Auto merge of #81611 - cjgillot:meowner, r=estebank

Only store a LocalDefId in some HIR nodes

Some HIR nodes are guaranteed to be HIR owners: Item, TraitItem, ImplItem, ForeignItem and MacroDef.
As a consequence, we do not need to store the `HirId`'s `local_id`, and we can directly store a `LocalDefId`.

This allows to avoid a bit of the dance with `tcx.hir().local_def_id` and `tcx.hir().local_def_id_to_hir_id` mappings.

38 files changed, 166 insertions, 186 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index f3aeea4b8c9..1b3d3b52cdb 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -133,18 +133,17 @@ impl Clean<ExternalCrate> for CrateNum {
                 .item_ids
                 .iter()
                 .filter_map(|&id| {
-                    let item = cx.tcx.hir().expect_item(id.id);
+                    let item = cx.tcx.hir().item(id);
                     match item.kind {
-                        hir::ItemKind::Mod(_) => as_primitive(Res::Def(
-                            DefKind::Mod,
-                            cx.tcx.hir().local_def_id(id.id).to_def_id(),
-                        )),
+                        hir::ItemKind::Mod(_) => {
+                            as_primitive(Res::Def(DefKind::Mod, id.def_id.to_def_id()))
+                        }
                         hir::ItemKind::Use(ref path, hir::UseKind::Single)
                             if item.vis.node.is_pub() =>
                         {
                             as_primitive(path.res).map(|(_, prim)| {
                                 // Pretend the primitive is local.
-                                (cx.tcx.hir().local_def_id(id.id).to_def_id(), prim)
+                                (id.def_id.to_def_id(), prim)
                             })
                         }
                         _ => None,
@@ -185,18 +184,15 @@ impl Clean<ExternalCrate> for CrateNum {
                 .item_ids
                 .iter()
                 .filter_map(|&id| {
-                    let item = cx.tcx.hir().expect_item(id.id);
+                    let item = cx.tcx.hir().item(id);
                     match item.kind {
-                        hir::ItemKind::Mod(_) => as_keyword(Res::Def(
-                            DefKind::Mod,
-                            cx.tcx.hir().local_def_id(id.id).to_def_id(),
-                        )),
+                        hir::ItemKind::Mod(_) => {
+                            as_keyword(Res::Def(DefKind::Mod, id.def_id.to_def_id()))
+                        }
                         hir::ItemKind::Use(ref path, hir::UseKind::Single)
                             if item.vis.node.is_pub() =>
                         {
-                            as_keyword(path.res).map(|(_, prim)| {
-                                (cx.tcx.hir().local_def_id(id.id).to_def_id(), prim)
-                            })
+                            as_keyword(path.res).map(|(_, prim)| (id.def_id.to_def_id(), prim))
                         }
                         _ => None,
                     }
@@ -912,7 +908,7 @@ fn clean_fn_or_proc_macro(
         }
         None => {
             let mut func = (sig, generics, body_id).clean(cx);
-            let def_id = cx.tcx.hir().local_def_id(item.hir_id).to_def_id();
+            let def_id = item.def_id.to_def_id();
             func.header.constness =
                 if is_const_fn(cx.tcx, def_id) && is_unstable_const_fn(cx.tcx, def_id).is_none() {
                     hir::Constness::Const
@@ -1048,7 +1044,7 @@ impl Clean<TypeKind> for hir::def::DefKind {
 
 impl Clean<Item> for hir::TraitItem<'_> {
     fn clean(&self, cx: &DocContext<'_>) -> Item {
-        let local_did = cx.tcx.hir().local_def_id(self.hir_id).to_def_id();
+        let local_did = self.def_id.to_def_id();
         cx.with_param_env(local_did, || {
             let inner = match self.kind {
                 hir::TraitItemKind::Const(ref ty, default) => {
@@ -1089,7 +1085,7 @@ impl Clean<Item> for hir::TraitItem<'_> {
 
 impl Clean<Item> for hir::ImplItem<'_> {
     fn clean(&self, cx: &DocContext<'_>) -> Item {
-        let local_did = cx.tcx.hir().local_def_id(self.hir_id).to_def_id();
+        let local_did = self.def_id.to_def_id();
         cx.with_param_env(local_did, || {
             let inner = match self.kind {
                 hir::ImplItemKind::Const(ref ty, expr) => {
@@ -1120,7 +1116,7 @@ impl Clean<Item> for hir::ImplItem<'_> {
 
             let what_rustc_thinks =
                 Item::from_def_id_and_parts(local_did, Some(self.ident.name), inner, cx);
-            let parent_item = cx.tcx.hir().expect_item(cx.tcx.hir().get_parent_item(self.hir_id));
+            let parent_item = cx.tcx.hir().expect_item(cx.tcx.hir().get_parent_item(self.hir_id()));
             if let hir::ItemKind::Impl(impl_) = &parent_item.kind {
                 if impl_.of_trait.is_some() {
                     // Trait impl items always inherit the impl's visibility --
@@ -1475,7 +1471,7 @@ impl Clean<Type> for hir::Ty<'_> {
             }
             TyKind::Tup(ref tys) => Tuple(tys.clean(cx)),
             TyKind::OpaqueDef(item_id, _) => {
-                let item = cx.tcx.hir().expect_item(item_id.id);
+                let item = cx.tcx.hir().item(item_id);
                 if let hir::ItemKind::OpaqueTy(ref ty) = item.kind {
                     ImplTrait(ty.bounds.clean(cx))
                 } else {
@@ -1950,8 +1946,8 @@ impl Clean<Vec<Item>> for (&hir::Item<'_>, Option<Symbol>) {
         use hir::ItemKind;
 
         let (item, renamed) = self;
-        let def_id = cx.tcx.hir().local_def_id(item.hir_id).to_def_id();
-        let mut name = renamed.unwrap_or_else(|| cx.tcx.hir().name(item.hir_id));
+        let def_id = item.def_id.to_def_id();
+        let mut name = renamed.unwrap_or_else(|| cx.tcx.hir().name(item.hir_id()));
         cx.with_param_env(def_id, || {
             let kind = match item.kind {
                 ItemKind::Static(ty, mutability, body_id) => {
@@ -1999,7 +1995,7 @@ impl Clean<Vec<Item>> for (&hir::Item<'_>, Option<Symbol>) {
                     fields: variant_data.fields().clean(cx),
                     fields_stripped: false,
                 }),
-                ItemKind::Impl(ref impl_) => return clean_impl(impl_, item.hir_id, cx),
+                ItemKind::Impl(ref impl_) => return clean_impl(impl_, item.hir_id(), cx),
                 // proc macros can have a name set by attributes
                 ItemKind::Fn(ref sig, ref generics, body_id) => {
                     clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
@@ -2107,8 +2103,7 @@ fn clean_extern_crate(
     cx: &DocContext<'_>,
 ) -> Vec<Item> {
     // this is the ID of the `extern crate` statement
-    let def_id = cx.tcx.hir().local_def_id(krate.hir_id);
-    let cnum = cx.tcx.extern_mod_stmt_cnum(def_id).unwrap_or(LOCAL_CRATE);
+    let cnum = cx.tcx.extern_mod_stmt_cnum(krate.def_id).unwrap_or(LOCAL_CRATE);
     // this is the ID of the crate itself
     let crate_def_id = DefId { krate: cnum, index: CRATE_DEF_INDEX };
     let please_inline = krate.vis.node.is_pub()
@@ -2127,7 +2122,7 @@ fn clean_extern_crate(
 
         if let Some(items) = inline::try_inline(
             cx,
-            cx.tcx.parent_module(krate.hir_id).to_def_id(),
+            cx.tcx.parent_module(krate.hir_id()).to_def_id(),
             res,
             name,
             Some(krate.attrs),
@@ -2196,7 +2191,6 @@ fn clean_use_statement(
 
