type parameter out of range when substituting

[xxchan]

Code

// It's complicated and I will try to minimize it later...

The source code is here https://github.com/risingwavelabs/risingwave/blob/xxchan/bump/src/storage/src/hummock/state_store.rs#L445

The error can be seen here https://buildkite.com/risingwavelabs/pull-request/builds/7684#01830ff8-131b-4859-b1f7-c715704e5540

risingwavelabs/risingwave#5119

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `(): store::IterFutureTrait`
#1 [typeck] type-checking `hummock::state_store::<impl at src/storage/src/hummock/state_store.rs:445:1: 445:35>::iter`
#2 [type_of] computing type of `hummock::state_store::<impl at src/storage/src/hummock/state_store.rs:445:1: 445:35>::GetFuture::{opaque#0}`
#3 [check_mod_item_types] checking item types in module `hummock::state_store`
#4 [analysis] running analysis passes on this crate
end of query stack

Meta

rustc --version --verbose:

rustc 1.65.0-nightly (289279de1 2022-09-04)
binary: rustc
commit-hash: 289279de116707f28cf9c18e4bbb8c6ec84ad75b
commit-date: 2022-09-04
host: aarch64-apple-darwin
release: 1.65.0-nightly
LLVM version: 15.0.0

Error output

error: internal compiler error: compiler/rustc_middle/src/ty/subst.rs:632:9: type parameter `I/#2` (I/2) out of range when substituting, substs=[()]

Backtrace

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/289279de116707f28cf9c18e4bbb8c6ec84ad75b/compiler/rustc_errors/src/lib.rs:1465:9
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: std::panic::panic_any::<rustc_errors::ExplicitBug>
   2: <rustc_errors::HandlerInner>::bug::<&alloc::string::String>
   3: <rustc_errors::Handler>::bug::<&alloc::string::String>
   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::opt_span_bug_fmt::<rustc_span::span_encoding::Span>
   6: rustc_middle::util::bug::bug_fmt
   7: <rustc_middle::ty::subst::SubstFolder>::type_param_out_of_range
   8: <rustc_middle::ty::subst::SubstFolder as rustc_middle::ty::fold::TypeFolder>::fold_ty
   9: <&rustc_middle::ty::list::List<rustc_middle::ty::subst::GenericArg> as rustc_middle::ty::fold::TypeFoldable>::try_fold_with::<rustc_middle::ty::subst::SubstFolder>
  10: <rustc_middle::ty::Ty as rustc_middle::ty::fold::TypeSuperFoldable>::super_fold_with::<rustc_middle::ty::subst::SubstFolder>
  11: <rustc_middle::ty::PredicateKind as rustc_middle::ty::fold::TypeFoldable>::try_fold_with::<rustc_middle::ty::subst::SubstFolder>
  12: <rustc_middle::ty::subst::SubstFolder as rustc_middle::ty::fold::FallibleTypeFolder>::try_fold_binder::<rustc_middle::ty::PredicateKind>
  13: <rustc_trait_selection::traits::select::SelectionContext>::impl_or_trait_obligations
  14: <rustc_trait_selection::traits::select::SelectionContext>::confirm_candidate
  15: <rustc_infer::infer::InferCtxt>::probe::<core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>, <rustc_trait_selection::traits::select::SelectionContext>::evaluation_probe<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_candidate::{closure#0}::{closure#0}>::{closure#0}>
  16: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_stack
  17: <rustc_middle::dep_graph::dep_node::DepKind as rustc_query_system::dep_graph::DepKind>::with_deps::<<rustc_trait_selection::traits::select::SelectionContext>::in_task<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#2}, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>::{closure#0}, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>
  18: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_anon_task::<rustc_middle::ty::context::TyCtxt, <rustc_trait_selection::traits::select::SelectionContext>::in_task<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively::{closure#0}::{closure#2}, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>::{closure#0}, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>
  19: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  20: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_predicate_recursively
  21: <rustc_infer::infer::InferCtxt>::probe::<core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>, <rustc_trait_selection::traits::select::SelectionContext>::evaluation_probe<<rustc_trait_selection::traits::select::SelectionContext>::evaluate_root_obligation::{closure#0}>::{closure#0}>
  22: <rustc_trait_selection::traits::select::SelectionContext>::evaluate_root_obligation
  23: <rustc_infer::infer::InferCtxtBuilder>::enter_with_canonical::<rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::Predicate>, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>, rustc_traits::evaluate_obligation::evaluate_obligation::{closure#0}>
  24: rustc_traits::evaluate_obligation::evaluate_obligation
  25: <rustc_middle::dep_graph::dep_node::DepKind as rustc_query_system::dep_graph::DepKind>::with_deps::<<rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task_impl<rustc_middle::ty::context::TyCtxt, rustc_middle::infer::canonical::Canonical<rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::Predicate>>, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>::{closure#0}, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>
  26: <rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::with_task::<rustc_middle::ty::context::TyCtxt, rustc_middle::infer::canonical::Canonical<rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::Predicate>>, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>
  27: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_middle::infer::canonical::Canonical<rustc_middle::ty::ParamEnvAnd<rustc_middle::ty::Predicate>>, core::result::Result<rustc_middle::traits::select::EvaluationResult, rustc_middle::traits::select::OverflowError>>>
  28: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::evaluate_obligation, rustc_query_impl::plumbing::QueryCtxt>
  29: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::evaluate_obligation
  30: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation
  31: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::evaluate_obligation_no_overflow
  32: <rustc_infer::infer::InferCtxt as rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt>::predicate_must_hold_modulo_regions
  33: <rustc_typeck::check::fn_ctxt::FnCtxt>::opt_suggest_box_span
  34: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_match::{closure#0}
  35: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_kind
  36: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  37: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_stmt
  38: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_block_with_expected
  39: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_kind
  40: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  41: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_kind
  42: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  43: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_stmt
  44: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_block_with_expected
  45: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_kind
  46: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  47: <rustc_typeck::check::fn_ctxt::FnCtxt>::check_return_expr
  48: rustc_typeck::check::check::check_fn
  49: <rustc_infer::infer::InferCtxtBuilder>::enter::<&rustc_middle::ty::context::TypeckResults, <rustc_typeck::check::inherited::InheritedBuilder>::enter<rustc_typeck::check::typeck_with_fallback<rustc_typeck::check::typeck::{closure#0}>::{closure#1}, &rustc_middle::ty::context::TypeckResults>::{closure#0}>
  50: rustc_typeck::check::typeck
  51: <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::ty::context::TypeckResults>
  52: 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::ty::context::TypeckResults>>
  53: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::typeck, rustc_query_impl::plumbing::QueryCtxt>
  54: <rustc_typeck::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator>::check
  55: rustc_hir::intravisit::walk_item::<rustc_typeck::collect::type_of::find_opaque_ty_constraints_for_tait::ConstraintLocator>
  56: rustc_typeck::collect::type_of::find_opaque_ty_constraints_for_tait
  57: rustc_typeck::collect::type_of::type_of
  58: <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>
  59: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_span::def_id::DefId, rustc_middle::ty::Ty>>
  60: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::type_of, rustc_query_impl::plumbing::QueryCtxt>
  61: rustc_typeck::check::check::check_opaque
  62: rustc_typeck::check::check::check_item_type
  63: rustc_typeck::check::check::check_mod_item_types
  64: <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, ()>
  65: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_span::def_id::LocalDefId, ()>>
  66: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::check_mod_item_types, rustc_query_impl::plumbing::QueryCtxt>
  67: <rustc_middle::hir::map::Map>::for_each_module::<rustc_typeck::check_crate::{closure#6}::{closure#0}>
  68: <rustc_session::session::Session>::time::<(), rustc_typeck::check_crate::{closure#6}>
  69: rustc_typeck::check_crate
  70: rustc_interface::passes::analysis
  71: <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::ErrorGuaranteed>>
  72: rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<(), core::result::Result<(), rustc_errors::ErrorGuaranteed>>>
  73: rustc_query_system::query::plumbing::get_query::<rustc_query_impl::queries::analysis, rustc_query_impl::plumbing::QueryCtxt>
  74: <rustc_interface::passes::QueryContext>::enter::<rustc_driver::run_compiler::{closure#1}::{closure#2}::{closure#3}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
  75: <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::ErrorGuaranteed>>
  76: rustc_span::with_source_map::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_interface::interface::create_compiler_and_run<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#1}>
  77: rustc_interface::interface::create_compiler_and_run::<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>
  78: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::interface::run_compiler<core::result::Result<(), rustc_errors::ErrorGuaranteed>, rustc_driver::run_compiler::{closure#1}>::{closure#0}, core::result::Result<(), rustc_errors::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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 1.65.0-nightly (289279de1 2022-09-04) running on aarch64-apple-darwin

