Merge commit '6ed6f1e6a1a8f414ba7e6d9b8222e7e5a1686e42' into clippyup

7 files changed, 268 insertions, 42 deletions

diff --git a/src/tools/clippy/clippy_utils/Cargo.toml b/src/tools/clippy/clippy_utils/Cargo.toml
index 9c01badb04c..9e07f140cf1 100644
--- a/src/tools/clippy/clippy_utils/Cargo.toml
+++ b/src/tools/clippy/clippy_utils/Cargo.toml
@@ -17,3 +17,7 @@ rustc-semver="1.1.0"
 
 [features]
 internal-lints = []
+
+[package.metadata.rust-analyzer]
+# This crate uses #[feature(rustc_private)]
+rustc_private = true
diff --git a/src/tools/clippy/clippy_utils/src/camel_case.rs b/src/tools/clippy/clippy_utils/src/camel_case.rs
index ba1c01ebc9f..a6636e39137 100644
--- a/src/tools/clippy/clippy_utils/src/camel_case.rs
+++ b/src/tools/clippy/clippy_utils/src/camel_case.rs
@@ -25,11 +25,7 @@ pub fn until(s: &str) -> usize {
             return i;
         }
     }
-    if up {
-        last_i
-    } else {
-        s.len()
-    }
+    if up { last_i } else { s.len() }
 }
 
 /// Returns index of the last camel-case component of `s`.
diff --git a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
index 81cd99c0558..8013c4e4fcb 100644
--- a/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
+++ b/src/tools/clippy/clippy_utils/src/eager_or_lazy.rs
@@ -9,7 +9,7 @@
 //!  - or-fun-call
 //!  - option-if-let-else
 
-use crate::{is_ctor_or_promotable_const_function, is_type_diagnostic_item, match_type, paths};
+use crate::{is_ctor_or_promotable_const_function, is_type_diagnostic_item};
 use rustc_hir::def::{DefKind, Res};
 
 use rustc_hir::intravisit;
@@ -101,7 +101,7 @@ fn identify_some_potentially_expensive_patterns<'tcx>(cx: &LateContext<'tcx>, ex
                 ExprKind::Index(obj, _) => {
                     let ty = self.cx.typeck_results().expr_ty(obj);
                     is_type_diagnostic_item(self.cx, ty, sym::hashmap_type)
-                        || match_type(self.cx, ty, &paths::BTREEMAP)
+                        || is_type_diagnostic_item(self.cx, ty, sym::BTreeMap)
                 },
                 ExprKind::MethodCall(..) => true,
                 _ => false,
diff --git a/src/tools/clippy/clippy_utils/src/hir_utils.rs b/src/tools/clippy/clippy_utils/src/hir_utils.rs
index 81be9254cbe..e28ad27d9a6 100644
--- a/src/tools/clippy/clippy_utils/src/hir_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/hir_utils.rs
@@ -1,5 +1,5 @@
 use crate::consts::{constant_context, constant_simple};
-use crate::differing_macro_contexts;
+use crate::{differing_macro_contexts, snippet_opt};
 use rustc_ast::ast::InlineAsmTemplatePiece;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
@@ -9,6 +9,7 @@ use rustc_hir::{
     GenericArg, GenericArgs, Guard, HirId, InlineAsmOperand, Lifetime, LifetimeName, ParamName, Pat, PatKind, Path,
     PathSegment, QPath, Stmt, StmtKind, Ty, TyKind, TypeBinding,
 };
+use rustc_lexer::{tokenize, TokenKind};
 use rustc_lint::LateContext;
 use rustc_middle::ich::StableHashingContextProvider;
 use rustc_middle::ty::TypeckResults;
@@ -110,8 +111,54 @@ impl HirEqInterExpr<'_, '_, '_> {
 
