Fix adjacent code

clippy_lints/src/await_holding_invalid.rs

@@ -6,7 +6,7 @@ use rustc_hir::{def::Res, AsyncGeneratorKind, Body, BodyId, GeneratorKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::GeneratorInteriorTypeCause;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
-use rustc_span::Span;
+use rustc_span::{sym, Span};
 
 use crate::utils::conf::DisallowedType;
 
@@ -276,9 +276,9 @@ fn emit_invalid_type(cx: &LateContext<'_>, span: Span, disallowed: &DisallowedTy
 }
 
 fn is_mutex_guard(cx: &LateContext<'_>, def_id: DefId) -> bool {
-    match_def_path(cx, def_id, &paths::MUTEX_GUARD)
-        || match_def_path(cx, def_id, &paths::RWLOCK_READ_GUARD)
-        || match_def_path(cx, def_id, &paths::RWLOCK_WRITE_GUARD)
+    cx.tcx.is_diagnostic_item(sym::MutexGuard, def_id)
+        || cx.tcx.is_diagnostic_item(sym::RwLockReadGuard, def_id)
+        || cx.tcx.is_diagnostic_item(sym::RwLockWriteGuard, def_id)
         || match_def_path(cx, def_id, &paths::PARKING_LOT_MUTEX_GUARD)
         || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_READ_GUARD)
         || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_WRITE_GUARD)

clippy_lints/src/booleans.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then};
+use clippy_utils::eq_expr_value;
 use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
-use clippy_utils::{eq_expr_value, get_trait_def_id, paths};
 use if_chain::if_chain;
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
@@ -483,7 +483,9 @@ impl<'a, 'tcx> Visitor<'tcx> for NonminimalBoolVisitor<'a, 'tcx> {
 
 fn implements_ord<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> bool {
     let ty = cx.typeck_results().expr_ty(expr);
-    get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[]))
+    cx.tcx
+        .get_diagnostic_item(sym::Ord)
+        .map_or(false, |id| implements_trait(cx, ty, id, &[]))
 }
 
 struct NotSimplificationVisitor<'a, 'tcx> {

clippy_lints/src/comparison_chain.rs

@@ -1,9 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::ty::implements_trait;
-use clippy_utils::{get_trait_def_id, if_sequence, in_constant, is_else_clause, paths, SpanlessEq};
+use clippy_utils::{if_sequence, in_constant, is_else_clause, SpanlessEq};
 use rustc_hir::{BinOpKind, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -106,7 +107,10 @@ impl<'tcx> LateLintPass<'tcx> for ComparisonChain {
 
                 // Check that the type being compared implements `core::cmp::Ord`
                 let ty = cx.typeck_results().expr_ty(lhs1);
-                let is_ord = get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[]));
+                let is_ord = cx
+                    .tcx
+                    .get_diagnostic_item(sym::Ord)
+                    .map_or(false, |id| implements_trait(cx, ty, id, &[]));
 
                 if !is_ord {
                     return;

clippy_lints/src/functions/must_use.rs

@@ -7,13 +7,13 @@ use rustc_middle::{
     lint::in_external_macro,
     ty::{self, Ty},
 };
-use rustc_span::{sym, Span};
+use rustc_span::{sym, Span, Symbol};
 
 use clippy_utils::attrs::is_proc_macro;
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_then};
 use clippy_utils::source::snippet_opt;
 use clippy_utils::ty::is_must_use_ty;
-use clippy_utils::{match_def_path, return_ty, trait_ref_of_method};
+use clippy_utils::{return_ty, trait_ref_of_method};
 
 use super::{DOUBLE_MUST_USE, MUST_USE_CANDIDATE, MUST_USE_UNIT};
 
@@ -178,15 +178,17 @@ fn is_mutable_pat(cx: &LateContext<'_>, pat: &hir::Pat<'_>, tys: &mut DefIdSet)
     }
 }
 
-static KNOWN_WRAPPER_TYS: &[&[&str]] = &[&["alloc", "rc", "Rc"], &["std", "sync", "Arc"]];
+static KNOWN_WRAPPER_TYS: &[Symbol] = &[sym::Rc, sym::Arc];
 
 fn is_mutable_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>, span: Span, tys: &mut DefIdSet) -> bool {
     match *ty.kind() {
         // primitive types are never mutable
         ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => false,
         ty::Adt(adt, substs) => {
             tys.insert(adt.did()) && !ty.is_freeze(cx.tcx.at(span), cx.param_env)
-                || KNOWN_WRAPPER_TYS.iter().any(|path| match_def_path(cx, adt.did(), path))
+                || KNOWN_WRAPPER_TYS
+                    .iter()
+                    .any(|&sym| cx.tcx.is_diagnostic_item(sym, adt.did()))
                     && substs.types().any(|ty| is_mutable_ty(cx, ty, span, tys))
         },
         ty::Tuple(substs) => substs.iter().any(|ty| is_mutable_ty(cx, ty, span, tys)),

