[EXPERIMENT] rustdoc: Cleanup external_traits

src/librustdoc/clean/inline.rs

@@ -674,16 +674,11 @@ crate fn record_extern_trait(cx: &mut DocContext<'_>, did: DefId) {
         return;
     }
 
-    {
-        if cx.external_traits.borrow().contains_key(&did) || cx.active_extern_traits.contains(&did)
-        {
-            return;
-        }
+    if cx.external_traits.contains_key(&did) || cx.active_extern_traits.contains(&did) {
+        return;
     }
 
-    {
-        cx.active_extern_traits.insert(did);
-    }
+    cx.active_extern_traits.insert(did);
 
     debug!("record_extern_trait: {:?}", did);
     let trait_ = build_external_trait(cx, did);
@@ -692,6 +687,6 @@ crate fn record_extern_trait(cx: &mut DocContext<'_>, did: DefId) {
         trait_,
         is_notable: clean::utils::has_doc_flag(cx.tcx.get_attrs(did), sym::notable_trait),
     };
-    cx.external_traits.borrow_mut().insert(did, trait_);
+    cx.external_traits.insert(did, trait_);
     cx.active_extern_traits.remove(&did);
 }

src/librustdoc/clean/types.rs

@@ -1,10 +1,8 @@
-use std::cell::RefCell;
 use std::default::Default;
 use std::hash::{Hash, Hasher};
 use std::iter::FromIterator;
 use std::lazy::SyncOnceCell as OnceCell;
 use std::path::PathBuf;
-use std::rc::Rc;
 use std::sync::Arc;
 use std::{slice, vec};
 
@@ -120,8 +118,6 @@ crate struct Crate {
     crate module: Item,
     crate externs: Vec<ExternalCrate>,
     crate primitives: ThinVec<(DefId, PrimitiveType)>,
-    /// Only here so that they can be filtered through the rustdoc passes.
-    crate external_traits: Rc<RefCell<FxHashMap<DefId, TraitWithExtraInfo>>>,
     crate collapsed: bool,
 }
 

src/librustdoc/clean/utils.rs

@@ -79,15 +79,7 @@ crate fn krate(cx: &mut DocContext<'_>) -> Crate {
         }));
     }
 
-    Crate {
-        name,
-        src,
-        module,
-        externs,
-        primitives,
-        external_traits: cx.external_traits.clone(),
-        collapsed: false,
-    }
+    Crate { name, src, module, externs, primitives, collapsed: false }
 }
 
 fn external_generic_args(

src/librustdoc/core.rs

@@ -49,8 +49,10 @@ crate struct DocContext<'tcx> {
     ///
     /// Most of this logic is copied from rustc_lint::late.
     crate param_env: ParamEnv<'tcx>,
-    /// Later on moved through `clean::Crate` into `cache`
-    crate external_traits: Rc<RefCell<FxHashMap<DefId, clean::TraitWithExtraInfo>>>,
+    /// Traits defined outside the current crate.
+    ///
+    /// Later on moved into `cache`.
+    crate external_traits: FxHashMap<DefId, clean::TraitWithExtraInfo>,
     /// Used while populating `external_traits` to ensure we don't process the same trait twice at
     /// the same time.
     crate active_extern_traits: FxHashSet<DefId>,
@@ -375,7 +377,6 @@ crate fn run_global_ctxt(
         let mut sized_trait = build_external_trait(&mut ctxt, sized_trait_did);
         sized_trait.is_auto = true;
         ctxt.external_traits
-            .borrow_mut()
             .insert(sized_trait_did, TraitWithExtraInfo { trait_: sized_trait, is_notable: false });
     }
 
@@ -494,7 +495,8 @@ crate fn run_global_ctxt(
 
     let render_options = ctxt.render_options;
     let mut cache = ctxt.cache;
-    krate = tcx.sess.time("create_format_cache", || cache.populate(krate, tcx, &render_options));
+    cache.traits = ctxt.external_traits;
+    krate = tcx.sess.time("create_format_cache", || cache.populate(tcx, krate, &render_options));
 
     // The main crate doc comments are always collapsed.
     krate.collapsed = true;

src/librustdoc/fold.rs

@@ -85,15 +85,6 @@ crate trait DocFolder: Sized {
 
     fn fold_crate(&mut self, mut c: Crate) -> Crate {
         c.module = self.fold_item(c.module).unwrap();
-
-        {
-            let external_traits = { std::mem::take(&mut *c.external_traits.borrow_mut()) };
-            for (k, mut v) in external_traits {
-                v.trait_.items =
-                    v.trait_.items.into_iter().filter_map(|i| self.fold_item(i)).collect();
-                c.external_traits.borrow_mut().insert(k, v);
-            }
-        }
         c
     }
 }

src/librustdoc/formats/cache.rs

@@ -138,13 +138,12 @@ impl Cache {
     /// in `krate` due to the data being moved into the `Cache`.
     crate fn populate(
         &mut self,
-        mut krate: clean::Crate,
         tcx: TyCtxt<'_>,
+        mut krate: clean::Crate,
         render_options: &RenderOptions,
     ) -> clean::Crate {
         // Crawl the crate to build various caches used for the output
         debug!(?self.crate_version);
-        self.traits = krate.external_traits.take();
         let RenderOptions { extern_html_root_takes_precedence, output: dst, .. } = render_options;
 
         // Cache where all our extern crates are located