Rollup of 8 pull requests

compiler/rustc_ast_lowering/src/item.rs

@@ -1,6 +1,6 @@
 use super::errors::{InvalidAbi, InvalidAbiSuggestion, MisplacedRelaxTraitBound};
 use super::ResolverAstLoweringExt;
-use super::{Arena, AstOwner, ImplTraitContext, ImplTraitPosition};
+use super::{AstOwner, ImplTraitContext, ImplTraitPosition};
 use super::{FnDeclKind, LoweringContext, ParamMode};
 
 use rustc_ast::ptr::P;
@@ -24,7 +24,6 @@ use thin_vec::ThinVec;
 pub(super) struct ItemLowerer<'a, 'hir> {
     pub(super) tcx: TyCtxt<'hir>,
     pub(super) resolver: &'a mut ResolverAstLowering,
-    pub(super) ast_arena: &'a Arena<'static>,
     pub(super) ast_index: &'a IndexVec<LocalDefId, AstOwner<'a>>,
     pub(super) owners: &'a mut IndexVec<LocalDefId, hir::MaybeOwner<&'hir hir::OwnerInfo<'hir>>>,
 }
@@ -60,7 +59,6 @@ impl<'a, 'hir> ItemLowerer<'a, 'hir> {
             tcx: self.tcx,
             resolver: self.resolver,
             arena: self.tcx.hir_arena,
-            ast_arena: self.ast_arena,
 
             // HirId handling.
             bodies: Vec::new(),

compiler/rustc_ast_lowering/src/lib.rs

@@ -42,7 +42,6 @@ extern crate tracing;
 
 use crate::errors::{AssocTyParentheses, AssocTyParenthesesSub, MisplacedImplTrait, TraitFnAsync};
 
-use rustc_arena::declare_arena;
 use rustc_ast::ptr::P;
 use rustc_ast::visit;
 use rustc_ast::{self as ast, *};
@@ -94,13 +93,6 @@ struct LoweringContext<'a, 'hir> {
     /// Used to allocate HIR nodes.
     arena: &'hir hir::Arena<'hir>,
 
-    /// Used to allocate temporary AST nodes for use during lowering.
-    /// This allows us to create "fake" AST -- these nodes can sometimes
-    /// be allocated on the stack, but other times we need them to live longer
-    /// than the current stack frame, so they can be collected into vectors
-    /// and things like that.
-    ast_arena: &'a Arena<'static>,
-
     /// Bodies inside the owner being lowered.
     bodies: Vec<(hir::ItemLocalId, &'hir hir::Body<'hir>)>,
     /// Attributes inside the owner being lowered.
@@ -146,15 +138,6 @@ struct LoweringContext<'a, 'hir> {
     generics_def_id_map: Vec<FxHashMap<LocalDefId, LocalDefId>>,
 }
 
-declare_arena!([
-    [] tys: rustc_ast::Ty,
-    [] aba: rustc_ast::AngleBracketedArgs,
-    [] ptr: rustc_ast::PolyTraitRef,
-    // This _marker field is needed because `declare_arena` creates `Arena<'tcx>` and we need to
-    // use `'tcx`. If we don't have this we get a compile error.
-    [] _marker: std::marker::PhantomData<&'tcx ()>,
-]);
-
 trait ResolverAstLoweringExt {
     fn legacy_const_generic_args(&self, expr: &Expr) -> Option<Vec<usize>>;
     fn get_partial_res(&self, id: NodeId) -> Option<PartialRes>;
@@ -442,13 +425,10 @@ pub fn lower_to_hir<'hir>(tcx: TyCtxt<'hir>, (): ()) -> hir::Crate<'hir> {
         tcx.definitions_untracked().def_index_count(),
     );
 
