From 9e72e35ceb2af024e8ca6a74442269f7ec739173 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Wed, 2 Nov 2022 21:22:24 -0700
Subject: [PATCH 01/15] Suggest `.clone()` or `ref binding` on E0382

---
 compiler/rustc_ast/src/ast.rs                 |   2 +-
 compiler/rustc_ast/src/mut_visit.rs           |   3 +-
 compiler/rustc_ast/src/visit.rs               |   2 +-
 compiler/rustc_ast_lowering/src/expr.rs       |   4 +-
 .../rustc_ast_pretty/src/pprust/state/expr.rs |   2 +-
 .../src/diagnostics/conflict_errors.rs        | 192 ++++++++++++++++--
 .../src/assert/context.rs                     |   2 +-
 compiler/rustc_parse/src/parser/expr.rs       |   5 +-
 compiler/rustc_resolve/src/late.rs            |   4 +-
 .../binding/issue-53114-borrow-checks.stderr  |  16 ++
 src/test/ui/binop/binop-move-semantics.stderr |   4 +
 ...atterns-slice-patterns-box-patterns.stderr |  23 +++
 .../borrowck-consume-unsize-vec.stderr        |  12 ++
 .../borrowck-consume-upcast-box.stderr        |   8 +
 .../borrowck/borrowck-drop-from-guard.stderr  |   5 +
 .../borrowck-loan-in-overloaded-op.stderr     |   5 +
 .../borrowck-move-out-from-array-match.stderr |  40 ++++
 ...ove-out-from-array-no-overlap-match.stderr |  36 ++++
 ...rowck-move-out-from-array-use-match.stderr |  56 +++++
 ...out-from-array-use-no-overlap-match.stderr |  36 ++++
 .../borrowck-move-out-from-array-use.stderr   |  56 +++++
 .../borrowck-move-out-from-array.stderr       |  40 ++++
 .../borrowck-multiple-captures.stderr         |  15 ++
 ...orrowck-overloaded-index-move-index.stderr |   5 +
 src/test/ui/borrowck/borrowck-reinit.stderr   |   5 +
 .../borrowck/issue-31287-drop-in-guard.stderr |   5 +
 src/test/ui/borrowck/issue-41962.stderr       |   2 +-
 src/test/ui/borrowck/issue-83760.stderr       |   4 +
 .../move-in-pattern-mut-in-loop.stderr        |   2 +-
 .../ui/borrowck/move-in-pattern-mut.stderr    |   4 +-
 src/test/ui/borrowck/move-in-pattern.stderr   |   4 +-
 .../ui/borrowck/mut-borrow-in-loop-2.stderr   |   8 +
 src/test/ui/borrowck/or-patterns.stderr       |  16 ++
 .../ui/closure_context/issue-42065.stderr     |   4 +
 src/test/ui/codemap_tests/tab_3.stderr        |   4 +
 src/test/ui/drop/repeat-drop-2.stderr         |   5 +
 src/test/ui/issues/issue-29723.stderr         |   5 +
 src/test/ui/issues/issue-42796.stderr         |   4 +
 src/test/ui/issues/issue-61108.stderr         |   4 +
 src/test/ui/issues/issue-64559.stderr         |   4 +
 .../ui/liveness/liveness-move-call-arg.stderr |  16 +-
 .../ui/liveness/liveness-move-in-loop.stderr  |  14 ++
 .../ui/liveness/liveness-move-in-while.stderr |  12 +-
 .../liveness/liveness-use-after-move.stderr   |   4 +
 .../liveness/liveness-use-after-send.stderr   |   9 +
 .../borrow-closures-instead-of-move.stderr    |  22 ++
 .../ui/moves/issue-46099-move-in-macro.stderr |   5 +
 .../ui/moves/issue-72649-uninit-in-loop.rs    |   6 +-
 .../moves/issue-72649-uninit-in-loop.stderr   |  10 +-
 .../ui/moves/move-fn-self-receiver.stderr     |  14 ++
 .../ui/moves/move-guard-same-consts.stderr    |  12 ++
 src/test/ui/moves/move-in-guard-1.stderr      |  12 ++
 src/test/ui/moves/move-in-guard-2.stderr      |  12 ++
 ...moves-based-on-type-access-to-field.stderr |   4 +
 ...sed-on-type-cyclic-types-issue-4821.stderr |   2 +-
 ...-on-type-distribute-copy-over-paren.stderr |  10 +
 .../ui/moves/moves-based-on-type-exprs.stderr |  60 ++++++
 .../moves-based-on-type-match-bindings.stderr |   4 +
 .../ui/moves/moves-based-on-type-tuple.stderr |   5 +
 ...se_of_moved_value_clone_suggestions.stderr |   5 +
 src/test/ui/nll/closure-access-spans.stderr   |  10 +
 .../issue-21232-partial-init-and-use.stderr   |  24 +++
 src/test/ui/nll/issue-51512.stderr            |   5 +
 src/test/ui/nll/issue-53807.stderr            |   2 +-
 src/test/ui/nll/match-cfg-fake-edges.stderr   |   5 +
 src/test/ui/nll/ref-suggestion.stderr         |  12 +-
 ...can-live-while-the-other-survives-1.stderr |   4 +-
 .../borrowck-move-and-move.stderr             |  31 +++
 .../borrowck-pat-at-and-box.stderr            |   4 +
 ...orrowck-pat-by-move-and-ref-inverse.stderr |  23 +++
 .../borrowck-pat-by-move-and-ref.stderr       |  25 ++-
 .../copy-and-move-mixed.stderr                |   4 +
 ...inding-modes-both-sides-independent.stderr |   5 +
 .../borrowck-move-ref-pattern.stderr          |   4 +
 .../dbg-macro-move-semantics.stderr           |   6 +
 .../suggestions/borrow-for-loop-head.stderr   |   5 +
 .../try-block-maybe-bad-lifetime.stderr       |   4 +
 ...ed-closures-infer-fnonce-call-twice.stderr |   4 +
 ...osures-infer-fnonce-move-call-twice.stderr |   4 +
 .../ui/union/union-move.mirunsafeck.stderr    |  16 ++
 .../ui/union/union-move.thirunsafeck.stderr   |  16 ++
 src/test/ui/unop-move-semantics.stderr        |   4 +
 .../unsized-locals/borrow-after-move.stderr   |  13 ++
 src/test/ui/unsized-locals/double-move.stderr |   8 +
 .../use/use-after-move-based-on-type.stderr   |   4 +
 ...after-move-implicity-coerced-object.stderr |   8 +
 86 files changed, 1092 insertions(+), 49 deletions(-)

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 54bd25d647130..28072f153a479 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -1376,7 +1376,7 @@ pub enum ExprKind {
     /// Conditionless loop (can be exited with `break`, `continue`, or `return`).
     ///
     /// `'label: loop { block }`
-    Loop(P<Block>, Option<Label>),
+    Loop(P<Block>, Option<Label>, Span),
     /// A `match` block.
     Match(P<Expr>, Vec<Arm>),
     /// A closure (e.g., `move |a, b, c| a + b + c`).
diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index 4e1dcb2842f67..a5b24c403dd37 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -1355,9 +1355,10 @@ pub fn noop_visit_expr<T: MutVisitor>(
             vis.visit_block(body);
             visit_opt(label, |label| vis.visit_label(label));
         }
-        ExprKind::Loop(body, label) => {
+        ExprKind::Loop(body, label, span) => {
             vis.visit_block(body);
             visit_opt(label, |label| vis.visit_label(label));
+            vis.visit_span(span);
         }
         ExprKind::Match(expr, arms) => {
             vis.visit_expr(expr);
diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs
index 5c69e53521275..c528118be0808 100644
--- a/compiler/rustc_ast/src/visit.rs
+++ b/compiler/rustc_ast/src/visit.rs
@@ -824,7 +824,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
         }
-        ExprKind::Loop(block, opt_label) => {
+        ExprKind::Loop(block, opt_label, _) => {
             walk_list!(visitor, visit_label, opt_label);
             visitor.visit_block(block);
         }
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index a00100ee0a845..6215d9af3702b 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -131,12 +131,12 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     let span = this.mark_span_with_reason(DesugaringKind::WhileLoop, e.span, None);
                     this.lower_expr_while_in_loop_scope(span, cond, body, *opt_label)
                 }),
-                ExprKind::Loop(body, opt_label) => self.with_loop_scope(e.id, |this| {
+                ExprKind::Loop(body, opt_label, span) => self.with_loop_scope(e.id, |this| {
                     hir::ExprKind::Loop(
                         this.lower_block(body, false),
                         this.lower_label(*opt_label),
                         hir::LoopSource::Loop,
-                        DUMMY_SP,
+                        this.lower_span(span),
                     )
                 }),
                 ExprKind::TryBlock(body) => self.lower_expr_try_block(body),
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
index 1da40d2302e12..4b37fa027f53b 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state/expr.rs
@@ -377,7 +377,7 @@ impl<'a> State<'a> {
                 self.space();
                 self.print_block_with_attrs(blk, attrs);
             }
-            ast::ExprKind::Loop(ref blk, opt_label) => {
+            ast::ExprKind::Loop(ref blk, opt_label, _) => {
                 if let Some(label) = opt_label {
                     self.print_ident(label.ident);
                     self.word_space(":");
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 5f99d86b4eaff..9b6836039a138 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -191,6 +191,146 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     is_loop_move = true;
                 }
 
+                struct ExpressionFinder<'hir> {
+                    expr_span: Span,
+                    expr: Option<&'hir hir::Expr<'hir>>,
+                    pat: Option<&'hir hir::Pat<'hir>>,
+                }
+                impl<'hir> Visitor<'hir> for ExpressionFinder<'hir> {
+                    fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
+                        if e.span == self.expr_span {
+                            self.expr = Some(e);
+                        }
+                        hir::intravisit::walk_expr(self, e);
+                    }
+                    fn visit_pat(&mut self, p: &'hir hir::Pat<'hir>) {
+                        if p.span == self.expr_span {
+                            self.pat = Some(p);
+                        }
+                        if let hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, i, _) = p.kind
+                            && i.span == self.expr_span
+                        {
+                            self.pat = Some(p);
+                        }
+                        hir::intravisit::walk_pat(self, p);
+                    }
+                }
+
+                let hir = self.infcx.tcx.hir();
+                if let Some(hir::Node::Item(hir::Item {
+                    kind: hir::ItemKind::Fn(_, _, body_id),
+                    ..
+                })) = hir.find(hir.local_def_id_to_hir_id(self.mir_def_id()))
+                    && let Some(hir::Node::Expr(expr)) = hir.find(body_id.hir_id)
+                {
+                    let place = &self.move_data.move_paths[mpi].place;
+                    let span = place.as_local()
+                        .map(|local| self.body.local_decls[local].source_info.span);
+                    let mut finder = ExpressionFinder {
+                        expr_span: move_span,
+                        expr: None,
+                        pat: None,
+                    };
+                    finder.visit_expr(expr);
+                    if let Some(span) = span && let Some(expr) = finder.expr {
+                        for (_, expr) in hir.parent_iter(expr.hir_id) {
+                            if let hir::Node::Expr(expr) = expr {
+                                if expr.span.contains(span) {
+                                    // If the let binding occurs within the same loop, then that
+                                    // loop isn't relevant, like in the following, the outermost `loop`
+                                    // doesn't play into `x` being moved.
+                                    // ```
+                                    // loop {
+                                    //     let x = String::new();
+                                    //     loop {
+                                    //         foo(x);
+                                    //     }
+                                    // }
+                                    // ```
+                                    break;
+                                }
+                                if let hir::ExprKind::Loop(.., loop_span) = expr.kind {
+                                    err.span_label(loop_span, "inside of this loop");
+                                }
+                            }
+                        }
+                        let typeck = self.infcx.tcx.typeck(self.mir_def_id());
+                        let hir_id = hir.get_parent_node(expr.hir_id);
+                        if let Some(parent) = hir.find(hir_id) {
+                            if let hir::Node::Expr(parent_expr) = parent
+                                && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
+                                && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
+                                && let Some(def_id) = def_id.as_local()
+                                && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
+                                && let Some(fn_sig) = node.fn_sig()
+                                && let Some(ident) = node.ident()
+                                && let Some(pos) = args.iter()
+                                    .position(|arg| arg.hir_id == expr.hir_id)
+                                && let Some(arg) = fn_sig.decl.inputs.get(pos + 1)
+                            {
+                                let mut span: MultiSpan = arg.span.into();
+                                span.push_span_label(
+                                    arg.span,
+                                    "this type parameter takes ownership of the value".to_string(),
+                                );
+                                span.push_span_label(
+                                    ident.span,
+                                    "in this method".to_string(),
+                                );
+                                err.span_note(
+                                    span,
+                                    format!(
+                                        "consider changing this parameter type in `{}` to borrow \
+                                         instead if ownering the value isn't necessary",
+                                        ident,
+                                    ),
+                                );
+                            }
+                            if let hir::Node::Expr(parent_expr) = parent
+                                && let hir::ExprKind::Call(call, args) = parent_expr.kind
+                                && let ty::FnDef(def_id, _) = typeck.node_type(call.hir_id).kind()
+                                && let Some(def_id) = def_id.as_local()
+                                && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
+                                && let Some(fn_sig) = node.fn_sig()
+                                && let Some(ident) = node.ident()
+                                && let Some(pos) = args.iter()
+                                    .position(|arg| arg.hir_id == expr.hir_id)
+                                && let Some(arg) = fn_sig.decl.inputs.get(pos)
+                            {
+                                let mut span: MultiSpan = arg.span.into();
+                                span.push_span_label(
+                                    arg.span,
+                                    "this type parameter takes ownership of the value".to_string(),
+                                );
+                                span.push_span_label(
+                                    ident.span,
+                                    "in this function".to_string(),
+                                );
+                                err.span_note(
+                                    span,
+                                    format!(
+                                        "consider changing this parameter type in `{}` to borrow \
+                                         instead if ownering the value isn't necessary",
+                                        ident,
+                                    ),
+                                );
+                            }
+                            let place = &self.move_data.move_paths[mpi].place;
+                            let ty = place.ty(self.body, self.infcx.tcx).ty;
+                            self.suggest_cloning(&mut err, ty, move_span);
+                        }
+                    }
+                    if let Some(pat) = finder.pat {
+                        in_pattern = true;
+                        err.span_suggestion_verbose(
+                            pat.span.shrink_to_lo(),
+                            "borrow this binding in the pattern to avoid moving the value",
+                            "ref ".to_string(),
+                            Applicability::MachineApplicable,
+                        );
+                    }
+                }
+
                 self.explain_captures(
                     &mut err,
                     span,
@@ -203,25 +343,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     is_loop_move,
                     maybe_reinitialized_locations.is_empty(),
                 );
-
-                if let (UseSpans::PatUse(span), []) =
-                    (move_spans, &maybe_reinitialized_locations[..])
-                {
-                    if maybe_reinitialized_locations.is_empty() {
-                        err.span_suggestion_verbose(
-                            span.shrink_to_lo(),
-                            &format!(
-                                "borrow this field in the pattern to avoid moving {}",
-                                self.describe_place(moved_place.as_ref())
-                                    .map(|n| format!("`{}`", n))
-                                    .unwrap_or_else(|| "the value".to_string())
-                            ),
-                            "ref ",
-                            Applicability::MachineApplicable,
-                        );
-                        in_pattern = true;
-                    }
-                }
             }
 
             use_spans.var_path_only_subdiag(&mut err, desired_action);
@@ -590,6 +711,39 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         true
     }
 
+    fn suggest_cloning(&self, err: &mut Diagnostic, ty: Ty<'tcx>, span: Span) {
+        let tcx = self.infcx.tcx;
+
+        // Try to find predicates on *generic params* that would allow copying `ty`
+        let infcx = tcx.infer_ctxt().build();
+        let mut fulfill_cx = <dyn rustc_infer::traits::TraitEngine<'_>>::new(infcx.tcx);
+
+        let clone_did = infcx.tcx.lang_items().clone_trait().unwrap();
+        let cause = ObligationCause::new(
+            span,
+            self.mir_hir_id(),
+            rustc_infer::traits::ObligationCauseCode::MiscObligation,
+        );
+        fulfill_cx.register_bound(
+            &infcx,
+            self.param_env,
+            // Erase any region vids from the type, which may not be resolved
+            infcx.tcx.erase_regions(ty),
+            clone_did,
+            cause,
+        );
+        // Select all, including ambiguous predicates
+        let errors = fulfill_cx.select_all_or_error(&infcx);
+        if errors.is_empty() {
+            err.span_suggestion_verbose(
+                span.shrink_to_hi(),
+                "consider cloning the value if the performance cost is acceptable",
+                ".clone()".to_string(),
+                Applicability::MachineApplicable,
+            );
+        }
+    }
+
     fn suggest_adding_copy_bounds(&self, err: &mut Diagnostic, ty: Ty<'tcx>, span: Span) {
         let tcx = self.infcx.tcx;
         let generics = tcx.generics_of(self.mir_def_id());
diff --git a/compiler/rustc_builtin_macros/src/assert/context.rs b/compiler/rustc_builtin_macros/src/assert/context.rs
index 220b7a8ad0fcd..9f42a0c2d585c 100644
--- a/compiler/rustc_builtin_macros/src/assert/context.rs
+++ b/compiler/rustc_builtin_macros/src/assert/context.rs
@@ -307,7 +307,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
             | ExprKind::InlineAsm(_)
             | ExprKind::Let(_, _, _)
             | ExprKind::Lit(_)
-            | ExprKind::Loop(_, _)
+            | ExprKind::Loop(_, _, _)
             | ExprKind::MacCall(_)
             | ExprKind::Match(_, _)
             | ExprKind::Path(_, _)
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index dc914f5ea6454..9f2267efb8287 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1734,7 +1734,7 @@ impl<'a> Parser<'a> {
                         expr.kind,
                         ExprKind::While(_, _, None)
                             | ExprKind::ForLoop(_, _, _, None)
-                            | ExprKind::Loop(_, None)
+                            | ExprKind::Loop(_, None, _)
                             | ExprKind::Block(_, None)
                     )
                 {
@@ -2444,10 +2444,11 @@ impl<'a> Parser<'a> {
 
     /// Parses `loop { ... }` (`loop` token already eaten).
     fn parse_loop_expr(&mut self, opt_label: Option<Label>, lo: Span) -> PResult<'a, P<Expr>> {
+        let loop_span = self.prev_token.span;
         let (attrs, body) = self.parse_inner_attrs_and_block()?;
         Ok(self.mk_expr_with_attrs(
             lo.to(self.prev_token.span),
-            ExprKind::Loop(body, opt_label),
+            ExprKind::Loop(body, opt_label, loop_span),
             attrs,
         ))
     }
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 5072d2aad1669..93b0f5814dedf 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -3841,7 +3841,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 }
             }
 
-            ExprKind::Loop(ref block, label) => self.resolve_labeled_block(label, expr.id, &block),
+            ExprKind::Loop(ref block, label, _) => {
+                self.resolve_labeled_block(label, expr.id, &block)
+            }
 
             ExprKind::While(ref cond, ref block, label) => {
                 self.with_resolved_label(label, expr.id, |this| {
diff --git a/src/test/ui/binding/issue-53114-borrow-checks.stderr b/src/test/ui/binding/issue-53114-borrow-checks.stderr
index 489bf70d920a3..0ec2ae8839e79 100644
--- a/src/test/ui/binding/issue-53114-borrow-checks.stderr
+++ b/src/test/ui/binding/issue-53114-borrow-checks.stderr
@@ -17,6 +17,10 @@ LL |     match mm { (_, _y) => { } }
    |           ^^ value used here after partial move
    |
    = note: partial move occurs because `mm.0` has type `M`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     match mm { (ref _x, _) => { } }
+   |                 +++
 
 error[E0382]: use of partially moved value: `mm`
   --> $DIR/issue-53114-borrow-checks.rs:29:11
@@ -28,6 +32,10 @@ LL |     match mm { (_, _) => { } }
    |           ^^ value used here after partial move
    |
    = note: partial move occurs because `mm.1` has type `M`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     match mm { (_, ref _y) => { } }
+   |                    +++
 
 error[E0382]: use of moved value: `m`
   --> $DIR/issue-53114-borrow-checks.rs:36:16
@@ -48,6 +56,10 @@ LL |     if let (_, _y) = mm { }
    |                      ^^ value used here after partial move
    |
    = note: partial move occurs because `mm.0` has type `M`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     if let (ref _x, _) = mm { }
+   |             +++
 
 error[E0382]: use of partially moved value: `mm`
   --> $DIR/issue-53114-borrow-checks.rs:43:21
@@ -59,6 +71,10 @@ LL |     if let (_, _) = mm { }
    |                     ^^ value used here after partial move
    |
    = note: partial move occurs because `mm.1` has type `M`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     if let (_, ref _y) = mm { }
+   |                +++
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/binop/binop-move-semantics.stderr b/src/test/ui/binop/binop-move-semantics.stderr
index 695b01d5ee3ad..994eaf9d8c778 100644
--- a/src/test/ui/binop/binop-move-semantics.stderr
+++ b/src/test/ui/binop/binop-move-semantics.stderr
@@ -32,6 +32,10 @@ LL |     +
 LL |     x.clone();
    |     ^^^^^^^^^ value borrowed here after move
    |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     x.clone()
+   |      ++++++++
 help: consider further restricting this bound
    |
 LL | fn move_then_borrow<T: Add<Output=()> + Clone + Copy>(x: T) {
diff --git a/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr b/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
index 1fd1eb128511b..f58672f0666be 100644
--- a/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
+++ b/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
@@ -27,6 +27,11 @@ LL |         a @ [.., _] => (),
 ...
 LL |     &x;
    |     ^^ value borrowed here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ [.., _] => (),
+   |         +++
 
 error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:28:5
@@ -78,6 +83,15 @@ LL |         foo @ Some(Test::Foo | Test::Bar) => (),
 ...
 LL |     &x;
    |     ^^ value borrowed here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref foo @ Some(Test::Foo | Test::Bar) => (),
+   |         +++
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref foo @ Some(Test::Foo | Test::Bar) => (),
+   |         +++
 
 error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:86:5
@@ -129,6 +143,15 @@ LL |         a @ [.., Some(Test::Foo | Test::Bar)] => (),
 ...
 LL |     &x;
    |     ^^ value borrowed here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ [.., Some(Test::Foo | Test::Bar)] => (),
+   |         +++
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ [.., Some(Test::Foo | Test::Bar)] => (),
+   |         +++
 
