Auto merge of #80987 - GuillaumeGomez:remove-cache-key, r=jyn514

Remove CACHE_KEY global

We realized in https://github.com/rust-lang/rust/pull/80914 that the cache handling (through a global) needed to be updated to make it much easier to handle.

r? `@jyn514`

src/librustdoc/clean/mod.rs

@@ -2329,14 +2329,14 @@ impl Clean<Item> for (&hir::MacroDef<'_>, Option<Symbol>) {
             if matchers.len() <= 1 {
                 format!(
                     "{}macro {}{} {{\n    ...\n}}",
-                    vis.print_with_space(cx.tcx, def_id),
+                    vis.print_with_space(cx.tcx, def_id, &cx.cache),
                     name,
                     matchers.iter().map(|span| span.to_src(cx)).collect::<String>(),
                 )
             } else {
                 format!(
                     "{}macro {} {{\n{}}}",
-                    vis.print_with_space(cx.tcx, def_id),
+                    vis.print_with_space(cx.tcx, def_id, &cx.cache),
                     name,
                     matchers
                         .iter()

src/librustdoc/clean/types.rs

@@ -37,7 +37,7 @@ use crate::clean::inline;
 use crate::clean::types::Type::{QPath, ResolvedPath};
 use crate::clean::Clean;
 use crate::core::DocContext;
-use crate::formats::cache::cache;
+use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
 use crate::html::render::cache::ExternalLocation;
 
@@ -169,8 +169,8 @@ impl Item {
         self.attrs.collapsed_doc_value()
     }
 
-    crate fn links(&self) -> Vec<RenderedLink> {
+    crate fn links(&self, cache: &Cache) -> Vec<RenderedLink> {
-        self.attrs.links(&self.def_id.krate)
+        self.attrs.links(&self.def_id.krate, cache)
     }
 
     crate fn is_crate(&self) -> bool {
@@ -826,7 +826,7 @@ impl Attributes {
     /// Gets links as a vector
     ///
     /// Cache must be populated before call
-    crate fn links(&self, krate: &CrateNum) -> Vec<RenderedLink> {
+    crate fn links(&self, krate: &CrateNum, cache: &Cache) -> Vec<RenderedLink> {
         use crate::html::format::href;
         use crate::html::render::CURRENT_DEPTH;
 
@@ -835,7 +835,7 @@ impl Attributes {
             .filter_map(|ItemLink { link: s, link_text, did, fragment }| {
                 match *did {
                     Some(did) => {
-                        if let Some((mut href, ..)) = href(did) {
+                        if let Some((mut href, ..)) = href(did, cache) {
                             if let Some(ref fragment) = *fragment {
                                 href.push('#');
                                 href.push_str(fragment);
@@ -851,7 +851,6 @@ impl Attributes {
                     }
                     None => {
                         if let Some(ref fragment) = *fragment {
-                            let cache = cache();
                             let url = match cache.extern_locations.get(krate) {
                                 Some(&(_, _, ExternalLocation::Local)) => {
                                     let depth = CURRENT_DEPTH.with(|l| l.get());
@@ -1177,6 +1176,13 @@ impl GetDefId for FnRetTy {
             DefaultReturn => None,
         }
     }
+
+    fn def_id_full(&self, cache: &Cache) -> Option<DefId> {
+        match *self {
+            Return(ref ty) => ty.def_id_full(cache),
+            DefaultReturn => None,
+        }
+    }
 }
 
