Fix clippy::needless_borrow in the compiler

`x clippy compiler -Aclippy::all -Wclippy::needless_borrow --fix`.

Then I had to remove a few unnecessary parens and muts that were exposed
now.

compiler/rustc_abi/src/layout.rs

@@ -111,8 +111,8 @@ pub trait LayoutCalculator {
                             alt_tail_space,
                             layout.fields.count(),
                             prefer_alt_layout,
-                            format_field_niches(&layout, &fields, &dl),
-                            format_field_niches(&alt_layout, &fields, &dl),
+                            format_field_niches(layout, fields, dl),
+                            format_field_niches(&alt_layout, fields, dl),
                         );
 
                         if prefer_alt_layout {
@@ -1025,7 +1025,7 @@ fn univariant<
     // At the bottom of this function, we invert `inverse_memory_index` to
     // produce `memory_index` (see `invert_mapping`).
     let mut sized = true;
-    let mut offsets = IndexVec::from_elem(Size::ZERO, &fields);
+    let mut offsets = IndexVec::from_elem(Size::ZERO, fields);
     let mut offset = Size::ZERO;
     let mut largest_niche = None;
     let mut largest_niche_available = 0;

compiler/rustc_ast/src/attr/mod.rs

@@ -391,7 +391,7 @@ impl MetaItemKind {
                 MetaItemKind::name_value_from_tokens(&mut inner_tokens.trees())
             }
             Some(TokenTree::Token(token, _)) => {
-                MetaItemLit::from_token(&token).map(MetaItemKind::NameValue)
+                MetaItemLit::from_token(token).map(MetaItemKind::NameValue)
             }
             _ => None,
         }

compiler/rustc_ast_lowering/src/expr.rs

@@ -959,7 +959,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 e
             });
             let coroutine_option =
-                this.coroutine_movability_for_fn(&decl, fn_decl_span, coroutine_kind, movability);
+                this.coroutine_movability_for_fn(decl, fn_decl_span, coroutine_kind, movability);
             this.current_item = prev;
             (body_id, coroutine_option)
         });
@@ -1057,7 +1057,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             let body_id = this.lower_fn_body(&outer_decl, |this| {
                 let async_ret_ty = if let FnRetTy::Ty(ty) = &decl.output {
                     let itctx = ImplTraitContext::Disallowed(ImplTraitPosition::AsyncBlock);
-                    Some(hir::FnRetTy::Return(this.lower_ty(&ty, &itctx)))
+                    Some(hir::FnRetTy::Return(this.lower_ty(ty, &itctx)))
                 } else {
                     None
                 };
@@ -1156,7 +1156,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             .alloc_from_iter(std::iter::once(destructure_let).chain(assignments.into_iter()));
 
         // Wrap everything in a block.
-        hir::ExprKind::Block(&self.block_all(whole_span, stmts, None), None)
+        hir::ExprKind::Block(self.block_all(whole_span, stmts, None), None)
     }
 
     /// If the given expression is a path to a tuple struct, returns that path.
@@ -1413,7 +1413,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let fields = self.arena.alloc_from_iter(
             e1.iter().map(|e| (sym::start, e)).chain(e2.iter().map(|e| (sym::end, e))).map(
                 |(s, e)| {
-                    let expr = self.lower_expr(&e);
+                    let expr = self.lower_expr(e);
                     let ident = Ident::new(s, self.lower_span(e.span));
                     self.expr_field(ident, expr, e.span)
                 },

compiler/rustc_ast_lowering/src/format.rs

@@ -338,8 +338,8 @@ fn make_format_spec<'hir>(
         | ((debug_hex == Some(FormatDebugHex::Lower)) as u32) << 4
         | ((debug_hex == Some(FormatDebugHex::Upper)) as u32) << 5;
     let flags = ctx.expr_u32(sp, flags);
-    let precision = make_count(ctx, sp, &precision, argmap);
-    let width = make_count(ctx, sp, &width, argmap);
+    let precision = make_count(ctx, sp, precision, argmap);
+    let width = make_count(ctx, sp, width, argmap);
     let format_placeholder_new = ctx.arena.alloc(ctx.expr_lang_item_type_relative(
         sp,
         hir::LangItem::FormatPlaceholder,

compiler/rustc_ast_lowering/src/index.rs

@@ -47,7 +47,7 @@ pub(super) fn index_hir<'hir>(
 
     match item {
         OwnerNode::Crate(citem) => {
-            collector.visit_mod(&citem, citem.spans.inner_span, hir::CRATE_HIR_ID)
+            collector.visit_mod(citem, citem.spans.inner_span, hir::CRATE_HIR_ID)
         }
         OwnerNode::Item(item) => collector.visit_item(item),
         OwnerNode::TraitItem(item) => collector.visit_trait_item(item),

compiler/rustc_ast_lowering/src/item.rs

@@ -276,19 +276,14 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     // only cares about the input argument patterns in the function
                     // declaration (decl), not the return types.
                     let asyncness = header.asyncness;
-                    let body_id = this.lower_maybe_async_body(
-                        span,
-                        hir_id,
-                        &decl,
-                        asyncness,
-                        body.as_deref(),
-                    );
+                    let body_id =
+                        this.lower_maybe_async_body(span, hir_id, decl, asyncness, body.as_deref());
 
                     let itctx = ImplTraitContext::Universal;
                     let (generics, decl) =
                         this.lower_generics(generics, header.constness, id, &itctx, |this| {
                             let ret_id = asyncness.opt_return_id();
-                            this.lower_fn_decl(&decl, id, *fn_sig_span, FnDeclKind::Fn, ret_id)
+                            this.lower_fn_decl(decl, id, *fn_sig_span, FnDeclKind::Fn, ret_id)
                         });
                     let sig = hir::FnSig {
                         decl,
@@ -744,7 +739,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let (generics, kind, has_default) = match &i.kind {
             AssocItemKind::Const(box ConstItem { generics, ty, expr, .. }) => {
                 let (generics, kind) = self.lower_generics(
-                    &generics,
+                    generics,
                     Const::No,
                     i.id,
                     &ImplTraitContext::Disallowed(ImplTraitPosition::Generic),
@@ -775,7 +770,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
             AssocItemKind::Fn(box Fn { sig, generics, body: Some(body), .. }) => {
                 let asyncness = sig.header.asyncness;
                 let body_id =
-                    self.lower_maybe_async_body(i.span, hir_id, &sig.decl, asyncness, Some(&body));
+                    self.lower_maybe_async_body(i.span, hir_id, &sig.decl, asyncness, Some(body));
                 let (generics, sig) = self.lower_method_sig(
                     generics,
                     sig,
@@ -857,7 +852,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
         let (generics, kind) = match &i.kind {
             AssocItemKind::Const(box ConstItem { generics, ty, expr, .. }) => self.lower_generics(
-                &generics,
+                generics,
                 Const::No,
                 i.id,
                 &ImplTraitContext::Disallowed(ImplTraitPosition::Generic),

compiler/rustc_ast_lowering/src/lib.rs

@@ -1157,7 +1157,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         itctx: &ImplTraitContext,
     ) -> hir::GenericArg<'hir> {
         match arg {
-            ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(&lt)),
+            ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(lt)),
             ast::GenericArg::Type(ty) => {
                 match &ty.kind {
                     TyKind::Infer if self.tcx.features().generic_arg_infer => {
@@ -1221,10 +1221,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     }
                     _ => {}
                 }
-                GenericArg::Type(self.lower_ty(&ty, itctx))
+                GenericArg::Type(self.lower_ty(ty, itctx))
             }
             ast::GenericArg::Const(ct) => GenericArg::Const(ConstArg {
-                value: self.lower_anon_const(&ct),
+                value: self.lower_anon_const(ct),
                 span: self.lower_span(ct.value.span),
                 is_desugared_from_effects: false,
             }),
@@ -1267,7 +1267,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 let lifetime_bound = this.elided_dyn_bound(t.span);
                 (bounds, lifetime_bound)
             });
-            let kind = hir::TyKind::TraitObject(bounds, &lifetime_bound, TraitObjectSyntax::None);
+            let kind = hir::TyKind::TraitObject(bounds, lifetime_bound, TraitObjectSyntax::None);
             return hir::Ty { kind, span: self.lower_span(t.span), hir_id: self.next_id() };
         }
 
@@ -1551,7 +1551,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     // in fn return position, like the `fn test<'a>() -> impl Debug + 'a`
                     // example, we only need to duplicate lifetimes that appear in the
                     // bounds, since those are the only ones that are captured by the opaque.
-                    lifetime_collector::lifetimes_in_bounds(&self.resolver, bounds)
+                    lifetime_collector::lifetimes_in_bounds(self.resolver, bounds)
                 }
             }
             hir::OpaqueTyOrigin::AsyncFn(..) => {
@@ -2067,10 +2067,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 (hir::ParamName::Plain(self.lower_ident(param.ident)), kind)
             }
             GenericParamKind::Const { ty, kw_span: _, default } => {
-                let ty = self.lower_ty(
-                    &ty,
-                    &ImplTraitContext::Disallowed(ImplTraitPosition::GenericDefault),
-                );
+                let ty = self
+                    .lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::GenericDefault));
                 let default = default.as_ref().map(|def| self.lower_anon_const(def));
                 (
                     hir::ParamName::Plain(self.lower_ident(param.ident)),

compiler/rustc_ast_lowering/src/path.rs

@@ -372,10 +372,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             // ```
             FnRetTy::Ty(ty) if matches!(itctx, ImplTraitContext::ReturnPositionOpaqueTy { .. }) => {
                 if self.tcx.features().impl_trait_in_fn_trait_return {
-                    self.lower_ty(&ty, itctx)
+                    self.lower_ty(ty, itctx)
                 } else {
                     self.lower_ty(
-                        &ty,
+                        ty,
                         &ImplTraitContext::FeatureGated(
                             ImplTraitPosition::FnTraitReturn,
                             sym::impl_trait_in_fn_trait_return,
@@ -384,7 +384,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 }
             }
             FnRetTy::Ty(ty) => {
-                self.lower_ty(&ty, &ImplTraitContext::Disallowed(ImplTraitPosition::FnTraitReturn))
+                self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::FnTraitReturn))
             }
             FnRetTy::Default(_) => self.arena.alloc(self.ty_tup(*span, &[])),
         };

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -221,7 +221,7 @@ impl<'a> AstValidator<'a> {
     }
 
     fn err_handler(&self) -> &rustc_errors::Handler {
-        &self.session.diagnostic()
+        self.session.diagnostic()
     }
 
     fn check_lifetime(&self, ident: Ident) {
@@ -622,7 +622,7 @@ impl<'a> AstValidator<'a> {
             data: data.span,
             constraint_spans: errors::EmptyLabelManySpans(constraint_spans),
             arg_spans2: errors::EmptyLabelManySpans(arg_spans),
-            suggestion: self.correct_generic_order_suggestion(&data),
+            suggestion: self.correct_generic_order_suggestion(data),
             constraint_len,
             args_len,
         });
@@ -738,7 +738,7 @@ fn validate_generic_param_order(
 
             if !bounds.is_empty() {
                 ordered_params += ": ";
-                ordered_params += &pprust::bounds_to_string(&bounds);
+                ordered_params += &pprust::bounds_to_string(bounds);
             }
 
             match kind {

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -88,7 +88,7 @@ impl<'a> PostExpansionVisitor<'a> {
             }
         }
 
-        match abi::is_enabled(&self.features, span, symbol_unescaped.as_str()) {
+        match abi::is_enabled(self.features, span, symbol_unescaped.as_str()) {
             Ok(()) => (),
             Err(abi::AbiDisabled::Unstable { feature, explain }) => {
                 feature_err_issue(
@@ -182,7 +182,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             ..
         }) = attr_info
         {
-            gate_alt!(self, has_feature(&self.features), *name, attr.span, *descr);
+            gate_alt!(self, has_feature(self.features), *name, attr.span, *descr);
         }
         // Check unstable flavors of the `#[doc]` attribute.
         if attr.has_name(sym::doc) {
@@ -300,7 +300,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             }
 
             ast::ItemKind::TyAlias(box ast::TyAlias { ty: Some(ty), .. }) => {
-                self.check_impl_trait(&ty, false)
+                self.check_impl_trait(ty, false)
             }
 
             _ => {}

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1078,11 +1078,11 @@ impl<'a> State<'a> {
             }
             ast::TyKind::AnonStruct(fields) => {
                 self.head("struct");
-                self.print_record_struct_body(&fields, ty.span);
+                self.print_record_struct_body(fields, ty.span);
             }
             ast::TyKind::AnonUnion(fields) => {
                 self.head("union");
-                self.print_record_struct_body(&fields, ty.span);
+                self.print_record_struct_body(fields, ty.span);
             }
             ast::TyKind::Paren(typ) => {
                 self.popen();

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -368,7 +368,7 @@ impl<'a> State<'a> {
                 self.nbsp();
                 if !bounds.is_empty() {
                     self.word_nbsp("=");
-                    self.print_type_bounds(&bounds);
+                    self.print_type_bounds(bounds);
                 }
                 self.print_where_clause(&generics.where_clause);
                 self.word(";");

compiler/rustc_attr/src/builtin.rs

@@ -552,7 +552,7 @@ pub fn cfg_matches(
 fn try_gate_cfg(name: Symbol, span: Span, sess: &ParseSess, features: Option<&Features>) {
     let gate = find_gated_cfg(|sym| sym == name);
     if let (Some(feats), Some(gated_cfg)) = (features, gate) {
-        gate_cfg(&gated_cfg, span, sess, feats);
+        gate_cfg(gated_cfg, span, sess, feats);
     }
 }
 

compiler/rustc_borrowck/src/borrow_set.rs

@@ -107,7 +107,7 @@ impl LocalsStateAtExit {
             LocalsStateAtExit::AllAreInvalidated
         } else {
             let mut has_storage_dead = HasStorageDead(BitSet::new_empty(body.local_decls.len()));
-            has_storage_dead.visit_body(&body);
+            has_storage_dead.visit_body(body);
             let mut has_storage_dead_or_moved = has_storage_dead.0;
             for move_out in &move_data.moves {
                 if let Some(index) = move_data.base_local(move_out.path) {
@@ -128,7 +128,7 @@ impl<'tcx> BorrowSet<'tcx> {
     ) -> Self {
         let mut visitor = GatherBorrows {
             tcx,
-            body: &body,
+            body: body,
             location_map: Default::default(),
             activation_map: Default::default(),
             local_map: Default::default(),
@@ -140,7 +140,7 @@ impl<'tcx> BorrowSet<'tcx> {
             ),
         };
 