 error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:144:5
diff --git a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
index 17b9310661583..00bb13caebdb5 100644
--- a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
@@ -7,6 +7,18 @@ LL |     consume(b);
    |             - value moved here
 LL |     consume(b);
    |             ^ value used here after move
+   |
+note: consider changing this parameter type in `consume` to borrow instead if ownering the value isn't necessary
+  --> $DIR/borrowck-consume-unsize-vec.rs:3:15
+   |
+LL | fn consume(_: Box<[i32]>) {
+   |    -------    ^^^^^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     consume(b.clone());
+   |              ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
index 4e20bbf175770..103f45155d7ba 100644
--- a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
@@ -7,6 +7,14 @@ LL |     consume(b);
    |             - value moved here
 LL |     consume(b);
    |             ^ value used here after move
+   |
+note: consider changing this parameter type in `consume` to borrow instead if ownering the value isn't necessary
+  --> $DIR/borrowck-consume-upcast-box.rs:5:15
+   |
+LL | fn consume(_: Box<dyn Foo>) {
+   |    -------    ^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/borrowck/borrowck-drop-from-guard.stderr b/src/test/ui/borrowck/borrowck-drop-from-guard.stderr
index cd0d2fee9422f..eaf4bb38bc590 100644
--- a/src/test/ui/borrowck/borrowck-drop-from-guard.stderr
+++ b/src/test/ui/borrowck/borrowck-drop-from-guard.stderr
@@ -9,6 +9,11 @@ LL |         Some(_) if { drop(my_str); false } => {}
 LL |         Some(_) => {}
 LL |         None => { foo(my_str); }
    |                       ^^^^^^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         Some(_) if { drop(my_str.clone()); false } => {}
+   |                                 ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/borrowck/borrowck-loan-in-overloaded-op.stderr b/src/test/ui/borrowck/borrowck-loan-in-overloaded-op.stderr
index 0dd720ff6ce04..e1b9916208805 100644
--- a/src/test/ui/borrowck/borrowck-loan-in-overloaded-op.stderr
+++ b/src/test/ui/borrowck/borrowck-loan-in-overloaded-op.stderr
@@ -7,6 +7,11 @@ LL |     let _y = {x} + x.clone(); // the `{x}` forces a move to occur
    |               -    ^^^^^^^^^ value borrowed here after move
    |               |
    |               value moved here
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = {x.clone()} + x.clone(); // the `{x}` forces a move to occur
+   |                ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/borrowck/borrowck-move-out-from-array-match.stderr b/src/test/ui/borrowck/borrowck-move-out-from-array-match.stderr
index 346b82a266644..67b00c1dd90ce 100644
--- a/src/test/ui/borrowck/borrowck-move-out-from-array-match.stderr
+++ b/src/test/ui/borrowck/borrowck-move-out-from-array-match.stderr
@@ -8,6 +8,10 @@ LL |         [.., _y] => {}
    |              ^^ value used here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-match.rs:23:14
@@ -19,6 +23,10 @@ LL |         [.., _y] => {}
    |              ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: use of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array-match.rs:33:15
@@ -30,6 +38,10 @@ LL |         [.., (_y, _)] => {}
    |               ^^ value used here after move
    |
    = note: move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-match.rs:44:11
@@ -41,6 +53,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _x, _, _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-match.rs:55:11
@@ -52,6 +68,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., ref _x] => {}
+   |              +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-match.rs:66:11
@@ -63,6 +83,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [(ref _x, _), _, _] => {}
+   |           +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-match.rs:77:11
@@ -74,6 +98,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., (ref _x, _)] => {}
+   |               +++
 
 error[E0382]: use of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array-match.rs:89:11
@@ -85,6 +113,10 @@ LL |         [(_x, _), _, _] => {}
    |           ^^ value used here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _y @ .., _, _] => {}
+   |          +++
 
 error[E0382]: use of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array-match.rs:99:15
@@ -96,6 +128,10 @@ LL |         [.., (_x, _)] => {}
    |               ^^ value used here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _y @ ..] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-match.rs:110:11
@@ -107,6 +143,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref x @ .., _] => {}
+   |          +++
 
 error: aborting due to 10 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-move-out-from-array-no-overlap-match.stderr b/src/test/ui/borrowck/borrowck-move-out-from-array-no-overlap-match.stderr
index 6c6a25c251e70..47429ea3eebae 100644
--- a/src/test/ui/borrowck/borrowck-move-out-from-array-no-overlap-match.stderr
+++ b/src/test/ui/borrowck/borrowck-move-out-from-array-no-overlap-match.stderr
@@ -8,6 +8,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:28:11
@@ -19,6 +23,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:41:11
@@ -30,6 +38,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _x, _, _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:52:11
@@ -41,6 +53,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., ref _x] => {}
+   |              +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:63:11
@@ -52,6 +68,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [(ref _x, _), _, _] => {}
+   |           +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:74:11
@@ -63,6 +83,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., (ref _x, _)] => {}
+   |               +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:85:11
@@ -74,6 +98,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, ref _y @ ..] => {}
+   |             +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:96:11
@@ -85,6 +113,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _y @ .., _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-no-overlap-match.rs:109:11
@@ -96,6 +128,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref x @ .., _, _] => {}
+   |          +++
 
 error: aborting due to 9 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-move-out-from-array-use-match.stderr b/src/test/ui/borrowck/borrowck-move-out-from-array-use-match.stderr
index 77702e145df81..bfab13d42d2a1 100644
--- a/src/test/ui/borrowck/borrowck-move-out-from-array-use-match.stderr
+++ b/src/test/ui/borrowck/borrowck-move-out-from-array-use-match.stderr
@@ -8,6 +8,10 @@ LL |         [.., ref _y] => {}
    |              ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x] => {}
+   |                +++
 
 error[E0382]: borrow of partially moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:23:14
@@ -19,6 +23,10 @@ LL |         [.., ref _y] => {}
    |              ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: borrow of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:33:15
@@ -30,6 +38,10 @@ LL |         [.., (ref _y, _)] => {}
    |               ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:44:11
@@ -41,6 +53,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _x, _, _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:55:11
@@ -52,6 +68,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., ref _x] => {}
+   |              +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:66:11
@@ -63,6 +83,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [(ref _x, _), _, _] => {}
+   |           +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:77:11
@@ -74,6 +98,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., (ref _x, _)] => {}
+   |               +++
 
 error[E0382]: borrow of moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:89:11
@@ -85,6 +113,10 @@ LL |         [(ref _x, _), _, _] => {}
    |           ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _y @ .., _, _] => {}
+   |          +++
 
 error[E0382]: borrow of moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:99:15
@@ -96,6 +128,10 @@ LL |         [.., (ref _x, _)] => {}
    |               ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _y @ ..] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:110:11
@@ -107,6 +143,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref x @ .., _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:123:5
@@ -118,6 +158,10 @@ LL |     a[2] = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:131:5
@@ -129,6 +173,10 @@ LL |     a[2].1 = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:139:5
@@ -140,6 +188,10 @@ LL |     a[0] = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x @ ..] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-match.rs:147:5
@@ -151,6 +203,10 @@ LL |     a[0].1 = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x @ ..] => {}
+   |                +++
 
 error: aborting due to 14 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-move-out-from-array-use-no-overlap-match.stderr b/src/test/ui/borrowck/borrowck-move-out-from-array-use-no-overlap-match.stderr
index 6cc2c2f7a984c..8412c24fe6112 100644
--- a/src/test/ui/borrowck/borrowck-move-out-from-array-use-no-overlap-match.stderr
+++ b/src/test/ui/borrowck/borrowck-move-out-from-array-use-no-overlap-match.stderr
@@ -8,6 +8,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, ref _x] => {}
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:28:11
@@ -19,6 +23,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, _, (ref _x, _)] => {}
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:41:11
@@ -30,6 +38,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _x, _, _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:52:11
@@ -41,6 +53,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., ref _x] => {}
+   |              +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:63:11
@@ -52,6 +68,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [(ref _x, _), _, _] => {}
+   |           +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:74:11
@@ -63,6 +83,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [.., (ref _x, _)] => {}
+   |               +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:85:11
@@ -74,6 +98,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [_, ref _y @ ..] => {}
+   |             +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:96:11
@@ -85,6 +113,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref _y @ .., _] => {}
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use-no-overlap-match.rs:109:11
@@ -96,6 +128,10 @@ LL |     match a {
    |           ^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         [ref x @ .., _, _] => {}
+   |          +++
 
 error: aborting due to 9 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-move-out-from-array-use.stderr b/src/test/ui/borrowck/borrowck-move-out-from-array-use.stderr
index 9add7553afa70..e2aeaafc63c25 100644
--- a/src/test/ui/borrowck/borrowck-move-out-from-array-use.stderr
+++ b/src/test/ui/borrowck/borrowck-move-out-from-array-use.stderr
@@ -7,6 +7,10 @@ LL |     let [.., ref _y] = a;
    |              ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _x] = a;
+   |                +++
 
 error[E0382]: borrow of partially moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-use.rs:16:14
@@ -17,6 +21,10 @@ LL |     let [.., ref _y] = a;
    |              ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, (ref _x, _)] = a;
+   |                 +++
 
 error[E0382]: borrow of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array-use.rs:22:15
@@ -27,6 +35,10 @@ LL |     let [.., (ref _y, _)] = a;
    |               ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, (ref _x, _)] = a;
+   |                 +++
 
 error[E0382]: borrow of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:30:10
@@ -37,6 +49,10 @@ LL |     let [ref _y @ .., _, _] = a;
    |          ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [ref _x, _, _] = a;
+   |          +++
 
 error[E0382]: borrow of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:36:16
@@ -47,6 +63,10 @@ LL |     let [_, _, ref _y @ ..] = a;
    |                ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [.., ref _x] = a;
+   |              +++
 
 error[E0382]: borrow of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:42:10
@@ -57,6 +77,10 @@ LL |     let [ref _y @ .., _, _] = a;
    |          ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [(ref _x, _), _, _] = a;
+   |           +++
 
 error[E0382]: borrow of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:48:16
@@ -67,6 +91,10 @@ LL |     let [_, _, ref _y @ ..] = a;
    |                ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [.., (ref _x, _)] = a;
+   |               +++
 
 error[E0382]: borrow of moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-use.rs:54:11
@@ -77,6 +105,10 @@ LL |     let [(ref _x, _), _, _] = a;
    |           ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [ref _y @ .., _, _] = a;
+   |          +++
 
 error[E0382]: borrow of moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array-use.rs:60:15
@@ -87,6 +119,10 @@ LL |     let [.., (ref _x, _)] = a;
    |               ^^^^^^ value borrowed here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _y @ ..] = a;
+   |                +++
 
 error[E0382]: borrow of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:68:13
@@ -97,6 +133,10 @@ LL |     let [_, ref _y @ ..] = a;
    |             ^^^^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [ref x @ .., _] = a;
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:76:5
@@ -107,6 +147,10 @@ LL |     a[2] = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _x] = a;
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:82:5
@@ -117,6 +161,10 @@ LL |     a[2].1 = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, (ref _x, _)] = a;
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:88:5
@@ -127,6 +175,10 @@ LL |     a[0] = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _x @ ..] = a;
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array-use.rs:94:5
@@ -137,6 +189,10 @@ LL |     a[0].1 = Default::default();
    |     ^^^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _x @ ..] = a;
+   |                +++
 
 error: aborting due to 14 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-move-out-from-array.stderr b/src/test/ui/borrowck/borrowck-move-out-from-array.stderr
index 363effcfe5322..dd456681f57bc 100644
--- a/src/test/ui/borrowck/borrowck-move-out-from-array.stderr
+++ b/src/test/ui/borrowck/borrowck-move-out-from-array.stderr
@@ -7,6 +7,10 @@ LL |     let [.., _y] = a;
    |              ^^ value used here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _x] = a;
+   |                +++
 
 error[E0382]: use of partially moved value: `a[..]`
   --> $DIR/borrowck-move-out-from-array.rs:16:14
@@ -17,6 +21,10 @@ LL |     let [.., _y] = a;
    |              ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, (ref _x, _)] = a;
+   |                 +++
 
 error[E0382]: use of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array.rs:22:15
@@ -27,6 +35,10 @@ LL |     let [.., (_y, _)] = a;
    |               ^^ value used here after move
    |
    = note: move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, (ref _x, _)] = a;
+   |                 +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array.rs:30:10
@@ -37,6 +49,10 @@ LL |     let [_y @ .., _, _] = a;
    |          ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [ref _x, _, _] = a;
+   |          +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array.rs:36:16
@@ -47,6 +63,10 @@ LL |     let [_, _, _y @ ..] = a;
    |                ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [.., ref _x] = a;
+   |              +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array.rs:42:10
@@ -57,6 +77,10 @@ LL |     let [_y @ .., _, _] = a;
    |          ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [(ref _x, _), _, _] = a;
+   |           +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array.rs:48:16
@@ -67,6 +91,10 @@ LL |     let [_, _, _y @ ..] = a;
    |                ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..].0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [.., (ref _x, _)] = a;
+   |               +++
 
 error[E0382]: use of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array.rs:54:11
@@ -77,6 +105,10 @@ LL |     let [(_x, _), _, _] = a;
    |           ^^ value used here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [ref _y @ .., _, _] = a;
+   |          +++
 
 error[E0382]: use of moved value: `a[..].0`
   --> $DIR/borrowck-move-out-from-array.rs:60:15
@@ -87,6 +119,10 @@ LL |     let [.., (_x, _)] = a;
    |               ^^ value used here after move
    |
    = note: move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [_, _, ref _y @ ..] = a;
+   |                +++
 
 error[E0382]: use of partially moved value: `a`
   --> $DIR/borrowck-move-out-from-array.rs:68:13
@@ -97,6 +133,10 @@ LL |     let [_, _y @ ..] = a;
    |             ^^ value used here after partial move
    |
    = note: partial move occurs because `a[..]` has type `(String, String)`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let [ref x @ .., _] = a;
+   |          +++
 
 error: aborting due to 10 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-multiple-captures.stderr b/src/test/ui/borrowck/borrowck-multiple-captures.stderr
index 86d2955e2364f..f94cbc30db421 100644
--- a/src/test/ui/borrowck/borrowck-multiple-captures.stderr
+++ b/src/test/ui/borrowck/borrowck-multiple-captures.stderr
@@ -40,6 +40,11 @@ LL |     thread::spawn(move|| {
 ...
 LL |         drop(x1);
    |              -- use occurs due to use in closure
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     drop(x1.clone());
+   |            ++++++++
 
 error[E0382]: use of moved value: `x2`
   --> $DIR/borrowck-multiple-captures.rs:27:19
@@ -53,6 +58,11 @@ LL |     thread::spawn(move|| {
 ...
 LL |         drop(x2);
    |              -- use occurs due to use in closure
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     drop(x2.clone());
+   |            ++++++++
 
 error[E0382]: use of moved value: `x`
   --> $DIR/borrowck-multiple-captures.rs:41:14
@@ -100,6 +110,11 @@ LL |     thread::spawn(move|| {
 LL |
 LL |         drop(x);
    |              - use occurs due to use in closure
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     drop(x.clone());
+   |           ++++++++
 
 error: aborting due to 8 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-overloaded-index-move-index.stderr b/src/test/ui/borrowck/borrowck-overloaded-index-move-index.stderr
index e01c26adcfc2d..fb0e274c2919a 100644
--- a/src/test/ui/borrowck/borrowck-overloaded-index-move-index.stderr
+++ b/src/test/ui/borrowck/borrowck-overloaded-index-move-index.stderr
@@ -33,6 +33,11 @@ LL |     println!("{}", f[s]);
 ...
 LL |     f[s] = 10;
    |       ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     println!("{}", f[s.clone()]);
+   |                       ++++++++
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/borrowck/borrowck-reinit.stderr b/src/test/ui/borrowck/borrowck-reinit.stderr
index 22253cd96f1a6..f785900d53fc0 100644
--- a/src/test/ui/borrowck/borrowck-reinit.stderr
+++ b/src/test/ui/borrowck/borrowck-reinit.stderr
@@ -8,6 +8,11 @@ LL |     drop(x);
    |          - value moved here
 LL |     let _ = (1,x);
    |                ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     drop(x.clone());
+   |           ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/borrowck/issue-31287-drop-in-guard.stderr b/src/test/ui/borrowck/issue-31287-drop-in-guard.stderr
index d33115988a9a8..ad898fcabd9db 100644
--- a/src/test/ui/borrowck/issue-31287-drop-in-guard.stderr
+++ b/src/test/ui/borrowck/issue-31287-drop-in-guard.stderr
@@ -8,6 +8,11 @@ LL |         Some(_) if { drop(a); false } => None,
    |                           - value moved here
 LL |         x => x,
    |         ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         Some(_) if { drop(a.clone()); false } => None,
+   |                            ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/borrowck/issue-41962.stderr b/src/test/ui/borrowck/issue-41962.stderr
index b20cc6d8cf59f..716cc9d0c8ba2 100644
--- a/src/test/ui/borrowck/issue-41962.stderr
+++ b/src/test/ui/borrowck/issue-41962.stderr
@@ -5,7 +5,7 @@ LL |         if let Some(thing) = maybe {
    |                     ^^^^^ value moved here, in previous iteration of loop
    |
    = note: move occurs because value has type `Vec<bool>`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `maybe.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         if let Some(ref thing) = maybe {
    |                     +++
diff --git a/src/test/ui/borrowck/issue-83760.stderr b/src/test/ui/borrowck/issue-83760.stderr
index beeda5685dc09..2552fff860cd3 100644
--- a/src/test/ui/borrowck/issue-83760.stderr
+++ b/src/test/ui/borrowck/issue-83760.stderr
@@ -8,6 +8,10 @@ LL |             val = None;
    |             ---------- this reinitialization might get skipped
    |
    = note: move occurs because value has type `Struct`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     while let Some(ref foo) = val {
+   |                    +++
 
 error[E0382]: use of moved value: `foo`
   --> $DIR/issue-83760.rs:21:14
diff --git a/src/test/ui/borrowck/move-in-pattern-mut-in-loop.stderr b/src/test/ui/borrowck/move-in-pattern-mut-in-loop.stderr
index c6931ba72579b..55948afca733b 100644
--- a/src/test/ui/borrowck/move-in-pattern-mut-in-loop.stderr
+++ b/src/test/ui/borrowck/move-in-pattern-mut-in-loop.stderr
@@ -5,7 +5,7 @@ LL |         if let Some(mut _x) = opt {}
    |                     ^^^^^^ value moved here, in previous iteration of loop
    |
    = note: move occurs because value has type `&mut i32`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `opt.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         if let Some(ref mut _x) = opt {}
    |                     +++
diff --git a/src/test/ui/borrowck/move-in-pattern-mut.stderr b/src/test/ui/borrowck/move-in-pattern-mut.stderr
index 2bf34b32176c0..dd3471e2c8be5 100644
--- a/src/test/ui/borrowck/move-in-pattern-mut.stderr
+++ b/src/test/ui/borrowck/move-in-pattern-mut.stderr
@@ -8,7 +8,7 @@ LL |     foo(s);
    |         ^ value used here after partial move
    |
    = note: partial move occurs because value has type `S`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `s.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |     if let Some(ref mut x) = s {
    |                 +++
@@ -23,7 +23,7 @@ LL |     bar(e);
    |         ^ value used here after partial move
    |
    = note: partial move occurs because value has type `S`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `e.s`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |     let E::V { s: ref mut x } = e;
    |                   +++
diff --git a/src/test/ui/borrowck/move-in-pattern.stderr b/src/test/ui/borrowck/move-in-pattern.stderr
index 6b84c0032cdde..250acbe5928a0 100644
--- a/src/test/ui/borrowck/move-in-pattern.stderr
+++ b/src/test/ui/borrowck/move-in-pattern.stderr
@@ -8,7 +8,7 @@ LL |     foo(s);
    |         ^ value used here after partial move
    |
    = note: partial move occurs because value has type `S`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `s.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |     if let Some(ref x) = s {
    |                 +++
@@ -23,7 +23,7 @@ LL |     bar(e);
    |         ^ value used here after partial move
    |
    = note: partial move occurs because value has type `S`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `e.s`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |     let E::V { s: ref x } = e;
    |                   +++
diff --git a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
index 8b05b23882273..eaf53868014fa 100644
--- a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
+++ b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
@@ -4,9 +4,17 @@ error[E0382]: use of moved value: `value`
 LL | fn this_does_not<'a, R>(value: &'a mut Events<R>) {
    |                         ----- move occurs because `value` has type `&mut Events<R>`, which does not implement the `Copy` trait
 LL |     for _ in 0..3 {
+   |     ------------- inside of this loop
 LL |         Other::handle(value);
    |                       ^^^^^ value moved here, in previous iteration of loop
    |
+note: consider changing this parameter type in `handle` to borrow instead if ownering the value isn't necessary
+  --> $DIR/mut-borrow-in-loop-2.rs:9:22
+   |
+LL |     fn handle(value: T) -> Self;
+   |        ------        ^ this type parameter takes ownership of the value
+   |        |
+   |        in this function
 help: consider creating a fresh reborrow of `value` here
    |
 LL |         Other::handle(&mut *value);
diff --git a/src/test/ui/borrowck/or-patterns.stderr b/src/test/ui/borrowck/or-patterns.stderr
index dd5797c3f79cc..9501798bb06d0 100644
--- a/src/test/ui/borrowck/or-patterns.stderr
+++ b/src/test/ui/borrowck/or-patterns.stderr
@@ -8,6 +8,10 @@ LL |     &x.0 .0;
    |     ^^^^^^^ value borrowed here after move
    |
    = note: move occurs because `x.0.0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ((ref y, _) | (_, y),) => (),
+   |           +++
 
 error[E0382]: borrow of moved value: `x.0.1`
   --> $DIR/or-patterns.rs:10:5
@@ -19,6 +23,10 @@ LL |     &x.0 .1;
    |     ^^^^^^^ value borrowed here after move
    |
    = note: move occurs because `x.0.1` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ((y, _) | (_, ref y),) => (),
+   |                       +++
 
 error[E0502]: cannot borrow `x.0.0` as mutable because it is also borrowed as immutable
   --> $DIR/or-patterns.rs:18:5
@@ -77,6 +85,10 @@ LL |     &x.0 .0;
    |     ^^^^^^^ value borrowed here after move
    |
    = note: move occurs because `x.0.0` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ((ref y, _) | (_, y),) = x;
+   |           +++
 
 error[E0382]: borrow of moved value: `x.0.1`
   --> $DIR/or-patterns.rs:40:5
@@ -88,6 +100,10 @@ LL |     &x.0 .1;
    |     ^^^^^^^ value borrowed here after move
    |
    = note: move occurs because `x.0.1` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ((y, _) | (_, ref y),) = x;
+   |                       +++
 
 error[E0502]: cannot borrow `x.0.0` as mutable because it is also borrowed as immutable
   --> $DIR/or-patterns.rs:46:5
diff --git a/src/test/ui/closure_context/issue-42065.stderr b/src/test/ui/closure_context/issue-42065.stderr
index 896bb6dc6bee8..4e436ca7c03f5 100644
--- a/src/test/ui/closure_context/issue-42065.stderr
+++ b/src/test/ui/closure_context/issue-42065.stderr
@@ -16,6 +16,10 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     debug_dump_dict();
    |     ^^^^^^^^^^^^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     debug_dump_dict.clone()();
+   |                    ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/codemap_tests/tab_3.stderr b/src/test/ui/codemap_tests/tab_3.stderr
index 9072cc925ffff..080f6c39449f0 100644
--- a/src/test/ui/codemap_tests/tab_3.stderr
+++ b/src/test/ui/codemap_tests/tab_3.stderr
@@ -15,6 +15,10 @@ note: this function takes ownership of the receiver `self`, which moves `some_ve
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     some_vec.clone().into_iter();
+   |             ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/drop/repeat-drop-2.stderr b/src/test/ui/drop/repeat-drop-2.stderr
index 7357551c4a7f6..f030228f71ae4 100644
--- a/src/test/ui/drop/repeat-drop-2.stderr
+++ b/src/test/ui/drop/repeat-drop-2.stderr
@@ -7,6 +7,11 @@ LL |     let _bar = foo;
    |                --- value moved here
 LL |     let _baz = [foo; 0];
    |                 ^^^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _bar = foo.clone();
+   |                   ++++++++
 