 #[derive(Clone, Debug)]
@@ -1299,13 +1305,31 @@ crate enum TypeKind {
 }
 
 crate trait GetDefId {
+    /// Use this method to get the [`DefId`] of a [`clean`] AST node.
+    /// This will return [`None`] when called on a primitive [`clean::Type`].
+    /// Use [`Self::def_id_full`] if you want to include primitives.
+    ///
+    /// [`clean`]: crate::clean
+    /// [`clean::Type`]: crate::clean::Type
+    // FIXME: get rid of this function and always use `def_id_full`
     fn def_id(&self) -> Option<DefId>;
+
+    /// Use this method to get the [DefId] of a [clean] AST node, including [PrimitiveType]s.
+    ///
+    /// See [`Self::def_id`] for more.
+    ///
+    /// [clean]: crate::clean
+    fn def_id_full(&self, cache: &Cache) -> Option<DefId>;
 }
 
 impl<T: GetDefId> GetDefId for Option<T> {
     fn def_id(&self) -> Option<DefId> {
         self.as_ref().and_then(|d| d.def_id())
     }
+
+    fn def_id_full(&self, cache: &Cache) -> Option<DefId> {
+        self.as_ref().and_then(|d| d.def_id_full(cache))
+    }
 }
 
 impl Type {
@@ -1393,30 +1417,40 @@ impl Type {
     }
 }
 
-impl GetDefId for Type {
+impl Type {
-    fn def_id(&self) -> Option<DefId> {
+    fn inner_def_id(&self, cache: Option<&Cache>) -> Option<DefId> {
-        match *self {
+        let t: PrimitiveType = match *self {
-            ResolvedPath { did, .. } => Some(did),
+            ResolvedPath { did, .. } => return Some(did),
-            Primitive(p) => cache().primitive_locations.get(&p).cloned(),
+            Primitive(p) => return cache.and_then(|c| c.primitive_locations.get(&p).cloned()),
-            BorrowedRef { type_: box Generic(..), .. } => {
+            BorrowedRef { type_: box Generic(..), .. } => PrimitiveType::Reference,
-                Primitive(PrimitiveType::Reference).def_id()
+            BorrowedRef { ref type_, .. } => return type_.inner_def_id(cache),
-            }
-            BorrowedRef { ref type_, .. } => type_.def_id(),
             Tuple(ref tys) => {
                 if tys.is_empty() {
-                    Primitive(PrimitiveType::Unit).def_id()
+                    PrimitiveType::Unit
                 } else {
-                    Primitive(PrimitiveType::Tuple).def_id()
+                    PrimitiveType::Tuple
                 }
             }
-            BareFunction(..) => Primitive(PrimitiveType::Fn).def_id(),
+            BareFunction(..) => PrimitiveType::Fn,
-            Never => Primitive(PrimitiveType::Never).def_id(),
+            Never => PrimitiveType::Never,
-            Slice(..) => Primitive(PrimitiveType::Slice).def_id(),
+            Slice(..) => PrimitiveType::Slice,
-            Array(..) => Primitive(PrimitiveType::Array).def_id(),
+            Array(..) => PrimitiveType::Array,
-            RawPointer(..) => Primitive(PrimitiveType::RawPointer).def_id(),
+            RawPointer(..) => PrimitiveType::RawPointer,
-            QPath { ref self_type, .. } => self_type.def_id(),
+            QPath { ref self_type, .. } => return self_type.inner_def_id(cache),
-            _ => None,
+            // FIXME: remove this wildcard
-        }
+            _ => return None,
+        };
+        cache.and_then(|c| Primitive(t).def_id_full(c))
+    }
+}
+
+impl GetDefId for Type {
+    fn def_id(&self) -> Option<DefId> {
+        self.inner_def_id(None)
+    }
+
+    fn def_id_full(&self, cache: &Cache) -> Option<DefId> {
+        self.inner_def_id(Some(cache))
     }
 }
 
@@ -1817,6 +1851,10 @@ impl GetDefId for Typedef {
     fn def_id(&self) -> Option<DefId> {
         self.type_.def_id()
     }
+
+    fn def_id_full(&self, cache: &Cache) -> Option<DefId> {
+        self.type_.def_id_full(cache)
+    }
 }
 
