Merge commit '435a8ad86c7a33bd7ffb91c59039943408d3b6aa' into clippyup

.github/workflows/clippy.yml

@@ -39,7 +39,7 @@ jobs:
         github_token: "${{ secrets.github_token }}"
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Install toolchain
       run: rustup show active-toolchain

.github/workflows/clippy_bors.yml

@@ -27,7 +27,7 @@ jobs:
         github_token: "${{ secrets.github_token }}"
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
       with:
         ref: ${{ github.ref }}
 
@@ -83,7 +83,7 @@ jobs:
         github_token: "${{ secrets.github_token }}"
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Install toolchain
       run: rustup show active-toolchain
@@ -149,7 +149,7 @@ jobs:
         github_token: "${{ secrets.github_token }}"
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Install toolchain
       run: rustup show active-toolchain
@@ -173,7 +173,7 @@ jobs:
         github_token: "${{ secrets.github_token }}"
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Install toolchain
       run: rustup show active-toolchain
@@ -233,7 +233,7 @@ jobs:
         github_token: "${{ secrets.github_token }}"
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Install toolchain
       run: rustup show active-toolchain

.github/workflows/clippy_dev.yml

@@ -25,7 +25,7 @@ jobs:
     steps:
     # Setup
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     # Run
     - name: Build

.github/workflows/deploy.yml

@@ -21,10 +21,10 @@ jobs:
     steps:
     # Setup
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
       with:
         ref: ${{ env.TARGET_BRANCH }}
         path: 'out'

.github/workflows/remark.yml

@@ -16,10 +16,10 @@ jobs:
     steps:
     # Setup
     - name: Checkout
-      uses: actions/checkout@v3.0.2
+      uses: actions/checkout@v3
 
     - name: Setup Node.js
-      uses: actions/setup-node@v1.4.4
+      uses: actions/setup-node@v3
       with:
         node-version: '14.x'
 

CHANGELOG.md

@@ -4620,6 +4620,7 @@ Released 2018-09-13
 [`else_if_without_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#else_if_without_else
 [`empty_drop`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_drop
 [`empty_enum`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_enum
+[`empty_line_after_doc_comments`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_doc_comments
 [`empty_line_after_outer_attr`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_outer_attr
 [`empty_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_loop
 [`empty_structs_with_brackets`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_structs_with_brackets
@@ -4785,6 +4786,7 @@ Released 2018-09-13
 [`manual_main_separator_str`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_main_separator_str
 [`manual_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_map
 [`manual_memcpy`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_memcpy
+[`manual_next_back`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_next_back
 [`manual_non_exhaustive`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive
 [`manual_ok_or`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_ok_or
 [`manual_range_contains`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains
@@ -4897,6 +4899,7 @@ Released 2018-09-13
 [`no_effect_underscore_binding`]: https://rust-lang.github.io/rust-clippy/master/index.html#no_effect_underscore_binding
 [`no_mangle_with_rust_abi`]: https://rust-lang.github.io/rust-clippy/master/index.html#no_mangle_with_rust_abi
 [`non_ascii_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_ascii_literal
+[`non_minimal_cfg`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_minimal_cfg
 [`non_octal_unix_permissions`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_octal_unix_permissions
 [`non_send_fields_in_send_ty`]: https://rust-lang.github.io/rust-clippy/master/index.html#non_send_fields_in_send_ty
 [`nonminimal_bool`]: https://rust-lang.github.io/rust-clippy/master/index.html#nonminimal_bool
@@ -4978,6 +4981,7 @@ Released 2018-09-13
 [`ref_binding_to_reference`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_binding_to_reference
 [`ref_in_deref`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_in_deref
 [`ref_option_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_option_ref
+[`ref_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_patterns
 [`regex_macro`]: https://rust-lang.github.io/rust-clippy/master/index.html#regex_macro
 [`repeat_once`]: https://rust-lang.github.io/rust-clippy/master/index.html#repeat_once
 [`replace_consts`]: https://rust-lang.github.io/rust-clippy/master/index.html#replace_consts

README.md

@@ -278,7 +278,7 @@ If you want to contribute to Clippy, you can find more information in [CONTRIBUT
 
 <!-- REUSE-IgnoreStart -->
 
-Copyright 2014-2022 The Rust Project Developers
+Copyright 2014-2023 The Rust Project Developers
 
 Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
 [https://www.apache.org/licenses/LICENSE-2.0](https://www.apache.org/licenses/LICENSE-2.0)> or the MIT license

book/src/development/type_checking.md

@@ -133,7 +133,7 @@ in this chapter:
 - [Type checking](https://rustc-dev-guide.rust-lang.org/type-checking.html)
 - [Ty module](https://rustc-dev-guide.rust-lang.org/ty.html)
 
-[Adt]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/enum.TyKind.html#variant.Adt
+[Adt]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_type_ir/sty/enum.TyKind.html#variant.Adt
 [AdtDef]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/adt/struct.AdtDef.html
 [expr_ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TypeckResults.html#method.expr_ty
 [node_type]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TypeckResults.html#method.node_type
@@ -142,9 +142,9 @@ in this chapter:
 [kind]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.Ty.html#method.kind
 [LateContext]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LateContext.html
 [LateLintPass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.LateLintPass.html
-[pat_ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/context/struct.TypeckResults.html#method.pat_ty
+[pat_ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/typeck_results/struct.TypeckResults.html#method.pat_ty
 [Ty]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.Ty.html
-[TyKind]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/enum.TyKind.html
+[TyKind]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_type_ir/sty/enum.TyKind.html
 [TypeckResults]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/struct.TypeckResults.html
 [middle_ty]: https://doc.rust-lang.org/beta/nightly-rustc/rustc_middle/ty/struct.Ty.html
 [hir_ty]: https://doc.rust-lang.org/beta/nightly-rustc/rustc_hir/struct.Ty.html

clippy_lints/Cargo.toml

@@ -17,7 +17,7 @@ if_chain = "1.0"
 itertools = "0.10.1"
 pulldown-cmark = { version = "0.9", default-features = false }
 quine-mc_cluskey = "0.2"
-regex-syntax = "0.6"
+regex-syntax = "0.7"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = { version = "1.0", optional = true }
 tempfile = { version = "3.2", optional = true }

clippy_lints/src/assertions_on_constants.rs

@@ -38,7 +38,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
             _ => return,
         };
         let Some((condition, panic_expn)) = find_assert_args(cx, e, macro_call.expn) else { return };
-        let Some((Constant::Bool(val), _)) = constant(cx, cx.typeck_results(), condition) else { return };
+        let Some(Constant::Bool(val)) = constant(cx, cx.typeck_results(), condition) else { return };
         if val {
             span_lint_and_help(
                 cx,

clippy_lints/src/attrs.rs

@@ -176,6 +176,52 @@ declare_clippy_lint! {
     "empty line after outer attribute"
 }
 
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for empty lines after documenation comments.
+    ///
+    /// ### Why is this bad?
+    /// The documentation comment was most likely meant to be an inner attribute or regular comment.
+    /// If it was intended to be a documentation comment, then the empty line should be removed to
+    /// be more idiomatic.
+    ///
+    /// ### Known problems
+    /// Only detects empty lines immediately following the documentation. If the doc comment is followed
+    /// by an attribute and then an empty line, this lint will not trigger. Use `empty_line_after_outer_attr`
+    /// in combination with this lint to detect both cases.
+    ///
+    /// Does not detect empty lines after doc attributes (e.g. `#[doc = ""]`).
+    ///
+    /// ### Example
+    /// ```rust
+    /// /// Some doc comment with a blank line after it.
+    ///
+    /// fn not_quite_good_code() { }
+    /// ```
+    ///
+    /// Use instead:
+    /// ```rust
+    /// /// Good (no blank line)
+    /// fn this_is_fine() { }
+    /// ```
+    ///
+    /// ```rust
+    /// // Good (convert to a regular comment)
+    ///
+    /// fn this_is_fine_too() { }
+    /// ```
+    ///
+    /// ```rust
+    /// //! Good (convert to a comment on an inner attribute)
+    ///
+    /// fn this_is_fine_as_well() { }
+    /// ```
+    #[clippy::version = "1.70.0"]
+    pub EMPTY_LINE_AFTER_DOC_COMMENTS,
+    nursery,
+    "empty line after documentation comments"
+}
+
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for `warn`/`deny`/`forbid` attributes targeting the whole clippy::restriction category.
@@ -292,6 +338,30 @@ declare_clippy_lint! {
     "ensures that all `allow` and `expect` attributes have a reason"
 }
 
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for `any` and `all` combinators in `cfg` with only one condition.
+    ///
+    /// ### Why is this bad?
+    /// If there is only one condition, no need to wrap it into `any` or `all` combinators.
+    ///
+    /// ### Example
+    /// ```rust
+    /// #[cfg(any(unix))]
+    /// pub struct Bar;
+    /// ```
+    ///
+    /// Use instead:
+    /// ```rust
+    /// #[cfg(unix)]
+    /// pub struct Bar;
+    /// ```
+    #[clippy::version = "1.71.0"]
+    pub NON_MINIMAL_CFG,
+    style,
+    "ensure that all `cfg(any())` and `cfg(all())` have more than one condition"
+}
+
 declare_lint_pass!(Attributes => [
     ALLOW_ATTRIBUTES_WITHOUT_REASON,
     INLINE_ALWAYS,
@@ -604,6 +674,8 @@ impl_lint_pass!(EarlyAttributes => [
     DEPRECATED_CFG_ATTR,
     MISMATCHED_TARGET_OS,
     EMPTY_LINE_AFTER_OUTER_ATTR,
+    EMPTY_LINE_AFTER_DOC_COMMENTS,
+    NON_MINIMAL_CFG,
 ]);
 
 impl EarlyLintPass for EarlyAttributes {
@@ -614,15 +686,22 @@ impl EarlyLintPass for EarlyAttributes {
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
         check_deprecated_cfg_attr(cx, attr, &self.msrv);
         check_mismatched_target_os(cx, attr);
+        check_minimal_cfg_condition(cx, attr);
     }
 
     extract_msrv_attr!(EarlyContext);
 }
 
+/// Check for empty lines after outer attributes.
+///
+/// Attributes and documenation comments are both considered outer attributes
+/// by the AST. However, the average user likely considers them to be different.
+/// Checking for empty lines after each of these attributes is split into two different
+/// lints but can share the same logic.
 fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::Item) {
     let mut iter = item.attrs.iter().peekable();
     while let Some(attr) = iter.next() {
-        if matches!(attr.kind, AttrKind::Normal(..))
+        if (matches!(attr.kind, AttrKind::Normal(..)) || matches!(attr.kind, AttrKind::DocComment(..)))
             && attr.style == AttrStyle::Outer
             && is_present_in_source(cx, attr.span)
         {
@@ -639,13 +718,20 @@ fn check_empty_line_after_outer_attr(cx: &EarlyContext<'_>, item: &rustc_ast::It
                 let lines = without_block_comments(lines);
 
                 if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 {
-                    span_lint(
-                        cx,
-                        EMPTY_LINE_AFTER_OUTER_ATTR,
-                        begin_of_attr_to_item,
-                        "found an empty line after an outer attribute. \
-                        Perhaps you forgot to add a `!` to make it an inner attribute?",
-                    );
+                    let (lint_msg, lint_type) = match attr.kind {
+                        AttrKind::DocComment(..) => (
+                            "found an empty line after a doc comment. \
+                            Perhaps you need to use `//!` to make a comment on a module, remove the empty line, or make a regular comment with `//`?",
+                            EMPTY_LINE_AFTER_DOC_COMMENTS,
+                        ),
+                        AttrKind::Normal(..) => (
+                            "found an empty line after an outer attribute. \
+                            Perhaps you forgot to add a `!` to make it an inner attribute?",
+                            EMPTY_LINE_AFTER_OUTER_ATTR,
+                        ),
+                    };
+
+                    span_lint(cx, lint_type, begin_of_attr_to_item, lint_msg);
                 }
             }
         }
@@ -690,6 +776,48 @@ fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute, msrv: &Msr
     }
 }
 
+fn check_nested_cfg(cx: &EarlyContext<'_>, items: &[NestedMetaItem]) {
+    for item in items.iter() {
+        if let NestedMetaItem::MetaItem(meta) = item {
+            if !meta.has_name(sym::any) && !meta.has_name(sym::all) {
+                continue;
+            }
+            if let MetaItemKind::List(list) = &meta.kind {
+                check_nested_cfg(cx, list);
+                if list.len() == 1 {
+                    span_lint_and_then(
+                        cx,
+                        NON_MINIMAL_CFG,
+                        meta.span,
+                        "unneeded sub `cfg` when there is only one condition",
+                        |diag| {
+                            if let Some(snippet) = snippet_opt(cx, list[0].span()) {
+                                diag.span_suggestion(meta.span, "try", snippet, Applicability::MaybeIncorrect);
+                            }
+                        },
+                    );
+                } else if list.is_empty() && meta.has_name(sym::all) {
+                    span_lint_and_then(
+                        cx,
+                        NON_MINIMAL_CFG,
+                        meta.span,
+                        "unneeded sub `cfg` when there is no condition",
+                        |_| {},
+                    );
+                }
+            }
+        }
+    }
+}
+
+fn check_minimal_cfg_condition(cx: &EarlyContext<'_>, attr: &Attribute) {
+    if attr.has_name(sym::cfg) &&
+        let Some(items) = attr.meta_item_list()
+    {
+        check_nested_cfg(cx, &items);
+    }
+}
+
 fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) {
     fn find_os(name: &str) -> Option<&'static str> {
         UNIX_SYSTEMS

clippy_lints/src/borrow_deref_ref.rs

@@ -1,5 +1,6 @@
 use crate::reference::DEREF_ADDROF;
 use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::is_from_proc_macro;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::implements_trait;
 use clippy_utils::{get_parent_expr, is_lint_allowed};
@@ -47,8 +48,8 @@ declare_clippy_lint! {
 
 declare_lint_pass!(BorrowDerefRef => [BORROW_DEREF_REF]);
 
-impl LateLintPass<'_> for BorrowDerefRef {
-    fn check_expr(&mut self, cx: &LateContext<'_>, e: &rustc_hir::Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for BorrowDerefRef {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &rustc_hir::Expr<'tcx>) {
         if_chain! {
             if !e.span.from_expansion();
             if let ExprKind::AddrOf(_, Mutability::Not, addrof_target) = e.kind;
@@ -58,6 +59,7 @@ impl LateLintPass<'_> for BorrowDerefRef {
             if !matches!(deref_target.kind, ExprKind::Unary(UnOp::Deref, ..) );
             let ref_ty = cx.typeck_results().expr_ty(deref_target);
             if let ty::Ref(_, inner_ty, Mutability::Not) = ref_ty.kind();
+            if !is_from_proc_macro(cx, e);
             then{
 
                 if let Some(parent_expr) = get_parent_expr(cx, e){

clippy_lints/src/box_default.rs

@@ -8,7 +8,9 @@ use rustc_hir::{
     Block, Expr, ExprKind, Local, Node, QPath, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::{lint::in_external_macro, ty::print::with_forced_trimmed_paths};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::print::with_forced_trimmed_paths;
+use rustc_middle::ty::IsSuggestable;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
 
@@ -49,7 +51,6 @@ impl LateLintPass<'_> for BoxDefault {
             && path_def_id(cx, ty).map_or(false, |id| Some(id) == cx.tcx.lang_items().owned_box())
             && is_default_equivalent(cx, arg)
         {
-            let arg_ty = cx.typeck_results().expr_ty(arg);
             span_lint_and_sugg(
                 cx,
                 BOX_DEFAULT,
@@ -58,8 +59,10 @@ impl LateLintPass<'_> for BoxDefault {
                 "try",
                 if is_plain_default(arg_path) || given_type(cx, expr) {
                     "Box::default()".into()
-                } else {
+                } else if let Some(arg_ty) = cx.typeck_results().expr_ty(arg).make_suggestable(cx.tcx, true) {
                     with_forced_trimmed_paths!(format!("Box::<{arg_ty}>::default()"))
+                } else {
+                    return
                 },
                 Applicability::MachineApplicable
             );

clippy_lints/src/casts/cast_nan_to_int.rs

@@ -21,8 +21,8 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, cast_expr: &Expr<'_>,
 
 fn is_known_nan(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
     match constant(cx, cx.typeck_results(), e) {
-        Some((Constant::F64(n), _)) => n.is_nan(),
-        Some((Constant::F32(n), _)) => n.is_nan(),
+        Some(Constant::F64(n)) => n.is_nan(),
+        Some(Constant::F32(n)) => n.is_nan(),
         _ => false,
     }
 }

clippy_lints/src/casts/cast_possible_truncation.rs

@@ -15,7 +15,7 @@ use rustc_target::abi::IntegerType;
 use super::{utils, CAST_ENUM_TRUNCATION, CAST_POSSIBLE_TRUNCATION};
 
 fn constant_int(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<u128> {
-    if let Some((Constant::Int(c), _)) = constant(cx, cx.typeck_results(), expr) {
+    if let Some(Constant::Int(c)) = constant(cx, cx.typeck_results(), expr) {
         Some(c)
     } else {
         None

clippy_lints/src/casts/cast_sign_loss.rs

@@ -29,7 +29,7 @@ fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast
             // Don't lint for positive constants.
             let const_val = constant(cx, cx.typeck_results(), cast_op);
             if_chain! {
-                if let Some((Constant::Int(n), _)) = const_val;
+                if let Some(Constant::Int(n)) = const_val;
                 if let ty::Int(ity) = *cast_from.kind();
                 if sext(cx.tcx, n, ity) >= 0;
                 then {

clippy_lints/src/dbg_macro.rs

@@ -3,10 +3,10 @@ use clippy_utils::macros::root_macro_call_first_node;
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::{is_in_cfg_test, is_in_test_function};
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind};
-use rustc_lint::{LateContext, LateLintPass};
+use rustc_hir::{Expr, ExprKind, Node};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
-use rustc_span::sym;
+use rustc_span::{sym, BytePos, Pos, Span};
 
 declare_clippy_lint! {
     /// ### What it does
@@ -31,6 +31,31 @@ declare_clippy_lint! {
     "`dbg!` macro is intended as a debugging tool"
 }
 
+/// Gets the span of the statement up to the next semicolon, if and only if the next
+/// non-whitespace character actually is a semicolon.
+/// E.g.
+/// ```rust,ignore
+/// 
+///    dbg!();
+///    ^^^^^^^  this span is returned
+///
+///   foo!(dbg!());
+///             no span is returned
+/// ```
+fn span_including_semi(cx: &LateContext<'_>, span: Span) -> Option<Span> {
+    let sm = cx.sess().source_map();
+    let sf = sm.lookup_source_file(span.hi());
+    let src = sf.src.as_ref()?.get(span.hi().to_usize()..)?;
+    let first_non_whitespace = src.find(|c: char| !c.is_whitespace())?;
+
+    if src.as_bytes()[first_non_whitespace] == b';' {
+        let hi = span.hi() + BytePos::from_usize(first_non_whitespace + 1);
+        Some(span.with_hi(hi))
+    } else {
+        None
+    }
+}
+
 #[derive(Copy, Clone)]
 pub struct DbgMacro {
     allow_dbg_in_tests: bool,
@@ -55,13 +80,25 @@ impl LateLintPass<'_> for DbgMacro {
                 return;
             }
             let mut applicability = Applicability::MachineApplicable;
-            let suggestion = match expr.peel_drop_temps().kind {
+
+            let (sugg_span, suggestion) = match expr.peel_drop_temps().kind {
                 // dbg!()
-                ExprKind::Block(_, _) => String::new(),
-                // dbg!(1)
-                ExprKind::Match(val, ..) => {
-                    snippet_with_applicability(cx, val.span.source_callsite(), "..", &mut applicability).to_string()
+                ExprKind::Block(..) => {
+                    // If the `dbg!` macro is a "free" statement and not contained within other expressions,
+                    // remove the whole statement.
+                    if let Some(Node::Stmt(stmt)) = cx.tcx.hir().find_parent(expr.hir_id)
+                        && let Some(span) = span_including_semi(cx, stmt.span.source_callsite())
+                    {
+                        (span, String::new())
+                    } else {
+                        (macro_call.span, String::from("()"))
+                    }
                 },
+                // dbg!(1)
+                ExprKind::Match(val, ..) => (
+                    macro_call.span,
+                    snippet_with_applicability(cx, val.span.source_callsite(), "..", &mut applicability).to_string(),
+                ),
                 // dbg!(2, 3)
                 ExprKind::Tup(
                     [
@@ -82,7 +119,7 @@ impl LateLintPass<'_> for DbgMacro {
                         "..",
                         &mut applicability,
                     );
-                    format!("({snippet})")
+                    (macro_call.span, format!("({snippet})"))
                 },
                 _ => return,
             };
@@ -90,7 +127,7 @@ impl LateLintPass<'_> for DbgMacro {
             span_lint_and_sugg(
                 cx,
                 DBG_MACRO,
-                macro_call.span,
+                sugg_span,
                 "the `dbg!` macro is intended as a debugging tool",
                 "remove the invocation before committing it to a version control system",
                 suggestion,

