Update Clippy

src/tools/clippy/CHANGELOG.md

@@ -4844,6 +4844,7 @@ Released 2018-09-13
 [`field_reassign_with_default`]: https://rust-lang.github.io/rust-clippy/master/index.html#field_reassign_with_default
 [`filetype_is_file`]: https://rust-lang.github.io/rust-clippy/master/index.html#filetype_is_file
 [`filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map
+[`filter_map_bool_then`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_bool_then
 [`filter_map_identity`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_identity
 [`filter_map_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_next
 [`filter_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_next
@@ -4889,12 +4890,14 @@ Released 2018-09-13
 [`if_same_then_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_same_then_else
 [`if_then_some_else_none`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_then_some_else_none
 [`ifs_same_cond`]: https://rust-lang.github.io/rust-clippy/master/index.html#ifs_same_cond
+[`ignored_unit_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#ignored_unit_patterns
 [`impl_trait_in_params`]: https://rust-lang.github.io/rust-clippy/master/index.html#impl_trait_in_params
 [`implicit_clone`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_clone
 [`implicit_hasher`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_hasher
 [`implicit_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_return
 [`implicit_saturating_add`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_saturating_add
 [`implicit_saturating_sub`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_saturating_sub
+[`impossible_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#impossible_comparisons
 [`imprecise_flops`]: https://rust-lang.github.io/rust-clippy/master/index.html#imprecise_flops
 [`inconsistent_digit_grouping`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_digit_grouping
 [`inconsistent_struct_constructor`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_struct_constructor
@@ -5189,6 +5192,7 @@ Released 2018-09-13
 [`redundant_closure`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
 [`redundant_closure_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_call
 [`redundant_closure_for_method_calls`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure_for_method_calls
+[`redundant_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_comparisons
 [`redundant_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_else
 [`redundant_feature_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_feature_names
 [`redundant_field_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names

src/tools/clippy/clippy_dev/src/main.rs

@@ -41,7 +41,7 @@ fn main() {
                 matches.get_one::<String>("type").map(String::as_str),
                 matches.get_flag("msrv"),
             ) {
-                Ok(_) => update_lints::update(update_lints::UpdateMode::Change),
+                Ok(()) => update_lints::update(update_lints::UpdateMode::Change),
                 Err(e) => eprintln!("Unable to create lint: {e}"),
             }
         },

src/tools/clippy/clippy_dev/src/setup/vscode.rs

@@ -47,7 +47,7 @@ fn check_install_precondition(force_override: bool) -> bool {
         }
     } else {
         match fs::create_dir(vs_dir_path) {
-            Ok(_) => {
+            Ok(()) => {
                 println!("info: created `{VSCODE_DIR}` directory for clippy");
             },
             Err(err) => {

src/tools/clippy/clippy_lints/src/casts/ptr_as_ptr.rs

@@ -1,9 +1,7 @@
-use std::borrow::Cow;
-
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::msrvs::{self, Msrv};
+use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
-use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, Mutability, TyKind};
 use rustc_lint::LateContext;
@@ -16,33 +14,41 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, msrv: &Msrv) {
         return;
     }
 
