Convert more impls of DocFolder to DocVisitor

I think these are the last of the impls that can be easily converted to visitors.

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -32,10 +32,10 @@ use std::ops::Range;
 
 use crate::clean::{self, utils::find_nearest_parent_module, Crate, Item, ItemLink, PrimitiveType};
 use crate::core::DocContext;
-use crate::fold::DocFolder;
 use crate::html::markdown::{markdown_links, MarkdownLink};
 use crate::lint::{BROKEN_INTRA_DOC_LINKS, PRIVATE_INTRA_DOC_LINKS};
 use crate::passes::Pass;
+use crate::visit::DocVisitor;
 
 mod early;
 crate use early::load_intra_link_crates;
@@ -47,13 +47,14 @@ crate const COLLECT_INTRA_DOC_LINKS: Pass = Pass {
 };
 
 fn collect_intra_doc_links(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
-    LinkCollector {
+    let mut collector = LinkCollector {
         cx,
         mod_ids: Vec::new(),
         kind_side_channel: Cell::new(None),
         visited_links: FxHashMap::default(),
-    }
-    .fold_crate(krate)
+    };
+    collector.visit_crate(&krate);
+    krate
 }
 
 /// Top-level errors emitted by this pass.
@@ -816,8 +817,8 @@ fn is_derive_trait_collision<T>(ns: &PerNS<Result<(Res, T), ResolutionFailure<'_
     )
 }
 
-impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
-    fn fold_item(&mut self, item: Item) -> Option<Item> {
+impl<'a, 'tcx> DocVisitor for LinkCollector<'a, 'tcx> {
+    fn visit_item(&mut self, item: &Item) {
         use rustc_middle::ty::DefIdTree;
 
         let parent_node =
@@ -911,17 +912,16 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
             }
         }
 
-        Some(if item.is_mod() {
+        if item.is_mod() {
             if !inner_docs {
                 self.mod_ids.push(item.def_id.expect_def_id());
             }
 
-            let ret = self.fold_item_recur(item);
+            self.visit_item_recur(item);
             self.mod_ids.pop();
-            ret
         } else {
-            self.fold_item_recur(item)
-        })
+            self.visit_item_recur(item)
+        }
     }
 }
 

src/librustdoc/passes/collect_trait_impls.rs

@@ -1,7 +1,6 @@
 use super::Pass;
-use crate::clean::*;
 use crate::core::DocContext;
-use crate::fold::DocFolder;
+use crate::{clean::*, visit::DocVisitor};
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::DefId;
@@ -14,17 +13,18 @@ crate const COLLECT_TRAIT_IMPLS: Pass = Pass {
     description: "retrieves trait impls for items in the crate",
 };
 
-crate fn collect_trait_impls(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
-    let (mut krate, synth_impls) = cx.sess().time("collect_synthetic_impls", || {
+crate fn collect_trait_impls(mut krate: Crate, cx: &mut DocContext<'_>) -> Crate {
+    let synth_impls = cx.sess().time("collect_synthetic_impls", || {
         let mut synth = SyntheticImplCollector { cx, impls: Vec::new() };
-        (synth.fold_crate(krate), synth.impls)
+        synth.visit_crate(&krate);
+        synth.impls
     });
 
     let prims: FxHashSet<PrimitiveType> = krate.primitives.iter().map(|p| p.1).collect();
 
     let crate_items = {
         let mut coll = ItemCollector::new();
-        krate = cx.sess().time("collect_items_for_trait_impls", || coll.fold_crate(krate));
+        cx.sess().time("collect_items_for_trait_impls", || coll.visit_crate(&krate));
         coll.items
     };
 
@@ -152,14 +152,13 @@ crate fn collect_trait_impls(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
         }
     }
 
-    let items = if let ModuleItem(Module { ref mut items, .. }) = *krate.module.kind {
-        items
+    if let ModuleItem(Module { items, .. }) = &mut *krate.module.kind {
+        items.extend(synth_impls);
+        items.extend(new_items);
     } else {
         panic!("collect-trait-impls can't run");
     };
 
-    items.extend(synth_impls);
-    items.extend(new_items);
     krate
 }
 
@@ -168,8 +167,8 @@ struct SyntheticImplCollector<'a, 'tcx> {
     impls: Vec<Item>,
 }
 
-impl<'a, 'tcx> DocFolder for SyntheticImplCollector<'a, 'tcx> {
-    fn fold_item(&mut self, i: Item) -> Option<Item> {
+impl<'a, 'tcx> DocVisitor for SyntheticImplCollector<'a, 'tcx> {
+    fn visit_item(&mut self, i: &Item) {
         if i.is_struct() || i.is_enum() || i.is_union() {
             // FIXME(eddyb) is this `doc(hidden)` check needed?
             if !self
@@ -184,7 +183,7 @@ impl<'a, 'tcx> DocFolder for SyntheticImplCollector<'a, 'tcx> {
             }
         }
 
-        Some(self.fold_item_recur(i))
+        self.visit_item_recur(i)
     }
 }
 
@@ -199,11 +198,11 @@ impl ItemCollector {
     }
 }
 
-impl DocFolder for ItemCollector {
-    fn fold_item(&mut self, i: Item) -> Option<Item> {
+impl DocVisitor for ItemCollector {
+    fn visit_item(&mut self, i: &Item) {
         self.items.insert(i.def_id);
 
-        Some(self.fold_item_recur(i))
+        self.visit_item_recur(i)
     }
 }