Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

36 files changed, 2831 insertions, 1851 deletions

diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index e25a9e903..b6f19d3cc 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -212,7 +212,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.can_coerce(arm_ty, ret_ty)
                     && prior_arm.map_or(true, |(_, ty, _)| self.can_coerce(ty, ret_ty))
                     // The match arms need to unify for the case of `impl Trait`.
-                    && !matches!(ret_ty.kind(), ty::Opaque(..))
+                    && !matches!(ret_ty.kind(), ty::Alias(ty::Opaque, ..))
             }
             _ => false,
         };
@@ -224,14 +224,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut ret_span: MultiSpan = semi_span.into();
         ret_span.push_span_label(
             expr.span,
-            "this could be implicitly returned but it is a statement, not a \
-                            tail expression",
+            "this could be implicitly returned but it is a statement, not a tail expression",
         );
         ret_span.push_span_label(ret, "the `match` arms can conform to this return type");
         ret_span.push_span_label(
             semi_span,
-            "the `match` is a statement because of this semicolon, consider \
-                            removing it",
+            "the `match` is a statement because of this semicolon, consider removing it",
         );
         diag.span_note(ret_span, "you might have meant to return the `match` expression");
         diag.tool_only_span_suggestion(
@@ -289,15 +287,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     fn maybe_get_coercion_reason(&self, hir_id: hir::HirId, sp: Span) -> Option<(Span, String)> {
         let node = {
-            let rslt = self.tcx.hir().get_parent_node(self.tcx.hir().get_parent_node(hir_id));
+            let rslt = self.tcx.hir().parent_id(self.tcx.hir().parent_id(hir_id));
             self.tcx.hir().get(rslt)
         };
         if let hir::Node::Block(block) = node {
             // check that the body's parent is an fn
-            let parent = self
-                .tcx
-                .hir()
-                .get(self.tcx.hir().get_parent_node(self.tcx.hir().get_parent_node(block.hir_id)));
+            let parent = self.tcx.hir().get_parent(self.tcx.hir().parent_id(block.hir_id));
             if let (Some(expr), hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(..), .. })) =
                 (&block.expr, parent)
             {
@@ -518,7 +513,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                 let substs = sig.output().walk().find_map(|arg| {
                     if let ty::GenericArgKind::Type(ty) = arg.unpack()
-                        && let ty::Opaque(def_id, substs) = *ty.kind()
+                        && let ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) = *ty.kind()
                         && def_id == rpit_def_id
                     {
                         Some(substs)
@@ -526,7 +521,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         None
                     }
                 })?;
-                let opaque_ty = self.tcx.mk_opaque(rpit_def_id, substs);
 
                 if !self.can_coerce(first_ty, expected) || !self.can_coerce(second_ty, expected) {
                     return None;
@@ -540,17 +534,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     {
                         let pred = pred.kind().rebind(match pred.kind().skip_binder() {
                             ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) => {
-                                assert_eq!(trait_pred.trait_ref.self_ty(), opaque_ty);
+                                // FIXME(rpitit): This will need to be fixed when we move to associated types
+                                assert!(matches!(
+                                    *trait_pred.trait_ref.self_ty().kind(),
+                                    ty::Alias(_, ty::AliasTy { def_id, substs, .. })
+                                    if def_id == rpit_def_id && substs == substs
+                                ));
                                 ty::PredicateKind::Clause(ty::Clause::Trait(
-                                    trait_pred.with_self_type(self.tcx, ty),
+                                    trait_pred.with_self_ty(self.tcx, ty),
                                 ))
                             }
                             ty::PredicateKind::Clause(ty::Clause::Projection(mut proj_pred)) => {
-                                assert_eq!(proj_pred.projection_ty.self_ty(), opaque_ty);
-                                proj_pred.projection_ty.substs = self.tcx.mk_substs_trait(
-                                    ty,
-                                    proj_pred.projection_ty.substs.iter().skip(1),
-                                );
+                                assert!(matches!(
+                                    *proj_pred.projection_ty.self_ty().kind(),
+                                    ty::Alias(_, ty::AliasTy { def_id, substs, .. })
+                                    if def_id == rpit_def_id && substs == substs
+                                ));
+                                proj_pred = proj_pred.with_self_ty(self.tcx, ty);
                                 ty::PredicateKind::Clause(ty::Clause::Projection(proj_pred))
                             }
                             _ => continue,
diff --git a/compiler/rustc_hir_typeck/src/autoderef.rs b/compiler/rustc_hir_typeck/src/autoderef.rs
index 41b52a4c4..7873257c4 100644
--- a/compiler/rustc_hir_typeck/src/autoderef.rs
+++ b/compiler/rustc_hir_typeck/src/autoderef.rs
@@ -2,11 +2,11 @@
 use super::method::MethodCallee;
 use super::{FnCtxt, PlaceOp};
 
+use rustc_hir_analysis::autoderef::{Autoderef, AutoderefKind};
 use rustc_infer::infer::InferOk;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, OverloadedDeref};
 use rustc_middle::ty::{self, Ty};
 use rustc_span::Span;
-use rustc_trait_selection::autoderef::{Autoderef, AutoderefKind};
 
 use std::iter;
 
diff --git a/compiler/rustc_hir_typeck/src/callee.rs b/compiler/rustc_hir_typeck/src/callee.rs
index b09ddf80e..b617821fb 100644
--- a/compiler/rustc_hir_typeck/src/callee.rs
+++ b/compiler/rustc_hir_typeck/src/callee.rs
@@ -1,13 +1,14 @@
-use super::method::probe::{IsSuggestion, Mode, ProbeScope};
+use super::method::probe::ProbeScope;
 use super::method::MethodCallee;
 use super::{Expectation, FnCtxt, TupleArgumentsFlag};
 
 use crate::type_error_struct;
 use rustc_ast::util::parser::PREC_POSTFIX;
-use rustc_errors::{struct_span_err, Applicability, Diagnostic, StashKey};
+use rustc_errors::{struct_span_err, Applicability, Diagnostic, ErrorGuaranteed, StashKey};
 use rustc_hir as hir;
 use rustc_hir::def::{self, CtorKind, Namespace, Res};
 use rustc_hir::def_id::DefId;
+use rustc_hir_analysis::autoderef::Autoderef;
 use rustc_infer::{
     infer,
     traits::{self, Obligation},
@@ -25,7 +26,6 @@ use rustc_span::def_id::LocalDefId;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
 use rustc_target::spec::abi;
-use rustc_trait_selection::autoderef::Autoderef;
 use rustc_trait_selection::infer::InferCtxtExt as _;
 use rustc_trait_selection::traits::error_reporting::DefIdOrName;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
@@ -241,7 +241,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             });
 
             if let Some(ok) = self.lookup_method_in_trait(
-                call_expr.span,
+                self.misc(call_expr.span),
                 method_name,
                 trait_def_id,
                 adjusted_ty,
@@ -288,7 +288,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         callee_span: Span,
     ) {
         let hir = self.tcx.hir();
-        let parent_hir_id = hir.get_parent_node(hir_id);
+        let parent_hir_id = hir.parent_id(hir_id);
         let parent_node = hir.get(parent_hir_id);
         if let (
             hir::Node::Expr(hir::Expr {
@@ -303,7 +303,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             {
                 // Actually need to unwrap a few more layers of HIR to get to
                 // the _real_ closure...
-                let async_closure = hir.get_parent_node(hir.get_parent_node(parent_hir_id));
+                let async_closure = hir.parent_id(hir.parent_id(parent_hir_id));
                 if let hir::Node::Expr(hir::Expr {
                     kind: hir::ExprKind::Closure(&hir::Closure { fn_decl_span, .. }),
                     ..
@@ -336,7 +336,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         call_expr: &'tcx hir::Expr<'tcx>,
         callee_expr: &'tcx hir::Expr<'tcx>,
     ) -> bool {
-        let hir_id = self.tcx.hir().get_parent_node(call_expr.hir_id);
+        let hir_id = self.tcx.hir().parent_id(call_expr.hir_id);
         let parent_node = self.tcx.hir().get(hir_id);
         if let (
             hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Array(_), .. }),
@@ -375,14 +375,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 if self.tcx.has_attr(def_id, sym::rustc_evaluate_where_clauses) {
                     let predicates = self.tcx.predicates_of(def_id);
                     let predicates = predicates.instantiate(self.tcx, subst);
-                    for (predicate, predicate_span) in
-                        predicates.predicates.iter().zip(&predicates.spans)
-                    {
+                    for (predicate, predicate_span) in predicates {
                         let obligation = Obligation::new(
                             self.tcx,
                             ObligationCause::dummy_with_span(callee_expr.span),
                             self.param_env,
-                            *predicate,
+                            predicate,
                         );
                         let result = self.evaluate_obligation(&obligation);
                         self.tcx
@@ -391,7 +389,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 callee_expr.span,
                                 &format!("evaluate({:?}) = {:?}", predicate, result),
                             )
-                            .span_label(*predicate_span, "predicate")
+                            .span_label(predicate_span, "predicate")
                             .emit();
                     }
                 }
@@ -399,6 +397,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             ty::FnPtr(sig) => (sig, None),
             _ => {
+                for arg in arg_exprs {
+                    self.check_expr(arg);
+                }
+
                 if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = &callee_expr.kind
                     && let [segment] = path.segments
                     && let Some(mut diag) = self
@@ -424,21 +426,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                 }
 
-                self.report_invalid_callee(call_expr, callee_expr, callee_ty, arg_exprs);
-
-                // This is the "default" function signature, used in case of error.
-                // In that case, we check each argument against "error" in order to
-                // set up all the node type bindings.
-                (
-                    ty::Binder::dummy(self.tcx.mk_fn_sig(
-                        self.err_args(arg_exprs.len()).into_iter(),
-                        self.tcx.ty_error(),
-                        false,
-                        hir::Unsafety::Normal,
-                        abi::Abi::Rust,
-                    )),
-                    None,
-                )
+                let err = self.report_invalid_callee(call_expr, callee_expr, callee_ty, arg_exprs);
+
+                return self.tcx.ty_error_with_guaranteed(err);
             }
         };
 
@@ -498,20 +488,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expected: Expectation<'tcx>,
     ) -> Option<Ty<'tcx>> {
         if let [callee_expr, rest @ ..] = arg_exprs {
-            let callee_ty = self.check_expr(callee_expr);
+            let callee_ty = self.typeck_results.borrow().expr_ty_adjusted_opt(callee_expr)?;
+
             // First, do a probe with `IsSuggestion(true)` to avoid emitting
             // any strange errors. If it's successful, then we'll do a true
             // method lookup.
             let Ok(pick) = self
-            .probe_for_name(
-                Mode::MethodCall,
+            .lookup_probe_for_diagnostic(
                 segment.ident,
-                IsSuggestion(true),
                 callee_ty,
-                call_expr.hir_id,
+                call_expr,
                 // We didn't record the in scope traits during late resolution
                 // so we need to probe AllTraits unfortunately
                 ProbeScope::AllTraits,
+                expected.only_has_type(self),
             ) else {
                 return None;
             };
@@ -521,7 +511,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 callee_expr,
                 call_expr,
                 callee_ty,
-                pick,
+                &pick,
                 segment,
             );
             if pick.illegal_sized_bound.is_some() {
@@ -591,7 +581,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         callee_expr: &'tcx hir::Expr<'tcx>,
         callee_ty: Ty<'tcx>,
         arg_exprs: &'tcx [hir::Expr<'tcx>],
-    ) {
+    ) -> ErrorGuaranteed {
         let mut unit_variant = None;
         if let hir::ExprKind::Path(qpath) = &callee_expr.kind
             && let Res::Def(def::DefKind::Ctor(kind, CtorKind::Const), _)
@@ -667,8 +657,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
 
         if !self.maybe_suggest_bad_array_definition(&mut err, call_expr, callee_expr) {
-            if let Some((maybe_def, output_ty, _)) =
-                self.extract_callable_info(callee_expr, callee_ty)
+            if let Some((maybe_def, output_ty, _)) = self.extract_callable_info(callee_ty)
                 && !self.type_is_sized_modulo_regions(self.param_env, output_ty, callee_expr.span)
             {
                 let descr = match maybe_def {
@@ -720,7 +709,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 err.span_label(span, label);
             }
         }
-        err.emit();
+        err.emit()
     }
 
     fn confirm_deferred_closure_call(
diff --git a/compiler/rustc_hir_typeck/src/cast.rs b/compiler/rustc_hir_typeck/src/cast.rs
index 890a068a7..712f9b87a 100644
--- a/compiler/rustc_hir_typeck/src/cast.rs
+++ b/compiler/rustc_hir_typeck/src/cast.rs
@@ -31,14 +31,16 @@
 use super::FnCtxt;
 
 use crate::type_error_struct;
-use rustc_errors::{struct_span_err, Applicability, DelayDm, DiagnosticBuilder, ErrorGuaranteed};
+use hir::ExprKind;
+use rustc_errors::{
+    struct_span_err, Applicability, DelayDm, Diagnostic, DiagnosticBuilder, ErrorGuaranteed,
+};
 use rustc_hir as hir;
 use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::mir::Mutability;
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::cast::{CastKind, CastTy};
 use rustc_middle::ty::error::TypeError;
-use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, Ty, TypeAndMut, TypeVisitable, VariantDef};
 use rustc_session::lint;
 use rustc_session::Session;
@@ -75,10 +77,8 @@ enum PointerKind<'tcx> {
     VTable(Option<DefId>),
     /// Slice
     Length,
-    /// The unsize info of this projection
-    OfProjection(ty::ProjectionTy<'tcx>),
-    /// The unsize info of this opaque ty
-    OfOpaque(DefId, SubstsRef<'tcx>),
+    /// The unsize info of this projection or opaque type
+    OfAlias(ty::AliasTy<'tcx>),
     /// The unsize info of this parameter
     OfParam(ty::ParamTy),
 }
@@ -118,8 +118,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Pointers to foreign types are thin, despite being unsized
             ty::Foreign(..) => Some(PointerKind::Thin),
             // We should really try to normalize here.
-            ty::Projection(pi) => Some(PointerKind::OfProjection(pi)),
-            ty::Opaque(def_id, substs) => Some(PointerKind::OfOpaque(def_id, substs)),
+            ty::Alias(_, pi) => Some(PointerKind::OfAlias(pi)),
             ty::Param(p) => Some(PointerKind::OfParam(p)),
             // Insufficient type information.
             ty::Placeholder(..) | ty::Bound(..) | ty::Infer(_) => None,
@@ -153,7 +152,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
 #[derive(Copy, Clone)]
 pub enum CastError {
-    ErrorGuaranteed,
+    ErrorGuaranteed(ErrorGuaranteed),
 
     CastToBool,
     CastToChar,
@@ -178,8 +177,8 @@ pub enum CastError {
 }
 
 impl From<ErrorGuaranteed> for CastError {
-    fn from(_: ErrorGuaranteed) -> Self {
-        CastError::ErrorGuaranteed
+    fn from(err: ErrorGuaranteed) -> Self {
+        CastError::ErrorGuaranteed(err)
     }
 }
 
@@ -227,11 +226,10 @@ impl<'a, 'tcx> CastCheck<'tcx> {
 
     fn report_cast_error(&self, fcx: &FnCtxt<'a, 'tcx>, e: CastError) {
         match e {
-            CastError::ErrorGuaranteed => {
+            CastError::ErrorGuaranteed(_) => {
                 // an error has already been reported
             }
             CastError::NeedDeref => {
-                let error_span = self.span;
                 let mut err = make_invalid_casting_error(
                     fcx.tcx.sess,
                     self.span,
@@ -239,21 +237,25 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                     self.cast_ty,
                     fcx,
                 );
-                let cast_ty = fcx.ty_to_string(self.cast_ty);
-                err.span_label(
-                    error_span,
-                    format!("cannot cast `{}` as `{}`", fcx.ty_to_string(self.expr_ty), cast_ty),
-                );
-                if let Ok(snippet) = fcx.sess().source_map().span_to_snippet(self.expr_span) {
-                    err.span_suggestion(
-                        self.expr_span,
-                        "dereference the expression",
-                        format!("*{}", snippet),
-                        Applicability::MaybeIncorrect,
+
+                if matches!(self.expr.kind, ExprKind::AddrOf(..)) {
+                    // get just the borrow part of the expression
+                    let span = self.expr_span.with_hi(self.expr.peel_borrows().span.lo());
+                    err.span_suggestion_verbose(
+                        span,
+                        "remove the unneeded borrow",
+                        "",
+                        Applicability::MachineApplicable,
                     );
                 } else {
-                    err.span_help(self.expr_span, "dereference the expression with `*`");
+                    err.span_suggestion_verbose(
+                        self.expr_span.shrink_to_lo(),
+                        "dereference the expression",
+                        "*",
+                        Applicability::MachineApplicable,
+                    );
                 }
+
                 err.emit();
             }
             CastError::NeedViaThinPtr | CastError::NeedViaPtr => {
@@ -274,6 +276,9 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                         }
                     ));
                 }
+
+                self.try_suggest_collection_to_bool(fcx, &mut err);
+
                 err.emit();
             }
             CastError::NeedViaInt => {
@@ -521,6 +526,9 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                 } else {
                     err.span_label(self.span, "invalid cast");
                 }
+
+                self.try_suggest_collection_to_bool(fcx, &mut err);
+
                 err.emit();
             }
             CastError::SizedUnsizedCast => {
@@ -851,13 +859,15 @@ impl<'a, 'tcx> CastCheck<'tcx> {
 
             (Int(_) | Float, Int(_) | Float) => Ok(CastKind::NumericCast),
 
-            (_, DynStar) | (DynStar, _) => {
+            (_, DynStar) => {
                 if fcx.tcx.features().dyn_star {
                     bug!("should be handled by `try_coerce`")
                 } else {
                     Err(CastError::IllegalCast)
                 }
             }
+
+            (DynStar, _) => Err(CastError::IllegalCast),
         }
     }
 
@@ -976,11 +986,9 @@ impl<'a, 'tcx> CastCheck<'tcx> {
             Some(PointerKind::Thin) => Ok(CastKind::AddrPtrCast),
             Some(PointerKind::VTable(_)) => Err(CastError::IntToFatCast(Some("a vtable"))),
             Some(PointerKind::Length) => Err(CastError::IntToFatCast(Some("a length"))),
-            Some(
-                PointerKind::OfProjection(_)
-                | PointerKind::OfOpaque(_, _)
-                | PointerKind::OfParam(_),
-            ) => Err(CastError::IntToFatCast(None)),
+            Some(PointerKind::OfAlias(_) | PointerKind::OfParam(_)) => {
+                Err(CastError::IntToFatCast(None))
+            }
         }
     }
 
@@ -1084,4 +1092,40 @@ impl<'a, 'tcx> CastCheck<'tcx> {
             },
         );
     }
+
+    /// Attempt to suggest using `.is_empty` when trying to cast from a
+    /// collection type to a boolean.
+    fn try_suggest_collection_to_bool(&self, fcx: &FnCtxt<'a, 'tcx>, err: &mut Diagnostic) {
+        if self.cast_ty.is_bool() {
+            let derefed = fcx
+                .autoderef(self.expr_span, self.expr_ty)
+                .silence_errors()
+                .find(|t| matches!(t.0.kind(), ty::Str | ty::Slice(..)));
+
+            if let Some((deref_ty, _)) = derefed {
+                // Give a note about what the expr derefs to.
+                if deref_ty != self.expr_ty.peel_refs() {
+                    err.span_note(
+                        self.expr_span,
+                        format!(
+                            "this expression `Deref`s to `{}` which implements `is_empty`",
+                            fcx.ty_to_string(deref_ty)
+                        ),
+                    );
+                }
+
+                // Create a multipart suggestion: add `!` and `.is_empty()` in
+                // place of the cast.
+                let suggestion = vec![
+                    (self.expr_span.shrink_to_lo(), "!".to_string()),
+                    (self.span.with_lo(self.expr_span.hi()), ".is_empty()".to_string()),
+                ];
+
+                err.multipart_suggestion_verbose(format!(
+                    "consider using the `is_empty` method on `{}` to determine if it contains anything",
+                    fcx.ty_to_string(self.expr_ty),
+                ),  suggestion, Applicability::MaybeIncorrect);
+            }
+        }
+    }
 }
diff --git a/compiler/rustc_hir_typeck/src/check.rs b/compiler/rustc_hir_typeck/src/check.rs
index 32f86b804..57feefbca 100644
--- a/compiler/rustc_hir_typeck/src/check.rs
+++ b/compiler/rustc_hir_typeck/src/check.rs
@@ -1,4 +1,7 @@
 use crate::coercion::CoerceMany;
+use crate::errors::{
+    LangStartIncorrectNumberArgs, LangStartIncorrectParam, LangStartIncorrectRetTy,
+};
 use crate::gather_locals::GatherLocalsVisitor;
 use crate::FnCtxt;
 use crate::GeneratorTypes;
@@ -9,8 +12,9 @@ use rustc_hir::lang_items::LangItem;
 use rustc_hir_analysis::check::fn_maybe_err;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::RegionVariableOrigin;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, Binder, Ty, TyCtxt};
 use rustc_span::def_id::LocalDefId;
+use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
 use std::cell::RefCell;
 
@@ -168,6 +172,10 @@ pub(super) fn check_fn<'a, 'tcx>(
         check_panic_info_fn(tcx, panic_impl_did.expect_local(), fn_sig, decl, declared_ret_ty);
     }
 
+    if let Some(lang_start_defid) = tcx.lang_items().start_fn() && lang_start_defid == hir.local_def_id(fn_id).to_def_id() {
+        check_lang_start_fn(tcx, fn_sig, decl, fn_def_id);
+    }
+
     gen_ty
 }
 
@@ -223,3 +231,126 @@ fn check_panic_info_fn(
         tcx.sess.span_err(span, "should have no const parameters");
     }
 }
+
+fn check_lang_start_fn<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    fn_sig: ty::FnSig<'tcx>,
+    decl: &'tcx hir::FnDecl<'tcx>,
+    def_id: LocalDefId,
+) {
+    let inputs = fn_sig.inputs();
+
+    let arg_count = inputs.len();
+    if arg_count != 4 {
+        tcx.sess.emit_err(LangStartIncorrectNumberArgs {
+            params_span: tcx.def_span(def_id),
+            found_param_count: arg_count,
+        });
+    }
+
+    // only check args if they should exist by checking the count
+    // note: this does not handle args being shifted or their order swapped very nicely
+    // but it's a lang item, users shouldn't frequently encounter this
+
+    // first arg is `main: fn() -> T`
+    if let Some(&main_arg) = inputs.get(0) {
+        // make a Ty for the generic on the fn for diagnostics
+        // FIXME: make the lang item generic checks check for the right generic *kind*
+        // for example `start`'s generic should be a type parameter
+        let generics = tcx.generics_of(def_id);
+        let fn_generic = generics.param_at(0, tcx);
+        let generic_tykind =
+            ty::Param(ty::ParamTy { index: fn_generic.index, name: fn_generic.name });
+        let generic_ty = tcx.mk_ty(generic_tykind);
+        let expected_fn_sig =
+            tcx.mk_fn_sig([].iter(), &generic_ty, false, hir::Unsafety::Normal, Abi::Rust);
+        let expected_ty = tcx.mk_fn_ptr(Binder::dummy(expected_fn_sig));
+
+        // we emit the same error to suggest changing the arg no matter what's wrong with the arg
+        let emit_main_fn_arg_err = || {
+            tcx.sess.emit_err(LangStartIncorrectParam {
+                param_span: decl.inputs[0].span,
+                param_num: 1,
+                expected_ty: expected_ty,
+                found_ty: main_arg,
+            });
+        };
+
+        if let ty::FnPtr(main_fn_sig) = main_arg.kind() {
+            let main_fn_inputs = main_fn_sig.inputs();
+            if main_fn_inputs.iter().count() != 0 {
+                emit_main_fn_arg_err();
+            }
+
+            let output = main_fn_sig.output();
+            output.map_bound(|ret_ty| {
+                // if the output ty is a generic, it's probably the right one
+                if !matches!(ret_ty.kind(), ty::Param(_)) {
+                    emit_main_fn_arg_err();
+                }
+            });
+        } else {
+            emit_main_fn_arg_err();
+        }
+    }
+
+    // second arg is isize
+    if let Some(&argc_arg) = inputs.get(1) {
+        if argc_arg != tcx.types.isize {
+            tcx.sess.emit_err(LangStartIncorrectParam {
+                param_span: decl.inputs[1].span,
+                param_num: 2,
+                expected_ty: tcx.types.isize,
+                found_ty: argc_arg,
+            });
+        }
+    }
+
+    // third arg is `*const *const u8`
+    if let Some(&argv_arg) = inputs.get(2) {
+        let mut argv_is_okay = false;
+        if let ty::RawPtr(outer_ptr) = argv_arg.kind() {
+            if outer_ptr.mutbl.is_not() {
+                if let ty::RawPtr(inner_ptr) = outer_ptr.ty.kind() {
+                    if inner_ptr.mutbl.is_not() && inner_ptr.ty == tcx.types.u8 {
+                        argv_is_okay = true;
+                    }
+                }
+            }
+        }
+
+        if !argv_is_okay {
+            let inner_ptr_ty =
+                tcx.mk_ptr(ty::TypeAndMut { mutbl: hir::Mutability::Not, ty: tcx.types.u8 });
+            let expected_ty =
+                tcx.mk_ptr(ty::TypeAndMut { mutbl: hir::Mutability::Not, ty: inner_ptr_ty });
+            tcx.sess.emit_err(LangStartIncorrectParam {
+                param_span: decl.inputs[2].span,
+                param_num: 3,
+                expected_ty,
+                found_ty: argv_arg,
+            });
+        }
+    }
+
+    // fourth arg is `sigpipe: u8`
+    if let Some(&sigpipe_arg) = inputs.get(3) {
+        if sigpipe_arg != tcx.types.u8 {
+            tcx.sess.emit_err(LangStartIncorrectParam {
+                param_span: decl.inputs[3].span,
+                param_num: 4,
+                expected_ty: tcx.types.u8,
+                found_ty: sigpipe_arg,
+            });
+        }
+    }
+
+    // output type is isize
+    if fn_sig.output() != tcx.types.isize {
+        tcx.sess.emit_err(LangStartIncorrectRetTy {
+            ret_span: decl.output.span(),
+            expected_ty: tcx.types.isize,
+            found_ty: fn_sig.output(),
+        });
+    }
+}
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index 429cb60ba..12a2abfa7 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -13,7 +13,7 @@ use rustc_infer::infer::{InferOk, InferResult};
 use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::ty::subst::InternalSubsts;
 use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, Ty};
+use rustc_middle::ty::{self, Ty, TypeSuperVisitable, TypeVisitor};
 use rustc_span::source_map::Span;
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits;
@@ -21,6 +21,7 @@ use rustc_trait_selection::traits::error_reporting::ArgKind;
 use rustc_trait_selection::traits::error_reporting::InferCtxtExt as _;
 use std::cmp;
 use std::iter;
+use std::ops::ControlFlow;
 
 /// What signature do we *expect* the closure to have from context?
 #[derive(Debug, Clone, TypeFoldable, TypeVisitable)]
@@ -54,7 +55,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // closure sooner rather than later, so first examine the expected
         // type, and see if can glean a closure kind from there.
         let (expected_sig, expected_kind) = match expected.to_option(self) {
-            Some(ty) => self.deduce_expectations_from_expected_type(ty),
+            Some(ty) => self.deduce_closure_signature(ty),
             None => (None, None),
         };
         let body = self.tcx.hir().body(closure.body);
@@ -162,14 +163,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Given the expected type, figures out what it can about this closure we
     /// are about to type check:
     #[instrument(skip(self), level = "debug")]
-    fn deduce_expectations_from_expected_type(
+    fn deduce_closure_signature(
         &self,
         expected_ty: Ty<'tcx>,
     ) -> (Option<ExpectedSig<'tcx>>, Option<ty::ClosureKind>) {
         match *expected_ty.kind() {
-            ty::Opaque(def_id, substs) => self.deduce_signature_from_predicates(
-                self.tcx.bound_explicit_item_bounds(def_id).subst_iter_copied(self.tcx, substs),
-            ),
+            ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => self
+                .deduce_closure_signature_from_predicates(
+                    expected_ty,
+                    self.tcx.bound_explicit_item_bounds(def_id).subst_iter_copied(self.tcx, substs),
+                ),
             ty::Dynamic(ref object_type, ..) => {
                 let sig = object_type.projection_bounds().find_map(|pb| {
                     let pb = pb.with_self_ty(self.tcx, self.tcx.types.trait_object_dummy_self);
@@ -180,7 +183,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     .and_then(|did| self.tcx.fn_trait_kind_from_def_id(did));
                 (sig, kind)
             }
-            ty::Infer(ty::TyVar(vid)) => self.deduce_signature_from_predicates(
+            ty::Infer(ty::TyVar(vid)) => self.deduce_closure_signature_from_predicates(
+                self.tcx.mk_ty_var(self.root_var(vid)),
                 self.obligations_for_self_ty(vid).map(|obl| (obl.predicate, obl.cause.span)),
             ),
             ty::FnPtr(sig) => {
@@ -191,8 +195,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    fn deduce_signature_from_predicates(
+    fn deduce_closure_signature_from_predicates(
         &self,
+        expected_ty: Ty<'tcx>,
         predicates: impl DoubleEndedIterator<Item = (ty::Predicate<'tcx>, Span)>,
     ) -> (Option<ExpectedSig<'tcx>>, Option<ty::ClosureKind>) {
         let mut expected_sig = None;
@@ -213,13 +218,33 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             if expected_sig.is_none()
                 && let ty::PredicateKind::Clause(ty::Clause::Projection(proj_predicate)) = bound_predicate.skip_binder()
             {
-                expected_sig = self.normalize(
+                let inferred_sig = self.normalize(
                     obligation.cause.span,
                     self.deduce_sig_from_projection(
                     Some(obligation.cause.span),
                         bound_predicate.rebind(proj_predicate),
                     ),
                 );
+                // Make sure that we didn't infer a signature that mentions itself.
+                // This can happen when we elaborate certain supertrait bounds that
+                // mention projections containing the `Self` type. See #105401.
+                struct MentionsTy<'tcx> {
+                    expected_ty: Ty<'tcx>,
+                }
+                impl<'tcx> TypeVisitor<'tcx> for MentionsTy<'tcx> {
+                    type BreakTy = ();
+
+                    fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
+                        if t == self.expected_ty {
+                            ControlFlow::Break(())
+                        } else {
+                            t.super_visit_with(self)
+                        }
+                    }
+                }
+                if inferred_sig.visit_with(&mut MentionsTy { expected_ty }).is_continue() {
+                    expected_sig = inferred_sig;
+                }
             }
 
             // Even if we can't infer the full signature, we may be able to
@@ -425,7 +450,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // `deduce_expectations_from_expected_type` introduces
         // late-bound lifetimes defined elsewhere, which we now
         // anonymize away, so as not to confuse the user.
-        let bound_sig = self.tcx.anonymize_late_bound_regions(bound_sig);
+        let bound_sig = self.tcx.anonymize_bound_vars(bound_sig);
 
         let closure_sigs = self.closure_sigs(expr_def_id, body, bound_sig);
 
@@ -499,7 +524,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // FIXME(#45727): As discussed in [this comment][c1], naively
         // forcing equality here actually results in suboptimal error
-        // messages in some cases.  For now, if there would have been
+        // messages in some cases. For now, if there would have been
         // an obvious error, we fallback to declaring the type of the
         // closure to be the one the user gave, which allows other
         // error message code to trigger.
@@ -622,14 +647,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ),
             bound_vars,
         );
-        // Astconv can't normalize inputs or outputs with escaping bound vars,
-        // so normalize them here, after we've wrapped them in a binder.
-        let result = self.normalize(self.tcx.hir().span(hir_id), result);
 
         let c_result = self.inh.infcx.canonicalize_response(result);
         self.typeck_results.borrow_mut().user_provided_sigs.insert(expr_def_id, c_result);
 
-        result
+        // Normalize only after registering in `user_provided_sigs`.
+        self.normalize(self.tcx.hir().span(hir_id), result)
     }
 
     /// Invoked when we are translating the generator that results
@@ -677,17 +700,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     get_future_output(obligation.predicate, obligation.cause.span)
                 })?
             }
-            ty::Opaque(def_id, substs) => self
+            ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => self
                 .tcx
                 .bound_explicit_item_bounds(def_id)
                 .subst_iter_copied(self.tcx, substs)
                 .find_map(|(p, s)| get_future_output(p, s))?,
             ty::Error(_) => return None,
-            ty::Projection(proj)
-                if self.tcx.def_kind(proj.item_def_id) == DefKind::ImplTraitPlaceholder =>
+            ty::Alias(ty::Projection, proj)
+                if self.tcx.def_kind(proj.def_id) == DefKind::ImplTraitPlaceholder =>
             {
                 self.tcx
-                    .bound_explicit_item_bounds(proj.item_def_id)
+                    .bound_explicit_item_bounds(proj.def_id)
                     .subst_iter_copied(self.tcx, proj.substs)
                     .find_map(|(p, s)| get_future_output(p, s))?
             }
@@ -743,11 +766,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // The `Future` trait has only one associated item, `Output`,
         // so check that this is what we see.
         let output_assoc_item = self.tcx.associated_item_def_ids(future_trait)[0];
-        if output_assoc_item != predicate.projection_ty.item_def_id {
+        if output_assoc_item != predicate.projection_ty.def_id {
             span_bug!(
                 cause_span,
                 "projecting associated item `{:?}` from future, which is not Output `{:?}`",
-                predicate.projection_ty.item_def_id,
+                predicate.projection_ty.def_id,
                 output_assoc_item,
             );
         }
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index f0b349f0c..bbf7b81a2 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -13,7 +13,7 @@
 //! useful for freezing mut things (that is, when the expected type is &T
 //! but you have &mut T) and also for avoiding the linearity
 //! of mut things (when the expected is &mut T and you have &mut T). See
-//! the various `src/test/ui/coerce/*.rs` tests for
+//! the various `tests/ui/coerce/*.rs` tests for
 //! examples of where this is useful.
 //!
 //! ## Subtle note
@@ -118,7 +118,7 @@ fn identity(_: Ty<'_>) -> Vec<Adjustment<'_>> {
     vec![]
 }
 
-fn simple<'tcx>(kind: Adjust<'tcx>) -> impl FnOnce(Ty<'tcx>) -> Vec<Adjustment<'tcx>> {
+fn simple<'tcx>(kind: Adjust<'tcx>) -> impl FnOnce(Ty<'tcx>) -> Vec<Adjustment<'_>> {
     move |target| vec![Adjustment { kind, target }]
 }
 
@@ -171,6 +171,10 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
 
         // Just ignore error types.
         if a.references_error() || b.references_error() {
+            // Best-effort try to unify these types -- we're already on the error path,
+            // so this will have the side-effect of making sure we have no ambiguities
+            // due to `[type error]` and `_` not coercing together.
+            let _ = self.commit_if_ok(|_| self.at(&self.cause, self.param_env).eq(a, b));
             return success(vec![], self.fcx.tcx.ty_error(), vec![]);
         }
 
@@ -309,7 +313,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
 
         // If we have a parameter of type `&M T_a` and the value
         // provided is `expr`, we will be adding an implicit borrow,
-        // meaning that we convert `f(expr)` to `f(&M *expr)`.  Therefore,
+        // meaning that we convert `f(expr)` to `f(&M *expr)`. Therefore,
         // to type check, we will construct the type that `&M*expr` would
         // yield.
 
