Auto merge of #110405 - fee1-dead-contrib:rollup-9rkree6, r=fee1-dead

Rollup of 4 pull requests

Successful merges:

 - #110397 (Move some utils out of `rustc_const_eval`)
 - #110398 (use matches! macro in more places)
 - #110400 (more clippy fixes: clippy::{iter_cloned_collect, unwarp_or_else_defau…)
 - #110402 (Remove the loop in `Align::from_bytes`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

33 files changed, 91 insertions, 114 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 094eb6fa67e..dee613226a8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4421,7 +4421,6 @@ dependencies = [
  "either",
  "itertools",
  "polonius-engine",
- "rustc_const_eval",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_graphviz",
diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs
index b0c0ee942ea..7a3defd2a5d 100644
--- a/compiler/rustc_abi/src/lib.rs
+++ b/compiler/rustc_abi/src/lib.rs
@@ -665,15 +665,12 @@ impl Align {
             format!("`{}` is too large", align)
         }
 
-        let mut bytes = align;
-        let mut pow2: u8 = 0;
-        while (bytes & 1) == 0 {
-            pow2 += 1;
-            bytes >>= 1;
-        }
-        if bytes != 1 {
+        let tz = align.trailing_zeros();
+        if align != (1 << tz) {
             return Err(not_power_of_2(align));
         }
+
+        let pow2 = tz as u8;
         if pow2 > Self::MAX.pow2 {
             return Err(too_large(align));
         }
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index df1a716755b..ab0409efb3b 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -1298,17 +1298,17 @@ impl Expr {
 
     /// To a first-order approximation, is this a pattern?
     pub fn is_approximately_pattern(&self) -> bool {
-        match &self.peel_parens().kind {
+        matches!(
+            &self.peel_parens().kind,
             ExprKind::Array(_)
-            | ExprKind::Call(_, _)
-            | ExprKind::Tup(_)
-            | ExprKind::Lit(_)
-            | ExprKind::Range(_, _, _)
-            | ExprKind::Underscore
-            | ExprKind::Path(_, _)
-            | ExprKind::Struct(_) => true,
-            _ => false,
-        }
+                | ExprKind::Call(_, _)
+                | ExprKind::Tup(_)
+                | ExprKind::Lit(_)
+                | ExprKind::Range(_, _, _)
+                | ExprKind::Underscore
+                | ExprKind::Path(_, _)
+                | ExprKind::Struct(_)
+        )
     }
 }
 
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index f7ae96b7c4a..2af47e11637 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -332,10 +332,7 @@ enum FnDeclKind {
 
 impl FnDeclKind {
     fn param_impl_trait_allowed(&self) -> bool {
-        match self {
-            FnDeclKind::Fn | FnDeclKind::Inherent | FnDeclKind::Impl | FnDeclKind::Trait => true,
-            _ => false,
-        }
+        matches!(self, FnDeclKind::Fn | FnDeclKind::Inherent | FnDeclKind::Impl | FnDeclKind::Trait)
     }
 
     fn return_impl_trait_allowed(&self, tcx: TyCtxt<'_>) -> bool {
diff --git a/compiler/rustc_borrowck/Cargo.toml b/compiler/rustc_borrowck/Cargo.toml
index 87c113f3e30..e0bb87336e5 100644
--- a/compiler/rustc_borrowck/Cargo.toml
+++ b/compiler/rustc_borrowck/Cargo.toml
@@ -20,7 +20,6 @@ rustc_infer = { path = "../rustc_infer" }
 rustc_lexer = { path = "../rustc_lexer" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
-rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_mir_dataflow = { path = "../rustc_mir_dataflow" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 75a3dd0c0f3..6259ae47e89 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -1,5 +1,4 @@
 use either::Either;
-use rustc_const_eval::util::CallKind;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::{
@@ -18,6 +17,7 @@ use rustc_middle::mir::{
     ProjectionElem, Rvalue, Statement, StatementKind, Terminator, TerminatorKind, VarBindingForm,
 };
 use rustc_middle::ty::{self, suggest_constraining_type_params, PredicateKind, Ty};
+use rustc_middle::util::CallKind;
 use rustc_mir_dataflow::move_paths::{InitKind, MoveOutIndex, MovePathIndex};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::hygiene::DesugaringKind;
@@ -2424,7 +2424,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             Some((method_did, method_substs)),
         ) = (
             &self.body[loan.reserve_location.block].terminator,
-            rustc_const_eval::util::find_self_call(
+            rustc_middle::util::find_self_call(
                 tcx,
                 self.body,
                 loan.assigned_place.local,
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index 110354a20d8..dd003b5b040 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -1,7 +1,6 @@
 //! Borrow checker diagnostics.
 
