From dff9164ac5a0118e78285869c16f35447b720354 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Thu, 2 May 2024 23:32:53 +0200
Subject: [PATCH 01/56] consider `copy_deref` a possible borrower

---
 clippy_utils/src/mir/possible_borrower.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_utils/src/mir/possible_borrower.rs b/clippy_utils/src/mir/possible_borrower.rs
index 06229ac938f9..b3210fa155c7 100644
--- a/clippy_utils/src/mir/possible_borrower.rs
+++ b/clippy_utils/src/mir/possible_borrower.rs
@@ -69,7 +69,7 @@ impl<'a, 'b, 'tcx> mir::visit::Visitor<'tcx> for PossibleBorrowerVisitor<'a, 'b,
     fn visit_assign(&mut self, place: &mir::Place<'tcx>, rvalue: &mir::Rvalue<'_>, _location: mir::Location) {
         let lhs = place.local;
         match rvalue {
-            mir::Rvalue::Ref(_, _, borrowed) => {
+            mir::Rvalue::Ref(_, _, borrowed) | mir::Rvalue::CopyForDeref(borrowed) => {
                 self.possible_borrower.add(borrowed.local, lhs);
             },
             other => {

From 20d1bb1867e6b5b5c79d1af7cb56b91e290d0283 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Thu, 2 May 2024 23:38:31 +0200
Subject: [PATCH 02/56] [`assigning_clones`]: bail out when the source borrows
 from target

---
 clippy_lints/src/assigning_clones.rs | 65 +++++++++++++++++++++++++++-
 tests/ui/assigning_clones.fixed      | 29 +++++++++++++
 tests/ui/assigning_clones.rs         | 29 +++++++++++++
 3 files changed, 122 insertions(+), 1 deletion(-)

diff --git a/clippy_lints/src/assigning_clones.rs b/clippy_lints/src/assigning_clones.rs
index 9202c46e8b6b..4819471746f0 100644
--- a/clippy_lints/src/assigning_clones.rs
+++ b/clippy_lints/src/assigning_clones.rs
@@ -1,16 +1,18 @@
 use clippy_config::msrvs::{self, Msrv};
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::macros::HirNode;
+use clippy_utils::mir::{enclosing_mir, PossibleBorrowerMap};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{is_trait_method, local_is_initialized, path_to_local};
 use rustc_errors::Applicability;
 use rustc_hir::{self as hir, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir;
 use rustc_middle::ty::{self, Instance, Mutability};
 use rustc_session::impl_lint_pass;
 use rustc_span::def_id::DefId;
 use rustc_span::symbol::sym;
-use rustc_span::{ExpnKind, SyntaxContext};
+use rustc_span::{ExpnKind, Span, SyntaxContext};
 
 declare_clippy_lint! {
     /// ### What it does
@@ -144,6 +146,7 @@ fn extract_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option<
     };
 
     Some(CallCandidate {
+        span: expr.span,
         target,
         kind,
         method_def_id: resolved_method.def_id(),
@@ -215,6 +218,10 @@ fn is_ok_to_suggest<'tcx>(cx: &LateContext<'tcx>, lhs: &Expr<'tcx>, call: &CallC
         return false;
     };
 
+    if clone_source_borrows_from_dest(cx, lhs, call.span) {
+        return false;
+    }
+
     // Now take a look if the impl block defines an implementation for the method that we're interested
     // in. If not, then we're using a default implementation, which is not interesting, so we will
     // not suggest the lint.
@@ -222,6 +229,61 @@ fn is_ok_to_suggest<'tcx>(cx: &LateContext<'tcx>, lhs: &Expr<'tcx>, call: &CallC
     implemented_fns.contains_key(&provided_fn.def_id)
 }
 
+/// Checks if the data being cloned borrows from the place that is being assigned to:
+///
+/// ```
+/// let mut s = String::new();
+/// let s2 = &s;
+/// s = s2.to_owned();
+/// ```
+///
+/// This cannot be written `s2.clone_into(&mut s)` because it has conflicting borrows.
+fn clone_source_borrows_from_dest(cx: &LateContext<'_>, lhs: &Expr<'_>, call_span: Span) -> bool {
+    let Some(mir) = enclosing_mir(cx.tcx, lhs.hir_id) else {
+        return false;
+    };
+    let PossibleBorrowerMap { map: borrow_map, .. } = PossibleBorrowerMap::new(cx, mir);
+
+    // The operation `dest = src.to_owned()` in MIR is split up across 3 blocks.
+    // For the doc example above that would be roughly:
+    //
+    // bb0:
+    //  s2 = &s
+    //  s_temp = ToOwned::to_owned(move s2) -> bb1
+    //
+    // bb1:
+    //  drop(s) -> bb2  // drop the old string
+    //
+    // bb2:
+    //  s = s_temp
+    for bb in mir.basic_blocks.iter() {
+        let terminator = bb.terminator();
+
+        // Look for the to_owned/clone call.
+        if terminator.source_info.span == call_span
+            && let mir::TerminatorKind::Call {
+                args,
+                target: Some(drop_bb),
+                ..
+            } = &terminator.kind
+            && let [source] = &**args
+            && let mir::Operand::Move(source) = &source.node
+            // Block 2 only has the `drop()` terminator from to the assignment
+            && let drop_bb = &mir.basic_blocks[*drop_bb]
+            && let mir::TerminatorKind::Drop { target: assign_bb, .. } = drop_bb.terminator().kind
+            // Block 3 has the final assignment to the original local
+            && let assign_bb = &mir.basic_blocks[assign_bb]
+            && let [assignment, ..] = &*assign_bb.statements
+            && let mir::StatementKind::Assign(box (borrowed, _)) = &assignment.kind
+            && let Some(borrowers) = borrow_map.get(&borrowed.local)
+            && borrowers.contains(source.local)
+        {
+            return true;
+        }
+    }
+    false
+}
+
 fn suggest<'tcx>(
     cx: &LateContext<'tcx>,
     ctxt: SyntaxContext,
@@ -255,6 +317,7 @@ enum TargetTrait {
 
 #[derive(Debug)]
 struct CallCandidate<'tcx> {
+    span: Span,
     target: TargetTrait,
     kind: CallKind<'tcx>,
     // DefId of the called method from an impl block that implements the target trait
diff --git a/tests/ui/assigning_clones.fixed b/tests/ui/assigning_clones.fixed
index 70ab43b49b3a..64a1f02eb051 100644
--- a/tests/ui/assigning_clones.fixed
+++ b/tests/ui/assigning_clones.fixed
@@ -272,3 +272,32 @@ impl<'a> Add for &'a mut HasCloneFrom {
         self
     }
 }
+
+mod borrowck_conflicts {
+    //! Cases where clone_into and friends cannot be used because the src/dest have conflicting
+    //! borrows.
+    use std::path::PathBuf;
+
+    fn issue12444(mut name: String) {
+        let parts = name.split(", ").collect::<Vec<_>>();
+        let first = *parts.first().unwrap();
+        name = first.to_owned();
+    }
+
+    fn issue12444_simple() {
+        let mut s = String::new();
+        let s2 = &s;
+        s = s2.to_owned();
+    }
+
+    fn issue12460(mut name: String) {
+        if let Some(stripped_name) = name.strip_prefix("baz-") {
+            name = stripped_name.to_owned();
+        }
+    }
+
+    fn issue12749() {
+        let mut path = PathBuf::from("/a/b/c");
+        path = path.components().as_path().to_owned();
+    }
+}
diff --git a/tests/ui/assigning_clones.rs b/tests/ui/assigning_clones.rs
index 9699fed100c8..b92452c35772 100644
--- a/tests/ui/assigning_clones.rs
+++ b/tests/ui/assigning_clones.rs
@@ -272,3 +272,32 @@ impl<'a> Add for &'a mut HasCloneFrom {
         self
     }
 }
+
+mod borrowck_conflicts {
+    //! Cases where clone_into and friends cannot be used because the src/dest have conflicting
+    //! borrows.
+    use std::path::PathBuf;
+
+    fn issue12444(mut name: String) {
+        let parts = name.split(", ").collect::<Vec<_>>();
+        let first = *parts.first().unwrap();
+        name = first.to_owned();
+    }
+
+    fn issue12444_simple() {
+        let mut s = String::new();
+        let s2 = &s;
+        s = s2.to_owned();
+    }
+
+    fn issue12460(mut name: String) {
+        if let Some(stripped_name) = name.strip_prefix("baz-") {
+            name = stripped_name.to_owned();
+        }
+    }
+
+    fn issue12749() {
+        let mut path = PathBuf::from("/a/b/c");
+        path = path.components().as_path().to_owned();
+    }
+}

From 60508f546a07fa51169736766b7e16676724c496 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Fri, 3 May 2024 01:45:49 +0200
Subject: [PATCH 03/56] deal with non-`Drop` types and add a test case for
 projections

---
 clippy_lints/src/assigning_clones.rs | 39 ++++++++++++++++++----------
 tests/ui/assigning_clones.fixed      | 27 +++++++++++++++++++
 tests/ui/assigning_clones.rs         | 27 +++++++++++++++++++
 3 files changed, 80 insertions(+), 13 deletions(-)

diff --git a/clippy_lints/src/assigning_clones.rs b/clippy_lints/src/assigning_clones.rs
index 4819471746f0..920d1bae0b17 100644
--- a/clippy_lints/src/assigning_clones.rs
+++ b/clippy_lints/src/assigning_clones.rs
@@ -239,12 +239,23 @@ fn is_ok_to_suggest<'tcx>(cx: &LateContext<'tcx>, lhs: &Expr<'tcx>, call: &CallC
 ///
 /// This cannot be written `s2.clone_into(&mut s)` because it has conflicting borrows.
 fn clone_source_borrows_from_dest(cx: &LateContext<'_>, lhs: &Expr<'_>, call_span: Span) -> bool {
+    /// If this basic block only exists to drop a local as part of an assignment, returns its
+    /// successor. Otherwise returns the basic block that was passed in.
+    fn skip_drop_block(mir: &mir::Body<'_>, bb: mir::BasicBlock) -> mir::BasicBlock {
+        if let mir::TerminatorKind::Drop { target, .. } = mir.basic_blocks[bb].terminator().kind {
+            target
+        } else {
+            bb
+        }
+    }
+
     let Some(mir) = enclosing_mir(cx.tcx, lhs.hir_id) else {
         return false;
     };
     let PossibleBorrowerMap { map: borrow_map, .. } = PossibleBorrowerMap::new(cx, mir);
 
-    // The operation `dest = src.to_owned()` in MIR is split up across 3 blocks.
+    // The operation `dest = src.to_owned()` in MIR is split up across 3 blocks *if* the type has `Drop`
+    // code. For types that don't, the second basic block is simply skipped.
     // For the doc example above that would be roughly:
     //
     // bb0:
@@ -260,26 +271,28 @@ fn clone_source_borrows_from_dest(cx: &LateContext<'_>, lhs: &Expr<'_>, call_spa
         let terminator = bb.terminator();
 
         // Look for the to_owned/clone call.
-        if terminator.source_info.span == call_span
-            && let mir::TerminatorKind::Call {
-                args,
-                target: Some(drop_bb),
-                ..
-            } = &terminator.kind
+        if terminator.source_info.span != call_span {
+            continue;
+        }
+
+        if let mir::TerminatorKind::Call { ref args, target: Some(assign_bb), .. } = terminator.kind
             && let [source] = &**args
             && let mir::Operand::Move(source) = &source.node
-            // Block 2 only has the `drop()` terminator from to the assignment
-            && let drop_bb = &mir.basic_blocks[*drop_bb]
-            && let mir::TerminatorKind::Drop { target: assign_bb, .. } = drop_bb.terminator().kind
-            // Block 3 has the final assignment to the original local
-            && let assign_bb = &mir.basic_blocks[assign_bb]
-            && let [assignment, ..] = &*assign_bb.statements
+            && let assign_bb = skip_drop_block(mir, assign_bb)
+            // Skip any storage statements as they are just noise
+            && let Some(assignment) = mir.basic_blocks[assign_bb].statements
+                .iter()
+                .find(|stmt| {
+                    !matches!(stmt.kind, mir::StatementKind::StorageDead(_) | mir::StatementKind::StorageLive(_))
+                })
             && let mir::StatementKind::Assign(box (borrowed, _)) = &assignment.kind
             && let Some(borrowers) = borrow_map.get(&borrowed.local)
             && borrowers.contains(source.local)
         {
             return true;
         }
+
+        return false;
     }
     false
 }
diff --git a/tests/ui/assigning_clones.fixed b/tests/ui/assigning_clones.fixed
index 64a1f02eb051..60f6a385fc50 100644
--- a/tests/ui/assigning_clones.fixed
+++ b/tests/ui/assigning_clones.fixed
@@ -290,6 +290,33 @@ mod borrowck_conflicts {
         s = s2.to_owned();
     }
 
+    fn issue12444_nodrop_projections() {
+        struct NoDrop;
+
+        impl Clone for NoDrop {
+            fn clone(&self) -> Self {
+                todo!()
+            }
+            fn clone_from(&mut self, other: &Self) {
+                todo!()
+            }
+        }
+
+        let mut s = NoDrop;
+        let s2 = &s;
+        s = s2.clone();
+
+        let mut s = (NoDrop, NoDrop);
+        let s2 = &s.0;
+        s.0 = s2.clone();
+
+        // This *could* emit a warning, but PossibleBorrowerMap only works with locals so it
+        // considers `s` fully borrowed
+        let mut s = (NoDrop, NoDrop);
+        let s2 = &s.1;
+        s.0 = s2.clone();
+    }
+
     fn issue12460(mut name: String) {
         if let Some(stripped_name) = name.strip_prefix("baz-") {
             name = stripped_name.to_owned();
diff --git a/tests/ui/assigning_clones.rs b/tests/ui/assigning_clones.rs
index b92452c35772..6eb85be511a8 100644
--- a/tests/ui/assigning_clones.rs
+++ b/tests/ui/assigning_clones.rs
@@ -290,6 +290,33 @@ mod borrowck_conflicts {
         s = s2.to_owned();
     }
 
+    fn issue12444_nodrop_projections() {
+        struct NoDrop;
+
+        impl Clone for NoDrop {
+            fn clone(&self) -> Self {
+                todo!()
+            }
+            fn clone_from(&mut self, other: &Self) {
+                todo!()
+            }
+        }
+
+        let mut s = NoDrop;
+        let s2 = &s;
+        s = s2.clone();
+
+        let mut s = (NoDrop, NoDrop);
+        let s2 = &s.0;
+        s.0 = s2.clone();
+
+        // This *could* emit a warning, but PossibleBorrowerMap only works with locals so it
+        // considers `s` fully borrowed
+        let mut s = (NoDrop, NoDrop);
+        let s2 = &s.1;
+        s.0 = s2.clone();
+    }
+
     fn issue12460(mut name: String) {
         if let Some(stripped_name) = name.strip_prefix("baz-") {
             name = stripped_name.to_owned();

From 7f66e567b2de4307ae49c01d832c93901e647a07 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 29 May 2024 09:08:22 +0000
Subject: [PATCH 04/56] Don't require `visit_body` to take a lifetime that must
 outlive the function call

---
 clippy_lints/src/default_numeric_fallback.rs          | 2 +-
 clippy_lints/src/dereference.rs                       | 2 +-
 clippy_lints/src/implicit_hasher.rs                   | 2 +-
 clippy_lints/src/macro_metavars_in_unsafe.rs          | 2 +-
 clippy_lints/src/needless_borrows_for_generic_args.rs | 2 +-
 clippy_lints/src/only_used_in_recursion.rs            | 4 ++--
 clippy_lints/src/operators/mod.rs                     | 4 ++--
 clippy_lints/src/ptr.rs                               | 6 +++---
 clippy_lints/src/question_mark.rs                     | 4 ++--
 9 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/clippy_lints/src/default_numeric_fallback.rs b/clippy_lints/src/default_numeric_fallback.rs
index 1d6c4ce72e18..4d8c066fea54 100644
--- a/clippy_lints/src/default_numeric_fallback.rs
+++ b/clippy_lints/src/default_numeric_fallback.rs
@@ -49,7 +49,7 @@ declare_clippy_lint! {
 declare_lint_pass!(DefaultNumericFallback => [DEFAULT_NUMERIC_FALLBACK]);
 
 impl<'tcx> LateLintPass<'tcx> for DefaultNumericFallback {
-    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &Body<'tcx>) {
         let hir = cx.tcx.hir();
         let is_parent_const = matches!(
             hir.body_const_context(hir.body_owner_def_id(body.id())),
diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs
index c6aef9ac2d60..297082354ff1 100644
--- a/clippy_lints/src/dereference.rs
+++ b/clippy_lints/src/dereference.rs
@@ -641,7 +641,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
         }
     }
 
-    fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+    fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &Body<'_>) {
         if Some(body.id()) == self.current_body {
             for pat in self.ref_locals.drain(..).filter_map(|(_, x)| x) {
                 let replacements = pat.replacements;
diff --git a/clippy_lints/src/implicit_hasher.rs b/clippy_lints/src/implicit_hasher.rs
index a46aae36d5c5..ca830af3b2f3 100644
--- a/clippy_lints/src/implicit_hasher.rs
+++ b/clippy_lints/src/implicit_hasher.rs
@@ -328,7 +328,7 @@ impl<'a, 'b, 'tcx> ImplicitHasherConstructorVisitor<'a, 'b, 'tcx> {
 impl<'a, 'b, 'tcx> Visitor<'tcx> for ImplicitHasherConstructorVisitor<'a, 'b, 'tcx> {
     type NestedFilter = nested_filter::OnlyBodies;
 
-    fn visit_body(&mut self, body: &'tcx Body<'_>) {
+    fn visit_body(&mut self, body: &Body<'tcx>) {
         let old_maybe_typeck_results = self.maybe_typeck_results.replace(self.cx.tcx.typeck_body(body.id()));
         walk_body(self, body);
         self.maybe_typeck_results = old_maybe_typeck_results;
diff --git a/clippy_lints/src/macro_metavars_in_unsafe.rs b/clippy_lints/src/macro_metavars_in_unsafe.rs
index aea3d26e1878..d1ae243877d7 100644
--- a/clippy_lints/src/macro_metavars_in_unsafe.rs
+++ b/clippy_lints/src/macro_metavars_in_unsafe.rs
@@ -186,7 +186,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BodyVisitor<'a, 'tcx> {
 }
 
 impl<'tcx> LateLintPass<'tcx> for ExprMetavarsInUnsafe {
-    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx rustc_hir::Body<'tcx>) {
+    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &rustc_hir::Body<'tcx>) {
         if is_lint_allowed(cx, MACRO_METAVARS_IN_UNSAFE, body.value.hir_id) {
             return;
         }
diff --git a/clippy_lints/src/needless_borrows_for_generic_args.rs b/clippy_lints/src/needless_borrows_for_generic_args.rs
index daf166bad90d..5b5e1c234245 100644
--- a/clippy_lints/src/needless_borrows_for_generic_args.rs
+++ b/clippy_lints/src/needless_borrows_for_generic_args.rs
@@ -129,7 +129,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowsForGenericArgs<'tcx> {
         }
     }
 
-    fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+    fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &Body<'_>) {
         if self.possible_borrowers.last().map_or(false, |&(local_def_id, _)| {
             local_def_id == cx.tcx.hir().body_owner_def_id(body.id())
         }) {
diff --git a/clippy_lints/src/only_used_in_recursion.rs b/clippy_lints/src/only_used_in_recursion.rs
index b3ff5ecae862..8b8aabe7accc 100644
--- a/clippy_lints/src/only_used_in_recursion.rs
+++ b/clippy_lints/src/only_used_in_recursion.rs
@@ -221,7 +221,7 @@ pub struct OnlyUsedInRecursion {
 }
 
 impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
-    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'tcx>) {
+    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &Body<'tcx>) {
         if body.value.span.from_expansion() {
             return;
         }
@@ -350,7 +350,7 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
         }
     }
 
-    fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'tcx>) {
+    fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &Body<'tcx>) {
         if self.entered_body == Some(body.value.hir_id) {
             self.entered_body = None;
             self.params.flag_for_linting();
diff --git a/clippy_lints/src/operators/mod.rs b/clippy_lints/src/operators/mod.rs
index e002429e3a47..9e77d0e09c48 100644
--- a/clippy_lints/src/operators/mod.rs
+++ b/clippy_lints/src/operators/mod.rs
@@ -868,11 +868,11 @@ impl<'tcx> LateLintPass<'tcx> for Operators {
         self.arithmetic_context.expr_post(e.hir_id);
     }
 
-    fn check_body(&mut self, cx: &LateContext<'tcx>, b: &'tcx Body<'_>) {
+    fn check_body(&mut self, cx: &LateContext<'tcx>, b: &Body<'_>) {
         self.arithmetic_context.enter_body(cx, b);
     }
 
-    fn check_body_post(&mut self, cx: &LateContext<'tcx>, b: &'tcx Body<'_>) {
+    fn check_body_post(&mut self, cx: &LateContext<'tcx>, b: &Body<'_>) {
         self.arithmetic_context.body_post(cx, b);
     }
 }
diff --git a/clippy_lints/src/ptr.rs b/clippy_lints/src/ptr.rs
index 38580dc58226..02c05e0aaf9c 100644
--- a/clippy_lints/src/ptr.rs
+++ b/clippy_lints/src/ptr.rs
@@ -188,7 +188,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
         }
     }
 
-    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) {
+    fn check_body(&mut self, cx: &LateContext<'tcx>, body: &Body<'tcx>) {
         let hir = cx.tcx.hir();
         let mut parents = hir.parent_iter(body.value.hir_id);
         let (item_id, sig, is_trait_item) = match parents.next() {
@@ -525,7 +525,7 @@ fn check_fn_args<'cx, 'tcx: 'cx>(
         })
 }
 
-fn check_mut_from_ref<'tcx>(cx: &LateContext<'tcx>, sig: &FnSig<'_>, body: Option<&'tcx Body<'_>>) {
+fn check_mut_from_ref<'tcx>(cx: &LateContext<'tcx>, sig: &FnSig<'_>, body: Option<&Body<'tcx>>) {
     if let FnRetTy::Return(ty) = sig.decl.output
         && let Some((out, Mutability::Mut, _)) = get_ref_lm(ty)
     {
@@ -559,7 +559,7 @@ fn check_mut_from_ref<'tcx>(cx: &LateContext<'tcx>, sig: &FnSig<'_>, body: Optio
 }
 
 #[expect(clippy::too_many_lines)]
-fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &'tcx Body<'_>, args: &[PtrArg<'tcx>]) -> Vec<PtrArgResult> {
+fn check_ptr_arg_usage<'tcx>(cx: &LateContext<'tcx>, body: &Body<'tcx>, args: &[PtrArg<'tcx>]) -> Vec<PtrArgResult> {
     struct V<'cx, 'tcx> {
         cx: &'cx LateContext<'tcx>,
         /// Map from a local id to which argument it came from (index into `Self::args` and
diff --git a/clippy_lints/src/question_mark.rs b/clippy_lints/src/question_mark.rs
index 1f1ce147ca24..7cf98ad9e09a 100644
--- a/clippy_lints/src/question_mark.rs
+++ b/clippy_lints/src/question_mark.rs
@@ -370,11 +370,11 @@ impl<'tcx> LateLintPass<'tcx> for QuestionMark {
         }
     }
 
-    fn check_body(&mut self, _: &LateContext<'tcx>, _: &'tcx Body<'tcx>) {
+    fn check_body(&mut self, _: &LateContext<'tcx>, _: &Body<'tcx>) {
         self.try_block_depth_stack.push(0);
     }
 
-    fn check_body_post(&mut self, _: &LateContext<'tcx>, _: &'tcx Body<'tcx>) {
+    fn check_body_post(&mut self, _: &LateContext<'tcx>, _: &Body<'tcx>) {
         self.try_block_depth_stack.pop();
     }
 

From f44a6a7cb59ddff2964e26c9eb0ad50a6c555c99 Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Wed, 29 May 2024 10:03:40 +0000
Subject: [PATCH 05/56] Make `body_owned_by` return the body directly.

Almost all callers want this anyway, and now we can use it to also return fed bodies
---
 clippy_lints/src/methods/option_map_unwrap_or.rs            | 4 ++--
 clippy_lints/src/single_call_fn.rs                          | 1 -
 clippy_lints/src/transmute/missing_transmute_annotations.rs | 4 ++--
 clippy_lints/src/unconditional_recursion.rs                 | 2 +-
 clippy_lints/src/utils/author.rs                            | 4 ++--
 5 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/clippy_lints/src/methods/option_map_unwrap_or.rs b/clippy_lints/src/methods/option_map_unwrap_or.rs
index efec9dd716dc..ca331f3e7568 100644
--- a/clippy_lints/src/methods/option_map_unwrap_or.rs
+++ b/clippy_lints/src/methods/option_map_unwrap_or.rs
@@ -59,8 +59,8 @@ pub(super) fn check<'tcx>(
             };
 
             let map = cx.tcx.hir();
-            let body = map.body(map.body_owned_by(map.enclosing_body_owner(expr.hir_id)));
-            reference_visitor.visit_body(body);
+            let body = map.body_owned_by(map.enclosing_body_owner(expr.hir_id));
+            reference_visitor.visit_body(&body);
 
             if reference_visitor.found_reference {
                 return;
diff --git a/clippy_lints/src/single_call_fn.rs b/clippy_lints/src/single_call_fn.rs
index 2ce7e714c642..f8e09d517f57 100644
--- a/clippy_lints/src/single_call_fn.rs
+++ b/clippy_lints/src/single_call_fn.rs
@@ -79,7 +79,6 @@ impl SingleCallFn {
                 .tcx
                 .hir()
                 .maybe_body_owned_by(fn_def_id)
-                .map(|body| cx.tcx.hir().body(body))
                 .map_or(true, |body| is_in_test_function(cx.tcx, body.value.hir_id))
             || match cx.tcx.hir_node(fn_hir_id) {
                 Node::Item(item) => is_from_proc_macro(cx, item),
diff --git a/clippy_lints/src/transmute/missing_transmute_annotations.rs b/clippy_lints/src/transmute/missing_transmute_annotations.rs
index cc6ff1cf3b42..f98ea59a15d8 100644
--- a/clippy_lints/src/transmute/missing_transmute_annotations.rs
+++ b/clippy_lints/src/transmute/missing_transmute_annotations.rs
@@ -30,8 +30,8 @@ fn get_parent_local_binding_ty<'tcx>(cx: &LateContext<'tcx>, expr_hir_id: HirId)
 
 fn is_function_block(cx: &LateContext<'_>, expr_hir_id: HirId) -> bool {
     let def_id = cx.tcx.hir().enclosing_body_owner(expr_hir_id);
-    if let Some(body_id) = cx.tcx.hir().maybe_body_owned_by(def_id) {
-        let body = cx.tcx.hir().body(body_id);
+    if let Some(body) = cx.tcx.hir().maybe_body_owned_by(def_id) {
+        let body = cx.tcx.hir().body(body.id());
         return body.value.peel_blocks().hir_id == expr_hir_id;
     }
     false
diff --git a/clippy_lints/src/unconditional_recursion.rs b/clippy_lints/src/unconditional_recursion.rs
index 0c4e2c91aec5..5e41b3f4914f 100644
--- a/clippy_lints/src/unconditional_recursion.rs
+++ b/clippy_lints/src/unconditional_recursion.rs
@@ -336,7 +336,7 @@ impl UnconditionalRecursion {
                         // We need to use typeck here to infer the actual function being called.
                         && let body_def_id = cx.tcx.hir().enclosing_body_owner(call_expr.hir_id)
                         && let Some(body_owner) = cx.tcx.hir().maybe_body_owned_by(body_def_id)
-                        && let typeck = cx.tcx.typeck_body(body_owner)
+                        && let typeck = cx.tcx.typeck_body(body_owner.id())
                         && let Some(call_def_id) = typeck.type_dependent_def_id(call_expr.hir_id)
                     {
                         self.default_impl_for_type.insert(self_def_id, call_def_id);
diff --git a/clippy_lints/src/utils/author.rs b/clippy_lints/src/utils/author.rs
index 4448c9ae3df7..18a31abddd0a 100644
--- a/clippy_lints/src/utils/author.rs
+++ b/clippy_lints/src/utils/author.rs
@@ -137,9 +137,9 @@ impl<'tcx> LateLintPass<'tcx> for Author {
 
 fn check_item(cx: &LateContext<'_>, hir_id: HirId) {
     let hir = cx.tcx.hir();
-    if let Some(body_id) = hir.maybe_body_owned_by(hir_id.expect_owner().def_id) {
+    if let Some(body) = hir.maybe_body_owned_by(hir_id.expect_owner().def_id) {
         check_node(cx, hir_id, |v| {
-            v.expr(&v.bind("expr", hir.body(body_id).value));
+            v.expr(&v.bind("expr", body.value));
         });
     }
 }

From d38920f67752c270dcdbf7444f668c019864f12f Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Wed, 29 May 2024 21:30:21 +0300
Subject: [PATCH 06/56] ast: Revert a breaking attribute visiting order change

---
 tests/ui/tabs_in_doc_comments.stderr | 48 ++++++++++++++--------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/tests/ui/tabs_in_doc_comments.stderr b/tests/ui/tabs_in_doc_comments.stderr
index aef6c3914526..23d5dcd3a8da 100644
--- a/tests/ui/tabs_in_doc_comments.stderr
+++ b/tests/ui/tabs_in_doc_comments.stderr
@@ -1,53 +1,53 @@
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:6:5
+  --> tests/ui/tabs_in_doc_comments.rs:10:9
    |
-LL | ///     - first        one
-   |     ^^^^ help: consider using four spaces per tab
+LL |     ///     - First String:
+   |         ^^^^ help: consider using four spaces per tab
    |
    = note: `-D clippy::tabs-in-doc-comments` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::tabs_in_doc_comments)]`
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:6:13
+  --> tests/ui/tabs_in_doc_comments.rs:11:9
    |
-LL | ///     - first        one
-   |                ^^^^^^^^ help: consider using four spaces per tab
+LL |     ///         - needs to be inside here
+   |         ^^^^^^^^ help: consider using four spaces per tab
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:7:5
+  --> tests/ui/tabs_in_doc_comments.rs:14:9
    |
-LL | ///     - second    one
-   |     ^^^^ help: consider using four spaces per tab
+LL |     ///     - Second String:
+   |         ^^^^ help: consider using four spaces per tab
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:7:14
+  --> tests/ui/tabs_in_doc_comments.rs:15:9
    |
-LL | ///     - second    one
-   |                 ^^^^ help: consider using four spaces per tab
+LL |     ///         - needs to be inside here
+   |         ^^^^^^^^ help: consider using four spaces per tab
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:10:9
+  --> tests/ui/tabs_in_doc_comments.rs:6:5
    |
-LL |     ///     - First String:
-   |         ^^^^ help: consider using four spaces per tab
+LL | ///     - first        one
+   |     ^^^^ help: consider using four spaces per tab
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:11:9
+  --> tests/ui/tabs_in_doc_comments.rs:6:13
    |
-LL |     ///         - needs to be inside here
-   |         ^^^^^^^^ help: consider using four spaces per tab
+LL | ///     - first        one
+   |                ^^^^^^^^ help: consider using four spaces per tab
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:14:9
+  --> tests/ui/tabs_in_doc_comments.rs:7:5
    |
-LL |     ///     - Second String:
-   |         ^^^^ help: consider using four spaces per tab
+LL | ///     - second    one
+   |     ^^^^ help: consider using four spaces per tab
 
 error: using tabs in doc comments is not recommended
-  --> tests/ui/tabs_in_doc_comments.rs:15:9
+  --> tests/ui/tabs_in_doc_comments.rs:7:14
    |
-LL |     ///         - needs to be inside here
-   |         ^^^^^^^^ help: consider using four spaces per tab
+LL | ///     - second    one
+   |                 ^^^^ help: consider using four spaces per tab
 
 error: aborting due to 8 previous errors
 

From f67f72695a2ac5e7a1d39383583a6abb1cf9f4ad Mon Sep 17 00:00:00 2001
From: Philipp Krones <hello@philkrones.com>
Date: Thu, 30 May 2024 10:49:05 +0200
Subject: [PATCH 07/56] Merge commit 'c9139bd546d9cd69df817faeab62c5f9b1a51337'
 into clippy-subtree-update

---
 book/src/configuration.md                     |   2 +-
 book/src/development/adding_lints.md          |   5 +
 clippy_dev/src/new_lint.rs                    |   7 +-
 clippy_lints/src/absolute_paths.rs            |   2 +-
 clippy_lints/src/allow_attributes.rs          |   7 +-
 clippy_lints/src/as_conversions.rs            |   2 +-
 clippy_lints/src/asm_syntax.rs                |  10 +-
 .../src/assertions_on_result_states.rs        |  20 +-
 clippy_lints/src/attrs/mod.rs                 |   6 +-
 clippy_lints/src/casts/mod.rs                 |   6 +-
 clippy_lints/src/create_dir.rs                |   6 +-
 clippy_lints/src/dbg_macro.rs                 |   2 +-
 clippy_lints/src/default_numeric_fallback.rs  |   5 +-
 .../src/default_union_representation.rs       |   2 +-
 clippy_lints/src/dereference.rs               |  14 +-
 clippy_lints/src/derive.rs                    |  31 +-
 clippy_lints/src/disallowed_script_idents.rs  |   4 +-
 clippy_lints/src/doc/markdown.rs              |  28 +-
 clippy_lints/src/doc/mod.rs                   |   2 +-
 clippy_lints/src/drop_forget_ref.rs           |   7 +-
 clippy_lints/src/else_if_without_else.rs      |   2 +-
 clippy_lints/src/empty_drop.rs                |   2 +-
 clippy_lints/src/empty_enum.rs                |  45 +-
 clippy_lints/src/empty_with_brackets.rs       |  24 +-
 clippy_lints/src/endian_bytes.rs              |  15 +-
 clippy_lints/src/error_impl_error.rs          |   2 +-
 clippy_lints/src/exhaustive_items.rs          |  16 +-
 clippy_lints/src/exit.rs                      |  12 +-
 clippy_lints/src/float_literal.rs             |   6 +-
 clippy_lints/src/format_push_string.rs        |   2 +-
 .../src/functions/misnamed_getters.rs         |   2 +-
 clippy_lints/src/functions/mod.rs             |  11 +-
 clippy_lints/src/if_then_some_else_none.rs    |   2 +-
 clippy_lints/src/implicit_return.rs           |  13 +-
 clippy_lints/src/indexing_slicing.rs          |   7 +-
 clippy_lints/src/inherent_impl.rs             |   2 +-
 clippy_lints/src/init_numbered_fields.rs      |   4 +-
 .../src/integer_division_remainder_used.rs    |   6 +-
 clippy_lints/src/iter_over_hash_type.rs       |   4 +-
 clippy_lints/src/large_include_file.rs        |   8 +-
 clippy_lints/src/let_underscore.rs            |   9 +-
 clippy_lints/src/literal_representation.rs    |   4 +-
 clippy_lints/src/loops/mod.rs                 |   6 +-
 clippy_lints/src/matches/mod.rs               |   6 +-
 .../matches/significant_drop_in_scrutinee.rs  | 418 ++++++++++--------
 .../iter_on_single_or_empty_collections.rs    |  47 +-
 clippy_lints/src/methods/mod.rs               |  21 +-
 .../src/methods/unnecessary_iter_cloned.rs    |  16 +-
 clippy_lints/src/methods/utils.rs             |  16 +-
 clippy_lints/src/min_ident_chars.rs           |   7 +-
 clippy_lints/src/misc_early/mod.rs            |   6 +-
 clippy_lints/src/missing_assert_message.rs    |   2 +-
 .../src/missing_asserts_for_indexing.rs       |   2 +-
 clippy_lints/src/missing_doc.rs               |   4 +-
 clippy_lints/src/missing_inline.rs            |  19 +-
 clippy_lints/src/missing_trait_methods.rs     |  10 +-
 .../src/mixed_read_write_in_expression.rs     |   9 +-
 clippy_lints/src/module_style.rs              |   6 +-
 .../src/multiple_unsafe_ops_per_block.rs      |   4 +-
 clippy_lints/src/mutex_atomic.rs              |   2 +-
 clippy_lints/src/needless_bool.rs             |  13 +-
 clippy_lints/src/non_expressive_names.rs      |   4 +
 clippy_lints/src/operators/mod.rs             |  12 +-
 clippy_lints/src/panic_in_result_fn.rs        |   4 +-
 clippy_lints/src/panic_unimplemented.rs       |  18 +-
 clippy_lints/src/partial_pub_fields.rs        |   9 +-
 clippy_lints/src/pattern_type_mismatch.rs     |   5 +-
 clippy_lints/src/pub_use.rs                   |   8 +-
 clippy_lints/src/question_mark_used.rs        |   2 +-
 clippy_lints/src/raw_strings.rs               |   6 +-
 clippy_lints/src/redundant_slicing.rs         |   2 +-
 .../src/redundant_type_annotations.rs         |   2 +-
 clippy_lints/src/ref_patterns.rs              |   4 +-
 clippy_lints/src/returns.rs                   |  34 +-
 clippy_lints/src/same_name_method.rs          |   2 +-
 clippy_lints/src/semicolon_block.rs           |   6 +-
 clippy_lints/src/shadow.rs                    |  26 +-
 clippy_lints/src/single_call_fn.rs            |  19 +-
 .../src/single_char_lifetime_names.rs         |   5 +-
 clippy_lints/src/std_instead_of_core.rs       |  12 +-
 clippy_lints/src/strings.rs                   |  19 +-
 .../src/suspicious_xor_used_as_pow.rs         |   4 +-
 clippy_lints/src/tests_outside_test_module.rs |   4 +-
 clippy_lints/src/types/mod.rs                 |   4 +-
 .../src/undocumented_unsafe_blocks.rs         |   9 +-
 clippy_lints/src/unicode.rs                   |   2 +-
 clippy_lints/src/unnecessary_self_imports.rs  |   2 +-
 clippy_lints/src/unwrap_in_result.rs          |   6 +-
 clippy_lints/src/visibility.rs                |   4 +-
 clippy_lints/src/write.rs                     |  13 +-
 clippy_utils/src/consts.rs                    |   6 +-
 clippy_utils/src/hir_utils.rs                 |   2 +-
 clippy_utils/src/lib.rs                       |  22 +
 clippy_utils/src/ty.rs                        |   6 +-
 rust-toolchain                                |   2 +-
 tests/ui-internal/disallow_span_lint.rs       |   8 +-
 tests/ui-internal/disallow_span_lint.stderr   |  14 +-
 tests/ui/derive_partial_eq_without_eq.fixed   |  17 +
 tests/ui/derive_partial_eq_without_eq.rs      |  17 +
 tests/ui/derive_partial_eq_without_eq.stderr  |  26 +-
 tests/ui/doc/doc-fixable.fixed                |   3 +
 tests/ui/doc/doc-fixable.rs                   |   3 +
 tests/ui/doc/doc-fixable.stderr               |   8 +-
 tests/ui/doc/issue_12795.fixed                |   9 +
 tests/ui/doc/issue_12795.rs                   |   9 +
 tests/ui/doc/issue_12795.stderr               |  48 ++
 tests/ui/iter_on_empty_collections.fixed      |  22 +
 tests/ui/iter_on_empty_collections.rs         |  22 +
 tests/ui/iter_on_empty_collections.stderr     |   8 +-
 tests/ui/let_and_return.fixed                 |  34 ++
 tests/ui/let_and_return.rs                    |  34 ++
 tests/ui/let_and_return.stderr                |  72 ++-
 tests/ui/many_single_char_names.rs            |   2 -
 tests/ui/many_single_char_names.stderr        |  10 +-
 tests/ui/needless_return.fixed                |   4 +
 tests/ui/needless_return.rs                   |   4 +
 tests/ui/needless_return.stderr               |  14 +-
 tests/ui/numbered_fields.fixed                |   5 +
 tests/ui/numbered_fields.rs                   |   5 +
 tests/ui/numbered_fields.stderr               |   8 +-
 tests/ui/significant_drop_in_scrutinee.rs     |  98 +++-
 tests/ui/significant_drop_in_scrutinee.stderr | 206 +++++----
 tests/ui/unnecessary_iter_cloned.fixed        |  29 ++
 tests/ui/unnecessary_iter_cloned.rs           |  29 ++
 tests/ui/unnecessary_iter_cloned.stderr       |  44 +-
 tests/ui/unnecessary_to_owned.stderr          |   2 +-
 tests/ui/unsafe_derive_deserialize.rs         |  11 +
 tests/ui/unsafe_derive_deserialize.stderr     |   8 +-
 128 files changed, 1422 insertions(+), 676 deletions(-)
 create mode 100644 tests/ui/doc/issue_12795.fixed
 create mode 100644 tests/ui/doc/issue_12795.rs
 create mode 100644 tests/ui/doc/issue_12795.stderr

diff --git a/book/src/configuration.md b/book/src/configuration.md
index 9eb067abd91e..ea549e4df4a5 100644
--- a/book/src/configuration.md
+++ b/book/src/configuration.md
@@ -133,7 +133,7 @@ Very rarely, you may wish to prevent Clippy from evaluating certain sections of
 `clippy` cfg is not set. You may need to provide a stub so that the code compiles:
 
 ```rust
-#[cfg(not(clippy)]
+#[cfg(not(clippy))]
 include!(concat!(env!("OUT_DIR"), "/my_big_function-generated.rs"));
 
 #[cfg(clippy)]
diff --git a/book/src/development/adding_lints.md b/book/src/development/adding_lints.md
index 415022612caa..48c00bcbf341 100644
--- a/book/src/development/adding_lints.md
+++ b/book/src/development/adding_lints.md
@@ -587,6 +587,11 @@ declare_clippy_lint! {
 }
 ```
 
+If the lint is in the `restriction` group because it lints things that are not
+necessarily “bad” but are more of a style choice, then replace the
+“Why is this bad?” section heading with “Why restrict this?”, to avoid writing
+“Why is this bad? It isn't, but ...”.
+
 Once your lint is merged, this documentation will show up in the [lint
 list][lint_list].
 
diff --git a/clippy_dev/src/new_lint.rs b/clippy_dev/src/new_lint.rs
index b6481dde4dde..2e56eb8ec15f 100644
--- a/clippy_dev/src/new_lint.rs
+++ b/clippy_dev/src/new_lint.rs
@@ -331,12 +331,17 @@ fn get_lint_file_contents(lint: &LintData<'_>, enable_msrv: bool) -> String {
 }
 
 fn get_lint_declaration(name_upper: &str, category: &str) -> String {
+    let justification_heading = if category == "restriction" {
+        "Why restrict this?"
+    } else {
+        "Why is this bad?"
+    };
     formatdoc!(
         r#"
             declare_clippy_lint! {{
                 /// ### What it does
                 ///
-                /// ### Why is this bad?
+                /// ### {justification_heading}
                 ///
                 /// ### Example
                 /// ```no_run
diff --git a/clippy_lints/src/absolute_paths.rs b/clippy_lints/src/absolute_paths.rs
index 8ba661afeeb6..461117cf965d 100644
--- a/clippy_lints/src/absolute_paths.rs
+++ b/clippy_lints/src/absolute_paths.rs
@@ -12,7 +12,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of items through absolute paths, like `std::env::current_dir`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Many codebases have their own style when it comes to importing, but one that is seldom used
     /// is using absolute paths *everywhere*. This is generally considered unidiomatic, and you
     /// should add a `use` statement.
diff --git a/clippy_lints/src/allow_attributes.rs b/clippy_lints/src/allow_attributes.rs
index 39fc49dee377..123d0e51eeee 100644
--- a/clippy_lints/src/allow_attributes.rs
+++ b/clippy_lints/src/allow_attributes.rs
@@ -19,10 +19,11 @@ declare_clippy_lint! {
     /// This lint only warns outer attributes (`#[allow]`), as inner attributes
     /// (`#![allow]`) are usually used to enable or disable lints on a global scale.
     ///
-    /// ### Why is this bad?
-    /// `#[expect]` attributes suppress the lint emission, but emit a warning, if
+    /// ### Why restrict this?
+    /// `#[allow]` attributes can linger after their reason for existence is gone.
+    /// `#[expect]` attributes suppress the lint emission, but emit a warning if
     /// the expectation is unfulfilled. This can be useful to be notified when the
-    /// lint is no longer triggered.
+    /// lint is no longer triggered, which may indicate the attribute can be removed.
     ///
     /// ### Example
     /// ```rust,ignore
diff --git a/clippy_lints/src/as_conversions.rs b/clippy_lints/src/as_conversions.rs
index e3daf75c3eb6..cfa25005a05e 100644
--- a/clippy_lints/src/as_conversions.rs
+++ b/clippy_lints/src/as_conversions.rs
@@ -17,7 +17,7 @@ declare_clippy_lint! {
     /// There is a good explanation the reason why this lint should work in this way and how it is useful
     /// [in this issue](https://github.com/rust-lang/rust-clippy/issues/5122).
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// `as` conversions will perform many kinds of
     /// conversions, including silently lossy conversions and dangerous coercions.
     /// There are cases when it makes sense to use `as`, so the lint is
diff --git a/clippy_lints/src/asm_syntax.rs b/clippy_lints/src/asm_syntax.rs
index 7c88bfc97ca4..0db1456d40bf 100644
--- a/clippy_lints/src/asm_syntax.rs
+++ b/clippy_lints/src/asm_syntax.rs
@@ -65,9 +65,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of Intel x86 assembly syntax.
     ///
-    /// ### Why is this bad?
-    /// The lint has been enabled to indicate a preference
-    /// for AT&T x86 assembly syntax.
+    /// ### Why restrict this?
+    /// To enforce consistent use of AT&T x86 assembly syntax.
     ///
     /// ### Example
     ///
@@ -114,9 +113,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of AT&T x86 assembly syntax.
     ///
-    /// ### Why is this bad?
-    /// The lint has been enabled to indicate a preference
-    /// for Intel x86 assembly syntax.
+    /// ### Why restrict this?
+    /// To enforce consistent use of Intel x86 assembly syntax.
     ///
     /// ### Example
     ///
diff --git a/clippy_lints/src/assertions_on_result_states.rs b/clippy_lints/src/assertions_on_result_states.rs
index aec22965b1b0..7217686dcca5 100644
--- a/clippy_lints/src/assertions_on_result_states.rs
+++ b/clippy_lints/src/assertions_on_result_states.rs
@@ -16,23 +16,33 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `assert!(r.is_ok())` or `assert!(r.is_err())` calls.
     ///
-    /// ### Why is this bad?
-    /// An assertion failure cannot output an useful message of the error.
+    /// ### Why restrict this?
+    /// This form of assertion does not show any of the information present in the `Result`
+    /// other than which variant it isn’t.
     ///
     /// ### Known problems
     /// The suggested replacement decreases the readability of code and log output.
     ///
     /// ### Example
-    /// ```rust,ignore
+    /// ```rust,no_run
     /// # let r = Ok::<_, ()>(());
     /// assert!(r.is_ok());
-    /// # let r = Err::<_, ()>(());
+    /// # let r = Err::<(), _>(());
     /// assert!(r.is_err());
     /// ```
+    ///
+    /// Use instead:
+    ///
+    /// ```rust,no_run
+    /// # let r = Ok::<_, ()>(());
+    /// r.unwrap();
+    /// # let r = Err::<(), _>(());
+    /// r.unwrap_err();
+    /// ```
     #[clippy::version = "1.64.0"]
     pub ASSERTIONS_ON_RESULT_STATES,
     restriction,
-    "`assert!(r.is_ok())`/`assert!(r.is_err())` gives worse error message than directly calling `r.unwrap()`/`r.unwrap_err()`"
+    "`assert!(r.is_ok())` or `assert!(r.is_err())` gives worse panic messages than directly calling `r.unwrap()` or `r.unwrap_err()`"
 }
 
 declare_lint_pass!(AssertionsOnResultStates => [ASSERTIONS_ON_RESULT_STATES]);
diff --git a/clippy_lints/src/attrs/mod.rs b/clippy_lints/src/attrs/mod.rs
index 39f406077995..a24bd5ed44be 100644
--- a/clippy_lints/src/attrs/mod.rs
+++ b/clippy_lints/src/attrs/mod.rs
@@ -309,9 +309,9 @@ declare_clippy_lint! {
     ///
     /// (This requires the `lint_reasons` feature)
     ///
-    /// ### Why is this bad?
-    /// Allowing a lint should always have a reason. This reason should be documented to
-    /// ensure that others understand the reasoning
+    /// ### Why restrict this?
+    /// Justifying each `allow` helps readers understand the reasoning,
+    /// and may allow removing `allow` attributes if their purpose is obsolete.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/casts/mod.rs b/clippy_lints/src/casts/mod.rs
index bd2c96f01f6f..e60c36ced75d 100644
--- a/clippy_lints/src/casts/mod.rs
+++ b/clippy_lints/src/casts/mod.rs
@@ -303,7 +303,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for casts of a function pointer to any integer type.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Casting a function pointer to an integer can have surprising results and can occur
     /// accidentally if parentheses are omitted from a function call. If you aren't doing anything
     /// low-level with function pointers then you can opt-out of casting functions to integers in
@@ -535,8 +535,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for the usage of `as _` conversion using inferred type.
     ///
-    /// ### Why is this bad?
-    /// The conversion might include lossy conversion and dangerous cast that might go
+    /// ### Why restrict this?
+    /// The conversion might include lossy conversion or a dangerous cast that might go
     /// undetected due to the type being inferred.
     ///
     /// The lint is allowed by default as using `_` is less wordy than always specifying the type.
diff --git a/clippy_lints/src/create_dir.rs b/clippy_lints/src/create_dir.rs
index 7a3d5a070912..27c00948a8f2 100644
--- a/clippy_lints/src/create_dir.rs
+++ b/clippy_lints/src/create_dir.rs
@@ -10,8 +10,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks usage of `std::fs::create_dir` and suggest using `std::fs::create_dir_all` instead.
     ///
-    /// ### Why is this bad?
-    /// Sometimes `std::fs::create_dir` is mistakenly chosen over `std::fs::create_dir_all`.
+    /// ### Why restrict this?
+    /// Sometimes `std::fs::create_dir` is mistakenly chosen over `std::fs::create_dir_all`,
+    /// resulting in failure when more than one directory needs to be created or when the directory already exists.
+    /// Crates which never need to specifically create a single directory may wish to prevent this mistake.
     ///
     /// ### Example
     /// ```rust,ignore
diff --git a/clippy_lints/src/dbg_macro.rs b/clippy_lints/src/dbg_macro.rs
index db5937266047..b0590b0a71cb 100644
--- a/clippy_lints/src/dbg_macro.rs
+++ b/clippy_lints/src/dbg_macro.rs
@@ -14,7 +14,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of the [`dbg!`](https://doc.rust-lang.org/std/macro.dbg.html) macro.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// The `dbg!` macro is intended as a debugging tool. It should not be present in released
     /// software or committed to a version control system.
     ///
diff --git a/clippy_lints/src/default_numeric_fallback.rs b/clippy_lints/src/default_numeric_fallback.rs
index 1d6c4ce72e18..fbc4ede37b1c 100644
--- a/clippy_lints/src/default_numeric_fallback.rs
+++ b/clippy_lints/src/default_numeric_fallback.rs
@@ -22,9 +22,8 @@ declare_clippy_lint! {
     ///
     /// See [RFC0212](https://github.com/rust-lang/rfcs/blob/master/text/0212-restore-int-fallback.md) for more information about the fallback.
     ///
-    /// ### Why is this bad?
-    /// For those who are very careful about types, default numeric fallback
-    /// can be a pitfall that cause unexpected runtime behavior.
+    /// ### Why restrict this?
+    /// To ensure that every numeric type is chosen explicitly rather than implicitly.
     ///
     /// ### Known problems
     /// This lint can only be allowed at the function level or above.
diff --git a/clippy_lints/src/default_union_representation.rs b/clippy_lints/src/default_union_representation.rs
index b4290b6437f2..3fa9bad0d03d 100644
--- a/clippy_lints/src/default_union_representation.rs
+++ b/clippy_lints/src/default_union_representation.rs
@@ -10,7 +10,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Displays a warning when a union is declared with the default representation (without a `#[repr(C)]` attribute).
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Unions in Rust have unspecified layout by default, despite many people thinking that they
     /// lay out each field at the start of the union (like C does). That is, there are no guarantees
     /// about the offset of the fields for unions with multiple non-ZST fields without an explicitly
diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs
index c6aef9ac2d60..0276c64ef9b7 100644
--- a/clippy_lints/src/dereference.rs
+++ b/clippy_lints/src/dereference.rs
@@ -2,7 +2,9 @@ use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then};
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::sugg::has_enclosing_paren;
 use clippy_utils::ty::{implements_trait, is_manually_drop, peel_mid_ty_refs};
-use clippy_utils::{expr_use_ctxt, get_parent_expr, is_lint_allowed, path_to_local, DefinedTy, ExprUseNode};
+use clippy_utils::{
+    expr_use_ctxt, get_parent_expr, is_block_like, is_lint_allowed, path_to_local, DefinedTy, ExprUseNode,
+};
 use core::mem;
 use rustc_ast::util::parser::{PREC_POSTFIX, PREC_PREFIX};
 use rustc_data_structures::fx::FxIndexMap;
@@ -1038,14 +1040,8 @@ fn report<'tcx>(
             );
         },
         State::ExplicitDeref { mutability } => {
-            if matches!(
-                expr.kind,
-                ExprKind::Block(..)
-                    | ExprKind::ConstBlock(_)
-                    | ExprKind::If(..)
-                    | ExprKind::Loop(..)
-                    | ExprKind::Match(..)
-            ) && let ty::Ref(_, ty, _) = data.adjusted_ty.kind()
+            if is_block_like(expr)
+                && let ty::Ref(_, ty, _) = data.adjusted_ty.kind()
                 && ty.is_sized(cx.tcx, cx.param_env)
             {
                 // Rustc bug: auto deref doesn't work on block expression when targeting sized types.
diff --git a/clippy_lints/src/derive.rs b/clippy_lints/src/derive.rs
index 2a644922fb1c..636698e96f6d 100644
--- a/clippy_lints/src/derive.rs
+++ b/clippy_lints/src/derive.rs
@@ -1,17 +1,17 @@
-use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::diagnostics::{span_lint_and_note, span_lint_and_then, span_lint_hir_and_then};
 use clippy_utils::ty::{implements_trait, implements_trait_with_env, is_copy};
 use clippy_utils::{has_non_exhaustive_attr, is_lint_allowed, match_def_path, paths};
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
 use rustc_hir::{
-    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Safety, Impl, Item, ItemKind, UnsafeSource,
+    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Impl, Item, ItemKind, Safety, UnsafeSource,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::traits::Reveal;
 use rustc_middle::ty::{
-    self, ClauseKind, GenericArgKind, GenericParamDefKind, ParamEnv, Upcast, TraitPredicate, Ty, TyCtxt,
+    self, ClauseKind, GenericArgKind, GenericParamDefKind, ParamEnv, TraitPredicate, Ty, TyCtxt, Upcast,
 };
 use rustc_session::declare_lint_pass;
 use rustc_span::def_id::LocalDefId;
@@ -390,13 +390,17 @@ fn check_unsafe_derive_deserialize<'tcx>(
             .map(|imp_did| cx.tcx.hir().expect_item(imp_did.expect_local()))
             .any(|imp| has_unsafe(cx, imp))
     {
-        span_lint_and_help(
+        span_lint_hir_and_then(
             cx,
             UNSAFE_DERIVE_DESERIALIZE,
+            adt_hir_id,
             item.span,
             "you are deriving `serde::Deserialize` on a type that has methods using `unsafe`",
-            None,
-            "consider implementing `serde::Deserialize` manually. See https://serde.rs/impl-deserialize.html",
+            |diag| {
+                diag.help(
+                    "consider implementing `serde::Deserialize` manually. See https://serde.rs/impl-deserialize.html",
+                );
+            },
         );
     }
 }
@@ -452,20 +456,27 @@ fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_r
         && !has_non_exhaustive_attr(cx.tcx, *adt)
         && !ty_implements_eq_trait(cx.tcx, ty, eq_trait_def_id)
         && let param_env = param_env_for_derived_eq(cx.tcx, adt.did(), eq_trait_def_id)
+        && let Some(local_def_id) = adt.did().as_local()
         // If all of our fields implement `Eq`, we can implement `Eq` too
         && adt
             .all_fields()
             .map(|f| f.ty(cx.tcx, args))
             .all(|ty| implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, None, &[]))
     {
-        span_lint_and_sugg(
+        span_lint_hir_and_then(
             cx,
             DERIVE_PARTIAL_EQ_WITHOUT_EQ,
+            cx.tcx.local_def_id_to_hir_id(local_def_id),
             span.ctxt().outer_expn_data().call_site,
             "you are deriving `PartialEq` and can implement `Eq`",
-            "consider deriving `Eq` as well",
-            "PartialEq, Eq".to_string(),
-            Applicability::MachineApplicable,
+            |diag| {
+                diag.span_suggestion(
+                    span.ctxt().outer_expn_data().call_site,
+                    "consider deriving `Eq` as well",
+                    "PartialEq, Eq",
+                    Applicability::MachineApplicable,
+                );
+            },
         );
     }
 }
diff --git a/clippy_lints/src/disallowed_script_idents.rs b/clippy_lints/src/disallowed_script_idents.rs
index def4b5932b4b..a995f06fb73d 100644
--- a/clippy_lints/src/disallowed_script_idents.rs
+++ b/clippy_lints/src/disallowed_script_idents.rs
@@ -20,11 +20,11 @@ declare_clippy_lint! {
     /// [aliases]: http://www.unicode.org/reports/tr24/tr24-31.html#Script_Value_Aliases
     /// [supported_scripts]: https://www.unicode.org/iso15924/iso15924-codes.html
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// It may be not desired to have many different scripts for
     /// identifiers in the codebase.
     ///
-    /// Note that if you only want to allow plain English, you might want to use
+    /// Note that if you only want to allow typical English, you might want to use
     /// built-in [`non_ascii_idents`] lint instead.
     ///
     /// [`non_ascii_idents`]: https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#non-ascii-idents
diff --git a/clippy_lints/src/doc/markdown.rs b/clippy_lints/src/doc/markdown.rs
index 1add02af3101..41c0bcd55adc 100644
--- a/clippy_lints/src/doc/markdown.rs
+++ b/clippy_lints/src/doc/markdown.rs
@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::source::snippet_with_applicability;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{Applicability, SuggestionStyle};
@@ -30,6 +30,7 @@ pub fn check(
             word = tmp_word;
         }
 
+        let original_len = word.len();
         word = word.trim_start_matches(trim_pattern);
 
         // Remove leading or trailing single `:` which may be part of a sentence.
@@ -44,6 +45,25 @@ pub fn check(
             continue;
         }
 