@@ -336,7 +340,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
                 continue;
             }
 
-            // At this point, we have deref'd `a` to `referent_ty`.  So
+            // At this point, we have deref'd `a` to `referent_ty`. So
             // imagine we are coercing from `&'a mut Vec<T>` to `&'b mut [T]`.
             // In the autoderef loop for `&'a mut Vec<T>`, we would get
             // three callbacks:
@@ -367,7 +371,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             // - if in sub mode, that means we want to use `'b` (the
             //   region from the target reference) for both
             //   pointers [2]. This is because sub mode (somewhat
-            //   arbitrarily) returns the subtype region.  In the case
+            //   arbitrarily) returns the subtype region. In the case
             //   where we are coercing to a target type, we know we
             //   want to use that target type region (`'b`) because --
             //   for the program to type-check -- it must be the
@@ -379,7 +383,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             //     annotate the region of a borrow), and regionck has
             //     code that adds edges from the region of a borrow
             //     (`'b`, here) into the regions in the borrowed
-            //     expression (`*x`, here).  (Search for "link".)
+            //     expression (`*x`, here). (Search for "link".)
             // - if in lub mode, things can get fairly complicated. The
             //   easiest thing is just to make a fresh
             //   region variable [4], which effectively means we defer
@@ -453,7 +457,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         if ty == a && mt_a.mutbl.is_not() && autoderef.step_count() == 1 {
             // As a special case, if we would produce `&'a *x`, that's
             // a total no-op. We end up with the type `&'a T` just as
-            // we started with.  In that case, just skip it
+            // we started with. In that case, just skip it
             // altogether. This is just an optimization.
             //
             // Note that for `&mut`, we DO want to reborrow --
@@ -1472,7 +1476,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
             //     if let Some(x) = ... { }
             //
             // we wind up with a second match arm that is like `_ =>
-            // ()`.  That is the case we are considering here. We take
+            // ()`. That is the case we are considering here. We take
             // a different path to get the right "expected, found"
             // message and so forth (and because we know that
             // `expression_ty` will be unit).
@@ -1543,12 +1547,12 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                         err.span_label(cause.span, "return type is not `()`");
                     }
                     ObligationCauseCode::BlockTailExpression(blk_id) => {
-                        let parent_id = fcx.tcx.hir().get_parent_node(blk_id);
+                        let parent_id = fcx.tcx.hir().parent_id(blk_id);
                         err = self.report_return_mismatched_types(
                             cause,
                             expected,
                             found,
-                            coercion_error.clone(),
+                            coercion_error,
                             fcx,
                             parent_id,
                             expression,
@@ -1567,14 +1571,14 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                             cause,
                             expected,
                             found,
-                            coercion_error.clone(),
+                            coercion_error,
                             fcx,
                             id,
                             expression,
                             None,
                         );
                         if !fcx.tcx.features().unsized_locals {
-                            let id = fcx.tcx.hir().get_parent_node(id);
+                            let id = fcx.tcx.hir().parent_id(id);
                             unsized_return = self.is_return_ty_unsized(fcx, id);
                         }
                     }
@@ -1583,7 +1587,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                             cause,
                             expected,
                             found,
-                            coercion_error.clone(),
+                            coercion_error,
                         );
                     }
                 }
@@ -1664,7 +1668,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
         let mut pointing_at_return_type = false;
         let mut fn_output = None;
 
-        let parent_id = fcx.tcx.hir().get_parent_node(id);
+        let parent_id = fcx.tcx.hir().parent_id(id);
         let parent = fcx.tcx.hir().get(parent_id);
         if let Some(expr) = expression
             && let hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Closure(&hir::Closure { body, .. }), .. }) = parent
@@ -1803,9 +1807,9 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
             // Get the return type.
             && let hir::TyKind::OpaqueDef(..) = ty.kind
         {
-            let ty = <dyn AstConv<'_>>::ast_ty_to_ty(fcx, ty);
+            let ty = fcx.astconv().ast_ty_to_ty( ty);
             // Get the `impl Trait`'s `DefId`.
-            if let ty::Opaque(def_id, _) = ty.kind()
+            if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = ty.kind()
                 // Get the `impl Trait`'s `Item` so that we can get its trait bounds and
                 // get the `Trait`'s `DefId`.
                 && let hir::ItemKind::OpaqueTy(hir::OpaqueTy { bounds, .. }) =
@@ -1862,7 +1866,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
     fn is_return_ty_unsized<'a>(&self, fcx: &FnCtxt<'a, 'tcx>, blk_id: hir::HirId) -> bool {
         if let Some((fn_decl, _)) = fcx.get_fn_decl(blk_id)
             && let hir::FnRetTy::Return(ty) = fn_decl.output
-            && let ty = <dyn AstConv<'_>>::ast_ty_to_ty(fcx, ty)
+            && let ty = fcx.astconv().ast_ty_to_ty( ty)
             && let ty::Dynamic(..) = ty.kind()
         {
             return true;
diff --git a/compiler/rustc_hir_typeck/src/demand.rs b/compiler/rustc_hir_typeck/src/demand.rs
index 24184bdbf..f4c4d4310 100644
--- a/compiler/rustc_hir_typeck/src/demand.rs
+++ b/compiler/rustc_hir_typeck/src/demand.rs
@@ -1,5 +1,6 @@
 use crate::FnCtxt;
 use rustc_ast::util::parser::PREC_POSTFIX;
+use rustc_errors::MultiSpan;
 use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_hir as hir;
 use rustc_hir::def::CtorKind;
@@ -23,7 +24,7 @@ use std::cmp::min;
 use std::iter;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
-    pub fn emit_coerce_suggestions(
+    pub fn emit_type_mismatch_suggestions(
         &self,
         err: &mut Diagnostic,
         expr: &hir::Expr<'tcx>,
@@ -36,11 +37,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return;
         }
 
-        self.annotate_expected_due_to_let_ty(err, expr, error);
+        self.annotate_alternative_method_deref(err, expr, error);
 
         // Use `||` to give these suggestions a precedence
         let _ = self.suggest_missing_parentheses(err, expr)
+            || self.suggest_remove_last_method_call(err, expr, expected)
+            || self.suggest_associated_const(err, expr, expected)
             || self.suggest_deref_ref_or_into(err, expr, expected, expr_ty, expected_ty_expr)
+            || self.suggest_option_to_bool(err, expr, expr_ty, expected)
             || self.suggest_compatible_variants(err, expr, expected, expr_ty)
             || self.suggest_non_zero_new_unwrap(err, expr, expected, expr_ty)
             || self.suggest_calling_boxed_future_when_appropriate(err, expr, expected, expr_ty)
@@ -48,13 +52,32 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             || self.suggest_boxing_when_appropriate(err, expr, expected, expr_ty)
             || self.suggest_block_to_brackets_peeling_refs(err, expr, expr_ty, expected)
             || self.suggest_copied_or_cloned(err, expr, expr_ty, expected)
+            || self.suggest_clone_for_ref(err, expr, expr_ty, expected)
             || self.suggest_into(err, expr, expr_ty, expected)
-            || self.suggest_option_to_bool(err, expr, expr_ty, expected)
             || self.suggest_floating_point_literal(err, expr, expected);
+    }
 
+    pub fn emit_coerce_suggestions(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'tcx>,
+        expr_ty: Ty<'tcx>,
+        expected: Ty<'tcx>,
+        expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>,
+        error: Option<TypeError<'tcx>>,
+    ) {
+        if expr_ty == expected {
+            return;
+        }
+
+        self.annotate_expected_due_to_let_ty(err, expr, error);
+        self.emit_type_mismatch_suggestions(err, expr, expr_ty, expected, expected_ty_expr, error);
         self.note_type_is_not_clone(err, expected, expr_ty, expr);
         self.note_need_for_fn_pointer(err, expected, expr_ty);
         self.note_internal_mutation_in_method(err, expr, expected, expr_ty);
+        self.check_for_range_as_method_call(err, expr, expr_ty, expected);
+        self.check_for_binding_assigned_block_without_tail_expression(err, expr, expr_ty, expected);
+        self.check_wrong_return_type_due_to_generic_arg(err, expr, expr_ty);
     }
 
     /// Requires that the two types unify, and prints an error message if
@@ -163,7 +186,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let expr = expr.peel_drop_temps();
         let cause = self.misc(expr.span);
         let expr_ty = self.resolve_vars_with_obligations(checked_ty);
-        let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e.clone());
+        let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e);
 
         let is_insufficiently_polymorphic =
             matches!(e, TypeError::RegionsInsufficientlyPolymorphic(..));
@@ -189,9 +212,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         err: &mut Diagnostic,
         expr: &hir::Expr<'_>,
-        error: Option<TypeError<'_>>,
+        error: Option<TypeError<'tcx>>,
     ) {
-        let parent = self.tcx.hir().get_parent_node(expr.hir_id);
+        let parent = self.tcx.hir().parent_id(expr.hir_id);
         match (self.tcx.hir().find(parent), error) {
             (Some(hir::Node::Local(hir::Local { ty: Some(ty), init: Some(init), .. })), _)
                 if init.hir_id == expr.hir_id =>
@@ -238,10 +261,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         hir::Path { res: hir::def::Res::Local(hir_id), .. },
                     )) => {
                         if let Some(hir::Node::Pat(pat)) = self.tcx.hir().find(*hir_id) {
-                            let parent = self.tcx.hir().get_parent_node(pat.hir_id);
                             primary_span = pat.span;
                             secondary_span = pat.span;
-                            match self.tcx.hir().find(parent) {
+                            match self.tcx.hir().find_parent(pat.hir_id) {
                                 Some(hir::Node::Local(hir::Local { ty: Some(ty), .. })) => {
                                     primary_span = ty.span;
                                     post_message = " type";
@@ -286,10 +308,177 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     err.downgrade_to_delayed_bug();
                 }
             }
+            (
+                Some(hir::Node::Expr(hir::Expr {
+                    kind: hir::ExprKind::Binary(_, lhs, rhs), ..
+                })),
+                Some(TypeError::Sorts(ExpectedFound { expected, .. })),
+            ) if rhs.hir_id == expr.hir_id
+                && self.typeck_results.borrow().expr_ty_adjusted_opt(lhs) == Some(expected) =>
+            {
+                err.span_label(lhs.span, &format!("expected because this is `{expected}`"));
+            }
             _ => {}
         }
     }
 
+    fn annotate_alternative_method_deref(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'_>,
+        error: Option<TypeError<'tcx>>,
+    ) {
+        let parent = self.tcx.hir().parent_id(expr.hir_id);
+        let Some(TypeError::Sorts(ExpectedFound { expected, .. })) = error else {return;};
+        let Some(hir::Node::Expr(hir::Expr {
+                    kind: hir::ExprKind::Assign(lhs, rhs, _), ..
+                })) = self.tcx.hir().find(parent) else {return; };
+        if rhs.hir_id != expr.hir_id || expected.is_closure() {
+            return;
+        }
+        let hir::ExprKind::Unary(hir::UnOp::Deref, deref) = lhs.kind else { return; };
+        let hir::ExprKind::MethodCall(path, base, args, _) = deref.kind else { return; };
+        let Some(self_ty) = self.typeck_results.borrow().expr_ty_adjusted_opt(base) else { return; };
+
+        let Ok(pick) = self
+            .lookup_probe_for_diagnostic(
+                path.ident,
+                self_ty,
+                deref,
+                probe::ProbeScope::TraitsInScope,
+                None,
+            ) else {
+                return;
+            };
+        let in_scope_methods = self.probe_for_name_many(
+            probe::Mode::MethodCall,
+            path.ident,
+            Some(expected),
+            probe::IsSuggestion(true),
+            self_ty,
+            deref.hir_id,
+            probe::ProbeScope::TraitsInScope,
+        );
+        let other_methods_in_scope: Vec<_> =
+            in_scope_methods.iter().filter(|c| c.item.def_id != pick.item.def_id).collect();
+
+        let all_methods = self.probe_for_name_many(
+            probe::Mode::MethodCall,
+            path.ident,
+            Some(expected),
+            probe::IsSuggestion(true),
+            self_ty,
+            deref.hir_id,
+            probe::ProbeScope::AllTraits,
+        );
+        let suggestions: Vec<_> = all_methods
+            .into_iter()
+            .filter(|c| c.item.def_id != pick.item.def_id)
+            .map(|c| {
+                let m = c.item;
+                let substs = ty::InternalSubsts::for_item(self.tcx, m.def_id, |param, _| {
+                    self.var_for_def(deref.span, param)
+                });
+                vec![
+                    (
+                        deref.span.until(base.span),
+                        format!(
+                            "{}({}",
+                            with_no_trimmed_paths!(
+                                self.tcx.def_path_str_with_substs(m.def_id, substs,)
+                            ),
+                            match self.tcx.fn_sig(m.def_id).input(0).skip_binder().kind() {
+                                ty::Ref(_, _, hir::Mutability::Mut) => "&mut ",
+                                ty::Ref(_, _, _) => "&",
+                                _ => "",
+                            },
+                        ),
+                    ),
+                    match &args[..] {
+                        [] => (base.span.shrink_to_hi().with_hi(deref.span.hi()), ")".to_string()),
+                        [first, ..] => (base.span.between(first.span), ", ".to_string()),
+                    },
+                ]
+            })
+            .collect();
+        if suggestions.is_empty() {
+            return;
+        }
+        let mut path_span: MultiSpan = path.ident.span.into();
+        path_span.push_span_label(
+            path.ident.span,
+            with_no_trimmed_paths!(format!(
+                "refers to `{}`",
+                self.tcx.def_path_str(pick.item.def_id),
+            )),
+        );
+        let container_id = pick.item.container_id(self.tcx);
+        let container = with_no_trimmed_paths!(self.tcx.def_path_str(container_id));
+        for def_id in pick.import_ids {
+            let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
+            path_span.push_span_label(
+                self.tcx.hir().span(hir_id),
+                format!("`{container}` imported here"),
+            );
+        }
+        let tail = with_no_trimmed_paths!(match &other_methods_in_scope[..] {
+            [] => return,
+            [candidate] => format!(
+                "the method of the same name on {} `{}`",
+                match candidate.kind {
+                    probe::CandidateKind::InherentImplCandidate(..) => "the inherent impl for",
+                    _ => "trait",
+                },
+                self.tcx.def_path_str(candidate.item.container_id(self.tcx))
+            ),
+            [.., last] if other_methods_in_scope.len() < 5 => {
+                format!(
+                    "the methods of the same name on {} and `{}`",
+                    other_methods_in_scope[..other_methods_in_scope.len() - 1]
+                        .iter()
+                        .map(|c| format!(
+                            "`{}`",
+                            self.tcx.def_path_str(c.item.container_id(self.tcx))
+                        ))
+                        .collect::<Vec<String>>()
+                        .join(", "),
+                    self.tcx.def_path_str(last.item.container_id(self.tcx))
+                )
+            }
+            _ => format!(
+                "the methods of the same name on {} other traits",
+                other_methods_in_scope.len()
+            ),
+        });
+        err.span_note(
+            path_span,
+            &format!(
+                "the `{}` call is resolved to the method in `{container}`, shadowing {tail}",
+                path.ident,
+            ),
+        );
+        if suggestions.len() > other_methods_in_scope.len() {
+            err.note(&format!(
+                "additionally, there are {} other available methods that aren't in scope",
+                suggestions.len() - other_methods_in_scope.len()
+            ));
+        }
+        err.multipart_suggestions(
+            &format!(
+                "you might have meant to call {}; you can use the fully-qualified path to call {} \
+                 explicitly",
+                if suggestions.len() == 1 {
+                    "the other method"
+                } else {
+                    "one of the other methods"
+                },
+                if suggestions.len() == 1 { "it" } else { "one of them" },
+            ),
+            suggestions,
+            Applicability::MaybeIncorrect,
+        );
+    }
+
     /// If the expected type is an enum (Issue #55250) with any variants whose
     /// sole field is of the found type, suggest such variants. (Issue #42764)
     fn suggest_compatible_variants(
@@ -324,7 +513,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                 // Unroll desugaring, to make sure this works for `for` loops etc.
                 loop {
-                    parent = self.tcx.hir().get_parent_node(id);
+                    parent = self.tcx.hir().parent_id(id);
                     if let Some(parent_span) = self.tcx.hir().opt_span(parent) {
                         if parent_span.find_ancestor_inside(expr.span).is_some() {
                             // The parent node is part of the same span, so is the result of the
@@ -396,7 +585,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
 
                     let note_about_variant_field_privacy = (field_is_local && !field_is_accessible)
-                        .then(|| format!(" (its field is private, but it's local to this crate and its privacy can be changed)"));
+                        .then(|| " (its field is private, but it's local to this crate and its privacy can be changed)".to_string());
 
                     let sole_field_ty = sole_field.ty(self.tcx, substs);
                     if self.can_coerce(expr_ty, sole_field_ty) {
@@ -604,12 +793,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return None;
         };
 
-        let local_parent = self.tcx.hir().get_parent_node(local_id);
+        let local_parent = self.tcx.hir().parent_id(local_id);
         let Some(Node::Param(hir::Param { hir_id: param_hir_id, .. })) = self.tcx.hir().find(local_parent) else {
             return None;
         };
 
-        let param_parent = self.tcx.hir().get_parent_node(*param_hir_id);
+        let param_parent = self.tcx.hir().parent_id(*param_hir_id);
         let Some(Node::Expr(hir::Expr {
             hir_id: expr_hir_id,
             kind: hir::ExprKind::Closure(hir::Closure { fn_decl: closure_fn_decl, .. }),
@@ -618,7 +807,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return None;
         };
 
-        let expr_parent = self.tcx.hir().get_parent_node(*expr_hir_id);
+        let expr_parent = self.tcx.hir().parent_id(*expr_hir_id);
         let hir = self.tcx.hir().find(expr_parent);
         let closure_params_len = closure_fn_decl.inputs.len();
         let (
@@ -671,7 +860,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ => None,
         }?;
 
-        match hir.find(hir.get_parent_node(expr.hir_id))? {
+        match hir.find_parent(expr.hir_id)? {
             Node::ExprField(field) => {
                 if field.ident.name == local.name && field.is_shorthand {
                     return Some(local.name);
@@ -697,7 +886,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Returns whether the given expression is an `else if`.
     pub(crate) fn is_else_if_block(&self, expr: &hir::Expr<'_>) -> bool {
         if let hir::ExprKind::If(..) = expr.kind {
-            let parent_id = self.tcx.hir().get_parent_node(expr.hir_id);
+            let parent_id = self.tcx.hir().parent_id(expr.hir_id);
             if let Some(Node::Expr(hir::Expr {
                 kind: hir::ExprKind::If(_, _, Some(else_expr)),
                 ..
@@ -854,7 +1043,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         if let Some(hir::Node::Expr(hir::Expr {
                             kind: hir::ExprKind::Assign(..),
                             ..
-                        })) = self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id))
+                        })) = self.tcx.hir().find_parent(expr.hir_id)
                         {
                             if mutability.is_mut() {
                                 // Suppressing this diagnostic, we'll properly print it in `check_expr_assign`
@@ -976,7 +1165,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         }
                     }
                     // If we've reached our target type with just removing `&`, then just print now.
-                    if steps == 0 {
+                    if steps == 0 && !remove.trim().is_empty() {
                         return Some((
                             prefix_span,
                             format!("consider removing the `{}`", remove.trim()),
@@ -1035,6 +1224,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         } else {
                             (prefix_span, format!("{}{}", prefix, "*".repeat(steps)))
                         };
+                        if suggestion.trim().is_empty() {
+                            return None;
+                        }
 
                         return Some((
                             span,
@@ -1081,9 +1273,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let mut sugg = vec![];
 
-        if let Some(hir::Node::ExprField(field)) =
-            self.tcx.hir().find(self.tcx.hir().get_parent_node(expr.hir_id))
-        {
+        if let Some(hir::Node::ExprField(field)) = self.tcx.hir().find_parent(expr.hir_id) {
             // `expr` is a literal field for a struct, only suggest if appropriate
             if field.is_shorthand {
                 // This is a field literal
@@ -1265,7 +1455,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             };
 
         match (&expected_ty.kind(), &checked_ty.kind()) {
-            (&ty::Int(ref exp), &ty::Int(ref found)) => {
+            (ty::Int(exp), ty::Int(found)) => {
                 let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width())
                 {
                     (Some(exp), Some(found)) if exp < found => (true, false),
@@ -1278,7 +1468,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible);
                 true
             }
-            (&ty::Uint(ref exp), &ty::Uint(ref found)) => {
+            (ty::Uint(exp), ty::Uint(found)) => {
                 let (f2e_is_fallible, e2f_is_fallible) = match (exp.bit_width(), found.bit_width())
                 {
                     (Some(exp), Some(found)) if exp < found => (true, false),
@@ -1311,7 +1501,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 suggest_to_change_suffix_or_into(err, f2e_is_fallible, e2f_is_fallible);
                 true
             }
-            (&ty::Float(ref exp), &ty::Float(ref found)) => {
+            (ty::Float(exp), ty::Float(found)) => {
                 if found.bit_width() < exp.bit_width() {
                     suggest_to_change_suffix_or_into(err, false, true);
                 } else if literal_is_ty_suffixed(expr) {
@@ -1347,7 +1537,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
                 true
             }
-            (&ty::Float(ref exp), &ty::Uint(ref found)) => {
+            (ty::Float(exp), ty::Uint(found)) => {
                 // if `found` is `None` (meaning found is `usize`), don't suggest `.into()`
                 if exp.bit_width() > found.bit_width().unwrap_or(256) {
                     err.multipart_suggestion_verbose(
@@ -1376,7 +1566,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
                 true
             }
-            (&ty::Float(ref exp), &ty::Int(ref found)) => {
+            (ty::Float(exp), ty::Int(found)) => {
                 // if `found` is `None` (meaning found is `isize`), don't suggest `.into()`
                 if exp.bit_width() > found.bit_width().unwrap_or(256) {
                     err.multipart_suggestion_verbose(
@@ -1422,4 +1612,189 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ => false,
         }
     }
+
+    /// Identify when the user has written `foo..bar()` instead of `foo.bar()`.
+    pub fn check_for_range_as_method_call(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'tcx>,
+        checked_ty: Ty<'tcx>,
+        expected_ty: Ty<'tcx>,
+    ) {
+        if !hir::is_range_literal(expr) {
+            return;
+        }
+        let hir::ExprKind::Struct(
+            hir::QPath::LangItem(LangItem::Range, ..),
+            [start, end],
+            _,
+        ) = expr.kind else { return; };
+        let parent = self.tcx.hir().parent_id(expr.hir_id);
+        if let Some(hir::Node::ExprField(_)) = self.tcx.hir().find(parent) {
+            // Ignore `Foo { field: a..Default::default() }`
+            return;
+        }
+        let mut expr = end.expr;
+        let mut expectation = Some(expected_ty);
+        while let hir::ExprKind::MethodCall(_, rcvr, ..) = expr.kind {
+            // Getting to the root receiver and asserting it is a fn call let's us ignore cases in
+            // `tests/ui/methods/issues/issue-90315.stderr`.
+            expr = rcvr;
+            // If we have more than one layer of calls, then the expected ty
+            // cannot guide the method probe.
+            expectation = None;
+        }
+        let hir::ExprKind::Call(method_name, _) = expr.kind else { return; };
+        let ty::Adt(adt, _) = checked_ty.kind() else { return; };
+        if self.tcx.lang_items().range_struct() != Some(adt.did()) {
+            return;
+        }
+        if let ty::Adt(adt, _) = expected_ty.kind()
+            && self.tcx.lang_items().range_struct() == Some(adt.did())
+        {
+            return;
+        }
+        // Check if start has method named end.
+        let hir::ExprKind::Path(hir::QPath::Resolved(None, p)) = method_name.kind else { return; };
+        let [hir::PathSegment { ident, .. }] = p.segments else { return; };
+        let self_ty = self.typeck_results.borrow().expr_ty(start.expr);
+        let Ok(_pick) = self.lookup_probe_for_diagnostic(
+            *ident,
+            self_ty,
+            expr,
+            probe::ProbeScope::AllTraits,
+            expectation,
+        ) else { return; };
+        let mut sugg = ".";
+        let mut span = start.expr.span.between(end.expr.span);
+        if span.lo() + BytePos(2) == span.hi() {
+            // There's no space between the start, the range op and the end, suggest removal which
+            // will be more noticeable than the replacement of `..` with `.`.
+            span = span.with_lo(span.lo() + BytePos(1));
+            sugg = "";
+        }
+        err.span_suggestion_verbose(
+            span,
+            "you likely meant to write a method call instead of a range",
+            sugg,
+            Applicability::MachineApplicable,
+        );
+    }
+
+    /// Identify when the type error is because `()` is found in a binding that was assigned a
+    /// block without a tail expression.
+    fn check_for_binding_assigned_block_without_tail_expression(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'_>,
+        checked_ty: Ty<'tcx>,
+        expected_ty: Ty<'tcx>,
+    ) {
+        if !checked_ty.is_unit() {
+            return;
+        }
+        let hir::ExprKind::Path(hir::QPath::Resolved(None, path)) = expr.kind else { return; };
+        let hir::def::Res::Local(hir_id) = path.res else { return; };
+        let Some(hir::Node::Pat(pat)) = self.tcx.hir().find(hir_id) else {
+            return;
+        };
+        let Some(hir::Node::Local(hir::Local {
+            ty: None,
+            init: Some(init),
+            ..
+        })) = self.tcx.hir().find_parent(pat.hir_id) else { return; };
+        let hir::ExprKind::Block(block, None) = init.kind else { return; };
+        if block.expr.is_some() {
+            return;
+        }
+        let [.., stmt] = block.stmts else {
+            err.span_label(block.span, "this empty block is missing a tail expression");
+            return;
+        };
+        let hir::StmtKind::Semi(tail_expr) = stmt.kind else { return; };
+        let Some(ty) = self.node_ty_opt(tail_expr.hir_id) else { return; };
+        if self.can_eq(self.param_env, expected_ty, ty).is_ok() {
+            err.span_suggestion_short(
+                stmt.span.with_lo(tail_expr.span.hi()),
+                "remove this semicolon",
+                "",
+                Applicability::MachineApplicable,
+            );
+        } else {
+            err.span_label(block.span, "this block is missing a tail expression");
+        }
+    }
+
+    fn check_wrong_return_type_due_to_generic_arg(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'_>,
+        checked_ty: Ty<'tcx>,
+    ) {
+        let Some(hir::Node::Expr(parent_expr)) = self.tcx.hir().find_parent(expr.hir_id) else { return; };
+        enum CallableKind {
+            Function,
+            Method,
+            Constructor,
+        }
+        let mut maybe_emit_help = |def_id: hir::def_id::DefId,
+                                   callable: rustc_span::symbol::Ident,
+                                   args: &[hir::Expr<'_>],
+                                   kind: CallableKind| {
+            let arg_idx = args.iter().position(|a| a.hir_id == expr.hir_id).unwrap();
+            let fn_ty = self.tcx.bound_type_of(def_id).0;
+            if !fn_ty.is_fn() {
+                return;
+            }
+            let fn_sig = fn_ty.fn_sig(self.tcx).skip_binder();
+            let Some(&arg) = fn_sig.inputs().get(arg_idx + if matches!(kind, CallableKind::Method) { 1 } else { 0 }) else { return; };
+            if matches!(arg.kind(), ty::Param(_))
+                && fn_sig.output().contains(arg)
+                && self.node_ty(args[arg_idx].hir_id) == checked_ty
+            {
+                let mut multi_span: MultiSpan = parent_expr.span.into();
+                multi_span.push_span_label(
+                    args[arg_idx].span,
+                    format!(
+                        "this argument influences the {} of `{}`",
+                        if matches!(kind, CallableKind::Constructor) {
+                            "type"
+                        } else {
+                            "return type"
+                        },
+                        callable
+                    ),
+                );
+                err.span_help(
+                    multi_span,
+                    format!(
+                        "the {} `{}` due to the type of the argument passed",
+                        match kind {
+                            CallableKind::Function => "return type of this call is",
+                            CallableKind::Method => "return type of this call is",
+                            CallableKind::Constructor => "type constructed contains",
+                        },
+                        checked_ty
+                    ),
+                );
+            }
+        };
+        match parent_expr.kind {
+            hir::ExprKind::Call(fun, args) => {
+                let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = fun.kind else { return; };
+                let hir::def::Res::Def(kind, def_id) = path.res else { return; };
+                let callable_kind = if matches!(kind, hir::def::DefKind::Ctor(_, _)) {
+                    CallableKind::Constructor
+                } else {
+                    CallableKind::Function
+                };
+                maybe_emit_help(def_id, path.segments[0].ident, args, callable_kind);
+            }
+            hir::ExprKind::MethodCall(method, _receiver, args, _span) => {
+                let Some(def_id) = self.typeck_results.borrow().type_dependent_def_id(parent_expr.hir_id) else { return; };
+                maybe_emit_help(def_id, method.ident, args, CallableKind::Method)
+            }
+            _ => return,
+        }
+    }
 }
diff --git a/compiler/rustc_hir_typeck/src/errors.rs b/compiler/rustc_hir_typeck/src/errors.rs
index 507272fde..5b4fd5e4a 100644
--- a/compiler/rustc_hir_typeck/src/errors.rs
+++ b/compiler/rustc_hir_typeck/src/errors.rs
@@ -172,3 +172,36 @@ impl AddToDiagnostic for TypeMismatchFruTypo {
         );
     }
 }
+
+#[derive(Diagnostic)]
+#[diag(hir_typeck_lang_start_incorrect_number_params)]
+#[note(hir_typeck_lang_start_incorrect_number_params_note_expected_count)]
+#[note(hir_typeck_lang_start_expected_sig_note)]
+pub struct LangStartIncorrectNumberArgs {
+    #[primary_span]
+    pub params_span: Span,
+    pub found_param_count: usize,
+}
+
+#[derive(Diagnostic)]
+#[diag(hir_typeck_lang_start_incorrect_param)]
+pub struct LangStartIncorrectParam<'tcx> {
+    #[primary_span]
+    #[suggestion(style = "short", code = "{expected_ty}", applicability = "machine-applicable")]
+    pub param_span: Span,
+
+    pub param_num: usize,
+    pub expected_ty: Ty<'tcx>,
+    pub found_ty: Ty<'tcx>,
+}
+
+#[derive(Diagnostic)]
+#[diag(hir_typeck_lang_start_incorrect_ret_ty)]
+pub struct LangStartIncorrectRetTy<'tcx> {
+    #[primary_span]
+    #[suggestion(style = "short", code = "{expected_ty}", applicability = "machine-applicable")]
+    pub ret_span: Span,
+
+    pub expected_ty: Ty<'tcx>,
+    pub found_ty: Ty<'tcx>,
+}
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index ed87b94a0..bc7474cdf 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -104,16 +104,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         if let Some(mut err) = self.demand_suptype_diag(expr.span, expected_ty, ty) {
-            // FIXME(compiler-errors): We probably should fold some of the
-            // `suggest_` functions from  `emit_coerce_suggestions` into here,
-            // since some of those aren't necessarily just coerce suggestions.
-            let _ = self.suggest_deref_ref_or_into(
+            let _ = self.emit_type_mismatch_suggestions(
                 &mut err,
                 expr.peel_drop_temps(),
-                expected_ty,
                 ty,
+                expected_ty,
                 None,
-            ) || self.suggest_option_to_bool(&mut err, expr, ty, expected_ty);
+                None,
+            );
             extend_err(&mut err);
             err.emit();
         }
@@ -236,6 +234,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ) => self.check_expr_path(qpath, expr, args),
             _ => self.check_expr_kind(expr, expected),
         });
+        let ty = self.resolve_vars_if_possible(ty);
 
         // Warn for non-block expressions with diverging children.
         match expr.kind {
@@ -352,7 +351,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ExprKind::Struct(qpath, fields, ref base_expr) => {
                 self.check_expr_struct(expr, expected, qpath, fields, base_expr)
             }
-            ExprKind::Field(base, field) => self.check_field(expr, &base, field),
+            ExprKind::Field(base, field) => self.check_field(expr, &base, field, expected),
             ExprKind::Index(base, idx) => self.check_expr_index(base, idx, expr),
             ExprKind::Yield(value, ref src) => self.check_expr_yield(value, expr, src),
             hir::ExprKind::Err => tcx.ty_error(),
@@ -397,7 +396,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             E0614,
                             "type `{oprnd_t}` cannot be dereferenced",
                         );
-                        let sp = tcx.sess.source_map().start_point(expr.span);
+                        let sp = tcx.sess.source_map().start_point(expr.span).with_parent(None);
                         if let Some(sp) =
                             tcx.sess.parse_sess.ambiguous_block_expr_parse.borrow().get(&sp)
                         {
@@ -460,9 +459,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             hir::BorrowKind::Ref => {
                 // Note: at this point, we cannot say what the best lifetime
-                // is to use for resulting pointer.  We want to use the
+                // is to use for resulting pointer. We want to use the
                 // shortest lifetime possible so as to avoid spurious borrowck
-                // errors.  Moreover, the longest lifetime will depend on the
+                // errors. Moreover, the longest lifetime will depend on the
                 // precise details of the value whose address is being taken
                 // (and how long it is valid), which we don't know yet until
                 // type inference is complete.
@@ -688,7 +687,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             } else {
                 // If `ctxt.coerce` is `None`, we can just ignore
-                // the type of the expression.  This is because
+                // the type of the expression. This is because
                 // either this was a break *without* a value, in
                 // which case it is always a legal type (`()`), or
                 // else an error would have been flagged by the
@@ -922,7 +921,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         original_expr_id: HirId,
         then: impl FnOnce(&hir::Expr<'_>),
     ) {
-        let mut parent = self.tcx.hir().get_parent_node(original_expr_id);
+        let mut parent = self.tcx.hir().parent_id(original_expr_id);
         while let Some(node) = self.tcx.hir().find(parent) {
             match node {
                 hir::Node::Expr(hir::Expr {
@@ -945,7 +944,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }) => {
                     // Check if our original expression is a child of the condition of a while loop
                     let expr_is_ancestor = std::iter::successors(Some(original_expr_id), |id| {
-                        self.tcx.hir().find_parent_node(*id)
+                        self.tcx.hir().opt_parent_id(*id)
                     })
                     .take_while(|id| *id != parent)
                     .any(|id| id == expr.hir_id);
@@ -961,7 +960,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 | hir::Node::TraitItem(_)
                 | hir::Node::Crate(_) => break,
                 _ => {
-                    parent = self.tcx.hir().get_parent_node(parent);
+                    parent = self.tcx.hir().parent_id(parent);
                 }
             }
         }
@@ -1085,7 +1084,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // Do not suggest `if let x = y` as `==` is way more likely to be the intention.
                 let hir = self.tcx.hir();
                 if let hir::Node::Expr(hir::Expr { kind: ExprKind::If { .. }, .. }) =
-                    hir.get(hir.get_parent_node(hir.get_parent_node(expr.hir_id)))
+                    hir.get_parent(hir.parent_id(expr.hir_id))
                 {
                     err.span_suggestion_verbose(
                         expr.span.shrink_to_lo(),
@@ -1245,6 +1244,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         SelfSource::MethodCall(rcvr),
                         error,
                         Some((rcvr, args)),
+                        expected,
                     ) {
                         err.emit();
                     }
@@ -1874,7 +1874,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // I don't use 'is_range_literal' because only double-sided, half-open ranges count.
         if let ExprKind::Struct(
                 QPath::LangItem(LangItem::Range, ..),
-                &[ref range_start, ref range_end],
+                [range_start, range_end],
                 _,
             ) = last_expr_field.expr.kind
             && let variant_field =
@@ -2187,6 +2187,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expr: &'tcx hir::Expr<'tcx>,
         base: &'tcx hir::Expr<'tcx>,
         field: Ident,
+        expected: Expectation<'tcx>,
     ) -> Ty<'tcx> {
         debug!("check_field(expr: {:?}, base: {:?}, field: {:?})", expr, base, field);
         let base_ty = self.check_expr(base);
@@ -2218,7 +2219,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             self.tcx.check_stability(field.did, Some(expr.hir_id), expr.span, None);
                             return field_ty;
                         }
-                        private_candidate = Some((adjustments, base_def.did(), field_ty));
+                        private_candidate = Some((adjustments, base_def.did()));
                     }
                 }
                 ty::Tuple(tys) => {
@@ -2241,16 +2242,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
         self.structurally_resolved_type(autoderef.span(), autoderef.final_ty(false));
 
-        if let Some((adjustments, did, field_ty)) = private_candidate {
+        if let Some((adjustments, did)) = private_candidate {
             // (#90483) apply adjustments to avoid ExprUseVisitor from
             // creating erroneous projection.
             self.apply_adjustments(base, adjustments);
-            self.ban_private_field_access(expr, base_ty, field, did);
-            return field_ty;
+            self.ban_private_field_access(expr, base_ty, field, did, expected.only_has_type(self));
+            return self.tcx().ty_error();
         }
 
         if field.name == kw::Empty {
-        } else if self.method_exists(field, base_ty, expr.hir_id, true) {
+        } else if self.method_exists(
+            field,
+            base_ty,
+            expr.hir_id,
+            true,
+            expected.only_has_type(self),
+        ) {
             self.ban_take_value_of_method(expr, base_ty, field);
         } else if !base_ty.is_primitive_ty() {
             self.ban_nonexisting_field(field, base, expr, base_ty);
@@ -2391,7 +2398,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ty::Param(param_ty) => {
                 self.point_at_param_definition(&mut err, param_ty);
             }
-            ty::Opaque(_, _) => {
+            ty::Alias(ty::Opaque, _) => {
                 self.suggest_await_on_field_access(&mut err, ident, base, base_ty.peel_refs());
             }
             _ => {}
@@ -2424,10 +2431,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     fn ban_private_field_access(
         &self,
-        expr: &hir::Expr<'_>,
+        expr: &hir::Expr<'tcx>,
         expr_t: Ty<'tcx>,
         field: Ident,
         base_did: DefId,
+        return_ty: Option<Ty<'tcx>>,
     ) {
         let struct_path = self.tcx().def_path_str(base_did);
         let kind_name = self.tcx().def_kind(base_did).descr(base_did);
@@ -2439,7 +2447,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
         err.span_label(field.span, "private field");
         // Also check if an accessible method exists, which is often what is meant.
-        if self.method_exists(field, expr_t, expr.hir_id, false) && !self.expr_in_place(expr.hir_id)
+        if self.method_exists(field, expr_t, expr.hir_id, false, return_ty)
+            && !self.expr_in_place(expr.hir_id)
         {
             self.suggest_method_call(
                 &mut err,
@@ -2453,7 +2462,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err.emit();
     }
 
