ICE "wrong number of generic parameters" with abused auto trait

[jruderman]

Found with a modified fuzz-rustc

Code

#![feature(auto_traits)]

auto trait Trait1<'a> {}

fn f()
where
    for<'a> dyn Trait1<'a>: Sized,
{
}

fn main() {}

Error output with debug assertions enabled

error[E0567]: auto traits cannot have generic parameters
  |
3 | auto trait Trait1<'a> {}
  |            ------^^^^ help: remove the parameters
  |            |
  |            auto trait cannot have generic parameters

thread 'rustc' panicked at 'assertion failed: `(left == right)`
  left: `(2, Some(2))`,
 right: `(1, Some(1))`: wrong number of generic parameters for DefId(...Trait1): [FreshTy(0)]
Did you accidentally include the self-type in the params list?', compiler/rustc_middle/src/ty/context.rs:2827:9

Backtrace

stack backtrace:
   0:        0x10de9cf21 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hcf5aac4d53eab431
   1:        0x10df5a818 - core::fmt::write::hed31846cddb4e13c
   2:        0x10deffec8 - std::io::Write::write_fmt::h01887004f97cedc7
   3:        0x10de9cd12 - std::sys_common::backtrace::print::h2141c6543b5865e5
   4:        0x10df00e45 - std::panicking::default_hook::{{closure}}::hfe93a58a10a72158
   5:        0x10df00c2e - std::panicking::default_hook::hafca10424d622dfb
   6:        0x12248d708 - rustc_driver[bfe6130b33d7dd9c]::DEFAULT_HOOK::{closure#0}::{closure#0}
   7:        0x10df01636 - std::panicking::rust_panic_with_hook::hafe3bb82e805c420
   8:        0x10deee173 - std::panicking::begin_panic_handler::{{closure}}::h2797e20f8763cc3a
   9:        0x10deee0a8 - std::sys_common::backtrace::__rust_end_short_backtrace::hde7c42687ab67a11
  10:        0x10df00f18 - _rust_begin_unwind
  11:        0x10df7f443 - core::panicking::panic_fmt::h7ec57a9a63e6db71
  12:        0x10df6e125 - core::panicking::assert_failed_inner::hb961e0acdeb20af8
  13:        0x127af841e - core[95bb6d661b676f4d]::panicking::assert_failed::<(usize, core[95bb6d661b676f4d]::option::Option<usize>), (usize, core[95bb6d661b676f4d]::option::Option<usize>)>
  14:        0x1272f5616 - <rustc_middle[42f89e9b8d5efbfa]::ty::context::TyCtxt>::mk_trait_ref::<rustc_middle[42f89e9b8d5efbfa]::ty::Ty, [rustc_middle[42f89e9b8d5efbfa]::ty::Ty; 1usize]>
  15:        0x12733f32a - <rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>>::with_self_ty
  16:        0x126f72bd4 - <&mut rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds::{closure#0} as core[95bb6d661b676f4d]::ops::function::FnMut<(rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>,)>>::call_mut
  17:        0x126f66626 - <core[95bb6d661b676f4d]::iter::adapters::copied::Copied<core[95bb6d661b676f4d]::slice::iter::Iter<rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>>> as core[95bb6d661b676f4d]::iter::traits::iterator::Iterator>::try_fold::<(), core[95bb6d661b676f4d]::iter::traits::iterator::Iterator::find_map::check<rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>, rustc_middle[42f89e9b8d5efbfa]::ty::Predicate, &mut rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds::{closure#0}>::{closure#0}, core[95bb6d661b676f4d]::ops::control_flow::ControlFlow<rustc_middle[42f89e9b8d5efbfa]::ty::Predicate>>
  18:        0x126f20c55 - <alloc[fd2a8df82bfdc6c8]::vec::Vec<rustc_infer[7a2db91e787c07b]::traits::Obligation<rustc_middle[42f89e9b8d5efbfa]::ty::Predicate>> as alloc[fd2a8df82bfdc6c8]::vec::spec_from_iter::SpecFromIter<rustc_infer[7a2db91e787c07b]::traits::Obligation<rustc_middle[42f89e9b8d5efbfa]::ty::Predicate>, core[95bb6d661b676f4d]::iter::adapters::map::Map<core[95bb6d661b676f4d]::iter::adapters::filter_map::FilterMap<core[95bb6d661b676f4d]::iter::adapters::copied::Copied<core[95bb6d661b676f4d]::slice::iter::Iter<rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>>>, rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds::{closure#0}>, rustc_infer[7a2db91e787c07b]::traits::util::elaborate_predicates<core[95bb6d661b676f4d]::iter::adapters::filter_map::FilterMap<core[95bb6d661b676f4d]::iter::adapters::copied::Copied<core[95bb6d661b676f4d]::slice::iter::Iter<rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>>>, rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds::{closure#0}>>::{closure#0}>>>::from_iter
  19:        0x126f6406d - rustc_infer[7a2db91e787c07b]::traits::util::elaborate_predicates::<core[95bb6d661b676f4d]::iter::adapters::filter_map::FilterMap<core[95bb6d661b676f4d]::iter::adapters::copied::Copied<core[95bb6d661b676f4d]::slice::iter::Iter<rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>>>, rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds::{closure#0}>>
