Auto merge of #97111 - JohnTitor:rollup-x3vjf6u, r=JohnTitor

Rollup of 7 pull requests

Successful merges:

 - #96329 (Add a couple tests for #90887 fixes)
 - #97009 (Allow `unused_macro_rules` in path tests)
 - #97075 (Add regression test for #81804)
 - #97079 (Change `Successors` to `impl Iterator<Item = BasicBlock>`)
 - #97080 (remove the `RelateResultCompare` trait)
 - #97093 (Migrate `maybe_recover_from_bad_type_plus` diagnostic)
 - #97102 (Update function pointer call error message)

Failed merges:

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

compiler/rustc_borrowck/src/dataflow.rs

@@ -199,7 +199,7 @@ impl<'tcx> OutOfScopePrecomputer<'_, 'tcx> {
                 // Add successor BBs to the work list, if necessary.
                 let bb_data = &self.body[bb];
                 debug_assert!(hi == bb_data.statements.len());
-                for &succ_bb in bb_data.terminator().successors() {
+                for succ_bb in bb_data.terminator().successors() {
                     if !self.visited.insert(succ_bb) {
                         if succ_bb == location.block && first_lo > 0 {
                             // `succ_bb` has been seen before. If it wasn't

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -467,7 +467,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     block
                         .terminator()
                         .successors()
-                        .map(|bb| Location { statement_index: 0, block: *bb })
+                        .map(|bb| Location { statement_index: 0, block: bb })
                         .filter(|s| visited_locations.insert(*s))
                         .map(|s| {
                             if self.is_back_edge(location, s) {
@@ -526,7 +526,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 }
             } else {
                 for bb in block.terminator().successors() {
-                    let successor = Location { statement_index: 0, block: *bb };
+                    let successor = Location { statement_index: 0, block: bb };
 
                     if !visited_locations.contains(&successor)
                         && self.find_loop_head_dfs(successor, loop_head, visited_locations)

compiler/rustc_borrowck/src/diagnostics/find_use.rs

@@ -67,8 +67,8 @@ impl<'cx, 'tcx> UseFinder<'cx, 'tcx> {
                             block_data
                                 .terminator()
                                 .successors()
-                                .filter(|&bb| Some(&Some(*bb)) != block_data.terminator().unwind())
-                                .map(|&bb| Location { statement_index: 0, block: bb }),
+                                .filter(|&bb| Some(&Some(bb)) != block_data.terminator().unwind())
+                                .map(|bb| Location { statement_index: 0, block: bb }),
                         );
                     }
                 }

compiler/rustc_borrowck/src/nll.rs

@@ -108,7 +108,7 @@ fn populate_polonius_move_facts(
                     // We are at the terminator of an init that has a panic path,
                     // and where the init should not happen on panic
 
-                    for &successor in block_data.terminator().successors() {
+                    for successor in block_data.terminator().successors() {
                         if body[successor].is_cleanup {
                             continue;
                         }

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -328,7 +328,7 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec<mir::BasicBlock, CleanupKi
                 bb, data, result[bb], funclet
             );
 
-            for &succ in data.terminator().successors() {
+            for succ in data.terminator().successors() {
                 let kind = result[succ];
                 debug!("cleanup_kinds: propagating {:?} to {:?}/{:?}", funclet, succ, kind);
                 match kind {

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -89,7 +89,10 @@ impl<'tcx> NonConstOp<'tcx> for FnCallIndirect {
         ccx: &ConstCx<'_, 'tcx>,
         span: Span,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
-        ccx.tcx.sess.struct_span_err(span, "function pointers are not allowed in const fn")
+        ccx.tcx.sess.struct_span_err(
+            span,
+            &format!("function pointer calls are not allowed in {}s", ccx.const_kind()),
+        )
     }
 }
 

compiler/rustc_error_messages/locales/en-US/parser.ftl

@@ -5,3 +5,12 @@ parser-struct-literal-body-without-path =
 parser-maybe-report-ambiguous-plus =
     ambiguous `+` in a type
     .suggestion = use parentheses to disambiguate
+
+parser-maybe-recover-from-bad-type-plus =
+    expected a path on the left-hand side of `+`, not `{$ty}`
+
+parser-add-paren = try adding parentheses
+
+parser-forgot-paren = perhaps you forgot parentheses?
+
+parser-expect-path = expected a path

compiler/rustc_infer/src/infer/combine.rs

@@ -776,21 +776,6 @@ pub trait ConstEquateRelation<'tcx>: TypeRelation<'tcx> {
     fn const_equate_obligation(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>);
 }
 