-    fn ban_take_value_of_method(&self, expr: &hir::Expr<'_>, expr_t: Ty<'tcx>, field: Ident) {
+    fn ban_take_value_of_method(&self, expr: &hir::Expr<'tcx>, expr_t: Ty<'tcx>, field: Ident) {
         let mut err = type_error_struct!(
             self.tcx().sess,
             field.span,
@@ -2464,7 +2473,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err.span_label(field.span, "method, not a field");
         let expr_is_call =
             if let hir::Node::Expr(hir::Expr { kind: ExprKind::Call(callee, _args), .. }) =
-                self.tcx.hir().get(self.tcx.hir().get_parent_node(expr.hir_id))
+                self.tcx.hir().get_parent(expr.hir_id)
             {
                 expr.hir_id == callee.hir_id
             } else {
diff --git a/compiler/rustc_hir_typeck/src/expr_use_visitor.rs b/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
index 03b174c77..c8cda0dc9 100644
--- a/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
+++ b/compiler/rustc_hir_typeck/src/expr_use_visitor.rs
@@ -417,7 +417,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
                                 // Named constants have to be equated with the value
                                 // being matched, so that's a read of the value being matched.
                                 //
-                                // FIXME: We don't actually  reads for ZSTs.
+                                // FIXME: We don't actually reads for ZSTs.
                                 needs_to_be_read = true;
                             }
                             _ => {
@@ -756,8 +756,8 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
     /// - When reporting the Place back to the Delegate, ensure that the UpvarId uses the enclosing
     /// closure as the DefId.
     fn walk_captures(&mut self, closure_expr: &hir::Closure<'_>) {
-        fn upvar_is_local_variable<'tcx>(
-            upvars: Option<&'tcx FxIndexMap<hir::HirId, hir::Upvar>>,
+        fn upvar_is_local_variable(
+            upvars: Option<&FxIndexMap<hir::HirId, hir::Upvar>>,
             upvar_id: hir::HirId,
             body_owner_is_closure: bool,
         ) -> bool {
diff --git a/compiler/rustc_hir_typeck/src/fallback.rs b/compiler/rustc_hir_typeck/src/fallback.rs
index ac6b0924a..dde879780 100644
--- a/compiler/rustc_hir_typeck/src/fallback.rs
+++ b/compiler/rustc_hir_typeck/src/fallback.rs
@@ -42,7 +42,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
         // We now see if we can make progress. This might cause us to
         // unify inference variables for opaque types, since we may
         // have unified some other type variables during the first
-        // phase of fallback.  This means that we only replace
+        // phase of fallback. This means that we only replace
         // inference variables with their underlying opaque types as a
         // last resort.
         //
@@ -76,7 +76,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
     //   (and the setting of `#![feature(never_type_fallback)]`).
     //
     // Fallback becomes very dubious if we have encountered
-    // type-checking errors.  In that case, fallback to Error.
+    // type-checking errors. In that case, fallback to Error.
     //
     // Sets `FnCtxt::fallback_has_occurred` if fallback is performed
     // during this call.
@@ -136,7 +136,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
     /// constrained to have some other type).
     ///
     /// However, the fallback used to be `()` (before the `!` type was
-    /// added).  Moreover, there are cases where the `!` type 'leaks
+    /// added). Moreover, there are cases where the `!` type 'leaks
     /// out' from dead code into type variables that affect live
     /// code. The most common case is something like this:
     ///
@@ -149,7 +149,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
     /// ```
     ///
     /// Here, coercing the type `!` into `?M` will create a diverging
-    /// type variable `?X` where `?X <: ?M`.  We also have that `?D <:
+    /// type variable `?X` where `?X <: ?M`. We also have that `?D <:
     /// ?M`. If `?M` winds up unconstrained, then `?X` will
     /// fallback. If it falls back to `!`, then all the type variables
     /// will wind up equal to `!` -- this includes the type `?D`
@@ -185,7 +185,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
     ///
     /// The algorithm we use:
     /// * Identify all variables that are coerced *into* by a
-    ///   diverging variable.  Do this by iterating over each
+    ///   diverging variable. Do this by iterating over each
     ///   diverging, unsolved variable and finding all variables
     ///   reachable from there. Call that set `D`.
     /// * Walk over all unsolved, non-diverging variables, and find
@@ -308,7 +308,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
 
             if relationship.self_in_trait && relationship.output {
                 // This case falls back to () to ensure that the code pattern in
-                // src/test/ui/never_type/fallback-closure-ret.rs continues to
+                // tests/ui/never_type/fallback-closure-ret.rs continues to
                 // compile when never_type_fallback is enabled.
                 //
                 // This rule is not readily explainable from first principles,
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 952d27262..6ed8adb47 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -1,7 +1,7 @@
 use crate::callee::{self, DeferredCallResolution};
 use crate::method::{self, MethodCallee, SelfSource};
 use crate::rvalue_scopes;
-use crate::{BreakableCtxt, Diverges, Expectation, FnCtxt, LocalTy};
+use crate::{BreakableCtxt, Diverges, Expectation, FnCtxt, LocalTy, RawTy};
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, Diagnostic, ErrorGuaranteed, MultiSpan};
@@ -10,6 +10,9 @@ use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{ExprKind, GenericArg, Node, QPath};
+use rustc_hir_analysis::astconv::generics::{
+    check_generic_arg_count_for_call, create_substs_for_generic_args,
+};
 use rustc_hir_analysis::astconv::{
     AstConv, CreateSubstsForGenericArgsCtxt, ExplicitLateBound, GenericArgCountMismatch,
     GenericArgCountResult, IsMethodCall, PathSeg,
@@ -22,9 +25,9 @@ use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{
-    self, AdtKind, CanonicalUserType, DefIdTree, EarlyBinder, GenericParamDefKind, Ty, UserType,
+    self, AdtKind, CanonicalUserType, DefIdTree, GenericParamDefKind, Ty, UserType,
 };
-use rustc_middle::ty::{GenericArgKind, InternalSubsts, SubstsRef, UserSelfTy, UserSubsts};
+use rustc_middle::ty::{GenericArgKind, SubstsRef, UserSelfTy, UserSubsts};
 use rustc_session::lint;
 use rustc_span::def_id::LocalDefId;
 use rustc_span::hygiene::DesugaringKind;
@@ -161,47 +164,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub fn write_method_call(&self, hir_id: hir::HirId, method: MethodCallee<'tcx>) {
         self.write_resolution(hir_id, Ok((DefKind::AssocFn, method.def_id)));
         self.write_substs(hir_id, method.substs);
-
-        // When the method is confirmed, the `method.substs` includes
-        // parameters from not just the method, but also the impl of
-        // the method -- in particular, the `Self` type will be fully
-        // resolved. However, those are not something that the "user
-        // specified" -- i.e., those types come from the inferred type
-        // of the receiver, not something the user wrote. So when we
-        // create the user-substs, we want to replace those earlier
-        // types with just the types that the user actually wrote --
-        // that is, those that appear on the *method itself*.
-        //
-        // As an example, if the user wrote something like
-        // `foo.bar::<u32>(...)` -- the `Self` type here will be the
-        // type of `foo` (possibly adjusted), but we don't want to
-        // include that. We want just the `[_, u32]` part.
-        if !method.substs.is_empty() {
-            let method_generics = self.tcx.generics_of(method.def_id);
-            if !method_generics.params.is_empty() {
-                let user_type_annotation = self.probe(|_| {
-                    let user_substs = UserSubsts {
-                        substs: InternalSubsts::for_item(self.tcx, method.def_id, |param, _| {
-                            let i = param.index as usize;
-                            if i < method_generics.parent_count {
-                                self.var_for_def(DUMMY_SP, param)
-                            } else {
-                                method.substs[i]
-                            }
-                        }),
-                        user_self_ty: None, // not relevant here
-                    };
-
-                    self.canonicalize_user_type_annotation(UserType::TypeOf(
-                        method.def_id,
-                        user_substs,
-                    ))
-                });
-
-                debug!("write_method_call: user_type_annotation={:?}", user_type_annotation);
-                self.write_user_type_annotation(hir_id, user_type_annotation);
-            }
-        }
     }
 
     pub fn write_substs(&self, node_id: hir::HirId, substs: SubstsRef<'tcx>) {
@@ -333,22 +295,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    /// Basically whenever we are converting from a type scheme into
-    /// the fn body space, we always want to normalize associated
-    /// types as well. This function combines the two.
-    fn instantiate_type_scheme<T>(&self, span: Span, substs: SubstsRef<'tcx>, value: T) -> T
-    where
-        T: TypeFoldable<'tcx>,
-    {
-        debug!("instantiate_type_scheme(value={:?}, substs={:?})", value, substs);
-        let value = EarlyBinder(value).subst(self.tcx, substs);
-        let result = self.normalize(span, value);
-        debug!("instantiate_type_scheme = {:?}", result);
-        result
-    }
-
-    /// As `instantiate_type_scheme`, but for the bounds found in a
-    /// generic type scheme.
+    /// Instantiates and normalizes the bounds for a given item
     pub(in super::super) fn instantiate_bounds(
         &self,
         span: Span,
@@ -425,23 +372,38 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn to_ty(&self, ast_t: &hir::Ty<'_>) -> Ty<'tcx> {
-        let t = <dyn AstConv<'_>>::ast_ty_to_ty(self, ast_t);
+    pub fn handle_raw_ty(&self, span: Span, ty: Ty<'tcx>) -> RawTy<'tcx> {
+        RawTy { raw: ty, normalized: self.normalize(span, ty) }
+    }
+
+    pub fn to_ty(&self, ast_t: &hir::Ty<'_>) -> RawTy<'tcx> {
+        let t = self.astconv().ast_ty_to_ty(ast_t);
         self.register_wf_obligation(t.into(), ast_t.span, traits::WellFormed(None));
-        t
+        self.handle_raw_ty(ast_t.span, t)
     }
 
     pub fn to_ty_saving_user_provided_ty(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> {
         let ty = self.to_ty(ast_ty);
         debug!("to_ty_saving_user_provided_ty: ty={:?}", ty);
 
-        if Self::can_contain_user_lifetime_bounds(ty) {
-            let c_ty = self.canonicalize_response(UserType::Ty(ty));
+        if Self::can_contain_user_lifetime_bounds(ty.raw) {
+            let c_ty = self.canonicalize_response(UserType::Ty(ty.raw));
             debug!("to_ty_saving_user_provided_ty: c_ty={:?}", c_ty);
             self.typeck_results.borrow_mut().user_provided_types_mut().insert(ast_ty.hir_id, c_ty);
         }
 
-        ty
+        ty.normalized
+    }
+
+    pub(super) fn user_substs_for_adt(ty: RawTy<'tcx>) -> UserSubsts<'tcx> {
+        match (ty.raw.kind(), ty.normalized.kind()) {
+            (ty::Adt(_, substs), _) => UserSubsts { substs, user_self_ty: None },
+            (_, ty::Adt(adt, substs)) => UserSubsts {
+                substs,
+                user_self_ty: Some(UserSelfTy { impl_def_id: adt.did(), self_ty: ty.raw }),
+            },
+            _ => bug!("non-adt type {:?}", ty),
+        }
     }
 
     pub fn array_length_to_const(&self, length: &hir::ArrayLen) -> ty::Const<'tcx> {
@@ -711,12 +673,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Note: this check is pessimistic, as the inference type could be matched with something other
         // than the opaque type, but then we need a new `TypeRelation` just for this specific case and
         // can't re-use `sup` below.
-        // See src/test/ui/impl-trait/hidden-type-is-opaque.rs and
-        // src/test/ui/impl-trait/hidden-type-is-opaque-2.rs for examples that hit this path.
+        // See tests/ui/impl-trait/hidden-type-is-opaque.rs and
+        // tests/ui/impl-trait/hidden-type-is-opaque-2.rs for examples that hit this path.
         if formal_ret.has_infer_types() {
             for ty in ret_ty.walk() {
                 if let ty::subst::GenericArgKind::Type(ty) = ty.unpack()
-                    && let ty::Opaque(def_id, _) = *ty.kind()
+                    && let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *ty.kind()
                     && let Some(def_id) = def_id.as_local()
                     && self.opaque_type_origin(def_id, DUMMY_SP).is_some() {
                     return None;
@@ -795,7 +757,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         qpath: &'tcx QPath<'tcx>,
         hir_id: hir::HirId,
         span: Span,
-    ) -> (Res, Option<Ty<'tcx>>, &'tcx [hir::PathSegment<'tcx>]) {
+    ) -> (Res, Option<RawTy<'tcx>>, &'tcx [hir::PathSegment<'tcx>]) {
         debug!(
             "resolve_ty_and_res_fully_qualified_call: qpath={:?} hir_id={:?} span={:?}",
             qpath, hir_id, span
@@ -818,7 +780,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // to be object-safe.
                 // We manually call `register_wf_obligation` in the success path
                 // below.
-                (<dyn AstConv<'_>>::ast_ty_to_ty_in_path(self, qself), qself, segment)
+                let ty = self.astconv().ast_ty_to_ty_in_path(qself);
+                (self.handle_raw_ty(span, ty), qself, segment)
             }
             QPath::LangItem(..) => {
                 bug!("`resolve_ty_and_res_fully_qualified_call` called on `LangItem`")
@@ -826,7 +789,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         if let Some(&cached_result) = self.typeck_results.borrow().type_dependent_defs().get(hir_id)
         {
-            self.register_wf_obligation(ty.into(), qself.span, traits::WellFormed(None));
+            self.register_wf_obligation(ty.raw.into(), qself.span, traits::WellFormed(None));
             // Return directly on cache hit. This is useful to avoid doubly reporting
             // errors with default match binding modes. See #44614.
             let def = cached_result.map_or(Res::Err, |(kind, def_id)| Res::Def(kind, def_id));
@@ -834,7 +797,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
         let item_name = item_segment.ident;
         let result = self
-            .resolve_fully_qualified_call(span, item_name, ty, qself.span, hir_id)
+            .resolve_fully_qualified_call(span, item_name, ty.normalized, qself.span, hir_id)
             .or_else(|error| {
                 let result = match error {
                     method::MethodError::PrivateMatch(kind, def_id, _) => Ok((kind, def_id)),
@@ -845,17 +808,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // a WF obligation for `dyn MyTrait` when method lookup fails. Otherwise,
                 // register a WF obligation so that we can detect any additional
                 // errors in the self type.
-                if !(matches!(error, method::MethodError::NoMatch(_)) && ty.is_trait()) {
-                    self.register_wf_obligation(ty.into(), qself.span, traits::WellFormed(None));
+                if !(matches!(error, method::MethodError::NoMatch(_)) && ty.normalized.is_trait()) {
+                    self.register_wf_obligation(
+                        ty.raw.into(),
+                        qself.span,
+                        traits::WellFormed(None),
+                    );
                 }
                 if item_name.name != kw::Empty {
                     if let Some(mut e) = self.report_method_error(
                         span,
-                        ty,
+                        ty.normalized,
                         item_name,
                         SelfSource::QPath(qself),
                         error,
                         None,
+                        Expectation::NoExpectation,
                     ) {
                         e.emit();
                     }
@@ -864,7 +832,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             });
 
         if result.is_ok() {
-            self.register_wf_obligation(ty.into(), qself.span, traits::WellFormed(None));
+            self.register_wf_obligation(ty.raw.into(), qself.span, traits::WellFormed(None));
         }
 
         // Write back the new resolution.
@@ -1001,7 +969,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub fn instantiate_value_path(
         &self,
         segments: &[hir::PathSegment<'_>],
-        self_ty: Option<Ty<'tcx>>,
+        self_ty: Option<RawTy<'tcx>>,
         res: Res,
         span: Span,
         hir_id: hir::HirId,
@@ -1010,8 +978,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let path_segs = match res {
             Res::Local(_) | Res::SelfCtor(_) => vec![],
-            Res::Def(kind, def_id) => <dyn AstConv<'_>>::def_ids_for_value_path_segments(
-                self, segments, self_ty, kind, def_id,
+            Res::Def(kind, def_id) => self.astconv().def_ids_for_value_path_segments(
+                segments,
+                self_ty.map(|ty| ty.raw),
+                kind,
+                def_id,
+                span,
             ),
             _ => bug!("instantiate_value_path on {:?}", res),
         };
@@ -1022,8 +994,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             Res::Def(DefKind::Ctor(CtorOf::Variant, _), _)
                 if let Some(self_ty) = self_ty =>
             {
-                let adt_def = self_ty.ty_adt_def().unwrap();
-                user_self_ty = Some(UserSelfTy { impl_def_id: adt_def.did(), self_ty });
+                let adt_def = self_ty.normalized.ty_adt_def().unwrap();
+                user_self_ty = Some(UserSelfTy { impl_def_id: adt_def.did(), self_ty: self_ty.raw });
                 is_alias_variant_ctor = true;
             }
             Res::Def(DefKind::AssocFn | DefKind::AssocConst, def_id) => {
@@ -1042,7 +1014,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             // inherent impl, we need to record the
                             // `T` for posterity (see `UserSelfTy` for
                             // details).
-                            let self_ty = self_ty.expect("UFCS sugared assoc missing Self");
+                            let self_ty = self_ty.expect("UFCS sugared assoc missing Self").raw;
                             user_self_ty = Some(UserSelfTy { impl_def_id: container_id, self_ty });
                         }
                     }
@@ -1057,8 +1029,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // errors if type parameters are provided in an inappropriate place.
 
         let generic_segs: FxHashSet<_> = path_segs.iter().map(|PathSeg(_, index)| index).collect();
-        let generics_has_err = <dyn AstConv<'_>>::prohibit_generics(
-            self,
+        let generics_has_err = self.astconv().prohibit_generics(
             segments.iter().enumerate().filter_map(|(index, seg)| {
                 if !generic_segs.contains(&index) || is_alias_variant_ctor {
                     Some(seg)
@@ -1099,7 +1070,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // parameter internally, but we don't allow users to specify the
             // parameter's value explicitly, so we have to do some error-
             // checking here.
-            let arg_count = <dyn AstConv<'_>>::check_generic_arg_count_for_call(
+            let arg_count = check_generic_arg_count_for_call(
                 tcx,
                 span,
                 def_id,
@@ -1124,19 +1095,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .unwrap_or(false);
 
         let (res, self_ctor_substs) = if let Res::SelfCtor(impl_def_id) = res {
-            let ty = self.normalize_ty(span, tcx.at(span).type_of(impl_def_id));
-            match *ty.kind() {
-                ty::Adt(adt_def, substs) if adt_def.has_ctor() => {
-                    let variant = adt_def.non_enum_variant();
-                    let (ctor_kind, ctor_def_id) = variant.ctor.unwrap();
-                    (Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id), Some(substs))
+            let ty = self.handle_raw_ty(span, tcx.at(span).type_of(impl_def_id));
+            match ty.normalized.ty_adt_def() {
+                Some(adt_def) if adt_def.has_ctor() => {
+                    let (ctor_kind, ctor_def_id) = adt_def.non_enum_variant().ctor.unwrap();
+                    let new_res = Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
+                    let user_substs = Self::user_substs_for_adt(ty);
+                    user_self_ty = user_substs.user_self_ty;
+                    (new_res, Some(user_substs.substs))
                 }
                 _ => {
                     let mut err = tcx.sess.struct_span_err(
                         span,
                         "the `Self` constructor can only be used with tuple or unit structs",
                     );
-                    if let Some(adt_def) = ty.ty_adt_def() {
+                    if let Some(adt_def) = ty.normalized.ty_adt_def() {
                         match adt_def.adt_kind() {
                             AdtKind::Enum => {
                                 err.help("did you mean to use one of the enum's variants?");
@@ -1160,10 +1133,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
         let def_id = res.def_id();
 
-        // The things we are substituting into the type should not contain
-        // escaping late-bound regions, and nor should the base type scheme.
-        let ty = tcx.type_of(def_id);
-
         let arg_count = GenericArgCountResult {
             explicit_late_bound,
             correct: if infer_args_for_err.is_empty() {
@@ -1209,10 +1178,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ) -> ty::GenericArg<'tcx> {
                 match (&param.kind, arg) {
                     (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => {
-                        <dyn AstConv<'_>>::ast_region_to_region(self.fcx, lt, Some(param)).into()
+                        self.fcx.astconv().ast_region_to_region(lt, Some(param)).into()
                     }
                     (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => {
-                        self.fcx.to_ty(ty).into()
+                        self.fcx.to_ty(ty).raw.into()
                     }
                     (GenericParamDefKind::Const { .. }, GenericArg::Const(ct)) => {
                         self.fcx.const_arg_to_const(&ct.value, param.def_id).into()
@@ -1244,10 +1213,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             // If we have a default, then we it doesn't matter that we're not
                             // inferring the type arguments: we provide the default where any
                             // is missing.
-                            let default = tcx.bound_type_of(param.def_id);
-                            self.fcx
-                                .normalize_ty(self.span, default.subst(tcx, substs.unwrap()))
-                                .into()
+                            tcx.bound_type_of(param.def_id).subst(tcx, substs.unwrap()).into()
                         } else {
                             // If no type arguments were provided, we have to infer them.
                             // This case also occurs as a result of some malformed input, e.g.
@@ -1258,9 +1224,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                     GenericParamDefKind::Const { has_default } => {
                         if !infer_args && has_default {
-                            tcx.bound_const_param_default(param.def_id)
-                                .subst(tcx, substs.unwrap())
-                                .into()
+                            tcx.const_param_default(param.def_id).subst(tcx, substs.unwrap()).into()
                         } else {
                             self.fcx.var_for_def(self.span, param)
                         }
@@ -1269,13 +1233,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         }
 
-        let substs = self_ctor_substs.unwrap_or_else(|| {
-            <dyn AstConv<'_>>::create_substs_for_generic_args(
+        let substs_raw = self_ctor_substs.unwrap_or_else(|| {
+            create_substs_for_generic_args(
                 tcx,
                 def_id,
                 &[],
                 has_self,
-                self_ty,
+                self_ty.map(|s| s.raw),
                 &arg_count,
                 &mut CreateCtorSubstsContext {
                     fcx: self,
@@ -1286,17 +1250,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 },
             )
         });
-        assert!(!substs.has_escaping_bound_vars());
-        assert!(!ty.has_escaping_bound_vars());
 
         // First, store the "user substs" for later.
-        self.write_user_type_annotation_from_substs(hir_id, def_id, substs, user_self_ty);
+        self.write_user_type_annotation_from_substs(hir_id, def_id, substs_raw, user_self_ty);
+
+        // Normalize only after registering type annotations.
+        let substs = self.normalize(span, substs_raw);
 
         self.add_required_obligations_for_hir(span, def_id, &substs, hir_id);
 
         // Substitute the values for the type parameters into the type of
         // the referenced item.
-        let ty_substituted = self.instantiate_type_scheme(span, &substs, ty);
+        let ty = tcx.bound_type_of(def_id);
+        assert!(!substs.has_escaping_bound_vars());
+        assert!(!ty.0.has_escaping_bound_vars());
+        let ty_substituted = self.normalize(span, ty.subst(tcx, substs));
 
         if let Some(UserSelfTy { impl_def_id, self_ty }) = user_self_ty {
             // In the case of `Foo<T>::method` and `<Foo<T>>::method`, if `method`
@@ -1304,9 +1272,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // type parameters, which we can infer by unifying the provided `Self`
             // with the substituted impl type.
             // This also occurs for an enum variant on a type alias.
-            let ty = tcx.type_of(impl_def_id);
-
-            let impl_ty = self.instantiate_type_scheme(span, &substs, ty);
+            let impl_ty = self.normalize(span, tcx.bound_type_of(impl_def_id).subst(tcx, substs));
+            let self_ty = self.normalize(span, self_ty);
             match self.at(&self.misc(span), self.param_env).eq(impl_ty, self_ty) {
                 Ok(ok) => self.register_infer_ok_obligations(ok),
                 Err(_) => {
@@ -1455,9 +1422,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub(in super::super) fn expr_in_place(&self, mut expr_id: hir::HirId) -> bool {
         let mut contained_in_place = false;
 
-        while let hir::Node::Expr(parent_expr) =
-            self.tcx.hir().get(self.tcx.hir().get_parent_node(expr_id))
-        {
+        while let hir::Node::Expr(parent_expr) = self.tcx.hir().get_parent(expr_id) {
             match &parent_expr.kind {
                 hir::ExprKind::Assign(lhs, ..) | hir::ExprKind::AssignOp(_, lhs, ..) => {
                     if lhs.hir_id == expr_id {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs
index fc83994ca..6f26afcaf 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/arg_matrix.rs
@@ -4,15 +4,13 @@ use rustc_index::vec::IndexVec;
 use rustc_middle::ty::error::TypeError;
 
 rustc_index::newtype_index! {
-    pub(crate) struct ExpectedIdx {
-        DEBUG_FORMAT = "ExpectedIdx({})",
-    }
+    #[debug_format = "ExpectedIdx({})"]
+    pub(crate) struct ExpectedIdx {}
 }
 
 rustc_index::newtype_index! {
-    pub(crate) struct ProvidedIdx {
-        DEBUG_FORMAT = "ProvidedIdx({})",
-    }
+    #[debug_format = "ProvidedIdx({})"]
+    pub(crate) struct ProvidedIdx {}
 }
 
 impl ExpectedIdx {
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 60fec05d3..2d841d53f 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -5,11 +5,11 @@ use crate::method::MethodCallee;
 use crate::Expectation::*;
 use crate::TupleArgumentsFlag::*;
 use crate::{
-    struct_span_err, BreakableCtxt, Diverges, Expectation, FnCtxt, LocalTy, Needs,
+    struct_span_err, BreakableCtxt, Diverges, Expectation, FnCtxt, LocalTy, Needs, RawTy,
     TupleArgumentsFlag,
 };
 use rustc_ast as ast;
-use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::{pluralize, Applicability, Diagnostic, DiagnosticId, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
@@ -28,7 +28,7 @@ use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty, TypeSuperVisitable, TypeVisitor};
 use rustc_session::Session;
-use rustc_span::symbol::Ident;
+use rustc_span::symbol::{kw, Ident};
 use rustc_span::{self, sym, Span};
 use rustc_trait_selection::traits::{self, ObligationCauseCode, SelectionContext};
 
@@ -214,7 +214,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         "cannot use call notation; the first type parameter \
                          for the function trait is neither a tuple nor unit"
                     )
-                    .delay_as_bug();
+                    .emit();
                     (self.err_args(provided_args.len()), None)
                 }
             }
@@ -473,7 +473,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         call_expr: &hir::Expr<'tcx>,
     ) {
         // Next, let's construct the error
-        let (error_span, full_call_span, ctor_of, is_method) = match &call_expr.kind {
+        let (error_span, full_call_span, call_name, is_method) = match &call_expr.kind {
             hir::ExprKind::Call(
                 hir::Expr { hir_id, span, kind: hir::ExprKind::Path(qpath), .. },
                 _,
@@ -481,12 +481,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 if let Res::Def(DefKind::Ctor(of, _), _) =
                     self.typeck_results.borrow().qpath_res(qpath, *hir_id)
                 {
-                    (call_span, *span, Some(of), false)
+                    let name = match of {
+                        CtorOf::Struct => "struct",
+                        CtorOf::Variant => "enum variant",
+                    };
+                    (call_span, *span, name, false)
                 } else {
-                    (call_span, *span, None, false)
+                    (call_span, *span, "function", false)
                 }
             }
-            hir::ExprKind::Call(hir::Expr { span, .. }, _) => (call_span, *span, None, false),
+            hir::ExprKind::Call(hir::Expr { span, .. }, _) => (call_span, *span, "function", false),
             hir::ExprKind::MethodCall(path_segment, _, _, span) => {
                 let ident_span = path_segment.ident.span;
                 let ident_span = if let Some(args) = path_segment.args {
@@ -494,17 +498,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 } else {
                     ident_span
                 };
-                // methods are never ctors
-                (*span, ident_span, None, true)
+                (*span, ident_span, "method", true)
             }
             k => span_bug!(call_span, "checking argument types on a non-call: `{:?}`", k),
         };
         let args_span = error_span.trim_start(full_call_span).unwrap_or(error_span);
-        let call_name = match ctor_of {
-            Some(CtorOf::Struct) => "struct",
-            Some(CtorOf::Variant) => "enum variant",
-            None => "function",
-        };
 
         // Don't print if it has error types or is just plain `_`
         fn has_error_or_infer<'tcx>(tys: impl IntoIterator<Item = Ty<'tcx>>) -> bool {
@@ -690,8 +688,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         err = tcx.sess.struct_span_err_with_code(
                             full_call_span,
                             &format!(
-                                "this {} takes {}{} but {} {} supplied",
-                                call_name,
+                                "{call_name} takes {}{} but {} {} supplied",
                                 if c_variadic { "at least " } else { "" },
                                 potentially_plural_count(
                                     formal_and_expected_inputs.len(),
@@ -1013,7 +1010,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             } else {
                                 args_span
                             };
-                            labels.push((span, format!("multiple arguments are missing")));
+                            labels.push((span, "multiple arguments are missing".to_string()));
                             suggestion_text = match suggestion_text {
                                 SuggestionText::None | SuggestionText::Provide(_) => {
                                     SuggestionText::Provide(true)
@@ -1141,6 +1138,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         "()".to_string()
                     } else if expected_ty.is_suggestable(tcx, false) {
                         format!("/* {} */", expected_ty)
+                    } else if let Some(fn_def_id) = fn_def_id
+                        && self.tcx.def_kind(fn_def_id).is_fn_like()
+                        && let self_implicit = matches!(call_expr.kind, hir::ExprKind::MethodCall(..)) as usize
+                        && let Some(arg) = self.tcx.fn_arg_names(fn_def_id).get(expected_idx.as_usize() + self_implicit)
+                        && arg.name != kw::SelfLower
+                    {
+                        format!("/* {} */", arg.name)
                     } else {
                         "/* value */".to_string()
                     }
@@ -1169,7 +1173,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         match lit.node {
             ast::LitKind::Str(..) => tcx.mk_static_str(),
-            ast::LitKind::ByteStr(ref v) => {
+            ast::LitKind::ByteStr(ref v, _) => {
                 tcx.mk_imm_ref(tcx.lifetimes.re_static, tcx.mk_array(tcx.types.u8, v.len() as u64))
             }
             ast::LitKind::Byte(_) => tcx.types.u8,
@@ -1215,31 +1219,35 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 );
                 return None;
             }
-            Res::Def(DefKind::Variant, _) => match ty.kind() {
-                ty::Adt(adt, substs) => Some((adt.variant_of_res(def), adt.did(), substs)),
-                _ => bug!("unexpected type: {:?}", ty),
+            Res::Def(DefKind::Variant, _) => match ty.normalized.ty_adt_def() {
+                Some(adt) => {
+                    Some((adt.variant_of_res(def), adt.did(), Self::user_substs_for_adt(ty)))
+                }
+                _ => bug!("unexpected type: {:?}", ty.normalized),
             },
             Res::Def(DefKind::Struct | DefKind::Union | DefKind::TyAlias | DefKind::AssocTy, _)
             | Res::SelfTyParam { .. }
-            | Res::SelfTyAlias { .. } => match ty.kind() {
-                ty::Adt(adt, substs) if !adt.is_enum() => {
-                    Some((adt.non_enum_variant(), adt.did(), substs))
+            | Res::SelfTyAlias { .. } => match ty.normalized.ty_adt_def() {
+                Some(adt) if !adt.is_enum() => {
+                    Some((adt.non_enum_variant(), adt.did(), Self::user_substs_for_adt(ty)))
                 }
                 _ => None,
             },
             _ => bug!("unexpected definition: {:?}", def),
         };
 
-        if let Some((variant, did, substs)) = variant {
+        if let Some((variant, did, ty::UserSubsts { substs, user_self_ty })) = variant {
             debug!("check_struct_path: did={:?} substs={:?}", did, substs);
-            self.write_user_type_annotation_from_substs(hir_id, did, substs, None);
+
+            // Register type annotation.
+            self.write_user_type_annotation_from_substs(hir_id, did, substs, user_self_ty);
 
             // Check bounds on type arguments used in the path.
             self.add_required_obligations_for_hir(path_span, did, substs, hir_id);
 
-            Some((variant, ty))
+            Some((variant, ty.normalized))
         } else {
-            match ty.kind() {
+            match ty.normalized.kind() {
                 ty::Error(_) => {
                     // E0071 might be caused by a spelling error, which will have
                     // already caused an error message and probably a suggestion
@@ -1252,7 +1260,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         path_span,
                         E0071,
                         "expected struct, variant or union type, found {}",
-                        ty.sort_string(self.tcx)
+                        ty.normalized.sort_string(self.tcx)
                     )
                     .span_label(path_span, "not a struct")
                     .emit();
@@ -1300,7 +1308,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Type check the initializer.
         if let Some(ref init) = decl.init {
             let init_ty = self.check_decl_initializer(decl.hir_id, decl.pat, &init);
-            self.overwrite_local_ty_if_err(decl.hir_id, decl.pat, decl_ty, init_ty);
+            self.overwrite_local_ty_if_err(decl.hir_id, decl.pat, init_ty);
         }
 
         // Does the expected pattern type originate from an expression and what is the span?
@@ -1315,7 +1323,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Type check the pattern. Override if necessary to avoid knock-on errors.
         self.check_pat_top(&decl.pat, decl_ty, ty_span, origin_expr);
         let pat_ty = self.node_ty(decl.pat.hir_id);
-        self.overwrite_local_ty_if_err(decl.hir_id, decl.pat, decl_ty, pat_ty);
+        self.overwrite_local_ty_if_err(decl.hir_id, decl.pat, pat_ty);
 
         if let Some(blk) = decl.els {
             let previous_diverges = self.diverges.get();
@@ -1620,14 +1628,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         hir_id: hir::HirId,
         pat: &'tcx hir::Pat<'tcx>,
-        decl_ty: Ty<'tcx>,
         ty: Ty<'tcx>,
     ) {
         if ty.references_error() {
             // Override the types everywhere with `err()` to avoid knock on errors.
-            self.write_ty(hir_id, ty);
-            self.write_ty(pat.hir_id, ty);
-            let local_ty = LocalTy { decl_ty, revealed_ty: ty };
+            let err = self.tcx.ty_error();
+            self.write_ty(hir_id, err);
+            self.write_ty(pat.hir_id, err);
+            let local_ty = LocalTy { decl_ty: err, revealed_ty: err };
             self.locals.borrow_mut().insert(hir_id, local_ty);
             self.locals.borrow_mut().insert(pat.hir_id, local_ty);
         }
@@ -1640,20 +1648,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         qpath: &QPath<'_>,
         path_span: Span,
         hir_id: hir::HirId,
-    ) -> (Res, Ty<'tcx>) {
+    ) -> (Res, RawTy<'tcx>) {
         match *qpath {
             QPath::Resolved(ref maybe_qself, ref path) => {
-                let self_ty = maybe_qself.as_ref().map(|qself| self.to_ty(qself));
-                let ty = <dyn AstConv<'_>>::res_to_ty(self, self_ty, path, true);
-                (path.res, ty)
+                let self_ty = maybe_qself.as_ref().map(|qself| self.to_ty(qself).raw);
+                let ty = self.astconv().res_to_ty(self_ty, path, true);
+                (path.res, self.handle_raw_ty(path_span, ty))
             }
             QPath::TypeRelative(ref qself, ref segment) => {
                 let ty = self.to_ty(qself);
 
-                let result = <dyn AstConv<'_>>::associated_path_to_ty(
-                    self, hir_id, path_span, ty, qself, segment, true,
-                );
+                let result = self
+                    .astconv()
+                    .associated_path_to_ty(hir_id, path_span, ty.raw, qself, segment, true);
                 let ty = result.map(|(ty, _, _)| ty).unwrap_or_else(|_| self.tcx().ty_error());
+                let ty = self.handle_raw_ty(path_span, ty);
                 let result = result.map(|(_, kind, def_id)| (kind, def_id));
 
                 // Write back the new resolution.
@@ -1662,7 +1671,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 (result.map_or(Res::Err, |(kind, def_id)| Res::Def(kind, def_id)), ty)
             }
             QPath::LangItem(lang_item, span, id) => {
-                self.resolve_lang_item_path(lang_item, span, hir_id, id)
+                let (res, ty) = self.resolve_lang_item_path(lang_item, span, hir_id, id);
+                (res, self.handle_raw_ty(path_span, ty))
             }
         }
     }
@@ -1682,7 +1692,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // even if their `ObligationCauseCode` isn't an `Expr*Obligation` kind.
         // This is important since if we adjust one span but not the other, then
         // we will have "duplicated" the error on the UI side.
-        let mut remap_cause = FxHashSet::default();
+        let mut remap_cause = FxIndexSet::default();
         let mut not_adjusted = vec![];
 
         for error in errors {
@@ -1710,6 +1720,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         }
 
+        // Adjust any other errors that come from other cause codes, when these
+        // errors are of the same predicate as one we successfully adjusted, and
+        // when their spans overlap (suggesting they're due to the same root cause).
+        //
+        // This is because due to normalization, we often register duplicate
+        // obligations with misc obligations that are basically impossible to
+        // line back up with a useful ExprBindingObligation.
         for error in not_adjusted {
             for (span, predicate, cause) in &remap_cause {
                 if *predicate == error.obligation.predicate
@@ -1796,7 +1813,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     hir_id: call_hir_id,
                     span: call_span,
                     ..
-                }) = hir.get(hir.get_parent_node(expr.hir_id))
+                }) = hir.get_parent(expr.hir_id)
                     && callee.hir_id == expr.hir_id
                 {
                     if self.closure_span_overlaps_error(error, *call_span) {
@@ -2111,8 +2128,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         // FIXME(compiler-errors): This could be problematic if something has two
                         // fn-like predicates with different args, but callable types really never
                         // do that, so it's OK.
-                        for (predicate, span) in
-                            std::iter::zip(instantiated.predicates, instantiated.spans)
+                        for (predicate, span) in instantiated
                         {
                             if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = predicate.kind().skip_binder()
                                 && pred.self_ty().peel_refs() == callee_ty
@@ -2124,7 +2140,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         }
                     }
                 }
-                ty::Opaque(new_def_id, _)
+                ty::Alias(ty::Opaque, ty::AliasTy { def_id: new_def_id, .. })
                 | ty::Closure(new_def_id, _)
                 | ty::FnDef(new_def_id, _) => {
                     def_id = new_def_id;
@@ -2132,19 +2148,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 _ => {
                     // Look for a user-provided impl of a `Fn` trait, and point to it.
                     let new_def_id = self.probe(|_| {
-                        let trait_ref = ty::TraitRef::new(
+                        let trait_ref = self.tcx.mk_trait_ref(
                             call_kind.to_def_id(self.tcx),
-                            self.tcx.mk_substs(
-                                [
-                                    ty::GenericArg::from(callee_ty),
-                                    self.next_ty_var(TypeVariableOrigin {
-                                        kind: TypeVariableOriginKind::MiscVariable,
-                                        span: rustc_span::DUMMY_SP,
-                                    })
-                                    .into(),
-                                ]
-                                .into_iter(),
-                            ),
+                            [
+                                callee_ty,
+                                self.next_ty_var(TypeVariableOrigin {
+                                    kind: TypeVariableOriginKind::MiscVariable,
+                                    span: rustc_span::DUMMY_SP,
+                                }),
+                            ],
                         );
                         let obligation = traits::Obligation::new(
                             self.tcx,
@@ -2217,7 +2229,7 @@ fn find_param_in_ty<'tcx>(ty: Ty<'tcx>, param_to_point_at: ty::GenericArg<'tcx>)
         if arg == param_to_point_at {
             return true;
         } else if let ty::GenericArgKind::Type(ty) = arg.unpack()
-            && let ty::Projection(..) = ty.kind()
+            && let ty::Alias(ty::Projection, ..) = ty.kind()
         {
             // This logic may seem a bit strange, but typically when
             // we have a projection type in a function signature, the
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
index 30b59da78..428fde642 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
@@ -17,11 +17,10 @@ use rustc_infer::infer::error_reporting::TypeErrCtxt;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKind};
 use rustc_middle::ty::subst::GenericArgKind;
-use rustc_middle::ty::visit::TypeVisitable;
-use rustc_middle::ty::{self, Const, Ty, TyCtxt};
+use rustc_middle::ty::{self, Const, Ty, TyCtxt, TypeVisitable};
 use rustc_session::Session;
 use rustc_span::symbol::Ident;
-use rustc_span::{self, Span};
+use rustc_span::{self, Span, DUMMY_SP};
 use rustc_trait_selection::traits::{ObligationCause, ObligationCauseCode, ObligationCtxt};
 
 use std::cell::{Cell, RefCell};
@@ -176,6 +175,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     fn_sig
                 })
             }),
+            autoderef_steps: Box::new(|ty| {
+                let mut autoderef = self.autoderef(DUMMY_SP, ty).silence_errors();
+                let mut steps = vec![];
+                while let Some((ty, _)) = autoderef.next() {
+                    steps.push((ty, autoderef.current_obligations()));
+                }
+                steps
+            }),
         }
     }
 
@@ -287,8 +294,7 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
             poly_trait_ref,
         );
 
-        let item_substs = <dyn AstConv<'tcx>>::create_substs_for_associated_item(
-            self,
+        let item_substs = self.astconv().create_substs_for_associated_item(
             span,
             item_def_id,
             item_segment,
@@ -298,11 +304,14 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
         self.tcx().mk_projection(item_def_id, item_substs)
     }
 
-    fn normalize_ty(&self, span: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
-        if ty.has_escaping_bound_vars() {
-            ty // FIXME: normalization and escaping regions
-        } else {
-            self.normalize(span, ty)
+    fn probe_adt(&self, span: Span, ty: Ty<'tcx>) -> Option<ty::AdtDef<'tcx>> {
+        match ty.kind() {
+            ty::Adt(adt_def, _) => Some(*adt_def),
+            // FIXME(#104767): Should we handle bound regions here?
+            ty::Alias(ty::Projection, _) if !ty.has_escaping_bound_vars() => {
+                self.normalize(span, ty).ty_adt_def()
+            }
+            _ => None,
         }
     }
 
@@ -310,7 +319,21 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
         self.infcx.set_tainted_by_errors(e)
     }
 
-    fn record_ty(&self, hir_id: hir::HirId, ty: Ty<'tcx>, _span: Span) {
+    fn record_ty(&self, hir_id: hir::HirId, ty: Ty<'tcx>, span: Span) {
+        // FIXME: normalization and escaping regions
+        let ty = if !ty.has_escaping_bound_vars() { self.normalize(span, ty) } else { ty };
         self.write_ty(hir_id, ty)
     }
 }
+
+/// Represents a user-provided type in the raw form (never normalized).
+///
+/// This is a bridge between the interface of `AstConv`, which outputs a raw `Ty`,
+/// and the API in this module, which expect `Ty` to be fully normalized.
+#[derive(Clone, Copy, Debug)]
+pub struct RawTy<'tcx> {
+    pub raw: Ty<'tcx>,
+
+    /// The normalized form of `raw`, stored here for efficiency.
+    pub normalized: Ty<'tcx>,
+}
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 4f92477b5..4d673ac91 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -1,33 +1,37 @@
 use super::FnCtxt;
 
 use crate::errors::{AddReturnTypeSuggestion, ExpectedReturnTypeLabel};
+use crate::method::probe::{IsSuggestion, Mode, ProbeScope};
 use rustc_ast::util::parser::{ExprPrecedence, PREC_POSTFIX};
 use rustc_errors::{Applicability, Diagnostic, MultiSpan};
 use rustc_hir as hir;
-use rustc_hir::def::{CtorOf, DefKind};
+use rustc_hir::def::{CtorKind, CtorOf, DefKind};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{
     Expr, ExprKind, GenericBound, Node, Path, QPath, Stmt, StmtKind, TyKind, WherePredicate,
 };
 use rustc_hir_analysis::astconv::AstConv;
-use rustc_infer::infer;
 use rustc_infer::traits::{self, StatementAsExpression};
 use rustc_middle::lint::in_external_macro;
-use rustc_middle::ty::{self, Binder, DefIdTree, IsSuggestable, ToPredicate, Ty};
+use rustc_middle::ty::{
+    self, suggest_constraining_type_params, Binder, DefIdTree, IsSuggestable, ToPredicate, Ty,
+    TypeVisitable,
+};
 use rustc_session::errors::ExprParenthesesNeeded;
-use rustc_span::symbol::sym;
-use rustc_span::Span;
+use rustc_span::source_map::Spanned;
+use rustc_span::symbol::{sym, Ident};
+use rustc_span::{Span, Symbol};
 use rustc_trait_selection::infer::InferCtxtExt;
+use rustc_trait_selection::traits::error_reporting::suggestions::TypeErrCtxtExt;
 use rustc_trait_selection::traits::error_reporting::DefIdOrName;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
-use rustc_trait_selection::traits::NormalizeExt;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub(crate) fn body_fn_sig(&self) -> Option<ty::FnSig<'tcx>> {
         self.typeck_results
             .borrow()
             .liberated_fn_sigs()
-            .get(self.tcx.hir().get_parent_node(self.body_id))
+            .get(self.tcx.hir().parent_id(self.body_id))
             .copied()
     }
 