 #[derive(Clone, Debug)]

src/librustdoc/clean/utils.rs

@@ -177,7 +177,7 @@ crate fn get_real_types(
         return res;
     }
     if arg.is_full_generic() {
-        let arg_s = Symbol::intern(&arg.print().to_string());
+        let arg_s = Symbol::intern(&arg.print(&cx.cache).to_string());
         if let Some(where_pred) = generics.where_predicates.iter().find(|g| match g {
             WherePredicate::BoundPredicate { ty, .. } => ty.def_id() == arg.def_id(),
             _ => false,
@@ -473,7 +473,7 @@ crate fn resolve_type(cx: &DocContext<'_>, path: Path, id: hir::HirId) -> Type {
             return Generic(kw::SelfUpper);
         }
         Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => {
-            return Generic(Symbol::intern(&format!("{:#}", path.print())));
+            return Generic(Symbol::intern(&format!("{:#}", path.print(&cx.cache))));
         }
         Res::SelfTy(..) | Res::Def(DefKind::TyParam | DefKind::AssocTy, _) => true,
         _ => false,

src/librustdoc/config.rs

@@ -261,7 +261,7 @@ crate struct RenderOptions {
 }
 
 /// Temporary storage for data obtained during `RustdocVisitor::clean()`.
-/// Later on moved into `CACHE_KEY`.
+/// Later on moved into `cache`.
 #[derive(Default, Clone)]
 crate struct RenderInfo {
     crate inlined: FxHashSet<DefId>,

src/librustdoc/core.rs

@@ -32,6 +32,7 @@ use crate::clean;
 use crate::clean::{AttributesExt, MAX_DEF_ID};
 use crate::config::{Options as RustdocOptions, RenderOptions};
 use crate::config::{OutputFormat, RenderInfo};
+use crate::formats::cache::Cache;
 use crate::passes::{self, Condition::*, ConditionalPass};
 
 crate use rustc_session::config::{DebuggingOptions, Input, Options};
@@ -45,9 +46,9 @@ crate struct DocContext<'tcx> {
     ///
     /// Most of this logic is copied from rustc_lint::late.
     crate param_env: Cell<ParamEnv<'tcx>>,
-    /// Later on moved into `CACHE_KEY`
+    /// Later on moved into `cache`
     crate renderinfo: RefCell<RenderInfo>,
-    /// Later on moved through `clean::Crate` into `CACHE_KEY`
+    /// Later on moved through `clean::Crate` into `cache`
     crate external_traits: Rc<RefCell<FxHashMap<DefId, clean::Trait>>>,
     /// Used while populating `external_traits` to ensure we don't process the same trait twice at
     /// the same time.
@@ -75,6 +76,8 @@ crate struct DocContext<'tcx> {
     /// See `collect_intra_doc_links::traits_implemented_by` for more details.
     /// `map<module, set<trait>>`
     crate module_trait_cache: RefCell<FxHashMap<DefId, FxHashSet<DefId>>>,
+    /// Fake empty cache used when cache is required as parameter.
+    crate cache: Cache,
 }
 
 impl<'tcx> DocContext<'tcx> {
@@ -524,6 +527,7 @@ crate fn run_global_ctxt(
             .collect(),
         render_options,
         module_trait_cache: RefCell::new(FxHashMap::default()),
+        cache: Cache::default(),
     };
     debug!("crate: {:?}", tcx.hir().krate());
 

src/librustdoc/formats/cache.rs

@@ -1,8 +1,6 @@
-use std::cell::RefCell;
 use std::collections::BTreeMap;
 use std::mem;
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX};
@@ -19,8 +17,6 @@ use crate::html::markdown::short_markdown_summary;
 use crate::html::render::cache::{extern_location, get_index_search_type, ExternalLocation};
 use crate::html::render::IndexItem;
 
-thread_local!(crate static CACHE_KEY: RefCell<Arc<Cache>> = Default::default());
-
 /// This cache is used to store information about the [`clean::Crate`] being
 /// rendered in order to provide more useful documentation. This contains
 /// information like all implementors of a trait, all traits a type implements,
@@ -197,6 +193,7 @@ impl Cache {
         }
 
         cache.stack.push(krate.name.to_string());
+
         krate = cache.fold_crate(krate);
 
         for (trait_did, dids, impl_) in cache.orphan_trait_impls.drain(..) {
@@ -319,7 +316,7 @@ impl DocFolder for Cache {
                                 .map_or_else(String::new, |x| short_markdown_summary(&x.as_str())),
                             parent,
                             parent_idx: None,
-                            search_type: get_index_search_type(&item),
+                            search_type: get_index_search_type(&item, None),
                         });
 