 error[E0493]: destructor of `String` cannot be evaluated at compile-time
   --> $DIR/repeat-drop-2.rs:7:25
diff --git a/src/test/ui/issues/issue-29723.stderr b/src/test/ui/issues/issue-29723.stderr
index e39ddfc81c968..92ee5cf22b719 100644
--- a/src/test/ui/issues/issue-29723.stderr
+++ b/src/test/ui/issues/issue-29723.stderr
@@ -9,6 +9,11 @@ LL |         0 if { drop(s); false } => String::from("oops"),
 ...
 LL |             s
    |             ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         0 if { drop(s.clone()); false } => String::from("oops"),
+   |                      ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-42796.stderr b/src/test/ui/issues/issue-42796.stderr
index f3e0e7b20a178..f2971df5db275 100644
--- a/src/test/ui/issues/issue-42796.stderr
+++ b/src/test/ui/issues/issue-42796.stderr
@@ -10,6 +10,10 @@ LL |     println!("{}", s);
    |                    ^ value borrowed here after move
    |
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let mut s_copy = s.clone();
+   |                       ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-61108.stderr b/src/test/ui/issues/issue-61108.stderr
index e5b671d7b7ab0..0f6f30531b332 100644
--- a/src/test/ui/issues/issue-61108.stderr
+++ b/src/test/ui/issues/issue-61108.stderr
@@ -14,6 +14,10 @@ note: this function takes ownership of the receiver `self`, which moves `bad_let
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     for l in bad_letters.clone() {
+   |                         ++++++++
 help: consider iterating over a slice of the `Vec<char>`'s content to avoid moving into the `for` loop
    |
 LL |     for l in &bad_letters {
diff --git a/src/test/ui/issues/issue-64559.stderr b/src/test/ui/issues/issue-64559.stderr
index ef178bbd15538..5c04cefa5304b 100644
--- a/src/test/ui/issues/issue-64559.stderr
+++ b/src/test/ui/issues/issue-64559.stderr
@@ -15,6 +15,10 @@ note: this function takes ownership of the receiver `self`, which moves `orig`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     for _val in orig.clone() {}
+   |                     ++++++++
 help: consider iterating over a slice of the `Vec<bool>`'s content to avoid moving into the `for` loop
    |
 LL |     for _val in &orig {}
diff --git a/src/test/ui/liveness/liveness-move-call-arg.stderr b/src/test/ui/liveness/liveness-move-call-arg.stderr
index 7c0e916eddcaa..bd45aa5345885 100644
--- a/src/test/ui/liveness/liveness-move-call-arg.stderr
+++ b/src/test/ui/liveness/liveness-move-call-arg.stderr
@@ -3,9 +3,23 @@ error[E0382]: use of moved value: `x`
    |
 LL |     let x: Box<isize> = Box::new(25);
    |         - move occurs because `x` has type `Box<isize>`, which does not implement the `Copy` trait
-...
+LL |
+LL |     loop {
+   |     ---- inside of this loop
 LL |         take(x);
    |              ^ value moved here, in previous iteration of loop
+   |
+note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+  --> $DIR/liveness-move-call-arg.rs:1:13
+   |
+LL | fn take(_x: Box<isize>) {}
+   |    ----     ^^^^^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         take(x.clone());
+   |               ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/liveness/liveness-move-in-loop.stderr b/src/test/ui/liveness/liveness-move-in-loop.stderr
index 832d4f8fa030f..a060914f17859 100644
--- a/src/test/ui/liveness/liveness-move-in-loop.stderr
+++ b/src/test/ui/liveness/liveness-move-in-loop.stderr
@@ -4,8 +4,22 @@ error[E0382]: use of moved value: `y`
 LL |     let y: Box<isize> = 42.into();
    |         - move occurs because `y` has type `Box<isize>`, which does not implement the `Copy` trait
 ...
+LL |     loop {
+   |     ---- inside of this loop
+LL |         println!("{}", y);
+LL |         loop {
+   |         ---- inside of this loop
+LL |             loop {
+   |             ---- inside of this loop
+LL |                 loop {
+   |                 ---- inside of this loop
 LL |                     x = y;
    |                         ^ value moved here, in previous iteration of loop
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |                     x = y.clone();
+   |                          ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/liveness/liveness-move-in-while.stderr b/src/test/ui/liveness/liveness-move-in-while.stderr
index b04a05fe40906..4dff7447dd766 100644
--- a/src/test/ui/liveness/liveness-move-in-while.stderr
+++ b/src/test/ui/liveness/liveness-move-in-while.stderr
@@ -24,12 +24,22 @@ error[E0382]: borrow of moved value: `y`
 LL |     let y: Box<isize> = 42.into();
    |         - move occurs because `y` has type `Box<isize>`, which does not implement the `Copy` trait
 ...
+LL |     loop {
+   |     ---- inside of this loop
 LL |         println!("{}", y);
    |                        ^ value borrowed here after move
 LL |         while true { while true { while true { x = y; x.clone(); } } }
-   |                                                    - value moved here, in previous iteration of loop
+   |         ----------   ----------   ----------       - value moved here, in previous iteration of loop
+   |         |            |            |
+   |         |            |            inside of this loop
+   |         |            inside of this loop
+   |         inside of this loop
    |
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         while true { while true { while true { x = y.clone(); x.clone(); } } }
+   |                                                     ++++++++
 
 error: aborting due to previous error; 3 warnings emitted
 
diff --git a/src/test/ui/liveness/liveness-use-after-move.stderr b/src/test/ui/liveness/liveness-use-after-move.stderr
index 218b93c8e4f45..3accba197a13d 100644
--- a/src/test/ui/liveness/liveness-use-after-move.stderr
+++ b/src/test/ui/liveness/liveness-use-after-move.stderr
@@ -10,6 +10,10 @@ LL |     println!("{}", *x);
    |                    ^^ value borrowed here after move
    |
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let y = x.clone();
+   |              ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/liveness/liveness-use-after-send.stderr b/src/test/ui/liveness/liveness-use-after-send.stderr
index 8edc0463fe571..c407827d32050 100644
--- a/src/test/ui/liveness/liveness-use-after-send.stderr
+++ b/src/test/ui/liveness/liveness-use-after-send.stderr
@@ -8,7 +8,16 @@ LL |     send(ch, message);
 LL |     println!("{}", message);
    |                    ^^^^^^^ value borrowed here after move
    |
+note: consider changing this parameter type in `send` to borrow instead if ownering the value isn't necessary
+  --> $DIR/liveness-use-after-send.rs:3:54
+   |
+LL | fn send<T:Send + std::fmt::Debug>(ch: Chan<T>, data: T) {
+   |    ---- in this function                             ^ this type parameter takes ownership of the value
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     send(ch, message.clone());
+   |                     ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/borrow-closures-instead-of-move.stderr b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
index 3146b6959001e..11fcb1cc26381 100644
--- a/src/test/ui/moves/borrow-closures-instead-of-move.stderr
+++ b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
@@ -4,9 +4,17 @@ error[E0382]: use of moved value: `f`
 LL | fn takes_fn(f: impl Fn()) {
    |             - move occurs because `f` has type `impl Fn()`, which does not implement the `Copy` trait
 LL |     loop {
+   |     ---- inside of this loop
 LL |         takes_fnonce(f);
    |                      ^ value moved here, in previous iteration of loop
    |
+note: consider changing this parameter type in `takes_fnonce` to borrow instead if ownering the value isn't necessary
+  --> $DIR/borrow-closures-instead-of-move.rs:34:20
+   |
+LL | fn takes_fnonce(_: impl FnOnce()) {}
+   |    ------------    ^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 help: consider borrowing `f`
    |
 LL |         takes_fnonce(&f);
@@ -24,6 +32,13 @@ LL |         takes_fnonce(m);
 LL |     takes_fnonce(m);
    |                  ^ value used here after move
    |
+note: consider changing this parameter type in `takes_fnonce` to borrow instead if ownering the value isn't necessary
+  --> $DIR/borrow-closures-instead-of-move.rs:34:20
+   |
+LL | fn takes_fnonce(_: impl FnOnce()) {}
+   |    ------------    ^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 help: consider mutably borrowing `m`
    |
 LL |         takes_fnonce(&mut m);
@@ -43,6 +58,13 @@ note: closure cannot be moved more than once as it is not `Copy` due to moving t
    |
 LL |         x += 1;
    |         ^
+note: consider changing this parameter type in `takes_fnonce` to borrow instead if ownering the value isn't necessary
+  --> $DIR/borrow-closures-instead-of-move.rs:34:20
+   |
+LL | fn takes_fnonce(_: impl FnOnce()) {}
+   |    ------------    ^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 help: consider mutably borrowing `closure`
    |
 LL |     takes_fnonce(&mut closure);
diff --git a/src/test/ui/moves/issue-46099-move-in-macro.stderr b/src/test/ui/moves/issue-46099-move-in-macro.stderr
index baa87e3e9fdb2..94bc9e6f45465 100644
--- a/src/test/ui/moves/issue-46099-move-in-macro.stderr
+++ b/src/test/ui/moves/issue-46099-move-in-macro.stderr
@@ -5,6 +5,11 @@ LL |     let b = Box::new(true);
    |         - move occurs because `b` has type `Box<bool>`, which does not implement the `Copy` trait
 LL |     test!({b});
    |            ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     test!({b.clone()});
+   |             ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/issue-72649-uninit-in-loop.rs b/src/test/ui/moves/issue-72649-uninit-in-loop.rs
index d76b69ecdc8bb..56c225bab8cbc 100644
--- a/src/test/ui/moves/issue-72649-uninit-in-loop.rs
+++ b/src/test/ui/moves/issue-72649-uninit-in-loop.rs
@@ -25,7 +25,7 @@ fn moved_here_1() {
 fn moved_here_2() {
     let value = NonCopy{};
     //~^ NOTE move occurs because `value` has type `NonCopy`, which does not implement the `Copy` trait
-    loop {
+    loop { //~ NOTE inside of this loop
         let _used = value;
         //~^ NOTE value moved here
         loop {
@@ -38,7 +38,7 @@ fn moved_here_2() {
 fn moved_loop_1() {
     let value = NonCopy{};
     //~^ NOTE move occurs because `value` has type `NonCopy`, which does not implement the `Copy` trait
-    loop {
+    loop { //~ NOTE inside of this loop
         let _used = value; //~ ERROR use of moved value: `value`
         //~^ NOTE value moved here, in previous iteration of loop
     }
@@ -49,7 +49,7 @@ fn moved_loop_2() {
     //~^ NOTE move occurs because `value` has type `NonCopy`, which does not implement the `Copy` trait
     let _used = value;
     value = NonCopy{};
-    loop {
+    loop { //~ NOTE inside of this loop
         let _used2 = value; //~ ERROR use of moved value: `value`
         //~^ NOTE value moved here, in previous iteration of loop
     }
diff --git a/src/test/ui/moves/issue-72649-uninit-in-loop.stderr b/src/test/ui/moves/issue-72649-uninit-in-loop.stderr
index 974994223a3fd..7e119fe8cda64 100644
--- a/src/test/ui/moves/issue-72649-uninit-in-loop.stderr
+++ b/src/test/ui/moves/issue-72649-uninit-in-loop.stderr
@@ -15,7 +15,9 @@ error[E0382]: use of moved value: `value`
    |
 LL |     let value = NonCopy{};
    |         ----- move occurs because `value` has type `NonCopy`, which does not implement the `Copy` trait
-...
+LL |
+LL |     loop {
+   |     ---- inside of this loop
 LL |         let _used = value;
    |                     ----- value moved here
 ...
@@ -27,7 +29,9 @@ error[E0382]: use of moved value: `value`
    |
 LL |     let value = NonCopy{};
    |         ----- move occurs because `value` has type `NonCopy`, which does not implement the `Copy` trait
-...
+LL |
+LL |     loop {
+   |     ---- inside of this loop
 LL |         let _used = value;
    |                     ^^^^^ value moved here, in previous iteration of loop
 
@@ -37,6 +41,8 @@ error[E0382]: use of moved value: `value`
 LL |     let mut value = NonCopy{};
    |         --------- move occurs because `value` has type `NonCopy`, which does not implement the `Copy` trait
 ...
+LL |     loop {
+   |     ---- inside of this loop
 LL |         let _used2 = value;
    |                      ^^^^^ value moved here, in previous iteration of loop
 
diff --git a/src/test/ui/moves/move-fn-self-receiver.stderr b/src/test/ui/moves/move-fn-self-receiver.stderr
index 3a686121a9283..b331b10a3b79e 100644
--- a/src/test/ui/moves/move-fn-self-receiver.stderr
+++ b/src/test/ui/moves/move-fn-self-receiver.stderr
@@ -96,6 +96,10 @@ note: this function takes ownership of the receiver `self`, which moves `rc_foo`
    |
 LL |     fn use_rc_self(self: Rc<Self>) {}
    |                    ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     rc_foo.clone().use_rc_self();
+   |           ++++++++
 
 error[E0382]: use of moved value: `foo_add`
   --> $DIR/move-fn-self-receiver.rs:59:5
@@ -123,6 +127,10 @@ LL |     for _val in implicit_into_iter {}
 LL |     implicit_into_iter;
    |     ^^^^^^^^^^^^^^^^^^ value used here after move
    |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     for _val in implicit_into_iter.clone() {}
+   |                                   ++++++++
 help: consider iterating over a slice of the `Vec<bool>`'s content to avoid moving into the `for` loop
    |
 LL |     for _val in &implicit_into_iter {}
@@ -137,6 +145,11 @@ LL |     for _val in explicit_into_iter.into_iter() {}
    |                                    ----------- `explicit_into_iter` moved due to this method call
 LL |     explicit_into_iter;
    |     ^^^^^^^^^^^^^^^^^^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     for _val in explicit_into_iter.clone().into_iter() {}
+   |                                   ++++++++
 
 error[E0382]: use of moved value: `container`
   --> $DIR/move-fn-self-receiver.rs:71:5
@@ -160,6 +173,7 @@ error[E0382]: use of moved value: `foo2`
 LL |     let foo2 = Foo;
    |         ---- move occurs because `foo2` has type `Foo`, which does not implement the `Copy` trait
 LL |     loop {
+   |     ---- inside of this loop
 LL |         foo2.use_self();
    |         ^^^^ ---------- `foo2` moved due to this method call, in previous iteration of loop
 
diff --git a/src/test/ui/moves/move-guard-same-consts.stderr b/src/test/ui/moves/move-guard-same-consts.stderr
index 2048fefefa31b..04a41b9ce2623 100644
--- a/src/test/ui/moves/move-guard-same-consts.stderr
+++ b/src/test/ui/moves/move-guard-same-consts.stderr
@@ -8,6 +8,18 @@ LL |         (1, 2) if take(x) => (),
    |                        - value moved here
 LL |         (1, 2) if take(x) => (),
    |                        ^ value used here after move
+   |
+note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+  --> $DIR/move-guard-same-consts.rs:25:15
+   |
+LL | fn take<T>(_: T) -> bool { false }
+   |    ----       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         (1, 2) if take(x.clone()) => (),
+   |                         ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/move-in-guard-1.stderr b/src/test/ui/moves/move-in-guard-1.stderr
index 5e9aa66b90dae..d435426f2ec97 100644
--- a/src/test/ui/moves/move-in-guard-1.stderr
+++ b/src/test/ui/moves/move-in-guard-1.stderr
@@ -8,6 +8,18 @@ LL |         (1, _) if take(x) => (),
    |                        - value moved here
 LL |         (_, 2) if take(x) => (),
    |                        ^ value used here after move
+   |
+note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+  --> $DIR/move-in-guard-1.rs:15:15
+   |
+LL | fn take<T>(_: T) -> bool { false }
+   |    ----       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         (1, _) if take(x.clone()) => (),
+   |                         ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/move-in-guard-2.stderr b/src/test/ui/moves/move-in-guard-2.stderr
index 8d636c11b78c7..0f4895c2ac132 100644
--- a/src/test/ui/moves/move-in-guard-2.stderr
+++ b/src/test/ui/moves/move-in-guard-2.stderr
@@ -6,6 +6,18 @@ LL |     let x: Box<_> = Box::new(1);
 ...
 LL |         (_, 2) if take(x) => (),
    |                        ^ value used here after move
+   |
+note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+  --> $DIR/move-in-guard-2.rs:13:15
+   |
+LL | fn take<T>(_: T) -> bool { false }
+   |    ----       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         (_, 2) if take(x.clone()) => (),
+   |                         ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/moves-based-on-type-access-to-field.stderr b/src/test/ui/moves/moves-based-on-type-access-to-field.stderr
index 3cc8ca29144ca..a49ee31b46622 100644
--- a/src/test/ui/moves/moves-based-on-type-access-to-field.stderr
+++ b/src/test/ui/moves/moves-based-on-type-access-to-field.stderr
@@ -13,6 +13,10 @@ note: this function takes ownership of the receiver `self`, which moves `x`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     consume(x.clone().into_iter().next().unwrap());
+   |              ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/moves-based-on-type-cyclic-types-issue-4821.stderr b/src/test/ui/moves/moves-based-on-type-cyclic-types-issue-4821.stderr
index a315bbaab33c0..db4382b58fcb2 100644
--- a/src/test/ui/moves/moves-based-on-type-cyclic-types-issue-4821.stderr
+++ b/src/test/ui/moves/moves-based-on-type-cyclic-types-issue-4821.stderr
@@ -8,7 +8,7 @@ LL |     consume(node) + r
    |             ^^^^ value used here after partial move
    |
    = note: partial move occurs because value has type `Box<List>`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `node.next.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         Some(ref right) => consume(right),
    |              +++
diff --git a/src/test/ui/moves/moves-based-on-type-distribute-copy-over-paren.stderr b/src/test/ui/moves/moves-based-on-type-distribute-copy-over-paren.stderr
index ee7971691a4a1..0930df148059d 100644
--- a/src/test/ui/moves/moves-based-on-type-distribute-copy-over-paren.stderr
+++ b/src/test/ui/moves/moves-based-on-type-distribute-copy-over-paren.stderr
@@ -9,6 +9,11 @@ LL |     let _y = Foo { f:x };
 LL |
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = Foo { f:x.clone() };
+   |                       ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-distribute-copy-over-paren.rs:21:11
@@ -21,6 +26,11 @@ LL |     let _y = Foo { f:(((x))) };
 LL |
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = Foo { f:(((x))).clone() };
+   |                             ++++++++
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/moves/moves-based-on-type-exprs.stderr b/src/test/ui/moves/moves-based-on-type-exprs.stderr
index 9bcec36740d62..78138d214f9a4 100644
--- a/src/test/ui/moves/moves-based-on-type-exprs.stderr
+++ b/src/test/ui/moves/moves-based-on-type-exprs.stderr
@@ -7,6 +7,11 @@ LL |     let _y = Foo { f:x };
    |                      - value moved here
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = Foo { f:x.clone() };
+   |                       ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:18:11
@@ -17,6 +22,11 @@ LL |     let _y = (x, 3);
    |               - value moved here
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = (x.clone(), 3);
+   |                ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:35:11
@@ -29,6 +39,11 @@ LL |         x
 ...
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         x.clone()
+   |          ++++++++
 
 error[E0382]: borrow of moved value: `y`
   --> $DIR/moves-based-on-type-exprs.rs:36:11
@@ -41,6 +56,11 @@ LL |         y
 ...
 LL |     touch(&y);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         y.clone()
+   |          ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:46:11
@@ -53,6 +73,11 @@ LL |         true => x,
 ...
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         true => x.clone(),
+   |                  ++++++++
 
 error[E0382]: borrow of moved value: `y`
   --> $DIR/moves-based-on-type-exprs.rs:47:11
@@ -65,6 +90,11 @@ LL |         false => y
 ...
 LL |     touch(&y);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         false => y.clone()
+   |                   ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:58:11
@@ -77,6 +107,18 @@ LL |         _ if guard(x) => 10,
 ...
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+note: consider changing this parameter type in `guard` to borrow instead if ownering the value isn't necessary
+  --> $DIR/moves-based-on-type-exprs.rs:6:14
+   |
+LL | fn guard(_s: String) -> bool {panic!()}
+   |    -----     ^^^^^^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         _ if guard(x.clone()) => 10,
+   |                     ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:65:11
@@ -87,6 +129,11 @@ LL |     let _y = [x];
    |               - value moved here
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = [x.clone()];
+   |                ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:71:11
@@ -97,6 +144,11 @@ LL |     let _y = vec![x];
    |                   - value moved here
 LL |     touch(&x);
    |           ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = vec![x.clone()];
+   |                    ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:77:11
@@ -113,6 +165,10 @@ note: this function takes ownership of the receiver `self`, which moves `x`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = x.clone().into_iter().next().unwrap();
+   |               ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/moves-based-on-type-exprs.rs:83:11
@@ -129,6 +185,10 @@ note: this function takes ownership of the receiver `self`, which moves `x`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = [x.clone().into_iter().next().unwrap(); 1];
+   |                ++++++++
 
 error: aborting due to 11 previous errors
 
diff --git a/src/test/ui/moves/moves-based-on-type-match-bindings.stderr b/src/test/ui/moves/moves-based-on-type-match-bindings.stderr
index ad1a2db8b52ba..225935532ead7 100644
--- a/src/test/ui/moves/moves-based-on-type-match-bindings.stderr
+++ b/src/test/ui/moves/moves-based-on-type-match-bindings.stderr
@@ -8,6 +8,10 @@ LL |     touch(&x);
    |           ^^ value borrowed here after partial move
    |
    = note: partial move occurs because `x.f` has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         Foo {ref f} => {}
+   |              +++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/moves-based-on-type-tuple.stderr b/src/test/ui/moves/moves-based-on-type-tuple.stderr
index eef8ce61fa9d8..0bcce30126306 100644
--- a/src/test/ui/moves/moves-based-on-type-tuple.stderr
+++ b/src/test/ui/moves/moves-based-on-type-tuple.stderr
@@ -8,6 +8,11 @@ LL |     Box::new((x, x))
    |               -  ^ value used here after move
    |               |
    |               value moved here
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     Box::new((x.clone(), x))
+   |                ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/use_of_moved_value_clone_suggestions.stderr b/src/test/ui/moves/use_of_moved_value_clone_suggestions.stderr
index c25981e6f8063..22e7951dbe367 100644
--- a/src/test/ui/moves/use_of_moved_value_clone_suggestions.stderr
+++ b/src/test/ui/moves/use_of_moved_value_clone_suggestions.stderr
@@ -7,6 +7,11 @@ LL |     (t, t)
    |      -  ^ value used here after move
    |      |
    |      value moved here
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     (t.clone(), t)
+   |       ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/closure-access-spans.stderr b/src/test/ui/nll/closure-access-spans.stderr
index e9d7ca953d65b..0a09353b8ec0a 100644
--- a/src/test/ui/nll/closure-access-spans.stderr
+++ b/src/test/ui/nll/closure-access-spans.stderr
@@ -67,6 +67,11 @@ LL |     || x.len();
    |     ^^ - borrow occurs due to use in closure
    |     |
    |     value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let r = x.clone();
+   |              ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/closure-access-spans.rs:40:5
@@ -79,6 +84,11 @@ LL |     || x = String::new();
    |     ^^ - borrow occurs due to use in closure
    |     |
    |     value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let r = x.clone();
+   |              ++++++++
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/closure-access-spans.rs:45:5
diff --git a/src/test/ui/nll/issue-21232-partial-init-and-use.stderr b/src/test/ui/nll/issue-21232-partial-init-and-use.stderr
index 947c9e29b4508..97ed414b1eceb 100644
--- a/src/test/ui/nll/issue-21232-partial-init-and-use.stderr
+++ b/src/test/ui/nll/issue-21232-partial-init-and-use.stderr
@@ -37,6 +37,11 @@ LL |     let mut t: T = (0, Box::new(0)); drop(t);
    |         move occurs because `t` has type `(u32, Box<u32>)`, which does not implement the `Copy` trait
 LL |     t.0 = 10; t.1 = Box::new(20);
    |     ^^^^^^^^ value partially assigned here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let mut t: T = (0, Box::new(0)); drop(t.clone());
+   |                                            ++++++++
 