-        for (block, block_data) in traversal::preorder(&body) {
+        for (block, block_data) in traversal::preorder(body) {
             visitor.visit_basic_block_data(block, block_data);
         }
 

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -490,7 +490,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let mut spans = vec![];
         for init_idx in inits {
             let init = &self.move_data.inits[*init_idx];
-            let span = init.span(&self.body);
+            let span = init.span(self.body);
             if !span.is_dummy() {
                 spans.push(span);
             }
@@ -518,7 +518,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let body = map.body(body_id);
 
         let mut visitor = ConditionVisitor { spans: &spans, name: &name, errors: vec![] };
-        visitor.visit_body(&body);
+        visitor.visit_body(body);
 
         let mut show_assign_sugg = false;
         let isnt_initialized = if let InitializationRequiringAction::PartialAssignment
@@ -614,7 +614,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
 
             let mut visitor = LetVisitor { decl_span, sugg_span: None };
-            visitor.visit_body(&body);
+            visitor.visit_body(body);
             if let Some(span) = visitor.sugg_span {
                 self.suggest_assign_value(&mut err, moved_place, span);
             }
@@ -779,7 +779,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             return;
         };
         // Try to find predicates on *generic params* that would allow copying `ty`
-        let ocx = ObligationCtxt::new(&self.infcx);
+        let ocx = ObligationCtxt::new(self.infcx);
         let copy_did = tcx.require_lang_item(LangItem::Copy, Some(span));
         let cause = ObligationCause::misc(span, self.mir_def_id());
 
@@ -856,7 +856,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         self.explain_why_borrow_contains_point(location, borrow, None)
             .add_explanation_to_diagnostic(
                 self.infcx.tcx,
-                &self.body,
+                self.body,
                 &self.local_names,
                 &mut err,
                 "",
@@ -903,7 +903,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         self.explain_why_borrow_contains_point(location, borrow, None)
             .add_explanation_to_diagnostic(
                 self.infcx.tcx,
-                &self.body,
+                self.body,
                 &self.local_names,
                 &mut err,
                 "",
@@ -1174,7 +1174,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
         explanation.add_explanation_to_diagnostic(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             &self.local_names,
             &mut err,
             first_borrow_desc,
@@ -1932,7 +1932,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let place_desc = self.describe_place(borrow.borrowed_place.as_ref());
 
         let kind_place = kind.filter(|_| place_desc.is_some()).map(|k| (k, place_span.0));
-        let explanation = self.explain_why_borrow_contains_point(location, &borrow, kind_place);
+        let explanation = self.explain_why_borrow_contains_point(location, borrow, kind_place);
 
         debug!(?place_desc, ?explanation);
 
@@ -2001,14 +2001,14 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             (Some(name), explanation) => self.report_local_value_does_not_live_long_enough(
                 location,
                 &name,
-                &borrow,
+                borrow,
                 drop_span,
                 borrow_spans,
                 explanation,
             ),
             (None, explanation) => self.report_temporary_value_does_not_live_long_enough(
                 location,
-                &borrow,
+                borrow,
                 drop_span,
                 borrow_spans,
                 proper_span,
@@ -2098,7 +2098,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             } else {
                 explanation.add_explanation_to_diagnostic(
                     self.infcx.tcx,
-                    &self.body,
+                    self.body,
                     &self.local_names,
                     &mut err,
                     "",
@@ -2119,7 +2119,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
             explanation.add_explanation_to_diagnostic(
                 self.infcx.tcx,
-                &self.body,
+                self.body,
                 &self.local_names,
                 &mut err,
                 "",
@@ -2180,7 +2180,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
         explanation.add_explanation_to_diagnostic(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             &self.local_names,
             &mut err,
             "",
@@ -2365,7 +2365,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         }
         explanation.add_explanation_to_diagnostic(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             &self.local_names,
             &mut err,
             "",
@@ -2842,7 +2842,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
         self.explain_why_borrow_contains_point(location, loan, None).add_explanation_to_diagnostic(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             &self.local_names,
             &mut err,
             "",
@@ -3020,7 +3020,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
         }
         let mut visitor = FakeReadCauseFinder { place, cause: None };
-        visitor.visit_body(&self.body);
+        visitor.visit_body(self.body);
         match visitor.cause {
             Some(FakeReadCause::ForMatchGuard) => Some("match guard"),
             Some(FakeReadCause::ForIndex) => Some("indexing expression"),

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -422,7 +422,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         kind_place: Option<(WriteKind, Place<'tcx>)>,
     ) -> BorrowExplanation<'tcx> {
         let regioncx = &self.regioncx;
-        let body: &Body<'_> = &self.body;
+        let body: &Body<'_> = self.body;
         let tcx = self.infcx.tcx;
 
         let borrow_region_vid = borrow.region;

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -354,7 +354,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 ty::Adt(def, _) => {
                     let variant = if let Some(idx) = variant_index {
                         assert!(def.is_enum());
-                        &def.variant(idx)
+                        def.variant(idx)
                     } else {
                         def.non_enum_variant()
                     };
@@ -851,7 +851,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         {
             let Some((method_did, method_args)) = rustc_middle::util::find_self_call(
                 self.infcx.tcx,
-                &self.body,
+                self.body,
                 target_temp,
                 location.block,
             ) else {
@@ -1048,7 +1048,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         let ty = moved_place.ty(self.body, tcx).ty;
                         let suggest = match tcx.get_diagnostic_item(sym::IntoIterator) {
                             Some(def_id) => type_known_to_meet_bound_modulo_regions(
-                                &self.infcx,
+                                self.infcx,
                                 self.param_env,
                                 Ty::new_imm_ref(tcx, tcx.lifetimes.re_erased, ty),
                                 def_id,

compiler/rustc_borrowck/src/diagnostics/move_errors.rs

@@ -321,7 +321,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         let deref_base = match deref_target_place.projection.as_ref() {
             [proj_base @ .., ProjectionElem::Deref] => {
-                PlaceRef { local: deref_target_place.local, projection: &proj_base }
+                PlaceRef { local: deref_target_place.local, projection: proj_base }
             }
             _ => bug!("deref_target_place is not a deref projection"),
         };
@@ -583,7 +583,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 err.subdiagnostic(crate::session_diagnostics::TypeNoCopy::Label {
                     is_partial_move: false,
                     ty: bind_to.ty,
-                    place: &place_desc,
+                    place: place_desc,
                     span: binding_span,
                 });
             }

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -650,14 +650,14 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         let fr_name_and_span = self.regioncx.get_var_name_and_span_for_region(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             &self.local_names,
             &self.upvars,
             errci.fr,
         );
         let outlived_fr_name_and_span = self.regioncx.get_var_name_and_span_for_region(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             &self.local_names,
             &self.upvars,
             errci.outlived_fr,
@@ -971,7 +971,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         for found_did in found_dids {
             let mut traits = vec![];
             let mut hir_v = HirTraitObjectVisitor(&mut traits, *found_did);
-            hir_v.visit_ty(&self_ty);
+            hir_v.visit_ty(self_ty);
             debug!("trait spans found: {:?}", traits);
             for span in &traits {
                 let mut multi_span: MultiSpan = vec![*span].into();

compiler/rustc_borrowck/src/diagnostics/region_name.rs

@@ -387,7 +387,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
         let arg_ty = self.regioncx.universal_regions().unnormalized_input_tys
             [implicit_inputs + argument_index];
         let (_, span) = self.regioncx.get_argument_name_and_span_for_region(
-            &self.body,
+            self.body,
             &self.local_names,
             argument_index,
         );

compiler/rustc_borrowck/src/invalidation.rs

@@ -34,7 +34,7 @@ pub(super) fn generate_invalidates<'tcx>(
             borrow_set,
             tcx,
             location_table,
-            body: &body,
+            body: body,
             dominators,
         };
         ig.visit_body(body);
@@ -383,7 +383,7 @@ impl<'cx, 'tcx> InvalidationGenerator<'cx, 'tcx> {
 
                     (Read(_), BorrowKind::Mut { .. }) => {
                         // Reading from mere reservations of mutable-borrows is OK.
-                        if !is_active(&this.dominators, borrow, location) {
+                        if !is_active(this.dominators, borrow, location) {
                             // If the borrow isn't active yet, reads don't invalidate it
                             assert!(allow_two_phase_borrow(borrow.kind));
                             return Control::Continue;

compiler/rustc_borrowck/src/lib.rs

@@ -219,18 +219,18 @@ fn do_mir_borrowck<'tcx>(
     let location_table_owned = LocationTable::new(body);
     let location_table = &location_table_owned;
 
-    let move_data = MoveData::gather_moves(&body, tcx, param_env, |_| true);
+    let move_data = MoveData::gather_moves(body, tcx, param_env, |_| true);
     let promoted_move_data = promoted
         .iter_enumerated()
-        .map(|(idx, body)| (idx, MoveData::gather_moves(&body, tcx, param_env, |_| true)));
+        .map(|(idx, body)| (idx, MoveData::gather_moves(body, tcx, param_env, |_| true)));
 
     let mdpe = MoveDataParamEnv { move_data, param_env };
 
-    let mut flow_inits = MaybeInitializedPlaces::new(tcx, &body, &mdpe)
-        .into_engine(tcx, &body)
+    let mut flow_inits = MaybeInitializedPlaces::new(tcx, body, &mdpe)
+        .into_engine(tcx, body)
         .pass_name("borrowck")
         .iterate_to_fixpoint()
-        .into_results_cursor(&body);
+        .into_results_cursor(body);
 
     let locals_are_invalidated_at_exit = tcx.hir().body_owner_kind(def).is_fn_or_closure();
     let borrow_set =
@@ -260,13 +260,13 @@ fn do_mir_borrowck<'tcx>(
 
     // Dump MIR results into a file, if that is enabled. This let us
     // write unit-tests, as well as helping with debugging.
-    nll::dump_mir_results(&infcx, &body, &regioncx, &opt_closure_req);
+    nll::dump_mir_results(&infcx, body, &regioncx, &opt_closure_req);
 
     // We also have a `#[rustc_regions]` annotation that causes us to dump
     // information.
     nll::dump_annotation(
         &infcx,
-        &body,
+        body,
         &regioncx,
         &opt_closure_req,
         &opaque_type_values,
@@ -1538,7 +1538,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
         if places_conflict::borrow_conflicts_with_place(
             self.infcx.tcx,
-            &self.body,
+            self.body,
             place,
             borrow.kind,
             root_place,
@@ -2193,7 +2193,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 // If this is a mutate access to an immutable local variable with no projections
                 // report the error as an illegal reassignment
                 let init = &self.move_data.inits[init_index];
-                let assigned_span = init.span(&self.body);
+                let assigned_span = init.span(self.body);
                 self.report_illegal_reassignment(location, (place, span), assigned_span, place);
             } else {
                 self.report_mutability_error(place, span, the_place_err, error_access, location)

compiler/rustc_borrowck/src/nll.rs

@@ -179,7 +179,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
 
     let universal_regions = Rc::new(universal_regions);
 
-    let elements = &Rc::new(RegionValueElements::new(&body));
+    let elements = &Rc::new(RegionValueElements::new(body));
 
     // Run the MIR type-checker.
     let MirTypeckResults {
@@ -206,7 +206,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
     if let Some(all_facts) = &mut all_facts {
         let _prof_timer = infcx.tcx.prof.generic_activity("polonius_fact_generation");
         all_facts.universal_region.extend(universal_regions.universal_regions());
-        populate_polonius_move_facts(all_facts, move_data, location_table, &body);
+        populate_polonius_move_facts(all_facts, move_data, location_table, body);
 
         // Emit universal regions facts, and their relations, for Polonius.
         //
@@ -263,7 +263,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
         &mut liveness_constraints,
         &mut all_facts,
         location_table,
-        &body,
+        body,
         borrow_set,
     );
 
@@ -302,7 +302,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
             let algorithm = Algorithm::from_str(&algorithm).unwrap();
             debug!("compute_regions: using polonius algorithm {:?}", algorithm);
             let _prof_timer = infcx.tcx.prof.generic_activity("polonius_analysis");
-            Some(Rc::new(Output::compute(&all_facts, algorithm, false)))
+            Some(Rc::new(Output::compute(all_facts, algorithm, false)))
         } else {
             None
         }
@@ -310,7 +310,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
 
     // Solve the region constraints.
     let (closure_region_requirements, nll_errors) =
-        regioncx.solve(infcx, param_env, &body, polonius_output.clone());
+        regioncx.solve(infcx, param_env, body, polonius_output.clone());
 
     if !nll_errors.is_empty() {
         // Suppress unhelpful extra errors in `infer_opaque_types`.
@@ -320,7 +320,7 @@ pub(crate) fn compute_regions<'cx, 'tcx>(
         ));
     }
 
-    let remapped_opaque_tys = regioncx.infer_opaque_types(&infcx, opaque_type_values);
+    let remapped_opaque_tys = regioncx.infer_opaque_types(infcx, opaque_type_values);
 
     NllOutput {
         regioncx,

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -303,7 +303,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
             Locations::All(span),
             span,
             ConstraintCategory::Internal,
-            &mut self.constraints,
+            self.constraints,
         )
         .convert_all(data);
     }

compiler/rustc_borrowck/src/type_check/liveness/local_use_map.rs

@@ -80,7 +80,7 @@ impl LocalUseMap {
         live_locals.iter().for_each(|&local| locals_with_use_data[local] = true);
 