@@ -89,7 +93,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         found: Ty<'tcx>,
         can_satisfy: impl FnOnce(Ty<'tcx>) -> bool,
     ) -> bool {
-        let Some((def_id_or_name, output, inputs)) = self.extract_callable_info(expr, found)
+        let Some((def_id_or_name, output, inputs)) = self.extract_callable_info(found)
             else { return false; };
         if can_satisfy(output) {
             let (sugg_call, mut applicability) = match inputs.len() {
@@ -158,99 +162,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// because the callable type must also be well-formed to be called.
     pub(in super::super) fn extract_callable_info(
         &self,
-        expr: &Expr<'_>,
-        found: Ty<'tcx>,
+        ty: Ty<'tcx>,
     ) -> Option<(DefIdOrName, Ty<'tcx>, Vec<Ty<'tcx>>)> {
-        // Autoderef is useful here because sometimes we box callables, etc.
-        let Some((def_id_or_name, output, inputs)) = self.autoderef(expr.span, found).silence_errors().find_map(|(found, _)| {
-            match *found.kind() {
-                ty::FnPtr(fn_sig) =>
-                    Some((DefIdOrName::Name("function pointer"), fn_sig.output(), fn_sig.inputs())),
-                ty::FnDef(def_id, _) => {
-                    let fn_sig = found.fn_sig(self.tcx);
-                    Some((DefIdOrName::DefId(def_id), fn_sig.output(), fn_sig.inputs()))
-                }
-                ty::Closure(def_id, substs) => {
-                    let fn_sig = substs.as_closure().sig();
-                    Some((DefIdOrName::DefId(def_id), fn_sig.output(), fn_sig.inputs().map_bound(|inputs| &inputs[1..])))
-                }
-                ty::Opaque(def_id, substs) => {
-                    self.tcx.bound_item_bounds(def_id).subst(self.tcx, substs).iter().find_map(|pred| {
-                        if let ty::PredicateKind::Clause(ty::Clause::Projection(proj)) = pred.kind().skip_binder()
-                        && Some(proj.projection_ty.item_def_id) == self.tcx.lang_items().fn_once_output()
-                        // args tuple will always be substs[1]
-                        && let ty::Tuple(args) = proj.projection_ty.substs.type_at(1).kind()
-                        {
-                            Some((
-                                DefIdOrName::DefId(def_id),
-                                pred.kind().rebind(proj.term.ty().unwrap()),
-                                pred.kind().rebind(args.as_slice()),
-                            ))
-                        } else {
-                            None
-                        }
-                    })
-                }
-                ty::Dynamic(data, _, ty::Dyn) => {
-                    data.iter().find_map(|pred| {
-                        if let ty::ExistentialPredicate::Projection(proj) = pred.skip_binder()
-                        && Some(proj.item_def_id) == self.tcx.lang_items().fn_once_output()
-                        // for existential projection, substs are shifted over by 1
-                        && let ty::Tuple(args) = proj.substs.type_at(0).kind()
-                        {
-                            Some((
-                                DefIdOrName::Name("trait object"),
-                                pred.rebind(proj.term.ty().unwrap()),
-                                pred.rebind(args.as_slice()),
-                            ))
-                        } else {
-                            None
-                        }
-                    })
-                }
-                ty::Param(param) => {
-                    let def_id = self.tcx.generics_of(self.body_id.owner).type_param(&param, self.tcx).def_id;
-                    self.tcx.predicates_of(self.body_id.owner).predicates.iter().find_map(|(pred, _)| {
-                        if let ty::PredicateKind::Clause(ty::Clause::Projection(proj)) = pred.kind().skip_binder()
-                        && Some(proj.projection_ty.item_def_id) == self.tcx.lang_items().fn_once_output()
-                        && proj.projection_ty.self_ty() == found
-                        // args tuple will always be substs[1]
-                        && let ty::Tuple(args) = proj.projection_ty.substs.type_at(1).kind()
-                        {
-                            Some((
-                                DefIdOrName::DefId(def_id),
-                                pred.kind().rebind(proj.term.ty().unwrap()),
-                                pred.kind().rebind(args.as_slice()),
-                            ))
-                        } else {
-                            None
-                        }
-                    })
-                }
-                _ => None,
-            }
-        }) else { return None; };
-
-        let output = self.replace_bound_vars_with_fresh_vars(expr.span, infer::FnCall, output);
-        let inputs = inputs
-            .skip_binder()
-            .iter()
-            .map(|ty| {
-                self.replace_bound_vars_with_fresh_vars(
-                    expr.span,
-                    infer::FnCall,
-                    inputs.rebind(*ty),
-                )
-            })
-            .collect();
-
-        // We don't want to register any extra obligations, which should be
-        // implied by wf, but also because that would possibly result in
-        // erroneous errors later on.
-        let infer::InferOk { value: output, obligations: _ } =
-            self.at(&self.misc(expr.span), self.param_env).normalize(output);
-
-        if output.is_ty_var() { None } else { Some((def_id_or_name, output, inputs)) }
+        self.err_ctxt().extract_callable_info(self.body_id, self.param_env, ty)
     }
 
     pub fn suggest_two_fn_call(
@@ -262,9 +176,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         rhs_ty: Ty<'tcx>,
         can_satisfy: impl FnOnce(Ty<'tcx>, Ty<'tcx>) -> bool,
     ) -> bool {
-        let Some((_, lhs_output_ty, lhs_inputs)) = self.extract_callable_info(lhs_expr, lhs_ty)
+        let Some((_, lhs_output_ty, lhs_inputs)) = self.extract_callable_info(lhs_ty)
             else { return false; };
-        let Some((_, rhs_output_ty, rhs_inputs)) = self.extract_callable_info(rhs_expr, rhs_ty)
+        let Some((_, rhs_output_ty, rhs_inputs)) = self.extract_callable_info(rhs_ty)
             else { return false; };
 
         if can_satisfy(lhs_output_ty, rhs_output_ty) {
@@ -317,11 +231,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             }
 
-            err.multipart_suggestion_verbose(
-                format!("use parentheses to call these"),
-                sugg,
-                applicability,
-            );
+            err.multipart_suggestion_verbose("use parentheses to call these", sugg, applicability);
 
             true
         } else {
@@ -329,6 +239,31 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    pub fn suggest_remove_last_method_call(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'tcx>,
+        expected: Ty<'tcx>,
+    ) -> bool {
+        if let hir::ExprKind::MethodCall(hir::PathSegment { ident: method, .. }, recv_expr, &[], _) = expr.kind &&
+            let Some(recv_ty) = self.typeck_results.borrow().expr_ty_opt(recv_expr) &&
+            self.can_coerce(recv_ty, expected) {
+                let span = if let Some(recv_span) = recv_expr.span.find_ancestor_inside(expr.span) {
+                    expr.span.with_lo(recv_span.hi())
+                } else {
+                    expr.span.with_lo(method.span.lo() - rustc_span::BytePos(1))
+                };
+                err.span_suggestion_verbose(
+                    span,
+                    "try removing the method call",
+                    "",
+                    Applicability::MachineApplicable,
+                );
+                return true;
+            }
+        false
+    }
+
     pub fn suggest_deref_ref_or_into(
         &self,
         err: &mut Diagnostic,
@@ -391,10 +326,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else if self.suggest_else_fn_with_closure(err, expr, found, expected) {
             return true;
         } else if self.suggest_fn_call(err, expr, found, |output| self.can_coerce(output, expected))
-            && let ty::FnDef(def_id, ..) = &found.kind()
-            && let Some(sp) = self.tcx.hir().span_if_local(*def_id)
+            && let ty::FnDef(def_id, ..) = *found.kind()
+            && let Some(sp) = self.tcx.hir().span_if_local(def_id)
         {
-            err.span_label(sp, format!("{found} defined here"));
+            let name = self.tcx.item_name(def_id);
+            let kind = self.tcx.def_kind(def_id);
+            if let DefKind::Ctor(of, CtorKind::Fn) = kind {
+                err.span_label(sp, format!("`{name}` defines {} constructor here, which should be called", match of {
+                    CtorOf::Struct => "a struct",
+                    CtorOf::Variant => "an enum variant",
+                }));
+            } else {
+                let descr = kind.descr(def_id);
+                err.span_label(sp, format!("{descr} `{name}` defined here"));
+            }
             return true;
         } else if self.check_for_cast(err, expr, found, expected, expected_ty_expr) {
             return true;
@@ -416,7 +361,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             && method_call_list.contains(&conversion_method.name)
                             // If receiver is `.clone()` and found type has one of those methods,
                             // we guess that the user wants to convert from a slice type (`&[]` or `&str`)
-                            // to an owned type (`Vec` or `String`).  These conversions clone internally,
+                            // to an owned type (`Vec` or `String`). These conversions clone internally,
                             // so we remove the user's `clone` call.
                         {
                             vec![(
@@ -613,10 +558,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             }
             ty::Adt(def, _) if def.is_box() && self.can_coerce(box_found, expected) => {
-                // Check if the parent expression is a call to Pin::new.  If it
+                // Check if the parent expression is a call to Pin::new. If it
                 // is and we were expecting a Box, ergo Pin<Box<expected>>, we
                 // can suggest Box::pin.
-                let parent = self.tcx.hir().get_parent_node(expr.hir_id);
+                let parent = self.tcx.hir().parent_id(expr.hir_id);
                 let Some(Node::Expr(Expr { kind: ExprKind::Call(fn_name, _), .. })) = self.tcx.hir().find(parent) else {
                     return false;
                 };
@@ -752,12 +697,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     return true
                 }
             }
-            &hir::FnRetTy::Return(ref ty) => {
+            hir::FnRetTy::Return(ty) => {
                 // Only point to return type if the expected type is the return type, as if they
                 // are not, the expectation must have been caused by something else.
                 debug!("suggest_missing_return_type: return type {:?} node {:?}", ty, ty.kind);
                 let span = ty.span;
-                let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, ty);
+                let ty = self.astconv().ast_ty_to_ty(ty);
                 debug!("suggest_missing_return_type: return type {:?}", ty);
                 debug!("suggest_missing_return_type: expected type {:?}", ty);
                 let bound_vars = self.tcx.late_bound_vars(fn_id);
@@ -828,7 +773,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     ..
                 }) => {
                     // FIXME: Maybe these calls to `ast_ty_to_ty` can be removed (and the ones below)
-                    let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, bounded_ty);
+                    let ty = self.astconv().ast_ty_to_ty(bounded_ty);
                     Some((ty, bounds))
                 }
                 _ => None,
@@ -866,7 +811,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let all_bounds_str = all_matching_bounds_strs.join(" + ");
 
         let ty_param_used_in_fn_params = fn_parameters.iter().any(|param| {
-                let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, param);
+                let ty = self.astconv().ast_ty_to_ty( param);
                 matches!(ty.kind(), ty::Param(fn_param_ty_param) if expected_ty_as_param == fn_param_ty_param)
             });
 
@@ -920,7 +865,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         if let hir::FnRetTy::Return(ty) = fn_decl.output {
-            let ty = <dyn AstConv<'_>>::ast_ty_to_ty(self, ty);
+            let ty = self.astconv().ast_ty_to_ty(ty);
             let bound_vars = self.tcx.late_bound_vars(fn_id);
             let ty = self.tcx.erase_late_bound_regions(Binder::bind_with_vars(ty, bound_vars));
             let ty = match self.tcx.asyncness(fn_id.owner) {
@@ -948,7 +893,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err: &mut Diagnostic,
         expr: &hir::Expr<'_>,
     ) -> bool {
-        let sp = self.tcx.sess.source_map().start_point(expr.span);
+        let sp = self.tcx.sess.source_map().start_point(expr.span).with_parent(None);
         if let Some(sp) = self.tcx.sess.parse_sess.ambiguous_block_expr_parse.borrow().get(&sp) {
             // `{ 42 } &&x` (#61475) or `{ 42 } && if x { 1 } else { 0 }`
             err.subdiagnostic(ExprParenthesesNeeded::surrounding(*sp));
@@ -988,6 +933,36 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    pub(crate) fn suggest_clone_for_ref(
+        &self,
+        diag: &mut Diagnostic,
+        expr: &hir::Expr<'_>,
+        expr_ty: Ty<'tcx>,
+        expected_ty: Ty<'tcx>,
+    ) -> bool {
+        if let ty::Ref(_, inner_ty, hir::Mutability::Not) = expr_ty.kind()
+            && let Some(clone_trait_def) = self.tcx.lang_items().clone_trait()
+            && expected_ty == *inner_ty
+            && self
+                .infcx
+                .type_implements_trait(
+                    clone_trait_def,
+                    [self.tcx.erase_regions(expected_ty)],
+                    self.param_env
+                )
+                .must_apply_modulo_regions()
+          {
+              diag.span_suggestion_verbose(
+                  expr.span.shrink_to_hi(),
+                  "consider using clone here",
+                  ".clone()",
+                  Applicability::MachineApplicable,
+              );
+              return true;
+          }
+        false
+    }
+
     pub(crate) fn suggest_copied_or_cloned(
         &self,
         diag: &mut Diagnostic,
@@ -1126,9 +1101,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         let hir = self.tcx.hir();
-        let cond_parent = hir.parent_iter(expr.hir_id).skip_while(|(_, node)| {
-            matches!(node, hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Binary(op, _, _), .. }) if op.node == hir::BinOpKind::And)
-        }).next();
+        let cond_parent = hir.parent_iter(expr.hir_id).find(|(_, node)| {
+            !matches!(node, hir::Node::Expr(hir::Expr { kind: hir::ExprKind::Binary(op, _, _), .. }) if op.node == hir::BinOpKind::And)
+        });
         // Don't suggest:
         //     `let Some(_) = a.is_some() && b`
         //                     ++++++++++
@@ -1234,10 +1209,114 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 );
                 true
             }
+            ExprKind::Lit(Spanned {
+                node: rustc_ast::LitKind::Int(lit, rustc_ast::LitIntType::Unsuffixed),
+                span,
+            }) => {
+                let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) else { return false; };
+                if !(snippet.starts_with("0x") || snippet.starts_with("0X")) {
+                    return false;
+                }
+                if snippet.len() <= 5 || !snippet.is_char_boundary(snippet.len() - 3) {
+                    return false;
+                }
+                let (_, suffix) = snippet.split_at(snippet.len() - 3);
+                let value = match suffix {
+                    "f32" => (lit - 0xf32) / (16 * 16 * 16),
+                    "f64" => (lit - 0xf64) / (16 * 16 * 16),
+                    _ => return false,
+                };
+                err.span_suggestions(
+                    expr.span,
+                    "rewrite this as a decimal floating point literal, or use `as` to turn a hex literal into a float",
+                    [format!("0x{value:X} as {suffix}"), format!("{value}_{suffix}")],
+                    Applicability::MaybeIncorrect,
+                );
+                true
+            }
             _ => false,
         }
     }
 
+    pub(crate) fn suggest_associated_const(
+        &self,
+        err: &mut Diagnostic,
+        expr: &hir::Expr<'_>,
+        expected_ty: Ty<'tcx>,
+    ) -> bool {
+        let Some((DefKind::AssocFn, old_def_id)) = self.typeck_results.borrow().type_dependent_def(expr.hir_id) else {
+            return false;
+        };
+        let old_item_name = self.tcx.item_name(old_def_id);
+        let capitalized_name = Symbol::intern(&old_item_name.as_str().to_uppercase());
+        if old_item_name == capitalized_name {
+            return false;
+        }
+        let (item, segment) = match expr.kind {
+            hir::ExprKind::Path(QPath::Resolved(
+                Some(ty),
+                hir::Path { segments: [segment], .. },
+            ))
+            | hir::ExprKind::Path(QPath::TypeRelative(ty, segment)) => {
+                let self_ty = self.astconv().ast_ty_to_ty(ty);
+                if let Ok(pick) = self.probe_for_name(
+                    Mode::Path,
+                    Ident::new(capitalized_name, segment.ident.span),
+                    Some(expected_ty),
+                    IsSuggestion(true),
+                    self_ty,
+                    expr.hir_id,
+                    ProbeScope::TraitsInScope,
+                ) {
+                    (pick.item, segment)
+                } else {
+                    return false;
+                }
+            }
+            hir::ExprKind::Path(QPath::Resolved(
+                None,
+                hir::Path { segments: [.., segment], .. },
+            )) => {
+                // we resolved through some path that doesn't end in the item name,
+                // better not do a bad suggestion by accident.
+                if old_item_name != segment.ident.name {
+                    return false;
+                }
+                if let Some(item) = self
+                    .tcx
+                    .associated_items(self.tcx.parent(old_def_id))
+                    .filter_by_name_unhygienic(capitalized_name)
+                    .next()
+                {
+                    (*item, segment)
+                } else {
+                    return false;
+                }
+            }
+            _ => return false,
+        };
+        if item.def_id == old_def_id || self.tcx.def_kind(item.def_id) != DefKind::AssocConst {
+            // Same item
+            return false;
+        }
+        let item_ty = self.tcx.type_of(item.def_id);
+        // FIXME(compiler-errors): This check is *so* rudimentary
+        if item_ty.needs_subst() {
+            return false;
+        }
+        if self.can_coerce(item_ty, expected_ty) {
+            err.span_suggestion_verbose(
+                segment.ident.span,
+                format!("try referring to the associated const `{capitalized_name}` instead",),
+                capitalized_name,
+                Applicability::MachineApplicable,
+            );
+            true
+        } else {
+            false
+        }
+    }
+
     fn is_loop(&self, id: hir::HirId) -> bool {
         let node = self.tcx.hir().get(id);
         matches!(node, Node::Expr(Expr { kind: ExprKind::Loop(..), .. }))
@@ -1276,18 +1355,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             && !results.expr_adjustments(callee_expr).iter().any(|adj| matches!(adj.kind, ty::adjustment::Adjust::Deref(..)))
             // Check that we're in fact trying to clone into the expected type
             && self.can_coerce(*pointee_ty, expected_ty)
+            && let trait_ref = ty::Binder::dummy(self.tcx.mk_trait_ref(clone_trait_did, [expected_ty]))
             // And the expected type doesn't implement `Clone`
-            && !self.predicate_must_hold_considering_regions(&traits::Obligation {
-                cause: traits::ObligationCause::dummy(),
-                param_env: self.param_env,
-                recursion_depth: 0,
-                predicate: ty::Binder::dummy(ty::TraitRef {
-                    def_id: clone_trait_did,
-                    substs: self.tcx.mk_substs([expected_ty.into()].iter()),
-                })
-                .without_const()
-                .to_predicate(self.tcx),
-            })
+            && !self.predicate_must_hold_considering_regions(&traits::Obligation::new(
+                self.tcx,
+                traits::ObligationCause::dummy(),
+                self.param_env,
+                trait_ref,
+            ))
         {
             diag.span_note(
                 callee_expr.span,
@@ -1295,6 +1370,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     "`{expected_ty}` does not implement `Clone`, so `{found_ty}` was cloned instead"
                 ),
             );
+            let owner = self.tcx.hir().enclosing_body_owner(expr.hir_id);
+            if let ty::Param(param) = expected_ty.kind()
+                && let Some(generics) = self.tcx.hir().get_generics(owner)
+            {
+                suggest_constraining_type_params(
+                    self.tcx,
+                    generics,
+                    diag,
+                    vec![(param.name.as_str(), "Clone", Some(clone_trait_did))].into_iter(),
+                );
+            } else {
+                self.suggest_derive(diag, &[(trait_ref.to_predicate(self.tcx), None, None)]);
+            }
         }
     }
 
diff --git a/compiler/rustc_hir_typeck/src/gather_locals.rs b/compiler/rustc_hir_typeck/src/gather_locals.rs
index 9a096f24f..15dd3412c 100644
--- a/compiler/rustc_hir_typeck/src/gather_locals.rs
+++ b/compiler/rustc_hir_typeck/src/gather_locals.rs
@@ -77,7 +77,8 @@ impl<'a, 'tcx> GatherLocalsVisitor<'a, 'tcx> {
             Some(ref ty) => {
                 let o_ty = self.fcx.to_ty(&ty);
 
-                let c_ty = self.fcx.inh.infcx.canonicalize_user_type_annotation(UserType::Ty(o_ty));
+                let c_ty =
+                    self.fcx.inh.infcx.canonicalize_user_type_annotation(UserType::Ty(o_ty.raw));
                 debug!("visit_local: ty.hir_id={:?} o_ty={:?} c_ty={:?}", ty.hir_id, o_ty, c_ty);
                 self.fcx
                     .typeck_results
@@ -85,7 +86,7 @@ impl<'a, 'tcx> GatherLocalsVisitor<'a, 'tcx> {
                     .user_provided_types_mut()
                     .insert(ty.hir_id, c_ty);
 
-                Some(LocalTy { decl_ty: o_ty, revealed_ty: o_ty })
+                Some(LocalTy { decl_ty: o_ty.normalized, revealed_ty: o_ty.normalized })
             }
             None => None,
         };
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs
index fd8ea1ad7..b3dd3031d 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs
@@ -233,6 +233,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> {
             self.tcx()
                 .sess
                 .delay_span_bug(expr.span, format!("could not resolve infer vars in `{ty}`"));
+            return;
         }
         let ty = self.tcx().erase_regions(ty);
         let m = self.tcx().parent_module(expr.hir_id).to_def_id();
@@ -303,8 +304,8 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> {
         let mut reinit = None;
         match expr.kind {
             ExprKind::Assign(lhs, rhs, _) => {
-                self.visit_expr(lhs);
                 self.visit_expr(rhs);
+                self.visit_expr(lhs);
 
                 reinit = Some(lhs);
             }
@@ -432,7 +433,7 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> {
                     self.drop_ranges.add_control_edge(self.expr_index, *target)
                 }),
 
-            ExprKind::Break(destination, ..) => {
+            ExprKind::Break(destination, value) => {
                 // destination either points to an expression or to a block. We use
                 // find_target_expression_from_destination to use the last expression of the block
                 // if destination points to a block.
@@ -442,7 +443,11 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> {
                 // will refer to the end of the block due to the post order traversal.
                 self.find_target_expression_from_destination(destination).map_or((), |target| {
                     self.drop_ranges.add_control_edge_hir_id(self.expr_index, target)
-                })
+                });
+
+                if let Some(value) = value {
+                    self.visit_expr(value);
+                }
             }
 
             ExprKind::Call(f, args) => {
@@ -464,6 +469,12 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> {
 
             ExprKind::AddrOf(..)
             | ExprKind::Array(..)
+            // FIXME(eholk): We probably need special handling for AssignOps. The ScopeTree builder
+            // in region.rs runs both lhs then rhs and rhs then lhs and then sets all yields to be
+            // the latest they show up in either traversal. With the older scope-based
+            // approximation, this was fine, but it's probably not right now. What we probably want
+            // to do instead is still run both orders, but consider anything that showed up as a
+            // yield in either order.
             | ExprKind::AssignOp(..)
             | ExprKind::Binary(..)
             | ExprKind::Block(..)
@@ -501,6 +512,9 @@ impl<'a, 'tcx> Visitor<'tcx> for DropRangeVisitor<'a, 'tcx> {
 
         // Increment expr_count here to match what InteriorVisitor expects.
         self.expr_index = self.expr_index + 1;
+
+        // Save a node mapping to get better CFG visualization
+        self.drop_ranges.add_node_mapping(pat.hir_id, self.expr_index);
     }
 }
 
@@ -520,7 +534,7 @@ impl DropRangesBuilder {
                 }
             });
         }
-        debug!("hir_id_map: {:?}", tracked_value_map);
+        debug!("hir_id_map: {:#?}", tracked_value_map);
         let num_values = tracked_value_map.len();
         Self {
             tracked_value_map,
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs
index c0a0bfe8e..e8d31be79 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_visualize.rs
@@ -2,6 +2,7 @@
 //! flow graph when needed for debugging.
 
 use rustc_graphviz as dot;
+use rustc_hir::{Expr, ExprKind, Node};
 use rustc_middle::ty::TyCtxt;
 
 use super::{DropRangesBuilder, PostOrderId};
@@ -80,10 +81,14 @@ impl<'a> dot::Labeller<'a> for DropRangesGraph<'_, '_> {
                     .post_order_map
                     .iter()
                     .find(|(_hir_id, &post_order_id)| post_order_id == *n)
-                    .map_or("<unknown>".into(), |(hir_id, _)| self
-                        .tcx
-                        .hir()
-                        .node_to_string(*hir_id))
+                    .map_or("<unknown>".into(), |(hir_id, _)| format!(
+                        "{}{}",
+                        self.tcx.hir().node_to_string(*hir_id),
+                        match self.tcx.hir().find(*hir_id) {
+                            Some(Node::Expr(Expr { kind: ExprKind::Yield(..), .. })) => " (yield)",
+                            _ => "",
+                        }
+                    ))
             )
             .into(),
         )
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs
index 2abcadcc9..f7b493bc2 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs
@@ -79,7 +79,7 @@ pub fn compute_drop_ranges<'a, 'tcx>(
 /// result of `foo`. On the other hand, if `place` points to `x` then `f` will
 /// be called both on the `ExprKind::Path` node that represents the expression
 /// as well as the HirId of the local `x` itself.
-fn for_each_consumable<'tcx>(hir: Map<'tcx>, place: TrackedValue, mut f: impl FnMut(TrackedValue)) {
+fn for_each_consumable(hir: Map<'_>, place: TrackedValue, mut f: impl FnMut(TrackedValue)) {
     f(place);
     let node = hir.find(place.hir_id());
     if let Some(Node::Expr(expr)) = node {
@@ -96,15 +96,13 @@ fn for_each_consumable<'tcx>(hir: Map<'tcx>, place: TrackedValue, mut f: impl Fn
 }
 
 rustc_index::newtype_index! {
-    pub struct PostOrderId {
-        DEBUG_FORMAT = "id({})",
-    }
+    #[debug_format = "id({})"]
+    pub struct PostOrderId {}
 }
 
 rustc_index::newtype_index! {
-    pub struct TrackedValueIndex {
-        DEBUG_FORMAT = "hidx({})",
-    }
+    #[debug_format = "hidx({})"]
+    pub struct TrackedValueIndex {}
 }
 
 /// Identifies a value whose drop state we need to track.
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
index bfe95852a..ed3d89031 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
@@ -116,7 +116,7 @@ impl<'tcx> ExprUseDelegate<'tcx> {
         // where the `identity(...)` (the rvalue) produces a return type
         // of `&'rv mut A`, where `'a: 'rv`. We then assign this result to
         // `'y`, resulting in (transitively) `'a: 'y` (i.e., while `y` is in use,
-        // `a` will be considered borrowed).  Other parts of the code will ensure
+        // `a` will be considered borrowed). Other parts of the code will ensure
         // that if `y` is live over a yield, `&'y mut A` appears in the generator
         // state. If `'y` is live, then any sound region analysis must conclude
         // that `'a` is also live. So if this causes a bug, blame some other
@@ -140,7 +140,7 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
         diag_expr_id: HirId,
     ) {
         let hir = self.tcx.hir();
-        let parent = match hir.find_parent_node(place_with_id.hir_id) {
+        let parent = match hir.opt_parent_id(place_with_id.hir_id) {
             Some(parent) => parent,
             None => place_with_id.hir_id,
         };
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs
index 3b1518ff7..7af526053 100644
--- a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs
@@ -71,10 +71,8 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
                                 yield_data.expr_and_pat_count, self.expr_count, source_span
                             );
 
-                            if self.fcx.sess().opts.unstable_opts.drop_tracking
-                                && self
-                                    .drop_ranges
-                                    .is_dropped_at(hir_id, yield_data.expr_and_pat_count)
+                            if self
+                                .is_dropped_at_yield_location(hir_id, yield_data.expr_and_pat_count)
                             {
                                 debug!("value is dropped at yield point; not recording");
                                 return false;
@@ -173,6 +171,18 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
             }
         }
     }
+
+    /// If drop tracking is enabled, consult drop_ranges to see if a value is
+    /// known to be dropped at a yield point and therefore can be omitted from
+    /// the generator witness.
+    fn is_dropped_at_yield_location(&self, value_hir_id: HirId, yield_location: usize) -> bool {
+        // short-circuit if drop tracking is not enabled.
+        if !self.fcx.sess().opts.unstable_opts.drop_tracking {
+            return false;
+        }
+
+        self.drop_ranges.is_dropped_at(value_hir_id, yield_location)
+    }
 }
 
 pub fn resolve_interior<'a, 'tcx>(
@@ -448,7 +458,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InteriorVisitor<'a, 'tcx> {
         // the yield, even if it's not borrowed or referenced after the yield. Ideally this would
         // *only* happen for types with observable drop, not all types which wrap them, but that
         // doesn't match the behavior of MIR borrowck and causes ICEs. See the FIXME comment in
-        // src/test/ui/generator/drop-tracking-parent-expression.rs.
+        // tests/ui/generator/drop-tracking-parent-expression.rs.
         let scope = if self.drop_ranges.is_borrowed_temporary(expr)
             || ty.map_or(true, |ty| {
                 // Avoid ICEs in needs_drop.
@@ -563,7 +573,7 @@ fn check_must_not_suspend_ty<'tcx>(
         }
         ty::Adt(def, _) => check_must_not_suspend_def(fcx.tcx, def.did(), hir_id, data),
         // FIXME: support adding the attribute to TAITs
-        ty::Opaque(def, _) => {
+        ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
             let mut has_emitted = false;
             for &(predicate, _) in fcx.tcx.explicit_item_bounds(def) {
                 // We only look at the `DefId`, so it is safe to skip the binder here.
@@ -607,10 +617,7 @@ fn check_must_not_suspend_ty<'tcx>(
         ty::Tuple(fields) => {
             let mut has_emitted = false;
             let comps = match data.expr.map(|e| &e.kind) {
-                Some(hir::ExprKind::Tup(comps)) => {
-                    debug_assert_eq!(comps.len(), fields.len());
-                    Some(comps)
-                }
+                Some(hir::ExprKind::Tup(comps)) if comps.len() == fields.len() => Some(comps),
                 _ => None,
             };
             for (i, ty) in fields.iter().enumerate() {
diff --git a/compiler/rustc_hir_typeck/src/intrinsicck.rs b/compiler/rustc_hir_typeck/src/intrinsicck.rs
index c2dc14024..3c873024c 100644
--- a/compiler/rustc_hir_typeck/src/intrinsicck.rs
+++ b/compiler/rustc_hir_typeck/src/intrinsicck.rs
@@ -105,6 +105,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else {
             err.note(&format!("source type: `{}` ({})", from, skeleton_string(from, sk_from)))
                 .note(&format!("target type: `{}` ({})", to, skeleton_string(to, sk_to)));
+            let mut should_delay_as_bug = false;
+            if let Err(LayoutError::Unknown(bad_from)) = sk_from && bad_from.references_error() {
+                should_delay_as_bug = true;
+            }
+            if let Err(LayoutError::Unknown(bad_to)) = sk_to && bad_to.references_error() {
+                should_delay_as_bug = true;
+            }
+            if should_delay_as_bug {
+                err.delay_as_bug();
+            }
         }
         err.emit();
     }
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 5b2352cda..7ddf9eaa4 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -205,7 +205,7 @@ fn typeck_with_fallback<'tcx>(
 
         if let Some(hir::FnSig { header, decl, .. }) = fn_sig {
             let fn_sig = if rustc_hir_analysis::collect::get_infer_ret_ty(&decl.output).is_some() {
-                <dyn AstConv<'_>>::ty_of_fn(&fcx, id, header.unsafety, header.abi, decl, None, None)
+                fcx.astconv().ty_of_fn(id, header.unsafety, header.abi, decl, None, None)
             } else {
                 tcx.fn_sig(def_id)
             };
@@ -220,11 +220,11 @@ fn typeck_with_fallback<'tcx>(
         } else {
             let expected_type = body_ty
                 .and_then(|ty| match ty.kind {
-                    hir::TyKind::Infer => Some(<dyn AstConv<'_>>::ast_ty_to_ty(&fcx, ty)),
+                    hir::TyKind::Infer => Some(fcx.astconv().ast_ty_to_ty(ty)),
                     _ => None,
                 })
                 .unwrap_or_else(|| match tcx.hir().get(id) {
-                    Node::AnonConst(_) => match tcx.hir().get(tcx.hir().get_parent_node(id)) {
+                    Node::AnonConst(_) => match tcx.hir().get(tcx.hir().parent_id(id)) {
                         Node::Expr(&hir::Expr {
                             kind: hir::ExprKind::ConstBlock(ref anon_const),
                             ..
@@ -240,10 +240,8 @@ fn typeck_with_fallback<'tcx>(
                         }),
                         Node::Expr(&hir::Expr { kind: hir::ExprKind::InlineAsm(asm), .. })
                         | Node::Item(&hir::Item { kind: hir::ItemKind::GlobalAsm(asm), .. }) => {
-                            let operand_ty = asm
-                                .operands
-                                .iter()
-                                .filter_map(|(op, _op_sp)| match op {
+                            let operand_ty =
+                                asm.operands.iter().find_map(|(op, _op_sp)| match op {
                                     hir::InlineAsmOperand::Const { anon_const }
                                         if anon_const.hir_id == id =>
                                     {
@@ -259,8 +257,7 @@ fn typeck_with_fallback<'tcx>(
                                         }))
                                     }
                                     _ => None,
-                                })
-                                .next();
+                                });
                             operand_ty.unwrap_or_else(fallback)
                         }
                         _ => fallback(),
@@ -300,7 +297,7 @@ fn typeck_with_fallback<'tcx>(
         fcx.resolve_generator_interiors(def_id.to_def_id());
 
         for (ty, span, code) in fcx.deferred_sized_obligations.borrow_mut().drain(..) {
-            let ty = fcx.normalize_ty(span, ty);
+            let ty = fcx.normalize(span, ty);
             fcx.require_type_is_sized(ty, span, code);
         }
 
@@ -462,8 +459,8 @@ fn fatally_break_rust(sess: &Session) {
     ));
 }
 
-fn has_expected_num_generic_args<'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn has_expected_num_generic_args(
+    tcx: TyCtxt<'_>,
     trait_did: Option<DefId>,
     expected: usize,
 ) -> bool {
diff --git a/compiler/rustc_hir_typeck/src/mem_categorization.rs b/compiler/rustc_hir_typeck/src/mem_categorization.rs
index 0b5dc946c..48c75cde9 100644
--- a/compiler/rustc_hir_typeck/src/mem_categorization.rs
+++ b/compiler/rustc_hir_typeck/src/mem_categorization.rs
@@ -736,7 +736,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
             }
 
             PatKind::Box(ref subpat) | PatKind::Ref(ref subpat, _) => {
-                // box p1, &p1, &mut p1.  we can ignore the mutability of
+                // box p1, &p1, &mut p1. we can ignore the mutability of
                 // PatKind::Ref since that information is already contained
                 // in the type.
                 let subplace = self.cat_deref(pat, place_with_id)?;
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index 03d0e7926..372ea30eb 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -4,6 +4,9 @@ use crate::{callee, FnCtxt};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::GenericArg;
+use rustc_hir_analysis::astconv::generics::{
+    check_generic_arg_count_for_call, create_substs_for_generic_args,
+};
 use rustc_hir_analysis::astconv::{AstConv, CreateSubstsForGenericArgsCtxt, IsMethodCall};
 use rustc_infer::infer::{self, InferOk};
 use rustc_middle::traits::{ObligationCauseCode, UnifyReceiverContext};
@@ -12,10 +15,10 @@ use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutabili
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::subst::{self, SubstsRef};
 use rustc_middle::ty::{self, GenericParamDefKind, Ty};
-use rustc_span::Span;
+use rustc_middle::ty::{InternalSubsts, UserSubsts, UserType};
+use rustc_span::{Span, DUMMY_SP};
 use rustc_trait_selection::traits;
 
-use std::iter;
 use std::ops::Deref;
 
 struct ConfirmContext<'a, 'tcx> {
@@ -45,7 +48,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self_expr: &'tcx hir::Expr<'tcx>,
         call_expr: &'tcx hir::Expr<'tcx>,
         unadjusted_self_ty: Ty<'tcx>,
-        pick: probe::Pick<'tcx>,
+        pick: &probe::Pick<'tcx>,
         segment: &hir::PathSegment<'_>,
     ) -> ConfirmResult<'tcx> {
         debug!(
@@ -71,7 +74,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
     fn confirm(
         &mut self,
         unadjusted_self_ty: Ty<'tcx>,
-        pick: probe::Pick<'tcx>,
+        pick: &probe::Pick<'tcx>,
         segment: &hir::PathSegment<'_>,
     ) -> ConfirmResult<'tcx> {
         // Adjust the self expression the user provided and obtain the adjusted type.
@@ -89,7 +92,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
         // If there is a `Self: Sized` bound and `Self` is a trait object, it is possible that
         // something which derefs to `Self` actually implements the trait and the caller
         // wanted to make a static dispatch on it but forgot to import the trait.
-        // See test `src/test/ui/issue-35976.rs`.
+        // See test `tests/ui/issue-35976.rs`.
         //
         // In that case, we'll error anyway, but we'll also re-run the search with all traits
         // in scope, and if we find another method which can be used, we'll output an
@@ -97,7 +100,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
         let filler_substs = rcvr_substs
             .extend_to(self.tcx, pick.item.def_id, |def, _| self.tcx.mk_param_from_def(def));
         let illegal_sized_bound = self.predicates_require_illegal_sized_bound(
-            &self.tcx.predicates_of(pick.item.def_id).instantiate(self.tcx, filler_substs),
+            self.tcx.predicates_of(pick.item.def_id).instantiate(self.tcx, filler_substs),
         );
 
         // Unify the (adjusted) self type with what the method expects.
@@ -330,7 +333,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
         // variables.
         let generics = self.tcx.generics_of(pick.item.def_id);
 