                         for alias in item.attrs.get_doc_aliases() {
@@ -477,7 +474,3 @@ impl DocFolder for Cache {
         ret
     }
 }
-
-crate fn cache() -> Arc<Cache> {
-    CACHE_KEY.with(|c| c.borrow().clone())
-}

src/librustdoc/formats/mod.rs

@@ -8,6 +8,7 @@ use rustc_span::def_id::DefId;
 
 use crate::clean;
 use crate::clean::types::GetDefId;
+use crate::formats::cache::Cache;
 
 /// Specifies whether rendering directly implemented trait items or ones from a certain Deref
 /// impl.
@@ -41,4 +42,8 @@ impl Impl {
     crate fn trait_did(&self) -> Option<DefId> {
         self.inner_impl().trait_.def_id()
     }
+
+    crate fn trait_did_full(&self, cache: &Cache) -> Option<DefId> {
+        self.inner_impl().trait_.def_id_full(cache)
+    }
 }

src/librustdoc/formats/renderer.rs

@@ -1,12 +1,10 @@
-use std::sync::Arc;
-
 use rustc_middle::ty::TyCtxt;
 use rustc_span::edition::Edition;
 
 use crate::clean;
 use crate::config::{RenderInfo, RenderOptions};
 use crate::error::Error;
-use crate::formats::cache::{Cache, CACHE_KEY};
+use crate::formats::cache::Cache;
 
 /// Allows for different backends to rustdoc to be used with the `run_format()` function. Each
 /// backend renderer has hooks for initialization, documenting an item, entering and exiting a
@@ -22,20 +20,15 @@ crate trait FormatRenderer<'tcx>: Clone {
         options: RenderOptions,
         render_info: RenderInfo,
         edition: Edition,
-        cache: &mut Cache,
+        cache: Cache,
         tcx: TyCtxt<'tcx>,
     ) -> Result<(Self, clean::Crate), Error>;
 
     /// Renders a single non-module item. This means no recursive sub-item rendering is required.
-    fn item(&mut self, item: clean::Item, cache: &Cache) -> Result<(), Error>;
+    fn item(&mut self, item: clean::Item) -> Result<(), Error>;
 
     /// Renders a module (should not handle recursing into children).
-    fn mod_item_in(
+    fn mod_item_in(&mut self, item: &clean::Item, item_name: &str) -> Result<(), Error>;
-        &mut self,
-        item: &clean::Item,
-        item_name: &str,
-        cache: &Cache,
-    ) -> Result<(), Error>;
 
     /// Runs after recursively rendering all sub-items of a module.
     fn mod_item_out(&mut self, item_name: &str) -> Result<(), Error>;
@@ -46,9 +39,10 @@ crate trait FormatRenderer<'tcx>: Clone {
     fn after_krate(
         &mut self,
         krate: &clean::Crate,
-        cache: &Cache,
         diag: &rustc_errors::Handler,
     ) -> Result<(), Error>;
+
+    fn cache(&self) -> &Cache;
 }
 
 /// Main method for rendering a crate.
@@ -60,7 +54,7 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
     edition: Edition,
     tcx: TyCtxt<'tcx>,
 ) -> Result<(), Error> {
-    let (krate, mut cache) = tcx.sess.time("create_format_cache", || {
+    let (krate, cache) = tcx.sess.time("create_format_cache", || {
         Cache::from_krate(
             render_info.clone(),
             options.document_private,
@@ -73,12 +67,7 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
 
     let (mut format_renderer, mut krate) = prof
         .extra_verbose_generic_activity("create_renderer", T::descr())
-        .run(|| T::init(krate, options, render_info, edition, &mut cache, tcx))?;
+        .run(|| T::init(krate, options, render_info, edition, cache, tcx))?;
-
-    let cache = Arc::new(cache);
-    // Freeze the cache now that the index has been built. Put an Arc into TLS for future
-    // parallelization opportunities
-    CACHE_KEY.with(|v| *v.borrow_mut() = cache.clone());
 
     let mut item = match krate.module.take() {
         Some(i) => i,
@@ -101,7 +90,7 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
             }
             let _timer = prof.generic_activity_with_arg("render_mod_item", name.as_str());
 
