Separate out a `hir::Impl` struct

This makes it possible to pass the `Impl` directly to functions, instead
of having to pass each of the many fields one at a time. It also
simplifies matches in many cases.

28 files changed, 86 insertions, 97 deletions

diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 4c46771fd71..0e61a5a6118 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -358,18 +358,16 @@ crate fn build_impl(
     let impl_item = match did.as_local() {
         Some(did) => {
             let hir_id = tcx.hir().local_def_id_to_hir_id(did);
-            match tcx.hir().expect_item(hir_id).kind {
-                hir::ItemKind::Impl { self_ty, ref generics, ref items, .. } => {
-                    Some((self_ty, generics, items))
-                }
+            match &tcx.hir().expect_item(hir_id).kind {
+                hir::ItemKind::Impl(impl_) => Some(impl_),
                 _ => panic!("`DefID` passed to `build_impl` is not an `impl"),
             }
         }
         None => None,
     };
 
-    let for_ = match impl_item {
-        Some((self_ty, _, _)) => self_ty.clean(cx),
+    let for_ = match &impl_item {
+        Some(impl_) => impl_.self_ty.clean(cx),
         None => tcx.type_of(did).clean(cx),
     };
 
@@ -391,9 +389,13 @@ crate fn build_impl(
 
     let predicates = tcx.explicit_predicates_of(did);
     let (trait_items, generics) = match impl_item {
-        Some((_, generics, items)) => (
-            items.iter().map(|item| tcx.hir().impl_item(item.id).clean(cx)).collect::<Vec<_>>(),
-            generics.clean(cx),
+        Some(impl_) => (
+            impl_
+                .items
+                .iter()
+                .map(|item| tcx.hir().impl_item(item.id).clean(cx))
+                .collect::<Vec<_>>(),
+            impl_.generics.clean(cx),
         ),
         None => (
             tcx.associated_items(did)
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 14564e7f64a..39c29d0fc7f 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2027,7 +2027,7 @@ impl Clean<Vec<Item>> for (&hir::Item<'_>, Option<Symbol>) {
                     fields: variant_data.fields().clean(cx),
                     fields_stripped: false,
                 }),
-                ItemKind::Impl { .. } => return clean_impl(item, 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)
@@ -2081,17 +2081,12 @@ impl Clean<bool> for ty::ImplPolarity {
     }
 }
 
-fn clean_impl(impl_: &hir::Item<'_>, cx: &DocContext<'_>) -> Vec<Item> {
+fn clean_impl(impl_: &hir::Impl<'_>, hir_id: hir::HirId, cx: &DocContext<'_>) -> Vec<Item> {
     let mut ret = Vec::new();
-    let (trait_, items, for_, unsafety, generics) = match &impl_.kind {
-        hir::ItemKind::Impl { of_trait, items, self_ty, unsafety, generics, .. } => {
-            (of_trait, items, self_ty, *unsafety, generics)
-        }
-        _ => unreachable!(),
-    };
-    let trait_ = trait_.clean(cx);
-    let items = items.iter().map(|ii| cx.tcx.hir().impl_item(ii.id).clean(cx)).collect::<Vec<_>>();
-    let def_id = cx.tcx.hir().local_def_id(impl_.hir_id);
+    let trait_ = impl_.of_trait.clean(cx);
+    let items =
+        impl_.items.iter().map(|ii| cx.tcx.hir().impl_item(ii.id).clean(cx)).collect::<Vec<_>>();
+    let def_id = cx.tcx.hir().local_def_id(hir_id);
 
     // If this impl block is an implementation of the Deref trait, then we
     // need to try inlining the target's inherent impl blocks as well.
@@ -2104,15 +2099,15 @@ fn clean_impl(impl_: &hir::Item<'_>, cx: &DocContext<'_>) -> Vec<Item> {
         .map(|did| cx.tcx.provided_trait_methods(did).map(|meth| meth.ident.name).collect())
         .unwrap_or_default();
 