 use itertools::Itertools;
-use rustc_const_eval::util::{call_kind, CallDesugaringKind};
 use rustc_errors::{Applicability, Diagnostic};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, Namespace};
@@ -15,6 +14,7 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
+use rustc_middle::util::{call_kind, CallDesugaringKind};
 use rustc_mir_dataflow::move_paths::{InitLocation, LookupResult};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::{symbol::sym, Span, Symbol, DUMMY_SP};
@@ -45,7 +45,7 @@ pub(crate) use mutability_errors::AccessKind;
 pub(crate) use outlives_suggestion::OutlivesSuggestionBuilder;
 pub(crate) use region_errors::{ErrorConstraintInfo, RegionErrorKind, RegionErrors};
 pub(crate) use region_name::{RegionName, RegionNameSource};
-pub(crate) use rustc_const_eval::util::CallKind;
+pub(crate) use rustc_middle::util::CallKind;
 
 pub(super) struct DescribePlaceOpt {
     pub including_downcast: bool,
@@ -874,7 +874,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         }) = &self.body[location.block].terminator
         {
             let Some((method_did, method_substs)) =
-                rustc_const_eval::util::find_self_call(
+            rustc_middle::util::find_self_call(
                     self.infcx.tcx,
                     &self.body,
                     target_temp,
diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
index 9d904009650..9c907147e5a 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -15,8 +15,8 @@ use rustc_span::{sym, BytePos, Span};
 use rustc_target::abi::FieldIdx;
 
 use crate::diagnostics::BorrowedContentSource;
+use crate::util::FindAssignments;
 use crate::MirBorrowckCtxt;
-use rustc_const_eval::util::collect_writes::FindAssignments;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub(crate) enum AccessKind {
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs
index 70d0a101b4e..fdd82c7e3b2 100644
--- a/compiler/rustc_borrowck/src/lib.rs
+++ b/compiler/rustc_borrowck/src/lib.rs
@@ -88,6 +88,7 @@ mod session_diagnostics;
 mod type_check;
 mod universal_regions;
 mod used_muts;
+mod util;
 
 /// A public API provided for the Rust compiler consumers.
 pub mod consumers;
diff --git a/compiler/rustc_const_eval/src/util/collect_writes.rs b/compiler/rustc_borrowck/src/util/collect_writes.rs
index 8d92bb35938..8d92bb35938 100644
--- a/compiler/rustc_const_eval/src/util/collect_writes.rs
+++ b/compiler/rustc_borrowck/src/util/collect_writes.rs
diff --git a/compiler/rustc_borrowck/src/util/mod.rs b/compiler/rustc_borrowck/src/util/mod.rs
new file mode 100644
index 00000000000..7377d4de727
--- /dev/null
+++ b/compiler/rustc_borrowck/src/util/mod.rs
@@ -0,0 +1,3 @@
+mod collect_writes;
+
+pub use collect_writes::FindAssignments;
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/ops.rs b/compiler/rustc_const_eval/src/transform/check_consts/ops.rs
index c0f5b3725b3..4fe842856aa 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/ops.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/ops.rs
@@ -14,6 +14,7 @@ use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::{suggest_constraining_type_param, Adt, Closure, FnDef, FnPtr, Param, Ty};
 use rustc_middle::ty::{Binder, TraitRef};
+use rustc_middle::util::{call_kind, CallDesugaringKind, CallKind};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
 use rustc_span::{BytePos, Pos, Span, Symbol};
@@ -21,7 +22,6 @@ use rustc_trait_selection::traits::SelectionContext;
 