-            cx.mod_item_in(&item, &name, &cache)?;
+            cx.mod_item_in(&item, &name)?;
             let module = match *item.kind {
                 clean::StrippedItem(box clean::ModuleItem(m)) | clean::ModuleItem(m) => m,
                 _ => unreachable!(),
@@ -114,9 +103,9 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
             cx.mod_item_out(&name)?;
         } else if item.name.is_some() {
             prof.generic_activity_with_arg("render_item", &*item.name.unwrap_or(unknown).as_str())
-                .run(|| cx.item(item, &cache))?;
+                .run(|| cx.item(item))?;
         }
     }
     prof.extra_verbose_generic_activity("renderer_after_krate", T::descr())
-        .run(|| format_renderer.after_krate(&krate, &cache, diag))
+        .run(|| format_renderer.after_krate(&krate, diag))
 }

src/librustdoc/html/render/cache.rs

@@ -67,31 +67,31 @@ crate fn build_index(krate: &clean::Crate, cache: &mut Cache) -> String {
     let mut crate_items = Vec::with_capacity(cache.search_index.len());
     let mut crate_paths = vec![];
 
-    let Cache { ref mut search_index, ref orphan_impl_items, ref paths, ref mut aliases, .. } =
-        *cache;
-
     // Attach all orphan items to the type's definition if the type
     // has since been learned.
-    for &(did, ref item) in orphan_impl_items {
+    for &(did, ref item) in &cache.orphan_impl_items {
-        if let Some(&(ref fqp, _)) = paths.get(&did) {
+        if let Some(&(ref fqp, _)) = cache.paths.get(&did) {
-            search_index.push(IndexItem {
+            cache.search_index.push(IndexItem {
                 ty: item.type_(),
                 name: item.name.unwrap().to_string(),
                 path: fqp[..fqp.len() - 1].join("::"),
                 desc: item.doc_value().map_or_else(String::new, |s| short_markdown_summary(&s)),
                 parent: Some(did),
                 parent_idx: None,
-                search_type: get_index_search_type(&item),
+                search_type: get_index_search_type(&item, None),
             });
             for alias in item.attrs.get_doc_aliases() {
-                aliases
+                cache
+                    .aliases
                     .entry(alias.to_lowercase())
                     .or_insert(Vec::new())
-                    .push(search_index.len() - 1);
+                    .push(cache.search_index.len() - 1);
             }
         }
     }
 
+    let Cache { ref mut search_index, ref paths, ref mut aliases, .. } = *cache;
+
     // Reduce `DefId` in paths into smaller sequential numbers,
     // and prune the paths that do not appear in the index.
     let mut lastpath = String::new();
@@ -164,7 +164,10 @@ crate fn build_index(krate: &clean::Crate, cache: &mut Cache) -> String {
     )
 }
 
-crate fn get_index_search_type(item: &clean::Item) -> Option<IndexItemFunctionType> {
+crate fn get_index_search_type(
+    item: &clean::Item,
+    cache: Option<&Cache>,
+) -> Option<IndexItemFunctionType> {
     let (all_types, ret_types) = match *item.kind {
         clean::FunctionItem(ref f) => (&f.all_types, &f.ret_types),
         clean::MethodItem(ref m, _) => (&m.all_types, &m.ret_types),
@@ -174,12 +177,12 @@ crate fn get_index_search_type(item: &clean::Item) -> Option<IndexItemFunctionTy
 