     // Also check whether imports were asked to be inlined, in case we're trying to re-export a
     // crate in Rust 2018+
-    let def_id = cx.tcx.hir().local_def_id(import.hir_id).to_def_id();
     let path = path.clean(cx);
     let inner = if kind == hir::UseKind::Glob {
         if !denied {
@@ -2221,14 +2215,14 @@ fn clean_use_statement(
 
             if let Some(mut items) = inline::try_inline(
                 cx,
-                cx.tcx.parent_module(import.hir_id).to_def_id(),
+                cx.tcx.parent_module(import.hir_id()).to_def_id(),
                 path.res,
                 name,
                 Some(import.attrs),
                 &mut visited,
             ) {
                 items.push(Item::from_def_id_and_parts(
-                    def_id,
+                    import.def_id.to_def_id(),
                     None,
                     ImportItem(Import::new_simple(name, resolve_use_source(cx, path), false)),
                     cx,
@@ -2239,16 +2233,16 @@ fn clean_use_statement(
         Import::new_simple(name, resolve_use_source(cx, path), true)
     };
 
-    vec![Item::from_def_id_and_parts(def_id, None, ImportItem(inner), cx)]
+    vec![Item::from_def_id_and_parts(import.def_id.to_def_id(), None, ImportItem(inner), cx)]
 }
 
 impl Clean<Item> for (&hir::ForeignItem<'_>, Option<Symbol>) {
     fn clean(&self, cx: &DocContext<'_>) -> Item {
         let (item, renamed) = self;
-        cx.with_param_env(cx.tcx.hir().local_def_id(item.hir_id).to_def_id(), || {
+        cx.with_param_env(item.def_id.to_def_id(), || {
             let kind = match item.kind {
                 hir::ForeignItemKind::Fn(ref decl, ref names, ref generics) => {
-                    let abi = cx.tcx.hir().get_foreign_abi(item.hir_id);
+                    let abi = cx.tcx.hir().get_foreign_abi(item.hir_id());
                     let (generics, decl) = enter_impl_trait(cx, || {
                         (generics.clean(cx), (&**decl, &names[..]).clean(cx))
                     });
@@ -2270,7 +2264,7 @@ impl Clean<Item> for (&hir::ForeignItem<'_>, Option<Symbol>) {
             };
 
             Item::from_hir_id_and_parts(
-                item.hir_id,
+                item.hir_id(),
                 Some(renamed.unwrap_or(item.ident.name)),
                 kind,
                 cx,
@@ -2297,7 +2291,7 @@ impl Clean<Item> for (&hir::MacroDef<'_>, Option<Symbol>) {
             )
         } else {
             let vis = item.vis.clean(cx);
-            let def_id = cx.tcx.hir().local_def_id(item.hir_id).to_def_id();
+            let def_id = item.def_id.to_def_id();
 
             if matchers.len() <= 1 {
                 format!(
@@ -2320,7 +2314,7 @@ impl Clean<Item> for (&hir::MacroDef<'_>, Option<Symbol>) {
         };
 
         Item::from_hir_id_and_parts(
-            item.hir_id,
+            item.hir_id(),
             Some(name),
             MacroItem(Macro { source, imported_from: None }),
             cx,
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index a20e9dec33b..d79c47bbe3d 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -479,7 +479,7 @@ crate fn run_global_ctxt(
     // NOTE: This is copy/pasted from typeck/lib.rs and should be kept in sync with those changes.
     tcx.sess.time("item_types_checking", || {
         for &module in tcx.hir().krate().modules.keys() {
-            tcx.ensure().check_mod_item_types(tcx.hir().local_def_id(module));
+            tcx.ensure().check_mod_item_types(module);
         }
     });
     tcx.sess.abort_if_errors();
@@ -488,8 +488,7 @@ crate fn run_global_ctxt(
     });
     tcx.sess.time("check_mod_attrs", || {
         for &module in tcx.hir().krate().modules.keys() {
-            let local_def_id = tcx.hir().local_def_id(module);
-            tcx.ensure().check_mod_attrs(local_def_id);
+            tcx.ensure().check_mod_attrs(module);
         }
     });
 
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index fb4774ae192..c3b9fd5a1dd 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -1050,27 +1050,45 @@ impl<'a, 'hir, 'tcx> intravisit::Visitor<'hir> for HirCollector<'a, 'hir, 'tcx>
             item.ident.to_string()
         };
 
-        self.visit_testable(name, &item.attrs, item.hir_id, item.span, |this| {
+        self.visit_testable(name, &item.attrs, item.hir_id(), item.span, |this| {
             intravisit::walk_item(this, item);
         });
     }
 
     fn visit_trait_item(&mut self, item: &'hir hir::TraitItem<'_>) {
-        self.visit_testable(item.ident.to_string(), &item.attrs, item.hir_id, item.span, |this| {
-            intravisit::walk_trait_item(this, item);
-        });
+        self.visit_testable(
+            item.ident.to_string(),
+            &item.attrs,
+            item.hir_id(),
+            item.span,
+            |this| {
+                intravisit::walk_trait_item(this, item);
+            },
+        );
     }
 
     fn visit_impl_item(&mut self, item: &'hir hir::ImplItem<'_>) {
-        self.visit_testable(item.ident.to_string(), &item.attrs, item.hir_id, item.span, |this| {
-            intravisit::walk_impl_item(this, item);
-        });
+        self.visit_testable(
+            item.ident.to_string(),
+            &item.attrs,
+            item.hir_id(),
+            item.span,
+            |this| {
+                intravisit::walk_impl_item(this, item);
+            },
+        );
     }
 
     fn visit_foreign_item(&mut self, item: &'hir hir::ForeignItem<'_>) {
-        self.visit_testable(item.ident.to_string(), &item.attrs, item.hir_id, item.span, |this| {
-            intravisit::walk_foreign_item(this, item);
-        });
+        self.visit_testable(
+            item.ident.to_string(),
+            &item.attrs,
+            item.hir_id(),
+            item.span,
+            |this| {
+                intravisit::walk_foreign_item(this, item);
+            },
+        );
     }
 
     fn visit_variant(
@@ -1094,7 +1112,7 @@ impl<'a, 'hir, 'tcx> intravisit::Visitor<'hir> for HirCollector<'a, 'hir, 'tcx>
         self.visit_testable(
             macro_def.ident.to_string(),
             &macro_def.attrs,
-            macro_def.hir_id,
+            macro_def.hir_id(),
             macro_def.span,
             |_| (),
         );
diff --git a/src/librustdoc/passes/collect_trait_impls.rs b/src/librustdoc/passes/collect_trait_impls.rs
index 6f992b3a916..0951a9c2c97 100644
--- a/src/librustdoc/passes/collect_trait_impls.rs
+++ b/src/librustdoc/passes/collect_trait_impls.rs
@@ -58,8 +58,8 @@ crate fn collect_trait_impls(krate: Crate, cx: &DocContext<'_>) -> Crate {
     // doesn't work with it anyway, so pull them from the HIR map instead
     let mut extra_attrs = Vec::new();
     for &trait_did in cx.tcx.all_traits(LOCAL_CRATE).iter() {
-        for &impl_node in cx.tcx.hir().trait_impls(trait_did) {
-            let impl_did = cx.tcx.hir().local_def_id(impl_node).to_def_id();
+        for &impl_did in cx.tcx.hir().trait_impls(trait_did) {
+            let impl_did = impl_did.to_def_id();
             cx.tcx.sess.prof.generic_activity("build_local_trait_impl").run(|| {
                 let mut parent = cx.tcx.parent(impl_did);
                 while let Some(did) = parent {
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 7d161ca3648..e92ea55caa7 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -89,7 +89,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             // (since a direct parent isn't necessarily a module, c.f. #77828).
             let macro_parent_def_id = {
                 use rustc_middle::ty::DefIdTree;
-                tcx.parent(tcx.hir().local_def_id(def.hir_id).to_def_id()).unwrap()
+                tcx.parent(def.def_id.to_def_id()).unwrap()
             };
             let macro_parent_path = tcx.def_path(macro_parent_def_id);
             // HACK: rustdoc has no way to lookup `doctree::Module`s by their HirId. Instead,
@@ -132,8 +132,8 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         // Keep track of if there were any private modules in the path.
         let orig_inside_public_path = self.inside_public_path;
         self.inside_public_path &= vis.node.is_pub();
-        for i in m.item_ids {
-            let item = self.cx.tcx.hir().expect_item(i.id);
+        for &i in m.item_ids {
+            let item = self.cx.tcx.hir().item(i);
             self.visit_item(item, None, &mut om);
         }
         self.inside_public_path = orig_inside_public_path;
@@ -231,8 +231,8 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         let ret = match tcx.hir().get(res_hir_id) {
             Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
                 let prev = mem::replace(&mut self.inlining, true);
-                for i in m.item_ids {
-                    let i = self.cx.tcx.hir().expect_item(i.id);
+                for &i in m.item_ids {
+                    let i = self.cx.tcx.hir().item(i);
                     self.visit_item(i, None, om);
                 }
                 self.inlining = prev;
@@ -270,8 +270,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         let name = renamed.unwrap_or(item.ident.name);
 