clippy_lints/src/declared_lints.rs

@@ -48,9 +48,11 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::attrs::BLANKET_CLIPPY_RESTRICTION_LINTS_INFO,
     crate::attrs::DEPRECATED_CFG_ATTR_INFO,
     crate::attrs::DEPRECATED_SEMVER_INFO,
+    crate::attrs::EMPTY_LINE_AFTER_DOC_COMMENTS_INFO,
     crate::attrs::EMPTY_LINE_AFTER_OUTER_ATTR_INFO,
     crate::attrs::INLINE_ALWAYS_INFO,
     crate::attrs::MISMATCHED_TARGET_OS_INFO,
+    crate::attrs::NON_MINIMAL_CFG_INFO,
     crate::attrs::USELESS_ATTRIBUTE_INFO,
     crate::await_holding_invalid::AWAIT_HOLDING_INVALID_TYPE_INFO,
     crate::await_holding_invalid::AWAIT_HOLDING_LOCK_INFO,
@@ -347,6 +349,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::methods::ITER_WITH_DRAIN_INFO,
     crate::methods::MANUAL_FILTER_MAP_INFO,
     crate::methods::MANUAL_FIND_MAP_INFO,
+    crate::methods::MANUAL_NEXT_BACK_INFO,
     crate::methods::MANUAL_OK_OR_INFO,
     crate::methods::MANUAL_SATURATING_ARITHMETIC_INFO,
     crate::methods::MANUAL_SPLIT_ONCE_INFO,
@@ -485,7 +488,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::operators::FLOAT_EQUALITY_WITHOUT_ABS_INFO,
     crate::operators::IDENTITY_OP_INFO,
     crate::operators::INEFFECTIVE_BIT_MASK_INFO,
-    crate::operators::INTEGER_ARITHMETIC_INFO,
     crate::operators::INTEGER_DIVISION_INFO,
     crate::operators::MISREFACTORED_ASSIGN_OP_INFO,
     crate::operators::MODULO_ARITHMETIC_INFO,
@@ -535,6 +537,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::redundant_slicing::REDUNDANT_SLICING_INFO,
     crate::redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES_INFO,
     crate::ref_option_ref::REF_OPTION_REF_INFO,
+    crate::ref_patterns::REF_PATTERNS_INFO,
     crate::reference::DEREF_ADDROF_INFO,
     crate::regex::INVALID_REGEX_INFO,
     crate::regex::TRIVIAL_REGEX_INFO,

clippy_lints/src/default_constructed_unit_structs.rs

@@ -1,4 +1,4 @@
-use clippy_utils::{diagnostics::span_lint_and_sugg, is_from_proc_macro, match_def_path, paths};
+use clippy_utils::{diagnostics::span_lint_and_sugg, match_def_path, paths};
 use hir::{def::Res, ExprKind};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
@@ -55,7 +55,8 @@ impl LateLintPass<'_> for DefaultConstructedUnitStructs {
             if let ty::Adt(def, ..) = cx.typeck_results().expr_ty(expr).kind();
             if def.is_struct();
             if let var @ ty::VariantDef { ctor: Some((hir::def::CtorKind::Const, _)), .. } = def.non_enum_variant();
-            if !var.is_field_list_non_exhaustive() && !is_from_proc_macro(cx, expr);
+            if !var.is_field_list_non_exhaustive();
+            if !expr.span.from_expansion() && !qpath.span().from_expansion();
             then {
                 span_lint_and_sugg(
                     cx,

clippy_lints/src/floating_point_arithmetic.rs

@@ -114,7 +114,7 @@ declare_lint_pass!(FloatingPointArithmetic => [
 // Returns the specialized log method for a given base if base is constant
 // and is one of 2, 10 and e
 fn get_specialized_log_method(cx: &LateContext<'_>, base: &Expr<'_>) -> Option<&'static str> {
-    if let Some((value, _)) = constant(cx, cx.typeck_results(), base) {
+    if let Some(value) = constant(cx, cx.typeck_results(), base) {
         if F32(2.0) == value || F64(2.0) == value {
             return Some("log2");
         } else if F32(10.0) == value || F64(10.0) == value {
@@ -193,8 +193,8 @@ fn check_ln1p(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>) {
             constant(cx, cx.typeck_results(), lhs),
             constant(cx, cx.typeck_results(), rhs),
         ) {
-            (Some((value, _)), _) if F32(1.0) == value || F64(1.0) == value => rhs,
-            (_, Some((value, _))) if F32(1.0) == value || F64(1.0) == value => lhs,
+            (Some(value), _) if F32(1.0) == value || F64(1.0) == value => rhs,
+            (_, Some(value)) if F32(1.0) == value || F64(1.0) == value => lhs,
             _ => return,
         };
 
@@ -237,7 +237,7 @@ fn get_integer_from_float_constant(value: &Constant) -> Option<i32> {
 
 fn check_powf(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>, args: &[Expr<'_>]) {
     // Check receiver
-    if let Some((value, _)) = constant(cx, cx.typeck_results(), receiver) {
+    if let Some(value) = constant(cx, cx.typeck_results(), receiver) {
         if let Some(method) = if F32(f32_consts::E) == value || F64(f64_consts::E) == value {
             Some("exp")
         } else if F32(2.0) == value || F64(2.0) == value {
@@ -258,7 +258,7 @@ fn check_powf(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>, args:
     }
 
     // Check argument
-    if let Some((value, _)) = constant(cx, cx.typeck_results(), &args[0]) {
+    if let Some(value) = constant(cx, cx.typeck_results(), &args[0]) {
         let (lint, help, suggestion) = if F32(1.0 / 2.0) == value || F64(1.0 / 2.0) == value {
             (
                 SUBOPTIMAL_FLOPS,
@@ -298,7 +298,7 @@ fn check_powf(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>, args:
 }
 
 fn check_powi(cx: &LateContext<'_>, expr: &Expr<'_>, receiver: &Expr<'_>, args: &[Expr<'_>]) {
-    if let Some((value, _)) = constant(cx, cx.typeck_results(), &args[0]) {
+    if let Some(value) = constant(cx, cx.typeck_results(), &args[0]) {
         if value == Int(2) {
             if let Some(parent) = get_parent_expr(cx, expr) {
                 if let Some(grandparent) = get_parent_expr(cx, parent) {
@@ -384,8 +384,8 @@ fn detect_hypot(cx: &LateContext<'_>, receiver: &Expr<'_>) -> Option<String> {
                 _
             ) = &add_rhs.kind;
             if lmethod_name.as_str() == "powi" && rmethod_name.as_str() == "powi";
-            if let Some((lvalue, _)) = constant(cx, cx.typeck_results(), largs_1);
-            if let Some((rvalue, _)) = constant(cx, cx.typeck_results(), rargs_1);
+            if let Some(lvalue) = constant(cx, cx.typeck_results(), largs_1);
+            if let Some(rvalue) = constant(cx, cx.typeck_results(), rargs_1);
             if Int(2) == lvalue && Int(2) == rvalue;
             then {
                 return Some(format!("{}.hypot({})", Sugg::hir(cx, largs_0, "..").maybe_par(), Sugg::hir(cx, rargs_0, "..")));
@@ -416,7 +416,7 @@ fn check_expm1(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if_chain! {
         if let ExprKind::Binary(Spanned { node: BinOpKind::Sub, .. }, lhs, rhs) = expr.kind;
         if cx.typeck_results().expr_ty(lhs).is_floating_point();
-        if let Some((value, _)) = constant(cx, cx.typeck_results(), rhs);
+        if let Some(value) = constant(cx, cx.typeck_results(), rhs);
         if F32(1.0) == value || F64(1.0) == value;
         if let ExprKind::MethodCall(path, self_arg, ..) = &lhs.kind;
         if cx.typeck_results().expr_ty(self_arg).is_floating_point();
@@ -669,8 +669,8 @@ fn check_radians(cx: &LateContext<'_>, expr: &Expr<'_>) {
             mul_lhs,
             mul_rhs,
         ) = &div_lhs.kind;
-        if let Some((rvalue, _)) = constant(cx, cx.typeck_results(), div_rhs);
-        if let Some((lvalue, _)) = constant(cx, cx.typeck_results(), mul_rhs);
+        if let Some(rvalue) = constant(cx, cx.typeck_results(), div_rhs);
+        if let Some(lvalue) = constant(cx, cx.typeck_results(), mul_rhs);
         then {
             // TODO: also check for constant values near PI/180 or 180/PI
             if (F32(f32_consts::PI) == rvalue || F64(f64_consts::PI) == rvalue) &&

clippy_lints/src/fn_null_check.rs

@@ -89,11 +89,7 @@ impl<'tcx> LateLintPass<'tcx> for FnNullCheck {
 
                     // Catching:
                     // (fn_ptr as *<const/mut> <ty>) == <const that evaluates to null_ptr>
-                    _ if matches!(
-                        constant(cx, cx.typeck_results(), to_check),
-                        Some((Constant::RawPtr(0), _))
-                    ) =>
-                    {
+                    _ if matches!(constant(cx, cx.typeck_results(), to_check), Some(Constant::RawPtr(0))) => {
                         lint_expr(cx, expr);
                     },
 

clippy_lints/src/implicit_saturating_add.rs

@@ -101,10 +101,10 @@ fn get_int_max(ty: Ty<'_>) -> Option<u128> {
 fn get_const<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>) -> Option<(u128, BinOpKind, &'tcx Expr<'tcx>)> {
     if let ExprKind::Binary(op, l, r) = expr.kind {
         let tr = cx.typeck_results();
-        if let Some((Constant::Int(c), _)) = constant(cx, tr, r) {
+        if let Some(Constant::Int(c)) = constant(cx, tr, r) {
             return Some((c, op.node, l));
         };
-        if let Some((Constant::Int(c), _)) = constant(cx, tr, l) {
+        if let Some(Constant::Int(c)) = constant(cx, tr, l) {
             return Some((c, invert_op(op.node)?, r));
         }
     }

clippy_lints/src/index_refutable_slice.rs

@@ -254,7 +254,7 @@ impl<'a, 'tcx> Visitor<'tcx> for SliceIndexLintingVisitor<'a, 'tcx> {
                 let parent_id = map.parent_id(expr.hir_id);
                 if let Some(hir::Node::Expr(parent_expr)) = map.find(parent_id);
                 if let hir::ExprKind::Index(_, index_expr) = parent_expr.kind;
-                if let Some((Constant::Int(index_value), _)) = constant(cx, cx.typeck_results(), index_expr);
+                if let Some(Constant::Int(index_value)) = constant(cx, cx.typeck_results(), index_expr);
                 if let Ok(index_value) = index_value.try_into();
                 if index_value < max_suggested_slice;
 

clippy_lints/src/indexing_slicing.rs

@@ -191,18 +191,14 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
 /// Returns a tuple of options with the start and end (exclusive) values of
 /// the range. If the start or end is not constant, None is returned.
 fn to_const_range(cx: &LateContext<'_>, range: higher::Range<'_>, array_size: u128) -> (Option<u128>, Option<u128>) {
-    let s = range
-        .start
-        .map(|expr| constant(cx, cx.typeck_results(), expr).map(|(c, _)| c));
+    let s = range.start.map(|expr| constant(cx, cx.typeck_results(), expr));
     let start = match s {
         Some(Some(Constant::Int(x))) => Some(x),
         Some(_) => None,
         None => Some(0),
     };
 
-    let e = range
-        .end
-        .map(|expr| constant(cx, cx.typeck_results(), expr).map(|(c, _)| c));
+    let e = range.end.map(|expr| constant(cx, cx.typeck_results(), expr));
     let end = match e {
         Some(Some(Constant::Int(x))) => {
             if range.limits == RangeLimits::Closed {

clippy_lints/src/let_underscore.rs

@@ -1,10 +1,12 @@
 use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::is_from_proc_macro;
 use clippy_utils::ty::{implements_trait, is_must_use_ty, match_type};
 use clippy_utils::{is_must_use_func_call, paths};
-use rustc_hir::{ExprKind, Local, PatKind};
+use rustc_hir::{Local, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::subst::GenericArgKind;
+use rustc_middle::ty::IsSuggestable;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{BytePos, Span};
 
@@ -138,7 +140,7 @@ const SYNC_GUARD_PATHS: [&[&str]; 3] = [
 ];
 
 impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
-    fn check_local(&mut self, cx: &LateContext<'_>, local: &Local<'_>) {
+    fn check_local(&mut self, cx: &LateContext<'tcx>, local: &Local<'tcx>) {
         if !in_external_macro(cx.tcx.sess, local.span)
             && let PatKind::Wild = local.pat.kind
             && let Some(init) = local.init
@@ -191,15 +193,17 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
             if local.pat.default_binding_modes && local.ty.is_none() {
                 // When `default_binding_modes` is true, the `let` keyword is present.
 
-				// Ignore function calls that return impl traits...
-				if let Some(init) = local.init &&
-				matches!(init.kind, ExprKind::Call(_, _) | ExprKind::MethodCall(_, _, _, _)) {
-					let expr_ty = cx.typeck_results().expr_ty(init);
-					if expr_ty.is_impl_trait() {
-						return;
-					}
-				}
+                // Ignore unnameable types
+                if let Some(init) = local.init
+                    && !cx.typeck_results().expr_ty(init).is_suggestable(cx.tcx, true)
+                {
+                    return;
+                }
 
+                // Ignore if it is from a procedural macro...
+                if is_from_proc_macro(cx, init) {
+                    return;
+                }
 
 				span_lint_and_help(
                     cx,

clippy_lints/src/lib.rs

@@ -266,6 +266,7 @@ mod redundant_pub_crate;
 mod redundant_slicing;
 mod redundant_static_lifetimes;
 mod ref_option_ref;
+mod ref_patterns;
 mod reference;
 mod regex;
 mod return_self_not_must_use;
@@ -331,8 +332,11 @@ mod zero_div_zero;
 mod zero_sized_map_values;
 // end lints modules, do not remove this comment, it’s used in `update_lints`
 
-use crate::utils::conf::{format_error, TryConf};
 pub use crate::utils::conf::{lookup_conf_file, Conf};
+use crate::utils::{
+    conf::{format_error, metadata::get_configuration_metadata, TryConf},
+    FindAll,
+};
 
 /// Register all pre expansion lints
 ///
@@ -471,7 +475,22 @@ pub(crate) struct LintInfo {
 pub fn explain(name: &str) {
     let target = format!("clippy::{}", name.to_ascii_uppercase());
     match declared_lints::LINTS.iter().find(|info| info.lint.name == target) {
-        Some(info) => print!("{}", info.explanation),
+        Some(info) => {
+            println!("{}", info.explanation);
+            // Check if the lint has configuration
+            let mdconf = get_configuration_metadata();
+            if let Some(config_vec_positions) = mdconf
+                .iter()
+                .find_all(|cconf| cconf.lints.contains(&info.lint.name_lower()[8..].to_owned()))
+            {
+                // If it has, print it
+                println!("### Configuration for {}:\n", info.lint.name_lower());
+                for position in config_vec_positions {
+                    let conf = &mdconf[position];
+                    println!("  - {}: {} (default: {})", conf.name, conf.doc, conf.default);
+                }
+            }
+        },
         None => println!("unknown lint: {name}"),
     }
 }
@@ -971,6 +990,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(manual_slice_size_calculation::ManualSliceSizeCalculation));
     store.register_early_pass(|| Box::new(suspicious_doc_comments::SuspiciousDocComments));
     store.register_late_pass(|_| Box::new(items_after_test_module::ItemsAfterTestModule));
+    store.register_early_pass(|| Box::new(ref_patterns::RefPatterns));
     store.register_late_pass(|_| Box::new(default_constructed_unit_structs::DefaultConstructedUnitStructs));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }

clippy_lints/src/lines_filter_map_ok.rs

@@ -25,7 +25,7 @@ declare_clippy_lint! {
     ///
     /// ### Known problems
     /// This lint suggests replacing `filter_map()` or `flat_map()` applied to a `Lines`
-    /// instance in all cases. There two cases where the suggestion might not be
+    /// instance in all cases. There are two cases where the suggestion might not be
     /// appropriate or necessary:
     ///
     /// - If the `Lines` instance can never produce any error, or if an error is produced

clippy_lints/src/manual_let_else.rs

@@ -38,7 +38,6 @@ declare_clippy_lint! {
     /// Could be written:
     ///
     /// ```rust
-    /// # #![feature(let_else)]
     /// # fn main () {
     /// # let w = Some(0);
     /// let Some(v) = w else { return };
@@ -69,29 +68,23 @@ impl_lint_pass!(ManualLetElse => [MANUAL_LET_ELSE]);
 
 impl<'tcx> LateLintPass<'tcx> for ManualLetElse {
     fn check_stmt(&mut self, cx: &LateContext<'_>, stmt: &'tcx Stmt<'tcx>) {
-        let if_let_or_match = if_chain! {
-            if self.msrv.meets(msrvs::LET_ELSE);
-            if !in_external_macro(cx.sess(), stmt.span);
-            if let StmtKind::Local(local) = stmt.kind;
-            if let Some(init) = local.init;
-            if local.els.is_none();
-            if local.ty.is_none();
-            if init.span.ctxt() == stmt.span.ctxt();
-            if let Some(if_let_or_match) = IfLetOrMatch::parse(cx, init);
-            then {
-                if_let_or_match
-            } else {
-                return;
-            }
-        };
+        if !self.msrv.meets(msrvs::LET_ELSE) || in_external_macro(cx.sess(), stmt.span) {
+            return;
+        }
 
+        if let StmtKind::Local(local) = stmt.kind &&
+            let Some(init) = local.init &&
+            local.els.is_none() &&
+            local.ty.is_none() &&
+            init.span.ctxt() == stmt.span.ctxt() &&
+            let Some(if_let_or_match) = IfLetOrMatch::parse(cx, init) {
         match if_let_or_match {
             IfLetOrMatch::IfLet(if_let_expr, let_pat, if_then, if_else) => if_chain! {
                 if expr_is_simple_identity(let_pat, if_then);
                 if let Some(if_else) = if_else;
                 if expr_diverges(cx, if_else);
                 then {
-                    emit_manual_let_else(cx, stmt.span, if_let_expr, let_pat, if_else);
+                    emit_manual_let_else(cx, stmt.span, if_let_expr, local.pat, let_pat, if_else);
                 }
             },
             IfLetOrMatch::Match(match_expr, arms, source) => {
@@ -128,15 +121,23 @@ impl<'tcx> LateLintPass<'tcx> for ManualLetElse {
                     return;
                 }
 
-                emit_manual_let_else(cx, stmt.span, match_expr, pat_arm.pat, diverging_arm.body);
+                emit_manual_let_else(cx, stmt.span, match_expr, local.pat, pat_arm.pat, diverging_arm.body);
             },
         }
+        };
     }
 
     extract_msrv_attr!(LateContext);
 }
 
-fn emit_manual_let_else(cx: &LateContext<'_>, span: Span, expr: &Expr<'_>, pat: &Pat<'_>, else_body: &Expr<'_>) {
+fn emit_manual_let_else(
+    cx: &LateContext<'_>,
+    span: Span,
+    expr: &Expr<'_>,
+    local: &Pat<'_>,
+    pat: &Pat<'_>,
+    else_body: &Expr<'_>,
+) {
     span_lint_and_then(
         cx,
         MANUAL_LET_ELSE,
@@ -145,12 +146,11 @@ fn emit_manual_let_else(cx: &LateContext<'_>, span: Span, expr: &Expr<'_>, pat:
         |diag| {
             // This is far from perfect, for example there needs to be:
             // * mut additions for the bindings
-            // * renamings of the bindings
+            // * renamings of the bindings for `PatKind::Or`
             // * unused binding collision detection with existing ones
             // * putting patterns with at the top level | inside ()
             // for this to be machine applicable.
             let mut app = Applicability::HasPlaceholders;
-            let (sn_pat, _) = snippet_with_context(cx, pat.span, span.ctxt(), "", &mut app);
             let (sn_expr, _) = snippet_with_context(cx, expr.span, span.ctxt(), "", &mut app);
             let (sn_else, _) = snippet_with_context(cx, else_body.span, span.ctxt(), "", &mut app);
 
@@ -159,10 +159,21 @@ fn emit_manual_let_else(cx: &LateContext<'_>, span: Span, expr: &Expr<'_>, pat:
             } else {
                 format!("{{ {sn_else} }}")
             };
-            let sn_bl = if matches!(pat.kind, PatKind::Or(..)) {
-                format!("({sn_pat})")
-            } else {
-                sn_pat.into_owned()
+            let sn_bl = match pat.kind {
+                PatKind::Or(..) => {
+                    let (sn_pat, _) = snippet_with_context(cx, pat.span, span.ctxt(), "", &mut app);
+                    format!("({sn_pat})")
+                },
+                // Replace the variable name iff `TupleStruct` has one argument like `Variant(v)`.
+                PatKind::TupleStruct(ref w, args, ..) if args.len() == 1 => {
+                    let sn_wrapper = cx.sess().source_map().span_to_snippet(w.span()).unwrap_or_default();
+                    let (sn_inner, _) = snippet_with_context(cx, local.span, span.ctxt(), "", &mut app);
+                    format!("{sn_wrapper}({sn_inner})")
+                },
+                _ => {
+                    let (sn_pat, _) = snippet_with_context(cx, pat.span, span.ctxt(), "", &mut app);
+                    sn_pat.into_owned()
+                },
             };
             let sugg = format!("let {sn_bl} = {sn_expr} else {else_bl};");
             diag.span_suggestion(span, "consider writing", sugg, app);

clippy_lints/src/manual_strip.rs

@@ -144,7 +144,7 @@ fn len_arg<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx E
 