-        let arg_count_correct = <dyn AstConv<'_>>::check_generic_arg_count_for_call(
+        let arg_count_correct = check_generic_arg_count_for_call(
             self.tcx,
             self.span,
             pick.item.def_id,
@@ -368,11 +371,10 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
             ) -> subst::GenericArg<'tcx> {
                 match (&param.kind, arg) {
                     (GenericParamDefKind::Lifetime, GenericArg::Lifetime(lt)) => {
-                        <dyn AstConv<'_>>::ast_region_to_region(self.cfcx.fcx, lt, Some(param))
-                            .into()
+                        self.cfcx.fcx.astconv().ast_region_to_region(lt, Some(param)).into()
                     }
                     (GenericParamDefKind::Type { .. }, GenericArg::Type(ty)) => {
-                        self.cfcx.to_ty(ty).into()
+                        self.cfcx.to_ty(ty).raw.into()
                     }
                     (GenericParamDefKind::Const { .. }, GenericArg::Const(ct)) => {
                         self.cfcx.const_arg_to_const(&ct.value, param.def_id).into()
@@ -397,7 +399,8 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
                 self.cfcx.var_for_def(self.cfcx.span, param)
             }
         }
-        <dyn AstConv<'_>>::create_substs_for_generic_args(
+
+        let substs = create_substs_for_generic_args(
             self.tcx,
             pick.item.def_id,
             parent_substs,
@@ -405,7 +408,47 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
             None,
             &arg_count_correct,
             &mut MethodSubstsCtxt { cfcx: self, pick, seg },
-        )
+        );
+
+        // When the method is confirmed, the `substs` includes
+        // parameters from not just the method, but also the impl of
+        // the method -- in particular, the `Self` type will be fully
+        // resolved. However, those are not something that the "user
+        // specified" -- i.e., those types come from the inferred type
+        // of the receiver, not something the user wrote. So when we
+        // create the user-substs, we want to replace those earlier
+        // types with just the types that the user actually wrote --
+        // that is, those that appear on the *method itself*.
+        //
+        // As an example, if the user wrote something like
+        // `foo.bar::<u32>(...)` -- the `Self` type here will be the
+        // type of `foo` (possibly adjusted), but we don't want to
+        // include that. We want just the `[_, u32]` part.
+        if !substs.is_empty() && !generics.params.is_empty() {
+            let user_type_annotation = self.probe(|_| {
+                let user_substs = UserSubsts {
+                    substs: InternalSubsts::for_item(self.tcx, pick.item.def_id, |param, _| {
+                        let i = param.index as usize;
+                        if i < generics.parent_count {
+                            self.fcx.var_for_def(DUMMY_SP, param)
+                        } else {
+                            substs[i]
+                        }
+                    }),
+                    user_self_ty: None, // not relevant here
+                };
+
+                self.fcx.canonicalize_user_type_annotation(UserType::TypeOf(
+                    pick.item.def_id,
+                    user_substs,
+                ))
+            });
+
+            debug!("instantiate_method_substs: user_type_annotation={:?}", user_type_annotation);
+            self.fcx.write_user_type_annotation(self.call_expr.hir_id, user_type_annotation);
+        }
+
+        self.normalize(self.span, substs)
     }
 
     fn unify_receivers(
@@ -521,7 +564,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
 
     fn predicates_require_illegal_sized_bound(
         &self,
-        predicates: &ty::InstantiatedPredicates<'tcx>,
+        predicates: ty::InstantiatedPredicates<'tcx>,
     ) -> Option<Span> {
         let sized_def_id = self.tcx.lang_items().sized_trait()?;
 
@@ -531,10 +574,11 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
                 ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred))
                     if trait_pred.def_id() == sized_def_id =>
                 {
-                    let span = iter::zip(&predicates.predicates, &predicates.spans)
+                    let span = predicates
+                        .iter()
                         .find_map(
                             |(p, span)| {
-                                if *p == obligation.predicate { Some(*span) } else { None }
+                                if p == obligation.predicate { Some(span) } else { None }
                             },
                         )
                         .unwrap_or(rustc_span::DUMMY_SP);
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs
index a2ca5c3b7..b810a967a 100644
--- a/compiler/rustc_hir_typeck/src/method/mod.rs
+++ b/compiler/rustc_hir_typeck/src/method/mod.rs
@@ -11,7 +11,7 @@ pub use self::suggest::SelfSource;
 pub use self::MethodError::*;
 
 use crate::errors::OpMethodGenericParams;
-use crate::{Expectation, FnCtxt};
+use crate::FnCtxt;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, Diagnostic};
 use rustc_hir as hir;
@@ -57,7 +57,12 @@ pub enum MethodError<'tcx> {
     PrivateMatch(DefKind, DefId, Vec<DefId>),
 
     // Found a `Self: Sized` bound where `Self` is a trait object.
-    IllegalSizedBound(Vec<DefId>, bool, Span),
+    IllegalSizedBound {
+        candidates: Vec<DefId>,
+        needs_mut: bool,
+        bound_span: Span,
+        self_expr: &'tcx hir::Expr<'tcx>,
+    },
 
     // Found a match, but the return type is wrong
     BadReturnType,
@@ -92,10 +97,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self_ty: Ty<'tcx>,
         call_expr_id: hir::HirId,
         allow_private: bool,
+        return_type: Option<Ty<'tcx>>,
     ) -> bool {
         match self.probe_for_name(
             probe::Mode::MethodCall,
             method_name,
+            return_type,
             IsSuggestion(false),
             self_ty,
             call_expr_id,
@@ -112,8 +119,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             Err(NoMatch(..)) => false,
             Err(Ambiguity(..)) => true,
             Err(PrivateMatch(..)) => allow_private,
-            Err(IllegalSizedBound(..)) => true,
-            Err(BadReturnType) => bug!("no return type expectations but got BadReturnType"),
+            Err(IllegalSizedBound { .. }) => true,
+            Err(BadReturnType) => false,
         }
     }
 
@@ -125,17 +132,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         msg: &str,
         method_name: Ident,
         self_ty: Ty<'tcx>,
-        call_expr: &hir::Expr<'_>,
+        call_expr: &hir::Expr<'tcx>,
         span: Option<Span>,
     ) {
         let params = self
-            .probe_for_name(
-                probe::Mode::MethodCall,
+            .lookup_probe_for_diagnostic(
                 method_name,
-                IsSuggestion(true),
                 self_ty,
-                call_expr.hir_id,
+                call_expr,
                 ProbeScope::TraitsInScope,
+                None,
             )
             .map(|pick| {
                 let sig = self.tcx.fn_sig(pick.item.def_id);
@@ -192,8 +198,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         self.tcx.check_stability(pick.item.def_id, Some(call_expr.hir_id), span, None);
 
-        let result =
-            self.confirm_method(span, self_expr, call_expr, self_ty, pick.clone(), segment);
+        let result = self.confirm_method(span, self_expr, call_expr, self_ty, &pick, segment);
         debug!("result = {:?}", result);
 
         if let Some(span) = result.illegal_sized_bound {
@@ -210,34 +215,39 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     ProbeScope::TraitsInScope,
                 ) {
                     Ok(ref new_pick) if pick.differs_from(new_pick) => {
-                        needs_mut = true;
+                        needs_mut = new_pick.self_ty.ref_mutability() != self_ty.ref_mutability();
                     }
                     _ => {}
                 }
             }
 
             // We probe again, taking all traits into account (not only those in scope).
-            let candidates =
-                match self.lookup_probe(segment.ident, self_ty, call_expr, ProbeScope::AllTraits) {
-                    // If we find a different result the caller probably forgot to import a trait.
-                    Ok(ref new_pick) if pick.differs_from(new_pick) => {
-                        vec![new_pick.item.container_id(self.tcx)]
-                    }
-                    Err(Ambiguity(ref sources)) => sources
-                        .iter()
-                        .filter_map(|source| {
-                            match *source {
-                                // Note: this cannot come from an inherent impl,
-                                // because the first probing succeeded.
-                                CandidateSource::Impl(def) => self.tcx.trait_id_of_impl(def),
-                                CandidateSource::Trait(_) => None,
-                            }
-                        })
-                        .collect(),
-                    _ => Vec::new(),
-                };
-
-            return Err(IllegalSizedBound(candidates, needs_mut, span));
+            let candidates = match self.lookup_probe_for_diagnostic(
+                segment.ident,
+                self_ty,
+                call_expr,
+                ProbeScope::AllTraits,
+                None,
+            ) {
+                // If we find a different result the caller probably forgot to import a trait.
+                Ok(ref new_pick) if pick.differs_from(new_pick) => {
+                    vec![new_pick.item.container_id(self.tcx)]
+                }
+                Err(Ambiguity(ref sources)) => sources
+                    .iter()
+                    .filter_map(|source| {
+                        match *source {
+                            // Note: this cannot come from an inherent impl,
+                            // because the first probing succeeded.
+                            CandidateSource::Impl(def) => self.tcx.trait_id_of_impl(def),
+                            CandidateSource::Trait(_) => None,
+                        }
+                    })
+                    .collect(),
+                _ => Vec::new(),
+            };
+
+            return Err(IllegalSizedBound { candidates, needs_mut, bound_span: span, self_expr });
         }
 
         Ok(result.callee)
@@ -248,12 +258,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         method_name: Ident,
         self_ty: Ty<'tcx>,
-        call_expr: &'tcx hir::Expr<'tcx>,
+        call_expr: &hir::Expr<'_>,
         scope: ProbeScope,
     ) -> probe::PickResult<'tcx> {
         let pick = self.probe_for_name(
             probe::Mode::MethodCall,
             method_name,
+            None,
             IsSuggestion(false),
             self_ty,
             call_expr.hir_id,
@@ -263,53 +274,32 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         Ok(pick)
     }
 
-    pub(super) fn obligation_for_method(
+    pub fn lookup_probe_for_diagnostic(
         &self,
-        span: Span,
-        trait_def_id: DefId,
+        method_name: Ident,
         self_ty: Ty<'tcx>,
-        opt_input_types: Option<&[Ty<'tcx>]>,
-    ) -> (traits::Obligation<'tcx, ty::Predicate<'tcx>>, &'tcx ty::List<ty::subst::GenericArg<'tcx>>)
-    {
-        // Construct a trait-reference `self_ty : Trait<input_tys>`
-        let substs = InternalSubsts::for_item(self.tcx, trait_def_id, |param, _| {
-            match param.kind {
-                GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => {}
-                GenericParamDefKind::Type { .. } => {
-                    if param.index == 0 {
-                        return self_ty.into();
-                    } else if let Some(input_types) = opt_input_types {
-                        return input_types[param.index as usize - 1].into();
-                    }
-                }
-            }
-            self.var_for_def(span, param)
-        });
-
-        let trait_ref = ty::TraitRef::new(trait_def_id, substs);
-
-        // Construct an obligation
-        let poly_trait_ref = ty::Binder::dummy(trait_ref);
-        (
-            traits::Obligation::misc(
-                self.tcx,
-                span,
-                self.body_id,
-                self.param_env,
-                poly_trait_ref.without_const(),
-            ),
-            substs,
-        )
+        call_expr: &hir::Expr<'_>,
+        scope: ProbeScope,
+        return_type: Option<Ty<'tcx>>,
+    ) -> probe::PickResult<'tcx> {
+        let pick = self.probe_for_name(
+            probe::Mode::MethodCall,
+            method_name,
+            return_type,
+            IsSuggestion(true),
+            self_ty,
+            call_expr.hir_id,
+            scope,
+        )?;
+        Ok(pick)
     }
 
-    pub(super) fn obligation_for_op_method(
+    pub(super) fn obligation_for_method(
         &self,
-        span: Span,
+        cause: ObligationCause<'tcx>,
         trait_def_id: DefId,
         self_ty: Ty<'tcx>,
-        opt_input_type: Option<Ty<'tcx>>,
-        opt_input_expr: Option<&'tcx hir::Expr<'tcx>>,
-        expected: Expectation<'tcx>,
+        opt_input_types: Option<&[Ty<'tcx>]>,
     ) -> (traits::Obligation<'tcx, ty::Predicate<'tcx>>, &'tcx ty::List<ty::subst::GenericArg<'tcx>>)
     {
         // Construct a trait-reference `self_ty : Trait<input_tys>`
@@ -319,35 +309,24 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 GenericParamDefKind::Type { .. } => {
                     if param.index == 0 {
                         return self_ty.into();
-                    } else if let Some(input_type) = opt_input_type {
-                        return input_type.into();
+                    } else if let Some(input_types) = opt_input_types {
+                        return input_types[param.index as usize - 1].into();
                     }
                 }
             }
-            self.var_for_def(span, param)
+            self.var_for_def(cause.span, param)
         });
 
-        let trait_ref = ty::TraitRef::new(trait_def_id, substs);
+        let trait_ref = self.tcx.mk_trait_ref(trait_def_id, substs);
 
         // Construct an obligation
         let poly_trait_ref = ty::Binder::dummy(trait_ref);
-        let output_ty = expected.only_has_type(self).and_then(|ty| (!ty.needs_infer()).then(|| ty));
-
         (
             traits::Obligation::new(
                 self.tcx,
-                traits::ObligationCause::new(
-                    span,
-                    self.body_id,
-                    traits::BinOp {
-                        rhs_span: opt_input_expr.map(|expr| expr.span),
-                        is_lit: opt_input_expr
-                            .map_or(false, |expr| matches!(expr.kind, hir::ExprKind::Lit(_))),
-                        output_ty,
-                    },
-                ),
+                cause,
                 self.param_env,
-                poly_trait_ref,
+                poly_trait_ref.without_const(),
             ),
             substs,
         )
@@ -358,55 +337,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// In particular, it doesn't really do any probing: it simply constructs
     /// an obligation for a particular trait with the given self type and checks
     /// whether that trait is implemented.
-    #[instrument(level = "debug", skip(self, span))]
+    #[instrument(level = "debug", skip(self))]
     pub(super) fn lookup_method_in_trait(
         &self,
-        span: Span,
+        cause: ObligationCause<'tcx>,
         m_name: Ident,
         trait_def_id: DefId,
         self_ty: Ty<'tcx>,
         opt_input_types: Option<&[Ty<'tcx>]>,
     ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> {
         let (obligation, substs) =
-            self.obligation_for_method(span, trait_def_id, self_ty, opt_input_types);
-        self.construct_obligation_for_trait(
-            span,
-            m_name,
-            trait_def_id,
-            obligation,
-            substs,
-            None,
-            false,
-        )
-    }
-
-    pub(super) fn lookup_op_method_in_trait(
-        &self,
-        span: Span,
-        m_name: Ident,
-        trait_def_id: DefId,
-        self_ty: Ty<'tcx>,
-        opt_input_type: Option<Ty<'tcx>>,
-        opt_input_expr: Option<&'tcx hir::Expr<'tcx>>,
-        expected: Expectation<'tcx>,
-    ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> {
-        let (obligation, substs) = self.obligation_for_op_method(
-            span,
-            trait_def_id,
-            self_ty,
-            opt_input_type,
-            opt_input_expr,
-            expected,
-        );
-        self.construct_obligation_for_trait(
-            span,
-            m_name,
-            trait_def_id,
-            obligation,
-            substs,
-            opt_input_expr,
-            true,
-        )
+            self.obligation_for_method(cause, trait_def_id, self_ty, opt_input_types);
+        self.construct_obligation_for_trait(m_name, trait_def_id, obligation, substs)
     }
 
     // FIXME(#18741): it seems likely that we can consolidate some of this
@@ -414,13 +356,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     // of this method is basically the same as confirmation.
     fn construct_obligation_for_trait(
         &self,
-        span: Span,
         m_name: Ident,
         trait_def_id: DefId,
         obligation: traits::PredicateObligation<'tcx>,
         substs: &'tcx ty::List<ty::subst::GenericArg<'tcx>>,
-        opt_input_expr: Option<&'tcx hir::Expr<'tcx>>,
-        is_op: bool,
     ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> {
         debug!(?obligation);
 
@@ -436,7 +375,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let tcx = self.tcx;
         let Some(method_item) = self.associated_value(trait_def_id, m_name) else {
             tcx.sess.delay_span_bug(
-                span,
+                obligation.cause.span,
                 "operator trait does not have corresponding operator method",
             );
             return None;
@@ -457,29 +396,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Instantiate late-bound regions and substitute the trait
         // parameters into the method type to get the actual method type.
         //
-        // N.B., instantiate late-bound regions first so that
-        // `instantiate_type_scheme` can normalize associated types that
-        // may reference those regions.
+        // N.B., instantiate late-bound regions before normalizing the
+        // function signature so that normalization does not need to deal
+        // with bound regions.
         let fn_sig = tcx.bound_fn_sig(def_id);
         let fn_sig = fn_sig.subst(self.tcx, substs);
-        let fn_sig = self.replace_bound_vars_with_fresh_vars(span, infer::FnCall, fn_sig);
-
-        let cause = if is_op {
-            ObligationCause::new(
-                span,
-                self.body_id,
-                traits::BinOp {
-                    rhs_span: opt_input_expr.map(|expr| expr.span),
-                    is_lit: opt_input_expr
-                        .map_or(false, |expr| matches!(expr.kind, hir::ExprKind::Lit(_))),
-                    output_ty: None,
-                },
-            )
-        } else {
-            traits::ObligationCause::misc(span, self.body_id)
-        };
+        let fn_sig =
+            self.replace_bound_vars_with_fresh_vars(obligation.cause.span, infer::FnCall, fn_sig);
 
-        let InferOk { value, obligations: o } = self.at(&cause, self.param_env).normalize(fn_sig);
+        let InferOk { value, obligations: o } =
+            self.at(&obligation.cause, self.param_env).normalize(fn_sig);
         let fn_sig = {
             obligations.extend(o);
             value
@@ -487,7 +413,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // Register obligations for the parameters. This will include the
         // `Self` parameter, which in turn has a bound of the main trait,
-        // so this also effectively registers `obligation` as well.  (We
+        // so this also effectively registers `obligation` as well. (We
         // used to register `obligation` explicitly, but that resulted in
         // double error messages being reported.)
         //
@@ -495,7 +421,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // any late-bound regions appearing in its bounds.
         let bounds = self.tcx.predicates_of(def_id).instantiate(self.tcx, substs);
 
-        let InferOk { value, obligations: o } = self.at(&cause, self.param_env).normalize(bounds);
+        let InferOk { value, obligations: o } =
+            self.at(&obligation.cause, self.param_env).normalize(bounds);
         let bounds = {
             obligations.extend(o);
             value
@@ -503,7 +430,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         assert!(!bounds.has_escaping_bound_vars());
 
-        let predicates_cause = cause.clone();
+        let predicates_cause = obligation.cause.clone();
         obligations.extend(traits::predicates_for_generics(
             move |_, _| predicates_cause.clone(),
             self.param_env,
@@ -518,7 +445,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
         obligations.push(traits::Obligation::new(
             tcx,
-            cause,
+            obligation.cause,
             self.param_env,
             ty::Binder::dummy(ty::PredicateKind::WellFormed(method_ty.into())),
         ));
@@ -584,6 +511,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let pick = self.probe_for_name(
             probe::Mode::Path,
             method_name,
+            None,
             IsSuggestion(false),
             self_ty,
             expr_id,
diff --git a/compiler/rustc_hir_typeck/src/method/prelude2021.rs b/compiler/rustc_hir_typeck/src/method/prelude2021.rs
index dea14dd93..3d6c2119b 100644
--- a/compiler/rustc_hir_typeck/src/method/prelude2021.rs
+++ b/compiler/rustc_hir_typeck/src/method/prelude2021.rs
@@ -341,8 +341,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Find an identifier with which this trait was imported (note that `_` doesn't count).
         let any_id = import_items
             .iter()
-            .filter_map(|item| if item.ident.name != Underscore { Some(item.ident) } else { None })
-            .next();
+            .find_map(|item| if item.ident.name != Underscore { Some(item.ident) } else { None });
         if let Some(any_id) = any_id {
             if any_id.name == Empty {
                 // Glob import, so just use its name.
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index ae299cc9d..a24814313 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -9,6 +9,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
+use rustc_hir_analysis::autoderef::{self, Autoderef};
 use rustc_infer::infer::canonical::OriginalQueryValues;
 use rustc_infer::infer::canonical::{Canonical, QueryResponse};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
@@ -29,7 +30,6 @@ use rustc_span::lev_distance::{
 };
 use rustc_span::symbol::sym;
 use rustc_span::{symbol::Ident, Span, Symbol, DUMMY_SP};
-use rustc_trait_selection::autoderef::{self, Autoderef};
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
 use rustc_trait_selection::traits::query::method_autoderef::MethodAutoderefBadTy;
 use rustc_trait_selection::traits::query::method_autoderef::{
@@ -38,9 +38,9 @@ use rustc_trait_selection::traits::query::method_autoderef::{
 use rustc_trait_selection::traits::query::CanonicalTyGoal;
 use rustc_trait_selection::traits::NormalizeExt;
 use rustc_trait_selection::traits::{self, ObligationCause};
+use std::cell::RefCell;
 use std::cmp::max;
 use std::iter;
-use std::mem;
 use std::ops::Deref;
 
 use smallvec::{smallvec, SmallVec};
@@ -62,28 +62,29 @@ struct ProbeContext<'a, 'tcx> {
 
     /// This is the OriginalQueryValues for the steps queries
     /// that are answered in steps.
-    orig_steps_var_values: OriginalQueryValues<'tcx>,
+    orig_steps_var_values: &'a OriginalQueryValues<'tcx>,
     steps: &'tcx [CandidateStep<'tcx>],
 
     inherent_candidates: Vec<Candidate<'tcx>>,
     extension_candidates: Vec<Candidate<'tcx>>,
     impl_dups: FxHashSet<DefId>,
 
-    /// Collects near misses when the candidate functions are missing a `self` keyword and is only
-    /// used for error reporting
-    static_candidates: Vec<CandidateSource>,
-
     /// When probing for names, include names that are close to the
-    /// requested name (by Levensthein distance)
+    /// requested name (by Levenshtein distance)
     allow_similar_names: bool,
 
     /// Some(candidate) if there is a private candidate
     private_candidate: Option<(DefKind, DefId)>,
 
+    /// Collects near misses when the candidate functions are missing a `self` keyword and is only
+    /// used for error reporting
+    static_candidates: RefCell<Vec<CandidateSource>>,
+
     /// Collects near misses when trait bounds for type parameters are unsatisfied and is only used
     /// for error reporting
-    unsatisfied_predicates:
+    unsatisfied_predicates: RefCell<
         Vec<(ty::Predicate<'tcx>, Option<ty::Predicate<'tcx>>, Option<ObligationCause<'tcx>>)>,
+    >,
 
     scope_expr_id: hir::HirId,
 }
@@ -96,7 +97,7 @@ impl<'a, 'tcx> Deref for ProbeContext<'a, 'tcx> {
 }
 
 #[derive(Debug, Clone)]
-struct Candidate<'tcx> {
+pub(crate) struct Candidate<'tcx> {
     // Candidates are (I'm not quite sure, but they are mostly) basically
     // some metadata on top of a `ty::AssocItem` (without substs).
     //
@@ -130,13 +131,13 @@ struct Candidate<'tcx> {
     // if `T: Sized`.
     xform_self_ty: Ty<'tcx>,
     xform_ret_ty: Option<Ty<'tcx>>,
-    item: ty::AssocItem,
-    kind: CandidateKind<'tcx>,
-    import_ids: SmallVec<[LocalDefId; 1]>,
+    pub(crate) item: ty::AssocItem,
+    pub(crate) kind: CandidateKind<'tcx>,
+    pub(crate) import_ids: SmallVec<[LocalDefId; 1]>,
 }
 
 #[derive(Debug, Clone)]
-enum CandidateKind<'tcx> {
+pub(crate) enum CandidateKind<'tcx> {
     InherentImplCandidate(
         SubstsRef<'tcx>,
         // Normalize obligations
@@ -231,7 +232,7 @@ pub type PickResult<'tcx> = Result<Pick<'tcx>, MethodError<'tcx>>;
 pub enum Mode {
     // An expression of the form `receiver.method_name(...)`.
     // Autoderefs are performed on `receiver`, lookup is done based on the
-    // `self` argument  of the method, and static methods aren't considered.
+    // `self` argument of the method, and static methods aren't considered.
     MethodCall,
     // An expression of the form `Type::item` or `<T>::item`.
     // No autoderefs are performed, lookup is done based on the type each
@@ -303,6 +304,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         mode: Mode,
         item_name: Ident,
+        return_type: Option<Ty<'tcx>>,
         is_suggestion: IsSuggestion,
         self_ty: Ty<'tcx>,
         scope_expr_id: hir::HirId,
@@ -312,7 +314,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             item_name.span,
             mode,
             Some(item_name),
-            None,
+            return_type,
             is_suggestion,
             self_ty,
             scope_expr_id,
@@ -321,6 +323,37 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         )
     }
 
+    #[instrument(level = "debug", skip(self))]
+    pub(crate) fn probe_for_name_many(
+        &self,
+        mode: Mode,
+        item_name: Ident,
+        return_type: Option<Ty<'tcx>>,
+        is_suggestion: IsSuggestion,
+        self_ty: Ty<'tcx>,
+        scope_expr_id: hir::HirId,
+        scope: ProbeScope,
+    ) -> Vec<Candidate<'tcx>> {
+        self.probe_op(
+            item_name.span,
+            mode,
+            Some(item_name),
+            return_type,
+            is_suggestion,
+            self_ty,
+            scope_expr_id,
+            scope,
+            |probe_cx| {
+                Ok(probe_cx
+                    .inherent_candidates
+                    .into_iter()
+                    .chain(probe_cx.extension_candidates)
+                    .collect())
+            },
+        )
+        .unwrap()
+    }
+
     fn probe_op<OP, R>(
         &'a self,
         span: Span,
@@ -334,7 +367,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         op: OP,
     ) -> Result<R, MethodError<'tcx>>
     where
-        OP: FnOnce(ProbeContext<'a, 'tcx>) -> Result<R, MethodError<'tcx>>,
+        OP: FnOnce(ProbeContext<'_, 'tcx>) -> Result<R, MethodError<'tcx>>,
     {
         let mut orig_values = OriginalQueryValues::default();
         let param_env_and_self_ty = self.canonicalize_query(
@@ -445,7 +478,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 mode,
                 method_name,
                 return_type,
-                orig_values,
+                &orig_values,
                 steps.steps,
                 scope_expr_id,
             );
@@ -453,7 +486,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             probe_cx.assemble_inherent_candidates();
             match scope {
                 ProbeScope::TraitsInScope => {
-                    probe_cx.assemble_extension_candidates_for_traits_in_scope(scope_expr_id)
+                    probe_cx.assemble_extension_candidates_for_traits_in_scope()
                 }
                 ProbeScope::AllTraits => probe_cx.assemble_extension_candidates_for_all_traits(),
             };
@@ -539,7 +572,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         mode: Mode,
         method_name: Option<Ident>,
         return_type: Option<Ty<'tcx>>,
-        orig_steps_var_values: OriginalQueryValues<'tcx>,
+        orig_steps_var_values: &'a OriginalQueryValues<'tcx>,
         steps: &'tcx [CandidateStep<'tcx>],
         scope_expr_id: hir::HirId,
     ) -> ProbeContext<'a, 'tcx> {
@@ -554,10 +587,10 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             impl_dups: FxHashSet::default(),
             orig_steps_var_values,
             steps,
-            static_candidates: Vec::new(),
             allow_similar_names: false,
             private_candidate: None,
-            unsatisfied_predicates: Vec::new(),
+            static_candidates: RefCell::new(Vec::new()),
+            unsatisfied_predicates: RefCell::new(Vec::new()),
             scope_expr_id,
         }
     }
@@ -566,8 +599,9 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         self.inherent_candidates.clear();
         self.extension_candidates.clear();
         self.impl_dups.clear();
-        self.static_candidates.clear();
         self.private_candidate = None;
+        self.static_candidates.borrow_mut().clear();
+        self.unsatisfied_predicates.borrow_mut().clear();
     }
 
     ///////////////////////////////////////////////////////////////////////////
@@ -855,9 +889,9 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         }
     }
 
-    fn assemble_extension_candidates_for_traits_in_scope(&mut self, expr_hir_id: hir::HirId) {
+    fn assemble_extension_candidates_for_traits_in_scope(&mut self) {
         let mut duplicates = FxHashSet::default();
-        let opt_applicable_traits = self.tcx.in_scope_traits(expr_hir_id);
+        let opt_applicable_traits = self.tcx.in_scope_traits(self.scope_expr_id);
         if let Some(applicable_traits) = opt_applicable_traits {
             for trait_candidate in applicable_traits.iter() {
                 let trait_did = trait_candidate.def_id;
@@ -918,7 +952,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     ) {
         debug!("assemble_extension_candidates_for_trait(trait_def_id={:?})", trait_def_id);
         let trait_substs = self.fresh_item_substs(trait_def_id);
-        let trait_ref = ty::TraitRef::new(trait_def_id, trait_substs);
+        let trait_ref = self.tcx.mk_trait_ref(trait_def_id, trait_substs);
 
         if self.tcx.is_trait_alias(trait_def_id) {
             // For trait aliases, assume all supertraits are relevant.
@@ -941,6 +975,9 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             });
         } else {
             debug_assert!(self.tcx.is_trait(trait_def_id));
+            if self.tcx.trait_is_auto(trait_def_id) {
+                return;
+            }
             for item in self.impl_or_trait_item(trait_def_id) {
                 // Check whether `trait_def_id` defines a method with suitable name.
                 if !self.has_applicable_self(&item) {
@@ -1003,9 +1040,9 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
         debug!("pick: actual search failed, assemble diagnostics");
 
-        let static_candidates = mem::take(&mut self.static_candidates);
+        let static_candidates = std::mem::take(self.static_candidates.get_mut());
         let private_candidate = self.private_candidate.take();
-        let unsatisfied_predicates = mem::take(&mut self.unsatisfied_predicates);
+        let unsatisfied_predicates = std::mem::take(self.unsatisfied_predicates.get_mut());
 
         // things failed, so lets look at all traits, for diagnostic purposes now:
         self.reset();
@@ -1050,7 +1087,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         }))
     }
 
-    fn pick_core(&mut self) -> Option<PickResult<'tcx>> {
+    fn pick_core(&self) -> Option<PickResult<'tcx>> {
         let pick = self.pick_all_method(Some(&mut vec![]));
 
         // In this case unstable picking is done by `pick_method`.
@@ -1065,11 +1102,10 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     }
 
     fn pick_all_method(
-        &mut self,
+        &self,
         mut unstable_candidates: Option<&mut Vec<(Candidate<'tcx>, Symbol)>>,
     ) -> Option<PickResult<'tcx>> {
-        let steps = self.steps.clone();
-        steps
+        self.steps
             .iter()
             .filter(|step| {
                 debug!("pick_all_method: step={:?}", step);
@@ -1077,7 +1113,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 // a raw pointer
                 !step.self_ty.references_error() && !step.from_unsafe_deref
             })
-            .flat_map(|step| {
+            .find_map(|step| {
                 let InferOk { value: self_ty, obligations: _ } = self
                     .fcx
                     .probe_instantiate_query_response(
@@ -1113,7 +1149,6 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                         })
                     })
             })
-            .next()
     }
 
     /// For each type `T` in the step list, this attempts to find a method where
@@ -1123,7 +1158,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     /// to transparently pass `&mut` pointers, in particular, without consuming
     /// them for their entire lifetime.
     fn pick_by_value_method(
-        &mut self,
+        &self,
         step: &CandidateStep<'tcx>,
         self_ty: Ty<'tcx>,
         unstable_candidates: Option<&mut Vec<(Candidate<'tcx>, Symbol)>>,
@@ -1151,7 +1186,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     }
 
     fn pick_autorefd_method(
-        &mut self,
+        &self,
         step: &CandidateStep<'tcx>,
         self_ty: Ty<'tcx>,
         mutbl: hir::Mutability,
@@ -1177,7 +1212,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     /// special case for this is because going from `*mut T` to `*const T` with autoderefs and
     /// autorefs would require dereferencing the pointer, which is not safe.
     fn pick_const_ptr_method(
-        &mut self,
+        &self,
         step: &CandidateStep<'tcx>,
         self_ty: Ty<'tcx>,
         unstable_candidates: Option<&mut Vec<(Candidate<'tcx>, Symbol)>>,
@@ -1202,7 +1237,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         })
     }
 
-    fn pick_method_with_unstable(&mut self, self_ty: Ty<'tcx>) -> Option<PickResult<'tcx>> {
+    fn pick_method_with_unstable(&self, self_ty: Ty<'tcx>) -> Option<PickResult<'tcx>> {
         debug!("pick_method_with_unstable(self_ty={})", self.ty_to_string(self_ty));
 
         let mut possibly_unsatisfied_predicates = Vec::new();
@@ -1213,7 +1248,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             debug!("searching {} candidates", kind);
             let res = self.consider_candidates(
                 self_ty,
-                candidates.iter(),
+                candidates,
                 &mut possibly_unsatisfied_predicates,
                 Some(&mut vec![]),
             );
@@ -1222,21 +1257,27 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             }
         }
 
-        debug!("searching unstable candidates");
-        let res = self.consider_candidates(
-            self_ty,
-            self.inherent_candidates.iter().chain(&self.extension_candidates),
-            &mut possibly_unsatisfied_predicates,
-            None,
-        );
-        if res.is_none() {
-            self.unsatisfied_predicates.extend(possibly_unsatisfied_predicates);
+        for (kind, candidates) in
+            &[("inherent", &self.inherent_candidates), ("extension", &self.extension_candidates)]
+        {
+            debug!("searching unstable {kind} candidates");
+            let res = self.consider_candidates(
+                self_ty,
+                candidates,
+                &mut possibly_unsatisfied_predicates,
+                None,
+            );
+            if res.is_some() {
+                return res;
+            }
         }
-        res
+
+        self.unsatisfied_predicates.borrow_mut().extend(possibly_unsatisfied_predicates);
+        None
     }
 
     fn pick_method(
-        &mut self,
+        &self,
         self_ty: Ty<'tcx>,
         mut unstable_candidates: Option<&mut Vec<(Candidate<'tcx>, Symbol)>>,
     ) -> Option<PickResult<'tcx>> {
@@ -1254,7 +1295,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
             debug!("searching {} candidates", kind);
             let res = self.consider_candidates(
                 self_ty,
-                candidates.iter(),
+                candidates,
                 &mut possibly_unsatisfied_predicates,
                 unstable_candidates.as_deref_mut(),
             );
@@ -1266,28 +1307,24 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         // `pick_method` may be called twice for the same self_ty if no stable methods
         // match. Only extend once.
         if unstable_candidates.is_some() {
-            self.unsatisfied_predicates.extend(possibly_unsatisfied_predicates);
+            self.unsatisfied_predicates.borrow_mut().extend(possibly_unsatisfied_predicates);
         }
         None
     }
 
-    fn consider_candidates<'b, ProbesIter>(
+    fn consider_candidates(
         &self,
         self_ty: Ty<'tcx>,
-        probes: ProbesIter,
+        candidates: &[Candidate<'tcx>],
         possibly_unsatisfied_predicates: &mut Vec<(
             ty::Predicate<'tcx>,
             Option<ty::Predicate<'tcx>>,
             Option<ObligationCause<'tcx>>,
         )>,
         mut unstable_candidates: Option<&mut Vec<(Candidate<'tcx>, Symbol)>>,
-    ) -> Option<PickResult<'tcx>>
-    where
-        ProbesIter: Iterator<Item = &'b Candidate<'tcx>> + Clone,
-        'tcx: 'b,
-    {
-        let mut applicable_candidates: Vec<_> = probes
-            .clone()
+    ) -> Option<PickResult<'tcx>> {
+        let mut applicable_candidates: Vec<_> = candidates
+            .iter()
             .map(|probe| {
                 (probe, self.consider_probe(self_ty, probe, possibly_unsatisfied_predicates))
             })
@@ -1305,11 +1342,11 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         }
 
         if let Some(uc) = &mut unstable_candidates {
-            applicable_candidates.retain(|&(p, _)| {
+            applicable_candidates.retain(|&(candidate, _)| {
                 if let stability::EvalResult::Deny { feature, .. } =
-                    self.tcx.eval_stability(p.item.def_id, None, self.span, None)
+                    self.tcx.eval_stability(candidate.item.def_id, None, self.span, None)
                 {
-                    uc.push((p.clone(), feature));
+                    uc.push((candidate.clone(), feature));
                     return false;
                 }
                 true
@@ -1317,7 +1354,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         }
 
         if applicable_candidates.len() > 1 {
-            let sources = probes.map(|p| self.candidate_source(p, self_ty)).collect();
+            let sources = candidates.iter().map(|p| self.candidate_source(p, self_ty)).collect();
             return Some(Err(MethodError::Ambiguity(sources)));
         }
 
@@ -1505,7 +1542,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                     let InferOk {
                         value: normalized_xform_ret_ty,
                         obligations: normalization_obligations,
-                    } = self.fcx.at(&cause, self.param_env).normalize(probe.xform_ret_ty);
+                    } = self.fcx.at(&cause, self.param_env).normalize(xform_ret_ty);
                     xform_ret_ty = normalized_xform_ret_ty;
                     debug!("xform_ret_ty after normalization: {:?}", xform_ret_ty);
 
@@ -1519,7 +1556,23 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
                     // Convert the bounds into obligations.
                     let impl_obligations = traits::predicates_for_generics(
-                        move |_, _| cause.clone(),
+                        |_idx, span| {
+                            let misc = traits::ObligationCause::misc(span, self.body_id);
+                            let parent_trait_pred = ty::Binder::dummy(ty::TraitPredicate {
+                                trait_ref: ty::TraitRef::from_method(self.tcx, impl_def_id, substs),
+                                constness: ty::BoundConstness::NotConst,
+                                polarity: ty::ImplPolarity::Positive,
+                            });
+                            misc.derived_cause(parent_trait_pred, |derived| {
+                                traits::ImplDerivedObligation(Box::new(
+                                    traits::ImplDerivedObligationCause {
+                                        derived,
+                                        impl_def_id,
+                                        span,
+                                    },
+                                ))
+                            })
+                        },
                         self.param_env,
                         impl_bounds,
                     );
@@ -1534,11 +1587,29 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                         let o = self.resolve_vars_if_possible(o);
                         if !self.predicate_may_hold(&o) {
                             result = ProbeResult::NoMatch;
-                            possibly_unsatisfied_predicates.push((
-                                o.predicate,
-                                None,
-                                Some(o.cause),
-                            ));
+                            let parent_o = o.clone();
+                            let implied_obligations =
+                                traits::elaborate_obligations(self.tcx, vec![o]);
+                            for o in implied_obligations {
+                                let parent = if o == parent_o {
+                                    None
+                                } else {
+                                    if o.predicate.to_opt_poly_trait_pred().map(|p| p.def_id())
+                                        == self.tcx.lang_items().sized_trait()
+                                    {
+                                        // We don't care to talk about implicit `Sized` bounds.
+                                        continue;
+                                    }
+                                    Some(parent_o.predicate)
+                                };
+                                if !self.predicate_may_hold(&o) {
+                                    possibly_unsatisfied_predicates.push((
+                                        o.predicate,
+                                        parent,
+                                        Some(o.cause),
+                                    ));
+                                }
+                            }
                         }
                     }
                 }
@@ -1562,7 +1633,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                         ty::Binder::dummy(trait_ref).without_const().to_predicate(self.tcx);
                     parent_pred = Some(predicate);
                     let obligation =
-                        traits::Obligation::new(self.tcx, cause, self.param_env, predicate);
+                        traits::Obligation::new(self.tcx, cause.clone(), self.param_env, predicate);
                     if !self.predicate_may_hold(&obligation) {
                         result = ProbeResult::NoMatch;
                         if self.probe(|_| {
@@ -1621,22 +1692,48 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 }
             }
 