         if item.vis.node.is_pub() {
-            let def_id = self.cx.tcx.hir().local_def_id(item.hir_id);
-            self.store_path(def_id.to_def_id());
+            self.store_path(item.def_id.to_def_id());
         }
 
         match item.kind {
@@ -305,7 +304,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                     });
                     let ident = if is_glob { None } else { Some(name) };
                     if self.maybe_inline_local(
-                        item.hir_id,
+                        item.hir_id(),
                         path.res,
                         ident,
                         is_glob,
@@ -322,7 +321,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 om.mods.push(self.visit_mod_contents(
                     item.span,
                     &item.vis,
-                    item.hir_id,
+                    item.hir_id(),
                     m,
                     Some(name),
                 ));
diff --git a/src/tools/clippy/clippy_lints/src/copy_iterator.rs b/src/tools/clippy/clippy_lints/src/copy_iterator.rs
index 48899b33899..004bce5f62a 100644
--- a/src/tools/clippy/clippy_lints/src/copy_iterator.rs
+++ b/src/tools/clippy/clippy_lints/src/copy_iterator.rs
@@ -38,7 +38,7 @@ impl<'tcx> LateLintPass<'tcx> for CopyIterator {
             ..
         }) = item.kind
         {
-            let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
+            let ty = cx.tcx.type_of(item.def_id);
 
             if is_copy(cx, ty) && match_path(&trait_ref.path, &paths::ITERATOR) {
                 span_lint_and_note(
diff --git a/src/tools/clippy/clippy_lints/src/derive.rs b/src/tools/clippy/clippy_lints/src/derive.rs
index b1e363663bb..e8510bde9ad 100644
--- a/src/tools/clippy/clippy_lints/src/derive.rs
+++ b/src/tools/clippy/clippy_lints/src/derive.rs
@@ -169,7 +169,7 @@ impl<'tcx> LateLintPass<'tcx> for Derive {
             ..
         }) = item.kind
         {
-            let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
+            let ty = cx.tcx.type_of(item.def_id);
             let is_automatically_derived = is_automatically_derived(&*item.attrs);
 
             check_hash_peq(cx, item.span, trait_ref, ty, is_automatically_derived);
diff --git a/src/tools/clippy/clippy_lints/src/doc.rs b/src/tools/clippy/clippy_lints/src/doc.rs
index 75e71eb1e4c..67b7cf91958 100644
--- a/src/tools/clippy/clippy_lints/src/doc.rs
+++ b/src/tools/clippy/clippy_lints/src/doc.rs
@@ -216,18 +216,17 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
         let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
         match item.kind {
             hir::ItemKind::Fn(ref sig, _, body_id) => {
-                if !(is_entrypoint_fn(cx, cx.tcx.hir().local_def_id(item.hir_id).to_def_id())
+                if !(is_entrypoint_fn(cx, item.def_id.to_def_id())
                     || in_external_macro(cx.tcx.sess, item.span))
                 {
                     let body = cx.tcx.hir().body(body_id);
-                    let impl_item_def_id = cx.tcx.hir().local_def_id(item.hir_id);
                     let mut fpu = FindPanicUnwrap {
                         cx,
-                        typeck_results: cx.tcx.typeck(impl_item_def_id),
+                        typeck_results: cx.tcx.typeck(item.def_id),
                         panic_span: None,
                     };
                     fpu.visit_expr(&body.value);
-                    lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id), fpu.panic_span);
+                    lint_for_missing_headers(cx, item.hir_id(), item.span, sig, headers, Some(body_id), fpu.panic_span);
                 }
             },
             hir::ItemKind::Impl(ref impl_) => {
@@ -247,7 +246,7 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
         let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
         if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
             if !in_external_macro(cx.tcx.sess, item.span) {
-                lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, None, None);
+                lint_for_missing_headers(cx, item.hir_id(), item.span, sig, headers, None, None);
             }
         }
     }
@@ -259,14 +258,13 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
         }
         if let hir::ImplItemKind::Fn(ref sig, body_id) = item.kind {
             let body = cx.tcx.hir().body(body_id);
-            let impl_item_def_id = cx.tcx.hir().local_def_id(item.hir_id);
             let mut fpu = FindPanicUnwrap {
                 cx,
-                typeck_results: cx.tcx.typeck(impl_item_def_id),
+                typeck_results: cx.tcx.typeck(item.def_id),
                 panic_span: None,
             };
             fpu.visit_expr(&body.value);
-            lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id), fpu.panic_span);
+            lint_for_missing_headers(cx, item.hir_id(), item.span, sig, headers, Some(body_id), fpu.panic_span);
         }
     }
 }
diff --git a/src/tools/clippy/clippy_lints/src/empty_enum.rs b/src/tools/clippy/clippy_lints/src/empty_enum.rs
index 853b3afdc3a..077c3b75fb8 100644
--- a/src/tools/clippy/clippy_lints/src/empty_enum.rs
+++ b/src/tools/clippy/clippy_lints/src/empty_enum.rs
@@ -49,9 +49,8 @@ impl<'tcx> LateLintPass<'tcx> for EmptyEnum {
             return;
         }
 