-    let for_ = for_.clean(cx);
+    let for_ = impl_.self_ty.clean(cx);
     let type_alias = for_.def_id().and_then(|did| match cx.tcx.def_kind(did) {
         DefKind::TyAlias => Some(cx.tcx.type_of(did).clean(cx)),
         _ => None,
     });
     let make_item = |trait_: Option<Type>, for_: Type, items: Vec<Item>| {
         let kind = ImplItem(Impl {
-            unsafety,
-            generics: generics.clean(cx),
+            unsafety: impl_.unsafety,
+            generics: impl_.generics.clean(cx),
             provided_trait_methods: provided.clone(),
             trait_,
             for_,
@@ -2121,7 +2116,7 @@ fn clean_impl(impl_: &hir::Item<'_>, cx: &DocContext<'_>) -> Vec<Item> {
             synthetic: false,
             blanket_impl: None,
         });
-        Item::from_hir_id_and_parts(impl_.hir_id, None, kind, cx)
+        Item::from_hir_id_and_parts(hir_id, None, kind, cx)
     };
     if let Some(type_alias) = type_alias {
         ret.push(make_item(trait_.clone(), type_alias, items.clone()));
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 09627be9701..cf51162cfb5 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -1026,8 +1026,8 @@ impl<'a, 'hir, 'tcx> intravisit::Visitor<'hir> for HirCollector<'a, 'hir, 'tcx>
     }
 
     fn visit_item(&mut self, item: &'hir hir::Item<'_>) {
-        let name = if let hir::ItemKind::Impl { ref self_ty, .. } = item.kind {
-            rustc_hir_pretty::id_to_string(&self.map, self_ty.hir_id)
+        let name = if let hir::ItemKind::Impl(impl_) = &item.kind {
+            rustc_hir_pretty::id_to_string(&self.map, impl_.self_ty.hir_id)
         } else {
             item.ident.to_string()
         };
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 1fedd26a1ef..f701352c486 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -352,10 +352,10 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                     om.items.push((item, renamed));
                 }
             }
-            hir::ItemKind::Impl { ref of_trait, .. } => {
+            hir::ItemKind::Impl(ref impl_) => {
                 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
                 // them up regardless of where they're located.
-                if !self.inlining && of_trait.is_none() {
+                if !self.inlining && impl_.of_trait.is_none() {
                     om.items.push((item, None));
                 }
             }
diff --git a/src/tools/clippy/clippy_lints/src/copy_iterator.rs b/src/tools/clippy/clippy_lints/src/copy_iterator.rs
index 34940245322..a7aa2cb35c1 100644
--- a/src/tools/clippy/clippy_lints/src/copy_iterator.rs
+++ b/src/tools/clippy/clippy_lints/src/copy_iterator.rs
@@ -1,5 +1,5 @@
 use crate::utils::{is_copy, match_path, paths, span_lint_and_note};
-use rustc_hir::{Item, ItemKind};
+use rustc_hir::{Item, ItemKind, Impl};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
@@ -33,10 +33,10 @@ declare_lint_pass!(CopyIterator => [COPY_ITERATOR]);
 
 impl<'tcx> LateLintPass<'tcx> for CopyIterator {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Impl {
+        if let ItemKind::Impl(Impl {
             of_trait: Some(ref trait_ref),
             ..
-        } = item.kind
+        }) = item.kind
         {
             let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
 
diff --git a/src/tools/clippy/clippy_lints/src/derive.rs b/src/tools/clippy/clippy_lints/src/derive.rs
index c75efc6e99f..b55f59f021d 100644
--- a/src/tools/clippy/clippy_lints/src/derive.rs
+++ b/src/tools/clippy/clippy_lints/src/derive.rs
@@ -7,7 +7,7 @@ use if_chain::if_chain;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, NestedVisitorMap, Visitor};
 use rustc_hir::{
-    BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Item, ItemKind, TraitRef, UnsafeSource, Unsafety,
+    BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Item, ItemKind, Impl, TraitRef, UnsafeSource, Unsafety,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::map::Map;
@@ -164,10 +164,10 @@ declare_lint_pass!(Derive => [
 