-pub trait RelateResultCompare<'tcx, T> {
-    fn compare<F>(&self, t: T, f: F) -> RelateResult<'tcx, T>
-    where
-        F: FnOnce() -> TypeError<'tcx>;
-}
-
-impl<'tcx, T: Clone + PartialEq> RelateResultCompare<'tcx, T> for RelateResult<'tcx, T> {
-    fn compare<F>(&self, t: T, f: F) -> RelateResult<'tcx, T>
-    where
-        F: FnOnce() -> TypeError<'tcx>,
-    {
-        self.clone().and_then(|s| if s == t { self.clone() } else { Err(f()) })
-    }
-}
-
 pub fn const_unification_error<'tcx>(
     a_is_expected: bool,
     (a, b): (ty::Const<'tcx>, ty::Const<'tcx>),

compiler/rustc_infer/src/infer/nll_relate/mod.rs

@@ -859,7 +859,7 @@ where
 
     delegate: &'me mut D,
 
-    /// After we generalize this type, we are going to relative it to
+    /// After we generalize this type, we are going to relate it to
     /// some other type. What will be the variance at this point?
     ambient_variance: ty::Variance,
 

compiler/rustc_middle/src/mir/generic_graph.rs

@@ -24,7 +24,7 @@ pub fn mir_fn_to_generic_graph<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Grap
         let terminator = body[source].terminator();
         let labels = terminator.kind.fmt_successor_labels();
 
-        for (&target, label) in terminator.successors().zip(labels) {
+        for (target, label) in terminator.successors().zip(labels) {
             let src = node(def_id, source);
             let trg = node(def_id, target);
             edges.push(Edge::new(src, trg, label.to_string()));

compiler/rustc_middle/src/mir/mod.rs

@@ -1355,10 +1355,7 @@ pub enum InlineAsmOperand<'tcx> {
 /// Type for MIR `Assert` terminator error messages.
 pub type AssertMessage<'tcx> = AssertKind<Operand<'tcx>>;
 
-// FIXME: Change `Successors` to `impl Iterator<Item = BasicBlock>`.
-#[allow(rustc::pass_by_value)]
-pub type Successors<'a> =
-    iter::Chain<option::IntoIter<&'a BasicBlock>, slice::Iter<'a, BasicBlock>>;
+pub type Successors<'a> = impl Iterator<Item = BasicBlock> + 'a;
 pub type SuccessorsMut<'a> =
     iter::Chain<option::IntoIter<&'a mut BasicBlock>, slice::IterMut<'a, BasicBlock>>;
 
@@ -3434,13 +3431,13 @@ impl<'tcx> graph::WithStartNode for Body<'tcx> {
 impl<'tcx> graph::WithSuccessors for Body<'tcx> {
     #[inline]
     fn successors(&self, node: Self::Node) -> <Self as GraphSuccessors<'_>>::Iter {
-        self.basic_blocks[node].terminator().successors().cloned()
+        self.basic_blocks[node].terminator().successors()
     }
 }
 
 impl<'a, 'b> graph::GraphSuccessors<'b> for Body<'a> {
     type Item = BasicBlock;
-    type Iter = iter::Cloned<Successors<'b>>;
+    type Iter = Successors<'b>;
 }
 
 impl<'tcx, 'graph> graph::GraphPredecessors<'graph> for Body<'tcx> {

compiler/rustc_middle/src/mir/patch.rs

@@ -166,9 +166,7 @@ impl<'tcx> MirPatch<'tcx> {
             // get terminator's targets and apply the statement to all of them.
             if loc.statement_index > body[loc.block].statements.len() {
                 let term = body[loc.block].terminator();
-                let successors = term.successors().clone();
-
-                for i in successors {
+                for i in term.successors() {
                     stmts_and_targets
                         .push((Statement { source_info, kind: stmt.clone() }, i.clone()));
                 }

compiler/rustc_middle/src/mir/predecessors.rs

@@ -43,7 +43,7 @@ impl PredecessorCache {
             let mut preds = IndexVec::from_elem(SmallVec::new(), basic_blocks);
             for (bb, data) in basic_blocks.iter_enumerated() {
                 if let Some(term) = &data.terminator {
-                    for &succ in term.successors() {
+                    for succ in term.successors() {
                         preds[succ].push(bb);
                     }
                 }