 use super::ConstCx;
 use crate::errors;
-use crate::util::{call_kind, CallDesugaringKind, CallKind};
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum Status {
diff --git a/compiler/rustc_const_eval/src/util/mod.rs b/compiler/rustc_const_eval/src/util/mod.rs
index c0aabd77cee..7641f560714 100644
--- a/compiler/rustc_const_eval/src/util/mod.rs
+++ b/compiler/rustc_const_eval/src/util/mod.rs
@@ -1,14 +1,9 @@
 mod alignment;
-mod call_kind;
 mod check_validity_requirement;
-pub mod collect_writes;
 mod compare_types;
-mod find_self_call;
 mod type_name;
 
 pub use self::alignment::is_disaligned;
-pub use self::call_kind::{call_kind, CallDesugaringKind, CallKind};
 pub use self::check_validity_requirement::check_validity_requirement;
 pub use self::compare_types::{is_equal_up_to_subtyping, is_subtype};
-pub use self::find_self_call::find_self_call;
 pub use self::type_name::type_name;
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index 8c58129c800..30bf8c2ad10 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -234,10 +234,7 @@ impl DefKind {
 
     #[inline]
     pub fn is_fn_like(self) -> bool {
-        match self {
-            DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Generator => true,
-            _ => false,
-        }
+        matches!(self, DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Generator)
     }
 
     /// Whether `query get_codegen_attrs` should be used with this definition.
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index 5d119a7737a..863a9977446 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -1317,7 +1317,7 @@ fn compare_number_of_generics<'tcx>(
                         impl_count,
                         kind,
                         pluralize!(impl_count),
-                        suffix.unwrap_or_else(String::new),
+                        suffix.unwrap_or_default(),
                     ),
                 );
             }
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index cbbaf8f857d..7c07a1ebaec 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -1457,10 +1457,7 @@ fn compute_sig_of_foreign_fn_decl<'tcx>(
 }
 
 fn is_foreign_item(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
-    match tcx.hir().get_by_def_id(def_id) {
-        Node::ForeignItem(..) => true,
-        _ => false,
-    }
+    matches!(tcx.hir().get_by_def_id(def_id), Node::ForeignItem(..))
 }
 
 fn generator_kind(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<hir::GeneratorKind> {
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 6ffa0134f3d..ffc73d64fc0 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -1735,10 +1735,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             } else {
                 self.check_expr_has_type_or_error(base_expr, adt_ty, |_| {
                     let base_ty = self.typeck_results.borrow().expr_ty(*base_expr);
-                    let same_adt = match (adt_ty.kind(), base_ty.kind()) {
-                        (ty::Adt(adt, _), ty::Adt(base_adt, _)) if adt == base_adt => true,
-                        _ => false,
-                    };
+                    let same_adt = matches!((adt_ty.kind(), base_ty.kind()),
+                        (ty::Adt(adt, _), ty::Adt(base_adt, _)) if adt == base_adt);
                     if self.tcx.sess.is_nightly_build() && same_adt {
                         feature_err(
                             &self.tcx.sess.parse_sess,
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
index 22c1e387117..27c3b796d14 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -312,13 +312,10 @@ pub fn suggest_new_region_bound(
                             Applicability::MaybeIncorrect,
                         );
                     }
-                } else if opaque.bounds.iter().any(|arg| match arg {
-                    GenericBound::Outlives(Lifetime { ident, .. })
-                        if ident.name.to_string() == lifetime_name =>
-                    {
-                        true
-                    }
-                    _ => false,
+                } else if opaque.bounds.iter().any(|arg| {
+                    matches!(arg,
+                        GenericBound::Outlives(Lifetime { ident, .. })
+                        if ident.name.to_string() == lifetime_name )
                 }) {
                 } else {
                     // get a lifetime name of existing named lifetimes if any
diff --git a/compiler/rustc_infer/src/infer/mod.rs b/compiler/rustc_infer/src/infer/mod.rs
index 66f51328bbe..f263a0773e4 100644
--- a/compiler/rustc_infer/src/infer/mod.rs
+++ b/compiler/rustc_infer/src/infer/mod.rs
@@ -1577,10 +1577,10 @@ impl<'tcx> InferCtxt<'tcx> {
             (TyOrConstInferVar::Ty(ty_var), Ok(inner)) => {
                 use self::type_variable::TypeVariableValue;
 
