hir: Remove opt_local_def_id_to_hir_id and opt_hir_node_by_def_id

Also replace a few `hir_node()` calls with `hir_node_by_def_id()`

clippy_lints/src/escape.rs

@@ -76,10 +76,9 @@ fn check_fn(
             .hir()
             .get_parent_item(cx.tcx.local_def_id_to_hir_id(fn_def_id))
             .def_id;
-        let parent_node = cx.tcx.opt_hir_node_by_def_id(parent_id);
 
         let mut trait_self_ty = None;
-        if let Some(Node::Item(item)) = parent_node {
+        if let Node::Item(item) = cx.tcx.hir_node_by_def_id(parent_id) {
             // If the method is an impl for a trait, don't warn.
             if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = item.kind {
                 return;

clippy_lints/src/exit.rs

@@ -46,7 +46,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) {
             && let Some(def_id) = cx.qpath_res(path, path_expr.hir_id).opt_def_id()
             && cx.tcx.is_diagnostic_item(sym::process_exit, def_id)
             && let parent = cx.tcx.hir().get_parent_item(e.hir_id).def_id
-            && let Some(Node::Item(Item{kind: ItemKind::Fn(..), ..})) = cx.tcx.opt_hir_node_by_def_id(parent)
+            && let Node::Item(Item{kind: ItemKind::Fn(..), ..}) = cx.tcx.hir_node_by_def_id(parent)
             // If the next item up is a function we check if it is an entry point
             // and only then emit a linter warning
             && !is_entrypoint_fn(cx, parent.to_def_id())

clippy_lints/src/functions/result.rs

@@ -92,7 +92,7 @@ fn check_result_large_err<'tcx>(cx: &LateContext<'tcx>, err_ty: Ty<'tcx>, hir_ty
             .expect("already checked this is adt")
             .did()
             .as_local()
-        && let Some(hir::Node::Item(item)) = cx.tcx.opt_hir_node_by_def_id(local_def_id)
+        && let hir::Node::Item(item) = cx.tcx.hir_node_by_def_id(local_def_id)
         && let hir::ItemKind::Enum(ref def, _) = item.kind
     {
         let variants_size = AdtVariantInfo::new(cx, *adt, subst);

clippy_lints/src/misc.rs

@@ -225,10 +225,9 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
                 if let Some(adt_def) = cx.typeck_results().expr_ty_adjusted(recv).ty_adt_def()
                     && let Some(field) = adt_def.all_fields().find(|field| field.name == ident.name)
                     && let Some(local_did) = field.did.as_local()
-                    && let Some(hir_id) = cx.tcx.opt_local_def_id_to_hir_id(local_did)
                     && !cx.tcx.type_of(field.did).skip_binder().is_phantom_data()
                 {
-                    (hir_id, ident)
+                    (cx.tcx.local_def_id_to_hir_id(local_did), ident)
                 } else {
                     return;
                 }

clippy_lints/src/missing_fields_in_debug.rs

@@ -220,7 +220,7 @@ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx rustc_hir::Item<'tc
             && let self_ty = cx.tcx.type_of(self_path_did).skip_binder().peel_refs()
             && let Some(self_adt) = self_ty.ty_adt_def()
             && let Some(self_def_id) = self_adt.did().as_local()
-            && let Some(Node::Item(self_item)) = cx.tcx.opt_hir_node_by_def_id(self_def_id)
+            && let Node::Item(self_item) = cx.tcx.hir_node_by_def_id(self_def_id)
             // NB: can't call cx.typeck_results() as we are not in a body
             && let typeck_results = cx.tcx.typeck_body(*body_id)
             && should_lint(cx, typeck_results, block)

clippy_lints/src/needless_pass_by_ref_mut.rs

@@ -112,10 +112,7 @@ fn check_closures<'tcx>(
         }
         ctx.prev_bind = None;
         ctx.prev_move_to_closure.clear();
-        if let Some(body) = cx
+        if let Some(body) = associated_body(cx.tcx.hir_node_by_def_id(closure))
-            .tcx
-            .opt_hir_node_by_def_id(closure)
-            .and_then(associated_body)
             .map(|(_, body_id)| hir.body(body_id))
         {
             euv::ExprUseVisitor::new(ctx, infcx, closure, cx.param_env, cx.typeck_results()).consume_body(body);

clippy_lints/src/self_named_constructors.rs

@@ -72,8 +72,7 @@ fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<
 
         if let Some(self_def) = self_ty.ty_adt_def()
             && let Some(self_local_did) = self_def.did().as_local()
-            && let self_id = cx.tcx.local_def_id_to_hir_id(self_local_did)
+            && let Node::Item(x) = cx.tcx.hir_node_by_def_id(self_local_did)
-            && let Node::Item(x) = cx.tcx.hir_node(self_id)
             && let type_name = x.ident.name.as_str().to_lowercase()
             && (impl_item.ident.name.as_str() == type_name
                 || impl_item.ident.name.as_str().replace('_', "") == type_name)

clippy_lints/src/single_call_fn.rs

@@ -95,7 +95,7 @@ fn is_function_allowed(
 /// to be considered.
 fn is_valid_item_kind(cx: &LateContext<'_>, def_id: LocalDefId) -> bool {
     matches!(
-        cx.tcx.hir_node(cx.tcx.local_def_id_to_hir_id(def_id)),
+        cx.tcx.hir_node_by_def_id(def_id),
         Node::Item(_) | Node::ImplItem(_) | Node::TraitItem(_)
     )
 }

