14f4770cb1b48d]::collect::type_of::find_opaque_ty_constraints_for_rpit
  28:        0x11f7e105d - rustc_hir_analysis[ad14f4770cb1b48d]::collect::type_of::type_of
  29:        0x1205549a5 - rustc_query_system[69ea88315c8057f7]::query::plumbing::try_execute_query::<rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt, rustc_query_system[69ea88315c8057f7]::query::caches::DefaultCache<rustc_span[48482e0f8f724117]::def_id::DefId, rustc_middle[b315a0ebd84f913d]::ty::Ty>>
  30:        0x12062be04 - rustc_query_system[69ea88315c8057f7]::query::plumbing::get_query::<rustc_query_impl[44c1f9c305efea75]::queries::type_of, rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt>
  31:        0x11f7903aa - rustc_hir_analysis[ad14f4770cb1b48d]::check::check::check_item_type
  32:        0x11f79ab0e - rustc_hir_analysis[ad14f4770cb1b48d]::check::check::check_mod_item_types
  33:        0x120533e45 - rustc_query_system[69ea88315c8057f7]::query::plumbing::try_execute_query::<rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt, rustc_query_system[69ea88315c8057f7]::query::caches::DefaultCache<rustc_span[48482e0f8f724117]::def_id::LocalDefId, ()>>
  34:        0x120621d05 - rustc_query_system[69ea88315c8057f7]::query::plumbing::get_query::<rustc_query_impl[44c1f9c305efea75]::queries::check_mod_item_types, rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt>
  35:        0x11f7bf828 - <rustc_middle[b315a0ebd84f913d]::hir::map::Map>::for_each_module::<rustc_hir_analysis[ad14f4770cb1b48d]::check_crate::{closure#6}::{closure#0}>
  36:        0x11f7aee79 - <rustc_session[ae5bb785c2cd4c22]::session::Session>::time::<(), rustc_hir_analysis[ad14f4770cb1b48d]::check_crate::{closure#6}>
  37:        0x11f75ac8f - rustc_hir_analysis[ad14f4770cb1b48d]::check_crate
  38:        0x11ce0884a - rustc_interface[a0d981abc9377f30]::passes::analysis
  39:        0x1205b1b5c - rustc_query_system[69ea88315c8057f7]::query::plumbing::try_execute_query::<rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt, rustc_query_system[69ea88315c8057f7]::query::caches::DefaultCache<(), core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>>
  40:        0x12062bf19 - rustc_query_system[69ea88315c8057f7]::query::plumbing::get_query::<rustc_query_impl[44c1f9c305efea75]::queries::analysis, rustc_query_impl[44c1f9c305efea75]::plumbing::QueryCtxt>
  41:        0x11ccdd7e6 - <rustc_interface[a0d981abc9377f30]::passes::QueryContext>::enter::<rustc_driver[77a613ab63d15aac]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>
  42:        0x11cd21f5d - rustc_span[48482e0f8f724117]::with_source_map::<core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>, rustc_interface[a0d981abc9377f30]::interface::run_compiler<core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>, rustc_driver[77a613ab63d15aac]::run_compiler::{closure#1}>::{closure#0}::{closure#1}>
  43:        0x11cd11a7c - <scoped_tls[46b3c18c0a12f0bc]::ScopedKey<rustc_span[48482e0f8f724117]::SessionGlobals>>::set::<rustc_interface[a0d981abc9377f30]::interface::run_compiler<core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>, rustc_driver[77a613ab63d15aac]::run_compiler::{closure#1}>::{closure#0}, core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>
  44:        0x11cce13ca - std[11391ffec397fd56]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[a0d981abc9377f30]::util::run_in_thread_pool_with_globals<rustc_interface[a0d981abc9377f30]::interface::run_compiler<core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>, rustc_driver[77a613ab63d15aac]::run_compiler::{closure#1}>::{closure#0}, core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>
  45:        0x11ccc74cb - <<std[11391ffec397fd56]::thread::Builder>::spawn_unchecked_<rustc_interface[a0d981abc9377f30]::util::run_in_thread_pool_with_globals<rustc_interface[a0d981abc9377f30]::interface::run_compiler<core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>, rustc_driver[77a613ab63d15aac]::run_compiler::{closure#1}>::{closure#0}, core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[cfd2f0869b685cd6]::result::Result<(), rustc_errors[ec87cacb996b1da1]::ErrorGuaranteed>>::{closure#1} as core[cfd2f0869b685cd6]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  46:        0x10db351f7 - std::sys::unix::thread::Thread::new::thread_start::ha121f0b94f5d418a
  47:     0x7ff814d514e1 - __pthread_start

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 1.67.0-nightly (7eef946fc 2022-11-06) running on x86_64-apple-darwin

query stack during panic:
#0 [mir_promoted] processing MIR for `f`
#1 [mir_borrowck] borrow-checking `f`
#2 [type_of] computing type of `f::{opaque#0}`
#3 [check_mod_item_types] checking item types in top-level module
#4 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors

Regression

Regression in nightly-2022-09-18 from #98588 (@b-naber, @lcnr)

Bisect info

searched nightlies: from nightly-2022-09-04 to nightly-2022-11-07
regressed nightly: nightly-2022-09-18
searched commit range: 95a992a...98ad6a5
regressed commit: c524c7d

bisected with cargo-bisect-rustc v0.6.4

Host triple: x86_64-apple-darwin

Version

rustc 1.67.0-nightly (7eef946fc 2022-11-06)
binary: rustc
commit-hash: 7eef946fc0e0eff40e588eab77b09b287accbec3
commit-date: 2022-11-06
host: x86_64-apple-darwin
release: 1.67.0-nightly
LLVM version: 15.0.4

[compiler-errors]

For the record, this isn't dependent on -> impl return type, which is a separate error. This also ICEs:

fn f() -> impl Sized {
    2E
}

fn main() {}

[chenyukang]

This don't ICE:

trait Demo {}

fn f() -> impl Demo {
    2E
}

fn main() {}

I guess it's because terminated because the error type error.

[compiler-errors]

Yeah, f64 still needs to implement the trait in the impl Trait -- this ICEs, for example:

trait Demo {}

impl Demo for f64 {}

fn f() -> impl Demo {
    2E
}

fn main() {}

[b-naber]

I can take a look at this, unless you're already working on this @compiler-errors.

[Rageking8]

@b-naber I think compiler-errors already submitted a PR to fix this, #104233

• PR linked above, but he did not claim this issue.

[b-naber]

Oh thanks, didn't see this.