OutputTypeParameterMismatch -> SignatureMismatch

compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs

@@ -362,9 +362,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         span: Span,
     ) -> bool {
         if let traits::FulfillmentErrorCode::SelectionError(
-            traits::SelectionError::OutputTypeParameterMismatch(
-                box traits::SelectionOutputTypeParameterMismatch { expected_trait_ref, .. },
-            ),
+            traits::SelectionError::SignatureMismatch(box traits::SignatureMismatchData {
+                expected_trait_ref,
+                ..
+            }),
         ) = error.code
             && let ty::Closure(def_id, _) | ty::Coroutine(def_id, ..) =
                 expected_trait_ref.skip_binder().self_ty().kind()

compiler/rustc_middle/src/traits/mod.rs

@@ -604,7 +604,7 @@ pub enum SelectionError<'tcx> {
     /// After a closure impl has selected, its "outputs" were evaluated
     /// (which for closures includes the "input" type params) and they
     /// didn't resolve. See `confirm_poly_trait_refs` for more.
-    OutputTypeParameterMismatch(Box<SelectionOutputTypeParameterMismatch<'tcx>>),
+    SignatureMismatch(Box<SignatureMismatchData<'tcx>>),
     /// The trait pointed by `DefId` is not object safe.
     TraitNotObjectSafe(DefId),
     /// A given constant couldn't be evaluated.
@@ -621,7 +621,7 @@ pub enum SelectionError<'tcx> {
 }
 
 #[derive(Clone, Debug, TypeVisitable)]
-pub struct SelectionOutputTypeParameterMismatch<'tcx> {
+pub struct SignatureMismatchData<'tcx> {
     pub found_trait_ref: ty::PolyTraitRef<'tcx>,
     pub expected_trait_ref: ty::PolyTraitRef<'tcx>,
     pub terr: ty::error::TypeError<'tcx>,

compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs

@@ -14,8 +14,8 @@ use crate::traits::specialize::to_pretty_impl_header;
 use crate::traits::NormalizeExt;
 use crate::traits::{
     elaborate, FulfillmentError, FulfillmentErrorCode, MismatchedProjectionTypes, Obligation,
-    ObligationCause, ObligationCauseCode, ObligationCtxt, OutputTypeParameterMismatch, Overflow,
-    PredicateObligation, SelectionError, TraitNotObjectSafe,
+    ObligationCause, ObligationCauseCode, ObligationCtxt, Overflow, PredicateObligation,
+    SelectionError, SignatureMismatch, TraitNotObjectSafe,
 };
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_errors::{
@@ -30,7 +30,7 @@ use rustc_hir::{GenericParam, Item, Node};
 use rustc_infer::infer::error_reporting::TypeErrCtxt;
 use rustc_infer::infer::{InferOk, TypeTrace};
 use rustc_middle::traits::select::OverflowError;
-use rustc_middle::traits::{DefiningAnchor, SelectionOutputTypeParameterMismatch};
+use rustc_middle::traits::{DefiningAnchor, SignatureMismatchData};
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::{BottomUpFolder, TypeFolder, TypeSuperFoldable};
@@ -891,22 +891,22 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 }
             }
 
-            OutputTypeParameterMismatch(box SelectionOutputTypeParameterMismatch {
+            SignatureMismatch(box SignatureMismatchData {
                 found_trait_ref,
                 expected_trait_ref,
                 terr: terr @ TypeError::CyclicTy(_),
-            }) => self.report_type_parameter_mismatch_cyclic_type_error(
+            }) => self.report_cyclic_signature_error(
                 &obligation,
                 found_trait_ref,
                 expected_trait_ref,
                 terr,
             ),
-            OutputTypeParameterMismatch(box SelectionOutputTypeParameterMismatch {
+            SignatureMismatch(box SignatureMismatchData {
                 found_trait_ref,
                 expected_trait_ref,
                 terr: _,
             }) => {
-                match self.report_type_parameter_mismatch_error(
+                match self.report_signature_mismatch_error(
                     &obligation,
                     span,
                     found_trait_ref,
@@ -1495,7 +1495,7 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
         kind: ty::ClosureKind,
     ) -> DiagnosticBuilder<'tcx>;
 
-    fn report_type_parameter_mismatch_cyclic_type_error(
+    fn report_cyclic_signature_error(
         &self,
         obligation: &PredicateObligation<'tcx>,
         found_trait_ref: ty::Binder<'tcx, ty::TraitRef<'tcx>>,
@@ -1509,7 +1509,7 @@ pub(super) trait InferCtxtPrivExt<'tcx> {
         def_id: DefId,
     ) -> DiagnosticBuilder<'tcx>;
 
-    fn report_type_parameter_mismatch_error(
+    fn report_signature_mismatch_error(
         &self,
         obligation: &PredicateObligation<'tcx>,
         span: Span,
@@ -3369,7 +3369,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         self.dcx().create_err(err)
     }
 
-    fn report_type_parameter_mismatch_cyclic_type_error(
+    fn report_cyclic_signature_error(
         &self,
         obligation: &PredicateObligation<'tcx>,
         found_trait_ref: ty::Binder<'tcx, ty::TraitRef<'tcx>>,
@@ -3430,7 +3430,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         err
     }
 
-    fn report_type_parameter_mismatch_error(
+    fn report_signature_mismatch_error(
         &self,
         obligation: &PredicateObligation<'tcx>,
         span: Span,
@@ -3449,10 +3449,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
         };
 
         let found_did = match *found_trait_ty.kind() {
-            ty::Closure(did, _) | ty::Foreign(did) | ty::FnDef(did, _) | ty::Coroutine(did, ..) => {
-                Some(did)
-            }
-            ty::Adt(def, _) => Some(def.did()),
+            ty::Closure(did, _) | ty::FnDef(did, _) | ty::Coroutine(did, ..) => Some(did),
             _ => None,
         };
 

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -11,7 +11,7 @@ use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::lang_items::LangItem;
 use rustc_infer::infer::BoundRegionConversionTime::HigherRankedType;
 use rustc_infer::infer::{DefineOpaqueTypes, InferOk};
-use rustc_middle::traits::{BuiltinImplSource, SelectionOutputTypeParameterMismatch};
+use rustc_middle::traits::{BuiltinImplSource, SignatureMismatchData};
 use rustc_middle::ty::{
     self, GenericArgs, GenericArgsRef, GenericParamDefKind, ToPolyTraitRef, ToPredicate,
     TraitPredicate, Ty, TyCtxt, TypeVisitableExt,
@@ -26,9 +26,9 @@ use crate::traits::vtable::{
 };
 use crate::traits::{
     BuiltinDerivedObligation, ImplDerivedObligation, ImplDerivedObligationCause, ImplSource,
-    ImplSourceUserDefinedData, Normalized, Obligation, ObligationCause,
-    OutputTypeParameterMismatch, PolyTraitObligation, PredicateObligation, Selection,
-    SelectionError, TraitNotObjectSafe, Unimplemented,
+    ImplSourceUserDefinedData, Normalized, Obligation, ObligationCause, PolyTraitObligation,
+    PredicateObligation, Selection, SelectionError, SignatureMismatch, TraitNotObjectSafe,
+    Unimplemented,
 };
 
 use super::BuiltinImplConditions;
@@ -922,7 +922,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 obligations
             })
             .map_err(|terr| {
-                OutputTypeParameterMismatch(Box::new(SelectionOutputTypeParameterMismatch {
+                SignatureMismatch(Box::new(SignatureMismatchData {
                     expected_trait_ref: obligation_trait_ref,
                     found_trait_ref: expected_trait_ref,
                     terr,