-    let ast_arena = Arena::default();
-
     for def_id in ast_index.indices() {
         item::ItemLowerer {
             tcx,
             resolver: &mut resolver,
-            ast_arena: &ast_arena,
             ast_index: &ast_index,
             owners: &mut owners,
         }
@@ -1001,8 +981,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 }
                 GenericArgs::Parenthesized(data) => {
                     self.emit_bad_parenthesized_trait_in_assoc_ty(data);
-                    let aba = self.ast_arena.aba.alloc(data.as_angle_bracketed_args());
-                    self.lower_angle_bracketed_parameter_data(aba, ParamMode::Explicit, itctx).0
+                    self.lower_angle_bracketed_parameter_data(
+                        &data.as_angle_bracketed_args(),
+                        ParamMode::Explicit,
+                        itctx,
+                    )
+                    .0
                 }
             };
             gen_args_ctor.into_generic_args(self)
@@ -1067,13 +1051,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
                     self.with_dyn_type_scope(false, |this| {
                         let node_id = this.next_node_id();
-                        let ty = this.ast_arena.tys.alloc(Ty {
-                            id: node_id,
-                            kind: TyKind::ImplTrait(impl_trait_node_id, bounds.clone()),
-                            span: this.lower_span(constraint.span),
-                            tokens: None,
-                        });
-                        let ty = this.lower_ty(ty, itctx);
+                        let ty = this.lower_ty(
+                            &Ty {
+                                id: node_id,
+                                kind: TyKind::ImplTrait(impl_trait_node_id, bounds.clone()),
+                                span: this.lower_span(constraint.span),
+                                tokens: None,
+                            },
+                            itctx,
+                        );
 
                         hir::TypeBindingKind::Equality { term: ty.into() }
                     })
@@ -1217,13 +1203,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
             && let Some(Res::Def(DefKind::Trait | DefKind::TraitAlias, _)) = partial_res.full_res()
         {
             let (bounds, lifetime_bound) = self.with_dyn_type_scope(true, |this| {
-                let poly_trait_ref = this.ast_arena.ptr.alloc(PolyTraitRef {
-                    bound_generic_params: vec![],
-                    trait_ref: TraitRef { path: path.clone(), ref_id: t.id },
-                    span: t.span
-                });
                 let bound = this.lower_poly_trait_ref(
-                    poly_trait_ref,
+                    &PolyTraitRef {
+                        bound_generic_params: vec![],
+                        trait_ref: TraitRef { path: path.clone(), ref_id: t.id },
+                        span: t.span
+                    },
                     itctx,
                 );
                 let bounds = this.arena.alloc_from_iter([bound]);

compiler/rustc_borrowck/src/constraints/graph.rs

@@ -148,7 +148,7 @@ impl<'s, 'tcx, D: ConstraintGraphDirecton> Iterator for Edges<'s, 'tcx, D> {
         if let Some(p) = self.pointer {
             self.pointer = self.graph.next_constraints[p];
 
-            Some(self.constraints[p].clone())
+            Some(self.constraints[p])
         } else if let Some(next_static_idx) = self.next_static_idx {
             self.next_static_idx = if next_static_idx == (self.graph.first_constraints.len() - 1) {
                 None

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -649,7 +649,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         if !assign_value.is_empty() {
             err.span_suggestion_verbose(
                 sugg_span.shrink_to_hi(),
-                format!("consider assigning a value"),
+                "consider assigning a value",
                 format!(" = {}", assign_value),
                 Applicability::MaybeIncorrect,
             );

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -270,7 +270,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                 for extra in extra_info {
                     match extra {
                         ExtraConstraintInfo::PlaceholderFromPredicate(span) => {
-                            err.span_note(*span, format!("due to current limitations in the borrow checker, this implies a `'static` lifetime"));
+                            err.span_note(*span, "due to current limitations in the borrow checker, this implies a `'static` lifetime");
                         }
                     }
                 }

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -472,7 +472,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         for extra in extra_info {
             match extra {
                 ExtraConstraintInfo::PlaceholderFromPredicate(span) => {
-                    diag.span_note(span, format!("due to current limitations in the borrow checker, this implies a `'static` lifetime"));
+                    diag.span_note(span, "due to current limitations in the borrow checker, this implies a `'static` lifetime");
                 }
             }
         }