-            if let ProbeResult::Match = result {
-                if let (Some(return_ty), Some(xform_ret_ty)) = (self.return_type, xform_ret_ty) {
-                    let xform_ret_ty = self.resolve_vars_if_possible(xform_ret_ty);
-                    debug!(
-                        "comparing return_ty {:?} with xform ret ty {:?}",
-                        return_ty, probe.xform_ret_ty
-                    );
-                    if self
-                        .at(&ObligationCause::dummy(), self.param_env)
-                        .define_opaque_types(false)
-                        .sup(return_ty, xform_ret_ty)
-                        .is_err()
-                    {
-                        return ProbeResult::BadReturnType;
+            if let ProbeResult::Match = result
+                && let Some(return_ty) = self.return_type
+                && let Some(mut xform_ret_ty) = xform_ret_ty
+            {
+                // `xform_ret_ty` has only been normalized for `InherentImplCandidate`.
+                // We don't normalize the other candidates for perf/backwards-compat reasons...
+                // but `self.return_type` is only set on the diagnostic-path, so we
+                // should be okay doing it here.
+                if !matches!(probe.kind, InherentImplCandidate(..)) {
+                    let InferOk {
+                        value: normalized_xform_ret_ty,
+                        obligations: normalization_obligations,
+                    } = self.fcx.at(&cause, self.param_env).normalize(xform_ret_ty);
+                    xform_ret_ty = normalized_xform_ret_ty;
+                    debug!("xform_ret_ty after normalization: {:?}", xform_ret_ty);
+                    // Evaluate those obligations to see if they might possibly hold.
+                    for o in normalization_obligations {
+                        let o = self.resolve_vars_if_possible(o);
+                        if !self.predicate_may_hold(&o) {
+                            result = ProbeResult::NoMatch;
+                            possibly_unsatisfied_predicates.push((
+                                o.predicate,
+                                None,
+                                Some(o.cause),
+                            ));
+                        }
                     }
                 }
+
+                debug!(
+                    "comparing return_ty {:?} with xform ret ty {:?}",
+                    return_ty, xform_ret_ty
+                );
+                if let ProbeResult::Match = result
+                    && self
+                    .at(&ObligationCause::dummy(), self.param_env)
+                    .define_opaque_types(false)
+                    .sup(return_ty, xform_ret_ty)
+                    .is_err()
+                {
+                    result = ProbeResult::BadReturnType;
+                }
             }
 
             result
@@ -1650,7 +1747,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     /// probe. This will result in a pending obligation so when more type-info is available we can
     /// make the final decision.
     ///
-    /// Example (`src/test/ui/method-two-trait-defer-resolution-1.rs`):
+    /// Example (`tests/ui/method-two-trait-defer-resolution-1.rs`):
     ///
     /// ```ignore (illustrative)
     /// trait Foo { ... }
@@ -1701,7 +1798,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 self.mode,
                 self.method_name,
                 self.return_type,
-                self.orig_steps_var_values.clone(),
+                &self.orig_steps_var_values,
                 steps,
                 self.scope_expr_id,
             );
@@ -1763,8 +1860,8 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         // -- but this could be overcome.
     }
 
-    fn record_static_candidate(&mut self, source: CandidateSource) {
-        self.static_candidates.push(source);
+    fn record_static_candidate(&self, source: CandidateSource) {
+        self.static_candidates.borrow_mut().push(source);
     }
 
     #[instrument(level = "debug", skip(self))]
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index db93cfab2..2e1fc4c38 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -2,6 +2,7 @@
 //! found or is otherwise invalid.
 
 use crate::errors;
+use crate::Expectation;
 use crate::FnCtxt;
 use rustc_ast::ast::Mutability;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
@@ -25,7 +26,7 @@ use rustc_middle::infer::unify_key::{ConstVariableOrigin, ConstVariableOriginKin
 use rustc_middle::traits::util::supertraits;
 use rustc_middle::ty::fast_reject::DeepRejectCtxt;
 use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
-use rustc_middle::ty::print::with_crate_prefix;
+use rustc_middle::ty::print::{with_crate_prefix, with_forced_trimmed_paths};
 use rustc_middle::ty::{self, DefIdTree, GenericArgKind, Ty, TyCtxt, TypeVisitable};
 use rustc_middle::ty::{IsSuggestable, ToPolyTraitRef};
 use rustc_span::symbol::{kw, sym, Ident};
@@ -100,982 +101,1099 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.autoderef(span, ty).any(|(ty, _)| matches!(ty.kind(), ty::Slice(..) | ty::Array(..)))
     }
 
+    #[instrument(level = "debug", skip(self))]
     pub fn report_method_error(
         &self,
-        mut span: Span,
+        span: Span,
         rcvr_ty: Ty<'tcx>,
         item_name: Ident,
         source: SelfSource<'tcx>,
         error: MethodError<'tcx>,
         args: Option<(&'tcx hir::Expr<'tcx>, &'tcx [hir::Expr<'tcx>])>,
+        expected: Expectation<'tcx>,
     ) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> {
         // Avoid suggestions when we don't know what's going on.
         if rcvr_ty.references_error() {
             return None;
         }
 
-        let report_candidates = |span: Span,
-                                 err: &mut Diagnostic,
-                                 sources: &mut Vec<CandidateSource>,
-                                 sugg_span: Option<Span>| {
-            sources.sort();
-            sources.dedup();
-            // Dynamic limit to avoid hiding just one candidate, which is silly.
-            let limit = if sources.len() == 5 { 5 } else { 4 };
-
-            for (idx, source) in sources.iter().take(limit).enumerate() {
-                match *source {
-                    CandidateSource::Impl(impl_did) => {
-                        // Provide the best span we can. Use the item, if local to crate, else
-                        // the impl, if local to crate (item may be defaulted), else nothing.
-                        let Some(item) = self.associated_value(impl_did, item_name).or_else(|| {
-                            let impl_trait_ref = self.tcx.impl_trait_ref(impl_did)?;
-                            self.associated_value(impl_trait_ref.def_id, item_name)
-                        }) else {
-                            continue;
-                        };
+        let sugg_span = if let SelfSource::MethodCall(expr) = source {
+            // Given `foo.bar(baz)`, `expr` is `bar`, but we want to point to the whole thing.
+            self.tcx.hir().expect_expr(self.tcx.hir().parent_id(expr.hir_id)).span
+        } else {
+            span
+        };
 
-                        let note_span = if item.def_id.is_local() {
-                            Some(self.tcx.def_span(item.def_id))
-                        } else if impl_did.is_local() {
-                            Some(self.tcx.def_span(impl_did))
-                        } else {
-                            None
-                        };
+        match error {
+            MethodError::NoMatch(mut no_match_data) => {
+                return self.report_no_match_method_error(
+                    span,
+                    rcvr_ty,
+                    item_name,
+                    source,
+                    args,
+                    sugg_span,
+                    &mut no_match_data,
+                    expected,
+                );
+            }
 
-                        let impl_ty = self.tcx.at(span).type_of(impl_did);
+            MethodError::Ambiguity(mut sources) => {
+                let mut err = struct_span_err!(
+                    self.sess(),
+                    item_name.span,
+                    E0034,
+                    "multiple applicable items in scope"
+                );
+                err.span_label(item_name.span, format!("multiple `{}` found", item_name));
 
-                        let insertion = match self.tcx.impl_trait_ref(impl_did) {
-                            None => String::new(),
-                            Some(trait_ref) => format!(
-                                " of the trait `{}`",
-                                self.tcx.def_path_str(trait_ref.def_id)
-                            ),
-                        };
+                self.note_candidates_on_method_error(
+                    rcvr_ty,
+                    item_name,
+                    args,
+                    span,
+                    &mut err,
+                    &mut sources,
+                    Some(sugg_span),
+                );
+                err.emit();
+            }
 
-                        let (note_str, idx) = if sources.len() > 1 {
-                            (
-                                format!(
-                                    "candidate #{} is defined in an impl{} for the type `{}`",
-                                    idx + 1,
-                                    insertion,
-                                    impl_ty,
-                                ),
-                                Some(idx + 1),
-                            )
-                        } else {
-                            (
-                                format!(
-                                    "the candidate is defined in an impl{} for the type `{}`",
-                                    insertion, impl_ty,
-                                ),
-                                None,
-                            )
-                        };
-                        if let Some(note_span) = note_span {
-                            // We have a span pointing to the method. Show note with snippet.
-                            err.span_note(note_span, &note_str);
-                        } else {
-                            err.note(&note_str);
-                        }
-                        if let Some(sugg_span) = sugg_span
-                            && let Some(trait_ref) = self.tcx.impl_trait_ref(impl_did) {
-                            let path = self.tcx.def_path_str(trait_ref.def_id);
-
-                            let ty = match item.kind {
-                                ty::AssocKind::Const | ty::AssocKind::Type => rcvr_ty,
-                                ty::AssocKind::Fn => self
-                                    .tcx
-                                    .fn_sig(item.def_id)
-                                    .inputs()
-                                    .skip_binder()
-                                    .get(0)
-                                    .filter(|ty| ty.is_region_ptr() && !rcvr_ty.is_region_ptr())
-                                    .copied()
-                                    .unwrap_or(rcvr_ty),
-                            };
-                            print_disambiguation_help(
-                                item_name,
-                                args,
-                                err,
-                                path,
-                                ty,
-                                item.kind,
-                                item.def_id,
-                                sugg_span,
-                                idx,
-                                self.tcx.sess.source_map(),
-                                item.fn_has_self_parameter,
-                            );
+            MethodError::PrivateMatch(kind, def_id, out_of_scope_traits) => {
+                let kind = kind.descr(def_id);
+                let mut err = struct_span_err!(
+                    self.tcx.sess,
+                    item_name.span,
+                    E0624,
+                    "{} `{}` is private",
+                    kind,
+                    item_name
+                );
+                err.span_label(item_name.span, &format!("private {}", kind));
+                let sp = self
+                    .tcx
+                    .hir()
+                    .span_if_local(def_id)
+                    .unwrap_or_else(|| self.tcx.def_span(def_id));
+                err.span_label(sp, &format!("private {} defined here", kind));
+                self.suggest_valid_traits(&mut err, out_of_scope_traits);
+                err.emit();
+            }
+
+            MethodError::IllegalSizedBound { candidates, needs_mut, bound_span, self_expr } => {
+                let msg = if needs_mut {
+                    with_forced_trimmed_paths!(format!(
+                        "the `{item_name}` method cannot be invoked on `{rcvr_ty}`"
+                    ))
+                } else {
+                    format!("the `{item_name}` method cannot be invoked on a trait object")
+                };
+                let mut err = self.sess().struct_span_err(span, &msg);
+                if !needs_mut {
+                    err.span_label(bound_span, "this has a `Sized` requirement");
+                }
+                if !candidates.is_empty() {
+                    let help = format!(
+                        "{an}other candidate{s} {were} found in the following trait{s}, perhaps \
+                         add a `use` for {one_of_them}:",
+                        an = if candidates.len() == 1 { "an" } else { "" },
+                        s = pluralize!(candidates.len()),
+                        were = pluralize!("was", candidates.len()),
+                        one_of_them = if candidates.len() == 1 { "it" } else { "one_of_them" },
+                    );
+                    self.suggest_use_candidates(&mut err, help, candidates);
+                }
+                if let ty::Ref(region, t_type, mutability) = rcvr_ty.kind() {
+                    if needs_mut {
+                        let trait_type = self.tcx.mk_ref(
+                            *region,
+                            ty::TypeAndMut { ty: *t_type, mutbl: mutability.invert() },
+                        );
+                        let msg = format!("you need `{}` instead of `{}`", trait_type, rcvr_ty);
+                        let mut kind = &self_expr.kind;
+                        while let hir::ExprKind::AddrOf(_, _, expr)
+                        | hir::ExprKind::Unary(hir::UnOp::Deref, expr) = kind
+                        {
+                            kind = &expr.kind;
                         }
-                    }
-                    CandidateSource::Trait(trait_did) => {
-                        let Some(item) = self.associated_value(trait_did, item_name) else { continue };
-                        let item_span = self.tcx.def_span(item.def_id);
-                        let idx = if sources.len() > 1 {
-                            let msg = &format!(
-                                "candidate #{} is defined in the trait `{}`",
-                                idx + 1,
-                                self.tcx.def_path_str(trait_did)
+                        if let hir::ExprKind::Path(hir::QPath::Resolved(None, path)) = kind
+                            && let hir::def::Res::Local(hir_id) = path.res
+                            && let Some(hir::Node::Pat(b)) = self.tcx.hir().find(hir_id)
+                            && let Some(hir::Node::Param(p)) = self.tcx.hir().find_parent(b.hir_id)
+                            && let Some(node) = self.tcx.hir().find_parent(p.hir_id)
+                            && let Some(decl) = node.fn_decl()
+                            && let Some(ty) = decl.inputs.iter().find(|ty| ty.span == p.ty_span)
+                            && let hir::TyKind::Ref(_, mut_ty) = &ty.kind
+                            && let hir::Mutability::Not = mut_ty.mutbl
+                        {
+                            err.span_suggestion_verbose(
+                                mut_ty.ty.span.shrink_to_lo(),
+                                &msg,
+                                "mut ",
+                                Applicability::MachineApplicable,
                             );
-                            err.span_note(item_span, msg);
-                            Some(idx + 1)
                         } else {
-                            let msg = &format!(
-                                "the candidate is defined in the trait `{}`",
-                                self.tcx.def_path_str(trait_did)
-                            );
-                            err.span_note(item_span, msg);
-                            None
-                        };
-                        if let Some(sugg_span) = sugg_span {
-                            let path = self.tcx.def_path_str(trait_did);
-                            print_disambiguation_help(
-                                item_name,
-                                args,
-                                err,
-                                path,
-                                rcvr_ty,
-                                item.kind,
-                                item.def_id,
-                                sugg_span,
-                                idx,
-                                self.tcx.sess.source_map(),
-                                item.fn_has_self_parameter,
-                            );
+                            err.help(&msg);
                         }
                     }
                 }
+                err.emit();
             }
-            if sources.len() > limit {
-                err.note(&format!("and {} others", sources.len() - limit));
-            }
-        };
 
-        let sugg_span = if let SelfSource::MethodCall(expr) = source {
-            // Given `foo.bar(baz)`, `expr` is `bar`, but we want to point to the whole thing.
-            self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id)).span
+            MethodError::BadReturnType => bug!("no return type expectations but got BadReturnType"),
+        }
+        None
+    }
+
+    pub fn report_no_match_method_error(
+        &self,
+        mut span: Span,
+        rcvr_ty: Ty<'tcx>,
+        item_name: Ident,
+        source: SelfSource<'tcx>,
+        args: Option<(&'tcx hir::Expr<'tcx>, &'tcx [hir::Expr<'tcx>])>,
+        sugg_span: Span,
+        no_match_data: &mut NoMatchData<'tcx>,
+        expected: Expectation<'tcx>,
+    ) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> {
+        let mode = no_match_data.mode;
+        let tcx = self.tcx;
+        let rcvr_ty = self.resolve_vars_if_possible(rcvr_ty);
+        let ty_str = with_forced_trimmed_paths!(self.ty_to_string(rcvr_ty));
+        let is_method = mode == Mode::MethodCall;
+        let unsatisfied_predicates = &no_match_data.unsatisfied_predicates;
+        let lev_candidate = no_match_data.lev_candidate;
+        let item_kind = if is_method {
+            "method"
+        } else if rcvr_ty.is_enum() {
+            "variant or associated item"
         } else {
-            span
+            match (item_name.as_str().chars().next(), rcvr_ty.is_fresh_ty()) {
+                (Some(name), false) if name.is_lowercase() => "function or associated item",
+                (Some(_), false) => "associated item",
+                (Some(_), true) | (None, false) => "variant or associated item",
+                (None, true) => "variant",
+            }
         };
 
-        match error {
-            MethodError::NoMatch(NoMatchData {
-                mut static_candidates,
-                unsatisfied_predicates,
-                out_of_scope_traits,
-                lev_candidate,
-                mode,
-            }) => {
-                let tcx = self.tcx;
-
-                let rcvr_ty = self.resolve_vars_if_possible(rcvr_ty);
-                let ty_str = self.ty_to_string(rcvr_ty);
-                let is_method = mode == Mode::MethodCall;
-                let item_kind = if is_method {
-                    "method"
-                } else if rcvr_ty.is_enum() {
-                    "variant or associated item"
-                } else {
-                    match (item_name.as_str().chars().next(), rcvr_ty.is_fresh_ty()) {
-                        (Some(name), false) if name.is_lowercase() => "function or associated item",
-                        (Some(_), false) => "associated item",
-                        (Some(_), true) | (None, false) => "variant or associated item",
-                        (None, true) => "variant",
+        if self.suggest_wrapping_range_with_parens(tcx, rcvr_ty, source, span, item_name, &ty_str)
+            || self.suggest_constraining_numerical_ty(
+                tcx, rcvr_ty, source, span, item_kind, item_name, &ty_str,
+            )
+        {
+            return None;
+        }
+        span = item_name.span;
+
+        // Don't show generic arguments when the method can't be found in any implementation (#81576).
+        let mut ty_str_reported = ty_str.clone();
+        if let ty::Adt(_, generics) = rcvr_ty.kind() {
+            if generics.len() > 0 {
+                let mut autoderef = self.autoderef(span, rcvr_ty);
+                let candidate_found = autoderef.any(|(ty, _)| {
+                    if let ty::Adt(adt_def, _) = ty.kind() {
+                        self.tcx
+                            .inherent_impls(adt_def.did())
+                            .iter()
+                            .any(|def_id| self.associated_value(*def_id, item_name).is_some())
+                    } else {
+                        false
                     }
-                };
-
-                if self.suggest_wrapping_range_with_parens(
-                    tcx, rcvr_ty, source, span, item_name, &ty_str,
-                ) || self.suggest_constraining_numerical_ty(
-                    tcx, rcvr_ty, source, span, item_kind, item_name, &ty_str,
-                ) {
-                    return None;
-                }
-                span = item_name.span;
-
-                // Don't show generic arguments when the method can't be found in any implementation (#81576).
-                let mut ty_str_reported = ty_str.clone();
-                if let ty::Adt(_, generics) = rcvr_ty.kind() {
-                    if generics.len() > 0 {
-                        let mut autoderef = self.autoderef(span, rcvr_ty);
-                        let candidate_found = autoderef.any(|(ty, _)| {
-                            if let ty::Adt(adt_def, _) = ty.kind() {
-                                self.tcx
-                                    .inherent_impls(adt_def.did())
-                                    .iter()
-                                    .filter_map(|def_id| self.associated_value(*def_id, item_name))
-                                    .count()
-                                    >= 1
-                            } else {
-                                false
-                            }
-                        });
-                        let has_deref = autoderef.step_count() > 0;
-                        if !candidate_found && !has_deref && unsatisfied_predicates.is_empty() {
-                            if let Some((path_string, _)) = ty_str.split_once('<') {
-                                ty_str_reported = path_string.to_string();
-                            }
-                        }
+                });
+                let has_deref = autoderef.step_count() > 0;
+                if !candidate_found && !has_deref && unsatisfied_predicates.is_empty() {
+                    if let Some((path_string, _)) = ty_str.split_once('<') {
+                        ty_str_reported = path_string.to_string();
                     }
                 }
+            }
+        }
 
-                let mut err = struct_span_err!(
-                    tcx.sess,
-                    span,
-                    E0599,
-                    "no {} named `{}` found for {} `{}` in the current scope",
-                    item_kind,
-                    item_name,
-                    rcvr_ty.prefix_string(self.tcx),
-                    ty_str_reported,
-                );
-                if rcvr_ty.references_error() {
-                    err.downgrade_to_delayed_bug();
-                }
+        let mut err = struct_span_err!(
+            tcx.sess,
+            span,
+            E0599,
+            "no {} named `{}` found for {} `{}` in the current scope",
+            item_kind,
+            item_name,
+            rcvr_ty.prefix_string(self.tcx),
+            ty_str_reported,
+        );
+        if rcvr_ty.references_error() {
+            err.downgrade_to_delayed_bug();
+        }
 
-                if let Mode::MethodCall = mode && let SelfSource::MethodCall(cal) = source {
-                    self.suggest_await_before_method(
-                        &mut err, item_name, rcvr_ty, cal, span,
-                    );
-                }
-                if let Some(span) = tcx.resolutions(()).confused_type_with_std_module.get(&span) {
-                    err.span_suggestion(
-                        span.shrink_to_lo(),
-                        "you are looking for the module in `std`, not the primitive type",
-                        "std::",
-                        Applicability::MachineApplicable,
-                    );
-                }
-                if let ty::RawPtr(_) = &rcvr_ty.kind() {
-                    err.note(
-                        "try using `<*const T>::as_ref()` to get a reference to the \
-                         type behind the pointer: https://doc.rust-lang.org/std/\
-                         primitive.pointer.html#method.as_ref",
-                    );
-                    err.note(
-                        "using `<*const T>::as_ref()` on a pointer which is unaligned or points \
-                         to invalid or uninitialized memory is undefined behavior",
-                    );
-                }
+        if let Mode::MethodCall = mode && let SelfSource::MethodCall(cal) = source {
+            self.suggest_await_before_method(
+                &mut err, item_name, rcvr_ty, cal, span, expected.only_has_type(self),
+            );
+        }
+        if let Some(span) =
+            tcx.resolutions(()).confused_type_with_std_module.get(&span.with_parent(None))
+        {
+            err.span_suggestion(
+                span.shrink_to_lo(),
+                "you are looking for the module in `std`, not the primitive type",
+                "std::",
+                Applicability::MachineApplicable,
+            );
+        }
+        if let ty::RawPtr(_) = &rcvr_ty.kind() {
+            err.note(
+                "try using `<*const T>::as_ref()` to get a reference to the \
+                 type behind the pointer: https://doc.rust-lang.org/std/\
+                 primitive.pointer.html#method.as_ref",
+            );
+            err.note(
+                "using `<*const T>::as_ref()` on a pointer which is unaligned or points \
+                 to invalid or uninitialized memory is undefined behavior",
+            );
+        }
 
-                let ty_span = match rcvr_ty.kind() {
-                    ty::Param(param_type) => Some(
-                        param_type.span_from_generics(self.tcx, self.body_id.owner.to_def_id()),
-                    ),
-                    ty::Adt(def, _) if def.did().is_local() => Some(tcx.def_span(def.did())),
-                    _ => None,
-                };
-                if let Some(span) = ty_span {
-                    err.span_label(
-                        span,
-                        format!(
-                            "{item_kind} `{item_name}` not found for this {}",
-                            rcvr_ty.prefix_string(self.tcx)
-                        ),
-                    );
-                }
+        let ty_span = match rcvr_ty.kind() {
+            ty::Param(param_type) => {
+                Some(param_type.span_from_generics(self.tcx, self.body_id.owner.to_def_id()))
+            }
+            ty::Adt(def, _) if def.did().is_local() => Some(tcx.def_span(def.did())),
+            _ => None,
+        };
+        if let Some(span) = ty_span {
+            err.span_label(
+                span,
+                format!(
+                    "{item_kind} `{item_name}` not found for this {}",
+                    rcvr_ty.prefix_string(self.tcx)
+                ),
+            );
+        }
 
-                if let SelfSource::MethodCall(rcvr_expr) = source {
-                    self.suggest_fn_call(&mut err, rcvr_expr, rcvr_ty, |output_ty| {
-                        let call_expr = self
-                            .tcx
-                            .hir()
-                            .expect_expr(self.tcx.hir().get_parent_node(rcvr_expr.hir_id));
-                        let probe = self.lookup_probe(
-                            item_name,
-                            output_ty,
-                            call_expr,
-                            ProbeScope::AllTraits,
-                        );
-                        probe.is_ok()
-                    });
-                }
+        if let SelfSource::MethodCall(rcvr_expr) = source {
+            self.suggest_fn_call(&mut err, rcvr_expr, rcvr_ty, |output_ty| {
+                let call_expr =
+                    self.tcx.hir().expect_expr(self.tcx.hir().parent_id(rcvr_expr.hir_id));
+                let probe = self.lookup_probe_for_diagnostic(
+                    item_name,
+                    output_ty,
+                    call_expr,
+                    ProbeScope::AllTraits,
+                    expected.only_has_type(self),
+                );
+                probe.is_ok()
+            });
+        }
 
-                let mut custom_span_label = false;
+        let mut custom_span_label = false;
 
-                if !static_candidates.is_empty() {
-                    err.note(
-                        "found the following associated functions; to be used as methods, \
-                         functions must have a `self` parameter",
-                    );
-                    err.span_label(span, "this is an associated function, not a method");
-                    custom_span_label = true;
-                }
-                if static_candidates.len() == 1 {
-                    self.suggest_associated_call_syntax(
-                        &mut err,
-                        &static_candidates,
-                        rcvr_ty,
-                        source,
-                        item_name,
-                        args,
-                        sugg_span,
-                    );
+        let static_candidates = &mut no_match_data.static_candidates;
+        if !static_candidates.is_empty() {
+            err.note(
+                "found the following associated functions; to be used as methods, \
+                 functions must have a `self` parameter",
+            );
+            err.span_label(span, "this is an associated function, not a method");
+            custom_span_label = true;
+        }
+        if static_candidates.len() == 1 {
+            self.suggest_associated_call_syntax(
+                &mut err,
+                &static_candidates,
+                rcvr_ty,
+                source,
+                item_name,
+                args,
+                sugg_span,
+            );
 
-                    report_candidates(span, &mut err, &mut static_candidates, None);
-                } else if static_candidates.len() > 1 {
-                    report_candidates(span, &mut err, &mut static_candidates, Some(sugg_span));
-                }
+            self.note_candidates_on_method_error(
+                rcvr_ty,
+                item_name,
+                args,
+                span,
+                &mut err,
+                static_candidates,
+                None,
+            );
+        } else if static_candidates.len() > 1 {
+            self.note_candidates_on_method_error(
+                rcvr_ty,
+                item_name,
+                args,
+                span,
+                &mut err,
+                static_candidates,
+                Some(sugg_span),
+            );
+        }
 
-                let mut bound_spans = vec![];
-                let mut restrict_type_params = false;
-                let mut unsatisfied_bounds = false;
-                if item_name.name == sym::count && self.is_slice_ty(rcvr_ty, span) {
-                    let msg = "consider using `len` instead";
-                    if let SelfSource::MethodCall(_expr) = source {
-                        err.span_suggestion_short(
-                            span,
-                            msg,
-                            "len",
-                            Applicability::MachineApplicable,
-                        );
-                    } else {
-                        err.span_label(span, msg);
-                    }
-                    if let Some(iterator_trait) = self.tcx.get_diagnostic_item(sym::Iterator) {
-                        let iterator_trait = self.tcx.def_path_str(iterator_trait);
-                        err.note(&format!("`count` is defined on `{iterator_trait}`, which `{rcvr_ty}` does not implement"));
-                    }
-                } else if !unsatisfied_predicates.is_empty() {
-                    let mut type_params = FxHashMap::default();
-
-                    // Pick out the list of unimplemented traits on the receiver.
-                    // This is used for custom error messages with the `#[rustc_on_unimplemented]` attribute.
-                    let mut unimplemented_traits = FxHashMap::default();
-                    let mut unimplemented_traits_only = true;
-                    for (predicate, _parent_pred, cause) in &unsatisfied_predicates {
-                        if let (ty::PredicateKind::Clause(ty::Clause::Trait(p)), Some(cause)) =
-                            (predicate.kind().skip_binder(), cause.as_ref())
-                        {
-                            if p.trait_ref.self_ty() != rcvr_ty {
-                                // This is necessary, not just to keep the errors clean, but also
-                                // because our derived obligations can wind up with a trait ref that
-                                // requires a different param_env to be correctly compared.
-                                continue;
-                            }
-                            unimplemented_traits.entry(p.trait_ref.def_id).or_insert((
-                                predicate.kind().rebind(p.trait_ref),
-                                Obligation {
-                                    cause: cause.clone(),
-                                    param_env: self.param_env,
-                                    predicate: *predicate,
-                                    recursion_depth: 0,
-                                },
-                            ));
-                        }
+        let mut bound_spans = vec![];
+        let mut restrict_type_params = false;
+        let mut unsatisfied_bounds = false;
+        if item_name.name == sym::count && self.is_slice_ty(rcvr_ty, span) {
+            let msg = "consider using `len` instead";
+            if let SelfSource::MethodCall(_expr) = source {
+                err.span_suggestion_short(span, msg, "len", Applicability::MachineApplicable);
+            } else {
+                err.span_label(span, msg);
+            }
+            if let Some(iterator_trait) = self.tcx.get_diagnostic_item(sym::Iterator) {
+                let iterator_trait = self.tcx.def_path_str(iterator_trait);
+                err.note(&format!(
+                    "`count` is defined on `{iterator_trait}`, which `{rcvr_ty}` does not implement"
+                ));
+            }
+        } else if !unsatisfied_predicates.is_empty() {
+            let mut type_params = FxHashMap::default();
+
+            // Pick out the list of unimplemented traits on the receiver.
+            // This is used for custom error messages with the `#[rustc_on_unimplemented]` attribute.
+            let mut unimplemented_traits = FxHashMap::default();
+            let mut unimplemented_traits_only = true;
+            for (predicate, _parent_pred, cause) in unsatisfied_predicates {
+                if let (ty::PredicateKind::Clause(ty::Clause::Trait(p)), Some(cause)) =
+                    (predicate.kind().skip_binder(), cause.as_ref())
+                {
+                    if p.trait_ref.self_ty() != rcvr_ty {
+                        // This is necessary, not just to keep the errors clean, but also
+                        // because our derived obligations can wind up with a trait ref that
+                        // requires a different param_env to be correctly compared.
+                        continue;
                     }
+                    unimplemented_traits.entry(p.trait_ref.def_id).or_insert((
+                        predicate.kind().rebind(p.trait_ref),
+                        Obligation {
+                            cause: cause.clone(),
+                            param_env: self.param_env,
+                            predicate: *predicate,
+                            recursion_depth: 0,
+                        },
+                    ));
+                }
+            }
 
-                    // Make sure that, if any traits other than the found ones were involved,
-                    // we don't don't report an unimplemented trait.
-                    // We don't want to say that `iter::Cloned` is not an iterator, just
-                    // because of some non-Clone item being iterated over.
-                    for (predicate, _parent_pred, _cause) in &unsatisfied_predicates {
-                        match predicate.kind().skip_binder() {
-                            ty::PredicateKind::Clause(ty::Clause::Trait(p))
-                                if unimplemented_traits.contains_key(&p.trait_ref.def_id) => {}
-                            _ => {
-                                unimplemented_traits_only = false;
-                                break;
-                            }
-                        }
+            // Make sure that, if any traits other than the found ones were involved,
+            // we don't don't report an unimplemented trait.
+            // We don't want to say that `iter::Cloned` is not an iterator, just
+            // because of some non-Clone item being iterated over.
+            for (predicate, _parent_pred, _cause) in unsatisfied_predicates {
+                match predicate.kind().skip_binder() {
+                    ty::PredicateKind::Clause(ty::Clause::Trait(p))
+                        if unimplemented_traits.contains_key(&p.trait_ref.def_id) => {}
+                    _ => {
+                        unimplemented_traits_only = false;
+                        break;
                     }
+                }
+            }
 
-                    let mut collect_type_param_suggestions =
-                        |self_ty: Ty<'tcx>, parent_pred: ty::Predicate<'tcx>, obligation: &str| {
-                            // We don't care about regions here, so it's fine to skip the binder here.
-                            if let (ty::Param(_), ty::PredicateKind::Clause(ty::Clause::Trait(p))) =
-                                (self_ty.kind(), parent_pred.kind().skip_binder())
-                            {
-                                let hir = self.tcx.hir();
-                                let node = match p.trait_ref.self_ty().kind() {
-                                    ty::Param(_) => {
-                                        // Account for `fn` items like in `issue-35677.rs` to
-                                        // suggest restricting its type params.
-                                        let parent_body =
-                                            hir.body_owner(hir::BodyId { hir_id: self.body_id });
-                                        Some(hir.get(parent_body))
-                                    }
-                                    ty::Adt(def, _) => {
-                                        def.did().as_local().map(|def_id| hir.get_by_def_id(def_id))
-                                    }
-                                    _ => None,
-                                };
-                                if let Some(hir::Node::Item(hir::Item { kind, .. })) = node {
-                                    if let Some(g) = kind.generics() {
-                                        let key = (
-                                            g.tail_span_for_predicate_suggestion(),
-                                            g.add_where_or_trailing_comma(),
-                                        );
-                                        type_params
-                                            .entry(key)
-                                            .or_insert_with(FxHashSet::default)
-                                            .insert(obligation.to_owned());
-                                    }
-                                }
+            let mut collect_type_param_suggestions =
+                |self_ty: Ty<'tcx>, parent_pred: ty::Predicate<'tcx>, obligation: &str| {
+                    // We don't care about regions here, so it's fine to skip the binder here.
+                    if let (ty::Param(_), ty::PredicateKind::Clause(ty::Clause::Trait(p))) =
+                        (self_ty.kind(), parent_pred.kind().skip_binder())
+                    {
+                        let hir = self.tcx.hir();
+                        let node = match p.trait_ref.self_ty().kind() {
+                            ty::Param(_) => {
+                                // Account for `fn` items like in `issue-35677.rs` to
+                                // suggest restricting its type params.
+                                let parent_body =
+                                    hir.body_owner(hir::BodyId { hir_id: self.body_id });
+                                Some(hir.get(parent_body))
                             }
-                        };
-                    let mut bound_span_label = |self_ty: Ty<'_>, obligation: &str, quiet: &str| {
-                        let msg = format!(
-                            "doesn't satisfy `{}`",
-                            if obligation.len() > 50 { quiet } else { obligation }
-                        );
-                        match &self_ty.kind() {
-                            // Point at the type that couldn't satisfy the bound.
                             ty::Adt(def, _) => {
-                                bound_spans.push((self.tcx.def_span(def.did()), msg))
+                                def.did().as_local().map(|def_id| hir.get_by_def_id(def_id))
                             }
-                            // Point at the trait object that couldn't satisfy the bound.
-                            ty::Dynamic(preds, _, _) => {
-                                for pred in preds.iter() {
-                                    match pred.skip_binder() {
-                                        ty::ExistentialPredicate::Trait(tr) => bound_spans
-                                            .push((self.tcx.def_span(tr.def_id), msg.clone())),
-                                        ty::ExistentialPredicate::Projection(_)
-                                        | ty::ExistentialPredicate::AutoTrait(_) => {}
-                                    }
+                            _ => None,
+                        };
+                        if let Some(hir::Node::Item(hir::Item { kind, .. })) = node
+                            && let Some(g) = kind.generics()
+                        {
+                            let key = (
+                                g.tail_span_for_predicate_suggestion(),
+                                g.add_where_or_trailing_comma(),
+                            );
+                            type_params
+                                .entry(key)
+                                .or_insert_with(FxHashSet::default)
+                                .insert(obligation.to_owned());
+                            return true;
+                        }
+                    }
+                    false
+                };
+            let mut bound_span_label = |self_ty: Ty<'_>, obligation: &str, quiet: &str| {
+                let msg = format!(
+                    "doesn't satisfy `{}`",
+                    if obligation.len() > 50 { quiet } else { obligation }
+                );
+                match &self_ty.kind() {
+                    // Point at the type that couldn't satisfy the bound.
+                    ty::Adt(def, _) => bound_spans.push((self.tcx.def_span(def.did()), msg)),
+                    // Point at the trait object that couldn't satisfy the bound.
+                    ty::Dynamic(preds, _, _) => {
+                        for pred in preds.iter() {
+                            match pred.skip_binder() {
+                                ty::ExistentialPredicate::Trait(tr) => {
+                                    bound_spans.push((self.tcx.def_span(tr.def_id), msg.clone()))
                                 }
+                                ty::ExistentialPredicate::Projection(_)
+                                | ty::ExistentialPredicate::AutoTrait(_) => {}
                             }
-                            // Point at the closure that couldn't satisfy the bound.
-                            ty::Closure(def_id, _) => bound_spans.push((
-                                tcx.def_span(*def_id),
-                                format!("doesn't satisfy `{}`", quiet),
-                            )),
-                            _ => {}
                         }
-                    };
-                    let mut format_pred = |pred: ty::Predicate<'tcx>| {
-                        let bound_predicate = pred.kind();
-                        match bound_predicate.skip_binder() {
-                            ty::PredicateKind::Clause(ty::Clause::Projection(pred)) => {
-                                let pred = bound_predicate.rebind(pred);
-                                // `<Foo as Iterator>::Item = String`.
-                                let projection_ty = pred.skip_binder().projection_ty;
-
-                                let substs_with_infer_self = tcx.mk_substs(
-                                    iter::once(tcx.mk_ty_var(ty::TyVid::from_u32(0)).into())
-                                        .chain(projection_ty.substs.iter().skip(1)),
-                                );
+                    }
+                    // Point at the closure that couldn't satisfy the bound.
+                    ty::Closure(def_id, _) => bound_spans
+                        .push((tcx.def_span(*def_id), format!("doesn't satisfy `{}`", quiet))),
+                    _ => {}
+                }
+            };
+            let mut format_pred = |pred: ty::Predicate<'tcx>| {
+                let bound_predicate = pred.kind();
+                match bound_predicate.skip_binder() {
+                    ty::PredicateKind::Clause(ty::Clause::Projection(pred)) => {
+                        let pred = bound_predicate.rebind(pred);
+                        // `<Foo as Iterator>::Item = String`.
+                        let projection_ty = pred.skip_binder().projection_ty;
+
+                        let substs_with_infer_self = tcx.mk_substs(
+                            iter::once(tcx.mk_ty_var(ty::TyVid::from_u32(0)).into())
+                                .chain(projection_ty.substs.iter().skip(1)),
+                        );
 
-                                let quiet_projection_ty = ty::ProjectionTy {
-                                    substs: substs_with_infer_self,
-                                    item_def_id: projection_ty.item_def_id,
-                                };
+                        let quiet_projection_ty =
+                            tcx.mk_alias_ty(projection_ty.def_id, substs_with_infer_self);
 
-                                let term = pred.skip_binder().term;
+                        let term = pred.skip_binder().term;
 
-                                let obligation = format!("{} = {}", projection_ty, term);
-                                let quiet = format!("{} = {}", quiet_projection_ty, term);
+                        let obligation = format!("{} = {}", projection_ty, term);
+                        let quiet = with_forced_trimmed_paths!(format!(
+                            "{} = {}",
+                            quiet_projection_ty, term
+                        ));
 
-                                bound_span_label(projection_ty.self_ty(), &obligation, &quiet);
-                                Some((obligation, projection_ty.self_ty()))
-                            }
-                            ty::PredicateKind::Clause(ty::Clause::Trait(poly_trait_ref)) => {
-                                let p = poly_trait_ref.trait_ref;
-                                let self_ty = p.self_ty();
-                                let path = p.print_only_trait_path();
-                                let obligation = format!("{}: {}", self_ty, path);
-                                let quiet = format!("_: {}", path);
-                                bound_span_label(self_ty, &obligation, &quiet);
-                                Some((obligation, self_ty))
-                            }
-                            _ => None,
-                        }
-                    };
+                        bound_span_label(projection_ty.self_ty(), &obligation, &quiet);
+                        Some((obligation, projection_ty.self_ty()))
+                    }
+                    ty::PredicateKind::Clause(ty::Clause::Trait(poly_trait_ref)) => {
+                        let p = poly_trait_ref.trait_ref;
+                        let self_ty = p.self_ty();
+                        let path = p.print_only_trait_path();
+                        let obligation = format!("{}: {}", self_ty, path);
+                        let quiet = with_forced_trimmed_paths!(format!("_: {}", path));
+                        bound_span_label(self_ty, &obligation, &quiet);
+                        Some((obligation, self_ty))
+                    }
+                    _ => None,
+                }
+            };
 