+        // Ensure that all reachable matching closing parens are included as well.
+        let size_diff = original_len - word.len();
+        let mut open_parens = 0;
+        let mut close_parens = 0;
+        for c in word.chars() {
+            if c == '(' {
+                open_parens += 1;
+            } else if c == ')' {
+                close_parens += 1;
+            }
+        }
+        while close_parens < open_parens
+            && let Some(tmp_word) = orig_word.get(size_diff..=(word.len() + size_diff))
+            && tmp_word.ends_with(')')
+        {
+            word = tmp_word;
+            close_parens += 1;
+        }
+
         // Adjust for the current word
         let offset = word.as_ptr() as usize - text.as_ptr() as usize;
         let span = Span::new(
@@ -92,13 +112,15 @@ fn check_word(cx: &LateContext<'_>, word: &str, span: Span, code_level: isize, b
     if let Ok(url) = Url::parse(word) {
         // try to get around the fact that `foo::bar` parses as a valid URL
         if !url.cannot_be_a_base() {
-            span_lint(
+            span_lint_and_sugg(
                 cx,
                 DOC_MARKDOWN,
                 span,
                 "you should put bare URLs between `<`/`>` or make a proper Markdown link",
+                "try",
+                format!("<{word}>"),
+                Applicability::MachineApplicable,
             );
-
             return;
         }
     }
diff --git a/clippy_lints/src/doc/mod.rs b/clippy_lints/src/doc/mod.rs
index 9f08973948a3..3d875e7ac2d3 100644
--- a/clippy_lints/src/doc/mod.rs
+++ b/clippy_lints/src/doc/mod.rs
@@ -261,7 +261,7 @@ declare_clippy_lint! {
     /// Checks for the doc comments of publicly visible
     /// safe functions and traits and warns if there is a `# Safety` section.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Safe functions and traits are safe to implement and therefore do not
     /// need to describe safety preconditions that users are required to uphold.
     ///
diff --git a/clippy_lints/src/drop_forget_ref.rs b/clippy_lints/src/drop_forget_ref.rs
index 119473c2454b..4a6ffcd9a788 100644
--- a/clippy_lints/src/drop_forget_ref.rs
+++ b/clippy_lints/src/drop_forget_ref.rs
@@ -52,9 +52,10 @@ declare_clippy_lint! {
     /// Checks for usage of `std::mem::forget(t)` where `t` is
     /// `Drop` or has a field that implements `Drop`.
     ///
-    /// ### Why is this bad?
-    /// `std::mem::forget(t)` prevents `t` from running its
-    /// destructor, possibly causing leaks.
+    /// ### Why restrict this?
+    /// `std::mem::forget(t)` prevents `t` from running its destructor, possibly causing leaks.
+    /// It is not possible to detect all means of creating leaks, but it may be desirable to
+    /// prohibit the simple ones.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/else_if_without_else.rs b/clippy_lints/src/else_if_without_else.rs
index a6ca7fe9e0bb..bb6f9aac2236 100644
--- a/clippy_lints/src/else_if_without_else.rs
+++ b/clippy_lints/src/else_if_without_else.rs
@@ -11,7 +11,7 @@ declare_clippy_lint! {
     /// Checks for usage of if expressions with an `else if` branch,
     /// but without a final `else` branch.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Some coding guidelines require this (e.g., MISRA-C:2004 Rule 14.10).
     ///
     /// ### Example
diff --git a/clippy_lints/src/empty_drop.rs b/clippy_lints/src/empty_drop.rs
index 74db250b3ae9..c5fc72b5e2d8 100644
--- a/clippy_lints/src/empty_drop.rs
+++ b/clippy_lints/src/empty_drop.rs
@@ -9,7 +9,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for empty `Drop` implementations.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Empty `Drop` implementations have no effect when dropping an instance of the type. They are
     /// most likely useless. However, an empty `Drop` implementation prevents a type from being
     /// destructured, which might be the intention behind adding the implementation as a marker.
diff --git a/clippy_lints/src/empty_enum.rs b/clippy_lints/src/empty_enum.rs
index 420888b6ccb3..d16714695cb7 100644
--- a/clippy_lints/src/empty_enum.rs
+++ b/clippy_lints/src/empty_enum.rs
@@ -7,32 +7,53 @@ use rustc_session::declare_lint_pass;
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for `enum`s with no variants.
+    /// Checks for `enum`s with no variants, which therefore are uninhabited types
+    /// (cannot be instantiated).
     ///
-    /// As of this writing, the `never_type` is still a
-    /// nightly-only experimental API. Therefore, this lint is only triggered
-    /// if the `never_type` is enabled.
+    /// As of this writing, the `never_type` is still a nightly-only experimental API.
+    /// Therefore, this lint is only triggered if `#![feature(never_type)]` is enabled.
     ///
     /// ### Why is this bad?
-    /// If you want to introduce a type which
-    /// can't be instantiated, you should use `!` (the primitive type "never"),
-    /// or a wrapper around it, because `!` has more extensive
-    /// compiler support (type inference, etc...) and wrappers
-    /// around it are the conventional way to define an uninhabited type.
-    /// For further information visit [never type documentation](https://doc.rust-lang.org/std/primitive.never.html)
+    /// * If you only want a type which can’t be instantiated, you should use [`!`]
+    ///   (the primitive type "never"), because [`!`] has more extensive compiler support
+    ///   (type inference, etc.) and implementations of common traits.
     ///
+    /// * If you need to introduce a distinct type, consider using a [newtype] `struct`
+    ///   containing [`!`] instead (`struct MyType(pub !)`), because it is more idiomatic
+    ///   to use a `struct` rather than an `enum` when an `enum` is unnecessary.
+    ///
+    ///   If you do this, note that the [visibility] of the [`!`] field determines whether
+    ///   the uninhabitedness is visible in documentation, and whether it can be pattern
+    ///   matched to mark code unreachable. If the field is not visible, then the struct
+    ///   acts like any other struct with private fields.
+    ///
+    /// * If the enum has no variants only because all variants happen to be
+    ///   [disabled by conditional compilation][cfg], then it would be appropriate
+    ///   to allow the lint, with `#[allow(empty_enum)]`.
+    ///
+    /// For further information, visit
+    /// [the never type’s documentation][`!`].
     ///
     /// ### Example
     /// ```no_run
-    /// enum Test {}
+    /// enum CannotExist {}
     /// ```
     ///
     /// Use instead:
     /// ```no_run
     /// #![feature(never_type)]
     ///
-    /// struct Test(!);
+    /// /// Use the `!` type directly...
+    /// type CannotExist = !;
+    ///
+    /// /// ...or define a newtype which is distinct.
+    /// struct CannotExist2(pub !);
     /// ```
+    ///
+    /// [`!`]: https://doc.rust-lang.org/std/primitive.never.html
+    /// [cfg]: https://doc.rust-lang.org/reference/conditional-compilation.html
+    /// [newtype]: https://doc.rust-lang.org/book/ch19-04-advanced-types.html#using-the-newtype-pattern-for-type-safety-and-abstraction
+    /// [visibility]: https://doc.rust-lang.org/reference/visibility-and-privacy.html
     #[clippy::version = "pre 1.29.0"]
     pub EMPTY_ENUM,
     pedantic,
diff --git a/clippy_lints/src/empty_with_brackets.rs b/clippy_lints/src/empty_with_brackets.rs
index 969df6d85b5a..745599b0e57a 100644
--- a/clippy_lints/src/empty_with_brackets.rs
+++ b/clippy_lints/src/empty_with_brackets.rs
@@ -11,16 +11,23 @@ declare_clippy_lint! {
     /// ### What it does
     /// Finds structs without fields (a so-called "empty struct") that are declared with brackets.
     ///
-    /// ### Why is this bad?
-    /// Empty brackets after a struct declaration can be omitted.
+    /// ### Why restrict this?
+    /// Empty brackets after a struct declaration can be omitted,
+    /// and it may be desirable to do so consistently for style.
+    ///
+    /// However, removing the brackets also introduces a public constant named after the struct,
+    /// so this is not just a syntactic simplification but an an API change, and adding them back
+    /// is a *breaking* API change.
     ///
     /// ### Example
     /// ```no_run
     /// struct Cookie {}
+    /// struct Biscuit();
     /// ```
     /// Use instead:
     /// ```no_run
     /// struct Cookie;
+    /// struct Biscuit;
     /// ```
     #[clippy::version = "1.62.0"]
     pub EMPTY_STRUCTS_WITH_BRACKETS,
@@ -32,14 +39,20 @@ declare_clippy_lint! {
     /// ### What it does
     /// Finds enum variants without fields that are declared with empty brackets.
     ///
-    /// ### Why is this bad?
-    /// Empty brackets while defining enum variants are redundant and can be omitted.
+    /// ### Why restrict this?
+    /// Empty brackets after a enum variant declaration are redundant and can be omitted,
+    /// and it may be desirable to do so consistently for style.
+    ///
+    /// However, removing the brackets also introduces a public constant named after the variant,
+    /// so this is not just a syntactic simplification but an an API change, and adding them back
+    /// is a *breaking* API change.
     ///
     /// ### Example
     /// ```no_run
     /// enum MyEnum {
     ///     HasData(u8),
-    ///     HasNoData(), // redundant parentheses
+    ///     HasNoData(),       // redundant parentheses
+    ///     NoneHereEither {}, // redundant braces
     /// }
     /// ```
     ///
@@ -48,6 +61,7 @@ declare_clippy_lint! {
     /// enum MyEnum {
     ///     HasData(u8),
     ///     HasNoData,
+    ///     NoneHereEither,
     /// }
     /// ```
     #[clippy::version = "1.77.0"]
diff --git a/clippy_lints/src/endian_bytes.rs b/clippy_lints/src/endian_bytes.rs
index dd03df797de3..bb766e963387 100644
--- a/clippy_lints/src/endian_bytes.rs
+++ b/clippy_lints/src/endian_bytes.rs
@@ -13,8 +13,9 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for the usage of the `to_ne_bytes` method and/or the function `from_ne_bytes`.
     ///
-    /// ### Why is this bad?
-    /// It's not, but some may prefer to specify the target endianness explicitly.
+    /// ### Why restrict this?
+    /// To ensure use of explicitly chosen endianness rather than the target’s endianness,
+    /// such as when implementing network protocols or file formats rather than FFI.
     ///
     /// ### Example
     /// ```rust,ignore
@@ -31,9 +32,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for the usage of the `to_le_bytes` method and/or the function `from_le_bytes`.
     ///
-    /// ### Why is this bad?
-    /// It's not, but some may wish to lint usage of this method, either to suggest using the host
-    /// endianness or big endian.
+    /// ### Why restrict this?
+    /// To ensure use of big endian or the target’s endianness rather than little endian.
     ///
     /// ### Example
     /// ```rust,ignore
@@ -50,9 +50,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for the usage of the `to_be_bytes` method and/or the function `from_be_bytes`.
     ///
-    /// ### Why is this bad?
-    /// It's not, but some may wish to lint usage of this method, either to suggest using the host
-    /// endianness or little endian.
+    /// ### Why restrict this?
+    /// To ensure use of little endian or the target’s endianness rather than big endian.
     ///
     /// ### Example
     /// ```rust,ignore
diff --git a/clippy_lints/src/error_impl_error.rs b/clippy_lints/src/error_impl_error.rs
index 8dbb47fadc5d..8e49138cd26b 100644
--- a/clippy_lints/src/error_impl_error.rs
+++ b/clippy_lints/src/error_impl_error.rs
@@ -12,7 +12,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for types named `Error` that implement `Error`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// It can become confusing when a codebase has 20 types all named `Error`, requiring either
     /// aliasing them in the `use` statement or qualifying them like `my_module::Error`. This
     /// hinders comprehension, as it requires you to memorize every variation of importing `Error`
diff --git a/clippy_lints/src/exhaustive_items.rs b/clippy_lints/src/exhaustive_items.rs
index 9ffda6457424..436dc8611bde 100644
--- a/clippy_lints/src/exhaustive_items.rs
+++ b/clippy_lints/src/exhaustive_items.rs
@@ -10,10 +10,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// Warns on any exported `enum`s that are not tagged `#[non_exhaustive]`
     ///
-    /// ### Why is this bad?
-    /// Exhaustive enums are typically fine, but a project which does
-    /// not wish to make a stability commitment around exported enums may wish to
-    /// disable them by default.
+    /// ### Why restrict this?
+    /// Making an `enum` exhaustive is a stability commitment: adding a variant is a breaking change.
+    /// A project may wish to ensure that there are no exhaustive enums or that every exhaustive
+    /// `enum` is explicitly `#[allow]`ed.
     ///
     /// ### Example
     /// ```no_run
@@ -40,10 +40,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// Warns on any exported `struct`s that are not tagged `#[non_exhaustive]`
     ///
-    /// ### Why is this bad?
-    /// Exhaustive structs are typically fine, but a project which does
-    /// not wish to make a stability commitment around exported structs may wish to
-    /// disable them by default.
+    /// ### Why restrict this?
+    /// Making a `struct` exhaustive is a stability commitment: adding a field is a breaking change.
+    /// A project may wish to ensure that there are no exhaustive structs or that every exhaustive
+    /// `struct` is explicitly `#[allow]`ed.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/exit.rs b/clippy_lints/src/exit.rs
index 106844dd4348..91c94d66458d 100644
--- a/clippy_lints/src/exit.rs
+++ b/clippy_lints/src/exit.rs
@@ -9,11 +9,13 @@ declare_clippy_lint! {
     /// ### What it does
     /// Detects calls to the `exit()` function which terminates the program.
     ///
-    /// ### Why is this bad?
-    /// Exit terminates the program at the location it is called. For unrecoverable
-    /// errors `panics` should be used to provide a stacktrace and potentially other
-    /// information. A normal termination or one with an error code should happen in
-    /// the main function.
+    /// ### Why restrict this?
+    /// `exit()` immediately terminates the program with no information other than an exit code.
+    /// This provides no means to troubleshoot a problem, and may be an unexpected side effect.
+    ///
+    /// Codebases may use this lint to require that all exits are performed either by panicking
+    /// (which produces a message, a code location, and optionally a backtrace)
+    /// or by returning from `main()` (which is a single place to look).
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/float_literal.rs b/clippy_lints/src/float_literal.rs
index 2cd4e9e99a56..4ec9bd757ff4 100644
--- a/clippy_lints/src/float_literal.rs
+++ b/clippy_lints/src/float_literal.rs
@@ -38,9 +38,9 @@ declare_clippy_lint! {
     /// Checks for whole number float literals that
     /// cannot be represented as the underlying type without loss.
     ///
-    /// ### Why is this bad?
-    /// Rust will silently lose precision during
-    /// conversion to a float.
+    /// ### Why restrict this?
+    /// If the value was intended to be exact, it will not be.
+    /// This may be especially surprising when the lost precision is to the left of the decimal point.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/format_push_string.rs b/clippy_lints/src/format_push_string.rs
index 2b08437d8271..a75538dd329b 100644
--- a/clippy_lints/src/format_push_string.rs
+++ b/clippy_lints/src/format_push_string.rs
@@ -11,7 +11,7 @@ declare_clippy_lint! {
     /// Detects cases where the result of a `format!` call is
     /// appended to an existing `String`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Introduces an extra, avoidable heap allocation.
     ///
     /// ### Known problems
diff --git a/clippy_lints/src/functions/misnamed_getters.rs b/clippy_lints/src/functions/misnamed_getters.rs
index 7729c556e1fc..2cbc4b072341 100644
--- a/clippy_lints/src/functions/misnamed_getters.rs
+++ b/clippy_lints/src/functions/misnamed_getters.rs
@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, ExprKind, FnDecl, Safety, ImplicitSelfKind};
+use rustc_hir::{Body, ExprKind, FnDecl, ImplicitSelfKind, Safety};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::Span;
diff --git a/clippy_lints/src/functions/mod.rs b/clippy_lints/src/functions/mod.rs
index dfcaac9abefc..26534492dddd 100644
--- a/clippy_lints/src/functions/mod.rs
+++ b/clippy_lints/src/functions/mod.rs
@@ -338,8 +338,10 @@ declare_clippy_lint! {
 declare_clippy_lint! {
     /// ### What it does
     /// Lints when `impl Trait` is being used in a function's parameters.
-    /// ### Why is this bad?
-    /// Turbofish syntax (`::<>`) cannot be used when `impl Trait` is being used, making `impl Trait` less powerful. Readability may also be a factor.
+    ///
+    /// ### Why restrict this?
+    /// Turbofish syntax (`::<>`) cannot be used to specify the type of an `impl Trait` parameter,
+    /// making `impl Trait` less powerful. Readability may also be a factor.
     ///
     /// ### Example
     /// ```no_run
@@ -366,9 +368,8 @@ declare_clippy_lint! {
     /// Lints when the name of function parameters from trait impl is
     /// different than its default implementation.
     ///
-    /// ### Why is this bad?
-    /// Using the default name for parameters of a trait method is often
-    /// more desirable for consistency's sake.
+    /// ### Why restrict this?
+    /// Using the default name for parameters of a trait method is more consistent.
     ///
     /// ### Example
     /// ```rust
diff --git a/clippy_lints/src/if_then_some_else_none.rs b/clippy_lints/src/if_then_some_else_none.rs
index f5ba62ae432e..0b2008152198 100644
--- a/clippy_lints/src/if_then_some_else_none.rs
+++ b/clippy_lints/src/if_then_some_else_none.rs
@@ -15,7 +15,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for if-else that could be written using either `bool::then` or `bool::then_some`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Looks a little redundant. Using `bool::then` is more concise and incurs no loss of clarity.
     /// For simple calculations and known values, use `bool::then_some`, which is eagerly evaluated
     /// in comparison to `bool::then`.
diff --git a/clippy_lints/src/implicit_return.rs b/clippy_lints/src/implicit_return.rs
index 5288efd8df8c..cc342007ec61 100644
--- a/clippy_lints/src/implicit_return.rs
+++ b/clippy_lints/src/implicit_return.rs
@@ -16,12 +16,13 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for missing return statements at the end of a block.
     ///
-    /// ### Why is this bad?
-    /// Actually omitting the return keyword is idiomatic Rust code. Programmers
-    /// coming from other languages might prefer the expressiveness of `return`. It's possible to miss
-    /// the last returning statement because the only difference is a missing `;`. Especially in bigger
-    /// code with multiple return paths having a `return` keyword makes it easier to find the
-    /// corresponding statements.
+    /// ### Why restrict this?
+    /// Omitting the return keyword whenever possible is idiomatic Rust code, but:
+    ///
+    /// * Programmers coming from other languages might prefer the expressiveness of `return`.
+    /// * It's possible to miss the last returning statement because the only difference is a missing `;`.
+    /// * Especially in bigger code with multiple return paths, having a `return` keyword makes it easier to find the
+    ///   corresponding statements.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 35fcd8cdd354..e3e79749bea6 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -45,9 +45,10 @@ declare_clippy_lint! {
     /// does report on arrays if we can tell that slicing operations are in bounds and does not
     /// lint on constant `usize` indexing on arrays because that is handled by rustc's `const_err` lint.
     ///
-    /// ### Why is this bad?
-    /// Indexing and slicing can panic at runtime and there are
-    /// safe alternatives.
+    /// ### Why restrict this?
+    /// To avoid implicit panics from indexing and slicing.
+    /// There are “checked” alternatives which do not panic, and can be used with `unwrap()` to make
+    /// an explicit panic when it is desired.
     ///
     /// ### Example
     /// ```rust,no_run
diff --git a/clippy_lints/src/inherent_impl.rs b/clippy_lints/src/inherent_impl.rs
index 1127f00abde0..95ae591884bc 100644
--- a/clippy_lints/src/inherent_impl.rs
+++ b/clippy_lints/src/inherent_impl.rs
@@ -14,7 +14,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for multiple inherent implementations of a struct
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Splitting the implementation of a type makes the code harder to navigate.
     ///
     /// ### Example
diff --git a/clippy_lints/src/init_numbered_fields.rs b/clippy_lints/src/init_numbered_fields.rs
index e486563808a5..1c8fd0a27f98 100644
--- a/clippy_lints/src/init_numbered_fields.rs
+++ b/clippy_lints/src/init_numbered_fields.rs
@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use rustc_errors::Applicability;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{Expr, ExprKind};
@@ -62,7 +62,7 @@ impl<'tcx> LateLintPass<'tcx> for NumberedFields {
                     snippet_with_applicability(cx, path.span(), "..", &mut appl),
                     expr_spans
                         .into_iter_sorted()
-                        .map(|(_, span)| snippet_with_applicability(cx, span, "..", &mut appl))
+                        .map(|(_, span)| snippet_with_context(cx, span, path.span().ctxt(), "..", &mut appl).0)
                         .intersperse(Cow::Borrowed(", "))
                         .collect::<String>()
                 );
diff --git a/clippy_lints/src/integer_division_remainder_used.rs b/clippy_lints/src/integer_division_remainder_used.rs
index a3577b765c03..cf598d5045ec 100644
--- a/clippy_lints/src/integer_division_remainder_used.rs
+++ b/clippy_lints/src/integer_division_remainder_used.rs
@@ -7,10 +7,10 @@ use rustc_session::declare_lint_pass;
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for the usage of division (/) and remainder (%) operations
-    /// when performed on any integer types using the default Div and Rem trait implementations.
+    /// Checks for the usage of division (`/`) and remainder (`%`) operations
+    /// when performed on any integer types using the default `Div` and `Rem` trait implementations.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// In cryptographic contexts, division can result in timing sidechannel vulnerabilities,
     /// and needs to be replaced with constant-time code instead (e.g. Barrett reduction).
     ///
diff --git a/clippy_lints/src/iter_over_hash_type.rs b/clippy_lints/src/iter_over_hash_type.rs
index 6c6eff9ba48b..fb29d9824179 100644
--- a/clippy_lints/src/iter_over_hash_type.rs
+++ b/clippy_lints/src/iter_over_hash_type.rs
@@ -14,8 +14,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// This is a restriction lint which prevents the use of hash types (i.e., `HashSet` and `HashMap`) in for loops.
     ///
-    /// ### Why is this bad?
-    /// Because hash types are unordered, when iterated through such as in a for loop, the values are returned in
+    /// ### Why restrict this?
+    /// Because hash types are unordered, when iterated through such as in a `for` loop, the values are returned in
     /// an undefined order. As a result, on redundant systems this may cause inconsistencies and anomalies.
     /// In addition, the unknown order of the elements may reduce readability or introduce other undesired
     /// side effects.
diff --git a/clippy_lints/src/large_include_file.rs b/clippy_lints/src/large_include_file.rs
index 790bed580fd1..07efee159aab 100644
--- a/clippy_lints/src/large_include_file.rs
+++ b/clippy_lints/src/large_include_file.rs
@@ -10,10 +10,12 @@ use rustc_span::sym;
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for the inclusion of large files via `include_bytes!()`
-    /// and `include_str!()`
+    /// or `include_str!()`.
     ///
-    /// ### Why is this bad?
-    /// Including large files can increase the size of the binary
+    /// ### Why restrict this?
+    /// Including large files can undesirably increase the size of the binary produced by the compiler.
+    /// This lint may be used to catch mistakes where an unexpectedly large file is included, or
+    /// temporarily to obtain a list of all large files.
     ///
     /// ### Example
     /// ```rust,ignore
diff --git a/clippy_lints/src/let_underscore.rs b/clippy_lints/src/let_underscore.rs
index 619e933b4fff..9fd4f509aa47 100644
--- a/clippy_lints/src/let_underscore.rs
+++ b/clippy_lints/src/let_underscore.rs
@@ -12,9 +12,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `let _ = <expr>` where expr is `#[must_use]`
     ///
-    /// ### Why is this bad?
-    /// It's better to explicitly handle the value of a `#[must_use]`
-    /// expr
+    /// ### Why restrict this?
+    /// To ensure that all `#[must_use]` types are used rather than ignored.
     ///
     /// ### Example
     /// ```no_run
@@ -96,8 +95,8 @@ declare_clippy_lint! {
     /// Checks for `let _ = <expr>` without a type annotation, and suggests to either provide one,
     /// or remove the `let` keyword altogether.
     ///
-    /// ### Why is this bad?
-    /// The `let _ = <expr>` expression ignores the value of `<expr>` but will remain doing so even
+    /// ### Why restrict this?
+    /// The `let _ = <expr>` expression ignores the value of `<expr>`, but will continue to do so even
     /// if the type were to change, thus potentially introducing subtle bugs. By supplying a type
     /// annotation, one will be forced to re-visit the decision to ignore the value in such cases.
     ///
diff --git a/clippy_lints/src/literal_representation.rs b/clippy_lints/src/literal_representation.rs
index 2348dd18220f..d2a140a36a83 100644
--- a/clippy_lints/src/literal_representation.rs
+++ b/clippy_lints/src/literal_representation.rs
@@ -132,8 +132,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Warns if there is a better representation for a numeric literal.
     ///
-    /// ### Why is this bad?
-    /// Especially for big powers of 2 a hexadecimal representation is more
+    /// ### Why restrict this?
+    /// Especially for big powers of 2, a hexadecimal representation is usually more
     /// readable than a decimal representation.
     ///
     /// ### Example
diff --git a/clippy_lints/src/loops/mod.rs b/clippy_lints/src/loops/mod.rs
index 3dcb050d77e6..086829421530 100644
--- a/clippy_lints/src/loops/mod.rs
+++ b/clippy_lints/src/loops/mod.rs
@@ -675,9 +675,9 @@ declare_clippy_lint! {
     /// Checks for infinite loops in a function where the return type is not `!`
     /// and lint accordingly.
     ///
-    /// ### Why is this bad?
-    /// A loop should be gently exited somewhere, or at least mark its parent function as
-    /// never return (`!`).
+    /// ### Why restrict this?
+    /// Making the return type `!` serves as documentation that the function does not return.
+    /// If the function is not intended to loop infinitely, then this lint may detect a bug.
     ///
     /// ### Example
     /// ```no_run,ignore
diff --git a/clippy_lints/src/matches/mod.rs b/clippy_lints/src/matches/mod.rs
index ee9f48d71ad8..691ecd57535a 100644
--- a/clippy_lints/src/matches/mod.rs
+++ b/clippy_lints/src/matches/mod.rs
@@ -260,7 +260,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for wildcard enum matches using `_`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// New enum variants added by library updates can be missed.
     ///
     /// ### Known problems
@@ -435,7 +435,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for unnecessary '..' pattern binding on struct when all fields are explicitly matched.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Correctness and readability. It's like having a wildcard pattern after
     /// matching all enum variants explicitly.
     ///
@@ -861,7 +861,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `Err(x)?`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// The `?` operator is designed to allow calls that
     /// can fail to be easily chained. For example, `foo()?.bar()` or
     /// `foo(bar()?)`. Because `Err(x)?` can't be used that way (it will
diff --git a/clippy_lints/src/matches/significant_drop_in_scrutinee.rs b/clippy_lints/src/matches/significant_drop_in_scrutinee.rs
index 6ac0705abb21..2f72e59834fa 100644
--- a/clippy_lints/src/matches/significant_drop_in_scrutinee.rs
+++ b/clippy_lints/src/matches/significant_drop_in_scrutinee.rs
@@ -1,12 +1,17 @@
+use std::ops::ControlFlow;
+
 use crate::FxHashSet;
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::{indent_of, snippet};
+use clippy_utils::ty::{for_each_top_level_late_bound_region, is_copy};
 use clippy_utils::{get_attr, is_lint_allowed};
+use itertools::Itertools;
+use rustc_ast::Mutability;
 use rustc_errors::{Applicability, Diag};
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{Arm, Expr, ExprKind, MatchSource};
 use rustc_lint::{LateContext, LintContext};
-use rustc_middle::ty::{GenericArgKind, Ty};
+use rustc_middle::ty::{GenericArgKind, Region, RegionKind, Ty, TyCtxt, TypeVisitable, TypeVisitor};
 use rustc_span::Span;
 
 use super::SIGNIFICANT_DROP_IN_SCRUTINEE;
@@ -22,43 +27,34 @@ pub(super) fn check<'tcx>(
         return;
     }
 
-    if let Some((suggestions, message)) = has_significant_drop_in_scrutinee(cx, scrutinee, source) {
-        for found in suggestions {
-            span_lint_and_then(cx, SIGNIFICANT_DROP_IN_SCRUTINEE, found.found_span, message, |diag| {
-                set_diagnostic(diag, cx, expr, found);
-                let s = Span::new(expr.span.hi(), expr.span.hi(), expr.span.ctxt(), None);
-                diag.span_label(s, "temporary lives until here");
-                for span in has_significant_drop_in_arms(cx, arms) {
-                    diag.span_label(span, "another value with significant `Drop` created here");
-                }
-                diag.note("this might lead to deadlocks or other unexpected behavior");
-            });
-        }
+    let (suggestions, message) = has_significant_drop_in_scrutinee(cx, scrutinee, source);
+    for found in suggestions {
+        span_lint_and_then(cx, SIGNIFICANT_DROP_IN_SCRUTINEE, found.found_span, message, |diag| {
+            set_diagnostic(diag, cx, expr, found);
+            let s = Span::new(expr.span.hi(), expr.span.hi(), expr.span.ctxt(), None);
+            diag.span_label(s, "temporary lives until here");
+            for span in has_significant_drop_in_arms(cx, arms) {
+                diag.span_label(span, "another value with significant `Drop` created here");
+            }
+            diag.note("this might lead to deadlocks or other unexpected behavior");
+        });
     }
 }
 
 fn set_diagnostic<'tcx>(diag: &mut Diag<'_, ()>, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, found: FoundSigDrop) {
-    if found.lint_suggestion == LintSuggestion::MoveAndClone {
-        // If our suggestion is to move and clone, then we want to leave it to the user to
-        // decide how to address this lint, since it may be that cloning is inappropriate.
-        // Therefore, we won't to emit a suggestion.
-        return;
-    }
-
     let original = snippet(cx, found.found_span, "..");
     let trailing_indent = " ".repeat(indent_of(cx, found.found_span).unwrap_or(0));
 
-    let replacement = if found.lint_suggestion == LintSuggestion::MoveAndDerefToCopy {
-        format!("let value = *{original};\n{trailing_indent}")
-    } else if found.is_unit_return_val {
-        // If the return value of the expression to be moved is unit, then we don't need to
-        // capture the result in a temporary -- we can just replace it completely with `()`.
-        format!("{original};\n{trailing_indent}")
-    } else {
-        format!("let value = {original};\n{trailing_indent}")
+    let replacement = {
+        let (def_part, deref_part) = if found.is_unit_return_val {
+            ("", String::new())
+        } else {
+            ("let value = ", "*".repeat(found.peel_ref_times))
+        };
+        format!("{def_part}{deref_part}{original};\n{trailing_indent}")
     };
 
-    let suggestion_message = if found.lint_suggestion == LintSuggestion::MoveOnly {
+    let suggestion_message = if found.peel_ref_times == 0 {
         "try moving the temporary above the match"
     } else {
         "try moving the temporary above the match and create a copy"
@@ -66,8 +62,11 @@ fn set_diagnostic<'tcx>(diag: &mut Diag<'_, ()>, cx: &LateContext<'tcx>, expr: &
 
     let scrutinee_replacement = if found.is_unit_return_val {
         "()".to_owned()
-    } else {
+    } else if found.peel_ref_times == 0 {
         "value".to_owned()
+    } else {
+        let ref_part = "&".repeat(found.peel_ref_times);
+        format!("({ref_part}value)")
     };
 
     diag.multipart_suggestion(
@@ -86,20 +85,18 @@ fn has_significant_drop_in_scrutinee<'tcx>(
     cx: &LateContext<'tcx>,
     scrutinee: &'tcx Expr<'tcx>,
     source: MatchSource,
-) -> Option<(Vec<FoundSigDrop>, &'static str)> {
+) -> (Vec<FoundSigDrop>, &'static str) {
     let mut helper = SigDropHelper::new(cx);
     let scrutinee = match (source, &scrutinee.kind) {
         (MatchSource::ForLoopDesugar, ExprKind::Call(_, [e])) => e,
         _ => scrutinee,
     };
-    helper.find_sig_drop(scrutinee).map(|drops| {
-        let message = if source == MatchSource::Normal {
-            "temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression"
-        } else {
-            "temporary with significant `Drop` in `for` loop condition will live until the end of the `for` expression"
-        };
-        (drops, message)
-    })
+    let message = if source == MatchSource::Normal {
+        "temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression"
+    } else {
+        "temporary with significant `Drop` in `for` loop condition will live until the end of the `for` expression"
+    };
+    (helper.find_sig_drop(scrutinee), message)
 }
 
 struct SigDropChecker<'a, 'tcx> {
@@ -172,205 +169,248 @@ impl<'a, 'tcx> SigDropChecker<'a, 'tcx> {
     }
 }
 
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug)]
+enum SigDropHolder {
+    /// No values with significant drop present in this expression.
+    ///
+    /// Expressions that we've emited lints do not count.
+    None,
+    /// Some field in this expression references to values with significant drop.
+    ///
+    /// Example: `(1, &data.lock().field)`.
+    PackedRef,
+    /// The value of this expression references to values with significant drop.
+    ///
+    /// Example: `data.lock().field`.
+    DirectRef,
+    /// This expression should be moved out to avoid significant drop in scrutinee.
+    Moved,
+}
+
+impl Default for SigDropHolder {
+    fn default() -> Self {
+        Self::None
+    }
+}
+
 struct SigDropHelper<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
-    is_chain_end: bool,
-    has_significant_drop: bool,
-    current_sig_drop: Option<FoundSigDrop>,
-    sig_drop_spans: Option<Vec<FoundSigDrop>>,
-    special_handling_for_binary_op: bool,
+    parent_expr: Option<&'tcx Expr<'tcx>>,
+    sig_drop_holder: SigDropHolder,
+    sig_drop_spans: Vec<FoundSigDrop>,
     sig_drop_checker: SigDropChecker<'a, 'tcx>,
 }
 
-#[expect(clippy::enum_variant_names)]
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-enum LintSuggestion {
-    MoveOnly,
-    MoveAndDerefToCopy,
-    MoveAndClone,
-}
-
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 struct FoundSigDrop {
     found_span: Span,
     is_unit_return_val: bool,
-    lint_suggestion: LintSuggestion,
+    peel_ref_times: usize,
 }
 
 impl<'a, 'tcx> SigDropHelper<'a, 'tcx> {
     fn new(cx: &'a LateContext<'tcx>) -> SigDropHelper<'a, 'tcx> {
         SigDropHelper {
             cx,
-            is_chain_end: true,
-            has_significant_drop: false,
-            current_sig_drop: None,
-            sig_drop_spans: None,
-            special_handling_for_binary_op: false,
+            parent_expr: None,
+            sig_drop_holder: SigDropHolder::None,
+            sig_drop_spans: Vec::new(),
             sig_drop_checker: SigDropChecker::new(cx),
         }
     }
 
-    fn find_sig_drop(&mut self, match_expr: &'tcx Expr<'_>) -> Option<Vec<FoundSigDrop>> {
+    fn find_sig_drop(&mut self, match_expr: &'tcx Expr<'_>) -> Vec<FoundSigDrop> {
         self.visit_expr(match_expr);
 
-        // If sig drop spans is empty but we found a significant drop, it means that we didn't find
-        // a type that was trivially copyable as we moved up the chain after finding a significant
-        // drop, so move the entire scrutinee.
-        if self.has_significant_drop && self.sig_drop_spans.is_none() {
-            self.try_setting_current_suggestion(match_expr, true);
-            self.move_current_suggestion();
-        }
-
-        self.sig_drop_spans.take()
+        core::mem::take(&mut self.sig_drop_spans)
     }
 
-    fn replace_current_sig_drop(
-        &mut self,
-        found_span: Span,
-        is_unit_return_val: bool,
-        lint_suggestion: LintSuggestion,
-    ) {
-        self.current_sig_drop.replace(FoundSigDrop {
+    fn replace_current_sig_drop(&mut self, found_span: Span, is_unit_return_val: bool, peel_ref_times: usize) {
+        self.sig_drop_spans.clear();
+        self.sig_drop_spans.push(FoundSigDrop {
             found_span,
             is_unit_return_val,
-            lint_suggestion,
+            peel_ref_times,
         });
     }
 
-    /// This will try to set the current suggestion (so it can be moved into the suggestions vec
-    /// later). If `allow_move_and_clone` is false, the suggestion *won't* be set -- this gives us
-    /// an opportunity to look for another type in the chain that will be trivially copyable.
-    /// However, if we are at the end of the chain, we want to accept whatever is there. (The
-    /// suggestion won't actually be output, but the diagnostic message will be output, so the user
-    /// can determine the best way to handle the lint.)
-    fn try_setting_current_suggestion(&mut self, expr: &'tcx Expr<'_>, allow_move_and_clone: bool) {
-        if self.current_sig_drop.is_some() {
-            return;
+    fn try_move_sig_drop(&mut self, expr: &'tcx Expr<'_>, parent_expr: &'tcx Expr<'_>) {
+        if self.sig_drop_holder == SigDropHolder::Moved {
+            self.sig_drop_holder = SigDropHolder::None;
         }
-        let ty = self.cx.typeck_results().expr_ty(expr);
-        if ty.is_ref() {
-            // We checked that the type was ref, so builtin_deref will return Some,
-            // but let's avoid any chance of an ICE.
-            if let Some(ty) = ty.builtin_deref(true) {
-                if ty.is_trivially_pure_clone_copy() {
-                    self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveAndDerefToCopy);
-                } else if allow_move_and_clone {
-                    self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveAndClone);
-                }
+
+        if self.sig_drop_holder == SigDropHolder::DirectRef {
+            self.sig_drop_holder = SigDropHolder::PackedRef;
+            self.try_move_sig_drop_direct_ref(expr, parent_expr);
+        } else if self.sig_drop_checker.is_sig_drop_expr(expr) {
+            // The values with significant drop can be moved to some other functions. For example, consider
+            // `drop(data.lock())`. We use `SigDropHolder::None` here to avoid emitting lints in such scenarios.
+            self.sig_drop_holder = SigDropHolder::None;
+            self.try_move_sig_drop_direct_ref(expr, parent_expr);
+        }
+
+        if self.sig_drop_holder != SigDropHolder::None {
+            let parent_ty = self.cx.typeck_results().expr_ty(parent_expr);
+            if !ty_has_erased_regions(parent_ty) && !parent_expr.is_syntactic_place_expr() {
+                self.replace_current_sig_drop(parent_expr.span, parent_ty.is_unit(), 0);
+                self.sig_drop_holder = SigDropHolder::Moved;
+            }
+
+            let (peel_ref_ty, peel_ref_times) = ty_peel_refs(parent_ty);
+            if !ty_has_erased_regions(peel_ref_ty) && is_copy(self.cx, peel_ref_ty) {
+                self.replace_current_sig_drop(parent_expr.span, peel_ref_ty.is_unit(), peel_ref_times);
+                self.sig_drop_holder = SigDropHolder::Moved;
             }
-        } else if ty.is_trivially_pure_clone_copy() {
-            self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveOnly);
-        } else if allow_move_and_clone {
-            self.replace_current_sig_drop(expr.span, false, LintSuggestion::MoveAndClone);
         }
     }
 
-    fn move_current_suggestion(&mut self) {
-        if let Some(current) = self.current_sig_drop.take() {
-            self.sig_drop_spans.get_or_insert_with(Vec::new).push(current);
+    fn try_move_sig_drop_direct_ref(&mut self, expr: &'tcx Expr<'_>, parent_expr: &'tcx Expr<'_>) {
+        let arg_idx = match parent_expr.kind {
+            ExprKind::MethodCall(_, receiver, exprs, _) => std::iter::once(receiver)
+                .chain(exprs.iter())
+                .find_position(|ex| ex.hir_id == expr.hir_id)
+                .map(|(idx, _)| idx),
+            ExprKind::Call(_, exprs) => exprs
+                .iter()
+                .find_position(|ex| ex.hir_id == expr.hir_id)
+                .map(|(idx, _)| idx),
+            ExprKind::Binary(_, lhs, rhs) | ExprKind::AssignOp(_, lhs, rhs) => [lhs, rhs]
+                .iter()
+                .find_position(|ex| ex.hir_id == expr.hir_id)
+                .map(|(idx, _)| idx),
+            ExprKind::Unary(_, ex) => (ex.hir_id == expr.hir_id).then_some(0),
+            _ => {
+                // Here we assume that all other expressions create or propagate the reference to the value with
+                // significant drop.
+                self.sig_drop_holder = SigDropHolder::DirectRef;
+                return;
+            },
+        };
+        let Some(arg_idx) = arg_idx else {
+            return;
+        };
+
+        let fn_sig = if let Some(def_id) = self.cx.typeck_results().type_dependent_def_id(parent_expr.hir_id) {
+            self.cx.tcx.fn_sig(def_id).instantiate_identity()
+        } else {
+            return;
+        };
+
+        let input_re = if let Some(input_ty) = fn_sig.skip_binder().inputs().get(arg_idx)
+            && let rustc_middle::ty::Ref(input_re, _, _) = input_ty.kind()
+        {
+            input_re
+        } else {
+            return;
+        };
+
+        // Late bound lifetime parameters are not related to any constraints, so we can track them in a very
+        // simple manner. For other lifetime parameters, we give up and update the state to `PackedRef`.
+        let RegionKind::ReBound(_, input_re_bound) = input_re.kind() else {
+            self.sig_drop_holder = SigDropHolder::PackedRef;
+            return;
+        };
+        let contains_input_re = |re_bound| {
+            if re_bound == input_re_bound {
+                ControlFlow::Break(())
+            } else {
+                ControlFlow::Continue(())
+            }
+        };
+
+        let output_ty = fn_sig.skip_binder().output();
+        if let rustc_middle::ty::Ref(output_re, peel_ref_ty, _) = output_ty.kind()
+            && input_re == output_re
+            && for_each_top_level_late_bound_region(*peel_ref_ty, contains_input_re).is_continue()
+        {
+            // We're lucky! The output type is still a direct reference to the value with significant drop.
+            self.sig_drop_holder = SigDropHolder::DirectRef;
+        } else if for_each_top_level_late_bound_region(output_ty, contains_input_re).is_continue() {
+            // The lifetime to the value with significant drop goes away. So we can emit a lint that suggests to
+            // move the expression out.
+            self.replace_current_sig_drop(parent_expr.span, output_ty.is_unit(), 0);
+            self.sig_drop_holder = SigDropHolder::Moved;
+        } else {
+            // TODO: The lifetime is still there but it's for a inner type. For instance, consider
+            // `Some(&mutex.lock().field)`, which has a type of `Option<&u32>`. How to address this scenario?
+            self.sig_drop_holder = SigDropHolder::PackedRef;
         }
     }
+}
 
-    fn visit_exprs_for_binary_ops(
-        &mut self,
-        left: &'tcx Expr<'_>,
-        right: &'tcx Expr<'_>,
-        is_unit_return_val: bool,
-        span: Span,
-    ) {
-        self.special_handling_for_binary_op = true;
-        self.visit_expr(left);
-        self.visit_expr(right);
-
-        // If either side had a significant drop, suggest moving the entire scrutinee to avoid
-        // unnecessary copies and to simplify cases where both sides have significant drops.
-        if self.has_significant_drop {
-            self.replace_current_sig_drop(span, is_unit_return_val, LintSuggestion::MoveOnly);
-        }
+fn ty_peel_refs(mut ty: Ty<'_>) -> (Ty<'_>, usize) {
+    let mut n = 0;
+    while let rustc_middle::ty::Ref(_, new_ty, Mutability::Not) = ty.kind() {
+        ty = *new_ty;
+        n += 1;
+    }
+    (ty, n)
+}
+
+fn ty_has_erased_regions(ty: Ty<'_>) -> bool {
+    struct V;
 
-        self.special_handling_for_binary_op = false;
+    impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for V {
+        type Result = ControlFlow<()>;
+
+        fn visit_region(&mut self, region: Region<'tcx>) -> Self::Result {
+            if region.is_erased() {
+                ControlFlow::Break(())
+            } else {
+                ControlFlow::Continue(())
+            }
+        }
     }
+
+    ty.visit_with(&mut V).is_break()
 }
 
 impl<'a, 'tcx> Visitor<'tcx> for SigDropHelper<'a, 'tcx> {
     fn visit_expr(&mut self, ex: &'tcx Expr<'_>) {
-        if !self.is_chain_end && self.sig_drop_checker.is_sig_drop_expr(ex) {
-            self.has_significant_drop = true;
+        // We've emited a lint on some neighborhood expression. That lint will suggest to move out the
+        // _parent_ expression (not the expression itself). Since we decide to move out the parent
+        // expression, it is pointless to continue to process the current expression.
+        if self.sig_drop_holder == SigDropHolder::Moved {
             return;
         }
-        self.is_chain_end = false;
+
+        // These states are of neighborhood expressions. We save and clear them here, and we'll later merge
+        // the states of the current expression with them at the end of the method.
+        let sig_drop_holder_before = core::mem::take(&mut self.sig_drop_holder);
+        let sig_drop_spans_before = core::mem::take(&mut self.sig_drop_spans);
+        let parent_expr_before = self.parent_expr.replace(ex);
 
         match ex.kind {
-            ExprKind::MethodCall(_, expr, ..) => {
-                self.visit_expr(expr);
-            }
-            ExprKind::Binary(_, left, right) => {
-                self.visit_exprs_for_binary_ops(left, right, false, ex.span);
-            }
-            ExprKind::Assign(left, right, _) | ExprKind::AssignOp(_, left, right) => {
-                self.visit_exprs_for_binary_ops(left, right, true, ex.span);
-            }
-            ExprKind::Tup(exprs) => {
-                for expr in exprs {
-                    self.visit_expr(expr);
-                    if self.has_significant_drop {
-                        // We may have not have set current_sig_drop if all the suggestions were
-                        // MoveAndClone, so add this tuple item's full expression in that case.
-                        if self.current_sig_drop.is_none() {
-                            self.try_setting_current_suggestion(expr, true);
-                        }
-
-                        // Now we are guaranteed to have something, so add it to the final vec.
-                        self.move_current_suggestion();
-                    }
-                    // Reset `has_significant_drop` after each tuple expression so we can look for
-                    // additional cases.
-                    self.has_significant_drop = false;
-                }
-                if self.sig_drop_spans.is_some() {
-                    self.has_significant_drop = true;
-                }
-            }
-            ExprKind::Array(..) |
-            ExprKind::Call(..) |
-            ExprKind::Unary(..) |
-            ExprKind::If(..) |
-            ExprKind::Match(..) |
-            ExprKind::Field(..) |
-            ExprKind::Index(..) |
-            ExprKind::Ret(..) |
-            ExprKind::Become(..) |
-            ExprKind::Repeat(..) |
-            ExprKind::Yield(..) => walk_expr(self, ex),
-            ExprKind::AddrOf(_, _, _) |
-            ExprKind::Block(_, _) |
-            ExprKind::Break(_, _) |
-            ExprKind::Cast(_, _) |
-            // Don't want to check the closure itself, only invocation, which is covered by MethodCall
-            ExprKind::Closure { .. } |
-            ExprKind::ConstBlock(_) |
-            ExprKind::Continue(_) |
-            ExprKind::DropTemps(_) |
-            ExprKind::Err(_) |
-            ExprKind::InlineAsm(_) |
-            ExprKind::OffsetOf(_, _) |
-            ExprKind::Let(_) |
-            ExprKind::Lit(_) |
-            ExprKind::Loop(_, _, _, _) |
-            ExprKind::Path(_) |
-            ExprKind::Struct(_, _, _) |
-            ExprKind::Type(_, _) => {
-                return;
+            // Skip blocks because values in blocks will be dropped as usual.
+            ExprKind::Block(..) => (),
+            _ => walk_expr(self, ex),
+        }
+
+        if let Some(parent_ex) = parent_expr_before {
+            match parent_ex.kind {
+                ExprKind::Assign(lhs, _, _) | ExprKind::AssignOp(_, lhs, _)
+                    if lhs.hir_id == ex.hir_id && self.sig_drop_holder == SigDropHolder::Moved =>
+                {
+                    // Never move out only the assignee. Instead, we should always move out the whole assigment.
+                    self.replace_current_sig_drop(parent_ex.span, true, 0);
+                },
+                _ => {
+                    self.try_move_sig_drop(ex, parent_ex);
+                },
             }
         }
 
-        // Once a significant temporary has been found, we need to go back up at least 1 level to
-        // find the span to extract for replacement, so the temporary gets dropped. However, for
-        // binary ops, we want to move the whole scrutinee so we avoid unnecessary copies and to
-        // simplify cases where both sides have significant drops.
-        if self.has_significant_drop && !self.special_handling_for_binary_op {
-            self.try_setting_current_suggestion(ex, false);
+        self.sig_drop_holder = std::cmp::max(self.sig_drop_holder, sig_drop_holder_before);
+
+        // We do not need those old spans in neighborhood expressions if we emit a lint that suggests to
+        // move out the _parent_ expression (i.e., `self.sig_drop_holder == SigDropHolder::Moved`).
+        if self.sig_drop_holder != SigDropHolder::Moved {
+            let mut sig_drop_spans = sig_drop_spans_before;
+            sig_drop_spans.append(&mut self.sig_drop_spans);
+            self.sig_drop_spans = sig_drop_spans;
         }
+
+        self.parent_expr = parent_expr_before;
     }
 }
 
diff --git a/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs b/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs
index 6c9bdcff8262..f4397212cf66 100644
--- a/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs
+++ b/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs
@@ -1,8 +1,12 @@
+use std::iter::once;
+
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet;
 use clippy_utils::{get_expr_use_or_unification_node, is_res_lang_ctor, path_res, std_or_core};
 
 use rustc_errors::Applicability;
+use rustc_hir::def_id::DefId;
+use rustc_hir::hir_id::HirId;
 use rustc_hir::LangItem::{OptionNone, OptionSome};
 use rustc_hir::{Expr, ExprKind, Node};
 use rustc_lint::LateContext;
@@ -25,7 +29,29 @@ impl IterType {
     }
 }
 
-pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, method_name: &str, recv: &Expr<'_>) {
+fn is_arg_ty_unified_in_fn<'tcx>(
+    cx: &LateContext<'tcx>,
+    fn_id: DefId,
+    arg_id: HirId,
+    args: impl IntoIterator<Item = &'tcx Expr<'tcx>>,
+) -> bool {
+    let fn_sig = cx.tcx.fn_sig(fn_id).instantiate_identity();
+    let arg_id_in_args = args.into_iter().position(|e| e.hir_id == arg_id).unwrap();
+    let arg_ty_in_args = fn_sig.input(arg_id_in_args).skip_binder();
+
+    cx.tcx.predicates_of(fn_id).predicates.iter().any(|(clause, _)| {
+        clause
+            .as_projection_clause()
+            .and_then(|p| p.map_bound(|p| p.term.ty()).transpose())
+            .is_some_and(|ty| ty.skip_binder() == arg_ty_in_args)
+    }) || fn_sig
+        .inputs()
+        .iter()
+        .enumerate()
+        .any(|(i, ty)| i != arg_id_in_args && ty.skip_binder().walk().any(|arg| arg.as_type() == Some(arg_ty_in_args)))
+}
+
+pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>, method_name: &str, recv: &'tcx Expr<'tcx>) {
     let item = match recv.kind {
         ExprKind::Array([]) => None,
         ExprKind::Array([e]) => Some(e),
@@ -43,6 +69,25 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, method_name: &str, re
     let is_unified = match get_expr_use_or_unification_node(cx.tcx, expr) {
         Some((Node::Expr(parent), child_id)) => match parent.kind {
             ExprKind::If(e, _, _) | ExprKind::Match(e, _, _) if e.hir_id == child_id => false,
+            ExprKind::Call(
+                Expr {
+                    kind: ExprKind::Path(path),
+                    hir_id,
+                    ..
+                },
+                args,
+            ) => cx
+                .typeck_results()
+                .qpath_res(path, *hir_id)
+                .opt_def_id()
+                .filter(|fn_id| cx.tcx.def_kind(fn_id).is_fn_like())
+                .is_some_and(|fn_id| is_arg_ty_unified_in_fn(cx, fn_id, child_id, args)),
+            ExprKind::MethodCall(_name, recv, args, _span) => is_arg_ty_unified_in_fn(
+                cx,
+                cx.typeck_results().type_dependent_def_id(parent.hir_id).unwrap(),
+                child_id,
+                once(recv).chain(args.iter()),
+            ),
             ExprKind::If(_, _, _)
             | ExprKind::Match(_, _, _)
             | ExprKind::Closure(_)
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index 9d67aa233797..75a86c0c8344 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -257,7 +257,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `.unwrap()` or `.unwrap_err()` calls on `Result`s and `.unwrap()` call on `Option`s.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// It is better to handle the `None` or `Err` case,
     /// or at least call `.expect(_)` with a more helpful message. Still, for a lot of
     /// quick-and-dirty code, `unwrap` is a good choice, which is why this lint is
@@ -333,7 +333,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `.expect()` or `.expect_err()` calls on `Result`s and `.expect()` call on `Option`s.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Usually it is better to handle the `None` or `Err` case.
     /// Still, for a lot of quick-and-dirty code, `expect` is a good choice, which is why
     /// this lint is `Allow` by default.
@@ -1029,8 +1029,8 @@ declare_clippy_lint! {
     /// (`Rc`, `Arc`, `rc::Weak`, or `sync::Weak`), and suggests calling Clone via unified
     /// function syntax instead (e.g., `Rc::clone(foo)`).
     ///
-    /// ### Why is this bad?
-    /// Calling '.clone()' on an Rc, Arc, or Weak
+    /// ### Why restrict this?
+    /// Calling `.clone()` on an `Rc`, `Arc`, or `Weak`
     /// can obscure the fact that only the pointer is being cloned, not the underlying
     /// data.
     ///
@@ -1051,7 +1051,7 @@ declare_clippy_lint! {
     #[clippy::version = "pre 1.29.0"]
     pub CLONE_ON_REF_PTR,
     restriction,
-    "using 'clone' on a ref-counted pointer"
+    "using `clone` on a ref-counted pointer"
 }
 
 declare_clippy_lint! {
@@ -1359,7 +1359,7 @@ declare_clippy_lint! {
     /// Checks for usage of `.get().unwrap()` (or
     /// `.get_mut().unwrap`) on a standard library type which implements `Index`
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Using the Index trait (`[]`) is more clear and more
     /// concise.
     ///
@@ -1743,7 +1743,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `FileType::is_file()`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// When people testing a file type with `FileType::is_file`
     /// they are testing whether a path is something they can get bytes from. But
     /// `is_file` doesn't cover special file types in unix-like systems, and doesn't cover
@@ -2688,8 +2688,9 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for instances of `map_err(|_| Some::Enum)`
     ///
-    /// ### Why is this bad?
-    /// This `map_err` throws away the original error rather than allowing the enum to contain and report the cause of the error
+    /// ### Why restrict this?
+    /// This `map_err` throws away the original error rather than allowing the enum to
+    /// contain and report the cause of the error.
     ///
     /// ### Example
     /// Before:
@@ -3145,7 +3146,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of File::read_to_end and File::read_to_string.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// `fs::{read, read_to_string}` provide the same functionality when `buf` is empty with fewer imports and no intermediate values.
     /// See also: [fs::read docs](https://doc.rust-lang.org/std/fs/fn.read.html), [fs::read_to_string docs](https://doc.rust-lang.org/std/fs/fn.read_to_string.html)
     ///
diff --git a/clippy_lints/src/methods/unnecessary_iter_cloned.rs b/clippy_lints/src/methods/unnecessary_iter_cloned.rs
index 7431dc1cf0b1..d1300dd43c28 100644
--- a/clippy_lints/src/methods/unnecessary_iter_cloned.rs
+++ b/clippy_lints/src/methods/unnecessary_iter_cloned.rs
@@ -38,7 +38,7 @@ pub fn check_for_loop_iter(
 ) -> bool {
     if let Some(grandparent) = get_parent_expr(cx, expr).and_then(|parent| get_parent_expr(cx, parent))
         && let Some(ForLoop { pat, body, .. }) = ForLoop::hir(grandparent)
-        && let (clone_or_copy_needed, addr_of_exprs) = clone_or_copy_needed(cx, pat, body)
+        && let (clone_or_copy_needed, references_to_binding) = clone_or_copy_needed(cx, pat, body)
         && !clone_or_copy_needed
         && let Some(receiver_snippet) = snippet_opt(cx, receiver.span)
     {
@@ -123,14 +123,12 @@ pub fn check_for_loop_iter(
                     Applicability::MachineApplicable
                 };
                 diag.span_suggestion(expr.span, "use", snippet, applicability);
-                for addr_of_expr in addr_of_exprs {
-                    match addr_of_expr.kind {
-                        ExprKind::AddrOf(_, _, referent) => {
-                            let span = addr_of_expr.span.with_hi(referent.span.lo());
-                            diag.span_suggestion(span, "remove this `&`", "", applicability);
-                        },
-                        _ => unreachable!(),
-                    }
+                if !references_to_binding.is_empty() {
+                    diag.multipart_suggestion(
+                        "remove any references to the binding",
+                        references_to_binding,
+                        applicability,
+                    );
                 }
             },
         );
diff --git a/clippy_lints/src/methods/utils.rs b/clippy_lints/src/methods/utils.rs
index 34d7b9acbe4b..1a55b7160fb1 100644
--- a/clippy_lints/src/methods/utils.rs
+++ b/clippy_lints/src/methods/utils.rs
@@ -9,6 +9,7 @@ use rustc_lint::LateContext;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::sym;
+use rustc_span::Span;
 
 pub(super) fn derefs_to_slice<'tcx>(
     cx: &LateContext<'tcx>,
@@ -96,15 +97,15 @@ pub(super) fn clone_or_copy_needed<'tcx>(
     cx: &LateContext<'tcx>,
     pat: &Pat<'tcx>,
     body: &'tcx Expr<'tcx>,
-) -> (bool, Vec<&'tcx Expr<'tcx>>) {
+) -> (bool, Vec<(Span, String)>) {
     let mut visitor = CloneOrCopyVisitor {
         cx,
         binding_hir_ids: pat_bindings(pat),
         clone_or_copy_needed: false,
-        addr_of_exprs: Vec::new(),
+        references_to_binding: Vec::new(),
     };
     visitor.visit_expr(body);
-    (visitor.clone_or_copy_needed, visitor.addr_of_exprs)
+    (visitor.clone_or_copy_needed, visitor.references_to_binding)
 }
 
 /// Returns a vector of all `HirId`s bound by the pattern.
@@ -127,7 +128,7 @@ struct CloneOrCopyVisitor<'cx, 'tcx> {
     cx: &'cx LateContext<'tcx>,
     binding_hir_ids: Vec<HirId>,
     clone_or_copy_needed: bool,
-    addr_of_exprs: Vec<&'tcx Expr<'tcx>>,
+    references_to_binding: Vec<(Span, String)>,
 }
 
 impl<'cx, 'tcx> Visitor<'tcx> for CloneOrCopyVisitor<'cx, 'tcx> {
@@ -142,8 +143,11 @@ impl<'cx, 'tcx> Visitor<'tcx> for CloneOrCopyVisitor<'cx, 'tcx> {
         if self.is_binding(expr) {
             if let Some(parent) = get_parent_expr(self.cx, expr) {
                 match parent.kind {
-                    ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, _) => {
-                        self.addr_of_exprs.push(parent);
+                    ExprKind::AddrOf(BorrowKind::Ref, Mutability::Not, referent) => {
+                        if !parent.span.from_expansion() {
+                            self.references_to_binding
+                                .push((parent.span.until(referent.span), String::new()));
+                        }
                         return;
                     },
                     ExprKind::MethodCall(.., args, _) => {
diff --git a/clippy_lints/src/min_ident_chars.rs b/clippy_lints/src/min_ident_chars.rs
index c6b7f5b0ce27..e43b712021ae 100644
--- a/clippy_lints/src/min_ident_chars.rs
+++ b/clippy_lints/src/min_ident_chars.rs
@@ -12,14 +12,13 @@ use std::borrow::Cow;
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for idents which comprise of a single letter.
+    /// Checks for identifiers which consist of a single character (or fewer than the configured threshold).
     ///
     /// Note: This lint can be very noisy when enabled; it may be desirable to only enable it
     /// temporarily.
     ///
-    /// ### Why is this bad?
-    /// In many cases it's not, but at times it can severely hinder readability. Some codebases may
-    /// wish to disallow this to improve readability.
+    /// ### Why restrict this?
+    /// To improve readability by requiring that every variable has a name more specific than a single letter can be.
     ///
     /// ### Example
     /// ```rust,ignore
diff --git a/clippy_lints/src/misc_early/mod.rs b/clippy_lints/src/misc_early/mod.rs
index 2f5499d7656f..fedcfd11fdcc 100644
--- a/clippy_lints/src/misc_early/mod.rs
+++ b/clippy_lints/src/misc_early/mod.rs
@@ -23,7 +23,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for structure field patterns bound to wildcards.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Using `..` instead is shorter and leaves the focus on
     /// the fields that are actually bound.
     ///
@@ -138,7 +138,7 @@ declare_clippy_lint! {
     /// To enforce unseparated literal suffix style,
     /// see the `separated_literal_suffix` lint.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Suffix style should be consistent.
     ///
     /// ### Example
@@ -166,7 +166,7 @@ declare_clippy_lint! {
     /// To enforce separated literal suffix style,
     /// see the `unseparated_literal_suffix` lint.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Suffix style should be consistent.
     ///
     /// ### Example
diff --git a/clippy_lints/src/missing_assert_message.rs b/clippy_lints/src/missing_assert_message.rs
index 04df7b7a7e5a..dd98352da860 100644
--- a/clippy_lints/src/missing_assert_message.rs
+++ b/clippy_lints/src/missing_assert_message.rs
@@ -10,7 +10,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks assertions without a custom panic message.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Without a good custom message, it'd be hard to understand what went wrong when the assertion fails.
     /// A good custom message should be more about why the failure of the assertion is problematic
     /// and not what is failed because the assertion already conveys that.
diff --git a/clippy_lints/src/missing_asserts_for_indexing.rs b/clippy_lints/src/missing_asserts_for_indexing.rs
index c29e46b941c6..752723a0c68e 100644
--- a/clippy_lints/src/missing_asserts_for_indexing.rs
+++ b/clippy_lints/src/missing_asserts_for_indexing.rs
@@ -21,7 +21,7 @@ declare_clippy_lint! {
     /// Checks for repeated slice indexing without asserting beforehand that the length
     /// is greater than the largest index used to index into the slice.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// In the general case where the compiler does not have a lot of information
     /// about the length of a slice, indexing it repeatedly will generate a bounds check
     /// for every single index.
diff --git a/clippy_lints/src/missing_doc.rs b/clippy_lints/src/missing_doc.rs
index 2fb784dae1cd..ca344dc5c810 100644
--- a/clippy_lints/src/missing_doc.rs
+++ b/clippy_lints/src/missing_doc.rs
@@ -20,9 +20,9 @@ use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Warns if there is missing doc for any private documentable item
+    /// Warns if there is missing documentation for any private documentable item.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Doc is good. *rustc* has a `MISSING_DOCS`
     /// allowed-by-default lint for
     /// public members, but has no way to enforce documentation of private items.
diff --git a/clippy_lints/src/missing_inline.rs b/clippy_lints/src/missing_inline.rs
index c6a76478806a..33a14d8b7fed 100644
--- a/clippy_lints/src/missing_inline.rs
+++ b/clippy_lints/src/missing_inline.rs
@@ -10,13 +10,16 @@ declare_clippy_lint! {
     /// It lints if an exported function, method, trait method with default impl,
     /// or trait method impl is not `#[inline]`.
     ///
-    /// ### Why is this bad?
-    /// In general, it is not. Functions can be inlined across
-    /// crates when that's profitable as long as any form of LTO is used. When LTO is disabled,
-    /// functions that are not `#[inline]` cannot be inlined across crates. Certain types of crates
-    /// might intend for most of the methods in their public API to be able to be inlined across
-    /// crates even when LTO is disabled. For these types of crates, enabling this lint might make
-    /// sense. It allows the crate to require all exported methods to be `#[inline]` by default, and
+    /// ### Why restrict this?
+    /// When a function is not marked `#[inline]`, it is not
+    /// [a “small” candidate for automatic inlining][small], and LTO is not in use, then it is not
+    /// possible for the function to be inlined into the code of any crate other than the one in
+    /// which it is defined.  Depending on the role of the function and the relationship of the crates,
+    /// this could significantly reduce performance.
+    ///
+    /// Certain types of crates might intend for most of the methods in their public API to be able
+    /// to be inlined across crates even when LTO is disabled.
+    /// This lint allows those crates to require all exported methods to be `#[inline]` by default, and
     /// then opt out for specific methods where this might not make sense.
     ///
     /// ### Example
@@ -51,6 +54,8 @@ declare_clippy_lint! {
     ///    fn def_bar() {} // missing #[inline]
     /// }
     /// ```
+    ///
+    /// [small]: https://github.com/rust-lang/rust/pull/116505
     #[clippy::version = "pre 1.29.0"]
     pub MISSING_INLINE_IN_PUBLIC_ITEMS,
     restriction,
diff --git a/clippy_lints/src/missing_trait_methods.rs b/clippy_lints/src/missing_trait_methods.rs
index 6f844bc646a2..85029a5e6a0d 100644
--- a/clippy_lints/src/missing_trait_methods.rs
+++ b/clippy_lints/src/missing_trait_methods.rs
@@ -10,16 +10,16 @@ use rustc_session::declare_lint_pass;
 declare_clippy_lint! {
     /// ### What it does
     /// Checks if a provided method is used implicitly by a trait
-    /// implementation. A usage example would be a wrapper where every method
-    /// should perform some operation before delegating to the inner type's
     /// implementation.
     ///
+    /// ### Why restrict this?
+    /// To ensure that a certain implementation implements every method; for example,
+    /// a wrapper type where every method should delegate to the corresponding method of
+    /// the inner type's implementation.
+    ///
     /// This lint should typically be enabled on a specific trait `impl` item
     /// rather than globally.
     ///
-    /// ### Why is this bad?
-    /// Indicates that a method is missing.
-    ///
     /// ### Example
     /// ```no_run
     /// trait Trait {
diff --git a/clippy_lints/src/mixed_read_write_in_expression.rs b/clippy_lints/src/mixed_read_write_in_expression.rs
index 181351910db6..9c5a8a0cfcdf 100644
--- a/clippy_lints/src/mixed_read_write_in_expression.rs
+++ b/clippy_lints/src/mixed_read_write_in_expression.rs
@@ -12,9 +12,10 @@ declare_clippy_lint! {
     /// whether the read occurs before or after the write depends on the evaluation
     /// order of sub-expressions.
     ///
-    /// ### Why is this bad?
-    /// It is often confusing to read. As described [here](https://doc.rust-lang.org/reference/expressions.html?highlight=subexpression#evaluation-order-of-operands),
-    /// the operands of these expressions are evaluated before applying the effects of the expression.
+    /// ### Why restrict this?
+    /// While [the evaluation order of sub-expressions] is fully specified in Rust,
+    /// it still may be confusing to read an expression where the evaluation order
+    /// affects its behavior.
     ///
     /// ### Known problems
     /// Code which intentionally depends on the evaluation
@@ -40,6 +41,8 @@ declare_clippy_lint! {
     /// };
     /// let a = tmp + x;
     /// ```
+    ///
+    /// [order]: (https://doc.rust-lang.org/reference/expressions.html?highlight=subexpression#evaluation-order-of-operands)
     #[clippy::version = "pre 1.29.0"]
     pub MIXED_READ_WRITE_IN_EXPRESSION,
     restriction,
diff --git a/clippy_lints/src/module_style.rs b/clippy_lints/src/module_style.rs
index 6c031c081750..305499f9da43 100644
--- a/clippy_lints/src/module_style.rs
+++ b/clippy_lints/src/module_style.rs
@@ -10,9 +10,9 @@ use std::path::{Component, Path};
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks that module layout uses only self named module files, bans `mod.rs` files.
+    /// Checks that module layout uses only self named module files; bans `mod.rs` files.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Having multiple module layout styles in a project can be confusing.
     ///
     /// ### Example
@@ -41,7 +41,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks that module layout uses only `mod.rs` files.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Having multiple module layout styles in a project can be confusing.
     ///
     /// ### Example
diff --git a/clippy_lints/src/multiple_unsafe_ops_per_block.rs b/clippy_lints/src/multiple_unsafe_ops_per_block.rs
index 5306205aed7e..5b4ef852f0d9 100644
--- a/clippy_lints/src/multiple_unsafe_ops_per_block.rs
+++ b/clippy_lints/src/multiple_unsafe_ops_per_block.rs
@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::visitors::{for_each_expr_with_closures, Descend, Visitable};
 use core::ops::ControlFlow::Continue;
 use hir::def::{DefKind, Res};
-use hir::{BlockCheckMode, ExprKind, Safety, QPath, UnOp};
+use hir::{BlockCheckMode, ExprKind, QPath, Safety, UnOp};
 use rustc_ast::Mutability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
@@ -15,7 +15,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `unsafe` blocks that contain more than one unsafe operation.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Combined with `undocumented_unsafe_blocks`,
     /// this lint ensures that each unsafe operation must be independently justified.
     /// Combined with `unused_unsafe`, this lint also ensures
diff --git a/clippy_lints/src/mutex_atomic.rs b/clippy_lints/src/mutex_atomic.rs
index 7ecc86176942..853e476a006c 100644
--- a/clippy_lints/src/mutex_atomic.rs
+++ b/clippy_lints/src/mutex_atomic.rs
@@ -14,7 +14,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `Mutex<X>` where an atomic will do.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Using a mutex just to make access to a plain bool or
     /// reference sequential is shooting flies with cannons.
     /// `std::sync::atomic::AtomicBool` and `std::sync::atomic::AtomicPtr` are leaner and
diff --git a/clippy_lints/src/needless_bool.rs b/clippy_lints/src/needless_bool.rs
index f9ee4a3dc93a..e1866eaa18a7 100644
--- a/clippy_lints/src/needless_bool.rs
+++ b/clippy_lints/src/needless_bool.rs
@@ -6,8 +6,8 @@ use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{
-    higher, is_else_clause, is_expn_of, is_parent_stmt, peel_blocks, peel_blocks_with_stmt, span_extract_comment,
-    SpanlessEq,
+    higher, is_block_like, is_else_clause, is_expn_of, is_parent_stmt, peel_blocks, peel_blocks_with_stmt,
+    span_extract_comment, SpanlessEq,
 };
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
@@ -121,14 +121,7 @@ fn condition_needs_parentheses(e: &Expr<'_>) -> bool {
     | ExprKind::Type(i, _)
     | ExprKind::Index(i, _, _) = inner.kind
     {
-        if matches!(
-            i.kind,
-            ExprKind::Block(..)
-                | ExprKind::ConstBlock(..)
-                | ExprKind::If(..)
-                | ExprKind::Loop(..)
-                | ExprKind::Match(..)
-        ) {
+        if is_block_like(i) {
             return true;
         }
         inner = i;
diff --git a/clippy_lints/src/non_expressive_names.rs b/clippy_lints/src/non_expressive_names.rs
index 7b26235291a5..eacfe9ff328d 100644
--- a/clippy_lints/src/non_expressive_names.rs
+++ b/clippy_lints/src/non_expressive_names.rs
@@ -98,6 +98,10 @@ struct SimilarNamesLocalVisitor<'a, 'tcx> {
 
