Rollup merge of #106499 - lyming2007:issue-105946-fix, r=estebank

[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 8ec14526d1530aa0645c7fbeddb6a078b6bb5f26..1d39cf60e2616c61afeee225c167c1f6ebe0ecb6 100644 (file)
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -33,13 +33,14 @@
 use rustc_infer::infer::{InferOk, TypeTrace};
 use rustc_middle::traits::select::OverflowError;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
-use rustc_middle::ty::error::ExpectedFound;
+use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable};
 use rustc_middle::ty::print::{with_forced_trimmed_paths, FmtPrinter, Print};
 use rustc_middle::ty::{
     self, SubtypePredicate, ToPolyTraitRef, ToPredicate, TraitRef, Ty, TyCtxt, TypeFoldable,
     TypeVisitable,
 };
+use rustc_session::config::TraitSolver;
 use rustc_session::Limit;
 use rustc_span::def_id::LOCAL_CRATE;
 use rustc_span::symbol::sym;
@@ -1167,7 +1168,7 @@ fn report_selection_error(
                     }
 
                     ty::PredicateKind::WellFormed(ty) => {
-                        if !self.tcx.sess.opts.unstable_opts.chalk {
+                        if self.tcx.sess.opts.unstable_opts.trait_solver != TraitSolver::Chalk {
                             // WF predicates cannot themselves make
                             // errors. They can only block due to
                             // ambiguity; otherwise, they always
@@ -1215,6 +1216,25 @@ fn report_selection_error(
                 }
             }
 
+            OutputTypeParameterMismatch(
+                found_trait_ref,
+                expected_trait_ref,
+                terr @ TypeError::CyclicTy(_),
+            ) => {
+                let self_ty = found_trait_ref.self_ty().skip_binder();
+                let (cause, terr) = if let ty::Closure(def_id, _) = self_ty.kind() {
+                    (
+                        ObligationCause::dummy_with_span(tcx.def_span(def_id)),
+                        TypeError::CyclicTy(self_ty),
+                    )
+                } else {
+                    (obligation.cause.clone(), terr)
+                };
+                self.report_and_explain_type_error(
+                    TypeTrace::poly_trait_refs(&cause, true, expected_trait_ref, found_trait_ref),
+                    terr,
+                )
+            }
             OutputTypeParameterMismatch(found_trait_ref, expected_trait_ref, _) => {
                 let found_trait_ref = self.resolve_vars_if_possible(found_trait_ref);
                 let expected_trait_ref = self.resolve_vars_if_possible(expected_trait_ref);