diff options
5 files changed, 132 insertions, 19 deletions
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs index b8cd94e5422..1049e7a8bbe 100644 --- a/compiler/rustc_borrowck/src/region_infer/mod.rs +++ b/compiler/rustc_borrowck/src/region_infer/mod.rs @@ -2249,7 +2249,14 @@ impl<'tcx> RegionInferenceContext<'tcx> { } pub(crate) fn universe_info(&self, universe: ty::UniverseIndex) -> UniverseInfo<'tcx> { - self.universe_causes[&universe].clone() + // Query canonicalization can create local superuniverses (for example in + // `InferCtx::query_response_substitution_guess`), but they don't have an associated + // `UniverseInfo` explaining why they were created. + // This can cause ICEs if these causes are accessed in diagnostics, for example in issue + // #114907 where this happens via liveness and dropck outlives results. + // Therefore, we return a default value in case that happens, which should at worst emit a + // suboptimal error, instead of the ICE. + self.universe_causes.get(&universe).cloned().unwrap_or_else(|| UniverseInfo::other()) } /// Tries to find the terminator of the loop in which the region 'r' resides. diff --git a/compiler/rustc_borrowck/src/type_check/canonical.rs b/compiler/rustc_borrowck/src/type_check/canonical.rs index 16f5e68a06f..b7adc314f07 100644 --- a/compiler/rustc_borrowck/src/type_check/canonical.rs +++ b/compiler/rustc_borrowck/src/type_check/canonical.rs @@ -9,7 +9,7 @@ use rustc_span::Span; use rustc_trait_selection::traits::query::type_op::{self, TypeOpOutput}; use rustc_trait_selection::traits::ObligationCause; -use crate::diagnostics::{ToUniverseInfo, UniverseInfo}; +use crate::diagnostics::ToUniverseInfo; use super::{Locations, NormalizeLocation, TypeChecker}; @@ -46,13 +46,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { self.push_region_constraints(locations, category, data); } + // If the query has created new universes and errors are going to be emitted, register the + // cause of these new universes for improved diagnostics. let universe = self.infcx.universe(); - - if old_universe != universe { - let universe_info = match error_info { - Some(error_info) => error_info.to_universe_info(old_universe), - None => UniverseInfo::other(), - }; + if old_universe != universe && let Some(error_info) = error_info { + let universe_info = error_info.to_universe_info(old_universe); for u in (old_universe + 1)..=universe { self.borrowck_context.constraints.universe_causes.insert(u, universe_info.clone()); } @@ -69,15 +67,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { where T: TypeFoldable<TyCtxt<'tcx>>, { - let old_universe = self.infcx.universe(); - let (instantiated, _) = self.infcx.instantiate_canonical_with_fresh_inference_vars(span, canonical); - - for u in (old_universe + 1)..=self.infcx.universe() { - self.borrowck_context.constraints.universe_causes.insert(u, UniverseInfo::other()); - } - instantiated } diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index 3004291c3e7..28286243e82 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -163,10 +163,6 @@ pub(crate) fn type_check<'mir, 'tcx>( debug!(?normalized_inputs_and_output); - for u in ty::UniverseIndex::ROOT..=infcx.universe() { - constraints.universe_causes.insert(u, UniverseInfo::other()); - } - let mut borrowck_context = BorrowCheckContext { universal_regions, location_table, diff --git a/tests/ui/nll/missing-universe-cause-issue-114907.rs b/tests/ui/nll/missing-universe-cause-issue-114907.rs new file mode 100644 index 00000000000..94acdccfcf2 --- /dev/null +++ b/tests/ui/nll/missing-universe-cause-issue-114907.rs @@ -0,0 +1,40 @@ +// This is a non-regression test for issue #114907 where an ICE happened because of missing +// `UniverseInfo`s accessed during diagnostics. +// +// A