compiler/rustc_middle/src/mir/terminator.rs

@@ -416,32 +416,36 @@ impl<'tcx> TerminatorKind<'tcx> {
             | Return
             | Unreachable
             | Call { destination: None, cleanup: None, .. }
-            | InlineAsm { destination: None, cleanup: None, .. } => None.into_iter().chain(&[]),
-            Goto { target: ref t }
-            | Call { destination: None, cleanup: Some(ref t), .. }
-            | Call { destination: Some((_, ref t)), cleanup: None, .. }
-            | Yield { resume: ref t, drop: None, .. }
-            | DropAndReplace { target: ref t, unwind: None, .. }
-            | Drop { target: ref t, unwind: None, .. }
-            | Assert { target: ref t, cleanup: None, .. }
-            | FalseUnwind { real_target: ref t, unwind: None }
-            | InlineAsm { destination: Some(ref t), cleanup: None, .. }
-            | InlineAsm { destination: None, cleanup: Some(ref t), .. } => {
-                Some(t).into_iter().chain(&[])
+            | InlineAsm { destination: None, cleanup: None, .. } => {
+                None.into_iter().chain((&[]).into_iter().copied())
             }
-            Call { destination: Some((_, ref t)), cleanup: Some(ref u), .. }
-            | Yield { resume: ref t, drop: Some(ref u), .. }
-            | DropAndReplace { target: ref t, unwind: Some(ref u), .. }
-            | Drop { target: ref t, unwind: Some(ref u), .. }
-            | Assert { target: ref t, cleanup: Some(ref u), .. }
-            | FalseUnwind { real_target: ref t, unwind: Some(ref u) }
-            | InlineAsm { destination: Some(ref t), cleanup: Some(ref u), .. } => {
-                Some(t).into_iter().chain(slice::from_ref(u))
+            Goto { target: t }
+            | Call { destination: None, cleanup: Some(t), .. }
+            | Call { destination: Some((_, t)), cleanup: None, .. }
+            | Yield { resume: t, drop: None, .. }
+            | DropAndReplace { target: t, unwind: None, .. }
+            | Drop { target: t, unwind: None, .. }
+            | Assert { target: t, cleanup: None, .. }
+            | FalseUnwind { real_target: t, unwind: None }
+            | InlineAsm { destination: Some(t), cleanup: None, .. }
+            | InlineAsm { destination: None, cleanup: Some(t), .. } => {
+                Some(t).into_iter().chain((&[]).into_iter().copied())
             }
-            SwitchInt { ref targets, .. } => None.into_iter().chain(&targets.targets),
-            FalseEdge { ref real_target, ref imaginary_target } => {
-                Some(real_target).into_iter().chain(slice::from_ref(imaginary_target))
+            Call { destination: Some((_, t)), cleanup: Some(ref u), .. }
+            | Yield { resume: t, drop: Some(ref u), .. }
+            | DropAndReplace { target: t, unwind: Some(ref u), .. }
+            | Drop { target: t, unwind: Some(ref u), .. }
+            | Assert { target: t, cleanup: Some(ref u), .. }
+            | FalseUnwind { real_target: t, unwind: Some(ref u) }
+            | InlineAsm { destination: Some(t), cleanup: Some(ref u), .. } => {
+                Some(t).into_iter().chain(slice::from_ref(u).into_iter().copied())
             }
+            SwitchInt { ref targets, .. } => {
+                None.into_iter().chain(targets.targets.iter().copied())
+            }
+            FalseEdge { real_target, ref imaginary_target } => Some(real_target)
+                .into_iter()
+                .chain(slice::from_ref(imaginary_target).into_iter().copied()),
         }
     }
 

compiler/rustc_middle/src/mir/traversal.rs

@@ -180,7 +180,7 @@ impl<'a, 'tcx> Postorder<'a, 'tcx> {
         // two iterations yield `C` and finally `A` for a final traversal of [E, D, B, C, A]
         loop {
             let bb = if let Some(&mut (_, ref mut iter)) = self.visit_stack.last_mut() {
-                if let Some(&bb) = iter.next() {
+                if let Some(bb) = iter.next() {
                     bb
                 } else {
                     break;

compiler/rustc_mir_dataflow/src/framework/graphviz.rs

@@ -125,7 +125,7 @@ where
     }
 
     fn target(&self, edge: &Self::Edge) -> Self::Node {
-        self.body[edge.source].terminator().successors().nth(edge.index).copied().unwrap()
+        self.body[edge.source].terminator().successors().nth(edge.index).unwrap()
     }
 }
 

