Merging upstream version 1.70.0+dfsg1.

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

5 files changed, 295 insertions, 230 deletions

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 60e55c7b0..f736f7a96 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -19,13 +19,13 @@ use rustc_hir_analysis::astconv::{
 };
 use rustc_infer::infer::canonical::{Canonical, OriginalQueryValues, QueryResponse};
 use rustc_infer::infer::error_reporting::TypeAnnotationNeeded::E0282;
-use rustc_infer::infer::InferResult;
+use rustc_infer::infer::{DefineOpaqueTypes, InferResult};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
 use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::visit::{TypeVisitable, TypeVisitableExt};
 use rustc_middle::ty::{
-    self, AdtKind, CanonicalUserType, DefIdTree, GenericParamDefKind, Ty, TyCtxt, UserType,
+    self, AdtKind, CanonicalUserType, GenericParamDefKind, Ty, TyCtxt, UserType,
 };
 use rustc_middle::ty::{GenericArgKind, SubstsRef, UserSelfTy, UserSubsts};
 use rustc_session::lint;
@@ -33,6 +33,7 @@ use rustc_span::def_id::LocalDefId;
 use rustc_span::hygiene::DesugaringKind;
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::Span;
+use rustc_target::abi::FieldIdx;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
 use rustc_trait_selection::traits::{self, NormalizeExt, ObligationCauseCode, ObligationCtxt};
 
@@ -147,7 +148,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub fn write_field_index(&self, hir_id: hir::HirId, index: usize) {
+    pub fn write_field_index(&self, hir_id: hir::HirId, index: FieldIdx) {
         self.typeck_results.borrow_mut().field_indices_mut().insert(hir_id, index);
     }
 
@@ -301,16 +302,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         span: Span,
         def_id: DefId,
         substs: SubstsRef<'tcx>,
-    ) -> (ty::InstantiatedPredicates<'tcx>, Vec<Span>) {
+    ) -> ty::InstantiatedPredicates<'tcx> {
         let bounds = self.tcx.predicates_of(def_id);
-        let spans: Vec<Span> = bounds.predicates.iter().map(|(_, span)| *span).collect();
         let result = bounds.instantiate(self.tcx, substs);
         let result = self.normalize(span, result);
-        debug!(
-            "instantiate_bounds(bounds={:?}, substs={:?}) = {:?}, {:?}",
-            bounds, substs, result, spans,
-        );
-        (result, spans)
+        debug!("instantiate_bounds(bounds={:?}, substs={:?}) = {:?}", bounds, substs, result);
+        result
     }
 
     pub(in super::super) fn normalize<T>(&self, span: Span, value: T) -> T
@@ -562,7 +559,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let span = self.tcx.hir().body(body_id).value.span;
             let ok = self
                 .at(&self.misc(span), self.param_env)
-                .eq(interior, witness)
+                .eq(DefineOpaqueTypes::No, interior, witness)
                 .expect("Failed to unify generator interior type");
             let mut obligations = ok.obligations;
 
@@ -581,11 +578,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     #[instrument(skip(self), level = "debug")]
     pub(in super::super) fn report_ambiguity_errors(&self) {
-        let mut errors = self.fulfillment_cx.borrow_mut().collect_remaining_errors();
+        let mut errors = self.fulfillment_cx.borrow_mut().collect_remaining_errors(self);
 
         if !errors.is_empty() {
             self.adjust_fulfillment_errors_for_expr_obligation(&mut errors);
-            self.err_ctxt().report_fulfillment_errors(&errors, self.inh.body_id);
+            self.err_ctxt().report_fulfillment_errors(&errors);
         }
     }
 
@@ -598,7 +595,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if !result.is_empty() {
             mutate_fulfillment_errors(&mut result);
             self.adjust_fulfillment_errors_for_expr_obligation(&mut result);
-            self.err_ctxt().report_fulfillment_errors(&result, self.inh.body_id);
+            self.err_ctxt().report_fulfillment_errors(&result);
         }
     }
 
@@ -670,7 +667,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))
                 | ty::PredicateKind::WellFormed(..)
                 | ty::PredicateKind::ObjectSafe(..)
-                | ty::PredicateKind::AliasEq(..)
+                | ty::PredicateKind::AliasRelate(..)
                 | ty::PredicateKind::ConstEvaluatable(..)
                 | ty::PredicateKind::ConstEquate(..)
                 // N.B., this predicate is created by breaking down a
@@ -902,56 +899,74 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         )
     }
 
