Rollup merge of #104772 - GuillaumeGomez:small-accessibility-improvement, r=notriddle

[rust.git] / compiler / rustc_trait_selection / src / traits / error_reporting / mod.rs

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index ef3d300020a39086edaa7cb0f0a2ee80c20f83ba..59d017545c0324329e651fc31b575eb1f71456b8 100644 (file)
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -4,13 +4,12 @@
 
 use super::{
     FulfillmentError, FulfillmentErrorCode, MismatchedProjectionTypes, Obligation, ObligationCause,
-    ObligationCauseCode, OutputTypeParameterMismatch, Overflow, PredicateObligation,
-    SelectionContext, SelectionError, TraitNotObjectSafe,
+    ObligationCauseCode, ObligationCtxt, OutputTypeParameterMismatch, Overflow,
+    PredicateObligation, SelectionContext, SelectionError, TraitNotObjectSafe,
 };
 use crate::infer::error_reporting::{TyCategory, TypeAnnotationNeeded as ErrorCode};
 use crate::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use crate::infer::{self, InferCtxt, TyCtxtInferExt};
-use crate::traits::engine::TraitEngineExt as _;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
 use crate::traits::query::normalize::AtExt as _;
 use crate::traits::specialize::to_pretty_impl_header;
@@ -30,7 +29,6 @@
 use rustc_hir::Node;
 use rustc_infer::infer::error_reporting::TypeErrCtxt;
 use rustc_infer::infer::TypeTrace;
-use rustc_infer::traits::TraitEngine;
 use rustc_middle::traits::select::OverflowError;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::ExpectedFound;
@@ -354,9 +352,9 @@ fn type_implements_fn_trait(
                     param_env,
                     ty.rebind(ty::TraitPredicate { trait_ref, constness, polarity }),
                 );
-                let mut fulfill_cx = <dyn TraitEngine<'tcx>>::new_in_snapshot(self.tcx);
-                fulfill_cx.register_predicate_obligation(self, obligation);
-                if fulfill_cx.select_all_or_error(self).is_empty() {
+                let ocx = ObligationCtxt::new_in_snapshot(self);
+                ocx.register_obligation(obligation);
+                if ocx.select_all_or_error().is_empty() {
                     return Ok((
                         ty::ClosureKind::from_def_id(self.tcx, trait_def_id)
                             .expect("expected to map DefId to ClosureKind"),
@@ -2546,7 +2544,10 @@ fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
             let obligation =
                 Obligation::new(self.tcx, ObligationCause::dummy(), param_env, cleaned_pred);
 
-            self.predicate_may_hold(&obligation)
+            // We don't use `InferCtxt::predicate_may_hold` because that
+            // will re-run predicates that overflow locally, which ends up
+            // taking a really long time to compute.
+            self.evaluate_obligation(&obligation).map_or(false, |eval| eval.may_apply())
         })
     }