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Walk into alias-eq nested goals even if normalization fails

This commit is contained in:
Michael Goulet 2024-05-28 14:50:22 -04:00
parent 8337ba9189
commit 52b2c88bdf
14 changed files with 83 additions and 22 deletions

View file

@ -48,6 +48,12 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
rhs
};
// Add a `make_canonical_response` probe step so that we treat this as
// a candidate, even if `try_evaluate_added_goals` bails due to an error.
// It's `Certainty::AMBIGUOUS` because this candidate is not "finished",
// since equating the normalized terms will lead to additional constraints.
self.inspect.make_canonical_response(Certainty::AMBIGUOUS);
// Apply the constraints.
self.try_evaluate_added_goals()?;
let lhs = self.resolve_vars_if_possible(lhs);

View file

@ -460,9 +460,8 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
polarity: ty::PredicatePolarity::Positive,
}))
}
ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(_)) => {
ChildMode::WellFormedObligation
}
ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(_))
| ty::PredicateKind::AliasRelate(..) => ChildMode::PassThrough,
_ => {
return ControlFlow::Break(self.obligation.clone());
}
@ -496,7 +495,7 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
(_, GoalSource::InstantiateHigherRanked) => {
obligation = self.obligation.clone();
}
(ChildMode::WellFormedObligation, _) => {
(ChildMode::PassThrough, _) => {
obligation = make_obligation(self.obligation.cause.clone());
}
}
@ -527,7 +526,7 @@ enum ChildMode<'tcx> {
// Skip trying to derive an `ObligationCause` from this obligation, and
// report *all* sub-obligations as if they came directly from the parent
// obligation.
WellFormedObligation,
PassThrough,
}
fn derive_cause<'tcx>(

View file

@ -15,7 +15,7 @@ use rustc_infer::infer::{DefineOpaqueTypes, InferCtxt, InferOk};
use rustc_macros::extension;
use rustc_middle::traits::query::NoSolution;
use rustc_middle::traits::solve::{inspect, QueryResult};
use rustc_middle::traits::solve::{Certainty, Goal};
use rustc_middle::traits::solve::{Certainty, Goal, MaybeCause};
use rustc_middle::traits::ObligationCause;
use rustc_middle::ty::{TyCtxt, TypeFoldable};
use rustc_middle::{bug, ty};
@ -291,7 +291,10 @@ impl<'a, 'tcx> InspectGoal<'a, 'tcx> {
steps.push(step)
}
inspect::ProbeStep::MakeCanonicalResponse { shallow_certainty: c } => {
assert_eq!(shallow_certainty.replace(c), None);
assert!(matches!(
shallow_certainty.replace(c),
None | Some(Certainty::Maybe(MaybeCause::Ambiguity))
));
}
inspect::ProbeStep::NestedProbe(ref probe) => {
match probe.kind {