Auto merge of #6931 - Jarcho:needless_borrow, r=phansch,flip1995

Fix all occurences `needless_borrow` internally

The bug that got 'needless_borrow' moved into the nursery was fixed two years ago in d4370f8.

This did trigger over a thousand times internally, so that's all the other changes. I vetted most of them, but there's a lot The only interesting change is to the lint list. `declare_tool_lint` already makes a reference, so there's no need to take a reference to the lints.

changelog: None

clippy_dev/src/fmt.rs

@@ -68,7 +68,7 @@ pub fn run(check: bool, verbose: bool) {
                 continue;
             }
 
-            success &= rustfmt(context, &path)?;
+            success &= rustfmt(context, path)?;
         }
 
         Ok(success)

clippy_dev/src/lib.rs

@@ -101,7 +101,7 @@ impl Lint {
 #[must_use]
 pub fn gen_lint_group_list<'a>(lints: impl Iterator<Item = &'a Lint>) -> Vec<String> {
     lints
-        .map(|l| format!("        LintId::of(&{}::{}),", l.module, l.name.to_uppercase()))
+        .map(|l| format!("        LintId::of({}::{}),", l.module, l.name.to_uppercase()))
         .sorted()
         .collect::<Vec<String>>()
 }
@@ -154,17 +154,17 @@ pub fn gen_register_lint_list<'a>(
     let header = "    store.register_lints(&[".to_string();
     let footer = "    ]);".to_string();
     let internal_lints = internal_lints
-        .sorted_by_key(|l| format!("        &{}::{},", l.module, l.name.to_uppercase()))
+        .sorted_by_key(|l| format!("        {}::{},", l.module, l.name.to_uppercase()))
         .map(|l| {
             format!(
-                "        #[cfg(feature = \"internal-lints\")]\n        &{}::{},",
+                "        #[cfg(feature = \"internal-lints\")]\n        {}::{},",
                 l.module,
                 l.name.to_uppercase()
             )
         });
     let other_lints = usable_lints
-        .sorted_by_key(|l| format!("        &{}::{},", l.module, l.name.to_uppercase()))
-        .map(|l| format!("        &{}::{},", l.module, l.name.to_uppercase()))
+        .sorted_by_key(|l| format!("        {}::{},", l.module, l.name.to_uppercase()))
+        .map(|l| format!("        {}::{},", l.module, l.name.to_uppercase()))
         .sorted();
     let mut lint_list = vec![header];
     lint_list.extend(internal_lints);
@@ -550,9 +550,9 @@ fn test_gen_lint_group_list() {
         Lint::new("internal", "internal_style", "abc", None, "module_name"),
     ];
     let expected = vec![
-        "        LintId::of(&module_name::ABC),".to_string(),
-        "        LintId::of(&module_name::INTERNAL),".to_string(),
-        "        LintId::of(&module_name::SHOULD_ASSERT_EQ),".to_string(),
+        "        LintId::of(module_name::ABC),".to_string(),
+        "        LintId::of(module_name::INTERNAL),".to_string(),
+        "        LintId::of(module_name::SHOULD_ASSERT_EQ),".to_string(),
     ];
     assert_eq!(expected, gen_lint_group_list(lints.iter()));
 }

clippy_lints/src/absurd_extreme_comparisons.rs

@@ -44,7 +44,7 @@ declare_lint_pass!(AbsurdExtremeComparisons => [ABSURD_EXTREME_COMPARISONS]);
 
 impl<'tcx> LateLintPass<'tcx> for AbsurdExtremeComparisons {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if let ExprKind::Binary(ref cmp, ref lhs, ref rhs) = expr.kind {
+        if let ExprKind::Binary(ref cmp, lhs, rhs) = expr.kind {
             if let Some((culprit, result)) = detect_absurd_comparison(cx, cmp.node, lhs, rhs) {
                 if !expr.span.from_expansion() {
                     let msg = "this comparison involving the minimum or maximum element for this \
@@ -95,7 +95,7 @@ enum AbsurdComparisonResult {
 }
 
 fn is_cast_between_fixed_and_target<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool {
-    if let ExprKind::Cast(ref cast_exp, _) = expr.kind {
+    if let ExprKind::Cast(cast_exp, _) = expr.kind {
         let precast_ty = cx.typeck_results().expr_ty(cast_exp);
         let cast_ty = cx.typeck_results().expr_ty(expr);
 