-    if_chain! {
-        if let ExprKind::Cast(cast_expr, cast_to_hir_ty) = expr.kind;
-        let (cast_from, cast_to) = (cx.typeck_results().expr_ty(cast_expr), cx.typeck_results().expr_ty(expr));
-        if let ty::RawPtr(TypeAndMut { mutbl: from_mutbl, .. }) = cast_from.kind();
-        if let ty::RawPtr(TypeAndMut { ty: to_pointee_ty, mutbl: to_mutbl }) = cast_to.kind();
-        if matches!((from_mutbl, to_mutbl),
-            (Mutability::Not, Mutability::Not) | (Mutability::Mut, Mutability::Mut));
+    if let ExprKind::Cast(cast_expr, cast_to_hir_ty) = expr.kind
+        && let (cast_from, cast_to) = (cx.typeck_results().expr_ty(cast_expr), cx.typeck_results().expr_ty(expr))
+        && let ty::RawPtr(TypeAndMut { mutbl: from_mutbl, .. }) = cast_from.kind()
+        && let ty::RawPtr(TypeAndMut { ty: to_pointee_ty, mutbl: to_mutbl }) = cast_to.kind()
+        && matches!((from_mutbl, to_mutbl),
+            (Mutability::Not, Mutability::Not) | (Mutability::Mut, Mutability::Mut))
         // The `U` in `pointer::cast` have to be `Sized`
         // as explained here: https://github.com/rust-lang/rust/issues/60602.
-        if to_pointee_ty.is_sized(cx.tcx, cx.param_env);
-        then {
-            let mut applicability = Applicability::MachineApplicable;
-            let cast_expr_sugg = Sugg::hir_with_applicability(cx, cast_expr, "_", &mut applicability);
-            let turbofish = match &cast_to_hir_ty.kind {
-                    TyKind::Infer => Cow::Borrowed(""),
-                    TyKind::Ptr(mut_ty) if matches!(mut_ty.ty.kind, TyKind::Infer) => Cow::Borrowed(""),
-                    _ => Cow::Owned(format!("::<{to_pointee_ty}>")),
-                };
-            span_lint_and_sugg(
-                cx,
-                PTR_AS_PTR,
-                expr.span,
-                "`as` casting between raw pointers without changing its mutability",
-                "try `pointer::cast`, a safer alternative",
-                format!("{}.cast{turbofish}()", cast_expr_sugg.maybe_par()),
-                applicability,
-            );
-        }
+        && to_pointee_ty.is_sized(cx.tcx, cx.param_env)
+    {
+        let mut app = Applicability::MachineApplicable;
+        let cast_expr_sugg = Sugg::hir_with_applicability(cx, cast_expr, "_", &mut app);
+        let turbofish = match &cast_to_hir_ty.kind {
+            TyKind::Infer => String::new(),
+            TyKind::Ptr(mut_ty) => {
+                if matches!(mut_ty.ty.kind, TyKind::Infer) {
+                    String::new()
+                } else {
+                    format!(
+                        "::<{}>",
+                        snippet_with_applicability(cx, mut_ty.ty.span, "/* type */", &mut app)
+                    )
+                }
+            },
+            _ => return,
+        };
+
+        span_lint_and_sugg(
+            cx,
+            PTR_AS_PTR,
+            expr.span,
+            "`as` casting between raw pointers without changing its mutability",
+            "try `pointer::cast`, a safer alternative",
+            format!("{}.cast{turbofish}()", cast_expr_sugg.maybe_par()),
+            app,
+        );
     }
 }

src/tools/clippy/clippy_lints/src/declared_lints.rs

@@ -203,6 +203,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::if_let_mutex::IF_LET_MUTEX_INFO,
     crate::if_not_else::IF_NOT_ELSE_INFO,
     crate::if_then_some_else_none::IF_THEN_SOME_ELSE_NONE_INFO,
+    crate::ignored_unit_patterns::IGNORED_UNIT_PATTERNS_INFO,
     crate::implicit_hasher::IMPLICIT_HASHER_INFO,
     crate::implicit_return::IMPLICIT_RETURN_INFO,
     crate::implicit_saturating_add::IMPLICIT_SATURATING_ADD_INFO,
@@ -337,6 +338,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::methods::EXPECT_USED_INFO,
     crate::methods::EXTEND_WITH_DRAIN_INFO,
     crate::methods::FILETYPE_IS_FILE_INFO,
+    crate::methods::FILTER_MAP_BOOL_THEN_INFO,
     crate::methods::FILTER_MAP_IDENTITY_INFO,
     crate::methods::FILTER_MAP_NEXT_INFO,
     crate::methods::FILTER_NEXT_INFO,
@@ -516,6 +518,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::operators::FLOAT_CMP_CONST_INFO,
     crate::operators::FLOAT_EQUALITY_WITHOUT_ABS_INFO,
     crate::operators::IDENTITY_OP_INFO,
+    crate::operators::IMPOSSIBLE_COMPARISONS_INFO,
     crate::operators::INEFFECTIVE_BIT_MASK_INFO,
     crate::operators::INTEGER_DIVISION_INFO,
     crate::operators::MISREFACTORED_ASSIGN_OP_INFO,
@@ -524,6 +527,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::operators::NEEDLESS_BITWISE_BOOL_INFO,
     crate::operators::OP_REF_INFO,
     crate::operators::PTR_EQ_INFO,
+    crate::operators::REDUNDANT_COMPARISONS_INFO,
     crate::operators::SELF_ASSIGNMENT_INFO,
     crate::operators::VERBOSE_BIT_MASK_INFO,
     crate::option_env_unwrap::OPTION_ENV_UNWRAP_INFO,

src/tools/clippy/clippy_lints/src/derive.rs

@@ -1,22 +1,19 @@
-use clippy_utils::diagnostics::{
-    span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then,
-};
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::ty::{implements_trait, implements_trait_with_env, is_copy};
 use clippy_utils::{is_lint_allowed, match_def_path, paths};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
 use rustc_hir::{
-    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Impl, Item, ItemKind,
-    UnsafeSource, Unsafety,
+    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Impl, Item, ItemKind, UnsafeSource, Unsafety,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::traits::Reveal;
 use rustc_middle::ty::{
-    self, ClauseKind, GenericArgKind, GenericParamDefKind, ImplPolarity, ParamEnv,
-    ToPredicate, TraitPredicate, Ty, TyCtxt,
+    self, ClauseKind, GenericArgKind, GenericParamDefKind, ImplPolarity, ParamEnv, ToPredicate, TraitPredicate, Ty,
+    TyCtxt,
 };
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::def_id::LocalDefId;
@@ -207,10 +204,13 @@ declare_lint_pass!(Derive => [
 