     let inputs = all_types
         .iter()
-        .map(|(ty, kind)| TypeWithKind::from((get_index_type(&ty), *kind)))
+        .map(|(ty, kind)| TypeWithKind::from((get_index_type(&ty, &cache), *kind)))
         .filter(|a| a.ty.name.is_some())
         .collect();
     let output = ret_types
         .iter()
-        .map(|(ty, kind)| TypeWithKind::from((get_index_type(&ty), *kind)))
+        .map(|(ty, kind)| TypeWithKind::from((get_index_type(&ty, &cache), *kind)))
         .filter(|a| a.ty.name.is_some())
         .collect::<Vec<_>>();
     let output = if output.is_empty() { None } else { Some(output) };
@@ -187,12 +190,12 @@ crate fn get_index_search_type(item: &clean::Item) -> Option<IndexItemFunctionTy
     Some(IndexItemFunctionType { inputs, output })
 }
 
-fn get_index_type(clean_type: &clean::Type) -> RenderType {
+fn get_index_type(clean_type: &clean::Type, cache: &Option<&Cache>) -> RenderType {
     RenderType {
-        ty: clean_type.def_id(),
+        ty: cache.map_or_else(|| clean_type.def_id(), |cache| 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),
+        generics: get_generics(clean_type, cache),
     }
 }
 
@@ -216,14 +219,14 @@ fn get_index_type_name(clean_type: &clean::Type, accept_generic: bool) -> Option
     }
 }
 
-fn get_generics(clean_type: &clean::Type) -> Option<Vec<Generic>> {
+fn get_generics(clean_type: &clean::Type, cache: &Option<&Cache>) -> Option<Vec<Generic>> {
     clean_type.generics().and_then(|types| {
         let r = types
             .iter()
             .filter_map(|t| {
                 get_index_type_name(t, false).map(|name| Generic {
                     name: name.as_str().to_ascii_lowercase(),
-                    defid: t.def_id(),
+                    defid: cache.map_or_else(|| t.def_id(), |cache| t.def_id_full(cache)),
                     idx: None,
                 })
             })

src/librustdoc/json/mod.rs

@@ -32,6 +32,7 @@ crate struct JsonRenderer<'tcx> {
     index: Rc<RefCell<FxHashMap<types::Id, types::Item>>>,
     /// The directory where the blob will be written to.
     out_path: PathBuf,
+    cache: Rc<Cache>,
 }
 
 impl JsonRenderer<'_> {
@@ -39,12 +40,8 @@ impl JsonRenderer<'_> {
         self.tcx.sess
     }
 
-    fn get_trait_implementors(
+    fn get_trait_implementors(&mut self, id: rustc_span::def_id::DefId) -> Vec<types::Id> {
-        &mut self,
+        Rc::clone(&self.cache)
-        id: rustc_span::def_id::DefId,
-        cache: &Cache,
-    ) -> Vec<types::Id> {
-        cache
             .implementors
             .get(&id)
             .map(|implementors| {
@@ -52,7 +49,7 @@ impl JsonRenderer<'_> {
                     .iter()
                     .map(|i| {
                         let item = &i.impl_item;
-                        self.item(item.clone(), cache).unwrap();
+                        self.item(item.clone()).unwrap();
                         item.def_id.into()
                     })
                     .collect()
@@ -60,8 +57,8 @@ impl JsonRenderer<'_> {
             .unwrap_or_default()
     }
 
-    fn get_impls(&mut self, id: rustc_span::def_id::DefId, cache: &Cache) -> Vec<types::Id> {
+    fn get_impls(&mut self, id: rustc_span::def_id::DefId) -> Vec<types::Id> {
-        cache
+        Rc::clone(&self.cache)
             .impls
             .get(&id)
             .map(|impls| {
@@ -70,7 +67,7 @@ impl JsonRenderer<'_> {
                     .filter_map(|i| {
                         let item = &i.impl_item;
                         if item.def_id.is_local() {
-                            self.item(item.clone(), cache).unwrap();
+                            self.item(item.clone()).unwrap();
                             Some(item.def_id.into())
                         } else {
                             None
@@ -81,24 +78,25 @@ impl JsonRenderer<'_> {
             .unwrap_or_default()
     }
 
