Rollup merge of #123477 - lcnr:forced_ambig-no-ice, r=compiler-errors

do not ICE in `fn forced_ambiguity` if we get an error

see the comment. currently causing an ICE in typenum which we've been unable to minimize.

r? `@compiler-errors`
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Jacob Pratt 2024-04-04 21:16:58 -04:00 committed by GitHub
commit e01d3e0824
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@ -312,11 +312,18 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
fn forced_ambiguity(&mut self, cause: MaybeCause) -> Vec<Candidate<'tcx>> {
let source = CandidateSource::BuiltinImpl(BuiltinImplSource::Misc);
let certainty = Certainty::Maybe(cause);
let result = self.evaluate_added_goals_and_make_canonical_response(certainty).unwrap();
// This may fail if `try_evaluate_added_goals` overflows because it
// fails to reach a fixpoint but ends up getting an error after
// running for some additional step.
//
// FIXME: Add a test for this. It seems to be necessary for typenum but
// is incredibly hard to minimize as it may rely on being inside of a
// trait solver cycle.
let result = self.evaluate_added_goals_and_make_canonical_response(certainty);
let mut dummy_probe = self.inspect.new_probe();
dummy_probe.probe_kind(ProbeKind::TraitCandidate { source, result: Ok(result) });
dummy_probe.probe_kind(ProbeKind::TraitCandidate { source, result });
self.inspect.finish_probe(dummy_probe);
vec![Candidate { source, result }]
if let Ok(result) = result { vec![Candidate { source, result }] } else { vec![] }
}
#[instrument(level = "debug", skip_all)]