 impl<'a, 'tcx> SimilarNamesLocalVisitor<'a, 'tcx> {
     fn check_single_char_names(&self) {
+        if self.single_char_names.last().map(Vec::len) == Some(0) {
+            return;
+        }
+
         let num_single_char_names = self.single_char_names.iter().flatten().count();
         let threshold = self.lint.single_char_binding_names_threshold;
         if num_single_char_names as u64 > threshold {
diff --git a/clippy_lints/src/operators/mod.rs b/clippy_lints/src/operators/mod.rs
index e002429e3a47..0948973df5a3 100644
--- a/clippy_lints/src/operators/mod.rs
+++ b/clippy_lints/src/operators/mod.rs
@@ -70,7 +70,7 @@ declare_clippy_lint! {
     /// Known safe built-in types like `Wrapping` or `Saturating`, floats, operations in constant
     /// environments, allowed types and non-constant operations that won't overflow are ignored.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// For integers, overflow will trigger a panic in debug builds or wrap the result in
     /// release mode; division by zero will cause a panic in either mode. As a result, it is
     /// desirable to explicitly call checked, wrapping or saturating arithmetic methods.
@@ -100,7 +100,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for float arithmetic.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// For some embedded systems or kernel development, it
     /// can be useful to rule out floating-point numbers.
     ///
@@ -502,7 +502,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for division of integers
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// When outside of some very specific algorithms,
     /// integer division is very often a mistake because it discards the
     /// remainder.
@@ -596,7 +596,7 @@ declare_clippy_lint! {
     /// value and constant, except in functions called `*eq*` (which probably
     /// implement equality for a type involving floats).
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Floating point calculations are usually imprecise, so
     /// asking if two values are *exactly* equal is asking for trouble. For a good
     /// guide on what to do, see [the floating point
@@ -653,8 +653,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for modulo arithmetic.
     ///
-    /// ### Why is this bad?
-    /// The results of modulo (%) operation might differ
+    /// ### Why restrict this?
+    /// The results of modulo (`%`) operation might differ
     /// depending on the language, when negative numbers are involved.
     /// If you interop with different languages it might be beneficial
     /// to double check all places that use modulo arithmetic.
diff --git a/clippy_lints/src/panic_in_result_fn.rs b/clippy_lints/src/panic_in_result_fn.rs
index f821a4efee7b..806638c0505b 100644
--- a/clippy_lints/src/panic_in_result_fn.rs
+++ b/clippy_lints/src/panic_in_result_fn.rs
@@ -13,9 +13,9 @@ use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for usage of `panic!` or assertions in a function of type result.
+    /// Checks for usage of `panic!` or assertions in a function whose return type is `Result`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// For some codebases, it is desirable for functions of type result to return an error instead of crashing. Hence panicking macros should be avoided.
     ///
     /// ### Known problems
diff --git a/clippy_lints/src/panic_unimplemented.rs b/clippy_lints/src/panic_unimplemented.rs
index 75066c1f0d2e..80ef761906e0 100644
--- a/clippy_lints/src/panic_unimplemented.rs
+++ b/clippy_lints/src/panic_unimplemented.rs
@@ -14,8 +14,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `panic!`.
     ///
-    /// ### Why is this bad?
-    /// `panic!` will stop the execution of the executable.
+    /// ### Why restrict this?
+    /// This macro, or panics in general, may be unwanted in production code.
     ///
     /// ### Example
     /// ```no_run
@@ -31,8 +31,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `unimplemented!`.
     ///
-    /// ### Why is this bad?
-    /// This macro should not be present in production code.
+    /// ### Why restrict this?
+    /// This macro, or panics in general, may be unwanted in production code.
     ///
     /// ### Example
     /// ```no_run
@@ -48,9 +48,9 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `todo!`.
     ///
-    /// ### Why is this bad?
-    /// The `todo!` macro is often used for unfinished code, and it causes
-    /// code to panic. It should not be present in production code.
+    /// ### Why restrict this?
+    /// The `todo!` macro indicates the presence of unfinished code,
+    /// so it should not be present in production code.
     ///
     /// ### Example
     /// ```no_run
@@ -70,8 +70,8 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `unreachable!`.
     ///
-    /// ### Why is this bad?
-    /// This macro can cause code to panic.
+    /// ### Why restrict this?
+    /// This macro, or panics in general, may be unwanted in production code.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/partial_pub_fields.rs b/clippy_lints/src/partial_pub_fields.rs
index ffa403e27ca3..2d20cbea698f 100644
--- a/clippy_lints/src/partial_pub_fields.rs
+++ b/clippy_lints/src/partial_pub_fields.rs
@@ -5,15 +5,16 @@ use rustc_session::declare_lint_pass;
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks whether partial fields of a struct are public.
+    /// Checks whether some but not all fields of a `struct` are public.
     ///
     /// Either make all fields of a type public, or make none of them public
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Most types should either be:
     /// * Abstract data types: complex objects with opaque implementation which guard
-    /// interior invariants and expose intentionally limited API to the outside world.
-    /// * Data: relatively simple objects which group a bunch of related attributes together.
+    ///   interior invariants and expose intentionally limited API to the outside world.
+    /// * Data: relatively simple objects which group a bunch of related attributes together,
+    ///   but have no invariants.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/pattern_type_mismatch.rs b/clippy_lints/src/pattern_type_mismatch.rs
index 44db061b8bee..9661a57b8b95 100644
--- a/clippy_lints/src/pattern_type_mismatch.rs
+++ b/clippy_lints/src/pattern_type_mismatch.rs
@@ -30,9 +30,8 @@ declare_clippy_lint! {
     /// this lint can still be used to highlight areas of interest and ensure a good understanding
     /// of ownership semantics.
     ///
-    /// ### Why is this bad?
-    /// It isn't bad in general. But in some contexts it can be desirable
-    /// because it increases ownership hints in the code, and will guard against some changes
+    /// ### Why restrict this?
+    /// It increases ownership hints in the code, and will guard against some changes
     /// in ownership.
     ///
     /// ### Example
diff --git a/clippy_lints/src/pub_use.rs b/clippy_lints/src/pub_use.rs
index c0e999e76ef2..ab8f8a1689dc 100644
--- a/clippy_lints/src/pub_use.rs
+++ b/clippy_lints/src/pub_use.rs
@@ -5,13 +5,11 @@ use rustc_session::declare_lint_pass;
 
 declare_clippy_lint! {
     /// ### What it does
-    ///
     /// Restricts the usage of `pub use ...`
     ///
-    /// ### Why is this bad?
-    ///
-    /// `pub use` is usually fine, but a project may wish to limit `pub use` instances to prevent
-    /// unintentional exports or to encourage placing exported items directly in public modules
+    /// ### Why restrict this?
+    /// A project may wish to limit `pub use` instances to prevent
+    /// unintentional exports, or to encourage placing exported items directly in public modules.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/question_mark_used.rs b/clippy_lints/src/question_mark_used.rs
index ddfc53083c46..f5e6cb804da1 100644
--- a/clippy_lints/src/question_mark_used.rs
+++ b/clippy_lints/src/question_mark_used.rs
@@ -9,7 +9,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for expressions that use the question mark operator and rejects them.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Sometimes code wants to avoid the question mark operator because for instance a local
     /// block requires a macro to re-throw errors to attach additional information to the
     /// error.
diff --git a/clippy_lints/src/raw_strings.rs b/clippy_lints/src/raw_strings.rs
index 7e71f48c6d9a..3a0042454592 100644
--- a/clippy_lints/src/raw_strings.rs
+++ b/clippy_lints/src/raw_strings.rs
@@ -15,8 +15,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for raw string literals where a string literal can be used instead.
     ///
-    /// ### Why is this bad?
-    /// It's just unnecessary, but there are many cases where using a raw string literal is more
+    /// ### Why restrict this?
+    /// For consistent style by using simpler string literals whenever possible.
+    ///
+    /// However, there are many cases where using a raw string literal is more
     /// idiomatic than a string literal, so it's opt-in.
     ///
     /// ### Example
diff --git a/clippy_lints/src/redundant_slicing.rs b/clippy_lints/src/redundant_slicing.rs
index c99b657c23a2..7f87d18e5023 100644
--- a/clippy_lints/src/redundant_slicing.rs
+++ b/clippy_lints/src/redundant_slicing.rs
@@ -46,7 +46,7 @@ declare_clippy_lint! {
     /// Checks for slicing expressions which are equivalent to dereferencing the
     /// value.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Some people may prefer to dereference rather than slice.
     ///
     /// ### Example
diff --git a/clippy_lints/src/redundant_type_annotations.rs b/clippy_lints/src/redundant_type_annotations.rs
index 11b95ee3a54c..81556f396141 100644
--- a/clippy_lints/src/redundant_type_annotations.rs
+++ b/clippy_lints/src/redundant_type_annotations.rs
@@ -11,7 +11,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Warns about needless / redundant type annotations.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Code without type annotations is shorter and in most cases
     /// more idiomatic and easier to modify.
     ///
diff --git a/clippy_lints/src/ref_patterns.rs b/clippy_lints/src/ref_patterns.rs
index 607a0740b843..467038523b49 100644
--- a/clippy_lints/src/ref_patterns.rs
+++ b/clippy_lints/src/ref_patterns.rs
@@ -6,9 +6,11 @@ use rustc_session::declare_lint_pass;
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for usages of the `ref` keyword.
-    /// ### Why is this bad?
+    ///
+    /// ### Why restrict this?
     /// The `ref` keyword can be confusing for people unfamiliar with it, and often
     /// it is more concise to use `&` instead.
+    ///
     /// ### Example
     /// ```no_run
     /// let opt = Some(5);
diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs
index e8f9d4381047..48d6fb3c0378 100644
--- a/clippy_lints/src/returns.rs
+++ b/clippy_lints/src/returns.rs
@@ -3,8 +3,8 @@ use clippy_utils::source::{snippet_opt, snippet_with_context};
 use clippy_utils::sugg::has_enclosing_paren;
 use clippy_utils::visitors::{for_each_expr_with_closures, Descend};
 use clippy_utils::{
-    fn_def_id, is_from_proc_macro, is_inside_let_else, is_res_lang_ctor, path_res, path_to_local_id, span_contains_cfg,
-    span_find_starting_semi,
+    binary_expr_needs_parentheses, fn_def_id, is_from_proc_macro, is_inside_let_else, is_res_lang_ctor, path_res,
+    path_to_local_id, span_contains_cfg, span_find_starting_semi,
 };
 use core::ops::ControlFlow;
 use rustc_errors::Applicability;
@@ -129,7 +129,7 @@ enum RetReplacement<'tcx> {
     Empty,
     Block,
     Unit,
-    IfSequence(Cow<'tcx, str>, Applicability),
+    NeedsPar(Cow<'tcx, str>, Applicability),
     Expr(Cow<'tcx, str>, Applicability),
 }
 
@@ -139,13 +139,13 @@ impl<'tcx> RetReplacement<'tcx> {
             Self::Empty | Self::Expr(..) => "remove `return`",
             Self::Block => "replace `return` with an empty block",
             Self::Unit => "replace `return` with a unit value",
-            Self::IfSequence(..) => "remove `return` and wrap the sequence with parentheses",
+            Self::NeedsPar(..) => "remove `return` and wrap the sequence with parentheses",
         }
     }
 
     fn applicability(&self) -> Applicability {
         match self {
-            Self::Expr(_, ap) | Self::IfSequence(_, ap) => *ap,
+            Self::Expr(_, ap) | Self::NeedsPar(_, ap) => *ap,
             _ => Applicability::MachineApplicable,
         }
     }
@@ -157,7 +157,7 @@ impl<'tcx> Display for RetReplacement<'tcx> {
             Self::Empty => write!(f, ""),
             Self::Block => write!(f, "{{}}"),
             Self::Unit => write!(f, "()"),
-            Self::IfSequence(inner, _) => write!(f, "({inner})"),
+            Self::NeedsPar(inner, _) => write!(f, "({inner})"),
             Self::Expr(inner, _) => write!(f, "{inner}"),
         }
     }
@@ -244,7 +244,11 @@ impl<'tcx> LateLintPass<'tcx> for Return {
                     err.span_label(local.span, "unnecessary `let` binding");
 
                     if let Some(mut snippet) = snippet_opt(cx, initexpr.span) {
-                        if !cx.typeck_results().expr_adjustments(retexpr).is_empty() {
+                        if binary_expr_needs_parentheses(initexpr) {
+                            if !has_enclosing_paren(&snippet) {
+                                snippet = format!("({snippet})");
+                            }
+                        } else if !cx.typeck_results().expr_adjustments(retexpr).is_empty() {
                             if !has_enclosing_paren(&snippet) {
                                 snippet = format!("({snippet})");
                             }
@@ -349,8 +353,8 @@ fn check_final_expr<'tcx>(
 
                 let mut applicability = Applicability::MachineApplicable;
                 let (snippet, _) = snippet_with_context(cx, inner_expr.span, ret_span.ctxt(), "..", &mut applicability);
-                if expr_contains_conjunctive_ifs(inner_expr) {
-                    RetReplacement::IfSequence(snippet, applicability)
+                if binary_expr_needs_parentheses(inner_expr) {
+                    RetReplacement::NeedsPar(snippet, applicability)
                 } else {
                     RetReplacement::Expr(snippet, applicability)
                 }
@@ -404,18 +408,6 @@ fn check_final_expr<'tcx>(
     }
 }
 
-fn expr_contains_conjunctive_ifs<'tcx>(expr: &'tcx Expr<'tcx>) -> bool {
-    fn contains_if(expr: &Expr<'_>, on_if: bool) -> bool {
-        match expr.kind {
-            ExprKind::If(..) => on_if,
-            ExprKind::Binary(_, left, right) => contains_if(left, true) || contains_if(right, true),
-            _ => false,
-        }
-    }
-
-    contains_if(expr, false)
-}
-
 fn emit_return_lint(
     cx: &LateContext<'_>,
     ret_span: Span,
diff --git a/clippy_lints/src/same_name_method.rs b/clippy_lints/src/same_name_method.rs
index 7e27f70bcf94..8fdd19c549f5 100644
--- a/clippy_lints/src/same_name_method.rs
+++ b/clippy_lints/src/same_name_method.rs
@@ -14,7 +14,7 @@ declare_clippy_lint! {
     /// It lints if a struct has two methods with the same name:
     /// one from a trait, another not from trait.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Confusing.
     ///
     /// ### Example
diff --git a/clippy_lints/src/semicolon_block.rs b/clippy_lints/src/semicolon_block.rs
index 0b3adfb7a4b8..0e77acdfd77f 100644
--- a/clippy_lints/src/semicolon_block.rs
+++ b/clippy_lints/src/semicolon_block.rs
@@ -11,8 +11,7 @@ declare_clippy_lint! {
     /// Suggests moving the semicolon after a block to the inside of the block, after its last
     /// expression.
     ///
-    /// ### Why is this bad?
-    ///
+    /// ### Why restrict this?
     /// For consistency it's best to have the semicolon inside/outside the block. Either way is fine
     /// and this lint suggests inside the block.
     /// Take a look at `semicolon_outside_block` for the other alternative.
@@ -40,8 +39,7 @@ declare_clippy_lint! {
     ///
     /// Suggests moving the semicolon from a block's final expression outside of the block.
     ///
-    /// ### Why is this bad?
-    ///
+    /// ### Why restrict this?
     /// For consistency it's best to have the semicolon inside/outside the block. Either way is fine
     /// and this lint suggests outside the block.
     /// Take a look at `semicolon_inside_block` for the other alternative.
diff --git a/clippy_lints/src/shadow.rs b/clippy_lints/src/shadow.rs
index 9db08acb03b2..80f5fd0b4944 100644
--- a/clippy_lints/src/shadow.rs
+++ b/clippy_lints/src/shadow.rs
@@ -15,10 +15,10 @@ declare_clippy_lint! {
     /// Checks for bindings that shadow other bindings already in
     /// scope, while just changing reference level or mutability.
     ///
-    /// ### Why is this bad?
-    /// Not much, in fact it's a very common pattern in Rust
-    /// code. Still, some may opt to avoid it in their code base, they can set this
-    /// lint to `Warn`.
+    /// ### Why restrict this?
+    /// To require that what are formally distinct variables be given distinct names.
+    ///
+    /// See also `shadow_reuse` and `shadow_unrelated` for other restrictions on shadowing.
     ///
     /// ### Example
     /// ```no_run
@@ -42,12 +42,13 @@ declare_clippy_lint! {
     /// Checks for bindings that shadow other bindings already in
     /// scope, while reusing the original value.
     ///
-    /// ### Why is this bad?
-    /// Not too much, in fact it's a common pattern in Rust
-    /// code. Still, some argue that name shadowing like this hurts readability,
+    /// ### Why restrict this?
+    /// Some argue that name shadowing like this hurts readability,
     /// because a value may be bound to different things depending on position in
     /// the code.
     ///
+    /// See also `shadow_same` and `shadow_unrelated` for other restrictions on shadowing.
+    ///
     /// ### Example
     /// ```no_run
     /// let x = 2;
@@ -70,11 +71,14 @@ declare_clippy_lint! {
     /// scope, either without an initialization or with one that does not even use
     /// the original value.
     ///
-    /// ### Why is this bad?
-    /// Name shadowing can hurt readability, especially in
+    /// ### Why restrict this?
+    /// Shadowing a binding with a closely related one is part of idiomatic Rust,
+    /// but shadowing a binding by accident with an unrelated one may indicate a mistake.
+    ///
+    /// Additionally, name shadowing in general can hurt readability, especially in
     /// large code bases, because it is easy to lose track of the active binding at
-    /// any place in the code. This can be alleviated by either giving more specific
-    /// names to bindings or introducing more scopes to contain the bindings.
+    /// any place in the code. If linting against all shadowing is desired, you may wish
+    /// to use the `shadow_same` and `shadow_reuse` lints as well.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/single_call_fn.rs b/clippy_lints/src/single_call_fn.rs
index 2ce7e714c642..c71bc3f7fcde 100644
--- a/clippy_lints/src/single_call_fn.rs
+++ b/clippy_lints/src/single_call_fn.rs
@@ -13,13 +13,20 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for functions that are only used once. Does not lint tests.
     ///
-    /// ### Why is this bad?
-    /// It's usually not, splitting a function into multiple parts often improves readability and in
-    /// the case of generics, can prevent the compiler from duplicating the function dozens of
-    /// time; instead, only duplicating a thunk. But this can prevent segmentation across a
-    /// codebase, where many small functions are used only once.
+    /// ### Why restrict this?
+    /// If a function is only used once (perhaps because it used to be used more widely),
+    /// then the code could be simplified by moving that function's code into its caller.
     ///
-    /// Note: If this lint is used, prepare to allow this a lot.
+    /// However, there are reasons not to do this everywhere:
+    ///
+    /// * Splitting a large function into multiple parts often improves readability
+    ///   by giving names to its parts.
+    /// * A function’s signature might serve a necessary purpose, such as constraining
+    ///   the type of a closure passed to it.
+    /// * Generic functions might call non-generic functions to reduce duplication
+    ///   in the produced machine code.
+    ///
+    /// If this lint is used, prepare to `#[allow]` it a lot.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/single_char_lifetime_names.rs b/clippy_lints/src/single_char_lifetime_names.rs
index 42f1564db353..72feb977c310 100644
--- a/clippy_lints/src/single_char_lifetime_names.rs
+++ b/clippy_lints/src/single_char_lifetime_names.rs
@@ -9,11 +9,10 @@ declare_clippy_lint! {
     /// Checks for lifetimes with names which are one character
     /// long.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// A single character is likely not enough to express the
     /// purpose of a lifetime. Using a longer name can make code
-    /// easier to understand, especially for those who are new to
-    /// Rust.
+    /// easier to understand.
     ///
     /// ### Known problems
     /// Rust programmers and learning resources tend to use single
diff --git a/clippy_lints/src/std_instead_of_core.rs b/clippy_lints/src/std_instead_of_core.rs
index 926c56332cc1..12b70075a3d5 100644
--- a/clippy_lints/src/std_instead_of_core.rs
+++ b/clippy_lints/src/std_instead_of_core.rs
@@ -12,11 +12,9 @@ use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
     /// ### What it does
-    ///
     /// Finds items imported through `std` when available through `core`.
     ///
-    /// ### Why is this bad?
-    ///
+    /// ### Why restrict this?
     /// Crates which have `no_std` compatibility may wish to ensure types are imported from core to ensure
     /// disabling `std` does not cause the crate to fail to compile. This lint is also useful for crates
     /// migrating to become `no_std` compatible.
@@ -37,11 +35,9 @@ declare_clippy_lint! {
 
 declare_clippy_lint! {
     /// ### What it does
-    ///
     /// Finds items imported through `std` when available through `alloc`.
     ///
-    /// ### Why is this bad?
-    ///
+    /// ### Why restrict this?
     /// Crates which have `no_std` compatibility and require alloc may wish to ensure types are imported from
     /// alloc to ensure disabling `std` does not cause the crate to fail to compile. This lint is also useful
     /// for crates migrating to become `no_std` compatible.
@@ -63,11 +59,9 @@ declare_clippy_lint! {
 
 declare_clippy_lint! {
     /// ### What it does
-    ///
     /// Finds items imported through `alloc` when available through `core`.
     ///
-    /// ### Why is this bad?
-    ///
+    /// ### Why restrict this?
     /// Crates which have `no_std` compatibility and may optionally require alloc may wish to ensure types are
     /// imported from core to ensure disabling `alloc` does not cause the crate to fail to compile. This lint
     /// is also useful for crates migrating to become `no_std` compatible.
diff --git a/clippy_lints/src/strings.rs b/clippy_lints/src/strings.rs
index 292124196ff6..f8d36d6b92f6 100644
--- a/clippy_lints/src/strings.rs
+++ b/clippy_lints/src/strings.rs
@@ -45,10 +45,10 @@ declare_clippy_lint! {
     /// `String`, but only if [`string_add_assign`](#string_add_assign) does *not*
     /// match.
     ///
-    /// ### Why is this bad?
-    /// It's not bad in and of itself. However, this particular
+    /// ### Why restrict this?
+    /// This particular
     /// `Add` implementation is asymmetric (the other operand need not be `String`,
-    /// but `x` does), while addition as mathematically defined is symmetric, also
+    /// but `x` does), while addition as mathematically defined is symmetric, and
     /// the `String::push_str(_)` function is a perfectly good replacement.
     /// Therefore, some dislike it and wish not to have it in their code.
     ///
@@ -123,7 +123,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for slice operations on strings
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// UTF-8 characters span multiple bytes, and it is easy to inadvertently confuse character
     /// counts and string indices. This may lead to panics, and should warrant some test cases
     /// containing wide UTF-8 characters. This lint is most useful in code that should avoid
@@ -364,10 +364,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// This lint checks for `.to_string()` method calls on values of type `&str`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// The `to_string` method is also used on other types to convert them to a string.
-    /// When called on a `&str` it turns the `&str` into the owned variant `String`, which can be better
-    /// expressed with `.to_owned()`.
+    /// When called on a `&str` it turns the `&str` into the owned variant `String`, which can be
+    /// more specifically expressed with `.to_owned()`.
     ///
     /// ### Example
     /// ```no_run
@@ -415,9 +415,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// This lint checks for `.to_string()` method calls on values of type `String`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// The `to_string` method is also used on other types to convert them to a string.
-    /// When called on a `String` it only clones the `String`, which can be better expressed with `.clone()`.
+    /// When called on a `String` it only clones the `String`, which can be more specifically
+    /// expressed with `.clone()`.
     ///
     /// ### Example
     /// ```no_run
diff --git a/clippy_lints/src/suspicious_xor_used_as_pow.rs b/clippy_lints/src/suspicious_xor_used_as_pow.rs
index 1cc27670fa8b..d150a5f858aa 100644
--- a/clippy_lints/src/suspicious_xor_used_as_pow.rs
+++ b/clippy_lints/src/suspicious_xor_used_as_pow.rs
@@ -11,8 +11,10 @@ use rustc_session::declare_lint_pass;
 declare_clippy_lint! {
     /// ### What it does
     /// Warns for a Bitwise XOR (`^`) operator being probably confused as a powering. It will not trigger if any of the numbers are not in decimal.
-    /// ### Why is this bad?
+    ///
+    /// ### Why restrict this?
     /// It's most probably a typo and may lead to unexpected behaviours.
+    ///
     /// ### Example
     /// ```no_run
     /// let x = 3_i32 ^ 4_i32;
diff --git a/clippy_lints/src/tests_outside_test_module.rs b/clippy_lints/src/tests_outside_test_module.rs
index da5575826475..58e42892c41d 100644
--- a/clippy_lints/src/tests_outside_test_module.rs
+++ b/clippy_lints/src/tests_outside_test_module.rs
@@ -11,9 +11,11 @@ declare_clippy_lint! {
     /// ### What it does
     /// Triggers when a testing function (marked with the `#[test]` attribute) isn't inside a testing module
     /// (marked with `#[cfg(test)]`).
-    /// ### Why is this bad?
+    ///
+    /// ### Why restrict this?
     /// The idiomatic (and more performant) way of writing tests is inside a testing module (flagged with `#[cfg(test)]`),
     /// having test functions outside of this module is confusing and may lead to them being "hidden".
+    ///
     /// ### Example
     /// ```no_run
     /// #[test]
diff --git a/clippy_lints/src/types/mod.rs b/clippy_lints/src/types/mod.rs
index 5e45ab211efd..62ef65ca122f 100644
--- a/clippy_lints/src/types/mod.rs
+++ b/clippy_lints/src/types/mod.rs
@@ -217,7 +217,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `Rc<T>` and `Arc<T>` when `T` is a mutable buffer type such as `String` or `Vec`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Expressions such as `Rc<String>` usually have no advantage over `Rc<str>`, since
     /// it is larger and involves an extra level of indirection, and doesn't implement `Borrow<str>`.
     ///
@@ -274,7 +274,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `Rc<Mutex<T>>`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// `Rc` is used in single thread and `Mutex` is used in multi thread.
     /// Consider using `Rc<RefCell<T>>` in single thread or `Arc<Mutex<T>>` in multi thread.
     ///
diff --git a/clippy_lints/src/undocumented_unsafe_blocks.rs b/clippy_lints/src/undocumented_unsafe_blocks.rs
index 4120bb1331bd..6cf9229fdd08 100644
--- a/clippy_lints/src/undocumented_unsafe_blocks.rs
+++ b/clippy_lints/src/undocumented_unsafe_blocks.rs
@@ -38,10 +38,9 @@ declare_clippy_lint! {
     /// );
     /// ```
     ///
-    /// ### Why is this bad?
-    /// Undocumented unsafe blocks and impls can make it difficult to
-    /// read and maintain code, as well as uncover unsoundness
-    /// and bugs.
+    /// ### Why restrict this?
+    /// Undocumented unsafe blocks and impls can make it difficult to read and maintain code.
+    /// Writing out the safety justification may help in discovering unsoundness or bugs.
     ///
     /// ### Example
     /// ```no_run
@@ -67,7 +66,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for `// SAFETY: ` comments on safe code.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Safe code has no safety requirements, so there is no need to
     /// describe safety invariants.
     ///
diff --git a/clippy_lints/src/unicode.rs b/clippy_lints/src/unicode.rs
index 3d319b9fe767..d42697b31d1f 100644
--- a/clippy_lints/src/unicode.rs
+++ b/clippy_lints/src/unicode.rs
@@ -31,7 +31,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for non-ASCII characters in string and char literals.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Yeah, we know, the 90's called and wanted their charset
     /// back. Even so, there still are editors and other programs out there that
     /// don't work well with Unicode. So if the code is meant to be used
diff --git a/clippy_lints/src/unnecessary_self_imports.rs b/clippy_lints/src/unnecessary_self_imports.rs
index 528a1dfcfc10..93dff1b85796 100644
--- a/clippy_lints/src/unnecessary_self_imports.rs
+++ b/clippy_lints/src/unnecessary_self_imports.rs
@@ -9,7 +9,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for imports ending in `::{self}`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// In most cases, this can be written much more cleanly by omitting `::{self}`.
     ///
     /// ### Known problems
diff --git a/clippy_lints/src/unwrap_in_result.rs b/clippy_lints/src/unwrap_in_result.rs
index aca500590cef..197ab0f173bd 100644
--- a/clippy_lints/src/unwrap_in_result.rs
+++ b/clippy_lints/src/unwrap_in_result.rs
@@ -13,8 +13,10 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for functions of type `Result` that contain `expect()` or `unwrap()`
     ///
-    /// ### Why is this bad?
-    /// These functions promote recoverable errors to non-recoverable errors which may be undesirable in code bases which wish to avoid panics.
+    /// ### Why restrict this?
+    /// These functions promote recoverable errors to non-recoverable errors,
+    /// which may be undesirable in code bases which wish to avoid panics,
+    /// or be a bug in the specific function.
     ///
     /// ### Known problems
     /// This can cause false positives in functions that handle both recoverable and non recoverable errors.
diff --git a/clippy_lints/src/visibility.rs b/clippy_lints/src/visibility.rs
index 9818b98dd5b4..11dcceca7abb 100644
--- a/clippy_lints/src/visibility.rs
+++ b/clippy_lints/src/visibility.rs
@@ -32,7 +32,7 @@ declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of `pub(<loc>)` with `in`.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Consistency. Use it or don't, just be consistent about it.
     ///
     /// Also see the `pub_without_shorthand` lint for an alternative.
@@ -57,7 +57,7 @@ declare_clippy_lint! {
     /// Note: As you cannot write a module's path in `pub(<loc>)`, this will only trigger on
     /// `pub(super)` and the like.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// Consistency. Use it or don't, just be consistent about it.
     ///
     /// Also see the `pub_with_shorthand` lint for an alternative.
diff --git a/clippy_lints/src/write.rs b/clippy_lints/src/write.rs
index ff6ee0d10ad5..652ce88bd951 100644
--- a/clippy_lints/src/write.rs
+++ b/clippy_lints/src/write.rs
@@ -66,7 +66,7 @@ declare_clippy_lint! {
     /// Checks for printing on *stdout*. The purpose of this lint
     /// is to catch debugging remnants.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// People often print on *stdout* while debugging an
     /// application and might forget to remove those prints afterward.
     ///
@@ -88,7 +88,7 @@ declare_clippy_lint! {
     /// Checks for printing on *stderr*. The purpose of this lint
     /// is to catch debugging remnants.
     ///
-    /// ### Why is this bad?
+    /// ### Why restrict this?
     /// People often print on *stderr* while debugging an
     /// application and might forget to remove those prints afterward.
     ///
@@ -110,15 +110,18 @@ declare_clippy_lint! {
     /// Checks for usage of `Debug` formatting. The purpose of this
     /// lint is to catch debugging remnants.
     ///
-    /// ### Why is this bad?
-    /// The purpose of the `Debug` trait is to facilitate
-    /// debugging Rust code. It should not be used in user-facing output.
+    /// ### Why restrict this?
+    /// The purpose of the `Debug` trait is to facilitate debugging Rust code,
+    /// and [no guarantees are made about its output][stability].
+    /// It should not be used in user-facing output.
     ///
     /// ### Example
     /// ```no_run
     /// # let foo = "bar";
     /// println!("{:?}", foo);
     /// ```
+    ///
+    /// [stability]: https://doc.rust-lang.org/stable/std/fmt/trait.Debug.html#stability
     #[clippy::version = "pre 1.29.0"]
     pub USE_DEBUG,
     restriction,
diff --git a/clippy_utils/src/consts.rs b/clippy_utils/src/consts.rs
index f5d3967d130d..cd88ccd87cf0 100644
--- a/clippy_utils/src/consts.rs
+++ b/clippy_utils/src/consts.rs
@@ -412,8 +412,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// Simple constant folding: Insert an expression, get a constant or none.
     pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant<'tcx>> {
         match e.kind {
-            ExprKind::ConstBlock(e) |
-            ExprKind::DropTemps(e) => self.expr(e),
+            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr(e),
             ExprKind::Path(ref qpath) => {
                 self.fetch_path_and_apply(qpath, e.hir_id, self.typeck_results.expr_ty(e), |this, result| {
                     let result = mir_to_const(this.lcx, result)?;
@@ -491,8 +490,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// leaves the local crate.
     pub fn expr_is_empty(&mut self, e: &Expr<'_>) -> Option<bool> {
         match e.kind {
-            ExprKind::ConstBlock(e) |
-            ExprKind::DropTemps(e) => self.expr_is_empty(e),
+            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr_is_empty(e),
             ExprKind::Path(ref qpath) => {
                 if !self
                     .typeck_results
diff --git a/clippy_utils/src/hir_utils.rs b/clippy_utils/src/hir_utils.rs
index cc5ccd4053a2..817d4095eb53 100644
--- a/clippy_utils/src/hir_utils.rs
+++ b/clippy_utils/src/hir_utils.rs
@@ -769,7 +769,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                 // closures inherit TypeckResults
                 self.hash_expr(self.cx.tcx.hir().body(body).value);
             },
-            ExprKind::ConstBlock(ref l_id) => {
+            ExprKind::ConstBlock(l_id) => {
                 self.hash_expr(l_id);
             },
             ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index 94d4656377f9..b10830b24e1f 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -3370,3 +3370,25 @@ pub fn is_parent_stmt(cx: &LateContext<'_>, id: HirId) -> bool {
         Node::Stmt(..) | Node::Block(Block { stmts: &[], .. })
     )
 }
+
+/// Returns true if the given `expr` is a block or resembled as a block,
+/// such as `if`, `loop`, `match` expressions etc.
+pub fn is_block_like(expr: &Expr<'_>) -> bool {
+    matches!(
+        expr.kind,
+        ExprKind::Block(..) | ExprKind::ConstBlock(..) | ExprKind::If(..) | ExprKind::Loop(..) | ExprKind::Match(..)
+    )
+}
+
+/// Returns true if the given `expr` is binary expression that needs to be wrapped in parentheses.
+pub fn binary_expr_needs_parentheses(expr: &Expr<'_>) -> bool {
+    fn contains_block(expr: &Expr<'_>, is_operand: bool) -> bool {
+        match expr.kind {
+            ExprKind::Binary(_, lhs, _) => contains_block(lhs, true),
+            _ if is_block_like(expr) => is_operand,
+            _ => false,
+        }
+    }
+
+    contains_block(expr, false)
+}
diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs
index 2dacc34867f0..3414b5ef680c 100644
--- a/clippy_utils/src/ty.rs
+++ b/clippy_utils/src/ty.rs
@@ -9,7 +9,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
-use rustc_hir::{Expr, FnDecl, Safety, LangItem, TyKind};
+use rustc_hir::{Expr, FnDecl, LangItem, Safety, TyKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::Scalar;
@@ -18,8 +18,8 @@ use rustc_middle::traits::EvaluationResult;
 use rustc_middle::ty::layout::ValidityRequirement;
 use rustc_middle::ty::{
     self, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, GenericArg, GenericArgKind, GenericArgsRef,
-    GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, Upcast, TraitRef, Ty, TyCtxt,
-    TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, UintTy, VariantDef, VariantDiscr,
+    GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, TraitRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable,
+    TypeVisitableExt, TypeVisitor, UintTy, Upcast, VariantDef, VariantDiscr,
 };
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, Span, Symbol, DUMMY_SP};
diff --git a/rust-toolchain b/rust-toolchain
index a0585ffdb45b..dd8b9ece773e 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2024-05-16"
+channel = "nightly-2024-05-30"
 components = ["cargo", "llvm-tools", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]
diff --git a/tests/ui-internal/disallow_span_lint.rs b/tests/ui-internal/disallow_span_lint.rs
index b91a83308b5f..ca71dddcc24f 100644
--- a/tests/ui-internal/disallow_span_lint.rs
+++ b/tests/ui-internal/disallow_span_lint.rs
@@ -11,11 +11,15 @@ use rustc_lint::{Lint, LintContext};
 use rustc_middle::ty::TyCtxt;
 
 pub fn a(cx: impl LintContext, lint: &'static Lint, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) {
-    cx.span_lint(lint, span, |lint| { lint.primary_message(msg); });
+    cx.span_lint(lint, span, |lint| {
+        lint.primary_message(msg);
+    });
 }
 
 pub fn b(tcx: TyCtxt<'_>, lint: &'static Lint, hir_id: HirId, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) {
-    tcx.node_span_lint(lint, hir_id, span, |lint| { lint.primary_message(msg); });
+    tcx.node_span_lint(lint, hir_id, span, |lint| {
+        lint.primary_message(msg);
+    });
 }
 
 fn main() {}
diff --git a/tests/ui-internal/disallow_span_lint.stderr b/tests/ui-internal/disallow_span_lint.stderr
index 1cfbc8efc8ed..1be4b665bcba 100644
--- a/tests/ui-internal/disallow_span_lint.stderr
+++ b/tests/ui-internal/disallow_span_lint.stderr
@@ -1,18 +1,22 @@
 error: use of a disallowed method `rustc_lint::context::LintContext::span_lint`
   --> tests/ui-internal/disallow_span_lint.rs:14:5
    |
-LL |     cx.span_lint(lint, span, |lint| { lint.primary_message(msg); });
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | /     cx.span_lint(lint, span, |lint| {
+LL | |         lint.primary_message(msg);
+LL | |     });
+   | |______^
    |
    = note: this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint*` functions instead (from clippy.toml)
    = note: `-D clippy::disallowed-methods` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::disallowed_methods)]`
 
 error: use of a disallowed method `rustc_middle::ty::context::TyCtxt::node_span_lint`
-  --> tests/ui-internal/disallow_span_lint.rs:18:5
+  --> tests/ui-internal/disallow_span_lint.rs:20:5
    |
-LL |     tcx.node_span_lint(lint, hir_id, span, |lint| { lint.primary_message(msg); });
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | /     tcx.node_span_lint(lint, hir_id, span, |lint| {
+LL | |         lint.primary_message(msg);
+LL | |     });
+   | |______^
    |
    = note: this function does not add a link to our documentation, please use the `clippy_utils::diagnostics::span_lint_hir*` functions instead (from clippy.toml)
 
diff --git a/tests/ui/derive_partial_eq_without_eq.fixed b/tests/ui/derive_partial_eq_without_eq.fixed
index 6f42487bbf49..eb93eb8e8ed4 100644
--- a/tests/ui/derive_partial_eq_without_eq.fixed
+++ b/tests/ui/derive_partial_eq_without_eq.fixed
@@ -1,3 +1,4 @@
+#![feature(lint_reasons)]
 #![allow(unused)]
 #![warn(clippy::derive_partial_eq_without_eq)]
 
@@ -14,6 +15,22 @@ pub struct MissingEq {
     bar: String,
 }
 
+// Check that we honor the `allow` attribute
+#[allow(clippy::derive_partial_eq_without_eq)]
+#[derive(Debug, PartialEq)]
+pub struct AllowedMissingEq {
+    foo: u32,
+    bar: String,
+}
+
+// Check that we honor the `expect` attribute
+#[expect(clippy::derive_partial_eq_without_eq)]
+#[derive(Debug, PartialEq)]
+pub struct ExpectedMissingEq {
+    foo: u32,
+    bar: String,
+}
+
 // Eq is derived
 #[derive(PartialEq, Eq)]
 pub struct NotMissingEq {
diff --git a/tests/ui/derive_partial_eq_without_eq.rs b/tests/ui/derive_partial_eq_without_eq.rs
index 24f687c6c9db..42dc435bdd52 100644
--- a/tests/ui/derive_partial_eq_without_eq.rs
+++ b/tests/ui/derive_partial_eq_without_eq.rs
@@ -1,3 +1,4 @@
+#![feature(lint_reasons)]
 #![allow(unused)]
 #![warn(clippy::derive_partial_eq_without_eq)]
 
@@ -14,6 +15,22 @@ pub struct MissingEq {
     bar: String,
 }
 
+// Check that we honor the `allow` attribute
+#[allow(clippy::derive_partial_eq_without_eq)]
+#[derive(Debug, PartialEq)]
+pub struct AllowedMissingEq {
+    foo: u32,
+    bar: String,
+}
+
+// Check that we honor the `expect` attribute
+#[expect(clippy::derive_partial_eq_without_eq)]
+#[derive(Debug, PartialEq)]
+pub struct ExpectedMissingEq {
+    foo: u32,
+    bar: String,
+}
+
 // Eq is derived
 #[derive(PartialEq, Eq)]
 pub struct NotMissingEq {
diff --git a/tests/ui/derive_partial_eq_without_eq.stderr b/tests/ui/derive_partial_eq_without_eq.stderr
index 3d92112dc36d..29cd7da6b77d 100644
--- a/tests/ui/derive_partial_eq_without_eq.stderr
+++ b/tests/ui/derive_partial_eq_without_eq.stderr
@@ -1,5 +1,5 @@
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:11:17
+  --> tests/ui/derive_partial_eq_without_eq.rs:12:17
    |
 LL | #[derive(Debug, PartialEq)]
    |                 ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
@@ -8,73 +8,73 @@ LL | #[derive(Debug, PartialEq)]
    = help: to override `-D warnings` add `#[allow(clippy::derive_partial_eq_without_eq)]`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:53:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:70:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:59:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:76:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:65:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:82:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:68:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:85:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:74:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:91:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:80:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:97:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:93:17
+  --> tests/ui/derive_partial_eq_without_eq.rs:110:17
    |
 LL | #[derive(Debug, PartialEq, Clone)]
    |                 ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:96:10
+  --> tests/ui/derive_partial_eq_without_eq.rs:113:10
    |
 LL | #[derive(PartialEq)]
    |          ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:103:14
+  --> tests/ui/derive_partial_eq_without_eq.rs:120:14
    |
 LL |     #[derive(PartialEq)]
    |              ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:106:14
+  --> tests/ui/derive_partial_eq_without_eq.rs:123:14
    |
 LL |     #[derive(PartialEq)]
    |              ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:166:14
+  --> tests/ui/derive_partial_eq_without_eq.rs:183:14
    |
 LL |     #[derive(PartialEq)]
    |              ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
 
 error: you are deriving `PartialEq` and can implement `Eq`
-  --> tests/ui/derive_partial_eq_without_eq.rs:174:14
+  --> tests/ui/derive_partial_eq_without_eq.rs:191:14
    |
 LL |     #[derive(PartialEq)]
    |              ^^^^^^^^^ help: consider deriving `Eq` as well: `PartialEq, Eq`
diff --git a/tests/ui/doc/doc-fixable.fixed b/tests/ui/doc/doc-fixable.fixed
index 7e22c847b1bc..84673f1f43fd 100644
--- a/tests/ui/doc/doc-fixable.fixed
+++ b/tests/ui/doc/doc-fixable.fixed
@@ -240,3 +240,6 @@ extern {
     /// `foo()`
     fn in_extern();
 }
+
+/// <https://github.com/rust-lang/rust-clippy/pull/12836>
+fn check_autofix_for_base_urls() {}
diff --git a/tests/ui/doc/doc-fixable.rs b/tests/ui/doc/doc-fixable.rs
index 3e2cb0df54b0..4d017a99e0fb 100644
--- a/tests/ui/doc/doc-fixable.rs
+++ b/tests/ui/doc/doc-fixable.rs
@@ -240,3 +240,6 @@ extern {
     /// foo()
     fn in_extern();
 }
+
+/// https://github.com/rust-lang/rust-clippy/pull/12836
+fn check_autofix_for_base_urls() {}
diff --git a/tests/ui/doc/doc-fixable.stderr b/tests/ui/doc/doc-fixable.stderr
index cd2228c47e35..a9263f62d38d 100644
--- a/tests/ui/doc/doc-fixable.stderr
+++ b/tests/ui/doc/doc-fixable.stderr
@@ -363,5 +363,11 @@ help: try
 LL |     /// `foo()`
    |         ~~~~~~~
 
-error: aborting due to 33 previous errors
+error: you should put bare URLs between `<`/`>` or make a proper Markdown link
+  --> tests/ui/doc/doc-fixable.rs:244:5
+   |
+LL | /// https://github.com/rust-lang/rust-clippy/pull/12836
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `<https://github.com/rust-lang/rust-clippy/pull/12836>`
+
+error: aborting due to 34 previous errors
 
diff --git a/tests/ui/doc/issue_12795.fixed b/tests/ui/doc/issue_12795.fixed
new file mode 100644
index 000000000000..ade23bf975c2
--- /dev/null
+++ b/tests/ui/doc/issue_12795.fixed
@@ -0,0 +1,9 @@
+#![warn(clippy::doc_markdown)]
+
+//! A comment with `a_b(x)` and `a_c` in it and (`a_b((c))` ) too and (maybe `a_b((c))`)
+//~^ ERROR: item in documentation is missing backticks
+//~| ERROR: item in documentation is missing backticks
+//~| ERROR: item in documentation is missing backticks
+//~| ERROR: item in documentation is missing backticks
+
+pub fn main() {}
diff --git a/tests/ui/doc/issue_12795.rs b/tests/ui/doc/issue_12795.rs
new file mode 100644
index 000000000000..6d94a07e3036
--- /dev/null
+++ b/tests/ui/doc/issue_12795.rs
@@ -0,0 +1,9 @@
+#![warn(clippy::doc_markdown)]
+
+//! A comment with a_b(x) and a_c in it and (a_b((c)) ) too and (maybe a_b((c)))
+//~^ ERROR: item in documentation is missing backticks
+//~| ERROR: item in documentation is missing backticks
+//~| ERROR: item in documentation is missing backticks
+//~| ERROR: item in documentation is missing backticks
+
+pub fn main() {}
diff --git a/tests/ui/doc/issue_12795.stderr b/tests/ui/doc/issue_12795.stderr
new file mode 100644
index 000000000000..5700145ec8f7
--- /dev/null
+++ b/tests/ui/doc/issue_12795.stderr
@@ -0,0 +1,48 @@
+error: item in documentation is missing backticks
+  --> tests/ui/doc/issue_12795.rs:3:20
+   |
+LL | //! A comment with a_b(x) and a_c in it and (a_b((c)) ) too and (maybe a_b((c)))
+   |                    ^^^^^^
+   |
+   = note: `-D clippy::doc-markdown` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::doc_markdown)]`
+help: try
+   |
+LL | //! A comment with `a_b(x)` and a_c in it and (a_b((c)) ) too and (maybe a_b((c)))
+   |                    ~~~~~~~~
+
+error: item in documentation is missing backticks
+  --> tests/ui/doc/issue_12795.rs:3:31
+   |
+LL | //! A comment with a_b(x) and a_c in it and (a_b((c)) ) too and (maybe a_b((c)))
+   |                               ^^^
+   |
+help: try
+   |
+LL | //! A comment with a_b(x) and `a_c` in it and (a_b((c)) ) too and (maybe a_b((c)))
+   |                               ~~~~~
+
+error: item in documentation is missing backticks
+  --> tests/ui/doc/issue_12795.rs:3:46
+   |
+LL | //! A comment with a_b(x) and a_c in it and (a_b((c)) ) too and (maybe a_b((c)))
+   |                                              ^^^^^^^^
+   |
+help: try
+   |
+LL | //! A comment with a_b(x) and a_c in it and (`a_b((c))` ) too and (maybe a_b((c)))
+   |                                              ~~~~~~~~~~
+
+error: item in documentation is missing backticks
+  --> tests/ui/doc/issue_12795.rs:3:72
+   |
+LL | //! A comment with a_b(x) and a_c in it and (a_b((c)) ) too and (maybe a_b((c)))
+   |                                                                        ^^^^^^^^
+   |
+help: try
+   |
+LL | //! A comment with a_b(x) and a_c in it and (a_b((c)) ) too and (maybe `a_b((c))`)
+   |                                                                        ~~~~~~~~~~
+
+error: aborting due to 4 previous errors
+
diff --git a/tests/ui/iter_on_empty_collections.fixed b/tests/ui/iter_on_empty_collections.fixed
index 794629f240eb..0f28b48d9ab8 100644
--- a/tests/ui/iter_on_empty_collections.fixed
+++ b/tests/ui/iter_on_empty_collections.fixed
@@ -20,6 +20,28 @@ fn array() {
     };
 
     let _ = if false { ["test"].iter() } else { [].iter() };
+
+    let smth = Some(vec![1, 2, 3]);
+
+    // Don't trigger when the empty collection iter is relied upon for its concrete type
+    // But do trigger if it is just an iterator, despite being an argument to a method
+    for i in smth.as_ref().map_or([].iter(), |s| s.iter()).chain(std::iter::empty()) {
+        println!("{i}");
+    }
+
+    // Same as above, but for empty collection iters with extra layers
+    for i in smth.as_ref().map_or({ [].iter() }, |s| s.iter()) {
+        println!("{y}", y = i + 1);
+    }
+
+    // Same as above, but for regular function calls
+    for i in Option::map_or(smth.as_ref(), [].iter(), |s| s.iter()) {
+        println!("{i}");
+    }
+
+    // Same as above, but when there are no predicates that mention the collection iter type.
+    let mut iter = [34, 228, 35].iter();
+    let _ = std::mem::replace(&mut iter, [].iter());
 }
 
 macro_rules! in_macros {
diff --git a/tests/ui/iter_on_empty_collections.rs b/tests/ui/iter_on_empty_collections.rs
index a6461a702eb2..702da514df7d 100644
--- a/tests/ui/iter_on_empty_collections.rs
+++ b/tests/ui/iter_on_empty_collections.rs
@@ -20,6 +20,28 @@ fn array() {
     };
 
     let _ = if false { ["test"].iter() } else { [].iter() };
+
+    let smth = Some(vec![1, 2, 3]);
+
+    // Don't trigger when the empty collection iter is relied upon for its concrete type
+    // But do trigger if it is just an iterator, despite being an argument to a method
+    for i in smth.as_ref().map_or([].iter(), |s| s.iter()).chain([].iter()) {
+        println!("{i}");
+    }
+
+    // Same as above, but for empty collection iters with extra layers
+    for i in smth.as_ref().map_or({ [].iter() }, |s| s.iter()) {
+        println!("{y}", y = i + 1);
+    }
+
+    // Same as above, but for regular function calls
+    for i in Option::map_or(smth.as_ref(), [].iter(), |s| s.iter()) {
+        println!("{i}");
+    }
+
+    // Same as above, but when there are no predicates that mention the collection iter type.
+    let mut iter = [34, 228, 35].iter();
+    let _ = std::mem::replace(&mut iter, [].iter());
 }
 
 macro_rules! in_macros {
diff --git a/tests/ui/iter_on_empty_collections.stderr b/tests/ui/iter_on_empty_collections.stderr
index ade20ff26a01..da9caa6925bd 100644
--- a/tests/ui/iter_on_empty_collections.stderr
+++ b/tests/ui/iter_on_empty_collections.stderr
@@ -37,5 +37,11 @@ error: `iter` call on an empty collection
 LL |     assert_eq!(None.iter().next(), Option::<&i32>::None);
    |                ^^^^^^^^^^^ help: try: `std::iter::empty()`
 
-error: aborting due to 6 previous errors
+error: `iter` call on an empty collection
+  --> tests/ui/iter_on_empty_collections.rs:28:66
+   |
+LL |     for i in smth.as_ref().map_or([].iter(), |s| s.iter()).chain([].iter()) {
+   |                                                                  ^^^^^^^^^ help: try: `std::iter::empty()`
+
+error: aborting due to 7 previous errors
 
diff --git a/tests/ui/let_and_return.fixed b/tests/ui/let_and_return.fixed
index 4187019e5894..b68b41cdca23 100644
--- a/tests/ui/let_and_return.fixed
+++ b/tests/ui/let_and_return.fixed
@@ -210,4 +210,38 @@ fn issue9150() -> usize {
     x
 }
 
+fn issue12801() {
+    fn left_is_if() -> String {
+        
+        (if true { "a".to_string() } else { "b".to_string() } + "c")
+        //~^ ERROR: returning the result of a `let` binding from a block
+    }
+
+    fn no_par_needed() -> String {
+        
+        "c".to_string() + if true { "a" } else { "b" }
+        //~^ ERROR: returning the result of a `let` binding from a block
+    }
+
+    fn conjunctive_blocks() -> String {
+        
+        ({ "a".to_string() } + "b" + { "c" } + "d")
+        //~^ ERROR: returning the result of a `let` binding from a block
+    }
+
+    #[allow(clippy::overly_complex_bool_expr)]
+    fn other_ops() {
+        let _ = || {
+            
+            (if true { 2 } else { 3 } << 4)
+            //~^ ERROR: returning the result of a `let` binding from a block
+        };
+        let _ = || {
+            
+            ({ true } || { false } && { 2 <= 3 })
+            //~^ ERROR: returning the result of a `let` binding from a block
+        };
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/let_and_return.rs b/tests/ui/let_and_return.rs
index 54444957b7d5..6b9035f94288 100644
--- a/tests/ui/let_and_return.rs
+++ b/tests/ui/let_and_return.rs
@@ -210,4 +210,38 @@ fn issue9150() -> usize {
     x
 }
 
+fn issue12801() {
+    fn left_is_if() -> String {
+        let s = if true { "a".to_string() } else { "b".to_string() } + "c";
+        s
+        //~^ ERROR: returning the result of a `let` binding from a block
+    }
+
+    fn no_par_needed() -> String {
+        let s = "c".to_string() + if true { "a" } else { "b" };
+        s
+        //~^ ERROR: returning the result of a `let` binding from a block
+    }
+
+    fn conjunctive_blocks() -> String {
+        let s = { "a".to_string() } + "b" + { "c" } + "d";
+        s
+        //~^ ERROR: returning the result of a `let` binding from a block
+    }
+
+    #[allow(clippy::overly_complex_bool_expr)]
+    fn other_ops() {
+        let _ = || {
+            let s = if true { 2 } else { 3 } << 4;
+            s
+            //~^ ERROR: returning the result of a `let` binding from a block
+        };
+        let _ = || {
+            let s = { true } || { false } && { 2 <= 3 };
+            s
+            //~^ ERROR: returning the result of a `let` binding from a block
+        };
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/let_and_return.stderr b/tests/ui/let_and_return.stderr
index ff5962ec196e..75efa05d770a 100644
--- a/tests/ui/let_and_return.stderr
+++ b/tests/ui/let_and_return.stderr
@@ -78,5 +78,75 @@ LL +                 E::B(x) => x,
 LL +             }) as _
    |
 
-error: aborting due to 5 previous errors
+error: returning the result of a `let` binding from a block
+  --> tests/ui/let_and_return.rs:216:9
+   |
+LL |         let s = if true { "a".to_string() } else { "b".to_string() } + "c";
+   |         ------------------------------------------------------------------- unnecessary `let` binding
+LL |         s
+   |         ^
+   |
+help: return the expression directly
+   |
+LL ~         
+LL ~         (if true { "a".to_string() } else { "b".to_string() } + "c")
+   |
+
+error: returning the result of a `let` binding from a block
+  --> tests/ui/let_and_return.rs:222:9
+   |
+LL |         let s = "c".to_string() + if true { "a" } else { "b" };
+   |         ------------------------------------------------------- unnecessary `let` binding
+LL |         s
+   |         ^
+   |
+help: return the expression directly
+   |
+LL ~         
+LL ~         "c".to_string() + if true { "a" } else { "b" }
+   |
+
+error: returning the result of a `let` binding from a block
+  --> tests/ui/let_and_return.rs:228:9
+   |
+LL |         let s = { "a".to_string() } + "b" + { "c" } + "d";
+   |         -------------------------------------------------- unnecessary `let` binding
+LL |         s
+   |         ^
+   |
+help: return the expression directly
+   |
+LL ~         
+LL ~         ({ "a".to_string() } + "b" + { "c" } + "d")
+   |
+
+error: returning the result of a `let` binding from a block
+  --> tests/ui/let_and_return.rs:236:13
+   |
+LL |             let s = if true { 2 } else { 3 } << 4;
+   |             -------------------------------------- unnecessary `let` binding
+LL |             s
+   |             ^
+   |
+help: return the expression directly
+   |
+LL ~             
+LL ~             (if true { 2 } else { 3 } << 4)
+   |
+
+error: returning the result of a `let` binding from a block
+  --> tests/ui/let_and_return.rs:241:13
+   |
+LL |             let s = { true } || { false } && { 2 <= 3 };
+   |             -------------------------------------------- unnecessary `let` binding
+LL |             s
+   |             ^
+   |
+help: return the expression directly
+   |
+LL ~             
+LL ~             ({ true } || { false } && { 2 <= 3 })
+   |
+
+error: aborting due to 10 previous errors
 
diff --git a/tests/ui/many_single_char_names.rs b/tests/ui/many_single_char_names.rs
index 2af45eaab8af..68578340d90e 100644
--- a/tests/ui/many_single_char_names.rs
+++ b/tests/ui/many_single_char_names.rs
@@ -1,5 +1,3 @@
-//@compile-flags: -Zdeduplicate-diagnostics=yes
-
 #![allow(clippy::too_many_arguments, clippy::diverging_sub_expression)]
 #![warn(clippy::many_single_char_names)]
 
diff --git a/tests/ui/many_single_char_names.stderr b/tests/ui/many_single_char_names.stderr
index 3b2460b5c077..131836ef7c88 100644
--- a/tests/ui/many_single_char_names.stderr
+++ b/tests/ui/many_single_char_names.stderr
@@ -1,5 +1,5 @@
 error: 5 bindings with single-character names in scope
-  --> tests/ui/many_single_char_names.rs:7:9
+  --> tests/ui/many_single_char_names.rs:5:9
    |
 LL |     let a: i32;
    |         ^
@@ -14,7 +14,7 @@ LL |             let e: i32;
    = help: to override `-D warnings` add `#[allow(clippy::many_single_char_names)]`
 
 error: 6 bindings with single-character names in scope
-  --> tests/ui/many_single_char_names.rs:7:9
+  --> tests/ui/many_single_char_names.rs:5:9
    |
 LL |     let a: i32;
    |         ^
@@ -28,7 +28,7 @@ LL |             let f: i32;
    |                 ^
 
 error: 5 bindings with single-character names in scope
-  --> tests/ui/many_single_char_names.rs:7:9
+  --> tests/ui/many_single_char_names.rs:5:9
    |
 LL |     let a: i32;
    |         ^
@@ -40,13 +40,13 @@ LL |             e => panic!(),
    |             ^
 
 error: 8 bindings with single-character names in scope
-  --> tests/ui/many_single_char_names.rs:36:13
+  --> tests/ui/many_single_char_names.rs:34:13
    |
 LL | fn bindings(a: i32, b: i32, c: i32, d: i32, e: i32, f: i32, g: i32, h: i32) {}
    |             ^       ^       ^       ^       ^       ^       ^       ^
 
 error: 8 bindings with single-character names in scope
-  --> tests/ui/many_single_char_names.rs:40:10
+  --> tests/ui/many_single_char_names.rs:38:10
    |
 LL |     let (a, b, c, d, e, f, g, h): (bool, bool, bool, bool, bool, bool, bool, bool) = unimplemented!();
    |          ^  ^  ^  ^  ^  ^  ^  ^
diff --git a/tests/ui/needless_return.fixed b/tests/ui/needless_return.fixed
index 2575f2449e18..a9271cb399d8 100644
--- a/tests/ui/needless_return.fixed
+++ b/tests/ui/needless_return.fixed
@@ -323,4 +323,8 @@ fn allow_works() -> i32 {
     }
 }
 
+fn conjunctive_blocks() -> String {
+    ({ "a".to_string() } + "b" + { "c" })
+}
+
 fn main() {}
diff --git a/tests/ui/needless_return.rs b/tests/ui/needless_return.rs
index 04f21834d885..dc888bf667f1 100644
--- a/tests/ui/needless_return.rs
+++ b/tests/ui/needless_return.rs
@@ -333,4 +333,8 @@ fn allow_works() -> i32 {
     }
 }
 
+fn conjunctive_blocks() -> String {
+    return { "a".to_string() } + "b" + { "c" };
+}
+
 fn main() {}
diff --git a/tests/ui/needless_return.stderr b/tests/ui/needless_return.stderr
index 758ff6d985cd..bf5a89d8b75d 100644
--- a/tests/ui/needless_return.stderr
+++ b/tests/ui/needless_return.stderr
@@ -653,5 +653,17 @@ LL -         return if b1 { 0 } else { 1 } | if b2 { 2 } else { 3 } | if b3 { 4
 LL +         (if b1 { 0 } else { 1 } | if b2 { 2 } else { 3 } | if b3 { 4 } else { 5 })
    |
 
-error: aborting due to 52 previous errors
+error: unneeded `return` statement
+  --> tests/ui/needless_return.rs:337:5
+   |
+LL |     return { "a".to_string() } + "b" + { "c" };
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: remove `return` and wrap the sequence with parentheses
+   |
+LL -     return { "a".to_string() } + "b" + { "c" };
+LL +     ({ "a".to_string() } + "b" + { "c" })
+   |
+
+error: aborting due to 53 previous errors
 
diff --git a/tests/ui/numbered_fields.fixed b/tests/ui/numbered_fields.fixed
index dc88081ba0a7..108520eed38d 100644
--- a/tests/ui/numbered_fields.fixed
+++ b/tests/ui/numbered_fields.fixed
@@ -34,4 +34,9 @@ fn main() {
 
     // Aliases can't be tuple constructed #8638
     let _ = Alias { 0: 0, 1: 1, 2: 2 };
+
+    // Issue #12367
+    struct TupleStructVec(Vec<usize>);
+
+    let _ = TupleStructVec(vec![0, 1, 2, 3]);
 }
diff --git a/tests/ui/numbered_fields.rs b/tests/ui/numbered_fields.rs
index e8fa652e3c1d..c718661a6826 100644
--- a/tests/ui/numbered_fields.rs
+++ b/tests/ui/numbered_fields.rs
@@ -42,4 +42,9 @@ fn main() {
 
     // Aliases can't be tuple constructed #8638
     let _ = Alias { 0: 0, 1: 1, 2: 2 };
+
+    // Issue #12367
+    struct TupleStructVec(Vec<usize>);
+
+    let _ = TupleStructVec { 0: vec![0, 1, 2, 3] };
 }
diff --git a/tests/ui/numbered_fields.stderr b/tests/ui/numbered_fields.stderr
index 96426cab1e62..9d3f59cd3769 100644
--- a/tests/ui/numbered_fields.stderr
+++ b/tests/ui/numbered_fields.stderr
@@ -23,5 +23,11 @@ LL | |         1: 3u32,
 LL | |     };
    | |_____^ help: try: `TupleStruct(1u32, 3u32, 2u8)`
 