-    /// Given a function `Node`, return its `FnDecl` if it exists, or `None` otherwise.
+    /// Given a function `Node`, return its  `HirId` and `FnDecl` if it exists. Given a closure
+    /// that is the child of a function, return that function's `HirId` and `FnDecl` instead.
+    /// This may seem confusing at first, but this is used in diagnostics for `async fn`,
+    /// for example, where most of the type checking actually happens within a nested closure,
+    /// but we often want access to the parent function's signature.
+    ///
+    /// Otherwise, return false.
     pub(in super::super) fn get_node_fn_decl(
         &self,
         node: Node<'tcx>,
-    ) -> Option<(&'tcx hir::FnDecl<'tcx>, Ident, bool)> {
+    ) -> Option<(hir::HirId, &'tcx hir::FnDecl<'tcx>, Ident, bool)> {
         match node {
-            Node::Item(&hir::Item { ident, kind: hir::ItemKind::Fn(ref sig, ..), .. }) => {
+            Node::Item(&hir::Item {
+                ident,
+                kind: hir::ItemKind::Fn(ref sig, ..),
+                owner_id,
+                ..
+            }) => {
                 // This is less than ideal, it will not suggest a return type span on any
                 // method called `main`, regardless of whether it is actually the entry point,
                 // but it will still present it as the reason for the expected type.
-                Some((&sig.decl, ident, ident.name != sym::main))
+                Some((
+                    hir::HirId::make_owner(owner_id.def_id),
+                    &sig.decl,
+                    ident,
+                    ident.name != sym::main,
+                ))
             }
             Node::TraitItem(&hir::TraitItem {
                 ident,
                 kind: hir::TraitItemKind::Fn(ref sig, ..),
+                owner_id,
                 ..
-            }) => Some((&sig.decl, ident, true)),
+            }) => Some((hir::HirId::make_owner(owner_id.def_id), &sig.decl, ident, true)),
             Node::ImplItem(&hir::ImplItem {
                 ident,
                 kind: hir::ImplItemKind::Fn(ref sig, ..),
+                owner_id,
                 ..
-            }) => Some((&sig.decl, ident, false)),
-            Node::Expr(&hir::Expr {
-                hir_id,
-                kind: hir::ExprKind::Closure(..),
-                ..
-            }) if let Some(Node::Expr(&hir::Expr {
-                hir_id,
-                kind: hir::ExprKind::Call(..),
-                ..
-            })) = self.tcx.hir().find_parent(hir_id) &&
-            let Some(Node::Item(&hir::Item {
+            }) => Some((hir::HirId::make_owner(owner_id.def_id), &sig.decl, ident, false)),
+            Node::Expr(&hir::Expr { hir_id, kind: hir::ExprKind::Closure(..), .. })
+                if let Some(Node::Item(&hir::Item {
+                    ident,
+                    kind: hir::ItemKind::Fn(ref sig, ..),
+                    owner_id,
+                    ..
+                })) = self.tcx.hir().find_parent(hir_id) => Some((
+                hir::HirId::make_owner(owner_id.def_id),
+                &sig.decl,
                 ident,
-                kind: hir::ItemKind::Fn(ref sig, ..),
-                ..
-            })) = self.tcx.hir().find_parent(hir_id) => {
-                Some((&sig.decl, ident, ident.name != sym::main))
-            },
+                ident.name != sym::main,
+            )),
             _ => None,
         }
     }
 
-    /// Given a `HirId`, return the `FnDecl` of the method it is enclosed by and whether a
+    /// Given a `HirId`, return the `HirId` of the enclosing function, its `FnDecl`, and whether a
     /// suggestion can be made, `None` otherwise.
-    pub fn get_fn_decl(&self, blk_id: hir::HirId) -> Option<(&'tcx hir::FnDecl<'tcx>, bool)> {
+    pub fn get_fn_decl(
+        &self,
+        blk_id: hir::HirId,
+    ) -> Option<(hir::HirId, &'tcx hir::FnDecl<'tcx>, bool)> {
         // Get enclosing Fn, if it is a function or a trait method, unless there's a `loop` or
         // `while` before reaching it, as block tail returns are not available in them.
         self.tcx.hir().get_return_block(blk_id).and_then(|blk_id| {
             let parent = self.tcx.hir().get(blk_id);
-            self.get_node_fn_decl(parent).map(|(fn_decl, _, is_main)| (fn_decl, is_main))
+            self.get_node_fn_decl(parent)
+                .map(|(fn_id, fn_decl, _, is_main)| (fn_id, fn_decl, is_main))
         })
     }
 
