Fix adjacent code

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

@@ -7,14 +7,14 @@ 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::visitors::for_each_expr;
-use clippy_utils::{match_def_path, return_ty, trait_ref_of_method};
+use clippy_utils::{return_ty, trait_ref_of_method};
 
 use core::ops::ControlFlow;
 
@@ -181,15 +181,17 @@ 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/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,

clippy_lints/src/loops/needless_range_loop.rs

@@ -3,7 +3,7 @@ use clippy_utils::diagnostics::{multispan_sugg, span_lint_and_then};
 use clippy_utils::source::snippet;
 use clippy_utils::ty::has_iter_method;
 use clippy_utils::visitors::is_local_used;
-use clippy_utils::{contains_name, higher, is_integer_const, match_trait_method, paths, sugg, SpanlessEq};
+use clippy_utils::{contains_name, higher, is_integer_const, sugg, SpanlessEq};
 use if_chain::if_chain;
 use rustc_ast::ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
@@ -302,8 +302,13 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> {
         if_chain! {
             // a range index op
             if let ExprKind::MethodCall(meth, args_0, [args_1, ..], _) = &expr.kind;
-            if (meth.ident.name == sym::index && match_trait_method(self.cx, expr, &paths::INDEX))
-                || (meth.ident.name == sym::index_mut && match_trait_method(self.cx, expr, &paths::INDEX_MUT));
+            if let Some(trait_id) = self
+                .cx
+                .typeck_results()
+                .type_dependent_def_id(expr.hir_id)
+                .and_then(|def_id| self.cx.tcx.trait_of_item(def_id));
+            if (meth.ident.name == sym::index && self.cx.tcx.lang_items().index_trait() == Some(trait_id))
+                || (meth.ident.name == sym::index_mut && self.cx.tcx.lang_items().index_mut_trait() == Some(trait_id));
             if !self.check(args_1, args_0, expr);
             then { return }
         }

clippy_lints/src/manual_async_fn.rs

@@ -1,6 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::match_function_call;
-use clippy_utils::paths::FUTURE_FROM_GENERATOR;
+use clippy_utils::match_function_call_with_def_id;
 use clippy_utils::source::{position_before_rarrow, snippet_block, snippet_opt};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
@@ -175,7 +174,11 @@ fn captures_all_lifetimes(inputs: &[Ty<'_>], output_lifetimes: &[LifetimeName])
 fn desugared_async_block<'tcx>(cx: &LateContext<'tcx>, block: &'tcx Block<'tcx>) -> Option<&'tcx Body<'tcx>> {
     if_chain! {
         if let Some(block_expr) = block.expr;
-        if let Some(args) = match_function_call(cx, block_expr, &FUTURE_FROM_GENERATOR);
+        if let Some(args) = cx
+            .tcx
+            .lang_items()
+            .from_generator_fn()
+            .and_then(|def_id| match_function_call_with_def_id(cx, block_expr, def_id));
         if args.len() == 1;
         if let Expr{kind: ExprKind::Closure(&Closure { body, .. }), ..} = args[0];
         let closure_body = cx.tcx.hir().body(body);

clippy_lints/src/manual_clamp.rs

@@ -12,9 +12,9 @@ use std::ops::Deref;
 
 use clippy_utils::{
     diagnostics::{span_lint_and_then, span_lint_hir_and_then},
-    eq_expr_value, get_trait_def_id,
+    eq_expr_value,
     higher::If,
-    is_diag_trait_item, is_trait_method, meets_msrv, msrvs, path_res, path_to_local_id, paths, peel_blocks,
+    is_diag_trait_item, is_trait_method, meets_msrv, msrvs, path_res, path_to_local_id, peel_blocks,
     peel_blocks_with_stmt,
     sugg::Sugg,
     ty::implements_trait,
@@ -190,7 +190,11 @@ impl TypeClampability {
     fn is_clampable<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<TypeClampability> {
         if ty.is_floating_point() {
             Some(TypeClampability::Float)
-        } else if get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[])) {
+        } else if cx
+            .tcx
+            .get_diagnostic_item(sym::Ord)
+            .map_or(false, |id| implements_trait(cx, ty, id, &[]))
+        {
             Some(TypeClampability::Ord)
         } else {
             None