-error: aborting due to 2 previous errors
+error: used a field initializer for a tuple struct
+  --> tests/ui/numbered_fields.rs:49:13
+   |
+LL |     let _ = TupleStructVec { 0: vec![0, 1, 2, 3] };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `TupleStructVec(vec![0, 1, 2, 3])`
+
+error: aborting due to 3 previous errors
 
diff --git a/tests/ui/significant_drop_in_scrutinee.rs b/tests/ui/significant_drop_in_scrutinee.rs
index 7fc89bb95380..8ee15440ccf0 100644
--- a/tests/ui/significant_drop_in_scrutinee.rs
+++ b/tests/ui/significant_drop_in_scrutinee.rs
@@ -274,11 +274,20 @@ fn should_trigger_lint_for_tuple_in_scrutinee() {
             },
             (_, _, _) => {},
         };
+    }
+}
+
+// Should not trigger lint since `String::as_str` returns a reference (i.e., `&str`)
+// to the locked data (i.e., the `String`) and it is not surprising that matching such
+// a reference needs to keep the data locked until the end of the match block.
+fn should_not_trigger_lint_for_string_as_str() {
+    let mutex1 = Mutex::new(StateWithField { s: "one".to_owned() });
 
+    {
+        let mutex2 = Mutex::new(StateWithField { s: "two".to_owned() });
         let mutex3 = Mutex::new(StateWithField { s: "three".to_owned() });
+
         match mutex3.lock().unwrap().s.as_str() {
-            //~^ ERROR: temporary with significant `Drop` in `match` scrutinee will live until
-            //~| NOTE: this might lead to deadlocks or other unexpected behavior
             "three" => {
                 println!("started");
                 mutex1.lock().unwrap().s.len();
@@ -289,8 +298,6 @@ fn should_trigger_lint_for_tuple_in_scrutinee() {
         };
 
         match (true, mutex3.lock().unwrap().s.as_str()) {
-            //~^ ERROR: temporary with significant `Drop` in `match` scrutinee will live until
-            //~| NOTE: this might lead to deadlocks or other unexpected behavior
             (_, "three") => {
                 println!("started");
                 mutex1.lock().unwrap().s.len();
@@ -514,16 +521,15 @@ impl StateStringWithBoxedMutexGuard {
     }
 }
 
-fn should_trigger_lint_for_boxed_mutex_guard_holding_string() {
+fn should_not_trigger_lint_for_string_ref() {
     let s = StateStringWithBoxedMutexGuard::new();
 
     let matcher = String::from("A String");
 
-    // Should trigger lint because a temporary Box holding a type with a significant drop in a match
-    // scrutinee may have a potentially surprising lifetime.
+    // Should not trigger lint because the second `deref` returns a string reference (`&String`).
+    // So it is not surprising that matching the reference implies that the lock needs to be held
+    // until the end of the block.
     match s.lock().deref().deref() {
-        //~^ ERROR: temporary with significant `Drop` in `match` scrutinee will live until the
-        //~| NOTE: this might lead to deadlocks or other unexpected behavior
         matcher => println!("Value is {}", s.lock().deref()),
         _ => println!("Value was not a match"),
     };
@@ -639,13 +645,12 @@ fn should_trigger_lint_for_non_ref_move_and_clone_suggestion() {
     };
 }
 
-fn should_trigger_lint_for_read_write_lock_for_loop() {
-    // For-in loops desugar to match expressions and are prone to the type of deadlock this lint is
-    // designed to look for.
+fn should_not_trigger_lint_for_read_write_lock_for_loop() {
     let rwlock = RwLock::<Vec<String>>::new(vec!["1".to_string()]);
+    // Should not trigger lint. Since we're iterating over the data, it's obvious that the lock
+    // has to be held until the iteration finishes.
+    // https://github.com/rust-lang/rust-clippy/issues/8987
     for s in rwlock.read().unwrap().iter() {
-        //~^ ERROR: temporary with significant `Drop` in `for` loop condition will live until
-        //~| NOTE: this might lead to deadlocks or other unexpected behavior
         println!("{}", s);
     }
 }
@@ -731,4 +736,69 @@ fn should_not_trigger_for_significant_drop_ref() {
     };
 }
 
+struct Foo<'a>(&'a Vec<u32>);
+
+impl<'a> Foo<'a> {
+    fn copy_old_lifetime(&self) -> &'a Vec<u32> {
+        self.0
+    }
+
+    fn reborrow_new_lifetime(&self) -> &Vec<u32> {
+        self.0
+    }
+}
+
+fn should_trigger_lint_if_and_only_if_lifetime_is_irrelevant() {
+    let vec = Vec::new();
+    let mutex = Mutex::new(Foo(&vec));
+
+    // Should trigger lint even if `copy_old_lifetime()` has a lifetime, as the lifetime of
+    // `&vec` is unrelated to the temporary with significant drop (i.e., the `MutexGuard`).
+    for val in mutex.lock().unwrap().copy_old_lifetime() {
+        //~^ ERROR: temporary with significant `Drop` in `for` loop condition will live until the
+        //~| NOTE: this might lead to deadlocks or other unexpected behavior
+        println!("{}", val);
+    }
+
+    // Should not trigger lint because `reborrow_new_lifetime()` has a lifetime and the
+    // lifetime is related to the temporary with significant drop (i.e., the `MutexGuard`).
+    for val in mutex.lock().unwrap().reborrow_new_lifetime() {
+        println!("{}", val);
+    }
+}
+
+fn should_not_trigger_lint_for_complex_lifetime() {
+    let mutex = Mutex::new(vec!["hello".to_owned()]);
+    let string = "world".to_owned();
+
+    // Should not trigger lint due to the relevant lifetime.
+    for c in mutex.lock().unwrap().first().unwrap().chars() {
+        println!("{}", c);
+    }
+
+    // Should trigger lint due to the irrelevant lifetime.
+    //
+    // FIXME: The lifetime is too complex to analyze. In order to avoid false positives, we do not
+    // trigger lint.
+    for c in mutex.lock().unwrap().first().map(|_| &string).unwrap().chars() {
+        println!("{}", c);
+    }
+}
+
+fn should_not_trigger_lint_with_explicit_drop() {
+    let mutex = Mutex::new(vec![1]);
+
+    // Should not trigger lint since the drop explicitly happens.
+    for val in [drop(mutex.lock().unwrap()), ()] {
+        println!("{:?}", val);
+    }
+
+    // Should trigger lint if there is no explicit drop.
+    for val in [mutex.lock().unwrap()[0], 2] {
+        //~^ ERROR: temporary with significant `Drop` in `for` loop condition will live until the
+        //~| NOTE: this might lead to deadlocks or other unexpected behavior
+        println!("{:?}", val);
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/significant_drop_in_scrutinee.stderr b/tests/ui/significant_drop_in_scrutinee.stderr
index 811bb0655279..4a483e79d8ad 100644
--- a/tests/ui/significant_drop_in_scrutinee.stderr
+++ b/tests/ui/significant_drop_in_scrutinee.stderr
@@ -160,45 +160,53 @@ LL ~         match (mutex1.lock().unwrap().s.len(), true, value) {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:279:15
+  --> tests/ui/significant_drop_in_scrutinee.rs:319:11
    |
-LL |         match mutex3.lock().unwrap().s.as_str() {
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     match mutex.lock().unwrap().s.len() > 1 {
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
-LL |                 mutex1.lock().unwrap().s.len();
-   |                 ---------------------- another value with significant `Drop` created here
-LL |                 mutex2.lock().unwrap().s.len();
-   |                 ---------------------- another value with significant `Drop` created here
+LL |             mutex.lock().unwrap().s.len();
+   |             --------------------- another value with significant `Drop` created here
 ...
-LL |         };
-   |          - temporary lives until here
+LL |     };
+   |      - temporary lives until here
    |
    = note: this might lead to deadlocks or other unexpected behavior
+help: try moving the temporary above the match
+   |
+LL ~     let value = mutex.lock().unwrap().s.len();
+LL ~     match value > 1 {
+   |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:291:22
+  --> tests/ui/significant_drop_in_scrutinee.rs:328:15
    |
-LL |         match (true, mutex3.lock().unwrap().s.as_str()) {
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     match 1 < mutex.lock().unwrap().s.len() {
+   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
-LL |                 mutex1.lock().unwrap().s.len();
-   |                 ---------------------- another value with significant `Drop` created here
-LL |                 mutex2.lock().unwrap().s.len();
-   |                 ---------------------- another value with significant `Drop` created here
+LL |             mutex.lock().unwrap().s.len();
+   |             --------------------- another value with significant `Drop` created here
 ...
-LL |         };
-   |          - temporary lives until here
+LL |     };
+   |      - temporary lives until here
    |
    = note: this might lead to deadlocks or other unexpected behavior
+help: try moving the temporary above the match
+   |
+LL ~     let value = mutex.lock().unwrap().s.len();
+LL ~     match 1 < value {
+   |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:312:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:348:11
    |
-LL |     match mutex.lock().unwrap().s.len() > 1 {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     match mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len() {
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
-LL |             mutex.lock().unwrap().s.len();
-   |             --------------------- another value with significant `Drop` created here
+LL |                 mutex1.lock().unwrap().s.len(),
+   |                 ---------------------- another value with significant `Drop` created here
+LL |                 mutex2.lock().unwrap().s.len()
+   |                 ---------------------- another value with significant `Drop` created here
 ...
 LL |     };
    |      - temporary lives until here
@@ -206,18 +214,20 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     let value = mutex.lock().unwrap().s.len() > 1;
-LL ~     match value {
+LL ~     let value = mutex1.lock().unwrap().s.len();
+LL ~     match value < mutex2.lock().unwrap().s.len() {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:321:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:348:44
    |
-LL |     match 1 < mutex.lock().unwrap().s.len() {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     match mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len() {
+   |                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
-LL |             mutex.lock().unwrap().s.len();
-   |             --------------------- another value with significant `Drop` created here
+LL |                 mutex1.lock().unwrap().s.len(),
+   |                 ---------------------- another value with significant `Drop` created here
+LL |                 mutex2.lock().unwrap().s.len()
+   |                 ---------------------- another value with significant `Drop` created here
 ...
 LL |     };
    |      - temporary lives until here
@@ -225,15 +235,15 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     let value = 1 < mutex.lock().unwrap().s.len();
-LL ~     match value {
+LL ~     let value = mutex2.lock().unwrap().s.len();
+LL ~     match mutex1.lock().unwrap().s.len() < value {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:341:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:361:11
    |
-LL |     match mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len() {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     match mutex1.lock().unwrap().s.len() >= mutex2.lock().unwrap().s.len() {
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
 LL |                 mutex1.lock().unwrap().s.len(),
    |                 ---------------------- another value with significant `Drop` created here
@@ -246,15 +256,15 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     let value = mutex1.lock().unwrap().s.len() < mutex2.lock().unwrap().s.len();
-LL ~     match value {
+LL ~     let value = mutex1.lock().unwrap().s.len();
+LL ~     match value >= mutex2.lock().unwrap().s.len() {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:354:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:361:45
    |
 LL |     match mutex1.lock().unwrap().s.len() >= mutex2.lock().unwrap().s.len() {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
 LL |                 mutex1.lock().unwrap().s.len(),
    |                 ---------------------- another value with significant `Drop` created here
@@ -267,15 +277,15 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     let value = mutex1.lock().unwrap().s.len() >= mutex2.lock().unwrap().s.len();
-LL ~     match value {
+LL ~     let value = mutex2.lock().unwrap().s.len();
+LL ~     match mutex1.lock().unwrap().s.len() >= value {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:391:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:398:11
    |
 LL |     match get_mutex_guard().s.len() > 1 {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |           ^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
 LL |             mutex1.lock().unwrap().s.len();
    |             ---------------------- another value with significant `Drop` created here
@@ -286,12 +296,12 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     let value = get_mutex_guard().s.len() > 1;
-LL ~     match value {
+LL ~     let value = get_mutex_guard().s.len();
+LL ~     match value > 1 {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:410:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:417:11
    |
 LL |       match match i {
    |  ___________^
@@ -299,9 +309,9 @@ LL | |
 LL | |
 LL | |         100 => mutex1.lock().unwrap(),
 ...  |
+LL | |     .s
 LL | |     .len()
-LL | |         > 1
-   | |___________^
+   | |__________^
 ...
 LL |               mutex1.lock().unwrap().s.len();
    |               ---------------------- another value with significant `Drop` created here
@@ -319,13 +329,12 @@ LL +         100 => mutex1.lock().unwrap(),
 LL +         _ => mutex2.lock().unwrap(),
 LL +     }
 LL +     .s
-LL +     .len()
-LL +         > 1;
+LL +     .len();
 LL ~     match value
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:438:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:445:11
    |
 LL |       match if i > 1 {
    |  ___________^
@@ -333,9 +342,9 @@ LL | |
 LL | |
 LL | |         mutex1.lock().unwrap()
 ...  |
+LL | |     .s
 LL | |     .len()
-LL | |         > 1
-   | |___________^
+   | |__________^
 ...
 LL |               mutex1.lock().unwrap().s.len();
    |               ---------------------- another value with significant `Drop` created here
@@ -354,13 +363,12 @@ LL +     } else {
 LL +         mutex2.lock().unwrap()
 LL +     }
 LL +     .s
-LL +     .len()
-LL +         > 1;
+LL +     .len();
 LL ~     match value
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:494:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:501:11
    |
 LL |     match s.lock().deref().deref() {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -374,25 +382,11 @@ LL |     };
 help: try moving the temporary above the match and create a copy
    |
 LL ~     let value = *s.lock().deref().deref();
-LL ~     match value {
+LL ~     match (&value) {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:524:11
-   |
-LL |     match s.lock().deref().deref() {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^
-...
-LL |         matcher => println!("Value is {}", s.lock().deref()),
-   |                                            -------- another value with significant `Drop` created here
-LL |         _ => println!("Value was not a match"),
-LL |     };
-   |      - temporary lives until here
-   |
-   = note: this might lead to deadlocks or other unexpected behavior
-
-error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:545:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:551:11
    |
 LL |     match mutex.lock().unwrap().i = i {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -411,10 +405,10 @@ LL ~     match () {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:553:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:559:15
    |
 LL |     match i = mutex.lock().unwrap().i {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |               ^^^^^^^^^^^^^^^^^^^^^^^
 ...
 LL |             println!("{}", mutex.lock().unwrap().i);
    |                            --------------------- another value with significant `Drop` created here
@@ -425,12 +419,12 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     i = mutex.lock().unwrap().i;
-LL ~     match () {
+LL ~     let value = mutex.lock().unwrap().i;
+LL ~     match i = value {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:561:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:567:11
    |
 LL |     match mutex.lock().unwrap().i += 1 {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -449,10 +443,10 @@ LL ~     match () {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:569:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:575:16
    |
 LL |     match i += mutex.lock().unwrap().i {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |                ^^^^^^^^^^^^^^^^^^^^^^^
 ...
 LL |             println!("{}", mutex.lock().unwrap().i);
    |                            --------------------- another value with significant `Drop` created here
@@ -463,12 +457,12 @@ LL |     };
    = note: this might lead to deadlocks or other unexpected behavior
 help: try moving the temporary above the match
    |
-LL ~     i += mutex.lock().unwrap().i;
-LL ~     match () {
+LL ~     let value = mutex.lock().unwrap().i;
+LL ~     match i += value {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:634:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:640:11
    |
 LL |     match rwlock.read().unwrap().to_number() {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -477,20 +471,14 @@ LL |     };
    |      - temporary lives until here
    |
    = note: this might lead to deadlocks or other unexpected behavior
-
-error: temporary with significant `Drop` in `for` loop condition will live until the end of the `for` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:646:14
+help: try moving the temporary above the match
    |
-LL |     for s in rwlock.read().unwrap().iter() {
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-...
-LL |     }
-   |      - temporary lives until here
+LL ~     let value = rwlock.read().unwrap().to_number();
+LL ~     match value {
    |
-   = note: this might lead to deadlocks or other unexpected behavior
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:663:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:668:11
    |
 LL |     match mutex.lock().unwrap().foo() {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -506,7 +494,7 @@ LL ~     match value {
    |
 
 error: temporary with significant `Drop` in `match` scrutinee will live until the end of the `match` expression
-  --> tests/ui/significant_drop_in_scrutinee.rs:726:11
+  --> tests/ui/significant_drop_in_scrutinee.rs:731:11
    |
 LL |     match guard.take().len() {
    |           ^^^^^^^^^^^^^^^^^^
@@ -521,5 +509,37 @@ LL ~     let value = guard.take().len();
 LL ~     match value {
    |
 
+error: temporary with significant `Drop` in `for` loop condition will live until the end of the `for` expression
+  --> tests/ui/significant_drop_in_scrutinee.rs:757:16
+   |
+LL |     for val in mutex.lock().unwrap().copy_old_lifetime() {
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL |     }
+   |      - temporary lives until here
+   |
+   = note: this might lead to deadlocks or other unexpected behavior
+help: try moving the temporary above the match
+   |
+LL ~     let value = mutex.lock().unwrap().copy_old_lifetime();
+LL ~     for val in value {
+   |
+
+error: temporary with significant `Drop` in `for` loop condition will live until the end of the `for` expression
+  --> tests/ui/significant_drop_in_scrutinee.rs:797:17
+   |
+LL |     for val in [mutex.lock().unwrap()[0], 2] {
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL |     }
+   |      - temporary lives until here
+   |
+   = note: this might lead to deadlocks or other unexpected behavior
+help: try moving the temporary above the match
+   |
+LL ~     let value = mutex.lock().unwrap()[0];
+LL ~     for val in [value, 2] {
+   |
+
 error: aborting due to 27 previous errors
 
diff --git a/tests/ui/unnecessary_iter_cloned.fixed b/tests/ui/unnecessary_iter_cloned.fixed
index 2c582c90ba8c..dc5e163ff04e 100644
--- a/tests/ui/unnecessary_iter_cloned.fixed
+++ b/tests/ui/unnecessary_iter_cloned.fixed
@@ -170,3 +170,32 @@ fn check_mut_iteratee_and_modify_inner_variable() {
         }
     }
 }
+
+mod issue_12821 {
+    fn foo() {
+        let v: Vec<_> = "hello".chars().collect();
+        for c in v.iter() {
+            //~^ ERROR: unnecessary use of `cloned`
+            println!("{c}"); // should not suggest to remove `&`
+        }
+    }
+
+    fn bar() {
+        let v: Vec<_> = "hello".chars().collect();
+        for c in v.iter() {
+            //~^ ERROR: unnecessary use of `cloned`
+            let ref_c = c; //~ HELP: remove any references to the binding
+            println!("{ref_c}");
+        }
+    }
+
+    fn baz() {
+        let v: Vec<_> = "hello".chars().enumerate().collect();
+        for (i, c) in v.iter() {
+            //~^ ERROR: unnecessary use of `cloned`
+            let ref_c = c; //~ HELP: remove any references to the binding
+            let ref_i = i;
+            println!("{i} {ref_c}"); // should not suggest to remove `&` from `i`
+        }
+    }
+}
diff --git a/tests/ui/unnecessary_iter_cloned.rs b/tests/ui/unnecessary_iter_cloned.rs
index a28ccd1efef2..8f797ac717fb 100644
--- a/tests/ui/unnecessary_iter_cloned.rs
+++ b/tests/ui/unnecessary_iter_cloned.rs
@@ -170,3 +170,32 @@ fn check_mut_iteratee_and_modify_inner_variable() {
         }
     }
 }
+
+mod issue_12821 {
+    fn foo() {
+        let v: Vec<_> = "hello".chars().collect();
+        for c in v.iter().cloned() {
+            //~^ ERROR: unnecessary use of `cloned`
+            println!("{c}"); // should not suggest to remove `&`
+        }
+    }
+
+    fn bar() {
+        let v: Vec<_> = "hello".chars().collect();
+        for c in v.iter().cloned() {
+            //~^ ERROR: unnecessary use of `cloned`
+            let ref_c = &c; //~ HELP: remove any references to the binding
+            println!("{ref_c}");
+        }
+    }
+
+    fn baz() {
+        let v: Vec<_> = "hello".chars().enumerate().collect();
+        for (i, c) in v.iter().cloned() {
+            //~^ ERROR: unnecessary use of `cloned`
+            let ref_c = &c; //~ HELP: remove any references to the binding
+            let ref_i = &i;
+            println!("{i} {ref_c}"); // should not suggest to remove `&` from `i`
+        }
+    }
+}
diff --git a/tests/ui/unnecessary_iter_cloned.stderr b/tests/ui/unnecessary_iter_cloned.stderr
index fb98cfddc262..0bdb37a521fc 100644
--- a/tests/ui/unnecessary_iter_cloned.stderr
+++ b/tests/ui/unnecessary_iter_cloned.stderr
@@ -10,7 +10,7 @@ help: use
    |
 LL |     for (t, path) in files {
    |                      ~~~~~
-help: remove this `&`
+help: remove any references to the binding
    |
 LL -         let other = match get_file_path(&t) {
 LL +         let other = match get_file_path(t) {
@@ -26,11 +26,49 @@ help: use
    |
 LL |     for (t, path) in files.iter() {
    |                      ~~~~~~~~~~~~
-help: remove this `&`
+help: remove any references to the binding
    |
 LL -         let other = match get_file_path(&t) {
 LL +         let other = match get_file_path(t) {
    |
 
-error: aborting due to 2 previous errors
+error: unnecessary use of `cloned`
+  --> tests/ui/unnecessary_iter_cloned.rs:177:18
+   |
+LL |         for c in v.iter().cloned() {
+   |                  ^^^^^^^^^^^^^^^^^ help: use: `v.iter()`
+
+error: unnecessary use of `cloned`
+  --> tests/ui/unnecessary_iter_cloned.rs:185:18
+   |
+LL |         for c in v.iter().cloned() {
+   |                  ^^^^^^^^^^^^^^^^^
+   |
+help: use
+   |
+LL |         for c in v.iter() {
+   |                  ~~~~~~~~
+help: remove any references to the binding
+   |
+LL -             let ref_c = &c;
+LL +             let ref_c = c;
+   |
+
+error: unnecessary use of `cloned`
+  --> tests/ui/unnecessary_iter_cloned.rs:194:23
+   |
+LL |         for (i, c) in v.iter().cloned() {
+   |                       ^^^^^^^^^^^^^^^^^
+   |
+help: use
+   |
+LL |         for (i, c) in v.iter() {
+   |                       ~~~~~~~~
+help: remove any references to the binding
+   |
+LL ~             let ref_c = c;
+LL ~             let ref_i = i;
+   |
+
+error: aborting due to 5 previous errors
 
diff --git a/tests/ui/unnecessary_to_owned.stderr b/tests/ui/unnecessary_to_owned.stderr
index 5475df9c7b93..2829f3cd6e98 100644
--- a/tests/ui/unnecessary_to_owned.stderr
+++ b/tests/ui/unnecessary_to_owned.stderr
@@ -487,7 +487,7 @@ help: use
    |
 LL |     for t in file_types {
    |              ~~~~~~~~~~
-help: remove this `&`
+help: remove any references to the binding
    |
 LL -         let path = match get_file_path(&t) {
 LL +         let path = match get_file_path(t) {
diff --git a/tests/ui/unsafe_derive_deserialize.rs b/tests/ui/unsafe_derive_deserialize.rs
index 70dcaa3afa45..5187e0790423 100644
--- a/tests/ui/unsafe_derive_deserialize.rs
+++ b/tests/ui/unsafe_derive_deserialize.rs
@@ -1,3 +1,4 @@
+#![feature(lint_reasons)]
 #![warn(clippy::unsafe_derive_deserialize)]
 #![allow(unused, clippy::missing_safety_doc)]
 
@@ -71,4 +72,14 @@ impl G {
     }
 }
 
+// Check that we honor the `expect` attribute on the ADT
+#[expect(clippy::unsafe_derive_deserialize)]
+#[derive(Deserialize)]
+pub struct H;
+impl H {
+    pub fn unsafe_block(&self) {
+        unsafe {}
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/unsafe_derive_deserialize.stderr b/tests/ui/unsafe_derive_deserialize.stderr
index f2d4429f707a..06719f23d57f 100644
--- a/tests/ui/unsafe_derive_deserialize.stderr
+++ b/tests/ui/unsafe_derive_deserialize.stderr
@@ -1,5 +1,5 @@
 error: you are deriving `serde::Deserialize` on a type that has methods using `unsafe`
-  --> tests/ui/unsafe_derive_deserialize.rs:8:10
+  --> tests/ui/unsafe_derive_deserialize.rs:9:10
    |
 LL | #[derive(Deserialize)]
    |          ^^^^^^^^^^^
@@ -10,7 +10,7 @@ LL | #[derive(Deserialize)]
    = note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: you are deriving `serde::Deserialize` on a type that has methods using `unsafe`
-  --> tests/ui/unsafe_derive_deserialize.rs:17:10
+  --> tests/ui/unsafe_derive_deserialize.rs:18:10
    |
 LL | #[derive(Deserialize)]
    |          ^^^^^^^^^^^
@@ -19,7 +19,7 @@ LL | #[derive(Deserialize)]
    = note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: you are deriving `serde::Deserialize` on a type that has methods using `unsafe`
-  --> tests/ui/unsafe_derive_deserialize.rs:24:10
+  --> tests/ui/unsafe_derive_deserialize.rs:25:10
    |
 LL | #[derive(Deserialize)]
    |          ^^^^^^^^^^^
@@ -28,7 +28,7 @@ LL | #[derive(Deserialize)]
    = note: this error originates in the derive macro `Deserialize` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: you are deriving `serde::Deserialize` on a type that has methods using `unsafe`
-  --> tests/ui/unsafe_derive_deserialize.rs:33:10
+  --> tests/ui/unsafe_derive_deserialize.rs:34:10
    |
 LL | #[derive(Deserialize)]
    |          ^^^^^^^^^^^

From 040edea332a2767aed540b725c38a37167e17fdb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Le=C3=B3n=20Orell=20Valerian=20Liehr?= <me@fmease.dev>
Date: Mon, 27 May 2024 23:53:46 +0200
Subject: [PATCH 08/56] Rename HIR `TypeBinding` to `AssocItemConstraint` and
 related cleanup

---
 clippy_lints/src/implied_bounds_in_impls.rs | 54 ++++++++++-----------
 clippy_lints/src/len_zero.rs                | 17 +++----
 clippy_lints/src/manual_async_fn.rs         | 10 ++--
 clippy_utils/src/ast_utils.rs               |  6 +--
 clippy_utils/src/hir_utils.rs               |  8 +--
 5 files changed, 44 insertions(+), 51 deletions(-)

diff --git a/clippy_lints/src/implied_bounds_in_impls.rs b/clippy_lints/src/implied_bounds_in_impls.rs
index dc935ed3d7fe..2b389d4f9b19 100644
--- a/clippy_lints/src/implied_bounds_in_impls.rs
+++ b/clippy_lints/src/implied_bounds_in_impls.rs
@@ -3,7 +3,7 @@ use clippy_utils::source::snippet;
 use rustc_errors::{Applicability, SuggestionStyle};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{
-    GenericArg, GenericBound, GenericBounds, ItemKind, PredicateOrigin, TraitBoundModifier, TyKind, TypeBinding,
+    GenericArg, GenericBound, GenericBounds, ItemKind, PredicateOrigin, TraitBoundModifier, TyKind, AssocItemConstraint,
     WherePredicate,
 };
 use rustc_hir_analysis::lower_ty;
@@ -54,9 +54,9 @@ fn emit_lint(
     poly_trait: &rustc_hir::PolyTraitRef<'_>,
     bounds: GenericBounds<'_>,
     index: usize,
-    // The bindings that were implied, used for suggestion purposes since removing a bound with associated types
-    // means we might need to then move it to a different bound
-    implied_bindings: &[TypeBinding<'_>],
+    // The constraints that were implied, used for suggestion purposes since removing a bound with
+    // associated types means we might need to then move it to a different bound.
+    implied_constraints: &[AssocItemConstraint<'_>],
     bound: &ImplTraitBound<'_>,
 ) {
     let implied_by = snippet(cx, bound.span, "..");
@@ -83,29 +83,29 @@ fn emit_lint(
 
             let mut sugg = vec![(implied_span_extended, String::new())];
 
-            // We also might need to include associated type binding that were specified in the implied bound,
+            // We also might need to include associated item constraints that were specified in the implied bound,
             // but omitted in the implied-by bound:
             // `fn f() -> impl Deref<Target = u8> + DerefMut`
             // If we're going to suggest removing `Deref<..>`, we'll need to put `<Target = u8>` on `DerefMut`
-            let omitted_assoc_tys: Vec<_> = implied_bindings
+            let omitted_constraints: Vec<_> = implied_constraints
                 .iter()
-                .filter(|binding| !bound.bindings.iter().any(|b| b.ident == binding.ident))
+                .filter(|constraint| !bound.constraints.iter().any(|c| c.ident == constraint.ident))
                 .collect();
 
-            if !omitted_assoc_tys.is_empty() {
-                // `<>` needs to be added if there aren't yet any generic arguments or bindings
-                let needs_angle_brackets = bound.args.is_empty() && bound.bindings.is_empty();
-                let insert_span = match (bound.args, bound.bindings) {
-                    ([.., arg], [.., binding]) => arg.span().max(binding.span).shrink_to_hi(),
+            if !omitted_constraints.is_empty() {
+                // `<>` needs to be added if there aren't yet any generic arguments or constraints
+                let needs_angle_brackets = bound.args.is_empty() && bound.constraints.is_empty();
+                let insert_span = match (bound.args, bound.constraints) {
+                    ([.., arg], [.., constraint]) => arg.span().max(constraint.span).shrink_to_hi(),
                     ([.., arg], []) => arg.span().shrink_to_hi(),
-                    ([], [.., binding]) => binding.span.shrink_to_hi(),
+                    ([], [.., constraint]) => constraint.span.shrink_to_hi(),
                     ([], []) => bound.span.shrink_to_hi(),
                 };
 
-                let mut associated_tys_sugg = if needs_angle_brackets {
+                let mut constraints_sugg = if needs_angle_brackets {
                     "<".to_owned()
                 } else {
-                    // If angle brackets aren't needed (i.e., there are already generic arguments or bindings),
+                    // If angle brackets aren't needed (i.e., there are already generic arguments or constraints),
                     // we need to add a comma:
                     // `impl A<B, C >`
                     //             ^ if we insert `Assoc=i32` without a comma here, that'd be invalid syntax:
@@ -113,16 +113,16 @@ fn emit_lint(
                     ", ".to_owned()
                 };
 
-                for (index, binding) in omitted_assoc_tys.into_iter().enumerate() {
+                for (index, constraint) in omitted_constraints.into_iter().enumerate() {
                     if index > 0 {
-                        associated_tys_sugg += ", ";
+                        constraints_sugg += ", ";
                     }
-                    associated_tys_sugg += &snippet(cx, binding.span, "..");
+                    constraints_sugg += &snippet(cx, constraint.span, "..");
                 }
                 if needs_angle_brackets {
-                    associated_tys_sugg += ">";
+                    constraints_sugg += ">";
                 }
-                sugg.push((insert_span, associated_tys_sugg));
+                sugg.push((insert_span, constraints_sugg));
             }
 
             diag.multipart_suggestion_with_style(
@@ -229,8 +229,8 @@ struct ImplTraitBound<'tcx> {
     trait_def_id: DefId,
     /// The generic arguments on the `impl Trait` bound
     args: &'tcx [GenericArg<'tcx>],
-    /// The associated types on this bound
-    bindings: &'tcx [TypeBinding<'tcx>],
+    /// The associated item constraints of this bound
+    constraints: &'tcx [AssocItemConstraint<'tcx>],
 }
 
 /// Given an `impl Trait` type, gets all the supertraits from each bound ("implied bounds").
@@ -253,7 +253,7 @@ fn collect_supertrait_bounds<'tcx>(cx: &LateContext<'tcx>, bounds: GenericBounds
                 Some(ImplTraitBound {
                     predicates,
                     args: path.args.map_or([].as_slice(), |p| p.args),
-                    bindings: path.args.map_or([].as_slice(), |p| p.bindings),
+                    constraints: path.args.map_or([].as_slice(), |p| p.constraints),
                     trait_def_id,
                     span: bound.span(),
                 })
@@ -310,20 +310,20 @@ fn check<'tcx>(cx: &LateContext<'tcx>, bounds: GenericBounds<'tcx>) {
         if let GenericBound::Trait(poly_trait, TraitBoundModifier::None) = bound
             && let [.., path] = poly_trait.trait_ref.path.segments
             && let implied_args = path.args.map_or([].as_slice(), |a| a.args)
-            && let implied_bindings = path.args.map_or([].as_slice(), |a| a.bindings)
+            && let implied_constraints = path.args.map_or([].as_slice(), |a| a.constraints)
             && let Some(def_id) = poly_trait.trait_ref.path.res.opt_def_id()
             && let Some(bound) = find_bound_in_supertraits(cx, def_id, implied_args, &supertraits)
             // If the implied bound has a type binding that also exists in the implied-by trait,
             // then we shouldn't lint. See #11880 for an example.
             && let assocs = cx.tcx.associated_items(bound.trait_def_id)
-            && !implied_bindings.iter().any(|binding| {
+            && !implied_constraints.iter().any(|constraint| {
                 assocs
-                    .filter_by_name_unhygienic(binding.ident.name)
+                    .filter_by_name_unhygienic(constraint.ident.name)
                     .next()
                     .is_some_and(|assoc| assoc.kind == ty::AssocKind::Type)
                 })
         {
-            emit_lint(cx, poly_trait, bounds, index, implied_bindings, bound);
+            emit_lint(cx, poly_trait, bounds, index, implied_constraints, bound);
         }
     }
 }
diff --git a/clippy_lints/src/len_zero.rs b/clippy_lints/src/len_zero.rs
index 97a245b76d44..2091e74665fb 100644
--- a/clippy_lints/src/len_zero.rs
+++ b/clippy_lints/src/len_zero.rs
@@ -9,7 +9,7 @@ use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::{
     AssocItemKind, BinOpKind, Expr, ExprKind, FnRetTy, GenericArg, GenericBound, ImplItem, ImplItemKind,
     ImplicitSelfKind, Item, ItemKind, Mutability, Node, OpaqueTyOrigin, PatKind, PathSegment, PrimTy, QPath,
-    TraitItemRef, TyKind, TypeBindingKind,
+    TraitItemRef, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, AssocKind, FnSig, Ty};
@@ -307,17 +307,12 @@ fn extract_future_output<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<&
         && let [GenericBound::Trait(trait_ref, _)] = &opaque.bounds
         && let Some(segment) = trait_ref.trait_ref.path.segments.last()
         && let Some(generic_args) = segment.args
-        && generic_args.bindings.len() == 1
-        && let TypeBindingKind::Equality {
-            term:
-                rustc_hir::Term::Ty(rustc_hir::Ty {
-                    kind: TyKind::Path(QPath::Resolved(_, path)),
-                    ..
-                }),
-        } = &generic_args.bindings[0].kind
-        && path.segments.len() == 1
+        && let [constraint] = generic_args.constraints
+        && let Some(ty) = constraint.ty()
+        && let TyKind::Path(QPath::Resolved(_, path)) = ty.kind
+        && let [segment] = path.segments
     {
-        return Some(&path.segments[0]);
+        return Some(segment);
     }
 
     None
diff --git a/clippy_lints/src/manual_async_fn.rs b/clippy_lints/src/manual_async_fn.rs
index 4cd5f3b81e52..25c7e5d38b31 100644
--- a/clippy_lints/src/manual_async_fn.rs
+++ b/clippy_lints/src/manual_async_fn.rs
@@ -4,8 +4,7 @@ use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
     Block, Body, Closure, ClosureKind, CoroutineDesugaring, CoroutineKind, CoroutineSource, Expr, ExprKind, FnDecl,
-    FnRetTy, GenericArg, GenericBound, ImplItem, Item, ItemKind, LifetimeName, Node, Term, TraitRef, Ty, TyKind,
-    TypeBindingKind,
+    FnRetTy, GenericArg, GenericBound, ImplItem, Item, ItemKind, LifetimeName, Node, TraitRef, Ty, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
@@ -138,10 +137,9 @@ fn future_trait_ref<'tcx>(
 fn future_output_ty<'tcx>(trait_ref: &'tcx TraitRef<'tcx>) -> Option<&'tcx Ty<'tcx>> {
     if let Some(segment) = trait_ref.path.segments.last()
         && let Some(args) = segment.args
-        && args.bindings.len() == 1
-        && let binding = &args.bindings[0]
-        && binding.ident.name == sym::Output
-        && let TypeBindingKind::Equality { term: Term::Ty(output) } = binding.kind
+        && let [constraint] = args.constraints
+        && constraint.ident.name == sym::Output
+        && let Some(output) = constraint.ty()
     {
         return Some(output);
     }
diff --git a/clippy_utils/src/ast_utils.rs b/clippy_utils/src/ast_utils.rs
index d4a5f547211a..bbdde3049dbd 100644
--- a/clippy_utils/src/ast_utils.rs
+++ b/clippy_utils/src/ast_utils.rs
@@ -108,7 +108,7 @@ pub fn eq_generic_args(l: &GenericArgs, r: &GenericArgs) -> bool {
 pub fn eq_angle_arg(l: &AngleBracketedArg, r: &AngleBracketedArg) -> bool {
     match (l, r) {
         (AngleBracketedArg::Arg(l), AngleBracketedArg::Arg(r)) => eq_generic_arg(l, r),
-        (AngleBracketedArg::Constraint(l), AngleBracketedArg::Constraint(r)) => eq_assoc_constraint(l, r),
+        (AngleBracketedArg::Constraint(l), AngleBracketedArg::Constraint(r)) => eq_assoc_item_constraint(l, r),
         _ => false,
     }
 }
@@ -802,8 +802,8 @@ fn eq_term(l: &Term, r: &Term) -> bool {
     }
 }
 
-pub fn eq_assoc_constraint(l: &AssocConstraint, r: &AssocConstraint) -> bool {
-    use AssocConstraintKind::*;
+pub fn eq_assoc_item_constraint(l: &AssocItemConstraint, r: &AssocItemConstraint) -> bool {
+    use AssocItemConstraintKind::*;
     eq_id(l.ident, r.ident)
         && match (&l.kind, &r.kind) {
             (Equality { term: l }, Equality { term: r }) => eq_term(l, r),
diff --git a/clippy_utils/src/hir_utils.rs b/clippy_utils/src/hir_utils.rs
index 9f285621e0c9..36634817fc91 100644
--- a/clippy_utils/src/hir_utils.rs
+++ b/clippy_utils/src/hir_utils.rs
@@ -9,7 +9,7 @@ use rustc_hir::MatchSource::TryDesugar;
 use rustc_hir::{
     ArrayLen, BinOpKind, BindingMode, Block, BodyId, Closure, Expr, ExprField, ExprKind, FnRetTy, GenericArg,
     GenericArgs, HirId, HirIdMap, InlineAsmOperand, LetExpr, Lifetime, LifetimeName, Pat, PatField, PatKind, Path,
-    PathSegment, PrimTy, QPath, Stmt, StmtKind, Ty, TyKind, TypeBinding,
+    PathSegment, PrimTy, QPath, Stmt, StmtKind, Ty, TyKind, AssocItemConstraint,
 };
 use rustc_lexer::{tokenize, TokenKind};
 use rustc_lint::LateContext;
@@ -486,7 +486,7 @@ impl HirEqInterExpr<'_, '_, '_> {
     fn eq_path_parameters(&mut self, left: &GenericArgs<'_>, right: &GenericArgs<'_>) -> bool {
         if left.parenthesized == right.parenthesized {
             over(left.args, right.args, |l, r| self.eq_generic_arg(l, r)) // FIXME(flip1995): may not work
-                && over(left.bindings, right.bindings, |l, r| self.eq_type_binding(l, r))
+                && over(left.constraints, right.constraints, |l, r| self.eq_assoc_type_binding(l, r))
         } else {
             false
         }
@@ -518,8 +518,8 @@ 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 eq_assoc_type_binding(&mut self, left: &AssocItemConstraint<'_>, right: &AssocItemConstraint<'_>) -> bool {
+        left.ident.name == right.ident.name && self.eq_ty(left.ty().expect("expected assoc type binding"), right.ty().expect("expected assoc type binding"))
     }
 
     fn check_ctxt(&mut self, left: SyntaxContext, right: SyntaxContext) -> bool {

From 2334264463eee8aab8c4ebd642f80131d60603b8 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Sat, 27 Apr 2024 13:58:37 -0400
Subject: [PATCH 09/56] Deduplicate supertrait_def_ids code

---
 clippy_lints/src/len_zero.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_lints/src/len_zero.rs b/clippy_lints/src/len_zero.rs
index 2091e74665fb..57e0a7aa2c7e 100644
--- a/clippy_lints/src/len_zero.rs
+++ b/clippy_lints/src/len_zero.rs
@@ -253,7 +253,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
     // fill the set with current and super traits
     fn fill_trait_set(traitt: DefId, set: &mut DefIdSet, cx: &LateContext<'_>) {
         if set.insert(traitt) {
-            for supertrait in rustc_trait_selection::traits::supertrait_def_ids(cx.tcx, traitt) {
+            for supertrait in cx.tcx.supertrait_def_ids(traitt) {
                 fill_trait_set(supertrait, set, cx);
             }
         }

From 5a44877a394569261cd53b23003113272349cf68 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 31 May 2024 14:13:46 -0400
Subject: [PATCH 10/56] Uplift TypeRelation and Relate

---
 clippy_lints/src/eta_reduction.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/eta_reduction.rs b/clippy_lints/src/eta_reduction.rs
index b58018ca0353..48c4c4206fe8 100644
--- a/clippy_lints/src/eta_reduction.rs
+++ b/clippy_lints/src/eta_reduction.rs
@@ -10,7 +10,7 @@ use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{
     self, Binder, ClosureArgs, ClosureKind, FnSig, GenericArg, GenericArgKind, List, Region, RegionKind, Ty,
-    TypeVisitableExt, TypeckResults,
+    TypeVisitableExt, TypeckResults, TyCtxt,
 };
 use rustc_session::declare_lint_pass;
 use rustc_span::symbol::sym;
@@ -240,7 +240,7 @@ fn check_inputs(
         })
 }
 
-fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure: ClosureArgs<'tcx>, call_sig: FnSig<'_>) -> bool {
+fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure: ClosureArgs<TyCtxt<'tcx>>, call_sig: FnSig<'_>) -> bool {
     call_sig.safety == Safety::Safe
         && !has_late_bound_to_non_late_bound_regions(
             cx.tcx.signature_unclosure(closure.sig(), Safety::Safe).skip_binder(),

From 5e60afb6cc733bd78ffd0e4f6233309c2cd4ea99 Mon Sep 17 00:00:00 2001
From: John Arundel <john@bitfieldconsulting.com>
Date: Mon, 3 Jun 2024 12:33:03 +0100
Subject: [PATCH 11/56] [ arc_with_non_send_sync ]: fix doc nits

---
 clippy_lints/src/arc_with_non_send_sync.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_lints/src/arc_with_non_send_sync.rs b/clippy_lints/src/arc_with_non_send_sync.rs
index 389338973894..d57ab539fff4 100644
--- a/clippy_lints/src/arc_with_non_send_sync.rs
+++ b/clippy_lints/src/arc_with_non_send_sync.rs
@@ -17,7 +17,7 @@ declare_clippy_lint! {
     /// `Arc<T>` is a thread-safe `Rc<T>` and guarantees that updates to the reference counter
     /// use atomic operations. To send an `Arc<T>` across thread boundaries and
     /// share ownership between multiple threads, `T` must be [both `Send` and `Sync`](https://doc.rust-lang.org/std/sync/struct.Arc.html#thread-safety),
-    /// so either `T` should be made `Send + Sync` or an `Rc` should be used instead of an `Arc`
+    /// so either `T` should be made `Send + Sync` or an `Rc` should be used instead of an `Arc`.
     ///
     /// ### Example
     /// ```no_run

From e94779a396619b63b99dd6494a5a940c59518d8e Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Sat, 1 Jun 2024 14:51:31 -0400
Subject: [PATCH 12/56] Opt-in diagnostics reporting to avoid doing extra work
 in the new solver

---
 clippy_lints/src/future_not_send.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_lints/src/future_not_send.rs b/clippy_lints/src/future_not_send.rs
index 192fb611c2d4..cb1d0de1edff 100644
--- a/clippy_lints/src/future_not_send.rs
+++ b/clippy_lints/src/future_not_send.rs
@@ -79,7 +79,7 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
                 let send_trait = cx.tcx.get_diagnostic_item(sym::Send).unwrap();
                 let span = decl.output.span();
                 let infcx = cx.tcx.infer_ctxt().build();
-                let ocx = ObligationCtxt::new(&infcx);
+                let ocx = ObligationCtxt::new_with_diagnostics(&infcx);
                 let cause = traits::ObligationCause::misc(span, fn_def_id);
                 ocx.register_bound(cause, cx.param_env, ret_ty, send_trait);
                 let send_errors = ocx.select_all_or_error();

From 9f4a2dd1475638fda91f5cf54650b55b320575fe Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Wed, 29 May 2024 22:23:49 -0400
Subject: [PATCH 13/56] Align Term methods with GenericArg methods

---
 .../src/methods/iter_on_single_or_empty_collections.rs      | 2 +-
 clippy_lints/src/needless_borrows_for_generic_args.rs       | 4 ++--
 clippy_lints/src/unit_return_expecting_ord.rs               | 4 ++--
 clippy_utils/src/ty.rs                                      | 6 +++---
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs b/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs
index f4397212cf66..7f6b666e434e 100644
--- a/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs
+++ b/clippy_lints/src/methods/iter_on_single_or_empty_collections.rs
@@ -42,7 +42,7 @@ fn is_arg_ty_unified_in_fn<'tcx>(
     cx.tcx.predicates_of(fn_id).predicates.iter().any(|(clause, _)| {
         clause
             .as_projection_clause()
-            .and_then(|p| p.map_bound(|p| p.term.ty()).transpose())
+            .and_then(|p| p.map_bound(|p| p.term.as_type()).transpose())
             .is_some_and(|ty| ty.skip_binder() == arg_ty_in_args)
     }) || fn_sig
         .inputs()
diff --git a/clippy_lints/src/needless_borrows_for_generic_args.rs b/clippy_lints/src/needless_borrows_for_generic_args.rs
index 5b5e1c234245..4f99eaa40c29 100644
--- a/clippy_lints/src/needless_borrows_for_generic_args.rs
+++ b/clippy_lints/src/needless_borrows_for_generic_args.rs
@@ -311,7 +311,7 @@ fn is_mixed_projection_predicate<'tcx>(
 ) -> bool {
     let generics = cx.tcx.generics_of(callee_def_id);
     // The predicate requires the projected type to equal a type parameter from the parent context.
-    if let Some(term_ty) = projection_predicate.term.ty()
+    if let Some(term_ty) = projection_predicate.term.as_type()
         && let ty::Param(term_param_ty) = term_ty.kind()
         && (term_param_ty.index as usize) < generics.parent_count
     {
@@ -370,7 +370,7 @@ fn replace_types<'tcx>(
         if replaced.insert(param_ty.index) {
             for projection_predicate in projection_predicates {
                 if projection_predicate.projection_term.self_ty() == param_ty.to_ty(cx.tcx)
-                    && let Some(term_ty) = projection_predicate.term.ty()
+                    && let Some(term_ty) = projection_predicate.term.as_type()
                     && let ty::Param(term_param_ty) = term_ty.kind()
                 {
                     let projection = projection_predicate
diff --git a/clippy_lints/src/unit_return_expecting_ord.rs b/clippy_lints/src/unit_return_expecting_ord.rs
index f0d1458a59b2..a8cc2f979633 100644
--- a/clippy_lints/src/unit_return_expecting_ord.rs
+++ b/clippy_lints/src/unit_return_expecting_ord.rs
@@ -100,12 +100,12 @@ fn get_args_to_check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Ve
                     {
                         if ord_preds
                             .iter()
-                            .any(|ord| Some(ord.self_ty()) == return_ty_pred.term.ty())
+                            .any(|ord| Some(ord.self_ty()) == return_ty_pred.term.as_type())
                         {
                             args_to_check.push((i, "Ord".to_string()));
                         } else if partial_ord_preds
                             .iter()
-                            .any(|pord| pord.self_ty() == return_ty_pred.term.ty().unwrap())
+                            .any(|pord| pord.self_ty() == return_ty_pred.term.expect_type())
                         {
                             args_to_check.push((i, "PartialOrd".to_string()));
                         }
diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs
index 3414b5ef680c..f0dac6f5d9c4 100644
--- a/clippy_utils/src/ty.rs
+++ b/clippy_utils/src/ty.rs
@@ -750,7 +750,7 @@ pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'t
                     let output = bounds
                         .projection_bounds()
                         .find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
-                        .map(|p| p.map_bound(|p| p.term.ty().unwrap()));
+                        .map(|p| p.map_bound(|p| p.term.expect_type()));
                     Some(ExprFnSig::Trait(bound.map_bound(|b| b.args.type_at(0)), output, None))
                 },
                 _ => None,
@@ -798,7 +798,7 @@ fn sig_from_bounds<'tcx>(
                     // Multiple different fn trait impls. Is this even allowed?
                     return None;
                 }
-                output = Some(pred.kind().rebind(p.term.ty().unwrap()));
+                output = Some(pred.kind().rebind(p.term.expect_type()));
             },
             _ => (),
         }
@@ -836,7 +836,7 @@ fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: AliasTy<'tcx>) -> Option
                     // Multiple different fn trait impls. Is this even allowed?
                     return None;
                 }
-                output = pred.kind().rebind(p.term.ty()).transpose();
+                output = pred.kind().rebind(p.term.as_type()).transpose();
             },
             _ => (),
         }

From 537ce5c8c6d4f592461ff883b95b61a14a4932ae Mon Sep 17 00:00:00 2001
From: Santiago Pastorino <spastorino@gmail.com>
Date: Thu, 23 May 2024 10:01:05 -0300
Subject: [PATCH 14/56] Handle  safety keyword for extern block inner items

---
 clippy_utils/src/ast_utils.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/clippy_utils/src/ast_utils.rs b/clippy_utils/src/ast_utils.rs
index bbdde3049dbd..14f9ef8966d6 100644
--- a/clippy_utils/src/ast_utils.rs
+++ b/clippy_utils/src/ast_utils.rs
@@ -451,13 +451,15 @@ pub fn eq_foreign_item_kind(l: &ForeignItemKind, r: &ForeignItemKind) -> bool {
                 ty: lt,
                 mutability: lm,
                 expr: le,
+                safety: ls,
             }),
             Static(box StaticForeignItem {
                 ty: rt,
                 mutability: rm,
                 expr: re,
+                safety: rs,
             }),
-        ) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
+        ) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re) && ls == rs,
         (
             Fn(box ast::Fn {
                 defaultness: ld,

From bd0f90824274d20bcace9d0149f1ffb0450e23cc Mon Sep 17 00:00:00 2001
From: Santiago Pastorino <spastorino@gmail.com>
Date: Tue, 7 May 2024 14:43:23 +0200
Subject: [PATCH 15/56] Add safe/unsafe to static inside extern blocks

---
 clippy_utils/src/ast_utils.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/clippy_utils/src/ast_utils.rs b/clippy_utils/src/ast_utils.rs
index 14f9ef8966d6..c70f5c2df842 100644
--- a/clippy_utils/src/ast_utils.rs
+++ b/clippy_utils/src/ast_utils.rs
@@ -308,13 +308,15 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
                 ty: lt,
                 mutability: lm,
                 expr: le,
+                safety: ls,
             }),
             Static(box StaticItem {
                 ty: rt,
                 mutability: rm,
                 expr: re,
+                safety: rs,
             }),
-        ) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
+        ) => lm == rm && ls == rs && eq_ty(lt, rt) && eq_expr_opt(le, re),
         (
             Const(box ConstItem {
                 defaultness: ld,

From e8d02fe1cb20a21e0bee2f80f1e16945eb3b9437 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Fri, 31 May 2024 15:43:18 +1000
Subject: [PATCH 16/56] Make top-level `rustc_parse` functions fallible.

Currently we have an awkward mix of fallible and infallible functions:
```
       new_parser_from_source_str
 maybe_new_parser_from_source_str
       new_parser_from_file
(maybe_new_parser_from_file)        // missing
      (new_parser_from_source_file) // missing
 maybe_new_parser_from_source_file
       source_str_to_stream
 maybe_source_file_to_stream
```
We could add the two missing functions, but instead this commit removes
of all the infallible ones and renames the fallible ones leaving us with
these which are all fallible:
```
new_parser_from_source_str
new_parser_from_file
new_parser_from_source_file
source_str_to_stream
source_file_to_stream
```
This requires making `unwrap_or_emit_fatal` public so callers of
formerly infallible functions can still work.

This does make some of the call sites slightly more verbose, but I think
it's worth it for the simpler API. Also, there are two `catch_unwind`
calls and one `catch_fatal_errors` call in this diff that become
removable thanks this change. (I will do that in a follow-up PR.)
---
 clippy_lints/src/doc/needless_doctest_main.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/doc/needless_doctest_main.rs b/clippy_lints/src/doc/needless_doctest_main.rs
index 651f2ebaee6f..c3e3c0431e6b 100644
--- a/clippy_lints/src/doc/needless_doctest_main.rs
+++ b/clippy_lints/src/doc/needless_doctest_main.rs
@@ -8,7 +8,7 @@ use rustc_data_structures::sync::Lrc;
 use rustc_errors::emitter::HumanEmitter;
 use rustc_errors::{Diag, DiagCtxt};
 use rustc_lint::LateContext;
-use rustc_parse::maybe_new_parser_from_source_str;
+use rustc_parse::new_parser_from_source_str;
 use rustc_parse::parser::ForceCollect;
 use rustc_session::parse::ParseSess;
 use rustc_span::edition::Edition;
@@ -50,7 +50,7 @@ pub fn check(
                 let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
                 let psess = ParseSess::with_dcx(dcx, sm);
 
-                let mut parser = match maybe_new_parser_from_source_str(&psess, filename, code) {
+                let mut parser = match new_parser_from_source_str(&psess, filename, code) {
                     Ok(p) => p,
                     Err(errs) => {
                         errs.into_iter().for_each(Diag::cancel);

From 38de6e1f3a48fc7a18448a3117f2db72c5fb356e Mon Sep 17 00:00:00 2001
From: Boxy <supbscripter@gmail.com>
Date: Tue, 4 Jun 2024 07:01:58 +0100
Subject: [PATCH 17/56] Misc fixes to cranelift/clippy/miri

---
 clippy_lints/src/large_const_arrays.rs       | 2 +-
 clippy_lints/src/large_stack_arrays.rs       | 2 +-
 clippy_lints/src/matches/overlapping_arms.rs | 4 ++--
 clippy_lints/src/zero_repeat_side_effects.rs | 2 +-
 clippy_utils/src/lib.rs                      | 4 ++--
 5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/clippy_lints/src/large_const_arrays.rs b/clippy_lints/src/large_const_arrays.rs
index b561054b5824..77d05020c828 100644
--- a/clippy_lints/src/large_const_arrays.rs
+++ b/clippy_lints/src/large_const_arrays.rs
@@ -54,7 +54,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeConstArrays {
             && generics.params.is_empty() && !generics.has_where_clause_predicates
             && let ty = cx.tcx.type_of(item.owner_id).instantiate_identity()
             && let ty::Array(element_type, cst) = ty.kind()
-            && let ConstKind::Value(ty::ValTree::Leaf(element_count)) = cst.kind()
+            && let ConstKind::Value(_, ty::ValTree::Leaf(element_count)) = cst.kind()
             && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx)
             && let Ok(element_size) = cx.layout_of(*element_type).map(|l| l.size.bytes())
             && self.maximum_allowed_size < u128::from(element_count) * u128::from(element_size)
diff --git a/clippy_lints/src/large_stack_arrays.rs b/clippy_lints/src/large_stack_arrays.rs
index 208d1bb6e68a..f0f3f53647b9 100644
--- a/clippy_lints/src/large_stack_arrays.rs
+++ b/clippy_lints/src/large_stack_arrays.rs
@@ -64,7 +64,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeStackArrays {
         if let ExprKind::Repeat(_, _) | ExprKind::Array(_) = expr.kind
             && !self.is_from_vec_macro(cx, expr.span)
             && let ty::Array(element_type, cst) = cx.typeck_results().expr_ty(expr).kind()
-            && let ConstKind::Value(ty::ValTree::Leaf(element_count)) = cst.kind()
+            && let ConstKind::Value(_, ty::ValTree::Leaf(element_count)) = cst.kind()
             && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx)
             && let Ok(element_size) = cx.layout_of(*element_type).map(|l| l.size.bytes())
             && !cx.tcx.hir().parent_iter(expr.hir_id).any(|(_, node)| {
diff --git a/clippy_lints/src/matches/overlapping_arms.rs b/clippy_lints/src/matches/overlapping_arms.rs
index 8199366d175f..45b375dbe3d7 100644
--- a/clippy_lints/src/matches/overlapping_arms.rs
+++ b/clippy_lints/src/matches/overlapping_arms.rs
@@ -37,14 +37,14 @@ fn all_ranges<'tcx>(cx: &LateContext<'tcx>, arms: &'tcx [Arm<'_>], ty: Ty<'tcx>)
                         Some(lhs) => constant(cx, cx.typeck_results(), lhs)?,
                         None => {
                             let min_val_const = ty.numeric_min_val(cx.tcx)?;
-                            mir_to_const(cx, mir::Const::from_ty_const(min_val_const, cx.tcx))?
+                            mir_to_const(cx, mir::Const::from_ty_const(min_val_const, ty, cx.tcx))?
                         },
                     };
                     let rhs_const = match rhs {
                         Some(rhs) => constant(cx, cx.typeck_results(), rhs)?,
                         None => {
                             let max_val_const = ty.numeric_max_val(cx.tcx)?;
-                            mir_to_const(cx, mir::Const::from_ty_const(max_val_const, cx.tcx))?
+                            mir_to_const(cx, mir::Const::from_ty_const(max_val_const, ty, cx.tcx))?
                         },
                     };
                     let lhs_val = lhs_const.int_value(cx, ty)?;
diff --git a/clippy_lints/src/zero_repeat_side_effects.rs b/clippy_lints/src/zero_repeat_side_effects.rs
index 143fecdd237d..848b49130dc2 100644
--- a/clippy_lints/src/zero_repeat_side_effects.rs
+++ b/clippy_lints/src/zero_repeat_side_effects.rs
@@ -55,7 +55,7 @@ impl LateLintPass<'_> for ZeroRepeatSideEffects {
             inner_check(cx, expr, inner_expr, true);
         } else if let ExprKind::Repeat(inner_expr, _) = expr.kind
             && let ty::Array(_, cst) = cx.typeck_results().expr_ty(expr).kind()
-            && let ConstKind::Value(ty::ValTree::Leaf(element_count)) = cst.kind()
+            && let ConstKind::Value(_, ty::ValTree::Leaf(element_count)) = cst.kind()
             && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx)
             && element_count == 0
         {
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index b10830b24e1f..1147dce6215f 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -1534,7 +1534,7 @@ pub fn is_range_full(cx: &LateContext<'_>, expr: &Expr<'_>, container_path: Opti
             if let rustc_ty::Adt(_, subst) = ty.kind()
                 && let bnd_ty = subst.type_at(0)
                 && let Some(min_val) = bnd_ty.numeric_min_val(cx.tcx)
-                && let Some(min_const) = mir_to_const(cx, Const::from_ty_const(min_val, cx.tcx))
+                && let Some(min_const) = mir_to_const(cx, Const::from_ty_const(min_val, bnd_ty, cx.tcx))
                 && let Some(start_const) = constant(cx, cx.typeck_results(), start)
             {
                 start_const == min_const
@@ -1547,7 +1547,7 @@ pub fn is_range_full(cx: &LateContext<'_>, expr: &Expr<'_>, container_path: Opti
                 if let rustc_ty::Adt(_, subst) = ty.kind()
                     && let bnd_ty = subst.type_at(0)
                     && let Some(max_val) = bnd_ty.numeric_max_val(cx.tcx)
-                    && let Some(max_const) = mir_to_const(cx, Const::from_ty_const(max_val, cx.tcx))
+                    && let Some(max_const) = mir_to_const(cx, Const::from_ty_const(max_val, bnd_ty, cx.tcx))
                     && let Some(end_const) = constant(cx, cx.typeck_results(), end)
                 {
                     end_const == max_const

From c245cde61cbe914dcf5c46a072a2b3cd0c694f0b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Thu, 6 Jun 2024 09:45:50 +0000
Subject: [PATCH 18/56] Revert "Rollup merge of #124976 -
 petrochenkov:usedcrates, r=oli-obk"

This reverts commit eda4a35f365535af72118118a3597edf5a13c12d, reversing
changes made to eb6b35b5bcb3c2a594cb29cd478aeb2893f49d30.
---
 clippy_utils/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index 1147dce6215f..2f6bf9209677 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -647,7 +647,7 @@ fn item_children_by_name(tcx: TyCtxt<'_>, def_id: DefId, name: Symbol) -> Vec<Re
 /// This function is expensive and should be used sparingly.
 pub fn def_path_res(cx: &LateContext<'_>, path: &[&str]) -> Vec<Res> {
     fn find_crates(tcx: TyCtxt<'_>, name: Symbol) -> impl Iterator<Item = DefId> + '_ {
-        tcx.crates_including_speculative(())
+        tcx.crates(())
             .iter()
             .copied()
             .filter(move |&num| tcx.crate_name(num) == name)

From 7ab4af336cdb8b13cb39e192913f84e8b7f30dda Mon Sep 17 00:00:00 2001
From: John Arundel <john@bitfieldconsulting.com>
Date: Mon, 3 Jun 2024 12:34:05 +0100
Subject: [PATCH 19/56] [ needless_for_each ]: fix doc nits

---
 clippy_lints/src/needless_for_each.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/clippy_lints/src/needless_for_each.rs b/clippy_lints/src/needless_for_each.rs
index 630018238f4c..143acc2b1cb7 100644
--- a/clippy_lints/src/needless_for_each.rs
+++ b/clippy_lints/src/needless_for_each.rs
@@ -25,14 +25,14 @@ declare_clippy_lint! {
     /// ```no_run
     /// let v = vec![0, 1, 2];
     /// v.iter().for_each(|elem| {
-    ///     println!("{}", elem);
+    ///     println!("{elem}");
     /// })
     /// ```
     /// Use instead:
     /// ```no_run
     /// let v = vec![0, 1, 2];
-    /// for elem in v.iter() {
-    ///     println!("{}", elem);
+    /// for elem in &v {
+    ///     println!("{elem}");
     /// }
     /// ```
     ///

From 35d284fcbf947089315beccb6d1af7396d09d5d3 Mon Sep 17 00:00:00 2001
From: John Arundel <john@bitfieldconsulting.com>
Date: Mon, 3 Jun 2024 12:36:01 +0100
Subject: [PATCH 20/56] [ allow_attributes ]: fix doc nits

