Merging upstream version 1.75.0+dfsg1.

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

6 files changed, 232 insertions, 85 deletions

diff --git a/compiler/rustc_hir_analysis/src/astconv/bounds.rs b/compiler/rustc_hir_analysis/src/astconv/bounds.rs
index 21611e9c5..3e700f2da 100644
--- a/compiler/rustc_hir_analysis/src/astconv/bounds.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/bounds.rs
@@ -8,6 +8,7 @@ use rustc_middle::ty::{self as ty, Ty, TypeVisitableExt};
 use rustc_span::symbol::Ident;
 use rustc_span::{ErrorGuaranteed, Span};
 use rustc_trait_selection::traits;
+use smallvec::SmallVec;
 
 use crate::astconv::{
     AstConv, ConvertedBinding, ConvertedBindingKind, OnlySelfBounds, PredicateFilter,
@@ -28,15 +29,11 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
         let tcx = self.tcx();
 
         // Try to find an unbound in bounds.
-        let mut unbound = None;
+        let mut unbounds: SmallVec<[_; 1]> = SmallVec::new();
         let mut search_bounds = |ast_bounds: &'tcx [hir::GenericBound<'tcx>]| {
             for ab in ast_bounds {
                 if let hir::GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = ab {
-                    if unbound.is_none() {
-                        unbound = Some(&ptr.trait_ref);
-                    } else {
-                        tcx.sess.emit_err(errors::MultipleRelaxedDefaultBounds { span });
-                    }
+                    unbounds.push(ptr)
                 }
             }
         };
@@ -51,33 +48,41 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
             }
         }
 
+        if unbounds.len() > 1 {
+            tcx.sess.emit_err(errors::MultipleRelaxedDefaultBounds {
+                spans: unbounds.iter().map(|ptr| ptr.span).collect(),
+            });
+        }
+
         let sized_def_id = tcx.lang_items().sized_trait();
-        match (&sized_def_id, unbound) {
-            (Some(sized_def_id), Some(tpb))
-                if tpb.path.res == Res::Def(DefKind::Trait, *sized_def_id) =>
-            {
-                // There was in fact a `?Sized` bound, return without doing anything
-                return;
-            }
-            (_, Some(_)) => {
-                // There was a `?Trait` bound, but it was not `?Sized`; warn.
-                tcx.sess.span_warn(
-                    span,
-                    "default bound relaxed for a type parameter, but \
-                        this does nothing because the given bound is not \
-                        a default; only `?Sized` is supported",
-                );
-                // Otherwise, add implicitly sized if `Sized` is available.
-            }
-            _ => {
-                // There was no `?Sized` bound; add implicitly sized if `Sized` is available.
+
+        let mut seen_sized_unbound = false;
+        for unbound in unbounds {
+            if let Some(sized_def_id) = sized_def_id {
+                if unbound.trait_ref.path.res == Res::Def(DefKind::Trait, sized_def_id) {
+                    seen_sized_unbound = true;
+                    continue;
+                }
             }
+            // There was a `?Trait` bound, but it was not `?Sized`; warn.
+            tcx.sess.span_warn(
+                unbound.span,
+                "relaxing a default bound only does something for `?Sized`; \
+                all other traits are not bound by default",
+            );
         }
+
+        // If the above loop finished there was no `?Sized` bound; add implicitly sized if `Sized` is available.
         if sized_def_id.is_none() {
             // No lang item for `Sized`, so we can't add it as a bound.
             return;
         }
-        bounds.push_sized(tcx, self_ty, span);
+        if seen_sized_unbound {
+            // There was in fact a `?Sized` bound, return without doing anything
+        } else {
+            // There was no `?Sized` bound; add implicitly sized if `Sized` is available.
+            bounds.push_sized(tcx, self_ty, span);
+        }
     }
 
     /// This helper takes a *converted* parameter type (`param_ty`)
@@ -284,6 +289,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
             self.one_bound_for_assoc_type(
                 || traits::supertraits(tcx, trait_ref),
                 trait_ref.skip_binder().print_only_trait_name(),
+                None,
                 binding.item_name,
                 path_span,
                 match binding.kind {
@@ -447,7 +453,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
 
                 debug!(?args_trait_ref_and_assoc_item);
 