 // Returns the length of the `expr` if it's a constant string or char.
 fn constant_length(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<u128> {
-    let (value, _) = constant(cx, cx.typeck_results(), expr)?;
+    let value = constant(cx, cx.typeck_results(), expr)?;
     match value {
         Constant::Str(value) => Some(value.len() as u128),
         Constant::Char(value) => Some(value.len_utf8() as u128),

clippy_lints/src/matches/match_like_matches.rs

@@ -1,10 +1,12 @@
+use super::REDUNDANT_PATTERN_MATCHING;
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_lint_allowed;
 use clippy_utils::is_wild;
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::span_contains_comment;
 use rustc_ast::{Attribute, LitKind};
 use rustc_errors::Applicability;
-use rustc_hir::{Arm, BorrowKind, Expr, ExprKind, Guard, Pat};
+use rustc_hir::{Arm, BorrowKind, Expr, ExprKind, Guard, Pat, PatKind, QPath};
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::ty;
 use rustc_span::source_map::Spanned;
@@ -99,6 +101,14 @@ where
                 }
             }
 
+            for arm in iter_without_last.clone() {
+                if let Some(pat) = arm.1 {
+                    if !is_lint_allowed(cx, REDUNDANT_PATTERN_MATCHING, pat.hir_id) && is_some(pat.kind) {
+                        return false;
+                    }
+                }
+            }
+
             // The suggestion may be incorrect, because some arms can have `cfg` attributes
             // evaluated into `false` and so such arms will be stripped before.
             let mut applicability = Applicability::MaybeIncorrect;
@@ -170,3 +180,13 @@ fn find_bool_lit(ex: &ExprKind<'_>) -> Option<bool> {
         _ => None,
     }
 }
+
+fn is_some(path_kind: PatKind<'_>) -> bool {
+    match path_kind {
+        PatKind::TupleStruct(QPath::Resolved(_, path), [first, ..], _) if is_wild(first) => {
+            let name = path.segments[0].ident;
+            name.name == rustc_span::sym::Some
+        },
+        _ => false,
+    }
+}

clippy_lints/src/matches/match_same_arms.rs

@@ -282,9 +282,8 @@ impl<'a> NormalizedPat<'a> {
                 // TODO: Handle negative integers. They're currently treated as a wild match.
                 ExprKind::Lit(lit) => match lit.node {
                     LitKind::Str(sym, _) => Self::LitStr(sym),
-                    LitKind::ByteStr(ref bytes, _) => Self::LitBytes(bytes),
+                    LitKind::ByteStr(ref bytes, _) | LitKind::CStr(ref bytes, _) => Self::LitBytes(bytes),
                     LitKind::Byte(val) => Self::LitInt(val.into()),
-                    LitKind::CStr(ref bytes, _) => Self::LitBytes(bytes),
                     LitKind::Char(val) => Self::LitInt(val.into()),
                     LitKind::Int(val, _) => Self::LitInt(val),
                     LitKind::Bool(val) => Self::LitBool(val),

clippy_lints/src/matches/mod.rs

@@ -25,9 +25,9 @@ mod wild_in_or_pats;
 
 use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::{snippet_opt, walk_span_to_context};
-use clippy_utils::{higher, in_constant, is_span_match};
+use clippy_utils::{higher, in_constant, is_span_match, tokenize_with_text};
 use rustc_hir::{Arm, Expr, ExprKind, Local, MatchSource, Pat};
-use rustc_lexer::{tokenize, TokenKind};
+use rustc_lexer::TokenKind;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
@@ -1147,12 +1147,7 @@ fn span_contains_cfg(cx: &LateContext<'_>, s: Span) -> bool {
         // Assume true. This would require either an invalid span, or one which crosses file boundaries.
         return true;
     };
-    let mut pos = 0usize;
-    let mut iter = tokenize(&snip).map(|t| {
-        let start = pos;
-        pos += t.len as usize;
-        (t.kind, start..pos)
-    });
+    let mut iter = tokenize_with_text(&snip);
 
     // Search for the token sequence [`#`, `[`, `cfg`]
     while iter.any(|(t, _)| matches!(t, TokenKind::Pound)) {
@@ -1163,7 +1158,7 @@ fn span_contains_cfg(cx: &LateContext<'_>, s: Span) -> bool {
             )
         });
         if matches!(iter.next(), Some((TokenKind::OpenBracket, _)))
-            && matches!(iter.next(), Some((TokenKind::Ident, range)) if &snip[range.clone()] == "cfg")
+            && matches!(iter.next(), Some((TokenKind::Ident, "cfg")))
         {
             return true;
         }

clippy_lints/src/matches/overlapping_arms.rs

@@ -34,7 +34,7 @@ fn all_ranges<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>], ty: Ty<'tcx>)
             if let Arm { pat, guard: None, .. } = *arm {
                 if let PatKind::Range(ref lhs, ref rhs, range_end) = pat.kind {
                     let lhs_const = match lhs {
-                        Some(lhs) => constant(cx, cx.typeck_results(), lhs)?.0,
+                        Some(lhs) => constant(cx, cx.typeck_results(), lhs)?,
                         None => {
                             let min_val_const = ty.numeric_min_val(cx.tcx)?;
                             let min_constant = mir::ConstantKind::from_value(
@@ -45,7 +45,7 @@ fn all_ranges<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>], ty: Ty<'tcx>)
                         },
                     };
                     let rhs_const = match rhs {
-                        Some(rhs) => constant(cx, cx.typeck_results(), rhs)?.0,
+                        Some(rhs) => constant(cx, cx.typeck_results(), rhs)?,
                         None => {
                             let max_val_const = ty.numeric_max_val(cx.tcx)?;
                             let max_constant = mir::ConstantKind::from_value(

clippy_lints/src/matches/redundant_pattern_match.rs

@@ -189,73 +189,7 @@ pub(super) fn check_match<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, op
     if arms.len() == 2 {
         let node_pair = (&arms[0].pat.kind, &arms[1].pat.kind);
 
-        let found_good_method = match node_pair {
-            (
-                PatKind::TupleStruct(ref path_left, patterns_left, _),
-                PatKind::TupleStruct(ref path_right, patterns_right, _),
-            ) if patterns_left.len() == 1 && patterns_right.len() == 1 => {
-                if let (PatKind::Wild, PatKind::Wild) = (&patterns_left[0].kind, &patterns_right[0].kind) {
-                    find_good_method_for_match(
-                        cx,
-                        arms,
-                        path_left,
-                        path_right,
-                        Item::Lang(ResultOk),
-                        Item::Lang(ResultErr),
-                        "is_ok()",
-                        "is_err()",
-                    )
-                    .or_else(|| {
-                        find_good_method_for_match(
-                            cx,
-                            arms,
-                            path_left,
-                            path_right,
-                            Item::Diag(sym::IpAddr, sym!(V4)),
-                            Item::Diag(sym::IpAddr, sym!(V6)),
-                            "is_ipv4()",
-                            "is_ipv6()",
-                        )
-                    })
-                } else {
-                    None
-                }
-            },
-            (PatKind::TupleStruct(ref path_left, patterns, _), PatKind::Path(ref path_right))
-            | (PatKind::Path(ref path_left), PatKind::TupleStruct(ref path_right, patterns, _))
-                if patterns.len() == 1 =>
-            {
-                if let PatKind::Wild = patterns[0].kind {
-                    find_good_method_for_match(
-                        cx,
-                        arms,
-                        path_left,
-                        path_right,
-                        Item::Lang(OptionSome),
-                        Item::Lang(OptionNone),
-                        "is_some()",
-                        "is_none()",
-                    )
-                    .or_else(|| {
-                        find_good_method_for_match(
-                            cx,
-                            arms,
-                            path_left,
-                            path_right,
-                            Item::Lang(PollReady),
-                            Item::Lang(PollPending),
-                            "is_ready()",
-                            "is_pending()",
-                        )
-                    })
-                } else {
-                    None
-                }
-            },
-            _ => None,
-        };
-
-        if let Some(good_method) = found_good_method {
+        if let Some(good_method) = found_good_method(cx, arms, node_pair) {
             let span = expr.span.to(op.span);
             let result_expr = match &op.kind {
                 ExprKind::AddrOf(_, _, borrowed) => borrowed,
@@ -279,6 +213,127 @@ pub(super) fn check_match<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, op
     }
 }
 
+fn found_good_method<'a>(
+    cx: &LateContext<'_>,
+    arms: &[Arm<'_>],
+    node: (&PatKind<'_>, &PatKind<'_>),
+) -> Option<&'a str> {
+    match node {
+        (
+            PatKind::TupleStruct(ref path_left, patterns_left, _),
+            PatKind::TupleStruct(ref path_right, patterns_right, _),
+        ) if patterns_left.len() == 1 && patterns_right.len() == 1 => {
+            if let (PatKind::Wild, PatKind::Wild) = (&patterns_left[0].kind, &patterns_right[0].kind) {
+                find_good_method_for_match(
+                    cx,
+                    arms,
+                    path_left,
+                    path_right,
+                    Item::Lang(ResultOk),
+                    Item::Lang(ResultErr),
+                    "is_ok()",
+                    "is_err()",
+                )
+                .or_else(|| {
+                    find_good_method_for_match(
+                        cx,
+                        arms,
+                        path_left,
+                        path_right,
+                        Item::Diag(sym::IpAddr, sym!(V4)),
+                        Item::Diag(sym::IpAddr, sym!(V6)),
+                        "is_ipv4()",
+                        "is_ipv6()",
+                    )
+                })
+            } else {
+                None
+            }
+        },
+        (PatKind::TupleStruct(ref path_left, patterns, _), PatKind::Path(ref path_right))
+        | (PatKind::Path(ref path_left), PatKind::TupleStruct(ref path_right, patterns, _))
+            if patterns.len() == 1 =>
+        {
+            if let PatKind::Wild = patterns[0].kind {
+                find_good_method_for_match(
+                    cx,
+                    arms,
+                    path_left,
+                    path_right,
+                    Item::Lang(OptionSome),
+                    Item::Lang(OptionNone),
+                    "is_some()",
+                    "is_none()",
+                )
+                .or_else(|| {
+                    find_good_method_for_match(
+                        cx,
+                        arms,
+                        path_left,
+                        path_right,
+                        Item::Lang(PollReady),
+                        Item::Lang(PollPending),
+                        "is_ready()",
+                        "is_pending()",
+                    )
+                })
+            } else {
+                None
+            }
+        },
+        (PatKind::TupleStruct(ref path_left, patterns, _), PatKind::Wild) if patterns.len() == 1 => {
+            if let PatKind::Wild = patterns[0].kind {
+                get_good_method(cx, arms, path_left)
+            } else {
+                None
+            }
+        },
+        (PatKind::Path(ref path_left), PatKind::Wild) => get_good_method(cx, arms, path_left),
+        _ => None,
+    }
+}
+
+fn get_ident(path: &QPath<'_>) -> Option<rustc_span::symbol::Ident> {
+    match path {
+        QPath::Resolved(_, path) => {
+            let name = path.segments[0].ident;
+            Some(name)
+        },
+        _ => None,
+    }
+}
+
+fn get_good_method<'a>(cx: &LateContext<'_>, arms: &[Arm<'_>], path_left: &QPath<'_>) -> Option<&'a str> {
+    if let Some(name) = get_ident(path_left) {
+        return match name.as_str() {
+            "Ok" => {
+                find_good_method_for_matches_macro(cx, arms, path_left, Item::Lang(ResultOk), "is_ok()", "is_err()")
+            },
+            "Err" => {
+                find_good_method_for_matches_macro(cx, arms, path_left, Item::Lang(ResultErr), "is_err()", "is_ok()")
+            },
+            "Some" => find_good_method_for_matches_macro(
+                cx,
+                arms,
+                path_left,
+                Item::Lang(OptionSome),
+                "is_some()",
+                "is_none()",
+            ),
+            "None" => find_good_method_for_matches_macro(
+                cx,
+                arms,
+                path_left,
+                Item::Lang(OptionNone),
+                "is_none()",
+                "is_some()",
+            ),
+            _ => None,
+        };
+    }
+    None
+}
+
 #[derive(Clone, Copy)]
 enum Item {
     Lang(LangItem),
@@ -346,3 +401,29 @@ fn find_good_method_for_match<'a>(
         _ => None,
     }
 }
+
+fn find_good_method_for_matches_macro<'a>(
+    cx: &LateContext<'_>,
+    arms: &[Arm<'_>],
+    path_left: &QPath<'_>,
+    expected_item_left: Item,
+    should_be_left: &'a str,
+    should_be_right: &'a str,
+) -> Option<&'a str> {
+    let first_pat = arms[0].pat;
+
+    let body_node_pair = if is_pat_variant(cx, first_pat, path_left, expected_item_left) {
+        (&arms[0].body.kind, &arms[1].body.kind)
+    } else {
+        return None;
+    };
+
+    match body_node_pair {
+        (ExprKind::Lit(lit_left), ExprKind::Lit(lit_right)) => match (&lit_left.node, &lit_right.node) {
+            (LitKind::Bool(true), LitKind::Bool(false)) => Some(should_be_left),
+            (LitKind::Bool(false), LitKind::Bool(true)) => Some(should_be_right),
+            _ => None,
+        },
+        _ => None,
+    }
+}

clippy_lints/src/methods/iter_nth_zero.rs

@@ -13,7 +13,7 @@ use super::ITER_NTH_ZERO;
 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
     if_chain! {
         if is_trait_method(cx, expr, sym::Iterator);
-        if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), arg);
+        if let Some(Constant::Int(0)) = constant(cx, cx.typeck_results(), arg);
         then {
             let mut applicability = Applicability::MachineApplicable;
             span_lint_and_sugg(

clippy_lints/src/methods/iterator_step_by_zero.rs

@@ -9,7 +9,7 @@ use super::ITERATOR_STEP_BY_ZERO;
 
 pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, arg: &'tcx hir::Expr<'_>) {
     if is_trait_method(cx, expr, sym::Iterator) {
-        if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), arg) {
+        if let Some(Constant::Int(0)) = constant(cx, cx.typeck_results(), arg) {
             span_lint(
                 cx,
                 ITERATOR_STEP_BY_ZERO,

clippy_lints/src/methods/manual_next_back.rs

@@ -0,0 +1,38 @@
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_trait_method;
+use clippy_utils::ty::implements_trait;
+use rustc_errors::Applicability;
+use rustc_hir::Expr;
+use rustc_lint::LateContext;
+use rustc_span::symbol::sym;
+
+pub(super) fn check<'tcx>(
+    cx: &LateContext<'tcx>,
+    expr: &'tcx Expr<'_>,
+    rev_call: &'tcx Expr<'_>,
+    rev_recv: &'tcx Expr<'_>,
+) {
+    let rev_recv_ty = cx.typeck_results().expr_ty(rev_recv);
+
+    // check that the receiver of `rev` implements `DoubleEndedIterator` and
+    // that `rev` and `next` come from `Iterator`
+    if cx
+        .tcx
+        .get_diagnostic_item(sym::DoubleEndedIterator)
+        .map_or(false, |double_ended_iterator| {
+            implements_trait(cx, rev_recv_ty, double_ended_iterator, &[])
+        })
+        && is_trait_method(cx, rev_call, sym::Iterator)
+        && is_trait_method(cx, expr, sym::Iterator)
+    {
+        span_lint_and_sugg(
+            cx,
+            super::MANUAL_NEXT_BACK,
+            expr.span.with_lo(rev_recv.span.hi()),
+            "manual backwards iteration",
+            "use",
+            String::from(".next_back()"),
+            Applicability::MachineApplicable,
+        );
+    }
+}

clippy_lints/src/methods/mod.rs

@@ -45,6 +45,7 @@ mod iter_overeager_cloned;
 mod iter_skip_next;
 mod iter_with_drain;
 mod iterator_step_by_zero;
+mod manual_next_back;
 mod manual_ok_or;
 mod manual_saturating_arithmetic;
 mod manual_str_repeat;
@@ -3132,8 +3133,11 @@ declare_clippy_lint! {
     /// ### Example
     /// ```rust
     /// # let iterator = vec![1].into_iter();
-    /// let len = iterator.clone().collect::<Vec<_>>().len();
-    /// // should be
+    /// let len = iterator.collect::<Vec<_>>().len();
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// # let iterator = vec![1].into_iter();
     /// let len = iterator.count();
     /// ```
     #[clippy::version = "1.30.0"]
@@ -3193,6 +3197,29 @@ declare_clippy_lint! {
     "calling `drain` in order to `clear` a container"
 }
 
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for `.rev().next()` on a `DoubleEndedIterator`
+    ///
+    /// ### Why is this bad?
+    /// `.next_back()` is cleaner.
+    ///
+    /// ### Example
+    /// ```rust
+    /// # let foo = [0; 10];
+    /// foo.iter().rev().next();
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// # let foo = [0; 10];
+    /// foo.iter().next_back();
+    /// ```
+    #[clippy::version = "1.71.0"]
+    pub MANUAL_NEXT_BACK,
+    style,
+    "manual reverse iteration of `DoubleEndedIterator`"
+}
+
 pub struct Methods {
     avoid_breaking_exported_api: bool,
     msrv: Msrv,
@@ -3321,6 +3348,7 @@ impl_lint_pass!(Methods => [
     NEEDLESS_COLLECT,
     SUSPICIOUS_COMMAND_ARG_SPACE,
     CLEAR_WITH_DRAIN,
+    MANUAL_NEXT_BACK,
 ]);
 
 /// Extracts a method call name, args, and `Span` of the method name.
@@ -3677,6 +3705,7 @@ impl Methods {
                             ("iter", []) => iter_next_slice::check(cx, expr, recv2),
                             ("skip", [arg]) => iter_skip_next::check(cx, expr, recv2, arg),
                             ("skip_while", [_]) => skip_while_next::check(cx, expr),
+                            ("rev", [])=> manual_next_back::check(cx, expr, recv, recv2),
                             _ => {},
                         }
                     }
@@ -3741,13 +3770,13 @@ impl Methods {
                     unnecessary_sort_by::check(cx, expr, recv, arg, true);
                 },
                 ("splitn" | "rsplitn", [count_arg, pat_arg]) => {
-                    if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
+                    if let Some(Constant::Int(count)) = constant(cx, cx.typeck_results(), count_arg) {
                         suspicious_splitn::check(cx, name, expr, recv, count);
                         str_splitn::check(cx, name, expr, recv, pat_arg, count, &self.msrv);
                     }
                 },
                 ("splitn_mut" | "rsplitn_mut", [count_arg, _]) => {
-                    if let Some((Constant::Int(count), _)) = constant(cx, cx.typeck_results(), count_arg) {
+                    if let Some(Constant::Int(count)) = constant(cx, cx.typeck_results(), count_arg) {
                         suspicious_splitn::check(cx, name, expr, recv, count);
                     }
                 },

clippy_lints/src/methods/needless_collect.rs

@@ -1,6 +1,5 @@
 use super::NEEDLESS_COLLECT;
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then};
-use clippy_utils::higher;
 use clippy_utils::source::{snippet, snippet_with_applicability};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::{is_type_diagnostic_item, make_normalized_projection, make_projection};
@@ -8,6 +7,7 @@ use clippy_utils::{
     can_move_expr_to_closure, get_enclosing_block, get_parent_node, is_trait_method, path_to_local, path_to_local_id,
     CaptureKind,
 };
+use clippy_utils::{fn_def_id, higher};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, MultiSpan};
 use rustc_hir::intravisit::{walk_block, walk_expr, Visitor};
@@ -16,7 +16,7 @@ use rustc_hir::{
 };
 use rustc_lint::LateContext;
 use rustc_middle::hir::nested_filter;
-use rustc_middle::ty::{self, AssocKind, EarlyBinder, GenericArg, GenericArgKind, Ty};
+use rustc_middle::ty::{self, AssocKind, Clause, EarlyBinder, GenericArg, GenericArgKind, PredicateKind, Ty};
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, Span, Symbol};
 
@@ -32,6 +32,8 @@ pub(super) fn check<'tcx>(
     if let Some(parent) = get_parent_node(cx.tcx, collect_expr.hir_id) {
         match parent {
             Node::Expr(parent) => {
+                check_collect_into_intoiterator(cx, parent, collect_expr, call_span, iter_expr);
+
                 if let ExprKind::MethodCall(name, _, args @ ([] | [_]), _) = parent.kind {
                     let mut app = Applicability::MachineApplicable;
                     let name = name.ident.as_str();
@@ -134,6 +136,68 @@ pub(super) fn check<'tcx>(
     }
 }
 