---
 clippy_lints/src/allow_attributes.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/clippy_lints/src/allow_attributes.rs b/clippy_lints/src/allow_attributes.rs
index 123d0e51eeee..990f724ab9d9 100644
--- a/clippy_lints/src/allow_attributes.rs
+++ b/clippy_lints/src/allow_attributes.rs
@@ -10,20 +10,19 @@ use rustc_session::declare_lint_pass;
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for usage of the `#[allow]` attribute and suggests replacing it with
-    /// the `#[expect]` (See [RFC 2383](https://rust-lang.github.io/rfcs/2383-lint-reasons.html))
+    /// `#[expect]`. (See [RFC 2383](https://rust-lang.github.io/rfcs/2383-lint-reasons.html))
     ///
-    /// The expect attribute is still unstable and requires the `lint_reasons`
+    /// The expect attribute is still unstable and requires the `lint_reasons` feature
     /// on nightly. It can be enabled by adding `#![feature(lint_reasons)]` to
     /// the crate root.
     ///
-    /// This lint only warns outer attributes (`#[allow]`), as inner attributes
+    /// This lint only warns on outer attributes (`#[allow]`), as inner attributes
     /// (`#![allow]`) are usually used to enable or disable lints on a global scale.
     ///
     /// ### Why restrict this?
-    /// `#[allow]` attributes can linger after their reason for existence is gone.
-    /// `#[expect]` attributes suppress the lint emission, but emit a warning if
-    /// the expectation is unfulfilled. This can be useful to be notified when the
-    /// lint is no longer triggered, which may indicate the attribute can be removed.
+    /// The `#[allow]` attribute does not warn when the expected lint is no longer triggered,
+    /// whereas `#[expect]` calls attention to this fact. This can be a useful reminder to
+    /// remove attributes that are no longer needed.
     ///
     /// ### Example
     /// ```rust,ignore

From 8da5d64669c18b52c4edaaf71a739585d97a5767 Mon Sep 17 00:00:00 2001
From: John Arundel <john@bitfieldconsulting.com>
Date: Mon, 3 Jun 2024 12:38:25 +0100
Subject: [PATCH 21/56] [ allow_attributes_without_reason ]: fix doc nits

---
 clippy_lints/src/attrs/mod.rs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/clippy_lints/src/attrs/mod.rs b/clippy_lints/src/attrs/mod.rs
index 83c828e8e223..bd10ebbe5f5d 100644
--- a/clippy_lints/src/attrs/mod.rs
+++ b/clippy_lints/src/attrs/mod.rs
@@ -270,13 +270,14 @@ declare_clippy_lint! {
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for attributes that allow lints without a reason.
-    ///
-    /// (This requires the `lint_reasons` feature)
+    /// Checks for attributes that allow lints without specifying the reason
+    /// they should be allowed. (This requires the `lint_reasons` feature.)
     ///
     /// ### Why restrict this?
-    /// Justifying each `allow` helps readers understand the reasoning,
-    /// and may allow removing `allow` attributes if their purpose is obsolete.
+    /// There should always be a specific reason to allow a lint. This reason
+    /// should be documented using the `reason` parameter, so that readers can
+    /// understand why the `allow` is required, or remove it if it's no
+    /// longer needed.
     ///
     /// ### Example
     /// ```no_run

From 7c86db4ea5f051e0b355e37959264bd9998a17a9 Mon Sep 17 00:00:00 2001
From: John Arundel <john@bitfieldconsulting.com>
Date: Mon, 3 Jun 2024 12:41:21 +0100
Subject: [PATCH 22/56] [ mut_range_bound ]: fix doc nits

---
 clippy_lints/src/loops/mod.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/clippy_lints/src/loops/mod.rs b/clippy_lints/src/loops/mod.rs
index 086829421530..64ea591993da 100644
--- a/clippy_lints/src/loops/mod.rs
+++ b/clippy_lints/src/loops/mod.rs
@@ -356,10 +356,10 @@ declare_clippy_lint! {
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for loops which have a range bound that is a mutable variable
+    /// Checks for loops with a range bound that is a mutable variable.
     ///
     /// ### Why is this bad?
-    /// One might think that modifying the mutable variable changes the loop bounds
+    /// One might think that modifying the mutable variable changes the loop bounds. It doesn't.
     ///
     /// ### Known problems
     /// False positive when mutation is followed by a `break`, but the `break` is not immediately
@@ -381,7 +381,7 @@ declare_clippy_lint! {
     /// let mut foo = 42;
     /// for i in 0..foo {
     ///     foo -= 1;
-    ///     println!("{}", i); // prints numbers from 0 to 42, not 0 to 21
+    ///     println!("{i}"); // prints numbers from 0 to 41, not 0 to 21
     /// }
     /// ```
     #[clippy::version = "pre 1.29.0"]

From 1e23449678e4c986b609ed7a82ae6497e7b6ddd1 Mon Sep 17 00:00:00 2001
From: Samuel Tardieu <sam@rfc1149.net>
Date: Sat, 25 May 2024 18:15:14 +0200
Subject: [PATCH 23/56] Move `is_receiver_of_method_call` to `clippy_utils` for
 reuse

---
 clippy_lints/src/methods/search_is_some.rs | 12 +-----------
 clippy_utils/src/lib.rs                    | 11 +++++++++++
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/clippy_lints/src/methods/search_is_some.rs b/clippy_lints/src/methods/search_is_some.rs
index f5f1e94bbf45..3b2dd285b8c9 100644
--- a/clippy_lints/src/methods/search_is_some.rs
+++ b/clippy_lints/src/methods/search_is_some.rs
@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
 use clippy_utils::source::{snippet, snippet_with_applicability};
 use clippy_utils::sugg::deref_closure_args;
 use clippy_utils::ty::is_type_lang_item;
-use clippy_utils::{get_parent_expr, is_trait_method, strip_pat_refs};
+use clippy_utils::{is_receiver_of_method_call, is_trait_method, strip_pat_refs};
 use hir::ExprKind;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
@@ -156,13 +156,3 @@ pub(super) fn check<'tcx>(
         }
     }
 }
-
-fn is_receiver_of_method_call(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
-    if let Some(parent_expr) = get_parent_expr(cx, expr)
-        && let ExprKind::MethodCall(_, receiver, ..) = parent_expr.kind
-        && receiver.hir_id == expr.hir_id
-    {
-        return true;
-    }
-    false
-}
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index 6d6c4ffbe5d6..6b00e793eaab 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -3401,3 +3401,14 @@ pub fn binary_expr_needs_parentheses(expr: &Expr<'_>) -> bool {
 
     contains_block(expr, false)
 }
+
+/// Returns true if the specified expression is in a receiver position.
+pub fn is_receiver_of_method_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+    if let Some(parent_expr) = get_parent_expr(cx, expr)
+        && let ExprKind::MethodCall(_, receiver, ..) = parent_expr.kind
+        && receiver.hir_id == expr.hir_id
+    {
+        return true;
+    }
+    false
+}

From 35b2aa99f3357a69d09f247ed5aff64cdd7765b1 Mon Sep 17 00:00:00 2001
From: Samuel Tardieu <sam@rfc1149.net>
Date: Sat, 25 May 2024 18:08:14 +0200
Subject: [PATCH 24/56] Add required parentheses around method receiver

---
 clippy_lints/src/needless_bool.rs     | 13 ++++++++++---
 tests/ui/needless_bool/fixable.fixed  | 12 ++++++++++++
 tests/ui/needless_bool/fixable.rs     | 12 ++++++++++++
 tests/ui/needless_bool/fixable.stderr | 20 +++++++++++++++++++-
 4 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/clippy_lints/src/needless_bool.rs b/clippy_lints/src/needless_bool.rs
index e1866eaa18a7..9cb4fa41c73f 100644
--- a/clippy_lints/src/needless_bool.rs
+++ b/clippy_lints/src/needless_bool.rs
@@ -6,8 +6,8 @@ use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{
-    higher, is_block_like, is_else_clause, is_expn_of, is_parent_stmt, peel_blocks, peel_blocks_with_stmt,
-    span_extract_comment, SpanlessEq,
+    get_parent_expr, higher, is_block_like, is_else_clause, is_expn_of, is_parent_stmt, is_receiver_of_method_call,
+    peel_blocks, peel_blocks_with_stmt, span_extract_comment, SpanlessEq,
 };
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
@@ -154,7 +154,10 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBool {
                     snip = snip.blockify();
                 }
 
-                if condition_needs_parentheses(cond) && is_parent_stmt(cx, e.hir_id) {
+                if (condition_needs_parentheses(cond) && is_parent_stmt(cx, e.hir_id))
+                    || is_receiver_of_method_call(cx, e)
+                    || is_as_argument(cx, e)
+                {
                     snip = snip.maybe_par();
                 }
 
@@ -442,3 +445,7 @@ fn fetch_assign<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<(&'tcx Expr<'tcx>, bool)
         None
     }
 }
+
+fn is_as_argument(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
+    matches!(get_parent_expr(cx, e).map(|e| e.kind), Some(ExprKind::Cast(_, _)))
+}
diff --git a/tests/ui/needless_bool/fixable.fixed b/tests/ui/needless_bool/fixable.fixed
index 3059de8f89c4..ec63c4fd6a26 100644
--- a/tests/ui/needless_bool/fixable.fixed
+++ b/tests/ui/needless_bool/fixable.fixed
@@ -131,3 +131,15 @@ fn needless_bool_condition() -> bool {
 
     foo()
 }
+
+fn issue12846() {
+    let a = true;
+    let b = false;
+
+    // parentheses are needed here
+    let _x = (a && b).then(|| todo!());
+    let _x = (a && b) as u8;
+
+    // parentheses are not needed here
+    let _x = a.then(|| todo!());
+}
diff --git a/tests/ui/needless_bool/fixable.rs b/tests/ui/needless_bool/fixable.rs
index b2cbe86e2235..8694aa715908 100644
--- a/tests/ui/needless_bool/fixable.rs
+++ b/tests/ui/needless_bool/fixable.rs
@@ -191,3 +191,15 @@ fn needless_bool_condition() -> bool {
 
     foo()
 }
+
+fn issue12846() {
+    let a = true;
+    let b = false;
+
+    // parentheses are needed here
+    let _x = if a && b { true } else { false }.then(|| todo!());
+    let _x = if a && b { true } else { false } as u8;
+
+    // parentheses are not needed here
+    let _x = if a { true } else { false }.then(|| todo!());
+}
diff --git a/tests/ui/needless_bool/fixable.stderr b/tests/ui/needless_bool/fixable.stderr
index 9746e931f50f..99b5b9983448 100644
--- a/tests/ui/needless_bool/fixable.stderr
+++ b/tests/ui/needless_bool/fixable.stderr
@@ -191,5 +191,23 @@ error: this if-then-else expression returns a bool literal
 LL |         if unsafe { no(4) } & 1 != 0 { true } else { false }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `(unsafe { no(4) } & 1 != 0)`
 
-error: aborting due to 21 previous errors
+error: this if-then-else expression returns a bool literal
+  --> tests/ui/needless_bool/fixable.rs:200:14
+   |
+LL |     let _x = if a && b { true } else { false }.then(|| todo!());
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `(a && b)`
+
+error: this if-then-else expression returns a bool literal
+  --> tests/ui/needless_bool/fixable.rs:201:14
+   |
+LL |     let _x = if a && b { true } else { false } as u8;
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `(a && b)`
+
+error: this if-then-else expression returns a bool literal
+  --> tests/ui/needless_bool/fixable.rs:204:14
+   |
+LL |     let _x = if a { true } else { false }.then(|| todo!());
+   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: you can reduce it to: `a`
+
+error: aborting due to 24 previous errors
 

From 5ea5f6351e29ebbac17d1d45d87322bec8793b83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Thu, 6 Jun 2024 20:39:54 +0000
Subject: [PATCH 25/56] Revert "Rollup merge of #124099 -
 voidc:disallow-ambiguous-expr-attrs, r=davidtwco"

This reverts commit 57dad1d75e562ff73051c1c43b07eaf65c7dbd74, reversing
changes made to 36316df9fe6c3e246153fe6e78967643cf08c148.
---
 tests/ui/cfg_attr_rustfmt.fixed | 6 +++---
 tests/ui/cfg_attr_rustfmt.rs    | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tests/ui/cfg_attr_rustfmt.fixed b/tests/ui/cfg_attr_rustfmt.fixed
index 84dac431169a..05d5b3d10eaf 100644
--- a/tests/ui/cfg_attr_rustfmt.fixed
+++ b/tests/ui/cfg_attr_rustfmt.fixed
@@ -16,7 +16,7 @@ fn foo(
 
 fn skip_on_statements() {
     #[rustfmt::skip]
-    { 5+3; }
+    5+3;
 }
 
 #[rustfmt::skip]
@@ -33,11 +33,11 @@ mod foo {
 #[clippy::msrv = "1.29"]
 fn msrv_1_29() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 1+29; }
+    1+29;
 }
 
 #[clippy::msrv = "1.30"]
 fn msrv_1_30() {
     #[rustfmt::skip]
-    { 1+30; }
+    1+30;
 }
diff --git a/tests/ui/cfg_attr_rustfmt.rs b/tests/ui/cfg_attr_rustfmt.rs
index 4ab5c70e13b5..bc29e20210e8 100644
--- a/tests/ui/cfg_attr_rustfmt.rs
+++ b/tests/ui/cfg_attr_rustfmt.rs
@@ -16,7 +16,7 @@ fn foo(
 
 fn skip_on_statements() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 5+3; }
+    5+3;
 }
 
 #[cfg_attr(rustfmt, rustfmt_skip)]
@@ -33,11 +33,11 @@ mod foo {
 #[clippy::msrv = "1.29"]
 fn msrv_1_29() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 1+29; }
+    1+29;
 }
 
 #[clippy::msrv = "1.30"]
 fn msrv_1_30() {
     #[cfg_attr(rustfmt, rustfmt::skip)]
-    { 1+30; }
+    1+30;
 }

From 246d4fe79120976d484a4a57359ee951aedb4ce9 Mon Sep 17 00:00:00 2001
From: Slanterns <slanterns.w@gmail.com>
Date: Fri, 7 Jun 2024 08:37:05 +0800
Subject: [PATCH 26/56] bless `std_instead_of_core`

---
 tests/ui/std_instead_of_core.fixed  | 4 ++--
 tests/ui/std_instead_of_core.rs     | 2 +-
 tests/ui/std_instead_of_core.stderr | 8 +++++++-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/tests/ui/std_instead_of_core.fixed b/tests/ui/std_instead_of_core.fixed
index ec4ae2ea13c5..6ede7bfcd9f6 100644
--- a/tests/ui/std_instead_of_core.fixed
+++ b/tests/ui/std_instead_of_core.fixed
@@ -45,8 +45,8 @@ fn std_instead_of_core() {
 
     let _ = std::env!("PATH");
 
-    // do not lint until `error_in_core` is stable
-    use std::error::Error;
+    use core::error::Error;
+    //~^ ERROR: used import from `std` instead of `core`
 
     // lint items re-exported from private modules, `core::iter::traits::iterator::Iterator`
     use core::iter::Iterator;
diff --git a/tests/ui/std_instead_of_core.rs b/tests/ui/std_instead_of_core.rs
index c12c459c7eb4..e22b4f61f3ec 100644
--- a/tests/ui/std_instead_of_core.rs
+++ b/tests/ui/std_instead_of_core.rs
@@ -45,8 +45,8 @@ fn std_instead_of_core() {
 
     let _ = std::env!("PATH");
 
-    // do not lint until `error_in_core` is stable
     use std::error::Error;
+    //~^ ERROR: used import from `std` instead of `core`
 
     // lint items re-exported from private modules, `core::iter::traits::iterator::Iterator`
     use std::iter::Iterator;
diff --git a/tests/ui/std_instead_of_core.stderr b/tests/ui/std_instead_of_core.stderr
index 8f920511cc5d..22cb9db7050b 100644
--- a/tests/ui/std_instead_of_core.stderr
+++ b/tests/ui/std_instead_of_core.stderr
@@ -49,6 +49,12 @@ error: used import from `std` instead of `core`
 LL |     let cell_absolute = ::std::cell::Cell::new(8u32);
    |                           ^^^ help: consider importing the item from `core`: `core`
 
+error: used import from `std` instead of `core`
+  --> tests/ui/std_instead_of_core.rs:48:9
+   |
+LL |     use std::error::Error;
+   |         ^^^ help: consider importing the item from `core`: `core`
+
 error: used import from `std` instead of `core`
   --> tests/ui/std_instead_of_core.rs:52:9
    |
@@ -79,5 +85,5 @@ LL |     use alloc::slice::from_ref;
    = note: `-D clippy::alloc-instead-of-core` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::alloc_instead_of_core)]`
 
-error: aborting due to 12 previous errors
+error: aborting due to 13 previous errors
 

From abd011638dffe2586a382b4e89823bf2b84b5a4d Mon Sep 17 00:00:00 2001
From: Oli Scherer <git-spam-no-reply9815368754983@oli-obk.de>
Date: Mon, 3 Jun 2024 09:11:58 +0000
Subject: [PATCH 27/56] Revert "Create const block DefIds in typeck instead of
 ast lowering"

This reverts commit ddc5f9b6c1f21da5d4596bf7980185a00984ac42.
---
 clippy_utils/src/consts.rs              |  6 ++---
 clippy_utils/src/hir_utils.rs           |  6 ++---
 tests/ui/arithmetic_side_effects.stderr | 32 ++++---------------------
 3 files changed, 10 insertions(+), 34 deletions(-)

diff --git a/clippy_utils/src/consts.rs b/clippy_utils/src/consts.rs
index cd88ccd87cf0..5c9cad2b45d4 100644
--- a/clippy_utils/src/consts.rs
+++ b/clippy_utils/src/consts.rs
@@ -6,7 +6,7 @@ use crate::{clip, is_direct_expn_of, sext, unsext};
 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_hir::{BinOp, BinOpKind, Block, ConstBlock, Expr, ExprKind, HirId, Item, ItemKind, Node, QPath, UnOp};
 use rustc_lexer::tokenize;
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::{alloc_range, Scalar};
@@ -412,7 +412,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// Simple constant folding: Insert an expression, get a constant or none.
     pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant<'tcx>> {
         match e.kind {
-            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr(e),
+            ExprKind::ConstBlock(ConstBlock { body, .. }) => self.expr(self.lcx.tcx.hir().body(body).value), ExprKind::DropTemps(e) => self.expr(e),
             ExprKind::Path(ref qpath) => {
                 self.fetch_path_and_apply(qpath, e.hir_id, self.typeck_results.expr_ty(e), |this, result| {
                     let result = mir_to_const(this.lcx, result)?;
@@ -490,7 +490,7 @@ impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
     /// leaves the local crate.
     pub fn expr_is_empty(&mut self, e: &Expr<'_>) -> Option<bool> {
         match e.kind {
-            ExprKind::ConstBlock(e) | ExprKind::DropTemps(e) => self.expr_is_empty(e),
+            ExprKind::ConstBlock(ConstBlock { body, .. }) => self.expr_is_empty(self.lcx.tcx.hir().body(body).value), ExprKind::DropTemps(e) => self.expr_is_empty(e),
             ExprKind::Path(ref qpath) => {
                 if !self
                     .typeck_results
diff --git a/clippy_utils/src/hir_utils.rs b/clippy_utils/src/hir_utils.rs
index c649c1794684..36634817fc91 100644
--- a/clippy_utils/src/hir_utils.rs
+++ b/clippy_utils/src/hir_utils.rs
@@ -295,7 +295,7 @@ impl HirEqInterExpr<'_, '_, '_> {
                 self.eq_expr(lx, rx) && self.eq_ty(lt, rt)
             },
             (&ExprKind::Closure(_l), &ExprKind::Closure(_r)) => false,
-            (&ExprKind::ConstBlock(lb), &ExprKind::ConstBlock(rb)) => self.eq_expr(lb, rb),
+            (&ExprKind::ConstBlock(lb), &ExprKind::ConstBlock(rb)) => self.eq_body(lb.body, rb.body),
             (&ExprKind::Continue(li), &ExprKind::Continue(ri)) => {
                 both(&li.label, &ri.label, |l, r| l.ident.name == r.ident.name)
             },
@@ -769,8 +769,8 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                 // closures inherit TypeckResults
                 self.hash_expr(self.cx.tcx.hir().body(body).value);
             },
-            ExprKind::ConstBlock(l_id) => {
-                self.hash_expr(l_id);
+            ExprKind::ConstBlock(ref l_id) => {
+                self.hash_body(l_id.body);
             },
             ExprKind::DropTemps(e) | ExprKind::Yield(e, _) => {
                 self.hash_expr(e);
diff --git a/tests/ui/arithmetic_side_effects.stderr b/tests/ui/arithmetic_side_effects.stderr
index df14ff396f6c..8039c0bfa248 100644
--- a/tests/ui/arithmetic_side_effects.stderr
+++ b/tests/ui/arithmetic_side_effects.stderr
@@ -1,35 +1,11 @@
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:188:36
-   |
-LL |     let _ = const { let mut n = 1; n += 1; n };
-   |                                    ^^^^^^
-   |
-   = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings`
-   = help: to override `-D warnings` add `#[allow(clippy::arithmetic_side_effects)]`
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:191:40
-   |
-LL |     let _ = const { let mut n = 1; n = n + 1; n };
-   |                                        ^^^^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:194:40
-   |
-LL |     let _ = const { let mut n = 1; n = 1 + n; n };
-   |                                        ^^^^^
-
-error: arithmetic operation that can potentially result in unexpected side-effects
-  --> tests/ui/arithmetic_side_effects.rs:200:59
-   |
-LL |     let _ = const { let mut n = 1; n = -1; n = -(-1); n = -n; n };
-   |                                                           ^^
-
 error: arithmetic operation that can potentially result in unexpected side-effects
   --> tests/ui/arithmetic_side_effects.rs:304:5
    |
 LL |     _n += 1;
    |     ^^^^^^^
+   |
+   = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::arithmetic_side_effects)]`
 
 error: arithmetic operation that can potentially result in unexpected side-effects
   --> tests/ui/arithmetic_side_effects.rs:305:5
@@ -751,5 +727,5 @@ error: arithmetic operation that can potentially result in unexpected side-effec
 LL |     one.sub_assign(1);
    |     ^^^^^^^^^^^^^^^^^
 
-error: aborting due to 125 previous errors
+error: aborting due to 121 previous errors
 

From b21ee38fa91b8a917e7cde983806c77a9b0c5c99 Mon Sep 17 00:00:00 2001
From: Alex Macleod <alex@macleod.io>
Date: Wed, 15 May 2024 17:30:11 +0000
Subject: [PATCH 28/56] Don't lint blocks in closures for blocks_in_conditions

---
 clippy_lints/src/blocks_in_conditions.rs     | 32 +------
 tests/ui/blocks_in_conditions.fixed          | 13 +++
 tests/ui/blocks_in_conditions.rs             | 13 +++
 tests/ui/blocks_in_conditions_closure.rs     | 89 --------------------
 tests/ui/blocks_in_conditions_closure.stderr | 39 ---------
 5 files changed, 28 insertions(+), 158 deletions(-)
 delete mode 100644 tests/ui/blocks_in_conditions_closure.rs
 delete mode 100644 tests/ui/blocks_in_conditions_closure.stderr

diff --git a/clippy_lints/src/blocks_in_conditions.rs b/clippy_lints/src/blocks_in_conditions.rs
index 869ed332b9c9..eb05dc96cdeb 100644
--- a/clippy_lints/src/blocks_in_conditions.rs
+++ b/clippy_lints/src/blocks_in_conditions.rs
@@ -1,15 +1,11 @@
-use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg};
+use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_block_with_applicability;
-use clippy_utils::ty::implements_trait;
-use clippy_utils::visitors::{for_each_expr_without_closures, Descend};
-use clippy_utils::{get_parent_expr, higher, is_from_proc_macro};
-use core::ops::ControlFlow;
+use clippy_utils::{higher, is_from_proc_macro};
 use rustc_errors::Applicability;
 use rustc_hir::{BlockCheckMode, Expr, ExprKind, MatchSource};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::declare_lint_pass;
-use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -124,30 +120,6 @@ impl<'tcx> LateLintPass<'tcx> for BlocksInConditions {
                     );
                 }
             }
-        } else {
-            let _: Option<!> = for_each_expr_without_closures(cond, |e| {
-                if let ExprKind::Closure(closure) = e.kind {
-                    // do not lint if the closure is called using an iterator (see #1141)
-                    if let Some(parent) = get_parent_expr(cx, e)
-                        && let ExprKind::MethodCall(_, self_arg, _, _) = &parent.kind
-                        && let caller = cx.typeck_results().expr_ty(self_arg)
-                        && let Some(iter_id) = cx.tcx.get_diagnostic_item(sym::Iterator)
-                        && implements_trait(cx, caller, iter_id, &[])
-                    {
-                        return ControlFlow::Continue(Descend::No);
-                    }
-
-                    let body = cx.tcx.hir().body(closure.body);
-                    let ex = &body.value;
-                    if let ExprKind::Block(block, _) = ex.kind {
-                        if !body.value.span.from_expansion() && !block.stmts.is_empty() {
-                            span_lint(cx, BLOCKS_IN_CONDITIONS, ex.span, complex_block_message.clone());
-                            return ControlFlow::Continue(Descend::No);
-                        }
-                    }
-                }
-                ControlFlow::Continue(Descend::Yes)
-            });
         }
     }
 }
diff --git a/tests/ui/blocks_in_conditions.fixed b/tests/ui/blocks_in_conditions.fixed
index a2da5f9c5fb9..af8e65270d09 100644
--- a/tests/ui/blocks_in_conditions.fixed
+++ b/tests/ui/blocks_in_conditions.fixed
@@ -117,4 +117,17 @@ mod issue_12016 {
     }
 }
 
+fn in_closure() {
+    let v = vec![1, 2, 3];
+    if v.into_iter()
+        .filter(|x| {
+            let y = x + 1;
+            y > 3
+        })
+        .any(|x| x == 5)
+    {
+        println!("contains 4!");
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/blocks_in_conditions.rs b/tests/ui/blocks_in_conditions.rs
index 608ca4cf267f..6adae951a290 100644
--- a/tests/ui/blocks_in_conditions.rs
+++ b/tests/ui/blocks_in_conditions.rs
@@ -117,4 +117,17 @@ mod issue_12016 {
     }
 }
 
+fn in_closure() {
+    let v = vec![1, 2, 3];
+    if v.into_iter()
+        .filter(|x| {
+            let y = x + 1;
+            y > 3
+        })
+        .any(|x| x == 5)
+    {
+        println!("contains 4!");
+    }
+}
+
 fn main() {}
diff --git a/tests/ui/blocks_in_conditions_closure.rs b/tests/ui/blocks_in_conditions_closure.rs
deleted file mode 100644
index db31e4ae1a9a..000000000000
--- a/tests/ui/blocks_in_conditions_closure.rs
+++ /dev/null
@@ -1,89 +0,0 @@
-#![warn(clippy::blocks_in_conditions)]
-#![allow(
-    unused,
-    clippy::let_and_return,
-    clippy::needless_if,
-    clippy::unnecessary_literal_unwrap
-)]
-
-fn predicate<F: FnOnce(T) -> bool, T>(pfn: F, val: T) -> bool {
-    pfn(val)
-}
-
-fn pred_test() {
-    let v = 3;
-    let sky = "blue";
-    // This is a sneaky case, where the block isn't directly in the condition,
-    // but is actually inside a closure that the condition is using.
-    // The same principle applies -- add some extra expressions to make sure
-    // linter isn't confused by them.
-    if v == 3
-        && sky == "blue"
-        && predicate(
-            |x| {
-                //~^ ERROR: in an `if` condition, avoid complex blocks or closures with blocks
-                //~| NOTE: `-D clippy::blocks-in-conditions` implied by `-D warnings`
-                let target = 3;
-                x == target
-            },
-            v,
-        )
-    {}
-
-    if predicate(
-        |x| {
-            //~^ ERROR: in an `if` condition, avoid complex blocks or closures with blocks; in
-            let target = 3;
-            x == target
-        },
-        v,
-    ) {}
-}
-
-fn closure_without_block() {
-    if predicate(|x| x == 3, 6) {}
-}
-
-fn macro_in_closure() {
-    let option = Some(true);
-
-    if option.unwrap_or_else(|| unimplemented!()) {
-        unimplemented!()
-    }
-}
-
-fn closure(_: impl FnMut()) -> bool {
-    true
-}
-
-fn function_with_empty_closure() {
-    if closure(|| {}) {}
-}
-
-// issue #11814
-fn match_with_pred() {
-    let v = 3;
-    match Some(predicate(
-        |x| {
-            //~^ ERROR: in a `match` scrutinee, avoid complex blocks or closures with blocks
-            let target = 3;
-            x == target
-        },
-        v,
-    )) {
-        Some(true) => 1,
-        Some(false) => 2,
-        None => 3,
-    };
-}
-
-#[rustfmt::skip]
-fn main() {
-    let mut range = 0..10;
-    range.all(|i| {i < 10} );
-
-    let v = vec![1, 2, 3];
-    if v.into_iter().any(|x| {x == 4}) {
-        println!("contains 4!");
-    }
-}
diff --git a/tests/ui/blocks_in_conditions_closure.stderr b/tests/ui/blocks_in_conditions_closure.stderr
deleted file mode 100644
index 2faae680ec02..000000000000
--- a/tests/ui/blocks_in_conditions_closure.stderr
+++ /dev/null
@@ -1,39 +0,0 @@
-error: in an `if` condition, avoid complex blocks or closures with blocks; instead, move the block or closure higher and bind it with a `let`
-  --> tests/ui/blocks_in_conditions_closure.rs:23:17
-   |
-LL |               |x| {
-   |  _________________^
-LL | |
-LL | |
-LL | |                 let target = 3;
-LL | |                 x == target
-LL | |             },
-   | |_____________^
-   |
-   = note: `-D clippy::blocks-in-conditions` implied by `-D warnings`
-   = help: to override `-D warnings` add `#[allow(clippy::blocks_in_conditions)]`
-
-error: in an `if` condition, avoid complex blocks or closures with blocks; instead, move the block or closure higher and bind it with a `let`
-  --> tests/ui/blocks_in_conditions_closure.rs:34:13
-   |
-LL |           |x| {
-   |  _____________^
-LL | |
-LL | |             let target = 3;
-LL | |             x == target
-LL | |         },
-   | |_________^
-
-error: in a `match` scrutinee, avoid complex blocks or closures with blocks; instead, move the block or closure higher and bind it with a `let`
-  --> tests/ui/blocks_in_conditions_closure.rs:67:13
-   |
-LL |           |x| {
-   |  _____________^
-LL | |
-LL | |             let target = 3;
-LL | |             x == target
-LL | |         },
-   | |_________^
-
-error: aborting due to 3 previous errors
-

From 65af5d7b22ecd29a5aad8b6849659c9eaf62a96a Mon Sep 17 00:00:00 2001
From: Alex Macleod <alex@macleod.io>
Date: Fri, 7 Jun 2024 12:00:08 +0000
Subject: [PATCH 29/56] Remove `lazy_static` mention

---
 clippy_lints/src/non_copy_const.rs            | 32 ++++++++------
 tests/ui/crashes/ice-9445.rs                  |  2 -
 tests/ui/crashes/ice-9445.stderr              |  7 ++-
 tests/ui/crashes/mut_mut_macro.rs             | 33 --------------
 .../enums.stderr                              | 43 +++++++++----------
 .../others.stderr                             | 27 ++++++------
 .../traits.stderr                             | 26 +++++------
 7 files changed, 69 insertions(+), 101 deletions(-)
 delete mode 100644 tests/ui/crashes/mut_mut_macro.rs

diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs
index 76d9cee18aa7..464c658b2b43 100644
--- a/clippy_lints/src/non_copy_const.rs
+++ b/clippy_lints/src/non_copy_const.rs
@@ -7,7 +7,7 @@ use std::ptr;
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::in_constant;
 use clippy_utils::macros::macro_backtrace;
-use clippy_utils::ty::InteriorMut;
+use clippy_utils::ty::{implements_trait, InteriorMut};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{
@@ -18,7 +18,7 @@ use rustc_middle::mir::interpret::{ErrorHandled, EvalToValTreeResult, GlobalId};
 use rustc_middle::ty::adjustment::Adjust;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::impl_lint_pass;
-use rustc_span::{sym, InnerSpan, Span, DUMMY_SP};
+use rustc_span::{sym, Span, DUMMY_SP};
 use rustc_target::abi::VariantIdx;
 
 // FIXME: this is a correctness problem but there's no suitable
@@ -127,19 +127,19 @@ declare_clippy_lint! {
 }
 
 #[derive(Copy, Clone)]
-enum Source {
-    Item { item: Span },
+enum Source<'tcx> {
+    Item { item: Span, ty: Ty<'tcx> },
     Assoc { item: Span },
     Expr { expr: Span },
 }
 
-impl Source {
+impl Source<'_> {
     #[must_use]
     fn lint(&self) -> (&'static Lint, &'static str, Span) {
         match self {
-            Self::Item { item } | Self::Assoc { item, .. } => (
+            Self::Item { item, .. } | Self::Assoc { item, .. } => (
                 DECLARE_INTERIOR_MUTABLE_CONST,
-                "a `const` item should never be interior mutable",
+                "a `const` item should not be interior mutable",
                 *item,
             ),
             Self::Expr { expr } => (
@@ -151,16 +151,24 @@ impl Source {
     }
 }
 
-fn lint(cx: &LateContext<'_>, source: Source) {
+fn lint<'tcx>(cx: &LateContext<'tcx>, source: Source<'tcx>) {
     let (lint, msg, span) = source.lint();
     span_lint_and_then(cx, lint, span, msg, |diag| {
         if span.from_expansion() {
             return; // Don't give suggestions into macros.
         }
         match source {
-            Source::Item { .. } => {
-                let const_kw_span = span.from_inner(InnerSpan::new(0, 5));
-                diag.span_label(const_kw_span, "make this a static item (maybe with lazy_static)");
+            Source::Item { ty, .. } => {
+                let Some(sync_trait) = cx.tcx.lang_items().sync_trait() else {
+                    return;
+                };
+                if implements_trait(cx, ty, sync_trait, &[]) {
+                    diag.help("consider making this a static item");
+                } else {
+                    diag.help(
+                        "consider making this `Sync` so that it can go in a static item or using a `thread_local`",
+                    );
+                }
             },
             Source::Assoc { .. } => (),
             Source::Expr { .. } => {
@@ -311,7 +319,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst<'tcx> {
                 && self.interior_mut.is_interior_mut_ty(cx, ty)
                 && Self::is_value_unfrozen_poly(cx, body_id, ty)
             {
-                lint(cx, Source::Item { item: it.span });
+                lint(cx, Source::Item { item: it.span, ty });
             }
         }
     }
diff --git a/tests/ui/crashes/ice-9445.rs b/tests/ui/crashes/ice-9445.rs
index b6afbd33c79f..c67b22f6f8c4 100644
--- a/tests/ui/crashes/ice-9445.rs
+++ b/tests/ui/crashes/ice-9445.rs
@@ -1,5 +1,3 @@
 const UNINIT: core::mem::MaybeUninit<core::cell::Cell<&'static ()>> = core::mem::MaybeUninit::uninit();
-//~^ ERROR: a `const` item should never be interior mutable
-//~| NOTE: `-D clippy::declare-interior-mutable-const` implied by `-D warnings`
 
 fn main() {}
diff --git a/tests/ui/crashes/ice-9445.stderr b/tests/ui/crashes/ice-9445.stderr
index d6957e9549d6..76689cd6f5c2 100644
--- a/tests/ui/crashes/ice-9445.stderr
+++ b/tests/ui/crashes/ice-9445.stderr
@@ -1,11 +1,10 @@
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/crashes/ice-9445.rs:1:1
    |
 LL | const UNINIT: core::mem::MaybeUninit<core::cell::Cell<&'static ()>> = core::mem::MaybeUninit::uninit();
-   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   | |
-   | make this a static item (maybe with lazy_static)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = help: consider making this `Sync` so that it can go in a static item or using a `thread_local`
    = note: `-D clippy::declare-interior-mutable-const` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::declare_interior_mutable_const)]`
 
diff --git a/tests/ui/crashes/mut_mut_macro.rs b/tests/ui/crashes/mut_mut_macro.rs
deleted file mode 100644
index 92821b6ecbba..000000000000
--- a/tests/ui/crashes/mut_mut_macro.rs
+++ /dev/null
@@ -1,33 +0,0 @@
-#![deny(clippy::mut_mut, clippy::zero_ptr)]
-#![allow(dead_code)]
-
-// FIXME: compiletest + extern crates doesn't work together. To make this test work, it would need
-// the following three lines and the lazy_static crate.
-//
-//     #[macro_use]
-//     extern crate lazy_static;
-//     use std::collections::HashMap;
-
-/// ensure that we don't suggest `is_null` inside constants
-/// FIXME: once const fn is stable, suggest these functions again in constants
-
-const BAA: *const i32 = 0 as *const i32;
-static mut BAR: *const i32 = BAA;
-static mut FOO: *const i32 = 0 as *const i32;
-
-#[allow(unused_variables, unused_mut)]
-fn main() {
-    /*
-    lazy_static! {
-        static ref MUT_MAP : HashMap<usize, &'static str> = {
-            let mut m = HashMap::new();
-            m.insert(0, "zero");
-            m
-        };
-        static ref MUT_COUNT : usize = MUT_MAP.len();
-    }
-    assert_eq!(*MUT_COUNT, 1);
-    */
-    // FIXME: don't lint in array length, requires `check_body`
-    //let _ = [""; (42.0 < f32::NAN) as usize];
-}
diff --git a/tests/ui/declare_interior_mutable_const/enums.stderr b/tests/ui/declare_interior_mutable_const/enums.stderr
index 6c0dce6b5eaf..22329172c3af 100644
--- a/tests/ui/declare_interior_mutable_const/enums.stderr
+++ b/tests/ui/declare_interior_mutable_const/enums.stderr
@@ -1,87 +1,84 @@
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:12:1
    |
 LL | const UNFROZEN_VARIANT: OptionalCell = OptionalCell::Unfrozen(Cell::new(true));
-   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   | |
-   | make this a static item (maybe with lazy_static)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = help: consider making this `Sync` so that it can go in a static item or using a `thread_local`
    = note: `-D clippy::declare-interior-mutable-const` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::declare_interior_mutable_const)]`
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:23:1
    |
 LL | const UNFROZEN_VARIANT_FROM_FN: OptionalCell = unfrozen_variant();
-   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   | |
-   | make this a static item (maybe with lazy_static)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider making this `Sync` so that it can go in a static item or using a `thread_local`
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:45:1
    |
-LL |   const NESTED_UNFROZEN_VARIANT: NestedOutermost = NestedOutermost {
-   |   ^----
-   |   |
-   |  _make this a static item (maybe with lazy_static)
-   | |
+LL | / const NESTED_UNFROZEN_VARIANT: NestedOutermost = NestedOutermost {
 LL | |
 LL | |     outer: NestedOuter::NestedInner(NestedInner {
 LL | |         inner: NestedInnermost::Unfrozen(AtomicUsize::new(2)),
 LL | |     }),
 LL | | };
    | |__^
+   |
+   = help: consider making this a static item
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:60:5
    |
 LL |     const TO_BE_UNFROZEN_VARIANT: OptionalCell;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:61:5
    |
 LL |     const TO_BE_FROZEN_VARIANT: OptionalCell;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:64:5
    |
 LL |     const DEFAULTED_ON_UNFROZEN_VARIANT: OptionalCell = OptionalCell::Unfrozen(Cell::new(false));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:90:5
    |
 LL |     const TO_BE_UNFROZEN_VARIANT: Option<Self::ToBeUnfrozen> = Some(Self::ToBeUnfrozen::new(4));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:102:5
    |
 LL |     const UNFROZEN_VARIANT: BothOfCellAndGeneric<T> = BothOfCellAndGeneric::Unfrozen(Cell::new(std::ptr::null()));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:105:5
    |
 LL |     const GENERIC_VARIANT: BothOfCellAndGeneric<T> = BothOfCellAndGeneric::Generic(std::ptr::null());
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:111:5
    |
 LL |     const NO_ENUM: Cell<*const T> = Cell::new(std::ptr::null());
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:118:5
    |
 LL | /     const UNFROZEN_VARIANT: BothOfCellAndGeneric<Self::AssocType> =
 LL | |         BothOfCellAndGeneric::Unfrozen(Cell::new(std::ptr::null()));
    | |____________________________________________________________________^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/enums.rs:120:5
    |
 LL |     const GENERIC_VARIANT: BothOfCellAndGeneric<Self::AssocType> = BothOfCellAndGeneric::Generic(std::ptr::null());
diff --git a/tests/ui/declare_interior_mutable_const/others.stderr b/tests/ui/declare_interior_mutable_const/others.stderr
index 9dba0c952214..1f2b9561ce50 100644
--- a/tests/ui/declare_interior_mutable_const/others.stderr
+++ b/tests/ui/declare_interior_mutable_const/others.stderr
@@ -1,31 +1,30 @@
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/others.rs:9:1
    |
 LL | const ATOMIC: AtomicUsize = AtomicUsize::new(5);
-   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   | |
-   | make this a static item (maybe with lazy_static)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = help: consider making this a static item
    = note: `-D clippy::declare-interior-mutable-const` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::declare_interior_mutable_const)]`
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/others.rs:10:1
    |
 LL | const CELL: Cell<usize> = Cell::new(6);
-   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   | |
-   | make this a static item (maybe with lazy_static)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider making this `Sync` so that it can go in a static item or using a `thread_local`
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/others.rs:11:1
    |
 LL | const ATOMIC_TUPLE: ([AtomicUsize; 1], Vec<AtomicUsize>, u8) = ([ATOMIC], Vec::new(), 7);
-   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   | |
-   | make this a static item (maybe with lazy_static)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider making this a static item
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/others.rs:16:9
    |
 LL |         const $name: $ty = $e;
@@ -36,7 +35,7 @@ LL | declare_const!(_ONCE: Once = Once::new());
    |
    = note: this error originates in the macro `declare_const` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/others.rs:44:13
    |
 LL |             const _BAZ: Cell<usize> = Cell::new(0);
diff --git a/tests/ui/declare_interior_mutable_const/traits.stderr b/tests/ui/declare_interior_mutable_const/traits.stderr
index 1d1e9e2002fa..4a793d985e5e 100644
--- a/tests/ui/declare_interior_mutable_const/traits.stderr
+++ b/tests/ui/declare_interior_mutable_const/traits.stderr
@@ -1,4 +1,4 @@
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:16:5
    |
 LL |     const ATOMIC: AtomicUsize;
@@ -7,7 +7,7 @@ LL |     const ATOMIC: AtomicUsize;
    = note: `-D clippy::declare-interior-mutable-const` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::declare_interior_mutable_const)]`
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:9:9
    |
 LL |         const $name: $ty = $e;
@@ -18,67 +18,67 @@ LL |     declare_const!(ANOTHER_ATOMIC: AtomicUsize = Self::ATOMIC);
    |
    = note: this error originates in the macro `declare_const` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:44:5
    |
 LL |     const TO_BE_CONCRETE: AtomicUsize = AtomicUsize::new(11);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:69:5
    |
 LL |     const TO_BE_UNFROZEN: Self::ToBeUnfrozen = AtomicUsize::new(13);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:70:5
    |
 LL |     const WRAPPED_TO_BE_UNFROZEN: Wrapper<Self::ToBeUnfrozen> = Wrapper(AtomicUsize::new(14));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:89:5
    |
 LL |     const BOUNDED: T::ToBeBounded;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:117:5
    |
 LL |     const SELF: Self = AtomicUsize::new(17);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:118:5
    |
 LL |     const WRAPPED_SELF: Option<Self> = Some(AtomicUsize::new(21));
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:124:5
    |
 LL |     const DIRECT: Cell<T>;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:125:5
    |
 LL |     const INDIRECT: Cell<*const T>;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:129:5
    |
 LL |     const DIRECT: Cell<T> = Cell::new(T::DEFAULT);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:141:5
    |
 LL |     const ATOMIC: AtomicUsize = AtomicUsize::new(18);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: a `const` item should never be interior mutable
+error: a `const` item should not be interior mutable
   --> tests/ui/declare_interior_mutable_const/traits.rs:147:5
    |
 LL |     const BOUNDED_ASSOC_TYPE: T::ToBeBounded = AtomicUsize::new(19);

From 1781333ec75b9222446405aa0ab960f2fea004bb Mon Sep 17 00:00:00 2001
From: J-ZhengLi <lizheng135@huawei.com>
Date: Sat, 8 Jun 2024 00:06:20 +0800
Subject: [PATCH 30/56] [`match_same_arms`]: add a test case with lifetimes

---
 tests/ui/match_same_arms2.fixed  | 17 +++++++++++++++++
 tests/ui/match_same_arms2.rs     | 18 ++++++++++++++++++
 tests/ui/match_same_arms2.stderr | 18 +++++++++++++++++-
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/tests/ui/match_same_arms2.fixed b/tests/ui/match_same_arms2.fixed
index fba0cf33b3c2..09e960ddd6a9 100644
--- a/tests/ui/match_same_arms2.fixed
+++ b/tests/ui/match_same_arms2.fixed
@@ -239,3 +239,20 @@ fn main() {
         _ => false,
     };
 }
+
+// issue #8919, fixed on https://github.com/rust-lang/rust/pull/97312
+mod with_lifetime {
+    enum MaybeStaticStr<'a> {
+        Static(&'static str),
+        Borrowed(&'a str),
+    }
+
+    impl<'a> MaybeStaticStr<'a> {
+        fn get(&self) -> &'a str {
+            match *self {
+                MaybeStaticStr::Borrowed(s) | MaybeStaticStr::Static(s) => s,
+                //~^ ERROR: this match arm has an identical body to another arm
+            }
+        }
+    }
+}
diff --git a/tests/ui/match_same_arms2.rs b/tests/ui/match_same_arms2.rs
index 8a4e3b325bbf..cc7425135cc4 100644
--- a/tests/ui/match_same_arms2.rs
+++ b/tests/ui/match_same_arms2.rs
@@ -262,3 +262,21 @@ fn main() {
         _ => false,
     };
 }
+
+// issue #8919, fixed on https://github.com/rust-lang/rust/pull/97312
+mod with_lifetime {
+    enum MaybeStaticStr<'a> {
+        Static(&'static str),
+        Borrowed(&'a str),
+    }
+
+    impl<'a> MaybeStaticStr<'a> {
+        fn get(&self) -> &'a str {
+            match *self {
+                MaybeStaticStr::Static(s) => s,
+                MaybeStaticStr::Borrowed(s) => s,
+                //~^ ERROR: this match arm has an identical body to another arm
+            }
+        }
+    }
+}
diff --git a/tests/ui/match_same_arms2.stderr b/tests/ui/match_same_arms2.stderr
index 3d15176ccf99..a5d137c658b7 100644
--- a/tests/ui/match_same_arms2.stderr
+++ b/tests/ui/match_same_arms2.stderr
@@ -221,5 +221,21 @@ help: and remove this obsolete arm
 LL -         0 => cfg!(not_enable),
    |
 
-error: aborting due to 13 previous errors
+error: this match arm has an identical body to another arm
+  --> tests/ui/match_same_arms2.rs:277:17
+   |
+LL |                 MaybeStaticStr::Borrowed(s) => s,
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: try changing either arm body
+help: or try merging the arm patterns
+   |
+LL |                 MaybeStaticStr::Borrowed(s) | MaybeStaticStr::Static(s) => s,
+   |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+help: and remove this obsolete arm
+   |
+LL -                 MaybeStaticStr::Static(s) => s,
+   |
+
+error: aborting due to 14 previous errors
 

From 6fdf295664acc28ebb018e1d7b97b9e9e1e8f0ea Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Tue, 16 Apr 2024 20:25:35 +0200
Subject: [PATCH 31/56] let `qualify_min_const_fn` deal with drop checks

---
 clippy_lints/src/missing_const_for_fn.rs       | 15 +--------------
 .../ui/missing_const_for_fn/could_be_const.rs  | 18 ++++++++++++++++++
 .../missing_const_for_fn/could_be_const.stderr | 18 +++++++++++++++++-
 3 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/clippy_lints/src/missing_const_for_fn.rs b/clippy_lints/src/missing_const_for_fn.rs
index 9ba19e0a8658..fe636f27a0f0 100644
--- a/clippy_lints/src/missing_const_for_fn.rs
+++ b/clippy_lints/src/missing_const_for_fn.rs
@@ -1,7 +1,6 @@
 use clippy_config::msrvs::{self, Msrv};
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::qualify_min_const_fn::is_min_const_fn;
-use clippy_utils::ty::has_drop;
 use clippy_utils::{fn_has_unsatisfiable_preds, is_entrypoint_fn, is_from_proc_macro, trait_ref_of_method};
 use rustc_hir as hir;
 use rustc_hir::def_id::CRATE_DEF_ID;
@@ -121,10 +120,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
                 }
             },
             FnKind::Method(_, sig, ..) => {
-                if trait_ref_of_method(cx, def_id).is_some()
-                    || already_const(sig.header)
-                    || method_accepts_droppable(cx, def_id)
-                {
+                if trait_ref_of_method(cx, def_id).is_some() || already_const(sig.header) {
                     return;
                 }
             },
@@ -162,15 +158,6 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
     extract_msrv_attr!(LateContext);
 }
 
-/// Returns true if any of the method parameters is a type that implements `Drop`. The method
-/// can't be made const then, because `drop` can't be const-evaluated.
-fn method_accepts_droppable(cx: &LateContext<'_>, def_id: LocalDefId) -> bool {
-    let sig = cx.tcx.fn_sig(def_id).instantiate_identity().skip_binder();
-
-    // If any of the params are droppable, return true
-    sig.inputs().iter().any(|&ty| has_drop(cx, ty))
-}
-
 // We don't have to lint on something that's already `const`
 #[must_use]
 fn already_const(header: hir::FnHeader) -> bool {
diff --git a/tests/ui/missing_const_for_fn/could_be_const.rs b/tests/ui/missing_const_for_fn/could_be_const.rs
index 06dbbeb31c0d..8e0ede478b56 100644
--- a/tests/ui/missing_const_for_fn/could_be_const.rs
+++ b/tests/ui/missing_const_for_fn/could_be_const.rs
@@ -141,3 +141,21 @@ mod msrv {
         let _ = unsafe { bar.val };
     }
 }
+
+mod issue12677 {
+    pub struct Wrapper {
+        pub strings: Vec<String>,
+    }
+
+    impl Wrapper {
+        #[must_use]
+        pub fn new(strings: Vec<String>) -> Self {
+            Self { strings }
+        }
+
+        #[must_use]
+        pub fn empty() -> Self {
+            Self { strings: Vec::new() }
+        }
+    }
+}
diff --git a/tests/ui/missing_const_for_fn/could_be_const.stderr b/tests/ui/missing_const_for_fn/could_be_const.stderr
index b2cade305637..84ad6357b7bc 100644
--- a/tests/ui/missing_const_for_fn/could_be_const.stderr
+++ b/tests/ui/missing_const_for_fn/could_be_const.stderr
@@ -130,5 +130,21 @@ LL | |         let _ = unsafe { bar.val };
 LL | |     }
    | |_____^
 
-error: aborting due to 14 previous errors
+error: this could be a `const fn`
+  --> tests/ui/missing_const_for_fn/could_be_const.rs:152:9
+   |
+LL | /         pub fn new(strings: Vec<String>) -> Self {
+LL | |             Self { strings }
+LL | |         }
+   | |_________^
+
+error: this could be a `const fn`
+  --> tests/ui/missing_const_for_fn/could_be_const.rs:157:9
+   |
+LL | /         pub fn empty() -> Self {
+LL | |             Self { strings: Vec::new() }
+LL | |         }
+   | |_________^
+
+error: aborting due to 16 previous errors
 

From 973f318514cec40bd388f9e6f1acacc9e2bed436 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Tue, 16 Apr 2024 21:27:34 +0200
Subject: [PATCH 32/56] qualify_min_const_fn: ignore cleanup bbs

---
 clippy_utils/src/qualify_min_const_fn.rs            | 10 +++++++---
 tests/ui/missing_const_for_fn/could_be_const.rs     | 12 ++++++++++++
 tests/ui/missing_const_for_fn/could_be_const.stderr | 11 ++++++++++-
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/clippy_utils/src/qualify_min_const_fn.rs b/clippy_utils/src/qualify_min_const_fn.rs
index 81e94725a70c..42b10f69c0cd 100644
--- a/clippy_utils/src/qualify_min_const_fn.rs
+++ b/clippy_utils/src/qualify_min_const_fn.rs
@@ -40,9 +40,13 @@ pub fn is_min_const_fn<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, msrv: &Msrv)
     )?;
 
     for bb in &*body.basic_blocks {
-        check_terminator(tcx, body, bb.terminator(), msrv)?;
-        for stmt in &bb.statements {
-            check_statement(tcx, body, def_id, stmt, msrv)?;
+        // Cleanup blocks are ignored entirely by const eval, so we can too:
+        // https://github.com/rust-lang/rust/blob/1dea922ea6e74f99a0e97de5cdb8174e4dea0444/compiler/rustc_const_eval/src/transform/check_consts/check.rs#L382
+        if !bb.is_cleanup {
+            check_terminator(tcx, body, bb.terminator(), msrv)?;
+            for stmt in &bb.statements {
+                check_statement(tcx, body, def_id, stmt, msrv)?;
+            }
         }
     }
     Ok(())
diff --git a/tests/ui/missing_const_for_fn/could_be_const.rs b/tests/ui/missing_const_for_fn/could_be_const.rs
index 8e0ede478b56..58e639cc7fd1 100644
--- a/tests/ui/missing_const_for_fn/could_be_const.rs
+++ b/tests/ui/missing_const_for_fn/could_be_const.rs
@@ -158,4 +158,16 @@ mod issue12677 {
             Self { strings: Vec::new() }
         }
     }
+
+    pub struct Other {
+        pub text: String,
+        pub vec: Vec<String>,
+    }
+
+    impl Other {
+        pub fn new(text: String) -> Self {
+            let vec = Vec::new();
+            Self { text, vec }
+        }
+    }
 }
diff --git a/tests/ui/missing_const_for_fn/could_be_const.stderr b/tests/ui/missing_const_for_fn/could_be_const.stderr
index 84ad6357b7bc..1c61c3e87132 100644
--- a/tests/ui/missing_const_for_fn/could_be_const.stderr
+++ b/tests/ui/missing_const_for_fn/could_be_const.stderr
@@ -146,5 +146,14 @@ LL | |             Self { strings: Vec::new() }
 LL | |         }
    | |_________^
 
-error: aborting due to 16 previous errors
+error: this could be a `const fn`
+  --> tests/ui/missing_const_for_fn/could_be_const.rs:168:9
+   |
+LL | /         pub fn new(text: String) -> Self {
+LL | |             let vec = Vec::new();
+LL | |             Self { text, vec }
+LL | |         }
+   | |_________^
+
+error: aborting due to 17 previous errors
 

From c3d3a3f30164644d64c09812c863415f28604e80 Mon Sep 17 00:00:00 2001
From: y21 <30553356+y21@users.noreply.github.com>
Date: Fri, 7 Jun 2024 21:54:33 +0200
Subject: [PATCH 33/56] remove unnecessary const error handling in
 `missing_const_for_fn`

---
 clippy_lints/src/missing_const_for_fn.rs | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/clippy_lints/src/missing_const_for_fn.rs b/clippy_lints/src/missing_const_for_fn.rs
index fe636f27a0f0..4592324809fa 100644
--- a/clippy_lints/src/missing_const_for_fn.rs
+++ b/clippy_lints/src/missing_const_for_fn.rs
@@ -147,11 +147,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
 
         let mir = cx.tcx.optimized_mir(def_id);
 
-        if let Err((span, err)) = is_min_const_fn(cx.tcx, mir, &self.msrv) {
-            if cx.tcx.is_const_fn_raw(def_id.to_def_id()) {
-                cx.tcx.dcx().span_err(span, err);
-            }
-        } else {
+        if let Ok(()) = is_min_const_fn(cx.tcx, mir, &self.msrv) {
             span_lint(cx, MISSING_CONST_FOR_FN, span, "this could be a `const fn`");
         }
     }

From 059eaf1386e36791785275e22d00b999a5dc12f4 Mon Sep 17 00:00:00 2001
From: Jason Newcomb <jsnewcomb@pm.me>
Date: Fri, 7 Jun 2024 23:44:36 -0400
Subject: [PATCH 34/56] Fix ICE in `upper_case_acronyms`  and remove most of
 the string allocations.

---
 clippy_lints/src/upper_case_acronyms.rs | 102 ++++++++++++++----------
 tests/ui/crashes/ice-12284.rs           |  10 +++
 2 files changed, 69 insertions(+), 43 deletions(-)
 create mode 100644 tests/ui/crashes/ice-12284.rs

diff --git a/clippy_lints/src/upper_case_acronyms.rs b/clippy_lints/src/upper_case_acronyms.rs
index f376d3496461..72392f8e1f74 100644
--- a/clippy_lints/src/upper_case_acronyms.rs
+++ b/clippy_lints/src/upper_case_acronyms.rs
@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_hir_and_then;
-use itertools::Itertools;
+use core::mem::replace;
 use rustc_errors::Applicability;
 use rustc_hir::{HirId, Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
@@ -56,55 +56,71 @@ impl UpperCaseAcronyms {
 
 impl_lint_pass!(UpperCaseAcronyms => [UPPER_CASE_ACRONYMS]);
 
-fn correct_ident(ident: &str) -> String {
-    let ident = ident.chars().rev().collect::<String>();
-    let fragments = ident
-        .split_inclusive(|x: char| !x.is_ascii_lowercase())
-        .rev()
-        .map(|x| x.chars().rev().collect::<String>());
-
-    let mut ident = fragments.clone().next().unwrap();
-    for (ref prev, ref curr) in fragments.tuple_windows() {
-        if <[&String; 2]>::from((prev, curr))
-            .iter()
-            .all(|s| s.len() == 1 && s.chars().next().unwrap().is_ascii_uppercase())
-        {
-            ident.push_str(&curr.to_ascii_lowercase());
+fn contains_acronym(s: &str) -> bool {
+    let mut count = 0;
+    for c in s.chars() {
+        if c.is_ascii_uppercase() {
+            count += 1;
+            if count == 3 {
+                return true;
+            }
         } else {
-            ident.push_str(curr);
+            count = 0;
         }
     }
-    ident
+    count == 2
 }
 
 fn check_ident(cx: &LateContext<'_>, ident: &Ident, hir_id: HirId, be_aggressive: bool) {
-    let span = ident.span;
-    let ident = ident.as_str();
-    let corrected = correct_ident(ident);
-    // warn if we have pure-uppercase idents
-    // assume that two-letter words are some kind of valid abbreviation like FP for false positive
-    // (and don't warn)
-    if (ident.chars().all(|c| c.is_ascii_uppercase()) && ident.len() > 2)
-    // otherwise, warn if we have SOmeTHING lIKE THIs but only warn with the aggressive
-    // upper-case-acronyms-aggressive config option enabled
-    || (be_aggressive && ident != corrected)
+    let s = ident.as_str();
+
+    // By default, only warn for upper case identifiers with at least 3 characters.
+    let replacement = if s.len() > 2 && s.bytes().all(|c| c.is_ascii_uppercase()) {
+        let mut r = String::with_capacity(s.len());
+        let mut s = s.chars();
+        r.push(s.next().unwrap());
+        r.extend(s.map(|c| c.to_ascii_lowercase()));
+        r
+    } else if be_aggressive
+        // Only lint if the ident starts with an upper case character.
+        && let unprefixed = s.trim_start_matches('_')
+        && unprefixed.starts_with(|c: char| c.is_ascii_uppercase())
+        && contains_acronym(unprefixed)
     {
-        span_lint_hir_and_then(
-            cx,
-            UPPER_CASE_ACRONYMS,
-            hir_id,
-            span,
-            format!("name `{ident}` contains a capitalized acronym"),
-            |diag| {
-                diag.span_suggestion(
-                    span,
-                    "consider making the acronym lowercase, except the initial letter",
-                    corrected,
-                    Applicability::MaybeIncorrect,
-                );
-            },
-        );
-    }
+        let mut r = String::with_capacity(s.len());
+        let mut s = s.chars();
+        let mut prev_upper = false;
+        while let Some(c) = s.next() {
+            r.push(
+                if replace(&mut prev_upper, c.is_ascii_uppercase())
+                    && s.clone().next().map_or(true, |c| c.is_ascii_uppercase())
+                {
+                    c.to_ascii_lowercase()
+                } else {
+                    c
+                },
+            );
+        }
+        r
+    } else {
+        return;
+    };
+
+    span_lint_hir_and_then(
+        cx,
+        UPPER_CASE_ACRONYMS,
+        hir_id,
+        ident.span,
+        format!("name `{ident}` contains a capitalized acronym"),
+        |diag| {
+            diag.span_suggestion(
+                ident.span,
+                "consider making the acronym lowercase, except the initial letter",
+                replacement,
+                Applicability::MaybeIncorrect,
+            );
+        },
+    );
 }
 
 impl LateLintPass<'_> for UpperCaseAcronyms {
diff --git a/tests/ui/crashes/ice-12284.rs b/tests/ui/crashes/ice-12284.rs
new file mode 100644
index 000000000000..8d1dbface8eb
--- /dev/null
+++ b/tests/ui/crashes/ice-12284.rs
@@ -0,0 +1,10 @@
+#![allow(incomplete_features)]
+#![feature(unnamed_fields)]
+
+#[repr(C)]
+struct Foo {
+    _: struct {
+    },
+}
+
+fn main() {}

From 75e1d72093262ad955262b7cefea05a3d412de7c Mon Sep 17 00:00:00 2001
From: Jason Newcomb <jsnewcomb@pm.me>
Date: Sat, 8 Jun 2024 01:19:05 -0400
Subject: [PATCH 35/56] Normalize type aliases when checking significant drops.