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -831,7 +831,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             if self.eval_verify_bound(
                 infcx,
                 param_env,
-                body,
                 generic_ty,
                 type_test.lower_bound,
                 &type_test.verify_bound,
@@ -962,14 +961,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             // where `ur` is a local bound -- we are sometimes in a
             // position to prove things that our caller cannot.  See
             // #53570 for an example.
-            if self.eval_verify_bound(
-                infcx,
-                param_env,
-                body,
-                generic_ty,
-                ur,
-                &type_test.verify_bound,
-            ) {
+            if self.eval_verify_bound(infcx, param_env, generic_ty, ur, &type_test.verify_bound) {
                 continue;
             }
 
@@ -1190,7 +1182,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         &self,
         infcx: &InferCtxt<'tcx>,
         param_env: ty::ParamEnv<'tcx>,
-        body: &Body<'tcx>,
         generic_ty: Ty<'tcx>,
         lower_bound: RegionVid,
         verify_bound: &VerifyBound<'tcx>,
@@ -1213,25 +1204,11 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             }
 
             VerifyBound::AnyBound(verify_bounds) => verify_bounds.iter().any(|verify_bound| {
-                self.eval_verify_bound(
-                    infcx,
-                    param_env,
-                    body,
-                    generic_ty,
-                    lower_bound,
-                    verify_bound,
-                )
+                self.eval_verify_bound(infcx, param_env, generic_ty, lower_bound, verify_bound)
             }),
 
             VerifyBound::AllBounds(verify_bounds) => verify_bounds.iter().all(|verify_bound| {
-                self.eval_verify_bound(
-                    infcx,
-                    param_env,
-                    body,
-                    generic_ty,
-                    lower_bound,
-                    verify_bound,
-                )
+                self.eval_verify_bound(infcx, param_env, generic_ty, lower_bound, verify_bound)
             }),
         }
     }

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -612,7 +612,7 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
 
         let locations = location.to_locations();
         for constraint in constraints.outlives().iter() {
-            let mut constraint = constraint.clone();
+            let mut constraint = *constraint;
             constraint.locations = locations;
             if let ConstraintCategory::Return(_)
             | ConstraintCategory::UseAsConst

compiler/rustc_codegen_llvm/src/asm.rs

@@ -144,7 +144,7 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
                     // We prefer the latter because it matches the behavior of
                     // Clang.
                     if late && matches!(reg, InlineAsmRegOrRegClass::Reg(_)) {
-                        constraints.push(format!("{}", reg_to_llvm(reg, Some(&in_value.layout))));
+                        constraints.push(reg_to_llvm(reg, Some(&in_value.layout)).to_string());
                     } else {
                         constraints.push(format!("{}", op_idx[&idx]));
                     }

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -2240,7 +2240,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     ),
                     "s",
                 ),
-                [only] => (format!("{only}"), ""),
+                [only] => (only.to_string(), ""),
                 [] => unreachable!(),
             };
             let last_span = *arg_spans.last().unwrap();

compiler/rustc_hir_analysis/src/check/check.rs

@@ -99,18 +99,17 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
             ty: Ty<'tcx>,
             tcx: TyCtxt<'tcx>,
             param_env: ty::ParamEnv<'tcx>,
-            span: Span,
         ) -> bool {
             // We don't just accept all !needs_drop fields, due to semver concerns.
             match ty.kind() {
                 ty::Ref(..) => true, // references never drop (even mutable refs, which are non-Copy and hence fail the later check)
                 ty::Tuple(tys) => {
                     // allow tuples of allowed types
-                    tys.iter().all(|ty| allowed_union_field(ty, tcx, param_env, span))
+                    tys.iter().all(|ty| allowed_union_field(ty, tcx, param_env))
                 }
                 ty::Array(elem, _len) => {
                     // Like `Copy`, we do *not* special-case length 0.
-                    allowed_union_field(*elem, tcx, param_env, span)
+                    allowed_union_field(*elem, tcx, param_env)
                 }
                 _ => {
                     // Fallback case: allow `ManuallyDrop` and things that are `Copy`.
@@ -124,7 +123,7 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
         for field in &def.non_enum_variant().fields {
             let field_ty = field.ty(tcx, substs);
 