-    fn get_trait_items(&mut self, cache: &Cache) -> Vec<(types::Id, types::Item)> {
+    fn get_trait_items(&mut self) -> Vec<(types::Id, types::Item)> {
-        cache
+        Rc::clone(&self.cache)
             .traits
             .iter()
             .filter_map(|(&id, trait_item)| {
                 // only need to synthesize items for external traits
                 if !id.is_local() {
-                    trait_item.items.clone().into_iter().for_each(|i| self.item(i, cache).unwrap());
+                    trait_item.items.clone().into_iter().for_each(|i| self.item(i).unwrap());
                     Some((
                         id.into(),
                         types::Item {
                             id: id.into(),
                             crate_id: id.krate.as_u32(),
-                            name: cache
+                            name: self
+                                .cache
                                 .paths
                                 .get(&id)
                                 .unwrap_or_else(|| {
-                                    cache
+                                    self.cache
                                         .external_paths
                                         .get(&id)
                                         .expect("Trait should either be in local or external paths")
@@ -134,7 +132,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         options: RenderOptions,
         _render_info: RenderInfo,
         _edition: Edition,
-        _cache: &mut Cache,
+        cache: Cache,
         tcx: TyCtxt<'tcx>,
     ) -> Result<(Self, clean::Crate), Error> {
         debug!("Initializing json renderer");
@@ -143,6 +141,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
                 tcx,
                 index: Rc::new(RefCell::new(FxHashMap::default())),
                 out_path: options.output,
+                cache: Rc::new(cache),
             },
             krate,
         ))
@@ -151,18 +150,18 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
     /// Inserts an item into the index. This should be used rather than directly calling insert on
     /// the hashmap because certain items (traits and types) need to have their mappings for trait
     /// implementations filled out before they're inserted.
-    fn item(&mut self, item: clean::Item, cache: &Cache) -> Result<(), Error> {
+    fn item(&mut self, item: clean::Item) -> Result<(), Error> {
         // Flatten items that recursively store other items
-        item.kind.inner_items().for_each(|i| self.item(i.clone(), cache).unwrap());
+        item.kind.inner_items().for_each(|i| self.item(i.clone()).unwrap());
 
         let id = item.def_id;
         if let Some(mut new_item) = self.convert_item(item) {
             if let types::ItemEnum::TraitItem(ref mut t) = new_item.inner {
-                t.implementors = self.get_trait_implementors(id, cache)
+                t.implementors = self.get_trait_implementors(id)
             } else if let types::ItemEnum::StructItem(ref mut s) = new_item.inner {
-                s.impls = self.get_impls(id, cache)
+                s.impls = self.get_impls(id)
             } else if let types::ItemEnum::EnumItem(ref mut e) = new_item.inner {
-                e.impls = self.get_impls(id, cache)
+                e.impls = self.get_impls(id)
             }
             let removed = self.index.borrow_mut().insert(id.into(), new_item.clone());
             // FIXME(adotinthevoid): Currently, the index is duplicated. This is a sanity check
@@ -175,27 +174,20 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         Ok(())
     }
 
-    fn mod_item_in(
+    fn mod_item_in(&mut self, item: &clean::Item, _module_name: &str) -> Result<(), Error> {
-        &mut self,
-        item: &clean::Item,
-        _module_name: &str,
-        cache: &Cache,
-    ) -> Result<(), Error> {
         use clean::types::ItemKind::*;
         if let ModuleItem(m) = &*item.kind {
             for item in &m.items {
                 match &*item.kind {
                     // These don't have names so they don't get added to the output by default
-                    ImportItem(_) => self.item(item.clone(), cache).unwrap(),
+                    ImportItem(_) => self.item(item.clone()).unwrap(),
-                    ExternCrateItem(_, _) => self.item(item.clone(), cache).unwrap(),
+                    ExternCrateItem(_, _) => self.item(item.clone()).unwrap(),
-                    ImplItem(i) => {
+                    ImplItem(i) => i.items.iter().for_each(|i| self.item(i.clone()).unwrap()),
-                        i.items.iter().for_each(|i| self.item(i.clone(), cache).unwrap())
-                    }
                     _ => {}
                 }
             }
         }
-        self.item(item.clone(), cache).unwrap();
+        self.item(item.clone()).unwrap();
         Ok(())
     }
 