  20:        0x126f7346d - rustc_trait_selection[47a25601aa70e18]::traits::wf::required_region_bounds::<core[95bb6d661b676f4d]::iter::adapters::filter_map::FilterMap<core[95bb6d661b676f4d]::iter::adapters::copied::Copied<core[95bb6d661b676f4d]::slice::iter::Iter<rustc_middle[42f89e9b8d5efbfa]::ty::sty::Binder<rustc_middle[42f89e9b8d5efbfa]::ty::sty::ExistentialPredicate>>>, rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds::{closure#0}>>
  21:        0x126f3dd35 - rustc_trait_selection[47a25601aa70e18]::traits::wf::object_region_bounds
  22:        0x124ff43b0 - <dyn rustc_hir_analysis[4c308ea3b425d19e]::astconv::AstConv>::conv_object_ty_poly_trait_ref
  23:        0x1250006bb - <dyn rustc_hir_analysis[4c308ea3b425d19e]::astconv::AstConv>::ast_ty_to_ty_inner
  24:        0x12512bebd - rustc_hir_analysis[4c308ea3b425d19e]::collect::predicates_of::gather_explicit_predicates_of::{closure#0}
  25:        0x12512af53 - rustc_hir_analysis[4c308ea3b425d19e]::collect::predicates_of::gather_explicit_predicates_of
  26:        0x1251299cb - rustc_hir_analysis[4c308ea3b425d19e]::collect::predicates_of::explicit_predicates_of
  27:        0x126506991 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::try_execute_query::<rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt, rustc_query_system[2c5b580ea3a12206]::query::caches::DefaultCache<rustc_span[7d7aa17bf13bea16]::def_id::DefId, rustc_middle[42f89e9b8d5efbfa]::ty::generics::GenericPredicates>>
  28:        0x1265e9e39 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::get_query::<rustc_query_impl[e5b327371ad57e64]::queries::explicit_predicates_of, rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt>
  29:        0x126182457 - <rustc_query_impl[e5b327371ad57e64]::Queries as rustc_middle[42f89e9b8d5efbfa]::ty::query::QueryEngine>::explicit_predicates_of
  30:        0x124f4d74f - rustc_hir_analysis[4c308ea3b425d19e]::collect::predicates_defined_on
  31:        0x126506991 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::try_execute_query::<rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt, rustc_query_system[2c5b580ea3a12206]::query::caches::DefaultCache<rustc_span[7d7aa17bf13bea16]::def_id::DefId, rustc_middle[42f89e9b8d5efbfa]::ty::generics::GenericPredicates>>
  32:        0x1265e43c4 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::get_query::<rustc_query_impl[e5b327371ad57e64]::queries::predicates_defined_on, rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt>
  33:        0x1261816a7 - <rustc_query_impl[e5b327371ad57e64]::Queries as rustc_middle[42f89e9b8d5efbfa]::ty::query::QueryEngine>::predicates_defined_on
  34:        0x125129293 - rustc_hir_analysis[4c308ea3b425d19e]::collect::predicates_of::predicates_of
  35:        0x126506991 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::try_execute_query::<rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt, rustc_query_system[2c5b580ea3a12206]::query::caches::DefaultCache<rustc_span[7d7aa17bf13bea16]::def_id::DefId, rustc_middle[42f89e9b8d5efbfa]::ty::generics::GenericPredicates>>
  36:        0x1265c1110 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::get_query::<rustc_query_impl[e5b327371ad57e64]::queries::predicates_of, rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt>
  37:        0x126173757 - <rustc_query_impl[e5b327371ad57e64]::Queries as rustc_middle[42f89e9b8d5efbfa]::ty::query::QueryEngine>::predicates_of
  38:        0x124f422e9 - rustc_hir_analysis[4c308ea3b425d19e]::collect::convert_item
  39:        0x124f3f24c - <rustc_hir_analysis[4c308ea3b425d19e]::collect::CollectItemTypesVisitor as rustc_hir[112137b1c6e29e52]::intravisit::Visitor>::visit_item
  40:        0x125124675 - <rustc_middle[42f89e9b8d5efbfa]::hir::map::Map>::visit_item_likes_in_module::<rustc_hir_analysis[4c308ea3b425d19e]::collect::CollectItemTypesVisitor>
  41:        0x124f3e555 - rustc_hir_analysis[4c308ea3b425d19e]::collect::collect_mod_item_types
  42:        0x1264e6f1e - rustc_query_system[2c5b580ea3a12206]::query::plumbing::try_execute_query::<rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt, rustc_query_system[2c5b580ea3a12206]::query::caches::DefaultCache<rustc_span[7d7aa17bf13bea16]::def_id::LocalDefId, ()>>
  43:        0x1265e7093 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::get_query::<rustc_query_impl[e5b327371ad57e64]::queries::collect_mod_item_types, rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt>
  44:        0x1261956cf - <rustc_query_impl[e5b327371ad57e64]::Queries as rustc_middle[42f89e9b8d5efbfa]::ty::query::QueryEngine>::collect_mod_item_types
  45:        0x125123fa6 - <rustc_middle[42f89e9b8d5efbfa]::hir::map::Map>::for_each_module::<rustc_hir_analysis[4c308ea3b425d19e]::check_crate::{closure#0}::{closure#0}::{closure#0}>