 impl<'tcx> LateLintPass<'tcx> for Derive {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Impl(Impl { of_trait: Some(ref trait_ref), .. }) = item.kind {
+        if let ItemKind::Impl(Impl {
+            of_trait: Some(ref trait_ref),
+            ..
+        }) = item.kind
+        {
             let ty = cx.tcx.type_of(item.owner_id).instantiate_identity();
-            let is_automatically_derived =
-                cx.tcx.has_attr(item.owner_id, sym::automatically_derived);
+            let is_automatically_derived = cx.tcx.has_attr(item.owner_id, sym::automatically_derived);
 
             check_hash_peq(cx, item.span, trait_ref, ty, is_automatically_derived);
             check_ord_partial_ord(cx, item.span, trait_ref, ty, is_automatically_derived);
@@ -327,12 +327,7 @@ fn check_ord_partial_ord<'tcx>(
 }
 
 /// Implementation of the `EXPL_IMPL_CLONE_ON_COPY` lint.
-fn check_copy_clone<'tcx>(
-    cx: &LateContext<'tcx>,
-    item: &Item<'_>,
-    trait_ref: &hir::TraitRef<'_>,
-    ty: Ty<'tcx>,
-) {
+fn check_copy_clone<'tcx>(cx: &LateContext<'tcx>, item: &Item<'_>, trait_ref: &hir::TraitRef<'_>, ty: Ty<'tcx>) {
     let clone_id = match cx.tcx.lang_items().clone_trait() {
         Some(id) if trait_ref.trait_def_id() == Some(id) => id,
         _ => return,
@@ -350,9 +345,10 @@ fn check_copy_clone<'tcx>(
     if !is_copy(cx, ty) {
         if ty_subs.non_erasable_generics().next().is_some() {
             let has_copy_impl = cx.tcx.all_local_trait_impls(()).get(&copy_id).map_or(false, |impls| {
-                impls
-                    .iter()
-                    .any(|&id| matches!(cx.tcx.type_of(id).instantiate_identity().kind(), ty::Adt(adt, _) if ty_adt.did() == adt.did()))
+                impls.iter().any(|&id| {
+                    matches!(cx.tcx.type_of(id).instantiate_identity().kind(), ty::Adt(adt, _)
+                                        if ty_adt.did() == adt.did())
+                })
             });
             if !has_copy_impl {
                 return;
@@ -431,14 +427,7 @@ struct UnsafeVisitor<'a, 'tcx> {
 impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
     type NestedFilter = nested_filter::All;
 
-    fn visit_fn(
-        &mut self,
-        kind: FnKind<'tcx>,
-        decl: &'tcx FnDecl<'_>,
-        body_id: BodyId,
-        _: Span,
-        id: LocalDefId,
-    ) {
+    fn visit_fn(&mut self, kind: FnKind<'tcx>, decl: &'tcx FnDecl<'_>, body_id: BodyId, _: Span, id: LocalDefId) {
         if self.has_unsafe {
             return;
         }
@@ -474,12 +463,7 @@ impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
 }
 
 /// Implementation of the `DERIVE_PARTIAL_EQ_WITHOUT_EQ` lint.
-fn check_partial_eq_without_eq<'tcx>(
-    cx: &LateContext<'tcx>,
-    span: Span,
-    trait_ref: &hir::TraitRef<'_>,
-    ty: Ty<'tcx>,
-) {
+fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_ref: &hir::TraitRef<'_>, ty: Ty<'tcx>) {
     if_chain! {
         if let ty::Adt(adt, args) = ty.kind();
         if cx.tcx.visibility(adt.did()).is_public();

src/tools/clippy/clippy_lints/src/doc.rs

@@ -716,10 +716,7 @@ fn check_code(cx: &LateContext<'_>, text: &str, edition: Edition, span: Span) {
                 let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
                 let fallback_bundle =
                     rustc_errors::fallback_fluent_bundle(rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(), false);
-                let emitter = EmitterWriter::new(
-                    Box::new(io::sink()),
-                    fallback_bundle,
-                );
+                let emitter = EmitterWriter::new(Box::new(io::sink()), fallback_bundle);
                 let handler = Handler::with_emitter(Box::new(emitter)).disable_warnings();
                 let sess = ParseSess::with_span_handler(handler, sm);
 