-                tcx.mk_alias_ty(assoc_item.def_id, args_trait_ref_and_assoc_item)
+                ty::AliasTy::new(tcx, assoc_item.def_id, args_trait_ref_and_assoc_item)
             })
         };
 
@@ -517,8 +523,10 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
                         );
 
                         if let DefKind::AssocConst = def_kind
-                          && let Some(t) = term.ty() && (t.is_enum() || t.references_error())
-                          && tcx.features().associated_const_equality {
+                            && let Some(t) = term.ty()
+                            && (t.is_enum() || t.references_error())
+                            && tcx.features().associated_const_equality
+                        {
                             err.span_suggestion(
                                 binding.span,
                                 "if equating a const, try wrapping with braces",
diff --git a/compiler/rustc_hir_analysis/src/astconv/errors.rs b/compiler/rustc_hir_analysis/src/astconv/errors.rs
index ed4dde419..32be7e083 100644
--- a/compiler/rustc_hir_analysis/src/astconv/errors.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/errors.rs
@@ -3,17 +3,18 @@ use crate::errors::{
     AssocTypeBindingNotAllowed, ManualImplementation, MissingTypeParams,
     ParenthesizedFnTraitExpansion,
 };
+use crate::traits::error_reporting::report_object_safety_error;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{pluralize, struct_span_err, Applicability, Diagnostic, ErrorGuaranteed};
 use rustc_hir as hir;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_infer::traits::FulfillmentError;
-use rustc_middle::ty::TyCtxt;
-use rustc_middle::ty::{self, Ty};
+use rustc_middle::ty::{self, suggest_constraining_type_param, Ty, TyCtxt};
 use rustc_session::parse::feature_err;
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::{Span, Symbol, DUMMY_SP};
+use rustc_trait_selection::traits::object_safety_violations_for_assoc_item;
 
 use std::collections::BTreeSet;
 
@@ -102,6 +103,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         &self,
         all_candidates: impl Fn() -> I,
         ty_param_name: &str,
+        ty_param_def_id: Option<LocalDefId>,
         assoc_name: Ident,
         span: Span,
     ) -> ErrorGuaranteed
@@ -190,13 +192,61 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 })
                 .collect::<Vec<_>>()[..]
             {
+                let trait_name = self.tcx().def_path_str(*best_trait);
+                let an = if suggested_name != assoc_name.name { "a similarly named" } else { "an" };
                 err.span_label(
                     assoc_name.span,
                     format!(
-                        "there is a similarly named associated type `{suggested_name}` in the trait `{}`",
-                        self.tcx().def_path_str(*best_trait)
+                        "there is {an} associated type `{suggested_name}` in the \
+                         trait `{trait_name}`",
                     ),
                 );
+                let hir = self.tcx().hir();
+                if let Some(def_id) = ty_param_def_id
+                    && let parent = hir.get_parent_item(hir.local_def_id_to_hir_id(def_id))
+                    && let Some(generics) = hir.get_generics(parent.def_id)
+                {
+                    if generics.bounds_for_param(def_id)
+                        .flat_map(|pred| pred.bounds.iter())
+                        .any(|b| match b {
+                            hir::GenericBound::Trait(t, ..) => {
+                                t.trait_ref.trait_def_id().as_ref() == Some(best_trait)
+                            }
+                            _ => false,
+                        })
+                    {
+                        // The type param already has a bound for `trait_name`, we just need to
+                        // change the associated type.
+                        err.span_suggestion_verbose(
+                            assoc_name.span,
+                            format!(
+                                "change the associated type name to use `{suggested_name}` from \
+                                 `{trait_name}`",
+                            ),
+                            suggested_name.to_string(),
+                            Applicability::MaybeIncorrect,
+                        );
+                    } else if suggest_constraining_type_param(
+                            self.tcx(),
+                            generics,
+                            &mut err,
+                            &ty_param_name,
+                            &trait_name,
+                            None,
+                            None,
+                        )
+                        && suggested_name != assoc_name.name
+                    {
+                        // We suggested constraining a type parameter, but the associated type on it
+                        // was also not an exact match, so we also suggest changing it.
+                        err.span_suggestion_verbose(
+                            assoc_name.span,
+                            "and also change the associated type name",
+                            suggested_name.to_string(),
+                            Applicability::MaybeIncorrect,
+                        );
+                    }
+                }
                 return err.emit();
             }
         }
@@ -389,7 +439,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     );
 
                     let quiet_projection_ty =
-                        tcx.mk_alias_ty(projection_ty.def_id, args_with_infer_self);
+                        ty::AliasTy::new(tcx, projection_ty.def_id, args_with_infer_self);
 
                     let term = pred.skip_binder().term;
 