-        let did = cx.tcx.hir().local_def_id(item.hir_id);
         if let ItemKind::Enum(..) = item.kind {
-            let ty = cx.tcx.type_of(did);
+            let ty = cx.tcx.type_of(item.def_id);
             let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
             if adt.variants.is_empty() {
                 span_lint_and_help(
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
index 40e93da8dff..f8ef2a464d5 100644
--- a/src/tools/clippy/clippy_lints/src/escape.rs
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -87,11 +87,11 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
             // find `self` ty for this trait if relevant
             if let ItemKind::Trait(_, _, _, _, items) = item.kind {
                 for trait_item in items {
-                    if trait_item.id.hir_id == hir_id {
+                    if trait_item.id.hir_id() == hir_id {
                         // be sure we have `self` parameter in this function
                         if let AssocItemKind::Fn { has_self: true } = trait_item.kind {
                             trait_self_ty =
-                                Some(TraitRef::identity(cx.tcx, trait_item.id.hir_id.owner.to_def_id()).self_ty());
+                                Some(TraitRef::identity(cx.tcx, trait_item.id.def_id.to_def_id()).self_ty());
                         }
                     }
                 }
diff --git a/src/tools/clippy/clippy_lints/src/exhaustive_items.rs b/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
index e3988d0038c..ab9be3398bf 100644
--- a/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
+++ b/src/tools/clippy/clippy_lints/src/exhaustive_items.rs
@@ -72,7 +72,7 @@ impl LateLintPass<'_> for ExhaustiveItems {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
         if_chain! {
             if let ItemKind::Enum(..) | ItemKind::Struct(..) = item.kind;
-            if cx.access_levels.is_exported(item.hir_id);
+            if cx.access_levels.is_exported(item.hir_id());
             if !item.attrs.iter().any(|a| a.has_name(sym::non_exhaustive));
             then {
                 let (lint, msg) = if let ItemKind::Struct(ref v, ..) = item.kind {
diff --git a/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
index 527905e375d..6d522c7ef33 100644
--- a/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
+++ b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
@@ -52,10 +52,9 @@ declare_lint_pass!(FallibleImplFrom => [FALLIBLE_IMPL_FROM]);
 impl<'tcx> LateLintPass<'tcx> for FallibleImplFrom {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
         // check for `impl From<???> for ..`
-        let impl_def_id = cx.tcx.hir().local_def_id(item.hir_id);
         if_chain! {
             if let hir::ItemKind::Impl(impl_) = &item.kind;
-            if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_def_id);
+            if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(item.def_id);
             if cx.tcx.is_diagnostic_item(sym::from_trait, impl_trait_ref.def_id);
             then {
                 lint_impl_body(cx, item.span, impl_.items);
@@ -117,10 +116,9 @@ fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_items: &[h
             then {
                 // check the body for `begin_panic` or `unwrap`
                 let body = cx.tcx.hir().body(body_id);
-                let impl_item_def_id = cx.tcx.hir().local_def_id(impl_item.id.hir_id);
                 let mut fpu = FindPanicUnwrap {
                     lcx: cx,
-                    typeck_results: cx.tcx.typeck(impl_item_def_id),
+                    typeck_results: cx.tcx.typeck(impl_item.id.def_id),
                     result: Vec::new(),
                 };
                 fpu.visit_expr(&body.value);
diff --git a/src/tools/clippy/clippy_lints/src/from_over_into.rs b/src/tools/clippy/clippy_lints/src/from_over_into.rs
index b010abda24d..b644bb07990 100644
--- a/src/tools/clippy/clippy_lints/src/from_over_into.rs
+++ b/src/tools/clippy/clippy_lints/src/from_over_into.rs
@@ -60,10 +60,9 @@ impl LateLintPass<'_> for FromOverInto {
             return;
         }
 
-        let impl_def_id = cx.tcx.hir().local_def_id(item.hir_id);
         if_chain! {
             if let hir::ItemKind::Impl{ .. } = &item.kind;
-            if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_def_id);
+            if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(item.def_id);
             if match_def_path(cx, impl_trait_ref.def_id, &INTO);
 
             then {
diff --git a/src/tools/clippy/clippy_lints/src/functions.rs b/src/tools/clippy/clippy_lints/src/functions.rs
index 71a146cc298..0c6bf8bbdf2 100644
--- a/src/tools/clippy/clippy_lints/src/functions.rs
+++ b/src/tools/clippy/clippy_lints/src/functions.rs
@@ -283,13 +283,13 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
         let attr = must_use_attr(&item.attrs);
         if let hir::ItemKind::Fn(ref sig, ref _generics, ref body_id) = item.kind {
-            let is_public = cx.access_levels.is_exported(item.hir_id);
+            let is_public = cx.access_levels.is_exported(item.hir_id());
             let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
             if is_public {
                 check_result_unit_err(cx, &sig.decl, item.span, fn_header_span);
             }
             if let Some(attr) = attr {
-                check_needless_must_use(cx, &sig.decl, item.hir_id, item.span, fn_header_span, attr);
+                check_needless_must_use(cx, &sig.decl, item.hir_id(), item.span, fn_header_span, attr);
                 return;
             }
             if is_public && !is_proc_macro(cx.sess(), &item.attrs) && attr_by_name(&item.attrs, "no_mangle").is_none() {
@@ -298,7 +298,7 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
                     &sig.decl,
                     cx.tcx.hir().body(*body_id),
                     item.span,
-                    item.hir_id,
+                    item.hir_id(),
                     item.span.with_hi(sig.decl.output.span().hi()),
                     "this function could have a `#[must_use]` attribute",
                 );
@@ -308,24 +308,24 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'_>) {
         if let hir::ImplItemKind::Fn(ref sig, ref body_id) = item.kind {
-            let is_public = cx.access_levels.is_exported(item.hir_id);
+            let is_public = cx.access_levels.is_exported(item.hir_id());
             let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
-            if is_public && trait_ref_of_method(cx, item.hir_id).is_none() {
+            if is_public && trait_ref_of_method(cx, item.hir_id()).is_none() {
                 check_result_unit_err(cx, &sig.decl, item.span, fn_header_span);
             }
             let attr = must_use_attr(&item.attrs);
             if let Some(attr) = attr {
-                check_needless_must_use(cx, &sig.decl, item.hir_id, item.span, fn_header_span, attr);
+                check_needless_must_use(cx, &sig.decl, item.hir_id(), item.span, fn_header_span, attr);
             } else if is_public
                 && !is_proc_macro(cx.sess(), &item.attrs)
-                && trait_ref_of_method(cx, item.hir_id).is_none()
+                && trait_ref_of_method(cx, item.hir_id()).is_none()
             {
                 check_must_use_candidate(
                     cx,
                     &sig.decl,
                     cx.tcx.hir().body(*body_id),
                     item.span,
-                    item.hir_id,
+                    item.hir_id(),
                     item.span.with_hi(sig.decl.output.span().hi()),
                     "this method could have a `#[must_use]` attribute",
                 );
@@ -339,7 +339,7 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
             if sig.header.abi == Abi::Rust {
                 self.check_arg_number(cx, &sig.decl, item.span.with_hi(sig.decl.output.span().hi()));
             }
-            let is_public = cx.access_levels.is_exported(item.hir_id);
+            let is_public = cx.access_levels.is_exported(item.hir_id());
             let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
             if is_public {
                 check_result_unit_err(cx, &sig.decl, item.span, fn_header_span);
@@ -347,11 +347,11 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
 
             let attr = must_use_attr(&item.attrs);
             if let Some(attr) = attr {
-                check_needless_must_use(cx, &sig.decl, item.hir_id, item.span, fn_header_span, attr);
+                check_needless_must_use(cx, &sig.decl, item.hir_id(), item.span, fn_header_span, attr);
             }
             if let hir::TraitFn::Provided(eid) = *eid {
                 let body = cx.tcx.hir().body(eid);
-                Self::check_raw_ptr(cx, sig.header.unsafety, &sig.decl, body, item.hir_id);
+                Self::check_raw_ptr(cx, sig.header.unsafety, &sig.decl, body, item.hir_id());
 
                 if attr.is_none() && is_public && !is_proc_macro(cx.sess(), &item.attrs) {
                     check_must_use_candidate(
@@ -359,7 +359,7 @@ impl<'tcx> LateLintPass<'tcx> for Functions {
                         &sig.decl,
                         body,
                         item.span,
-                        item.hir_id,
+                        item.hir_id(),
                         item.span.with_hi(sig.decl.output.span().hi()),
                         "this method could have a `#[must_use]` attribute",
                     );
diff --git a/src/tools/clippy/clippy_lints/src/inherent_impl.rs b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
index ea26c84cde1..005c461f105 100644
--- a/src/tools/clippy/clippy_lints/src/inherent_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
@@ -59,20 +59,15 @@ impl<'tcx> LateLintPass<'tcx> for MultipleInherentImpl {
             // but filter out implementations that have generic params (type or lifetime)
             // or are derived from a macro
             if !in_macro(item.span) && generics.params.is_empty() {
-                self.impls.insert(item.hir_id.owner.to_def_id(), item.span);
+                self.impls.insert(item.def_id.to_def_id(), item.span);
             }
         }
     }
 
     fn check_crate_post(&mut self, cx: &LateContext<'tcx>, krate: &'tcx Crate<'_>) {
-        if let Some(item) = krate.items.values().next() {
+        if !krate.items.is_empty() {
             // Retrieve all inherent implementations from the crate, grouped by type
-            for impls in cx
-                .tcx
-                .crate_inherent_impls(item.hir_id.owner.to_def_id().krate)
-                .inherent_impls
-                .values()
-            {
+            for impls in cx.tcx.crate_inherent_impls(def_id::LOCAL_CRATE).inherent_impls.values() {
                 // Filter out implementations that have generic params (type or lifetime)
                 let mut impl_spans = impls.iter().filter_map(|impl_def| self.impls.get(impl_def));
                 if let Some(initial_span) = impl_spans.next() {
diff --git a/src/tools/clippy/clippy_lints/src/inherent_to_string.rs b/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
index b723d06a688..76e7a4992d3 100644
--- a/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
+++ b/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
@@ -108,10 +108,10 @@ impl<'tcx> LateLintPass<'tcx> for InherentToString {
             if decl.inputs.len() == 1;
 