-            if !allowed_union_field(field_ty, tcx, param_env, span) {
+            if !allowed_union_field(field_ty, tcx, param_env) {
                 let (field_span, ty_span) = match tcx.hir().get_if_local(field.did) {
                     // We are currently checking the type this field came from, so it must be local.
                     Some(Node::Field(field)) => (field.span, field.ty.span),

compiler/rustc_hir_typeck/src/coercion.rs

@@ -1548,7 +1548,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                             cause,
                             expected,
                             found,
-                            coercion_error.clone(),
+                            coercion_error,
                             fcx,
                             parent_id,
                             expression,
@@ -1567,7 +1567,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                             cause,
                             expected,
                             found,
-                            coercion_error.clone(),
+                            coercion_error,
                             fcx,
                             id,
                             expression,
@@ -1583,7 +1583,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                             cause,
                             expected,
                             found,
-                            coercion_error.clone(),
+                            coercion_error,
                         );
                     }
                 }

compiler/rustc_hir_typeck/src/demand.rs

@@ -163,7 +163,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let expr = expr.peel_drop_temps();
         let cause = self.misc(expr.span);
         let expr_ty = self.resolve_vars_with_obligations(checked_ty);
-        let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e.clone());
+        let mut err = self.err_ctxt().report_mismatched_types(&cause, expected, expr_ty, e);
 
         let is_insufficiently_polymorphic =
             matches!(e, TypeError::RegionsInsufficientlyPolymorphic(..));
@@ -406,7 +406,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
 
                     let note_about_variant_field_privacy = (field_is_local && !field_is_accessible)
-                        .then(|| format!(" (its field is private, but it's local to this crate and its privacy can be changed)"));
+                        .then(|| " (its field is private, but it's local to this crate and its privacy can be changed)".to_string());
 
                     let sole_field_ty = sole_field.ty(self.tcx, substs);
                     if self.can_coerce(expr_ty, sole_field_ty) {

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -28,7 +28,7 @@ use rustc_middle::ty::adjustment::AllowTwoPhase;
 use rustc_middle::ty::visit::TypeVisitable;
 use rustc_middle::ty::{self, DefIdTree, IsSuggestable, Ty, TypeSuperVisitable, TypeVisitor};
 use rustc_session::Session;
-use rustc_span::symbol::Ident;
+use rustc_span::symbol::{kw, Ident};
 use rustc_span::{self, sym, Span};
 use rustc_trait_selection::traits::{self, ObligationCauseCode, SelectionContext};
 
@@ -1013,7 +1013,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             } else {
                                 args_span
                             };
-                            labels.push((span, format!("multiple arguments are missing")));
+                            labels.push((span, "multiple arguments are missing".to_string()));
                             suggestion_text = match suggestion_text {
                                 SuggestionText::None | SuggestionText::Provide(_) => {
                                     SuggestionText::Provide(true)
@@ -1141,6 +1141,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         "()".to_string()
                     } else if expected_ty.is_suggestable(tcx, false) {
                         format!("/* {} */", expected_ty)
+                    } else if let Some(fn_def_id) = fn_def_id
+                        && self.tcx.def_kind(fn_def_id).is_fn_like()
+                        && let self_implicit = matches!(call_expr.kind, hir::ExprKind::MethodCall(..)) as usize
+                        && let Some(arg) = self.tcx.fn_arg_names(fn_def_id).get(expected_idx.as_usize() + self_implicit)
+                        && arg.name != kw::SelfLower
+                    {
+                        format!("/* {} */", arg.name)
                     } else {
                         "/* value */".to_string()
                     }

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -319,11 +319,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             }
 
-            err.multipart_suggestion_verbose(
-                format!("use parentheses to call these"),
-                sugg,
-                applicability,
-            );
+            err.multipart_suggestion_verbose("use parentheses to call these", sugg, applicability);
 
             true
         } else {

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -1007,7 +1007,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         if def_kind == DefKind::AssocFn && lev_candidate.fn_has_self_parameter {
                             err.span_suggestion(
                                 span,
-                                &format!("there is a method with a similar name",),
+                                "there is a method with a similar name",
                                 lev_candidate.name,
                                 Applicability::MaybeIncorrect,
                             );