---
 .../src/significant_drop_tightening.rs        | 50 +++++++------------
 1 file changed, 18 insertions(+), 32 deletions(-)

diff --git a/clippy_lints/src/significant_drop_tightening.rs b/clippy_lints/src/significant_drop_tightening.rs
index 038eb92d652b..979d6dc77aed 100644
--- a/clippy_lints/src/significant_drop_tightening.rs
+++ b/clippy_lints/src/significant_drop_tightening.rs
@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::{indent_of, snippet};
 use clippy_utils::{expr_or_init, get_attr, path_to_local, peel_hir_expr_unary};
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_errors::Applicability;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit::{walk_expr, Visitor};
@@ -12,6 +12,7 @@ use rustc_session::impl_lint_pass;
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, Span, DUMMY_SP};
 use std::borrow::Cow;
+use std::collections::hash_map::Entry;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -57,7 +58,6 @@ impl_lint_pass!(SignificantDropTightening<'_> => [SIGNIFICANT_DROP_TIGHTENING]);
 pub struct SignificantDropTightening<'tcx> {
     apas: FxIndexMap<HirId, AuxParamsAttr>,
     /// Auxiliary structure used to avoid having to verify the same type multiple times.
-    seen_types: FxHashSet<Ty<'tcx>>,
     type_cache: FxHashMap<Ty<'tcx>, bool>,
 }
 
@@ -74,7 +74,7 @@ impl<'tcx> LateLintPass<'tcx> for SignificantDropTightening<'tcx> {
         self.apas.clear();
         let initial_dummy_stmt = dummy_stmt_expr(body.value);
         let mut ap = AuxParams::new(&mut self.apas, &initial_dummy_stmt);
-        StmtsChecker::new(&mut ap, cx, &mut self.seen_types, &mut self.type_cache).visit_body(body);
+        StmtsChecker::new(&mut ap, cx, &mut self.type_cache).visit_body(body);
         for apa in ap.apas.values() {
             if apa.counter <= 1 || !apa.has_expensive_expr_after_last_attr {
                 continue;
@@ -142,28 +142,25 @@ impl<'tcx> LateLintPass<'tcx> for SignificantDropTightening<'tcx> {
 /// Checks the existence of the `#[has_significant_drop]` attribute.
 struct AttrChecker<'cx, 'others, 'tcx> {
     cx: &'cx LateContext<'tcx>,
-    seen_types: &'others mut FxHashSet<Ty<'tcx>>,
     type_cache: &'others mut FxHashMap<Ty<'tcx>, bool>,
 }
 
 impl<'cx, 'others, 'tcx> AttrChecker<'cx, 'others, 'tcx> {
-    pub(crate) fn new(
-        cx: &'cx LateContext<'tcx>,
-        seen_types: &'others mut FxHashSet<Ty<'tcx>>,
-        type_cache: &'others mut FxHashMap<Ty<'tcx>, bool>,
-    ) -> Self {
-        seen_types.clear();
-        Self {
-            cx,
-            seen_types,
-            type_cache,
-        }
+    pub(crate) fn new(cx: &'cx LateContext<'tcx>, type_cache: &'others mut FxHashMap<Ty<'tcx>, bool>) -> Self {
+        Self { cx, type_cache }
     }
 
     fn has_sig_drop_attr(&mut self, ty: Ty<'tcx>) -> bool {
-        // The borrow checker prevents us from using something fancier like or_insert_with.
-        if let Some(ty) = self.type_cache.get(&ty) {
-            return *ty;
+        let ty = self
+            .cx
+            .tcx
+            .try_normalize_erasing_regions(self.cx.param_env, ty)
+            .unwrap_or(ty);
+        match self.type_cache.entry(ty) {
+            Entry::Occupied(e) => return *e.get(),
+            Entry::Vacant(e) => {
+                e.insert(false);
+            },
         }
         let value = self.has_sig_drop_attr_uncached(ty);
         self.type_cache.insert(ty, value);
@@ -185,7 +182,7 @@ impl<'cx, 'others, 'tcx> AttrChecker<'cx, 'others, 'tcx> {
             rustc_middle::ty::Adt(a, b) => {
                 for f in a.all_fields() {
                     let ty = f.ty(self.cx.tcx, b);
-                    if !self.has_seen_ty(ty) && self.has_sig_drop_attr(ty) {
+                    if self.has_sig_drop_attr(ty) {
                         return true;
                     }
                 }
@@ -205,16 +202,11 @@ impl<'cx, 'others, 'tcx> AttrChecker<'cx, 'others, 'tcx> {
             _ => false,
         }
     }
-
-    fn has_seen_ty(&mut self, ty: Ty<'tcx>) -> bool {
-        !self.seen_types.insert(ty)
-    }
 }
 
 struct StmtsChecker<'ap, 'lc, 'others, 'stmt, 'tcx> {
     ap: &'ap mut AuxParams<'others, 'stmt, 'tcx>,
     cx: &'lc LateContext<'tcx>,
-    seen_types: &'others mut FxHashSet<Ty<'tcx>>,
     type_cache: &'others mut FxHashMap<Ty<'tcx>, bool>,
 }
 
@@ -222,15 +214,9 @@ impl<'ap, 'lc, 'others, 'stmt, 'tcx> StmtsChecker<'ap, 'lc, 'others, 'stmt, 'tcx
     fn new(
         ap: &'ap mut AuxParams<'others, 'stmt, 'tcx>,
         cx: &'lc LateContext<'tcx>,
-        seen_types: &'others mut FxHashSet<Ty<'tcx>>,
         type_cache: &'others mut FxHashMap<Ty<'tcx>, bool>,
     ) -> Self {
-        Self {
-            ap,
-            cx,
-            seen_types,
-            type_cache,
-        }
+        Self { ap, cx, type_cache }
     }
 
     fn manage_has_expensive_expr_after_last_attr(&mut self) {
@@ -288,7 +274,7 @@ impl<'ap, 'lc, 'others, 'stmt, 'tcx> Visitor<'tcx> for StmtsChecker<'ap, 'lc, 'o
             apa.counter = apa.counter.wrapping_add(1);
             apa.has_expensive_expr_after_last_attr = false;
         };
-        let mut ac = AttrChecker::new(self.cx, self.seen_types, self.type_cache);
+        let mut ac = AttrChecker::new(self.cx, self.type_cache);
         if ac.has_sig_drop_attr(self.cx.typeck_results().expr_ty(expr)) {
             if let hir::StmtKind::Let(local) = self.ap.curr_stmt.kind
                 && let hir::PatKind::Binding(_, hir_id, ident, _) = local.pat.kind

From 2855a876a76e52cee0db2df0488f22b10e228d0f Mon Sep 17 00:00:00 2001
From: Lzu Tao <taolzu@gmail.com>
Date: Sun, 26 May 2024 10:50:30 +0700
Subject: [PATCH 36/56] fix typos of author lint

---
 clippy_lints/src/utils/author.rs        | 2 +-
 tests/ui/author.stdout                  | 2 +-
 tests/ui/author/blocks.stdout           | 6 +++---
 tests/ui/author/call.stdout             | 2 +-
 tests/ui/author/if.stdout               | 2 +-
 tests/ui/author/issue_3849.stdout       | 2 +-
 tests/ui/author/loop.stdout             | 2 +-
 tests/ui/author/macro_in_closure.stdout | 2 +-
 tests/ui/author/matches.stdout          | 4 ++--
 9 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/clippy_lints/src/utils/author.rs b/clippy_lints/src/utils/author.rs
index 4448c9ae3df7..a3339cc62a9f 100644
--- a/clippy_lints/src/utils/author.rs
+++ b/clippy_lints/src/utils/author.rs
@@ -733,7 +733,7 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
         match stmt.value.kind {
             StmtKind::Let(local) => {
                 bind!(self, local);
-                kind!("Local({local})");
+                kind!("Let({local})");
                 self.option(field!(local.init), "init", |init| {
                     self.expr(init);
                 });
diff --git a/tests/ui/author.stdout b/tests/ui/author.stdout
index d448db097a7e..eed704e82fe1 100644
--- a/tests/ui/author.stdout
+++ b/tests/ui/author.stdout
@@ -1,4 +1,4 @@
-if let StmtKind::Local(local) = stmt.kind
+if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::Cast(expr, cast_ty) = init.kind
     && let TyKind::Path(ref qpath) = cast_ty.kind
diff --git a/tests/ui/author/blocks.stdout b/tests/ui/author/blocks.stdout
index 80b928dd6cb5..6bf48d5ba4ef 100644
--- a/tests/ui/author/blocks.stdout
+++ b/tests/ui/author/blocks.stdout
@@ -1,12 +1,12 @@
 if let ExprKind::Block(block, None) = expr.kind
     && block.stmts.len() == 3
-    && let StmtKind::Local(local) = block.stmts[0].kind
+    && let StmtKind::Let(local) = block.stmts[0].kind
     && let Some(init) = local.init
     && let ExprKind::Lit(ref lit) = init.kind
     && let LitKind::Int(42, LitIntType::Signed(IntTy::I32)) = lit.node
     && let PatKind::Binding(BindingMode::NONE, _, name, None) = local.pat.kind
     && name.as_str() == "x"
-    && let StmtKind::Local(local1) = block.stmts[1].kind
+    && let StmtKind::Let(local1) = block.stmts[1].kind
     && let Some(init1) = local1.init
     && let ExprKind::Lit(ref lit1) = init1.kind
     && let LitKind::Float(_, LitFloatType::Suffixed(FloatTy::F32)) = lit1.node
@@ -22,7 +22,7 @@ if let ExprKind::Block(block, None) = expr.kind
 }
 if let ExprKind::Block(block, None) = expr.kind
     && block.stmts.len() == 1
-    && let StmtKind::Local(local) = block.stmts[0].kind
+    && let StmtKind::Let(local) = block.stmts[0].kind
     && let Some(init) = local.init
     && let ExprKind::Call(func, args) = init.kind
     && let ExprKind::Path(ref qpath) = func.kind
diff --git a/tests/ui/author/call.stdout b/tests/ui/author/call.stdout
index f040f6330a64..59d4da490fe5 100644
--- a/tests/ui/author/call.stdout
+++ b/tests/ui/author/call.stdout
@@ -1,4 +1,4 @@
-if let StmtKind::Local(local) = stmt.kind
+if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::Call(func, args) = init.kind
     && let ExprKind::Path(ref qpath) = func.kind
diff --git a/tests/ui/author/if.stdout b/tests/ui/author/if.stdout
index 5d79618820d8..a85dcddd3315 100644
--- a/tests/ui/author/if.stdout
+++ b/tests/ui/author/if.stdout
@@ -1,4 +1,4 @@
-if let StmtKind::Local(local) = stmt.kind
+if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::If(cond, then, Some(else_expr)) = init.kind
     && let ExprKind::DropTemps(expr) = cond.kind
diff --git a/tests/ui/author/issue_3849.stdout b/tests/ui/author/issue_3849.stdout
index 32a3127b85a3..a5a8c0304ee4 100644
--- a/tests/ui/author/issue_3849.stdout
+++ b/tests/ui/author/issue_3849.stdout
@@ -1,4 +1,4 @@
-if let StmtKind::Local(local) = stmt.kind
+if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::Call(func, args) = init.kind
     && let ExprKind::Path(ref qpath) = func.kind
diff --git a/tests/ui/author/loop.stdout b/tests/ui/author/loop.stdout
index 631105a2238d..609d24910610 100644
--- a/tests/ui/author/loop.stdout
+++ b/tests/ui/author/loop.stdout
@@ -12,7 +12,7 @@ if let Some(higher::ForLoop { pat: pat, arg: arg, body: body, .. }) = higher::Fo
     && let LitKind::Int(10, LitIntType::Unsuffixed) = lit1.node
     && let ExprKind::Block(block, None) = body.kind
     && block.stmts.len() == 1
-    && let StmtKind::Local(local) = block.stmts[0].kind
+    && let StmtKind::Let(local) = block.stmts[0].kind
     && let Some(init) = local.init
     && let ExprKind::Path(ref qpath1) = init.kind
     && match_qpath(qpath1, &["y"])
diff --git a/tests/ui/author/macro_in_closure.stdout b/tests/ui/author/macro_in_closure.stdout
index b90c830e0307..66caf382d897 100644
--- a/tests/ui/author/macro_in_closure.stdout
+++ b/tests/ui/author/macro_in_closure.stdout
@@ -1,4 +1,4 @@
-if let StmtKind::Local(local) = stmt.kind
+if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::Closure { capture_clause: CaptureBy::Ref, fn_decl: fn_decl, body: body_id, closure_kind: ClosureKind::Closure, .. } = init.kind
     && let FnRetTy::DefaultReturn(_) = fn_decl.output
diff --git a/tests/ui/author/matches.stdout b/tests/ui/author/matches.stdout
index 30e4a9b2560a..91b3b6f6877e 100644
--- a/tests/ui/author/matches.stdout
+++ b/tests/ui/author/matches.stdout
@@ -1,4 +1,4 @@
-if let StmtKind::Local(local) = stmt.kind
+if let StmtKind::Let(local) = stmt.kind
     && let Some(init) = local.init
     && let ExprKind::Match(scrutinee, arms, MatchSource::Normal) = init.kind
     && let ExprKind::Lit(ref lit) = scrutinee.kind
@@ -16,7 +16,7 @@ if let StmtKind::Local(local) = stmt.kind
     && arms[1].guard.is_none()
     && let ExprKind::Block(block, None) = arms[1].body.kind
     && block.stmts.len() == 1
-    && let StmtKind::Local(local1) = block.stmts[0].kind
+    && let StmtKind::Let(local1) = block.stmts[0].kind
     && let Some(init1) = local1.init
     && let ExprKind::Lit(ref lit4) = init1.kind
     && let LitKind::Int(3, LitIntType::Unsuffixed) = lit4.node

From 5acc25e700363b4c3e5cddf5a32dfc5b4f28135c Mon Sep 17 00:00:00 2001
From: clubby789 <jamie@hill-daniel.co.uk>
Date: Sat, 8 Jun 2024 20:18:31 +0100
Subject: [PATCH 37/56] Update `icu4x` dependencies

---
 tests/ui/unicode.stderr | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/ui/unicode.stderr b/tests/ui/unicode.stderr
index 9c365e1097db..b004493300ee 100644
--- a/tests/ui/unicode.stderr
+++ b/tests/ui/unicode.stderr
@@ -11,7 +11,7 @@ error: invisible character detected
   --> tests/ui/unicode.rs:7:12
    |
 LL |     print!("Here >­< is a SHY, and ­another");
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider replacing the string with: `"Here >\u{AD}< is a SHY, and \u{AD}another"`
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider replacing the string with: `"Here >\u{AD}< is a SHY, and \u{AD}another"`
 
 error: invisible character detected
   --> tests/ui/unicode.rs:9:12

From 3f9c5872b9307b7674555a97493dc5223724a184 Mon Sep 17 00:00:00 2001
From: alexey semenyuk <alexsemenyuk88@gmail.com>
Date: Sun, 9 Jun 2024 17:37:05 +0500
Subject: [PATCH 38/56] Filter from first typed symbol

---
 util/gh-pages/script.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/util/gh-pages/script.js b/util/gh-pages/script.js
index 7fd779fe9a46..7cca298df8e4 100644
--- a/util/gh-pages/script.js
+++ b/util/gh-pages/script.js
@@ -397,7 +397,7 @@
             $scope.bySearch = function (lint, index, array) {
                 let searchStr = $scope.search;
                 // It can be `null` I haven't missed this value
-                if (searchStr == null || searchStr.length < 3) {
+                if (searchStr == null) {
                     return true;
                 }
                 searchStr = searchStr.toLowerCase();

From 55344c84a59412afeb6965945e24cbae7389ecab Mon Sep 17 00:00:00 2001
From: Artem Belyakov <artm.belyakov@gmail.com>
Date: Sun, 9 Jun 2024 21:01:00 +0300
Subject: [PATCH 39/56] Handle single chars with `to_string()` for
 `single_char_add_str`

---
 .../src/methods/single_char_insert_string.rs  | 42 +++++++++++++-
 .../src/methods/single_char_push_string.rs    | 41 ++++++++++++-
 tests/ui/single_char_add_str.fixed            | 10 ++++
 tests/ui/single_char_add_str.rs               | 10 ++++
 tests/ui/single_char_add_str.stderr           | 58 +++++++++++++++----
 5 files changed, 148 insertions(+), 13 deletions(-)

diff --git a/clippy_lints/src/methods/single_char_insert_string.rs b/clippy_lints/src/methods/single_char_insert_string.rs
index 20ec2b74d81e..f2af793a8691 100644
--- a/clippy_lints/src/methods/single_char_insert_string.rs
+++ b/clippy_lints/src/methods/single_char_insert_string.rs
@@ -1,8 +1,9 @@
 use super::utils::get_hint_if_single_char_arg;
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_with_applicability;
+use rustc_ast::BorrowKind;
 use rustc_errors::Applicability;
-use rustc_hir as hir;
+use rustc_hir::{self as hir, ExprKind};
 use rustc_lint::LateContext;
 
 use super::SINGLE_CHAR_ADD_STR;
@@ -25,4 +26,43 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::
             applicability,
         );
     }
+
+    if let ExprKind::AddrOf(BorrowKind::Ref, _, arg) = &args[1].kind
+        && let ExprKind::MethodCall(path_segment, method_arg, _, _) = &arg.kind
+        && path_segment.ident.as_str() == "to_string"
+        && (is_ref_char(cx, method_arg) || is_char(cx, method_arg))
+    {
+        let base_string_snippet =
+            snippet_with_applicability(cx, receiver.span.source_callsite(), "..", &mut applicability);
+        let extension_string =
+            snippet_with_applicability(cx, method_arg.span.source_callsite(), "..", &mut applicability);
+        let pos_arg = snippet_with_applicability(cx, args[0].span, "..", &mut applicability);
+        let deref_string = if is_ref_char(cx, method_arg) { "*" } else { "" };
+
+        let sugg = format!("{base_string_snippet}.insert({pos_arg}, {deref_string}{extension_string})");
+        span_lint_and_sugg(
+            cx,
+            SINGLE_CHAR_ADD_STR,
+            expr.span,
+            "calling `insert_str()` using a single-character converted to string",
+            "consider using `insert` without `to_string()`",
+            sugg,
+            applicability,
+        );
+    }
+}
+
+fn is_ref_char(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
+    if cx.typeck_results().expr_ty(expr).is_ref()
+        && let rustc_middle::ty::Ref(_, ty, _) = cx.typeck_results().expr_ty(expr).kind()
+        && ty.is_char()
+    {
+        return true;
+    }
+
+    false
+}
+
+fn is_char(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
+    cx.typeck_results().expr_ty(expr).is_char()
 }
diff --git a/clippy_lints/src/methods/single_char_push_string.rs b/clippy_lints/src/methods/single_char_push_string.rs
index 97c13825bc10..8c6e490a38ff 100644
--- a/clippy_lints/src/methods/single_char_push_string.rs
+++ b/clippy_lints/src/methods/single_char_push_string.rs
@@ -1,8 +1,9 @@
 use super::utils::get_hint_if_single_char_arg;
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_with_applicability;
+use rustc_ast::BorrowKind;
 use rustc_errors::Applicability;
-use rustc_hir as hir;
+use rustc_hir::{self as hir, ExprKind};
 use rustc_lint::LateContext;
 
 use super::SINGLE_CHAR_ADD_STR;
@@ -24,4 +25,42 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::
             applicability,
         );
     }
+
+    if let ExprKind::AddrOf(BorrowKind::Ref, _, arg) = &args[0].kind
+        && let ExprKind::MethodCall(path_segment, method_arg, _, _) = &arg.kind
+        && path_segment.ident.as_str() == "to_string"
+        && (is_ref_char(cx, method_arg) || is_char(cx, method_arg))
+    {
+        let base_string_snippet =
+            snippet_with_applicability(cx, receiver.span.source_callsite(), "..", &mut applicability);
+        let extension_string =
+            snippet_with_applicability(cx, method_arg.span.source_callsite(), "..", &mut applicability);
+        let deref_string = if is_ref_char(cx, method_arg) { "*" } else { "" };
+
+        let sugg = format!("{base_string_snippet}.push({deref_string}{extension_string})");
+        span_lint_and_sugg(
+            cx,
+            SINGLE_CHAR_ADD_STR,
+            expr.span,
+            "calling `push_str()` using a single-character converted to string",
+            "consider using `push` without `to_string()`",
+            sugg,
+            applicability,
+        );
+    }
+}
+
+fn is_ref_char(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
+    if cx.typeck_results().expr_ty(expr).is_ref()
+        && let rustc_middle::ty::Ref(_, ty, _) = cx.typeck_results().expr_ty(expr).kind()
+        && ty.is_char()
+    {
+        return true;
+    }
+
+    false
+}
+
+fn is_char(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> bool {
+    cx.typeck_results().expr_ty(expr).is_char()
 }
diff --git a/tests/ui/single_char_add_str.fixed b/tests/ui/single_char_add_str.fixed
index eafd17f53874..aef15252b1bc 100644
--- a/tests/ui/single_char_add_str.fixed
+++ b/tests/ui/single_char_add_str.fixed
@@ -21,6 +21,12 @@ fn main() {
     string.push('\u{0052}');
     string.push('a');
 
+    let c_ref = &'a';
+    string.push(*c_ref);
+    let c = 'a';
+    string.push(c);
+    string.push('a');
+
     get_string!().push('ö');
 
     // `insert_str` tests
@@ -41,5 +47,9 @@ fn main() {
     string.insert(Y, '"');
     string.insert(Y, '\'');
 
+    string.insert(0, *c_ref);
+    string.insert(0, c);
+    string.insert(0, 'a');
+
     get_string!().insert(1, '?');
 }
diff --git a/tests/ui/single_char_add_str.rs b/tests/ui/single_char_add_str.rs
index 5326c7cf24c6..7f97250dacd4 100644
--- a/tests/ui/single_char_add_str.rs
+++ b/tests/ui/single_char_add_str.rs
@@ -21,6 +21,12 @@ fn main() {
     string.push_str("\u{0052}");
     string.push_str(r##"a"##);
 
+    let c_ref = &'a';
+    string.push_str(&c_ref.to_string());
+    let c = 'a';
+    string.push_str(&c.to_string());
+    string.push_str(&'a'.to_string());
+
     get_string!().push_str("ö");
 
     // `insert_str` tests
@@ -41,5 +47,9 @@ fn main() {
     string.insert_str(Y, r##"""##);
     string.insert_str(Y, r##"'"##);
 
+    string.insert_str(0, &c_ref.to_string());
+    string.insert_str(0, &c.to_string());
+    string.insert_str(0, &'a'.to_string());
+
     get_string!().insert_str(1, "?");
 }
diff --git a/tests/ui/single_char_add_str.stderr b/tests/ui/single_char_add_str.stderr
index 89d75f20f55a..7791c67578aa 100644
--- a/tests/ui/single_char_add_str.stderr
+++ b/tests/ui/single_char_add_str.stderr
@@ -31,65 +31,101 @@ error: calling `push_str()` using a single-character string literal
 LL |     string.push_str(r##"a"##);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` with a character literal: `string.push('a')`
 
+error: calling `push_str()` using a single-character converted to string
+  --> tests/ui/single_char_add_str.rs:25:5
+   |
+LL |     string.push_str(&c_ref.to_string());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` without `to_string()`: `string.push(*c_ref)`
+
+error: calling `push_str()` using a single-character converted to string
+  --> tests/ui/single_char_add_str.rs:27:5
+   |
+LL |     string.push_str(&c.to_string());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` without `to_string()`: `string.push(c)`
+
+error: calling `push_str()` using a single-character converted to string
+  --> tests/ui/single_char_add_str.rs:28:5
+   |
+LL |     string.push_str(&'a'.to_string());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` without `to_string()`: `string.push('a')`
+
 error: calling `push_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:24:5
+  --> tests/ui/single_char_add_str.rs:30:5
    |
 LL |     get_string!().push_str("ö");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `push` with a character literal: `get_string!().push('ö')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:29:5
+  --> tests/ui/single_char_add_str.rs:35:5
    |
 LL |     string.insert_str(0, "R");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(0, 'R')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:30:5
+  --> tests/ui/single_char_add_str.rs:36:5
    |
 LL |     string.insert_str(1, "'");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(1, '\'')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:35:5
+  --> tests/ui/single_char_add_str.rs:41:5
    |
 LL |     string.insert_str(0, "\x52");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(0, '\x52')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:36:5
+  --> tests/ui/single_char_add_str.rs:42:5
    |
 LL |     string.insert_str(0, "\u{0052}");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(0, '\u{0052}')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:38:5
+  --> tests/ui/single_char_add_str.rs:44:5
    |
 LL |     string.insert_str(x, r##"a"##);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(x, 'a')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:40:5
+  --> tests/ui/single_char_add_str.rs:46:5
    |
 LL |     string.insert_str(Y, r##"a"##);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(Y, 'a')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:41:5
+  --> tests/ui/single_char_add_str.rs:47:5
    |
 LL |     string.insert_str(Y, r##"""##);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(Y, '"')`
 
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:42:5
+  --> tests/ui/single_char_add_str.rs:48:5
    |
 LL |     string.insert_str(Y, r##"'"##);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `string.insert(Y, '\'')`
 
+error: calling `insert_str()` using a single-character converted to string
+  --> tests/ui/single_char_add_str.rs:50:5
+   |
+LL |     string.insert_str(0, &c_ref.to_string());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` without `to_string()`: `string.insert(0, *c_ref)`
+
+error: calling `insert_str()` using a single-character converted to string
+  --> tests/ui/single_char_add_str.rs:51:5
+   |
+LL |     string.insert_str(0, &c.to_string());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` without `to_string()`: `string.insert(0, c)`
+
+error: calling `insert_str()` using a single-character converted to string
+  --> tests/ui/single_char_add_str.rs:52:5
+   |
+LL |     string.insert_str(0, &'a'.to_string());
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` without `to_string()`: `string.insert(0, 'a')`
+
 error: calling `insert_str()` using a single-character string literal
-  --> tests/ui/single_char_add_str.rs:44:5
+  --> tests/ui/single_char_add_str.rs:54:5
    |
 LL |     get_string!().insert_str(1, "?");
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `insert` with a character literal: `get_string!().insert(1, '?')`
 
-error: aborting due to 15 previous errors
+error: aborting due to 21 previous errors
 

From f7723cada7191fba2313d410ea5a4327a878d589 Mon Sep 17 00:00:00 2001
From: Artem Belyakov <artm.belyakov@gmail.com>
Date: Sun, 9 Jun 2024 21:23:59 +0300
Subject: [PATCH 40/56] Fix dogfood test

---
 clippy_lints/src/methods/single_char_insert_string.rs | 2 +-
 clippy_lints/src/methods/single_char_push_string.rs   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/methods/single_char_insert_string.rs b/clippy_lints/src/methods/single_char_insert_string.rs
index f2af793a8691..ba9ef9c84f9c 100644
--- a/clippy_lints/src/methods/single_char_insert_string.rs
+++ b/clippy_lints/src/methods/single_char_insert_string.rs
@@ -29,7 +29,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::
 
     if let ExprKind::AddrOf(BorrowKind::Ref, _, arg) = &args[1].kind
         && let ExprKind::MethodCall(path_segment, method_arg, _, _) = &arg.kind
-        && path_segment.ident.as_str() == "to_string"
+        && path_segment.ident.name == rustc_span::sym::to_string
         && (is_ref_char(cx, method_arg) || is_char(cx, method_arg))
     {
         let base_string_snippet =
diff --git a/clippy_lints/src/methods/single_char_push_string.rs b/clippy_lints/src/methods/single_char_push_string.rs
index 8c6e490a38ff..f00a5ab455e8 100644
--- a/clippy_lints/src/methods/single_char_push_string.rs
+++ b/clippy_lints/src/methods/single_char_push_string.rs
@@ -28,7 +28,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::
 
     if let ExprKind::AddrOf(BorrowKind::Ref, _, arg) = &args[0].kind
         && let ExprKind::MethodCall(path_segment, method_arg, _, _) = &arg.kind
-        && path_segment.ident.as_str() == "to_string"
+        && path_segment.ident.name == rustc_span::sym::to_string
         && (is_ref_char(cx, method_arg) || is_char(cx, method_arg))
     {
         let base_string_snippet =

From f7515ae9058786a61ffa30529f30575065b73450 Mon Sep 17 00:00:00 2001
From: Renato Lochetti <renato.lochetti@gmail.com>
Date: Sun, 9 Jun 2024 10:33:00 +0100
Subject: [PATCH 41/56] Don't lint indexing_slicing lints on proc macros

---
 clippy_lints/src/indexing_slicing.rs   |  6 ++--
 tests/ui/indexing_slicing_index.rs     | 20 ++++++++++++++
 tests/ui/indexing_slicing_index.stderr | 32 +++++++++++-----------
 tests/ui/indexing_slicing_slice.rs     | 21 ++++++++++++++
 tests/ui/indexing_slicing_slice.stderr | 38 +++++++++++++-------------
 5 files changed, 80 insertions(+), 37 deletions(-)

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index b13b4d145dfb..d54f2af65cde 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -2,8 +2,8 @@
 
 use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
-use clippy_utils::higher;
 use clippy_utils::ty::{deref_chain, get_adt_inherent_method};
+use clippy_utils::{higher, is_from_proc_macro};
 use rustc_ast::ast::RangeLimits;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -102,7 +102,9 @@ impl IndexingSlicing {
 
 impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if self.suppress_restriction_lint_in_const && cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+        if (self.suppress_restriction_lint_in_const && cx.tcx.hir().is_inside_const_context(expr.hir_id))
+            || is_from_proc_macro(cx, expr)
+        {
             return;
         }
 
diff --git a/tests/ui/indexing_slicing_index.rs b/tests/ui/indexing_slicing_index.rs
index 2e726141649e..2af5fcc82a9b 100644
--- a/tests/ui/indexing_slicing_index.rs
+++ b/tests/ui/indexing_slicing_index.rs
@@ -1,4 +1,5 @@
 //@compile-flags: -Zdeduplicate-diagnostics=yes
+//@aux-build: proc_macros.rs
 
 #![warn(clippy::indexing_slicing)]
 // We also check the out_of_bounds_indexing lint here, because it lints similar things and
@@ -11,6 +12,9 @@
     clippy::useless_vec
 )]
 
+extern crate proc_macros;
+use proc_macros::with_span;
+
 const ARR: [i32; 2] = [1, 2];
 const REF: &i32 = &ARR[idx()]; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
 //~^ ERROR: indexing may panic
@@ -22,6 +26,22 @@ const fn idx4() -> usize {
     4
 }
 
+with_span!(
+    span
+
+    fn dont_lint_proc_macro_array() {
+        let x = [1, 2, 3, 4];
+        let index: usize = 1;
+        x[index];
+        x[10];
+
+        let x = vec![0; 5];
+        let index: usize = 1;
+        x[index];
+        x[10];
+    }
+);
+
 fn main() {
     let x = [1, 2, 3, 4];
     let index: usize = 1;
diff --git a/tests/ui/indexing_slicing_index.stderr b/tests/ui/indexing_slicing_index.stderr
index 386f91becf14..71677584d25b 100644
--- a/tests/ui/indexing_slicing_index.stderr
+++ b/tests/ui/indexing_slicing_index.stderr
@@ -1,5 +1,5 @@
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:15:20
+  --> tests/ui/indexing_slicing_index.rs:19:20
    |
 LL | const REF: &i32 = &ARR[idx()]; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
    |                    ^^^^^^^^^^
@@ -10,19 +10,19 @@ LL | const REF: &i32 = &ARR[idx()]; // This should be linted, since `suppress-re
    = help: to override `-D warnings` add `#[allow(clippy::indexing_slicing)]`
 
 error[E0080]: evaluation of `main::{constant#3}` failed
-  --> tests/ui/indexing_slicing_index.rs:47:14
+  --> tests/ui/indexing_slicing_index.rs:67:14
    |
 LL |     const { &ARR[idx4()] };
    |              ^^^^^^^^^^^ index out of bounds: the length is 2 but the index is 4
 
 note: erroneous constant encountered
-  --> tests/ui/indexing_slicing_index.rs:47:5
+  --> tests/ui/indexing_slicing_index.rs:67:5
    |
 LL |     const { &ARR[idx4()] };
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:28:5
+  --> tests/ui/indexing_slicing_index.rs:48:5
    |
 LL |     x[index];
    |     ^^^^^^^^
@@ -30,7 +30,7 @@ LL |     x[index];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: index is out of bounds
-  --> tests/ui/indexing_slicing_index.rs:31:5
+  --> tests/ui/indexing_slicing_index.rs:51:5
    |
 LL |     x[4];
    |     ^^^^
@@ -39,13 +39,13 @@ LL |     x[4];
    = help: to override `-D warnings` add `#[allow(clippy::out_of_bounds_indexing)]`
 
 error: index is out of bounds
-  --> tests/ui/indexing_slicing_index.rs:33:5
+  --> tests/ui/indexing_slicing_index.rs:53:5
    |
 LL |     x[1 << 3];
    |     ^^^^^^^^^
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:44:14
+  --> tests/ui/indexing_slicing_index.rs:64:14
    |
 LL |     const { &ARR[idx()] };
    |              ^^^^^^^^^^
@@ -54,7 +54,7 @@ LL |     const { &ARR[idx()] };
    = note: the suggestion might not be applicable in constant blocks
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:47:14
+  --> tests/ui/indexing_slicing_index.rs:67:14
    |
 LL |     const { &ARR[idx4()] };
    |              ^^^^^^^^^^^
@@ -63,13 +63,13 @@ LL |     const { &ARR[idx4()] };
    = note: the suggestion might not be applicable in constant blocks
 
 error: index is out of bounds
-  --> tests/ui/indexing_slicing_index.rs:54:5
+  --> tests/ui/indexing_slicing_index.rs:74:5
    |
 LL |     y[4];
    |     ^^^^
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:57:5
+  --> tests/ui/indexing_slicing_index.rs:77:5
    |
 LL |     v[0];
    |     ^^^^
@@ -77,7 +77,7 @@ LL |     v[0];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:59:5
+  --> tests/ui/indexing_slicing_index.rs:79:5
    |
 LL |     v[10];
    |     ^^^^^
@@ -85,7 +85,7 @@ LL |     v[10];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:61:5
+  --> tests/ui/indexing_slicing_index.rs:81:5
    |
 LL |     v[1 << 3];
    |     ^^^^^^^^^
@@ -93,13 +93,13 @@ LL |     v[1 << 3];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: index is out of bounds
-  --> tests/ui/indexing_slicing_index.rs:69:5
+  --> tests/ui/indexing_slicing_index.rs:89:5
    |
 LL |     x[N];
    |     ^^^^
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:72:5
+  --> tests/ui/indexing_slicing_index.rs:92:5
    |
 LL |     v[N];
    |     ^^^^
@@ -107,7 +107,7 @@ LL |     v[N];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_index.rs:74:5
+  --> tests/ui/indexing_slicing_index.rs:94:5
    |
 LL |     v[M];
    |     ^^^^
@@ -115,7 +115,7 @@ LL |     v[M];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: index is out of bounds
-  --> tests/ui/indexing_slicing_index.rs:78:13
+  --> tests/ui/indexing_slicing_index.rs:98:13
    |
 LL |     let _ = x[4];
    |             ^^^^
diff --git a/tests/ui/indexing_slicing_slice.rs b/tests/ui/indexing_slicing_slice.rs
index 69291acd9c77..f37bcc4aa0ca 100644
--- a/tests/ui/indexing_slicing_slice.rs
+++ b/tests/ui/indexing_slicing_slice.rs
@@ -1,3 +1,5 @@
+//@aux-build: proc_macros.rs
+
 #![warn(clippy::indexing_slicing)]
 // We also check the out_of_bounds_indexing lint here, because it lints similar things and
 // we want to avoid false positives.
@@ -11,6 +13,9 @@
 )]
 #![warn(clippy::indexing_slicing)]
 
+extern crate proc_macros;
+use proc_macros::with_span;
+
 use std::ops::Index;
 
 struct BoolMap<T> {
@@ -86,6 +91,22 @@ impl<T> Index<i32> for Z<T> {
     }
 }
 
+with_span!(
+    span
+
+    fn dont_lint_proc_macro() {
+        let x = [1, 2, 3, 4];
+        let index: usize = 1;
+        &x[index..];
+        &x[..10];
+
+        let x = vec![0; 5];
+        let index: usize = 1;
+        &x[index..];
+        &x[..10];
+    }
+);
+
 fn main() {
     let x = [1, 2, 3, 4];
     let index: usize = 1;
diff --git a/tests/ui/indexing_slicing_slice.stderr b/tests/ui/indexing_slicing_slice.stderr
index a7da3fe3faa7..1e72506746ec 100644
--- a/tests/ui/indexing_slicing_slice.stderr
+++ b/tests/ui/indexing_slicing_slice.stderr
@@ -1,5 +1,5 @@
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:94:6
+  --> tests/ui/indexing_slicing_slice.rs:115:6
    |
 LL |     &x[index..];
    |      ^^^^^^^^^^
@@ -9,7 +9,7 @@ LL |     &x[index..];
    = help: to override `-D warnings` add `#[allow(clippy::indexing_slicing)]`
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:96:6
+  --> tests/ui/indexing_slicing_slice.rs:117:6
    |
 LL |     &x[..index];
    |      ^^^^^^^^^^
@@ -17,7 +17,7 @@ LL |     &x[..index];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:98:6
+  --> tests/ui/indexing_slicing_slice.rs:119:6
    |
 LL |     &x[index_from..index_to];
    |      ^^^^^^^^^^^^^^^^^^^^^^^
@@ -25,7 +25,7 @@ LL |     &x[index_from..index_to];
    = help: consider using `.get(n..m)` or `.get_mut(n..m)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:100:6
+  --> tests/ui/indexing_slicing_slice.rs:121:6
    |
 LL |     &x[index_from..][..index_to];
    |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -33,7 +33,7 @@ LL |     &x[index_from..][..index_to];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:100:6
+  --> tests/ui/indexing_slicing_slice.rs:121:6
    |
 LL |     &x[index_from..][..index_to];
    |      ^^^^^^^^^^^^^^^
@@ -41,7 +41,7 @@ LL |     &x[index_from..][..index_to];
    = help: consider using `.get(n..)` or .get_mut(n..)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:103:6
+  --> tests/ui/indexing_slicing_slice.rs:124:6
    |
 LL |     &x[5..][..10];
    |      ^^^^^^^^^^^^
@@ -49,7 +49,7 @@ LL |     &x[5..][..10];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
-  --> tests/ui/indexing_slicing_slice.rs:103:8
+  --> tests/ui/indexing_slicing_slice.rs:124:8
    |
 LL |     &x[5..][..10];
    |        ^
@@ -58,7 +58,7 @@ LL |     &x[5..][..10];
    = help: to override `-D warnings` add `#[allow(clippy::out_of_bounds_indexing)]`
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:107:6
+  --> tests/ui/indexing_slicing_slice.rs:128:6
    |
 LL |     &x[0..][..3];
    |      ^^^^^^^^^^^
@@ -66,7 +66,7 @@ LL |     &x[0..][..3];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:109:6
+  --> tests/ui/indexing_slicing_slice.rs:130:6
    |
 LL |     &x[1..][..5];
    |      ^^^^^^^^^^^
@@ -74,19 +74,19 @@ LL |     &x[1..][..5];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
-  --> tests/ui/indexing_slicing_slice.rs:117:12
+  --> tests/ui/indexing_slicing_slice.rs:138:12
    |
 LL |     &y[0..=4];
    |            ^
 
 error: range is out of bounds
-  --> tests/ui/indexing_slicing_slice.rs:119:11
+  --> tests/ui/indexing_slicing_slice.rs:140:11
    |
 LL |     &y[..=4];
    |           ^
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:125:6
+  --> tests/ui/indexing_slicing_slice.rs:146:6
    |
 LL |     &v[10..100];
    |      ^^^^^^^^^^
@@ -94,7 +94,7 @@ LL |     &v[10..100];
    = help: consider using `.get(n..m)` or `.get_mut(n..m)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:127:6
+  --> tests/ui/indexing_slicing_slice.rs:148:6
    |
 LL |     &x[10..][..100];
    |      ^^^^^^^^^^^^^^
@@ -102,13 +102,13 @@ LL |     &x[10..][..100];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
-  --> tests/ui/indexing_slicing_slice.rs:127:8
+  --> tests/ui/indexing_slicing_slice.rs:148:8
    |
 LL |     &x[10..][..100];
    |        ^^
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:130:6
+  --> tests/ui/indexing_slicing_slice.rs:151:6
    |
 LL |     &v[10..];
    |      ^^^^^^^
@@ -116,7 +116,7 @@ LL |     &v[10..];
    = help: consider using `.get(n..)` or .get_mut(n..)` instead
 
 error: slicing may panic
-  --> tests/ui/indexing_slicing_slice.rs:132:6
+  --> tests/ui/indexing_slicing_slice.rs:153:6
    |
 LL |     &v[..100];
    |      ^^^^^^^^
@@ -124,7 +124,7 @@ LL |     &v[..100];
    = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_slice.rs:150:5
+  --> tests/ui/indexing_slicing_slice.rs:171:5
    |
 LL |     map_with_get[true];
    |     ^^^^^^^^^^^^^^^^^^
@@ -132,7 +132,7 @@ LL |     map_with_get[true];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_slice.rs:153:5
+  --> tests/ui/indexing_slicing_slice.rs:174:5
    |
 LL |     s[0];
    |     ^^^^
@@ -140,7 +140,7 @@ LL |     s[0];
    = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
-  --> tests/ui/indexing_slicing_slice.rs:156:5
+  --> tests/ui/indexing_slicing_slice.rs:177:5
    |
 LL |     y[0];
    |     ^^^^

From 8c1f953772a025dcfec6dbd36544e415842ad1d1 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 8 Jun 2024 16:13:45 +0200
Subject: [PATCH 42/56] ScalarInt: size mismatches are a bug, do not delay the
 panic

---
 clippy_lints/src/large_const_arrays.rs       |  2 +-
 clippy_lints/src/large_stack_arrays.rs       |  2 +-
 clippy_lints/src/non_copy_const.rs           |  2 +-
 clippy_lints/src/zero_repeat_side_effects.rs |  3 +--
 clippy_utils/src/consts.rs                   |  4 ++--
 clippy_utils/src/ty.rs                       | 20 +++-----------------
 6 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/clippy_lints/src/large_const_arrays.rs b/clippy_lints/src/large_const_arrays.rs
index 77d05020c828..7f8197c0cc01 100644
--- a/clippy_lints/src/large_const_arrays.rs
+++ b/clippy_lints/src/large_const_arrays.rs
@@ -55,7 +55,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeConstArrays {
             && let ty = cx.tcx.type_of(item.owner_id).instantiate_identity()
             && let ty::Array(element_type, cst) = ty.kind()
             && let ConstKind::Value(_, ty::ValTree::Leaf(element_count)) = cst.kind()
-            && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx)
+            && let element_count = element_count.to_target_usize(cx.tcx)
             && let Ok(element_size) = cx.layout_of(*element_type).map(|l| l.size.bytes())
             && self.maximum_allowed_size < u128::from(element_count) * u128::from(element_size)
         {
diff --git a/clippy_lints/src/large_stack_arrays.rs b/clippy_lints/src/large_stack_arrays.rs
index f0f3f53647b9..c9bfc9c85d95 100644
--- a/clippy_lints/src/large_stack_arrays.rs
+++ b/clippy_lints/src/large_stack_arrays.rs
@@ -65,7 +65,7 @@ impl<'tcx> LateLintPass<'tcx> for LargeStackArrays {
             && !self.is_from_vec_macro(cx, expr.span)
             && let ty::Array(element_type, cst) = cx.typeck_results().expr_ty(expr).kind()
             && let ConstKind::Value(_, ty::ValTree::Leaf(element_count)) = cst.kind()
-            && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx)
+            && let element_count = element_count.to_target_usize(cx.tcx)
             && let Ok(element_size) = cx.layout_of(*element_type).map(|l| l.size.bytes())
             && !cx.tcx.hir().parent_iter(expr.hir_id).any(|(_, node)| {
                 matches!(
diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs
index 76d9cee18aa7..20a97645af95 100644
--- a/clippy_lints/src/non_copy_const.rs
+++ b/clippy_lints/src/non_copy_const.rs
@@ -199,7 +199,7 @@ impl<'tcx> NonCopyConst<'tcx> {
                 .any(|field| Self::is_value_unfrozen_raw_inner(cx, *field, ty)),
             ty::Adt(def, args) if def.is_enum() => {
                 let (&variant_index, fields) = val.unwrap_branch().split_first().unwrap();
-                let variant_index = VariantIdx::from_u32(variant_index.unwrap_leaf().try_to_u32().ok().unwrap());
+                let variant_index = VariantIdx::from_u32(variant_index.unwrap_leaf().to_u32());
                 fields
                     .iter()
                     .copied()
diff --git a/clippy_lints/src/zero_repeat_side_effects.rs b/clippy_lints/src/zero_repeat_side_effects.rs
index 848b49130dc2..8796b8f61d16 100644
--- a/clippy_lints/src/zero_repeat_side_effects.rs
+++ b/clippy_lints/src/zero_repeat_side_effects.rs
@@ -56,8 +56,7 @@ impl LateLintPass<'_> for ZeroRepeatSideEffects {
         } else if let ExprKind::Repeat(inner_expr, _) = expr.kind
             && let ty::Array(_, cst) = cx.typeck_results().expr_ty(expr).kind()
             && let ConstKind::Value(_, ty::ValTree::Leaf(element_count)) = cst.kind()
-            && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx)
-            && element_count == 0
+            && element_count.to_target_usize(cx.tcx) == 0
         {
             inner_check(cx, expr, inner_expr, false);
         }
diff --git a/clippy_utils/src/consts.rs b/clippy_utils/src/consts.rs
index 5c9cad2b45d4..e9e1aa7e4453 100644
--- a/clippy_utils/src/consts.rs
+++ b/clippy_utils/src/consts.rs
@@ -810,14 +810,14 @@ pub fn mir_to_const<'tcx>(lcx: &LateContext<'tcx>, result: mir::Const<'tcx>) ->
         (ConstValue::Scalar(Scalar::Int(int)), _) => match result.ty().kind() {
             ty::Adt(adt_def, _) if adt_def.is_struct() => Some(Constant::Adt(result)),
             ty::Bool => Some(Constant::Bool(int == ScalarInt::TRUE)),
-            ty::Uint(_) | ty::Int(_) => Some(Constant::Int(int.assert_bits(int.size()))),
+            ty::Uint(_) | ty::Int(_) => Some(Constant::Int(int.to_bits(int.size()))),
             ty::Float(FloatTy::F32) => Some(Constant::F32(f32::from_bits(
                 int.try_into().expect("invalid f32 bit representation"),
             ))),
             ty::Float(FloatTy::F64) => Some(Constant::F64(f64::from_bits(
                 int.try_into().expect("invalid f64 bit representation"),
             ))),
-            ty::RawPtr(_, _) => Some(Constant::RawPtr(int.assert_bits(int.size()))),
+            ty::RawPtr(_, _) => Some(Constant::RawPtr(int.to_bits(int.size()))),
             _ => None,
         },
         (_, ty::Ref(_, inner_ty, _)) if matches!(inner_ty.kind(), ty::Str) => {
diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs
index f0dac6f5d9c4..6e5626297c95 100644
--- a/clippy_utils/src/ty.rs
+++ b/clippy_utils/src/ty.rs
@@ -23,7 +23,7 @@ use rustc_middle::ty::{
 };
 use rustc_span::symbol::Ident;
 use rustc_span::{sym, Span, Symbol, DUMMY_SP};
-use rustc_target::abi::{Size, VariantIdx};
+use rustc_target::abi::VariantIdx;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
 use rustc_trait_selection::traits::{Obligation, ObligationCause};
@@ -865,22 +865,8 @@ impl core::ops::Add<u32> for EnumValue {
 pub fn read_explicit_enum_value(tcx: TyCtxt<'_>, id: DefId) -> Option<EnumValue> {
     if let Ok(ConstValue::Scalar(Scalar::Int(value))) = tcx.const_eval_poly(id) {
         match tcx.type_of(id).instantiate_identity().kind() {
-            ty::Int(_) => Some(EnumValue::Signed(match value.size().bytes() {
-                1 => i128::from(value.assert_bits(Size::from_bytes(1)) as u8 as i8),
-                2 => i128::from(value.assert_bits(Size::from_bytes(2)) as u16 as i16),
-                4 => i128::from(value.assert_bits(Size::from_bytes(4)) as u32 as i32),
-                8 => i128::from(value.assert_bits(Size::from_bytes(8)) as u64 as i64),
-                16 => value.assert_bits(Size::from_bytes(16)) as i128,
-                _ => return None,
-            })),
-            ty::Uint(_) => Some(EnumValue::Unsigned(match value.size().bytes() {
-                1 => value.assert_bits(Size::from_bytes(1)),
-                2 => value.assert_bits(Size::from_bytes(2)),
-                4 => value.assert_bits(Size::from_bytes(4)),
-                8 => value.assert_bits(Size::from_bytes(8)),
-                16 => value.assert_bits(Size::from_bytes(16)),
-                _ => return None,
-            })),
+            ty::Int(_) => Some(EnumValue::Signed(value.to_int(value.size()))),
+            ty::Uint(_) => Some(EnumValue::Unsigned(value.to_uint(value.size()))),
             _ => None,
         }
     } else {

From c86b19f1ef262eeb1992a91879b38ffbed07a1a7 Mon Sep 17 00:00:00 2001
From: AurelienFT <aurelien.foucault@epitech.eu>
Date: Tue, 11 Jun 2024 21:56:14 +0200
Subject: [PATCH 43/56] Add lint to check manual pattern char comparison and
 merge its code with single_char_pattern lint

---
 CHANGELOG.md                                  |   1 +
 clippy_lints/src/declared_lints.rs            |   3 +-
 clippy_lints/src/float_literal.rs             |   2 +-
 clippy_lints/src/lib.rs                       |   2 +
 clippy_lints/src/methods/mod.rs               |  35 ---
 .../src/methods/path_buf_push_overwrite.rs    |   2 +-
 .../src/methods/single_char_insert_string.rs  |   5 +-
 .../src/methods/single_char_pattern.rs        |  64 -----
 .../src/methods/single_char_push_string.rs    |   5 +-
 clippy_lints/src/methods/utils.rs             |  45 ----
 .../src/misc_early/zero_prefixed_literal.rs   |   4 +-
 clippy_lints/src/string_patterns.rs           | 227 ++++++++++++++++++
 clippy_utils/src/source.rs                    |  45 ++++
 tests/ui/manual_pattern_char_comparison.fixed |  49 ++++
 tests/ui/manual_pattern_char_comparison.rs    |  49 ++++
 .../ui/manual_pattern_char_comparison.stderr  |  59 +++++
 tests/ui/search_is_some.rs                    |   1 +
 tests/ui/search_is_some.stderr                |  16 +-
 18 files changed, 451 insertions(+), 163 deletions(-)
 delete mode 100644 clippy_lints/src/methods/single_char_pattern.rs
 create mode 100644 clippy_lints/src/string_patterns.rs
 create mode 100644 tests/ui/manual_pattern_char_comparison.fixed
 create mode 100644 tests/ui/manual_pattern_char_comparison.rs
 create mode 100644 tests/ui/manual_pattern_char_comparison.stderr

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 711b7fb79141..d7bcd7a19687 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5532,6 +5532,7 @@ Released 2018-09-13
 [`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_pattern_char_comparison`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_pattern_char_comparison
 [`manual_range_contains`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains
 [`manual_range_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_patterns
 [`manual_rem_euclid`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_rem_euclid
diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs
index a9f2dd4499a3..7e43a99e9f24 100644
--- a/clippy_lints/src/declared_lints.rs
+++ b/clippy_lints/src/declared_lints.rs
@@ -448,7 +448,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::methods::SEEK_TO_START_INSTEAD_OF_REWIND_INFO,
     crate::methods::SHOULD_IMPLEMENT_TRAIT_INFO,
     crate::methods::SINGLE_CHAR_ADD_STR_INFO,
-    crate::methods::SINGLE_CHAR_PATTERN_INFO,
     crate::methods::SKIP_WHILE_NEXT_INFO,
     crate::methods::STABLE_SORT_PRIMITIVE_INFO,
     crate::methods::STRING_EXTEND_CHARS_INFO,
@@ -656,6 +655,8 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::std_instead_of_core::ALLOC_INSTEAD_OF_CORE_INFO,
     crate::std_instead_of_core::STD_INSTEAD_OF_ALLOC_INFO,
     crate::std_instead_of_core::STD_INSTEAD_OF_CORE_INFO,
+    crate::string_patterns::MANUAL_PATTERN_CHAR_COMPARISON_INFO,
+    crate::string_patterns::SINGLE_CHAR_PATTERN_INFO,
     crate::strings::STRING_ADD_INFO,
     crate::strings::STRING_ADD_ASSIGN_INFO,
     crate::strings::STRING_FROM_UTF8_AS_BYTES_INFO,
diff --git a/clippy_lints/src/float_literal.rs b/clippy_lints/src/float_literal.rs
index 4ec9bd757ff4..4d301daabe4c 100644
--- a/clippy_lints/src/float_literal.rs
+++ b/clippy_lints/src/float_literal.rs
@@ -103,7 +103,7 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
                 return;
             }
 
-            if is_whole && !sym_str.contains(|c| c == 'e' || c == 'E') {
+            if is_whole && !sym_str.contains(['e', 'E']) {
                 // Normalize the literal by stripping the fractional portion
                 if sym_str.split('.').next().unwrap() != float_str {
                     // If the type suffix is missing the suggestion would be
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 6946c2986f48..c65581d5203e 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -326,6 +326,7 @@ mod size_of_in_element_count;
 mod size_of_ref;
 mod slow_vector_initialization;
 mod std_instead_of_core;
+mod string_patterns;
 mod strings;
 mod strlen_on_c_strings;
 mod suspicious_operation_groupings;
@@ -1167,6 +1168,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
             ..Default::default()
         })
     });
+    store.register_late_pass(|_| Box::new(string_patterns::StringPatterns));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index c3699d6341a0..6200716afbe9 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -94,7 +94,6 @@ mod seek_from_current;
 mod seek_to_start_instead_of_rewind;
 mod single_char_add_str;
 mod single_char_insert_string;
-mod single_char_pattern;
 mod single_char_push_string;
 mod skip_while_next;
 mod stable_sort_primitive;
@@ -1141,38 +1140,6 @@ declare_clippy_lint! {
     "not returning type containing `Self` in a `new` method"
 }
 
-declare_clippy_lint! {
-    /// ### What it does
-    /// Checks for string methods that receive a single-character
-    /// `str` as an argument, e.g., `_.split("x")`.
-    ///
-    /// ### Why is this bad?
-    /// While this can make a perf difference on some systems,
-    /// benchmarks have proven inconclusive. But at least using a
-    /// char literal makes it clear that we are looking at a single
-    /// character.
-    ///
-    /// ### Known problems
-    /// Does not catch multi-byte unicode characters. This is by
-    /// design, on many machines, splitting by a non-ascii char is
-    /// actually slower. Please do your own measurements instead of
-    /// relying solely on the results of this lint.
-    ///
-    /// ### Example
-    /// ```rust,ignore
-    /// _.split("x");
-    /// ```
-    ///
-    /// Use instead:
-    /// ```rust,ignore
-    /// _.split('x');
-    /// ```
-    #[clippy::version = "pre 1.29.0"]
-    pub SINGLE_CHAR_PATTERN,
-    pedantic,
-    "using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
-}
-
 declare_clippy_lint! {
     /// ### What it does
     /// Checks for calling `.step_by(0)` on iterators which panics.
@@ -4169,7 +4136,6 @@ impl_lint_pass!(Methods => [
     FLAT_MAP_OPTION,
     INEFFICIENT_TO_STRING,
     NEW_RET_NO_SELF,
-    SINGLE_CHAR_PATTERN,
     SINGLE_CHAR_ADD_STR,
     SEARCH_IS_SOME,
     FILTER_NEXT,
@@ -4324,7 +4290,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                 inefficient_to_string::check(cx, expr, method_call.ident.name, receiver, args);
                 single_char_add_str::check(cx, expr, receiver, args);
                 into_iter_on_ref::check(cx, expr, method_span, method_call.ident.name, receiver);
-                single_char_pattern::check(cx, expr, method_call.ident.name, receiver, args);
                 unnecessary_to_owned::check(cx, expr, method_call.ident.name, receiver, args, &self.msrv);
             },
             ExprKind::Binary(op, lhs, rhs) if op.node == hir::BinOpKind::Eq || op.node == hir::BinOpKind::Ne => {
diff --git a/clippy_lints/src/methods/path_buf_push_overwrite.rs b/clippy_lints/src/methods/path_buf_push_overwrite.rs
index 04a27cc98f3c..2d3007e50b81 100644
--- a/clippy_lints/src/methods/path_buf_push_overwrite.rs
+++ b/clippy_lints/src/methods/path_buf_push_overwrite.rs
@@ -27,7 +27,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, arg: &'t
             lit.span,
             "calling `push` with '/' or '\\' (file system root) will overwrite the previous path definition",
             "try",
-            format!("\"{}\"", pushed_path_lit.trim_start_matches(|c| c == '/' || c == '\\')),
+            format!("\"{}\"", pushed_path_lit.trim_start_matches(['/', '\\'])),
             Applicability::MachineApplicable,
         );
     }
diff --git a/clippy_lints/src/methods/single_char_insert_string.rs b/clippy_lints/src/methods/single_char_insert_string.rs
index ba9ef9c84f9c..e2f76ac114c6 100644
--- a/clippy_lints/src/methods/single_char_insert_string.rs
+++ b/clippy_lints/src/methods/single_char_insert_string.rs
@@ -1,6 +1,5 @@
-use super::utils::get_hint_if_single_char_arg;
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::source::{snippet_with_applicability, str_literal_to_char_literal};
 use rustc_ast::BorrowKind;
 use rustc_errors::Applicability;
 use rustc_hir::{self as hir, ExprKind};
@@ -11,7 +10,7 @@ use super::SINGLE_CHAR_ADD_STR;
 /// lint for length-1 `str`s as argument for `insert_str`
 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
     let mut applicability = Applicability::MachineApplicable;
-    if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[1], &mut applicability, false) {
+    if let Some(extension_string) = str_literal_to_char_literal(cx, &args[1], &mut applicability, false) {
         let base_string_snippet =
             snippet_with_applicability(cx, receiver.span.source_callsite(), "_", &mut applicability);
         let pos_arg = snippet_with_applicability(cx, args[0].span, "..", &mut applicability);
diff --git a/clippy_lints/src/methods/single_char_pattern.rs b/clippy_lints/src/methods/single_char_pattern.rs
deleted file mode 100644
index 982a7901c453..000000000000
--- a/clippy_lints/src/methods/single_char_pattern.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-use super::utils::get_hint_if_single_char_arg;
-use clippy_utils::diagnostics::span_lint_and_sugg;
-use rustc_errors::Applicability;
-use rustc_hir as hir;
-use rustc_lint::LateContext;
-use rustc_middle::ty;
-use rustc_span::symbol::Symbol;
-
-use super::SINGLE_CHAR_PATTERN;
-
-const PATTERN_METHODS: [(&str, usize); 22] = [
-    ("contains", 0),
-    ("starts_with", 0),
-    ("ends_with", 0),
-    ("find", 0),
-    ("rfind", 0),
-    ("split", 0),
-    ("split_inclusive", 0),
-    ("rsplit", 0),
-    ("split_terminator", 0),
-    ("rsplit_terminator", 0),
-    ("splitn", 1),
-    ("rsplitn", 1),
-    ("split_once", 0),
-    ("rsplit_once", 0),
-    ("matches", 0),
-    ("rmatches", 0),
-    ("match_indices", 0),
-    ("rmatch_indices", 0),
-    ("trim_start_matches", 0),
-    ("trim_end_matches", 0),
-    ("replace", 0),
-    ("replacen", 0),
-];
-
-/// lint for length-1 `str`s for methods in `PATTERN_METHODS`
-pub(super) fn check(
-    cx: &LateContext<'_>,
-    _expr: &hir::Expr<'_>,
-    method_name: Symbol,
-    receiver: &hir::Expr<'_>,
-    args: &[hir::Expr<'_>],
-) {
-    for &(method, pos) in &PATTERN_METHODS {
-        if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(receiver).kind()
-            && ty.is_str()
-            && method_name.as_str() == method
-            && args.len() > pos
-            && let arg = &args[pos]
-            && let mut applicability = Applicability::MachineApplicable
-            && let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability, true)
-        {
-            span_lint_and_sugg(
-                cx,
-                SINGLE_CHAR_PATTERN,
-                arg.span,
-                "single-character string constant used as pattern",
-                "consider using a `char`",
-                hint,
-                applicability,
-            );
-        }
-    }
-}
diff --git a/clippy_lints/src/methods/single_char_push_string.rs b/clippy_lints/src/methods/single_char_push_string.rs
index f00a5ab455e8..4ae8634305da 100644
--- a/clippy_lints/src/methods/single_char_push_string.rs
+++ b/clippy_lints/src/methods/single_char_push_string.rs
@@ -1,6 +1,5 @@
-use super::utils::get_hint_if_single_char_arg;
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::source::{snippet_with_applicability, str_literal_to_char_literal};
 use rustc_ast::BorrowKind;
 use rustc_errors::Applicability;
 use rustc_hir::{self as hir, ExprKind};
@@ -11,7 +10,7 @@ use super::SINGLE_CHAR_ADD_STR;
 /// lint for length-1 `str`s as argument for `push_str`
 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, receiver: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
     let mut applicability = Applicability::MachineApplicable;
-    if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[0], &mut applicability, false) {
+    if let Some(extension_string) = str_literal_to_char_literal(cx, &args[0], &mut applicability, false) {
         let base_string_snippet =
             snippet_with_applicability(cx, receiver.span.source_callsite(), "..", &mut applicability);
         let sugg = format!("{base_string_snippet}.push({extension_string})");
diff --git a/clippy_lints/src/methods/utils.rs b/clippy_lints/src/methods/utils.rs
index 5d58c73f8b20..0d2b0a313176 100644
--- a/clippy_lints/src/methods/utils.rs
+++ b/clippy_lints/src/methods/utils.rs
@@ -1,8 +1,5 @@
-use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::ty::is_type_diagnostic_item;
 use clippy_utils::{get_parent_expr, path_to_local_id, usage};
-use rustc_ast::ast;
-use rustc_errors::Applicability;
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{BorrowKind, Expr, ExprKind, HirId, Mutability, Pat, QPath, Stmt, StmtKind};
 use rustc_lint::LateContext;
@@ -49,48 +46,6 @@ pub(super) fn derefs_to_slice<'tcx>(
     }
 }
 