clippy_lints/src/assertions_on_constants.rs

@@ -71,7 +71,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
                 return;
             }
             if_chain! {
-                if let ExprKind::Unary(_, ref lit) = e.kind;
+                if let ExprKind::Unary(_, lit) = e.kind;
                 if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), lit);
                 if is_true;
                 then {
@@ -82,7 +82,7 @@ impl<'tcx> LateLintPass<'tcx> for AssertionsOnConstants {
             if assert_span.from_expansion() {
                 return;
             }
-            if let Some(assert_match) = match_assert_with_message(&cx, e) {
+            if let Some(assert_match) = match_assert_with_message(cx, e) {
                 match assert_match {
                     // matched assert but not message
                     AssertKind::WithoutMessage(false) => lint_false_without_message(),
@@ -113,17 +113,17 @@ enum AssertKind {
 /// where `message` is any expression and `c` is a constant bool.
 fn match_assert_with_message<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<AssertKind> {
     if_chain! {
-        if let ExprKind::If(ref cond, ref then, _) = expr.kind;
-        if let ExprKind::Unary(UnOp::Not, ref expr) = cond.kind;
+        if let ExprKind::If(cond, then, _) = expr.kind;
+        if let ExprKind::Unary(UnOp::Not, expr) = cond.kind;
         // bind the first argument of the `assert!` macro
         if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.typeck_results(), expr);
         // block
-        if let ExprKind::Block(ref block, _) = then.kind;
+        if let ExprKind::Block(block, _) = then.kind;
         if block.stmts.is_empty();
         if let Some(block_expr) = &block.expr;
         // inner block is optional. unwrap it if it exists, or use the expression as is otherwise.
         if let Some(begin_panic_call) = match block_expr.kind {
-            ExprKind::Block(ref inner_block, _) => &inner_block.expr,
+            ExprKind::Block(inner_block, _) => &inner_block.expr,
             _ => &block.expr,
         };
         // function call

clippy_lints/src/atomic_ordering.rs

@@ -85,7 +85,7 @@ fn match_ordering_def_path(cx: &LateContext<'_>, did: DefId, orderings: &[&str])
 
 fn check_atomic_load_store(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if_chain! {
-        if let ExprKind::MethodCall(ref method_path, _, args, _) = &expr.kind;
+        if let ExprKind::MethodCall(method_path, _, args, _) = &expr.kind;
         let method = method_path.ident.name.as_str();
         if type_is_atomic(cx, &args[0]);
         if method == "load" || method == "store";
@@ -120,7 +120,7 @@ fn check_atomic_load_store(cx: &LateContext<'_>, expr: &Expr<'_>) {
 
 fn check_memory_fence(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if_chain! {
-        if let ExprKind::Call(ref func, ref args) = expr.kind;
+        if let ExprKind::Call(func, args) = expr.kind;
         if let ExprKind::Path(ref func_qpath) = func.kind;
         if let Some(def_id) = cx.qpath_res(func_qpath, func.hir_id).opt_def_id();
         if ["fence", "compiler_fence"]
@@ -152,7 +152,7 @@ fn opt_ordering_defid(cx: &LateContext<'_>, ord_arg: &Expr<'_>) -> Option<DefId>
 
 fn check_atomic_compare_exchange(cx: &LateContext<'_>, expr: &Expr<'_>) {
     if_chain! {
-        if let ExprKind::MethodCall(ref method_path, _, args, _) = &expr.kind;
+        if let ExprKind::MethodCall(method_path, _, args, _) = &expr.kind;
         let method = method_path.ident.name.as_str();
         if type_is_atomic(cx, &args[0]);
         if method == "compare_exchange" || method == "compare_exchange_weak" || method == "fetch_update";

clippy_lints/src/attrs.rs

@@ -602,7 +602,7 @@ fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) {
             if let NestedMetaItem::MetaItem(meta) = item {
                 match &meta.kind {
                     MetaItemKind::List(list) => {
-                        mismatched.extend(find_mismatched_target_os(&list));
+                        mismatched.extend(find_mismatched_target_os(list));
                     },
                     MetaItemKind::Word => {
                         if_chain! {
@@ -629,7 +629,7 @@ fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) {
         then {
             let mess = "operating system used in target family position";
 