-                match inner.try_type_variables_probe_ref(ty_var) {
-                    Some(TypeVariableValue::Unknown { .. }) => true,
-                    _ => false,
-                }
+                matches!(
+                    inner.try_type_variables_probe_ref(ty_var),
+                    Some(TypeVariableValue::Unknown { .. })
+                )
             }
             _ => false,
         };
diff --git a/compiler/rustc_infer/src/traits/mod.rs b/compiler/rustc_infer/src/traits/mod.rs
index e01b6caf430..9dd4f0a8e4c 100644
--- a/compiler/rustc_infer/src/traits/mod.rs
+++ b/compiler/rustc_infer/src/traits/mod.rs
@@ -89,10 +89,10 @@ impl<'tcx> PredicateObligation<'tcx> {
 impl<'tcx> TraitObligation<'tcx> {
     /// Returns `true` if the trait predicate is considered `const` in its ParamEnv.
     pub fn is_const(&self) -> bool {
-        match (self.predicate.skip_binder().constness, self.param_env.constness()) {
-            (ty::BoundConstness::ConstIfConst, hir::Constness::Const) => true,
-            _ => false,
-        }
+        matches!(
+            (self.predicate.skip_binder().constness, self.param_env.constness()),
+            (ty::BoundConstness::ConstIfConst, hir::Constness::Const)
+        )
     }
 
     pub fn derived_cause(
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs
index b4edb02f6c4..1ddc08eac7d 100644
--- a/compiler/rustc_middle/src/lib.rs
+++ b/compiler/rustc_middle/src/lib.rs
@@ -99,13 +99,9 @@ pub mod mir;
 pub mod thir;
 pub mod traits;
 pub mod ty;
+pub mod util;
 mod values;
 
-pub mod util {
-    pub mod bug;
-    pub mod common;
-}
-
 // Allows macros to refer to this crate as `::rustc_middle`
 extern crate self as rustc_middle;
 
diff --git a/compiler/rustc_const_eval/src/util/call_kind.rs b/compiler/rustc_middle/src/util/call_kind.rs
index 995363c0edd..627c84c388c 100644
--- a/compiler/rustc_const_eval/src/util/call_kind.rs
+++ b/compiler/rustc_middle/src/util/call_kind.rs
@@ -2,10 +2,10 @@
 //! as well as errors when attempting to call a non-const function in a const
 //! context.
 
+use crate::ty::subst::SubstsRef;
+use crate::ty::{AssocItemContainer, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{lang_items, LangItem};
-use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{AssocItemContainer, Instance, ParamEnv, Ty, TyCtxt};
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, DesugaringKind, Span};
 
diff --git a/compiler/rustc_const_eval/src/util/find_self_call.rs b/compiler/rustc_middle/src/util/find_self_call.rs
index 33ad128eeeb..0eab0adf07e 100644
--- a/compiler/rustc_const_eval/src/util/find_self_call.rs
+++ b/compiler/rustc_middle/src/util/find_self_call.rs
@@ -1,6 +1,6 @@
-use rustc_middle::mir::*;
-use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, TyCtxt};
+use crate::mir::*;
+use crate::ty::subst::SubstsRef;
+use crate::ty::{self, TyCtxt};
 use rustc_span::def_id::DefId;
 