compiler/rustc_mir_transform/src/coverage/debug.rs

@@ -701,7 +701,7 @@ pub(super) fn dump_coverage_graphviz<'tcx>(
         edge_labels.retain(|label| label != "unreachable");
         let edge_counters = from_terminator
             .successors()
-            .map(|&successor_bb| graphviz_data.get_edge_counter(from_bcb, successor_bb));
+            .map(|successor_bb| graphviz_data.get_edge_counter(from_bcb, successor_bb));
         iter::zip(&edge_labels, edge_counters)
             .map(|(label, some_counter)| {
                 if let Some(counter) = some_counter {

compiler/rustc_mir_transform/src/coverage/graph.rs

@@ -484,17 +484,17 @@ fn bcb_filtered_successors<'a, 'tcx>(
     body: &'tcx &'a mir::Body<'tcx>,
     term_kind: &'tcx TerminatorKind<'tcx>,
 ) -> Box<dyn Iterator<Item = BasicBlock> + 'a> {
-    let mut successors = term_kind.successors();
     Box::new(
         match &term_kind {
             // SwitchInt successors are never unwind, and all of them should be traversed.
-            TerminatorKind::SwitchInt { .. } => successors,
+            TerminatorKind::SwitchInt { ref targets, .. } => {
+                None.into_iter().chain(targets.all_targets().into_iter().copied())
+            }
             // For all other kinds, return only the first successor, if any, and ignore unwinds.
             // NOTE: `chain(&[])` is required to coerce the `option::iter` (from
             // `next().into_iter()`) into the `mir::Successors` aliased type.
-            _ => successors.next().into_iter().chain(&[]),
+            _ => term_kind.successors().next().into_iter().chain((&[]).into_iter().copied()),
         }
-        .copied()
         .filter(move |&successor| body[successor].terminator().kind != TerminatorKind::Unreachable),
     )
 }

compiler/rustc_mir_transform/src/inline.rs

@@ -449,7 +449,7 @@ impl<'tcx> Inliner<'tcx> {
             }
 
             if !is_drop {
-                for &succ in term.successors() {
+                for succ in term.successors() {
                     work_list.push(succ);
                 }
             }

compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs

@@ -65,7 +65,7 @@ impl RemoveNoopLandingPads {
             | TerminatorKind::SwitchInt { .. }
             | TerminatorKind::FalseEdge { .. }
             | TerminatorKind::FalseUnwind { .. } => {
-                terminator.successors().all(|&succ| nop_landing_pads.contains(succ))
+                terminator.successors().all(|succ| nop_landing_pads.contains(succ))
             }
             TerminatorKind::GeneratorDrop
             | TerminatorKind::Yield { .. }

compiler/rustc_mir_transform/src/simplify.rs

@@ -81,7 +81,7 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
 
         for (_, data) in traversal::preorder(body) {
             if let Some(ref term) = data.terminator {
-                for &tgt in term.successors() {
+                for tgt in term.successors() {
                     pred_count[tgt] += 1;
                 }
             }
@@ -235,8 +235,8 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
         };
 
         let first_succ = {
-            if let Some(&first_succ) = terminator.successors().next() {
-                if terminator.successors().all(|s| *s == first_succ) {
+            if let Some(first_succ) = terminator.successors().next() {
+                if terminator.successors().all(|s| s == first_succ) {
                     let count = terminator.successors().count();
                     self.pred_count[first_succ] -= (count - 1) as u32;
                     first_succ

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -21,7 +21,7 @@ use rustc_errors::{pluralize, struct_span_err, Diagnostic, EmissionGuarantee, Er
 use rustc_errors::{
     Applicability, DiagnosticBuilder, DiagnosticMessage, Handler, MultiSpan, PResult,
 };
-use rustc_macros::SessionDiagnostic;
+use rustc_macros::{SessionDiagnostic, SessionSubdiagnostic};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, Ident};
 use rustc_span::{Span, SpanSnippetError, DUMMY_SP};
@@ -252,6 +252,40 @@ struct AmbiguousPlus {
     pub span: Span,
 }
 