-pub(super) fn get_hint_if_single_char_arg(
-    cx: &LateContext<'_>,
-    arg: &Expr<'_>,
-    applicability: &mut Applicability,
-    ascii_only: bool,
-) -> Option<String> {
-    if let ExprKind::Lit(lit) = &arg.kind
-        && let ast::LitKind::Str(r, style) = lit.node
-        && let string = r.as_str()
-        && let len = if ascii_only {
-            string.len()
-        } else {
-            string.chars().count()
-        }
-        && len == 1
-    {
-        let snip = snippet_with_applicability(cx, arg.span, string, applicability);
-        let ch = if let ast::StrStyle::Raw(nhash) = style {
-            let nhash = nhash as usize;
-            // for raw string: r##"a"##
-            &snip[(nhash + 2)..(snip.len() - 1 - nhash)]
-        } else {
-            // for regular string: "a"
-            &snip[1..(snip.len() - 1)]
-        };
-
-        let hint = format!(
-            "'{}'",
-            match ch {
-                "'" => "\\'",
-                r"\" => "\\\\",
-                "\\\"" => "\"", // no need to escape `"` in `'"'`
-                _ => ch,
-            }
-        );
-
-        Some(hint)
-    } else {
-        None
-    }
-}
-
 /// The core logic of `check_for_loop_iter` in `unnecessary_iter_cloned.rs`, this function wraps a
 /// use of `CloneOrCopyVisitor`.
 pub(super) fn clone_or_copy_needed<'tcx>(
diff --git a/clippy_lints/src/misc_early/zero_prefixed_literal.rs b/clippy_lints/src/misc_early/zero_prefixed_literal.rs
index 4f9578d1b257..61f4684c9e37 100644
--- a/clippy_lints/src/misc_early/zero_prefixed_literal.rs
+++ b/clippy_lints/src/misc_early/zero_prefixed_literal.rs
@@ -6,7 +6,7 @@ use rustc_span::Span;
 use super::ZERO_PREFIXED_LITERAL;
 
 pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, lit_snip: &str) {
-    let trimmed_lit_snip = lit_snip.trim_start_matches(|c| c == '_' || c == '0');
+    let trimmed_lit_snip = lit_snip.trim_start_matches(['_', '0']);
     span_lint_and_then(
         cx,
         ZERO_PREFIXED_LITERAL,
@@ -20,7 +20,7 @@ pub(super) fn check(cx: &EarlyContext<'_>, lit_span: Span, lit_snip: &str) {
                 Applicability::MaybeIncorrect,
             );
             // do not advise to use octal form if the literal cannot be expressed in base 8.
-            if !lit_snip.contains(|c| c == '8' || c == '9') {
+            if !lit_snip.contains(['8', '9']) {
                 diag.span_suggestion(
                     lit_span,
                     "if you mean to use an octal constant, use `0o`",
diff --git a/clippy_lints/src/string_patterns.rs b/clippy_lints/src/string_patterns.rs
new file mode 100644
index 000000000000..64b5b8f9f27b
--- /dev/null
+++ b/clippy_lints/src/string_patterns.rs
@@ -0,0 +1,227 @@
+use std::ops::ControlFlow;
+
+use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::eager_or_lazy::switch_to_eager_eval;
+use clippy_utils::macros::matching_root_macro_call;
+use clippy_utils::path_to_local_id;
+use clippy_utils::source::{snippet, str_literal_to_char_literal};
+use clippy_utils::visitors::{for_each_expr, Descend};
+use itertools::Itertools;
+use rustc_ast::{BinOpKind, LitKind};
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::declare_lint_pass;
+use rustc_span::{sym, Span};
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for manual `char` comparison in string patterns
+    ///
+    /// ### Why is this bad?
+    /// This can be written more concisely using a `char` or an array of `char`.
+    /// This is more readable and more optimized when comparing to only one `char`.
+    ///
+    /// ### Example
+    /// ```no_run
+    /// "Hello World!".trim_end_matches(|c| c == '.' || c == ',' || c == '!' || c == '?');
+    /// ```
+    /// Use instead:
+    /// ```no_run
+    /// "Hello World!".trim_end_matches(['.', ',', '!', '?']);
+    /// ```
+    #[clippy::version = "1.80.0"]
+    pub MANUAL_PATTERN_CHAR_COMPARISON,
+    style,
+    "manual char comparison in string patterns"
+}
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for string methods that receive a single-character
+    /// `str` as an argument, e.g., `_.split("x")`.
+    ///
+    /// ### Why is this bad?
+    /// While this can make a perf difference on some systems,
+    /// benchmarks have proven inconclusive. But at least using a
+    /// char literal makes it clear that we are looking at a single
+    /// character.
+    ///
+    /// ### Known problems
+    /// Does not catch multi-byte unicode characters. This is by
+    /// design, on many machines, splitting by a non-ascii char is
+    /// actually slower. Please do your own measurements instead of
+    /// relying solely on the results of this lint.
+    ///
+    /// ### Example
+    /// ```rust,ignore
+    /// _.split("x");
+    /// ```
+    ///
+    /// Use instead:
+    /// ```rust,ignore
+    /// _.split('x');
+    /// ```
+    #[clippy::version = "pre 1.29.0"]
+    pub SINGLE_CHAR_PATTERN,
+    pedantic,
+    "using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
+}
+
+declare_lint_pass!(StringPatterns => [MANUAL_PATTERN_CHAR_COMPARISON, SINGLE_CHAR_PATTERN]);
+
+const PATTERN_METHODS: [(&str, usize); 22] = [
+    ("contains", 0),
+    ("starts_with", 0),
+    ("ends_with", 0),
+    ("find", 0),
+    ("rfind", 0),
+    ("split", 0),
+    ("split_inclusive", 0),
+    ("rsplit", 0),
+    ("split_terminator", 0),
+    ("rsplit_terminator", 0),
+    ("splitn", 1),
+    ("rsplitn", 1),
+    ("split_once", 0),
+    ("rsplit_once", 0),
+    ("matches", 0),
+    ("rmatches", 0),
+    ("match_indices", 0),
+    ("rmatch_indices", 0),
+    ("trim_start_matches", 0),
+    ("trim_end_matches", 0),
+    ("replace", 0),
+    ("replacen", 0),
+];
+
+fn check_single_char_pattern_lint(cx: &LateContext<'_>, arg: &Expr<'_>) {
+    let mut applicability = Applicability::MachineApplicable;
+    if let Some(hint) = str_literal_to_char_literal(cx, arg, &mut applicability, true) {
+        span_lint_and_sugg(
+            cx,
+            SINGLE_CHAR_PATTERN,
+            arg.span,
+            "single-character string constant used as pattern",
+            "consider using a `char`",
+            hint,
+            applicability,
+        );
+    }
+}
+
+fn get_char_span<'tcx>(cx: &'_ LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<Span> {
+    if cx.typeck_results().expr_ty_adjusted(expr).is_char()
+        && !expr.span.from_expansion()
+        && switch_to_eager_eval(cx, expr)
+    {
+        Some(expr.span)
+    } else {
+        None
+    }
+}
+
+fn check_manual_pattern_char_comparison(cx: &LateContext<'_>, method_arg: &Expr<'_>) {
+    if let ExprKind::Closure(closure) = method_arg.kind
+        && let body = cx.tcx.hir().body(closure.body)
+        && let Some(PatKind::Binding(_, binding, ..)) = body.params.first().map(|p| p.pat.kind)
+    {
+        let mut set_char_spans: Vec<Span> = Vec::new();
+
+        // We want to retrieve all the comparisons done.
+        // They are ordered in a nested way and so we need to traverse the AST to collect them all.
+        if for_each_expr(cx, body.value, |sub_expr| -> ControlFlow<(), Descend> {
+            match sub_expr.kind {
+                ExprKind::Binary(op, left, right) if op.node == BinOpKind::Eq => {
+                    if path_to_local_id(left, binding)
+                        && let Some(span) = get_char_span(cx, right)
+                    {
+                        set_char_spans.push(span);
+                        ControlFlow::Continue(Descend::No)
+                    } else if path_to_local_id(right, binding)
+                        && let Some(span) = get_char_span(cx, left)
+                    {
+                        set_char_spans.push(span);
+                        ControlFlow::Continue(Descend::No)
+                    } else {
+                        ControlFlow::Break(())
+                    }
+                },
+                ExprKind::Binary(op, _, _) if op.node == BinOpKind::Or => ControlFlow::Continue(Descend::Yes),
+                ExprKind::Match(match_value, [arm, _], _) => {
+                    if matching_root_macro_call(cx, sub_expr.span, sym::matches_macro).is_none()
+                        || arm.guard.is_some()
+                        || !path_to_local_id(match_value, binding)
+                    {
+                        return ControlFlow::Break(());
+                    }
+                    if arm.pat.walk_short(|pat| match pat.kind {
+                        PatKind::Lit(expr) if let ExprKind::Lit(lit) = expr.kind => {
+                            if let LitKind::Char(_) = lit.node {
+                                set_char_spans.push(lit.span);
+                            }
+                            true
+                        },
+                        PatKind::Or(_) => true,
+                        _ => false,
+                    }) {
+                        ControlFlow::Continue(Descend::No)
+                    } else {
+                        ControlFlow::Break(())
+                    }
+                },
+                _ => ControlFlow::Break(()),
+            }
+        })
+        .is_some()
+        {
+            return;
+        }
+        span_lint_and_then(
+            cx,
+            MANUAL_PATTERN_CHAR_COMPARISON,
+            method_arg.span,
+            "this manual char comparison can be written more succinctly",
+            |diag| {
+                if let [set_char_span] = set_char_spans[..] {
+                    diag.span_suggestion(
+                        method_arg.span,
+                        "consider using a `char`",
+                        snippet(cx, set_char_span, "c"),
+                        Applicability::MachineApplicable,
+                    );
+                } else {
+                    diag.span_suggestion(
+                        method_arg.span,
+                        "consider using an array of `char`",
+                        format!(
+                            "[{}]",
+                            set_char_spans.into_iter().map(|span| snippet(cx, span, "c")).join(", ")
+                        ),
+                        Applicability::MachineApplicable,
+                    );
+                }
+            },
+        );
+    }
+}
+
+impl<'tcx> LateLintPass<'tcx> for StringPatterns {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+        if !expr.span.from_expansion()
+            && let ExprKind::MethodCall(method, receiver, args, _) = expr.kind
+            && let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(receiver).kind()
+            && ty.is_str()
+            && let method_name = method.ident.name.as_str()
+            && let Some(&(_, pos)) = PATTERN_METHODS
+                .iter()
+                .find(|(array_method_name, _)| *array_method_name == method_name)
+            && let Some(arg) = args.get(pos)
+        {
+            check_single_char_pattern_lint(cx, arg);
+
+            check_manual_pattern_char_comparison(cx, arg);
+        }
+    }
+}
diff --git a/clippy_utils/src/source.rs b/clippy_utils/src/source.rs
index 69f593fe04ac..b7ff7ebe9105 100644
--- a/clippy_utils/src/source.rs
+++ b/clippy_utils/src/source.rs
@@ -2,6 +2,7 @@
 
 #![allow(clippy::module_name_repetitions)]
 
+use rustc_ast::{LitKind, StrStyle};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::Applicability;
 use rustc_hir::{BlockCheckMode, Expr, ExprKind, UnsafeSource};
@@ -500,6 +501,50 @@ pub fn expand_past_previous_comma(cx: &LateContext<'_>, span: Span) -> Span {
     extended.with_lo(extended.lo() - BytePos(1))
 }
 
+/// Converts `expr` to a `char` literal if it's a `str` literal containing a single
+/// character (or a single byte with `ascii_only`)
+pub fn str_literal_to_char_literal(
+    cx: &LateContext<'_>,
+    expr: &Expr<'_>,
+    applicability: &mut Applicability,
+    ascii_only: bool,
+) -> Option<String> {
+    if let ExprKind::Lit(lit) = &expr.kind
+        && let LitKind::Str(r, style) = lit.node
+        && let string = r.as_str()
+        && let len = if ascii_only {
+            string.len()
+        } else {
+            string.chars().count()
+        }
+        && len == 1
+    {
+        let snip = snippet_with_applicability(cx, expr.span, string, applicability);
+        let ch = if let StrStyle::Raw(nhash) = style {
+            let nhash = nhash as usize;
+            // for raw string: r##"a"##
+            &snip[(nhash + 2)..(snip.len() - 1 - nhash)]
+        } else {
+            // for regular string: "a"
+            &snip[1..(snip.len() - 1)]
+        };
+
+        let hint = format!(
+            "'{}'",
+            match ch {
+                "'" => "\\'",
+                r"\" => "\\\\",
+                "\\\"" => "\"", // no need to escape `"` in `'"'`
+                _ => ch,
+            }
+        );
+
+        Some(hint)
+    } else {
+        None
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::{reindent_multiline, without_block_comments};
diff --git a/tests/ui/manual_pattern_char_comparison.fixed b/tests/ui/manual_pattern_char_comparison.fixed
new file mode 100644
index 000000000000..588226b87e87
--- /dev/null
+++ b/tests/ui/manual_pattern_char_comparison.fixed
@@ -0,0 +1,49 @@
+#![warn(clippy::manual_pattern_char_comparison)]
+
+struct NotStr;
+
+impl NotStr {
+    fn find(&self, _: impl FnMut(char) -> bool) {}
+}
+
+fn main() {
+    let sentence = "Hello, world!";
+    sentence.trim_end_matches(['.', ',', '!', '?']);
+    sentence.split(['\n', 'X']);
+    sentence.split(['\n', 'X']);
+    sentence.splitn(3, 'X');
+    sentence.splitn(3, |c: char| c.is_whitespace() || c == 'X');
+    let char_compare = 'X';
+    sentence.splitn(3, char_compare);
+    sentence.split(['\n', 'X', 'Y']);
+    sentence.splitn(3, 'X');
+    sentence.splitn(3, ['X', 'W']);
+    sentence.find('🎈');
+
+    let not_str = NotStr;
+    not_str.find(|c: char| c == 'X');
+
+    "".find(|c| c == 'a' || c > 'z');
+
+    let x = true;
+    "".find(|c| c == 'a' || x || c == 'b');
+
+    let d = 'd';
+    "".find(|c| c == 'a' || d == 'b');
+
+    "".find(|c| match c {
+        'a' | 'b' => true,
+        _ => c.is_ascii(),
+    });
+
+    "".find(|c| matches!(c, 'a' | 'b' if false));
+
+    "".find(|c| matches!(c, 'a' | '1'..'4'));
+    "".find(|c| c == 'a' || matches!(c, '1'..'4'));
+    macro_rules! m {
+        ($e:expr) => {
+            $e == '?'
+        };
+    }
+    "".find(|c| m!(c));
+}
diff --git a/tests/ui/manual_pattern_char_comparison.rs b/tests/ui/manual_pattern_char_comparison.rs
new file mode 100644
index 000000000000..5078f3ee27f3
--- /dev/null
+++ b/tests/ui/manual_pattern_char_comparison.rs
@@ -0,0 +1,49 @@
+#![warn(clippy::manual_pattern_char_comparison)]
+
+struct NotStr;
+
+impl NotStr {
+    fn find(&self, _: impl FnMut(char) -> bool) {}
+}
+
+fn main() {
+    let sentence = "Hello, world!";
+    sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?');
+    sentence.split(|c: char| c == '\n' || c == 'X');
+    sentence.split(|c| c == '\n' || c == 'X');
+    sentence.splitn(3, |c: char| c == 'X');
+    sentence.splitn(3, |c: char| c.is_whitespace() || c == 'X');
+    let char_compare = 'X';
+    sentence.splitn(3, |c: char| c == char_compare);
+    sentence.split(|c: char| matches!(c, '\n' | 'X' | 'Y'));
+    sentence.splitn(3, |c: char| matches!(c, 'X'));
+    sentence.splitn(3, |c: char| matches!(c, 'X' | 'W'));
+    sentence.find(|c| c == '🎈');
+
+    let not_str = NotStr;
+    not_str.find(|c: char| c == 'X');
+
+    "".find(|c| c == 'a' || c > 'z');
+
+    let x = true;
+    "".find(|c| c == 'a' || x || c == 'b');
+
+    let d = 'd';
+    "".find(|c| c == 'a' || d == 'b');
+
+    "".find(|c| match c {
+        'a' | 'b' => true,
+        _ => c.is_ascii(),
+    });
+
+    "".find(|c| matches!(c, 'a' | 'b' if false));
+
+    "".find(|c| matches!(c, 'a' | '1'..'4'));
+    "".find(|c| c == 'a' || matches!(c, '1'..'4'));
+    macro_rules! m {
+        ($e:expr) => {
+            $e == '?'
+        };
+    }
+    "".find(|c| m!(c));
+}
diff --git a/tests/ui/manual_pattern_char_comparison.stderr b/tests/ui/manual_pattern_char_comparison.stderr
new file mode 100644
index 000000000000..b6b51794a11f
--- /dev/null
+++ b/tests/ui/manual_pattern_char_comparison.stderr
@@ -0,0 +1,59 @@
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:11:31
+   |
+LL |     sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?');
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['.', ',', '!', '?']`
+   |
+   = note: `-D clippy::manual-pattern-char-comparison` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::manual_pattern_char_comparison)]`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:12:20
+   |
+LL |     sentence.split(|c: char| c == '\n' || c == 'X');
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['\n', 'X']`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:13:20
+   |
+LL |     sentence.split(|c| c == '\n' || c == 'X');
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['\n', 'X']`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:14:24
+   |
+LL |     sentence.splitn(3, |c: char| c == 'X');
+   |                        ^^^^^^^^^^^^^^^^^^ help: consider using a `char`: `'X'`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:17:24
+   |
+LL |     sentence.splitn(3, |c: char| c == char_compare);
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using a `char`: `char_compare`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:18:20
+   |
+LL |     sentence.split(|c: char| matches!(c, '\n' | 'X' | 'Y'));
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['\n', 'X', 'Y']`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:19:24
+   |
+LL |     sentence.splitn(3, |c: char| matches!(c, 'X'));
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using a `char`: `'X'`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:20:24
+   |
+LL |     sentence.splitn(3, |c: char| matches!(c, 'X' | 'W'));
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['X', 'W']`
+
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:21:19
+   |
+LL |     sentence.find(|c| c == '🎈');
+   |                   ^^^^^^^^^^^^^ help: consider using a `char`: `'🎈'`
+
+error: aborting due to 9 previous errors
+
diff --git a/tests/ui/search_is_some.rs b/tests/ui/search_is_some.rs
index e8a0920b645d..9a9aaba56adc 100644
--- a/tests/ui/search_is_some.rs
+++ b/tests/ui/search_is_some.rs
@@ -1,5 +1,6 @@
 //@aux-build:option_helpers.rs
 #![warn(clippy::search_is_some)]
+#![allow(clippy::manual_pattern_char_comparison)]
 #![allow(clippy::useless_vec)]
 #![allow(dead_code)]
 extern crate option_helpers;
diff --git a/tests/ui/search_is_some.stderr b/tests/ui/search_is_some.stderr
index b5f84d23284a..b5ef55341770 100644
--- a/tests/ui/search_is_some.stderr
+++ b/tests/ui/search_is_some.stderr
@@ -1,5 +1,5 @@
 error: called `is_some()` after searching an `Iterator` with `find`
-  --> tests/ui/search_is_some.rs:15:13
+  --> tests/ui/search_is_some.rs:16:13
    |
 LL |       let _ = v.iter().find(|&x| {
    |  _____________^
@@ -13,7 +13,7 @@ LL | |                    ).is_some();
    = help: to override `-D warnings` add `#[allow(clippy::search_is_some)]`
 
 error: called `is_some()` after searching an `Iterator` with `position`
-  --> tests/ui/search_is_some.rs:21:13
+  --> tests/ui/search_is_some.rs:22:13
    |
 LL |       let _ = v.iter().position(|&x| {
    |  _____________^
@@ -25,7 +25,7 @@ LL | |                    ).is_some();
    = help: this is more succinctly expressed by calling `any()`
 
 error: called `is_some()` after searching an `Iterator` with `rposition`
-  --> tests/ui/search_is_some.rs:27:13
+  --> tests/ui/search_is_some.rs:28:13
    |
 LL |       let _ = v.iter().rposition(|&x| {
    |  _____________^
@@ -37,13 +37,13 @@ LL | |                    ).is_some();
    = help: this is more succinctly expressed by calling `any()`
 
 error: called `is_some()` after searching an `Iterator` with `find`
-  --> tests/ui/search_is_some.rs:42:20
+  --> tests/ui/search_is_some.rs:43:20
    |
 LL |     let _ = (0..1).find(some_closure).is_some();
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `any(some_closure)`
 
 error: called `is_none()` after searching an `Iterator` with `find`
-  --> tests/ui/search_is_some.rs:52:13
+  --> tests/ui/search_is_some.rs:53:13
    |
 LL |       let _ = v.iter().find(|&x| {
    |  _____________^
@@ -55,7 +55,7 @@ LL | |                    ).is_none();
    = help: this is more succinctly expressed by calling `any()` with negation
 
 error: called `is_none()` after searching an `Iterator` with `position`
-  --> tests/ui/search_is_some.rs:58:13
+  --> tests/ui/search_is_some.rs:59:13
    |
 LL |       let _ = v.iter().position(|&x| {
    |  _____________^
@@ -67,7 +67,7 @@ LL | |                    ).is_none();
    = help: this is more succinctly expressed by calling `any()` with negation
 
 error: called `is_none()` after searching an `Iterator` with `rposition`
-  --> tests/ui/search_is_some.rs:64:13
+  --> tests/ui/search_is_some.rs:65:13
    |
 LL |       let _ = v.iter().rposition(|&x| {
    |  _____________^
@@ -79,7 +79,7 @@ LL | |                    ).is_none();
    = help: this is more succinctly expressed by calling `any()` with negation
 
 error: called `is_none()` after searching an `Iterator` with `find`
-  --> tests/ui/search_is_some.rs:79:13
+  --> tests/ui/search_is_some.rs:80:13
    |
 LL |     let _ = (0..1).find(some_closure).is_none();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `!(0..1).any(some_closure)`

From 614966b0c3caf7558b7ea58c09c4cf17f2497b98 Mon Sep 17 00:00:00 2001
From: Philipp Krones <hello@philkrones.com>
Date: Thu, 13 Jun 2024 12:24:14 +0200
Subject: [PATCH 44/56] Bump Clippy version -> 0.1.81

---
 Cargo.toml                     | 2 +-
 clippy_config/Cargo.toml       | 2 +-
 clippy_lints/Cargo.toml        | 2 +-
 clippy_utils/Cargo.toml        | 2 +-
 declare_clippy_lint/Cargo.toml | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index b48f3ab3919c..437884990551 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy"
-version = "0.1.80"
+version = "0.1.81"
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"
diff --git a/clippy_config/Cargo.toml b/clippy_config/Cargo.toml
index 7f7dc9d6cfb0..be0b048ac0c7 100644
--- a/clippy_config/Cargo.toml
+++ b/clippy_config/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy_config"
-version = "0.1.80"
+version = "0.1.81"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
diff --git a/clippy_lints/Cargo.toml b/clippy_lints/Cargo.toml
index 5e3a119337cc..5708ffba08fd 100644
--- a/clippy_lints/Cargo.toml
+++ b/clippy_lints/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy_lints"
-version = "0.1.80"
+version = "0.1.81"
 description = "A bunch of helpful lints to avoid common pitfalls in Rust"
 repository = "https://github.com/rust-lang/rust-clippy"
 readme = "README.md"
diff --git a/clippy_utils/Cargo.toml b/clippy_utils/Cargo.toml
index ab883c25338b..3a3aeb882164 100644
--- a/clippy_utils/Cargo.toml
+++ b/clippy_utils/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clippy_utils"
-version = "0.1.80"
+version = "0.1.81"
 edition = "2021"
 publish = false
 
diff --git a/declare_clippy_lint/Cargo.toml b/declare_clippy_lint/Cargo.toml
index c8c734c3a7c9..86d945c14a58 100644
--- a/declare_clippy_lint/Cargo.toml
+++ b/declare_clippy_lint/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "declare_clippy_lint"
-version = "0.1.80"
+version = "0.1.81"
 edition = "2021"
 publish = false
 

From 89658ef8203328cf766bb34a6fa38a23143e4137 Mon Sep 17 00:00:00 2001
From: Philipp Krones <hello@philkrones.com>
Date: Thu, 13 Jun 2024 12:24:17 +0200
Subject: [PATCH 45/56] Bump nightly version -> 2024-06-13

---
 rust-toolchain | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust-toolchain b/rust-toolchain
index dd8b9ece773e..842c2f3de0d1 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "nightly-2024-05-30"
+channel = "nightly-2024-06-13"
 components = ["cargo", "llvm-tools", "rust-src", "rust-std", "rustc", "rustc-dev", "rustfmt"]

From 477b0c6a78328656d4223cfdcfda2c8a05cbbe9c Mon Sep 17 00:00:00 2001
From: Alex Macleod <alex@macleod.io>
Date: Tue, 1 Nov 2022 14:42:20 +0000
Subject: [PATCH 46/56] lintcheck: Add JSON output, diff subcommand

---
 lintcheck/Cargo.toml    |   2 +
 lintcheck/src/config.rs |  37 +++++++--
 lintcheck/src/json.rs   | 122 +++++++++++++++++++++++++++++
 lintcheck/src/main.rs   | 167 +++++++++++++++++++++++++---------------
 4 files changed, 261 insertions(+), 67 deletions(-)
 create mode 100644 lintcheck/src/json.rs

diff --git a/lintcheck/Cargo.toml b/lintcheck/Cargo.toml
index 8c5a409e25b1..623af922e2a8 100644
--- a/lintcheck/Cargo.toml
+++ b/lintcheck/Cargo.toml
@@ -16,11 +16,13 @@ cargo_metadata = "0.15.3"
 clap = { version = "4.4", features = ["derive", "env"] }
 crates_io_api = "0.8.1"
 crossbeam-channel = "0.5.6"
+diff = "0.1.13"
 flate2 = "1.0"
 indicatif = "0.17.3"
 rayon = "1.5.1"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.85"
+strip-ansi-escapes = "0.1.1"
 tar = "0.4"
 toml = "0.7.3"
 ureq = "2.2"
diff --git a/lintcheck/src/config.rs b/lintcheck/src/config.rs
index 3f712f453fa0..c3540bbe4ce7 100644
--- a/lintcheck/src/config.rs
+++ b/lintcheck/src/config.rs
@@ -1,8 +1,9 @@
-use clap::Parser;
+use clap::{Parser, Subcommand, ValueEnum};
 use std::num::NonZero;
 use std::path::PathBuf;
 
-#[derive(Clone, Debug, Parser)]
+#[derive(Parser, Clone, Debug)]
+#[command(args_conflicts_with_subcommands = true)]
 pub(crate) struct LintcheckConfig {
     /// Number of threads to use (default: all unless --fix or --recursive)
     #[clap(
@@ -35,12 +36,36 @@ pub(crate) struct LintcheckConfig {
     /// Apply a filter to only collect specified lints, this also overrides `allow` attributes
     #[clap(long = "filter", value_name = "clippy_lint_name", use_value_delimiter = true)]
     pub lint_filter: Vec<String>,
-    /// Change the reports table to use markdown links
-    #[clap(long)]
-    pub markdown: bool,
+    /// Set the output format of the log file
+    #[clap(long, short, default_value = "text")]
+    pub format: OutputFormat,
     /// Run clippy on the dependencies of crates specified in crates-toml
     #[clap(long, conflicts_with("max_jobs"))]
     pub recursive: bool,
+    #[command(subcommand)]
+    pub subcommand: Option<Commands>,
+}
+
+#[derive(Subcommand, Clone, Debug)]
+pub(crate) enum Commands {
+    Diff { old: PathBuf, new: PathBuf },
+}
+
+#[derive(ValueEnum, Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum OutputFormat {
+    Text,
+    Markdown,
+    Json,
+}
+
+impl OutputFormat {
+    fn file_extension(self) -> &'static str {
+        match self {
+            OutputFormat::Text => "txt",
+            OutputFormat::Markdown => "md",
+            OutputFormat::Json => "json",
+        }
+    }
 }
 
 impl LintcheckConfig {
@@ -53,7 +78,7 @@ impl LintcheckConfig {
         config.lintcheck_results_path = PathBuf::from(format!(
             "lintcheck-logs/{}_logs.{}",
             filename.display(),
-            if config.markdown { "md" } else { "txt" }
+            config.format.file_extension(),
         ));
 
         // look at the --threads arg, if 0 is passed, use the threads count
diff --git a/lintcheck/src/json.rs b/lintcheck/src/json.rs
new file mode 100644
index 000000000000..43d0413c7cee
--- /dev/null
+++ b/lintcheck/src/json.rs
@@ -0,0 +1,122 @@
+use std::collections::HashMap;
+use std::fmt::Write;
+use std::fs;
+use std::hash::Hash;
+use std::path::Path;
+
+use crate::ClippyWarning;
+
+/// Creates the log file output for [`crate::config::OutputFormat::Json`]
+pub(crate) fn output(clippy_warnings: &[ClippyWarning]) -> String {
+    serde_json::to_string(&clippy_warnings).unwrap()
+}
+
+fn load_warnings(path: &Path) -> Vec<ClippyWarning> {
+    let file = fs::read(path).unwrap_or_else(|e| panic!("failed to read {}: {e}", path.display()));
+
+    serde_json::from_slice(&file).unwrap_or_else(|e| panic!("failed to deserialize {}: {e}", path.display()))
+}
+
+/// Group warnings by their primary span location + lint name
+fn create_map(warnings: &[ClippyWarning]) -> HashMap<impl Eq + Hash + '_, Vec<&ClippyWarning>> {
+    let mut map = HashMap::<_, Vec<_>>::with_capacity(warnings.len());
+
+    for warning in warnings {
+        let span = warning.span();
+        let key = (&warning.lint_type, &span.file_name, span.byte_start, span.byte_end);
+
+        map.entry(key).or_default().push(warning);
+    }
+
+    map
+}
+
+fn print_warnings(title: &str, warnings: &[&ClippyWarning]) {
+    if warnings.is_empty() {
+        return;
+    }
+
+    println!("### {title}");
+    println!("```");
+    for warning in warnings {
+        print!("{}", warning.diag);
+    }
+    println!("```");
+}
+
+fn print_changed_diff(changed: &[(&[&ClippyWarning], &[&ClippyWarning])]) {
+    fn render(warnings: &[&ClippyWarning]) -> String {
+        let mut rendered = String::new();
+        for warning in warnings {
+            write!(&mut rendered, "{}", warning.diag).unwrap();
+        }
+        rendered
+    }
+
+    if changed.is_empty() {
+        return;
+    }
+
+    println!("### Changed");
+    println!("```diff");
+    for &(old, new) in changed {
+        let old_rendered = render(old);
+        let new_rendered = render(new);
+
+        for change in diff::lines(&old_rendered, &new_rendered) {
+            use diff::Result::{Both, Left, Right};
+
+            match change {
+                Both(unchanged, _) => {
+                    println!(" {unchanged}");
+                },
+                Left(removed) => {
+                    println!("-{removed}");
+                },
+                Right(added) => {
+                    println!("+{added}");
+                },
+            }
+        }
+    }
+    println!("```");
+}
+
+pub(crate) fn diff(old_path: &Path, new_path: &Path) {
+    let old_warnings = load_warnings(old_path);
+    let new_warnings = load_warnings(new_path);
+
+    let old_map = create_map(&old_warnings);
+    let new_map = create_map(&new_warnings);
+
+    let mut added = Vec::new();
+    let mut removed = Vec::new();
+    let mut changed = Vec::new();
+
+    for (key, new) in &new_map {
+        if let Some(old) = old_map.get(key) {
+            if old != new {
+                changed.push((old.as_slice(), new.as_slice()));
+            }
+        } else {
+            added.extend(new);
+        }
+    }
+
+    for (key, old) in &old_map {
+        if !new_map.contains_key(key) {
+            removed.extend(old);
+        }
+    }
+
+    print!(
+        "{} added, {} removed, {} changed\n\n",
+        added.len(),
+        removed.len(),
+        changed.len()
+    );
+
+    print_warnings("Added", &added);
+    print_warnings("Removed", &removed);
+    print_changed_diff(&changed);
+}
diff --git a/lintcheck/src/main.rs b/lintcheck/src/main.rs
index deb06094d83b..985df9647d82 100644
--- a/lintcheck/src/main.rs
+++ b/lintcheck/src/main.rs
@@ -12,18 +12,20 @@
     unused_lifetimes,
     unused_qualifications
 )]
-#![allow(clippy::collapsible_else_if)]
+#![allow(clippy::collapsible_else_if, clippy::needless_borrows_for_generic_args)]
 
 mod config;
 mod driver;
+mod json;
 mod recursive;
 
-use crate::config::LintcheckConfig;
+use crate::config::{Commands, LintcheckConfig, OutputFormat};
 use crate::recursive::LintcheckServer;
 
 use std::collections::{HashMap, HashSet};
 use std::env::consts::EXE_SUFFIX;
-use std::fmt::{self, Write as _};
+use std::fmt::{self, Display, Write as _};
+use std::hash::Hash;
 use std::io::{self, ErrorKind};
 use std::path::{Path, PathBuf};
 use std::process::{Command, ExitStatus};
@@ -31,7 +33,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::time::Duration;
 use std::{env, fs, thread};
 
-use cargo_metadata::diagnostic::Diagnostic;
+use cargo_metadata::diagnostic::{Diagnostic, DiagnosticSpan};
 use cargo_metadata::Message;
 use rayon::prelude::*;
 use serde::{Deserialize, Serialize};
@@ -111,6 +113,17 @@ struct RustcIce {
     pub crate_name: String,
     pub ice_content: String,
 }
+
+impl Display for RustcIce {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}:\n{}\n========================================\n",
+            self.crate_name, self.ice_content
+        )
+    }
+}
+
 impl RustcIce {
     pub fn from_stderr_and_status(crate_name: &str, status: ExitStatus, stderr: &str) -> Option<Self> {
         if status.code().unwrap_or(0) == 101
@@ -127,60 +140,58 @@ impl RustcIce {
 }
 
 /// A single warning that clippy issued while checking a `Crate`
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq, Hash, Serialize, Deserialize)]
 struct ClippyWarning {
-    file: String,
-    line: usize,
-    column: usize,
+    crate_name: String,
+    crate_version: String,
     lint_type: String,
-    message: String,
+    diag: Diagnostic,
 }
 
 #[allow(unused)]
 impl ClippyWarning {
-    fn new(diag: Diagnostic, crate_name: &str, crate_version: &str) -> Option<Self> {
-        let lint_type = diag.code?.code;
+    fn new(mut diag: Diagnostic, crate_name: &str, crate_version: &str) -> Option<Self> {
+        let lint_type = diag.code.clone()?.code;
         if !(lint_type.contains("clippy") || diag.message.contains("clippy"))
             || diag.message.contains("could not read cargo metadata")
         {
             return None;
         }
 
-        let span = diag.spans.into_iter().find(|span| span.is_primary)?;
-
-        let file = if let Ok(stripped) = Path::new(&span.file_name).strip_prefix(env!("CARGO_HOME")) {
-            format!("$CARGO_HOME/{}", stripped.display())
-        } else {
-            format!(
-                "target/lintcheck/sources/{crate_name}-{crate_version}/{}",
-                span.file_name
-            )
-        };
+        // --recursive bypasses cargo so we have to strip the rendered output ourselves
+        let rendered = diag.rendered.as_mut().unwrap();
+        *rendered = String::from_utf8(strip_ansi_escapes::strip(&rendered).unwrap()).unwrap();
 
         Some(Self {
-            file,
-            line: span.line_start,
-            column: span.column_start,
+            crate_name: crate_name.to_owned(),
+            crate_version: crate_version.to_owned(),
             lint_type,
-            message: diag.message,
+            diag,
         })
     }
 
-    fn to_output(&self, markdown: bool) -> String {
-        let file_with_pos = format!("{}:{}:{}", &self.file, &self.line, &self.column);
-        if markdown {
-            let mut file = self.file.clone();
-            if !file.starts_with('$') {
-                file.insert_str(0, "../");
-            }
+    fn span(&self) -> &DiagnosticSpan {
+        self.diag.spans.iter().find(|span| span.is_primary).unwrap()
+    }
 
-            let mut output = String::from("| ");
-            let _: fmt::Result = write!(output, "[`{file_with_pos}`]({file}#L{})", self.line);
-            let _: fmt::Result = write!(output, r#" | `{:<50}` | "{}" |"#, self.lint_type, self.message);
-            output.push('\n');
-            output
-        } else {
-            format!("{file_with_pos} {} \"{}\"\n", self.lint_type, self.message)
+    fn to_output(&self, format: OutputFormat) -> String {
+        let span = self.span();
+        let mut file = span.file_name.clone();
+        let file_with_pos = format!("{file}:{}:{}", span.line_start, span.line_end);
+        match format {
+            OutputFormat::Text => format!("{file_with_pos} {} \"{}\"\n", self.lint_type, self.diag.message),
+            OutputFormat::Markdown => {
+                if file.starts_with("target") {
+                    file.insert_str(0, "../");
+                }
+
+                let mut output = String::from("| ");
+                write!(output, "[`{file_with_pos}`]({file}#L{})", span.line_start).unwrap();
+                write!(output, r#" | `{:<50}` | "{}" |"#, self.lint_type, self.diag.message).unwrap();
+                output.push('\n');
+                output
+            },
+            OutputFormat::Json => unreachable!("JSON output is handled via serde"),
         }
     }
 }
@@ -333,7 +344,7 @@ impl CrateSource {
 impl Crate {
     /// Run `cargo clippy` on the `Crate` and collect and return all the lint warnings that clippy
     /// issued
-    #[allow(clippy::too_many_arguments)]
+    #[allow(clippy::too_many_arguments, clippy::too_many_lines)]
     fn run_clippy_lints(
         &self,
         cargo_clippy_path: &Path,
@@ -372,7 +383,25 @@ impl Crate {
             vec!["--quiet", "--message-format=json", "--"]
         };
 
-        let mut clippy_args = Vec::<&str>::new();
+        let cargo_home = env!("CARGO_HOME");
+
+        // `src/lib.rs` -> `target/lintcheck/sources/crate-1.2.3/src/lib.rs`
+        let remap_relative = format!("={}", self.path.display());
+        // Fallback for other sources, `~/.cargo/...` -> `$CARGO_HOME/...`
+        let remap_cargo_home = format!("{cargo_home}=$CARGO_HOME");
+        // `~/.cargo/registry/src/github.com-1ecc6299db9ec823/crate-2.3.4/src/lib.rs`
+        //     -> `crate-2.3.4/src/lib.rs`
+        let remap_crates_io = format!("{cargo_home}/registry/src/github.com-1ecc6299db9ec823/=");
+
+        let mut clippy_args = vec![
+            "--remap-path-prefix",
+            &remap_relative,
+            "--remap-path-prefix",
+            &remap_cargo_home,
+            "--remap-path-prefix",
+            &remap_crates_io,
+        ];
+
         if let Some(options) = &self.options {
             for opt in options {
                 clippy_args.push(opt);
@@ -554,10 +583,10 @@ fn read_crates(toml_path: &Path) -> (Vec<CrateSource>, RecursiveOptions) {
 }
 
 /// Generate a short list of occurring lints-types and their count
-fn gather_stats(clippy_warnings: &[ClippyWarning]) -> (String, HashMap<&String, usize>) {
+fn gather_stats(warnings: &[ClippyWarning]) -> (String, HashMap<&String, usize>) {
     // count lint type occurrences
     let mut counter: HashMap<&String, usize> = HashMap::new();
-    clippy_warnings
+    warnings
         .iter()
         .for_each(|wrn| *counter.entry(&wrn.lint_type).or_insert(0) += 1);
 
@@ -595,6 +624,11 @@ fn main() {
 
     let config = LintcheckConfig::new();
 
+    if let Some(Commands::Diff { old, new }) = config.subcommand {
+        json::diff(&old, &new);
+        return;
+    }
+
     println!("Compiling clippy...");
     build_clippy();
     println!("Done compiling");
@@ -619,7 +653,6 @@ fn main() {
     // flatten into one big list of warnings
 
     let (crates, recursive_options) = read_crates(&config.sources_toml_path);
-    let old_stats = read_stats_from_file(&config.lintcheck_results_path);
 
     let counter = AtomicUsize::new(1);
     let lint_filter: Vec<String> = config
@@ -711,39 +744,51 @@ fn main() {
         }
     }
 
+    let text = match config.format {
+        OutputFormat::Text | OutputFormat::Markdown => output(&warnings, &raw_ices, clippy_ver, &config),
+        OutputFormat::Json => {
+            if !raw_ices.is_empty() {
+                for ice in raw_ices {
+                    println!("{ice}");
+                }
+                panic!("Some crates ICEd");
+            }
+
+            json::output(&warnings)
+        },
+    };
+
+    println!("Writing logs to {}", config.lintcheck_results_path.display());
+    fs::create_dir_all(config.lintcheck_results_path.parent().unwrap()).unwrap();
+    fs::write(&config.lintcheck_results_path, text).unwrap();
+}
+
+/// Creates the log file output for [`OutputFormat::Text`] and [`OutputFormat::Markdown`]
+fn output(warnings: &[ClippyWarning], ices: &[RustcIce], clippy_ver: String, config: &LintcheckConfig) -> String {
     // generate some stats
-    let (stats_formatted, new_stats) = gather_stats(&warnings);
+    let (stats_formatted, new_stats) = gather_stats(warnings);
+    let old_stats = read_stats_from_file(&config.lintcheck_results_path);
 
-    let mut all_msgs: Vec<String> = warnings.iter().map(|warn| warn.to_output(config.markdown)).collect();
+    let mut all_msgs: Vec<String> = warnings.iter().map(|warn| warn.to_output(config.format)).collect();
     all_msgs.sort();
     all_msgs.push("\n\n### Stats:\n\n".into());
     all_msgs.push(stats_formatted);
 
-    // save the text into lintcheck-logs/logs.txt
     let mut text = clippy_ver; // clippy version number on top
     text.push_str("\n### Reports\n\n");
-    if config.markdown {
+    if config.format == OutputFormat::Markdown {
         text.push_str("| file | lint | message |\n");
         text.push_str("| --- | --- | --- |\n");
     }
     write!(text, "{}", all_msgs.join("")).unwrap();
     text.push_str("\n\n### ICEs:\n");
-    for ice in &raw_ices {
-        let _: fmt::Result = write!(
-            text,
-            "{}:\n{}\n========================================\n\n",
-            ice.crate_name, ice.ice_content
-        );
+    for ice in ices {
+        writeln!(text, "{ice}").unwrap();
     }
 
-    println!("Writing logs to {}", config.lintcheck_results_path.display());
-    if !raw_ices.is_empty() {
-        println!("WARNING: at least one ICE reported, check log file");
-    }
-    fs::create_dir_all(config.lintcheck_results_path.parent().unwrap()).unwrap();
-    fs::write(&config.lintcheck_results_path, text).unwrap();
-
     print_stats(old_stats, new_stats, &config.lint_filter);
+
+    text
 }
 
 /// read the previous stats from the lintcheck-log file

From feb0671893505272bdad18be595ea2c4dcea2063 Mon Sep 17 00:00:00 2001
From: Alex Macleod <alex@macleod.io>
Date: Fri, 24 Feb 2023 17:35:27 +0000
Subject: [PATCH 47/56] Add lintcheck diff github action

---
 .github/workflows/lintcheck.yml | 115 ++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 .github/workflows/lintcheck.yml

diff --git a/.github/workflows/lintcheck.yml b/.github/workflows/lintcheck.yml
new file mode 100644
index 000000000000..0816e5334e20
--- /dev/null
+++ b/.github/workflows/lintcheck.yml
@@ -0,0 +1,115 @@
+name: Lintcheck
+
+on: pull_request
+
+env:
+  RUST_BACKTRACE: 1
+  CARGO_INCREMENTAL: 0
+
+concurrency:
+  # For a given workflow, if we push to the same PR, cancel all previous builds on that PR.
+  group: "${{ github.workflow }}-${{ github.event.pull_request.number}}"
+  cancel-in-progress: true
+
+jobs:
+  # Generates `lintcheck-logs/base.json` and stores it in a cache
+  base:
+    runs-on: ubuntu-latest
+
+    outputs:
+      key: ${{ steps.key.outputs.key }}
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 2
+
+    # HEAD is the generated merge commit `refs/pull/N/merge` between the PR and `master`, `HEAD^`
+    # being the commit from `master` that is the base of the merge
+    - name: Checkout base
+      run: git checkout HEAD^
+
+    # Use the lintcheck from the PR to generate the JSON in case the PR modifies lintcheck in some
+    # way
+    - name: Checkout current lintcheck
+      run: |
+        rm -rf lintcheck
+        git checkout ${{ github.sha }} -- lintcheck
+
+    - name: Create cache key
+      id: key
+      run: echo "key=lintcheck-base-${{ hashfiles('lintcheck/**') }}-$(git rev-parse HEAD)" >> "$GITHUB_OUTPUT"
+
+    - name: Cache results
+      id: cache
+      uses: actions/cache@v4
+      with:
+        path: lintcheck-logs/base.json
+        key: ${{ steps.key.outputs.key }}
+
+    - name: Run lintcheck
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: cargo lintcheck --format json
+
+    - name: Rename JSON file
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: mv lintcheck-logs/lintcheck_crates_logs.json lintcheck-logs/base.json
+
+  # Generates `lintcheck-logs/head.json` and stores it in a cache
+  head:
+    runs-on: ubuntu-latest
+
+    outputs:
+      key: ${{ steps.key.outputs.key }}
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Create cache key
+      id: key
+      run: echo "key=lintcheck-head-${{ github.sha }}" >> "$GITHUB_OUTPUT"
+
+    - name: Cache results
+      id: cache
+      uses: actions/cache@v4
+      with:
+        path: lintcheck-logs/head.json
+        key: ${{ steps.key.outputs.key }}
+
+    - name: Run lintcheck
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: cargo lintcheck --format json
+
+    - name: Rename JSON file
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: mv lintcheck-logs/lintcheck_crates_logs.json lintcheck-logs/head.json
+
+  # Retrieves `lintcheck-logs/base.json` and `lintcheck-logs/head.json` from the cache and prints
+  # the diff to the GH actions step summary
+  diff:
+    runs-on: ubuntu-latest
+
+    needs: [base, head]
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Restore base JSON
+      uses: actions/cache/restore@v4
+      with:
+        key: ${{ needs.base.outputs.key }}
+        path: lintcheck-logs/base.json
+        fail-on-cache-miss: true
+
+    - name: Restore head JSON
+      uses: actions/cache/restore@v4
+      with:
+        key: ${{ needs.head.outputs.key }}
+        path: lintcheck-logs/head.json
+        fail-on-cache-miss: true
+
+    - name: Diff results
+      run: cargo lintcheck diff lintcheck-logs/base.json lintcheck-logs/head.json >> $GITHUB_STEP_SUMMARY

From 63388cbab88a7207d3a3959a92a9ac84e9211336 Mon Sep 17 00:00:00 2001
From: AurelienFT <aurelien.foucault@epitech.eu>
Date: Sat, 15 Jun 2024 21:45:35 +0200
Subject: [PATCH 48/56] add MSRV for manual_pattern_char_comparison

---
 book/src/lint_configuration.md                |  1 +
 clippy_config/src/conf.rs                     |  2 +-
 clippy_lints/src/lib.rs                       |  2 +-
 clippy_lints/src/string_patterns.rs           | 22 ++++++++++++++++---
 tests/ui/manual_pattern_char_comparison.fixed | 12 ++++++++++
 tests/ui/manual_pattern_char_comparison.rs    | 12 ++++++++++
 .../ui/manual_pattern_char_comparison.stderr  |  8 ++++++-
 7 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/book/src/lint_configuration.md b/book/src/lint_configuration.md
index c8223007df7b..adb5b0a54909 100644
--- a/book/src/lint_configuration.md
+++ b/book/src/lint_configuration.md
@@ -693,6 +693,7 @@ The minimum rust version that the project supports. Defaults to the `rust-versio
 * [`manual_is_ascii_check`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_ascii_check)
 * [`manual_let_else`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_let_else)
 * [`manual_non_exhaustive`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive)
+* [`manual_pattern_char_comparison`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_pattern_char_comparison)
 * [`manual_range_contains`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains)
 * [`manual_rem_euclid`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_rem_euclid)
 * [`manual_retain`](https://rust-lang.github.io/rust-clippy/master/index.html#manual_retain)
diff --git a/clippy_config/src/conf.rs b/clippy_config/src/conf.rs
index cfdf620b7d07..93ca535a7a46 100644
--- a/clippy_config/src/conf.rs
+++ b/clippy_config/src/conf.rs
@@ -265,7 +265,7 @@ define_Conf! {
     ///
     /// Suppress lints whenever the suggested change would cause breakage for other crates.
     (avoid_breaking_exported_api: bool = true),
-    /// Lint: MANUAL_SPLIT_ONCE, MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, OPTION_MAP_UNWRAP_OR, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE, APPROX_CONSTANT, DEPRECATED_CFG_ATTR, INDEX_REFUTABLE_SLICE, MAP_CLONE, BORROW_AS_PTR, MANUAL_BITS, ERR_EXPECT, CAST_ABS_TO_UNSIGNED, UNINLINED_FORMAT_ARGS, MANUAL_CLAMP, MANUAL_LET_ELSE, UNCHECKED_DURATION_SUBTRACTION, COLLAPSIBLE_STR_REPLACE, SEEK_FROM_CURRENT, SEEK_REWIND, UNNECESSARY_LAZY_EVALUATIONS, TRANSMUTE_PTR_TO_REF, ALMOST_COMPLETE_RANGE, NEEDLESS_BORROW, DERIVABLE_IMPLS, MANUAL_IS_ASCII_CHECK, MANUAL_REM_EUCLID, MANUAL_RETAIN, TYPE_REPETITION_IN_BOUNDS, TUPLE_ARRAY_CONVERSIONS, MANUAL_TRY_FOLD, MANUAL_HASH_ONE, ITER_KV_MAP, MANUAL_C_STR_LITERALS, ASSIGNING_CLONES, LEGACY_NUMERIC_CONSTANTS.
+    /// Lint: MANUAL_SPLIT_ONCE, MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, OPTION_MAP_UNWRAP_OR, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE, APPROX_CONSTANT, DEPRECATED_CFG_ATTR, INDEX_REFUTABLE_SLICE, MAP_CLONE, BORROW_AS_PTR, MANUAL_BITS, ERR_EXPECT, CAST_ABS_TO_UNSIGNED, UNINLINED_FORMAT_ARGS, MANUAL_CLAMP, MANUAL_LET_ELSE, UNCHECKED_DURATION_SUBTRACTION, COLLAPSIBLE_STR_REPLACE, SEEK_FROM_CURRENT, SEEK_REWIND, UNNECESSARY_LAZY_EVALUATIONS, TRANSMUTE_PTR_TO_REF, ALMOST_COMPLETE_RANGE, NEEDLESS_BORROW, DERIVABLE_IMPLS, MANUAL_IS_ASCII_CHECK, MANUAL_REM_EUCLID, MANUAL_RETAIN, TYPE_REPETITION_IN_BOUNDS, TUPLE_ARRAY_CONVERSIONS, MANUAL_TRY_FOLD, MANUAL_HASH_ONE, ITER_KV_MAP, MANUAL_C_STR_LITERALS, ASSIGNING_CLONES, LEGACY_NUMERIC_CONSTANTS, MANUAL_PATTERN_CHAR_COMPARISON.
     ///
     /// The minimum rust version that the project supports. Defaults to the `rust-version` field in `Cargo.toml`
     #[default_text = ""]
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index c65581d5203e..50274a715ec1 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -1168,7 +1168,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
             ..Default::default()
         })
     });
-    store.register_late_pass(|_| Box::new(string_patterns::StringPatterns));
+    store.register_late_pass(move |_| Box::new(string_patterns::StringPatterns::new(msrv())));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 
diff --git a/clippy_lints/src/string_patterns.rs b/clippy_lints/src/string_patterns.rs
index 64b5b8f9f27b..084a4b597322 100644
--- a/clippy_lints/src/string_patterns.rs
+++ b/clippy_lints/src/string_patterns.rs
@@ -1,5 +1,6 @@
 use std::ops::ControlFlow;
 
+use clippy_config::msrvs::{self, Msrv};
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::eager_or_lazy::switch_to_eager_eval;
 use clippy_utils::macros::matching_root_macro_call;
@@ -12,7 +13,7 @@ use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
-use rustc_session::declare_lint_pass;
+use rustc_session::impl_lint_pass;
 use rustc_span::{sym, Span};
 
 declare_clippy_lint! {
@@ -69,7 +70,18 @@ declare_clippy_lint! {
     "using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
 }
 
-declare_lint_pass!(StringPatterns => [MANUAL_PATTERN_CHAR_COMPARISON, SINGLE_CHAR_PATTERN]);
+pub struct StringPatterns {
+    msrv: Msrv,
+}
+
+impl StringPatterns {
+    #[must_use]
+    pub fn new(msrv: Msrv) -> Self {
+        Self { msrv }
+    }
+}
+
+impl_lint_pass!(StringPatterns => [MANUAL_PATTERN_CHAR_COMPARISON, SINGLE_CHAR_PATTERN]);
 
 const PATTERN_METHODS: [(&str, usize); 22] = [
     ("contains", 0),
@@ -220,8 +232,12 @@ impl<'tcx> LateLintPass<'tcx> for StringPatterns {
             && let Some(arg) = args.get(pos)
         {
             check_single_char_pattern_lint(cx, arg);
-
+            if !self.msrv.meets(msrvs::PATTERN_TRAIT_CHAR_ARRAY) {
+                return;
+            }
             check_manual_pattern_char_comparison(cx, arg);
         }
     }
+
+    extract_msrv_attr!(LateContext);
 }
diff --git a/tests/ui/manual_pattern_char_comparison.fixed b/tests/ui/manual_pattern_char_comparison.fixed
index 588226b87e87..6020d7071bdf 100644
--- a/tests/ui/manual_pattern_char_comparison.fixed
+++ b/tests/ui/manual_pattern_char_comparison.fixed
@@ -47,3 +47,15 @@ fn main() {
     }
     "".find(|c| m!(c));
 }
+
+#[clippy::msrv = "1.57"]
+fn msrv_1_57() {
+    let sentence = "Hello, world!";
+    sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?');
+}
+
+#[clippy::msrv = "1.58"]
+fn msrv_1_58() {
+    let sentence = "Hello, world!";
+    sentence.trim_end_matches(['.', ',', '!', '?']);
+}
\ No newline at end of file
diff --git a/tests/ui/manual_pattern_char_comparison.rs b/tests/ui/manual_pattern_char_comparison.rs
index 5078f3ee27f3..43e883cd325a 100644
--- a/tests/ui/manual_pattern_char_comparison.rs
+++ b/tests/ui/manual_pattern_char_comparison.rs
@@ -47,3 +47,15 @@ fn main() {
     }
     "".find(|c| m!(c));
 }
+
+#[clippy::msrv = "1.57"]
+fn msrv_1_57() {
+    let sentence = "Hello, world!";
+    sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?');
+}
+
+#[clippy::msrv = "1.58"]
+fn msrv_1_58() {
+    let sentence = "Hello, world!";
+    sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?');
+}
diff --git a/tests/ui/manual_pattern_char_comparison.stderr b/tests/ui/manual_pattern_char_comparison.stderr
index b6b51794a11f..f185d7c8f676 100644
--- a/tests/ui/manual_pattern_char_comparison.stderr
+++ b/tests/ui/manual_pattern_char_comparison.stderr
@@ -55,5 +55,11 @@ error: this manual char comparison can be written more succinctly
 LL |     sentence.find(|c| c == '🎈');
    |                   ^^^^^^^^^^^^^ help: consider using a `char`: `'🎈'`
 
-error: aborting due to 9 previous errors
+error: this manual char comparison can be written more succinctly
+  --> tests/ui/manual_pattern_char_comparison.rs:60:31
+   |
+LL |     sentence.trim_end_matches(|c: char| c == '.' || c == ',' || c == '!' || c == '?');
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using an array of `char`: `['.', ',', '!', '?']`
+
+error: aborting due to 10 previous errors
 

From 51c6630d4f70d3c371cbda470358f85e9e2c3918 Mon Sep 17 00:00:00 2001
From: AurelienFT <aurelien.foucault@epitech.eu>
Date: Sat, 15 Jun 2024 21:52:42 +0200
Subject: [PATCH 49/56] Change MSRV check for manual_pattern_char_comparison
 only for pattern arrays

---
 clippy_lints/src/string_patterns.rs           | 11 ++++++-----
 tests/ui/manual_pattern_char_comparison.fixed |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/clippy_lints/src/string_patterns.rs b/clippy_lints/src/string_patterns.rs
index 084a4b597322..7ba58942a175 100644
--- a/clippy_lints/src/string_patterns.rs
+++ b/clippy_lints/src/string_patterns.rs
@@ -134,7 +134,7 @@ fn get_char_span<'tcx>(cx: &'_ LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Optio
     }
 }
 
-fn check_manual_pattern_char_comparison(cx: &LateContext<'_>, method_arg: &Expr<'_>) {
+fn check_manual_pattern_char_comparison(cx: &LateContext<'_>, method_arg: &Expr<'_>, msrv: &Msrv) {
     if let ExprKind::Closure(closure) = method_arg.kind
         && let body = cx.tcx.hir().body(closure.body)
         && let Some(PatKind::Binding(_, binding, ..)) = body.params.first().map(|p| p.pat.kind)
@@ -190,6 +190,9 @@ fn check_manual_pattern_char_comparison(cx: &LateContext<'_>, method_arg: &Expr<
         {
             return;
         }
+        if set_char_spans.len() > 1 && !msrv.meets(msrvs::PATTERN_TRAIT_CHAR_ARRAY) {
+            return;
+        }
         span_lint_and_then(
             cx,
             MANUAL_PATTERN_CHAR_COMPARISON,
@@ -232,10 +235,8 @@ impl<'tcx> LateLintPass<'tcx> for StringPatterns {
             && let Some(arg) = args.get(pos)
         {
             check_single_char_pattern_lint(cx, arg);
-            if !self.msrv.meets(msrvs::PATTERN_TRAIT_CHAR_ARRAY) {
-                return;
-            }
-            check_manual_pattern_char_comparison(cx, arg);
+
+            check_manual_pattern_char_comparison(cx, arg, &self.msrv);
         }
     }
 
diff --git a/tests/ui/manual_pattern_char_comparison.fixed b/tests/ui/manual_pattern_char_comparison.fixed
index 6020d7071bdf..03e621d95ba1 100644
--- a/tests/ui/manual_pattern_char_comparison.fixed
+++ b/tests/ui/manual_pattern_char_comparison.fixed
@@ -58,4 +58,4 @@ fn msrv_1_57() {
 fn msrv_1_58() {
     let sentence = "Hello, world!";
     sentence.trim_end_matches(['.', ',', '!', '?']);
-}
\ No newline at end of file
+}

From bcc7b0e7000ccd13736e6d9f039858fa2f919e28 Mon Sep 17 00:00:00 2001
From: Elijah Potter <me@elijahpotter.dev>
Date: Sat, 15 Jun 2024 13:55:16 -0600
Subject: [PATCH 50/56] Fix minor typo

---
 book/src/usage.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/book/src/usage.md b/book/src/usage.md
index 36448e4cccfa..7a0be6994fe1 100644
--- a/book/src/usage.md
+++ b/book/src/usage.md
@@ -36,7 +36,7 @@ You can configure lint levels on the command line by adding
 cargo clippy -- -Aclippy::style -Wclippy::double_neg -Dclippy::perf
 ```
 
-For [CI] all warnings can be elevated to errors which will inturn fail
+For [CI] all warnings can be elevated to errors which will in turn fail
 the build and cause Clippy to exit with a code other than `0`.
 
 ```

From 3a983c399aecc348c5f01a6dcaa03f4f8ac0ea7e Mon Sep 17 00:00:00 2001
From: Alex Macleod <alex@macleod.io>
Date: Sun, 16 Jun 2024 18:28:00 +0000
Subject: [PATCH 51/56] Merge lintcheck popular-crates bin as a subcommand

---
 lintcheck/Cargo.toml            | 13 +------
 lintcheck/README.md             |  6 +--
 lintcheck/src/config.rs         |  9 +++++
 lintcheck/src/main.rs           | 20 ++++++----
 lintcheck/src/popular-crates.rs | 65 ---------------------------------
 lintcheck/src/popular_crates.rs | 52 ++++++++++++++++++++++++++
 6 files changed, 77 insertions(+), 88 deletions(-)
 delete mode 100644 lintcheck/src/popular-crates.rs
 create mode 100644 lintcheck/src/popular_crates.rs

diff --git a/lintcheck/Cargo.toml b/lintcheck/Cargo.toml
index 623af922e2a8..e0e94d7fec3e 100644
--- a/lintcheck/Cargo.toml
+++ b/lintcheck/Cargo.toml
@@ -11,30 +11,19 @@ publish = false
 default-run = "lintcheck"
 
 [dependencies]
-anyhow = "1.0.69"
 cargo_metadata = "0.15.3"
 clap = { version = "4.4", features = ["derive", "env"] }
-crates_io_api = "0.8.1"
 crossbeam-channel = "0.5.6"
 diff = "0.1.13"
 flate2 = "1.0"
-indicatif = "0.17.3"
 rayon = "1.5.1"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.85"
 strip-ansi-escapes = "0.1.1"
 tar = "0.4"
 toml = "0.7.3"
-ureq = "2.2"
+ureq = { version = "2.2", features = ["json"] }
 walkdir = "2.3"
 
 [features]
 deny-warnings = []
-
-[[bin]]
-name = "lintcheck"
-path = "src/main.rs"
-
-[[bin]]
-name = "popular-crates"
-path = "src/popular-crates.rs"
diff --git a/lintcheck/README.md b/lintcheck/README.md
index 61b581ba0fae..2d6039caeef0 100644
--- a/lintcheck/README.md
+++ b/lintcheck/README.md
@@ -26,11 +26,11 @@ the repo root.
 The results will then be saved to `lintcheck-logs/custom_logs.toml`.
 