 error[E0381]: partially assigned binding `s` isn't fully initialized
   --> $DIR/issue-21232-partial-init-and-use.rs:123:5
@@ -77,6 +82,11 @@ LL |     let mut t: T = (0, Box::new(0)); drop(t);
    |         move occurs because `t` has type `(u32, Box<u32>)`, which does not implement the `Copy` trait
 LL |     t.0 = 10;
    |     ^^^^^^^^ value partially assigned here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let mut t: T = (0, Box::new(0)); drop(t.clone());
+   |                                            ++++++++
 
 error[E0381]: partially assigned binding `s` isn't fully initialized
   --> $DIR/issue-21232-partial-init-and-use.rs:149:5
@@ -208,6 +218,11 @@ LL |         c2 => {
    |         -- value moved here
 LL |             c.0 = 2;
    |             ^^^^^^^ value partially assigned here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref c2 => {
+   |         +++
 
 error[E0382]: assign to part of moved value: `c`
   --> $DIR/issue-21232-partial-init-and-use.rs:255:13
@@ -219,6 +234,11 @@ LL |         c2 => {
    |         -- value moved here
 LL |             (c.1).0 = 2;
    |             ^^^^^^^^^^^ value partially assigned here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref c2 => {
+   |         +++
 
 error[E0382]: assign to part of moved value: `c.1`
   --> $DIR/issue-21232-partial-init-and-use.rs:263:13
@@ -229,6 +249,10 @@ LL |             ((c.1).1).0 = 3;
    |             ^^^^^^^^^^^^^^^ value partially assigned here after move
    |
    = note: move occurs because `c.1` has type `(i32, (i32, String))`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref c2 => {
+   |         +++
 
 error: aborting due to 23 previous errors
 
diff --git a/src/test/ui/nll/issue-51512.stderr b/src/test/ui/nll/issue-51512.stderr
index e591ca08290eb..072e96788b17e 100644
--- a/src/test/ui/nll/issue-51512.stderr
+++ b/src/test/ui/nll/issue-51512.stderr
@@ -7,6 +7,11 @@ LL |     let r = range;
    |             ----- value moved here
 LL |     let x = range.start;
    |             ^^^^^^^^^^^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let r = range.clone();
+   |                  ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/issue-53807.stderr b/src/test/ui/nll/issue-53807.stderr
index 574a114340f03..d8f58b591311d 100644
--- a/src/test/ui/nll/issue-53807.stderr
+++ b/src/test/ui/nll/issue-53807.stderr
@@ -5,7 +5,7 @@ LL |         if let Some(thing) = maybe {
    |                     ^^^^^ value moved here, in previous iteration of loop
    |
    = note: move occurs because value has type `Vec<bool>`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `maybe.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         if let Some(ref thing) = maybe {
    |                     +++
diff --git a/src/test/ui/nll/match-cfg-fake-edges.stderr b/src/test/ui/nll/match-cfg-fake-edges.stderr
index 2d48a914218fd..f72ed3af71823 100644
--- a/src/test/ui/nll/match-cfg-fake-edges.stderr
+++ b/src/test/ui/nll/match-cfg-fake-edges.stderr
@@ -26,6 +26,11 @@ LL |         false if { drop(x); true } => 1,
 LL |         true => {
 LL |             x;
    |             ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         false if { drop(x.clone()); true } => 1,
+   |                          ++++++++
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/nll/ref-suggestion.stderr b/src/test/ui/nll/ref-suggestion.stderr
index a973c583a9d66..b1f5117cb0243 100644
--- a/src/test/ui/nll/ref-suggestion.stderr
+++ b/src/test/ui/nll/ref-suggestion.stderr
@@ -7,6 +7,11 @@ LL |     let y = x;
    |             - value moved here
 LL |     x;
    |     ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let y = x.clone();
+   |              ++++++++
 
 error[E0382]: use of moved value: `x`
   --> $DIR/ref-suggestion.rs:8:5
@@ -17,6 +22,11 @@ LL |     let mut y = x;
    |                 - value moved here
 LL |     x;
    |     ^ value used here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let mut y = x.clone();
+   |                  ++++++++
 
 error[E0382]: use of partially moved value: `x`
   --> $DIR/ref-suggestion.rs:16:5
@@ -28,7 +38,7 @@ LL |     x;
    |     ^ value used here after partial move
    |
    = note: partial move occurs because value has type `Vec<i32>`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `x.0.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         (Some(ref y), ()) => {},
    |               +++
diff --git a/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr b/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
index fad84dda0e192..e79e4e7dfa336 100644
--- a/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
+++ b/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
@@ -45,7 +45,7 @@ LL |         Some(ref _y @ _z) => {}
    |              value borrowed here after move
    |
    = note: move occurs because value has type `X`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `x.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         Some(ref _y @ ref _z) => {}
    |                       +++
@@ -59,7 +59,7 @@ LL |         Some(ref mut _y @ _z) => {}
    |              value borrowed here after move
    |
    = note: move occurs because value has type `X`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving `x.0`
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         Some(ref mut _y @ ref _z) => {}
    |                           +++
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
index a227cc583d68d..077583dd2527c 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
@@ -6,6 +6,11 @@ LL |     let a @ b = U;
    |         |   |
    |         |   value moved here
    |         value used here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ ref b = U;
+   |             +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:13:9
@@ -16,6 +21,10 @@ LL |     let a @ (b, c) = (U, U);
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (b, ref c) = (U, U);
+   |                 +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:15:9
@@ -26,6 +35,10 @@ LL |     let a @ (b, c) = (u(), u());
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (b, ref c) = (u(), u());
+   |                 +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-move-and-move.rs:18:16
@@ -36,6 +49,11 @@ LL |         a @ Ok(b) | a @ Err(b) => {}
    |         -      ^ value used here after move
    |         |
    |         value moved here
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Ok(b) | a @ Err(b) => {}
+   |         +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-move-and-move.rs:18:29
@@ -46,6 +64,11 @@ LL |         a @ Ok(b) | a @ Err(b) => {}
    |                     -       ^ value used here after move
    |                     |
    |                     value moved here
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         a @ Ok(b) | ref a @ Err(b) => {}
+   |                     +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:25:9
@@ -56,6 +79,10 @@ LL |         xs @ [a, .., b] => {}
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         xs @ [a, .., ref b] => {}
+   |                      +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:29:9
@@ -66,6 +93,10 @@ LL |         xs @ [_, ys @ .., _] => {}
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         xs @ [_, ref ys @ .., _] => {}
+   |                  +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-move-and-move.rs:22:12
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
index 002c7609f6109..f27df32ccfa5c 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-at-and-box.stderr
@@ -79,6 +79,10 @@ LL |     let ref a @ box b = Box::new(NC);
    |         value borrowed here after move
    |
    = note: move occurs because value has type `NC`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ box ref b = Box::new(NC);
+   |                     +++
 
 error[E0502]: cannot borrow value as immutable because it is also borrowed as mutable
   --> $DIR/borrowck-pat-at-and-box.rs:38:9
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr
index a9e66de084242..a41ebf1931f94 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr
@@ -267,6 +267,10 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (U, U);
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (mut b @ ref mut c, ref d @ ref e) = (U, U);
+   |                                 +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:33:9
@@ -277,6 +281,10 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (u(), u());
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (mut b @ ref mut c, ref d @ ref e) = (u(), u());
+   |                                 +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:47:38
@@ -285,6 +293,11 @@ LL |     match Some((U, U)) {
    |           ------------ move occurs because value has type `Option<(U, U)>`, which does not implement the `Copy` trait
 LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |         - value moved here           ^ value used here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some((mut b @ ref mut c, d @ ref e)) => {}
+   |         +++
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:55:30
@@ -305,6 +318,11 @@ LL |         a @ Some(ref b) => {}
    |         -        ^^^^^ value borrowed here after move
    |         |
    |         value moved here
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some(ref b) => {}
+   |         +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:67:38
@@ -313,6 +331,11 @@ LL |     match Some((u(), u())) {
    |           ---------------- move occurs because value has type `Option<(U, U)>`, which does not implement the `Copy` trait
 LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |         - value moved here           ^ value used here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some((mut b @ ref mut c, d @ ref e)) => {}
+   |         +++
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:75:30
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr
index b2f22fe86388e..770bb89530cca 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref.stderr
@@ -242,6 +242,10 @@ LL |     let ref mut a @ [b, mut c] = [U, U];
    |         value borrowed here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref mut a @ [b, ref mut c] = [U, U];
+   |                         +++
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref.rs:33:9
@@ -251,6 +255,11 @@ LL |     let ref a @ b = u();
    |         |       |
    |         |       value moved here
    |         value borrowed here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ ref b = u();
+   |                 +++
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref.rs:36:18
@@ -261,6 +270,10 @@ LL |     let ref a @ (ref b @ mut c, ref d @ e) = (u(), u());
    |                  value borrowed here after move
    |
    = note: move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ (ref b @ ref mut c, ref d @ e) = (u(), u());
+   |                          +++
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref.rs:36:33
@@ -271,6 +284,10 @@ LL |     let ref a @ (ref b @ mut c, ref d @ e) = (u(), u());
    |                                 value borrowed here after move
    |
    = note: move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ (ref b @ mut c, ref d @ ref e) = (u(), u());
+   |                                         +++
 
 error[E0382]: borrow of partially moved value
   --> $DIR/borrowck-pat-by-move-and-ref.rs:42:9
@@ -281,6 +298,10 @@ LL |     let ref mut a @ [b, mut c] = [u(), u()];
    |         value borrowed here after partial move
    |
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref mut a @ [b, ref mut c] = [u(), u()];
+   |                         +++
 
 error[E0382]: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref.rs:69:23
@@ -291,7 +312,7 @@ LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |                       value borrowed here after move
    |
    = note: move occurs because value has type `U`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving the value
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         ref a @ Some((ref b @ ref mut c, ref d @ e)) => {}
    |                               +++
@@ -305,7 +326,7 @@ LL |         ref a @ Some((ref b @ mut c, ref d @ e)) => {}
    |                                      value borrowed here after move
    |
    = note: move occurs because value has type `U`, which does not implement the `Copy` trait
-help: borrow this field in the pattern to avoid moving the value
+help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         ref a @ Some((ref b @ mut c, ref d @ ref e)) => {}
    |                                              +++
diff --git a/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr b/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr
index cd3234952fa54..4ea3dfefb77a3 100644
--- a/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr
+++ b/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr
@@ -7,6 +7,10 @@ LL |     let a @ NC(b, c @ NC(d, e)) = NC(C, NC(C, C));
    |         value used here after partial move
    |
    = note: partial move occurs because value has type `NC<C, C>`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ NC(b, ref c @ NC(d, e)) = NC(C, NC(C, C));
+   |                   +++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr b/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
index 840a513d6c67d..43e4b6990d2a2 100644
--- a/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
+++ b/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
@@ -52,6 +52,11 @@ LL |     let ref mut a @ b = NotCopy;
    |         |           |
    |         |           value moved here
    |         value borrowed here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref mut a @ ref b = NotCopy;
+   |                     +++
 
 error: aborting due to 6 previous errors
 
diff --git a/src/test/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr b/src/test/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr
index bac2db6ce825c..bb7b818368b78 100644
--- a/src/test/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr
+++ b/src/test/ui/pattern/move-ref-patterns/borrowck-move-ref-pattern.stderr
@@ -129,6 +129,10 @@ LL |     drop(tup.1);
    |          ^^^^^ value used here after move
    |
    = note: move occurs because `tup.1` has type `U`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let (ref _x0, ref _x1, ref _x2, ..) = tup;
+   |                   +++
 
 error[E0382]: borrow of moved value: `tup.1`
   --> $DIR/borrowck-move-ref-pattern.rs:29:20
diff --git a/src/test/ui/rfc-2361-dbg-macro/dbg-macro-move-semantics.stderr b/src/test/ui/rfc-2361-dbg-macro/dbg-macro-move-semantics.stderr
index 5611b5f4ece5f..06699b947be40 100644
--- a/src/test/ui/rfc-2361-dbg-macro/dbg-macro-move-semantics.stderr
+++ b/src/test/ui/rfc-2361-dbg-macro/dbg-macro-move-semantics.stderr
@@ -7,6 +7,12 @@ LL |     let _ = dbg!(a);
    |             ------- value moved here
 LL |     let _ = dbg!(a);
    |                  ^ value used here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+  --> $SRC_DIR/std/src/macros.rs:LL:COL
+   |
+LL |             ref tmp => {
+   |             +++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/suggestions/borrow-for-loop-head.stderr b/src/test/ui/suggestions/borrow-for-loop-head.stderr
index 1059e3d1525aa..7cd411dde6c21 100644
--- a/src/test/ui/suggestions/borrow-for-loop-head.stderr
+++ b/src/test/ui/suggestions/borrow-for-loop-head.stderr
@@ -12,6 +12,7 @@ error[E0382]: use of moved value: `a`
 LL |     let a = vec![1, 2, 3];
    |         - move occurs because `a` has type `Vec<i32>`, which does not implement the `Copy` trait
 LL |     for i in &a {
+   |     ----------- inside of this loop
 LL |         for j in a {
    |                  ^ `a` moved due to this implicit call to `.into_iter()`, in previous iteration of loop
    |
@@ -20,6 +21,10 @@ note: this function takes ownership of the receiver `self`, which moves `a`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         for j in a.clone() {
+   |                   ++++++++
 help: consider iterating over a slice of the `Vec<i32>`'s content to avoid moving into the `for` loop
    |
 LL |         for j in &a {
diff --git a/src/test/ui/try-block/try-block-maybe-bad-lifetime.stderr b/src/test/ui/try-block/try-block-maybe-bad-lifetime.stderr
index c9f2a3ed9f4bf..f738b03eed6b8 100644
--- a/src/test/ui/try-block/try-block-maybe-bad-lifetime.stderr
+++ b/src/test/ui/try-block/try-block-maybe-bad-lifetime.stderr
@@ -23,6 +23,10 @@ LL |         println!("{}", x);
    |                        ^ value borrowed here after move
    |
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |             ::std::mem::drop(x.clone());
+   |                               ++++++++
 
 error[E0506]: cannot assign to `i` because it is borrowed
   --> $DIR/try-block-maybe-bad-lifetime.rs:40:9
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr
index ab6f06518467c..3175d2942d5a7 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr
@@ -16,6 +16,10 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     tick();
    |     ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     tick.clone()();
+   |         ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr
index 8d70a2b17602b..ffeafb10fda2c 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr
@@ -16,6 +16,10 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     tick();
    |     ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     tick.clone()();
+   |         ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/union/union-move.mirunsafeck.stderr b/src/test/ui/union/union-move.mirunsafeck.stderr
index 53050cf539eaf..91f2eaad944eb 100644
--- a/src/test/ui/union/union-move.mirunsafeck.stderr
+++ b/src/test/ui/union/union-move.mirunsafeck.stderr
@@ -8,6 +8,14 @@ LL |         move_out(x.f1_nocopy);
    |                  ----------- value moved here
 LL |         move_out(x.f2_nocopy);
    |                  ^^^^^^^^^^^ value used here after move
+   |
+note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+  --> $DIR/union-move.rs:10:19
+   |
+LL | fn move_out<T>(x: T) {}
+   |    --------       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error[E0382]: use of moved value: `x`
   --> $DIR/union-move.rs:45:18
@@ -19,6 +27,14 @@ LL |         move_out(x.f2_nocopy);
    |                  ----------- value moved here
 LL |         move_out(x.f3_copy);
    |                  ^^^^^^^^^ value used here after move
+   |
+note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+  --> $DIR/union-move.rs:10:19
+   |
+LL | fn move_out<T>(x: T) {}
+   |    --------       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error[E0509]: cannot move out of type `U2`, which implements the `Drop` trait
   --> $DIR/union-move.rs:52:18
diff --git a/src/test/ui/union/union-move.thirunsafeck.stderr b/src/test/ui/union/union-move.thirunsafeck.stderr
index 53050cf539eaf..91f2eaad944eb 100644
--- a/src/test/ui/union/union-move.thirunsafeck.stderr
+++ b/src/test/ui/union/union-move.thirunsafeck.stderr
@@ -8,6 +8,14 @@ LL |         move_out(x.f1_nocopy);
    |                  ----------- value moved here
 LL |         move_out(x.f2_nocopy);
    |                  ^^^^^^^^^^^ value used here after move
+   |
+note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+  --> $DIR/union-move.rs:10:19
+   |
+LL | fn move_out<T>(x: T) {}
+   |    --------       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error[E0382]: use of moved value: `x`
   --> $DIR/union-move.rs:45:18
@@ -19,6 +27,14 @@ LL |         move_out(x.f2_nocopy);
    |                  ----------- value moved here
 LL |         move_out(x.f3_copy);
    |                  ^^^^^^^^^ value used here after move
+   |
+note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+  --> $DIR/union-move.rs:10:19
+   |
+LL | fn move_out<T>(x: T) {}
+   |    --------       ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error[E0509]: cannot move out of type `U2`, which implements the `Drop` trait
   --> $DIR/union-move.rs:52:18
diff --git a/src/test/ui/unop-move-semantics.stderr b/src/test/ui/unop-move-semantics.stderr
index 65d866c716e0e..d52a92b8888e8 100644
--- a/src/test/ui/unop-move-semantics.stderr
+++ b/src/test/ui/unop-move-semantics.stderr
@@ -14,6 +14,10 @@ note: calling this operator moves the left-hand side
    |
 LL |     fn not(self) -> Self::Output;
    |            ^^^^
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     !x.clone();
+   |       ++++++++
 help: consider further restricting this bound
    |
 LL | fn move_then_borrow<T: Not<Output=T> + Clone + Copy>(x: T) {
diff --git a/src/test/ui/unsized-locals/borrow-after-move.stderr b/src/test/ui/unsized-locals/borrow-after-move.stderr
index 28ae1c0688c8e..e6964a1984238 100644
--- a/src/test/ui/unsized-locals/borrow-after-move.stderr
+++ b/src/test/ui/unsized-locals/borrow-after-move.stderr
@@ -28,6 +28,14 @@ LL |         drop_unsized(y);
 ...
 LL |         println!("{}", &y);
    |                        ^^ value borrowed here after move
+   |
+note: consider changing this parameter type in `drop_unsized` to borrow instead if ownering the value isn't necessary
+  --> $DIR/borrow-after-move.rs:14:31
+   |
+LL | fn drop_unsized<T: ?Sized>(_: T) {}
+   |    ------------               ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error[E0382]: borrow of moved value: `x`
   --> $DIR/borrow-after-move.rs:31:24
@@ -66,6 +74,11 @@ LL |         x.foo();
    |         - value moved here
 LL |         println!("{}", &x);
    |                        ^^ value borrowed here after move
+   |
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |         x.clone().foo();
+   |          ++++++++
 
 error: aborting due to 5 previous errors; 1 warning emitted
 
diff --git a/src/test/ui/unsized-locals/double-move.stderr b/src/test/ui/unsized-locals/double-move.stderr
index dfae6cc75d9c6..7d7586b0a0bc0 100644
--- a/src/test/ui/unsized-locals/double-move.stderr
+++ b/src/test/ui/unsized-locals/double-move.stderr
@@ -16,6 +16,14 @@ LL |         drop_unsized(y);
    |                      - value moved here
 LL |         drop_unsized(y);
    |                      ^ value used here after move
+   |
+note: consider changing this parameter type in `drop_unsized` to borrow instead if ownering the value isn't necessary
+  --> $DIR/double-move.rs:14:31
+   |
+LL | fn drop_unsized<T: ?Sized>(_: T) {}
+   |    ------------               ^ this type parameter takes ownership of the value
+   |    |
+   |    in this function
 
 error[E0382]: use of moved value: `x`
   --> $DIR/double-move.rs:27:22
diff --git a/src/test/ui/use/use-after-move-based-on-type.stderr b/src/test/ui/use/use-after-move-based-on-type.stderr
index 445f14d65e3ce..7b4d2454994d7 100644
--- a/src/test/ui/use/use-after-move-based-on-type.stderr
+++ b/src/test/ui/use/use-after-move-based-on-type.stderr
@@ -9,6 +9,10 @@ LL |     println!("{}", x);
    |                    ^ value borrowed here after move
    |
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider cloning the value if the performance cost is acceptable
+   |
+LL |     let _y = x.clone();
+   |               ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
index 26804216d9da7..a671434a30394 100644
--- a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
+++ b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
@@ -9,6 +9,14 @@ LL |     l.push(n);
 LL |
 LL |     let x = n.to_string();
    |             ^^^^^^^^^^^^^ value borrowed here after move
+   |
+note: consider changing this parameter type in `push` to borrow instead if ownering the value isn't necessary
+  --> $DIR/use-after-move-implicity-coerced-object.rs:17:27
+   |
+LL |     fn push(&mut self, n: Box<dyn ToString + 'static>) {
+   |        ----               ^^^^^^^^^^^^^^^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |        |
+   |        in this method
 
 error: aborting due to previous error
 

From 4a51f37bcb58b37afb8ea0ac4b8696714787a305 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 09:19:03 -0700
Subject: [PATCH 02/15] Do not suggest `ref` multiple times for the same
 binding

---
 .../rustc_borrowck/src/diagnostics/conflict_errors.rs     | 4 +++-
 ...fter-at-or-patterns-slice-patterns-box-patterns.stderr | 8 --------
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 9b6836039a138..8a4b0ebe737e4 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -171,6 +171,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
             let mut is_loop_move = false;
             let mut in_pattern = false;
+            let mut seen_spans = FxHashSet::default();
 
             for move_site in &move_site_vec {
                 let move_out = self.move_data.moves[(*move_site).moi];
@@ -320,7 +321,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             self.suggest_cloning(&mut err, ty, move_span);
                         }
                     }
-                    if let Some(pat) = finder.pat {
+                    if let Some(pat) = finder.pat && !seen_spans.contains(&pat.span) {
                         in_pattern = true;
                         err.span_suggestion_verbose(
                             pat.span.shrink_to_lo(),
@@ -328,6 +329,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             "ref ".to_string(),
                             Applicability::MachineApplicable,
                         );
+                        seen_spans.insert(pat.span);
                     }
                 }
 
diff --git a/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr b/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
index f58672f0666be..d06b3bc1c3e60 100644
--- a/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
+++ b/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
@@ -88,10 +88,6 @@ help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         ref foo @ Some(Test::Foo | Test::Bar) => (),
    |         +++
-help: borrow this binding in the pattern to avoid moving the value
-   |
-LL |         ref foo @ Some(Test::Foo | Test::Bar) => (),
-   |         +++
 
 error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:86:5
@@ -148,10 +144,6 @@ help: borrow this binding in the pattern to avoid moving the value
    |
 LL |         ref a @ [.., Some(Test::Foo | Test::Bar)] => (),
    |         +++
-help: borrow this binding in the pattern to avoid moving the value
-   |
-LL |         ref a @ [.., Some(Test::Foo | Test::Bar)] => (),
-   |         +++
 
 error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable
   --> $DIR/bindings-after-at-or-patterns-slice-patterns-box-patterns.rs:144:5

From 4f2f59ba6f3f6960097bf29363de5211cfa6ba7a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 09:19:23 -0700
Subject: [PATCH 03/15] Fix clippy code