             // Check if return type is String
-            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id), sym::string_type);
+            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::string_type);
 
             // Filters instances of to_string which are required by a trait
-            if trait_ref_of_method(cx, impl_item.hir_id).is_none();
+            if trait_ref_of_method(cx, impl_item.hir_id()).is_none();
 
             then {
                 show_lint(cx, impl_item);
@@ -124,8 +124,7 @@ 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`!");
 
     // Get the real type of 'self'
-    let fn_def_id = cx.tcx.hir().local_def_id(item.hir_id);
-    let self_type = cx.tcx.fn_sig(fn_def_id).input(0);
+    let self_type = cx.tcx.fn_sig(item.def_id).input(0);
     let self_type = self_type.skip_binder().peel_refs();
 
     // Emit either a warning or an error
diff --git a/src/tools/clippy/clippy_lints/src/large_enum_variant.rs b/src/tools/clippy/clippy_lints/src/large_enum_variant.rs
index ad9b4f357a7..ab4cb33612d 100644
--- a/src/tools/clippy/clippy_lints/src/large_enum_variant.rs
+++ b/src/tools/clippy/clippy_lints/src/large_enum_variant.rs
@@ -62,9 +62,8 @@ impl<'tcx> LateLintPass<'tcx> for LargeEnumVariant {
         if in_external_macro(cx.tcx.sess, item.span) {
             return;
         }
-        let did = cx.tcx.hir().local_def_id(item.hir_id);
         if let ItemKind::Enum(ref def, _) = item.kind {
-            let ty = cx.tcx.type_of(did);
+            let ty = cx.tcx.type_of(item.def_id);
             let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
 
             let mut largest_variant: Option<(_, _)> = None;
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index e95caf6a35f..dab3e0565ca 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -159,10 +159,7 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
     fn is_named_self(cx: &LateContext<'_>, item: &TraitItemRef, name: &str) -> bool {
         item.ident.name.as_str() == name
             && if let AssocItemKind::Fn { has_self } = item.kind {
-                has_self && {
-                    let did = cx.tcx.hir().local_def_id(item.id.hir_id);
-                    cx.tcx.fn_sig(did).inputs().skip_binder().len() == 1
-                }
+                has_self && { cx.tcx.fn_sig(item.id.def_id).inputs().skip_binder().len() == 1 }
             } else {
                 false
             }
@@ -177,10 +174,9 @@ fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, trait_items
         }
     }
 
-    if cx.access_levels.is_exported(visited_trait.hir_id) && trait_items.iter().any(|i| is_named_self(cx, i, "len")) {
+    if cx.access_levels.is_exported(visited_trait.hir_id()) && trait_items.iter().any(|i| is_named_self(cx, i, "len")) {
         let mut current_and_super_traits = FxHashSet::default();
-        let visited_trait_def_id = cx.tcx.hir().local_def_id(visited_trait.hir_id);
-        fill_trait_set(visited_trait_def_id.to_def_id(), &mut current_and_super_traits, cx);
+        fill_trait_set(visited_trait.def_id.to_def_id(), &mut current_and_super_traits, cx);
 
         let is_empty_method_found = current_and_super_traits
             .iter()
@@ -210,17 +206,14 @@ fn check_impl_items(cx: &LateContext<'_>, item: &Item<'_>, impl_items: &[ImplIte
     fn is_named_self(cx: &LateContext<'_>, item: &ImplItemRef<'_>, name: &str) -> bool {
         item.ident.name.as_str() == name
             && if let AssocItemKind::Fn { has_self } = item.kind {
-                has_self && {
-                    let did = cx.tcx.hir().local_def_id(item.id.hir_id);
-                    cx.tcx.fn_sig(did).inputs().skip_binder().len() == 1
-                }
+                has_self && cx.tcx.fn_sig(item.id.def_id).inputs().skip_binder().len() == 1
             } else {
                 false
             }
     }
 
     let is_empty = if let Some(is_empty) = impl_items.iter().find(|i| is_named_self(cx, i, "is_empty")) {
-        if cx.access_levels.is_exported(is_empty.id.hir_id) {
+        if cx.access_levels.is_exported(is_empty.id.hir_id()) {
             return;
         }
         "a private"
@@ -229,9 +222,8 @@ fn check_impl_items(cx: &LateContext<'_>, item: &Item<'_>, impl_items: &[ImplIte
     };
 
     if let Some(i) = impl_items.iter().find(|i| is_named_self(cx, i, "len")) {
-        if cx.access_levels.is_exported(i.id.hir_id) {
-            let def_id = cx.tcx.hir().local_def_id(item.hir_id);
-            let ty = cx.tcx.type_of(def_id);
+        if cx.access_levels.is_exported(i.id.hir_id()) {
+            let ty = cx.tcx.type_of(item.def_id);
 
             span_lint(
                 cx,
diff --git a/src/tools/clippy/clippy_lints/src/lifetimes.rs b/src/tools/clippy/clippy_lints/src/lifetimes.rs
index e84c8b4e5b3..50e6383263d 100644
--- a/src/tools/clippy/clippy_lints/src/lifetimes.rs
+++ b/src/tools/clippy/clippy_lints/src/lifetimes.rs
@@ -87,7 +87,7 @@ impl<'tcx> LateLintPass<'tcx> for Lifetimes {
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) {
         if let ImplItemKind::Fn(ref sig, id) = item.kind {
-            let report_extra_lifetimes = trait_ref_of_method(cx, item.hir_id).is_none();
+            let report_extra_lifetimes = trait_ref_of_method(cx, item.hir_id()).is_none();
             check_fn_inner(
                 cx,
                 &sig.decl,
@@ -375,7 +375,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
         match ty.kind {
             TyKind::OpaqueDef(item, _) => {
                 let map = self.cx.tcx.hir();
-                let item = map.expect_item(item.id);
+                let item = map.item(item);
                 walk_item(self, item);
                 walk_ty(self, ty);
             },
diff --git a/src/tools/clippy/clippy_lints/src/manual_async_fn.rs b/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
index 89f5b2ff311..2e2e693592c 100644
--- a/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
+++ b/src/tools/clippy/clippy_lints/src/manual_async_fn.rs
@@ -102,7 +102,7 @@ fn future_trait_ref<'tcx>(
 ) -> Option<(&'tcx TraitRef<'tcx>, Vec<LifetimeName>)> {
     if_chain! {
         if let TyKind::OpaqueDef(item_id, bounds) = ty.kind;
-        let item = cx.tcx.hir().item(item_id.id);
+        let item = cx.tcx.hir().item(item_id);
         if let ItemKind::OpaqueTy(opaque) = &item.kind;
         if let Some(trait_ref) = opaque.bounds.iter().find_map(|bound| {
             if let GenericBound::Trait(poly, _) = bound {
diff --git a/src/tools/clippy/clippy_lints/src/methods/mod.rs b/src/tools/clippy/clippy_lints/src/methods/mod.rs
index 0918843294d..55660cc95a8 100644
--- a/src/tools/clippy/clippy_lints/src/methods/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/mod.rs
@@ -1685,10 +1685,9 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
             return;
         }
         let name = impl_item.ident.name.as_str();
-        let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id);
+        let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id());
         let item = cx.tcx.hir().expect_item(parent);
-        let def_id = cx.tcx.hir().local_def_id(item.hir_id);
-        let self_ty = cx.tcx.type_of(def_id);
+        let self_ty = cx.tcx.type_of(item.def_id);
 