 impl<'tcx> LateLintPass<'tcx> for Derive {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Impl {
+        if let ItemKind::Impl(Impl {
             of_trait: Some(ref trait_ref),
             ..
-        } = item.kind
+        }) = item.kind
         {
             let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
             let is_automatically_derived = is_automatically_derived(&*item.attrs);
diff --git a/src/tools/clippy/clippy_lints/src/doc.rs b/src/tools/clippy/clippy_lints/src/doc.rs
index aba65532795..f518da55cd7 100644
--- a/src/tools/clippy/clippy_lints/src/doc.rs
+++ b/src/tools/clippy/clippy_lints/src/doc.rs
@@ -182,11 +182,8 @@ impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
                     lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
                 }
             },
-            hir::ItemKind::Impl {
-                of_trait: ref trait_ref,
-                ..
-            } => {
-                self.in_trait_impl = trait_ref.is_some();
+            hir::ItemKind::Impl(ref impl_) => {
+                self.in_trait_impl = impl_.of_trait.is_some();
             },
             _ => {},
         }
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
index d2dcb3e5c46..55087697812 100644
--- a/src/tools/clippy/clippy_lints/src/escape.rs
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -1,5 +1,5 @@
 use rustc_hir::intravisit;
-use rustc_hir::{self, Body, FnDecl, HirId, HirIdSet, ItemKind, Node};
+use rustc_hir::{self, Body, FnDecl, HirId, HirIdSet, ItemKind, Impl, Node};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, Ty};
@@ -77,7 +77,7 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
         let parent_node = cx.tcx.hir().find(parent_id);
 
         if let Some(Node::Item(item)) = parent_node {
-            if let ItemKind::Impl { of_trait: Some(_), .. } = item.kind {
+            if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = item.kind {
                 return;
             }
         }
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 509a4a4e15f..9f389c8d2f9 100644
--- a/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
+++ b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
@@ -57,11 +57,11 @@ impl<'tcx> LateLintPass<'tcx> for FallibleImplFrom {
         // 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{ items: impl_items, .. } = item.kind;
+            if let hir::ItemKind::Impl(impl_) = &item.kind;
             if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_def_id);
             if match_def_path(cx, impl_trait_ref.def_id, &FROM_TRAIT);
             then {
-                lint_impl_body(cx, item.span, impl_items);
+                lint_impl_body(cx, item.span, impl_.items);
             }
         }
     }
diff --git a/src/tools/clippy/clippy_lints/src/inherent_impl.rs b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
index 4e6bb604785..e287aecb044 100644
--- a/src/tools/clippy/clippy_lints/src/inherent_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
@@ -2,7 +2,7 @@
 
 use crate::utils::{in_macro, span_lint_and_then};
 use rustc_data_structures::fx::FxHashMap;
-use rustc_hir::{def_id, Crate, Item, ItemKind};
+use rustc_hir::{def_id, Crate, Item, ItemKind, Impl};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::Span;
@@ -49,11 +49,11 @@ impl_lint_pass!(MultipleInherentImpl => [MULTIPLE_INHERENT_IMPL]);
 
 impl<'tcx> LateLintPass<'tcx> for MultipleInherentImpl {
     fn check_item(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Impl {
+        if let ItemKind::Impl(Impl {
             ref generics,
             of_trait: None,
             ..
-        } = item.kind
+        }) = item.kind
         {
             // Remember for each inherent implementation encountered its span and generics
             // but filter out implementations that have generic params (type or lifetime)
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index 6fe53351090..5474b30bdec 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -3,7 +3,7 @@ use rustc_ast::ast::LitKind;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
-use rustc_hir::{AssocItemKind, BinOpKind, Expr, ExprKind, ImplItemRef, Item, ItemKind, TraitItemRef};
+use rustc_hir::{AssocItemKind, BinOpKind, Expr, ExprKind, ImplItemRef, Item, ItemKind, Impl, TraitItemRef};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -115,11 +115,11 @@ impl<'tcx> LateLintPass<'tcx> for LenZero {
 