  46:        0x12506055b - <rustc_session[6f273c4587eb1b50]::session::Session>::track_errors::<rustc_hir_analysis[4c308ea3b425d19e]::check_crate::{closure#0}, ()>
  47:        0x124f8264c - rustc_hir_analysis[4c308ea3b425d19e]::check_crate
  48:        0x1225b828a - rustc_interface[fb7297f02cc960f4]::passes::analysis
  49:        0x12652c95f - rustc_query_system[2c5b580ea3a12206]::query::plumbing::try_execute_query::<rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt, rustc_query_system[2c5b580ea3a12206]::query::caches::DefaultCache<(), core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>>
  50:        0x126619589 - rustc_query_system[2c5b580ea3a12206]::query::plumbing::get_query::<rustc_query_impl[e5b327371ad57e64]::queries::analysis, rustc_query_impl[e5b327371ad57e64]::plumbing::QueryCtxt>
  51:        0x1261723b7 - <rustc_query_impl[e5b327371ad57e64]::Queries as rustc_middle[42f89e9b8d5efbfa]::ty::query::QueryEngine>::analysis
  52:        0x1224811db - <rustc_interface[fb7297f02cc960f4]::passes::QueryContext>::enter::<rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>
  53:        0x12247b688 - <rustc_interface[fb7297f02cc960f4]::interface::Compiler>::enter::<rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}::{closure#2}, core[95bb6d661b676f4d]::result::Result<core[95bb6d661b676f4d]::option::Option<rustc_interface[fb7297f02cc960f4]::queries::Linker>, rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>
  54:        0x1224792bb - rustc_span[7d7aa17bf13bea16]::with_source_map::<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, rustc_interface[fb7297f02cc960f4]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}>::{closure#0}::{closure#1}>
  55:        0x12244facc - <scoped_tls[c451c38e2ed76225]::ScopedKey<rustc_span[7d7aa17bf13bea16]::SessionGlobals>>::set::<rustc_interface[fb7297f02cc960f4]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>
  56:        0x122446240 - std[e4564114326e8c6]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[fb7297f02cc960f4]::util::run_in_thread_pool_with_globals<rustc_interface[fb7297f02cc960f4]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>
  57:        0x122478d90 - std[e4564114326e8c6]::panicking::try::<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, core[95bb6d661b676f4d]::panic::unwind_safe::AssertUnwindSafe<<std[e4564114326e8c6]::thread::Builder>::spawn_unchecked_<rustc_interface[fb7297f02cc960f4]::util::run_in_thread_pool_with_globals<rustc_interface[fb7297f02cc960f4]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>::{closure#1}::{closure#0}>>
  58:        0x122474141 - <<std[e4564114326e8c6]::thread::Builder>::spawn_unchecked_<rustc_interface[fb7297f02cc960f4]::util::run_in_thread_pool_with_globals<rustc_interface[fb7297f02cc960f4]::interface::run_compiler<core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>, rustc_driver[bfe6130b33d7dd9c]::run_compiler::{closure#1}>::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[95bb6d661b676f4d]::result::Result<(), rustc_errors[48ad5d4ad3523473]::ErrorGuaranteed>>::{closure#1} as core[95bb6d661b676f4d]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  59:        0x10deb6b5b - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd10a5c38d6c64916
  60:        0x10dea119f - std::sys::unix::thread::Thread::new::thread_start::he793914283faf21a
  61:     0x7ff816f934e1 - __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 1.67.0-dev running on x86_64-apple-darwin

query stack during panic:
#0 [explicit_predicates_of] computing explicit predicates of `f`
#1 [predicates_defined_on] computing predicates of `f`
#2 [predicates_of] computing predicates of `f`
#3 [collect_mod_item_types] collecting item types in top-level module
#4 [analysis] running analysis passes on this crate
end of query stack

Version

Built stage1 from 604d521 on x86_64-apple-darwin

config.toml

# Includes one of the default files in src/bootstrap/defaults
profile = "compiler"
changelog-seen = 2

[llvm]
download-ci-llvm = true     # Download a pre-built LLVM?
assertions = true           # LLVM assertions on?

[rust]
incremental = true          # Build rustc with incremental compilation?
debug-assertions = true
overflow-checks = true

CC @oli-obk because 7658e0f (part of #104533) changed the assertion condition

[oli-obk]

Oh fun! Glad we're catching this. It's probably going to be annoying to fix, but also not a priority considering this is about auto traits.

[compiler-errors]

This repro doesn't require debug assertions, or the feature gate:

auto trait Trait1<'a> {}

fn f<'a>(x: &dyn Trait1<'a>)
{}

fn main() {
    f(&1);
}