         // if this impl block implements a trait, lint in trait definition instead
         if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = item.kind {
@@ -1699,8 +1698,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
             if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind;
             if let Some(first_arg) = iter_input_pats(&sig.decl, cx.tcx.hir().body(id)).next();
 
-            let method_def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
-            let method_sig = cx.tcx.fn_sig(method_def_id);
+            let method_sig = cx.tcx.fn_sig(impl_item.def_id);
             let method_sig = cx.tcx.erase_late_bound_regions(method_sig);
 
             let first_arg_ty = &method_sig.inputs().iter().next();
@@ -1709,7 +1707,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
             if let Some(first_arg_ty) = first_arg_ty;
 
             then {
-                if cx.access_levels.is_exported(impl_item.hir_id) {
+                if cx.access_levels.is_exported(impl_item.hir_id()) {
                     // check missing trait implementations
                     for method_config in &TRAIT_METHODS {
                         if name == method_config.method_name &&
@@ -1751,7 +1749,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         }
 
         if let hir::ImplItemKind::Fn(_, _) = impl_item.kind {
-            let ret_ty = return_ty(cx, impl_item.hir_id);
+            let ret_ty = return_ty(cx, impl_item.hir_id());
 
             // walk the return type and check for Self (this does not check associated types)
             if contains_ty(ret_ty, self_ty) {
@@ -1792,7 +1790,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
             if let Some(first_arg_ty) = sig.decl.inputs.iter().next();
             let first_arg_span = first_arg_ty.span;
             let first_arg_ty = hir_ty_to_ty(cx.tcx, first_arg_ty);
-            let self_ty = TraitRef::identity(cx.tcx, item.hir_id.owner.to_def_id()).self_ty();
+            let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty();
 
             then {
                 lint_wrong_self_convention(cx, &item.ident.name.as_str(), false, self_ty, first_arg_ty, first_arg_span);
@@ -1802,8 +1800,8 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         if_chain! {
             if item.ident.name == sym::new;
             if let TraitItemKind::Fn(_, _) = item.kind;
-            let ret_ty = return_ty(cx, item.hir_id);
-            let self_ty = TraitRef::identity(cx.tcx, item.hir_id.owner.to_def_id()).self_ty();
+            let ret_ty = return_ty(cx, item.hir_id());
+            let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty();
             if !contains_ty(ret_ty, self_ty);
 
             then {
diff --git a/src/tools/clippy/clippy_lints/src/missing_doc.rs b/src/tools/clippy/clippy_lints/src/missing_doc.rs
index 0e49eaab436..761b9261772 100644
--- a/src/tools/clippy/clippy_lints/src/missing_doc.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_doc.rs
@@ -135,8 +135,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
             hir::ItemKind::Fn(..) => {
                 // ignore main()
                 if it.ident.name == sym::main {
-                    let def_id = it.hir_id.owner;
-                    let def_key = cx.tcx.hir().def_key(def_id);
+                    let def_key = cx.tcx.hir().def_key(it.def_id);
                     if def_key.parent == Some(hir::def_id::CRATE_DEF_INDEX) {
                         return;
                     }
@@ -159,23 +158,20 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
             | hir::ItemKind::Use(..) => return,
         };
 
-        let def_id = cx.tcx.hir().local_def_id(it.hir_id);
-        let (article, desc) = cx.tcx.article_and_description(def_id.to_def_id());
+        let (article, desc) = cx.tcx.article_and_description(it.def_id.to_def_id());
 
         self.check_missing_docs_attrs(cx, &it.attrs, it.span, article, desc);
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'tcx>, trait_item: &'tcx hir::TraitItem<'_>) {
-        let def_id = cx.tcx.hir().local_def_id(trait_item.hir_id);
-        let (article, desc) = cx.tcx.article_and_description(def_id.to_def_id());
+        let (article, desc) = cx.tcx.article_and_description(trait_item.def_id.to_def_id());
 
         self.check_missing_docs_attrs(cx, &trait_item.attrs, trait_item.span, article, desc);
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx hir::ImplItem<'_>) {
         // If the method is an impl for a trait, don't doc.
-        let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
-        match cx.tcx.associated_item(def_id).container {
+        match cx.tcx.associated_item(impl_item.def_id).container {
             ty::TraitContainer(_) => return,
             ty::ImplContainer(cid) => {
                 if cx.tcx.impl_trait_ref(cid).is_some() {
@@ -184,7 +180,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
             },
         }
 
-        let (article, desc) = cx.tcx.article_and_description(def_id.to_def_id());
+        let (article, desc) = cx.tcx.article_and_description(impl_item.def_id.to_def_id());
         self.check_missing_docs_attrs(cx, &impl_item.attrs, impl_item.span, article, desc);
     }
 
diff --git a/src/tools/clippy/clippy_lints/src/missing_inline.rs b/src/tools/clippy/clippy_lints/src/missing_inline.rs
index 913d9daff46..47d7c5306c4 100644
--- a/src/tools/clippy/clippy_lints/src/missing_inline.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_inline.rs
@@ -87,7 +87,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingInline {
             return;
         }
 
-        if !cx.access_levels.is_exported(it.hir_id) {
+        if !cx.access_levels.is_exported(it.hir_id()) {
             return;
         }
         match it.kind {
@@ -107,7 +107,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingInline {
                                 // trait method with default body needs inline in case
                                 // an impl is not provided
                                 let desc = "a default trait method";
-                                let item = cx.tcx.hir().expect_trait_item(tit.id.hir_id);
+                                let item = cx.tcx.hir().trait_item(tit.id);
                                 check_missing_inline_attrs(cx, &item.attrs, item.span, desc);
                             }
                         },
@@ -138,7 +138,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingInline {
         }
 
         // If the item being implemented is not exported, then we don't need #[inline]
-        if !cx.access_levels.is_exported(impl_item.hir_id) {
+        if !cx.access_levels.is_exported(impl_item.hir_id()) {
             return;
         }
 
@@ -147,14 +147,13 @@ impl<'tcx> LateLintPass<'tcx> for MissingInline {
             hir::ImplItemKind::Const(..) | hir::ImplItemKind::TyAlias(_) => return,
         };
 