         LocalUseMapBuild { local_use_map: &mut local_use_map, elements, locals_with_use_data }
-            .visit_body(&body);
+            .visit_body(body);
 
         local_use_map
     }

compiler/rustc_borrowck/src/type_check/liveness/mod.rs

@@ -42,11 +42,11 @@ pub(super) fn generate<'mir, 'tcx>(
 
     let free_regions = regions_that_outlive_free_regions(
         typeck.infcx.num_region_vars(),
-        &typeck.borrowck_context.universal_regions,
+        typeck.borrowck_context.universal_regions,
         &typeck.borrowck_context.constraints.outlives_constraints,
     );
     let (relevant_live_locals, boring_locals) =
-        compute_relevant_live_locals(typeck.tcx(), &free_regions, &body);
+        compute_relevant_live_locals(typeck.tcx(), &free_regions, body);
     let facts_enabled = use_polonius || AllFacts::enabled(typeck.tcx());
 
     let polonius_drop_used = facts_enabled.then(|| {

compiler/rustc_borrowck/src/type_check/liveness/polonius.rs

@@ -100,7 +100,7 @@ pub(super) fn populate_access_facts<'a, 'tcx>(
             location_table,
             move_data,
         };
-        extractor.visit_body(&body);
+        extractor.visit_body(body);
 
         facts.var_dropped_at.extend(
             dropped_at.iter().map(|&(local, location)| (local, location_table.mid_index(location))),

compiler/rustc_borrowck/src/type_check/liveness/trace.rs

@@ -64,7 +64,7 @@ pub(super) fn trace<'mir, 'tcx>(
         let num_region_vars = typeck.infcx.num_region_vars();
         let graph = constraint_set.graph(num_region_vars);
         let region_graph =
-            graph.region_graph(&constraint_set, borrowck_context.universal_regions.fr_static);
+            graph.region_graph(constraint_set, borrowck_context.universal_regions.fr_static);
 
         // Traverse each issuing region's constraints, and record the loan as flowing into the
         // outlived region.
@@ -489,7 +489,7 @@ impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> {
         }
 
         let move_paths = &self.flow_inits.analysis().move_data().move_paths;
-        move_paths[mpi].find_descendant(&move_paths, |mpi| state.contains(mpi)).is_some()
+        move_paths[mpi].find_descendant(move_paths, |mpi| state.contains(mpi)).is_some()
     }
 
     /// Returns `true` if the local variable (or some part of it) is initialized in
@@ -522,7 +522,7 @@ impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> {
 
         Self::make_all_regions_live(
             self.elements,
-            &mut self.typeck,
+            self.typeck,
             value,
             live_at,
             &self.inflowing_loans,
@@ -579,13 +579,13 @@ impl<'tcx> LivenessContext<'_, '_, '_, 'tcx> {
         for &kind in &drop_data.dropck_result.kinds {
             Self::make_all_regions_live(
                 self.elements,
-                &mut self.typeck,
+                self.typeck,
                 kind,
                 live_at,
                 &self.inflowing_loans,
             );
 
-            polonius::add_drop_of_var_derefs_origin(&mut self.typeck, dropped_local, &kind);
+            polonius::add_drop_of_var_derefs_origin(self.typeck, dropped_local, &kind);
         }
     }
 

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -191,11 +191,11 @@ pub(crate) fn type_check<'mir, 'tcx>(
     checker.check_user_type_annotations();
 
     let mut verifier = TypeVerifier::new(&mut checker, promoted);
-    verifier.visit_body(&body);
+    verifier.visit_body(body);
 
     checker.typeck_mir(body);
-    checker.equate_inputs_and_outputs(&body, universal_regions, &normalized_inputs_and_output);
-    checker.check_signature_annotation(&body);
+    checker.equate_inputs_and_outputs(body, universal_regions, &normalized_inputs_and_output);
+    checker.check_signature_annotation(body);
 
     liveness::generate(
         &mut checker,
@@ -389,7 +389,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
                     self.cx.ascribe_user_type(
                         constant.const_.ty(),
                         UserType::TypeOf(uv.def, UserArgs { args: uv.args, user_self_ty: None }),
-                        locations.span(&self.cx.body),
+                        locations.span(self.cx.body),
                     );
                 }
             } else if let Some(static_def_id) = constant.check_static_ptr(tcx) {
@@ -553,7 +553,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
         let all_facts = &mut None;
         let mut constraints = Default::default();
         let mut liveness_constraints =
-            LivenessValues::new(Rc::new(RegionValueElements::new(&promoted_body)));
+            LivenessValues::new(Rc::new(RegionValueElements::new(promoted_body)));
         // Don't try to add borrow_region facts for the promoted MIR
 
         let mut swap_constraints = |this: &mut Self| {
@@ -570,7 +570,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
 
         swap_constraints(self);
 
-        self.visit_body(&promoted_body);
+        self.visit_body(promoted_body);
 
         self.cx.typeck_mir(promoted_body);
 
@@ -1127,7 +1127,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             locations,
             locations.span(self.body),
             category,
-            &mut self.borrowck_context.constraints,
+            self.borrowck_context.constraints,
         )
         .convert_all(data);
     }
@@ -1854,7 +1854,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 for op in ops {
                     self.check_operand(op, location);
                 }
-                self.check_aggregate_rvalue(&body, rvalue, ak, ops, location)
+                self.check_aggregate_rvalue(body, rvalue, ak, ops, location)
             }
 
             Rvalue::Repeat(operand, len) => {
@@ -2300,7 +2300,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             }
 
             Rvalue::Ref(region, _borrow_kind, borrowed_place) => {
-                self.add_reborrow_constraint(&body, location, *region, borrowed_place);
+                self.add_reborrow_constraint(body, location, *region, borrowed_place);
             }
 
             Rvalue::BinaryOp(
@@ -2512,7 +2512,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         let tcx = self.infcx.tcx;
         let field = path_utils::is_upvar_field_projection(
             tcx,
-            &self.borrowck_context.upvars,
+            self.borrowck_context.upvars,
             borrowed_place.as_ref(),
             body,
         );
@@ -2668,13 +2668,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 location.to_locations(),
                 DUMMY_SP,                   // irrelevant; will be overridden.
                 ConstraintCategory::Boring, // same as above.
-                &mut self.borrowck_context.constraints,
+                self.borrowck_context.constraints,
             )
-            .apply_closure_requirements(
-                &closure_requirements,
-                def_id.to_def_id(),
-                args,
-            );
+            .apply_closure_requirements(closure_requirements, def_id.to_def_id(), args);
         }
 
         // Now equate closure args to regions inherited from `typeck_root_def_id`. Fixes #98589.
@@ -2714,7 +2710,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         debug!(?body.span);
 
         for (local, local_decl) in body.local_decls.iter_enumerated() {
-            self.check_local(&body, local, local_decl);
+            self.check_local(body, local, local_decl);
         }
 
         for (block, block_data) in body.basic_blocks.iter_enumerated() {
@@ -2727,8 +2723,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 location.statement_index += 1;
             }
 
-            self.check_terminator(&body, block_data.terminator(), location);
-            self.check_iscleanup(&body, block_data);
+            self.check_terminator(body, block_data.terminator(), location);
+            self.check_iscleanup(body, block_data);
         }
     }
 }

compiler/rustc_borrowck/src/used_muts.rs

@@ -35,7 +35,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 never_initialized_mut_locals: &mut never_initialized_mut_locals,
                 mbcx: self,
             };
-            visitor.visit_body(&visitor.mbcx.body);
+            visitor.visit_body(visitor.mbcx.body);
         }
 
         // Take the union of the existed `used_mut` set with those variables we've found were

compiler/rustc_builtin_macros/src/cfg_accessible.rs

@@ -47,7 +47,7 @@ impl MultiItemModifier for Expander {
         let template = AttributeTemplate { list: Some("path"), ..Default::default() };
         validate_attr::check_builtin_meta_item(
             &ecx.sess.parse_sess,
-            &meta_item,
+            meta_item,
             ast::AttrStyle::Outer,
             sym::cfg_accessible,
             template,

compiler/rustc_builtin_macros/src/cfg_eval.rs

@@ -25,7 +25,7 @@ pub(crate) fn expand(
     annotatable: Annotatable,
 ) -> Vec<Annotatable> {
     check_builtin_macro_attribute(ecx, meta_item, sym::cfg_eval);
-    warn_on_duplicate_attribute(&ecx, &annotatable, sym::cfg_eval);
+    warn_on_duplicate_attribute(ecx, &annotatable, sym::cfg_eval);
     vec![cfg_eval(ecx.sess, ecx.ecfg.features, annotatable, ecx.current_expansion.lint_node_id)]
 }
 
@@ -95,19 +95,19 @@ impl CfgFinder {
     fn has_cfg_or_cfg_attr(annotatable: &Annotatable) -> bool {
         let mut finder = CfgFinder { has_cfg_or_cfg_attr: false };
         match annotatable {
-            Annotatable::Item(item) => finder.visit_item(&item),
-            Annotatable::TraitItem(item) => finder.visit_assoc_item(&item, visit::AssocCtxt::Trait),
-            Annotatable::ImplItem(item) => finder.visit_assoc_item(&item, visit::AssocCtxt::Impl),
-            Annotatable::ForeignItem(item) => finder.visit_foreign_item(&item),
-            Annotatable::Stmt(stmt) => finder.visit_stmt(&stmt),
-            Annotatable::Expr(expr) => finder.visit_expr(&expr),
-            Annotatable::Arm(arm) => finder.visit_arm(&arm),
-            Annotatable::ExprField(field) => finder.visit_expr_field(&field),
-            Annotatable::PatField(field) => finder.visit_pat_field(&field),
-            Annotatable::GenericParam(param) => finder.visit_generic_param(&param),
-            Annotatable::Param(param) => finder.visit_param(&param),
-            Annotatable::FieldDef(field) => finder.visit_field_def(&field),
-            Annotatable::Variant(variant) => finder.visit_variant(&variant),
+            Annotatable::Item(item) => finder.visit_item(item),
+            Annotatable::TraitItem(item) => finder.visit_assoc_item(item, visit::AssocCtxt::Trait),
+            Annotatable::ImplItem(item) => finder.visit_assoc_item(item, visit::AssocCtxt::Impl),
+            Annotatable::ForeignItem(item) => finder.visit_foreign_item(item),
+            Annotatable::Stmt(stmt) => finder.visit_stmt(stmt),
+            Annotatable::Expr(expr) => finder.visit_expr(expr),
+            Annotatable::Arm(arm) => finder.visit_arm(arm),
+            Annotatable::ExprField(field) => finder.visit_expr_field(field),
+            Annotatable::PatField(field) => finder.visit_pat_field(field),
+            Annotatable::GenericParam(param) => finder.visit_generic_param(param),
+            Annotatable::Param(param) => finder.visit_param(param),
+            Annotatable::FieldDef(field) => finder.visit_field_def(field),
+            Annotatable::Variant(variant) => finder.visit_variant(variant),
             Annotatable::Crate(krate) => finder.visit_crate(krate),
         };
         finder.has_cfg_or_cfg_attr

compiler/rustc_builtin_macros/src/cmdline_attrs.rs

@@ -11,7 +11,7 @@ pub fn inject(krate: &mut ast::Crate, parse_sess: &ParseSess, attrs: &[String])
     for raw_attr in attrs {
         let mut parser = rustc_parse::new_parser_from_source_str(
             parse_sess,
-            FileName::cli_crate_attr_source_code(&raw_attr),
+            FileName::cli_crate_attr_source_code(raw_attr),
             raw_attr.clone(),
         );
 

compiler/rustc_builtin_macros/src/concat_bytes.rs

@@ -159,7 +159,7 @@ pub fn expand_concat_bytes(
                     accumulator.push(val);
                 }
                 Ok(ast::LitKind::ByteStr(ref bytes, _)) => {
-                    accumulator.extend_from_slice(&bytes);
+                    accumulator.extend_from_slice(bytes);
                 }
                 _ => {
                     if !has_errors {

compiler/rustc_builtin_macros/src/derive.rs

@@ -35,7 +35,7 @@ impl MultiItemModifier for Expander {
                     AttributeTemplate { list: Some("Trait1, Trait2, ..."), ..Default::default() };
                 validate_attr::check_builtin_meta_item(
                     &sess.parse_sess,
-                    &meta_item,
+                    meta_item,
                     ast::AttrStyle::Outer,
                     sym::derive,
                     template,
@@ -48,14 +48,14 @@ impl MultiItemModifier for Expander {
                                 NestedMetaItem::MetaItem(meta) => Some(meta),
                                 NestedMetaItem::Lit(lit) => {
                                     // Reject `#[derive("Debug")]`.
-                                    report_unexpected_meta_item_lit(sess, &lit);
+                                    report_unexpected_meta_item_lit(sess, lit);
                                     None
                                 }
                             })
                             .map(|meta| {
                                 // Reject `#[derive(Debug = "value", Debug(abc))]`, but recover the
                                 // paths.
-                                report_path_args(sess, &meta);
+                                report_path_args(sess, meta);
                                 meta.path.clone()
                             })
                             .map(|path| (path, dummy_annotatable(), None, self.0))

compiler/rustc_builtin_macros/src/deriving/generic/mod.rs

@@ -467,7 +467,7 @@ impl<'a> TraitDef<'a> {
         match item {
             Annotatable::Item(item) => {
                 let is_packed = item.attrs.iter().any(|attr| {
-                    for r in attr::find_repr_attrs(&cx.sess, attr) {
+                    for r in attr::find_repr_attrs(cx.sess, attr) {
                         if let attr::ReprPacked(_) = r {
                             return true;
                         }
@@ -478,7 +478,7 @@ impl<'a> TraitDef<'a> {
                 let newitem = match &item.kind {
                     ast::ItemKind::Struct(struct_def, generics) => self.expand_struct_def(
                         cx,
-                        &struct_def,
+                        struct_def,
                         item.ident,
                         generics,
                         from_scratch,
@@ -496,7 +496,7 @@ impl<'a> TraitDef<'a> {
                         if self.supports_unions {
                             self.expand_struct_def(
                                 cx,
-                                &struct_def,
+                                struct_def,
                                 item.ident,
                                 generics,
                                 from_scratch,

compiler/rustc_builtin_macros/src/deriving/generic/ty.rs

@@ -182,7 +182,7 @@ impl Bounds {
         let params = self
             .bounds
             .iter()
-            .map(|&(name, ref bounds)| mk_ty_param(cx, span, name, &bounds, self_ty, self_generics))
+            .map(|&(name, ref bounds)| mk_ty_param(cx, span, name, bounds, self_ty, self_generics))
             .collect();
 