clippy_lints/src/infinite_iter.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
-use clippy_utils::{higher, match_def_path, path_def_id, paths};
+use clippy_utils::{higher, path_def_id};
 use rustc_hir::{BorrowKind, Closure, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -169,7 +169,7 @@ fn is_infinite(cx: &LateContext<'_>, expr: &Expr<'_>) -> Finiteness {
         ExprKind::Block(block, _) => block.expr.as_ref().map_or(Finite, |e| is_infinite(cx, e)),
         ExprKind::Box(e) | ExprKind::AddrOf(BorrowKind::Ref, _, e) => is_infinite(cx, e),
         ExprKind::Call(path, _) => path_def_id(cx, path)
-            .map_or(false, |id| match_def_path(cx, id, &paths::ITER_REPEAT))
+            .map_or(false, |id| cx.tcx.is_diagnostic_item(sym::iter_repeat, id))
             .into(),
         ExprKind::Struct(..) => higher::Range::hir(expr).map_or(false, |r| r.end.is_none()).into(),
         _ => Finite,

clippy_lints/src/inherent_to_string.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
-use clippy_utils::{get_trait_def_id, paths, return_ty, trait_ref_of_method};
+use clippy_utils::{return_ty, trait_ref_of_method};
 use if_chain::if_chain;
 use rustc_hir::{GenericParamKind, ImplItem, ImplItemKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -118,7 +118,10 @@ impl<'tcx> LateLintPass<'tcx> for InherentToString {
 }
 
 fn show_lint(cx: &LateContext<'_>, item: &ImplItem<'_>) {
-    let display_trait_id = get_trait_def_id(cx, &paths::DISPLAY_TRAIT).expect("Failed to get trait ID of `Display`!");
+    let display_trait_id = cx
+        .tcx
+        .get_diagnostic_item(sym::Display)
+        .expect("Failed to get trait ID of `Display`!");
 
     // Get the real type of 'self'
     let self_type = cx.tcx.fn_sig(item.def_id).input(0);

clippy_lints/src/let_underscore.rs

@@ -1,12 +1,13 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use clippy_utils::ty::{is_must_use_ty, match_type};
+use clippy_utils::ty::{is_must_use_ty, is_type_diagnostic_item, match_type};
 use clippy_utils::{is_must_use_func_call, paths};
 use if_chain::if_chain;
 use rustc_hir::{Local, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{sym, Symbol};
 
 declare_clippy_lint! {
     /// ### What it does
@@ -99,10 +100,9 @@ declare_clippy_lint! {
 
 declare_lint_pass!(LetUnderscore => [LET_UNDERSCORE_MUST_USE, LET_UNDERSCORE_LOCK, LET_UNDERSCORE_DROP]);
 
-const SYNC_GUARD_PATHS: [&[&str]; 6] = [
-    &paths::MUTEX_GUARD,
-    &paths::RWLOCK_READ_GUARD,
-    &paths::RWLOCK_WRITE_GUARD,
+const SYNC_GUARD_SYMS: [Symbol; 3] = [sym::MutexGuard, sym::RwLockReadGuard, sym::RwLockWriteGuard];
+
+const SYNC_GUARD_PATHS: [&[&str]; 3] = [
     &paths::PARKING_LOT_MUTEX_GUARD,
     &paths::PARKING_LOT_RWLOCK_READ_GUARD,
     &paths::PARKING_LOT_RWLOCK_WRITE_GUARD,
@@ -121,7 +121,10 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                 let init_ty = cx.typeck_results().expr_ty(init);
                 let contains_sync_guard = init_ty.walk().any(|inner| match inner.unpack() {
                     GenericArgKind::Type(inner_ty) => {
-                        SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, inner_ty, path))
+                        SYNC_GUARD_SYMS
+                            .iter()
+                            .any(|&sym| is_type_diagnostic_item(cx, inner_ty, sym))
+                            || SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, inner_ty, path))
                     },
 