-        let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
-        let trait_def_id = match cx.tcx.associated_item(def_id).container {
+        let trait_def_id = match cx.tcx.associated_item(impl_item.def_id).container {
             TraitContainer(cid) => Some(cid),
             ImplContainer(cid) => cx.tcx.impl_trait_ref(cid).map(|t| t.def_id),
         };
 
         if let Some(trait_def_id) = trait_def_id {
-            if trait_def_id.is_local() && !cx.access_levels.is_exported(impl_item.hir_id) {
+            if trait_def_id.is_local() && !cx.access_levels.is_exported(impl_item.hir_id()) {
                 // If a trait is being implemented for an item, and the
                 // trait is not exported, we don't need #[inline]
                 return;
diff --git a/src/tools/clippy/clippy_lints/src/mut_key.rs b/src/tools/clippy/clippy_lints/src/mut_key.rs
index 11044e0c2fb..908b7bb7ce0 100644
--- a/src/tools/clippy/clippy_lints/src/mut_key.rs
+++ b/src/tools/clippy/clippy_lints/src/mut_key.rs
@@ -57,21 +57,21 @@ declare_lint_pass!(MutableKeyType => [ MUTABLE_KEY_TYPE ]);
 impl<'tcx> LateLintPass<'tcx> for MutableKeyType {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
         if let hir::ItemKind::Fn(ref sig, ..) = item.kind {
-            check_sig(cx, item.hir_id, &sig.decl);
+            check_sig(cx, item.hir_id(), &sig.decl);
         }
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'tcx>) {
         if let hir::ImplItemKind::Fn(ref sig, ..) = item.kind {
-            if trait_ref_of_method(cx, item.hir_id).is_none() {
-                check_sig(cx, item.hir_id, &sig.decl);
+            if trait_ref_of_method(cx, item.hir_id()).is_none() {
+                check_sig(cx, item.hir_id(), &sig.decl);
             }
         }
     }
 
     fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'tcx>) {
         if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
-            check_sig(cx, item.hir_id, &sig.decl);
+            check_sig(cx, item.hir_id(), &sig.decl);
         }
     }
 
diff --git a/src/tools/clippy/clippy_lints/src/needless_borrow.rs b/src/tools/clippy/clippy_lints/src/needless_borrow.rs
index f1c06692e30..1453ea6e897 100644
--- a/src/tools/clippy/clippy_lints/src/needless_borrow.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_borrow.rs
@@ -5,11 +5,12 @@
 use crate::utils::{is_automatically_derived, snippet_opt, span_lint_and_then};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{BindingAnnotation, BorrowKind, Expr, ExprKind, HirId, Item, Mutability, Pat, PatKind};
+use rustc_hir::{BindingAnnotation, BorrowKind, Expr, ExprKind, Item, Mutability, Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::def_id::LocalDefId;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for address of operations (`&`) that are going to
@@ -35,7 +36,7 @@ declare_clippy_lint! {
 
 #[derive(Default)]
 pub struct NeedlessBorrow {
-    derived_item: Option<HirId>,
+    derived_item: Option<LocalDefId>,
 }
 
 impl_lint_pass!(NeedlessBorrow => [NEEDLESS_BORROW]);
@@ -117,13 +118,13 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessBorrow {
     fn check_item(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if is_automatically_derived(item.attrs) {
             debug_assert!(self.derived_item.is_none());
-            self.derived_item = Some(item.hir_id);
+            self.derived_item = Some(item.def_id);
         }
     }
 
     fn check_item_post(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let Some(id) = self.derived_item {
-            if item.hir_id == id {
+            if item.def_id == id {
                 self.derived_item = None;
             }
         }
diff --git a/src/tools/clippy/clippy_lints/src/new_without_default.rs b/src/tools/clippy/clippy_lints/src/new_without_default.rs
index bd3dac663fe..de2899c3462 100644
--- a/src/tools/clippy/clippy_lints/src/new_without_default.rs
+++ b/src/tools/clippy/clippy_lints/src/new_without_default.rs
@@ -72,7 +72,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                     }
                     if let hir::ImplItemKind::Fn(ref sig, _) = impl_item.kind {
                         let name = impl_item.ident.name;
-                        let id = impl_item.hir_id;
+                        let id = impl_item.hir_id();
                         if sig.header.constness == hir::Constness::Const {
                             // can't be implemented by default
                             return;
diff --git a/src/tools/clippy/clippy_lints/src/non_copy_const.rs b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
index 0b2262d8490..8aebce67917 100644
--- a/src/tools/clippy/clippy_lints/src/non_copy_const.rs
+++ b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
@@ -271,7 +271,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx ImplItem<'_>) {
         if let ImplItemKind::Const(hir_ty, body_id) = &impl_item.kind {
-            let item_hir_id = cx.tcx.hir().get_parent_node(impl_item.hir_id);
+            let item_hir_id = cx.tcx.hir().get_parent_node(impl_item.hir_id());
             let item = cx.tcx.hir().expect_item(item_hir_id);
 
             match &item.kind {
diff --git a/src/tools/clippy/clippy_lints/src/partialeq_ne_impl.rs b/src/tools/clippy/clippy_lints/src/partialeq_ne_impl.rs
index ed314937ce8..3d6129aa78d 100644
--- a/src/tools/clippy/clippy_lints/src/partialeq_ne_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/partialeq_ne_impl.rs
@@ -44,7 +44,7 @@ impl<'tcx> LateLintPass<'tcx> for PartialEqNeImpl {
                         span_lint_hir(
                             cx,
                             PARTIALEQ_NE_IMPL,
-                            impl_item.id.hir_id,
+                            impl_item.id.hir_id(),
                             impl_item.span,
                             "re-implementing `PartialEq::ne` is unnecessary",
                         );
diff --git a/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs b/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs
index d96a9b025f0..b9ba32001b5 100644
--- a/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs
+++ b/src/tools/clippy/clippy_lints/src/pass_by_ref_or_value.rs
@@ -206,7 +206,7 @@ impl<'tcx> LateLintPass<'tcx> for PassByRefOrValue {
         }
 
         if let hir::TraitItemKind::Fn(method_sig, _) = &item.kind {
-            self.check_poly_fn(cx, item.hir_id, &*method_sig.decl, None);
+            self.check_poly_fn(cx, item.hir_id(), &*method_sig.decl, None);
         }
     }
 
diff --git a/src/tools/clippy/clippy_lints/src/ptr.rs b/src/tools/clippy/clippy_lints/src/ptr.rs
index b5aa3411140..de2fb8decb7 100644
--- a/src/tools/clippy/clippy_lints/src/ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/ptr.rs
@@ -124,19 +124,19 @@ declare_lint_pass!(Ptr => [PTR_ARG, CMP_NULL, MUT_FROM_REF]);
 impl<'tcx> LateLintPass<'tcx> for Ptr {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if let ItemKind::Fn(ref sig, _, body_id) = item.kind {
-            check_fn(cx, &sig.decl, item.hir_id, Some(body_id));
+            check_fn(cx, &sig.decl, item.hir_id(), Some(body_id));
         }
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) {
         if let ImplItemKind::Fn(ref sig, body_id) = item.kind {
-            let parent_item = cx.tcx.hir().get_parent_item(item.hir_id);
+            let parent_item = cx.tcx.hir().get_parent_item(item.hir_id());
             if let Some(Node::Item(it)) = cx.tcx.hir().find(parent_item) {
                 if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = it.kind {
                     return; // ignore trait impls
                 }
             }
-            check_fn(cx, &sig.decl, item.hir_id, Some(body_id));
+            check_fn(cx, &sig.decl, item.hir_id(), Some(body_id));
         }
     }
 
@@ -147,7 +147,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
             } else {
                 None
             };
-            check_fn(cx, &sig.decl, item.hir_id, body_id);
+            check_fn(cx, &sig.decl, item.hir_id(), body_id);
         }
     }
 
diff --git a/src/tools/clippy/clippy_lints/src/redundant_pub_crate.rs b/src/tools/clippy/clippy_lints/src/redundant_pub_crate.rs
index acd9047ace6..c876bae2303 100644
--- a/src/tools/clippy/clippy_lints/src/redundant_pub_crate.rs
+++ b/src/tools/clippy/clippy_lints/src/redundant_pub_crate.rs
@@ -42,11 +42,10 @@ impl_lint_pass!(RedundantPubCrate => [REDUNDANT_PUB_CRATE]);
 impl<'tcx> LateLintPass<'tcx> for RedundantPubCrate {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'tcx>) {
         if let VisibilityKind::Crate { .. } = item.vis.node {
-            if !cx.access_levels.is_exported(item.hir_id) {
+            if !cx.access_levels.is_exported(item.hir_id()) {
                 if let Some(false) = self.is_exported.last() {
                     let span = item.span.with_hi(item.ident.span.hi());
-                    let def_id = cx.tcx.hir().local_def_id(item.hir_id);
-                    let descr = cx.tcx.def_kind(def_id).descr(def_id.to_def_id());
+                    let descr = cx.tcx.def_kind(item.def_id).descr(item.def_id.to_def_id());
                     span_lint_and_then(
                         cx,
                         REDUNDANT_PUB_CRATE,
@@ -66,7 +65,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantPubCrate {
         }
 
         if let ItemKind::Mod { .. } = item.kind {
-            self.is_exported.push(cx.access_levels.is_exported(item.hir_id));
+            self.is_exported.push(cx.access_levels.is_exported(item.hir_id()));
         }
     }
 
diff --git a/src/tools/clippy/clippy_lints/src/types.rs b/src/tools/clippy/clippy_lints/src/types.rs
index 58af5b12c37..05754503163 100644
--- a/src/tools/clippy/clippy_lints/src/types.rs
+++ b/src/tools/clippy/clippy_lints/src/types.rs
@@ -1106,7 +1106,9 @@ fn is_empty_block(expr: &Expr<'_>) -> bool {
         expr.kind,
         ExprKind::Block(
             Block {
-                stmts: &[], expr: None, ..
+                stmts: &[],
+                expr: None,
+                ..
             },
             _,
         )
@@ -2565,7 +2567,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitHasher {
             }
         }
 