+/// checks for for collecting into a (generic) method or function argument
+/// taking an `IntoIterator`
+fn check_collect_into_intoiterator<'tcx>(
+    cx: &LateContext<'tcx>,
+    parent: &'tcx Expr<'tcx>,
+    collect_expr: &'tcx Expr<'tcx>,
+    call_span: Span,
+    iter_expr: &'tcx Expr<'tcx>,
+) {
+    if let Some(id) = fn_def_id(cx, parent) {
+        let args = match parent.kind {
+            ExprKind::Call(_, args) | ExprKind::MethodCall(_, _, args, _) => args,
+            _ => &[],
+        };
+        // find the argument index of the `collect_expr` in the
+        // function / method call
+        if let Some(arg_idx) = args.iter().position(|e| e.hir_id == collect_expr.hir_id).map(|i| {
+            if matches!(parent.kind, ExprKind::MethodCall(_, _, _, _)) {
+                i + 1
+            } else {
+                i
+            }
+        }) {
+            // extract the input types of the function/method call
+            // that contains `collect_expr`
+            let inputs = cx
+                .tcx
+                .liberate_late_bound_regions(id, cx.tcx.fn_sig(id).subst_identity())
+                .inputs();
+
+            // map IntoIterator generic bounds to their signature
+            // types and check whether the argument type is an
+            // `IntoIterator`
+            if cx
+                .tcx
+                .param_env(id)
+                .caller_bounds()
+                .into_iter()
+                .filter_map(|p| {
+                    if let PredicateKind::Clause(Clause::Trait(t)) = p.kind().skip_binder()
+                            && cx.tcx.is_diagnostic_item(sym::IntoIterator,t.trait_ref.def_id) {
+                                Some(t.self_ty())
+                            } else {
+                                None
+                            }
+                })
+                .any(|ty| ty == inputs[arg_idx])
+            {
+                span_lint_and_sugg(
+                    cx,
+                    NEEDLESS_COLLECT,
+                    call_span.with_lo(iter_expr.span.hi()),
+                    NEEDLESS_COLLECT_MSG,
+                    "remove this call",
+                    String::new(),
+                    Applicability::MachineApplicable,
+                );
+            }
+        }
+    }
+}
+
 /// Checks if the given method call matches the expected signature of `([&[mut]] self) -> bool`
 fn is_is_empty_sig(cx: &LateContext<'_>, call_id: HirId) -> bool {
     cx.typeck_results().type_dependent_def_id(call_id).map_or(false, |id| {

clippy_lints/src/methods/repeat_once.rs

@@ -1,4 +1,4 @@
-use clippy_utils::consts::{constant_context, Constant};
+use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet;
 use clippy_utils::ty::is_type_lang_item;
@@ -14,7 +14,7 @@ pub(super) fn check<'tcx>(
     recv: &'tcx Expr<'_>,
     repeat_arg: &'tcx Expr<'_>,
 ) {
-    if constant_context(cx, cx.typeck_results()).expr(repeat_arg) == Some(Constant::Int(1)) {
+    if constant(cx, cx.typeck_results(), repeat_arg) == Some(Constant::Int(1)) {
         let ty = cx.typeck_results().expr_ty(recv).peel_refs();
         if ty.is_str() {
             span_lint_and_sugg(

clippy_lints/src/methods/str_splitn.rs

@@ -316,7 +316,7 @@ fn parse_iter_usage<'tcx>(
                     };
                 },
                 ("nth" | "skip", [idx_expr]) if cx.tcx.trait_of_item(did) == Some(iter_id) => {
-                    if let Some((Constant::Int(idx), _)) = constant(cx, cx.typeck_results(), idx_expr) {
+                    if let Some(Constant::Int(idx)) = constant(cx, cx.typeck_results(), idx_expr) {
                         let span = if name.ident.as_str() == "nth" {
                             e.span
                         } else {

clippy_lints/src/misc.rs

@@ -16,9 +16,12 @@ use rustc_span::source_map::{ExpnKind, Span};
 
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{
-    get_parent_expr, in_constant, is_integer_literal, is_no_std_crate, iter_input_pats, last_path_segment, SpanlessEq,
+    get_parent_expr, in_constant, is_integer_literal, is_lint_allowed, is_no_std_crate, iter_input_pats,
+    last_path_segment, SpanlessEq,
 };
 
+use crate::ref_patterns::REF_PATTERNS;
+
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for function arguments and let bindings denoted as
@@ -162,6 +165,10 @@ impl<'tcx> LateLintPass<'tcx> for LintPass {
             return;
         }
         for arg in iter_input_pats(decl, body) {
+            // Do not emit if clippy::ref_patterns is not allowed to avoid having two lints for the same issue.
+            if !is_lint_allowed(cx, REF_PATTERNS, arg.pat.hir_id) {
+                return;
+            }
             if let PatKind::Binding(BindingAnnotation(ByRef::Yes, _), ..) = arg.pat.kind {
                 span_lint(
                     cx,
@@ -180,6 +187,8 @@ impl<'tcx> LateLintPass<'tcx> for LintPass {
             if let StmtKind::Local(local) = stmt.kind;
             if let PatKind::Binding(BindingAnnotation(ByRef::Yes, mutabl), .., name, None) = local.pat.kind;
             if let Some(init) = local.init;
+            // Do not emit if clippy::ref_patterns is not allowed to avoid having two lints for the same issue.
+            if is_lint_allowed(cx, REF_PATTERNS, local.pat.hir_id);
             then {
                 let ctxt = local.span.ctxt();
                 let mut app = Applicability::MachineApplicable;

clippy_lints/src/needless_bool.rs

@@ -146,7 +146,7 @@ fn is_parent_stmt(cx: &LateContext<'_>, id: HirId) -> bool {
 impl<'tcx> LateLintPass<'tcx> for NeedlessBool {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
         use self::Expression::{Bool, RetBool};
-        if e.span.from_expansion() {
+        if e.span.from_expansion() || !span_extract_comment(cx.tcx.sess.source_map(), e.span).is_empty() {
             return;
         }
         if let Some(higher::If {
@@ -209,8 +209,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBool {
             }
             if let Some((lhs_a, a)) = fetch_assign(then) &&
                 let Some((lhs_b, b)) = fetch_assign(r#else) &&
-                SpanlessEq::new(cx).eq_expr(lhs_a, lhs_b) &&
-                span_extract_comment(cx.tcx.sess.source_map(), e.span).is_empty()
+                SpanlessEq::new(cx).eq_expr(lhs_a, lhs_b)
             {
                 let mut applicability = Applicability::MachineApplicable;
                 let cond = Sugg::hir_with_applicability(cx, cond, "..", &mut applicability);

clippy_lints/src/operators/absurd_extreme_comparisons.rs

@@ -121,7 +121,7 @@ fn detect_absurd_comparison<'tcx>(
 fn detect_extreme_expr<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<ExtremeExpr<'tcx>> {
     let ty = cx.typeck_results().expr_ty(expr);
 
-    let cv = constant(cx, cx.typeck_results(), expr)?.0;
+    let cv = constant(cx, cx.typeck_results(), expr)?;
 
     let which = match (ty.kind(), cv) {
         (&ty::Bool, Constant::Bool(false)) | (&ty::Uint(_), Constant::Int(0)) => ExtremeType::Minimum,

clippy_lints/src/operators/arithmetic_side_effects.rs

@@ -21,7 +21,7 @@ const HARD_CODED_ALLOWED_BINARY: &[[&str; 2]] = &[
     ["f64", "f64"],
     ["std::num::Saturating", "std::num::Saturating"],
     ["std::num::Wrapping", "std::num::Wrapping"],
-    ["std::string::String", "&str"],
+    ["std::string::String", "str"],
 ];
 const HARD_CODED_ALLOWED_UNARY: &[&str] = &["f32", "f64", "std::num::Saturating", "std::num::Wrapping"];
 const INTEGER_METHODS: &[&str] = &["saturating_div", "wrapping_div", "wrapping_rem", "wrapping_rem_euclid"];
@@ -113,7 +113,7 @@ impl ArithmeticSideEffects {
         if let hir::ExprKind::Lit(lit) = actual.kind && let ast::LitKind::Int(n, _) = lit.node {
             return Some(n)
         }
-        if let Some((Constant::Int(n), _)) = constant(cx, cx.typeck_results(), expr) {
+        if let Some(Constant::Int(n)) = constant(cx, cx.typeck_results(), expr) {
             return Some(n);
         }
         None
@@ -144,8 +144,10 @@ impl ArithmeticSideEffects {
         ) {
             return;
         };
-        let lhs_ty = cx.typeck_results().expr_ty(lhs);
-        let rhs_ty = cx.typeck_results().expr_ty(rhs);
+        let (actual_lhs, lhs_ref_counter) = peel_hir_expr_refs(lhs);
+        let (actual_rhs, rhs_ref_counter) = peel_hir_expr_refs(rhs);
+        let lhs_ty = cx.typeck_results().expr_ty(actual_lhs).peel_refs();
+        let rhs_ty = cx.typeck_results().expr_ty(actual_rhs).peel_refs();
         if self.has_allowed_binary(lhs_ty, rhs_ty) {
             return;
         }
@@ -154,8 +156,6 @@ impl ArithmeticSideEffects {
                 // At least for integers, shifts are already handled by the CTFE
                 return;
             }
-            let (actual_lhs, lhs_ref_counter) = peel_hir_expr_refs(lhs);
-            let (actual_rhs, rhs_ref_counter) = peel_hir_expr_refs(rhs);
             match (
                 Self::literal_integer(cx, actual_lhs),
                 Self::literal_integer(cx, actual_rhs),

clippy_lints/src/operators/bit_mask.rs

@@ -166,7 +166,7 @@ fn check_ineffective_gt(cx: &LateContext<'_>, span: Span, m: u128, c: u128, op:
 }
 
 fn fetch_int_literal(cx: &LateContext<'_>, lit: &Expr<'_>) -> Option<u128> {
-    match constant(cx, cx.typeck_results(), lit)?.0 {
+    match constant(cx, cx.typeck_results(), lit)? {
         Constant::Int(n) => Some(n),
         _ => None,
     }

clippy_lints/src/operators/cmp_nan.rs

@@ -18,7 +18,7 @@ pub(super) fn check(cx: &LateContext<'_>, e: &Expr<'_>, op: BinOpKind, lhs: &Exp
 }
 
 fn is_nan(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
-    if let Some((value, _)) = constant(cx, cx.typeck_results(), e) {
+    if let Some(value) = constant(cx, cx.typeck_results(), e) {
         match value {
             Constant::F32(num) => num.is_nan(),
             Constant::F64(num) => num.is_nan(),

clippy_lints/src/operators/duration_subsec.rs

@@ -19,7 +19,7 @@ pub(crate) fn check<'tcx>(
     if op == BinOpKind::Div
         && let ExprKind::MethodCall(method_path, self_arg, [], _) = left.kind
         && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(self_arg).peel_refs(), sym::Duration)
-        && let Some((Constant::Int(divisor), _)) = constant(cx, cx.typeck_results(), right)
+        && let Some(Constant::Int(divisor)) = constant(cx, cx.typeck_results(), right)
     {
         let suggested_fn = match (method_path.ident.as_str(), divisor) {
             ("subsec_micros", 1_000) | ("subsec_nanos", 1_000_000) => "subsec_millis",

clippy_lints/src/operators/float_cmp.rs

@@ -1,4 +1,4 @@
-use clippy_utils::consts::{constant, Constant};
+use clippy_utils::consts::{constant_with_source, Constant};
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::get_item_name;
 use clippy_utils::sugg::Sugg;
@@ -18,9 +18,16 @@ pub(crate) fn check<'tcx>(
     right: &'tcx Expr<'_>,
 ) {
     if (op == BinOpKind::Eq || op == BinOpKind::Ne) && (is_float(cx, left) || is_float(cx, right)) {
-        if is_allowed(cx, left) || is_allowed(cx, right) {
-            return;
-        }
+        let left_is_local = match constant_with_source(cx, cx.typeck_results(), left) {
+            Some((c, s)) if !is_allowed(&c) => s.is_local(),
+            Some(_) => return,
+            None => true,
+        };
+        let right_is_local = match constant_with_source(cx, cx.typeck_results(), right) {
+            Some((c, s)) if !is_allowed(&c) => s.is_local(),
+            Some(_) => return,
+            None => true,
+        };
 
         // Allow comparing the results of signum()
         if is_signum(cx, left) && is_signum(cx, right) {
@@ -34,10 +41,7 @@ pub(crate) fn check<'tcx>(
             }
         }
         let is_comparing_arrays = is_array(cx, left) || is_array(cx, right);
-        let (lint, msg) = get_lint_and_message(
-            is_named_constant(cx, left) || is_named_constant(cx, right),
-            is_comparing_arrays,
-        );
+        let (lint, msg) = get_lint_and_message(left_is_local && right_is_local, is_comparing_arrays);
         span_lint_and_then(cx, lint, expr.span, msg, |diag| {
             let lhs = Sugg::hir(cx, left, "..");
             let rhs = Sugg::hir(cx, right, "..");
@@ -59,20 +63,8 @@ pub(crate) fn check<'tcx>(
     }
 }
 
-fn get_lint_and_message(
-    is_comparing_constants: bool,
-    is_comparing_arrays: bool,
-) -> (&'static rustc_lint::Lint, &'static str) {
-    if is_comparing_constants {
-        (
-            FLOAT_CMP_CONST,
-            if is_comparing_arrays {
-                "strict comparison of `f32` or `f64` constant arrays"
-            } else {
-                "strict comparison of `f32` or `f64` constant"
-            },
-        )
-    } else {
+fn get_lint_and_message(is_local: bool, is_comparing_arrays: bool) -> (&'static rustc_lint::Lint, &'static str) {
+    if is_local {
         (
             FLOAT_CMP,
             if is_comparing_arrays {
@@ -81,22 +73,23 @@ fn get_lint_and_message(
                 "strict comparison of `f32` or `f64`"
             },
         )
-    }
-}
-
-fn is_named_constant<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
-    if let Some((_, res)) = constant(cx, cx.typeck_results(), expr) {
-        res
     } else {
-        false
+        (
+            FLOAT_CMP_CONST,
+            if is_comparing_arrays {
+                "strict comparison of `f32` or `f64` constant arrays"
+            } else {
+                "strict comparison of `f32` or `f64` constant"
+            },
+        )
     }
 }
 
-fn is_allowed<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
-    match constant(cx, cx.typeck_results(), expr) {
-        Some((Constant::F32(f), _)) => f == 0.0 || f.is_infinite(),
-        Some((Constant::F64(f), _)) => f == 0.0 || f.is_infinite(),
-        Some((Constant::Vec(vec), _)) => vec.iter().all(|f| match f {
+fn is_allowed(val: &Constant) -> bool {
+    match val {
+        &Constant::F32(f) => f == 0.0 || f.is_infinite(),
+        &Constant::F64(f) => f == 0.0 || f.is_infinite(),
+        Constant::Vec(vec) => vec.iter().all(|f| match f {
             Constant::F32(f) => *f == 0.0 || (*f).is_infinite(),
             Constant::F64(f) => *f == 0.0 || (*f).is_infinite(),
             _ => false,

clippy_lints/src/operators/mod.rs

@@ -96,32 +96,6 @@ declare_clippy_lint! {
     "any arithmetic expression that can cause side effects like overflows or panics"
 }
 
-declare_clippy_lint! {
-    /// ### What it does
-    /// Checks for integer arithmetic operations which could overflow or panic.
-    ///
-    /// Specifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable
-    /// of overflowing according to the [Rust
-    /// Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
-    /// or which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is
-    /// attempted.
-    ///
-    /// ### Why is this bad?
-    /// Integer overflow will trigger a panic in debug builds or will wrap in
-    /// release mode. Division by zero will cause a panic in either mode. In some applications one
-    /// wants explicitly checked, wrapping or saturating arithmetic.
-    ///
-    /// ### Example
-    /// ```rust
-    /// # let a = 0;
-    /// a + 1;
-    /// ```
-    #[clippy::version = "pre 1.29.0"]
-    pub INTEGER_ARITHMETIC,
-    restriction,
-    "any integer arithmetic expression which could overflow or panic"
-}
-
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for float arithmetic.
@@ -787,7 +761,6 @@ pub struct Operators {
 impl_lint_pass!(Operators => [
     ABSURD_EXTREME_COMPARISONS,
     ARITHMETIC_SIDE_EFFECTS,
-    INTEGER_ARITHMETIC,
     FLOAT_ARITHMETIC,
     ASSIGN_OP_PATTERN,
     MISREFACTORED_ASSIGN_OP,

clippy_lints/src/operators/modulo_arithmetic.rs

@@ -40,7 +40,7 @@ struct OperandInfo {
 
 fn analyze_operand(operand: &Expr<'_>, cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<OperandInfo> {
     match constant(cx, cx.typeck_results(), operand) {
-        Some((Constant::Int(v), _)) => match *cx.typeck_results().expr_ty(expr).kind() {
+        Some(Constant::Int(v)) => match *cx.typeck_results().expr_ty(expr).kind() {
             ty::Int(ity) => {
                 let value = sext(cx.tcx, v, ity);
                 return Some(OperandInfo {
@@ -58,10 +58,10 @@ fn analyze_operand(operand: &Expr<'_>, cx: &LateContext<'_>, expr: &Expr<'_>) ->
             },
             _ => {},
         },
-        Some((Constant::F32(f), _)) => {
+        Some(Constant::F32(f)) => {
             return Some(floating_point_operand_info(&f));
         },
-        Some((Constant::F64(f), _)) => {
+        Some(Constant::F64(f)) => {
             return Some(floating_point_operand_info(&f));
         },
         _ => {},

clippy_lints/src/operators/numeric_arithmetic.rs

@@ -1,8 +1,6 @@
-use super::{FLOAT_ARITHMETIC, INTEGER_ARITHMETIC};
+use super::FLOAT_ARITHMETIC;
 use clippy_utils::consts::constant_simple;
 use clippy_utils::diagnostics::span_lint;
-use clippy_utils::is_from_proc_macro;
-use clippy_utils::is_integer_literal;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
 use rustc_span::source_map::Span;
@@ -45,31 +43,8 @@ impl Context {
             _ => (),
         }
 
-        let (l_ty, r_ty) = (cx.typeck_results().expr_ty(l), cx.typeck_results().expr_ty(r));
-        if l_ty.peel_refs().is_integral() && r_ty.peel_refs().is_integral() {
-            if is_from_proc_macro(cx, expr) {
-                return;
-            }
-            match op {
-                hir::BinOpKind::Div | hir::BinOpKind::Rem => match &r.kind {
-                    hir::ExprKind::Lit(_lit) => (),
-                    hir::ExprKind::Unary(hir::UnOp::Neg, expr) => {
-                        if is_integer_literal(expr, 1) {
-                            span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
-                            self.expr_id = Some(expr.hir_id);
-                        }
-                    },
-                    _ => {
-                        span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
-                        self.expr_id = Some(expr.hir_id);
-                    },
-                },
-                _ => {
-                    span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
-                    self.expr_id = Some(expr.hir_id);
-                },
-            }
-        } else if r_ty.peel_refs().is_floating_point() && r_ty.peel_refs().is_floating_point() {
+        let (_, r_ty) = (cx.typeck_results().expr_ty(l), cx.typeck_results().expr_ty(r));
+        if r_ty.peel_refs().is_floating_point() && r_ty.peel_refs().is_floating_point() {
             span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
             self.expr_id = Some(expr.hir_id);
         }
@@ -80,17 +55,9 @@ impl Context {
             return;
         }
         let ty = cx.typeck_results().expr_ty(arg);
-        if constant_simple(cx, cx.typeck_results(), expr).is_none() {
-            if ty.is_integral() {
-                if is_from_proc_macro(cx, expr) {
-                    return;
-                }
-                span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
-                self.expr_id = Some(expr.hir_id);
-            } else if ty.is_floating_point() {
-                span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
-                self.expr_id = Some(expr.hir_id);
-            }
+        if constant_simple(cx, cx.typeck_results(), expr).is_none() && ty.is_floating_point() {
+            span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
+            self.expr_id = Some(expr.hir_id);
         }
     }
 

clippy_lints/src/option_if_let_else.rs

@@ -122,7 +122,7 @@ fn try_get_option_occurrence<'tcx>(
         ExprKind::Unary(UnOp::Deref, inner_expr) | ExprKind::AddrOf(_, _, inner_expr) => inner_expr,
         _ => expr,
     };
-    let inner_pat = try_get_inner_pat(cx, pat)?;
+    let (inner_pat, is_result) = try_get_inner_pat_and_is_result(cx, pat)?;
     if_chain! {
         if let PatKind::Binding(bind_annotation, _, id, None) = inner_pat.kind;
         if let Some(some_captures) = can_move_expr_to_closure(cx, if_then);
@@ -176,7 +176,7 @@ fn try_get_option_occurrence<'tcx>(
                 ),
                 none_expr: format!(
                     "{}{}",
-                    if method_sugg == "map_or" { "" } else { "|| " },
+                    if method_sugg == "map_or" { "" } else if is_result { "|_| " } else { "|| "},
                     Sugg::hir_with_context(cx, none_body, ctxt, "..", &mut app),
                 ),
             });
@@ -186,11 +186,13 @@ fn try_get_option_occurrence<'tcx>(
     None
 }
 