         Generics {

compiler/rustc_builtin_macros/src/format.rs

@@ -547,7 +547,7 @@ fn make_format_args(
                 span: arg_name.span.into(),
                 msg: format!("named argument `{}` is not used by name", arg_name.name).into(),
                 node_id: rustc_ast::CRATE_NODE_ID,
-                lint_id: LintId::of(&NAMED_ARGUMENTS_USED_POSITIONALLY),
+                lint_id: LintId::of(NAMED_ARGUMENTS_USED_POSITIONALLY),
                 diagnostic: BuiltinLintDiagnostics::NamedArgumentUsedPositionally {
                     position_sp_to_replace,
                     position_sp_for_msg,
@@ -632,8 +632,7 @@ fn report_missing_placeholders(
         .collect::<Vec<_>>();
 
     if !placeholders.is_empty() {
-        if let Some(mut new_diag) =
-            report_redundant_format_arguments(ecx, &args, used, placeholders)
+        if let Some(mut new_diag) = report_redundant_format_arguments(ecx, args, used, placeholders)
         {
             diag.cancel();
             new_diag.emit();

compiler/rustc_builtin_macros/src/source_util.rs

@@ -133,7 +133,7 @@ pub fn expand_include<'cx>(
             let r = base::parse_expr(&mut self.p)?;
             if self.p.token != token::Eof {
                 self.p.sess.buffer_lint(
-                    &INCOMPLETE_INCLUDE,
+                    INCOMPLETE_INCLUDE,
                     self.p.token.span,
                     self.node_id,
                     "include macro expected single expression in source",
@@ -189,7 +189,7 @@ pub fn expand_include_str(
     match cx.source_map().load_binary_file(&file) {
         Ok(bytes) => match std::str::from_utf8(&bytes) {
             Ok(src) => {
-                let interned_src = Symbol::intern(&src);
+                let interned_src = Symbol::intern(src);
                 base::MacEager::expr(cx.expr_str(sp, interned_src))
             }
             Err(_) => {

compiler/rustc_builtin_macros/src/test.rs

@@ -26,7 +26,7 @@ pub fn expand_test_case(
     anno_item: Annotatable,
 ) -> Vec<Annotatable> {
     check_builtin_macro_attribute(ecx, meta_item, sym::test_case);
-    warn_on_duplicate_attribute(&ecx, &anno_item, sym::test_case);
+    warn_on_duplicate_attribute(ecx, &anno_item, sym::test_case);
 
     if !ecx.ecfg.should_test {
         return vec![];
@@ -79,7 +79,7 @@ pub fn expand_test(
     item: Annotatable,
 ) -> Vec<Annotatable> {
     check_builtin_macro_attribute(cx, meta_item, sym::test);
-    warn_on_duplicate_attribute(&cx, &item, sym::test);
+    warn_on_duplicate_attribute(cx, &item, sym::test);
     expand_test_or_bench(cx, attr_sp, item, false)
 }
 
@@ -90,7 +90,7 @@ pub fn expand_bench(
     item: Annotatable,
 ) -> Vec<Annotatable> {
     check_builtin_macro_attribute(cx, meta_item, sym::bench);
-    warn_on_duplicate_attribute(&cx, &item, sym::bench);
+    warn_on_duplicate_attribute(cx, &item, sym::bench);
     expand_test_or_bench(cx, attr_sp, item, true)
 }
 
@@ -134,9 +134,9 @@ pub fn expand_test_or_bench(
     // will fail. We shouldn't try to expand in this case because the errors
     // would be spurious.
     let check_result = if is_bench {
-        check_bench_signature(cx, &item, &fn_)
+        check_bench_signature(cx, &item, fn_)
     } else {
-        check_test_signature(cx, &item, &fn_)
+        check_test_signature(cx, &item, fn_)
     };
     if check_result.is_err() {
         return if is_stmt {

compiler/rustc_builtin_macros/src/test_harness.rs

@@ -60,7 +60,7 @@ pub fn inject(
 
     // Do this here so that the test_runner crate attribute gets marked as used
     // even in non-test builds
-    let test_runner = get_test_runner(span_diagnostic, &krate);
+    let test_runner = get_test_runner(span_diagnostic, krate);
 
     if sess.is_test_crate() {
         let panic_strategy = match (panic_strategy, sess.opts.unstable_opts.panic_abort_tests) {
@@ -372,7 +372,7 @@ fn mk_tests_slice(cx: &TestCtxt<'_>, sp: Span) -> P<ast::Expr> {
     let ecx = &cx.ext_cx;
 
     let mut tests = cx.test_cases.clone();
-    tests.sort_by(|a, b| a.name.as_str().cmp(&b.name.as_str()));
+    tests.sort_by(|a, b| a.name.as_str().cmp(b.name.as_str()));
 
     ecx.expr_array_ref(
         sp,

compiler/rustc_builtin_macros/src/util.rs

@@ -10,7 +10,7 @@ pub fn check_builtin_macro_attribute(ecx: &ExtCtxt<'_>, meta_item: &MetaItem, na
     let template = AttributeTemplate { word: true, ..Default::default() };
     validate_attr::check_builtin_meta_item(
         &ecx.sess.parse_sess,
-        &meta_item,
+        meta_item,
         AttrStyle::Outer,
         name,
         template,

compiler/rustc_codegen_llvm/src/abi.rs

@@ -493,7 +493,7 @@ impl<'ll, 'tcx> FnAbiLlvmExt<'ll, 'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Cast { cast, pad_i32: _ } => {
                 cast.attrs.apply_attrs_to_callsite(
                     llvm::AttributePlace::ReturnValue,
-                    &bx.cx,
+                    bx.cx,
                     callsite,
                 );
             }

compiler/rustc_codegen_llvm/src/allocator.rs

@@ -67,7 +67,7 @@ pub(crate) unsafe fn codegen(
         llcx,
         llmod,
         "__rust_alloc_error_handler",
-        &alloc_error_handler_name(alloc_error_handler_kind),
+        alloc_error_handler_name(alloc_error_handler_kind),
         &[usize, usize], // size, align
         None,
         true,

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -136,7 +136,7 @@ fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> SmallVec<[&'ll Attr
         attrs.push(llvm::CreateAttrStringValue(
             cx.llcx,
             "instrument-function-entry-inlined",
-            &mcount_name,
+            mcount_name,
         ));
     }
     if let Some(options) = &cx.sess().opts.unstable_opts.instrument_xray {
@@ -459,7 +459,7 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         // If this function is an import from the environment but the wasm
         // import has a specific module/name, apply them here.
         if let Some(module) = wasm_import_module(cx.tcx, instance.def_id()) {
-            to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-module", &module));
+            to_add.push(llvm::CreateAttrStringValue(cx.llcx, "wasm-import-module", module));
 
             let name =
                 codegen_fn_attrs.link_name.unwrap_or_else(|| cx.tcx.item_name(instance.def_id()));

compiler/rustc_codegen_llvm/src/back/archive.rs

@@ -68,7 +68,7 @@ impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
     ) -> io::Result<()> {
         let mut archive = archive.to_path_buf();
         if self.sess.target.llvm_target.contains("-apple-macosx") {
-            if let Some(new_archive) = try_extract_macho_fat_archive(&self.sess, &archive)? {
+            if let Some(new_archive) = try_extract_macho_fat_archive(self.sess, &archive)? {
                 archive = new_archive
             }
         }

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -124,7 +124,7 @@ pub fn create_target_machine(tcx: TyCtxt<'_>, mod_name: &str) -> OwnedTargetMach
     let config = TargetMachineFactoryConfig { split_dwarf_file, output_obj_file };
 
     target_machine_factory(
-        &tcx.sess,
+        tcx.sess,
         tcx.backend_optimization_level(()),
         tcx.global_backend_features(()),
     )(config)
@@ -1106,7 +1106,7 @@ fn record_llvm_cgu_instructions_stats(prof: &SelfProfilerRef, llmod: &llvm::Modu
     }
 
     let raw_stats =
-        llvm::build_string(|s| unsafe { llvm::LLVMRustModuleInstructionStats(&llmod, s) })
+        llvm::build_string(|s| unsafe { llvm::LLVMRustModuleInstructionStats(llmod, s) })
             .expect("cannot get module instruction stats");
 
     #[derive(serde::Deserialize)]

compiler/rustc_codegen_llvm/src/callee.rs

@@ -62,7 +62,7 @@ pub fn get_fn<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>, instance: Instance<'tcx>) ->
             // exemption for MinGW for backwards compatibility.
             let llfn = cx.declare_fn(
                 &common::i686_decorated_name(
-                    &dllimport,
+                    dllimport,
                     common::is_mingw_gnu_toolchain(&tcx.sess.target),
                     true,
                 ),

compiler/rustc_codegen_llvm/src/consts.rs

@@ -187,7 +187,7 @@ fn check_and_apply_linkage<'ll, 'tcx>(
     {
         cx.declare_global(
             &common::i686_decorated_name(
-                &dllimport,
+                dllimport,
                 common::is_mingw_gnu_toolchain(&cx.tcx.sess.target),
                 true,
             ),

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs

@@ -176,7 +176,7 @@ impl GlobalFileTable {
         // compilation directory can be combined with the relative paths
         // to get absolute paths, if needed.
         use rustc_session::RemapFileNameExt;
-        let working_dir: &str = &tcx.sess.opts.working_dir.for_codegen(&tcx.sess).to_string_lossy();
+        let working_dir: &str = &tcx.sess.opts.working_dir.for_codegen(tcx.sess).to_string_lossy();
 
         llvm::build_byte_buffer(|buffer| {
             coverageinfo::write_filenames_section_to_buffer(

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -853,7 +853,7 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>(
 
     use rustc_session::RemapFileNameExt;
     let name_in_debuginfo = name_in_debuginfo.to_string_lossy();
-    let work_dir = tcx.sess.opts.working_dir.for_codegen(&tcx.sess).to_string_lossy();
+    let work_dir = tcx.sess.opts.working_dir.for_codegen(tcx.sess).to_string_lossy();
     let flags = "\0";
     let output_filenames = tcx.output_filenames(());
     let split_name = if tcx.sess.target_can_use_split_dwarf() {

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs

@@ -715,7 +715,7 @@ fn build_union_fields_for_direct_tag_coroutine<'ll, 'tcx>(
                 coroutine_type_and_layout,
                 coroutine_type_di_node,
                 coroutine_layout,
-                &common_upvar_names,
+                common_upvar_names,
             );
 
             let span = coroutine_layout.variant_source_info[variant_index].span;

compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs

@@ -197,7 +197,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
                                 coroutine_type_and_layout,
                                 coroutine_type_di_node,
                                 coroutine_layout,
-                                &common_upvar_names,
+                                common_upvar_names,
                             ),
                         source_info,
                     }

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -537,8 +537,7 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
                 if feature_state.is_none() {
                     let rust_feature = supported_features.iter().find_map(|&(rust_feature, _)| {
                         let llvm_features = to_llvm_features(sess, rust_feature);
-                        if llvm_features.contains(&feature)
-                            && !llvm_features.contains(&rust_feature)
+                        if llvm_features.contains(feature) && !llvm_features.contains(rust_feature)
                         {
                             Some(rust_feature)
                         } else {

compiler/rustc_codegen_ssa/src/assert_module_sources.rs

@@ -149,7 +149,7 @@ impl<'tcx> AssertModuleSource<'tcx> {
 
         self.cgu_reuse_tracker.set_expectation(
             cgu_name,
-            &user_path,
+            user_path,
             attr.span,
             expected_reuse,
             comp_kind,

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -175,8 +175,7 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
     ) -> io::Result<()> {
         let mut archive_path = archive_path.to_path_buf();
         if self.sess.target.llvm_target.contains("-apple-macosx") {
-            if let Some(new_archive_path) =
-                try_extract_macho_fat_archive(&self.sess, &archive_path)?
+            if let Some(new_archive_path) = try_extract_macho_fat_archive(self.sess, &archive_path)?
             {
                 archive_path = new_archive_path
             }

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -277,7 +277,7 @@ pub fn each_linked_rlib(
         let crate_name = info.crate_name[&cnum];
         let used_crate_source = &info.used_crate_source[&cnum];
         if let Some((path, _)) = &used_crate_source.rlib {
-            f(cnum, &path);
+            f(cnum, path);
         } else {
             if used_crate_source.rmeta.is_some() {
                 return Err(errors::LinkRlibError::OnlyRmetaFound { crate_name });
@@ -524,7 +524,7 @@ fn link_staticlib<'a>(
                 && !ignored_for_lto(sess, &codegen_results.crate_info, cnum);
 
             let native_libs = codegen_results.crate_info.native_libraries[&cnum].iter();
-            let relevant = native_libs.clone().filter(|lib| relevant_lib(sess, &lib));
+            let relevant = native_libs.clone().filter(|lib| relevant_lib(sess, lib));
             let relevant_libs: FxHashSet<_> = relevant.filter_map(|lib| lib.filename).collect();
 
             let bundled_libs: FxHashSet<_> = native_libs.filter_map(|lib| lib.filename).collect();
@@ -689,7 +689,7 @@ fn link_dwarf_object<'a>(
         // Adding an executable is primarily done to make `thorin` check that all the referenced
         // dwarf objects are found in the end.
         package.add_executable(
-            &executable_out_filename,
+            executable_out_filename,
             thorin::MissingReferencedObjectBehaviour::Skip,
         )?;
 