         match item.kind {
             ItemKind::Trait(_, _, _, _, ref trait_items) => check_trait_items(cx, item, trait_items),
-            ItemKind::Impl {
+            ItemKind::Impl(Impl {
                 of_trait: None,
                 items: ref impl_items,
                 ..
-            } => check_impl_items(cx, item, impl_items),
+            }) => check_impl_items(cx, item, impl_items),
             _ => (),
         }
     }
diff --git a/src/tools/clippy/clippy_lints/src/methods/mod.rs b/src/tools/clippy/clippy_lints/src/methods/mod.rs
index e99fe1b97ff..2658c365e13 100644
--- a/src/tools/clippy/clippy_lints/src/methods/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/methods/mod.rs
@@ -1626,7 +1626,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
         let self_ty = cx.tcx.type_of(def_id);
 
         // if this impl block implements a trait, lint in trait definition instead
-        if let hir::ItemKind::Impl { of_trait: Some(_), .. } = item.kind {
+        if let hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = item.kind {
             return;
         }
 
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 5043b7b1fc3..a435f86bfd8 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -8,7 +8,7 @@ use rustc_ast::ast::Attribute;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, ItemKind, Node, PatKind, QPath, TyKind};
+use rustc_hir::{BindingAnnotation, Body, FnDecl, GenericArg, HirId, ItemKind, Impl, Node, PatKind, QPath, TyKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, TypeFoldable};
@@ -92,7 +92,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
         if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
             if matches!(
                 item.kind,
-                ItemKind::Impl { of_trait: Some(_), .. } | ItemKind::Trait(..)
+                ItemKind::Impl(Impl { of_trait: Some(_), .. }) | ItemKind::Trait(..)
             ) {
                 return;
             }
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 68fdd0eb269..bd3dac663fe 100644
--- a/src/tools/clippy/clippy_lints/src/new_without_default.rs
+++ b/src/tools/clippy/clippy_lints/src/new_without_default.rs
@@ -60,9 +60,9 @@ impl_lint_pass!(NewWithoutDefault => [NEW_WITHOUT_DEFAULT]);
 impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
     #[allow(clippy::too_many_lines)]
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
-        if let hir::ItemKind::Impl {
+        if let hir::ItemKind::Impl(hir::Impl {
             of_trait: None, items, ..
-        } = item.kind
+        }) = item.kind
         {
             for assoc_item in items {
                 if let hir::AssocItemKind::Fn { has_self: false } = assoc_item.kind {
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 6b0d198edcf..3a9aa6ced03 100644
--- a/src/tools/clippy/clippy_lints/src/non_copy_const.rs
+++ b/src/tools/clippy/clippy_lints/src/non_copy_const.rs
@@ -7,7 +7,7 @@ use std::ptr;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{
-    BodyId, Expr, ExprKind, HirId, ImplItem, ImplItemKind, Item, ItemKind, Node, TraitItem, TraitItemKind, UnOp,
+    BodyId, Expr, ExprKind, HirId, Impl, ImplItem, ImplItemKind, Item, ItemKind, Node, TraitItem, TraitItemKind, UnOp,
 };
 use rustc_infer::traits::specialization_graph;
 use rustc_lint::{LateContext, LateLintPass, Lint};
@@ -275,10 +275,10 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
             let item = cx.tcx.hir().expect_item(item_hir_id);
 