@@ -472,24 +522,33 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 (span, def_ids.into_iter().map(|did| tcx.associated_item(did)).collect())
             })
             .collect();
-        let mut names = vec![];
+        let mut names: FxHashMap<String, Vec<Symbol>> = Default::default();
+        let mut names_len = 0;
 
         // Account for things like `dyn Foo + 'a`, like in tests `issue-22434.rs` and
         // `issue-22560.rs`.
         let mut trait_bound_spans: Vec<Span> = vec![];
+        let mut object_safety_violations = false;
         for (span, items) in &associated_types {
             if !items.is_empty() {
                 trait_bound_spans.push(*span);
             }
             for assoc_item in items {
                 let trait_def_id = assoc_item.container_id(tcx);
-                names.push(format!(
-                    "`{}` (from trait `{}`)",
-                    assoc_item.name,
-                    tcx.def_path_str(trait_def_id),
-                ));
+                names.entry(tcx.def_path_str(trait_def_id)).or_default().push(assoc_item.name);
+                names_len += 1;
+
+                let violations =
+                    object_safety_violations_for_assoc_item(tcx, trait_def_id, *assoc_item);
+                if !violations.is_empty() {
+                    report_object_safety_error(tcx, *span, trait_def_id, &violations).emit();
+                    object_safety_violations = true;
+                }
             }
         }
+        if object_safety_violations {
+            return;
+        }
         if let ([], [bound]) = (&potential_assoc_types[..], &trait_bounds) {
             match bound.trait_ref.path.segments {
                 // FIXME: `trait_ref.path.span` can point to a full path with multiple
@@ -525,15 +584,35 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 _ => {}
             }
         }
+
+        let mut names = names
+            .into_iter()
+            .map(|(trait_, mut assocs)| {
+                assocs.sort();
+                format!(
+                    "{} in `{trait_}`",
+                    match &assocs[..] {
+                        [] => String::new(),
+                        [only] => format!("`{only}`"),
+                        [assocs @ .., last] => format!(
+                            "{} and `{last}`",
+                            assocs.iter().map(|a| format!("`{a}`")).collect::<Vec<_>>().join(", ")
+                        ),
+                    }
+                )
+            })
+            .collect::<Vec<String>>();
         names.sort();
+        let names = names.join(", ");
+
         trait_bound_spans.sort();
         let mut err = struct_span_err!(
             tcx.sess,
             trait_bound_spans,
             E0191,
             "the value of the associated type{} {} must be specified",
-            pluralize!(names.len()),
-            names.join(", "),
+            pluralize!(names_len),
+            names,
         );
         let mut suggestions = vec![];
         let mut types_count = 0;
diff --git a/compiler/rustc_hir_analysis/src/astconv/generics.rs b/compiler/rustc_hir_analysis/src/astconv/generics.rs
index e3621ef93..d29a27ece 100644
--- a/compiler/rustc_hir_analysis/src/astconv/generics.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/generics.rs
@@ -429,12 +429,22 @@ pub(crate) fn check_generic_arg_count(
         .filter(|param| matches!(param.kind, ty::GenericParamDefKind::Type { synthetic: true, .. }))
         .count();
     let named_type_param_count = param_counts.types - has_self as usize - synth_type_param_count;
+    let synth_const_param_count = gen_params
+        .params
+        .iter()
+        .filter(|param| {
+            matches!(param.kind, ty::GenericParamDefKind::Const { is_host_effect: true, .. })
+        })
+        .count();
+    let named_const_param_count = param_counts.consts - synth_const_param_count;
     let infer_lifetimes =
         (gen_pos != GenericArgPosition::Type || infer_args) && !gen_args.has_lifetime_params();
 
-    if gen_pos != GenericArgPosition::Type && let Some(b) = gen_args.bindings.first() {
-             prohibit_assoc_ty_binding(tcx, b.span, None);
-        }
+    if gen_pos != GenericArgPosition::Type
+        && let Some(b) = gen_args.bindings.first()
+    {
+        prohibit_assoc_ty_binding(tcx, b.span, None);
+    }
 
     let explicit_late_bound =
         prohibit_explicit_late_bound_lifetimes(tcx, gen_params, gen_args, gen_pos);
@@ -571,11 +581,13 @@ pub(crate) fn check_generic_arg_count(
         debug!(?expected_min);
         debug!(arg_counts.lifetimes=?gen_args.num_lifetime_params());
 