---
 .../clippy/clippy_lints/src/suspicious_operation_groupings.rs   | 2 +-
 src/tools/clippy/clippy_utils/src/ast_utils.rs                  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs b/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs
index 78e83880e1a61..e111c7d229151 100644
--- a/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs
+++ b/src/tools/clippy/clippy_lints/src/suspicious_operation_groupings.rs
@@ -582,7 +582,7 @@ fn ident_difference_expr_with_base_location(
         | (Block(_, _), Block(_, _))
         | (Closure(_), Closure(_))
         | (Match(_, _), Match(_, _))
-        | (Loop(_, _), Loop(_, _))
+        | (Loop(_, _, _), Loop(_, _, _))
         | (ForLoop(_, _, _, _), ForLoop(_, _, _, _))
         | (While(_, _, _), While(_, _, _))
         | (If(_, _, _), If(_, _, _))
diff --git a/src/tools/clippy/clippy_utils/src/ast_utils.rs b/src/tools/clippy/clippy_utils/src/ast_utils.rs
index 5c595f74eff26..6bcf0bbd7eb75 100644
--- a/src/tools/clippy/clippy_utils/src/ast_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/ast_utils.rs
@@ -171,7 +171,7 @@ pub fn eq_expr(l: &Expr, r: &Expr) -> bool {
         (ForLoop(lp, li, lt, ll), ForLoop(rp, ri, rt, rl)) => {
             eq_label(ll, rl) && eq_pat(lp, rp) && eq_expr(li, ri) && eq_block(lt, rt)
         },
-        (Loop(lt, ll), Loop(rt, rl)) => eq_label(ll, rl) && eq_block(lt, rt),
+        (Loop(lt, ll, _), Loop(rt, rl, _)) => eq_label(ll, rl) && eq_block(lt, rt),
         (Block(lb, ll), Block(rb, rl)) => eq_label(ll, rl) && eq_block(lb, rb),
         (TryBlock(l), TryBlock(r)) => eq_block(l, r),
         (Yield(l), Yield(r)) | (Ret(l), Ret(r)) => eq_expr_opt(l, r),

From 14a3d572e62dd1b7a69495ab5b4a04798b2bdc51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 11:06:25 -0700
Subject: [PATCH 04/15] Use `type_implements_trait`

---
 .../src/diagnostics/conflict_errors.rs        | 25 ++++---------------
 1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 8a4b0ebe737e4..c445ad593ca45 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -715,28 +715,13 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
     fn suggest_cloning(&self, err: &mut Diagnostic, ty: Ty<'tcx>, span: Span) {
         let tcx = self.infcx.tcx;
-
         // Try to find predicates on *generic params* that would allow copying `ty`
         let infcx = tcx.infer_ctxt().build();
-        let mut fulfill_cx = <dyn rustc_infer::traits::TraitEngine<'_>>::new(infcx.tcx);
-
-        let clone_did = infcx.tcx.lang_items().clone_trait().unwrap();
-        let cause = ObligationCause::new(
-            span,
-            self.mir_hir_id(),
-            rustc_infer::traits::ObligationCauseCode::MiscObligation,
-        );
-        fulfill_cx.register_bound(
-            &infcx,
-            self.param_env,
-            // Erase any region vids from the type, which may not be resolved
-            infcx.tcx.erase_regions(ty),
-            clone_did,
-            cause,
-        );
-        // Select all, including ambiguous predicates
-        let errors = fulfill_cx.select_all_or_error(&infcx);
-        if errors.is_empty() {
+        let clone_did = tcx.lang_items().clone_trait().unwrap();
+        let params = ty::List::empty();
+        let ty = tcx.erase_regions(ty);
+        let env = self.param_env;
+        if infcx.type_implements_trait(clone_did, ty, params, env).must_apply_modulo_regions() {
             err.span_suggestion_verbose(
                 span.shrink_to_hi(),
                 "consider cloning the value if the performance cost is acceptable",

From 42d7174bbc6f89f15a233d663f212e5e731f4722 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 11:52:26 -0700
Subject: [PATCH 05/15] Extract suggestion logic to its own method

---
 .../src/diagnostics/conflict_errors.rs        | 296 +++++++++---------
 1 file changed, 156 insertions(+), 140 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index c445ad593ca45..3b888940c2d85 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -192,146 +192,13 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     is_loop_move = true;
                 }
 
-                struct ExpressionFinder<'hir> {
-                    expr_span: Span,
-                    expr: Option<&'hir hir::Expr<'hir>>,
-                    pat: Option<&'hir hir::Pat<'hir>>,
-                }
-                impl<'hir> Visitor<'hir> for ExpressionFinder<'hir> {
-                    fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
-                        if e.span == self.expr_span {
-                            self.expr = Some(e);
-                        }
-                        hir::intravisit::walk_expr(self, e);
-                    }
-                    fn visit_pat(&mut self, p: &'hir hir::Pat<'hir>) {
-                        if p.span == self.expr_span {
-                            self.pat = Some(p);
-                        }
-                        if let hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, i, _) = p.kind
-                            && i.span == self.expr_span
-                        {
-                            self.pat = Some(p);
-                        }
-                        hir::intravisit::walk_pat(self, p);
-                    }
-                }
-
-                let hir = self.infcx.tcx.hir();
-                if let Some(hir::Node::Item(hir::Item {
-                    kind: hir::ItemKind::Fn(_, _, body_id),
-                    ..
-                })) = hir.find(hir.local_def_id_to_hir_id(self.mir_def_id()))
-                    && let Some(hir::Node::Expr(expr)) = hir.find(body_id.hir_id)
-                {
-                    let place = &self.move_data.move_paths[mpi].place;
-                    let span = place.as_local()
-                        .map(|local| self.body.local_decls[local].source_info.span);
-                    let mut finder = ExpressionFinder {
-                        expr_span: move_span,
-                        expr: None,
-                        pat: None,
-                    };
-                    finder.visit_expr(expr);
-                    if let Some(span) = span && let Some(expr) = finder.expr {
-                        for (_, expr) in hir.parent_iter(expr.hir_id) {
-                            if let hir::Node::Expr(expr) = expr {
-                                if expr.span.contains(span) {
-                                    // If the let binding occurs within the same loop, then that
-                                    // loop isn't relevant, like in the following, the outermost `loop`
-                                    // doesn't play into `x` being moved.
-                                    // ```
-                                    // loop {
-                                    //     let x = String::new();
-                                    //     loop {
-                                    //         foo(x);
-                                    //     }
-                                    // }
-                                    // ```
-                                    break;
-                                }
-                                if let hir::ExprKind::Loop(.., loop_span) = expr.kind {
-                                    err.span_label(loop_span, "inside of this loop");
-                                }
-                            }
-                        }
-                        let typeck = self.infcx.tcx.typeck(self.mir_def_id());
-                        let hir_id = hir.get_parent_node(expr.hir_id);
-                        if let Some(parent) = hir.find(hir_id) {
-                            if let hir::Node::Expr(parent_expr) = parent
-                                && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
-                                && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
-                                && let Some(def_id) = def_id.as_local()
-                                && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
-                                && let Some(fn_sig) = node.fn_sig()
-                                && let Some(ident) = node.ident()
-                                && let Some(pos) = args.iter()
-                                    .position(|arg| arg.hir_id == expr.hir_id)
-                                && let Some(arg) = fn_sig.decl.inputs.get(pos + 1)
-                            {
-                                let mut span: MultiSpan = arg.span.into();
-                                span.push_span_label(
-                                    arg.span,
-                                    "this type parameter takes ownership of the value".to_string(),
-                                );
-                                span.push_span_label(
-                                    ident.span,
-                                    "in this method".to_string(),
-                                );
-                                err.span_note(
-                                    span,
-                                    format!(
-                                        "consider changing this parameter type in `{}` to borrow \
-                                         instead if ownering the value isn't necessary",
-                                        ident,
-                                    ),
-                                );
-                            }
-                            if let hir::Node::Expr(parent_expr) = parent
-                                && let hir::ExprKind::Call(call, args) = parent_expr.kind
-                                && let ty::FnDef(def_id, _) = typeck.node_type(call.hir_id).kind()
-                                && let Some(def_id) = def_id.as_local()
-                                && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
-                                && let Some(fn_sig) = node.fn_sig()
-                                && let Some(ident) = node.ident()
-                                && let Some(pos) = args.iter()
-                                    .position(|arg| arg.hir_id == expr.hir_id)
-                                && let Some(arg) = fn_sig.decl.inputs.get(pos)
-                            {
-                                let mut span: MultiSpan = arg.span.into();
-                                span.push_span_label(
-                                    arg.span,
-                                    "this type parameter takes ownership of the value".to_string(),
-                                );
-                                span.push_span_label(
-                                    ident.span,
-                                    "in this function".to_string(),
-                                );
-                                err.span_note(
-                                    span,
-                                    format!(
-                                        "consider changing this parameter type in `{}` to borrow \
-                                         instead if ownering the value isn't necessary",
-                                        ident,
-                                    ),
-                                );
-                            }
-                            let place = &self.move_data.move_paths[mpi].place;
-                            let ty = place.ty(self.body, self.infcx.tcx).ty;
-                            self.suggest_cloning(&mut err, ty, move_span);
-                        }
-                    }
-                    if let Some(pat) = finder.pat && !seen_spans.contains(&pat.span) {
-                        in_pattern = true;
-                        err.span_suggestion_verbose(
-                            pat.span.shrink_to_lo(),
-                            "borrow this binding in the pattern to avoid moving the value",
-                            "ref ".to_string(),
-                            Applicability::MachineApplicable,
-                        );
-                        seen_spans.insert(pat.span);
-                    }
-                }
+                self.suggest_ref_or_clone(
+                    mpi,
+                    move_span,
+                    &mut err,
+                    &mut seen_spans,
+                    &mut in_pattern,
+                );
 
                 self.explain_captures(
                     &mut err,
@@ -440,6 +307,155 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         }
     }
 
+    fn suggest_ref_or_clone(
+        &mut self,
+        mpi: MovePathIndex,
+        move_span: Span,
+        err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>,
+        seen_spans: &mut FxHashSet<Span>,
+        in_pattern: &mut bool,
+    ) {
+        struct ExpressionFinder<'hir> {
+            expr_span: Span,
+            expr: Option<&'hir hir::Expr<'hir>>,
+            pat: Option<&'hir hir::Pat<'hir>>,
+        }
+        impl<'hir> Visitor<'hir> for ExpressionFinder<'hir> {
+            fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
+                if e.span == self.expr_span {
+                    self.expr = Some(e);
+                }
+                hir::intravisit::walk_expr(self, e);
+            }
+            fn visit_pat(&mut self, p: &'hir hir::Pat<'hir>) {
+                if p.span == self.expr_span {
+                    self.pat = Some(p);
+                }
+                if let hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, i, _) = p.kind
+                    && i.span == self.expr_span
+                {
+                    self.pat = Some(p);
+                }
+                hir::intravisit::walk_pat(self, p);
+            }
+        }
+        let hir = self.infcx.tcx.hir();
+        if let Some(hir::Node::Item(hir::Item {
+            kind: hir::ItemKind::Fn(_, _, body_id),
+            ..
+        })) = hir.find(hir.local_def_id_to_hir_id(self.mir_def_id()))
+            && let Some(hir::Node::Expr(expr)) = hir.find(body_id.hir_id)
+        {
+            let place = &self.move_data.move_paths[mpi].place;
+            let span = place.as_local()
+                .map(|local| self.body.local_decls[local].source_info.span);
+            let mut finder = ExpressionFinder {
+                expr_span: move_span,
+                expr: None,
+                pat: None,
+            };
+            finder.visit_expr(expr);
+            if let Some(span) = span && let Some(expr) = finder.expr {
+                for (_, expr) in hir.parent_iter(expr.hir_id) {
+                    if let hir::Node::Expr(expr) = expr {
+                        if expr.span.contains(span) {
+                            // If the let binding occurs within the same loop, then that
+                            // loop isn't relevant, like in the following, the outermost `loop`
+                            // doesn't play into `x` being moved.
+                            // ```
+                            // loop {
+                            //     let x = String::new();
+                            //     loop {
+                            //         foo(x);
+                            //     }
+                            // }
+                            // ```
+                            break;
+                        }
+                        if let hir::ExprKind::Loop(.., loop_span) = expr.kind {
+                            err.span_label(loop_span, "inside of this loop");
+                        }
+                    }
+                }
+                let typeck = self.infcx.tcx.typeck(self.mir_def_id());
+                let hir_id = hir.get_parent_node(expr.hir_id);
+                if let Some(parent) = hir.find(hir_id) {
+                    if let hir::Node::Expr(parent_expr) = parent
+                        && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
+                        && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
+                        && let Some(def_id) = def_id.as_local()
+                        && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
+                        && let Some(fn_sig) = node.fn_sig()
+                        && let Some(ident) = node.ident()
+                        && let Some(pos) = args.iter()
+                            .position(|arg| arg.hir_id == expr.hir_id)
+                        && let Some(arg) = fn_sig.decl.inputs.get(pos + 1)
+                    {
+                        let mut span: MultiSpan = arg.span.into();
+                        span.push_span_label(
+                            arg.span,
+                            "this type parameter takes ownership of the value".to_string(),
+                        );
+                        span.push_span_label(
+                            ident.span,
+                            "in this method".to_string(),
+                        );
+                        err.span_note(
+                            span,
+                            format!(
+                                "consider changing this parameter type in `{}` to borrow instead \
+                                 if ownering the value isn't necessary",
+                                ident,
+                            ),
+                        );
+                    }
+                    if let hir::Node::Expr(parent_expr) = parent
+                        && let hir::ExprKind::Call(call, args) = parent_expr.kind
+                        && let ty::FnDef(def_id, _) = typeck.node_type(call.hir_id).kind()
+                        && let Some(def_id) = def_id.as_local()
+                        && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
+                        && let Some(fn_sig) = node.fn_sig()
+                        && let Some(ident) = node.ident()
+                        && let Some(pos) = args.iter()
+                            .position(|arg| arg.hir_id == expr.hir_id)
+                        && let Some(arg) = fn_sig.decl.inputs.get(pos)
+                    {
+                        let mut span: MultiSpan = arg.span.into();
+                        span.push_span_label(
+                            arg.span,
+                            "this type parameter takes ownership of the value".to_string(),
+                        );
+                        span.push_span_label(
+                            ident.span,
+                            "in this function".to_string(),
+                        );
+                        err.span_note(
+                            span,
+                            format!(
+                                "consider changing this parameter type in `{}` to borrow instead \
+                                 if ownering the value isn't necessary",
+                                ident,
+                            ),
+                        );
+                    }
+                    let place = &self.move_data.move_paths[mpi].place;
+                    let ty = place.ty(self.body, self.infcx.tcx).ty;
+                    self.suggest_cloning(err, ty, move_span);
+                }
+            }
+            if let Some(pat) = finder.pat && !seen_spans.contains(&pat.span) {
+                *in_pattern = true;
+                err.span_suggestion_verbose(
+                    pat.span.shrink_to_lo(),
+                    "borrow this binding in the pattern to avoid moving the value",
+                    "ref ".to_string(),
+                    Applicability::MachineApplicable,
+                );
+                seen_spans.insert(pat.span);
+            }
+        }
+    }
+
     fn report_use_of_uninitialized(
         &self,
         mpi: MovePathIndex,

From c0e481731ba72eb120a74da454bb806397ca165c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 12:26:59 -0700
Subject: [PATCH 06/15] Remove logic duplication

---
 .../src/diagnostics/conflict_errors.rs        | 51 +++++++------------
 .../borrowck-consume-unsize-vec.stderr        |  2 +-
 .../borrowck-consume-upcast-box.stderr        |  2 +-
 .../ui/borrowck/mut-borrow-in-loop-2.stderr   |  2 +-
 .../ui/liveness/liveness-move-call-arg.stderr |  2 +-
 .../liveness/liveness-use-after-send.stderr   |  2 +-
 .../borrow-closures-instead-of-move.stderr    |  6 +--
 .../ui/moves/move-guard-same-consts.stderr    |  2 +-
 src/test/ui/moves/move-in-guard-1.stderr      |  2 +-
 src/test/ui/moves/move-in-guard-2.stderr      |  2 +-
 .../ui/moves/moves-based-on-type-exprs.stderr |  2 +-
 .../ui/union/union-move.mirunsafeck.stderr    |  4 +-
 .../ui/union/union-move.thirunsafeck.stderr   |  4 +-
 .../unsized-locals/borrow-after-move.stderr   |  2 +-
 src/test/ui/unsized-locals/double-move.stderr |  2 +-
 ...after-move-implicity-coerced-object.stderr |  2 +-
 16 files changed, 37 insertions(+), 52 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 3b888940c2d85..18d8bbf90475a 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -380,61 +380,46 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 let typeck = self.infcx.tcx.typeck(self.mir_def_id());
                 let hir_id = hir.get_parent_node(expr.hir_id);
                 if let Some(parent) = hir.find(hir_id) {
-                    if let hir::Node::Expr(parent_expr) = parent
+                    let (def_id, args, offset) = if let hir::Node::Expr(parent_expr) = parent
                         && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
                         && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
-                        && let Some(def_id) = def_id.as_local()
-                        && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
-                        && let Some(fn_sig) = node.fn_sig()
-                        && let Some(ident) = node.ident()
-                        && let Some(pos) = args.iter()
-                            .position(|arg| arg.hir_id == expr.hir_id)
-                        && let Some(arg) = fn_sig.decl.inputs.get(pos + 1)
                     {
-                        let mut span: MultiSpan = arg.span.into();
-                        span.push_span_label(
-                            arg.span,
-                            "this type parameter takes ownership of the value".to_string(),
-                        );
-                        span.push_span_label(
-                            ident.span,
-                            "in this method".to_string(),
-                        );
-                        err.span_note(
-                            span,
-                            format!(
-                                "consider changing this parameter type in `{}` to borrow instead \
-                                 if ownering the value isn't necessary",
-                                ident,
-                            ),
-                        );
-                    }
-                    if let hir::Node::Expr(parent_expr) = parent
+                        (def_id.as_local(), args, 1)
+                    } else if let hir::Node::Expr(parent_expr) = parent
                         && let hir::ExprKind::Call(call, args) = parent_expr.kind
                         && let ty::FnDef(def_id, _) = typeck.node_type(call.hir_id).kind()
-                        && let Some(def_id) = def_id.as_local()
+                    {
+                        (def_id.as_local(), args, 0)
+                    } else {
+                        (None, &[][..], 0)
+                    };
+                    if let Some(def_id) = def_id
                         && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
                         && let Some(fn_sig) = node.fn_sig()
                         && let Some(ident) = node.ident()
                         && let Some(pos) = args.iter()
                             .position(|arg| arg.hir_id == expr.hir_id)
-                        && let Some(arg) = fn_sig.decl.inputs.get(pos)
+                        && let Some(arg) = fn_sig.decl.inputs.get(pos + offset)
                     {
                         let mut span: MultiSpan = arg.span.into();
                         span.push_span_label(
                             arg.span,
                             "this type parameter takes ownership of the value".to_string(),
                         );
+                        let descr = match node.fn_kind() {
+                            Some(hir::intravisit::FnKind::ItemFn(..)) | None => "function",
+                            Some(hir::intravisit::FnKind::Method(..)) => "method",
+                            Some(hir::intravisit::FnKind::Closure) => "closure",
+                        };
                         span.push_span_label(
                             ident.span,
-                            "in this function".to_string(),
+                            format!("in this {descr}"),
                         );
                         err.span_note(
                             span,
                             format!(
-                                "consider changing this parameter type in `{}` to borrow instead \
-                                 if ownering the value isn't necessary",
-                                ident,
+                                "consider changing this parameter type in {descr} `{ident}` to \
+                                 borrow instead if ownering the value isn't necessary",
                             ),
                         );
                     }
diff --git a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
index 00bb13caebdb5..cfaa8c08df836 100644
--- a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
@@ -8,7 +8,7 @@ LL |     consume(b);
 LL |     consume(b);
    |             ^ value used here after move
    |
-note: consider changing this parameter type in `consume` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `consume` to borrow instead if ownering the value isn't necessary
   --> $DIR/borrowck-consume-unsize-vec.rs:3:15
    |
 LL | fn consume(_: Box<[i32]>) {
diff --git a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
index 103f45155d7ba..c73d1df971acf 100644
--- a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
@@ -8,7 +8,7 @@ LL |     consume(b);
 LL |     consume(b);
    |             ^ value used here after move
    |
-note: consider changing this parameter type in `consume` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `consume` to borrow instead if ownering the value isn't necessary
   --> $DIR/borrowck-consume-upcast-box.rs:5:15
    |
 LL | fn consume(_: Box<dyn Foo>) {
diff --git a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
index eaf53868014fa..4f287d3a735e1 100644
--- a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
+++ b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
@@ -8,7 +8,7 @@ LL |     for _ in 0..3 {
 LL |         Other::handle(value);
    |                       ^^^^^ value moved here, in previous iteration of loop
    |
-note: consider changing this parameter type in `handle` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `handle` to borrow instead if ownering the value isn't necessary
   --> $DIR/mut-borrow-in-loop-2.rs:9:22
    |
 LL |     fn handle(value: T) -> Self;
diff --git a/src/test/ui/liveness/liveness-move-call-arg.stderr b/src/test/ui/liveness/liveness-move-call-arg.stderr
index bd45aa5345885..4a869cdce4a17 100644
--- a/src/test/ui/liveness/liveness-move-call-arg.stderr
+++ b/src/test/ui/liveness/liveness-move-call-arg.stderr
@@ -9,7 +9,7 @@ LL |     loop {
 LL |         take(x);
    |              ^ value moved here, in previous iteration of loop
    |
-note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
   --> $DIR/liveness-move-call-arg.rs:1:13
    |
 LL | fn take(_x: Box<isize>) {}
diff --git a/src/test/ui/liveness/liveness-use-after-send.stderr b/src/test/ui/liveness/liveness-use-after-send.stderr
index c407827d32050..cf4aa8fc9c414 100644
--- a/src/test/ui/liveness/liveness-use-after-send.stderr
+++ b/src/test/ui/liveness/liveness-use-after-send.stderr
@@ -8,7 +8,7 @@ LL |     send(ch, message);
 LL |     println!("{}", message);
    |                    ^^^^^^^ value borrowed here after move
    |
-note: consider changing this parameter type in `send` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `send` to borrow instead if ownering the value isn't necessary
   --> $DIR/liveness-use-after-send.rs:3:54
    |
 LL | fn send<T:Send + std::fmt::Debug>(ch: Chan<T>, data: T) {
diff --git a/src/test/ui/moves/borrow-closures-instead-of-move.stderr b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
index 11fcb1cc26381..d3f250e69b24c 100644
--- a/src/test/ui/moves/borrow-closures-instead-of-move.stderr
+++ b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
@@ -8,7 +8,7 @@ LL |     loop {
 LL |         takes_fnonce(f);
    |                      ^ value moved here, in previous iteration of loop
    |
-note: consider changing this parameter type in `takes_fnonce` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `takes_fnonce` to borrow instead if ownering the value isn't necessary
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
@@ -32,7 +32,7 @@ LL |         takes_fnonce(m);
 LL |     takes_fnonce(m);
    |                  ^ value used here after move
    |
-note: consider changing this parameter type in `takes_fnonce` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `takes_fnonce` to borrow instead if ownering the value isn't necessary
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
@@ -58,7 +58,7 @@ note: closure cannot be moved more than once as it is not `Copy` due to moving t
    |
 LL |         x += 1;
    |         ^
-note: consider changing this parameter type in `takes_fnonce` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `takes_fnonce` to borrow instead if ownering the value isn't necessary
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
diff --git a/src/test/ui/moves/move-guard-same-consts.stderr b/src/test/ui/moves/move-guard-same-consts.stderr
index 04a41b9ce2623..687e8497dc6e8 100644
--- a/src/test/ui/moves/move-guard-same-consts.stderr
+++ b/src/test/ui/moves/move-guard-same-consts.stderr
@@ -9,7 +9,7 @@ LL |         (1, 2) if take(x) => (),
 LL |         (1, 2) if take(x) => (),
    |                        ^ value used here after move
    |
-note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
   --> $DIR/move-guard-same-consts.rs:25:15
    |
 LL | fn take<T>(_: T) -> bool { false }
diff --git a/src/test/ui/moves/move-in-guard-1.stderr b/src/test/ui/moves/move-in-guard-1.stderr
index d435426f2ec97..a21dca7f16ee5 100644
--- a/src/test/ui/moves/move-in-guard-1.stderr
+++ b/src/test/ui/moves/move-in-guard-1.stderr
@@ -9,7 +9,7 @@ LL |         (1, _) if take(x) => (),
 LL |         (_, 2) if take(x) => (),
    |                        ^ value used here after move
    |
-note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
   --> $DIR/move-in-guard-1.rs:15:15
    |
 LL | fn take<T>(_: T) -> bool { false }
diff --git a/src/test/ui/moves/move-in-guard-2.stderr b/src/test/ui/moves/move-in-guard-2.stderr
index 0f4895c2ac132..5277a812a44c8 100644
--- a/src/test/ui/moves/move-in-guard-2.stderr
+++ b/src/test/ui/moves/move-in-guard-2.stderr
@@ -7,7 +7,7 @@ LL |     let x: Box<_> = Box::new(1);
 LL |         (_, 2) if take(x) => (),
    |                        ^ value used here after move
    |
-note: consider changing this parameter type in `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
   --> $DIR/move-in-guard-2.rs:13:15
    |
 LL | fn take<T>(_: T) -> bool { false }
diff --git a/src/test/ui/moves/moves-based-on-type-exprs.stderr b/src/test/ui/moves/moves-based-on-type-exprs.stderr
index 78138d214f9a4..37fb40ffe78c0 100644
--- a/src/test/ui/moves/moves-based-on-type-exprs.stderr
+++ b/src/test/ui/moves/moves-based-on-type-exprs.stderr
@@ -108,7 +108,7 @@ LL |         _ if guard(x) => 10,
 LL |     touch(&x);
    |           ^^ value borrowed here after move
    |
-note: consider changing this parameter type in `guard` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `guard` to borrow instead if ownering the value isn't necessary
   --> $DIR/moves-based-on-type-exprs.rs:6:14
    |
 LL | fn guard(_s: String) -> bool {panic!()}
diff --git a/src/test/ui/union/union-move.mirunsafeck.stderr b/src/test/ui/union/union-move.mirunsafeck.stderr
index 91f2eaad944eb..46b7be440e04e 100644
--- a/src/test/ui/union/union-move.mirunsafeck.stderr
+++ b/src/test/ui/union/union-move.mirunsafeck.stderr
@@ -9,7 +9,7 @@ LL |         move_out(x.f1_nocopy);
 LL |         move_out(x.f2_nocopy);
    |                  ^^^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
@@ -28,7 +28,7 @@ LL |         move_out(x.f2_nocopy);
 LL |         move_out(x.f3_copy);
    |                  ^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
diff --git a/src/test/ui/union/union-move.thirunsafeck.stderr b/src/test/ui/union/union-move.thirunsafeck.stderr
index 91f2eaad944eb..46b7be440e04e 100644
--- a/src/test/ui/union/union-move.thirunsafeck.stderr
+++ b/src/test/ui/union/union-move.thirunsafeck.stderr
@@ -9,7 +9,7 @@ LL |         move_out(x.f1_nocopy);
 LL |         move_out(x.f2_nocopy);
    |                  ^^^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
@@ -28,7 +28,7 @@ LL |         move_out(x.f2_nocopy);
 LL |         move_out(x.f3_copy);
    |                  ^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
diff --git a/src/test/ui/unsized-locals/borrow-after-move.stderr b/src/test/ui/unsized-locals/borrow-after-move.stderr
index e6964a1984238..f63684407ecb2 100644
--- a/src/test/ui/unsized-locals/borrow-after-move.stderr
+++ b/src/test/ui/unsized-locals/borrow-after-move.stderr
@@ -29,7 +29,7 @@ LL |         drop_unsized(y);
 LL |         println!("{}", &y);
    |                        ^^ value borrowed here after move
    |
-note: consider changing this parameter type in `drop_unsized` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `drop_unsized` to borrow instead if ownering the value isn't necessary
   --> $DIR/borrow-after-move.rs:14:31
    |
 LL | fn drop_unsized<T: ?Sized>(_: T) {}
diff --git a/src/test/ui/unsized-locals/double-move.stderr b/src/test/ui/unsized-locals/double-move.stderr
index 7d7586b0a0bc0..b883067427f43 100644
--- a/src/test/ui/unsized-locals/double-move.stderr
+++ b/src/test/ui/unsized-locals/double-move.stderr
@@ -17,7 +17,7 @@ LL |         drop_unsized(y);
 LL |         drop_unsized(y);
    |                      ^ value used here after move
    |
-note: consider changing this parameter type in `drop_unsized` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `drop_unsized` to borrow instead if ownering the value isn't necessary
   --> $DIR/double-move.rs:14:31
    |
 LL | fn drop_unsized<T: ?Sized>(_: T) {}
diff --git a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
index a671434a30394..7d94aa216828c 100644
--- a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
+++ b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
@@ -10,7 +10,7 @@ LL |
 LL |     let x = n.to_string();
    |             ^^^^^^^^^^^^^ value borrowed here after move
    |
-note: consider changing this parameter type in `push` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in method `push` to borrow instead if ownering the value isn't necessary
   --> $DIR/use-after-move-implicity-coerced-object.rs:17:27
    |
 LL |     fn push(&mut self, n: Box<dyn ToString + 'static>) {