             match &item.kind {
-                ItemKind::Impl {
+                ItemKind::Impl(Impl {
                     of_trait: Some(of_trait_ref),
                     ..
-                } => {
+                }) => {
                     if_chain! {
                         // Lint a trait impl item only when the definition is a generic type,
                         // assuming a assoc const is not meant to be a interior mutable type.
@@ -317,7 +317,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
                         }
                     }
                 },
-                ItemKind::Impl { of_trait: None, .. } => {
+                ItemKind::Impl(Impl { of_trait: None, .. }) => {
                     let ty = hir_ty_to_ty(cx.tcx, hir_ty);
                     // Normalize assoc types originated from generic params.
                     let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty);
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 ceecc8dbc06..04b6e5d5847 100644
--- a/src/tools/clippy/clippy_lints/src/partialeq_ne_impl.rs
+++ b/src/tools/clippy/clippy_lints/src/partialeq_ne_impl.rs
@@ -1,6 +1,6 @@
 use crate::utils::{is_automatically_derived, span_lint_hir};
 use if_chain::if_chain;
-use rustc_hir::{Item, ItemKind};
+use rustc_hir::{Item, ItemKind, Impl};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
@@ -34,7 +34,7 @@ declare_lint_pass!(PartialEqNeImpl => [PARTIALEQ_NE_IMPL]);
 impl<'tcx> LateLintPass<'tcx> for PartialEqNeImpl {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
         if_chain! {
-            if let ItemKind::Impl{ of_trait: Some(ref trait_ref), items: impl_items, .. } = item.kind;
+            if let ItemKind::Impl(Impl { of_trait: Some(ref trait_ref), items: impl_items, .. }) = item.kind;
             if !is_automatically_derived(&*item.attrs);
             if let Some(eq_trait) = cx.tcx.lang_items().eq_trait();
             if trait_ref.path.res.def_id() == eq_trait;
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 6a17d654ac9..7814065e31a 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
@@ -6,7 +6,7 @@ use rustc_ast::attr;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{BindingAnnotation, Body, FnDecl, HirId, ItemKind, MutTy, Mutability, Node, PatKind};
+use rustc_hir::{BindingAnnotation, Body, FnDecl, HirId, ItemKind, MutTy, Mutability, Node, PatKind, Impl};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
@@ -246,7 +246,7 @@ impl<'tcx> LateLintPass<'tcx> for PassByRefOrValue {
         if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
             if matches!(
                 item.kind,
-                ItemKind::Impl { of_trait: Some(_), .. } | ItemKind::Trait(..)
+                ItemKind::Impl(Impl { of_trait: Some(_), .. }) | ItemKind::Trait(..)
             ) {
                 return;
             }
diff --git a/src/tools/clippy/clippy_lints/src/ptr.rs b/src/tools/clippy/clippy_lints/src/ptr.rs
index c494a713631..b832add009f 100644
--- a/src/tools/clippy/clippy_lints/src/ptr.rs
+++ b/src/tools/clippy/clippy_lints/src/ptr.rs
@@ -8,7 +8,7 @@ use crate::utils::{
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::{
-    BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, HirId, ImplItem, ImplItemKind, Item, ItemKind,
+    BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, HirId, ImplItem, ImplItemKind, Item, ItemKind, Impl,
     Lifetime, MutTy, Mutability, Node, PathSegment, QPath, TraitFn, TraitItem, TraitItemKind, Ty, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
@@ -132,7 +132,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
         if let ImplItemKind::Fn(ref sig, body_id) = item.kind {
             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 { of_trait: Some(_), .. } = it.kind {
+                if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = it.kind {
                     return; // ignore trait impls
                 }
             }
diff --git a/src/tools/clippy/clippy_lints/src/serde_api.rs b/src/tools/clippy/clippy_lints/src/serde_api.rs
index 339a7cf3bf5..ca4fd9f3559 100644
--- a/src/tools/clippy/clippy_lints/src/serde_api.rs
+++ b/src/tools/clippy/clippy_lints/src/serde_api.rs
@@ -1,5 +1,5 @@
 use crate::utils::{get_trait_def_id, paths, span_lint};
-use rustc_hir::{Item, ItemKind};
+use rustc_hir::{Item, ItemKind, Impl};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
@@ -22,11 +22,11 @@ declare_lint_pass!(SerdeAPI => [SERDE_API_MISUSE]);
 