note: compiler flags: --crate-type lib -C lto=off -C embed-bitcode=no -C split-debuginfo=unpacked -C debuginfo=2 -C incremental

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [evaluate_obligation] evaluating trait selection obligation `(): store::IterFutureTrait`
#1 [typeck] type-checking `hummock::state_store::<impl at src/storage/src/hummock/state_store.rs:445:1: 445:35>::iter`
#2 [type_of] computing type of `hummock::state_store::<impl at src/storage/src/hummock/state_store.rs:445:1: 445:35>::GetFuture::{opaque#0}`
#3 [check_mod_item_types] checking item types in module `hummock::state_store`
#4 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `risingwave_storage`

[compiler-errors]

Minimized:

#![feature(trait_alias)]

struct B;

struct C;

trait Tr2<S> = Into<S>;

fn foo2<T: Tr2<()>>() {}

fn foo() -> impl Sized {
    let x = foo2::<_>();

    match true {
        true => B,
        false => C,
    }
}

The logic in opt_suggest_box_span is super broken. First, we're calling it on non-error paths (which is probably inefficient), it's throwing away the non-Self substs on the predicates it's checking, it doesn't really make sense why it works at all¹ since it's trying to check literally all pending predicates in the FulfillmentContext, etc.... 😕 I am going to totally rewrite that logic.

@rustbot claim

^1. This is probably because this has gone through a couple of impl Trait rewrites and refactors...

[xxchan]

Thanks for your incredible work! The ICE doesn't occur in our code anymore.