                     GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
@@ -134,7 +137,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                         "non-binding let on a synchronization lock",
                         None,
                         "consider using an underscore-prefixed named \
-                            binding or dropping explicitly with `std::mem::drop`"
+                            binding or dropping explicitly with `std::mem::drop`",
                     );
                 } else if init_ty.needs_drop(cx.tcx, cx.param_env) {
                     span_lint_and_help(
@@ -144,7 +147,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                         "non-binding `let` on a type that implements `Drop`",
                         None,
                         "consider using an underscore-prefixed named \
-                            binding or dropping explicitly with `std::mem::drop`"
+                            binding or dropping explicitly with `std::mem::drop`",
                     );
                 } else if is_must_use_ty(cx, cx.typeck_results().expr_ty(init)) {
                     span_lint_and_help(
@@ -153,7 +156,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                         local.span,
                         "non-binding let on an expression with `#[must_use]` type",
                         None,
-                        "consider explicitly using expression value"
+                        "consider explicitly using expression value",
                     );
                 } else if is_must_use_func_call(cx, init) {
                     span_lint_and_help(
@@ -162,7 +165,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                         local.span,
                         "non-binding let on a result of a `#[must_use]` function",
                         None,
-                        "consider explicitly using function result"
+                        "consider explicitly using function result",
                     );
                 }
             }

clippy_lints/src/matches/single_match.rs

@@ -1,14 +1,13 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::{expr_block, snippet};
-use clippy_utils::ty::{implements_trait, match_type, peel_mid_ty_refs};
-use clippy_utils::{
-    is_lint_allowed, is_unit_expr, is_wild, paths, peel_blocks, peel_hir_pat_refs, peel_n_hir_expr_refs,
-};
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item, peel_mid_ty_refs};
+use clippy_utils::{is_lint_allowed, is_unit_expr, is_wild, peel_blocks, peel_hir_pat_refs, peel_n_hir_expr_refs};
 use core::cmp::max;
 use rustc_errors::Applicability;
 use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, Pat, PatKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, Ty};
+use rustc_span::sym;
 
 use super::{MATCH_BOOL, SINGLE_MATCH, SINGLE_MATCH_ELSE};
 
@@ -156,10 +155,10 @@ fn pat_in_candidate_enum<'a>(cx: &LateContext<'a>, ty: Ty<'a>, pat: &Pat<'_>) ->
 /// Returns `true` if the given type is an enum we know won't be expanded in the future
 fn in_candidate_enum<'a>(cx: &LateContext<'a>, ty: Ty<'_>) -> bool {
     // list of candidate `Enum`s we know will never get any more members
-    let candidates = [&paths::COW, &paths::OPTION, &paths::RESULT];
+    let candidates = [sym::Cow, sym::Option, sym::Result];
 
     for candidate_ty in candidates {
-        if match_type(cx, ty, candidate_ty) {
+        if is_type_diagnostic_item(cx, ty, candidate_ty) {
             return true;
         }
     }

clippy_lints/src/methods/filetype_is_file.rs

@@ -1,17 +1,17 @@
 use clippy_utils::diagnostics::span_lint_and_help;
-use clippy_utils::ty::match_type;
-use clippy_utils::{get_parent_expr, paths};
+use clippy_utils::get_parent_expr;
+use clippy_utils::ty::is_type_diagnostic_item;
 use if_chain::if_chain;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
-use rustc_span::source_map::Span;
+use rustc_span::{source_map::Span, sym};
 
 use super::FILETYPE_IS_FILE;
 
 pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>) {
     let ty = cx.typeck_results().expr_ty(recv);
 
-    if !match_type(cx, ty, &paths::FILE_TYPE) {
+    if !is_type_diagnostic_item(cx, ty, sym::FileType) {
         return;
     }
 

clippy_lints/src/methods/inefficient_to_string.rs

@@ -65,7 +65,7 @@ fn specializes_tostring(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
     }
 
     if let ty::Adt(adt, substs) = ty.kind() {
-        match_def_path(cx, adt.did(), &paths::COW) && substs.type_at(1).is_str()
+        cx.tcx.is_diagnostic_item(sym::Cow, adt.did()) && substs.type_at(1).is_str()
     } else {
         false
     }