-            span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, &mess, |diag| {
+            span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, mess, |diag| {
                 // Avoid showing the unix suggestion multiple times in case
                 // we have more than one mismatch for unix-like systems
                 let mut unix_suggested = false;

clippy_lints/src/await_holding_invalid.rs

@@ -101,7 +101,7 @@ impl LateLintPass<'_> for AwaitHolding {
             let typeck_results = cx.tcx.typeck_body(body_id);
             check_interior_types(
                 cx,
-                &typeck_results.generator_interior_types.as_ref().skip_binder(),
+                typeck_results.generator_interior_types.as_ref().skip_binder(),
                 body.value.span,
             );
         }

clippy_lints/src/bytecount.rs

@@ -38,17 +38,17 @@ declare_lint_pass!(ByteCount => [NAIVE_BYTECOUNT]);
 impl<'tcx> LateLintPass<'tcx> for ByteCount {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
         if_chain! {
-            if let ExprKind::MethodCall(ref count, _, ref count_args, _) = expr.kind;
+            if let ExprKind::MethodCall(count, _, count_args, _) = expr.kind;
             if count.ident.name == sym!(count);
             if count_args.len() == 1;
-            if let ExprKind::MethodCall(ref filter, _, ref filter_args, _) = count_args[0].kind;
+            if let ExprKind::MethodCall(filter, _, filter_args, _) = count_args[0].kind;
             if filter.ident.name == sym!(filter);
             if filter_args.len() == 2;
             if let ExprKind::Closure(_, _, body_id, _, _) = filter_args[1].kind;
             let body = cx.tcx.hir().body(body_id);
             if body.params.len() == 1;
-            if let Some(argname) = get_pat_name(&body.params[0].pat);
-            if let ExprKind::Binary(ref op, ref l, ref r) = body.value.kind;
+            if let Some(argname) = get_pat_name(body.params[0].pat);
+            if let ExprKind::Binary(ref op, l, r) = body.value.kind;
             if op.node == BinOpKind::Eq;
             if match_type(cx,
                        cx.typeck_results().expr_ty(&filter_args[0]).peel_refs(),
@@ -64,7 +64,7 @@ impl<'tcx> LateLintPass<'tcx> for ByteCount {
                 if ty::Uint(UintTy::U8) != *cx.typeck_results().expr_ty(needle).peel_refs().kind() {
                     return;
                 }
-                let haystack = if let ExprKind::MethodCall(ref path, _, ref args, _) =
+                let haystack = if let ExprKind::MethodCall(path, _, args, _) =
                         filter_args[0].kind {
                     let p = path.ident.name;
                     if (p == sym::iter || p == sym!(iter_mut)) && args.len() == 1 {
@@ -98,10 +98,10 @@ fn check_arg(name: Symbol, arg: Symbol, needle: &Expr<'_>) -> bool {
 
 fn get_path_name(expr: &Expr<'_>) -> Option<Symbol> {
     match expr.kind {
-        ExprKind::Box(ref e) | ExprKind::AddrOf(BorrowKind::Ref, _, ref e) | ExprKind::Unary(UnOp::Deref, ref e) => {
+        ExprKind::Box(e) | ExprKind::AddrOf(BorrowKind::Ref, _, e) | ExprKind::Unary(UnOp::Deref, e) => {
             get_path_name(e)
         },
-        ExprKind::Block(ref b, _) => {
+        ExprKind::Block(b, _) => {
             if b.stmts.is_empty() {
                 b.expr.as_ref().and_then(|p| get_path_name(p))
             } else {

clippy_lints/src/casts/cast_ptr_alignment.rs

@@ -10,7 +10,7 @@ use rustc_target::abi::LayoutOf;
 use super::CAST_PTR_ALIGNMENT;
 
 pub(super) fn check(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-    if let ExprKind::Cast(ref cast_expr, cast_to) = expr.kind {
+    if let ExprKind::Cast(cast_expr, cast_to) = expr.kind {
         if is_hir_ty_cfg_dependant(cx, cast_to) {
             return;
         }

clippy_lints/src/casts/cast_sign_loss.rs

@@ -30,7 +30,7 @@ fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast
             }
 