+#[derive(SessionDiagnostic)]
+#[error(code = "E0178", slug = "parser-maybe-recover-from-bad-type-plus")]
+struct BadTypePlus<'a> {
+    pub ty: String,
+    #[primary_span]
+    pub span: Span,
+    #[subdiagnostic]
+    pub sub: BadTypePlusSub<'a>,
+}
+
+#[derive(SessionSubdiagnostic, Clone, Copy)]
+pub enum BadTypePlusSub<'a> {
+    #[suggestion(
+        slug = "parser-add-paren",
+        code = "{sum_with_parens}",
+        applicability = "machine-applicable"
+    )]
+    AddParen {
+        sum_with_parens: &'a str,
+        #[primary_span]
+        span: Span,
+    },
+    #[label(slug = "parser-forgot-paren")]
+    ForgotParen {
+        #[primary_span]
+        span: Span,
+    },
+    #[label(slug = "parser-expect-path")]
+    ExpectPath {
+        #[primary_span]
+        span: Span,
+    },
+}
+
 // SnapshotParser is used to create a snapshot of the parser
 // without causing duplicate errors being emitted when the `Parser`
 // is dropped.
@@ -1255,17 +1289,11 @@ impl<'a> Parser<'a> {
         let bounds = self.parse_generic_bounds(None)?;
         let sum_span = ty.span.to(self.prev_token.span);
 
-        let mut err = struct_span_err!(
-            self.sess.span_diagnostic,
-            sum_span,
-            E0178,
-            "expected a path on the left-hand side of `+`, not `{}`",
-            pprust::ty_to_string(ty)
-        );
+        let sum_with_parens: String;
 
-        match ty.kind {
+        let sub = match ty.kind {
             TyKind::Rptr(ref lifetime, ref mut_ty) => {
-                let sum_with_parens = pprust::to_string(|s| {
+                sum_with_parens = pprust::to_string(|s| {
                     s.s.word("&");
                     s.print_opt_lifetime(lifetime);
                     s.print_mutability(mut_ty.mutbl, false);
@@ -1274,21 +1302,15 @@ impl<'a> Parser<'a> {
                     s.print_type_bounds(" +", &bounds);
                     s.pclose()
                 });
-                err.span_suggestion(
-                    sum_span,
-                    "try adding parentheses",
-                    sum_with_parens,
-                    Applicability::MachineApplicable,
-                );
+
+                BadTypePlusSub::AddParen { sum_with_parens: &sum_with_parens, span: sum_span }
             }
-            TyKind::Ptr(..) | TyKind::BareFn(..) => {
-                err.span_label(sum_span, "perhaps you forgot parentheses?");
-            }
-            _ => {
-                err.span_label(sum_span, "expected a path");
-            }
-        }
-        err.emit();
+            TyKind::Ptr(..) | TyKind::BareFn(..) => BadTypePlusSub::ForgotParen { span: sum_span },
+            _ => BadTypePlusSub::ExpectPath { span: sum_span },
+        };
+
+        self.sess.emit_err(BadTypePlus { ty: pprust::ty_to_string(ty), span: sum_span, sub });
+
         Ok(())
     }
 

library/std/src/path/tests.rs

@@ -7,6 +7,7 @@ use crate::rc::Rc;
 use crate::sync::Arc;
 use core::hint::black_box;
 
+#[allow(unknown_lints, unused_macro_rules)]
 macro_rules! t (
     ($path:expr, iter: $iter:expr) => (
         {

src/test/ui/consts/const-fn-ptr.rs

@@ -0,0 +1,16 @@
+const fn make_fn_ptr() -> fn() {
+    || {}
+}
+
+static STAT: () = make_fn_ptr()();
+//~^ ERROR function pointer
+
+const CONST: () = make_fn_ptr()();
+//~^ ERROR function pointer
+
+const fn call_ptr() {
+    make_fn_ptr()();
+    //~^ ERROR function pointer
+}
+
+fn main() {}

src/test/ui/consts/const-fn-ptr.stderr

@@ -0,0 +1,20 @@
+error: function pointer calls are not allowed in statics
+  --> $DIR/const-fn-ptr.rs:5:19
+   |
+LL | static STAT: () = make_fn_ptr()();
+   |                   ^^^^^^^^^^^^^^^
+
+error: function pointer calls are not allowed in constants
+  --> $DIR/const-fn-ptr.rs:8:19
+   |
+LL | const CONST: () = make_fn_ptr()();
+   |                   ^^^^^^^^^^^^^^^
+
+error: function pointer calls are not allowed in constant functions
+  --> $DIR/const-fn-ptr.rs:12:5
+   |
+LL |     make_fn_ptr()();
+   |     ^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+

src/test/ui/consts/issue-56164.stderr

@@ -7,7 +7,7 @@ LL | const fn foo() { (||{})() }
    = note: closures need an RFC before allowed to be called in constant functions
    = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
 