From d687d46f68295c5e8aa318492500d22450d89b20 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 13:51:44 -0700
Subject: [PATCH 07/15] Tweak output in for loops

Do not suggest `.clone()` as we already suggest borrowing the iterated
value.
---
 .../src/diagnostics/conflict_errors.rs             | 14 +++++++++++---
 src/test/ui/issues/issue-61108.stderr              |  4 ----
 src/test/ui/issues/issue-64559.stderr              |  4 ----
 src/test/ui/moves/move-fn-self-receiver.stderr     |  4 ----
 .../ui/suggestions/borrow-for-loop-head.stderr     |  4 ----
 5 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 18d8bbf90475a..e917d527eb3e4 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -397,8 +397,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         && let Some(node) = hir.find(hir.local_def_id_to_hir_id(def_id))
                         && let Some(fn_sig) = node.fn_sig()
                         && let Some(ident) = node.ident()
-                        && let Some(pos) = args.iter()
-                            .position(|arg| arg.hir_id == expr.hir_id)
+                        && let Some(pos) = args.iter().position(|arg| arg.hir_id == expr.hir_id)
                         && let Some(arg) = fn_sig.decl.inputs.get(pos + offset)
                     {
                         let mut span: MultiSpan = arg.span.into();
@@ -425,7 +424,16 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     }
                     let place = &self.move_data.move_paths[mpi].place;
                     let ty = place.ty(self.body, self.infcx.tcx).ty;
-                    self.suggest_cloning(err, ty, move_span);
+                    if let hir::Node::Expr(parent_expr) = parent
+                        && let hir::ExprKind::Call(call_expr, _) = parent_expr.kind
+                        && let hir::ExprKind::Path(
+                            hir::QPath::LangItem(LangItem::IntoIterIntoIter, _, _)
+                        ) = call_expr.kind
+                    {
+                        // Do not suggest `.clone()` in a `for` loop, we already suggest borrowing.
+                    } else {
+                        self.suggest_cloning(err, ty, move_span);
+                    }
                 }
             }
             if let Some(pat) = finder.pat && !seen_spans.contains(&pat.span) {
diff --git a/src/test/ui/issues/issue-61108.stderr b/src/test/ui/issues/issue-61108.stderr
index 0f6f30531b332..e5b671d7b7ab0 100644
--- a/src/test/ui/issues/issue-61108.stderr
+++ b/src/test/ui/issues/issue-61108.stderr
@@ -14,10 +14,6 @@ note: this function takes ownership of the receiver `self`, which moves `bad_let
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     for l in bad_letters.clone() {
-   |                         ++++++++
 help: consider iterating over a slice of the `Vec<char>`'s content to avoid moving into the `for` loop
    |
 LL |     for l in &bad_letters {
diff --git a/src/test/ui/issues/issue-64559.stderr b/src/test/ui/issues/issue-64559.stderr
index 5c04cefa5304b..ef178bbd15538 100644
--- a/src/test/ui/issues/issue-64559.stderr
+++ b/src/test/ui/issues/issue-64559.stderr
@@ -15,10 +15,6 @@ note: this function takes ownership of the receiver `self`, which moves `orig`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     for _val in orig.clone() {}
-   |                     ++++++++
 help: consider iterating over a slice of the `Vec<bool>`'s content to avoid moving into the `for` loop
    |
 LL |     for _val in &orig {}
diff --git a/src/test/ui/moves/move-fn-self-receiver.stderr b/src/test/ui/moves/move-fn-self-receiver.stderr
index b331b10a3b79e..c13dc58826eb8 100644
--- a/src/test/ui/moves/move-fn-self-receiver.stderr
+++ b/src/test/ui/moves/move-fn-self-receiver.stderr
@@ -127,10 +127,6 @@ LL |     for _val in implicit_into_iter {}
 LL |     implicit_into_iter;
    |     ^^^^^^^^^^^^^^^^^^ value used here after move
    |
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     for _val in implicit_into_iter.clone() {}
-   |                                   ++++++++
 help: consider iterating over a slice of the `Vec<bool>`'s content to avoid moving into the `for` loop
    |
 LL |     for _val in &implicit_into_iter {}
diff --git a/src/test/ui/suggestions/borrow-for-loop-head.stderr b/src/test/ui/suggestions/borrow-for-loop-head.stderr
index 7cd411dde6c21..0cc8994fe1f2d 100644
--- a/src/test/ui/suggestions/borrow-for-loop-head.stderr
+++ b/src/test/ui/suggestions/borrow-for-loop-head.stderr
@@ -21,10 +21,6 @@ note: this function takes ownership of the receiver `self`, which moves `a`
    |
 LL |     fn into_iter(self) -> Self::IntoIter;
    |                  ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |         for j in a.clone() {
-   |                   ++++++++
 help: consider iterating over a slice of the `Vec<i32>`'s content to avoid moving into the `for` loop
    |
 LL |         for j in &a {

From e6e7a6db2807cf68a4147bbfaa6d5e0f8c2828d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 14:10:08 -0700
Subject: [PATCH 08/15] Fix wording

---
 compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs  | 2 +-
 src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr     | 2 +-
 src/test/ui/borrowck/borrowck-consume-upcast-box.stderr     | 2 +-
 src/test/ui/borrowck/mut-borrow-in-loop-2.stderr            | 2 +-
 src/test/ui/liveness/liveness-move-call-arg.stderr          | 2 +-
 src/test/ui/liveness/liveness-use-after-send.stderr         | 2 +-
 src/test/ui/moves/borrow-closures-instead-of-move.stderr    | 6 +++---
 src/test/ui/moves/move-guard-same-consts.stderr             | 2 +-
 src/test/ui/moves/move-in-guard-1.stderr                    | 2 +-
 src/test/ui/moves/move-in-guard-2.stderr                    | 2 +-
 src/test/ui/moves/moves-based-on-type-exprs.stderr          | 2 +-
 src/test/ui/union/union-move.mirunsafeck.stderr             | 4 ++--
 src/test/ui/union/union-move.thirunsafeck.stderr            | 4 ++--
 src/test/ui/unsized-locals/borrow-after-move.stderr         | 2 +-
 src/test/ui/unsized-locals/double-move.stderr               | 2 +-
 .../ui/use/use-after-move-implicity-coerced-object.stderr   | 2 +-
 16 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index e917d527eb3e4..5bbeaa631c620 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -403,7 +403,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         let mut span: MultiSpan = arg.span.into();
                         span.push_span_label(
                             arg.span,
-                            "this type parameter takes ownership of the value".to_string(),
+                            "this parameter takes ownership of the value".to_string(),
                         );
                         let descr = match node.fn_kind() {
                             Some(hir::intravisit::FnKind::ItemFn(..)) | None => "function",
diff --git a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
index cfaa8c08df836..c25337c0c6c63 100644
--- a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
@@ -12,7 +12,7 @@ note: consider changing this parameter type in function `consume` to borrow inst
   --> $DIR/borrowck-consume-unsize-vec.rs:3:15
    |
 LL | fn consume(_: Box<[i32]>) {
-   |    -------    ^^^^^^^^^^ this type parameter takes ownership of the value
+   |    -------    ^^^^^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider cloning the value if the performance cost is acceptable
diff --git a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
index c73d1df971acf..49d85cd5fa2a7 100644
--- a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
@@ -12,7 +12,7 @@ note: consider changing this parameter type in function `consume` to borrow inst
   --> $DIR/borrowck-consume-upcast-box.rs:5:15
    |
 LL | fn consume(_: Box<dyn Foo>) {
-   |    -------    ^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    -------    ^^^^^^^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 
diff --git a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
index 4f287d3a735e1..b441244cdfdea 100644
--- a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
+++ b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
@@ -12,7 +12,7 @@ note: consider changing this parameter type in function `handle` to borrow inste
   --> $DIR/mut-borrow-in-loop-2.rs:9:22
    |
 LL |     fn handle(value: T) -> Self;
-   |        ------        ^ this type parameter takes ownership of the value
+   |        ------        ^ this parameter takes ownership of the value
    |        |
    |        in this function
 help: consider creating a fresh reborrow of `value` here
diff --git a/src/test/ui/liveness/liveness-move-call-arg.stderr b/src/test/ui/liveness/liveness-move-call-arg.stderr
index 4a869cdce4a17..5b5ac65113fdd 100644
--- a/src/test/ui/liveness/liveness-move-call-arg.stderr
+++ b/src/test/ui/liveness/liveness-move-call-arg.stderr
@@ -13,7 +13,7 @@ note: consider changing this parameter type in function `take` to borrow instead
   --> $DIR/liveness-move-call-arg.rs:1:13
    |
 LL | fn take(_x: Box<isize>) {}
-   |    ----     ^^^^^^^^^^ this type parameter takes ownership of the value
+   |    ----     ^^^^^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider cloning the value if the performance cost is acceptable
diff --git a/src/test/ui/liveness/liveness-use-after-send.stderr b/src/test/ui/liveness/liveness-use-after-send.stderr
index cf4aa8fc9c414..3dbe5ac517e43 100644
--- a/src/test/ui/liveness/liveness-use-after-send.stderr
+++ b/src/test/ui/liveness/liveness-use-after-send.stderr
@@ -12,7 +12,7 @@ note: consider changing this parameter type in function `send` to borrow instead
   --> $DIR/liveness-use-after-send.rs:3:54
    |
 LL | fn send<T:Send + std::fmt::Debug>(ch: Chan<T>, data: T) {
-   |    ---- in this function                             ^ this type parameter takes ownership of the value
+   |    ---- in this function                             ^ this parameter takes ownership of the value
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider cloning the value if the performance cost is acceptable
    |
diff --git a/src/test/ui/moves/borrow-closures-instead-of-move.stderr b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
index d3f250e69b24c..b68552220397c 100644
--- a/src/test/ui/moves/borrow-closures-instead-of-move.stderr
+++ b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
@@ -12,7 +12,7 @@ note: consider changing this parameter type in function `takes_fnonce` to borrow
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
-   |    ------------    ^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    ------------    ^^^^^^^^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider borrowing `f`
@@ -36,7 +36,7 @@ note: consider changing this parameter type in function `takes_fnonce` to borrow
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
-   |    ------------    ^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    ------------    ^^^^^^^^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider mutably borrowing `m`
@@ -62,7 +62,7 @@ note: consider changing this parameter type in function `takes_fnonce` to borrow
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
-   |    ------------    ^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |    ------------    ^^^^^^^^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider mutably borrowing `closure`
diff --git a/src/test/ui/moves/move-guard-same-consts.stderr b/src/test/ui/moves/move-guard-same-consts.stderr
index 687e8497dc6e8..440a908a3c662 100644
--- a/src/test/ui/moves/move-guard-same-consts.stderr
+++ b/src/test/ui/moves/move-guard-same-consts.stderr
@@ -13,7 +13,7 @@ note: consider changing this parameter type in function `take` to borrow instead
   --> $DIR/move-guard-same-consts.rs:25:15
    |
 LL | fn take<T>(_: T) -> bool { false }
-   |    ----       ^ this type parameter takes ownership of the value
+   |    ----       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider cloning the value if the performance cost is acceptable
diff --git a/src/test/ui/moves/move-in-guard-1.stderr b/src/test/ui/moves/move-in-guard-1.stderr
index a21dca7f16ee5..e054f31349a6c 100644
--- a/src/test/ui/moves/move-in-guard-1.stderr
+++ b/src/test/ui/moves/move-in-guard-1.stderr
@@ -13,7 +13,7 @@ note: consider changing this parameter type in function `take` to borrow instead
   --> $DIR/move-in-guard-1.rs:15:15
    |
 LL | fn take<T>(_: T) -> bool { false }
-   |    ----       ^ this type parameter takes ownership of the value
+   |    ----       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider cloning the value if the performance cost is acceptable
diff --git a/src/test/ui/moves/move-in-guard-2.stderr b/src/test/ui/moves/move-in-guard-2.stderr
index 5277a812a44c8..49267c2763159 100644
--- a/src/test/ui/moves/move-in-guard-2.stderr
+++ b/src/test/ui/moves/move-in-guard-2.stderr
@@ -11,7 +11,7 @@ note: consider changing this parameter type in function `take` to borrow instead
   --> $DIR/move-in-guard-2.rs:13:15
    |
 LL | fn take<T>(_: T) -> bool { false }
-   |    ----       ^ this type parameter takes ownership of the value
+   |    ----       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider cloning the value if the performance cost is acceptable
diff --git a/src/test/ui/moves/moves-based-on-type-exprs.stderr b/src/test/ui/moves/moves-based-on-type-exprs.stderr
index 37fb40ffe78c0..6efda8c5e8366 100644
--- a/src/test/ui/moves/moves-based-on-type-exprs.stderr
+++ b/src/test/ui/moves/moves-based-on-type-exprs.stderr
@@ -112,7 +112,7 @@ note: consider changing this parameter type in function `guard` to borrow instea
   --> $DIR/moves-based-on-type-exprs.rs:6:14
    |
 LL | fn guard(_s: String) -> bool {panic!()}
-   |    -----     ^^^^^^ this type parameter takes ownership of the value
+   |    -----     ^^^^^^ this parameter takes ownership of the value
    |    |
    |    in this function
 help: consider cloning the value if the performance cost is acceptable
diff --git a/src/test/ui/union/union-move.mirunsafeck.stderr b/src/test/ui/union/union-move.mirunsafeck.stderr
index 46b7be440e04e..c695282fbb0d3 100644
--- a/src/test/ui/union/union-move.mirunsafeck.stderr
+++ b/src/test/ui/union/union-move.mirunsafeck.stderr
@@ -13,7 +13,7 @@ note: consider changing this parameter type in function `move_out` to borrow ins
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
-   |    --------       ^ this type parameter takes ownership of the value
+   |    --------       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 
@@ -32,7 +32,7 @@ note: consider changing this parameter type in function `move_out` to borrow ins
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
-   |    --------       ^ this type parameter takes ownership of the value
+   |    --------       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 
diff --git a/src/test/ui/union/union-move.thirunsafeck.stderr b/src/test/ui/union/union-move.thirunsafeck.stderr
index 46b7be440e04e..c695282fbb0d3 100644
--- a/src/test/ui/union/union-move.thirunsafeck.stderr
+++ b/src/test/ui/union/union-move.thirunsafeck.stderr
@@ -13,7 +13,7 @@ note: consider changing this parameter type in function `move_out` to borrow ins
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
-   |    --------       ^ this type parameter takes ownership of the value
+   |    --------       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 
@@ -32,7 +32,7 @@ note: consider changing this parameter type in function `move_out` to borrow ins
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
-   |    --------       ^ this type parameter takes ownership of the value
+   |    --------       ^ this parameter takes ownership of the value
    |    |
    |    in this function
 
diff --git a/src/test/ui/unsized-locals/borrow-after-move.stderr b/src/test/ui/unsized-locals/borrow-after-move.stderr
index f63684407ecb2..e11c398e8d030 100644
--- a/src/test/ui/unsized-locals/borrow-after-move.stderr
+++ b/src/test/ui/unsized-locals/borrow-after-move.stderr
@@ -33,7 +33,7 @@ note: consider changing this parameter type in function `drop_unsized` to borrow
   --> $DIR/borrow-after-move.rs:14:31
    |
 LL | fn drop_unsized<T: ?Sized>(_: T) {}
-   |    ------------               ^ this type parameter takes ownership of the value
+   |    ------------               ^ this parameter takes ownership of the value
    |    |
    |    in this function
 
diff --git a/src/test/ui/unsized-locals/double-move.stderr b/src/test/ui/unsized-locals/double-move.stderr
index b883067427f43..84192e7509896 100644
--- a/src/test/ui/unsized-locals/double-move.stderr
+++ b/src/test/ui/unsized-locals/double-move.stderr
@@ -21,7 +21,7 @@ note: consider changing this parameter type in function `drop_unsized` to borrow
   --> $DIR/double-move.rs:14:31
    |
 LL | fn drop_unsized<T: ?Sized>(_: T) {}
-   |    ------------               ^ this type parameter takes ownership of the value
+   |    ------------               ^ this parameter takes ownership of the value
    |    |
    |    in this function
 
diff --git a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
index 7d94aa216828c..395bb4019fd61 100644
--- a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
+++ b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
@@ -14,7 +14,7 @@ note: consider changing this parameter type in method `push` to borrow instead i
   --> $DIR/use-after-move-implicity-coerced-object.rs:17:27
    |
 LL |     fn push(&mut self, n: Box<dyn ToString + 'static>) {
-   |        ----               ^^^^^^^^^^^^^^^^^^^^^^^^^^^ this type parameter takes ownership of the value
+   |        ----               ^^^^^^^^^^^^^^^^^^^^^^^^^^^ this parameter takes ownership of the value
    |        |
    |        in this method
 

From 24f80ea7d758361f0b296ad93b9613b13dbd2235 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 14:22:35 -0700
Subject: [PATCH 09/15] Fix rustfmt

---
 src/tools/rustfmt/src/expr.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tools/rustfmt/src/expr.rs b/src/tools/rustfmt/src/expr.rs
index d5611082f0103..414e767690bd0 100644
--- a/src/tools/rustfmt/src/expr.rs
+++ b/src/tools/rustfmt/src/expr.rs
@@ -660,7 +660,7 @@ fn to_control_flow(expr: &ast::Expr, expr_type: ExprType) -> Option<ControlFlow<
         ast::ExprKind::ForLoop(ref pat, ref cond, ref block, label) => {
             Some(ControlFlow::new_for(pat, cond, block, label, expr.span))
         }
-        ast::ExprKind::Loop(ref block, label) => {
+        ast::ExprKind::Loop(ref block, label, _) => {
             Some(ControlFlow::new_loop(block, label, expr.span))
         }
         ast::ExprKind::While(ref cond, ref block, label) => {