     /// Checks whether two blocks are the same.
     fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
-        over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r))
-            && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
+        match (left.stmts, left.expr, right.stmts, right.expr) {
+            ([], None, [], None) => {
+                // For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
+                // expanded to nothing, or the cfg attribute was used.
+                let (left, right) = match (
+                    snippet_opt(self.inner.cx, left.span),
+                    snippet_opt(self.inner.cx, right.span),
+                ) {
+                    (Some(left), Some(right)) => (left, right),
+                    _ => return true,
+                };
+                let mut left_pos = 0;
+                let left = tokenize(&left)
+                    .map(|t| {
+                        let end = left_pos + t.len;
+                        let s = &left[left_pos..end];
+                        left_pos = end;
+                        (t, s)
+                    })
+                    .filter(|(t, _)| {
+                        !matches!(
+                            t.kind,
+                            TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
+                        )
+                    })
+                    .map(|(_, s)| s);
+                let mut right_pos = 0;
+                let right = tokenize(&right)
+                    .map(|t| {
+                        let end = right_pos + t.len;
+                        let s = &right[right_pos..end];
+                        right_pos = end;
+                        (t, s)
+                    })
+                    .filter(|(t, _)| {
+                        !matches!(
+                            t.kind,
+                            TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
+                        )
+                    })
+                    .map(|(_, s)| s);
+                left.eq(right)
+            },
+            _ => {
+                over(&left.stmts, &right.stmts, |l, r| self.eq_stmt(l, r))
+                    && both(&left.expr, &right.expr, |l, r| self.eq_expr(l, r))
+            },
+        }
     }
 
     #[allow(clippy::similar_names)]
@@ -131,7 +178,10 @@ impl HirEqInterExpr<'_, '_, '_> {
             }
         }
 
-        let is_eq = match (&reduce_exprkind(&left.kind), &reduce_exprkind(&right.kind)) {
+        let is_eq = match (
+            &reduce_exprkind(self.inner.cx, &left.kind),
+            &reduce_exprkind(self.inner.cx, &right.kind),
+        ) {
             (&ExprKind::AddrOf(lb, l_mut, ref le), &ExprKind::AddrOf(rb, r_mut, ref re)) => {
                 lb == rb && l_mut == r_mut && self.eq_expr(le, re)
             },
@@ -360,11 +410,30 @@ impl HirEqInterExpr<'_, '_, '_> {
 }
 