             // Don't lint for positive constants.
-            let const_val = constant(cx, &cx.typeck_results(), cast_op);
+            let const_val = constant(cx, cx.typeck_results(), cast_op);
             if_chain! {
                 if let Some((Constant::Int(n), _)) = const_val;
                 if let ty::Int(ity) = *cast_from.kind();
@@ -41,14 +41,14 @@ fn should_lint(cx: &LateContext<'_>, cast_op: &Expr<'_>, cast_from: Ty<'_>, cast
             }
 
             // Don't lint for the result of methods that always return non-negative values.
-            if let ExprKind::MethodCall(ref path, _, _, _) = cast_op.kind {
+            if let ExprKind::MethodCall(path, _, _, _) = cast_op.kind {
                 let mut method_name = path.ident.name.as_str();
                 let allowed_methods = ["abs", "checked_abs", "rem_euclid", "checked_rem_euclid"];
 
                 if_chain! {
                     if method_name == "unwrap";
                     if let Some(arglist) = method_chain_args(cast_op, &["unwrap"]);
-                    if let ExprKind::MethodCall(ref inner_path, _, _, _) = &arglist[0][0].kind;
+                    if let ExprKind::MethodCall(inner_path, _, _, _) = &arglist[0][0].kind;
                     then {
                         method_name = inner_path.ident.name.as_str();
                     }

clippy_lints/src/casts/mod.rs

@@ -372,7 +372,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts {
             return;
         }
 
-        if let ExprKind::Cast(ref cast_expr, cast_to) = expr.kind {
+        if let ExprKind::Cast(cast_expr, cast_to) = expr.kind {
             if is_hir_ty_cfg_dependant(cx, cast_to) {
                 return;
             }

clippy_lints/src/checked_conversions.rs

@@ -64,7 +64,7 @@ impl<'tcx> LateLintPass<'tcx> for CheckedConversions {
 
         let result = if_chain! {
             if !in_external_macro(cx.sess(), item.span);
-            if let ExprKind::Binary(op, ref left, ref right) = &item.kind;
+            if let ExprKind::Binary(op, left, right) = &item.kind;
 
             then {
                 match op.node {
@@ -200,7 +200,7 @@ impl ConversionType {
 /// Check for `expr <= (to_type::MAX as from_type)`
 fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
     if_chain! {
-         if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind;
+         if let ExprKind::Binary(ref op, left, right) = &expr.kind;
          if let Some((candidate, check)) = normalize_le_ge(op, left, right);
          if let Some((from, to)) = get_types_from_cast(check, INTS, "max_value", "MAX");
 
@@ -219,7 +219,7 @@ fn check_lower_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
     }
 
     // First of we need a binary containing the expression & the cast
-    if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind {
+    if let ExprKind::Binary(ref op, left, right) = &expr.kind {
         normalize_le_ge(op, right, left).and_then(|(l, r)| check_function(l, r))
     } else {
         None
@@ -260,7 +260,7 @@ fn get_types_from_cast<'a>(
     // or `to_type::MAX as from_type`
     let call_from_cast: Option<(&Expr<'_>, &str)> = if_chain! {
         // to_type::max_value(), from_type
-        if let ExprKind::Cast(ref limit, ref from_type) = &expr.kind;
+        if let ExprKind::Cast(limit, from_type) = &expr.kind;
         if let TyKind::Path(ref from_type_path) = &from_type.kind;
         if let Some(from_sym) = int_ty_to_sym(from_type_path);
 