 impl<'tcx> LateLintPass<'tcx> for SerdeAPI {
     fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
-        if let ItemKind::Impl {
+        if let ItemKind::Impl(Impl {
             of_trait: Some(ref trait_ref),
             items,
             ..
-        } = item.kind
+        }) = item.kind
         {
             let did = trait_ref.path.res.def_id();
             if let Some(visit_did) = get_trait_def_id(cx, &paths::SERDE_DE_VISITOR) {
diff --git a/src/tools/clippy/clippy_lints/src/to_string_in_display.rs b/src/tools/clippy/clippy_lints/src/to_string_in_display.rs
index 006d7a3a12d..675eaf4277a 100644
--- a/src/tools/clippy/clippy_lints/src/to_string_in_display.rs
+++ b/src/tools/clippy/clippy_lints/src/to_string_in_display.rs
@@ -1,7 +1,7 @@
 use crate::utils::{match_def_path, match_trait_method, paths, qpath_res, span_lint};
 use if_chain::if_chain;
 use rustc_hir::def::Res;
-use rustc_hir::{Expr, ExprKind, HirId, ImplItem, ImplItemKind, Item, ItemKind};
+use rustc_hir::{Expr, ExprKind, HirId, ImplItem, ImplItemKind, Item, ItemKind, Impl};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 
@@ -111,7 +111,7 @@ impl LateLintPass<'_> for ToStringInDisplay {
 
 fn is_display_impl(cx: &LateContext<'_>, item: &Item<'_>) -> bool {
     if_chain! {
-        if let ItemKind::Impl { of_trait: Some(trait_ref), .. } = &item.kind;
+        if let ItemKind::Impl(Impl { of_trait: Some(trait_ref), .. }) = &item.kind;
         if let Some(did) = trait_ref.trait_def_id();
         then {
             match_def_path(cx, did, &paths::DISPLAY_TRAIT)
diff --git a/src/tools/clippy/clippy_lints/src/types.rs b/src/tools/clippy/clippy_lints/src/types.rs
index fd74783335d..2696c5e781a 100644
--- a/src/tools/clippy/clippy_lints/src/types.rs
+++ b/src/tools/clippy/clippy_lints/src/types.rs
@@ -258,7 +258,7 @@ impl<'tcx> LateLintPass<'tcx> for Types {
     fn check_fn(&mut self, cx: &LateContext<'_>, _: FnKind<'_>, decl: &FnDecl<'_>, _: &Body<'_>, _: Span, id: HirId) {
         // Skip trait implementations; see issue #605.
         if let Some(hir::Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_item(id)) {
-            if let ItemKind::Impl { of_trait: Some(_), .. } = item.kind {
+            if let ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = item.kind {
                 return;
             }
         }
@@ -2558,21 +2558,16 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitHasher {
         }
 
         match item.kind {
-            ItemKind::Impl {
-                ref generics,
-                self_ty: ref ty,
-                ref items,
-                ..
-            } => {
+            ItemKind::Impl(ref impl_) => {
                 let mut vis = ImplicitHasherTypeVisitor::new(cx);
-                vis.visit_ty(ty);
+                vis.visit_ty(impl_.self_ty);
 
                 for target in &vis.found {
                     if differing_macro_contexts(item.span, target.span()) {
                         return;
                     }
 
-                    let generics_suggestion_span = generics.span.substitute_dummy({
+                    let generics_suggestion_span = impl_.generics.span.substitute_dummy({
                         let pos = snippet_opt(cx, item.span.until(target.span()))
                             .and_then(|snip| Some(item.span.lo() + BytePos(snip.find("impl")? as u32 + 4)));
                         if let Some(pos) = pos {
@@ -2583,7 +2578,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitHasher {
                     });
 
                     let mut ctr_vis = ImplicitHasherConstructorVisitor::new(cx, target);
-                    for item in items.iter().map(|item| cx.tcx.hir().impl_item(item.id)) {
+                    for item in impl_.items.iter().map(|item| cx.tcx.hir().impl_item(item.id)) {
                         ctr_vis.visit_impl_item(item);
                     }
 