 /// Some simple reductions like `{ return }` => `return`
-fn reduce_exprkind<'hir>(kind: &'hir ExprKind<'hir>) -> &ExprKind<'hir> {
+fn reduce_exprkind<'hir>(cx: &LateContext<'_>, kind: &'hir ExprKind<'hir>) -> &'hir ExprKind<'hir> {
     if let ExprKind::Block(block, _) = kind {
         match (block.stmts, block.expr) {
+            // From an `if let` expression without an `else` block. The arm for the implicit wild pattern is an empty
+            // block with an empty span.
+            ([], None) if block.span.is_empty() => &ExprKind::Tup(&[]),
             // `{}` => `()`
-            ([], None) => &ExprKind::Tup(&[]),
+            ([], None) => match snippet_opt(cx, block.span) {
+                // Don't reduce if there are any tokens contained in the braces
+                Some(snip)
+                    if tokenize(&snip)
+                        .map(|t| t.kind)
+                        .filter(|t| {
+                            !matches!(
+                                t,
+                                TokenKind::LineComment { .. } | TokenKind::BlockComment { .. } | TokenKind::Whitespace
+                            )
+                        })
+                        .ne([TokenKind::OpenBrace, TokenKind::CloseBrace].iter().cloned()) =>
+                {
+                    kind
+                },
+                _ => &ExprKind::Tup(&[]),
+            },
             ([], Some(expr)) => match expr.kind {
                 // `{ return .. }` => `return ..`
                 ExprKind::Ret(..) => &expr.kind,
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index 4cd7ed5c45d..d81b89dd001 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -13,6 +13,7 @@ extern crate rustc_data_structures;
 extern crate rustc_errors;
 extern crate rustc_hir;
 extern crate rustc_infer;
+extern crate rustc_lexer;
 extern crate rustc_lint;
 extern crate rustc_middle;
 extern crate rustc_mir;
@@ -61,27 +62,29 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
 use rustc_hir::Node;
 use rustc_hir::{
-    def, Arm, Block, Body, Constness, Expr, ExprKind, FnDecl, HirId, ImplItem, ImplItemKind, Item, ItemKind,
-    MatchSource, Param, Pat, PatKind, Path, PathSegment, QPath, TraitItem, TraitItemKind, TraitRef, TyKind, Unsafety,
+    def, Arm, Block, Body, Constness, Expr, ExprKind, FnDecl, GenericArgs, HirId, Impl, ImplItem, ImplItemKind, Item,
+    ItemKind, LangItem, MatchSource, Param, Pat, PatKind, Path, PathSegment, QPath, TraitItem, TraitItemKind, TraitRef,
+    TyKind, Unsafety,
 };
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, Level, Lint, LintContext};
 use rustc_middle::hir::exports::Export;
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
-use rustc_middle::ty::{self, layout::IntegerExt, DefIdTree, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, layout::IntegerExt, DefIdTree, IntTy, Ty, TyCtxt, TypeFoldable, UintTy};
 use rustc_semver::RustcVersion;
 use rustc_session::Session;
-use rustc_span::hygiene::{ExpnKind, MacroKind};
+use rustc_span::hygiene::{self, ExpnKind, MacroKind};
 use rustc_span::source_map::original_sp;
 use rustc_span::sym;
 use rustc_span::symbol::{kw, Symbol};
-use rustc_span::{BytePos, Pos, Span, DUMMY_SP};
+use rustc_span::{BytePos, Pos, Span, SyntaxContext, DUMMY_SP};
 use rustc_target::abi::Integer;
 use rustc_trait_selection::traits::query::normalize::AtExt;
 use smallvec::SmallVec;
 
 use crate::consts::{constant, Constant};
+use std::collections::HashMap;
 
 pub fn parse_msrv(msrv: &str, sess: Option<&Session>, span: Option<Span>) -> Option<RustcVersion> {
     if let Ok(version) = RustcVersion::parse(msrv) {
@@ -229,6 +232,45 @@ pub fn is_type_lang_item(cx: &LateContext<'_>, ty: Ty<'_>, lang_item: hir::LangI
     }
 }
 
+/// Checks if the first type parameter is a lang item.
+pub fn is_ty_param_lang_item(cx: &LateContext<'_>, qpath: &QPath<'tcx>, item: LangItem) -> Option<&'tcx hir::Ty<'tcx>> {
+    let ty = get_qpath_generic_tys(qpath).next()?;
+
+    if let TyKind::Path(qpath) = &ty.kind {
+        cx.qpath_res(qpath, ty.hir_id)
+            .opt_def_id()
+            .map_or(false, |id| {
+                cx.tcx.lang_items().require(item).map_or(false, |lang_id| id == lang_id)
+            })
+            .then(|| ty)
+    } else {
+        None
+    }
+}
+
+/// Checks if the first type parameter is a diagnostic item.
+pub fn is_ty_param_diagnostic_item(
+    cx: &LateContext<'_>,
+    qpath: &QPath<'tcx>,
+    item: Symbol,
+) -> Option<&'tcx hir::Ty<'tcx>> {
+    let ty = get_qpath_generic_tys(qpath).next()?;
+
+    if let TyKind::Path(qpath) = &ty.kind {
+        cx.qpath_res(qpath, ty.hir_id)
+            .opt_def_id()
+            .map_or(false, |id| cx.tcx.is_diagnostic_item(item, id))
+            .then(|| ty)
+    } else {
+        None
+    }
+}
+
+/// Return `true` if the passed `typ` is `isize` or `usize`.
+pub fn is_isize_or_usize(typ: Ty<'_>) -> bool {
+    matches!(typ.kind(), ty::Int(IntTy::Isize) | ty::Uint(UintTy::Usize))
+}
+
 /// Checks if the method call given in `expr` belongs to the given trait.
 pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str]) -> bool {
     let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();
@@ -236,6 +278,22 @@ pub fn match_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, path: &[&str])
     trt_id.map_or(false, |trt_id| match_def_path(cx, trt_id, path))
 }
 