clippy_lints/src/types/mod.rs

@@ -321,7 +321,7 @@ fn check_fn(
         _: Span,
         def_id: LocalDefId,
     ) {
-        let is_in_trait_impl = if let Some(hir::Node::Item(item)) = cx.tcx.opt_hir_node_by_def_id(
+        let is_in_trait_impl = if let hir::Node::Item(item) = cx.tcx.hir_node_by_def_id(
             cx.tcx
                 .hir()
                 .get_parent_item(cx.tcx.local_def_id_to_hir_id(def_id))
@@ -366,9 +366,9 @@ fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'tcx>) {
         match item.kind {
             ImplItemKind::Const(ty, _) => {
-                let is_in_trait_impl = if let Some(hir::Node::Item(item)) = cx
+                let is_in_trait_impl = if let hir::Node::Item(item) = cx
                     .tcx
-                    .opt_hir_node_by_def_id(cx.tcx.hir().get_parent_item(item.hir_id()).def_id)
+                    .hir_node_by_def_id(cx.tcx.hir().get_parent_item(item.hir_id()).def_id)
                 {
                     matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }))
                 } else {

clippy_lints/src/zero_sized_map_values.rs

@@ -74,7 +74,7 @@ fn check_ty<'tcx>(&mut self, cx: &LateContext<'tcx>, hir_ty: &hir::Ty<'tcx>) {
 fn in_trait_impl(cx: &LateContext<'_>, hir_id: HirId) -> bool {
     let parent_id = cx.tcx.hir().get_parent_item(hir_id);
     let second_parent_id = cx.tcx.hir().get_parent_item(parent_id.into()).def_id;
-    if let Some(Node::Item(item)) = cx.tcx.opt_hir_node_by_def_id(second_parent_id) {
+    if let Node::Item(item) = cx.tcx.hir_node_by_def_id(second_parent_id) {
         if let ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = item.kind {
             return true;
         }

clippy_utils/src/lib.rs

@@ -330,8 +330,7 @@ pub fn is_trait_method(cx: &LateContext<'_>, expr: &Expr<'_>, diag_item: Symbol)
 
 /// Checks if the `def_id` belongs to a function that is part of a trait impl.
 pub fn is_def_id_trait_method(cx: &LateContext<'_>, def_id: LocalDefId) -> bool {
-    if let Some(hir_id) = cx.tcx.opt_local_def_id_to_hir_id(def_id)
+    if let Node::Item(item) = cx.tcx.parent_hir_node(cx.tcx.local_def_id_to_hir_id(def_id))
-        && let Node::Item(item) = cx.tcx.parent_hir_node(hir_id)
         && let ItemKind::Impl(imp) = item.kind
     {
         imp.of_trait.is_some()
@@ -574,12 +573,12 @@ fn local_item_children_by_name(tcx: TyCtxt<'_>, local_id: LocalDefId, name: Symb
     let hir = tcx.hir();
 
     let root_mod;
-    let item_kind = match tcx.opt_hir_node_by_def_id(local_id) {
+    let item_kind = match tcx.hir_node_by_def_id(local_id) {
-        Some(Node::Crate(r#mod)) => {
+        Node::Crate(r#mod) => {
             root_mod = ItemKind::Mod(r#mod);
             &root_mod
         },
-        Some(Node::Item(item)) => &item.kind,
+        Node::Item(item) => &item.kind,
         _ => return Vec::new(),
     };
 
@@ -1254,12 +1253,10 @@ pub fn is_in_panic_handler(cx: &LateContext<'_>, e: &Expr<'_>) -> bool {
 /// Gets the name of the item the expression is in, if available.
 pub fn get_item_name(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option<Symbol> {
     let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id).def_id;
-    match cx.tcx.opt_hir_node_by_def_id(parent_id) {
+    match cx.tcx.hir_node_by_def_id(parent_id) {
-        Some(
+        Node::Item(Item { ident, .. })
-            Node::Item(Item { ident, .. })
+        | Node::TraitItem(TraitItem { ident, .. })
-            | Node::TraitItem(TraitItem { ident, .. })
+        | Node::ImplItem(ImplItem { ident, .. }) => Some(ident.name),
-            | Node::ImplItem(ImplItem { ident, .. }),
-        ) => Some(ident.name),
         _ => None,
     }
 }
@@ -2667,11 +2664,10 @@ pub fn defined_ty(&self, cx: &LateContext<'tcx>) -> Option<DefinedTy<'tcx>> {
                     .and(Binder::dummy(cx.tcx.type_of(id).instantiate_identity())),
             )),
             Self::Return(id) => {
-                let hir_id = cx.tcx.local_def_id_to_hir_id(id.def_id);
                 if let Node::Expr(Expr {
                     kind: ExprKind::Closure(c),
                     ..
-                }) = cx.tcx.hir_node(hir_id)
+                }) = cx.tcx.hir_node_by_def_id(id.def_id)
                 {
                     match c.fn_decl.output {
                         FnRetTy::DefaultReturn(_) => None,