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/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
                         }

clippy_lints/src/methods/or_fun_call.rs

@@ -1,14 +1,14 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::eager_or_lazy::switch_to_lazy_eval;
 use clippy_utils::source::{snippet, snippet_with_macro_callsite};
-use clippy_utils::ty::{implements_trait, match_type};
-use clippy_utils::{contains_return, is_trait_item, last_path_segment, paths};
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{contains_return, is_trait_item, last_path_segment};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
 use rustc_span::source_map::Span;
-use rustc_span::symbol::{kw, sym};
+use rustc_span::symbol::{kw, sym, Symbol};
 use std::borrow::Cow;
 
 use super::OR_FUN_CALL;
@@ -88,11 +88,11 @@ pub(super) fn check<'tcx>(
         fun_span: Option<Span>,
     ) {
         // (path, fn_has_argument, methods, suffix)
-        const KNOW_TYPES: [(&[&str], bool, &[&str], &str); 4] = [
-            (&paths::BTREEMAP_ENTRY, false, &["or_insert"], "with"),
-            (&paths::HASHMAP_ENTRY, false, &["or_insert"], "with"),
-            (&paths::OPTION, false, &["map_or", "ok_or", "or", "unwrap_or"], "else"),
-            (&paths::RESULT, true, &["or", "unwrap_or"], "else"),
+        const KNOW_TYPES: [(Symbol, bool, &[&str], &str); 4] = [
+            (sym::BTreeEntry, false, &["or_insert"], "with"),
+            (sym::HashMapEntry, false, &["or_insert"], "with"),
+            (sym::Option, false, &["map_or", "ok_or", "or", "unwrap_or"], "else"),
+            (sym::Result, true, &["or", "unwrap_or"], "else"),
         ];
 
         if_chain! {
@@ -104,7 +104,7 @@ pub(super) fn check<'tcx>(
             let self_ty = cx.typeck_results().expr_ty(self_expr);
 
             if let Some(&(_, fn_has_arguments, poss, suffix)) =
-                KNOW_TYPES.iter().find(|&&i| match_type(cx, self_ty, i.0));
+                KNOW_TYPES.iter().find(|&&i| is_type_diagnostic_item(cx, self_ty, i.0));
 
             if poss.contains(&name);
 

clippy_lints/src/neg_cmp_op_on_partial_ord.rs

@@ -1,11 +1,11 @@
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::ty::implements_trait;
-use clippy_utils::{self, get_trait_def_id, paths};
 use if_chain::if_chain;
 use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -58,7 +58,7 @@ impl<'tcx> LateLintPass<'tcx> for NoNegCompOpForPartialOrd {
                 let ty = cx.typeck_results().expr_ty(left);
 
                 let implements_ord = {
-                    if let Some(id) = get_trait_def_id(cx, &paths::ORD) {
+                    if let Some(id) = cx.tcx.get_diagnostic_item(sym::Ord) {
                         implements_trait(cx, ty, id, &[])
                     } else {
                         return;

clippy_lints/src/operators/cmp_owned.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
 use clippy_utils::ty::{implements_trait, is_copy};
-use clippy_utils::{match_any_def_paths, path_def_id, paths};
+use clippy_utils::{match_def_path, path_def_id, paths};
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
 use rustc_lint::LateContext;
@@ -49,13 +49,15 @@ fn check_op(cx: &LateContext<'_>, expr: &Expr<'_>, other: &Expr<'_>, left: bool)
             (arg, arg.span)
         },
         ExprKind::Call(path, [arg])
-            if path_def_id(cx, path)
-                .and_then(|id| match_any_def_paths(cx, id, &[&paths::FROM_STR_METHOD, &paths::FROM_FROM]))
-                .map_or(false, |idx| match idx {
-                    0 => true,
-                    1 => !is_copy(cx, typeck.expr_ty(expr)),
-                    _ => false,
-                }) =>
+            if path_def_id(cx, path).map_or(false, |id| {
+                if match_def_path(cx, id, &paths::FROM_STR_METHOD) {
+                    true
+                } else if cx.tcx.lang_items().from_fn() == Some(id) {
+                    !is_copy(cx, typeck.expr_ty(expr))
+                } else {
+                    false
+                }
+            }) =>
         {
             (arg, arg.span)
         },