-                    // Find all the requirements that come from a local `impl` block.
-                    let mut skip_list: FxHashSet<_> = Default::default();
-                    let mut spanned_predicates: FxHashMap<MultiSpan, _> = Default::default();
-                    for (data, p, parent_p, impl_def_id, cause) in unsatisfied_predicates
-                        .iter()
-                        .filter_map(|(p, parent, c)| c.as_ref().map(|c| (p, parent, c)))
-                        .filter_map(|(p, parent, c)| match c.code() {
-                            ObligationCauseCode::ImplDerivedObligation(data) => {
-                                Some((&data.derived, p, parent, data.impl_def_id, data))
-                            }
-                            _ => None,
-                        })
+            // Find all the requirements that come from a local `impl` block.
+            let mut skip_list: FxHashSet<_> = Default::default();
+            let mut spanned_predicates = FxHashMap::default();
+            for (p, parent_p, impl_def_id, cause) in unsatisfied_predicates
+                .iter()
+                .filter_map(|(p, parent, c)| c.as_ref().map(|c| (p, parent, c)))
+                .filter_map(|(p, parent, c)| match c.code() {
+                    ObligationCauseCode::ImplDerivedObligation(data)
+                        if matches!(p.kind().skip_binder(), ty::PredicateKind::Clause(_)) =>
                     {
-                        let parent_trait_ref = data.parent_trait_pred;
-                        let path = parent_trait_ref.print_modifiers_and_trait_path();
-                        let tr_self_ty = parent_trait_ref.skip_binder().self_ty();
-                        let unsatisfied_msg = "unsatisfied trait bound introduced here";
-                        let derive_msg =
-                            "unsatisfied trait bound introduced in this `derive` macro";
-                        match self.tcx.hir().get_if_local(impl_def_id) {
-                            // Unmet obligation comes from a `derive` macro, point at it once to
-                            // avoid multiple span labels pointing at the same place.
-                            Some(Node::Item(hir::Item {
-                                kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }),
-                                ..
-                            })) if matches!(
-                                self_ty.span.ctxt().outer_expn_data().kind,
-                                ExpnKind::Macro(MacroKind::Derive, _)
-                            ) || matches!(
-                                of_trait.as_ref().map(|t| t
-                                    .path
-                                    .span
-                                    .ctxt()
-                                    .outer_expn_data()
-                                    .kind),
-                                Some(ExpnKind::Macro(MacroKind::Derive, _))
-                            ) =>
-                            {
-                                let span = self_ty.span.ctxt().outer_expn_data().call_site;
-                                let mut spans: MultiSpan = span.into();
-                                spans.push_span_label(span, derive_msg);
-                                let entry = spanned_predicates.entry(spans);
-                                entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p);
-                            }
+                        Some((p, parent, data.impl_def_id, data))
+                    }
+                    _ => None,
+                })
+            {
+                match self.tcx.hir().get_if_local(impl_def_id) {
+                    // Unmet obligation comes from a `derive` macro, point at it once to
+                    // avoid multiple span labels pointing at the same place.
+                    Some(Node::Item(hir::Item {
+                        kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }),
+                        ..
+                    })) if matches!(
+                        self_ty.span.ctxt().outer_expn_data().kind,
+                        ExpnKind::Macro(MacroKind::Derive, _)
+                    ) || matches!(
+                        of_trait.as_ref().map(|t| t.path.span.ctxt().outer_expn_data().kind),
+                        Some(ExpnKind::Macro(MacroKind::Derive, _))
+                    ) =>
+                    {
+                        let span = self_ty.span.ctxt().outer_expn_data().call_site;
+                        let entry = spanned_predicates.entry(span);
+                        let entry = entry.or_insert_with(|| {
+                            (FxHashSet::default(), FxHashSet::default(), Vec::new())
+                        });
+                        entry.0.insert(span);
+                        entry.1.insert((
+                            span,
+                            "unsatisfied trait bound introduced in this `derive` macro",
+                        ));
+                        entry.2.push(p);
+                        skip_list.insert(p);
+                    }
 
-                            // Unmet obligation coming from an `impl`.
-                            Some(Node::Item(hir::Item {
-                                kind:
-                                    hir::ItemKind::Impl(hir::Impl {
-                                        of_trait, self_ty, generics, ..
-                                    }),
-                                span: item_span,
-                                ..
-                            })) => {
-                                let sized_pred =
-                                    unsatisfied_predicates.iter().any(|(pred, _, _)| {
-                                        match pred.kind().skip_binder() {
-                                            ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
-                                                Some(pred.def_id())
-                                                    == self.tcx.lang_items().sized_trait()
-                                                    && pred.polarity == ty::ImplPolarity::Positive
-                                            }
-                                            _ => false,
-                                        }
-                                    });
-                                for param in generics.params {
-                                    if param.span == cause.span && sized_pred {
-                                        let (sp, sugg) = match param.colon_span {
-                                            Some(sp) => (sp.shrink_to_hi(), " ?Sized +"),
-                                            None => (param.span.shrink_to_hi(), ": ?Sized"),
-                                        };
-                                        err.span_suggestion_verbose(
-                                            sp,
-                                            "consider relaxing the type parameter's implicit \
-                                             `Sized` bound",
-                                            sugg,
-                                            Applicability::MachineApplicable,
-                                        );
+                    // Unmet obligation coming from an `impl`.
+                    Some(Node::Item(hir::Item {
+                        kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, generics, .. }),
+                        span: item_span,
+                        ..
+                    })) => {
+                        let sized_pred =
+                            unsatisfied_predicates.iter().any(|(pred, _, _)| {
+                                match pred.kind().skip_binder() {
+                                    ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
+                                        Some(pred.def_id()) == self.tcx.lang_items().sized_trait()
+                                            && pred.polarity == ty::ImplPolarity::Positive
                                     }
+                                    _ => false,
                                 }
-                                if let Some(pred) = parent_p {
-                                    // Done to add the "doesn't satisfy" `span_label`.
-                                    let _ = format_pred(*pred);
-                                }
-                                skip_list.insert(p);
-                                let mut spans = if cause.span != *item_span {
-                                    let mut spans: MultiSpan = cause.span.into();
-                                    spans.push_span_label(cause.span, unsatisfied_msg);
-                                    spans
-                                } else {
-                                    let mut spans = Vec::with_capacity(2);
-                                    if let Some(trait_ref) = of_trait {
-                                        spans.push(trait_ref.path.span);
-                                    }
-                                    spans.push(self_ty.span);
-                                    spans.into()
+                            });
+                        for param in generics.params {
+                            if param.span == cause.span && sized_pred {
+                                let (sp, sugg) = match param.colon_span {
+                                    Some(sp) => (sp.shrink_to_hi(), " ?Sized +"),
+                                    None => (param.span.shrink_to_hi(), ": ?Sized"),
                                 };
-                                if let Some(trait_ref) = of_trait {
-                                    spans.push_span_label(trait_ref.path.span, "");
-                                }
-                                spans.push_span_label(self_ty.span, "");
-
-                                let entry = spanned_predicates.entry(spans);
-                                entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p);
+                                err.span_suggestion_verbose(
+                                    sp,
+                                    "consider relaxing the type parameter's implicit `Sized` bound",
+                                    sugg,
+                                    Applicability::MachineApplicable,
+                                );
                             }
-                            Some(_) => unreachable!(),
-                            None => (),
                         }
-                    }
-                    let mut spanned_predicates: Vec<_> = spanned_predicates.into_iter().collect();
-                    spanned_predicates.sort_by_key(|(span, (_, _, _))| span.primary_span());
-                    for (span, (_path, _self_ty, preds)) in spanned_predicates {
-                        let mut preds: Vec<_> = preds
-                            .into_iter()
-                            .filter_map(|pred| format_pred(*pred))
-                            .map(|(p, _)| format!("`{}`", p))
-                            .collect();
-                        preds.sort();
-                        preds.dedup();
-                        let msg = if let [pred] = &preds[..] {
-                            format!("trait bound {} was not satisfied", pred)
+                        if let Some(pred) = parent_p {
+                            // Done to add the "doesn't satisfy" `span_label`.
+                            let _ = format_pred(*pred);
+                        }
+                        skip_list.insert(p);
+                        let entry = spanned_predicates.entry(self_ty.span);
+                        let entry = entry.or_insert_with(|| {
+                            (FxHashSet::default(), FxHashSet::default(), Vec::new())
+                        });
+                        entry.2.push(p);
+                        if cause.span != *item_span {
+                            entry.0.insert(cause.span);
+                            entry.1.insert((cause.span, "unsatisfied trait bound introduced here"));
                         } else {
-                            format!(
-                                "the following trait bounds were not satisfied:\n{}",
-                                preds.join("\n"),
-                            )
+                            if let Some(trait_ref) = of_trait {
+                                entry.0.insert(trait_ref.path.span);
+                            }
+                            entry.0.insert(self_ty.span);
                         };
-                        err.span_note(span, &msg);
-                        unsatisfied_bounds = true;
+                        if let Some(trait_ref) = of_trait {
+                            entry.1.insert((trait_ref.path.span, ""));
+                        }
+                        entry.1.insert((self_ty.span, ""));
                     }
-
-                    // The requirements that didn't have an `impl` span to show.
-                    let mut bound_list = unsatisfied_predicates
-                        .iter()
-                        .filter_map(|(pred, parent_pred, _cause)| {
-                            format_pred(*pred).map(|(p, self_ty)| {
-                                collect_type_param_suggestions(self_ty, *pred, &p);
-                                (
-                                    match parent_pred {
-                                        None => format!("`{}`", &p),
-                                        Some(parent_pred) => match format_pred(*parent_pred) {
-                                            None => format!("`{}`", &p),
-                                            Some((parent_p, _)) => {
-                                                collect_type_param_suggestions(
-                                                    self_ty,
-                                                    *parent_pred,
-                                                    &p,
-                                                );
-                                                format!(
-                                                    "`{}`\nwhich is required by `{}`",
-                                                    p, parent_p
-                                                )
-                                            }
-                                        },
-                                    },
-                                    *pred,
-                                )
-                            })
-                        })
-                        .filter(|(_, pred)| !skip_list.contains(&pred))
-                        .map(|(t, _)| t)
-                        .enumerate()
-                        .collect::<Vec<(usize, String)>>();
-
-                    for ((span, add_where_or_comma), obligations) in type_params.into_iter() {
-                        restrict_type_params = true;
-                        // #74886: Sort here so that the output is always the same.
-                        let mut obligations = obligations.into_iter().collect::<Vec<_>>();
-                        obligations.sort();
-                        err.span_suggestion_verbose(
-                            span,
-                            &format!(
-                                "consider restricting the type parameter{s} to satisfy the \
-                                 trait bound{s}",
-                                s = pluralize!(obligations.len())
-                            ),
-                            format!("{} {}", add_where_or_comma, obligations.join(", ")),
-                            Applicability::MaybeIncorrect,
+                    Some(Node::Item(hir::Item {
+                        kind: hir::ItemKind::Trait(rustc_ast::ast::IsAuto::Yes, ..),
+                        span: item_span,
+                        ..
+                    })) => {
+                        tcx.sess.delay_span_bug(
+                            *item_span,
+                            "auto trait is invoked with no method error, but no error reported?",
                         );
                     }
-
-                    bound_list.sort_by(|(_, a), (_, b)| a.cmp(b)); // Sort alphabetically.
-                    bound_list.dedup_by(|(_, a), (_, b)| a == b); // #35677
-                    bound_list.sort_by_key(|(pos, _)| *pos); // Keep the original predicate order.
-
-                    if !bound_list.is_empty() || !skip_list.is_empty() {
-                        let bound_list = bound_list
-                            .into_iter()
-                            .map(|(_, path)| path)
-                            .collect::<Vec<_>>()
-                            .join("\n");
-                        let actual_prefix = rcvr_ty.prefix_string(self.tcx);
-                        info!("unimplemented_traits.len() == {}", unimplemented_traits.len());
-                        let (primary_message, label) =
-                            if unimplemented_traits.len() == 1 && unimplemented_traits_only {
-                                unimplemented_traits
-                                    .into_iter()
-                                    .next()
-                                    .map(|(_, (trait_ref, obligation))| {
-                                        if trait_ref.self_ty().references_error()
-                                            || rcvr_ty.references_error()
-                                        {
-                                            // Avoid crashing.
-                                            return (None, None);
-                                        }
-                                        let OnUnimplementedNote { message, label, .. } = self
-                                            .err_ctxt()
-                                            .on_unimplemented_note(trait_ref, &obligation);
-                                        (message, label)
-                                    })
-                                    .unwrap()
-                            } else {
-                                (None, None)
-                            };
-                        let primary_message = primary_message.unwrap_or_else(|| format!(
-                            "the {item_kind} `{item_name}` exists for {actual_prefix} `{ty_str}`, but its trait bounds were not satisfied"
-                        ));
-                        err.set_primary_message(&primary_message);
-                        if let Some(label) = label {
-                            custom_span_label = true;
-                            err.span_label(span, label);
-                        }
-                        if !bound_list.is_empty() {
-                            err.note(&format!(
-                                "the following trait bounds were not satisfied:\n{bound_list}"
-                            ));
-                        }
-                        self.suggest_derive(&mut err, &unsatisfied_predicates);
-
-                        unsatisfied_bounds = true;
+                    Some(Node::Item(hir::Item {
+                        ident, kind: hir::ItemKind::Trait(..), ..
+                    })) => {
+                        skip_list.insert(p);
+                        let entry = spanned_predicates.entry(ident.span);
+                        let entry = entry.or_insert_with(|| {
+                            (FxHashSet::default(), FxHashSet::default(), Vec::new())
+                        });
+                        entry.0.insert(cause.span);
+                        entry.1.insert((ident.span, ""));
+                        entry.1.insert((cause.span, "unsatisfied trait bound introduced here"));
+                        entry.2.push(p);
                     }
+                    Some(node) => unreachable!("encountered `{node:?}`"),
+                    None => (),
+                }
+            }
+            let mut spanned_predicates: Vec<_> = spanned_predicates.into_iter().collect();
+            spanned_predicates.sort_by_key(|(span, _)| *span);
+            for (_, (primary_spans, span_labels, predicates)) in spanned_predicates {
+                let mut preds: Vec<_> = predicates
+                    .iter()
+                    .filter_map(|pred| format_pred(**pred))
+                    .map(|(p, _)| format!("`{}`", p))
+                    .collect();
+                preds.sort();
+                preds.dedup();
+                let msg = if let [pred] = &preds[..] {
+                    format!("trait bound {} was not satisfied", pred)
+                } else {
+                    format!("the following trait bounds were not satisfied:\n{}", preds.join("\n"),)
+                };
+                let mut span: MultiSpan = primary_spans.into_iter().collect::<Vec<_>>().into();
+                for (sp, label) in span_labels {
+                    span.push_span_label(sp, label);
                 }
+                err.span_note(span, &msg);
+                unsatisfied_bounds = true;
+            }
 
-                let label_span_not_found = |err: &mut Diagnostic| {
-                    if unsatisfied_predicates.is_empty() {
-                        err.span_label(span, format!("{item_kind} not found in `{ty_str}`"));
-                        let is_string_or_ref_str = match rcvr_ty.kind() {
-                            ty::Ref(_, ty, _) => {
-                                ty.is_str()
-                                    || matches!(
-                                        ty.kind(),
-                                        ty::Adt(adt, _) if Some(adt.did()) == self.tcx.lang_items().string()
-                                    )
+            let mut suggested_bounds = FxHashSet::default();
+            // The requirements that didn't have an `impl` span to show.
+            let mut bound_list = unsatisfied_predicates
+                .iter()
+                .filter_map(|(pred, parent_pred, _cause)| {
+                    let mut suggested = false;
+                    format_pred(*pred).map(|(p, self_ty)| {
+                        if let Some(parent) = parent_pred && suggested_bounds.contains(parent) {
+                            // We don't suggest `PartialEq` when we already suggest `Eq`.
+                        } else if !suggested_bounds.contains(pred) {
+                            if collect_type_param_suggestions(self_ty, *pred, &p) {
+                                suggested = true;
+                                suggested_bounds.insert(pred);
                             }
-                            ty::Adt(adt, _) => Some(adt.did()) == self.tcx.lang_items().string(),
-                            _ => false,
-                        };
-                        if is_string_or_ref_str && item_name.name == sym::iter {
-                            err.span_suggestion_verbose(
-                                item_name.span,
-                                "because of the in-memory representation of `&str`, to obtain \
-                                 an `Iterator` over each of its codepoint use method `chars`",
-                                "chars",
-                                Applicability::MachineApplicable,
-                            );
                         }
-                        if let ty::Adt(adt, _) = rcvr_ty.kind() {
-                            let mut inherent_impls_candidate = self
-                                .tcx
-                                .inherent_impls(adt.did())
-                                .iter()
-                                .copied()
-                                .filter(|def_id| {
-                                    if let Some(assoc) = self.associated_value(*def_id, item_name) {
-                                        // Check for both mode is the same so we avoid suggesting
-                                        // incorrect associated item.
-                                        match (mode, assoc.fn_has_self_parameter, source) {
-                                            (Mode::MethodCall, true, SelfSource::MethodCall(_)) => {
-                                                // We check that the suggest type is actually
-                                                // different from the received one
-                                                // So we avoid suggestion method with Box<Self>
-                                                // for instance
-                                                self.tcx.at(span).type_of(*def_id) != rcvr_ty
-                                                    && self.tcx.at(span).type_of(*def_id) != rcvr_ty
+                        (
+                            match parent_pred {
+                                None => format!("`{}`", &p),
+                                Some(parent_pred) => match format_pred(*parent_pred) {
+                                    None => format!("`{}`", &p),
+                                    Some((parent_p, _)) => {
+                                        if !suggested
+                                            && !suggested_bounds.contains(pred)
+                                            && !suggested_bounds.contains(parent_pred)
+                                        {
+                                            if collect_type_param_suggestions(
+                                                self_ty,
+                                                *parent_pred,
+                                                &p,
+                                            ) {
+                                                suggested_bounds.insert(pred);
                                             }
-                                            (Mode::Path, false, _) => true,
-                                            _ => false,
                                         }
-                                    } else {
-                                        false
+                                        format!("`{}`\nwhich is required by `{}`", p, parent_p)
                                     }
-                                })
-                                .collect::<Vec<_>>();
-                            if !inherent_impls_candidate.is_empty() {
-                                inherent_impls_candidate.sort();
-                                inherent_impls_candidate.dedup();
-
-                                // number of type to shows at most.
-                                let limit = if inherent_impls_candidate.len() == 5 { 5 } else { 4 };
-                                let type_candidates = inherent_impls_candidate
-                                    .iter()
-                                    .take(limit)
-                                    .map(|impl_item| {
-                                        format!("- `{}`", self.tcx.at(span).type_of(*impl_item))
-                                    })
-                                    .collect::<Vec<_>>()
-                                    .join("\n");
-                                let additional_types = if inherent_impls_candidate.len() > limit {
-                                    format!(
-                                        "\nand {} more types",
-                                        inherent_impls_candidate.len() - limit
-                                    )
-                                } else {
-                                    "".to_string()
-                                };
-                                err.note(&format!(
-                                    "the {item_kind} was found for\n{}{}",
-                                    type_candidates, additional_types
-                                ));
+                                },
+                            },
+                            *pred,
+                        )
+                    })
+                })
+                .filter(|(_, pred)| !skip_list.contains(&pred))
+                .map(|(t, _)| t)
+                .enumerate()
+                .collect::<Vec<(usize, String)>>();
+
+            for ((span, add_where_or_comma), obligations) in type_params.into_iter() {
+                restrict_type_params = true;
+                // #74886: Sort here so that the output is always the same.
+                let mut obligations = obligations.into_iter().collect::<Vec<_>>();
+                obligations.sort();
+                err.span_suggestion_verbose(
+                    span,
+                    &format!(
+                        "consider restricting the type parameter{s} to satisfy the \
+                         trait bound{s}",
+                        s = pluralize!(obligations.len())
+                    ),
+                    format!("{} {}", add_where_or_comma, obligations.join(", ")),
+                    Applicability::MaybeIncorrect,
+                );
+            }
+
+            bound_list.sort_by(|(_, a), (_, b)| a.cmp(b)); // Sort alphabetically.
+            bound_list.dedup_by(|(_, a), (_, b)| a == b); // #35677
+            bound_list.sort_by_key(|(pos, _)| *pos); // Keep the original predicate order.
+
+            if !bound_list.is_empty() || !skip_list.is_empty() {
+                let bound_list =
+                    bound_list.into_iter().map(|(_, path)| path).collect::<Vec<_>>().join("\n");
+                let actual_prefix = rcvr_ty.prefix_string(self.tcx);
+                info!("unimplemented_traits.len() == {}", unimplemented_traits.len());
+                let (primary_message, label) = if unimplemented_traits.len() == 1
+                    && unimplemented_traits_only
+                {
+                    unimplemented_traits
+                        .into_iter()
+                        .next()
+                        .map(|(_, (trait_ref, obligation))| {
+                            if trait_ref.self_ty().references_error() || rcvr_ty.references_error()
+                            {
+                                // Avoid crashing.
+                                return (None, None);
                             }
-                        }
-                    } else {
-                        err.span_label(span, format!("{item_kind} cannot be called on `{ty_str}` due to unsatisfied trait bounds"));
-                    }
+                            let OnUnimplementedNote { message, label, .. } =
+                                self.err_ctxt().on_unimplemented_note(trait_ref, &obligation);
+                            (message, label)
+                        })
+                        .unwrap()
+                } else {
+                    (None, None)
                 };
-
-                // If the method name is the name of a field with a function or closure type,
-                // give a helping note that it has to be called as `(x.f)(...)`.
-                if let SelfSource::MethodCall(expr) = source {
-                    if !self.suggest_calling_field_as_fn(span, rcvr_ty, expr, item_name, &mut err)
-                        && lev_candidate.is_none()
-                        && !custom_span_label
-                    {
-                        label_span_not_found(&mut err);
-                    }
-                } else if !custom_span_label {
-                    label_span_not_found(&mut err);
-                }
-
-                // Don't suggest (for example) `expr.field.clone()` if `expr.clone()`
-                // can't be called due to `typeof(expr): Clone` not holding.
-                if unsatisfied_predicates.is_empty() {
-                    self.suggest_calling_method_on_field(
-                        &mut err, source, span, rcvr_ty, item_name,
-                    );
+                let primary_message = primary_message.unwrap_or_else(|| {
+                    format!(
+                        "the {item_kind} `{item_name}` exists for {actual_prefix} `{ty_str}`, \
+                    but its trait bounds were not satisfied"
+                    )
+                });
+                err.set_primary_message(&primary_message);
+                if let Some(label) = label {
+                    custom_span_label = true;
+                    err.span_label(span, label);
                 }
-
-                self.check_for_inner_self(&mut err, source, rcvr_ty, item_name);
-
-                bound_spans.sort();
-                bound_spans.dedup();
-                for (span, msg) in bound_spans.into_iter() {
-                    err.span_label(span, &msg);
+                if !bound_list.is_empty() {
+                    err.note(&format!(
+                        "the following trait bounds were not satisfied:\n{bound_list}"
+                    ));
                 }
+                self.suggest_derive(&mut err, &unsatisfied_predicates);
 
-                if rcvr_ty.is_numeric() && rcvr_ty.is_fresh() || restrict_type_params {
-                } else {
-                    self.suggest_traits_to_import(
-                        &mut err,
-                        span,
-                        rcvr_ty,
-                        item_name,
-                        args.map(|(_, args)| args.len() + 1),
-                        source,
-                        out_of_scope_traits,
-                        &unsatisfied_predicates,
-                        &static_candidates,
-                        unsatisfied_bounds,
-                    );
-                }
+                unsatisfied_bounds = true;
+            }
+        }
 
-                // Don't emit a suggestion if we found an actual method
-                // that had unsatisfied trait bounds
-                if unsatisfied_predicates.is_empty() && rcvr_ty.is_enum() {
-                    let adt_def = rcvr_ty.ty_adt_def().expect("enum is not an ADT");
-                    if let Some(suggestion) = lev_distance::find_best_match_for_name(
-                        &adt_def.variants().iter().map(|s| s.name).collect::<Vec<_>>(),
-                        item_name.name,
-                        None,
-                    ) {
-                        err.span_suggestion(
-                            span,
-                            "there is a variant with a similar name",
-                            suggestion,
-                            Applicability::MaybeIncorrect,
-                        );
+        let label_span_not_found = |err: &mut Diagnostic| {
+            if unsatisfied_predicates.is_empty() {
+                err.span_label(span, format!("{item_kind} not found in `{ty_str}`"));
+                let is_string_or_ref_str = match rcvr_ty.kind() {
+                    ty::Ref(_, ty, _) => {
+                        ty.is_str()
+                            || matches!(
+                                ty.kind(),
+                                ty::Adt(adt, _) if Some(adt.did()) == self.tcx.lang_items().string()
+                            )
                     }
+                    ty::Adt(adt, _) => Some(adt.did()) == self.tcx.lang_items().string(),
+                    _ => false,
+                };
+                if is_string_or_ref_str && item_name.name == sym::iter {
+                    err.span_suggestion_verbose(
+                        item_name.span,
+                        "because of the in-memory representation of `&str`, to obtain \
+                         an `Iterator` over each of its codepoint use method `chars`",
+                        "chars",
+                        Applicability::MachineApplicable,
+                    );
                 }
-
-                if item_name.name == sym::as_str && rcvr_ty.peel_refs().is_str() {
-                    let msg = "remove this method call";
-                    let mut fallback_span = true;
-                    if let SelfSource::MethodCall(expr) = source {
-                        let call_expr =
-                            self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id));
-                        if let Some(span) = call_expr.span.trim_start(expr.span) {
-                            err.span_suggestion(span, msg, "", Applicability::MachineApplicable);
-                            fallback_span = false;
-                        }
-                    }
-                    if fallback_span {
-                        err.span_label(span, msg);
-                    }
-                } else if let Some(lev_candidate) = lev_candidate {
-                    // Don't emit a suggestion if we found an actual method
-                    // that had unsatisfied trait bounds
-                    if unsatisfied_predicates.is_empty() {
-                        let def_kind = lev_candidate.kind.as_def_kind();
-                        // Methods are defined within the context of a struct and their first parameter is always self,
-                        // which represents the instance of the struct the method is being called on
-                        // Associated functions don’t take self as a parameter and
-                        // they are not methods because they don’t have an instance of the struct to work with.
-                        if def_kind == DefKind::AssocFn && lev_candidate.fn_has_self_parameter {
-                            err.span_suggestion(
-                                span,
-                                &format!("there is a method with a similar name",),
-                                lev_candidate.name,
-                                Applicability::MaybeIncorrect,
-                            );
+                if let ty::Adt(adt, _) = rcvr_ty.kind() {
+                    let mut inherent_impls_candidate = self
+                        .tcx
+                        .inherent_impls(adt.did())
+                        .iter()
+                        .copied()
+                        .filter(|def_id| {
+                            if let Some(assoc) = self.associated_value(*def_id, item_name) {
+                                // Check for both mode is the same so we avoid suggesting
+                                // incorrect associated item.
+                                match (mode, assoc.fn_has_self_parameter, source) {
+                                    (Mode::MethodCall, true, SelfSource::MethodCall(_)) => {
+                                        // We check that the suggest type is actually
+                                        // different from the received one
+                                        // So we avoid suggestion method with Box<Self>
+                                        // for instance
+                                        self.tcx.at(span).type_of(*def_id) != rcvr_ty
+                                            && self.tcx.at(span).type_of(*def_id) != rcvr_ty
+                                    }
+                                    (Mode::Path, false, _) => true,
+                                    _ => false,
+                                }
+                            } else {
+                                false
+                            }
+                        })
+                        .collect::<Vec<_>>();
+                    if !inherent_impls_candidate.is_empty() {
+                        inherent_impls_candidate.sort();
+                        inherent_impls_candidate.dedup();
+
+                        // number of type to shows at most.
+                        let limit = if inherent_impls_candidate.len() == 5 { 5 } else { 4 };
+                        let type_candidates = inherent_impls_candidate
+                            .iter()
+                            .take(limit)
+                            .map(|impl_item| {
+                                format!("- `{}`", self.tcx.at(span).type_of(*impl_item))
+                            })
+                            .collect::<Vec<_>>()
+                            .join("\n");
+                        let additional_types = if inherent_impls_candidate.len() > limit {
+                            format!("\nand {} more types", inherent_impls_candidate.len() - limit)
                         } else {
-                            err.span_suggestion(
-                                span,
-                                &format!(
-                                    "there is {} {} with a similar name",
-                                    def_kind.article(),
-                                    def_kind.descr(lev_candidate.def_id),
-                                ),
-                                lev_candidate.name,
-                                Applicability::MaybeIncorrect,
-                            );
-                        }
+                            "".to_string()
+                        };
+                        err.note(&format!(
+                            "the {item_kind} was found for\n{}{}",
+                            type_candidates, additional_types
+                        ));
                     }
                 }
+            } else {
+                let ty_str =
+                    if ty_str.len() > 50 { String::new() } else { format!("on `{ty_str}` ") };
+                err.span_label(
+                    span,
+                    format!("{item_kind} cannot be called {ty_str}due to unsatisfied trait bounds"),
+                );
+            }
+        };
 
-                self.check_for_deref_method(&mut err, source, rcvr_ty, item_name);
-
-                return Some(err);
+        // If the method name is the name of a field with a function or closure type,
+        // give a helping note that it has to be called as `(x.f)(...)`.
+        if let SelfSource::MethodCall(expr) = source {
+            if !self.suggest_calling_field_as_fn(span, rcvr_ty, expr, item_name, &mut err)
+                && lev_candidate.is_none()
+                && !custom_span_label
+            {
+                label_span_not_found(&mut err);
             }
+        } else if !custom_span_label {
+            label_span_not_found(&mut err);
+        }
 
-            MethodError::Ambiguity(mut sources) => {
-                let mut err = struct_span_err!(
-                    self.sess(),
-                    item_name.span,
-                    E0034,
-                    "multiple applicable items in scope"
-                );
-                err.span_label(item_name.span, format!("multiple `{}` found", item_name));
+        // Don't suggest (for example) `expr.field.clone()` if `expr.clone()`
+        // can't be called due to `typeof(expr): Clone` not holding.
+        if unsatisfied_predicates.is_empty() {
+            self.suggest_calling_method_on_field(
+                &mut err,
+                source,
+                span,
+                rcvr_ty,
+                item_name,
+                expected.only_has_type(self),
+            );
+        }
 
-                report_candidates(span, &mut err, &mut sources, Some(sugg_span));
-                err.emit();
-            }
+        self.check_for_inner_self(&mut err, source, rcvr_ty, item_name);
 
-            MethodError::PrivateMatch(kind, def_id, out_of_scope_traits) => {
-                let kind = kind.descr(def_id);
-                let mut err = struct_span_err!(
-                    self.tcx.sess,
-                    item_name.span,
-                    E0624,
-                    "{} `{}` is private",
-                    kind,
-                    item_name
+        bound_spans.sort();
+        bound_spans.dedup();
+        for (span, msg) in bound_spans.into_iter() {
+            err.span_label(span, &msg);
+        }
+
+        if rcvr_ty.is_numeric() && rcvr_ty.is_fresh() || restrict_type_params {
+        } else {
+            self.suggest_traits_to_import(
+                &mut err,
+                span,
+                rcvr_ty,
+                item_name,
+                args.map(|(_, args)| args.len() + 1),
+                source,
+                no_match_data.out_of_scope_traits.clone(),
+                &unsatisfied_predicates,
+                &static_candidates,
+                unsatisfied_bounds,
+                expected.only_has_type(self),
+            );
+        }
+
+        // Don't emit a suggestion if we found an actual method
+        // that had unsatisfied trait bounds
+        if unsatisfied_predicates.is_empty() && rcvr_ty.is_enum() {
+            let adt_def = rcvr_ty.ty_adt_def().expect("enum is not an ADT");
+            if let Some(suggestion) = lev_distance::find_best_match_for_name(
+                &adt_def.variants().iter().map(|s| s.name).collect::<Vec<_>>(),
+                item_name.name,
+                None,
+            ) {
+                err.span_suggestion(
+                    span,
+                    "there is a variant with a similar name",
+                    suggestion,
+                    Applicability::MaybeIncorrect,
                 );
-                err.span_label(item_name.span, &format!("private {}", kind));
-                let sp = self
-                    .tcx
-                    .hir()
-                    .span_if_local(def_id)
-                    .unwrap_or_else(|| self.tcx.def_span(def_id));
-                err.span_label(sp, &format!("private {} defined here", kind));
-                self.suggest_valid_traits(&mut err, out_of_scope_traits);
-                err.emit();
             }
+        }
 
-            MethodError::IllegalSizedBound(candidates, needs_mut, bound_span) => {
-                let msg = format!("the `{}` method cannot be invoked on a trait object", item_name);
-                let mut err = self.sess().struct_span_err(span, &msg);
-                err.span_label(bound_span, "this has a `Sized` requirement");
-                if !candidates.is_empty() {
-                    let help = format!(
-                        "{an}other candidate{s} {were} found in the following trait{s}, perhaps \
-                         add a `use` for {one_of_them}:",
-                        an = if candidates.len() == 1 { "an" } else { "" },
-                        s = pluralize!(candidates.len()),
-                        were = pluralize!("was", candidates.len()),
-                        one_of_them = if candidates.len() == 1 { "it" } else { "one_of_them" },
+        if item_name.name == sym::as_str && rcvr_ty.peel_refs().is_str() {
+            let msg = "remove this method call";
+            let mut fallback_span = true;
+            if let SelfSource::MethodCall(expr) = source {
+                let call_expr = self.tcx.hir().expect_expr(self.tcx.hir().parent_id(expr.hir_id));
+                if let Some(span) = call_expr.span.trim_start(expr.span) {
+                    err.span_suggestion(span, msg, "", Applicability::MachineApplicable);
+                    fallback_span = false;
+                }
+            }
+            if fallback_span {
+                err.span_label(span, msg);
+            }
+        } else if let Some(lev_candidate) = lev_candidate {
+            // Don't emit a suggestion if we found an actual method
+            // that had unsatisfied trait bounds
+            if unsatisfied_predicates.is_empty() {
+                let def_kind = lev_candidate.kind.as_def_kind();
+                // Methods are defined within the context of a struct and their first parameter is always self,
+                // which represents the instance of the struct the method is being called on
+                // Associated functions don’t take self as a parameter and
+                // they are not methods because they don’t have an instance of the struct to work with.
+                if def_kind == DefKind::AssocFn && lev_candidate.fn_has_self_parameter {
+                    err.span_suggestion(
+                        span,
+                        "there is a method with a similar name",
+                        lev_candidate.name,
+                        Applicability::MaybeIncorrect,
+                    );
+                } else {
+                    err.span_suggestion(
+                        span,
+                        &format!(
+                            "there is {} {} with a similar name",
+                            def_kind.article(),
+                            def_kind.descr(lev_candidate.def_id),
+                        ),
+                        lev_candidate.name,
+                        Applicability::MaybeIncorrect,
                     );
-                    self.suggest_use_candidates(&mut err, help, candidates);
                 }
-                if let ty::Ref(region, t_type, mutability) = rcvr_ty.kind() {
-                    if needs_mut {
-                        let trait_type = self.tcx.mk_ref(
-                            *region,
-                            ty::TypeAndMut { ty: *t_type, mutbl: mutability.invert() },
+            }
+        }
+
+        self.check_for_deref_method(&mut err, source, rcvr_ty, item_name, expected);
+        return Some(err);
+    }
+
+    fn note_candidates_on_method_error(
+        &self,
+        rcvr_ty: Ty<'tcx>,
+        item_name: Ident,
+        args: Option<(&'tcx hir::Expr<'tcx>, &'tcx [hir::Expr<'tcx>])>,
+        span: Span,
+        err: &mut Diagnostic,
+        sources: &mut Vec<CandidateSource>,
+        sugg_span: Option<Span>,
+    ) {
+        sources.sort();
+        sources.dedup();
+        // Dynamic limit to avoid hiding just one candidate, which is silly.
+        let limit = if sources.len() == 5 { 5 } else { 4 };
+
+        for (idx, source) in sources.iter().take(limit).enumerate() {
+            match *source {
+                CandidateSource::Impl(impl_did) => {
+                    // Provide the best span we can. Use the item, if local to crate, else
+                    // the impl, if local to crate (item may be defaulted), else nothing.
+                    let Some(item) = self.associated_value(impl_did, item_name).or_else(|| {
+                        let impl_trait_ref = self.tcx.impl_trait_ref(impl_did)?;
+                        self.associated_value(impl_trait_ref.skip_binder().def_id, item_name)
+                    }) else {
+                        continue;
+                    };
+
+                    let note_span = if item.def_id.is_local() {
+                        Some(self.tcx.def_span(item.def_id))
+                    } else if impl_did.is_local() {
+                        Some(self.tcx.def_span(impl_did))
+                    } else {
+                        None
+                    };
+
+                    let impl_ty = self.tcx.at(span).type_of(impl_did);
+
+                    let insertion = match self.tcx.impl_trait_ref(impl_did) {
+                        None => String::new(),
+                        Some(trait_ref) => {
+                            format!(
+                                " of the trait `{}`",
+                                self.tcx.def_path_str(trait_ref.skip_binder().def_id)
+                            )
+                        }
+                    };
+
+                    let (note_str, idx) = if sources.len() > 1 {
+                        (
+                            format!(
+                                "candidate #{} is defined in an impl{} for the type `{}`",
+                                idx + 1,
+                                insertion,
+                                impl_ty,
+                            ),
+                            Some(idx + 1),
+                        )
+                    } else {
+                        (
+                            format!(
+                                "the candidate is defined in an impl{} for the type `{}`",
+                                insertion, impl_ty,
+                            ),
+                            None,
+                        )
+                    };
+                    if let Some(note_span) = note_span {
+                        // We have a span pointing to the method. Show note with snippet.
+                        err.span_note(note_span, &note_str);
+                    } else {
+                        err.note(&note_str);
+                    }
+                    if let Some(sugg_span) = sugg_span
+                        && let Some(trait_ref) = self.tcx.impl_trait_ref(impl_did) {
+                        let path = self.tcx.def_path_str(trait_ref.skip_binder().def_id);
+
+                        let ty = match item.kind {
+                            ty::AssocKind::Const | ty::AssocKind::Type => rcvr_ty,
+                            ty::AssocKind::Fn => self
+                                .tcx
+                                .fn_sig(item.def_id)
+                                .inputs()
+                                .skip_binder()
+                                .get(0)
+                                .filter(|ty| ty.is_region_ptr() && !rcvr_ty.is_region_ptr())
+                                .copied()
+                                .unwrap_or(rcvr_ty),
+                        };
+                        print_disambiguation_help(
+                            item_name,
+                            args,
+                            err,
+                            path,
+                            ty,
+                            item.kind,
+                            item.def_id,
+                            sugg_span,
+                            idx,
+                            self.tcx.sess.source_map(),
+                            item.fn_has_self_parameter,
+                        );
+                    }
+                }
+                CandidateSource::Trait(trait_did) => {
+                    let Some(item) = self.associated_value(trait_did, item_name) else { continue };
+                    let item_span = self.tcx.def_span(item.def_id);
+                    let idx = if sources.len() > 1 {
+                        let msg = &format!(
+                            "candidate #{} is defined in the trait `{}`",
+                            idx + 1,
+                            self.tcx.def_path_str(trait_did)
+                        );
+                        err.span_note(item_span, msg);
+                        Some(idx + 1)
+                    } else {
+                        let msg = &format!(
+                            "the candidate is defined in the trait `{}`",
+                            self.tcx.def_path_str(trait_did)
+                        );
+                        err.span_note(item_span, msg);
+                        None
+                    };
+                    if let Some(sugg_span) = sugg_span {
+                        let path = self.tcx.def_path_str(trait_did);
+                        print_disambiguation_help(
+                            item_name,
+                            args,
+                            err,
+                            path,
+                            rcvr_ty,
+                            item.kind,
+                            item.def_id,
+                            sugg_span,
+                            idx,
+                            self.tcx.sess.source_map(),
+                            item.fn_has_self_parameter,
                         );
-                        err.note(&format!("you need `{}` instead of `{}`", trait_type, rcvr_ty));
                     }
                 }
-                err.emit();
             }
-
-            MethodError::BadReturnType => bug!("no return type expectations but got BadReturnType"),
         }
-        None
+        if sources.len() > limit {
+            err.note(&format!("and {} others", sources.len() - limit));
+        }
     }
 