 /// Checks if the specified `local` is used as the `self` parameter of a method call
diff --git a/compiler/rustc_middle/src/util/mod.rs b/compiler/rustc_middle/src/util/mod.rs
new file mode 100644
index 00000000000..53b4257899b
--- /dev/null
+++ b/compiler/rustc_middle/src/util/mod.rs
@@ -0,0 +1,7 @@
+pub mod bug;
+pub mod call_kind;
+pub mod common;
+pub mod find_self_call;
+
+pub use call_kind::{call_kind, CallDesugaringKind, CallKind};
+pub use find_self_call::find_self_call;
diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs
index 43e787db41a..dcdeaf008d6 100644
--- a/compiler/rustc_mir_build/src/errors.rs
+++ b/compiler/rustc_mir_build/src/errors.rs
@@ -384,13 +384,8 @@ impl<'a> IntoDiagnostic<'a> for NonExhaustivePatternsTypeNotEmpty<'_, '_, '_> {
             diag.span_note(span, fluent::mir_build_def_note);
         }
 
-        let is_variant_list_non_exhaustive = match self.ty.kind() {
-            ty::Adt(def, _) if def.is_variant_list_non_exhaustive() && !def.did().is_local() => {
-                true
-            }
-            _ => false,
-        };
-
+        let is_variant_list_non_exhaustive = matches!(self.ty.kind(),
+            ty::Adt(def, _) if def.is_variant_list_non_exhaustive() && !def.did().is_local());
         if is_variant_list_non_exhaustive {
             diag.note(fluent::mir_build_non_exhaustive_type_note);
         } else {
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index bac46db2b1e..0ef48c42f87 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -671,10 +671,8 @@ fn non_exhaustive_match<'p, 'tcx>(
         };
     };
 
-    let is_variant_list_non_exhaustive = match scrut_ty.kind() {
-        ty::Adt(def, _) if def.is_variant_list_non_exhaustive() && !def.did().is_local() => true,
-        _ => false,
-    };
+    let is_variant_list_non_exhaustive = matches!(scrut_ty.kind(),
+        ty::Adt(def, _) if def.is_variant_list_non_exhaustive() && !def.did().is_local());
 
     adt_defined_here(cx, &mut err, scrut_ty, &witnesses);
     err.note(&format!(
diff --git a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
index 3d32c586554..57b24c9c552 100644
--- a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
+++ b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
@@ -134,7 +134,12 @@ impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
                 // the `self` parameter of a method call (as the terminator of our current
                 // BasicBlock). If so, we emit a more specific lint.
                 let method_did = self.target_local.and_then(|target_local| {
-                    crate::util::find_self_call(self.tcx, &self.body, target_local, loc.block)
+                    rustc_middle::util::find_self_call(
+                        self.tcx,
+                        &self.body,
+                        target_local,
+                        loc.block,
+                    )
                 });
                 let lint_loc =
                     if method_did.is_some() { self.body.terminator_loc(loc.block) } else { loc };
diff --git a/compiler/rustc_mir_transform/src/coverage/debug.rs b/compiler/rustc_mir_transform/src/coverage/debug.rs
index 725883b83fa..e554c470646 100644
--- a/compiler/rustc_mir_transform/src/coverage/debug.rs
+++ b/compiler/rustc_mir_transform/src/coverage/debug.rs
@@ -292,10 +292,8 @@ impl DebugCounters {
     }
 
     pub fn some_block_label(&self, operand: ExpressionOperandId) -> Option<&String> {
-        self.some_counters.as_ref().map_or(None, |counters| {
-            counters
-                .get(&operand)
-                .map_or(None, |debug_counter| debug_counter.some_block_label.as_ref())
+        self.some_counters.as_ref().and_then(|counters| {
+            counters.get(&operand).and_then(|debug_counter| debug_counter.some_block_label.as_ref())
         })
     }
 