@@ -945,7 +945,7 @@ fn link_natively<'a>(
                     {
                         let is_vs_installed = windows_registry::find_vs_version().is_ok();
                         let has_linker = windows_registry::find_tool(
-                            &sess.opts.target_triple.triple(),
+                            sess.opts.target_triple.triple(),
                             "link.exe",
                         )
                         .is_some();
@@ -1038,14 +1038,14 @@ fn link_natively<'a>(
     if sess.target.is_like_osx {
         match (strip, crate_type) {
             (Strip::Debuginfo, _) => {
-                strip_symbols_with_external_utility(sess, "strip", &out_filename, Some("-S"))
+                strip_symbols_with_external_utility(sess, "strip", out_filename, Some("-S"))
             }
             // Per the manpage, `-x` is the maximum safe strip level for dynamic libraries. (#93988)
             (Strip::Symbols, CrateType::Dylib | CrateType::Cdylib | CrateType::ProcMacro) => {
-                strip_symbols_with_external_utility(sess, "strip", &out_filename, Some("-x"))
+                strip_symbols_with_external_utility(sess, "strip", out_filename, Some("-x"))
             }
             (Strip::Symbols, _) => {
-                strip_symbols_with_external_utility(sess, "strip", &out_filename, None)
+                strip_symbols_with_external_utility(sess, "strip", out_filename, None)
             }
             (Strip::None, _) => {}
         }
@@ -1059,7 +1059,7 @@ fn link_natively<'a>(
         match strip {
             // Always preserve the symbol table (-x).
             Strip::Debuginfo => {
-                strip_symbols_with_external_utility(sess, stripcmd, &out_filename, Some("-x"))
+                strip_symbols_with_external_utility(sess, stripcmd, out_filename, Some("-x"))
             }
             // Strip::Symbols is handled via the --strip-all linker option.
             Strip::Symbols => {}
@@ -1245,13 +1245,13 @@ fn link_sanitizer_runtime(sess: &Session, linker: &mut dyn Linker, name: &str) {
         // rpath to the library as well (the rpath should be absolute, see
         // PR #41352 for details).
         let filename = format!("rustc{channel}_rt.{name}");
-        let path = find_sanitizer_runtime(&sess, &filename);
+        let path = find_sanitizer_runtime(sess, &filename);
         let rpath = path.to_str().expect("non-utf8 component in path");
         linker.args(&["-Wl,-rpath", "-Xlinker", rpath]);
         linker.link_dylib(&filename, false, true);
     } else {
         let filename = format!("librustc{channel}_rt.{name}.a");
-        let path = find_sanitizer_runtime(&sess, &filename).join(&filename);
+        let path = find_sanitizer_runtime(sess, &filename).join(&filename);
         linker.link_whole_rlib(&path);
     }
 }
@@ -1685,7 +1685,7 @@ fn link_output_kind(sess: &Session, crate_type: CrateType) -> LinkOutputKind {
 
 // Returns true if linker is located within sysroot
 fn detect_self_contained_mingw(sess: &Session) -> bool {
-    let (linker, _) = linker_and_flavor(&sess);
+    let (linker, _) = linker_and_flavor(sess);
     // Assume `-C linker=rust-lld` as self-contained mode
     if linker == Path::new("rust-lld") {
         return true;
@@ -1737,7 +1737,7 @@ fn self_contained_components(sess: &Session, crate_type: CrateType) -> LinkSelfC
                 LinkSelfContainedDefault::InferredForMingw => {
                     sess.host == sess.target
                         && sess.target.vendor != "uwp"
-                        && detect_self_contained_mingw(&sess)
+                        && detect_self_contained_mingw(sess)
                 }
             }
         };
@@ -2432,7 +2432,7 @@ fn add_native_libs_from_crate(
         // If rlib contains native libs as archives, unpack them to tmpdir.
         let rlib = &codegen_results.crate_info.used_crate_source[&cnum].rlib.as_ref().unwrap().0;
         archive_builder_builder
-            .extract_bundled_libs(rlib, tmpdir, &bundled_libs)
+            .extract_bundled_libs(rlib, tmpdir, bundled_libs)
             .unwrap_or_else(|e| sess.emit_fatal(e));
     }
 
@@ -2485,7 +2485,7 @@ fn add_native_libs_from_crate(
                             cmd.link_whole_staticlib(
                                 name,
                                 verbatim,
-                                &search_paths.get_or_init(|| archive_search_paths(sess)),
+                                search_paths.get_or_init(|| archive_search_paths(sess)),
                             );
                         } else {
                             cmd.link_staticlib(name, verbatim)
@@ -2719,7 +2719,7 @@ fn rehome_sysroot_lib_dir<'a>(sess: &'a Session, lib_dir: &Path) -> PathBuf {
         // already had `fix_windows_verbatim_for_gcc()` applied if needed.
         sysroot_lib_path
     } else {
-        fix_windows_verbatim_for_gcc(&lib_dir)
+        fix_windows_verbatim_for_gcc(lib_dir)
     }
 }
 
@@ -2756,7 +2756,7 @@ fn add_static_crate<'a>(
     let mut link_upstream = |path: &Path| {
         let rlib_path = if let Some(dir) = path.parent() {
             let file_name = path.file_name().expect("rlib path has no file name path component");
-            rehome_sysroot_lib_dir(sess, &dir).join(file_name)
+            rehome_sysroot_lib_dir(sess, dir).join(file_name)
         } else {
             fix_windows_verbatim_for_gcc(path)
         };
@@ -2793,7 +2793,7 @@ fn add_static_crate<'a>(
                 let canonical = f.replace('-', "_");
 
                 let is_rust_object =
-                    canonical.starts_with(&canonical_name) && looks_like_rust_object_file(&f);
+                    canonical.starts_with(&canonical_name) && looks_like_rust_object_file(f);
 
                 // If we're performing LTO and this is a rust-generated object
                 // file, then we don't need the object file as it's part of the

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -45,7 +45,7 @@ pub fn get_linker<'a>(
     self_contained: bool,
     target_cpu: &'a str,
 ) -> Box<dyn Linker + 'a> {
-    let msvc_tool = windows_registry::find_tool(&sess.opts.target_triple.triple(), "link.exe");
+    let msvc_tool = windows_registry::find_tool(sess.opts.target_triple.triple(), "link.exe");
 
     // If our linker looks like a batch script on Windows then to execute this
     // we'll need to spawn `cmd` explicitly. This is primarily done to handle
@@ -78,7 +78,7 @@ pub fn get_linker<'a>(
     if matches!(flavor, LinkerFlavor::Msvc(..)) && t.vendor == "uwp" {
         if let Some(ref tool) = msvc_tool {
             let original_path = tool.path();
-            if let Some(ref root_lib_path) = original_path.ancestors().nth(4) {
+            if let Some(root_lib_path) = original_path.ancestors().nth(4) {
                 let arch = match t.arch.as_ref() {
                     "x86_64" => Some("x64"),
                     "x86" => Some("x86"),
@@ -519,7 +519,7 @@ impl<'a> Linker for GccLinker<'a> {
             // -force_load is the macOS equivalent of --whole-archive, but it
             // involves passing the full path to the library to link.
             self.linker_arg("-force_load");
-            let lib = find_native_static_library(lib, verbatim, search_path, &self.sess);
+            let lib = find_native_static_library(lib, verbatim, search_path, self.sess);
             self.linker_arg(&lib);
         }
     }
@@ -1590,7 +1590,7 @@ impl<'a> Linker for AixLinker<'a> {
 
     fn link_whole_staticlib(&mut self, lib: &str, verbatim: bool, search_path: &[PathBuf]) {
         self.hint_static();
-        let lib = find_native_static_library(lib, verbatim, search_path, &self.sess);
+        let lib = find_native_static_library(lib, verbatim, search_path, self.sess);
         self.cmd.arg(format!("-bkeepfile:{}", lib.to_str().unwrap()));
     }
 

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -621,7 +621,7 @@ fn wasm_import_module_map(tcx: TyCtxt<'_>, cnum: CrateNum) -> FxHashMap<DefId, S
 
     let mut ret = FxHashMap::default();
     for (def_id, lib) in tcx.foreign_modules(cnum).iter() {
-        let module = def_id_to_native_lib.get(&def_id).and_then(|s| s.wasm_import_module());
+        let module = def_id_to_native_lib.get(def_id).and_then(|s| s.wasm_import_module());
         let Some(module) = module else { continue };
         ret.extend(lib.foreign_items.iter().map(|id| {
             assert_eq!(id.krate, cnum);

compiler/rustc_codegen_ssa/src/back/write.rs

@@ -892,7 +892,7 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
     let incr_comp_session_dir = cgcx.incr_comp_session_dir.as_ref().unwrap();
 
     let load_from_incr_comp_dir = |output_path: PathBuf, saved_path: &str| {
-        let source_file = in_incr_comp_dir(&incr_comp_session_dir, saved_path);
+        let source_file = in_incr_comp_dir(incr_comp_session_dir, saved_path);
         debug!(
             "copying preexisting module `{}` from {:?} to {}",
             module.name,
@@ -914,7 +914,7 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
 
     let object = load_from_incr_comp_dir(
         cgcx.output_filenames.temp_path(OutputType::Object, Some(&module.name)),
-        &module.source.saved_files.get("o").expect("no saved object file in work product"),
+        module.source.saved_files.get("o").expect("no saved object file in work product"),
     );
     let dwarf_object =
         module.source.saved_files.get("dwo").as_ref().and_then(|saved_dwarf_object_file| {
@@ -924,7 +924,7 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
                 .expect(
                     "saved dwarf object in work product but `split_dwarf_path` returned `None`",
                 );
-            load_from_incr_comp_dir(dwarf_obj_out, &saved_dwarf_object_file)
+            load_from_incr_comp_dir(dwarf_obj_out, saved_dwarf_object_file)
         });
 
     WorkItemResult::Finished(CompiledModule {

compiler/rustc_codegen_ssa/src/base.rs

@@ -148,10 +148,9 @@ pub fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         (&ty::Array(_, len), &ty::Slice(_)) => {
             cx.const_usize(len.eval_target_usize(cx.tcx(), ty::ParamEnv::reveal_all()))
         }
-        (
-            &ty::Dynamic(ref data_a, _, src_dyn_kind),
-            &ty::Dynamic(ref data_b, _, target_dyn_kind),
-        ) if src_dyn_kind == target_dyn_kind => {
+        (&ty::Dynamic(data_a, _, src_dyn_kind), &ty::Dynamic(data_b, _, target_dyn_kind))
+            if src_dyn_kind == target_dyn_kind =>
+        {
             let old_info =
                 old_info.expect("unsized_info: missing old info for trait upcasting coercion");
             if data_a.principal_def_id() == data_b.principal_def_id() {
@@ -458,8 +457,8 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         cx.set_frame_pointer_type(llfn);
         cx.apply_target_cpu_attr(llfn);
 
-        let llbb = Bx::append_block(&cx, llfn, "top");
-        let mut bx = Bx::build(&cx, llbb);
+        let llbb = Bx::append_block(cx, llfn, "top");
+        let mut bx = Bx::build(cx, llbb);
 
         bx.insert_reference_to_gdb_debug_scripts_section_global();
 
@@ -685,7 +684,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
 
     // Calculate the CGU reuse
     let cgu_reuse = tcx.sess.time("find_cgu_reuse", || {
-        codegen_units.iter().map(|cgu| determine_cgu_reuse(tcx, &cgu)).collect::<Vec<_>>()
+        codegen_units.iter().map(|cgu| determine_cgu_reuse(tcx, cgu)).collect::<Vec<_>>()
     });
 
     crate::assert_module_sources::assert_module_sources(tcx, &|cgu_reuse_tracker| {

compiler/rustc_codegen_ssa/src/codegen_attrs.rs

@@ -477,9 +477,9 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                     )
                     .emit();
                     InlineAttr::None
-                } else if list_contains_name(&items, sym::always) {
+                } else if list_contains_name(items, sym::always) {
                     InlineAttr::Always
-                } else if list_contains_name(&items, sym::never) {
+                } else if list_contains_name(items, sym::never) {
                     InlineAttr::Never
                 } else {
                     struct_span_err!(
@@ -514,9 +514,9 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
                 if items.len() != 1 {
                     err(attr.span, "expected one argument");
                     OptimizeAttr::None
-                } else if list_contains_name(&items, sym::size) {
+                } else if list_contains_name(items, sym::size) {
                     OptimizeAttr::Size
-                } else if list_contains_name(&items, sym::speed) {
+                } else if list_contains_name(items, sym::speed) {
                     OptimizeAttr::Speed
                 } else {
                     err(items[0].span(), "invalid argument");

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -216,7 +216,7 @@ fn push_debuginfo_type_name<'tcx>(
                 output.push(']');
             }
         }
-        ty::Dynamic(ref trait_data, ..) => {
+        ty::Dynamic(trait_data, ..) => {
             let auto_traits: SmallVec<[DefId; 4]> = trait_data.auto_traits().collect();
 
             let has_enclosing_parens = if cpp_like_debuginfo {

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -42,7 +42,7 @@ pub fn non_ssa_locals<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     // If there exists a local definition that dominates all uses of that local,
     // the definition should be visited first. Traverse blocks in an order that
     // is a topological sort of dominance partial order.
-    for (bb, data) in traversal::reverse_postorder(&mir) {
+    for (bb, data) in traversal::reverse_postorder(mir) {
         analyzer.visit_basic_block_data(bb, data);
     }
 
@@ -202,7 +202,7 @@ impl<'mir, 'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> Visitor<'tcx>
             ) => match &mut self.locals[local] {
                 LocalKind::ZST => {}
                 LocalKind::Memory => {}
-                LocalKind::SSA(def) if def.dominates(location, &self.dominators) => {}
+                LocalKind::SSA(def) if def.dominates(location, self.dominators) => {}
                 // Reads from uninitialized variables (e.g., in dead code, after
                 // optimizations) require locals to be in (uninitialized) memory.
                 // N.B., there can be uninitialized reads of a local visited after