-fn try_get_inner_pat<'tcx>(cx: &LateContext<'tcx>, pat: &Pat<'tcx>) -> Option<&'tcx Pat<'tcx>> {
+fn try_get_inner_pat_and_is_result<'tcx>(cx: &LateContext<'tcx>, pat: &Pat<'tcx>) -> Option<(&'tcx Pat<'tcx>, bool)> {
     if let PatKind::TupleStruct(ref qpath, [inner_pat], ..) = pat.kind {
         let res = cx.qpath_res(qpath, pat.hir_id);
-        if is_res_lang_ctor(cx, res, OptionSome) || is_res_lang_ctor(cx, res, ResultOk) {
-            return Some(inner_pat);
+        if is_res_lang_ctor(cx, res, OptionSome) {
+            return Some((inner_pat, false));
+        } else if is_res_lang_ctor(cx, res, ResultOk) {
+            return Some((inner_pat, true));
         }
     }
     None

clippy_lints/src/ranges.rs

@@ -319,7 +319,7 @@ fn check_range_bounds<'a>(cx: &'a LateContext<'_>, ex: &'a Expr<'_>) -> Option<R
             _ => return None,
         };
         if let Some(id) = path_to_local(l) {
-            if let Some((c, _)) = constant(cx, cx.typeck_results(), r) {
+            if let Some(c) = constant(cx, cx.typeck_results(), r) {
                 return Some(RangeBounds {
                     val: c,
                     expr: r,
@@ -331,7 +331,7 @@ fn check_range_bounds<'a>(cx: &'a LateContext<'_>, ex: &'a Expr<'_>) -> Option<R
                 });
             }
         } else if let Some(id) = path_to_local(r) {
-            if let Some((c, _)) = constant(cx, cx.typeck_results(), l) {
+            if let Some(c) = constant(cx, cx.typeck_results(), l) {
                 return Some(RangeBounds {
                     val: c,
                     expr: l,
@@ -451,8 +451,8 @@ fn check_reversed_empty_range(cx: &LateContext<'_>, expr: &Expr<'_>) {
         if let Some(higher::Range { start: Some(start), end: Some(end), limits }) = higher::Range::hir(expr);
         let ty = cx.typeck_results().expr_ty(start);
         if let ty::Int(_) | ty::Uint(_) = ty.kind();
-        if let Some((start_idx, _)) = constant(cx, cx.typeck_results(), start);
-        if let Some((end_idx, _)) = constant(cx, cx.typeck_results(), end);
+        if let Some(start_idx) = constant(cx, cx.typeck_results(), start);
+        if let Some(end_idx) = constant(cx, cx.typeck_results(), end);
         if let Some(ordering) = Constant::partial_cmp(cx.tcx, ty, &start_idx, &end_idx);
         if is_empty_range(limits, ordering);
         then {

clippy_lints/src/ref_patterns.rs

@@ -0,0 +1,44 @@
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{BindingAnnotation, Pat, PatKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for usages of the `ref` keyword.
+    /// ### Why is this bad?
+    /// The `ref` keyword can be confusing for people unfamiliar with it, and often
+    /// it is more concise to use `&` instead.
+    /// ### Example
+    /// ```rust
+    /// let opt = Some(5);
+    /// if let Some(ref foo) = opt {}
+    /// ```
+    /// Use instead:
+    /// ```rust
+    /// let opt = Some(5);
+    /// if let Some(foo) = &opt {}
+    /// ```
+    #[clippy::version = "1.71.0"]
+    pub REF_PATTERNS,
+    restriction,
+    "use of a ref pattern, e.g. Some(ref value)"
+}
+declare_lint_pass!(RefPatterns => [REF_PATTERNS]);
+
+impl EarlyLintPass for RefPatterns {
+    fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &Pat) {
+        if let PatKind::Ident(BindingAnnotation::REF, _, _) = pat.kind
+                && !pat.span.from_expansion()
+        {
+            span_lint_and_help(
+                cx,
+                REF_PATTERNS,
+                pat.span,
+                "usage of ref pattern",
+                None,
+                "consider using `&` for clarity instead",
+            );
+        }
+    }
+}

clippy_lints/src/regex.rs

@@ -122,37 +122,39 @@ fn lint_syntax_error(cx: &LateContext<'_>, error: &regex_syntax::Error, unescape
 }
 
 fn const_str<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> Option<String> {
-    constant(cx, cx.typeck_results(), e).and_then(|(c, _)| match c {
+    constant(cx, cx.typeck_results(), e).and_then(|c| match c {
         Constant::Str(s) => Some(s),
         _ => None,
     })
 }
 
 fn is_trivial_regex(s: &regex_syntax::hir::Hir) -> Option<&'static str> {
-    use regex_syntax::hir::Anchor::{EndText, StartText};
-    use regex_syntax::hir::HirKind::{Alternation, Anchor, Concat, Empty, Literal};
+    use regex_syntax::hir::HirKind::{Alternation, Concat, Empty, Literal, Look};
+    use regex_syntax::hir::Look as HirLook;
 
     let is_literal = |e: &[regex_syntax::hir::Hir]| e.iter().all(|e| matches!(*e.kind(), Literal(_)));
 
     match *s.kind() {
-        Empty | Anchor(_) => Some("the regex is unlikely to be useful as it is"),
+        Empty | Look(_) => Some("the regex is unlikely to be useful as it is"),
         Literal(_) => Some("consider using `str::contains`"),
         Alternation(ref exprs) => {
-            if exprs.iter().all(|e| e.kind().is_empty()) {
+            if exprs.iter().all(|e| matches!(e.kind(), Empty)) {
                 Some("the regex is unlikely to be useful as it is")
             } else {
                 None
             }
         },
         Concat(ref exprs) => match (exprs[0].kind(), exprs[exprs.len() - 1].kind()) {
-            (&Anchor(StartText), &Anchor(EndText)) if exprs[1..(exprs.len() - 1)].is_empty() => {
+            (&Look(HirLook::Start), &Look(HirLook::End)) if exprs[1..(exprs.len() - 1)].is_empty() => {
                 Some("consider using `str::is_empty`")
             },
-            (&Anchor(StartText), &Anchor(EndText)) if is_literal(&exprs[1..(exprs.len() - 1)]) => {
+            (&Look(HirLook::Start), &Look(HirLook::End)) if is_literal(&exprs[1..(exprs.len() - 1)]) => {
                 Some("consider using `==` on `str`s")
             },
-            (&Anchor(StartText), &Literal(_)) if is_literal(&exprs[1..]) => Some("consider using `str::starts_with`"),
-            (&Literal(_), &Anchor(EndText)) if is_literal(&exprs[1..(exprs.len() - 1)]) => {
+            (&Look(HirLook::Start), &Literal(_)) if is_literal(&exprs[1..]) => {
+                Some("consider using `str::starts_with`")
+            },
+            (&Literal(_), &Look(HirLook::End)) if is_literal(&exprs[1..(exprs.len() - 1)]) => {
                 Some("consider using `str::ends_with`")
             },
             _ if is_literal(exprs) => Some("consider using `str::contains`"),
@@ -175,10 +177,7 @@ fn check_set<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, utf8: bool) {
 }
 
 fn check_regex<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, utf8: bool) {
-    let mut parser = regex_syntax::ParserBuilder::new()
-        .unicode(true)
-        .allow_invalid_utf8(!utf8)
-        .build();
+    let mut parser = regex_syntax::ParserBuilder::new().unicode(true).utf8(!utf8).build();
 
     if let ExprKind::Lit(lit) = expr.kind {
         if let LitKind::Str(ref r, style) = lit.node {

clippy_lints/src/renamed_lints.rs

@@ -15,6 +15,7 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[
     ("clippy::eval_order_dependence", "clippy::mixed_read_write_in_expression"),
     ("clippy::identity_conversion", "clippy::useless_conversion"),
     ("clippy::if_let_some_result", "clippy::match_result_ok"),
+    ("clippy::integer_arithmetic", "clippy::arithmetic_side_effects"),
     ("clippy::logic_bug", "clippy::overly_complex_bool_expr"),
     ("clippy::new_without_default_derive", "clippy::new_without_default"),
     ("clippy::option_and_then_some", "clippy::bind_instead_of_map"),

clippy_lints/src/strings.rs

@@ -132,7 +132,7 @@ declare_clippy_lint! {
     /// Probably lots of false positives. If an index comes from a known valid position (e.g.
     /// obtained via `char_indices` over the same string), it is totally OK.
     ///
-    /// # Example
+    /// ### Example
     /// ```rust,should_panic
     /// &"Ölkanne"[1..];
     /// ```

clippy_lints/src/trait_bounds.rs

@@ -37,12 +37,12 @@ declare_clippy_lint! {
     #[clippy::version = "1.38.0"]
     pub TYPE_REPETITION_IN_BOUNDS,
     nursery,
-    "types are repeated unnecessary in trait bounds use `+` instead of using `T: _, T: _`"
+    "types are repeated unnecessarily in trait bounds, use `+` instead of using `T: _, T: _`"
 }
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for cases where generics are being used and multiple
+    /// Checks for cases where generics or trait objects are being used and multiple
     /// syntax specifications for trait bounds are used simultaneously.
     ///
     /// ### Why is this bad?
@@ -167,6 +167,61 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
             }
         }
     }
+
+    fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
+        if_chain! {
+            if let TyKind::Ref(.., mut_ty) = &ty.kind;
+            if let TyKind::TraitObject(bounds, ..) = mut_ty.ty.kind;
+            if bounds.len() > 2;
+            then {
+
+                // Build up a hash of every trait we've seen
+                // When we see a trait for the first time, add it to unique_traits
+                // so we can later use it to build a string of all traits exactly once, without duplicates
+
+                let mut seen_def_ids = FxHashSet::default();
+                let mut unique_traits = Vec::new();
+
+                // Iterate the bounds and add them to our seen hash
+                // If we haven't yet seen it, add it to the fixed traits
+                for bound in bounds.iter() {
+                    let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
+
+                    let new_trait = seen_def_ids.insert(def_id);
+
+                    if new_trait {
+                        unique_traits.push(bound);
+                    }
+                }
+
+                // If the number of unique traits isn't the same as the number of traits in the bounds,
+                // there must be 1 or more duplicates
+                if bounds.len() != unique_traits.len() {
+                    let mut bounds_span = bounds[0].span;
+
+                    for bound in bounds.iter().skip(1) {
+                        bounds_span = bounds_span.to(bound.span);
+                    }
+
+                    let fixed_trait_snippet = unique_traits
+                        .iter()
+                        .filter_map(|b| snippet_opt(cx, b.span))
+                        .collect::<Vec<_>>()
+                        .join(" + ");
+
+                    span_lint_and_sugg(
+                        cx,
+                        TRAIT_DUPLICATION_IN_BOUNDS,
+                        bounds_span,
+                        "this trait bound is already specified in trait declaration",
+                        "try",
+                        fixed_trait_snippet,
+                        Applicability::MaybeIncorrect,
+                    );
+                }
+            }
+        }
+    }
 }
 
 impl TraitBounds {

clippy_lints/src/transmute/transmute_null_to_fn.rs

@@ -31,9 +31,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, arg: &'t
     match arg.kind {
         // Catching:
         // transmute over constants that resolve to `null`.
-        ExprKind::Path(ref _qpath)
-            if matches!(constant(cx, cx.typeck_results(), arg), Some((Constant::RawPtr(0), _))) =>
-        {
+        ExprKind::Path(ref _qpath) if matches!(constant(cx, cx.typeck_results(), arg), Some(Constant::RawPtr(0))) => {
             lint_expr(cx, expr);
             true
         },

clippy_lints/src/transmute/transmuting_null.rs

@@ -1,4 +1,4 @@
-use clippy_utils::consts::{constant_context, Constant};
+use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::{is_integer_literal, is_path_diagnostic_item};
 use rustc_hir::{Expr, ExprKind};
@@ -16,9 +16,8 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, arg: &'t
     }
 
     // Catching transmute over constants that resolve to `null`.
-    let mut const_eval_context = constant_context(cx, cx.typeck_results());
     if let ExprKind::Path(ref _qpath) = arg.kind &&
-        let Some(Constant::RawPtr(0)) = const_eval_context.expr(arg)
+        let Some(Constant::RawPtr(0)) = constant(cx, cx.typeck_results(), arg)
     {
         span_lint(cx, TRANSMUTING_NULL, expr.span, LINT_MSG);
         return true;

clippy_lints/src/useless_conversion.rs

@@ -1,4 +1,5 @@
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
+use clippy_utils::is_ty_alias;
 use clippy_utils::source::{snippet, snippet_with_context};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::ty::{is_copy, is_type_diagnostic_item, same_type_and_consts};
@@ -138,6 +139,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
                 if_chain! {
                     if let ExprKind::Path(ref qpath) = path.kind;
                     if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id();
+                    if !is_ty_alias(qpath);
                     then {
                         let a = cx.typeck_results().expr_ty(e);
                         let b = cx.typeck_results().expr_ty(arg);

clippy_lints/src/utils/author.rs

@@ -308,7 +308,7 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
                 bind!(self, vec);
                 kind!("CStr(ref {vec})");
                 chain!(self, "let [{:?}] = **{vec}", vec.value);
-            }
+            },
             LitKind::Str(s, _) => {
                 bind!(self, s);
                 kind!("Str({s}, _)");

clippy_lints/src/utils/conf.rs

@@ -174,16 +174,15 @@ macro_rules! define_Conf {
             }
         }
 
-        #[cfg(feature = "internal")]
         pub mod metadata {
-            use crate::utils::internal_lints::metadata_collector::ClippyConfiguration;
+            use crate::utils::ClippyConfiguration;
 
             macro_rules! wrap_option {
                 () => (None);
                 ($x:literal) => (Some($x));
             }
 
-            pub(crate) fn get_configuration_metadata() -> Vec<ClippyConfiguration> {
+            pub fn get_configuration_metadata() -> Vec<ClippyConfiguration> {
                 vec![
                     $(
                         {

clippy_lints/src/utils/internal_lints/metadata_collector.rs

@@ -8,7 +8,11 @@
 //! a simple mistake)
 
 use crate::renamed_lints::RENAMED_LINTS;
-use crate::utils::internal_lints::lint_without_lint_pass::{extract_clippy_version_value, is_lint_ref_type};
+use crate::utils::{
+    collect_configs,
+    internal_lints::lint_without_lint_pass::{extract_clippy_version_value, is_lint_ref_type},
+    ClippyConfiguration,
+};
 
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::ty::{match_type, walk_ptrs_ty_depth};
@@ -520,111 +524,6 @@ impl Serialize for ApplicabilityInfo {
     }
 }
 
-// ==================================================================
-// Configuration
-// ==================================================================
-#[derive(Debug, Clone, Default)]
-pub struct ClippyConfiguration {
-    name: String,
-    config_type: &'static str,
-    default: String,
-    lints: Vec<String>,
-    doc: String,
-    #[allow(dead_code)]
-    deprecation_reason: Option<&'static str>,
-}
-
-impl ClippyConfiguration {
-    pub fn new(
-        name: &'static str,
-        config_type: &'static str,
-        default: String,
-        doc_comment: &'static str,
-        deprecation_reason: Option<&'static str>,
-    ) -> Self {
-        let (lints, doc) = parse_config_field_doc(doc_comment)
-            .unwrap_or_else(|| (vec![], "[ERROR] MALFORMED DOC COMMENT".to_string()));
-
-        Self {
-            name: to_kebab(name),
-            lints,
-            doc,
-            config_type,
-            default,
-            deprecation_reason,
-        }
-    }
-
-    fn to_markdown_paragraph(&self) -> String {
-        format!(
-            "### {}\n{}\n\n**Default Value:** `{}` (`{}`)\n\n{}\n\n",
-            self.name,
-            self.doc
-                .lines()
-                .map(|line| line.strip_prefix("    ").unwrap_or(line))
-                .join("\n"),
-            self.default,
-            self.config_type,
-            self.lints
-                .iter()
-                .map(|name| name.to_string().split_whitespace().next().unwrap().to_string())
-                .map(|name| format!("* [{name}](https://rust-lang.github.io/rust-clippy/master/index.html#{name})"))
-                .join("\n"),
-        )
-    }
-
-    fn to_markdown_table_entry(&self) -> String {
-        format!("| [{}](#{}) | `{}` |", self.name, self.name, self.default)
-    }
-}
-
-fn collect_configs() -> Vec<ClippyConfiguration> {
-    crate::utils::conf::metadata::get_configuration_metadata()
-}
-
-/// This parses the field documentation of the config struct.
-///
-/// ```rust, ignore
-/// parse_config_field_doc(cx, "Lint: LINT_NAME_1, LINT_NAME_2. Papa penguin, papa penguin")
-/// ```
-///
-/// Would yield:
-/// ```rust, ignore
-/// Some(["lint_name_1", "lint_name_2"], "Papa penguin, papa penguin")
-/// ```
-fn parse_config_field_doc(doc_comment: &str) -> Option<(Vec<String>, String)> {
-    const DOC_START: &str = " Lint: ";
-    if_chain! {
-        if doc_comment.starts_with(DOC_START);
-        if let Some(split_pos) = doc_comment.find('.');
-        then {
-            let mut doc_comment = doc_comment.to_string();
-            let mut documentation = doc_comment.split_off(split_pos);
-
-            // Extract lints
-            doc_comment.make_ascii_lowercase();
-            let lints: Vec<String> = doc_comment
-                .split_off(DOC_START.len())
-                .split(", ")
-                .map(str::to_string)
-                .collect();
-
-            // Format documentation correctly
-            // split off leading `.` from lint name list and indent for correct formatting
-            documentation = documentation.trim_start_matches('.').trim().replace("\n ", "\n    ");
-
-            Some((lints, documentation))
-        } else {
-            None
-        }
-    }
-}
-
-/// Transforms a given `snake_case_string` to a tasty `kebab-case-string`
-fn to_kebab(config_name: &str) -> String {
-    config_name.replace('_', "-")
-}
-
 impl fmt::Display for ClippyConfiguration {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> fmt::Result {
         writeln!(

clippy_lints/src/utils/mod.rs

@@ -4,3 +4,143 @@ pub mod dump_hir;
 pub mod format_args_collector;
 #[cfg(feature = "internal")]
 pub mod internal_lints;
+#[cfg(feature = "internal")]
+use itertools::Itertools;
+
+/// Transforms a given `snake_case_string` to a tasty `kebab-case-string`
+fn to_kebab(config_name: &str) -> String {
+    config_name.replace('_', "-")
+}
+
+// ==================================================================
+// Configuration
+// ==================================================================
+#[derive(Debug, Clone, Default)] //~ ERROR no such field
+pub struct ClippyConfiguration {
+    pub name: String,
+    #[allow(dead_code)]
+    config_type: &'static str,
+    pub default: String,
+    pub lints: Vec<String>,
+    pub doc: String,
+    #[allow(dead_code)]
+    deprecation_reason: Option<&'static str>,
+}
+
+impl ClippyConfiguration {
+    pub fn new(
+        name: &'static str,
+        config_type: &'static str,
+        default: String,
+        doc_comment: &'static str,
+        deprecation_reason: Option<&'static str>,
+    ) -> Self {
+        let (lints, doc) = parse_config_field_doc(doc_comment)
+            .unwrap_or_else(|| (vec![], "[ERROR] MALFORMED DOC COMMENT".to_string()));
+
+        Self {
+            name: to_kebab(name),
+            lints,
+            doc,
+            config_type,
+            default,
+            deprecation_reason,
+        }
+    }
+
+    #[cfg(feature = "internal")]
+    fn to_markdown_paragraph(&self) -> String {
+        format!(
+            "### {}\n{}\n\n**Default Value:** `{}` (`{}`)\n\n{}\n\n",
+            self.name,
+            self.doc
+                .lines()
+                .map(|line| line.strip_prefix("    ").unwrap_or(line))
+                .join("\n"),
+            self.default,
+            self.config_type,
+            self.lints
+                .iter()
+                .map(|name| name.to_string().split_whitespace().next().unwrap().to_string())
+                .map(|name| format!("* [{name}](https://rust-lang.github.io/rust-clippy/master/index.html#{name})"))
+                .join("\n"),
+        )
+    }
+
+    #[cfg(feature = "internal")]
+    fn to_markdown_table_entry(&self) -> String {
+        format!("| [{}](#{}) | `{}` |", self.name, self.name, self.default)
+    }
+}
+
+#[cfg(feature = "internal")]
+fn collect_configs() -> Vec<ClippyConfiguration> {
+    crate::utils::conf::metadata::get_configuration_metadata()
+}
+
+/// This parses the field documentation of the config struct.
+///
+/// ```rust, ignore
+/// parse_config_field_doc(cx, "Lint: LINT_NAME_1, LINT_NAME_2. Papa penguin, papa penguin")
+/// ```
+///
+/// Would yield:
+/// ```rust, ignore
+/// Some(["lint_name_1", "lint_name_2"], "Papa penguin, papa penguin")
+/// ```
+fn parse_config_field_doc(doc_comment: &str) -> Option<(Vec<String>, String)> {
+    const DOC_START: &str = " Lint: ";
+    if_chain! {
+        if doc_comment.starts_with(DOC_START);
+        if let Some(split_pos) = doc_comment.find('.');
+        then {
+            let mut doc_comment = doc_comment.to_string();
+            let mut documentation = doc_comment.split_off(split_pos);
+
+            // Extract lints
+            doc_comment.make_ascii_lowercase();
+            let lints: Vec<String> = doc_comment
+                .split_off(DOC_START.len())
+                .split(", ")
+                .map(str::to_string)
+                .collect();
+
+            // Format documentation correctly
+            // split off leading `.` from lint name list and indent for correct formatting
+            documentation = documentation.trim_start_matches('.').trim().replace("\n ", "\n    ");
+
+            Some((lints, documentation))
+        } else {
+            None
+        }
+    }
+}
+
+// Shamelessly stolen from find_all (https://github.com/nectariner/find_all)
+pub trait FindAll: Iterator + Sized {
+    fn find_all<P>(&mut self, predicate: P) -> Option<Vec<usize>>
+    where
+        P: FnMut(&Self::Item) -> bool;
+}
+
+impl<I> FindAll for I
+where
+    I: Iterator,
+{
+    fn find_all<P>(&mut self, mut predicate: P) -> Option<Vec<usize>>
+    where
+        P: FnMut(&Self::Item) -> bool,
+    {
+        let mut occurences = Vec::<usize>::default();
+        for (index, element) in self.enumerate() {
+            if predicate(&element) {
+                occurences.push(index);
+            }
+        }
+
+        match occurences.len() {
+            0 => None,
+            _ => Some(occurences),
+        }
+    }
+}

clippy_lints/src/vec.rs

@@ -84,7 +84,7 @@ impl UselessVec {
         let mut applicability = Applicability::MachineApplicable;
         let snippet = match *vec_args {
             higher::VecArgs::Repeat(elem, len) => {
-                if let Some((Constant::Int(len_constant), _)) = constant(cx, cx.typeck_results(), len) {
+                if let Some(Constant::Int(len_constant)) = constant(cx, cx.typeck_results(), len) {
                     #[expect(clippy::cast_possible_truncation)]
                     if len_constant as u64 * size_of(cx, elem) > self.too_large_for_stack {
                         return;

clippy_lints/src/wildcard_imports.rs

@@ -7,7 +7,7 @@ use rustc_hir::{
     def::{DefKind, Res},
     Item, ItemKind, PathSegment, UseKind,
 };
-use rustc_lint::{LateContext, LateLintPass};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::ty;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::symbol::kw;
@@ -117,6 +117,10 @@ impl_lint_pass!(WildcardImports => [ENUM_GLOB_USE, WILDCARD_IMPORTS]);
 
 impl LateLintPass<'_> for WildcardImports {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+        if cx.sess().is_test_crate() {
+            return;
+        }
+
         if is_test_module_or_function(cx.tcx, item) {
             self.test_modules_deep = self.test_modules_deep.saturating_add(1);
         }

clippy_utils/src/consts.rs

@@ -1,18 +1,21 @@
 #![allow(clippy::float_cmp)]
 