+        let provided = gen_args.num_generic_params();
+
         check_types_and_consts(
             expected_min,
-            param_counts.consts + named_type_param_count,
-            param_counts.consts + named_type_param_count + synth_type_param_count,
-            gen_args.num_generic_params(),
+            named_const_param_count + named_type_param_count,
+            named_const_param_count + named_type_param_count + synth_type_param_count,
+            provided,
             param_counts.lifetimes + has_self as usize,
             gen_args.num_lifetime_params(),
         )
diff --git a/compiler/rustc_hir_analysis/src/astconv/lint.rs b/compiler/rustc_hir_analysis/src/astconv/lint.rs
index 1bd1270be..bc57bbcca 100644
--- a/compiler/rustc_hir_analysis/src/astconv/lint.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/lint.rs
@@ -18,18 +18,26 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         if let hir::Node::Item(hir::Item {
             kind:
                 hir::ItemKind::Impl(hir::Impl {
-                    self_ty: impl_self_ty, of_trait: Some(of_trait_ref), generics, ..
+                    self_ty: impl_self_ty,
+                    of_trait: Some(of_trait_ref),
+                    generics,
+                    ..
                 }),
             ..
-        }) = tcx.hir().get_by_def_id(parent_id) && self_ty.hir_id == impl_self_ty.hir_id
+        }) = tcx.hir().get_by_def_id(parent_id)
+            && self_ty.hir_id == impl_self_ty.hir_id
         {
             if !of_trait_ref.trait_def_id().is_some_and(|def_id| def_id.is_local()) {
                 return;
             }
             let of_trait_span = of_trait_ref.path.span;
             // make sure that we are not calling unwrap to abort during the compilation
-            let Ok(impl_trait_name) = tcx.sess.source_map().span_to_snippet(self_ty.span) else { return; };
-            let Ok(of_trait_name) = tcx.sess.source_map().span_to_snippet(of_trait_span) else { return; };
+            let Ok(impl_trait_name) = tcx.sess.source_map().span_to_snippet(self_ty.span) else {
+                return;
+            };
+            let Ok(of_trait_name) = tcx.sess.source_map().span_to_snippet(of_trait_span) else {
+                return;
+            };
             // check if the trait has generics, to make a correct suggestion
             let param_name = generics.params.next_type_param_name(None);
 
@@ -39,13 +47,12 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 (generics.span, format!("<{param_name}: {impl_trait_name}>"))
             };
             diag.multipart_suggestion(
-            format!("alternatively use a blanket \
+                format!(
+                    "alternatively use a blanket \
                      implementation to implement `{of_trait_name}` for \
-                     all types that also implement `{impl_trait_name}`"),
-                vec![
-                    (self_ty.span, param_name),
-                    add_generic_sugg,
-                ],
+                     all types that also implement `{impl_trait_name}`"
+                ),
+                vec![(self_ty.span, param_name), add_generic_sugg],
                 Applicability::MaybeIncorrect,
             );
         }
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index 56b1fd369..2fcb45ef8 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -36,7 +36,7 @@ use rustc_middle::ty::{
 use rustc_session::lint::builtin::AMBIGUOUS_ASSOCIATED_ITEMS;
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::symbol::{kw, Ident, Symbol};
-use rustc_span::{sym, Span, DUMMY_SP};
+use rustc_span::{sym, BytePos, Span, DUMMY_SP};
 use rustc_target::spec::abi;
 use rustc_trait_selection::traits::wf::object_region_bounds;
 use rustc_trait_selection::traits::{self, NormalizeExt, ObligationCtxt};
@@ -567,9 +567,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         );
 
         if let ty::BoundConstness::ConstIfConst = constness
-            && generics.has_self && !tcx.has_attr(def_id, sym::const_trait)
+            && generics.has_self
+            && !tcx.has_attr(def_id, sym::const_trait)
         {
-            tcx.sess.emit_err(crate::errors::ConstBoundForNonConstTrait { span } );
+            tcx.sess.emit_err(crate::errors::ConstBoundForNonConstTrait { span });
         }
 