@@ -959,44 +974,75 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         err: &mut Diagnostic,
         expr: &hir::Expr<'_>,
-        expected: Ty<'tcx>,
+        expected: Option<Ty<'tcx>>,
         found: Ty<'tcx>,
     ) {
         if found != self.tcx.types.unit {
             return;
         }
-        if let ExprKind::MethodCall(path_segment, rcvr, ..) = expr.kind {
-            if self
-                .typeck_results
+
+        let ExprKind::MethodCall(path_segment, rcvr, ..) = expr.kind else {
+            return;
+        };
+
+        let rcvr_has_the_expected_type = self
+            .typeck_results
+            .borrow()
+            .expr_ty_adjusted_opt(rcvr)
+            .and_then(|ty| expected.map(|expected_ty| expected_ty.peel_refs() == ty.peel_refs()))
+            .unwrap_or(false);
+
+        let prev_call_mutates_and_returns_unit = || {
+            self.typeck_results
                 .borrow()
-                .expr_ty_adjusted_opt(rcvr)
-                .map_or(true, |ty| expected.peel_refs() != ty.peel_refs())
-            {
-                return;
-            }
-            let mut sp = MultiSpan::from_span(path_segment.ident.span);
-            sp.push_span_label(
-                path_segment.ident.span,
-                format!(
-                    "this call modifies {} in-place",
-                    match rcvr.kind {
-                        ExprKind::Path(QPath::Resolved(
-                            None,
-                            hir::Path { segments: [segment], .. },
-                        )) => format!("`{}`", segment.ident),
-                        _ => "its receiver".to_string(),
-                    }
-                ),
-            );
+                .type_dependent_def_id(expr.hir_id)
+                .map(|def_id| self.tcx.fn_sig(def_id).skip_binder().skip_binder())
+                .and_then(|sig| sig.inputs_and_output.split_last())
+                .map(|(output, inputs)| {
+                    output.is_unit()
+                        && inputs
+                            .get(0)
+                            .and_then(|self_ty| self_ty.ref_mutability())
+                            .map_or(false, rustc_ast::Mutability::is_mut)
+                })
+                .unwrap_or(false)
+        };
+
+        if !(rcvr_has_the_expected_type || prev_call_mutates_and_returns_unit()) {
+            return;
+        }
+
+        let mut sp = MultiSpan::from_span(path_segment.ident.span);
+        sp.push_span_label(
+            path_segment.ident.span,
+            format!(
+                "this call modifies {} in-place",
+                match rcvr.kind {
+                    ExprKind::Path(QPath::Resolved(
+                        None,
+                        hir::Path { segments: [segment], .. },
+                    )) => format!("`{}`", segment.ident),
+                    _ => "its receiver".to_string(),
+                }
+            ),
+        );
+
+        let modifies_rcvr_note =
+            format!("method `{}` modifies its receiver in-place", path_segment.ident);
+        if rcvr_has_the_expected_type {
             sp.push_span_label(
                 rcvr.span,
                 "you probably want to use this value after calling the method...",
             );
+            err.span_note(sp, &modifies_rcvr_note);
+            err.note(&format!("...instead of the `()` output of method `{}`", path_segment.ident));
+        } else if let ExprKind::MethodCall(..) = rcvr.kind {
             err.span_note(
                 sp,
-                &format!("method `{}` modifies its receiver in-place", path_segment.ident),
+                modifies_rcvr_note.clone() + ", it is not meant to be used in method chains.",
             );
-            err.note(&format!("...instead of the `()` output of method `{}`", path_segment.ident));
+        } else {
+            err.span_note(sp, &modifies_rcvr_note);
         }
     }
 
@@ -1319,7 +1365,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // This also occurs for an enum variant on a type alias.
             let impl_ty = self.normalize(span, tcx.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) {
+            match self.at(&self.misc(span), self.param_env).eq(
+                DefineOpaqueTypes::No,
+                impl_ty,
+                self_ty,
+            ) {
                 Ok(ok) => self.register_infer_ok_obligations(ok),
                 Err(_) => {
                     self.tcx.sess.delay_span_bug(
@@ -1367,41 +1417,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) {
         let param_env = self.param_env;
 
-        let remap = match self.tcx.def_kind(def_id) {
-            // Associated consts have `Self: ~const Trait` bounds that should be satisfiable when
-            // `Self: Trait` is satisfied because it does not matter whether the impl is `const`.
-            // Therefore we have to remap the param env here to be non-const.
-            hir::def::DefKind::AssocConst => true,
-            hir::def::DefKind::AssocFn
-                if self.tcx.def_kind(self.tcx.parent(def_id)) == hir::def::DefKind::Trait =>
-            {
-                // N.B.: All callsites to this function involve checking a path expression.
-                //
-                // When instantiating a trait method as a function item, it does not actually matter whether
-                // the trait is `const` or not, or whether `where T: ~const Tr` needs to be satisfied as
-                // `const`. If we were to introduce instantiating trait methods as `const fn`s, we would
-                // check that after this, either via a bound `where F: ~const FnOnce` or when coercing to a
-                // `const fn` pointer.
-                //
-                // FIXME(fee1-dead) FIXME(const_trait_impl): update this doc when trait methods can satisfy
-                // `~const FnOnce` or can be coerced to `const fn` pointer.
-                true
-            }
-            _ => false,
-        };
-        let (bounds, _) = self.instantiate_bounds(span, def_id, &substs);
+        let bounds = self.instantiate_bounds(span, def_id, &substs);
 
-        for mut obligation in traits::predicates_for_generics(
+        for obligation in traits::predicates_for_generics(
             |idx, predicate_span| {
                 traits::ObligationCause::new(span, self.body_id, code(idx, predicate_span))
             },
             param_env,
             bounds,
         ) {
-            if remap {
-                obligation = obligation.without_const(self.tcx);
-            }
-            self.register_predicate(obligation);
+            // N.B. We are remapping all predicates to non-const since we don't know if we just
+            // want them as function pointers or we are calling them from a const-context. The
+            // actual checking will occur in `rustc_const_eval::transform::check_consts`.
+            self.register_predicate(obligation.without_const(self.tcx));
         }
     }
 
@@ -1415,7 +1443,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else {
             let e = self.tainted_by_errors().unwrap_or_else(|| {
                 self.err_ctxt()
-                    .emit_inference_failure_err((**self).body_id, sp, ty.into(), E0282, true)
+                    .emit_inference_failure_err(self.body_id, sp, ty.into(), E0282, true)
                     .emit()
             });
             let err = self.tcx.ty_error(e);
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
index b09886fe3..f879ccbb3 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
@@ -3,10 +3,8 @@ use rustc_hir as hir;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::DefId;
 use rustc_infer::traits::ObligationCauseCode;
-use rustc_middle::ty::{
-    self, DefIdTree, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor,
-};
-use rustc_span::{self, Span};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_span::{self, symbol::kw, Span};
 use rustc_trait_selection::traits;
 
 use std::ops::ControlFlow;
@@ -27,17 +25,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let generics = self.tcx.generics_of(def_id);
         let predicate_substs = match unsubstituted_pred.kind().skip_binder() {
-            ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => pred.trait_ref.substs,
-            ty::PredicateKind::Clause(ty::Clause::Projection(pred)) => pred.projection_ty.substs,
-            _ => ty::List::empty(),
+            ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => pred.trait_ref.substs.to_vec(),
+            ty::PredicateKind::Clause(ty::Clause::Projection(pred)) => {
+                pred.projection_ty.substs.to_vec()
+            }
+            ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(arg, ty)) => {
+                vec![ty.into(), arg.into()]
+            }
+            ty::PredicateKind::ConstEvaluatable(e) => vec![e.into()],
+            _ => return false,
         };
 