+use crate::source::{get_source_text, walk_span_to_context};
 use crate::{clip, is_direct_expn_of, sext, unsext};
 use if_chain::if_chain;
 use rustc_ast::ast::{self, LitFloatType, LitKind};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
+use rustc_lexer::tokenize;
 use rustc_lint::LateContext;
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::Scalar;
-use rustc_middle::ty::SubstsRef;
 use rustc_middle::ty::{self, EarlyBinder, FloatTy, ScalarInt, Ty, TyCtxt};
+use rustc_middle::ty::{List, SubstsRef};
 use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::Symbol;
+use rustc_span::SyntaxContext;
 use std::cmp::Ordering::{self, Equal};
 use std::hash::{Hash, Hasher};
 use std::iter;
@@ -210,8 +213,7 @@ pub fn lit_to_mir_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
     match *lit {
         LitKind::Str(ref is, _) => Constant::Str(is.to_string()),
         LitKind::Byte(b) => Constant::Int(u128::from(b)),
-        LitKind::ByteStr(ref s, _) => Constant::Binary(Lrc::clone(s)),
-        LitKind::CStr(ref s, _) => Constant::Binary(Lrc::clone(s)),
+        LitKind::ByteStr(ref s, _) | LitKind::CStr(ref s, _) => Constant::Binary(Lrc::clone(s)),
         LitKind::Char(c) => Constant::Char(c),
         LitKind::Int(n, _) => Constant::Int(n),
         LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {
@@ -228,27 +230,46 @@ pub fn lit_to_mir_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
     }
 }
 
+/// The source of a constant value.
+pub enum ConstantSource {
+    /// The value is determined solely from the expression.
+    Local,
+    /// The value is dependent on a defined constant.
+    Constant,
+}
+impl ConstantSource {
+    pub fn is_local(&self) -> bool {
+        matches!(self, Self::Local)
+    }
+}
+
+/// Attempts to evaluate the expression as a constant.
 pub fn constant<'tcx>(
     lcx: &LateContext<'tcx>,
     typeck_results: &ty::TypeckResults<'tcx>,
     e: &Expr<'_>,
-) -> Option<(Constant, bool)> {
-    let mut cx = ConstEvalLateContext {
-        lcx,
-        typeck_results,
-        param_env: lcx.param_env,
-        needed_resolution: false,
-        substs: ty::List::empty(),
-    };
-    cx.expr(e).map(|cst| (cst, cx.needed_resolution))
+) -> Option<Constant> {
+    ConstEvalLateContext::new(lcx, typeck_results).expr(e)
 }
 
+/// Attempts to evaluate the expression as a constant.
+pub fn constant_with_source<'tcx>(
+    lcx: &LateContext<'tcx>,
+    typeck_results: &ty::TypeckResults<'tcx>,
+    e: &Expr<'_>,
+) -> Option<(Constant, ConstantSource)> {
+    let mut ctxt = ConstEvalLateContext::new(lcx, typeck_results);
+    let res = ctxt.expr(e);
+    res.map(|x| (x, ctxt.source))
+}
+
+/// Attempts to evaluate an expression only if it's value is not dependent on other items.
 pub fn constant_simple<'tcx>(
     lcx: &LateContext<'tcx>,
     typeck_results: &ty::TypeckResults<'tcx>,
     e: &Expr<'_>,
 ) -> Option<Constant> {
-    constant(lcx, typeck_results, e).and_then(|(cst, res)| if res { None } else { Some(cst) })
+    constant_with_source(lcx, typeck_results, e).and_then(|(c, s)| s.is_local().then_some(c))
 }
 
 pub fn constant_full_int<'tcx>(
@@ -297,29 +318,25 @@ impl Ord for FullInt {
     }
 }
 
-/// Creates a `ConstEvalLateContext` from the given `LateContext` and `TypeckResults`.
-pub fn constant_context<'a, 'tcx>(
-    lcx: &'a LateContext<'tcx>,
-    typeck_results: &'a ty::TypeckResults<'tcx>,
-) -> ConstEvalLateContext<'a, 'tcx> {
-    ConstEvalLateContext {
-        lcx,
-        typeck_results,
-        param_env: lcx.param_env,
-        needed_resolution: false,
-        substs: ty::List::empty(),
-    }
-}
-
 pub struct ConstEvalLateContext<'a, 'tcx> {
     lcx: &'a LateContext<'tcx>,
     typeck_results: &'a ty::TypeckResults<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
-    needed_resolution: bool,
+    source: ConstantSource,
     substs: SubstsRef<'tcx>,
 }
 
 impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
+    fn new(lcx: &'a LateContext<'tcx>, typeck_results: &'a ty::TypeckResults<'tcx>) -> Self {
+        Self {
+            lcx,
+            typeck_results,
+            param_env: lcx.param_env,
+            source: ConstantSource::Local,
+            substs: List::empty(),
+        }
+    }
+
     /// Simple constant folding: Insert an expression, get a constant or none.
     pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant> {
         match e.kind {
@@ -454,11 +471,9 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
                     .const_eval_resolve(self.param_env, mir::UnevaluatedConst::new(def_id, substs), None)
                     .ok()
                     .map(|val| rustc_middle::mir::ConstantKind::from_value(val, ty))?;
-                let result = miri_to_const(self.lcx.tcx, result);
-                if result.is_some() {
-                    self.needed_resolution = true;
-                }
-                result
+                let result = miri_to_const(self.lcx.tcx, result)?;
+                self.source = ConstantSource::Constant;
+                Some(result)
             },
             // FIXME: cover all usable cases.
             _ => None,
@@ -492,8 +507,33 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
 
     /// A block can only yield a constant if it only has one constant expression.
     fn block(&mut self, block: &Block<'_>) -> Option<Constant> {
-        if block.stmts.is_empty() {
-            block.expr.as_ref().and_then(|b| self.expr(b))
+        if block.stmts.is_empty()
+            && let Some(expr) = block.expr
+        {
+            // Try to detect any `cfg`ed statements or empty macro expansions.
+            let span = block.span.data();
+            if span.ctxt == SyntaxContext::root() {
+                if let Some(expr_span) = walk_span_to_context(expr.span, span.ctxt)
+                    && let expr_lo = expr_span.lo()
+                    && expr_lo >= span.lo
+                    && let Some(src) = get_source_text(self.lcx, span.lo..expr_lo)
+                    && let Some(src) = src.as_str()
+                {
+                    use rustc_lexer::TokenKind::{Whitespace, LineComment, BlockComment, Semi, OpenBrace};
+                    if !tokenize(src)
+                        .map(|t| t.kind)
+                        .filter(|t| !matches!(t, Whitespace | LineComment { .. } | BlockComment { .. } | Semi))
+                        .eq([OpenBrace])
+                    {
+                        self.source = ConstantSource::Constant;
+                    }
+                } else {
+                    // Unable to access the source. Assume a non-local dependency.
+                    self.source = ConstantSource::Constant;
+                }
+            }
+
+            self.expr(expr)
         } else {
             None
         }

clippy_utils/src/hir_utils.rs

@@ -1,6 +1,7 @@
 use crate::consts::constant_simple;
 use crate::macros::macro_backtrace;
-use crate::source::snippet_opt;
+use crate::source::{get_source_text, snippet_opt, walk_span_to_context, SpanRange};
+use crate::tokenize_with_text;
 use rustc_ast::ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxHasher;
 use rustc_hir::def::Res;
@@ -13,8 +14,9 @@ use rustc_hir::{
 use rustc_lexer::{tokenize, TokenKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty::TypeckResults;
-use rustc_span::{sym, Symbol};
+use rustc_span::{sym, BytePos, ExpnKind, MacroKind, Symbol, SyntaxContext};
 use std::hash::{Hash, Hasher};
+use std::ops::Range;
 
 /// Callback that is called when two expressions are not equal in the sense of `SpanlessEq`, but
 /// other conditions would make them equal.
@@ -65,6 +67,8 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
     pub fn inter_expr(&mut self) -> HirEqInterExpr<'_, 'a, 'tcx> {
         HirEqInterExpr {
             inner: self,
+            left_ctxt: SyntaxContext::root(),
+            right_ctxt: SyntaxContext::root(),
             locals: HirIdMap::default(),
         }
     }
@@ -92,6 +96,8 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
 
 pub struct HirEqInterExpr<'a, 'b, 'tcx> {
     inner: &'a mut SpanlessEq<'b, 'tcx>,
+    left_ctxt: SyntaxContext,
+    right_ctxt: SyntaxContext,
 
     // When binding are declared, the binding ID in the left expression is mapped to the one on the
     // right. For example, when comparing `{ let x = 1; x + 2 }` and `{ let y = 1; y + 2 }`,
@@ -126,52 +132,88 @@ impl HirEqInterExpr<'_, '_, '_> {
     }
 
     /// Checks whether two blocks are the same.
+    #[expect(clippy::similar_names)]
     fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
-        match (left.stmts, left.expr, right.stmts, right.expr) {
-            ([], None, [], None) => {
-                // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
-                // expanded to nothing, or the cfg attribute was used.
-                let (Some(left), Some(right)) = (
-                    snippet_opt(self.inner.cx, left.span),
-                    snippet_opt(self.inner.cx, right.span),
-                ) else { return true };
-                let mut left_pos = 0;
-                let left = tokenize(&left)
-                    .map(|t| {
-                        let end = left_pos + t.len as usize;
-                        let s = &left[left_pos..end];
-                        left_pos = end;
-                        (t, s)
-                    })
-                    .filter(|(t, _)| {
-                        !matches!(
-                            t.kind,
-                            TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
-                        )
-                    })
-                    .map(|(_, s)| s);
-                let mut right_pos = 0;
-                let right = tokenize(&right)
-                    .map(|t| {
-                        let end = right_pos + t.len as usize;
-                        let s = &right[right_pos..end];
-                        right_pos = end;
-                        (t, s)
-                    })
-                    .filter(|(t, _)| {
-                        !matches!(
-                            t.kind,
-                            TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
-                        )
-                    })
-                    .map(|(_, s)| s);
-                left.eq(right)
-            },
-            _ => {
-                over(left.stmts, right.stmts, |l, r| self.eq_stmt(l, r))
-                    && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
-            },
+        use TokenKind::{BlockComment, LineComment, Semi, Whitespace};
+        if left.stmts.len() != right.stmts.len() {
+            return false;
         }
+        let lspan = left.span.data();
+        let rspan = right.span.data();
+        if lspan.ctxt != SyntaxContext::root() && rspan.ctxt != SyntaxContext::root() {
+            // Don't try to check in between statements inside macros.
+            return over(left.stmts, right.stmts, |left, right| self.eq_stmt(left, right))
+                && both(&left.expr, &right.expr, |left, right| self.eq_expr(left, right));
+        }
+        if lspan.ctxt != rspan.ctxt {
+            return false;
+        }
+
+        let mut lstart = lspan.lo;
+        let mut rstart = rspan.lo;
+
+        for (left, right) in left.stmts.iter().zip(right.stmts) {
+            if !self.eq_stmt(left, right) {
+                return false;
+            }
+
+            // Try to detect any `cfg`ed statements or empty macro expansions.
+            let Some(lstmt_span) = walk_span_to_context(left.span, lspan.ctxt) else {
+                return false;
+            };
+            let Some(rstmt_span) = walk_span_to_context(right.span, rspan.ctxt) else {
+                return false;
+            };
+            let lstmt_span = lstmt_span.data();
+            let rstmt_span = rstmt_span.data();
+
+            if lstmt_span.lo < lstart && rstmt_span.lo < rstart {
+                // Can happen when macros expand to multiple statements, or rearrange statements.
+                // Nothing in between the statements to check in this case.
+                continue;
+            }
+            if lstmt_span.lo < lstart || rstmt_span.lo < rstart {
+                // Only one of the blocks had a weird macro.
+                return false;
+            }
+            if !eq_span_tokens(self.inner.cx, lstart..lstmt_span.lo, rstart..rstmt_span.lo, |t| {
+                !matches!(t, Whitespace | LineComment { .. } | BlockComment { .. } | Semi)
+            }) {
+                return false;
+            }
+
+            lstart = lstmt_span.hi;
+            rstart = rstmt_span.hi;
+        }
+
+        let (lend, rend) = match (left.expr, right.expr) {
+            (Some(left), Some(right)) => {
+                if !self.eq_expr(left, right) {
+                    return false;
+                }
+                let Some(lexpr_span) = walk_span_to_context(left.span, lspan.ctxt) else {
+                    return false;
+                };
+                let Some(rexpr_span) = walk_span_to_context(right.span, rspan.ctxt) else {
+                    return false;
+                };
+                (lexpr_span.lo(), rexpr_span.lo())
+            },
+            (None, None) => (lspan.hi, rspan.hi),
+            (Some(_), None) | (None, Some(_)) => return false,
+        };
+
+        if lend < lstart && rend < rstart {
+            // Can happen when macros rearrange the input.
+            // Nothing in between the statements to check in this case.
+            return true;
+        } else if lend < lstart || rend < rstart {
+            // Only one of the blocks had a weird macro
+            return false;
+        }
+        eq_span_tokens(self.inner.cx, lstart..lend, rstart..rend, |t| {
+            !matches!(t, Whitespace | LineComment { .. } | BlockComment { .. } | Semi)
+        })
     }
 
     fn should_ignore(&mut self, expr: &Expr<'_>) -> bool {
@@ -207,7 +249,7 @@ impl HirEqInterExpr<'_, '_, '_> {
 
     #[expect(clippy::similar_names)]
     pub fn eq_expr(&mut self, left: &Expr<'_>, right: &Expr<'_>) -> bool {
-        if !self.inner.allow_side_effects && left.span.ctxt() != right.span.ctxt() {
+        if !self.check_ctxt(left.span.ctxt(), right.span.ctxt()) {
             return false;
         }
 
@@ -440,6 +482,45 @@ impl HirEqInterExpr<'_, '_, '_> {
     fn eq_type_binding(&mut self, left: &TypeBinding<'_>, right: &TypeBinding<'_>) -> bool {
         left.ident.name == right.ident.name && self.eq_ty(left.ty(), right.ty())
     }
+
+    fn check_ctxt(&mut self, left: SyntaxContext, right: SyntaxContext) -> bool {
+        if self.left_ctxt == left && self.right_ctxt == right {
+            return true;
+        } else if self.left_ctxt == left || self.right_ctxt == right {
+            // Only one context has changed. This can only happen if the two nodes are written differently.
+            return false;
+        } else if left != SyntaxContext::root() {
+            let mut left_data = left.outer_expn_data();
+            let mut right_data = right.outer_expn_data();
+            loop {
+                use TokenKind::{BlockComment, LineComment, Whitespace};
+                if left_data.macro_def_id != right_data.macro_def_id
+                    || (matches!(left_data.kind, ExpnKind::Macro(MacroKind::Bang, name) if name == sym::cfg)
+                        && !eq_span_tokens(self.inner.cx, left_data.call_site, right_data.call_site, |t| {
+                            !matches!(t, Whitespace | LineComment { .. } | BlockComment { .. })
+                        }))
+                {
+                    // Either a different chain of macro calls, or different arguments to the `cfg` macro.
+                    return false;
+                }
+                let left_ctxt = left_data.call_site.ctxt();
+                let right_ctxt = right_data.call_site.ctxt();
+                if left_ctxt == SyntaxContext::root() && right_ctxt == SyntaxContext::root() {
+                    break;
+                }
+                if left_ctxt == SyntaxContext::root() || right_ctxt == SyntaxContext::root() {
+                    // Different lengths for the expansion stack. This can only happen if nodes are written differently,
+                    // or shouldn't be compared to start with.
+                    return false;
+                }
+                left_data = left_ctxt.outer_expn_data();
+                right_data = right_ctxt.outer_expn_data();
+            }
+        }
+        self.left_ctxt = left;
+        self.right_ctxt = right;
+        true
+    }
 }
 
 /// Some simple reductions like `{ return }` => `return`
@@ -1038,3 +1119,34 @@ pub fn hash_expr(cx: &LateContext<'_>, e: &Expr<'_>) -> u64 {
     h.hash_expr(e);
     h.finish()
 }
+
+#[expect(clippy::similar_names)]
+fn eq_span_tokens(
+    cx: &LateContext<'_>,
+    left: impl SpanRange,
+    right: impl SpanRange,
+    pred: impl Fn(TokenKind) -> bool,
+) -> bool {
+    fn f(cx: &LateContext<'_>, left: Range<BytePos>, right: Range<BytePos>, pred: impl Fn(TokenKind) -> bool) -> bool {
+        if let Some(lsrc) = get_source_text(cx, left)
+            && let Some(lsrc) = lsrc.as_str()
+            && let Some(rsrc) = get_source_text(cx, right)
+            && let Some(rsrc) = rsrc.as_str()
+        {
+            let pred = |t: &(_, _)| pred(t.0);
+            let map = |(_, x)| x;
+
+            let ltok = tokenize_with_text(lsrc)
+                .filter(pred)
+                .map(map);
+            let rtok = tokenize_with_text(rsrc)
+                .filter(pred)
+                .map(map);
+            ltok.eq(rtok)
+        } else {
+            // Unable to access the source. Conservatively assume the blocks aren't equal.
+            false
+        }
+    }
+    f(cx, left.into_range(), right.into_range(), pred)
+}

clippy_utils/src/lib.rs

@@ -1,5 +1,6 @@
 #![feature(array_chunks)]
 #![feature(box_patterns)]
+#![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(lint_reasons)]
 #![feature(never_type)]
@@ -76,6 +77,7 @@ use std::sync::OnceLock;
 use std::sync::{Mutex, MutexGuard};
 
 use if_chain::if_chain;
+use itertools::Itertools;
 use rustc_ast::ast::{self, LitKind, RangeLimits};
 use rustc_ast::Attribute;
 use rustc_data_structures::fx::FxHashMap;
@@ -282,6 +284,15 @@ pub fn is_wild(pat: &Pat<'_>) -> bool {
     matches!(pat.kind, PatKind::Wild)
 }
 
+/// Checks if the given `QPath` belongs to a type alias.
+pub fn is_ty_alias(qpath: &QPath<'_>) -> bool {
+    match *qpath {
+        QPath::Resolved(_, path) => matches!(path.res, Res::Def(DefKind::TyAlias, ..)),
+        QPath::TypeRelative(ty, _) if let TyKind::Path(qpath) = ty.kind => { is_ty_alias(&qpath) },
+        _ => false,
+    }
+}
+
 /// Checks if the method call given in `expr` belongs to the given trait.
 /// This is a deprecated function, consider using [`is_trait_method`].
 pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool {
@@ -1488,7 +1499,7 @@ pub fn is_range_full(cx: &LateContext<'_>, expr: &Expr<'_>, container_path: Opti
                 && let const_val = cx.tcx.valtree_to_const_val((bnd_ty, min_val.to_valtree()))
                 && let min_const_kind = ConstantKind::from_value(const_val, bnd_ty)
                 && let Some(min_const) = miri_to_const(cx.tcx, min_const_kind)
-                && let Some((start_const, _)) = constant(cx, cx.typeck_results(), start)
+                && let Some(start_const) = constant(cx, cx.typeck_results(), start)
             {
                 start_const == min_const
             } else {
@@ -1504,7 +1515,7 @@ pub fn is_range_full(cx: &LateContext<'_>, expr: &Expr<'_>, container_path: Opti
                         && let const_val = cx.tcx.valtree_to_const_val((bnd_ty, max_val.to_valtree()))
                         && let max_const_kind = ConstantKind::from_value(const_val, bnd_ty)
                         && let Some(max_const) = miri_to_const(cx.tcx, max_const_kind)
-                        && let Some((end_const, _)) = constant(cx, cx.typeck_results(), end)
+                        && let Some(end_const) = constant(cx, cx.typeck_results(), end)
                     {
                         end_const == max_const
                     } else {
@@ -1536,7 +1547,7 @@ pub fn is_integer_const(cx: &LateContext<'_>, e: &Expr<'_>, value: u128) -> bool
         return true;
     }
     let enclosing_body = cx.tcx.hir().enclosing_body_owner(e.hir_id);
-    if let Some((Constant::Int(v), _)) = constant(cx, cx.tcx.typeck(enclosing_body), e) {
+    if let Some(Constant::Int(v)) = constant(cx, cx.tcx.typeck(enclosing_body), e) {
         return value == v;
     }
     false
@@ -2480,6 +2491,17 @@ pub fn walk_to_expr_usage<'tcx, T>(
     None
 }
 