+/// Checks if the method call given in `expr` belongs to a trait or other container with a given
+/// diagnostic item
+pub fn is_diagnostic_assoc_item(cx: &LateContext<'_>, def_id: DefId, diag_item: Symbol) -> bool {
+    cx.tcx
+        .opt_associated_item(def_id)
+        .and_then(|associated_item| match associated_item.container {
+            ty::TraitContainer(assoc_def_id) => Some(assoc_def_id),
+            ty::ImplContainer(assoc_def_id) => match cx.tcx.type_of(assoc_def_id).kind() {
+                ty::Adt(adt, _) => Some(adt.did),
+                ty::Slice(_) => cx.tcx.get_diagnostic_item(sym::slice), // this isn't perfect but it works
+                _ => None,
+            },
+        })
+        .map_or(false, |assoc_def_id| cx.tcx.is_diagnostic_item(diag_item, assoc_def_id))
+}
+
 /// Checks if an expression references a variable of the given name.
 pub fn match_var(expr: &Expr<'_>, var: Symbol) -> bool {
     if let ExprKind::Path(QPath::Resolved(None, ref path)) = expr.kind {
@@ -254,6 +312,27 @@ pub fn last_path_segment<'tcx>(path: &QPath<'tcx>) -> &'tcx PathSegment<'tcx> {
     }
 }
 
+pub fn get_qpath_generics(path: &QPath<'tcx>) -> Option<&'tcx GenericArgs<'tcx>> {
+    match path {
+        QPath::Resolved(_, p) => p.segments.last().and_then(|s| s.args),
+        QPath::TypeRelative(_, s) => s.args,
+        QPath::LangItem(..) => None,
+    }
+}
+
+pub fn get_qpath_generic_tys(path: &QPath<'tcx>) -> impl Iterator<Item = &'tcx hir::Ty<'tcx>> {
+    get_qpath_generics(path)
+        .map_or([].as_ref(), |a| a.args)
+        .iter()
+        .filter_map(|a| {
+            if let hir::GenericArg::Type(ty) = a {
+                Some(ty)
+            } else {
+                None
+            }
+        })
+}
+
 pub fn single_segment_path<'tcx>(path: &QPath<'tcx>) -> Option<&'tcx PathSegment<'tcx>> {
     match *path {
         QPath::Resolved(_, ref path) => path.segments.get(0),
@@ -455,6 +534,18 @@ pub fn has_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
     }
 }
 
+/// Checks whether a type can be partially moved.
+pub fn can_partially_move_ty(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
+    if has_drop(cx, ty) || is_copy(cx, ty) {
+        return false;
+    }
+    match ty.kind() {
+        ty::Param(_) => false,
+        ty::Adt(def, subs) => def.all_fields().any(|f| !is_copy(cx, f.ty(cx.tcx, subs))),
+        _ => true,
+    }
+}
+
 /// Returns the method names and argument list of nested method call expressions that make up
 /// `expr`. method/span lists are sorted with the most recent call first.
 pub fn method_calls<'tcx>(
@@ -745,6 +836,35 @@ pub fn snippet_block_with_applicability<'a, T: LintContext>(
     reindent_multiline(snip, true, indent)
 }
 
