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Auto merge of #142085 - compiler-errors:perf-self-obl, r=lcnr

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Don't walk into `Certainty::Yes` goals

Don't walk into `Certainty::Yes` goals in the pending obligation finding code, since they will not have been stalled on an infer var anyways
This commit is contained in:
bors 2025-06-08 05:30:59 +00:00
commit 8072811356
1 changed files with 15 additions and 0 deletions
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15
compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
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@ -4,6 +4,7 @@ use rustc_infer::traits::{self, ObligationCause, PredicateObligations};
use rustc_middle::traits::solve::GoalSource;
use rustc_middle::ty::{self, Ty, TypeVisitableExt};
use rustc_span::Span;
use rustc_trait_selection::solve::Certainty;
use rustc_trait_selection::solve::inspect::{
InspectConfig, InspectGoal, ProofTreeInferCtxtExt, ProofTreeVisitor,
};
@ -117,6 +118,20 @@ impl<'a, 'tcx> ProofTreeVisitor<'tcx> for NestedObligationsForSelfTy<'a, 'tcx> {
}
fn visit_goal(&mut self, inspect_goal: &InspectGoal<'_, 'tcx>) {
// No need to walk into goal subtrees that certainly hold, since they
// wouldn't then be stalled on an infer var.
// FIXME: We also walk into normalizes-to goals since their certainty
// is forced to `Certainty::Yes` since they pass down ambiguous subgoals
// to their parent.
if inspect_goal.result() == Ok(Certainty::Yes)
&& !matches!(
inspect_goal.goal().predicate.kind().skip_binder(),
ty::PredicateKind::NormalizesTo(_)
)
{
return;
}
let tcx = self.fcx.tcx;
let goal = inspect_goal.goal();
if self.fcx.predicate_has_self_ty(goal.predicate, self.self_ty)