+/// Tokenizes the input while keeping the text associated with each token.
+pub fn tokenize_with_text(s: &str) -> impl Iterator<Item = (TokenKind, &str)> {
+    let mut pos = 0;
+    tokenize(s).map(move |t| {
+        let end = pos + t.len;
+        let range = pos as usize..end as usize;
+        pos = end;
+        (t.kind, s.get(range).unwrap_or_default())
+    })
+}
+
 /// Checks whether a given span has any comment token
 /// This checks for all types of comment: line "//", block "/**", doc "///" "//!"
 pub fn span_contains_comment(sm: &SourceMap, span: Span) -> bool {
@@ -2496,23 +2518,11 @@ pub fn span_contains_comment(sm: &SourceMap, span: Span) -> bool {
 /// Comments are returned wrapped with their relevant delimiters
 pub fn span_extract_comment(sm: &SourceMap, span: Span) -> String {
     let snippet = sm.span_to_snippet(span).unwrap_or_default();
-    let mut comments_buf: Vec<String> = Vec::new();
-    let mut index: usize = 0;
-
-    for token in tokenize(&snippet) {
-        let token_range = index..(index + token.len as usize);
-        index += token.len as usize;
-        match token.kind {
-            TokenKind::BlockComment { .. } | TokenKind::LineComment { .. } => {
-                if let Some(comment) = snippet.get(token_range) {
-                    comments_buf.push(comment.to_string());
-                }
-            },
-            _ => (),
-        }
-    }
-
-    comments_buf.join("\n")
+    let res = tokenize_with_text(&snippet)
+        .filter(|(t, _)| matches!(t, TokenKind::BlockComment { .. } | TokenKind::LineComment { .. }))
+        .map(|(_, s)| s)
+        .join("\n");
+    res
 }
 
 pub fn span_find_starting_semi(sm: &SourceMap, span: Span) -> Span {

clippy_utils/src/source.rs

@@ -2,14 +2,64 @@
 
 #![allow(clippy::module_name_repetitions)]
 
+use rustc_data_structures::sync::Lrc;
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LintContext};
 use rustc_session::Session;
-use rustc_span::hygiene;
 use rustc_span::source_map::{original_sp, SourceMap};
+use rustc_span::{hygiene, SourceFile};
 use rustc_span::{BytePos, Pos, Span, SpanData, SyntaxContext, DUMMY_SP};
 use std::borrow::Cow;
+use std::ops::Range;
+
+/// A type which can be converted to the range portion of a `Span`.
+pub trait SpanRange {
+    fn into_range(self) -> Range<BytePos>;
+}
+impl SpanRange for Span {
+    fn into_range(self) -> Range<BytePos> {
+        let data = self.data();
+        data.lo..data.hi
+    }
+}
+impl SpanRange for SpanData {
+    fn into_range(self) -> Range<BytePos> {
+        self.lo..self.hi
+    }
+}
+impl SpanRange for Range<BytePos> {
+    fn into_range(self) -> Range<BytePos> {
+        self
+    }
+}
+
+pub struct SourceFileRange {
+    pub sf: Lrc<SourceFile>,
+    pub range: Range<usize>,
+}
+impl SourceFileRange {
+    /// Attempts to get the text from the source file. This can fail if the source text isn't
+    /// loaded.
+    pub fn as_str(&self) -> Option<&str> {
+        self.sf.src.as_ref().and_then(|x| x.get(self.range.clone()))
+    }
+}
+
+/// Gets the source file, and range in the file, of the given span. Returns `None` if the span
+/// extends through multiple files, or is malformed.
+pub fn get_source_text(cx: &impl LintContext, sp: impl SpanRange) -> Option<SourceFileRange> {
+    fn f(sm: &SourceMap, sp: Range<BytePos>) -> Option<SourceFileRange> {
+        let start = sm.lookup_byte_offset(sp.start);
+        let end = sm.lookup_byte_offset(sp.end);
+        if !Lrc::ptr_eq(&start.sf, &end.sf) || start.pos > end.pos {
+            return None;
+        }
+        let range = start.pos.to_usize()..end.pos.to_usize();
+        Some(SourceFileRange { sf: start.sf, range })
+    }
+    f(cx.sess().source_map(), sp.into_range())
+}
 
 /// Like `snippet_block`, but add braces if the expr is not an `ExprKind::Block`.
 pub fn expr_block<T: LintContext>(

rust-toolchain

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2023-05-05"
+channel = "nightly-2023-05-20"
 components = ["cargo", "llvm-tools", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]

tests/ui-internal/custom_ice_message.rs

@@ -3,6 +3,7 @@
 //@normalize-stderr-test: "produce_ice.rs:\d*:\d*" -> "produce_ice.rs"
 //@normalize-stderr-test: "', .*clippy_lints" -> "', clippy_lints"
 //@normalize-stderr-test: "'rustc'" -> "'<unnamed>'"
+//@normalize-stderr-test: "running on .*" -> "running on <target>"
 //@normalize-stderr-test: "(?ms)query stack during panic:\n.*end of query stack\n" -> ""
 
 #![deny(clippy::internal)]

tests/ui-internal/custom_ice_message.stderr

@@ -1,12 +1,14 @@
 thread '<unnamed>' panicked at 'Would you like some help with that?', clippy_lints/src/utils/internal_lints/produce_ice.rs
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 
-error: internal compiler error: unexpected panic
-
-note: the compiler unexpectedly panicked. this is a bug.
+error: the compiler unexpectedly panicked. this is a bug.
 
 note: we would appreciate a bug report: https://github.com/rust-lang/rust-clippy/issues/new
 
+note: rustc 1.71.0-nightly (521f4dae1 2023-05-19) running on <target>
+
+note: compiler flags: -C prefer-dynamic -Z ui-testing
+
 note: Clippy version: foo
 
 thread panicked while panicking. aborting.

tests/ui/arithmetic_side_effects.rs

@@ -458,4 +458,12 @@ pub fn issue_10583(a: u16) -> u16 {
     10 / a
 }
 
+pub fn issue_10767() {
+    let n = &1.0;
+    n + n;
+    3.1_f32 + &1.2_f32;
+    &3.4_f32 + 1.5_f32;
+    &3.5_f32 + &1.3_f32;
+}
+
 fn main() {}

tests/ui/borrow_deref_ref.fixed

@@ -1,7 +1,11 @@
 //@run-rustfix
+//@aux-build: proc_macros.rs
 
 #![allow(dead_code, unused_variables)]
 
+extern crate proc_macros;
+use proc_macros::with_span;
+
 fn main() {}
 
 mod should_lint {
@@ -47,6 +51,17 @@ mod should_not_lint2 {
     }
 }
 
+with_span!(
+    span
+
+    fn just_returning(x: &u32) -> &u32 {
+        x
+    }
+
+    fn dont_lint_proc_macro() {
+        let a = &mut &*just_returning(&12);
+    }
+);
 // this mod explains why we should not lint `& &* (&T)`
 mod false_negative {
     fn foo() {

tests/ui/borrow_deref_ref.rs

@@ -1,7 +1,11 @@
 //@run-rustfix
+//@aux-build: proc_macros.rs
 
 #![allow(dead_code, unused_variables)]
 
+extern crate proc_macros;
+use proc_macros::with_span;
+
 fn main() {}
 
 mod should_lint {
@@ -47,6 +51,17 @@ mod should_not_lint2 {
     }
 }
 
+with_span!(
+    span
+
+    fn just_returning(x: &u32) -> &u32 {
+        x
+    }
+
+    fn dont_lint_proc_macro() {
+        let a = &mut &*just_returning(&12);
+    }
+);
 // this mod explains why we should not lint `& &* (&T)`
 mod false_negative {
     fn foo() {

tests/ui/borrow_deref_ref.stderr

@@ -1,5 +1,5 @@
 error: deref on an immutable reference
-  --> $DIR/borrow_deref_ref.rs:10:17
+  --> $DIR/borrow_deref_ref.rs:14:17
    |
 LL |         let b = &*a;
    |                 ^^^ help: if you would like to reborrow, try removing `&*`: `a`
@@ -7,13 +7,13 @@ LL |         let b = &*a;
    = note: `-D clippy::borrow-deref-ref` implied by `-D warnings`
 
 error: deref on an immutable reference
-  --> $DIR/borrow_deref_ref.rs:12:22
+  --> $DIR/borrow_deref_ref.rs:16:22
    |
 LL |         let b = &mut &*bar(&12);
    |                      ^^^^^^^^^^ help: if you would like to reborrow, try removing `&*`: `bar(&12)`
 
 error: deref on an immutable reference
-  --> $DIR/borrow_deref_ref.rs:55:23
+  --> $DIR/borrow_deref_ref.rs:70:23
    |
 LL |         let addr_y = &&*x as *const _ as usize; // assert ok
    |                       ^^^ help: if you would like to reborrow, try removing `&*`: `x`

tests/ui/box_default.fixed

@@ -35,6 +35,13 @@ fn main() {
     let _more = ret_ty_fn();
     call_ty_fn(Box::default());
     issue_10381();
+
+    // `Box::<Option<_>>::default()` would be valid here, but not `Box::default()` or
+    // `Box::<Option<[closure@...]>::default()`
+    //
+    // Would have a suggestion after https://github.com/rust-lang/rust/blob/fdd030127cc68afec44a8d3f6341525dd34e50ae/compiler/rustc_middle/src/ty/diagnostics.rs#L554-L563
+    let mut unnameable = Box::new(Option::default());
+    let _ = unnameable.insert(|| {});
 }
 
 fn ret_ty_fn() -> Box<bool> {

tests/ui/box_default.rs

@@ -35,6 +35,13 @@ fn main() {
     let _more = ret_ty_fn();
     call_ty_fn(Box::new(u8::default()));
     issue_10381();
+
+    // `Box::<Option<_>>::default()` would be valid here, but not `Box::default()` or
+    // `Box::<Option<[closure@...]>::default()`
+    //
+    // Would have a suggestion after https://github.com/rust-lang/rust/blob/fdd030127cc68afec44a8d3f6341525dd34e50ae/compiler/rustc_middle/src/ty/diagnostics.rs#L554-L563
+    let mut unnameable = Box::new(Option::default());
+    let _ = unnameable.insert(|| {});
 }
 
 fn ret_ty_fn() -> Box<bool> {

tests/ui/box_default.stderr

@@ -73,25 +73,25 @@ LL |     call_ty_fn(Box::new(u8::default()));
    |                ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Box::default()`
 
 error: `Box::new(_)` of default value
-  --> $DIR/box_default.rs:41:5
+  --> $DIR/box_default.rs:48:5
    |
 LL |     Box::new(bool::default())
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Box::<bool>::default()`
 
 error: `Box::new(_)` of default value
-  --> $DIR/box_default.rs:58:28
+  --> $DIR/box_default.rs:65:28
    |
 LL |     let _: Box<dyn Read> = Box::new(ImplementsDefault::default());
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Box::<ImplementsDefault>::default()`
 
 error: `Box::new(_)` of default value
-  --> $DIR/box_default.rs:67:17
+  --> $DIR/box_default.rs:74:17
    |
 LL |         let _ = Box::new(WeirdPathed::default());
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Box::<WeirdPathed>::default()`
 
 error: `Box::new(_)` of default value
-  --> $DIR/box_default.rs:79:18
+  --> $DIR/box_default.rs:86:18
    |
 LL |             Some(Box::new(Foo::default()))
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Box::<Foo>::default()`

tests/ui/collapsible_if.fixed

@@ -1,5 +1,10 @@
 //@run-rustfix
-#![allow(clippy::assertions_on_constants, clippy::equatable_if_let)]
+#![allow(
+    clippy::assertions_on_constants,
+    clippy::equatable_if_let,
+    clippy::nonminimal_bool,
+    clippy::eq_op
+)]
 
 #[rustfmt::skip]
 #[warn(clippy::collapsible_if)]

tests/ui/collapsible_if.rs

@@ -1,5 +1,10 @@
 //@run-rustfix
-#![allow(clippy::assertions_on_constants, clippy::equatable_if_let)]
+#![allow(
+    clippy::assertions_on_constants,
+    clippy::equatable_if_let,
+    clippy::nonminimal_bool,
+    clippy::eq_op
+)]
 
 #[rustfmt::skip]
 #[warn(clippy::collapsible_if)]

tests/ui/collapsible_if.stderr

@@ -1,5 +1,5 @@
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:9:5
+  --> $DIR/collapsible_if.rs:14:5
    |
 LL | /     if x == "hello" {
 LL | |         if y == "world" {
@@ -17,7 +17,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:15:5
+  --> $DIR/collapsible_if.rs:20:5
    |
 LL | /     if x == "hello" || x == "world" {
 LL | |         if y == "world" || y == "hello" {
@@ -34,7 +34,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:21:5
+  --> $DIR/collapsible_if.rs:26:5
    |
 LL | /     if x == "hello" && x == "world" {
 LL | |         if y == "world" || y == "hello" {
@@ -51,7 +51,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:27:5
+  --> $DIR/collapsible_if.rs:32:5
    |
 LL | /     if x == "hello" || x == "world" {
 LL | |         if y == "world" && y == "hello" {
@@ -68,7 +68,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:33:5
+  --> $DIR/collapsible_if.rs:38:5
    |
 LL | /     if x == "hello" && x == "world" {
 LL | |         if y == "world" && y == "hello" {
@@ -85,7 +85,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:39:5
+  --> $DIR/collapsible_if.rs:44:5
    |
 LL | /     if 42 == 1337 {
 LL | |         if 'a' != 'A' {
@@ -102,7 +102,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:95:5
+  --> $DIR/collapsible_if.rs:100:5
    |
 LL | /     if x == "hello" {
 LL | |         if y == "world" { // Collapsible
@@ -119,7 +119,7 @@ LL +     }
    |
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:154:5
+  --> $DIR/collapsible_if.rs:159:5
    |
 LL | /     if matches!(true, true) {
 LL | |         if matches!(true, true) {}
@@ -127,7 +127,7 @@ LL | |     }
    | |_____^ help: collapse nested if block: `if matches!(true, true) && matches!(true, true) {}`
 
 error: this `if` statement can be collapsed
-  --> $DIR/collapsible_if.rs:159:5
+  --> $DIR/collapsible_if.rs:164:5
    |
 LL | /     if matches!(true, true) && truth() {
 LL | |         if matches!(true, true) {}

tests/ui/dbg_macro.rs

@@ -4,6 +4,7 @@
 fn foo(n: u32) -> u32 {
     if let Some(n) = dbg!(n.checked_sub(4)) { n } else { n }
 }
+fn bar(_: ()) {}
 
 fn factorial(n: u32) -> u32 {
     if dbg!(n <= 1) {
@@ -21,6 +22,32 @@ fn main() {
     dbg!(1, 2, 3, 4, 5);
 }
 
+fn issue9914() {
+    macro_rules! foo {
+        ($x:expr) => {
+            $x;
+        };
+    }
+    macro_rules! foo2 {
+        ($x:expr) => {
+            $x;
+        };
+    }
+    macro_rules! expand_to_dbg {
+        () => {
+            dbg!();
+        };
+    }
+
+    dbg!();
+    #[allow(clippy::let_unit_value)]
+    let _ = dbg!();
+    bar(dbg!());
+    foo!(dbg!());
+    foo2!(foo!(dbg!()));
+    expand_to_dbg!();
+}
+
 mod issue7274 {
     trait Thing<'b> {
         fn foo(&self);

tests/ui/dbg_macro.stderr

@@ -11,7 +11,7 @@ LL |     if let Some(n) = n.checked_sub(4) { n } else { n }
    |                      ~~~~~~~~~~~~~~~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:9:8
+  --> $DIR/dbg_macro.rs:10:8
    |
 LL |     if dbg!(n <= 1) {
    |        ^^^^^^^^^^^^
@@ -22,7 +22,7 @@ LL |     if n <= 1 {
    |        ~~~~~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:10:9
+  --> $DIR/dbg_macro.rs:11:9
    |
 LL |         dbg!(1)
    |         ^^^^^^^
@@ -33,7 +33,7 @@ LL |         1
    |
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:12:9
+  --> $DIR/dbg_macro.rs:13:9
    |
 LL |         dbg!(n * factorial(n - 1))
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -44,7 +44,7 @@ LL |         n * factorial(n - 1)
    |
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:17:5
+  --> $DIR/dbg_macro.rs:18:5
    |
 LL |     dbg!(42);
    |     ^^^^^^^^
@@ -55,7 +55,7 @@ LL |     42;
    |     ~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:18:5
+  --> $DIR/dbg_macro.rs:19:5
    |
 LL |     dbg!(dbg!(dbg!(42)));
    |     ^^^^^^^^^^^^^^^^^^^^
@@ -66,7 +66,7 @@ LL |     dbg!(dbg!(42));
    |     ~~~~~~~~~~~~~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:19:14
+  --> $DIR/dbg_macro.rs:20:14
    |
 LL |     foo(3) + dbg!(factorial(4));
    |              ^^^^^^^^^^^^^^^^^^
@@ -77,7 +77,7 @@ LL |     foo(3) + factorial(4);
    |              ~~~~~~~~~~~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:20:5
+  --> $DIR/dbg_macro.rs:21:5
    |
 LL |     dbg!(1, 2, dbg!(3, 4));
    |     ^^^^^^^^^^^^^^^^^^^^^^
@@ -88,7 +88,7 @@ LL |     (1, 2, dbg!(3, 4));
    |     ~~~~~~~~~~~~~~~~~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:21:5
+  --> $DIR/dbg_macro.rs:22:5
    |
 LL |     dbg!(1, 2, 3, 4, 5);
    |     ^^^^^^^^^^^^^^^^^^^
@@ -99,7 +99,63 @@ LL |     (1, 2, 3, 4, 5);
    |     ~~~~~~~~~~~~~~~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:41:9
+  --> $DIR/dbg_macro.rs:42:5
+   |
+LL |     dbg!();
+   |     ^^^^^^^
+   |
+help: remove the invocation before committing it to a version control system
+   |
+LL -     dbg!();
+LL +     
+   |
+
+error: the `dbg!` macro is intended as a debugging tool
+  --> $DIR/dbg_macro.rs:44:13
+   |
+LL |     let _ = dbg!();
+   |             ^^^^^^
+   |
+help: remove the invocation before committing it to a version control system
+   |
+LL |     let _ = ();
+   |             ~~
+
+error: the `dbg!` macro is intended as a debugging tool
+  --> $DIR/dbg_macro.rs:45:9
+   |
+LL |     bar(dbg!());
+   |         ^^^^^^
+   |
+help: remove the invocation before committing it to a version control system
+   |
+LL |     bar(());
+   |         ~~
+
+error: the `dbg!` macro is intended as a debugging tool
+  --> $DIR/dbg_macro.rs:46:10
+   |
+LL |     foo!(dbg!());
+   |          ^^^^^^
+   |
+help: remove the invocation before committing it to a version control system
+   |
+LL |     foo!(());
+   |          ~~
+
+error: the `dbg!` macro is intended as a debugging tool
+  --> $DIR/dbg_macro.rs:47:16
+   |
+LL |     foo2!(foo!(dbg!()));
+   |                ^^^^^^
+   |
+help: remove the invocation before committing it to a version control system
+   |
+LL |     foo2!(foo!(()));
+   |                ~~
+
+error: the `dbg!` macro is intended as a debugging tool
+  --> $DIR/dbg_macro.rs:68:9
    |
 LL |         dbg!(2);
    |         ^^^^^^^
@@ -110,7 +166,7 @@ LL |         2;
    |         ~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:47:5
+  --> $DIR/dbg_macro.rs:74:5
    |
 LL |     dbg!(1);
    |     ^^^^^^^
@@ -121,7 +177,7 @@ LL |     1;
    |     ~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:52:5
+  --> $DIR/dbg_macro.rs:79:5
    |
 LL |     dbg!(1);
    |     ^^^^^^^
@@ -132,7 +188,7 @@ LL |     1;
    |     ~
 
 error: the `dbg!` macro is intended as a debugging tool
-  --> $DIR/dbg_macro.rs:58:9
+  --> $DIR/dbg_macro.rs:85:9
    |
 LL |         dbg!(1);
    |         ^^^^^^^
@@ -142,5 +198,5 @@ help: remove the invocation before committing it to a version control system
 LL |         1;
    |         ~
 
-error: aborting due to 13 previous errors
+error: aborting due to 18 previous errors
 

tests/ui/default_constructed_unit_structs.fixed

@@ -105,6 +105,7 @@ fn main() {
     // should lint
     let _ = PhantomData::<usize>;
     let _: PhantomData<i32> = PhantomData;
+    let _: PhantomData<i32> = std::marker::PhantomData;
     let _ = UnitStruct;
 
     // should not lint
@@ -116,4 +117,21 @@ fn main() {
     let _ = EmptyStruct::default();
     let _ = FakeDefault::default();
     let _ = <FakeDefault as Default>::default();
+
+    macro_rules! in_macro {
+        ($i:ident) => {{
+            let _ = UnitStruct::default();
+            let _ = $i::default();
+        }};
+    }
+
+    in_macro!(UnitStruct);
+
+    macro_rules! struct_from_macro {
+        () => {
+            UnitStruct
+        };
+    }
+
+    let _ = <struct_from_macro!()>::default();
 }

tests/ui/default_constructed_unit_structs.rs

@@ -105,6 +105,7 @@ fn main() {
     // should lint
     let _ = PhantomData::<usize>::default();
     let _: PhantomData<i32> = PhantomData::default();
+    let _: PhantomData<i32> = std::marker::PhantomData::default();
     let _ = UnitStruct::default();
 