couple notes: +// - the `FnOnce` bounds need an arg that is a reference +// - a custom `Drop` is needed somewhere in the type that `accept` returns, to create universes +// during liveness and dropck outlives computation + +// check-fail + +trait Role { + type Inner; +} + +struct HandshakeCallback<C>(C); +impl<C: FnOnce(&())> Role for HandshakeCallback<C> { + type Inner = (); +} + +struct Handshake<R: Role> { + _inner: Option<R::Inner>, +} +impl<R: Role> Drop for Handshake<R> { + fn drop(&mut self) {} +} + +fn accept<C: FnOnce(&())>(_: C) -> Handshake<HandshakeCallback<C>> { + todo!() +} + +fn main() { + let callback = |_| {}; + accept(callback); + //~^ ERROR mismatched types + //~| ERROR mismatched types + //~| ERROR implementation of `FnOnce` is not general enough + //~| ERROR implementation of `FnOnce` is not general enough + //~| ERROR higher-ranked subtype error + //~| ERROR higher-ranked subtype error +} diff --git a/tests/ui/nll/missing-universe-cause-issue-114907.stderr b/tests/ui/nll/missing-universe-cause-issue-114907.stderr new file mode 100644 index 00000000000..c3dd4257a73 --- /dev/null +++ b/tests/ui/nll/missing-universe-cause-issue-114907.stderr @@ -0,0 +1,79 @@ +error[E0308]: mismatched types + --> $DIR/missing-universe-cause-issue-114907.rs:33:5 + | +LL | accept(callback); + | ^^^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected trait `for<'a> FnOnce<(&'a (),)>` + found trait `FnOnce<(&(),)>` +note: this closure does not fulfill the lifetime requirements + --> $DIR/missing-universe-cause-issue-114907.rs:32:20 + | +LL | let callback = |_| {}; + | ^^^ +note: the lifetime requirement is introduced here + --> $DIR/missing-universe-cause-issue-114907.rs:27:14 + | +LL | fn accept<C: FnOnce(&())>(_: C) -> Handshake<HandshakeCallback<C>> { + | ^^^^^^^^^^^ +help: consider specifying the type of the closure parameters + | +LL | let callback = |_: &_| {}; + | ~~~~~~~ + +error: implementation of `FnOnce` is not general enough + --> $DIR/missing-universe-cause-issue-114907.rs:33:5 + | +LL | accept(callback); + | ^^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough + | + = note: closure with signature `fn(&'2 ())` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`... + = note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2` + +error: implementation of `FnOnce` is not general enough + --> $DIR/missing-universe-cause-issue-114907.rs:33:5 + | +LL | accept(callback); + | ^^^^^^^^^^^^^^^^ implementation of `FnOnce` is not general enough + | + = note: closure with signature `fn(&'2 ())` must implement `FnOnce<(&'1 (),)>`, for any lifetime `'1`... + = note: ...but it actually implements `FnOnce<(&'2 (),)>`, for some specific lifetime `'2` + +error[E0308]: mismatched types + --> $DIR/missing-universe-cause-issue-114907.rs:33:5 + | +LL | accept(callback); + | ^^^^^^^^^^^^^^^^ one type is more general than the other + | + = note: expected trait `for<'a> FnOnce<(&'a (),)>` + found trait `FnOnce<(&(),)>` +note: this closure does not fulfill the lifetime requirements + --> $DIR/missing-universe-cause-issue-114907.rs:32:20 + | +LL | let callback = |_| {}; + | ^^^ +note: the lifetime requirement is introduced here + --> $DIR/missing-universe-cause-issue-114907.rs:20:21 + | +LL | struct Handshake<R: Role> { + | ^^^^ +help: consider specifying the type of the closure parameters + | +LL | let callback = |_: &_| {}; + | ~~~~~~~ + +error: higher-ranked subtype error + --> $DIR/missing-universe-cause-issue-114907.rs:33:21 + | +LL | accept(callback); + | ^ + +error: higher-ranked subtype error + --> $DIR/missing-universe-cause-issue-114907.rs:33:21 + | +LL | accept(callback); + | ^ + +error: aborting due to 6 previous errors + +For more information about this error, try `rustc --explain E0308`. |