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -47,7 +47,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
         &self,
         fx: &'b mut FunctionCx<'a, 'tcx, Bx>,
     ) -> Option<&'b Bx::Funclet> {
-        let cleanup_kinds = (&fx.cleanup_kinds).as_ref()?;
+        let cleanup_kinds = fx.cleanup_kinds.as_ref()?;
         let funclet_bb = cleanup_kinds[self.bb].funclet_bb(self.bb)?;
         // If `landing_pad_for` hasn't been called yet to create the `Funclet`,
         // it has to be now. This may not seem necessary, as RPO should lead
@@ -161,7 +161,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
     ) -> MergingSucc {
         // If there is a cleanup block and the function we're calling can unwind, then
         // do an invoke, otherwise do a call.
-        let fn_ty = bx.fn_decl_backend_type(&fn_abi);
+        let fn_ty = bx.fn_decl_backend_type(fn_abi);
 
         let fn_attrs = if bx.tcx().def_kind(fx.instance.def_id()).has_codegen_attrs() {
             Some(bx.tcx().codegen_fn_attrs(fx.instance.def_id()))
@@ -204,9 +204,9 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
             let invokeret = bx.invoke(
                 fn_ty,
                 fn_attrs,
-                Some(&fn_abi),
+                Some(fn_abi),
                 fn_ptr,
-                &llargs,
+                llargs,
                 ret_llbb,
                 unwind_block,
                 self.funclet(fx),
@@ -225,7 +225,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
             }
             MergingSucc::False
         } else {
-            let llret = bx.call(fn_ty, fn_attrs, Some(&fn_abi), fn_ptr, &llargs, self.funclet(fx));
+            let llret = bx.call(fn_ty, fn_attrs, Some(fn_abi), fn_ptr, llargs, self.funclet(fx));
             if fx.mir[self.bb].is_cleanup {
                 bx.apply_attrs_to_cleanup_callsite(llret);
             }
@@ -273,7 +273,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
 
             bx.codegen_inline_asm(
                 template,
-                &operands,
+                operands,
                 options,
                 line_spans,
                 instance,
@@ -281,7 +281,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
             );
             MergingSucc::False
         } else {
-            bx.codegen_inline_asm(template, &operands, options, line_spans, instance, None);
+            bx.codegen_inline_asm(template, operands, options, line_spans, instance, None);
 
             if let Some(target) = destination {
                 self.funclet_br(fx, bx, target, mergeable_succ)
@@ -318,7 +318,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         discr: &mir::Operand<'tcx>,
         targets: &SwitchTargets,
     ) {
-        let discr = self.codegen_operand(bx, &discr);
+        let discr = self.codegen_operand(bx, discr);
         let switch_ty = discr.layout.ty;
         let mut target_iter = targets.iter();
         if target_iter.len() == 1 {
@@ -498,7 +498,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     args = &args[..1];
                     (
                         meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE)
-                            .get_fn(bx, vtable, ty, &fn_abi),
+                            .get_fn(bx, vtable, ty, fn_abi),
                         fn_abi,
                     )
                 }
@@ -540,7 +540,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     debug!("args' = {:?}", args);
                     (
                         meth::VirtualIndex::from_index(ty::COMMON_VTABLE_ENTRIES_DROPINPLACE)
-                            .get_fn(bx, meta.immediate(), ty, &fn_abi),
+                            .get_fn(bx, meta.immediate(), ty, fn_abi),
                         fn_abi,
                     )
                 }
@@ -864,7 +864,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         // promotes any complex rvalues to constants.
                         if i == 2 && intrinsic == sym::simd_shuffle {
                             if let mir::Operand::Constant(constant) = arg {
-                                let (llval, ty) = self.simd_shuffle_indices(&bx, constant);
+                                let (llval, ty) = self.simd_shuffle_indices(bx, constant);
                                 return OperandRef {
                                     val: Immediate(llval),
                                     layout: bx.layout_of(ty),
@@ -881,7 +881,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 Self::codegen_intrinsic_call(
                     bx,
                     *instance.as_ref().unwrap(),
-                    &fn_abi,
+                    fn_abi,
                     &args,
                     dest,
                     span,
@@ -937,7 +937,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             bx,
                             meta,
                             op.layout.ty,
-                            &fn_abi,
+                            fn_abi,
                         ));
                         llargs.push(data_ptr);
                         continue 'make_args;
@@ -948,7 +948,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             bx,
                             meta,
                             op.layout.ty,
-                            &fn_abi,
+                            fn_abi,
                         ));
                         llargs.push(data_ptr);
                         continue;
@@ -975,7 +975,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                             bx,
                             meta.immediate(),
                             op.layout.ty,
-                            &fn_abi,
+                            fn_abi,
                         ));
                         llargs.push(data_ptr.llval);
                         continue;
@@ -1587,9 +1587,9 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         self.set_debug_loc(&mut bx, mir::SourceInfo::outermost(self.mir.span));
 
         let (fn_abi, fn_ptr) = common::build_langcall(&bx, None, reason.lang_item());
-        let fn_ty = bx.fn_decl_backend_type(&fn_abi);
+        let fn_ty = bx.fn_decl_backend_type(fn_abi);
 
-        let llret = bx.call(fn_ty, None, Some(&fn_abi), fn_ptr, &[], funclet.as_ref());
+        let llret = bx.call(fn_ty, None, Some(fn_abi), fn_ptr, &[], funclet.as_ref());
         bx.apply_attrs_to_cleanup_callsite(llret);
 
         bx.unreachable();
@@ -1662,10 +1662,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 }
             }
         } else {
-            self.codegen_place(
-                bx,
-                mir::PlaceRef { local: dest.local, projection: &dest.projection },
-            )
+            self.codegen_place(bx, mir::PlaceRef { local: dest.local, projection: dest.projection })
         };
         if fn_ret.is_indirect() {
             if dest.align < dest.layout.align.abi {
@@ -1696,7 +1693,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         match dest {
             Nothing => (),
-            Store(dst) => bx.store_arg(&ret_abi, llval, dst),
+            Store(dst) => bx.store_arg(ret_abi, llval, dst),
             IndirectOperand(tmp, index) => {
                 let op = bx.load_operand(tmp);
                 tmp.storage_dead(bx);
@@ -1708,7 +1705,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 let op = if let PassMode::Cast { .. } = ret_abi.mode {
                     let tmp = PlaceRef::alloca(bx, ret_abi.layout);
                     tmp.storage_live(bx);
-                    bx.store_arg(&ret_abi, llval, tmp);
+                    bx.store_arg(ret_abi, llval, tmp);
                     let op = bx.load_operand(tmp);
                     tmp.storage_dead(bx);
                     op

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -398,7 +398,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let Some(dbg_loc) = self.dbg_loc(var.source_info) else { return };
 
         let DebugInfoOffset { direct_offset, indirect_offsets, result: _ } =
-            calculate_debuginfo_offset(bx, &var.projection, base.layout);
+            calculate_debuginfo_offset(bx, var.projection, base.layout);
 
         // When targeting MSVC, create extra allocas for arguments instead of pointing multiple
         // dbg_var_addr() calls into the same alloca with offsets. MSVC uses CodeView records
@@ -416,7 +416,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
         if should_create_individual_allocas {
             let DebugInfoOffset { direct_offset: _, indirect_offsets: _, result: place } =
-                calculate_debuginfo_offset(bx, &var.projection, base);
+                calculate_debuginfo_offset(bx, var.projection, base);
 
             // Create a variable which will be a pointer to the actual value
             let ptr_ty = Ty::new_ptr(

compiler/rustc_codegen_ssa/src/mir/mod.rs

@@ -168,7 +168,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     let fn_abi = cx.fn_abi_of_instance(instance, ty::List::empty());
     debug!("fn_abi: {:?}", fn_abi);
 
-    let debug_context = cx.create_function_debug_context(instance, &fn_abi, llfn, &mir);
+    let debug_context = cx.create_function_debug_context(instance, fn_abi, llfn, mir);
 
     let start_llbb = Bx::append_block(cx, llfn, "start");
     let mut start_bx = Bx::build(cx, start_llbb);
@@ -180,7 +180,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     }
 
     let cleanup_kinds =
-        base::wants_new_eh_instructions(cx.tcx().sess).then(|| analyze::cleanup_kinds(&mir));
+        base::wants_new_eh_instructions(cx.tcx().sess).then(|| analyze::cleanup_kinds(mir));
 
     let cached_llbbs: IndexVec<mir::BasicBlock, CachedLlbb<Bx::BasicBlock>> =
         mir.basic_blocks
@@ -261,7 +261,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     drop(start_bx);
 
     // Codegen the body of each block using reverse postorder
-    for (bb, _) in traversal::reverse_postorder(&mir) {
+    for (bb, _) in traversal::reverse_postorder(mir) {
         fx.codegen_block(bb);
     }
 }

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -702,7 +702,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     };
                     let fn_ptr = bx.get_fn_addr(instance);
                     let fn_abi = bx.fn_abi_of_instance(instance, ty::List::empty());
-                    let fn_ty = bx.fn_decl_backend_type(&fn_abi);
+                    let fn_ty = bx.fn_decl_backend_type(fn_abi);
                     let fn_attrs = if bx.tcx().def_kind(instance.def_id()).has_codegen_attrs() {
                         Some(bx.tcx().codegen_fn_attrs(instance.def_id()))
                     } else {

compiler/rustc_codegen_ssa/src/mono_item.rs

@@ -34,7 +34,7 @@ impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
             }
             MonoItem::GlobalAsm(item_id) => {
                 let item = cx.tcx().hir().item(item_id);
-                if let hir::ItemKind::GlobalAsm(ref asm) = item.kind {
+                if let hir::ItemKind::GlobalAsm(asm) = item.kind {
                     let operands: Vec<_> = asm
                         .operands
                         .iter()
@@ -88,7 +88,7 @@ impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
                 }
             }
             MonoItem::Fn(instance) => {
-                base::codegen_instance::<Bx>(&cx, instance);
+                base::codegen_instance::<Bx>(cx, instance);
             }
         }
 
@@ -119,10 +119,10 @@ impl<'a, 'tcx: 'a> MonoItemExt<'a, 'tcx> for MonoItem<'tcx> {
 
         match *self {
             MonoItem::Static(def_id) => {
-                cx.predefine_static(def_id, linkage, visibility, &symbol_name);
+                cx.predefine_static(def_id, linkage, visibility, symbol_name);
             }
             MonoItem::Fn(instance) => {
-                cx.predefine_fn(instance, linkage, visibility, &symbol_name);
+                cx.predefine_fn(instance, linkage, visibility, symbol_name);
             }
             MonoItem::GlobalAsm(..) => {}
         }

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -314,7 +314,7 @@ pub fn eval_in_interpreter<'mir, 'tcx>(
     is_static: bool,
 ) -> ::rustc_middle::mir::interpret::EvalToAllocationRawResult<'tcx> {
     let res = ecx.load_mir(cid.instance.def, cid.promoted);
-    match res.and_then(|body| eval_body_using_ecx(&mut ecx, cid, &body)) {
+    match res.and_then(|body| eval_body_using_ecx(&mut ecx, cid, body)) {
         Err(error) => {
             let (error, backtrace) = error.into_parts();
             backtrace.print_backtrace();

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -200,7 +200,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
                 &caller
                     .file
                     .name
-                    .for_scope(&self.tcx.sess, RemapPathScopeComponents::DIAGNOSTICS)
+                    .for_scope(self.tcx.sess, RemapPathScopeComponents::DIAGNOSTICS)
                     .to_string_lossy(),
             ),
             u32::try_from(caller.line).unwrap(),

compiler/rustc_const_eval/src/const_eval/valtrees.rs

@@ -387,7 +387,7 @@ fn valtree_into_mplace<'tcx>(
 
                 debug!(?place_inner);
                 valtree_into_mplace(ecx, &place_inner, *inner_valtree);
-                dump_place(&ecx, &place_inner);
+                dump_place(ecx, &place_inner);
             }
 
             debug!("dump of place_adjusted:");

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -256,7 +256,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         let addr = addr.to_target_usize(self)?;
 
         // Then turn address into pointer.
-        let ptr = M::ptr_from_addr_cast(&self, addr)?;
+        let ptr = M::ptr_from_addr_cast(self, addr)?;
         Ok(ImmTy::from_scalar(Scalar::from_maybe_pointer(ptr, self), cast_to))
     }
 

compiler/rustc_const_eval/src/interpret/intern.rs

@@ -259,7 +259,7 @@ impl<'rt, 'mir, 'tcx: 'mir, M: CompileTimeMachine<'mir, 'tcx, const_eval::Memory
                 // to avoid could be expensive: on the potentially larger types, arrays and slices,
                 // rather than on all aggregates unconditionally.
                 if matches!(mplace.layout.ty.kind(), ty::Array(..) | ty::Slice(..)) {
-                    let Some((size, _align)) = self.ecx.size_and_align_of_mplace(&mplace)? else {
+                    let Some((size, _align)) = self.ecx.size_and_align_of_mplace(mplace)? else {
                         // We do the walk if we can't determine the size of the mplace: we may be
                         // dealing with extern types here in the future.
                         return Ok(true);