-        let find_param_matching = |matches: &dyn Fn(&ty::ParamTy) -> bool| {
-            predicate_substs.types().find_map(|ty| {
-                ty.walk().find_map(|arg| {
+        let find_param_matching = |matches: &dyn Fn(ty::ParamTerm) -> bool| {
+            predicate_substs.iter().find_map(|arg| {
+                arg.walk().find_map(|arg| {
                     if let ty::GenericArgKind::Type(ty) = arg.unpack()
-                        && let ty::Param(param_ty) = ty.kind()
-                        && matches(param_ty)
+                        && let ty::Param(param_ty) = *ty.kind()
+                        && matches(ty::ParamTerm::Ty(param_ty))
+                    {
+                        Some(arg)
+                    } else if let ty::GenericArgKind::Const(ct) = arg.unpack()
+                        && let ty::ConstKind::Param(param_ct) = ct.kind()
+                        && matches(ty::ParamTerm::Const(param_ct))
                     {
                         Some(arg)
                     } else {
@@ -49,26 +58,27 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // Prefer generics that are local to the fn item, since these are likely
         // to be the cause of the unsatisfied predicate.
-        let mut param_to_point_at = find_param_matching(&|param_ty| {
-            self.tcx.parent(generics.type_param(param_ty, self.tcx).def_id) == def_id
+        let mut param_to_point_at = find_param_matching(&|param_term| {
+            self.tcx.parent(generics.param_at(param_term.index(), self.tcx).def_id) == def_id
         });
         // Fall back to generic that isn't local to the fn item. This will come
         // from a trait or impl, for example.
-        let mut fallback_param_to_point_at = find_param_matching(&|param_ty| {
-            self.tcx.parent(generics.type_param(param_ty, self.tcx).def_id) != def_id
-                && param_ty.name != rustc_span::symbol::kw::SelfUpper
+        let mut fallback_param_to_point_at = find_param_matching(&|param_term| {
+            self.tcx.parent(generics.param_at(param_term.index(), self.tcx).def_id) != def_id
+                && !matches!(param_term, ty::ParamTerm::Ty(ty) if ty.name == kw::SelfUpper)
         });
         // Finally, the `Self` parameter is possibly the reason that the predicate
         // is unsatisfied. This is less likely to be true for methods, because
         // method probe means that we already kinda check that the predicates due
         // to the `Self` type are true.
-        let mut self_param_to_point_at =
-            find_param_matching(&|param_ty| param_ty.name == rustc_span::symbol::kw::SelfUpper);
+        let mut self_param_to_point_at = find_param_matching(
+            &|param_term| matches!(param_term, ty::ParamTerm::Ty(ty) if ty.name == kw::SelfUpper),
+        );
 
         // Finally, for ambiguity-related errors, we actually want to look
         // for a parameter that is the source of the inference type left
         // over in this predicate.
-        if let traits::FulfillmentErrorCode::CodeAmbiguity = error.code {
+        if let traits::FulfillmentErrorCode::CodeAmbiguity { .. } = error.code {
             fallback_param_to_point_at = None;
             self_param_to_point_at = None;
             param_to_point_at =
@@ -227,15 +237,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .own_substs(ty::InternalSubsts::identity_for_item(self.tcx, def_id));
         let Some((index, _)) = own_substs
             .iter()
-            .filter(|arg| matches!(arg.unpack(), ty::GenericArgKind::Type(_)))
             .enumerate()
             .find(|(_, arg)| **arg == param_to_point_at) else { return false };
         let Some(arg) = segment
             .args()
             .args
-            .iter()
-            .filter(|arg| matches!(arg, hir::GenericArg::Type(_)))
-            .nth(index) else { return false; };
+            .get(index) else { return false; };
         error.obligation.cause.span = arg
             .span()
             .find_ancestor_in_same_ctxt(error.obligation.cause.span)
@@ -302,7 +309,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .iter()
             .filter(|field| {
                 let field_ty = field.ty(self.tcx, identity_substs);
-                Self::find_param_in_ty(field_ty.into(), param_to_point_at)
+                find_param_in_ty(field_ty.into(), param_to_point_at)
             })
             .collect();
 
