Super visitor

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -219,14 +219,14 @@ fn fulfillment_error_for_no_solution<'tcx>(
  }
  ty::PredicateKind::Subtype(pred) => {
  let (a, b) = infcx.enter_forall_and_leak_universe(
- root_obligation.predicate.kind().rebind((pred.a, pred.b)),
+ obligation.predicate.kind().rebind((pred.a, pred.b)),
  );
  let expected_found = ExpectedFound::new(true, a, b);
  FulfillmentErrorCode::SubtypeError(expected_found, TypeError::Sorts(expected_found))
  }
  ty::PredicateKind::Coerce(pred) => {
  let (a, b) = infcx.enter_forall_and_leak_universe(
- root_obligation.predicate.kind().rebind((pred.a, pred.b)),
+ obligation.predicate.kind().rebind((pred.a, pred.b)),
  );
  let expected_found = ExpectedFound::new(false, a, b);
  FulfillmentErrorCode::SubtypeError(expected_found, TypeError::Sorts(expected_found))
@@ -298,13 +298,8 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
  }
 
  fn visit_goal(&mut self, goal: &super::inspect::InspectGoal<'_, 'tcx>) -> Self::Result {
- let candidates = goal.candidates();
  // FIXME: Throw out candidates that have no failing WC and >1 failing misc goal.
-
- // HACK:
- if self.obligation.recursion_depth > 3 {
- return ControlFlow::Break(self.obligation.clone());
- }
+ let candidates = goal.candidates();
 
  let [candidate] = candidates.as_slice() else {
  return ControlFlow::Break(self.obligation.clone());
@@ -376,7 +371,7 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
  recursion_depth: self_.obligation.recursion_depth + 1,
  }
  },
- |self_| self_.visit_goal(&nested_goal),
+ |self_| nested_goal.visit_with(self),
  )?;
  }
 

compiler/rustc_trait_selection/src/solve/inspect/analyse.rs

@@ -360,6 +360,14 @@ impl<'a, 'tcx> InspectGoal<'a, 'tcx> {
  source,
  }
  }
+
+ pub(crate) fn visit_with<V: ProofTreeVisitor<'tcx>>(&self, visitor: &mut V) -> V::Result {
+ if self.goal.depth < visitor.config().max_depth {
+ try_visit!(visitor.visit_goal(self));
+ }
+
+ V::Result::output()
+ }
 }
 
 /// The public API to interact with proof trees.