From 5993f5d0f88a22b87bf1888138055864c3c9e52b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 15:08:38 -0700
Subject: [PATCH 10/15] Tweak output to account for alternative bindings in the
 same pattern

---
 .../src/diagnostics/conflict_errors.rs        | 39 ++++++++-----------
 ...atterns-slice-patterns-box-patterns.stderr | 10 +----
 2 files changed, 19 insertions(+), 30 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 5bbeaa631c620..cfbd6d12578b7 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -192,26 +192,23 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     is_loop_move = true;
                 }
 
-                self.suggest_ref_or_clone(
-                    mpi,
-                    move_span,
-                    &mut err,
-                    &mut seen_spans,
-                    &mut in_pattern,
-                );
+                if !seen_spans.contains(&move_span) {
+                    self.suggest_ref_or_clone(mpi, move_span, &mut err, &mut in_pattern);
 
-                self.explain_captures(
-                    &mut err,
-                    span,
-                    move_span,
-                    move_spans,
-                    *moved_place,
-                    partially_str,
-                    loop_message,
-                    move_msg,
-                    is_loop_move,
-                    maybe_reinitialized_locations.is_empty(),
-                );
+                    self.explain_captures(
+                        &mut err,
+                        span,
+                        move_span,
+                        move_spans,
+                        *moved_place,
+                        partially_str,
+                        loop_message,
+                        move_msg,
+                        is_loop_move,
+                        maybe_reinitialized_locations.is_empty(),
+                    );
+                }
+                seen_spans.insert(move_span);
             }
 
             use_spans.var_path_only_subdiag(&mut err, desired_action);
@@ -312,7 +309,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         mpi: MovePathIndex,
         move_span: Span,
         err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>,
-        seen_spans: &mut FxHashSet<Span>,
         in_pattern: &mut bool,
     ) {
         struct ExpressionFinder<'hir> {
@@ -436,7 +432,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     }
                 }
             }
-            if let Some(pat) = finder.pat && !seen_spans.contains(&pat.span) {
+            if let Some(pat) = finder.pat {
                 *in_pattern = true;
                 err.span_suggestion_verbose(
                     pat.span.shrink_to_lo(),
@@ -444,7 +440,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     "ref ".to_string(),
                     Applicability::MachineApplicable,
                 );
-                seen_spans.insert(pat.span);
             }
         }
     }
diff --git a/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr b/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
index d06b3bc1c3e60..50eee1049db6e 100644
--- a/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
+++ b/src/test/ui/borrowck/bindings-after-at-or-patterns-slice-patterns-box-patterns.stderr
@@ -76,10 +76,7 @@ LL | fn bindings_after_at_or_patterns_move(x: Option<Test>) {
    |                                       - move occurs because `x` has type `Option<Test>`, which does not implement the `Copy` trait
 LL |     match x {
 LL |         foo @ Some(Test::Foo | Test::Bar) => (),
-   |         ---
-   |         |
-   |         value moved here
-   |         value moved here
+   |         --- value moved here
 ...
 LL |     &x;
    |     ^^ value borrowed here after move
@@ -132,10 +129,7 @@ LL | fn bindings_after_at_slice_patterns_or_patterns_moves(x: [Option<Test>; 4])
    |                                                       - move occurs because `x` has type `[Option<Test>; 4]`, which does not implement the `Copy` trait
 LL |     match x {
 LL |         a @ [.., Some(Test::Foo | Test::Bar)] => (),
-   |         -
-   |         |
-   |         value moved here
-   |         value moved here
+   |         - value moved here
 ...
 LL |     &x;
    |     ^^ value borrowed here after move

From 53a711fdebd10e2a4426067d99fa04437f8a32dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Thu, 3 Nov 2022 15:10:29 -0700
Subject: [PATCH 11/15] Fix rebase

---
 src/test/ui/track-diagnostics/track2.stderr | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/test/ui/track-diagnostics/track2.stderr b/src/test/ui/track-diagnostics/track2.stderr
index 38a621da81644..53f20259a8e5f 100644
--- a/src/test/ui/track-diagnostics/track2.stderr
+++ b/src/test/ui/track-diagnostics/track2.stderr
@@ -7,6 +7,11 @@ LL |     let _moved @ _from = String::from("foo");
    |         |        value moved here
    |         value used here after move
 -Ztrack-diagnostics: created at compiler/rustc_borrowck/src/borrowck_errors.rs:LL:CC
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let _moved @ ref _from = String::from("foo");
+   |                  +++
 
 error: aborting due to previous error
 

From 3c905d4ccdcec76358716285a7f6409c3b84e7be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Fri, 11 Nov 2022 16:57:01 -0800
Subject: [PATCH 12/15] review comments: inline bindings and fix typo

---
 .../src/diagnostics/conflict_errors.rs             | 14 +++++++++-----
 .../ui/borrowck/borrowck-consume-unsize-vec.stderr |  2 +-
 .../ui/borrowck/borrowck-consume-upcast-box.stderr |  2 +-
 src/test/ui/borrowck/mut-borrow-in-loop-2.stderr   |  2 +-
 src/test/ui/liveness/liveness-move-call-arg.stderr |  2 +-
 .../ui/liveness/liveness-use-after-send.stderr     |  2 +-
 .../moves/borrow-closures-instead-of-move.stderr   |  6 +++---
 src/test/ui/moves/move-guard-same-consts.stderr    |  2 +-
 src/test/ui/moves/move-in-guard-1.stderr           |  2 +-
 src/test/ui/moves/move-in-guard-2.stderr           |  2 +-
 src/test/ui/moves/moves-based-on-type-exprs.stderr |  2 +-
 src/test/ui/union/union-move.mirunsafeck.stderr    |  4 ++--
 src/test/ui/union/union-move.thirunsafeck.stderr   |  4 ++--
 .../ui/unsized-locals/borrow-after-move.stderr     |  2 +-
 src/test/ui/unsized-locals/double-move.stderr      |  2 +-
 .../use-after-move-implicity-coerced-object.stderr |  2 +-
 16 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index cfbd6d12578b7..0d539783162e5 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -721,11 +721,15 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let tcx = self.infcx.tcx;
         // Try to find predicates on *generic params* that would allow copying `ty`
         let infcx = tcx.infer_ctxt().build();
-        let clone_did = tcx.lang_items().clone_trait().unwrap();
-        let params = ty::List::empty();
-        let ty = tcx.erase_regions(ty);
-        let env = self.param_env;
-        if infcx.type_implements_trait(clone_did, ty, params, env).must_apply_modulo_regions() {
+        if infcx
+            .type_implements_trait(
+                tcx.lang_items().clone_trait().unwrap(),
+                tcx.erase_regions(ty),
+                ty::List::empty(),
+                self.param_env,
+            )
+            .must_apply_modulo_regions()
+        {
             err.span_suggestion_verbose(
                 span.shrink_to_hi(),
                 "consider cloning the value if the performance cost is acceptable",
diff --git a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
index c25337c0c6c63..d2e9497d0795c 100644
--- a/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-unsize-vec.stderr
@@ -8,7 +8,7 @@ LL |     consume(b);
 LL |     consume(b);
    |             ^ value used here after move
    |
-note: consider changing this parameter type in function `consume` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `consume` to borrow instead if owning the value isn't necessary
   --> $DIR/borrowck-consume-unsize-vec.rs:3:15
    |
 LL | fn consume(_: Box<[i32]>) {
diff --git a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
index 49d85cd5fa2a7..ed7e883ca6392 100644
--- a/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
+++ b/src/test/ui/borrowck/borrowck-consume-upcast-box.stderr
@@ -8,7 +8,7 @@ LL |     consume(b);
 LL |     consume(b);
    |             ^ value used here after move
    |
-note: consider changing this parameter type in function `consume` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `consume` to borrow instead if owning the value isn't necessary
   --> $DIR/borrowck-consume-upcast-box.rs:5:15
    |
 LL | fn consume(_: Box<dyn Foo>) {
diff --git a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
index b441244cdfdea..74e7067c9afaa 100644
--- a/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
+++ b/src/test/ui/borrowck/mut-borrow-in-loop-2.stderr
@@ -8,7 +8,7 @@ LL |     for _ in 0..3 {
 LL |         Other::handle(value);
    |                       ^^^^^ value moved here, in previous iteration of loop
    |
-note: consider changing this parameter type in function `handle` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `handle` to borrow instead if owning the value isn't necessary
   --> $DIR/mut-borrow-in-loop-2.rs:9:22
    |
 LL |     fn handle(value: T) -> Self;
diff --git a/src/test/ui/liveness/liveness-move-call-arg.stderr b/src/test/ui/liveness/liveness-move-call-arg.stderr
index 5b5ac65113fdd..d14cd6cb4e03a 100644
--- a/src/test/ui/liveness/liveness-move-call-arg.stderr
+++ b/src/test/ui/liveness/liveness-move-call-arg.stderr
@@ -9,7 +9,7 @@ LL |     loop {
 LL |         take(x);
    |              ^ value moved here, in previous iteration of loop
    |
-note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if owning the value isn't necessary
   --> $DIR/liveness-move-call-arg.rs:1:13
    |
 LL | fn take(_x: Box<isize>) {}
diff --git a/src/test/ui/liveness/liveness-use-after-send.stderr b/src/test/ui/liveness/liveness-use-after-send.stderr
index 3dbe5ac517e43..65d55ca8f7073 100644
--- a/src/test/ui/liveness/liveness-use-after-send.stderr
+++ b/src/test/ui/liveness/liveness-use-after-send.stderr
@@ -8,7 +8,7 @@ LL |     send(ch, message);
 LL |     println!("{}", message);
    |                    ^^^^^^^ value borrowed here after move
    |
-note: consider changing this parameter type in function `send` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `send` to borrow instead if owning the value isn't necessary
   --> $DIR/liveness-use-after-send.rs:3:54
    |
 LL | fn send<T:Send + std::fmt::Debug>(ch: Chan<T>, data: T) {
diff --git a/src/test/ui/moves/borrow-closures-instead-of-move.stderr b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
index b68552220397c..fbeeaf646e1ee 100644
--- a/src/test/ui/moves/borrow-closures-instead-of-move.stderr
+++ b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
@@ -8,7 +8,7 @@ LL |     loop {
 LL |         takes_fnonce(f);
    |                      ^ value moved here, in previous iteration of loop
    |
-note: consider changing this parameter type in function `takes_fnonce` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `takes_fnonce` to borrow instead if owning the value isn't necessary
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
@@ -32,7 +32,7 @@ LL |         takes_fnonce(m);
 LL |     takes_fnonce(m);
    |                  ^ value used here after move
    |
-note: consider changing this parameter type in function `takes_fnonce` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `takes_fnonce` to borrow instead if owning the value isn't necessary
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
@@ -58,7 +58,7 @@ note: closure cannot be moved more than once as it is not `Copy` due to moving t
    |
 LL |         x += 1;
    |         ^
-note: consider changing this parameter type in function `takes_fnonce` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `takes_fnonce` to borrow instead if owning the value isn't necessary
   --> $DIR/borrow-closures-instead-of-move.rs:34:20
    |
 LL | fn takes_fnonce(_: impl FnOnce()) {}
diff --git a/src/test/ui/moves/move-guard-same-consts.stderr b/src/test/ui/moves/move-guard-same-consts.stderr
index 440a908a3c662..86e5f65248b97 100644
--- a/src/test/ui/moves/move-guard-same-consts.stderr
+++ b/src/test/ui/moves/move-guard-same-consts.stderr
@@ -9,7 +9,7 @@ LL |         (1, 2) if take(x) => (),
 LL |         (1, 2) if take(x) => (),
    |                        ^ value used here after move
    |
-note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if owning the value isn't necessary
   --> $DIR/move-guard-same-consts.rs:25:15
    |
 LL | fn take<T>(_: T) -> bool { false }
diff --git a/src/test/ui/moves/move-in-guard-1.stderr b/src/test/ui/moves/move-in-guard-1.stderr
index e054f31349a6c..f04cb34d7c46e 100644
--- a/src/test/ui/moves/move-in-guard-1.stderr
+++ b/src/test/ui/moves/move-in-guard-1.stderr
@@ -9,7 +9,7 @@ LL |         (1, _) if take(x) => (),
 LL |         (_, 2) if take(x) => (),
    |                        ^ value used here after move
    |
-note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if owning the value isn't necessary
   --> $DIR/move-in-guard-1.rs:15:15
    |
 LL | fn take<T>(_: T) -> bool { false }
diff --git a/src/test/ui/moves/move-in-guard-2.stderr b/src/test/ui/moves/move-in-guard-2.stderr
index 49267c2763159..26047861f55d7 100644
--- a/src/test/ui/moves/move-in-guard-2.stderr
+++ b/src/test/ui/moves/move-in-guard-2.stderr
@@ -7,7 +7,7 @@ LL |     let x: Box<_> = Box::new(1);
 LL |         (_, 2) if take(x) => (),
    |                        ^ value used here after move
    |
-note: consider changing this parameter type in function `take` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `take` to borrow instead if owning the value isn't necessary
   --> $DIR/move-in-guard-2.rs:13:15
    |
 LL | fn take<T>(_: T) -> bool { false }
diff --git a/src/test/ui/moves/moves-based-on-type-exprs.stderr b/src/test/ui/moves/moves-based-on-type-exprs.stderr
index 6efda8c5e8366..838b1282cb4ed 100644
--- a/src/test/ui/moves/moves-based-on-type-exprs.stderr
+++ b/src/test/ui/moves/moves-based-on-type-exprs.stderr
@@ -108,7 +108,7 @@ LL |         _ if guard(x) => 10,
 LL |     touch(&x);
    |           ^^ value borrowed here after move
    |
-note: consider changing this parameter type in function `guard` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `guard` to borrow instead if owning the value isn't necessary
   --> $DIR/moves-based-on-type-exprs.rs:6:14
    |
 LL | fn guard(_s: String) -> bool {panic!()}
diff --git a/src/test/ui/union/union-move.mirunsafeck.stderr b/src/test/ui/union/union-move.mirunsafeck.stderr
index c695282fbb0d3..6381ae874ba81 100644
--- a/src/test/ui/union/union-move.mirunsafeck.stderr
+++ b/src/test/ui/union/union-move.mirunsafeck.stderr
@@ -9,7 +9,7 @@ LL |         move_out(x.f1_nocopy);
 LL |         move_out(x.f2_nocopy);
    |                  ^^^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if owning the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
@@ -28,7 +28,7 @@ LL |         move_out(x.f2_nocopy);
 LL |         move_out(x.f3_copy);
    |                  ^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if owning the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
diff --git a/src/test/ui/union/union-move.thirunsafeck.stderr b/src/test/ui/union/union-move.thirunsafeck.stderr
index c695282fbb0d3..6381ae874ba81 100644
--- a/src/test/ui/union/union-move.thirunsafeck.stderr
+++ b/src/test/ui/union/union-move.thirunsafeck.stderr
@@ -9,7 +9,7 @@ LL |         move_out(x.f1_nocopy);
 LL |         move_out(x.f2_nocopy);
    |                  ^^^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if owning the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
@@ -28,7 +28,7 @@ LL |         move_out(x.f2_nocopy);
 LL |         move_out(x.f3_copy);
    |                  ^^^^^^^^^ value used here after move
    |
-note: consider changing this parameter type in function `move_out` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `move_out` to borrow instead if owning the value isn't necessary
   --> $DIR/union-move.rs:10:19
    |
 LL | fn move_out<T>(x: T) {}
diff --git a/src/test/ui/unsized-locals/borrow-after-move.stderr b/src/test/ui/unsized-locals/borrow-after-move.stderr
index e11c398e8d030..d8bffd4f9cf3e 100644
--- a/src/test/ui/unsized-locals/borrow-after-move.stderr
+++ b/src/test/ui/unsized-locals/borrow-after-move.stderr
@@ -29,7 +29,7 @@ LL |         drop_unsized(y);
 LL |         println!("{}", &y);
    |                        ^^ value borrowed here after move
    |
-note: consider changing this parameter type in function `drop_unsized` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `drop_unsized` to borrow instead if owning the value isn't necessary
   --> $DIR/borrow-after-move.rs:14:31
    |
 LL | fn drop_unsized<T: ?Sized>(_: T) {}
diff --git a/src/test/ui/unsized-locals/double-move.stderr b/src/test/ui/unsized-locals/double-move.stderr
index 84192e7509896..71534818141ca 100644
--- a/src/test/ui/unsized-locals/double-move.stderr
+++ b/src/test/ui/unsized-locals/double-move.stderr
@@ -17,7 +17,7 @@ LL |         drop_unsized(y);
 LL |         drop_unsized(y);
    |                      ^ value used here after move
    |
-note: consider changing this parameter type in function `drop_unsized` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in function `drop_unsized` to borrow instead if owning the value isn't necessary
   --> $DIR/double-move.rs:14:31
    |
 LL | fn drop_unsized<T: ?Sized>(_: T) {}
diff --git a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
index 395bb4019fd61..dfa0c04836eb3 100644
--- a/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
+++ b/src/test/ui/use/use-after-move-implicity-coerced-object.stderr
@@ -10,7 +10,7 @@ LL |
 LL |     let x = n.to_string();
    |             ^^^^^^^^^^^^^ value borrowed here after move
    |
-note: consider changing this parameter type in method `push` to borrow instead if ownering the value isn't necessary
+note: consider changing this parameter type in method `push` to borrow instead if owning the value isn't necessary
   --> $DIR/use-after-move-implicity-coerced-object.rs:17:27
    |
 LL |     fn push(&mut self, n: Box<dyn ToString + 'static>) {

From 3a471b5fd8dcf4444be200b41925396a90a2188a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Tue, 15 Nov 2022 09:01:20 -0800
Subject: [PATCH 13/15] Account for `x @ y` and suggest `ref x @ ref y`

---
 .../src/diagnostics/conflict_errors.rs        |  30 ++--
 .../src/thir/pattern/check_match.rs           |  16 ++-
 ...can-live-while-the-other-survives-1.stderr |  10 ++
 .../borrowck-move-and-move.stderr             |  20 +--
 ...t-by-move-and-ref-inverse-promotion.stderr |   5 +
 ...orrowck-pat-by-move-and-ref-inverse.stderr | 133 +++++++++++++++++-
 .../borrowck-pat-ref-mut-twice.stderr         |  20 +++
 .../copy-and-move-mixed.stderr                |   4 +-
 ...inding-modes-both-sides-independent.stderr |   5 +
 .../ui/suggestions/ref-pattern-binding.fixed  |  19 +++
 .../ui/suggestions/ref-pattern-binding.rs     |  19 +++
 .../ui/suggestions/ref-pattern-binding.stderr | 107 ++++++++++++++
 src/test/ui/track-diagnostics/track2.stderr   |   4 +-
 13 files changed, 362 insertions(+), 30 deletions(-)
 create mode 100644 src/test/ui/suggestions/ref-pattern-binding.fixed
 create mode 100644 src/test/ui/suggestions/ref-pattern-binding.rs
 create mode 100644 src/test/ui/suggestions/ref-pattern-binding.stderr

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 0d539783162e5..70ad3b62805fa 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -315,6 +315,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             expr_span: Span,
             expr: Option<&'hir hir::Expr<'hir>>,
             pat: Option<&'hir hir::Pat<'hir>>,
+            parent_pat: Option<&'hir hir::Pat<'hir>>,
         }
         impl<'hir> Visitor<'hir> for ExpressionFinder<'hir> {
             fn visit_expr(&mut self, e: &'hir hir::Expr<'hir>) {
@@ -327,10 +328,19 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 if p.span == self.expr_span {
                     self.pat = Some(p);
                 }
-                if let hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, i, _) = p.kind
-                    && i.span == self.expr_span
-                {
-                    self.pat = Some(p);
+                if let hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, i, sub) = p.kind {
+                    if i.span == self.expr_span || p.span == self.expr_span {
+                        self.pat = Some(p);
+                    }
+                    // Check if we are in a situation of `ident @ ident` where we want to suggest
+                    // `ref ident @ ref ident` or `ref ident @ Struct { ref ident }`.
+                    if let Some(subpat) = sub && self.pat.is_none() {
+                        self.visit_pat(subpat);
+                        if self.pat.is_some() {
+                            self.parent_pat = Some(p);
+                        }
+                        return;
+                    }
                 }
                 hir::intravisit::walk_pat(self, p);
             }
@@ -349,6 +359,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 expr_span: move_span,
                 expr: None,
                 pat: None,
+                parent_pat: None,
             };
             finder.visit_expr(expr);
             if let Some(span) = span && let Some(expr) = finder.expr {
@@ -414,7 +425,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             span,
                             format!(
                                 "consider changing this parameter type in {descr} `{ident}` to \
-                                 borrow instead if ownering the value isn't necessary",
+                                 borrow instead if owning the value isn't necessary",
                             ),
                         );
                     }
@@ -434,10 +445,13 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
             }
             if let Some(pat) = finder.pat {
                 *in_pattern = true;
-                err.span_suggestion_verbose(
-                    pat.span.shrink_to_lo(),
+                let mut sugg = vec![(pat.span.shrink_to_lo(), "ref ".to_string())];
+                if let Some(pat) = finder.parent_pat {
+                    sugg.insert(0, (pat.span.shrink_to_lo(), "ref ".to_string()));
+                }
+                err.multipart_suggestion_verbose(
                     "borrow this binding in the pattern to avoid moving the value",
-                    "ref ".to_string(),
+                    sugg,
                     Applicability::MachineApplicable,
                 );
             }
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index ba04cb6eef82d..e369dba55242c 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -1044,11 +1044,19 @@ fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_, '_>, pat: &Pa
                     name,
                     typeck_results.node_type(pat.hir_id),
                 );
-                sess.struct_span_err(pat.span, "borrow of moved value")
-                    .span_label(binding_span, format!("value moved into `{}` here", name))
+                let mut err = sess.struct_span_err(pat.span, "borrow of moved value");
+                err.span_label(binding_span, format!("value moved into `{}` here", name))
                     .span_label(binding_span, occurs_because)
-                    .span_labels(conflicts_ref, "value borrowed here after move")
-                    .emit();
+                    .span_labels(conflicts_ref, "value borrowed here after move");
+                if pat.span.contains(binding_span) {
+                    err.span_suggestion_verbose(
+                        binding_span.shrink_to_lo(),
+                        "borrow this binding in the pattern to avoid moving the value",
+                        "ref ".to_string(),
+                        Applicability::MachineApplicable,
+                    );
+                }
+                err.emit();
             }
             return;
         }
diff --git a/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr b/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
index e79e4e7dfa336..c8b45fd24d98c 100644
--- a/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
+++ b/src/test/ui/pattern/bindings-after-at/bind-by-move-neither-can-live-while-the-other-survives-1.stderr
@@ -16,6 +16,11 @@ LL |         Some(_z @ ref _y) => {}
    |              |    value borrowed here after move
    |              value moved into `_z` here
    |              move occurs because `_z` has type `X` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         Some(ref _z @ ref _y) => {}
+   |              +++
 
 error: cannot move out of value because it is borrowed
   --> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:26:14
@@ -35,6 +40,11 @@ LL |         Some(_z @ ref mut _y) => {}
    |              |    value borrowed here after move
    |              value moved into `_z` here
    |              move occurs because `_z` has type `X` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         Some(ref _z @ ref mut _y) => {}
+   |              +++
 