@@ -2596,7 +2591,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitHasher {
                             target.type_name()
                         ),
                         move |diag| {
-                            suggestion(cx, diag, generics.span, generics_suggestion_span, target, ctr_vis);
+                            suggestion(cx, diag, impl_.generics.span, generics_suggestion_span, target, ctr_vis);
                         },
                     );
                 }
diff --git a/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs b/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs
index 5b9a80f92db..07cd752184b 100644
--- a/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs
+++ b/src/tools/clippy/clippy_lints/src/unnecessary_wraps.rs
@@ -5,7 +5,7 @@ use crate::utils::{
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, ExprKind, FnDecl, HirId, ItemKind, Node};
+use rustc_hir::{Body, ExprKind, FnDecl, HirId, ItemKind, Impl, Node};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -77,7 +77,7 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWraps {
         if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
             if matches!(
                 item.kind,
-                ItemKind::Impl { of_trait: Some(_), .. } | ItemKind::Trait(..)
+                ItemKind::Impl(Impl { of_trait: Some(_), .. }) | ItemKind::Trait(..)
             ) {
                 return;
             }
diff --git a/src/tools/clippy/clippy_lints/src/unused_self.rs b/src/tools/clippy/clippy_lints/src/unused_self.rs
index da7517125c1..a6171794311 100644
--- a/src/tools/clippy/clippy_lints/src/unused_self.rs
+++ b/src/tools/clippy/clippy_lints/src/unused_self.rs
@@ -1,7 +1,7 @@
 use if_chain::if_chain;
 use rustc_hir::def::Res;
 use rustc_hir::intravisit::{walk_path, NestedVisitorMap, Visitor};
-use rustc_hir::{HirId, ImplItem, ImplItemKind, ItemKind, Path};
+use rustc_hir::{HirId, ImplItem, ImplItemKind, ItemKind, Impl, Path};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::map::Map;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -49,7 +49,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedSelf {
         let def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
         let assoc_item = cx.tcx.associated_item(def_id);
         if_chain! {
-            if let ItemKind::Impl { of_trait: None, .. } = parent_item.kind;
+            if let ItemKind::Impl(Impl { of_trait: None, .. }) = parent_item.kind;
             if assoc_item.fn_has_self_parameter;
             if let ImplItemKind::Fn(.., body_id) = &impl_item.kind;
             let body = cx.tcx.hir().body(*body_id);
diff --git a/src/tools/clippy/clippy_lints/src/use_self.rs b/src/tools/clippy/clippy_lints/src/use_self.rs
index 3b23f885e08..b82ea66190f 100644
--- a/src/tools/clippy/clippy_lints/src/use_self.rs
+++ b/src/tools/clippy/clippy_lints/src/use_self.rs
@@ -181,8 +181,8 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
             return;
         }
         if_chain! {
-            if let ItemKind::Impl{ self_ty: ref item_type, items: refs, .. } = item.kind;
-            if let TyKind::Path(QPath::Resolved(_, ref item_path)) = item_type.kind;
+            if let ItemKind::Impl(impl_) = &item.kind;
+            if let TyKind::Path(QPath::Resolved(_, ref item_path)) = impl_.self_ty.kind;
             then {
                 let parameters = &item_path.segments.last().expect(SEGMENTS_MSG).args;
                 let should_check = parameters.as_ref().map_or(
@@ -200,7 +200,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                     let impl_trait_ref = cx.tcx.impl_trait_ref(impl_def_id);
 