@@ -348,7 +355,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .inputs()
             .iter()
             .enumerate()
-            .filter(|(_, ty)| Self::find_param_in_ty((**ty).into(), param_to_point_at))
+            .filter(|(_, ty)| find_param_in_ty((**ty).into(), param_to_point_at))
             .collect();
         // If there's one field that references the given generic, great!
         if let [(idx, _)] = args_referencing_param.as_slice()
@@ -459,7 +466,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// obligation. Hence we refine the `expr` "outwards-in" and bail at the first kind of expression/impl we don't recognize.
     ///
     /// This function returns a `Result<&Expr, &Expr>` - either way, it returns the `Expr` whose span should be
-    /// reported as an error. If it is `Ok`, then it means it refined successfull. If it is `Err`, then it may be
+    /// reported as an error. If it is `Ok`, then it means it refined successful. If it is `Err`, then it may be
     /// only a partial success - but it cannot be refined even further.
     fn blame_specific_expr_if_possible_for_derived_predicate_obligation(
         &self,
@@ -527,7 +534,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// - in_ty: `(Option<Vec<T>, bool)`
     /// we would drill until we arrive at `vec![1, 2, 3]`.
     ///
-    /// If successful, we return `Ok(refined_expr)`. If unsuccesful, we return `Err(partially_refined_expr`),
+    /// If successful, we return `Ok(refined_expr)`. If unsuccessful, we return `Err(partially_refined_expr`),
     /// which will go as far as possible. For example, given `(foo(), false)` instead, we would drill to
     /// `foo()` and then return `Err("foo()")`.
     ///
@@ -571,8 +578,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Find out which of `in_ty_elements` refer to `param`.
             // FIXME: It may be better to take the first if there are multiple,
             // just so that the error points to a smaller expression.
-            let Some((drill_expr, drill_ty)) = Self::is_iterator_singleton(expr_elements.iter().zip( in_ty_elements.iter()).filter(|(_expr_elem, in_ty_elem)| {
-                Self::find_param_in_ty((*in_ty_elem).into(), param)
+            let Some((drill_expr, drill_ty)) = is_iterator_singleton(expr_elements.iter().zip( in_ty_elements.iter()).filter(|(_expr_elem, in_ty_elem)| {
+                find_param_in_ty((*in_ty_elem).into(), param)
             })) else {
                 // The param is not mentioned, or it is mentioned in multiple indexes.
                 return Err(expr);
@@ -620,10 +627,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // We need to know which of the generic parameters mentions our target param.
             // We expect that at least one of them does, since it is expected to be mentioned.
             let Some((drill_generic_index, generic_argument_type)) =
-                Self::is_iterator_singleton(
+                is_iterator_singleton(
                     in_ty_adt_generic_args.iter().enumerate().filter(
                         |(_index, in_ty_generic)| {
-                            Self::find_param_in_ty(*in_ty_generic, param)
+                            find_param_in_ty(*in_ty_generic, param)
                         },
                     ),
                 ) else {
@@ -743,10 +750,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // We need to know which of the generic parameters mentions our target param.
             // We expect that at least one of them does, since it is expected to be mentioned.
             let Some((drill_generic_index, generic_argument_type)) =
-                Self::is_iterator_singleton(
+                is_iterator_singleton(
                     in_ty_adt_generic_args.iter().enumerate().filter(
                         |(_index, in_ty_generic)| {
-                            Self::find_param_in_ty(*in_ty_generic, param)
+                            find_param_in_ty(*in_ty_generic, param)
                         },
                     ),
                 ) else {
@@ -785,14 +792,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             //     outer contextual information.
 
             // (1) Find the (unique) field index which mentions the type in our constraint:
-            let Some((field_index, field_type)) = Self::is_iterator_singleton(
+            let Some((field_index, field_type)) = is_iterator_singleton(
                 in_ty_adt
                     .variant_with_id(variant_def_id)
                     .fields
                     .iter()
                     .map(|field| field.ty(self.tcx, *in_ty_adt_generic_args))
                     .enumerate()
-                    .filter(|(_index, field_type)| Self::find_param_in_ty((*field_type).into(), param))
+                    .filter(|(_index, field_type)| find_param_in_ty((*field_type).into(), param))
             ) else {
                 return Err(expr);
             };
@@ -825,20 +832,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         Err(expr)
     }
+}
 
-    // FIXME: This can be made into a private, non-impl function later.
-    /// Traverses the given ty (either a `ty::Ty` or a `ty::GenericArg`) and searches for references
-    /// to the given `param_to_point_at`. Returns `true` if it finds any use of the param.
-    pub fn find_param_in_ty(
-        ty: ty::GenericArg<'tcx>,
-        param_to_point_at: ty::GenericArg<'tcx>,
-    ) -> bool {
-        let mut walk = ty.walk();
-        while let Some(arg) = walk.next() {
-            if arg == param_to_point_at {
-                return true;
-            }
-            if let ty::GenericArgKind::Type(ty) = arg.unpack()
+/// Traverses the given ty (either a `ty::Ty` or a `ty::GenericArg`) and searches for references
+/// to the given `param_to_point_at`. Returns `true` if it finds any use of the param.
+fn find_param_in_ty<'tcx>(
+    ty: ty::GenericArg<'tcx>,
+    param_to_point_at: ty::GenericArg<'tcx>,
+) -> bool {
+    let mut walk = ty.walk();
+    while let Some(arg) = walk.next() {
+        if arg == param_to_point_at {
+            return true;
+        }
+        if let ty::GenericArgKind::Type(ty) = arg.unpack()
                 && let ty::Alias(ty::Projection, ..) = ty.kind()
             {
                 // This logic may seem a bit strange, but typically when
@@ -849,16 +856,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // in some UI tests.
                 walk.skip_current_subtree();
             }
-        }
-        false
     }
+    false
+}
 