 error[E0382]: borrow of moved value
   --> $DIR/bind-by-move-neither-can-live-while-the-other-survives-1.rs:12:14
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
index 077583dd2527c..324897151124c 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-move-and-move.stderr
@@ -9,8 +9,8 @@ LL |     let a @ b = U;
    |
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let a @ ref b = U;
-   |             +++
+LL |     let ref a @ ref b = U;
+   |         +++     +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:13:9
@@ -23,8 +23,8 @@ LL |     let a @ (b, c) = (U, U);
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let a @ (b, ref c) = (U, U);
-   |                 +++
+LL |     let ref a @ (b, ref c) = (U, U);
+   |         +++         +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:15:9
@@ -37,8 +37,8 @@ LL |     let a @ (b, c) = (u(), u());
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let a @ (b, ref c) = (u(), u());
-   |                 +++
+LL |     let ref a @ (b, ref c) = (u(), u());
+   |         +++         +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-move-and-move.rs:18:16
@@ -81,8 +81,8 @@ LL |         xs @ [a, .., b] => {}
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |         xs @ [a, .., ref b] => {}
-   |                      +++
+LL |         ref xs @ [a, .., ref b] => {}
+   |         +++              +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-move-and-move.rs:29:9
@@ -95,8 +95,8 @@ LL |         xs @ [_, ys @ .., _] => {}
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |         xs @ [_, ref ys @ .., _] => {}
-   |                  +++
+LL |         ref xs @ [_, ref ys @ .., _] => {}
+   |         +++          +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-move-and-move.rs:22:12
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse-promotion.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse-promotion.stderr
index be4e81c61aa62..d6474f1b49fb0 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse-promotion.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse-promotion.stderr
@@ -7,6 +7,11 @@ LL |     let a @ ref b = U;
    |         |   value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ ref b = U;
+   |         +++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr
index a41ebf1931f94..389e86e646457 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-by-move-and-ref-inverse.stderr
@@ -7,6 +7,11 @@ LL |     let a @ ref b = U;
    |         |   value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ ref b = U;
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:24:9
@@ -18,6 +23,11 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (U, U);
    |         |            value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `(U, U)` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ (mut b @ ref mut c, d @ ref e) = (U, U);
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:24:14
@@ -28,6 +38,11 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (U, U);
    |              |       value borrowed here after move
    |              value moved into `b` here
    |              move occurs because `b` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (ref mut b @ ref mut c, d @ ref e) = (U, U);
+   |              +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:24:33
@@ -38,6 +53,11 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (U, U);
    |                                 |   value borrowed here after move
    |                                 value moved into `d` here
    |                                 move occurs because `d` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (mut b @ ref mut c, ref d @ ref e) = (U, U);
+   |                                 +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:29:9
@@ -49,6 +69,11 @@ LL |     let a @ [ref mut b, ref c] = [U, U];
    |         |    value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `[U; 2]` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ [ref mut b, ref c] = [U, U];
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:31:9
@@ -59,6 +84,11 @@ LL |     let a @ ref b = u();
    |         |   value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ ref b = u();
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:33:9
@@ -70,6 +100,11 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (u(), u());
    |         |            value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `(U, U)` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ (mut b @ ref mut c, d @ ref e) = (u(), u());
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:33:14
@@ -80,6 +115,11 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (u(), u());
    |              |       value borrowed here after move
    |              value moved into `b` here
    |              move occurs because `b` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (ref mut b @ ref mut c, d @ ref e) = (u(), u());
+   |              +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:33:33
@@ -90,6 +130,11 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (u(), u());
    |                                 |   value borrowed here after move
    |                                 value moved into `d` here
    |                                 move occurs because `d` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let a @ (mut b @ ref mut c, ref d @ ref e) = (u(), u());
+   |                                 +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:38:9
@@ -101,6 +146,11 @@ LL |     let a @ [ref mut b, ref c] = [u(), u()];
    |         |    value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `[U; 2]` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ [ref mut b, ref c] = [u(), u()];
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:42:9
@@ -111,6 +161,11 @@ LL |         a @ Some(ref b) => {}
    |         |        value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `Option<U>` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some(ref b) => {}
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:47:9
@@ -122,6 +177,11 @@ LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |         |                 value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `Option<(U, U)>` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some((mut b @ ref mut c, d @ ref e)) => {}
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:47:19
@@ -132,6 +192,11 @@ LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |                   |       value borrowed here after move
    |                   value moved into `b` here
    |                   move occurs because `b` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         a @ Some((ref mut b @ ref mut c, d @ ref e)) => {}
+   |                   +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:47:38
@@ -142,6 +207,11 @@ LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |                                      |   value borrowed here after move
    |                                      value moved into `d` here
    |                                      move occurs because `d` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         a @ Some((mut b @ ref mut c, ref d @ ref e)) => {}
+   |                                      +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:55:9
@@ -153,6 +223,11 @@ LL |         mut a @ Some([ref b, ref mut c]) => {}
    |         |             value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `Option<[U; 2]>` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref mut a @ Some([ref b, ref mut c]) => {}
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:61:9
@@ -163,6 +238,11 @@ LL |         a @ Some(ref b) => {}
    |         |        value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `Option<U>` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some(ref b) => {}
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:67:9
@@ -174,6 +254,11 @@ LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |         |                 value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `Option<(U, U)>` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref a @ Some((mut b @ ref mut c, d @ ref e)) => {}
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:67:19
@@ -184,6 +269,11 @@ LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |                   |       value borrowed here after move
    |                   value moved into `b` here
    |                   move occurs because `b` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         a @ Some((ref mut b @ ref mut c, d @ ref e)) => {}
+   |                   +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:67:38
@@ -194,6 +284,11 @@ LL |         a @ Some((mut b @ ref mut c, d @ ref e)) => {}
    |                                      |   value borrowed here after move
    |                                      value moved into `d` here
    |                                      move occurs because `d` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         a @ Some((mut b @ ref mut c, ref d @ ref e)) => {}
+   |                                      +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:75:9
@@ -205,6 +300,11 @@ LL |         mut a @ Some([ref b, ref mut c]) => {}
    |         |             value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `Option<[U; 2]>` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         ref mut a @ Some([ref b, ref mut c]) => {}
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:11:11
@@ -215,6 +315,11 @@ LL |     fn f1(a @ ref b: U) {}
    |           |   value borrowed here after move
    |           value moved into `a` here
    |           move occurs because `a` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     fn f1(ref a @ ref b: U) {}
+   |           +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:14:11
@@ -226,6 +331,11 @@ LL |     fn f2(mut a @ (b @ ref c, mut d @ ref e): (U, U)) {}
    |           |            value borrowed here after move
    |           value moved into `a` here
    |           move occurs because `a` has type `(U, U)` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     fn f2(ref mut a @ (b @ ref c, mut d @ ref e): (U, U)) {}
+   |           +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:14:20
@@ -236,6 +346,11 @@ LL |     fn f2(mut a @ (b @ ref c, mut d @ ref e): (U, U)) {}
    |                    |   value borrowed here after move
    |                    value moved into `b` here
    |                    move occurs because `b` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     fn f2(mut a @ (ref b @ ref c, mut d @ ref e): (U, U)) {}
+   |                    +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:14:31
@@ -246,6 +361,11 @@ LL |     fn f2(mut a @ (b @ ref c, mut d @ ref e): (U, U)) {}
    |                               |       value borrowed here after move
    |                               value moved into `d` here
    |                               move occurs because `d` has type `U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     fn f2(mut a @ (b @ ref c, ref mut d @ ref e): (U, U)) {}
+   |                               +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:19:11
@@ -257,6 +377,11 @@ LL |     fn f3(a @ [ref mut b, ref c]: [U; 2]) {}
    |           |    value borrowed here after move
    |           value moved into `a` here
    |           move occurs because `a` has type `[U; 2]` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     fn f3(ref a @ [ref mut b, ref c]: [U; 2]) {}
+   |           +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:24:9
@@ -269,8 +394,8 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (U, U);
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let a @ (mut b @ ref mut c, ref d @ ref e) = (U, U);
-   |                                 +++
+LL |     let ref a @ (mut b @ ref mut c, ref d @ ref e) = (U, U);
+   |         +++                         +++
 
 error[E0382]: use of partially moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:33:9
@@ -283,8 +408,8 @@ LL |     let a @ (mut b @ ref mut c, d @ ref e) = (u(), u());
    = note: partial move occurs because value has type `U`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let a @ (mut b @ ref mut c, ref d @ ref e) = (u(), u());
-   |                                 +++
+LL |     let ref a @ (mut b @ ref mut c, ref d @ ref e) = (u(), u());
+   |         +++                         +++
 
 error[E0382]: use of moved value
   --> $DIR/borrowck-pat-by-move-and-ref-inverse.rs:47:38
diff --git a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
index 384a57b2ee092..ad4ce7952ca74 100644
--- a/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
+++ b/src/test/ui/pattern/bindings-after-at/borrowck-pat-ref-mut-twice.stderr
@@ -97,6 +97,11 @@ LL |     let a @ (ref mut b, ref mut c) = (U, U);
    |         |    value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `(U, U)` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ (ref mut b, ref mut c) = (U, U);
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-ref-mut-twice.rs:67:9
@@ -109,6 +114,11 @@ LL |     let a @ (b, [c, d]) = &mut val; // Same as ^--
    |         |    value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `&mut (U, [U; 2])` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ (b, [c, d]) = &mut val; // Same as ^--
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-ref-mut-twice.rs:70:9
@@ -119,6 +129,11 @@ LL |     let a @ &mut ref mut b = &mut U;
    |         |        value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `&mut U` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ &mut ref mut b = &mut U;
+   |         +++
 
 error: borrow of moved value
   --> $DIR/borrowck-pat-ref-mut-twice.rs:72:9
@@ -130,6 +145,11 @@ LL |     let a @ &mut (ref mut b, ref mut c) = &mut (U, U);
    |         |         value borrowed here after move
    |         value moved into `a` here
    |         move occurs because `a` has type `&mut (U, U)` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref a @ &mut (ref mut b, ref mut c) = &mut (U, U);
+   |         +++
 
 error: cannot borrow value as mutable more than once at a time
   --> $DIR/borrowck-pat-ref-mut-twice.rs:76:9
diff --git a/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr b/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr
index 4ea3dfefb77a3..e0e623fa544f7 100644
--- a/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr
+++ b/src/test/ui/pattern/bindings-after-at/copy-and-move-mixed.stderr
@@ -9,8 +9,8 @@ LL |     let a @ NC(b, c @ NC(d, e)) = NC(C, NC(C, C));
    = note: partial move occurs because value has type `NC<C, C>`, which does not implement the `Copy` trait
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let a @ NC(b, ref c @ NC(d, e)) = NC(C, NC(C, C));
-   |                   +++
+LL |     let ref a @ NC(b, ref c @ NC(d, e)) = NC(C, NC(C, C));
+   |         +++           +++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr b/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
index 43e4b6990d2a2..638bdd6db7606 100644
--- a/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
+++ b/src/test/ui/pattern/bindings-after-at/default-binding-modes-both-sides-independent.stderr
@@ -34,6 +34,11 @@ LL |         Ok(ref a @ b) | Err(b @ ref a) => {
    |                             |   value borrowed here after move
    |                             value moved into `b` here
    |                             move occurs because `b` has type `NotCopy` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |         Ok(ref a @ b) | Err(ref b @ ref a) => {
+   |                             +++
 
 error: cannot move out of value because it is borrowed
   --> $DIR/default-binding-modes-both-sides-independent.rs:42:9
diff --git a/src/test/ui/suggestions/ref-pattern-binding.fixed b/src/test/ui/suggestions/ref-pattern-binding.fixed
new file mode 100644
index 0000000000000..c36040eeca301
--- /dev/null
+++ b/src/test/ui/suggestions/ref-pattern-binding.fixed
@@ -0,0 +1,19 @@
+// run-rustfix
+#![allow(unused)]
+
+struct S {
+    f: String,
+}
+
+fn main() {
+    let ref _moved @ ref _from = String::from("foo"); //~ ERROR
+    let ref _moved @ ref _from = String::from("foo"); //~ ERROR
+    let ref _moved @ ref _from = String::from("foo"); //~ ERROR
+    //~^ ERROR
+    let ref _moved @ ref _from = String::from("foo"); // ok
+    let ref _moved @ S { ref f } = S { f: String::from("foo") }; //~ ERROR
+    let ref _moved @ S { ref f } = S { f: String::from("foo") }; //~ ERROR
+    //~^ ERROR
+    let ref _moved @ S { ref f } = S { f: String::from("foo") }; // ok
+    let ref _moved @ S { ref f } = S { f: String::from("foo") }; //~ ERROR
+}
diff --git a/src/test/ui/suggestions/ref-pattern-binding.rs b/src/test/ui/suggestions/ref-pattern-binding.rs
new file mode 100644
index 0000000000000..c0d4feb033098
--- /dev/null
+++ b/src/test/ui/suggestions/ref-pattern-binding.rs
@@ -0,0 +1,19 @@
+// run-rustfix
+#![allow(unused)]
+
+struct S {
+    f: String,
+}
+
+fn main() {
+    let _moved @ _from = String::from("foo"); //~ ERROR
+    let _moved @ ref _from = String::from("foo"); //~ ERROR
+    let ref _moved @ _from = String::from("foo"); //~ ERROR
+    //~^ ERROR
+    let ref _moved @ ref _from = String::from("foo"); // ok
+    let _moved @ S { f } = S { f: String::from("foo") }; //~ ERROR
+    let ref _moved @ S { f } = S { f: String::from("foo") }; //~ ERROR
+    //~^ ERROR
+    let ref _moved @ S { ref f } = S { f: String::from("foo") }; // ok
+    let _moved @ S { ref f } = S { f: String::from("foo") }; //~ ERROR
+}
diff --git a/src/test/ui/suggestions/ref-pattern-binding.stderr b/src/test/ui/suggestions/ref-pattern-binding.stderr
new file mode 100644
index 0000000000000..10447ba7089ca
--- /dev/null
+++ b/src/test/ui/suggestions/ref-pattern-binding.stderr
@@ -0,0 +1,107 @@
+error: borrow of moved value
+  --> $DIR/ref-pattern-binding.rs:10:9
+   |
+LL |     let _moved @ ref _from = String::from("foo");
+   |         ------^^^---------
+   |         |        |
+   |         |        value borrowed here after move
+   |         value moved into `_moved` here
+   |         move occurs because `_moved` has type `String` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref _moved @ ref _from = String::from("foo");
+   |         +++
+
+error: cannot move out of value because it is borrowed
+  --> $DIR/ref-pattern-binding.rs:11:9
+   |
+LL |     let ref _moved @ _from = String::from("foo");
+   |         ----------^^^-----
+   |         |            |
+   |         |            value moved into `_from` here
+   |         value borrowed, by `_moved`, here
+
+error: cannot move out of value because it is borrowed
+  --> $DIR/ref-pattern-binding.rs:15:9
+   |
+LL |     let ref _moved @ S { f } = S { f: String::from("foo") };
+   |         ----------^^^^^^^-^^
+   |         |                |
+   |         |                value moved into `f` here
+   |         value borrowed, by `_moved`, here
+
+error: borrow of moved value
+  --> $DIR/ref-pattern-binding.rs:18:9
+   |
+LL |     let _moved @ S { ref f } = S { f: String::from("foo") };
+   |         ------^^^^^^^-----^^
+   |         |            |
+   |         |            value borrowed here after move
+   |         value moved into `_moved` here
+   |         move occurs because `_moved` has type `S` which does not implement the `Copy` trait
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref _moved @ S { ref f } = S { f: String::from("foo") };
+   |         +++
+
+error[E0382]: use of moved value
+  --> $DIR/ref-pattern-binding.rs:9:9
+   |
+LL |     let _moved @ _from = String::from("foo");
+   |         ^^^^^^   -----   ------------------- move occurs because value has type `String`, which does not implement the `Copy` trait
+   |         |        |
+   |         |        value moved here
+   |         value used here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref _moved @ ref _from = String::from("foo");
+   |         +++          +++
+
+error[E0382]: borrow of moved value
+  --> $DIR/ref-pattern-binding.rs:11:9
+   |
+LL |     let ref _moved @ _from = String::from("foo");
+   |         ^^^^^^^^^^   -----   ------------------- move occurs because value has type `String`, which does not implement the `Copy` trait
+   |         |            |
+   |         |            value moved here
+   |         value borrowed here after move
+   |
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref _moved @ ref _from = String::from("foo");
+   |                      +++
+
+error[E0382]: use of partially moved value
+  --> $DIR/ref-pattern-binding.rs:14:9
+   |
+LL |     let _moved @ S { f } = S { f: String::from("foo") };
+   |         ^^^^^^       - value partially moved here
+   |         |
+   |         value used here after partial move
+   |
+   = note: partial move occurs because value has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref _moved @ S { ref f } = S { f: String::from("foo") };
+   |         +++              +++
+
+error[E0382]: borrow of partially moved value
+  --> $DIR/ref-pattern-binding.rs:15:9
+   |
+LL |     let ref _moved @ S { f } = S { f: String::from("foo") };
+   |         ^^^^^^^^^^       - value partially moved here
+   |         |
+   |         value borrowed here after partial move
+   |
+   = note: partial move occurs because value has type `String`, which does not implement the `Copy` trait
+help: borrow this binding in the pattern to avoid moving the value
+   |
+LL |     let ref _moved @ S { ref f } = S { f: String::from("foo") };
+   |                          +++
+
+error: aborting due to 8 previous errors
+
+For more information about this error, try `rustc --explain E0382`.
diff --git a/src/test/ui/track-diagnostics/track2.stderr b/src/test/ui/track-diagnostics/track2.stderr
index 53f20259a8e5f..fe13e5ef3f546 100644
--- a/src/test/ui/track-diagnostics/track2.stderr
+++ b/src/test/ui/track-diagnostics/track2.stderr
@@ -10,8 +10,8 @@ LL |     let _moved @ _from = String::from("foo");
    |
 help: borrow this binding in the pattern to avoid moving the value
    |
-LL |     let _moved @ ref _from = String::from("foo");
-   |                  +++
+LL |     let ref _moved @ ref _from = String::from("foo");
+   |         +++          +++
 
 error: aborting due to previous error
 

From 0da4c44190d657e7c28f077f99b2fa03f06e1649 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Tue, 15 Nov 2022 19:43:33 -0800
Subject: [PATCH 14/15] Account for closures

---
 .../rustc_borrowck/src/diagnostics/conflict_errors.rs     | 6 ++++--
 compiler/rustc_borrowck/src/diagnostics/mod.rs            | 8 +++++---
 src/test/ui/closure_context/issue-42065.stderr            | 4 ----
 src/test/ui/moves/borrow-closures-instead-of-move.stderr  | 7 -------
 .../unboxed-closures-infer-fnonce-call-twice.stderr       | 4 ----
 .../unboxed-closures-infer-fnonce-move-call-twice.stderr  | 4 ----
 6 files changed, 9 insertions(+), 24 deletions(-)

diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 70ad3b62805fa..04bf4e04736fd 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -167,7 +167,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 );
             }
 
-            self.add_moved_or_invoked_closure_note(location, used_place, &mut err);
+            let closure = self.add_moved_or_invoked_closure_note(location, used_place, &mut err);
 
             let mut is_loop_move = false;
             let mut in_pattern = false;
@@ -193,7 +193,9 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 }
 
                 if !seen_spans.contains(&move_span) {
-                    self.suggest_ref_or_clone(mpi, move_span, &mut err, &mut in_pattern);
+                    if !closure {
+                        self.suggest_ref_or_clone(mpi, move_span, &mut err, &mut in_pattern);
+                    }
 
                     self.explain_captures(
                         &mut err,
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index 4c3216d98783b..c500cbc49e4a3 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -70,7 +70,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         location: Location,
         place: PlaceRef<'tcx>,
         diag: &mut Diagnostic,
-    ) {
+    ) -> bool {
         debug!("add_moved_or_invoked_closure_note: location={:?} place={:?}", location, place);
         let mut target = place.local_or_deref_local();
         for stmt in &self.body[location.block].statements[location.statement_index..] {
@@ -106,7 +106,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                         {
                             place.local_or_deref_local().unwrap()
                         }
-                        _ => return,
+                        _ => return false,
                     };
 
                     debug!("add_moved_or_invoked_closure_note: closure={:?}", closure);
@@ -125,7 +125,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                                     ty::place_to_string_for_capture(self.infcx.tcx, hir_place)
                                 ),
                             );
-                            return;
+                            return true;
                         }
                     }
                 }
@@ -149,9 +149,11 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                             ty::place_to_string_for_capture(self.infcx.tcx, hir_place)
                         ),
                     );
+                    return true;
                 }
             }
         }
+        false
     }
 
     /// End-user visible description of `place` if one can be found.
diff --git a/src/test/ui/closure_context/issue-42065.stderr b/src/test/ui/closure_context/issue-42065.stderr
index 4e436ca7c03f5..896bb6dc6bee8 100644
--- a/src/test/ui/closure_context/issue-42065.stderr
+++ b/src/test/ui/closure_context/issue-42065.stderr
@@ -16,10 +16,6 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     debug_dump_dict();
    |     ^^^^^^^^^^^^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     debug_dump_dict.clone()();
-   |                    ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/moves/borrow-closures-instead-of-move.stderr b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
index fbeeaf646e1ee..9a84ddef7e64e 100644
--- a/src/test/ui/moves/borrow-closures-instead-of-move.stderr
+++ b/src/test/ui/moves/borrow-closures-instead-of-move.stderr
@@ -58,13 +58,6 @@ note: closure cannot be moved more than once as it is not `Copy` due to moving t
    |
 LL |         x += 1;
    |         ^
-note: consider changing this parameter type in function `takes_fnonce` to borrow instead if owning the value isn't necessary
-  --> $DIR/borrow-closures-instead-of-move.rs:34:20
-   |
-LL | fn takes_fnonce(_: impl FnOnce()) {}
-   |    ------------    ^^^^^^^^^^^^^ this parameter takes ownership of the value
-   |    |
-   |    in this function
 help: consider mutably borrowing `closure`
    |
 LL |     takes_fnonce(&mut closure);
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr
index 3175d2942d5a7..ab6f06518467c 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-call-twice.stderr
@@ -16,10 +16,6 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     tick();
    |     ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     tick.clone()();
-   |         ++++++++
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr
index ffeafb10fda2c..8d70a2b17602b 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-fnonce-move-call-twice.stderr
@@ -16,10 +16,6 @@ note: this value implements `FnOnce`, which causes it to be moved when called
    |
 LL |     tick();
    |     ^^^^
-help: consider cloning the value if the performance cost is acceptable
-   |
-LL |     tick.clone()();
-   |         ++++++++
 
 error: aborting due to previous error
 

From 78b8d126db36fb031915e67a6498efd29b3438a0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Wed, 23 Nov 2022 12:15:22 -0800
Subject: [PATCH 15/15] Fix rebase

---
 compiler/rustc_ast_lowering/src/expr.rs                    | 2 +-
 compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 6215d9af3702b..3c217c0249aba 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -136,7 +136,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         this.lower_block(body, false),
                         this.lower_label(*opt_label),
                         hir::LoopSource::Loop,
-                        this.lower_span(span),
+                        this.lower_span(*span),
                     )
                 }),
                 ExprKind::TryBlock(body) => self.lower_expr_try_block(body),
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 04bf4e04736fd..5c645c66cd71c 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -740,8 +740,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         if infcx
             .type_implements_trait(
                 tcx.lang_items().clone_trait().unwrap(),
-                tcx.erase_regions(ty),
-                ty::List::empty(),
+                [tcx.erase_regions(ty)],
                 self.param_env,
             )
             .must_apply_modulo_regions()