@@ -206,22 +198,22 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
     fn after_krate(
         &mut self,
         krate: &clean::Crate,
-        cache: &Cache,
         _diag: &rustc_errors::Handler,
     ) -> Result<(), Error> {
         debug!("Done with crate");
         let mut index = (*self.index).clone().into_inner();
-        index.extend(self.get_trait_items(cache));
+        index.extend(self.get_trait_items());
         let output = types::Crate {
             root: types::Id(String::from("0:0")),
             crate_version: krate.version.clone(),
-            includes_private: cache.document_private,
+            includes_private: self.cache.document_private,
             index,
-            paths: cache
+            paths: self
+                .cache
                 .paths
                 .clone()
                 .into_iter()
-                .chain(cache.external_paths.clone().into_iter())
+                .chain(self.cache.external_paths.clone().into_iter())
                 .map(|(k, (path, kind))| {
                     (
                         k.into(),
@@ -229,7 +221,8 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
                     )
                 })
                 .collect(),
-            external_crates: cache
+            external_crates: self
+                .cache
                 .extern_locations
                 .iter()
                 .map(|(k, v)| {
@@ -254,4 +247,8 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         serde_json::ser::to_writer(&file, &output).unwrap();
         Ok(())
     }
+
+    fn cache(&self) -> &Cache {
+        &self.cache
+    }
 }

src/librustdoc/passes/calculate_doc_coverage.rs

@@ -218,7 +218,12 @@ impl<'a, 'b> fold::DocFolder for CoverageCalculator<'a, 'b> {
             clean::ImplItem(ref impl_) => {
                 let filename = i.source.filename(self.ctx.sess());
                 if let Some(ref tr) = impl_.trait_ {
-                    debug!("impl {:#} for {:#} in {}", tr.print(), impl_.for_.print(), filename,);
+                    debug!(
+                        "impl {:#} for {:#} in {}",
+                        tr.print(&self.ctx.cache),
+                        impl_.for_.print(&self.ctx.cache),
+                        filename,
+                    );
 
                     // don't count trait impls, the missing-docs lint doesn't so we shouldn't
                     // either
@@ -227,7 +232,7 @@ impl<'a, 'b> fold::DocFolder for CoverageCalculator<'a, 'b> {
                     // inherent impls *can* be documented, and those docs show up, but in most
                     // cases it doesn't make sense, as all methods on a type are in one single
                     // impl block
-                    debug!("impl {:#} in {}", impl_.for_.print(), filename);
+                    debug!("impl {:#} in {}", impl_.for_.print(&self.ctx.cache), filename);
                 }
             }
             _ => {

src/test/rustdoc-js-std/primitive.js

@@ -0,0 +1,75 @@
+const QUERY = [
+    'i8',
+    'u32',
+    'str',
+    'char',
+    'unit',
+    'tuple',
+    'fn',
+];
+
+const EXPECTED = [
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'i8',
+                'href': '../std/primitive.i8.html',
+            },
+        ]
+    },
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'u32',
+                'href': '../std/primitive.u32.html',
+            },
+        ]
+    },
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'str',
+                'href': '../std/primitive.str.html',
+            },
+        ]
+    },
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'char',
+                'href': '../std/primitive.char.html',
+            },
+        ]
+    },
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'unit',
+                'href': '../std/primitive.unit.html',
+            },
+        ]
+    },
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'tuple',
+                'href': '../std/primitive.tuple.html',
+            },
+        ]
+    },
+    {
+        'others': [
+            {
+                'path': 'std',
+                'name': 'fn',
+                'href': '../std/primitive.fn.html',
+            },
+        ]
+    },
+];