-    // FIXME: This can be made into a private, non-impl function later.
-    /// Returns `Some(iterator.next())` if it has exactly one item, and `None` otherwise.
-    pub fn is_iterator_singleton<T>(mut iterator: impl Iterator<Item = T>) -> Option<T> {
-        match (iterator.next(), iterator.next()) {
-            (_, Some(_)) => None,
-            (first, _) => first,
-        }
+/// Returns `Some(iterator.next())` if it has exactly one item, and `None` otherwise.
+fn is_iterator_singleton<T>(mut iterator: impl Iterator<Item = T>) -> Option<T> {
+    match (iterator.next(), iterator.next()) {
+        (_, Some(_)) => None,
+        (first, _) => first,
     }
 }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index a46bdeb41..ea1b52daa 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -24,14 +24,14 @@ use rustc_hir_analysis::structured_errors::StructuredDiagnostic;
 use rustc_index::vec::IndexVec;
 use rustc_infer::infer::error_reporting::{FailureCode, ObligationCauseExt};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
-use rustc_infer::infer::InferOk;
 use rustc_infer::infer::TypeTrace;
+use rustc_infer::infer::{DefineOpaqueTypes, InferOk};
 use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::visit::TypeVisitableExt;
-use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty};
+use rustc_middle::ty::{self, IsSuggestable, Ty};
 use rustc_session::Session;
 use rustc_span::symbol::{kw, Ident};
-use rustc_span::{self, sym, Span};
+use rustc_span::{self, sym, BytePos, Span};
 use rustc_trait_selection::traits::{self, ObligationCauseCode, SelectionContext};
 
 use std::iter;
@@ -301,9 +301,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
             // 3. Check if the formal type is a supertype of the checked one
             //    and register any such obligations for future type checks
-            let supertype_error = self
-                .at(&self.misc(provided_arg.span), self.param_env)
-                .sup(formal_input_ty, coerced_ty);
+            let supertype_error = self.at(&self.misc(provided_arg.span), self.param_env).sup(
+                DefineOpaqueTypes::No,
+                formal_input_ty,
+                coerced_ty,
+            );
             let subtyping_error = match supertype_error {
                 Ok(InferOk { obligations, value: () }) => {
                     self.register_predicates(obligations);
@@ -470,7 +472,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         err_code: &str,
         fn_def_id: Option<DefId>,
         call_span: Span,
-        call_expr: &hir::Expr<'tcx>,
+        call_expr: &'tcx hir::Expr<'tcx>,
     ) {
         // Next, let's construct the error
         let (error_span, full_call_span, call_name, is_method) = match &call_expr.kind {
@@ -585,7 +587,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
             // Using probe here, since we don't want this subtyping to affect inference.
             let subtyping_error = self.probe(|_| {
-                self.at(&self.misc(arg_span), self.param_env).sup(formal_input_ty, coerced_ty).err()
+                self.at(&self.misc(arg_span), self.param_env)
+                    .sup(DefineOpaqueTypes::No, formal_input_ty, coerced_ty)
+                    .err()
             });
 
             // Same as above: if either the coerce type or the checked type is an error type,
@@ -764,7 +768,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let (provided_ty, provided_span) = provided_arg_tys[*provided_idx];
             let trace =
                 mk_trace(provided_span, formal_and_expected_inputs[*expected_idx], provided_ty);
-            if !matches!(trace.cause.as_failure_code(*e), FailureCode::Error0308(_)) {
+            if !matches!(trace.cause.as_failure_code(*e), FailureCode::Error0308) {
                 self.err_ctxt().report_and_explain_type_error(trace, *e).emit();
                 return true;
             }
@@ -803,24 +807,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 full_call_span,
                 format!("arguments to this {} are incorrect", call_name),
             );
-            if let (Some(callee_ty), hir::ExprKind::MethodCall(_, rcvr, _, _)) =
-                (callee_ty, &call_expr.kind)
+
+            if let hir::ExprKind::MethodCall(_, rcvr, _, _) = call_expr.kind
+                && provided_idx.as_usize() == expected_idx.as_usize()
             {
-                // Type that would have accepted this argument if it hadn't been inferred earlier.
-                // FIXME: We leave an inference variable for now, but it'd be nice to get a more
-                // specific type to increase the accuracy of the diagnostic.
-                let expected = self.infcx.next_ty_var(TypeVariableOrigin {
-                    kind: TypeVariableOriginKind::MiscVariable,
-                    span: full_call_span,
-                });
-                self.point_at_expr_source_of_inferred_type(
+                self.note_source_of_type_mismatch_constraint(
                     &mut err,
                     rcvr,
-                    expected,
-                    callee_ty,
-                    provided_arg_span,
+                    crate::demand::TypeMismatchSource::Arg {
+                        call_expr,
+                        incompatible_arg: provided_idx.as_usize(),
+                    },
                 );
             }
+
             // Call out where the function is defined
             self.label_fn_like(
                 &mut err,
@@ -890,8 +890,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         };
 
