Minimize amount of fake DefIds used in rustdoc

src/librustdoc/html/render/cache.rs

@@ -7,7 +7,7 @@ use serde::ser::{Serialize, SerializeStruct, Serializer};
 
 use crate::clean;
 use crate::clean::types::{
-    FakeDefId, FnDecl, FnRetTy, GenericBound, Generics, GetDefId, Type, WherePredicate,
+    FnDecl, FnRetTy, GenericBound, Generics, GetDefId, Type, WherePredicate,
 };
 use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
@@ -82,7 +82,7 @@ crate fn build_index<'tcx>(krate: &clean::Crate, cache: &mut Cache, tcx: TyCtxt<
                 defid_to_pathid.insert(defid, pathid);
                 lastpathid += 1;
 
-                if let Some(&(ref fqp, short)) = paths.get(&defid.expect_real()) {
+                if let Some(&(ref fqp, short)) = paths.get(&defid) {
                     crate_paths.push((short, fqp.last().unwrap().clone()));
                     Some(pathid)
                 } else {
@@ -214,7 +214,7 @@ crate fn get_index_search_type<'tcx>(
 
 fn get_index_type(clean_type: &clean::Type, cache: &Cache) -> RenderType {
     RenderType {
-        ty: clean_type.def_id_full(cache).map(FakeDefId::new_real),
+        ty: clean_type.def_id_full(cache),
         idx: None,
         name: get_index_type_name(clean_type, true).map(|s| s.as_str().to_ascii_lowercase()),
         generics: get_generics(clean_type, cache),
@@ -256,7 +256,7 @@ fn get_generics(clean_type: &clean::Type, cache: &Cache) -> Option<Vec<Generic>>
             .filter_map(|t| {
                 get_index_type_name(t, false).map(|name| Generic {
                     name: name.as_str().to_ascii_lowercase(),
-                    defid: t.def_id_full(cache).map(FakeDefId::new_real),
+                    defid: t.def_id_full(cache),
                     idx: None,
                 })
             })

src/librustdoc/html/render/mod.rs

@@ -87,7 +87,7 @@ crate struct IndexItem {
     crate name: String,
     crate path: String,
     crate desc: String,
-    crate parent: Option<FakeDefId>,
+    crate parent: Option<DefId>,
     crate parent_idx: Option<usize>,
     crate search_type: Option<IndexItemFunctionType>,
     crate aliases: Box<[String]>,
@@ -96,7 +96,7 @@ crate struct IndexItem {
 /// A type used for the search index.
 #[derive(Debug)]
 crate struct RenderType {
-    ty: Option<FakeDefId>,
+    ty: Option<DefId>,
     idx: Option<usize>,
     name: Option<String>,
     generics: Option<Vec<Generic>>,
@@ -128,7 +128,7 @@ impl Serialize for RenderType {
 #[derive(Debug)]
 crate struct Generic {
     name: String,
-    defid: Option<FakeDefId>,
+    defid: Option<DefId>,
     idx: Option<usize>,
 }
 
@@ -2137,7 +2137,7 @@ fn sidebar_trait(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, t: &clean
         "</div>",
     );
 
-    if let Some(implementors) = cx.cache.implementors.get(&it.def_id) {
+    if let Some(implementors) = cx.cache.implementors.get(&it.def_id.expect_real()) {
         let cache = cx.cache();
         let mut res = implementors
             .iter()

src/librustdoc/html/render/print_item.rs

@@ -642,7 +642,7 @@ fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Tra
     // If there are methods directly on this trait object, render them here.
     render_assoc_items(w, cx, it, it.def_id.expect_real(), AssocItemRender::All);
 
-    if let Some(implementors) = cx.cache.implementors.get(&it.def_id) {
+    if let Some(implementors) = cx.cache.implementors.get(&it.def_id.expect_real()) {
         // The DefId is for the first Type found with that name. The bool is
         // if any Types with the same name but different DefId have been found.
         let mut implementor_dups: FxHashMap<Symbol, (DefId, bool)> = FxHashMap::default();

src/librustdoc/html/render/write_shared.rs

@@ -465,8 +465,6 @@ pub(super) fn write_shared(
     // Update the list of all implementors for traits
     let dst = cx.dst.join("implementors");
     for (&did, imps) in &cx.cache.implementors {
-        let did = did.expect_real();
-
         // Private modules can leak through to this phase of rustdoc, which
         // could contain implementations for otherwise private types. In some
         // rare cases we could find an implementation for an item which wasn't