@@ -275,7 +275,7 @@ fn get_types_from_cast<'a>(
     let limit_from: Option<(&Expr<'_>, &str)> = call_from_cast.or_else(|| {
         if_chain! {
             // `from_type::from, to_type::max_value()`
-            if let ExprKind::Call(ref from_func, ref args) = &expr.kind;
+            if let ExprKind::Call(from_func, args) = &expr.kind;
             // `to_type::max_value()`
             if args.len() == 1;
             if let limit = &args[0];
@@ -317,9 +317,9 @@ fn get_types_from_cast<'a>(
 /// Gets the type which implements the called function
 fn get_implementing_type<'a>(path: &QPath<'_>, candidates: &'a [&str], function: &str) -> Option<&'a str> {
     if_chain! {
-        if let QPath::TypeRelative(ref ty, ref path) = &path;
+        if let QPath::TypeRelative(ty, path) = &path;
         if path.ident.name.as_str() == function;
-        if let TyKind::Path(QPath::Resolved(None, ref tp)) = &ty.kind;
+        if let TyKind::Path(QPath::Resolved(None, tp)) = &ty.kind;
         if let [int] = &*tp.segments;
         then {
             let name = &int.ident.name.as_str();
@@ -333,7 +333,7 @@ fn get_implementing_type<'a>(path: &QPath<'_>, candidates: &'a [&str], function:
 /// Gets the type as a string, if it is a supported integer
 fn int_ty_to_sym<'tcx>(path: &QPath<'_>) -> Option<&'tcx str> {
     if_chain! {
-        if let QPath::Resolved(_, ref path) = *path;
+        if let QPath::Resolved(_, path) = *path;
         if let [ty] = &*path.segments;
         then {
             let name = &ty.ident.name.as_str();

clippy_lints/src/cognitive_complexity.rs

@@ -152,7 +152,7 @@ impl<'tcx> Visitor<'tcx> for CcHelper {
             ExprKind::If(_, _, _) => {
                 self.cc += 1;
             },
-            ExprKind::Match(_, ref arms, _) => {
+            ExprKind::Match(_, arms, _) => {
                 if arms.len() > 1 {
                     self.cc += 1;
                 }

clippy_lints/src/comparison_chain.rs

@@ -71,10 +71,8 @@ impl<'tcx> LateLintPass<'tcx> for ComparisonChain {
         }
 
         for cond in conds.windows(2) {
-            if let (
-                &ExprKind::Binary(ref kind1, ref lhs1, ref rhs1),
-                &ExprKind::Binary(ref kind2, ref lhs2, ref rhs2),
-            ) = (&cond[0].kind, &cond[1].kind)
+            if let (&ExprKind::Binary(ref kind1, lhs1, rhs1), &ExprKind::Binary(ref kind2, lhs2, rhs2)) =
+                (&cond[0].kind, &cond[1].kind)
             {
                 if !kind_is_cmp(kind1.node) || !kind_is_cmp(kind2.node) {
                     return;

clippy_lints/src/copies.rs

@@ -160,7 +160,7 @@ impl<'tcx> LateLintPass<'tcx> for CopyAndPaste {
             if let ExprKind::If(_, _, _) = expr.kind {
                 // skip ifs directly in else, it will be checked in the parent if
                 if let Some(&Expr {
-                    kind: ExprKind::If(_, _, Some(ref else_expr)),
+                    kind: ExprKind::If(_, _, Some(else_expr)),
                     ..
                 }) = get_parent_expr(cx, expr)
                 {
@@ -247,7 +247,7 @@ fn lint_same_then_else<'tcx>(
 
             for value in &end_walker.uses {
                 // Well we can't move this and all prev statements. So reset
-                if block_defs.contains(&value) {
+                if block_defs.contains(value) {
                     moved_start = Some(index + 1);
                     end_walker.defs.drain().for_each(|x| {
                         block_defs.insert(x);
@@ -555,7 +555,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UsedValueFinderVisitor<'a, 'tcx> {
     }
 
     fn visit_qpath(&mut self, qpath: &'tcx rustc_hir::QPath<'tcx>, id: HirId, _span: rustc_span::Span) {
-        if let rustc_hir::QPath::Resolved(_, ref path) = *qpath {
+        if let rustc_hir::QPath::Resolved(_, path) = *qpath {
             if path.segments.len() == 1 {
                 if let rustc_hir::def::Res::Local(var) = self.cx.qpath_res(qpath, id) {
                     self.uses.insert(var);

clippy_lints/src/create_dir.rs

@@ -33,7 +33,7 @@ declare_lint_pass!(CreateDir => [CREATE_DIR]);
 impl LateLintPass<'_> for CreateDir {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
         if_chain! {
-            if let ExprKind::Call(ref func, ref args) = expr.kind;
+            if let ExprKind::Call(func, args) = expr.kind;
             if let ExprKind::Path(ref path) = func.kind;
             if let Some(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id();
             if match_def_path(cx, def_id, &paths::STD_FS_CREATE_DIR);