         let mut errors = errors.into_iter().peekable();
+        let mut only_extras_so_far = errors
+            .peek()
+            .map_or(false, |first| matches!(first, Error::Extra(arg_idx) if arg_idx.index() == 0));
         let mut suggestions = vec![];
         while let Some(error) = errors.next() {
+            only_extras_so_far &= matches!(error, Error::Extra(_));
+
             match error {
                 Error::Invalid(provided_idx, expected_idx, compatibility) => {
                     let (formal_ty, expected_ty) = formal_and_expected_inputs[expected_idx];
@@ -937,10 +942,34 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         if arg_idx.index() > 0
                         && let Some((_, prev)) = provided_arg_tys
                             .get(ProvidedIdx::from_usize(arg_idx.index() - 1)
-                    ) {
-                        // Include previous comma
-                        span = prev.shrink_to_hi().to(span);
-                    }
+                        ) {
+                            // Include previous comma
+                            span = prev.shrink_to_hi().to(span);
+                        }
+
+                        // Is last argument for deletion in a row starting from the 0-th argument?
+                        // Then delete the next comma, so we are not left with `f(, ...)`
+                        //
+                        //     fn f() {}
+                        //   - f(0, 1,)
+                        //   + f()
+                        if only_extras_so_far
+                            && errors
+                                .peek()
+                                .map_or(true, |next_error| !matches!(next_error, Error::Extra(_)))
+                        {
+                            let next = provided_arg_tys
+                                .get(arg_idx + 1)
+                                .map(|&(_, sp)| sp)
+                                .unwrap_or_else(|| {
+                                    // Subtract one to move before `)`
+                                    call_expr.span.with_lo(call_expr.span.hi() - BytePos(1))
+                                });
+
+                            // Include next comma
+                            span = span.until(next);
+                        }
+
                         suggestions.push((span, String::new()));
 
                         suggestion_text = match suggestion_text {
@@ -1158,11 +1187,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // index position where it *should have been*, which is *after* the previous one.
             if let Some(provided_idx) = provided_idx {
                 prev = provided_idx.index() as i64;
+                continue;
             }
             let idx = ProvidedIdx::from_usize((prev + 1) as usize);
-            if let None = provided_idx
-                && let Some((_, arg_span)) = provided_arg_tys.get(idx)
-            {
+            if let Some((_, arg_span)) = provided_arg_tys.get(idx) {
+                prev += 1;
                 // There is a type that was *not* found anywhere, so it isn't a move, but a
                 // replacement and we look at what type it should have been. This will allow us
                 // To suggest a multipart suggestion when encountering `foo(1, "")` where the def
@@ -1380,7 +1409,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.demand_eqtype(init.span, local_ty, init_ty);
             init_ty
         } else {
-            self.check_expr_coercable_to_type(init, local_ty, None)
+            self.check_expr_coercible_to_type(init, local_ty, None)
         }
     }
 
@@ -1665,7 +1694,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Given a function block's `HirId`, returns its `FnDecl` if it exists, or `None` otherwise.
     fn get_parent_fn_decl(&self, blk_id: hir::HirId) -> Option<(&'tcx hir::FnDecl<'tcx>, Ident)> {
         let parent = self.tcx.hir().get_by_def_id(self.tcx.hir().get_parent_item(blk_id).def_id);
-        self.get_node_fn_decl(parent).map(|(fn_decl, ident, _)| (fn_decl, ident))
+        self.get_node_fn_decl(parent).map(|(_, fn_decl, ident, _)| (fn_decl, ident))
     }
 
     /// If `expr` is a `match` expression that has only one non-`!` arm, use that arm's tail
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
index 1dea3e6f9..c6fd0b610 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs
@@ -211,13 +211,13 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
     fn get_type_parameter_bounds(
         &self,
         _: Span,
-        def_id: DefId,
+        def_id: LocalDefId,
         _: Ident,
     ) -> ty::GenericPredicates<'tcx> {
         let tcx = self.tcx;
-        let item_def_id = tcx.hir().ty_param_owner(def_id.expect_local());
+        let item_def_id = tcx.hir().ty_param_owner(def_id);
         let generics = tcx.generics_of(item_def_id);
-        let index = generics.param_def_id_to_index[&def_id];
+        let index = generics.param_def_id_to_index[&def_id.to_def_id()];
         ty::GenericPredicates {
             parent: None,
             predicates: tcx.arena.alloc_from_iter(
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index c49621b7c..5fda4e191 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -16,7 +16,7 @@ use rustc_infer::traits::{self, StatementAsExpression};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::{
-    self, suggest_constraining_type_params, Binder, DefIdTree, IsSuggestable, ToPredicate, Ty,
+    self, suggest_constraining_type_params, Binder, IsSuggestable, ToPredicate, Ty,
     TypeVisitableExt,
 };
 use rustc_session::errors::ExprParenthesesNeeded;
@@ -64,8 +64,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let expr = expr.peel_drop_temps();
         self.suggest_missing_semicolon(err, expr, expected, false);
         let mut pointing_at_return_type = false;
-        if let Some((fn_decl, can_suggest)) = self.get_fn_decl(blk_id) {
-            let fn_id = self.tcx.hir().get_return_block(blk_id).unwrap();
+        if let Some((fn_id, fn_decl, can_suggest)) = self.get_fn_decl(blk_id) {
             pointing_at_return_type = self.suggest_missing_return_type(
                 err,
                 &fn_decl,
@@ -166,8 +165,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         ty: Ty<'tcx>,
     ) -> Option<(DefIdOrName, Ty<'tcx>, Vec<Ty<'tcx>>)> {
-        let body_hir_id = self.tcx.hir().local_def_id_to_hir_id(self.body_id);
-        self.err_ctxt().extract_callable_info(body_hir_id, self.param_env, ty)
+        self.err_ctxt().extract_callable_info(self.body_id, self.param_env, ty)
     }
 