         (args, arg_count)
@@ -915,7 +916,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             // Type aliases defined in crates that have the
             // feature `lazy_type_alias` enabled get encoded as a type alias that normalization will
             // then actually instantiate the where bounds of.
-            let alias_ty = tcx.mk_alias_ty(did, args);
+            let alias_ty = ty::AliasTy::new(tcx, did, args);
             Ty::new_alias(tcx, ty::Weak, alias_ty)
         } else {
             tcx.at(span).type_of(did).instantiate(tcx, args)
@@ -1017,7 +1018,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     }
                     err.span_suggestions(
                         span,
-                        "use the fully-qualified path",
+                        "use fully-qualified syntax",
                         suggestions,
                         Applicability::MachineApplicable,
                     );
@@ -1061,6 +1062,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 )
             },
             param_name,
+            Some(ty_param_def_id),
             assoc_name,
             span,
             None,
@@ -1074,6 +1076,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         &self,
         all_candidates: impl Fn() -> I,
         ty_param_name: impl Display,
+        ty_param_def_id: Option<LocalDefId>,
         assoc_name: Ident,
         span: Span,
         is_equality: Option<ty::Term<'tcx>>,
@@ -1088,13 +1091,15 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             self.trait_defines_associated_item_named(r.def_id(), ty::AssocKind::Const, assoc_name)
         });
 
-        let (bound, next_cand) = match (matching_candidates.next(), const_candidates.next()) {
+        let (mut bound, mut next_cand) = match (matching_candidates.next(), const_candidates.next())
+        {
             (Some(bound), _) => (bound, matching_candidates.next()),
             (None, Some(bound)) => (bound, const_candidates.next()),
             (None, None) => {
                 let reported = self.complain_about_assoc_type_not_found(
                     all_candidates,
                     &ty_param_name.to_string(),
+                    ty_param_def_id,
                     assoc_name,
                     span,
                 );
@@ -1103,6 +1108,37 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         };
         debug!(?bound);
 
+        // look for a candidate that is not the same as our first bound, disregarding
+        // whether the bound is const.
+        while let Some(mut bound2) = next_cand {
+            debug!(?bound2);
+            let tcx = self.tcx();
+            if bound2.bound_vars() != bound.bound_vars() {
+                break;
+            }
+
+            let generics = tcx.generics_of(bound.def_id());
+            let Some(host_index) = generics.host_effect_index else { break };
+
+            // always return the bound that contains the host param.
+            if let ty::ConstKind::Param(_) = bound2.skip_binder().args.const_at(host_index).kind() {
+                (bound, bound2) = (bound2, bound);
+            }
+
+            let unconsted_args = bound
+                .skip_binder()
+                .args
+                .iter()
+                .enumerate()
+                .map(|(n, arg)| if host_index == n { tcx.consts.true_.into() } else { arg });
+
+            if unconsted_args.eq(bound2.skip_binder().args.iter()) {
+                next_cand = matching_candidates.next().or_else(|| const_candidates.next());
+            } else {
+                break;
+            }
+        }
+
         if let Some(bound2) = next_cand {
             debug!(?bound2);
 
