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ICE on wrong generator yield/return type when using type_alias_impl_trait #94429

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@henryksloan

Description

@henryksloan

Possibly related to #87142 as both ICEs arise from Box<dyn Any>, but this ICE occurs on a different line.

Code

#![feature(type_alias_impl_trait, generator_trait, generators)]
use std::ops::Generator;

trait Runnable {
    type Gen: Generator<Yield = (), Return = ()>;

    fn run(&mut self) -> Self::Gen;
}

struct Implementor {}

impl Runnable for Implementor {
    type Gen = impl Generator<Yield = (), Return = ()>;

    fn run(&mut self) -> Self::Gen {
        move || {
            // This line causes the ICE;
            // the same error occurs if the return type is wrong (e.g. `return 1`)
            yield 1;
        }
    }
}

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rustc --version --verbose:

rustc 1.61.0-nightly (10cc7a6d0 2022-02-26)
binary: rustc
commit-hash: 10cc7a6d031fd607f594f4c7af113bfaa9a879e9
commit-date: 2022-02-26
host: x86_64-unknown-linux-gnu
release: 1.61.0-nightly
LLVM version: 14.0.0

Error output

error: internal compiler error: compiler/rustc_borrowck/src/universal_regions.rs:547:26: expected defining type for `DefId(0:14 ~ generator_existential_types[3c81]::{impl#0}::run::{closure#0})`: `[type error]`
Backtrace

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/10cc7a6d031fd607f594f4c7af113bfaa9a879e9/compiler/rustc_errors/src/lib.rs:1102:9
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: std::panic::panic_any::<rustc_errors::ExplicitBug>
   2: <rustc_errors::HandlerInner>::span_bug::<rustc_span::span_encoding::Span>
   3: <rustc_errors::Handler>::span_bug::<rustc_span::span_encoding::Span>
   4: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, ()>
   5: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>
   6: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   7: <rustc_borrowck::universal_regions::UniversalRegions>::new
   8: rustc_borrowck::do_mir_borrowck
   9: <rustc_borrowck::provide::{closure#0} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId)>>::call_once
  10: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId, &rustc_middle::mir::query::BorrowCheckResult>
  11: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_span::def_id::LocalDefId, &rustc_middle::mir::query::BorrowCheckResult>>
  12: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::mir_borrowck
  13: <rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator>::check
  14: <rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator as rustc_hir::intravisit::Visitor>::visit_expr
  15: <rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator as rustc_hir::intravisit::Visitor>::visit_nested_body
  16: rustc_hir::intravisit::walk_impl_item::<rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator>
  17: <rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator as rustc_hir::intravisit::Visitor>::visit_nested_impl_item
  18: rustc_hir::intravisit::walk_item::<rustc_typeck::collect::type_of::find_opaque_ty_constraints::ConstraintLocator>
  19: rustc_typeck::collect::type_of::find_opaque_ty_constraints
  20: rustc_typeck::collect::type_of::type_of
  21: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, rustc_span::def_id::DefId, rustc_middle::ty::Ty>
  22: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::type_of, rustc_query_impl::plumbing::QueryCtxt>
  23: rustc_typeck::check::check::check_item_type
  24: <rustc_middle::hir::map::Map>::visit_item_likes_in_module::<rustc_typeck::check::CheckItemTypesVisitor>
  25: rustc_typeck::check::check::check_mod_item_types
  26: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, rustc_span::def_id::LocalDefId, ()>
  27: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_span::def_id::LocalDefId, ()>>
  28: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::check_mod_item_types, rustc_query_impl::plumbing::QueryCtxt>
  29: <rustc_middle::hir::map::Map>::for_each_module::<rustc_typeck::check_crate::{closure#6}::{closure#0}>
  30: rustc_typeck::check_crate
  31: rustc_interface::passes::analysis
  32: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, (), core::result::Result<(), rustc_errors::ErrorReported>>
  33: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<(), core::result::Result<(), rustc_errors::ErrorReported>>>
  34: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::analysis, rustc_query_impl::plumbing::QueryCtxt>
  35: <rustc_interface::passes::QueryContext>::enter::<rustc_driver::run_compiler::{closure#1}::{closure#2}::{closure#3}, core::result::Result<(), rustc_errors::ErrorReported>>
  36: <rustc_interface::interface::Compiler>::enter::<rustc_driver::run_compiler::{closure#1}::{closure#2}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_errors::ErrorReported>>
  37: rustc_span::with_source_map::<core::result::Result<(), rustc_errors::ErrorReported>, rustc_interface::interface::create_compiler_and_run<core::result::Result<(), rustc_errors::ErrorReported>, rustc_driver::run_compiler::{closure#1}>::{closure#1}>
  38: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorReported>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorReported>>

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    A-impl-traitArea: `impl Trait`. Universally / existentially quantified anonymous types with static dispatch.C-bugCategory: This is a bug.E-needs-testCall for participation: An issue has been fixed and does not reproduce, but no test has been added.F-type_alias_impl_trait`#[feature(type_alias_impl_trait)]`I-ICEIssue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️T-compilerRelevant to the compiler team, which will review and decide on the PR/issue.glacierICE tracked in rust-lang/glacier.

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