     /// Suggest calling `Ty::method` if `.method()` isn't found because the method
@@ -1244,7 +1362,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         Applicability::MachineApplicable,
                     );
                 } else {
-                    let call_expr = tcx.hir().expect_expr(tcx.hir().get_parent_node(expr.hir_id));
+                    let call_expr = tcx.hir().expect_expr(tcx.hir().parent_id(expr.hir_id));
 
                     if let Some(span) = call_expr.span.trim_start(item_name.span) {
                         err.span_suggestion(
@@ -1318,13 +1436,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     let range_ty =
                         self.tcx.bound_type_of(range_def_id).subst(self.tcx, &[actual.into()]);
 
-                    let pick = self.probe_for_name(
-                        Mode::MethodCall,
+                    let pick = self.lookup_probe_for_diagnostic(
                         item_name,
-                        IsSuggestion(true),
                         range_ty,
-                        expr.hir_id,
+                        expr,
                         ProbeScope::AllTraits,
+                        None,
                     );
                     if pick.is_ok() {
                         let range_span = parent_expr.span.with_hi(expr.span.hi());
@@ -1426,7 +1543,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let filename = tcx.sess.source_map().span_to_filename(span);
 
                         let parent_node =
-                            self.tcx.hir().get(self.tcx.hir().get_parent_node(hir_id));
+                            self.tcx.hir().get_parent(hir_id);
                         let msg = format!(
                             "you must specify a type for this binding, like `{}`",
                             concrete_type,
@@ -1499,16 +1616,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut visitor = LetVisitor { result: None, ident_name: seg1.ident.name };
         visitor.visit_body(&body);
 
-        let parent = self.tcx.hir().get_parent_node(seg1.hir_id);
+        let parent = self.tcx.hir().parent_id(seg1.hir_id);
         if let Some(Node::Expr(call_expr)) = self.tcx.hir().find(parent)
             && let Some(expr) = visitor.result
             && let Some(self_ty) = self.node_ty_opt(expr.hir_id)
         {
-            let probe = self.lookup_probe(
+            let probe = self.lookup_probe_for_diagnostic(
                 seg2.ident,
                 self_ty,
                 call_expr,
                 ProbeScope::TraitsInScope,
+                None,
             );
             if probe.is_ok() {
                 let sm = self.infcx.tcx.sess.source_map();
@@ -1531,13 +1649,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         span: Span,
         actual: Ty<'tcx>,
         item_name: Ident,
+        return_type: Option<Ty<'tcx>>,
     ) {
         if let SelfSource::MethodCall(expr) = source
         && let mod_id = self.tcx.parent_module(expr.hir_id).to_def_id()
         && let Some((fields, substs)) =
             self.get_field_candidates_considering_privacy(span, actual, mod_id)
         {
-            let call_expr = self.tcx.hir().expect_expr(self.tcx.hir().get_parent_node(expr.hir_id));
+            let call_expr = self.tcx.hir().expect_expr(self.tcx.hir().parent_id(expr.hir_id));
 
             let lang_items = self.tcx.lang_items();
             let never_mention_traits = [
@@ -1554,11 +1673,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     self.check_for_nested_field_satisfying(
                         span,
                         &|_, field_ty| {
-                            self.lookup_probe(
+                            self.lookup_probe_for_diagnostic(
                                 item_name,
                                 field_ty,
                                 call_expr,
                                 ProbeScope::TraitsInScope,
+                                return_type,
                             )
                             .map_or(false, |pick| {
                                 !never_mention_traits
@@ -1607,7 +1727,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) {
         let tcx = self.tcx;
         let SelfSource::MethodCall(expr) = source else { return; };
-        let call_expr = tcx.hir().expect_expr(tcx.hir().get_parent_node(expr.hir_id));
+        let call_expr = tcx.hir().expect_expr(tcx.hir().parent_id(expr.hir_id));
 
         let ty::Adt(kind, substs) = actual.kind() else { return; };
         match kind.adt_kind() {
@@ -1624,9 +1744,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             return None;
                         }
 
-                        self.lookup_probe(item_name, field_ty, call_expr, ProbeScope::TraitsInScope)
-                            .ok()
-                            .map(|pick| (variant, field, pick))
+                        self.lookup_probe_for_diagnostic(
+                            item_name,
+                            field_ty,
+                            call_expr,
+                            ProbeScope::TraitsInScope,
+                            None,
+                        )
+                        .ok()
+                        .map(|pick| (variant, field, pick))
                     })
                     .collect();
 
@@ -1690,11 +1816,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ty::AdtKind::Struct | ty::AdtKind::Union => {
                 let [first] = ***substs else { return; };
                 let ty::GenericArgKind::Type(ty) = first.unpack() else { return; };
-                let Ok(pick) = self.lookup_probe(
+                let Ok(pick) = self.lookup_probe_for_diagnostic(
                     item_name,
                     ty,
                     call_expr,
                     ProbeScope::TraitsInScope,
+                    None,
                 )  else { return; };
 
                 let name = self.ty_to_value_string(actual);
@@ -1843,7 +1970,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.suggest_derive(err, &preds);
     }
 
-    fn suggest_derive(
+    pub fn suggest_derive(
         &self,
         err: &mut Diagnostic,
         unsatisfied_predicates: &[(
@@ -1853,7 +1980,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         )],
     ) {
         let mut derives = Vec::<(String, Span, Symbol)>::new();
-        let mut traits = Vec::<Span>::new();
+        let mut traits = Vec::new();
         for (pred, _, _) in unsatisfied_predicates {
             let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = pred.kind().skip_binder() else { continue };
             let adt = match trait_pred.self_ty().ty_adt_def() {
@@ -1892,10 +2019,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                     derives.push((self_name, self_span, diagnostic_name));
                 } else {
-                    traits.push(self.tcx.def_span(trait_pred.def_id()));
+                    traits.push(trait_pred.def_id());
                 }
             } else {
-                traits.push(self.tcx.def_span(trait_pred.def_id()));
+                traits.push(trait_pred.def_id());
             }
         }
         traits.sort();
@@ -1918,10 +2045,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let len = traits.len();
         if len > 0 {
-            let span: MultiSpan = traits.into();
+            let span =
+                MultiSpan::from_spans(traits.iter().map(|&did| self.tcx.def_span(did)).collect());
+            let mut names = format!("`{}`", self.tcx.def_path_str(traits[0]));
+            for (i, &did) in traits.iter().enumerate().skip(1) {
+                if len > 2 {
+                    names.push_str(", ");
+                }
+                if i == len - 1 {
+                    names.push_str(" and ");
+                }
+                names.push('`');
+                names.push_str(&self.tcx.def_path_str(did));
+                names.push('`');
+            }
             err.span_note(
                 span,
-                &format!("the following trait{} must be implemented", pluralize!(len),),
+                &format!("the trait{} {} must be implemented", pluralize!(len), names),
             );
         }
 
@@ -1941,12 +2081,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self_source: SelfSource<'tcx>,
         rcvr_ty: Ty<'tcx>,
         item_name: Ident,
+        expected: Expectation<'tcx>,
     ) {
         let SelfSource::QPath(ty) = self_source else { return; };
         for (deref_ty, _) in self.autoderef(rustc_span::DUMMY_SP, rcvr_ty).skip(1) {
             if let Ok(pick) = self.probe_for_name(
                 Mode::Path,
                 item_name,
+                expected.only_has_type(self),
                 IsSuggestion(true),
                 deref_ty,
                 ty.hir_id,
@@ -1969,7 +2111,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         | ty::Float(_)
                         | ty::Adt(_, _)
                         | ty::Str
-                        | ty::Projection(_)
+                        | ty::Alias(ty::Projection, _)
                         | ty::Param(_) => format!("{deref_ty}"),
                         // we need to test something like  <&[_]>::len or <(&[u32])>::len
                         // and Vec::function();
@@ -2011,12 +2153,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         ty: Ty<'tcx>,
         call: &hir::Expr<'_>,
         span: Span,
+        return_type: Option<Ty<'tcx>>,
     ) {
         let output_ty = match self.get_impl_future_output_ty(ty) {
             Some(output_ty) => self.resolve_vars_if_possible(output_ty),
             _ => return,
         };
-        let method_exists = self.method_exists(item_name, output_ty, call.hir_id, true);
+        let method_exists =
+            self.method_exists(item_name, output_ty, call.hir_id, true, return_type);
         debug!("suggest_await_before_method: is_method_exist={}", method_exists);
         if method_exists {
             err.span_suggestion_verbose(
@@ -2130,6 +2274,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         )],
         static_candidates: &[CandidateSource],
         unsatisfied_bounds: bool,
+        return_type: Option<Ty<'tcx>>,
     ) {
         let mut alt_rcvr_sugg = false;
         if let (SelfSource::MethodCall(rcvr), false) = (source, unsatisfied_bounds) {
@@ -2152,7 +2297,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 (self.tcx.mk_mut_ref(self.tcx.lifetimes.re_erased, rcvr_ty), "&mut "),
                 (self.tcx.mk_imm_ref(self.tcx.lifetimes.re_erased, rcvr_ty), "&"),
             ] {
-                match self.lookup_probe(item_name, *rcvr_ty, rcvr, ProbeScope::AllTraits) {
+                match self.lookup_probe_for_diagnostic(
+                    item_name,
+                    *rcvr_ty,
+                    rcvr,
+                    ProbeScope::AllTraits,
+                    return_type,
+                ) {
                     Ok(pick) => {
                         // If the method is defined for the receiver we have, it likely wasn't `use`d.
                         // We point at the method, but we just skip the rest of the check for arbitrary
@@ -2185,11 +2336,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     (self.tcx.mk_diagnostic_item(*rcvr_ty, sym::Rc), "Rc::new"),
                 ] {
                     if let Some(new_rcvr_t) = *rcvr_ty
-                        && let Ok(pick) = self.lookup_probe(
+                        && let Ok(pick) = self.lookup_probe_for_diagnostic(
                             item_name,
                             new_rcvr_t,
                             rcvr,
                             ProbeScope::AllTraits,
+                            return_type,
                         )
                     {
                         debug!("try_alt_rcvr: pick candidate {:?}", pick);
@@ -2269,11 +2421,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             t.def_id() == info.def_id
                         }
                         ty::PredicateKind::Clause(ty::Clause::Projection(p)) => {
-                            p.projection_ty.item_def_id == info.def_id
+                            p.projection_ty.def_id == info.def_id
                         }
                         _ => false,
                     }
                 }) && (type_is_local || info.def_id.is_local())
+                    && !self.tcx.trait_is_auto(info.def_id)
                     && self
                         .associated_value(info.def_id, item_name)
                         .filter(|item| {
@@ -2466,7 +2619,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             self.tcx.impl_polarity(*imp_did) == ty::ImplPolarity::Negative
                         })
                         .any(|imp_did| {
-                            let imp = self.tcx.impl_trait_ref(imp_did).unwrap();
+                            let imp = self.tcx.impl_trait_ref(imp_did).unwrap().subst_identity();
                             let imp_simp =
                                 simplify_type(self.tcx, imp.self_ty(), TreatParams::AsPlaceholder);
                             imp_simp.map_or(false, |s| s == simp_rcvr_ty)
@@ -2547,14 +2700,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         found: Ty<'tcx>,
         expected: Ty<'tcx>,
     ) -> bool {
-        let Some((_def_id_or_name, output, _inputs)) = self.extract_callable_info(expr, found)
-        else { return false; };
+        let Some((_def_id_or_name, output, _inputs)) =
+            self.extract_callable_info(found) else {
+                return false;
+        };
 
         if !self.can_coerce(output, expected) {
             return false;
         }
 
-        let parent = self.tcx.hir().get_parent_node(expr.hir_id);
+        let parent = self.tcx.hir().parent_id(expr.hir_id);
         if  let Some(Node::Expr(call_expr)) = self.tcx.hir().find(parent) &&
             let hir::ExprKind::MethodCall(
                 hir::PathSegment { ident: method_name, .. },
@@ -2567,11 +2722,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 name: Symbol::intern(&format!("{}_else", method_name.as_str())),
                 span: method_name.span,
             };
-            let probe = self.lookup_probe(
+            let probe = self.lookup_probe_for_diagnostic(
                 new_name,
                 self_ty,
                 self_expr,
                 ProbeScope::TraitsInScope,
+                Some(expected),
             );
 
             // check the method arguments number
diff --git a/compiler/rustc_hir_typeck/src/op.rs b/compiler/rustc_hir_typeck/src/op.rs
index b12d84af4..78cea1f4d 100644
--- a/compiler/rustc_hir_typeck/src/op.rs
+++ b/compiler/rustc_hir_typeck/src/op.rs
@@ -12,14 +12,16 @@ use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability,
 };
 use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self, DefIdTree, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitable};
+use rustc_middle::ty::{
+    self, DefIdTree, IsSuggestable, Ty, TyCtxt, TypeFolder, TypeSuperFoldable, TypeVisitable,
+};
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::error_reporting::suggestions::TypeErrCtxtExt as _;
-use rustc_trait_selection::traits::FulfillmentError;
+use rustc_trait_selection::traits::{self, FulfillmentError};
 use rustc_type_ir::sty::TyKind::*;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
@@ -48,8 +50,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 if self
                     .lookup_op_method(
                         lhs_deref_ty,
-                        Some(rhs_ty),
-                        Some(rhs),
+                        Some((rhs, rhs_ty)),
                         Op::Binary(op, IsAssign::Yes),
                         expected,
                     )
@@ -60,8 +61,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     if self
                         .lookup_op_method(
                             lhs_ty,
-                            Some(rhs_ty),
-                            Some(rhs),
+                            Some((rhs, rhs_ty)),
                             Op::Binary(op, IsAssign::Yes),
                             expected,
                         )
@@ -248,8 +248,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let result = self.lookup_op_method(
             lhs_ty,
-            Some(rhs_ty_var),
-            Some(rhs_expr),
+            Some((rhs_expr, rhs_ty_var)),
             Op::Binary(op, is_assign),
             expected,
         );
@@ -382,8 +381,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     if self
                         .lookup_op_method(
                             lhs_deref_ty,
-                            Some(rhs_ty),
-                            Some(rhs_expr),
+                            Some((rhs_expr, rhs_ty)),
                             Op::Binary(op, is_assign),
                             expected,
                         )
@@ -410,8 +408,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let is_compatible = |lhs_ty, rhs_ty| {
                     self.lookup_op_method(
                         lhs_ty,
-                        Some(rhs_ty),
-                        Some(rhs_expr),
+                        Some((rhs_expr, rhs_ty)),
                         Op::Binary(op, is_assign),
                         expected,
                     )
@@ -471,8 +468,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let errors = self
                             .lookup_op_method(
                                 lhs_ty,
-                                Some(rhs_ty),
-                                Some(rhs_expr),
+                                Some((rhs_expr, rhs_ty)),
                                 Op::Binary(op, is_assign),
                                 expected,
                             )
@@ -492,6 +488,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                             if let Some(output_def_id) = output_def_id
                                                 && let Some(trait_def_id) = trait_def_id
                                                 && self.tcx.parent(output_def_id) == trait_def_id
+                                                && output_ty.is_suggestable(self.tcx, false)
                                             {
                                                 Some(("Output", *output_ty))
                                             } else {
@@ -625,7 +622,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expected: Expectation<'tcx>,
     ) -> Ty<'tcx> {
         assert!(op.is_by_value());
-        match self.lookup_op_method(operand_ty, None, None, Op::Unary(op, ex.span), expected) {
+        match self.lookup_op_method(operand_ty, None, Op::Unary(op, ex.span), expected) {
             Ok(method) => {
                 self.write_method_call(ex.hir_id, method);
                 method.sig.output()
@@ -660,7 +657,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         }
                     }
 
-                    let sp = self.tcx.sess.source_map().start_point(ex.span);
+                    let sp = self.tcx.sess.source_map().start_point(ex.span).with_parent(None);
                     if let Some(sp) =
                         self.tcx.sess.parse_sess.ambiguous_block_expr_parse.borrow().get(&sp)
                     {
@@ -712,8 +709,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     fn lookup_op_method(
         &self,
         lhs_ty: Ty<'tcx>,
-        other_ty: Option<Ty<'tcx>>,
-        other_ty_expr: Option<&'tcx hir::Expr<'tcx>>,
+        opt_rhs: Option<(&'tcx hir::Expr<'tcx>, Ty<'tcx>)>,
         op: Op,
         expected: Expectation<'tcx>,
     ) -> Result<MethodCallee<'tcx>, Vec<FulfillmentError<'tcx>>> {
@@ -742,20 +738,27 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 Op::Unary(..) => 0,
             },
         ) {
+            self.tcx
+                .sess
+                .delay_span_bug(span, "operator didn't have the right number of generic args");
             return Err(vec![]);
         }
 
         let opname = Ident::with_dummy_span(opname);
+        let input_types =
+            opt_rhs.as_ref().map(|(_, ty)| std::slice::from_ref(ty)).unwrap_or_default();
+        let cause = self.cause(
+            span,
+            traits::BinOp {
+                rhs_span: opt_rhs.map(|(expr, _)| expr.span),
+                is_lit: opt_rhs
+                    .map_or(false, |(expr, _)| matches!(expr.kind, hir::ExprKind::Lit(_))),
+                output_ty: expected.only_has_type(self),
+            },
+        );
+
         let method = trait_did.and_then(|trait_did| {
-            self.lookup_op_method_in_trait(
-                span,
-                opname,
-                trait_did,
-                lhs_ty,
-                other_ty,
-                other_ty_expr,
-                expected,
-            )
+            self.lookup_method_in_trait(cause.clone(), opname, trait_did, lhs_ty, Some(input_types))
         });
 
         match (method, trait_did) {
@@ -766,14 +769,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
             (None, None) => Err(vec![]),
             (None, Some(trait_did)) => {
-                let (obligation, _) = self.obligation_for_op_method(
-                    span,
-                    trait_did,
-                    lhs_ty,
-                    other_ty,
-                    other_ty_expr,
-                    expected,
-                );
+                let (obligation, _) =
+                    self.obligation_for_method(cause, trait_did, lhs_ty, Some(input_types));
                 Err(rustc_trait_selection::traits::fully_solve_obligation(self, obligation))
             }
         }
@@ -904,7 +901,7 @@ enum Op {
 }
 
 /// Dereferences a single level of immutable referencing.
-fn deref_ty_if_possible<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
+fn deref_ty_if_possible(ty: Ty<'_>) -> Ty<'_> {
     match ty.kind() {
         ty::Ref(_, ty, hir::Mutability::Not) => *ty,
         _ => ty,
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs
index decd317d9..467992452 100644
--- a/compiler/rustc_hir_typeck/src/pat.rs
+++ b/compiler/rustc_hir_typeck/src/pat.rs
@@ -1,4 +1,4 @@
-use crate::FnCtxt;
+use crate::{FnCtxt, RawTy};
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{
@@ -386,7 +386,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Byte string patterns behave the same way as array patterns
         // They can denote both statically and dynamically-sized byte arrays.
         let mut pat_ty = ty;
-        if let hir::ExprKind::Lit(Spanned { node: ast::LitKind::ByteStr(_), .. }) = lt.kind {
+        if let hir::ExprKind::Lit(Spanned { node: ast::LitKind::ByteStr(..), .. }) = lt.kind {
             let expected = self.structurally_resolved_type(span, expected);
             if let ty::Ref(_, inner_ty, _) = expected.kind()
                 && matches!(inner_ty.kind(), ty::Slice(_))
@@ -553,6 +553,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             (lhs, Some((true, rhs_ty, rhs_sp))) => one_side_err(rhs_sp, rhs_ty, lhs),
             _ => span_bug!(span, "Impossible, verified above."),
         }
+        if (lhs, rhs).references_error() {
+            err.downgrade_to_delayed_bug();
+        }
         if self.tcx.sess.teach(&err.get_code().unwrap()) {
             err.note(
                 "In a match expression, only numbers and characters can be matched \
@@ -692,7 +695,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let tcx = self.tcx;
         if let PatKind::Ref(inner, mutbl) = pat.kind
         && let PatKind::Binding(_, _, binding, ..) = inner.kind {
-            let binding_parent_id = tcx.hir().get_parent_node(pat.hir_id);
+            let binding_parent_id = tcx.hir().parent_id(pat.hir_id);
             let binding_parent = tcx.hir().get(binding_parent_id);
             debug!(?inner, ?pat, ?binding_parent);
 
@@ -758,6 +761,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         err.span_note(sp, format!("{msg}: `{sugg}`"));
                     }
                 }
+                hir::Node::Pat(pt) if let PatKind::TupleStruct(_, pat_arr, _) = pt.kind => {
+                    for i in pat_arr.iter() {
+                        if let PatKind::Ref(the_ref, _) = i.kind
+                        && let PatKind::Binding(mt, _, ident, _) = the_ref.kind {
+                            let hir::BindingAnnotation(_, mtblty) = mt;
+                            err.span_suggestion_verbose(
+                                i.span,
+                                format!("consider removing `&{mutability}` from the pattern"),
+                                mtblty.prefix_str().to_string() + &ident.name.to_string(),
+                                Applicability::MaybeIncorrect,
+                            );
+                        }
+                    }
+                    if let Some((sp, msg, sugg)) = mut_var_suggestion {
+                        err.span_note(sp, format!("{msg}: `{sugg}`"));
+                    }
+                }
                 hir::Node::Param(_) | hir::Node::Arm(_) | hir::Node::Pat(_) => {
                     // rely on match ergonomics or it might be nested `&&pat`
                     err.span_suggestion_verbose(
@@ -839,7 +859,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         pat: &Pat<'tcx>,
         qpath: &hir::QPath<'_>,
-        path_resolution: (Res, Option<Ty<'tcx>>, &'tcx [hir::PathSegment<'tcx>]),
+        path_resolution: (Res, Option<RawTy<'tcx>>, &'tcx [hir::PathSegment<'tcx>]),
         expected: Ty<'tcx>,
         ti: TopInfo<'tcx>,
     ) -> Ty<'tcx> {
@@ -936,7 +956,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         res.descr(),
                     ),
                 );
-                match self.tcx.hir().get(self.tcx.hir().get_parent_node(pat.hir_id)) {
+                match self.tcx.hir().get_parent(pat.hir_id) {
                     hir::Node::PatField(..) => {
                         e.span_suggestion_verbose(
                             ident.span.shrink_to_hi(),
@@ -1013,7 +1033,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let (res, opt_ty, segments) =
             self.resolve_ty_and_res_fully_qualified_call(qpath, pat.hir_id, pat.span);
         if res == Res::Err {
-            let e = tcx.sess.delay_span_bug(pat.span, "`Res:Err` but no error emitted");
+            let e = tcx.sess.delay_span_bug(pat.span, "`Res::Err` but no error emitted");
             self.set_tainted_by_errors(e);
             on_error(e);
             return tcx.ty_error_with_guaranteed(e);
@@ -1921,7 +1941,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) -> Ty<'tcx> {
         let tcx = self.tcx;
         let expected = self.shallow_resolve(expected);
-        let (rptr_ty, inner_ty) = if self.check_dereferenceable(pat.span, expected, inner) {
+        let (ref_ty, inner_ty) = if self.check_dereferenceable(pat.span, expected, inner) {
             // `demand::subtype` would be good enough, but using `eqtype` turns
             // out to be equally general. See (note_1) for details.
 
@@ -1936,9 +1956,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         kind: TypeVariableOriginKind::TypeInference,
                         span: inner.span,
                     });
-                    let rptr_ty = self.new_ref_ty(pat.span, mutbl, inner_ty);
-                    debug!("check_pat_ref: demanding {:?} = {:?}", expected, rptr_ty);
-                    let err = self.demand_eqtype_pat_diag(pat.span, expected, rptr_ty, ti);
+                    let ref_ty = self.new_ref_ty(pat.span, mutbl, inner_ty);
+                    debug!("check_pat_ref: demanding {:?} = {:?}", expected, ref_ty);
+                    let err = self.demand_eqtype_pat_diag(pat.span, expected, ref_ty, ti);
 
                     // Look for a case like `fn foo(&foo: u32)` and suggest
                     // `fn foo(foo: &u32)`
@@ -1946,7 +1966,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         self.borrow_pat_suggestion(&mut err, pat);
                         err.emit();
                     }
-                    (rptr_ty, inner_ty)
+                    (ref_ty, inner_ty)
                 }
             }
         } else {
@@ -1954,7 +1974,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             (err, err)
         };
         self.check_pat(inner, inner_ty, def_bm, ti);
-        rptr_ty
+        ref_ty
     }
 
     /// Create a reference type with a fresh region variable.
@@ -2130,7 +2150,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             && let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
         {
             let ty = self.resolve_vars_if_possible(ti.expected);
-            let is_slice_or_array_or_vector = self.is_slice_or_array_or_vector(&mut err, snippet.clone(), ty);
+            let is_slice_or_array_or_vector = self.is_slice_or_array_or_vector(ty);
             match is_slice_or_array_or_vector.1.kind() {
                 ty::Adt(adt_def, _)
                     if self.tcx.is_diagnostic_item(sym::Option, adt_def.did())
@@ -2159,17 +2179,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err.emit();
     }
 
-    fn is_slice_or_array_or_vector(
-        &self,
-        err: &mut Diagnostic,
-        snippet: String,
-        ty: Ty<'tcx>,
-    ) -> (bool, Ty<'tcx>) {
+    fn is_slice_or_array_or_vector(&self, ty: Ty<'tcx>) -> (bool, Ty<'tcx>) {
         match ty.kind() {
             ty::Adt(adt_def, _) if self.tcx.is_diagnostic_item(sym::Vec, adt_def.did()) => {
                 (true, ty)
             }
-            ty::Ref(_, ty, _) => self.is_slice_or_array_or_vector(err, snippet, *ty),
+            ty::Ref(_, ty, _) => self.is_slice_or_array_or_vector(*ty),
             ty::Slice(..) | ty::Array(..) => (true, ty),
             _ => (false, ty),
         }
diff --git a/compiler/rustc_hir_typeck/src/place_op.rs b/compiler/rustc_hir_typeck/src/place_op.rs
index 952ea1488..ae0df5aa8 100644
--- a/compiler/rustc_hir_typeck/src/place_op.rs
+++ b/compiler/rustc_hir_typeck/src/place_op.rs
@@ -3,6 +3,7 @@ use crate::{has_expected_num_generic_args, FnCtxt, PlaceOp};
 use rustc_ast as ast;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
+use rustc_hir_analysis::autoderef::Autoderef;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::InferOk;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, OverloadedDeref, PointerCast};
@@ -10,7 +11,6 @@ use rustc_middle::ty::adjustment::{AllowTwoPhase, AutoBorrow, AutoBorrowMutabili
 use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
-use rustc_trait_selection::autoderef::Autoderef;
 use std::slice;
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
@@ -225,7 +225,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         imm_tr.and_then(|trait_did| {
             self.lookup_method_in_trait(
-                span,
+                self.misc(span),
                 Ident::with_dummy_span(imm_op),
                 trait_did,
                 base_ty,
@@ -264,7 +264,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         mut_tr.and_then(|trait_did| {
             self.lookup_method_in_trait(
-                span,
+                self.misc(span),
                 Ident::with_dummy_span(mut_op),
                 trait_did,
                 base_ty,
diff --git a/compiler/rustc_hir_typeck/src/upvar.rs b/compiler/rustc_hir_typeck/src/upvar.rs
index 0f4697201..e12a575d5 100644
--- a/compiler/rustc_hir_typeck/src/upvar.rs
+++ b/compiler/rustc_hir_typeck/src/upvar.rs
@@ -663,7 +663,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // fields of some type, the observable drop order will remain the same as it previously
         // was even though we're dropping each capture individually.
         // See https://github.com/rust-lang/project-rfc-2229/issues/42 and
-        // `src/test/ui/closures/2229_closure_analysis/preserve_field_drop_order.rs`.
+        // `tests/ui/closures/2229_closure_analysis/preserve_field_drop_order.rs`.
         for (_, captures) in &mut root_var_min_capture_list {
             captures.sort_by(|capture1, capture2| {
                 for (p1, p2) in capture1.place.projections.iter().zip(&capture2.place.projections) {
@@ -1675,7 +1675,7 @@ fn apply_capture_kind_on_capture_ty<'tcx>(
 }
 
 /// Returns the Span of where the value with the provided HirId would be dropped
-fn drop_location_span<'tcx>(tcx: TyCtxt<'tcx>, hir_id: hir::HirId) -> Span {
+fn drop_location_span(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> Span {
     let owner_id = tcx.hir().get_enclosing_scope(hir_id).unwrap();
 
     let owner_node = tcx.hir().get(owner_id);
@@ -1843,10 +1843,10 @@ fn restrict_precision_for_drop_types<'a, 'tcx>(
 /// - No projections are applied to raw pointers, since these require unsafe blocks. We capture
 ///   them completely.
 /// - No projections are applied on top of Union ADTs, since these require unsafe blocks.
-fn restrict_precision_for_unsafe<'tcx>(
-    mut place: Place<'tcx>,
+fn restrict_precision_for_unsafe(
+    mut place: Place<'_>,
     mut curr_mode: ty::UpvarCapture,
-) -> (Place<'tcx>, ty::UpvarCapture) {
+) -> (Place<'_>, ty::UpvarCapture) {
     if place.base_ty.is_unsafe_ptr() {
         truncate_place_to_len_and_update_capture_kind(&mut place, &mut curr_mode, 0);
     }
@@ -1876,10 +1876,10 @@ fn restrict_precision_for_unsafe<'tcx>(
 /// - No Index projections are captured, since arrays are captured completely.
 /// - No unsafe block is required to capture `place`
 /// Returns the truncated place and updated capture mode.
-fn restrict_capture_precision<'tcx>(
-    place: Place<'tcx>,
+fn restrict_capture_precision(
+    place: Place<'_>,
     curr_mode: ty::UpvarCapture,
-) -> (Place<'tcx>, ty::UpvarCapture) {
+) -> (Place<'_>, ty::UpvarCapture) {
     let (mut place, mut curr_mode) = restrict_precision_for_unsafe(place, curr_mode);
 
     if place.projections.is_empty() {
@@ -1904,10 +1904,10 @@ fn restrict_capture_precision<'tcx>(
 }
 
 /// Truncate deref of any reference.
-fn adjust_for_move_closure<'tcx>(
-    mut place: Place<'tcx>,
+fn adjust_for_move_closure(
+    mut place: Place<'_>,
     mut kind: ty::UpvarCapture,
-) -> (Place<'tcx>, ty::UpvarCapture) {
+) -> (Place<'_>, ty::UpvarCapture) {
     let first_deref = place.projections.iter().position(|proj| proj.kind == ProjectionKind::Deref);
 
     if let Some(idx) = first_deref {
@@ -1919,10 +1919,10 @@ fn adjust_for_move_closure<'tcx>(
 
 /// Adjust closure capture just that if taking ownership of data, only move data
 /// from enclosing stack frame.
-fn adjust_for_non_move_closure<'tcx>(
-    mut place: Place<'tcx>,
+fn adjust_for_non_move_closure(
+    mut place: Place<'_>,
     mut kind: ty::UpvarCapture,
-) -> (Place<'tcx>, ty::UpvarCapture) {
+) -> (Place<'_>, ty::UpvarCapture) {
     let contains_deref =
         place.projections.iter().position(|proj| proj.kind == ProjectionKind::Deref);
 
@@ -2225,10 +2225,10 @@ fn determine_place_ancestry_relation<'tcx>(
 ///     // it is constrained to `'a`
 /// }
 /// ```
-fn truncate_capture_for_optimization<'tcx>(
-    mut place: Place<'tcx>,
+fn truncate_capture_for_optimization(
+    mut place: Place<'_>,
     mut curr_mode: ty::UpvarCapture,
-) -> (Place<'tcx>, ty::UpvarCapture) {
+) -> (Place<'_>, ty::UpvarCapture) {
     let is_shared_ref = |ty: Ty<'_>| matches!(ty.kind(), ty::Ref(.., hir::Mutability::Not));
 
     // Find the right-most deref (if any). All the projections that come after this
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 52ffd286e..250f4cd3f 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -448,8 +448,11 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
         let common_hir_owner = fcx_typeck_results.hir_owner;
 
-        for (id, origin) in fcx_typeck_results.closure_kind_origins().iter() {
-            let hir_id = hir::HirId { owner: common_hir_owner, local_id: *id };
+        let fcx_closure_kind_origins =
+            fcx_typeck_results.closure_kind_origins().items_in_stable_order();
+
+        for (local_id, origin) in fcx_closure_kind_origins {
+            let hir_id = hir::HirId { owner: common_hir_owner, local_id };
             let place_span = origin.0;
             let place = self.resolve(origin.1.clone(), &place_span);
             self.typeck_results.closure_kind_origins_mut().insert(hir_id, (place_span, place));
@@ -458,11 +461,12 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
 
     fn visit_coercion_casts(&mut self) {
         let fcx_typeck_results = self.fcx.typeck_results.borrow();
-        let fcx_coercion_casts = fcx_typeck_results.coercion_casts();
+
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
 
+        let fcx_coercion_casts = fcx_typeck_results.coercion_casts().to_sorted_stable_ord();
         for local_id in fcx_coercion_casts {
-            self.typeck_results.set_coercion_cast(*local_id);
+            self.typeck_results.set_coercion_cast(local_id);
         }
     }
 
@@ -471,22 +475,15 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
         let common_hir_owner = fcx_typeck_results.hir_owner;
 
-        let mut errors_buffer = Vec::new();
-        for (&local_id, c_ty) in fcx_typeck_results.user_provided_types().iter() {
-            let hir_id = hir::HirId { owner: common_hir_owner, local_id };
-
-            if cfg!(debug_assertions) && c_ty.needs_infer() {
-                span_bug!(
-                    hir_id.to_span(self.fcx.tcx),
-                    "writeback: `{:?}` has inference variables",
-                    c_ty
-                );
-            };
+        if self.rustc_dump_user_substs {
+            let sorted_user_provided_types =
+                fcx_typeck_results.user_provided_types().items_in_stable_order();
 
-            self.typeck_results.user_provided_types_mut().insert(hir_id, *c_ty);
+            let mut errors_buffer = Vec::new();
+            for (local_id, c_ty) in sorted_user_provided_types {
+                let hir_id = hir::HirId { owner: common_hir_owner, local_id };
 
-            if let ty::UserType::TypeOf(_, user_substs) = c_ty.value {
-                if self.rustc_dump_user_substs {
+                if let ty::UserType::TypeOf(_, user_substs) = c_ty.value {
                     // This is a unit-testing mechanism.
                     let span = self.tcx().hir().span(hir_id);
                     // We need to buffer the errors in order to guarantee a consistent
@@ -498,31 +495,49 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
                     err.buffer(&mut errors_buffer);
                 }
             }
-        }
 
-        if !errors_buffer.is_empty() {
-            errors_buffer.sort_by_key(|diag| diag.span.primary_span());
-            for mut diag in errors_buffer {
-                self.tcx().sess.diagnostic().emit_diagnostic(&mut diag);
+            if !errors_buffer.is_empty() {
+                errors_buffer.sort_by_key(|diag| diag.span.primary_span());
+                for mut diag in errors_buffer {
+                    self.tcx().sess.diagnostic().emit_diagnostic(&mut diag);
+                }
             }
         }
+
+        self.typeck_results.user_provided_types_mut().extend(
+            fcx_typeck_results.user_provided_types().items().map(|(local_id, c_ty)| {
+                let hir_id = hir::HirId { owner: common_hir_owner, local_id };
+
+                if cfg!(debug_assertions) && c_ty.needs_infer() {
+                    span_bug!(
+                        hir_id.to_span(self.fcx.tcx),
+                        "writeback: `{:?}` has inference variables",
+                        c_ty
+                    );
+                };
+
+                (hir_id, *c_ty)
+            }),
+        );
     }
 
     fn visit_user_provided_sigs(&mut self) {
         let fcx_typeck_results = self.fcx.typeck_results.borrow();
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
 
-        for (&def_id, c_sig) in fcx_typeck_results.user_provided_sigs.iter() {
-            if cfg!(debug_assertions) && c_sig.needs_infer() {
-                span_bug!(
-                    self.fcx.tcx.def_span(def_id),
-                    "writeback: `{:?}` has inference variables",
-                    c_sig
-                );
-            };
-
-            self.typeck_results.user_provided_sigs.insert(def_id, *c_sig);
-        }
+        self.typeck_results.user_provided_sigs.extend(
+            fcx_typeck_results.user_provided_sigs.items().map(|(&def_id, c_sig)| {
+                if cfg!(debug_assertions) && c_sig.needs_infer() {
+                    span_bug!(
+                        self.fcx.tcx.def_span(def_id),
+                        "writeback: `{:?}` has inference variables",
+                        c_sig
+                    );
+                };
+
+                (def_id, *c_sig)
+            }),
+        );
     }
 
     fn visit_generator_interior_types(&mut self) {
@@ -534,8 +549,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
 
     #[instrument(skip(self), level = "debug")]
     fn visit_opaque_types(&mut self) {
-        let opaque_types =
-            self.fcx.infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types();
+        let opaque_types = self.fcx.infcx.take_opaque_types();
         for (opaque_type_key, decl) in opaque_types {
             let hidden_type = self.resolve(decl.hidden_type, &decl.hidden_type.span);
             let opaque_type_key = self.resolve(opaque_type_key, &decl.hidden_type.span);
@@ -546,7 +560,7 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
             impl<'tcx> ty::TypeVisitor<'tcx> for RecursionChecker {
                 type BreakTy = ();
                 fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
-                    if let ty::Opaque(def_id, _) = *t.kind() {
+                    if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *t.kind() {
                         if def_id == self.def_id.to_def_id() {
                             return ControlFlow::Break(());
                         }
@@ -642,7 +656,9 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
         let common_hir_owner = fcx_typeck_results.hir_owner;
 
-        for (&local_id, &fn_sig) in fcx_typeck_results.liberated_fn_sigs().iter() {
+        let fcx_liberated_fn_sigs = fcx_typeck_results.liberated_fn_sigs().items_in_stable_order();
+
+        for (local_id, &fn_sig) in fcx_liberated_fn_sigs {
             let hir_id = hir::HirId { owner: common_hir_owner, local_id };
             let fn_sig = self.resolve(fn_sig, &hir_id);
             self.typeck_results.liberated_fn_sigs_mut().insert(hir_id, fn_sig);
@@ -654,7 +670,9 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
         assert_eq!(fcx_typeck_results.hir_owner, self.typeck_results.hir_owner);
         let common_hir_owner = fcx_typeck_results.hir_owner;
 
-        for (&local_id, ftys) in fcx_typeck_results.fru_field_types().iter() {
+        let fcx_fru_field_types = fcx_typeck_results.fru_field_types().items_in_stable_order();
+
+        for (local_id, ftys) in fcx_fru_field_types {
             let hir_id = hir::HirId { owner: common_hir_owner, local_id };
             let ftys = self.resolve(ftys.clone(), &hir_id);
             self.typeck_results.fru_field_types_mut().insert(hir_id, ftys);