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -505,7 +505,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // Performs an exact division, resulting in undefined behavior where
         // `x % y != 0` or `y == 0` or `x == T::MIN && y == -1`.
         // First, check x % y != 0 (or if that computation overflows).
-        let (res, overflow) = self.overflowing_binary_op(BinOp::Rem, &a, &b)?;
+        let (res, overflow) = self.overflowing_binary_op(BinOp::Rem, a, b)?;
         assert!(!overflow); // All overflow is UB, so this should never return on overflow.
         if res.to_scalar().assert_bits(a.layout.size) != 0 {
             throw_ub_custom!(
@@ -515,7 +515,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             )
         }
         // `Rem` says this is all right, so we can let `Div` do its job.
-        self.binop_ignore_overflow(BinOp::Div, &a, &b, dest)
+        self.binop_ignore_overflow(BinOp::Div, a, b, dest)
     }
 
     pub fn saturating_arith(

compiler/rustc_const_eval/src/interpret/operator.rs

@@ -20,7 +20,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         right: &ImmTy<'tcx, M::Provenance>,
         dest: &PlaceTy<'tcx, M::Provenance>,
     ) -> InterpResult<'tcx> {
-        let (val, overflowed) = self.overflowing_binary_op(op, &left, &right)?;
+        let (val, overflowed) = self.overflowing_binary_op(op, left, right)?;
         debug_assert_eq!(
             Ty::new_tup(self.tcx.tcx, &[val.layout.ty, self.tcx.types.bool]),
             dest.layout.ty,

compiler/rustc_const_eval/src/interpret/place.rs

@@ -456,7 +456,7 @@ where
     ) -> InterpResult<'tcx, Option<AllocRef<'_, 'tcx, M::Provenance, M::AllocExtra, M::Bytes>>>
     {
         let (size, _align) = self
-            .size_and_align_of_mplace(&mplace)?
+            .size_and_align_of_mplace(mplace)?
             .unwrap_or((mplace.layout.size, mplace.layout.align.abi));
         // We check alignment separately, and *after* checking everything else.
         // If an access is both OOB and misaligned, we want to see the bounds error.
@@ -472,7 +472,7 @@ where
     ) -> InterpResult<'tcx, Option<AllocRefMut<'_, 'tcx, M::Provenance, M::AllocExtra, M::Bytes>>>
     {
         let (size, _align) = self
-            .size_and_align_of_mplace(&mplace)?
+            .size_and_align_of_mplace(mplace)?
             .unwrap_or((mplace.layout.size, mplace.layout.align.abi));
         // We check alignment separately, and raise that error *after* checking everything else.
         // If an access is both OOB and misaligned, we want to see the bounds error.

compiler/rustc_const_eval/src/interpret/terminator.rs

@@ -51,7 +51,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
         match arg {
             FnArg::Copy(op) => Ok(op.clone()),
-            FnArg::InPlace(place) => self.place_to_op(&place),
+            FnArg::InPlace(place) => self.place_to_op(place),
         }
     }
 
@@ -410,7 +410,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // so we implement a type-based check that reflects the guaranteed rules for ABI compatibility.
         if self.layout_compat(caller_abi.layout, callee_abi.layout)? {
             // Ensure that our checks imply actual ABI compatibility for this concrete call.
-            assert!(caller_abi.eq_abi(&callee_abi));
+            assert!(caller_abi.eq_abi(callee_abi));
             return Ok(true);
         } else {
             trace!(
@@ -464,7 +464,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // We work with a copy of the argument for now; if this is in-place argument passing, we
         // will later protect the source it comes from. This means the callee cannot observe if we
         // did in-place of by-copy argument passing, except for pointer equality tests.
-        let caller_arg_copy = self.copy_fn_arg(&caller_arg)?;
+        let caller_arg_copy = self.copy_fn_arg(caller_arg)?;
         if !already_live {
             let local = callee_arg.as_local().unwrap();
             let meta = caller_arg_copy.meta();

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -896,7 +896,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         let mut visitor = ValidityVisitor { path, ref_tracking, ctfe_mode, ecx: self };
 
         // Run it.
-        match visitor.visit_value(&op) {
+        match visitor.visit_value(op) {
             Ok(()) => Ok(()),
             // Pass through validation failures and "invalid program" issues.
             Err(err)

compiler/rustc_const_eval/src/interpret/visitor.rs

@@ -97,14 +97,14 @@ pub trait ValueVisitor<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>>: Sized {
                 let inner_mplace = self.ecx().unpack_dyn_trait(&dest)?.0;
                 trace!("walk_value: dyn object layout: {:#?}", inner_mplace.layout);
                 // recurse with the inner type
-                return self.visit_field(&v, 0, &inner_mplace.into());
+                return self.visit_field(v, 0, &inner_mplace.into());
             }
             ty::Dynamic(_, _, ty::DynStar) => {
                 // DynStar types. Very different from a dyn type (but strangely part of the
                 // same variant in `TyKind`): These are pairs where the 2nd component is the
                 // vtable, and the first component is the data (which must be ptr-sized).
                 let data = self.ecx().unpack_dyn_star(v)?.0;
-                return self.visit_field(&v, 0, &data);
+                return self.visit_field(v, 0, &data);
             }
             // Slices do not need special handling here: they have `Array` field
             // placement with length 0, so we enter the `Array` case below which

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -60,9 +60,9 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
             let ConstCx { tcx, body, .. } = *ccx;
 
             FlowSensitiveAnalysis::new(NeedsDrop, ccx)
-                .into_engine(tcx, &body)
+                .into_engine(tcx, body)
                 .iterate_to_fixpoint()
-                .into_results_cursor(&body)
+                .into_results_cursor(body)
         });
 
         needs_drop.seek_before_primary_effect(location);
@@ -122,9 +122,9 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
             let ConstCx { tcx, body, .. } = *ccx;
 
             FlowSensitiveAnalysis::new(HasMutInterior, ccx)
-                .into_engine(tcx, &body)
+                .into_engine(tcx, body)
                 .iterate_to_fixpoint()
-                .into_results_cursor(&body)
+                .into_results_cursor(body)
         });
 
         has_mut_interior.seek_before_primary_effect(location);
@@ -170,9 +170,9 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> {
 
             hir::ConstContext::Const { .. } | hir::ConstContext::Static(_) => {
                 let mut cursor = FlowSensitiveAnalysis::new(CustomEq, ccx)
-                    .into_engine(ccx.tcx, &ccx.body)
+                    .into_engine(ccx.tcx, ccx.body)
                     .iterate_to_fixpoint()
-                    .into_results_cursor(&ccx.body);
+                    .into_results_cursor(ccx.body);
 
                 cursor.seek_after_primary_effect(return_loc);
                 cursor.get().contains(RETURN_PLACE)
@@ -225,7 +225,7 @@ impl<'mir, 'tcx> Deref for Checker<'mir, 'tcx> {
     type Target = ConstCx<'mir, 'tcx>;
 
     fn deref(&self) -> &Self::Target {
-        &self.ccx
+        self.ccx
     }
 }
 
@@ -272,7 +272,7 @@ impl<'mir, 'tcx> Checker<'mir, 'tcx> {
         }
 
         if !tcx.has_attr(def_id, sym::rustc_do_not_const_check) {
-            self.visit_body(&body);
+            self.visit_body(body);
         }
 
         // If we got through const-checking without emitting any "primary" errors, emit any
@@ -503,7 +503,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
             Rvalue::Ref(_, BorrowKind::Shared | BorrowKind::Fake, place)
             | Rvalue::AddressOf(Mutability::Not, place) => {
                 let borrowed_place_has_mut_interior = qualifs::in_place::<HasMutInterior, _>(
-                    &self.ccx,
+                    self.ccx,
                     &mut |local| self.qualifs.has_mut_interior(self.ccx, local, location),
                     place.as_ref(),
                 );

compiler/rustc_const_eval/src/transform/check_consts/mod.rs

@@ -83,7 +83,7 @@ pub fn rustc_allow_const_fn_unstable(
     feature_gate: Symbol,
 ) -> bool {
     let attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(def_id));
-    attr::rustc_allow_const_fn_unstable(&tcx.sess, attrs).any(|name| name == feature_gate)
+    attr::rustc_allow_const_fn_unstable(tcx.sess, attrs).any(|name| name == feature_gate)
 }
 
 /// Returns `true` if the given `const fn` is "const-stable".

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -129,7 +129,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
                             tcx,
                             generics,
                             err,
-                            &param_ty.name.as_str(),
+                            param_ty.name.as_str(),
                             &constraint,
                             None,
                             None,

compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs

@@ -54,7 +54,7 @@ impl<'mir, 'tcx> std::ops::Deref for CheckLiveDrops<'mir, 'tcx> {
     type Target = ConstCx<'mir, 'tcx>;
 
     fn deref(&self) -> &Self::Target {
-        &self.ccx
+        self.ccx
     }
 }
 

compiler/rustc_const_eval/src/transform/promote_consts.rs

@@ -188,7 +188,7 @@ impl<'a, 'tcx> std::ops::Deref for Validator<'a, 'tcx> {
     type Target = ConstCx<'a, 'tcx>;
 
     fn deref(&self) -> &Self::Target {
-        &self.ccx
+        self.ccx
     }
 }
 
@@ -229,7 +229,7 @@ impl<'tcx> Validator<'_, 'tcx> {
                 let statement = &self.body[loc.block].statements[loc.statement_index];
                 match &statement.kind {
                     StatementKind::Assign(box (_, rhs)) => qualifs::in_rvalue::<Q, _>(
-                        &self.ccx,
+                        self.ccx,
                         &mut |l| self.qualif_local::<Q>(l),
                         rhs,
                     ),
@@ -246,7 +246,7 @@ impl<'tcx> Validator<'_, 'tcx> {
                 match &terminator.kind {
                     TerminatorKind::Call { .. } => {
                         let return_ty = self.body.local_decls[local].ty;
-                        Q::in_any_value_of_ty(&self.ccx, return_ty)
+                        Q::in_any_value_of_ty(self.ccx, return_ty)
                     }
                     kind => {
                         span_bug!(terminator.source_info.span, "{:?} not promotable", kind);

compiler/rustc_data_structures/src/sharded.rs

@@ -50,7 +50,7 @@ impl<T> Sharded<T> {
     #[inline]
     pub fn get_shard_by_value<K: Hash + ?Sized>(&self, _val: &K) -> &Lock<T> {
         match self {
-            Self::Single(single) => &single,
+            Self::Single(single) => single,
             #[cfg(parallel_compiler)]
             Self::Shards(..) => self.get_shard_by_hash(make_hash(_val)),
         }
@@ -64,7 +64,7 @@ impl<T> Sharded<T> {
     #[inline]
     pub fn get_shard_by_index(&self, _i: usize) -> &Lock<T> {
         match self {
-            Self::Single(single) => &single,
+            Self::Single(single) => single,
             #[cfg(parallel_compiler)]
             Self::Shards(shards) => {
                 // SAFETY: The index gets ANDed with the shard mask, ensuring it is always inbounds.

compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs

@@ -138,7 +138,7 @@ impl AnnotateSnippetEmitterWriter {
         let message = self.translate_messages(messages, args);
         if let Some(source_map) = &self.source_map {
             // Make sure our primary file comes first
-            let primary_lo = if let Some(ref primary_span) = msp.primary_span().as_ref() {
+            let primary_lo = if let Some(primary_span) = msp.primary_span().as_ref() {
                 if primary_span.is_dummy() {
                     // FIXME(#59346): Not sure when this is the case and what
                     // should be done if it happens
@@ -203,7 +203,7 @@ impl AnnotateSnippetEmitterWriter {
                         Slice {
                             source,
                             line_start: *line_index,
-                            origin: Some(&file_name),
+                            origin: Some(file_name),
                             // FIXME(#59346): Not really sure when `fold` should be true or false
                             fold: false,
                             annotations: annotations

compiler/rustc_errors/src/emitter.rs

@@ -1297,7 +1297,7 @@ impl EmitterWriter {
                     buffer.append(line_number, line, style_or_override(*style, override_style));
                 }
             } else {
-                buffer.append(line_number, &text, style_or_override(*style, override_style));
+                buffer.append(line_number, text, style_or_override(*style, override_style));
             }
         }
     }
@@ -1931,7 +1931,7 @@ impl EmitterWriter {
                 self.draw_code_line(
                     &mut buffer,
                     &mut row_num,
-                    &highlight_parts,
+                    highlight_parts,
                     line_pos + line_start,
                     line,
                     show_code_change,
@@ -2338,7 +2338,7 @@ impl FileWithAnnotatedLines {
         let mut output = vec![];
         let mut multiline_annotations = vec![];
 
-        if let Some(ref sm) = emitter.source_map() {
+        if let Some(sm) = emitter.source_map() {
             for SpanLabel { span, is_primary, label } in msp.span_labels() {
                 // If we don't have a useful span, pick the primary span if that exists.
                 // Worst case we'll just print an error at the top of the main file.
@@ -2362,7 +2362,7 @@ impl FileWithAnnotatedLines {
 
                 let label = label.as_ref().map(|m| {
                     normalize_whitespace(
-                        &emitter.translate_message(m, &args).map_err(Report::new).unwrap(),
+                        &emitter.translate_message(m, args).map_err(Report::new).unwrap(),
                     )
                 });
 

compiler/rustc_expand/src/base.rs

@@ -777,7 +777,7 @@ impl SyntaxExtension {
         attrs: &[ast::Attribute],
     ) -> SyntaxExtension {
         let allow_internal_unstable =
-            attr::allow_internal_unstable(sess, &attrs).collect::<Vec<Symbol>>();
+            attr::allow_internal_unstable(sess, attrs).collect::<Vec<Symbol>>();
 
         let allow_internal_unsafe = attr::contains_name(attrs, sym::allow_internal_unsafe);
         let local_inner_macros = attr::find_by_name(attrs, sym::macro_export)
@@ -796,9 +796,9 @@ impl SyntaxExtension {
                 )
             })
             .unwrap_or_else(|| (None, helper_attrs));
-        let stability = attr::find_stability(&sess, attrs, span);
-        let const_stability = attr::find_const_stability(&sess, attrs, span);
-        let body_stability = attr::find_body_stability(&sess, attrs);
+        let stability = attr::find_stability(sess, attrs, span);
+        let const_stability = attr::find_const_stability(sess, attrs, span);
+        let body_stability = attr::find_body_stability(sess, attrs);
         if let Some((_, sp)) = const_stability {
             sess.emit_err(errors::MacroConstStability {
                 span: sp,
@@ -818,7 +818,7 @@ impl SyntaxExtension {
             allow_internal_unstable: (!allow_internal_unstable.is_empty())
                 .then(|| allow_internal_unstable.into()),
             stability: stability.map(|(s, _)| s),
-            deprecation: attr::find_deprecation(&sess, features, attrs).map(|(d, _)| d),
+            deprecation: attr::find_deprecation(sess, features, attrs).map(|(d, _)| d),
             helper_attrs,
             edition,
             builtin_name,
@@ -1464,7 +1464,7 @@ fn pretty_printing_compatibility_hack(item: &Item, sess: &ParseSess) -> bool {
 