     pub fn suggest_two_fn_call(
@@ -669,6 +667,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// This routine checks if the return type is left as default, the method is not part of an
     /// `impl` block and that it isn't the `main` method. If so, it suggests setting the return
     /// type.
+    #[instrument(level = "trace", skip(self, err))]
     pub(in super::super) fn suggest_missing_return_type(
         &self,
         err: &mut Diagnostic,
@@ -705,28 +704,24 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     return true
                 }
             }
-            hir::FnRetTy::Return(ty) => {
-                let span = ty.span;
-
-                if let hir::TyKind::OpaqueDef(item_id, ..) = ty.kind
-                && let hir::Node::Item(hir::Item {
-                    kind: hir::ItemKind::OpaqueTy(op_ty),
-                    ..
-                }) = self.tcx.hir().get(item_id.hir_id())
-                && let hir::OpaqueTy {
-                    bounds: [bound], ..
-                } = op_ty
-                && let hir::GenericBound::LangItemTrait(
-                    hir::LangItem::Future, _, _, generic_args) = bound
-                && let hir::GenericArgs { bindings: [ty_binding], .. } = generic_args
-                && let hir::TypeBinding { kind, .. } = ty_binding
-                && let hir::TypeBindingKind::Equality { term } = kind
-                && let hir::Term::Ty(term_ty) = term {
+            hir::FnRetTy::Return(hir_ty) => {
+                let span = hir_ty.span;
+
+                if let hir::TyKind::OpaqueDef(item_id, ..) = hir_ty.kind
+                    && let hir::Node::Item(hir::Item {
+                        kind: hir::ItemKind::OpaqueTy(op_ty),
+                        ..
+                    }) = self.tcx.hir().get(item_id.hir_id())
+                    && let [hir::GenericBound::LangItemTrait(
+                        hir::LangItem::Future, _, _, generic_args)] = op_ty.bounds
+                    && let hir::GenericArgs { bindings: [ty_binding], .. } = generic_args
+                    && let hir::TypeBindingKind::Equality { term: hir::Term::Ty(term) } = ty_binding.kind
+                {
                     // Check if async function's return type was omitted.
                     // Don't emit suggestions if the found type is `impl Future<...>`.
-                    debug!("suggest_missing_return_type: found = {:?}", found);
+                    debug!(?found);
                     if found.is_suggestable(self.tcx, false) {
-                        if term_ty.span.is_empty() {
+                        if term.span.is_empty() {
                             err.subdiagnostic(AddReturnTypeSuggestion::Add { span, found: found.to_string() });
                             return true;
                         } else {
@@ -737,11 +732,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                 // 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 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);
+                debug!("return type {:?}", hir_ty);
+                let ty = self.astconv().ast_ty_to_ty(hir_ty);
+                debug!("return type {:?}", ty);
+                debug!("expected type {:?}", expected);
+                let bound_vars = self.tcx.late_bound_vars(hir_ty.hir_id.owner.into());
                 let ty = Binder::bind_with_vars(ty, bound_vars);
                 let ty = self.normalize(span, ty);
                 let ty = self.tcx.erase_late_bound_regions(ty);
@@ -988,13 +983,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 )
                 .must_apply_modulo_regions()
           {
-              diag.span_suggestion_verbose(
-                  expr.span.shrink_to_hi(),
-                  "consider using clone here",
-                  ".clone()",
-                  Applicability::MachineApplicable,
-              );
-              return true;
+            let suggestion = match self.maybe_get_struct_pattern_shorthand_field(expr) {
+                Some(ident) => format!(": {}.clone()", ident),
+                None => ".clone()".to_string()
+            };
+
+            diag.span_suggestion_verbose(
+                expr.span.shrink_to_hi(),
+                "consider using clone here",
+                suggestion,
+                Applicability::MachineApplicable,
+            );
+            return true;
           }
         false
     }
@@ -1015,11 +1015,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut suggest_copied_or_cloned = || {
             let expr_inner_ty = substs.type_at(0);
             let expected_inner_ty = expected_substs.type_at(0);
-            if let ty::Ref(_, ty, hir::Mutability::Not) = expr_inner_ty.kind()
-                && self.can_eq(self.param_env, *ty, expected_inner_ty)
+            if let &ty::Ref(_, ty, hir::Mutability::Not) = expr_inner_ty.kind()
+                && self.can_eq(self.param_env, ty, expected_inner_ty)
             {
                 let def_path = self.tcx.def_path_str(adt_def.did());
-                if self.type_is_copy_modulo_regions(self.param_env, *ty, expr.span) {
+                if self.type_is_copy_modulo_regions(self.param_env, ty) {
                     diag.span_suggestion_verbose(
                         expr.span.shrink_to_hi(),
                         format!(
@@ -1033,9 +1033,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     && rustc_trait_selection::traits::type_known_to_meet_bound_modulo_regions(
                         self,
                         self.param_env,
-                        *ty,
+                        ty,
                         clone_did,
-                        expr.span
                     )
                 {
                     diag.span_suggestion_verbose(
@@ -1156,13 +1155,17 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return false;
         }
 
-        diag.span_suggestion(
+        let suggestion = match self.maybe_get_struct_pattern_shorthand_field(expr) {
+            Some(ident) => format!(": {}.is_some()", ident),
+            None => ".is_some()".to_string(),
+        };
+
+        diag.span_suggestion_verbose(
             expr.span.shrink_to_hi(),
             "use `Option::is_some` to test if the `Option` has a value",
-            ".is_some()",
+            suggestion,
             Applicability::MachineApplicable,
         );
-
         true
     }