src/tools/clippy/clippy_lints/src/eta_reduction.rs

@@ -10,8 +10,8 @@ use rustc_hir::{BindingAnnotation, Expr, ExprKind, FnRetTy, Param, PatKind, QPat
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{
-    self, Binder, ClosureArgs, ClosureKind, EarlyBinder, FnSig, GenericArg, GenericArgKind,
-    GenericArgsRef, ImplPolarity, List, Region, RegionKind, Ty, TypeVisitableExt, TypeckResults,
+    self, Binder, ClosureArgs, ClosureKind, EarlyBinder, FnSig, GenericArg, GenericArgKind, GenericArgsRef,
+    ImplPolarity, List, Region, RegionKind, Ty, TypeVisitableExt, TypeckResults,
 };
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::sym;

src/tools/clippy/clippy_lints/src/ignored_unit_patterns.rs

@@ -0,0 +1,52 @@
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use hir::PatKind;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for usage of `_` in patterns of type `()`.
+    ///
+    /// ### Why is this bad?
+    /// Matching with `()` explicitly instead of `_` outlines
+    /// the fact that the pattern contains no data. Also it
+    /// would detect a type change that `_` would ignore.
+    ///
+    /// ### Example
+    /// ```rust
+    /// match std::fs::create_dir("tmp-work-dir") {
+    ///    Ok(_) => println!("Working directory created"),
+    ///    Err(s) => eprintln!("Could not create directory: {s}"),
+    /// }
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// match std::fs::create_dir("tmp-work-dir") {
+    ///    Ok(()) => println!("Working directory created"),
+    ///    Err(s) => eprintln!("Could not create directory: {s}"),
+    /// }
+    /// ```
+    #[clippy::version = "1.73.0"]
+    pub IGNORED_UNIT_PATTERNS,
+    pedantic,
+    "suggest replacing `_` by `()` in patterns where appropriate"
+}
+declare_lint_pass!(IgnoredUnitPatterns => [IGNORED_UNIT_PATTERNS]);
+
+impl<'tcx> LateLintPass<'tcx> for IgnoredUnitPatterns {
+    fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx hir::Pat<'tcx>) {
+        if matches!(pat.kind, PatKind::Wild) && cx.typeck_results().pat_ty(pat).is_unit() {
+            span_lint_and_sugg(
+                cx,
+                IGNORED_UNIT_PATTERNS,
+                pat.span,
+                "matching over `()` is more explicit",
+                "use `()` instead of `_`",
+                String::from("()"),
+                Applicability::MachineApplicable,
+            );
+        }
+    }
+}

src/tools/clippy/clippy_lints/src/lib.rs

@@ -147,6 +147,7 @@ mod future_not_send;
 mod if_let_mutex;
 mod if_not_else;
 mod if_then_some_else_none;
+mod ignored_unit_patterns;
 mod implicit_hasher;
 mod implicit_return;
 mod implicit_saturating_add;
@@ -1093,6 +1094,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         })
     });
     store.register_late_pass(|_| Box::new(redundant_locals::RedundantLocals));
+    store.register_late_pass(|_| Box::new(ignored_unit_patterns::IgnoredUnitPatterns));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 

src/tools/clippy/clippy_lints/src/loops/never_loop.rs

@@ -162,7 +162,9 @@ fn never_loop_expr<'tcx>(
         ExprKind::Binary(_, e1, e2)
         | ExprKind::Assign(e1, e2, _)
         | ExprKind::AssignOp(_, e1, e2)
-        | ExprKind::Index(e1, e2, _) => never_loop_expr_all(cx, &mut [e1, e2].iter().copied(), ignore_ids, main_loop_id),
+        | ExprKind::Index(e1, e2, _) => {
+            never_loop_expr_all(cx, &mut [e1, e2].iter().copied(), ignore_ids, main_loop_id)
+        },
         ExprKind::Loop(b, _, _, _) => {
             // Break can come from the inner loop so remove them.
             absorb_break(never_loop_block(cx, b, ignore_ids, main_loop_id))

src/tools/clippy/clippy_lints/src/manual_float_methods.rs

@@ -84,7 +84,7 @@ impl<'tcx> LateLintPass<'tcx> for ManualFloatMethods {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
         if !in_external_macro(cx.sess(), expr.span)
             && (
-                matches!(cx.tcx.constness(cx.tcx.hir().enclosing_body_owner(expr.hir_id)), Constness::NotConst) 
+                matches!(cx.tcx.constness(cx.tcx.hir().enclosing_body_owner(expr.hir_id)), Constness::NotConst)
                     || cx.tcx.features().active(sym!(const_float_classify))
             ) && let ExprKind::Binary(kind, lhs, rhs) = expr.kind
             && let ExprKind::Binary(lhs_kind, lhs_lhs, lhs_rhs) = lhs.kind