     // should not lint
@@ -116,4 +117,21 @@ fn main() {
     let _ = EmptyStruct::default();
     let _ = FakeDefault::default();
     let _ = <FakeDefault as Default>::default();
+
+    macro_rules! in_macro {
+        ($i:ident) => {{
+            let _ = UnitStruct::default();
+            let _ = $i::default();
+        }};
+    }
+
+    in_macro!(UnitStruct);
+
+    macro_rules! struct_from_macro {
+        () => {
+            UnitStruct
+        };
+    }
+
+    let _ = <struct_from_macro!()>::default();
 }

tests/ui/default_constructed_unit_structs.stderr

@@ -25,10 +25,16 @@ LL |     let _: PhantomData<i32> = PhantomData::default();
    |                                          ^^^^^^^^^^^ help: remove this call to `default`
 
 error: use of `default` to create a unit struct
-  --> $DIR/default_constructed_unit_structs.rs:108:23
+  --> $DIR/default_constructed_unit_structs.rs:108:55
+   |
+LL |     let _: PhantomData<i32> = std::marker::PhantomData::default();
+   |                                                       ^^^^^^^^^^^ help: remove this call to `default`
+
+error: use of `default` to create a unit struct
+  --> $DIR/default_constructed_unit_structs.rs:109:23
    |
 LL |     let _ = UnitStruct::default();
    |                       ^^^^^^^^^^^ help: remove this call to `default`
 
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors
 

tests/ui/empty_line_after_doc_comments.rs

@@ -0,0 +1,132 @@
+//@aux-build:proc_macro_attr.rs
+#![warn(clippy::empty_line_after_doc_comments)]
+#![allow(clippy::assertions_on_constants)]
+#![feature(custom_inner_attributes)]
+#![rustfmt::skip]
+
+#[macro_use]
+extern crate proc_macro_attr;
+
+mod some_mod {
+    //! This doc comment should *NOT* produce a warning
+
+    mod some_inner_mod {
+        fn some_noop() {}
+    }
+}
+
+/// This should produce a warning
+
+fn with_doc_and_newline() { assert!(true)}
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+
+/// some comment
+fn with_one_newline_and_comment() { assert!(true) }
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+/// some comment
+fn with_no_newline_and_comment() { assert!(true) }
+
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+
+fn with_one_newline() { assert!(true) }
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+
+
+fn with_two_newlines() { assert!(true) }
+
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+
+enum Baz {
+    One,
+    Two
+}
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+
+struct Foo {
+    one: isize,
+    two: isize
+}
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+
+mod foo {
+}
+
+/// This doc comment should produce a warning
+
+/** This is also a doc comment and should produce a warning
+ */
+
+// This should *NOT* produce a warning
+#[allow(non_camel_case_types)]
+#[allow(missing_docs)]
+#[allow(missing_docs)]
+fn three_attributes() { assert!(true) }
+
+// This should *NOT* produce a warning
+#[doc = "
+Returns the escaped value of the textual representation of
+
+"]
+pub fn function() -> bool {
+    true
+}
+
+// This should *NOT* produce a warning
+#[derive(Clone, Copy)]
+pub enum FooFighter {
+    Bar1,
+
+    Bar2,
+
+    Bar3,
+
+    Bar4
+}
+
+// This should *NOT* produce a warning because the empty line is inside a block comment
+#[crate_type = "lib"]
+/*
+
+*/
+pub struct S;
+
+// This should *NOT* produce a warning
+#[crate_type = "lib"]
+/* test */
+pub struct T;
+
+// This should *NOT* produce a warning
+// See https://github.com/rust-lang/rust-clippy/issues/5567
+#[fake_async_trait]
+pub trait Bazz {
+    fn foo() -> Vec<u8> {
+        let _i = "";
+
+
+
+        vec![]
+    }
+}
+
+#[derive(Clone, Copy)]
+#[dummy(string = "first line
+
+second line
+")]
+pub struct Args;
+
+fn main() {}

tests/ui/empty_line_after_doc_comments.stderr

@@ -0,0 +1,36 @@
+error: found an empty line after a doc comment. Perhaps you need to use `//!` to make a comment on a module, remove the empty line, or make a regular comment with `//`?
+  --> $DIR/empty_line_after_doc_comments.rs:18:1
+   |
+LL | / /// This should produce a warning
+LL | |
+LL | | fn with_doc_and_newline() { assert!(true)}
+   | |_
+   |
+   = note: `-D clippy::empty-line-after-doc-comments` implied by `-D warnings`
+
+error: found an empty line after a doc comment. Perhaps you need to use `//!` to make a comment on a module, remove the empty line, or make a regular comment with `//`?
+  --> $DIR/empty_line_after_doc_comments.rs:68:1
+   |
+LL | / /// This doc comment should produce a warning
+LL | |
+LL | | /** This is also a doc comment and should produce a warning
+LL | |  */
+...  |
+LL | | #[allow(missing_docs)]
+LL | | fn three_attributes() { assert!(true) }
+   | |_
+
+error: found an empty line after a doc comment. Perhaps you need to use `//!` to make a comment on a module, remove the empty line, or make a regular comment with `//`?
+  --> $DIR/empty_line_after_doc_comments.rs:70:1
+   |
+LL | / /** This is also a doc comment and should produce a warning
+LL | |  */
+LL | |
+LL | | // This should *NOT* produce a warning
+...  |
+LL | | #[allow(missing_docs)]
+LL | | fn three_attributes() { assert!(true) }
+   | |_
+
+error: aborting due to 3 previous errors
+

tests/ui/float_arithmetic.rs

@@ -1,4 +1,4 @@
-#![warn(clippy::integer_arithmetic, clippy::float_arithmetic)]
+#![warn(clippy::arithmetic_side_effects, clippy::float_arithmetic)]
 #![allow(
     unused,
     clippy::shadow_reuse,

tests/ui/integer_arithmetic.rs

@@ -1,109 +0,0 @@
-//@aux-build:proc_macro_derive.rs
-
-#![warn(clippy::integer_arithmetic, clippy::float_arithmetic)]
-#![allow(clippy::no_effect, clippy::unnecessary_operation, clippy::op_ref)]
-
-extern crate proc_macro_derive;
-
-#[derive(proc_macro_derive::ShadowDerive)]
-pub struct Nothing;
-
-#[rustfmt::skip]
-fn main() {
-    let mut i = 1i32;
-    let mut var1 = 13i32;
-    let mut var2 = -1i32;
-    1 + i;
-    i * 2;
-    1 %
-    i / 2; // no error, this is part of the expression in the preceding line
-    i - 2 + 2 - i;
-    -i;
-    i >> 1;
-    i << 1;
-
-    // no error, overflows are checked by `overflowing_literals`
-    -1;
-    -(-1);
-
-    i & 1; // no wrapping
-    i | 1;
-    i ^ 1;
-
-    i += 1;
-    i -= 1;
-    i *= 2;
-    i /= 2;
-    i /= 0;
-    i /= -1;
-    i /= var1;
-    i /= var2;
-    i %= 2;
-    i %= 0;
-    i %= -1;
-    i %= var1;
-    i %= var2;
-    i <<= 3;
-    i >>= 2;
-
-    // no errors
-    i |= 1;
-    i &= 1;
-    i ^= i;
-
-    // No errors for the following items because they are constant expressions
-    enum Foo {
-        Bar = -2,
-    }
-    struct Baz([i32; 1 + 1]);
-    union Qux {
-        field: [i32; 1 + 1],
-    }
-    type Alias = [i32; 1 + 1];
-
-    const FOO: i32 = -2;
-    static BAR: i32 = -2;
-
-    let _: [i32; 1 + 1] = [0, 0];
-
-    let _: [i32; 1 + 1] = {
-        let a: [i32; 1 + 1] = [0, 0];
-        a
-    };
-
-    trait Trait {
-        const ASSOC: i32 = 1 + 1;
-    }
-
-    impl Trait for Foo {
-        const ASSOC: i32 = {
-            let _: [i32; 1 + 1];
-            fn foo() {}
-            1 + 1
-        };
-    }
-}
-
-// warn on references as well! (#5328)
-pub fn int_arith_ref() {
-    3 + &1;
-    &3 + 1;
-    &3 + &1;
-}
-
-pub fn foo(x: &i32) -> i32 {
-    let a = 5;
-    a + x
-}
-
-pub fn bar(x: &i32, y: &i32) -> i32 {
-    x + y
-}
-
-pub fn baz(x: i32, y: &i32) -> i32 {
-    x + y
-}
-
-pub fn qux(x: i32, y: i32) -> i32 {
-    (&x + &y)
-}

tests/ui/integer_arithmetic.stderr

@@ -1,169 +0,0 @@
-error: this operation will panic at runtime
-  --> $DIR/integer_arithmetic.rs:37:5
-   |
-LL |     i /= 0;
-   |     ^^^^^^ attempt to divide `_` by zero
-   |
-   = note: `#[deny(unconditional_panic)]` on by default
-
-error: this operation will panic at runtime
-  --> $DIR/integer_arithmetic.rs:42:5
-   |
-LL |     i %= 0;
-   |     ^^^^^^ attempt to calculate the remainder of `_` with a divisor of zero
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:16:5
-   |
-LL |     1 + i;
-   |     ^^^^^
-   |
-   = note: `-D clippy::integer-arithmetic` implied by `-D warnings`
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:17:5
-   |
-LL |     i * 2;
-   |     ^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:18:5
-   |
-LL | /     1 %
-LL | |     i / 2; // no error, this is part of the expression in the preceding line
-   | |_____^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:20:5
-   |
-LL |     i - 2 + 2 - i;
-   |     ^^^^^^^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:21:5
-   |
-LL |     -i;
-   |     ^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:22:5
-   |
-LL |     i >> 1;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:23:5
-   |
-LL |     i << 1;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:33:5
-   |
-LL |     i += 1;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:34:5
-   |
-LL |     i -= 1;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:35:5
-   |
-LL |     i *= 2;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:38:11
-   |
-LL |     i /= -1;
-   |           ^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:39:5
-   |
-LL |     i /= var1;
-   |     ^^^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:40:5
-   |
-LL |     i /= var2;
-   |     ^^^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:43:11
-   |
-LL |     i %= -1;
-   |           ^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:44:5
-   |
-LL |     i %= var1;
-   |     ^^^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:45:5
-   |
-LL |     i %= var2;
-   |     ^^^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:46:5
-   |
-LL |     i <<= 3;
-   |     ^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:47:5
-   |
-LL |     i >>= 2;
-   |     ^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:89:5
-   |
-LL |     3 + &1;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:90:5
-   |
-LL |     &3 + 1;
-   |     ^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:91:5
-   |
-LL |     &3 + &1;
-   |     ^^^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:96:5
-   |
-LL |     a + x
-   |     ^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:100:5
-   |
-LL |     x + y
-   |     ^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:104:5
-   |
-LL |     x + y
-   |     ^^^^^
-
-error: integer arithmetic detected
-  --> $DIR/integer_arithmetic.rs:108:5
-   |
-LL |     (&x + &y)
-   |     ^^^^^^^^^
-
-error: aborting due to 27 previous errors
-

tests/ui/let_underscore_untyped.rs

@@ -1,6 +1,12 @@
+//@aux-build: proc_macros.rs
+
 #![allow(unused)]
 #![warn(clippy::let_underscore_untyped)]
 
+extern crate proc_macros;
+use proc_macros::with_span;
+
+use clippy_utils::is_from_proc_macro;
 use std::future::Future;
 use std::{boxed::Box, fmt::Display};
 
@@ -32,6 +38,14 @@ fn g() -> impl Fn() {
     || {}
 }
 
+with_span!(
+    span
+
+    fn dont_lint_proc_macro() {
+        let _ = a();
+    }
+);
+
 fn main() {
     let _ = a();
     let _ = b(1);
@@ -40,6 +54,7 @@ fn main() {
     let _ = e();
     let _ = f();
     let _ = g();
+    let closure = || {};
 
     _ = a();
     _ = b(1);

tests/ui/let_underscore_untyped.stderr

@@ -1,60 +1,60 @@
 error: non-binding `let` without a type annotation
-  --> $DIR/let_underscore_untyped.rs:36:5
+  --> $DIR/let_underscore_untyped.rs:50:5
    |
 LL |     let _ = a();
    |     ^^^^^^^^^^^^
    |
 help: consider adding a type annotation
-  --> $DIR/let_underscore_untyped.rs:36:10
+  --> $DIR/let_underscore_untyped.rs:50:10
    |
 LL |     let _ = a();
    |          ^
    = note: `-D clippy::let-underscore-untyped` implied by `-D warnings`
 
 error: non-binding `let` without a type annotation
-  --> $DIR/let_underscore_untyped.rs:37:5
+  --> $DIR/let_underscore_untyped.rs:51:5
    |
 LL |     let _ = b(1);
    |     ^^^^^^^^^^^^^
    |
 help: consider adding a type annotation
-  --> $DIR/let_underscore_untyped.rs:37:10
+  --> $DIR/let_underscore_untyped.rs:51:10
    |
 LL |     let _ = b(1);
    |          ^
 
 error: non-binding `let` without a type annotation
-  --> $DIR/let_underscore_untyped.rs:39:5
+  --> $DIR/let_underscore_untyped.rs:53:5
    |
 LL |     let _ = d(&1);
    |     ^^^^^^^^^^^^^^
    |
 help: consider adding a type annotation
-  --> $DIR/let_underscore_untyped.rs:39:10
+  --> $DIR/let_underscore_untyped.rs:53:10
    |
 LL |     let _ = d(&1);
    |          ^
 
 error: non-binding `let` without a type annotation
-  --> $DIR/let_underscore_untyped.rs:40:5
+  --> $DIR/let_underscore_untyped.rs:54:5
    |
 LL |     let _ = e();
    |     ^^^^^^^^^^^^
    |
 help: consider adding a type annotation
-  --> $DIR/let_underscore_untyped.rs:40:10
+  --> $DIR/let_underscore_untyped.rs:54:10
    |
 LL |     let _ = e();
    |          ^
 
 error: non-binding `let` without a type annotation
-  --> $DIR/let_underscore_untyped.rs:41:5
+  --> $DIR/let_underscore_untyped.rs:55:5
    |
 LL |     let _ = f();
    |     ^^^^^^^^^^^^
    |
 help: consider adding a type annotation
-  --> $DIR/let_underscore_untyped.rs:41:10
+  --> $DIR/let_underscore_untyped.rs:55:10
    |
 LL |     let _ = f();
    |          ^

tests/ui/manual_let_else.rs

@@ -8,6 +8,12 @@
 )]
 #![warn(clippy::manual_let_else)]
 
+enum Variant {
+    A(usize, usize),
+    B(usize),
+    C,
+}
+
 fn g() -> Option<()> {
     None
 }
@@ -135,6 +141,15 @@ fn fire() {
         };
     }
     create_binding_if_some!(w, g());
+
+    fn e() -> Variant {
+        Variant::A(0, 0)
+    }
+
+    // Should not be renamed
+    let v = if let Variant::A(a, 0) = e() { a } else { return };
+    // Should be renamed
+    let v = if let Variant::B(b) = e() { b } else { return };
 }
 
 fn not_fire() {

tests/ui/manual_let_else.stderr

@@ -1,13 +1,13 @@
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:18:5
+  --> $DIR/manual_let_else.rs:24:5
    |
 LL |     let v = if let Some(v_some) = g() { v_some } else { return };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v_some) = g() else { return };`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v) = g() else { return };`
    |
    = note: `-D clippy::manual-let-else` implied by `-D warnings`
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:19:5
+  --> $DIR/manual_let_else.rs:25:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -18,13 +18,13 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         return;
 LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:25:5
+  --> $DIR/manual_let_else.rs:31:5
    |
 LL | /     let v = if let Some(v) = g() {
 LL | |         // Blocks around the identity should have no impact
@@ -45,25 +45,25 @@ LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:38:9
+  --> $DIR/manual_let_else.rs:44:9
    |
 LL |         let v = if let Some(v_some) = g() { v_some } else { continue };
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v_some) = g() else { continue };`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v) = g() else { continue };`
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:39:9
+  --> $DIR/manual_let_else.rs:45:9
    |
 LL |         let v = if let Some(v_some) = g() { v_some } else { break };
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v_some) = g() else { break };`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v) = g() else { break };`
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:43:5
+  --> $DIR/manual_let_else.rs:49:5
    |
 LL |     let v = if let Some(v_some) = g() { v_some } else { panic!() };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v_some) = g() else { panic!() };`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v) = g() else { panic!() };`
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:46:5
+  --> $DIR/manual_let_else.rs:52:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -74,13 +74,13 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         std::process::abort()
 LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:53:5
+  --> $DIR/manual_let_else.rs:59:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -91,13 +91,13 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         if true { return } else { panic!() }
 LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:60:5
+  --> $DIR/manual_let_else.rs:66:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -109,14 +109,14 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         if true {}
 LL +         panic!();
 LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:70:5
+  --> $DIR/manual_let_else.rs:76:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -129,7 +129,7 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         match () {
 LL +             _ if panic!() => {},
 LL +             _ => panic!(),
@@ -138,13 +138,13 @@ LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:80:5
+  --> $DIR/manual_let_else.rs:86:5
    |
 LL |     let v = if let Some(v_some) = g() { v_some } else { if panic!() {} };
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v_some) = g() else { if panic!() {} };`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v) = g() else { if panic!() {} };`
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:83:5
+  --> $DIR/manual_let_else.rs:89:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -157,7 +157,7 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         match panic!() {
 LL +             _ => {},
 LL +         }
@@ -165,7 +165,7 @@ LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:92:5
+  --> $DIR/manual_let_else.rs:98:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -178,7 +178,7 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else { if true {
+LL ~     let Some(v) = g() else { if true {
 LL +         return;
 LL +     } else {
 LL +         panic!("diverge");
@@ -186,7 +186,7 @@ LL +     } };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:101:5
+  --> $DIR/manual_let_else.rs:107:5
    |
 LL | /     let v = if let Some(v_some) = g() {
 LL | |         v_some
@@ -199,7 +199,7 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g() else {
+LL ~     let Some(v) = g() else {
 LL +         match (g(), g()) {
 LL +             (Some(_), None) => return,
 LL +             (None, Some(_)) => {
@@ -215,7 +215,7 @@ LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:118:5
+  --> $DIR/manual_let_else.rs:124:5
    |
 LL | /     let (v, w) = if let Some(v_some) = g().map(|v| (v, 42)) {
 LL | |         v_some
@@ -226,13 +226,13 @@ LL | |     };
    |
 help: consider writing
    |
-LL ~     let Some(v_some) = g().map(|v| (v, 42)) else {
+LL ~     let Some((v, w)) = g().map(|v| (v, 42)) else {
 LL +         return;
 LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:125:5
+  --> $DIR/manual_let_else.rs:131:5
    |
 LL | /     let v = if let (Some(v_some), w_some) = (g(), 0) {
 LL | |         (w_some, v_some)
@@ -249,10 +249,10 @@ LL +     };
    |
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:134:13
+  --> $DIR/manual_let_else.rs:140:13
    |
 LL |             let $n = if let Some(v) = $e { v } else { return };
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some(v) = g() else { return };`
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Some($n) = g() else { return };`
 ...
 LL |     create_binding_if_some!(w, g());
    |     ------------------------------- in this macro invocation
@@ -260,13 +260,25 @@ LL |     create_binding_if_some!(w, g());
    = note: this error originates in the macro `create_binding_if_some` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: this could be rewritten as `let...else`
-  --> $DIR/manual_let_else.rs:247:5
+  --> $DIR/manual_let_else.rs:150:5
+   |
+LL |     let v = if let Variant::A(a, 0) = e() { a } else { return };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Variant::A(a, 0) = e() else { return };`
+
+error: this could be rewritten as `let...else`
+  --> $DIR/manual_let_else.rs:152:5
+   |
+LL |     let v = if let Variant::B(b) = e() { b } else { return };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider writing: `let Variant::B(v) = e() else { return };`
+
+error: this could be rewritten as `let...else`
+  --> $DIR/manual_let_else.rs:262:5
    |
 LL | /     let _ = match ff {
 LL | |         Some(value) => value,
 LL | |         _ => macro_call!(),
 LL | |     };
-   | |______^ help: consider writing: `let Some(value) = ff else { macro_call!() };`
+   | |______^ help: consider writing: `let Some(_) = ff else { macro_call!() };`
 
-error: aborting due to 18 previous errors
+error: aborting due to 20 previous errors
 

tests/ui/manual_let_else_match.stderr

@@ -5,7 +5,7 @@ LL | /     let v = match g() {
 LL | |         Some(v_some) => v_some,
 LL | |         None => return,
 LL | |     };
-   | |______^ help: consider writing: `let Some(v_some) = g() else { return };`
+   | |______^ help: consider writing: `let Some(v) = g() else { return };`
    |
    = note: `-D clippy::manual-let-else` implied by `-D warnings`
 
@@ -16,7 +16,7 @@ LL | /     let v = match g() {
 LL | |         Some(v_some) => v_some,
 LL | |         _ => return,
 LL | |     };
-   | |______^ help: consider writing: `let Some(v_some) = g() else { return };`
+   | |______^ help: consider writing: `let Some(v) = g() else { return };`
 
 error: this could be rewritten as `let...else`
   --> $DIR/manual_let_else_match.rs:44:9