@@ -1142,30 +1178,26 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     err.span_label(
                         bound_span,
                         format!(
-                            "ambiguous `{}` from `{}`",
-                            assoc_name,
+                            "ambiguous `{assoc_name}` from `{}`",
                             bound.print_only_trait_path(),
                         ),
                     );
                     if let Some(constraint) = &is_equality {
                         where_bounds.push(format!(
-                            "        T: {trait}::{assoc} = {constraint}",
+                            "        T: {trait}::{assoc_name} = {constraint}",
                             trait=bound.print_only_trait_path(),
-                            assoc=assoc_name,
-                            constraint=constraint,
                         ));
                     } else {
                         err.span_suggestion_verbose(
                             span.with_hi(assoc_name.span.lo()),
-                            "use fully qualified syntax to disambiguate",
-                            format!("<{} as {}>::", ty_param_name, bound.print_only_trait_path()),
+                            "use fully-qualified syntax to disambiguate",
+                            format!("<{ty_param_name} as {}>::", bound.print_only_trait_path()),
                             Applicability::MaybeIncorrect,
                         );
                     }
                 } else {
                     err.note(format!(
-                        "associated type `{}` could derive from `{}`",
-                        ty_param_name,
+                        "associated type `{ty_param_name}` could derive from `{}`",
                         bound.print_only_trait_path(),
                     ));
                 }
@@ -1173,8 +1205,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             if !where_bounds.is_empty() {
                 err.help(format!(
                     "consider introducing a new type parameter `T` and adding `where` constraints:\
-                     \n    where\n        T: {},\n{}",
-                    ty_param_name,
+                     \n    where\n        T: {ty_param_name},\n{}",
                     where_bounds.join(",\n"),
                 ));
             }
@@ -1275,8 +1306,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                                 return;
                             };
                             // Get the span of the generics args *including* the leading `::`.
-                            let args_span =
-                                assoc_segment.ident.span.shrink_to_hi().to(args.span_ext);
+                            // We do so by stretching args.span_ext to the left by 2. Earlier
+                            // it was done based on the end of assoc segment but that sometimes
+                            // led to impossible spans and caused issues like #116473
+                            let args_span = args.span_ext.with_lo(args.span_ext.lo() - BytePos(2));
                             if tcx.generics_of(adt_def.did()).count() == 0 {
                                 // FIXME(estebank): we could also verify that the arguments being
                                 // work for the `enum`, instead of just looking if it takes *any*.
@@ -1394,6 +1427,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                         )
                     },
                     kw::SelfUpper,
+                    None,
                     assoc_ident,
                     span,
                     None,
@@ -1684,7 +1718,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     .chain(args.into_iter().skip(parent_args.len())),
             );
 
-            let ty = Ty::new_alias(tcx, ty::Inherent, tcx.mk_alias_ty(assoc_item, args));
+            let ty = Ty::new_alias(tcx, ty::Inherent, ty::AliasTy::new(tcx, assoc_item, args));
 
             return Ok(Some((ty, assoc_item)));
         }
@@ -1917,9 +1951,12 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     } else {
                         Some((
                             match segment.res {
-                                Res::PrimTy(ty) => format!("{} `{}`", segment.res.descr(), ty.name()),
+                                Res::PrimTy(ty) => {
+                                    format!("{} `{}`", segment.res.descr(), ty.name())
+                                }
                                 Res::Def(_, def_id)
-                                if let Some(name) = self.tcx().opt_item_name(def_id) => {
+                                    if let Some(name) = self.tcx().opt_item_name(def_id) =>
+                                {
                                     format!("{} `{name}`", segment.res.descr())
                                 }
                                 Res::Err => "this type".to_string(),
@@ -2249,7 +2286,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                         err.note(msg);
                     }
                     for segment in path.segments {
-                        if let Some(args) = segment.args && segment.ident.name == kw::SelfUpper {
+                        if let Some(args) = segment.args
+                            && segment.ident.name == kw::SelfUpper
+                        {
                             if generics == 0 {
                                 // FIXME(estebank): we could also verify that the arguments being
                                 // work for the `enum`, instead of just looking if it takes *any*.
@@ -2631,7 +2670,9 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             .iter()
             .enumerate()
             .map(|(i, a)| {
-                if let hir::TyKind::Infer = a.kind && !self.allow_ty_infer() {
+                if let hir::TyKind::Infer = a.kind
+                    && !self.allow_ty_infer()
+                {
                     if let Some(suggested_ty) =
                         self.suggest_trait_fn_ty_for_impl_fn_infer(hir_id, Some(i))
                     {
@@ -2660,7 +2701,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     self.ast_ty_to_ty(output)
                 }
             }
-            hir::FnRetTy::DefaultReturn(..) => Ty::new_unit(tcx,),
+            hir::FnRetTy::DefaultReturn(..) => Ty::new_unit(tcx),
         };
 
         debug!(?output_ty);
diff --git a/compiler/rustc_hir_analysis/src/astconv/object_safety.rs b/compiler/rustc_hir_analysis/src/astconv/object_safety.rs
index 30c2ab8f5..00ff3f836 100644
--- a/compiler/rustc_hir_analysis/src/astconv/object_safety.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/object_safety.rs
@@ -380,7 +380,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                             span,
                             E0228,
                             "the lifetime bound for this object type cannot be deduced \
-                         from context; please supply an explicit bound"
+                             from context; please supply an explicit bound"
                         );
                         let e = if borrowed {
                             // We will have already emitted an error E0106 complaining about a