-error: function pointers are not allowed in const fn
+error: function pointer calls are not allowed in constant functions
   --> $DIR/issue-56164.rs:7:5
    |
 LL |     input()

src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-56556.rs

@@ -11,3 +11,20 @@ where
 fn main() {
     foo::<Vec<u32>>(vec![]);
 }
+
+mod another {
+    use std::ops::Deref;
+
+    fn test<T, TDeref>()
+    where
+        T: Deref<Target = TDeref>,
+        TDeref: ?Sized,
+        for<'a> &'a TDeref: IntoIterator,
+        for<'a> <&'a TDeref as IntoIterator>::IntoIter: Clone,
+    {
+    }
+
+    fn main() {
+        test::<Vec<u8>, _>();
+    }
+}

src/test/ui/higher-rank-trait-bounds/normalize-under-binder/issue-90875.rs

@@ -0,0 +1,31 @@
+// check-pass
+
+trait Variable<'a> {
+    type Type;
+}
+
+impl Variable<'_> for () {
+    type Type = ();
+}
+
+fn check<F, T>(_: F)
+where
+    F: Fn(T), // <- if removed, all fn_* then require type annotations
+    F: for<'a> Fn(<T as Variable<'a>>::Type),
+    T: for<'a> Variable<'a>,
+{
+}
+
+fn test(arg: impl Fn(())) {
+    fn fn_1(_: ()) {}
+    let fn_2 = |_: ()| ();
+    let fn_3 = |a| fn_1(a);
+    let fn_4 = arg;
+
+    check(fn_1); // Error
+    check(fn_2); // Ok
+    check(fn_3); // Ok
+    check(fn_4); // Error
+}
+
+fn main() {}

src/test/ui/parser/issue-81804.rs

@@ -0,0 +1,9 @@
+// error-pattern: this file contains an unclosed delimiter
+// error-pattern: this file contains an unclosed delimiter
+// error-pattern: expected pattern, found `=`
+// error-pattern: expected one of `)`, `,`, `->`, `where`, or `{`, found `]`
+// error-pattern: expected item, found `]`
+
+fn main() {}
+
+fn p([=(}

src/test/ui/parser/issue-81804.stderr

@@ -0,0 +1,41 @@
+error: this file contains an unclosed delimiter
+  --> $DIR/issue-81804.rs:9:11
+   |
+LL | fn p([=(}
+   |     --    ^
+   |     ||
+   |     |unclosed delimiter
+   |     unclosed delimiter
+
+error: this file contains an unclosed delimiter
+  --> $DIR/issue-81804.rs:9:11
+   |
+LL | fn p([=(}
+   |     --    ^
+   |     ||
+   |     |unclosed delimiter
+   |     unclosed delimiter
+
+error: expected pattern, found `=`
+  --> $DIR/issue-81804.rs:9:7
+   |
+LL | fn p([=(}
+   |       ^ expected pattern
+
+error: expected one of `)`, `,`, `->`, `where`, or `{`, found `]`
+  --> $DIR/issue-81804.rs:9:8
+   |
+LL | fn p([=(}
+   |        ^ -^
+   |        | |
+   |        | help: `)` may belong here
+   |        unclosed delimiter
+
+error: expected item, found `]`
+  --> $DIR/issue-81804.rs:9:11
+   |
+LL | fn p([=(}
+   |           ^ expected item
+
+error: aborting due to 5 previous errors
+

src/tools/clippy/clippy_lints/src/redundant_clone.rs

@@ -114,7 +114,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClone {
             }
 
             // Give up on loops
-            if terminator.successors().any(|s| *s == bb) {
+            if terminator.successors().any(|s| s == bb) {
                 continue;
             }
 
@@ -440,7 +440,7 @@ fn visit_clone_usage(cloned: mir::Local, clone: mir::Local, mir: &mir::Body<'_>,
             // Short-circuit
             if (usage.cloned_used && usage.clone_consumed_or_mutated) ||
                 // Give up on loops
-                tdata.terminator().successors().any(|s| *s == bb)
+                tdata.terminator().successors().any(|s| s == bb)
             {
                 return CloneUsage {
                     cloned_used: true,