+/// Same as `snippet_with_applicability`, but first walks the span up to the given context. This
+/// will result in the macro call, rather then the expansion, if the span is from a child context.
+/// If the span is not from a child context, it will be used directly instead.
+///
+/// e.g. Given the expression `&vec![]`, getting a snippet from the span for `vec![]` as a HIR node
+/// would result in `box []`. If given the context of the address of expression, this function will
+/// correctly get a snippet of `vec![]`.
+pub fn snippet_with_context(
+    cx: &LateContext<'_>,
+    span: Span,
+    outer: SyntaxContext,
+    default: &'a str,
+    applicability: &mut Applicability,
+) -> Cow<'a, str> {
+    let outer_span = hygiene::walk_chain(span, outer);
+    let span = if outer_span.ctxt() == outer {
+        outer_span
+    } else {
+        // The span is from a macro argument, and the outer context is the macro using the argument
+        if *applicability != Applicability::Unspecified {
+            *applicability = Applicability::MaybeIncorrect;
+        }
+        // TODO: get the argument span.
+        span
+    };
+
+    snippet_with_applicability(cx, span, default, applicability)
+}
+
 /// Returns a new Span that extends the original Span to the first non-whitespace char of the first
 /// line.
 ///
@@ -923,6 +1043,21 @@ pub fn get_enclosing_block<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Optio
     })
 }
 
+/// Gets the parent node if it's an impl block.
+pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> {
+    let map = tcx.hir();
+    match map.parent_iter(id).next() {
+        Some((
+            _,
+            Node::Item(Item {
+                kind: ItemKind::Impl(imp),
+                ..
+            }),
+        )) => Some(imp),
+        _ => None,
+    }
+}
+
 /// Returns the base type for HIR references and pointers.
 pub fn walk_ptrs_hir_ty<'tcx>(ty: &'tcx hir::Ty<'tcx>) -> &'tcx hir::Ty<'tcx> {
     match ty.kind {
@@ -1359,13 +1494,49 @@ pub fn match_function_call<'tcx>(
     None
 }
 
+// FIXME: Per https://doc.rust-lang.org/nightly/nightly-rustc/rustc_trait_selection/infer/at/struct.At.html#method.normalize
+// this function can be removed once the `normalizie` method does not panic when normalization does
+// not succeed
 /// Checks if `Ty` is normalizable. This function is useful
 /// to avoid crashes on `layout_of`.
 pub fn is_normalizable<'tcx>(cx: &LateContext<'tcx>, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool {
-    cx.tcx.infer_ctxt().enter(|infcx| {
+    is_normalizable_helper(cx, param_env, ty, &mut HashMap::new())
+}
+
+fn is_normalizable_helper<'tcx>(
+    cx: &LateContext<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    ty: Ty<'tcx>,
+    cache: &mut HashMap<Ty<'tcx>, bool>,
+) -> bool {
+    if let Some(&cached_result) = cache.get(ty) {
+        return cached_result;
+    }
+    // prevent recursive loops, false-negative is better than endless loop leading to stack overflow
+    cache.insert(ty, false);
+    let result = cx.tcx.infer_ctxt().enter(|infcx| {
         let cause = rustc_middle::traits::ObligationCause::dummy();
-        infcx.at(&cause, param_env).normalize(ty).is_ok()
-    })
+        if infcx.at(&cause, param_env).normalize(ty).is_ok() {
+            match ty.kind() {
+                ty::Adt(def, substs) => def.variants.iter().all(|variant| {
+                    variant
+                        .fields
+                        .iter()
+                        .all(|field| is_normalizable_helper(cx, param_env, field.ty(cx.tcx, substs), cache))
+                }),
+                _ => ty.walk().all(|generic_arg| match generic_arg.unpack() {
+                    GenericArgKind::Type(inner_ty) if inner_ty != ty => {
+                        is_normalizable_helper(cx, param_env, inner_ty, cache)
+                    },
+                    _ => true, // if inner_ty == ty, we've already checked it
+                }),
+            }
+        } else {
+            false
+        }
+    });
+    cache.insert(ty, result);
+    result
 }
 