-        if !cx.access_levels.is_exported(item.hir_id) {
+        if !cx.access_levels.is_exported(item.hir_id()) {
             return;
         }
 
diff --git a/src/tools/clippy/clippy_lints/src/unused_self.rs b/src/tools/clippy/clippy_lints/src/unused_self.rs
index 5349c4f7eb8..73c64b80840 100644
--- a/src/tools/clippy/clippy_lints/src/unused_self.rs
+++ b/src/tools/clippy/clippy_lints/src/unused_self.rs
@@ -44,10 +44,9 @@ impl<'tcx> LateLintPass<'tcx> for UnusedSelf {
         if impl_item.span.from_expansion() {
             return;
         }
-        let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id);
+        let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id());
         let parent_item = cx.tcx.hir().expect_item(parent);
-        let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
-        let assoc_item = cx.tcx.associated_item(def_id);
+        let assoc_item = cx.tcx.associated_item(impl_item.def_id);
         if_chain! {
             if let ItemKind::Impl(Impl { of_trait: None, .. }) = parent_item.kind;
             if assoc_item.fn_has_self_parameter;
diff --git a/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs b/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs
index fde31029330..8cb7429849d 100644
--- a/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs
+++ b/src/tools/clippy/clippy_lints/src/unwrap_in_result.rs
@@ -57,8 +57,8 @@ impl<'tcx> LateLintPass<'tcx> for UnwrapInResult {
             // first check if it's a method or function
             if let hir::ImplItemKind::Fn(ref _signature, _) = impl_item.kind;
             // checking if its return type is `result` or `option`
-            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id), sym::result_type)
-                || is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id), sym::option_type);
+            if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::result_type)
+                || is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id()), sym::option_type);
             then {
                 lint_impl_body(cx, impl_item.span, impl_item);
             }
@@ -114,10 +114,9 @@ fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_item: &'tc
         if let ImplItemKind::Fn(_, body_id) = impl_item.kind;
         then {
             let body = cx.tcx.hir().body(body_id);
-            let impl_item_def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
             let mut fpu = FindExpectUnwrap {
                 lcx: cx,
-                typeck_results: cx.tcx.typeck(impl_item_def_id),
+                typeck_results: cx.tcx.typeck(impl_item.def_id),
                 result: Vec::new(),
             };
             fpu.visit_expr(&body.value);
diff --git a/src/tools/clippy/clippy_lints/src/use_self.rs b/src/tools/clippy/clippy_lints/src/use_self.rs
index 72d1ca73929..f2ff8c959c2 100644
--- a/src/tools/clippy/clippy_lints/src/use_self.rs
+++ b/src/tools/clippy/clippy_lints/src/use_self.rs
@@ -196,8 +196,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                         item_path,
                         cx,
                     };
-                    let impl_def_id = cx.tcx.hir().local_def_id(item.hir_id);
-                    let impl_trait_ref = cx.tcx.impl_trait_ref(impl_def_id);
+                    let impl_trait_ref = cx.tcx.impl_trait_ref(item.def_id);
 
                     if let Some(impl_trait_ref) = impl_trait_ref {
                         for impl_item_ref in impl_.items {
diff --git a/src/tools/clippy/clippy_lints/src/utils/author.rs b/src/tools/clippy/clippy_lints/src/utils/author.rs
index ca60d335262..6e3d4fde107 100644
--- a/src/tools/clippy/clippy_lints/src/utils/author.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/author.rs
@@ -130,7 +130,7 @@ impl<'tcx> LateLintPass<'tcx> for Author {
     }
 
     fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx hir::Stmt<'_>) {
-        if !has_attr(cx.sess(), stmt.kind.attrs(|id| cx.tcx.hir().item(id.id))) {
+        if !has_attr(cx.sess(), stmt.kind.attrs(|id| cx.tcx.hir().item(id))) {
             return;
         }
         prelude();
diff --git a/src/tools/clippy/clippy_lints/src/utils/inspector.rs b/src/tools/clippy/clippy_lints/src/utils/inspector.rs
index 9bec24be9e4..9c1d98cd707 100644
--- a/src/tools/clippy/clippy_lints/src/utils/inspector.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/inspector.rs
@@ -109,7 +109,7 @@ impl<'tcx> LateLintPass<'tcx> for DeepCodeInspector {
     }
 
     fn check_stmt(&mut self, cx: &LateContext<'tcx>, stmt: &'tcx hir::Stmt<'_>) {
-        if !has_attr(cx.sess(), stmt.kind.attrs(|id| cx.tcx.hir().item(id.id))) {
+        if !has_attr(cx.sess(), stmt.kind.attrs(|id| cx.tcx.hir().item(id))) {
             return;
         }
         match stmt.kind {
@@ -370,7 +370,7 @@ fn print_expr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, indent: usize) {
 }
 
 fn print_item(cx: &LateContext<'_>, item: &hir::Item<'_>) {
-    let did = cx.tcx.hir().local_def_id(item.hir_id);
+    let did = item.def_id;
     println!("item `{}`", item.ident.name);
     match item.vis.node {
         hir::VisibilityKind::Public => println!("public"),
@@ -383,8 +383,7 @@ fn print_item(cx: &LateContext<'_>, item: &hir::Item<'_>) {
     }
     match item.kind {
         hir::ItemKind::ExternCrate(ref _renamed_from) => {
-            let def_id = cx.tcx.hir().local_def_id(item.hir_id);
-            if let Some(crate_id) = cx.tcx.extern_mod_stmt_cnum(def_id) {
+            if let Some(crate_id) = cx.tcx.extern_mod_stmt_cnum(did) {
                 let source = cx.tcx.used_crate_source(crate_id);
                 if let Some(ref src) = source.dylib {
                     println!("extern crate dylib source: {:?}", src.0);
diff --git a/src/tools/clippy/clippy_lints/src/wildcard_imports.rs b/src/tools/clippy/clippy_lints/src/wildcard_imports.rs
index 10005a7fc81..094b1a42346 100644
--- a/src/tools/clippy/clippy_lints/src/wildcard_imports.rs
+++ b/src/tools/clippy/clippy_lints/src/wildcard_imports.rs
@@ -113,7 +113,7 @@ impl LateLintPass<'_> for WildcardImports {
         if_chain! {
             if let ItemKind::Use(use_path, UseKind::Glob) = &item.kind;
             if self.warn_on_all || !self.check_exceptions(item, use_path.segments);
-            let used_imports = cx.tcx.names_imported_by_glob_use(item.hir_id.owner);
+            let used_imports = cx.tcx.names_imported_by_glob_use(item.def_id);
             if !used_imports.is_empty(); // Already handled by `unused_imports`
             then {
                 let mut applicability = Applicability::MachineApplicable;