clippy_lints/src/methods/manual_str_repeat.rs

@@ -1,8 +1,8 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::is_path_diagnostic_item;
 use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
 use clippy_utils::sugg::Sugg;
-use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item, match_type};
-use clippy_utils::{is_expr_path_def_path, paths};
+use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
 use if_chain::if_chain;
 use rustc_ast::LitKind;
 use rustc_errors::Applicability;
@@ -38,7 +38,7 @@ fn parse_repeat_arg(cx: &LateContext<'_>, e: &Expr<'_>) -> Option<RepeatKind> {
         let ty = cx.typeck_results().expr_ty(e);
         if is_type_diagnostic_item(cx, ty, sym::String)
             || (is_type_lang_item(cx, ty, LangItem::OwnedBox) && get_ty_param(ty).map_or(false, Ty::is_str))
-            || (match_type(cx, ty, &paths::COW) && get_ty_param(ty).map_or(false, Ty::is_str))
+            || (is_type_diagnostic_item(cx, ty, sym::Cow) && get_ty_param(ty).map_or(false, Ty::is_str))
         {
             Some(RepeatKind::String)
         } else {
@@ -57,7 +57,7 @@ pub(super) fn check(
 ) {
     if_chain! {
         if let ExprKind::Call(repeat_fn, [repeat_arg]) = take_self_arg.kind;
-        if is_expr_path_def_path(cx, repeat_fn, &paths::ITER_REPEAT);
+        if is_path_diagnostic_item(cx, repeat_fn,sym::iter_repeat);
         if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(collect_expr), sym::String);
         if let Some(collect_id) = cx.typeck_results().type_dependent_def_id(collect_expr.hir_id);
         if let Some(take_id) = cx.typeck_results().type_dependent_def_id(take_expr.hir_id);

clippy_lints/src/methods/mod.rs

@@ -102,9 +102,7 @@ use bind_instead_of_map::BindInsteadOfMap;
 use clippy_utils::consts::{constant, Constant};
 use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
 use clippy_utils::ty::{contains_adt_constructor, implements_trait, is_copy, is_type_diagnostic_item};
-use clippy_utils::{
-    contains_return, get_trait_def_id, is_trait_method, iter_input_pats, meets_msrv, msrvs, paths, return_ty,
-};
+use clippy_utils::{contains_return, is_trait_method, iter_input_pats, meets_msrv, msrvs, return_ty};
 use if_chain::if_chain;
 use rustc_hir as hir;
 use rustc_hir::def::Res;
@@ -3846,12 +3844,12 @@ impl SelfKind {
                 return m == mutability && t == parent_ty;
             }
 
-            let trait_path = match mutability {
-                hir::Mutability::Not => &paths::ASREF_TRAIT,
-                hir::Mutability::Mut => &paths::ASMUT_TRAIT,
+            let trait_sym = match mutability {
+                hir::Mutability::Not => sym::AsRef,
+                hir::Mutability::Mut => sym::AsMut,
             };
 
-            let trait_def_id = match get_trait_def_id(cx, trait_path) {
+            let trait_def_id = match cx.tcx.get_diagnostic_item(trait_sym) {
                 Some(did) => did,
                 None => return false,
             };

clippy_lints/src/methods/option_as_ref_deref.rs

@@ -32,8 +32,7 @@ pub(super) fn check<'tcx>(
         return;
     }
 
-    let deref_aliases: [&[&str]; 9] = [
-        &paths::DEREF_TRAIT_METHOD,
+    let deref_aliases: [&[&str]; 8] = [
         &paths::DEREF_MUT_TRAIT_METHOD,
         &paths::CSTRING_AS_C_STR,
         &paths::OS_STRING_AS_OS_STR,
@@ -45,12 +44,14 @@ pub(super) fn check<'tcx>(
     ];
 
     let is_deref = match map_arg.kind {
-        hir::ExprKind::Path(ref expr_qpath) => cx
-            .qpath_res(expr_qpath, map_arg.hir_id)
-            .opt_def_id()
-            .map_or(false, |fun_def_id| {
-                deref_aliases.iter().any(|path| match_def_path(cx, fun_def_id, path))
-            }),
+        hir::ExprKind::Path(ref expr_qpath) => {
+            cx.qpath_res(expr_qpath, map_arg.hir_id)
+                .opt_def_id()
+                .map_or(false, |fun_def_id| {
+                    cx.tcx.is_diagnostic_item(sym::deref_method, fun_def_id)
+                        || deref_aliases.iter().any(|path| match_def_path(cx, fun_def_id, path))
+                })
+        },
         hir::ExprKind::Closure(&hir::Closure { body, .. }) => {
             let closure_body = cx.tcx.hir().body(body);
             let closure_expr = peel_blocks(closure_body.value);
@@ -68,7 +69,8 @@ pub(super) fn check<'tcx>(
                         if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj;
                         then {
                             let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap();
-                            deref_aliases.iter().any(|path| match_def_path(cx, method_did, path))
+                            cx.tcx.is_diagnostic_item(sym::deref_method, method_did)
+                                || deref_aliases.iter().any(|path| match_def_path(cx, method_did, path))
                         } else {
                             false
                         }