 The `custom.toml` file may be built using <https://crates.io> recently most
-downloaded crates by using the `popular-crates` binary from the `lintcheck`
-directory. For example, to retrieve the 100 recently most downloaded crates:
+downloaded crates by using `cargo lintcheck popular`. For example, to retrieve
+the 200 recently most downloaded crates:
 
 ```
-cargo run --release --bin popular-crates -- -n 100 custom.toml
+cargo lintcheck popular -n 200 custom.toml
 ```
 
 
diff --git a/lintcheck/src/config.rs b/lintcheck/src/config.rs
index c3540bbe4ce7..e6cd7c9fdc2b 100644
--- a/lintcheck/src/config.rs
+++ b/lintcheck/src/config.rs
@@ -48,7 +48,16 @@ pub(crate) struct LintcheckConfig {
 
 #[derive(Subcommand, Clone, Debug)]
 pub(crate) enum Commands {
+    /// Display a markdown diff between two lintcheck log files in JSON format
     Diff { old: PathBuf, new: PathBuf },
+    /// Create a lintcheck crates TOML file containing the top N popular crates
+    Popular {
+        /// Output TOML file name
+        output: PathBuf,
+        /// Number of crate names to download
+        #[clap(short, long, default_value_t = 100)]
+        number: usize,
+    },
 }
 
 #[derive(ValueEnum, Debug, Clone, Copy, PartialEq, Eq)]
diff --git a/lintcheck/src/main.rs b/lintcheck/src/main.rs
index 985df9647d82..c246883c7045 100644
--- a/lintcheck/src/main.rs
+++ b/lintcheck/src/main.rs
@@ -17,6 +17,7 @@
 mod config;
 mod driver;
 mod json;
+mod popular_crates;
 mod recursive;
 
 use crate::config::{Commands, LintcheckConfig, OutputFormat};
@@ -43,21 +44,21 @@ const LINTCHECK_DOWNLOADS: &str = "target/lintcheck/downloads";
 const LINTCHECK_SOURCES: &str = "target/lintcheck/sources";
 
 /// List of sources to check, loaded from a .toml file
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Deserialize)]
 struct SourceList {
     crates: HashMap<String, TomlCrate>,
     #[serde(default)]
     recursive: RecursiveOptions,
 }
 
-#[derive(Debug, Serialize, Deserialize, Default)]
+#[derive(Debug, Deserialize, Default)]
 struct RecursiveOptions {
     ignore: HashSet<String>,
 }
 
 /// A crate source stored inside the .toml
 /// will be translated into on one of the `CrateSource` variants
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Deserialize)]
 struct TomlCrate {
     name: String,
     versions: Option<Vec<String>>,
@@ -69,7 +70,7 @@ struct TomlCrate {
 
 /// Represents an archive we download from crates.io, or a git repo, or a local repo/folder
 /// Once processed (downloaded/extracted/cloned/copied...), this will be translated into a `Crate`
-#[derive(Debug, Serialize, Deserialize, Eq, Hash, PartialEq, Ord, PartialOrd)]
+#[derive(Debug, Deserialize, Eq, Hash, PartialEq, Ord, PartialOrd)]
 enum CrateSource {
     CratesIo {
         name: String,
@@ -609,7 +610,6 @@ fn gather_stats(warnings: &[ClippyWarning]) -> (String, HashMap<&String, usize>)
     (stats_string, counter)
 }
 
-#[allow(clippy::too_many_lines)]
 fn main() {
     // We're being executed as a `RUSTC_WRAPPER` as part of `--recursive`
     if let Ok(addr) = env::var("LINTCHECK_SERVER") {
@@ -624,11 +624,15 @@ fn main() {
 
     let config = LintcheckConfig::new();
 
-    if let Some(Commands::Diff { old, new }) = config.subcommand {
-        json::diff(&old, &new);
-        return;
+    match config.subcommand {
+        Some(Commands::Diff { old, new }) => json::diff(&old, &new),
+        Some(Commands::Popular { output, number }) => popular_crates::fetch(output, number).unwrap(),
+        None => lintcheck(config),
     }
+}
 
+#[allow(clippy::too_many_lines)]
+fn lintcheck(config: LintcheckConfig) {
     println!("Compiling clippy...");
     build_clippy();
     println!("Done compiling");
diff --git a/lintcheck/src/popular-crates.rs b/lintcheck/src/popular-crates.rs
deleted file mode 100644
index fdab984ad86c..000000000000
--- a/lintcheck/src/popular-crates.rs
+++ /dev/null
@@ -1,65 +0,0 @@
-#![deny(clippy::pedantic)]
-
-use clap::Parser;
-use crates_io_api::{CratesQueryBuilder, Sort, SyncClient};
-use indicatif::ProgressBar;
-use std::collections::HashSet;
-use std::fs::File;
-use std::io::{BufWriter, Write};
-use std::path::PathBuf;
-use std::time::Duration;
-
-#[derive(Parser)]
-struct Opts {
-    /// Output TOML file name
-    output: PathBuf,
-    /// Number of crate names to download
-    #[clap(short, long, default_value_t = 100)]
-    number: usize,
-    /// Do not output progress
-    #[clap(short, long)]
-    quiet: bool,
-}
-
-fn main() -> anyhow::Result<()> {
-    let opts = Opts::parse();
-    let mut output = BufWriter::new(File::create(opts.output)?);
-    output.write_all(b"[crates]\n")?;
-    let client = SyncClient::new(
-        "clippy/lintcheck (github.com/rust-lang/rust-clippy/)",
-        Duration::from_secs(1),
-    )?;
-    let mut seen_crates = HashSet::new();
-    let pb = if opts.quiet {
-        None
-    } else {
-        Some(ProgressBar::new(opts.number as u64))
-    };
-    let mut query = CratesQueryBuilder::new()
-        .sort(Sort::RecentDownloads)
-        .page_size(100)
-        .build();
-    while seen_crates.len() < opts.number {
-        let retrieved = client.crates(query.clone())?.crates;
-        if retrieved.is_empty() {
-            eprintln!("No more than {} crates available from API", seen_crates.len());
-            break;
-        }
-        for c in retrieved {
-            if seen_crates.insert(c.name.clone()) {
-                output.write_all(
-                    format!(
-                        "{} = {{ name = '{}', versions = ['{}'] }}\n",
-                        c.name, c.name, c.max_version
-                    )
-                    .as_bytes(),
-                )?;
-                if let Some(pb) = &pb {
-                    pb.inc(1);
-                }
-            }
-        }
-        query.set_page(query.page() + 1);
-    }
-    Ok(())
-}
diff --git a/lintcheck/src/popular_crates.rs b/lintcheck/src/popular_crates.rs
new file mode 100644
index 000000000000..880a8bd81f08
--- /dev/null
+++ b/lintcheck/src/popular_crates.rs
@@ -0,0 +1,52 @@
+use serde::Deserialize;
+use std::error::Error;
+use std::fmt::Write;
+use std::fs;
+use std::path::PathBuf;
+
+#[derive(Deserialize, Debug)]
+struct Page {
+    crates: Vec<Crate>,
+    meta: Meta,
+}
+
+#[derive(Deserialize, Debug)]
+struct Crate {
+    name: String,
+    max_version: String,
+}
+
+#[derive(Deserialize, Debug)]
+struct Meta {
+    next_page: String,
+}
+
+pub(crate) fn fetch(output: PathBuf, number: usize) -> Result<(), Box<dyn Error>> {
+    let agent = ureq::builder()
+        .user_agent("clippy/lintcheck (github.com/rust-lang/rust-clippy/)")
+        .build();
+
+    let mut crates = Vec::with_capacity(number);
+    let mut query = "?sort=recent-downloads&per_page=100".to_string();
+    while crates.len() < number {
+        let page: Page = agent
+            .get(&format!("https://crates.io/api/v1/crates{query}"))
+            .call()?
+            .into_json()?;
+
+        query = page.meta.next_page;
+        crates.extend(page.crates);
+        crates.truncate(number);
+
+        let width = number.ilog10() as usize + 1;
+        println!("Fetched {:>width$}/{number} crates", crates.len());
+    }
+
+    let mut out = "[crates]\n".to_string();
+    for Crate { name, max_version } in crates {
+        writeln!(out, "{name} = {{ name = '{name}', versions = ['{max_version}'] }}").unwrap();
+    }
+    fs::write(output, out)?;
+
+    Ok(())
+}

From 3405ce3bcaeb445bc780a5ad863524dea151a385 Mon Sep 17 00:00:00 2001
From: kyle oneill <kyleoneill24@gmail.com>
Date: Sun, 16 Jun 2024 15:54:48 -0400
Subject: [PATCH 52/56] Add field_scoped_visibility_modifiers lint

---
 CHANGELOG.md                                  |  1 +
 clippy_lints/src/declared_lints.rs            |  1 +
 .../src/field_scoped_visibility_modifiers.rs  | 75 +++++++++++++++++++
 clippy_lints/src/lib.rs                       |  2 +
 tests/ui/field_scoped_visibility_modifiers.rs | 21 ++++++
 .../field_scoped_visibility_modifiers.stderr  | 28 +++++++
 6 files changed, 128 insertions(+)
 create mode 100644 clippy_lints/src/field_scoped_visibility_modifiers.rs
 create mode 100644 tests/ui/field_scoped_visibility_modifiers.rs
 create mode 100644 tests/ui/field_scoped_visibility_modifiers.stderr

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7bcd7a19687..4de3124bd3da 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5362,6 +5362,7 @@ Released 2018-09-13
 [`extra_unused_type_parameters`]: https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_type_parameters
 [`fallible_impl_from`]: https://rust-lang.github.io/rust-clippy/master/index.html#fallible_impl_from
 [`field_reassign_with_default`]: https://rust-lang.github.io/rust-clippy/master/index.html#field_reassign_with_default
+[`field_scoped_visibility_modifiers`]: https://rust-lang.github.io/rust-clippy/master/index.html#field_scoped_visibility_modifiers
 [`filetype_is_file`]: https://rust-lang.github.io/rust-clippy/master/index.html#filetype_is_file
 [`filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map
 [`filter_map_bool_then`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_bool_then
diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs
index 7e43a99e9f24..88986f9ad727 100644
--- a/clippy_lints/src/declared_lints.rs
+++ b/clippy_lints/src/declared_lints.rs
@@ -178,6 +178,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::explicit_write::EXPLICIT_WRITE_INFO,
     crate::extra_unused_type_parameters::EXTRA_UNUSED_TYPE_PARAMETERS_INFO,
     crate::fallible_impl_from::FALLIBLE_IMPL_FROM_INFO,
+    crate::field_scoped_visibility_modifiers::FIELD_SCOPED_VISIBILITY_MODIFIERS_INFO,
     crate::float_literal::EXCESSIVE_PRECISION_INFO,
     crate::float_literal::LOSSY_FLOAT_LITERAL_INFO,
     crate::floating_point_arithmetic::IMPRECISE_FLOPS_INFO,
diff --git a/clippy_lints/src/field_scoped_visibility_modifiers.rs b/clippy_lints/src/field_scoped_visibility_modifiers.rs
new file mode 100644
index 000000000000..bb74e345703f
--- /dev/null
+++ b/clippy_lints/src/field_scoped_visibility_modifiers.rs
@@ -0,0 +1,75 @@
+use clippy_utils::diagnostics::span_lint_and_help;
+use rustc_ast::ast::{Item, ItemKind, VisibilityKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::declare_lint_pass;
+
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for usage of scoped visibility modifiers, like `pub(crate)`, on fields. These
+    /// make a field visible within a scope between public and private.
+    ///
+    /// ### Why restrict this?
+    /// Scoped visibility modifiers cause a field to be accessible within some scope between
+    /// public and private, potentially within an entire crate. This allows for fields to be
+    /// non-private while upholding internal invariants, but can be a code smell. Scoped visibility
+    /// requires checking a greater area, potentially an entire crate, to verify that an invariant
+    /// is upheld, and global analysis requires a lot of effort.
+    ///
+    /// ### Example
+    /// ```no_run
+    /// pub mod public_module {
+    ///     struct MyStruct {
+    ///         pub(crate) first_field: bool,
+    ///         pub(super) second_field: bool
+    ///     }
+    /// }
+    /// ```
+    /// Use instead:
+    /// ```no_run
+    /// pub mod public_module {
+    ///     struct MyStruct {
+    ///         first_field: bool,
+    ///         second_field: bool
+    ///     }
+    ///     impl MyStruct {
+    ///         pub(crate) fn get_first_field(&self) -> bool {
+    ///             self.first_field
+    ///         }
+    ///         pub(super) fn get_second_field(&self) -> bool {
+    ///             self.second_field
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    #[clippy::version = "1.78.0"]
+    pub FIELD_SCOPED_VISIBILITY_MODIFIERS,
+    restriction,
+    "checks for usage of a scoped visibility modifier, like `pub(crate)`, on fields"
+}
+
+declare_lint_pass!(FieldScopedVisibilityModifiers => [FIELD_SCOPED_VISIBILITY_MODIFIERS]);
+
+impl EarlyLintPass for FieldScopedVisibilityModifiers {
+    fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+        let ItemKind::Struct(ref st, _) = item.kind else {
+            return;
+        };
+        for field in st.fields() {
+            let VisibilityKind::Restricted { path, .. } = &field.vis.kind else {
+                continue;
+            };
+            if !path.segments.is_empty() && path.segments[0].ident.name == rustc_span::symbol::kw::SelfLower {
+                // pub(self) is equivalent to not using pub at all, so we ignore it
+                continue;
+            }
+            span_lint_and_help(
+                cx,
+                FIELD_SCOPED_VISIBILITY_MODIFIERS,
+                field.vis.span,
+                "scoped visibility modifier on a field",
+                None,
+                "consider making the field private and adding a scoped visibility method for it",
+            );
+        }
+    }
+}
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 50274a715ec1..1bd6dfe24617 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -136,6 +136,7 @@ mod exit;
 mod explicit_write;
 mod extra_unused_type_parameters;
 mod fallible_impl_from;
+mod field_scoped_visibility_modifiers;
 mod float_literal;
 mod floating_point_arithmetic;
 mod format;
@@ -1169,6 +1170,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
         })
     });
     store.register_late_pass(move |_| Box::new(string_patterns::StringPatterns::new(msrv())));
+    store.register_early_pass(|| Box::new(field_scoped_visibility_modifiers::FieldScopedVisibilityModifiers));
     // add lints here, do not remove this comment, it's used in `new_lint`
 }
 
diff --git a/tests/ui/field_scoped_visibility_modifiers.rs b/tests/ui/field_scoped_visibility_modifiers.rs
new file mode 100644
index 000000000000..5789dbf9b1d7
--- /dev/null
+++ b/tests/ui/field_scoped_visibility_modifiers.rs
@@ -0,0 +1,21 @@
+#![warn(clippy::field_scoped_visibility_modifiers)]
+
+pub mod pub_module {
+    pub(in crate::pub_module) mod pub_in_path_module {}
+    pub(super) mod pub_super_module {}
+    struct MyStruct {
+        private_field: bool,
+        pub pub_field: bool,
+        pub(crate) pub_crate_field: bool,
+        pub(in crate::pub_module) pub_in_path_field: bool,
+        pub(super) pub_super_field: bool,
+        #[allow(clippy::needless_pub_self)]
+        pub(self) pub_self_field: bool,
+    }
+}
+pub(crate) mod pub_crate_module {}
+
+#[allow(clippy::needless_pub_self)]
+pub(self) mod pub_self_module {}
+
+fn main() {}
diff --git a/tests/ui/field_scoped_visibility_modifiers.stderr b/tests/ui/field_scoped_visibility_modifiers.stderr
new file mode 100644
index 000000000000..beea6c92107c
--- /dev/null
+++ b/tests/ui/field_scoped_visibility_modifiers.stderr
@@ -0,0 +1,28 @@
+error: scoped visibility modifier on a field
+  --> tests/ui/field_scoped_visibility_modifiers.rs:9:9
+   |
+LL |         pub(crate) pub_crate_field: bool,
+   |         ^^^^^^^^^^
+   |
+   = help: consider making the field private and adding a scoped visibility method for it
+   = note: `-D clippy::field-scoped-visibility-modifiers` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::field_scoped_visibility_modifiers)]`
+
+error: scoped visibility modifier on a field
+  --> tests/ui/field_scoped_visibility_modifiers.rs:10:9
+   |
+LL |         pub(in crate::pub_module) pub_in_path_field: bool,
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider making the field private and adding a scoped visibility method for it
+
+error: scoped visibility modifier on a field
+  --> tests/ui/field_scoped_visibility_modifiers.rs:11:9
+   |
+LL |         pub(super) pub_super_field: bool,
+   |         ^^^^^^^^^^
+   |
+   = help: consider making the field private and adding a scoped visibility method for it
+
+error: aborting due to 3 previous errors
+

From a002f93e51e66204e81779d7d449a50e30571c6c Mon Sep 17 00:00:00 2001
From: Jason Newcomb <jsnewcomb@pm.me>
Date: Mon, 12 Feb 2024 18:33:10 -0500
Subject: [PATCH 53/56] `expr_use_ctxt` changes: * Delay the parsing of the use
 node * Mark when the `SyntaxContext` changes rather than return `None` *
 Return a default value if the HIR tree is broken rather than `None`

---
 clippy_lints/src/casts/ref_as_ptr.rs          |   4 +-
 clippy_lints/src/dereference.rs               |  46 +++--
 .../src/needless_borrows_for_generic_args.rs  |   8 +-
 clippy_utils/src/lib.rs                       | 164 ++++++++++--------
 4 files changed, 120 insertions(+), 102 deletions(-)

diff --git a/clippy_lints/src/casts/ref_as_ptr.rs b/clippy_lints/src/casts/ref_as_ptr.rs
index f42bafce4dde..5f48b8bd2063 100644
--- a/clippy_lints/src/casts/ref_as_ptr.rs
+++ b/clippy_lints/src/casts/ref_as_ptr.rs
@@ -22,9 +22,9 @@ pub(super) fn check<'tcx>(
 
     if matches!(cast_from.kind(), ty::Ref(..))
         && let ty::RawPtr(_, to_mutbl) = cast_to.kind()
-        && let Some(use_cx) = expr_use_ctxt(cx, expr)
+        && let use_cx = expr_use_ctxt(cx, expr)
         // TODO: only block the lint if `cast_expr` is a temporary
-        && !matches!(use_cx.node, ExprUseNode::LetStmt(_) | ExprUseNode::ConstStatic(_))
+        && !matches!(use_cx.use_node(cx), ExprUseNode::LetStmt(_) | ExprUseNode::ConstStatic(_))
     {
         let core_or_std = if is_no_std_crate(cx) { "core" } else { "std" };
         let fn_name = match to_mutbl {
diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs
index d60320d82825..3c137b6b70fa 100644
--- a/clippy_lints/src/dereference.rs
+++ b/clippy_lints/src/dereference.rs
@@ -260,18 +260,13 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
             (None, kind) => {
                 let expr_ty = typeck.expr_ty(expr);
                 let use_cx = expr_use_ctxt(cx, expr);
-                let adjusted_ty = match &use_cx {
-                    Some(use_cx) => match use_cx.adjustments {
-                        [.., a] => a.target,
-                        _ => expr_ty,
-                    },
-                    _ => typeck.expr_ty_adjusted(expr),
-                };
+                let adjusted_ty = use_cx.adjustments.last().map_or(expr_ty, |a| a.target);
 
-                match (use_cx, kind) {
-                    (Some(use_cx), RefOp::Deref) => {
+                match kind {
+                    RefOp::Deref if use_cx.same_ctxt => {
+                        let use_node = use_cx.use_node(cx);
                         let sub_ty = typeck.expr_ty(sub_expr);
-                        if let ExprUseNode::FieldAccess(name) = use_cx.node
+                        if let ExprUseNode::FieldAccess(name) = use_node
                             && !use_cx.moved_before_use
                             && !ty_contains_field(sub_ty, name.name)
                         {
@@ -288,9 +283,9 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                         } else if sub_ty.is_ref()
                             // Linting method receivers would require verifying that name lookup
                             // would resolve the same way. This is complicated by trait methods.
-                            && !use_cx.node.is_recv()
-                            && let Some(ty) = use_cx.node.defined_ty(cx)
-                            && TyCoercionStability::for_defined_ty(cx, ty, use_cx.node.is_return()).is_deref_stable()
+                            && !use_node.is_recv()
+                            && let Some(ty) = use_node.defined_ty(cx)
+                            && TyCoercionStability::for_defined_ty(cx, ty, use_node.is_return()).is_deref_stable()
                         {
                             self.state = Some((
                                 State::ExplicitDeref { mutability: None },
@@ -301,7 +296,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                             ));
                         }
                     },
-                    (_, RefOp::Method { mutbl, is_ufcs })
+                    RefOp::Method { mutbl, is_ufcs }
                         if !is_lint_allowed(cx, EXPLICIT_DEREF_METHODS, expr.hir_id)
                             // Allow explicit deref in method chains. e.g. `foo.deref().bar()`
                             && (is_ufcs || !in_postfix_position(cx, expr)) =>
@@ -319,7 +314,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                             },
                         ));
                     },
-                    (Some(use_cx), RefOp::AddrOf(mutability)) => {
+                    RefOp::AddrOf(mutability) if use_cx.same_ctxt => {
                         // Find the number of times the borrow is auto-derefed.
                         let mut iter = use_cx.adjustments.iter();
                         let mut deref_count = 0usize;
@@ -338,10 +333,11 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                             };
                         };
 
-                        let stability = use_cx.node.defined_ty(cx).map_or(TyCoercionStability::None, |ty| {
-                            TyCoercionStability::for_defined_ty(cx, ty, use_cx.node.is_return())
+                        let use_node = use_cx.use_node(cx);
+                        let stability = use_node.defined_ty(cx).map_or(TyCoercionStability::None, |ty| {
+                            TyCoercionStability::for_defined_ty(cx, ty, use_node.is_return())
                         });
-                        let can_auto_borrow = match use_cx.node {
+                        let can_auto_borrow = match use_node {
                             ExprUseNode::FieldAccess(_)
                                 if !use_cx.moved_before_use && matches!(sub_expr.kind, ExprKind::Field(..)) =>
                             {
@@ -353,7 +349,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                                 // deref through `ManuallyDrop<_>` will not compile.
                                 !adjust_derefs_manually_drop(use_cx.adjustments, expr_ty)
                             },
-                            ExprUseNode::Callee | ExprUseNode::FieldAccess(_) => true,
+                            ExprUseNode::Callee | ExprUseNode::FieldAccess(_) if !use_cx.moved_before_use => true,
                             ExprUseNode::MethodArg(hir_id, _, 0) if !use_cx.moved_before_use => {
                                 // Check for calls to trait methods where the trait is implemented
                                 // on a reference.
@@ -363,9 +359,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                                 //   priority.
                                 if let Some(fn_id) = typeck.type_dependent_def_id(hir_id)
                                     && let Some(trait_id) = cx.tcx.trait_of_item(fn_id)
-                                    && let arg_ty = cx
-                                        .tcx
-                                        .erase_regions(use_cx.adjustments.last().map_or(expr_ty, |a| a.target))
+                                    && let arg_ty = cx.tcx.erase_regions(adjusted_ty)
                                     && let ty::Ref(_, sub_ty, _) = *arg_ty.kind()
                                     && let args =
                                         typeck.node_args_opt(hir_id).map(|args| &args[1..]).unwrap_or_default()
@@ -443,7 +437,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                                     count: deref_count - required_refs,
                                     msg,
                                     stability,
-                                    for_field_access: if let ExprUseNode::FieldAccess(name) = use_cx.node
+                                    for_field_access: if let ExprUseNode::FieldAccess(name) = use_node
                                         && !use_cx.moved_before_use
                                     {
                                         Some(name.name)
@@ -453,7 +447,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                                 }),
                                 StateData {
                                     first_expr: expr,
-                                    adjusted_ty: use_cx.adjustments.last().map_or(expr_ty, |a| a.target),
+                                    adjusted_ty,
                                 },
                             ));
                         } else if stability.is_deref_stable()
@@ -465,12 +459,12 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
                                 State::Borrow { mutability },
                                 StateData {
                                     first_expr: expr,
-                                    adjusted_ty: use_cx.adjustments.last().map_or(expr_ty, |a| a.target),
+                                    adjusted_ty,
                                 },
                             ));
                         }
                     },
-                    (None, _) | (_, RefOp::Method { .. }) => (),
+                    _ => {},
                 }
             },
             (
diff --git a/clippy_lints/src/needless_borrows_for_generic_args.rs b/clippy_lints/src/needless_borrows_for_generic_args.rs
index 4f99eaa40c29..9c3ead855a7a 100644
--- a/clippy_lints/src/needless_borrows_for_generic_args.rs
+++ b/clippy_lints/src/needless_borrows_for_generic_args.rs
@@ -80,11 +80,13 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowsForGenericArgs<'tcx> {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         if matches!(expr.kind, ExprKind::AddrOf(..))
             && !expr.span.from_expansion()
-            && let Some(use_cx) = expr_use_ctxt(cx, expr)
+            && let use_cx = expr_use_ctxt(cx, expr)
+            && use_cx.same_ctxt
             && !use_cx.is_ty_unified
-            && let Some(DefinedTy::Mir(ty)) = use_cx.node.defined_ty(cx)
+            && let use_node = use_cx.use_node(cx)
+            && let Some(DefinedTy::Mir(ty)) = use_node.defined_ty(cx)
             && let ty::Param(ty) = *ty.value.skip_binder().kind()
-            && let Some((hir_id, fn_id, i)) = match use_cx.node {
+            && let Some((hir_id, fn_id, i)) = match use_node {
                 ExprUseNode::MethodArg(_, _, 0) => None,
                 ExprUseNode::MethodArg(hir_id, None, i) => cx
                     .typeck_results()
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
index 7dc341ec8d71..fda870f435a5 100644
--- a/clippy_utils/src/lib.rs
+++ b/clippy_utils/src/lib.rs
@@ -1,6 +1,7 @@
 #![feature(array_chunks)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
+#![feature(exhaustive_patterns)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(lint_reasons)]
@@ -2664,13 +2665,80 @@ pub enum DefinedTy<'tcx> {
 /// The context an expressions value is used in.
 pub struct ExprUseCtxt<'tcx> {
     /// The parent node which consumes the value.
-    pub node: ExprUseNode<'tcx>,
+    pub node: Node<'tcx>,
+    /// The child id of the node the value came from.
+    pub child_id: HirId,
     /// Any adjustments applied to the type.
     pub adjustments: &'tcx [Adjustment<'tcx>],
-    /// Whether or not the type must unify with another code path.
+    /// Whether the type must unify with another code path.
     pub is_ty_unified: bool,
-    /// Whether or not the value will be moved before it's used.
+    /// Whether the value will be moved before it's used.
     pub moved_before_use: bool,
+    /// Whether the use site has the same `SyntaxContext` as the value.
+    pub same_ctxt: bool,
+}
+impl<'tcx> ExprUseCtxt<'tcx> {
+    pub fn use_node(&self, cx: &LateContext<'tcx>) -> ExprUseNode<'tcx> {
+        match self.node {
+            Node::LetStmt(l) => ExprUseNode::LetStmt(l),
+            Node::ExprField(field) => ExprUseNode::Field(field),
+
+            Node::Item(&Item {
+                kind: ItemKind::Static(..) | ItemKind::Const(..),
+                owner_id,
+                ..
+            })
+            | Node::TraitItem(&TraitItem {
+                kind: TraitItemKind::Const(..),
+                owner_id,
+                ..
+            })
+            | Node::ImplItem(&ImplItem {
+                kind: ImplItemKind::Const(..),
+                owner_id,
+                ..
+            }) => ExprUseNode::ConstStatic(owner_id),
+
+            Node::Item(&Item {
+                kind: ItemKind::Fn(..),
+                owner_id,
+                ..
+            })
+            | Node::TraitItem(&TraitItem {
+                kind: TraitItemKind::Fn(..),
+                owner_id,
+                ..
+            })
+            | Node::ImplItem(&ImplItem {
+                kind: ImplItemKind::Fn(..),
+                owner_id,
+                ..
+            }) => ExprUseNode::Return(owner_id),
+
+            Node::Expr(use_expr) => match use_expr.kind {
+                ExprKind::Ret(_) => ExprUseNode::Return(OwnerId {
+                    def_id: cx.tcx.hir().body_owner_def_id(cx.enclosing_body.unwrap()),
+                }),
+
+                ExprKind::Closure(closure) => ExprUseNode::Return(OwnerId { def_id: closure.def_id }),
+                ExprKind::Call(func, args) => match args.iter().position(|arg| arg.hir_id == self.child_id) {
+                    Some(i) => ExprUseNode::FnArg(func, i),
+                    None => ExprUseNode::Callee,
+                },
+                ExprKind::MethodCall(name, _, args, _) => ExprUseNode::MethodArg(
+                    use_expr.hir_id,
+                    name.args,
+                    args.iter()
+                        .position(|arg| arg.hir_id == self.child_id)
+                        .map_or(0, |i| i + 1),
+                ),
+                ExprKind::Field(_, name) => ExprUseNode::FieldAccess(name),
+                ExprKind::AddrOf(kind, mutbl, _) => ExprUseNode::AddrOf(kind, mutbl),
+                _ => ExprUseNode::Other,
+            },
+            _ => ExprUseNode::Other,
+        }
+    }
 }
 
 /// The node which consumes a value.
@@ -2691,7 +2759,8 @@ pub enum ExprUseNode<'tcx> {
     Callee,
     /// Access of a field.
     FieldAccess(Ident),
-    Expr,
+    /// Borrow expression.
+    AddrOf(ast::BorrowKind, Mutability),
     Other,
 }
 impl<'tcx> ExprUseNode<'tcx> {
@@ -2768,26 +2837,25 @@ impl<'tcx> ExprUseNode<'tcx> {
                 let sig = cx.tcx.fn_sig(id).skip_binder();
                 Some(DefinedTy::Mir(cx.tcx.param_env(id).and(sig.input(i))))
             },
-            Self::LetStmt(_) | Self::FieldAccess(..) | Self::Callee | Self::Expr | Self::Other => None,
+            Self::LetStmt(_) | Self::FieldAccess(..) | Self::Callee | Self::Other | Self::AddrOf(..) => None,
         }
     }
 }
 
 /// Gets the context an expression's value is used in.
-pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Option<ExprUseCtxt<'tcx>> {
+pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> ExprUseCtxt<'tcx> {
     let mut adjustments = [].as_slice();
     let mut is_ty_unified = false;
     let mut moved_before_use = false;
+    let mut same_ctxt = true;
     let ctxt = e.span.ctxt();
-    walk_to_expr_usage(cx, e, &mut |parent_id, parent, child_id| {
+    let node = walk_to_expr_usage(cx, e, &mut |parent_id, parent, child_id| -> ControlFlow<!> {
         if adjustments.is_empty()
             && let Node::Expr(e) = cx.tcx.hir_node(child_id)
         {
             adjustments = cx.typeck_results().expr_adjustments(e);
         }
-        if cx.tcx.hir().span(parent_id).ctxt() != ctxt {
-            return ControlFlow::Break(());
-        }
+        same_ctxt &= cx.tcx.hir().span(parent_id).ctxt() == ctxt;
         if let Node::Expr(e) = parent {
             match e.kind {
                 ExprKind::If(e, _, _) | ExprKind::Match(e, _, _) if e.hir_id != child_id => {
@@ -2803,71 +2871,25 @@ pub fn expr_use_ctxt<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> Optio
             }
         }
         ControlFlow::Continue(())
-    })?
-    .continue_value()
-    .map(|(use_node, child_id)| {
-        let node = match use_node {
-            Node::LetStmt(l) => ExprUseNode::LetStmt(l),
-            Node::ExprField(field) => ExprUseNode::Field(field),
-
-            Node::Item(&Item {
-                kind: ItemKind::Static(..) | ItemKind::Const(..),
-                owner_id,
-                ..
-            })
-            | Node::TraitItem(&TraitItem {
-                kind: TraitItemKind::Const(..),
-                owner_id,
-                ..
-            })
-            | Node::ImplItem(&ImplItem {
-                kind: ImplItemKind::Const(..),
-                owner_id,
-                ..
-            }) => ExprUseNode::ConstStatic(owner_id),
-
-            Node::Item(&Item {
-                kind: ItemKind::Fn(..),
-                owner_id,
-                ..
-            })
-            | Node::TraitItem(&TraitItem {
-                kind: TraitItemKind::Fn(..),
-                owner_id,
-                ..
-            })
-            | Node::ImplItem(&ImplItem {
-                kind: ImplItemKind::Fn(..),
-                owner_id,
-                ..
-            }) => ExprUseNode::Return(owner_id),
-
-            Node::Expr(use_expr) => match use_expr.kind {
-                ExprKind::Ret(_) => ExprUseNode::Return(OwnerId {
-                    def_id: cx.tcx.hir().body_owner_def_id(cx.enclosing_body.unwrap()),
-                }),
-                ExprKind::Closure(closure) => ExprUseNode::Return(OwnerId { def_id: closure.def_id }),
-                ExprKind::Call(func, args) => match args.iter().position(|arg| arg.hir_id == child_id) {
-                    Some(i) => ExprUseNode::FnArg(func, i),
-                    None => ExprUseNode::Callee,
-                },
-                ExprKind::MethodCall(name, _, args, _) => ExprUseNode::MethodArg(
-                    use_expr.hir_id,
-                    name.args,
-                    args.iter().position(|arg| arg.hir_id == child_id).map_or(0, |i| i + 1),
-                ),
-                ExprKind::Field(child, name) if child.hir_id == e.hir_id => ExprUseNode::FieldAccess(name),
-                _ => ExprUseNode::Expr,
-            },
-            _ => ExprUseNode::Other,
-        };
-        ExprUseCtxt {
+    });
+    match node {
+        Some(ControlFlow::Continue((node, child_id))) => ExprUseCtxt {
             node,
+            child_id,
             adjustments,
             is_ty_unified,
             moved_before_use,
-        }
-    })
+            same_ctxt,
+        },
+        None => ExprUseCtxt {
+            node: Node::Crate(cx.tcx.hir().root_module()),
+            child_id: HirId::INVALID,
+            adjustments: &[],
+            is_ty_unified: true,
+            moved_before_use: true,
+            same_ctxt: false,
+        },
+    }
 }
 
 /// Tokenizes the input while keeping the text associated with each token.

From 22710f33a8ad99be51bb69f91339f8d815bd9e92 Mon Sep 17 00:00:00 2001
From: Jason Newcomb <jsnewcomb@pm.me>
Date: Mon, 12 Feb 2024 18:33:22 -0500
Subject: [PATCH 54/56] Add lint `manual_inspect`

---
 CHANGELOG.md                               |   1 +
 clippy_config/src/msrvs.rs                 |   2 +-
 clippy_lints/src/declared_lints.rs         |   1 +
 clippy_lints/src/methods/manual_inspect.rs | 233 +++++++++++++++++++++
 clippy_lints/src/methods/mod.rs            |  24 +++
 clippy_utils/src/source.rs                 |  27 ++-
 clippy_utils/src/ty.rs                     |  14 ++
 tests/ui/copy_iterator.rs                  |   1 +
 tests/ui/copy_iterator.stderr              |   2 +-
 tests/ui/manual_inspect.fixed              | 174 +++++++++++++++
 tests/ui/manual_inspect.rs                 | 186 ++++++++++++++++
 tests/ui/manual_inspect.stderr             | 182 ++++++++++++++++
 12 files changed, 844 insertions(+), 3 deletions(-)
 create mode 100644 clippy_lints/src/methods/manual_inspect.rs
 create mode 100644 tests/ui/manual_inspect.fixed
 create mode 100644 tests/ui/manual_inspect.rs
 create mode 100644 tests/ui/manual_inspect.stderr

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4de3124bd3da..3973edddb6d6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5521,6 +5521,7 @@ Released 2018-09-13
 [`manual_find_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_find_map
 [`manual_flatten`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_flatten
 [`manual_hash_one`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_hash_one
+[`manual_inspect`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_inspect
 [`manual_instant_elapsed`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_instant_elapsed
 [`manual_is_ascii_check`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_ascii_check
 [`manual_is_finite`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_is_finite
diff --git a/clippy_config/src/msrvs.rs b/clippy_config/src/msrvs.rs
index a3e7d0c3fa5f..5327a1256474 100644
--- a/clippy_config/src/msrvs.rs
+++ b/clippy_config/src/msrvs.rs
@@ -18,7 +18,7 @@ macro_rules! msrv_aliases {
 // names may refer to stabilized feature flags or library items
 msrv_aliases! {
     1,77,0 { C_STR_LITERALS }
-    1,76,0 { PTR_FROM_REF }
+    1,76,0 { PTR_FROM_REF, OPTION_RESULT_INSPECT }
     1,71,0 { TUPLE_ARRAY_CONVERSIONS, BUILD_HASHER_HASH_ONE }
     1,70,0 { OPTION_RESULT_IS_VARIANT_AND, BINARY_HEAP_RETAIN }
     1,68,0 { PATH_MAIN_SEPARATOR_STR }
diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs
index 88986f9ad727..8abe5d47b65e 100644
--- a/clippy_lints/src/declared_lints.rs
+++ b/clippy_lints/src/declared_lints.rs
@@ -403,6 +403,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::methods::MANUAL_C_STR_LITERALS_INFO,
     crate::methods::MANUAL_FILTER_MAP_INFO,
     crate::methods::MANUAL_FIND_MAP_INFO,
+    crate::methods::MANUAL_INSPECT_INFO,
     crate::methods::MANUAL_IS_VARIANT_AND_INFO,
     crate::methods::MANUAL_NEXT_BACK_INFO,
     crate::methods::MANUAL_OK_OR_INFO,
diff --git a/clippy_lints/src/methods/manual_inspect.rs b/clippy_lints/src/methods/manual_inspect.rs
new file mode 100644
index 000000000000..2f9b951c6a76
--- /dev/null
+++ b/clippy_lints/src/methods/manual_inspect.rs
@@ -0,0 +1,233 @@
+use clippy_config::msrvs::{self, Msrv};
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::source::{get_source_text, with_leading_whitespace, SpanRange};
+use clippy_utils::ty::get_field_by_name;
+use clippy_utils::visitors::{for_each_expr, for_each_expr_without_closures};
+use clippy_utils::{expr_use_ctxt, is_diag_item_method, is_diag_trait_item, path_to_local_id, ExprUseNode};
+use core::ops::ControlFlow;
+use rustc_errors::Applicability;
+use rustc_hir::{BindingMode, BorrowKind, ByRef, ClosureKind, Expr, ExprKind, Mutability, Node, PatKind};
+use rustc_lint::LateContext;
+use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
+use rustc_span::{sym, BytePos, Span, Symbol, DUMMY_SP};
+
+use super::MANUAL_INSPECT;
+
+#[expect(clippy::too_many_lines)]
+pub(crate) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, arg: &Expr<'_>, name: &str, name_span: Span, msrv: &Msrv) {
+    if let ExprKind::Closure(c) = arg.kind
+        && matches!(c.kind, ClosureKind::Closure)
+        && let typeck = cx.typeck_results()
+        && let Some(fn_id) = typeck.type_dependent_def_id(expr.hir_id)
+        && (is_diag_trait_item(cx, fn_id, sym::Iterator)
+            || (msrv.meets(msrvs::OPTION_RESULT_INSPECT)
+                && (is_diag_item_method(cx, fn_id, sym::Option) || is_diag_item_method(cx, fn_id, sym::Result))))
+        && let body = cx.tcx.hir().body(c.body)
+        && let [param] = body.params
+        && let PatKind::Binding(BindingMode(ByRef::No, Mutability::Not), arg_id, _, None) = param.pat.kind
+        && let arg_ty = typeck.node_type(arg_id)
+        && let ExprKind::Block(block, _) = body.value.kind
+        && let Some(final_expr) = block.expr
+        && !block.stmts.is_empty()
+        && path_to_local_id(final_expr, arg_id)
+        && typeck.expr_adjustments(final_expr).is_empty()
+    {
+        let mut requires_copy = false;
+        let mut requires_deref = false;
+
+        // The number of unprocessed return expressions.
+        let mut ret_count = 0u32;
+
+        // The uses for which processing is delayed until after the visitor.
+        let mut delayed = vec![];
+
+        let ctxt = arg.span.ctxt();
+        let can_lint = for_each_expr_without_closures(block.stmts, |e| {
+            if let ExprKind::Closure(c) = e.kind {
+                // Nested closures don't need to treat returns specially.
+                let _: Option<!> = for_each_expr(cx, cx.tcx.hir().body(c.body).value, |e| {
+                    if path_to_local_id(e, arg_id) {
+                        let (kind, same_ctxt) = check_use(cx, e);
+                        match (kind, same_ctxt && e.span.ctxt() == ctxt) {
+                            (_, false) | (UseKind::Deref | UseKind::Return(..), true) => {
+                                requires_copy = true;
+                                requires_deref = true;
+                            },
+                            (UseKind::AutoBorrowed, true) => {},
+                            (UseKind::WillAutoDeref, true) => {
+                                requires_copy = true;
+                            },
+                            (kind, true) => delayed.push(kind),
+                        }
+                    }
+                    ControlFlow::Continue(())
+                });
+            } else if matches!(e.kind, ExprKind::Ret(_)) {
+                ret_count += 1;
+            } else if path_to_local_id(e, arg_id) {
+                let (kind, same_ctxt) = check_use(cx, e);
+                match (kind, same_ctxt && e.span.ctxt() == ctxt) {
+                    (UseKind::Return(..), false) => {
+                        return ControlFlow::Break(());
+                    },
+                    (_, false) | (UseKind::Deref, true) => {
+                        requires_copy = true;
+                        requires_deref = true;
+                    },
+                    (UseKind::AutoBorrowed, true) => {},
+                    (UseKind::WillAutoDeref, true) => {
+                        requires_copy = true;
+                    },
+                    (kind @ UseKind::Return(_), true) => {
+                        ret_count -= 1;
+                        delayed.push(kind);
+                    },
+                    (kind, true) => delayed.push(kind),
+                }
+            }
+            ControlFlow::Continue(())
+        })
+        .is_none();
+
+        if ret_count != 0 {
+            // A return expression that didn't return the original value was found.
+            return;
+        }
+
+        let mut edits = Vec::with_capacity(delayed.len() + 3);
+        let mut addr_of_edits = Vec::with_capacity(delayed.len());
+        for x in delayed {
+            match x {
+                UseKind::Return(s) => edits.push((with_leading_whitespace(cx, s).set_span_pos(s), String::new())),
+                UseKind::Borrowed(s) => {
+                    if let Some(src) = get_source_text(cx, s)
+                        && let Some(src) = src.as_str()
+                        && let trim_src = src.trim_start_matches([' ', '\t', '\n', '\r', '('])
+                        && trim_src.starts_with('&')
+                    {
+                        let range = s.into_range();
+                        #[expect(clippy::cast_possible_truncation)]
+                        let start = BytePos(range.start.0 + (src.len() - trim_src.len()) as u32);
+                        addr_of_edits.push(((start..BytePos(start.0 + 1)).set_span_pos(s), String::new()));
+                    } else {
+                        requires_copy = true;
+                        requires_deref = true;
+                    }
+                },
+                UseKind::FieldAccess(name, e) => {
+                    let Some(mut ty) = get_field_by_name(cx.tcx, arg_ty.peel_refs(), name) else {
+                        requires_copy = true;
+                        continue;
+                    };
+                    let mut prev_expr = e;
+
+                    for (_, parent) in cx.tcx.hir().parent_iter(e.hir_id) {
+                        if let Node::Expr(e) = parent {
+                            match e.kind {
+                                ExprKind::Field(_, name)
+                                    if let Some(fty) = get_field_by_name(cx.tcx, ty.peel_refs(), name.name) =>
+                                {
+                                    ty = fty;
+                                    prev_expr = e;
+                                    continue;
+                                },
+                                ExprKind::AddrOf(BorrowKind::Ref, ..) => break,
+                                _ if matches!(
+                                    typeck.expr_adjustments(prev_expr).first(),
+                                    Some(Adjustment {
+                                        kind: Adjust::Borrow(AutoBorrow::Ref(_, AutoBorrowMutability::Not))
+                                            | Adjust::Deref(_),
+                                        ..
+                                    })
+                                ) =>
+                                {
+                                    break;
+                                },
+                                _ => {},
+                            }
+                        }
+                        requires_copy |= !ty.is_copy_modulo_regions(cx.tcx, cx.param_env);
+                        break;
+                    }
+                },
+                // Already processed uses.
+                UseKind::AutoBorrowed | UseKind::WillAutoDeref | UseKind::Deref => {},
+            }
+        }
+
+        if can_lint
+            && (!requires_copy || arg_ty.is_copy_modulo_regions(cx.tcx, cx.param_env))
+            // This case could be handled, but a fair bit of care would need to be taken.
+            && (!requires_deref || arg_ty.is_freeze(cx.tcx, cx.param_env))
+        {
+            if requires_deref {
+                edits.push((param.span.shrink_to_lo(), "&".into()));
+            } else {
+                edits.extend(addr_of_edits);
+            }
+            edits.push((
+                name_span,
+                String::from(match name {
+                    "map" => "inspect",
+                    "map_err" => "inspect_err",
+                    _ => return,
+                }),
+            ));
+            edits.push((
+                with_leading_whitespace(cx, final_expr.span).set_span_pos(final_expr.span),
+                String::new(),
+            ));
+            let app = if edits.iter().any(|(s, _)| s.from_expansion()) {
+                Applicability::MaybeIncorrect
+            } else {
+                Applicability::MachineApplicable
+            };
+            span_lint_and_then(cx, MANUAL_INSPECT, name_span, "", |diag| {
+                diag.multipart_suggestion("try", edits, app);
+            });
+        }
+    }
+}
+
+enum UseKind<'tcx> {
+    AutoBorrowed,
+    WillAutoDeref,
+    Deref,
+    Return(Span),
+    Borrowed(Span),
+    FieldAccess(Symbol, &'tcx Expr<'tcx>),
+}
+
+/// Checks how the value is used, and whether it was used in the same `SyntaxContext`.
+fn check_use<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> (UseKind<'tcx>, bool) {
+    let use_cx = expr_use_ctxt(cx, e);
+    if use_cx
+        .adjustments
+        .first()
+        .is_some_and(|a| matches!(a.kind, Adjust::Deref(_)))
+    {
+        return (UseKind::AutoBorrowed, use_cx.same_ctxt);
+    }
+    let res = match use_cx.use_node(cx) {
+        ExprUseNode::Return(_) => {
+            if let ExprKind::Ret(Some(e)) = use_cx.node.expect_expr().kind {
+                UseKind::Return(e.span)
+            } else {
+                return (UseKind::Return(DUMMY_SP), false);
+            }
+        },
+        ExprUseNode::FieldAccess(name) => UseKind::FieldAccess(name.name, use_cx.node.expect_expr()),
+        ExprUseNode::Callee | ExprUseNode::MethodArg(_, _, 0)
+            if use_cx
+                .adjustments
+                .first()
+                .is_some_and(|a| matches!(a.kind, Adjust::Borrow(AutoBorrow::Ref(_, AutoBorrowMutability::Not)))) =>
+        {
+            UseKind::AutoBorrowed
+        },
+        ExprUseNode::Callee | ExprUseNode::MethodArg(_, _, 0) => UseKind::WillAutoDeref,
+        ExprUseNode::AddrOf(BorrowKind::Ref, _) => UseKind::Borrowed(use_cx.node.expect_expr().span),
+        _ => UseKind::Deref,
+    };
+    (res, use_cx.same_ctxt)
+}
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index 6200716afbe9..01438b8e8db0 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -53,6 +53,7 @@ mod iter_with_drain;
 mod iterator_step_by_zero;
 mod join_absolute_paths;
 mod manual_c_str_literals;
+mod manual_inspect;
 mod manual_is_variant_and;
 mod manual_next_back;
 mod manual_ok_or;
@@ -4079,6 +4080,27 @@ declare_clippy_lint! {
     "is_ascii() called on a char iterator"
 }
 
+declare_clippy_lint! {
+    /// ### What it does
+    /// Checks for uses of `map` which return the original item.
+    ///
+    /// ### Why is this bad?
+    /// `inspect` is both clearer in intent and shorter.
+    ///
+    /// ### Example
+    /// ```no_run
+    /// let x = Some(0).map(|x| { println!("{x}"); x });
+    /// ```
+    /// Use instead:
+    /// ```no_run
+    /// let x = Some(0).inspect(|x| println!("{x}"));
+    /// ```
+    #[clippy::version = "1.78.0"]
+    pub MANUAL_INSPECT,
+    complexity,
+    "use of `map` returning the original item"
+}
+
 pub struct Methods {
     avoid_breaking_exported_api: bool,
     msrv: Msrv,
@@ -4244,6 +4266,7 @@ impl_lint_pass!(Methods => [
     MANUAL_C_STR_LITERALS,
     UNNECESSARY_GET_THEN_CHECK,
     NEEDLESS_CHARACTER_ITERATION,
+    MANUAL_INSPECT,
 ]);
 
 /// Extracts a method call name, args, and `Span` of the method name.
@@ -4747,6 +4770,7 @@ impl Methods {
                         }
                     }
                     map_identity::check(cx, expr, recv, m_arg, name, span);
+                    manual_inspect::check(cx, expr, m_arg, name, span, &self.msrv);
                 },
                 ("map_or", [def, map]) => {
                     option_map_or_none::check(cx, expr, recv, def, map);
diff --git a/clippy_utils/src/source.rs b/clippy_utils/src/source.rs
index b7ff7ebe9105..69b122cbfada 100644
--- a/clippy_utils/src/source.rs
+++ b/clippy_utils/src/source.rs
@@ -14,8 +14,17 @@ use std::borrow::Cow;
 use std::ops::Range;
 
 /// A type which can be converted to the range portion of a `Span`.
-pub trait SpanRange {
+pub trait SpanRange: Sized {
     fn into_range(self) -> Range<BytePos>;
+    fn set_span_pos(self, sp: Span) -> Span {
+        let range = self.into_range();
+        SpanData {
+            lo: range.start,
+            hi: range.end,
+            ..sp.data()
+        }
+        .span()
+    }
 }
 impl SpanRange for Span {
     fn into_range(self) -> Range<BytePos> {
@@ -61,6 +70,22 @@ pub fn get_source_text(cx: &impl LintContext, sp: impl SpanRange) -> Option<Sour
     f(cx.sess().source_map(), sp.into_range())
 }
 
+pub fn with_leading_whitespace(cx: &impl LintContext, sp: impl SpanRange) -> Range<BytePos> {
+    #[expect(clippy::needless_pass_by_value, clippy::cast_possible_truncation)]
+    fn f(src: SourceFileRange, sp: Range<BytePos>) -> Range<BytePos> {
+        let Some(text) = &src.sf.src else {
+            return sp;
+        };
+        let len = src.range.start - text[..src.range.start].trim_end().len();
+        BytePos(sp.start.0 - len as u32)..sp.end
+    }
+    let sp = sp.into_range();
+    match get_source_text(cx, sp.clone()) {
+        Some(src) => f(src, sp),
+        None => sp,
+    }
+}
+
 /// Like `snippet_block`, but add braces if the expr is not an `ExprKind::Block`.
 pub fn expr_block<T: LintContext>(
     cx: &T,
diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs
index 7d4332a3d9de..3f5ed73c3ef8 100644
--- a/clippy_utils/src/ty.rs
+++ b/clippy_utils/src/ty.rs
@@ -1349,3 +1349,17 @@ pub fn get_adt_inherent_method<'a>(cx: &'a LateContext<'_>, ty: Ty<'_>, method_n
         None
     }
 }
+
+/// Get's the type of a field by name.
+pub fn get_field_by_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, name: Symbol) -> Option<Ty<'tcx>> {
+    match *ty.kind() {
+        ty::Adt(def, args) if def.is_union() || def.is_struct() => def
+            .non_enum_variant()
+            .fields
+            .iter()
+            .find(|f| f.name == name)
+            .map(|f| f.ty(tcx, args)),
+        ty::Tuple(args) => name.as_str().parse::<usize>().ok().and_then(|i| args.get(i).copied()),
+        _ => None,
+    }
+}
diff --git a/tests/ui/copy_iterator.rs b/tests/ui/copy_iterator.rs
index c0e5fc3e4467..ea3a4face93f 100644
--- a/tests/ui/copy_iterator.rs
+++ b/tests/ui/copy_iterator.rs
@@ -1,4 +1,5 @@
 #![warn(clippy::copy_iterator)]
+#![allow(clippy::manual_inspect)]
 
 #[derive(Copy, Clone)]
 struct Countdown(u8);
diff --git a/tests/ui/copy_iterator.stderr b/tests/ui/copy_iterator.stderr
index 533bddaadb5e..990b1ce628de 100644
--- a/tests/ui/copy_iterator.stderr
+++ b/tests/ui/copy_iterator.stderr
@@ -1,5 +1,5 @@
 error: you are implementing `Iterator` on a `Copy` type
-  --> tests/ui/copy_iterator.rs:6:1
+  --> tests/ui/copy_iterator.rs:7:1
    |
 LL | / impl Iterator for Countdown {
 LL | |
diff --git a/tests/ui/manual_inspect.fixed b/tests/ui/manual_inspect.fixed
new file mode 100644
index 000000000000..0e1b8fe3edb5
--- /dev/null
+++ b/tests/ui/manual_inspect.fixed
@@ -0,0 +1,174 @@
+#![warn(clippy::manual_inspect)]
+#![allow(clippy::no_effect, clippy::op_ref)]
+
+fn main() {
+    let _ = Some(0).inspect(|&x| {
+        println!("{}", x);
+    });
+
+    let _ = Some(0).inspect(|&x| {
+        println!("{x}");
+    });
+
+    let _ = Some(0).inspect(|&x| {
+        println!("{}", x * 5 + 1);
+    });
+
+    let _ = Some(0).inspect(|&x| {
+        if x == 0 {
+            panic!();
+        }
+    });
+
+    let _ = Some(0).inspect(|&x| {
+        if &x == &0 {
+            let _y = x;
+            panic!();
+        }
+    });
+
+    let _ = Some(0).map(|x| {
+        let y = x + 1;
+        if y > 5 {
+            return y;
+        }
+        x
+    });
+
+    {
+        #[derive(PartialEq)]
+        struct Foo(i32);
+
+        let _ = Some(Foo(0)).map(|x| {
+            if x == Foo(0) {
+                panic!();
+            }
+            x
+        });
+
+        let _ = Some(Foo(0)).map(|x| {
+            if &x == &Foo(0) {
+                let _y = x;
+                panic!();
+            }
+            x
+        });
+    }
+
+    {
+        macro_rules! maybe_ret {
+            ($e:expr) => {
+                if $e == 0 {
+                    return $e;
+                }
+            };
+        }
+
+        let _ = Some(0).map(|x| {
+            maybe_ret!(x);
+            x
+        });
+    }
+
+    let _ = Some((String::new(), 0u32)).inspect(|x| {
+        if x.1 == 0 {
+            let _x = x.1;
+            panic!();
+        }
+    });
+
+    let _ = Some((String::new(), 0u32)).map(|x| {
+        if x.1 == 0 {
+            let _x = x.0;
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some(String::new()).map(|x| {
+        if x.is_empty() {
+            let _ = || {
+                let _x = x;
+            };
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some(String::new()).inspect(|x| {
+        if x.is_empty() {
+            let _ = || {
+                let _x = x;
+            };
+            return;
+        }
+        println!("test");
+    });
+
+    let _ = Some(0).inspect(|&x| {
+        if x == 0 {
+            let _ = || {
+                let _x = x;
+            };
+            panic!();
+        }
+    });
+
+    {
+        use core::cell::Cell;
+        #[derive(Debug)]
+        struct Cell2(core::cell::Cell<u32>);
+
+        let _ = Some(Cell2(Cell::new(0u32))).inspect(|x| {
+            x.0.set(1);
+        });
+
+        let _ = Some(Cell2(Cell::new(0u32))).map(|x| {
+            let y = &x;
+            if x.0.get() == 0 {
+                y.0.set(1)
+            } else {
+                println!("{x:?}");
+            }
+            x
+        });
+    }
+
+    let _: Result<_, ()> = Ok(0).inspect(|&x| {
+        println!("{}", x);
+    });
+
+    let _: Result<(), _> = Err(0).inspect_err(|&x| {
+        println!("{}", x);
+    });
+
+    let _ = [0]
+        .into_iter()
+        .inspect(|&x| {
+            println!("{}", x);
+        })
+        .count();
+
+    {
+        struct S<T>(T);
+        impl<T> S<T> {
+            fn map<U>(self, f: impl FnOnce(T) -> U) -> S<U> {
+                S(f(self.0))
+            }
+
+            fn map_err<U>(self, f: impl FnOnce(T) -> U) -> S<U> {
+                S(f(self.0))
+            }
+        }
+
+        let _ = S(0).map(|x| {
+            println!("{}", x);
+            x
+        });
+
+        let _ = S(0).map_err(|x| {
+            println!("{}", x);
+            x
+        });
+    }
+}
diff --git a/tests/ui/manual_inspect.rs b/tests/ui/manual_inspect.rs
new file mode 100644
index 000000000000..94cdfe391400
--- /dev/null
+++ b/tests/ui/manual_inspect.rs
@@ -0,0 +1,186 @@
+#![warn(clippy::manual_inspect)]
+#![allow(clippy::no_effect, clippy::op_ref)]
+
+fn main() {
+    let _ = Some(0).map(|x| {
+        println!("{}", x);
+        x
+    });
+
+    let _ = Some(0).map(|x| {
+        println!("{x}");
+        x
+    });
+
+    let _ = Some(0).map(|x| {
+        println!("{}", x * 5 + 1);
+        x
+    });
+
+    let _ = Some(0).map(|x| {
+        if x == 0 {
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some(0).map(|x| {
+        if &x == &0 {
+            let _y = x;
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some(0).map(|x| {
+        let y = x + 1;
+        if y > 5 {
+            return y;
+        }
+        x
+    });
+
+    {
+        #[derive(PartialEq)]
+        struct Foo(i32);
+
+        let _ = Some(Foo(0)).map(|x| {
+            if x == Foo(0) {
+                panic!();
+            }
+            x
+        });
+
+        let _ = Some(Foo(0)).map(|x| {
+            if &x == &Foo(0) {
+                let _y = x;
+                panic!();
+            }
+            x
+        });
+    }
+
+    {
+        macro_rules! maybe_ret {
+            ($e:expr) => {
+                if $e == 0 {
+                    return $e;
+                }
+            };
+        }
+
+        let _ = Some(0).map(|x| {
+            maybe_ret!(x);
+            x
+        });
+    }
+
+    let _ = Some((String::new(), 0u32)).map(|x| {
+        if x.1 == 0 {
+            let _x = x.1;
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some((String::new(), 0u32)).map(|x| {
+        if x.1 == 0 {
+            let _x = x.0;
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some(String::new()).map(|x| {
+        if x.is_empty() {
+            let _ = || {
+                let _x = x;
+            };
+            panic!();
+        }
+        x
+    });
+
+    let _ = Some(String::new()).map(|x| {
+        if x.is_empty() {
+            let _ = || {
+                let _x = &x;
+            };
+            return x;
+        }
+        println!("test");
+        x
+    });
+
+    let _ = Some(0).map(|x| {
+        if x == 0 {
+            let _ = || {
+                let _x = x;
+            };
+            panic!();
+        }
+        x
+    });
+
+    {
+        use core::cell::Cell;
+        #[derive(Debug)]
+        struct Cell2(core::cell::Cell<u32>);
+
+        let _ = Some(Cell2(Cell::new(0u32))).map(|x| {
+            x.0.set(1);
+            x
+        });
+
+        let _ = Some(Cell2(Cell::new(0u32))).map(|x| {
+            let y = &x;
+            if x.0.get() == 0 {
+                y.0.set(1)
+            } else {
+                println!("{x:?}");
+            }
+            x
+        });
+    }
+
+    let _: Result<_, ()> = Ok(0).map(|x| {
+        println!("{}", x);
+        x
+    });
+
+    let _: Result<(), _> = Err(0).map_err(|x| {
+        println!("{}", x);
+        x
+    });
+
+    let _ = [0]
+        .into_iter()
+        .map(|x| {
+            println!("{}", x);
+            x
+        })
+        .count();
+
+    {
+        struct S<T>(T);
+        impl<T> S<T> {
+            fn map<U>(self, f: impl FnOnce(T) -> U) -> S<U> {
+                S(f(self.0))
+            }
+
+            fn map_err<U>(self, f: impl FnOnce(T) -> U) -> S<U> {
+                S(f(self.0))
+            }
+        }
+
+        let _ = S(0).map(|x| {
+            println!("{}", x);
+            x
+        });
+
+        let _ = S(0).map_err(|x| {
+            println!("{}", x);
+            x
+        });
+    }
+}
diff --git a/tests/ui/manual_inspect.stderr b/tests/ui/manual_inspect.stderr
new file mode 100644
index 000000000000..efdf115b84e5
--- /dev/null
+++ b/tests/ui/manual_inspect.stderr
@@ -0,0 +1,182 @@
+error: 
+  --> tests/ui/manual_inspect.rs:5:21
+   |
+LL |     let _ = Some(0).map(|x| {
+   |                     ^^^
+   |
+   = note: `-D clippy::manual-inspect` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::manual_inspect)]`
+help: try
+   |
+LL ~     let _ = Some(0).inspect(|&x| {
+LL ~         println!("{}", x);
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:10:21
+   |
+LL |     let _ = Some(0).map(|x| {
+   |                     ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some(0).inspect(|&x| {
+LL ~         println!("{x}");
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:15:21
+   |
+LL |     let _ = Some(0).map(|x| {
+   |                     ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some(0).inspect(|&x| {
+LL ~         println!("{}", x * 5 + 1);
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:20:21
+   |
+LL |     let _ = Some(0).map(|x| {
+   |                     ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some(0).inspect(|&x| {
+LL |         if x == 0 {
+LL |             panic!();
+LL ~         }
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:27:21
+   |
+LL |     let _ = Some(0).map(|x| {
+   |                     ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some(0).inspect(|&x| {
+LL |         if &x == &0 {
+LL |             let _y = x;
+LL |             panic!();
+LL ~         }
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:78:41
+   |
+LL |     let _ = Some((String::new(), 0u32)).map(|x| {
+   |                                         ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some((String::new(), 0u32)).inspect(|x| {
+LL |         if x.1 == 0 {
+LL |             let _x = x.1;
+LL |             panic!();
+LL ~         }
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:104:33
+   |
+LL |     let _ = Some(String::new()).map(|x| {
+   |                                 ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some(String::new()).inspect(|x| {
+LL |         if x.is_empty() {
+LL |             let _ = || {
+LL ~                 let _x = x;
+LL |             };
+LL ~             return;
+LL |         }
+LL ~         println!("test");
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:115:21
+   |
+LL |     let _ = Some(0).map(|x| {
+   |                     ^^^
+   |
+help: try
+   |
+LL ~     let _ = Some(0).inspect(|&x| {
+LL |         if x == 0 {
+ ...
+LL |             panic!();
+LL ~         }
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:130:46
+   |
+LL |         let _ = Some(Cell2(Cell::new(0u32))).map(|x| {
+   |                                              ^^^
+   |
+help: try
+   |
+LL ~         let _ = Some(Cell2(Cell::new(0u32))).inspect(|x| {
+LL ~             x.0.set(1);
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:146:34
+   |
+LL |     let _: Result<_, ()> = Ok(0).map(|x| {
+   |                                  ^^^
+   |
+help: try
+   |
+LL ~     let _: Result<_, ()> = Ok(0).inspect(|&x| {
+LL ~         println!("{}", x);
+   |
+
+error: 
+  --> tests/ui/manual_inspect.rs:151:35
+   |
+LL |     let _: Result<(), _> = Err(0).map_err(|x| {
+   |                                   ^^^^^^^
+   |
+help: try
+   |
+LL ~     let _: Result<(), _> = Err(0).inspect_err(|&x| {
+LL ~         println!("{}", x);
+   |
+
+error: this call to `map()` won't have an effect on the call to `count()`
+  --> tests/ui/manual_inspect.rs:156:13
+   |
+LL |       let _ = [0]
+   |  _____________^
+LL | |         .into_iter()
+LL | |         .map(|x| {
+LL | |             println!("{}", x);
+LL | |             x
+LL | |         })
+LL | |         .count();
+   | |________________^
+   |
+   = help: make sure you did not confuse `map` with `filter`, `for_each` or `inspect`
+   = note: `-D clippy::suspicious-map` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::suspicious_map)]`
+
+error: 
+  --> tests/ui/manual_inspect.rs:158:10
+   |
+LL |         .map(|x| {
+   |          ^^^
+   |
+help: try
+   |
+LL ~         .inspect(|&x| {
+LL ~             println!("{}", x);
+   |
+
+error: aborting due to 13 previous errors
+

From f09650b347f6f0d38747662db4382729cd058247 Mon Sep 17 00:00:00 2001
From: Jason Newcomb <jsnewcomb@pm.me>
Date: Sun, 16 Jun 2024 14:38:58 -0400
Subject: [PATCH 55/56] Use symbols when raising range expressions.

---
 clippy_utils/src/higher.rs | 63 ++++++++++++++++++++------------------
 1 file changed, 34 insertions(+), 29 deletions(-)

diff --git a/clippy_utils/src/higher.rs b/clippy_utils/src/higher.rs
index 801a98521590..277ba8427e05 100644
--- a/clippy_utils/src/higher.rs
+++ b/clippy_utils/src/higher.rs
@@ -218,51 +218,56 @@ pub struct Range<'a> {
 
 impl<'a> Range<'a> {
     /// Higher a `hir` range to something similar to `ast::ExprKind::Range`.
+    #[allow(clippy::similar_names)]
     pub fn hir(expr: &'a Expr<'_>) -> Option<Range<'a>> {
-        /// Finds the field named `name` in the field. Always return `Some` for
-        /// convenience.
-        fn get_field<'c>(name: &str, fields: &'c [hir::ExprField<'_>]) -> Option<&'c Expr<'c>> {
-            let expr = &fields.iter().find(|field| field.ident.name.as_str() == name)?.expr;
-            Some(expr)
-        }
-
         match expr.kind {
-            ExprKind::Call(path, args)
+            ExprKind::Call(path, [arg1, arg2])
                 if matches!(
                     path.kind,
                     ExprKind::Path(QPath::LangItem(hir::LangItem::RangeInclusiveNew, ..))
                 ) =>
             {
                 Some(Range {
-                    start: Some(&args[0]),
-                    end: Some(&args[1]),
+                    start: Some(arg1),
+                    end: Some(arg2),
                     limits: ast::RangeLimits::Closed,
                 })
             },
-            ExprKind::Struct(path, fields, None) => match &path {
-                QPath::LangItem(hir::LangItem::RangeFull, ..) => Some(Range {
+            ExprKind::Struct(path, fields, None) => match (path, fields) {
+                (QPath::LangItem(hir::LangItem::RangeFull, ..), []) => Some(Range {
                     start: None,
                     end: None,
                     limits: ast::RangeLimits::HalfOpen,
                 }),
-                QPath::LangItem(hir::LangItem::RangeFrom, ..) => Some(Range {
-                    start: Some(get_field("start", fields)?),
-                    end: None,
-                    limits: ast::RangeLimits::HalfOpen,
-                }),
-                QPath::LangItem(hir::LangItem::Range, ..) => Some(Range {
-                    start: Some(get_field("start", fields)?),
-                    end: Some(get_field("end", fields)?),
-                    limits: ast::RangeLimits::HalfOpen,
-                }),
-                QPath::LangItem(hir::LangItem::RangeToInclusive, ..) => Some(Range {
-                    start: None,
-                    end: Some(get_field("end", fields)?),
-                    limits: ast::RangeLimits::Closed,
-                }),
-                QPath::LangItem(hir::LangItem::RangeTo, ..) => Some(Range {
+                (QPath::LangItem(hir::LangItem::RangeFrom, ..), [field]) if field.ident.name == sym::start => {
+                    Some(Range {
+                        start: Some(field.expr),
+                        end: None,
+                        limits: ast::RangeLimits::HalfOpen,
+                    })
+                },
+                (QPath::LangItem(hir::LangItem::Range, ..), [field1, field2]) => {
+                    let (start, end) = match (field1.ident.name, field2.ident.name) {
+                        (sym::start, sym::end) => (field1.expr, field2.expr),
+                        (sym::end, sym::start) => (field2.expr, field1.expr),
+                        _ => return None,
+                    };
+                    Some(Range {
+                        start: Some(start),
+                        end: Some(end),
+                        limits: ast::RangeLimits::HalfOpen,
+                    })
+                },
+                (QPath::LangItem(hir::LangItem::RangeToInclusive, ..), [field]) if field.ident.name == sym::end => {
+                    Some(Range {
+                        start: None,
+                        end: Some(field.expr),
+                        limits: ast::RangeLimits::Closed,
+                    })
+                },
+                (QPath::LangItem(hir::LangItem::RangeTo, ..), [field]) if field.ident.name == sym::end => Some(Range {
                     start: None,
-                    end: Some(get_field("end", fields)?),
+                    end: Some(field.expr),
                     limits: ast::RangeLimits::HalfOpen,
                 }),
                 _ => None,

From 198bbf87a0ff94f7f297a1de8ee18fa3d3f34c1a Mon Sep 17 00:00:00 2001
From: xFrednet <xFrednet@gmail.com>
Date: Mon, 17 Jun 2024 15:22:06 +0200
Subject: [PATCH 56/56] Pause assignments to @xFrednet for summer break
 :beach_umbrella:

I'm only removing myself from the assignment roulette as I want to allow `r? xFrednet` for `gh-pages` and other updates. So feel free to still `r?` me.
---
 triagebot.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/triagebot.toml b/triagebot.toml
index 4d66b728b76d..ecada0514f7a 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -32,7 +32,6 @@ users_on_vacation = [
 "*" = [
     "@Manishearth",
     "@llogiq",
-    "@xFrednet",
     "@Alexendoo",
     "@dswij",
     "@Jarcho",