Rollup merge of #141279 - nnethercote:lower_to_hir, r=compiler-errors

`lower_to_hir` cleanups

Some minor cleanups I made when reading this code.

r? `@Nadrieril`

Author: matthiaskrgr

compiler/rustc_ast_lowering/src/item.rs

@@ -70,44 +70,32 @@ impl<'a, 'hir> ItemLowerer<'a, 'hir> {
         }
     }
 
-    pub(super) fn lower_node(&mut self, def_id: LocalDefId) -> hir::MaybeOwner<'hir> {
+    pub(super) fn lower_node(&mut self, def_id: LocalDefId) {
         let owner = self.owners.ensure_contains_elem(def_id, || hir::MaybeOwner::Phantom);
         if let hir::MaybeOwner::Phantom = owner {
             let node = self.ast_index[def_id];
             match node {
                 AstOwner::NonOwner => {}
-                AstOwner::Crate(c) => self.lower_crate(c),
-                AstOwner::Item(item) => self.lower_item(item),
-                AstOwner::AssocItem(item, ctxt) => self.lower_assoc_item(item, ctxt),
-                AstOwner::ForeignItem(item) => self.lower_foreign_item(item),
+                AstOwner::Crate(c) => {
+                    debug_assert_eq!(self.resolver.node_id_to_def_id[&CRATE_NODE_ID], CRATE_DEF_ID);
+                    self.with_lctx(CRATE_NODE_ID, |lctx| {
+                        let module = lctx.lower_mod(&c.items, &c.spans);
+                        // FIXME(jdonszelman): is dummy span ever a problem here?
+                        lctx.lower_attrs(hir::CRATE_HIR_ID, &c.attrs, DUMMY_SP);
+                        hir::OwnerNode::Crate(module)
+                    })
+                }
+                AstOwner::Item(item) => {
+                    self.with_lctx(item.id, |lctx| hir::OwnerNode::Item(lctx.lower_item(item)))
+                }
+                AstOwner::AssocItem(item, ctxt) => {
+                    self.with_lctx(item.id, |lctx| lctx.lower_assoc_item(item, ctxt))
+                }
+                AstOwner::ForeignItem(item) => self.with_lctx(item.id, |lctx| {
+                    hir::OwnerNode::ForeignItem(lctx.lower_foreign_item(item))
+                }),
             }
         }
-
-        self.owners[def_id]
-    }
-
-    #[instrument(level = "debug", skip(self, c))]
-    fn lower_crate(&mut self, c: &Crate) {
-        debug_assert_eq!(self.resolver.node_id_to_def_id[&CRATE_NODE_ID], CRATE_DEF_ID);
-        self.with_lctx(CRATE_NODE_ID, |lctx| {
-            let module = lctx.lower_mod(&c.items, &c.spans);
-            // FIXME(jdonszelman): is dummy span ever a problem here?
-            lctx.lower_attrs(hir::CRATE_HIR_ID, &c.attrs, DUMMY_SP);
-            hir::OwnerNode::Crate(module)
-        })
-    }
-
-    #[instrument(level = "debug", skip(self))]
-    fn lower_item(&mut self, item: &Item) {
-        self.with_lctx(item.id, |lctx| hir::OwnerNode::Item(lctx.lower_item(item)))
-    }
-
-    fn lower_assoc_item(&mut self, item: &AssocItem, ctxt: AssocCtxt) {
-        self.with_lctx(item.id, |lctx| lctx.lower_assoc_item(item, ctxt))
-    }
-
-    fn lower_foreign_item(&mut self, item: &ForeignItem) {
-        self.with_lctx(item.id, |lctx| hir::OwnerNode::ForeignItem(lctx.lower_foreign_item(item)))
     }
 }
 

compiler/rustc_ast_lowering/src/lib.rs

@@ -444,14 +444,14 @@ pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> {
         tcx.definitions_untracked().def_index_count(),
     );
 
+    let mut lowerer = item::ItemLowerer {
+        tcx,
+        resolver: &mut resolver,
+        ast_index: &ast_index,
+        owners: &mut owners,
+    };
     for def_id in ast_index.indices() {
-        item::ItemLowerer {
-            tcx,
-            resolver: &mut resolver,
-            ast_index: &ast_index,
-            owners: &mut owners,
-        }
-        .lower_node(def_id);
+        lowerer.lower_node(def_id);
     }
 
     drop(ast_index);