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index 6422b8ac1ba..f5fef6ad019 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -2577,14 +2577,12 @@ impl<'a> Parser<'a> {
     }
 
     fn recover_self_param(&mut self) -> bool {
-        match self
-            .parse_outer_attributes()
-            .and_then(|_| self.parse_self_param())
-            .map_err(|e| e.cancel())
-        {
-            Ok(Some(_)) => true,
-            _ => false,
-        }
+        matches!(
+            self.parse_outer_attributes()
+                .and_then(|_| self.parse_self_param())
+                .map_err(|e| e.cancel()),
+            Ok(Some(_))
+        )
     }
 }
 
diff --git a/compiler/rustc_parse/src/parser/nonterminal.rs b/compiler/rustc_parse/src/parser/nonterminal.rs
index 7a4d53ed8bb..adb0d372a40 100644
--- a/compiler/rustc_parse/src/parser/nonterminal.rs
+++ b/compiler/rustc_parse/src/parser/nonterminal.rs
@@ -20,12 +20,10 @@ impl<'a> Parser<'a> {
     pub fn nonterminal_may_begin_with(kind: NonterminalKind, token: &Token) -> bool {
         /// Checks whether the non-terminal may contain a single (non-keyword) identifier.
         fn may_be_ident(nt: &token::Nonterminal) -> bool {
-            match *nt {
-                token::NtItem(_) | token::NtBlock(_) | token::NtVis(_) | token::NtLifetime(_) => {
-                    false
-                }
-                _ => true,
-            }
+            !matches!(
+                *nt,
+                token::NtItem(_) | token::NtBlock(_) | token::NtVis(_) | token::NtLifetime(_)
+            )
         }
 
         match kind {
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 0c9d306081e..c5ec19732be 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -663,15 +663,17 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         Ident::with_dummy_span(name),
                         Namespace::ValueNS,
                         &parent_scope,
-                        &|res: Res| match res {
-                            Res::Def(
-                                DefKind::Ctor(CtorOf::Variant, CtorKind::Const)
-                                | DefKind::Ctor(CtorOf::Struct, CtorKind::Const)
-                                | DefKind::Const
-                                | DefKind::AssocConst,
-                                _,
-                            ) => true,
-                            _ => false,
+                        &|res: Res| {
+                            matches!(
+                                res,
+                                Res::Def(
+                                    DefKind::Ctor(CtorOf::Variant, CtorKind::Const)
+                                        | DefKind::Ctor(CtorOf::Struct, CtorKind::Const)
+                                        | DefKind::Const
+                                        | DefKind::AssocConst,
+                                    _,
+                                )
+                            )
                         },
                     );
 
diff --git a/compiler/rustc_transmute/src/layout/tree.rs b/compiler/rustc_transmute/src/layout/tree.rs
index 2a89494c80b..a6d88b1342a 100644
--- a/compiler/rustc_transmute/src/layout/tree.rs
+++ b/compiler/rustc_transmute/src/layout/tree.rs
@@ -196,7 +196,7 @@ pub(crate) mod rustc {
         fn from(err: LayoutError<'tcx>) -> Self {
             match err {
                 LayoutError::Unknown(..) => Self::Unknown,
-                err @ _ => unimplemented!("{:?}", err),
+                err => unimplemented!("{:?}", err),
             }
         }
     }
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index f6088f4e64a..eeee12a4310 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -141,7 +141,7 @@ where
         let f = auto_trait::AutoTraitFinder::new(tcx);
 
         debug!("get_auto_trait_impls({:?})", ty);
-        let auto_traits: Vec<_> = self.cx.auto_traits.iter().copied().collect();
+        let auto_traits: Vec<_> = self.cx.auto_traits.to_vec();
         let mut auto_traits: Vec<Item> = auto_traits
             .into_iter()
             .filter_map(|trait_def_id| {