diff options
Diffstat (limited to 'compiler/rustc_traits/src/evaluate_obligation.rs')
-rw-r--r-- | compiler/rustc_traits/src/evaluate_obligation.rs | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/compiler/rustc_traits/src/evaluate_obligation.rs b/compiler/rustc_traits/src/evaluate_obligation.rs new file mode 100644 index 000000000..49c9ba459 --- /dev/null +++ b/compiler/rustc_traits/src/evaluate_obligation.rs @@ -0,0 +1,34 @@ +use rustc_infer::infer::{DefiningAnchor, TyCtxtInferExt}; +use rustc_middle::ty::query::Providers; +use rustc_middle::ty::{ParamEnvAnd, TyCtxt}; +use rustc_span::source_map::DUMMY_SP; +use rustc_trait_selection::traits::query::CanonicalPredicateGoal; +use rustc_trait_selection::traits::{ + EvaluationResult, Obligation, ObligationCause, OverflowError, SelectionContext, TraitQueryMode, +}; + +pub(crate) fn provide(p: &mut Providers) { + *p = Providers { evaluate_obligation, ..*p }; +} + +fn evaluate_obligation<'tcx>( + tcx: TyCtxt<'tcx>, + canonical_goal: CanonicalPredicateGoal<'tcx>, +) -> Result<EvaluationResult, OverflowError> { + debug!("evaluate_obligation(canonical_goal={:#?})", canonical_goal); + // HACK This bubble is required for this tests to pass: + // impl-trait/issue99642.rs + tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bubble).enter_with_canonical( + DUMMY_SP, + &canonical_goal, + |ref infcx, goal, _canonical_inference_vars| { + debug!("evaluate_obligation: goal={:#?}", goal); + let ParamEnvAnd { param_env, value: predicate } = goal; + + let mut selcx = SelectionContext::with_query_mode(&infcx, TraitQueryMode::Canonical); + let obligation = Obligation::new(ObligationCause::dummy(), param_env, predicate); + + selcx.evaluate_root_obligation(&obligation) + }, + ) +} |