Move Item visiting responsibility to WalkItemKind

Author: maxcabrajac

compiler/rustc_ast/src/visitors.rs

@@ -1162,7 +1162,6 @@ pub mod visit {
 
     pub trait WalkItemKind: Sized {
         fn walk<'a, V: Visitor<'a>>(
-            &'a self,
             item: &'a Item<Self>,
             visitor: &mut V,
         ) -> V::Result;
@@ -1172,12 +1171,14 @@ pub mod visit {
 
     impl WalkItemKind for ItemKind {
         fn walk<'a, V: Visitor<'a>>(
-            &'a self,
             item: &'a Item<Self>,
             visitor: &mut V,
         ) -> V::Result {
-            let Item { id, span, vis, ident, .. } = item;
-            match self {
+            let Item { id, span, ident, vis, attrs, kind, tokens: _ } = item;
+            walk_list!(visitor, visit_attribute, attrs);
+            try_visit!(visitor.visit_vis(vis));
+            try_visit!(visitor.visit_ident(*ident));
+            match kind {
                 ItemKind::ExternCrate(_rename) => {}
                 ItemKind::Use(use_tree) => try_visit!(visitor.visit_use_tree(use_tree, *id, false)),
                 ItemKind::Static(box StaticItem { ty, safety: _, mutability: _, expr }) => {
@@ -1281,15 +1282,11 @@ pub mod visit {
         }
     }
 
-    pub fn walk_item<'a, V: Visitor<'a>>(
+    pub fn walk_item<'a, V: Visitor<'a>, I: WalkItemKind>(
         visitor: &mut V,
-        item: &'a Item<impl WalkItemKind>,
+        item: &'a Item<I>,
     ) -> V::Result {
-        let &Item { id: _, span: _, ident, ref vis, ref attrs, ref kind, tokens: _ } = item;
-        walk_list!(visitor, visit_attribute, attrs);
-        try_visit!(visitor.visit_vis(vis));
-        try_visit!(visitor.visit_ident(ident));
-        try_visit!(kind.walk(item, visitor));
+        try_visit!(I::walk(item, visitor));
         V::Result::output()
     }
 
@@ -1362,20 +1359,22 @@ pub mod visit {
 
     impl WalkItemKind for ForeignItemKind {
         fn walk<'a, V: Visitor<'a>>(
-            &'a self,
             item: &'a Item<Self>,
             visitor: &mut V,
         ) -> V::Result {
-            let &Item { id, span, ident, ref vis, .. } = item;
-            match self {
+            let Item { id, span, ident, vis, attrs, kind, tokens: _ } = item;
+            walk_list!(visitor, visit_attribute, attrs);
+            try_visit!(visitor.visit_vis(vis));
+            try_visit!(visitor.visit_ident(*ident));
+            match kind {
                 ForeignItemKind::Static(box StaticItem { ty, mutability: _, expr, safety: _ }) => {
                     try_visit!(visitor.visit_ty(ty));
                     visit_opt!(visitor, visit_expr, expr);
                 }
                 ForeignItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => {
                     let kind =
-                        FnKind::Fn(FnCtxt::Foreign, ident, sig, vis, generics, body.as_deref());
-                    try_visit!(visitor.visit_fn(kind, span, id));
+                        FnKind::Fn(FnCtxt::Foreign, *ident, sig, vis, generics, body.as_deref());
+                    try_visit!(visitor.visit_fn(kind, *span, *id));
                 }
                 ForeignItemKind::TyAlias(box TyAlias {
                     generics,

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -7,7 +7,7 @@
 
 use std::cell::Cell;
 
-use rustc_ast::visit::{self, AssocCtxt, Visitor, WalkItemKind};
+use rustc_ast::visit::{self, AssocCtxt, Visitor};
 use rustc_ast::{
     self as ast, AssocItem, AssocItemKind, Block, ForeignItem, ForeignItemKind, Impl, Item,
     ItemKind, MetaItemKind, NodeId, StmtKind,
@@ -1329,7 +1329,7 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                         // This way they can use `macro_rules` defined later.
                         self.visit_vis(&item.vis);
                         self.visit_ident(item.ident);
-                        item.kind.walk(item, self);
+                        visit::walk_item(self, item);
                         visit::walk_list!(self, visit_attribute, &item.attrs);
                     }
                     _ => visit::walk_item(self, item),