                     if let Some(impl_trait_ref) = impl_trait_ref {
-                        for impl_item_ref in refs {
+                        for impl_item_ref in impl_.items {
                             let impl_item = cx.tcx.hir().impl_item(impl_item_ref.id);
                             if let ImplItemKind::Fn(FnSig{ decl: impl_decl, .. }, impl_body_id)
                                     = &impl_item.kind {
@@ -213,7 +213,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                             }
                         }
                     } else {
-                        for impl_item_ref in refs {
+                        for impl_item_ref in impl_.items {
                             let impl_item = cx.tcx.hir().impl_item(impl_item_ref.id);
                             visitor.visit_impl_item(impl_item);
                         }
diff --git a/src/tools/clippy/clippy_lints/src/utils/inspector.rs b/src/tools/clippy/clippy_lints/src/utils/inspector.rs
index 5d946e4bd49..a02c0a3f44d 100644
--- a/src/tools/clippy/clippy_lints/src/utils/inspector.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/inspector.rs
@@ -423,13 +423,13 @@ fn print_item(cx: &LateContext<'_>, item: &hir::Item<'_>) {
         hir::ItemKind::TraitAlias(..) => {
             println!("trait alias");
         },
-        hir::ItemKind::Impl {
+        hir::ItemKind::Impl(hir::Impl {
             of_trait: Some(ref _trait_ref),
             ..
-        } => {
+        }) => {
             println!("trait impl");
         },
-        hir::ItemKind::Impl { of_trait: None, .. } => {
+        hir::ItemKind::Impl(hir::Impl { of_trait: None, .. }) => {
             println!("impl");
         },
     }
diff --git a/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs b/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs
index 9ba39f73ee8..407f06f4894 100644
--- a/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/internal_lints.rs
@@ -352,11 +352,11 @@ impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass {
         } else if is_expn_of(item.span, "impl_lint_pass").is_some()
             || is_expn_of(item.span, "declare_lint_pass").is_some()
         {
-            if let hir::ItemKind::Impl {
+            if let hir::ItemKind::Impl(hir::Impl {
                 of_trait: None,
                 items: ref impl_item_refs,
                 ..
-            } = item.kind
+            }) = item.kind
             {
                 let mut collector = LintCollector {
                     output: &mut self.registered_lints,
diff --git a/src/tools/clippy/clippy_lints/src/utils/mod.rs b/src/tools/clippy/clippy_lints/src/utils/mod.rs
index 1c68e837c4a..87f99019d72 100644
--- a/src/tools/clippy/clippy_lints/src/utils/mod.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/mod.rs
@@ -439,8 +439,8 @@ pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Optio
     if_chain! {
         if parent_impl != hir::CRATE_HIR_ID;
         if let hir::Node::Item(item) = cx.tcx.hir().get(parent_impl);
-        if let hir::ItemKind::Impl{ of_trait: trait_ref, .. } = &item.kind;
-        then { return trait_ref.as_ref(); }
+        if let hir::ItemKind::Impl(impl_) = &item.kind;
+        then { return impl_.of_trait.as_ref(); }
     }
     None
 }
@@ -1530,7 +1530,7 @@ pub fn is_no_std_crate(krate: &Crate<'_>) -> bool {
 /// ```
 pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool {
     if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
-        matches!(item.kind, ItemKind::Impl { of_trait: Some(_), .. })
+        matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }))
     } else {
         false
     }
diff --git a/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs b/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs
index 1d5fa8d06a9..9761e822a7a 100644
--- a/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs
+++ b/src/tools/clippy/clippy_lints/src/zero_sized_map_values.rs
@@ -62,7 +62,7 @@ impl LateLintPass<'_> for ZeroSizedMapValues {
 fn in_trait_impl(cx: &LateContext<'_>, hir_id: HirId) -> bool {
     let parent_id = cx.tcx.hir().get_parent_item(hir_id);
     if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_item(parent_id)) {
-        if let ItemKind::Impl { of_trait: Some(_), .. } = item.kind {
+        if let ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) = item.kind {
             return true;
         }
     }