                             if crate_matches {
                                 sess.buffer_lint_with_diagnostic(
-                                        &PROC_MACRO_BACK_COMPAT,
+                                        PROC_MACRO_BACK_COMPAT,
                                         item.ident.span,
                                         ast::CRATE_NODE_ID,
                                         "using an old version of `rental`",

compiler/rustc_expand/src/config.rs

@@ -434,9 +434,9 @@ impl<'a> StripUnconfigured<'a> {
             }
         };
         (
-            parse_cfg(&meta_item, &self.sess).map_or(true, |meta_item| {
+            parse_cfg(&meta_item, self.sess).map_or(true, |meta_item| {
                 attr::cfg_matches(
-                    &meta_item,
+                    meta_item,
                     &self.sess.parse_sess,
                     self.lint_node_id,
                     self.features,

compiler/rustc_expand/src/expand.rs

@@ -1096,7 +1096,7 @@ impl InvocationCollectorNode for P<ast::Item> {
             ModKind::Loaded(_, inline, _) => {
                 // Inline `mod foo { ... }`, but we still need to push directories.
                 let (dir_path, dir_ownership) = mod_dir_path(
-                    &ecx.sess,
+                    ecx.sess,
                     ident,
                     &attrs,
                     &ecx.current_expansion.module,
@@ -1111,7 +1111,7 @@ impl InvocationCollectorNode for P<ast::Item> {
                 let old_attrs_len = attrs.len();
                 let ParsedExternalMod { items, spans, file_path, dir_path, dir_ownership } =
                     parse_external_mod(
-                        &ecx.sess,
+                        ecx.sess,
                         ident,
                         span,
                         &ecx.current_expansion.module,
@@ -1168,14 +1168,14 @@ impl InvocationCollectorNode for P<ast::Item> {
                     ast::UseTreeKind::Simple(_) => idents.push(ut.ident()),
                     ast::UseTreeKind::Nested(nested) => {
                         for (ut, _) in nested {
-                            collect_use_tree_leaves(&ut, idents);
+                            collect_use_tree_leaves(ut, idents);
                         }
                     }
                 }
             }
 
             let mut idents = Vec::new();
-            collect_use_tree_leaves(&ut, &mut idents);
+            collect_use_tree_leaves(ut, &mut idents);
             return idents;
         }
 
@@ -1531,7 +1531,7 @@ impl InvocationCollectorNode for AstNodeWrapper<P<ast::Expr>, OptExprTag> {
         }
     }
     fn pre_flat_map_node_collect_attr(cfg: &StripUnconfigured<'_>, attr: &ast::Attribute) {
-        cfg.maybe_emit_expr_attr_err(&attr);
+        cfg.maybe_emit_expr_attr_err(attr);
     }
 }
 
@@ -1580,7 +1580,7 @@ struct InvocationCollector<'a, 'b> {
 impl<'a, 'b> InvocationCollector<'a, 'b> {
     fn cfg(&self) -> StripUnconfigured<'_> {
         StripUnconfigured {
-            sess: &self.cx.sess,
+            sess: self.cx.sess,
             features: Some(self.cx.ecfg.features),
             config_tokens: false,
             lint_node_id: self.cx.current_expansion.lint_node_id,
@@ -1693,7 +1693,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
             if attr.is_doc_comment() {
                 self.cx.sess.parse_sess.buffer_lint_with_diagnostic(
-                    &UNUSED_DOC_COMMENTS,
+                    UNUSED_DOC_COMMENTS,
                     current_span,
                     self.cx.current_expansion.lint_node_id,
                     "unused doc comment",
@@ -1705,7 +1705,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
                 // eagerly evaluated.
                 if attr_name != sym::cfg && attr_name != sym::cfg_attr {
                     self.cx.sess.parse_sess.buffer_lint_with_diagnostic(
-                        &UNUSED_ATTRIBUTES,
+                        UNUSED_ATTRIBUTES,
                         attr.span,
                         self.cx.current_expansion.lint_node_id,
                         format!("unused attribute `{attr_name}`"),

compiler/rustc_expand/src/mbe/macro_check.rs

@@ -650,6 +650,6 @@ fn buffer_lint(
 ) {
     // Macros loaded from other crates have dummy node ids.
     if node_id != DUMMY_NODE_ID {
-        sess.buffer_lint(&META_VARIABLE_MISUSE, span, node_id, message);
+        sess.buffer_lint(META_VARIABLE_MISUSE, span, node_id, message);
     }
 }

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -483,7 +483,7 @@ impl TtParser {
                     if matches!(t, Token { kind: DocComment(..), .. }) {
                         mp.idx += 1;
                         self.cur_mps.push(mp);
-                    } else if token_name_eq(&t, token) {
+                    } else if token_name_eq(t, token) {
                         mp.idx += 1;
                         self.next_mps.push(mp);
                     }

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -213,7 +213,7 @@ fn expand_macro<'cx>(
             let arm_span = rhses[i].span();
 
             // rhs has holes ( `$id` and `$(...)` that need filled)
-            let mut tts = match transcribe(cx, &named_matches, &rhs, rhs_span, transparency) {
+            let mut tts = match transcribe(cx, &named_matches, rhs, rhs_span, transparency) {
                 Ok(tts) => tts,
                 Err(mut err) => {
                     err.emit();
@@ -511,7 +511,7 @@ pub fn compile_declarative_macro(
                     )
                     .pop()
                     .unwrap();
-                    valid &= check_lhs_nt_follows(&sess.parse_sess, &def, &tt);
+                    valid &= check_lhs_nt_follows(&sess.parse_sess, def, &tt);
                     return tt;
                 }
                 sess.parse_sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
@@ -927,7 +927,7 @@ impl<'tt> TtHandle<'tt> {
     fn get(&'tt self) -> &'tt mbe::TokenTree {
         match self {
             TtHandle::TtRef(tt) => tt,
-            TtHandle::Token(token_tt) => &token_tt,
+            TtHandle::Token(token_tt) => token_tt,
         }
     }
 }
@@ -1170,7 +1170,7 @@ fn check_matcher_core<'tt>(
                             Some(NonterminalKind::PatParam { inferred: false }),
                         ));
                         sess.buffer_lint_with_diagnostic(
-                            &RUST_2021_INCOMPATIBLE_OR_PATTERNS,
+                            RUST_2021_INCOMPATIBLE_OR_PATTERNS,
                             span,
                             ast::CRATE_NODE_ID,
                             "the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro",
@@ -1407,7 +1407,7 @@ fn is_in_follow(tok: &mbe::TokenTree, kind: NonterminalKind) -> IsInFollow {
 
 fn quoted_tt_to_string(tt: &mbe::TokenTree) -> String {
     match tt {
-        mbe::TokenTree::Token(token) => pprust::token_to_string(&token).into(),
+        mbe::TokenTree::Token(token) => pprust::token_to_string(token).into(),
         mbe::TokenTree::MetaVar(_, name) => format!("${name}"),
         mbe::TokenTree::MetaVarDecl(_, name, Some(kind)) => format!("${name}:{kind}"),
         mbe::TokenTree::MetaVarDecl(_, name, None) => format!("${name}:"),

compiler/rustc_expand/src/mbe/quoted.rs

@@ -116,7 +116,7 @@ pub(super) fn parse(
 fn maybe_emit_macro_metavar_expr_feature(features: &Features, sess: &ParseSess, span: Span) {
     if !features.macro_metavar_expr {
         let msg = "meta-variable expressions are unstable";
-        feature_err(&sess, sym::macro_metavar_expr, span, msg).emit();
+        feature_err(sess, sym::macro_metavar_expr, span, msg).emit();
     }
 }
 
@@ -174,7 +174,7 @@ fn parse_tree<'a>(
                                 // The delimiter is `{`. This indicates the beginning
                                 // of a meta-variable expression (e.g. `${count(ident)}`).
                                 // Try to parse the meta-variable expression.
-                                match MetaVarExpr::parse(&tts, delim_span.entire(), sess) {
+                                match MetaVarExpr::parse(tts, delim_span.entire(), sess) {
                                     Err(mut err) => {
                                         err.emit();
                                         // Returns early the same read `$` to avoid spanning
@@ -242,10 +242,8 @@ fn parse_tree<'a>(
 
                 // `tree` is followed by some other token. This is an error.
                 Some(tokenstream::TokenTree::Token(token, _)) => {
-                    let msg = format!(
-                        "expected identifier, found `{}`",
-                        pprust::token_to_string(&token),
-                    );
+                    let msg =
+                        format!("expected identifier, found `{}`", pprust::token_to_string(token),);
                     sess.span_diagnostic.span_err(token.span, msg);
                     TokenTree::MetaVar(token.span, Ident::empty())
                 }
@@ -291,7 +289,7 @@ fn parse_kleene_op<'a>(
     span: Span,
 ) -> Result<Result<(KleeneOp, Span), Token>, Span> {
     match input.next() {
-        Some(tokenstream::TokenTree::Token(token, _)) => match kleene_op(&token) {
+        Some(tokenstream::TokenTree::Token(token, _)) => match kleene_op(token) {
             Some(op) => Ok(Ok((op, token.span))),
             None => Ok(Err(token.clone())),
         },

compiler/rustc_expand/src/mbe/transcribe.rs

@@ -90,7 +90,7 @@ pub(super) fn transcribe<'a>(
 
     // We descend into the RHS (`src`), expanding things as we go. This stack contains the things
     // we have yet to expand/are still expanding. We start the stack off with the whole RHS.
-    let mut stack: SmallVec<[Frame<'_>; 1]> = smallvec![Frame::new(&src, src_span)];
+    let mut stack: SmallVec<[Frame<'_>; 1]> = smallvec![Frame::new(src, src_span)];
 
     // As we descend in the RHS, we will need to be able to match nested sequences of matchers.
     // `repeats` keeps track of where we are in matching at each level, with the last element being
@@ -166,7 +166,7 @@ pub(super) fn transcribe<'a>(
             // and the matches in `interp` have the same shape. Otherwise, either the caller or the
             // macro writer has made a mistake.
             seq @ mbe::TokenTree::Sequence(_, delimited) => {
-                match lockstep_iter_size(&seq, interp, &repeats) {
+                match lockstep_iter_size(seq, interp, &repeats) {
                     LockstepIterSize::Unconstrained => {
                         return Err(cx.create_err(NoSyntaxVarsExprRepeat { span: seq.span() }));
                     }
@@ -250,7 +250,7 @@ pub(super) fn transcribe<'a>(
 
             // Replace meta-variable expressions with the result of their expansion.
             mbe::TokenTree::MetaVarExpr(sp, expr) => {
-                transcribe_metavar_expr(cx, expr, interp, &mut marker, &repeats, &mut result, &sp)?;
+                transcribe_metavar_expr(cx, expr, interp, &mut marker, &repeats, &mut result, sp)?;
             }
 
             // If we are entering a new delimiter, we push its contents to the `stack` to be
@@ -529,7 +529,7 @@ fn transcribe_metavar_expr<'a>(
     match *expr {
         MetaVarExpr::Count(original_ident, depth_opt) => {
             let matched = matched_from_ident(cx, original_ident, interp)?;
-            let count = count_repetitions(cx, depth_opt, matched, &repeats, sp)?;
+            let count = count_repetitions(cx, depth_opt, matched, repeats, sp)?;
             let tt = TokenTree::token_alone(
                 TokenKind::lit(token::Integer, sym::integer(count), None),
                 visited_span(),

compiler/rustc_expand/src/module.rs

@@ -57,7 +57,7 @@ pub(crate) fn parse_external_mod(
     // We bail on the first error, but that error does not cause a fatal error... (1)
     let result: Result<_, ModError<'_>> = try {
         // Extract the file path and the new ownership.
-        let mp = mod_file_path(sess, ident, &attrs, &module.dir_path, dir_ownership)?;
+        let mp = mod_file_path(sess, ident, attrs, &module.dir_path, dir_ownership)?;
         dir_ownership = mp.dir_ownership;
 
         // Ensure file paths are acyclic.
@@ -119,7 +119,7 @@ pub(crate) fn mod_dir_path(
         Inline::No => {
             // FIXME: This is a subset of `parse_external_mod` without actual parsing,
             // check whether the logic for unloaded, loaded and inline modules can be unified.
-            let file_path = mod_file_path(sess, ident, &attrs, &module.dir_path, dir_ownership)
+            let file_path = mod_file_path(sess, ident, attrs, &module.dir_path, dir_ownership)
                 .map(|mp| {
                     dir_ownership = mp.dir_ownership;
                     mp.file_path

compiler/rustc_expand/src/proc_macro_server.rs

@@ -784,6 +784,6 @@ impl server::Server for Rustc<'_, '_> {
     }
 
     fn with_symbol_string(symbol: &Self::Symbol, f: impl FnOnce(&str)) {
-        f(&symbol.as_str())
+        f(symbol.as_str())
     }
 }

compiler/rustc_hir_analysis/src/astconv/errors.rs

@@ -227,7 +227,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                         self.tcx(),
                         generics,
                         &mut err,
-                        &ty_param_name,
+                        ty_param_name,
                         &trait_name,
                         None,
                         None,

compiler/rustc_hir_analysis/src/astconv/lint.rs

@@ -106,7 +106,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     );
                 }
                 // check if the impl trait that we are considering is a impl of a local trait
-                self.maybe_lint_blanket_trait_impl(&self_ty, &mut diag);
+                self.maybe_lint_blanket_trait_impl(self_ty, &mut diag);
                 diag.stash(self_ty.span, StashKey::TraitMissingMethod);
             } else {
                 let msg = "trait objects without an explicit `dyn` are deprecated";
@@ -121,7 +121,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                             sugg,
                             Applicability::MachineApplicable,
                         );
-                        self.maybe_lint_blanket_trait_impl(&self_ty, lint);
+                        self.maybe_lint_blanket_trait_impl(self_ty, lint);
                         lint
                     },
                 );