 pub fn match_def_path<'tcx>(cx: &LateContext<'tcx>, did: DefId, syms: &[&str]) -> bool {
@@ -1546,12 +1717,12 @@ pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool {
 /// ```
 pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_>, did: DefId) -> bool {
     use rustc_trait_selection::traits;
-    let predicates =
-        cx.tcx
-            .predicates_of(did)
-            .predicates
-            .iter()
-            .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
+    let predicates = cx
+        .tcx
+        .predicates_of(did)
+        .predicates
+        .iter()
+        .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
     traits::impossible_predicates(
         cx.tcx,
         traits::elaborate_predicates(cx.tcx, predicates)
diff --git a/src/tools/clippy/clippy_utils/src/paths.rs b/src/tools/clippy/clippy_utils/src/paths.rs
index c2da1f9b7c9..560614efc74 100644
--- a/src/tools/clippy/clippy_utils/src/paths.rs
+++ b/src/tools/clippy/clippy_utils/src/paths.rs
@@ -12,11 +12,9 @@ pub(super) const BEGIN_PANIC: [&str; 3] = ["std", "panicking", "begin_panic"];
 pub(super) const BEGIN_PANIC_FMT: [&str; 3] = ["std", "panicking", "begin_panic_fmt"];
 pub const BINARY_HEAP: [&str; 4] = ["alloc", "collections", "binary_heap", "BinaryHeap"];
 pub const BORROW_TRAIT: [&str; 3] = ["core", "borrow", "Borrow"];
-pub const BOX: [&str; 3] = ["alloc", "boxed", "Box"];
 pub const BTREEMAP: [&str; 5] = ["alloc", "collections", "btree", "map", "BTreeMap"];
 pub const BTREEMAP_ENTRY: [&str; 6] = ["alloc", "collections", "btree", "map", "entry", "Entry"];
 pub const BTREESET: [&str; 5] = ["alloc", "collections", "btree", "set", "BTreeSet"];
-pub const CLONE_TRAIT: [&str; 3] = ["core", "clone", "Clone"];
 pub const CLONE_TRAIT_METHOD: [&str; 4] = ["core", "clone", "Clone", "clone"];
 pub const CMP_MAX: [&str; 3] = ["core", "cmp", "max"];
 pub const CMP_MIN: [&str; 3] = ["core", "cmp", "min"];
@@ -43,9 +41,6 @@ pub const FILE_TYPE: [&str; 3] = ["std", "fs", "FileType"];
 pub const FMT_ARGUMENTS_NEW_V1: [&str; 4] = ["core", "fmt", "Arguments", "new_v1"];
 pub const FMT_ARGUMENTS_NEW_V1_FORMATTED: [&str; 4] = ["core", "fmt", "Arguments", "new_v1_formatted"];
 pub const FMT_ARGUMENTV1_NEW: [&str; 4] = ["core", "fmt", "ArgumentV1", "new"];
-pub const FN: [&str; 3] = ["core", "ops", "Fn"];
-pub const FN_MUT: [&str; 3] = ["core", "ops", "FnMut"];
-pub const FN_ONCE: [&str; 3] = ["core", "ops", "FnOnce"];
 pub const FROM_FROM: [&str; 4] = ["core", "convert", "From", "from"];
 pub const FROM_ITERATOR: [&str; 5] = ["core", "iter", "traits", "collect", "FromIterator"];
 pub const FUTURE_FROM_GENERATOR: [&str; 3] = ["core", "future", "from_generator"];
@@ -89,7 +84,6 @@ pub const OPTION: [&str; 3] = ["core", "option", "Option"];
 pub const OPTION_NONE: [&str; 4] = ["core", "option", "Option", "None"];
 pub const OPTION_SOME: [&str; 4] = ["core", "option", "Option", "Some"];
 pub const ORD: [&str; 3] = ["core", "cmp", "Ord"];
-pub const OS_STRING: [&str; 4] = ["std", "ffi", "os_str", "OsString"];
 pub const OS_STRING_AS_OS_STR: [&str; 5] = ["std", "ffi", "os_str", "OsString", "as_os_str"];
 pub const OS_STR_TO_OS_STRING: [&str; 5] = ["std", "ffi", "os_str", "OsStr", "to_os_string"];
 pub(super) const PANICKING_PANIC: [&str; 3] = ["core", "panicking", "panic"];
@@ -113,7 +107,6 @@ pub const PTR_SLICE_FROM_RAW_PARTS_MUT: [&str; 3] = ["core", "ptr", "slice_from_
 pub const PTR_SWAP_NONOVERLAPPING: [&str; 3] = ["core", "ptr", "swap_nonoverlapping"];
 pub const PUSH_STR: [&str; 4] = ["alloc", "string", "String", "push_str"];
 pub const RANGE_ARGUMENT_TRAIT: [&str; 3] = ["core", "ops", "RangeBounds"];
-pub const RC: [&str; 3] = ["alloc", "rc", "Rc"];
 pub const RC_PTR_EQ: [&str; 4] = ["alloc", "rc", "Rc", "ptr_eq"];
 pub const REFCELL_REF: [&str; 3] = ["core", "cell", "Ref"];
 pub const REFCELL_REFMUT: [&str; 3] = ["core", "cell", "RefMut"];
@@ -141,7 +134,6 @@ pub const STD_CONVERT_IDENTITY: [&str; 3] = ["std", "convert", "identity"];
 pub const STD_FS_CREATE_DIR: [&str; 3] = ["std", "fs", "create_dir"];
 pub const STD_MEM_TRANSMUTE: [&str; 3] = ["std", "mem", "transmute"];
 pub const STD_PTR_NULL: [&str; 3] = ["std", "ptr", "null"];
-pub const STRING: [&str; 3] = ["alloc", "string", "String"];
 pub const STRING_AS_MUT_STR: [&str; 4] = ["alloc", "string", "String", "as_mut_str"];
 pub const STRING_AS_STR: [&str; 4] = ["alloc", "string", "String", "as_str"];
 pub const STR_ENDS_WITH: [&str; 4] = ["core", "str", "<impl str>", "ends_with"];
@@ -160,9 +152,7 @@ pub const SYMBOL_TO_IDENT_STRING: [&str; 4] = ["rustc_span", "symbol", "Symbol",
 pub const SYM_MODULE: [&str; 3] = ["rustc_span", "symbol", "sym"];
 #[cfg(feature = "internal-lints")]
 pub const SYNTAX_CONTEXT: [&str; 3] = ["rustc_span", "hygiene", "SyntaxContext"];
-pub const TO_OWNED: [&str; 3] = ["alloc", "borrow", "ToOwned"];
 pub const TO_OWNED_METHOD: [&str; 4] = ["alloc", "borrow", "ToOwned", "to_owned"];
-pub const TO_STRING: [&str; 3] = ["alloc", "string", "ToString"];
 pub const TO_STRING_METHOD: [&str; 4] = ["alloc", "string", "ToString", "to_string"];
 pub const TRANSMUTE: [&str; 4] = ["core", "intrinsics", "", "transmute"];
 pub const TRY_FROM: [&str; 4] = ["core", "convert", "TryFrom", "try_from"];
diff --git a/src/tools/clippy/clippy_utils/src/ptr.rs b/src/tools/clippy/clippy_utils/src/ptr.rs
index baeff08e02c..df6143edbca 100644
--- a/src/tools/clippy/clippy_utils/src/ptr.rs
+++ b/src/tools/clippy/clippy_utils/src/ptr.rs
@@ -36,11 +36,7 @@ fn extract_clone_suggestions<'tcx>(
         abort: false,
     };
     visitor.visit_body(body);
-    if visitor.abort {
-        None
-    } else {
-        Some(visitor.spans)
-    }
+    if visitor.abort { None } else { Some(visitor.spans) }
 }
 
 struct PtrCloneVisitor<'a, 'tcx> {